Cyclosporine reduces the spleen dimensions in rabbits

Purpose To assess the influence of prolonged cyclosporine use on the macro- and microscopic morphology of the spleen. Methods 16 adult rabbits were divided into two groups (n = 8): group 1 a placebo group, which was followed-up over a period of nine months; group 2 which had taken an oral dose of cyclosporine (10 mg·kg1·day1) over nine months. At the end of this period, the splenic histoarchitecture of all animals was evaluated and the splenic corpuscles were measured. Results The spleens of the first group presented normal characteristics and dimensions. The second group, however, had a reduction in all dimensions and its tissue texture had become soft. The white pulp and the perivascular sheath had become reduced in size and the number of lymphoid follicles had also fallen (p = 0.002), manifesting less splenic corpuscles (p = 0.0012) and lymphocyte nuclear pigments (p = 0.03). Conclusions Prolonged use of cyclosporine reduces the spleen size, transforming it into a soft organ associated with a decrease in white pulp, perivascular sheath, lymphoid follicles and nuclear pigments in rabbits.(AU)

Effects of homologous and heterologous rich platelets plasma, compared to poor platelets plasma, on cutaneous healing of rabbits

Purpose: To evaluate and compare the effects of homologous and heterologous PRP (Platelet-Rich Plasma) on the quality and speed of skin wound healing, compared to Poor Platelet Plasma (PPP). Methods: Twenty-one male adult rabbits were used; two for preparing homologous PRP, with the rest of them separated randomly in three groups, according to the treatment received: PPP - control (n=5), homologous PRP (n=7), heterologous (n=7). Excisional skin wounds were made on the back of the animals, for the application of homologous and heterologous PPP and PRP. At the 14th post-operative day (POD), the animals were subjected to a new wound, and the treatments were inverted. The wounds were evaluated macroscopically and histologically. Results: A larger percentage of scar retraction was observed on the group treated with heterologous PRP, compared to homologous PRP, at the third POD, an increase of 25.03% (p=0.01). No other statistically significant differences among treatments were observed. Among every group, skin healing was efficient, without local adverse effects. Conclusions: Heterologous PRP contributed with more tissue retraction at the beginning of the wound healing process. After this, there were no differences on the wound healing skin process treated with PRP or PPP. However, our findings suggest the presence of others plasmatic factors, besides platelets, which could also contribute to the wound healing process, and thus, should be further investigated.(AU)

Effects of different periods of gastric ischemia on liver as a remote organ

Purpose:To evaluate the hepatic changes associated with gastric ischemia.Methods:Thirty male rabbits were studied, distributed in 3 groups (n=10). Group 1: ligature and section of the gastric vasculature and removal of the liver after three hours; Group 2: ligature and section of the gastric vasculature and removal of the liver after 6 hours; Group 3: ligature and section of the gastric vasculature and removal of the liver after 12 hours. Blood samples were collected immediately before surgery and after the determined time of ischemia in each group to evaluate the hepatic function. After the death of the rabbits, the liver was removed for macro and microscopic study.Results:An increase in aminotransferases and bilirubin occurred in groups 2 and 3. Total protein and albumin diminished in all of the animals. All of the rabbits from groups 2 and 3 presented hepatocellular necrosis.Conclusion:The devascularization of the stomach for a period of above three hours is associated with hepatic morphological and functional disorders.(AU)

Effects of chronic consumption of green tea on weight and body fat distribution of Wistar rats evaluated by computed tomography

Purpose: To evaluate the effects of chronic consumption of green tea on body weight and distribution of visceral fat by Computed tomography in female Wistar rats. Methods: Wistar rats were divided into control group (n = 5), which received water and feed ad libitum, and green tea group (n = 8), in which water has been replaced by green tea. The animals were weighed weekly and Computed Tomography was used at the beginning (1st week) and end (18th week) of the experiment for evaluating the distribution of visceral fat. The animals were followed for 18 weeks. Results: There was no significant difference in body weight between the groups. However, there was significant difference in visceral fat area. The green tea group had less visceral fat area at the end of the experiment, 3.67 ± 1.2 cm2, while the control group showed an area of 6.25 ± 2.2 cm (p = 0.00). Conclusions: Chronic consumption of green tea leads to decreased visceral adipose tissue area.(AU)

