bluuebunny/crossref_metadata_2025 huggingface dataset:
The Adenovirus Major Late Transcription Factor Activates the Rat γ-Fibrinogen Promoter
Authors: Chodosh Lewis A. , Carthew Richard W. , Morgan John G. , Crabtree Gerald R. , Sharp Phillip A.
Published: October 2006

The major late transcription factor (MLTF) is a 46-kilodalton polypeptide that specifically binds to and activates transcription from the major late promoter of adenovirus. The presence of this promoter-specific transcription factor in uninfected HeLa cell extracts suggests that MLTF is also involved in the transcription of cellular genes. This report demonstrates that MLTF specifically stimulates transcription of the rat γ-fibrinogen gene through a high-affinity binding site. Stimulation of transcription by MLTF was not dependent on the exact position of the MLTF binding site with respect either to the transcription initiation site or to adjacent promoter elements. These results suggest that one of the cellular functions of MLTF is to control γ-fibrinogen gene expression.
Determination of Anteroposterior Polarity in
Drosophila
Authors: Nüsslein-Volhard Christiane , Frohnhöfer Hans Georg , Lehmann Ruth
Published: October 2006

The principles of pattern formation in embryogenesis can be studied in
Drosophila
by means of a powerful combination of genetic and transplantation experiments. The segmented pattern of the
Drosophila
embryo is organized by two activities localized at the anterior and posterior egg poles. Both activities exert inducing and polarizing effects on the pattern when transplanted to other egg regions. A small set of maternal genes have been identified that are required for these activities. Mutants in these genes lack either the anterior or posterior part of the segmented pattern. The unsegmented terminal embryonic regions require a third class of genes and form independently of the anterior and posterior centers.
Pattern Recognition Used to Investigate Multivariate Data in Analytical Chemistry
Authors: Jurs Peter C.
Published: October 2006

Pattern recognition and allied multivariate methods provide an approach to the interpretation of the multivariate data often encountered in analytical chemistry. Widely used methods include mapping and display, discriminant development, clustering, and modeling. Each has been applied to a variety of chemical problems, and examples are given. The results of two recent studies are shown, a classification of subjects as normal or cystic fibrosis heterozygotes and simulation of chemical shifts of carbon-13 nuclear magnetic resonance spectra by linear model equations.
Binding ofcis- andtrans-Dichlorodiammineplatinum(II) to DNA: Evidence for Unwinding and Shortening of the Double Helix
Authors: Cohen Gary L. , Bauer William R. , Barton Jacqueline K. , Lippard Stephen J.
Published: October 2006

The antitumor drugcis-dichlorodiammineplatinum(II) (cis-DDP) and the inactive trans isomer bind and produce cooperative changes in closed and nicked circular duplex DNA's. Covalent binding of both platinum complexes to the closed circular DNA alters the degree of supercoiling, presumably by disrupting and unwinding the double helix. Electron micrographs show the platinated DNA's to be shortened by up to 50 percent of their original length. At similar ratios of bound platinum per nucleotide, the electrophoretic mobilities of the DNA's in gels containing the dye ethidium bromide are the same for both isomers. The only detectable difference in the binding of the two platinum isomers is an increase in the electrophoretic mobility in nondye gels of closed circular DNA having small amounts of boundcis-DDP that is not apparent for thetranscomplex.
High Potassium Conductance in Astrocyte Endfeet
Authors: Newman Eric A.
Published: October 2006

The distribution of potassium conductance over the surface of freshly dissociated salamander astrocytes was determined by monitoring cell depolarizations evoked by focal increases in the extracellular potassium concentration. The specific potassium conductance of the endfoot processes of these cells was approximately tenfold higher than the conductance of other cell regions. This dramatically nonuniform conductance distribution may play an important role in the regulation of extracellular potassium levels by glia in the brain.
A Protein Induced During Nerve Growth (GAP-43) is a Major Component of Growth-Cone Membranes
Authors: Skene J. H. Pate , Jacobson Richard D. , Snipes G. Jackson , McGuire C. Brian , Norden Jeanette J. , Freeman John A.
Published: October 2006

Growth cones are specialized structures that form the distal tips of growing axons. During both normal development of the nervous system and regeneration of injured nerves, growth cones are essential for elongation and guidance of growing axons. Developmental and regenerative axon growth is frequently accompanied by elevated synthesis of a protein designated GAP-43. GAP-43 has now been found to be a major component of growth-cone membranes in developing rat brains. Relative to total protein, GAP-43 is approximately 12 times as abundant in growth-cone membranes as in synaptic membranes from adult brains. Immunohistochemical localization of GAP-43 in frozen sections of developing brain indicates that the protein is specifically associated with neuropil areas containing growth cones and immature synaptic terminals. The results support the proposal that GAP-43 plays a role in axon growth.
The Neurobiology of Learning and Memory
Authors: Thompson Richard F.
Published: October 2006

Study of the neurobiology of learning and memory is in a most exciting phase. Behavioral studies in animals are characterizing the categories and properties of learning and memory; essential memory trace circuits in the brain are being defined and localized in mammalian models; work on human memory and the brain is identifying neuronal systems involved in memory; the neuronal, neurochemical, molecular, and biophysical substrates of memory are beginning to be understood in both invertebrate and vertebrate systems; and theoretical and mathematical analysis of basic associative learning and of neuronal networks is proceeding apace. Likely applications of this new understanding of the neural bases of learning and memory range from education to the treatment of learning disabilities to the design of new artificial intelligence systems.
Aging and Health: Effects of the Sense of Control
Authors: Rodin Judith
Published: October 2006

