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The effect of tetraethylthiuramdisulfide (disulfiram) on the catabolism of dopamine within discrete regions of the brain was investigated in the unrestrained rat. After a guide cannula had been implanted stereotaxically, a given subcortical site was radiolabeled with 14C-dopamine (DA) by microinjecting 2.0 mu Ci in 2.0 microliters. Successive push-pull perfusates collected from each tissue were assayed by paper electrophoresis for the separation of DA metabolites. When disulfiram, a potent aldehyde dehydrogenase (ALDH) inhibitor, was given intragastrically in a clinically efficacious dose of 200 mg, the formation of the acids DOPAC and HVA was inhibited within perfusates of the caudate nucleus and nucleus accumbens. However, following disulfiram treatment, the proportion of alcohol metabolites did not differ from the control level in the untreated rat. The level of ALDH decreased by approximately 50% in these subcortical nuclei following the inhibition of the enzyme by disulfiram. Conversely, in samples of perfusate obtained from 14C-labeled sites within inferofrontal cortex, periform cortex, diagonal band of Broca, lateral-posterior caudate nucleus, tuberculum olfactorium, lateral olfactory tract or the olfactory nuclear complex, the proportion of DA metabolites remained stable. Generally, a low rate of deamination of the exogenously injected DA occurred within perfusion sites in the ventrobasal forebrain, whereas an intermediate rate of deamination was noted in samples collected at more dorsal loci. Thus, clearcut regional differences in DA catabolism occur in the brain of the living animal, which may depend upon the characteristics of the dopaminergic-rich area of the rat's brain. | US |
Many similarities exist between the inhibitory influence of estrogen on food intake (FI) and body weight (BWt) in female rats and the effect of lateral hypothalamic (LH) lesions on energy balance. Thus, a possible interaction of small electrolytic LH lesions (0.8 mA/10 sec) with hormone-dependent changes in FI, BWt and feeding patterns of female rats was examined. Relative to sham operated controls, rats with LH lesions showed a transitory period of anorexia and initial loss of BWt. Subsequently, FI and BWt gains of lesioned rats returned to control levels although a small chronic reduction in mean BWt was observed relative to sham animals. Daily changes in FI and BWt during 4-day estrous cycles as well as post-ovariectomy increases in FI and BWt were comparable for lesion and sham animals. Also, both groups showed a similar decrease in FI and BWt following a SC injection of estradiol benzoate (EB). Possible effects of LH lesions were further examined by analyzing feeding patterns. Feeding behavior was continuously monitored with photodetectors and recorded on an Esterline Angus event marker before and after a single SC injection of 6 micrograms of EB. Relative to shams, LH animals showed an exaggerated diurnal distribution of meals, ate smaller meals of shorter duration and had larger intervals between meals during the light period. EB was found to shift the feeding patterns of sham animals towards the meal patterns shown by the lesioned rats (exaggerated diurnal distribution of meals, etc.). However, the lesioned rats also showed a normal change in feeding patterns following EB, albeit these changes occurred from a markedly different baseline level.(ABSTRACT TRUNCATED AT 250 WORDS) | US |
EEG was recorded from the dorsal hippocampus of cats during walking in situations intended to elicit a minimum of orienting or attentional behavior. The situations included walking in an alley for food after prolonged overtraining, and ad lib walking in an observation chamber after 24 hours habituation. In virtually all (82-100%) cases of sustained walking RSA was present in the dorsal hippocampus; however, the amplitude of the RSA during walking was quite variable and in many cases quite small. The results suggest that in the cat motoric factors may influence the occurrence of RSA and non-motoric factors may influence the amplitude of RSA. | US |
The postpericardiotomy syndrome is a febrile illness with pericardial and pleural reaction that either persists or appears beyond the 1st postoperative week. We believe that it begins in the 1st week after intrapericardial cardiac surgery, and that clinical signs of illness correlate with appearance of AHA and with significant rise in titer to AVA. Our present working hypothesis is that myocardial damage with bleeding into the pericardial sac at the time of surgery combines with concurrently acquired or reactivated viral illness to set the stage for the syndrome. The immune response is triggered by viral invasion of traumatized myocardium and an immune response is mounted, not against autologous myocardium per se but against the neo-antigen, the virus-infected myocardium. The illness is self-limited. It sometimes recurs but it seems to leave no sequelae other than the bad memory of a painful postoperative complication that prolonged hospitalization and delayed the realization of the full benefits of that heart operation. | US |
The present study examined the effects of lesions of the mammillary system on spatial memory and arousal. Destruction of the medial mammillary nucleus or the mammillotegmental tract produces impairments on a delayed alternation task and greatly increases activity in the open-field. Lesions of the mammillothalamic tract produce a differential effect in that the spatial alternation deficit is accompanied by a general lethargy and unresponsiveness. It is suggested that the mammillary system plays a crucial role in the short-term storage of proprioceptive information necessary for the successive execution of maze choices. It also appears to play a role in the arousal state of the animal. | US |
The effect of various pharmacologic agents on the noradrenergic innervation of rat cerebellum was observed. It was found that the neurotoxin 6-hydroxydopa (6-OHDOPA), when given to rats at birth, caused a 46% reduction at 5 weeks of age in tyrosine hydroxylase activity in the locus coeruleus, the nucleus of origin for noradrenergic fibers innervating the cerebellum. At the same time, however, both tyrosine hydroxylase activity and NE content were elevated by 50% in the cerebellum. By treating gravid mice with the 6-OHDOPA, which crosses the placental barrier to affect the brains of developing pups, a dissociation has been shown between the elevated cerebellar NE levels and reduced telencephalic NE content. None of the other assorted pharmacological agents--namely amphetamine, metaraminol, apomorphine, alpha-methyl-p-tyrosine. L-dihydroxyphenylalanine and tyramine--when given at birth, caused a permanent elevation in cerebellar NE content. This series of studies suggests that a reduced number of noradrenergic perikarya are providing a greater innervation of the cerebellum than in control rats. Also, alteration of the telencephalic noradrenergic fibers, which are also derived from the locus coeruleus, does not appear to be a necessary event for the initiation of sprouting of noradrenergic fibers in the cerebellum. Because none of the acute-acting pharmacological agents caused a permanent elevation of NE in the cerebellum, it appears that damage, and not mere stimulation or blockade, is a necessary event for initiation of sprouting. | US |
Inverted membrane vesicles from strain 7, a wild type Escherichia coli K12 strain, actively transport calcium with energy supplied either by respiration or by ATP. These vesicles also have energy-linked quenching of quinacrine fluorescence. Membranes of strain 7, depleted of Mg2+ATPase by EDTA treatment, lack both activities. Membrane vesicles from strain NR70, a mutant lacking the Mg2+ATPase, show neither calcium transport nor energy-linked fluorescence quenching. Neither EDTA treatment nor genetic loss of the Mg2+atpase causes a reduction in respiration. Purified Mg2+ATPase from strain 7 can bind to EDTA-treated membrane vesicles from either strain 7 or NR70. This binding restored both calcium transport and fluorescence quenching, driven either by respiration or by ATP. Dicyclohexylcarbodiimide treatment mimics the effect of the Mg2+ATPase in the case of respiration-driven reactions. Treatment with EDTA, while not essential for the binding of the Mg2+ATPase to membrane vesicles of NR70, produced better restoration of both activities. The rate of restoration of fluorescence quenching showed a time lag which may indicate that binding of the Mg2+ATPase is a relatively slow process. Antiserum prepared against the Mg2+ATPase inhibited the quenching of quinacrine fluorescence when driven by ATP but not when driven by respiration. Addition of antiserum prior to addition of Mg2+ATPase prevented the restoration of fluorescence quenching, whether driven by respiration or ATP. These results clearly show that MG2+ATPase has an important role not only in catalyzing ATP synthesis and hydrolysis but also in maintaining the energized membrane state. | US |
The significance of central noradrenergic, dopaminergic and serotonergic neural systems for the locomotor stimulant effects of methylphenidate was investigated in the rat. In order to study the role of brain catecholamines, rats were pretreated with reserpine (2.5 mg/kg) followed 24 hrs later by treatment with alpha-methyltyrosine (25 mg/kg) or U-14,624 (75 mg/kg), a dopamine-beta-hydroxylase inhibitor. In these experiments, methylphenidate stimulated motor activity was antagonized by alpha-methyltyrosine and enhanced after treatment with U-14,624, suggesting that release of newly synthesized dopamine is important to a locomotor stimulant action of methylphenidate. Evidence implicating brain serotonin in the actions of methylphenidate was obtained in rats pretreated with pargyline or p-chlorophenylalanine (PCPA). Administration of pargyline 1 hr prior to methylphenidate was found to reduce the locomotor activity induced by methylphenidate and this was antagonized by pretreatment with low doses of PCPA. Higher doses of PCPA caused a significant elevation of methylphenidate induced activity which could be reduced by 5-hydroxytryptophan. Destruction of serotonergic neurons with 5,7-dihydroxytryptamine also potentiated methylphenidate induced locomotion. These latter findings suggest that serotonergic fibers have an inhibitory function in brain. These results are discussed in relation to the possible mechanism by which methylphenidate may act in hyperkinesis. | US |
Locomotor activity induced by d-amphetamine was found to be potentiated by food deprivation, a tryptophan-free diet, p-chlorophenylalanine and drugs proposed to antagonize serotonin receptors in brain. Administration of L-tryptophan 1 hour prior to d-amphetamine injection was found to antagonize the enhanced response to d-amphetamine in starved rats and in rats which had tryptophan removed from their diet. However, tryptophan did not block the potentiated response to d-amphetamine in animals pretreated with p-chlorophenylalanine. These findings suggested that the antagonism of d-amphetamine-induced activity by tryptophan in starved rats and rats fed a tryptophan-free diet was not due to a nonspecific depressant effect of the amino acid. Since accumulation of d-amphetamine and its metabolites was not affected by any of the treatments which enhanced its activity, it seems unlikely that an alteration in the metabolism of d-amphetamine can explain these findings. The present work provides additional support for the view that serotonergic fibers play an important role in the actions of d-amphetamine. | US |
Using solid state radioimmunoassays developed by the first author, changes in the urine level of plasmin-like substances (PLS) and fibrin degradation products (FDP) before and after human kidney transplantation were determined in 49 transplant patients. Averages of urine PLS and FDP in a normal population of 51 persons were 0.13+/-0.10 (SD) and 0.14+/-0.07 microng/ml, respectively. In all transplant patients there was an initial rise of both PLS and FDP in urine immediately after transplantation. This elevation peaked on days 4 and 5 and the PLS and FDP levels returned to normal range within 2 weeks in patients without evidence of rejeciton. A secondary rise of urine PLS was detected before or with a rise in serum creatinine in all of the patients experiencing rejections. Of 11 patients who showed a rejection episode within 2 weeks of transplantation, the secondary rise of urine PLS was detectable in 55% of the patients slightly before the serum creatinine level changes; of 6 patients with a rejection episode more than 2 weeks after transplantation, 100% showed a secondary PLS rise 6.7+/-2.3 (SE) days before the serum creatinine increased. The appearance of the secondary rise of urine FDP in the rejecting recipients was slightly later than the rise of PLS. Serial determination of urine PLS levels following human kidney transplantation appears to be an early index of rejections which occurs more than 2 weeks after transplantation, although the clinical usefulness of this measurement is probably limited. | US |
