bluuebunny/crossref_metadata_2025 huggingface dataset:
Human T-Cell Receptor α-Chain Genes: Location on Chromosome 14
Authors: Jones Carol , Morse Helvise G. , Kao Fa-Ten , Carbone Amy , Palmer Edward
Published: October 2006

The genes encoding the α chain of the human T-cell receptor have been mapped to chromosome 14, the chromosome on which the human immunoglobulin heavy chain locus resides. Thus, genes encoding two different classes of antigen receptor are present on the same chromosome. Furthermore, breaks involving chromosome 14 are frequently seen in tumors of T-cell origin. The potential relation of these chromosome abnormalities to α-chain genes is discussed.
Mutation to Herbicide Resistance Maps Within the
psbA
Gene of
Anacystis nidulans
R2
Authors: Golden Susan S. , Haselkorn Robert
Published: October 2006

A
psbA
gene encoding the target of photosystem II herbicide inhibition, the 32,000-dalton thylakoid membrane protein, has been cloned from a mutant of
Anacystis nidulans
R2, which is resistant to 3-(3,4-dichlorophenyl)-1,1-dimethylurea-(diuron). A cloned DNA fragment from within the coding region of this gene transforms wild-type cells to herbicide resistance, proving that mutation within
psbA
is responsible for that phenotype. The mutation consists of a single nucleotide change that replaces serine at position 264 of the wild-type protein with alanine in that of the diuron-resistant mutant.
The t(14;18) Chromosome Translocations Involved in B-Cell Neoplasms Result from Mistakes in VDJ Joining
Authors: Tsujimoto Yoshihide , Gorham James , Cossman Jeffrey , Jaffe Elaine , Croce Carlo M.
Published: October 2006

In this study, the joining sequences between chromosomes 14 and 18 on the 14q
+
chromosomes of a patient with pre-B-cell leukemia and four patients with follicular lymphoma carrying a t(14;18) chromosome translocation were analyzed. In each case, the involved segment of chromosome 18 has recombined with the immunoglobulin heavy-chain joining segment (J
H
) on chromosome 14. The sites of the recombination on chromosome 14 are located close to the 5′ end of the involved J
H
segment, where the diversity (D) regions are rearranged with the J
H
segments in the production of active heavy-chain genes. As extraneous nucleotides (N regions) were observed at joining sites and specific signal-like sequences were detected on chromosome 18 in close proximity to the breakpoints, it is concluded that the t(14;18) chromosome translocation is the result of a mistake during the process of VDJ joining at the pre-B-cell stage of differentiation. The putative recombinase joins separated DNA segments on two different chromosomes instead of joining separated segments on the same chromosome, causing a t(14;18) chromosome translocation in the involved B cells.
Partial Inversion of the Initiation-Promotion Sequence of Multistage Tumorigenesis in the Skin of NMRI Mice
Authors: Fürstenberger Gerhard , Kinzel Volker , Schwarz Michael , Marks Friedrich
Published: October 2006

Alterations in NMRI mouse skin induced by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate in "stage I of tumor promotion" are slowly reversible, and this reversibility has a half-time of 10 to 12 weeks. The tumor response observed in the course of an initiation-promotion experiment in vivo is independent of whether stage I of promotion occurs before or after initiation. Since the time interval between treatment with the promoter, and subsequent initiation can be extended up to at least 6 weeks, an enhancement of initiation because of promoter-induced cellular DNA synthesis seems to be unlikely. This result may be inconsistent with the two-stage model of tumor promotion because it indicates that in skin the existence of initiated cells is not required for the induction of cellular alterations that are essential for the stage of skin tumorigenesis called stage I of promotion.
Retinal Dystrophy: Development Retarded by Galactose Feeding in Spontaneously Hypertensive Rats
Authors: Frank Robert N. , Keirn Richard J. , Keirn Gail V. , Mancini Michael A. , Khoury Janet K.
Published: October 2006

Retinal photoreceptor cell dystrophies have been widely observed in humans and in animals, but pathogenetic mechanisms are known in only a few such disorders, and successful therapeutic intervention has been reported in fewer still. Spontaneously hypertensive albino rats develop a retinal photoreceptor cell dystrophy with onset late in the first year or early in the second year of life. Between 60 and 70 percent of the animals are affected. A substantial reduction in the prevalence and severity of the dystrophy occurred in such animals whose diet contained 30 percent (by weight) D-galactose. Neither an inhibitor of the enzyme aldose reductase, present in the diet, nor diabetes mellitus, induced by streptozotocin, had any statistically significant influence on the dystrophy. Ambient light and systolic blood pressure levels also did not seem to influence the course of the disorder. The mechanism by which galactose exerts its effect is unknown, but a mutant enzyme with an elevated Michaelis constant (
K
m
) for galactose is plausible.
Male-Killing Bacteria in a Parasitic Wasp
Authors: Werren John H. , Skinner S. W. , Huger A. M.
Published: October 2006

A rod-shaped bacterium has been isolated that kills male eggs of the wasp
Nasonia vitripennis
, a pupal parasite of flies. Only some wasps of this species express this son-killer trait, and these wasps have bacterial infections in various organs. The bacterium was isolated from son-killer wasp tissue and from the hemolymph of fly pupae parasitized by wasps expressing the son-killer trait. Bacteria are apparently transferred to parasitized fly pupae during wasp oviposition, and developing wasp offspring are subsequently infected perorally. Sex-ratio distortion by microorganisms is found in a variety of plants and animals. The infectious peroral transmission of this trait is in contrast to the typical pattern of cytoplasmic inheritance of sex-ratio distortion in these other systems.
Parvalbumin in Most γ-Aminobutyric Acid-Containing Neurons of the Rat Cerebral Cortex
Authors: Celio Marco R.
Published: October 2006

