bluuebunny/crossref_metadata_2025 huggingface dataset:
Gestational Zinc Deprivation in Mice: Persistence of Immunodeficiency for Three Generations
Authors: Beach Richard S. , Gershwin M. Eric , Hurley Lucille S.
Published: October 2006

Pregnant Swiss Webster mice were fed a diet moderately deficient in zinc from day 7 of gestation until parturition. Offspring of these mice showed depressed immune function through 6 months of age. In addition, the second and third filial generations, all of which were fed only the normal control diet, continued to manifest reduced immunocompetence, although not to the same degree as in the first generation.
Coronary Vascular Reactivity After Acute Myocardial Ischemia
Authors: Ku David D.
Published: October 2006

Exogenous thrombin produced a biphasic response (a potent dose-related vasodilatation followed by vasoconstriction) in nonischemic canine coronary arteries. The vasodilatation was not blocked by propranolol, atropine, or indomethacin, but was completely blocked by heparin or denudation of the intimal endothelial cells. A similar loss of vasodilating response to thrombin occurred in ischemic coronary arteries with a concomitant enhancement of vasoconstriction. This study indicates that altered responses to thrombin in coronary arteries with damaged endothelium may play an important role in the pathogenesis of coronary vasospasm.
The Red Cell as a Fluid Droplet: Tank Tread-Like Motion of the Human Erythrocyte Membrane in Shear Flow
Authors: Fischer Thomas M. , Stöhr-Liesen Marianne , Schmid-Schönbein Holger
Published: October 2006

When whole human blood is subjected to viscometric flow, individual red cells are seen to be elongated and oriented in the shear field. In addition, a tank tread-like motion of the membrane around the cell content occurs. In dilute suspensions of erythrocytes in viscous media, the same behavior is better observed and can also be measured quantitatively.
Subsynaptic Plate Perforations: Changes with Age and Experience in the Rat
Authors: Greenough William T. , West Roger W. , DeVoogd Timothy J.
Published: October 2006

The relative frequency of appearance of discontinuities in the postsynaptic thickening, or perforations in the subsynaptic plate, increased with age and experience. Rats reared from weaning in complex or social environments had a significantly higher proportion of occipital cortical synapses with perforations than did rats reared in isolation. In addition, the relative frequency of these perforations more than tripled between 10 and 60 days of age. Shifts in the frequency of perforations can occur independently of changes in the size of synpases. This result suggests a new potential mechanism of synaptic plasticity.
Maternal Stress Alters Plasma Testosterone in Fetal Males
Authors: Ward Ingeborg L. , Weisz Judith
Published: October 2006

Titers of testosterone in plasma were determined by radioimmunoassay in male rat fetuses of stressed and control mothers on days 17, 18, 19, 21, and 23 (the day of birth) after conception. In fetuses of stressed mothers, testosterone concentrations were highest on day 17, declined on days 18 and 19, and then remained unchanged. In the control fetuses, testosterone increased from relatively low concentrations on day 17 to the highest amounts on days 18 and 19, and then declined. Thus, the persistence of feminine and impaired masculine sexual behavior in male offspring of stressed mothers could be due to the absence of a surge of circulating testosterone during days 18 and 19 after conception, a period postulated to be critical in the development of the central nervous system in the rat.
Gonadal Steroids: Effects on Excitability of Hippocampal Pyramidal Cells
Authors: Teyler Timothy J. , Vardaris Richard M. , Lewis Deborah , Rawitch Allen B.
Published: October 2006

Electrophysiological field potentials from hippocampal slices of rat brain show sex-linked differences in response to 1 × 10
-10
M
concentrations of estradiol and testosterone added to the incubation medium. Slices from male rats show increased excitability to estradiol and not to testosterone. Slices from female rats are not affected by estradiol, but slices from female rats in diestrus show increased excitability in response to testosterone whereas slices from females in proestrus show decreased excitability.
Superovulation and Embryo Transfer in Cattle
Authors: Seidel George E.
Published: October 2006

About 17,000 bovine pregnancies were produced by superovulation and embryo transfer in North America in 1979. The major use of these techniques is to increase the reproductive rate of valuable cows. Other applications include circumventing infertility, exporting embryos, and testing potential carriers for Mendelian recessive alleles. Cryopreservation of embryos is beginning to be used commercially, and sexing embryos before transfer may soon become routine.
Plasminogen Activator Release at the Neuronal Growth Cone
Authors: Krystosek Alphonse , Seeds Nicholas W.
Published: October 2006

The site of plasminogen activator release by differentiated neuroblastoma clonal cell lines was determined with a fibrin overlay assay. Release of plasminogen activator was seen at the growth cone in 72 percent of the cells bearing neurites. For 21 percent of these cells the growth cone was the predominant or exclusive site of this enzyme activity. Selective release of protease at the "trailblazing" tip of the neurite may be important in neuron migration and neurite growth in vivo.
Malignant Potential of Murine Stromal Cells After Transplantation of Human Tumors into Nude Mice
Authors: Goldenberg David M. , Pavia Rose A.
Published: October 2006

Human malignant cancer tumors grafted into nude mice produce tumors containing both human cancer cells and the host's stromal cells. After short-term propagation of these tumors in vitro, the murine mesenchymal cells appear transformed and are tumorigenic in nude mice. However, established human cancer cell lines fail to similarly alter adjacent murine stromal cells when used to produce tumors in nude mice. These experiments suggest that cancer cells may recruit normal cells to become malignant, qualifying the view of the clonal (unicellular) origin of cancer.
Carbamoyl Phosphate Synthetase (Glutamine-Hydrolyzing): Increased Activity in Cancer Cells
Authors: Aoki Takashi , Weber George
Published: October 2006

