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191.
The pattern of ontogenetic development of tryptophan (TP), tryptamine (T), indole-3-acetic acid (IAA), 5-hydroxytryptamine (5-HT; serotonin), and 5-hydroxyindole-3-acetic acid (5-HIAA) in the brains of rats aged 1-45 days is presented. Analysis of the five components in each brain allows the calculation of the acid/amine and amine/amino acid ratios. These metabolic indexes are a useful tool to study and compare the metabolic origins and fates of both amines. The ontogenetic patterns of TP, T, and IAA are very similar, especially during the first week postpartum. The highest and lowest levels found for T were 2.2 ng/g and 0.1 ng/g at the 1st and 5th day, respectively. The temporal relationship between the T/TP and IAA/T ratios suggests the existence of mechanisms protecting T against monoamine oxidase (MAO) which develop in parallel to synaptogenesis. Significant correlations were found between TP and IAA during the whole period studied and between TP and T during the first week after birth. The 5-HT peak found during the first postpartum week could be due to a non-neuronal pool of 5-HT protected against MAO and possibly contained in mast cells. Preliminary determinations on leptomeningeal membranes suggest the existence of such a pool. 相似文献
192.
193.
Twenty five cases of onychomycosis due to filamentous saprophytic agents were diagnosed within the period 1981–1982 in two mycology laboratories in Medellín, Colombia. These cases represented 4.5% and 9.5% respectively of the total fungal nail lesions (FNL) seen at those institutions. No explanation was found for the high frequencies, which sharply contrast with the previous local experience with the disease (0.4% of FNL). The responsible agents belonged to the following genera in decreasing order of frequency: Fusarium, Aspergillus, Scopulariopsis, Penicillium and Lasiodiplodia; two patients were infected with unidentified dematiaceous fungi and two more had the association of a saprophyte and a dermatophyte. In every case direct KOH preparations revealed septate hyphae, associated in 14 patients (56%) with chlamydoconidia. The only predisposing factors that were common to all these patients were age above 20 years and the use of footwear. 相似文献
194.
Summary Distribution of glycogen particles in semithin and ultrathin sections of biopsy samples from human muscles subjected to either short- or long-term running were investigated using PAS and Periodic Acid-ThioSemiCarbazide-Silver Proteinate (PA-TSC-SP) staining methods. Glycogen particles were predominantly found immediately under the sarcolemma or aligned along the myofibrillar Iband. After long-term exhaustive exercise type-1 fibers with a few or no glycogen particles in the core of the fibers were frequently observed. The subsarcolemmal glycogen stores of these depleted type-1 fibers were about three times as large as after exhaustive short-time exercise. Another indication of utilization of subsarcolemmal glycogen stores during anaerobic exercise was that many particles displayed a pale, rudimentary shape. This observation suggests fragmental metabolization of glycogen. Thus, depending on type of exercise and type of fiber differential and sequential glycogen utilization patterns can be observed. 相似文献
195.
Formation of protoplasts and their reversion were followed in 7 strains of brevibacteria. The formation of protoplasts and
their reversion differed both between various species of brevibacteria and between various mutant strains of the same species. 相似文献
196.
Jan Dahmén Torbjörn Frejd Göran Magnusson Ghazi Noori Anne-Sofie Carlström 《Carbohydrate research》1984,125(2):237-245
The applicability of 2-bromoethyl glycosides in carbohydrate synthesis is demonstrated by the synthesis of glycosides of alpha-L-Fuc-(1----2)-D-Gal and beta-D-Gal-(1----4)-D-GlcNAc. The bromoethyl aglycon was transformed into the methoxycarbonylethylthioethyl spacer, which allowed coupling of the sugars to proteins (BSA and KLH). 相似文献
197.
198.
Intergeneric hybrids of Saccharomyces cerevisiae and Zygosaccharomyces fermentati obtained by protoplast fusion 总被引:1,自引:0,他引:1
To obtain strains that are able to efficiently produce ethanol from different carbohydrates, mainly cellulose hydrolysates, several species of the genus Candida and a Zygosaccharomyces fermentati strain were examined for their ability to utilize cellobiose and produce ethanol, as well as for their thermotolerance and the possibility of genetic manipulation. Candida obtusa and Zygosaccharomyces fermentati tolerated the maximal temperature for growth, possessed the highest cellobiase activity, and offered the possibility of genetic manipulation, although neither of them proved to be a good producer of ethanol. Intergeneric hybrids of Saccharomyces cerevisiae and Z. fermentati were obtained after protoplast fusion. They were selected as prototrophic strains, after isolation of auxotrophic mutants from Z. fermentati and fusion with an S. cerevisiae strain which was also auxotrophic. The hybrids, which appeared at a frequency of 2 X 10(-7), presented characteristics of both parents, such as resistance to certain drugs and the ability to grow with either cellobiose or lactic acid as the sole carbon source; they were very stable, even under nonselective conditions. These hybrids may have important industrial applications as good fermenting strains. 相似文献
199.
Saxelin ML Nurmiaho-Lassila EL Meriläinen VT Forsén RI 《Applied and environmental microbiology》1986,52(4):771-777
"Viili," a fermented milk product, has a firm but viscous consistency. It is produced with traditional mesophilic mixed-strain starters, which have various stabilities in dairy practice. Thirteen morphologically different types of phages were found in 90 viili samples studied by electron microscopy. Ten of the phage types had isometric heads with long, noncontractile tails, two had elongated heads with long, noncontractile tails, and one had a unique, very long elongated head with a short tail. Further morphological differences were found in the tail size and in the presence or absence of a collar, a baseplate, and a tail fiber. To find hosts for the industrially significant phages, we examined the sensitivities of 500 bacterial isolates from starters of the viili. Seven of the phages attacked Streptococcus cremoris strains, three attacked S. lactis subsp. diacetylactis strains, and four attacked Leuconostoc cremoris strains. Some phages differed only in their host specificity. Hosts were not found for 4 of the 13 morphological types of phages. 相似文献
200.
Carmen Cascales Dan G. Craciunescu Paloma Martín-Sanz María Cascales 《Biological trace element research》1986,11(1):65-73
Enzyme activities and protein content were determined in the cytosolic and mitochondrial fractions of liver homogenates obtained from Rh(III) complex-, thioacetamide- and thioacetamide + Rh(III) complex-treated rats. The Rh(III) complex administered to nonthioacetamide-treated rats produced no significant changes either in the enzymatic activities assayed or in the protein concentration. The Rh(III) complex administered to thioacetamide-treated rats produced significant restoration of the following altered values: cytosolic and mitochondrial aspartate aminotransferase, glutamate dehydrogenase, NADP-isocitrate dehydrogenase, and protein concentration. However, a further increase was produced in the activities of glucose-6-phosphate dehydrogenase and malic enzyme. These increases can be interpreted in terms of an enhancement of the NADPH-dependent detoxifying processes and of nucleic acid synthesis and repair. 相似文献