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Biomedical subjects

A Aydin

Publications and source records attributed to A Aydin.

At least 19 recordsLinked to original sources
PubMed2000

A cholesterol-lowering gene maps to chromosome 13q.

A cholesterol-lowering gene has been postulated from familial hypercholesterolemia (FH) families having heterozygous persons with normal LDL levels and homozygous individuals with LDL levels similar to those in persons with heterozygous FH. We studied such a family with FH that also had members without FH and with lower-than-normal LDL levels. We performed linkage analyses and identified a locus at 13q, defined by markers D13S156 and D13S158. FASTLINK and GENEHUNTER yielded LOD scores >5 and >4, respectively, whereas an affected-sib-pair analysis gave a peak multipoint LOD score of 4.8, corresponding to a P value of 1.26x10-6. A multipoint quantitative-trait-locus (QTL) linkage analysis with maximum-likelihood binomial QTL verified this locus as a QTL for LDL levels. To test the relevance of this QTL in an independent normal population, we studied MZ and DZ twin subjects. An MZ-DZ comparison confirmed genetic variance with regard to lipid concentrations. We then performed an identity-by-descent linkage analysis on the DZ twins, with markers at the 13q locus. We found strong evidence for linkage at this locus with LDL (P<.0002), HDL (P<.004), total cholesterol (P<.0002), and body-mass index (P<.0001). These data provide support for the existence of a new gene influencing lipid concentrations in humans.

Adult↗
PubMed1999

Iodine and zinc, but not selenium and copper, deficiency exists in a male Turkish population with endemic goiter.

Although endemic goiter has been shown to have a high prevalence in Turkey, little is known about the concentration of urinary iodine, plasma selenium (Se), copper (Cu), and zinc (Zn) in these patients. We studied on 140 male patient with endemic goiter (mean age: 22.2 +/- 0.19 yr) and 140 healthy male subjects (mean age: 21.8 +/- 0.28 yr). Daily urinary iodine excretion was determined by the ionometric method. Plasma Se, Zn, and Cu were determined by using atomic absorption spectrometry. Daily urinary iodine excretion was found to be significantly lower in the patient group (38.7 +/- 2.26 microg/d) than that of controls (50.73 +/- 2.56 microg/day, p = 0.001). Plasma Zn concentrations were also found to be significantly lower in the patient group (1.04 +/- 0.03 microg/mL) than that of controls (1.16 +/- 0.02 microg/mL, p = 0.001). No significant difference was determined in Se and Cu concentrations between the patient and control groups. Our study shows that a moderate iodine deficiency exists in both patients with endemic goiter and control subjects, which indicates the important role of iodine deficiency in the etiopathogenesis of endemic goiter in Turkey. Zinc deficiency may also contribute to the pathogenesis of endemic goiter. However, Se and Cu do not seem to have any role in the etiopathogenesis of endemic goiter in Turkey. A community-based iodine fortification program throughout the country may be proposed to take over the problem, which also can prevent the contributing effects of other element deficiencies that occur when iodine deficiency is the prevailing factor.

Adult↗
PubMed1999

Prediction of nonsynonymous single nucleotide polymorphisms in human disease-associated genes.

Analysis of human genetic variation can shed light on the problem of the genetic basis of complex disorders. Nonsynonymous single nucleotide polymorphisms (SNPs), which affect the amino acid sequence of proteins, are believed to be the most frequent type of variation associated with the respective disease phenotype. Complete enumeration of nonsynonymous SNPs in the candidate genes will enable further association studies on panels of affected and unaffected individuals. Experimental detection of SNPs requires implementation of expensive technologies and is still far from being routine. Alternatively, SNPs can be identified by computational analysis of a publicly available expressed sequence tag (EST) database following experimental verification. We performed in silico analysis of amino acid variation for 471 of proteins with a documented history of experimental variation studies and with confirmed association with human diseases. This allowed us to evaluate the level of completeness of the current knowledge of nonsynonymous SNPs in well studied, medically relevant genes and to estimate the proportion of new variants which can be added with the help of computer-aided mining in EST databases. Our results suggest that approx. 50% of frequent nonsynonymous variants are already stored in public databases. Computational methods based on the scan of an EST database can add significantly to the current knowledge, but they are greatly limited by the size of EST databases and the nonuniform coverage of genes by ESTs. Nevertheless, a considerable number of new candidate nonsynonymous SNPs in genes of medical interest were found by EST screening procedure.

Databases, Factual↗
PubMed1999

Acetyl salicylic acid improves somatosensory evoked potentials in streptozotocin-diabetic rats.