Comparative study of intraperitoneal adhesions related to light-weight polypropylene mesh and type I polymerized and purified bovine collagen coated light-weight polypropylene mesh in rabbits

Purpose: To compare the effectiveness of light-weight polypropylene mesh coated with polymerized and purified bovine type I collagen (Surgidry HNB) in the treatment of abdominal wall defect and the degree of adhesion formation. Methods: Two types of polypropylene mesh were implanted after creation of defect measuring 6.0cm X 5.5cm in the anterior abdominal wall of 32 male New Zealand breed rabbits, divided in two groups (n = 32): (1) light-weigh macroporous polypropylene, (2) type I polymerized and purified bovine collagen coated light-weigh macroporous polypropylene. These animals were further accessed for adhesions, histological evaluation of inflammation and walls thickness. Results: The percentage of the area adhered in group 1 (62.31 ± 16.6) was higher compared to group 2 (22.19 ± 14.57) (p 0.05). There was an association between the percentage of the covered area by adhesions and the type of adhesion, toughness and the scores obtained by the adhesion score by correlation analysis (p <0.05). There was no difference between the groups in any variables in relation to the degree of inflammation. Conclusion: The purified type I bovine collagen coated light-weigh polypropylene mesh showed to be effective in the repair of abdominal wall defects and reducing adhesion formation.(AU)

Treatment of abdominal wall hernia with suture, or polypropylene, or collagen prosthesis

PURPOSE:To develop an experimental model for incisional hernias and to compare morphological and functional aspects of hernia repairs by suture, polypropylene mesh and collagen mesh.METHODS:A defect measuring 7cm x 2cm was created in the anterior abdominal of 28 New Zealand male rabbits, divided into four groups (n = 7): (1) control, (2) suture of the anterior sheath of the rectus abdominal muscle, (3) setting of polypropylene mesh, and (4) setting of collagen mesh. On the 90th postoperative day, the animals were examined to verify the presence of incisional hernia. Samples of abdominal wall and scar were collected for histological study.RESULTS:Incisional hernia was identified in 85.7% of the control group, 57.1% of the suture group, 42.9% of the collagen mesh group, and none in the polypropylene mesh group (p = 0.015). Mesh exposure could be identified in 71.4% of the animals in group 3 and in no animal in group 4 (p = 0.021). The polypropylene mesh is effective in the treatment of abdominal wall defects, causing an intense inflammatory reaction.CONCLUSION:The collagen mesh is biocompatible, producing a minimal inflammatory reaction, but fails in the treatment of abdominal wall defects.(AU)

Autologous and allogeneic ovarian orthotopic transplantation: morphologic, endocrinologic and natural pregnancy assessment

PURPOSE: To assess pregnancy of rabbits submitted to bilateral ovariectomy and orthotopic allogeneic or autologous intact and sliced ovarian transplantation without a vascular pedicle and to determine the morphofunctional aspects of the transplanted ovaries. METHODS: Fifty-six female rabbits were studied. The ovaries were removed and orthotopically transplanted or replaced without vascular anastomoses: Group 1 (n=8), only laparotomy and laparorrhaphy, Group 2A (n=8) intact ovaries were transplanted on both sides, Group 2B (n=8) both ovaries were sliced and orthotopically transplanted, Group 2C (n=8), an intact ovary was transplanted on one side and a sliced ovary on the other side. In Group 3 the ovaries were reimplanted according to the procedure and subgroups described for Group 2. Three months later, the animals were paired with males for copulation. Estradiol, progesterone, FSH and LH hormone levels were assessed. A histologic study was carried out, and the number of pregnancies and litters were also determined. Chi-square test compared the number of pregnancies and litters. One-way ANOVA and the Tukey-Kramer tests compared the hormonal dosages. RESULTS: Pregnancies occurred in seven (87.5%) rabbits of Group 1, in three rabbits (37.5%) of Groups 2A and 3A, in four rabbits (50%) of groups 2B, 3B and 3C, and in five (62.5%) of group 2C. Normal hormone serum levels and histology confirmed the vitality of all ovaries. CONCLUSION: Orthotopic allogeneic and autologous ovarian transplantation without a vascular pedicle is viable in rabbits, and preserves their hormonal levels and fertile functions.(AU)