The nucleotide sequence of mitochondrial DNA of a cytoplasmic "petite" mutant of Saccharomyces cerevisiae is reported. The DNA has a repeat length of 1060 base pairs and contains a genetic marker (oli-1) for the ATPase proteolipid. The nucleotide sequence reveals the presence of part of the structural gene of the subunit-9 proteolipid of the ATPase complex and an extended A+T-rich region adjacent to the carboxyl-terminal end of the gene. The structural gene sequence agrees with the primary structure of the protein. These studies point out the feasibility of using the DNA of appropriately marked "petite" mutants to obtain the sequence of mitochondrial genes. | US |
We have studied the interaction of highly purified Int protein with DNA restriction fragments from the lambda phage attachment site (attP) region. Two different DNA sequences are protected by bound Int protein against partial digestion by either pancreatic DNAase or neocarzinostatin. One Int binding site includes the 15 bp common core sequence (the crossover region for site-specific recombination) plus several bases of sequence adjoining the core in both the P and P' arms. The second Int-protected site occurs 70 bp to the right of the common core in the P' arm, just at the distal end of the sequence encoding Int protein. The two Int binding sites are of comparable size, 30-35 bp, but do not share any extensive sequence homology. The interaction of Int with the two sites is distinctly different, as defined by the observation that only the site in the P' arm and not the site at the common core region is protected by Int in the face of challenge by the polyanion heparin. Restriction fragments containing DNA from the bacterial attachment site (attB) region exhibit a different pattern of interaction with Int. In the absence of heparin, a smaller (15 bp) sequence, which includes the left half of the common core region and the common core-B arm juncture, is protected against nuclease digestion by Int protein. No sequences from this region are protected by Int in the presence of heparin. | US |
The primary IgM antibody response to sheep erythrocytes in vivo as well as in vitro is markedly decreased in the spleen cells of pregnant mice, compared to age-matched female controls. Decreased antibody synthesis appears to be mediated by nonspecific suppressor cells, because the addition of pregnant spleen cells to the normal spleen cell cultures causes a significant suppression of plaque-forming-cell responses of the normal spleen cells. Suppressor cell activity was not observed in lymph nodes of pregnant mice. At least two populations of pregnant spleen cells were shown to exert a suppressor cell activity; one is T lymphocytes and the other a nylon-adherent cell present in the B-cell-enriched macrophage-depleted fraction. Pregnant spleen cells cultured in vitro were shown to secrete a soluble suppressive factor(s) into the supernatant medium. | US |
The assimilation of iron, a growth-limiting metal ion of the cytotoxic marine cyanobacterium, Gomphosphaeria aponina, has been examined in both static and steady-state cultures using 59Fe (III). Uptake of iron by cells followed first-order kinetics, and biphasic (absorption and uptake) behavior was observed as suggested by noted differences between cultures incubated in the light and in the dark. Iron removal in illuminated cultures was rapid, occurring at rates comparable to exponential growth rates. Although uptake was mediated by a chelating agent (EDTA), synthesis and iron assisted transport by hydroxamate-type siderophores was not involved in the uptake of iron by cells, as determined by standard chemical and biological assays of iron deficient cultures. The ecological implications of this research is considered with respect to the cytotoxic antagonism between the cyanobacterium and Florida's red tide organism, Pytochodiscus brevis (Gymnodinium breve). | US |
Narrow definitions of schizophrenia increase homogeneity at the expense of leaving unclassified many patients with shizophrenic symptoms. Family history and follow-up studies indicate that many such patients ought to be classified with those having affective disorders. This study determines morbid risks for affective disorder and schizophrenia in first degree relatives of patients with chart but not research diagnoses of schizophrenia. Comparisons with morbid risk figures for relatives of individuals satisfying research criteria for depression, mania or schizophrenia indicate that the 'non-Feighner schizophrenia' group is probably too heterogenous to be classified entirely as affective disorder or as schizophrenia. | US |
In a sample of middle class individuals seeking martial and sexual counseling, 30% had diagnosable psychiatric illness, including 14% who had depressions at the time of interview. Those with psychiatric syndromes were significantly more likely to have prescribed psychoactive than those without these syndromes. Those with depression were more likely to have received diazepam and similar drugs than antidepressants. The same was true for those with other syndromes but in many of these cases, diazepam or other antianxiety agents seemed more appropriate. Thus, affective disorder might well be the psychiatric syndrome for which these drugs are most often inappropriately prescribed. Inappropriate treatment is a matter of concern in an illness which is potentially fatal. | US |
A factor analysis of the 90-item version of the Hopkins Symptom Checklist, performed on the pretreatment self-ratings of nonpsychotic outpatients with symptoms of depression and anxiety, revealed the presence of 8 clinically meaningful factors. These eight orthogonal factors each contained at least 5 items with loadings above 0.40 and explained 4.5% or more of the matrix variance. They were labeled Somatization, Phobic-Anxiety, Retarded Depression, Agitated Depression, Obsessive-Compulsive, Interpersonal Sensitivity, Anger-Hostility and Psychoticism. | US |
Investigations have been carried out on the action of several steroid hormones on lymphocyte functions in inbred strains of mice. The recognitive, proliferative and effector phases of allogeneic cell interactions in vitro were assessed using a mixed lymphocyte reaction (MLR) and cell-mediated lympholysis (CML). In MLR containing Balb/c (responder) and C57bl/6 (stimulator) splenocytes DNA synthesis was markedly reduced in the presence of progesterone, cortisol or estradiol. In CML, progesterone and estradiol (1-5 microgram/ml) blocked in vitro generation of cytotoxic lymphocytes, while cultures with cortisol were partially inhibited. None of these hormones suppressed the cytotoxic activity of previously sensitized effector cells generated in vitro. Cultures containing testosterone expressed both normal DNA synthesis in MLR and cytotoxic activity in the CML test. These findings suggest a selective pattern of immunosuppression by sex hormones which may be important in preventing graft rejection or graft-versus-host interactions which may arise as a consequence of fetal engraftment during pregnancy. | US |
The effect of CMNQ was studied on mitochondria isolated from S-180 ascites tumor cells. It was found that the primary metabolic event upon addition of CMNQ to S-180 mitochondria was a stimulation of oxygen uptake. The oxygen utilization rate was maximized at about 50 nmoles CMNQ/mg protein; at doses higher than this, inhibition of respiration was observed relative to the stimulation of respiration produced by CCCP. It was also up to 50 nmoles CMNQ/mg protein. S-180 ATPase activity is stimulated maximally by 125 nmoles CMNQ/mg protein; at doses higher than this, slight inhibition of the ATPase activity relative to the stimulation produced by CCCP is seen. In vivo treatment of CMNQ to tumor bearing animals leads to a significant reduction of in vitro S-180 cellular respiration rates. The data presented in this work coupled with previously published reports involving CMNQ support the proposal for a mitochondrial level of action for this bioreductive alkylating antineoplastic agent. | US |
The immunosuppressive action of chlorphenesin was investigated in a wide variety of in vitro assays for cellular immunity in humans and mice. Chlorphenesin, at doses of 20-50 micrograms/ml, inhibited mitogenic responses of both mouse and human B and T cells. These doses did not kill cells exposed to the drug for 72 hr. Mixed lymphocyte reactions in inbred strains of mice and in unrelated humans were also inhibited at concentrations of about 50 micrograms/ml. However, the generation of cytotoxic T cells in cell-mediated lympholysis assays was not inhibited to the same degree as proliferation in mixed lymphocyte reaction and the cytotoxic potential of presensitized mouse T cells for allogeneic targets was totally unaffected. These studies suggest that chlorphenesin may have a broad spectrum of suppressive effects both on T and B cells and that the predominant inhibition of proliferative responses in these cells may reduce the expansion of clones of immunocompetent cells in vivo. | US |
Following a transient increase in relative mitochondrial volume which lasts but a few days, cardiac hypertrophy in response to pressure- or volume-overload is characterized by a preferential growth of contractile elements resulting in a decreased mitochondria/myofibrils volume ratio. At least under some conditions, the number of mitochondria/unit area increases as does the organelles surface/volume ratio. If the functional overload persists for a long period of time, e.g. 12-15 months, relative mitochondrial volume is decreased further. Unlike the imbalance in growth of mitochondria and myofibrils, the total surface area (sarcolemma plus T-System) enlarges in proportion to the increase in cell volume. While most of the components which are altered during hypertrophy become normalized as cardiac hypertrophy regresses, the process is slower than the imbalance associated with cellular enlargement. Most models of cardiac hypertrophy differ from normal growth in that the latter is characterized by proportional growth of all cellular components. In contrast, hypertrophy associated with exercise results in proportional growth in cellular components. The idea that growth of various cellular organelles is regulated by separate mechanisms is gaining support. Both sympathectomy and noreprinephrine depletion normalize the growth of mitochondria and myofibrils, while thyroxine treatment stimulates a preferential growth of mitochondria. Current evidence, therefore, suggests that myocardial cell growth probably involves complex processes which may vary with different conditions associated with the stimulus invoking enhanced cellular enlargement. | US |
Present concepts concerning DNA synthesis in the heart have been reviewed, and a speculative theory presented involving control of DNA synthesis in the developing heart. Research describing DNA synthesis in myocytes of the weanling rat heart undergoing hypertrophy has been presented. Its possible use for testing the control theory is suggested. | US |
Over the past ten years knowledge of the biochemistry of cardiac sarcoplasmic reticulum vesicles has been considerably extended. In almost all respects the Ca2+ pump of cardiac sarcoplasmic reticulum shows striking similarities to the Ca2+ pump of skeletal muscle sarcoplasmic reticulum. On the other hand, Ca2+ release mechanisms seem to be more complex in cardiac than in skeletal sarcoplasmic reticulum. Future research undoubtedly will involve characterizing the function of the many additional proteins present in cardiac sarcoplasmic reticulum, and determining possible roles for these proteins in regulating Ca2+ uptake and Ca2+ release by these membranes. | US |
Myosin isolated under phosphorylation conditions, showed an additional band of phosphorylated light chain. In the case of cardiac myosin, LC2 is the phosphorylated light chain whereas in skeletal myosin, it is the 18,000 dalton component known as DTNB light chain. There are no differences in K+-EDTA and Ca2+ activated myosin ATPase of cardiac and skeletal of control and phosphorylated myosins. Our experiments showed that the rat heart and skeletal muscle myosins isolated under phosphorylating conditions exhibited high phosphate content which is associated with higher actin activated Mg2+ ATPase activity of myosin as compared to control. Control myosin phosphorylated using myosin light chain kinase and Ca2+ also showed high actin activated myosin ATPase activity. Beef heart myosin isolated in the presence of phosphate buffer, also exhibited a higher level of phosphate followed by an increase in actin activation as compared to myosin isolated in the absence of phosphate buffer. All these experimental data suggest that there is a direct relationship between actin activation and the amount of phosphate incorporated as a result of phosphorylation. | US |
We have demonstrated alterations in the composition of certain groups of nuclear no-histone proteins which could account for the changes in template activity. Further identification of the individual proteins essential for this regulation will aid us in our understanding of the mechanism of myocardial cell growth during hypertrophy. We also have demonstrated the existence of several different RNA polymerase enzymes and have characterized them. The question of de novo synthesis or activation of preexisting enzyme remains unanswered. The delay in changes in activity which we found is also of great interest and may provide information as to the mechanism of increased RNA polymerase activity. The regulation of transcription can occur by changes either in the activity of the chromatin template or in the activities of the various RNA polymerase. Our studies thus far strongly suggest that during the development of hypertrophy both regulatory mechanisms are operative. Furthermore, this appears to be a bimodal function; initially there are changes only in the template and only later do changes in enzyme activity occur. To our knowledge this is the first demonstration of this form of regulation of RNA synthesis in myocardial tissue. | US |
