Paulo Fernandes Saad

Sildenafil citrate protects skeletal muscle of ischemia-reperfusion injury: immunohistochemical study in rat model

PURPOSE To investigate the effect of sildenafil citrate (SC) on skeletal muscle ischemia-reperfusion (IR) injury in rats. METHODS Adult male Wistar rats were randomized into three groups: vehicle-treated control (CTG), sildenafil citrate-treated (SCG), and sham group (SG). CTG and SCG had femoral artery occluded for 6 hours. Saline or 1 mg/kg of SC was given 5.5 hours after occlusion. SG had a similar procedure without artery occlusion. Soleus muscle samples were acquired 4 or 24h after the reperfusion. Immunohistochemistry caspase-3 analysis was used to estimate apoptosis using the apoptotic ratio (computed as positive/negative cells). Wilcoxon rank-sum or Kruskal-Wallis tests were used to assess differences among groups. RESULTS Eighteen animals were included in the 4h reperfusion groups and 21 animals in the 24h reperfusion groups. The mean apoptotic ratio was 0.18 ± 0.1 for the total cohort; 0.14 ± 0.06 for the 4h reperfusion groups and 0.19 ± 0.08 for the 24h groups (p<0.05). The SCG had lower caspase-3 ratio compared to the control groups at the 24h reperfusion time point (p<0.05). CONCLUSION Sildenafil citrate administration after the onset of the ischemic injury reduces IR-induced cellular damage in skeletal muscle in this rat hindlimb ischemia model.

Effect of hyperbaric oxygen therapy combined with autologous platelet concentrate applied in rabbit fibula fraction healing

OBJECTIVES: The purpose is to study the effects of hyperbaric oxygen therapy and autologous platelet concentrates in healing the fibula bone of rabbits after induced fractures. METHODS: A total of 128 male New Zealand albino rabbits, between 6–8 months old, were subjected to a total osteotomy of the proximal portion of the right fibula. After surgery, the animals were divided into four groups (n = 32 each): control group, in which animals were subjected to osteotomy; autologous platelet concentrate group, in which animals were subjected to osteotomy and autologous platelet concentrate applied at the fracture site; hyperbaric oxygen group, in which animals were subjected to osteotomy and 9 consecutive daily hyperbaric oxygen therapy sessions; and autologous platelet concentrate and hyperbaric oxygen group, in which animals were subjected to osteotomy, autologous platelet concentrate applied at the fracture site, and 9 consecutive daily hyperbaric oxygen therapy sessions. Each group was divided into 4 subgroups according to a pre-determined euthanasia time points: 2, 4, 6, and 8 weeks postoperative. After euthanasia at a specific time point, the fibula containing the osseous callus was prepared histologically and stained with hematoxylin and eosin or picrosirius red. RESULTS: Autologous platelet concentrates and hyperbaric oxygen therapy, applied together or separately, increased the rate of bone healing compared with the control group. CONCLUSION: Hyperbaric oxygen therapy and autologous platelet concentrate combined increased the rate of bone healing in this experimental model.

Carotid stenosis: what is the high-risk population?

OBJECTIVE: Prevention is the best treatment for cerebrovascular disease, which is why early diagnosis and the immediate treatment of carotid stenosis contribute significantly to reducing the incidence of stroke. Given its silent nature, 80% of stroke cases occur in asymptomatic individuals, emphasizing the importance of screening individuals with carotid stenosis and identifying high-risk groups for the disease. The aim of this study was to determine the prevalence and the most frequent risk factors for carotid stenosis. METHODS: A transversal study was conducted in the form of a stroke prevention campaign held on three non-consecutive Saturdays. During the sessions, carotid stenosis diagnostic procedures were performed for 500 individuals aged 60 years or older who had systemic arterial hypertension and/or diabetes mellitus and/or coronary heart disease and/or a family history of stroke. RESULTS: The prevalence of carotid stenosis in the population studied was 7.4%, and the most frequent risk factors identified were mean age of 70 years, carotid bruit, peripheral obstructive arterial disease, coronary insufficiency and smoking. Independent predictive factors of carotid stenosis include the presence of carotid bruit or peripheral obstructive arterial disease and/or coronary insufficiency. CONCLUSIONS: The population with peripheral obstructive arterial disease and/or coronary insufficiency and carotid bruit should undergo routine screening for carotid stenosis.

