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Biomedical subjects

I Celik

Publications and source records attributed to I Celik.

At least 109 records · Page 6Linked to original sources
PubMed1997

Serum angiotensin-converting enzyme and plasma atrial natriuretic peptide levels in hyperthyroid and hypothyroid rabbits.

BACKGROUND: It is known that serum angiotensin-converting enzyme (ACE), and plasma atrial natriuretic peptide (p-ANP) levels increase in hyperthyroidism. However, the precise mechanism of the effects of thyroid hormone on ANP release remains to be clarified. No study investigating serum ACE together with p-ANP levels has been performed in experimental hyperthyroid and hypothyroid rabbits. The present study was designed in order to provide additional evidence of increased ANP production and secretion in hyperthyroidism and to investigate the relationships between ANP, ACE and thyroid hormones. METHODS: Male New Zealand white rabbits (2.3-3.4 kg) were used throughout the study. Hyperthyroidism was induced by daily intraperitoneal administration of L-thyroxin (50 micrograms/100 g). Hypothyroidism was induced by daily intraperitoneal injection of propylthiouracil (2 mg/100 g body weight). Twelve days after the end of treatment, animals were sacrificed under anesthesia and blood samples were obtained from the aorta for serum ACE and thyroid hormone and p-ANP determinations. RESULTS: Serum ACE, plasma renin activity (PRA) and p-ANP were higher in hyperthyroid rabbits and lower in hypothyroid rabbits than in euthyroid rabbits. ANP concentration in atria was lower in hyperthyroid rabbits and higher in hypothyroid rabbits than in euthyroid rabbits. p-ANP, PRA and serum ACE levels were positively correlated with serum thyroxin levels. Inverse correlation was found between serum thyroxin and ANP concentration in atria (a-ANP), and between p-ANP and a-ANP. CONCLUSIONS: Our results indicate that not only p-ANP but also serum ACE activity was markedly increased in experimental hyperthyroid rabbits. It was thought that there were both direct and indirect effects of thyroxin on the release of ANP.

Animals↗
PubMed1996

The effect of prophylactic penicillin treatment on the course of arthritis episodes in patients with Behçet's disease. A randomized clinical trial.

OBJECTIVE: Because exposure to streptococcal antigens might be a major disease activity-provoking factor in Behçet's disease, this study was undertaken to evaluate the effectiveness of benzathine penicillin in the prophylaxis of recurrent arthritis episodes during the course of this disease. METHODS: A prospective, randomized study design was used to allocate patients to receive colchicine alone or colchicine plus benzathine penicillin for 24 months. RESULTS: The duration, severity, and pattern of arthritis episodes were found to be similar in the 2 treatment groups, but the number of arthritis episodes was significantly reduced, and the duration of episode-free time significantly prolonged, in the penicillin group compared with the colchicine-alone group. CONCLUSION: Penicillin treatment was demonstrated to offer adjunctive benefits in the prevention of arthritis episodes which are not obtainable with colchicine monotherapy. This finding could provide additional evidence for antigen triggering in the pathogenesis of Behçet's disease.

Adult↗
PubMed1996

Cytokines affecting megakaryocytopoiesis in rheumatoid arthritis with thrombocytosis.

Particular interleukins, namely interleukin (IL)-6, IL-4 and IL-1, with pro-inflammatory mediator activities have also been shown to be involved in the regulation of megakaryocytopoiesis. As rheumatoid arthritis (RA) is not uncommonly associated with reactive thrombocytosis, we investigated serum IL-1 alpha, IL-1 beta, IL-4 and IL-6 concentrations in RA patients with marked thrombocytosis, and compared them to the levels in RA patients with normal platelet counts and healthy volunteers. IL-1 beta. IL-4 and IL-6 concentrations were found to be correlated with the disease activity in both groups of RA patients, with higher serum levels of each cytokine in the thrombocythaemic group. Significant positive correlations of IL-1 beta and IL-4 with the platelet counts were documented only in patients with thrombocytosis. According to our results. IL-6 and IL-1 beta were found to be good indicators of disease activity in RA, while IL-1 beta and IL-4 seemed to be related more with the process of reactive thrombocytosis secondary to rheumatoid inflammation.

Adult↗
PubMed1996

Impaired haemostatic kinetics and endothelial function in Behçet's disease.

