Effect of preconditioning and postoperative hyperbaric oxygen therapy on colonic anastomosis healing with and without ischemia in rats

Abstract Purpose To investigate the effect of hyperbaric oxygen therapy on colonic anastomosis healing with and without ischemia in rats. Methods Forty female rats underwent segmental resection of 1 cm of the left colon followed by end-to-end anastomosis. They were randomly assigned to four groups (n=10 each), a sham group; two groups were submitted to Hyperbaric Oxygen therapy (HBOT) with and without induced ischemia and the induced ischemia group without HBOT. The HBOT protocol evaluated was 100% O2 at 2.4 Atmosphere absolute pressure (ATA) for 60 minutes, two sessions before as a preconditioning protocol and three sessions after the operation. Clinical course and mortality were monitored during all experiment and on the day of euthanasia on the fourth day after laparotomy. Macroscopic appearance of the abdominal cavity were assessed and samples for breaking strength of the anastomosis and histopathological parameters were collected. Results There was no statistically significant difference in mortality or anastomosis leak between the four experimental groups. Anastomosis breaking strength was similar across groups. Conclusion The HBOT protocol tested herein at 2.4 ATA did not affect histopathological and biomechanical parameters of colonic anastomotic healing, neither the clinical outcomes death and anastomosis leak on the fourth day after laparotomy.

Evaluation of Indigo carmine on hepatic ischemia and reperfusion injury

Abstract Purpose To evaluate the effects of treatment with Indigo Carmine (IC) on rat livers subjected to ischemia-reperfusion injury. Methods The animals were subdivided into 4 groups: 1.SHAM group(SH) - saline; 2.SHAM group with IC-2mg/Kg(SHIC); 3.IR group - rats submitted to ischemia and reperfusion with saline(IR); 4.IR group with IC-2mg/Kg(IRIC). The IR protocol consists of liver exposure and administration of drug or saline intravenously, followed by 60 minutes of ischemia and 15 of reperfusion. Liver samples were collected for biochemical analysis. Results State 3 of mitochondrial respiration showed a significant worsening of the IRIC group in relation to all others. State 4 showed a difference between IRIC and SHIC. The Respiratory Control Ratio showed statistical decrease in IR and IRIC versus Sham. The osmotic swelling showed significant difference between SHxIR; SHICxIRIC and SHxIRIC. There was a significant increase in ALT in the IRIC group in relation to all the others. Concerning the nitrate dosage, there was a decrease in the group treated with IC(IRxIRIC). There was no difference regarding the dosage of Malondialdehyde. Conclusion IC was not able to protect mitochondria from IR injury and proved to be a potentiating agent, acting in synergy with the IR injury promoting damage to the hepatocyte membranes.

Resultados do tratamento das oclusões arteriais agudas de membros em hospital universitário - estudo retrospectivo / Results of treatment of acute occlusions of limb arteries at a university hospital - retrospective study

Resumo Contexto As oclusões arteriais agudas (OAA) de membros vêm crescendo paralelemente com a longevidade da população. Objetivos O objetivo deste estudo foi avaliar fatores de risco, salvamento de membros e sobrevida dos pacientes com OAA tratados em instituição universitária. Métodos Este é um estudo coorte retrospectivo de pacientes consecutivos. Os desfechos incluíram: sucesso técnico, sintomas, comorbidades, categoria Rutherford, artérias acometidas, complicações pós-operatórias, taxa de salvamento de membros em 30 dias e óbitos. Resultados Avaliou-se 105 prontuários, havendo predomínio do sexo masculino (65,7%) e idade entre 46 a 91 anos. As etiologias identificadas foram trombóticas (54,3%), embólicas (35,2%) e indefinidas (10,5%). Cerca de dois terços apresentavam-se nas Categorias II e III de Rutherford. Os sintomas associados encontrados foram dor (97,1%), esfriamento (89,5%), palidez (64,7%), parestesias (44,7%), paralisias (30,5%), anestesias (21,9%), edema (21,9%) e cianose (15,2%); e as comorbidades associadas observadas foram hipertensão (65,0%), tabagismo (59,0%), arritmias (26,6%), dislipidemias (24,0%) e diabetes (23,8%). O segmento femoral superficial-poplíteo-distal foi o mais acometido (80%). A tromboembolectomia com cateter Fogarty foi realizada em 73,3% dos casos (81,0% nas embolias, 71,9% nas tromboses e 54,5% nos indefinidos), sendo isoladamente em 41 pacientes (39,05%), nos quais ocorreram 11 reoclusões, 20 amputações e 14 óbitos. A reoclusão arterial foi mais frequente nas tromboses (12,9%; p = 0,054). Até 30 dias após tratamento, o óbito total foi de 14,6% e a amputação maior foi de 19,8%, sendo menos frequente na Classe I Rutherford (p = 0,0179). Conclusão O tratamento da OAA feito prioritariamente por meio de tromboembolectomia com cateter Fogarty, isolado e/ou associado, proporcionou taxas de amputação e complicações compatíveis com as apresentadas na literatura e progressivamente menores nas categorias Rutherford menos avançadas.

