bluuebunny/crossref_metadata_2025 huggingface dataset:
Superinduction of c-
fos
by Nerve Growth Factor in the Presence of Peripherally Active Benzodiazepines
Authors: Curran Tom , Morgan James I.
Published: October 2006

Alterations in proto-oncogene expression after stimulation of rat pheochromocytoma (PC12) cells by nerve growth factor (NGF) have been investigated. A specific stimulation of c-
fos
messenger RNA and protein was detected 30 minutes after treatment. This induction was enhanced more than 100-fold in the presence of peripherally active benzodiazepines. The effect was specific as very little change was observed in the levels of c-
ras
Ha
, c-
ras
Ki
, c-
myc
, and N-
myc
messenger RNA's. Under the conditions used here, NGF treatment ultimately results in neurite outgrowth, with a reduction or cessation of cell division. Thus, stimulation of the c-
fos
gene in this system appeared to be associated with differentiation and not with cellular proliferation. The effect of benzodiazepines was stereospecific and represents a novel action of these compounds at the level of gene expression.
Glucocorticoids Potentiate Ischemic Injury to Neurons: Therapeutic Implications
Authors: Sapolsky Robert M. , Pulsinelli William A.
Published: October 2006

Sustained exposure to glucocorticoids, the adrenocortical stress hormones, is toxic to neurons, and such toxicity appears to play a role in neuron loss during aging. Previous work has shown that glucocorticoids compromise the capacity of neurons to survive a variety of metabolic insults. This report extends those observations by showing that ischemic injury to neurons in rat brain is also potentiated by exposure to high physiological titers of glucocorticoids and is attenuated by adrenalectomy. The synergy between ischemic and glucocorticoid brain injury was seen even when glucocorticoid levels were manipulated after the ischemic insult. Pharmacological interventions that diminish the adrenocortical stress response may improve neurological outcome from stroke or cardiac arrest.
Leukotrienes as Mediators in Tissue Trauma
Authors: Denzlinger C. , Rapp S. , Hagmann W. , Keppler D.
Published: October 2006

A significant increase in the production of cysteinyl leukotrienes was observed after mechanical or thermal trauma in the anesthesized rat. The amount of biliary
N
-acetyl-leukotriene E
4
, which represents a suitable indicator for blood plasma leukotrienes, was used as a measure of leukotriene generation. Cysteinyl leukotrienes were rapidly eliminated from blood plasma into bile where
N
-acetyl-leukotriene E
4
was the major metabolite. Leukotrienes were at a much lower concentration in blood plasma than in bile and differed in the pattern of metabolites. The detected amounts of leukotrienes were sufficient to induce known phenomena associated with trauma, such as tissue edema and circulatory and respiratory dysfunction. Increased leukotriene generation appears to play an important role in the pathophysiology of tissue trauma.
The Changing View of Neural Specificity
Authors: Easter S. S. , Purves D. , Rakic P. , Spitzer N. C.
Published: October 2006

The generation of specific patterns of neuronal connections has usually been regarded as a central problem in neurobiology. The prevailing view for many years has been that these connections are established by complementary recognition molecules on the pre- and postsynaptic cells (the chemoaffinity theory). Experimental results obtained in the past decade, however, indicate that the view that axon guidance and synaptogenesis proceed according to restrictive chemical markers is too narrow. Although a more rigid plan may prevail in some invertebrates, the formation of specific connections in vertebrates also involves competition between axon terminals, trophic feedback between pre- and postsynaptic cells, and modification of connections by functional activity.
Enzymatic Removal of Bilirubin From Blood: A Potential Treatment for Neonatal Jaundice
Authors: Lavin Arthur , Sung Cynthia , Klibanov Alexander M. , Langer Robert
Published: October 2006

Current treatments for severe jaundice can result in major complications. Neonatal jaundice is caused by excessive accumulation of bilirubin in the blood. A small blood filter containing immobilized bilirubin oxidase was developed to reduce serum bilirubin concentrations. When human or rat blood was passed through the enzyme filter, more than 90 percent of the bilirubin was degraded in a single pass. This procedure may have important applications in the clinical treatment of neonatal jaundice.
Isolation of a Mammalian Sequence Capable of Conferring Cell Cycle Regulation to a Heterologous Gene
Authors: Artishevsky Alexander , Grafsky Albert , Lee Amy Shiu
Published: October 2006

A hybrid gene containing the 5′ sequence of a hamster histone H3 gene and the coding sequence of the bacterial neomycin-resistance gene (
neo
) was constructed. Upon transfection into the hamster fibroblast cell line K12, the hybrid gene exhibited cell cycle-dependent regulation, as evidenced by the maximal accumulation of the
neo
transcripts during synthesis of DNA in the cell cycle. In addition, cells arrested in the prereplicative phase, as a consequence of the K12 temperature-sensitive mutation, produced significantly less
neo
messenger RNA.
Myofibrils Bear Most of the Resting Tension in Frog Skeletal Muscle
Authors: Magid Alan , Law Douglas J.
Published: October 2006

The tension that develops when relaxed muscles are stretched is the resting (or passive) tension. It has recently been shown that the resting tension of intact skeletal muscle fibers is equivalent to that of mechanically skinned skeletal muscle fibers. Laser diffraction measurements of sarcomere length have now been used to show that the exponential relation between resting tension and sarcomere length for whole frog semitendinosus muscle is similar to that of single fibers. Slack sarcomere lengths and the rates of stress relaxation in these muscles were similar to those in skinned fibers, and sarcomere length remained unchanged during stress relaxation, as in skinned fibers. Thus, in intact semitendinosus muscle of the frog up to a sarcomere length of about 3.8 micrometers, resting tension arises, not in the connective tissue as is commonly thought, but in the elastic resistance of the myofibrils.
Behavioral History as a Determinant of the Effects of
d
-Amphetamine on Punished Behavior
Authors: Barrett James E.
Published: October 2006

