丙型肝炎病毒Simmonds基因分型法酶切分型的研究

丙型肝炎病毒（HCV）的基因分型在临床和流行病学的研究方面有重要意义。以多聚酶链反应的方法扩增HCV的5’-非编码区第28至284区段（HCV－J株），并以复合限制性内切酶水解的方法按Simmonds基因分型的标准，将HCV分为6型和若干亚型。结果：检测标本38份，均为1b型，与以往的检测结果类似。

HCV-1b型NS5A区准种变异与干扰素疗效关系的研究

目的：研究丙型肝炎病毒基因1b（HCV－1b）NS5A区准种变异与干扰素疗效的关系。方法：选取HCV一1b型慢性丙型肝炎患者20例，在干扰素治疗前作NS5A区准种变异等测定，并比较其与干扰素疗效的关系。结果：10例干扰素治疗有效组的单链构象多肽性（SSCP）大部分表现为2带（6例），少部分为3带（4例），平均为2．4带；而10例干扰素治疗无效组的SSCP大部分表现为3带（6例），少部分为4带（4例），平均为3．4带。两者比较有极显著差异。结论：干扰素的疗效与NS5A准种变异密切相关，有效组准种变异的程度明显低于无效组，即病人治疗前HCV准种变异较少者，HCV病毒易于被清除。采用SSCP检测HCV－NS5A准种变异以预测丙型肝炎干扰素疗效有一定的实用价值。

湖羊蛋白酶遗传型结构及系统地位的研究

用“中心产区典型群随机抽样”的方法 ,对湖羊品种进行遗传检测。在所检测的 12个位点中的 11个 (Alb、Tf、Alp、L ap、Ary- Es、Hb- β、X- p、CA、Cat、L y和 Ke)具有多态性 ,仅 Po位点为单态 ,多态座位比例为 91.6 7% ,在 2 7个等位基因中 ,只有 Po F、Tf A、Tf F、Hb- βA、CAF 和 Ke L 的估计可靠程度分别为 0 .5 2 2 2 ,0 .74 5 8,0 .5 2 2 2 ,0 .6 2 12 ,0 .8990和 0 .90 70外 ,其余 2 1个等位基因估计可靠程度均在 0 .95 45以上。说明“中心产区典型群随机抽样”在特定遗传背景下是一种有效的抽样方法。湖羊的平均杂合度比国内其他绵羊种群偏低 ,而与国外其他群体相比 ,平均纯合度偏低。引用国内外 14个绵羊群体的相同资料 ,根据血液酶和其他蛋白质变异的 10个基因座位共计 33个等位基因的频率 ,进行系统聚类分析 。

侵袭性脑膜瘤的影像学特征与手术策略

目的探讨侵袭性脑膜瘤的影像特征和手术治疗方法。方法回顾性分析56例侵袭性脑膜瘤患者的临床表现、影像学检查、病理结果及手术治疗情况等资料。结果56例侵袭性脑膜瘤在影像学上表现有颅骨的局部增生(18例),肿瘤侵蚀破坏颅骨(11例),硬脑膜"尾"征(27例),瘤-脑界面部分或完全消失(29例),肿瘤边界毛糙模糊、结节状或指状突出、伪足征(24例),肿瘤粘附或侵入静脉窦或海绵窦(9例),包绕大血管4例,瘤周明显水肿(39例)等。手术切除按Simpson标准分级,其中0级21例,Ⅰ级19例;Ⅱ级9例,Ⅲ级7例。术后随访0.5～8年,痊愈49例,轻度功能障碍7例。无死亡病例,复发4例。结论侵袭性脑膜瘤有较特殊的影像学特征,可为临床诊断和手术治疗提供参考。尽可能地行病灶根治性切除能有效地减少肿瘤的复发。

