Is there any relationship between human foamy virus infections and familial Mediterranean fever?

Background:

Familial Mediterranean fever (FMF) is generally defined as an autosomal recessive disease, characterized by the automatic activation of the innate immune system in the absence of a detectable pathogenic stimulant. We hypothesize that the pathogenic factors, besides the genetic causes, may affect the development of FMF symptoms. To test this hypothesis, we examined the effects of human foamy virus (HFV) positivity on the occurrence of the clinical symptoms of FMF.

Materials and Methods:

Two hundred and twenty-two FMF patients with definitive diagnosis according to Tel Hashomer criteria (study group 1 [SG1]), 205 symptomatic FMF patients who had definitive diagnosis according to the same criteria but did not carry any of the 12 most commonly occurring MEFV gene mutations (study group 2 [SG2]), and 200 healthy individuals were included as control group (study group 3 [SG3]) in the study. The genetic analysis was applied in the Molecular Genetics Laboratory of the Department of Medical Biology, Faculty of Medicine, Ondokuz Mayıs University. This study was designed as a case-control study. HFV positivity was tested by amplifying the HFV bel1 gene sequence with polymerase chain reaction technique. Statistical analyses were conducted using SPSS version 23.0 software.

Results:

HFV positivity showed significant differences between the study groups (P = 0.002). While 43 (19.02%) of the 222 SG1 patients were positive for the HFV bel1 gene sequence, 33 (16.09%) of the 205 SG2 patients were positive for the same sequence. Only 15 (7.5%) of the SG3 participants were positive for the presence of HFV bel1 gene sequence.

Conclusion:

The results of our study suggested that HFV positivity can be a stimulant pathogenic factor of natural immune system which can cause the emergence of FMF symptoms.

Changes in irisin levels in patients with hyperemesis gravidarum

PURPOSE

The aim of this study was to compare levels of serum irisin in hyperemesis gravidarum (HG) patients to healthy gravidas.

MATERIALS AND METHODS

Twenty pregnant women with hyperemesis gravidarum (Group 1) and 20 healthy pregnant women (Group 2) all of similar ages, body mass index, and all at similar pregnancy development comprised the study cohort. Fasting serum samples were obtained and measured for irisin levels. Comparisons between groups were done by Mann Whitney U (MWU) test and p < 0.05 was considered as statistically significant.

RESULTS

All the patients in groups 1 and 2 were primigravid and age, gestational week, and body mass index values were similar. No statistically significant difference were present among these parameters (p > 0.05, MWU test). The plasma irisin concentrations in group 1 were significantly higher (irisin (average ±S D): 116.9 ± 32.3 ng/ml vs. 87.7 ± 26.2 ng/ml) compared to the control group.

CONCLUSION

This study suggests a possible role of irisin, which might be involved in the pathology of HG.

Exome Sequencing Reveals AGBL5 as Novel Candidate Gene and Additional Variants for Retinitis Pigmentosa in Five Turkish Families

PURPOSE

Retinitis pigmentosa (RP) is the most common inherited retinal disease with high genetic heterogeneity and variable phenotypes. Characteristic symptoms include night blindness and progressive loss of visual field, leading to blindness. Mutations in >60 genes have been identified to date as causative for RP, and additional candidate genes are assumed.

METHODS

To find the disease-causing mutations in the affected members of five Turkish families, we sequenced whole exomes using an Illumina platform.

RESULTS

Among all candidate genes for retinal degeneration we found two previously known sequence variations: a 4 bp deletion in the RPGR gene (c.1662_1665delAGAA; p.Glu555Glyfs*14) and a recently described USH1-causing missense mutation in MYO7A (c.472G>A, p.Gly158Arg). Furthermore, a novel 1 bp deletion in the VCAN gene (c.5118delA; p.Ser1707Valfs*44) was detected as well as a large deletion in EYS, spanning ∼ 400kb and comprising exons 16-26 (p.fs*). In one family, exome analyses of two affected individuals revealed a homozygous missense mutation (c.883G>A; p.Asp295Asn) in the AGBL5 (Agbl5; CCP5) gene, previously not reported to be associated with RP. RNA and protein analyses showed expression in human retina, as well as in mouse retina, brain and testis. Furthermore, cDNA analyses indicate the existence of tissue-specific AGBL5 splice variations in humans. AGBL5/CCP5 immunoreactivity was also visualized in human and mouse retinae.

CONCLUSION

Due to the characteristic RP phenotype in patients carrying the AGBL5 missense mutation we suggest this gene as a candidate for a new form of autosomal recessively inherited RP and recommend further investigation to confirm this hypothesis.

