Effects of type 2 diabetes mellitus on plasma fatty acid composition and cholesterol content of erythrocyte and leukocyte membranes.

Insulin resistance is a major factor in the pathogenesis of type 2 diabetes mellitus (T2DM) and is related to the fatty acid profile of the plasma membranes. The purpose of the present study was to investigate fatty acid composition and cholesterol content of cell membranes in patients with type 2 diabetes and, thus, to evaluate the possible factors leading to the alteration of plasma membrane fluidity. The study was performed in 20 healthy control subjects and 32 patients with type 2 diabetes. The fatty acid profiles and cholesterol content of the erythrocyte (RBC) and leukocyte (WBC) membranes were determined by a gas chromatographic method. When one considers the membrane constituents increasing fluidity and the ones decreasing it, the diabetics had a membrane composition decreasing fluidity compared to controls. On the other hand, when compared to control subjects, type 2 diabetic patients showed a significantly higher proportion of C16:0 components in erythrocyte and leukocyte membranes and plasma samples (25.4+/-3.1% vs. 31.1+/-4%; 23.3+/-2.4% vs. 29.3+/-5.2%; 27.6+/-3.9% vs. 34.5+/-5.7%; p<0.005, p<0.01 and p<0.005, respectively). Our results suggest that the ratio of saturated:unsaturated fatty acids changes in plasma and cell membranes of patients with type 2 diabetes. This situation may cause, at least in part, RBC-WBC function abnormalities and insulin resistance because of inconvenient membrane fluidity.

Serum lipoprotein(a) level and its clinical significance in patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a classic autoimmune disease characterised by the production of autoreactive T cells and autoantibodies that may affect every organ system. It has long been established that there is a close association between cholesterol- rich lipoproteins (such as low-density lipoprotein-cholesterol) and cardiovascular disease in patients with SLE. In this study, we evaluated total cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, VLD-cholesterol, apolipoprotein A-1, apolipoprotein B, and cholesterol-rich serum lipoprotein(a) [Lp(a)], which is accepted to be an independent risk factor for cardiovascular disease and for atherosclerosis, in 24 patients (mean age +/- SD 31.4 +/- 9.7 years, range 16-47, 22 F) with active SLE. Twenty-six healthy age- and sex-matched (mean age +/- SD 29.7 +/- 11.3 years, range 18-49 years, 22 F) subjects were included as a control group. In patients with SLE Lp(a) levels, total cholesterol, triglycerides and VLDL-cholesterol were found to be higher and HDL-cholesterol, apolipoprotein A-1 to be lower than those of controls. In conclusion, because serum Lp(a) levels are significantly higher (P<0.01) in patients with SLE, these patients have a risk of developing cardiovascular disease and atherosclerosis. Patients with SLE should be followed up with this in mind.

Serum paraoxonase levels in pancreatic cancer.

BACKGROUND/AIMS: Serum paraoxonase (PON) is a calcium-dependent esterase that is known to contribute to the antioxidant protection conferred by high-density lipoprotein (HDL) on low-density lipoprotein (LDL) oxidation. Serum PON activity was shown to be reduced in patients with diseases such as myocardial infarction, diabetes mellitus, etc in comparison to healthy subjects. However, the relation of serum PON levels to cancer is still not known. So, we intended to measure serum PON, HDL, LDL and very low-density lipoprotein (VLDL) levels and to investigate the relation of serum PON to plasma lipoproteins in the patients with pancreatic cancer. METHODOLOGY: We measured serum PON, HDL, LDL, and VLDL levels in 20 patients with pancreatic cancer and in 20 age-and gender-matched healthy controls. We investigated the relationship between PON and HDL, PON and LDL, and PON and VLDL. RESULTS: Serum HDL levels were lower in the patients than in controls (40.21 +/- 13.82 mg/dL, and 47.30 +/- 6.65 mg/dL, respectively) (p<0.05). Serum LDL and VLDL levels measured in the patient group were not significantly different from those of the control group. Serum PON levels were lower in the patients than in controls (61.57 +/- 22.44 U/L, and 87.50 +/- 23.39 U/L, respectively) (p<0.005). There was a positive correlation between serum PON and HDL levels (r: 0.69, p<0.05). CONCLUSIONS: We concluded that the patients with pancreatic cancer had low PON and HDL levels compared to healthy controls. The importance of PON as a predictive risk factor for cancer should be assessed in future studies.

