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

Acoustic resonance spectroscopy intrinsic seals

We have begun to quantify the ability of acoustic resonance spectroscopy (ARS) to detect the removal and replacement of the lid of a simulated special nuclear materials drum. Conceptually, the acoustic spectrum of a container establishcs a baseline fingerprint, which we refer to as an intrinsic seal, for the container. Simply removing and replacing the lid changes some of the resonant frequencies because it is impossible to exactly duplicate all of the stress patterns between the lid and container. Preliminary qualitative results suggested that the ARS intrinsic seal could discriminate between cases where a lid has or has not been removed. The present work is directed at quantifying the utility of the ARS intrinsic seal technique, including the technique`s sensitivity to ``nuisance`` effects, such as temperature swings, movement of the container, and placement of the transducers. These early quantitative tests support the potential of the ARS intrinsic seal application, but also reveal a possible sensitivity to nuisance effects that could limit environments or conditions under which the technique is effective

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

Comparison of the Effects of Low Intra-Abdominal Pressure and Pentoxifylline on Oxidative Stress during CO<sub>2</sub> Pneumoperitoneum in Rabbits

&lt;i&gt;Background:&lt;/i&gt; The aim of this study was to investigate the effect of low-pressure pneumoperitoneum and pentoxifylline, a methylxanthine derivative, in the prevention of injury caused by free oxygen radicals generated during CO&lt;sub&gt;2 &lt;/sub&gt;pneumoperitoneum. &lt;i&gt;Methods:&lt;/i&gt; Twenty-eight rabbits were allocated randomly to 4 groups. Control group rabbits (group 1) were subjected to anesthesia for 60 min; group 2 and 3 animals were subjected to a CO&lt;sub&gt;2&lt;/sub&gt; pneumoperitoneum (15 or 7 mm Hg); and group 4 rabbits received 50 mg/kg pentoxifylline, followed by a 15-mm-Hg pneumoperitoneum. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), lipid hydroperoxide, glutathione reductase and total antioxidant status were measured. &lt;i&gt;Results:&lt;/i&gt; Compared with group 1, a significant increase in lipid hydroperoxide levels at the end of the pneumoperitoneum and 30 min after deflation and a significant decrease in total antioxidant status 24 h after deflation were recorded in group 2. In addition, a significant increase was observed in ALT, AST and LDH levels. These changes were attenuated by low-pressure pneumoperitoneum, whereas pentoxifylline pretreatment appeared to attenuate only transaminase levels. &lt;i&gt;Conclusion:&lt;/i&gt; Low-pressure pneumoperitoneum could attenuate ischemia/reperfusion injury induced by CO&lt;sub&gt;2 &lt;/sub&gt;pneumoperitoneum in a rabbit model whereas pentoxifylline pretreatment appeared to attenuate only transaminase levels. Pentoxifylline did not prevent the development of oxidative stress.</jats:p