bluuebunny/crossref_metadata_2025 huggingface dataset:
Interferon-Resistant Cell Line Lacks Fatty Acid Cyclooxygenase Activity
Authors: Chandrabose Kuttikkat A. , Cuatrecasas Pedro , Pottathil Raveendran , Lang David J.
Published: October 2006

A clone of L1210 mouse leukemia cells selected for resistance to both the antiviral and anticellular properties of mouse interferon were essentially devoid of fatty acid cyclooxygenase activity. Experiments in which broken cell preparations were mixed or the two cell types were cultivated together failed to indicate the presence of a diffusible enzyme inhibitor. Fatty acid lipoxygenase activity of similar magnitude was detectable in both cell types. A selective impairment of fatty acid cyclooxygenase in interferon-resistant cells is consistent with recently described data suggesting that this enzyme may play a crucial role in mediating the antiviral and anticellular effects of interferon.
Perivascular Meningeal Projections from Cat Trigeminal Ganglia: Possible Pathway for Vascular Headaches in Man
Authors: Mayberg Marc , Langer Robert S. , Zervas Nicholas T. , Moskowitz Michael A.
Published: October 2006

Peroxidase-containing cell bodies were found in the ipsilateral trigeminal ganglia after horseradish peroxidase was applied to the proximal segment of the middle cerebral artery in seven cats. Cell bodies containing the enzyme marker were located among clusters of cells that project via the first division. The existence of sensory pathways surrounding large cerebral arteries provides an important neuroanatomical explanation for the hemicranial distribution of headaches associated with certain strokes and migraine.
Thyroidectomy Increases Rat Hepatic Ferritin Iron
Authors: Winkelmann John C. , Mariash Cary N. , Towle Howard C. , Oppenheimer Jack H.
Published: October 2006

Studies of the hepatic polysome profiles of hypothyroid rats demonstrated contamination of the free monosome peak with ferritin. This led to the serendipitous observation of a fivefold increase in ferritin iron in livers and kidneys of hypothyroid rats.
Bodian's Silver Method Stains Neurofilament Polypeptides
Authors: Gambetti P. , Autilio Gambetti L. , Papasozomenos S. Ch.
Published: October 2006

Bodian's silver method was used to stain polypeptides of rat spinal cord or peripheral nerve separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The bands corresponding to the three polypeptide subunits of the neurofilaments were intensely impregnated. Two other polypeptides were stained inconsistently and less intensely. The tubulin band was stained weakly or not at all; other polypeptides, including glial fibrillary acidic protein, actin, and vimentin, remained unstained. This novel application of Bodian's method provides indirect proof that neurofilaments are the neuronal subcellular structure stained by the technique.
A Nonenzymatic RNA Polymerase Model
Authors: Inoue T. , Orgel L. E.
Published: October 2006

Polynucleotide templates containing C (cytidine) as the major component facilitate the synthesis of oligonucleotides from mixtures of the activated mononucleotide derivatives (as indicated by structure 1 in the text). A nucleotide is incorporated into oligomeric products if and only if its complement is present in the template. The reaction has a high fidelity and produces products with mean chain lengths of six to ten nucleotides. Bases other than guanosine are incorporated within oligomers or at their 3′ termini, but rarely at their 5′ termini.
Tunicamycin Enhances the Antiviral and Anticellular Activity of Interferon
Authors: Maheshwari Radha K. , Sreevalsan T. , Silverman Robert H. , Hay John , Friedman Robert M.
Published: October 2006

The inhibitory effects of interferon on virus multiplication and cell growth are significantly enhanced by treatment with tunicamycin. Potentiation of antiviral activity was found only with enveloped viruses and not with nonbudding viruses. Changes in the plasma membrane of treated cells may account for this effect, since enveloped viruses bud from the cell surface as a terminal step.
A Monoclonal Antibody to Limbic System Neurons
Authors: Levitt Pat
Published: October 2006

A monoclonal antibody produced against hippocampal cell membranes labeled the surface of neurons in the rat limbic system. With a few exceptions, all nonlimbic components were unstained. This specific distribution of immunopositive neurons provides strong evidence of molecular specificity among functionally related neurons in the mammalian brain and supports the concept of a limbic system.
A Labile Phosphodiester Bond at the Ligation Junction in a Circular Intervening Sequence RNA
Authors: Zaug Arthur J. , Kent Jeffrey R. , Cech Thomas R.
Published: October 2006

The excised intervening sequence of the
Tetrahymena
ribosomal RNA precursor mediates its own covalent cyclization in the absence of any protein. The circular molecule undergoes slow reopening at a single phosphodiester bond, the one that was formed during cyclization. The resulting linear molecule has 5′-phosphate and 3′-hydroxyl termini; these are unusual products for RNA hydrolysis but are typical of the other reactions mediated by this molecule. The reopened circle retains cleavage-ligation activity, as evidenced by its ability to undergo another round of cyclization and reopening. The finding that an RNA molecule can be folded so that a specific phosphate can be strained or activated helps to explain how the activation energy is lowered for RNA self-splicing. The proposed mechanisms may be relevant to several other RNA cleavage reactions that are RNA-mediated.
Growth Hormone-Releasing Factor Stimulates Pancreatic Enzyme Secretion
Authors: Pandol Stephen J. , Seifert Hans , Thomas Marjorie W. , Rivier Jean , Vale Wylie
Published: October 2006