Impaired cell death and mammary gland involution in the absence of Dock1 and Rac1 signaling

Throughout life, the tight equilibrium between cell death and the prompt clearance of dead corpses is required to maintain a proper tissue homeostasis and prevent inflammation. Following lactation, mammary gland involution is triggered and results in the death of excessive epithelial cells that are rapidly cleared by phagocytes to ensure that the gland returns to its prepregnant state. Orthologs of Dock1 (dedicator of cytokinesis 1), Elmo and Rac1 (ras-related C3 botulinum toxin substrate 1) in Caenorhabditis elegans are part of a signaling module in phagocytes that is linking apoptotic cell recognition to cytoskeletal reorganization required for engulfment. In mammals, Elmo1 was shown to interact with the phosphatidylserine receptor Bai1 and relay signals to promote phagocytosis of apoptotic cells. Still, the role of the RacGEF Dock1 in the clearance of dying cells in mammals was never directly addressed. We generated two mouse models with conditional inactivation of Dock1 and Rac1 and revealed that the expression of these genes is not essential in the mammary gland during puberty, pregnancy and lactation. We induced mammary gland involution in these mice to investigate the role of Dock1/Rac1 signaling in the engulfment of cell corpses. Unpredictably, activation of Stat3 (signal transducer and activator of transcription 3), a key regulator of mammary gland involution, was impaired in the absence of Rac1 and Dock1 expression. Likewise, failure to activate properly Stat3 was coinciding with a significant delay in the initiation and progression of mammary gland involution in mutant animals. By using an in vitro phagocytosis assay, we observed that Dock1 and Rac1 are essential to mediate engulfment in epithelial phagocytes. In vivo, cell corpses accumulated at late time points of involution in Dock1 and Rac1 mutant mammary glands. Overall, our study demonstrated an unsuspected role for Dock1/Rac1 signaling in the initiation of mammary gland involution, and also suggested a role for this pathway in the clearance of dead cells by epithelial phagocytes.

SOX4 expression levels in urothelial bladder carcinoma

High levels of SOX4 gene expression have been reported in a variety of human cancers. The protein may function in the apoptosis pathway, leading to cell death as well as to tumorigenesis. The aim of this study was to investigate the levels of SOX4 expression in bladder cancer. Urinary bladder tumor samples were obtained from 57 bladder cancer and 13 normal bladder biopsies. The levels of SOX4 expression in bladder cancer were determined by immunohistochemistry and real-time PCR. SOX4 gene expression was increased 2.2 times in bladder tumors as compared with normal tissue. The presence of protein was confirmed by immunostaining. There were significant differences between immunostaining of bladder tumors and normal bladder tissue (P=0.001). The present data suggest that SOX4 gene may have a role in bladder cancer tumorigenesis.

Interaction between periodontal disease and systemic secondary amyloidosis: from inflammation to amyloidosis

BACKGROUND

It has become increasingly clear in recent years that periodontal disease can cause a dramatic increase in the levels of markers of systemic inflammation, and that periodontal treatment can result in reduction in the levels of these markers. We have previously shown that the prevalence of moderate to severe periodontitis was significantly higher in patients with familial Mediterranean fever (FMF) with amyloidosis than in patients with FMF without amyloidosis. Thus, the aim of this study is to investigate if chronic periodontitis is associated with secondary amyloidosis in the Black Sea region of Turkey.

METHODS

A total of 112 patients with biopsy-proven secondary amyloidosis (59 patients with FMF, 40 patients who were either chronically infected or had malignant disease, 13 patients with periodontitis) and 22 healthy subjects, were included in this study. Periodontal health and disease were evaluated using gingival index (GI), papillary bleeding index (PBI), plaque index (PI), and periodontal disease index (PDI). The concentrations of serum acute phase reactants (APRs) were measured at baseline and at 4 to 6 weeks after completion of the non-surgical periodontal therapy.

RESULTS

The prevalence of moderate to severe periodontitis was 47.5% in patients with FMF, 72.5% in patients who were either chronically infected or had malignant disease, and 84.6% in patients with periodontitis. Serum levels of APRs in patients with amyloidosis were reduced significantly after non-surgical periodontal therapy (P <0.01).

CONCLUSIONS

Periodontitis can increase the levels of APRs and potentiate the development of amyloidosis either by themselves or association with traditional factors, such as FMF and other chronic inflammatory diseases. Thus, preventing or treating periodontitis might prevent or at least alleviate the progression of amyloidosis. Periodontal evaluation should be performed as part of a medical assessment and considered as an etiologic factor for secondary amyloidosis.

