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941.
Cytofluorimetric detection of the multidrug resistance (MDR)-associated membrane protein (P-170) was performed at the time of diagnosis in 158 patients with acute myeloid leukemia using the C219 monoclonal antibody (MoAb). In 108 of these cases the JSB1 MoAb was also tested. An improved histogram subtraction analysis, based on curve fitting and statistical test was applied to distinguish antigen-positive from antigen-negative cells. A marker was considered positive when more than 20% of the cells were stained. At onset, P-170 was detected in 43% of cases with C219 and in 73% of cases with JSB1. There was a strict correlation between C219 and JSB1 positivity, as all C219+ cases were also positive for JSB1 MoAb (P < .001). No relationship was found between sex, age, organomegaly, and MDR phenotype. Significant correlation was found between CD7 and both C219 and JSB1 expression (P < .001 and .001, respectively). C219-negative phenotype was more often associated with a normal karyotype (24 of 55 with P = .030). Rhodamine 123 (Rh123) staining and flow cytometry analysis showed a significantly decreased mean fluorescence in 51 C219+ and 38 JSB1+ patients compared to 42 MDR negative ones (P < .001). The rate of first complete remission (CR) differed both between C219+ and C219- cases and between JSB+ and JSB- ones (30.9% v 71.1% and 35.4% v 93.1%, respectively, P < .001). Of the 21 C219+ patients who had yielded a first CR, 19 (90.4%) relapsed, compared with 28 of 64 (43.7%) C219- patients (P < .001). Of the 28 JSB1+ patients in first CR, 17 (60.7%) relapsed relative to 8 (29.6%) of 27 JSBI- ones (P = .021). A higher rate of relapses among MDR+ compared with MDR- patients was observed both for C219 and JSB1 MoAbs taken separately (C219 80% v 44%; JSB1 52% v 27%), with no relationship to age. The survival rates (Kaplan-Meyer method) were significantly shorter both in C219+ patients and in JSB1+ cases (P < .001). Disease-free survival curves followed this same trend. The combination (C219- JSB1+) identified a subset of patients with an intermediate outcome compared to C219 positive cases. The prognostic value of both markers (C219 and JSB1) was confirmed in multivariate analysis. These results suggest that the assessment of MDR phenotype by flow cytometry may be an important predictor of treatment outcome.  相似文献   
942.
Several hydrazine derivatives (HD) tested so far have pharmacological activities, but many also have toxic side effects, including carcinogenesis. Their toxicity has been ascribed to carbocations (via formation of azoxy intermediates), alkyl radicals or reactive oxygen species. Cytotoxicity and transformation by carbocations is widely accepted, but the role of alkyl radicals is still questioned. We have investigated the cytotoxicity of HD to mouse fibroblasts in three activation systems in which enhanced alkyl radical formation is demonstrated by electron spin resonance/spin-trapping. Cytotoxicity was assayed by inhibition of [3H-methyl]thymidine uptake into DNA of Balb/c 3T3 and/or Myc 9E fibroblasts (normal Balb/c 3T3 cells over-expressing the c-myc proto-oncogene). Based on the results obtained in the cytotoxicity assays we also investigated the transforming potential of procarbazine (PCZ) and methylhydrazine (MeH) activated by horseradish peroxidase (HRP) using the Myc 9E cell line, which aims at the activation of a second cooperating oncogene. Our results show that: (i) cytotoxicity of HD to mouse fibroblasts is increased by HRP activation of MeH, phenelzine and PCZ, which displayed enhanced alkyl radical formation, but not of 1,2-dimethylhydrazine (DMH), which did not produce increased alkyl radical formation under these conditions; (ii) cytotoxicity of neutrophil-activated MeH (producing a 10-fold higher concentration of methyl radicals), is more pronounced than DMH; (iii) MeH and DMH activated by prolonged auto-oxidation in 24-h incubations have comparable cytotoxicity and alkyl radical formation; and (iv) PCZ and MeH activation by HRP to alkyl radicals increased the transformation induced in Myc 9E cells. Taken together, our results strongly support a role for hydrazine-derived alkyl radicals in HD- induced cytotoxicity and cell transformation.   相似文献   
943.
OBJECTIVE: Both exogenous acids, from the diet, and endogenous acids, from stomach juice, can dissolve the enamel mineral, resulting in dental erosionS. Gastric acid may reach the mouth by gastro-oesophageal reflux disease (GERD), recurrent vomiting, rumination and regurgitation. These conditions are frequently found in the intellectually disabled population. Therefore, we investigated the presence of dental erosions in combination with GERD among intellectually disabled inhabitants, with an IQ<50, taken from three Dutch institutes.
