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Biomedical subjects

A Bozkurt

Publications and source records attributed to A Bozkurt.

At least 73 records · Page 4Linked to original sources
PubMed1996

Effects of naloxone on beta-endorphin and cortisol release in sepsis.

We investigated the effects of the opiate antagonist naloxone on the release of beta-endorphin and cortisol in rats subjected to sepsis. Sepsis was induced in weanling male Wistar albino rats (3-4 weeks old, 75-90 g) by cecal ligation and double perforation (CLP). Forty animals were randomly allocated to four groups. Group 1 was given naloxone hydrochloride 0.5 mg/kg subcutaneously after CLP and this treatment was repeated at 2-h intervals until the rats were killed. Group 2 rats underwent a sham operation. Group 3 (control group) rats had CLP. Group 4 consisted of nonoperated animals used to establish normal reference values. Eighteen hours after CLP or sham operation, the rats were killed by cervical dislocation and a blood sample was drawn via cardiac puncture to determine the beta-endorphin and cortisol levels. The beta-endorphin levels were significantly higher in the control group than in the sham-operated, naloxone-treated (NT), and nonoperated rats (P < 0.05). However, there were no significant differences in plasma beta-endorphin levels between sham-operated, NT and nonoperated rats (P > 0.05). Plasma cortisol levels were significantly higher in the control group compared with the other three groups and this difference was more significant in sham-operated and nonoperated rats (P < 0.01). However, no difference existed between sham-operated, NT, and nonoperated rats (P > 0.05). This study demonstrates that the endogenous opioid system may play a role in the activation of the pituitary-adrenal axis following sepsis, and shows that the increase in beta-endorphin and cortisol could be blocked by naloxone.

Animals↗
PubMed1996

Giant bronchogenic cyst presenting as a lobar emphysema in a newborn.

Bronchogenic cysts are relatively uncommon congenital lesions. Because of the variability in clinical presentation and the shortcomings of diagnostic procedures, bronchogenic cysts present a diagnostic problem. This report describes a giant bronchogenic cyst that presented as a lobar emphysema in a newborn.

Bronchogenic Cyst↗
PubMed1996

Rapid liquid chromatographic assay of ciprofloxacin in human aqueous humor.

A simple, selective and sensitive method has been developed to determine ciprofloxacin in human aqueous humor. Separation of ciprofloxacin was carried out with pipemidic acid as internal standard using a Novapak C18 reversed-phase cartridge column (100 x 8 mm i.d., particle size 4 microns) and a mobile phase consisting of methanol-acetonitrile-citric acid (0.4 M) (3:1:10, v/v/v) at a flow rate of 1 ml min-1. The column effluent was monitored with fluorescence detection at 278 nm (excitation) and 450 nm (emission) after direct injection. The retention times were 4.88 min for pipemidic acid and 7.52 min for ciprofloxacin. The within-day and day-to-day reproducibilities were less than 7% for ciprofloxacin at 0.1 and 1 microgram ml-1 (n = 6). The mean recovery from aqueous humor was found to be 101.37 +/- 6.7% for ciprofloxacin at 0.1 micrograms ml-1 (n = 6 and the detection limit corresponding to a signal-to-noise ratio of 2.5:1 was 250 pg ml-1. The method was shown to be suitable for determining ciprofloxacin levels in human aqueous humor samples.

Aged↗
PubMed1996

Proguanil metabolism in relation to S-mephenytoin oxidation in a Turkish population.

The oxidation of proguanil was studied in 89 unrelated healthy Turkish volunteers after administration of proguanil (single dose, 200 mg, orally). Based on the distribution of the ratio of proguanil to cycloguanil excreted in urine, and using an antimode value of 15, the prevalence of poor metabolizers in a Turkish population was estimated to be 5.6% (95% confidence interval 2.0%-17.3%) which was similar to that in the other Caucasian populations. The relationship between the oxidative capacities of CYP2C19 for the two substrates, proguanil and mephenytoin, was studied in 39 subjects (two poor and 37 extensive metabolizers of proguanil). The two poor metabolizers of proguanil were also identified as poor metabolizers of S-mephenytoin and no misclassification by the two phenotyping methods was observed. The correlation between the metabolic ratio of proguanil to cycloguanil and the S/R-mephenytoin ratio as assessed by Spearman's rank test, was statistically significant (rs = 0.50, P < 0.001).

