bluuebunny/crossref_metadata_2025 huggingface dataset:
Reversal of Induced Ischemic Neurologic Deficit in Gerbils by the Opiate Antagonist Naloxone
Authors: Hosobuchi Yoshio , Baskin David S. , Woo Sidney K.
Published: October 2006

Microsurgical unilateral occlusion of the right common carotid artery in 140 adult male gerbils produced homolateral cerebral ischemia and a neurologic deficit (stroke) in 42 percent (group A); the other 58 percent did not develop signs of stroke (group B). Intraperitoneal injection of the opiate antagonist naloxone (1 milligram per kilogram of body weight) reversed the signs of stroke within 3 to 5 minutes in ten out of ten group A gerbils; the effect lasted up to 30 minutes, after which stroke returned. Repeated injections of naloxone reversed stroke, but all ten gerbils died within 48 hours of ligation. However, nine other group A gerbils implanted with 10-milligram naloxone pellets had continuous reversal of signs of stroke, and four survived for more than 2 weeks. Twenty-one out of 24 group B gerbils injected intraperitoneally with morphine sulfate (5 to 30 milligrams per kilogram) 9 hours after ligation developed stroke within 3 to 20 minutes; morphineinduced stroke lasted 4 to 24 hours and could be reversed by intraperitoneal injection of naloxone. Ten out of 11 other group B gerbils injected intraperitoneally with the stereoisomeric opiate agonist levorphanol 9 hours after ligation developed signs of mild stroke that were reversed by intraperitoneal injection of naloxone. Ten other group B gerbils injected intraperitoneally with dextrorphan, the inactive enantiomer of levorphanol, 9 hours after ligation did not develop signs of stroke. Intraperitoneal injection of an enkephalin analog (Sandoz FK33824; 15 milligrams per kilogram) 9 hours after ligation did not produce stroke in ten other group B gerbils. These findings suggest the involvement of endorphins and opiate receptors in the pathophysiology of stroke and suggest the possible clinical use of opiate antagonists in humans in the acute phase of stroke.
Experimental Hepatic Encephalopathy: Changes in the Binding of γ-Aminobutyric Acid
Authors: Baraldi Mario , Zeneroli Maria L.
Published: October 2006

Two populations of receptors for γ-aminobutyric acid, one with low- and the other with high-affinity characteristics, are detectable in frozen, thawed, Triton-treated synaptic membrane preparations from normal brain. It is now reported that membrane preparations from rats with mild galactosamine-induced hepatic encephalopathy show an increase in the number of low- and high-affinity γ-aminobutyric acid binding sites, whereas those from rats with severe encephalopathy show only high-affinity binding sites. Thus, hepatic encephalopathy appears to involve partial degeneration of the γ-aminobutyric acid-containing presynaptic nerve terminals.
Calmodulin Binds to Chick Lens Gap Junction Protein in a Calcium-Independent Manner
Authors: Welsh Michael J. , Aster Jon C. , Ireland Mark , Alcala Jose , Maisel Harry
Published: October 2006

A biochemically active conjugate of calmodulin and tetramethylrhodamine isothiocyanate (CaM-RITC) was synthesized. When incubated with sections of chick lens, this conjugate bound to the surface membranes of lens fiber cells in the presence of absence of calcium. Incubation of lens sections with antibodies to gap junction protein of lens completely blocked the binding of the conjugate to cell membranes, whereas serum from nonimmunized animals or antibodies to other lens proteins reduced the binding only slightly. By means of a gel overlay procedure,
125
I-labeled calmodulin was found to bind to the gap junction protein of lens, also in a calcium-independent manner. These results support the concept that calmodulin may interact with and regulate gap junctions in living cells.
Cytomegalovirus Antibody in Cerebrospinal Fluid of Schizophrenic Patients Detected by Enzyme Immunoassay
Authors: Torrey E. Fuller , Yolken Robert H. , Winfrey C. Jack
Published: October 2006

By means of enzyme immunoassay techniques to detect the presence of antibody to cytomegalovirus, the cerebrospinal fluid of 178 patients with schizophrenia, 17 patients with bipolar disorders, and 11 other psychiatric patients was compared with that of 79 neurological patients and 41 normal control subjects. The cerebrospinal fluid of 20 of the schizophrenic patients and 3 of the patients with bipolar disorders showed significant increases in immunoglobulin M antibody to cytomegalovirus; no difference was found in patients on or off psychotropic medications.
Regulation of Circadian Rhythmicity
Authors: Takahashi Joseph S. , Zatz Martin
Published: October 2006

Daily rhythms in many behavioral, physiological, and biochemical functions are generated by endogenous oscillators that function as internal 24-hour clocks. Under natural conditions, these oscillators are synchronized to the daily environmental cycle of light and darkness. Recent advances in locating circadian pacemakers in the brain and in establishing model systems promise to shed light on the cellular and biochemical mechanisms involved in the generation and regulation of circadian rhythms.
An Ultrastructural Correlate of the Membrane Mutant "Paranoiac" in
Paramecium
Authors: Byrne Barbara J. , Byrne Bruce C.
Published: October 2006

The highly organized array of intramembranous particles, the ciliary plaque, varies from the wild type in size and organization in two stocks of the
Paramecium
behavioral mutant, paranoiac. In one of these stocks, the alteration is dramatic.
Increased Resistance to
Staphylococcus aureus
Infection and Enhancement in Serum Lysozyme Activity by Glucan
Authors: Kokoshis P. L. , Williams D. L. , Cook J. A. , Di Luzio N. R.
Published: October 2006