The relation between health and a sense of control may grow stronger in old age. This could occur through three types of processes: experiences particularly relevant to control may increase markedly in old age; the association between control and some aspect of health may be altered by age; and age may influence the association between control and health-related behaviors or the seeking of medical care. Studies show that there are detrimental effects on the health of older people when their control of their activities is restricted; in contrast, interventions that enhance options for control by nursing home patients promote health. With increasing age, however, variability in preferred amounts of control also increases, and sometimes greater control over activities, circumstances, or health has negative consequences including stress, worry, and self-blame. Mechanisms mediating the control-health relation include feelings of stress, symptom labeling, changes in the neuroendocrine and immune systems, and behavior relevant to health maintenance.
Control of Cachectin (Tumor Necrosis Factor) Synthesis: Mechanisms of Endotoxin Resistance
Authors: Beutler Bruce , Krochin Nadia , Milsark Ian W. , Luedke Christina , Cerami Anthony
Published: October 2006

Cachectin (tumor necrosis factor) is a macrophage hormone strongly implicated in the pathogenesis of endotoxin-induced shock. The availability of a DNA probe complementary to the cachectin messenger RNA (mRNA), as well as a specific antibody capable of recognizing the cachectin gene product, has made it possible to analyze the regulation of cachectin gene expression under a variety of conditions. Thioglycollate-elicited peritoneal macrophages obtained from mice contain a pool of cachectin mRNA that is not expressed as protein. When the cells are stimulated with endotoxin, a large quantity of additional cachectin mRNA is produced, and immunoreactive cachectin is secreted. Macrophages from mice of the C3H/HeJ strain do not produce cachectin in response to endotoxin. A dual defect appears to prevent cachectin expression. First, a diminished quantity of cachectin mRNA is expressed in response to low concentrations of endotoxin. Second, a post-transcriptional defect prevents the production of cachectin protein. Macrophages from endotoxin-sensitive mice do not produce cachectin if they are first treated with dexamethasone, apparently for similar reasons. These findings give new insight into the nature of the C3H/HeJ mutation and suggest an important mechanism by which glucocorticoids may act to suppress inflammation.
Calcium Rises Abruptly and Briefly Throughout the Cell at the Onset of Anaphase
Authors: Poenie Martin , Alderton Janet , Steinhardt Richard , Tsien Roger
Published: October 2006

Continuous measurement and imaging of the intracellular free calcium ion concentration ([Ca
2+
]
i
) of mitotic and interphase PtK
1
cells was accomplished with the new fluorescent Ca
2+
indicator fura-2. No statistically significant difference between basal [Ca
2+
]
i
of interphase and mitotic cells was detected. However, mitotic cells showed a rapid elevation of [Ca
2+
]
i
from basal levels of 130 n
M
to 500 to 800 n
M
at the metaphase-anaphase transition. The [Ca
2+
]
i
transient was brief, lasting approximately 20 seconds and the elevated [Ca
2+
]
i
appeared uniformly distributed over the entire spindle and central region of the cell. The close temporal association of the [Ca
2+
]
i
transient with the onset of anaphase suggests that calcium may have a signaling role in this event.
Cadmium: In Vivo Measurement in Smokers and Nonsmokers
Authors: Ellis Kenneth J. , Vartsky David , Zanzi Italo , Cohn Stanton H. , Yasumura Seiichi
Published: October 2006

Absolute amounts of cadmium (in milligrams) in the left kidney and concentrations of cadmium (micrograms per gram) in the liver were measured in vivo in 20 healthy adult male volunteers. Organ cadmium levels of smokers were significantly elevated above those of nonsmokers. No relationship was evident between body stores of cadmium (liver and kidney) and cadmium or β
2
-microglobulin in urine or blood. The average total body burden of cadmium in man at age 50 is estimated to be 19.3 milligrams for nonsmokers and 35.5 milligrams for smokers (38.7 pack-year smoking history). Biological half-time for the whole body was, on average, 15.7 years (10- to 33-year range). Dietary absorption was 2.7 micrograms per day. Cigarette smoking resulted in the absorption of 1.9 micrograms per pack.
The Brain Nucleus Locus Coeruleus: Restricted Afferent Control of a Broad Efferent Network
Authors: Aston-Jones Gary , Ennis Matthew , Pieribone Vincent A. , Nickell W. Thompson , Shipley Michael T.
Published: October 2006

Dense, focal injections of wheat germ agglutinin conjugated-horseradish peroxidase in the locus coeruleus of rats labeled afferent neurons in unexpectedly few brain regions. Major inputs emanate from only two nuclei—the paragigantocellularis and the prepositus hypoglossi, both in the rostral medulla. The dorsal cap of the paraventricular hypothalamic nucleus and the spinal intermediate gray are possible minor afferents to locus coeruleus. Other areas reported to project to locus coeruleus (for example, amygdala, nucleus tractus solitarius, and spinal dorsal horn) did not exhibit consistent retrograde labeling. Anterograde tracing and electrophysiologic experiments confirmed the absence of input to locus coeruleus from these areas, which instead terminate in targets adjacent to locus coeruleus. These findings redefine the anatomic organization of the locus coeruleus, and have implications for hypotheses concerning the functions of this noradrenergic brain nucleus.
Delayed Transneuronal Death of Substantia Nigra Neurons Prevented by γ-Aminobutyric Acid Agonist
Authors: Saji Makoto , Reis Donald J.
Published: October 2006

