Esra Tug

Interleukin-10 gene promoter polymorphism in patients with schizophrenia in a region of East Turkey.

Schizophrenia is one of the most severe psychiatric disorders, with a worldwide incidence of 1%. Immunological abnormalities have been found to be associated with schizophrenia for decades. Cytokines are key proteins involved in the immune system activation. Interleukin-10 (IL-10), an important immunoregulatory cytokine, is located on chromosome 1q31–32, a region previously reported to be linked to schizophrenia in genetic studies. In the present study it was aimed to examine the IL-10 gene promoter regions polymorphic variants in patients with schizophrenia in a population of the Elazig Region of East Anatolia, Turkey. Polymorphisms at position −1082, −819 and−592 in the IL-10 promoter region were determined in 171 Turkish patients who were diagnosed with schizophrenia, based on the DSM-IV, and 168 healthy controls, by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). We analyzed allele, genotype, and haplotype distributions using a case–control association study. Genotyping was performed by RFLP. Statistically significant differences were observed in both allelic and genotypic frequencies of the−592A/C polymorphism (Allele, P=0.034, OR = 1.26, 95% CI 1.02–1.56; Genotype, P=0.048), while the other two polymorphisms in distribution of the alleles and genotypes in patients with schizophrenia were not significantly different from those of controls (P>0.05). Our results show a significant increase of GTA homozygotes (the high IL-10-producing haplotype) in schizophrenic patients compared to control subjects (P=0.0001). These data suggest that the IL-10 gene promoter polymorphism may be one of the susceptibility factors to develop schizophrenia in the Turkish population, and apparently in all humans.

The value of interleukin-12B (p40) gene promoter polymorphism in patients with schizophrenia in a region of East Turkey

Aims:  It has been hypothesized that the activation of the immune system may be involved in the neuropathological changes occurring in the central nervous system of schizophrenic patients. Cytokines play a key role in the activation of the immune system. Moreover, they strongly influence the dopaminergic, noradrenergic and serotonergic neurotransmission. To the best of our knowledge, in schizophrenic patients, plasma levels of interleukin (IL)‐12 were investigated only in one study, where deregulation of IL‐12 was determined. However, genotypical variations of the IL‐12B (p40) gene have not been investigated for schizophrenic patients yet. Therefore, in the present study, we aimed to examine polymorphic variants of IL‐12B (p40) gene promoter region in patients with schizophrenia in a population of the Elazig Region of East Anatolia, Turkey.

A Turkish family with Nance-Horan syndrome due to a novel mutation

Nance-Horan Syndrome (NHS) is a rare X-linked syndrome characterized by congenital cataract which leads to profound vision loss, characteristic dysmorphic features and specific dental anomalies. Microcornea, microphthalmia and mild or moderate mental retardation may accompany these features. Heterozygous females often manifest similarly but with less severe features than affected males. We describe two brothers who have the NHS phenotype and their carrier mother who had microcornea but not cataract. We identified a previously unreported frameshift mutation (c.558insA) in exon 1 of the NHS gene in these patients and their mother which is predicted to result in the incorporation of 11 aberrant amino acids prior to a stop codon (p.E186Efs11X). We also discussed genotype-phenotype correlation according to relevant literature.

Cochlear involvement in Familial Mediterranean Fever: A new feature of an old disease

OBJECTIVES In this study we first aimed to assess the cochlear functions in children with Familial Mediterranean Fever. The second aim was to investigate the correlation between the hearing levels and some clinical features of Familial Mediterranean Fever including the duration of the disease, age at onset, genetic analysis and colchicine use. METHODS Thirty-four children with Familial Mediterranean Fever and 27 age matched children were included in the study. Following otologic examination, all children underwent audiometric evaluation, including Pure Tone Average measurements and Distortion Product Otoaoustic Emission testing. Audiological results of the two groups were compared and correlation between the audiologic status and clinical parameters of the disease like the duration of disease, age at onset, mutations and colchicine treatment were studied. RESULTS Pure tone audiometry hearing levels were within normal levels in both groups. Hearing thresholds of Familial Mediterranean Fever patients were found to be increased at frequencies 8000, 10,000, 12,500 and 16,000 (p<0.05). In otoacoustic emission evaluation, distortion products and signal-noise ratio of FMF children were lower in the tested frequencies, from 1400 Hz to 4000 Hz (p<0.05). Interaction of the disease duration and age of disease onset was found to predict hearing levels, distortion products and signal-noise ratios of children with Familial Mediterranean Fever (F value=2.034; p=0.033). CONCLUSIONS To our knowledge this is the first study demonstrating cochlear involvement in children with Familial Mediterranean Fever which showed increased hearing thresholds at higher frequencies in audiometry together with decreased distortion products and signal-noise ratios demonstrated by distortion product otoacoustic emission testing. Similar studies must be carried out on adult patients to see if a clinical hearing impairment develops. The possible mechanisms that cause cochlear involvement and the effect of colchicine treatment on cochlear functions must be enlightened.

