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61.
In an earlier study, the genotypes associated with higher level of transforming growth factor‐β1 (TGF‐β1) were found to reduce the risk for breast cancer in western Indian women. This observation implied that gene polymorphisms affecting the levels of pro‐ and anti‐inflammatory cytokines may influence the risk for breast cancer in this population. Hence, we performed genotyping for three more functional single‐nucleotide polymorphisms (SNPs) responsible for variations in the levels of cytokines associated with inflammation. To that effect, polymorphisms in genes coding for IL‐4 (IL‐4 C‐590T; rs2243250), IFN‐γ (IFN‐G A + 874T; rs2430561) and MCP‐1 (MCP‐1 A‐2578G; rs1024611) were examined in premenopausal, healthy women (N = 239) and patients with breast cancer (N = 182) from western India. In carriers of the IL‐4*590T allele, a reduced risk for the disease (dominant model; OR = 0.61, 95% CI 0.37–0.98) was seen similar to that seen in TGF‐B1*10C carriers. An opposite trend was observed with respect to the alleles associated with higher expression of MCP‐1 or IFN‐γ. In individuals positive for three or more alleles associated with higher levels of either pro‐ or anti‐inflammatory cytokines, an additive effect on the modulation of risk for the disease was evident (for TGF‐B1 & IL‐4, OR = 0.33, 95% CI 0.12–0.87; for IFN‐G & MCP‐1, OR = 2.29, 95% CI 0.95–5.51). In the context of contrasting observations in other populations, these results indicate a significant contribution of anti‐inflammatory genotypes in the modulation of risk for breast cancer in western Indian women.  相似文献   
62.
In our earlier studies, single nucleotide polymorphisms (SNPs) associated with anti-inflammatory cytokines were found to influence risk for breast cancer in western Indian women. Analysis of Interleukin 6 (IL-6) −174G>C polymorphism in this cohort (patients = 182; controls = 236) suggested a protective role for IL-6 −174C allele associated with the lower expression of the cytokine (OR = 0.54; 95% CI 0.32–0.89, dominant model). Together these observations suggested that in comparison to Caucasians, inflammation associated-cytokine gene polymorphisms may have higher influence on risk for cancer in this population. To examine this possibility we analyzed data assessing influence of Interleukin 6 (IL-6) −174G>C polymorphism on risk for various cancers. Overall, there was a marginally higher risk for rare allele homozygotes compared to wild type homozygotes (OR = 1.07; 95% CI 1.00–1.15). Increased risks for genitourinary cancers and for skin cancer were also indicated. The ethnicity based analysis indicated a protective effect of the minor allele in Ancestral North Indians (OR = 0.73; 95% CI 0.55–0.97). Site by ethnicity analysis once again revealed a significant protection against breast cancer (OR = 0.51; 95% CI = 0.37–0.70; dominant model) but an opposite influence on the risk of genitourinary malignancies (OR = 2.51; 95% CI 1.59–3.96; recessive model) in this population alone. The observations imply that contribution of IL-6 to inflammation or effector immunity may depend on the site of malignancy. Assessment of available data in relation to prognosis in breast cancer patients also revealed trends that are compatible with the observations of the meta-analysis. Thus, IL-6 −174G>C polymorphism clearly represents a potential modulator of risk for malignant disorders with ethnicity and site dependent trends. The results also support the possibility of higher influence of inflammation related cytokine gene polymorphisms on the risk for cancers in Ancestral North Indians.  相似文献   
63.
Segmentation of lung parenchyma from the chest computed tomography is an important task in analysis of chest computed tomography for diagnosis of lung disorders. It is a challenging task especially in the presence of peripherally placed pathology bearing regions. In this work, we propose a segmentation approach to segment lung parenchyma from chest. The first step is to segment the lungs using iterative thresholding followed by morphological operations. If the two lungs are not separated, the lung junction and its neighborhood are identified and local thresholding is applied. The second step is to extract shape features of the two lungs. The third step is to use a multilayer feed forward neural network to determine if the segmented lung parenchyma is complete, based on the extracted features. The final step is to reconstruct the two lungs in case of incomplete segmentation, by exploiting the fact that in majority of the cases, at least one of the two lungs would have been segmented correctly by the first step. Hence, the complete lung is determined based on the shape and region properties and the incomplete lung is reconstructed by applying graphical methods, namely, reflection and translation. The proposed approach has been tested in a computer-aided diagnosis system for diagnosis of lung disorders, namely, bronchiectasis, tuberculosis, and pneumonia. An accuracy of 97.37 % has been achieved by the proposed approach whereas the conventional thresholding approach was unable to detect peripheral pathology-bearing regions. The results obtained prove to be better than that achieved using conventional thresholding and morphological operations.  相似文献   
64.
