bluuebunny/crossref_metadata_2025 huggingface dataset:
The Forebrain Is Not Essential for Sympathoadrenal Hyperglycemic Response to Glucoprivation
Authors: DiRocco Richard J. , Grill Harvey J.
Published: October 2006

The reduction of glycolysis by hypoglycemia or the glucose analog 2-deoxy-D-glucose (2DG) stimulates compensatory sympathetic alterations of metabolism. Considerable attention has been focused on the hypothalamus as the probable locus of requisite metabolic signal detection. We report, however, that unanesthetized chronically decerebrate rats are capable of exhibiting sympathoadrenal hyperglycemia in response to the metabolic challenge presented by 2DG. This finding demonstrates that the forebrain is not necessary for glucoprivic stimulation of this reflex. Since cervical cord transection has been shown to eliminate hyperglycemia induced by 2DG, we conclude that the caudal brainstem contains an essential part of the neural mechanism which both detects metabolic need and ameliorates that need through the release of stored fuels.
Tissue Perfusion Rate Determined from the Decay of Oxygen-15 Activity After Photon Activation in Situ
Authors: Hughes Walter L. , Nussbaum Gilbert H. , Connolly Raymond , Emami Bahman , Reilly Paul
Published: October 2006

Rates of cerebral perfusion were obtained from measurement of the disappearance (wash-out) of oxygen-15 after in situ tissue activation with 45-million-volt x-rays. In an anesthetized cat, typical values were 90 milliliters per minute per 100 grams of tissue, with 55 percent wash-out. In a specific radiotherapy patient, the value was 65 milliliters per minute per 100 grams of tissue, with 63 percent wash-out of oxygen-15 through incorporation into tissue water.
Type C RNA Tumor Virus Isolated from Cultured Human Acute Myelogenous Leukemia Cells
Authors: Gallagher Robert E. , Gallo Robert C.
Published: October 2006

Previously, type C RNA tumor virus-related components have been described in blood leukocytes from patients with acute myelogenous leukemia. These components, for example, reverse transcriptase, have been shown to be most closely related to those from two oncogenic subhuman primate type C viruses (woolly monkey sarcoma virus and gibbon ape leukemia virus). Now, we report the continuous production of budding type C viruses with the same characteristic reverse transcriptase by three separate culturings of leukocytes from a single bleeding from a patient with acute myelogenous leukemia. These isolations were made possible by the discovery of a source of conditioned media which sustains exponential growth of human myelogenous leukemia cells in liquid suspension culture.
Psychotropic Drugs as Behavioral Teratogens
Authors: Vorhees Charles V. , Brunner Robert L. , Butcher Richard E.
Published: October 2006

Three psychotropic drugs were administered to pregnant rats and were then evaluated for their behavioral and reproductive effects in the offspring. Control rats received either saline or vitamin A. Prochlorperazine had the most disruptive effects on reproduction and growth, but had the least effect on behavior. Propoxyphene had no apparent effects on reproduction or growth, but produced a variety of behavioral changes. Fenfluramine was intermediate in its effects on reproduction and growth and had behavioral effects that were revealed in tests of preweaning development. The data suggest that systematic tests of behavior add important information to evaluations of reproductive toxicity that cannot, at present, be obtained by other means.
Acridine Araphanes: A New Class of Probe Molecules for Biological Systems
Authors: Himel Chester M. , Taylor Jeffrey L. , Pape Courtney , Millar David B. , Christopher John , Kurlansik Leo
Published: October 2006

The bis-acridine ring system forms the basis for new biophysical probes of novel stereochemistry. Spectral data indicate that certain alkylene bridged bis-9-aminoacridines have a parallel plane conformation of predictable interplane distance. The parallel plane conformation is independent of solvent and thus is different from nucleic acid systems. This stable conformation allows these compounds to be used as sensitive "rulers" for describing binding site geometry in cholinergic enzymes and in the delineation of the mechanism of allosteric control in acetylcholinesterase.
Angiogenesis in the Mouse Cornea
Authors: Muthukkaruppan Vr. , Auerbach R.
Published: October 2006

We have developed a method that permits analysis of neovascular responses in the mouse cornea. Using this method we have demonstrated that both allogeneic lymphocytes and a variety of tumors can induce angiogenesis, but that only the latter appear capable of eliciting secondary capillary sprouting.
Perinatal Exposure to Cannabinoids Alters Male Reproductive Function in Mice
Authors: Dalterio Susan , Bartke Andrzej
Published: October 2006

Oral administration of Δ
9
-tetrahydrocannabinol or cannabinol to female mice late in pregnancy and during early lactation alters body weight regulation and pituitary-gonadal function and suppresses adult copulatory activity in their male offspring. These findings suggest that both psychoactive and nonpsychoactive constituents of marihuana can affect the development of male reproductive functions in mice.
Angular Invariants in Developing Human Mandibles
Authors: Webber Richard L. , Blum Harry
Published: October 2006

Recent studies of lateral cephalograms based on symmetric-axis analyses of the mandibular border yield angles that appear to be uninfluenced by gross changes in mandibular shape over age and between individuals.
Cortical Plasticity in Monocularly Deprived Immobilized Kittens Depends on Eye Movement
Authors: Freeman R. D. , Bonds A. B.
Published: October 2006

A marked reduction of binocular cells in striate cortex is found if 4-week-old kittens are visually stimulated monocularly while anesthetized and held in a stereotaxic apparatus. If the kittens are paralyzed and artificially respirated, changes are not found unless an eye is moved mechanically. It appears that eye movement and visual stimulation are necessary conditions for deactivation of binocular connections, but neither is sufficient to induce such changes alone.
Choline Excites Cortical Neurons
Authors: Krnjević K. , Reinhardt W.
Published: October 2006