In an investigation of the mechanism by which brain lesions result in delayed degeneration of neurons remote from the site of injury, neurons within the caudate nucleus of rats were destroyed by local injection of the excitotoxin ibotenic acid. Treatment resulted in the rapid degeneration of the striatonigral pathway including projections containing the inhibitory neurotransmitter γ-aminobutyric acid (GABA) and delayed transneuronal death of neurons in the substantia nigra pars reticulata. The distribution of nigral cell loss corresponded to the loss of GABAergic terminals. Neuronal death was prevented by long-term intraventricular infusion of the GABA agonist muscimol. Delayed transneuronal degeneration may be produced by neuronal disinhibition consequent to loss of inhibitory inputs. Replacement of inhibitory transmitters by suitable drugs may prevent some forms of delayed neuronal death.
Nerve Growth Factor Treatment After Brain Injury Prevents Neuronal Death
Authors: Kromer Lawrence F.
Published: October 2006

Cholinergic neuronal degeneration after axotomy has been proposed to be due to the loss of a retrogradely transported neurotrophic factor, possibly nerve growth factor (NGF). To test this hypothesis, NGF was continuously infused into the lateral ventricles of adult rats that had received bilateral lesions of all cholinergic axons projecting from the medial septum to the dorsal hippocampus. After 2 weeks of NGF treatment, identification of cholinergic neurons by the presence of the biosynthetic enzyme choline acetyltransferase revealed a dramatic increase (350%) in the survival of the axotomized septal cholinergic neurons. Thus, NGF or an NGF-like molecule can act as a neurotrophic factor for these neurons.
Evaluation of Intrinsic Binding Energy from a Hydrogen Bonding Group in an Enzyme Inhibitor
Authors: Bartlett Paul A. , Marlowe Charles K.
Published: October 2006

This and two accompanying reports describe the intrinsic binding energy derived from a single hydrogen bond between an inhibitor and an enzyme. The results were obtained by comparing matched pairs of inhibitors of the zinc endopeptidase thermolysin that bind to the enzyme in an essentially identical manner but differ in the presence or absence of a specific hydrogen bond. This report describes five phosphorus-containing analogs of the peptides carbobenzoxy-Gly-Leu-X, in which the Gly-Leu peptide linkage is replaced with a phosphonate ester (-PO
2
-
-O-). Values for the inhibition constants of these inhibitors show a direct relation with those of the corresponding phosphonamidate analogs (-PO
2
-
-NH- in place of the Gly-Leu peptide moiety), which have been characterized previously as transition state analogs. However, each phosphonate ester is bound about 840 times more weakly than the analogous phosphonamidate, reflecting the loss of 4.0 ± 0.1 kilocalories per mole in binding energy. From these results and the crystallographic analysis in the next report, it can be inferred that the value of 4.0 kilocalories per mole represents the intrinsic binding energy arising from a highly specific hydrogen binding interaction.
Chemistry of Antibody Binding to a Protein
Authors: Geysen H. Mario , Tainer John A. , Rodda Stuart J. , Mason Tom J. , Alexander Hannah , Getzoff Elizabeth D. , Lerner Richard A.
Published: October 2006

The chemistry of antibody recognition was studied by mapping the antigenicity of the protein myohemerythrin with peptide homologs of the protein sequence. The results suggest that the entire protein surface is antigenic, but the probability of there being antibodies to a given site is influenced by local stereochemistry. Although accessible to an antibody binding domain, the least reactive positions cluster in the most tightly packed and least mobile regions and are closely associated with narrow, concave grooves in the molecular surface containing bound water molecules. The most frequently recognized sites form three-dimensional superassemblies characterized by high local mobility, convex surface shape, and often by negative electrostatic potential.
Electrical Responses of Eggs to Acrosomal Protein Similar to Those Induced by Sperm
Authors: Gould Meredith , Stephano José Luis
Published: October 2006

The earliest known response of eggs to sperm in many species is a change in egg membrane potential. However, for no species is it known what components of the sperm cause the opening of the egg plasma membrane channels. Protein isolated from sperm acrosomal granules of the marine worm
Urechis
caused electrical responses in oocytes with the same form, amplitude, and ion dependence as the fertilization potentials induced by living sperm. Sperm initiated fertilization potentials in oocytes when sperm-oocyte fusion, but not binding, was inhibited by clamping oocyte membrane potentials to positive values. Acrosomal protein also initiated electrical responses in clamped oocytes. These results support the hypothesis that it is the sperm acrosomal protein that opens ion channels in the oocyte membrane.
Abrupt Induction of a Membrane Digestive Enzyme by Its Intraintestinal Substrate
Authors: Reisenauer Ann M. , Gray Gary M.
Published: October 2006

The regulation of amino-oligopeptidase (AOP), an intestinal brush border hydrolase essential for the surface digestion of peptide nutrients, was examined in rats in vivo. Short-term (30-minute) intraintestinal perfusion of a tetrapeptide substrate, Gly-Leu-Gly-Gly, or a synthetic substrate, leucyl-β-naphthylamide, induced a doubling in the incorporation of [
3
H]leucine into the AOP in association with intracellular membranes. The subsequent conversion of AOP from nascent to mature enzyme and its membrane-associated transport to the brush border occurred at normal rates.
Sequence and Structure of a Human Glucose Transporter
Authors: Mueckler Mike , Caruso Carla , Baldwin Stephen A. , Panico Maria , Blench Ian , Morris Howard R. , Allard W. Jeffrey , Lienhard Gustav E. , Lodish Harvey F.
Published: October 2006

