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101.
López-Gatius F 《Theriogenology》1989,32(2):185-195
Two consecutive experiments were conducted. In Experiment 1, 24 Friesian lactating cows were randomly assigned to two groups. Cows in Group I received intramuscularly (i.m.) 500 mcg of cloprostenol, 1250 IU of human chorionic gonadotropin (hCG) and 5 mg of estradiol benzoate 12 h after cloprostenol treatment. Cows in Group II received 750 IU i.m. of hCG and 3 mg of estradiol benzoate 12 h after cloprostenol treatment. Treatment was given on Day 16 after estrus in both groups. All animals showed estrus within 24 to 48 h after cloprostenol treatment. The average interval from cloprostenol injection to the onset of estrus was not influenced by treatments. Four cows in Group I failed to ovulate and became cystic. In Experiment 2, 71 Friesian lactating cows were randomly assigned to two groups. Cows in Group I received 500 mcg i.m. of cloprostenol after corpus luteum detection by palpation per rectum. Cows in Group II received 500 mcg of cloprostenol plus 750 IU of hCG and 3 mg of estradiol benzoate 12 h after. When estrus ready for service was confirmed by rectal examination, cows were inseminated. The percentage of cows ready for service tended to be lower (P < 0.06) between cows in Group I (88%) and those in Group II (100%). The average interval from cloprostenol treatment to service was longest (P < 0.001) in Group I (78.7 h +/- 14.9, X +/- SD) vs Group II (48 h +/- 2.9). The degree of readiness for service synchrony was lowest (P < 0.001) in Group I (59.3%) vs Group II (94.2%). The pregnancy rates of cows synchronized or treated were not altered by hCG-estradiol benzoate treatment (P > 0.25). These results suggest that in dairy cows treated with cloprostenol following palpation per rectum of a corpus luteum and then with 750 IU of hCG and 3 mg of estradiol benzoate 12 h later, a single fixed-time insemination at 48 h after cloprostenol treatment should be performed. 相似文献
102.
G Csaba P Kovács V László 《Cellular and molecular biology, including cyto-enzymology》1989,35(5):511-514
Tetrahymena cells treated with insulin in mass cultures were separated to single-cell clones or one of the "sister-cells" of dividing Tetrahymena (in single-cell culture) was treated with insulin. In both cases the FITC-insulin binding of sister-cells were compared. The insulin imprinting significantly increased the insulin binding of cells. There was also a significant difference between the imprinted and not imprinted sisters as well as between the not imprinted sisters. This demonstrates the existence of a difference (in hormone binding) between sister-cells and justifies that the information of the first hormone treatment (imprinting) is not equally divided between the sister-cells. 相似文献
103.
104.
Fixed bacteria of the protein A-rich Cowan I Staphylococcus strain were labelled with fluorescein isothiocyanate and used as the second-step reagent in an indirect immunofluorescent assay of specific cell-surface antigen expression. The results are documented with fluorescence microscopy and flow cytometry. 相似文献
105.
The interaction between the Ca2+ transport ATPase and the proteolipid of rabbit sarcoplasmic reticulum was analyzed by fluorescence energy transfer, using the following donor: acceptor combinations: Ca2(+)-ATPase tryptophan----IAEDANS-proteolipid; IAEDANS-ATPase----IAF-proteolipid; IAEDANS-proteolipid----IAF-ATPase. The observed energy transfer may indicate weak interaction between the Ca2(+)-ATPase and proteolipid, but collisional energy transfer definitely contributes. The energy transfer was abolished by deoxycholate or sodium dodecylsulfate at concentrations sufficient to solubilize the membrane. In view of the low proteolipid content of sarcoplasmic reticulum and the weak interaction suggested by the energy transfer, at best only a small fraction of ATPase molecules could exist in the form of ATPase-proteolipid complexes. 相似文献
106.
The freshwater snail L. stagnalis is known to be able to respond to a strong, noxious stimulus with a full retraction of the foot and head into the shell accompanied with expelling the blood through the hemal pore. We have found that this behavioural response, besides graded local retractions, can be triggered by mild tactile stimulation provided that the stimulus is repeated several times. Only a complete exsanguination could be obtained, indicating that it is an all-or-none defensive behaviour. In an electrophysiological investigation of isolated brain, a number of similarities were found between this all-or-none behaviour and the so-called input 3 to central neurons, as described by Benjamin and Winlow. These include ability to be selectively activated by high calcium solutions, and blocked by keeping the snails in a spoiled water. Injection of snails with naloxone (0.5-2.0/micrograms/g) or ergotamine (0.4/microgram/g) blocked selectively the whole body withdrawal induced by tactile stimulation, but not that induced by injection of a high calcium saline or acetylcholine solution, indicating that enkephalinergic and/or dopaminergic mechanosensory neurons might be involved. The consideration of available data has led to a working hypothesis that the activity of input 3 might be the neurophysiological correlate of the high threshold all-or-none whole body withdrawal associated with exsanguination. 相似文献
107.
Mean square optical anisotropies and molar Kerr constants were calculated for homopolypeptides of the 20 natural amino acids and of several enzymes and proteins in the random-coil state. The effect of hydration was taken into account in constructing the molecular potential that gives the conformational energies as a function of the rotational angles phi and psi of the backbone and chi(1) of the side chain. The Rotational Isomeric State model was used in calculated energies, the Valence Optical Scheme and the matrix calculus technique of Flory being employed in the evaluation of the optical properties. The results are compared with calculations for the same substances that were performed without taking into account the solvent, as well as with other similar studies. The Kerr constant is confirmed as being one of the most sensitive properties of a given polypeptide to the residue class and to the sequence of those residues. 相似文献
108.
Effect of streptozotocin-diabetes on rat liver mitochondrial adenosine triphosphatase turnover. 总被引:1,自引:0,他引:1 下载免费PDF全文
The apparent turnover rates of some mitochondrial enzymes can be modified in diabetes. We studied the effect of streptozotocin-diabetes on the half-life of a protein tightly bound to the inner membrane, ATPase. The half-life (t 1/2), measured by the double-isotope technique, decreased by approx. 20% in diabetes (from approximately equal to 2.56 days in controls to approximately equal to 2.06 days in diabetic rats). These results suggest that diabetes produces an increase in degradation of ATPase by a mechanism which is not yet clear, possibly influenced by alterations induced by diabetes in hepatic lysosomes that are associated with hepatic autophagy. 相似文献
109.
The molecular ordering of molecules embedded in a uniaxial liquid crystalline system has been considered. In particular, planar Chl a molecules in an MBBA + EBBA mixture have been studied by using polarized resonance Raman spectroscopy. The second- and fourth-rank order parameters and the orientational distribution function of Chl a in the nematic MBBA + EBBA liquid crystalline phase are discussed. 相似文献
110.
Summary A 12-year-old boy is described with multiple anomalies and a de novo terminal deletion of 17p13. Based on clinical examination, the Miller-Dieker syndrome was diagnosed. 相似文献