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Biomedical subjects

M Cengiz

Publications and source records attributed to M Cengiz.

At least 19 recordsLinked to original sources
PubMed2006

Effect of ticlopidine in the prevention of radiation enteropathy.

Impairment of vascular function is considered to play an important role in chronic radiation enteropathy. In this experimental study, the role of ticlopidine, an inhibitor of ADP-induced platelet aggregation, was investigated in radiation enteropathy. 80 male Wistar albino rats, each weighing 170-200 g, were divided into four groups: (a) radiation alone (n = 20); (b) radiotherapy plus ticlopidine (n = 20); (c) ticlopidine control (n = 20) and (d) control (n = 20). Both radiation groups received 19 Gy radiation to the exteriorized intestinal segments in a single fraction. Ticlopidine or vehicle was administered 12 h after radiotherapy and continued for 1 month. Rats from every group were euthanized randomly at intervals of 6 weeks from 2 weeks to 26 weeks. Histopathological radiation injury was assessed using radiation injury scoring (RIS). Radiation with ticlopidine or radiation alone groups showed significant RIS deterioration compared with controls in all time points studied. Comparison of median RIS of radiotherapy and radiotherapy+ticlopidine groups at the 2nd, 14th and 26th weeks yielded statistically significant RIS in favour of radiotherapy+ticlopidine group (p = 0.05). However, these differences were less pronounced at the 8th and 20th week (p = 0.07). Both radiation groups had poor weight gain when compared with control and ticlopidine groups. The weight gain in radiotherapy+ticlopidine group was significantly superior to only radiation group between 10th and 20th weeks (p = 0.05). This study showed that inhibition of platelet aggregation with ticlopidine might be useful in radiation enteropathy. However, the precise role of antiaggregant therapies on radiation enteropathy should be comprehensively studied before clinical consideration.

Animals↗
PubMed2005

1,25-Dihydroxy vitamin D3: can it be an effective therapeutic option for aggressive fibromatosis.

Aggressive fibromatosis (AF), also known as desmoid tumor is a monoclonal fibroblastic proliferation in a collagen matrix that arises in musculoaponeurotic structures. Though considered as benign, they are locally invasive and their propensity for recurrence after conservative surgery is well documented. Addition of postoperative adjuvant radiotherapy produces higher local control rates, although recurrence rates are still high in patients with positive margins. The antineoplastic activity of vitamin D has been demonstrated both in vitro and in vivo models of several cancers. The proposed mechanisms for antineoplastic activity include inhibition of proliferation associated with cell cycle arrest, induction of apoptosis and reduction in invasiveness and angiogenesis. It has also been shown that vitamin D has a negative impact on collagen homeostasis by inhibiting the formation and increasing its degradation. Since vitamin D has an antineoplastic activity and negative effect on collagen synthesis and deposition, it is proposed that 1,25-dihydroxy vitamin D3 can be a right therapeutic option for the management of desmoid tumors.

Antineoplastic Agents↗
PubMed2005

Importance of timing of antiaggregant treatment in the prevention of radiation induced enteropathy.

Chronic radiation enteropathy (CRE) is an undesirable radiation-induced toxicity and a common health problem in patients with pelvic or abdominal malignancies. Damage to microvascular endothelial cells and connective tissue is blamed to cause this adverse effect. It is shown that platelets are the first cellular elements that initiate the homeostatic and inflammatory responses and release of several proinflammatory and fibrinogenic mediators. Antiplatelet agents such as ticlopidine and clopidogrel were shown to prevent CRE and this effect is believed to be directed by their activities against thrombocytes. However, recent studies have shown that these drugs also induce apoptosis in endothelial cells and may lead to decreased expression of endothelial prostacyclin and thrombomodulin (TM) and increased release of von Willebrand factor which are shown to be major contributors of coagulation process. Assuming that radiation induced apoptosis occur 6-10h after irradiation, we think that timing of these antiaggregant drugs with irradiation is important and a 6-10h interval between these may be beneficial to avoid this adverse interaction.

