bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancement of Oncogenesis in C3H/10T1/2 Mouse Embryo Cell Cultures by Saccharin
Authors: Mondal S. , Brankow D. W. , Heidelberger Charles
Published: October 2006

Impure and pure samples of saccharin (2 milligrams per milliliter) did not produce oncogenic transformation of C3H/10T1/2, clone 8, mouse embryo fibroblasts. However, after treatment of the cells with a nontransforming initiating dose (0.1 microgram per milliliter) of 3-methylcholanthrene, continuous treatment with either sample of saccharin (100 micrograms per milliliter) led to significant transformation. It is concluded that in this system saccharin is a cocarcinogen, probably functioning as a promoting agent that is 1000-fold less active than the tumor promoter 12-
O
-tetradecanoyl-phorbol-13-acetate.
Maternal Coordination of the Fetal Biological Clock in Utero
Authors: Reppert Steven M. , Schwartz William J.
Published: October 2006

Deoxyglucose labeled with carbon-14 was used in studying the utilization of glucose in the suprachiasmatic nuclei of fetal rats. The results showed that an entrainable circadian clock is present in the suprachiasmatic nuclei during fetal development and that the maternal circadian system coordinates the phase of the fetal clock to environmental lighting conditions.
Nucleotide Sequence Analysis of the T24 Human Bladder Carcinoma Oncogene
Authors: Reddy E. Premkumar
Published: October 2006

The nucleotide sequence of the T24 human bladder carcinoma oncogene was determined, and the coding and noncoding sequences of the genome were identified. The amino acid sequence of p21, the translational product of the T24 oncogene, was predicted from the nucleotide sequence of the oncogene. Comparison of this sequence with that of the normal cellular homolog showed that a single point mutation in the coding sequences of the T24 oncogene resulted in the acquisition of transforming properties. Other differences between the T24 oncogene and its normal cellular homolog were found in the 5′ noncoding and 3′ noncoding sequences, but these differences appear to be due to polymorphism and do not play a significant role in the transformation process.
Methyl 4,6-Dichloro-4,6-Dideoxy-α-D-Galactopyranoside: an Inhibitor of Sweet Taste Responses in Gerbils
Authors: Jakinovich William
Published: October 2006

The sugar methyl 4,6-dichloro-4,6-dideoxy-α-D-galactopyranoside (DiCl-gal) is a new type of inhibitor of the gerbil's electrophysiological taste response to sucrose or saccharin. Saturated solutions of this compound alone barely stimulate the gerbil's taste nerve. But, when mixed with sucrose or saccharin, DiCl-gal suppresses the gerbil's taste response to these two sweeteners. In contrast, when mixed with sodium chloride or hydrochloric acid, DiCl-gal does not affect the taste responses to these compounds. However, unlike other inhibitors of sweet taste, the DiCl-gal taste suppression is short-lived and occurs only when the inhibitor is combined with the sweetener.
Sulfation Preceding Deiodination of Iodothyronines in Rat Hepatocytes
Authors: Otten M. H. , Mol J. A. , Visser T. J.
Published: October 2006

In man and animals iodothyronines are metabolized by deiodination and conjugation with glucuronic acid or sulfate. Until now these processes have been regarded as independent reactions. However, in the present study a close interaction of these pathways was observed in the hepatic metabolism of 3,3′-diiodothyronine and 3,3′,5-triiodothyronine. Studies with rat hepatocytes and liver microsomes indicated that sulfation of the phenolic hydroxyl group facilitates the deiodination of these compounds.
Inhibitory Influence of Unstimulated Rods in the Human Retina: Evidence Provided by Examining Cone Flicker
Authors: Goldberg S. H. , Frumkes T. E. , Nygaard R. W.
Published: October 2006

In the parafoveal retina of human observers, cone-mediated sensitivity to flicker decreases as rods become progressively more dark-adapted. This effect is greatest when a rod response to flicker is precluded. These results indicate that rods tonically inhibit cone pathways in the dark.
Gestural Communication in Deaf Children: Noneffect of Parental Input on Language Development
Authors: Goldin-Meadow Susan , Mylander Carolyn
Published: October 2006

Young deaf children who were unable to acquire oral language naturally and who had not been exposed to a conventional manual language were found to use spontaneously a gesture system that has some of the structural characteristics of early child language. The structural aspects of this gesture system appeared to be neither modeled for the child by the gestures of an adult nor shaped by the responses of an adult. These findings suggest that the child may contribute to structural aspects of the system.
Calcium-Dependent Stress Maintenance Without Myosin Phosphorylation in Skinned Smooth Muscle
Authors: Chatterjee Meeta , Murphy Richard A.
Published: October 2006

Stress development depended on calcium-stimulated myosin phosphorylation in an arterial smooth muscle preparation in which the concentration of calcium was controlled. However, developed stress was maintained at a concentration of calcium that did not support phosphorylation. These results, in conjunction with other evidence, suggest that the interaction of two regulatory mechanisms with different calcium sensitivities regulate both stress and the rate and energetics of contraction.
Recent Trends in Fertility in Less Developed Countries
Authors: Coale Ansley J.
Published: October 2006

