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101.
102.
Quantitative and qualitative studies were made of the fungi of the air in Barcelona City. The genera Cladosporium and Alternaria formed two of the most important components of the fungus population studied during a two-year period running from January 1976 through January 1978. Penicillium species formed the 16.3 % of the total colonies while Aspergillus species represented only the 2.8 %. The occurrence of these genera was greatly affected by climatic conditions. An attempt was made to summariza the data of various kinds of fungi on a volumetric basis. Most of the fungi reported here have been identified as far as genera.
Résumé Une étude qualitative ainsi que quantitative a été réalisée sur la population fongique présente dans l'atmosphère de la ville de Barcelone. Les genres Cladosporium et Alternaria constituent les moisissures les plus inportantes quant à leur présence parmis la population fongique étudiée durant la période de deux ans comprise entre le mois de Janvier 1976 et le mois de Janvier 1978. Le genre Pénicillium représentait le 16.3% de la totalité des colonies isolées, tandis que le genre Aspergillus ne représentait que le 2.8%. La présence d'espéces de ces genres était largement influencée par les conditions climatologiques. Les données sur la présence des différents genres de moisissures ont été établies sur une base volumétrique. La plupart des moisissures identifiables l'ont été jusqu'au genre.相似文献
103.
ACETYLCHOLINESTERASE IN THE SUBSTANTIA NIGRA AND CAUDATE-PUTAMEN OF THE RAT: PROPERTIES AND LOCALIZATION IN DOPAMINERGIC NEURONS 总被引:3,自引:1,他引:2
Abstract— In order to examine the hypothesis that acetylcholinesterase (AChE) is contained within dopaminergic neurons of the nigro-striatal projection, the effects of selective destruction of these neurons by 6-hydroxydopamine (6-OHDA) on cholinesterase, tyrosine hydroxylase, and choline acetyltransferase in substantia nigra (SN) and caudate-putamen (CP) were studied in the rat. Four to five weeks after intraventricular or intracerebral 6-OHDA injections tyrosine hydroxylase in these structures was reduced by 90% or more. Choline acetyltransferase was not affected in the SN or CP, but cholinesterase was reduced by about 40% in the SN and by 12% in the CP. To determine that the observed decreases in cholinesterase activity reflected true AChE and not butyrylcholinesterase (BChE), further experiments were conducted on tissues from animals with intracerebral 6-OHDA lesions. (1) Substrate specificity. Acetylcholine (ACh) was replaced by either acetyl-β-methyl-choline (AcβMeCh) or butyrylcholine (BCh) in the cholinesterase assay. SN and CP from 6-OHDA lesioned rats showed 54% and 92% of control tissue cholinesterase activity respectively with AcβMeCh as substrate, in good agreement with values found using ACh. No decrease in activity toward BCh was observed. (2) Kinetics. The decrease in cholinesterase activities at different concentrations of ACh was determined. Analysis of the data revealed that cholinesterase in dopaminergic neurons was inhibited by high ACh concentrations, a characteristic property of AChE but not BChE. (3) Selective inhibitors. In the SN, cholinesterase in dopaminergic neurons was inhibited by the selective AChE inhibitors BW284C51 and ambenonium with a dose-response curve similar to erythrocyte AChE but different from serum BChE. The selective BChE inhibitor, tetraisopropylpyrophosphoramide, inhibited the enzyme in dopaminergic neurons only at concentrations which inhibited erythrocyte AChE, concentrations somewhat higher than those which inhibited serum BChE. These results support recent histochemical observations indicating that AChE is contained in dopaminergic neurons of the SN. Moreover, these experiments represent the first characterization of AChE from a homogeneous population of non-cholinergic neurons in mammalian CNS. 相似文献
104.
105.
Luttmann R Thoma M Buchholz H Lehmann J Schügerl K 《Biotechnology and bioengineering》1982,24(8):1851-1869
Based on the experimental investigations with H. polymorpha and Methylomonas M 15 in bench-scale airlift tower-loop reactors, a general distributed parameter model was developed and used to simulate to cultivation process in a 40-m-high production reactor. This general model was simplified with regard to the gas phase and loop balances and was employed to optimize cell productivity and/or profit in a 20-m-high pilot-plant airlift tower-loop reactor. Maximum cell productivity always occurs in the oxygen-transfer-limited growth range. In case of a high "penalty factor" for nonconsumed substrate, maximum profit is attained at the boundary between substrate and oxygen-transfer-limited growth. Oxygen-transfer limitation exists in the lower half of the tower, whereas in the upper half, substrate limitation prevails. The longitudinal dissolved oxygen concentration passes a minimum in this case as has been determined experimentally in the bench-scale column. The simulation results agree fairly well with the data measured in the pilot plant. 相似文献
106.
107.
