bluuebunny/crossref_metadata_2025 huggingface dataset:
Picrotoxin Convulsions Involve Synaptic and Nonsynaptic Mechanisms on Cultured Mouse Spinal Neurons
Authors: Barker Jeffery L. , MacDonald John F.
Published: October 2006

The cellular mechanisms underlying picrotoxin-induced convulsive activity were studied by using mouse spinal neurons growing in tissue culture. Picrotoxin-induced convulsive activity in most but not all of the cells studied. The activity could be inverted by polarizing to positive potentials and eliminated either by decreasing the ratio of calcium to magnesium or by applying tetrodotoxin. When applied locally to individual cells, picrotoxin lowered spike threshold and induced spontaneous firing in some but not all cells tested. The results suggest that picrotoxin-induced convulsive activity involves rapidly summating synaptic activity which may be evoked by high-frequency repetitive firing.
Methylphenidate and Hyperactivity: Effects on Teacher Behaviors
Authors: Whalen Carol K. , Henker Barbara , Dotemoto Sharon
Published: October 2006

Teacher interactions with hyperactive and comparison boys were observed during classroom activities. A double-blind, methylphenidate-placebo cross-over design was used within the hyperactive group. With no knowledge of any child's diagnosis or drug status, the teacher was more intense and controlling toward hyperactive boys taking placebo than toward either medicated hyperactive boys or comparison boys; her behavior did not differ toward the latter two groups. Discussion focused on the need to consider the broad social ramifications of pharmacologic treatment programs.
Pharmaceuticals: Their Role in Developing Societies
Authors: McDermott Walsh
Published: October 2006

The appropriate technology for control of diseases of economically underdeveloped countries happens to be mainly that applicable to groups as a whole; whereas that effective for most diseases of industrialized societies must be individually delivered. The latter area is where the pharmaceutical industry has scored its greatest triumphs, yet most of this technology does not fit the major disease problems as they now exist in the developing countries. The argument is presented that in order for the U.S. industry to do more in the developing countries, the most needed invention is not a new drug, but a new system for drug development—a new R & D system tailored specially to both the financial and the biologic needs of the problem.
Plasminogen Is Synthesized by Primary Cultures of Rat Hepatocytes
Authors: Bohmfalk John F. , Fuller Gerald M.
Published: October 2006

The accumulation of rat plasminogen in the medium of primary monolayer cultures of adult parenchymal hepatocytes was detected with a quantitative immunological assay. These primary cultures synthesized and secreted both circulating isozymic forms of plasminogen at rates sufficient to account for the majority of the in vivo plasminogen turnover.
Neuronal Loss in Hippocampus Induced by Prolonged Ethanol Consumption in Rats
Authors: Walker Don W. , Barnes David E. , Zornetzer Steven F. , Hunter Bruce E. , Kubanis Patricia
Published: October 2006

Quantitative neurohistological techniques were used to examine the hippocampal complex of laboratory rats maintained on ethanol-containing or control diets for 5 months followed by a 2-month alcohol-free period. Chronic ethanol consumption resulted in a significant loss of hippocampal pyramidal and dentate gyrus granule cells. This study provides direct evidence that long-term ethanol consumption, in the absence of malnutrition, produces neuronal loss in the central nervous system.
Phase-Sensitive Midbrain Neurons in
Eigenmannia
: Neural Correlates of the Jamming Avoidance Response
Authors: Bastian Joseph , Heiligenberg Walter
Published: October 2006

Neurons in the torus semicircularis of the weakly electric fish
Eigenmannia
encode phase differences between sinusoidal electrical stimuli received in different body regions. These fish normally experience time-varying phase differences when the electric organ discharge fields of two or more individuals overlap. These phase differences supply information necessary for the animal's jamming avoidance behavior.
Factors Influencing the Inhibitory Effect of Selenium on Mice Inoculated with Ehrlich Ascites Tumor Cells
Authors: Greeder Glenn A. , Milner J. A.
Published: October 2006

Selenium, administered to mice with Ehrlich ascites tumors, effectively limited tumor growth. The response was dependent on the chemical form and dose of selenium administered. At the doses administered, there were no detectable adverse effects to the host.
Ultrasonic Diagnostic Instruments
Authors: Popp Richard L. , Macovski Albert
Published: October 2006

The underlying physical principles and current limitations of diagnostic ultrasonic instruments are reviewed. Recently developed ultrasonic imaging devices using pulsed-reflected ultrasound are discussed in detail. These instruments transmit short trains of 1.5- to 10-megahertz sound. Echoes reflected from tissue are converted to electrical signals, which are presented on a display device to outline the contour of tissues and organs within the body. The physical resolution of the system is dependent on several design factors in addition to the transmitted sound frequencies. A resolution volume of approximately 1.5 by 3 by 4 millimeters is achieved optimally with commercially available systems operating at 2.25 megahertz. The various instrument designs are described in the context of clinical usage. Because the sound is diffracted, refracted, and reflected, the imaging considerations are different from those of x-ray imaging. Diagnostic devices based on the Doppler principle are distinguished from pulsed-reflected ultrasonic instruments.
Three-Dimensional Imaging of Heart, Lungs, and Circulation
Authors: Ritman E. L. , Kinsey J. H. , Robb R. A. , Gilbert B. K. , Harris L. D. , Wood E. H.
Published: October 2006

