Mitochondrial Common Deletion Level in Adipose Tissue Is Not Associated with Obesity but Is Associated with a Structural Change in Triglycerides as Revealed by FTIR Spectroscopy

OBJECTIVE

Several studies have shown that mitochondrial metabolism may be disrupted if the rate of the specific 4,977 bp deletion of mitochondrial DNA (mtDNA) reaches a threshold. This study aimed to investigate the possible associations between the mtDNA4977 deletion load and obesity-related metabolic abnormalities in the adipose tissue.

METHODS

The study included thirty obese individuals, who underwent bariatric surgery, and twelve control subjects. mtDNA4977 deletion, adenine nucleotides, and lactate levels, which show the bioenergetic status were evaluated in visceral adipose tissues. Fourier transform infrared (FTIR) spectroscopy was used to investigate the structural variations and composition of adipose tissues in the context of deletion load.

RESULTS

There were no differences between the two groups in terms of mtDNA4977 deletion, adenine nucleotides, and lactate levels. The FTIR spectra indicated a few obesity-related alterations in adipose tissues that were not related to the mtDNA deletion load. Also, statistical analysis showed a correlation between the deletion load and a band shift of 1,744 cm-1, which assigns C = O stretching of the carbonyl group of the ester group in triglycerides and other esterified fatty acids, although it is not associated with obesity.

CONCLUSIONS

Our data suggest that the mtDNA4977 deletion in visceral adipose tissues of obese individuals do not have a significant impact on the bioenergetic status. However, the increased accumulation of deletion may be associated with a specific change in the ester bond, indicating structural differences in the lipids. These findings shed light on our understanding of the tissue-specific distribution of mtDNA deletions and obesity-related adipose tissue pathogeneses.

Combined resveratrol and vitamin D treatment ameliorate inflammation-related liver fibrosis, ER stress, and apoptosis in a high-fructose diet/streptozotocin-induced T2DM model

A high fructose diet is a major cause of diabetes and various metabolic disorders, including fatty liver. In this study, we investigated the effects of resveratrol and vitamin D (VitD) treatments on endoplasmic reticulum (ER) stress, oxidative stress, inflammation, apoptosis, and liver regeneration in a rat model of type 2 diabetes mellitus, namely, T2DM Sprague-Dawley rats. This T2DM rat model was created through a combination treatment of a 10% fructose diet and 40 mg/kg streptozotocin (STZ). Resveratrol (1 mg/kg/day) and VitD (170/IU/week) were administered alone and in combination to both the diabetic and control groups. Immunohistochemical staining was performed to evaluate PCNA, NF-κB, TNF-α, IL-6, IL-1β, GRP78, and active caspase-3 in liver tissue. The TUNEL method and Sirius red staining were used to determine apoptosis and fibrosis, respectively. G6PD, 6-PGD, GR, and GST activities were measured to determine oxidative stress status. We found that the expressions of cytokines (TNF-α, IL-6, and IL-1β) correlated with NF-κB activation and were significantly increased in the T2DM rats. Increased GRP78 expression, indicating ER stress, increased in apoptotic cells, enhanced caspase-3 activation, and collagen accumulation surrounding the central vein were observed in the T2DM group compared with the other groups. The combination VitD + resveratrol treatment improved antioxidant defense via increasing G6PD, 6-PGD, GR, and GST activities compared to the diabetic groups. We concluded that the combined administration of resveratrol with VitD ameliorates the adverse effects of T2DM by regulating blood glucose levels, increasing antioxidant defense mechanisms, controlling ER stress, enhancing tissue regeneration, improving inflammation, and reducing apoptosis in liver cells. In conclusion, this study indicates that the combination treatment of resveratrol + VitD can be a beneficial option for preventing liver damage in fructose-induced T2DM.

Topical application of metformin accelerates cutaneous wound healing in streptozotocin-induced diabetic rats

BACKGROUND

Diabetic chronic wound, which is one of the diabetic complications caused by hyperglycemia, characterized by prolonged inflammation has become one of the most serious challenges in the clinic. Hyperglycemia during diabetes not only causes prolonged inflammation and delayed wound healing but also modulates the activation of nuclear factor-kappa B (NF-κB) and the expression of matrix metalloproteinases (MMPs). Although metformin is the oldest oral antihyperglycemic drug commonly used for treating type 2 diabetes, few studies have explored the molecular mechanism of its topical effect on wound healing. Therefore, we aimed to investigate the molecular effects of topical metformin application on delayed wound healing, which's common in diabetes.

METHODS AND RESULTS

In this context, we created a full-thickness excisional wound model in Wistar albino rats and, investigated NF-κB p65 DNA-binding activity and expression levels of RELA (p65), MMP2 and MMP9 in wound samples taken on days 0, 3, 7, and 14 from diabetic/non-diabetic rats treated with metformin and saline. As a result of our study, we showed that topically applied metformin accelerates wound healing by suppressing NF-κB p65 activity and diminishing the expression of MMP2 and MMP9.

CONCLUSIONS

Diabetic wounds treated with metformin healed even faster than those in the control group that mimicked standard wound healing.

Effect of vitamin D supplementation on OPG/RANKL signalling activities in endothelial tissue damage in diet-induced diabetic rat model

BACKGROUND

Type 2 Diabetes Mellitus is a chronic metabolic disease that causes endothelial damage and is an important risk factor for atherosclerosis. In the present study vitamin D3 supplementation in rats was used to determine the role of Osteoprotegerin (OPG)/Receptor activator kB ligand (RANKL) signalling in endothelial damage and changes in the expression levels of genes involved in this pathway. We hypothesized that vitamin D3 supplementation affects OPG and RANKL activity in the aorta.

METHODS

Diabetes was induced in rats via injections of 40 mg/kg of streptozotocin followed by a high fructose (10%) diet. Group 2 (healthy) and 4 (diabetic) received 170 IU/kg of vitamin D3 weekly for 5 weeks, while Group 1 (healthy) and 2 (diabetic) received sterile saline. The aortas of each group were collected to analyse mRNA expression using the real-time PCR method and also to evaluate magnesium and calcium levels using inductively coupled plasma mass spectrometry.

RESULTS

Opg and Il-1b expression levels were significantly associated with both diabetes and vitamin D3 supplementation in the aortas of the study groups (p ≤ 0.05). Opg mRNA expression was also found to correlate with both Icam-1 and Nos3 mRNA expression levels (r = 0.699, p = 0.001 and r = 0.622, p = 0.003, respectively). In addition, when mineral levels in the aortic tissues were compared among all groups, it was found that the interaction of diabetes and vitamin D3 supplementation significantly affected Mg levels and Mg/Ca ratios.

CONCLUSIONS

It is concluded that vitamin D3 supplementation has a modulatory effect on OPG/RANKL activity in the vessel wall by ameliorating endothelial damage in diabetes. This effect may contribute to the regulation of cytokine-mediated vascular homeostasis and mineral deposition in the aorta; therefore, further comprehensive studies are proposed to demonstrate this relationship.