Food-maintained responding by four squirrel monkeys (
Saimiri sciureus
) was suppressed by the presentation of electric shock (punishment). Two of these monkeys were experimentally naive and two had a history of responding maintained by both shock-postponement and shock-presentation schedules. In accord with earlier studies, d-amphetamine did not increase punished responding by naive monkeys. However, it did increase punished responding in the others. Subsequently, d-amphetamine also increased punished responding by the initially naive monkeys after they were trained under a shock-postponement schedule. Even though not evident in current behavior, an organism's prior experience can influence the behavioral effects of drugs.
Covalent Immunoglobulin Assembly in Vitro: Reactivity of Light Chain Covalent Dimers (L
2
) and Blocked Light Chain Monomers
Authors: Kazin A. R. , Beychok S.
Published: October 2006

Covalent light chain dimers (L
2
) and cysteine-blocked L chain monomers readily react with partially reduced heavy (H) chains. A rapid disappearance of these blocked L chain species is followed by the appearance of covalent intermediates—HL, H
2
, and H
2
L—leading to fully assembled H
2
L
2
. The mechanism of initial disulfide bond formation between heavy and light chains is disulfide interchange.
Eye Movements of Monkeys During Learning-Set Formation
Authors: Schrier Allan M. , Povar Morris L.
Published: October 2006

Eye movements of stump-tailed monkeys were measured during learning of a long series of two-choice pattern discrimination problems. The amount of scanning per trial (shifts in visual fixation from one pattern to the other) and the duration of individual fixations on the patterns increased during the course of learning-set formation and (except for the amount of scanning by some animals) remained high during the prolonged training following learning-set formation. Some of the changes in eye movements were different from those seen during the learning of single discrimination problems, a difference that possibly reflects cognitive processes specific to the learning-set task.
On the Nature of Human Interlimb Coordination
Authors: Kelso J. A. Scott , Southard Dan L. , Goodman David
Published: October 2006

Movement time varies as a function of amplitude and requirements for precision, according to Fitts' law, but when subjects perform two-handed movements to targets of widely disparate difficulty they do so simultaneously. The hand moving to an "easy" target moves more slowly to accommodate its "difficult" counterpart, yet both hands reach peak velocity and acceleration synchronously. This result suggests that the brain produces simultaneity of action not by controlling each limb independently, but by organizing functional groupings of muscles that are constrained to act as a single unit.
Semliki Forest Virus: Cause of a Fatal Case of Human Encephalitis
Authors: Willems W. R. , Kaluza G. , Boschek C. B. , Bauer H. , Hager H. , Schütz H.-J. , Feistner H.
Published: October 2006

A fatal case of human encephalitis has been observed for which our results indicate that Semliki Forest virus (SFV) was the etiologic agent. This is surprising in view of the fact that this virus, which has been widely studied, was believed to be one of the arboviruses nonpathogenic for man. Described are the clinical course, the virological examinations performed, and the histopathological findings in the central nervous system.
Tight Junctions in a Fluid-Transporting Epithelium of an Insect
Authors: Lane Nancy J.
Published: October 2006

Occluding junctions have been found between the lateral cell borders at the base of the rectum of
Periplaneta americana
. They appear as punctate membrane appositions in thin sections, and after incubation in physiological solutions containing lanthanum before fixation the inward penetration of tracer is impeded in this same basal area. Moreover, freeze-fracture studies of this region reveal simple linear ridges on fracture face P and grooves on fracture face E, which are similar to the less complex vertebrate tight junctions. The luminal clefts, which permit free inward diffusion of tracers, present no tight junctions, but do have septate junctions. These results support the contention that, contrary to earlier speculation, arthropods do possess tight junctions; these, rather than septate junctions, appear to form the morphological basis of at least some of the permeability barriers observed in invertebrates.
Intraretinal Distribution of Cone Pigments in Certain Teleost Fishes
Authors: Levine J. S. , MacNichol E. F. , Kraft T. , Collins B. A.
Published: October 2006

Microspectrophotometric investigations of visual pigments in the teleost family Cichlidae determined that morphological "twin cones" need not be "pigment twins" as well. In each species there were two pigments that could be found in these cells; a "longwave" and a "shortwave" type whose precise spectral location varies for each species, making the terms red and green inadequate to describe them. Studies of the receptor mosaic with the nitro-blue tetrazolium chloride reduction technique permitted the sampling of larger receptor populations and confirmed that twin cones in several cichlid species could be either longwave-longwave, longwave-shortwave, or shortwave-shortwave pairs, and that the relative proportions of these twin cone types vary in different parts of the retinas. Nonuniform distribution of pigment types was also evident in the eyes of several other species from a variety of piscine taxa.
Conditioned Inhibition: Selective Response of Single Units
Authors: de Toledo-Morrell Leyla , Hoeppner Thomas J. , Morrell Frank
Published: October 2006

