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101.
Based on statistical variance as an index of electroencephalogram (EEG) parameters, we monitored slow-wave sleep in both humans and rats in real time and on-line with a widely used personal computer. This EEG variance method may be a useful tool to carry out biological rhythm research, including sleep studies. 相似文献
102.
N P Kurstjens H Heithier R C Cantrill M Hahn F Boege 《Biochemical and biophysical research communications》1990,167(3):1162-1169
Glucagon and prostaglandin E1 stimulate adenylate cyclase in Madin-Darby canine kidney cells with an approximate EC50 of 3*10(-8) and 1*10(-7) M respectively. The rise in cAMP is accompanied by a transient rise in intracellular Ca++ measured with the fluorescent calcium indicator Indo-1. A comparable increase in intracellular Ca2+ without a rise in cAMP occurs with the cholinergic agonist carbamylcholine. Stimulation of adenylate cyclase by the beta-adrenergic agonist isoproterenol or directly by forskolin has no effect on intracellular Ca++. By all criteria studied the rise in intracellular Ca++ and the increase in cAMP are independent from each other. 相似文献
103.
Sequence and developmental expression of the mRNA encoding the seleno-protein of the sperm mitochondrial capsule in the mouse 总被引:1,自引:0,他引:1
K C Kleene J Smith A Bozorgzadeh M Harris L Hahn I Karimpour J Gerstel 《Developmental biology》1990,137(2):395-402
We have characterized cDNA clones encoding the selenium-containing polypeptide of the keratinous mitochondrial capsule in mouse sperm. The longest open reading frame encodes a polypeptide 143 amino acids long which contains 21% cysteine and 27% proline and closely resembles the size and amino acid composition of bull mitochondrial capsule seleno-protein (V. Pallini, B. Baccetti, and A. G. Burrini, 1979, in "The Spermatozoon," D. W. Fawcett and J. M. Bedford, Eds., pp. 141-151, Urban & Schwartzenberg, Baltimore/Munich). The reading frame encoding the mitochondrial capsule seleno-protein ends with an amber stop codon suggesting that selenium is not incorporated cotranslationally into the protein by an opal suppressor selenocysteyl-tRNA as has been found for several eukaryotic and bacterial proteins. Northern blots using RNA extracted from purified spermatogenic cells and staged prepuberal mice suggest that the mitochondrial capsule seleno-protein mRNA is first transcribed in late meiotic cells and that the levels of the mRNA increase after meiosis in early haploid cells. Southern blots demonstrate that there is one copy of the gene in the mouse genome. The identification of this cDNA clone, in combination with previous work (K. C. Kleene, 1989, Development 106, 367-373) demonstrates that the mRNA for the mitochondrial capsule seleno-protein is translationally repressed with long homogenous poly(A) tracts in round spermatids and translationally active with shortened heterogenous poly(A) tracts in elongating spermatids. 相似文献
104.
Physical parameters affecting the rate and completion of RNA driven hybridization of DNA: new measurements relevant to quantitation based on kinetics. 总被引:10,自引:2,他引:8
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Differences in the RNA-driven hybridization kinetics of genomic DNA and cDNA probes led us to examine physical parameters affecting these reactions. Cloned cDNA complementary to serum albumin (SA) mRNA hybridized in accordance with single component kinetics, whereas cloned SA genomic DNA hybridized more slowly and with multiple component kinetics. This difference is largely attributable to the relatively short and variable lengths of the mRNA complementary regions in the cloned genomic DNA. The rate of mRNA driven hybridization is affected to about half the extent observed for DNA renaturation as Na+ is increased or decreased from 0.18M. In the annealing of nucleic acids of high sequence complexity, after approximately 70% of reaction has been reached, the rate of the reaction is slowed and completion is not reached under "static" conditions. In practical terms, this is not the case for systems of low sequence complexity. This problem can be largely overcome by continuous or frequent mixing of the reactants, so that complex cDNA probes are hybridized essentially to completion, and kinetics can therefore be more readily compared to simple complexity standards. 相似文献
105.
Carl R. Woese Paul Blanz Robert B. Hespell Christine M. Hahn 《Current microbiology》1982,7(2):119-124
Helical bacteria from the generaSpirillum, Oceanospirillum, Aquaspirillum, andAzospirillum—as well asSerpens flexibilis—were characterized by oligonucleotide cataloging of 16S rRNA in order to establish their phylogenetic relationships to one another and to Gramnegative bacteria in general. The various genera of helical bacteria are not specifically related to one another (to the exclusion of nonhelical bacteria) and, where tested, the individual genera as presently constituted are not phylogenetically coherent (with the possible exception ofOceanospirillum, which may form a deep grouping). 相似文献
106.
