Comparison of human amniotic membrane and hyaluronate/carboxymethylcellulose membrane for prevention of adhesion formation in rats

Objectives To investigate the effectiveness of human amniotic membrane (HAM) in the prevention of postoperative adhesion formation and to compare it with the efficacy of hyaluronate/carboxymethylcellulose (HA/CMC) membrane in a rat model. Methods Following pilot studies and computer-generated randomization, 23 female Wistar albino rats were operated on in the full study. One of the uterine horns with standard lesions was treated with either HAM (n = 13) or HA/CMC (n = 10) and the other uterine horn served as the control. Second look laparotomies were performed 2 weeks after the operations. Main outcome measures were extent, severity, degree, total adhesion scores and histopathologic characteristics of adhesions. Results Uterine horns treated with HAM had significantly lower total adhesion scores than the controls (5.15 ± 2.67 vs. 7.92 ± 1.50, P < 0.05). Total adhesion scores of uterine horns treated with HA/CMC membrane were significantly lower than those of the controls (4.30 ± 1.95 vs. 7.50 ± 1.84, P < 0.01). There were no significant differences between the HAM and HA/CMC groups regarding any adhesion scores. Conclusions HAM and HA/CMC membrane are both effective for prevention of adhesion formation in a rat uterine horn model; however, one does not seem to be more effective than the other.     

Reduction of CO2-pneumoperitoneum-induced metabolic hypoxaemia by the addition of small amounts of O2 to the CO2 in a rabbit ventilated model. A preliminary study

Dear Sir, We read with great interest the recent paper (Mynbaev et al.,2002) on the reduction of CO₂-pneumoperitoneum-induced metabolichypoxaemia by the addition of small amounts of O₂ to the CO₂in a rabbit ventilated model. In the     

Uterine activity during sleep

REM-related increases in uterine activity were found in 10 healthy young adult volunteer subjects. Contraction baseline pressures were elevated compared with NREM sleep, stage 2 sleep, stages 3 and 4 slow wave sleep (SWS), and stage 0. Contraction amplitudes during REM sleep were greater than those during SWS and stage 0, while contraction rates differed only between REM sleep and SWS. The results strongly indicated a cycle of genital activity in women that parallels the penile erection cycle in men. The implications of this finding and suggestions for future research are discussed.     

Test-retest reproducibility of quantitative CBF measurements using FAIR perfusion MRI and acetazolamide challenge.

The reproducibility of quantitative cerebral blood flow (CBF) measurements using MRI with arterial spin labeling and acetazolamide challenge was assessed in 12 normal subjects, each undergoing the identical experimental procedure on two separate days. CBF was measured on a 1.5T scanner using a flow-sensitive alternating inversion recovery (FAIR) pulse sequence, performed both at baseline and 12 min after intravenous administration of acetazolamide. T(1) was measured in conjunction with the FAIR scan in order to calculate quantitative CBF. The CBF maps were segmented to separate gray matter (GM) from white matter (WM) for region-of-interest (ROI) analyses. Post- acetazolamide CBF values (ml/100 g/min, mean +/- SD) of 87.5 +/- 12.5 (GM) and 46.1 +/- 10.8 (WM) represented percent increases of 37.7% +/- 24.4% (GM) and 40.1% +/- 24.4% (WM). Day-to-day differences in baseline CBF were -1.7 +/- 6.9 (GM) and -1.4 +/- 4.7 (WM) or, relative to the mean CBF over both days for each subject, -2.5% +/- 11.7% (GM) and -3.8% +/- 13.6% (WM) Day- to-day differences in absolute post-ACZ CBF increase were -2.5 +/- 6.8 (GM) and 2.7 +/- 9.4 (WM) or, relative to the mean CBF increase over both days for each subject, -4.7% +/- 13.3% (GM) and 9.1% +/- 26.2% (WM). Thus, FAIR- based CBF measurements show satisfactory reproducibility from day to day, but with sufficient variation to warrant caution in interpreting longitudinal data. The hemispheric asymmetry of baseline CBF and post-acetazolamide CBF increases varied within a narrower range and should be sensitive to small changes related to disease or treatment.     

Effects of pyrolytic carbon on postoperative adhesion formation in rats

Background  Peritoneal adhesion is a consequence of wound healing that sometimes causes severe postoperative complications. Despite all the preventive measures and agents, adhesions have still not been eliminated completely. The aim of this study was to evaluate the effects of pyrolytic carbon on the development of postoperative peritoneal and uterine tube adhesions. Material and method  Twenty female Wistar–Albino type rats were used in this study. The rats were divided into two groups: treatment and control groups. After ketamine anaesthesia (50 mg/kg IM), a lower midline abdominal incision was performed and a standard uterine lesion was created by electrocauterization. In the study group, pyrolytic carbon was applied to the surface of the uterus and no additional procedure was applied in the control group. After 2 weeks, all of the rats were killed and uterine adhesions were staged according to the Leach scoring system. Results  In the control group, the total adhesion score was 8.8 ± 0.42. In the study group, the total adhesion score was 3.3 ± 1.49, significantly lower than that in the control group (P < 0.001). Conclusion  Pyrolytic carbon significantly reduces the prevalence of peritoneal and uterine tube adhesion formation in rats. However, further more detailed investigations are needed before this material is used in clinical practice.