Cyclin D1 polymorphism and risk for squamous cell carcinoma of the head and neck: a case-control study

A G-->A polymorphism (G870A) in exon 4 of the cyclin D1 (CCND1) gene creates an alternative splice site in its mRNA, encoding a protein with an altered C-terminal domain. It has been suggested that DNA damage in cells with the A allele bypasses the G(1)/S checkpoint of the cell cycle more easily than damage in cells without the A allele. Because CCND1 plays a critical role in cell cycle control and reduced DNA repair capacity is associated with an increased risk for squamous cell carcinoma of the head and neck (SCCHN), we hypothesize that this CCND1 polymorphism modulates individual susceptibility to SCCHN. To test this hypothesis we evaluated the frequency of the polymorphism in a hospital-based case-control study of 233 newly diagnosed SCCHN patients and 248 non-cancer controls. The cases and controls were frequency matched by age (+/-5 years), sex and tobacco use. All subjects were non-Hispanic whites. We found that the A allele frequency was slightly higher in the cases (0.485) than in the controls (0.425), but the difference was borderline statistically significant (P = 0.064). The frequencies of the CCND1 AA, GA and GG genotypes were 23.6, 49.8 and 26.6%, respectively, in cases and 16.5, 52.5 and 31.5%, respectively, in controls. Multivariate logistic regression analysis adjusting for age (in years), sex, smoking and alcohol use was performed to calculate odds ratios (OR) and 95% confidence intervals (CI). Compared with the wild-type CCND1 GG, the CCND1 A G genotype was associated with a non-significantly increased risk (adjusted OR 1.15, 95% CI 0.75-1.76), but the CCND1 AA genotype was associated with a significantly increased risk (adjusted OR 1.77, 95% CI 1.04-3.02) for SCCHN. Results from a trend test using a logistic regression model were statistically significant (P = 0.044). Among the cases the mean age of onset was 59.0, 56.8 and 55.5 years for the GG, GA and AA genotypes, respectively. In the stratification analysis the CCND1 AA variant genotype was associated with a >3-fold increased risk in individuals who were 相似文献   

Antisweet saponins from Gymnema sylvestre.

Three new oleanane-type triterpene glycosides (1-3), along with the sodium salt of alternoside II (4), were isolated from an ethanol extract of the leaves of Gymnema sylvestre. The structures of these new saponins were identified as 21 beta-O-benzoylsitakisogenin 3-O-beta-D-glucopyranosyl(1-->3)-beta-D-glucuronopyranoside (1), the potassium salt of longispinogenin 3-O-beta-D-glucopyranosyl(1-->3)-beta-D-glucuronopyranoside (2), and the potassium salt of 29-hydroxylongispinogenin 3-O-beta-D-glucopyranosyl(1-->3)-beta-D-glucuronopyranoside (3). The aglycon of 3, gymnemagenol (3a), was characterized as 3 beta,16 beta,28, 29-tetrahydroxyolean-12-ene. Structure elucidation was accomplished by interpretation of NMR (DQF-COSY, HMQC, and HMBC) results, FABMS, and hydrolysis. Saponin 1 and the sodium salt of alternoside II (4) exhibited antisweet activity.     

Anti-AIDS agents. 46. Anti-HIV activity of harman, an anti-HIV principle from Symplocos setchuensis, and its derivatives

Matairesinol (1) and harman (5), identified from Symplocos setchuensis, were found to inhibit HIV replication in H9 lymphocyte cells. Anti-HIV evaluation of 28 derivatives of 5 revealed that compound 19 showed potent activity with EC(50) and therapeutic index values of 0.037 microM and 210, respectively.     

Three new sesquiterpene glycosides from Dendrobium nobile with immunomodulatory activity

Dendroside A (1) and dendronobilosides A and B (2 and 3), three new sesquiterpene glycosides, have been isolated from the stems of Dendrobium nobile, a plant used in Chinese traditional medicine. Their structures and stereochemistry were determined as 10beta,12,14-trihydroxyalloaromadendrane 14-O-beta-D-glucopyranoside (1), 10,12-dihydroxypicrotoxane 10,12-di-O-beta-D-glucopyranoside (2), and 6alpha,10,12-trihydroxypicrotoxane 10-O-beta-D-glucopyranoside (3), respectively, on the basis of spectroscopic and chemical methods. Quantum chemistry calculations were used in support of the structural determination of 1. Compounds 1 and 2 were found to stimulate the proliferation of murine T and B lymphocytes in vitro, while compound 3 showed inhibitory activity in this same assay.     

