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991.
The role of complement activation in atherosclerosis 总被引:6,自引:0,他引:6
Atherosclerosis is a chronic inflammatory disease in which dyslipidemia, inflammation, and the immune system play an important pathogenetic role. A role in atherogenesis was demonstrated for monocyte/macrophages, complement system, and T-lymphocytes. Complement activation and C5b-9 deposition occurs both in human and experimental atherosclerosis. Complement C6 deficiency has a protective effect on diet-induced atherosclerosis, indicating that C5b-9 assembly is required for the progression of atherosclerotic lesions. The maturation of atherosclerotic lesions beyond the foam cell stage was shown to be strongly dependent on an intact complement system. C5b-9 may be responsible for cell lysis, and sublytic assembly of C5b-9 induces smooth muscle cell (SMC) and endothelial cell (EC) activation and proliferation. All these data suggest that activation of the complement system plays an important role in atherogenesis. 相似文献
992.
Michael Z. Gilcrease MD PhD Laura Schmidt PhD Berton Zbar MD Luan Truong MD Michael Rutledge MD Thomas M. Wheeler MD 《Human pathology》1995,26(12)
Papillary cystadenoma of the epididymis is an uncommon benign lesion that may occur sporadically or as a manifestation of von Hippel—Lindau (VHL) disease. Neither immunohistochemical studies nor molecular genetic analyses of the VHL gene have been reported previously for this lesion. The authors describe two cases of clear cell papillary cystadenoma of the epididymis, both of which were initially confused with metastatic renal cell carcinoma. Both lesions showed positive immunohistochemical staining for low and intermediate molecular weight keratins (Cam 5.2 and AE1/AE3), EMA, vimentin, α1-antitrypsin, and α1-antichymotrypsin. Each was negative for CEA. Because clear cell papillary cystadenoma is similar to renal cell carcinoma histologically, and because both occur as components of the von Hippel—Lindau disease complex, the authors analyzed both cases for the presence of mutations in the VHL gene. A somatic VHL gene mutation was detected in one of the two tumors by polymerase chain reaction followed by single-strand conformation polymorphism analysis. Direct sequencing revealed a cytosine to thymine transition at nucleotide 694, resulting in the replacement of an arginine with a stop codon after the sixth amino acid of exon 3. As the VHL gene is believed to function as a tumor suppressor gene, VHL gene mutations may play a role in the initiation of tumorigenesis in sporadic cystadenomas of the epididymis. 相似文献
993.
994.
Intoxication of cultured human lung fibroblasts with Clostridium difficile toxin. 总被引:5,自引:6,他引:5
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The cytopathogenic effect of partially purified toxin from Clostridium difficile on cultured human lung fibroblasts was studied. Conditions for determination of 50% tissue culture dose were standardized. The cytopathogenic effect of the toxin was dependent on toxin concentration, exposure time, and density of the cells. Transfer of the cells to 0 degrees C did not inhibit binding of toxin to the fibroblast surface, but prevented the development of the cytopathogenic effect. Both binding of toxin and some intracellular step(s) were prevented by 2,4-dinitrophenol. These preventative effects were reversible. Before and concomitantly with the appearance of the cytopathogenic effect, the cellular uptake of uridine and of amino acids was markedly stimulated. Protein synthesis was depressed when 100% of the cells showed the cytopathogenic effect, but the synthesis of nucleic acids was inhibited only several hours later. The primary cellular target for the toxin is still unknown. 相似文献
995.
Donangelo I Marcos HP Araújo PB Marcondes J Filho PN Gadelha M Chimelli L 《Endocrine pathology》2005,16(1):53-62
The retinoblastoma gene (RB1) is a tumor-suppressor gene in chromosomal region 13q14.2. Its role in the pathogenesis of pituitary tumors has not been
fully clarified. Some studies have shown that losses in this chromosomal region are related to aggressive tumor behavior,
although the retinoblastoma protein (pRB) is still expressed. Conversely, lack of expression of pRB was observed in one fourth
of GH-secreting pituitary adenomas (GH-tumors). In order to further study the expression of pRB in GH-tumors, we evaluated
this protein in 49 tumors from patients with acromegaly (20 noninvasive, 25 invasive, and 4 with no information) and 8 normal
pituitaries using immunohistochemistry (IHC). Nuclear staining for pRB ranged from 0 to 90% (median 40%) in the tumors and
from 40 to 80% (median 58%) in normal pituitaries. In 10 tumors (20% of total) the adenomatous cells were negative (5 cases)
or had very low labeling (5 cases) for pRB. Sixty three percent (31/49) of the tumors showed staining in 10–80% of the cells
and in 16% (8/49) of the cases >80% of the adenomatous cells were positive for pRB. The expression of pRB was not different
in invasive and noninvasive tumors. In conclusion, pRB is underexpressed in a subgroup of GH-tumors, and this may represent
an early event in the pathogenesis of this tumor subtype. 相似文献
996.