Homozygous feature of isolated triphalangeal thumb-preaxial polydactyly linked to 7q36: no phenotypic difference between homozygotes and heterozygotes

Preaxial polydactyly is a common limb malformation in humans with variable clinical expression. Different types of triphalangeal thumb-preaxial polydactyly phenotypes were mapped to the chromosome 7q36 region. We studied a large Turkish family of 69 individuals, of whom 22 individuals were affected. In all, 11 affected family members were clinically and radiologically evaluated. All affected individuals had a triphalangeal thumb and a preaxial (hypoplastic) extra digit bilaterally, with minimal intrafamilial variation. No feet involvement was observed. Linkage and haplotype analyses using 20 informative meioses confirmed the 7q36 region contained the LIMBR1 gene. Maximum logarithm of the odds (LOD) scores were obtained with DNA markers D7S550 and D7S2423. We have further identified a novel C to T alteration at position 4909 bp in the critical zone of polarizing activity regulatory sequence (ZRS) region, in the intron 5, of the LMBR1 gene. One affected male with homozygous status and no phenotypic difference from affected family members with heterozygous status represented the first homozygote case of the triphalangeal thumb-preaxial polydactyly phenotype.

Spinal reflexes in normal and sulfite oxidase deficient rats: effect of sulfite exposure

Sulfites, which are commonly used as food preservatives, are continuously formed in the body during metabolism of sulfur-containing amino acids. Sulfite is oxidized to sulfate ion by sulfite oxidase (SOX, EC. 1.8.3.1). Although sulfite treatment has been reported to increase the excitability of some neurons in vitro, the possible effects of sulfite on neuronal excitability in vivo remain unclear. The aim of this study was to investigate the possible effects of sulfite treatment on spinal reflexes in anesthetized SOX competent and deficient rats. For this purpose, male albino rats used in this study were divided into four groups such as control group (C), sulfite group (CS), SOX deficient group (D), and SOX deficient + sulfite group (DS). Rats in SOX deficient groups were made deficient in SOX by the administration of low molybdenum (Mo) diet (AIN 76, Research Dyets Inc., USA) with concurrent addition of 200-ppm tungsten (W) to their drinking water in the form of sodium tungstate (NaWO4). Sulfite in the form of sodium metabisulfite (Na2O5S2, 70 mg/kg) was given orally by adding to drinking water to the S and DS groups. Monosynaptic reflex potentials were recorded from the ipsilateral L5 ventral root. SOX deficient rats had an approximately 15-fold decrease in hepatic SOX activity compared with normal rats. This makes SOX activity of SOXD rats in the range of human SOX activity. The results of this study show that sulfite treatment significantly increases the amplitude of the monosynaptic reflex response in both S and DS groups with respect to their respective control groups (C and D). SOX deficient rats also had enhanced spinal reflexes when compared with control rats. In conclusion, sulfite has increasing effects on the excitability of spinal reflexes and we speculate that this compound may exhibit its effects on nervous system by affecting sodium channels.

Periodontal disease in patients with familial Mediterranean fever: from inflammation to amyloidosis

BACKGROUND AND OBJECTIVE

Familial Mediterranean fever stimulates a very intense acute-phase reactants response and if left untreated eventually leads to amyloidosis. The aim of this study was to determine the prevalence of periodontal disease among patients with familial Mediterranean fever in the Black Sea region in Turkey and to evaluate whether periodontitis is related to amyloidosis in patients with familial Mediterranean fever.

MATERIAL AND METHODS

One-hundred and thirty three patients with familial Mediterranean fever and 50 healthy subjects were included in this study. Periodontal health and disease were evaluated using the gingival index, papillary bleeding index, plaque index and periodontal disease index. The concentrations of serum acute-phase reactants were measured at baseline and at 4-6 wk after completion of the nonsurgical periodontal therapy. Genetic testing for familial Mediterranean fever was performed using the familial Mediterranean fever StripAssay. Kidney biopsy was carried out on all proteinuric patients.

RESULTS

The prevalence of moderate to severe periodontitis in familial Mediterranean fever patients with amyloidosis (80.6%) was significantly greater (p < 0.01) than in familial Mediterranean fever patients without amyloidosis (38%) and in controls (20%). Serum levels of acute-phase reactants in familial Mediterranean fever patients were reduced significantly following nonsurgical periodontal therapy (p < 0.01).

CONCLUSION

Periodontal therapy seems to reduce the serum levels of acute-phase reactants in patients with familial Mediterranean fever. Therefore, treating periodontitis might help to alleviate the disease burden in patients with familial Mediterranean fever.

Diffuse multicystic encephalomalacia in a preterm baby due to homozygous methylenetetrahydrofolate reductase 677 C-->T mutation

Methylenetetrahydrofolate reductase catalyzes the formation of 5-methyltetrahydrofolate from 5,10-methylentetrahydrofolate and produces folate for the methylation of homocysteine to methionine. Due to insufficient conversion of homocysteine to methionine, plasma homocysteine levels increase in methylenetetrahydrofolate reductase deficiency. Homocysteine is an amino acid that contains a neurotoxic sulfur molecule and can induce neuronal apoptosis. Methylenetetrahydrofolate reductase deficiency is 1 of the etiological factors that causes neurological symptoms and signs in the newborn and childhood period. Here, we report a premature baby with prenatal onset diffuse multicystic encephalomalacia and cerebellar atrophy due to homozygous methylenetetrahydrofolate reductase mutation.