The specific activity of carbamoyl phosphate synthetase (glutamine-hydrolyzing), the first and rate-limiting enzyme of de novo uridine 5′-triphosphate biosynthesis, was increased in 13 transplantable hepatomas, particularly in the rapidly growing tumors (5.7- to 9.5-fold), and the rise was correlated with tumor growth rates. Thus, synthetase activity was linked with both hepatic neoplastic transformation and progression. Synthetase specific activity was also elevated in a transplantable sarcoma (18-fold) and a kidney adenocarcinoma (5-fold). The increased activity should enhance the capacity of the pathway and should confer selective advantages to cancer cells.
Drug Discrimination Learning in Lead-Exposed Rats
Authors: Zenick Harold , Goldsmith Marshall
Published: October 2006

Lead acetate (0.02 or 0.5 percent) was administered to dams throughout the lactation period with half of the litters continuing on lead after weaning. Drug thresholds for
d
-amphetamine were determined by using the drug-discrimination learning paradigm. All the offspring that had been exposed to lead were less sensitive to the stimulus properties of
d
-amphetamine irrespective of whether or not they had continued on lead after weaning.
Chitin: New Facets of Research
Authors: Austin P. R. , Brine C. J. , Castle J. E. , Zikakis J. P.
Published: October 2006

Research on chitin as a marine resource is pointing to novel applications for this cellulose-like biopolymer. Discovery of nondegrading solvent systems has permitted the spinning of filaments, for example, for use as surgical sutures. New methods for preparing the bioactive alkyl glycosides of
N
-acetyl-D-glucosamine (the monomer unit of chitin) and a microcrystalline chitin have encouraged their use as promoters for growth of bifidobacteria and as an aid in digestion of high-lactose cheese whey by domestic animals. Chitin-protein complexes of several crustacean species show great variability in ratios of chitin to covalently bound protein and in residual protein in the "purified" chitins.
Growth and Reshaping of Axons in the Establishment of Visual Callosal Connections
Authors: Innocenti G. M.
Published: October 2006

The visual cortical areas in the two hemispheres are interconnected by axons running through the corpus callosum. In adult cats, these axons originate from, and terminate in, tangentially restricted portions of each area. In young kittens, however, callosal axons originate from the entire extent of each area, although they apparently enter the gray matter only in the restricted regions where they will also be found in adults. In kittens, but not in adults, callosal axons also reach other regions, but there they appear to be confined to the lowest part of layer VI. During the first two postnatal months, the callosal efferent zones become progressively restricted to their adult locations. During this process, many neurons eliminate the axons (or axon collaterals) that they had formerly sent through the corpus callosum and form permanent connections ipsilaterally.
Color and Luminance: Independent Frequency Shifts
Authors: Favreau Olga Eizner , Cavanagh Patrick
Published: October 2006

Simultaneous opposite spatial frequency shifts can be obtained in chrominance and luminance channels. The chrominance shift cannot be transferred interocularly. Chrominance and luminance channels seem to perform similar but independent spatial frequency analyses.
Lysosomal Cathepsin B: Correlation with Metastatic Potential
Authors: Sloane Bonnie F. , Dunn John R. , Honn Kenneth V.
Published: October 2006

Although lysosomal enzymes are implicated in the processes of tumor invasion and metastasis, their cellular origin within the tumor is unclear. The activity of the lysosomal proteinase cathepsin B is significantly elevated in a variant of the B16 melanoma with high metastatic potential. The cathepsin B activity is localized to the lysosomes of the tumor cells.
Cancer Incidence in the Love Canal Area
Authors: Janerich Dwight T. , Burnett William S. , Feck Gerald , Hoff Margaret , Nasca Philip , Polednak Anthony P. , Greenwald Peter , Vianna Nicholas
Published: October 2006

Data from the New York Cancer Registry show no evidence for higher cancer rates associated with residence near the Love Canal toxic waste burial site in comparison with the entire state outside of New York City. Rates of liver cancer, lymphoma, and leukemia, which were selected for special attention, were not consistently elevated. Among the other cancers studied, a higher rate was noted only for respiratory cancer, but it was not consistent across age groups and appeared to be related to a high rate for the entire city of Niagara Falls. There was no evidence that the lung cancer rate was associated with the toxic wastes buried at the dump site.
Rapid Eye Movement Storms in Infants: Rate of Occurrence at 6 Months Predicts Mental Development at 1 Year
Authors: Becker Patricia T. , Thoman Evelyn B.
Published: October 2006

Intense rapid eye movements (REM) during sleep were investigated as a possible indication of delay in the neurodevelopment of infants. The rate of occurrence of REM storms was determined by monitoring the sleep of 15 normal, first-born infants during weeks 2 through 5 and at 3, 6, and 12 months. The amount of REM within each 10-second interval of active sleep was rated on a four-point scale based on frequency and intensity of eye movements. When the babies were 12 months old, the Bayley Scales of Mental Development were administered. A significant negative correlation was found between the frequency of REM storms at 6 months and Bayley scores at I year. To verify this, an independent sample of 14 subjects was also studied. The negative correlation was confirmed. The findings support the suggestion that by 6 months of age REM storms express dysfunction or delay in the development of central inhibitory feedback controls for sleep organization and phasic sleep-related activities.
Induced Hearing Deficit Generates Experimental Paranoia
Authors: Zimbardo Philip G. , Andersen Susan M. , Kabat Loren G.
Published: October 2006

