[Effects of delivery and oophorectomy on urethral collagen: an experimental study]. / Efectos del parto y ooforectomía sobre el colágeno uretral: estudio experimental.

OBJECTIVE: Stereological evaluation of the concentration of type I and III collagen fibers in the urethral tissue of rats subjected to simulated labor and oophorectomy. To compare the concentrations of collagen between oophorectomized and non-oophorectomized rats. MATERIAL AND METHOD: Sixty adult Wistar rats were divided into six groups. A group made up of virgin rats was used as control group and another group was made up of oophorectomized rats. Two groups underwent vaginal distention for 30 and 120 minutes, respectively. The two other groups were subjected to the same distension periods, followed by oophorectomy. Sixty days later, euthanasia and removal of urethral tissue was carried out for stereological analysis of type I and III collagen after staining with hematoxylin and eosin and picrosirius red. RESULTS: A decrease in estrogen levels was observed in the oophorectomized rats. There was a reduction of type III collagen in the oophorectomized control group compared to the control group when analyzed independently. No significant differences were observed among the other groups. Type I collagen decreased in all groups compared to the control group. However, in the prolonged vaginal distension and oophorectomy group, these fibers increased. CONCLUSION: In normal rats, simulation of labor does not alter the collagen III levels. In hypoestrogenic rats, the concentration of collagen type I and III decreased, except in those undergoing prolonged labor simulation in which collagen I increased.

Relationship between ischemia/reperfusion injury and the stimulus of fibrogenesis in an experimental model: comparison among different preservation solutions.

BACKGROUND AND AIMS: Orthotopic liver transplantation (OLT) has been the standard treatment for end-stage acute and chronic liver disease. Ischemia-reperfusion (I/R) injury is one of the major causes of poor graft function early after OLT, and adversely influencing graft and patient survivals. It is unknown whether I/R injury influences liver fibrogenesis. MATERIALS AND METHODS: Livers from 25 adult male Wistar rats were randomly assigned into 5 experimental groups according to the preservation solution: saline solution (SS); University of Wisconsin (UW) solution; Fructose 1, 6-biphosphate (FBP); S-Nitroso-N-Acetylcysteine (SNAC): or UW+SNAC (SNAC+UW). Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactic dehydrogenase (LDH) were determined in preservation solution samples at 2, 4, and 6 hours. After 6 hours of cold ischemia, ex situ reperfusion was applied to the liver for 15 minutes. Serum AST, ALT, LDH, and renin levels were determined. Fresh liver slices were processed for histological studies, determination of thiobarbituric acid reactive substances, catalase, and glutathione, and expression of TGF-ß1 and angiotensin II AT1 receptor. RESULTS: AST was significantly lower during cold storage with UW than with the older media (P=.001); ALT was lower in the FBP group (P=.023) and LDH was lower in the FBP and SNAC groups (P=.007). After reperfusion, serum AST, ALT, LDH, and TBARS showed no significant differences among the groups. Catalase was significantly lower in the SS and FBP groups (P=.008 and P=.006, respectively). Compared with UW, glutathione concentrations were significantly higher in SS, FBP, and SNAC 200 (P=.004). Renin levels were significantly lower in the FBP group (P=.022). No histological signs of preservation injury were observed in the hepatic sample. No expressions were detected of TGF-ß1 or AT1 receptor. CONCLUSION: In this experimental model of early reperfusion injury, preservation changes related to higher levels of renin, which suggest its role in fibrogenesis. FBP was associated with lower renin levels than other solutions including UW.

Fructose 1-6 bisphosphate versus University of Wisconsin solution for rat liver preservation: does FBP prevent early mitochondrial injury?

BACKGROUND: Fructose 1,6-biphosphate (FBP) has been shown to exert therapeutic effects in models of ischemia-reperfusion in organs other than the liver. This study compared FBP and University of Wisconsin (UW) solution during cold storage and reperfusion, among mitochondria of adult male Wistar rat livers. METHODS: Adult male Wistar rats were assigned to two groups according to the preservation solution used; UW or FBP Aspartate transaminase (AST), alanine transferase (ALT); and lactic dehydrogenase (LDH) were measured in samples of the storage solution obtained at 2, 4 and 6 hours of preservation. After 6 hours of cold storage, we reperfused the liver, taking blood samples to measure AST, ALT, LDH, and throbarbituric acid reactive substances (TBARS). Hepatic fragments were processed for histologic analysis; for determinations of TBARS, catalase, and nitric oxide as well as for mitochondrial evaluation by infrared spectroscopy. RESULTS: During cold preservation, levels of AST and LDH in the storage solution were lower among the FBP group, but after reperfusion, serum levels of AST, ALT, and LDH were higher in this group, as was catalase activity. TBARS and nitric oxide were comparable between the groups. In the UW group there was a higher amide I/amide II ratio than in the FBP group, suggesting an abnormal protein structure of the mitochondrial membrane. No signs of preservation injury were observed in any liver biopsy, but sinusoidal congestion was present in livers preserved with FBP. CONCLUSION: FBP showed a protective effect for preservation during cold storage seeming to protect the mitochondrial membrane although it did not prevent reperfusion injury.

