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Biomedical subjects

I Yetkin

Publications and source records attributed to I Yetkin.

16 recordsLinked to original sources
PubMed2006

Gait deviations of patients with diabetes mellitus: looking beyond peripheral neuropathy.

AIM: The aim of this paper was to define the gait deviations in patients with diabetes mellitus (DM), to investigate the associations between electrophysiological findings and gait characteristics, and to interpret the findings in preventive and therapeutic rehabilitation protocols. METHODS: Forty-six patients with DM and 20 healthy control subjects were enrolled into this controlled study. Electrophysiological studies and computerized gait analysis were performed. Gait deviations of DM patients with diabetic peripheral neuropathy (DPN) (n=20), without diabetic peripheral neuropathy (NDPN) (n=26) and healthy control subjects (C) (n=20) were compared, and associations between electrophysiological findings and gait characteristics were investigated. RESULTS: NDPN, but not DPN, group revealed slower gait, shorter steps, limited knee and ankle mobility, lower ankle plantar flexor moment and power than C group, and the difference was statistically significant. HbA1c levels and F-wave latency were significantly correlated with ankle mobility, peak ankle plantar flexion moment and power. CONCLUSION: Neuropathy may not be the only reason for gait deviations in DM patients. Considering the spectrum of hyperglycemic complications including the mechanical characteristics of bones, muscles and soft tissues, patients with DM should start mobility and strengthening exercises in early stages.

Adult↗
PubMed2005

Ret proto-oncogene mutations in apparently sporadic Turkish medullary thyroid carcinoma patients: Turkmen study.

OBJECTIVE: Medullary thyroid carcinoma (MTC) frequently occurs in a sporadic form, but a substantial number of cases are hereditary and appear as part of the multiple endocrine neoplasia type 2 (MEN2) syndromes. Germline mutations in ret proto-oncogene have been shown to be the underlying cause of MEN2 syndromes. DESIGN: We carried out a multi-center study that aimed to perform mutational analysis of so called sporadic MTC patients. METHODS: Fifty-six MTC patients verified by histopathologic examination were subjected to genetic analysis. Exon 10, 11, 13, 14, 15 and 16 of the ret gene were analyzed by DNA sequencing and restriction enzyme digestion method. RESULTS: Among 56 apparently sporadic MTC patients, we identified 6 (10.7%) ret germline mutation carriers. Three individuals carried mutations at codon 634 in exon 11, one at codon 618 in exon 10, and two at codon 804 in exon 14. Identification of the predisposition gene mutation has allowed DNA-based strategy for direct mutation detection in patients with apparently sporadic MTCs. A substantial number of patients with apparently sporadic MTC carried germline mutations and 50% of their first degree relatives are expected to have or to develop MTC and/or other endocrine tumors. CONCLUSIONS: These results indicate the importance of careful genetic surveillance of any patient with apparently sporadic MTCs.

Adult↗
PubMed2004

The relationship between levels of alpha1-acid glycoprotein and metabolic parameters of diabetes mellitus.

The aim of this study was to investigate the relationship of alpha1-acid glycoprotein (AGP, orosomucoid), which is an acute-phase reactant, in patients with Type 1 (T1DM) and Type 2 diabetes mellitus (T2DM), with the metabolic parameters and complications of diabetes mellitus. A total of 119 diabetic patients (89 T2DM, 30 T1DM) and 33 healthy controls were included in the study. The mean AGP level in the diabetic group was not different from the control group (82.4 +/- 28.9 and 81.6 +/- 16.6 mg/dl, respectively), but it was higher in T2DM than in T1DM subjects (86.6 +/- 28.3 and 69.7 +/- 26.9, respectively). AGP plasma levels showed a significant correlation with age and body mass index (r = +0.348 and r = +0.296, respectively). AGP plasma levels resulted higher in obese diabetic patients (97.7 +/- 28.0) than in non-obese diabetic patients (77.6 +/- 28.7 mg/dl) and controls (81.6 +/- 16.6), and also higher in diabetic subjects with poor glycaemic control (85.1 +/- 33.3 mg/dl) than in diabetic subjects with optimal glycaemic control (79.5 +/- 23.1 mg/dl). A relationship between AGP and macro- and microvascular complications of diabetes mellitus was not found. In conclusion, inflammatory findings were more prominent in obese diabetic patients.

Acute-Phase Proteins↗
PubMed2003

Insulin secretion and insulin sensitivity in normal pregnancy and gestational diabetes mellitus.