Simple, rapid colorimetric tests for lysogenic induction (the derepression of a latent bacterial virus) are described. A quantitative test and a more rapid semiquantitative test are based on the assay of the beta-galactosidase synthesized from lacZ gene fused to an operon under lambda repressor control. These biochemical "inductests" are suitable for screening programs designed to detect agents that damage DNA and that are of potential interest in carcinogenesis and cancer chemotherapy. | US |
An initial examination was made of the hypothesis that one action of cigarette smoke components on pulmonary alveolar macrophage function involves the inhibition of contractile protein adenosine triphosphatase activity. Pulmonary alveolar macrophage calcium-dependent adenosine triphosphatase activity, magnesium-dependent adenosine triphosphatase activity, sodium-potassium-dependent adenosine triphosphatase activity, phagocytosis, and cell adhesiveness were measured in the presence of cigarette smoke, acrolein, ouabain, and ethacrynic acid. Calcium-dependent adenosine triphosphatase activity, magnesium-dependent adenosine triphosphatase activity, phagocytosis, and adhesiveness were inhibited by smoke and ethacrynic acid, but not by ouabain. Acrolein, a component of smoke, inhibited phagocytosis, adhesiveness, and calcium-dependent adenosine triphosphatase activity, indicating that another component of smoke must be effective at inhibiting magnesium-dependent adenosine triphosphatase activity. Sodium-potassium-dependent adenosine triphosphatase activity was inhibited by ouabain and ethacrynic acid, but not by smoke or acrolein. Finally, sulfhydryl reagents at least partially protected the macrophages against the inhibitory actions of each of the agents. The results are in accord with recently obtained experimental evidence that calcium-dependent adenosine triphosphatase and, perhaps, magnesium-dependent adenosine triphosphatase play a role in phagocytosis. The data also suggest that smoke components affect a number of macrophage activities, including adhesion and phagocytosis, by altering the cell's contractile apparatus. | US |
The cross-bridge formalism of T. Hill has been incorporated into the nonlinear differential equations describing planar flagellar motion in an external viscous medium. A stable numerical procedure for solution of these equations is presented. A self-consistent two-state diagram with curvature-dependent rate functions is sufficient to generate stable propagating waves with frequencies and amplitudes typical of sperm flagella. For a particular choice of attachment and detachment rate functions, reasonable variation of frequency and wave speed with increasing viscosity is also obtained. The method can easily be extended to study more realistic state diagrams. | US |
Spleen cells obtained from mice injected with cyclophosphamide (200 mg/kg body weight) suppressed the secondary IgG antibody response of memory cells to a T-dependent antigen, DNP-HGG, in Millipore diffusion chambers. Significant suppression (greater than 50%) was found from 5 to 14 days following cyclophosphamide treatment, with peak suppression (86%) on day 7. The primary IgM antibody response to DNP-Ficoll, a T-independent antigen, was not suppressed by these cells. In contrast, suppression was observed in the primary IgM response to sheep red blood cells, a T-dependent antigen. In addition, treatment of the suppressor cell population with anti-Thy-1 serum and complement did not inhibit suppressor activity. We concluded that the suppressor activity was not attributable to a typical T cell, and that the target of suppression was not a B cell. Preliminary evidence suggests that the suppressor activity is regulated, directly or indirectly, by a T cell. | US |
It has been suggested that hCG is a trophic hormone for the fetal zone of the human fetal adrenal gland. To test this hypothesis, the isolated fetal zones of adrenals from eight fetuses (12-17-week gestation age) were superfused in the presence or absence of hCG. Dehydroepiandrosterone sulfate (DHAS) was measured in the superfusion effluent. A significant increase in DHAS production was observed in the presence of hCG. DHAS secretion decreased during the first 60 min in the control and experimental superfusions from 83 +/- 10.0 (mean +/- SE) to 71 +/- 8.0, and from 90 +/- 9.0 to 70 +/- 6.0 ng/100 mg/ml, respectively. In the presence of hCG (250 ng/ml), DHAS secretion increased significantly (P less than 0.01) over the controls to 116 +/- 12.0 at 120 min, and remained above the controls thereafter. These results support the hypothesis that hCG is one of the regulators of DHAS production by the human fetal adrenal gland early in gestation. As we found that ACTh stimulated DHAS secretion in a previous study and as there is indirect evidence for a role of ACTH in DHAS regulation late in pregnancy, these observations suggest dual regulation by hCG and ACTH early in pregnancy, and a possible transition to ACTH regulation of the fetal zone of the human fetal adrenal after midgestation. | US |
Sixty-six bipolar I lithium clinic patients were studied for a history of psychotic symptoms at some time during the course of their illness. Agreement between different sources of information was calculated, and the patient population was divided into psychotic and non-psychotic subgroups. Probability of remaining well on lithium for the different subgroups was analyzed by the life table method. Psychosis during mania appeared to be associated with especially good early lithium prophylaxis. | US |
Previous investigators have reported a high prevalence of depressive symptoms in drug-dependent patients. Given the responsiveness of depressive disorders to both psychological and pharmacological treatments, it is desirable to find an economical, efficient screening instrument to detect depressive disorders in this population. In this study, 6 depression symptom screening scales (Beck Depression Inventory, Hamilton Depression Scale, Raskin Depression Scale, Degree of Illness Rating, Symptom Checklist 90 Overall, and Depression Subscale) based on either clinician interview or patient self report, were compared according to their utility in detecting cases of depression among 64 applicants for treatment at a substance abuse treatment unit of a community mental health center. The criteria for a case of depression were the Research Diagnostic Criteria (RDC) which are specified and operationalized. Cases identified using previously described cutoff scores on the screening scales were compared to rates based on the RDC and sensitivity and specificity were determined. The results showed that: (1) although the sensitivity of the symptom scales was applicable, ranging from 65--94%, the specificity was less impressive, ranging from 39--61%, and (2) the Beck Depression Inventory, a 13-item patient self report was the most sensitive and specific and is recommended for screening drug-dependent populations for depression. | US |
Thirty-four recent rape victims were assessed for depressive symptomatology using a well-validated self-report instrument in combination with formal psychiatric evaluation. Fifteen subjects were found to be moderately or severely depressed when measured on the self-report questionnaire. A closer examination of these 15 subjects revealed that 8 were suffering from a major depressive disorder. The authors emphasize that all clinicians working with rape victims should be alert to the emergence of depression in this population. | US |
A family history study of second-degree relatives of 19 patients with anxiety neurosis (panic disorder) and 19 controls showed a morbidity risk of 9.5% among the former compared with 1.4% among the latter. These risks were approximately half those found among first-degree relatives. Female relatives were at higher risk for anxiety neurosis. The risk for other psychiatric illnesses did not differ between the relatives of anxiety neurosis and controls. | US |
The Slater computational model for use in distinguishing between polygenic inheritance and the effects of a single dominant gene with incomplete penetrance was applied to 15 kindreds of anxiety neurosis (panic disorder). The number of observed unilateral pairs (two ancestral cases from one side of the kindred) was significantly greater than the number expected. Therefore, these results suggest a dominant mode of transmission for anxiety neurosis. | US |
One hundred sixty-eight patients with primary affective disorder were studied regarding history of alcohol-related problems. Alcohol-related problems were identified in 19 patients. We found that the morbid risk for alcoholism was significantly increased among relatives of male patients with drinking problems as compared to relatives of male patients without drinking problems. Our data suggest that psychiatric illness in relatives of probands with severe bipolar illness tends to be affective disorder tends to include alcoholism plus affective disorder. | US |
A restrospective chart study and follow-up telephone interviews were used to compare the relapse rates of unipolar depressives who had received either lithium or tricyclics following ECT. The results showed no difference between the two treatment groups. The literature on ECT was reviewed in the light of the results from the present study. We concluded that ECT followed by either lithium or a tricyclic antidepressant is a more effective treatment for unipolar depression than ECT alone. | US |
A principal component analysis was carried out on symptom ratings and selected history items from 79 depressed patients. Three interpretable factors were obtained. The first was a general factor reflecting severity. The second a bipolar factor contrasting endogenous and neurotic depression, the third a bipolar contrasting anxiety and depressive symptoms. These replicate similar factors found previously in a different sample. The stability and predictive value are emphasized of other factors as well as the endogenous-neurotic dimension. | US |
A regimen or aminoglutethimide in combination with replacement glucocorticoid has been used to suppress adrenal steroidogenesis in postmenopausal women with metastatic breast carcinoma. During acute and chronic treatment with aminoglutethimide, the levels of the delta 4-steroids [progesterone (P), 17 alpha-hydroxyprogesterone (17-delta 4-P), and androstenedione (delta 4-A)] and the delta 5-steroids [dehydroepiandrosterone (DHEA), dehydroepiandrosterone-sulfate (DHEA-S), and 17 alpha-hydroxypregnenolone (17-delta 5-P)] were determine. In the total group of women, the plasma levels of P and delta 4-A increased 2- to 3-fold (P less than 0.05) while 17-delta 4-P rose 10-fold (P less than 0.01) from basal concentrations of 0.65 +/- 0.07 to 6.48 +/- 1.46 ng/ml during the initial 2 weeks of therapy with aminoglutethimide (AG) and dexamethasone. These three steroids then fell to basal levels during chronic treatment (P and 17-delta 4-P) or were suppressed (delta 4-A; P less than 0.001). In contrast, the levels of delta 5-steroids (17-delta 5-P, DHEA, and DHEA-S) were reduced 3- to 5-fold during the initial 2 weeks of therapy and remained suppressed throughout. The relative levels of certain delta 5- and delta 4-steroids pairs were then examined. The ratio of 17-delta 5-P to 17-delta 4-P decreased from baseline values of 2.15 +/- 0.35 to 0.38 +/- 0.21 ng/ml (P less .02) with the initiation of therapy and remained low thereafter. A similar pattern for the ratios between DHEA and delta 4-A, and DHEA-S and delta 4-A was observed. This may indicate that the regimen of AG treatment utilized may facilitate the activity of the 3 beta-ol-dehydrogenase, delta 5- to delta 4-isomerase, and accelerate the conversion of delta 5- to delta 4-steroids. The patterns of suppression of the plasma delta 4- and delta 5-steroids in oophorectomized and spontaneously postmenopausal patients with intact ovaries were analyzed separately. The plasma levels of progesterone were higher during the first 2 weeks of therapy in surgically castrate women than in spontaneously postmenopausal women (0.72 +/- 0.25 vs. 0.47 +/- 0.20 ng/ml). A similar pattern was observed for 17-delta 4-P, DHEA, and DHEA-S indicating that the adrenals might contribute to this increase. In contrast, during chronic treatment the levels of all steroids were lower in surgically castrate women than in those with intact ovaries. This suggested residual ovarian steroid during AG administration. | US |
The alteration in circulating levels of PRL, GH, TSH, and cortisol was studied after the oral administration of muscimol (3-hydroxy-5-aminomethylisoxazole) to human subjects with Huntington's disease (n = 4) and chronic schizophrenia (n = 5). PRL levels rose significantly in a dose-dependent fashion within a 120-min time interval. GH rose significantly but modestly over the same time interval, whereas TSH and cortisol levels remained unchanged. Since muscimol is thought to be a potent and specific gamma-aminobutyric acid agonist, these data indicate that gamma-aminobutyric acid-mediated neural transmission may function to stimulate the release of plasma PRL and GH in human subjects. | US |