The effects of acetyl salicyclic acid (ASA) on somatosensory evoked potentials (SEP) and neural levels of thiobarbituric acid reactive substances (TBARS), products of lipid peroxidation, were studied in streptozotocin-diabetic rats. ASA (100 mg/kg, in rat chow) was given to diabetic rats (n = 8) after the induction of diabetes for 16 weeks. ASA-treated normal control rats (n = 8), untreated diabetic rats (n = 8) and normal control rats (n = 8) were used for comparison. At the 8 weeks, SEP latency in diabetic group (15.4 +/- 0.5 ms) was significantly longer than that in normal control group (10.0 +/- 0.8 ms, P < 0.05). When compared to levels in diabetic control group, ASA shortened SEP latency significantly (12.7 +/- 0.1 ms; P < 0.05). This effect of ASA was significant in all three measurements from week 8 to 16 (P < 0.05 vs. diabetic control group). Neural TBARS level in diabetic control group (60.1 +/- 2.2 nmol/g) was significantly, higher than that in normal control group (28.5 +/- 3.6 nmol/g, P < 0.05). When compared to levels in diabetic control group, ASA depressed TBARS level significantly (41.5 +/- 12 nmol/g; P < 0.05). TBARS level in ASA-treated diabetic group (27.2 +/- 5.7 nmol/g) was comparable with that in normal control group (NS). These results suggest that ASA has beneficial effect on diabetic neuropathy and this effect may be related in part with prevention of lipid peroxidation.

Animals↗
PubMed1999

MRI and MRS in HMG-CoA lyase deficiency.

3-Hydroxy-3-Methylglutaryl coenzyme A lyase (HMG-CoA) deficiency is a rare inborn error of leucine catabolism. The disease is characterized by recurrent episodes of metabolic acidosis, hyperammonemia without ketosis, hypoglycemia, lethargy, hepatomegaly, and seizures. This study has evaluated the magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) findings of three patients with HMG-CoA deficiency. The common findings on all of the MRI scans were multiple, coalescent, marked lesions in periventricular white matter and arcuate fibers, most prominently in frontal or periatrial regions that were superimposed on diffuse, slightly hyperintense subcortical white matter signal. Involvement of the caudate nucleus and the dentate nucleus were observed in the reported patients. MRS studies by both STEAM and PRESS spectra of all patients revealed a decrease in N-acetylaspartate and elevation in both myoinositol and choline. A pathologic peak at 1.33 ppm, which is compatible with lactate, and a particular peak at 2.42 ppm in all patients were also found. The combination of both MRI and MRS findings could be considered as being specific in patients with HMG-CoA lyase deficiency.

Amino Acid Metabolism, Inborn Errors↗
PubMed1999

Aluminum content of vaccines used in Turkey.

Aluminum salts have been used in the preparation of a number of vaccines, toxoids, and allergen injectants as an adjuvant for many years. Although aluminum allergy is rare, there are many reported cases caused by aluminum-precipitated vaccines or hyposensitization therapy. Therefore, determination of the aluminum content of these vaccines is necessary information regarding adverse reactions related to these vaccines. In the present study, the aluminum contents of several vaccines (n = 19) routinely used in Turkey were, determined by electrothermal atomic absorption spectrophotometry. We found that aluminum levels in the vaccines ranged from 0.0 to 1438 mg/L.

Aluminum↗
PubMed1999

In vitro corrosion behaviour and microhardness of high-copper amalgams with platinum and indium.

Samples prepared from Luxalloy, GS-80, Permite-C and Logic and polished after 24 h by traditional methods were stored in polypropylene tubes containing phosphate-buffered saline solutions (pH 3.5 and 6.5) and distilled water. The amounts of mercury, silver, tin, copper, zinc, platinum and indium in the test solutions were determined at the first, second, eighth, 52nd and 78th week by atomic absorption spectrometry. At the end of the eighth week the amalgam samples were removed from solutions and evaluated by Rockwell Super Scial Microhardness tester. Statistically significant low amounts of metal ions were measured for Permite-C containing indium and Logic containing platinum. The microhardness test results showed that there were statistically significant increases in the microhardness of Permite-C and Logic. As a result it was shown that the amalgam samples were affected from corrosion conditions to different degrees. Sample of the Logic group that was stored in distilled water, showed smoother surface properties than other amalgam samples containing high copper. However, it was observed that samples of Permite-C group had the smoothest surface properties.

Analysis of Variance↗
PubMed1999

Noradrenaline and nitrite-nitrate concentrations in the contralateral testes during ipsilateral spermatic cord torsion in the presence or absence of a testis and epididymis.

