bluuebunny/crossref_metadata_2025 huggingface dataset:
Insulin as a Potent, Specific Growth Factor in a Rat Hepatoma Cell Line
Authors: Koontz John W. , Iwahashi Mieko
Published: October 2006

A line of rat hepatoma cells in culture which, in response to serum starvation, become arrested in the early G
1
phase of growth, can be stimulated by insulin alone to enter the cell cycle and traverse S phase. A half-maximum response is observed at 30 to 70 picomolar concentrations and the maximum response is essentially identical to that found with optimum serum concentrations.
In Vitro Cultivation of the Exoerythrocytic Stage of
Plasmodium berghei
from Sporozoites
Authors: Hollingdale Michael R. , Leef James L. , McCullough Maryalice , Beaudoin Richard L.
Published: October 2006

When inoculated with sporozoites of
Plasmodium berghei
, the human embryonic lung cell line WI38 supports the complete asexual developmental cycle of the exoerythrocytic stage. Cultured parasites were sensitive to primaquine, were shown to resemble parasites in living hosts by immunofluorescent antibody tests, and on subinoculation into mice induced a red blood cell infection, the gametocytes of which produced sporozoites in anopheline mosquitoes.
Immunohistochemical Demonstration of a Testicular Substance Related to Luteinizing Hormone-Releasing Hormone
Authors: Paull W. K. , Turkelson C. M. , Thomas C. R. , Arimura A.
Published: October 2006

A substance related to luteinizing hormone-releasing hormone was demonstrated, by immunohistochemical procedures, in the cytoplasm of interstitial cells within the rat testes. In many seminiferous tubules, nuclei of spermatogonial cells were also immunopositive. Both cytoplasmic and nuclear fractions of testicular homogenates contain immunoreactive compounds, and this report identifies which cell types contain this substance. The localization of a peptide hormone within the nucleus of a target cell population may indicate its mode of action.
Regional Differences in the Growth of Normal and Neoplastic Cells
Authors: Auerbach Robert , Auerbach Wanda
Published: October 2006

This article provides a review of the literature on anteroposterior differences in the growth and functional expression of normal and neoplastic cells. Diverse studies in immunology, wound healing, carcinogenesis, transplantation biology, and developmental biology are brought together to emphasize the practical implications of regional differences for research protocols in all these areas of research. The more fundamental question of mechanisms is approached by consideration of variations in the vascular supply, pattern of nervous system development, expression of temperature differentials, and the establishment of metabolic gradients during development.
Obesity and Adipocyte Abnormalities in Offspring of Rats Undernourished During Pregnancy
Authors: Jones Alan P. , Friedman Mark I.
Published: October 2006

Pregnant rats underfed in the first 2 weeks of gestation had offspring with normal body weight at birth and weaning. However, starting at about 5 weeks of age the male offspring became hyperphagic and gained more weight than the controls. The female offspring did not overeat and did not become obese. Both male and female progeny showed increased fat cell size as adults. In males the epididymal and retroperitoneal fat pads were significantly enlarged and adipocytes in these pads were hypertrophied. In females the fat pads were not enlarged, but adipocytes in the parametrial pads were hypertrophied.
Systemic Lupus Erythematosus-Like Syndrome in Monkeys Fed Alfalfa Sprouts: Role of a Nonprotein Amino Acid
Authors: Malinow M. René , Bardana Emil J. , Pirofsky Bernard , Craig Shirley , McLaughlin Phyllis
Published: October 2006

Hematologic and serologic abnormalities similar to those observed in human systemic lupus erythematosus (SLE) developed in cynomolgus macaques fed alfalfa sprouts. L-Canavanine sulfate, a constituent of alfalfa sprouts, was incorporated into the diet and reactivated the syndrome in monkeys in which an SLE-like syndrome had previously been induced by the ingestion of alfalfa seeds or sprouts.
The Human Genes for
S
-Adenosylhomocysteine Hydrolase and Adenosine Deaminase Are Syntenic on Chromosome 20
Authors: Hershfield Michael S. , Francke Uta
Published: October 2006

Human-Chinese hamster cell hybrids and a monoclonal antibody to human
S
-adenosylhomocysteine hydrolase were used to identify chromosome 20 as the location of the human gene for this enzyme. The gene for adenosine deaminase had previously been mapped to this chromosome. The activity of
S
-adenosylhomocysteine hydrolase is dependent in vivo on that of adenosine deaminase, since the substrates for the deaminase, adenosine and deoxyadenosine, respectively, inhibit and inactivate
S
-adenosylhomocysteine hydrolase in genetic or drug-induced adenosine deaminase deficiency. This functional dependence and the likelihood that
S
-adenosylhomocysteine hydrolase, a eukaryotic enzyme, arose later than adenosine deaminase, which occurs in prokaryotes as well as eukaryotes, suggest that the occurrence of their genes on the same chromosome may have evolutionary significance. In addition, the unusual capacity of
S
-adenosylhomocysteine hydrolase to form stable complexes with adenosine and its cofactor, nicotinamide adenine dinucleotide, suggest that evolution of its gene may have involved recombination of a portion of the adenosine deaminase gene with an adenine nucleotide domain-coding sequence of another preexisting gene.
Brain Injury Causes a Time-Dependent Increase in Neuronotrophic Activity at the Lesion Site
Authors: Nieto-Sampedro M. , Lewis Ellen R. , Cotman Carl W. , Manthorpe Marston , Skaper Stephen D. , Barbin Gilles , Longo Frank M. , Varon Silvio
Published: October 2006