A new imaging device, the dynamic spatial reconstructor (DSR), is described. It differs from commercially available computed tomography scanners in several ways. It images a volume rather than a slice; it images the volume in stop-action to minimize blurring due to motion; and it repeats the scan 60 times per second so that the functional movements of heart muscle and lung tissue and the distribution of roentgen contrast medium in blood can be quantitated in any portion of the body, especially in the heart, great vessels, and lungs. The system is under evaluation as a research tool for physiologic and, ultimately, clinical investigations.
Differential Development of Brainstem Potentials in Healthy and High-Risk Infants
Authors: Salamy A. , Mendelson T. , Tooley W. H. , Chaplin E. R.
Published: October 2006

Maturation along the brainstem acoustic pathway, as well as the integrity of these structures, has been shown to be reflected in brainstem evoked potential recordings. Trajectories formed from repeated sequential measurements of several brainstem response variables reveal distinct developmental curves for healthy and high-risk infants. Longitudinal analysis offers a means of determining temporary or permanent maturational effects on the central nervous system in early life.
Functional Development of Grafted Vasopressin Neurons
Authors: Gash Don , Sladek John R. , Sladek Celia D.
Published: October 2006

Vasopressin neurons, transplanted from normal rat fetuses into the third ventricle of adult Brattleboro rats, alleviate the polydipsia and polyuria of the hosts. Determination of the antidiuretic activity of grafted neurons in hosts with congenital diabetes insipidus provides a convenient model for analyzing the development, plasticity, and function of transplanted central nervous system neurons in mammals.
Tyrosine Administration Decreases Vulnerability to Ventricular Fibrillation in the Normal Canine Heart
Authors: Scott Neal A. , DeSilva Regis A. , Lown Bernard , Wurtman Richard J.
Published: October 2006

Intravenous infusion of tyrosine (1, 2, or 4 milligrams per kilogram) for 20 to 30 minutes caused dose-dependent increases in the ventricular fibrillation threshold in normal dogs. Administration of valine, a neutral amino acid that competes with tyrosine for uptake at the blood-brain barrier, in a dose equimolar to the most effective dose of tyrosine, slightly decreased the ventricular fibrillation threshold when given alone and significantly blocked elevation of the ventricular fibrillation threshold after tyrosine infusion. Hence, tyrosine, presumably acting in the central nervous system, can protect against certain ventricular arrhythmias.
Dialysis in Schizophrenia: A Double-Blind Evaluation
Authors: Schulz S. C. , van Kammen D. P. , Balow J. E. , Flye M. W. , Bunney W. E.
Published: October 2006

Eight chronic schizophrenia patients completed a research program consisting of ten weekly sessions of active hemodialysis and ten weekly sessions of sham dialysis in a double-blind design. Previous reports of therapeutic efficacy were not substantiated. None of the patients improved during active dialysis; four patients worsened.
The National Science Foundation Looks to the Future
Authors: Slaughter John B.
Published: October 2006

Great advances have been made in fundamental scientific research in recent years. The new knowledge gathered, in addition to deepening our understanding of the physical universe, contributes a range of abilities and opportunities to society that would not otherwise be available. Much research that may be called applied because it addresses needs of society is quite fundamental in character, and support of such research at the National Science Foundation is to be handled in tandem by the research directorates. Other areas that require a refocusing of support are engineering science and education, at all levels, in science and engineering. Increasing our strength in these areas is essential to achieve our national economic, social, and political goals. Steps are being taken by the National Science Foundation to make its structure better able to deal with engineering and applied research and to provide greater mutual reinforcement between applied and basic research.
Research in EPA: A Congressional Point of View
Authors: Brown George E. , Byerly Radford
Published: October 2006

From lessons learned in several years of overseeing the research programs of the Environmental Protection Agency, the authors conclude that the agency should give more support to the accumulation of the scientific "intellectual capital" needed for managing the environment in the long term.
Potent Contact Allergen in the Rubber Plant Guayule (
Parthenium argentatum
)
Authors: Rodriguez Eloy , Reynolds Gary W. , Thompson James A.
Published: October 2006

Chemical and dermatotoxicological investigations of the natural and processed resin of the Mexican rubber plant, guayule (
Parthenium argentatum
), has established the presence of a sesquiterpene cinnamic acid ester (guayulin A) that is a potent elicitor of allergic contact dermatitis in experimental animals. The guayule contact allergen is comparable to the poison ivy skin allergens as an elicitor of dermatitis in sensitized guinea pigs.
Cholecystokinin in the Brains of Obese and Nonobese Mice
Authors: Straus Eugene , Yalow Rosalyn S.
Published: October 2006

Extracts of the cerebral cortex of genetically obese (
ob
/
ob
) mice with hyperphagia contain 0.05 ± 0.02 microgram (mean ± standard error) of cholecystokinin octapeptide equivalent per gram of wet weight compared to 0.15 ± 0.01 microgram per gram for their nonobese littermates and 0.20 ± 0.01 microgram per gram for normal LAF
1
mice. These findings are suggestive of a causal relation between the diminished brain immunoreactive cholecystokinin content and the unrestrained appetite of the obese mice.
Cerebral Glucose Utilization: Local Changes During and After Recovery from Spreading Cortical Depression
Authors: Shinohara Mami , Dollinger Beth , Brown Gwen , Rapoport Stanley , Sokoloff Louis
Published: October 2006

Cerebral glucose utilization is markedly increased in most areas of the cerebral cortex and reduced in many subcortical structures during spreading cortical depression. During recovery, cortical glucose utilization is still elevated, but the increased metabolic activity is distributed in columns running perpendicularly through the cortex.
Thalamic Projections to Layer I of Striate Cortex Shown by Retrograde Transport of Horseradish Peroxidase
Authors: Carey Russell G. , Fitzpatrick David , Diamond Irving T.
Published: October 2006