Growth hormone-releasing factors (GRF's) from two human pancreatic tumors (hpGRF's) that caused acromegaly and from the rat hypothalamus (rhGRF) were recently isolated and characterized. Although these peptides are potent growth hormone secretagogues, they have not until now been described to have actions outside the pituitary. These GRF's were shown to stimulate digestive enzyme secretion from an exocrine pancreatic preparation in vitro, rhGRF being more than 100 times as potent as hpGRF. Adenosine 3′,5′-monophosphate mediates this action of the GRF's.
Measurement of Myelin Sheath Resistances: Implications for Axonal Conduction and Pathophysiology
Authors: Funch Paul G. , Faber Donald S.
Published: October 2006

As commonly understood, the myelin sheath of axons insulates the internodal axolemma and essentially restricts transmembrane currents to nodal regions. However, recordings obtained from within the myelin sheath showed that its apparent resistance to current generated by action potentials is similar in magnitude to that of the internodal axolemma. This suggests that the sheath does not appreciably limit transmembrane current flow, presumably because there is a longitudinal shunt under the myelin and through the paranodal region. Thus, in some demyelinating diseases and other axonopathies, the safety factor for impulse conduction may be lowered by a loosening or a reduction in the number of paranodal axoglial junctions.
Suppressor T Cell Action Inhibits the Expression of an Excluded Immunoglobulin Gene
Authors: Parslow Tristram G. , Milburn Gary L. , Lynch Richard G. , Granner Daryl K.
Published: October 2006

Cells of the murine plasmacytoid line MOPC-315 synthesize two distinct immunoglobulin light chains: a normal λ
II
protein, which is incorporated into secretory and surface-bound immunoglobulin, and a truncated, nonfunctional λ
I
protein found only in the cytoplasm. Idiotype-specific suppressor T lymphocytes selectively inhibit the expression of both λ
II
- and λ
I
-specific messenger RNA by MOPC-315 cells. This finding demonstrates that phenotypically excluded light chain genes can be subject to immunoregulatory control and suggests that the expression of divergent λ isotypes may be coordinately regulated in immunoglobulin-secreting cells.
Mirex in the Environment: Its Degradation to Kepone and Related Compounds
Authors: Carlson D. A. , Konyha K. D. , Wheeler W. B. , Marshall G. P. , Zaylskie R. G.
Published: October 2006

The chlorocarbon mirex undergoes slow, successive loss of chlorine in the field to a series of related compounds that had lost one or more chlorine atoms. Soil samples were recovered 12 years after treatment at 1 part per million (ppm), and ant bait was recovered 5 years after an aircraft crash. As much as 50 percent of the original mirex was recovered at levels of about 0.5 and 640 ppm, respectively. Kepone was present at levels of 0.02 ppm in soil and 10 ppm in the bait or up to 10 percent of the recovered mirex, as determined by combined techniques of chromatography and mass spectrometry. This constitutes the first observation of the degradation of mirex in nature, and demonstrates a pathway for its eventual disappearance from the environment.
Amino Acid Acylation: A Mechanism of Nitrogen Excretion in Inborn Errors of Urea Synthesis
Authors: Brusilow Saul , Tinker James , Batshaw Mark L.
Published: October 2006

Treatment of a patient deficient in carbamyl phosphate synthetase with benzoate or phenylacetic acid resulted in an increase in urinary nitrogen, which could be accounted for by the respective amino acid acylation product, hippurate or phenylacetylglutamine. Benzoate treatment of four hyperammonemic comatose patients led to clinical improvement and a return of plasma ammonium levels toward normal.
Properties of a Normal Mouse Cell DNA Sequence (sarc) Homologous to the src Sequence of Moloney Sarcoma Virus
Authors: Oskarsson Marianne , McClements William L. , Blair Donald G. , Maizel J. V. , Vande Woude George F.
Published: October 2006

A 15.0-kilobase (kb) Eco RI DNA fragment from normal mouse Balb/c genomic DNA that contains sequences (sarc) homologous to the acquired cell sequences (src) of Moloney sarcoma virus (MSV) has been cloned in phage λ. The sarc region (1.2 to 1.3 kb) of the 15.0-kb cell fragment is indistinguishable from the src region of two isolates of MSV as judged by heteroduplex and restriction endonuclease analyses. The cellular sequences flanking sarc show no homology to other MSV sequences. Whereas cloned subgenomic portions of MSV that contain src transformed NIH-3T3 cells in vitro, the cloned sarc fragment is inactive.
Recombination of Dispersed Repeated DNA Sequences in Yeast
Authors: Scherer Stewart , Davis Ronald W.
Published: October 2006

Yeast transformation can be used to insert new sequence arrangements into a variety of chromosomal locations by homologous recombination. These newly inserted sequences can recombine with similar sequences located on other chromosomes. In these events, information is duplicated without being lost at the site from which it is derived. Similar mechanisms might be utilized by cells to provide new functions during development or differentiation.
Asymmetry of the Acetylcholine Channel Revealed by Quaternary Anesthetics
Authors: Horn Richard , Brodwick Malcolm S. , Dickey W. Daryl
Published: October 2006

Tissue-cultured rat myoballs were examined electrophysiologically with a suction pipette, which was used for voltage clamping and internal perfusion. The lidocaine derivative QX-314 caused a time- and membrane potential-dependent block of acetylcholine-induced current only when applied from the extracellular membrane surface. The same compound caused a use-dependent block of the sodium channel only from the intracellular membrane surface. These experiments demonstrate a fundamental asymmetry of the acetylcholine receptor-channel complex.
Adrenocorticotropic Hormone May Be Transported Directly from the Pituitary to the Brain
Authors: Bergland R. , Blume H. , Hamilton A. , Monica P. , Paterson R.
Published: October 2006