Single cell activity and local field potentials in parastriate cortex of cats and rabbits were studied during a Pavlovian discrimination procedure. Cell activity was selectively modified; conditioned changes occurred in response either to the reinforced stimulus or to the unreinforced one, but not to both. Cells exhibiting conditioned alteration in response to the unreinforced stimulus are thought to participate in specialized circuits mediating conditioned inhibition.
Hydroxylase Cofactor Activity in Cerebrospinal Fluid of Normal Subjects and Patients with Parkinson's Disease
Authors: Lovenberg W. , Levine R. A. , Robinson D. S. , Ebert M. , Williams A. C. , Calne D. B.
Published: October 2006

A method for measuring hydroxylase cofactor activity in human cerebrospinal fluid is described. The hydroxylase cofactor content of cerebrospinal fluid from Parkinsonian patients is approximately 50 percent that of normal subjects. A significant correlation between hydroxylase cofactor and the concentration of homovanillic acid in the cerebrospinal fluid was observed.
Immunocompetence in the Lowest Metazoan Phylum: Transplantation Immunity in Sponges
Authors: Hildemann William H. , Johnston Ian S. , Jokiel Paul L.
Published: October 2006

Isografts of
Callyspongia diffusa
fuse compatibly, but allografts are invariably incompatible. Extensive polymorphism of cell-surface histocompatibility markers is evident. The histocompatibility barriers range from strong to weak depending on the interclonal combination, but early rejection with conspicuous cytotoxic sequelae is typical. Reaction times of first-set, second-set, and third-party grafts indicate highly discriminating transplantation immunity with a specific memory component.
Binocularity in Kittens Reared with Optically Induced Squint
Authors: Smith Earl L. , Bennett Michael J. , Harwerth Ronald S. , Crawford M. L. J.
Published: October 2006

The effects of conflicting visual images were studied without the confounding influences of oculomotor abnormalities: strabismus was simulated by rearing kittens with ophthalmic prisms before the eyes. After the animals had matured, the response properties of neurons in the visual cortex were studied. The proportion of binocularly excited neurons decreased; however, the extent of the ocular dominance alterations was related to the amount and direction of the prism-induced deviation.
Non-A, Non-B Hepatitis: Ultrastructural Evidence for Two Agents in Experimentally Infected Chimpanzees
Authors: Shimizu Yohko K. , Feinstone Stephen M. , Purcell Robert H. , Alter Harvey J. , London William T.
Published: October 2006

Two different ultrastructural alterations were observed in liver cells of chimpanzees inoculated with plasma derived from two different patients with non-A, non-B hepatitis. During the acute phase of illness in one group of four chimpanzees, peculiar tubular structures, composed of two unit membranes with electron-opaque material in between, were observed in the cytoplasm of hepatocytes. In contrast, these structures were never detected in the liver cells of the second group of five chimpanzees that received the second inoculum, However, nuclear changes, usually associated with aggregates of 20- to 27-nanometer particles, were found in hepatocytes of the latter animals. Although these particles resembled viruses, they were not as uniform as small virus particles often appear. In five other chimpanzees inoculated with non-A, non-B hepatitis material not known to be related to the first two inocula, cytoplasmic structures were found in four, and nuclear structures were found in the remaining one. Thus, all 14 chimpanzees inoculated with transmissible non-A, non-B hepatitis agents could be classified as having either nuclear or cytoplasmic changes. These observations add support to epidemiologic data suggesting that there may be more than one agent of non-A, non-B hepatitis.
Transmitter-Specific Retrograde Labeling in the Striato-Nigral and Raphe-Nigral Pathways
Authors: Streit Peter , Knecht Eva , Cuénod Michel
Published: October 2006

Injecting radioactive transmitters into the rat substantia nigra led to retrograde neuronal labeling either in the dorsal raphe nucleus, after
3
H-labeled serotonin injection, or in the caudoputamen, after
3
H-labeled γ-aminobutyric acid injection. This differential labeling in projections whose transmitter has been established provides the basis for a histochemical tracing method indicating both connectivity and transmitter specificity of neural pathways.
Hybrid Ape Offspring of a Mating of Gibbon and Siamang
Authors: Myers Richard H. , Shafer David A.
Published: October 2006

The serendipitous mating of a male gibbon,
Hylobates moloch
, and a female siamang,
Symphalangus syndactylus
, has produced two female offspring born 1 year apart. The hybrid karyotype of 47 chromosomes comprises the haploid complements of the parental species, 22 for the gibbon and 25 for the siamang. Chromosomal G and C banding comparisons revealed no clear homologies between the parental karyotypes except for the single chromosome in each species containing the nucleolus organizer region. The lack of homology suggests that the structural rearrangement of chromosomes has played a major role in the process of speciation for these lesser apes.
Opioid Peptides May Excite Hippocampal Pyramidal Neurons by Inhibiting Adjacent Inhibitory Interneurons
Authors: Zieglgänsberger W. , French E. D. , Siggins G. R. , Bloom F. E.
Published: October 2006

The atypical excitation by opiates and opioid peptides of hippocampal pyramidal cells can be antagonized by iontophoresis of naloxone, the γ-aminobutyric acid antagonist bicuculline, or magnesium ion. The recurrent inhibition of these cells evoked by transcallosal stimulation of the contralateral hippocampus is blocked by enkephalin but only shortened by acetylcholine. The results suggest that the opioids excite pyramidal neurons indirectly by inhibition of neighboring inhibitory interneurons (probably containing γ-aminobutyric acid). This mechanism may be pertinent to the electrographic signs of addictive drugs.
Thyroid Hormone Influence on the Susceptibility of Mice to Audiogenic Seizures
Authors: Seyfried Thomas N. , Glaser Gilbert H. , Yu Robert K.
Published: October 2006