The rate of increase of population in less developed countries accelerated rapidly from 1850 to 1960 because of a rapid decline in mortality while fertility remained high. In the 1960's, the birth rate as a whole began to decline more rapidly than the death rate—very rapidly in some populations, most notably that of China, more gradually in others, and not at all in some of the poorest populations. The momentum of growth implies continued increase in populations for several decades even in countries where fertility has fallen the most, and very large additional increases where there has been no decline in the rate of childbearing.
Hand Preference Across Time Is Related to Intelligence in Young Girls, Not Boys
Authors: Gottfried Allen W. , Bathurst Kay
Published: October 2006

Consistency of hand preference was examined in a longitudinal study of children between 18 and 42 months of age. Results showed a sex-specific relationship between hand consistency and intellectual development. Across a variety of intellectual abilities at all ages, females with consistency of handedness were precocious compared to females without such consistency. This relationship did not hold for males.
The Neuroanatomy of Amnesia: Amygdala-Hippocampus Versus Temporal Stem
Authors: Zola-Morgan Stuart , Squire Larry R. , Mishkin Mortimer
Published: October 2006

Using a task known to be sensitive to human amnesia, we have evaluated two current hypotheses about which brain regions must be damaged to produce the disorder. Monkeys with bilateral transections of the white matter of the temporal stem were unimpaired, but monkeys with conjoint amygdala-hippocampal lesions exhibited a severe memory deficit. The results indicate that the hippocampus, amygdala, or both, but not the temporal stem, are involved in memory in the monkey and suggest that a rapprochement between the findings for the human and the nonhuman primate may be close at hand.
The AF64A-Treated Mouse: Possible Model for Central Cholinergic Hypofunction
Authors: Mantione Charles R. , Fisher Abraham , Hanin Israel
Published: October 2006

A loss in the number of functional, sodium ion-dependent, high-affinity choline transport sites was observed in the cortex and hippocampus of mice given an intracerebroventricular injection of 65 nanomoles of AF64A (ethylcholine mustard aziridinium ion) 3 days earlier. Such an effect was not observed in the striatum. This effect of AF64A represents a long-term neurochemical deficit at cholinergic nerve terminals in some brain regions which can lead to a persistent deficiency in central cholinergic transmission. The AF64A-treated animal may thus be a model for certain psychiatric or neurological disorders that appear to involve central cholinergic hypofunction.
Chemoprevention of Neonatal Jaundice: Potency of Tin-Protoporphyrin in an Animal Model
Authors: Drummond George S. , Kappas Attallah
Published: October 2006

The substantial increases of hepatic, splenic, and renal heme oxygenase levels that occur shortly after birth in neonatal rats were prevented by a single administration of tin-protoporphyrin (10 micromoles per kilogram of body weight). With this treatment serum bilirubin levels declined within 24 hours to near-normal adult levels and remained low throughout the postnatal period. Zinc-protoporphyrin at doses up to 50-fold greater than the effective dose of tin-protoporphyrin did not prevent the immediate increases in tissue heme oxygenase activities and in serum bilirubin levels that occur postnatally. Studies in vitro with microsomal heme oxygenase in human spleen indicate that tin-protoporphyrin is a potent competitive inhibitor of the oxidation of heme to bile pigment in this tissue.
The Stimulation of Metabolism by Alcohol
Authors: Seager L. D. , Verda D. J. , Burge W. E.
Published: October 2006

(1) The effect of ethyl alcohol, fat and protein, or the amino acids, on sugar metabolism was determined directly.

(2) It was found that alcohol stimulated sugar metabolism almost as much as fat and protein.

(3) From this it is concluded that alcohol, in addition to serving as a source of heat and energy, may also serve another function of the foodstuffs, namely, that of stimulating metabolism.
Differentiation of Murine Bone Marrow Stem Cells in Vitro: Long-Term Growth Promoted by a Lymphocyte-Derived Mediator
Authors: Altman Amnon , Gilmartin Thomas D. , Katz David H.
Published: October 2006

In attempts to induce differentiation of lymphoid cells from hematopoietic stem cells in vitro, the effects of allogeneic effect factor on the growth of murine bone marrow cultures were studied. Allogeneic effect factor is a soluble mediator derived from mixed secondary murine leukocyte cultures. For several weeks it supported the growth of bone marrow cultures, as indicated by the maintenance of stem cell activity, cellular proliferation, and heterogeneity. Another lymphokine, T cell growth factor, did not, Pre-T lymphocytes could be detected in these cultures for several weeks.
Tumor-Induced Anorexia in the Wistar Rat
Authors: Mordes John P. , Rossini Aldo A.
Published: October 2006

The transplantable Leydig cell tumor of Wistar rats, LTW(m), caused decreased food consumption and weight loss in the host within 2 weeks of implantation. The tumor was small, did not metastasize, and did not affect several parameters of biochemical function. When the tumors were removed, increases in food intake and body weight occurred within 72 hours and were sustained. Reimplantation of tumors caused anorexia to recur. Parabiotic pairs of rats with tumor in one partner also experienced weight loss. Those rats in parabiosis with tumor-bearing rats gained less weight than those in parabiosis with control rats. These observations suggest that the LTW(m) tumor causes anorexia and that this anorexia is mediated by a circulating substance.
Electrostatic Effects in Proteins
Authors: Perutz M. F.
Published: October 2006

