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Biomedical subjects

B Sevin

Publications and source records attributed to B Sevin.

12 recordsLinked to original sources
PubMed2004

Cardioprotection with resveratrol pretreatment: improved beneficial effects over standard treatment in rat hearts after global ischemia.

OBJECTIVE: The major objective of the present study is to evaluate the potential role of resveratrol (RVT), a natural antioxidant found in grapes and red wine, in protecting the myocardium from the deleterious effects of ischemia-reperfusion (I/R) injury using isolated rat hearts. METHODS: Langendorff perfused isolated rat hearts were subjected to 60 min of global ischemia following 60 min of reperfusion. RVT was given according to chronic pretreatment and/or acute treatment protocols. Animals received RVT at the dose of 20 mg/kg via an intragastric tube for 14 days before the experiment and/or at the infusion concentration of 10 microM for 30 min before the onset of ischemia. The myocardial postischemic recovery was compared using hemodynamic data (peak systolic pressure, end diastolic pressure, and +dP/dtmax), coronary flow, biochemical parameters (LDH, CK-MB, cTnI, myoglobin) from coronary effluent, and oxidative stress markers (MDA, GSH, carbonyl) from heart tissue homogenates in each group. RESULTS: RVT pretreatment and treatment protocols have provided increased preservation in myocardial recovery following global ischemia compared to a non-treated group. Furthermore, the ischemic damage of myocardium was significantly lower in chronic pretreated rats than in the acutely treated group. In contrast, no significant difference was observed in cardioprotective effects of RVT between the only pretreated group, and both the pretreated and treated group throughout reperfusion. CONCLUSION: The findings from this study indicate that RVT has potent cardioprotective properties against I/R injury in rat hearts. The study also highlighted that the administration of RVT, as pretreatment, has amplified the beneficial effects over the standard treatment.

Analysis of Variance↗
PubMed1999

The effects of methylprednisolone on complement, immunoglobulins and pulmonary neutrophil sequestration during cardiopulmonary bypass.

In this study, the authors administered high dose (30 mg/kg body weight i.v.) methylprednisolone before cardiopulmonary bypass to observe the effects on complement, immunoglobulins and pulmonary neutrophil sequestration. Fifty patients undergoing valve replacements were included in this study. Patients were divided into two groups: group I (20 patients) served as control and did not receive methylprednisolone, group II (30 patients) received methylprednisolone. Blood samples for complements (C3c and C4) were taken, before cardiopulmonary bypass, at 5, 10 and 30 min intervals from the end of cardiopulmonary bypass, after reversal of heparin with protamine infusion, and after skin closure. Blood samples for immunoglobulins were taken before cardiopulmonary bypass, 30 min after onset of cardiopulmonary bypass and after skin closure. After onset of cardiopulmonary bypass, all C3c and C4 levels decreased in both groups. There was a significant decrease in C4 levels at end of cardiopulmonary bypass and after protamine infusion in group I compared with group II (P < 0.05). C3c levels in group I decreased significantly compared with group II after 30 min of cardiopulmonary bypass and after protamine infusion (P < 0.05). All immunoglobulin (IgG, IgM, IgA) levels were decreased in both groups, but the decrease in IgG was statistically significant after skin closure in group I compared with group II (P < 0.05). Pulmonary neutrophil sequestration was higher in the control group compared with the methyl-prednisolone group (P < 0.05). In conclusion, methylprednisolone administration before cardiopulmonary bypass may prevent the harmful effects of complement activation, immunoglobulin denaturation and neutrophil sequestration in the pulmonary capillary system.

Adult↗
PubMed1999

Changes of antioxidant enzyme activities during cardiopulmonary bypass.

