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Electron microscopic observations on the adrenal cortex 总被引:4,自引:0,他引:4
LEVER JD 《The American journal of anatomy》1955,97(3):409-429
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A strain of food-poisoning bacterium has been isolated by Jin Jiexiang (1963) in China from the fermented cornflour that has gone bad. These pathogenic microorganism has been identified and named Pseudomonas by Zhao Naixin in 1988, which is the same species as P. cocovenenans. The characteristics of them were conformed to these of the species P. cepacia of section 2 of the genus Pseudomonas. In view of the fact that the fine structures of the above mentioned three strains of Pseudomonas have not been described yet, we decided to observe them with electron microscope. Results indicate there are many things in common among the three strains, such as: appearing short rods, 0.6-0.8 microns in diameter by 1.5-2.0 microns in length, one polar multiflagella; non-pili, non-capsules, non-endospores; containing intranuclear inclusions (electron-dense bodies or concentric laminae bodies), accumulating intracytoplasmic PHB granules; forming filaments, minicells and bizarrecells; producing extracellular cellulose-like materials by the three strains have not been reported previously. 相似文献
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Three strains of B. thetaiotaomicron have been isolated from caeca of BALB/c-nu/+ mice of SPF. These Bacteroides are obligately anaerobic, Gram-negative, non-spore-forming and non-motil without flagella rods. A characteristic of staining is deep at ends and stainless at the medium of a rod. The isolation and identification of these strains has been reported in 1987. This paper introduced only the results of EM observations. Under the SEM, the unstained area of rods is always showing a concavity, which is just a nucleoid in sections under the TEM. Many lamellar corpuscles have been found in cell plasma. Some of them have been secreted out of the cells. The chemical properties and physiological functions of them are unknown. 相似文献
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Rescue of the corpus luteum from its programmed senescence maintains progesterone production required for pregnancy. In primates, chorionic gonadotropin produced by the developing conceptus acts as the primary luteotrophic signal. The purpose of this research was to assess corpus luteum rescue by examining changes in daily urinary progesterone metabolite levels during the first week after implantation. We determined the variability in progesterone metabolite profiles and evaluated its relationship to early pregnancy loss in 120 naturally conceived human pregnancies, including 43 early pregnancy losses. In other primates, an abrupt increase in the progesterone metabolite occurs at the time of implantation. This pattern occurred in an estimated 45% of the pregnancies in the present study. In the remaining pregnancies, there was a delayed rise (18%), neither a rise or decline (22%), or a decline (15%) during the week after implantation. The estimated rate of early pregnancy loss increased across these categories (from 5% loss with an abrupt rise at implantation to 100% loss with progesterone metabolite decline). Low urinary hCG levels in early pregnancy were significant determinants of a decline in postimplantation progesterone metabolite. However, preimplantation steroid metabolite levels were not significant, suggesting no inherent problem with the corpus luteum. Examination of individual progesterone metabolite profiles in relation to hCG profiles also indicated that few losses were caused by corpus luteum failure. Delineating the functional importance of an abrupt progesterone rise at the time of implantation may provide new strategies for promoting successful implantation in assisted reproduction. 相似文献
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Corpora lutea were obtained surgically from fifteen mature Angus crossbred cows representing three experimental groups of five cows each. Cows in Group A were 180 days of gestation, cows in Group B had recently experienced parturition (=24 hours) and cows in Group C had recently exhibited standing estrus (=24 hours). Samples of corpora lutea were fixed in 10% buffered formalin and prepared for light microscopy and 2.5% glutaraldehyde and processed for electron microscopy. Luteal cells from cows in Group A were of two distinct types, large cell and small cell types. The large luteal cells of both Groups A and B were similar, with one exception. Those from cows in Group B stained less intensely and the nuclear chromatin appeared less pronounced and marginated. Small luteal cells were not readily observed in corpora lutea from Group B. In addition, there was evidence of pyknosis, karyorrhexis and mononuclear cell infiltration in corpora lutea from Group B. Luteal cells from cows in Group C were characterized by atrophy of the nucleus and vacuolation of the cytoplasm. Vascular changes consisted of endothelial cell necrosis and pyknosis of cells of the tunica media of arteries within the corpus luteum. Ultrastructurally, there were distinct differences in all groups with respect to the size and quantity of lipid droplets, the presence of electron lucent vesicles in the cytoplasm and indentations of the nuclear membrane of luteal cells. The results of this study suggest that at the time of parturition in the cow luteolysis may involve primarily small luteal cells, and that the corpus luteum may be a source of progesterone, which is likely a function of the large luteal cells. 相似文献
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The role of electron transport in progesterone biosynthesis was investigated in bovine corpus luteum homogenate. Although amytal and malonate inhibited progesterone synthesis, rotenone under several different incubation conditions was without effect. On the basis of differences in the effects of amytal and rotenone it is suggested that for the side-chain cleavage of cholesterol, although formation of some high energy intermediate of oxidative phosphorylation is obligatory, the electron shuttle between NAD and flavin is not. 相似文献
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Electron microscopic observations of Pseudomonas aeruginosa 总被引:2,自引:0,他引:2
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《Reproductive biology》2014,14(2):110-114
The aim of this article was to present the extent to which the state-of-the art ultrasonographic imaging can be used to visualize the features of the human corpus luteum (CL). In the late 1970s, the first ultrasonographic images of human CLs were published. The advent of transvaginal, high-resolution transducers has greatly improved the quality of imaging as did the subsequent introduction of color Doppler and 3D ultrasonography. In the present technical note, the examples of the various technical and imaging modalities used to examine the human CLs are shown. CL is a short-lived structure with a highly variable morphological appearance and the 3D ultrasonographic technique is an ideal tool to perform standardized measurements on the CL. The introduction of new imaging techniques in clinical reproductive medicine can only be successful if operators are properly trained. 相似文献
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Quantitative light microscopic analysis of corpus luteum growth during pseudopregnancy in the rabbit
A M Dharmarajan C Mastroyannis Y Yoshimura S J Atlas E E Wallach B R Zirkin 《Biology of reproduction》1988,38(4):863-870
We employed stereological methods at the light-microscope level to examine the mechanism by which corpora lutea (CL) grow during the course of pseudopregnancy in the rabbit. Corpus luteum volume per ovary, the absolute volume of luteal cells per CL, individual luteal cell volume, the number of luteal and endothelial cells per CL, and capillary surface area per CL were examined in rabbits at Days 1, 4, 7, 11, and 18 of pseudopregnancy. Total CL volume increased from 3.7 +/- 0.1 microliter to 30.3 +/- 0.5 microliter over Days 1 to 11 and thereafter decreased to 15.2 +/- 1.1 microliter by Day 18. Stereological analyses showed that the increases in CL volume from Day 1 to Day 11 were due primarily to increases in the volume of individual luteal cells (from 2.6 +/- 0.2 pl on Day 1 to 23.5 +/- 1.7 pl on Day 11, 1 pl = (10 mu)3; r = 0.96), and that the decrease in CL volume after Day 11 resulted largely from a decrease in luteal cell volume (to 12.8 +/- 1.5 pl). In contrast, no change was seen in the number of luteal cells per CL (range 9.1 x 10(5)-12.5 x 10(5)). These data show that CL growth and subsequent regression during pseudopregnancy result primarily from changes in the volume of individual luteal cells, and not from changes in the number of luteal cells. These data support the hypothesis that modulation of progesterone production during pseudopregnancy is due to changes in individual luteal cell volume and not to changes in cell number. 相似文献