Altered Transcriptional Profile of Mitochondrial DNA-Encoded OXPHOS Subunits, Mitochondria Quality Control Genes, and Intracellular ATP Levels in Blood Samples of Patients with Parkinson's Disease

Mitochondrial dysfunctions are significant contributors to neurodegeneration. One result or a cause of mitochondrial dysfunction might be the disruption of mtDNA transcription. Limited data indicated an altered expression of mtDNA encoded transcripts in Alzheimer's disease (AD) or Parkinson's disease (PD). The number of mitochondria is high in cells with a high energy demand, such as muscle or nerve cells. AD or PD involves increased risk of cardiomyopathy, suggesting that mitochondrial dysfunction might be systemic. If it is systemic, we should observe it in different cell types. Given that, we wanted to investigate any disruption in the regulation of mtDNA encoded gene expression in addition to PINK1, PARKIN, and ATP levels in peripheral blood samples of PD cases who are affected by a neurodegenerative disorder that is very well known by its mitochondrial aspects. Our results showed for the first time that: 1) age of onset > 50 PD sporadic (PDS) cases: mtDNA transcription and quality control genes were affected; 2) age of onset <50 PDS cases: only mtDNA transcription was affected; and 3) PD cases with familial background: only quality control genes were affected. mtDNA copy number was not a confounder. Intracellular ATP levels of PD case subgroups were significantly higher than those of healthy subjects. We suggest that a systemic dysregulation of transcription of mtDNA or mitochondrial quality control genes might result in the development of a sporadic form of the disease. Additionally, ATP elevation might be an independent compensatory and response mechanism. Hyperactive cells in AD and PD require further investigation.

Anti-cancer effect of metformin on the metastasis and invasion of primary breast cancer cells through mediating NF-kB activity

Current evidence strongly suggests that aberrant activation of the nuclear factor kappa B (NF-kB) signaling cascade is connected to carcinogenesis. The matrix metalloproteinases (MMP) which are also the key agents for tumor metastasis may be potent candidates for tumor diagnosis in clinics. In this in vitro study, we hypothesized that metformin with an effective dose can inhibit tumor cell proliferation and metastasis by modulating the expressions of MMP-2 and -9 and interfering with NF-kB signaling in primary breast cancer cells (PBCCs). 300 000 cells per ml were obtained from biopsies of breast tumors from five human donors. The cell viability and proliferation were tested. Immunocytochemistry was performed for MMP-2, MMP-9, and NF-kB, and enzyme-linked immunosorbent assay for NF-kB activity, quantitative real-time PCR for RELA/p65, IkBα, MMP-2, and MMP-9. Three different doses of metformin (5, 10, and 25 mM) (Met) reduced the viability and proliferation of PBCCs in a dose-dependent manner, maximum inhibition was observed at 25 mM Met. The expression of RELA/p65 was not affected by 25 mM Met. Nuclear immunoreactivity and activity of NF-kB reduced while cytoplasmic NF-kB (p65) elevated by 25 mM Met compared to non-treatment (P <  0.05). The expression and immunoreactivity of MMP-9 but not MMP-2 were decreased by 25 mM Met treatment, compared with the non-treatment (P <  0.05). Metformin may have an essential antitumor role in the invasion and metastasis pathways of PBCCs by downregulating the MMP-9 expression blocking both the activity and nuclear translocation of NF-kB.

Variations in Toll-like receptor and nuclear factor-kappa B genes and the risk of glioma

PURPOSE

Glioblastoma (GBM) is the most aggressive primary brain tumour in the adult nervous system and is associated with a poor prognosis. NF-KB activation is an important driver of the malignant phenotype that confers a negative prognosis in patients with GBM. NF-KB plays a role in Toll-like Receptors (TLR)-induced tumourigenesis. The aim of the present study was to investigate the association of a promoter region polymorphism of NFKB1 gene encoding the p50 subunit of NF-KB, namely -94ins/del ATTG, the most widely discussed the TLR2 Arg753Gln, TLR4Asp299Gly and TLR4Thr399Ile polymorphisms, their combined effects, and the glioma risk.

METHODS

A group of 120 Glioma patients and 225 control subjects were screened for these four polymorphisms using the PCR-RFLP method.

RESULTS

Statistical analysis indicates that the ins/ins genotype of NFKB -94ins/delATTG (p=0.003), and the AA genotype of TLR4Asp299Gly (p < 0.001) are risk factors for glioma and people carrying the ins allele have an approximately 1.47 times susceptibility risk of glioma whereas GG genotype of TLR2Arg753Gln seems to be protective against glioma (p = 0.002). Combined genotype analysis showed that del/ins-GG genotype of TLR2Arg753Gln-NFKB1, del/ins + GG genotype of TLR4Asp299Gly-NFKB1, del/ins-CC genotype of TLR4Thr399Ile-NFKB1 were risk factors for glioma development.

CONCLUSION

NFKB1 -94ins/delATTG and TLR4Asp299Gly polymorphisms are associated with increased glioma cancer risk in a Turkish population.

Increased mitochondrial common deletion in platelets from patients with type 2 diabetes is not associated with abnormal platelet activity or mitochondrial function

The present study examined the presence and frequency of the 4,977‑base pair mitochondrial (mt)DNA (mtDNA4977) deletion in blood platelets, and whether increased mtDNA4977 deletion was associated with abnormal mitochondrial and platelet function in type 2 diabetes mellitus. A total of 66 patients with type 2 diabetes mellitus and 23 healthy subjects were included in the present study. Patients were divided into three subgroups according to glycemic control, and the presence or absence of chronic diabetic complications: i) Good glycemic control [glycated hemoglobin (HbA1c) <7] without complications; ii) poor glycemic control (HbA1c ≥7) without complications; and iii) poor glycemic control (HbA1c ≥7) with complications. mtDNA4977 deletion, mtDNA copy number, adenine nucleotides, mitochondrial membrane potential and P‑selectin expression levels were analyzed in platelets. Although the frequency of mtDNA4977 deletion in platelets of the patient (96.9%) and control groups (95.6%) was extremely similar, the deletion level significantly increased in all the diabetic groups, compared with the healthy control group. However, the data from the present study revealed that an increased deletion frequency in platelets was not associated with disease severity, although there was clear interindividual variability. Furthermore, all other parameters were not significantly different among the groups, and there were no correlations between mtDNA4977 deletion frequency and all other studied parameters for any of the case groups. The results indicated that the mtDNA4977 deletion occurred in platelets, and increased deletion in patients with type 2 diabetes did not have a marked influence on mitochondrial and/or platelet dysfunction, when compared with the non‑diabetic subjects. Further research is required to elucidate the sources of inter‑individual variability observed in certain parameters.

Investigation of the SLC22A23 gene in laryngeal squamous cell carcinoma

Background

Laryngeal squamous cell carcinoma (LSCC) is the second most common cancer of the head and neck. In order to identify differentially expressed genes which may have a role in LSCC carcinogenesis, we performed GeneFishing Assay. One of the differentially expressed genes was the SLC22A23 (solute carrier family 22, member 23) gene.

SLC22A23 belongs to a family of organic ion transporters that are responsible for the absorption or excretion of many drugs, xenobiotics and endogenous compounds in a variety of tissues. SLC22A23 is expressed in a various tissues but no substrates or functions have been identified for it. Although the exact function is unknown, single nucleotide polymorphisms (SNPs) which are located in SLC22A23 gene were associated with inflammatory bowel disease (IBD), endometriosis-related infertility and the clearance of antipsychotic drugs. On the other hand SLC22A23 is identified as a prognostic gene to predict the recurrence of triple-negative breast cancer.

