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Biomedical subjects

N Cakir

Publications and source records attributed to N Cakir.

At least 19 recordsLinked to original sources
PubMed2005

The effects of rosiglitazone and metformin on insulin resistance and serum androgen levels in obese and lean patients with polycystic ovary syndrome.

AIM: The aim of this study was to assess the effects of metformin and rosiglitazone on insulin resistance and serum androgen levels in both obese and lean patients with polycystic ovary syndrome (PCOS). MATERIALS AND METHODS: Forty lean [body mass index (BMI) < 25 kg/m2] and 40 overweight and obese (BMI > 25 kg/m2) patients were included in the study. Waist and hip measurements, serum sex steroid levels, insulin response to 75-g oral glucose tolerance test, fasting insulin, fasting C-peptide levels and homeostasis model assessment of insulin resistance (HOMA-IR) were determined in all patients. The degree of hirsutism was determined by the Ferriman-Gallwey scoring system. Patients were divided into two groups, with 40 (20 overweight and obese; 20 non-obese) patients each. One group was treated with metformin (MET group) 850 mg bid while the other received rosiglitazone (ROSI group) 4 mg/day for 12 weeks. All measurements were repeated at the end of this period. RESULTS: After the 12-week treatment period, HOMA-IR, area under the curve of insulin, fasting insulin and C-peptide levels were observed to have be decreased significantly in all groups. The decrease in the parameters mentioned above was similar in the four groups. The serum levels of free testosterone, androstenedione and DHEA-S decreased in all groups, but the decrease was statistically significant only in the ROSI groups. Within the lean MET group one patient became pregnant and was hence excluded from the final data analysis. Menstruations became regular after metformin therapy in 41.6% of lean and 35.7% of obese patients who had menstrual disturbance prior to the study. Rosiglitazone therapy improved menstrual disturbance in 61.5 % of lean and 53.8% of obese patients. CONCLUSIONS: Our data showed that both metformin and rosiglitazone increased insulin sensitivity in obese patients with PCOS as expected, and in lean patients as well. Rosiglitazone seemed to be more effective in decreasing the androgen levels and in achieving slightly greater improvement in menstrual disturbance than metformin.

Adult↗
PubMed2005

Antibiotic-associated diarrhea in a Turkish outpatient population: investigation of 288 cases.

Oral antibiotics are often prescribed, especially for respiratory tract infections in the community. The widespread use of broad-spectrum antibiotics causes an increased incidence of antibiotic-associated diarrhea (AAD). Although AAD has been studied in hospitalized patients, there is little available information concerning the characteristics of AAD in outpatient populations. The aim of this study was to investigate the clinical and laboratory findings of adult patients with community-acquired AAD. Between June 1998 and December 2003, the clinical reports of 288 patients were retrospectively reviewed. We observed that the duration between the start of antibiotic treatment and onset of symptoms was 7 days in most of the patients (86%), and the mean time was 9+/-1.0 days. The diarrhea was self-limited in all cases and mean duration of symptoms was 3 (+/-1.0) days (1-7 days). The most common symptoms were abdominal discomfort and tenesmus (61.1%), while elevated WBC counts and fever were detected rarely. We were able to perform microbiologic investigations in only 88 patients because of the financial problems. Of the 88 stool specimens tested, none of them were positive for pathogenic bacterial growth or toxin A production.

Administration, Oral↗
PubMed2004

Effects of PPARgamma and PPARalpha agonists on serum leptin levels in diet-induced obese rats.

