OCRL1 mutation in a boy with Dent disease, mild mental retardation, but without cataracts.

BACKGROUND: Oculocerebrorenal (Lowe) syndrome is an X-linked multisystem disease characterized by renal proximal tubulopathy, mental retardation, and congenital cataracts. We present a 19-year-old boy who was found to have low molecular weight proteinuria, hypercalciuria, mild generalized hyperaminoaciduria and intermittent microscopic hematuria at the age of 3. METHODS: Standard clinical and biochemical examinations and mutational analysis of the CLNC5 and OCRL1 gene were performed for the patient. RESULTS: The patient fulfilled diagnostic criteria for Dent disease, but lacked mutation in CLCN5. Sequencing of candidate genes revealed a mutation in his OCRL1 gene, which encodes for enzyme PIP2 5-phosphatase. The enzyme was not detected by western blot analysis, and decreased activity of the enzyme PIP2 5-phosphatase was observed in cultured skin fibroblasts. The boy had only mild mental retardation, mildly elevated muscle enzymes, but no neurological deficit or congenital cataracts, which are typical for Lowe syndrome. CONCLUSIONS: Children with Dent phenotype who lack CLCN5 mutation should be tested for OCRL1 mutation. OCRL1 mutations may present with mild clinical features and are not necessarily associated with congenital cataracts.

Erythrocyte antioxidant enzymes in patients with alcohol dependence syndrome.

BACKGROUND: The role of free radicals and hydrogen peroxides in the metabolism and toxicity of alcohol is supported by many studies, therefore, many autors have tried to use the enzymes, metabolizing highly reactive chemical compounds as biological markers of alcoholism. METHODS: Erythrocyte antioxidant enzymes were measured in 37 male patients with alcohol dependence syndrome, without severe liver disease, aged between 18 and 59 years, with different duration (years) of alcohol abuse. RESULTS: Superoxide dismutase (SOD) activity was statistically significantly increased in alcoholics. Glutathione peroxidase (GPX) activity has shown no significant difference in alcoholics compared to the control group. Catalase (CAT) activity was significantly decreased in alcoholics. Specific activity of CAT was positively correlated with the duration of alcohol abuse (years). CONCLUSIONS: Catalase activity has shown statistically significant decrease in patients with alcohol dependence syndrom. (Tab. 3, Fig. 4, Ref: 31.)

Erythrocyte superoxide dismutase, glutathione peroxidase and catalase activities in healthy male subjects in Republic of Macedonia.

OBJECTIVES: The study was aimed to establish the reference values for erythrocyte antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) in healthy male subjects, as well as to detect their relation to age, cigarette smoking, moderate alcohol consumption, antiinflammatory drugs and supplements use and the possible correlation between individual parameters. BACKGROUND: Superoxide dismutase, glutathione peroxidase and catalase are the three main enzymes that control the biological effects of the reactive oxygen species (free radicals). METHODS: The authors have examined 111 healthy male blood donors aged 18-59 years. All studied enzymes were assayed in erythrocytes by manual techniques. The results were statistically evaluated by means of the ANOVA programme. RESULTS: The group of healthy individuals had a large dispersion of interindividual activities of antioxidant enzymes. Age, cigarette smoking, antiinflammatory drugs and dietary supplements use had no significant effect on the antioxidant enzymes activity. The activity of the enzymes showed normal Gaussian distribution. We established mean reference values for SOD, GPX and CAT activity. SOD negatively correlated with CAT (r=-0.199). CONCLUSIONS: We established the reference values for erythrocyte SOD, GPX and CAT activity in male subjects. The large dispersion of activities of the investigated enzymes in healthy individuals does not allow to make a standard use of these parameters in clinical practise without establishing "own reference values" for each laboratory. (Tab. 2, Fig. 4, Ref. 31)

Effect of angiotensin II type 1 (AT1) receptor antagonist on the endothelial dysfunction in spontaneously hypertensive rats in correlation with the nitric oxide system.