Apoptosis↗
PubMed2005

The comparison of two lower extremity block techniques combined with sciatic block: 3-in-1 femoral block vs. psoas compartment block.

The objective of this study was to compare clinical and postoperative analgesic effects of femoral or psoas compartment blocks in patients undergoing arthroscopies. Fifty patients were randomly assigned to one of the two groups. Either femoral (group F) or psoas compartment (group P) block was applied followed by sciatic nerve block. All nerve blocks were provided with a 15 ml of bupivacaine 0.5% + 10 ml of lignocaine (lidocaine) 2%. Systolic and diastolic blood pressure (SBP and DBP), heart rate, and pulse oxymetry (SpO2) were recorded. Quality of anaesthesia, time to first analgesic use, verbal pain scores (VPS), sensorial and motor blockade resolution times and side effects were also recorded. Quality of anaesthesia, complete sensory blockade of obturator and lateral cutaneous nerves were higher in the group P than in group F. However, complete motor blockade findings were similar in both groups. In the group P, VPS values measured at 10 and 15 min were lower than that of group F. These values decreased at 10 min and thereafter as to baseline values. VPS values of the group F declined at 20 min and following measurement times as to baseline values. Durations of motor and sensorial block, and time to first analgesic use were similar between two groups. Total analgesic consumption at first 24 h in group P was lower than those of group F. Regarding heart rates, SpO2, SBP and DBP values, no significant differences were found between the groups. Combined psoas-sciatic technique provided more comfortable intraoperative anaesthesia and better postoperative analgesia when compared with femoral-sciatic technique for arthroscopic procedures.

Adult↗
PubMed2005

Identification and molecular characterization of Streptococcus equi subsp. zooepidemicus isolated from camels (Camelus dromedarius) and camel milk in Kenya and Somalia.

Seventeen Streptococcus equi subsp. zooepidemicus strains isolated from camels and camel milk in Kenya and Somalia were identified by their cultural characteristics, by biochemical and serological reactions with the help of commercial identification systems and by molecular studies using a multiplex PCR. The isolates were further characterized by a PCR-mediated detection of size polymorphisms in the 16S-23S rDNA intergenic spacer region and the virulence gene szp and by amplification of the virulence gene cne. These molecular analysis are potentially useful in identifying and characterizing S. equi subsp. zooepidemicus strains of this origin and could possibly be valuable in epidemiological investigations.

Animals↗
PubMed2004

Effect of ephedrine on the onset time of succinylcholine.

BACKGROUND: The aim of this study was to evaluate the effect of ephedrine administered prior to induction of anaesthesia on the onset time of succinylcholine for endotracheal intubation. METHODS: Patients were randomly assigned to receive intravenously (i.v.) either 70 microg kg(-1) of ephedrine (Group I; n = 25) or saline (Group II; n = 25) 3 min before induction of anaesthesia. Induction of anaesthesia was provided with propofol 2 mg kg(-1) plus remifentanil 1 microg kg(-1). Onset time and duration of muscle fasciculation and onset time of succinylcholine were recorded. Intubation was attempted after establishment of 100% thumb relaxation and difficulties were recorded. Heart rate, pulse oxymetry (SpO2) and mean arterial pressure (MAP) were also recorded. RESULTS: The onset time of succinylcholine were significantly (P < 0.001) shorter in Group I (26 +/- 4 s), when compared with Group II (43 +/- 6 s). Patients in Group I were intubated at 49 +/- 7 s compared with 68 +/- 10 s in Group II. The score of intubation was similar in both groups. Duration of muscle fasciculation was longer in Group II. Heart rate and MAP increased significantly (P < 0.05) after ephedrine injection, compared with the baseline value in Group I. CONCLUSIONS: The onset time of succinylcholine can be shortened with ephedrine pretreatment.

Adolescent↗
PubMed2002

Antioxidant system in Down syndrome: a possible role in cataractogenesis.

