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M protein and protein F act as important determinants of cell-specific tropism of Streptococcus pyogenes in skin tissue. 总被引:10,自引:2,他引:8 下载免费PDF全文
The pathogenic gram-positive bacterium Streptococcus pyogenes (group A streptococcus) causes numerous diseases of cutaneous tissue, each of which is initiated after the interaction of the bacterium with the cells of the epidermis. In this study, we show that different surface proteins of S. pyogenes play important roles in determining the cell-specific tropism of the bacterium in skin. Using streptococcal strains with defined mutations in the genes which encode surface proteins in combination with primary cultures of human skin and an in situ adherence assay which uses histological sections of human skin, we show that the M protein of S. pyogenes mediates the binding of the bacterium to keratinocytes, while a second streptococcal surface protein, protein F, directs the adherence of the organism to Langerhans' cells. Characterization of binding revealed that adherence was inhibited by purified streptococcal proteins and pretreatment of both host cells with the protease trypsin. Adherence was only slightly affected by the state of keratinocyte differentiation in vitro, but was considerably modulated in response to environmental conditions known to regulate expression of M protein and protein F, suggesting that the interaction between these bacterial cell-surface structures/adhesins and keratinocytes and Langerhans' cells may play an important role in streptococcal skin disease. 相似文献
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To clarify the circadian aspects of delayed sleep phase syndrome (DSPS) in 4 patients with DSPS, we recorded polysomnograms and rectal temperature before and after chronotherapy. The time interval (2.7 h) between sleep onset and rectal temperature minimum before chronotherapy was shorter than the time interval after chronotherapy (5.3 h). Before chronotherapy, the period of rectal temperature rhythm was 24.7 h. After chronotherapy, the period of rectal temperature rhythm was 24.0 h. These findings lead to the conclusion that in DSPS there is a weakened mechanism of entrainment similar to that in non-24-hour sleep-wake syndrome. 相似文献
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Estrone and estradiol-17 beta concentration in breast cancer tissue are reported to be an order of magnitude higher than those of circulating plasma in breast cancer patients. This high level of estrogen is provided by local production from estrone sulfate (E1-S) through the sulfatase pathway. Then serum E1-S level was determined using direct radioimmunoassay method in order to monitor the estrogen kinetics of post-operative breast cancer patients. Peri-operative sequential E1-S determination was carried out in 10 patients. Among them, extremely higher level, as compared with normal menstruating level of 625-2670pg/ml, was observed just after an administration of tamoxifen (three weeks after operation) in two of 5 pre-menopausal patients. In order to evaluate the effect of tamoxifen on serum level of E1-S in post-operative pre-menopausal patients, serum E1-S level in 42 post-operative outpatients was examined. Although there was no difference in the average level of E1-S in post-menopausal patients treated with or without tamoxifen, average E1-S level in pre-menopausal patients treated with tamoxifen as adjuvant therapy was significantly higher than that in patients without tamoxifen. These results suggests that the administration of tamoxifen to premenopausal patients should be reconsidered from a view point of the estrogen kinetics. 相似文献
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M Uchida T Fujiwara T Wada S Nakajima H Sato Y Nakata H Yamaguchi S Kawai R Okada T Kano 《Journal of cardiology》1988,18(4):1043-1050
The effect of hypertension on asymmetrical septal hypertrophy was studied by echocardiography to differentiate idiopathic asymmetrical septal hypertrophy (ASH) from ASH with hypertension. One hundred eight patients with ASH proven by echocardiography were categorized in two groups; 53 patients with hypertension (greater than 160 systolic, greater than 95 diastolic) (hypertensive group: HT) and 55 patients with normal blood pressure (normotensive group: NT). Septal hypertrophy was classified as mid-portion (M-type), diffuse (D-type), and basal (B-type) hypertrophy by the long-axis view, and also diffuse (I-type), anterolateral (II-type), anteroseptal (III-type), and anterior septal (IV-type) by the short-axis view, respectively. Endomyocardial biopsy and left ventriculography were performed in 50 patients (18 hypertensives and 32 normotensives). In the hypertensive group, 45%, 30%, and 25% of cases had diffuse, basal and mid-portion hypertrophy, respectively. There was no case in the basal hypertrophy whose biopsy findings were compatible with hypertrophic cardiomyopathy. In the normotensive group, 78% and 22% of patients had midportion and diffuse hypertrophy, respectively, but none of them had the basal hypertrophy. Type IV was seen in only six patients in the normotensive group. 相似文献
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Hiroyoshi Matsukura M.D. Akira Higuchi M.D. Yoshifumi Suzuki M.D. Toshio Okada M.D. 《Pediatrics international》1987,29(2):277-279
A patient presenting with osteomyelitis of the pelvis is described. In this case it was difficult to establish a correct diagnosis by use of scintigraphic scanning, in spite of clear roentgenographic evidence of osteomyelitis. 相似文献