Lack of association between the G-2548A polymorphism of the leptin gene and psoriasis in a Turkish population

BACKGROUND

Psoriasis is a multifactorial disease in which genetic and inflammatory factors play important roles. Leptin is classified as a cytokine and plays an important role in the regulation of the T-helper response. A common polymorphism in the promoter of the human leptin gene (G-2548A) may have a role in the pathogenesis of psoriasis.

AIM

To investigate the association between psoriasis and leptin gene polymorphism (G-2548A).

METHODS

The study involved 109 patients with psoriasis and 125 healthy controls. Analyses of G-2548A polymorphism of the leptin gene were made by the polymerase chain reaction-restriction fragment length polymorphism technique. The genotypes (GG, GA, and AA of leptin gene G-2548A) and alleles (G and A) were scored and the frequencies were estimated. The frequencies of alleles and genotypes in patients and controls were compared. The relationship between leptin gene polymorphism and the clinical features of the patients was analyzed.

RESULTS

Both genotype [odds ratio (OR), 0.921; 95% confidence interval (CI), 0.501-1.694; P = 0.792] and allele (OR, 0.864; 95% CI, 0.600-1.242; P = 0.429) frequencies were not significantly different between patient and control groups. In addition, there was no significant association between genotype and allele frequencies and the clinical characteristics of psoriasis.

CONCLUSION

In this case-control study, no evidence of association between the G-2548A variant of the leptin gene and psoriasis was found.

Prostate-specific antigen and 17-hydroxylase polymorphic genotypes in patients with prostate cancer and benign prostatic hyperplasia

We investigated the association of prostate cancer (PCa) and benign prostatic hyperplasia (BPH) with genetic polymorphisms in prostate-specific antigen (PSA) (-158 G/A) and 17-hydroxylase (CYP17) (-34 T/C) genes in a Turkish population. In this study, we investigated the distribution of these polymorphisms in 148 PCa patients, 136 BPH patients, and 102 healthy individuals as controls. The polymorphisms were analyzed using polymerase chain reaction-restriction fragment length polymorphism assay. Genotype and allele frequencies were calculated, and their associations with PCa or BPH risk are assayed. The frequency of PSA gene GA and GG genotypes was significantly higher in PCa patients than in controls (p = 0.017 and p = 0.019, respectively). GG genotype was also associated with BPH (p = 0.033). In a case analysis, according to Gleason score, the association of PSA gene GG genotype with Gleason score >7 was near to statistical significance (odds ratio, 2.94; 95% confidence interval, 0.95-9.28). There was also an association between CYP17 polymorphism and BPH (p = 0.004). No association was observed between PCa and CYP17 gene polymorphism. These data demonstrate that PSA gene promoter variation may play a significant role in the development of PCa and BPH, and that CYP17 gene polymorphism may be associated with BPH in the Turkish population studied.

Analysis of vitamin D receptor gene polymorphisms in patients with chronic periodontitis

BACKGROUND & OBJECTIVE

Genetic polymorphisms in the vitamin D receptor (VDR) gene are related to bone mineral density, bone turnover, and diseases with bone loss. Alveolar bone loss is a key feature in periodontitis. The aim of this study was to determine whether severe generalized chronic periodontitis (CP) in a Turkish population was associated with polymorphisms in the VDR gene.

METHODS

Samples of venous blood and DNA were obtained from 72 patients with severe generalized chronic periodontitis and 102 healthy controls. The polymorphic regions were amplified using PCR followed by digestion with restriction enzymes BsmI A/G(rs1544410), ApaI G/T(rs11168271), TaqI T/C(rs731236), and analyzed electrophoretically. Genotype and allele frequencies were calculated.

RESULTS

There were no statistically significant differences in the frequencies of VDR BsmI, ApaI, TaqI genotypes between the CP patients and healthy controls. The GTT haplotype, constructed from the three adjacent restriction fragment length polymorphisms was found to be over-represented among CP cases. This corresponded an OR of 2.4 (95% confidence interval, 1.12-5.18) for heterozygous carriers and 2.27 (95% confidence interval, 0.95-5.4) for homozygous carrier of the risk haplotype.

INTERPRETATION & CONCLUSION

The present findings indicated that BsmI, ApaI, TaqI polymorphisms of the VDR gene were not associated with the severe generalized CP in the studied Turkish patients. Moreover, the VDR genotypes based on haplotype analysis may be associated with chronic periodontitis. In the future, diagnostic periodontal risk assessments like polymorphisms may be useful in detection of individuals susceptible for periodontitis.

MEFV mutations in patients with familial Mediterranean fever in the Black Sea region of Turkey: Samsun experience [corrected]

OBJECTIVE

To investigate MEFV mutations among patients with familial Mediterranean fever (FMF), their relatives, and healthy controls in the Black Sea region of Turkey; to compare 3 different MEFV mutation analysis methods; to evaluate the role of MEFV mutations in the diagnosis of FMF; and to investigate the role of M694V in the development of amyloidosis.