Recent studies show a relationship between oxidants, antioxidants, and degenerative disease of aging like cataract formation. Focal lens cortical changes and cortical liquification have been reported in patients with Down syndrome (DS) over 14 years. There is evidence supporting the hypothesis that trisomy 21 patients have an increase in free radical reactions. These changes in antioxidant system may play a role in cataractogenesis in Down syndrome. We screened serum samples from 12 patients with DS and cataract: and 12 healthy age and sex-matched persons. We evaluated the antioxidant enzyme activities of superoxide dismutase (SOD), glutathione peroxidase (GSHPx), glutathione-S-transferase (GST) and reduced glutathione (GSH) in erythrocytes. SOD and GSHPx levels of patients with DS were significantly higher than the control group. No significant changes were observed in GST and GSH levels between the DS and control groups. These findings suggest impairment in antioxidant system, which may be a possible mechanism for early cataract formation in DS.

Aging↗
PubMed2001

Acute phase response during radiotherapy.

PURPOSE: The acute phase response is characterized by changes in the plasma concentrations of a number of liver-synthesized proteins, one of which is C-reactive protein (CRP). The existence of these changes in the plasma profile underlies the change in erythrocyte sedimentation rate (ESR). Acute phase response itself is an illness and may result from immunologic reactions and inflammatory processes. This study is designed to determine whether the CRP level and ESR increase during radiotherapy and whether their rise correlates with acute and late radiation morbidity. METHODS AND MATERIALS: Between April 1997 and October 1998, 51 patients with the diagnosis of endometrium and cervical cancer were treated with surgery and postoperative radiotherapy. Median age at the time of radiotherapy was 52 (range, 26-73) years. Thirty patients received pelvic radiotherapy, and 21 patients were treated by pelvic-paraaortic irradiation. A total dose of 50.4 Gy to the pelvis and 45 Gy to the paraaortic field were delivered in conventional fraction. Erythrocyte sedimentation rates and CRP levels were studied before, during, and at the end of radiotherapy. RESULTS: The mean ESR measurements before and after radiotherapy were 40 (8-100) and 52 (10-120), and mean CRP levels were 1.4 (0.12-9.8) and 2.7 (0.12-32.2), respectively. The statistical analysis yielded significant rise in ESR and CRP levels at the end of radiotherapy (p < 0.001). The increase was more prominent in patients who were irradiated through pelvic-paraaortic field than in patients with pelvic radiation (p = 0.005 and 0.028 respectively). CONCLUSION: Acute phase response was present during radiotherapy. Radiotherapy should be considered as a cause of increase in CRP level and ESR especially in clinical conditions where acute phase response is important.

Acute-Phase Reaction↗
PubMed2001

Malignancy in Behçet's disease: a report of 13 cases and a review of the literature.

Behçet's disease (BD) has rarely been reported in association with malignant diseases. In most cases the autoimmune nature of the disease itself or immunosuppressive drug use has been blamed for malignant transformation. We report 13 cases of BD concurrent with neoplastic disease as well as treatment-related morbidities in this particular patient group. Between 1986 and 1999, 400 patients were diagnosed as having BD in Hacettepe University Hospitals. Of these 13 patients, 3.25% developed malignant diseases within a median follow-up time of 9.8 years. Solid tumors were diagnosed in 10 patients and haematological or lymphoid malignancies in three. Surgery was performed in seven patients, whereas radiotherapy was applied in six and chemotherapy in eight. A literature review revealed 27 cases of BD associated with malignancies, mostly lymphoid or haematological. Ten of our cases were solid tumors, and to our knowledge most of these are the first reported cases of specific malignancies concurrent with BD. Treatment-related morbidities were wound infection as surgical morbidity in one patient (1/7) and radiotherapy-related morbidity in three (3/6) patients in a median follow-up time of 2 years. Solid tumors in addition to lymphoid and haematological malignancies are also seen during the course of BD. Radiation therapy may cause severe late toxicities in the presence of BD. Chemotherapy and surgery are fairly safe for the treatment of malignancies in BD patients.

Adult↗
PubMed2001

Changes in the antioxidant system in epileptic children receiving antiepileptic drugs: two-year prospective studies.