The development of paranoid reactions was investigated in normal people experiencing a temporary loss of hearing. In a social setting, subjects made partially deaf by hypnotic suggestion, but kept unaware of the source of their deafness, became more paranoid as indicated on a variety of assessment measures. The results support a hypothesizes cognitive-social mechanism for the clinically observed relationship between paranoia and deafness in the elderly.
Morphine-Induced Attenuation of Morphine Tolerance
Authors: Siegel Shepard , Hinson Riley E. , Krank Marvin D.
Published: October 2006

Rats experienced both morphine and an environmental cue, but the cue always signaled a drug-free period. They were subsequently administered morphine in the presence of the cue, and the development of analgesic tolerance was assessed. The prior experience retarded such tolerance. The finding that a procedure of opiate administration can retard opiate tolerance suggests that an association between cues preceding the drug and the drug itself contributes to tolerance.
Exponential Decrease During Aging and Random Lifetime of Mouse Spermatogonial Stem Cells
Authors: Suzuki N. , Withers H. R.
Published: October 2006

Variation in the number of spermatogonial stem cells during the lifespan of the mouse was examined by assaying the number of clonogenic cells, that is, spermatogenic stem cells, surviving known doses of radiation. The results indicated that the stem cell number decreased exponentially with age.
Cloning Human Fetal γ Globin and Mouse α-Type Globin DNA: Preparation and Screening of Shotgun Collections
Authors: Blattner Frederick R. , Blechl Ann E. , Denniston-Thompson Katherine , Faber Harvey E. , Richards Julia E. , Slightom Jerry L. , Tucker Phillip W. , Smithies Oliver
Published: October 2006

Shotgun collections of Charon 3A bacteriophages containing Eco RI fragments of human and mouse DNA were constructed with the use of in vitro packaging. Plaques were screened by hybridization, and globin-specific clones were isolated from both human (Charon 3AHs51.1) and mouse (Charon 3AMm30.5). The fragments cloned were detected in unfractionated genomic DNA by the Southern method of hybridization.
Tricyclic Antidepressants: Long-Term Treatment Increases Responsivity of Rat Forebrain Neurons to Serotonin
Authors: de Montigny Claude , Aghajanian George K.
Published: October 2006

Long-term treatment of rats with clinically effective tricyclic antidepressant drugs induced a selective increase in the inhibitory response of forebrain neurons to serotonin applied by microiontophoresis. Long-term administration of some related drugs which lack antidepressant efficacy failed to induce such a change. The enhanced response to serotonin induced by the clinically active tricyclic drugs took 1 to 2 weeks to develop, a time course which correlates with the delayed onset of therapeutic effects in humans.
Range of Radiochemical Damage to DNA with Decay of Iodine-125
Authors: Martin Roger F. , Haseltine William A.
Published: October 2006

Studies of the length of DNA fragments produced upon decay of iodine-125-labeled deoxycytidine that was located at a single position within a DNA fragment of defined sequence demonstrate that most radiochemical damage occurs within 15 to 20 angstroms of the site of iodine-125 decay. However, DNA strand breakage was detectable up to 70 angstroms from the site of iodine-125 decay.
Science and the Universities
Authors: Fortier Claude
Published: October 2006

The university system in Canada, as well as its method of funding, was built on the expectation of growth. It is now necessary to consider what effect the expected decline in enrollment may have on the ability of the university system to serve national needs. Neither the government nor the universities have had any experience that would fit them for carrying out effectively, humanely, and economically the kind of contraction that may be required, while still maintaining the quality of education. Such an adjustment is going to require the best efforts of the universities and the two senior levels of government working in concert, as well as the support of the public. Parallels are drawn with the situation in the United States.
Vasopressin Exhibits a Rhythmic Daily Pattern in Cerebrospinal Fluid But Not in Blood
Authors: Reppert Steven M. , Artman Henry G. , Swaminathan Subbiah , Fisher Delbert A.
Published: October 2006

Examination of vasopressin concentrations in cerebrospinal fluid continuously withdrawn from free-ranging cats revealed a large daily rhythm, with high concentrations occurring during daylight hours. A similar daily pattern of the peptide was not detected in the circulation. The rhythmic fluctuation of vasopressin in the cerebrospinal fluid further implicates this body fluid as a vehicle of neuroendocrine communication and provides additional evidence that vasopressin may act by means of the cerebrospinal fluid to modulate behavioral processes, such as memory.
Glucose Transfer from Male to Female Schistosomes
Authors: Conford Eain M. , Huot Marie E.
Published: October 2006

The rate of glucose assimilation by male and female
Schistosoma mansoni
was significantly greater in copulating than separated flukes, especially in copulating females. In the three medically important schistosome species, glycogen content was greater in unpaired males than in copulating males, suggesting that the female depletes glycogen stored in the male. Transfer of [
14
C]glucose from the male to the copulating female was demonstrated over a period of minutes. A considerable portion of the glucose utilized by the female during her life may be supplied by the male.
Stepwise Sarcomere Shortening: Analysis by High-Speed Cinemicrography
Authors: Delay M. J. , Ishide N. , Jacobson R. C. , Pollack G. H. , Tirosh R.
Published: October 2006