OBJECTIVES: This study was planned to explore the alterations of endothelial functions in the prethrombotic state of Behçet's disease (BD) patients. DESIGN: Plasma levels of endothelial secretory markers, in vivo molecular haemostatic and fibrinolytic parameters were cross-sectionally determined in the study group. SETTING AND SUBJECTS: In our tertiary referral centre, 30 (13 men, 17 women) BD patients, mean age 31 +/- 7 years, and 15 (eight men, seven women) healthy volunteers, mean age 26 +/- 9 years, were eligible for inclusion in the study after obtaining their written consents. INTERVENTIONS: All plasma samples for the assays of haemostatic parameters were obtained before and after an endothelial stimulant, desmopressin acetate (DDAVP). RESULTS: We have shown that in the procoagulant phase of BD patients: (1) basal thrombomodulin concentrations are increased and could not be provoked by DDAVP infusion; (2) both thromboxane B2 and 6-keto prostaglandin F1 alpha increments occur concurrently; (3) in vivo coagulation markers are elevated and raised plasmin-alpha 2 antiplasmin complex indicates a subclinical concomitant fibrinolysis; (4) the fibrinolytic process is conveyed in a somewhat complex manner in which plasminogen activator binding kinetics might be also altered. CONCLUSIONS: Endothelial cell injury, augmented thrombotic risk with compensatory excessive fibrinolysis and alterations in endothelial cell receptor-fibrinolytic marker relations might take place in the pathogenesis and thereby modulate the natural course of haemostatic processes of BD.

Adult↗
PubMed1996

Factors influencing the distribution of metastases and survival in metastatic breast carcinoma.

A total of 370 patients with metastatic breast, carcinoma who had been followed at Hacettepe Oncology Department between 1980 and 1991 were retrospectively analyzed for the factors influencing the distribution of metastases and survival. Median age was 47 years. Radical or modified radical mastectomies were performed in 199 (53.8%). Infiltrative ductal carcinoma was the most common pathologic subtype (69.4%). In 191 patients who were evaluated for estrogen receptor (ER) status, 101 (52.9%) were positive and 90 (47.1%) were negative. The distribution of first metastases did not differ between the soft tissue, bone, and visceral sites. The second, third, and fourth metastases were more common in visceral sites (p < 0.05). ER and menopausal status did not affect distribution. Mortality rate was significantly lower in the group having the first metastasis to the bone (p < 0.05). Of interest, first metastases were predominantly found in visceral sites in patients having radical or modified radical mastectomies (p < 0.05). Response to therapy, presence of initial metastases, axillary status, and age were the important factors influencing the overall survival in univariate analysis, whereas response to therapy, ER status, age, and presence of initial metastases were the important factors according to the multivariate analysis.

Adult↗
PubMed1996

Local fibrinolysis in native arteriovenous fistulas of haemodialysis patients.

This study was designed to evaluate local alterations of the fibrinolytic process in patent-functional native arteriovenous fistulas of patients on maintenance haemodialysis. For this aim, the concentrations of the main components of the fibrinolytic system were determined in plasma samples taken simultaneously from arteriovenous fistulas and contralateral upper extremity concurrent large veins of haemodialysis patients. Twelve patients (6 women and 6 men, age 36 +/- 8 years) with end-stage renal disease on maintenance haemodialysis and 15 non-smoker healthy volunteers (8 women and 7 men, age 31 +/- 10 years) with normal renal function were included in the study. The fibrinolytic parameters, except alpha 2-antiplasmin, were found to be elevated in arteriovenous fistulas of haemodialysis patients as compared with opposite upper extremity large veins of the same patients (p < 0.005). Increments in fibrinolytic parameters including tissue plasminogen activator antigen, urokinase-type plasminogen activator antigen and activity, and plasminogen activity together with lower alpha 2-antiplasmin levels favor activation of fibrinolysis, except for higher alpha 2-macroglobulin concentrations, in arteriovenous fistula. The study suggests that the fibrinolytic process is locally activated in arteriovenous fistulas of haemodialysis patients.

Adult↗
PubMed1996

Effect of prophylactic benzathine penicillin on mucocutaneous symptoms of Behçet's disease.

BACKGROUND: Recent studies point out a probable role of streptococcal antigens in the pathogenesis of Behçet's disease (BD). This has led to the proposal of benzathine penicillin as a therapeutic modality in BD. OBJECTIVE: A prospective study was conducted to compare the efficacy of colchicine and colchicine + benzathine penicillin treatments on mucocutaneous manifestations of BD. METHODS: 60 patients (group I) were given colchicine alone and 94 (group II) were given colchicine + benzathine penicillin. Frequency, number, duration and severity of oral aphthous ulcers, genital ulcers and erythema nodosum were determined before and after treatment. RESULTS: In group I, all parameters of oral ulcers and the frequency and healing time of genital ulcers and erythema nodosum decreased significantly. In group II, all parameters of oral aphthous ulcers, genital ulcers and erythema nodosum were significantly improved. When treatment results in the two groups were compared, the decrements in the frequency and duration of oral ulcers and erythema nodosum and the frequency of genital ulcers were significantly greater in group II than in group I (p < 0.05). CONCLUSION: We conclude that prophylactic benzathine penicillin combined with colchicine is more effective in controlling mucocutaneous manifestations of BD than colchicine alone.