The diffusion of horseradish peroxidase was restricted to layers I and II of the striate cortex in "
Tupaia glis
and
Galago senegalensis
. In the lateral geniculate body of
Tupaia
labeled cells were found only in layer 3; some labeled cells were also found in the lateral nucleus. In
Galago
labeled cells were found only in layers 4 and 5 of the lateral geniculate body; a band of cells was also found in the pulvinar nucleus. These results support the distinction between two overlapping thalamic systems, a layer I and a layer IV system.
Osmotic Shock Prevents Nuclear Exchange and Produces Whole-Genome Homozygotes in Conjugating
Tetrahymena
Authors: Orias Eduardo , Hamilton Eileen P. , Flacks Miriam
Published: October 2006

Exposure of conjugating
Tetrahymena
to a hyperosmotic shock blocks the exchange of gametic nuclei and produces self-fertilized exconjugants that are homozygous for their whole genome. Cells are sensitive to this induction during a brief period after meiosis. The high efficiency of the treatment and the fertility of the progeny make this a useful method for the isolation of induced recessive mutations and enhances the value of
Tetrahymena
as an animal-cell model system in which genetic dissection is practical. The sharp peak of sensitivity is useful in the study of those cellular mechanisms responsible for the independent handling of several functionally distinct nuclei during conjugation.
Skn-1a and Skn-1i: Two Functionally Distinct Oct-2-Related Factors Expressed in Epidermis
Authors: Andersen Bogi , Schonemann Marcus D. , Flynn Sarah E. , Pearse Richard V. , Singh Harinder , Rosenfeld Michael G.
Published: October 2006

Two forms of a member of the POU domain family of transcriptional regulators, highly related to Oct-2, are selectively expressed in terminally differentiating epidermis and hair follicles. One form, referred to as Skn-1i, contains an amino-terminal domain that inhibits DNA binding and can inhibit transactivation by Oct-1. A second form, Skn-1a, contains an alternative amino terminus and serves to activate cytokeratin 10 (K10) gene expression. The pattern of expression of the
Skn-1a/i
gene products and the effect of the alternative products on the expression of other genes suggest that these factors serve regulatory functions with respect to epidermal development.
Inhibition of Viral Replication by Interferon-γ-Induced Nitric Oxide Synthase
Authors: Karupiah Gunasegaran , Xie Qiao-wen , Buller R. Mark L. , Nathan Carl , Duarte Cornelio , MacMicking John D.
Published: October 2006

Interferons (IFNs) induce antiviral activity in many cell types. The ability of IFN-γ to inhibit replication of ectromelia, vaccinia, and herpes simplex-1 viruses in mouse macrophages correlated with the cells' production of nitric oxide (NO). Viral replication was restored in IFN-γ-treated macrophages exposed to inhibitors of NO synthase. Conversely, epithelial cells with no detectable NO synthesis restricted viral replication when transfected with a complementary DNA encoding inducible NO synthase or treated with organic compounds that generate NO. In mice, an inhibitor of NO synthase converted resolving ectromelia virus infection into fulminant mousepox. Thus, induction of NO synthase can be necessary and sufficient for a substantial antiviral effect of IFN-γ.
Binding of L-Selectin to the Vascular Sialomucin CD34
Authors: Baumheter Susanne , Singer Mark S. , Henzel William , Hemmerich Stefan , Renz Mark , Rosen Steven D. , Lasky Laurence A.
Published: October 2006

The adhesive interactions between leukocyte L-selectin and the endothelium are involved in the migration of lymphocytes through peripheral lymph nodes and of neutrophils to sites of inflammation. A recombinant L-selectin stains high endothelial venules (HEVs) in lymph nodes and recognizes sulfated carbohydrates found on two endothelial glycoproteins, Sgp50 and Sgp90. Amino acid sequencing of purified Sgp90 revealed a protein core identical to that of CD34, a sialomucin expressed on hematopoietic stem cells and endothelium. A polyclonal antiserum to recombinant murine CD34 stains peripheral lymph node endothelium and recognizes Sgp90 that is functionally bound by L-selectin. Thus, an HEV glycoform of CD34 can function as a ligand for L-selectin.
Cytochrome P-450 and Drug Metabolism in
Trypanosoma cruzi
: Effects of Phenobarbital
Authors: Agosin M. , Naquira C. , Paulin J. , Capdevila J.
Published: October 2006

The epimastigotes of
Trypanosoma cruzi
hydroxylate drugs at substantial rates. The activity, which is of the mixed-function oxidase type, is increased by phenobarbital and is inhibited by CO, SKF 525-A, and metyrapone. The hydroxylation is paralleled by increases in free and membrane-bound ribosomes.
Nuclear and Mitochondrial DNA Replication During Zygote Formation and Maturation in Yeast
Authors: Sena E. , Welch J. , Fogel S.
Published: October 2006

Nuclear and mitochondrial DNA replication were monitored during the development of synchronous yeast zygotes. Purified first zygotic buds were also analyzed. Nuclear DNA replicated discontinuously but coincidently with bud initiation, while mitochondrial DNA replicated throughout the zygotic formation and maturation period. First zygotic buds contained the diploid level of both nuclear and mitochondrial DNA.
A Specific Population of Gonadotrophs Purified from Immature Female Rat Pituitary
Authors: Denef Carl , Hautekeete Emmy , Rubin Lee
Published: October 2006