Sarcomere shortening in striated muscle appears to follow a regionally synchronized staircase-like time course not anticipated in some cross-bridge models. The visualization method used has been criticized as subject to Bragg diffraction effects. Two independent optical methods were used to visualize a muscle during contraction; agreement between the stepwise behavior observed with the two methods suggests that the phenomenon is genuine.
Bioselective Membrane Electrode Probes
Authors: Rechnitz Garry A.
Published: October 2006

The use of intact bacterial cells or tissue slices of plant and animal origin as immobilized biocatalysts has extended the possible range of potentiometric bioselective membrane electrodes beyond that of conventional enzyme electrodes. The use of such materials as biocatalysts offers advantages in situations where isolated enzymes are not available or where multistep reaction paths are required. The resulting bioselective electrodes also offer exceptional ease of preparation, time stability, and low cost.
Modification of the Discharge of Vagal Cardiac Neurons During Learned Heart Rate Change
Authors: Gold Michael R. , Cohen David H.
Published: October 2006

Visually conditioned heart rate change in the pigeon has been developed as a vertebrate model system for the cellular neurophysiological analysis of associative learning. In previous studies of the "final common path," it was shown that both the vagal and sympathetic cardiac innervations contribute to this response. The present experiments indicate that, prior to any behavioral training, the visual stimulus elicits a small decrease in the discharge of vagal cardiac neurons. During conditioning, this stimulus evokes a progressively greater decrease in discharge that parallels the acquisition of the conditioned cardioacceleration. In contrast, nonassociative control animals show habituation of the initial decrease in discharge. These data confirm the involvement of the vagal cardiac innervation in conditioned heart rate change, indicate that the vagal innervation acts synergistically with the sympathetic to produce cardioacceleration, and suggest that a short-latency pathway mediates the conditioned response.
Oculomotor Reaction Time in Dementia Reflects Degree of Cerebral Dysfunction
Authors: Pirozzolo Francis J. , Hansch Edward C.
Published: October 2006

The effects of diffuse cerebral dysfunction on oculomotor reaction time were assessed in patients with dementia of presumed Alzheimer's etiology and in normal age-matched control subjects. Patients were classified into mild, moderate, and severe groups on the basis of independent neurological, neuropsychological, and neuroradiological ratings for disease severity. Saccadic latencies to targets appearing in parafoveal and near peripheral vision showed significant increases from the normal controls to dementia groups, with each severity subdivision clearly differentiated from the others in terms of mean oculomotor reaction time. These data offer strong evidence for a direct relationship between degree of cortical structural integrity and simple oculomotor reaction time and suggest a higher cortical regulatory role in sensory-motor integration.
Choline Stimulates Nicotinic Receptors on Adrenal Medullary Chromaffin Cells to Induce Catecholamine Secretion
Authors: Holz Ronald W. , Senter Ruth A.
Published: October 2006

Choline stimulated secretion of catecholamines from primary dissociated cultures of bovine adrenal medullary chromaffin cells by interacting with nicotinic receptors. Secretion was readily detected at a choline concentration of 1 millimole per liter and was maximal at 3 to 10 millimoles per liter; it was completely calcium-dependent. Further analysis suggested that choline acts as a partial nicotinic agonist.
Brain Pyruvate Dehydrogenase: Phosphorylation and Enzyme Activity Altered by a Training Experience
Authors: Morgan David G. , Routtenberg Aryeh
Published: October 2006

The active portion of the alpha subunit of pyruvate dehydrogenase in rat frontal cortex was elevated after a training experience. No change in total pyruvate dehydrogenase activity was observed. The phosphorylation in vitro of pyruvate dehydrogenase (band F-2) was also elevated after training. Since activation of pyruvate dehydrogenase requires its dephosphorylation, the following sequence is proposed. Training alters frontal cortex activity and reduces the phosphate content of pyruvate dehydrogenase in vivo; this leads to enzyme activation and an increase in back-titration of sites available for phosphorylation in vitro.
Chance and Consensus in Peer Review
Authors: Cole Stephen , Cole Jonathan R. , Simon Gary A.
Published: October 2006

An experiment in which 150 proposals submitted to the National Science Foundation were evaluated independently by a new set of reviewers indicates that getting a research grant depends to a significant extent on chance. The degree of disagreement within the population of eligible reviewers is such that whether or not a proposal is funded depends in a large proportion of cases upon which reviewers happen to be selected for it. No evidence of systematic bias in the selection of NSF reviewers was found.
World Population Growth, Soil Erosion, and Food Security
Authors: Brown Lester R.
Published: October 2006

Since 1950, world food output has more than doubled, but in many cases this impressive gain has been achieved by the adoption of agricultural practices that lead to an excessive rate of soil erosion. At least one-fifth, and perhaps as much as one-third, of the global cropland base is losing soil at a rate that is undermining its long-term productivity. World food production per person will eventually begin to decrease if the loss of topsoil continues at current rates. In view of this, there is an urgent need to realign national priorities everywhere in order to get the brakes on world population growth and to finance the adoption of agricultural practices that will preserve the cropland base.
Dimethyl and Monomethyl Sulfate: Presence in Coal Fly Ash and Airborne Particulate Matter
Authors: Lee Milton L. , Later Douglas W. , Rollins David K. , Eatough Delbert J. , Hansen Lee D.
Published: October 2006