Administration of supraphysiological doses of testosterone to normal men causes inhibition of spermatogenesis, but while most become azoospermic, 30-55% maintain a low rate of spermatogenesis. We have investigated whether there are differences in endogenous androgen production, of testicular and adrenal origin, which may be related to the degree of suppression of spermatogenesis. Thirty-three healthy Caucasian men were given weekly i.m. injections of 200 mg testosterone oenanthate (TE), 18 became azoospermic, while 15 remained oligozoospermic. Urinary excretion of epitestosterone, a specific testicular product, was reduced to <10% of pretreatment values, with no differences between the groups. Similar results were obtained for other markers of testicular steroidogenesis. Urinary and plasma adrenal androgens were also reduced during TE treatment: a statistically significant decrease in both (P < 0.001 and P < 0.05 respectively) was seen in the azoospermic but not oligozoospermic responders. These results suggest that testicular steroidogenesis is decreased to <10% by the administration of supraphysiological doses of exogenous testosterone. Differences in the degree of ongoing steroidogenesis in the testis do not appear to account for incomplete suppression of spermatogenesis, thus differences in androgen metabolism may underlie this heterogeneous response. A small but significant reduction in secretion of adrenal androgens was also detectable, the relevance of which is unclear.   相似文献   
65.
The Ly49 family of natural killer (NK) receptors regulates NK cell function by sensing major histocompatibility complex (MHC) class I. Ly49 receptors show complex patterns of MHC class I cross-reactivity and, in certain cases, peptide selectivity. To investigate whether specificity differences result from topological differences in MHC class I engagement, we determined the structure of the peptide-selective receptor Ly49C in complex with H-2K(b). The Ly49C homodimer binds two MHC class I molecules in symmetrical way, a mode distinct from that of Ly49A, which binds MHC class I asymmetrically. Ly49C does not directly contact the MHC-bound peptide. In addition, MHC crosslinking by Ly49C was demonstrated in solution. We propose a dynamic model for Ly49-MHC class I interactions involving conformational changes in the receptor, whereby variations in Ly49 dimerization mediate different MHC-binding modes.  相似文献   
66.
We describe the clinical and demographic characteristics, virological follow-up, and management of five confirmed monkeypox cases from New Delhi, India without any international travel history. The viral load kinetics and viral clearance were estimated in oropharyngeal swabs (OPS), nasopharyngeal swabs (NPS), EDTA blood, serum, urine, and various lesion specimens on every fourth day of follow-up ranging from 5 to 24 post onset day (POD) of illness. All five cases presented with mild to moderate-grade intermittent fever, myalgia, and lesions on the genitals, groins, lower limb, trunk, and upper limb. Four cases had non-tender firm lymphadenopathy. No secondary complications or sexually transmitted infections were recorded in these cases except for the presence of viral hepatitis B infection marker hepatitis B virus surface antigen (HBsAg) in one case. All the cases were mild and had a good recovery. A higher viral load was detected in lesion fluid (POD 9), followed by lesion roof (POD 9), urine (POD 5), lesion base (POD 5), and OPS/NPS (POD 5). The monkeypox virus (MPXV) DNA was detected in clinical samples from 5th to 24th POD. These monkeypox cases without international travel history suggest the underdiagnosed monkeypox infection in the community. This emphasizes the need for active surveillance of MPXV in the high-risk population such as men having sex with men and female sex workers.  相似文献   
67.
OBJECTIVES: Oral hairy leukoplakia (HL) is an acan-thotic, hyperparakeratotic lesion characterised by the presence of a replicative Epstein-Barr virus (EBV) infection in the superficial and adjoining layers of the epithelium. EBV or its gene products are capable of modifying epithelial differentiation. The aim of this study was to establish whether the presence of EBV was associated with an alteration in cell turnover by assessing bromodeoxyuridine (BrdU) incorporation and Ki 67 expression in lesional tissue and control mucosa.