Serum paraoxonase levels in gastric cancer.

BACKGROUND/AIMS: Serum paraoxonase (PON) is a calcium-dependent esterase that is known to contribute to the antioxidant protection conferred by high-density lipoprotein (HDL) on low-density lipoprotein (LDL) oxidation. Serum PON activity was shown to be reduced in patients with diseases such as myocardial infarction, diabetes mellitus, etc in comparison to healthy subjects. However, the relation of serum PON levels to cancer is still not known. So, we intended to measure serum PON, HDL, LDL and very low-density lipoprotein (VLDL) levels and to investigate the relation of serum PON to plasma lipoproteins in the patients with gastric cancer. METHODOLOGY: We measured serum PON, HDL, LDL and VLDL levels in 20 patients with gastric cancer and in 20 age-and gender-matched healthy controls. We investigated the relationship between PON and HDL, PON and LDL, and PON and VLDL. RESULTS: Serum HDL levels were lower in the patients than in controls (33.10 +/- 7.75 mg/dL, and 47.30 +/- 6.65 mg/dL, respectively) (p<0.0001). Serum VLDL levels were lower in the patients than in controls (21.65 +/- 6.92 mg/dL, and 33.10 +/- 6.09 mg/dL, respectively) (p<0.0001). Serum LDL levels measured in the patients were not significantly different from those of the controls. Serum PON levels were lower in the patients than in controls (67.10 +/- 17.92 U/L, and 87.50 +/- 23.39 U/L, respectively) and there was a positive correlation between serum PON and HDL levels (r: 0.52, p<0.05). CONCLUSIONS: We concluded that the patients with gastric cancer had low serum PON, HDL, and VLDL levels compared to healthy controls. The importance of PON as a predictive risk factor for cancer should be assessed in future studies.

Endurance training attenuates the oxidative stress due to acute exhaustive exercise in rat liver.

The aim of this study was to investigate whether an 8-week treadmill training attenuates exercise-induced oxidative stress in rat liver. Male rats were divided into untrained and trained groups. Endurance training consisted of treadmill running at a speed of 2.1 km/h, 1.5 h/day, 5 days a week for 8 weeks. To see the effects of endurance training on acute exhaustive exercise induced oxidative stress, untrained and trained rats were further devided into two groups: animals killed at rest and those killed after acute exhaustive exercise, in which the rats run at 2.1 km/h (10% uphill) until exhaustion. Acute exhaustive exercise increased malondialdehyde level in untrained but not in trained rats. It decreased the activity of glutathione peroxidase and total (enzymatic plus non-enzymatic) superoxide scavenger activity in untrained rats and catalase activity in trained rats. However, it did not affect glutathione S-transferase, glutathione reductase, superoxide dismutase and non-enzymatic superoxide radical scavenger activities in both trained and untrained rats. On the other hand, endurance training decreased glutathione peroxidase and glutathione S-transferase activities. The results suggested that endurance training attenuated exercise-induced oxidative stress in liver, probably by preventing the decreases in glutathione peroxidase and total superoxide scavenger activities during exercise.

Nitric oxide concentrations in saliva and dental plaque in relation to caries experience and oral hygiene.