A cavity was made in the brain (entorhinal cortex) of developing or adult rats, and a small piece of Gelfoam was emplaced to collect fluid secreted into the wound. The neuronotrophic activity of the fluid was assayed with sympathetic and parasympathetic neurons in culture. The results show that wounds in the brain of developing or adult rats stimulate the accumulation of neuronotrophic factors and that the activity of these factors increases over the first few days after infliction of the damage.
Monozygotic Twin Formation in Mouse Embryos in Vitro
Authors: Hsu Yu-Chih , Gonda Matthew A.
Published: October 2006

Monozygotic twins developed from cultured murine blastocysts at the ratio of approximately 1:100. The locus at which the denuded blastocysts attached to the culture dish was usually a random section of their mural trophoblasts, in which case single egg cylinders developed unilaterally. However, in those few blastocysts attaching with their antipolar mural trophoblasts, the inner cell mass became subdivided into two parts because of restrictions imposed on its growth by the apically situated polar trophoblasts and the plastic substrate. Each subdivision apparently incorporated totipotent cells, resulting in the bilateral formation of two egg cylinders sharing the same ectoplacental cone.
Autocidal Control of Screwworms in North America
Authors: Richardson R. H. , Ellison J. R. , Averhoff W. W.
Published: October 2006

The larva of the blowflyCochliomyia hominivorax, also known as the screwworm, eats the living flesh of cattle and sheep and other warm-blooded animals. A program to eradicate the screwworm in the United States was initiated in the 1950's. The program was very effective until 1968, but severe screwworm outbreaks occurred in 1972 to 1976 and in 1978. Although the program has again been effective since 1979, the possibility of outbreaks recurring in the future has highlighted the need for a broader understanding of the pest. Studies of screwworm populations in the United States and Mexico indicate that much of the genetic diversity of this insect is distributed among sympatric non-interbreeding populations. A new approach may be required to retain the effectiveness of the control program and to prevent a serious outbreak from threatening the economic viability of the U.S. livestock industry.
Nitrogen-13-Labeled Nitrite and Nitrate: Distribution and Metabolism After Intratracheal Administration
Authors: Parks Norris J. , Krohn Kenneth A. , Mathis Chester A. , Chasko Joseph H. , Geiger Kenneth R. , Gregor Marsha E. , Peek Neal F.
Published: October 2006

Radioactive nitrogen-13 from nitrite (NO
2
-
) or nitrate (NO
3
-
) administered intratracheally or intravenously without added carrier to mice or rabbits was distributed evenly throughout most organs and tissues regardless of the entry route or the anion administered. Nitrogen-13 from both anions was distributed uniformly between plasma and blood cells. We found rapid in vivo oxidation of NO
2
-
to NO
3
-
at concentrations of 2 to 3 nanomoles per liter in blood. Over 50 percent oxidation within 10 minutes accounted for the similar nitrogen-13 distributions from both parent ions. The oxidation rates were animal species-dependent. No reduction of
13
NO
3
-
to
13
NO
2
-
was observed. A mechanistic hypothesis invoking oxidation of
13
NO
2
-
by a catalase-hydrogen peroxide complex accounts for the results. These results imply a concentration dependence for the in vivo fate of NO
2
-
or nitrogen dioxide.
Ctenidial Autotomy in
Corbicula fluminea
In Response to Massive Granulomas
Authors: Britton Joseph C. , Barcellona Wayne J. , Hagan John , LaGrone Mark L.
Published: October 2006

Large granulomas (greater than 2 millimeters in diameter), stimulated by the presence of and formed around necrotic larval tissue in the inner demibranchs of
Corbicula fluminea
, are eliminated by autotomy. Granulocytes invade and destroy ctenidial epithelium adjacent to the granuloma, causing it and the granuloma to slough away into the mantle cavity, where they are removed as pseudofeces.
Purified Reduced Nicotinamide Adenine Dinucleotide: Responses to Lactate Dehydrogenase Isozymes from Three Cell Sources
Authors: Kaplan Ann E. , Weiss Ellen R. , Byrne Sharon T. , El-Torkey Nabil M. , Margolis Sam A.
Published: October 2006

Lactate dehydrogenase (LDH, E.C. 1.1.1.27) isozymes from three single-cell sources reacted differently with reduced nicotinamide adenine dinucleotide (NADH) purified to published chromatographic and spectrophotometric specifications and free of inhibitors of LDH, when compared with a commercial preparation of NADH. The activity of LDH-1, purified from rabbit erythrocytes, increased the most with inhibitor-free NADH; the next most stimulated were the LDH isozymes from a control hepatocyte line; but hardly responsive at all were the same isozymes from chemically transformed cells. Thus isozyme composition alone did not account for the range of responses to purified NADH. The commercial preparation of NADH used in these studies contains the Strandjord-Clayson inhibitors, the most potent group identified in NADH preparations relative to LDH activity. The results suggest that specific molecular differences in individual isozymes contribute to the differential response to the Strandjord-Clayson inhibitors.
Tyrosine Increases Blood Pressure in Hypotensive Rats
Authors: Conlay Lydia A. , Maher Timothy J. , Wurtman Richard J.
Published: October 2006

Administration of tyrosine, the amino acid precursor of catecholamines, increased blood pressure 38 to 49 percent in rats made acutely hypotensive by hemorrhage; other large neutral amino acids were ineffective. Tyrosine's effect was abolished by adrenalectomy, suggesting that, in hypotensive animals, it acts by accelerating the peripheral synthesis and release of catecholamines.
Membrane Fusion Through Point Defects in Bilayers
Authors: Hui S. W. , Stewart T. P. , Boni L. T. , Yeagle P. L.
Published: October 2006

