Protective and therapeutic effects of licorice in rats with acute tubular necrosis.

OBJECTIVES: Various protective and therapeutic effects such as antioxidant, anti-inflammatory, anticancer, antihistaminic, and antibacterial effects have been depicted for licorice. However, its biological effects in the kidney are still not clear. Therefore, we aimed to investigate the efficiency of licorice in rats with gentamicin (GM)-induced acute tubular necrosis. DESIGN AND METHODS: Rats were randomized into the control group (only saline for 12 days), licorice group (licorice for 12 days), GM group (GM for 12 days), GM + licorice group, and licorice-treated GM group (licorice for 12 days after taking GM for 12 days). Blood urea, creatinine, and uric acid levels were measured and histopathological analyses of the kidneys were performed. The oxidative side of oxidant-antioxidant balance was evaluated by detecting lipid peroxidation (LPO) and total peroxide levels, and antioxidative side was determined by measuring total antioxidant capacity (TAC) and reduced glutathione (GSH) levels in plasma and kidney tissues. RESULTS: The oxidant-antioxidant balance seemed to be shifted to the oxidative side in the GM group when compared with the control and GM + licorice groups. In GM group, biochemical profiles showed a remarkable increase in blood uric acid, urea, and creatinine levels, and depletion of renal tissue and plasma TAC and GSH levels. In addition, histopathologic studies revealed severe acute tubular necrosis, congestion, and hyaline casts, verifying GM-induced nephrotoxicity. Licorice was effective in reduction of blood urea, creatinine, and uric acid levels, and also effective in decreasing the tubular necrosis score. Licorice treatment also significantly reduced LPO and total peroxide levels, and increased TAC and GSH levels in both renal tissue and blood. Moreover, these changes in rats subjected to the combined therapy (GM + licorice) were significantly less than those of GM group. CONCLUSIONS: Licorice ameliorates GM-induced nephrotoxicity and oxidative damage by scavenging oxygen free radicals, decreasing LPO, and improving antioxidant defense.

A novel tocolytic agent: effects of letrozole on gestational length and parturition time.

The purpose of this study was to determine whether letrozole, a potent aromatase inhibitor, could prolong gestation and/or delay parturition in rats. Seventy-five rats were divided into five groups of 15 rats each. Group I and group II rats were administered letrozole orally at doses of 0.002 and 0.02 mg/kg/day from days 15 through 21 of pregnancy, respectively. Rats in group IA were administered a concomitant estradiol cyclopentylpropionate (ECP) injection on day 15 and 0.002 mg/kg letrozole in that same manner as for group I. Rats in group IIA were administered concomitant ECP on day 15 and 0.02 mg/kg letrozole in the same manner as for group II. The control group received sterile saline only. Study and control groups were compared with respect to gestational length, parturition time, fetal mortality rate, stillbirth rate, and fetal body weight. Oral administration of letrozole both at daily doses of 0.002 mg/kg/day (group I) and 0.02 mg/kg/day (group II) consistently prolonged gestation and parturition time. The values of stillbirth rate, fetal mortality rate, and fetal body weight of group I were similar to those in the control group; conversely, fetal mortality rate and stillbirth rate of group II were higher than those values in the control group, and fetal body weight of group II was lower than in the control group. It was observed that concomitant injection of ECP effectively reversed the deleterious effects of letrozole on gestational length, parturition time, fetal mortality rate, stillbirth rate, and fetal body weight. The results of this study indicate that the aromatase inhibitor letrozole can prolong gestation and delays parturition in rats. Its deleterious effects on parturition can be reversed by ECP injection.

Scrotal pouch as a urinary reservoir: a surgical revolution or bizarre hypothesis?

INTRODUCTION: Despite of the tissue engineering efforts to substitute the bladder, almost all the urinary diversion techniques still need gastrointestinal segments that have many well documented complications including the life threatening ones such as renal insufficiency and electrolytes imbalances. In this preliminary incomplete animal model, we aimed to introduce the idea of the possibility of scrotal urinary diversion via inguinal canal and speculate its clinical advantages with its low morbidity and surgical technique of human application. TECHNICAL CONSIDERATIONS: After a laporotomy and its left ureter dissection, a male rabbit underwent urinary diversion from kidney to the scrotum via catheter through the inguinal canal. Abdominal and scrotal incision closed with sutures but a potential gap was left at the scrotum for urinary leakage. Urinary leakage was observed from the ipsilateral scrotum postoperatively. THE HYPOTHESIS: Although this study can be regarded as just a hypothesis, we would like to introduce the idea of scrotal pouch as a urinary reservoir. We speculated that scrotal urinary diversion is better and applicable technique with many advantages and low morbidity, mortality and short operation time over the intestinal ones especially in selected patients. Further human studies may improve this novel technique.