The aim of the study was to determine the correlation of the antibacterial substance nitric oxide (NO) with dental caries in vivo. Salivary and dental plaque NO concentrations were analyzed by the Griess method in 11 subjects with high DMFT index and simplified oral hygiene index (OHI-S), 11 with low DMFT and OHI-S. Subjects with high DMFT and OHI-S had significantly higher NO concentrations in saliva (71.5 microM) and plaque (83.5 microM) than those with low DMFT and OHI-S (33.2 and 61.1 microM in saliva and plaque, respectively). Plaque NO concentrations were significantly higher than in saliva in both groups. NO production might be a host defense mechanism when dental caries increases or oral hygiene deteriorates.

Investigation of expression of HOX 2C and HOX 4B homeobox genes in human colorectal cancer by using an RT-PCR method.

Investigation of expression of both HOX 2C and HOX 4B homeobox genes in the same patient with colorectal cancer was proposed by using an RT-PCR method. In order to conduct this investigation, PCR products of 445 bp of HOX 2C and 301 bp of HOX 4B were amplified in both tumor and normal samples of ten patients. Expressions of HOX 2C gene were observed in both tumor and normal samples of four patients and in only a tumor sample of one patient, while the expression was not observed in both tumor and normal samples of five patients. Expressions of HOX 4B gene were not observed in both tumor and normal samples of ten patients. In the present study, it was found that individuality seems to be important. The results of these two genes, observed in patients with colorectal cancer, should be taken into consideration for further researches.

Prevalence of hepatitis C virus and hepatitis G virus in patients with non-Hodgkin's lymphoma.

Hepatitis C virus (HCV) and hepatitis G virus (HGV) belong to the same family of flaviviridea. A causative role of HCV infection in the pathogenesis of non-Hodgkin's lymphoma (NHL) has been discussed widely. Little is known about the possible association between NHL and HGV discovered recently. In this study, anti-HCV and HGV-RNA prevalence were investigated in a group of 70 patients with NHL. The results were compared to a control group of 70 age- and sex-matched healthy subjects. One patient in each group (1.4%) was found to be anti-HCV-positive; the difference was not statistically significant (P > 0.05). Five subjects in the patient group (7.1%) were positive for HGV-RNA, while a single subject was positive in the control group (1.4%); the difference was not statistically significant (P > 0.05). Odds ratios for anti-HCV and HGV-RNA were 1 and 5.30, respectively. Our findings suggest that neither HCV nor HGV are causative or contributing factors in the aetiopathogenesis of NHL.

Increased lipoprotein (a) and its relationships with other parameters of lipoprotein metabolism in chronic renal failure treated by hemodialysis.

BACKGROUND: Studies have shown that patients with chronic renal failure have a high frequency of cardiovascular atheromatous disease. METHODS: We examined serum lipoprotein (a) [Lp(a)], very-low density lipoprotein cholesterol (VLDL-C), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C), apolipoprotein A1 (apo A1) and B (apo B), triglyceride (TG) and total cholesterol (TC) levels as possible risk factors for atherosclerosis in 45 patients with chronic renal failure (CRF) treated by hemodialysis (HD) and in 15 CRF patients who were not on HD. A control group of 20 healthy subjects was also studied. RESULTS: The proportion of smokers and body mass indexes were similar between the groups. In both patient groups, higher TG, TC and Lp(a) and lower apo A1 and HDL-C levels in serum were found than in those of controls. Serum apo B and LDL-C were similar in the patients treated by HD and the controls. Serum VLDL-C and LDL-C were similar in the CRF patients who were not on HD and the controls. The highest ratios of apo B/apo A1 and LDL-C/HDL-C were found in HD patients. The highest ratio of TC/HDL-C was found in the other patient group. We found significant correlations between Lp(a) and other parameters of lipoprotein metabolism in CRF patients, both those who were and those who were not on HD. CONCLUSIONS: Our results indicate that CRF patients who both were and were not on HD show atherogenic changes in the lipoprotein pattern, and that the increase in Lp(a) during the CRF phase is basically related to the loss of renal function and may also depend on the resultant alterations which are produced in other lipoprotein variables.