Dimethyl sulfate and its hydrolysis product monomethyl sulfate have been found at concentrations as high as 830 parts per million in fly ash and in airborne particulate matter from coal combustion processes. This discovery poses a new environmental problem because of the mutagenic and carcinogenic properties of these compounds.
A Palladium-Palladium Oxide Miniature
p
H Electrode
Authors: Liu Chung-Chiun , Bocchicchio Brian C. , Overmyer Patricia A. , Neuman Michael R.
Published: October 2006

A wire-form miniature palladium-palladium oxide electrode has been fabricated for
p
H measurement. The electrode exhibits a super-Nernstian behavior and gives a mean
p
H response of 71.4 millivolts per [
p
H] (standard deviation, 5.2 millivolts). Uncorrected zero current potential values can be used to determine the
p
H value of the medium to within 0.012
p
H. The electrode should find applications in biological, medical, and clinical studies.
Pentobarbital: Stereospecific Actions of (+) and (-) Isomers Revealed on Cultured Mammalian Neurons
Authors: Huang Li-Yen Mae , Barker Jeffery L.
Published: October 2006

Stereoisomers of the barbiturate anesthetic pentobarbital were applied to mouse spinal neurons growing in tissue culture. Intracellular recordings of neuronal membrane properties revealed that the (+) and (-) isomers caused direct changes in membrane potential and conductance on some but not all of the cells tested. The action of the (+) isomer was predominantly excitatory, whereas the (-) isomer produced predominantly inhibitory responses. The (-) isomer was considerably more effective in potentiating inhibitory responses to the transmitter gamma-aminobutyric acid. The results show that pentobarbital has multiple effects on neuronal excitability and demonstrate the presence of stereospecific sites of barbiturate action on central neurons.
Red Blood Cells: Their Dual Role in Thrombus Formation
Authors: Turitto V. T. , Weiss H. J.
Published: October 2006

Red blood cells may have a physical and chemical effect on the interaction between platelets and blood vessel surfaces. Under flow conditions in which primarily physical effects prevail, platelet adhesion increases fivefold as hematocrit values increase from 10 to 40 percent but undergoes no further increase from 40 to 70 percent, implying a saturation of the transport-enhancing capabilities of red cells. For flow conditions in which platelet-surface reactivity is more dominant, platelet adhesion and thrombus formation increase monotonically as hematocrit values increase from 10 to 70 percent. Thus red cells may have a significant influence on hemostasis and thrombosis; the nature of the effect is apparently related to the flow conditions.
Behavior Patterns in Cod Released by Electrical Stimulation of Olfactory Tract Bundlets
Authors: Døving K. B. , Selset R.
Published: October 2006

The olfactory tracts in the cod (
Gadus morhua
L.) consist of four bundlets. Three were cut symmetrically on both sides leaving only one of the four bundlets intact. Weak electrical pulses given to the uncut bundlets elicited, for each, a different behavior pattern in free-swimming cod. The results support a spatial basis for olfactory discrimination and open new experimental possibilities linking the neuroanatomical substrate and fish behavior.
Ala-Gly- and Val-Asp-[Arg
8
]-Vasopressin: Bovine Storage Forms of Arginine Vasopressin with Natriuretic Activity
Authors: Gitelman H. J. , Klapper D. G. , Alderman F. R. , Blythe W. B.
Published: October 2006

Extracts of fresh-frozen bovine neurohypophysis were purified by chromatographic techniques to isolate and characterize the components that produce natriuresis in nondiuretic dogs. Two compounds with natriuretic properties similar to those of synthetic arginine vasopressin accounted for most of the natriuretic activity and appeared to be the prevalent vasopressin-like molecules in the extract. These peptides were Ala-Gly-[Arg
8
]-vasopressin and Val-Asp-[Arg
8
]-vasopressin; the natriuretic potency of each appeared to be similar to synthetic arginine vasopressin and could be observed with doses in the range of 50 picomoles. In the dog the most conspicuous difference between synthetic arginine vasopressin and the new vasopressin peptides was the smaller pressor responses to natriuretic doses of the new compounds.
Parathyroid Hormone: A Coronary Artery Vasodilator
Authors: Crass M. F. , Pang Peter K. T.
Published: October 2006

Injection of synthetic bovine parathyroid hormone (the amino terminal peptide containing the first 34 amino acids) to the coronary circulation of the dog resulted in a marked coronary vasodilation. The vasodilatory response was dose-dependent and amounted to a 161 percent increase over the resting flow rate at a concentration of 1.0 unit per kilogram.
Lateralization of Reward in Rats: Differences in Reinforcing Thresholds
Authors: Glick Stanley D. , Weaver Linda M. , Meibach Richard C.
Published: October 2006

Fourteen rats with bilaterally implanted lateral hypothalamic electrodes were allowed to self-stimulate each side of the brain during daily test sessions. Rotation (circling behavior) during self-stimulation sessions was also recorded. All rats rotated in preferential direction regardless of the side of the brain stimulated, and, in each case, the direction was the same as that subsequently determined in response to
d
-amphetamine. All rats had asymmetries in self-stimulation thresholds related to the direction of rotation. Thresholds were lower on the side contralateral to the direction of rotation, and entire rate-intensity functions were displaced to the left on that side. The results, discussed in terms of lateralization of affect, suggest a model in which quantitative differences in neuronal firing can be translated into apparent qualitative specialization, with the two sides of the brain appearing to be specialized for high and low mood, respectively.
Glucan-Induced Modification of Murine Viral Hepatitis
Authors: Williams David L. , Di Luzio Nicholas R.
Published: October 2006