Abstract Background Acute arterial occlusions (AAO) in limbs have been increasing in parallel with population longevity. Objective To assess risk factors, limb salvage rates, and survival of patients with AAO treated at a University Hospital. Methods Retrospective cohort study of consecutive patients. Outcomes included: patency, symptoms, comorbidities, Rutherford category, arteries occluded, postoperative complications, and 30-day limb salvage and mortality rates. Results Medical records were evaluated from 105 patients, predominantly males (65.7%), with ages ranging from 46 to 91 years. Etiology: thrombotic (54.3%), embolic (35.2%), and undefined (10.5%). About 2/3 of the patients were assessed as Rutherford category II or III. Associated symptoms: pain (97.1%), coldness (89.5%), pallor (64.7%), sensory loss (44.7%), paralysis (30.5%), anesthesia (21.9%), edema (21.9%), and cyanosis (15.2%). Associated comorbidities: hypertension (65.0%), smoking (59.0%), arrhythmias (26.6%), dyslipidemia (24.0%), and diabetes (23.8%). The distal superficial femoral-popliteal segment was the most affected (80%). Thromboembolectomy with a Fogarty catheter was performed in 73.3% of cases (81.0% of embolic cases, 71.9% of thrombotic cases, and 54.5% of cases with undefined etiology) and was the only treatment used in 41 cases (39.05%), among which there were 11 reocclusion, 20 amputations, and 14 deaths. Arterial reocclusion was more frequent in thrombosis cases (12.9%, p = 0.054). Within 30 days of treatment, total mortality was 14.6%, and 19.8% of cases underwent major amputation, which was less frequent among Rutherford Class I patients (p = 0.0179). Conclusion Treatment of AAO was primarily performed by thromboembolectomy with a Fogarty catheter, either alone or in combination with other treatments, achieving amputation and complication rates compatible with the best results in the literature and were progressively lower in less advanced Rutherford categories.

Cirugía de hombro en posición silla de playa: estrategias y recomendaciones para la prevención de complicaciones isquémicas / Strategies and recommendations for the prevention of ischemic complications in beach chair position for shoulder surgery

Beach chair position is require for Shoulder surgery frequently for proper resolution. The stroke associated with shoulder surgery is a rare complication and probably underreported. The objective of this article is to review the pathophysiology of the ischemic damage associated with beach chair position, learn about strategies and develop recommendations to minimize risks.

La cirugía de hombro (CH), requiere y requerirá colocar a los pacientes en la posición en silla de playa (PSP), cada vez con mayor frecuencia para su adecuada resolución. El asociado a CH, es una complicación poco frecuente y probablmente subreportada. El objetivo de esta revisión, es repasar la fisiopatología del daño isquémico asociado a PSP, conocer estrategias y elaborar recomedaciones destinadas a minimizar riesgos.

