bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbohydrate Dramatically Influences Immune Reactivity of Antisera to Viral Glycoprotein Antigens
Authors: Alexander Stephen , Elder John H.
Published: October 2006

Analysis of the ability of heteroantisera, monoclonal antibodies, and antibodies to synthetic peptides to react with viral glycoproteins deglycosylated with endoglycosidase F revealed that the reactivities of most of the antibodies to these glycoprotein antigens were influenced by the attached carbohydrate moieties. All heteroantisera prepared in rabbits or goats to either fully glycosylated retroviruses or influenza virus were virtually unreactive toward the viral glycoproteins after carbohydrate removal. Analyses with a panel of monoclonal antibodies to purified Rauscher murine leukemia virus gp70 indicated that the reactivity of most of these antibodies improved while the reactivity of others decreased or remain unchanged after carbohydrate removal. Most of the antibodies to synthetic peptide sequences in the influenza virus hemagglutinin also improved in reactivity after carbohydrate removal. These data indicate that carbohydrate side chains on viral glycoproteins influence the immune response to these antigens, and the more native the glycoprotein immunogen, the more dramatic the carbohydrate influence. Thus the immune response to these glycoproteins is not simply a function of the immunogenicity of certain domains over others but rather is a direct measure of carbohydrate influences on the host's perception of the foreign antigen.
Postpartum Amenorrhea: How Is It Affected by Maternal Nutritional Status?
Authors: Huffman Sandra L. , Chowdhury A. K. M. Alauddin , Mosley W. Henry
Published: October 2006

The average length of postpartum amenorrhea reported by breast-feeding women in rural Bangladesh in 1975 was 18 to 20 months. Its duration was found to be only slightly related to maternal nutritional status. There was no evidence of a threshold of weight for height necessary for the resumption of menses postpartum. Factors related to the duration of postpartum amenorrhea were maternal age, socioeconomic status, and supplemental feeding of the infant.
Polypeptide Transforming Growth Factors Isolated from Bovine Sources and Used for Wound Healing in Vivo
Authors: Sporn Michael B. , Roberts Anita B. , Shull James H. , Smith Joseph M. , Ward Jerrold M. , Sodek Jaro
Published: October 2006

Transforming growth factors, which are polypeptides that induce the transformed phenotype in nonneoplastic cells, have been isolated in bulk amounts from bovine salivary gland and kidney. In experiments in which wound healing chambers were implanted subcutaneously in the backs of rats, these bovine transforming growth factors accelerated the accumulation of total protein, collagen, and DNA in treated chambers. These studies thus show an effect of an isolated transforming growth factor in vivo.
A Nitrogen Pressure of 50 Atmospheres Does Not Prevent Evolution of Hydrogen by Nitrogenase
Authors: Simpson Frank B. , Burris Robert H.
Published: October 2006

The effect of a partial pressure of nitrogen of 50 atmospheres (5065 kilopascals) on the hydrogen evolution reaction of nitrogenase has been investigated. Evolution of hydrogen was not blocked completely by 50 atmospheres of nitrogen in any of four experiments; rather, 27.3 ± 2.4 percent of the total electron flux through nitrogenase was directed toward production of hydrogen. The ratio of hydrogen evolved to nitrogen fixed was close to 1:1, which implies that hydrogen evolution is obligatory in the fixation of molecular nitrogen by nitrogenase.
Coping and Immunosuppression: Inescapable But Not Escapable Shock Suppresses Lymphocyte Proliferation
Authors: Laudenslager Mark L. , Ryan Susan M. , Drugan Robert C. , Hyson Richard L. , Maier Steven F.
Published: October 2006

Rats were given series of escapable shocks, identical inescapable shocks, or no shock. The subjects were reexposed to a small amount of shock 24 hours later, after which an in vitro measure of the cellular immune response was examined. Lymphocyte proliferation in response to the mitogens phytohemagglutinin and concanavalin A was suppressed in the inescapable shock group but not in the escapable shock group. This suggests that the controllability of stressors is critical in modulating immune functioning.
External Imaging of Cerebral Muscarinic Acetylcholine Receptors
Authors: Eckelman William C. , Reba Richard C. , Rzeszotarski Waclaw J. , Gibson Raymond E. , Hill Thomas , Holman B. Leonard , Budinger Thomas , Conklin James J. , Eng Robert , Grissom Michael P.
Published: October 2006

A radioiodinated ligand that binds to muscarinic acetylcholine receptors was shown to distribute in the brain by a receptor-mediated process. With single-photon-emission imaging techniques, radioactivity was detected in the cerebrum but not in the cerebellum, whereas with a flow-limited radiotracer, radioactivity was detected in cerebrum and cerebellum. Single-photon-emission computed tomography showed good definition of the caudate putamen and cortex in man.
Rectal Insemination Modifies Immune Responses in Rabbits
Authors: Richards Jon M. , Bedford J. Michael , Witkin Steven S.
Published: October 2006

Weekly deposition of pooled rabbit semen into the rectum in healthy male rabbits resulted in the appearance of immune complexes and antibodies to sperm and to peripheral blood lymphocyte antigens. It also led to a decreased ability to mount a humoral immune response to T lymphocyte-dependent antigens, keyhole limpet hemocyanin, and sheep red blood cells. These findings suggest that repeated rectal deposition of semen may compromise some aspects of the immune system.
Cat Scratch Disease: A Bacterial Infection
Authors: Wear Douglas J. , Margileth Andrew M. , Hadfield Ted L. , Fischer Gerald W. , Schlagel Charles J. , King Frank M.
Published: October 2006

