Nickel sulphate and epoxy resin: differences in iron status and glutathione redox ratio at the time of patch testing

The reactive patch test reaction is a useful model to characterize oxidative stress in acute allergic contact dermatitis. This model was used to study oxidative stress in the skin of individuals allergic to nickel and epoxy resin. The study included six and five patients, respectively, whose skin was simultaneously biopsied from a positive patch test site and from an apparently healthy area. The biopsies were homogenized and used for determination of iron content, unbound iron binding capacity, diene conjugate levels, and glutathione redox ratio. A positive test reaction to 5% nickel sulphate was accompanied by 2.5-fold increase in iron level as compared to apparently healthy skin (P<0.1). The percentage saturation of iron-binding capacity and the glutathione redox ratio were significantly increased (P<0.01 and P<0.05, respectively). Reactive patch test responses to 1% epoxy resin were not accompanied by clear alterations in iron status or glutathione redox ratio. Our investigation showed that apart from oxidative burst caused by accumulation of inflammatory cells, hapten properties might also influence the oxidative stress status of the skin. The high incidence of nickel allergy may be attributed, at least in part, to the influence of nickel ions on the glutathione redox ratio and iron status of the skin.     

Beneficial effects of water-based exercise in patients with chronic kidney disease

The possible beneficial effect of regular aquatic exercise on cardiorespiratory, renal lipid parameters and oxidative stress status was studied in patients with mild to moderate renal failure. The exercise group did low-intensity aerobic exercise in the pool during a period of 12 weeks, twice a week, with sessions lasting for 30 min. Matched control participants remained sedentary. The results showed that in the exercise group all cardiorespiratory functional parameters improved and resting blood pressure lowered significantly. Proteinuria and cystatin-C were diminished significantly and glomerular filtration rate was enhanced. To evaluate the changes in oxidative stress status in the serum, products of lipid peroxidation (LPO) and serum glutathione values were measured. LPO was reduced significantly and reduced glutathione levels showed significant improvement after the exercise-conditioning programme. In the control group the data either remained the same or worsened in the same period of time. In conclusion, regular water-based exercise has beneficial effects on the cardiorespiratory, renal functional parameters and oxidative stress status in patients with moderate renal failure, and can be used in the complex rehabilitation of chronic renal failure patients, together with blood pressure control, dietary consultation, encouragement and education to prevent physical worsening and to postpone cardiovascular and renal atherosclerotic complications.     

Endothelial function, CRP and oxidative stress in chronic kidney disease

BACKGROUND: Chronic kidney disease (CKD) is associated with increased morbidity and mortality in cardiovascular disease (CVD). Apart from traditional risk factors, chronic inflammation, oxidative stress, malnutrition and endothelial dysfunction are important in CVD development in renal patients. Our aim was to investigate the relationship between high sensitivity C-reactive protein (CRP), endothelium dependent vasodilation (EDV) and oxidative stress markers in patients with CKD K/DOQI stage 3-5. METHODS: Measurements of CRP, conjugated dienes (CD), lipid hydroperoxide (LOOH), oxidized low density lipoprotein,glutathione and albumin were performed in 44 consecutive patients with CKD stage 3-5. EDV was measured by methacholine infusion in the brachial artery and venous occlusion plethysmography. RESULTS: Patients with high CRP had significantly lower glomerular filtration rates and albumin, but increased LOOH and CD. In multiple regression analysis, only LOOH and CD remained significant. Patients with poor EDV had increased urea and lower glutathione (GSH). In multiple regression analysis, GSH and urea were independently related to EDV. No correlation was found between CRP and endothelial function. CONCLUSION: CRP was related to lipid peroxidation, while endothelial function was related to intracellular oxidative stress in patients with CKD. CRP and EDV were unrelated to each other. Therefore, CRP and endothelial function could provide complementary prognostic information regarding future cardiovascular disorders in renal patients.     

Use of nonbreakpoint DNA probes to detect the t(X;18) in interphase cells from synovial sarcoma: implications for detection of diagnostic tumor translocations.

Fluorescence in situ hybridization studies using non-breakpoint DNA probes were performed to detect the X;18 translocation on 4-microm sections of synovial sarcoma from paraffin blocks. This was done by using commercially available, large target unique sequence DNA probes for regions of the X chromosome short-arm and the 18 chromosome long-arm together with centromere probes for the alternate chromosomes. We determined that such probe combinations could detect the presence of the diagnostic X;18 translocation in interphase cells. Spatial association of dual color signals from the X centromere and the 18 unique sequence probe, as well as between an 18 centromere and the X unique sequence probe, was seen in a significantly higher percentage of synovial sarcoma cells (81.1% +/- 7.7%, confidence interval 95%) than in control nonsynovial soft tissue sarcomas (14.7% +/- 8.3%) and control peripheral blood lymphocytes (5.6% +/- 0.6%). The observed spatial association supports the use of this strategy to detect the X;18 translocation in synovial sarcoma and suggests that this technique could be applied in the diagnosis of other types of tumors with characteristic translocations when histopathological findings are inconclusive. This study is the first report describing the use of nonbreakpoint unique sequence probes for detecting translocations in tumors on paraffin-embedded slides.     

