May glutathione S-transferase M1 positive genotype afford protection against primary open-angle glaucoma?

Purpose To find out whether the polymorphism at GSTM1, GSTT1 and GSTP1 loci is associated with increased susceptibility to glaucoma.Methods We genotyped 153 primary open angle patients and 159 healthy controls. Genomic DNA from peripheral blood was examined using polymerase chain reaction and defined for the genetic polymorphisms of glutathione S-transferase.Results The frequency of the GSTM1 null genotype individuals among the glaucoma patients was significanlty higher than in controls (54.9 vs 40.9%) with odds ratio of 1.64 (95% CI: 1.10–2.59). The frequency of the GSTT1 and GSTP1 in both groups were not statistically different.Conclusion The present study suggests that the GSTM1 null genotype may be a genetic risk factor for development of primary open angle glaucoma. Further associations studies in other polymorphic genes for xenobiotic–metabolizing enzymes are needed to elucidate the environmental-genetic interaction in the underlying cause of primary open angle glaucoma.     

Effect of changes in renal perfusion pressure on the suppression of proximal tubular sodium reabsorption due to saline loading

Rapid intravenous infusion of saline is known to suppress reabsorption of sodium and water in the proximal tubule. It has previously been shown that this suppression is accompanied by two changes which in combination might account for the over-all decrease in reabsorption: a reduction in the intrinsic reabsorptive capacity of the tubular epithelium (C/pir(2)) and a reduction in the ratio between tubular volume and GFR (pir(2)d/V(o)). The present micropuncture experiments were carried out in order to study the possible role of altered peritubular physical forces (hydrostatic and colloid oncotic pressure) in mediating these two changes. Proximal tubular reabsorptive capacity, transit time, fractional reabsorption of sodium and water, pir(2)d/V(o), and intratubular hydrostatic pressure were measured in saline-loaded rats during acute changes in renal perfusion pressure induced by intermittent constriction of the abdominal aorta.We found that when renal perfusion pressure was lowered to 70-90 mm Hg, the usual effects of saline loading on C/pir(2), pir(2)d/V(o), and fractional reabsorption in the proximal tubule were greatly minimized. When the aortic clamp was released and renal perfusion pressure allowed to rise, C/pir(2), pir(2)d/V(o), and fractional reabsorption fell markedly to levels characteristically seen in saline diuresis. Reclamping of the aorta reversed all of these changes.In order to determine whether the changes in C/pir(2) accompanying changes in renal perfusion pressure were mediated by a circulating natriuretic hormone, we assayed in hydopenic rats the dialysate of plasma collected from saline-loaded rats during and after release of aortic constriction by the split oil drop method. No significant difference in reabsorptive half-time (t(1/2)) was found between the two dialysates, and t(1/2) with both dialysates was approximately the same as was found when isotonic saline was injected in the tubules of hydropenic control animals. These observations suggest that the large changes in C/pir(2) which occurred with changes in renal perfusion pressure in saline-loaded rats were not mediated by a circulating hormone. We suggest that the reduction in C/pir(2), pir(2)d/V(o), and fractional reabsorption which occurs in the proximal tubule during a saline diuresis is related to the rise in hydrostatic pressure within the kidney.     

Use of continuous horizontal mattress suture techniques in microsurgery: an experimental study in rats

PURPOSE: The purpose of this study was to determine whether the continuous horizontal mattress suture technique can replace the continuous simple suture technique and to compare the results with other microvascular suture procedures. METHODS: Sixty-four femoral arteries of 32 Sprague-Dawley rats were used in this study. The animals were divided equally into 4 groups with 16 anastomoses in each group. The arteries (0.8-1.0 mm diameter) were anastomosed by using the continuous horizontal mattress suture technique in group I, interrupted horizontal mattress suture technique in group II, simple interrupted suture technique in group III, and simple continuous suture technique in group IV. At the end of the anastomosis time, leakage, and patency were assessed and graded in all groups. On the 14th day after surgery the rats were killed and 5 patent specimens from each group were examined under light microscopy for histology. One specimen from each group was prepared for scanning of the endothelial surface under electron scanning microscopy. RESULTS: Group I anastomoses were performed the most quickly. Groups I and III anastomoses had 100% patency rates. Under light microscopy the edge eversion was apparent consistently and under electron microscopy all endothelial surfaces were intact and no suture material was seen in groups I and II. In group III some suture material was covered by endothelial cells and lumen surfaces were torn; endothelization also was rough compared with groups I and II. In group IV suture material was seen in the lumen because of a loose suture knot. The endothelium also was not regular. CONCLUSIONS: The horizontal mattress suturing technique is the only technique in which the suture material never contacts the lumen. Continuous horizontal mattress suture technique is superior to the other microvascular procedures and is the safest and fastest procedure for microvascular anastomosis in rats.     