γ-Aminobutyric acid (GABA) is one of the major inhibitory neurotransmitters in the central nervous system. In the cerebral cortex, GABA-containing cells represent a subpopulation of interneurons. With semithin frozen sections, it is possible to demonstrate that most GABA neurons in the rat somatosensory cortex contain the calcium-binding protein parvalbumin and that parvalbumin is found virtually only in GABA neurons. Parvalbumin seems to influence the electrical properties and enzymatic machinery to modulate neuronal excitability and activity. The specific role of parvalbumin in GABA-containing cortical cells may be related to controlling the effectiveness of their inhibitory action.
Heterogeneous Nuclear Ribonucleoproteins: Role in RNA Splicing
Authors: Choi Yang Do , Grabowski Paula J. , Sharp Phillip A. , Dreyfuss Gideon
Published: October 2006

Splicing in vitro of a messenger RNA (mRNA) precursor (pre-mRNA) is inhibited by a monoclonal antibody to the C proteins (anti-C) of the heterogeneous nuclear RNA (hnRNA)-ribonucleoprotein (hnRNP) particles. This antibody, 4F4, inhibits an early step of the reaction: cleavage at the 3′ end of the upstream exon and the formation of the intron lariat. In contrast, boiled 4F4, or a different monoclonal antibody (designated 2B12) to the C proteins, or antibodies to other hnRNP proteins (120 and 68 kilodaltons) and nonimmune mouse antibodies have no inhibitory effect. The 4F4 antibody does not prevent the adenosine triphosphate-dependent formation of a 60
S
splicing complex (spliceosome). Furthermore, the 60
S
splicing complex contains C proteins, and it can be immunoprecipitated with 4F4. Depletion of C proteins from the splicing extract by immunoadsorption with either of the two monoclonal antibodies to the C proteins (4F4 or 2B12) results in the loss of splicing activity, whereas mock-depletion with nonimmune mouse antibodies has no effect. A 60
S
splicing complex does not form in a C protein-depleted nuclear extract. These results indicate an essential role for proteins of the hnRNP complex in the splicing of mRNA precursors.
Molecular Analysis of the t(2;14) Translocation of Childhood Chronic Lymphocytic Leukemia
Authors: Fell H. Perry , Smith R. Graham , Tucker Philip W.
Published: October 2006

Two rare cases of chronic lymphocytic leukemia (CLL) in children have been studied; both are associated with a previously undescribed chromosomal translocation [t(2;14)(p13;q32)]. In one patient the translocation was reciprocal and the breakpoint on chromosome 14 occurred just 5′ of the C
γ2
region on the productive immunoglobulin heavy-chain allele. The breakpoint on chromosome 2 does not involve the κ locus but lies within an uncharacterized region that coincides with the position of a constitutive fragile site that occurs within normal lymphocytes. Data on the second patient are consistent with these findings and suggest that these cases represent a rare but distinct subgroup of CLL's with a specific cytogenetic change.
Evidence for a Detrimental Effect of Bicarbonate Therapy in Hypoxic Lactic Acidosis
Authors: Graf Helmut , Leach William , Arieff Allen I.
Published: October 2006

Lactic acidosis, a clinical syndrome caused by the accumulation of lactic acid, is characterized by lactate concentration in blood greater than 5 m
M
. Therapy usually consists of intravenous sodium bicarbonate (NaHCO
3
), but resultant mortality is greater than 60 percent. The metabolic and systemic effects of NaHCO
3
therapy of hypoxic lactic acidosis in dogs were studied and compared to the effects of sodium chloride or no therapy. Sodium bicarbonate elevated blood lactate concentrations to a greater extent than did either sodium chloride or no treatment. Despite the infusion of NaHCO
3
, both arterial
p
H and bicarbonate concentration decreased by a similar amount in all three groups of dogs. Additional detrimental effects of NaHCO
3
were observed on the cardiovascular system, including decreases in cardiac output and blood pressure that were not observed with either sodium chloride or no treatment. Thus there is evidence for a harmful effect of NaHCO
3
in the treatment of hypoxic lactic acidosis.
Developmentally Controlled Expression of Immunoglobulin V
H
Genes
Authors: Perlmutter Roger M. , Kearney John F. , Chang Sandra P. , Hood Leroy E.
Published: October 2006

Although antibody diversity arises mainly from apparently random combinatorial and somatic mutational mechanisms acting upon a limited number of germline antibody genes, the antibody repertoire develops in an ordered fashion during mammalian ontogeny. A series of early pre-B and B-lymphocyte cell lines were examined to determine whether an ordered rearrangement of gene families of the variable region of immunoglobulin heavy chains (VH) may be the basis for the programmed development of the antibody response. The results indicated that the VH repertoire of fetal B-lineage cells is largely restricted to the VH 7183 gene family and that subsequent recruitment of additional VH gene families occurs during neonatal development. These results have important implications in understanding the ontogeny of immune function.
Diabetic Cataracts and Flavonoids
Authors: Varma S. D. , Mizuno A. , Kinoshita J. H.
Published: October 2006

Oral administration of quercitrin, an inhibitor of aldose reductase, leads to a significant decrease in the accumulation of sorbitol in the lens of diabetic
Octodon degus
. The onset of cataract is effectively delayed when quercitrin is continuously administered. Thus in these diabetic animals, as in galactosemic rats, the use of an effective aldose reductase inhibitor impedes the course of cataract development. These observations support the hypothesis that in diabetes, as in galactosemia, aldose reductase plays a key role in initiating the formation of lens opacity.
Congenital Transmission of a Papovavirus of the Stump-Tailed Macaque
Authors: Shah Keerti V. , Rangan S. R. S. , Reissig Magdalena , Daniel Richard W. , Bellhan Frank Z.
Published: October 2006