Serum thyroxine levels peak earlier and are significantly higher in audiogenic seizure-susceptible DBA/2J mice than in seizure-resistant C57BL/6J mice during early postnatal life. The seizure susceptibility of DBA/2J mice is suppressed by administration of an antithyroid drug or by radiothyroidectomy, while the seizure susceptibility of C57BL/6J mice is enhanced by treatment with excess thyroxine.
Synaptic Proteins After Electroconvulsive Stimulation
Authors: Jørgensen Ole Steen , Bolwig Tom G.
Published: October 2006

Quantitative immunoelectrophoresis of rat brain synaptic proteins following a series of electroconvulsive stimulations demonstrated changes suggestive of an increase in the number of synaptic vesicles, in a preparedness for glycolytic demands, and a delayed development of a certain area in the brain. The increased synaptic remodeling may be important for the action of electroconvulsive therapy.
Metabolic Mapping of Functional Activity in the Hypothalamo-Neurohypophysial System of the Rat
Authors: Schwartz William J. , Smith Carolyn B. , Davidsen Leslie , Savaki Helen , Sokoloff Louis , Mata Marina , Fink David J. , Gainer Harold
Published: October 2006

Physiological stimulation of the hypothalamo-neurohypophysial system by salt loading of rats resulted in a dramatically increased glucose utilization in the posterior pituitary but not in the paraventricular or supraoptic nuclei. The good correlation between glucose utilization and neural activity in the posterior pituitary (that is, nerve terminals) contrasted with the lack of correlation in the paraventricular and supraoptic nuclei (that is, the sites of the cell bodies of the same neurons). This difference in the metabolic response to functional activity between the two regions of these neurons can be explained by the differences in surface-to-volume ratios of these regions.
Assessment of Diagnostic Technologies
Authors: Swets John A. , Pickett Ronald M. , Whitehead Susan F. , Getty David J. , Schnur James A. , Swets Joel B. , Freeman Barbara A.
Published: October 2006

A general protocol for rigorous evaluation of diagnostic systems in medicine was applied successfully in a comparative study of two radiologic techniques. Accuracies of computed tomography and radionuclide scanning in detecting, localizing, and diagnosing brain lesions were assessed with a sample of patients in whom tumor had been suspected. The principal means of analysis was the "relative operating characteristic," which is unique in providing a measure of accuracy that is largely independent of decision biases. Computed tomography was found to be substantially more accurate than radionuclide scanning.
Partial Amino Acid Sequence of Rabbit β
2
-Microglobulin
Authors: Cunningham Bruce A. , Berggård Ingemar
Published: October 2006

The amino acid sequence of the first 35 residues of a low-molecular-weight protein obtained from the urine of rabbits treated with sodium dichromate was determined and shown to be identical with human β
2
-microglobulin in 30 positions. Rabbit β
2
-microglobulin, like the human protein, is strikingly homologous to the constant regions of rabbit immunoglobulin G, particularly the C
H
3 region.
Batrachotoxin Block of Fast Axoplasmic Transport in Mammalian Nerve Fibers
Authors: Ochs Sidney , Worth Robert
Published: October 2006

Batrachotoxin (BTX) irreversibly blocks fast axoplasmic transport in nerve in concentrations as low as 0.2 micromolar. The action of BTX was studied in cat sciatic nerves in vitro by measuring the rate of the crest outflow after injection of the L7 dorsal root ganglion with [
3
H]leucine. Tetrodotoxin, which in itself does not affect fast axoplasmic transport, inhibited the blocking action of BTX. Unlike the BTX block of nerve and muscle membrane excitability brought about through increased permeability to sodium ion, the BTX block of fast axoplasmic transport occurs with or without sodium ion in the medium. High concentrations of calcium ion protected against the blocking action of BTX, while magnesium ion did not. An action of BTX on the transport mechanism inside the fibers was indicated by the small reduction of adenosine triphosphate plus creatine phosphate, which in itself did not account for the block of axoplasmic transport.
p-Chloroamphetamine: Selective Neurotoxic Action in Brain
Authors: Harvey John A. , McMaster Scott E. , Yunger Libby M.
Published: October 2006

Injection of 2.5, 5, 10, or 20 milligrams ofp-chloroamphetamine per kilogram of body weight into rats produced evidence of cytopathological changes in sections of brain stained by a Nissl or silver method. As early as 1 day after drug injection cells demonstrated an intense Nissl staining, intense argyrophilia, cellular shrinkage, and perineuronal spaces. At 30 days after injection both stains revealed cellular debris and glial reactions characteristic of cellular dissolution. The neurotoxic effects of 2.5, 5, or 10 milligrams ofp-chloroamphetamine per kilogram were primarily restricted to an area of the ventral midbrain tegmentum corresponding to the distribution of the B-9 serotonergic cell group. After 20 milligrams ofp-chloroamphetamine per kilogram there was also evidence of neurotoxic effects on cells within the substantia nigra. These results confirm previous suggestions that the long-term reduction in serotonin content of brain, tryptophan-5-hydroxylase activity, and uptake of serotonin after injection ofp-chloroamphetamine is due to a neurotoxic effect of the drug or some metabolite on serotonergic cell bodies.
Visual Resolution and Receptive Field Size: Examination of Two Kinds of Cat Retinal Ganglion Cell
Authors: Cleland B. G. , Harding T. H. , Tulunay-Keesey U.
Published: October 2006