Experiments were designed to test the hypothesis that pituitary hormones may be delivered directly to the brain. Concentrations of adrenocorticotropic hormone (ACTH) in the plasma were determined in blood samples obtained simultaneously from the carotid artery, the sagittal sinus, and the jugular vein of three awake sheep. Seizures were induced electrically to stimulate ACTH secretion, and at precise intervals thereafter several simultaneous comparisons were made in each animal. In many of the post-seizure comparisons, the ACTH plasma concentrations within the sagittal sinus exceeded those within the carotid artery as well as those within the jugular vein, indicating that this hormone was released from the pituitary and carried directly through capillary beds of brain to the venous blood within the sagittal sinus. The experiment was repeated in one hypophysectomized sheep and, in this animal, ACTH concentration in the plasma was reduced, but that in the sagittal sinus still was elevated after the seizure, an indication that some ACTH (or ACTH-like material) was released from the brain itself.
Anticonvulsants Specific for Petit Mal Antagonize Epileptogenic Effect of Leucine Enkephalin
Authors: Snead O. Carter , Bearden Larry J.
Published: October 2006

The anticonvulsants ethosuximide, sodium valproate, and trimethadione that are specific for petit mal epilepsy abolished in rats the electrical seizure activity and behavioral abnormalities produced by leucine enkephalin, whereas phenobarbital and phenytoin had no effect. The dose-response curve for naloxone against seizure activity induced by leucine enkephalin was the same as that in γ-hydroxybutyrate-induced petit mal. These data indicate that the epileptic properties of leucine enkephalin are petit mal-like and raise the possibility of involvement of enkephalinergic systems in petit mal epilepsy.
Evidence for Homologous Actions of Pro-Opiocortin Products
Authors: Walker J. Michael , Akil Huda , Watson Stanley J.
Published: October 2006

α-Melanocyte-stimulating hormone (α-MSH), a modified fragment of adrenocorticotropic hormone, derives from the same biosynthetic route as β-endorphin and is stored by the same arcuate neurons. Microinjection of α-melanocyte-stimulating hormone and several related peptides into the periaqueductal gray matter significantly reduced responsiveness to pain and had a behavioral profile similar to that produced by β-endorphin.
Autoradiographic Image Intensification: Applications in Medical Radiography
Authors: Askins Barbara S.
Published: October 2006

The image of an 80 to 90 percent underexposed medical radiograph can be increased to readable density and contrast by autoradiographic image intensification. The technique consists of combining the image silver of the radiograph with a radioactive compound, thiourea labeled with sulfur-35, and then making an autoradiograph from the activated negative.
Regulation of Cutaneous Previtamin D
3
Photosynthesis in Man: Skin Pigment Is Not an Essential Regulator
Authors: Holick M. F. , MacLaughlin J. A. , Doppelt S. H.
Published: October 2006

When human skin was exposed to simulated solar ultraviolet radiation, epidermal 7-dehydrocholesterol was converted to previtamin D
3
. During prolonged exposure to simulated solar ultraviolet radiation, the synthesis of previtamin D
3
reached a plateau at about 10 to 15 percent of the original 7-dehydrocholesterol content, and previtamin D
3
was photoisomerized to two biologically inert isomers, lumisterol
3
and tachysterol
3
. Increases either in skin melanin concentration or in latitude necessitated increases in the exposure time to simulated solar ultraviolet radiation required to maximize the formation, but not the total content, of previtamin D
3
. In order of importance, the significant determinants limiting the cutaneous production of previtamin D
3
are (i) photochemical regulation, (ii) pigmentation, and (iii) latitude.
Epstein-Barr Viral DNA: Infectivity for Human Placental Cells
Authors: Miller George , Grogan Elizabeth , Heston Lee , Robinson James , Smith Douglas
Published: October 2006

Purified DNA of Epstein-Barr virus (EBV) is regularly infectious by means of the "calcium" method of transfection. Cultured human placental cells exposed to EBV DNA of two transforming strains, FF41 and B95, produce virus that is capable of converting normal B lymphocytes into established cell lines. After treatment with EBV (FF41) DNA and EBV (HR-1) DNA the placental cells display antigens associated with the productive viral cycle. The placental cells have not developed foci or other signs of morphologic transformation.
Three Distinct Genes in Human DNA Related to the Transforming Genes of Mammalian Sarcoma Retroviruses
Authors: Wong-Staal Flossie , Dalla-Favera Riccardo , Franchini Genoveffa , Gelmann Edward P. , Gallo Robert C.
Published: October 2006

Southern blot hybridization was used to identify human and other vertebrate DNA sequences that were homologous to cloned DNA fragments containing the oncogenic nucleic acid sequences of three different type C mammalian retroviruses (simian sarcoma virus, the Snyder-Theilen strain of feline sarcoma virus, and the Harvey strain of murine sarcoma virus). Each
onc
gene counterpart has a single genetic locus, which probably contains non-
onc
intervening sequences. The human DNA sequences may represent genes important to cell growth or cell differentiation, or both. Their identification and isolation may allow elucidation of their role in these processes and in neoplasias.
Molecular and Cellular Mechanisms of Leukocyte Chemotaxis
Authors: Snyderman Ralph , Goetzl Edward J.
Published: October 2006

The application of modern scientific methods to the study of leukocyte function has begun to reveal the molecular and cytostructural bases of the chemotactic responses of these cells. Leukocyte chemotaxis is initiated by the binding of chemoattractants to distinct plasma membrane receptors; this binding alters transmembrane potential and activates ionic fluxes. The subsequent sequence of metabolic processes leads to a rearrangement of cytoskeletal elements that is manifested by orientation and migration of the cells toward the source of the chemotactic gradient.
Lithium Increases Serotonin Release and Decreases Serotonin Receptors in the Hippocampus
Authors: Treiser Susan L. , Cascio Caren S. , O'Donohue Thomas L. , Thoa Nguyen B. , Jacobowitz David M. , Kellar Kenneth J.
Published: October 2006