赖型钩体pD C 38核酸序列测定及其与流感伤寒型钩体外膜蛋白基因om pL 1核酸序列的类似性匹配

为了探讨赖型钩体 ｐ Ｄ Ｃ３８ 插入片段基因组 Ｄ Ｎ Ａ 编码、位置与ｏｍ ｐ Ｌ１ 基因的关系，作者采用在流感伤寒型钩体外膜蛋白基因ｏｍ ｐ Ｌ１ 首尾区段设计一对引物，以 ｐ Ｄ Ｃ３８ 插入片段作模板进行 Ｐ Ｃ Ｒ 扩增、测定和类似性匹配（ａｌｉｇｎｍ ｅｎｔ）。结果发现：ｐ Ｄ Ｃ３８ 含有 ２．７ｋｂ 和３．０ｋｂ 两个插入片段，３．０ｋｂ 片段含有 １ 个ｏｍ ｐ Ｌ１ 基因全拷贝。结论：类似性匹配表明，ｐ Ｄ Ｃ３８ 和ｏｍ ｐ Ｌ１ 相同碱基８６４ 个（９０％ ），碱基变异（不配对）９６（１０％ ）个， ｐ Ｄ Ｃ３８ 可用于钩体诊断、分类、鉴定、疫苗和发病机理的研究。

硫唑嘌呤治疗重症肌无力副作用的研究

本文报告应用硫唑嘌呤治疗重症肌无力的副作用。重症肌无力患者224例，出现副作用者68例，其发生率为30．4％，其中胃肠道副作用和肝功能损害最常见，分别为33．8％（23／68）和27．9％（19／68）。副作用的发生与发病年龄、病程、用药剂量、用药时间及是否与肾上腺皮质激素合用等无关，主要取决于个体差异。因此笔者提出临床用药应从小剂量开始，逐渐增加，争取以最小的剂量取得最佳效果。

Levels of vasoactive intestinal peptide,cholecystokinin and calcitonin gene-related peptide in plasma and jejunum of rats following traumatic brain injury and underlying significance in gastrointestinal dysfunction

AIM:To study the alterations of brain-gut peptides following traumatic brain injury (TBI) and to explore the underlying significance of these peptides in the complicated gastrointestinal dysfunction.METHODS:Rat models of focal traumatic brain injury were established by impact insult method,and divided into 6 groups (6 rats each group) including control group with sham operation and TBI groups at postinjury 3,12,24,72h,and d 7.Blood and proximal jejunum samples were taken at time point of each group and gross observations of gastrointestinal pathology were recorded simultaneously.The levels of vasoactive intestinal peptide (VIP) in plasma,calcitonin gene-related peptide (CGRP) and cholecystokinin (CCK) in both plasma and jejunum were measured by enzyme immunoassay (EIA). Radioimmunoassay (RIA) was used to determine the levels of VIP in jejunum.RESULTS:Gastric distension,delayed gastric emptying and intestinal dilatation with a large amount of yellowish effusion and thin edematous wall were found in TBI rats through 12h and 72h, which peaked at postinjury 72h. As compared with that of control group (247.8±29.5ng/L), plasma VIP levels were significantly decreased at postinjury 3,12 and 24h (106.7±34.1ng/L, 148.7±22.8ng/L,132.8±21.6ng/L,respectively),but significantly increased at 72h (405.0±29.8ng/L) and markedly declined on d 7 (130.7±19.3ng/L).However,Plasma levels CCK and CGRP were significantly increased through 3h and 7d following TBI (126-691% increases),with the peak at 72 h.Compared with control (VIP, 13.6±1.4ng/g;CGRP,70.6±17.7ng/g);VIP and CGRP levels in jejunum were significantly increased at 3h after TBI (VIP,35.4±5.0ng/g;CGRP,103.8±22.1ng/g),and declined gradually at 12 h and 2d h (VIP,16.5±1.8ng/g,5.5±1.4ng/g;CGRP,34.9±9.7ng/g, 18.5±7.7ng/g),but were significantly increased again at 72 h (VIP, 48.7±9.5ng/g; CGRP,142.1±24.3ng/g),then declined in various degrees on d 7 (VIP, 3.8±1.1ng/g; CGRP, 102.5±18.1ng/g).The CCK levels in jejunum were found to change in a similar trend as that in plasma with the concentrations of CCK significantly increased following TBI (99-517% increases) and peaked at 72h.CONCLUSION:Traumatic brain injury can lead to significant changes of brain-gut peptides in both plasma and small intestine, which may be involved in the pathogenesis of complicated gastrointestinal dysfunction.