In cats under halothane or methoxyflurane, iontophoretic applications of choline are only eight times weaker than applications of acetylcholine in evoking firing of neurons in the sensorimotor region of the cerebral cortex. The action of choline is suppressed by atropine but not by two agents that block choline uptake (hemicholinium-3 and triethylcholine), and is not potentiated by an anticholinesterase (physostigmine). Choline therefore appears to excite cortical neurons by a direct action, which may be a significant component of its beneficial therapeutic effects.
An Ultramicroscopic Study of the Two Stages of Blood Coagulation
Authors: Rich Arnold Rice
Published: October 2006

There is no reaction-basis for the division of the process of blood-coagulation into the two stages (transparent and opaque) which appear so strikingly in slowly-clotting mammalian blood. These stages are superficial phenomena which merely reflect the extent of fibrin-formation. Coagulation is a gradual continuous process of fibrin-formation; and in the clotting of normal plasma, fibrin needles can be demonstrated in the earliest appreciable coagulum, however delicate, transparent or gel-like.
Biochemical Evidence for Keratinization by Mouse Epidermal Cells in Culture
Authors: Steinert Peter , Yuspa Stuart H.
Published: October 2006

More than 70 percent of the urea-extractable proteins from mouse stratum corneum or from differentiated cells of mouse epidermis grown in culture are two proteins of molecular weight 68,000 (keratin 1) and 60,000 (keratin 2), which are present in equimolar amounts on polyacrylamide gels. These proteins are the subunits of the keratin filaments, because when isolated from stratum corneum or cells grown in culture they form native-type epidermal keratin filaments in vitro. These observations provide biochemical evidence that epidermal cells grown in culture synthesize the major differentiation products of the epidermis.
Selective Inhibition of Tubulin Synthesis by Amiprophos Methyl During Flagellar Regeneration in
Chlamydomonas reinhardi
Authors: Collis Philip S. , Weeks Donald P.
Published: October 2006

Amiprophos methyl (APM) is a strong, readily reversible and highly selective inhibitor of tubulin synthesis in
Chlamydomonas reinhardi
. The extensive induction of tubulin synthesis that accompanies flagellar regeneration in this organism is prevented by 3 to 10 μ
M
APM. When applied after induction has begun, APM causes a rapid cessation of tubulin synthesis. Translation studies in vitro indicate that the lack of tubulin production in APM-treated cells is not due to a direct inhibition of tubulin messenger RNA translation but rather to a selective depletion of tubulin messenger RNA.
Thiourea Reverses Cross-Links and Restores Biological Activity in DNA Treated with Dichlorodiaminoplatinum(II)
Authors: Filipski Jan , Kohn Kurt W. , Prather Richard , Bonner William M.
Published: October 2006

Cis
and
trans
dichlorodiaminoplatinum (II) compounds bind to DNA and form DNA cross-links, which are usually considered to be irreversible. Thiourea can reverse these cross-links without any apparent breakdown of the DNA. In addition,
cis
- and
trans
-Pt(II) treatment of λ DNA decreases its transfectivity. After suitable incubation with thiourea, full transfectivity of Pt(II)-treated λ DNA can be restored.
Prenatal Stress Reduces Fertility and Fecundity in Female Offspring
Authors: Herrenkohl Lorraine Roth
Published: October 2006

Female rats subjected to prenatal stress later experienced fewer conceptions, more spontaneous abortions and vaginal hemorrhaging, longer pregnancies, and fewer viable young than nonstressed rats. The offspring of the prenatally stressed rats were lighter in weight and less likely to survive the neonatal period. Prenatal stress may influence the balance of adrenal and gonadal hormones during a critical stage of fetal hypothalamic differentiation, thereby producing a variety of reproductive dysfunctions in adulthood.
Benzodiazepine Receptor Synthesis and Degradation by Neurons in Culture
Authors: Borden Laurence A. , Czajkowski Cynthia , Chan Christopher Y. , Farb David H.
Published: October 2006

The benzodiazepine-γ-aminobutyric acid receptor complex was used to study functional receptor synthesis and degradation in primary cultures of neurons. Fifty percent of the receptors turned over with an unusually rapid half-life (4 hours); this was followed by a second, slower phase (32 hours). These results provide the basis for elucidating the mechanism by which neurons derived from the central nervous system control neurotransmitter receptor number, an important problem in cellular neurobiology. The findings may be of significance in the study of neurological and psychiatric disorders.
Persistence of the Entire Epstein-Barr Virus Genome Integrated into Human Lymphocyte DNA
Authors: Matsuo Takumi , Heller Mark , Petti Lisa , O'Shiro Eric , Kieff Elliot
Published: October 2006

The entire Epstein-Barr virus genome is integrated into Burkitt tumor cell DNA at the terminal direct repeat sequence of the virus. There is no homology between the GC-rich (G, guanine; C, cytosine) terminal repeat and the AT-rich (A, adenine; T, thymine) cell sequences with which it has recombined. More than 15 kilobases of cell DNA have been deleted and 236 base pairs are duplicated at one virus-cell junction site.
Chemical DNA Synthesis and Recombinant DNA Studies
Authors: Itakura Keiichi , Riggs Arthur D.
Published: October 2006

Chemically synthesized DNA has been used in many recombinant DNA studies. These uses have included the total synthesis and cloning of functional genes, the cloning and expression of natural genes, and editing and changing genes by directed mutation.
Efferent Fibers to
Limulus
Eyes Synthesize and Release Octopamine
Authors: Batelle B. A. , Evans J. A. , Chamberlain S. C.
Published: October 2006