Methods

To understand the role of the SLC22A23 gene in laryngeal carcinogenesis, we investigated its mRNA expression level in laryngeal tumor tissue and adjacent non-cancerous tissue samples obtained from 83 patients by quantitative real-time PCR. To understand the association between SNPs in SLC22A23 and LSCC, selected genetic variations (rs4959235, rs6923667, rs9503518) were genotyped.

Results

We found that SLC22A23 expression was increased in 46 of 83 tumor tissues (55.4%) and was decreased in 30 of 83 (36.1%) tumor tissues compared to normal tissues. 77.2% of patients were homozygote for genotype rs9503518-AA and they most frequently had histological grade 2 and 3 tumors. We also found that rs9503518-AA genotype is associated with increased SLC22A23 expression.

Conclusions

Our results indicate that SLC22A23 may play a role in the development of laryngeal cancer.

Relation of Biochemical Parameters with Flow-mediated Dilatation in Patients with Metabolic Syndrome

BACKGROUND

Metabolic syndrome (MetS) is one of the high cardiovascular (CV) situations. Endothelial dysfunction, which is a common finding in patients with MetS, is related with increased CV risk. In patients with MetS, the effect of the major CV risk factors, not included in the MetS definition, on endothelial dysfunction is not well known. The aim of this study was to determine the effect of major CV risk factors such as gender, smoking, family history, and biochemical parameters on endothelial dysfunction in patients with MetS.

METHODS

The study was performed between December 2010 and August 2014. A total of 55 patients (15 females and 40 males) with MetS and 81 healthy controls (37 females and 44 males) with a body mass index <25 kg/m2 were enrolled in the study. Endothelial dysfunction was measured by flow-mediated dilatation (FMD), oxidative stress parameters; high-sensitivity C-reactive protein (hs-CRP), oxidized low-density lipoprotein (ox-LDL), endothelial nitric oxide synthase (e-NOS), nitric oxide, and cell adhesion markers; von Willebrand factor, and e-selectin. Platelet aggregation (endothelial adenosine diphosphate), total platelet count, and mean platelet volume were additionally analyzed and demographic parameters were explored. Student's t- test, Mann-Whitney U-test, and Chi-square test were used to analyze the results.

RESULTS

The fasting blood glucose (z= 3.52, P= 0.001), hs-CRP (z = 3.23, P= 0.004), ox-LDL (z = 2.62, P= 0.013), and e-NOS (z = 2.22, P= 0.026) levels and cardiac risk score (z = 5.23, P< 0.001) were significantly higher in patients with MetS compared with the control group. Smoking was correlated with decreased FMD (χ2 = 9.26, P= 0.002) in MetS patients but not in the control group.

CONCLUSIONS

Increased ox-LDL, hs-CRP, and e-NOS are likely to be a result of oxidative stress, a condition in which an imbalance occurs between the production and inactivation of reactive nitrogen and oxygen species. In addition, in patients with MetS, smoking is independently related to endothelial dysfunction.

PRR4: A novel downregulated gene in laryngeal cancer

Head and neck squamous cell carcinomas (HNSCC) are a diverse group of tumor types, including neoplasia of the paranasal sinuses, oral cavity, trachea, pharynx and larynx. Laryngeal cancer is the most common type of HNSCC. The proline-rich 4 (PRR4) protein is synthesized in the acinar cells of human lacrimal glands. Previous studies have demonstrated that PRR4 may function as an antimicrobial protein protecting the ocular surface and the oral cavity. In order to determine differentially expressed genes (DEGs) in laryngeal tumors, a GeneFishing Assay was performed; 27 DEGs were identified. The PRR4 gene expression level in laryngeal tissue samples obtained from 90 patients, and the saliva of 25 healthy smokers and 25 non-smokers, was investigated using reverse transcription-quantitative polymerase chain reaction. It was revealed that PRR4 gene expression was decreased in 65/90 tumor tissues (72.2%) compared with normal tissues. No significant difference was identified between the healthy smoker and the non-smoker groups in terms of PRR4 gene expression. The results of the present study indicated that the PRR4 gene may serve an important role in laryngeal carcinogenesis.

Genetic variants rs1994016 and rs3825807 in ADAMTS7 affect its mRNA expression in atherosclerotic occlusive peripheral arterial disease

AIM

Peripheral artery disease (PAD) is a vascular disease affecting peripheral circulation. Recently, genome-wide association studies revealed a relationship between single nucleotide polymorphisms (SNPs) in ADAMTS7 (a disintegrin and metalloprotease with thrombospondin motif 7) and atherosclerosis. In this study, we aimed to determine ADAMTS7 expression in peripheral blood mononuclear cells (PBMCs) and the frequency of ADAMTS7 rs1994016 and rs3825807 polymorphisms in a sample of Turkish patients with PAD, and to evaluate the association of matrix metalloproteinase (MMP) levels with PAD development.

METHODS

In this case-control study, ADAMTS7mRNA and protein expression was determined using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and western blot, respectively, and rs1994016 and rs3825807 variants in ADAMTS7 were determined by real-time PCR in 115 PAD patients and 116 healthy controls. Plasma levels of nine MMPs were determined using a multiplex immunoassay system.

RESULTS

ADAMTS7mRNA levels were significantly higher in PAD patients than in controls (t=-2.75, P=.007). There was no significant difference in the frequencies of rs1994016 and rs3825807 between PAD patients and controls (P>.05). In PAD patients, ADAMTS7mRNA levels were significantly increased for the CC genotype of rs1994016 (t=-2.31, P=.026) and TT genotype of rs3825807 (t=-2.23, P=.032). Furthermore, plasma levels of MMP-1, MMP-3, MMP-7, MMP-10, MMP-12, and MMP-13 were significantly higher in PAD patients than in controls (P<.05).

CONCLUSION

This is the first report of the relationship between PAD and ADAMTS7 expression and the effects of the rs1994016 and rs3825807 variants on PAD development. ADAMTS7 may be associated with PAD development.

Endothelial Dysfunction Markers in Low Cardiovascular Risk Individuals: Comparison of Males and Females

BACKGROUND

Cardiovascular diseases (CVD) account for approximately 50% of the total deaths in Turkey. Most of them are related with atherosclerotic coronary heart disease. Predictive value of endothelial dysfunction markers related with the earliest stage of atherosclerosis has been getting more attention. We hypothesized that differences in endothelial dysfunction biochemical markers among genders would aid to capture proatherogenic activity that was not diagnosed by conventional risk assessment scoring systems.

METHODS

We assessed the endothelial dysfuntion markers in 92 Turkish adults who were in the »low CV risk group« according to ESC (European Society of Cardiology)-Score Risk Charts. We compared the males and females.

RESULTS

We observed higher endothelial dysfunction rates in males, with higher median and mean levels of e-NOS, ox-LDL before and after adjustment for HDL lowness and obesity (P=0.018, P=0.036 for NOS; P=0.000, P=0.004 for ox-LDL, respectively). Men had higher hs-CRP levels than females before adjustment (P=0.021). Decreased e-NOS levels were related with FMD for females before adjustment for confounders (P=0.028). We also found significant correlation between e-NOS and ox-LDL levels both before (r=0.360, P<0.001) and after adjustment (r=0.366, P<0.01) for confounders which pointed out the nitrosative stress. In multivariate regression analyses, after adjusting for other endothelial dysfunction markers which were not included in the ESC-risk scoring system, decreased e-NOS levels were independently asssociated with impaired flow mediated dilatation for females (odds ratio 0.3; P=0.038).