Stump-tailed macaque virus, a newly recognized papovavirus of the SV40 polyoma subgroup, was demonstrated in kidney cultures from each of five stump-tailed macaque fetuses in the second half of gestation and from six adult stump-tailed macaques. Such regular presence of virus in the fetus is an unusual feature for a papovavirus.
Migration and Differentiation of Cerebral Cortical Neurons After Transplantation into the Brains of Ferrets
Authors: McConnell Susan K.
Published: October 2006

Cells from the cerebral proliferative zones of newborn ferrets were labeled with tritiated thymidine and a fluorescent dye and were transplanted as a single-cell suspension into the occipital region of newborn ferrets. The transplanted cells became thoroughly integrated into the host environment: many cells migrated through the intermediate zone and into the cortical plate, where they developed as pyramidal neurons. Other transplanted cells came to resemble glial cells. After 1 to 2 months most transplanted neurons had taken up residence in layer 2 + 3, the normal destination of neurons generated on postnatal days 1 and 2. Thus the sequence of morphological differentiation and the eventual laminar position of the isochronically transplanted neurons closely paralleled that of their normal host counterparts.
Deficient Vasoactive Intestinal Peptide Innervation in the Sweat Glands of Cystic Fibrosis Patients
Authors: Heinz-Erian Peter , Dey Richard D. , Flux Marinus , Said Sami I.
Published: October 2006

The innervation of acini and ducts of eccrine sweat glands by immunoreactive, vasoactive intestinal peptide-containing nerve fibers was sharply reduced in seven patients with cystic fibrosis compared to eight normal subjects. The decrease in innervation by this neuropeptide, which has been shown to promote blood flow and the movement of water and chloride across epithelial surfaces in other systems, may be a basic mechanism for the decreased water content and relative impermeability of the epithelium to chloride and other ions that characterize cystic fibrosis.
Cloned Ribosomal RNA Genes from Chloroplasts of
Euglena gracilis
Authors: Lomax Margaret I. , Helling Robert B. , Hecker Lanny I. , Schwartzbach Steven D. , Barnett W. Edgar
Published: October 2006

Fragments of Euglena chloroplast DNA generated by endonuclease R⋅ Eco RI were separated by agarose-gel electrophoresis into 24 distinct bands. At least five fragments contain sequences complementary to chloroplast ribosomal RNA, Most of the Eco RI fragments have been cloned in a plasmid of Escherichia coli. Three of the cloned fragments were shown to contain chloroplast ribosomal RNA sequences by DNA-RNA hybridization.
Encoding of Spatial Location by Posterior Parietal Neurons
Authors: Andersen Richard A. , Essick Greg K. , Siegel Ralph M.
Published: October 2006

The cortex of the inferior parietal lobule in primates is important for spatial perception and spatially oriented behavior. Recordings of single neurons in this area in behaving monkeys showed that the visual sensitivity of the retinotopic receptive fields changes systematically with the angle of gaze. The activity of many of the neurons can be largely described by the product of a gain factor that is a function of the eye position and the response profile of the visual receptive field. This operation produces an eye position-dependent tuning for locations in head-centered coordinate space.
Vision Guides the Adjustment of Auditory Localization in Young Barn Owls
Authors: Knudsen Eric I. , Knudsen Phyllis F.
Published: October 2006

Barn owls raised with one ear plugged make systematic errors in auditory localization when the earplug is removed. Young owls correct their localization errors within a few weeks. However, such animals did not correct their auditory localization errors when deprived of vision. Moreover, when prisms were mounted in front of their eyes, they adjusted their auditory localization to match the visual error induced by the prisms, as long as the visual and auditory errors were within the same quadrant of directions. The results demonstrate that, during development, the visual system provides the spatial reference for fine-tuning auditory localization.
Swine Influenza Virus Vaccine: Potentiation of Antibody Responses in Rhesus Monkeys
Authors: Stephen E. L. , Hilmas D. E. , Mangiafico J. A. , Levy H. B.
Published: October 2006

Polyriboinosinic-polyribocytidylic acid stabilized with poly-L-lysine and carboxymethylcellulose [poly(ICLC)] enhances the antibody response in rhesus monkeys immunized with swine influenza virus subunit vaccine. Monkeys given the vaccine-adjuvant combination had earlier and significantly (P < .05) higher titers by 14 days compared to those that received vaccine alone. The potentiation of the antibody response of young monkeys given a split-virus vaccine in combination with poly(ICLC) suggests that this vaccine-adjuvant combination may similarly provide a potentially useful alternative approach to the immunization of pediatric and young adult age groups against swine influenza.
Acceleration of Plasma Bicarbonate Conversion to Carbon Dioxide by Pulmonary Carbonic Anhydrase
Authors: Effros Richard M. , Chang Robert S. Y. , Silverman Phillip
Published: October 2006

In isolated rabbit lungs perfused with solutions containing little or no carbonic anhydrase activity, nearly complete equilibration between H
14
CO
3
-
and
14
CO
2
occurs during a single circulation. This equilibration can be inhibited by blocking pulmonary carbonic anhydrase with acetazolamide.
Hv(1), a Variable-Region Genetic Marker of Human Immunoglobulin Heavy Chains
Authors: Wang A. C. , Mathur S. , Pandey J. , Siegel F. P. , Middaugh C. R. , Litman G. W.
Published: October 2006