This study focuses on counselees' knowledge of the Down syndrome before receiving genetic counseling. Data were collected from 47 mothers of children with the Down syndrome using a structured interview of 13 open-ended questions. This instrument was found to be both internally reliable and consistent. Results of this study document the enormous variation of counselees' knowledge of the Down syndrome before genetic counseling and show that this is positively associated with their educational background. Counselees with more than a high school education knew about 60% of the genetic information pertaining to the diagnosis before genetic counseling, while those with less than a high school education knew only 23% of this information before counseling. These results indicate that the better educated counselees are less apt to need to learn basic genetic information and may seek out genetic counseling services for other reasons. Possible motives are seeking knowledge confirmation, emotional support, and personalization of the information. | US |
From February 1969 to August 1976, we studied 1,048 amniotic fluids. Of these, 958 (91.4%) were primarily for prenatal cytogenetic diagnosis. Cytogenetic studies were attempted in 1,021 cases; the diagnosis was successful in 1,000 of these. The failure rate of obtaining a diagnosis from the amniotic fluid cell culture of the first amniocentesis was 5% (50 cases); 29 cases had a repeat tap and successful diagnosis was achieved in all. In 21 cases, a repeat tap was refused. Thus, the overall failure rate of obtaining a final cytogenetic diagnosis was 2.06% (21/1,021). There were 32 fetal losses after amniocentesis including 16 spontaneous second trimester abortions, 7 fetal deaths in utero and 9 stillbirths. In two additional cases, fetal death had occurred before amniocentesis. This number of fetal losses does not exceed the number that would be expected in the same maternal age group without amniocentesis. In our series, the frequencies of trisomy in maternal age groups 40 years and over, 37-39 years, 35-36 years, and under 35 years were 4.5, 3.14, 0 and 0% respectively. These frequencies are comparable to those reported from other prospective prenatal studies and higher than those of retrospective live born studies. Various problems and pitfalls in prenatal cytogenetic diagnosis are discussed. | US |
A procedure was developed for isolating nuclei from either the conidial or germinated conidial growth phase of Neurospora crassa. A frozen conidial suspension was lysed by passage through a French pressure cell, and the nuclei were freed from the broken cells by repeated homogenization in an Omni-Mixer. Pure nuclei were obtained from the crude nuclear fraction by density banding in a Ludox gradient. The final nuclear yield was 20 to 30%. The nuclei had a deoxyribonucleic acid (DNA):ribonucleic acid (RNA):protein ratio of 1:3.5:7 and were active in RNA synthesis. The nuclei, stained with the DNA stain 4,6-diamidino-2-phenylindole, appeared under fluorescence microscopy as bright blue spheres, 1 micron in diameter, essentially free from cytoplasmic attachments. Chromatin extracted from the nuclei in a 70 to 75% yield by dissociation with 2 M sodium chloride and 5 M urea had a DNA:RNA:protein ratio of 1:1.05:1.7. Chromatin reconstituted from this preparation exhibited a level of RNA polymerase template activity lower than that of pure Neurospora DNA, but the maximum level of reconstitution obtained was only 10%. Fractionation of Neurospora chromatin on hydroxylapatite separated the histones from the chromatin acidic proteins. The normal complement of histone proteins was present in both the reconstituted and dissociated chromatin preparations. The acidic protein fraction exhibited a variety of bands on sodium dodecyl sulfate gel electrophoresis ranging in molecular weight from 15,000 to 70,000. The gel pattern was much more complex for total dissociated chromatin than for reconstituted chromatin. | US |
The antimicrobial susceptibility of a low-laboratory-passage, slow-growing, genital Chlamydia trachomatis strain was studied by five different procedures with the use of McCoy cells pretreated with 5-iodo-2-deoxyuridine. The effects of antimicrobial agents when added to cultures on day 0 or day 2 after inoculation with C. trachomatis and the effects of washing and reincubating treated cultures in antimicrobial-free media were investigated. Tetracycline and erythromycin inhibited C. trachomatis growth at concentrations attainable in human serum, although their actions were reversible and significantly higher concentrations were needed to "cure" 48-h infected cultures. On a weight basis, spectinomycin was relatively ineffective in inhibiting C. trachomatis growth. The minimal inhibitory concentration of penicillin measured by our assay procedures was higher than that reported by other investigators. The five assay procedures used in this study were reproducible, and our results indicate that we can obtain more pertinent information about the efficacy of an antimicrobial agent in controlling C. trachomatis growth by using a combination of these assays than by simple minimal inhibitory concentration determinations, as had been previously described by other investigators. In addition, we failed to demonstrate changes in tetracycline susceptibility of C. trachomatis isolates from two patients who had received tetracycline therapy. | US |
Thymocytes and macrophages can be involved in the generation and perpetuation of autoimmune disorders in many ways. Evidence continues to mount for their active role. Although a significant association seems likely, one should remember that B cells and complement-directed granulocyte destruction may be equally if not more important. Furthermore, a combination of processes is not precluded by any fundamental biological law. Appropriate and effective therapy requires acceptance of this concept and further studies should attempt to define the interrelationships of these processes and focus upon methodology to determine their relative roles in a given situation. | US |
Frequently, the diagnosis of disease of the low back is a difficult matter due to the multitude of factors affecting the patient's symptoms. In this report an attempt is made to use biomechanical testing to objectify certain aspects of the diagnostic process. Our philosophy is that a biomechanical assessment is one of the disciplines that should be brought to bear on the low-back pain patient. A group of biomechanical tests has been developed by adding quantitative measurement techniques to certain standard clinical maneuvers: muscle testing, range of motion testing, and straight leg raising testing. Moire fringe topography is employed for studying posture. Results of application of these techniques to 117 patients and 10 controls indicate potential utility in the method for epidemiologic and clinical research. | US |
Ca++-uptake and Mg++-Ca++-dependent ATPase activity of skeletal muscle sarcoplasmic reticulum vesicles were reciprocally affected by increasing the oxalate concentration from 0 to 4 mM. At 0-0.1 mM oxalate approximately 17% of the calcium was removed by the vesicles from the medium while the ATPase activity was maximal (approximately 0.66 mumoles Pi mg-1 protein min-1). Between 0.1 to 0.2 mM oxalate the ATPase activity was reduced to one-fifth but the uptake rose sharply and 100% of the 45Ca++ was removed from the medium. The uptake was maintained at this level at oxalate concentrations greater than 0.4 mM but the ATPase activity remained inhibited. The kinetics of Ca++-uptake and ATPase activity were also differentially affected by oxalate. In the presence of oxalate, ruthenium red had only a very slight inhibitory effect on the calcium uptake. Addition of 0.1 mM EGTA removed 80% of the Ca++ from preloaded vesicles within 10 min. The formation of insoluble Ca-oxalate salt on the surface of the vesicle is suggested by these results. Calculations based on the Ksp of the calcium oxalate salt are presented to show its formation and the possible speciation of a Ca-oxalate complex which may affect the Ca++-uptake and ATPase activity. | US |
A rotational viscometer was used to study the effects of shear stress on platelets in human platelet-rich plasma (PRP). For 5-min exposure times, shear stresses above 160 dynes/cm2 induced platelet lysis (as determined by release of platelet lactic dehydrogenase). For 30-s exposure times, shear stresses greater than 600 dynes/cm2 were required to induce platelet lysis. The platelet counts of sheared PRP were decreased to as low as one-fifth the original count due largely to shear-induced aggregation. The count is a minimum at intermediate stress levels (200-400 dynes/cm2). Higher stresses induce disaggregation as well as lysis. The diminution in the counts was partially reversed in 2 h incubation after cessation of shearing. Experiments were carried out with three different viscometer configurations so that the shear stress and the solid surface area access could be varied independently. Surface access was not a significant variable in the conditions of the experiments. Thus aggregation and lysis may be induced by stress effects alone as well as by solid surface effects. The results also show that the response of platelets to shear stress is strongly dependent on exposure time. Platelets are much less resistant to shear stress than red cells for relatively long exposure times. However, the converse is true for very short exposure times. | US |
The specific activity of the lysosomal enzyme N-acetyl-beta-D-hexosaminidase was determined in the caput and cauda of the epididymis of rats as a function of age. The activity peaks at six weeks of age in both parts of the epididymis but is higher in the cauda. The results indicate a relationship between changes occurring in sperm in the epididymis and the lysosomal enzymes. | US |
1. beta-N-acetylhexosaminidase isoenzymes from the gastropod, T. cornutus, were purified and their properties studied. 2. The two isoenzymes, designated A and B were separated by DEAE-Sephadex column chromatography and further purified by CM-cellulose, Concanavalin-A-Sepharose-4B and Sephadex G-200 column chromatography. 3. beta-N-Acetylhexosaminidase A and B were purified 416 and 208 fold, with yields of 10.6 and 5.1%, respectively. 4. The two isoenzymes appear homogeneous on polyacrylamide gel electrophoresis, with the A form migrating faster towards the anode than the B form. 5. The purified isoenzymes are virtually free of all other common glycosidase contaminations. 6. The apparent molecular weight of both beta-N-acetylhexosaminidase A and B is about 100,000 when estimated with gel filtration column chromatography and the pH optimum for both is 4.0. 7. Both beta-N-acetylhexosaminidase isoenzyme activities are stimulated by Cl-, Br-, F-, I- and NO3-, and inhibited by Hg+, Ag+, Fe3+, N-acetylglucosamine and N-acetylgalactosamine. 8. The Km values of beta-N-acetylhexosaminidase A and B for the substrate p-nitrophenyl-beta-2-acetamide-2-deoxy-D-glucopyranoside were 2.9 and 3.2 mM, respectively. | US |
1. beta-Hexosaminidase (hex) structure was compared in various primates, using thin-layer isoelectric focusing on polyacrylamide gels and quantitative microcomplement fixation. 2. Isoelectric focusing revealed no intraspecies differences and similar interspecies patterns. 3. Hex A and B are evolving at a moderate, but equal, rate and in a manner consistent with accepted phylogenetic patterns. 4. Quantitative microcomplement fixation revealed a closer homology between human hex A and chimpanzee A or human hex B and chimpanzee hex B than between human hex A and human hex B. | US |
Fibroblast strains from 12 patients with xeroderma pigmentosum had lower than normal rates of DNA repair, as determined by autoradiographic studies of ultraviolet-induced unscheduled nuclear DNA synthesis. The nuclei in binuclear cells, obtained by fusing fibroblasts from certain pairs of these strains, had a greater rate of DNA repair than the nuclei of either strain's unfused mononuclear cells. These results indicate that complementary corrections of the strains' repair defects had occurred in the fused cells. Four complementation groups were found, indicating that at least four mutations caused decreased DNA repair among these 12 strains. The unfused mononuclear cells of each group had a characteristic rate of repair that differed from the rates of the other groups. | US |
A nineteen year old female underwent 85 to 90 per cent partial hepatectomy to treat a minimal deviation hepatoma. Observations afterwards suggested that the limit of resection compatible with survival had been reached. She recovered perfect health after many months, although liver regeneration was not complete. Severe but eventually reversible alopecia and ascites developed postoperatively, undoubtedly as a complication of the massive hepatic resection. | US |
UV survival curves of adenovirus 2 using fused, complementing xeroderma pigmentosum (XP) fibroblast strains as virus hosts showed a component with an inactivation slope identical to that given by normal cells. This component was not observed when the fibroblasts were not fused or when fusion involved strains in the same complementation group. Extrapolation of this component indicated that at zero dose 3% of the viral plaque-forming units had infected cells capable of normal repair. These results suggest that 3% of the cells were complementing heterokaryons, a value similar to that actually observed by autoradiographic analysis of UV-induced unscheduled DNA synthesis. Thus, heterokaryons formed from XP fibroblasts belonging to different complementation groups are as capable of restoring biological activity to UV-damaged adenovirus 2 as are normal cells. | US |
