bluuebunny/crossref_metadata_2025 huggingface dataset:
Conservation of the Duchenne Muscular Dystrophy Gene in Mice and Humans
Authors: Hoffman Eric P. , Monaco Anthony P. , Feener Chris C. , Kunkel Louis M.
Published: October 2006

A portion of the Duchenne muscular dystrophy (DMD) gene transcript from human fetal skeletal muscle and mouse adult heart was sequenced, representing approximately 25 percent of the total, 14-kb DMD transcript. The nucleic acid and predicted amino acid sequences from the two species are nearly 90 percent homologous. The amino acid sequence that is predicted from this portion of the DMD gene indicates that the protein product might serve a structural role in muscle, but the abundance and tissue distribution of the messenger RNA suggests that the DMD protein is not nebulin.
Generation of a Hybrid Sequence-Specific Single-Stranded Deoxyribonuclease
Authors: Corey D. R. , Schultz P. G.
Published: October 2006

The relatively nonspecific single-stranded deoxyribonuclease, staphylococcal nuclease, was selectively fused to an oligonucleotide binding site of defined sequence to generate a hybrid enzyme. A cysteine was substituted for Lys
116
in the enzyme by oligonucleotide-directed mutagenesis and coupled to an oligonucleotide that contained a 3′-thiol. The resulting hybrid enzyme cleaved single-stranded DNA at sites adjacent to the oligonucleotide binding site.
Relation Between Work and Phosphate Metabolite in the in Vivo Paced Mammalian Heart
Authors: Balaban R. S. , Kantor H. L. , Katz L. A. , Briggs R. W.
Published: October 2006

Nuclear magnetic resonance (NMR) spectroscopy was used to monitor, on a beat-to-beat basis, the concentration of creatine phosphate and adenosine triphosphate during alterations in the work output of canine hearts in vivo. Over a wide range of rate-pressure products (5,000 to 25,000 mmHg/min), the relative amounts of creatine phosphate and adenosine triphosphate within the heart remained constant. The relative concentration of free adenosine diphosphate was calculated under the reasonable assumption that the creatine kinase-catalyzed reaction is near equilibrium in this tissue. The free concentration of adenosine diphosphate also did not change over this range of rate-pressure products. The data demonstrate that the concentration of these compounds is highly regulated in vivo and suggest that factors other than their concentration may be involved in the modulation of steady-state myocardial work output with oxygen consumption.
Acetylcholine Receptor Synthesis in Retina and Transport to Optic Tectum in Goldfish
Authors: Henley J. M. , Lindstrom J. M. , Oswald R. E.
Published: October 2006

Previous studies have suggested that the retinotectal system of the goldfish contains a nicotinic acetylcholine receptor (nAChR) that is sensitive to α-bungarotoxin. Extracellularly recorded field potentials elicited in response to visual stimulation can be blocked by α-bungarotoxin, and α-bungarotoxin can interfere with the maintenance of retinotectal synaptic connections. Whether the transmission between the retinal ganglion cells and the tectal cells is mediated by acetylcholine and whether nAChR's exist on the dendrites of tectal cells are questions that remain. The experiments described in this report were designed to determine the site of synthesis of the nAChR's associated with the goldfish retinotectal projection. Radioactive (35S-labeled) methionine was injected into either the eye or the tectal ventricle, and the incorporation of radioactivity into the nAChR was measured by immunoprecipitation. The use of this technique provides evidence that an nAChR associated with the goldfish retinotectal projection is synthesized in the retina and transported to the optic tectum, which suggests a presynaptic site of acetylcholine action on retinal terminals.
Curvilinear, Three-Dimensional Motion of Chromatin Domains and Nucleoli in Neuronal Interphase Nuclei
Authors: De Boni Umberto , Mintz Arlan H.
Published: October 2006

The term "nuclear rotation" refers to a motion of nucleoli within interphase nuclei of several cell types. No mechanism or function has been ascribed to this phenomenon, and it was unknown whether nuclear structures in addition to nucleoli participate in this motion. Moreover, it was unclear whether nuclear rotation occurs independent of concurrent motion of juxtanuclear cytoplasm. The work reported here presents quantitative evidence, for three-dimensional intranuclear, tandem motion of fluorescently labeled chromatin domains associated with nucleoli and those remote from nucleoli. The results show that such motion is curvilinear, that it is not restricted to nucleoli, and, moreover, that it occurs independently of motion of juxtanuclear, cytoplasmic structures. These results suggest that this motion represents karyoplasmic streaming and its function is to transpose to nuclear pores those chromatin domains actively transcribed.
Isolation of a Spirochete from the Soft Tick,
Ornithodoros coriaceus
: a Possible Agent of Epizootic Bovine Abortion
Authors: Lane Robert S. , Burgdorfer Willy , Hayes Stanley F. , Barbour Alan G.
Published: October 2006

A
Borrelia
-like spirochete was detected in all three parasitic stages of
Ornithodoros coriaceus
, the soft tick implicated in the epizoology of epizootic bovine abortion. After the spirochete had been isolated, its distinctness from other North American tick-borne borreliae as well as from
Spirochaeta aurantia
,
Treponema pallidum
, and
Leptospira interrogans
serovar pomona was established on the basis of its morphology, protein components, and inability to infect mice. The spirochete is passed trans-stadially and via eggs by ticks, and it is also excreted in coxal fluid after ticks have fed and detached. Circumstantial evidence suggests that the spirochete may be causally related to epizootic bovine abortion.
Hu-
ets
-1 and Hu-
ets
-2 Genes Are Transposed in Acute Leukemias with (4;11) and (8;21) Translocations
Authors: Sacchi Nicoletta , Watson Dennis K. , van Kessel Ad H. M. Guerts , Hagemeijer Anne , Kersey John , Drabkin Harry D. , Patterson David , Papas Takis S.
Published: October 2006