Fusion between bilayers of mixed egg phosphatidylcholine and soybean phosphatidylethanolamine was induced by freezing and thawing. Contact points between bilayers were observed by freeze fracture electron microscopy, and isotropic molecular motional averaging was detected by phosphorus-31 nuclear magnetic resonance under fusion conditions. A molecular model of point defect structure is proposed as an intermediate stage of fusion.
Genetically Determined Deficiency of the Third Component of Complement in the Dog
Authors: Winkelstein Jerry A. , Cork Linda Collins , Griffin Diane E. , Griffin John W. , Adams Robert J. , Price Donald L.
Published: October 2006

A genetically determined deficiency of the third component of complement (C3) has been identified in a colony of Brittany spaniels. Immunochemical methods show no detectable C3 in the serum of the affected dogs, and there is no evidence of an inhibitor of C3 in the serum. The C3 deficiency appears to be transmitted as an autosomal recessive trait.
Niacin Reduces Paraquat Toxicity in Rats
Authors: Brown Olen R. , Heitkamp Michael , Song Cheng-Shu
Published: October 2006

Rats poisoned with paraquat benefited from daily niacin therapy. Niacin-treated rats showed delayed and reduced dyspnea. Deaths began approximately 30 hours later. The time required for niacin-treated rats to reach 50 percent mortality increased from 60 to 120 hours, and the death rate was reduced from 75 to 55 percent. The benefit by niacin is consistent with the demonstrated role of niacin in preventing cellular decreases of nicotinamide adenine dinucleotide during poisoning of bacteria by paraquat and by hyperbaric oxygen.
Carcinogenicity in Mice of Mutagenic Compounds from a Tryptophan Pyrolyzate
Authors: Matsukura Norio , Kawachi Takashi , Morino Kazuhide , Ohgaki Hiroko , Sugimura Takashi , Takayama Shozo
Published: October 2006

The compounds 3-amino-1,4-dimethyl-5
H
-pyrido[4,3-
b
]indole and 3-amino-1-methyl-5
H
-pyrido[4,3-
b
]indole, which are potent mutagens in a tryptophan pyrolyzate, are hepatic carcinogens when given orally to mice at concentrations of 200 parts per million in a pellet diet. Female mice showed higher susceptibilities to both compounds than male mice.
Chloramphenicol Administration During Brain Development: Impairment of Avoidance Learning in Adulthood
Authors: Bertolini Alfio , Poggioli Rosanna
Published: October 2006

Rats treated with chloramphenicol from days 7 to 21 of intrauterine life (50 milligrams per kilogram per day, injected subcutaneously into the mothers) or in the first 3 days of extrauterine life (50 to 100 milligrams per kilogram per day) were trained for avoidance conditioning when 60 days old. The acquisition of the avoidance response was impaired to a highly significant degree in all the treated groups.
Ethanol Tolerance in the Rat Is Learned
Authors: Wenger John R. , Tiffany Teresa M. , Bombardier Charles , Nicholls Kathleen , Woods Stephen C.
Published: October 2006

Rats were trained to walk on a treadmill to avoid foot shock. The animals developed tolerance for ethanol if given subsequent practice while ethanol-intoxicated. Rats given equivalent doses of ethanol after practice did not develop tolerance, nor did saline-treated controls. These results challenge the hypothesis that mere repeated doses of ethanol are sufficient to induce tolerance. It seems that tolerance does not develop unless the response used to measure tolerance is performed while the subject is intoxicated.
Bulk Solute Extrusion as a Mechanism Conferring Solute Uptake Specificity by Pinocytosis in
Amoeba proteus
Authors: Prusch Robert D.
Published: October 2006

A variety of positively charged solutes induce pinocytosis in Amoeba proteus, ranging from metabolically useful material to solutes that may prove harmful, such as Alcian blue. Alcian blue is taken up by pinocytosis and then a fraction of the accumulated dye is expelled in bulk form through "extrusion channels." This response is not elicited by other solutes taken up by pinocytosis in the amoeba, implying that if any selectivity is associated with this process, it is by specific solute extrusion mechanisms in the cytoplasm.
Rational Approaches to Chemotherapy: Antisickling Agents
Authors: Klotz Irving M. , Haney David N. , King L. Carroll
Published: October 2006

The rationale leading to the design and synthesis of double-headed aspirins as potential antisickling agents is described.
Radioactivity Measurements of Former Military Personnel Exposed to Weapon Debris
Authors: Toohey R. E. , Rundo J. , Essling M. A. , Sha J. Y. , Oldham R. D. , Sedlet J. , Robinson J. J.
Published: October 2006

Sixteen former military personnel who were present at the "Smoky" atmospheric nuclear weapon test have been investigated for internal deposits of radioactivity. Whole-body and thorax gamma-ray measurements, thorax and skeletal actinide measurements, and urinalyses for plutonium-239 and strontium-90 indicated no evidence of radioactivity in excess of that found in the general population.
Science and Technology for Development
Authors: Berlinguet Louis
Published: October 2006

Science and technology are an integral part of international development, and it is important to convince our governments in the developed countries that money invested in science and technology in the Third World is for the mutual benefit of all.
Central Noradrenergic Pathways for the Integration of Hypothalamic Neuroendocrine and Autonomic Responses
Authors: Sawchenko P. E. , Swanson L. W.
Published: October 2006