Glucan is a potent reticuloendothelial stimulant whose immunobiological activity is mediated, in part, by an increase in the number and function of macrophages. In studying the role of glucan as a mediator of antibacterial activity, we attempted to ascertain the ability of glucan to modify the mortality of mice with experimentally induced Gram-positive bacteremia, and to enhance antibacterial defenses in rats as denoted by serum lysozyme and phagocytic activity. After intravenous administration of glucan, serum lysozyme concentrations were increased approximately sevenfold over control concentrations. The increase in serum lysozyme appeared to parallel the glucan-induced increase in phagocytosis and induced hyperplasia of macrophages. Prior treatment of mice with glucan significantly enhanced their survival when they were challenged systemically with Staphylococcus aureus. These studies indicate that glucan confers an enhanced state of host defense against bacterial infections.
Frequency Discrimination Following the Selective Destruction of Cochlear Inner and Outer Hair Cells
Authors: Nienhuys Terry G. W. , Clark Graeme M.
Published: October 2006

Frequency discrimination was measured behaviorally before and after drug-induced lesions of cochlear hair cells in the cat. Discrimination was unaffected by complete loss of outer hair cells provided that at least 50 percent of inner hair cells were intact. Thus, inner hair cells are important for frequency discrimination, and they can function normally in this regard without the influence of outer hair cells.
Evidence for the Neuropeptide Cholecystokinin as an Antagonist of Opiate Analgesia
Authors: Faris Patricia L. , Komisaruk Barry R. , Watkins Linda R. , Mayer David J.
Published: October 2006

The endogenous neuropeptide cholecystokinin, when administered systemically or perispinally, potently antagonizes opiate analgesia produced by foot shock and morphine. Nonopiate foot-shock analgesia is not reduced by this neuropeptide. The spinal cord appears to be a critical site of cholecystokinin action. These experiments suggest a physiological role for cholecystokinin as a specific opiate antagonist in analgesia-mediating systems. A similar mode of action may explain other behavioral effects of cholecystokinin, such as suppression of food intake.
Associative Conditioning of Single Sensory Neurons Suggests a Cellular Mechanism for Learning
Authors: Walters Edgar T. , Byrne John H.
Published: October 2006

A cellular analog of associative learning has been demonstrated in individual sensory neurons of the tail withdrawal reflex of
Aplysia
. Sensory cells activated by intracellular current injection shortly before a sensitizing shock to the animal's tail display significantly more facilitation of their monosynaptic connections to a tail motor neuron than cells trained either with intracellular stimulation unpaired to tail shock or with tail shock alone. This associative effect is acquired rapidly and is expressed as a temporally specific amplification of heterosynaptic facilitation. The results suggest that activity-dependent neuromodulation may be a mechanism underlying associative information storage and point to aspects of subcellular processes that might be involved in the formation of neural associations.
Sodium Currents in Segments of Human Heart Cells
Authors: Bustamante J. Omar , McDonald Terence F.
Published: October 2006

Isolated human heart cells were partially drawn into the lumen of a plastic tube and cleaved at the partitioning tube wall by intraluminal suction pulses. The extraluminal segment (10 to 20 percent of the cell length) was suitable for intracellular perfusion and voltage clamp. The time and voltage dependence of the sodium current, and the responses to changes in driving force and channel blockers, illustrate the potential of these preparations as models for the study of membrane channels.
Suppression of the Humoral Antibody Response in Natural Retrovirus Infections
Authors: Trainin Ze'ev , Wernicke Dorothee , Ungar-Waron Hannah , Essex Max
Published: October 2006

The feline leukemia virus (FeLV) frequently causes death by predisposing the host to acute infections by other pathogens rather than by inducing leukemia. In a previous study, cats infected with FeLV were found to have prolonged homograft rejection responses but there was no evidence that the humoral immune response was impaired. In the present study, the humoral response to the synthetic multichain polypeptide (L-tyrosine-L-glutamic acid)-poly-DL-alanine-poly-L-lysine, denoted (T,G)AL, was found to be significantly depressed in healthy cats that were naturally infected with FeLV compared to uninfected controls. In cats with persistent FeLV viremia the major antibody response to (T,G)AL, normally seen at days 9 to 14 after immunization, was both delayed and greatly reduced.
Amiloride Directly Inhibits the Na,K-ATPase Activity of Rabbit Kidney Proximal Tubules
Authors: Soltoff Stephen P. , Mandel Lazaro J.
Published: October 2006

Amiloride inhibited the ouabain-sensitive rate of oxygen consumption (
Q
O
2
) of a suspension of rabbit intact proximal tubules in the presence of different concentrations of extracellular sodium. Measurements of the ouabain-sensitive
Q
O
2
in the presence of nystatin, the tissue sodium and potassium contents of the tubules in suspension, and the sodium- and potassium-dependent adenosinetriphosphatase (Na,K-ATPase) activity of lysed tubule membranes indicated that the effect of amiloride was due to a direct inhibition of the Na,K-ATPase activity of the proximal tubule.
Nitrite Inhibition of
Clostridium botulinum
: Electron Spin Resonance Detection of Iron-Nitric Oxide Complexes
Authors: Reddy D. , Lancaster J. R. , Cornforth D. P.
Published: October 2006

Vegetative cells of
Clostridium botulinum
were shown to contain iron-sulfur proteins that react with added nitrite to form iron-nitric oxide complexes, with resultant destruction of the iron-sulfur cluster. Inactivation of iron-sulfur enzymes (especially ferredoxin) by binding of nitric oxide would almost certainly inhibit growth, and thus is probably the mechanism of botulinal inhibition by nitrite in foods.
Ivermectin: A Potent New Antiparasitic Agent
Authors: Campbell W. C. , Fisher M. H. , Stapley E. O. , Albers-Schönberg G. , Jacob T. A.
Published: October 2006