Beneficios perioperatorios por condicionamiento isquémico a distancia en la revascularización coronaria / Perioperative benefits of distant ischemic conditioning in coronary revascularization

Introducción: Una serie de breves periodos de isquemias a distancia pueden limitar el daño miocárdico producido por la isquemia/reperfusión. Objetivo: Analizar las diferencias entre los dos grupos (control y estudio) teniendo en cuanta el consumo de inotrópicos y/o vasopresores durante los períodos intra y posoperatorio, así como, incidencia de eventos adversos cardiacos mayores y mortalidad en el postoperatorio. Métodos: Se realizó un estudio cuasiexperimental, explicativo, comparativo con control histórico, en dos grupos de 247 pacientes, propuestos para revascularización coronaria. Se colocó un torniquete en el brazo derecho, en el grupo estudio, alternando 3 insuflaciones con 3 desinsuflaciones con una presión de 200 mmHg, manteniéndola 5 min cada una. Este proceder se realizó previo, durante y después del evento isquémico mayor, provocado por el pinzamiento de la arteria coronaria. Resultados: Se logró una disminución significativa del consumo de drogas inotrópicas y vasoactivas. Se comprobó además, la disminución en la incidencia de bajo gasto cardiaco reversible, fibrilación ventricular, nuevo infarto agudo de miocardio. Conclusiones: El condicionamiento isquémico a distancia es una importante herramienta a tener en cuenta para la protección cardiaca perioperatoria en la revascularización coronaria(AU)

Introduction: A series of brief distant ischemia periods can limit myocardial damage produced by ischemia or reperfusion. Objective: To analyze the differences between the two groups (control and study) taking into account the consumption of inotropics and/or vasopressors during the intraoperative and postoperative periods, as well as the incidence of major cardiac adverse events and mortality in the postoperative period. Methods: A quasiexperimental, explanatory and comparative study with historical control was conducted on two groups of 247 patients proposed for coronary revascularization. A tourniquet was placed to the right arm, in the study group, alternating three insufflations with three dessufflations with a pressure of 200 mmHg, keeping each for five minutes. This procedure was performed before, during and after the major ischemic event, caused by pinching of the coronary artery. Results: A significant decrease in the consumption of inotropic and vasoactive drugs was achieved. The decrease in the incidence of low reversible cardiac output, ventricular fibrillation, and new acute myocardial infarction was also proven. Conclusions: Distant ischemic conditioning is an important tool to be taken into account for perioperative cardiac protection in coronary revascularization(AU)

Effects of cyclosporine on ischemia-reperfusion injuries in rat kidneys. An experimental model

Abstract Purpose To assess Cyclosporine A (CsA) therapy at an intraperitoneal dose of 15 mg.kg -1 in a rodent model of non-septic renal ischemia. Methods Twenty male Wistar rats were randomized to receive CsA therapy or none therapy before undergoing 30 minutes of renal ischemia followed by reperfusion. Additionally, 10 rats were randomized to undergo the same surgical procedure of the aforementioned animals with neither ischemia nor CsA therapy. Twelve hours after kidney ischemia, the left kidneys were evaluated for histological injury according to Park's criteria. Serum creatinine (Cr), urea nitrogen (Ur) and sodium levels were obtained at different times of the experimental protocol. Results Rodents in the CsA group showed negative results (p<0.05) in serum variables (Cr: 0.41±0.05mg/dL vs . 4.17±1.25mg/dL; Ur: 40.90±3.98mg/dL vs . 187.70±22.93mg/dL) even the non CsA or control group (Cr: 0.35±0.07mg/dL vs . 3.80±1.20mg/dL; Ur: 40.10±4.70mg/dL vs . 184.50±49.80mg/dL). The negative results were also verified in histological evaluation, CsA group had 50% in the very severe grade of lesion, 10% in the severe and 40% in the moderate to severe whereas the control group had 90% in the very severe grade. Conclusion CsA was incapable of preventing the deleterious effects of ischemia-reperfusion injury in rat kidneys.

Effect of sevoflurane pretreatment in relieving liver ischemia/reperfusion-induced pulmonary and hepatic injury