Human probes identifying the cellular homologs of the v-
ets
gene, Hu-
ets
-1 and Hu-
ets
-2, and two panels of rodent-human cell hybrids were used to study specific translocations occurring in acute leukemias. The human
ets
-1 gene was found to translocate from chromosome 11 to 4 in the t(4;11)(q21;23), a translocation characteristic of a subtype of leukemia that represents the expansion of a myeloid/lymphoid precursor cell. Similarly, the human
ets
-2 gene was found to translocate from chromosome 21 to chromosome 8 in the t(8;21)(q22;q22), a nonrandom translocation commonly found in patients with acute myeloid leukemia with morphology M2 (AML-M2). Both translocations are associated with expression different from the expression in normal lymphoid cells of
ets
genes, raising the possibility that these genes play a role in the pathogenesis of these leukemias.
X-Ray Diffraction from Magnetically Oriented Solutions of Macromolecular Assemblies
Authors: Glucksman Marc J. , Hay R. D. , Makowski Lee
Published: October 2006

A simple system was developed for obtaining x-ray diffraction patterns from magnetically oriented solutions of macromolecular assemblies. A small permanent magnet was designed that produces a magnetic field of 16 kilogauss in a volume of 1 cubic millimeter and is mountable on most x-ray cameras. Many subcellular structures have sufficient diamagnetic anisotropy that they exhibit orientation in dilute solution when placed between the poles of the magnet. Diffraction from solutions oriented in this magnet can provide substantially more structural information than small-angle scattering from isotropic solutions. In favorable cases, such as dilute solutions of filamentous bacteriophages, it is possible to produce oriented fiber diffraction patterns from which intensities along layer lines can be measured to 7-angstrom resolution. The magnetically induced birefringence observed in solutions of other macromolecular assemblies suggests that this technique may have broad applicability to subcellular structures.
The Neuroendocrine Thymus: Coexistence of Oxytocin and Neurophysin in the Human Thymus
Authors: Geenen Vincent , Legros Jean-Jacques , Franchimont Paul , Baudrihaye Marc , Defresne Marie-Paule , Boniver Jacques
Published: October 2006

Immunoreactive oxytocin and neurophysin were identified and measured by radioimmunoassay in human thymus extracts. Serial dilutions of extracts paralleled the appropriate standard curves. Thymus-extracted oxytocin and neurophysin eluted in the same positions as reference preparations on Sephadex G-75. Authenticity of oxytocin was confirmed by biological assay and high-performance liquid chromatography analysis. In most instances, thymus contents of oxytocin and neurophysin were far greater than those expected from known circulating concentrations and declined with increasing age. The molar ratio of oxytocin to neurophysin in thymus was similar to that found in the hypothalamo-neurohypophyseal system, which strongly suggested with the other data a local synthesis of oxytocin. These findings indicate the presence of neurohypophyseal peptides in the human thymus and further support the concept of a neuroendocrine function integrated in an immune structure.
Electrical Sources in Human Somatosensory Cortex: Identification by Combined Magnetic and Potential Recordings
Authors: Wood Charles C. , Cohen David , Cuffin B. Neil , Yarita Masaru , Allison Truett
Published: October 2006

Magnetic fields and electrical potentials produced by neuronal activity have different properties that can be used for the identification of electrical sources in the human brain. Fields and potentials occurring 20 to 30 milliseconds after median nerve stimulation in human subjects were compared in order to investigate the sources of evoked potential components that have been attributed by different investigators to the thalamus or thalamocortical afferents, to separate radial sources in somatosensory cortex and motor cortex, or to a tangential source in somatosensory cortex. The magnetic and potential wave forms were highly similar in morphology, and their spatial distributions were centered over sensorimotor cortex, were dipolar in shape, and differed in orientation by approximately 90 degrees; distances between the minimum and maximum of the magnetic distributions were about 60 percent of those of the potential distributions. These results cannot be accounted for by thalamic sources or radial cortical sources alone, but are consistent with a tangential source in somatosensory cortex, with an additional smaller contribution from radial sources.
Dynamics and Conformational Energetics of a Peptide Hormone: Vasopressin
Authors: Hagler A. T. , Osguthorpe D. J. , Dauber-Osguthorpe P. , Hempel J. C.
Published: October 2006

A theoretical methodology for use in conjunction with experiment was applied to the neurohypophyseal hormone lysine vasopressin for elucidation of its accessible molecular conformations and associated flexibility, conformational transitions, and dynamics. Molecular dynamics and energy minimization techniques make possible a description of the conformational properties of a peptide in terms of the precise positions of atoms, their fluctuations in time, and the interatomic forces acting on them. Analysis of the dynamic trajectory of lysine vasopressin shows the ability of a flexible peptide hormone to undergo spontaneous conformational transitions. The excursions of an individual phenylalanine residue exemplify the dynamic flexibility and multiple conformational states available to small peptide hormones and their component residues, even within constraints imposed by a cyclic hexapeptide ring.
Leukotriene C
4
Transport by the Choroid Plexus in Vitro
Authors: Spector Reynold , Goetzl Edward J.
Published: October 2006