Leptin and peroxisome proliferator-activated receptors are two important adipose tissue factors involved in energy metabolism regulation. It has been shown that PPARgamma agonists decrease leptin levels. However, the effects of PPARalpha agonists on leptin have not been investigated much. The aim of this study was to compare the effects of a PPARgamma agonist rosiglitazone (RSG) and PPARalpha agonist gemfibrozil (G) on body weight and serum insulin and leptin levels in diet-induced obese rats. Male Wistar rats were divided into six groups according to diet and drug therapy. After four weeks, serum glucose, triglyceride, insulin and leptin levels were significantly decreased in the high-fat-fed and RSG-treated groups compared to the group fed a high-fat diet only (162 +/- 19 vs. 207 +/- 34 mg/dl, 58 +/- 20 vs. 112 +/- 23 mg/dl, 3.1 +/- 1.0 vs. 15.2 +/- 4.0 ng/ml, 1.6 +/- 0.5 vs. 3.6 +/- 1.6 ng/ml, respectively). However, these parameters were not statistically different in RSG animals treated with a standard diet compared to the standard diet group. The high fat+RSG group gained much more weight compared to high-fat and high-fat+G groups (p > 0.05). Additionally, serum glucose, insulin and leptin levels were significantly decreased in the high-fat-fed and G-treated group compared to high-fat group (149 +/- 19 vs. 207 +/- 34 mg/dl, 57 +/- 16 vs. 112 +/- 23 mg/dl, 4.3 +/- 2.1 vs. 15.2 +/- 4.0 ng/ml, 1.6 +/- 0.4 vs. 3.6 +/- 1.6 ng/ml, respectively). These results suggest that PPARalpha agonists may decrease serum glucose, insulin and leptin levels as PPARgamma agonists do in diet-induced obese rats.

Adipose Tissue↗
PubMed2003

Mitral valve vegetation and cerebral emboli in a primary antiphospholipid syndrome patient who had hepatitis C virus infection: report of a case and review of the literature.

We report the case of 36-year-old woman who came to us with a history of recurrent miscarriages and who was later diagnosed as having primary antiphospholipid syndrome (PAPS) and chronic hepatitis C virus (HCV) infection. The patient was referred to us with generalised seizures; cranial MRI revealed multiple embolic infarcts in both frontal lobes and a focal cortical infarct in the left frontoparietal lobe. Her echocardiography showed mitral valve vegetation and insufficiency. The patient was put on oral anticoagulant therapy and during her 8-month follow-up period no thrombotic events occurred. We report this case because it was the first in which PAPS, valvular disease, a cerebral embolic event and HCV infection were coexistent in the same patient. We also review other cases in which there was valvular vegetation and a cerebral ischaemic event associated with PAPS.

Adult↗
PubMed2002

Acute and chronic effects of different concentrations of free fatty acids on the insulin secreting function of islets.

INTRODUCTION: Lipotoxic effects of free fatty acids (FFAs) on insulin secreting function of islet beta-cells have been demonstrated in recent studies. This toxic effect is especially prominent on postprandial hypertriglyceridemic period. Hypertriglyceridemia and high FFAs levels are the most common metabolic disturbances seen in diabetes mellitus (DM), in particular in uncontrolled cases. AIM OF STUDY: To investigate acute and chronic effects of different concentrations of FFAs on insulin secreting function of pancreas islet beta-cells. MATERIAL AND METHOD: We determined the acute and chronic effects of FFAs on insulin secretion dynamics of isolated rat islets. The insulinotropic effects of four D-glucose concentrations (Nil, 5.6, 8.3 and 27.7 mM) were studied in freshly isolated and perifused islets in the presence of two different concentrations (250 micromol/l and 1,250 micromol/l) of three FFAs (palmitate, stearate and oleate) to determine the acute effects. Chronic effects were investigated similarly on islet cells incubated for 72 hours in the presence of nil, 250 micromol/l and 1,250 micromol/l concentrations of FFAs. RESULTS: There was only a slight increase in insulin secretion at both concentrations of FFAs in freshly isolated islets, and the recovery was complete with a slight decrease in pathologic FFA channel. However, after 72 hour incubation at physiological or higher concentrations of FFAs, insulin secretion was significantly lower, even in the presence of high levels of D-glucose when compared to either nil channel results, or results of the fresh samples. Insulin levels of recovery phase were slightly but significantly lower in physiological and pathologically high FFA conditions when compared to nil condition. In addition, first phase insulin release response was lost in these islets. CONCLUSION: FFAs slightly increased the insulin output of normal fresh pancreas beta-cells. However, chronic exposure to FFAs resulted in loss of first phase insulin release and blunted insulin secretion response to various levels of D-glucose stimulation.