A preliminary approach to the separation of Leishmania cell-surface antigens.

The purpose of the current study was to characterize Leishmania cell-surface antigens by two different methods established for the purification of glycoproteins and proteins, and to point out a useful approach to define their size and mass heterogeneity. L. tropica parasites were initially isolated from patients with active cutaneous leishmaniasis and were then cultured in vitro. The parasite-cell layer was solubilised with 6 M guanidinium chloride (GuHCl) and subsequently prepared for the purification procedure. The methods used in this work were gel filtration chromatography and isopycnic density-gradient centrifugation. Because of the presence of a substantial amount of non-specific proteins in the culture medium, these methods were not effective alone in distinguishing these antigens. However, a good idea of their N-glycosylated structures could be obtained by using Periodic acid-Schiffs (PAS) and Con A lectin, and also size and mass heterogeneity. A combination of these methods effected a clear separation of the antigens. Amino acid analysis of the purified antigens was performed to positively identify them as well-known Leishmania cell-surface antigen gene products. The results confirmed the presence of more than one cell-surface antigen on the Leishmania parasite and the combination of gel chromatography and density-gradient centrifugation could be useful for their isolation.

Letrozole-induced polycystic ovaries in the rat: a new model for cystic ovarian disease.

BACKGROUND: Our objective was to develop a new animal model for the study of polycystic ovaries by using the non-steroidal aromatase inhibitor, letrozole. METHODS: Thirty four rats were divided into four groups, including a control group of 10 rats that received vehicle only (1% aqueous solution of carboxmethlycellulose [CMC]) once daily orally (p.o.) and three treatment groups of eight rats each that were administered letrozole at concentrations of 0.1 or 0.5 or 1 mg/kg p.o. dissolved in 1% CMC (2 mL/kg) once daily. The treatment period was 21 days. During this period, vaginal smears were collected daily for estrus cycle determination. On the day subsequent to last letrozole dose administration, rats were killed; uteri and ovaries were then excised and weighed. Serum hormone levels and histologic changes in ovaries were examined. RESULTS: When compared to control group, ovaries from study groups showed high incidence of subcapsular ovarian cyst and capsular thickening together with incomplete luteinization and decreased number of corpora lutea. Letrozole treatment brought about dose-dependent suppression of uterine weight despite having no significant effect on ovarian weight. Although serum estradiol and progesterone levels were reduced in a dose-dependent manner, testosterone levels were elevated as were levels of luteinizing hormone (LH). Serum follicle-stimulating hormone (FSH) levels were markedly increased at higher doses of letrozole (0.5 and 1.0 mg/kg), contrary to low dose of letrozole (0.1 mg/kg) at which slight decrease was observed. CONCLUSIONS: Despite the fact that this is not a fully convincing model for the study of polycystic ovaries or of polycystic ovary syndrome (PCOS) as a whole, this animal model in several ways is similar to the human polycystic ovary syndrome.

A new tension-adjustment technique for sling operation: an animal model.

OBJECTIVE: To investigate the effectiveness of a new tension-adjustment technique for postoperative voiding difficulties encountered after sling operations. METHOD: To test our new method, urethral obstruction was developed in 5 female dogs by modifying the sling operation by exerting more tension on a specially prepared polypropylene strip in which a gap had been developed. After filling the bladder with isotonic solution, detrusor contractions were induced by pelvic nerve stimulations, and urodynamic studies were performed to document the urethral obstruction. In each case Foley catheters were inserted into the bladder and left in place until the time of tension adjustment. Tension adjustment was performed in the 1st, 2nd, 3rd, 4th and 5th weeks postoperatively for dogs 1, 2, 3, 4, and 5, respectively. RESULTS: On the day of tension adjustment, after filling the bladder with isotonic solution and removing the Foley catheter, none of the dogs, except dog 3, was able to produce a free flow of urine either spontaneously or provoked by detrusor contractions. The release of the prolene sutures was readily achieved in all cases except dog 5. In this case, sling takedown was achieved after surgical exploration in which the sling location was confirmed by following the prolene sutures and Hegar's dilator. After identifying the sling, the gap was opened by cutting the prolene sutures, instead of a sling incision. Release of the prolene sutures resulted in a distinct drop in the urethra with decreased resistance of Hegar's dilator. The improvement in voiding was confirmed by postoperative urodynamic studies and was immediate in all cases. CONCLUSION: Our new technique for postoperative voiding difficulties encountered after sling operation is simple, effective and avoids re-operation in the early postoperative period.