CONCLUSIONS

Our results underline the importance of gender in evaluating endothelial dysfunction biochemical markers to assess cardiovascular risk for low CV risk indivuals.

The Relationship of Various Factors in the Pathogenesis of Atherosclerosis

In this study we investigated the levels of lipid parameters, fibronectin, tissue-type plasminogen activator and plasminogen activator inhibitor (t-PA-PAI-1) complex and si alidase in patients with coronary heart disease and a control group. Total cholesterol, triglyceride, low-density lipoprotein (LDL), and very-low-density lipoprotein (VLDL) cholesterol and lipoprotein Lp(a), levels in patients with coronary heart disease were found to be significantly higher than in the control group (p < .001). High-density lipoprotein (HDL) cholesterol levels in patient group were significantly lower than control group (p < .001). Plasma fibronectin and t-PA-PAI-1 complex levels in patients with coronary heart disease were found to be significantly higher than control group (p < .05 and p < .001, respectively). In addition, we found that serum sialidase levels in patients with coronary heart disease were significantly higher than in the control group (p < .001). The electrophoretic mobility of lipoproteins from patients with coronary heart dis ease was found to be greater than those from the control group. As a result Lp(a) may play an important role in the pathogen esis of atherosclerosis by causing foam cell formation because of interacting with LDL or fibronectin and by interfering with the fibrinolytic system because of binding to plasminogen re ceptors. In addition, modifications of Lp(a) (including desi alylation) may effect these events. Key words: Coronary heart disease—tPA-PAI-1 complex-Fibronectin-sialidase-Lipid parameters.

Molecular Analysis of Factor V Leiden, Factor V Hong Kong, Factor II G20210A, Methylenetetrahydrofolate Reductase C677T, and A1298C Mutations Related to Turkish Thrombosis Patients

Inherited gene disorders related to the hemostatic system have been documented as risk factors for thrombosis. The roles of factor V Hong Kong (FV Hong Kong), factor V Leiden (FV Leiden), factor II G20210A (FII G20210A), methylenetetrahydrofolate reductase (MTHFR) C677T, and MTHFR A1298C mutations in Turkish patients with thrombosis (270 patients) compared with healthy controls (114 subjects) were evaluated. Polymerase chain reaction—based restriction enzyme analysis was carried out to screen these mutations, and single-strand conformation analysis was established to identify variations using the primers selected for restriction enzyme analysis studies. As a result, a significant relationship was determined among FV Leiden, FII G20210A, and thrombosis. The FV Hong Kong mutation was observed in only 2 patients with pulmonary vein thrombosis who are FV Leiden/FV Hong Kong compound heterozygous for FV gene. MTHFR C677T and A1298C were equally distributed in the patient group compared with the control group. All named mutations were also identified with single-strand conformation analysis, but a new variant/polymorphism during studies was not found. Because some inherited abnormalities are associated with thromboembolic disorders, determining the mutations and gene-to-gene interactions in patients with thrombosis history has a great impact on diagnosis and treatment of these diseases.

PCR-RFLP Detection of PAI-2 Variants in Myocardial Infarction

PAI-2 is one of the regulators of the fibrinolytic system. The importance of the fibrinolytic cascades in the pathogenesis of myocardial infarction has been demonstrated by many investigators. Recently, some investigators have shown that two variants of PAI-2, designated A and B, are associated with the formation of large molecular PAI-2 complexes. This polymorphism is therefore present a genetic predisposition for the development of coronary artery disease and multiple sclerosis. Therefore, the prevalence of this polymorphism among 45 patients with MI and 20 control subjects was investigated. The AA genotype of the PAI-2 gene was found to be more frequent among those subjects with MI. These data provide evidence that a polymorphism of the PAI-2 gene is associated with an increased risk of MI.

CT120A Acts as an Oncogene in Head and Neck Squamous Cell Carcinoma

Squamous cell carcinoma of the head and neck (HNSCC) is among the most frequent cancers worldwide. The etiology and pathogenesis of HNSCC are influenced by multiple genetic factors in addition to environmental and lifestyle-related factors. However, the mechanism underlying the HNSCC is still far from clear.

The membrane associated gene CT120 was previously identified from chromosome 17p13.3 as a lung cancer-associated gene. Its function as an activator of the Erk and Akt signaling pathways in human lung cancer cell lines suggested that CT120 has an oncogenic function. However, there is no data in the literature on the role of CT120 in any other cancer type. Therefore, the aim of this study was to determine the expression rate and probable function of CT120 in HNSCC.

Tumor tissues from 50 patients were analyzed by real-time quantitative RT-PCR to investigate the expression rate and by direct sequencing to differentiate the CT120A and CT120B variants. CT120 overexpression was observed in 58% of tumors compared to non-cancerous tissue samples and this up-regulation was directly associated with the upregulation of the CT120A variant and with the stage of the disease (p=0.001).

Our results indicate that the CT120 gene may function in the development of HNSCC.

DLEC1 is not silenced solely by promoter methylation in head and neck squamous cell carcinoma

Different types of genetic and epigenetic changes are associated with HNSCC. The molecular mechanisms of HNSCC carcinogenesis are still undergoing intensive investigation. The Deleted in lung and esophageal cancer 1 (DLEC1) gene is frequently silenced by methylation in various kinds of cancer. However, there is no data in the literature investigating the DLEC1 gene in the HNSCC. Tumor tissues from 97 patients were analyzed by real-time quantitative RT-PCR and DLEC1 expression levels were correlated with the methylation of the DLEC1 gene promoter. A statistically significant down-regulation was observed in tumors compared to non-cancerous tissue samples (p = 0.00). However, this down-regulation was not directly associated with hypermethylation of the promoter (p ≥ 0.05). Our results indicate that the DLEC1 gene may play an important role in the development of HNSCC. However, its down-regulation is not associated with the clinicopathological parameters and is not solely under the control of promoter methylation.

Vitamin D receptor gene haplotype is associated with late-onset Alzheimer's disease

Vitamin D(3) is a neurosteroid that mediates its effects via the vitamin D receptor (VDR). The VDR gene is located on chromosome 12q13 and consists of 9 exons. VDR contains the DNA-binding site encoded by exons 2 and 3 and the ligand-binding site encoded by exons 4 - 9. Our earlier study showed that the ApaI polymorphic site of the VDR gene is associated with late-onset Alzheimer's disease (AD). Here, we investigated the association between additional polymorphisms of the VDR gene and AD using the same samples. Two single nucleotide polymorphisms (SNPs) in intron 8 (BsmI and Tru9I polymorphisms) and one in exon 2 (FokI polymorphism) of the VDR gene were examined in up to 108 AD patients and 115 age-matched controls. Genotypes were determined with polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methods. Haplotype analysis also included the previously studied polymorphic sites that were recognized by TaqI (in exon 9) and ApaI (in intron 8) restriction enzymes. There was no significant difference between AD patients and controls when their genotypes for BsmI, Tru9I and FokI polymorphic sites were compared. However, the frequency of "TaubF" haplotype (alleles of TaqI, ApaI, Tru9I, BsmI and FokI, respectively), which was determined by analyzing 5 polymorphisms together, was significantly higher in the AD patient group, suggesting that this haplotype is a risk factor in AD. Our results point out a possible link between AD and certain VDR polymorphisms and indicate that individuals with these polymorphisms might be vulnerable to AD.