Intraocular recordings from brisk-sustained and brisk-transient ganglion cells in the cat's retina revealed a systematic increase in center size and decrease in spatial cut-off frequency with increasing distance from the area centralis. At any one eccentricity sizes of the centers of sustained and transient cells did not overlap, and the variation in cut-off frequency for each class was constrained to about one-half octave.
Pigeons Have Magnets
Authors: Walcott Charles , Gould James L. , Kirschvink J. L.
Published: October 2006

Research on pigeon homing suggests that magnetic field information is used for orientation. The ability of pigeons to sense magnetic fields may be associated with a small, unilateral structure between the brain and the skull which contains magnetite in what appears to be single domains.
Sister Chromatid Exchanges in Human Lymphocytes After Exposure to Diagnostic Ultrasound
Authors: Liebeskind Doreen , Bases Robert , Mendez Frances , Elequin Flora , Koenigsberg Mordecai
Published: October 2006

The frequency of sister chromatid exchanges increased in freshly isolated human lymphocytes as well as in a continuously growing lymphoblast line by exposure to diagnostic levels of ultrasound for 30 minutes. The results confirm previous findings indicating that ultrasound of diagnostic intensities can affect the DNA of animal cells.
Developmental Fate of Skeletal Muscle Satellite Cells
Authors: Lipton Bruce H. , Schultz Edward
Published: October 2006

Radioisotopically labeled satellite cells from clonal cultures were implanted into normal muscle of the original donor. Implanted cells invariably retained their myogenic potential by participating in the regeneration of damaged myofibers or in the development of existing fibers.
Serotonin Neurons Project to Small Blood Vessels in the Brain
Authors: Reinhard John F. , Liebmann James E. , Schlosberg Arthur J. , Moskowitz Michael A.
Published: October 2006

Electrolytic lesions of the nucleus raphe dorsalis and medianus reduce the concentration of serotonin (5-hydroxytryptamine) within rat brain intraparenchymal blood vessels. The concentration of serotonin within these vessels increases or decreases after the administration of drugs that modify the biosynthesis and degradation of serotonin or destroy nerve terminals by an uptake-dependent mechanism. These studies provide evidence for the existence of a serotonin-containing pathway seemingly analogous to the neuronal projection that terminates on small parenchymal blood vessels from noradrenergic neurons of the locus coeruleus.
Comparison of Total Sequence of a Cloned Rabbit β-Globin Gene and Its Flanking Regions with a Homologous Mouse Sequence
Authors: van Ooyen A. , van den Berg J. , Mantei N. , Weissmann C.
Published: October 2006

The nucleotide sequence of a cloned rabbit chromosomal DNA segment of 1620 nucleotides length which contains a β-globin gene is presented. The coding regions are separated into three blocks by two intervening sequences of 126 and 573 base pairs, respectively. The rabbit sequence was compared with a homologous mouse sequence. The segments flanking the rabbit gene, as well as the coding regions, the 5′ noncoding and part of the 3′ noncoding messenger RNA sequences are similar to those of the mouse gene; the homologous introns, despite identical location, are distinctly dissimilar except for the junction regions. Homologous introns may be derived from common ancestral introns by large insertions and deletions rather than by multiple point mutations.
Intestinal Absorption of Immune Complexes by Neonatal Rats: A Route of Antigen Transfer from Mother to Young
Authors: Abrahamson Dale R. , Powers Alvin , Rodewald Richard
Published: October 2006

Horseradish peroxidase (HRP) in the presence of specific immunoglobulin G antibody to HRP is selectively absorbed from the gut lumen and transferred by intestinal epithelial cells to the lamina propria in newborn rats. The HRP is not transferred in detectable amounts in the absence of the antibody. Transport of maternally derived antigen via antigen-antibody complexes may have important influences on the developing immune system in young mammals.
Endothermy and Activity in Vertebrates
Authors: Bennett Albert F. , Ruben John A.
Published: October 2006

Resting and maximal levels of oxygen consumption of endothermic vertebrates exceed those of ectotherms by an average of five- to tenfold. Endotherms have a much broader range of activity that can be sustained by this augmented aerobic metabolism. Ectotherms are more reliant upon, and limited by, anaerobic metabolism during activity. A principal factor in the evolution of endothermy was the increase in aerobic capacities to support sustained activity.
Activation of the Supplementary Motor Area During Voluntary Movement in Man Suggests It Works as a Supramotor Area
Authors: Orgogozo J. M. , Larsen B.
Published: October 2006

Measurements of cerebral blood flow in man revealed that complex voluntary movements are associated with a blood flow increase in the supplementary motor area of the brain. This increase is additional to and similar in magnitude to the Rolandic sensorimotor area activation that occurs during all kinds of movement. When subjects counted silently there was no activation of any focal cortical area in the brain; when they counted aloud there was a marked increase in activity in the supplementary motor area. These results are consistent with the hypothesis that the supplementary motor area plays a major role in the initiation and control of at least some kinds of voluntary movement in man and is, therefore, a motor center of a higher order than the primary Rolandic areas.
Reading Without a Fovea
Authors: Rayner Keith , Bertera James H.
Published: October 2006

A visual mask moving in synchrony with the eye obliterated foveal vision during reading under certain conditions. When foveal vision was masked, reading became difficult. In another condition, a window of readable text moved in synchrony with the eye, and parafoveal vision was masked on each fixation. The results point out the importance of foveal and parafoveal vision in reading.
Stimulation of Abducens Nucleus Supports Classical Conditioning of the Nictitating Membrane Response
Authors: Mis Frederick W. , Gormezano I. , Harvey John A.
Published: October 2006

