The effect of low-carbohydrates calorie-restricted diet on visceral adipose tissue and metabolic status in psoriasis patients receiving TNF-alpha inhibitors: results of an open label controlled, prospective, clinical study.

OBJECTIVE: TNF alpha inhibitors are usually associated with anthropometric changes over the time, however whether and how the visceral adipose tissue (VAT) is involved in this phenomenon, still remains unclear. Aim of the study is to evaluate if the increases in trunk fat percentage (TF%) and VAT are directly involved in anthropometric changes occurring during treatment, and whether and how a calorie restricted diet could prevent these changes. MATERIAL AND METHODS: Twenty patients receiving TNF-alpha inhibitors for psoriasis was evaluated at baseline (T0) and after 24 weeks of therapy (T24), and then compared with 25 patients receiving a combined treatment based on TNF alpha inhibitors and low-carbohydrates calorie-restricted diet. RESULTS: TNF-alpha inhibitors do not influence the VAT expression. The combined treatment is associated with a significant decrease in body weight (kg) (p < .0001), BMI (p = .0001), WC (cm) (p < .0001), TF% (p < .0001), VAT (p < .0001), serum levels of triglycerides (mg/dL) (p = .0018) and total cholesterol (mg/dL) (p = .0005). CONCLUSIONS: The administration of TNF-alpha inhibitors can induce anthropometric changes after 24 weeks, but it does not cause an increase in VAT. The association between low-carbohydrates calorie-restricted diet and anti-TNF-alpha therapy seems to be able to improve the anthropometric profile of psoriasis patients.

Reduced Na(+)-K(+)-ATPase activity and plasma lysophosphatidylcholine concentrations in diabetic patients.

A fraction from normal human plasma inhibiting Na(+)-K(+)-ATPase has been recently identified as lysophosphatidylcholine (LPC). The aim of this study was to investigate the existence of a relationship between the activity of the cellular membrane Na(+)-K(+)-ATPase and plasma LPC in human diabetes. We studied 10 patients with insulin-dependent-diabetes mellitus (IDDM), 14 patients with non-insulin-dependent diabetes mellitus (NIDDM), and 10 sex- and age-matched control subjects. Plasma LPC concentrations were increased in both IDDM and NIDDM patients compared with control subjects. Na(+)-K(+)-ATPase activity was reduced in both groups of patients in erythrocyte and platelet membranes. There was a significant correlation between the concentrations of plasma LPC and Na(+)-K(+)-ATPase activity in both erythrocyte and platelet membranes (P < 0.01). To investigate the effect of LPC on the enzyme, Na(+)-K(+)-ATPase activity was determined in erythrocyte membranes obtained from six healthy subjects after in vitro incubation with increasing concentrations of LPC (1-10 microM). Enzymatic activity was significantly reduced by in vitro LPC at a concentration of 2.5 microM, with a further decrease at 5 microM. These data suggest that the decrease in Na(+)-K(+)-ATPase activity in diabetes might be due to increased LPC concentrations.

Increased susceptibility to lipid oxidation of low-density lipoproteins and erythrocyte membranes from diabetic patients.

The aim of the present study was to determine if low-density lipoproteins (LDLs) and red blood cell (RBC) membranes from diabetic patients present an increased susceptibility to lipoperoxidation, which might be related to the increased incidence of atherosclerosis in diabetes. LDLs and RBC membranes were isolated from 11 insulin-dependent (IDDM) and 18 non-insulin-dependent diabetic (NIDDM) patients and exposed to a peroxidative stress by incubation with phenylhydrazine. The susceptibility to peroxidation was determined by measuring the production of thiobarbituric acid-reactive substances (TBARS) after the incubation. The following parameters were also evaluated: plasma glucose, triglycerides (TG), phospholipids (PL), total and high-density lipoprotein (HDL) cholesterol, apolipoprotein (apo) A-I, apo B, hemoglobin A1c (HbA1c), LDL PL and cholesterol, LDL fatty acid composition, and RBC membrane PL and cholesterol. Although they were apparently normolipidemic, diabetic patients showed an increased susceptibility to peroxidation in LDLs and erythrocyte membranes as compared with control subjects. The amount of arachidonic acid in LDLs and the PL concentration of RBC membranes from diabetic patients were significantly higher than in normal subjects. The increased lipoperoxidability of both RBC membranes and LDLs might play a central role in the pathogenesis of the vascular complications of diabetes mellitus.