Two mutants with specific defects in cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase; EC 1.9.3.1) have been isolated from cultures of Saccharomyces cerevisiae exposed to the mutagens ethyl-methane sulfonate and Mn++. The mutations have been shown to be extranuclear by two criteria. The phenotype persists in diploids formed by a cross with a p-o strain of yeast of the opposite mating type. Tetrad analysis indicates a non-Mendelian segregation (4:0 and 0:4) of the mutations. Both mutants show a total absence of cytochrome oxidase activity and of spectral cytochromes a and as. One of the mutants has been shown to be missing a polypeptide synthesized by mitochondria. The migration of this protein on polyacrylamide gels corresponds to the highest-molecular-weight subunit of cytochrome oxidase. | US |
The kinetics of virus labeling was used to study the maturation of viral RNA in the Rickard strain of feline leukemia virus. Viral RNA labeled over differing intervals was characterized by gel electrophoresis and velocity sedimentation in sucrose gradients made up in aqueous buffer and 99% dimethyl sulfoxide. Labeled virus was found within 30 min after adding radioactive uridine to the cells and production of labeled virus reached a maximum at 4 to 5 h after pulse labeling. Native RNA from feline leukemia virus resolved into three size classes when analyzed by electrophoresis on 2.0% polyacrylamide-0.5% agarose gels: a 6.2 x 10(6) to 7.1 x 10(6) mol wt (50 to 60S) class, an 8.7 x 10(4) mol wt (approximately 8S) class, and a 2.5 x 10(4) mol wt (4 to 5S) class. From two experiments during which RNA degradation appeared minimal, these made up to 57 to 76%, 2 to 5%, and 6 to 12%, respectively, of the total RNA. The 8S RNA in feline leukemia virus has not previously been reported. The 50 to 60S RNA from virus harvested after 4 h of labeling electrophoretically migrated faster and sedimented more slowly in sucrose gradients than did the same RNA species harvested after 20 h of labeling. This argues for an intravirion modification of the high-molecular-weight RNA. The large subunits of denatured viral RNA from both 4- and 20-h labeled-viral RNA electrophoretically migrated with an estimated molecular weight of 3.2 x 10(6) but sedimented with 28S ribosomal RNA (1.8 X 10(6) mol wt) when analyzed by velocity sedimentation through 99% dimethyl sulfoxide. | US |
A new operative procedure in renal surgery has evolved from the extensive recent experience in kidney transplantation. Bench surgery and autotransplantation have not been, as yet, fully exploited by surgeons caring for children. This approach to reconstruction of renal substance and renal vessels has as its greatest dividend conservation of kidney tissue. The operation has specific applicability for selected cases of: (1) renovascular hypertension; (2) congenital obstructive uropathy; (3) bilateral Wilms' tumor, and; (4) renal trauma in children. | US |
The enzyme, prenyltransferase, which normally catalyzes the addition of an allylic pyrophosphate to isopentenyl pyrophosphate, has been found to catalyze the hydrolysis of its allylic substrate. The rate of this hydrolysis is markedly stimulated by inorganic pyrophosphate. Competition experiments with 2-fluoroisopentenyl pyrophosphate and inorganic pyrophosphate demonstrated that inorganic pyrophosphate stimulated hydrolysis by binding at the isopentenyl pyrophosphate site. Hydrolysis carried out in H218O or with (1S)-[1-3H]geranyl pyrophosphate show the C-O bond is broken and the C1 carbon of geranyl pyrophosphate is inverted in the process. These results are interpreted to favor a carbonium ion mechanism for the prenyltransferase reaction. | US |
During the 11 1/2 year period ending 13 months ago, 93 consecutive patients were treated with orthotopic liver transplantation. Fifty-six of the recipients were 18 years old or younger, and the other 37 were adults. The most common indications for operation were biliary atresia, primary hepatic malignant tumor, chronic aggressive hepatitis and alcoholic cirrhosis. There has been a gradual improvement in results throughout the period of study, although to a satisfactory level. Twenty-seven of the 93 patients survived for at least one year after liver replacement with a maximum of six years, and 16 are still alive after 13 to 71 months. The 11 late deaths after one to six years were caused by chronic rejection, biliary obstruction, recurrence of hepatoma, systemic infection or hepatitis of the homograft. Rejection of the liver as judged by classical histopathologic criteria played a surprisingly small role in the heavy over-all mortality, accounting for less than 10 per cent of the deaths. Technical or mechanical problems, especially those of biliary duct reconstruction, were a far greater cause of failure, as were systemic infections. Six of the 37 adult recipients had lethal cerebrovascular accidents during, or just after, operation. When abnormalities of liver function developed in the postoperative period, the nearly automatic diagnosis of homograft rejection, in retrospect, proved to have been wrong in most instances. Further development of liver transplantation depends upon two kinds of progress. There must be reduction of operative and early postoperative accidents and complications by more discriminating patient selection, purely technical improvement and better standardization of biliary duct reconstruction. The second area will be in sharpening the criteria for the differnetial diagnosis of postoperative hepatic malfunction, including the liberal use of transhepatic cholangiography and needle biopsy. Only then can better decisions be made about changes in medication or about the need for secondary corrective surgical procedures. | US |
Thyrotropin-releasing hormone (TRH), administered intraperitoneally, was found to antagonize ethanol-induced sleep and hypothermia in mice without affecting brain ethanol content. This reduction of the actions of ethanol was also apparent after oral or intracisternal administration of TRH. In addition, TRH reduced ethanol-induced sleep in rats, hamsters, gerbils and guinea pigs. Evidence that the pituitary-thyroid axis is not necessary for the effects of TRH was provided by observations that hypophysectomy did not reduce TRH antagonism of ethanol narcosis and findings that neither triiodothyronine nor thyrotropin mimicked its action. Certain analogs of TRH, which have little effect on the pituitary, were also found to antagonize ethanol-induced sleep and hypothermia. Pretreatment with the antiadrenergic drugs, alpha-methyltyrosine, phentolamine and propranolol did not antagonize the ability of TRH to reduce sleep induced by ethanol. However, after intracisternal administration of atropine methyl nitrate, TRH no longer caused a significant reduction of sleep, even though TRH antagonism of the ethanol-induced hypothermia was still apparent. In contrast, central administration of other anticholinergic drugs, such as delta-tobocurarine and hexamethonium, reduced ethanol-induced sleep and this effect was additive with TRH. Carbachol also reduced ethanol sleeping time and this effect was also blocked by atropine methyl nitrate. The antagonism of ethanol-induced sleep by dibutyryl cyclic adenosine 3', 5'-monophosphate was significantly reduced but not blocked by atropine methyl nitrate. Results provide evidence that TRH has a direct extrapituitary action on brain and that both TRH and ethanol may interact with central cholinergic systems. | US |
The immature mammary glands of BALB/c female mice were treated with 7,12-dimethylbenz[a]anthracene (DMBA), 2 micrograms/ml, or 3-methylcholanthrene (10 micrograms/ml) for a 24-hr period at different times during the inital six days of lobuloalveolar growth in hormone-supplemented organ culture. Nodule-like alveolar lesions (NLAL) were detectable in 80% of the glands treated with DMBA (40% in 3-methylcholanthrene-treated glands) in the presence of insulin + prolactin + aldosterone + cortisol in the medium. No NLAL were present in dimethyl sulfoxide-treated control glands cultivated with the same hormones. The hormone combination insulin + prolactin + cortisol was unfavorable for NLAL induction by DMBA, and the combination of aldosterone + insulin + prolactin was only moderately conducive. Thus, the presence of cortisol with insulin + prolactin + aldosterone enhances NLAL incidence of mammary cells by DMBA. The highest incidence was found in glands that were treated with DMBA for 24 hr between the third and fourth day of culture, the period corresponding to the onset of the second wave of DNA synthesis in the gland. Cytotoxicity of DMBA was pronounced between 24 and 48 hr, when a high frequency of cells were in DNA synthesis, and survival of the cells after the cytotoxic effect of DMBA appeared to play a role in NLAL incidence. This suggests that DMBA-induction of NLAL in mammary glands in organ culture involves a complex carcinogen-hormone-cell cycle interaction. We emphasize that, although NLAL morphologically resembles the hyperplastic alveolar nodules of mouse mammary gland in vivo, the abilitity of NLAL to produce typical hyperactive alveolar outgrowth and mammary tumor after transplantation iv vivo remains to be determined. | US |
The high-molecular-weight subunit RNA of feline leukemia virus (Rickard strain) (FeLV-R) was analyzed for the presence of methyl groups. After purification of native 50-60S FeLV-R RNA on nondenaturing aqueous sucrose density gradients. FeLV-R 28S subunit RNA, doubly labeled with [14C]uridine and [methyl-3H]methionine, was isolated by centrifugation through denaturing sucrose density gradients in dimethyl sulfoxide. As calculated from their respective 3H/14C ratios. FeLV-R 28S RNA was methylated to the same degree as host cell poly(A)+ mRNA. When the 28S FeLV-R RNA was hydrolyzed to completion with RNase T2 or alkali, all of the methyl-3H chromatographed with mononucleotides on Pellionex-WAX, a weak anion exchanger. The methyl-labeled material co-chromatographed with 6-methyladenosine if the mononucleotide fraction obtained by Pellionex-WAX chromatography was hydrolyzed to nucleosides by bacterial alkaline phosphatase or with 6-methyladenine if purine bases were released from the mononucleotides by acid hydrolysis. In another experiment in which FeLV-R 28S RNA uniformly labeled with 32P was hydrolyzed and then analyzed by Pellionex-WAX chromatography, all of the 32P label again co-chromatographed with mononucleotides. Thus FeLV-R 28S RNA does not appear to contain a 5' structure, either methylated or nonmethylated similar to those recently reported for cellular and some animal virus mRNA's. | US |
The effect of ATP and its congeners on the adrenergic neuroeffector transmission was evaluated in isolated blood vessels of the rabbit. ATP, ADP, AMP and adenosine inhibited the contractile response of the portal vein to adrenergic nerve stimulation, with a threshold concentration of the order of 0.1 muM and ED50 of about 1 microM. These agents, but not papaverine, inhibited the nerve stimulation-induced response in preference to the norepinephrine- or serotonin-induced response in the portal and saphenous veins and pulmonary and ear arteries. In the portal vein labeled with [3H]norepinephrine, ATP diminished the nerve stimulation-induced efflux of tritiated material. This nucleotide also reduced the KCl-induced tritium efflux but not the tyramine induced-efflux in the [3H]norepinephrine-labeled thoracic aorta. ATP had no significant effect on the uptake of [3H]norepinephrine in the portal vein, ear artery and thoracic aorta. Indomethacin and theophylline partially blocked the inhibitory action of ATP on the neurogenic constrictor response in some of the ear artery and saphenous vein preparations. Desipramine, atropine, propanolol, haloperidol and 2,2'-pyridylisatogen, a blocking agent against ATP in the taenia coli, were without such antagonistic effect. The results are consistent with a proposed negative feedback modulator role of ATP or a related purine compound in adrenergic transmission. | US |
All, or nearly all, of the nonhepatic splanchnic viscera were removed in dogs. In most untreated dogs, the liver cells underwent changes similar to those caused by portacaval shunt, including structural deterioration of organelles and fatty metamorphosis. The rate of division of the hepatocytes, as measured by the mitotic index and by autoradiography, was depressed as were deoxyribonucleic acid synthesis and adenylate cyclase activity. These changes were restored to, or toward, normal with the intraportal administration of commercial or purified insulin but not with glucagon or epidermal growth factor. The results of both the pathologic and biochemical studies were consistent, except for an incongruity in some of the dogs in which the colon was retained. | US |