Ivermectin is the 22,23-dihydro derivative of avermectin B
1
, a macrocyclic lactone produced by an actinomycete,
Streptomyces avermitilis
. It is active at extremely low dosage against a wide variety of nematode and arthropod parasites, apparently by virtue of its action on the mediation of neurotransmission by γ-aminobutyric acid. It is now in commercial use in various countries for the treatment and control of parasites in cattle, horses, and sheep, and is expected to become available for use in swine and dogs. Since studies with the drug in man are in a preliminary stage, it is not yet known whether ivermectin will be useful in human medicine.
Strain Differences in Rat Brain Epinephrine Synthesis: Regulation of α-Adrenergic Receptor Number by Epinephrine
Authors: Perry Bruce D. , Stolk Jon M. , Vantini Guido , Guchhait Ras B. , U'Prichard David C.
Published: October 2006

Inbred rat strains Fischer 344 (F344) and Buffalo (BUF) differ in several physiological and behavioral measures. It was found that the activity of adrenomedullary and regional brain phenylethanolamine
N
-methyltransferase is at least four times higher in F344 rats than in BUF rats; these strain-dependent differences corresponded directly with the epinephrine content of the medulla-pons and hypothalamus. Conversely, α-adrenergic receptor density in brain regions containing phenylethanolamine
N
-methyltransferase is two to three times lower in F344 rats than in BUF rats; α-receptors in frontal cortex (a brain region lacking phenylethanolamine
N
-methyltransferase activity and epinephrine) are similar in both strains. These findings suggest that strain-dependent differences in α-receptors are regulated by inherited differences in presynaptic adrenergic neuronal function in different brain regions.
Phorbol Ester Receptors: Autoradiographic Identification in the Developing Rat
Authors: Murphy K. M. M. , Gould R. J. , Oster-Granite M. L. , Gearhart J. D. , Snyder Solomon H.
Published: October 2006

Autoradiography with
3
H-labeled phorbol dibutyrate was used for the light microscopic detection of phorbol ester receptors in rat fetuses. In 15- and 18-day fetuses, as well as in adult rats, receptors were found to be concentrated in the central nervous system. The localization of receptors in the ventral marginal zone of the fetal neural tube, the lens of the eye, and other sites suggests a role for phorbol ester receptors in cellular process extension and cell-cell interaction.
Nicotine is Chemotactic for Neutrophils and Enhances Neutrophil Responsiveness to Chemotactic Peptides
Authors: Totti Noel , McCusker Kevin T. , Campbell Edward J. , Griffin Gail L. , Senior Robert M.
Published: October 2006

Neutrophils contribute to chronic bronchitis and pulmonary emphysema associated with cigarette smoking. Nicotine was found to be chemotactic for human neutrophils but not monocytes, with a peak activity at ∼ 31 micromolar. In lower concentrations (comparable to those in smokers' plasma), nicotine enhanced the response of neutrophils to two chemotactic peptides. In contrast to most other chemoattractants for neutrophils, however, nicotine did not affect degranulation or superoxide production. Nicotine thus may promote inflammation and consequent lung injury in smokers.
Androgen Modulation of Adrenal Angiotensin Receptors
Authors: Carroll John E. , Goodfriend Theodore L.
Published: October 2006

Several polar androgens increased the binding of angiotensin and its stimulation of aldosteronogenesis in bovine adrenal glomerulosa cells. The effect was seen only if the steroids were applied to the cells and then washed away. This phenomenon and the technique for demonstrating it may have implications for studies of receptor modulation and for clinical states in which responsiveness to angiotensin is increased.
Elevated Concentrations of CSF Corticotropin-Releasing Factor-Like Immunoreactivity in Depressed Patients
Authors: Nemeroff Charles B. , Widerlöv Erik , Bissette Garth , Walléus Helena , Karlsson Ingvar , Eklund Kurt , Kilts Clinton D. , Loosen Peter T. , Vale Wylie
Published: October 2006

The possibility that hypersecretion of corticotropin-releasing factor (CRF) contributes to the hyperactivity of the hypothalamo-pituitary-adrenal axis observed in patients with major depression was investigated by measuring the concentration of this peptide in cerebrospinal fluid of normal healthy volunteers and in drug-free patients with DSM-III diagnoses of major depression, schizophrenia, or dementia. When compared to the controls and the other diagnostic groups, the patients with major depression showed significantly increased cerebrospinal fluid concentrations of CRF-like immunoreactivity; in 11 of the 23 depressed patients this immunoreactivity was greater than the highest value in the normal controls. These findings are concordant with the hypothesis that CRF hypersecretion is, at least in part, responsible for the hyperactivity of the hypothalamo-pituitary-adrenal axis characteristic of major depression.
Deficiency of a Kidney Metalloproteinase Activity in Inbred Mouse Strains
Authors: Beynon Robert J. , Bond Judith S.
Published: October 2006

