The effects of montelukast on random pattern skin flap survival: An experimental study in rats

Background: A variety of methods to improve skin flap survival, including the use of pharmacologic agents, have been intensively investigated. Decreasing neutrophil-mediated inflammation and tissue injury has been reported to be effective in improving flap survival. Montelukast is a selective reversible cysteinyl leukotriene receptor-1 antagonist that has been found to have protective effects against renal ischemia reperfusion injury and burn-induced oxidative injury of the skin in rats. However, its effects on skin flap survival have not been previously reported.Objective: The aim of this study was to investigate the effects of montelukast on neutrophil-mediated random pattern skin flap survival.Methods: Male Sprague-Dawley rats weighing 230 to 250 g were randomly divided into 2 groups—the montelukast-treated group and the control group. Caudally based rectangular random pattern skin flaps 3 × 9 cm were elevated on the backs of the rats. The flaps were sutured into their original places. In the montelukast group, 1 mL of solution containing 10 mg/kg montelukast was administered intraperitoneally (IP) 30 minutes before surgery and then daily for 6 days. In the control group, 1 mL of saline was administered IP 30 minutes before surgery and then daily for 6 days. To observe the effects of montelukast, myeloperoxidase (MPO) activity, an index of tissue neutrophil infiltration, was measured from extracted skin tissue 12 hours after flap elevation. Flap viability was evaluated 7 days after surgery by measuring necrotic flap area and total flap area.Results: Sixteen rats (mean [SD] weight, 240.6 [6.6] g) were equally divided between the 2 groups. All rats survived throughout the study period. Mean (SD) MPO activity in flap tissue was significantly lower in the montelukast group than in the control group (14.57 [2.33] vs 21.28 [4.86] U/g protein; P = 0.005). The percentage of necrotic flap area was significantly lower in the montelukast group than in the control group (17.17 [7.95] vs 37.51 [10.72]; P = 0.001).Conclusion: This small, experimental, in vivo animal study found that montelukast was associated with both lower MPO activity and a lower percentage of necrotic random pattern skin flap area. Future studies are needed to clarify these findings.     

Measuring local RF heating in MRI: Simulating perfusion in a perfusionless phantom

PURPOSE: To overcome conflicting methods of local RF heating measurements by proposing a simple technique for predicting in vivo temperature rise by using a gel phantom experiment. MATERIALS AND METHODS: In vivo temperature measurements are difficult to conduct reproducibly; fluid phantoms introduce convection, and gel phantom lacks perfusion. In the proposed method the local temperature rise is measured in a gel phantom at a timepoint that the phantom temperature would be equal to the perfused body steady-state temperature value. The idea comes from the fact that the steady-state temperature rise in a perfused body is smaller than the steady-state temperature increase in a perfusionless phantom. Therefore, when measuring the temperature on a phantom there will be the timepoint that corresponds to the perfusion time constant of the body part. RESULTS: The proposed method was tested with several phantom and in vivo experiments. Instead, an overall average of 30.8% error can be given as the amount of underestimation with the proposed method. This error is within the variability of in vivo experiments (45%). CONCLUSION: With the aid of this reliable temperature rise prediction the amount of power delivered by the scanner can be controlled, enabling safe MRI examinations of patients with implants.     

Acute renal failure in a patient with severe hemolysis

Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal disorder of bone marrow. It is characterized by blood cells lacking membrane proteins that are normally attached by the glycosylphosphatidylinositol (GPI) anchor. The cellular defect arises in a hematopoetic stem cell and is due to somatic mutation of the Phosphatidylinositol-glycan protein-A gene (PIG-A gene), encoding a protein needed for the biosynthesis of the anchor GPI. Paroxysmal nocturnal hemoglobinuria is presented by intravascular hemolysis, cytopenias, frequent infections, bone marrow hypoplasia, and a high incidence of life threatening venous thrombosis. Kidney involvement is usually benign and secondary to chronic tubular deposition of hemosiderin. Acute renal failure may occur in association with a hemolytic crisis. Here we report a case of 40-year-old woman with hematuria, pancytopenia, and acute renal failure due to PNH.     

Amazia with Midface Anomaly: Case Report

Amazia, the absence of the mammary gland, is a very rare congenital anomaly of the breasts. Bilateral absence of the breasts may occur as an isolated anomaly or may be associated with a syndrome or a cluster of other anomalies. Although the literature examining pediatric breast abnormalities is replete with case reports and series, bilateral amazia together with skeletal anomalies has not yet been described. An unusual case of amazia associated with face, limb, and vertebrae anomalies is presented. Presented as a poster presentation at the winter symposium of the Turkish Society of Plastic, Reconstructive, and Aesthetic Surgery, Ilgaz Mountain Resort Hotel, Kastamonu, Turkey in 2005, and at the 9th congress of Aesthetic and Plastic Surgery, Swiss Hotel, Istanbul, Turkey in 2005     

Effects of Pyrrolidine Dithiocarbamate on Healing of Colonic Anastomoses in the Cecal Ligation and Puncture Model of Intraperitoneal Sepsis in Rats

Introduction Pyrrolidine dithiocarbamate (PDTC) is a low-molecular thiol antioxidant and potent inhibitor of nuclear factor-κB (NF-κB) activation. In recent animal studies, the delaying effect of intraperitoneal sepsis on healing of colonic anastomoses has been demonstrated. In this study, we aimed to investigate the effects of PDTC on healing of colonic anastomoses in the presence of intraperitoneal sepsis induced by a rodent model of cecal ligation and puncture (CLP). Methods Anastomosis of the left colon was performed on the day following CLP in 30 rats that were divided into three groups: sham-operated control (laparotomy and cecal mobilization, group I, n =10), cecal ligation and puncture (CLP) (group II, n = 10), PDTC-treated group (100 mg/kg IV before construction of the colonic anastomosis) (group III, n = 10). On postoperative day 6, all animals were sacrificed, and anastomotic bursting pressures were measured in vivo. Tissue samples were obtained for further investigation of colonic anastomotic hydroxyproline (HP) contents, perianastomotic myeloperoxidase (MPO) activity, and malondialdehyde (MDA) and glutathione (GSH) levels. Results There was a statistically significant increase in the activity of MPO and MDA levels in the CLP group (group II) along with a decrease in GSH levels, colonic anastomotic HP contents, and bursting pressure values when compared to controls (group I). However, PDTC treatment led to a statistically significant increase in the tissue HP contents, GSH levels, and colonic anastomotic bursting pressure values, along with a decrease in MPO activity and MDA levels in group III (p < 0.05). Conclusions This study showed that PDTC treatment significantly prevented the delaying effect of CLP-induced intraperitoneal sepsis on anastomotic healing in the colon. Further clinical studies are needed to clarify whether PDTC may be a useful therapeutic agent to increase the safety of the anastomosis during particular operations where sepsis-induced injury occurs.