The effects of long-term lithium administration on pre- and postsynaptic processes involved in serotonergic neurotransmission were measured in rat hippocampus and cerebral cortex. Long-term lithium administration increased both basal and potassium chloride-stimulated release of endogenous serotonin from the hippocampus but not from the cortex. Serotonergic receptor binding was reduced in the hippocampus but not in the cortex. These results suggest a mechanism by which lithium may stabilize serotonin neurotransmission.
Multiple Opiate Receptors: Alcohol Selectively Inhibits Binding to Delta Receptors
Authors: Hiller Jacob M. , Angel Lloyd M. , Simon Eric J.
Published: October 2006

The addition of ethanol or other aliphatic alcohols to rat brain membranes strongly inhibits binding of enkephalins at concentrations at which little inhibition of opiate alkaloids is seen. Inhibition is reversible, and potency increases with chain length of the alcohol. The results suggest that δ receptors are considerably more sensitive to alcohols than μ receptors. This is the first demonstration of selective inhibition of one of the postulated classes of opiate receptors by a reagent that is not a ligand for the receptor.
Brain Aging Correlates: Retardation by Hormonal-Pharmacological Treatments
Authors: Landfield P. W. , Baskin R. K. , Pitler T. A.
Published: October 2006

Mid-aged rats were either adrenalectomized and chronically maintained, or left intact and treated daily for a 9- to 10-month period with a potent analog of the peptide adrenocorticotropin (residues 4 to 9), which has some stimulant properties, or with the neural stimulant pentylenetetrazole. All three treatments reduced hippocampal morphologic correlates of brain aging (neuronal loss, glial reactivity). The pentylenetetrazole and peptide treatments also improved reversal learning. These results suggest that certain endogenous peptides, with stimulant properties, may also exert long-term, trophic effects on brain structure and function.
Group B Erythrocytes Enzymatically Converted to Group O Survive Normally in A, B, and O Individuals
Authors: Goldstein Jack , Siviglia Geraldine , Hurst Rosa , Lenny Leslie , Reich Lilian
Published: October 2006

With an α-galactosidase, B erythrocytes can be converted to blood group O under conditions that neither impair their viability in vitro nor affect their ability to survive normally after transfusion to individuals of groups O, A, and B. Such an approach has the potential for producing enzymatically converted group O cells for use in transfusion therapy. It should also be possible to convert A cells to group O by using the appropriate α-
N
-acetylgalactosaminidase.
Different Synaptic Location of Mianserin and Imipramine Binding Sites
Authors: Brunello N. , Chuang D. M. , Costa E.
Published: October 2006

The high-affinity binding sites for mianserin and imipramine appear to be located in different neurons of rat brain. Studies in which lesions were produced with 5,7-dihydroxytryptamine and other studies in which the 5-hydroxytryptamine content was decreased withp-chlorophenylalanine indicate that some of the imipramine binding sites are on serotonin axon terminals and others are on nonserotonergic synapses. The sites that bind mianserin are on postsynaptic serotonin sites as well as on synapses of other neuronal systems.
Oxytocin Receptors and Human Parturition: A Dual Role for Oxytocin in the Initiation of Labor
Authors: Fuchs Anna-Riitta , Fuchs Fritz , Husslein Peter , Soloff Melvyn S. , Fernström Martha J.
Published: October 2006

The concentration of oxytocin receptors increased in the myometrium of pregnant women and reached maximum levels in early labor. Concentrations of oxytocin receptors were also high in the decidua and reached a maximum at parturition. In vitro, prostaglandin production by the decidua, but not by the myometrium, was increased by the addition of oxytocin. Oxytocin may therefore stimulate uterine contractions by acting both directly on the myometrium and indirectly on decidual prostaglandin production. Oxytocin receptors are probably crucial for the onset of human labor, and the stimulus for the increase in uterine prostaglandins may be oxytocin originating from the fetus.
Discrimination of Intermediate Sounds in a Synthetic Call Continuum by Female Green Tree Frogs
Authors: Gerhardt H. Carl
Published: October 2006

Male
Hyla cinerea
produce two distinctive calls. Acoustically intermediate calls are rare. Females discriminate between synthetic intermediates that differ by one cycle of amplitude modulation (50 per second). Processing appears to be continuous. The tree frog's auditory system thus provides a wide margin for the discrimination of its two principal signals.
Benzodiazepine Receptor-Mediated Experimental "Anxiety" in Primates
Authors: Ninan Philip T. , Insel Thomas M , Cohen Robert M. , Cook James M. , Skolnick Phil , Paul Steven M.
Published: October 2006

The ethyl ester of β-carboline-3-carboxylic acid has a high affinity for benzodiazepine receptors in the brain. In the rhesus monkey this substance produces an acute behavioral syndrome characterized by dramatic elevations in heart rate, blood pressure, plasma cortisol, and catecholamines. The effects are blocked by benzodiazepines and the specific benzodiazepine receptor antagonist Ro 15-1788. The benzodiazepine receptor may consist of several subsites or functional domains that independently recognize agonists, antagonists, or "active" antagonists such as β-carboline-3-carboxylic acid ethyl ester. These results suggest that the benzodiazepine receptor is involved in both the affective and physiological manifestations of anxiety, and that the administration of β-carboline-3-carboxylic acid ethyl ester to monkeys may provide a reliable and reproducible animal model of human anxiety.
A Functional Role for an Opiate System in Snail Thermal Behavior
Authors: Kavaliers Martin , Hirst Maurice , Teskey G. Campbell
Published: October 2006