A. Dorn H. G. Bernstein A. Rinne H.-J. Hahn M. Ziegler 《Histochemistry and cell biology》1982,74(2):293-300
Summary The localization and regional distribution of insulin-like immunoreactivity (IRI) was studied in human brain autopsy material using the indirect immunofluorescence technique. A positive reaction for IRI could be observed in many neurons of the hypothalamus, the hippocampus, corpus amygdaloideum, medulla oblongata (especially within the nuclei of cranial nerves IX, X and XII), and the cerebral cortex, whereas the cerebellar cortex was lacking in immunohistochemically detectable insulin-like material. No nerve fibres containing polypeptides could be revealed. Additionally, the inuslin content of various brain regions was estimated by radioimmunosassay. Insulin concentrations in human nervous tissue were found to be elevated in comparison to blood plasma levels.The present investigation was supported by the HFR Neurobiologie und Hirnforschung and the HFR Diabetes mellitus und Fettstoffwechselstörungen of the GDR (Ministries of Higher Education and Health respectively) and the Finnish Ministry of Education 相似文献
107.
An
model for studying factors related to dysmenorrhea and for evaluating drugs for their inhibitory effects on uterine contractility induced by arachidonic acid and prostaglandins has been developed. Intravenous administration of arachidonic acid and PGF2α to guinea pigs during the late stage of the estrous cycle, induced dose related uterine contractions and an elevation in uterine basal pressure similar that seen in patients with dysmenorrhea. Pretreatment with prostaglandin synthetase inhibitors inhibited the response to arachidonic acid. The order of relative potency was suprofen (1) > indomethacin (0.65) > naproxen (0.52) > ibuprofen (0.43) > aspirin (0.31). The effectiveness of maximal response for suprofen was significantly greater than that of the other compounds tested. Simultaneous administration of suprofen with PGF2α also blocked induction of uterine contractions, suggesting the possibility that suprofen also antagonizes PGF2α receptor binding. Bradykinin also induced uterine constractions, an effect blocked by pretretment with suprofen. Finally, histochemical studies demonstrated stimulation of uterine catecholamine levels (norepinephrine) by arachidonic acid, PGF2α and bradykinin. These effects were blocked by suprofen.These data suggest that suprofen, an analgesic prostaglandin synthetase inhibitor, may be of use in the clinical tretment of the uterine contractions associated with primary dysmenorrhea. 相似文献
108.
Heinz Hahn 《Planta》1982,154(1):53-59
The DNA-dependent RNA polymerases I, II, and III (ribonucleosidetriphosphate: RNA nucleotidyl-transferase, EC 2.7.7.6) from Achlya ambisexualis E87 (male), have been isolated. The highly purified RNA polymerase I was found to be composed of polypeptides with the following molecular weights (·10-4): 18.5, 14, 11.8, 7.3, 6.1, 4.9, 4.4, 2.8. RNA polymerase II showed a 400-fold higher resistance against -amanitin than mammalian or higher plant RNA polymerase II. 相似文献
109.
When cultured Chinese hamster cells were exposed to 43°C hyperthermia, effects due to glucose deprivation and to the presence of the uncoupler of oxidative phosphorylation, carbonylcyanide-3-chlorophenylhydrazone, during the 43°C treatment proved to be strongly accelerated compared to the effects at normal temperature (37°C). This strongly indicates that the availability of energy plays an important role in the response of these cells to hyperthermia. One of the reasons cells die after hyperthermia may be a lethal lack of energy. Cells heated before glucose deprivation were able to maintain viability for a longer period during deprivation than cells without the preheat treatment. As the cells might develop thermotolerance after the heat exposure, this suggests that cells in the thermotolerant state use energy in a more economical way. 相似文献
110.
T Diamantstein M Klos H Hahn S H Kaufmann 《Journal of immunology (Baltimore, Md. : 1950)》1981,126(5):1717-1719
Suppressor T cells of humoral immune responses, effector T cells mediating DTH, suppressor T cells of DTH, and helper T cells of humoral immune responses, all with specificity to SRBC, were produced in mice. The biologic activity was tested in adoptive transfer experiments. In vitro treatment with different doses of 4-hydroperoxycyclophosphamide (4-HPCy) yielded the result that the various activities tested were not uniformly sensitive to the action of this drug: Suppressor T cells of humoral immune responses and effector T cells mediating DTH were resistant to doses of 4-HPCy that eliminated the activities of suppressor T cells of DTH and helper cells of the humoral immune response. These findings help to explain the various effects cyclophosphamide has on the in vivo immune response and may help to form a basis for the rational manipulation of the immune response by drugs that selectively affect different subgroups of immune cells. 相似文献