Immunohistochemical and axonal transport methods were used to describe the organization of a series of central noradrenergic pathways that interrelate the nucleus of the solitary tract, which receives primary visceral sensory information, and the paraventricular and supraoptic nuclei of the hypothalamus, which participate in autonomic and neuroendocrine modes of homeostatic control. The results indicate that pathways arising from noradrenergic cells in the dorsal vagal complex, the ventrolateral medulla, and the locus coeruleus end in specific subdivisions of the paraventricular and supraoptic nuclei which are involved in the regulation of responses from the pituitary gland and from both divisions of the autonomic nervous system. This circuitry may play an important role in the integration of hypothalamic responses to visceral stimuli.
Hydrogen-Ion Concentration of the Alimentary Tracts of Fowl, Cat and Rabbit
Authors: McLaughlin Alvah R.
Published: October 2006

Herein has been presented the results secured in determining the pH of the gastrointestinal tract of the hen, the rabbit and the cat by means of the quinhydrone electrode.
Risk and Benefit in Environmental Law
Authors: Ricci Paolo F. , Molton Lawrence S.
Published: October 2006

Judicial review establishes whether the mandate of Congress is observed by an agency's rule-making mechanisms for setting environmental standards or other regulations. Central issues in risk assessment now include whether a risk is significant, what the burden of proof for significance is, how to resolve the tension between the effort to reduce hazardous exposures and the goal of efficient regulation, and precisely how and in what detail the costs of regulation must be measured. Under current regulatory statutes, there are several paradigms for balancing costs and benefits.
Intestinal Diffusion Barrier: Unstirred Water Layer or Membrane Surface Mucous Coat?
Authors: Smithson Kenneth W. , Millar David B. , Jacobs Lucien R. , Gray Gary M.
Published: October 2006

The dimensions of the small intestinal diffusion barrier interposed between luminal nutrients and their membrane receptors were determined from kinetic analysis of substrate hydrolysis by integral surface membrane enzymes. The calculated equivalent thickness of the unstirred water layer was too large to be compatible with the known dimensions of rat intestine. The discrepancy could be reconciled by consideration of the mucous coat overlying the intestinal surface membrane. Integral surface membrane proteins could not be labeled by an iodine-125 probe unless the surface coat was first removed. The mucoprotein surface coat appears to constitute an important diffusion barrier for nutrients seeking their digestive and transport sites on the outer intestinal membrane.
Hepatitis B "e" Antigen: An Apparent Association with Lactate Dehydrogenase Isozyme-5
Authors: Vyas G. N. , Peterson D. L. , Townsend R. M. , Damle S. R. , Magnius L. O.
Published: October 2006

Serums containing the "e" antigen of hepatitis B virus were subjected to electrophoresis in polyacrylamide gel. An extra band appeared in the lactate dehydrogenase isozyme pattern, but this band was undetectable in serums containing antibodies to the e antigenic determinant. Prior separation of the lactate dehydrogenase isozyme-5 fraction by chromatography of serum on minicolumns of diethylaminoethyl-Sephadex-A50 improved electrophoretic identification of the extra band. Neutralization with antibodies to the e antigen as well as by antibodies to the homologous d or y component of the hepatitis B surface antigen removed the extra band; antibodies to the lactate dehydrogenase isozyme-5 removed both the normal and the extra enzymatic band of isozyme-5. This feature of the e antigen provides an assay system for laboratory diagnosis of potential clinical usefulness and suggests its possible role in pathogenesis of hepatocellular injury.
Doridosine: a New Hypotensive
N
-Methylpurine Riboside from the Nudibranch
Anisodoris nobilis
Authors: Fuhrman Frederick A. , Fuhrman Geraldine J. , Kim Yong H. , Pavelka Lee A. , Mosher Harry S.
Published: October 2006

A new
N
-methylpurine riboside (doridosine), probably
N
1
-methylisoguanosine, was isolated from the digestive glands of a nudibranch. Doridosine produces prolonged hypotension and bradycardia in anesthetized rats, decreases the rate and the amplitude of contraction of guinea pig atria in vitro, and causes the heart rate in anesthetized mice to be reduced by 50 percent for many hours after which the animals recover completely.
New Protein Sequenator with Increased Sensitivity
Authors: Hunkapiller Michael W. , Hood Leroy E.
Published: October 2006

New developments in automated amino acid sequence analysis permit a 10
4
-fold increase in sensitivity (to ∼ 10-picomole level) over that initially described by Per Edman in 1967.
Distribution of Active Gene Sequences: A Subset Associated with Tightly Bound Chromosomal Proteins
Authors: Gates David M. , Bekhor Isaac
Published: October 2006

The distribution of active polyadenylate-messenger RNA sequences in fractionated chicken liver chromatin was examined. A portion of these active gene sequences is concentrated in a DNA fraction retained by tightly bound nonhistone chromosomal proteins, while the nonretained DNA fraction is substantially depleted of a portion of these sequences. These findings suggest that the tightly bound nonhistones are physically associated with a subset of active gene sequences.
Visual Effects of Auditory Deprivation: Common Intermodal and Intramodal Factors
Authors: Bross Michael , Harper Dan , Sicz George
Published: October 2006

Visual temporal acuity, as measured by the critical flicker frequency decreased and then increased during 24 hours of auditory deprivation. This intermodal effect is similar to intramodal changes in the critical flicker frequency of the nonoccluded eye during monocular deprivation; a single mechanism appears to underlie both phenomena.
Filter-Mediated Color Vision with One Visual Pigment
Authors: Kong King-Leung , Fung Yau Man , Wasserman Gerald S.
Published: October 2006