Adult↗
PubMed1996

Genitourinary tract injuries in girls.

OBJECTIVE: To evaluate lower genitourinary tract injuries in girls and to propose guidelines for the investigation and initial management of this unusual injury. PATIENTS AND METHODS: The hospital records of 38 girls (aged 2-13 years) treated in our institution because of lower genitourinary (LG) tract injury between 1988 and 1995 were reviewed retrospectively. Urethral ruptures were detected in six patients, but the most frequent injuries were to the vulva (63%) and vagina (53%). There were pelvic fractures in eight patients and femoral fractures in a further five. Eight patients had concomitant anorectal lacerations. Vaginal and perineal lacerations were repaired primarily and a temporary urethral catheter was placed for a mean of 3 days. Partial urethral disruptions were repaired primarily over a stenting catheter in three patients. In one case, vaginal laceration and proximal complete rupture of the urethra was managed through a transvaginal approach with end-to-end urethral anastomosis over a stenting catheter. There was a complete rupture of the distal urethra and avulsion of the external meatus in two cases and these patients were managed by urethral advancement and meatoplasty. RESULTS: Perineal physical signs did not reflect the severity of the lesions and cystovaginoscopy allowed localization of lacerations in some cases. Primary repair was possible in all cases. Three patients (8%) had wound infection after surgery. One patient had temporary urinary incontinence which was managed conservatively and one patient had faecal incontinence which needed secondary surgery. CONCLUSION: All female paediatric patients with suspected LG tract injury should undergo examination under anaesthesia to determine the degree of injury or possible concomitant injury to the urethra, bladder or rectum. Primary repair of these injuries is recommended.

Accidental Falls↗
PubMed1996

Penetration of topical 0.3% ciprofloxacin into human aqueous humor.

BACKGROUND AND OBJECTIVE: Investigation of the penetration of topical ciprofloxacin into aqueous humor. PATIENTS AND METHODS: Topical 0.3% ciprofloxacin drops were administered to 17 patients with cataracts before lens extraction surgery. The time interval between the first dose and sampling was 3 hours in 9 patients (group A) and 6 hours in 8 (group B). In both groups, aqueous samples were collected 30 minutes after the last ciprofloxacin application. Ciprofloxacin concentration was determined by high-performance liquid chromatography-fluorescence detection. RESULTS: Mean aqueous concentration was 0.83+/-0.48 microgram/ml in group A and 2.42+/-1.42 micrograms/ml in group B. CONCLUSION: Topical 0.3% ciprofloxacin penetrates into the aqueous in a significant concentration.

Administration, Topical↗
PubMed1995

Evaluation of micronuclei in exfoliated urothelial cells and urinary thioether excretion of smokers.

Mutagens are present in large quantities in the urine of cigarette smokers, thus, their urothelial cells may represent a possible target for absorbed and excreted mutagens. Our aim is to validate the micronucleus (MN) test in exfoliated urothelial cells obtained from urine samples of cigarette smokers. The urinary thioether (UT) test is also carried out on the same individuals in order to find out whether there is any correlation between these two end-points. The mean (+/- SE) MN frequency and UT determination is 1.93 (+/- 0.11)% and 9.71 (+/- 1.61) mmol SH/mol creatinine for 23 smokers, and 0.66 (+/- 0.05)% and 4.20 (+/- 0.56) mmol SH/mol creatinine for 20 nonsmokers. Our results show a higher frequency of micronucleated cells (p < 0.001) and higher excretion of UTs (p < 0.05) in smokers as compared to nonsmokers. Concentrations of UTs and MN frequencies increased with tobacco consumption. The MN frequencies showed only a marginal increase, not significant (p > 0.05), after passive smoking compared to nonsmoking values. There was no significant correlation between MN frequencies and UTs, either in smokers (r = 0.164, p > 0.05) or in nonsmokers (r = -0.018, p > 0.05). Our data demonstrate tobacco-induced chromosome damage in bladder tissue consistent with increased risk of cancer at this site among smokers.