Abstract Purpose To investigate the effect of sevoflurane preconditioning on ischemia/reperfusion (I/R)-induced pulmonary/hepatic injury Methods Fifty-one Wistar rats were randomly grouped into sham, I/R, and sevoflurane groups. After reperfusion, the structural change of the lung was measured by Smith score, the wet and dry weights (W/D) were determined, malondialdehyde (MDA) myeloperoxidase (MPO) content was determined colorimetrically and by fluorescence, respectively, and matrix metalloprotein-9 (MMP-9) mRNA was quantified by RT-PCR. Biopsy and morphological analyses were performed on liver tissue, activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were determined, and tumor necrosis factor-alpha (TNF-α) level was determined. Results The sham group showed no changes in tissue structure. Structural lesions in the sevoflurane and I/R groups were mild and severe, respectively. Smith score, W/D, MDA, MPO, and MMP mRNA showed the same trend, and were increased in the I/R group and recovered in the sevoflurane group, compared with the sham group (both P<0.05). AST and ALT were significantly increased compared to the sham group (AST: 655±52.06 vs . 29±9.30 U/L; ALT: 693±75.56 vs . 37±6.71 U/L; P<0.05). In the sevoflurane group, AST and ALT levels were significantly decreased (464±47.71 and 516±78.84 U/L; P<0.001). TNF-α presented similar results. Conclusion The protection of lung and liver by sevoflurane may be mediated by inhibited leukocyte recruitment and MMP-9 secretion.

Is the early or delayed remote ischemic preconditioning the more effective from a microcirculatory and histological point of view in a rat model of partial liver ischemia-reperfusion?

Abstract Purpose: To compare early- and late-effect remote ischemic preconditioning (RIPC) by analysing the microcirculatory, hemodynamic and histological changes in partial liver ischemia-reperfusion of rats. Methods: 60-minute partial liver ischemia followed by 120-minute reperfusion was performed without (Control group, n=7) or with preconditioning. In RIPC groups a tourniquet was applied around the left thigh using 3 cycles of 10-minute ischemia/10-minute reperfusion, one (RIPC-1, n=7) or twenty-four hours (RIPC-24, n=7) before I/R. Hemodynamic and microcirculatory measurements were performed before and after ischemia and in 30th, 60th and 120th minute of reperfusion and histological examination at the end of reperfusion. Results: Blood pressure decreased in all groups followed by biphasic changes in Control group. In RIPC groups R120 values returned almost to normal. Heart rate increased in Control and RIPC-1 groups at R120, while RIPC-24 did not show significant changes. Microcirculation of non-ischemic liver stayed constant in Control and showed significant changes in RIPC-24 group, while in ischemic liver elevated by R120 in all groups. RIPC didn't reduce histological alterations. Conclusion: Considering the survival and the results, both remote ischemic preconditioning protocols had beneficial effect in hepatic ischemia-reperfusion, however the histopathological findings were controversial.

The protective effect of Papaverine and Alprostadil in rat testes after ischemia and reperfusion injury

ABSTRACT Objective: To investigate the effect of papaverine and alprostadil on testicular torsion-detorsion injury in rats. Materials and Methods: A total of 40 male Wistar-Albino rats were used in this study. Four hours of right testicular torsion was applied to each group, excluding sham oper- ated group. The torsion-detorsion (T/D), T/D + papaverine and T/D + alprostadil groups received saline, papaverine and alprostadil at the same time as surgical detorsion, respectively. At 14 days after the surgical detorsion, ischaemic changes and the degree of damage were evaluated with Cosentino scoring and the Johnson tubular biopsy score (JTBS). Results: JTBS was determined as 8.8±2.7 in the Sham group, 5.08±1.9 in the T/D+papaverine group, 5.29±2.3 in the T/D +alprostadil group and 2.86±1.9 in the TD group. The JTBS was determined to be statistically significantly high in both the T/D + papaverine group and the T/D + alprostadil group compared to the T/D group (p=0.01, p=0.009). In the T/D + papaverine group, 3 (43%) testes were classified as Cosentino 2, 3 (43%) as Cosentino 3 and 1 (14%) as Cosentino 4. In the T/D +alprostadil group, 5 (50 %) testes were classified as Cosentino 2, 3 (30 %) as Cosentino 3 and 2 (20%) as Cosentino 4. Conclusion: The present study indicated that spermatic cord administration of alprostadil and papaverine showed a protective effect against ischemia/reperfusion injury after right-side testes torsion and histological changes were decreased after testicular ischemia reperfusion injury.