Animals↗
PubMed2001

Assessment of DNA strand breakage by comet assay in diabetic patients and the role of antioxidant supplementation.

Diabetes patients often show increased production of reactive oxidative species (ROS) together with vascular complications. The presence of these ROS may lead to increased DNA damage in peripheral blood lymphocytes that may be revealed by the comet assay. To test whether DNA is damaged in diabetes, peripheral blood samples were taken from 30 control individuals and 63 diabetic patients (15 insulin dependent (IDDM) and 48 non-insulin dependent (NIDDM)) and the alkaline comet assay was used to evaluate background levels of DNA damage. Significant differences were detected between control and diabetic patients in terms of frequencies of damaged cells. The extend of DNA migration was greater in NIDDM patients by comparison with IDDM patients which might indicate that IDDM patients are handling more oxidative damage on a regular basis. Smoker individuals had higher frequencies of cells with migration by comparison with the non-smokers in both groups. Also, clear differences between patients on placebo and on Vitamin E supplementation for 12 weeks were observed on the basis of the extend of DNA migration during single cell gel electrophoresis.

Adult↗
PubMed1998

Transferable trimethoprim resistance in Shigella strains.

The susceptibility patterns of 35 Shigella isolates (16 S. flexneri, 14 S. dysenteriae and 5 S. sonnei) to trimethoprim (Tp) and various antibiotics including amoxycillin, amoxycillin-clavulanic acid, nalidixic acid, ciprofloxacin, ceftazidime and ceftriaxone, were investigated. Twenty-two (62.8%) strains were resistant to Tp with a minimal inhibitory concentration (MIC50) value of 512 mg/L. Only six isolates were amoxycillin resistant, to which clavulanic acid restored sensitivity in all of them. None of the isolates were resistant either to extended spectrum cephalosporins or to quinolones. Resistance to Tp was transferred from 7 of the 22 isolates (31.8%) to the recipient Escherichia coli K12. Tp MIC values of the transconjugants were 512 mg/L. In no strain could amoxycillin resistance be transferred. Our results indicate that as the prevalence of transferable Tp resistance in Shigella isolates in Izmir is substantially high, alternative antimicrobial agents should be considered for empirical antibiotic therapy.

Amoxicillin↗
PubMed1998

The Effect of Glibornuride on Plasma Atrial Natriuretic Factor Levels in Patients with Newly Diagnosed NIDDM.

The aim of this clinical trial was to study the participation of plasma atrial natriuretic factor (ANF) in the risk of developing diabetic nephropathy by increasing the intraglomerular pressure. The effect of glibornuride on the plasma ANF levels and natriuresis was estimated in 10 newly diagnosed NIDDM patients and 10 control subjects. At base line, plasma ANF levels (15.05+/-2.32 pg/ml and 11.13+/-0.85 pg/ml) and the urinary sodium and potassium excretion rates were similar in patients and control subjects, respectively. Similarly, intravenous saline infusion (2 mmol/kg/60 min) resulted in remarkable elevation of plasma ANF levels in patients and in controls (28.89+/-4.72 pg/ml and 20.18+/-2.48 pg/ml, respectively) and in increased urinary sodium and potassium excretion rates in both groups. In contrast, after a single dose of 50 mg glibornuride p.o. the saline infusion did not increase ANF levels (15.13+/-1.00 pg/ml), while natriuresis but not kaliuresis persisted. All tests were performed during euglycemic clamp. It was suggested that glibornuride, with its natriuretic effect through the ATP sensitive potassium channels on the apical membrane of the thick ascending limb of loop of Henle and cortical collecting duct cells might inhibit the elevation of plasma ANF levels in response to extracellular fluid volume expansion. Similarly, with its natriuretic effect, it protects the diabetic patients against possible sodium retention. This result is considered noteworthy, since the inhibition of plasma ANF elevation in early diabetes by glibornuride may prevent glomerular hypertension and subsequent development of nephropathy.