The amino acid sequence of the glucose transport protein from human HepG2 hepatoma cells was deduced from analysis of a complementary DNA clone. Structural analysis of the purified human erythrocyte glucose transporter by fast atom bombardment mapping and gas phase Edman degradation confirmed the identity of the clone and demonstrated that the HepG2 and erythrocyte transporters are highly homologous and may be identical. The protein lacks a cleavable amino-terminal signal sequence. Analysis of the primary structure suggests the presence of 12 membrane-spanning domains. Several of these may form amphipathic α helices and contain abundant hydroxyl and amide side chains that could participate in glucose binding or line a transmembrane pore through which the sugar moves. The amino terminus, carboxyl terminus, and a highly hydrophilic domain in the center of the protein are all predicted to lie on the cytoplasmic face. Messenger RNA species homologous to HepG2 glucose transporter messenger RNA were detected in K562 leukemic cells, HT29 colon adenocarcinoma cells, and human kidney tissue.
Stimulation of Bone Resorption in Vitro by Synthetic Transforming Growth Factor-Alpha
Authors: Ibbotson K. J. , Twardzik D. R. , D'Souza S. M. , Hargreaves W. R. , Todaro G. J. , Mundy G. R.
Published: October 2006

Experiments were conducted to test the hypothesis that tumor-derived transforming growth factor-alpha (TGF-α) is responsible for the increased bone resorption and hypercalcemia seen in some malignant diseases. Homogeneous synthetic TGF-α prepared by the solid-phase synthesis method stimulated bone resorption directly in vitro in a concentration-dependent manner. Incubation times of 72 hours or more were required to stimulate resorption, which is similar to the time course of bone resorption by epidermal growth factor.
Calcium Dependence of Toxic Cell Death: A Final Common Pathway
Authors: Schanne Francis A. X. , Kane Agnes B. , Young Ellora E. , Farber John L.
Published: October 2006

Primary cultures of adult rat hepatocytes were treated in the presence or absence of extracellular calcium with ten different membrane-active toxins. In all cases more than half the cells were killed in 1 to 6 hours in the presence but not in the absence of extracellular calcium. An effect of calcium on the primary mechanism of membrane injury by any of the agents cannot be implicated. Viability, as determined by trypan blue exclusion correlated well with other indices of viability such as plating efficiency and the hydrolysis of fluorescein diacetate. It is concluded that the cells are killed by processes that involve at least two steps. In each type of injury, disruption of the integrity of the plasma membrane by widely differing mechanisms is followed by a common functional consequence involving extracellular calcium, and most likely representing an influx of calcium across the damaged plasma membrane and down a steep concentration gradient. This later step represents, or at least initiates, a final common pathway for the toxic death of these cells.
Partial Primary Structure of the Alpha and Beta Chains of Human Tumor T-Cell Receptors
Authors: Jones Nancy , Leiden Jeffrey , Dialynas Deno , Fraser John , Clabby Martha , Kishimoto Takashi , Strominger Jack L. , Andrews Dana , Lane William , Woody James
Published: October 2006

The T-cell receptor for antigen (Ti) was purified from the human tumor cell line HPB-ALL. Amino-terminal sequence analysis of an acid-cleaved peptide of the Tiα chain showed that it is highly homologous to a putative murine α chain recently described. Amino-terminal sequence analysis of the Tiβ chain revealed that it shares 50 percent homology with the Tiβ chain amino acid sequences from two other human T-cell tumors. Nucleotide sequence analysis of a complementary DNA clone encoding the Tiβ chain from the HPB-MLT cell line showed that this chain represents a second human constant region gene segment and suggested that it arises from direct joining of the variable and joining gene segments without any intervening D region sequences.
Interleukin-1 Stimulation of Astroglial Proliferation After Brain Injury
Authors: Giulian Dana , Lachman Lawrence B.
Published: October 2006

The interleukins, which have a regulatory role in immune function, may also mediate inflammation associated with injury to the brain. In experiments to determine the effect of these peptide hormones on glial cell proliferation in culture, interleukin-1 was a potent mitogen for astroglia but had no effect on oligodendroglia. Interleukin-2 did not alter the growth of either type of glial cell. Activity similar to that of interleukin-1 was detected in brains of adult rats 10 days after the brains had been injured. These findings suggest that interleukin-1, released by inflammatory cells, may promote the formation of scars by astroglia in the damaged mammalian brain.
Locus of the α-Chain of the T-Cell Receptor Is Split by Chromosome Translocation in T-Cell Leukemias
Authors: Erikson Jan , Williams Dorothy L. , Finan Janet , Nowell Peter C. , Croce Carlo M.
Published: October 2006

Mouse lymphoma cells were hybridized with two human acute T-cell leukemias with a t(11;14) (p13;q11) translocation and the segregated hybrids were examined for the presence of the DNA segments coding for the constant (C) and the variable (V) regions of the α chain (C
α
and V
α
) of the T-cell receptor. The C
α
segment was translocated to the involved chromosome 11 (11p
+
) while the V
α
segment remained on the involved chromosome 14 (14q
-
). The data indicate that the locus for the α chain of the T-cell receptor is split by the chromosomal breakpoint between the V
α
and the C
α
gene segments, and that the V
α
segments are proximal to the C
α
segment within chromosome band 14q11.2.
Receptor-Mediated Transport of Insulin Across Endothelial Cells
Authors: King George L. , Johnson Sandra M.
Published: October 2006