The terrestrial snailCepaea nemoralis, when placed on a 40°C hot plate, lifts the anterior portion of its foot. The latency of this response is influenced by morphine and by naloxone in a dose-dependent and time-dependent manner. Morphine increases the time taken to respond, whereas naloxone reduces it. Furthermore, naloxone abolishes the effect of morphine. These results indicate that an opiate system may have a role in this behavior, which resembles that reported in vertebrates.
Systemic Cholinergic Agents Induce Seizures and Brain Damage in Lithium-Treated Rats
Authors: Honchar Michael P. , Olney John W. , Sherman William R.
Published: October 2006

Administration of pilocarpine or physostigmine to rats treated with lithium chloride produced sustained limbic seizures, widespread brain damage, and increased concentrations of D-
myo
-inositol-1-phosphate (a metabolite of the phosphoinositides, lipids involved in membrane receptor function) in the brain. The syndrome was preventable with atropine. The physostigmine doses and concentrations of blood lithium that caused the syndrome are similar to those considered appropriate for psychiatric chemotherapy.
Leukotrienes: Mediators of Immediate Hypersensitivity Reactions and Inflammation
Authors: Samuelsson Bengt
Published: October 2006

Arachidonic acid plays a central role in a biological control system where such oxygenated derivatives as prostaglandins, thromboxanes, and leukotrienes are mediators. The leukotrienes are formed by transformation of arachidonic acid into an unstable epoxide intermediate, leukotriene A4, which can be converted enzymatically by hydration to leukotriene B4, and by addition of glutathione to leukotriene C4. This last compound is metabolized to leukotrienes D4and E4by successive elimination of a γ-glutamyl residue and glycine. Slow-reacting substance of anaphylaxis consists of leukotrienes C4, D4, and E4. The cysteinyl-containing leukotrienes are potent bronchoconstrictors, increase vascular permeability in postcapillary venules, and stimulate mucus secretion. Leukotriene B4causes adhesion and chemotactic movement of leukocytes and stimulates aggregation, enzyme release, and generation of superoxide in neutrophils. Leukotrienes C4, D4, and E4, which are released from the lung tissue of asthmatic subjects exposed to specific allergens, seem to play a pathophysiological role in immediate hypersensitivity reactions. These leukotrienes, as well as leukotriene B4, have pro-inflammatory effects.
Identity of HeLa Cell Determinants Acquired by Vesicular Stomatitis Virus with a Tumor Antigen
Authors: Little Lynn M. , Zavada Jan , Der Channing J. , Huang Alice S.
Published: October 2006

Growth of vesicular stomatitis virus (VSV) in HeLa cells results in progeny containing non-VSV antigens with a molecular weight around 75,000. The non-VSV antigens were detected by antiserums to HeLa cell determinants. These antiserums precipitate whole virions but do not neutralize them. Because one of the antiserums is directed to a tumor-specific surface antigen of HeLa cells, it appears that VSV specifically acquires such antigens during its passage through human tumor cells.
Vasoactive Intestinal Peptide Alters Membrane Potential and Cyclic Nucleotide Levels in Retinal Horizontal Cells
Authors: Lasater Eric M. , Watling Keith J. , Dowling John E.
Published: October 2006

Vasoactive intestinal peptide stimulated the synthesis of adenosine 3′,5′-monophosphate in fractions of isolated carp horizontal cells. When applied extracellularly to isolated and cultured horizontal cells, the peptide also induced a slow depolarization (30 to 40 millivolts) accompanied by a decrease in membrane resistance. However, analogs of adenosine 3′,5′-monophosphate applied extracellularly or intracellularly, and forscolin applied extracellularly, had no effect on the membrane potential of cultured horizontal cells, indicating that the induced depolarization was not related to the accumulation of adenosine 3′,5′-monophosphate in these cells.
1,25-Dihydroxyvitamin D
3
Receptors in Human Leukocytes
Authors: Provvedini D. M. , Tsoukas C. D. , Deftos L. J. , Manolagas S. C.
Published: October 2006

A 1,25-dihydroxyvitamin D
3
receptor macromolecule was detected in peripheral mononuclear leukocytes from normal humans. This macromolecule was found to be present in monocytes but absent from normal resting peripheral B and T lymphocytes. However, it was present in established lines of malignant B, T, and non-B, non-T human lymphocytes, as well as in T and B lymphocytes obtained from normal humans and activated in vitro.
Transmission of Simian Acquired Immunodeficiency Syndrome (SAIDS) with Blood or Filtered Plasma
Authors: Gravell Maneth , London William T. , Houff Sidney A. , Madden David L. , Dalakas Marinos C. , Sever John L. , Osborn Kent G. , Maul Donald H. , Henrickson Roy V. , Marx Preston A. , Lerche Nicholas W. , Prahalada Srinivasa , Gardner Murray B.
Published: October 2006

Simian acquired immunodeficiency syndrome (SAIDS), a disease clinically and pathologically similar to acquired immunodeficiency syndrome in humans, was transmitted from diseased rhesus monkeys (
Macaca mulatta
) to normal monkeys by inoculation with heparinized whole blood or plasma that had been passed through filters of 0.45 micrometer pore size. This suggests that the causative agent is small and most probably a virus. No viruses, however, were isolated by standard cell culture techniques from the blood or filtered plasma which caused SAIDS. Both cellular and humoral immunity were markedly depressed in animals with advanced SAIDS.
Lymphokine Production by Cultured Human T Cells Transformed by Human T-Cell Leukemia-Lymphoma Virus-I
Authors: Salahuddin S. Z. , Markham P. D. , Lindner S. G. , Gootenberg J. , Popovic M. , Hemmi H. , Sarin P. S. , Gallo R. C.
Published: October 2006