METHODS

In total, 890 subjects (625 patients, 165 relatives, 100 healthy controls) were included in this prospective study. MEFV mutations were studied with the amplification refractory mutation system (ARMS; n = 335), polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP; n = 335), and reverse hybridization assay (FMF StripAssay; n = 693).

RESULTS

All methods were used in 79 patients. The ratio of false negativity was about 2% using ARMS compared to PCR-RFLP. The FMF StripAssay was used to investigate 9 more mutations and detected 17 mutations in 14 patients. The M694V/M694V genotype was more common in patients with amyloidosis (37%) compared to patients without amyloidosis (18%) (p = 0.009). The frequency of MEFV carriers was 27%. The frequency of individuals having 2 mutations among asymptomatic relatives of FMF patients was 6%.

CONCLUSION

The FMF StripAssay is a reliable and time-saving method. In spite of detection of new mutations and developments in MEFV assay technology, there were patients in whom no mutation was detected. Our data, combined with previous studies, show that patients having M694V/M694V carry a risk for amyloidosis.

Association of the polymorphisms in promoter and intron regions of the interleukin-4 gene with chronic periodontitis in a Turkish population

OBJECTIVES

The etiology of periodontitis is related to the interaction between micro-organisms and host responses. Host modifying factors, such as genetic predisposition, may increase the severity of periodontitis. Recent works have shown that the levels of cytokine expression are regulated by genetic polymorphisms, and that these variations can interfere with progression of the disease. This study therefore aimed to evaluate whether interleukin (IL) 4 gene polymorphisms are associated with severe generalized chronic periodontitis.

MATERIAL AND METHODS

Seventy-five severe generalized chronic periodontitis patients and 73 healthy subjects were examined. Blood samples were taken and genomic DNA was amplified by polymerase chain reaction (PCR). Identification of 70 base-pair repeat polymorphisms in intron 2 and C-->T polymorphisms at -590 position of the promoter region was performed through PCR-restriction fragment length polymorphism (RFLP).

RESULTS

No significant differences were found in the allele and genotype frequencies between the control and periodontitis group.

CONCLUSION

The IL-4 polymorphisms were not related to severe generalized chronic periodontitis in a Turkish population.

Association of Serotonin 2A Receptor and Lack of Association of CYP1A2 Gene Polymorphism with Tardive Dyskinesia in a Turkish Population

The aim of this study was to investigate the possible association of serotonin 2A receptor gene (HTR2A) -1438 G/A polymorphism and CYP1A2 gene 163C/A polymorphism with tardive dyskinesia (TD) in a Turkish population. A total of 47 patients with persistent TD, 80 patients who were consistently without TD, and 100 healthy controls were included in this study. The polymorphic regions of -1438 G/A polymorphism of HTR2A receptor gene (rs6311) and 163C/A of CYP1A2 (rs762551) gene were amplified using polymerase chain reaction (PCR), followed by digestion with restriction enzymes MspI and Bsp1201. Genotype and allele frequencies were calculated by the chi(2)-test. Crude and adjusted odds ratios (ORs) were estimated, and 95% confidence intervals (CIs) were computed by multivariate logistic regression analysis. The genotype and allele frequencies of HTR2A and CYP1A2 gene were similar in schizophrenia with TD, schizophrenia without TD, and healthy controls. The logistic regression analysis showed that cumulative exposure to antipsychotic drugs for every year (p = 0.003; OR = 1.15; CI = 1.07-1.23), and AA genotype of HTR2A gene (p = 0.0258; OR = 4.34; CI = 1.19-15.81) are risk factors for TD. The same logistic regression model showed no association between CYP1A2 polymorphism and TD. The results of the present study seem to indicate that HTR2A gene polymorphism influences the tendency to express TD following prolonged antipsychotic drug exposure in Turkish schizophrenia patients.

Association of interleukin-10 gene polymorphisms with severe generalized chronic periodontitis

BACKGROUND

Interleukin-10 (IL-10), an anti-inflammatory cytokine, plays a role in periodontal disease by inhibiting synthesis of proinflammatory cytokines and stimulating protective antibody production. Genetic polymorphisms in the IL-10 gene might be useful as a marker to diagnose susceptibility to periodontitis. Therefore, the aim of this study was to investigate the association between IL-10 gene polymorphisms and severe generalized chronic periodontitis (CP) in a Turkish population.

METHODS

Samples of venous blood and DNA were obtained from 75 patients with severe generalized CP and 73 healthy subjects. The IL-10 promoter sequences at positions -597 and -824 were amplified by polymerase chain reaction, and polymorphisms were detected by restriction enzyme cleavage. Genotype and allele frequencies were calculated, and data were analyzed using the chi(2) test.

