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1.
With the help of a new synthetic material follicles and corpora lutea from the ovaries of 80 cows in different stages of the sexual cycle were examined for modifications of their blood vessel architecture. In the theca externa the main artery which runs towards the follicle, separates into arterioles of which capillaries derive in the theca interna, building a basket-like network around the zona granulosa. After ovulation the follicle wall forms characteristic fields. Capillaries grow into the zona granulosa and thus the folds form the lobular structure of the corpus luteum. Capillaries which rise from the ruptured part of the follicle, spread centripetally and together with lutein cells they build up the not lobulated cupola of the corpus luteum. The regression of the corpus luteum starts around the 16th day of the cycle, beginning at the capillary network of the cupola. A contraction of the vessels and a quick decrease of the volume follow.  相似文献   
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The expression pattern of the intermediate filament protein cytokeratin 18 (CK 18) is described during pre- and post-natal development of the porcine lung using a monoclonal antibody against human CK 18. Lungs from 16 foetuses in pseudoglandular, canalicular, saccular and alveolar stages of lung development and lungs from 12 pigs ranging in age from birth to 49 days after birth were studied by immunohistochemistry.In the early pseudoglandular stage of development (day 70 of gestation) all the columnar epithelial cells lining the tubular endbuds strongly expressed CK 18 predominantly in the apical cell compartment. A modest staining was found in the more cuboidal cells of the canalicular stage (day 80 of gestation) where the labelling occurred as a distinct positive rim at the apical cell membrane in most of the cells lining the canaliculi. In 96- and 100-day-old foetuses, parts of the gas exchanging area were formed as terminal sacs by extreme attenuation of the epithelium. In this stage, CK 18 was clearly detectable in the flat type I as well as in the cuboidal type II alveolar epithelial cells. A marked change of the CK 18 expression pattern occurred during formation of the alveoli by septal outgrowth and maturation of the epithelium in 105- and 111-day-old foetuses. Differentiated type I cells no longer expressed CK 18, whereas type II cells were still labelled. Moreover, a specific change in the subcellular distribution pattern from the luminal periphery in immature porcine type II cells to a cytoplasmic localization in differentiated type II cells could be observed. Our investigation additionally demonstrated that the epithelium of bronchi, bronchioli and terminal bronchioli expressed CK 18 in all pre- and post-natal developmental stages. From the 96 days of gestation onwards the epithelial cells of developing bronchial glands were also labelled. Our results clearly show that during porcine lung development profound changes in the cellular expression pattern of CK 18 occur and that CK 18 can be regarded as a selective marker for differentiated porcine alveolar type II cells from the 105th day of gestation onwards. We also assume that the intermediate filament CK 18 could be of significance in the maturation process of the type II alveolar cells.  相似文献   
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ABSTRACT Despite the fact that nonemployment income makes up approximately one-third of all personal income, its impact on local area economies has not been closely examined. This study uses Michigan county data to examine the impact of nonemployment income on nonbasic income over a twenty-seven-year period. This impact is compared to the impact of basic income by employing regression analysis to estimate comparative multiplier effects for both types of income. Nonemployment income is found to have a significant impact on nonbasic income, particularly in metropolitan and nonmetropolitan urban counties, where its impact appears to be stronger than that of basic income.  相似文献   
7.
Laser-cooled 9Be+ ions confined in two-dimensionally extended lattice planes were directly observed, and the images were used to characterize the structural phases of the ions. Five different stable crystalline phases were observed, and the energetically favored structure could be sensitively tuned by changing the areal density of the confined ions. The experimental results are in good agreement with theoretical predictions for the planar (infinite in two dimensions) one-component plasma. Qualitatively similar structural phase transitions occur, or are predicted to occur, in other experimentally realizable planar systems.  相似文献   
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Connexin43 (Cx43) is a major protein of myometrial gap junctions. The number of Cx43 gap junctions increase dramatically with the onset of labour in association with development of synchronized uterine contractions. The formation of myometrial gap junctions follows an increase in the oestrogen to progesterone ratio indicating an important role of steroid hormones in regulating Cx43 expression at term. However, no relationship has been established between the expression of Cx43 in the non‐pregnant myometrium and concentration of steroid hormones during the oestrous cycle. Here, we used immunofluorescence and Western blotting to analyse the expression of Cx43 gap junctions in the myometrium of pre‐pubertal pigs (n = 7) and mature pigs at pre‐ovulatory (n = 7), luteal (n = 5) and late luteal (n = 3) stages of the oestrous cycle. The number of Cx43 gap junctions calculated per 1 mm2 of the myometrial section was low in pre‐pubertal pigs and significantly higher (p < 0.022) in pre‐ovulatory animals. In relation to pre‐ovulatory animals the number of myometrial gap junctions was significantly lower (p < 0.019) at the luteal phase and correlated with significantly higher (p < 0.005) concentration of endogenous progesterone. Phosphorylated isoforms of Cx43 protein were expressed in the myometrium of pre‐pubertal pigs and mature animals at pre‐ovulatory and late luteal phases, while they were down regulated at the luteal stage. These results indicate that changes of Cx43 expression in the porcine myometrium during the oestrous cycle may be regulated by progesterone concentration and may contribute to the modulation of uterine motility.  相似文献   
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Squamous metaplasia of the oviduct epithelium is a rare disorder of reproductive organs. We noted squamous metaplasia of the oviduct epithelium in a sow routinely slaughtered at day 2 of the oestrous cycle. Expression of transforming growth factor beta3 (TGF beta3) in the metaplastic epithelia was evaluated by immunohistochemistry, because TGF beta3 appears to play a key role as regulator of a variety of tissue remodelling events. Our results show that TGF beta3 immunostaining was specifically localized to foci of squamous metaplasia of the epithelial linings. Non‐metaplastic epithelial cells of the oviduct were not immunostained with anti‐TGF beta3 antibody. At the subcellular level, TGF beta3‐labelled cells occasionally showed signs of apoptotic cell death. It is concluded that signals produced by TGF beta3 in metaplastic lesions of the oviduct are potentially involved in pathophysiological processes.  相似文献   
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Very virulent Marek's disease viruses (vvMDV), defined as isolates against which the herpesvirus of turkey (HVT) vaccine provide poor protection, have been isolated from poultry flocks in both the United States and Europe. Twenty-one samples from vaccinated Australian flocks, experiencing problems with excessive Marek's disease (MD), were tested for the presence of transmissible MD viruses (MDV). Of the 16 samples which contained a transmissible agent, 14 were pathogenic in chickens, based on the development of MD lesions or depression of the bursa/body weight ratio. Of the pathogenic isolates which have been successfully typed 10 were serotype 1, and one was serotype 2 MDV. Pathogenicity of isolates varied. Several isolates caused tumours in 20-30% of both vaccinated and unvaccinated chickens. Two isolates, MPF6 and MPF23, caused tumours in more than 50% of chickens. When MPF6 and MPF23 were tested in vaccine trials bivalent vaccine gave no better protection against development of MD lesions than a monovalent vaccine. Isolate MPF23 was so pathogenic that lesions were produced in all chickens, regardless of the vaccine protocol used. Therefore vvMDV have been isolated in Australia, and unlike the vaccines tested overseas, bivalent Australian vaccines do not appear to provide greater protection against these vvMDV.  相似文献   
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