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991.
Abstract. Degeneration of the archenteron in middle gastrulae occurred in the presence of α,α'-dipyridyl or Zn2+, inhibitors of prolyl hydroxylase. In the presence of these substances the archenteron degenerated and was eventually destroyed. Adding Fe2+ to the embryo culture containing α,α'-dipyridyl protected the archenteron from further degeneration, but the collapsed archenteron was not restored to the upright position. At the late gastrula stage, α,α'-dipyridyl did not cause the degeneration of the archenteron. Treatment of the embryos by α,α'-dipyridyl, starting at the swimming blastula stage, resulted in the production of many mesenchyme-like cells but archenteron was not produced in the embryos. Addition of Fe2+ to α,α'-dipyridyl culture, just before the beginning of gastrulation of normal embryos, resulted in the formation of normal archenteron. α,α'-Dipyridyl inhibited hydroxylation of proline residues of collagen in sea urchin embryos and Fe2+ prevented the inhibition by α,α'-dipyridyl. Respiration was not inhibited by α,α'-dipyridyl.  相似文献   
992.
993.
A group of captive chimpanzees, consisting of one adult male and three mother/infant pairs, was systematically observed over a 15-month period. Over 200 hr of data were collected, using both sequential and time sampling techniques, and compared to the available data on wild chimps. Unlike many captive groups, most behavior patterns were remarkably similar, both qualitatively and quantitatively, to that of wild chimpanzees including: play, grooming, infant sexual development, tool use, food sharing, prosocial partner preferences, and aggressive displays.  相似文献   
994.
A simple method is described for picomole determinations of fatty acid metal salts. Fatty acid salts are directly labeled with 4-bromomethyl-7-methoxycoumarin in the presence of excess ethylenediaminetetraacetic acid tripotassium salt without any solvent extractions. The fluorescence derivatives of fatty acids are separated by reverse-phase high-performance liquid chromatography followed by fluorometric detection. The response of each fatty acid (C8-C18) calcium salt is linear from 1 to 50 micrograms/ml of samples. The detection limit is about 7 pmol. Good recoveries are obtained for the calcium salts of myrystic acid and soap (C8-C18, C18:1,2). The new method is successfully applied to the study on biodegradation of fatty acids in river water.  相似文献   
995.
The production of L-lysine fromDL-α-amino-ε-caprolactam (DL-ACL) by new strains producingL-α-amino-ε-caprolactamase and aminocaprolactam racemase is described. Optimal conditions for hydrolysis ofL-ACL byCryptococcus sp. and for racemization of ACL by cells of a strain isolated in nature and identified asPseudomonas sp. were determined. Synthesis ofL-α-amino-ε-caprolactamase is induced byDL-ACL orL-lysine with the same effectivity. A positive effect of phosphates (potassium salts) on reduction of the induction lag was detected, the synthesis of this enzyme was found to be repressed by glucose and some possibilities of the reversion of this repressive effect were demonstrated. Under conditions optimal for the production of both enzymes a quantitative theoretical conversion of 10 % aqueousDL-ACL toL-lysine by a mixture of native cells in a mass ratio of 1: 2 (producer of ACL-hydrolase to producer of ACL-racemase) occurred in 8 h at 40 °C and pH 8.0  相似文献   
996.
Inflammatory reaction to ocular trauma is known to be related to prostaglandins. To further evaluate this phenomenon in human, PGE1 and E2 were measured by R.I.A. after silicic acid chromatography in aqueous humour of 26 patients before and 3 days after surgery for unilateral senile cataract (posterior chamber implant after extracapsular surgery). 13 out of these patients were treated with indomethacin by enteral route and 13 were not treated.PGE2 levels increased in all non-treated patients from : m < 214 pg/ml before surgery, to 2666 ± 869 pg/ml (range : 257 - 8728) p < 0.001 after surgery. PGE2 levels did not increase in indomethacin-treated patients. PGE1 levels did not increase significantly in non-treated as in treated patients.1) Intra-ocular surgery is followed in human by a constant increase of the only PGE2 in the aqueous humour. 2) Indomethacin inhibits this increase. 3) The post-surgical increase in the permeability of blood-aqueous barrier appears to be related to a release of PGE2.  相似文献   
997.
998.
999.
Enterotoxigenic reference strains of Staphylococcus aureus were cultivated in sterile whole and skim milk for 18 h at 37°G. Staphylococcal enterotoxin A, B, and C were detected directly in the milk by an enzyme linked immunosorbent assay (ELISA), sensitive down to 1 ng/ml. Enterotoxins in the range of 1 ng–20 µg/ml milk were detected without any concentration or extraction. Skim and whole milk were almost identical as medium for enterotoxin production.  相似文献   
1000.
A protein isolated from maize scutella which inhibits catalase in vitro has been shown to contain 12% carbohydrate in the form of galactose. This corresponds to four galactose molecules per inhibitor subunit. Removal of the carbohydrate with β-galactosidase or blockage with a galactose-specific lectin abolished activity of the inhibitor.  相似文献   
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