Histopathologic examination of lymph nodes from 39 patients with clinical and pathological criteria for cat scratch disease revealed delicate pleomorphic Gram-negative bacilli in 34 of the 39 nodes. They were within the walls of capillaries in or near areas of follicular hyperplasia and within microabscesses. They were best seen with the Warthin-Starry silver impregnation stain. Organisms in lymph node sections exposed to convalescent serum from three patients and to immunoperoxidase stained equally well with all three samples. The organisms did not react with hyperimmune sera to
Legionella pneumophila
nor to several species of Rickettsia. These bacilli appear to be the causative agents of cat scratch disease.
Fourier Transform Infrared Spectrometry
Authors: Griffiths Peter R.
Published: October 2006

The theory and instrumentation for Fourier transform infrared spectrometry are discussed. These instruments measure infrared spectra of the same quality as spectra measured on grating spectrometers in about one thousandth of the time. Their sensitivity advantage for spectra measured in equal times is between a factor of 10 and 100. Commercial spectrometers are now available from nine vendors in North America. Important areas of chemistry include atmospheric monitoring, surface chemistry, and on-line identification of chromatographically separated materials. Many new biochemical and biomedical applications are also becoming apparent, including investigations of phase transitions in lipids and studies of the biocompatibility of implant polymers.
The Development of Human Fetal Hearing
Authors: Birnholz Jason C. , Benacerraf Beryl R.
Published: October 2006

Blink-startle responses to vibroacoustic stimulation were monitored ultrasonically in human fetuses of known gestational age. Responses were first elicited between 24 and 25 weeks of gestational age and were present consistently after 28 weeks. Defining the developmental sequence for audition provides a foundation for diagnosing deafness and recognizing aberrant responses antenatally.
Prediction of Learning Rate from the Hippocampal Electroencephalogram
Authors: Berry Stephen D. , Thompson Richard F.
Published: October 2006

Samples of spontaneous electroencephalographic (EEG) activity from the dorsal hippocampus of rabbits were recorded immediately before classical conditioning of the nictitating membrane response. Computer analysis revealed a significant predictive relationship between EEG frequency characteristics and the subsequent rate of learning.
Blood-Brain Neutral Amino Acid Transport Activity Is Increased After Portacaval Anastomosis
Authors: James J. Howard , Escourrou Jean , Fischer Josef E.
Published: October 2006

In rats after portacaval anastomosis (an animal model of chronic liver disease), transport of tryptophan and other members of the large neutral amino acid group from blood to brain was markedly enhanced. Increased transport activity was apparently restricted to the neutral amino acid transport system, since brain uptake of glucose, inulin, and tyramine was unaffected while blood-brain arginine transport was significantly reduced. These results strikingly confirm the hypothesis that carrier-mediated blood-brain transport is the limiting factor determining the availability of the neutral amino acids to the brain. The encephalopathy associated with cirrhosis may be the result of abnormal neurotransmitter metabolism and neurotransmission secondary to increased neutral amino acid transport activity and an increased brain content of members of the neutral amino acid group.
Other Tastes, Other Worlds
Authors: Dethier V. G.
Published: October 2006

The idea of four primary tastes has influenced our concept of the gustatory world of all animals. It has also been the basis for constructing theories of gustatory neural integration. Since natural chemical stimuli are complex mixtures to which responses are multineuronal, difficult questions about integration arise. Answers are usually framed in terms of "labeled line" or "across-fiber" hypotheses. Comparative studies of vertebrate and invertebrate taste reveal in all receptors universal basic parameters that bear on the controversy. Comparative studies also place in more accurate perspective diverse chemically related ecologies and behaviors.
Brain Edema: Induction in Cortical Slices by Polyunsaturated Fatty Acids
Authors: Chan Pak Hoo , Fishman Robert A.
Published: October 2006

The presence of polyunsaturated and saturated fatty acids in leukocytic membranes prompted study of their possible role in the induction of brain edema. Polyunsaturated fatty acids including sodium arachidonate, sodium linoleate, sodium linolenate, and docosahexaenoic acids induced edema in slices of rat brain cortex. This cellular edema was specific, since neither saturated fatty acids nor a fatty acid containing a single double bond had such effect.
Niemann-Pick Disease Experimental Model: Sphingomyelinase Reduction Induced by AY-9944
Authors: Sakuragawa Norio , Sakuragawa Machiko , Kuwabara Toichiro , Pentchev Peter G. , Barranger John A. , Brady Roscoe O
Published: October 2006

Organs of rats treated with the drug A Y-9944 for 5 days showed a significant reduction in sphingomyelinase activity. Evidence is presented which suggests that the reduction is due to impaired enzyme synthesis.
Actin Filament Stress Fibers in Vascular Endothelial Cells in Vivo
Authors: Wong Albert J. , Pollard Thomas D. , Herman Ira M.
Published: October 2006

Fluorescence microscopy with 7-nitrobenz-2-oxa-3-diazole phallacidin was used to survey vertebrate tissues for actin filament bundles comparable to the stress fibers of cultured cells. Such bundles were found only in vascular endothelial cells. Like the stress fibers of cultured cells, these actin filament bundles were stained in a punctate pattern by fluorescent antibodies to both alpha-actinin and myosin. The stress fibers were oriented parallel to the direction of blood flow and were prominent in endothelial cells from regions exposed to high-velocity flow, such as the left ventricle, aortic valve, and aorta. Actin bundles may help the endothelial cell to withstand hemodynamic stress.
Differential Gene Expression in the Gastrula of
Xenopus laevis
Authors: Sargent Thomas D. , Dawid Igor B.
Published: October 2006

