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Histological, histochemical, and electron microscopic studies of tissues of the fundus oculi in 111 eyes with senile maculopathy revealed amyloid in the nodules. Bruch's membrane, and between the basal membrane of retinal pigmented epithelium and the internal collagen layer of Bruch's membrane in the center of the fundus oculi. The detected amyloid incorporations are referred to senile amyloidosis and reliably differ from amyloid in generalized amyloidosis. Comparative analysis of morphologic changes in tissues of the macular and paramacular areas of the fundus oculi and of the incidence of amyloid incorporations in them permit us to propose that accumulation of local senile amyloid is conductive to development and aggravation of senile maculopathy. A relationship between the degree of pigmented epithelium degeneration and accumulation of amyloid in the fundus oculi was revealed. The authors put forward a hypothesis of the pathogenesis of some stages of senile maculopathy, in which the principal role in the formation and deposition of abnormal protein, amyloid, is played by degenerative cells of pigmented epithelium. It is followed by amyloid destruction of Bruch's membrane and accumulation of amyloid under it and the basal membrane of pigmented epithelium. this in its turn, promoting neovascularization and formation of fibrovascular membrane. 相似文献
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A 4-year-old boy presented with sudden onset of fever, pyuria, and bacteriuria. Ultrasound revealed left hydronephrosis and hydroureter. A plain abdominal radiography and excretory urogram showed a giant ureteral stone measuring 9 cm causing ureteral obstruction. Underlying anatomic or metabolic abnormalities were not detected. Extraction of the stone resulted in complete disappearance of the hydronephrosis and hydroureter. 相似文献
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Curschmann's spirals have been observed for more than 100 yr in the sputum of patients affected by lung cancer, asthma, chronic bronchitis, or in asymptomatic smokers. However, to date, their clinical significance and pathogenesis have not been completely explained. Curschmann's spirals in the sputum of two populations were studied: 164 traffic policemen of Rome and 119 subjects living in a rural district near Perugia. Of these two groups, only the first were exposed daily to urban environmental pollutions. Spirals were detected in the sputum of 29 traffic policemen and in 3 subjects from the group not exposed daily to urban environmental pollutants. Between these two groups of subjects the difference was statistically significant (P < 0.001). Therefore, daily exposure to urban atmospheric pollution may play a role in the production of Curschmann's spirals. Our two groups were also divided into smokers and nonsmokers to evaluate if cigarette smoking could influence the presence of spirals in sputum. Our study confirms the association of spirals in the sputum of smokers but also indicates their presence in individuals who never smoked but were exposed to environmental pollutants. We also noticed that exposure to pollution and cigarette smoking may have a synergistic effect on the formation of spirals in the respiratory tract. 相似文献
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K Lilliendahl 《Canadian Metallurgical Quarterly》1998,55(5):1335-1340
According to predictions from theoretical models, body mass and the daily foraging pattern of small birds in winter should be sensitive to predation risk. With increased risk of predation birds are expected to lower their body mass and shift their foraging to the afternoons. I studied the effect of predator presence on daily mass gain in captive yellowhammers, Emberiza citrinella. The birds were tested in unisex pairs, one bird being dominant over the other. In the first treatment the amount of food was restricted, and the daily pattern of mass gain was recorded. The second treatment was identical to the first, but, in addition, a stuffed sparrowhawk, Accipiter nisus, was displayed to the birds in the morning. Contrary to predictions from some theoretical models and other studies, the birds gained weight on days when the hawk was shown. Furthermore, the increased foraging happened mainly in the first half of the day, which also contradicts predictions from models. These results could be explained as a response to interrupted foraging, decreasing the probability of the birds acquiring the critical evening body mass. Alternatively, the birds increased their body reserves in preparation to leave a dangerous situation. Both dominance classes showed a similar response. The results suggest that the effects of predators on foraging interruptions should be included in models of daily routines of reserve accumulation. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour. 相似文献
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The interaction of infrared light with the human ocular fundus, particularly sub-retinal structures, was studied in vivo. Visible and infra-red wavelengths and a scanning laser ophthalmoscope were used to acquire digital images of the human fundus. The contrast and reflectance of selected retinal and sub-retinal features were computed for a series of wavelengths or modes of imaging. Near infrared light provides better visibility than visible light for sub-retinal features. Sub-retinal deposits appear light and thickened; the optic nerve head, retinal vessels, and choroidal vessels appear dark. Contrast and visibility of features increases with increasing wavelength from 795 to 895 nm. Optimizing the mode of imaging improves the visibility of some structures. This new quantitative basis for near infrared imaging techniques can be applied to a wide range of imaging modalities for the study of pathophysiology and treatment in diseases affecting the retinal pigment epithelium and Bruch's membrane, such as age-related macular degeneration. 相似文献
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RA Lefebvre 《Canadian Metallurgical Quarterly》1997,339(2-3):201-209
Cefoperazone amphotericin teicoplanin (CAT) agar was developed from cefoperazone deoxycholate (mCCD) agar by modification of the selective antibiotics in order to permit growth of strains of Campylobacter upsaliensis. In this study, 35 strains of Campylobacter and Arcobacter were tested for their ability to grow on CAT and mCCD media using the ecometric method. Six of these strains were also tested using the modified Miles-Misra method. Overall, nineteen strains out of the 35 tested grew better on CAT than on mCCD agar, although for eight strains, the difference was slight. These differences could not be attributed solely to poorer growth of C. upsaliensis on mCCD agar. No strain grew better on mCCD than CAT agar. Eight of the 35 strains tested did not grow on mCCD agar at all, however, only one strain failed to grow on CAT medium. The two methods of testing gave similar results, although the Miles-Misra method was found to be more sensitive and less prone to subjective interpretation. All four CNUPC (catalase negative, urease positive campylobacter-like) strains, one strain of C. sputorum biovar, fecalis, one of two Arcobacter cryaerophilus strains (incubated at 30 degrees C, aerobically) could be detected only using CAT agar. In addition, for some strains of A. butzleri, C. upsaliensis and C. hyointestinalis, CAT medium gave better growth scores than mCCD agar. The level of cefoperazone in mCCDA is inhibitory to some campylobacter strains, but suboptimal growth of Arcobacter strains is more probably due to synergistic interaction between deoxycholate and cefoperazone. CAT agar supports the growth of a wider variety of Campylobacter and Arcobacter species than mCCD agar. 相似文献