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991.
Highly purified native parathyroid hormone was iodinated by the enzymatic method and separated from unlabeled hormone by isocratic HPLC. The separation system used also resolved iodohistidine, monoiodotyrosine, and diiodotyrosine forms of the hormone from one another. A simplified procedure for direct bioassay of the carrier-free, high specific activity, mono- and diiodinated parathyroid hormone (PTH) by the renal membrane adenylyl cyclase method was also developed. Both labeled forms of the hormone are very potent in this assay, but the iodinated forms appeared to give a lower Vmax than the native hormone. The methods for iodination, separation and biological characterization of this PTH tracer are exceptionally facile, inexpensive, and convenient.  相似文献   
992.
993.
A possible vivo role of pyridine nucleotides and their oxidized/reduced ratio on the regulation of inositol biosynthesis in Neurospora crassa was studied.A direct correlation was obtained when the values of of the water-soluble free inositol pool from intact N. crassa mycelia were plotted agains their NAD+/NADH or NAD+ + NADP+/NADH + NADPH ratios. Higher values in this inositol pool coincided with higher values in the chosen ratios.In long-term experiments (48 h), where the mold was grown without shaking, lower values for the inositol pool, the in vitro activity of D-glucose-6-phosphate cycloaldolase (glucocycloaldolase) and the myo-inositol (inositol) in phospholipids were found than those for cells grown with vigorous shaking.In short-time experiements (20 min), using N. crassa cells depleted of endogenous substrates, the in vivo synthesis of inositol was higher in cells incubated with vigorous shaking than in cells incubated without shaking. Nevertheless, in these experiments the in vitro activity of glucocycloaldolase was not affected by the earation conditions.  相似文献   
994.
The growth of a bradytrophic mutant isolated from the methanol-utilizing yeast Hansenula polymorpha was found to be stimulated by both tyrosine and phenylalanine. The mutant contained about half as much chorismate mutase activity as the wild-type strain. When grown in a medium containing 2% mehtanol as the major carbon and energy source, the bradytroph excreted a low but significant level (28 mg/liter) of L-tryptophan.  相似文献   
995.
Young men with uncomplicated gonococcal urethritis were treated with 1 gram of cefonicid given intramuscularly plus 1 gram of probenecid by mouth. Of 53 evaluable patients, 33 (62%) had penicillinase-producing Neisseria gonorrhoeae. All but one of these patients were cured. All men who had penicillin-sensitive infections were cured. Cefonicid was highly effective in the treatment of both penicillin-sensitive and penicillin-resistant N gonorrhoeae. Other than moderate pain at the site of injection, there were no adverse side effects. Cefonicid can be added to the group of newer cephalosporins that are effective in the treatment of gonococcal urethritis caused by either penicillin-sensitive or penicillin-resistant strains.  相似文献   
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999.
Quantification of deoxynucleosides using micellar high-performance capillary electrophoresis (HPCE) is an efficient, fast and inexpensive evaluation method of genomic DNA methylation. This approach has been demonstrated to be more sensitive and specific than other methods for the quantification of DNA methylation content. However, effective detection and quantification of 5-methyl-2′-deoxycytidine depend of the sample characteristics. Previous works have revealed that in most woody species, the quality and quantity of RNA-free DNA extracted that is suitable for analysis by means of HPCE varies among species of the same gender, among tissues taken from the same tree, and vary in the same tissue depending on the different seasons of the year. The aim of this work is to establish a quantification method of genomic DNA methylation that lends itself to use in different Castanea sativa Mill. materials, and in other angiosperm and gymnosperm woody species. Using a DNA extraction kit based in silica membrane has increased the resolutive capacity of the method. Under these conditions, it can be analyzed different organs or tissues of angiosperms and gymnosperms, regardless of their state of development. We emphasized the importance of samples free of nucleosides, although, in the contrary case, the method ensures the effective separation of deoxynucleosides and identification of 5-methyl-2′-deoxycytidine.  相似文献   
1000.
The Revillagigedo Archipelago National Park is the largest no-take Marine Protected Area in North America and it is essential for the conservation of globally endangered marine megafauna, including cetaceans, sea birds and cartilaginous fishes. The present paper reports the occurrence of 28 chondrichthyan species, including 19 sharks, seven batoids and two chimaeras in the Revillagigedo Archipelago, comprising eight new records and a brief revision of confirmed species to date.  相似文献   
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