bluuebunny/crossref_metadata_2025 huggingface dataset:
Promoting Functional Plasticity in the Damaged Nervous System
Authors: Freed William J. , de Medinaceli Luis , Wyatt Richard Jed
Published: October 2006

Damage to the central and peripheral nervous system often produces lasting functional deficits. A major focus of neuroscience research has been to enhance functional restitution of the damaged nervous system and thereby produce recovery of behavioral or physiological processes. Promising procedures include surgical, physical, and chemical manipulations to reduce scar formation and minimize the disruption of support elements, administration of growth-stimulating substances, tissue grafts to bridge gaps in fiber pathways, and embryonic brain tissue grafts to provide new cells with the potential to generate fiber systems. Two elements are required for functional nervous system repair: (i) neurons with the capacity to extend processes must be present, and (ii) the regenerating neurites must find a continuous, unbroken pathway to appropriate targets through a supportive milieu.
Blood-Brain Barrier: Endogenous Modulation by Adrenal-Cortical Function
Authors: Long Joseph B. , Holaday John W.
Published: October 2006

The blood-brain barrier restricts the passage of molecules from the blood to the brain. The permeability of the barrier to iodine-125-labeled bovine serum albumin was examined in rats that had undergone adrenalectomy, adrenal demedullation, and corticosterone replacement. Adrenalectomy, but not adrenal demedullation, increased the permeability of brain tissue to the isotopically labeled macromolecule; corticosterone replacement reversed this effect. These results indicate that the blood-brain barrier may be hormonally regulated; that is, the pituitary-adrenal axis may physiologically modulate the permeability of the brain microvasculature to macromolecules.
Geometrical Differences Among Homologous Neurons in Mammals
Authors: Purves Dale , Lichtman Jeff W.
Published: October 2006

The dendritic arbors of sympathetic neurons in different species of mammals vary systematically: the superior cervical ganglion cells of smaller mammals have fewer and less extensive dendrites than the homologous neurons in larger animals. This difference in dendritic complexity according to body size is reflected in the convergence of ganglionic innervation; the ganglion cells of progressively larger mammals are innervated by progressively more axons. These relations have implications both for the function of homologous neural systems in animals of different sizes and for the regulation of neuronal geometry during development.
Insulin, Glucagon, and Glucose Exhibit Synchronous, Sustained Oscillations in Fasting Monkeys
Authors: Goodner Charles J. , Walike Barbara C. , Koerker Donna J. , Ensinck John W. , Brown Arthur C. , Chideckel Elliott W. , Palmer Jerry , Kalnasy Lynne
Published: October 2006

In overnight fasted rhesus monkeys, synchronous, regular oscillations occurred in the plasma concentrations of glucose, insulin, and glucagon. The oscillations displayed a period averaging 9 minutes. The amplitudes for insulin and glucagon were ten and five times greater than for glucose. Insulin cycled in and glucagon out of phase with glucose. In baboons, oscillations of glucose and insulin were smaller than in rhesus monkeys, while in man, regular oscillations were not observed.
Influence of Cartilage Geometry on the Pressure Distribution in the Human Hip Joint
Authors: Rushfeld Paul D. , Mann Robert W. , Harris William H.
Published: October 2006

To elucidate the role of mechanical factors in the etiology of osteoarthritis, the detailed geometry of the weight-bearing cartilage layer over the human hip socket is compared with the corresponding pressure distribution. The shape of the pressure distribution is strongly correlated with the shape of the cartilage compression distribution.
Periodicity of Deoxyribonuclease I Digestion of Chromatin
Authors: Prunell A. , Kornberg R. D. , Lutter L. , Klug A. , Levitt M. , Crick F. H. C.
Published: October 2006

Two methods have been used to measure the single-strand lengths of the DNA fragments produced by deoxyribonuclease I digestion of chromatin. The average lengths obtained are multiples of about 10.4 bases, significantly different from the value of 10 previously reported. This periodicity in fragment lengths is closely related to the periodicity of the DNA double helix in chromatin, but the two values need not be exactly the same.
Erythrocytes: A New Cell Type for the Evaluation of Insulin Receptor Defects in Diabetic Humans
Authors: Robinson T. J. , Archer J. A. , Gambhir K. K. , Hollis V. W. , Carter L. , Bradley C.
Published: October 2006

Human erythrocytes have specific insulin receptors. When studied in an insulin radioreceptor assay, erythrocytes from adult-onset, nonobese diabetic subjects bound at least 42 percent less insulin than the normal subjects at insulin concentrations from 0.1 to 100 nanograms per milliliter. The diabetic subjects had 190 insulin receptor sites per cell as compared with the 380 insulin receptor sites per cell for the normal subjects. The deficit of insulin binding in the diabetic subject was thus associated with a fewer number of insulin binding sites per cell with little or no change in affinity. The erythrocyte is a readily available cell for the evaluation of cellular insulin receptor activity.
Shifts in Perception of Size After Adaptation to Gratings
Authors: Frome Francine S. , Levinson John Z. , Danielson John T. , Clavadetscher John E.
Published: October 2006

After viewing a suitable grating of vertical stripes for 5 minutes, subjects overestimated the width of a rectangle by 6 percent. The shifts in perception of size occurred whether individual stripes in the grating were narrower than, equal to, or wider than the rectangle. Rectangle width was underestimated only if the grating stripes were extremely wide, with a spatial frequency lower than most of the effective amplitude spectrum of the rectangle. These findings (and complementary ones with horizontal gratings) suggest that the visual system codes size on the basis of spatial frequency components, rather than directly in terms of width.
Rhodopsin Kinase Activity in the Mammalian Pineal Gland and Other Tissues
Authors: Somers Robert L. , Klein David C.
Published: October 2006