Acetaminophen mitigates myocardial injury induced by lower extremity ischemia-reperfusion in rat model

Abstract Objective: The injury-reducing effect of acetaminophen, an effective analgesic and antipyretic on ischemia-reperfusion continues to attract great attention. This study analyzed the protective effect of acetaminophen on myocardial injury induced by ischemia-reperfusion in an experimental animal model from lower extremity ischemia-reperfusion. Methods: Twenty-four Sprague-Dawley female rats were randomized into three groups (n=8) as (i) control group (only laparotomy), (ii) aortic ischemia-reperfusion group (60 min of ischemia and 120 min of reperfusion) and (iii) ischemia-reperfusion + acetaminophen group (15 mg/kg/h intravenous acetaminophen infusion starting 15 minutes before the end of the ischemic period and lasting till the end of the reperfusion period). Sternotomy was performed in all groups at the end of the reperfusion period and the heart was removed for histopathological examination. The removed hearts were histopathologically investigated for myocytolysis, polymorphonuclear leukocyte (PMNL) infiltration, myofibrillar edema and focal hemorrhage. Results: The results of histopathological examination showed that acetaminophen was detected to particularly diminish focal hemorrhage and myofibrillar edema in the ischemia-reperfusion + acetaminophen group (P<0.001, P=0.011), while there were no effects on myocytolysis and PMNL infiltration between the groups (P=1.000, P=0.124). Conclusion: Acetaminophen is considered to have cardioprotective effect in rats, by reducing myocardial injury induced by abdominal aortic ischemia-reperfusion.

Effect of ischemic postconditioning and atorvastatin in the prevention of remote lung reperfusion injury

Abstract Objective: The aim of the present study was to evaluate the ability of ischemic postconditioning, atorvastatin and both associated to prevent or minimize reperfusion injury in the lung of rats subjected to ischemia and reperfusion by abdominal aortic clamping. Methods: We used 41 Wistar norvegic rats, which were distributed into 5 groups: ischemia and reperfusion (I/R), ischemic postcondictioning (IPC), postconditioning + atorvastatin (IPC+A), atorvastatin (A) and SHAM. It was performed a medium laparotomy, dissection and isolation of the infra-renal abdominal aorta; except for the SHAM group, all the others were submitted to the aortic clamping for 70 minutes (ischemia) and posterior clamp removal (reperfusion, 70 minutes). In the IPC and IPC+A groups, postconditioning was performed between the ischemia and reperfusion phases by four cycles of reperfusion and ischemia lasting 30 seconds each. In the IPC+A and A groups, preceding the surgical procedure, administration of 3.4 mg/day of atorvastatin was performed for seven days by gavage. After the surgical procedure, the right caudal lobe was removed from the lung for histological study, using tissue injury score ranging from grade 1 (normal tissue) to grade 4 (intense lesion). Results: The mean lung injury was 3.6 in the I/R group, 1.6 in the IPC group, 1.2 in the IPC+A group, 1.2 in the A group, and 1 in the SHAM group (P<0.01). Conclusion: Ischemic postconditioning and atorvastatin were able to minimize lung reperfusion injury, alone or in combination.

Super-selective robot-assisted partial nephrectomy using near-infrared flurorescence versus early-unclamping of the renal artery: results of a prospective matched-pair analysis

ABSTRACT Introduction Super-selective clamping of tumor-specific segmental arteries was developed to eliminate ischemia of the remnant kidney while limiting hemorrhage during partial nephrectomy. The objective is to evaluate the benefice of super-selective clamping on renal functional outcome, compared to early-unclamping of the renal artery. Materials and Methods From March 2015 to July 2016, data from 30 patients undergoing super-selective robot-assisted PN (RAPN) for a solitary tumor by a single surgeon were prospectively collected. Tumor devascularization was assessed using indocyanine green near-infrared fluorescence. A matched-pair analysis with a retrospective cohort undergoing early-unclamping was conducted, adjusting on tumor complexity and preoperative eGFR. Perioperative, oncologic and functional outcomes using DMSA-renal scintigraphy were assessed. Multivariate analysis was performed to identify predictors of postoperative renal function and de novo chronic kidney disease (CKD). Results Super-selective RAPN was successful in 23/30 patients (76.7%), 5 requiring secondary main artery clamping due to persistent tumor fluorescence. Matched-pair analysis showed similar operating time, blood loss, positives margins and complication rates. Super-selective clamping was associated with an improved eGFR variation at discharge (p=0.002), 1-month (p=0.01) and 6-month post-op (-2%vs-16% p=0.001). It also led to a better relative function on scintigraphy (46%vs40% p=0.04) and homolateral eGFR (p=0.04), and fewer upstaging to CKD stage ≥3 (p=0.03). On multivariate analysis, super-selective clamping was a predictor of postoperative renal function. Conclusion Super-selective RAPN leads to an improved preservation of renal function and a reduced risk of de novo CKD stage≥3, while keeping the benefit of main artery clamping on perioperative outcomes.