Octopamine synthesized in vitro from tyramine by
Limulus
lateral and ventral eyes was located by light microscopic and electron microscopic autoradiography in efferent fibers which innervate ventral photoreceptors and lateral eye ommatidia. Newly synthesized octopamine was released from efferent fibers in response to depolarization in high concentrations of potassium. We propose that octopamine is a neurotransmitter of efferent fibers that may modulate basic retinal processes such as photoreceptor sensitivity, photomechanical movements, and photoreceptive membrane turnover.
Time: A New Parameter for Kinetic Measurements in Flow Cytometry
Authors: Martin John C. , Swartzendruber Douglas E.
Published: October 2006

The measure of time was used as an additional parameter on an existing flow cytometer to study the kinetics of enzyme activities and cell-stain interactions. By correlating all fluorescent signals from single cells with time, the dynamics of a reaction can be followed for several minutes. This advanced application of flow cytometry is easily implemented and can be incorporated into any flow cytometer that has two-parameter analysis capability.
Structure and in Vitro Transcription of Human Globin Genes
Authors: Proudfoot Nicholas J. , Shander Monica H. M. , Manley Jim L. , Gefter Malcolm L. , Maniatis Tom
Published: October 2006

The alpha-like and beta-like subunits of human hemoglobin are encoded by a small family of genes that are differentially expressed during development. Through the use of molecular cloning procedures, each member of this gene family has been isolated and extensively characterized. Although the alpha-like and beta-like globin genes are located on different chromosomes, both sets of genes are arranged in closely linked clusters. In both clusters, each of the genes is transcribed from the same DNA strand, and the genes are arranged in the order of their expressions during development. Structural comparisons of immediately adjacent genes within each cluster have provided evidence for the occurrence of gene duplication and correction during evolution and have led to the discovery of pseudogenes, genes that have acquired numerous mutations that prevent their normal expression. Recently, in vivo and in vitro systems for studying the expression of cloned eukaryotic genes have been developed as a means of identifying DNA sequences that are necessary for normal gene function. This article describes the application of an in vitro transcription procedure to the study of human globin gene expression.
Secondary Structure of 16
S
Ribosomal RNA
Authors: Noller Harry F. , Woese Carl R.
Published: October 2006

A secondary structure model for 16
S
ribosomal RNA which is based on available chemical, enzymatic, and comparative sequence data shows good agreement between constraints dictated by the model and a wide variety of experimental observations. The four major structural domains created by the base-pairing scheme correspond closely to RNA fragments isolated after nuclease digestion in the presence of bound ribosomal proteins. Functionally important sites appear to be located in unpaired regions and are phylogenetically highly conserved.
Substance P Activity in the Bullfrog Retina: Localization and Identification in Several Vertebrate Species
Authors: Eskay R. L. , Furness J. F. , Long R. T.
Published: October 2006

Immunoreactive substance P is present in the bullfrog retina, possibly in two types of stratified amacrine cells, with their somas in the inner nuclear layer and their neuronal processes entering the inner plexiform layer and ramifying in sublayers 3 or 4 (or both). Occasionally, polygonal somas positive for substance P were found in the ganglion cell layer. Approximately 75 percent of the cell bodies positive for substance P and 65 percent of the radioimmunoassayable substance P were found in the superior half of the frog retina. On the basis of high-performance liquid chromatography, the immunoreactive substance P in the neural retina of the rat, monkey, or chick is similar to synthetic substance P, whereas this is not true of the immunoreactive substance P in the bullfrog or carp retina.
Biosynthesis of Biopterin: Adrenergic Cyclic Adenosine Monophosphate-Dependent Inhibition in the Pineal Gland
Authors: Kapatos Gregory , Kaufman Seymour , Weller Joan L. , Klein David C.
Published: October 2006

Pineal glands in organ culture synthesize and release biopterin and are able to maintain concentrations of biopterin occurring in vivo for up to 54 hours in vitro. The intracellular biopterin content is reduced 50 percent by treatment with
l
-norepinephrine or cyclic adenosine monophosphate derivatives, but not by
d
-norepinephrine. This is an indication that biopterin levels are regulated by an adrenergic cyclic adenosine monophosphate-dependent mechanism. The decline in tissue biopterin content, produced mainly by inhibition of biosynthesis, is maximal at 6 hours and is not associated with either an increase in biopterin release or a shift in the reduction state of the biopterin.
Automated Synthesis of Gene Fragments
Authors: Alvarado-Urbina Gabriel , Sathe Ganesh M. , Liu Wing-Cheong , Gillen Michael F. , Duck Peter D. , Bender Robert , Ogilvie Kelvin K.
Published: October 2006

The DNA/RNA Synthesizer provides a complete and automated procedure for the synthesis of DNA sequences. Each base unit is added in a 30-minute cycle, permitting a tetradecamer to be constructed in 6½ hours. The complete procedure is described, including a practical procedure for isolation and purification of the desired DNA sequence.
Further Heterogeneity of Human α Interferon mRNA Species
Authors: Sehgal Pravinkumar B. , Sagar Anurag D. , Braude Irwin A.
Published: October 2006