BACKGROUND: Reperfusion of ischemic heart causes the generation of free radicals, and these radicals play an important role in post-ischemic tissue damage. These free radicals are removed by scavenger enzymes and antioxidants in the cell. In this study, erythrocyte catalase, glutathione peroxidase and glutathione reductase enzyme activities were determined in patients undergoing cardiopulmonary bypass. METHODS EXPERIMENTAL DESIGN: Blood samples were obtained from the coronary sinus of patients at the following times: 1) Before cardiopulmonary bypass, 2) Immediately after cardiopulmonary bypass, 3) Fifteen minutes after the second specimen, 4) Thirty minutes after the second specimen. PATIENTS: this study was carried out on eleven patients undergoing open heart operation. MEASURES: catalase, glutathione peroxidase and glutathione reductase enzyme activities were determined in these patients. RESULTS. Catalase activity was significantly decreased in the third and fourth groups as compared with the first group, which was also the control group (p<0.05). Glutathione reductase activity in the third group was significantly higher as compared with control group (p<0.001). However, there were no differences in glutathione peroxidase activity among control group and other three groups (p>0.05). CONCLUSIONS: Our results indicate that the activities of antioxidant enzyme activities in erythrocytes are changed during the ischemia and reperfusion of the heart.

Adolescent↗
PubMed1996

Effects of aprotinin on plasma levels of neutrophil elastase and postoperative blood loss in cardiac surgery.

This study evaluated the effects of aprotinin on plasma levels of elastase, platelet count, fibrinogen levels and postoperative bleeding. Thirty cardiac surgery patients were randomly chosen for this study. The protease inhibitor aprotinin was given in high doses to 20 patients before and during cardiopulmonary bypass; 10 patients served as the control group. Mean patient age and body weight was similar in both groups. There were no significant inter-group differences in the total cardiopulmonary bypass and cross-clamp times. Mean (s.e.m.) elastase levels were significantly raised in the control group (161.9(2.57) micrograms/l) compared with the treated group (148.2(3.29) micrograms/l) at 30 min of cardiopulmonary bypass (P < 0.01) and rose even further at the end of cardiopulmonary bypass, after protamine infusion, and 24 h postoperatively (P < 0.001). Platelet counts decreased more in the control group (P < 0.001). Serum fibrinogen levels were significantly lower in the controls during and just after cardiopulmonary bypass (P < 0.01). Postoperative blood loss was significantly less in the aprotinin-treated patients (315(25) ml) compared with the controls (589(154) ml) (P < 0.05). Aprotinin appears to inhibit elastase release and decrease postoperative blood loss.

Adult↗
PubMed1994

Oxygen free radicals in erythrocytes during open heart operation.

This study was performed to observe the effect of myocardial ischemia on the patients undergoing cardiopulmonary bypass (CPB) operation. For this aim, superoxide dismutase (SOD) activities, reduced glutathione (GSH) and lipid peroxide (LP) levels were determined in blood samples which were obtained from the coronary sinus. Sampling times were as follows: (1) Before CPB. (2) Immediately after CPB. (3) Fifteen minutes after the second specimen. (4) Thirty minutes after the second specimen. SOD activities of these groups were 5135.10 +/- 278.51 U/g Hb, 3505.64 +/- 302.09 U/g Hb, 4206.55 +/- 272.25 U/g Hb, 4707.20 +/- 270.91 U/g Hb respectively. Also the LP levels were 1.90 +/- 0.29 nmol MDA/ml, 4.37 +/- 0.52 nmol MDA/ml, 4.09 +/- 0.39 nmol MDA/ml, 2.74 +/- 0.30 nmol MDA/ml respectively. GSH levels were slightly increased during ischemia and reperfusion; 103.27 +/- 5.18 mg/dl, 125.00 +/- 10.36 mg/dl, 125.00 +/- 6.61 mg/dl, 111.18 +/- 8.22 mg/dl respectively. SOD activities were reduced significantly in second group (p < 0.001), in third and fourth groups (p < 0.01) as compared with control group. Also LP levels were increased significantly in all groups (p < 0.001) as compared with controls. Our results confirm the generation of oxygen free radicals from ischemia and reperfusion of heart during CPB. Also it appears that oxygen free radical generation exceeds the capacity of intracellular SOD, which is the most important scavenger of free radical in the cell.

Adolescent↗
PubMed1993

Psychoneuroimmunological aspects of disease progression among women with human papillomavirus-associated cervical dysplasia and human immunodeficiency virus type 1 co-infection.