Adult↗
PubMed1994

Polymorphic debrisoquin metabolism in a Turkish population.

Debrisoquin hydroxylation polymorphism was studied in 326 unrelated healthy Turkish volunteers. Debrisoquin sulfate (10 mg) was administered to subjects, and debrisoquin and 4-hydroxydebrisoquin were determined in the 0- to 8-hour urine samples. Debrisoquin oxidation was polymorphic, with 11 subjects (3.37%; 95% confidence interval, 1.69% to 6.07%) phenotyped as poor metabolizers. The metabolic ratio between debrisoquin and 4-hydroxydebrisoquin in 8-hour urine samples ranged from 0.02 in extensive metabolizers to 263.8 in poor metabolizers. The proportion of poor metabolizers was found to be in the range observed in the other white populations studied.

Adolescent↗
PubMed1994

S-mephenytoin, sparteine and debrisoquine oxidation: genetic polymorphisms in a Turkish population.

A mephenytoin test was carried out in 106 unrelated healthy Turkish volunteers. Racemic mephenytoin was coadministered with either debrisoquine or sparteine. The S/R mephenytoin ratio ranged from < 0.1 to 0.73 in 105 subjects, accordingly phenotyped as extensive metabolisers. One subject had an S/R mephenytoin ratio of 1.02, showing that he was a poor metaboliser of mephenytoin (0.94%, confidence interval 0.25% and 13.65%). In 48 subjects, the metabolic ratios of debrisoquine and sparteine were correlated significantly (rs = 0.61, P < 0.001).

Adolescent↗
PubMed1993

Determination of debrisoquine and 4-hydroxydebrisoquine in urine by high-performance liquid chromatography with fluorescence detection after solid-phase extraction.

A simple, selective and sensitive method has been developed to determine debrisoquine and 4-hydroxydebrisoquine in human urine. Separation of the analytes was obtained using a mobile phase of 0.1 M sodium dihydrogen phosphate-acetonitrile (87:13, v/v) and a muBondapak C18 column. The column effluent was monitored with fluorescence detection at 210 nm (ex) and 290 nm (em). Rapid sample preparation was achieved by solid-phase extraction columns (Bond Elut CBA, 3 ml capacity) which provided excellent recovery values for both compounds. The cost per sample using this approach could be minimized by column regeneration and re-use. The within-day and the day-to-day reproducibilities were less than 7% for both components. The method was shown to be suitable for the study of the debrisoquine-sparteine type genetic polymorphism in man.

Acetonitriles↗
PubMed1993

Effect of chronic experimental diabetes on vascular smooth muscle function in dog femoral artery.

To understand the effects of diabetes on vascular smooth muscle function and the underlying mechanisms involved, we examined the responses to noradrenaline (NA), serotonin, KCl and acetylcholine in the femoral artery of mongrel dogs with chronic diabetes (3 months)-induced subtotal pancreatectomy. Isolated ring segments of diabetic dog femoral artery exhibited an increased response to serotonin, a decreased response to NA, an unchanged response to KCl and a decreased endothelium-dependent relaxation to acetylcholine as compared with controls. The sensitivity (pD2) of diabetic femoral artery rings to NA and serotonin was markedly diminished. These results suggest that changed responsiveness of arteries from diabetic animals to NA, serotonin and acetylcholine could be the reflection of an alteration in the contractile machinery or the results of a decrease in endothelium-derived relaxing factor release in diabetic blood vessels.

