Kallikrein gene 'knock-down' by small interfering RNA transfection induces a profibrotic phenotype in rat mesangial cells

BACKGROUND: Emerging evidence suggests that kallikrein exerts renoprotective effects independent of its haemodynamic actions. The aim of the current investigation was to delineate the role of kallikrein in the regulation of fibrosis, by 'knocking down' its expression using specific small interfering RNAs (siRNA). METHODS: Rat mesangial cells were treated with 12, 60, 120 nmol/l kallikrein-specific siRNAs. The consequent cellular genotypes and phenotypes were analysed. RESULTS: Western blotting demonstrated that mesangial cells produced a kallikrein protein, which was of a different molecular weight to urinary kallikrein from rats of the same species. Treatment of cells with siRNA resulted in a dose-dependent decrease in kallikrein mRNA levels, which impacted on other components of the kallikrein-kinin system, dose-dependently reducing bradykinin B2 receptor mRNA expression. Kallikrein suppression resulted in significant increases in fibronectin and transforming growth factor-beta protein levels in culture supernatants over control levels. Gelatin zymography demonstrated a siRNA dose-dependent decrease in active MMP-2 enzyme levels. Bradykinin, an effector molecule of the kallikrein system, is known to stimulate tissue plasminogen activator production. Paradoxically, however, tissue plasminogen activator protein levels were augmented with increasing kallikrein mRNA silencing. This was accompanied by a dose-dependent decrease in low-density lipoprotein receptor-related protein mRNA levels, indicating that increased tissue plasminogen activator levels were due to an attenuation of receptor-mediated protease clearance. CONCLUSION: These data lend strong support to the hypothesis that kallikrein exerts antifibrotic, renoprotective effects that are independent of its classical haemodynamic actions.     

Research committee

The JCAH move to evaluate clinical outcomes as part of its ongoing accreditation process has significant implications for infection control, APIC, and research. Through a concerted, progressive plan to address this issue, APIC can be a pathfinder in helping to prepare its members for this change. A proactive approach to both continued input into the process and the initiation of research to establish the groundwork are clearly indicated.     

Minimally invasive mitral valve surgery: from Port Access to fully robotic-assisted surgery

Currently, there is a growing interest in minimally invasive cardiac surgery, and despite early criticisms, it has become the preferred method of mitral valve repair and replacement in many institutions worldwide with excellent results. The interest in performing cardiac valve operations through minimal incisions was stimulated by Port Access technology and has evolved to include robotically assisted video-enhanced valve surgery. Robotic assistance has led to shorter operating times and represents an ideal tool to prepare for fully robotic-assisted cardiac procedures. This report will highlight minimally invasive mitral valve surgery with its evolution from Port Access techniques to fully robotic-assisted surgery. The nuances, strengths, and shortcomings, as well as the potential to enhance the valvular procedure, the promise to reduce hospital stay, earlier return to normal activity, less pain, better cosmesis, and the rethinking of surgical dogma that wide surgical exposure is essential for such complex intracardiac surgery are discussed.     

Pancreaticoduodenectomy after placement of endobiliary metal stents

Contemporary treatment programs for patients with potentially resectable pancreatic cancer often involve preoperative therapy. When the duration of preoperative therapy exceeds 2 months, the risk of plastic endobiliary stent occlusion increases. Metal stents have much better patency but may complicate subsequent pancreaticoduodenectomy (PD). We evaluated rates of perioperative morbidity, mortality, and stent complications in 272 consecutive patients who underwent PD at our institution from May 2001 to November 2004. Of these 272 patients, 29 (11%) underwent PD after placement of a metal stent, 141 underwent PD after placement of a plastic stent, 10 had PD after biliary bypass without stenting, and 92 had PD without any form of biliary decompression. No differences were found between the Metal Stent group and all other patients in median operative time, intraoperative blood loss, or length of hospital stay. No perioperative deaths occurred in the Metal Stent group versus 3 (1.2%) deaths in the other 243 patients. The incidence of major perioperative complications was similar between the two groups, including the rates of pancreatic fistula, intra-abdominal abscess, and wound infection. Furthermore, there were no differences in the perioperative morbidity or mortality rates between patients who underwent preoperative biliary decompression with a stent of any kind (metal or plastic) and those patients who underwent no biliary decompression at all. Metal stent-related complications occurred in 2 (7%) of 29 patients during a median preoperative interval of 4.1 months; in contrast, 75 (45%) of the 166 patients who had had plastic stents experienced complications, including 98 stent occlusions, during a median preoperative interval of 3.9 months (P < 0.001). We conclude that the use of expandable metal stents does not increase PD-associated perioperative morbidity or mortality, and as such an expandable metal stent is our preferred method of biliary decompression in patients with symptomatic malignant distal bile duct obstruction in whom surgery is not anticipated, or in whom there is a significant delay in the time to surgery. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation). Supported by the Lockton Fund for Pancreatic Cancer Research, The University of Texas M. D. Anderson Cancer Center, Houston, Texas.     

Postoperative outcome of caesarean sections and other major emergency obstetric surgery by clinical officers and medical officers in Malawi

Background  

Clinical officers perform much of major emergency surgery in Malawi, in the absence of medical officers. The aim of this study was to validate the advantages and disadvantages of delegation of major obstetric surgery to non-doctors.