OBJECTIVE: Psychosocial associations have been observed with level of cervical dysplasia or "pre-cancer" and invasive cervical cancer [related to human papillomavirus (HPV) infection]. Psychoneuroimmunological relationships have been observed in human immunodeficiency virus type 1 (HIV-1) infection, which is being described in an increasing number of women. Our objective was to review these relationships regarding effects that might be expected in HIV-1 and HPV co-infected women. METHOD: This review was based on a Medline literature search supplemented by a manual search of selected journals unrepresented in that database. RESULTS: Relationships of psychosocial factors and level of cervical dysplasia were similarly observed with reference to immunological and health status in asymptomatic and early symptomatic HIV-1 infected homosexual men, suggesting that a potentiating effect may occur in HIV-1 and HPV co-infected women. Consistency of relationships across studies appeared to be enhanced by the use of a biopsychosocial model integrating the effects of life stressors, social support and coping style as well as psychiatric disorders. CONCLUSIONS: Research is indicated on the relationships between psychosocial factors, immunological status and clinical health status in this group of women. Because of the high prevalence of psychosocial risk factors for chronic psychological distress in these women and the known immunological and health status decrements occurring with progression of these two infections, a clinical screening program based on the biopsychosocial model is recommended as a means of secondary prevention. If effective in generating treatment referrals, such a program would likely improve quality of life and could aid in the determination of relationships with immunological and health status as well.

Acquired Immunodeficiency Syndrome↗
PubMed1989

A prospective surgical pathological study of stage I squamous carcinoma of the cervix: a Gynecologic Oncology Group Study.

Thirty-three institutions collaborating in the Gynecologic Oncology Group gathered surgical and pathological data on 1125 patients with primary, previously untreated, histologically confirmed stage I cervical carcinoma with more than 3 mm of invasion who were selected to undergo radical hysterectomy and paraaortic and pelvic lymphadenectomy. Of the 940 eligible, evaluable patients, 732 had squamous carcinoma. Of the study group, 87 (12%) did not undergo radical hysterectomy because of gross disease beyond the uterus or microscopic aortic node involvement documented at exploratory laparotomy. Among the 645 patients undergoing pelvic and paraaortic lymphadenectomy and radical hysterectomy, five risk factors were significantly associated with microscopic pelvic lymph node metastasis: depth of invasion (P = 0.0001), parametrial involvement (P = 0.0001), capillary-lymphatic space invasion (P = 0.0001), tumor grade (P = 0.01), and gross versus occult primary tumor (P = 0.009). The factors identified as independent risk factors for pelvic lymph node metastasis by multivariate analysis were capillary-lymphatic space involvement (P less than 0.0001), depth of invasion (P less than 0.0001), parametrial involvement (P = 0.0005), and age (P = 0.02). The model was used to predict the chance of a patient having nodal metastasis for any combination of risk factors.

Adult↗
PubMed1988

Reconstructive techniques in gynecologic oncology: the use of human dura mater allografts.

Human dura mater has been utilized in various reconstructive procedures following radical pelvic surgery at the Division of Gynecologic Oncology, University of Miami School of Medicine. Our preliminary results indicate that this allograft is strong, durable, and acts as a good biological barrier. However, it does not seem to prevent the development of enteropelvic fistulae in patients who undergo total pelvic exenteration following radiotherapy. Dura mater has also been employed in abdominal hernia repairs, repair of wound dehiscenses, and in the coverage of the femoral vessels after groin dissection. Provisional results with these reconstructive techniques appear promising. These results are discussed, and suggestions regarding the use of this allograft are delineated.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

The factors effecting complement activation in open heart surgery.

The activation of the complement system was investigated in 10 patients with rheumatic valve disease having heart surgery. The C3c, C4, leukocyte count and polymorphonuclear neutrophil count were determined in the blood samples taken before anaesthesia, after anaesthesia, 10 minutes after protamine administration and after the closure of the skin incision. In addition, atrial blood samples were taken after the release of the cross-clamp and pulmonary neutrophil trapping was investigated. In this study C3c and C4 consumption was found to take place after 30 minutes of CPB (cardiopulmonary bypass) and 10 minutes after protamine administration; the affects of anaesthesia and heparin were not significant.

Adult↗
PubMedDate not supplied

Human umbilical cord vein grafts for replacement of the superior vena cava.

We have used umbilical veins as experimental graft materials for superior vena cava replacement. The patency rate of these grafts in 25 laboratory animals was 96%; the mortality and graft thrombosis rate was 4%. Histopathologically, no evidence of rejection was detected in the graft material. These results suggest that umbilical veins are superior to other prosthetic materials as grafts in venous surgery.

Animals↗