A modified cloning method designed to produce differential complementary DNA libraries permits the isolation of sequences that are present in the RNA population of any developmental stage or tissue, but are not present or are much less abundant in another stage or tissue. Selective complementary DNA cloning is especially useful when the differentially expressed RNA's are of low to moderate abundance in the cells in which they occur. A class of cytoplasmic polyadenylated RNA's differentially expressed in gastrula embryos of
Xenopus laevis
(DG RNA's) has been isolated. These DG RNA's occur very rarely or not at all in unfertilized eggs and blastulae, accumulate as the result of transcription before and during gastrulation, and, with some exceptions, decline in abundance as development proceeds. Many of these RNA molecules appear to be translated at the gastrula stage. Thus, DG RNA's may encode proteins that are important in the process of gastrulation.
β-Carotene: an Unusual Type of Lipid Antioxidant
Authors: Burton G. W. , Ingold K. U.
Published: October 2006

The mechanism of lipid peroxidation and the manner in which antioxidants function is reviewed. β-Carotene is a purported anticancer agent, which is believed by some to have antioxidant action of a radical-trapping type. However, definitive experimental support for such action has been lacking. New experiments in vitro show that β-carotene belongs to a previously unknown class of biological antioxidants. Specifically, it exhibits good radical-trapping antioxidant behavior only at partial pressures of oxygen significantly less than 150 torr, the pressure of oxygen in normal air. Such low oxygen partial pressures are found in most tissues under physiological conditions. At higher oxygen pressures, β-carotene loses its antioxidant activity and shows an autocatalytic, prooxidant effect, particularly at relatively high concentrations. Similar oxygen-pressure-dependent behavior may be shown by other compounds containing many conjugated double bonds.
Progressive Accumulation of Toxic Metabolite in a Genetic Leukodystrophy
Authors: Igisu Hideki , Suzuki Kunihiko
Published: October 2006

Progressive accumulation of a cytotoxic metabolite, galactosylsphingosine (psychosine), was found in the brain of the twitcher mouse, a mutant caused by genetic deficiency of galactosylceramidase. Similar abnormal accumulation was also found in the brain of the genetic galactosylceramidase deficiency disease in the dog and in human patients (globoid cell leukodystrophy or Krabbe disease). Galactosylsphingosine was absent in the brains of normal and heterozygous mice. The finding provides support for the psychosine hypothesis as the biochemical pathogenetic mechanism of globoid cell leukodystrophy. Analogous mechanisms may be important in the pathogenesis of other genetic lysosomal diseases.
Competition Controls the Growth of an Identified Axonal Arborization
Authors: Murphey R. K. , Lemere C. A.
Published: October 2006

The shape of the axonal arborization was studied in an identified insect sensory neuron. The distribution of presynaptic varicosities within an axonal arbor was shown to be modulated by the density of neighboring terminals. Removal of neighbors near one portion of the axon terminal increased the growth rate in the denervated region and caused a compensatory retraction in other regions. The results support the hypothesis that the size of an axonal arbor is determined intrinsically, whereas the distribution of varicosities within the terminal is determined extrinsically by neighboring terminals. These findings provide a direct demonstration of the effects of competition on an identified nerve cell, as well as one of the first examples of competitive interactions in an invertebrate central nervous system.
Cryoprecipitate Reversal of Opsonic α
2
-Surface Binding Glycoprotein Deficiency in Septic Surgical and Trauma Patients
Authors: Saba Thomas M. , Blumenstock Frank A. , Scovill William A. , Bernard Harvey
Published: October 2006

Human opsonic α
2
-surface binding glyoprotein (α
2
SB-glycoprotein), a molecule having immunologic identity with an amino acid composition similar to cold-insoluble globulin, is concentrated in a cryoprecipitate of plasma. Septic surgical and trauma patients manifesting opsonic α
2
SB-glycoprotein deficiency and associated reticuloendothelial system dysfunction were treated by intravenous infusion of cryoprecipitate. This therapy restored circulating bioreactive and immunoreactive opsonin and improved their septicemia, pulmonary insufficiency, and duration of recovery. Cryoprecipitate infusion may offer a new approach to the treatment of septic injured patients in preventing multiple organ failure; measurement of immunoreactive serum opsonic α
2
SB-glycoprotein may provide a noninvasive index of reticuloendothelial system function and patient status during severe sepsis that follows trauma.
Visual Cortical Neurons: Are Bars or Gratings the Optimal Stimuli?
Authors: Albrecht Duane G. , De Valois Russell L. , Thorell Lisa G.
Published: October 2006

Neurons in the visual cortex of monkeys and cats have been characterized as either (i) bar and edge detectors or (ii) cells selective for certain spatial frequencies. To assess which of these functional descriptions is more accurate, we measured (i) the selectivity and (ii) the responsivity-sensitivity of these neurons to bars of various widths and gratings of various spatial frequencies. All of the cells recorded from were considerably more selective along the dimension of spatial frequency than along the dimension of bar width. Further, most were more responsive and sensitive to the grating of optimal frequency than to the bar of optimal width.
Effects of EGTA on the Calcium-Activated Afterhyperpolarization in Hippocampal CA3 Pyramidal Cells
Authors: Schwartzkroin Philip A. , Stafstrom Carl E.
Published: October 2006

