RNAi抑制PI3Kp85α蛋白活性对人乳腺癌细胞系MCF-7生长抑制的体外研究

目的:探讨敲低PI3Kp85α表达对人乳腺癌细胞系MCF-7细胞生长的影响和机制.方法:用靶向PI3Kp85α的siRNA转染人乳腺癌细胞系MCF-7,使用Real-time PCR法鉴定转染PI3Kp85α表达水平;MTT法评价PI3Kp85α siRNA对乳腺癌细胞系MCF-7生长的影响;流式细胞术检测转染后细胞周期分布和凋亡;采用免疫荧光染色及Western blot方法观察IA型PI3K/AKT通路主要成员的表达.结果:Real-timePCR结果显示PI3Kp85α siR-NA转染导致PI3Kp85α表达下调;MTT结果显示PI3Kp85α siRNA转染抑制肿瘤细胞生长;流式细胞术检测可见PI3Kp85α siRNA转染组细胞周期存在G_0/G_1期阻滞而且凋亡率显著高于对照组与空载体组(F=19.255,P=0.002).结论:应用PI3Kp85α siRNA转染人乳腺癌细胞系MCF-7细胞,可抑制其增殖和诱导细胞凋亡,因此PI3Kp85α可以作为人乳腺癌基因治疗的候选靶点.     

Upregulation of hyaluronan and its binding receptors in an experimental model of chronic cyclosporine nephropathy

Aim: Hyaluronan (HA) is an important extracellular matrix (ECM) proteoglycan. The localization of HA and its binding receptors, CD44 and LYVE‐1, was evaluated in an experimental model of chronic cyclosporine A (CsA)‐induced nephropathy. Methods: Sprague–Dawley rats maintained on a low‐salt diet (0.05% sodium) received an s.c. injection of vehicle (1 mL/kg per day olive oil; VH groups) or CsA (15 mg/kg per day; CsA groups) for 1 or 4 weeks. Induction of chronic CsA nephropathy was evaluated according to renal function and pathology and expression of HA, CD44, LYVE‐1, ED‐1 and α‐smooth muscle actin (α‐SMA). Results: CsA treatment for 4 weeks caused renal dysfunction, which was accompanied by typical striped interstitial fibrosis. In the VH group, HA immunoreactivity was observed only in the inner medulla. However, the area of HA immunoreactivity increased with the duration of CsA treatment: CsA treatment for 1 week extended HA immunoreactivity to the outer medulla, and CsA treatment for 4 weeks caused a further extension of HA immunoreactivity to the cortex, which was vulnerable to CsA‐induced renal injury. HA binding receptor, CD44 and LYVE‐1 expression were also upregulated in the CsA groups, and were localized to the area of fibrosis and the peritubular capillaries of the cortex. In the CsA groups, ED‐1 and α‐SMA were predominantly expressed in fibrotic areas in which HA had accumulated. Conclusion: These findings suggest that upregulation of HA and its binding receptors are involved in interstitial fibrosis in chronic CsA‐induced renal injury.     

Is interval from an initial biopsy a significant predictor of prostate cancer at repeat biopsies?

BACKGROUND: Currently, there are no clear criteria for indicating repeat biopsies in patients with negative results at an initial biopsy of the prostate. The aim of the present study is to determine the clinical and pathological parameters which predict prostate cancer at repeat biopsies with special attention to the interval between biopsies in addition to prostate specific antigen (PSA) and its derivatives. METHODS: We reviewed 100 patients who underwent an initial biopsy that proved negative for prostate cancer and required repeat biopsies between November 1996 and November 2003. Clinical parameters such as age, PSA and its derivatives, interval between biopsies, number of cores taken and initial biopsy histology were analyzed. RESULTS: In total, 31 patients (31.0%) were found to have prostate cancer, 18 (25.7%) of 70 patients by the second biopsy and 13 (46.4%) of 28 patients by the third biopsy. Two patients underwent the fourth biopsy, which revealed no prostate cancer. The patients with a positive biopsy had a significantly longer interval between the biopsies than the patients with a negative biopsy (P=0.0036). Furthermore, in both univariate and multivariate logistic regression analysis, only the interval between the biopsies proved to be an independent predictor of positive results at repeat biopsies (P=0.0094 and 0.0019). CONCLUSIONS: Only the biopsy interval was a significant predictor of prostate cancer at repeat biopsies in both univariate and multivariate analysis.     

