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Ischemia and reperfusion-induced histologic changes in the rat retina. Demonstration of a free radical-mediated mechanism 总被引:6,自引:0,他引:6
M E Szabo M T Droy-Lefaix M Doly C Carré P Braquet 《Investigative ophthalmology & visual science》1991,32(5):1471-1478
Histologic alterations of ischemia- and reperfusion-induced retinal damage are critically dependent on the duration of the period of ischemia. Male Sprague Dawley rats were anesthetized, and a suture was placed behind the globe including the central retinal artery. Because it was desirable that untreated eyes show a great histologic change due to reperfusion-induced damage (in order that maximum scope would exist for demonstration of any protective effect of a drug treatment), a preliminary series of studies established the time-induced characteristics for the retina with transient regional ischemia. Eyes (n = 6-12 in each group) were subjected to 30, 60, or 90 min of ischemia followed by 0.5, 1, 2, 4, and 24 hr of reperfusion, respectively. The 30-min ischemia followed by reperfusion did not result in any histologic changes; 60-min ischemia followed by reperfusion induced a moderate retinal edema which returned to the preischemic value after 24 hr of reperfusion. The 90-min ischemia followed by reperfusion further aggravated retinal edema and increased the migration of neutrophil leukocytes. Even after 24 hr of reperfusion, the retinal edema had not disappeared although an attenuation was observed. In this study, the rats were treated with superoxide dismutase (SOD-PEG, 15 x 10(3) U/kg) or EGB 761 (100 mg/kg) for 10 days (chronic treatment). The SOD and EGB 761 significantly reduced the development of reperfusion-induced retinal edema and significantly prevented the neutrophil leukocyte infiltration. Both also had a protective effect against reperfusion-induced injury when these agents were administered just before reperfusion ("late" administration).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Hormonal imprinting takes place perinatally when a hormone and its maturing target receptor meet. As a consequence of imprinting the receptor accomplishes its maturation reaching the binding capacity characteristic to the adult age. In this critical period the presence of foreign molecules which are able to bind to the receptor can cause faulty imprinting with life-long consequences. In the recent years it was cleared that not only receptors are influenced by faulty imprinting, however, also the hormone production of the given cell. In addition imprinting was provoked at non-perinatal periods (adolescence and adult age) in cytogenic organs. In the present experiment the prolonged effect of a non-perinatal imprinting by an antihistamine to the histamine content of white blood cells and glucocorticoid receptors of liver and thymus was studied. Two weeks after 3-day terfenadine treatment at weaning, flow cytometry of peritoneal cells and blood lymphocytes for histamine, and receptor kinetic analysis of dexamethasone binding were done. Histamine content of blood lymphocytes and glucocorticoid receptor density of liver cells were significantly decreased. This means that a short treatment with a H(1)-receptor blocker antihistamine durably influences physiological indexes which were not known till now. This means that not only the acute effects, but the prolonged side-effects must be considered. 相似文献
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Balint Nagy Erno Toth-Pal Csaba Papp Zoltan Ban Zoltan Papp 《Fetal and pediatric pathology》1998,18(3):213-219
Cystic fibrosis (CF) is the most common autosomal recessive disorder in Caucasians. The most frequent mutation associated with cystic fibrosis has been identified as the 3 bp deletion Delta F 508. While existing polymerase chain reactions (PCR) (allele specific amplification) used to screen for CF are both sensitive and specific, we tested the prenatal application of fluorescent polymerase chain reaction and subsequent DNA fragment analysis that appears to be fast and sensitive. DNA samples (n=146) isolated from amniotic fluid (n=108), chorion villus biopsies (n=6), and human peripheral blood (n=32) were analyzed for the presence of Delta F 508 using the fluorescent method. Of these, 10 carriers of Delta F 508 mutation were detected. We achieved the same results with conventional PCR and fluorescent PCR. 相似文献
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Gábor RÉPÁssy Csaba Forster-HorvÁth Attila JuhÁsz Róza ÁDÁny Anna TamÁssy József TÍmÁr 《Pathology oncology research : POR》1998,4(1):14-21
Twelve laryngeal squamous cell carcinoma cases (7 laryngeal and 5 hypopharyngeal cancer; 15 samples) were analysed by immunohistochemistry
for the expression of invasion markers CD44v6/v3, NM23 and matrix metalloproteinase, MMP2. The laryngeal epithelium showed
CD44v6+v3+NM23- /MMP2- phenotype. When tumors were grouped into TNM categories the phenotype of the T2 and T3 tumors was similar, characterised
by decreased CD44v3+ and lack of MMP2 expressions. Meanwhile the NM23 expression was more frequent in T3 tumors. In T4 stage the frequency of
NM23 and MMP2 positive cases increased (5/6 and 4/6, respectively) but there was no correlation with the appearence of lymph
node metastasis. Comparison of the phenotype of laryngeal and hypopharyngeal tumors, irrespective of the TNM stages, revealed
characteristic differences: T2 stage laryngeal tumors showed decreased CD44v3 and occasional NM23 and MMP2 positivity, while
in T3 stage these tumors were characterised by increased frequency of NM23 positivity. The phenotype of the hypopharyngeal
tumors was significantly different with a high frequency of MMP2 positive cases (5/6) and NM23+1ow CD44v3+ phenotype. The sharp differences in the phenotypes of laryngeal and hypopharyngeal carcinomas were connected to the differences
in their invasive capacity unlike to the size of the tumors, since the T4 stage hypopharyngeal tumors had a significantly
smaller size than laryngeal ones, even at lower stages.
This work was supported by the Hungarian Ministry of Welfare: ETT No: T-11-100/93 相似文献
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* The vague definitions of so-called repetitive stress injuries are indicative of the fact that scientific studies have failed to show that repetitive motion causes injury. * Given the uncertainty about causation, work-related musculoskeletal disorders (WRMSDs) is a more readily accepted term to describe these phenomena. * There is little doubt that most ergonomic interventions increase comfort in the work environment, which is of great benefit to the worker. Many proponents of ergonomics assert that the elimination of certain risk factors related to force, repetition, and posture can prevent or even cure work-related musculoskeletal disorders of the upper extremity. However, there is little scientific support for this position. * Undue reliance on ergonomics to treat musculoskeletal disorders, to the exclusion of proper diagnosis and attention to medical and health risk factors, can have adverse consequences for the patient. * Science rather than politics and public policy should determine what causes injury and disease. * The failure of numerous plaintiffs in litigation regarding repetitive stress injury due to use of computer keyboards is important because, when judges and lay jurors were presented with both sides of the issue, they rejected these claims in a forum (the judicial system) that traditionally compensates individuals bringing so-called mass-tort cases. 相似文献
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