Tumor suppressor gene alterations in patients with malignant mesothelioma due to environmental asbestos exposure in Turkey

Background Environmental asbestos exposure can cause the grave lung and pleura malignancies with a high mortality rate, and it is also associated with increased rate of other organ malignancies. Asbestos exposure can develop genotoxic effects and damage in the pleura and lungs. Objective In this study, we aimed to determine tumor suppressor gene (TSG) loss in genomic DNA which was isolated from pleural fluid and blood samples of patients with Malignant Pleural Mesothelioma (MPM) due to environmental asbestos exposure. Design and patients Prospective study of period from 2001 to 2003 in 17 patients with MPM. Methods A total of 12 chromosomal regions were researched by comparing genomic DNA samples isolated from blood and pleural effusion (using PCR, and polyacrilamid gel electrophoresis denaturizing), on 2 different chromosomes which have 9 different polymorphic determinants at 6q and 3 different polymorphic determinants at 9p using molecular genetic methods on 13 patients clinico-pathologically diagnosed MPM. Results Loss of Heterozygosity (LOH) was determined at D6S275 in one patient, at D6S301 in another, at D6S474 in 2, at ARG1 in 2, at D6S1038 in 2 and at D6S1008 in 3 patients. In 7 (54%) of the13 patients, we found LOH in at least one site. No LOH was determined at any informative loci in 6 patients. Of the 13 patients, no investigated markers were determined at 9p. Conclusion In this study, genomic DNA samples obtained from MPM patients with asbestos exposure revealed that they contained important genotoxic damage. We found no other study on this subject at molecular level in pleural effusion either in Turkey or in the med-line literature. We believe that this study will provide important support for other research into molecular-genetic variations, both on this subject and other malignancies, and may also constitute a base for early diagnosis and gene therapy research in the future.

Lack of an effect of CYP3A4 and MDR1 gene polymorphisms on colchicine pharmacogenetics in the treatment of Familial Mediterranean fever.

The P-gp/MDR1 multidrug transporter mediates detoxification of numerous drugs, including colchicine, and CYP3A4 is key to the biotransformation of colchicine. We investigated the effects of CYP3A4 and P-gp/MDR1 polymorphisms on bioavailability of colchicine in patients with Familial Mediterranean fever (FMF). Forty-eight Turkish patients with FMF treated with colchicine were genotyped for 3435C>T, (-)1A>G, 61A>G, 1199G>A, 1236C>T, 2677G>A, 2677G>T polymorphisms in the P-gp/MDR1 gene and 3435C>T, 1B(-392A>G), 2(15713T>C), 3(23171T>C), 12(21896C>T), 17(15615T>C) polymorphisms in the CYP3A4 gene. Doses of colchicine administered to patients did not differ with respect to P-gp/MDR1 or CYP3A4 gene polymorphism. We also determined the genotype distributions of CYP3A4 and P-gp/MDR1 genes among FMF patients. There was no significant gender difference in the P-gp/MDR1 polymorphism, whereas there were significant gender differences in the frequencies of 15713T>C and 15615T>C polymorphisms in the CYP3A4 gene. No significant relationship was found between colchicine doses that would introduce optimal clinical response and affect the therapeutic dose and CYP3A4 and P-gp/MDR1 gene polymorphisms in these FMF patients.