Electrostatic effects dominate many aspects of protein behavior. When polypeptide chains fold up, most polar side chains seek the exterior, where they can be solvated. Water bound in the interior has been found between the domains of enzymes of the chymotrypsin family, and between the subunits of hemoglobin and tobacco mosaic virus protein. Assembly of this protein from disk to virus is triggered by electrostatic interactions between neighboring subunits. Lysozyme stabilizes the constellation of charges involved in the transition state of its substrate by both permanent and induced dipoles. All factors that lower the oxygen affinity of hemoglobin act by strengthening the salt bridges that constrain its quaternary deoxy (T) structure. Enzymes of thermophile bacteria owe their extra stability mostly to additional salt bridges. The rate of denaturation of hemoglobins by alkali is determined by the ionization of internal side chains with
pK
's of about 12.
Retention of an Associative Behavioral Change in
Hermissenda
Authors: Crow Terry J. , Alkon Daniel L.
Published: October 2006

The nudibranch mollusk
Hermissenda crassicornis
is normally attracted to a test light. Three days of training consisting of 50 trials per day of light paired with a rotational stimulus led to a significant increase, lasting for days, in the animal's response latency to enter a test light. The group that received light associated with rotation was significantly different from groups subjected to nonassociative control procedures. Modifications of well-known sensory networks may be related to a behavioral change that shares several operational features with associative learning.
Extreme Myopia Produced by Modest Change in Early Visual Experience
Authors: Wallman Josh , Turkel Joseph , Trachtman Joseph
Published: October 2006

Chicks whose vision was restricted to the frontal visual field became extremely myopic (mean, -10 diopters; maximum, -24 diopters) and had eyes of increased axial length. Animals restricted to lateral field vision did not differ from normal animals. Monocular deprivation of form vision also produced myopia and eye enlargement and, in addition, produced increased anterior chamber depth.
Ethology of Sleep Studied with Time-Lapse Photography: Postural Immobility and Sleep-Cycle Phase in Humans
Authors: Hobson J. Allan , Spagna Theodore , Malenka Robert
Published: October 2006

Human sleep is characterized by episodes of immobility punctuated by major postural shifts. The organization of this motor activity was shown with a combination of photographic and electroencephalographic recording to be periodic and related to the electroencephalographic sleep cycle. The amount of immobility as measured photographically was positively related to subjective estimates of the goodness of sleep.
Infant Astigmatism Measured by Photorefraction
Authors: Howland Howard C. , Atkinson Janette , Braddick Oliver , French Jennifer
Published: October 2006

Photorefraction of a sample of 93 infants of ages 1 day to 12 months showed that 63 percent of the subjects had astigmatism of 0.75 diopter or greater, and 12 percent greater than 2 diopters. Seventy percent of these astigmatisms were in the horizontal-vertical meridians. By comparison, only 8 percent of a sample of 26 adults tested by the same method showed astigmatism (all 0.75 to 1 diopter). The high incidence of infant astigmatism has implications for critical periods in human visual development and for infant acuity.
A Scanning Micropipette Molecule Microscope
Authors: Jarrell Joseph A. , King John G. , Mills John W.
Published: October 2006

A movable quartz micropipette, whose tip is sealed with a polymer plug, is used as a liquid-vacuum interface to a mass spectrometer. A light microscope allows observation of, and positioning of, the micropipette tip on the surface of a sample mounted in a perfusion chamber. This forms the basis of an instrument which enables one to study, in vitro, the localization of transepithelial transport of water and other molecules. Some preliminary results from the use of this instrument are presented.
Metabolic Mapping of the Brain's Response to Visual Stimulation: Studies in Humans
Authors: Phelps Michael E. , Kuhl David E. , Mazziota John C.
Published: October 2006

These studies demonstrated increasing glucose metabolic rates in the human primary (PVC) and associative (AVC) visual cortex as the complexity of visual scenes increased. The metabolic response of the AVC increased more rapidly with scene complexity than that of the PVC, indicating the greater involvement of the higher order AVC for complex visual interpretations. Increases in local metabolic activity by as much as a factor of 2 above that of control subjects with eyes closed indicate the wide range and metabolic reserve of the visual cortex.
Forebrain Connections in the Goldfish Support Telencephalic Homologies with Land Vertebrates
Authors: Echteler Stephen M. , Saidel William M.
Published: October 2006

Horseradish peroxidase injections into dorsomedial and dorsolateral regions of the goldfish (
Carassius auratus
) telencephalon demonstrate, by retrograde cell labeling, that the teleost telencephalon receives a pattern of projections from the thalamus remarkably similar to those of land vertebrates. The evidence provides support for a homology between the dorsomedial region and the corpus striatum of land vertebrates and a homology between two dorsolateral regions and the dorsal and medial pallium of land vertebrates.
Transformation of Human Leukocytes by Cocultivation with an Adult T Cell Leukemia Virus Producer Cell Line
Authors: Yamamoto Naoki , Okada Morihisa , Koyanagi Yoshio , Kannagi Mari , Hinuma Yorio
Published: October 2006

The transmission of adult T cell leukemia virus, a human retrovirus, into fresh leukocytes from normal humans was examined. One of three virus-carrying cell lines, tested after being subjected to lethal x-irradiation, consistently transformed leukocytes from adult peripheral blood and umbilical cord blood. All the transformed cell lines expressed adult T cell leukemia virus-associated antigen, but transformed lines originating from adult and umbilical cord blood exhibited T cell and non-T, non-B cell surface natures, respectively. Efforts to transform human leukocytes with cell-free virus were unsuccessful.
Automated Information Retrieval in Science and Technology
Authors: Doszkocs Tamas E. , Rapp Barbara A. , Schoolman Harold M.
Published: October 2006