Nanomolar concentrations of peptidoleukotrienes evoke sustained cerebral edema and arterial constriction. Peptidoleukotrienes are thus considered to play an important role in eliciting cerebral edema after cerebral ischemia and vasospasm after subarachnoid hemorrhage. It was hypothesized that the choroid plexus, the locus of the blood-cerebrospinal fluid barrier, might minimize the vasoactivity of locally generated or systemically derived leukotrienes by transporting leukotrienes from cerebrospinal fluid into the blood. Consistent with this hypothesis, leukotriene C
4
in vitro was transported into and released from isolated rabbit choroid plexus by a system that was specific, energy-dependent, probenecid-sensitive, and depressed by cold temperatures. The accumulation of leukotriene C
4
in the choroid plexus was not dependent on tissue binding or metabolism of leukotriene C
4
.
Trigeminal-Taste Interaction in Palatability Processing
Authors: Berridge Kent C. , Fentress John C.
Published: October 2006

Peripheral transection of the sensory branches of the trigeminal nerve in rats unbalanced palatability, selectively reducing the ingestive actions elicited by preferred tastes but leaving unchanged the aversive actions elicited by unpreferred tastes. The reduction in the number of positive ingestive actions occurred even though the capacity to emit these actions remained unimpaired. These findings show that there is an interaction between somatosensation and gustation in the processing of palatability.
Primate Model for Long-Term Study of Intraventricularly or Intrathecally Administered Drugs and Intracranial Pressure
Authors: Wood James H. , Poplack David G. , Bleyer Werner A. , Ommaya Ayub K.
Published: October 2006

Meaningful pharmacokinetic investigations require animal systems which approximate the human situation. This report describes a primate model in which silicone catheters are placed into the fourth ventricle and the spinal subarachnoid space and connected to subcutaneous cerebrospinal fluid reservoirs. This model permits sterile access to ventricular cerebrospinal fluid without tissue damage, provides mixing of injected drugs with lateral ventricular cerebrospinal fluid, enables spinoventricular perfusion, and permits ventricular cerebrospinal fluid sampling over extended periods in unanesthetized rhesus monkeys. This animal system may provide intraventricular pressure recordings and pharmacokinetic data similar to that obtained in man.
The Structure of Arthropod Hemocyanins
Authors: Linzen B. , Soeter N. M. , Riggs A. F. , Schneider H.-J. , Schartau W. , Moore M. D. , Yokota E. , Behrens P. Q. , Nakashima H. , Takagi T. , Nemoto T. , Vereijken J. M. , Bak H. J. , Beintema J. J. , Volbeda A. , Gaykema W. P. J. , Hol W. G. J.
Published: October 2006

Hemocyanins are large multi-subunit copper proteins that transport oxygen in many arthropods and molluscs. Comparison of the amino acid sequence data for seven different subunits of arthropod hemocyanins from crustaceans and chelicerates shows many highly conserved residues and extensive regions of near identity. This correspondence can be matched closely with the three domain structure established by x-ray crystallography for spiny lobster hemocyanin. The degree of identity is particularly striking in the second domain of the subunit that contains the six histidines which ligate the two oxygen-binding copper atoms. The polypeptide architecture of spiny lobster hemocyanin appears to be the same in all arthropods. This structure must therefore be at least as old as the estimated time of divergence of crustaceans and chelicerates, about 540 to 600 million years ago.
Antibody-Directed Urokinase: A Specific Fibrinolytic Agent
Authors: Bode Christoph , Matsueda Gary R. , Hui Kwan Y. , Haber Edgar
Published: October 2006

A specific fibrinolytic agent was synthesized by covalently coupling urokinase to a monoclonal antibody that was fibrin-specific and did not cross-react with fibrinogen. The antibody was raised against a synthetic peptide representing the seven amino-terminal residues of the beta chain of human fibrin. The urokinase-antifibrin conjugate retained the original binding specificity of the antibody and showed 100-fold increased fibrinolysis in vitro when compared to unmodified urokinase. The presence of human fibrinogen at plasma concentration did not influence these properties.
Control of Sequential Compartment Formation in
Drosophila
Authors: Kauffman Stuart A. , Shymko Ronald M. , Trabert Kenneth
Published: October 2006

During development of
Drosophila melanogaster
, sequential commitment to alternative development programs occurs in neighboring groups of cells. These commitments appear to be reflected by lines of clonal restriction, called compartmental boundaries, which progressively subdivide the early embryo, and later the imaginal discs, which give rise to different adult appendages. We propose that a reaction-diffusion system acts throughout development and generates a sequence of differently shaped chemical patterns. These patterns account for the sequence and geometries of compartmental boundaries, and predict that each terminal compartment is specified by a unique combination of binary choices made during its formation. This binary "code" interprets coherently the patterned metaplasia seen in transdetermination and homeotic mutations.
Functional Plasticity in the Immature Striate Cortex of the Monkey Shown by the [
14
C]Deoxyglucose Method
Authors: Des Rosiers M. H. , Sakurada O. , Jehle J. , Shinohara M. , Kennedy C. , Sokoloff L.
Published: October 2006

Autoradiographic representation of the local rates of cerebral glucose utilization and local cerebral functional activity by means of the [
14
C]deoxyglucose technique reveals the existence of the ocular dominance columns in the striate cortex of the monkey in the first day of life. In contrast to the stability of these columns in more mature brain, monocular deprivation for 3 months from the first day of life results in their complete disappearance and a reversion of the autoradiographic pattern to that seen in animals with normal binocular vision. These results are consistent with a reorganization of the representation of the visual fields of the two eyes in the striate cortex and provide additional evidence of the plasticity of the striate cortex of the monkey in early life.
Defects of Bile Acid Synthesis in Zellweger's Syndrome
Authors: Hanson Russell F. , Szczepanik-VanLeeuwen Patricia , Williams Gale C. , Grabowski Gregory , Sharp Harvey L.
Published: October 2006