The acquisition and terminal performance of a classical conditioning group compared with a control group indicated that extension of the nictitating membrane elicited by direct electrical stimulation of the abducens nucleus was successfully conditioned to a previously neutral stimulus. The conditioning so obtained was associative and not due to such nonassociative factors as sensitization, pseudoconditioning, or alteration in base-rate responding.
A Correlation Between Platelet Monoamine Oxidase Activity and Plasma Prolactin Concentrations in Man
Authors: Kleinman Joel E. , Potkin Steven , Rogol Alan , Buchsbaum Monte S. , Murphy Dennis L. , Gillin J. Christian , Nasrallah Henry A. , Wyatt Richard Jed
Published: October 2006

Increases in plasma prolactin concentrations produced by α-methyl-
p
-tyrosine, a catecholamine synthesis inhibitor, varied inversely with baseline platelet monoamine oxidase activity in 12 patients with chronic schizophrenia. In normal volunteers with low monoamine oxidase activity and in unmedicated patients with chronic schizophrenia, plasma prolactin concentrations varied directly with platelet monoamine oxidase activity. No such relationship was found in normal subjects with high platelet monoamine oxidase activity. These data suggest that platelet monoamine oxidase activity reflects monoaminergic activity in the tubero-infundibular system, which in turn affects plasma prolactin concentrations. This relationship may be important in patients with low platelet monoamine oxidase activity, such as some chronic schizophrenics.
A Glucose-Controlled Insulin-Delivery System: Semisynthetic Insulin Bound to Lectin
Authors: Brownlee Michael , Cerami Anthony
Published: October 2006

A stable, biologically active glycosylated insulin derivative that is complementary to the major combining site of concanavalin A has been synthesized. Hormone release is proportional to the quantity of glucose present. Glucose regulation of exogenous insulin delivery could have important applications in the therapy of diabetes mellitus.
Perception of Size of One Object Among Many
Authors: Levinson John Z. , Frome Francine S.
Published: October 2006

Adaptation to a grating of properly chosen frequency may lead to two apparently conflicting observations: Another grating may then appear to be of increased frequency (compared with its "unadapted" frequency) while the individual bars of the grating appear to have widened. This perceived widening parallels previous results with single bars. By attending to only one grating bar, the subject effectively seems to change the grating frequency spectrum to that of a single bar.
Sustained Release of Alcohol: Subcutaneous Silastic Implants in Mice
Authors: Erickson Carlton K. , Koch Kathe I. , Mehta Chander S. , McGinity James W.
Published: October 2006

A sustained-release device for use in ethanol dependence studies in mice is described. The Silastic device, dubbed SERT (sustained ethanol release tube), holds 0.35 milliliter of 95 percent ethanol (by volume) and is implanted under the skin of the back where it releases ethanol for up to 12 hours, with no observable tissue damage. The device may be adaptable to the release of other volatile liquids or drugs, in other animals.
Neuroleptic-Induced "Anhedonia" in Rats: Pimozide Blocks Reward Quality of Food
Authors: Wise Roy A. , Spindler Joan , deWit Harriet , Gerberg Gary J.
Published: October 2006

The dopamine receptor blocker pimozide attenuated lever-pressing and running for food reward in hungry rats. In each case the characteristic behavior of pimozide-treated rats was the same as that of undrugged rats when reward was simply withheld. Drug-induced performance difficulties were ruled out by the presence of periods of normal responding in drug-treated animals. Pimozide appears to selectively blunt the rewarding impact of food and other hedonic stimuli.
Early Maternal Separation Increases Gastric Ulcer Risk in Rats by Producing a Latent Thermoregulatory Disturbance
Authors: Ackerman Sigurd H. , Hofer Myron A. , Weiner Herbert
Published: October 2006

Rat pups that are separated early from their mothers, at postnatal day 15, become hypothermic when subjected to physical restraint on postnatal day 30. Restraint of separated pups also elicits an unusually high incidence of gastric erosions, as well as insomnia and an increase in quiet wakefulness. If hypothermia during restraint is prevented, neither the erosions nor the behavioral responses occur. Rat pups separated at the customary age (postnatal day 22) do not become hypothermic during restraint, and the restraint of such pups is not associated with either gastric erosion or insomnia.
Morphological Alterations in Hippocampus After Long-Term Alcohol Consumption in Mice
Authors: Riley Joseph N. , Walker Don W.
Published: October 2006

Golgi methods were used to examine the hippocampus of laboratory mice that received alcohol-containing or control diets for 4 months followed by a 2-month alcohol-free period. Long-term alcohol consumption resulted in a significant loss of dendritic spines on hippocampal pyramidal cells and dentate granule cells. This study provides evidence that long-term alcohol consumption, in the absence of malnutrition, produces morphological damage to the central nervous system.
Phenylalanine Depletion for the Management of Phenylketonuria: Use of Enzyme Reactors with Immobilized Enzymes
Authors: Ambrus Clara M. , Ambrus Julian L. , Horvath Csaba , Pedersen Henrik , Sharma Satya , Kant Christopher , Mirand Edwin , Guthrie Robert , Paul Thomas
Published: October 2006

Multitubular enzyme reactors with immobilized phenylalanine ammonia lyase were tested in vitro and in vivo for depletion of phenylalanine in circulating blood. Sustained reduction of phenylalanine was achieved in less than 30 minutes. A 50 percent decrease of phenylalanine was obtained with a 2-hour application of enzyme reactors and was maintained for more than 2 days. Similar enzyme reactors have therapeutic potential for temporary management of phenylketonuric patients when their circulating phenylalanine becomes exceedingly high because of infection, fever, or pregnancy.
Circadian Clock in Culture:
N
-Acetyltransferase Activity of Chick Pineal Glands Oscillates in Vitro
Authors: Kasal Charles A. , Menaker Michael , Perez-Polo J. Regino
Published: October 2006