S-nitroso-N-acetylcysteine: a promising drug for early ischemia/reperfusion injury in rat liver.

BACKGROUND/AIMS: Ischemia-reperfusion (I/R) injury is among the major causes of poor graft function early after liver transplantation that adversely influences patient survival. A variety of mediators have been implicated in the pathogenesis of I/R vascular injury, including nitric oxide (NO). Because of the beneficial effects of NO during preconditioning and reperfusion, strategies to prevent or ameliorate I/R injury through the stimulation of hepatic NO production are an area of significant clinical interest. We evaluated the role of S-nitroso-N-acetylcysteine (SNAC) as an NO donor in the prevention of liver I/R injury in an animal model. METHODS: Adult male Wistar rats were randomly assigned to 3 experimental groups containing 5 animals each: the University of Wisconsin (UW) solution group; SNAC solution group; and SNAC-containing UW solution (SNAC+UW) group. Aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) were determined in samples of the cold storage solution at 2, 4, and 6 hours of preservation. After 6 hours of cold storage, We applied a 15-minute reperfusion period. Thereafter, the reperfusion was interrupted with blood samples obtained to measure AST, ALT, LDH, and thiobarbituric acid reactive substances (TBARS). Hepatic fragments were processed for histologic analysis, and to determine of TBARS, catalase, and glutathione levels. RESULTS: During cold preservation, AST and LDH were significantly lower among the SNAC than the UW group or the SNAC+UW group (P = .004 and P = .03, respectively). ALT was comparable among the groups (P = .3). After reperfusion, serum levels of AST, ALT, and LDH, as well as of hepatic TBARS and catalase showed no differences among the groups. Glutathione concentration was lower in the SNAC and SNAC+UW group (P < .001) compared with the UW group. We did not observe histologic signs of preservation injury. CONCLUSION: The SNAC solution showed a greater protective effect to preserve rat livers during cold storage, but it was comparable with UW.

Hepatic reperfusion in rats: a new model with portal arterialization in studying early ischemia-reperfusion injury.

Isolated liver perfusion has been used to evaluate the beneficial effects of several agents. In the present study, we developed a model using a recipient rat to reperfuse harvested livers in an ex situ, in vivo recirculating system. A total of 25 reperfusion procedures using adult male Wistar rats as donors and recipients were done. The preservation of the livers was performed with University of Wisconsin solution for 6 hours. Thereafter, the liver was reperfused with blood from another rat. We believe that the model presented herein offers an alternative method to evaluate early hepatocellular damage or hepatic microcirculation.

[SAFYRE. A new concept for adjustable minimally invasive sling for female urinary stress incontinence]. / SAFYRE. Un nuevo concepto de cabestrillo ajustable mínimamente invasivo para la incontinencia urinaria por estrés femenina.

INTRODUCTION: SAFYRE is a new readjustable and minimally invasive sling for the treatment of stress urinary incontinence (SUI). Attempts to restore the normal suburethral hammock using an anatomical approach have been made in recent years. The authors report their experience with this device, which associates the efficacy of slings with readjustability. MATERIAL AND METHODS: A total of 100 consecutive patients with clinical and urodynamic diagnosis of SUI underwent SAFYRE sling procedure. The age range was from 40 to 71, mean age 63 years. Seventy-five patients (75%) presented previous failed anti-incontinence procedures. Physical clinical examination, stress test, pad use and a urodynamic study were performed before the surgery. All the patients presented symptoms of SUI and 30% also reported mild urgency. RESULTS: The average follow up period was 14 months (12-30 months). The mean operative time was of 25 minutes. Dystopia repair was performed whenever necessary, during the same procedure. The average hospital stay was 24 hours. In 3% of the implants, bladder perforation occurred. During the postoperative period, 26 patients developed urgency symptoms. During that follow up period, 92% were found to be continent, 3% reported an improvement and 5% were dissatisfied. CONCLUSION: SAFYRE is a safe and quick procedure that allows for postoperative readjustment. This technique may be an attractive alternative if the good result obtained so far proves to be long lasting.