The compound eye of the grasshopper
Phlaeoba
has alternating bands that appear clear or brown. Electroretinograms recorded from the individual bands have different action spectra: The spectrum of the clear band peaks at 525 nanometers and that of the brown band at 545 nanometers. Spectrally selective whole-eye adaptation with light of either long or short wavelength yields identical action spectra. This evidence suggests that this eye has only one visual pigment, whose spectrum is altered in the brown bands by a screening pigment. In behavioral tests of spontaneous choices between stimuli that appear green to the normal human and those that appear red, the green stimuli are preferred even when the relative intensity is varied by 0.9 log units around the equal-brightness level (determined by the electroretinogram). When some red light is mixed with the green light, the preference for the mixture is less than for the green light alone, even though the mixture is more intense. True color vision therefore seems to exist. Painting the bands shows that behavioral color vision requires the presence of both types. These data suggest that
Phlaeoba
has true color vision mediated by one visual pigment and suitable optical filters.
Elevated Superoxide Dismutase in Black Alcoholics
Authors: Del Villano Bert C. , Miller Sheldon I. , Schacter Lee P. , Tischfield J. A.
Published: October 2006

Superoxide dismutase concentrations in lysates of erythrocytes from black alcoholics were higher than those of white alcoholics and of nonalcoholics of both races. Higher concentrations of enzyme protein, as determined by competition radioimmunoassay, correspond to proportionately higher enzyme activity. Elevated superoxide dismutase levels were not related to any other clinical, historical, or demographic variables. Increased superoxide dismutase levels may delay or prevent some of the pathological sequelae of alcoholism and may be a useful biological marker for alcohol abuse.
Tissue Specificity of Enzyme Expression Regulated by Diffusible Factors: Evidence in
Drosophila
Hybrids
Authors: Dickinson W. J.
Published: October 2006

Pairs of hybridizable species of Hawaiian picture-winged
Drosophila
differ qualitatively in the distributions of specific enzymes in their tissues. An examination of the patterns of enzyme expression in the hybrids showed that, in three instances, absence of an enzyme from a specific tissue was dominant to presence. Since other developmental features indicated that both parental genomes were functioning, these results suggest that, in these cases, the pattern differences in the parental species were due to diffusible factors that affected expression of the relevant structural genes rather than to differences in the genes themselves or in
cis
-acting regulatory sites.
Local Effect of the Blastocyst on Estrogen and Progesterone Receptors in the Rat Endometrium
Authors: Logeat Frédérique , Sartor Pierre , Vu Hai Mai Thu , Milgrom Edwin
Published: October 2006

Nuclear receptors for both estradiol and progesterone were present in twofold higher concentrations in implantation sites than in nonimplantation regions of the endometrium of 6-day pregnant rats. Decidualization in the absence of an embryo was not accompanied by a similar increase in the concentration of nuclear receptors. Moreover, this difference in receptor distribution between the implantation and nonimplantation areas persisted when a major part of the maternal supply of sex steroids was suppressed by ovariectomy on day 5 of pregnancy. These results support the hypothesis that steroids originating from the embryo affect the endometrial implantation site.
Diphenylhydantoin: Pre- and Postnatal Administration Alters Diazepam Binding in Developing Rat Cerebral Cortex
Authors: Gallager Dorothy W. , Mallorga Pierre
Published: October 2006

Close correlations between the development of the anticonvulsant effects of diphenylhydantoin and increases in tritiated diazepam binding were observed in rats from fetal day 16 to maturation. In contrast, significant decreases in tritiated diazepam binding were observed in 2- and 3-week-old rats that were exposed in utero to diphenylhydantoin. These changes can be correlated with reported increases in seizure susceptibility after prenatal exposure to diphenylhydantoin.
Mild Cold Exposure Increases Survival in Rats with Medial Preoptic Lesions
Authors: Nagel Jennifer A. , Satinoff Evelyn
Published: October 2006

High mortality rates in rats with large medial preoptic lesions discourage their use in studies of brain function. However, virtually all such animals (six out of seven) survived indefinitely if kept at an ambient temperature of 15°C for 2 hours before and 10 to 12 hours after the lesions were made. Although these rats appeared otherwise healthy, they could not maintain normal body temperatures in short-term cold tests. In contrast, five of the nine rats kept at 25°C died within 10 hours after the operation, and three more died within 5 days. Rats kept at 25°C had a much higher incidence of cardiac arrhythmias than did rats kept at 15°C, which may be responsible for their higher mortality rates.
Cadmium Increases Tissue Factor (Coagulation Factor III) Activity by Facilitating Its Reassociation with Lipids
Authors: Carson Steven D. , Konigsberg William H.
Published: October 2006

The coagulant activity of partially purified and delipidated tissue factor (TF) (coagulation Factor III) has previously been recovered by dialysis of the apoprotein after addition of mixed brain lipids and deoxycholate. Inclusion of cadmium chloride in the relipidation mixture greatly increases the recovered activity of highly purified TF from human placenta by promoting incorporation of TF into phospholipid vesicles; TF that had not been incorporated into vesicles showed no coagulant activity. Thus, TF must be present in a lipid bilayer for expression of coagulant activity. In vitro, cadmium induces fusion of lipid vesicles and may contribute to the incorporation of proteins in membranes.
Endothelial Cells of Bovine Pulmonary Artery Lack Receptors for C3b and for the Fc Portion of Immunoglobulin G
Authors: Ryan Una S. , Schultz Duane R. , Del Vecchio Peter J. , Ryan James W.
Published: October 2006

