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Freshly isolated rabbit lenses were cultured in isosmolar TC-199 medium or hyperosmolar medium containing 180 mM sorbitol or mannitol. These experiments were performed to investigate the probable effects of hyperosmolar media on lens clarity and the ability of lens fiber cells to synthesize membrane intrinsic protein, MP-26. The data from these experiments show that incubation in hyperosmolar medium causes depressed MP-26 synthesis, whereas the presence of sugar alcohols in the culture medium induced anterior and posterior subcapsular opacities. The cation levels of lenses incubated in iso- and hyperosmolar medium were also measured. Data from these experiments revealed that although the experimental lenses display prominent opacities, their cation levels are generally similar to those of control lenses. It is proposed that the observed lens opacities are due to the presence of sugar alcohols in the culture medium and not to hyperosmolar shock. 相似文献
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A L Wagner F R Murtagh K S Hazlett J A Arrington 《AJNR. American journal of neuroradiology》1997,18(4):723
PURPOSETo develop an objective method for measuring the optic chiasm and to document its normal range in size.METHODSMeasurements of the height and area of the optic chiasm, made on coronal T1-weighted MR images with the use of commercially available region-of-interest software, were obtained in 114 healthy subjects who had a total of 123 MR studies. A normal range and standard deviation were calculated, and the information was broken down by age and sex.RESULTSThe mean area of the optic chiasm was 43.7 mm2, with a standard deviation of 5.21. The mean width was 14.0 mm, with a standard deviation of 1.68.CONCLUSIONThe area and width of the optic chiasm can be measured with the use of commercially available software, which allows an objective estimate of the chiasm''s size. Knowledge of the normal size range of the optic chiasm can be helpful in the early detection of some disorders. 相似文献
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Characterization of Pseudomonas aeruginosa adherence to mouse corneas in organ culture. 总被引:1,自引:5,他引:1
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The present study was designed to obtain further information on the nature of the corneal macromolecule(s) to which Pseudomonas aeruginosa adheres and how adherence might be prevented. Scarified adult mouse corneas in organ culture were treated with trypsin or lipase to determine whether the receptor molecule(s) was protein or lipid in nature. Trypsin (20 micrograms/ml) treatment of the cornea for 5 min had no significant effect on bacterial adherence, and longer periods of enzyme exposure resulted in extensive surface cell lysis. In contrast, lipase treatment (50,000 U/ml) for 1 h caused little visible cell lysis and significantly reduced bacterial adherence. To test further the lipid nature of the receptor, a highly purified monosialoganglioside (GM1) preparation (500 micrograms/ml) was used to preincubate (1 h) the cornea prior to bacterial application, and this also inhibited bacterial adherence. Similar corneal treatment with gangliotetraosylceramide (asialo GM1) (500 micrograms/ml) had little effect on ocular bacterial binding. Premixing of the bacterial inoculum with GM1 prior to corneal application had no significant effect on inhibiting bacterial binding, but similarly premixing the bacterial inoculum with asialo GM1 transiently decreased adherence. Lastly, premixing of the bacterial inoculum or preincubation of corneas with fibronectin (500 micrograms/ml for 1 h) both decreased bacterial adherence. These findings provide evidence that the receptor-adhesin interactions of P. aeruginosa at the ocular surface in organ culture are complex, involve a glycolipid moiety, and may be blocked by a ganglioside containing at least one sialosyl residue or by fibronectin, which may bind to membrane-associated gangliosides. 相似文献
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The ocular damage in young adult mice produced by purified Pseudomonas aeruginosa exotoxin A was microscopically characterized at 1 and 5 h and at 1, 3, 5, 7, 10, 14, and 21 days after toxin A challenge, using light, transmission, and scanning electron microscopic techniques. Similarly to previously described infection with viable organisms, toxin A killed both epithelial and endothelial cells and induced stromal cell swelling within 5 to 24 h after application onto the nonpenetrating wounded corneal surface. Other toxin-induced damage similar to the damage produced by infection with the viable bacteria was production of electron-dense particles within the corneal stroma, dispersal of undamaged collagen fibrils, and apparent loss of stromal proteoglycan ground substance. Toxin A damage differed from infection with the viable bacteria in essentially two ways. First, more purulent exudate and more polymorphonuclear neutrophilic leukocyte (PMN) infiltration of the corneal stroma were produced by infection with the viable organisms than by the toxin. Additionally, PMN did not appear within the toxin-treated corneas until 3 days after treatment, whereas in corneas infected with the viable organisms, PMN were numerous by 18 h. Secondly, toxin A produced cataract of the ocular lens, whereas infection with the viable organisms did not. 相似文献
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Jolinda LD Schram Joost Oude Groeniger Merel Schuring Karin I Proper Sandra H van Oostrom Suzan JW Robroek Alex Burdorf 《Scandinavian journal of work, environment & health》2021,47(2):127
Objective:Using a novel mediation method that presents unbiased results even in the presence of exposure–mediator interactions, this study estimated the extent to which working conditions and health behaviors contribute to educational inequalities in self-rated health in the workforce.Methods:Respondents of the longitudinal Survey of Health, Ageing, and Retirement in Europe (SHARE) in 16 countries were selected, aged 50–64 years, in paid employment at baseline and with information on education and self-rated health (N=15 028). Education, health behaviors [including body mass index (BMI)] and working conditions were measured at baseline and self-rated health at baseline and two-year follow-up. Causal mediation analysis with inverse odds weighting was used to estimate the total effect of education on self-rated health, decomposed into a natural direct effect (NDE) and natural indirect effect (NIE).Results:Lower educated workers were more likely to perceive their health as poor than higher educated workers [relative risk (RR) 1.48, 95% confidence interval (CI) 1.37–1.60]. They were also more likely to have unfavorable working conditions and unhealthy behaviors, except for alcohol consumption. When all working conditions were included, the remaining NDE was RR 1.30 (95% CI 1.15–1.44). When BMI and health behaviors were included, the remaining NDE was RR 1.40 (95% CI 1.27–1.54). Working conditions explained 38% and health behaviors and BMI explained 16% of educational inequalities in health. Including all mediators explained 64% of educational inequalities in self-rated health.Conclusions:Working conditions and health behaviors explain over half of the educational inequalities in self-rated health. To reduce health inequalities, improving working conditions seems to be more important than introducing health promotion programs in the workforce. 相似文献
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Lighvani S Huang X Trivedi PP Swanborg RH Hazlett LD 《European journal of immunology》2005,35(5):1567-1575
Studies have shown that after Pseudomonas aeruginosa (P. aeruginosa) corneal infection, BALB/c mice that are capable of resolving the disease, locally produce IFN-gamma. As T cells are not detected in the infected cornea of these mice, antibody depletion was used to test whether NK cells produce the cytokine. After depletion, decreased corneal IFN-gamma mRNA and increased disease severity, bacterial load, and PMN infiltrate resulted. Further work determined if substance P (SP), a pro-inflammatory neuropeptide, participated in regulation of this response. To this end, mice were treated with the SP antagonist, spantide I that blocks SP interaction with neurokinin-1, its major receptor. The treatment significantly decreased corneal IFN-gamma and IL-18 protein levels and corneal perforation resulted. In vitro experiments using isolated splenic NK cells confirmed their ability to respond to IL-18 and SP and to secrete IFN-gamma protein. We conclude: that for development of the BALB/c resistance response, NK cells are required to produce IFN-gamma; that the cells express the neurokinin-1 receptor; and that SP directly regulates IFN-gamma production through this receptor. The data suggest a unique link between the nervous system and development of innate immunity in the cornea. 相似文献