Rhodopsin kinase, an enzyme involved in photochemical transduction in the retina, has been found in the mammalian pineal gland in amounts equal to those in the retina; other tissues had 7 percent of this amount, or less. This finding suggests that, in mammals, rhodopsin kinase functions in the pineal gland and other tissues to phosphorylate rhodopsin-like integral membrane receptors and is thereby involved in signal transduction.
Korean Hemorrhagic Fever: Propagation of the Etiologic Agent in a Cell Line of Human Origin
Authors: French George R. , Foulke Richard S. , Brand Orville A. , Eddy Gerald A. , Lee Ho Wang , Lee Pyung Woo
Published: October 2006

The etiologic agent of Korean hemorrhagic fever has been propagated in a human cultured cell line derived from a carcinoma of the lung. The cells, described as type II, alveolar epithelial, support replication of the agent and successive passages. Antigen of the Korean hemorrhagic fever agent is readily detected in infected cells by means of direct or indirect fluorescent antibody techniques. Previous attempts to propagate this agent in vitro had been unsuccessful.
Abnormal Glutamate Metabolism in an Adult-Onset Degenerative Neurological Disorder
Authors: Plaitakis Andreas , Berl Soll , Yahr Melvin D.
Published: October 2006

In patients with recessive, adult-onset olivopontocerebellar degeneration associated with a partial deficiency of glutamate dehydrogenase, the concentration of glutamate in plasma was significantly higher than that in controls. Plasma α-ketoglutarate was significantly lower. Oral administration of monosodium glutamate resulted in excessive accumulation of this amino acid in plasma and lack of increase in the ratio of plasma lactate to pyruvate in the glutamate dehydrogenase-deficient patients. Decreased glutamate catabolism may result in an excess of glutamate in the nervous system and cause neuronal degeneration.
Irreversible Ligands with High Selectivity Toward δ and μ Opiate Receptors
Authors: Rice Kenner C. , Jacobson Arthur E. , Burke Terrence R. , Bajwa Balbir S. , Streaty Richard A. , Klee Werner A.
Published: October 2006

Alkylating agents that display strong selectivity for opiate receptor types δ or μ were prepared by appropriate modification of the structures of the strong analgesics fentanyl, etonitazene, and endoethenotetrahydrooripavine. The availability of these substances should facilitate studies of the structural basis of receptor specificity and of the physiologic roles of these receptors.
The Biochemistry of Memory: A New and Specific Hypothesis
Authors: Lynch Gary , Baudry Michael
Published: October 2006

Recent studies have uncovered a synaptic process with properties required for an intermediate step in memory storage. Calcium rapidly and irreversibly increases the number of receptors for glutamate (a probable neurotransmitter) in forebrain synaptic membranes by activating a proteinase (calpain) that degrades fodrin, a spectrin-like protein. This process provides a means through which physiological activity could produce long-lasting changes in synaptic chemistry and ultrastructure. Since the process is only poorly represented in the brain stem, it is hypothesized to be responsible for those forms of memory localized in the telencephalon.
HEL Cells: A New Human Erythroleukemia Cell Line with Spontaneous and Induced Globin Expression
Authors: Martin Paul , Papayannopoulou Thalia
Published: October 2006

A new human erythroleukemia cell line has been established. This line, designated HEL, is capable of spontaneous and induced globin synthesis, producing mainly Gγ and Aγ chains. Embryonic chains (ε, ζ) and α chains are detectable in very small amounts; β chains are undetectable. This line provides a new model system for studying aspects of erythroid cell differentiation and differential globin gene expression.
A Bean α-Amylase Inhibitor Formulation (Starch Blocker) Is Ineffective in Man
Authors: Carlson Gerald L. , Li B. Ulysses K. , Bass Paul , Olsen Ward A.
Published: October 2006

A commercial α-amylase inhibitor with potent inhibitory activity in vitro was used in a randomized double-blind, cross-over clinical trial in six nonobese, healthy adult males. In these subjects, this inhibitor had no effect on the response of blood glucose, insulin, or breath hydrogen to a standardized starch meal. It is concluded that this formulation has no effect on starch digestion in humans.
Ammonia Intoxication in the Near-Adult Cat as a Result of a Dietary Deficiency of Arginine
Authors: Morris James G. , Rogers Quinton R.
Published: October 2006

Near-adult cats, fasted overnight, and given a single meal of a complete amino acid diet without arginine, developed hyperammonemia and showed clinical symptoms of ammonia toxicity within 2 hours. One cat (2.7 kilograms) died 4.5 hours after ingesting only 8 grams of the diet. Since ornithine also prevented hyperammonemia, it appears that the domestic cat cannot synthesize ornithine.
Expression of Glial Fibrillary Acidic Protein in Immature Oligodendroglia
Authors: Choi Ben H. , Kim Ronald C.
Published: October 2006

In the human fetal spinal cord at 15 to 16 weeks, glial fibrillary acidic protein (GFAP) was demonstrated within the cytoplasm and processes of cells having the cytological, ultrastructural, and immunocytochemical features of oligodendrocytes—including processes that extend into and contribute to the formation of myelin sheaths. By 17 to 18 weeks, however, GFAP immunoreactivity was no longer evident within such cells. Thus GFAP is expressed by myelin-forming oligodendroglia early in their development.
Promoter Sequences of Eukaryotic Protein-Coding Genes
Authors: Corden J. , Wasylyk B. , Buchwalder A. , Sassone-Corsi P. , Kedinger C. , Chambon P.
Published: October 2006

