RESUMEN

The paper describes a clinical case of atypical teratoid/rhabdoid tumor with preserved INI1 expression and SMARCA4 gene mutations in an 8-month-old girl. Genome-wide DNA methylation, hierarchical clustering, and next-generation sequencing were used to make a tumor diagnosis. However, BRG1 immunohistochemical examination may be recommended in the routine practice of diagnosis and study of childhood CNS malignant tumors.

Asunto(s)

RESUMEN

The work explores the molecular genetic features of anaplastic astrocytomas and oligodendrogliomas in a series of 43 cases. The mutational status was studied using domestic chemicals and reagent kits. We revealed clear genetic differences between astrocytic and oligodendroglial tumors and proposed an algorithm to study diagnostic and prognostic markers.

Asunto(s)

Asunto(s)

RESUMEN

The energy expenditures in the nonproductive period in the women-workers of the boot and shoe industry (group I) and the sewing industry (group II) were almost similar: in group I it was on an average 1372 +/- 35.4 kcal, in group II--1384 +/- 27.6 kcal. In the productive period the energy expenditures in the workers of group I fluctuated from 1.56 to 2.09 kcal/min, in those of group II--from 1.78 to 2.27 kcal/min. Summary energy expenditures in the productive period comprised 877 +/- 91.1 kcal (in group I), and 949 +/- 51.1 kcal (in group II). Daily energy expenditures were 2249 +/- 77.1 kcal and 2333 +/- 63.9 kcal, respectively. The energy value of the rations of their actual nutrition insignificantly exceeded their energy expenditures (on an average by 120-150 kcal) due to excessive fat consumption, animal fat, in particular. Their rations were characterized by protein, and, to a lesser extent, carbohydrate deficiency, by imbalanced mineral composition and vitamin A, B1, B2, PP and C deficiency. Microsymptoms of vitamin deficiency (mainly those of vitamin C deficiency) were detected in 64% of the examined subjects, excessive weight was found in 23-26% and obesity in 11-16% of the women. The women working at the modern boot and shoe and sewing industry should be referred to the first category of the work intensity, with respect to the energy requirements and the energy value of the nutrient components of their food rations.

Asunto(s)

RESUMEN

Treatment of botulinic neurotoxin A with cyclohexanedione demonstrated that modification of 5 to 10 arginine residues does not change the neurotoxin toxicity, while after modification of 15-20 arginine residues the toxicity is decreased by 40-50% of the original value. Butanedione exerts a stronger detoxicating effect on neurotoxin than cyclohexanedione. The molecular conformation of the modified toxin derivatives and their precipitability upon interaction with antisera against toxin and toxin fragments does not change thereby. The non-toxic derivatives of toxin containing 40 modified arginine residues possess a partial serological affinity for the original toxin in a reaction with antiserum against toxin but do not interact with the antifragment sera. The molecular conformation of these preparations is changed considerably. It is assumed that one or two arginine residues are located near the toxic site of the neurotoxin molecule and are also components of its antigenic determinants. Modification of histidine residues in the neurotoxin molecule by diethylpyrocarbonate is accompanied by a decrease of its toxicity. An additional 10% toxicity is revealed upon modification of 11-13 histidine residues. The molecular conformation of the modified derivatives of neurotoxin and their precipitability do not change thereby. It is probable that 1 or 2 histidine residues are located at or near the toxic site. The data obtained suggest that histidine residues are not localized in antigenic determinants of the neurotoxin molecule.

Asunto(s)

RESUMEN

Photooxidation of botulinic neurotoxin A in the presence of methylene blue is associated with a decrease in toxicity down to complete detoxication. During neurotoxin photooxidation, when the toxicity makes up to 1 to 3% of the original one, the conformation of the neurotoxin molecule and its antigenic properties remain unchanged. Under these conditions, using diethylpyrocarbonate, a specific reagent for histidine, the photooxidized neurotoxin was found to contain 5-6 oxidized histidine residues per molecule of neurotoxin; this was accompanied by changes in the UV absorbance spectrum around 280 nm. It was assumed that the main decrease in neurotoxin toxicity during photooxidation is probably due to oxidation of tryptophane, since the differential UV spectra suggest that the higher the extremum around 280 nm, the greater the decrease of toxicity; chemical modification of histidine residues alone causes no noticeable detoxication.

Asunto(s)

RESUMEN

Using spectrophotometric titration of botulinic neurotoxin A by N-bromosuccinimide, the oxidation of one tryptophane residue was shown to induce an almost complete detoxication of the toxic protein. The conformation of the toxin molecule remained thereby unchanged, as well as the precipitation capacity of the modified toxin after oxidation of two tryptophane residues. The toxin with three or more modified tryptophane residues did not produce precipitation bands with antiserum against original toxin. Nitration of the tyrosine residues in the neurotoxin molecule with tetranitromethane gradually decreased its toxicity. All nitrous derivatives of toxin (both toxic and non-toxic ones) containing 2-18 modified tyrosine residues revealed a precipitating capacity in a reaction with antiserum against original toxin and anfragment sera. The non-toxic toxin nitrous derivatives with 15-18 modified tyrosine residues possessed partial serological affinity for original toxin in a reaction with antiserum against toxin and did not interact with antisera against toxin fragments. The conformation of molecules of toxin nitrous derivatives with 4-5 modified tyrosine residues was not changed irrespective of a 80% loss of the enzyme toxicity.

Asunto(s)

RESUMEN

A limited proteolysis of the botulinic toxin of A type by subtylopeptidase A resulted in two high molecular weight non-toxic fragments. The peptide with mol. weight of 100,000 is made up of two subunits with mol. weights of 52,000 and 48,000. The second peptide whose mol. weight is 40,000 is a single-chained one. The high molecular weight peptide has one S--S bond and two SH-groups, whereas the one with a lower molecular weight--no S--S bond and 1.3--1.5 SH-groups. Dansylation of the first fragment revealed two N-terminal amino acids (histidine, arginine) in toxin, which suggests the localization of the first fragment at the N-end of the toxin molecule. Using immunochemical analysis with monospecific antiserum against original toxin and antifragment sera, the antigenic determinants from the fragments were shown to be serologically different. A structural model of botulinic toxin of A type is proposed.

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)