OBJECTIVE: To determine the changes occurring during ipsilateral spermatic cord torsion either in the presence or absence of the ipsilateral testis and epididymis, by evaluating noradrenaline and nitrite-nitrate concentrations in the contralateral testes. MATERIALS AND METHODS: Forty male albino rats were allocated randomly to one of four equal groups undergoing: group 1, a sham operation; group 2, ipsilateral spermatic cord torsion; group 3, epididymo-orchidectomy only; and group 4, spermatic cord torsion after epididymo-orchidectomy. The contralateral testes were harvested after 24 h and the noradrenaline and nitrite-nitrate contents determined. The levels in each group were compared using the Kruskal-Wallis and Mann-Whitney U-tests. RESULTS: The noradrenaline content of testes from group 2 was significantly lower than in those of groups 1 and 3, but there were no significant differences in content between groups 1 and 3, 1 and 4, and 2 and 4. The content in group 4 was significantly less than that in group 3. There were no significant differences in nitrite-nitrate contents among any of the groups. CONCLUSION: Spermatic cord torsion for 24 h, either in the presence or absence of a testis and epididymis, significantly decreased the noradrenaline content in the contralateral testis. This finding supports the suggestion that the sympathetic system is activated by exposure to noradrenaline in the contralateral testis during ipsilateral spermatic cord torsion, with no dependency on the presence of a testis and epididymis. As the nitrite-nitrate concentrations were unaffected, nitric oxide seems to have no role in contralateral testicular deterioration.

Animals↗
PubMed1999

Multifocal omental mesenteric inflammatory pseudotumor (plasma cell granuloma).

Inflammatory pseudotumor (IP) is an uncommon benign tumor during childhood. The most common location is lung, and sporadic cases of IP with extrapulmonary involvement such as liver and abdomen are reported. However, the IP among the reported cases have appeared as solitary masses. A multifocal IP in a 14-year-old girl presumed to result following an Entamoeba histolytica infestation is reported.

Adolescent↗
PubMed1999

Linkage but lack of association for blood pressure and the alpha-adducin locus in normotensive twins.

BACKGROUND: alpha-adducin is a cytoskeletal protein involved with sodium-pump activity in the renal tubule. The alpha-adducin gene locus has been linked to hypertension and a polymorphism identified which is associated with hypertension; however, the role of the alpha-adducin gene locus in normal blood pressure regulation is not defined. We performed a combined linkage and association study in normotensive monozygotic (MZ) and dizygotic (DZ) twins and their parents to address this issue. METHODS: We studied 126 MZ and 70 DZ twin pairs and parents of DZ twins. Blood pressure values and responses to a cold pressor test were obtained. Cardiac dimensions were measured echocardiographically. Three microsatellites adjacent to the alpha-adducin gene were studied as well as the 460 Trp mutation in the alpha-adducin gene. RESULTS: We obtained strong evidence for linkage (P< 0.001) between the alpha-adducin gene locus and systolic blood pressure. However, we were not able to associate the 460 Trp mutation with higher blood pressures, cold pressor responses or cardiac dimensions. CONCLUSIONS: The alpha-adducin gene locus is relevant to blood pressure regulation in normal subjects. Failure to find an association between higher blood pressures and the 460 Trp mutation suggests that this mutation may become important only when hypertension is triggered, or that other variations in alpha-adducin are present which have not yet been discovered.

Adolescent↗
PubMed1999

Intestinal permeability in liver cirrhosis.

OBJECTIVE: To determine the changes in intestinal permeability in liver cirrhosis and to investigate whether intestinal permeability relates to the stage and aetiology of cirrhosis or existence of spontaneous bacterial peritonitis (SBP). DESIGN: A prospective study of intestinal permeability in patients with cirrhosis. SETTING: Gastroenterology and Nuclear Medicine Departments of Ege University Hospital. PARTICIPANTS: Intestinal permeability was assessed in 44 consecutive patients with cirrhosis and 10 healthy volunteers by measuring 24 h urine excretion of (99m)technetium diethyl triamine penta-acetic acid (99mTc DTPA). Cases with an associated disease, impaired renal function, continuing alcohol consumption and drug intake which is known to have an effect on intestinal permeability were excluded. MAIN OUTCOME MEASURES: Comparisons of 24 h urine excretion of 99mTc DTPA were made between the groups of cirrhotics and controls, different grades of cirrhosis (according to Child-Pugh criteria), alcoholic and non-alcoholic cirrhotics and cirrhotic patients with and without SBP. RESULTS: Patients with cirrhosis excreted 99mTc DTPA significantly more than controls (11.56 +/- 8.96% in cirrhotics and 4.30 +/- 1.49% in controls, P < 0.0001). There was no relationship of 24 h urine excretion of the tracer with the grade and aetiology of cirrhosis (12.20 +/- 9.47%, 11.41 +/- 9.84%, and 11.09 +/- 8.42%, in Child A, B, and C groups and 8.45 +/- 6.57% and 12.05 +/- 9.25% in alcoholic and non-alcoholic cirrhotics, respectively). No significant difference was found between cirrhotic patients with and without SBP in terms of excretion of the administered dose of 99mTc DTPA (9.98 +/- 9.47% and 12.20 +/- 8.82%, respectively). CONCLUSIONS: This study shows that intestinal permeability increased in cirrhotic patients regardless of the grade and aetiology of disease. The presence of SBP does not seem to be due to increased intestinal permeability.

Bacterial Infections↗