The rapid advances in computer and communication technology in the 1970's have enabled large interactive scientific and technical information retrieval systems to be implemented. Major search services today offer on-line access to millions of bibliographic citations and an increasing number of "electronic handbooks." In addition, development of knowledge bases is well under way. Despite the impressive speed and flexibility of interactive retrieval systems, their impact has been lessened by limited awareness of their existence, uneven quality of retrieval, inadequate linkages among data bases, and reliance on specially trained intermediaries.
Vertebrate Cells Express Protozoan Antigen After Hybridization
Authors: Crane Mark St. J. , Dvorak James A.
Published: October 2006

Epimastigotes, the invertebrate host stage of
Trypanosoma cruzi
, the protozoan parasite causing Chagas' disease in man, were fused with vertebrate cells by using polyethylene glycol. Hybrid cells were selected on the basis of
T. cruzi
DNA complementation of biochemical deficiencies in the vertebrate cells. Some clones of the hybrid cells expressed
T. cruzi
-specific antigen. It might be possible to use selected antigens obtained from the hybrids as vaccines for immunodiagnosis or for elucidation of the pathogenesis of Chagas' disease.
The Origins of U.S. Safety Standards for Microwave Radiation
Authors: Steneck Nicholas H. , Cook Harold J. , Vander Arthur J. , Kane Gordon L.
Published: October 2006

An analysis is made of the scientific research and values influencing the policy decisions that led to the adoption of the 1966 U.S. standard for exposure to microwave radiation. This analysis is used as a tool for understanding the problems faced by those who set standards. An effort is made to unravel the complex motivations that lay behind the adoption of the microwave standard. Based on the past record, it is suggested that standard setting remain distinct from basic scientific research and that adversary procedures be used only as a last resort in seeking consensus over a proposed standard.
Some Problems of Cosmical Physics, Solved and Unsolved
Authors: Rayleigh
Published: October 2006

The great success of theoretical investigations in recent times naturally leads enterprising spirits to use them not only in interpreting what we know or can verify by observation, but to lead us into regions where experiment is not available as a check. I believe that this does nothing but good in times like ours, when there is no danger of the doctrines even of a master being unduly pressed, if the evidence of observed fact turns against them. At the same time, we must not expect too much of pure intellect unchecked by observation. Theories that do not stand the test of time pass for the most part into complete oblivion, and we are apt to forget how appallingly large a mass of wreckage the total of them represents. The next generation remembers chiefly those that survive, and does not take full advantage of the lesson of how easy it is for an apparently inevitable conclusion to be wrong. Unless the argument carries its own verification by some accurate and previously unforeseen numerical coincidence, it is hard indeed to tell if we are on the right track.
Tetracycline-Labeled Human Bone from Ancient Sudanese Nubia (A.D. 350)
Authors: Bassett Everett J. , Keith Margaret S. , Armelagos George J. , Martin Debra L. , Villanueva Antonio R.
Published: October 2006

Nubian bone recovered from an X-group cemetery (A.D. 350 to 550) exhibits a pattern of fluorescence identical to that of modern tetracycline-labeled bone. When it is viewed under ultraviolet light at 490 angstroms, fluorophors are visible as a characteristic yellow-green fluorescence on surfaces that were actively mineralizing at the time of exposure. Contamination of stored grains provided the proper environment for cultivation of tetracycline-producing Streptomycetes. Evidence for exposure to antibiotics in an archeological population is relevant to studies of the evolution of R factors and to the interpretation of health and disease within the population.
Bacterial Resistance to Ultraviolet Irradiation Under Anaerobiosis: Implications for Pre-Phanerozoic Evolution
Authors: Rambler Mitchell B. , Margulis Lynn
Published: October 2006

The concept that low concentrations of atmospheric oxygen and consequent unattenuated ultraviolet irradiation limited the emergence of Phanerozoic life, the Berkner-Marshall hypothesis, is no longer tenable. Anaerobic bacteria, which probably evolved far earlier than Metazoa, were irradiated in a special chamber under strictly anaerobic conditions. Both intrinsic resistance and photoreactivation by visible light were discovered in obligately and facultatively anaerobic microbes. Atmospheric scientists have shown that small amounts of oxygen would have limited pre-Phanerozoic surface ultraviolet irradiation to fluxes well below those used in the anaerobic experiments described. Since adequate ultraviolet protection mechanisms evolved early, the late Proterozoic appearance of Metazoa probably was not related to high fluxes of solar ultraviolet radiation.
Mechanisms of Gonadal Differentiation
Authors: Haseltine Florence P. , Ohno Susumo
Published: October 2006

Sex differentiation is the result of the translation of genetic sex into gonadal sex. Without recognizable masculinizing signals the embryonic gonad will undergo ovarian differentiation. The main determinant of gonadal differentiation appears to be the presence or absence of a cell surface antigen, called H-Y antigen. The regulation of H-Y antigen expression is complex and involves the interaction between regulatory sites on the Y chromosome, the X chromosome, and possibly the autosomes.
Falciparum Malaria-Infected Erythrocytes Specifically Bind to Cultured Human Endothelial Cells
Authors: Udeinya Iroka J. , Schmidt John A. , Aikawa Masamichi , Miller Louis H. , Green Ira
Published: October 2006