In vitro genetic techniques were used to study the sequence requirements for the initiation of specific transcription. Deletion mutants were constructed around the putative promoter of the adenovirus-2 major late and chicken conalbumin genes. Specific transcription in vitro by RNA polymerase B together with a HeLa cell cytoplasmic extract was used as the test for promoter function. With this approach sequences which are essential for the initiation of specific transcription in vitro, were shown to be located between 12 and 32 base pairs upstream from the 5′ end of these genes.
Memory Performance of Chemical Workers Exposed to Polybrominated Biphenyls
Authors: Brown Gregory G. , Preisman Richard C. , Anderson Marvin D. , Nixon Robert K. , Isbister John L. , Price Harold A.
Published: October 2006

Twenty-five chemical workers who manufactured polybrominated biphenyls (PBB's) were given objective tests of learning and memory. Although this group had high concentrations of PBB's in adipose tissue, mean scores on all memory tests were normal. The PBB concentration was not correlated with memory performance; the most contaminated workers showed no evidence of memory dysfunction.
Glucoreceptors Controlling Feeding and Blood Glucose: Location in the Hindbrain
Authors: Ritter Robert C. , Slusser Peter G. , Stone Steven
Published: October 2006

Microinfusion of 5-thioglucose into either the lateral or fourth cerebral ventricle caused increased feeding and hyperglycemia in rats when the cerebral aqueduct was unobstructed. If the aqueduct was obstructed and 5-thioglucose was infused into the fourth ventricle, increased feeding and hyperglycemia persisted, whereas feeding and hyperglycemia in response to lateral ventricle infusion were abolished. Drinking in response to infusion of angiotensin II into the lateral ventricle was not diminished by aqueduct obstruction. These results indicate that glucoreceptors that mediate feeding and hyperglycemia in response to cerebral glucoprivation are located in the caudal hindbrain and not in the hypothalamus where they have previously been sought.
Pituitary Gastrins Occur in Corticotrophs and Melanotrophs
Authors: Larsson L.-I. , Rehfeld J. F.
Published: October 2006

The gut hormone gastrin was identified in pituitary cells containing adrenocorticotropic hormone and α-melanocyte—stimulating hormone by region-specific immunocytochemistry and radioimmunoassays. Smaller amounts of gastrin were found in nerve fibers of the neural lobe and pituitary stalk. Since adrenocorticotropic hormone—like peptides occur in antropyloric gastrin cells, these data indicate a considerable similarity in peptide composition of pituitary and gastrointestinal endocrine cells and reinforces questions of multiple hormone production.
Yeast Mating Pheromone Activates Mammalian Gonadotrophs: Evolutionary Conservation of a Reproductive Hormone?
Authors: Loumaye Ernest , Thorner Jeremy , Catt Kevin J.
Published: October 2006

α-Factor, a tridecapeptide mating pheromone of yeast (
Saccharomyces cerevisiae
), has extensive sequence homology with the hypothalamic decapeptide gonadotropin-releasing hormone (GnRH). Both synthetic and natural preparations of α-mating factor were found to bind specifically to rat pituitary GnRH receptors and to stimulate the release of luteinizing hormone from cultured gonadotrophs. The ability of the yeast pheromone to reproduce the biological actions of GnRH in the mammalian pituitary gland indicates that the structural and functional properties of GnRH-related peptides may have been highly conserved during evolution.
Virus-Induced Autoimmunity: Monoclonal Antibodies That React with Endocrine Tissues
Authors: Haspel Martin V. , Onodera Takashi , Prabhakar Bellur S. , Horita Masakazu , Suzuki Hoshibumi , Notkins Abner Louis
Published: October 2006

Mice infected with reovirus type 1 develop an autoimmune polyendocrine disease. Spleen cells from these mice were fused with myeloma cells and the culture fluids were screened by indirect immunofluorescence for autoantibodies reactive with normal mouse tissues. A large panel of cloned, stable antibody-producing hybridomas has been obtained. Fourteen of the hybridomas make autoantibodies that react with cells in the islets of Langerhans, 24 with cells in the anterior pituitary, 11 with cells in gastric mucosa, and 5 with nuclei. Except for the antibodies to nuclei, the monoclonal autoantibodies are organ-specific. Some, however, show broad cross-species reactivity, recognizing similar antigenic determinants in mouse, rat, pig, and human organs, whereas others recognize determinants only in rodent tissues. Several of the antigens recognized by these monoclonal autoantibodies have been identified as hormones (for example, glucagon, growth hormone, and insulin).
Abnormal Ion Permeation Through Cystic Fibrosis Respiratory Epithelium
Authors: Knowles M. R. , Stutts M. J. , Spock A. , Fischer N. , Gatzy J. T. , Boucher R. C.
Published: October 2006

The epithelium of nasal tissue excised from subjects with cystic fibrosis exhibited higher voltage and lower conductance than tissue from control subjects. Basal sodium ion absorption by cystic fibrosis and normal nasal epithelia equaled the short-circuit current and was amiloride-sensitive. Amiloride induced chloride ion secretion in normal but not cystic fibrosis tissue and consequently was more effective in inhibiting the short-circuit current in cystic fibrosis epithelia. Chloride ion-free solution induced a smaller hyperpolarization of cystic fibrosis tissue. The increased voltage and amiloride efficacy in cystic fibrosis reflect absorption of sodium ions across an epithelium that is relatively impermeable to chloride ions.
Nuclear Magnetic Resonance Imaging of the Vitreous Body
Authors: González R. Gilberto , Cheng Hong-Ming , Barnett Patrick , Aguayo James , Glaser Bert , Rosen Bruce , Burt C. Tyler , Brady Thomas
Published: October 2006