Surgical data derived from the 606 patients in the National Wilms' Tumor Study have been analyzed to determine the effect of surgical technique on results of treatment. In addition to surgical excision of the tumor, patients were treated with chemotherapy and radiation therapy according to the study protocol. Under these controlled conditions, certain aspects of surgical technique which have traditionally been thought to be important for success appear to be irrelevant. Physical characteristics of the tumor, preoperative rupture and vascular invasion by tumor were not associated with higher relapse rates. Large tumors, those with capsular infiltrations, and tumors with spread to lymph nodes higher recurrence rate. Operative spill increased the chance of abdominal recurrence. There was no evidence that early ligation of the renal vein was of value in prevention of recurrence, nor was incomplete removal of tumor associated with an increase in relapse rate. Although several critical factors of surgical technique were not studied, it is clear that others are not significant and need not be continued. | US |
A protein phosphatase activity has been demonstrated in nuclei of rat ventral prostate utilizing 32P-labelled phosvitin as a model acidic phosphoprotein substrate. This phosphoprotein phosphatase has a pH optimum of 6.7, is unaffected by the sulphydryl protecting agent 2-mercaptoethanol, and requires a divalent cation for maximal activity. Of the various divalent cations tested, Mg2+ is the most effective in reactivating the EDTA-inhibited enzyme. The phosphatase is inhibited by sodium flouride, sodium oxalate, N-ethylmaleimide, ATP and ADP but is relatively insensitive to ammonium molybdate. Increased ionic strength of the reaction medium also causes a reduction in the enzyme activity, e.g., by 48% at 200 mM sodium chloride. The activity of the acidic phosphoprotein phosphatase did not change significantly at 48 h or 96 h post-orchiectomy when expressed per unit of nuclear protein. However, it is reduced by approx. 30% at these times after castration if based on DNA content. The decline in activity per nucleus reflects the decrease in the realtive nuclear protein content observed at 48 h or 96 h post-orchiectomy. This suggests that the decline in the phosphorylation of prostatic nuclear acidic proteins which occurs upon androgen withdrawal is not due to increased nuclear phosphatase activity. | US |
The influence of portal blood factors on canine liver regeneration was studied with graded nonhepatic splanchnic evisceration, coupled with 44 and 72 per cent hepatectomies. In one type of experiment, the pancreas was retained while the rest of the intra-abdominal gastrointestinal tract was removed. In a second variety, total pancreatectomy was performed with preservation of the intra-abdominal organs. In a third kind of experiment, total nonhepatic splanchnic evisceration was performed. Liver regeneration after hepatectomy was decreased by all three kinds of viscera removed as judged by deoxyribonucleic acid synthesis, autoradiography and mitotic index. Pancreatectomy and nonpancreatic splanchnic evisceration caused almost equal decreases in the regenerative response. Total nonhepatic splanchnic evisceration essentially halted regeneration during the first three postoperative days and intraportal infusions of insulin or glucagon, or both together, did not reverse this effect. The decrease in liver membrane bound adenyl cyclase activity and biphasic change in liver cyclic 3', 5' -adenosine monophosphate concentrations normally seen after partial hepatectomy were disrupted after the various eviscerations. Adenyl cyclase activity and cyclic 3', 5' -adenosine monophosphate concentrations tended to be higher than normal in the eviscerated dogs. These observations provide more support for our previously proposed hypothesis that control of liver regeneration is by multiple factors. Pancreatic hormones are important modifiers of this response but, by no means, exercise exclusive control. Other substances of gastrointestinal origin, presumably including hormones and nutrient supply apparently play important specific roles. The volume of portal flow is a secondary and nonspecific, but possibly significant, factor. | US |
A girl with hereditary tyrosinemia, diagnosed at 6 months of age, was treated with a diet restricted in phenylalanine and tyrosine. At 9 1/2 years of age she developed an acutely enlarged liver and spleen, and the diagnosis of hepatocarcinoma was made. The patient received a liver transplant and tyrosine metabolites became normal while she was receiving a regular diet. Three months later, an infected thrombosis of the portal vein caused her death. Liver transplant appears to be an effective method of enzyme replacement in tyrosinemia and should be considered for prevention of hepatoma. | US |
Glucagon was tested for its effect on plasma adenosine 3',5'-cyclic monophosphate (cyclic AMP), insulin, and glucose in healthy subjects and in patients with advanced cirrhosis of the liver. In the normal subjects, intravenous infusion of glucagon caused a significant increase in plasma cyclic AMP, glucose, and insulin. In advanced cirrhotics, plasma cyclic AMP, glucose, and insulin did not increase. Adenylate cyclase concentration was measured in liver tissue from end stage cirrhotic patients and from brain-dead organ donors whose cardiovascular function was maintained in a stable state. Basal and total adenylate cyclase concentration were not different in the two groups. Adenylate cyclase from the livers of advanced cirrhotics was, however, significantly less responsive to glucagon stimulation than was that from donor livers. Hepatocytes in advanced cirrhosis have abnormal metabolic behavior characterized by abnormal adenylate cyclase-cyclic AMP response to hormonal stimulation. | US |
Between 1970 and 1978, eight hepatic adenomas were resected. Four of the eight patients took oral contraceptive pills before the hepatic adenoma was identified; one patient was male. Four patients had evidence of bleeding at the time of presentation. The original histologic diagnosis in the first five patients was malignant hepatoma. There has been no known recurrence of tumor and all patients are well. The use of oral contraceptives in these patients has been prohibited. Formal anatomic resection is recommended for hepatic adenoma when this procedure can be done without mortality or serious morbidity; however, in the future, less drastic treatments, such as occlusion of the hepatic arterial circulation to the tumor or discontinuation of oral contraceptives, may prove as effective as tumor resection. | US |
The mechanisms responsible for altered adrenergic tone in hyperthyroidism and hypothyroidism are not fully understood. To investigate these mechanisms, the beta-adrenergic receptor-cyclic AMP complex of the turkey erythrocyte was studied among groups of normal, hyperthyroid, and hypothyroid turkeys. In erythrocytes obtained from hypothyroid turkeys, there were fewer beta-adrenergic receptors than in normal cells as determined by the specific binding of [(125)I]iodohydroxybenzylpindolol, as well as associated decreases both in catecholamine-responsive adenylate cyclase activity and in cellular cyclic AMP content. In contrast, erythrocytes obtained from hyperthyroid turkeys contained the same number of beta-receptors and had the same catecholamine-responsive adenylate cyclase activity as cells from normal birds. Other characteristics of the beta-receptors in cells from hyperthyroid birds were indistinguishable from those present in normal erythrocytes. However, within the range of circulating catecholamine concentrations, 5-50 nM, the erythrocytes of the hyperthyroid turkeys generated substantially more cyclic AMP after exposure to isoproterenol than did normal cells. These results suggest that thyroid hormone affects beta-receptor-cyclic AMP interrelationships in the turkey erythrocyte by two distinct mechanisms: (a) In hypothyroidism, both beta-receptors and catecholamine-dependent cyclic AMP formation are coordinately decreased; (b) in hyperthyroidism, beta-receptors are unchanged but there is an amplification of the hormonal signal so that occupation of a given number of receptors at physiological concentrations of catecholamines leads to increased levels of cyclic AMP. | US |
Coinfection of monkey cells with simian virus 40 (SV40) and adenovirus type 2 (Ad2) increased the Ad2 yield 1,000-fold over that obtained by Ad2 infection alone of monkey cells (A. S. Rabson, G. T. O'Conor, I. K. Berezesky, and F. J. Paul, Proc. Soc. Exp. Biol. Med. 116:187-190, 1964). The ability of viable mutants of SV40 that contain deletions at various sites in the viral DNA to enhance Ad2 growth in monkey cells was examined. Only those mutants with deletions near the 3' end of the early region were deficient in providing this helper function. Mutants dl1265, lacking 39 base pairs at map position 0.18, and dl1263, lacking 33 base pairs at map position 0.20 (H. van Heuverswyn, C. Cole, P. Berg, and W. Fiers, J. Virol. 30:936-941, 1979), were approximately 4 and 30% as effective as wild-type SV40, respectively. The extent of enhancement of Ad2 yield depended on the multiplicity of infection by SV40, but not by Ad2 (at a multiplicity of infection of </=50), as well as on the relative times of infection by Ad2 and SV40. Increasing the SV40 multiplicity of infection or infecting cells with SV40 wild type or mutants prior to Ad2 infection increased the Ad2 yield dramatically. The T antigens of wild-type SV40, dl1263, and dl1265 were examined. We attempt to correlate defects in helper function, alterations in the T antigen structure, and the DNA sequence of the mutants as determined by van Heuverswyn et al. (J. Virol. 30:936-941, 1979). | US |
Fine wire microelectrodes were implanted for diagnostic purposes in 17 patients suffering from psychomotor epilepsy. Single- and multiunit activity during waking and natural nocturnal slow wave sleep and REM sleep was recorded in the hippocampus (n = 42), hippocampal gyrus (n = 53), and amygdala (n = 32). The firing rates of hippocampal gyrus units usually decreased during slow wave sleep and then increased to levels equal to or above waking during REM. In contrast, the firing rates of hippocampal neurons generally increased during slow wave sleep and fell to very low levels during REM. The amygdala presented a more mixed pattern. Since the projection from the hippocampal gyrus to hippocampus is excitatory, their opposite patterns during sleep suggest that the tonic firing patterns of HC neurons may be mainly the result of subcortical afferents. | US |
The effects of delta 9-tetrahydrocannabinol (THC) and ethidium bromide (EB) on the developmental life cycle and DNA metabolism of Volvox carteri have been investigated. THC, previously shown to interfere specifically with cytoplasmic DNA (cDNA) in this organism, was used at different concentrations and at different times during the life cycle. The morphological consequences observed were found to be dependent on the nature and time of treatment. This study also indicates that ethidium bromide induces degradatin of cDNA similar to that mediated by THC. However, unlike THC, it also causes the cessation of nuclear DNA synthesis. The consequences of EB treatment on morphological development are different from those observed with THC. A correlatin of these observations with the biochemical results presented suggests possible models in which the amounts and proportions of nuclear and cytoplasmic DNA play a role in the regulation of embryogenesis in this organism. | US |
The sleep electroencephalogram (EEG) was studied in 41 depressed inpatients. EEG sleep records were compared for two diagnostic subgroups; patients with psychotic depression (n = 29) or with schizoaffective disorders (n = 12). As was true in the previous pilot study, no major EEG sleep variables distinguished the patients with psychotic depression from those with schizoaffective disorders. These data are consistent with the theory that all psychotic depressive states may have certain common psychobiologic features such as shortened rapid eye movement (REM) sleep latency. | US |
The use of 'near miss for Sudden Infant Death syndrome' infants as a model toward understanding the Sudden Infant Death syndrome has been questioned. Although there are numerous problems in delineating this patient population and defining events occurring during sleep, continuous polygraphic monitoring demonstrates potentially life-threatening events. | US |
The mechanism of beta-adrenergic relaxation was investigated in isolated smooth muscle cells. Beta-adrenergic agents stimulate cyclic AMP-dependent phosphorylation, enhance Na+/K+ transport and induce relaxation. The stimulation of Na+/K+ transport is obligatory for relaxation, and we suggest that this stimulation induces relaxation through enhanced Na+/Ca2+ exchange. | US |
Schmidt-Ruppin strain of Rous Sarcoma was inoculated intracerebrally into 27 newborn beagle dogs. Fourteen days after viral inoculation, 13 of the dogs were given intravenous BCNU (1 mg/kg). The other 14 were given the same volume of intravenous saline in a randomized, double-blinded fashion. Ninety percent of all dogs developed intracranial tumors. Radionuclide (mercury 197) brain scans were done on each dog at 2-week intervals. Median survival was 113 days in the BCNU group and 115 days in the placebo group (P > .99). Unequivocally positive radionuclide brain scans were detected in 5 dogs treated with BCNU and in 2 of the controls. There were no gross or microscopic differences at autopsy between treated and nontreated animals. BCNU, as given in this animal brain tumor model, did not demonstrate any oncolytic effect. An improvement in sequential brain scans was detected in 2 other dogs in response to Dexamethasone, which was given in a double-blinded, cross-over controlled fashion. Computerized tomography clearly demonstrated the tumor in two cases. | US |