Translationally active (in
Xenopus
oocytes) human α interferon (IFN) messenger RNA's (mRNA's) derived from Sendai virus—induced leukocyte cultures display a bimodal distribution of RNA lengths on electrophoresis through agarose-CH
3
HgOH gels. The major population (α
s
) consists of mRNA of length 0.7 to 1.4 kilobases, while the minor population (α
L
) consists of RNA of length 1.6 to 3.5 kilobases. Induction of human leukocytes in the presence of 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DRB; 100 micromolar) appears to inhibit the accumulation of IFN-α
s
and to enhance that of IFN-α
L
mRNA's (average length about 1.8 kilobases in preparations from DRB-treated cells). Interferons derived from the α
s
mRNA's represent the group of previously recognized α interferons while the α
L
interferons are distinguishable from this group by their lower heterospecific activity on bovine cells compared to human cells, their apparent slower mobility in sodium dodecyl sulfate—polyacrylamide gels, and their apparent heteroclitic response toward an antiserum to IFN-α.
Efferents to the Retina Have Multiple Sources in Teleost Fish
Authors: Ebbesson S. O. E. , Meyer D. L.
Published: October 2006

Multiple efferent systems project to the retina in three species of teleost fish investigated with the horseradish peroxidase technique. These animals are the first vertebrates shown to have more than one central nervous system structure projecting to the retina. The connections discovered may reflect a primitive organization of retina-brain interconnections.
Multiplication of Tobacco Mosaic Virus in Tobacco Leaf Disks Is Inhibited by (2′-5′) Oligoadenylate
Authors: Devash Yair , Biggs Sara , Sela Ilan
Published: October 2006

The oligonucleotide (2′-5′) oligoadenylate that is induced in interferon-treated animal cells protects plant tissue from infection by the tobacco mosaic virus. This inhibition of virus multiplication was obtained at concentrations comparable to those affecting protein synthesis and antiviral activities in animal cells. After treatment with (2′-5′) oligoadenylate, the multiplicability of tobacco mosaic virus was reduced by 80 to 90 percent, as measured by enzyme-linked immunosorbent assay. These results, along with the observation that human interferon protects tobacco tissue from infection by tobacco mosaic virus, indicate that plants and animals may have a common pathway for virus resistance.
Small Nuclear RNA U2 Is Base-Paired to Heterogeneous Nuclear RNA
Authors: Calvet James P. , Meyer Leslie M. , Pederson Thoru
Published: October 2006

Eukaryotic cells contain a set of low molecular weight nuclear RNA's. One of the more abundant of these is termed U2 RNA. The possibility that U2 RNA is hydrogen-bonded to complementary sequences in other nuclear RNA's was investigated. Cultured human (HeLa) cells were treated with a psoralen derivative that cross-links RNA chains that are base-paired with one another. High molecular weight heterogeneous nuclear RNA was isolated under denaturing conditions, and the psoralen cross-links were reversed. Electrophoresis of the released RNA and hybridization with a human cloned U2 DNA probe revealed that U2 is hydrogen-bonded to complementary sequences in heterogeneous nuclear RNA in vivo. In contrast, U2 RNA is not base-paired with nucleolar RNA, which contains the precursors of ribosomal RNA. The results suggest that U2 RNA participates in messenger RNA processing in the nucleus.
Human Leukocyte Functions and the U.S. Safety Standard for Exposure to Radio-Frequency Radiation
Authors: Roberts Norbert J. , Lu Shin-Tsu , Michaelson Sol M.
Published: October 2006

Human mononuclear leukocytes were exposed to microwaves at energies relevant to current public safety recommendations. No detectable effects on viability or function of the leukocytes resulted from exposure to microwaves at specific absorption rates up to 4 milliwatts per milliliter. The results were highly reproducible and provided no evidence that current safety standard recommendations are inappropriate insofar as leukocyte function is concerned.
Interaction of Human Hemoglobin and Its Variants with Agar
Authors: Winter William P. , Yodh Jaya
Published: October 2006

In citrate agar electrophoresis hemoglobin appears to bind reversibly to the sulfated polysaccharide agaropectin, a natural component of Difco Bacto-Agar. This complex migrates anodally, since the hemoglobin is only weakly positively charged at
p
H 6.2 whereas the carbohydrate carries a net negative charge. Electroendosmosis, on the other hand, proceeds in the cathodal direction. These opposing fluxes separate the hemoglobins in the order of their affinity for agaropectin. An agaropectin binding site was identified on hemoglobin by computer-assisted modeling, and the relation of the site to hemoglobin variants that exhibit abnormal citrate agar mobility was established. The citrate anion is postulated to function as a "counter ion." Preliminary evidence indicates that agaropectin has antigelling properties with respect to hemoglobin S.
Cell-to-Cell Transfer of Interferon-Induced Antiproliferative Activity
Authors: Lloyd Richard E. , Blalock J. Edwin , Stanton G. John
Published: October 2006

Interferon-treated cells rapidly and efficiently transferred the antiproliferative activity of interferon to untreated cells. This phenomenon was not due to the carry-over of interferon by the interferon-treated cells. Thus, to evoke an antiproliferative state, interferon did not directly contact each cell in a population. The results suggest a novel mechanism by which interferon may indirectly regulate cell growth, and suggests that cells other than those of the immune system may play a role in controlling tumor growth in tissue where cell-to-cell contact occurs.
Precocious Cardiac Orienting in a Human Anencephalic Infant
Authors: Graham Frances K. , Leavitt Lewis A. , Strock Barbara D. , Brown James W.
Published: October 2006

An anencephalic infant, 3 to 6 weeks old, responded to acoustic stimulation with cardiac decelerations typical of the response pattern seen in normal, older infants. Such precocity implies unexpected competence of lower brain structures and suggests that, in the normal infant, feedback from immature higher centers may sometimes interfere with rather than modulate the functioning of lower centers.
Multiple Mutations Produce δβ
0
Thalassemia in Sardinia
Authors: Pirastu Mario , Kan Yuet Wai , Galanello Renzo , Cao Antonio
Published: October 2006