Hormones such as insulin are transported from the interior to the exterior of blood vessels. Whether endothelial cells, which line the inner walls of blood vessels have a role in this transport of hormones is not clear, but it is known that endothelial cells can internalize and release insulin rapidly with little degradation. The transport of iodine-125-labeled insulin was measured directly through the use of dual chambers separated by a horizontal monolayer of cultured bovine aortic endothelial cells. In this setting, endothelial cells took up and released the labeled insulin, thereby transporting it across the cells. The transport of insulin across the endothelial cells was temperature sensitive and was inhibited by unlabeled insulin and by antibody to insulin receptor in proportion to the ability of these substances to inhibit insulin binding to its receptor. More than 80 percent of the transported insulin was intact. These data suggest that insulin is rapidly transported across endothelial cells by a receptor-mediated process.
Function and Autoregulation of Yeast Copperthionein
Authors: Hamer Dean H. , Thiele Dennis J. , Lemontt Jeffrey E.
Published: October 2006

The
CUP1
gene of yeast encodes a small, metallothionein-like protein that binds to and is inducible by copper. A gene replacement experiment shows that this protein protects cells against copper poisoning but is dispensable for normal cellular growth and development throughout the yeast life cycle. The transcription of
CUP1
is negatively autoregulated. This feedback mechanism, which is mediated through upstream control sequences, may play an important role in heavy metal homeostasis.
Immunocytochemical Detection of Acetylcholine in the Rat Central Nervous System
Authors: Geffard M. , McRae-Degueurce A. , Souan Marie Laure
Published: October 2006

A specific antibody to acetylcholine was raised and used as a marker for cholinergic neurons in the rat central nervous system. The acetylcholine conjugate was obtained by a two-step immunogen synthesis procedure. An enzyme-linked immunosorbent assay was used to test the specificity and affinity of the antibody in vitro; the results indicated high affinity. A chemical perfusion mixture of allyl alcohol and glutaraldehyde was used to fix the acetylcholine in the nervous tissue. Peroxidase-antiperoxidase immunocytochemistry showed many acetylcholine-immunoreactive cells and fibers in sections from the medial septum region.
Diazepam-Binding Inhibitor: A Neuropeptide Located in Selected Neuronal Populations of Rat Brain
Authors: Alho H. , Costa E. , Ferrero P. , Fujimoto M. , Cosenza-Murphy D. , Guidotti A.
Published: October 2006

An endogenous polypeptide of rat brain has been identified that is capable of displacing 1,4-benzodiazepines and the esters of the 3-carboxylic acid derivatives of β-carbolines from their specific synaptic binding sites. This polypeptide was termed diazepam-binding inhibitor (DBI). Previous studies have shown that DBI injected intraventricularly in rodents elicits "proconflict" responses and antagonizes the "anticonflict" action of benzodiazepines. An antiserum to this peptide, directed toward an immunodeterminant near its amino terminus, makes it possible to detect, measure, and study the neuronal location of this peptide in rat brain. In the rat cerebral cortex, DBI immunoreactivity is located in neurons that are not GABAergic (GABA, γ-aminobutyric acid); in the cerebellum and hippocampus, however, it might be present also in GABAergic neurons.
Immunoprecipitation of Insulin Receptors from Cultured Human Lymphocytes (IM-9 Cells) by Antibodies to pp60
src
Authors: Perrotti Nicola , Taylor Simeon I. , Richert Nancy D. , Rapp Ulf R. , Pastan Ira H. , Roth Jesse
Published: October 2006

The family of tyrosine-specific protein kinases includes proteins encoded by retroviral oncogenes as well as receptors for insulin and several growth factors. Antibodies to pp60
src
, the protein encoded by the
src
oncogene of Rous sarcoma virus (RSV), can specifically immunoprecipitate affinity-labeled insulin receptors from cultured human lymphocytes (IM-9 cells). This precipitation is specifically inhibited by the
src
gene product purified from RSV-transformed rat cells. These observations provide evidence that there is structural homology between the insulin receptors and pp60
src
.
Chromosomal Locations of the Murine T-Cell Receptor Alpha-Chain Gene and the T-Cell Gamma Gene
Authors: Kranz David M. , Saito Haruo , Disteche Christine M. , Swisshelm Karen , Pravtcheva Dimitrina , Ruddle Frank H. , Eisen Herman N. , Tonegawa Susumu
Published: October 2006

Two independent methods were used to identify the mouse chromosomes on which are located two families of immunoglobulin (Ig)-like genes that are rearranged and expressed in T lymphocytes. The genes coding for the α subunit of T-cell receptors are on chromosome 14 and the gamma genes, whose function is yet to be determined, are on chromosome 13. Since genes for the T-cell receptor β chain were previously shown to be on mouse chromosome 6, all three of the Ig-like multigene families expressed and rearranged in T cells are located on different chromosomes, just as are the B-cell multigene families for the Ig heavy chain, and the Ig kappa and lambda light chains. The findings do not support earlier contentions that genes for T-cell receptors are linked to the Ig heavy chain locus (mouse chromosome 12) or to the major histocompatibility complex (mouse chromosome 17).
Human GM-CSF: Molecular Cloning of the Complementary DNA and Purification of the Natural and Recombinant Proteins
Authors: Wong Gordon G. , Witek JoAnn S. , Temple Patricia A. , Wilkens Kathleen M. , Leary Anne C. , Luxenberg Deborah P. , Jones Simon S. , Brown Eugene L. , Kay Robert M. , Orr Elizabeth C. , Shoemaker Charles , Golde David W. , Kaufman Randal J. , Hewick Rodney M. , Wang, Elizabeth A. , Clark, Steven C.
Published: October 2006

