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This study aimed the effect of n-acetylcysteine or ischemic preconditioning in hepatic and pulmonary damage after liver ischemia-reperfusion injury. Twenty-four male Wistar-EPM rats were assigned into four groups: (IR) Hepatic ischemia-reperfusion; (IPC) IPC achieved before hepatic ischemia; (NAC) Animals received NAC pretreatment; and Sham operated group. After 24 h of hepatic reperfusion, blood, liver, and pulmonary samples were evaluated. Nonparametric tests were used (P

The effect of hyperbaric oxygen (HBO) on ischemia-reperfusion injury of skeletal muscle, applied during different periods, was studied in 56 male rats. Animals were subjected to 6-h ischemia by a tourniquet over the major femoral trocanter and 4 (A) or 24 (B) h of reperfusion. HBO was carried out during 1 h in an acrylic chamber at a pressure of 2.0 ATA (100% oxygen): in the last 60 min of ischemia (II), after ischemia, during 1-h reperfusion time (III), and during the last hour of ischemia plus 1-h reperfusion (IV). Group I was the control group. After 4- or 24-h reperfusion, samples of the soleus muscle were stained by H&E and analyzed immunohistochemically. No interstitial hemorrhage, neutrophil infiltrate, or cellular necrosis were induced by HBO. The apoptosis index did not differ among the groups. HBO reduced morphologic alterations and promoted better results when administered in the ischemia plus reperfusion period (GIV)., (Copyright (c) 2007 Wiley-Liss, Inc. Microsurgery 2007.)

Morphometric evaluation of the fetal intestinal graft in the late post-transplant period was done by using C57BL/6 mice. Under anesthesia, after hysterotomy, a transversal laparotomy was done in the fetus to harvest all intestines. Grafts, cleaned from its mesentery, and divided were transplanted into the preperitoneum space, from male mice, C57BL/6 strain. Thirty days after, mice were killed, and the graft was analyzed with HE stain and S-100 protein. All grafts as well as fetal and adult intestines were evaluated as controls. All developed grafts showed muscular layer and positivity for S-100 protein as the adult intestines. The goblet cells, absent in fetal intestines, were in larger number in isogeneic grafts than in adult intestines, even with lower villus. These findings showed sharp progress of the isogeneic graft from fetal to adult intestine, suggesting that they can be viable and might be functionally appropriate in the late period after transplantation., (Copyright (c) 2007 Wiley-Liss, Inc. Microsurgery 2007.)

Breast reconstruction after cancer treatment is based on the circulation of pedicle and microvascular flaps. This article aimed to verify the effect of tamoxifen (TMX) pretreatment in arterial anastomosis in rats. Twenty female Wistar rats were equally divided into two groups. TMX (0.3 mg/kg) was administered to the experimental group for 2 weeks orally. After this period, the right femoral artery was sectioned and a terminoterminal anastomosis performed. The same procedure was done in the control group, except that the animals received the vehicle without TMX. One week later, the femoral arteries were inspected for flow through the anastomosis, and the vessel near it was sent to light microscopic examination. It was observed mild vasculite in both groups. The intimal thickness and total vessel wall in the TMX-treated group was significantly higher. A real thrombotic effect upon the arterial vascular anastomosis was not observed, eventhough, TMX induced intimal hyperplasia., (Copyright (c) 2007 Wiley-Liss, Inc. Microsurgery 2007.)

To examine the apoptosis expression in the intestinal mucosa in accordance of different periods of hyperbaric oxygen (HBO) treatment, rats were submitted to 60 min of mesenteric artery and vein ischemia and 60 min of reperfusion occlusion. A group (G-IR) was the control and HBO was applied in the ischemia (GHBO-I), reperfusion (GHBO-R), and ischemia and reperfusion time (GHBO-IR). After 60 min of reperfusion, samples of small bowel were prepared for immunohistochemical expression of caspase-3. The expression of caspase-3 was significantly inferior when HBO was administered in the ischemia (0.16 +/- 0.01) in comparison with the control (0.70 +/- 0.08), but HBO in the further reperfusion (0.84 +/- 0.03) or both ischemia and reperfusion time (0.42 +/- 0.05) was significantly worse. There was a connection between HBO, small bowel I/R injury, and mucosa apoptosis. The favorable effect was obtained when HBO was administered early in the ischemia time., (Copyright (c) 2007 Wiley-Liss, Inc. Microsurgery 2007.)