Serum lipoproteins were measured by ultracentrifugal means in rats bearing hepatomas of different degrees of malignancy (Morris hepatomas 16, 5123TC and 7777) to determine the effect of these hepatomas on serum lipoprotein levels. Serum lipoprotein patterns were altered, especially in rats bearing hepatomas 16 and 7777, which had elevated high-density lipoproteins. (They were not elevated in serum of rats bearing hepatoma 5123TC). This increase in high-density lipoproteins seems to be specific for chemically induced hepatomas since HDL2 is usually decreased in humans and animals with types of cancer not involving the liver. It appears that hepatomas can synthesize lipoproteins, and the serum levels of the host rats are altered depending on the hepatoma. Different biochemistries appear to be associated with each hepatoma. Cholesterol and fatty acid levels of unfractionated serum and of isolated lipoproteins also indicate abnormal lipid/lipoprotein metabolism associated with these hepatomas. | US |
Heart rates of 5 rhesus monkeys (Macaca mulatta) were monitored during classical conditioning trials consisting of a visual conditioned stimulus followed after 10 sec by an electric shock to the tail. Heart rates typically increased at the onset of the visual stimulus, and returned to baseline before shock delivery. Autonomic blocking agents were subsequently administered; their effects on resting heart rates, and on acceleratory and deceleratory phases of the biphasic conditioned heart rate responses were examined, both in the raw data, and with a statistical regression technique. Beta-adrenergic blockade by propranolol lowered resting heart rates and was found, after regression analysis, to reduce the heart rate increase phase, and to weakly enhance the subsequent heart rate decrease phase of the conditioned response. Vagal blockade by atropine sulfate elevated resting heart rate, and markedly reduced both acceleratory and deceleratory heart rate phases of the conditioned responses. Ganglionic blockade by chlorisondamine also elevated resting heart rates (less than atropine), and almost completely eliminated conditioned heart rate changes. Several sources of evidence suggest a predominant vagal tone over resting heart rates, as well as mostly vagal mediation (with some sympathetic contribution) of the biphasic conditioned rate response. | US |
This report describes detailed protocols for the dissociation, seeding and growth in vitro of monolayer cultures derived from neonatal rat cerebrum. Primary cultures derived by using different seeding densities and in vitro ages were examined qualitatively and quantitatively for morphological composition in terms of two major cell classes (flat cells and process-bearing cells) and for the presence within these classes of glial fibrillary acidic protein (GFA) as detected by immunofluorescence histochemistry. Also examined was the reaction of the cells to serum withdrawal plus the administration of dibutyryl cyclic AMP in terms of the conversion of flat cells into process-bearing cells. Conditions are defined for the generation of in vitro cell populations, more than 90% of which are GFA-containing flat cells which can all be experimentally converted into cells with processes. These well-defined culture preparations will serve as useful models for future studies of astroglial behaviour. | US |
Epidemiological data presented here indicate that cytomegaloviral (CMV) infection is one of the most common perinatal infections found in human beings. Transmission to the offspring occurs in utero at birth and postnatally. Intrauterine infection results from primary or recurrent maternal involvement, the latter being more common in populations where infection is initially acquired during childhood or adolescence, such as in low socioeconomic settings. Congenital infection is usually subclinical with either type of maternal involvement but primary infection has a greater tendency to produce disease in the fetus. About 20% of the offspring infected in utero are damaged, infrequently with generalized disease, but more often with auditory involvement. The latter can develop in utero or postnatally and can be progressive. The major cause of recurrent maternal infection according to restriction enzyme analysis is reactivation of latent virus, which occurs in the face of substantial maternal humoral immunity, even with intrauterine transmission of virus. Reinfection by exogenous virus remains a lesser possibility for maternal recurrences. Even more commonly, CMV can be transmitted at birth from the infected maternal genital tract and postnatally through infected breast milk, especially in highly immune populations. With the possible exception of early pneumonia, these infections appear to be innocuous. | US |
Transplants of rat hippocampus into the anterior chamber of the eye of a host animal were used to assess the effects of cholinergic and adrenergic neuronal inputs on the generation and duration of seizure activity. Cholinomimetics initiated both seizures and hypersynchronous neuronal activity in the transplants. Cyclic guanosine monophosphate (GMP) derivatives and isobutyl methylxanthine elicited similar changes. Reflex activation of the cholinergic parasympathetic input to the iris and transplant by illumination of the ipsilateral retina also induced seizures or increased the rate of penicillin-induced interictal spike discharge. Application of beta-adrenergic agonists inhibited interictal spikes and paroxysmal depolarizing shifts induced by penicillin. Fluorescence histochemical studies showed that host sympathetic adrenergic fibers derived from the ground plexus of the iris invaded the transplant to form fine varicose nerve terminals. Activation of these adrenergic afferents to the transplant diminished both the amplitude and frequency of penicillin-induced epileptiform activity. Epileptiform activity in hippocampal occular transplants is strongly modulated by cholinergic and adrenergic neuronal inputs, with the former exerting a facilatory influence and the latter, an inhibitory effect. | US |
Convulsant doses of pentylenetetrazol (100 mg/kg) increase levels of both cyclic adenosine monophosphate (AMP) and cyclic guanosine monophosphate (GMP in mouse cerebral cortex and hippocampus. In animals pretreated with reserpine, propranolol, or aminophylline, pentylenetetrazol seizures were more severe, cyclic AMP elevations were attenuated or blocked, and cyclic GMP increases were unaffected or augmented. These data indicate that norepinephrine, adenosine, and perhaps other biogenic amines have a regulatory effect on cyclic AMP, but not cyclic GMP, levels in epileptic brain. An increased level of cyclic AMP in brain tissue may have an antiepileptic effect leading to seizure attenuation or termination. By contrast, elevated levels of cyclic GMP may have an epileptogenic effect in initiating or maintaining seizure activity. | US |
Isolated rat liver mitochondria were labeled in vitro with L-[14C]leucine. Sixty percent of the incorporated radioactivity was found to reside in subunits 1, 2, and 3 of cytochrome c oxidase with apparent molecular weights of approximately 33,000, 25,000, and 20,000, respectively. The results indicate that these are the predominant products of protein synthesis under the conditions employed. The enzyme complex, as derived by immunoprecipitation, was found to contain four additional polypeptides with apparent molecular weights of 17,000, 12,500, 7000, and 3500. A comparison of electrophoretic profiles of the rat liver and beef heart enzyme reveals that the apparent molecular weights of all polypeptides are remarkably similar. | US |
Changes in the conformation of Complex III (CoQH2-cytochrome c reductase) of the mitochondrial respiratory chain were detected upon oxidoreduction using the nitroxide spin label, 3-(maleimidomethyl)-2,2,5,5-tetramethyl-1-pyrrolidinyloxyl. EPR spectra of the spin label show a transition from a greater to a lesser degree of immobilization when the labeled enzyme, reduced either with ascorbate or sodium dithionite, is oxidized with potassium ferricyanide or ferricytochrome c. These observations are interpreted to indicate that Complex III is more compact in the reduced state at least in the locality of the spin label. An apparent increase in the concentration of total spins during oxidation of the complex suggests change in the interaction between the spin label and other paramagnetic centers and not an oxidation of spin label, itself, since reduced free spin label could not be reoxidized. Addition of antimycin A had no effect on the EPR spectrum of the spin-labeled enzyme, indicating that this inhibitor does not initiate a conformational change in the region of the spin label. Experiments in which N-ethyl-[2-3H] maleimide was bound to Complex III show that binding occurs primarily to a subunit with a molecular weight of 45,000. Although no qualitative differences were observed, it was found that less radioactivity appears in samples reduced with dithionite than in those reduced with ascorbate. This difference appears to be caused by decomposition products of dithionite. | US |
Independent immunoenzymatic and radioimmunoassay techniques indicated the absence of tolyl-specific IgG antibodies in sera from 25 workers with long-term exposure to toluene diisocyanate (TDI). Five of these workers were clinically hypersensitive to TDI and displayed significant titers of tolyl-specific IgE antibodies in their sera. | US |
An in vitro model system was developed to study the effects that immune cells might have on herpes simplex virus (HSV) infection of rat dorsal root ganglia in culture. Our results demonstrate that rat splenic lymphocytes and peritoneal exudate cells are incapable of replicating HSV even if these cells come from sensitized animals and are stimulated in vitro. Both cell preparations can offer some protection to rat dorsal root ganglia from the effects of HSV infection. The data suggest that an immunologically non-specific (not mediated by sensitized cells) type of protection is important to neurons, while an immunologically specific (mediated by sensitized cells) protection is most beneficial to fibroblasts. This system can be utilized to study the mechanism of latency since the neurons of sensory ganglia are the natural site of latent herpes virus. | US |
A combination of K+/DC surface electrode and a fiberoptic fluorometric probe are applied to measurements in brain during cerebral ischemia. The kinetics of the responses of extracellular K+ activity and intracellular NADH fluorescence in the gerbil cerebrum following reversible carotid ligation are measured. K+e shows a two-phase response to carotid occlusion and an extended recovery phase following recirculation. The length of the recovery phase is dependent on the duration and severity of the ischemic period. In the gerbil model the degree of communication in the anterior circulation is variable, whereas a bilateral carotid occlusion is presumed to give complete cerebral ischemia. Pyridine nucleotide fluorescence serves as an indicator of the degree of ischemia. Bilateral carotid occlusions of up to 35 minutes in duration were performed. K+e reaches 30--50 mEq/liter in the extracellular space within the first two minutes. This represents cell depolarization and equilibration of K+ activity levels. Recovery appears to be complete in terms of the ability of the system to clear raised levels of K+e from the extracellular space. | US |
Oral metaproterenol was administered daily for 3 months to asthmatic children. The study was designed to determine whether chronic tolerance developed to this drug. Initial and final crossovers on the first 2 and the last 2 days of the investigation to a test dose of metaproterenol and placebo failed to show tolerance as indicated by improvement in lung volumes and dynamic mechanics of breathing after metaproterenol. Forced expiratory volume in 1 sec was the test most consistent in demonstrating bronchodilation; the action of metaproterenol. Forced expiratory volume in 1 sec was the test most consistent in demonstrating bronchodilation; the action of metaproterenol appeared to last at least 5 hours as measured by this test. T of distribution of ventilation, e.g., single- and multiple-breath nitrogen washout tests, were not consistently altered by metaproterenol. These tests did not appear to be sufficiently sensitive to detect improvement even when airway resistance decreased and forced expiratory volume in 1 sec increased toward the normal range. | US |