Clones of complementary DNA encoding the human lymphokine known as granulocyte-macrophage colony-stimulating factor (GM-CSF) were isolated by means of a mammalian cell (monkey COS cell) expression screening system. One of these clones was used to produce recombinant GM-CSF in mammalian cells. The recombinant hematopoietin was similar to the natural product that was purified to apparent homogeneity from medium conditioned by a human T-cell line. The human T-cell GM-CSF was found to be 60 percent homologous with the GM-CSF recently cloned from murine lung messenger RNA.
Localization of the Gene Encoding the Human Interleukin-2 Receptor on Chromosome 10
Authors: Leonard Warren J. , Donlon Tim A. , Lebo Roger V. , Greene Warner C.
Published: October 2006

The human interleukin-2 receptor is an inducible growth factor receptor present on the surface of activated T lymphocytes. The receptor is required for a normal T-cell immune response. High-resolution fluorescence-activated chromosome sorting and DNA spot-blot analysis with complementary DNA's for the interleukin-2 receptor indicated that the receptor gene was located on chromosome 9, 10, 11, or 12. In situ hybridization studies showed that the interleukin-2 receptor gene is on the short arm of chromosome 10, p14 → 15.
Tyrosine Hydroxylase Immunoreactivity in Familial Dysautonomia
Authors: Pearson John , Brandeis Leslie , Goldstein Menek
Published: October 2006

Tyrosine hydroxylase antigen was localized immunohistochemically in sympathetic neurons from human autopsy tissue. The reaction persists in paraffin-embedded tissue, and the method is applicable to archival specimens. Increased amounts in this antigen per cell may partially compensate for decreased numbers of sympathetic neurons in familial dysautonomia.
Effect of β-Endorphin on Calcium Uptake in the Brain
Authors: Guerrero-Munoz Federico , Guerrero Marie de Lourdes , Way E. Leong , Li Choh Hao
Published: October 2006

The uptake of
45
Ca
2+
by nerve-ending fractions from brains of mice was inhibited in vitro by 10
-9
M
concentrations of β-endorphin and in mice injected intraventricularly with 7 picomoles of β-endorphin. That the effect was a specific opiate agonist response of β-endorphin was demonstrated by use of the opiate antagonist, naloxone, which reversed the action. A role for β-endorphin in the regulation of calcium flux and neurotransmitter release should be considered.
Industrial Support of University Research in Biotechnology
Authors: Blumenthal David , Gluck Michael , Louis Karen Seashore , Wise David
Published: October 2006

A 1984 study of biotechnology companies reveals that nearly one-half of all such firms fund research in universities. Industry may support as much as one-quarter of all biotechnology research in institutions of higher education. These investments seem to be yielding substantial benefits to involved firms. Per dollar invested, university research is generating more patent applications than is other company research. Research relationships do pose some risks to traditional university values such as openness of communication among scholars. These risks may be greater in relationships involving small firms. The data also reveal that government is now, and seems likely to remain, the principal source of support for university research in biotechnology.
Dynamics of Lymphocyte-Endothelial Interactions in Vivo
Authors: Bjerknes Matthew , Cheng Hazel , Ottaway Clifford A.
Published: October 2006

The dynamics of the attachment of lymphocytes to the endothelium of high endothelial venules in murine Peyer's patches were studied in vivo. Lymphocytes adhered readily to the endothelium lining these vessels, but most of the adhering cells detached within a few seconds. Many lymphocytes, however, experienced multiple collisions with the high endothelial venules, and this substantially increased the efficiency of lymphocyte collection by these vessels.
The Intervening Sequence RNA of
Tetrahymena
Is an Enzyme
Authors: Zaug Arthur J. , Cech Thomas R.
Published: October 2006

A shortened form of the self-splicing ribosomal RNA (rRNA) intervening sequence of
Tetrahymena thermophila
acts as an enzyme in vitro. The enzyme catalyzes the cleavage and rejoining of oligonucleotide substrates in a sequence-dependent manner with
K
m
= 42 μ
M
and
k
cat
= 2 min-1. The reaction mechanism resembles that of rRNA precursor self-splicing. With pentacytidylic acid as the substrate, successive cleavage and rejoining reactions lead to the synthesis of polycytidylic acid. Thus, the RNA molecule can act as an RNA polymerase, differing from the protein enzyme in that it uses an internal rather than an external template. At
p
H 9, the same RNA enzyme has activity as a sequence-specific ribonuclease.
Expression of an Epidermal Antigen Used to Study Tissue Induction in the Early
Xenopus laevis
Embryo
Authors: Akers Rebecca M. , Phillips Carey R. , Wessells Norman K.
Published: October 2006

A monoclonal antibody (Epi 1) has been produced that recognizes an antigen expressed in epidermal cells of
Xenopus laevis
embryos. The Epi 1 antigen appears in embryonic epidermis at the end of gastrulation and is not expressed in nonepidermal structures derived from ectoderm (for example, neural tube or cement gland). The capacity to express the Epi 1 antigen is restricted to cells of the animal hemisphere prior to the midblastula stage of development (stage 8), and tissue interactions during gastrulation inhibit the expression of the Epi 1 antigen in neural ectoderm. This epidermal antigen will be a valuable marker for studies of ectodermal commitment.
L-Isoleucine and L-Leucine: Tumor Promoters of Bladder Cancer in Rats
Authors: Nishio Yasunori , Kakizoe Tadao , Ohtani Mikinobu , Sato Shigeaki , Sugimura Takashi , Fukushima Shoji
Published: October 2006