In Sardinia the common form of β thalassemia is a β
0
thalassemia due to a nonsense mutation at codon 39. δβ
0
Thalassemia is rare in Sardinia and is associated with increased production of hemoglobin F of the
A
γ type. In this study we used a synthetic oligomer assay and detected the β
39
nonsense mutation on the δβ
0
thalassemia chromosome. Hence at least two different mutations have occurred on this chromosome; one that increases
A
γ globin synthesis and another that silences the β globin gene.
Location and Chemical Synthesis of a Pre-S Gene Coded Immunodominant Epitope of Hepatitis B Virus
Authors: Neurath A. Robert , Kent Stephen B. H. , Strick Nathan
Published: October 2006

Immunodominant, disulfide-bond independent epitopes recognized by human antibodies to hepatitis B virus (HBV) are located within the 55-residue amino terminal portion (coded for by the pre-S region of HBV DNA) of minor HBV envelope components larger than the major protein constituents encoded by the S gene. A peptide having the sequence of the first 26 amino acids from the amino terminal methionine was synthesized and elicited antibodies (at dilutions of ≥ 1 to 10
5
) to the HBV envelope. These antibodies can be utilized for diagnostic tests. The immunogenicity of the peptide was substantially increased by covalent attachment to liposomes. The disulfide bond-independent determinants on sequences coded for by the pre-S gene may be more easily mimicked by peptide analogs than "conformational" determinants on the S-gene product.
Molecular Model for Messenger RNA Splicing
Authors: MacCumber Mathew , Ornstein Rick L.
Published: October 2006

A molecular model is presented for a messenger RNA (mRNA) "splice region." The model requires cation coordination to reduce backbone-backbone electrostatic repulsion and it allows for every base residue on the pre-mRNA to be stacked in A-form helical geometry with a recognition element on the intron or exon (or both) sides of the splice junction. The two nucleotides involved in the initial steps of the cleavage-ligation mechanism must adopt a non-A-form geometry, which ideally positions reactive groups on the pre-mRNA for the necessary catalytic chemistry. The model is also consistent with available biochemical data on splicing reactions.
Illumination Induces Dye Incorporation in Photoreceptor Cells
Authors: Wilcox Michael , Franceschini Nicolas
Published: October 2006

Illumination of fly photoreceptors in the presence of the fluorescent dye Lucifer yellow initiates incorporation of the dye, which stains each cell down to its synaptic terminal. Unilluminated cells do not become stained. Experiments on animals in vivo show that selected cells can be stained without loss of viability. "Induced endocytosis" provides a plausible mechanism underlying this phenomenon.
δ-Aminolevulinic Acid-Synthesizing Enzymes Need an RNA Moiety for Activity
Authors: Huang Dinq-Ding , Wang Wei-Yeh , Gough Simon P. , Kannangara C. Gamini
Published: October 2006

When
Chlamydomonas
enzymes that convert glutamate to δ-aminolevulinic acid are separated into three fractions, one of the fractions contains RNA, and the RNA moiety is needed for the enzyme activity.
Facilitated Sexual Behavior Reversed and Serotonin Restored by Raphe Nuclei Transplanted into Denervated Hypothalamus
Authors: Luine Victoria N. , Renner Kenneth J. , Frankfurt Maya , Azmitia Efrain C.
Published: October 2006

Fetal raphe cells transplanted into the hypothalamus reversed facilitation of feminine sexual behavior in rats with brain lesions induced by 5,7-dihydroxytryptamine. Immunocytochemical and chemical analyses of serotonin indicate that reinnervation of the ventromedial nucleus of the hypothalamus by the transplants is associated with behavioral recovery. The findings suggest that transplanted fetal tissue can exert functional regulation over an innate, complex, hormone-dependent behavior in adult rats.
Ontogeny of Gastric Acid Secretion in the Rat: Evidence for Multiple Response Systems
Authors: Ackerman Sigurd H.
Published: October 2006

Gastric acid secretion has been thought to depend on histamine stimulation of the parietal cell. However, in the 2-week-old rat neither exogenous histamine nor the H-2 receptor agonist impromidine stimulates acid secretion, whereas pentagastrin and the cholinergic agent bethanechol are potent stimuli. At this age, the effect of pentagastrin on acid secretion is not blocked by the H-2 receptor antagonist cimetidine, nor is it potentiated by impromidine. These data suggest that, in the rat pup, the acid secretory response to pentagastrin and cholinergic agents occurs before the histamine-mediated system is functional and operates independently of the actions of histamine.
Structure of Collagen in Cartilage of Intervertebral Disk
Authors: Berthet C, , Hulmes D, J. S. , Miller A, , Timmins P. A.
Published: October 2006

Small-angle x-ray and neutron diffraction patterns have been obtained from the annulus fibrosus of porcine intervertebral disk. These show that the collagen in this tissue is modified compared with that in tendon.
Sulfhydryl Groups and the Monodeiodination of Thyroxine to Triiodothyronine
Authors: Chopra Inder J.
Published: October 2006

Sulfhydryl reagents exert a profound influence on the monodeiodination of thyroxine to triiodothyronine by rat and sheep tissues in vitro. A marked dithiothreitol-induced increase in the monodeiodination by fetal sheep liver homogenates suggests that the characteristically low conversion in fetal tissues is related more to the status of sulfhydryl groups than to a deficiency of the monodeiodinating enzyme.
Neurotransmitter Release from a Vertebrate Neuromuscular Synapse Affected by a Food Dye
Authors: Augustine George J. , Levitan Herbert
Published: October 2006