Imaging with proton nuclear magnetic resonance is a valuable new tool for studying the vitreous body of the eye. It is particularly suited for the detection of vitreal liquefaction and intraocular hemorrhage because of the dependence of the signal on the physical environment of water. Conversely, the vitreous body provides a new model for studying changes in proton relaxation times of protein solutions in biological systems.
Structure of 3′ Terminal Region of Type II Human T Lymphotropic Virus: Evidence for New Coding Region
Authors: Haseltine William A. , Sodroski Joseph , Patarca Roberto , Briggs Debra , Perkins Dennis , Wong-Staal Flossie
Published: October 2006

The sequence of the 3′ terminus of the human T lymphotropic virus type II (HTLV-II) was determined and compared to the corresponding sequence of HTLV-I. The 1557-nucleotide-long sequence can be divided into a 5′ region that is not conserved between the two viruses, and a 3′, 1011-nucleotide-long region that is highly conserved and that corresponds precisely with a long open reading frame for both HTLV-I and -II. The proteins that could be encoded by these open reading frames have a molecular weight of about 38,000 and are closely related in primary amino acid sequence. The genomic structure in the 3′ region of HTLV was found to be similar to that of bovine leukemia virus.
Influence of Clonal Selection on the Expression of Immunoglobulin Variable Region Genes
Authors: Manser Tim , Huang Shu-Ying , Gefter Malcolm L.
Published: October 2006

The humoral immune response of the mouse to certain antigens is characterized by the dominant expression of a single or limited number of related, immunoglobulin variable region (V) structures by antibody-secreting lymphocytes. Such dominance could be due to preferred expression of these V regions in the B cell population prior to the immune response or could result from the action of selective or regulatory mechanisms during the immune response. Expression of a heavy chain variable region (V
H
) gene segment that partially encodes a V region structure that dominates the immune response to para-azophenylarsonate (Ars) in strain A mice was examined in the B cell population of Ars nonimmune mice. This V
H
gene segment participates in encoding several hundred thousand different V region structures expressed in this B cell population. The immune system is therefore capable of recurrently selecting a single V region structure from such a repertoire for dominant expression by antibody-secreting lymphocytes during an immune response.
The Respiratory Sinus Arrhythmia: A Measure of Cardiac Age
Authors: Hrushesky W. J. M. , Fader D. , Schmitt O. , Gilbertsen V.
Published: October 2006

A method developed for quantifying respiratory sinus arrhythmia (RSA) during voluntary cardiorespiratory synchronization relies on computer-assisted rhythmometric cosinor analysis of instantaneous heart rate data. The RSA was present in all subjects tested, even those at advanced ages. The amplitude of the RSA falls approximately 10 percent per decade. An individual with a transplanted heart and one with severe diabetic neuropathy each had resting RSA values that were normal for their ages. The shape and amplitude of the RSA during voluntary cardiorespiratory synchronization may reflect the suppleness of the heart and its response to rhythmically changing intrathoracic pressure and the subsequent ebb-and-flow of venous return. Our technology allows objective quantitative assessment of the biologic age of the heart and also the effect of any drug, disease, or behavior that affects the RSA.
Bone Cell Differentiation and Growth Factors
Authors: Urist Marshall R. , DeLange Robert J. , Finerman G. A. M.
Published: October 2006

Bone morphogenetic protein and bone-derived growth factors are biochemical tools for research on induced cell differentiation and local mechanisms controlling cell proliferation. Bone morphogenetic protein irreversibly induces differentiation of perivascular mesenchymal-type cells into osteoprogenitor cells. Bone-derived growth factors are secreted by and for osteoprogenitor cells and stimulate DNA synthesis. Bone generation and regeneration are attributable to the co-efficiency of bone morphogenetic protein and bone-derived growth factors.
Serologic Evidence of Chlamydial and Mycoplasmal Pharyngitis in Adults
Authors: Komaroff A. L. , Aronson M. D. , Pass T. M. , Ervin C. T. , Branch W. T. , Schachter J.
Published: October 2006

In a study of 763 adult patients we found serologic evidence of infection (a fourfold increase in antibodies) with
Chlamydia trachomatis
in 20.5 percent of the patients and with
Mycoplasma pneumoniae
in 10.6 percent, but with group A streptococcus (by culture) in only 9.1 percent. Pharyngitis, the most common problem for which patients seek medical care in the United States, may be caused by nonviral, potentially treatable organisms more often than had been suspected.
Interleukin 2 Regulates Expression of Its Receptor and Synthesis of Gamma Interferon by Human T Lymphocytes
Authors: Reem Gabrielle H. , Yeh Ning-Hsing
Published: October 2006

Interleukin 2 (IL-2) has an important role in the regulation of the expression of IL-2 receptors and the synthesis of gamma interferon (IFN-γ) by T lymphocytes. IL-2 is required for the optimum expression of IL-2 receptors on activated T lymphocytes and for maximum synthesis of IFN-γ in vitro. Dexamethasone, an immunosuppressant drug that inhibits IL-2 synthesis, diminished the expression of IL-2 receptors and the synthesis of IFN-γ. Anti-Tac, a monoclonal antibody known to prevent the binding of IL-2 to its receptor without inhibiting IL-2 synthesis, down-regulated the expression of the receptor and partially inhibited synthesis of IFN-γ. In a population of T lymphocytes prevented from synthesizing IL-2 by dexamethasone and incapable of using IL-2 as a result of blockage of IL-2 receptors by anti-Tac, the number of receptor-bearing cells and receptor density were diminished. Anti-Tac in combination with dexamethasone also exerted a synergistic effect on IFN-γ synthesis, inhibiting it almost completely. The inhibitory effect of dexamethasone IFN-γ synthesis may be of clinical importance, since IFN-γ activates macrophages and thereby triggers one of the defense mechanisms against bacterial infections.
Isolation and Structure of Bacterial Sex Pheromone, cPD1
Authors: Suzuki Akinori , Mori Masaaki , Sakagami Youji , Isogai Akira , Fujino Masahiko , Kitada Chieko , Craig Ronald A. , Clewell Don B.
Published: October 2006