Kidneys from BALB/c mice contain a potent metalloendoproteinase, termed meprin, that is active against large proteins as well as small peptides. The enzyme is present in mouse strains C57BR/cdJ, C57BL/6J, BALB/cJ, A/J, DBA/1J, CD/1, Swiss, and ICR. Three related inbred strains, CBA/J, CBA/CaJ, and C3H/He, are markedly deficient in this enzymatic activity. This is the first report of a heritable deficiency of an intracellular proteinase in mammalian tissues. Meprin deficiency appears to have arisen as an early event in the development of the C stock. Furthermore, meprin is present in the progeny of a cross between a meprin-sufficient female (C57BL/6) and a meprin-deficient male (C3H/HeN), an indication that the trait for the deficiency is recessive.
Antibodies to Cell Membrane Antigens Associated with Human T-Cell Leukemia Virus in Patients with AIDS
Authors: Essex M. , McLane M. F. , Lee T. H. , Falk L. , Howe C. W. S. , Mullins J. I. , Cabradilla C. , Francis D. P.
Published: October 2006

The acquired immune deficiency syndrome (AIDS), which has recently occurred at increasing rates in homosexual men, intravenous drug users, and others, is characterized by the development of Kaposi's sarcoma and several opportunistic infections including pneumonia caused by
Pneumocystis carinii
. Serum samples from patients with AIDS and from matched and unmatched control subjects were examined for the presence of antibodies to cell membrane antigens associated with human T-cell leukemia virus. Nineteen of 75 of the AIDS patients had antibodies directed to surface antigens of Hut 102, a reference T lymphoid cell line infected with the leukemia virus, as did two of the 336 control subjects.
Transcription of Class III Genes: Formation of Preinitiation Complexes
Authors: Lassar Andrew B. , Martin Paul L. , Roeder Robert G.
Published: October 2006

Class III genes require multiple cellular factors for transcription by RNA polymerase III; these genes form stable transcription complexes, which in the case of
Xenopus
5
S
genes are correlated with differential expression in vivo. The minimal number and identity of the factors required to form both stable and metastable complexes on three class III genes (encoding, respectively, 5
S
RNA, transfer RNA, and adenovirus VA RNA species) were determined. Stable complex formation requires one common factor, whose recognition site was analyzed, and either no additional factors (the VA gene), a second common factor (the transfer RNA gene), or a third gene-specific factor (the 5
S
gene). The mechanism of stable complex formation and its relevance to transcriptional regulation were examined in light of the various factors and the promoter sequences recognized by these factors.
Yeast RNA Polymerase II Genes: Isolation with Antibody Probes
Authors: Young Richard A. , Davis Ronald W.
Published: October 2006

Genes encoding yeast RNA polymerase II subunits were cloned. Efficient isolation of these genes was accomplished by probing a phage λgt11 recombinant DNA expression library with polyvalent antibodies directed against purified yeast RNA polymerase II. The identity of genes that specify the largest RNA polymerase II subunits, the 220,000- and 150,000-dalton polypeptides, was confirmed by competitive radioimmune assay. Both of these genes exist in single copy in the yeast
Saccharomyces cerevisiae
.
Directed Mutagenesis of Dihydrofolate Reductase
Authors: Villafranca Jesus E. , Howell Elizabeth E. , Voet Donald H. , Strobel Majorie S. , Ogden Richard C. , Abelson John N. , Kraut Joseph
Published: October 2006

Three mutations of the enzyme dihydrofolate reductase were constructed by oligonucleotide-directed mutagenesis of the cloned
Escherichia coli
gene. The mutations—at residue 27, aspartic acid replaced with asparagine; at residue 39, proline replaced with cysteine; and at residue 95, glycine replaced with alanine—were designed to answer questions about the relations between molecular structure and function that were raised by the x-ray crystal structures. Properties of the mutant proteins show that Asp-27 is important for catalysis and that perturbation of the local structure at a conserved
cis
peptide bond following Gly-95 abolishes activity. Substitution of cysteine for proline at residue 39 results in the appearance of new forms of the enzyme that correspond to various oxidation states of the cysteine. One of these forms probably represents a species cross-linked by an intrachain disulfide bridge between the cysteine at position 85 and the new cysteine at position 39.
Insulin Antibodies in Insulin-Dependent Diabetics Before Insulin Treatment
Authors: Palmer Jerry P. , Asplin Christopher M. , Clemons Peter , Lyen Kenneth , Tatpati Olga , Raghu Prima K. , Paquette Thomas L.
Published: October 2006

A sensitive assay was used to measure the binding of iodine-125-labeled insulin in serum obtained from 112 newly diagnosed insulin-dependent diabetics before insulin treatment was initiated. Two groups of nondiabetics served as controls: children with a variety of diseases other than diabetes and nondiabetic siblings of insulin-dependent diabetics. Eighteen of the diabetics were found to have elevated binding and 36 were above the 95th percentile of control values. The insulin-binding protein is precipitated by antibody to human immunoglobulin G, has a displacement curve that is parallel and over the same concentration range as serum from long-standing insulin-dependent diabetics, and elutes from a Sephacryl S-300 column at the position of gamma globulin. These insulin antibodies are present in a large percentage of newly diagnosed, untreated diabetics and may be an immune marker of B-cell damage.
Expression of a Retrovirus Encoding Human HPRT in Mice
Authors: Miller A. Dusty , Eckner Robert J. , Jolly Douglas J. , Friedmann Theodore , Verma Inder M.
Published: October 2006

Transmissible retroviruses encoding human hypoxanthine phosphoribosyltransferase (HPRT) were used to infect mouse bone marrow cells in vitro, and the infected cells were transplanted into mice. Both active human HPRT-protein and chronic HPRT-virus production were detected in hematopoietic tissue of the mice, showing transfer of the gene. These results indicate the possible use of retroviruses for somatic cell therapy.
Animal-to-Man Transmission of Antimicrobial-Resistant
Salmonella
: Investigations of U.S. Outbreaks, 1971-1983
Authors: Holmberg Scott D. , Wells Joy G. , Cohen Mitchell L.
Published: October 2006