Elevation of Taurine in Hippocampal Extracellular Fluid and Cerebrospinal Fluid of Acutely Hypoosmotic Rats: Contribution by Influx from Blood? 总被引:3,自引:2,他引:1
Anders Lehmann Christian Carlström Erlend A. Nagelhus† Ole Petter Ottersen† 《Journal of neurochemistry》1991,56(2):690-697
Previous work has demonstrated that there is a selective increase in extracellular taurine in the brain during acute water intoxication. One aim of the present study was to investigate whether plasma taurine contributes to this increase. To this end, the concentrations of taurine, other amino acids, and ethanolamine (EA) were measured in plasma and CSF of urethane-anesthetized rats injected with 150 ml/kg body weight of distilled water. Blood pressure, blood gases, and pH, as well as plasma and CSF osmolality, were also measured. The CSF level of albumin was quantitated to study the function of the blood-CSF barrier. In separate experiments, hippocampal microdialysis was performed to determine the effects of acute plasma hypoosmolality on extracellular amino acids. Finally, the effect of water injection on hippocampal specific gravity and tissue amino acids was assessed. Blood gases and pH were essentially unchanged after water administration. Mean arterial blood pressure increased to peak levels approximately 50 mm Hg above control. Plasma osmolality decreased rapidly, whereas the depression of CSF osmolality was slower and less pronounced. The average volume of the hippocampus increased by 8%. Water injection was accompanied by a 25-fold elevation of taurine in plasma, whereas phosphoethanolamine (PEA) and EA increased moderately. A small fraction of the increase in plasma taurine might derive from blood cells because dilution of blood in vitro led to doubled plasma levels of the amino acid. Taurine, PEA, and EA increased consistently in CSF and hippocampal microdialysates. Plasma hypoosmolality transiently opened the blood-CSF barrier is reflected by augmented CSF concentrations of albumin.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
108.
Neuronal and Glial Marker Proteins in the Evaluation of the Protective Action of MK 801 总被引:1,自引:0,他引:1
K. G. Haglid S. Wang A. Hamberger A. Lehmann C. J. Moller 《Journal of neurochemistry》1991,56(6):1957-1961
A quantitative dot immunobinding procedure was used to quantify glial [the S-100 protein and the glial fibrillary acidic (GFA) protein] and neuronal (the 68- and 200-kDa neurofilament polypeptides, neuron-specific enolase, and neuronal cell adhesion molecule) markers. A single intraperitoneal administration of 10 mg/kg of MK 801 blocked the increase of glial parameters and the decrease in content of neuronal marker proteins that occurred as the response to an N-methyl-D-aspartate (NMDA) lesion in the rat hippocampus. The degradation products of GFA protein and the 68-kDa neurofilament polypeptide that were induced by the NMDA lesion did not appear after MK 801 treatment. This study shows that brain-specific proteins are a set of precise tools for the evaluation of neuroprotective effects of antagonists to excitatory amino acids. 相似文献
109.
Lisbeth E. Gomez Pedro A.F. Lehmann 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1992,575(2)
A sensitive gas chromatographic method with flame ionization detection was developed for the analysis in plasma of the novel anticonvulsant d,l-3-hydroxy-3-ethyl-3-phenylpropionamide (HEPP), using d,l-2-hydroxy-2-ethyl-2-phenylacetamide as the internal standard. HEPP was extracted from alkalinized plasma into dichloromethane and quantified after derivatization with bis(trimethylsilyl)-trifluoroacetamide. Standard curves were linear from 0.5 to 50 and from 2 to 100 μg/ml of plasma, using 1.5 and 5 μg of the internal standard, respectively. The lower limit of detection at a signal-to-noise ratio of 3 standard deviations was 0.33 μg/ml of sample. The sensitivity, accuracy and reproducibility of the method were shown to be satisfactory for pharmacokinetic studies of HEPP. After intraperitoneal administration of 50 mg/kg to Wistar rats, the principal kinetic parameters were: absorption half-life = 0.04 h; volume of distribution = 1.32 l/kg; clearance = 4.40 ml/min; peak concentration = 50 μg/ml; peak time = 0.25 h; mean residence time = 4.55 h. 相似文献
110.
Visna virus is similar to the avian and the murine oncornaviruses. Oncornavirus replication is dependent upon the provirus being integrated into the host cell's DNA but integration and subsequent oncornavirus synthesis is blocked when the host cells are prevented from synthesizing cellular DNA or dividing. The synthesis of visna virus is restricted in vivo and may be dependent upon the host cell's ability to synthesize cellular DNA or divide. Treatment of sheep choroid plexus (SCP) cells with ultraviolet light or with mitomycin C prior to infection irreversibly inhibited plexus (ScP) cells with ultraviolet light or with mitomycin C prior to infection irreversibly inhibited both cell division and cellular nucleic acid synthesis but did not inhibit visna virus synthesis. Similarly, the synthesis of visna virus in cultures of SCP cells which had been prevented from dividing by being deprived of serum and in cultures of SCP cells which were incapable of synthesizing host cell nucleic acids by being treated with miracil D or sodium hexachloroiridate was equivalent to the synthesis of visna virus in cultures of SCP cells which were allowed to both synthesize cellular nucleic acids and divide. The synthesis of visna virus in the presence of ethidium bromide further demonstrated that integration of the visna provirus into the host cell's DNA is not required for visna virus synthesis to occur. 相似文献