Journal Article↗
PubMed1998

A case of Costello syndrome with endocrine features.

The case of a 21-year-old woman with findings consistent with Costello syndrome (CS) is reported. Most previously reported cases of CS were in young children. In addition to the classic features, the patient had endocrine disturbances including secondary amenorrhea, goiter, and adrenal insufficiency. This last abnormality may be the cause of the hypoglycemic episodes seen in CS. Osteoporosis and anemia were additional features. This case provides new information on the endocrine features and prognosis of CS.

Abnormalities, Multiple↗
PubMed1997

The association of chronic urticaria and angioedema with autoimmune thyroiditis.

BACKGROUND: An increased frequency of autoimmune thyroiditis is seen in patients with chronic urticaria and angioedema (CUA) and it has been hypothesized that autoimmunity may be playing a role in the pathogenesis of CUA. The aim of this study was to learn the extent of autoimmune thyroid disease in a series of patients who presented with CUA. METHODS: Thyroid function tests and thyroid autoantibodies were measured by radioimmunoassay and immunoradiometric assay respectively in 94 CUA patients and 80 age- and sex-matched healthy volunteers. RESULTS: Eleven patients (11.7%) were found to have thyroglobulin antibodies (TGA) and nine patients (9.57%) thyroid microsomal (TMA) titers ranging from 150 to 1340.37 and from 165.73 to 8000 IU/mL respectively. Both antibodies were detected in three control cases (3.7%). The association was statistically significant (P < 0.01). Six of 11 patients had thyroid dysfunction and the other five cases were euthyroid. CONCLUSIONS: Our results justified the use of TMA and TGA for the early diagnosis of autoimmune thyroiditis in combination with CUA. The higher frequency of these antibodies in our patients, along with results from previously published data, suggest that this entity may reflect an autoimmune basis in some CUA patients. Thyroid function tests are not enough to rule out thyroid disease, and thyroid antibody tests should be carried out in all patients with CUA.

Adult↗
PubMed1997

Evaluation of the resistance induction in enteric flora in children caused by oral ampicillin plus sulbactam.

To evaluate the effect on bacterial resistance of a beta-lactamase inhibitor, resistance patterns of predominant bacteria in enteric flora were evaluated before and after a 7-day course of oral ampicillin (100 mg/kg/days, qid, in 16 patients) and ampicillin-sulbactam (50 mg/kg/day of ampicillin, bd, in 32 patients) therapy. Ampicillin and ampicillin-sulbactam MICs for Escherichia coli, the predominant bacteria in all cases, and resistance rates of E. coli species to both antibiotics were 51.20 +/- 13.80 mg/L, 87.5% and 4.84 +/- 2.11 mg/L, 21% before the treatment respectively. Post-treatment MICs and resistance rates were 106.51 +/- 14.05 mg/L, 100% and 15.89 +/- 5.76 mg/L, 37.5% respectively, indicating a significant increase in MICs of both antibiotics (P < 0.05), being more prominent in the case of ampicillin-sulbactam (about four-fold). We concluded that oral ampicillin-sulbactam could also decrease the susceptibility of the enteric flora to ampicillin.

Ampicillin↗
PubMed1997

Circulating levels of tumor necrosis factor soluble receptors in systemic lupus erythematosus are significantly higher than in other rheumatic diseases and correlate with disease activity.