The importance and origin of antimicrobial-resistant
Salmonella
infections were examined in 52 outbreaks investigated by the Centers for Disease Control between 1971 and 1983. The case fatality rate was higher for patients infected with antimicrobial-resistant
Salmonella
(4.2 percent) than for those with antimicrobial-sensitive infections (0.2 percent). In the 38 outbreaks with identified sources, food animals were the source of 11 (69 percent) of 16 resistant and 6 (46 percent) of 13 sensitive outbreak strains.
Heparin Binds Endothelial Cell Growth Factor, the Principal Endothelial Cell Mitogen in Bovine Brain
Authors: Maciag Thomas , Mehlman Tevie , Friesel Robert , Schreiber Alain B.
Published: October 2006

Endothelial cell growth factor (ECGF), an anionic polypeptide mitogen, binds to immobilized heparin. The interaction between the acidic polypeptide and the anionic carbohydrate suggests a mechanism that is independent of ion exchange. Monoclonal antibodies to purified bovine ECGF inhibited the biological activity of ECGF in crude preparations of bovine brain. These data indicate that ECGF is the principal mitogen for endothelial cells from bovine brain, that heparin affinity chromatography may be used to purify and concentrate ECGF, and that the affinity of ECGF for heparin may have structural and perhaps biological significance.
High-Performance Liquid Chromatography-Mass Spectrometry
Authors: Vestal Marvin L.
Published: October 2006

Techniques for on-line coupling of high-performance liquid chromatography with mass spectrometry are reviewed with particular emphasis on those suitable for application to nonvolatile samples. The present status of various techniques is summarized and the strengths and weaknesses of the various approaches are assessed. The potential for future application of recently developed techniques for combined liquid chromatography and mass spectrometry is discussed.
Inhibitors of Poly(Adenosine Diphosphate-Ribose) Synthesis: Effect on Other Metabolic Processes
Authors: Milam Kathryn M. , Cleaver James E.
Published: October 2006

3-Aminobenzamide and benzamide, purported to be specific inhibitors of the synthesis of poly(adenosine diphosphate-ribose), were used to elucidate possible functions of this biopolymer. These compounds, at frequently used experimental concentrations, not only inhibited the action of poly(adenosine diphosphate-ribose) synthetase but also affected cell viability, glucose metabolism, and DNA synthesis. Thus, the usefulness of 3-aminobenzamide and benzamide may be severely restricted by the difficulty of finding a dose small enough to inhibit the synthetase without producing additional metabolic effects.
Intestinal Uptake and Metabolism of Auranofin, a New Oral Gold-Based Antiarthritis Drug
Authors: Tepperman Katherine , Finer Richard , Donovan Stuart , Elder R. C. , Doi J. , Ratliff David , Ng Kin
Published: October 2006

Auranofin, 2,3,4,6-tetra-
O
-acetyl-1-thio-β-D-glucopyranosato-
S
-(triethylphosphine)- gold(I), an experimental antiarthritis pharmaceutical, metabolized in contact with hamster or rat gut wall to yield the deacetylated form of the drug. This product, 1-thio-β-D-glucopyranosato-
S
-(triethylphosphine)gold(I), passed through hamster or rat intestinal wall in an everted gut experiment. The metabolite was separated by high-performance liquid chromatography and characterized by retention time, chemical reactivity to yield a known product, and comparison to a synthetic sample of the metabolite.
Homologies Between Signal Transducing G Proteins and
ras
Gene Products
Authors: Hurley James B. , Simon Melvin I. , Teplow David B. , Robishaw Janet D. , Gilman Alfred G.
Published: October 2006

The guanosine triphosphate-binding proteins (G proteins) found in a variety of tissues transduce signals generated by ligand binding to cell surface receptors into changes in intracellular metabolism. Amino acid sequences of peptides prepared by partial proteolysis of the α subunit of a bovine brain G protein and the α subunit of rod outer-segment transducin were determined. The two proteins show regions of sequence identity as well as regions of diversity. A portion of the amino-terminal peptide sequence of each protein is highly homologous with the corresponding region in the
ras
protein (a protooncogene product). These similarities suggest that G proteins and
ras
proteins may have analogous functions.
Bursting Neural Networks: A Reexamination
Authors: Russell David F. , Hartline Daniel K.
Published: October 2006

Many of the motor neurons in the lobster (
Panulirus interruptus
) stomatogastric ganglion exhibit plateau potentials; that is, prolonged regenerative depolarizations resulting from active membrane properties, that drive the neurons to fire impulses during bursts. Plateaus are latent in isolated ganglia but are unmasked by central input. These findings emphasize the role of cellular properties as compared to synaptic wiring in the production of cyclic motor patterns by ensembles of neurons.
Norepinephrine in Chronic Paranoid Schizophrenia: Above-Normal Levels in Limbic Forebrain
Authors: Farley Irene J. , Price Kathleen S. , McCullough Edward , Deck John H. N. , Hordynski Walter , Hornykiewicz Oleh
Published: October 2006

In postmortem examination of brains of four patients with chronic paranoid schizophrenia, above-normal norepinephrine levels were measured in the ventral septum, the bed nucleus of the stria terminalis, the nucleus accumbens, and the mammillary bodies. No changes were detected in other limbic forebrain regions, including the hypothalamus and the medial olfactory (preoptic) area. The results point to the possibility of a malfunction of limbic noradrenergic mechanisms in schizophrenia, especially the paranoid variety.
Delayed Hypersensitivity in Man: Effects of Systemic Anticoagulation
Authors: Edwards Richard L. , Rickles Frederick R.
Published: October 2006