When dispersed pituitary cells from 14-day-old female rats were sedimented in a bovine serum albumin gradient, a fraction was isolated which consisted of almost 90 percent of large cells that stained purple in the periodic acid-Schiff (PAS) reaction. Immunostaining indicated that over 85 percent of these PAS-purple cells were gonadotrophs containing both follicle stimulating and luteinizing hormone. Reproducible cell cultures could be obtained on poly-L-lysine coated dishes. As early as the second day in culture, the secretion of both follicle stimulating and luteinizing hormone was highly stimulated by luteinizing hormone-releasing hormone. The effect on FSH was as marked as that on LH. The data suggest that the isolated gonadotrophs are a specific functional subtype.
Cooperative Interactions Between the
Caenorhabditis elegans
Homeoproteins UNC-86 and MEC-3
Authors: Xue Ding , Tu Yuan , Chalfie Martin
Published: October 2006

The POU-type homeodomain protein UNC-86 and the LIM-type homeodomain protein MEC-3, which specify neuronal cell fate in the nematode
Caenorhabditis elegans
, bind cooperatively as a heterodimer to the
mec-3
promoter. Heterodimer formation increases DNA binding stability and, therefore, increases DNA binding specificity. The in vivo significance of this heterodimer formation in neuronal differentiation is suggested by (i) a loss-of-function
mec-3
mutation whose product in vitro binds DNA well but forms heterodimers with UNC-86 poorly and (ii) a
mec-3
mutation with wild-type function whose product binds DNA poorly but forms heterodimers well.
Characterization of a Presynaptic Glutamate Receptor
Authors: Smirnova Tania , Stinnakre Jacques , Mallet Jacques
Published: October 2006

Glutamate receptors mediate excitatory neurotransmission in the brain and are important in the formation of memory and in some neurodegenerative disorders. A complementary DNA clone that encoded a 33-kilodalton protein (GR33) was obtained by screening a library with an antibody generated against glutamate binding proteins. The sequence of GR33 is identical to that of the recently reported presynaptic protein syntaxin. When GR33 was expressed in
Xenopus
oocytes, it formed glutamate-activated ion channels that are pharmacologically similar to those of
N
-methyl-D-aspartate receptors but with different electrophysiological properties. Mutation of the leucine 278 residue in the single putative transmembrane segment of GR33 affects the properties of the channel. Thus, in vivo GR33 may be a presynaptic glutamate receptor.
Detection of an Antigen Related to Mason-Pfizer Virus in Malignant Human Breast Tumors
Authors: Yeh J. , Ahmed M. , Mayyasi S. A. , Alessi A. A.
Published: October 2006

An antigen related to the major structural protein (p27) of Mason-Pfizer monkey virus has been found in malignant human breast tumors by radioimmunoassays. This antigen was not detected in normal placental tissues or in tumors that were not of breast origin.
Effects of Long-Term Corn Consumption on Brain Serotonin and the Response to Electric Shock
Authors: Lytle Loy D. , Messing Rita B. , Fisher Laurel , Phebus Lee
Published: October 2006

Rats fed tryptophan-poor corn diets have reduced levels of brain serotonin and show increased responsiveness to electric shock. This diet-induced hyperalgesia can be reversed by feeding the animals diets with adequate amounts of tryptophan, or by systemic injections of the amino acid.
Activity of Nocturnal Primates: Influences of Twilight Zeitgebers and Weather
Authors: Kavanau J. Lee , Peters Charles R.
Published: October 2006

The time of onset of activity of bush babies (
Galago senegalensis
), slow lorises (
Nycticebus coucang
), and an owl monkey (
Aotus trivirgatus
) living in outdoor enclosures usually fell in certain illuminance ranges of dusk and kept pace with seasonal progressions of sunset time. Influences of cloud cover were variable, but excessive heat and cold were inhibitory. Accurate endogenous timekeeping and reliance on the most stable zeitgeber apparently maintain activities in synchrony with the rhythmically changing environment.
Interaction of Mammalian Splicing Factor SF3a with U2 snRNP and Relation of Its 60-kD Subunit to Yeast PRP9
Authors: Brosi Reto , Gröning Karsten , Behrens Sven-Erik , Lührmann Reinhard , Krämer Angela
Published: October 2006

In the assembly of a prespliceosome, U2 small nuclear ribonucleoprotein (snRNP) functions in pre-messenger RNA (mRNA) splicing together with splicing factors (SFs) 3a, SF3b, and several other proteins. The 17
S
but not the 12
S
form of U2 snRNP is active in splicing-complex formation. Here it is shown that the SF3a subunits correspond to three of the 17
S
U2 snRNP-specific polypeptides. SF3a interacts with U2 snRNP in the presence of SF3b to generate a structure similar to 17
S
U2 snRNP, which suggests a function for SF3a and SF3b in the incorporation of U2 snRNP into the spliceosome. Furthermore, the 60-kilodalton subunit of SF3a is related to the yeast splicing protein PRP9.
Correspondence Between a Mammalian Spliceosome Component and an Essential Yeast Splicing Factor
Authors: Bennett Maria , Reed Robin
Published: October 2006

None of the mammalian splicing factors that have been cloned corresponds to the yeast pre-messenger RNA splicing factors, the PRP proteins. Here, a generalizable strategy was used to isolate a complementary DNA encoding the mammalian spliceosome-associated protein (SAP) SAP 62. It is demonstrated that SAP 62 is the likely functional homolog of the yeast PRP11 protein. Both PRP11 and SAP 62 associate stably with the spliceosome, contain a single zinc finger, and display significant amino acid sequence similarity. Unlike PRP11, SAP 62 contains 22 proline-rich heptapeptide repeats at the carboxyl-terminus.
Detecting Subtle Sequence Signals: a Gibbs Sampling Strategy for Multiple Alignment
Authors: Lawrence Charles E. , Altschul Stephen F. , Boguski Mark S. , Liu Jun S. , Neuwald Andrew F. , Wootton John C.
Published: October 2006

