Biomedical subjects

F Ayan

Publications and source records attributed to F Ayan.

12 recordsLinked to original sources

PubMed2003

Target organ damage and changes in arterial compliance in white coat hypertension. Is white coat innocent?

The aim of this study was to perform an extensive evaluation of target organ status, metabolic abnormalities and hemodynamic alterations in white coat hypertension (WCH). Fifty normotensive (NT), 90 WCH (ambulatory daytime blood pressure < 135/85 mmHg) and 101 hypertensive (HT) subjects underwent extensive biochemical, echocardiographic, fundoscopic examination. In a subgroup study, arterial compliance and intima-media thickness (IMT) were measured by Doppler ultrasound in left common carotid artery. WCH subjects were found to have higher body mass index (BMI) than the NTs (p = 0.042). Left ventricle mass index (LVMI) was greater in the WCHs than the NTs (p < 0.001), but significantly less than the HTs (p < 0.001). Hypertensive retinopathy was observed in the WCHs, but was less severe and rare compared to the HTs (13% vs 27%). Both WCHs and HTs had high levels of urinary albumin excretion (UAE) (p = not significant). Total cholesterol was higher in WCHs than in the NTs (p = 0.04) The distensibility coefficient (DC) of the WCHs was significantly greater than the HTs (p < 0.01), while significantly smaller than the NTs (p < 0.01). The compliance coefficient (CC) of the WCHs was significantly higher than the HTs (p < 0.01), and significantly less than the NTs (p < 0.01). The IMT in the HTs was significantly higher than the WCHs (0.81 +/- 0.05 vs 0.70 +/- 0.04 mm; p < 0.001) and the NTs (p < 0.001). The difference between the NTs and the WCHs was not significant. Our data indicate that patients with WCH represent an intermediate group between NTs and sustained HTs where target organ damage and cardiovascular risk is concerned.

Adult↗

PubMed2001

Biochemical evaluation of oxidative stress during exercise in patients with coronary heart disease.

The impact of exercise tolerance test on oxidative stress was assessed by thiobarbituric acid reactive substances and markers of antioxidant status, namely Cu Zn superoxide dismutase, glutathione peroxidase, glutathione and vitamin E in blood samples of patients with exertional angina. The study was aimed to differentiate patients with positive exercise test (coronary heart disease patients) from patients with negative exercise test, at rest and peak exercise with respect to the investigated variables. Significantly lower values for both glutathione peroxidase activity and glutathione level were observed in patients after exercise test (p<0.01 and p<0.05, respectively). Only the patients with positive exercise test had significantly lower values for Cu Zn superoxide dismutase, glutathione peroxidase and glutathione, and a significantly higher ratio of thiobarbituric acid reactive substances/glutathione after exercise, as compared to before (p<0.05, p<0.05, p<0.05, p<0.01, respectively). Our findings indicate that the exercise test applied to patients with exertional angina oxidatively stresses the erythrocytes to a greater extent in exercise test (+) patients than in exercise test (-) patients.

Adult↗

PubMed2001

Comparison of the first dose response of fosinopril and captopril in congestive heart failure: a randomized, double-blind, placebo controlled study.

The purpose of this study was to compare the safety and tolerability of recommended initial doses of fosinopril (FOS) with those of captopril (CAP), in diuretic-treated, salt depleted "high risk" patients with congestive heart failure. Thirty patients were randomized in a double blind fashion to receive a single dose of either FOS 10 mg, CAP 6.25 mg or placebo. CAP produced a significant early and brief fall in BP, while the first-dose hypotensive response with FOS did not differ significantly from placebo. Baseline plasma angiotensin converting enzyme (ACE) activity was similar in all groups. Only CAP showed an acute and significant fall in plasma ACE activity, whereas FOS and placebo did not change ACE activity. There was no correlation between mean arterial pressure or percentile change in mean arterial pressure and plasma ACE activity. Also no correlation was found between high or low ACE activity level and first dose hypotension. The practical importance of the results are: For patients with congestive heart failure. FOS and CAP have different effects on BP after the first dose, and this effect may be dependent on the plasma ACE activity level. FOS produces ACE inhibition and BP changes similar to placebo so it is the safer choice for the treatment of congestive heart failure.

Administration, Oral↗

PubMed1999

A method to evaluate microcirculatory vascular patency of full thickness burn in an animal model.