RESULTS

There was a statistically significant difference in frequencies of genotypes (AA/CC + CA: P = 0.00007, odds ratio = 12.37, 95% confidence intervals = 2.74 to 7.77; CC/CA + AA: P = 0.001, odds ratio = 3.05, 95% confidence intervals = 1.47 to 6.33) and alleles (P = 0.0002, odds ratio = 2.61, 95% confidence intervals = 1.52 to 4.51) at position -597 C to A between patients with severe generalized CP and healthy controls, whereas there was no significant difference in genotypes and allele frequencies at position -824 C to T between patients with CP and healthy subjects.

CONCLUSION

Within the limitations of sample selection and number, the IL-10 gene polymorphism at position -597 seems to be associated with severe generalized CP.

Lack of association between leptin G2548A gene polymorphism and Behçet's disease

BACKGROUND

Behçet's disease is a chronic, multisystem, inflammatory disease characterized by the predominance of T-helper 1 cytokines. The disease is also characterized by infiltration of lymphocytes and neutrophils into the affected tissues. Because cytokines are involved in the regulation of lymphocyte and phagocyte functions, they may play an important role in the pathogenesis of Behçet's disease. Leptin, a member of the gp 130 family of cytokines, induces a strong T-helper 1 response and is regarded as a proinflammatory inducer. Recent studies have shown that serum leptin concentration was increased in patients with Behçet's disease and correlated with disease activity.

OBJECTIVES

We aimed to investigate the role of G2548A polymorphism of leptin gene in patients with Behçet's disease and compare the results with healthy controls.

PATIENTS AND METHODS

A total of 93 subjects with Behçet's disease and 125 healthy controls were included in this study. Analyses of G-2548A polymorphism of the LEP gene were performed using the PCR-restriction fragment length polymorphism technique. The genotypes (GG, GA, and AA of leptin G2548A) and alleles (G and A of leptin 2548) were scored and the frequency was estimated. The frequencies of the alleles and genotypes in patients and controls were compared. We analysed the correlation between leptin gene polymorphism and the clinical features of BD.

RESULTS

Both genotype and allele frequencies were not significantly different between controls and Behçet's disease patients [OR=0.67, 95% CI (0.35-1.29), P=0.197 and OR=0.77, 95% CI (0.52-1.15), P=0.184]. We did not find any significant relationship between leptin gene polymorphism and the clinical features of BD (P>0.05).

CONCLUSION

In the present case-control study, we found no evidence of an association between the G-2548A variant of the leptin gene and BD among Turks. Further studies are needed to investigate serum leptin level to explain the mechanisms behind the lack of association between leptin G2548A gene polymorphism and BD.

Association of Matrix Metalloproteinase-9 Promoter Gene Polymorphism With Chronic Periodontitis

BACKGROUND

Matrix metalloproteinases (MMPs) are related to tissue destruction and remodeling events in periodontal diseases. A single nucleotide polymorphism in the promoter region of human MMP-9 gene is associated with the risk of some inflammatory diseases. Therefore, the aim of this study was to investigate the association between MMP-9 promoter polymorphism and severe generalized chronic periodontitis in a Turkish population.

METHODS

Samples of venous blood and DNA were obtained from 70 severe generalized chronic periodontitis patients and 70 healthy subjects. The alleles of the C/T polymorphism at position -1562 in the promoter region of the MMP-9 gene were distinguished by cutting with the SphI restriction enzyme. Genotype and allele frequencies were calculated, and data were analyzed by the chi2 test.

RESULTS

There was a significant difference in MMP-9 genotypes between chronic periodontitis patients and healthy controls. The odds ratios for the CT genotype and the combination of CT and TT genotypes were 0.4 (95% confidence interval, 0.17 to 0.93; P=0.02) and 0.37 (95% confidence interval, 016 to 0.85; P=0.01) relative to the subjects with the CC genotype, respectively.

CONCLUSION

MMP-9 promoter gene polymorphism seems to be associated with severe generalized chronic periodontitis.

Polymorphisms of CYP1A1, GSTM1, GSTT1, and prostate cancer risk in Turkish population

Prostate cancer is the most common cancer among men in many countries. Although the etiology of prostate cancer largely is unknown, both genetic and environmental factors may be involved. Advanced age, androgen metabolism, and heredity-race have been reported to be possible risk factors. On the other hand, several studies indicate that genetic polymorphisms in biotransformation enzymes play a role in prostate cancer development. In this study, association of the prostate cancer risk with genotype frequencies of the Phase I (CYP1A1) and Phase II (GSTM1 and GSTT1) biotransformation enzymes was investigated in 321 Turkish individuals (152 prostate cancer patients and 169 age-matched male controls). The presence or absences of the GSTM1 and GSTT1 genes were determined by a PCR-based method. Genotypes of CYP1A1 were determined by MspI-RFLP. The prevalence of GSTM1 null genotype in the cases was 64 percent, compared to 31 percent in the control group, indicating a strong association (OR = 4.08, 95%CI = 2.50-6.69). No association was observed between either GSTT1 null genotype or CYP1A1 polymorphism and prostate cancer incidence. No statistically significant association was observed between smoking status of the patients and any of the polymorphisms studied. In conclusion, results of this study indicate that only the GSTM1 null genotype may play an important role as a risk factor for prostate cancer development in Turkish population.