Different approaches to caudate Iobectomy with"curettage and aspiration"technique using a special instrument PMOD:A Report of 76 cases

AIM:To study different approaches to caudate Iobectomy with'curettage and aspiration'technique using Peng's multifunctional operative dissector(PMOD).The surgical procedure of isolated complete caudate Iobectomy was specially discussed. METHODS:In 76 cases of various types of caudate Iobectomy,three approaches were used including left side approach,right side approach,and anterior approach. Among the 76 cases,isolated complete caudate Iobectomy was carried out in 6 cases with transhepatic anterior approach.The surgical procedure consisted of mobilization of the total liver,ligation and separation of the short hepatic veins,splitting the liver parenchyma through the Cantlie's plane,ligation and division of the caudate portal triads from the hilum,dissection of the root of major hepatic veins, detachment of the caudate lobe from liver parenchyma. RESULTS:The mean operative time was 285±51 min, the mean blood loss was 1 600 ml.No severe complications were observed.Among the 6 cases receiving isolated complete caudate lobectomy with transhepatic anterior approach,one case died 17 months after operation due to disease recurrence and liver failure,the other 5 cases have been alive without recurrence,with one longest survival of 49 months. CONCLUSION:The choice of approach is essential to the success of caudate Iobectomy.As PMOD and'curettage and aspiration'technique can delineate intrahepatic or extrahepatic vessels clearly,caudate lobe resection has become safer,easier and faster.

ATM and ATR:Sensing DNA damage

Cellular response to genotoxic stress is a very complex process, and it usually starts with the “sensing” or “detection” of the DNA damage,followed by a series of events that include signal transduction and activation of transcription factors.The activated transcription factors induce expressions of many genes which are involved in cellular functions such as DNA repair,cell cycle arrest,and cell death. There havebeen extensive studies from multiple disciplines exploring the mechanisms of cellular genotoxic responses, which have resulted in the identification of many cellular components involved in this process,including the mitogen-activated protein kinases (MAPKs) cascade. Although the initial activation of protein kinase cascade is not fully understood,human protein kinases ATM (ataxia-telangiectasia, mutated) and ATR (ATM and Rad3-related) are emerging as potential sensors of DNA damage. Current progresses in ATM/ATR research and related signaling pathways are discussed in this review, in an effort to facilitate a better understanding of genotoxic stress response.

Effect of hepatitis Bimmunoglobulin on interruption of HBV intrauterine infection

AIM: To evaluate the efficacy of hepatitis B immunoglobulin (HBIG) in interrupting hepatitis B virus (HBV) intrauterine infection during late pregnancy.METHODS: We allocated 112 HBsAg positive pregnant women into 2 groups randomly. Fifty seven cases in th HBIG group received 200 IU (unit) HBIG intramuscularly every 4 wk from the 28 wk of gestation to the time of delivery, while 55 cases in the control group received no special treatment. HBsAg, HBeAg, HBcAb, HBeAb, HBsAb and HBV DNA levels were tested in the peripheral blood specimens from all of the mothers at 28 wk of gestation, just before delivery, and in blood from their newborns within 24 h before administration of immune prophylaxis.RESULTS: The intrauterine infection rate in HBIG group and control group were 10.5% and 27.3%, respectively, with significant difference (P<0.05). It showed ascendant trend as HBV DNA levels in the peripheral blood increased before delivery.CONCLUSION: HBIG is potent to cut down HBV intrauterine infection rate significantly when administered to pregnant women regularly during late pregnancy. The possibility of HBV intrauterine infection increases if maternal blood HBV DNA≥10^8 copies/mL.