Abnormal mitochondrial structure and function have been documented in patients with Zellweger's syndrome (cerebrohepatorenal syndrome). In vitro studies have suggested that the formation of C
24
bile acids (chenodeoxycholic acid and cholic acid) from C
27
cholesterol requires mitochondrial oxidative cleavage of the terminal three carbons of the side chain. Therefore, three patients with Zellweger's syndrome were examined for the presence of mitochondrial defects in bile acid synthesis. All three excreted excessive amounts of 3α, 7α-dihydroxy-5β-cholestan-26-oic acid, 3α, 7α, 12α-trihydroxy-5β-cholestan-26-oic acid, and 3α, 7α, 12α, 24ξ-tetrahydroxy-5β-cholestan-26-oic acid (varanic acid), precursors of chenodeoxycholic acid and cholic acid that have undergone only partial side chain oxidation. These findings give added support to the role of mitochondrial oxidative side chain cleavage in the overall scheme of bile acid synthesis.
L Amino Acids and D-Glucose Bind Stereospecifically to a Colloidal Clay
Authors: Bondy Stephen C. , Harrington Marilyn E.
Published: October 2006

L-Leucine, L-aspartate, and D-glucose bind in a stereospecific manner to a colloidal clay, bentonite. This binding has high-affinity, saturable characteristics. The biologically uncommon enantiomers, D-leucine, D-asparatate, and L-glucose, do not exhibit any selective absorption on bentonite. It is suggested that this difference between stereoisomers could account for the evolution of life forms possessing a great preponderance of L amino acids and D-glucose.
Flow Cytometry: A High-Resolution Instrument for Everyone
Authors: Steen Harald B. , Lindmo Tore
Published: October 2006

A new flow configuration for flow cytometry has been devised in which a flat, laminar stream of water, containing the stained cells in a narrow central sector, is formed on a microscope cover slip by a pressurized jet of water directed onto the glass at low angle. The stream of cells is viewed by means of a fluorescence microscope with incident illumination and a pulse photometer. Coupled to a multichannel pulse height analyzer, the instrument constitutes a stable and easy-to-operate flow cytometer with a resolution equal to or better than a coefficient of variance of 1.4 percent in measurements of cellular DNA.
Linkage of Loci Controlling Alloantigens on Red Blood Cells and Lymphocytes in the Horse
Authors: Bailey Ernest , Stormont Clyde , Suzuki Yoshiko , Trommershausen Smith Ann
Published: October 2006

A system of equine lymphocyte alloantigens designated ELA, is identified, and it is shown that the locus or loci controlling these markers must be closely linked to the locus controlling markers in the A system of horse blood groups. Among 29 offspring in two stallion families there was evidence for one recombinant. Lod scores for linkage between the A and ELA loci in the two families were 3.61 and 3.33, respectively, for θ equal to 0.
Nonpneumonic, Short-Incubation-Period Legionellosis (Pontiac Fever) in Men Who Cleaned a Steam Turbine Condenser
Authors: Fraser David W. , Deubner David C. , Hill Dianne L. , Gilliam Darrell K.
Published: October 2006

Pontiac fever affected ten men who had cleaned a steam turbine condenser with compressed air. Previous epidemics of Pontiac fever and Legionnaires' disease—both caused by
Legionella pneumophila
(proposed sp. nov.)—involved "airborne spread" from air-conditioning cooling towers or evaporative condensers. Aerosols of contaminated water in heat-rejection systems appear to be important sources of epidemic legionellosis.
Differential Behavioral and Biochemical Effects of Right and Left Hemispheric Cerebral Infarction in the Rat
Authors: Robinson Robert G.
Published: October 2006

Following ligation of the right middle cerebral artery, rats were hyperactive for 2 to 3 weeks whether activity was measured by running wheel revolutions or open field observations. Assays of brain catecholamines revealed 30 percent reductions of norepinephrine in the injured and uninjured cortex and locus coeruleus and a 20 percent reduction of dopamine in the substantia nigra. In contrast, rats with left middle cerebral artery ligations did not become hyperactive and did not show any significant change in catecholamines in any of the brain areas studied. Right and left hemispheric infarctions were comparable in their locations and extent of tissue damage. This lateralization of behavioral and biochemical response to cerebral infarction may be the consequence of anatomical or physiological asymmetries in the brain.
Emergence of Interoceptive and Exteroceptive Control of Behavior in Rats
Authors: Haroutunian Vahram , Campbell Byron A.
Published: October 2006

The role of exteroceptive and interoceptive aversive stimuli in rats 2 to 14 days old was investigated according to an odor aversion paradigm. Amyl acetate odor was paired with either peripheral shock, intraperitoneal shock, or lithium chloride poisoning. Intraperitoneal shock was an effective unconditioned stimulus at all ages and produced odor aversions comparable to lithium chloride poisoning; peripheral shock, however, was effective only in rats 10 days of age or older. Interoceptive control of aversively motivated behaviors thus seems to develop before exteroceptive control, and the failure of previous studies to find reliable learning and retention of shock-motivated behaviors before 8 to 10 days of age may be attributable to the site to which shock was applied rather than to insensitivity to shock per se.
The Central Origin of Efferent Pathways in the Carotid Sinus Nerve of the Cat
Authors: deGroat W. C. , Nadelhaft I. , Morgan C. , Schauble T.
Published: October 2006