BACKGROUND: In cases of thermal injuries it is always difficult to predict the extent of necrosis to the peripheral ischemic zone. Practically, full-thickness skin burn also affects the underlying muscle, panniculus carnosus, which adheres tightly to the skin. In this proposed model, the muscle which was always partly damaged also covers the ischemic zone of full-thickness burn injury. To evaluate the deeper levels of injury, the status of the micro circulation of thermally affected muscle was evaluated by counting the accumulated radioactive agent, 99mTc methoxyisobutylisonitril (MIBI) in the muscle cells. METHODS: 370 MBq/kg (10 mCi/kg) MIBI was administered intravenously to the animals having burn injuries by a comb device as described in previous literature. Then, 20 minutes after injection, whole burned areas were excised and placed under a gamma camera. Each thermally injured area showed four rectangular defects with lower tracer uptakes than the three adjacent interspaces. The tracer uptake of the burned sites and interspaces was analyzed from the acquired images on a computer, and the degree of injury could be assessed quantitatively. Additionally, specimen counts were obtained from selected burned stripes, interspaces and normal tissue for comparison. RESULTS: Burned sites were evident with lower tracer uptakes whereas interspaces with higher uptakes. Captured activity in interspaces indicated that capillary patency mostly maintained and it permitted the arrival of the radiopharmaceutical to the muscle cells. CONCLUSIONS: Muscle layer, where just below the burn area and tightly attached to the skin, could be assessed as a representative of the extension of the injury.

Animals↗

PubMed1998

Involvement of neutrophils in ischemia-reperfusion injury of inguinal island skin flaps in rats.

Increased production of oxygen free radicals and infiltration of neutrophils into tissue subjected to ischemia-reperfusion have emphasized that neutrophils play a direct role in the development of injury. The present study was designed to elucidate the effect of FK506, a new immunosuppressive drug, on 11 hours of complete ischemia and reperfusion of the inguinal island skin flaps in rats. Group 1 (n = 10) control animals underwent ischemia and reperfusion and no treatment. Group 2 (n = 10) animals received FK 506 0.3 mg/kg/day, and group 3 (n = 9) animals received 0.5 mg/kg/day intramuscularly for 3 days before the ischemia. The effect of the drug was evaluated by measuring flap survival and tissue malondialdehyde content and myeloperoxidase activity and also by histopathologic examination of the skin specimens taken at the 1st and 24th hour after reperfusion. The survival of flaps controlled for 7 days was found to be significantly improved in group 2 (65.0 +/- 10.93 percent) and group 3 (93 +/- 6.25 percent) when compared with the control group (14 +/- 10.12 percent) (p < 0.04 and p < 0.0001). The tissue contents of malondialdehyde and activities of myeloperoxidase were significantly lower in groups 2 and 3 than in the control group. Three days of pretreatment with FK506 significantly reduced neutrophil infiltration in groups treated with either of the doses. These results showed that neutrophils play an important role in island flap survival associated with ischemia-reperfusion injury. Increased neutrophil infiltration was found related with increased levels of malondialdehyde and myeloperoxidase. Flap necrosis and the increase in malondialdehyde, myeloperoxidase, and neutrophil infiltration were improved by FK506 pretreatment, a neutrophil modulating agent.

Animals↗

PubMed1997

Effects of allopurinol, ibuprofen and cyclosporin A on local microcirculatory disturbance due to burn injuries.

This experiment was designed to study the reactions in the surrounding area of burn injury that may lead to further necrosis in 24 h. To prevent extension of burn size into the tissue adjacent to burn injury, it was attempted to reduce progressive microvascular damage by different drugs (ibuprofen, allopurinol or cyclosporin A (CyA)) in a rat model. The burn model consisted of a row of four 10 x 20 mm burn areas separated by three unburned 5 x 20 mm skin bridges (interspaces). To evaluate microcirculation and perfusion of panniculus carnosus muscle which is beneath the burned area of skin, the radioactive agent, technetium-99m methoxyisobutylisonitrile (99Tc01-MIBI) was used 24 h after the burn. Capillary permeability of injured tissue was assessed by the wet and dry weight technique. In all study groups, interspaces showed higher uptakes of 99Tc01-MIBI between 40 and 95 per cent, in comparison with burn sites in the first 24 h following burn. Among the treated rats better results were obtained by allopurinol and CyA treatment that commenced before burn than ibuprofen. Wet and dry ratios were found to be significantly lower in interspaces in rats pretreated with allopurinol and CyA. Results of this experiment showed that neutrophils and free radical-mediated injury may be involved in the pathogenesis of local response to thermal injury, and allopurinol and CyA have some effects to prevent progressive ischemia, capillary compromise and oedema.

Allopurinol↗

PubMed1996

Neutrophil-mediated injury in ischemic skin flaps: amelioration of ischemic injury by cyclosporine in the rat.