The
Streptococcus faecalis
sex pheromone cPD1, which induces a mating response in cells harboring the conjugative plasmid pPD1, has been isolated and its structure determined. It was found to have a molecular weight of 912, and its amino acid sequence was H-Phe-Leu-Val-Met-Phe-Leu-Ser-Gly-OH. A synthetic octapeptide showed the same biological activity and chromatographic behavior as the isolated cPD1. Pheromone activity was detectable at a concentration of approximately 4 × 10
-11
M
.
Nuclear Localization and DNA Binding Properties of a Protein Expressed by Human c-
myc
Oncogene
Authors: Persson Håkan , Leder Philip
Published: October 2006

Antisera to the human cellular myc oncogene product were used to identify a human c-myc specific protein with a molecular weight of 65,000. Subcellular fractionation showed that the human c-myc protein is predominantly found in the cell nucleus. The p65K
c-myc
protein binds to double- and single-stranded DNA as measured by a DNA affinity chromatography assay.
Nucleosome Reconstruction via Phosphorus Mapping
Authors: Harauz George , Ottensmeyer F. P.
Published: October 2006

Electron spectroscopic imaging was combined with reconstruction algorithms to derive the three-dimensional structure of the nucleosome core particle to a resolution of 1.5 nanometers. Images of phosphorus distributions within individual nucleosomes were interpreted as projections of a supercoil of DNA. These were used to orient the corresponding individual nucleosome images, making it possible to reconstruct the entire nucleosome in three dimensions. The structure is consistent with known biochemical and biophysical data and explains site-specific nuclease sensitivity, although differing in part with other nucleosome models.
Modulation of the Metastatic Activity of Melanoma Cells by Laminin and Fibronectin
Authors: Terranova Victor P. , Williams Jeannette E. , Liotta Lance A. , Martin George R.
Published: October 2006

Metastatic mouse melanoma cells have a high affinity for the basement membrane and the ability to degrade it; these properties may allow tumor cells to invade the membrane and disseminate. In this study it was found that the metastatic potential of mouse melanoma cells varied when the cells were exposed in culture to fibronectin or laminin. After removal of fibronectin or exposure to laminin, the cells had an increased affinity for basement membrane collagen, were more invasive of basement membranes in vitro, and produced more lung colonies in vivo. These changes are correlated with and may be due to an increase in the laminin-binding capacity of the tumor cell surface.
Fluoride Directly Stimulates Proliferation and Alkaline Phosphatase Activity of Bone-Forming Cells
Authors: Farley John R. , Wergedal Jon E. , Baylink David J.
Published: October 2006

Fluoride is one of the most potent but least well understood stimulators of bone formation in vivo. Bone formation was shown to arise from direct effects on bone cells. Treatment with sodium fluoride increased proliferation and alkaline phosphatase activity of bone cells in vitro and increased bone formation in embryonic calvaria at concentrations that stimulate bone formation in vivo.
Pattern Formation by Cultured Human Epidermal Cells: Development of Curved Ridges Resembling Dermatoglyphs
Authors: Green Howard , Thomas Judith
Published: October 2006

In cultures made from disaggregated human epidermal cells, growth to a confluent cell layer is followed by the emergence of patterns resembling those of human dermatoglyphs. These patterns reflect intrinsic properties of keratinocytes. In vivo, only the epidermis of the volar surfaces forms patterns, but in culture, patterns are formed by epidermal cells from other sites as well. Patterns develop by a process of cell movement which first produces ridges and then curves the ridges into figures of increasing complexity, ultimately whorls.
Human Trophoblast-Lymphocyte Cross-Reactive (TLX) Antigens Define a New Alloantigen System
Authors: McIntyre John A. , Faulk W. Page , Verhulst Steven J. , Colliver Jerry A.
Published: October 2006

Antisera to human syncytiotrophoblast microvillous cell surface membranes from different placentas are cytotoxic for lymphocytes from some people but not others, demonstrating the presence of allotypic trophoblast-lymphocyte cross-reactive (TLX) antigens. Exploratory principal components factor analysis, performed on limited data consisting of 300 cytotoxic reactions produced by ten separate trophoblast antisera on a panel of lymphocytes from 30 random donors, suggested the presence of three distinct TLX antigen groupings. It is proposed that such TLX alloantigens are central in establishing maternal recognition and protection of the blastocyst, and that lack of recognition results in implantation failure and spontaneous abortion. These findings are compatible with contemporary results of immunotherapy to prevent recurrent spontaneous abortions, and their implications extend to other conditions of allogeneic coexistence, such as organ transplantation and the tumor-host relationship.
Decreased Oxidation of Labeled Glucose by Dissociated Brain Cells in the Presence of Fetal Bovine Serum
Authors: Tildon J. Tyson , Stevenson Joseph H.
Published: October 2006