Evaluation of peritoneal reinfection after fecal peritonitis / Avaliação da reinfecção peritoneal após peritonite fecal

PURPOSE: To investigate the role of a previous abdominal infection on peritonitis. METHODS: Twenty-seven adult female Wistar rats were submitted to fecal peritonitis by an intraperitoneal injection of a solution of rat feces. The animals were divided into three groups (n = 9 each): Group 1 - control - intraperitoneal injection of an amount of fecal solution known to be lethal (10 ml/kg), Group 2 - reinfection - intraperitoneal injection of an amount of fecal solution known not to be lethal (2 ml/kg) followed by an injection of fecal solution (10 ml/kg) 30 days later, Group 3 - late reinfection - intraperitoneal injection of 2 ml/kg feces followed by an injection of 10 ml/kg four months later. RESULTS: All animals in Group 1 died within seven days after injection of the fecal solution. In contrast, in the pre-infected Group 2 only one animal died 24 hours after injection of the fecal solution (10 ml/kg). In Group 3, eight of the nine animals in each subgroup died over a period of seven days. The difference in survival time between groups 1, 2 and 3 was for p = 0.0042 (logrank test). CONCLUSIONS: Milder peritoneal sepsis due to fecal infection raises the organic resistance to a new more intense fecal contamination occuring after a short period of time. However, this protection did not persist over a prolonged period of time.(AU)

OBJETIVO: Investigar o efeito de uma nova infecção peritoneal após realização de peritonite fecal prévia. MÉTODOS: Foram utilizados 27 ratos fêmea Wistar adultos submetidos à peritonite fecal com injeção intraperitoneal de uma solução de fezes de ratos. Os animais foram distribuidos em três grupos (n = 9): Grupo 1 - controle: injeção intraperitoneal de solução de fezes com uma quantidade sabidamente letal (10 ml/kg); Grupo 2 - reinfecção: injeção intraperitoneal de solução de fezes com uma quantidade sabidamente não letal (2 ml/kg) e, após 30 dias, injeção de solução de fezes (10 ml/kg); Grupo 3 - reinfecção tardia: injeção intraperitoneal de fezes a 2ml/kg e, após quatro meses, injeção de 10ml/kg. RESULTADOS: Todos os animais do Grupo 1 morreram dentro de sete dias após a injeção da solução de fezes. Em contraste, no grupo de reinfecção precoce Grupo 2 apenas um animal morreu 24 horas após a injecção da solução de fezes (10 ml / kg). No Grupo 3, oito dos nove animais morreram durante um período de sete dias. A diferença no tempo de sobrevivência entre os grupos 1, 2 e 3 foi de p = 0,0042 (teste de logrank). CONCLUSÕES: Uma sepse peritoneal menor por fezes eleva a resistência orgânica a nova contaminação fecal mais intensa que ocorra após um período curto. Contudo, essa defesa não persiste por tempo mais prolongado.(AU)

Influence of local or systemic corticosteroids on skin wound healing resistance / Influência de corticosteróide local e sistêmico no processo cicatricial cutâneo

PURPOSE: To compare the resistance of skin wound healing of mice submitted to local or systemic hydrocortisone administration, in different postoperative periods. METHODS: An incision and suture was performed on the thoracic skin of 130 male mice: Group 1 (n = 10) resistance of the integer skin; Group 2 (n = 30) submitted only to skin incision and suture; Group 3 (n = 30) skin incision and suture followed by administration of saline fluid; Group 4 (n = 30) skin incision and suture followed by administration of local hydrocortisone; Group 5 (n = 30) skin incision and suture followed by administration of systemic hydrocortisone. The resistance of the wound healing and the weight of the animals were studied on the seventh, 14th and 21st postoperative days. Histological examination was also performed. RESULTS: The mice that received corticoid (groups 4 and 5) presented significant decreasing on their weight (p = 0.02). The Groups 3, 4 and 5 showed lower scar resistance than Group 2 on the seventh postoperative day (p < 0.05). On the 14th and 21st days, there was no difference on the skin would healing resistance (p > 0.05). CONCLUSION: Administration of hydrocortisone in mice is responsible for weight decreasing and reduction of the skin wound healing resistance during the first postoperative week.(AU)