The aim of this study was to measure changes in the antioxidant systems of epileptic children who had been receiving either valproate or carbamazepine monotherapy for 2 years. For this purpose, levels of erythrocyte glutathione, glutathione peroxidase, superoxide dismutase, and serum lipid peroxidation in 25 healthy children and 27 children who had previously been diagnosed as having epilepsy but who had not, prior to the study, received antiepileptic drugs were tested. Of the 27 epileptic children, 14 were given valproate, and the remaining 13 were given carbamazepine; these tests were repeated in the 13th and 24th months of treatment. The results showed that, during valproate therapy, the lipid peroxidation levels of the epileptic children increased and the glutathione peroxidase levels decreased in comparison with those levels recorded in the control and pretreatment groups. In addition, the superoxide dismutase levels were found to be increased during the first year of valproate therapy when compared with those of the pretreatment group. However, during carbamazepine therapy, lipid peroxidation levels increased when compared with the control group only, not the pretreatment group. Furthermore, the results showed that during the second year of treatment, the superoxide dismutase levels of the children receiving carbamazapine monotherapy were found to be higher than those of both the control and pretreatment groups. From these results, it can be concluded that the antioxidant systems of the children who had been receiving valproate therapy during the 2 years were more significantly affected than those of the children who had been receiving carbamazepine.

Adolescent↗
PubMed2000

The effects of carbamazepine and valproic acid on the erythrocyte glutathione, glutathione peroxidase, superoxide dismutase and serum lipid peroxidation in epileptic children.

Some epileptic drugs may change antioxidant enzyme activities in humans and experimental animals. Recent studies suggest that membrane lipid peroxidation may be causally involved in some forms of epilepsy, and the differences are reported in free radical scavenging enzyme levels. GSHpX, SOD, GSH are important parameters of antioxidant defence mechanisms. This study was undertaken to evaluate the effects of valproic acid and carbamazepine (CBZ) therapy on erythrocyte glutathione (GSH), glutathione peroxidase (GSHpX), superoxide dismutase (SOD) and lipid peroxidation. During the treatment with VPA or CBZ, the erythrocyte GSHpX and GSH levels of epileptic children were significantly changed as compared to those of health control subjects. The mean levels of serum lipid peroxidation and erythrocyte superoxide dismutase were not statistically different from controls. The methods used for investigation of glutathione peroxidase, superoxide dismutase, glutathione and serum lipid peroxidation were all based on spectrophotometric measurement.

Adolescent↗
PubMed2000

Erythrocyte glutathione, glutathione peroxidase, superoxide dismutase and serum lipid peroxidation in epileptic children with valproate and carbamazepine monotherapy.

This prospective study was carried out to determine changes in the antioxidant system in epileptic children receiving long term antiepileptic drugs (AEDs). Levels of erythrocyte glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and serum lipid peroxidation were determined in 25 healthy children and 30 epileptic children who had not yet received AEDs. Sixteen patients were treated with valproic acid (VPA) and 14 with carbamazepine (CBZ); 13 months later these parameters were retested. The results showed that SOD and lipid peroxidation levels were increased but the GSH-Px levels were decreased in epileptic children on VPA therapy compared with the control group and the results before treatment. No significant differences of these parameters were found in epileptic children on CBZ therapy compared with the control group and the results before treatment, except that lipid peroxidation level was slightly higher in epileptic patients before treatment. We conclude that antioxidant systems in epileptic children on CBZ therapy are better regulated in comparison with epileptic children on VPA therapy.

Adolescent↗
PubMed1999

The effect of verapamil in the prevention of radiation-induced cataract.