Glucan, a macrophage stimulant, was evaluated for its ability to alter survival and phagocytic dysfunction in mice challenged with mouse hepatitis virus strain MHV-A59. Administration of glucan before the mice were challenged with the virus significantly prolonged median survival time but did not modify overall mortality compared with control mice given dextrose. Maximal effectiveness was achieved when glucan was administered both before and after the viral challenge. In contrast to the marked hepatic parenchymal cell necrosis observed in the control mice, glucan-treated mice exhibited reduced pathology. Intraperitoneal administration of MHV-A59 resulted in a significant depression of phagocytic activity compared with controls that were not exposed to the virus. The enhancement in phagocytic function in glucan-treated control mice was unaltered in virus-challenged, glucan-treated mice. Thus glucan is capable of increasing survival, inhibiting hepatic necrosis, and maintaining an activated state of phagocytic activity in mice challenged with MHV-A59. Macrophage stimulants may have a significant role in the modification of virally induced hepatic lesions.
Bronchial Bifurcations and Respiratory Mass Transport
Authors: Haselton F. R. , Scherer P. W.
Published: October 2006

A new transport mechanism explains the importance of the shape of bronchial bifurcations in the transfer of gases and particles between the atmosphere and the alveoli. Photographs of flow visualization experiments illustrate the effect in models of bronchial branching. The mechanism provides a means of nondiffusional transport that helps to explain normal respiratory exchange of gases as well as successful ventilation with very low tidal volumes, as in some lung diseases and in the high-frequency panting of dogs.
Inhibition of Cell Division and Growth by a Redox Series of Cyanine Dyes
Authors: Zigman Seymour , Gilman Paul
Published: October 2006

A series of cyanine dyes used in photography, with reduction potentials from -1.35 to -0.20 volts, were tested for their ability to inhibit mitosis and cell growth in fertilized sea urchin eggs. Low concentrations of dyes with reduction potentials more negative than -1.0 volt generally inhibited mitosis and growth, whereas those with more positive reduction potentials did not. The active dyes penetrated the cell, entered all subcellular compartments, were bound to numerous macromolecules, and inhibited synthesis of macromolecules. Thus mitosis and growth may be retarded with substances that can alter electrochemical activity in cells.
Calcification Inside Artificial Hearts: Inhibition by Warfarin-Sodium
Authors: Pierce William S. , Donachy James H. , Rosenberg Gerson , Baier Robert E.
Published: October 2006

Intracavitary calcium phosphate deposits were observed in smooth, elastomeric blood pump sacs implanted in male calves for periods of 115 to 166 days. These deposits occurred predominantly on the flexing surface of the sacs. In contrast, similar pump sacs remained generally free of mineral deposits for up to 150 days in calves treated with the anticoagulant warfarin-sodium. These results implicate a vitamin K-dependent process in calcium phosphate deposition on elastomeric sacs.
Regional Assignment of Genes for Human Esterase D and Retinoblastoma to Chromosome Band 13q14
Authors: Sparkes Robert S. , Sparkes Maryellen C. , Wilson Miriam G. , Towner Joseph W. , Benedict William , Murphree A. Linn , Yunis Jorge J.
Published: October 2006

The expression of human esterase D was evaluated quantitatively and qualitatively in five persons with partial deletions or duplications of chromosome 13. The results showed that the locus of this enzyme is at band 13q14. Deletion of this same band in other subjects has been found previously to indicate a predisposition to the development of retinoblastoma, which was present in the four individuals in this study who had partial deletions of chromosome 13. Because of this close synteny, esterase D evaluation should aid in the diagnosis and genetic counseling of retinoblastoma.
The Striking Resemblance of High-Resolution G-Banded Chromosomes of Man and Chimpanzee
Authors: Yunis Jorge J. , Sawyer Jeffrey R. , Dunham Kelly
Published: October 2006

The fine structure and genetic organization of the chromosomes of man and chimpanzee are so similar that it is difficult to account for their phenotypic differences.
Clinical Radioimmunodetection of Cancer with Radioactive Antibodies to Human Chorionic Gonadotropin
Authors: Goldenberg David M. , Kim Edmund E. , DeLand Frank H. , van Nagell John R. , Javadpour Nasser
Published: October 2006

Injection of iodine-131-labeled goat immunoglobulin G antibody to human chorionic gonadotropin (hCG) into patients with hCG-secreting trophoblastic and germinal tumors permitted tumor detection and location by external gamma-ray scintigraphy. Excision of one of the metastatic tumors located by this method indicated a tumor/nontumor ratio of 39.29. The method appears to offer a new clinical tool for precisely locating hCG-producing tumors in the body, even when tumor identification by other clinical methods has failed.
Social Environment as a Factor in Diet-Induced Atherosclerosis
Authors: Nerem Robert M. , Levesque Murina J. , Cornhill J. Fredrick
Published: October 2006

Rabbits on a 2 percent cholesterol diet were individually petted, held, talked to, and played with on a regular basis. Measurements of aortic affinity for a Sudan stain, serum cholesterol levels, heart rate, and blood pressure were made at the end of the experimental period. Compared to control groups, which were given the same diet and normal laboratory animal care, the experimental groups showed more than a 60 percent reduction in the percentage of aortic surface area exhibiting sudanophilic lesions, even though serum cholesterol levels, heart rate, and blood pressure were comparable.
Myocardial Infarct Imaging of Antibodies to Canine Cardiac Myosin with Indium-111-Diethylenetriamine Pentaacetic Acid
Authors: Khaw Ban An , Fallon John T. , Strauss H. William , Haber Edgar
Published: October 2006