BACKGROUND: Hypertension is associated with impaired endothelial function, which can be explained by a decrease in nitric oxide (NO) generation or by an enhanced inactivation of NO after its release from endothelial cells. OBJECTIVES: The aim of this study was to investigate the effect of long-term treatment with losartan, an angiotensin II (AT1) receptor antagonist, on endothelial dysfunction in an animal model of hypertension in relation to the nitric oxide system. METHODS: Losartan was administered to 48 sixteen-week-old spontaneously hypertensive rats, in a dose of 10 mg/kg bw/daily in drinking water, for 12 weeks. Systolic blood pressure (SBP) was measured at the beginning, after 4, 8 and 12 weeks of treatment, by the tail-cuff plethysmographic method. At each mentioned time point, a group of 12 animals was sacrificed and blood was withdrawn from the abdominal aorta. Plasma samples were used for determination of total nitrate/nitirite levels, cyclic guanosine monophosphate (cGMP) and endothelin (ET) 1 levels. Statistical evaluation of the results was performed by the use of a computer statistical programme Statistica for Windows 5.0. RESULTS: Losartan produced a significant decrease of SBP at all time points. On the other hand, long-term treatment with this AT1 receptor antagonist produced a significant increase of nitrate/nitrite and cGMP plasma levels. When we compared the values of SBP with plasma nitrate/nitrite as well as with cGMP values, a statistically significant correlation was established. A statistically significant decrease in plasma endothelin 1 values was found during the whole study period. Also, a positive correlation between SBP and plasma endothelin 1 concentrations was observed. CONCLUSIONS: Long-term losartan (AT1 receptor antagonist) treatment, apart from its blood pressure lowering effect in hypertension, has beneficial effects on the endothelial dysfunction which is at least partially due to the activation of the nitric oxide system. (Tab. 1, Fig. 2, Ref. 33.)

Stress tolerance test and SDS-PAGE for the analysis of urinary proteins in children and youths.

Excretion of urinary proteins (UP) is an important marker for the evaluation of patients with progressive renal disease. In order to analyze quantitative and qualitative variability of UP in relation to physical activity, we used standardized stress tolerance test and SDS-PAGE. Five urine samples were obtained from each patient at rest, during ordinary daily activity and after physical stress. Determination of total proteins was performed using Meulman's classic method with sulfosalicylic acid. UP were separated by ultrathin horizontal gradient SDS-PAGE according to Görg. There were 142 patients; 40 with poststreptococcal glomerulonephritis (PSGN), 11 with diabetes mellitus, 16 with chronic pyelonephritis and 75 who attended for investigation of asymptomatic proteinuria. Functional proteinuria was established in 42 subjects, who displayed maximal UP excretion during stress and the presence of apolipoprotein AI on SDS-PAGE. Children with PSGN showed no significant increase of UP during stress. Some children with diabetes mellitus (27%) and chronic pyelonephritis (47%) displayed microproteinuria or overt proteinuria after stress. Quantitative and qualitative changes in total UP excretion can be detected by stress tolerance test and SDS-PAGE. It remains to be seen whether stress tolerance test can identify children and youths who are at higher risk for disease progression.

Difference between orthostatic and march functional proteinuria by application of stress tolerance test and SDS-PAGE.

We introduced minimal necessary criteria and methods for noninvasive laboratory diagnosis and follow-up of functional proteinuria in youths: stress tolerance test, determination of total urinary proteins (TP) and their separation and identification with gradient SDS-PAGE. Renal functional adaptability in conditions of complete rest, in routine daily activity and after several hours of active physical effort has been evaluated by the tolerance test. Excretory urinary proteins, as the most appropriate markers, were analyzed with noninvasive methods. Excretory TP demonstrated the quantity and dynamics of the proteins excreted during the tolerance test. Separation with gradient (4-22.5%) SDS-PAGE provided differentiation of functional proteinuria from the other orthostatisms, through the protein fractions present and the constant finding of apolipoprotein AI. The investigation comprised 19 youths with orthostatism and 20 healthy subjects without orthostatism, all between the age of 10 and 18 years. The subjects without orthostatism excreted proteins in normal limits during the stress tolerance test. SDS-PAGE of the urinary samples, obtained during the tolerance test, in five subjects significantly differed from that in the other 14 subjects. According to the protein fractions present as well as from the dynamics of the protein excretion, orthostatism in these five subjects probably originated from organ structural lesions. In the other 14 subjects functional proteinuria was present, but there were differences among them in the dynamics of the appearance and disappearance of the orthostatism, which has been used for arbitrary division of the orthostatic and the so-called march-proteinuria.