Inferior gluteal artery pseudoaneurysm related to intramuscular injection

Highlights • A case of pseudoaneurysm of the IGA following intramuscular injection in the buttock.• Importance careful physical examination in order to avoid misdiagnosis.• Diagnosis and therapy are facilitated by catheter angiography.

Effects of ischemic preconditioning and cilostazol on muscle ischemia-reperfusion injury in rats

PURPOSE To evaluate effects of ischemic preconditioning and Cilostazol on muscle ischemia-reperfusion injury. METHODS Male Wistar rats were submitted to muscle ischemic and reperfusion injury (4h of the left common iliac artery occlusion followed by 1h of reperfusion). Five experimental groups were constituted: Control group (n=4); Ischemia-Reperfusion (IR, n=5); Ischemic preconditioning group (IP, n=6); Ischemia-Reperfusion group treated with cilostazol (IRCi, n=6) and Ischemic preconditioning group treated with cilostazol (IPCi, n=6). At the end, left gracile muscle was removed and embedded in paraffin. Histopathology, neutrophil infiltration, myocyte necrosis and edema were analyzed. RESULTS When compared with the control group, IR group showed increased neutrophil infiltration, severe necrosis and edema. There was significant difference between myocytes necrosis of IR group and IP group. There was no difference between the histopathological changes between IP, IRCi and IPCi groups. CONCLUSIONS The model of IR caused severe muscle injury in the rat hind limb and ischemic preconditioning has a protective effect, reducing myocyte necrosis, however, treatment with cilostazol and also the association between cilostazol and preconditioning has no protective effect on the skeletal muscle subjected to ischemia and reperfusion injury.

Effect of N-acetylcysteine on pulmonary cell death in a controlled hemorrhagic shock model in rats

PURPOSE To evaluate the effect of N-acetylcysteine (NAC) combined with fluid resuscitation on pulmonary cell death in rats induced with controlled hemorrhagic shock (HS). METHODS Two arteries (MAP calculation and exsanguination) and one vein (treatments) were catheterized in 22 anesthetized rats. Two groups of male albino rats were induced with controlled HS at 35mmHg MAP for 60 min. After this period, the RL group was resuscitated with Ringers lactate and the RL+NAC group was resuscitated with Ringers lactate combined with 150mg/Kg NAC. The control group animals were cannulated only. The animals were euthanized after 120 min of fluid resuscitation. Lung tissue samples were collected to evaluate the following: histopathology, TUNEL and imunohistochemical expression of caspase 3. RESULTS RL showed a greater number of cells stained by TUNEL than RL + NAC, but there was no change in caspase 3 expression in any group. CONCLUSION N-acetylcysteine associate to fluid resuscitation, after hemorrhagic shock, decreased cell death attenuating lung injury.

Effect of N-acetylcysteine in hearts of rats submitted to controlled hemorrhagic shock

Introduction Pharmacological therapy is a strategy for the prevention of complications associated with ischemia and reperfusion injury that occurs after volume replacement in the treatment of hemorrhagic shock. Objective The aim of this study was to evaluate the effect of N-acetylcysteine associated with fluid resuscitation in cardiac injury in a rat hemorrhagic shock model. Methods Mice Wister male rats were randomly and subjected to controlled hemorrhagic shock for 60 min. and then, subjected to resuscitation with Ringer lactate. In a group of six animals, 150mg/kg of N-acetylcysteine were added to fluid volume replacement. The animals were observed for 120 min and after this period, were euthanized and cardiac tissue was collected for histopathological analysis and measurement of thiobarbituric acid reactive substances and pro-and anti-inflammatory interleukin. Results Cardiac tissue of the group treated with N-acetylcysteine showed lower concentrations of thiobarbituric acid reactive substances (0.20±0.05 vs. 0.27±0.05, P=0.014) and reduced histopathological damage and edema when compared to the group whose volume replacement occurred only with Ringer lactate. There was no difference in the expression of cytokines interleukin 6 (2,138.29±316.89 vs. 1,870.16±303.68, P=0.091) and interleukin 10 (1.019,83±262,50 vs. 848.60±106.5, P=0.169) between the treated groups. Conclusion The association of N-acetylcysteine on volume replacement attenuates oxidative stress in the heart, as well myocardial damage and edema, but does not modify the expression of inflammatory cytokines.

