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71.
Blindness from conjunctivitis caused by Actinobacillus suis was found in a Canada goose (Branta canadensis) from a wildlife refuge in Kentucky. Lesions were not observed elsewhere and other body organs were grossly normal. Actinobacillus spp. in birds is rare and this is apparently the first report of conjunctivitis resulting from this infection in waterfowl. 相似文献
72.
Beta-adrenergic agonists and cyclic AMP decrease intracellular resting free-calcium concentration in ileum smooth muscle 总被引:2,自引:0,他引:2
I Parker Y Ito H Kuriyama R Miledi 《Proceedings of the Royal Society of London. Series B, Containing papers of a Biological character. Royal Society (Great Britain)》1987,230(1259):207-214
Intracellular free-calcium levels were measured in strips of longitudinal smooth muscle from guinea-pig ileum; fura-2 was used as a calcium monitor. At rest the calcium concentration was about 180 nM, and this rose to 300-400 nM following electrical stimulation and during spontaneous calcium transients (all measurements at 23-25 degrees C). Isoprenaline suppressed the spontaneous calcium transients, and reduced the resting calcium level to about 130 nM. This fall in resting calcium concentration was seen even in muscle strips which did not have spontaneous activity. Elevation of intracellular cyclic AMP levels, produced by forskolin or dibutyryl cyclic AMP, mimicked the actions of isoprenaline. We conclude that the relaxant effects of beta-adrenergic agonists of visceral smooth muscle may be explained partly by a fall in intracellular resting free-calcium level, mediated via an increase in cyclic AMP. 相似文献
73.
Additive and independent responses in a single receptor: aspartate and maltose stimuli on the tar protein 总被引:12,自引:0,他引:12
The aspartate and maltose responses of E. coli are mediated through a single membrane receptor, yet the responses are independent and additive. Both stimuli cause methylation of the same 4 glutamic acid residues. More extensive methylation occurs when a cell that has adapted to one stimulus is exposed to the second, or when both stimuli are added simultaneously. The degree of methylation, as well as receptor migration on two-dimensional gels, demonstrates that only one type of protein is involved, rather than two different receptors arising from differential processing of a single gene. A conformational "push-pull" mechanism in which binding of stimulus and covalent modification, producing opposing stresses, can explain these diverse results. 相似文献
74.
P Fioretti F Fruzzetti C Ricci C Vettori A Sardi L Musatti T Gargiulo G B Melis 《Prostaglandins》1987,34(6):927-937
The effectiveness and acceptability of Alfaprostol (an analog of PGF2 alpha) in inducing labor were assessed in 20 pregnant women at term. All subjects had no spontaneous uterine activity before treatment and the mean (M +/- SE) Bishop score was 2.45 +/- 0.21. The drug was administered by vaginal route at the dose of 10 mg every 3 hours. Regular uterine contractions appeared in all patients and delivery occurred in 85% of the patients after a mean time of 9h50min +/- 0h55min following the start of treatment. The mean dose of Alfaprostol utilized to achieve delivery was 29.4 +/- 2.0 mg. No major side effects were noted in the mothers and their fetuses at any time during treatment. Two patients exhibited vomiting. The Apgar score of all newborns at birth was 8 or more. These results suggest the usefulness of Alfaprostol to induce labor in pregnant women at term, as it has oxytocic activity without adverse effects on either the mother or the fetus. 相似文献
75.
The stabilizing effect of Ca2+ (264.9 mg CaCl2 X 2H2O ml-1) on a 0.5% solution of twice-crystallized bovine trypsin in phosphate-buffered saline (used for harvesting human embryonic lung fibroblasts) was studied at 7-37 degrees C and at -20 and -70 degrees C. It can be concluded that storage of the enzyme in the buffer (with or without Ca2+) is not advisable at temperatures greater than or equal to 20 degrees C. At 7 degrees C, on the other hand, trypsin can be stored for some weeks in the calcium-containing phosphate-buffered saline if a moderate loss of activity is acceptable. At -20 degrees C and -70 degrees C the stability of the enzyme was good. In the presence of Ca2+ about 90% of the activity remained after 18 weeks. Without Ca2+ the activity was approximately 10% lower. 相似文献
76.
77.
D S Herson B McGonigle M A Payer K H Baker 《Applied and environmental microbiology》1987,53(5):1178-1180
Enterobacter cloacae attached to drinking water distribution particles was subjected to chlorination. Attachment resulted in the protection of these organisms from disinfection. This effect was found to be dependent upon both the level of chlorine in the system and attachment time. The results obtained in this study indicate that attached organisms may play an important role in coliform outbreaks. 相似文献
78.
King Frederick D.; Cucci Terry L.; Townsend David W. 《Journal of plankton research》1987,9(2):277-289
Ammonium regeneration by micro- (35153 µm) andmacrozooplankton (> 153 µm) was determined in the Gulfof Maine by measuring the activity of the excretory enzyme glutamatedehydrogenase (GDH) in various size fractions. GDH maxima weregenerally observed to correspond to the depth of the chlorophyllmaximum as previously reported in the Gulf of Mexico and inthe vicinity of the Nantucket Shoals. GDH activity of the microzooplanktonwas considerably lower than the macrazooplankton, suggestingthe microzooplankton made only a minor contribution (111%) to the total ammonium regenerated. These results were confirmedby biomass estimates made from counts of individual species.Ammonium excretion by both zooplankton fractions was estimatedto supply 531 % of the nitrogen requirements for primaryproduction, with an estimated 5963% supplied by the verticaltransport of nitrate (new nitrogen) into the euphoric zone. 相似文献
79.
A new species of copepod belonging to the family Aetideidae,Bradyidius slyliformis sp. nov. is described and figured. Therelationship of this species to the other 12 members of thegenus is discussed.
1Present address: 121 Jalan Athinahapan Dua, Taman Tun Dr Ismail,60000 Kuala Lumpur, Malaysia 相似文献
80.
Summary The endoglucanase component (CMCase I) ofPenicillium
funiculosum cellulase was purified to apparent homogeneity by ultrafiltration and gel chromatography. It consists of a single polypeptide chain with a molecular weight of 56000 and is a glycoprotein. Viscometric and end-product analysis revealed the randomness of enzyme action. Multifunctional characteristic of CMCase I was studied with various carbohydrate substrates.NCL Communication No.: 4307 相似文献