The role of neutrophils, their presence, and their degree of infiltration was examined in ischemic skin flaps. In a rat model, caudally based dorsal flaps were studied and neutrophils were manipulated by giving cyclosporine at two different doses (15 and 30 mg per kilogram), administrated either for 5 days as a pretreatment or 15 minutes before flap elevation. The presence of neutrophils and lymphocytes in both intravascular and extravascular space was assessed at 15, 30, and 60 minutes by skin biopsies, taken after elevation of the flap, by direct quantitative counting under the light microscope. The correlation between the counts and localization of the neutrophils, but not the lymphocytes, and the percentage of necrosis showed an early and definite role of neutrophils on skin flap survival during ischemic insult. Cyclosporine-treated flaps showed a 24% to 37% increase in viability when compared to control flaps. These data suggest that neutrophils, probably their interactions and/or products, play an important role in ischemic flap survival, and cyclosporine A is able to inhibit neutrophil accumulation and sequestration.

Animals↗

PubMed1995

[Fournier gangrene].

Fournier's gangrene is a relatively rare, mixed aerobic and anaerobic soft tissue infection in the perineoscrotal area. Although it is convenient to give it a separate name, it is really either necrotizing fasciitis or nonclostridial myonecrosis of the scrotal and perineal areas. The condition frequently develops from perineal diseases, including perianal abscess, and fistulas, inflamed haemorrhoids and indwelling urethral catheter. In patients with Fournier's gangrene morbidity is extreme and mortality high. This article is based on a retrospective study of 15 cases of Fournier's gangrene, 13 in male and 2 in female patients. A combination of surgery and antibiotics was used to treat 9 patients. The last 6 cases were treated with a combination of surgery, antibiotics and hyperbaric oxygen. In 13 cases, the diagnosis was made on the basis of the fulminating progression of the infection to a scrotal gangrene, identification of multiple underlying pathogenic organisms and toxaemia. In the 2 female patients, a similar infection developed in the labia majora and perineum and extended to the buttocks and the anterior abdominal wall.

Adult↗

PubMed1993

Early wound excision and skin grafting restores cellular immunity after severe burn trauma.

Suppression of cellular immunity following thermal injury may contribute to the high incidence of postburn sepsis. Early excision and skin grafting may remove deleterious local wound factors and prevent immunosuppression. The effect on cellular immunity of early burn wound excision and skin grafting was investigated in an animal model using female Wistar rats. The development of immunosuppression shortly after burn injury was shown by popliteal lymph node assay and a 2,4-dinitrofluorobenzene skin reaction test. Excision and skin grafting 2 days after burn trauma restored parameters to normal. Burned tissue suppresses cellular immunity; this effect is preventable by early excision and skin grafting.

Animals↗

PubMed1993

The use of FK506 and skin allografting for the treatment of severe burns in an animal model.

A 30% burn injury was found highly immunosuppressive in mice by means of two in vivo measurements of cell-mediated immunity, and this immunosuppression could be prevented by early excision and grafting. FK506, a new immunosuppressive agent, was given at different doses for 12 days after early excision and grafting following burn and all doses prolonged the acceptance time of allografts from 14 to 20 days. Allograft rejection was not seen when animals were on the drug. Higher doses prolonged the rejection more, even after the cessation of the drug, and they caused some degree of immunodepression. Immunosuppressive treatment with FK506 when used following burn injury affected cell-mediated immunity minimally to moderately when compared to burned control groups.

Animals↗

PubMed1993

An alternative treatment of massive burns: skin allografts and cyclosporin immunosuppression without severe additional depression of cell-mediated immunity in an animal model.

This study investigated the effects of early excision of eschar and grafting with cyclosporin immunosuppression on immunological changes following burn injury. The immunological status of the rat was studied using two in vivo measures following a (30 per cent TBSA) full skin thickness burn injury. Cyclosporin was found to be a powerful immunosuppressive agent in skin transplantation, and its risks, efficacy and possible side-effects after thermal injury have been investigated. This study demonstrated that a large burn was profoundly immunosuppressive, and early excision and grafting was able to restore cell-mediated immunity significantly as reflected by two in vivo assays. The short course of the immunosuppressive treatment to delay skin allograft rejection did not cause a severe additional effect on cell-mediated immunity after thermal injury. Allograft survival appeared to be related to immunosuppression caused mainly by cyclosporin treatment and also by the immunosuppressive effect of the burn.

Animals↗

PubMedDate not supplied

Intestinal perforation due to phytobezoar obstruction.

Phytobezoars are rare causes of acute abdomen cases. Here we are reporting two cases which were presented with acute abdomen symptoms and later were found to be small intestinal perforation due to bezoar.

Adult↗