Lack of evidence for association between endothelial nitric oxide synthase gene polymorphism (glu298asp) with Behçet’s disease in the Turkish population

Endothelial nitric oxide synthase (eNOS) could be a candidate gene for Behçet's disease (BD). This study investigated the relationship of the eNOS Glu298 --> Asp polymorphism with the presence and severity of BD in the Turkish population. Ninety-two patients with BD and 100 controls were studied. Analyses of Glu298Asp polymorphism in exon 7 of the eNOS gene were made by the polymerase chain reaction (PCR)-restriction fragment length polymorphism technique. The frequencies of the eNOS genotypes were similar for BD patients (GG:GT:TT = 58.7%:38%:3.3%) and controls (59.2%:33.7%:7.1 %), P = 0.335. No evidence of difference was found in the frequency of the T allele between BD patients (22.3%) and controls (24%), [OR = 0.91, 95% CI (0.55-1.50), P = 0.690]. Glu298 --> Asp polymorphism of the eNOS gene does not appear to be associated with the presence of BD in the Turkish population.

Vitamin D receptor gene polymorphisms in patients with urolithiasis

Urolithiasis is a multifactorial disease, the onset and severity of which is influenced by both genetic and environmental factors. This study represents an investigation of the role of vitamin D receptor (VDR) gene polymorphisms (ApaI, BsmI, and TaqI) and combined genotypes in urolithiasis in a Turkish population. We studied 110 patients with urinary stones and 150 control subjects. The polymorphic regions were amplified using polymerase chain reaction, followed by digestion with restriction enzymes BsmI, ApaI, and TaqI, and analyzed electrophoretically. Genotype and allele frequencies were calculated, and the association with urolithiasis, family history, and recurrence of stone was investigated. Our data provide no evidence for an association between urolithiasis and VDR ApaI, BsmI, and TaqI genotypes. We also analyzed the effects of VDR ApaI, BsmI, and TaqI genotypes in combination; the "GTT" VDR haplotype, constructed from three adjacent restriction fragment length polymorphisms was overrepresented among the urolithiasis patients. However, no significant differences between heterozygous carriers (OR 1.302; 95% CI 0.527-3.215) and homozygous carriers (OR 3.39; 95% CI 0.719-15.985) were observed in our study population. A significant association was found only between the ApaI polymorphism and family history (P=0.017; chi (2)=5.657). Our data indicate that the VDR ApaI, BsmI, and TaqI polymorphisms do not confer a significant risk for urolithiasis.

Nucleotide changes in the gamma-globin promoter and the (AT)xNy(AT)z polymorphic sequence of beta LCRHS-2 region associated with altered levels of HbF

We have studied 31 beta-thalassaemia intermedia, 30 beta-thalassaemia major patients and 50 normal individuals from Turkey, determining the relationship between the nucleotide variations in beta-globin gene cluster, the altered levels of foetal haemoglobin and the relative ratios of beta- and gamma mRNAs. We have found in beta-thalassaemia intermedia patients with high foetal haemoglobin expression that the three nucleotide variations in the 5' sequences of the gamma globin genes, A-->G at G gamma - 1396, the T-->C at A gamma - 228, and the GA-->AG at A gamma - 603/4, are linked to haplotype II in haplotypic homozygotes and the (AT)8N14(AT)7 motif in beta LCR. Conversely, the three single nucleotide substitutions in the 5' sequences of gamma globin genes, the G-->A at G gamma - 1225, the A-->G at A gamma + 25 and the C-->G at A gamma - 369, which have a strong linkage with haplotype I, V or VI in haplotypic homozygotes and the (AT)10N12(AT)12 and the (AT)9N12(AT)12 motifs in HS-2 of beta LCR are all associated with low foetal haemoglobin levels. The number of nucleotide changes in beta-globin gene cluster implied in our study are not the primary cause of the differences in haemoglobin F levels. They perhaps may contribute to the variations in the clinical severity observed among beta thalassaemia intermedia and major patients with other yet unknown gene conversions.