The effect of serum on the rate of substrate oxidation by dissociated brain cells in vitro was examined. At a serum protein concentration of approximately 0.55 milligram per milliliter, oxidation of [6-
14
C]glucose to
14
CO
2
was decreased more than 50 percent. Oxidation of [3-
14
C]-3-hydroxybutyrate and [U-
14
C]glutamine was decreased much less. Serum from cows, rats, horses, and humans produced similar effects, as did serum from young and old animals and from both sexes. The effect on [6-
14
C]glucose oxidation was proportional to serum protein concentration, and significant inhibitory activity was obtained with dialyzed serum. Heating (80°C for 10 minutes) significantly reduced the inhibitory activity. These results suggest the presence of a factor in serum that can preferentially decrease glucose oxidation. Such a factor would have profound implications for metabolic regulation in vivo and for studies of cells in vitro in which serum is included in the growth medium.
Is There an Evoked Vascular Response?
Authors: Sandman Curt A. , O'Halloran James P. , Isenhart Robert
Published: October 2006

Event-related potentials of the brain are enhanced when stimulation is synchronized with diastolic phases of cerebral or cephalic pulse pressure waves. A cerebral vascular event has been found to be temporally consistent with the event-related potential. Averaged evoked vascular responses were measured with bioimpedance techniques from the brain and the arm. Changes in brain blood volume occurred 150 to 250 milliseconds after stimulation synchronized with diastolic but not systolic phases of the cerebral pulse pressure wave. The time course of this phenomenon defies the usually accepted characteristics of metabolic activity. The evoked vascular response may be a neurally mediated event in anticipation of altered metabolic demand, and it offers the possibility of measurement in real time.
Dynamic Structure of Membranes by Deuterium NMR
Authors: Smith Rebecca L. , Oldfield Eric
Published: October 2006

Progress in our understanding of the dynamic structure of membrane lipids and proteins has recently been made possible by the advent of high-field "solid-state" nuclear magnetic resonance spectroscopic studies of specifically deuterium-labeled systems. Major features of lipid and protein dynamics have been deduced.
G
M1
Ganglioside Treatment Facilitates Behavioral Recovery from Bilateral Brain Damage
Authors: Sabel Bernhard A. , Slavin Mary D. , Stein Donald G.
Published: October 2006

Adult rats with bilateral lesions of the caudate nucleus were treated with G
M1
ganglioside. Although animals injected with a control solution were severely impaired in their ability to learn a complex spatial task, those treated with ganglioside were able to learn spatial reversals.
Development of the Place Principle: Tonotopic Organization
Authors: Lippe William , Rubel Edwin W.
Published: October 2006

The tonotopic organization of brainstem auditory nuclei was compared in embryonic and hatchling chickens. In embryos, neurons at any given position in these nuclei were maximally sensitive to lower frequency sounds than the best frequency after hatching. This finding indicates that neurons are maximally stimulated by sounds of different frequencies as development proceeds and supports the hypothesis that during development there is a change in the spatial encoding of frequency along the cochlea.
Tumor Promotion by Phorbol Esters in Skin: Evidence for a Memory Effect
Authors: Fürstenberger Gerhard , Sorg Bernd , Marks Friedrich
Published: October 2006

By means of a two-stage promotion protocol in mouse epidermis with 12-
O
-tetradecanoylphorbol-13-acetate as first-stage promoter and 12-
O
-retinoylphorbol-13-acetate as second-stage promoter, the effects of the former that are critical and obligatory for tumor promotion were shown to be irreversible in nature for at least 8 weeks. The reversibility of tumor promotion was related to the second stage of promotion, reflecting the reversibility of epidermal hyperplasia induced by 12-
O
-tetradecanoylphorbol-13-acetate.
The Terminal Nerve: A New Chemosensory System in Vertebrates?
Authors: Demski Leo S. , Northcutt R. Glenn
Published: October 2006

Ganglion cells of the terminal nerve in goldfish are located in the olfactory nerve and bulb and send peripheral processes into the olfactory epithelium and central processes to the supracommissural nuclei of the telencephalon as well as to the retina. Correlations between terminal nerve projections and neurobehavioral studies suggest that the terminal nerve mediates responses to sex pheromones.
Red/Green Color Opponency at Detection Threshold
Authors: Thornton Jay E. , Pugh Edward N.
Published: October 2006

By means of visual stimulus without temporal or spatial edges, we have achieved better isolation of chromatic signals at detection threshold than has been reported previously. Under various states of adaptation, the spectral sensitivity of the chromatic mechanism detecting middle- and long-wavelength lights corresponds with that deduced from suprathreshold red/green hue equilibriums.
Inhibition of Tumor Promotion by a Biomimetic Superoxide Dismutase
Authors: Kensler Thomas W. , Bush Donna M. , Kozumbo Walter J.
Published: October 2006

A low molecular weight, lipophilic, copper coordination complex with superoxide dismutase-mimetic activity inhibited biochemical and biological actions of a tumor promoter in mouse epidermis. Such inhibitory effects implicate reactive oxygen species in the tumor promotion process.
Very Brief Visual Experience Eliminates Plasticity in the Cat Visual Cortex
Authors: Mower George D. , Christen William G. , Caplan Caren J.
Published: October 2006

Rearing cats in the dark extends the critical period for development of visual cortical neurons, which indicates that the experience of visual input is necessary to begin the developmental process. A single brief pulse of visual input (6 hours) during a period of dark-rearing eliminates delayed development in the visual cortex. Light therefore seems to rapidly trigger the developmental process, and once triggered, that process runs to completion in the absence of further input.
Ultrastructural Demonstration of Trypsin-Like Protease in Acrosomes of Sea Urchin Sperm
Authors: Green Jeffrey D. , Summers Robert G.
Published: October 2006