Administration of three successive doses of triiodothyronine (T3) (50 micrograms/100 g body wt), given on alternate days to thyroidectomized and euthyroid rats, stimulated oxygen consumption (QO2) and Na+ transport-dependent respiration (QO2 [5]) in the stripped jejunal mucosa, a preparation that consisted mostly of epithelial cells. The increase in QO2(t) accounted for 57% of the increment in QO2 in the transition from the hypothyroid to the euthyroid state and for 29% of the increment in the transition from the euthyroid to the hyperthyroid state. Administration of T3 to hypothyroid rats also increased the yield of epithelial cells. Injection of T3 into thyroidectomized and euthyroid rats increased the specific activity (at Vmax) of the (Na+ + K+)-dependent adenosine triphosphatase (NaK-ATPase) in jejunal crude membrane preparations. No significant change was recorded in the activity of Mg-ATPase in the same preparation. The ratio of QO2/NaK-ATPase and QO2(t)/NaK-ATPase in the various thyroid states remained constant, indicating proportionate increased in the respiratory and enzymatic indices. The effect of administration of T3 to thyroidectomized rats on the number of NaK-ATPase units (recovered in the crude membrane preparation) was estimated by: (a) Na+ + Mg++ + ATP-dependent binding of [3H]-ouabain to crude membrane fractions, and (b) the amount of the phosphorylated intermediate formed in the NaK-ATPase reaction from AT32P(gamma). Estimates were obtained of the maximal number of [3H]ouabain binding sites (Nm) and dissociation constants (Kd). Nm for [3H]ouabain and Nak-ATPase specific activity increased to about the same extent after T3 administration to thyroidectomized rats, with no change in the apparent Kd values. The amount of phosphorylated intermediate formed in jejunal crude membrane preparations also increased significantly. Thus, thyroid hormone administration may increase the number of active Na+pump sites in the plasma membrane. The apparent increase in the number of Na+ pump sites also correlated with the hormone dependent increases in QO2 and QO2(t). | US |
A voltage clamp technique was used to study sodium currents and gating currents in squid axons internally perfused with the membrane impermeant sodium channel blocker, QX-314. Block by QX-314 is strongly and reversibly enhanced if a train of depolarizing pulses precedes the measurement. The depolarization-induced block is antagonized by external sodium. This antagonism provides evidence that the blocking site for the drug lies inside the channel. Depolarization-induced block of sodium current by QX-314 is accompanied by nearly twofold reduction in gating charge movement. This reduction does not add to a depolarization-induced immobilization of gating charge normally present and believed to be associated with inactivation of sodium channels. Failure to act additively suggests that both, inactivation and QX-314, affect the same component of gating charge movement. Judged from gating current measurement, a drug-blocked channel is an inactivated channel. In the presence of external tetrodotoxin and internal QX-314, gating charge movement is always half its normal size regardless of conditioning, as it QX-314 is then permanently present in the channel. | US |
Quaternary strychnine blocks sodium channels from the axoplasmic side, probably by insertion into the inner channel mouth. Block is strongly voltage dependent, being more pronounced in depolarized than in resting axons. Using potential steps as a means to modulate the level of block, we investigate strychnine effects on sodium and gating currents at +50 and -50 mV. We analyze our data in terms of the simplest possible model, wherein only an open channel may receive and retain a strychnine molecule. Our main findings are (a) block by strychnine and inactivation resemble each other and (b) block of sodium and gating currents by strychnine happen with closely similar time-courses. Our data support the hypothesis of Armstrong and Bezanilla (1977) wherein an endogenous blocking particle causes inactivation by inserting itself into the inner mouth of the sodium channel. Quaternary strychnine may act as an artificial substitute for the hypothetical endogenous blocking particle. Further, we suggest that at least 90% of the rapid asymmetrical displacement current in squid axons is sodium channel gating current, inasmuch as quaternary strychnine can block 90% of the displacement current simultaneously with sodium current. | US |
In X-band electron paramagnetic resonance spectra from single crystals of horse ferric hemoglobin, observed line widths at the low- and high-field extrema are 30 and 24 g, and as much as 400 G in the intermediate region. This behavior is similar to that of ferric myoglobin. Due to large anisotropy in the g-tensors, the line width variation can be accounted for on the basis of heme orientation disorder. This disorder is characterized by an angle, determined here by two independent methods. In these computations Gaussian disorder on a sphere is assumed. The disorder angle is found to be constant on the sphere and about 4 degrees for both alpha- and beta- chains. Treatment of crystals with heavy water (buffer) increases the disorder. Since ligand nitrogen hyperfine couplings are available from hemoglobin electron nuclear double resonance, single crystal electron paramagnetic resonance spectra can be simulated by superimposing hyperfine bands, where the line width of the component bands is a variable and the disorder model above is employed. Comparison with observed resonances fixes the hyperfine component line widths. These component line widths from ferric hemoglobin in the crystalline state are found to be smaller than those in frozen solution. | US |
The contributions to the dipolar broadening of ferric magnetic resonances, from crystals of hemoglobin for which the atomic coordinates are known, have been calculated. The total second moment of the g = 2 resonance so determined is about 50 (MHz)2 or 5.0 G (peak-to-trough), figures consistent with the range of values found from analysis of experimental data. Two-thirds of this second moment comes from the two protons of the H2O molecule coordinated to the iron. Treatment with D2O is predicted to reduce the total second moment at g = 2 to about 25 (MHz)2, whereas the experimental measurements on single crystals show no decrease. If the structure of the tetramer is assumed to be the same when in solution as in the crystal, the total second moment is readily redetermined for hemoglobin in solution; the value so obtained is found to be significantly smaller than that from analysis of the g = 2 resonance measured in frozen solution. These two unexpected observations can be explained in terms of distributions in spin Hamiltonian parameters, the spread depending upon the nature of the sample--crystal or solution, ordinary or heavy water-treated. This distribution in H2O and D2O solutions appears to be about the same, since the measured differences in component line width agree with the calculated difference in dipolar contributions. | US |
The interaction of CrADP, an exchange-inert paramagnetic analogue of Mg-ADP, with yeast hexokinase has been studied by measuring the effects of CrADP on the longitudinal nuclear relaxation rate (1/T1) of the protons of water and the protons and phosphorus atom of enzyme-bound glucose-6-P. The paramagnetic effect of CrADP on 1/T1 of water protons is enhanced upon complexation with the enzyme. Titrations measuring this paramagnetic effect at several enzyme concentrations in the presence of glucose-6-P yielded a characteristic enhancement factor for 1/T1 of water protons and the dissociation constant of CrADP from the ternary enzyme . ADPCr . glucose-6-P complex. The latter value (2 mM) is similar to that obtained from kinetic inhibition studies (Danenberg and Cleland [1975]. Biochemistry. 14:28). The presence of glucose-6-P increased the enhancement of the water relaxation rate by enzyme-bound CrADP, suggesting the formation of an enzyme . CrADP . glucose-6-P complex. The existence of such a complex was confirmed by the observation of a paramagnetic effect of enzyme-bound CrADP on the l/T1 of the 31P-nucleus and protons of enzyme-bound glucose-6-P. From the paramagnetic effects of enzyme-bound CrADP on the relaxation rates of the 31P-nucleus and the carbon-bound protons of glucose-6-P in the enzyme . ADPCr . glucose-6-P complex, using the correlation time of approximately 0.7 ns, determined from the magnetic field-dependence of 1/T1 of water protons over the range 24.3-360 MHz, a Cr3+ to phosphorus distance of 6.6 +/- 0.7 A and Cr3+ to alpha- and beta-anomeric proton distances of 8.9 and 9.7 A were calculated. These results imply the absence of a direct coordination of the phosphoryl group of glucose-6-P by the nucleotide-bound metal on hexokinase but indicate van der Waals contact between a phosphoryl oxygen of glucose-6-P and the hydration sphere of the nucleotide-bound metal. The distances are consistent with a model that assumes molecular contact between the phosphorus of glucose-6-P and a beta-phosphoryl oxygen of ADP suggesting an associative phosphoryl transfer. Because after phosphorylation of ADP, the metal ion is coordinated to the transferred phosphoryl group, the overall migration of the phosphoryl group during the phosphoryl transfer is approximately 3.6 A toward the nucleotide-bound metal. Little or no catalysis of phosphoryl transfer from glucose-6-P to alpha, beta-bidentate or beta-monodentate CrADP ( less than or equal to 0.05% of the rate found with MgADP) occurred in the presence of hexokinase, as monitored by glucose formation in a coupled assay system using glucose oxidase and peroxidase. The ability of beta, gamma-bidentate CrATP to act as a substrate (Danenberg and Cleland [1975]. | US |
In dialyzed Myxicola axons substitution of heavy water (D2O) externally and internally slows both sodium and potassium kinetics and decreases the maximum conductances. Furthermore, this effect is strongly temperature dependent, the magnitude of the slowing produced by D2O substitution decreasing with increasing temperature over the range 3-14 degrees C with a Q10 of approximately 0.71. The relatively small magnitude of the D2O effect, combined with its strong temperature dependence, suggests that the rate limiting process producing a conducting channel involves appreciable local changes in solvent structure. Maximum conductances in the presence of D2O were decreased by approximately 30%, while the voltage dependences of both gNa and gK were not appreciably changed. In contrast to the effects of heavy water substitution on the ionic currents, membrane asymmetry currents were not altered by D2O, suggesting that gating charge movement may preceed by several steps the final transformation of the Na+ channel to a conducting state. In Myxicola axons the effect of temperature alone on asymmetry current kinetics can be well described via a simple temporal expansion equivalent to a Q10 of 2.2, which is somewhat less than the Q10 of GNa activation. The integral of membrane asymmetry current, representing maximum charge movement, is however not appreciably altered by temperature. | US |
Hyperpolarizing conditioning pulses delay the onset of potassium channel current in voltage-clamped myelinated nerve fibers. Both the development of and recovery from this conditioning are approximately exponential functions of time: the time constants are functions of the conditioning voltage. The delay is larger and develops faster for more hyperpolarized conditioning pulses. The magnitude of the delay (but not the rate of development or recovery) depends upon the test potential-small test depolarizations produce larger delays than large depolarizations. The currents with and without the conditioning pulse cannot be made to superimpose by a simple time translation. | US |
We have compared the stimulatory activity of DBcAMP with various antiproliferative agents on the induction of the humoral immune response. When they are present only during an early stage of immune induction, DBcAMP, colcemid, cytosine-arabinoside, hydroxy urea, and high specific activity 3H-thymidine can all enhance the primary 19s antibody response to SRBC. In contrast, each of these agents inhibits the PFC response, when they are incubated with the cells during late stages of induction of humoral immunity. Because all of these agents can inhibit proliferation of cultured cells, the results suggested that DBcAMP and other agents that elevate cAMP could augment humoral immunity via their effects on cellular proliferation. However, we also found that although each agent could modulate induction of the immune response to SRBC, only DBcAMP produced a dose- and time-dependent augmentation of the response to DLF. We conclude that although antiproliferative effects of drugs may contribute to augmentation of some humoral antibody responses, this effect alone is insufficient to account for the mechanism by which agents that elevate intracellular levels of cAMP produce enhancement of humoral immunity. | US |
Thymosin fraction 5 and a more purified acidic fraction of thymosin at a 100-fold lower concentration elevated cGMP levels, but not cAMP levels, in murine thymocytes. When both thymus and spleen lymphocytes were fractionated via a BSA gradient procedure, both cAMP and cGMP basal values varied depending on the density of the subpopulations. Thymosin Fr5 did not elevate cAMP in any thymus subpopulation of lymphocytes obtained from the BSA density gradients. The cGMP elevation due to thymosin Fr5 in thymocytes was maximal in the most buoyant thymocytes, and no elevation of cGMP was detected in nude mouse spleen lymphocytes. These results suggest that the cGMP elevation may be an early event in the thymosin-mediated differentiation of a more mature subpopulation of thymocytes. They also suggest that utilization of subpopulations may be necessary for the complete determination of the effects of agents on cyclic nucleotide values of lymphocytes. | US |