The purpose of this study was to evaluate insulin sensitivity, beta-cell function and islet-cell-directed autoimmunity in pregnant women with normal glucose tolerance and gestational diabetes mellitus (GDM). A total of 21 women with normal glucose tolerance and 21 women with GDM were evaluated at 24-36 weeks' gestation. Insulin resistance and beta-cell function were evaluated using the continuous infusion of glucose with model assessment (CIGMA) method, which aims to give a near-physiological stimulus and to evaluate the endogenous insulin and glucose response. Islet-cell autoantibody was positive in one woman with GDM, and glutamic acid decarboxylase autoantibodies were negative in both groups. The calculated CIGMA insulin resistance (CIGMA IR) was 2.04 +/- 1.74 and 1.08 +/- 1.22 in patients with GDM and in control subjects, respectively (p < 0.05). CIGMA percentage beta-cell values were 64.04 +/- 44.55% and 87.07 +/- 52.77% in patients with GDM and control subjects, respectively (p > 0.05). Decreased insulin sensitivity in late pregnancy was more evident in lean GDM subjects with mild hyperglycemia who did not require insulin therapy, and beta-cell function was partially preserved in this group of patients.

Adult↗
PubMed2002

Pattern visual evoked potential (PVEP) evaluation in hypothyroidism.

Dysfunction of the central nervous system (CNS) is an important consequence of thyroid hormone deficiency. Evoked potentials like visual evoked potentials (VEP) provide a reliable and objective measure of function in related sensory system and tracts. In this study pattern-shift VEP (PVEP) recordings were performed on 48 newly diagnosed hypothyroid patients. Twenty-four had sub-clinical and 24 had overt hypothyroidism. None of the patients had clinical symptoms or signs referable to CNS dysfunction. Their mean age was 44+/-12 yr. The response to pattern stimulation on the normal control subjects was a triphasic response with a prominent positive wave (P100) with a peak latency of 84-105 (mean: 96+/-4) milliseconds (ms). In patients with hypothyroidism mean P100 latency was (mean: 97+/-6) ms and the difference between the 2 groups was not statistically significant. (p>0.05) Delays above the average latency +/-2.5 SD of the mean of the control subjects was defined as a criteria for an abnormality. According to defined criteria 6 (12.5%) patients demonstrated abnormal PVEP at least on one tested side. Previous studies conducted on small patient populations stated there is high percentage of VEP abnormalities in hypothyroid patients. However, this fact was not confirmed by our study. We believe abnormalities of PVEP will be more prominent in untreated patients in the advanced stage of the disease, or in patients who have a neurological involvement; such as apathy, impaired memory or cerebellar dysfunction. Consecutive studies, in a more clearly defined and selected patient population, are needed to confirm and settle this issue.

Adult↗
PubMed2002

Assessment of nerve fiber layer in diabetic patients with scanning laser polarimetry.

OBJECTIVES: To evaluate the effects of diabetes mellitus, diabetic retinopathy and degree of blood glucose (BG) regulation on retinal nerve fiber layer (RNFL) thickness by using a scanning laser polarimeter (NFA-GDx). METHODS: We prospectively assessed RNFL thickness in four groups of patients, who were all age matched. Diabetic patients without diabetic retinopathy were grouped according to their BG regulation level into two, as: BG-regulated group (BG <140 mg/dl, HbA1c <8%, fructosamine <285 micromol/l, TG <200 mg/dl, n = 50), and BG-non-regulated group (BG = 140-250 mg/dl, HbA1c >8%, fructosamine >285 micromol/l, TG >200 mg/dl, n = 44). A group of patients with nonproliferative diabetic retinopathy (NPDR) formed the 3rd group (n = 41). The 4th group consisted of healthy subjects and acted as a control group (n = 50). Symmetry, superior maximum, ellipse modulation and the average thickness variables of NFA-GDx were used for the assessment. ANOVA test was used for the statistical analysis of variables between groups. RESULTS: The mean superior maximum and ellipse modulation values were statistically significantly lower than the control group in BG-non-regulated and NPDR groups (P < 0.05). The average thickness value was also statistically significantly lower than the control group in NPDR group. These values in the BG-regulated group were not statistically significantly different from the control group (P > 0.05). CONCLUSIONS: This is the first clinical study demonstrating the effects of diabetic glucose regulation level on RNFL by using NFA-GDx. RNFL thickness was seen to decrease with development of diabetic retinopathy and with impairment of metabolic regulation. This issue should be taken into account while assessing RNFL in diabetic glaucomatous patients.

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

Facial nerve conduction in diabetic neuropathy.