Retinoblastoma and p53 gene product expression in breast carcinoma: Immunohistochemical analysis and clinicopathologic correlation 总被引:9,自引:0,他引:9
Michel Trudel MD Lois Mulligan PhD Webster Cavenee PhD Richard Margolese MD Jean Ct MD Gilles Garipy MD 《Human pathology》1992,23(12):1388-1394
We examined 100 breast cancers for retinoblastoma (Rb) and p53 protein expression by immunohistochemistry using the PMG3.245 and PAb 1801 antibodies. We assessed percentages of reactive cells and their intensity, as well as staining patterns. The results were correlated with neu protein reactivity and a panel of variables, including age, tumor size and type, nuclear grade, estrogen receptor/progesterone receptor content, and lymph node status. Retinoblastoma protein negativity, either partial or complete, was noted in 47% of cases. Surprisingly, a relatively stronger Rb reaction was seen in some high nuclear grade tumors. p53 positivity was found in 23% of cases and was a significant predictor of Rb loss. p53 also was correlated with poorly differentiated (nuclear grade III) neoplasms and neu expression but not with negative ER status. Tissue distribution profiles for Rb-negative and p53-positive cells were variable in this series, with both uniform and heterogeneous patterns observed. This suggests that Rb and p53 alterations may represent early or late events in transformation. Our findings further implicate Rb and p53 derangements in mammary oncogenesis. 相似文献
997.
Kerstin Eberhardt MD PhD Britt-Marie Larsson Social worker Kerstin Nived Social worker 《Patient education and counseling》1993,20(2-3):93-100
We report the interaction of RA and psychological factors over 2 years in a group of 89 patients with newly established disease. Short-time outcome regarding physical features was fairly good. Disease activity decreased, and disability evaluated by HAQ remained at a low level. Psychological distress as measured by the depression and anxiety subscales of SCL 90 (Symptom Check List) was not very pronounced and not related to disease state factors. A slight decrease of anxiety was recorded after 2 years. A new adjustment test was applied. It contained 13 items focused mainly on negative illness effects such as loss of independence, feelings of guilt, and change of social and leisure time activities. Three factors (regret of lost life values, dysphoric mood, and acceptance) explained 48% of the variance of the 13 items. The validity of the test was acceptable. The patients' degree of adjustment changed slowly or not at all during the 2 years. 相似文献
998.
H. Ohno PhD F. Hirata K. Terayama T. Kawarabayashi R. Doi T. Kondo N. Taniguchi 《European journal of applied physiology》1983,51(2):257-268
Summary Studies of the influences of physical exercise of short duration (bicycle ergometer, 200 W for 30 min) on the activities of carbonic anhydrase isoenzymes (CA-B and CA-C types) and zinc concentration in erythrocytes were made on 5 untrained healthy male volunteers. The subjects were rested for 30 min after the exercise. There were significant decreases in the levels of zinc, CA-B, total carbonic anhydrase activity and CA-B-dependent activity immediately after exercise, but after 30 min of rest they all returned to their pre-exercise levels. No significant change in CA-C level or CA-C-dependent activity was found after exercise. Immediately after exercise, total carbonic anhydrase activity and CA-B-dependent activity following the addition of Zn2+ showed significant increases, compared with their respective activities without Zn2+ addition. However, no such effects were observed just before exercise or after rest; the addition of Zn2+ had no effect on CA-C-dependent activity at any time. A significant correlation was found between the changes in concentration of zinc and CA-B-dependent activity after exercise (r=0.711). The findings of the present study suggest that active CA-B enzymes are converted in part to inactive enzymes during acute physical exercise, possibly by decreased zinc binding. Moreover, the change in CA-B-dependent activity correlated well with the changes in pH and HCO3 concentrations in venous blood (r=0.853 and r=0.718, respectively). One may speculate that an adaptive decrease in CA-B-dependent activity in erythrocytes occurs with increased acidification in blood during heavy physical exercise of short duration.The present study was presented to the Fifth International Symposium on the Biochemistry of Exercise, Boston, June 1–5, 1982 相似文献
999.
Anita Samuelsson MSc Monica Ahlmn MD Marianne Sullivan PhD 《Patient education and counseling》1993,20(2-3):77-91
During the last few years, studies have revealed that the need for psychosocial support and concrete social services are great in the early stages of the treatment of rheumatic diseases. The ability to keep a job, to do household chores, to participate in leisure activities and to maintain social relations is clearly impaired. Anxiety and depression are not unusual and often associated with weak support from relatives, loneliness and disturbed family relations. Nevertheless, the patients report resilience and determination to cope with the impacts of illness. Crisis intervention, vocational guidance and counselling about problems concerning the disease should be available and offered to the patients. As the patients seem to be unaccustomed to talking about their psychosocial problems, an empathetic and information-seeking attitude on the part of the health care staff is essential. 相似文献
1000.