[Current aspects of harmonization of classification of occupational hearing loss].

The objective of the present work was to develop unified criteria for the evaluation of the severity of noise-induced hearing loss. Current approaches to taking expert decisions based on the results of medical examination of the patients with impaired hearing are substantially different due to the considerable difference between the criteria for the estimation of hearing envisaged by the international classification, occupational pathology classification, and the national system of medico-social expertise. We undertook an attempt to correct and harmonize the existing criteria for the estimation of severity of occupational hearing loss based on the integration of all the three classification in order to "reduce them to a common denominator" and thereby to ensure the basis for the unified diagnostic and expert decisions for the cases of hearing impairment of any etiology.

[The spatial organization of winter bird communities in the East European and West Siberian plains].

The main trends in the territorial changes in winter bird communities and the environmental factors determining them were analyzed based on long-term counts in the East European and West Siberian plains. These trends are reduced to a decline in the winter avian complexes (in the number of species and individuals) in the north- and eastward directions and with a decrease in the degree of sheltering and feed reserves in the habitats associated with reduction in afforestation. The specific regional features of winter East European avian complexes are the larger number of species and individuals in the nemoral forest, forest-steppe, and steppe landscapes, and inland water bodies as compared with the West Siberian avian complexes, as well as an increased influence of the degree of development and agricultural transformation of landscapes.

[The risk of occupational neurosensory loss of hearing in the workers employed in coal and ore mining industries].

This clinico-audiological study included 983 workers engaged in coal and ore mining exposed to combined effect of occupational noise and vibration. Pathogenetic mechanisms underlying the development of occupational deafness were shown to depend on intensity and duration of the action of these factors. Impedancometry was used to evaluate the functional state of the middle ear and to study protective and adaptive potential of ear muscles.

[Peculiarities of the development of occupational deafness in the workers of "noisy" professions employed in experimental mechanical engineering].

The objective of this work was to evaluate the health status and hearing function in the workers employed in experimental mechanical engineering and exposed to the combined effect of noise and occupational psychoemotional stress. The authors describe specific clinico-audiological characteristics of hearing disturbances diagnosed with the help up-to-date highly informative and objective methods for the evaluation of the function of acoustic analyzer, such as impedancometry, threshold tonal high-frequency audiometry, registration of distortion product otoacoustic emission. Criteria for the early diagnosis of neurosensory loss of hearing of < View Article and Find Full Text PDF

[Topical problems of occupational deafness].

The article covers up-to-date state of occupational deafness problem, its importance in occupational therapy. The authors defined topical directions of research in contemporary diagnosis, prognosis and treatment of "noise-related" deafness.

[Overproduction of noncanonical amino acids by Escherichia coli cells].

Overproduction of noncanonical amino acids norvaline and norleucine by Escherichia coli with inactivated acetohydroxy acid synthases was demonstrated. The cultivation conditions for the overproduction of noncanonical amino acids were studied. The effect of the restoration of acetohydroxy acid synthase activity, increased expression of the leuABCD operon, and inactivation of the biosynthetic threonine deaminase on norvaline and norleucine synthesis was studied.

[Effectiveness of nutritional support of elderly and senile of orthopedic traumatological profile].

An analysis of results of the operative treatment of 36 patients who received and did not receive nutritional support in the pre- and postoperative periods has shown that the nutritional support improves the course of the postoperative period.

[Preparation and properties of immobilized riboflavin kinase from Pichia guilliermondii].

Riboflavin kinase (ATP: riboflavin-5'-phosphotransferase, EC 2.7.1.

[Induction of direct mutations of intracellular phage cd exposed to O-methylhydroxylamine].

Intracellular development of DNA-containing cd phage in the presence of O-methylhydroxylamine (in vivo mutagenesis) results in 50-fold increase of mutants in the phage progeny. The main effect is due to the mutagen presence during replication of phage DNA (within 10-20 min after the infection). The presence of the mutagen both before and after DNA replication does not produce any considerable mutagenic effect.

[Reparation of UV-damaged bacteriophage ed].

A repair of UV-damaged phage DNA in the "phage-host" system in accordance with the excision reparative mechanism is demonstrated by means of centrifugation in alkaline sucrose gradient of virulent 3H-thymidine labelled phage sd. The increase of the transfectants quantity of UV-irradiated DNA on uvr+ bacteria compatibly to uvr- bacteria evidences that the bacterial host participates in phage reparation. Caffeine inhibition of UV-irradiated phage sd survival confirms the participation of cell-host in reparation of UV-damaged phage.

[Effect of O-methylhydroxylamine on extracellular phage cd].

Study was made of lethal and mutagenic effect of 1 M and 0,5 M O-methylhydroxylamine (OMHA) on extracellular phage Sd. The correlation between chemical changes of the genome and the degree of phage inactivation under the action of OMHA has been established within the range of studied pH (4,5-7,0) of the reaction medium. OMHA in activates the phage at the highest rate at pH 5,0, which agrees with chemical data indicating that the total rate of OMHA modification of cytidine units is maximal at this pH.