Two independent cytochemical techniques were used to demonstrate that a trypsin-like protease is bound to the acrosomal tubule of the sea urchin sperm. The enzyme is associated with bindin on the reacted acrosome and presumably functions in the early phases of fertilization.
Testosterone: A Major Determinant of Extragenital Sexual Dimorphism
Authors: Bardin C. Wayne , Catterall James F.
Published: October 2006

Sexual dimorphism in selected extragenital tissues is described with emphasis on the molecular basis of the differences. Testosterone rather than 5α -dihydrotestosterone appears to be the major intracellular androgen in organs other than skin and reproductive tract, but other steroid metabolites and their receptors are required to produce the diverse tissue differences observed in males and females. There is also evidence that multiple hormones from several endocrine glands are required to act in concert with androgens to produce and maintain their effects. Although many of the consequences of sexual dimorphism, such as body size and strength, have been evident for centuries, other differences between males and females such as disease incidence, response to drugs and toxins, and the metabolism and assimilation of dietary constituents have only recently been discovered.
Cholinergic Changes During Conditioned Suppression in Rats
Authors: Hingtgen J. N. , Smith J. E. , Shea P. A. , Aprison M. H. , Gaff T. M.
Published: October 2006

Levels of acetylcholine were significantly elevated in the telencephalon and diencephalon + mesencephalon of rats killed by near-freezing during conditioned suppression of food-reinforced lever pressing, whereas levels of serotonin, dopamine, and norepinephrine were not altered. These neurochemical changes were not seen in rats serving as controls for conditioning experience, activity levels, or stimulus presentation.
Cytoplasmic Inclusion Bodies in
Escherichia coli
Producing Biosynthetic Human Insulin Proteins
Authors: Williams Daniel C. , Van Frank Richard M. , Muth William L. , Burnett J. Paul
Published: October 2006

Escherichia coli
that has been genetically manipulated by recombinant DNA technology to synthesize human insulin polypeptides (A chain, B chain, or proinsulin) contains prominent cytoplasmic inclusion bodies. The amount of inclusion product within the cells corresponds to the quantity of chimeric protein formed by the bacteria. At peak production, the inclusion bodies may occupy as much as 20 percent of the
Escherichia coli
cellular volume.
The Chloride Cell: Definitive Identification as the Salt-Secretory Cell in Teleosts
Authors: Foskett J. Kevin , Scheffey Carl
Published: October 2006

Chloride-secreting isolated opercular membranes from the seawater-adapted teleost
Sarotherodon mossambicus
contain the several cell types also seen in the branchial epithelium. The vibrating probe technique has been used to localize conductance and chloride current specifically to the so-called chloride cells, thereby establishing these cells definitively as the extrarenal salt-secretory cells.
Human Cell Hybrids: Analysis of Transformation and Tumorigenicity
Authors: Stanbridge Eric J. , Der Channing J. , Doersen Claus-Jens , Nishimi Robyn Y. , Peehl Donna M. , Weissman Bernard E. , Wilkinson Joyce E.
Published: October 2006

Intraspecific human-human cell hybrids provide a stable model system with which to investigate the genetic control of transformed and tumorigenic phenotypes. Using this system it has been shown that these phenotypes are under separate genetic control. Furthermore, the tumorigenic phenotype can be complemented by fusion of different tumorigenic cells, resulting in nontumorigenic hybrids. This system also provides information on the control of differentiated function. Molecular cytogenetic techniques should reveal the nature of the chromosomal control of neoplastic transformation.
Bronchoconstrictor Effects of Leukotriene C in Humans
Authors: Weiss J. Woodrow , Drazen Jeffrey M. , Coles Nancy , McFadden E. Regis , Weller Peter F. , Corey E. J. , Lewis Robert A. , Austen K. F.
Published: October 2006

Maximum expiratory flow rate at 30 percent of vital capacity above residual volume served as an index of airway obstruction in comparing the effects of leukotriene C and histamine administered by aerosol to five normal persons. Leukotriene C was 600 to 9500 times more potent than histamine on a molar basis in producing an equivalent decrement in the maximum expiratory flow rate at 30 percent of vital capacity above residual volume. The leukotriene C response was slow in onset and prolonged, reminiscent of the effects of aerosol allergen challenge in asthmatic allergic subjects.
Nerve Fiber Growth on Defined Hydrogel Substrates
Authors: Carbonetto S. T. , Gruver M. M. , Turner D. C.
Published: October 2006

Cultured neurons become attached to hydrogel substrates prepared from 2-hydroxyethylmethacrylate but grow few nerve fibers unless fibronectin, collagen, or nerve growth factor is incorporated into the hydrogel. Antibodies to fibronectin inhibit nerve fiber growth on hydrogels containing fibronectin, which suggests that growing neurons interact directly with proteins trapped in the hydrogel. The adhesive requirements for attachment of neurons appear distinct and possibly less specific than those for fiber growth. Defined hydrogel substrates offer a controlled method for analyzing complex substrates that support nerve fiber growth and neuronal differentiation.
In Vivo Activation of Zoxazolamine Metabolism by Flavone
Authors: Lasker J. M. , Huang M.-T. , Conney A. H.
Published: October 2006

The metabolism of zoxazolamine to 6-hydroxyzoxazolamine by liver microsomes from neonatal rats is stimulated severalfold by the in vitro addition of flavone, a naturally occurring compound found in several plant species. The intraperitoneal injection of flavone into neonatal rats causes an immediate severalfold stimulation in the rate of total body metabolism of simultaneously administered zoxazolamine. This is the first demonstration of stimulation of oxidative drug metabolism in vivo by a xenobiotic that is an activator of hepatic microsomal monooxygenases in vitro.
An Enzymatic System for Removing Heparin in Extracorporeal Therapy
Authors: Langer Robert , Linhardt Robert J. , Hoffberg Steven , Larsen Annette K. , Cooney Charles L. , Tapper David , Klein Michael
Published: October 2006