Cell-free conditioned media from human T cells transformed by human T-cell leukemia-lymphoma virus (HTLV-I) were tested for the production of soluble biologically active factors, including several known lymphokines. The cell lines used were established from patients with T-cell leukemia-lymphoma and from human umbilical cord blood and bone marrow leukocytes transformed by HTLV-I in vitro. All of the cell lines liberated constitutively one or more of the 12 biological activities assayed. These included macrophage migration inhibitory factor (MIF), leukocyte migration inhibitory factor (LIF), leukocyte migration enhancing factor (MEF), macrophage activating factor (MAF), differentiation inducing factor (DIF), colony stimulating factor (CSF), eosinophil growth and maturation activity (eos. GMA), fibroblast activating factor (FAF), γ-interferon and, in rare instances, T-cell growth factor (TCGF). Some cell lines produced interleukin 3 (IL-3), platelet-derived growth factor (PDGF), or B-cell growth factors (BCGF). Such cells should prove useful for the production of lymphokines and as sources of specific messenger RNA's for their genetic cloning.
Cytomegalovirus Replicates in Differentiated But Not in Undifferentiated Human Embryonal Carcinoma Cells
Authors: Gönczöl Eva , Andrews Peter W. , Plotkin Stanley A.
Published: October 2006

To study the mode of action of human cytomegalovirus, an important teratogenic agent in human populations, the susceptibility of a pluripotent human embryonal carcinoma cell line to the virus was investigated. Viral antigens were not expressed nor was infectious virus produced by human embryonal carcinoma cells after infection, although the virus was able to penetrate these cells. In contrast, retinoic acid-induced differentiated derivatives of embryonal carcinoma cells were permissive for antigen expression and infectious virus production. Replication of human cytomegalovirus in human teratocarcinoma cells may therefore depend on cellular functions associated with differentiation.
Single-Copy Inverted Repeats Associated with Regional Genetic Duplications in γ Fibrinogen and Immunoglobulin Genes
Authors: Fornace Albert J. , Cummings David E. , Comeau Claudette M. , Kant Jeffery A. , Crabtree Gerald R.
Published: October 2006

We have found that a portion (150 base pairs) of the seventh exon of the human γ fibrinogen gene is duplicated in the preceding intron. This duplicated sequence, termed a "pseudoexon," is flanked on each side by a single-copy inverted repeat sequence consisting of 102 base pairs. Frequencies of point substitutions indicate that both the pseudoexon and the inverted repeat sequence arose approximately 10 to 20 million years ago. The generality of this type of duplication is suggested by the occurrence of a similar duplication in the mouse immunoglobulin μ-δ region. As in the fibrinogen pseudoexon, the portion of the immunoglobulin μ-δ region containing the duplication and the inverted repeat was reported to be single-copy in the mouse genome. Since both of the first two single-copy inverted repeats to be sequenced are associated with regional duplications, it is likely that many of the single-copy inverted repeat sequences, which make up 1 to 2 percent of the genome, are also associated with regional duplications.
Ca
2+
-Dependent Protein Kinase Injection in a Photoreceptor Mimics Biophysical Effects of Associative Learning
Authors: Acosta-Urquidi Juan , Alkon Daniel L. , Neary Joseph T.
Published: October 2006

Iontophoretic injection of phosphorylase kinase, a Ca
2+
-calmodulin-dependent protein kinase, increased input resistance, enhanced the long-lasting depolarization component of the light response, and reduced the early transient outward K
+
current,

I
A

, and the late K
+
currents, IB, in type B photoreceptors of
Hermissenda crassicornis
in a Ca
2+
-dependent manner. Since behavioral and biophysical studies have shown that similar membrane changes persist after associative conditioning, these results suggest that Ca
2+
-dependent protein phosphorylation could mediate the long-term modulation of specific K
+
channels as a step in the generation of a conditioned behavioral change.
An Endogenous Peptide Stimulates Secretory Activity in the Elasmobranch Rectal Gland
Authors: Shuttleworth Trevor J. , Thorndyke Michael C.
Published: October 2006

Extraction and partial purification of peptide material from the intestine of the elasmobranch
Scyliorhinus canicula
yielded a fraction that shows potent stimulatory activity in the rectal gland. The extracted material appears to contain an endogenous peptide (or peptides) that represents the natural hormone responsible for the control of rectal gland secretion in vivo.
Single Channel Studies on Inactivation of Calcium Currents
Authors: Lux H. D. , Brown A. M.
Published: October 2006

Inactivation of calcium channels has been attributed to a direct reaction of calcium ions entering the cell with the calcium channel. For a single channel this hypothesis predicts a correlation between the amount of calcium entering during an opening or a burst of openings and the subsequent closed times. No such correlation was found, and the possibility that, upon entry, calcium ions produce inactivation is excluded.
Mung Bean Nuclease Cleaves
Plasmodium
Genomic DNA at Sites Before and After Genes
Authors: McCutchan Thomas F. , Hansen Joanna L. , Dame John B. , Mullins Judith A.
Published: October 2006