Intracellular recordings in the hippocampal slice preparation were made with electrodes filled with 0.2 molar potassium EGTA. The purpose was to investigate the role of calcium in mediating afterhyperpolarizations following bursts evoked by intracellular current pulses, arising spontaneously, or induced by the epileptogenic agent penicillin. In the first two cases the afterhyperpolarization was blocked and the associated conductance increase was reduced, suggesting that EGTA was blocking the calcium-activated potassium conductance during the hyperpolarization. In the third case the afterhyperpolarization and associated conductance increase persisted, implicating an alternative mechanism for the hyperpolarization.
Migration Inhibition of Endothelial Cells by Lymphokine-Containing Supernatants
Authors: Cohen Marion C. , Picciano Paul T. , Douglas William J. , Yoshida Takeshi , Kreutzer Donald L. , Cohen Stanley
Published: October 2006

Many of the reactions of cellular immunity are mediated by soluble lymphocyte-derived factors (lymphokines). One important category of lymphokine action involves effects on cell motility. These effects have been described mainly with respect to inflammatory cells. In this report, we describe the ability of a lymphocyte product to inhibit the migration of endothelial cells in a system in vitro. The responsible factor is distinct from a previously described mediator that inhibits the migration of tumor cells. The ability of lymphocytes to influence the migration properties of endothelial cells is consistent with data of others showing a relation between the immune system and processes involving neovascularization.
Phase Transition and Crystal Structure of the 37°C Form of Cholesterol
Authors: Hsu Leh-Yeh , Nordman C. E.
Published: October 2006

Crystalline cholesterol undergoes a phase transition a few degrees below human body temperature. The high-temperature form has an unusually complex structure with 16 independent molecules. In the transition two molecules change side chain conformation, four reorient about their long axes, and ten remain unchanged. The transition mechanism implies relatively nonspecific intermolecular interactions, qualitatively consistent with the behavior of cholesterol in biomembranes. The transition preserves a remarkably closely obeyed pseudosymmetry present in the structure.
Plutonium in Drinking Water: Effects of Chlorination on Its Maximum Permissible Concentration
Authors: Larsen R. P. , Oldham R. D.
Published: October 2006

Soluble plutonium is oxidized to the Pu(VI) oxidation state by chlorine during water treatment. Under certain conditions Pu(VI) is readily absorbed from the gastrointestinal tract. It appears that due consideration has not been given to the effect that the presence of plutonium in this oxidation state may have on the maximum permissible concentration of plutonium in drinking water.
Light and Agonists Alter Pineal
N
-Acetyltransferase Induction by Vasoactive Intestinal Polypeptide
Authors: Yuwiler Arthur
Published: October 2006

Vasoactive intestinal polypeptide stimulated serotonin
N
-acetyltransferase activity in rat pineal glands in organ culture by a postsynaptic action that was independent of the beta-receptor. The magnitude of stimulation could be altered by environmental lighting conditions and by prior exposure to the agonist. Such up- and down-regulation, well known for catecholaminergic stimulation of this system, is compatible with a possible control of the pineal by vasoactive intestinal polypeptide as well as by catecholamines.
Quinolinic Acid: An Endogenous Metabolite That Produces Axon-Sparing Lesions in Rat Brain
Authors: Schwarcz Robert , Whetsell William O. , Mangano Richard M.
Published: October 2006

A current hypothesis links the neuroexcitatory properties of certain acidic amino acids to their ability to cause selective neuronal lesions. Intracerebral injection of the neuroexcitatory tryptophan metabolite, quinolinic acid, has behavioral, neurochemical, and neuropathological consequences reminiscent of those of exogenous excitotoxins, such as kainic and ibotenic acids. Its qualities as a neurotoxic agent suggest that quinolinic acid should be considered as a possible pathogenic factor in neurodegenerative disorders.
Myosin Light Chain Phosphorylation Does Not Modulate Cross-Bridge Cycling Rate in Mouse Skeletal Muscle
Authors: Butler Thomas M. , Siegman Marion J. , Mooers Susan U. , Barsotti Robert J.
Published: October 2006

An attempt was made to determine whether phosphorylation of the myosin light chain represents a thick filament-associated mechanism for modulating the rate of cross-bridge cycling in mouse skeletal muscle. When the degree of light chain phosphorylation was varied independently of tetanus duration, there was no correlation of phosphorylation with cross-bridge turnover rate, as measured by the shortening velocity of the muscle. It is concluded that in intact skeletal muscle phosphorylation of the myosin light chain does not in itself modulate cross-bridge cycling rate and that previously reported changes in cycling rate were due to other factors that may vary with tetanus duration.
Urinary Phenyl Acetate: A Diagnostic Test for Depression?
Authors: Sabelli H. C. , Fawcett J. , Gusovsky F. , Javaid J. , Edwards J. , Jeffriess H.
Published: October 2006