Adult↗
PubMed1996

Ifosfamide, mesna and epirubicin as second-line chemotherapy in advanced breast cancer.

The ifosfamide, mesna and epirubicin (IMEpi) combination is administered to 16 patients having advanced metastatic breast carcinoma as second-line chemotherapy. We observed complete response in 6%, partial response in 44% (total overall response rate of 50%), stable disease in 12% and progressive disease in the remaining 38% of the patients. The median remission duration in responders was calculated to be 9.6 months. IMEpi regimen had a tolerable toxicity profile including alopecia, nausea and vomiting, microscopic hematuria, leukopenia and neurotoxicity in which serious complications necessitating discontinuation of the chemotherapy were not encountered. It might be concluded that IMEpi chemotherapy combination is an effective alternative among schedules in the management of patients with stage IV breast carcinoma without serious side effects.

Adult↗
PubMed1996

High-dose ifosfamide by infusion with Mesna in advanced refractory sarcomas.

Twenty patients with advanced sarcomas entered a pilot study with ifosfamide (IF) and mercaptoethane sulfonate sodium (Mesna) as a second-line treatment for six planned cycles. All patients had received prior doxorubicin- and cyclophosphamide-based chemotherapies. IF was administered at a dose of 3 g/m2 given as continuous intravenous infusion for 24 hr on day 1-5 with Mesna. In the absence of disease progression, chemotherapy was planned to be repeated every 4 weeks for six consecutive cycles. Following chemotherapy, only 2 patients (11%) achieved partial response with response durations of 6 and 9 months. There was no complete response. When considered for only high-grade tumors, the response rate reached up to 22%. Toxicity was reported for 48 cycles and the dose-limiting toxicities were myelosuppression (22%) and encephalopathy (17%). Chemotherapy protocol was changed after two or three courses in 16 patients with stable or progressive disease. IF/Mesna chemotherapy at this dose and schedule was not found to be very promising in refractory sarcomas as a second-line chemotherapy.

Adult↗
PubMed1996

Coagulation, fibrinolysis and fibrinolysis inhibitors in haemodialysis patients: contribution of arteriovenous fistula.

BACKGROUND: End-stage renal disease (ESRD) patients, not uncommonly, might exhibit thrombotic complications, as well as they may present with a bleeding diathesis. Changes in vessel wall and/or blood flow in native arteriovenous fistula (AVF) might also augment these disarrangements, as vascular endothelium is predominantly involved in the regulation of haemostatic pathways. OBJECTIVE: This study was designed to evaluate the state of coagulation and fibrinolysis and the role of AVF on haemostatic defects, in ESRD patients on maintenance haemodialysis. METHODS: Plasma samples for prothrombin fragment 1+2, thrombin-antithrombin III complex, plasmin-alpha2 antiplasmin complex, tissue type plasminogen activator antigen, urokinase type plasminogen activator antigen, u-PA activity, plasminogen activity, alpha2-antiplasmin and alpha2-macroglobulin assays were obtained from AVF and contralateral large veins of ESRD patients and from peripheral veins of the control group. RESULTS: Our results indicate a predominant thrombotic state as evidenced by activated coagulation markers and enhanced fibrinolysis in systemic circulation of ESRD patients. However the most novel finding is the probable contribution of AVF on haemostatic activation, as proven by the statistically different and positively correlated concentrations of both coagulation, fibrinolysis, and fibrinolysis inhibitors in AVF when compared to the levels in peripheral venous circulation. CONCLUSION: In addition to systemic derangements of haemostasis in ESRD patients, AVF individually might have a substantial role in the modulation of coagulation and fibrinolytic cascade.

Adult↗
PubMed1996

Cardiovascular adverse effects of antimicrobials in complex surgical cases.

Previously undescribed adverse effects of antibiotics on the cardiovascular system were described in complex surgical cases. Hypotension, bradycardia and tachycardia were seen in a randomised clinical trial, and confirmed in a randomised experiment with piglets, and in a study with isolated vascular tissue that was exposed simultaneously to antibiotics, endotoxin, and later on histamine at histamine H1-receptors. These findings may influence indications and duration for antimicrobial therapy, and support the concept of "minimal" postoperative antibiotic therapy in emergency abdominal operations.

Animals↗