The application of horseradish peroxidase to the central cut end of the carotid sinus nerve of the cat produced retrograde labeling of neurons in the ipsilateral medulla in the region of the nucleus ambiguus at anterior-posterior coordinates -8 to -10.5. These data coupled with previous electrophysiological observations suggest that the nucleus ambiguus may be the origin of an efferent inhibitory pathway to the carotid body.
Delay of Constant Light-Induced Persistent Vaginal Estrus by 24-Hour Time Cues in Rats
Authors: Weber Anita L. , Adler Norman T.
Published: October 2006

The normal ovarian cycle of female rats is typically replaced by persistent estrus when these animals are housed under constant light. Evidence presented here shows that the maintenance of periodicity in the environment can at least delay (if not prevent) the photic induction of persistent vaginal estrus. Female rats in constant light were exposed to vaginal smearing at random times or at the same time every day. In another experiment, female rats were exposed to either constant bright light, constant dim light, or a 24-hour photic cycle of bright and dim light. The onset of persistent vaginal estrus was delayed in rats exposed to 24-hour time cues even though the light intensities were the same as or greater than those for the aperiodic control groups. The results suggest that the absence of 24-hour time cues in constant light contributes to the induction of persistent estrus.
Lymphoma in Macaques: Association with Virus of Human T Lymphotrophic Family
Authors: Homma T. , Kanki P. J. , King N. W. , Hunt R. D. , O'Connell M. J. , Letvin N. L. , Daniel M. D. , Desrosiers R. C. , Yang C. S. , Essex M.
Published: October 2006

Human T-cell leukemia virus has been linked with adult T-cell leukemia-lymphoma (ATLL), a tumor of mature T cells that occurs at elevated rates in southwestern Japan and in the Caribbean Basin. Human T-cell leukemia virus (HTLV) or a closely related virus, has also been found in varying proportions of healthy individuals of several species of Old World monkeys. In the present study, conducted with macaques from Taiwan and the New England Regional Primate Research Center, antibodies to membrane antigens of HTLV-infected cells (HTLV-MA) were found in 11 of 13 macaques with malignant lymphoma or lymphoproliferative disease but in only 7 of 95 of healthy macaques. This indicates that antibodies to HTLV are significantly associated with the development of naturally occurring lymphoid neoplasms in at least some species of nonhuman primates.
Direct Demonstration of Impaired Functionality of a Purified Desensitized β-Adrenergic Receptor in a Reconstituted System
Authors: Strulovici Berta , Cerione Richard A. , Kilpatrick Brian F. , Caron Marc G. , Lefkowitz Robert J.
Published: October 2006

Long-term exposure of various cell types to β-adrenergic agonists such as isoproterenol leads to an attenuated responsiveness ("desensitization") of the adenylate cyclase system to further challenge with these agonists. The turkey erythrocyte model system was used earlier to show that a covalent modification of the receptor (phosphorylation) is associated with this process. The functionality of the "desensitized" β-adrenergic receptor was assessed by implanting purified β-adrenergic receptor preparations from control and desensitized turkey erythrocytes into phospholipid mixtures and then fusing them with receptor-deficient cells (Xenopus laevis erythrocytes). Desensitized β-adrenergic receptors showed a 40 to 50 percent reduction in their ability to couple to the heterologous adenylate cyclase system, comparable to the reduction in their functionality observed in their original membrane environment. These results demonstrate the utility of recently developed receptor reconstitution techniques for assessing the functionality of purified receptors and show a direct link between a covalent modification of a membrane-bound receptor and its impaired functionality in a reconstituted system.
DNA Markers for Nervous System Diseases
Authors: Gusella James F, , Tanzi Rudolph E. , Anderson Mary Anne , Hobbs Wendy , Gibbons Kerin , Raschtchian Roya , Gilliam T. Conrad , Wallace Margaret R. , Wexler Nancy S. , Conneally P. Michael
Published: October 2006

Recombinant DNA technology has provided a vast new source of DNA markers displaying heritable sequence variation in humans. These markers can be used in family studies to identify the chromosomal location of defective genes causing nervous system disorders. The discovery of a DNA marker linked to Huntington's disease has opened new avenues of research into this disorder and may ultimately permit cloning and characterization of the defective gene.
Transmission of HTLV-III Infection from Human Plasma to Chimpanzees: An Animal Model for AIDS
Authors: Alter Harvey J. , Eichberg Jorg W. , Masur Henry , Saxinger W. Carl , Gallo Robert , Macher Abe M. , Lane H. Clifford , Fauci Anthony S.
Published: October 2006

Two of three chimpanzees given plasma from patients with acquired immune deficiency syndrome (AIDS) or pre-AIDS showed serum antibodies to type III human T-cell leukemia virus (HTLV-III) 10 to 12 weeks after transfusion. One animal also developed lymphadenopathy, transient depression of the ratio of T4 to T8 lymphocytes, and impaired blastogenic responses. No opportunistic infections occurred. Adenopathy persisted for 32 weeks, and antibody to HTLV-III persisted for at least 48 weeks. This transmission of HTLV-III by lymphocyte-poor plasma confirms the potential risk of such plasma or plasma derivatives to recipients. The susceptibility of the chimpanzee to HTLV-III infection and the ability to simulate the human lymphadenopathy syndrome in this animal makes it a valuable model for further study of AIDS.
Blockade of
N
-Methyl-D-Aspartate Receptors May Protect Against Ischemic Damage in the Brain
Authors: Simon R. P. , Swan J. H. , Griffiths T. , Meldrum B. S.
Published: October 2006