N
-Acetyltransferase activity was measured in organ-cultured chick pineal glands. A circadian rhythm of enzyme activity persisted in cultured glands for up to 4 days. The phase of the rhythm in vitro closely approximates its phase in vivo. These observations demonstrate that the pineal gland of chicks contains (or is) a self-sustained circadian oscillator.
Retrograde Amnesia for Old (Reactivated) Memory: Some Anomalous Characteristics
Authors: Mactutus Charles F. , Riccio David C. , Ferek Jacquelyn M.
Published: October 2006

Old memory, when reactivated by cue exposure, was disrupted by mild or deep hypothermia treatments. New memory was impaired only by deep cooling. Moreover, old but not new learning showed spontaneous recovery. Old reactivated memory may be qualitatively different from newly acquired memory.
Placental Localization of Human Pregnancy—Associated Plasma Proteins
Authors: Lin Tsue-Ming , Halbert Seymour P.
Published: October 2006

Frozen sections of human placenta were examined for the presence of four human pregnancy proteins, pregnancy-associated plasma proteins A and C (PAPP-A and PAPP-C), human chorionic somatomammotropin (hCS), and pregnancy zone protein (PZP), by the indirect immunofluorescence technique. Monospecific rabbit antiserums to PAPP-A, PAPP-C, and hCS all stained the trophoblast cytoplasm equivalently in a continuous layer, suggesting that the same trophoblast cells synthesize all three pregnancy proteins. In contrast, PZP was localized in blood vessel walls, parenchymal structures within the villous, as well as in the trophoblast cytoplasm. Its distribution in the latter was relatively inhomogeneous, tending to be more intense on the basement membrane side.
Small DNA Deletions Creating Avirulence in
Streptococcus pyogenes
Authors: Spanier Jonathan G. , Jones S. J. C. , Cleary Patrick
Published: October 2006

The M protein is the antigen on the surface of group A streptococci that allows these bacteria to resist phagocytosis. DNA encoding the M12 protein was cloned into
Escherichia coli
and used as an isotopically labeled hybridization probe to compare genomic DNA's isolated from M
+
and M
-
isogenic cultures in an effort to elucidate the genetic basis of this variation. DNA's from two spontaneous, independent M
-
variants contained small (approximately 50 base pairs) deletions which were mapped to identical restriction fragments within or adjacent to the M protein coding sequence. Taken together with the pleiotropic nature of these deletions, this suggests that they define a regulatory switch.
Expression of the 3′ Terminal Region of Human T-Cell Leukemia Viruses
Authors: Wachsman William , Shimotohno Kunitada , Clark Steven C. , Golde David W. , Chen Irvin S. Y.
Published: October 2006

Human T-cell leukemia viruses (HTLV) are closely associated with some human T-cell leukemias and lymphomas. A unique 3′ region of the HTLV genome is believed to be involved in HTLV-induced cellular transformation, although the function of this region has yet to be determined. A subgenomic messenger RNA transcribed from this region of HTLV has now been characterized. These results provide direct evidence for the expression of a novel gene in HTLV.
A Simple Membrane Manometer
Authors: Hirschfelder Arthur D. , Gregory Raymond L.
Published: October 2006

The abdominal aorta of small mammals is easy of access, and this vessel is well suited for the taking of blood pressure tracings having a good amplitude of pulsation.

The construction of a very simply made and satisfactory membrane manometer is described with which tracings of very large pulse amplitude are easily obtained.
γ-Glutamyl Transpeptidase in Isolated Brain Endothelial Cells: Induction by Glial Cells in Vitro
Authors: DeBault Lawrence E. , Cancilla Pasquale A.
Published: October 2006

The endothelia of microvessels isolated from mouse brain by mechanical means are rich in γ-glutamyl transpeptidase; however, the enzyme often disappears when the cells migrate or proliferate from the microvessel isolates. In an endothelial cell line derived from similar isolates and negative for γ-glutamyl transpeptidase, the enzyme could be induced in the endothelial cells when they were cocultured with glial cells. Thus there may be a requirement for continuous induction of γ-glutamyl transpeptidase in brain microvessels by adjacent glial cells.
Purinergic Receptors: Photoaffinity Analog of Adenosine Triphosphate Is a Specific Adenosine Triphosphate Antagonist
Authors: Hogaboom G. Kurt , O'Donnell John P. , Fedan Jeffrey S.
Published: October 2006

Arylazido aminopropionyl adenosine triphosphate (ANAPP3), a photoaffinity label, antagonized specifically adenine nucleotide-induced contractions of the guinea pig vas deferens. Irradiation of tissues with visible light in the presence of ANAPP3resulted in an irreversible antagonism, which was prevented when adenosine triphosphate was present. In the absence of light, the antagonism was reversible and may have resulted from an autoinhibition phenomenon. Responses to acetylcholine, histamine, norepinephrine, and potassium chloride were not affected by ANAPP3.
Pentapeptide (Proctolin) Associated with an Identified Neuron
Authors: O'Shea Michael , Adams Michael E.
Published: October 2006