A wealth of protein and DNA sequence data is being generated by genome projects and other sequencing efforts. A crucial barrier to deciphering these sequences and understanding the relations among them is the difficulty of detecting subtle local residue patterns common to multiple sequences. Such patterns frequently reflect similar molecular structures and biological properties. A mathematical definition of this "local multiple alignment" problem suitable for full computer automation has been used to develop a new and sensitive algorithm, based on the statistical method of iterative sampling. This algorithm finds an optimized local alignment model forNsequences inN-linear time, requiring only seconds on current workstations, and allows the simultaneous detection and optimization of multiple patterns and pattern repeats. The method is illustrated as applied to helix-turn-helix proteins, lipocalins, and prenyltransferases.
The Crystal Structure of Lysin, a Fertilization Protein
Authors: Shaw A. , McRee D. E. , Vacquier V. D. , Stout C. D.
Published: October 2006

Lysin, a protein from abalone sperm, creates a hole in the envelope of the egg, permitting the sperm to pass through the envelope and fuse with the egg. The structure of lysin, refined at 1.9 angstroms resolution, reveals an α-helical, amphipathic molecule. The surface of the protein exhibits three features: two tracks of basic residues that span the length of the molecule, a solvent-exposed cluster of aromatic and aliphatic amino acids, and an extended amino-terminal hypervariable domain that is species-specific. The structure suggests possible mechanisms of action.
Interleukin-2 Receptor γ Chain: a Functional Component of the Interleukin-7 Receptor
Authors: Noguchi Masayuki , Nakamura Yoshiaki , Russell Sarah M. , Ziegler Steven F. , Tsang Monica , Cao Xiqing , Leonard Warren J.
Published: October 2006

The interleukin-2 receptor γ chain (IL-2Rγ) is a necessary component of functional IL-2 receptors. IL-2Rγ mutations result in X-linked severe combined immunodeficiency (XSCID) in humans, a disease characterized by the presence of few or no T cells. In contrast, SCID patients with IL-2 deficiency and IL-2-deficient mice have normal numbers of T cells, suggesting that IL-2Rγ is part of more than one cytokine receptor. By using chemical cross-linking, IL-2Rγ was shown to be physically associated with the IL-7 receptor. The presence of IL-2Rγ augmented both IL-7 binding affinity and the efficiency of internalization of IL-7. These findings may help explain the defects of XSCID. Given its role in more than one cytokine receptor system, the common γ chain (gamma;
c
) is proposed as the designation for IL-2Rγ.
Suppression of the Temperature-Sensitive Phenotype of a Mutant of Reovirus Type 3
Authors: Ramig Robert F. , White Rosalyn M. , Fields Bernard N.
Published: October 2006

A revertant of a reovirus group A temperature-sensitive mutant was crossed with wild type. More than 50 percent of the progeny were temperature sensitive. In all of the temperature-sensitive progeny examined by recombination tests, the temperature-sensitive lesion was in group A. The results indicate that the revertant was phenotypically suppressed.
Blood Corpuscles and Blood Hemoglobins: A Possible Example of Coevolution
Authors: Snyder Gregory K.
Published: October 2006

A model which equates oxygen transport to hemoglobin concentration and molecular weight is used to demonstrate that high concentrations of hemoglobin will augment oxygen transport only if the molecular weight of the hemoglobin is low. The evolution of corpuscles is a necessary counterpart to having high concentrations of the low molecular weight hemoglobins; corpuscles prevent loss of the small molecules by way of excretory filters and prevent the development of exceedingly high plasma osmotic pressures.
Zinc Binding: A Difference Between Human and Bovine Milk
Authors: Eckhert Curtis D. , Sloan Martin V. , Duncan John R. , Hurley Lucille S.
Published: October 2006

Gel chromatography indicated that most of the zinc in cow's milk was associated with high-molecular-weight fractions, whereas zinc in human milk was associated with low-molecular-weight fractions. A species difference in zinc-binding ligands may explain why symptoms of the genetic disorder of zinc metabolism, acrodermatitis enteropathica, can be alleviated by feeding human but not cow's milk.
Amygdaloid Projections to Prefrontal and Motor Cortex
Authors: Llamas A. , Avendaño C. , Reinoso-Suárez F.
Published: October 2006

Direct projections from the amygdala to the entire frontal cortex were demonstrated in the cat using the retrograde transport of horseradish peroxidase. Injections throughout the prefrontal cortex labeled neurons in the ipsilateral basal magnocellular amygdaloid nucleus; injections in the premotor and motor cortices labeled neurons in the same nucleus plus a few cells in the anterior amygdaloid area.
Chemosensory Tracking of Scent Trails by the Planktonic Shrimp
Acetes sibogae australis
Authors: Hamner Peggy , Hamner W. M.
Published: October 2006

In the laboratory, planktonic shrimps (
Acetes sibogae
) precisely follow scent trails of food or paper soaked in meat extract, L-alanine, L-leucine, and L-methionine. In the ocean,
Acetes
may be able to follow scent trails as far as 20 meters to catch falling food. This demonstrates precise trail-following by pelagic animals.
The Distrust of Nuclear Power
Authors: Hohenemser Christoph , Kasperson Roger , Kates Robert
Published: October 2006

Society seems content to strike a more moderate or uncertain balance with other technologies than with nuclear power. This attitude is traced to the social history of nuclear power, the genuine uncertainty and complexity of safety issues, underestimation of the regulatory task, and the rancorous nature of the debate. Nuclear power is not just another problem of technology, of environment, or of health. It is unique in our time. To be more demanding of nuclear safety may be to apply a double standard, but not necessarily an irrational one.