Supercharged reverse-flow sural flap: a new modification increasing the reliability of the flap

The management of soft-tissue defects in the lower third of the leg and foot presents a considerable problem because of composite tissue defects, inadequate and tight local tissue for reconstruction, and poor circulation. Although the reverse sural flap is frequently preferred and is fairly reliable, some complications arising from the circulation may be encountered in large flaps or in diabetic patients. In the present study, we developed a new modification by supercharging the sural flap to reduce venous congestion and edema and to increase the reliability of the flap. We treated 3 patients (2 men and 1 woman) by utilizing a supercharged reverse sural flap. All flaps survived and healed uneventfully. We also suggest a new and more distinctive classification for supercharging and turbocharging, which defines the vessel type to be anastomosed and the relationship of the vessel to be anastomosed with the main vessel to the flap.     

Preoperative multimodal administration of morphine in arthroscopic surgery

Introduction The aim of the study was to demonstrate the possible effects of preoperative intra-articular, intravenous, or intrathecal administration of morphine on postoperative pain management.Materials and methods Sixty patients undergoing arthroscopic menisectomy were included. Spinal anesthesia was performed in the lateral decubitus position with 3 ml of 0.5% hyperbaric bupivacaine, and the patients were randomized into 4 groups. The IVM (intravenous, iv, morphine) group received 3 mg of iv morphine after completion of spinal anesthesia, the ITM (intrathecal morphine) group received 0.3 mg of morphine together with bupivacaine during spinal anesthesia, the IAM (intra-articular morphine) group received 3 mg intra-articular morphine diluted in 10 ml of saline after spinal anesthesia had been induced but 15 min before surgery, while the C (control) group did not receive any drugs in addition to spinal anesthesia. The sensory block level was determined 15 min after spinal anesthesia. Pain at rest (by visual analogue scale, VAS) and pain at 30° of flexion (by verbal rating scale, VRS) were evaluated during each of the first 2 h of the postoperative period and once every 4 h thereafter until 24 h. In each group; the number of patients in need of analgesics, the timing of the first analgesic intake (duration of analgesia), and the cumulative dose of analgesics were recorded.Results The mean duration of analgesia in the IAM group was significantly longer and the mean analgesic intake was significantly lower when compared with the other groups (p<0.05). The mean VAS value of the ITM group at the 4th postoperative hour was significantly lower than that of the other groups. Mean VAS values at 8 and 12 h and mean VRS values at 4 and 8 h were significantly lower in the ITM and IAM groups (p<0.05). The ITM group had the highest rates of nausea, vomiting, pruritus, and headache (p<0.05).Conclusion It was concluded that the preoperative administration of morphine, either intrathecally or intra-articularly, provides postoperative pain relief. Of these two, the intra-articular route seems to be superior in terms of fewer side-effects (nausea, vomiting, and pruritus), longer duration of analgesia, and reduction of total need for analgesics.     

What Is The Role of Mechanical Bowel Preparation in Patients with Pilonidal Sinus Undergoing Surgery? Prospective, Randomized, Surgeon-blinded Trial

The aim of this study was to determine the effect of a mechanical bowel preparation on postoperative surgical wound infections in patients treated with identical antimicrobial prophylaxis undergoing wide excision and primary closure for chronic pilonidal sinus disease. Patients more than 18 years old were included in the study. All patients had intravenous antimicrobial prophylaxis at the time of anesthesia induction. In a prospective, randomized setting, patients were allocated to either the bowel preparation group or the no-bowel-preparation group. Mechanical bowel preparation was performed using an oral sodium phosphate solution. On the morning of the procedure a rectal enema was performed with the phosphate solution. The primary outcome measure was the rate of wound infection, but all postoperative complications and recurrences were recorded. All patients were actively observed for 1 year after discharge. The overall infection rate for the entire study population was 12.8% (13/101) including 14.3% (7/49) of those who had had the bowel preparation and 11.5% (6/52) of those with no bowel preparation. There was no statistically significant difference between groups (P = 0.680). The mean rate of recurrence for all 101 patients was 4.9% (5/101) at 19.2 months (range 12–32 months) of follow-up. The recurrence rate was 6.1% (3/49) in the bowel preparation group and 3.8% (2/52) in the no-bowel-preparation group (P = 1.000). Although the number of patients is small in this study, our results showed that the mechanical bowel preparation does not cause a decrease in the rate of surgical wound infections after excision and primary closure in patients with chronic pilonidal sinus disease.