Bovine pulmonary endothelial cells do not possess receptors for the 3b component of complement (C3b) or for the Fc portion of immunoglobulin G. The lack of these receptors may help explain the nonthrombogenic function of endothelial cells. Our findings rule out the possibility that endothelial cells participate in pulmonary immune complex disease through the binding of C3b or Fc fragments.
Feeding Increases Dopamine Metabolism in the Rat Brain
Authors: Heffner Thomas G. , Hartman John A. , Seiden Lewis S.
Published: October 2006

Feeding induced by food deprivation is accompanied by an increased production of the dopamine metabolite 3,4-dihydroxyphenylacetic acid in the brains of rats. This neurochemical change occurs in the nucleus accumbens, the posterior hypothalamus, and the amygdala but not in other dopaminergic nerve terminal fields such as the corpus striatum. These results indicate that the release of dopamine from particular groups of central neurons is increased during feeding and suggest that anatomically distinct subgroups of central dopaminergic neurons serve different roles in the regulation of food intake.
Analysis of the 1957-1958 Soviet Nuclear Accident
Authors: Trabalka John R. , Eyman L. Dean , Auerbach Stanley I.
Published: October 2006

The presence of an extensive environmental contamination zone in Cheliabinsk Province of the Soviet Union, associated with an accident in the winter of 1957 to 1958 involving the atmospheric release of fission wastes, appears to have been confirmed, primarily by an analysis of the Soviet radioecology literature. The contamination zone is estimated to contain 10
5
to 10
6
curies of strontium-90 (reference radionuclide); a relatively small fraction of the total may have been dispersed as an aerosol. A plausible explanation for the incident is the use of now-obsolete techniques for waste storage and cesium-137 isotope separation. However, the source of the contamination was not unequivocally attributable to a single event, and its exact nature must await release of more information by the Soviet Union. Radioactive contamination appears to have resulted in resettlement of the human population from a significant area (100 to 1000 square kilometers). It therefore seems imperative to obtain a complete explanation of the cause (or causes) and consequences of the accident; Soviet experience gained in the application of corrective measures would be invaluable to the world nuclear community.
Pain Responses in Nepalese Porters
Authors: Clark W. Crawford , Clark Susanne Bennett
Published: October 2006

When tested by the method of limits, Nepalese had much higher pain thresholds to electrical stimulation than Occidentals did. Discriminability was the same for both groups, however, indicating that there were no neurosensory differences. Nepalese had higher (stoical) criteria for reporting pain but were not less sensitive to noxious stimulation. The battery of sensory measurement procedures described may be applied to any modality and are particularly applicable to difficult field conditions.
Federal Policies Affecting Vaccine Research and Production
Authors: Riddiough Michael A. , Willems Jane Sisk
Published: October 2006

The federal government is the single most important determinant of the extent of vaccine research, development, and use in the United States. Federal actions having a positive effect include the financing of vaccine research and development and of major public immunization programs. Federal policies that may be contributing to a decline in the private sector's commitment to vaccine development include an unwillingness to resolve certain liability issues. The nation depends heavily on vaccines to prevent several childhood diseases. For that and other reasons, decisive government efforts are needed to help stimulate the creation of new vaccines and to ensure the continued supply and use of existing safe and efficacious vaccines.
C-Glucuronidation of the Acetylenic Moiety of Ethchlorvynol in the Rabbit
Authors: Abolin Craig R. , Tozer Thomas N. , Craig J. Cymerman , Gruenke Larry D.
Published: October 2006

An acetylenic
C
-glucuronide of the sedative-hypnotic drug ethchlorvynol was isolated from rabbit urine as the major metabolite. The
C
-glucuronide represents a novel metabolic pathway for acetylenes and is a rare example of the formation of a carbon-glucuronide bond in mammalian systems.
Feeding: Satiety Signal from Intestine Triggers Brain's Noradrenergic Mechanism
Authors: Myers R. D. , McCaleb M. L.
Published: October 2006

Noradrenergic neurons in the hypothalamus involved in feeding and satiety are activated by gastrointestinal receptors. In the unrestrained rat, sites were first identified at which norepinephrine injected in the medial hypothalamus caused spontaneous feeding, or in the lateral hypothalamus caused no response. The activity of in vivo norepinephrine at these two sites was characterized by localized push-pull perfusion. When a nutrient was infused directly into the rat's duodenum, the synaptic release of hypothalamic norepinephrine was enhanced at lateral sites insensitive to norepinephrine, but suppressed at medial sites reactive to norepinephrine. Thus, signals from duodenal receptors are conceivably sent to the rat's brain to end feeding by way of noradrenergic inhibitory neurons in the hypothalamus.
Injectable Contraceptive Synthesis: an Example of International Cooperation
Authors: Crabbé Pierre , Diczfalusy Egon , Djerassi Carl
Published: October 2006

Since many contraceptives appropriate for use in developing countries are not of major interest to the pharmaceutical companies in developed countries, the World Health Organization has sponsored a program whereby contraceptives are developed outside the traditional pharmaceutical industry channels. This program might serve as a model for the development of other drugs or even pesticides.
Instrumentation in Clinical Chemistry
Authors: Elin Ronald J.
Published: October 2006

Major advances in instrumentation have revolutionized the clinical chemistry laboratory during the past two decades. This article focuses on some of the more recent developments in instrumentation for clinical chemistry in the areas of general chemistry, immunoassays, urinalysis, electrophoresis, chromatography, and trace metal analyses.
Neuronal Control of Acetylcholine Receptor Turnover Rate at a Vertebrate Neuromuscular Junction
Authors: Levitt Tami A. , Loring Ralph H. , Salpeter Miriam M.
Published: October 2006

