Lipofectin介导tk基因转移使B16细胞获得对GCV的敏感性

用Ｌｉｐｏｆｅｃｔｉｎ将真核表达质粒ｐＣＭＶ－ＨｙｇｒｏＴＫ导入小鼠黑色素瘤细胞系Ｂ１６，用潮霉素Ｂ筛选出阳性克隆。聚合酶链式反应检测ｔｋ基因的存在，并在倒置显微镜下动态观察了核苷类似物丙氧乌苷（ＧＣＶ）对ｔｋ￣－和ｔｋ￣＋的Ｂ１６细胞的作用。结果表明，ｔｋ￣＋的Ｂ１６细胞获得了对ＧＣＶ的敏感性，ｔｋ基因／ＧＣＶ使细胞死亡具有“旁观者效应”。     

Efficacy and Safety of Valganciclovir vs. Oral Ganciclovir for Prevention of Cytomegalovirus Disease in Solid Organ Transplant Recipients

We compared the efficacy and safety of valganciclovir with those of oral ganciclovir in preventing cytomegalovirus (CMV) disease in high-risk seronegative solid organ transplant (SOT) recipients of organs from seropositive donors (D+/R-). In this randomised, prospective, double-blind, double-dummy study, 364 CMV D+/R- patients received valganciclovir 900 mg once daily or oral ganciclovir 1000 mg three times a day (tid) within 10 days of transplant and continued through 100 days. CMV disease, plasma viremia, acute graft rejection, graft loss and safety were analyzed up to 6 and 12 months post-transplant. Endpoint committee-defined CMV disease developed in 12.1% and 15.2% of valganciclovir and ganciclovir patients, respectively, by 6 months, though with a difference in the relative efficacy of valganciclovir and ganciclovir between organs (i.e. an organ type-treatment interaction). By 12 months, respective incidences were 17.2% and 18.4%, and the incidence of investigator-treated CMV disease events was comparable in the valganciclovir (30.5%) and ganciclovir (28.0%) arms. CMV viremia during prophylaxis was significantly lower with valganciclovir (2.9% vs. 10.4%; p=0.001), but was comparable by 12 months (48.5% valganciclovir vs 48.8% ganciclovir). Time-to-onset of CMV disease and to viremia were delayed with valganciclovir; rates of acute allograft rejection were generally lower with valganciclovir. Except for a higher incidence of neutropenia with valganciclovir (8.2%, vs 3.2% ganciclovir) the safety profile was similar for both drugs. Overall, once-daily oral valganciclovir was as clinically effective and well-tolerated as oral ganciclovir tid for CMV prevention in high-risk SOT recipients.     

Ganciclovir mediated regression of rat brain tumors expressing the herpes simplex virus thymidine kinase imaged by magnetic resonance

Summary Using a rat C6 brain tumor model, we studied the antitumor effects of Herpes simplex virus type 1 thymidine kinase (HSV-tk) gene transfer followed by ganciclovir treatment. C6 glioma cells were transfectedin vitro with the HSV-tk gene, and tested for their sensitivity to ganciclovir. Although there was no surviving cell at a 30 M ganciclovir concentration, unmodified C6 cells were not affected by the drug. Forin vivo experiments, intracerebral tumors were induced in rats by stereotactic injection of 10⁴ HSV-tk-modified C6 cells. Ten days later, the animals were treated with intraperitoneal injections of ganciclovir for 21 days. The tumors evolution was evaluated by high resolution magnetic resonance imaging. In 33% of the rats, the signal intensity of the tumors became heterogeneous, with development of highly hyperintense areas, and a complete tumor regression was subsequently noted. Histological examination of successfully treated tumors revealed progressive necrosis with formation of cysts. The survival time of the HSV-tk/ganciclovir treated animals was consistently increased, all rats surviving more than 30 days and 33% of them being still alive after 80 days.     

Recurrent cytomegalovirus colitis with megacolon in an immunocompetent elderly man

Gastrointestinal infection with cytomegalovirus (CMV) is uncommon in immunocompetent hosts. The case of a 70‐year‐old male with CMV colitis, who has no history of chronic inflammatory bowel disease or immunodeficiency is described. Diagnosis was aided by the identification of inclusion bodies that reacted positively for CMV by immunohistochemical testing in biopsy specimens from the colonic mucosa. His hospital course was characterized by poor improvement of his symptoms after the CMV infection was treated with ganciclovir, and the occurrence of megacolon. A repeat colonoscopy with biopsy revealed a recurrence of the CMV infection. Although CMV colitis is common in immunocompromised patients, we believe this is the first case of CMV colitis with megacolon and recurrent CMV infection in an immunocompetent patient. Colitis caused by CMV colitis should be considered in elderly people with diarrhea. J. Med. Virol. 82:638–641, 2010. © 2010 Wiley‐Liss, Inc.     