METHODS: Biopsies of HL together with age, site and sex matched controls ( n = 7 and 8 respectively) were incubated in 200 μM BrdU in vitro , fixed in methacarn and processed to paraffin wax. Following acid hydrolysis, incorporated BrdU and Ki 67 were identified in serial 5 fim sections using a three-stage immunoperoxidase technique and cell density expressed as the number of positive cells per mm basement membrane length.
RESULTS: Overall, there was no difference in the number of BrdU positive cells per mm basement membrane length between control and HL tissue. However, within HL alone, the presence'of focal EBV replication was associated with a significant reduction in the number of basal cells incorporating BrdU compared to adjacent EBV free areas (P < 0.05). There was no significant difference between Ki 67 positive cells in control and HL tissue and no evidence of a reduction of Ki 67 positive cells in areas associated with EBV replication.
CONCLUSIONS: These results suggest that there is no evidence of a generalised alteration of the proliferative capacity of basal cells in HL, although the focal reduction in BrdU incorporation may reflect subtle changes on cell turnover by EBV infection.  相似文献   
68.
69.
Amiodarone, an iodine containing anti-arrhythmic drug, causes a significant decrease in molar ratio of daily production rates of T3 and T4 from 0.75 in controls to 0.36 in amiodarone-treated rabbits. A model was constructed from the above data which showed that metabolism of T4 via non-deiodinative pathways (e.g. tetraiodothyroacetic acid and/or conjugates) increased from 29% in untreated controls to 66% in amiodarone-treated rabbits. In this study, we have examined the metabolic clearance rate of tetraiodothyroacetic acid in rabbits given amiodarone (20 mg.kg-1.day-1 ip for 3 weeks) or saline (controls). Serum amiodarone and desethylamiodarone levels under the above experimental conditions were 0.20 +/- 0.067 and 0.17 +/- 0.058 mg/l, respectively, which were in the near-therapeutic range observed in humans. Control and amiodarone-treated rabbits were administered [125I]-tetraiodothyroacetic acid (10 muCi/rabbit) iv and blood was collected at 0.5, 1, 2, 4, 6, 10, 32 and 48 h. Serum tetraiodothyroacetic acid radioactivity was determined by trichloroacetic acid precipitation and ethanol extraction and metabolic clearance rates were calculated from the area under the curve of computer fits to tetraiodothyroacetic acid radioactivity data. Amiodarone treatment decreased metabolic clearance rates significantly from 0.107 +/- 0.008 in controls to 0.074 +/- 0.009 l/day in amiodarone-treated rabbits (p less than 0.05). However, when expressed per unit body weight (1.day-1.kg-1), the metabolic clearance rates were not significantly different between the controls and amiodarone-treated rabbits. The terminal serum elimination half-life in the two groups were similar (32.0 +/- 6.7 h in controls vs 49.2 +/- 12.4 h in amiodarone-treated).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
70.
Kunicki  TJ; Pidard  D; Rosa  JP; Nurden  AT 《Blood》1981,58(2):268-278
Triton X-100 soluble proteins from 125I-labeled human platelets were studied by crossed immunoelectrophoresis employing a multispecific rabbit antibody raised against whole normal platelets. Emphasis was placed upon an analysis of immunoprecipitates containing 125I-labeled major membrane glycoproteins, and in particular, a prominent immunoprecipitate containing a glycoprotein antigen (s) previously designated as protein 16. SDS-polyacrylamide gel electrophoresis of protein 16 precipitated by a monospecific alloantibody. IgG L . . . , confirmed the presence of both glycoproteins IIb and IIIa. 125I-IgG L . . . , at concentration below that capable of precipitating protein 16 by itself, bound specifically to the precipitate containing protein 16 produced by the multispecific rabbit antibody. No other precipitates formed by the rabbit antibody contained either glycoprotein IIb or IIIa. When platelet proteins, incubated with optimum concentrations of ethylenediamine tetraacetic acid (EDTA) or ethyleneglycol bis (B- aminoethylether) NN1-tetraacetic acid (EGTA), were electrophoresed against the rabbit antibody, previously unobserved immunoprecipitates that contained either free glycoprotein IIb or free glycoprotein IIIa were detected. Upon readdition of excess Ca++, but not Mg++, to the same protein samples, a single immunoprecipitate containing both glycoproteins was once again observed. It is thus demonstrated that glycoproteins IIb and IIIa can form Ca++-dependent complexes (protein 16) in Triton X-100 extracts of normal platelets. The potential significance of the reversible association of these glycoproteins to normal platelet function is discussed.  相似文献   
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