Prognostic significance of multidrug resistance protein in adult T-cell leukemia.

The response of adult T-cell leukemia (ATL) to chemotherapy is poor, and a major obstacle to successful treatment is intrinsic or acquired drug resistance. To determine the clinical significance of multidrug resistance protein (MRP) 1 in ATL, we studied MRP1 expression and its association with clinical outcome. The expression of MRP1 mRNA in leukemia cells from 48 ATL patients was studied by slot blot analysis. The expression level of MRP1 mRNA in chronic-type ATL was significantly higher than that in lymphoma-type ATL (P = 0.033). There was no correlation between MRP1 expression and age, gender, WBC count, LDH, hypercalcemia, blood urea nitrogen, or performance status. However, the expression of MRP1 mRNA correlated only with peripheral blood abnormal lymphocyte counts (P = 0.008). The transporting activity of MRP1 was assessed using membrane vesicles. Membrane vesicles prepared from ATL cells with high expression of MRP1 mRNA showed a higher ATP-dependent leukotriene C(4) uptake than did those with low expression of MRP1 mRNA. This uptake was almost completely inhibited by LTD(4) antagonists ONO-1078 and MK571. In acute- and lymphoma-type ATL, high expression of MRP1 mRNA at diagnosis correlated with shorter survival, and Cox regression analysis revealed that MRP1 expression was an independent prognostic factor. These findings suggest that functionally active MRP1 is expressed in some ATL cells and that it is involved in drug resistance and has a possible causal relationship with poor prognosis in ATL. Multidrug resistance-reversing agents, such as ONO-1078 and MK571, that directly interact and inhibit the transporting activity of MRP1 may be useful for treating ATL patients.     

Modulation by Divalent Cations of GABAρ1 Receptor From Human Retina Expressed in Xenopus Oocytes

ＩＮＴＲＯＤＵＣＴＩＯＮγ ａｍｉｎｏｂｕｔｙｒｉｃａｃｉｄ (ＧＡＢＡ)ｆｕｎｃｔｉｏｎｓａｓａｎｉｎｈｉｂｉｔｏｒｙｎｅｕｒｏｔｒａｎｓｍｉｔｔｅｒｉｎｔｈｅｍａｍ ｍａｌｉａｎｃｅｎｔｒａｌｎｅｒｖｏｕｓｓｙｓｔｅｍ .Ｉｎｉｔｉａｌｌｙ,ＧＡＢＡｒｅｃｅｐｔｏｒｓｗｅｒｅｄｉｖｉｄｅｄｉｎｔｏｔｗｏｗｅｌｌ ｃｈａｒａｃ ｔｅｒｉｚｅｄｒｅｃｅｐｔｏｒｔｙｐｅｓ,ＧＡＢＡＡａｎｄＧＡＢＡＢｒｅｃｅｐｔｏｒｓ.Ａｔｈｉｒｄｔｙｐｅｗａｓｄｉｓｃｏｖｅｒｅｄｉｎｂｒａｉｎａｎｄｒｅｔｉｎａ,ａｎｄｗａｓ…     

^32P局部照射预防猪冠状动脉再狭窄研究

目的：评价^32P灌注球囊预防再狭窄的有效性、可行性和安全性。方法：对猪冠状动脉左前降支行过度球囊扩张术后,治疗组以^32P作血管内照射,对照组作假照射。术后35d收获目标血管、检测血管形态、细胞增殖百分比等。结果：治疗组血管腔面积较对照组明显增大（P＜0．01）,新生内膜面积、血管狭窄程度和各层PCNA阳性细胞明显减小（P均＜0．01）。结论：^31P灌注球囊照射预防冠状动脉再狭窄有效、安全而且可行。     

牛心包脱细胞基质的研制

目的为组织工程学方法研制生物瓣提供适合的基质材料。方法用去污剂-酶联合四步法脱除牛心包组织中的细胞,并对处理后组织的理化性质进行分析、测试。结果脱细胞效果良好,且能较好地保持胶原纤维和弹性纤维的排列分布。脱细胞后的牛心包组织的厚度、抗拉负荷、抗拉强度、断裂伸长率和热皱缩温度无明显变化。组织中可溶性蛋白含量无显著变化,而作为结构成分的胶原蛋白和蛋白聚糖得到了较好的保存。结论去污剂-酶联合四步法能有效地制造牛心包脱细胞基质材料。