A new antigenic determinant was discovered with a hemagglutination-inhibition assay system. Designated Hv(1), it is located in the variable region of human immunoglobulin heavy chains of the G, M, and A classes. Pedigree and population analyses suggest that it has an autosomal dominant mode of inheritance. This represents the first description of an allotypic determinant in the variable region of human immunoglobulins.
Vitamin D Deficiency and Reproduction in Rats
Authors: Halloran B. P. , DeLuca H. F.
Published: October 2006

Female weanling rats from a colony maintained on a diet low in vitamin D were raised on a diet that was deficient in vitamin D but was otherwise adequate. Vitamin D deficiency was confirmed in the rats by hypocalcemia and the absence of vitamin D metabolites in blood. These females gave birth to litters that were slightly smaller than control litters from females maintained on a vitamin D-containing diet. The pups from the vitamin D-deficient mothers appeared normal throughout lactation, and at weaning had normal concentrations of calcium and phosphate in the plasma. These results indicate that vitamin D and its metabolites are not necessary for reproduction and fetal development in the rat.
Melatonin Synthesis by the Retina
Authors: Gern William A. , Ralph Charles L.
Published: October 2006

Melatonin fulfills many of the criteria for classification as a hormone. Until recently it was considered to be elaborated exclusively by pineal organs. Melatonin synthesis by other tissues has been indicated but not demonstrated unequivocally. Trout retinas in a whole-organ culture system in vitro synthesized tritiated melatonin from a substrate containing tritiated serotonin. This raises the possibility that the trout retina is an endocrine organ.
Alteration of Cortical Orientation Selectivity: Importance of Asymmetric Input
Authors: Gordon Barbara , Presson Joelle , Packwood James , Scheer Robert
Published: October 2006

Rearing cats so that each of the two eyes sees stripes of a different orientation alters the orientation preference of visual cortex cells. This result can be obtained by rearing the cats in striped cylinders or with goggles attached to their faces, but a tighter control of orientation preference is achieved by the goggles.
Intracephalic Implants: A Technique for Studying Neuronal Interactions
Authors: Kromer Lawrence F. , Björklund Anders , Stenevi Ulf
Published: October 2006

Implants of embryonic neural tissue from all regions of the neuraxis survive grafting to the brains of adult rats. After implantation, neurogenesis and differentiation continue, and connections are formed with the mature host brain. Thus, the intracephalic implants provide excellent model systems for studying cellular interactions that regulate synaptogenesis and determine the cytoarchitectonic organization of developing neural tissues.
C
26
Sterol in a Human Urine
Authors: Ikekawa Nobuo , Fujimoto Yoshinori , Isiguro Masaji , Suwa Seizo , Hirayama Yasuko , Mizunuma Hiroshi
Published: October 2006

A new C
26
sterol, 22-
trans
-27-norcholesta-5,22-dien-3β-ol, was found in the urine of a 6-year-old girl, with a clinical diagnosis of congenital adrenal hyperplasia of the salt losing type, accompanied by symptoms of mixed sex anatomy and skin pigmentation. The structure of the sterol was determined by comparison with the synthetic compound. The sterol was also detected in the serum. This appears to be the first case in which a C
26
sterol has occurred in mammalia.
GABA Receptors in Clonal Cell Lines: A Model for Study of Benzodiazepine Action at Molecular Level
Authors: Baraldi M. , Guidotti A. , Schwartz J. P. , Costa E.
Published: October 2006

A "receptor unit" for γ-aminobutyric acid (GABA), which includes brainlike receptor binding sites for tritium-labeled GABA and benzodiazepines (diazepam, clonazepam, and flunitrazepam) and a thermostable endogenous protein (GABA modulin) that inhibits both GABA and benzodiazepine binding, has been demonstrated in membranes prepared from NB
2a
neuroblastoma and C6 glioma clonal cell lines. In these cells, as in brain, diazepam (1 micromolar) prevents the effect of GABA modulin, and in turn GABA (0.1 millimolar) increases the binding of [
3
H]diazepam. The neuroblastoma and, to a lesser extent, the glioma cells represent a suitable model to study the interactions and the sequence of membrane and intracellular events triggered by the stimulation of benzodiazepine and GABA receptors.
α-Melanocyte-Stimulating Hormone: Reduction in Adult Rat Brain After Monosodium Glutamate Treatment of Neonates
Authors: Eskay R. L. , Brownstein M. J. , Long R. T.
Published: October 2006

Intraperitoneal injection of monosodium glutamate in neonatal rats resulted in a 90 percent loss of α-melanocyte-stimulating hormone in hypothalamic and extrahypothalamic areas of the brain, whereas the amount of hormone in the pituitary gland did not change. The dramatic reduction of α-melanocyte-stimulating hormone in the brain suggests that its primary source there is the neuronal perikarya of the arcuate nucleus.
Novel Activation Mechanism for the Promutagenic Herbicide Diallate
Authors: Schuphan Ingolf , Rosen Joseph D. , Casida John E.
Published: October 2006

The potent bacterial mutagen 2-chloroacrolein is formed from the carcinogenic herbicide
S
-2,3-dichloroallyl diisopropylthiocarbamate (diallate) on incubation with hepatic microsomal monooxygenases or on reaction with
m
-chloroperbenzoic acid. A proposed activation mechanism for this promutagen involves sulfoxidation followed by [2,3] sigmatropic rearrangement and 1,2-elimination reactions. A portion of the highly reactive intermediate, diallate sulfoxide (proximate mutagen), is attacked by glutathione in a reaction which competes with its transformation to the ultimate mutagen, 2-chloroacrolein.
Iodine-125—Labeled Estradiol: a Gamma-Emitting Analog of Estradiol That Binds to the Estrogen Receptor
Authors: Hochberg Richard B.
Published: October 2006