Erythrocytes infected with the late stages of the human malarial parasite
Plasmodium falciparum
became attached to a subpopulation of cultured human endothelial cells by knoblike protrusions on the surface of the infected erythrocytes. Infected erythrocytes did not bind to cultured fibroblasts; uninfected erythrocytes did not bind to either endothelial cells or fibroblasts. The results suggest a specific receptor-ligand interaction between endothelial cells and a component, or components, in the knobs of the infected erythrocytes.
The Essential Trace Elements
Authors: Mertz Walter
Published: October 2006

Essential trace elements are required by man in amounts ranging from 50 micrograms to 18 milligrams per day. Acting as catalytic or structural components of larger molecules, they have specific functions and are indispensable for life. Research during the past quarter of a century has identified as essential six trace elements whose functions were previously unknown. In addition to the long-known deficiencies of iron and iodine, signs of deficiency for chromium, copper, zinc, and selenium have been identified in free-living populations. Four trace elements were proved to be essential for two or more animal species during the past decade alone. Marginal or severe trace element imbalances can be considered risk factors for several diseases of public health importance, but proof of cause and effect relationships will depend on a more complete understanding of basic mechanisms of action and on better analytical procedures and functional tests to determine marginal trace element status in man.
6-Methoxybenzoxazolinone: A Plant Derivative That Stimulates Reproduction in
Microtus montanus
Authors: Sanders Edward H. , Gardner Pete D. , Berger Patricia J. , Negus Norman C.
Published: October 2006

A plant-derived cyclic carbamate, 6-methoxybenzoxazolinone, that stimulates reproductive activity in
Microtus montanus
has been isolated. This nonestrogenic compound may be a naturally occurring environmental cue affecting reproductive cycles in many mammals.
Thymosin Stimulates Secretion of Luteinizing Hormone-Releasing Factor
Authors: Rebar Robert W. , Miyake Akira , Low Teresa L. K. , Goldstein Allan L.
Published: October 2006

Partially purified thymosin fraction 5 and one of its synthetic peptide components, thymosin β
4
, but not thymosin α
1
, stimulated secretion of luteinizing hormone-releasing factor from superfused medial basal hypothalami from random cycling female rats. In addition, luteinizing hormone was released from pituitary glands superfused in sequence with hypothalami. No release of luteinizing hormone in response to thymosin was observed from pituitaries superfused alone. These data provide the first evidence of a direct effect of the endocrine thymus on the hypothalamus and suggest a potentially important role for thymic peptides in reproductive function.
Wound Tissue Can Utilize a Polymeric Template to Synthesize a Functional Extension of Skin
Authors: Yannas I. V. , Burke J. F. , Orgill D. P. , Skrabut E. M.
Published: October 2006

Prompt and long-term closure of full-thickness skin wounds in guinea pigs and humans is achieved by applying a bilayer polymeric membrane. The membrane comprises a top layer of a silicone elastomer and a bottom layer of a porous cross-linked network of collagen and glycosaminoglycan. The bottom layer can be seeded with a small number of autologous basal cells before grafting. No immunosuppression is used and infection, exudation, and rejection are absent. Host tissue utilizes the sterile membrane as a culture medium to synthesize neoepidermal and neodermal tissue. A functional extension of skin over the entire wound area is formed in about 4 weeks.
Reduced Sympathetic Nervous System Responsivity Associated with the Relaxation Response
Authors: Hoffman John W. , Benson Herbert , Arns Patricia A. , Stainbrook Gene L. , Landsberg Lewis , Young James B. , Gill Andrew
Published: October 2006

Sympathetic nervous system activity was assessed in experimental and control subjects who were exposed to graded orthostatic and isometric stress during monthly hospital visits. After the first session, the experimental subjects practiced a technique that elicited the relaxation response. Their concentrations of plasma norepinephrine during subsequent graded stresses were significantly higher. No such changes were noted in the control group. These results were then replicated in the control group in a crossover experiment. The groups did not differ in their heart rate and blood pressure responses. These observations are consistent with reduced norepinephrine end-organ responsivity after regular elicitation of the relaxation response.
β,γ-Peroxy Analogs of Adenosine and Guanosine Triphosphate: Synthesis and Biological Activity
Authors: Rosendahl Mary S. , Leonard Nelson J.
Published: October 2006

Extended analogs of adenosine triphosphate (ATP) and guanosine triphosphate (GTP), in which a peroxide bridge replaces the terminal bridge-oxygen of the triphosphate chain, have been synthesized. The ability of β,γ-peroxy-ATP to inhibit or substitute for ATP in representative enzyme systems and that of β,γ-peroxy-GTP, for FTP in protein synthesis was tested.
Muscle Fatigue and the Role of Transverse Tubules
Authors: Bianchi C. Paul , Narayan Srinivasa
Published: October 2006

Skeletal muscle stimulation for 300 pulses, either as single twitches or as tetani, increases the amount of calcium extracted in a Ringer solution containing strontium. The strontium is used to prevent reuptake of calcium by the transverse tubules. The accumulation of calcium in the transverse tubules during stimulation may account for muscle fatigue.
Basilar Membrane Tuning in the Cat Cochlea
Authors: Khanna Shyam M. , Leonard Debra G. B.
Published: October 2006

The mechanical response of the basilar membrane changes mainly in the peak region with trauma to the cochlea. Basilar membrane tuning curves measured in cochleas with reduced trauma begin to look similar to tuning curves of auditory nerve fibers.
Testosterone Uptake in the Brainstem of a Sound-Producing Fish
Authors: Fine Michael L. , Keefer Donald A. , Leichnetz George R.
Published: October 2006