OBJECTIVE: To investigate the difference in acute phase protein responses between patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and spondyloarthropathies (SpA). METHODS: Circulating levels of cytokines inducing the production of acute phase proteins such as interleukin (IL)-6, IL-1 beta, and tumor necrosis factor (TNF)-alpha, and of cytokine inhibitors such as TNF soluble receptors (TNF-sR55 and TNF-sR75) and IL-1 receptor antagonist (IL-1ra), were measured in 2 cohorts of patients. The first cohort included 52 patients with SLE and 22 with RA, and the second included 21 with SLE, 20 with RA, and 18 with SpA. An examination at the time of blood collection and the Systemic Lupus Activity Measure (SLAM) index were used to assess disease activity in patients with SLE. Serum levels of IL-6 were measured using a biological assay, and concentrations of IL-1 beta, TNF-alpha, TNF-sR55, TNF-sR75, and IL-1ra were assessed by immunoassays. RESULTS: Although C-reactive protein (CRP) levels were significantly lower in SLE than in RA or SpA, the concentrations of circulating IL-6 or TNF-alpha were higher in SLE. The most striking observation was that TNF-sR levels were significantly higher in SLE than in RA or SpA. The TNF-alpha: TNF-sR ratio was also significantly lower in SLE than in RA. TNF-sR55 and TNF-sR75 levels correlated with disease activity in SLE. CONCLUSION: The weak acute phase protein response in SLE may be explained by a decreased ratio between inducing cytokines and their inhibitors. In addition, TNF-sR may prove a useful biological marker for the followup of SLE, where acute phase protein response is generally low during disease exacerbations.

Acute-Phase Proteins↗
PubMed1996

Propylthiouracil-induced hepatic damage.

OBJECTIVE: To report a case of propylthiouracil-induced hepatic damage. CASE SUMMARY: A 64-year-old white woman with hyperthyroidism received propylthiouracil 250 mg/d for 1 year. She developed hepatitis after 1 year of therapy. Alcohol and drug abuse were ruled out and all serologic tests for hepatitis A, B, and C were negative. Cytomegalovirus and Epstein-Barr virus infection were also ruled out. Antinuclear antibody, antimitochondrial antibody, and antismooth muscle antibody were negative. The clinical picture was similar to that of viral hepatitis characterized by nausea, vomiting, and jaundice. Histologic examination of a liver biopsy specimen showed chronic active hepatitis. The patient developed cirrhosis during follow-up. DISCUSSION: Propylthiouracil is widely used in the treatment of hyperthyroidism. Despite its widespread use, there have been only a few reported cases of propylthiouracil-induced hepatotoxicity. The precise mechanism of the injury is unknown, although immunologic factors are suggested. CONCLUSIONS: Hepatic damage induced by propylthiouracil is a rare complication. However, the danger of permanent hepatic damage should be kept in mind. The best way of preventing propylthiouracil hepatotoxicity is careful screening of patients considered for treatment.

Antithyroid Agents↗
PubMed1994

Treatment of autonomous thyroid nodules: safety and efficacy of sonographically guided percutaneous injection of ethanol.

OBJECTIVE: We evaluated the efficacy of sonographically guided percutaneous injection of ethanol as an alternative to surgery and administration of radioiodine, which have a higher risk of complications, for treatment of autonomously functioning thyroid nodules that may develop hyperthyroidism. SUBJECTS AND METHODS: Sixteen patients between 23 and 67 years of age who had solitary autonomous thyroid nodules were included in the study. The nodules were detected and evaluated using physical examination, measurements of hormonal levels, sonography, and scintigraphy. Sonographically guided percutaneous injection of ethanol was repeated one to two times each week for a total of four to eight treatments. The amount of ethanol used was 0.5-9.0 ml per treatment, depending on the volume of the nodule. RESULTS: Patients were followed up for at least 18 months. Clinical evaluation, including laboratory tests, showed that the patients' signs and symptoms subsided and hormones returned to normal levels in all cases. Scintigrams showed that the normal thyroid tissue that was suppressed before treatment regained normal function. Sonograms showed that the volume of the nodules decreased in 13 of 16 cases. No early or late permanent complications associated with treatment were noted. CONCLUSION: Our results show that sonographically guided percutaneous injection of ethanol can be used as an alternative treatment of autonomous thyroid nodules with the aim of eliminating the possible risk factors of surgery and radioiodine. This method of treatment may be particularly desirable in patients who are poor candidates for surgery and who refuse standard treatment.

Ethanol↗