17β-[16α-
125
I]Iodoestradiol has been synthesized by exchange of 16β-bromoestradiol with Na
125
I. The iodinated product is readily separated from the bromo reactant by column chromatography. It concentrates in the rat uterus in vivo and binds avidly and specifically to the uterine estrogen receptor in vitro.
Calcification of Differentiating Skeletal Mesenchyme in Vitro
Authors: Binderman I. , Greene R. M. , Pennypacker J. P.
Published: October 2006

Embryonic limb-bud mesenchyme was induced to calcify in culture by the addition of 3 m
M
inorganic phosphate to the medium. Phosphate enhanced calcification of the matrix produced by mesenchymal or fibroblast-like cells, whereas no calcification was evident in areas where cartilage had developed. However, calcification was induced throughout the cell layer by altering the cartilage matrix properties with certain enzymes or by changing the phenotypic expression of the cells with vitamin A.
Golgi Complex—Endoplasmic Reticulum Transition Region Has Rings of Beads
Authors: Locke M. , Huie P.
Published: October 2006

The smooth surface of the rough endoplasmic reticulum that makes the forming face of the Golgi complex has beadlike structures arranged in rings at the base of transition vesicles. The beads can only be seen easily after staining in bismuth salts. They are 10 to 12 nanometers in diameter and occur in a variety of cell types and organisms.
Can an Ape Create a Sentence?
Authors: Terrace H. S. , Petitto L. A. , Sanders R. J. , Bever T. G.
Published: October 2006

More than 19,000 multisign utterances of an infant chimpanzee (Nim) were analyzed for syntactic and semantic regularities. Lexical regularities were observed in the case of two-sign combinations: particular signs (for example,more) tended to occur in a particular position. These regularities could not be attributed to memorization or to position habits, suggesting that they were structurally constrained. That conclusion, however, was invalidated by videotape analyses, which showed that most of Nim's utterances were prompted by his teacher's prior utterance, and that Nim interrupted his teachers to a much larger extent than a child interrupts an adult's speech. Signed utterances of other apes (as shown on films) revealed similar nonhuman patterns of discourse.
Estradiol Shortens the Period of Hamster Circadian Rhythms
Authors: Morin Lawrence P. , Fitzgerald Kathleen M. , Zucker Irving
Published: October 2006

Continuous administration of estradiol benzoate by means of subcutaneously implanted capsules shortened the free-running circadian period of locomotor activity of blind hamsters (
Mesocricetus auratus
) that had had their ovaries removed. Estradiol also advanced the phase of the wheel running of sighted female hamsters without ovaries that were entrained to a photoperiod with 12 hours of light and 12 of darkness. These results, and findings from hamsters undergoing natural estrous cycles, indicate that endogenous estradiol is involved in the regulation of circadian periodicity.
Diazepam Inhibits Myoblast Fusion and Expression of Muscle Specific Protein Synthesis
Authors: Bandman Everett , Walker Charles R. , Strohman Richard C.
Published: October 2006

The presence of diazepam in cultures of chicken embryo myoblasts arrests normal muscle cell differentiation. High concentrations of the drug reversibly prevent myoblasts from fusing to form multinucleated myotubes. Lower concentrations of diazepam allow cell fusion to occur, but inhibit the synthesis and accumulation of myosin heavy chain, implying that cell fusion does not obligate myoblasts to synthesize and accumulate large quantities of muscle specific protein. The effect of diazepam on muscle cells in culture is direct and specific.
Preparation of Sarcolemmal Membrane from Myocardial Tissue Culture Monolayer by High-velocity Gas Dissection
Authors: Langer G.A. , Frank J.S. , Philipson K.D.
Published: October 2006

A high-velocity stream of nitrogen is used to simultaneously disrupt myocardial cells in monolayer culture and fractionate their sarcolemmal membranes. The membranes show a high degree of ultrastructural and enzymatic purity, with less than 1 percent intracellular residuum. They are produced in less than 1 second and remain as tightly adherent sheets on the surface on which the cells were grown. The cells are exposed to no agent other than nitrogen gas during the preparative procedure.
Hormone Changes Triggered by Aggression in a Natural Population of Blackbirds
Authors: Harding Cheryl F. , Follett Brian K.
Published: October 2006

The concentrations of hormones in the plasma of male red-winged blackbirds caught at the height of an aggressive encounter are significantly different from those in males that have not recently engaged in aggressive behavior. Concentrations of luteinizing hormone in the plasma are decreased in the aggressive males, whereas androgen concentrations are affected in a more complex manner. Concentrations of corticoids do not appear to be affected by aggressive behavior.
Biophysical Studies of Ion Channels
Authors: Stevens Charles F.
Published: October 2006

Ionic channels, the integral membrane proteins responsible for the brain's electrical activity, have long been studied with standard electrophysiological and biochemical methods. Recently, however, newly developed electrical and molecular biological methods have been brought to bear on long-standing questions in neurobiology. Goals of current channel research include elucidating the primary amino acid sequence and three-dimensional structure of channel species; the mechanisms of synthesis, sorting, membrane insertion, and degradation; and aspects of function such as gating, ion permeation and selectivity, and regulation. The latest research combines the new biochemical and electrophysiological techniques to reveal relations between molecular structure and function.
A Single Troponin T Gene Regulated by Different Programs in Cardiac and Skeletal Muscle Development
Authors: Cooper Thomas A. , Ordahl Charles P.
Published: October 2006