Using SELDI-TOF MS to identify serum biomarkers in NSCLC

Non-small cell lung cancer (NSCLC) is the leading cause of cancer mortality worldwide with poor differential diagnosis of the disease and with low response rates to standard chemotherapy. Individuals classified as Stage I by the present clinical-based scoring system may display survival characteristics ranging from 10 to 90 %. Identification of reliable biomarkers to detect NSCLC at early stages is therefore a subject of extensive research.

Surface-enhanced laser-desorption-ionization time-of-flight mass spectrophotometry (SELDI-TOF-MS) combines chromatographic surfaces with solid-state TOF-MS for the high throughput analysis of proteins in diverse clinical samples such as serum, urine, cerebrospinal fluids and has overcome the limitations of earlier proteomic approaches. The method has been widely used for biomarker discovery. Therefore, in this study we used the SELDI-TOF protein Chip system to achieve a stratification based on the protein expression profile and to identify differentially expressed proteins in sera from 50 patients with NSCLC and 50 healthy controls. IMAC 30-Cu protein chips were used to fractionate the proteins according to their metal binding affinity. The arrays were analyzed using the Ciphergen Protein Chip Reader PB IIa. The spectra were normalized to the total ion current of the mass to charge between 3000 — 10 000 Da. Protein peak clustering and classification analysis were performed using the Express 3.0 Biomarker Pattern Analysis Software.

Several proteins with masses ranging from 2000-20000 Da were differentially expressed between NSCLC patients and healthy controls. Among the peak clusters revealing differences we selected two specific clusters as prospective candidate biomarkers in sera of the patients. High expression of one peak and underexpression of the other with respect to the healthy control sera were evaluated in a blind test in terms of the ability to classify a separate group of patients and controls.

Relationship between two estrogen receptor-alpha gene polymorphisms and angiographic coronary artery disease

OBJECTIVE

To investigate the association of estrogen receptor-alpha PvuII and BtgI polymorphisms with angiographic presence and severity of coronary artery disease (CAD).

METHODS

Our cross-sectional study included 140 patients with >or=50% coronary stenoses (CAD group) and 47 patients with normal angiograms (CAD-free group) (total n=187, age 59.6+/- 13.2 years; 66 women). PvuII and BtgI genotype and allele distributions were determined by standard method of polymerase chain reaction and restriction fragment length polymorphism. The CAD subgroups by the number of diseased vessels were also defined. Variable associations and group differences were analyzed by independent t test, one-way ANOVA, Pearson's Chi-square, Spearman's correlation tests and logistic regression analyses.

RESULTS

While there was no association between PvuII polymorphism and angiographic CAD (p=0.384), BtgI polymorphism was more prevalent in CAD-free group (23.4% vs. 10% (CAD group), OR=2.75, 95% CI=1.150 to 6.579, p=0.019). This difference was more pronounced in women (28.6% vs. 4.4%; OR=8.6; 95% CI=1.564 to 47.303; p=0.005) compared to men (p=0.391). Logistic regression analysis confirmed BtgI polymorphism as the most important predictor for a normal coronary angiogram among parameters such as body mass index, diabetes and age (OR 8.13, 95% CI 1.257 to 52.627, p=0.028). However, no significant association between BtgI polymorphism and the number of stenotic arteries was detected.

CONCLUSION

ESR1 PvuII polymorphism is not associated with angiographically significant CAD. ESR1 BtgI polymorphism is strongly associated with the presence of normal coronary angiograms in women, which suggests protective effect. Further confirmation of these findings is required.

Factor V Leiden, Prothrombin G20210A, and Protein C Mutation Frequency in Turkish Venous Thrombosis Patients

Several inherited polymorphisms are associated with risk of venous thrombosis, including mutation at codon 506 of the factor V gene, mutation at position 20210 of the prothrombin gene, and mutations in the protein C gene. In this study, genotyping for factor V, prothrombin, and protein C mutations was performed in 50 patients and 25 control subjects by polymerase chain reaction—based analysis. The prevalence of factor V and prothrombin mutations was not significantly different from that in the general population. Nine of the patients had heterozygous protein C mutation. There was a high prevalence of the mutated protein C allele in the pulmonary emboli group (42.8%). Protein C mutation incidence was higher in the pulmonary emboli group than in the deep vein thrombosis (8.33%) and cerebral vein thrombosis (16.1%) groups. These results indicate that patients with protein C deficiency have a greater risk of thrombosis than patients with factor V or prothrombin G20210A mutation.

Preliminary study showing the relationship between platelet fibronectin, sialic acid, and ADP-induced aggregation levels in coronary heart disease

Several studies indicate that thrombosis plays an important role in the pathogenesis of coronary heart disease (CHD). Fibronectin is a multifunctional protein in plasma, other body fluids, and cell surface and plays an important role in platelet functions, including mediation of cell-cell and cell-surface interactions. Sialic acid is a regular constituent of glycoproteins and gangliozides in the outer cell membrane of mammalian cells. Therefore, the sialic acid content of platelets, which are characterized by their ability to aggregate with each other, can be important in leading to thrombus formation. In this study, platelet fibronectin, sialic acid-, and adenosine diphosphate (ADP)-induced platelet aggregation levels were determined in patients with CHD. Platelet sialic acid concentrations were determined by Warren's method. Platelet aggregation tests with ADP in platelet-rich plasma (PRP) were analyzed by use of an aggregometer. Platelet homogenate fibronectin levels were determined by ELISA. Total protein levels were determined by Lowry method. Our results indicate that, in patients with no vessel disease (patients with no obstructed vessel but suffering from chest pain, like angina pectoris) platelet fibronectin levels were significantly lower than the total of the other patients (patients with 1, 2, or 3 obstructed coronary vessels) (p<0.05). Sialic acid levels in patients with no vessel disease were significantly lower than the total of the patient group (p<0.05). There was significant (+) correlation between platelet aggregation, platelet fibronectin, platelet sialic acid, and severity of disease (p<0.05). Our preliminary findings suggest that, especially platelet fibronectin levels potentially represent a pathogenic factor for CHD.

Comparison of platelet fibronectin, ADP-induced platelet aggregation and serum total nitric oxide (NOx) levels in angiographically determined coronary artery disease

INTRODUCTION

Coronary thrombosis is an important determinant of prognosis in patients with acute coronary syndromes. Fibronectin is also found in platelets within the alpha secretory granules and secreted following platelet stimulation by a variety of agonist. Available data suggest that expression of platelet fibronectin on the cell surface may indicate a role in platelet aggregation and adhesion to fibrin thrombi and connective tissue. Clear evidence has emerged that a concerted action of nitric oxide (NO) generated by either endothelial or platelet NO synthases regulates platelet activation, causing inhibition of adhesion and aggregation. The aim of the present study was determining and correlating the serum total NO (NOx), platelet fibronectin and ADP-induced platelet aggregation levels in coronary artery disease (CAD) patient subgroups.

MATERIALS AND METHODS

A total of 43 coronary artery disease patients were included in this study. Peripheral blood samples from patients with coronary artery disease were obtained from the Department of Cardiology. Platelet aggregation tests with adenosine diphosphate (ADP) were analyzed by using aggregometer. Platelet fibronectin concentrations were determined by enzyme-linked immunosorbent assay (ELISA). Serum total nitric oxide (NOx) levels were determined by colorimetric method.