Individual neurons can be recognized and identified anatomically, physiologically, and biochemically in the insect central nervous system. Biochemical analyses of extracts prepared from one such identified neuron show it to be associated with a bioactive pentapeptide called proctolin. This peptide may be a neurotransmitter, and a preparation is established in which its physiological action can be studied at the cellular level.
Electroconvulsive Shock Increases Tyrosine Hydroxylase Activity in the Brain and Adrenal Gland of the Rat
Authors: Masserano Joseph M. , Takimoto Glenn S. , Weiner Norman
Published: October 2006

A single application of electroconvulsive shock produced a rapid but short-lasting increase in tyrosine hydroxylase activity above control values in the rat adrenal medulla and striatum. After repeated electroconvulsive shock treatment (once per day for 7 days), tyrosine hydroxylase activity increased significantly in the locus ceruleus, nucleus of the tractus solitarius, hippocampus, cerebellum, and frontal cortex and remained elevated for 4 to 8 days. Adrenal tyrosine hydroxylase activity increased 1 day after the termination of repeated electroconvulsive shock treatments and remained elevated for at least 24 days, possibly reflecting the establishment of a new and higher steady-state level of catecholamine biosynthesis in the adrenal. These findings suggest that the persistent changes in tyrosine hydroxylase activity produced by repeated electroconvulsive shock may be a factor contributing to the long-lasting antidepressant effects of this treatment.
Prostaglandins Mediate Inhibition of Gastric Acid Secretion by Somatostatin in the Rat
Authors: Ligumsky Moshe , Goto Yoshiaki , Debas Haile , Yamada Tadataka
Published: October 2006

Somatostatin, a tetradecapeptide with potent inhibitory actions on gastric acid secretion, potentiated carbamylcholine-induced synthesis and release of prostaglandin E
2
from isolated perfused rat stomachs. The ability of somatostatin to inhibit acid secretion was blocked by indomethacin, an inhibitor of prostaglandin synthesis. These results suggest that prostaglandins mediate gastric acid inhibition by somatostatin in the rat.
Differential Effects of Classical and Atypical Antipsychotic Drugs on A9 and A10 Dopamine Neurons
Authors: White Francis J. , Wang Rex Y.
Published: October 2006

Prolonged treatment with classical antipsychotic drugs decreased the number of spontaneously active dopamine neurons in both the substantia nigra (A9) and the ventral tegmental area (A10) of the rat brain. In contrast, treatment with atypical antipsychotic drugs selectively decreased the number of A10 dopamine neurons. Related drugs lacking antipsychotic efficacy failed to decrease dopamine activity. These findings suggest that the inability of atypical antipsychotic drugs to decrease A9 dopamine neuronal activity may be related to their lower potential for causing tardive dyskinesia and that the inactivation of A10 neurons may be involved in the delayed onset of therapeutic effects during treatment.
Which Behavior Does the Lamprey Central Motor Program Mediate?
Authors: Ayers Joseph , Carpenter Gail A. , Currie Scott , Kinch James
Published: October 2006

The isolated lamprey spinal cord, when bathed in 2 millimolar D-glutamic acid, will generate a pattern of motor neuron discharge that has generally been assumed to represent the central motor program for swimming. Motion pictures of behaving lampreys were analyzed by a computer algorithm to estimate undulatory movement parameters that could be directly compared with those generated during D-glutamate--induced undulations. The D-glutamate-induced movement parameters were significantly different from those observed during normal behaviors, including swimming, but accurately predicted the undulations produced by spinally transected adult lampreys.
Sequence of the Human Somatostatin I Gene
Authors: Shen Lu-Ping , Rutter William J.
Published: October 2006

Two human genomic DNA fragments containing alleles for the gene coding for somatostatin I were isolated and sequenced. This gene contains a single intron that interrupts the coding sequence in the propeptide portion of the somatostatin moiety. The site of initiation of transcription of the gene was located by transcription experiments in HeLa cell extracts, and the putative regions for controlling the initiation of transcription were identified.
Strain Dependence of the Antiproliferative Action of Interferon on Murine Erythroid Precursors
Authors: Gallien-Lartigue Odette , Carrez Danièle , De Maeyer Edward , De Maeyer-Guignard Jaqueline
Published: October 2006

Electrophoretically pure mouse interferon inhibits erythropoietin-dependent proliferation of committed erythroid precursors (CFU-E) obtained either from adult mouse bone marrow or from 14-day fetal mouse livers. The degree of inhibition is significantly influenced by the genotype of the cell donor; about ten times as much interferon is required to inhibit proliferation of CFU-E from C57BL/6 than is needed for comparable inhibition of CFU-E from BALB/c or Swiss mice. These strain-dependent results point to the existence of genes that influence the degree of the inhibitory effect of interferon on cell multiplication.
Prostaglandin A Compounds as Antiviral Agents
Authors: Santoro M. G. , Benedetto A. , Carruba G. , Garaci E. , Jaffe B. M.
Published: October 2006

Prostaglandins of the A series strongly inhibit the production of Sendai virus in African green monkey kidney cells and are able to prevent the establishment of persistent infection ("carrier" state). This action is specific for prostaglandin A and is not due to alteration in the host cell metabolism or in the virus infectivity. The possibility that this effect is mediated by interferon is discussed.
A Technique for Expressing Eukaryotic Genes in Bacteria
Authors: Guarente Leonard , Roberts Thomas M. , Ptashne Mark
Published: October 2006

Methods are described that allow efficient expression in
Escherichia coli
of cloned eukaryotic genes. The methods require that the coding sequence of the gene in question be available in a form uninterrupted by intervening sequences (for example, as a complementary DNA clone). The gene products are synthesized unfused to other amino acid sequences. The genetic manipulations are simple, and require the plasmids described and commercially available enzymes.