PURPOSE: Cataract is an unavoidable complication when radiation therapy includes the lens, even in small doses. Alterations in the ion content of the lens were considered to play an essential role in cataract formation. In this experimental study, the effect of verapamil on ion concentrations within the irradiated lenses was investigated in rats. METHODS AND MATERIALS: Forty female Wistar albino rats, each weighing 180-250 g, were divided into three groups: (a) radiation treated (n = 10); (b) no treatment (n = 10); (c) or a combination of radiation and verapamil (n = 20). Both the radiation group and verapamil-treated group received 5 Gy radiation to the cranium in a single fraction, including the eyes, within the irradiation volume. All animals were sacrificed by bleeding, 7.5 weeks posttreatment. Calcium, sodium, and potassium levels were measured in blood and in lens homogenates. However, for technical reasons, magnesium levels could only be studied in lens homogenates. RESULTS: Potassium and sodium concentrations in lens homogenates did not differ in the control and radiation groups, but both were significantly lower in the verapamil-treated group (p = 0.001, p = 0.009, respectively). Calcium levels were higher in the radiation group and lower in the verapamil-treated group compared to the controls (p < 0.0001); magnesium levels did not differ (p = 0.37). CONCLUSION: Verapamil effectively decreased the lens calcium concentration, which is accepted as the key element in radiation cataractogenesis. It is therefore concluded that verapamil may reduce the risk of radiation-induced cataract formation.

Animals↗
PubMed1999

High-dose-rate mold brachytherapy of early gingival carcinoma: a clinical report.

Two elderly edentulous patients with the diagnosis of early stage cancer of the upper gingiva were treated by customized dental mold brachytherapy. Locoregional tumor control was achieved in both patients. One patient is alive without any evidence of disease 36 months after treatment, the other patient died of distant metastasis shortly after brachytherapy. Brachytherapy, being easy to apply with short treatment time and good acute tolerance, is a good choice and effective modality for the management of early stage gingival cancer, particularly in elderly patients.

Aged↗
PubMed1999

N-acetyl-beta-glucosaminidase and beta-galactosidase activity in children receiving antiepileptic drugs.

To evaluate renal tubular function in children receiving antiepileptic drugs the urinary activity of two lysosomal enzymes, N-acetyl-beta-glucosaminidase and beta-galactosidase, were measured. The enzyme levels were determined before the administration of antiepileptic drugs and 8 months after. Fourteen epileptic children received valproate, and 17 received carbamazepine. The urinary activity of these enzymes in 25 healthy control patients also was examined. Increased N-acetyl-beta-glucosaminidase activity was found in 50% of patients taking valproate and in 17.6% of patients taking carbamazepine. Increased beta-galactosidase activity was found in 28.5% of patients taking valproate and 11.7% of patients taking carbamazepine compared with the results before treatment. On the basis of these results, it is suggested that patients taking antiepileptic drugs, especially valproate, may demonstrate minor signs of tubular dysfunction. In those patients who use these drugs at increased dosage levels or for long periods, the possibility of tubular dysfunction may be increased, and these dysfunctions may manifest in clinical symptoms.

Acetylglucosaminidase↗
PubMed1999

Sucralfate in the prevention of radiation-induced oral mucositis.

Radiotherapy-induced mucositis decreases the quality of life by impairing eating, swallowing, and talking and by disturbing sleep. Mucositis may also predispose to local and systemic infections and may cause interruption of radiotherapy course. We studied the efficacy of sucralfate suspension in the prevention and management of oral mucositis and pain during radiotherapy in a double-blind, placebo-controlled, randomized, prospective trial. Twenty-eight patients with head and neck cancer were included in the study. The patients were randomized to use either sucralfate mouth washing (n = 18) or placebo washing (n = 10) during irradiation. Oral mucositis and symptoms were assessed by the same physician using Radiation Therapy Oncology Group Acute Radiation Morbidity Scoring criteria. All patients developed varying degrees of radiation-induced mucositis. Grade 4 mucositis was not encountered in any patient. One patient had grade 1, seven patients grade 2, and two patients grade 3 mucositis in placebo group. In sucralfate group, nine patients each had grade 1 and grade 2 with no grade 3 mucositis. Patients in the sucralfate group experienced significantly lower degree of mucositis than placebo group (p < 0.05). Sucralfate mouth washing is beneficial in decreasing the intensity of radiation-induced mucositis and oral discomfort. It is cheap, easy to administer with no serious side effect, and may be routinely used in patients receiving head and neck radiotherapy.

Double-Blind Method↗