The protective effect of dexmedetomidine in a rat ex vivo lung model of ischemia-reperfusion injury

Abstract Purpose: To investigate the effect of dexmedetomidine (Dex) in a rat ex vivo lung model of ischemia-reperfusion injury. Methods: An IL-2 ex vivo lung perfusion system was used to establish a rat ex vivo lung model of ischemia-reperfusion injury. Drugs were added to the perfusion solution for reperfusion. Lung injury was assessed by histopathological changes, airway pressure (Res), lung compliance (Compl), perfusion flow (Flow), pulmonary venous oxygen partial pressure (PaO2), and lung wet/dry (W/D) weight ratio. The levels of superoxide dismutase (SOD), malondialdehyde (MDA), 78 kDa glucose-regulated protein (GRP78) and CCAAT/enhancer-binding protein homologous protein (CHOP) were measured, respectively. Results: The introduction of Dex attenuated the post-ischemia-reperfusion lung damage and MDA level, improved lung histology, W/D ratio, lung injury scores and SOD activity. Decreased mRNA and protein levels of GRP78 and CHOP compared with the IR group were observed after Dex treatment. The effect of Dex was dosage-dependence and a high dose of Dex (10 nM) was shown to confer the strongest protective effect against lung damage (P<0.05). Yohimbine, an α2 receptor antagonist, significantly reversed the protective effect of Dex in lung tissues (P<0.05). Conclusion: Dex reduced ischemia-reperfusion injury in rat ex vivo lungs.

Perconditioning combined with postconditioning on kidney ischemia and reperfusion

Abstract Purpose: To evaluate if combination of perconditioning and postconditioning provides improved renal protection compared to perconditioning alone in a model of renal reperfusion injury. Methods: Thirty rats were assigned into 6 groups: normality; sham; ischemia and reperfusion; postconditioning; perconditioning; perconditioning + postconditioning. Animals were subjected to right nephrectomy and left renal ischemia for 30 minutes. Postconditioning consisted of 3 cycles of 5 min renal perfusion followed by 5 min of renal ischemia after major ischemic period. Perconditioning consisted of 3 cycles of 5 min hindlimb ischemia followed by 5 min of hindlimb perfusion contemporaneously to renal major ischemic period. After 24 hours, kidney was harvested and blood collected to measure urea and creatinine. Results: Perconditioning obtained better values for creatinine and urea level than only postconditioning (p<0.01); performing both techniques contemporaneously had no increased results (p>0.05). Regarding tissue structure, perconditioning was the only technique to protect the glomerulus and tubules (p<0.05), while postconditioning protected only the glomerulus (p<0.05). Combination of both techniques shows no effect on glomerulus or tubules (p>0.05). Conclusions: Perconditioning had promising results on ischemia and reperfusion induced kidney injury, enhanced kidney function and protected glomerulus and tubules. There was no additive protection when postconditioning and perconditioning were combined.

Effects of hypertonic saline solution associated to remote ischemic perconditioning in kidney ischemia/reperfusion injury in rats

Abstract Purpose: To evaluate the effects of hypertonic saline solution associated to remote ischemic perconditioning in renal ischemia/reperfusion injury in rats. Methods: Twenty five male rats (Wistar) underwent right nephrectomy and were distributed into five groups: Sham group (S); Ischemia/Reperfusion group (I/R) with 30 minutes of renal ischemia; Remote ischemic perconditioning group (Per) with three cycles of 10 minutes of I/R performed during kidney ischemia; Hypertonic saline solution group (HSS) treated with hypertonic saline solution (4ml/kg); remote ischemic perconditioning + Hypertonic saline solution group (Per+HSS) with both treatments. After reperfusion, blood samples were collected for BUN and creatinine serum levels analyzes. TBARS were evaluated in plasma and renal tissue to assess oxidative stress. Kidney histopathological examination were performed. Results: Per+HSS group showed a lower degree of renal dysfunction in relation to I/R group, whereas the technique of remote ischemic perconditioning isolated or associated with saline solution significantly reduced oxidative stress and histological damage. Conclusion: Remote ischemic perconditioning associated or not to saline solution promoted reduction of acute renal injury induced by ischemia/reperfusion.