A cloned complementary DNA derived from a messenger RNA transiently present at low abundance levels in early chick embryonic skeletal muscle hybridizes to a messenger RNA present at high abundance levels in cardiac muscle. Genomic DNA hybridization and nucleotide sequence identity of complementary DNA's from both heart and skeletal muscle demonstrate that the messenger RNA's from both sources are encoded by the same gene. The encoded polypeptide is a troponin T sequence which is probably a cardiac isoform. This single copy troponin T isogene is governed by different regulatory programs in heart and skeletal muscle differentiation.
A System of "Definitive Units" Proposed for Universal Use
Authors: Campbell George A.
Published: October 2006

It is proposed that physicists discard the CGS and Heaviside units, which are responsible for much confusion and needless mental effort, and employ exclusively a single system of "definitive units." The units suggested include the international meter, the international kilogram, the second, the mechanical watt, the international mercury ohm and they conform with the other international units as closely as is compatible with self-consistency. The system is not only definite and absolute, but also comprehensive, readily visualized and, in large part, already employed under well-established names. The system was proposed in 1901 by Giorgi and in 1904 by Robertson but received scant attention on account of the artificial prestige of the CGS system. A single universal system of units should be the ultimate goal, and the "definitive units" are chosen with a view to their adoption not only by all scientists but also by the butcher, the baker and the candlestick-maker.

The definitive system of units makes it perfectly feasible to employ a single system much more generally than has ever been the case in the past; the natural ultimate goal is the universal use of these units for all purposes. In the attempt to extend the application of metric units in the United States the meter-stere-kilogram, rather than the meter-liter-gram, should form the basis for legislation, in order to give definitive units their proper legalized status and to secure to the full the advantages of a comprehensive system consistently interrelated with the legalized international electrical units. The gradual discarding of CGS and other redundant units would inevitably follow. Even in the absence of official recognition of definitive units, individuals may advantageously employ the system. This would cause confusion neither to authors nor readers, since these units, in the main, have already acquired vital existence through world-wide, daily use under familiar, well-established names.
β-Adrenergic Regulation of α
3
-Adrenergic Receptors in the Central Nervous System
Authors: Maggi Adriana , U'Prichard David C. , Enna S. J.
Published: October 2006

Incubation of rat cerebral cortical slices with the β-adrenergic agonist isoproterenol causes an increase in α
2
-adrenergic receptor binding in addition to a decrease in β-adrenergic receptor binding. The effects are rapid and reversible, show a parallel time course, and are blocked by sotalol, a β-adrenergic receptor antagonist. The β-mediated regulation of α
2
-receptor sensitivity at brain norepinephrine synapses may be a mechanism for the homeostatic control of central noradrenergic activity.
Sea Anemone Neuromuscular Responses in Anaerobic Conditions
Authors: Mangum Dorothea C.
Published: October 2006

The sea anemone
Bunodosoma cavernata
survives anoxic conditions for as long as 6 weeks. Whether or not oxygen is present, its neuromuscular responses are the same and the pulses of its nerve net have the same threshold size and shape.
Bunodosoma cavernata
buried in the sand during a low tide are exposed to anoxic conditions. Their neuromuscular responses in anaerobic conditions ensure protective withdrawal behavior should the need arise.
Lophotoxin: a Novel Neuromuscular Toxin from Pacific Sea Whips of the Genus
Lophogorgia
Authors: Fenical William , Okuda Roy K. , Bandurraga Maury M. , Culver Paul , Jacobs Robert S.
Published: October 2006

A new neuromuscular toxin, lophotoxin, has been isolated from several Pacific gorgonians of the genus
Lophogorgia
. The structure of lophotoxin was deduced by combined spectrochemical methods, and belongs to the well-known cembrene class of diterpenoid molecules. Lophotoxin contains furanoaldehyde and α,β-epoxy- γ-lactone functional groups, in sharp contrast to the cationic ammonium functional groups of the established neurotoxins.
Islets of Langerhans: Dye Coupling Among Immunocytochemically Distinct Cell Types
Authors: Michaels Robin L. , Sheridan Judson D.
Published: October 2006

Cells in isolated rat islets of Langerhans were microinjected with Lucifer Yellow CH in a medium containing 16.7 millimolar glucose. Dye was rapidly transferred from the injected cell to neighboring islet cells without specificity with regard to the immunocytochemical identity of either the donor or the recipient cells. The transfer of dye between the islet cells (types A, B, and D) demonstrates homologous and heterologous cell coupling in a system where the normal proportions and relationships of the cell types are maintained.
Alzheimer's Disease: Insolubility of Partially Purified Paired Helical Filaments in Sodium Dodecyl Sulfate and Urea
Authors: Selkoe Dennis J. , Ihara Yasuo , Salazar Fernando J.
Published: October 2006

A method is described for the partial purification of the paired helical filaments that accumulate progressively in human neurons in Alzheimer's disease (senile dementia). Paired helical filaments have unusual solubility characteristics, including insolubility in sodium dodecyl sulfate, urea, reducing agent, and guanidine, which prevent analysis of their molecular composition by gel electrophoresis. The paired helical filaments appear to contain covalent bonds other than disulfide, which cross-link individual filaments into a rigid intracellular polymer. Thus, paired helical filaments appear to represent an example in neurons of an insoluble cross-linked protein. Covalently cross-linked protein polymers occur in lens senile cataracts and in terminally differentiated skin keratinocytes, suggesting that there may be a common mechanism for remodeling some structural proteins during cell aging.
A Diurnal Rhythm in Pineal Protein 1 Content Mediated by β-Adrenergic Neurotransmission
Authors: Nestler Eric J. , Zatz Martin , Greengard Paul
Published: October 2006