Skin test reactivity, lymphocyte transformation, and mononuclear cell tissue factor generation were evaluated both before and during systemic anticoagulation in 24 volunteers. Anticoagulation with warfarin decreased skin test induration and tissue factor generation, but lymphocyte transformation remained unchanged. An intact coagulation mechanism, including tissue factor generation, appears to be important for the development of skin test induration in humans.
A Neural Map of Auditory Space in the Owl
Authors: Knudsen Eric I. , Konishi Masakazu
Published: October 2006

Auditory units that responded to sound only when it originated from a limited area of space were found in the lateral and anterior portions of the midbrain auditory nucleus of the owl (
Tyto alba
). The areas of space to which these units responded (their receptive fields) were largely independent of the nature and intensity of the sound stimulus. The units were arranged systematically within the midbrain auditory nucleus according to the relative locations of their receptive fields, thus creating a physiological map of auditory space.
Transport of Energy in Muscle: The Phosphorylcreatine Shuttle
Authors: Bessman Samuel P. , Geiger Paul J.
Published: October 2006

In order to explain the insulin-like effect of exercise, it was proposed in 1951 that contracting muscle fibers liberate creatine, which acts to produce an acceptor effect—later called respiratory control—on the muscle mitochondria. The development of this notion paralleled the controversy between biochemists and physiologists over the delivery of energy for muscle contraction. With the demonstration of functional compartmentation of creatine kinase on the mitochondrion, it became clear that the actual form of energy transport in the muscle fiber is phosphorylcreatine. The finding of an isoenzyme of creatine phosphokinase attached to the M-line region of the myofibril revealed the peripheral receptor for the mitochondrially generated phosphorylcreatine. This established a molecular basis for a phosphorylcreatine-creatine shuttle for energy transport in heart and skeletal muscle and provided an explanation for the inability to demonstrate experimentally a direct relation between muscle activity and the concentrations of adenosine triphosphate and adenosine diphosphate.
Concentration Oscillations and Efficiency: Glycolysis
Authors: Richter Peter H. , Ross John
Published: October 2006

The oscillations observed in glycolysis are analyzed from the point of view of efficiency of free energy conversion. It is suggested that the mechanisms generating these oscillations may have evolved in order to reduce the dissipation of free energy.
Autoantibodies to Nucleosomal Proteins: Antibodies to HMG-17 in Autoimmune Diseases
Authors: Bustin Michael , Reisch Joanne , Einck Leo , Klippel John H.
Published: October 2006

The relative amounts of autoantibodies against defined nucleosomal proteins present in serums from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and mixed connective tissue disease (MCTD) have been examined by an enzyme-linked immunoassay. Autoantibodies to nucleosomal proteins were detected in 45 percent of the patients with SLE, 18 percent of the MCTD patients, and none of the RA patients. The results suggest that, in SLE, antibodies are formed against a subset of nucleosomes which contain protein HMG-17.
Neuroleptic-Induced Decrease in Plasma Homovanillic Acid and Antipsychotic Activity in Schizophrenic Patients
Authors: Pickar David , Labarca Rodrigo , Linnoila Markku , Roy Alec , Hommer Daniel , Everett Donald , Paul Steven M.
Published: October 2006

Plasma-free homovanillic acid, a major metabolite of dopamine, was measured in chronically ill schizophrenic patients both before and during treatment with the antipsychotic phenothiazine, fluphenazine. Neuroleptic treatment was associated with a significant time-dependent decrease in plasma homovanillic acid from pretreatment values, which were significantly elevated when compared with those of age- and sex-matched healthy control subjects. Further, both the absolute concentrations as well as the neuroleptic-induced reductions in plasma homovanillic acid determined over 5 weeks of neuroleptic treatment were statistically significantly correlated with ratings of psychosis and improvement in psychosis, respectively. These findings suggest that the delayed effects of neuroleptic agents on presynaptic dopamine activity may more closely parallel their therapeutic actions than do their immediate effects in blocking postsynaptic dopamine receptors and that a decrease in dopamine "turnover" may be responsible for their antipsychotic effects.
Neurons Generated in the Adult Brain Are Recruited into Functional Circuits
Authors: Paton John A. , Nottebohm Fernando N.
Published: October 2006

Adult canaries,
Serinus canarius
, received injections of
3
H-labeled thymidine, a marker of DNA synthesis. Thirty days after the last injection, intracellular potentials were recorded from neurons in the nucleus hyperstriatum ventralis pars caudalis, a vocal control nucleus in the telencephalon; these same cells were then injected with horseradish peroxidase. Of the 74 neurons labeled with horseradish peroxidase that were recovered, the nuclei of seven were radioactively labeled. Four of these seven neurons had responded to auditory stimuli. These double-labeled neurons were apparently generated during or after the
3
H-labeled thymidine treatment (during adulthood) and subsequently incorporated into functional neural circuits.
Ratio of Serum Urea to Serum Creatinine in Wild Black Bears
Authors: Nelson Ralph A. , Beck Thomas D. I. , Steiger Dianne L.
Published: October 2006

In winter, the ratio of serum urea to serum creatinine is 10 or less in denning female and male bears. In midsummer it is 22 or more, similar to that of other mammals. However, in late summer and early fall, while food is available, the urea-to-creatinine ratio approaches or becomes 10 or less. The low value of this ratio appears to indicate the biochemical state of hibernation, and many bears are in this state weeks before they den.
Amino Acid Sequence Similarity Between Rabies Virus Glycoprotein and Snake Venom Curaremimetic Neurotoxins
Authors: Lentz Thomas L. , Wilson Paul T. , Hawrot Edward , Speicher David W.
Published: October 2006