In rats ischemia of the forebrain induced by a 30-minute occlusion of the carotid artery, followed by 120 minutes of arterial reperfusion, produced ischemic lesions of selectively vulnerable pyramidal cells in both hippocampi. Focal microinfusion into the dorsal hippocampus of 2-amino-7-phosphonoheptanoic acid, an antagonist of excitation at the
N
-methyl-D-aspartate-preferring receptor, before ischemia was induced protected against the development of ischemic damage. It is proposed that excitatory neurotransmission plays an important role in selective neuronal loss due to cerebral ischemia.
Early Morning Insomnia with Rapidly Eliminated Benzodiazepines
Authors: Kales Anthony , Soldatos Constantin R. , Bixler Edward O. , Kales Joyce D.
Published: October 2006

Early morning insomnia, a significant increase in wakefulness during the final hours of drug nights, occurred after 1 or 2 weeks of nightly administration of benzodiazepine hypnotics with short elimination half-lives, when tolerance had begun to develop. Early morning insomnia may be a variant of rebound insomnia and therefore specific to benzodiazepines, or it may occur with any rapidly eliminated sedative-hypnotic agent.
Brain Peptides: What, Where, And Why?
Authors: Krieger Dorothy T.
Published: October 2006

Within the past decade, a large number of peptides have been described within the vertebrate central nervous system. Some of these peptides were previously known to be present in nonneural vertebrate tissues, as well as in lower species, in which they may serve as primitive elements of intercellular communication prior to the development of neuronal or endocrine systems. In vertebrates, these peptides are thought to have neurotransmitter or neuromodulatory roles and appear to be involved in the regulation of a number of homeostatic systems, although the mechanisms of their actions are still unclear.
F-Cell Production in Sickle Cell Anemia: Regulation by Genes Linked to β-Hemoglobin Locus
Authors: Dover George J. , Boyer Samuel H. , Pembrey Marcus E.
Published: October 2006

Strong correlation of F-reticulocyte levels within sib pairs with sickle cell (SS) anemia suggests that the wide-ranging levels found in the SS population are governed by genes linked to the β
S
-site. Correlations between F-cell levels in parents and F-reticulocyte levels in their children indicates that these same genes regulate F-cell production in nonanemic persons. Comparison of outcrossed and inbred SS populations suggests that relative well-being arises from homozygosity for alleles dictating high F-reticulocyte response to anemia.
Human Lupus Inclusions and Interferon
Authors: Rich Steven A.
Published: October 2006

Raji cells, a human B lymphoblastoid cell line of Burkitt lymphoma origin, formed lupus inclusions when grown in a medium conditioned by the growth of Raji cells whose DNA thymidine residues had been unifilarly (single-strandedly) substituted with bromodeoxyuridine. Ultracentrifugation of this medium in excess of that required to remove Epstein-Barr virus and all other known mammalian viruses did not prevent the formation of the inclusions, and treatment of the conditioned medium with pronase destroyed the activity. These results demonstrate the presence of a protein that is secreted from bromodeoxyuridine-substituted Raji cells and is capable of inducing nonbromodeoxyuridine-substituted cells to form lupus inclusions. Interferon (100 units per milliliter) was found in the conditioned medium. Inclusions also formed in Raji cells grown in fresh medium supplemented with human leukocyte or fibroblast interferon (100 units per milliliter).
Linkage Analysis of Nondeletion Hereditary Persistence of Fetal Hemoglobin
Authors: Old J. M. , Ayyub H. , Wood W. G. , Clegg J. B. , Weatherall D. J.
Published: October 2006

Nondeletion forms of hereditary persistence of fetal hemoglobin may result from regulatory disorders of globin gene expression. The defects in two such conditions were localized by demonstrating a tight genetic linkage between the disorders and polymorphic restriction endonuclease sites within the β-like globin gene complex. In one instance, the defect probably occurred outside the region of DNA between the ε- and β-globin genes.
Down's Syndrome in Adults: Brain Metabolism
Authors: Schwartz M. , Duara R. , Haxby J. , Grady C. , White B. J. , Kessler R. M. , Kay A. D. , Cutler N. R. , Rapoport S. I.
Published: October 2006

The cerebral metabolic rate for glucose, as measured with positron emission tomography and fluorine-18-labeled 2-deoxy-D-glucose, was significantly higher in four healthy young subjects with trisomy 21 syndrome (Down's syndrome) than the mean rate in healthy young controls. The rate of cerebral glucose utilization in the frontal lobe of a 51-year-old subject with Down's syndrome was significantly lower than the rate in the young subjects with this syndrome, but approximated the rate in middle-aged controls. Thus glucose utilization by the brain appears to be excessive in young adults with Down's syndrome but may decline with age in some brain regions.
Human Rotavirus Type 2: Cultivation in Vitro
Authors: Wyatt Richard G. , James Walter D. , Bohl Edward H. , Theil Kenneth W. , Saif Linda J. , Kalica Anthony R. , Greenberg Harry B. , Kapikian Albert Z. , Chanock Robert M.
Published: October 2006

A strain of type 2 human rotavirus (Wa) was grown to relatively high titer through 14 passages in primary cultures of African green monkey kidney (AGMK) cells. This passage series was initiated with virus that had been passaged 11 times serially in newborn gnotobiotic piglets. In contrast, virus present in the stool of patient Wa as well as virus from the first, second, or third passage in piglets could not be propagated successfully in African green monkey kidney cells. Prior to each passage in cell culture, the virus was treated with trypsin and the inoculated cultures were centrifuged at low speed. Cultivation of a type 2 human rotavirus should aid attempts to characterize this virus and to develop a means of immunoprophylaxis for a serious diarrheal disease of human infants.
Cell Growth with
trans
Fatty Acids Is Affected by Adenosine 3′,5′-monophosphate and Membrane Fluidity
Authors: Tsao Yuan-Kai , Lands William E. M.
Published: October 2006