The food dye erythrosine (Erythrosin B; FD & C No. 3) was applied to isolated neuromuscular synapses in the frog, and its effects on the spontaneous quantal release of acetylcholine were examined with electrophysiological techniques. At concentrations of 10 μ
M
or greater this anionic dye produced an irreversible, dose-dependent increase in neurotransmitter release. This increase did not depend on the presence of calcium ions in the bathing medium. These results suggest that erythrosine might prove a useful pharmacological tool for studying the process of transmitter release, but that its use as a food additive should be reexamined.
Insertion of a New Gene of Viral Origin into Bone Marrow Cells of Mice
Authors: Mercola Karen E. , Stang Howard D. , Browne Jeffrey , Salser Winston , Cline Martin J.
Published: October 2006

DNA containing the herpes simplex virus thymidine kinase (HSVtk) gene was used to transform wild-type tk
+
mouse L cells to a tk
++
status in vitro using methotrexate as a selective agent. HSVtk DNA was also used to transform mouse bone marrow cells in vitro. Transformed marrow cells injected into irradiated and methotrexate-treated recipient mice gave rise to proliferating cells which in some cases dominated the marrow population and which contained HSVtk gene sequences.
Simian Virus 40 Crystals
Authors: Lattman Eaton E.
Published: October 2006

Small (10 to 150 micrometers) cubic crystals of simian virus 40 have been grown by ammonium sulfate precipitation. Electron micrographs of thin sections from these crystals reveal ordered arrays of virus particles.
Mitochondrial Water in Myocardial Ischemia: Investigation with Nuclear Magnetic Resonance
Authors: Michael Lloyd H. , Seitz Patricia , McMillin-Wood Jeanie , Chang Donald , Hazlewood Carlton , Entman Mark L.
Published: October 2006

Nuclear magnetic resonance studies of mitochondria isolated from ischemic hearts after coronary vessel occlusion indicated a decrease in water proton relaxation times. This change coincided with a decrease in the hydration of the samples. It is suggested that in ischemia, changes in macromolecular hydration may be one of the first mechanisms to alter function in the mitochondria, which are vital to the energy-transducing process in heart muscle.
Thyroid Hormone Receptor-Containing Fragment Released from Chromatin by Deoxyribonuclease I and Micrococcal Nuclease
Authors: Jump Donald B. , Oppenheimer Jack H.
Published: October 2006

Limited deoxyribonuclease I and micrococcal nuclease digestion of hepatic nuclei from euthyroid rats injected with
125
I-labeled triiodothyronine ([
125
I]T
3
) releases a discrete [
125
I]T
3
-labeled chromatin fragment (5.8
S
) which is larger than the T
3
receptor (3.5
S
). These results suggest the T
3
receptor is associated with a restricted fraction of hepatic chromatin that has a nuclease sensitivity characteristic of transcriptionally active chromatin.
Effect of Adenosine 3′,5′-Monophosphate on Neuronal Pacemaker Activity: a Voltage Clamp Analysis
Authors: Treistman Steven N.
Published: October 2006

Bursting pacemaker activity in nerve cells can be modified for long periods by synaptic input of short duration. There is evidence that cyclic nucleotides may play a role in these modifications. The predominant effect of elevated levels of adenosine 3′,5′-monophosphate in
Aplysia
neurons was an increased slope conductance to hyperpolarizing pulses, evident in voltage clamp records. A similar increase in slope conductance was seen as one component of maximum strength synaptic stimulation, which is consistent with the idea that cyclic nucleotides are important in the expression of synaptic alteration of bursting pacemaker activity.
Hypothyroidism Elicits Electrophysiological Noradrenergic Subsensitivity in Rat Cerebellum
Authors: Marwaha Jwaharlal , Prasad Kedar N.
Published: October 2006

Discharge rates of Purkinje neurons were compared in control and hypothyroid adult rats. Purkinje neurons in hypothyroid rats fired significantly faster and were less sensitive to iontophoretically applied norepinephrine than those in control rats. The subsensitivity of the Purkinje neurons appeared to be primarily due to an alteration in the β-receptor—adenylate cyclase complex, because the sensitivity of these cells to locally applied N
6
-monobutyryl adenosine 3′,5′-monophosphate (N
6
cyclic AMP) did not change significantly. The sensitivity of the Purkinje neurons to norepinephrine could be restored in hypothyroid rats by administration of triiodothyronine.
Adenosine 3′,5′-Monophosphate Modulates Thyrotropin Receptor Clustering and Thyrotropin Activity in Culture
Authors: Avivi A. , Tramontano D. , Ambesi-Impiombato F. S. , Schlessinger J.
Published: October 2006

A biologically active rhodamine conjugate of thyrotropin binds at 4°C to diffusely distributed membrane thyrotropin receptors which patch and become endocytosed into thyroid cells in a temperature-sensitive process. When the cells are first incubated with 8-bromo-cyclic adenosine monophosphate at 37°C, the conjugate also binds to clustered receptors at 4°C. Furthermore, 8-bromo-cyclic adenosine monophosphate reduces the amount of adenosine 3′,5′-monophosphate (cyclic AMP) induced by thyrotropin. Hence, increased intracellular cyclic AMP induces receptor patching and reduces the concentration of cyclic AMP normally induced by thyrotropin. This suggests that cyclic AMP acts both as the second messenger of thyrotropin and also as the regulator of the level of thyrotropin receptors.
Gonadotropin-Releasing Hormone: Regulation of Adenosine 3′,5′-Monophosphate in Ovarian Granulosa Cells
Authors: Knecht Michael , Catt Kevin J.
Published: October 2006

The antigonadal effects of gonadotropin-releasing hormone in ovarian granulosa cells are due to attenuation of the adenosine 3′,5′-monophosphate (cyclic AMP) response to follicle-stimulating hormone. Agonists of gonadotropin-releasing hormone progressively inhibit adenylate cyclase and stimulate phosphodiesterase activities in cultured granulosa cells, indicating that blockade of gonadotropin action is attributable to the combined effects of decreased production and increased degradation of cyclic AMP.
DNA Strand Breakage in Human Leukocytes Exposed to a Tumor Promoter, Phorbol Myristate Acetate
Authors: Birnboim H. C.
Published: October 2006