Down-modulation of heat shock protein 70 and up-modulation of Caspase-3 during schisandrin B-induced apoptosis in human hepatoma SMMC-7721 cells

AIM: To investigate the effect of schisandrin B (Sch B) on proliferation and apoptosis of human hepatoma SMMC-7721 cells in vitro and regulation of Hsp70 and Caspases-3, 7, 9 expression by Sch B. METHODS: Human hepatoma cell line SMMC-7721 was cultured and treated with Sch B at various concentrations. Growth suppression was detected with MTT colorimetric assay. Cell apoptosis was confirmed by DNA ladder detection and flow cytometric analysis. The expression of Hsp70, Caspases-3, 7, 9 were analyzed by Western blot analysis. RESULTS: Sch B inhibited the growth of hepatoma SMMC-7721 cells in a dose-dependent manner, leading to a 50% decrease in cell number (LC50) value of 23.50 mg/L. Treatment with Sch B resulted in degradation of chromosomal DNA into small internucleosomal fragments, evidenced by the formation of a 180-200 bp DNA ladder on agarose gels. FCM analysis showed the peak areas of subdiploid at the increased concentration of Sch B. The results of Western bolt analysis showed that Hsp70 was down-regulated and Caspase-3 was up-regulated, while the activity of Caspases-7,-9 had no significant change. CONCLUSION: Sch B is able to inhibit the proliferation ofhuman hepatoma SMMC-7721 cells and induce apoptosis, which goes through Caspase-3-dependent and Caspase-9-independent pathway accompanied with the down-regulation of Hsp70 protein expression at an early event.

Effect of androgen deprivation on penile ultrastructure

<abstract>Aim: To investigate the ultrastructural changes of penile corpus cavernosum and tunica albuginea in rats treated with castration or finasteride. Methods: Eighteen male Sprague-Dawley rats of nine weeks old were randomly divided into three groups with 6 rats each. Group A served as the control, Group B was castrated and Group C, treated with finasteride. Four weeks later, rats were anesthetized and blood samples obtained for the determination of serum testosterone (T) and dihydrotestosterone (DHT) levels; penile tissues were taken for scanning electron microscopy. Results: The T, free T and DHT levels in Group B and the DHT level in Group C were significantly lower than those in Group A (P<0.05). The tunica albuginea was significantly thinner in Group B than that in Group A (P<0.05), but there was no significant difference between Group C and Group A (P>0.05). Elastic fibers in the tunica albuginea of Group A were very rich and arranged regularly and undulatedly, but in Group B, most of the elastic fibers were replaced by collagenous fibers. In Group C, the tunica albuginea was mainly composed of thick and irregular-arranged collagenous fibers. In Group A, there were abundant smooth muscle fibers in the trabeculae of corpus cavernosum, but they were much less in Group C and scarce or even disappeared in Group B. In Groups B and C, the diminished/disappeared smooth muscle fibers were replaced by irregularly arranged collagenous fibers. Conclusion: In rats, androgen is essential for maintaining the normal structure of penile tunica albuginea and corpus carvenosum.

Alteration of cyclin D1 in gastric carcinoma and its clinicopathologic significance

AIM: To detect the genetic alteration and abnormal expression of cyclin D1 in gastric carcinoma and investigate its clinicopathologic significance in advanced gastric carcinoma. METHODS: Proteins of cyclin D1 were detected by immunohistochemistry in 42 cases of advanced gastric carcinoma with their follow-up data available, 27 cases of early stage carcinoma, 21 cases of gastric adenoma, 22 cases of hyperplastic polyp and 20 cases of normal mucosa adjacent to adenocarcinomas. Genetic alteration of cyclin D1 was detected by Southern blot and expression of cyclin D1 mRNA was detected by PT-PCR in 42 cases of advanced gastric carcinoma. RESULTS: Cyclin D1 protein was not expressed in normal mucosa, hyperplastic polyp and gastric adenoma, while it was only positively expressed in gastric carcinoma. The expression rate of cyclin D1 protein in early stage gastric carcinoma, advanced gastric carcinoma and lymph node metastasis was 48.1%, 47.4% and 50.0%, respectively. The amplification of cyclin D1 gene was detected in 16.6% of advanced gastric carcinomas. The overexpression of cyclin D1 mRNA was detected in 40.5% of the samples. There was no significant correlation between cyclin D1 protein expression and age, lymph-node metastasis and histological grading in patients with advanced gastric carcinoma (x^2=0.038,0.059,0.241, P>0.05). Significant correlation was observed between the expression of cyclin D1 protein and the 5-year survival rate (x^2=3.92, P<0.05). CONCLUSION: Detection of cyclin D1 protein by immunohistochemistry may be useful in the diagnosis of early gastric carcinomas. Patients with positive expression of cyclin D1 protein tend to have a worse prognosis.