The turnover rate of acetylcholine receptors at neuromuscular junctions in mice increases progressively after denervation and, after 15 days, reaches a half-time of 30 ± 5 hours. Denervation thus causes the clustered junctional acetylcholine receptors to assume the rapid turnover characteristic of extrajunctional receptors before innervation.
Maternal Glucocorticoid Hormones Influence Neurotransmitter Phenotypic Expression in Embryos
Authors: Jonakait G. Miller , Bohn Martha C. , Black Ira B.
Published: October 2006

Treatment of pregnant rats with reserpine prevented the normal disappearance of catecholamine fluorescence in presumptive neuroblasts of the embryonic gut. These cells normally express the noradrenergic phenotype transiently during embryonic development. The effect of reserpine was reproduced by treating mothers with hydrocortisone acetate. Moreover, the reserpine effect was blocked by treatment with dexamethasone, which inhibits the stress-induced increase in plasma glucocorticoids, and by mitotone, which causes adrenocortical cytolysis. It is concluded that reserpine, through the mediation of maternal glucocorticoid hormones, alters the phenotypic expression of these embryonic neuroblasts.
Resource Partitioning During Reproduction in the Norway Rat
Authors: Woodside Barbara , Wilson Ruth , Chee Phyllis , Leon Michael
Published: October 2006

Rat pups nursed by pregnant dams grow as fast as pups reared by dams that are not pregnant. Moreover, litters that were in utero during a lactation are as numerous at birth and grow as fast as pups developing in a nonlactating, pregnant mother. These litters continue to grow as fast as pups born to nonlactating dams whether or not the first litter remains after the birth of the second litter. When pregnant and lactating dams have a restricted food supply, some dams are capable of extending the duration of their pregnancies by over 2 weeks past that of nonlactating, pregnant dams. This facultative prolongation of pregnancy apparently allows females to carry normal litters to term.
Specific and Sensitive Radioimmunoassay for 3-Methoxy-4-Hydroxyphenylethyleneglycol (MOPEG)
Authors: Keeton T. Kent , Krutzsch Henry , Lovenberg Walter
Published: October 2006

Antibodies that specifically bind the norepinephrine metabolite 3-methoxy-4-hydroxyphenylethyleneglycol (MOPEG) were produced in rabbits after injection of a derivative of MOPEG conjugated with bovine thyroglobulin. A sensitive radioimmunoassay was devised with this antiserum, in which as little as 0.5 nanogram of MOPEG can be accurately measured with a final antibody dilution of 1:180. The antibody appears to be specific for MOPEG, since tritiated MOPEG was not displaced from the antibodies by norepinephrine, epinephrine, dopamine, serotonin, or their major metabolites, including MOPEG-sulfate (333 nanograms each).
Two Classes of Single-Stranded Regions in DNA from Sea Urchin Embryos
Authors: Wortzman M. S. , Baker R. F.
Published: October 2006

Native DNA from sea urchin embryos contains single-stranded regions (gaps) of up to 3000 nucleotides. The longer gaps (more than 1400 nucleotides) are nonrandomly distributed and are rich in histone gene sequences, other moderately repetitive sequences, and polypyrimidines. The shorter gaps are associated with DNA replication. A method for isolation of the two classes of single-stranded DNA pieces is reported.
Neurosecretory Granules: Evidence from an Aging Process Within the Neurohypophysis
Authors: Nordmann J. J. , Labouesse Julie
Published: October 2006

When cysteine labeled with sulfur-35 is injected into the third ventricle of the rat brain, it is first incorporated into only one of the two populations of neurosecretory granules that can be isolated on an isosmotic gradient. The second population of granules is labeled much later. Stimulation of hormone release from isolated labeled neural lobes and subsequent isolation of neurosecretory granules at different times after the injection of labeled cysteine shows that the radioactivity decreases in only one population of granules. One of the fractions of the gradient represents the granules found near the release site; the second population is probably located deeper in the nerve endings or in the nerve swellings. Whereas neurophysins are found in both populations, smaller proteins can only be detected in one. Thus it appears that neurosecretory granules undergo an aging process and that isosmotic gradients can separate the aged granules from those newly formed.
Saliva as a Chemical Cue in the Development of Social Behavior
Authors: Block Martin L. , Volpe L. Carl , Hayes Marie J.
Published: October 2006

Throughout development, Mongolian gerbils engage in conspicuous naso-oral investigations of their social partners' mouth areas. The behavioral contribution of saliva-related stimuli in regulating oral-directed responses was studied during several important phases of the gerbil's social life. Weanlings were preferentially attracted to their mother's saliva, subadults at puberty preferred saliva of littermates to that of nonlittermates, and sexually experienced males preferred the saliva of estrous females to that of nonestrous females. The use of saliva as a discriminative cue during various developmental periods suggests that oral chemostimuli have a perennial role in regulating social interchanges.
Vaginocervical Stimulation Selectively Increases Metabolic Activity in the Rat Brain
Authors: Allen T. O. , Adler N. T. , Greenberg J. H. , Reivich M.
Published: October 2006