Diabetes mellitus (DM) has a severe influence on the nervous system and it is more likely to occur on the nerves of the upper and lower extremities than on the cranial nerves. According to the statistics, the incidence of cranial nerve involvement ranges anywhere from 3% to 14%. The aim of this study is to perform facial nerve conduction studies in diabetic patients with peripheral neuropathy, confirmed by electrophysiological methods, to determine the frequency of affection of a cranial nerve conduction in a neuropathy which mainly occurs in a distal, symmetric fashion. The study was conducted in a group of 20 diabetics who had electrophysiologically confirmed polyneuropathy. All of the patients had type 2 DM. Sixteen of the patients were receiving insulin therapy and 4 were treated with oral hypoglycaemic agents only. We found prolonged facial nerve distal latency at least on one tested side in 70% of patients. Distal latency and amplitudes of muscle responses to facial nerve stimulation showed a statistically significant difference from controls (p < 0.001). This study has shown that proximal nerves like cranial nerves are affected in a high proportion of cases in a neuropathy which mainly occurs in a distal symmetric fashion. The facial nerve is one of the most easily accessible nerves in the proximal part of the body (head-face) and makes it suitable for routine evaluation. We believe this conduction abnormality may give us the chance to classify these neuropathies as more severe than the ones that only have limb conduction abnormalities. Further studies should be performed in order to confirm these findings.

Action Potentials↗
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

Magnetic resonance imaging of posterior pituitary for evaluation of the neurohypophyseal function in idiopathic and autosomal dominant neurohypophyseal diabetes insipidus.

We investigated the role of MR imaging for evaluation of the functional status of the neurohypophyseal system in both idiopathic central diabetes insipidus (DI) and familial autosomal dominant neurohypophyseal DI. The patients and family with DI were analyzed retrospectively for the presence or absence of posterior pituitary gland hyperintense signal on MR images. A total of 19 adult patients with idiopathic central DI, 7 members of a family with autosomal dominant DI and 20 control subjects were included in the study. Diagnosis of idiopathic DI was based on the presence of central DI in the absence of any alteration that is known to be responsible for DI. The patients were studied retrospectively and the morphology and intensity of the posterior lobe by MR imaging was assessed by blinded reading. In all patients with idiopathic central DI and the affected members of the family, the posterior bright signal was absent while the stalk was normal on MR images. In contrast, normal posterior pituitary bright signal and stalk were found in unaffected members of the family and all control subjects. We conclude that MR imaging of the posterior pituitary lobe can be used to evaluate the functional status of the neurohypophyseal system in idiopathic central DI and familial autosomal dominant DI.

Adolescent↗
PubMedDate not supplied

Current literature in diabetes.

In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of diabetes/metabolism. Each bibliography is divided into 17 sections: 1 Books, Reviews & Symposia; 2 General; 3 Genetics; 4 Epidemiology; 5 Immunology; 6 Prediction; 7 Prevention; 8 INTERVENTION: a&rpar General; b&rpar Pharmacology; 9 Pathology: a&rpar General; b&rpar Cardiovascular; c&rpar Neurological; d&rpar Renal; 10 Endocrinology & Metabolism; 11 Nutrition; 12 Animal Studies; 13 Techniques. Within each section, articles are listed in alphabetical order with respect to author (9 Weeks journals - Search completed at 1st Aug 2001)

Diabetes Mellitus↗
PubMedDate not supplied

Blink reflex abnormalities in diabetes mellitus.

BACKGROUND: Damage of the peripheral nervous system is particularly frequent in diabetes mellitus (DM), but somatic cranial neuropathies usually presenting as mononeuropathies are rare. Oculomotor and facial nerves are among the most commonly affected, whereas the Vth, IXth and Xth cranial nerves are less often affected. While existing neurophysiological tests in the subclinical diagnosis of damage to the peripheral nerve in diabetic patients have advanced, the same does not hold true for the subclinical diagnosis of the central nervous system (CNS). Electrophysiological studies such as the blink reflex was shown to be an effective method for revealing subclinical involvement of cranial nerves in generalised neuropathies. The aim of the present study was to evaluate the efficacy of blink reflex as a method for obtaining early diagnosis of cranial nerve involvement in diabetic patients frequently affected with peripheral neuropathy. METHODS: Twenty diabetic patients with electrophysiologically confirmed neuropathy were included in the present study for the evaluation of blink reflex. Patients with earlier cranial nerve involvement were excluded. RESULTS: Abnormal blink reflex responses were found in 55% of patients studied. R2Y and R2C latencies in diabetic patients were prolonged relative to controls (p<0.001 and p<0.001, respectively). However R1 values in diabetic patients did not differ significantly from those of normal controls (p<0.5). R2Y and R2C prolongation showed a positive correlation with the duration of disease (p=0.015 and p=0.009, respectively). However the same correlation could not be found with R1 values. No correlations were found between R1, R2Y, R2C values and HbA(1c) nor between R1, R2Y, R2C values and patients' age. CONCLUSION: We suggest that blink reflex testing is a useful method for obtaining early diagnosis of cranial nerve compromise in diabetic patients who do not show any clinical symptoms or signs of CNS involvement.