Metabolic syndrome is directly associated with gamma glutamyl transpeptidase elevation in Japanese women

AIM:This study aimed to determine whether metabolic syndrome is directly or indirectly,through fatty liver,associated with elevated gamma-glutamyl transpeptidase (GGT) levels in Japanese women. METHODS:From 4 366 women who received their annual health check-up,4 211 women were selected for analysis. All 4 211 women were negative for both hepatitis B surface antigen and antibody to hepatitis C virus.Clinical and biochemical variables were examined by using univariate and multivariate analysis. RESULTS:A raised GGT level (>68 IU/L) was seen in 258 (6.1%) of the 4 211 women.In univariate analysis,all variables examined (age,body mass index,blood pressure, hemoglobin concentration,fasting blood glucose, glycosylated hemoglobin Alc,cholesterol,triglyceride,and uric acid) were associated with the elevated GGT level, whereas in multivariate analysis,four variables (age≧50 yr, hemoglobin≧14 g/dL,triglyceride≧150 mg/dL,and presence of diabetes) were significantly and independently associated with raised GGT level.Clinical variables predicting the presence of ultrasonographic evidence of fatty liver were also examined by multivariate analysis;four variables were associated with the presence of fatty liver:BMI≧25 kg/m^2, hemoglobin≧14 g/dL,triglyceride≧150 mg/dL,and uric acid ≧ 7 mg/dL.There was no significant association between the raised GGT level and the presence of fatty liver. Hypertriglyceridemia was significantly and independently associated with both the raised GGT level and the presence of fatty liver. CONCLUSION:Metabolic syndrome seemed to be directly, not indirectly through fatty liver,associated with the raised GGT level in Japanese women.

Reg gene family and human diseases

Regenerating gene (Reg or REG) family, within the superfamily of C-type lectin, is mainly involved in the liver,pancreatic, gastric and intestinal cell proliferation or differentiation. Considerable attention has focused on Reg family and its structurally related molecules. Over the last 15 years, 17 members of the Reg family have been cloned and sequenced. They have been considered as members of a conserved protein family sharing structural and some functional properties being involved in injury, inflammation,diabetes and carcinogenesis. We previously identified Reg Ⅳ as a strong candidate for a gene that was highly expressed in colorectal adenoma when compared to normal mucosa based on suppression subtractive hybridization (SSH),reverse Northern blot, semi-quantitative reverse transcriptase PCR (RT-PCR)and Northern blot. In situ hybridization results further support that overexpression of Reg Ⅳ may be an early event in colorectal carcinogenesis. We suggest that detection of Reg Ⅳ overexpression might be useful in the early diagnosis of carcinomatous transformation of adenoma.This review summarizes the roles of Reg family in diseases in the literature as well as our recent results of Reg Ⅳ in colorectal cancer. The biological properties of Reg family and its possible roles in human diseases are discussed. We particularly focus on the roles of Reg family as sensitive reactants of tissue injury, prognostic indicators of tumor survival and early biomarkers of carcinogenesis. In addition to our current understanding of Reg gene functions, we postulate that there might be relationships between Reg family and microsatellite instability, apoptosis and cancer with a poor prognosis. Investigation of the correlation between tumor Reg expression and survival rate, and analysis of the Reg gene status in human maliganancies, are required to elucidate the biologic consequences of Reg gene expression, the implications for Reg gene regulation of cell growth, tumorigenesis, and the progression of cancer. It needs to be further attested whether Reg gene family is applicable in early detection of cancer and whether Reg and Reg-related molecules can offer novel molecular targets for anticancer therapeutics. This has implications with regard to prognosis, such as in monitoring cancer initiation,progression and recurrence, as well as the design of chemotherapeutic drugs.