Animals↗
PubMed1990

N-acetylation phenotyping with sulphadimidine in a Turkish population.

The distribution of acetylator phenotypes was studied in 244 unrelated Turkish subjects. Sulphadimidine and its acetylated metabolite were measured in 6 h plasma and 0-6 h urine samples after an oral dose of 10 mg/kg. Subjects with 37.5% or less acetylsulphadimidine in plasma were regarded as slow acetylators and the others as rapid acetylators. The mean plasma concentration of acetylsulphadimidine was about 2.5-times lower in slow acetylators. Urinary excretion of total sulphadimidine (free + acetylated) was also significantly lower in slow acetylators compared to rapid acetylators. The frequency of slow acetylators was 60.7% in the population (95% confidence interval 54.3% to 66.8%). Sulphadimidine acetylation showed no variation due to sex, age, body weight or pre-existing disease.

Acetylation↗
PubMed1990

Sulphamethoxazole acetylation in fast and slow acetylators.

Acetylation of sulphamethoxazole was studied in 22 subjects previously phenotyped with sulphadimidine. Sulphamethoxazole and its acetylated metabolite were measured in 6 h plasma and 0-6 h urine samples. Percentage of plasma acetylated-sulphamethoxazole did not correlate with the percentage of urinary acetylated-sulphamethoxazole. There was also no correlation between the percentage of acetylated-sulphadimidine and percentage of acetylated-sulphamethoxazole in plasma. The finding suggest that the acetylation of sulphamethoxazole has no predictive value in determining acetylator status.

Acetylation↗
PubMed1986

[Hemodialysis].

Explore the source record for details and available documents.

Humans↗
PubMed1983

The effects of sodium selenite on rat diaphragm muscle.

The effects of sodium selenite on isolated rat diaphragm muscle were investigated. Sodium selenite (0.1-3.0 mM) caused a complete inhibition of twitch responses elicited by either direct or indirect stimulation and induced a muscle contracture. These effects were irreversible and linearly related to the concentration of selenite and were not preceded by membrane depolarization. The contracture induced by sodium selenite is decreased by 50% in Ca++-free Ringer's solution containing 2.0 mM EDTA and the latency of muscle rigor was significantly reduced. The actions of selenite appeared to be temperature-dependent. Neither caffeine (20 mM) nor isotonic KCl solution produced any additional contracture after the completion of selenite rigor. Cysteine, tetrodotoxin, procaine and lidocaine failed to alter selenite-induced contracture. These results suggest that selenite probably caused an irreversible alteration in the contractile system of the mammalian muscle.

Animals↗
PubMedDate not supplied

Metabolic ratios of four probes of CYP2D6 in Turkish subjects: a cross-over study.

The relationships among the metabolic ratios for the standard probe drugs of CYP2D6 activity, such as debrisoquine, sparteine, metoprolol and dextromethorphan, were studied in 32 Turkish subjects. All subjects were randomly selected according to their phenotypes from a group of 111 Turkish subjects whose oxidation status had been tested for debrisoquine previously. All subjects were given a 10 mg debrisoquine tablet, a 100 mg sparteine tablet, a 100 mg. metoprolol tablet and a 20 mg dextromethorphan capsule orally with a wash-out period of at least 1 week between each probe administration. Metabolic ratios were calculated as percentage of dose excreted as parent drug/percentage of dose excreted as its hydroxymetabolite of parent drug in 0-8 h urine. Three poor metabolisers (PM) of debrisoquine were identified. They were also PMs of the other test probes and no misclassification by the 4 phenotyping methods was observed. All six correlations among the metabolic ratios of the 4 probe drugs assessed by Spearman's rank test were highly significant (P < 0.001). The present findings indicate that the oxidative metabolism of debrisoquine, sparteine, metoprolol and dextromethorphan is catalysed by the same cytochrome P450 in the Turkish subjects.

Adult↗