The need to fully heparinize patients undergoing extracorporeal therapy often leads to hemorrhagic complications. To enable heparinization of only the extracorporeal circuit, a blood filter containing immobilized heparinase was developed. This filter degraded 99 percent of heparin's anticoagulant activity within minutes in both canine and human blood.
Radiosensitization of Hypoxic Tumor Cells by Depletion of Intracellular Glutathione
Authors: Bump Edward A. , Yu Ning Y. , Brown J. Martin
Published: October 2006

Depletion of glutathione in Chinese hamster ovary cells in vitro by diethyl maleate resulted in enhancement of the effect of x-rays on cell survival under hypoxic conditions but not under oxygenated conditions. Hypoxic EMT6 tumor cells were similarly sensitized in vivo. The action of diethyl maleate is synergistic with the effect of the electron-affinic radiosensitizer misonidazole, suggesting that the effectiveness of misonidazole in cancer radiotherapy may be improved by combining it with drugs that deplete intracellular glutathione.
Force-Sensitive Interneurons in the Spinal Cord of the Cat
Authors: Cleland Corey L. , Rymer W. Zev , Edwards Frank R.
Published: October 2006

The input-output properties of interneurons mediating spinal reflexes were investigated by extracellularly recording the response of interneurons to excitation from muscle receptors in the ankle extensor muscles of decerebrated, spinal cats. A population of interneurons in the intermediate region of the spinal cord is potently excited by increases in muscle force. Unlike the discharge of Golgi tendon organs, which accurately encodes moment-to-moment variations in the force of a single muscle, the discharge of these interneurons depends in a dynamic and usually nonlinear way on the force in several muscles. Powerful input from unidentified mechanoreceptors in muscle, presumably free nerve endings, is at least partly responsible for these properties. These force-sensitive interneurons are more likely to mediate clasp knife-type inhibition than simple negative force feedback.
Neurotoxin-Specific Immunoglobulins Accelerate Dissociation of the Neurotoxin-Acetylcholine Receptor Complex
Authors: Boulain Jean-Claude , Ménez André
Published: October 2006

Toxin isolated from cobra venom and labeled with tritium was incubated with membranes rich in acetylcholine receptors. The amount of toxin bound to the receptors was determined and the kinetics of dissociation of the receptor-toxin complex was followed. Addition of an excess of horse antiserum to the venom resulted in a significant acceleration of the dissociation reaction. Similarly, a monoclonal antibody against the toxin accelerated dissociation of the receptor-toxin complex. The results indicate that specific antibody binding destabilizes the toxin-receptor complex.
Hippocampal Aging and Adrenocorticoids: Quantitative Correlations
Authors: Landfield P. W. , Waymire J. C. , Lynch G.
Published: October 2006

Altered neural-endocrine relations have been proposed as factors in mammalian aging. In the same rats from three age groups we quantified astrocyte reactivity in hippocampus, performed radioimmunoassays for plasma adrenocorticoids, and measured adrenal weight. These variables were correlated in individual animals and generally increased with age. The findings are consistent with recent hypotheses that endocrine levels are related to brain aging, either as cause or effect.
Continuous Lines of Basophil/Mast Cells Derived from Normal Mouse Bone Marrow
Authors: Nagao Kenji , Yokoro Kenjiro , Aaronson Stuart A.
Published: October 2006

Nonadherent tissue culture cell lines were established from normal bone marrow of a variety of mouse strains. The lines possessed morphological and histochemical markers of the basophil/mast cell and contained committed stem cells for metachromatic cells. Their derivation from normal marrow and their lack of tumorigenicity despite long-term culture makes these cell lines potentially important for studies of the mechanisms of allergic reactions and inflammation as well as the differentiation pathways involving this subset of hematopoietic cells.
Inflammatory Toxin from
Mycoplasma bovis
: Isolation and Characterization
Authors: Geary Steven J. , Tourtellotte Mark E. , Cameron J. A.
Published: October 2006

An inflammatory toxin was extracted from
Mycoplasma bovis
with 75 percent aqueous ethanol. The toxin is a complex polysaccharide composed of glucose, glucosamine or galactosamine, and a heptose, is heat-stable, devoid of protein and lipid, and has a molecular weight of 73,000. The holotoxin in the cell membrane is a glycoprotein; however, it is the polysaccharide portion that is toxic. This inflammatory toxin increases vascular permeability and is capable of activating complement. Infusion of 0.9 milligram of toxin into the bovine udder resulted in the characteristic eosinophilic mastitis produced by
Mycoplasma bovis
.
Human Homing: An Elusive Phenomenon
Authors: Gould James L. , Able Kenneth P.
Published: October 2006

Recent experiments suggest an ability of blindfolded humans transported from home to indicate the direction of displacement. Attempts to replicate these results have been unsuccessful.
Species-Typical Behavior of Hamsters Deprived from Birth of the Neocortex
Authors: Murphy Michael R. , MacLean Paul D. , Hamilton Sue C.
Published: October 2006

Hamsters deprived from birth of the neocortex developed normally and displayed the usual hamster-typical behavioral patterns. With the additional concurrent destruction of midline limbic convolutions (cingulate and underlying dorsal hippocampal), there were deficits in maternal behavior and a lack of development of play behavior. These findings demonstrate in a rodent (i) that the striatal complex and limbic system, along with the remaining neuraxis, are sufficient for giving expression to a wide range of unlearned forms of species-typical behavior and (ii) that midline limbic structures are required for the expression of play behavior and the integrated performance of maternal behavior.