The evaluation of long-term effects of ionizing radiation through measurement of current sister chromatid exchange (SCE) rates in radiology technologists, compared with previous SCE values

Ionizing radiation is a strong physical mutagen, causing breakage of phosphodiester bonds in DNA at any stage of the mitotic cycle. Analysis of sister chromatid exchange (SCE) has come into use as a sensitive DNA-damage indicator. We investigated the SCE rates in radiology technologists who are occupationally and chronically exposed to ionizing radiation. The study included 39 radiology technologists and 35 sex- and age-matched healthy controls. There was a statistically significant difference in the SCE frequency between radiology technologists and controls (p<0.0001). Additionally, previous SCE data of 10 radiology technologists were compared with current results regarding radiation exposure time. There was statistically significant difference between previous and current SCE values (p=0.005). The significant increase in the frequency of SCE in radiology technologists emphasizes the importance of radiation-protection procedures in order to minimize radiation exposure and avoid possible genotoxic effects. Comparison of two studies that measured SCE values of radiology technologists after 8 years also suggests that the genotoxic effect is reversible. In conclusion, radiation is still an important mutagenic agent despite improvements in daily working hours and conditions.

The effect of octreotide, an analog of somatostatin, on bleomycin-induced interstitial pulmonary fibrosis in rats

In this study, octreotide (OCT), a synthetic somatostatin analog, was tested for its beneficial effects in the prevention of interstitial pulmonary fibrosis (IPF) induced by bleomycin (BLM) in rats by histological examination and by evaluating tissue OH-proline levels. Thirty male Wistar rats were divided randomly into three groups: group I: intratracheal (i.t.) BLM (7.5 mg/kg, single dose) + saline solution [0.9% NaCl, subcutaneously (s.c.), once-daily for 7 days]; group II: i.t. BLM (7.5 mg/kg, single dose) + OCT acetate (82.5 µg/kg, s.c., once-daily for 7 days); and the control group. At the end of the 7 days, lung tissues were excised and examined by histopathological methods. Levels of tissue hydroxyproline (OH-proline) were determined. BLM administration resulted in prominent histopathologic findings, such as diffuse alveolar damage and interstitial pulmonary fibrosis, as well as a significant increase in OH-proline level, as compared to controls. OCT application explicitly attenuated the histopathologic changes to a significant extent. OCT decreased paranchymal fibrosis and structural deformities in BLM-induced lung fibrosis. These results suggest that OCT administration to rats with BLM-induced IPF has a protective effect. Further studies are necessary to reveal the molecular mechanism(s) of OCT-induced protective effect.

Mapping of Microsatellite Instability in Endoscopic Normal Colon

Genomic instability in colorectal cancer (CRC) occurs as either microsatellite instability (MSI) or chromosomal instability. The present study was aimed at examining the MSI for the MLH1 and MSH2 genes in normal colon and polyps, if detected. Four segments of the colon were sampled in 102 subjects during colonoscopy. DNA samples were analyzed for the MSI status according to the Bethesda consensus panel. Family history of any type of cancer or for colon cancer was present in 44.8% and 9.4% of the individuals, respectively. Forty-eight percent of individuals were microsatellite stable for all five markers at all locations, 20% had low MSI status (MSI-L), and 32% had high MSI status (MSI-H). The frequencies of MSI markers differed significantly from each other (p=0.003). The most frequent positive marker was D17S250. This is the first study which revealed that MSI is present in endoscopically normal-looking colon of normal individuals and, more frequently, in individuals with family histories of CRC. The detection of very early-stage CRC is possible by MSI analysis of DNA mismatch repair genes in colon tissues. This study has revealed crucial information for the use of molecular tests in CRC screening, such as high frequencies of MSI in endoscopically normal colon, which might cause false positivity.

Identification of an Alu-mediated 12.2-kb deletion of the complete LPAR6 (P2RY5) gene in a Turkish family with hypotrichosis and woolly hair

Hypotrichosis is a rare form of progressive hair loss characterized by sparse and occasionally woolly hair that is curly and breaks easily. Disease‐causing mutations in LIPH, LPAR6 and KRT74 have recently been identified. We describe a four‐generation pedigree from Turkey following an autosomal recessive pattern, in which the four affected members had hypotrichosis and woolly hair. By sequencing LPAR6 and the use of SNP arrays, we revealed a homozygous loss of the entire LPAR6 gene in the affected individuals. We hypothesize that the 12‐kb deletion resulted from illegitimate recombination secondary to slip‐replication. The orientation of three Alu repeats around LPAR6 may have provoked the formation of a ‘triple‐barrel’ structure during replication, thereby allowing strand slipping. This first report of complete LPAR6 loss expands the spectrum of known LPAR6 mutations and suggests a novel mechanism for this gene and for the formation of DNA rearrangements in general.