A double-chamber rotating bioreactor for the development of tissue-engineered hollow organs: From concept to clinical trial

Cell and tissue engineering are now being translated into clinical organ replacement, offering alternatives to fight morbidity, organ shortages and ethico-social problems associated with allotransplantation. Central to the recent first successful use of stem cells to create an organ replacement in man was our development of a bioreactor environment. Critical design features were the abilities to drive the growth of two different cell types, to support 3D maturation, to maintain biomechanical and biological properties and to provide appropriate hydrodynamic stimuli and adequate mass transport. An analytical model was developed and applied to predict oxygen profiles in the bioreactor-cultured organ construct and in the culture media, comparing representative culture configurations and operating conditions. Autologous respiratory epithelial cells and mesenchymal stem cells (BMSCs, then differentiated into chondrocytes) were isolated, characterized and expanded. Both cell types were seeded and cultured onto a decellularized human donor tracheal matrix within the bioreactor. One year post-operatively, graft and patient are healthy, and biopsies confirm angiogenesis, viable epithelial cells and chondrocytes. Our rotating double-chamber bioreactor permits the efficient repopulation of a decellularized human matrix, a concept that can be applied clinically, as demonstrated by the successful tracheal transplantation.     

Monitoring Infection with Epstein–Barr Virus among Seromismatch Adult Renal Transplant Recipients

Patients who undergo Epstein–Barr virus (EBV) seromismatch (D+/R − ) transplants have a higher risk for the development of post‐transplant lymphoproliferative disorder (PTLD). Adult renal transplant recipients at a single institution were prospectively monitored for EBV during the first year post‐transplant. Over a 2‐year period, 34 patients (7.78%) were identified as being EBV D+/R − recipients. Patients who developed symptoms or had persistent viremia were pre‐emptively administered rituximab. Six recipients were discharged without monitoring on the protocol. Of those six, three (50%) developed PTLD and all three lost their grafts. Twenty (60.6%) of the 34 recipients developed viremia during the first year post‐transplant. Of the recipients who became viremic, six (30%) received rituximab. None of the six who received rituximab‐developed PTLD. We found that recipients who were not monitored on the protocol were more likely to have PTLD and graft loss compared to those who were (p = 0.008). Post‐transplant monitoring of adults who undergo EBV D+/R − kidney transplants for viremia and symptoms associated with EBV infection may prompt intervention which reduces the incidence of PTLD within the first year. Use of rituximab in preventing PTLD among patients with primary EBV infection requires further prospective study to determine its overall safety and efficacy.     

Femoral nerve block with ropivacaine or bupivacaine in day case anterior crucial ligament reconstruction

Background/Objective: Our aim was to evaluate analgesia, motor block and pharmacokinetics of ropivacaine 0.2% and 0.75% in a femoral nerve block (FNB) in day case patients for anterior crucial ligament (ACL)‐reconstruction compared with bupivacaine 0.25% and placebo. Methods: Following ethics committee approval and informed consent, 280 patients were randomly allocated to four groups for single‐shot FNB [30 ml ropivacaine 0.2% (group RO2.0), 0.75% (RO7.5), bupivacaine 0.25% (BU2.5) and NaCl 0.9% (NaCl)]. Analgesia (pain scores, primary outcome) and motor block were assessed at 4 h (dismissal) and up to 24 h. Plasma concentration was determined up to 240 min thereafter. Results: Pain scores at 4 h were significantly higher for NaCl 4 (0–8) (median, range) (vs.) BU2.5 2 (0–8), RO2.0 3 (0–9) and RO7.5 2 (0–8) (NS within the LA groups). Patients of the NaCl group needed analgesics significantly more often (93%) within 4 h after surgery vs. 16% of group RO2.0, 19% of group RO7.5 and 19% of group BU2.5. Motor block was significantly increased with all local anesthetics without a significant difference within the LA groups 3 (0–5) in RO2.0, 3 (0–5) in RO7.5 and 3 (0–4) in BU2.5 vs. 0 (0–3) in group NaCl (median (range); scale from 0=full strength to 5=complete paralysis). Peak plasma concentrations differed significantly: RO7.5: 1.4 ± 0.4 (0.73–2.6) [μg/ml, mean ± SD (range)] after 33 ± 14 (10–40) min, RO2.0: 0.6 ± 0.3 (0.13–1.0) after 22+17 (10–60) and BU2.5: 0.3 ± 0.16 (0.05–0.62) at 31 ± 17 (10–60), respectively. Conclusion: FNB for ACL reconstruction with ropivacaine or bupivacaine provided better post‐operative analgesia than placebo without reaching toxic plasma concentrations. Significant motor block was observed after 4 h in all groups including the lowest concentration of ropivacaine but occurred even with placebo.     