Evidence was presented earlier that a host-cell receptor for the highly neurotropic rabies virus might be the acetylcholine receptor. The amino acid sequence of the glycoprotein of rabies virus was compared by computer analysis with that of snake venom curaremimetic neurotoxins, potent ligands of the acetylcholine receptor. A statistically significant sequence relation was found between a segment of the rabies glycoprotein and the entire sequence of long neurotoxins. The greatest identity occurs with residues considered most important in neurotoxicity, including those interacting with the acetylcholine binding site of the acetylcholine receptor. Because of the similarity between the glycoprotein and the receptor-binding region of the neurotoxins, this region of the viral glycoprotein may function as a recognition site for the acetylcholine receptor. Direct binding of the rabies virus glycoprotein to the acetylcholine receptor could contribute to the neurotropism of this virus.
Albumin Phylogeny for Clawed Frogs (
Xenopus
)
Authors: Bisbee Chester A. , Baker Margaret A. , Wilson A. C. , Haji-Azimi Irandokht , Fischberg Michail
Published: October 2006

Comparisons of albumin indicate that the frogs commonly used by North American molecular and developmental biologists under the name of
Xenopus muelleri
belong to another species,
X. borealis
. Phylogenetic analysis of the albumin data reveals two major groups of
Xenopus
species, one containing only
X. tropicalis
and the other, called the
X. laevis
group, containing the remaining species of the genus. The phylogenetic tree, in conjunction with evidence from chromosomes and DNA content, leads to the hypothesis that total genome duplication occurred in the common ancestor of the
X. laevis
group.
Activated Expression of the N-
myc
Gene in Human Neuroblastomas and Related Tumors
Authors: Kohl Nancy E. , Gee Connie E. , Alt Frederick W.
Published: October 2006

In neuroblastoma lines in which the N-
myc
gene is present as a single copy, the expression of N-
myc
as messenger RNA is increased relative to that in nonneuroblastoma cell lines and tumors. The increase of expression in neuroblastomas with amplified N-
myc
genes is the result of (i) an increase in the absolute amount of expression of each N-
myc
gene and (ii) an increase in the copy number of the N-
myc
gene. A second gene—which is amplified in many of the same lines as N-
myc
—is expressed to about the same degree in most human cell lines and primary tumors regardless of origin (when normalized to gene copy number). Thus, a change in the regulation of N-
myc
expression in neuroblastomas and certain other tumors results in greatly increased expression of each N-
myc
gene copy.
Inhibition of Gastric Acid Secretion in the Gastric Brooding Frog,
Rheobatrachus silus
Authors: Tyler Michael J. , Shearman David J. C. , Franco Rony , O'Brien Paul , Seamark R. F. , Kelly R.
Published: October 2006

The female gastric brooding frog
Rheobatrachus silus
broods its young in its stomach. A substance that inhibits gastric acid secretion in a toad stomach preparation in vitro appears to be secreted by the developing young. This substance has been identified as prostaglandin E
2
.
Rheobatrachus silus
may thus have developed a mechanism whereby prostaglandin secreted by the larvae inhibits acid secretion in the stomach of the female until the larvae have completed development and emerged as juvenile frogs by way of the female's mouth.
Discrete Visual Defects in Pearl Mutant Mice
Authors: Balkema Grant W. , Mangini Nancy J. , Pinto Lawrence H.
Published: October 2006

The mutant mouse pearl, characterized by its hypopigmentation, has a specific functional defect in a sensory system—the retina. The intact pearl mouse has reduced sensitivity in the dark-adapted condition. Normal sensitivity is restored by isolation and superfusion of the retina with bicarbonate-buffered Ringer solution, suggesting that the retinal expression of the pearl mutation depends on a diffusible substance. The pearl phenotype is described as a possible model for human congenital stationary night blindness.
Behavioral Disease in Rats Caused by Immunopathological Responses to Persistent Borna Virus in the Brain
Authors: Narayan O. , Herzog S. , Frese K. , Scheefers H. , Rott R.
Published: October 2006

Borna virus replicated persistently in the brains of rats, causing frenzied and apathetic behavioral states in sequence but no mortality. The transient frenzied behavior was caused by an immune-mediated, cytolytic, encephalitic response that was unexpectedly self-limiting. Cessation of active pathological processes coincided with the onset of the passive phase of the disease. This study thus demonstrates suppression of virus-specific inflammation despite continuous viral replication and describes a new mechanism by which chronic encephalitis may become established.
Angiotensinogen Is Related to the Antitrypsin-Antithrombin-Ovalbumin Family
Authors: Doolittle Russell F.
Published: October 2006

The recently reported amino acid sequence of rat angiotensinogen was subjected to a computer-assisted search for homology with known sequences stored in a data bank and found to be significantly related to that of plasma α
1
-antitrypsin, itself a member of a family that includes antithrombin III and ovalbumin. An alignment of the four sequences shows indisputably the common ancestry of all four proteins.
Monoclonal Antibodies in the Lymphatics: Selective Delivery to Lymph Node Metastases of a Solid Tumor
Authors: Weinstein John N. , Steller Michael A. , Keenan Andrew M. , Covell David G. , Key Marc E. , Sieber Susan M. , Oldham Robert K. , Hwang Kou M. , Parker Robert J.
Published: October 2006