Modified fluidity and lipid composition in lipoproteins and platelet membranes from diabetic patients.

The interaction between lipoproteins and the platelet membrane has been proved to cause a modification in cellular functions. We studied 12 men with insulin-dependent diabetes mellitus (IDDM), 14 men with noninsulin-dependent diabetes mellitus (NIDDM), and 26 age-matched healthy men on the same diet. We determined fluidity by measuring the fluorescence polarization (P) of the probe 1,6-diphenyl-1,3,5-hexatriene (DPH) both in platelet membranes and in lipoproteins isolated by ultracentrifugation in NaBr density gradient. The lipid composition of lipoproteins and of platelet membranes was determined by enzymatic methods. The fluidity of platelet membranes was significantly increased both in patients affected by NIDDM and in subjects with IDDM compared with normal subjects. Low-density lipoproteins (LDL) showed an increased fluidity only in NIDDM patients. A percent increase in the triglyceride content was observed in all lipoprotein fractions in diabetic subjects. Increased phospholipid content was found in the platelet membranes from IDDM and NIDDM patients. The change in LDL fluidity observed in NIDDM patients might determine altered interactions between the lipoprotein and cellular receptors. The role of lipoproteins in the modulation of the platelet membrane properties in diabetes mellitus deserves further studies.

Effect of aluminium ions on liposomal membranes as detected by Laurdan fluorescence.

We report here an investigation of the influence of aluminium on iron-induced peroxidation in brain model membranes. Laurdan fluorescence emission spectra and generalised polarisation measurements have been used to investigate how ferrous and aluminium ions can affect the phase components of phospholipid membranes. An increase in the generalised polarisation of oxidised liposomes with respect to controls has been observed, which reveals the presence of a less polar environment surrounding the probe that changes the properties of the bilayer. Aluminium has been shown to facilitate iron-mediated oxidation as detected from emission fluorescence spectra. However, no quantitative influence has been calculated relative to general polarisation and derived phase state determinations. The structural influence of aluminium on membranes may therefore be less significantly marked than initially expected.

Lipoprotein peroxidation in adult psoriatic patients.

Psoriasis, a chronic inflammatory skin disease characterized by an aberration of lipid metabolism, has been associated with an increased risk for atherosclerosis. Since oxidatively modified lipoproteins are involved in the pathogenesis of atherosclerosis, we investigated the lipid composition and in vitro induced peroxidation of very low density lipoproteins (VLDL) and low density lipoproteins (LDL) from psoriatic patients. 11 male adult psoriatics and 16 male age-matched healthy subjects were studied. Lipid peroxidation of VLDL and LDL was performed by incubation with CuSO4 for 24 h at 37 degrees C. The compositional analysis showed a significant increase in triglycerides and phospholipids, both in VLDL (p < 0.05) and in LDL (p < 0.001) from psoriatic patients, compared with controls. Moreover a significant increase in total cholesterol (TC) (p < 0.01) and apoprotein (P) (p < 0.05) was found in LDL from psoriatics. The levels of thiobarbituric acid reactive substances (TBARS), as a measurement of lipid peroxidation, were significantly higher in Ox-VLDL and in Ox-LDL from psoriatics (p < 0.01) than the corresponding values in controls. Moreover, basal values of TBARS were significantly higher in VLDL and LDL from psoriatic patients than those from controls. In conclusion, the lipoprotein compositional changes associated with the modifications of TBARS before and after Cu2+ treatment of lipoproteins may suggest an increased risk for atherosclerosis in adult psoriatic patients.

[Thyroid gland surgery--a contribution to the discussion on its surgical technique]. / Chirurgie stítné zlázy--príspevek k diskusi o technice operování.

The authors present their thyroid gland operation results from the point of view of the current discussion on various techniques of the thyroid surgical procedures.

Physico-chemical properties of copper-oxidized high density lipoprotein: a fluorescence study.