Vaginocervical stimulation affects progesterone secretion, sperm transport, sexual receptivity, locomotion, and perception of pain in female rats. In this experiment, vaginocervical stimulation produced statistically significant increases in the metabolic uptake of carbon-14-labeled 2-deoxy-D-glucose in the following brain areas (ordered by magnitude of uptake): medial preoptic, mesencephalic reticular formation, bed nucleus of stria terminalis, dorsal raphe, and globus pallidus. The results provide information about the concurrent processing of sensory stimulation by several neural areas and indicate that the medial preoptic area is a receiving area for copulatory stimulation.
Novel Complex Polar Lipids from the Methanogenic Archaebacterium
Methanospirillum hungatei
Authors: Kushwaha S. C. , Kates M. , Sprott G. D. , Smith I. C.
Published: October 2006

The methanogenic archaebacterium
Methanospirillum hungatei
contains two unusual phosphoglycolipids that account for 64 percent of the total cellular lipids. These lipids are derivatives of the dibiphytanyl diglycerol tetraether, previously identified in methanogens. One of the free hydroxyls of this tetraether is esterified with glycerophosphoric acid, and the other is linked glycosidically to a disaccharide. The two phosphoglycolipids may function as covalently bonded lipid bilayers to impart stability and rigidity to methanogen membranes.
Tumor Surveillance: How Tumors May Resist Macrophage-Mediated Host Defense
Authors: Rhodes John , Bishop Michael , Benfield John
Published: October 2006

Both normal human serum and supernatant from explanted malignant tumors contained a heat-stable low-molecular-weight factor that inhibited monocyte activation in vitro. In contrast, serum from individuals with solid tumors enhanced monocyte activation. It is suggested that the systemic activation of monocytes that occurs in malignant disease may be an appropriate host response but that successful tumors may continue to grow because they subvert the normal physiological signal for inhibition of macrophage activation.
Mammary Cancer: Selective Action of the Estrogen Receptor Complex
Authors: Ip Margot , Milholland Richard J. , Rosen Fred , Kim Untae
Published: October 2006

Progesterone receptors in the autonomous rat mammary tumor MTW-9B are reduced 80 to 90 percent after ovariectomy, but are not reduced if ovariectomized animals are given estrogen. Tumor growth, however, is independent of estrogen status and insensitive to pharmacological doses of estradiol. This represents an unusual system characterized by a selective action of an inducing agent on the genome.
Channel Structures of Gramicidin: Characterization of Succinyl Derivatives
Authors: Bradley R. J. , Urry D. W. , Okamoto K. , Rapaka R.
Published: October 2006

Succinyl derivatives of gramicidin were tested for their ability to form channels in planar artificial lipid bilayers. Both
N
-succinyldeformylgramicidin methyl ester and charged
O
-succinylgramicidin formed channels, but the channels had markedly different sizes and lifetimes. This implies that gramicidin forms channels by end-to-end association. However, the doubly charged
N
,
O
-bissuccinyldeformylgramicidin was inactive, which suggests that only end-to-end association of gramicidin may result in channel formation.
Prenatal Diagnosis of Genetic Disorders
Authors: Omenn Gilbert S.
Published: October 2006

Sampling of amniotic fluid, visualization of the fetus, fetal blood sampling, and screening of maternal blood represent successive approaches to the diagnosis of specific genetic disorders in the second trimester of pregnancy. Clinical and ethical concerns about the appropriateness, safety, and efficacy of the techniques have led to multidisciplinary assessments at an early stage. A major growth in demand for medical and educational genetic services can be anticipated.
Dental Evidence on the Origins of the Ainu and Japanese
Authors: Turner Christy G.
Published: October 2006

New dental anthropological evidence on the questions of Ainu and Japanese origins illustrates the utility of diachronic dental information obtained from skeletal populations for microevolutionary and human origins investigations. Data from skeletal and dental collections of Shang Dynasty Chinese and from Jomon period and recent Ainu Japanese, together with information on recent Japanese dentition from published accounts, indicate a correlation between the ancient Chinese and modern Japanese and between the prehistoric Jomon people and the Ainu.
Maternal Malnutrition and Placental Transfer of α-Aminoisobutyric Acid in the Rat
Authors: Rosso P.
Published: October 2006

In the pregnant rat, dietary protein restriction reduces the transfer of
14
C-labeled α-aminoisobutyric acid from the maternal blood into the fetus. One of the causes of this phenomenon is a reduced capacity of the placenta to release into the fetus α-aminoisobutyric acid taken up from the maternal blood.
Reconstitution of Rh (D) Antigen Activity from Human Erythrocyte Membranes Solubilized by Deoxycholate
Authors: Lorusso D. J. , Green F. A.
Published: October 2006

Proteins were selectively solubilized from human erythrocyte membranes with deoxycholate. After ultracentrifugation and preliminary fractionation procedures, the detergent was removed from the soluble membranes by Bio-Beads SM-2 and dialysis against 5 millimolar magnesium chloride. Reaggregation took place with the apparent formation of vesicles which showed serologically specific Rh antigen activity.
Lipoprotein and Lecithin: Cholesterol Acyltransferase Changes in Galactosamine-Induced Rat Liver Injury
Authors: Sabesin Seymour M. , Kuiken Lois B. , Ragland James B.
Published: October 2006

Abnormal lipoproteins and decreased lecithin: cholesterol acyltransferase activity are found in rat plasma following intraperitoneal injection of D-galactosamine. The changes observed, including absence of α-lipoprotein and the presence of lipoproteins rich in phospholipid and unesterified cholesterol but deficient in cholesteryl esters, are remarkably similar to changes found in human pathologic states of lecithin: cholesterol acyltransferase deficiency. When examined by electron microscopy, all of the major lipoprotein classes isolated by ultracentrifugation showed morphological abnormalities including the formation of rouleaus consisting of disk-shaped particles.