Three nuclear areas in the medulla were implicated in the control of sound production in the oyster toadfish
Opsanus tau
. The sonic motor nucleus was labeled by retrograde transport of horseradish peroxidase injected into swimbladder sonic muscles, and an adjacent ventrolateral and a more anterior periventricular nucleus of the medulla were revealed by autoradiography with
3
H-labeled testosterone. These androgen uptake sites occur in brainstem areas corresponding to areas predicted to contain the neural centers controlling the duration and fundamental frequency of the toadfish mating call.
Excretion of β-Phenethylamine Is Elevated in Humans After Profound Stress
Authors: Paulos Manley A. , Tessel Richard E.
Published: October 2006

The urinary excretion rate of the endogenous, amphetamine-like substance β-phenethylamine was markedly elevated in human subjects in association with an initial parachuting experience. The increases were delayed in most subjects and were not correlated with changes in urinary
p
H or creatinine excretion. The data suggest a stress-related role for β-phenethylamine.
Mass Mortality of Harbor Seals: Pneumonia Associated with Influenza A Virus
Authors: Geraci J. R. , St. Aubin D. J. , Barker I. K. , Webster R. G. , Hinshaw V. S. , Bean W. J. , Ruhnke H. L. , Prescott J. H. , Early G. , Baker A. S. , Madoff S. , Schooley R. T.
Published: October 2006

More than 400 harbor seals, most of them immature, died along the New England coast between December 1979 and October 1980 of acute pneumonia associated with influenza virus, A/Seal/Mass/1/80 (H7N7). The virus has avian characteristics, replicates principally in mammals, and causes mild respiratory disease in experimentally infected seals. Concurrent infection with a previously undescribed mycoplasma or adverse environmental conditions may have triggered the epizootic. The similarities between this epizootic and other seal mortalities in the past suggest that these events may be linked by common biological and environmental factors.
Suprachiasmatic Stimulation Phase Shifts Rodent Circadian Rhythms
Authors: Rusak Benjamin , Groos Gerard
Published: October 2006

The integrity of the suprachiasmatic nuclei (SCN) of the hypothalamus is essential to the expression of normal circadian rhythms in rodents. Electrical stimulation of the SCN caused phase shifts and period changes in the freerunning feeding rhythms of rats and activity rhythms of hamsters. The phase response curve for SCN stimulation appears to parallel that for light pulses. These findings strengthen the hypothesis derived from lesion studies that the SCN are the dominant light-entrained oscillators in the rodent circadian system.
Alterations in Precision of the Crossed Retinotectal Projection During Chick Development
Authors: McLoon Steven C.
Published: October 2006

Chick embryos received partial eye lesions. Examination of the embryos early in development showed the partial retina projecting across the entire tectum. At later stages the partial retina projected only to the appropriate portion of the tectum. The results suggest that the retina initially projects diffusely to the tectum and that the topographically aberrant projections are eliminated during subsequent development.
Widespread Periodic Intrinsic Connections in the Tree Shrew Visual Cortex
Authors: Rockland Kathleen S. , Lund Jennifer S.
Published: October 2006

Intrinsic connections within the tree shrew (
Tupaia glis
) visual cortex (area 17) are organized in periodic stripelike patterns within layers I, II, and III. This anatomical network resembles the regularly organized stripes of 2-deoxyglucose accumulation seen after stimulation of alert animals with uniformly oriented lines. Such connections imply that widespread lateral interactions are superimposed on the retinotopic organization of area 17 and suggest alternative interpretations of cortical columns.
Chromatic Valence Curves: Alternative Interpretation Derived by the Direct Matching Method
Authors: Ayama Miyoshi , Ikeda Mitsuo
Published: October 2006

The amount of red chromatic valence of the red-green opponent colors channel of the human visual system has been reported to be greatly reduced in short wavelengths when the hue-matching method is used to measure red valence instead of the more typical cancellation method. Receptive fields with a silent surround were postulated to explain the reduction, and it was emphasized that the reduced valence curve represented the true chromatic valence curve of the visual system. In the present studies the previous results are interpreted to be a direct consequence of the method and the particular matching stimuli used. It is shown that the reduction can be explained by the existing color-matching data without appealing to the silent surround hypothesis.
Queuine, a Modified Base Incorporated Posttranscriptionally into Eukaryotic Transfer RNA: Wide Distribution in Nature
Authors: Katze Jon R. , Basile Brenda , McCloskey James A.
Published: October 2006

Queuine, a modified base found in transfer RNA, appears to be a new dietary factor because (i) previous studies have shown that mice require it for the expression of queuine-containing transfer RNA's, but apparently do not synthesize it, and (ii) significant amounts of free queuine are present in common plant and animal food products.
Oculoparalytic Illusion: Visual-Field Dependent Spatial Mislocalizations by Humans Partially Paralyzed with Curare
Authors: Matin Leonard , Picoult Evan , Stevens John K. , Edwards McIver W. , Young David , MacArthur Rodger
Published: October 2006

In darkness, observers partially paralyzed with curare make large (> 20 degrees) gaze- and dosage-dependent errors in visually localizing eye-level-horizontal and median planes, in matching the location of a sound to a light, and in pointing at a light. In illuminated, structured visual fields visual localization and pointing are accurate but errors in auditory-to-visual matches remain. Defects in extraretinal eye position information are responsible for all errors. The influence of extraretinal eye position information on visual localization is suppressed by a structured visual field but is crucial both in darkness and for intersensory localization if visual capture is prevented.
The Anatomy of A-, B-, and Z-DNA
Authors: Dickerson Richard E. , Drew Horace R. , Conner Benjamin N. , Wing Richard M. , Fratini Albert V. , Kopka Mary L.
Published: October 2006