Two positional isomers (9 and 11) of
trans
octadecenoates did not support growth on glucose of an
Escherichia coli
mutant that requires unsaturated fatty acids. However, the
trans
fatty acids provided sufficient fluidity to produce much higher cell yields when the concentration of adenosine 3′,5′-monophosphate was raised. The effectiveness of the
trans
acids rose from 0 to 1 cell per femtomole to 15 to 20 cells per femtomole as the concentration of adenosine 3′,5′-monophosphate was increased. The corresponding
cis
positional isomers supported high yields (35 to 40 cells per femtomole) independent of supplementation. The enhanced growth with adenosine 3′,5′-monophosphate supplementation is not due to an increased uptake and incorporation of the
trans
isomers relative to the
cis
isomers, since the 9-
trans
isomer was incorporated more rapidly than the 9-
cis
isomer into the membrane phospholipids under all growth conditions and represented 21 ± 2 mole percent of the acids. The finding that cells growing with
trans
fatty acid isomers have a higher requirement for adenosine 3′,5′-monophosphate may indicate that some fatty acids can alter the metabolic regulation normally exerted by the cyclic nucleotide.
DNA Gyrase and the Supercoiling of DNA
Authors: Cozzarelli Nicholas R.
Published: October 2006

Negative supercoiling of bacterial DNA by DNA gyrase influences all metabolic processes involving DNA and is essential for replication. Gyrase supercoils DNA by a mechanism called sign inversion, whereby a positive supercoil is directly inverted to a negative one by passing a DNA segment through a transient double-strand break. Reversal of this scheme relaxes DNA, and this mechanism also accounts for the ability of gyrase to catenate and uncatenate DNA rings. Each round of supercoiling is driven by a conformational change induced by adenosine triphosphate (ATP) binding: ATP hydrolysis permits fresh cycles. The inhibition of gyrase by two classes of antimicrobials reflects its composition from two reversibly associated subunits. The A subunit is particularly associated with the concerted breakage-and-rejoining of DNA and the B subunit mediates energy transduction. Gyrase is a prototype for a growing class of prokaryotic and eukaryotic topoisomerases that interconvert complex forms by way of transient double-strand breaks.
β-Lipotropin: a New Aldosterone-Stimulating Factor
Authors: Matsuoka Hiroaki , Mulrow Patrick J. , Li Choh Hao
Published: October 2006

β-Lipotropin stimulated the production of aldosterone in collagenase-dispersed rat adrenal capsular cells. The maximum response obtained with β-lipotropin was the same as the response obtained with corticotropin and was greater than that obtained with angiotensin II. These data suggest that β-lipotropin may play a role in aldosterone regulation.
Teratocarcinomas and Mammalian Embryogenesis
Authors: Martin Gail R.
Published: October 2006

In the last decade there has emerged an appreciation of the remarkable similarity between the cells that give rise to teratocarcinomas in mice and the cells that give rise to the developing mouse embryo. The resemblance is so close that in certain instances the tumor stem cells can join with their embryonic counterparts and develop into a completely normal mouse. The availability of stem cell lines isolated from mouse teratocarcinomas has made possible a number of new biochemical, immunological, and genetic approaches to the study of early mammalian development.
Stereoisomers of
N
-Allylnormetazocine: Phencyclidine-Like Behavioral Effects in Squirrel Monkeys and Rats
Authors: Brady Kathleen T. , Balster Robert L. , May Everette L.
Published: October 2006

(±)-
N
-Allylnormetazocine is a benzomorphan opioid with psychotomimetic effects. The pure stereoisomers of this compound, as well as the racemic mixture, were compared to phencyclidine for their behavioral effects on squirrel monkeys and rats trained to discriminate phencyclidine from saline. Dose-response determinations were made for responses to phencyclidine, to a racemic mixture of
N
-allylnormetazocine, and to the pure levo and dextro isomers of
N
-allylnormetazocine. In both rats and monkeys, the dextro isomer and the racemic mixture produced dose-dependent responses appropriate for phencyclidine; the levo isomer did not produce the responses appropriate for phencyclidine at any of the doses tested. In both species, the levo isomer was more potent than the dextro isomer in decreasing the rate of responding. Thus racemic
N
-allylnormetazocine is a mixture of compounds that produce different behavioral effects.
Optokinetic Eye Movements in Albino Rabbits: Inversion in Anterior Visual Field
Authors: Collewijn Han , Winterson Barbara J. , Dubois Marc F. W.
Published: October 2006

When visual contrasts are restricted to the anterior sector (90° to 180°) of the albino rabbit's visual field, eye position is dramatically unstable, and when such contrasts are moved, horizontal optokinetic eye movements are inverted: the direction of pursuit is opposite to that of the stimulus. In the posterior visual field stability and optokinetic reactions are normal, as in all parts of the pigmented rabbit's visual field. This phenomenon may be one more of the complex of visual system defects linked to albinism.
Multiple Point Mutations Affecting the Simian Virus 40 Enhancer
Authors: Weiher Hans , König Monika , Gruss Peter
Published: October 2006

Enhancers, or activators, dramatically increase the transcriptional activity of certain eukaryotic genes. A series of multiple point mutations affecting the simian virus 40 (SV40) enhancer-activator region were generated in order to define the nucleotide sequence required for this function. Three independent assays provided information leading to the identification of nucleotides essential for enhancer function. One class leads to a decrease in gene expression, while the second completely abolishes functional activity. One critical replacement appears to be the first G (guanine) in a sequence TGGAAAG (T, thymine, A, adenine) located in the 5' region of the 72 base-pair repeat of SV40. Comparison of this sequence with nucleotide sequences in other known enhancers leads to the identification of potential related core elements.
High Efficiency DNA-Mediated Transformation of Primate Cells
Authors: Gorman Cornelia , Padmanabhan Raji , Howard Bruce H.
Published: October 2006