The efficacy and safety of valganciclovir vs. oral ganciclovir in the prevention of symptomatic CMV infection in children after solid organ transplantation

Lapidus‐Krol E, Shapiro R, Amir J, Davidovits M, Steinberg R, Mor E, Avitzur Y. The efficacy and safety of valganciclovir vs. oral ganciclovir in the prevention of symptomatic CMV infection in children after solid organ transplantation.
Pediatr Transplantation 2010: 14:753–760. © 2010 John Wiley & Sons A/S. Abstract: Routine prophylaxis for CMV with valganciclovir is common in adult recipients but data to support its use in children are scarce. The aim of this study was to compare the efficacy and safety of valganciclovir vs. ganciclovir in a pediatric cohort. We performed a retrospective analysis of 92 children after KTx and/or LTx. All children have received IV ganciclovir for two wk, and then oral ganciclovir (TID; n = 41) before 2004, or valganciclovir (OD; n = 51) thereafter. Treatment was given for three months in R+/D+ or R+/D− recipients and for six months in R−/D+. Patients were followed for one yr post transplant. Both groups were comparable in their demographic and transplant‐related history. Symptomatic CMV infection/disease developed in 13.7% vs. 19.5% of valganciclovir and ganciclovir groups, respectively (P‐NS). Time‐to‐onset of CMV infection was comparable in both groups (P‐NS); rates of acute allograft rejection were similar in both groups (3.9% vs. 9.8%). Risk factors for CMV infection included young age, serostatus of R−/D+, and allograft from cadaver donor. No significant side effects were noted in both groups. As in adults, valganciclovir appears to be as efficacious and safe as oral ganciclovir. Valganciclovir should be considered as a possible prophylactic treatment for CMV in pediatric recipients of KTx or LTx.     

Cytomegalovirus following stem cell transplantation: from pharmacologic to immunologic therapy

Human cytomegalovirus is a large DNA virus that is well-equipped to evade both innate and adaptive host immune responses and to establish lifelong latency. It is a major opportunistic pathogen in immunocompromised hosts. Following allogeneic transplantation, immune responses are often inadequate to inhibit viral reactivation, resulting in progressive tissue damage, manifesting as overt human cytomegalovirus disease that usually presents as pneumonitis, colitis or hepatitis. Currently available antiviral pharmacotherapies are limited by toxicities if used prophylactically, and by a lack of efficacy in established human cytomegalovirus disease. Efforts have therefore focused on molecular diagnostic surveillance protocols that allow earlier intervention and the development of adoptive immunotherapeutic strategies to hasten host immune reconstitution.     

高效液相色谱法测定更昔洛韦凝胶的含量

目的：建立测定更昔洛韦凝胶含量的高效液相色谱法。方法：以迪马C18为色谱柱．甲醇-水（10：90）为流动相，检测波长252nm。结果：更昔洛韦在2．5～40mg·L^-1浓度范围内线性关系良好（r=0．9998），平均回收率为100．5％，RSD为0．21％。结论：本方法简便、快速、灵敏，可作为该制刺的质量控制。     

HHV-6-related secondary graft failure following allogeneic bone marrow transplantation

We report the case of an 11-year-old boy who underwent allogeneic bone marrow transplantation (BMT) for relapsed acute lymphoblastic leukaemia. Despite adequate engraftment, on day 45 he developed marrow aplasia with haemophagocytosis. HHV-6 was detected in blood and bone marrow by nested PCR. Retrospective testing showed that viraemia had started on day 24. Following therapy with foscarnet and ganciclovir, viral load declined to undetectable levels and his donor marrow recovered contemporaneously. This case suggests that HHV-6 may be a treatable cause of graft failure following BMT and provides clinical and virological evidence for the anti-HHV-6 activity of ganciclovir and foscarnet.     

Cytomegalovirus drug resistance and clinical implications

Antiviral agents are commonly used for cytomegalovirus (CMV) prophylaxis or therapy after solid organ transplantation. Until recently, the detection of drug-resistant CMV in this setting was rare, but ganciclovir resistance has now been reported to occur in 5–10% of high-risk patient subsets, such as those undergoing primary CMV infection. Persistent viral shedding or progressive CMV disease after several weeks of antiviral therapy may indicate a problem with drug resistance, though laboratory testing is required to confirm this. Rapid genotypic assays for specific mutations in the viral UL97 phosphotransferase or UL54 DNA polymerase genes can be used to detect resistance and predict cross-resistance to other drugs. The emergence of drug resistance may be reduced by optimization of host immunity, use of potent antiviral drug regimens, and adherence to dosing regimens that adequately suppress viral replication.