Recent advances in DNA synthesis methods have made it possible to carry out single-crystal x-ray analyses of double-stranded DNA molecules of predetermined sequence, with 4 to 12 base pairs. At least one example has been examined from each of the three known families of DNA helix: A, B, and Z. Each family has its own intrinsic restrictions on chain folding and structure. The observed solvent positions in these crystal structures have confirmed earlier fiber and solution measurements, and have led to proposals explaining the transitions from B to A and from B to Z helices. Prospects are improving for an understanding of the mode of bending of DNA in chromatin, and the way in which specific DNA sequences are recognized by drug molecules and repressor proteins.
Human Aldehyde Dehydrogenase: Mechanism of Inhibition of Disulfiram
Authors: Vallari Robert C. , Pietruszko Regina
Published: October 2006

Disulfiram labeled with carbon-14 reacts specifically with human liver aldehyde dehydrogenase E1 with loss of catalytic activity and no incorporation of label. Carbon-14-labeled diethyldithiocarbamate is formed and the number of enzyme sulfhydryl groups decreases from 34 to 30 during this process. Activity is recovered by 2-mercaptoethanol but not by glutathione, the physiological reducing agent.
Growth Hormone Stimulates Longitudinal Bone Growth Directly
Authors: Isaksson Olle G. P. , Jansson John-Olov , Gause Ingrid A. M.
Published: October 2006

Local administration of human growth hormone in vivo to the cartilage growth plate of the proximal tibia of hypophysectomized rats resulted in accelerated longitudinal bone growth. This finding suggests that growth hormone directly stimulates the cells in the growth plate, and does not support the theory that the increase in the plasma concentration of somatomedin that follows growth hormone administration is the cause of this stimulation.
Temperature-Dependent Sex Determination: Current Practices Threaten Conservation of Sea Turtles
Authors: Morreale Stephen J. , Ruiz Georgita J. , Spotila James R. , Standora Edward A.
Published: October 2006

Temperature determines the sex of hatchling green turtles (
Chelonia mydas
) produced from eggs incubated in a beach hatchery under different temperature regimes. Cold and cool nests (< 28°C) produced almost no females (0 to 10 percent) and warm, thermostable nests (> 29.5°C) produced almost all females (95 to 100 percent). A few intersex hatchlings were produced at lower temperatures. Since little concern is given to temperatures at which sea turtle eggs are incubated in artificial hatcheries, present conservation practices may be producing all male, all female, or even intersex hatchlings.
Lung Water Quantitation by Nuclear Magnetic Resonance Imaging
Authors: Hayes Cecil E. , Case Thomas A. , Ailion David C. , Morris Alan H. , Cutillo Antonio , Blackburn Celia W. , Durney Carl H. , Johnson Steven A.
Published: October 2006

Nuclear magnetic resonance imaging was used to determine quantitatively the water distribution of saline-filled and normal rat lungs in both isolated lung and in situ preparations. Regional lung edema was easily detected. Studies of an isolated lung fragment indicate an accuracy of better than 1 percent and images of H
2
O/D
2
O phantoms indicate an average error of 2.7 percent.
Diazepam Impairs Lateral Position Control in Highway Driving
Authors: O'Hanlon J. F. , Haak T. W. , Blaauw G. J. , Riemersma J. B.
Published: October 2006

Nine expert drivers operated an instrumented vehicle in tests over a highway at night after being treated with diazepam (5 and 10 milligrams), a placebo, and nothing. They reacted to 10 milligrams of diazepam with increased lateral position variability. Potentially dangerous impairment was inferred from the reactions of some subjects.
Rotating Shift Work Schedules That Disrupt Sleep Are Improved by Applying Circadian Principles
Authors: Czeisler Charles A. , Moore-Ede Martin C. , Coleman Richard M.
Published: October 2006

Workers on rotating shifts dislike those aspects of their work schedules that violate circadian sleep-wake cycle physiology. Work schedule satisfaction, subjective health estimates, personnel turnover, and worker productivity improve when schedules are introduced that are designed to incorporate circadian principles.
Reversal of the Stimulating Action of Hydrostatic Pressure on Striated Muscle
Authors: Cattell McKeen , Edwards Dayton J.
Published: October 2006

The usual augmenting action of pressure on the tension developed by striated muscle in response to a single stimulus changes to depression on fatiguing the muscle. On release of the pressure the tension of the single twitch again reaches the control value.

A similar reversal may be brought about by cooling the muscle, the change usually occurring at about 13°C. Below this temperature the depression is roughly proportional to the pressure. At about 1°C. the tension development may be completely inhibited by high pressure. The muscle responds normally upon release of the pressure, and upon warming pressure again causes augmentation of contraction.
Laboratory and Teaching Devices Made from Plaster of Paris
Authors: McLaughlin Alvah R.
Published: October 2006

A method has been described whereby models of septic tanks for teaching public health and oncometers for physiological demonstration and research may be constructed by employing a wire frame and covering it with plaster of Paris.

These models should prove especially useful to teachers in rural and suburban communities and to extension workers whose task it is to keep a vast number of our population informed as to the best measures of protecting their health.