Radio-frequency ablation of renal cell carcinoma in patients who were at significant risk

OBJECTIVE: Although radio-frequency ablation (RFA) has been recently applied as a minimally invasive treatment option for renal cell carcinoma (RCC), indication of this modality remains a critical issue due to the lack of complete tumor destruction as well as the uncertainty of its long-term efficacy. We report the efficacy of RFA for nine carefully selected patients with RCC who had significant reason to avoid invasive surgical treatment under general anesthesia. METHODS: Radio-frequency ablation was performed under epidural or local anesthesia by ultrasound or computed tomography (CT) guidance in nine patients with biopsy proven RCC (mean diameter, 38 mm; range, 20-53 mm), who were at significant operative or anesthetic risk for invasive surgery. Follow-up enhanced CT scans or magnetic resonance images were evaluated every 3-6 months and an evaluation of metastasis was performed every 6 months. RESULTS: At a mean follow-up of 17 months, seven (78%) of the nine patients with renal tumor showed no tumor enhancement. The renal function of all patients was well preserved. All patients were able to continue undergoing their respective treatments for active diseases in other organs in parallel to the RFA treatment. No distant metastasis, urine leakage were reported and one case of temporary hematuria and one case of peri-renal hemorrhage not requiring blood transfusion were encountered. Intra-operative ultrasonography was useful in the real-time monitoring of the minimally excessive extension of ablation into the normal parenchyma. CONCLUSION: Radio-frequency ablation appears to be an effective and safe minimally invasive therapeutic option for selected patients with RCC who have reason to avoid invasive surgery under general anesthesia.     

Cancer Prevention through Legislation-Hong Kong Experience

Cancer is the major cause of death worldwide and in the local community. Due to the aging population and changes in lifestyle of the citizens, it is expected that the incidence of cancer will continue to increase. In fact, according to the World Health Organization, about 30% of cancer death can be prevented. The fight against cancer relies on support from the government, together with collaborations with the policymakers, healthcare professionals, and the public. Legislation can act as a tool for cancer prevention. The purpose of this paper is to provide an overview of the global cancer burden and to describe how cancer legislation acts as a tool for cancer prevention in the Hong Kong region.     

用放射吸收法(RA)测量指骨骨密度精确度和准确性的研究

目的 评价放射吸收法(RA)测量2、3、4指骨中节骨密度的精确度和准确性.方法 对19例尸体的双手,用铝制楔型标志物,分别进行了50 kV 400 mA和60 kV 300 mA两次X线照射,对每只手指的第二至第四节指骨的骨矿含量(BMC)和骨密度(BMD),以Au(指骨指数)为单位进行测量和分析.结果 对于BMC-AU来说,这种方法的精密度误差是1.0%,对于BMD-AU来说,精密度误差是0.6%.通过5 mm和6mm 酒精厚度所获得的X射线图可以观察到BMD-Au有2.0%到2.4%的降低,与对照组相比有明显的统计学差异(P<0.01).采用X射线吸收测定法得到的BMC-Au 和前臂的BMC有良好的相关性(r=0.887),并且在指骨的BMC-AU与骨灰重量之间也有较好的相关性(r=0.983).结论 放射吸收法(RA)测量外周骨骨密度具有较高的精确度和准确性.     

Hepatitis B and C in doctors and dentists in Nigeria

We surveyed a random sample (n = 75) of doctors and dentists at University College Hospital, Ibadan, Nigeria. They were offered anonymous testing for hepatitis B surface antigen (HBsAg), hepatitis Be antigen (HBeAG), antibodies to hepatitis B core antigen (anti-HBc) and to hepatitis C virus (anti-HCV), by enzyme immunoassay. The results suggest a high prevalence of hepatitis B virus (HBV) with a high potential of transmissibility, as well as a high prevalence of HCV infection. The majority of the doctors and dentists use universal precaution for protection against viral hepatitis on < 50% of the occasions when they carry out procedures on their patients. Infection with HBV was associated with type of specialty (surgeons, dentists) and lack of HBV vaccination (p < 0.05). After logistic regression, these factors were independently associated with HBV infection (p < 0.05). Sixty (80%) had not received prior HBV vaccination. Unvaccinated personnel were more likely to be surgeons, dentists, < 37 years of age, and have fewer years of professional activity (p < 0.05). After logistic regression, only fewer years of professional activity remained independently associated with lack of vaccination (p < 0.05). To reduce the occupational exposure of HBV, universal precautions must be rigorously adhered to when the doctors and dentists carry out procedures on their patients, and all health-care workers should be vaccinated with HBV vaccine and the HCV vaccine, when it becomes available.      

黄芩汤及其肠道菌群的代谢产物对D-半乳糖胺诱导的肝损伤的保护作用的比较研究

目的 :对黄芩汤及其经肠道菌群作用后的代谢产物的体内保肝作用进行比较研究。方法 :使用普通和伪无菌小鼠 ,用D-半乳糖胺造成肝脏损伤模型 ,分别给予黄芩汤和黄芩汤的代谢产物 ,测定给药 3d后血清中丙氨酸氨基转换酶 (ALT)和天门冬氨酸氨基转换酶 (AST)的活性。结果 :普通小鼠口服黄芩汤后 ,高、中剂量组小鼠血清中ALT水平明显下降 ,与模型组产生显著差异 ;伪无菌小鼠口服黄芩汤代谢产物之后 ,高、中剂量组血清中ALT水平显著下降 ,但黄芩汤 3个剂量组对其无相似的药理作用。结论 :黄芩汤经过肠道菌群作用后的代谢产物是体内产生保肝降酶作用的物质基础。