Frequencies of poor metabolizers of cytochrome P450 2C19 in esophagus cancer,stomach cancer,lung cancer and bladder cancer in Chinese population

AIM: To investigate the association between cytochrome P450 2C19 (CYP2C19) gene polymorphism and cancer susceptibility by genotyping of CYP2C19 poor metabolizers (PMs) in cancer patients.METHODS: One hundred and thirty-five cases of esophagus cancer, 148 cases of stomach cancer, 212 cases of lung cancer, 112 cases of bladder cancer and 372 controls were genotyped by allele specific amplification-polymerase chain reaction (ASA-PCR) for CYP2C19 PMs. The frequencies of PMs in cancer groups and control group were compared.RESULTS: The frequencies of PMs of CYP2C19 were 34.1% (46/135) in the group of esophagus cancer patients, 31.8% (47/148) in the stomach cancer patients, 34.4%(73/212) in the group of lung cancer patients, only 4.5%(5/112) in the bladder cancer patients and 14.0%(52/372) in control group.There were statistical differences between the cancer groups and control group (esophagus cancer, X^2=25.65, P<0.005,OR=-3.18, 95%C/=2.005-5.042, stomach cancer, X^2=21.70,P<0.005, OR=2.86, 95%CI=1.820-4.501; lung cancer,X^2=33.58, P<0.005, OR=-3.23, 95%C/=1.503-6.906; bladder cancer, X^2=7.50, P<0.01, OR=-0.288, 95%C/=0.112-0.740).CONCLUSION: CYP2C19 PMs have a high incidence of esophagus cancer, stomach cancer and lung cancer, conversely they have a low incidence of bladder cancer. It suggests that CYP2C19 may participate in the activation of procarcinogen of esophagus cancer, stomach cancer and lung cancer, but may involve in the detoxification of carcinogens of bladder cancer.

Chylois ascites:Treated with total parenteral nutrition and somatostatin

AIM: To determine the effects of total parenteral nutrition and somatostatin on patients with chylous ascites.METHODS: Five patients were diagnosed with chylous ascites on the basis of laboratory findings of ascites sample from Nov 1999 to May 2003. Total parenteral nutrition and somatostatin or its analogue was administered to 4 patients,while the other one only received total parenteral nutrition.All the patients had persistent peritoneal drainage, with the quantity and quality of drainage fluid observed daily.Necessary supportive treatments were given to the patients individually during the therapy.RESULTS: Two of 4 patients who received somatostatin therapy obtained complete recovery within 10 d without any recurrence while on a normal diet. In these 2 patients,the peritoneal drainage reduced to zero in one and the other's decreased from 2 000 mL to 80 mL with a clear appearance and negative qualitative analysis of chyle. Recurrent chylous ascites, though relieved effectively by the same method every time, developed in one patient with advanced pancreatic cancer. The other patient's lymphatic fistula was blocked with the fibrin glue after conservative treatment. The patient who only received total parenteral nutrition was cured 24 d after therapy.CONCLUSION: Total parenteral nutrition along with somatostatin can relieve the symptoms and close the fistula in patients with chylous ascites rapidly. It appears to be an effective therapy available for the treatment of chylous ascites caused by various disorders.