Antibodies, by virtue of marked selectivity and affinity, may lend themselves to identification of structures of unique antigenic specificity in vivo. In experimental myocardial infarction in dogs, F(ab′)
2
fragments of antibodies to cardiac myosin that had been labeled with iodine-131 were shown to localize within the lesion. Because the energy characteristics of iodine isotopes are not ideal for imaging with a gamma camera, a new method for labeling antibody fragments with divalent or polyvalent radionuclides was developed. A bifunctional chelating agent, diethylenetriamine pentaacetic acid was covalently coupled, by an amide bond, to Fab fragments of antibodies to canine cardiac myosin. A stable chelate was then formed with indium-111, a nuclide that has appropriate half-life and energy characteristics for gamma imaging. Antibodies treated in this way retain their antigen-binding activity and are useful in locating myocardial infarcts in vivo.
Antibody-Dependent Cell-Mediated Cytotoxicity: Detection by Automated Flow Cytometry with Ultramicro Techniques
Authors: Attallah A. M. , Yeatman T. J. , Noguchi P. D. , Johnson J. B.
Published: October 2006

Antibody-dependent cell-mediated cytotoxicity can be measured with as few as 1000 leukocytes with an automated flow cytometry technique.
Recall (Versus Recognition) of Taste and Immunization Against Aversive Taste Anticipations Based on Illness
Authors: Chen Jaw-Sy , Amsel Abram
Published: October 2006

Two experiments show that, after taste-aversion conditioning, rats can use external retrieval cues to recall or anticipate the aversive taste solution and avoid its location without making contact with the flavor. They also show that the rat's avoidance of a conditioned aversive taste and its consumption of the aversive flavored solution can be attenuated by giving it prior runway training in which taste reward is given inconsistently on a partial reinforcement schedule.
Binding and Factor XIII
a
-Mediated Cross-Linking of a 27-Kilodalton Fragment of Fibronectin to
Staphylococcus aureus
Authors: Mosher Deane F. , Proctor Richard A.
Published: October 2006

A 27-kilodalton tryptic fragment, derived from the amino terminus of the 200-kilodalton fibronectin subunit, inhibited binding of intact fibronectin to
Staphylococcus aureus
and could be cross-linked to
Staphylococcus aureus
by blood coagulation Factor XIII
a
. Interactions of fibronectin with
Staphylococcus aureus
via this fragment may be important for bacterial opsonization and attachment.
Two Coronaviruses Isolated from Central Nervous System Tissue of Two Multiple Sclerosis Patients
Authors: Burks Jack S. , DeVald B. L. , Jankovsky Lynn D. , Gerdes John C.
Published: October 2006

Two coronaviruses were isolated from brain material obtained at autopsy from two multiple sclerosis patients. The viruses were neutralized by serum and spinal fluid from these patients. Although most of the population have antibody to these virus isolates, multiple sclerosis patients have slightly higher concentrations of serum antibody than controls. The results suggest that coronaviruses should be considered as one additional virus with a potential implication in the etiology of multiple sclerosis.
Human Cutaneous Leishmania in a Mouse Macrophage Line: Propagation and Isolation of Intracellular Parasites
Authors: Chang K.-P.
Published: October 2006

A mouse macrophage line, J774G8, supports continuous and prolific intracellular growth of
Leishmania mexicana amazonensis
, the etiological agent of a South American cutaneous leishmaniasis. The intracellular parasites from these infected cultures can be isolated with high recovery rate and purity by simple Percoll gradient centrifugation.
Total Reporting for Scientific Work
Authors: Mac Lane Saunders
Published: October 2006

The project grant system, which has been so effective in the support of scientific research in the United States, has included support of the indirect costs of that research. The desire to clearly justify these costs and to trace abuses has led the Office of Management and Budget to issue new rules. One such rule requires reporting for 100 percent of the work of scientists. The character of this rule raises fundamental questions about the possible control of universities by the government. This article is intended to describe the background of these questions and to examine their consequences.
Radioactive Waste: The Problem of Plutonium
Authors: Krugmann Hartmut , von Hippel Frank
Published: October 2006

Systems under development for the recovery of plutonium from spent fuel and its recycling in fresh fuel would not significantly reduce either the total α-activity or the amount of fissile plutonium in radioactive waste relative to what is possible with once-through fuel cycles.
Genotoxicity of the Antihypertensive Drugs Hydralazine and Dihydralazine
Authors: Williams Gary M. , Mazue Guy , McQueen Charlene A. , Shimada Tomiko
Published: October 2006

The genotoxicity of the antihypertensive agents hydralazine and dihydralazine was tested in mammalian cells and bacteria. Both drugs elicited DNA repair in rat hepatocyte primary cultures. In the Ames test, both with and without an S-9 fraction, hydralazine was mutagenic in strains TA100 and TA1537, whereas dihydralazine was weakly mutagenic in strain TA1537. These findings support the observation that hydralazine is carcinogenic in mice. The carcinogenicity of many chemicals results from interaction with DNA. Since these studies demonstrate that hydralazine and dihydralazine damage DNA in mammalian cells, these drugs should be viewed as potential human carcinogens.
Folic Acid: Crystal Structure and Implications for Enzyme Binding
Authors: Mastropaolo Donald , Camerman Arthur , Camerman Norman
Published: October 2006

