Previously Unclassified Mutation of mtDNA m.3472T>C: Evidence of Pathogenicity in Leber's Hereditary Optic Neuropathy.

Leber's hereditary optic neuropathy (LHON) refers to a group of mitochondrial diseases and is characterized by defects of the mitochondrial electron transport chain and decreased level of oxidative phosphorylation. The list of LHON primary mtDNA mutations is regularly updated. In this study, we describe the homoplasmic nucleotide substitution m.3472T>C in the MT-ND1 (NADH-ubiquinone oxidoreductase chain 1) gene and specific changes in cell metabolism in a patient with LHON and his asymptomatic sister. To confirm the presence of mutation-related mitochondrial dysfunction, respiration of skin fibroblasts and platelets from the patient and his sister was studied, as well as the mitochondrial potential and production of reactive oxygen species in the skin fibroblasts. In addition, based on characteristics of the toxic effect of paraquat, a new approach was developed for detecting the functional activity of complex I of the mitochondrial respiratory chain.

[Change of isoforms' spectrum of alpha-L-fucoside secreted by affected cells in some hereditary lysosomal diseases]. / Izmenenie spektra mnozhestvennykh form alpha-fukozidazy, sekretiruemoí kletkami-misheniami pri nekotorykh nasledstvennykh énzimopatiiakh.

In vitro it was studied the isoform spectra of the intracellular and secreted alpha-L-fucosidase from skin fibroblasts of patients with Fabry disease (glycolipidosis), Hurler and Sanfilippo D diseases (mucopolysaccharodosis, types I and III) and in the normal state was studied. It was shown that the multiple form profile of secreted alpha-L-fucosidase in patients fibroblasts was changed as compared to that in control: the pathological cells were characterized by expression of more basic isoforms of alpha-L-fucosidase. The changes were similar to those in sucrose-loaded normal cells, modelling storage disease. The data obtained allow the suggestion that the intracellular accumulation of compounds whose hydrolysis was disturbed on a hereditary deficiency of enumerated glycosidases can influence the posttranslational processing of alpha-L-fucosidase, the enzyme which is not primary affected in these disorders. These data allow the conclusion that the high phenotypic heterogenity of lysosomic storage diseases is possibly due to the influence of so-called epigenetic factors involving the changes in properties of such glycosidases as are not associated with a primary hereditary defect.

[Experimental criteria for interpretation of bacterial sensitivity to dioxidine determined by diffusion from the disks]. / Eksperimental'nye kriterii dlia interpretatsii chuvstvitel'nosti bakterii k dioksidinu metodom diffuzii iz diska.

Antibacterial activity of dioxidine against aerobic and facultative anaerobic organisms under conditions of anaerobiosis i. e. conditions really observed for example in abscess cavities or necrotic tissues is 30 to 100 times as high as that under aerobic conditions. There is a relationship between sensitivity of bacteria to dioxidine under aerobic and anaerobic conditions which is expressed by the regression equation. Therefore, comparison of the MICs determined under anaerobic conditions with the growth inhibition zones formed by disks with the drug under aerobic conditions is possible. The MIC of dioxidine was determined under anaerobic conditions for 179 clinical strains of aerobic and facultative anaerobic bacteria and the growth inhibition zones of the same bacteria under aerobic conditions were evaluated with the use of disks containing 100, 75, 50, 25, 20, and 15 micrograms of the drug. The border line. MIC differentiating between resistant and sensitive strains was chosen to be equal to 4 micrograms/ml. Differentiation of the strains into sensitive and resistant ones by the values of the growth inhibition zones was performed with the method of error minimization described by C. Metzler and R. De Haan in 1974. Disks containing 25 micrograms of the drug allowed one to differentiate the strains under aerobic conditions into sensitive and resistant ones: the growth inhibition zones greater than 11 mm corresponded to the sensitive strains (the MIC smaller than 4 micrograms/ml) and the growth inhibition zones smaller than 11 mm corresponded to the resistant strains (the MIC greater than 4 micrograms/ml).

[Pharmacokinetics of dioxidine in oncological patients in the postoperative period]. / Farmakokinetika dioksidina u onkologicheskikh bo'lnykh v posleoperatsionnom periode.

Dioxidine pharmacokinetics was studied in 5 patients operated for cancer of the large intestine and treated prophylactically with the drug during the postoperative period. Dioxidine was administered intravenously for 10 minutes twice a day in an amount of 300 mg in 5 per cent solution of glucose. The drug concentrations in serum and urine were determined with a microbiological procedure. Escherichia coli AB 2472 rec A16, a strain deficient with respect to reparation was used as a test microbe. The plates with the dilutions were incubated under anaerobic conditions. The time course of the drug concentrations in serum was shown to be satisfactorily described by the following equation: C(t) = 3.125 . 1-2.57.t + 2.76 . 1-0.64.t. Within the first 1.5-2 hours after the administration the dioxidine concentrations in serum and urine amounted to 2.5-4 and 35-50 micrograms/ml respectively.

[A microbiological test system for determining dioxidine levels in biological fluids]. / Mikrobiologicheskaia test-sistema dlia opredeleniia kontsentratsii dioksidina v biologicheskikh zhidkostiakh.

A microbiological procedure for determining dioxidine concentrations in biological fluids with using E. coli AB 2472 rec A 16, a reparation deficient strain as a test organism is described. Cell suspension of the strain 24-hour culture is added to 1.2 per cent agar with Hottinger digest (140 mg per cent of amine nitrogen), 3 g/l of disubstituted sodium phosphate and 0.4 per cent of glucose cooled to 50 degrees C. 10 ml of the medium are added to every Petri dish with metallic cylinders put on the agar. After the medium solidification the cylinders are removed and 0.1 ml of the solution being tested is added to every well. The dishes are incubated for 24 hours under anaerobic conditions. The test system sensitivity is 0.2 microgram/ml of dioxidine. The relationship between the growth inhibition zone and the drug concentration is linear within dioxidine concentrations of 0.2 to 3.2 micrograms/ml.