A diurnal rhythm was found in the total amount of the neuron-specific phosphoprotein protein 1 in rat pinealocytes. β-Adrenergic neurotransmission appears to be the mechanism regulating the amount of pineal protein 1 in vivo.
Dopamine-β-Hydroxylase Activity and Homovanillic Acid in Spinal Fluid of Schizophrenics with Brain Atrophy
Authors: van Kammen Daniel P. , Mann Lee S. , Sternberg David E. , Scheinin Mika , Ninan Philip T. , Marder Stephen R. , van Kammen Welmoet B. , Rieder Ronald O. , Linnoila Markku
Published: October 2006

Schizophrenic patients with high ventricle brain ratios and cortical brain atrophy, as shown by computerized tomography, had decreased spinal fluid concentrations of homovanillic acid and dopamine-β-hydroxylase activity. These decreased cerebral spinal fluid concentrations in patients with brain atrophy support the proposal of disturbed noradrenaline and dopamine neurotransmission in a subgroup of schizophrenic patients.
Neurotransmitter Plasticity at the Molecular Level
Authors: Black I. B. , Adler J. E. , Dreyfus C. F. , Jonakait G. M. , Katz D. M. , LaGamma E. F. , Markey K. M.
Published: October 2006

Contrary to long-held assumptions, recent work indicates that neurons may profoundly change transmitter status during development and maturity. For example, sympathetic neurons, classically regarded as exclusively noradrenergic or cholinergic, can also express putative peptide transmitters such as substance P. This neuronal plasticity is directly related to membrane depolarization and sodium ion influx. The same molecular mechanisms and plastic responses occur in mature as well as developing neurons. Further, contrary to traditional teaching, adult primary sensory neurons may express the catecholaminergic phenotype in vivo. Transmitter plasticity is not restricted to the peripheral nervous system: ongoing studies of the brain nucleus locus ceruleus in culture indicate that specific extracellular factors elicit marked transmitter changes. Consequently, neurotransmitter expression and metabolism are dynamic, changing processes, regulated by a variety of defined factors. Transmitter plasticity adds a newly recognized dimension of flexibility to nervous system function.
Immunological Approaches to the Nervous System
Authors: Reichardt Louis F.
Published: October 2006

Immunology has had a major impact on neurobiology, expanding dramatically the number of subjects amenable to investigation. Studies with antibodies to neuropeptides, transmitters, and transmitter enzymes have disclosed a great heterogeneity among neurons and have provided clues for interpreting anatomical connections. Monoclonal antibodies are being used to identify functionally related subpopulations of neurons and cell lineages in development and to study mechanisms by which axons grow along stereotypic pathways to reach their targets. Other antibodies have identified molecules that appear to participate in cell aggregation, cell migration, cell position, and axon growth. Antibodies have revealed that many proteins are concentrated in anatomically distinct regions of the neuron. Moreover, these studies have suggested that individual proteins have different antigenic epitopes shielded or modified in different parts of the same neuron. Antibodies to membrane proteins crucial for neuronal function, such as ion pumps, ion-selective channels, and receptors, have been used to map their distributions and to study their structures at high resolution.
Order in the Optic Nerve of Goldfish
Authors: Rusoff Anne C. , Easter Stephen S.
Published: October 2006

A small amount of horseradish peroxidase, injected into the goldfish optic nerve and transported into the retina, filled an annulus of ganglion cells. Since the retina grew by annular addition of cells, this result shows that axons from cells of similar age clustered together in the nerve.
Evolutionary Conservation of Repetitive Sequence Expression in Sea Urchin Egg RNA's
Authors: Moore Gordon P. , Costantini Franklin D. , Posakony James W. , Davidson Eric H. , Britten Roy J.
Published: October 2006

Cloned repetitive DNA sequences were used to determine the number of homologous RNA transcripts in the eggs of two sea urchin species,
Strongylocentrotus purpuratus
and
S. franciscanus
. The eggs of these species contain different amounts of RNA, and their genomes contain different numbers of copies of the cloned repeats. The specific pattern of repetitive sequence representation in the two egg RNA's is nonetheless quantitatively similar. The evolutionary conservation of this pattern suggests the functional importance of repeat sequence expression.
Inhibition of Biological Activity of Mouse β-Nerve Growth Factor by Monoclonal Antibody
Authors: Warren Stephen L. , Fanger Michael , Neet Kenneth E.
Published: October 2006

A continuous hybrid cell line was derived that secretes monoclonal antibody capable of inhibiting the biological activity of mouse β-nerve growth factor (β-NGF). Results obtained with monovalent fragments indicate that the monoclonal antibody inhibits activity by interfering with the direct interaction between β-NGF and the cell membrane receptor rather than by precipitating the dimeric form of β-NGF. This monoclonal antibody binds to an antigenic determinant common to mouse β-NGF, snake venom (
Naja naja
) β-NGF, and human β-NGF. These antibodies should provide specific molecular probes for a variety of studies of nerve growth factor including its tissue distribution and mechanism of action.
Axonal Elongation into Peripheral Nervous System "Bridges" After Central Nervous System Injury in Adult Rats
Authors: David Samuel , Aguayo Albert J.
Published: October 2006