The crystal and molecular structure of folic acid dihydrate has been determined by x-ray diffraction. Folic acid is in an extended conformation with the pteridine ring in the keto form. The C(4) oxygen and N(10) atoms are on the same side of the molecule, hydrogen-bonded to the same water. This conformation has the pteridine rotated approximately 180° away from the orientation of the pteridine ring of methotrexate bound to dihydrofolate reductase. The folic acid pteridine and phenyl rings interact in a stacking manner which is suggestive of the type of associations these groups could form in a complex of folate, dihydrofolate reductase, and reduced nicotinamide adenine dinucleotide phosphate.
Hormone Accumulation in a Sexually Dimorphic Motor Nucleus of the Rat Spinal Cord
Authors: Breedlove S. Marc , Arnold Arthur P.
Published: October 2006

The fifth and sixth lumbar segments of the rat spinal cord were found to contain a sexually dimorphic nucleus, the spinal nucleus of the bulbocavernosus (SNB). The SNB, which contains motoneurons innervating perineal striated muscles in normal male rats, is diminished or absent in normal females and in males with a genetic mutation rendering them insensitive to androgens. The presence of the nucleus is apparently not dependent on genetic sex, but on the action of androgens. The motoneurons of the adult male SNB accumulate hormone after systemic injections of radioactive testosterone or dihydrotestosterone, but not estradiol, and the SNB motoneurons accumulate more of the injected androgens than do other motoneurons in the same spinal segments. These results demonstrate a morphological sex difference in hormone-sensitive motoneurons that are probably involved in the sexually dimorphic copulatory behavior of the rat.
Attentional Factors in the Inhibition of a Reflex by a Visual Stimulus
Authors: DelPezzo Elizabeth M. , Hoffman Howard S.
Published: October 2006

A brief stimulus presented to various regions of the visual field inhibited the eyeblink elicited by a subsequent tap to the skin between the eyebrows. Subjects were able to switch their attention toward or away from the target area without moving their eyes. In doing so they changed the amount of inhibition.
Persistence of Crystallin Messenger RNA's with Reduced Translation in Hereditary Cataracts in Mice
Authors: Shinohara Toshimichi , Piatigorsky Joram
Published: October 2006

In vitro translation experiments showed that the lens fiber cells of two hereditary cataracts in mice (Nakano and Philly) possessed a full complement of crystallin messenger RNA's, despite severely reduced synthesis of crystallin in these cells. The reduction in synthesis in the lens fiber cells correlated with the increase in Na
+
and the decrease in K
+
, which occurs during cataractogenesis. In contrast to the fiber cells, the epithelial cells continued to synthesize crystallins in the cataractous lenses. Crystallin synthesis was stimulated in the fiber cells by raising the K
+
concentration and lowering the Na
+
concentration in the cultured lenses. The reduction in crystallin synthesis in the initial stages of cataractogenesis in the Nakano and Philly lenses thus appears to be due to poor utilization of crystallin messenger RNA's in the fiber cells.
p
H-Sensitive Liposomes: Possible Clinical Implications
Authors: Yatvin M. B. , Kreutz W. , Horwitz B. A. , Shinitzky M.
Published: October 2006

When
p
H-sensitive molecules are incorporated into liposomes, drugs can be specifically released from these vesicles by a change of
p
H in the ambient serum. Liposomes containing the
p
H-sensitive lipid palmitoyl homocysteine (PHC) were constructed so that the greatest
p
H differential (6.0 to 7.4) of drug release was obtained near physiological temperature. Such liposomes could be useful clinically if they enable drugs to be targeted to areas of the body in which
p
H is less than physiological, such as primary tumors and metastases or sites of inflammation and infection.
Biodegradation of Chemicals of Environmental Concern
Authors: Alexander Martin
Published: October 2006

Microorganisms in soils and waters convert many synthetic organic chemicals to inorganic products. Other compounds are transformed only by cometabolism. These microbial processes may lead to environmental detoxication, the formation of new toxicants, or the biosynthesis of persistent products. Type reactions are proposed for major categories of enzymatic transformation of synthetic chemicals in soils, natural waters, and sewage. Some organic molecules are resistant to microbial attack, and explanations for the persistence of such compounds are suggested.
Opiate Antagonist Improves Neurologic Recovery After Spinal Injury
Authors: Faden Alan I. , Jacobs Thomas P. , Holaday John W.
Published: October 2006

The opiate antagonist naloxone has been used to treat cats subjected to cervical spinal trauma. In contrast to saline-treated controls, naloxone treatment significantly improved the hypotension observed after cervical spinal injury. More critically, naloxone therapy significantly improved neurologic recovery. These findings implicate endorphins in the pathophysiology of spinal cord injury and indicate that narcotic antagonists may have a therapeutic role in this condition.
2,4,5-Trichlorophenoxyacetic Acid Causes Behavioral Effects in Chickens at Environmentally Relevant Doses
Authors: Sanderson C. A. , Rogers L. J.
Published: October 2006

Administration of the herbicide 2,4,5-trichlorophenoxyacetic acid to incubating chicken eggs alters behavior after hatching. Single doses, with no morphological effects, retard learning (lowest dose, 7 milligrams per kilogram of body weight) and increase general activity (27 milligrams per kilogram) and jumping (13 milligrams per kilogram). Day 15 of incubation is the most susceptible stage of development.