The compound 2-phenylethylamine is an "endogenous amphetamine" which may modulate central adrenergic functions. 2-Phenylethylamine is mainly metabolized by monoamine oxidase to form phenyl acetate (PAA). The 24-hour urinary excretion of PAA was measured in normal healthy volunteers and depressed patients. Patients were diagnosed according to the
Diagnostic and Statistical Manual of Mental Disorders
, edition 3. In 70 percent of healthy volunteers of both sexes, the excretion of PAA ranged between 70 and 175 milligrams per 24 hours (mean = 141.1 ± 10.2). Inpatients with major depressive disorder (unipolar type) (
N
= 31) excreted less PAA (68.7 ± 7.0 milligrams per 24 hours) and 55 percent of them excreted less than 70 milligrams per 24 hours; there were no significant differences in the PAA excretion between untreated patients (
N
= 13) and those treated with antidepressants that were not effective (
N
= 18). The PAA excretion was reduced to a lesser extent in 35 less severely depressed unipolar outpatients (drug-free for 1 week) (86.3 ± 11.8 milligrams per 24 hours). These results suggest that low PAA urinary excretion may be a reliable state marker for the diagnosis of some forms of unipolar major depressive disorders.
Forms of Memory Failure
Authors: Weingartner Herbert , Grafman Jordan , Boutelle William , Kaye Walter , Martin Peter R.
Published: October 2006

Memory may fail in a variety of ways. Patients with Korsakoff's syndrome demonstrate global memory deficits similar to those seen in patients with early progressive dementia. Korsakoff's patients, however, may recall rules and principles for organizing information and can gain access to their previously acquired knowledge (semantic memory), whereas recent memory may be grossly impaired. In contrast, dementia patients may have little access to previously acquired knowledge and therefore have great difficulty in organizing and encoding ongoing events. These contrasting forms of memory failure have implications for understanding the structure and mechanisms of memory and learning, particularly the relationship between episodic and semantic memory, as well as the development of therapeutic strategies for cognitive impairments.
Interactions Among Converging Sensory Inputs in the Superior Colliculus
Authors: Meredith M. Alex , Stein Barry E.
Published: October 2006

The responses of superior colliculus cells to a given sensory stimulus were influenced by the presence or absence of other sensory cues. By pooling sensory inputs, many superior colliculus cells seem to amplify the effects of subtle environmental cues in certain conditions, whereas in others, responses to normally effective stimuli can be blocked. The observations illustrate the dynamic, interactive nature of the multisensory inputs which characterize the deeper laminae of the superior colliculus.
Evidence for Olfactory Function in Utero
Authors: Pedersen Patricia E. , Stewart William B. , Greer Charles A. , Shepherd Gordon M.
Published: October 2006

Pregnant rats received 2-[
14
C]deoxy-D-glucose (2DG) intravenously on the last day of gestation, and their fetuses were delivered 1 hour later by cesarean section. Fetal brains showed high 2DG uptake spread throughout the accessory olfactory bulb and little or no differential uptake in the main olfactory bulb. These findings demonstrate that functional activity occurs in the accessory olfactory bulb in utero and suggest that the accessory olfactory system may be the pathway by which fetal rats detect the odor quality of their intrauterine milieu.
The Immune Response Evokes Changes in Brain Noradrenergic Neurons
Authors: Besedovsky Hugo , del Rey Adriana , Sorkin Ernst , Da Prada Mosé , Burri Roland , Honegger Conrad
Published: October 2006

A decreased noradrenaline turnover in the hypothalami of rats was observed at the peak of the immune response to sheep red blood cells. The decrease in noradrenergic neuronal activity was mimicked by injection of soluble mediators released by immunological cells activated in vitro. Noradrenaline also tended to decrease in the brainstem but not in the residual brain. It is suggested that products released from activated immunological cells during the immune response may induce the previously described autonomic and endocrine mechanisms that contribute to immunoregulation.
Alcohol Self-Administration Disrupts Reproductive Function in Female Macaque Monkeys
Authors: Mello Nancy K. , Bree Mark P. , Mendelson Jack H. , Ellingboe James , King Norval W. , Sehgal Prabhat
Published: October 2006

Female macaque monkeys self-administered high doses of alcohol (2.9 to 4.4 grams per kilogram per day) for 3 to 6½ months. Amenorrhea, atrophy of the uterus, decreased ovarian mass, and significant depression of luteinizing hormone levels were associated with chronic alcohol intoxication. Reproductive system failure in female primates following self-induced dependence on alcohol parallels the results of clinical studies of alcoholic women.
Science, Risk, and Public Policy
Authors: Ruckelshaus William D.
Published: October 2006

A climate of fear now dominates the discussion of environmental issues. The scientific community can help alleviate this fear by making a greater effort to explain to the public the uncertainties involved in estimates of risk. Current statutory mandates designed to protect public health both demand levels of protection that technology cannot achieve and are uncoordinated across government agencies. A common statutory framework for dealing with environmental risks is needed. In addition, care must be taken to separate the scientific process of assessing risk from the use of such assessments, together with economic and policy considerations, in the management of risks through regulatory action.
A New Subtype of Human T-Cell Leukemia Virus (HTLV-II) Associated with a T-Cell Variant of Hairy Cell Leukemia
Authors: Kalyanaraman V. S. , Sarngadharan M. G. , Robert-Guroff Marjorie , Miyoshi Isao , Blayney Douglas , Golde David , Gallo Robert C.
Published: October 2006

Human T-cell leukemia virus (HTLV) is a human type-C RNA tumor virus (retrovirus) previously identified in and isolated from several patients with T-cell leukemias or lymphomas. The known virus isolates from the United States and Japan are closely related and are found in adults with an acute malignancy of mature T cells. A related retrovirus has been found in a patient (Mo) with a somewhat different disease (a T-cell variant of relatively benign hairy cell leukemia). Serum from Mo contains antibodies to the major internal core protein (p24) of HTLV. A T-cell line established from the spleen of Mo expresses HTLV antigens. However, HTLV from Mo is significantly different from all previous HTLV isolates in immunological cross-reactivity tests of p24. The usual prototype HTLV isolate is represented as HTLV-I, and the HTLV from Mo is represented as HTLV-II. Individual members of each subgroup may then be identified by subscript initials of the patient [for example, HTLV-I
(CR)
, HTLV-I
(MB)
, and HTLV-II
(Mo)
].
Insulin Binding Sites Localized to Nerve Terminals in Rat Median Eminence and Arcuate Nucleus
Authors: van Houten Mark , Posner Barry I. , Kopriwa Beatrix M. , Brawer James R.
Published: October 2006