OBJETIVO: Comparar a resistência cicatricial cutânea de camundongos submetidos a administração de hidrocortisona por diferentes vias e em distintos períodos pós-operatórios. MÉTODOS: Foram estudados 130 camundongos machos submetidos à incisão e sutura de pele da região dorsal do tórax: Grupo 1 (n = 10) resistência da pele íntegra; Grupo 2 (n = 30) incisão da pele e sutura, sem administração de corticóide; Grupo 3 (n = 30) incisão da pele e sutura, seguidas de injeção local de solução salina; Grupo 4 (n = 30) incisão da pele e sutura, seguidas de injeção local de hidrocortisona e Grupo 5 (n = 30) incisão da pele e sutura, seguidas de injeção intraperitoneal de hidrocortisona. Foram avaliadas a resistência cicatricial da pele e a variação ponderal no sétimo, 14º e 21º dias pós-operatórios, bem como sua histologia. RESULTADOS: Os camundongos que receberam hidrocortisona tiveram decréscimo ponderal (p = 0,02). Quanto à resistência cicatricial da pele, os Grupos 3, 4 e 5 apresentaram valor inferior ao Grupo 2, no sétimo dia pós-operatório (p = 0,031). No 14º e 21º dias, não houve diferença entre as tensões cicatriciais. CONCLUSÃO: A administração de hidrocortisona provoca redução ponderal em camundongos e a resistência cicatricial cutânea é menor na primeira semana pós-operatória.(AU)

Is there a relationship between lipids metabolism and splenic surgeries? / Existe relação entre o metabolismo lipídico e as cirurgias esplênicas?

PURPOSE: To assess the influence of spleen surgeries (splenectomy, presence of spleen and after conservative surgeries) on lipids metabolism. METHODS: Fifty female Wistar rats of similar weight and age were divided into five groups submitted to the following procedures: Group 1 - control, with an intact spleen; Group 2 - sham operation, Group 3 - total splenectomy; Group 4 - subtotal splenectomy, and Group 5 - total splenectomy complemented with autogenous spleen tissue implants. Four months after the interventions, serum triglycerides, total cholesterol and fractions (VLDL-cholesterol, LDL-cholesterol, HDL-cholesterol) were determined. The results for the four groups were compared by analysis of variance followed by the Tukey-Kramer test, with the level of significance set at p<0.05. RESULTS: There were no differences between groups 1, 2, 4 and 5. In the animals submitted to total splenectomy, total cholesterol (p=0.0151) and LDL-cholesterol fraction concentrations (p<0.0001) were higher, whereas HDL-cholesterol fraction concentrations were lower (p=0.0026) than those detected in the other groups. There was no difference in triglycerides (p=0.1571) or VLDL-cholesterol (p=0.2527) between groups. CONCLUSION: Splenectomy is related to changes in the lipid metabolism that are reverted by autogenous spleen tissue implants.(AU)

OBJETIVO: Avaliar a influência das cirurgias esplênicas (esplenectomia, presença do baço e cirurgias conservadoras) sobre o metabolismo de lipídios. MÉTODOS: Foram utilizados 50 ratos fêmea Wistar de peso e idades semelhantes distribuídas em quatro grupos: Grupo 1 - controle, com baço íntegro; Grupo 2 - laparotomia e laparorrafia, Grupo 3 - esplenectomia total; Grupo 4 - esplenectomia subtotal e Grupo 5 - esplenectomia total complementada por implantes de tecido esplênico autógeno. Após quatro meses, foram dosados os níveis séricos de triglicérides, colesterol total e suas frações VLDL, LDL, HDL. Os resultados dos quatro grupos foram comparados entre si pela análise de variância, seguido pelo teste de Tukey-Kramer, com significância para p<0,05. RESULTADOS: Não houve diferença entre os grupos 1, 2, 3 e 4. Nos animais submetidos à esplenectomia total, as concentrações de colesterol total (p=0,0151) e de sua fração LDL (p<0,0001) foram maiores, enquanto a fração HDL foi menor (p=0,0026) do que as encontradas nos demais grupos. Não houve diferença entre os grupos com relação aos triglicérides (p=0,1571) e VLDL (p=0,2527). CONCLUSÃO: A esplenectomia leva a alterações do metabolismo lipídico que são revertidas pelo implante de tecido esplênico autógeno.(AU)