In previous work, it was shown that gangliosides (Gang) have an inhibitory effect on lymphocyte proliferation as well as on delayed-type hypersensitivity response and mixed lymphocyte reaction. Therefore, we decided to examine the effect of gangliosides in acute allorejection after fetal intestinal transplantation. We used two female C57BL/6 mice on pregnancy day 19 as a source of fetal intestine. All animals were anesthetized with ketamine (70 mg/kg) and xylazine (10 mg/kg), intramuscularly. We harvested intestinal segments of 1 cm to transplant into BALB/c and C57BL/6 mice (male, weighing around 20 g) used as recipients. They were divided into groups of six animals each: isogeneic and allogeneic without treatment, or treated with tacrolimus 1 mg/kg/day, or gangliosides 3 and 9 mg/kg/day, during 7 days posttransplantation, intramuscularly. On postoperative day 7, intestinal grafts were collected and fixed in 10% formalin solution. Using an anesthetic overdose as euthanasia, we removed the intestinal grafts. Tissue samples were stained with hematoxylin-eosin for histological analysis regarding grafts development (D) and rejection (R) aspects. Data were analyzed by the Kruskal-Wallis test, considering P < or = 0.05 as significant. In the isogeneic and tacrolimus groups, we observed a very good degree of development (D = 9 +/- 0.5; D = 9 +/- 0.4, respectively), but a severe degree of rejection (R = 15 +/- 1.3) and a low degree of development (D = 1 +/- 0.8) in animals without treatment. The ganglioside groups showed D = 5 +/- 1.6 and R = 13 +/- 3.3, and D = 7 +/- 2.9 and R = 9 +/- 1.9, for the 3-mg and 9-mg groups, respectively. There was a statistically significant difference between the ganglioside groups and allogeneic groups without treatment. Based on the above data, we conclude that avascular fetal intestine transplantation is a good experimental model for studying immunological events, and that gangliosides only partially modulate the allorejection response, allowing intestinal development, mainly at the highest ganglioside dose. Maybe immunomodulation would be better observed by using isolated types of gangliosides or association with other immunosuppressive drugs., (Copyright 2006 Wiley-Liss, Inc.)

We investigated histopathological changes following murine fetal intestinal transplantation. Fetal intestine, obtained from a pregnant C57BL/6 mouse, was transplanted into BALB/c and C57Bl/6 mice. Recipients were divided into three groups: isogeneic, and allogeneic treated with 3 mg/kg/day gangliosides (Allo-a) or 9 mg/kg/day (Allo-b). One week after transplant, all grafts showed good viability, confirmed by cellular mitosis in the mucosa and a well-defined propria muscular layer. Isogeneic grafts showed a thicker muscular layer than in the Allo-a (P = 0.02) and Allo-b (P = 0.004) groups. There was no difference in number of mitotic cells among groups. Goblet cells were significantly reduced in allografts treated with 3 mg gangliosides (P = 0.013) or 9 mg gangliosides (P = 0.002) compared to isografts. Villi height was similar in all studied groups. There was no difference in positivity of the enteric nervous system among groups. Atrophy was more common in the allogeneic groups, suggesting that isografts had better development than allografts treated with gangliosides. (, (Copyright 2006 Wiley-Liss, Inc.)

Previous studies described controversial opinions about pediatric tracheotomy concerning type of tracheal incision and long-term results, which remain as important research subjects. Experimental studies on rat tracheas are scarce, probably because of technical difficulties related to the structures' small dimensions. As many rat organ and system operative procedures were studied successfully by using microsurgical techniques, we decided to develop a pediatric tracheotomy model in growing rats which would permit long-term studies. Forty-four Wistar EPM-1 growing rats weighing 86 g and aged 35 days were divided into three groups: submitted to longitudinal, transverse, and segment excision of the trachea. Under sterile technique and intramuscular anesthesia (ketamine/xylazine), the trachea was exposed and incised, according to group, and a hand-made endotracheal cannula was inserted into the organ. This cannula was assembled using a segment of 1.5-cm-long 3 French silicone catheter passed through hexagonal-shaped silicone screen. The tracheal cannula was removed after 7 days, when we evaluated body weight, secretions, and dehiscence. In conclusion, this microsurgical tracheotomy model in growing rats is feasible, allowing studies on long-term repercussions of pediatric tracheotomy., (Copyright 2003 Wiley-Liss, Inc.)