Specific binding sites for blood-borne insulin were determined to be selectively localized on axons and axon terminals in the external median eminence and the hypothalamic arcuate nucleus by means of quantitative fine structural radioautography. This localization suggests that discrete populations of hypothalamic nerve terminals are potential targets for the direct effects of insulin and that insulin may act through synaptic mechanisms to influence hypothalamic circuits regulating energy balance and hypophyseal function.
Minerals Formed by Organisms
Authors: Lowenstam Heinz A.
Published: October 2006

Organisms are capable of forming a diverse array of minerals, some of which cannot be formed inorganically in the biosphere. The initial precipitates may differ from the form in which they are finally stabilized, or during development of the organism one mineral may substitute for another. Biogenic minerals commonly have attributes which distinguish them from their inorganic counterparts. They fulfill important biological functions. They have been formed in ever-increasing amounts during the last 600 million years and have radically altered the character of the biosphere.
The Hormonal Control of Sexual Development
Authors: Wilson Jean D. , George Fredrick W. , Griffin James E.
Published: October 2006

Male and female human embryos develop identically during the first phase of gestation. The indifferent gonads then differentiate into ovaries or testes and soon begin to secrete their characteristic hormones. If ovaries (or no gonads) are present the final phenotype is female; thus no gonadal hormones are required for female development during embryogenesis. Two hormones of the fetal testis—Müllerian regression hormone and testosterone—are responsible for the formation of the male phenotype. Analysis of fibroblasts from the skin of patients with abnormalities of sexual development due to single gene defects shows that testosterone is responsible for virilization of the male internal genital tract, that its derivative dihydrotestosterone causes development of the male external genitalia, and that both hormones act in the embryo by the same receptor mechanisms operative in postnatal life.
Blood-Brain Glucose Transfer: Repression in Chronic Hyperglycemia
Authors: Gjedde Albert , Crone Christian
Published: October 2006

Diabetic patients with increased plasma glucose concentrations may develop cerebral symptoms of hypoglycemia when their plasma glucose is rapidly lowered to normal concentrations. The symptoms may indicate insufficient transport of glucose from blood to brain. In rats with chronic hyperglycemia the maximum glucose transport capacity of the blood-brain barrier decreased from 400 to 290 micromoles per 100 grams per minute. When plasma glucose was lowered to normal values, the glucose transport rate into brain was 20 percent below normal. This suggests that repressive changes of the glucose transport mechanism occur in brain endothelial cells in response to increased plasma glucose.
Haptoglobin: A Natural Bacteriostat
Authors: Eaton John W. , Brandt Paul , Mahoney John R. , Lee James T.
Published: October 2006

The combination of bacteria and blood in a wound can have lethal consequences, probably because hemoglobin iron supports prolific bacterial growth. Rats inoculated intraperitoneally with pathogenic
Escherichia coli
and small amounts of hemoglobin die. Simultaneous administration of haptoglobin, a naturally occurring hemoglobin-binding protein, fully protects against lethality. Therefore, haptoglobin may not only accelerate the clearance of free hemoglobin, but also limit its utilization by adventitious bacteria. Haptoglobin may have therapeutic potential in the treatment of life-threatening, hemoglobin-driven bacterial infections.
Dietary Restriction in Mice Beginning at 1 Year of Age: Effect on Life-Span and Spontaneous Cancer Incidence
Authors: Weindruch Richard , Walford Roy L.
Published: October 2006

Lifelong dietary restriction beginning at 3 to 6 weeks of age in rodents is known to decelerate the rate of aging, increase mean and maximum life-spans, and inhibit the occurrence of many spontaneous cancers. Little is known about the effects of dietary restriction started in middle age. In the experiments now reported the food intake of 12- to 13-month-old mice of two long-lived strains was restricted by using nutrient-enriched diets in accordance with the concept of "undernutrition without malnutrition." The mice on the restricted diet averaged 10 to 20 percent increases in mean and maximum survival times compared to the control mice. Spontaneous lymphoma was inhibited by the food restriction.
Endogenous Opiates and Energy Balance
Authors: Mandenoff A. , Fumeron F. , Apfelbaum M. , Margules D. L.
Published: October 2006

Increasing the palatability of food has two opposite effects: it promotes overeating and provokes caloric output (energy expenditure). The increase in energy expenditure is too small to compensate for overeating and, as a result, obesity occurs. Repeated administration of zinc tannate of naloxone, a long-lasting opiate antagonist, completely abolishes this diet-induced obesity in rats. The drug accomplishes this not only by reducing overeating but also by increasing energy expenditure. This suggests that endogenous opioid peptides encourage obesity in two ways—by stimulating appetite for palatable foods and by reducing energy expenditures.
Endemic Pleural Disease Associated with Exposure to Mixed Fibrous Dust in Turkey
Authors: Rohl A. N. , Langer A. M. , Moncure G. , Selikoff I. J. , Fischbein A.
Published: October 2006