Aged↗
PubMedDate not supplied

Sympathetic skin response in diabetic neuropathy.

Autonomic neuropathy is a complication of diabetes mellitus (DM) in substantial proportion of cases and may cause definite autonomic symptoms. Because conventional electrophysiological methods do not assess the autonomic nervous system, simple reproducible tests were developed. One of them is sympathetic skin response (SSR) which provides useful information about the status of sympathetic postganglionic function. The aim of this study is to perform SSR in diabetic patients to see whether this test can be used as an electrophysiological method for the diagnosis and confirmation of diabetic autonomic neuropathy. 20 diabetic patients who had electrophysiologically confirmed polyneuropathy but showed no symptoms or signs referable to autonomic system dysfunction were included. 14 (70%) patients demonstrated abnormal SSR. 2 abnormal patterns were observed. An absent response in at least one tested lower extremity (50%) and prolonged foot with normal hand latency (20%). 6 patients (30%) demonstrated no abnormalities. Foot and hand latencies in diabetics did not differ significantly from those of normal controls (p: 0.4, p: 0.1) and no correlation could be found with latencies and duration of sickness, patient's age and HbA1c values. We believe latency measurement is an objective measure of conduction in multineural pathways and can detect subclinical involvement of sympathetic nervous system in diabetics who do not manifest symptoms or signs referable to autonomic system dysfunction.

Adult↗
PubMedDate not supplied

The prevalence of autoimmune hepatitis in Hashimoto's thyroiditis in a Turkish population.

PURPOSE: Hashimoto's thyroiditis (HT) is an autoimmune thyroid disorder. Although its etiopathogenesis is obscure, there are many findings about the relationship between other autoimmune diseases and HT. The reason for this association is a topic of interest, but in our study we searched for the concurrence of autoimmune hepatitis (AH) with HT, which is a relatively new autoimmune disorder for this association. METHODS: Forty-six patients (44 female, 2 male) with HT were included in the study. Liver function tests, viral hepatitis markers, autoantibody panels, ultrasonography and liver biopsy were performed in certain cases. RESULTS: All patients were hepatitis B negative, only two patients were hepatitis C positive (4.3%). Smooth muscle antibody (SMA) was 21.7% positive, ANA was 26% positive, Anti-Liver kidney microsomal antibody-1 (LKM-1) was 13.4% positive. Anti-mitochondrial antibody (AMA) was not detected. Liver biopsy performed on six patients. Two of them had (+++) positive LKM-1 antibody titer, the other two had ANA and SMA positive results respectively and the last two had chronic hepatitis C infection. The pathology revealed AH in first four patients. We found four out of forty-six patients with HT as AH (8.69%). CONCLUSION: HT patients should be searched for autoimmune diseases and AH might be one of them.

Adult↗
PubMedDate not supplied

Changes in intraocular pressure and corneal and retinal nerve fiber layer thicknesses in hypothyroidism.

PURPOSE: To evaluate the changes in intraocular pressure (IOP), corneal thickness (CT), and retinal nerve fiber layer thickness (RNFLT) in patients with hypothyroidism before and after treatment. METHODS: A complete ophthalmic examination including visual acuity, IOP, anterior segment, and fundus examination together with CT and RNFLT measurements were performed for each patient with newly diagnosed hypothyroidism, at the initial diagnosis and the third and ninth months of the L-thyroxine treatment. Wilcoxon signed rank test and Spearman's correlation test were used for statistical evaluation of the results. RESULTS: A total of 56 eyes of 28 patients were included in the study. The mean IOP and CT values were found to decrease with medical treatment (p = 0.000). There was no significant change in any of the RNFLT parameters measured with scanning laser polarimeter after L-thyroxine treatment (Wilcoxon, p > 0.05). The change in IOP levels was not correlated with the change in thyroid hormone levels (Spearman's correlation test, p > 0.05). The mean increase in serum free T3 and serum free T4 levels and the mean decrease in serum TSH levels at the ninth month of the therapy were found to be correlated with the decrease in CT in the left eyes (Spearman's correlation test, R > 0.4 and p < 0.05). CONCLUSIONS: Hypothyroidism seems to cause a reversible increase in CT and IOP. IOP changes may be secondary to CT changes. RNFLT parameters measured with scanning laser polarimeter do not seem to be affected by hypothyroidism. When the CT is taken into account and the IOPs corrected for CT, the prevalence of glaucoma in hypothyroidism may not be as high as previously reported. This issue should be taken into account while assessing glaucoma in patients with hypothyroidism.

Adult↗