MATERIALS AND METHODS: At random 63 individuals underwent an oesophageal pH test and dental screening and possible predisposing and attributable factors were determined. An abnormal pH level was defined as a pH <4, >4.5% of the measured time. Subjects with dental erosions were compared to those without dental erosions.
RESULTS: In 29 out of 63 (46.0%) cases evidence of dental erosions was found. In 19 of these 29 subjects with erosions (65.5%) GERD was diagnosed, compared to nine (26.5%) out of 34 subjects without erosions ( P = 0.04). In the subjects with erosions mean duration of pH <4 was 15.6% (range: 0.5–90.5) compared to 6.3% (range 0–40.4) in subjects without erosions ( P = 0.02).An IQ <35 was found to be predisposing ( P <0.001).
CONCLUSION: In this population of 63 institutionalised intellectually disabled persons dental erosions were diagnosed in 46%.Sixty-five per cent of them had GERD. Individuals with longer duration of pH <4 than 6.3% of the measured time and with an IQ < 35 were at higher risk to develop dental erosions. This study shows that dental erosions in the intellectually disabled population might be an oral manifestation of GERD.  相似文献   
944.
Wang  TC; Chiou  JM; Chang  YL; Hu  MC 《Carcinogenesis》1998,19(4):623-629
N-Nitroso propoxur (NP) can be synthesized from a widely used N- methylcarbamate insecticide, propoxur, in vitro in the laboratory. Because of the extensive use of aerosol propoxur, the adverse effect on cells of respiratory origin is worth elucidating. In this report, two mammalian cell cultures from respiratory tissues [a hamster lung fibroblast, V79, and a primary rat tracheal epithelial cell (RTE)], were used to investigate the genotoxicity of propoxur and NP. NP was more cytotoxic than propoxur, with LC50s (20 and six times smaller, respectively in V79 and RTE cells. NP significantly induced sister chromatid exchange (> or = 0.01 microg/ml), chromosome aberration (> or = 2.5 microg/ml) and hprt gene mutation (> or = 0.5 microg/ml) in V79 cells, and cell transformation (> or = 0.2 microg/ml) in RTE cells. Results of chromosome aberration and hprt gene mutation indicated that the major pre-mutagenic lesion induced by NP must be the O6- methylguanine adduct, which frequently mispairs with thymine and thus gives rise to a GC-->AT transition. Propoxur was not mutagenic to either type of cells. However, it inhibited gap-junctional intercellular communication in V79 cells, which indicates that propoxur could act through some epigenetic mechanisms, such as tumor promotion or cell proliferation, in the multiple process of chemical carcinogenesis.   相似文献   
945.
946.
947.
目的:研究二乙烯三胺五醋酸三钠锌盐及三钠钙盐注射液的离子对高效液相色谱测定。方法:以ODS(5μm,5mm×150mm)为色谱柱,流动相为甲醇-0.05mol/L醋酸钠缓冲液(pH4.5)(5:95),内含5mmol/L四丁基碘化胺,内标物为乙二胺四乙酸二钠,二乙烯三胺五醋酸(DTPA)及乙二胺四乙酸,(EDTA)与Fe~(3 )螯合成DTPA-Fe(Ⅲ)和EDTA-Fe(Ⅲ)复合物,其检测波长为280nm。结果:二乙烯三胺五醋酸的线性范围在20~320μg/ml,其三钠锌盐和三钠钙盐注射液5次测定的平均回收率±RSD分别为(101.33±0.65)%和(100.59±0.58)%。结论:此法重现性好,灵敏、特异,消除了多种金属离子的干扰。  相似文献   
948.
949.
Familial hemiplegic migraine (FHM) is an autosomal dominant type of migraine and probably represents the most extreme end of migraine with aura. Reduced magnesium facilitates the development of spreading depression and possibly aura. Cellular magnesium levels are under genetic control. We hypothesized that FHM patients would have significantly reduced intracellular magnesium levels. We determined intracellular and plasma magnesium levels in blood of 38 afflicted and 11 non-afflicted members of three families with FHM and, in 32 migraine patients (9 with and 23 without aura) and 32 age and sex matched healthy controls. We found no significant differences between the magnesium levels in the five study groups. We conclude that reduced blood magnesium is unlikely to be related to migraine pathophysiology.  相似文献   
950.

Background  

Manipur and Nagaland in northeast India are among the Indian states with the highest prevalence of HIV. Most prevention and care programs focus on identified "high risk" groups, but recent data suggest the epidemic is increasing among the general population, primarily through heterosexual sex. People with disability (PWD) in India are more likely than the general population to be illiterate, unemployed and impoverished, but little is known of their HIV risk.  相似文献   
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