Our best course appears to be to keep the nuclear option open, work toward the rapid resolution of problems such as waste disposal, but postpone recycling and the breeder reactor. Time is needed to resolve immediate problems such as transport and disposal of nuclear wastes; to come to terms with trans-scientific issues such as plutonium toxicity, sabotage, and weapons proliferation; and to evaluate long-term energy alternatives.
Cortical Potentials Associated with the Detection of Visual Events
Authors: Cooper R. , McCallum W. C. , Newton P. , Papakostopoulos D. , Pocock P. V. , Warren W. J.
Published: October 2006

A positive-going potential, which reaches a maximum at the vertex and midline parietal scalp electrodes, occurs in the human being when an infrequent, significant event occurs in a continuously observed visual display. It is not time locked to eye movements or operant response and appears to be generated when the observer recognizes an event that he has been instructed to detect.
Homeostasis During Hypoglycemia: Central Control of Adrenal Secretion and Peripheral Control of Feeding
Authors: Stricker Edward M. , Rowland Neil , Saller Charles F. , Friedman Mark I.
Published: October 2006

Intravenous infusions of mannose or β-hydroxybutyrate, metabolic fuels which can be oxidized by brain, abolished adrenal discharge of epinephrine in rats during insulin-induced hypoglycemia, whereas infusion of fructose, a sugar which does not cross the blood-brain barrier, did not. In contrast, increased feeding behavior during hypoglycemia was prevented both by the sugars and by β-hydroxybutyrate. Thus, while the sympathetic response during marked hypoglycemia may have been initiated by alterations in cerebral metabolism, the feeding response evidently was not, and a decrease in the utilization of glucose per se does not appear to be the critical stimulus in either case.
Clones of Individual Repetitive Sequences from Sea Urchin DNA Constructed with Synthetic Eco RI Sites
Authors: Scheller Richard H. , Thomas Terry L. , Lee Amy S. , Klein William H. , Niles Walter D. , Britten Roy J. , Davidson Eric H.
Published: October 2006

Interspersed repetitive sequences were isolated from sea urchin DNA by renaturing to low C
0
t followed by treatment with nuclease SI. Synthetic Eco RI sites were ligated onto the repetitive sequence elements, which were then inserted at the Eco RI site of plasmid RSF2124 and cloned. The repetitive sequences can be excised from the plasmid with Eco RI for further study.
Antischizophrenic Drugs: Chronic Treatment Elevates Dopamine Receptor Binding in Brain
Authors: Burt David R. , Creese Ian , Snyder Solomon H.
Published: October 2006

Chronic treatment of rats with the neuroleptic drugs haloperidol, fluphenazine, and reserpine elicits a 20 to 25 percent increase in striatal dopamine receptor binding assayed with [
3
H]haloperidol. This increase in receptor sites may account for behavioral supersensitivity to dopamine receptor stimulants in such animals and for tardive dyskinesia in patients treated with these drugs.
Regulation of the Ets-Related Transcription Factor Elf-1 by Binding to the Retinoblastoma Protein
Authors: Wang Chung-Yih , Petryniak Bronislawa , Thompson Craig B. , Kaelin William G. , Leiden Jeffrey M.
Published: October 2006

The retinoblastoma gene product (Rb) is a nuclear phosphoprotein that regulates cell cycle progression. Elf-1 is a lymphoid-specific Ets transcription factor that regulates inducible gene expression during T cell activation. In this report, it is demonstrated that Elf-1 contains a sequence motif that is highly related to the Rb binding sites of several viral oncoproteins and binds to the pocket region of Rb both in vitro and in vivo. Elf-1 binds exclusively to the underphosphorylated form of Rb and fails to bind to Rb mutants derived from patients with retinoblastoma. Co-immunoprecipitation experiments demonstrated an association between Elf-1 and Rb in resting normal human T cells. After T cell activation, the phosphorylation of Rb results in the release of Elf-1, which is correlated temporally with the activation of Elf-1-mediated transcription. Overexpression of a phosphorylation-defective form of Rb inhibited Elf-1-dependent transcription during T cell activation. These results demonstrate that Rb interacts specifically with a lineage-restricted Ets transcription factor. This regulated interaction may be important for the coordination of lineage-specific effector functions such as lymphokine production with cell cycle progression in activated T cells.
Major Innervation of Newborn Rat Cortex by Monoaminergic Neurons
Authors: Coyle Joseph T. , Molliver Mark E.
Published: October 2006

A major monoaminergic innervation in infant rat neocortex, predominantly in layer IV, has been demonstrated by ultrastructural and biochemical studies after the administration of exogenous catecholamine precursors and congeners. One-third of all cortical synapses have an uptake-storage mechanism for catecholamines. In newborn cortex, the storage capacity for catecholamines is tenfold greater than the endogenous levels, and the uptake-storage mechanism matures earlier than the ability to synthesize neurotransmitter.
Endothelial Damage and Thrombocyte Adhesion in Pigeon Atherosclerosis
Authors: Lewis Jon C. , Kottke Bruce A.
Published: October 2006

