Ischemic Preconditioning Decreases Laparoscopy Induced Oxidative Stress in the Liver

Experimental studies indicate that oxidative stress during and after laparoscopic surgery may cause liver ischemia-reperfusion injury. The aim of the study was to assess the effect of ischemic preconditioning against liver damage during pneumoperitoneum on oxidative stress. Twenty one New Zealand rabbits were divided into three groups of seven animals. Control group (C) rabbits received anesthesia for 60 min alone; 15 mm Hg intra-abdominal pressure with CO2 for 60 min was used in the pneumoperitoneum group animals (PNP); and 15-min insufflation and 10-min desuflation followed by 60-min pneumoperitoneum were used in the ischemic preconditioning group animals (IP). Venous blood samples were obtained at different time points to measure lipid hydroperoxide, glutathione reductase and total antioxidant status as indicators of increased oxidative stress. Aspartate transaminase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels were evaluated as indicators of hepatocellular injury. The Kruskal-Wallis and Mann-Whitney U tests were used on statistical analysis. Elevated intra-abdominal pressure was found to produce significant increase in lipid hydroperoxide at the end of pneumoperitoneum and 30 min after desuflation in comparison with pre-insufflation period, and with both C and IP groups at the same time points. Total antioxidant status level decreased significantly in the PNP group at 24 h of desuflation. At 24h of desuflation, the AST, ALT and LDH levels were significantly increased in the PNP group in comparison with the levels measured before induction of anesthesia, and with the C and IP groups. Study results demonstrated that ischemic preconditioning prevented hepatocyte injury and oxidative stress during CO2 pneumoperitoneum

A thematic analysis of factors influencing recruitment to maternal and perinatal trials

Background: Recruitment of eligible participants remains one of the biggest challenges to successful completion of randomised controlled trials (RCTs). Only one third of trials recruit on time, often requiring a lengthy extension to the recruitment period. We identified factors influencing recruitment success and potentially effective recruitment strategies. Methods: We searched MEDLINE and EMBASE from 1966 to December Week 2, 2006, the Cochrane Library Methodology Register in December 2006, and hand searched reference lists for studies of any design which focused on recruitment to maternal/perinatal trials, or if no studies of maternal or perinatal research could be identified, other areas of healthcare. Studies of nurses' and midwives' attitudes to research were included as none specifically about trials were located. We synthesised the data narratively, using a basic thematic analysis, with themes derived from the literature and after discussion between the authors. Results: Around half of the included papers (29/53) were specific to maternal and perinatal healthcare. Only one study was identified which focused on factors for maternal and perinatal clinicians and only seven studies considered recruitment strategies specific to perinatal research. Themes included: participant assessment of risk; recruitment process; participant understanding of research; patient characteristics; clinician attitudes to research and trials; protocol issues; and institutional or organisational issues. While no reliable evidence base for strategies to enhance recruitment was identified in any of the review studies, four maternal/perinatal primary studies suggest that specialised recruitment staff, mass mailings, physician referrals and strategies targeting minority women may increase recruitment. However these findings may only be applicable to the particular trials and settings studied. Conclusion: Although factors reported by both participants and clinicians which influence recruitment were quite consistent across the included studies, studies comparing different recruitment strategies were largely missing. Trials of different recruitment strategies could be embedded in large multicentre RCTs, with strategies tailored to the factors specific to the trial and institution.Rebecca L Tooher, Philippa F Middleton and Caroline A Crowthe

Acoustic techniques for localizing holdup

Material that does not come out of a process as product or waste is called holdup. When this is fissile material, its location and quantity must be determined to improve safeguards and security as well as safety at the facility. The most common method for detecting and measuring holdup is with radiation based techniques. When using them, one must consider equipment geometry, geometry of holdup, and effects of background radiation when converting the radiation measurement into a fissile material quantity. We are developing complementary techniques that use tiny acoustic transducers, which are unaffected by background radiation, to improve holdup measurements by aiding in determining the above conversion factors for holdup measurements. Thus far, we have applied three techniques, Acoustic Interferometry, Pulse Echo, and bending Wave Propagation, of which the latter appears most effective. This paper will describe each of these techniques and show how they may ultimately reduce costs and personnel radiation exposure while increasing confidence I and accuracy of holdup measurements

Ovariectomy of a brown bear (Ursus arctos): a case report

ABSTRACT: Reproductive control is regularly implemented in bear facilities to prevent crowding of enclosures and surplus animals. Ovariectomy may represent an efficient method of sterilizing bears yet has not been reported in the literature. A 73 kg female brown bear, age two years and three months, was anesthetized for ovariectomy with tiletamin and zolazepam (Zoletil ® , Virbac S.A., Carros Cedex, France) and medetomidin hydrochloride (Domitor ® , Pfizer Animal Health, New York, USA). A 25 cm midline incision that extended from the umbilicus to the pubic brim was made. The suspensory ligament was stretched and blunt dissected so that ovaries in bursa were exposed on the surgical field. A &quot

Densitometry of calus mineralization in a critical size defect of a rabbit radius

This study aims to investigate the use of a photodensitometry to analyze plain radiographic images and correlate them with the rate of new bone formation in a critical size defect of a rabbit radius filled with an autologous omental graft. The computer program MCID Evaluation 7.0. was used for photodensitometric processing of X-ray images taken at 2, 4, 6 and 8 weeks after surgery. The study was conducted on 20 adult New Zealand white rabbits under general anaesthesia, critical-sized osseous defect was created in the right radius and in treated group filled with autogenous omental graft. Optical densitometry of radiographs revealed statistically significant differences between the experimental and control sites. The study showed that autogenous omental grafts promoted healing of the critical-sized defect of the rabbit radius. Key words: bone, densitometry, omentum, radiogra

Characterisation of subchondral bone repair following transplantation of bioreactor-manufactured autologous osteochondral graft in a sheep model

To date, no single approach to the treatment of osteochondral defects has resulted in satisfactory long-term outcomes, especially in a young and active human population. Emerging innovative tissue engineering strategies, including the use of composite scaffolds, novel cell sources and bioreactors, have shown promising results. However, these techniques need to be validated in translational animal models before they can be implemented in clinical practice. The aim of the present study was to analyse morphological and microarchitectural parameters during subchondral bone repair following transplantation of bioreactor-manufactured autologous osteochondral grafts in a sheep model. Animals were divided into 4 treatment groups: nasal chondrocyte (NC) autologous osteochondral grafts, articular chondrocyte (AC) autologous osteochondral grafts, cell-free scaffolds (CFS) and empty defects (EDs). After 6 weeks, 3 months and 12 months, bone remodelling was assessed by histology and micro-computed tomography (µCT). Although gradual remodelling and subchondral bone repair were seen in all groups across the time points, the best results were observed in the NC group. This was evidenced by the extent of new tissue formation and its best integration into the surrounding tissue in the NC group at all time points. This also suggested that nasal septum chondrocyte-seeded grafts adapted well to the biomechanical conditions of the loaded joint surface