Pleural mesothelioma, lung cancer, pleural calcification and fibrosis, and interstitial parenchymal fibrosis have been observed among inhabitants of several villages in south-central Turkey. Earlier reports have stated that environmental and lung tissue samples from this area contained the fibrous zeolite mineral erionite, and this mineral has generally been assumed to be the agent responsible for these endemic pathological conditions in the absence of asbestos outcroppings and usage. Several different kinds of asbestos minerals in addition to erionite have now been found in environmental samples taken from the villages where these diseases occur. The lung tissues of mesothelioma patients from these villages contain both fibrous zeolites and asbestos minerals.
Cellular Mechanism of Neuronal Synchronization in Epilepsy
Authors: Traub Roger D. , Wong Robert K. S.
Published: October 2006

Interictal spikes are a simple kind of epileptic neuronal activity. Field potentials and intracellular recordings observed during interictal spikes of penicillin-treated slices of the hippocampus were reproduced by a mathematical model of a network of 100 hippocampal neurons from the region including CA2 and CA3. The model shows that this form of neuronal synchronization arises because of mutual excitation between neurons, each of which is capable of intrinsic bursting in response to a brief input.
Human Myeloma Cell Line Carrying a Philadelphia Chromosome
Authors: Karpas Abraham , Fischer Patricia , Swirsky David
Published: October 2006

A new human plasmacytoma cell line (Karpas 707) has been established from a myeloma patient. The cultured cells are negative for Epstein-Barr viral nuclear antigen and free of mycoplasma. They are similar to plasma cells and secrete only lambda light chains. The cells are hypodiploid and contain the Philadelphia chromosome and other abnormalities. This cell line may be suitable for the production of human monoclonal antibodies.
General Anesthetics Hyperpolarize Neurons in the Vertebrate Central Nervous System
Authors: Nicoll R. A. , Madison D. V.
Published: October 2006

The effect of general anesthetics on frog motoneurons and rat hippocampal pyramidal cells was examined with sucrose gap and intracellular recording, respectively. A number of volatile and intravenous anesthetics directly hyperpolarized the motoneurons. The potency of these agents in hyperpolarizing motoneurons was strongly correlated with their anesthetic potency. While the responses to barbiturates and α-chloralose were blocked by γ-aminobutyric acid antagonists and were dependent on the chloride gradient, the responses to all the other anesthetics tested were generated by a separate mechanism. Intracellular recording from hippocampal pyramidal cells suggested that an increase in potassium conductance accounts for these responses. Such a nonsynaptic action would contribute to the decreased neuronal responsiveness observed for these compounds and thus to their anesthetic action.
Development of Mouse Embryos in Vitro: Preimplantation to the Limb Bud Stage
Authors: Chen L. T. , Hsu Y. C.
Published: October 2006

Mouse embryos were grown successfully in vitro from the blastocyst stage to the limb bud stage. Mouse blastocysts grown in vitro for 10 days showed blood circulation in the yolk sac, forelimb buds, and the primordia of liver, pancreas, and lungs. These characteristics are indicative of a developmental stage equivalent to one-half of the total gestation period in utero. Improvements in culture conditions from days 7 to 9 have made it feasible to culture mouse blastocysts beyond the early somite stage.
Stimulation of Feeding in Rats by Intraperitoneal Injection of Antibodies to Glucagon
Authors: Langhans W. , Zeiger U. , Scharrer E. , Geary N.
Published: October 2006

Intraperitoneal injections of antibodies to pancreatic glucagon at the onset of the first meal after 12 hours of food deprivation increased meal size 63 percent and meal duration 74 percent in rats. The antibodies also reduced the increase in hepatic vein blood glucose that occurred during meals in control rats, but did not affect the prandial increase in portal vein blood glucose. These results suggest that, under these conditions, pancreatic glucagon is necessary for the normal termination of meals.
Manipulation of Event-Related Potential Manifestations of Information Processing Stages
Authors: Ritter Walter , Simson Richard , Vaughan Herbert G. , Macht Michael
Published: October 2006

The timing of two event-related potential components was differentially affected by two experimental variables. The earlier component (N
A
) was affected by degradation of the stimuli and the later component (N2) by the nature of a classification task. The results support the hypothesis that N
A
and N2 reflect sequential stages of information processing, namely, pattern recognition and stimulus classification.
β-Endorphin Is Associated with Overeating in Genetically Obese Mice (
ob
/
ob
) and Rats (
fa
/
fa
)
Authors: Margules David L. , Moisset Beatriz , Lewis Michael J. , Shibuya Haruo , Pert Candace B.
Published: October 2006

Small doses of the opiate antagonist naloxone selectively abolished overeating in genetically obese mice (
ob
/
ob
) and rats (
fa
/
fa
). Elevated concentrations of the naturally occurring opiate β-endorphin were found in the pituitaries of both obese species and in the blood plasma of the obese rats. Brain levels of β-endorphin and Leu-enkephalin were unchanged. These data suggest that excess pituitary β-endorphin may play a role in the development of the overeating and obesity syndrome.
Motile Flagellum with a "3 + 0" Ultrastructure
Authors: Prensier Gérard , Vivier Emile , Goldstein Stuart , Schrével Joseph
Published: October 2006

The male gamete of the parasitic protozoan
Diplauxis hatti
has a flagellum consisting of three doublet microtubules. This flagellum exhibits a helicoidal waveform in which bends propagate toward the tip with a frequency of about 1.5 hertz. It is the simplest motile eukaryotic flagellum yet described.
Niemann-Pick Disease: A Genetic Model in Siamese Cats
Authors: Wenger David A. , Sattler Martha , Kudoh Tooru , Snyder Stanley P. , Kingston Richard S.
Published: October 2006