RESULTS

In patients with double-vessel disease, platelet fibronectin levels were found to be significantly higher than no-vessel disease (p<0.001), single-vessel disease (p<0.01) and triple-vessel disease (p<0.001). In addition, in patients with single-vessel disease platelet fibronectin levels significantly higher than no-vessel disease (p<0.05). We could not find any significant differences in ADP-induced platelet aggregation and serum NOx values between CAD patient subgroups. There was a positive correlation between platelet fibronectin levels and severity of disease (r=0.315, p<0.05).

Hyperhomocysteinemia in chronic renal failure patients: relation to tissue factor and platelet aggregation

BACKGROUND

A moderate increase in plasma total homocysteine (t-hcy) is considered to be an independent risk factor for cardiovascular disease (CVD) in general population. One of the mechanisms by which hyperhomocysteinemia contributes to cardiovascular risk has been explained to be the increased thrombotic potential. Elevated t-hcy levels were also reported in chronic renal failure patients because the renal function is a major determinant of serum t-hcy levels.

PATIENTS AND METHODS

We measured serum hcy and ADP-induced platelet aggregation and plasma tissue factor as a major activator of the coagulation cascade in hemodialysis (HD), peritoneal dialysis (PD) and early stage chronic renal failure (early stage CRF) patients who are not receiving dialysis and compared with those of control. In addition, we also determined serum vitamin B12 and folat levels which are the important factors regulating the metabolism of t-hcy.

RESULTS

Hcy levels in all patient groups were significantly higher (HD: 20.42 +/- 1.91 micromol/l, PD: 35.47 +/- 6.30, early stage CRF: 24.39 +/- 3.06) than the normal levels (10.74 +/- 0.74) in spite of standard multivitamin supplementation. The highest t-hcy values were found in peritoneal dialysis patients. Vitamin B12 levels in hemodialysis/peritoneal dialysis patients and folat levels in hemodialysis/early stage CRF patients were also significantly above those of control. On the other hand, the significant elevations in plasma tissue factor concentration were found in all patient groups (HD: 331.4 +/- 31.3 pg/ml, PD: 306.0 +/- 30.0, early stage CRF: 277.2 +/- 25.5 and

CONTROL

69.5 +/- 13.5). t-hcy levels were positively correlated with creatinine (r: 0.791 p < 0.002) and tissue factor levels (r: 0.526 p < 0.05) in only early stage CRF group. The association between t-hcy and tissue factor persisted after these two parameters were adjusted for creatinine (r: 0.649 p < 0.05). On the other hand the same correlations were not observed in dialysis patient groups. In spite of the high tissue factor levels, ADP-induced platelet aggregations were found to be lower in all patient groups (HD: 102.6 +/- 6.7, PD: 98.6 +/- 7.6 and Early stage CRF: 84.9 +/- 7.6) than controls (154.9 +/- 13.7).

CONCLUSION

These results suggest that hyperhomocysteinemia and increased tissue factor level are present in patients with renal failure, despite supplementation with vitamin B6 and B12 and folat. However, elevated levels of these thrombogenic factors are not linked with platelet aggregation.

Factor V Leiden mutation in cerebrovascular disease

Several studies indicate a high prevalence of factor V Leiden mutation as the most frequent coagulation defect found in patients with venous thrombosis. The relationship between this mutation and cerebrovascular disease has not been established in adults. In this investigation, we studied 29 patients with ischemic stroke and 20 with intracerebral hemorrhage, all of whom were compared with 20 controls. A region of the factor V gene containing the Leiden mutation site was amplified with polymerase chain reaction and the presence of mutation was determined with restriction enzyme digestion. We found no evidence of an association between factor V Leiden mutation and ischemic stroke or intracerebral hemorrhage. There was no evidence of association in subgroup the analysis by age, smoking status, myocardial infarction, hypertension, diabetes mellitus, or coronary disease. Factor V Leiden mutation doesn't seem to be associated with a risk of cerebrovascular disease.

Platelet function and fibrinolytic activity in patients with bronchial asthma

Platelets have the capacity to release mediators with potent inflammatory or anaphylactic properties. Platelet factor-4 (PF4) and beta-thromboglobulin (BTG) are two of these mediators. On the other hand, plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (tPA) are two important mediators of fibrinolysis. Both mediators are secreted mainly by vascular endothelium. Plasma levels of PF4, BTG, PAI-1, and tPA may show changes in chronic inflammatory diseases such as asthma. This study examined the role of thrombocytes and the function of the endothelium in asthmatic patients during an attack and during a stable phase. Eighteen patients with known allergic asthma who came to our emergency department with an asthma attack and 14 control subjects were included in the study. Blood samples were taken after starting therapy with salbutamol inhalation. Lung function tests were performed after receiving the first emergency therapy for asthma. Plasma levels of PF4, BTG, PAI-1, tPA were determined before starting steroid therapy and after receiving 1 week of steroid therapy. Plasma levels of PF4 among patients with an asthma attack were significantly higher than those of controls (150.5+/-8.92 IU/mL vs. 92.5+/-7.63 IU/mL, p<0.001). A further increase in plasma PF4 levels was detected after steroid therapy (163.5+/-9.16 IU/mL). Plasma BTG levels of patients on admission were not statistically different from those in the control group (140.4+/-6.34 IU/mL vs. 152.2+/-8.71 IU/mL). An increase was detected after therapy (171.6+/-7.27 IU/mL) and post-treatment plasma levels were statistically meaningful versus the controls. Plasma levels of tPA and PAI were statistically higher than those in controls in asthmatic patients on admission (6.01+/-2.72 vs. 5.4+/-2.3 ng/mL for tPA and 75.2+/-27.2 ng/mL vs. 32.7+/-14.3 ng/mL for PAI-1). Further increases were detected in two parameters after 1 week of therapy with steroids (tPA levels were 6.85+/-2.96 ng/mL and PAI-1 levels were 83.5+/-29.6 ng/mL). There seems to be an increased activity of platelets during an asthma attack. Elevated PAI-1 and tPA levels may also indicate the activated endothelium in asthma. Increases of plasma levels of PAI-1 and tPA after steroid therapy need further investigation because elevated PAI-1 levels enhance airway remodeling.

The relationship of TFPI, Lp(a), and oxidized LDL antibody levels in patients with coronary artery disease

OBJECTIVES

The aim of the present study was to determine and correlate tissue factor pathway inhibitor (TFPI), lipoprotein (a) (Lp(a)), oxidized low-density lipoprotein (LDL) antibody (oLAB), and thiobarbituric acid reactive substances (TBARS; as a marker of lipid peroxidation) levels in patients with coronary artery disease (CAD) and in a control group.

DESIGN AND METHODS

Peripheral blood samples from patients with coronary heart disease were provided by the Department of Cardiology. Serum oLAB, Lp(a), plasma total TFPI, and plasma-free TFPI levels were determined by ELISA. Serum TBARS levels were determined by a spectrophotometric method using thiobarbituric acid.