The modifications of the physico-chemical properties of the high density lipoprotein (HDL) before and after in vitro induced oxidation by copper ions have been studied using the fluorescence polarization (Pf) of the phosphatidylcholine derivative of 1,6-diphenyl-1,3,5-hexatriene (DPH-PC) and of the cationic derivative (TMA-DPH). We have observed that HDL oxidation is associated with a decrease of the molecular order at the lipoprotein surface as demonstrated by the increase in Pf with respect to untreated HDL. Moreover in oxidized HDL the polarity-sensitive probe laurdan has shown a decrease of the polarity in its microenvironment. It has been suggested that a decrease in HDL fluidity would inhibit cholesterol reverse transport from peripheral tissues in form of HDL core cholesteryl esters. Peroxidation of HDL, if occurring in vivo, could contribute to the progress of atherogenesis by decreasing cholesterol efflux from peripheral tissues.

Modifications of functional and physico-chemical properties of rat ileal plasma membranes.

A membrane fraction enriched with plasma membranes was isolated from rat ileal brush-border cells before and after five-day starvation of the animals. Cholesterol/phospholipid ratio of the standard cell membranes decreased highly significantly (0.42 to 0.18), as did the microviscosity of the membranes determined by polarization of fluorescence (0.187 to 0.142). Concomitantly, the specific activity of Na,K-ATPase in the basolateral membranes significantly increased (59 to 83 mumol ATP hydrolyzed per mg protein per min).

Lower susceptibility of low density lipoprotein to in vitro oxidation in diabetic patients.

The susceptibility to peroxidative stress of low density lipoprotein (LDL), induced by incubation with CuSO4, has been studied in eleven diabetic patients and eleven control subjects. Our results suggest that oxidized LDL (OX-LDL) of diabetic patients have a significant higher reactivity to 2,4,6-trinitrobenzene sulfonic acid (TNBS) than controls, that indicates a lower susceptibility of LDL to oxidative stress. Furthermore using the fluorescence polarization (Pf) of 1,6-diphenyl-1,3,5-hexatriene (DPH) and its phosphatidylcholine derivative (DPH-PC) we have shown that peroxidation induces a decrease of fluidity in OX-LDL of controls and diabetic patients, both at the lipoprotein surface, where is localized DPH-PC and at the interface between lipoprotein surface and core which is probed by DPH.

Physico-chemical properties of copper-oxidized very low density lipoproteins.

The aim of our study was to investigate the effect of Cu2+ catalyzed oxidation on VLDL physico-chemical properties and secondary structure of apo B-100. Incubation of very low density lipoproteins with copper ions resulted in a decrease in tryptophan and lysine residues parallel to lipid peroxidation products, conjugated dienes and TBARS. Fluorescence polarization showed an increase in the molecular order at the lipoprotein surface of VLDL, as demonstrated by the increase in Pf values of DPH. The secondary structure of apo B-100 was investigated by infrared spectroscopy. Increased order and structural changes, as observed after oxidative stress on VLDL, could be of relevance in the abnormal interactions between lipoproteins and cell membranes.

Effect of desialylation on low density lipoproteins: comparative study before and after oxidative stress.

Aim of our study was to investigate the effect of the desialylation induced by neuraminidase treatment on low density lipoprotein susceptibility to peroxidative stress induced by incubation with copper ions. Our results show that peroxidative stress induces the formation of aggregates that was not observed in desialylated low density lipoproteins. An increase in thiobarbituric reactive substances and a decrease in polyunsaturated fatty acids content have been shown in oxidized LDL. These modifications were less pronounced in oxidized low density lipoproteins previously treated by neuraminidase. The present data suggest a lower susceptibility to peroxidative stress in previously desialylated low density lipoproteins.

Abnormalities of plasma lipoprotein composition and fluidity in psoriasis.