The phorbol myristate acetate-stimulated respiratory burst in human peripheral blood leukocytes is associated with extensive DNA strand breakage. Damage to DNA occurs before gross cellular damage is evident and may be related to the action of phorbol myristate acetate as a skin tumor promoter in animals.
Infrared Spectrum of the Purple Membrane: Clue to a Proton Conduction Mechanism?
Authors: Krimm S. , Dwivedi A. M.
Published: October 2006

The infrared spectrum of the purple membrane of
Halobacterium halobium
has amide I and amide A frequencies that are anomalously high for standard α-helical structures. Normal mode calculations indicate that these and other unusual features of the spectrum can be attributed to α
11
-helices. Such structures suggest that the helix backbone may provide the framework through which proton transport takes place.
Human β-Globin Gene Sequences Injected into Mouse Eggs, Retained in Adults, and Transmitted to Progeny
Authors: Steward Timothy A. , Wagner Erwin F. , Mintz Beatrice
Published: October 2006

Foreign gene sequences were retained in two adult mice (out of 62 analyzed) from fertilized eggs injected with a recombinant plasmid containing the human β-globin genomic region and the herpes simplex viral thymidine kinase gene. The intact human and viral genes were found in DNA of one of the animals and, in the other, at least part of the human globin gene was present. The latter individual transmitted these sequences to its progeny in a Mendelian ratio. Thus, human DNA may be incorporated into the germ line of mice for in vivo studies of regulation of gene expression in development, genetic diseases, and malignancy.
Eye Movements of African Chameleons: Spontaneous Saccade Timing
Authors: Mates John W. B.
Published: October 2006

Despite asynchrony, saccades of left and right eyes of African chameleons had similar timing statistics. Prominent qualitative aspects of these statistics did not change if one or both eyes were masked. Evidently, an internal stochastic process regulated chameleon saccade generation.
Effect of Prolonged Illumination (Phototherapy) on Concentrations of Luteinizing Hormone in Human Infants
Authors: Dacou-Voutetakis C. , Anagnostakis D. , Matsaniotis N.
Published: October 2006

Concentrations of luteinizing hormone in the serums of human neonates were altered when the neonates were exposed to prolonged, intense illumination (phototherapy) with their eyes covered. Concentrations decreased after 48 to 72 hours of exposure, increased 6 to 9 days after phototherapy, and subsequently returned to levels similar to those of controls. These data suggest that light may affect pituitary-gonadal function in the human neonate.
Erythroid Progenitors Circulating in the Blood of Adult Individuals Produce Fetal Hemoglobin in Culture
Authors: Papayannopoulou Th. , Nakamoto B. , Buckley J. , Kurachi S. , Nute P. E. , Stamatoyannopoulos G.
Published: October 2006

Erythroid colonies, raised from erythroid stem cells circulating in the peripheral blood of normal adult individuals, synthesize considerable amounts of fetal hemoglobin. In cultures from persons with sickling disorders, amounts of hemoglobin F that are known to inhibit sickling in vivo are produced. The results provide evidence that primitive erythroid progenitors are able to express the hemoglobin F production program and that cultures of mononuclear cells of the adult blood can be used to investigate the mechanisms involved in regulation of γ-globin gene switching.
An Estrogen-Binding Protein and Endogenous Ligand in
Saccharomyces cerevisiae
: Possible Hormone Receptor System
Authors: Feldman David , Do Yung , Burshell Alan , Stathis Peter , Loose David S.
Published: October 2006

A protein macromolecule in the cytosol of the unicellular eukaryotic yeast
Saccharomyces cerevisiae
selectively binds the vertebrate estrogen hormone 17β-estradiol with high affinity. Lipid extracts of the yeast cells or the conditioned growth medium yield a substance that can bind competitively to the tritiated estradiol-binding sites in the yeast and to mammalian estrogen receptors. These findings suggest that the binding protein may be a primitive hormone receptor and that the lipid-extractable substance represents the endogenous ligand.
In Vivo Identification of the Transforming Gene Product of Simian Sarcoma Virus
Authors: Robbins Keith C. , Devare Sushilkumar G. , Reddy E. Premkumar , Aaronson Stuart A.
Published: October 2006

Simian sarcoma virus (SSV) deletion mutants were constructed from a molecular clone containing the entire infectious provirus. Transfection analysis of these mutants localized the SSV transforming gene to a small region of the viral genome encompassing its cell-derived sequence (v-
sis
). Antiserum to a peptide synthesized on the basis of the predicted amino acid sequence of the SSV transforming gene detected a 28,000-dalton protein that was specifically expressed in SSV transformed cells and that corresponded in size to that predicted from the v-
sis
coding sequence. The v-
sis
gene product designated p28

sis

was not a phosphoprotein, nor did it possess detectable protein kinase activity. These findings distinguish p28

sis

from a number of other retroviral
onc
proteins.
Tolerance Develops to the Disruptive Effects of Δ
9
-Tetrahydrocannabinol on Primate Menstrual Cycle
Authors: Smith Carol Grace , Almirez Ramona G. , Berenberg Jeffrey , Asch Ricardo H.
Published: October 2006