RESULTS

The CAD and the control group were matched for age and sex. Serum Lp(a), oLAB, and plasma total TFPI levels in patients with coronary heart disease were found to be significantly higher than in the control group (P < 0.001). But there was no difference in plasma-free TFPI levels between patients with CAD and the control group (P > 0.05). In patients with single (P < 0.05), double, and triple vessel (P < 0.01) disease, the mean serum Lp(a) levels were significantly higher than in the control group. On the other hand, in patients with single vessel disease (P < 0.05), double vessel disease (P < 0.05), and triple vessel disease (P < 0.001), plasma total TFPI levels were found to be significantly higher than in the control group. We also found a significant positive correlation (r = 0.28, P < 0.05) between serum Lp(a) and plasma total TFPI levels in CAD. In the patient group, TBARS, total cholesterol, triglyceride (TRG), and LDL cholesterol levels were found to be significantly higher than those in the control group. In addition, high-density lipoprotein (HDL) cholesterol levels were found to be significantly lower than the control group.

CONCLUSIONS

These results suggest that elevated plasma levels of total TFPI, Lp(a), and oLAB may be useful diagnostic and monitoring markers in patients with CAD.

In vivo effect of losartan on platelet aggregation in patients with hypertension

The angiotensin II receptor, losartan, has been found to inhibit platelet aggregability to some extent in in vitro experiments. There have been conflicting results about the in vivo effects of losartan. We sought to clarify the in vivo effect of losartan on platelet aggregation. Forty patients with grade I essential hypertension were treated with losartan for 3 weeks. Platelet aggregation tests with adenosine diphosphate (ADP) and ristocetin were analyzed and compared before and at the end of the study. Losartan effectively decreased systolic (SBP) and diastolic (DBP) blood pressure. Mean SBP before and after treatment was 159.6 +/- 12.8 and 149.2 +/- 17.3 mmHg, respectively. Mean DBP decreased from 93.7 +/- 8.2 to 87.7 +/- 10.3 mmHg after treatment. The results of the platelet aggregation tests with ADP and ristocetin were not significantly different when both rate and amplitude of maximal aggregation were included. Peak platelet aggregation with ADP regarding the lowest light transmission in the aggregometer was 59.8% +/- 24.3% before and 58.3% +/- 18.1% after the treatment. The same variables with ristocetin were 66.8% +/- 21.6% and 60.8% +/- 23.3%, respectively. In vivo effects of losartan on platelet aggregation with ADP and ristocetin were insignificant.

Enhanced Sensitivity to Oxidant-Induced Micronucleus Frequency in Elderly Individuals Is Not Associated with Glutathione S- Transferase M1 (GSTM1) Null Genotype in Lymphocytes

BACKGROUND

A large number of studies have demonstrated that various kinds of DNA damage accumulate during aging and that oxidative stress possibly contributes to this process. Glutathione S-transferase M1 (GSTM1) can prevent their possible effects on DNA via detoxification of reactive substances that induced oxidative stress.

OBJECTIVE

To investigate the relationship between GSTM1 polymorphism and DNA sensitivity to oxidative stress with age, we used micronucleus (MN) frequency as a marker of DNA damage in lymphocytes from young and elderly subjects.

METHODS

This study was performed in 30 young (age range 20-36 years) and 30 elderly (age range 66-87 years) healthy individuals who were chosen on the basis of their GSTM1 genotype (15 GSTM1 null and 15 GSTM1 positive for each group). Lymphocytes were cultured after Ficoll isolation and treated for 48 h with a 30-muM dose of cumene hydroperoxide (CumOOH), a dose that does not decrease cell viability.

RESULTS

There was no significant difference in the MN frequency observed in control cultures from young and elderly individuals. However, the MN frequency in CumOOH-treated cultures was significantly higher in the elderly group than the young group (p < 0.001). No association was found between the GSTM1 phenotype and CumOOH-induced MN frequency.

CONCLUSIONS

The results suggest that lymphocytes of elderly individuals are more susceptible to in vitro MN induction by CumOOH. However, this difference in susceptibility is not explained by the lack of GSTM1.

Effects of atorvastatin (10 mg) on hemostatic and inflammatory parameters in hyperlipidemic patients with angiographically proven coronary artery disease

Hyperlipidemic patients with coronary heart disease were treated with atorvastatin, and its effects on hemostatic and inflammatory parameters were assessed. After 3 months of therapy, the plasma levels of plasminogen activator inhibitor, prothrombin fragment 1+2, highly sensitive C-reactive protein, von Willebrand factor, and fibrinogen were significantly reduced; no significant reductions were observed in lipoprotein(a) and tissue plasminogen activator antigen levels.

Polymorphism analysis in the COLIA1 gene of patients with thalassemia major and intermedia

beta-Thalassemia, an inherited blood disorder, mainly affects people from the Mediterranean region. This life-threatening anemia is so severe that regular blood transfusions and iron-chelating therapy is obligatory throughout life. Commonly occurring complications, especially in adult patients, are osteopenia and osteoporosis. Osteoporotic fractures are strongly associated with bone density, which is under polygenic control. Type I collagen, which is encoded by the COLIA1 and COLIA2 genes, is the major protein in the bone. A G-->T polymorphism in the regulatory region of the COLIA1 gene at a recognition site for transcription factor Sp1 has been strongly associated with osteoporotic fractures. In this study, the G-->T polymorphism is screened in 42 beta-thalassemia major and 10 beta-thalassemia intermedia patients. 64.3% of the beta-thalassemia patients were heterozygotes for G/T (Ss) polymorphism and 35.7% were homozygous for G/G (SS), 60% of the beta-thalassemia intermedia patients were heterozygous (Ss) and 40% were homozygous (ss). The number of heterozygotes in the beta-thalassemia major group was significantly higher, compared to the control group (F = 13.615, P = 0.001). The number of heterozygotes in beta-thalassemia intermedia group was also significantly higher, compared to the control group (F = 5.158, P = 0.029). Patients who are G/T heterozygotes (Ss) at the polymorphic Sp1 site have a lower bone mineral density than G/G homozygotes (SS) (P = 0.01).

Looking for Our Ten Years Results for Coronary Heart Disease and Ischemic Stroke Group for the Standpoint of Haemostasis

To evaluate the role the coagulation and fibrinolysis abnormalities in the pathogenesis of ischemic stroke of undetermined etiology, we assayed plasma concentration of fibrinopeptide-A and thrombin-antithrombin III complex, both sensitive markers for thrombin activation and fibrin formation, and D-dimer, a marker of plasmin activity and fibrinolysis. Hemostatic markers were measured in 32 patients with acute stroke and 20 patients with chronic stroke, and compared with 21 normal subjects. Fibrinopeptid-A and thrombin-antithrombin III complex levels were not elevated significantly, whereas the D-dimer level was markedly raised in acute (p<< 0.001) and chronic (p< 0.05) phases of ischemic stroke in comparison with the control group. Prolonged elevation of D-dimer concentration suggests that hemostatic abnormalities have a primary role in the pathogenesis of ischemic stroke. The measurement of D-dimer concentration may help to better decide the indications for therapy of the patients with ischemic stroke of undetermined etiology.