These models may be rendered impervious to air and water by means of paraffin, varnish or brushing lacquer.
Familial Renal Cell Carcinoma with a 3;11 Chromosome Translocation Limited to Tumor Cells
Authors: Pathak S. , Strong L. C. , Ferrell R. E. , Trindade A.
Published: October 2006

Cytogenetic studies were performed on the direct chromosome preparations of the renal cell carcinoma cells and the cultured peripheral blood lymphocytes of a patient with familial renal cell carcinoma. The results revealed a specific, acquired translocation (3p;11p) present in the majority of metaphases of the tumor, indicating that the development of renal cell carcinoma is associated with a deletion in the proximal end of 3p. Renal cell carcinoma is thus the third example—the first two being retinoblastoma and Wilms' tumor—of a chromosomal deletion occurring germinally or somatically in association with a specific tumor. This finding adds further support to the existence of specific human cancer genes.
Neuronal Mapping: A Photooxidation Reaction Makes Lucifer Yellow Useful for Electron Microscopy
Authors: Maranto Anthony R.
Published: October 2006

Irradiating Lucifer yellow-filled neurons with intense blue light in the presence of 3,3′-diaminobenzidine produces an electron-opaque osmiophilic polymer within the injected cells. This technique is valuable when cobalt or horseradish peroxidase injections are difficult or when a second intracellular marker is needed to demonstrate neuronal contacts.
Quantitative Autoradiographic Mapping of Herpes Simplex Virus Encephalitis with a Radiolabeled Antiviral Drug
Authors: Saito Yutaka , Price Richard W. , Rottenberg David A. , Fox Jack J. , Su Tsann-Long , Watanabe Kyoichi A. , Philips Frederick S.
Published: October 2006

2′-Fluoro-5-methyl-1-β-D-arabinosyluracil (FMAU) labeled with carbon-14 was used to image herpes simplex virus type 1-infected regions of rat brain by quantitative autoradiography. FMAU is a potent antiviral pyrimidine nucleoside which is selectively phosphorylated by virus-coded thymidine kinase. When the labeled FMAU was administered 6 hours before the rats were killed, the selective uptake and concentration of the drug and its metabolites by infected cells (defined by immunoperoxidase staining of viral antigens) allowed quantitative definition and mapping of HSV-1-infected structures in autoradiograms of brain sections. These results show that quantitative autoradiography can be used to characterize the local metabolism of antiviral drugs by infected cells in vivo. They also suggest that the selective uptake of drugs that exploit viral thymidine kinase for their antiviral effect can, by appropriate labeling, be used in conjunction with clinical neuroimaging techniques to define infected regions of human brain, thereby providing a new approach to the diagnosis of herpes encephalitis in man.
Fluorescence Microscopy: Reduced Photobleaching of Rhodamine and Fluorescein Protein Conjugates by
n
-Propyl Gallate
Authors: Giloh Haim , Sedat John W.
Published: October 2006

n
-Propyl gallate (0.1 to 0.25 molar, in glycerol) reduces by a factor of 10 the rate of fading of fluorescence of cell structures labeled with tetramethylrhodamine or fluorescein-conjugated antibodies. Hence, prolonged photographic exposure of immunofluorescently labeled cells in the fluorescence microscope yields images with increased sensitivity, making feasible multiple data collection, as with serial optical sectioning.
Transmethylation of Phosphatidylethanolamine: An Initial Event in Embryonic Chicken Lens Fiber Cell Differentiation
Authors: Zelenka Peggy S. , Beebe David C. , Feagans Douglas E.
Published: October 2006

Agents that induce differentiation of lens epithelial cells into lens fiber cells in vitro transiently stimulate the transmethylation of phosphatidylethanolamine. Inhibition of transmethylation by 3-deazaadenosine results in a corresponding inhibition of the cell elongation that characterizes lens fiber formation, suggesting that phospholipid methylation plays an essential role in the differentiation of these cells.
Retinogeniculate Terminations in Cats: Morphological Differences Between X and Y Cell Axons
Authors: Sur Mriganka , Sherman S. Murray
Published: October 2006

We injected horseradish peroxidase into single, physiologically identified, optic tract axons of X and Y cells in cats and studied their termination patterns in the lateral geniculate nucleus. All X cell axons innervate lamina A or A1 in narrow zones, and some sparsely innervate the medial interlaminar nucleus. All Y cell axons have broad terminal zones in laminae A and C (from the contralateral retina) or lamina A1 (if ipsilateral), and most innervate the medial interlaminar nucleus densely.
Aphasia and Speech Organization in Children
Authors: Carter Randy L. , Hohenegger Miles K. , Satz Paul
Published: October 2006

A long-standing controversy concerns whether lateralized cerebral specialization for speech and language is present at the time of language origins (developmental invariance) or whether it gradually develops from initial bilaterality (developmental progression). This controversy is complicated by conflicting reports of the incidence of childhood aphasia. The discrepancies are largely due to one early study. When methods for estimating speech organization distributions are applied to later studies, the developmental invariance position is supported.
Odor Quality: Semantically Generated Multidimensional Profiles Are Stable
Authors: Dravnieks Andrew
Published: October 2006

Odors of ten compounds were characterized by approximately 150 subjects who used a list of 146 descriptors. Duplicate profiles correlated highly (P < .001) and consistently higher than profiles of different odors. Profiles also agreed with those obtained previously. Thus, profiles based on combined responses of many subjects are stable constructs.