Cyclosporine A attenuates apoptosis and necrosis after ischemia-reperfusion-induced renal injury in transiently hyperglycemic rats

Abstract Purpose: To investigate the effects of cyclosporine A on renal ischemia-reperfusion injury during transient hyperglycemia in rats. Methods: In a model of ischemia-reperfusion-induced renal injury and transiently induced hyperglycemia by intraperitoneal injection of glucose, 2.5 g.kg-1, Wistar rats were anesthetized with either isoflurane or propofol and received intravenous cyclosporine A, 5 mg.kg-1, five minutes before reperfusion. Comparison groups were isoflurane and propofol sham groups and isoflurane and propofol ischemia-reperfusion-induced renal injury. Renal tubular cell viability was quantitatively assessed by flow cytometry after cell culture and classified as early apoptosis, necrotic cells, and intact cells. Results: Early apoptosis was significantly higher in isoflurane and propofol anesthetized animals subjected to renal ischemia-reperfusion injury when compared to both cyclosporine A treated and sham groups. Necrosis percentage was significantly higher in propofol-anesthetized animals subjected to renal ischemia-reperfusion injury. The percentage of intact cells was lower in both, isoflurane and propofol anesthetized animals subjected to renal ischemia-reperfusion injury. Conclusion: In a model of ischemia-reperfusion-induced renal injury, cyclosporine A, 5 m.kg-1, administered five minutes before renal reperfusion in rats with acute-induced hyperglycemia under either isoflurano or propofol anesthesia, attenuated early apoptosis and preserved viability in renal tubular cells, regardless of the anesthetic used.

Influence of remote ischemic conditioning and tramadol hydrochloride on oxidative stress in kidney ischemia/reperfusion injury in rats

Abstract Purpose: To evaluate the effects of tramadol hydrochloride associated to remote ischemic perconditioning on oxidative stress. Methods: Twenty five male rats (Wistar) underwent right nephrectomy and were distributed into five groups: Sham group (S); Ischemia/Reperfusion group (I/R) with 30 minutes of renal ischemia; Remote ischemic perconditioning group (Per) with three cycles of 10 minutes of I/R performed during kidney ischemia; Tramadol group (T) treated with tramadol hydrochloride (40mg/kg); remote ischemic perconditioning + Tramadol group (Per+T) with both treatments. Oxidative stress was assessed after 24 hours of reperfusion. Results: Statistical differences were observed in MDA levels between I/R group with all groups (p<0.01), in addition there was difference between Tramadol with Sham, Per and Per+T groups (p<0.05), both in plasma and renal tissue. Conclusion: Remote ischemic perconditioning was more effective reducing renal ischemia-reperfusion injury than administration of tramadol or association of both treatments.

Experimental model for the study of retrograde flow / Modelo experimental para estudo da circulação retrógrada

BACKGROUND: Venous arterialization has been adopted as a strategy for salvage of limbs in critical ischemia without the distal arterial bed, with successful outcomes, but the mechanisms by which irrigation of the extremities takes place are still unknown. OBJECTIVES: To develop an experimental model to test hypotheses that could explain the mechanisms of blood supply in venous arterialization. METHODS: Eleven pigs underwent a period of hind limb ischemia followed by reperfusion achieved by venous arterialization, after interposition of conduits filled with 10 ml (5 animals - group 1) or 1 ml (6 animals - group 2) of China Ink. After euthanasia, the limbs were amputated and underwent histological analysis. RESULTS: Under optical microscopy, ink staining was observed in the arteriolar lumen of six (55%) of the eleven pigs used in the experiment; four (80%) out of five from group 1 and two (33%) out of six from group 2. CONCLUSIONS: The experimental model was capable of testing the hypothesis. The presence of China Ink in the arteriolar lumen shows that it is possible to supply the arterial vessels by means of venous arterialization.