Scanning electron microscopy studies of spontaneously occurring atherosclerosis in pigeons reveal dramatic alterations in endothelial integrity. An irregular endothelium at the intimal cushion region of 5-week-old birds gives rise to extensive areas of pitted endothelium and subendothelial exposure. Thrombocytes, thrombocyte aggregates, and leukocytes are associated with the developing lesion.
Simultaneous Production of Q and R Bands After Staining with Chromomycin A
3
or Olivomycin
Authors: Prantera Giorgio , Bonaccorsi Silvia , Pimpinelli Sergio
Published: October 2006

Human and mouse chromosomes, stained with either chromomycin A
3
or olivomycin, which bind preferentially to G ⋅ C-rich DNA (where G is guanosine and C is cytosine), exhibit a Q or a reverse banding pattern, depending on the wavelength used for excitation. The two complementary banding patterns can be observed in the same metaphase simply by changing the combination of excitation filters. These data suggest, therefore, that in addition to base composition, other factors are involved in the production of chromosome banding by chromomycin A
3
and olivomycin.
Stereopsis in the Falcon
Authors: Fox Robert , Lehmkuhle Stephen W. , Bush Robert C.
Published: October 2006

Stereoscopic depth perception is demonstrated in the falcon, a nonmammalian with binocular vision. This result complements recent physiological evidence for binocular interaction in the bird visual system, and suggests that stereopsis may be a general attribute of vertebrate vision and not an exclusive product of mammalian evolution.
Homosexual Rape and Sexual Selection in Acanthocephalan Worms
Authors: Abele Lawrence G. , Gilchrist Sandra
Published: October 2006

Acanthocephalan males have cement glands associated with the vas deferens, secretions from which seal the female vagina with a cap after copulation and so prevent subsequent insemination. Homosexual rape results in the male victim having the genital region sealed off with cement and effectively removed from the reproductive population. Sperm and cement are transferred to females during copulation, but apparently only cement is transferred to males during homosexual rape. Acanthocephalans conform to a parental investment model, and we interpret the evolution of the cement gland and sexual behavior as the result of sexual selection.
Hypoxanthine Phosphoribosyltransferase: Two-Dimensional Gels from Normal and Lesch-Nyhan Hemolyzates
Authors: Ghangas Gurdev S. , Milman Gregory
Published: October 2006

Immunoprecipitated hypoxanthine phosphoribosyltransferase (HPRT) from hemolyzates displays two major spots after two-dimensional polyacrylamide gel electrophoresis. HeLa cells or human lymphoblasts display only a single HPRT spot located at the same position as the most basic of the hemolyzate HPRT spots. This suggests that the most basic spot is the form initially synthesized, and the more acidic hemolyzate HPRT spot (a pseudoisozyme) is probably derived from the first by an age-related modification (for example, deamidation). The HPRT pattern of the hemolyzate from a Lesch-Nyhan patient was shifted to a more basic isoelectric
p
H, implying the mutation of a structural gene.
A Critical Period for Acoustic Trauma in the Hamster and Its Relation to Cochlear Development
Authors: Bock Gregory R. , Saunders James C.
Published: October 2006

Young hamsters pass through a developmental stage during which they are unusually susceptible to acoustic trauma. This sensitive period occurs after apparent structural and functional maturation of the ear and appears to be dependent on unidentified developmental changes within the cochlea.
Hydrodynamic Evidence in Support of Spacer Regions in Chromatin
Authors: Schmitz Kenneth S. , Ramsay Shaw Barbara
Published: October 2006

Quasi-elastic light scattering and sedimentation velocity methods were used to study the hydrodynamic properties of purified dimer subunits obtained from partial digestion of chicken erythrocyte chromatin with staphylococcal nuclease. The experimental value of 1.87 ± 0.08 × 10
-7
gram per second for the friction factor of these dimer subunits in low ionic strength buffer cannot be reasonably interpreted in terms of a contiguous sphere model. Analysis by means of an equivalent dimer method suggests that the spacer region accounts for a maximum of 19 percent of the friction properties of the dimer.
Interferon: An Inducer of Macrophage Activation by Polyanions
Authors: Schultz Richard M. , Papamatheakis Joseph D. , Chirigos Michael A.
Published: October 2006

Purified mouse fibroblast interferon (IF) directly rendered resting macrophages tumoricidal. The physicochemical properties and species specificity of the stimulatory agent fall within the present definition of IF. Since a number of polyanions induce macrophage IF, the antitumor and antimicrobial activities may result from the ability of newly released IF to modify macrophage activity.
Ovarian Hormone: Lack of Effect on Reproductive Structures of Female Asian Musk Shrews
Authors: Dryden G. L. , Anderson J. N.
Published: October 2006

Uterine and vaginal weights and histologies are not altered by ovariectomy or estrogen treatment in the Asian musk shrew (
Suncus murinus
). In addition, ovariectomized shrews mate. Thus, the role of ovarian hormones in the control of the reproductive status of this species does not conform to the accepted mammalian pattern.
Loss of Y-Cells in the Lateral Geniculate Nucleus of Monocularly Deprived Tree Shrews
Authors: Norton Thomas T. , Casagrande Vivien A. , Sherman S. Murray
Published: October 2006

In tree shrews (
Tupaia glis
) reared with one eye closed, Y-cells were almost entirely absent in the binocular segment of the lateral geniculate laminae receiving input from the deprived eye. Y-cells were found in the monocular segment of these laminae, and in the binocular segment of the laminae with input from the normal eye. X-cells were present in both the deprived and normal laminae and appeared unaffected by the deprivation. A number of abnormal cells were also found, and these were located primarily in the binocular segment where Y-cells were absent.
Quantitation of Dimethylnitrosamine in the Whole Mouse After Biosynthesis in Vivo from Trace Levels of Precursors
Authors: Rounbehler D. P. , Ross R. , Fine D. H. , Iqbal Z. M. , Epstein S. S.
Published: October 2006