A 4-week assay for screening tumor promoters of bladder cancer has been developed in which increased agglutinability of isolated rat bladder cells with concanavalin A is used as an indicator. On the basis of this assay system, L-isoleucine and L-leucine were suspected of being possible tumor promoters. Results of 40- to 60-week carcinogenesis experiments in which
N
-butyl-
N
-(4- hydroxybutyl)nitrosamine was used as an initiator demonstrate that L-isoleucine and L-leucine promote bladder cancer in rats. This finding may be relevant to the high incidence of human bladder cancer in Western countries, where the diet is rich in protein.
Symmetry in Running
Authors: Raibert Marc H.
Published: October 2006

Symmetry plays a key role in simplifying the control of legged robots and in giving them the ability to run and balance. The symmetries studied describe motion of the body and legs in terms of even and odd functions of time. A legged system running with these symmetries travels with a fixed forward speed and a stable upright posture. The symmetries used for controlling legged robots may help in elucidating the legged behavior of animals. Measurements of running in the cat and human show that the feet and body sometimes move as predicted by the even and odd symmetry functions.
Concurrent Overproduction of Synapses in Diverse Regions of the Primate Cerebral Cortex
Authors: Rakic Pasko , Bourgeois Jean-Pierre , Eckenhoff Maryellen F. , Zecevic Nada , Goldman-Rakic Patricia S.
Published: October 2006

Synapses develop concurrently and at identical rates in different layers of the visual, somatosensory, motor, and prefrontal areas of the primate cerebral cortex. This isochronic course of synaptogenesis in anatomically and functionally diverse regions indicates that the entire cerebral cortex develops as a whole and that the establishment of cell-to-cell communication in this structure may be orchestrated by a single genetic or humoral signal. This is in contrast to the traditional view of hierarchical development of the cortical regions and provides new insight into the maturation of cortical functions.
Suprachiasmatic Nucleus Vasopressin Messenger RNA: Circadian Variation in Normal and Brattleboro Rats
Authors: Uhl George R. , Reppert Steven M.
Published: October 2006

In situ hybridization of an oligonucleotide probe complementary to vasopressin messenger RNA (mRNA) in sections from normal or Brattleboro rat hypothalami revealed hybridization densities in each of three vasopressin-rich nuclei: the supraoptic, paraventricular, and suprachiasmatic. When entrained to a daily light-dark cycle, each rat strain displayed diurnal variation in hybridizable mRNA in the suprachiasmatic, but not in the supraoptic or paraventricular nuclei. The higher values for suprachiasmatic mRNA in the morning correlate well with previously elucidated morning increases in vasopressin immunoreactivity in the cerebrospinal fluid. These results (i) support the utility of in situ hybridization techniques for elucidating physiological influences on regional peptidergic function, (ii) are consistent with a prominent role for vasopressinergic suprachiasmatic neurons in generating the cerebrospinal fluid vasopressin rhythm, and (iii) suggest that regulation of this mRNA rhythm is not dependent on release of intact peptide.
Androgens Regulate the Dendritic Length of Mammalian Motoneurons in Adulthood
Authors: Kurz Elizabeth M. , Sengelaub Dale R. , Arnold Arthur P.
Published: October 2006

Sex steroid hormones have been thought to alter behaviors in adulthood by changing the activity of neural circuits rather than by inducing major structural changes in these pathways. In a group of androgen-sensitive motoneurons that mediate male copulatory functions, decreases in androgen levels after castration of adult rats produced dramatic structural changes, decreasing both the dendritic length and soma size of these motoneurons. These changes were reversed by androgen replacement. These results imply a surprising degree of synaptic plasticity in adult motoneurons and suggest that normal changes in androgen levels in adulthood are associated with significant alterations in the structure and function of these neurons.
Targeted Modulation of Acute Inflammation
Authors: Ranney David F.
Published: October 2006

Localized inflammation of the lungs was induced with the neutrophil chemoattractant,
N
-formylmethionylleucylphenylalanine (FMLP) in combination with magnetically responsive albumin microspheres, a drug carrier that provides efficient, extremely rapid localization in tissue. Intravenous targeting to rat lungs was accomplished by means of an external thoracic magnet. This caused progressive local accumulation of neutrophils, extravascular cell migration, and acute tissue injury. Microscopic findings favored chemotaxis as the principal mechanism of cell accumulation. This system provides a new experimental model for acute alveolar damage, a rapid in vivo assay for drugs that modulate neutrophil chemotaxis, and a new therapeutic approach to focusing inflammation in patients with chemotactic defects.
Evoked Mechanical Responses of Isolated Cochlear Outer Hair Cells
Authors: Brownell William E. , Bader Charles R. , Bertrand Daniel , de Ribaupierre Yves
Published: October 2006

Intracellular current administration evokes rapid, graded, and bidirectional mechanical responses of isolated outer hair cells from the mammalian inner ear. The cells become shorter in response to depolarizing and longer in response to hyperpolarizing currents in the synaptic end of the cell. The cells respond with either an increase or decrease in length to transcellular alternating current stimulation. The direction of the movement with transcellular stimuli appears to be frequency dependent. Iontophoretic application of acetylcholine to the synaptic end of the cell decreases its length. The microarchitecture of the organ of Corti permits length changes of outer hair cells in a manner that could significantly influence the mechanics of the cochlear partition and thereby contribute to the exquisite sensitivity of mammalian hearing.
Flurbiprofen: A Potent Inhibitor of Alveolar Bone Resorption in Beagles
Authors: Williams R. C. , Jeffcoat M. K. , Kaplan M. L. , Goldhaber P. , Johnson H. G. , Wechter W. J.
Published: October 2006