CONTEXTO: A arterialização venosa tem sido adotada com bons resultados como estratégia para salvar membros em isquemia crítica sem leito arterial distal. No entanto, os mecanismos pelos quais a irrigação das extremidades ocorre permanecem desconhecidos. OBJETIVOS: Desenvolver um modelo experimental para testar hipóteses que podem explicar os mecanismos de nutrição em arterialização venosa. MÉTODOS: Onze porcos foram submetidos a um período de isquemia seguida de reperfusão do membro posterior, realizada por arterialização venosa, com interposição de condutos preenchidos com 10 mL (cinco animais - grupo 1) e 1 mL (seis animais - grupo 2) de tinta da China. Após a eutanásia, os membros foram amputados e submetidos a análise histológica. RESULTADOS: Na microscopia óptica, o pigmento foi encontrado no lúmen de arteríolas de seis (55%) dos 11 porcos utilizados no experimento; quatro (80%) de cinco animais eram do grupo 1 e dois (33%) de seis animais eram do grupo 2. CONCLUSÕES: O modelo experimental utilizado foi capaz de testar a hipótese. A presença de tinta da China no lúmen arteriolar mostra que é possível alcançar o vaso arterial por meio de arterialização venosa.

Análisis de impacto presupuestal de dabigatran, rivaroxaban y apixaban comparado con warfarina para prevención de fenómeno tromboembólico e isquémico en pacientes con fibrilación auricular no valvular en Colombia / Budget impact analysis of dabigatran, rivaroxaban and apixaban compared to warfarin for prevention of thromboembolic and ischemic phenomena in patients with non-valvular atrial fibrillation in Colombia

Tecnologías evaluadas: Dabigatran, rivaroxaban y apixaban, comparado con warfarina. Población: Pacientes adultos con fibrilación auricular no valvular en Colombia. Perspectiva: Tercer pagador - Sistema General de Seguridad Social en Salud. Horizonte temporal: El horizonte temporal de esta AIP en el caso base corresponde a un año. Adicionalmente se reportan las estimaciones del impacto presupuestal para los años 2 y 3, bajo el supuesto de inclusión en el POS en el año 1. Costos incluidos: Costos directos del tratamiento de acuerdo a las alternativas evaluadas y seguimiento a los pacientes. Fuente de costos: Los medicamentos fueron costeados con la información del SISMED, para costear los procedimientos se empleó tarifario ISS2001. Escenarios: Escenarios de aumento de participación en el mercado y de disminución de precios acorde a los resultados de la evaluación económica paralela a este AIP. Resultados: En el escenario 1, la inclusión implicaría una inversión de 479.616.207.902 en el año 1, de $ 112.930.049.925 en el año 2 y de $ 145.201.625.581 en el año 3, en el escenario 2 implicaría una inversión $ 212.829.453.5 en el año 1, $ 54.400.081.439 en el año 2 y $ 69.849.046.563 en el año 3.(AU)

Antioxidant effect of Legalon(r) SIL in ischemia-reperfusion injury of rat skeletal muscle

PURPOSE: To evaluated the potential antioxidant agent Legalon (r) SIL (silibinin-C-2',3-bis(hydrogensuccinat)) in the skeletal muscle of rats. METHODS: IRI was achieved via tourniquet application in Wistar-albino rats. Experimental groups were chosen as (i) sham control, (ii) IRI (3+2 h), (iii) IRI and Legalon (r) SIL-50 (50 mg/kg/i.p.), (iv) IRI and Legalon (r) SIL-100 (100 mg/kg/i.p.), and (v) IRI and Legalon (r) SIL-200 (200 mg/kg/ i.p.). Muscle viability (evaluated by triphenyltetrazolium chloride dye method), malondialdehyde, superoxide dismutase, catalase, and glutathione peroxidase were assessed in muscle samples using a spectrophotometer. RESULTS: Although viability of the injured limb non-significantly declined in the IRI group, administration of Legalon (r) SIL did not prevent injury. However, dramatic increase observed in malondialdehyde levels in the IRI group was prohibited by Legalon (r) SIL in a statistically significant manner. In comparison with the sham-control group, IRI and Legalon (r) SIL administration did not cause any significant alterations in the levels of superoxide dismutase, catalase, and glutathione peroxidase. CONCLUSION: Although Legalon (r) SIL was not sufficient to prevent muscle injury in terms of viability, it is found to be an effective option to reduce reactive oxygen species-induced cell injury.