A simple and highly sensitive procedure is described for the recovery and quantitative identification of nanogram quantities of preformed
N
-nitroso compounds in the whole mouse. This procedure has also been applied to the quantitation of
N
-nitroso compounds after they have been biosynthesized from trace amounts of precursors. The whole animal is frozen in liquid nitrogen and homogenized to a frozen powder; the powder is then extracted and analyzed by a thermal energy analyzer interfaced to a gas-liquid and a high-pressure liquid chromatograph.
The Prime Meridian of Mars and the Longitudes of the Viking Landers
Authors: Davies Merton E
Published: October 2006

A new planetwide control net of Mars has been computed by a single large-block analytical triangulation derived from 17,224 measurements of 3,037 control points on 928 Mariner 9 pictures. The computation incorporated the new Viking-determined direction of the spin axis and rotation rate of Mars. The angle V, measured from the vernal equinox to the prime meridian (areocentric right ascension) of Mars, was determined to be V = 148.368° + 350.891986° (JD - 2433282.5), where JD refers to the Julian date. The prime meridian of Mars passes through the center of the small crater Airy-O. The longitudes of the Viking landers are λ
1
= 47.82° ± 0.1° and λ
2
= 225.59° ± 0.1° .
Transplantable Pancreatic Carcinoma of the Rat
Authors: Reddy J.K. , Rao M. S.
Published: October 2006

Pancreatic carcinoma, which developed in a male Fischer 344 rat fed 0.1 percent nafenopin for 20 months, is being successfully transplanted into weanling rats. The tumor cells contain variable numbers of zymogen granules, and the endoplasmic reticulum and the Golgi apparatus appear prominent. This transplantable tumor, which displays substantial amylase and lipase activity, should serve as a useful model system for immuno- and chemotherapeutic experiments, as well as for the study of synthesis, storage, and release of zymogen proteins in neoplastic cells.
Pathways of Medical Progress
Authors: Wiggers Carl J.
Published: October 2006

During the three decades that have passed, medical science has ascended to a high plateau of achievement. The climb has involved several pathways; among them: (1) the physiological approach toward disease as experiments which nature performs on organisms, (2) the more intelligent interpretation of the functional reactions of the body in disease in accordance with latest discoveries in physiology, (3) the supplementation of observable phenomena through use of laboratory instruments, (4) the assumption of active investigation both on patients and experimental animals by clinicians themselves, (5) the shuttling of problems between clinical and experimental laboratories and (6) correlated research in clinical and physiological departments.

As we look down from the heights we have reached, we have reason to be pleased with our progress; but when we look ahead we become aware that there are still high mountain ranges to be climbed. We realize that their ascent can not be accomplished by employing merely the methods, equipment and strategy that have proved successful so far; we must improve the application of principles that are old and well established, and evolve others that are new. Above all, we from laboratories and clinics must join hands to help each other climb; and through correlated teamwork overcome the great obstacles that jealous nature places in our way.

I have ventured to suggest a few directions which such mutual help may take. They include (1) means by which new fundamental discoveries can be utilized more quickly by clinicians and practitioners of medicine; (2) plans by which younger clinical investigators can be given approximately the same opportunity for training in research technique as their colleagues entering experimental sciences; (3) pleas that the shuttling of problems between hospitals and laboratories of fundamental science may continue in order that the ultimate significance of clinical results may be better understood and that the applicability of fundamental discoveries to nature's experiments may be tested; (4) judicious combination of talents of laboratory and clinical workers, whenever this leads to greater economy of effort and does not infringe upon the primary duties of each participant to his calling.

The spirit of correlation which is involved in all these plans of advance is a silent force which grows not only through mutual interest in each other's problems but also through frank respectful criticism of each other's trends. With such a spirit of correlated effort science marches on.
Elastase Release from Human Alveolar Macrophages: Comparison Between Smokers and Nonsmokers
Authors: Rodriguez Rafael J. , White Richard R. , Senior Robert M. , Levine Edith A.
Published: October 2006

Alveolar macrophages from smokers, in contrast to those of nonsmokers, release elastase into serum-free culture medium. Since enzymes that digest elastin produce pulmonary emphysema in experimental animals, release of elastase by alveolar macrophages from smokers suggests that these cells are important in the pathogenesis of emphysema of smokers.
Interdependence of the Nigrostriatal Dopaminergic Systems on the Two Sides of the Brain in the Cat
Authors: Nieoullon André , Chéramy André , Glowinski Jacques
Published: October 2006

The release of [
3
H]dopamine in vivo was estimated in the left and right caudate nuclei of the cat during the continuous superfusion of the two structures with L-[3,5-
3
H]tyrosine by means of two "push-pull" cannulas. A lesion made in the left substantia nigra interrupted the release of [
3
H]dopamine in the ipsilateral caudate nucleus and was associated with a simultaneous increase in the release of [
3
H]dopamine on the contralateral side. The release of [
3
H]dopamine also decreased in the left caudate nucleus and increased in the right structure when dopamine was applied to the left substantia nigra which reduces the activity of the left dopaminergic pathway. A total of 120 estimations of the spontaneous release of [
3
H]dopamine were made simultaneously in the left and right caudate nuclei during periods characterized by a stable physiological state of the animals, and 76 percent of the estimations showed that an increase in the release of [
3
H]dopamine on one side corresponded to a decrease in the release of [
3
H]dopamine on the other side, and vice versa. These results demonstrate a close relation between the two nigrostriatal dopaminergic systems.