The nonsteroidal anti-inflammatory drug, flurbiprofen, a potent cyclooxygenase inhibitor, significantly decreases the resorption of alveolar bone in naturally occurring chronic destructive periodontal disease in beagles. This observation indicates that arachidonic acid metabolites are important in the alveolar bone loss of periodontitis and suggests a use for flurbiprofen in the management of bone resorption disease.
The Goldfish as a Retinex Animal
Authors: Ingle David J.
Published: October 2006

In an experiment designed to test color constancy in a situation comparable to that used in E. H. Land's experiments with human observers, goldfish were trained to approach a particular color within a richly colored but variable "Mondrian" background. They retained the ability to identify colors accurately even when the spectral composition of the illuminant was radically altered in generalization tests. Since the behavior of fish resembles that of human beings in these tests, Land's retinex theory seems to apply to a relatively primitive vertebrate as well as to humans.
Two Gustatory Systems: Facial and Vagal Gustatory Nuclei Have Different Brainstem Connections
Authors: Finger Thomas E. , Morita Yasuhiro
Published: October 2006

The gustatory sense in catfish consists of two dissociable components, a facial nerve system used for food selection and a vagal nerve system involved in swallowing. Neural tracing experiments demonstrate that the primary sensory nucleus for the facial gustatory system is connected to the reticular formation and trigeminal nuclei. In contrast, the primary sensory nucleus for the vagal gustatory system is connected to the motoneurons that mediate swallowing. These results provide anatomical evidence for parallel gustatory systems within the vertebrate central nervous system.
Crystallographic Structure of the Octameric Histone Core of the Nucleosome at a Resolution of 3.3 Å
Authors: Burlingame Rufus W. , Love Warner E. , Wang Bi-Chen , Hamlin Ron , Xuong Nguyen-Huu , Moudrianakis Evangelos N.
Published: October 2006

The structure of the (H2A-H2B-H3-H4)
2
histone octamer has been determined by means of x-ray crystallographic techniques at a resolution of 3.3 angstroms. The octamer is a prolate ellipsoid 110 angstroms long and 65 to 70 angstroms in diameter, and its general shape is that of a rugby ball. The size and shape are radically different from those determined in earlier studies. The most striking feature of the histone octamer is its tripartite organization, that is, a central (H3-H4)
2
tetramer flanked by two H2A-H2B dimers. The DNA helix, placed around the octamer in a path suggested by the features on the surface of the protein, appears like a spring holding the H2A-H2B dimers at either end of the (H3-H4)
2
tetramer.
Knowledge Without Awareness: An Autonomic Index of Facial Recognition by Prosopagnosics
Authors: Tranel Daniel , Damasio Antonio R.
Published: October 2006

Prosopagnosia, the inability to recognize visually the faces of familiar persons who continue to be normally recognized through other sensory channels, is caused by bilateral cerebral lesions involving the visual system. Two patients with prosopagnosia generated frequent and large electrodermal skin conductance responses to faces of persons they had previously known but were now unable to recognize. They did not generate such responses to unfamiliar faces. The results suggest that an early step of the physiological process of recognition is still taking place in these patients, without their awareness but with an autonomic index.
Steroid-Dependent Survival of Identifiable Neurons in Cultured Ganglia of the Moth
Manduca sexta
Authors: Bennett Kelly L. , Truman James W.
Published: October 2006

Adult emergence at the end of metamorphosis in the moth
Manduca sexta
is followed by the death of abdominal interneurons and motoneurons. Abdominal ganglia removed from insects before this period of naturally occurring cell death and maintained in vitro showed neuronal death confined to the same cells that normally die in vivo. Addition of physiological levels of the steroid 20-hydroxyecdysone to the culture system prevented the selective death of these motoneurons.
Ribonuclease P Catalysis Differs from Ribosomal RNA Self-Splicing
Authors: Marsh Terry L. , Pace Norman R.
Published: October 2006

Two RNA-catalyzed reactions have been described, the
Tetrahymena
self-splicing ribosomal RNA and ribonuclease P. The
Tetrahymena
self-splicing reaction proceeds through a transesterification cascade that is dependent upon nucleophilic attacks by ribose 3′-OH groups. Periodate oxidation of the catalytic (or substrate) RNA, which destroys the nucleophilicity of RNA 3′ termini, did not inhibit ribonuclease P activity. Thus, catalysis by ribonuclease P differs from the self-splicing reaction.
Hallucinogenic Amphetamine Selectively Destroys Brain Serotonin Nerve Terminals
Authors: Ricaurte G. , Bryan G. , Strauss L. , Seiden L. , Schuster C.
Published: October 2006

(±)-3,4-Methylenedioxyamphetamine (MDA), an amphetamine analog with hallucinogenic activity, produced selective long-lasting reductions in the level of serotonin, the number of serotonin uptake sites, and the concentration of 5-hydroxyindoleacetic acid in rat brain. Morphological studies suggested that these neurochemical deficits were due to serotonin nerve terminal degeneration. These results show that MDA has toxic activity for serotonin neurons in rats and raise the question of whether exposure to MDA and related hallucinogenic amphetamines can produce serotonin neurotoxicity in the human brain.
Conjugal Transfer of the Gonococcal Penicillinase Plasmid
Authors: Eisenstein B. I. , Sox T. , Biswas G. , Blackman E. , Sparling P. F.
Published: October 2006

Certain gonococci, which heretofore have lacked a conjugal mating system, can sexually transfer a small plasmid (4.5 × 10
6
daltons) which carries the gene for β-lactamase production. Frequencies of conjugal transfer were similar into diverse recipients (other gonococci,
Neisseria flava
, and
Escherichia coli
), which suggests that gonococci may transfer the plasmid promiscuously in nature.