Mung bean nuclease was found to cut the genomic DNA of the malaria parasite
Plasmodium
at positions before and after genes but not within gene-coding regions. This cleavage, which had nearly the preciseness of a restriction nuclease, required controlled conditions in the presence of formamide. Southern blot analysis showed that the coding areas for
Plasmodium
actin, circumsporozoite protein, histidine-rich protein, ribosomal RNA's, and tubulin are each cleaved from genomic DNA to yield a single major band on an agarose gel. DNA sequence data on several clones of mung bean nuclease cleavage products containing the gene for the circumsporozoite protein of
Plasmodium falciparum
confirmed that cleavage sites are before and after genes. Recognition and cleavage of DNA did not seem to be related to any primary sequence but may be related to structural features of the DNA duplex that demarcate genes. Mung bean nuclease-cleaved DNA could be inserted directly into a λ expression vector, yielding a representative but small gene bank of intact gene fragments.
Adoptive Immunotherapy of Established Pulmonary Metastases with LAK Cells and Recombinant Interleukin-2
Authors: Mulé James J. , Shu Suyu , Schwarz Susan L. , Rosenberg Steven A.
Published: October 2006

The activation of human peripheral blood leukocytes or murine splenocytes with interleukin-2 (IL-2) generated cells that were lytic in vitro for a variety of fresh tumor cells. The adoptive transfer of such lymphokine-activated killer (LAK) cells to mice with established pulmonary sarcoma metastases was highly effective in reducing the number (and size) of these tumor nodules when combined with repeated injections of recombinant IL-2. These findings provide a rationale for clinical trials of the infusion of human LAK cells generated with recombinant IL-2 as well as Phase I trials of the infusion of recombinant IL-2 systemically into humans.
Effects of Age on Dopamine and Serotonin Receptors Measured by Positron Tomography in the Living Human Brain
Authors: Wong Dean F. , Wagner Henry N. , Dannals Robert F. , Links Jonathan M. , Frost J. James , Ravert Hayden T. , Wilson Alan A. , Rosenbaum Arthur E. , Gjedde Albert , Douglass Kenneth H. , Petronis John D. , Folstein Marshal F. , Toung J. K. Thomas , Bums H. Donald , Kuhar Michael J.
Published: October 2006

D2 dopamine and S2 serotonin receptors were imaged and measured in healthy human subjects by positron emission tomography after intravenous injection of
11
C-labeled 3-
N
-methylspiperone. Levels of receptor in the caudate nucleus, putamen, and frontal cerebral cortex declined over the age span studied (19 to 73 years). The decline in D2 receptor in males was different from that in females.
The Human c-
ras
1
H
Oncogene: a Mutation in Normal and Neoplastic Tissue from the Same Patient
Authors: Muschel Ruth J. , Khoury George , Lebowitz Paul , Koller Richard , Dhar Ravi
Published: October 2006

The c-
ras
1
H
oncogene can be distinguished from its normal cellular counterpart by the loss of a restriction endonuclease site. This sequence alteration is the basis of a rapid screening method for the presence of this oncogene. DNA's from 34 individuals were screened by this method, and all were homozygous for the normal allele. In contrast, DNA from a patient's bladder tumor, as well as DNA from his normal bladder and leukocytes, were heterozygous at that restriction endonuclease site. Further restriction enzyme mapping pinpointed the change in the mutant allele as being one of two nucleotides, either of which would change the 12th amino acid (glycine) in the normal c-
ras
1
H
gene product. Point mutations in the codon for this amino acid have previously been described in a bladder tumor cell line and in the viral oncogene v-
ras
H
. These results indicate that the patient carried a c-
ras
1
H
oncogene in his germ line, raising the possibility that the c-
ras
1
H
oncogene confers a predisposition to neoplasia.
Splice Junctions: Association with Variation in Protein Structure
Authors: Craik Charles S. , Rutter William J. , Fletterick Robert
Published: October 2006

A comparison between eukaryotic gene sequences and protein sequences of homologous enzymes from bacterial and mammalian organisms shows that intron-exon junctions frequently coincide with variable surface loops of the protein structures. The altered surface structures can account for functional differences among the members of a family. Sliding of the intron-exon junctions may constitute one mechanism for generating length polymorphisms and divergent sequences found in protein families. Since intron-exon junctions map to protein surfaces, the alterations mediated by sliding of these junctions can be effected without disrupting the stability of the protein core.
In Vivo Determination of the Pyridine Nucleotide Reduction Charge by Carbon-13 Nuclear Magnetic Resonance Spectroscopy
Authors: Unkefer Clifford J. , Blazer Richard M. , London Robert E.
Published: October 2006

An intracellular coenzyme has been observed by carbon-13 nuclear magnetic resonance spectroscopy. The pyridine nucleotides inEscherichia coliwere specifically labeled with carbon-13 from the biosynthetic precursor, nicotinic acid. The intracellular redox status and metabolic transformations of the pyridine nucleotides were examined under a variety of conditions. A highly reduced nicotinamide adenine dinucleotide pool was observed under anaerobic conditions only in cells that were cultured aerobically on glycerol.
Infection-Specific Particle from the Unconventional Slow Virus Diseases
Authors: Merz P. A. , Rohwer R. G. , Kascsak R. , Wisniewski H. M. , Somerville R. A. , Gibbs C. J. , Gajdusek D. C.
Published: October 2006

Scrapie-associated fibrils, first observed in brains of scrapie-infected mice, were also observed in scrapie-infected hamsters and monkeys, in humans with Creutzfeldt-Jakob disease, and in kuru-infected monkeys. These fibrils were not found in a comprehensive series of control brains from humans and animals affected with central nervous system disorders resulting in histopathologies, ultrastructural features, or disease symptoms similar to those of scrapie, kuru, and Creutzfeldt-Jakob disease. These fibrils are also found in preclinical scrapie and in the spleens of scrapie-infected mice; they are a specific marker for the "unconventional" slow virus diseases, and may be the etiological agent.
Mating and Pregnancy Can Occur in Genetically Hypogonadal Mice with Preoptic Area Brain Grafts
Authors: Gibson Marie J. , Krieger Dorothy T. , Charlton Harry M. , Zimmerman Earl A. , Silverman Ann-Judith , Perlow Mark J.
Published: October 2006