Dilatation of Common Iliac Arteries after Endovascular Infrarenal Abdominal Aortic Repair with Bell-Bottom Extension

Objective Endovascular techniques to treat abdominal aortic aneurysms results in lower morbidity and mortality rates. However, dilation of the common iliac arteries prevents adequate distal sealing, which compromises the procedure success. The aim of this study is report the long-term outcomes of patients with abdominal aortic aneurysms associated with aneurysm of the common iliac artery following endovascular repair using a bifurcated bell-bottom stent graft. Methods This is a retrospective study that evaluated patients treated with bifurcated bell-bottom extension stent grafts to repair an infrarenal abdominal aortic aneurysm and who had at least one common iliac artery with dilatation > 1.5 cm for at least 12 months after the endovascular intervention. Results Thirty-eight patients with a mean age of 70.4±8.2 years were included. Stent graft placement was followed by dilation of the common iliac artery aneurysms in 35.3% of cases; endoleak and reoperation rates were 17.6% and 15.7%, respectively. Younger patients showed a higher rate of artery diameter increase following the procedure. The average arterial dilation was 16% in the first year, 29% in the second year, 57% in the third year and 95% from the fourth year until the end of follow-up. Conclusion Repair of infrarenal abdominal aortic aneurysms with bifurcated bell-bottom type stents when there is common iliac artery dilation is a good therapeutic option to preserve hypogastric flow. The rate of endoleak was 17.6%, and 15.7% of cases required reoperation. Younger patients are more likely to experience dilation of the common iliac artery after the procedure.

Trashepatic left gastric vein embolization in the treatment of recurrent hemorrhaging in patients with schistosomiasis previously submitted to non-derivative surgery

CONTEXT Non-derivative surgical techniques are the treatment of choice for the control of upper digestive tract hemorrhages after schistosomotic portal hypertension. However, recurrent hemorrhaging due to gastroesophagic varices is frequent. OBJECTIVE To evaluate the outcome of treatment based on embolization of the left gastric vein to control the reoccurrence of hemorrhages caused by gastroesophagic varices in patients with schistosomiasis previously submitted to non-derivative surgery. METHODS Rates of reoccurrence of hemorrhages and the qualitative and quantitative reduction of gastroesophagic varices in patients undergoing transhepatic embolization of the left gastric vein between December 1999 and January 2009 were studied based on medical charts and follow-up reports. RESULTS Seven patients with a mean age of 39.3 years underwent percutaneous transhepatic embolization of the left gastric vein. The mean time between azigoportal disconnections employed in combination with splenectomy and the percutaneous approach was 8.4 ± 7.3 years, and the number of episodes of digestive hemorrhaging ranged from 1 to 7 years. No episodes of reoccurrence of hemorrhaging were found during a follow-up period which ranged from 6 months to 7 years. Endoscopic postembolization studies revealed reductions in gastroesophagic varices in all patients compared to preembolization endoscopy. CONCLUSIONS Percutaneous transhepatic embolization of the left gastric vein in patients with schistosomiasis previously submitted to surgery resulted in a decrease in gastroesophagic varices and was shown to be effective in controlling hemorrhage reoccurrence.

Remote ischemic preconditioning and tacrolimus in the fetal small bowel transplant in mice

PURPOSE: To evaluate the effect of remote ischemic preconditioning (IPC-R) in the fetal small bowel transplantation model. METHODS: Two groups were constituted: The Isogenic transplant (ISO, C57BL/6 mice, n=24) and the allogenic transplant (ALO, BALB/c mice, n=24). In each group, the animals were distributed with and without IPC-R. It was obtained the following subgroups: Tx, IPC-R, Fk, IPC-Fk, in both strains. Intestinal grafts were stained with hematoxylin and eosin and immunohistochemically. RESULTS: The graft development evaluation in ISO group showed that IPC-R reduced the development compared with ISO-Tx (5.2±0.4 vs 9.0±0.8) and IPC-R-Fk increased the graft development compared with IPC-R (11.2±0.7 and 10.2±0.8). In ALO group, IPC-Fk increased the development compared with ALO-Tx and ALO with IPC-R (6.0±0.8, 9.0±1.2, 0.0±0.0, 0.5±0.3). The PCNA expression was increased in ISO group treated with Fk and IPC-R compared to other groups (12.2±0.8 vs Tx: 8.8±0.9, IPC-R: 8.0±0.4 and Fk: 9.0±0.6). The graft rejection was lower in groups treated with IPC-R (-18%), Fk (-68%) or both (-61%) compared with ALO-Tx. CONCLUSION: Remote ischemic preconditioning showed benefic effect even associate with Tacrolimus on the development and acute rejection of the fetal small bowel graft in the Isogenic and Allogenic transplants.