Our objective was to evaluate intestinal ischemia-reperfusion injury in growing rats, modulated by hypothermia (I/RH) and N-acetylcysteine (NAC). We used 30 EPM-1 Wistar male rats, aged around 35 days, weighing 90 g. Rats were randomized into 5 groups with 6 animals in each: I/RH group, intestinal ischemia under hypothermia for 40 min and reperfusion for 30 min; I/RH-NAC group, same procedure but adding NAC (150 mg x kg(-1)), previously with ischemia; S-H group, topic hypothermia for 40 min, and observation for 30 min; I/R H-Ve group; and S-NAC group, NAC administration and observation for 70 min. All animals were heparinized and anesthetized with ketamine (60 mg kg(-1)) and xylazine (10 mg kg(-1)) intramuscularly. Surgical procedures were done under microsurgical technique (augmentation, 10x). After laparotomy, the superior mesenteric artery was dissected and clamped to promote ischemia. Topic hypothermia was obtained by using plastic bags at 4 degrees C, changed every 10 min. Rats were sacrificed by exsanguination, and blood samples were utilized to measure D(-)lactate. Intestinal fragments were removed for morphological study. Statistical analysis was done with nonparametric tests (P

The aim of this study was to evaluate the early morphological development and acute rejection process in fetal intestine allografts. Grafts from C57BL/6 fetal intestines were implanted in an avascular form in BALB/C recipients. A syngeneic group of animals was used to compare the evolution. The allogeneic recipients were distributed in 6 groups, according to the day of sacrifice (3rd, 4th, 5th, 6th, 7th, and 10th postoperational day (POD)) and the control group on the 2nd, 5th, and 7th POD. These grafts were stained with hematoxylin and eosin for histological evaluation, in agreement with the classification of Auber et al. (Chirurgie 123:122-130, 1998). Data showed a progressive development of the graft until POD 5. On POD 3 and 4, a top grade of development and an initial rejection were observed. From POD 5-7 and on POD 10, the acute rejection reaction was more important than the development process. The higher level of rejection was observed on POD 10, and it was similar to the 7th POD. Our results showed good graft development until POD 5. After that, the acute rejection response impeded analysis of the development process., (Copyright 2003 Wiley-Liss, Inc.)

Occult ischemia of the mobilized stomach is usually related to the dehiscence of an esophagogastric anastomosis. The principle of ischemic conditioning was studied to verify its clinic use. This study aims to evaluate progressively the tissue perfusion of the stomach in ischemic conditioning, establishing the best moment for gastric transposition. Twenty-four male EPM-1 Wistar rats were used, which also underwent partial desvacularization of the stomach by ligature of the left gastric vessels. Tissue perfusion was measured through flowmetry by laser Doppler (tissue perfusion unit; TPU) in the antrum (10 mm distal from the cardiac region). This measurement was done before (baseline) and immediately after the ligature, and on different postoperative days (POD) (days 3, 7, 10, and 14). A statistical analysis was done with nonparametric tests (P

Previous studies demonstrated that some immunosuppressive agents inhibit arterial intimal hyperplasia. Our previous studies demonstrated that gangliosides (Gang) have an immunosuppressive effect on as well as an anti-inflammatory role in the wound-healing process. Therefore, we decided to examine the effect of Gang on intimal hyperplasia. Twenty Wistar isogenic rats received a transverse division of the anterior wall of the femoral artery, followed by suturing using mononylon 10-0 under surgical microscopy and were then divided into two groups: Gang group, 3 mg/kg per day of Gang, and control group, vehicle, intramuscularly from surgery to death (1 and 3 weeks, respectively). Concentric intimal hyperplasia was observed in arteries stained by hematoxylin-eosin in control and Gang groups. However, the media layer did not demonstrate any major alterations. After 3 weeks, the Gang group showed more intimal hyperplasia than the control group. Therefore, because intimal hyperplasia worsened in the presence of Gang after 3 weeks, further studies will be necessary to clarify its role in intimal proliferation., (Copyright 2001 Wiley-Liss, Inc.)

Microcirculatory disturbances have been related to a decrease in survival after liver transplant. Because innervation is involved in liver hemodynamics regulation, we decided to evaluate microcirculatory hepatic perfusion. Thirty rats were divided into three groups: denervated (DG), hepatic microsurgical denervation; manipulated (MG), hepatic manipulation; control (CG), laparotomy. Hepatic microcirculation was assessed in the median lobe using laser Doppler flowmetry in the following moments: T(0), after laparotomy and T(1), after denervation; and in the following moments after denervation: T(2), 10 minutes, T(3), 20 minutes, T(4), 30 minutes, T(5), 1 hour, T(6), 1.5 hours, and T(7), 2 hours for DG, and in same moments for MG and CG. DG showed a decrease in hepatic perfusion for 20 minutes after denervation, different from MG and CG. After that, there was recovery in hepatic perfusion in MG and DG (Kruskal-Wallis and Friedman tests). Therefore, denervation and manipulation alter hepatic microcirculation, but denervation promotes a more severe decrease than manipulation., (Copyright 2001 Wiley-Liss, Inc.)