Tissue culture cells from several mammalian species, including three primate lines, were transfected with recombinant vectors carrying
Escherichia coli
xanthine-guanine phosphoribosyltransferase or T
n
5 aminoglycoside phosphotransferase dominant selectable markers. Human HeLa and SV40-transformed xeroderma pigmentosum cells exhibited stable transformation frequencies of at least 10
-3
(0.1 percent). CV-1, an African green monkey kidney cell line, could be stably transformed with the exceptionally high frequency of 6 × 10
-2
(6 percent).
Human Milk Kills Parasitic Intestinal Protozoa
Authors: Gillin Frances D. , Reiner David S. , Wang Chi-Sun
Published: October 2006

Giardia lamblia
, a common pathogenic intestinal parasite of humans, was rapidly killed by exposure to normal human milk in vitro. The killing did not depend on secretory immunoglobulin A.
Entamoeba histolytica
, the dysentery amoeba, was also killed by normal human milk.
Giardia
-cidal activity cochromatographed with an unusual lipase that is present in the milk of humans but not of lower mammals. Human milk may play a protective role in infants exposed to this parasite.
Phospholipase-Induced Crystallization of Channels in Mitochondrial Outer Membranes
Authors: Mannella Carmen A.
Published: October 2006

When outer membranes from
Neurospora crassa
mitochondria are treated with low levels of phospholipase A
2
under continuous dialysis, two-dimensional crystalline arrays of the pore protein component of these membranes are formed.
The Genus-Specific Antigen of
Chlamydia
: Resemblance to the Lipopolysaccharide of Enteric Bacteria
Authors: Nurminen Marjatta , Leinonen Maija , Saikku Pekka , Mäkelä P. Helena
Published: October 2006

A strong immunological cross-reaction between a major glycolipid antigen of
Chlamydia
and the innermost (Re) core of the lipopolysaccharide of enteric bacteria was demonstrated with the aid of mutants in which the Re structure is exposed. The chlamydial glycolipid resembled the Re lipopolysaccharide in molecular size, solubility, and endotoxic properties and may thus be functionally equivalent to lipopolysaccharide, an essential and characteristic component of the outer membrane of Gram-negative bacteria.
A Gene Controlling Condensation of Heterochromatin in
Drosophila melanogaster
Authors: Gatti Maurizio , Smith David A. , Baker Bruce S.
Published: October 2006

A temperature-sensitive lethal mutant of
Drosophila melanogaster
was used to identify an essential cell cycle function that is necessary for the mitotic condensation of heterochromatic but not of euchromatic portions of the genome. This mutant is an allele at a locus (
mus-101
) identified earlier by the use of mutagen-sensitive mutants. The data suggest that the mutagen-sensitive and repair-defective phenotypes of viable
mus-101
mutants result from a disruption in chromosome organization.
Heme-Heme Orientation and Electron Transfer Kinetic Behavior of Multisite Oxidation-Reduction Enzymes
Authors: Makinen Marvin W. , Schichman Steven A. , Hill Susan C. , Gray Harry B.
Published: October 2006

Analysis of the polarized single-crystal absorption spectra of cytochrome cd
1
of
Pseudomonas aeruginosa
shows that the heme c and heme d
1
groups in each subunit are oriented perpendicularly to each other in both oxidized and reduced forms of the enzyme. These results, together with those of previous kinetic studies, indicate that a perpendicular heme-heme orientation may be an important factor in specifying kinetically slow steps in a sequential series of electron transfer reactions.
Ribose Intervention in the Cardiac Pentose Phosphate Pathway Is Not Species-Specific
Authors: Zimmer Heinz-Gerd , Ibel Hans , Suchner Ulrich , Schad Hubert
Published: October 2006

Ribose is cardioprotective in the rat in a variety of pathophysiological conditions. The metabolic basis for this effect is the low capacity of the oxidative pentose phosphate pathway in the myocardium. Ribose bypasses this pathway, elevates the available pool of 5-phosphoribosyl-1-pyrophosphate, and thus stimulates the biosynthesis of adenine nucleotides. In the study reported here the activity of glucose-6-phosphate dehydrogenase, the first and rate-limiting enzyme of the oxidative pentose phosphate shunt, was very low in the human heart and was of the same order of magnitude in the myocardium of various animal species. Furthermore, ribose had a similar stimulating effect on myocardial adenine nucleotide biosynthesis in the guinea pig, in which hemodynamic parameters are different from those in the rat. It is concluded that the metabolic basis for the effectiveness of ribose is similar in all species investigated.
Growth Hormone-Releasing Factor: Direct Effects on Growth Hormone, Glucose, and Behavior Via the Brain
Authors: Tannenbaum Gloria Shaffer
Published: October 2006

Intracerebroventricular administration of human pancreatic growth hormone-releasing factor caused a dose-dependent inhibition of growth hormone secretion, elevated plasma glucose concentrations, and produced marked behavioral and motor effects. Immunoneutralization with antiserum to somatostatin did not reverse the suppression of growth hormone. These findings suggest that hypothalamic growth hormone-releasing factor may regulate its own neurosecretion through an "ultrashort-loop" negative feedback mechanism and may have important neurotransmitter and neuromodulatory functions in the brain.