Changes in the antioxidant system in epileptic children receiving antiepileptic drugs: two-year prospective studies

The aim of this study was to measure changes in the antioxidant systems of epileptic children who had been receiving either valproate or carbamazepine monotherapy for 2 years. For this purpose, levels of erythrocyte glutathione, glutathione peroxidase, superoxide dismutase, and serum lipid peroxidation in 25 healthy children and 27 children who had previously been diagnosed as having epilepsy but who had not, prior to the study, received antiepileptic drugs were tested. Of the 27 epileptic children, 14 were given valproate, and the remaining 13 were given carbamazepine; these tests were repeated in the 13th and 24th months of treatment. The results showed that, during valproate therapy, the lipid peroxidation levels of the epileptic children increased and the glutathione peroxidase levels decreased in comparison with those levels recorded in the control and pretreatment groups. In addition, the superoxide dismutase levels were found to be increased during the first year of valproate therapy when compared with those of the pretreatment group. However, during carbamazepine therapy, lipid peroxidation levels increased when compared with the control group only, not the pretreatment group. Furthermore, the results showed that during the second year of treatment, the superoxide dismutase levels of the children receiving carbamazapine monotherapy were found to be higher than those of both the control and pretreatment groups. From these results, it can be concluded that the antioxidant systems of the children who had been receiving valproate therapy during the 2 years were more significantly affected than those of the children who had been receiving carbamazepine.

Effect of acute hyperglycemia on potassium (86Rb+) permeability and plasma lipid peroxidation in subjects with normal glucose tolerance

Hyperglycemia is likely to be one of the important determinants of ion transport as it is known to induce oxidative stress and may thus enhance non-specific permeability of membranes. The aim of the present study was to evaluate the effects of an acute increase in glycemia on 86Rb+ (a marker for K+) influx and lipid peroxidation. We evaluated the 75-g oral glucose tolerance test (OGTT)-induced modification on 86Rb+ influx and plasma lipid peroxidation in 20 subjects with normal glucose tolerance (NGT). After 2-hour glucose loading, the levels of passive 86Rb+ influx and plasma lipid peroxidation were significantly increased, whereas the active influx of 86Rb+ was unchanged. The total and passive influx of 86Rb+ into erythrocytes was significantly correlated with the level of plasma lipid peroxidation. This study demonstrates that acute hyperglycemia induces an increase in the passive influx of 86Rb+ in subjects with NGT, suggesting that acute hyperglycemia may produce an oxidative stress in plasma. These changes may be among the earliest changes occurring in response to hyperglycemia.

Inhibition of platelet function by GSTM1-null human peripheral lymphocytes exposed to benzo(a)pyrene-induced challenge

Recent epidemiological studies proposed that the glutathione S-transferase (GST) M1-null genotype may contribute to diseases associated with oxidative stress. The genetic polymorphism exhibited by the GSTM1 may be an important factor in risk toward oxidant chemicals. In this study, we investigated the effect of GSTM1-null genotype in lymphocyte and oxidative stress-dependent inhibition of platelet aggregation. To determine whether GSTM1 deficiency is a genetic determinant of cell toxicity toward oxidant chemicals, lymphocytes were incubated in vitro with low levels of benzo(a)pyrene (BaP), cumene hydroperoxide (CumOOH), or trans-stilbene oxide that do not decrease cell viability, and were assessed for oxidative damage and for the lymphocyte-dependent inhibition of platelet response. Malondialdehyde and carbonyl levels, and the oxidation of cisparinaric acid, were used as biomarkers of oxidative stress in lymphocytes. Following stimulation by BaP or CumOOH, when peroxidation-dependent changes in these parameters were compared between the GSTM1-null genotype and the positive genotype, no significant differences were found between the two genotypes. On the other hand, preincubation of the lymphocytes with BaP or CumOOH attenuated their inhibitory action on ADP-induced platelet aggregation. However, our results indicate that lymphocytes of individuals with the GSTM1-null genotype have greater inhibitory activity on platelet function after exposure to BaP, but not CumOOH, although they are not more susceptible to in vitro oxidative stress.

Factor VII levels in patients undergoing coronary angiography: factor VII and coronary artery disease

BACKGROUND

Factor VII (F VII) has been widely investigated as a risk factor for coronary atherosclerosis, however there is still debate about its role in the progression of coronary artery disease (CAD). In this study F VII levels were measured in patients with angiographically proven CAD and its relation with disease severity, coronary events and with other risk factors of coronary atherosclerosis were examined.

METHODS

Consecutive patients referred to coronary angiography were divided in three groups: 1. CAD group--those with a significant lesion in one or more coronary arteries (n = 155), 2. High-risk group--patients with normal coronary arteries and with two or more risk factors (n = 54), 3. Controls--patients with normal coronary arteries and with no or one risk factor (n = 90). CAD group was also studied according to the number of vessels involved and to the history of coronary events.

RESULTS

Mean F VII levels were not different between the three groups of patients. In CAD group, F VII increased parallel to the number of vessels involved (one vessel disease: 85 +/- 20%, two vessel disease: 92 +/- 23%, three vessel disease: 105 +/- 23%). Patients with a history of coronary events had significantly higher F VII levels than those without such a history (96 +/- 25% versus 89 +/- 22% respectively, P = 0.02). However, logistic regression analysis revealed no significant relation between F VII and either the presence of CAD or coronary events.

CONCLUSIONS

F VII levels increase in patients with previous coronary events, but it is not an independent risk factor for the progression or for the severity of CAD.

Effect of acute hyperglycemia on potassium (86Rb+) permeability and plasma lipid peroxidation in subjects with normal glucose tolerance

Hyperglycemia is likely to be one of the important determinants of ion transport as it is known to induce oxidative stress and may thus enhance non-specific permeability of membranes. The aim of the present study was to evaluate the effects of an acute increase in glycemia on 86Rb+ (a marker for K+) influx and lipid peroxidation. We evaluated the 75-g oral glucose tolerance test (OGTT)-induced modification on 86Rb+ influx and plasma lipid peroxidation in 20 subjects with normal glucose tolerance (NGT). After 2-hour glucose loading, the levels of passive 86Rb+ influx and plasma lipid peroxidation were significantly increased, whereas the active influx of 86Rb+ was unchanged. The total and passive influx of 86Rb+ into erythrocytes was significantly correlated with the level of plasma lipid peroxidation. This study demonstrates that acute hyperglycemia induces an increase in the passive influx of 86Rb+ in subjects with NGT, suggesting that acute hyperglycemia may produce an oxidative stress in plasma. These changes may be among the earliest changes occurring in response to hyperglycemia.

The influence of GSTM1 null genotype on susceptibility to in vitro oxidative stress

From epidemiological studies, there is some evidence that genetic variation at the glutathione S-transferase (GST) loci GSTM1 influences individual susceptibility to disease associated with oxidative stress. The aim of this study was to elucidate the role of the GSTM1 genotype in protection against oxidant chemicals by comparing the sensitivity, genotoxicity and cytotoxicity of lymphocytes to benzo(a)pyrene (BaP)- and cumene hydroperoxide (CumOOH)-induced in vitro oxidative challenge. Malondialdehyde and protein carbonyl levels, and oxidation of 2',7'-dichlorofluorescin diacetate were used as biomarkers of oxidative stress in lymphocytes. Following supplementation with BaP or CumOOH, time-dependent increases were observed in the production of all the markers after incubation for 12-48 h. However, we could not find any differences between GSTM1 null and positive genotypes. Furthermore, dose or time response experiments indicated that GSTM1-deficient cells were not more sensitive than control cells to BaP-or CumOOH-induced cell killing and micronucleus formation, although they were hypersensitive to BaP-inhibited cellular growth. The results suggest that lymphocytes from individuals with the GSTM1 null genotype are not abnormally susceptible to in vitro induced oxidant challenge, when exposed to CumOOH.