Long-term exposure of sexually mature female rhesus monkeys (
Macaca mulata
) to thrice weekly injections of Δ
9
-tetrahydrocannabinol resulted in a disruption of menstrual cycles that lasted for several months. This period was marked by an absence of ovulation and decreased basal concentrations of gonadotropin and sex steroids in the plasma. After this period, normal cycles and hormone concentrations were reestablished. These studies demonstrate that in rhesus monkeys subjected to long-term treatment with Δ
9
-tetrahydrocannabinol tolerance develops to the disruptive effects of the drug on the menstrual cycle.
Ectopic Pro-Opiolipomelanocortin: Sequence of cDNA Coding for β-Melanocyte-Stimulating Hormone and β-Endorphin
Authors: DeBold C. Rowan , Schworer Madge E. , Connor Thomas B. , Bird Robert E. , Orth David N.
Published: October 2006

A recombinant bacterial plasmid, pMS1, was constructed that contains 318 nucleotides complementary to a portion of pro-opiolipomelanocortin (proOLMC) messenger RNA from an ectopic adrenocorticotropin-producing tumor. The cloned complementary DNA insert, which contains the sequence that codes for all of the β-melanocyte-stimulating hormone and β-endorphin portions of proOLMC, as well as the 3′ nontranslated section, is identical to the genomic sequence. Hybridization of tumor proOLMC complementary DNA to RNA subjected to electrophoresis and transferred to a nitrocellulose filter revealed two proOLMC messenger RNA species in the tumor polyadenylated RNA, but only one in pituitary polyadenylated RNA. At least one of the tumor proOLMC messenger RNA's is similar, if not identical, to human pituitary proOLMC messenger RNA.
Simple Repeat Array in Epstein-Barr Virus DNA Encodes Part of the Epstein-Barr Nuclear Antigen
Authors: Hennessy Kevin , Heller Mark , van Santen Vicky , Kieff Elliott
Published: October 2006

The size of the Epstein-Barr virus (EBV) nuclear antigen (EBNA) in cells infected with different EBV isolates varies directly with the size of the EBV triplet repeat array, IR3. The isolate with the largest IR3 fragment has approximately 170 more codons than the isolates with the smallest IR3 fragment; it encodes an EBNA which is approximately 17,000 daltons larger than the smallest EBNA. The EBV IR3 encodes part of a 2-kilobase exon of a latently infected cell messenger RNA which must be translated into a repetitive amino acid domain of EBNA.
Genetic Mapping of the Mouse Proto-Oncogene c-
sis
to Chromosome 15
Authors: Kozak Christine A. , Sears Johnna F. , Hoggan M. David
Published: October 2006

The mouse homolog (c-
sis
) of the transforming gene of the simian sarcoma virus was mapped to chromosome 15 by the Southern blot analysis of DNA's from hamster-mouse somatic cell hybrids. Alterations in c-
sis
expression may thus play a role in the various murine neoplastic diseases characterized by rearrangements or duplications of chromosome 15.
Ethanol Modulation of Opiate Receptors in Cultured Neural Cells
Authors: Charness Michael E. , Gordon Adrienne S. , Diamond Ivan
Published: October 2006

The mouse neuroblastoma-rat glioma hybrid cell line NG108-15 was used to study the acute and chronic interaction of ethanol with intact neural cells. In the short term, ethanol inhibited opiate receptor binding, but after long-term exposure the cells exhibited an apparent adaptive increase in the number of opiate binding sites; this was reversible when ethanol was withdrawn. High concentrations of ethanol (200 m
M
) increased opiate binding after 18 to 24 hours, whereas lower concentrations (25 to 50 m
M
) produced similar changes after 2 weeks. This model system has potential for exploring the cellular and molecular mechanisms underlying ethanol intoxication, tolerance, and withdrawal.
The Thymus-Adrenal Connection: Thymosin Has Corticotropin-Releasing Activity in Primates
Authors: Healy David L. , Hodgen Gary D. , Schulte Heinrich M. , Chrousos George P. , Loriaux D. Lynn , Hall Nicholas R. , Goldstein Allan L.
Published: October 2006

Endotoxin-free thymosin fraction 5 elevated corticotropin, β-endorphin, and cortisol in a dose- and time-dependent fashion when administered intravenously to prepubertal cynomolgus monkeys. Two synthetic component peptides of thymosin fraction 5 had no acute effects on pituitary function, suggesting that some other peptides in thymosin fraction 5 were responsible for its corticotropin-releasing activity. In agreement with these observations, total thymectomy of juvenile macaques was associated with decreases in plasma cortisol, corticotropin, and β-endorphin. These findings indicate that the prepubertal primate thymus contains corticotropin-releasing activity that may contribute to a physiological immunoregulatory circuit between the developing immunological and pituitary-adrenal systems.
Insulin-Like Growth Factors: A Role in Growth Hormone Negative Feedback and Body Weight Regulation via Brain
Authors: Tannenbaum Gloria Shaffer , Guyda Harvey J. , Posner Barry I.
Published: October 2006

Intracerebroventricular administration of ILA's, a preparation enriched in insulin-like growth factors, caused a marked decrease in growth hormone secretory episodes and in body weight associated with reduced food intake over 24 hours. Central injection of insulin and bovine serum albumin had no such effects. These findings suggest that insulin-like growth factors play a role in growth hormone negative feedback and body weight regulation at the level of the central nervous system.
Glucose Stimulation of the Antilipolytic Effect of Insulin in Humans
Authors: Arner Peter , Bolinder Jan , Östman Jan
Published: October 2006

Dose-response studies of the inhibition of lipolysis by insulin in isolated human adipocytes were conducted with the use of a sensitive bioluminescent assay of glycerol release. The addition of glucose to the incubation medium was associated with an increase in insulin sensitivity and an increase in the maximum insulin effect. The results suggest that glucose plays an important role in regulating the antilipolytic action of insulin in humans.