幽门螺杆菌对人胃癌MKN45细胞p38MAPK信号转导通路激活作用的研究

背景与目的: 环氧合酶2(cyelooxygenase-2,COX-2)是花生四烯酸转化为前列腺素(prostaglandins,PGs)代谢中重要的限速酶,幽门螺杆菌(Helicobacterpylori,Hp)感染诱导胃黏膜COX-2的过度表达是胃癌发生的重要环节,但Hp感染胃黏膜细胞COX-2表达的机制尚不清楚.本研究旨在揭示Hp对人胃癌MKN45细胞COX-2表达和p38MAPK信号通路的影响,探讨COX-2表达的可能机制.方法: 采用实时荧光定量PCR(real time-PCR)检测Hp标准株NCTC11637感染对人胃痛MKN45细胞COX-2 mRNA转录的影响,Western blot检测坳COX-2蛋白表达的影响和p38MAPK信号通路的激活及其下游因子ATF-2的表达.结果: Hp感染人胃癌MKN45细胞后,COX-2 mRNA的表达明显上调,Hp感染3、6、9、12 h后COX-2 mRNA的表达量分别为正常值的3倍、7.2倍、5.1倍和4.3倍,各时间组COX-2 mRNA表达均明显高于对照组(P＜0.01);Up与MKN45细胞共培养24 h后,COX-2蛋白的表达亦显著增加(P＜0.01).Hp感染MKN45 20 min后,p38MAPK信号通路被激活,60 min达峰值;p38MAPK下游因子ATF-2的表达也明显增加,2 h达高峰,随着作用时间的延长,表达逐渐下降,24 h仍有表达.结论: Hp感染能诱导人胃癌MKN45细胞COX-2的表达;激活p38MAPK信号通路,增加其下游因子ATF-2的表达,可能是其诱导COX-2表达的机制.     

Controlled ovarian hyperstimulation and intrauterine insemination for treatment of infertility

Empirical therapy for subfertility using assisted reproductive technologies recently has gained popularity; however, the cost-effectiveness of these therapies, compared with an untreated control group, has not been established. Similarly, there has been no comparative cost analysis of the utility of controlled ovarian hyperstimulation and IUI in the management of the same condition. Significant PRs in untreated couples with subfertility mandate the design and execution of controlled trials to ascertain the role of controlled ovarian hyperstimulation and IUI in infertility therapy. Various disorders of subfertility have been treated with controlled ovarian hyperstimulation and IUI. The rationale for this therapy is the increase in gamete density at the site of fertilization, as with GIFT and IVF when used for management of the same problems. The live birth rate per initiated cycle and risk of complications are similar to results recently reported for GIFT and IVF. The utility of controlled ovarian hyperstimulation and IUI still remains controversial. When the relatively low direct and indirect costs of controlled ovarian hyperstimulation and IUI are considered, acknowledging the lack of prospective, controlled studies, this procedure appears to be at least as cost-effective as GIFT and IVF.     

Utility of fluoroimmunoassay in detecting luteinizing hormone surges in spontaneous and human menopausal gonadotropin-stimulated menstrual cycles

Luteinizing hormone (LH) levels measured with radioimmunoassay and time-resolved fluoroimmunoassay (FIA) in 274 serum samples correlated highly, with a linear correlation coefficient of 0.934. Through the analysis of serial samples from 43 women undergoing human menopausal gonadotropin stimulation for in vitro fertilization or gamete intrafallopian transfer and seven patients monitored in spontaneous menstrual cycles for receipt of frozen embryos, we demonstrated the utility of FIA in the detection of the LH surge. This LH assay technique, which involves no radioactive isotopes, should facilitate the monitoring of ovulation induction patients in the office/ambulatory setting.