After subcutaneous injection, monoclonal antibodies directed against a tumor can enter local lymphatic vessels, pass to the draining lymph nodes, and bind to metastases there. Lymphatic delivery of antibody to early metastases is more efficient than intravenous administration, and the lymphatic route can be used to image smaller metastatic deposits. Perhaps more important, the lymphatic route minimizes binding of antibodies to circulating tumor antigens and to cross-reactive antigens present on normal tissues. Antibodies inappropriate for intravenous use because of binding to normal tissues may therefore be useful against lymph node metastases when injected subcutaneously or directly into lymphatic vessels.
A Micromechanical Contribution to Cochlear Tuning and Tonotopic Organization
Authors: Holton Thomas , Hudspeth A. J.
Published: October 2006

The response properties of hair cells and nerve fibers in the alligator lizard cochlea are frequency selective and tonotopically organized with longitudinal position in the organ. The lengths of the hair-cell hair bundles also vary monotonically with longitudinal position. In this study, quantitative measurements were made of the motion of individual hair bundles in an excised preparation of the cochlea stimulated at auditory frequencies. The angular displacement of hair bundles is frequency selective and tonotopically organized, demonstrating the existence of a micromechanical tuning mechanism.
Neuronal Generation of the Leech Swimming Movement
Authors: Stent Gunther S. , Kristan William B. , Friesen W. Otto , Ort Carol A. , Poon Margaret , Calabrese Ronald L.
Published: October 2006

The swimming movement of the leech is produced by an ensemble of bilaterally symmetric, rhythmically active pairs of motor neurons present in each segmental ganglion of the ventral nerve cord. These motor neurons innervate the longitudinal muscles in dorsal or ventral sectors of the segmental body wall. Their duty cycles are phase-locked in a manner such that the dorsal and ventral body wall sectors of any given segment undergo an antiphasic contractile rhythm and that the contractile rhythms of different segments form a rostrocaudal phase progression. This activity rhythm is imposed on the motor neurons by a central swim oscillator, of which four bilaterally symmetric pairs of interneurons present in each segmental ganglion appear to constitute the major component. These interneurons are linked intra- and intersegmentally via inhibitory connections to form a segmentally iterated and intersegmentally concatenated cyclic neuronal network. The network appears to owe its oscillatory activity pattern to the mechanism of recurrent cyclic inhibition.
Enhancement of Conditioned Arterial Pressure Responses in Cats After Brainstem Lesions
Authors: Nathan Marc A. , Tucker Lewis W. , Serverini Walter H. , Reis Donald J.
Published: October 2006

Cats were classically conditioned after the baroreceptor reflexes were abolished by bilateral placement of electrolytic lesions in the nucleus tractus solitarii. The conditioned increases in arterial pressure were more than five times larger than the responses obtained in similarly trained controls. This finding suggests that the baroreceptor reflexes actively inhibit conditioned increases of arterial pressure.
Anxiety Change Through Electroencephalographic Alpha Feedback Seen Only in High Anxiety Subjects
Authors: Hardt James V. , Kamiya Joe
Published: October 2006

Subjects who were either high or low in trait anxiety used alpha feedback to increase and to decrease their electroencephalographic alpha activity. The alpha changes were tightly linked to anxiety changes, but only in high anxiety subjects (for whom anxiety was reduced in proportion to alpha increases, and was increased in proportion to alpha suppression). Low trait-anxiety subjects were superior at both enhancement and suppression training, but their alpha changes were not related to anxiety changes. In both groups, anxiety changes were generally unrelated to either resting levels or changes in frontalis electromyograms and respiration rate. These results suggest that long-term alpha feedback training (at least 5 hours) may be useful in anxiety therapy.
Serologically Defined (SD) Locus in Cattle
Authors: Amorena Beatriz , Stone W. H.
Published: October 2006

Using cytotoxic serums obtained from multiparous cows or by alloimmunization, we have detected 11 lymphocyte antigens controlled by codominant alleles at a serologically defined locus called
BoLA-A
(bovine lymphocyte antigens). This locus, along with the lymphocyte defined loci previously reported, establishes the existence of a major histocompatibility system of cattle.
Central Nervous System Dysfunction Due to Lead Exposure
Authors: Valciukas José A. , Lilis Ruth , Fischbein Alf , Selikoff I. J. , Eisinger Josef , Blumberg William E.
Published: October 2006

Central nervous system dysfunction was investigated in workers at a secondary lead smelter by means of performance tests. Correlations between test scores and zinc protoporphyrin levels, a biological indicator of lead toxicity, are statistically significant. This correlation should prove to be useful in current efforts to evaluate effects of lead exposure.
X-Ray—Induced Breakage and Rejoining of Human Interphase Chromosomes
Authors: Cornforth Michael N. , Bedford Joel S.
Published: October 2006

A method was developed for the high-resolution measurement of breaks in prematurely condensed chromosomes at the G
1
phase of the cell cycle. The dose response for fragments (breaks) produced immediately after x-irradiation of confluent cultures of normal human cells was linear down to 10.9 rad (0.109 Gy) and extrapolated to zero effect at zero dose. The curve had a slope of 0.063 breaks per cell per rad, which is at least an order of magnitude greater than that for breaks scored in the same cells after they have progressed to mitosis following subculture. When incubated at 37°C half of the breaks disappeared in 2 hours. A slower, perhaps nonrejoining component was apparent at later incubation times. The initial rate of break rejoining was similar to the rate of increase in survival after incubation because of the repair of potentially lethal damage and is also in close agreement with recently reported values for the rejoining of double-strand breakage in DNA.