Three Siamese cats were found to have a progressive neurological disease that became obvious when they were 4 to 5 months of age. Their brains contained an excess of G
M2
and G
M3
gangliosides, and their livers a nine- to tenfold excess of sphingomyelin and cholesterol. A total deficiency of lysosomal (
p
H 5.0) sphingomyelinase was found in the leukocytes, liver, and brain of the cats, although the activity of the microsomal (
p
H 7.4, magnesium-dependent) sphingomyelinase was normal in brain. These cats appear to have a genetic disease identical to Niemann-Pick disease type A.
Dorsal Root Ganglion Neurons Are Destroyed by Exposure in Utero to Maternal Antibody to Nerve Growth Factor
Authors: Johnson Eugene M. , Gorin Pamela D. , Brandeis Leslie D. , Pearson John
Published: October 2006

Rats and guinea pigs, when immunized with mouse nerve growth factor, produce antibodies that cross-react with their own nerve growth factor. The antibodies reach developing offspring of these animals both prenatally (rats and guinea pigs) and postnatally (rats). Depriving the fetus of nerve growth factor in this way results in the destruction of up to 85 percent of dorsal root ganglion neurons as well as destruction of sympathetic neurons. Sensory neurons of placodal origin in the nodose ganglion were not affected. These data demonstrate that dorsal root ganglion neurons go through a phase of nerve growth factor dependence in vivo.
Selection of a Novel Connection by Adult Molluscan Neurons
Authors: Bulloch A. G. M. , Kater S. B.
Published: October 2006

Predictable changes in neuronal connectivity can be induced in the buccal ganglia of adult
Helisoma
snails when neuritic growth is evoked by axotomy. Both transient and stable novel electrical connections are established between identified neurons. The breaking of inappropriate, normally transient connections is contingent on the formation of an appropriate connection.
Brain, Lung, and Heart Functions During Diving and Recovery
Authors: Hochachka P. W.
Published: October 2006

Cooperative metabolic functions of central organs stabilize fluctuations in glucose and lactate in the blood and tissues through diving and recovery cycles.
Gated Sodium-23 Nuclear Magnetic Resonance Images of an Isolated Perfused Working Rat Heart
Authors: DeLayre Jean L. , Ingwall Joanne S. , Malloy Craig , Fossel Eric T.
Published: October 2006

Sodium-23 nuclear magnetic resonance images of phantoms and gated images of isolated perfused working rat hearts were obtained. By synchronizing the nuclear magnetic resonance process to the heartbeat, images were obtained at systole and at diastole.
DDT-Induced Feminization of Gull Embryos
Authors: Fry D. Michael , Toone C. Kuehler
Published: October 2006

Injection of DDT [1, 1, 1-trichloro-2,2-bis(
p
-chlorophenyl)ethane] into gull eggs at concentrations comparable to those found in contaminated seabird eggs in 1970 induces abnormal development of ovarian tissue and oviducts in male embryos. Developmental feminization of males is associated with inability to breed as adults and may explain the highly skewed sex ratio and reduced number of male gulls breeding on Santa Barbara Island in southern California.
Acetylcholine and Bradykinin Relax Intrapulmonary Arteries by Acting on Endothelial Cells: Role in Lung Vascular Diseases
Authors: Chand Naresh , Altura Burton M.
Published: October 2006

Acetylcholine and bradykinin produced potent relaxation of isolated canine intrapulmonary arteries contracted by serotonin, norepinephrine, or phenylephrine-provided the endothelium was left intact. Selective mechanical destruction of the endothelium transformed the activity of these substances from vasodilatation to vasoconstriction. Acetylcholine-induced relaxations, in the presence of intact endothelium, could be selectively inhibited competitively by atropine, but could not be inhibited by cyclooxygenase inhibitors, a lipoxygenase inhibitor, adrenergic blocking drugs, or histaminergic antagonists. Relaxations produced by prostacyclin, prostaglandin E
1
, isoproterenol, papaverine, or histamine H
2
-receptor agonists were not modified, or attenuated, by selective destruction of pulmonary endothelial cells. These observations might provide insight into the etiology of the increased pulmonary resistance observed in pulmonary hypertension and shock lung.
Long-Term Stress-Induced Analgesia and Activation of the Opiate System
Authors: Grau James W. , Hyson Richard L. , Maier Steven F. , Madden John , Barchas Jack D.
Published: October 2006

Exposure of rats to a series of inescapable shocks produced in sequence both an early naltrexone-insensitive and a late naltrexone-reversible analgesic reaction. Activation of the opiate system was necessary and sufficient to produce an analgesic reaction 24 hours later on exposure to a small amount of shock. The amount of inescapable shock which induced naltrexone-reversible analgesia also produced hyperreactivity to morphine 24 hours later.
Merkel Cell Receptors: Structure and Transducer Function
Authors: Gottschaldt Kay-Michael , Vahle-Hinz Christiane
Published: October 2006

An electron microscopic and electrophysiological investigation was made of Merkel cell-neurite complexes in the sinus hair follicles of the cat. These mechanoreceptors respond with very precise phase locking to high-frequency vibratory stimuli as well as to static hair displacements. The mechanoelectric transduction process is faster than that known for any other somatic mechanoreceptor. These data show that the nerve endings themselves and not the Merkel cells are the mechanoelectric transducer elements in these receptors.