We have studied the lipoprotein chemical composition and fluidity, using the fluorescence polarization of the probe 1,6-diphenyl-1,3,5-hexatriene (DPH) in two age- and sex-matched groups of subjects (14 healthy normolipidemic children and 15 psoriatic children). The compositional study has shown a significant increase of the percentage content in triacylglycerol and a significant decrease of the apo-protein content in all lipoprotein fractions of psoriatic children compared to the controls. A significant increase of the percentage content in total cholesterol and of the cholesterol/protein ratio has also been observed in low-density lipoproteins (LDL) and in high-density lipoproteins (HDL) of psoriatic children. The compositional changes were associated with alterations of fluidity in LDL and HDL of psoriatic patients. The modifications of lipoprotein composition and fluidity observed in psoriatic patients could be of physiopathological and clinical relevance in relation to the pathogenesis of the disease.

[Prevalence of Giardia lamblia, its detection in water and its relationship with environmental factors in Gualeguaychú, Argentina]. / Prevalencia de Giardia lamblia, su detección en aguas y su relación con factores ambientales en Gualeguaychú. Argentina.

The increasing environmental contamination affects the water quality, and is going to raise the waterborne intestinal infections such as giardiosis. This study determined the prevalence of G.lamblia infection in 1201 persons of Gualeguaychú, Argentina. It was observed the relationship between giardiosis and the detection of G.lamblia in the recreational and drinking water and with homes environmental factors. General rate of infection was 19.7%. The group 2-11 years old was the highest (28.0%). No cysts of G.lamblia were found in drinking water, but recreational water was contaminated. Higher rate of infected persons lived in suburban dwellings with dirt floor, latrine, ground-water and close contact with dogs. It is concluded that to drink water is no risk-infection at present, but it will be if this community continues discharging excretsa into the river because this is the source of water for the habitants.

Study of fluidity of low density lipoproteins from liver cirrhotic patients.

BACKGROUND AND AIM: Liver disease is accompanied by major quantitative and qualitative modifications in plasma lipoprotein metabolism. Alterations in plasma lipoprotein composition and a lower susceptibility to in vitro peroxidation of low density lipoprotein (LDL) and erythrocyte membranes have been observed in liver cirrhosis. The main objective of the present work was to investigate LDL chemical composition and fluidity in liver cirrhosis using the fluorescence polarization (Pf) of the 1,6-diphenyl-1,3,5-hexatriene (DPH) probe. METHODS AND RESULTS: The chemical composition of LDL was studied in 12 cirrhotic patients and 22 controls by conventional methods and its fatty acid composition by gas chromatography. LDL fluidity was determined by measuring the DPH Pf values. A decrease in molecular order was demonstrated by the significant (p < 0.05) decrease in Pf values in the cirrhotics. Modifications in LDL fluidity are correlated with its composition. A significant increase in triglyceride content (p < 0.05), and significant increases in triglyceride/protein and triglyceride/phospholipid ratios were observed in the cirrhotics. CONCLUSIONS: Our results demonstrate that the higher LDL fluidity of cirrhotic patients may be due to an increased triglyceride content.

Susceptibility to in vitro lipid peroxidation of low density lipoproteins and erythrocyte membranes from liver cirrhotic patients.

The aim of the present study was to investigate the susceptibility of low density lipoprotein (LDL) and red blood cell membranes (RCM) from liver cirrhotic patients and control subjects, to the peroxidative stress, induced in vitro by phenylhydrazine. The susceptibility to peroxidation was determined by measuring the formation of the thiobarbituric acid reactive substances (TBARS) after incubation with phenylhydrazine. Moreover the levels of cholesterol (C) and phospholipid (PL) were evaluated in plasma and isolated LDL and RCM. A significant decrease in plasma C, LDL-C and RCM-C content (p < 0.001, p < 0.01 and p < 0.05 respectively) and RCM-PL content (p < 0.01) were found in cirrhotic patients compared to controls. The lower susceptibility to in vitro peroxidation was shown by the TBARS levels significantly lower in LDL and RCM from cirrhotic patients with respect to controls (p < 0.0001 for both of them). Moreover significant positive correlations were found between TBARS-LDL and LDL-C or LDL-PL (r = +0.72, p < 0.0001; r = +0.58, p < 0.001) and between TBARS-RCM and RCM-C (r = +0.35, p < 0.05) or RCM-PL (r = 0.37, p < 0.05) from combined patients and controls. Our data seem to ascribe the lower in vitro peroxidability to the lower levels of plasma lipids.