Adult female hypogonadal mice, in whom hypogonadism is secondary to a genetic deficiency in hypothalamic gonadotropin-releasing hormone (GnRH), are infertile. Mating, pregnancy, and delivery of healthy litters were achieved after transplantation of normal fetal preoptic area tissue, a major site of GnRH-containing cell bodies, into the third ventricle of adult female hypogonadal mice. Immunocytochemistry revealed GnRH-containing neurons in the grafts and GnRH-containing processes extending to the lateral median eminence of the host brains.
Reversal of Knob Formation on
Plasmodium falciparum
-Infected Erythrocytes
Authors: Gritzmacher C. A. , Reese R. T.
Published: October 2006

The human malarial parasite
Plasmodium falciparum
can produce surface protrusions (knobs) on infected erythrocytes; however, long-term culturing of the parasite results in the appearance of knobless cells. In this study it was found that a knob-producing clone lost the ability to produce knobs in vitro. Furthermore, a clone not producing knobs derived from the knob-producing clone regained the capacity to produce knobby cells in vitro. Certain parasite proteins were associated with the knobby phenotype but not with the knobless type. These results indicate that the parasites change in vitro in a spontaneous and reversible manner independent of immunological selection.
Reverse Banding on Chromosomes Produced by a Guanosine-Cytosine Specific DNA Binding Antibiotic: Olivomycin
Authors: van de Sande J. H. , Lin C. C. , Jorgenson K. F.
Published: October 2006

Characteristic reverse fluorescent banding patterns (R bands) on human, bovine, and mouse metaphase chromosomes are produced by treating chromosome preparations directly with olivomycin. With the DNA in solution, the repeating polymer poly[d(G-C)] ⋅ poly[d(G-C)] (where G is guanine and C is cytosine) enhanced the fluorescence of olivomycin, while the antibiotic fluorescence was not affected by the alternating polynucleotide poly[d(A-T)] ⋅ poly[d(A-T)] (where A is adenine and T is thymine). Calf thymus DNA, with an intermediate G-C content of about 40 percent, showed a smaller fluorescence enhancement in the presence of olivomycin as was observed for the synthetic polynucleotide poly[d(G-C)] ⋅ poly [d(G-C)]. The closely related antibiotic chromomycin A
3
showed the same results as were obtained with olivomycin either in the solution interaction with specific DNA's or with the metaphase chromosome preparations. The production of R bands by these G-C-specific DNA binding antibiotics lends credence to the suggestion that the arrangement of the nucleotide sequences along the chromosome is a primary determinant for the appearance of fluorescent bands.
Cloned Fragment A of Diphtheria Toxin Is Expressed and Secreted into the Periplasmic Space of
Escherichia coli
K12
Authors: Leong Diane , Coleman Kenneth D. , Murphy John R.
Published: October 2006

An 831-base pair segment of the corynebacteriophage β
tox-45
genome encoding fragment A of diphtheria toxin was cloned into plasmid pUC8 in
Escherichia coli
K12. Strains containing recombinant plasmids expressed the adenosine diphosphate ribosyl transferase activity characteristic of fragment A; this activity could be inhibited by polyvalent antiserum to fragment A as well as by the appropriate monoclonal antibodies to diphtheria toxin. The transferase activity was secreted into the periplasmic space of
E. coli
. These findings have implications for the future construction of genetically engineered chimeric toxins.
Potent Interaction Between Glucocorticoids and Growth Hormone-Releasing Factor in Vivo
Authors: Wehrenberg William B. , Baird Andrew , Ling Nicholas
Published: October 2006

Administration of dexamethasone significantly enhanced the pituitary growth hormone response to growth hormone-releasing factor in intact as well as adrenalectomized rats. Thus the inhibitory effects of glucocorticosteroids on somatic growth which involve an interaction of these steroids and growth hormone at a peripheral level may also involve a modification of pathways within the central nervous system that regulate normal growth hormone secretion.
Nucleotide Sequence of a Light Chain Gene of the Mouse I-A Subregion: Aβ
d
Authors: Malissen Marie , Hunkapiller Tim , Hood Leroy
Published: October 2006

Ia (I region-associated) antigens are cell-surface glycoproteins involved in the regulation of immune responsiveness. They are composed of one heavy (α) and one light (β) polypeptide chain. We have sequenced the gene encoding the Aβ
d
chain of the BALB/c mouse. The presence of six exons is predicted by comparison with the complementary DNA sequences of human β chains and with partial protein sequence data for the Aβ
d
polypeptide. Sequence comparisons have been made to other proteins involved in immune responses and the consequent implications for the evolutionary relationships of these genes are discussed.
Inhibition of Gastric Acid Secretion in Rats by Intracerebral Injection of Corticotropin-Releasing Factor
Authors: Taché Yvette , Goto Yoshiaki , Gunion Mark W. , Vale Wylie , River Jean , Brown Marvin
Published: October 2006

Intracisternal injection of ovine corticotropin-releasing factor (CRF) into the pylorus-ligated rat or the rat with gastric fistula resulted in a dose-dependent inhibition of gastric secretion stimulated with pentagastrin or thyrotropin-releasing hormone. When injected into the lateral hypothalamus--but not when injected into the cerebral cortex—CRF suppressed pentagastrin-stimulated acid secretion. The inhibitory effect of CRF was blocked by vagotomy and adrenalectomy but not by hypophysectomy or naloxone treatment. These results indicate that CRF acts within the brain to inhibit gastric acid secretion through vagal and adrenal mechanisms and not through hypophysiotropic effects.