The origin, termination, and length of axonal growth after focal central nervous system injury was examined in adult rats by means of a new experimental model. When peripheral nerve segments were used as "bridges" between the medulla and spinal cord, axons from neurons at both these levels grew approximately 30 millimeters. The regenerative potential of these central neurons seems to be expressed when the central nervous system glial environment is changed to that of the peripheral nervous system.
Crystallization of Recombinant Human Leukocyte Interferon A
Authors: Miller David L. , Kung Hsiang-Fu , Pestka Sidney
Published: October 2006

Crystals of recombinant human leukocyte interferon A (IFLrA) were prepared, and their composition was characterized. These studies should provide the foundation for determination of the tertiary structure of IFLrA by x-ray crystallography.
Presynaptic Location and Axonal Transport of β
1
-Adrenoreceptors in the Rat Brain
Authors: Levin Barry E.
Published: October 2006

Interruption of the ascending noradrenergic neurons of the locus coeruleus in the rat forebrain with 6-hydroxydopamine produced a progressive accumulation, proximal to the lesion, of tritiated dihydroalprenolol binding activity over 2 days. This accumulation could be blocked by interrupting the neurons closer to their cell bodies. Competitive binding studies with the β
2
agonist Zinterol suggested that the accumulated β-receptors were primarily of the β
1
subtype. These results suggest that, in the rat brain, some β
1
-adrenoreceptors are located in presynaptic, noradrenergic locus coeruleus neurons and are transported in their axons.
Shark Cartilage Contains Inhibitors of Tumor Angiogenesis
Authors: Lee Anne , Langer Robert
Published: October 2006

Shark cartilage contains a substance that strongly inhibits the growth of new blood vessels toward solid tumors, thereby restricting tumor growth. The abundance of this factor in shark cartilage, in contrast to cartilage from mammalian sources, may make sharks an ideal source of the inhibitor and may help to explain the rarity of neoplasms in these animals.
Perfusion Preservation of Hearts for 6 to 9 Days at Room Temperature
Authors: Linask Juri , Votta John , Willis Minetta
Published: October 2006

The combination of a defined medium with single-pass perfusion has made possible long-term maintenance of beating rat hearts at 22°C in vitro. The 6- to 9-day survival period appears to be the longest so far reported for hearts. This method provides a stable system which should be useful for investigating the role of single factors in myocardial preservation and evaluating the effects of exposure to pharmacological and toxicological agents.
High-Frequency Transfection and Cytopathology of the Hepatitis B Virus Core Antigen Gene in Human Cells
Authors: Yoakum George H. , Korba Brent E. , Lechner John F. , Tokiwa Takayoshi , Gazdar Adi F. , Seeley Todd , Siegel Mary , Leeman Lawrence , Autrup Herman , Harris Curtis C.
Published: October 2006

A protoplast fusion method was developed to stably transfect human cells with pSV2-derived plasmids at frequencies greater than 10(-3). This procedure made it possible to test the biological effect of a hepatitis B virus (HBV) gene independent of the viral structures required for infection. A pSV2gpt+ plasmid constructed to carry a subgenomic fragment of HBV that contained the core antigen gene (HBc gene) was transfected into human cells. A human epithelial cell line was stably transfected with the HBc+ gene by selecting recipient cells for expression of guanine phosphoribosyl transferase expression. With this gpt+/HBc+ cell line it was shown that growth in serum-free medium or treatment with 5'-azacytidine stimulates the production of the HBV core antigen. A hepatocellular carcinoma carrying the entire HBV genome was stimulated to produce the HBc gene product in response to the same factors that stimulated HBcAg production in the gpt+/HBc+ cell line constructed by transfection. The temporal relation between the cytopathologic response and HBc gene expression was similar for both cell types, indicating a primary role for HBc gene expression in the cytopathology of HBV-infected human liver.
Partial Characterization of 21.5K Myelin Basic Protein from Sheep Brain
Authors: Carnegie P. R. , Dowse C. A.
Published: October 2006

The 21,500 molecular weight (21.5K) variant of myelin basic protein (MBP) was isolated from sheep brain and partially characterized. Digestion with cyanogen bromide and trypsin yielded peptides which showed that approximately 30 additional amino acids were inserted at the equivalent of the amino acid at position 57 in the bovine 18.5K MBP sequence. An unusually hydrophobic peptide Pro, Val, Leu, Trp, Lys was present in this region. Ornithine was present in hydrolyzates of 21.5K MBP, but it was not detected in any of the peptides.
Catalytic Activity of an RNA Molecule Prepared by Transcription in Vitro
Authors: Guerrier-Takada Cecilia , Altman Sidney
Published: October 2006

Ribonuclease P is a ribonucleoprotein that cleaves precursors to transfer RNA (tRNA) molecules to yield the correct 5′ terminal sequences of the mature tRNA's. The RNA moiety M1 RNA of ribonuclease P from
Escherichia coli
and the unprocessed transcript prepared in vitro of the gene for M1 RNA can both perform the cleavage reactions of the canonical enzyme in the absence of the protein moiety. When the transcript of the M1 RNA gene is combined with the protein moiety not only is a tRNA precursor cleaved but also the precursor to 4.5
S
RNA from
Escherichia coli
.
Heparin Affinity: Purification of a Tumor-Derived Capillary Endothelial Cell Growth Factor
Authors: Shing Y. , Folkman J. , Sullivan R. , Butterfield C. , Murray J. , Klagsbrun M.
Published: October 2006

A tumor-derived growth factor that stimulates the proliferation of capillary endothelial cells has a very strong affinity for heparin. This heparin affinity makes it possible to purify the growth factor to a single-band preparation in a rapid two-step procedure. The purified growth factor is a cationic polypeptide, has a molecular weight of about 18,000, and stimulates capillary endothelial cell proliferation at a concentration of about 1 nanogram per milliliter.