Germline hMSH2 and hMLH1 gene mutations in incomplete HNPCC families

Hereditary non-polyposis colon cancer (HNPCC) is a common hereditary disease characterized by a predisposition to an early onset of colorectal cancer. The majority of the HNPCC families carry germline mutations of either hMSH2 or hMLH1 genes, whereas germline mutations of hPMS1 and hPMS2 genes have rarely been observed. Almost all of the germline mutations reported so far concern typical HNPCC families. However, there are families that display aggregations of colon cancer even though they do not fulfil all HNPCC criteria (incomplete HNPCC families) as well as sporadic cases of early onset colon cancers that could be related to germline mutations of these genes. Therefore, we screened germline mutations of hMSH2 and hMLH1 genes in 3 groups of patients from France and Turkey: typical HNPCC (n = 3), incomplete HNPCC (n = 9) and young patients without apparent familial history (n = 7). By in vitro synthesis of protein assay, heteroduplex analysis and direct genomic sequencing, we identified 1 family with hMSH2 mutation and 5 families with hMLH1 mutations. Two of the 3 HNPCC families (66%) displayed hMLH1 germline mutations. Interestingly, 4 of 9 families with incomplete HNPCC (44%) also displayed mutations of hMSH2 or hMLH1 genes. In contrast, no germline mutation of these genes was found in 7 young patients. Our results show that germline mutations of hMSH2 and hMLH1 genes contribute to a significant fraction of familial predisposition to colon cancer cases that do not fulfil all diagnostic criteria of HNPCC.

Inhibition of calpain by a synthetic oligopeptide corresponding to an exon of the human calpastatin gene

Calpastatin is a widely distributed endogenous inhibitor protein specifically acting on calpain (Ca2+-dependent cysteine endopeptidase). The inhibitor consists of four inhibitory domains (Domains 1-4) with mutually homologous sequences. NH2-terminal Domain L is non-homologous, and all domains have 120-140 residues each. A human calpastatin genomic DNA clone was isolated using a previously obtained human calpastatin cDNA probe. Sequence analysis has revealed that the clone contains Domain 1 and segments of neighboring domains (Domains L and 2). Each of three highly conserved, restricted regions within Domain 1 was located on separate exons, 1A, 1B, and 1C. Exon 2A, corresponding to the first exon of Domain 2, is homologous to Exon 1A and follows Exon 1D of Domain 1. A 27-residue peptide encoded by Exon 1B, including a 12-residue middle conserved sequence, was chemically synthesized and tested for protease inhibitory activities. The synthetic peptide showed strong inhibition against calpain I (low Ca2+-requiring form), and calpain II (high Ca2+-requiring form), but no inhibition against papain or trypsin. These results indicated that Exon 1B forms a self-sufficient functional subdomain of the calpastatin inhibitory domain.

Repair of methyl methane sulfonate-damaged phage by Haemophilus influenzae

Seven mutants of Haemophilus influenzae strain Rd (mmsA-) have been isolated that are more sensitive to methyl methane sulfonate (mms) than recombination-deficient (recA-) mutants. The mutations cotransformed about 25% with the strA locus while the five studied clustered tightly; they are all probably allelic. The mutants are not sensitive to ultraviolet radiation, X-rays, or nitrous acid. Mms-damaged phage HP1 plated very inefficiently on these mutants, indicating that they lack the first step in the excision repair of the lesion N3-methyladenine (m3A). Incubation of damaged phage at 30 degrees C in the absence of mms resulted in a steady decline of viability when the phage were plated on the wild mmsA+ host but an initial steep rise was seen when it was plated on an mmsA- mutant. The rise is explained by the assumption that m3A lesions hydrolyzed off the DNA giving rise to repairable apurinic sites by both the mmsA+ and mmsA- hosts. No decline in viability was observed when hydroxylamine was present in the medium. This compound is known to prevent or slow down beta-elimination. The delayed decline in viability is therefore explained by assuming that apurinic sites give rise to beta-elimination-induced single strand breaks in the phage DNA that cannot be repaired by either host. Marker rescue experiments indicated that these breaks did not interrupt injection of phage DNA.

Bromouracil-induced mutagenesis in a mismatch-repair-deficient strain of Haemophilus influenzae

Cells of wild-type Haemophilus influenzae and of a mismatch-repair-deficient mutant (hex-) were grown in a chemically defined medium containing either thymidine or 5-bromodeoxyuridine (BUdR). Spontaneous mutation frequencies to resistance against 3 antibiotics observed for the thymidine cultures were 10-30 times higher for the hex- mutant. The mutation frequencies observed for the BUdR hex- culture were increased by another 10 times while those for the wild-type suspension did not differ from the frequencies seen in the thymidine medium.

A hex mutant of Haemophilus influenzae

A mutant of Haemophilus influenzae which does not discriminate between low efficiency (LE) and high efficiency (HE) markers has been isolated. The mutant does not differ wild type in its sensitivity to ultraviolet radiation, methyl methanesulfonate (MMS) mitomycin C, and nitrous acid. Spontaneous mutation frequencies for three loci studied are 10- to 30-fold higher in the mutant than in the wild type strain. Low- and high-efficiency transforming markers are equally UV-resistant when assayed on this mutant. This mutant is thus similar to the hex mutant of Streptococcus pneumoniae.