Inhibition of human La protein by RNA interference downregulates hepatitis B virus mRNA in 2.2.15 cells

AIM: To investigate the role of human La protein in HBV mRNA expression.METHODS: Three human La protein (hLa) specific siRNA expression cassettes (SECs) containing U6+1 promoter were prepared via one-step overlapping extension PCR. After transfection with SECs into HepG2 cells, inhibition effects on hLa expression were analyzed by semi-quantitative RT-PCR and Western blotting. Then, effective SECs were screened out and transfected into 2.2.15 cells, a stable HBV-producing cell line. HBV surface antigen(HBsAg) and e antigen (HBeAg) secretions into culture media were detected by microparticle enzyme immunoassay (MEIA) and HBs and HBe mRNA levels were analyzed by semi-quantitative RT-PCR.RESULTS: SEC products containing U6+1 snRNA promoter,and 3 sites of hLa mRNA specific siRNA were obtained successfully by one-step overlapping extension PCR and could be directly transfected into HepG2 cells, resulting in inhibition of La protein expression in both mRNA and protein levels, among which U6+l-hLa833 was the most efficient,which reduced 18.6-fold mRNA and 89% protein level respectively. In 2.2.15 cells, U6+l-hLa833 was also efficient on inhibition of hLa expression. Furthermore, semi-quantitative RT-PCR showed that HI3s and HBe mRNA levels were significantly decreased by 8-and 66-fold in U6+l-hLa833 transfected cells compared to control. Accordingly, HBsAg and HBeAg secretions were decreased partly posttransfection with SECs.CONCLUSION: PCR-based SECs can be used to mediate RNAi in mammalian cells and provide a novel approach to study the function of La protein. The inhibition of La protein expression can result in a significant decrease ofHBV mRNA, which implies that the hLa protein is also involved HBV RNA metabolism as one of the HBV RNA-stabilizing factors in human cells.

Ultrastructural changes of penile tunica albuginea in diabetic rats

Aim: To clarify the ultrastructural changes of penile tunica albuginea (TA) in streptozotocin (STZ)-induced diabetic rats. Methods: Intraperitoneal injection of STZ was used to induce diabetes mellitus (DM) in 12 Sprague Dawley rats. Ten rats (age and weight-matched) were used as control. Blood samples from the tail snips of the rats were used for the determination of serum glucose levels with SureStep Plus Blood Meter. At week 4 and 10 after the injection, half of the rats in each group were sacrificed and penile samples were obtained from the middle third of the penile shaft for the examination of TA under scanning electron microscopy. Results: In the diabetic group, the serum glucose levels were higher (P<0.01 at both time points) and the TA were thinner (P<0.05) than those of the controls. In the control group, the fibers of TA were rich and arranged regularly and undulated, while in the diabetic group, the fibers were diminished, lost the undulations and were arranged irregularly. Conclusion: In rats, DM appeared to impair the penile TA ultrastructures and this impairment could contribute to diabetic erectile dysfunction in part by impairing the veno-occlusive function.

Relationship Between Microcystin in Drinking Water and Colorectal Cancer

Objective To investigate the association of microcystin (MC) in drinking water with the incidence of colorectal cancer. Methods The study was designed as a retrospective cohort. Eight townships or towns were randomly selected as the study sites in Haining City of Zhejiang Province, China. 408 cases of colon and rectum carcinomas diagnosed from 1977 to 1996 in the study sites were included, and a survey on types of drinking water of these patients was conducted. Samples of different water sources (well, tap, river and pond) were collected separately and microcystin concentrations were determined by indirect competitive ELISA method. Results The incidence rate of colorectal cancer was significantly higher in population who drank river and pond water than those who drank well and tap water. Compared to well water, the relative risk (RR) for colorectal cancer was 1.88 (tap), 7.94 (river) and 7.70 (pond) respectively. The positive rate (>50 pg/mL) of microcystin in samples of well, tap, river and pond water was 0, 0, 36.23% and 17.14% respectively. The concentration of microcystin in river and pond water was significantly higher than that in well and tap water (P<0.01). Spearman rank correlation analysis showed that in the study sites, the microcystin concentration of river and pond water was positively associated with the incidence of colorectal cancer (rs= 0.881, P<0.01). Conclusions The types of drinking water are positively associated with the incidence of colorectal cancer in the study sites, and this may be related to microcystin contamination of drinking water. Further biological study is needed to support the possible causative role of mycrocystin in carcinogenesis of colon and rectum.