Thyroid control of contractile function and calcium handling in neonatal rat heart

Newborn rats were rendered hyperthyroid (daily subcutaneous injections of L-triiodothyronine, 10 g 100 g^–1 body weight) or hypothyroid (0.05% 6-n-propyl-2-thiouracil in drinking water to nursing mothers) during the first 3 weeks of postnatal life. Compared with the euthyroid group, hyperthyroidism resulted in: (1) cardiac enlargement with right ventricular preponderance, (2) increased cardiac contractile function, (3) increased Ca²⁺ uptake by the sarcoplasmic reticulum (SR), (4) decreased sensitivity to the negative inotropic effect of verapamil and (5) greater inhibition of contractile function by ryanodine. Hypothyroidism generally resulted in opposite changes. The data suggest that the development of the heart and its contractile function during early postnatal life depends on the plasma level of thyroid hormones. In particular, the relative contribution of the SR and sarcolemmal Ca²⁺ transport to the control of cardiac contractility seems to be markedly affected by altered thyroid states. The postnatal maturation of the SR function is accelerated in hyperthyroidism but retarded in hypothyroidism. Consequently, hyperthyroid hearts appear to be less dependent and hypothyroid ones more dependent on trans-sarcolemmal Ca²⁺ fluxes when compared with age-matched euthyroid animals.     

Lipoic acid prevents suppression of connective tissue proliferation in the rat liver induced by n-3 PUFAs. A pilot study

As previously shown, dietary n-3 polyunsaturated fatty acids (n-3 PUFAs) suppress connective tissue proliferation in the rat liver wound concurrent with an elevated level of lipid peroxidation. The present study was undertaken to investigate the influence of alpha-lipoic acid (LA), a natural anti-oxidant, on these effects of n-3 PUFAs. Rats were fed with a commercial pellet diet (control group) or with diets enriched with 10% of sunflower oil (n-6 group) or 10% of fish oil (n-3 group) for 8 weeks followed by addition of LA to the same diets for 10 days. Then a liver thermic wound was induced and the administration of LA was continued for 6 days. The proliferation of the connective tissue, the level of lipid peroxidation and their peroxidizability and the content of prostaglandins E2 and F2alpha were measured in the liver wounds. LA prevented the suppression of connective tissue proliferation in the healing wound induced by n-3 PUFAs, avoided the increase in peroxidation of lipids, reduced peroxidizability of lipids and modulated the decrease in PGE2 and PGF2alpha. The results indicate that dietary LA may prevent the suppression of liver wound healing induced by n-3 PUFAs.     

Homocysteine and red blood cell glutathione as indices for middle-aged untreated essential hypertension patients

OBJECTIVE: Intracellular glutathione in its reduced state is a principal cellular biomolecule with antioxidant activity. Glutathione and homocysteine metabolism are closely associated. As both oxidative stress and hyperhomocystinemia are associated with hypertension, we assessed the relationships between these variables. DESIGN AND SETTING: An observation-based case-control study, performed at a university teaching hospital. PATIENTS: Middle-aged male patients with untreated uncomplicated essential hypertension (mean +/- standard deviation age 53.0 +/- 7.2 years, n = 48) before any treatment and controls with similar age distributions (age 51.6 +/- 5.5 years, n = 28) were evaluated. METHODS: In all subjects, the plasma levels of homocysteine, lipids, creatinine, protein, and glucose were measured. Reduced and oxidized glutathione and folic acid were measured from red blood cells (RBC). RESULTS: The hypertensive patients had decreased levels of red blood cell reduced glutathione (RBC-GSH) and increased levels of oxidized glutathione, which resulted in elevated ratio of oxidized/reduced glutathione as compared to controls (P < 0.001). Plasma homocysteine levels were significantly higher in the hypertensive patients versus the age-matched controls (P < 0.004). In the hypertensive patients, RBC-GSH correlated inversely with systolic blood pressure, serum creatinine, protein and RBC folic acid. No correlation was detected between RBC-GSH and homocysteine. In the controls, RBC-GSH correlated inversely with homocysteine, RBC folic acid and creatinine. According to multiple regression, in the hypertensive patients RBC-GSH was related to systolic blood pressure, hemoglobin, plasma homocysteine, creatinine and protein. Such a relationship was not detected for the controls. CONCLUSION: In untreated hypertensive patients both homocysteine and systolic blood pressure are associated with intracellular oxidative stress as determined by RBC-GSH.     

Antioxidant UPF1 attenuates myocardial stunning in isolated rat hearts

Oxidative stress is a crucial pathophysiological mechanism of myocardial ischaemia-reperfusion injury (IRI). We evaluated the cardioprotective effects of a novel glutathione analogue, UPF1 (4-methoxy-L-tyrosinyl-gamma-L-glutamyl-L-cysteinyl-glycine; MW 483.5), on an isolated rat heart model of thirty-minute global ischaemia followed by 90 min of reperfusion. Treatment with UPF1 (1 mg/ml) prior to ischaemia improved the recovery of post-ischaemic left ventricular end-diastolic pressure (p=0.046), developed pressure (p=0.002) and coronary flow (p=0.01). No protective effect was observed when the hearts were treated with UPF1 after ischaemia. Administration of UPF1 had no influence upon infarct size or enzyme leakage from the heart. The results suggest that glutathione analogue type of biomolecules could possess a therapeutic potential in clinical situations where myocardial IRI is presented as myocardial stunning rather than tissue infarction.