The Effects of Low-Frequency Noise on Rats: Evidence of Chromosomal Aberrations in the Bone Marrow Cells and the Release of Low-Molecular-Weight DNA in the Blood Plasma.

Objectives: Evaluation of the effect of low-frequency noise (LFN) on the frequency of chromosomal aberrations in the bone marrow cells and on the content of low-molecular-weight DNA (lmwDNA) in the blood plasma of rats.

Materials And Methods: A total of 96 male Wistar rats were exposed to either single (17 min session) or multiple (17 min session repeated five times a week for 13 weeks) LFN, with the maximum range below 250 Hz and the sound pressure levels (SPLs) at 120 and 150 dB, respectively. The rats in the control groups were not subjected to any impact.

Comparative Analysis of Harmful Physical Factors Effect on the Cell Genome.

Exposure to either to low-frequency noise or ionizing radiation causes an increase in the number of chromosomal aberrations in the bone marrow cells and the level of low-molecular-weight DNA in the blood plasma of experimental animals. The dynamics of the content of low-molecular-weight DNA increasing after exposure to low-frequency noise and ionizing radiation differs significantly. Both exposures are able to provide a direct damaging effect on DNA.

[Sequencing of low-molecular-weight DNA in blood plasma of irradiated rats].

Extracellular low-molecular-weight DNA in blood of irradiated rats was sequenced for the first time. The screening of sequences in the DDBJ database displayed homology of various parts of the rodent genome. Sequences of low-molecular-weight DNA in rat's plasma are enriched with G/C pairs and long interspersed elements relative to rat genome.

[The clinical aspects of occupational sensorineural impairment of hearing of the acoustic origin].

The objective of the present study was to elucidate the specific clinical features of occupational sensorineural impairment of hearing (OSNHI) depending on the origin of this pathology, viz. noise, infrasound and/or their combination. The review of research concerning this problem made it possible to systematize variants of ODNHI based on the clinical signs taking into consideration the influence of these physical factors.

[Fundamental and applied aspects of preventing the adverse effects of aviation noise].

In the article, aviation noise is discussed as a harmful physical factor with ecological, hygienic, clinical and social implications. Noise contributes to development of general and occupational pathologies, chronic diseases, and reduction of professional longevity. The present-day knowledge of aviation noise sources and dynamics, and effects on environment, population, and aviation personnel is overviewed, as well as strategies to prevent noise consequences, muffling techniques being the key ones.

[The autonomic system reactivity of airport technical personnel using individual protective devices against noise].

The study covered cardiac rhythm variability and hemodynamic parameters in airfield technical personnel under exposure to aviation noise and with use of individual protective measures against noise. Individual protective means remove unfavorable stressful external effects of noise--that is manifested by more stable parameters of sympathetic nervous system activity.

[The potential of tone audiometry for the determination of the sound-absorbing properties of various materials].

The objective of the present work was to experimentally estimate the potential of the tone audiometry technique for the determination of the sound-absorbing properties of various material. The study included 15 subjects at the age from 19 to 32 years. Their audiological examination was followed by the placement of the 5×7 cm spacer plate from the study material beneath the bone vibrator telephone to determine the bone sound-conduction threshold; no air-marking was undertaken.

[The hearing function and vegetative reactions in airport technicians using individual hearing protectors].

The objective of the present study was to evaluate the hearing function in the airport technical personnel and estimate the effectiveness of multicomponent anti-noise hearing protectors used by the specialists engaged in the aircraft maintenance. The tonal threshold audiometry was carried out before and after a shiftwork. The extra-aural effect of noise was assessed from the characteristics of cardiac rhythm variability.

[The value of low-molecular-weight DNA of blood plasma in the diagnostic of the patological processes of different genesis].

The low-molecular-weight DNA appears in blood plasma of irradiated rats, and its content correlates directly with the irradiation dose. Cloning has shown, that enrichment of low-molecular-weight DNA with G+C content and features of its nucleotide sequences point to its ability to form rather stable nucleosomes. DNA obtained after irradiation of rats with principally different doses 8 and 100 Gy differed not only quantitatively, but also by content of the dinucleotides CpG and CpT; this suggests their origin from different sites of genome.

[Impulse noise at shooting from small arms and close combat weapon as the factor of military work].

The high-intensity impulse noise which is basic source in Armed forces are the firearms, has an adverse effect on professional soldiers, leading to decrease of professional working capacity and health deterioration. Due to influence of this factor the considerable part of military men has a hearing impairment and other diseases, including an arterial hypertension. The basic directions of protection of men from impulse noise are: perfection of hygienic rationing, optimization of the using of antinoise earphones, development of new generation of means of individual defense from noise.

[The problems of assessment of the high noise impact on the experts of the Air Force].

Air Force specialists are exposed to high intensity noise levels exceeded the maximum permissible levels. Infrasound as a productive factor in accordance with the general technical requirements (OTT) Air Force-86 is not included in the list of standardized factors. The adverse acoustic environment makes the risk of occupational (sensorineural deafness) and professionally-related diseases of the nervous and cardiovascular systems.

[Hygienic estimation of combined influence of noise and infrasound on the organism of military men].

Hygienic estimation of combined influence of noise and infrasound on the organism of military men. Combined influence of noise and infrasound is accompanied by essential increase of risk of development neurosensory deafness and hypertensive illness. At combined influence of noise and infrasound with a maximum of a spectrum in the field of a sound range the probability of development neurosensory deafness will prevail.

[Assay of extracellular low-molecular DNA in blood as a diagnostic technique for clinical and experimental studies].

It was shown experimentally that ionizing radiation and low-frequency noise increase the level of extracelular low-molecular DNA in rat's blood plasma. Growth of this parameter has been observed in acute stroke patients at the onset of the disease. Low-molecular DNA assay is proposed for evaluation of the unfavorable effects of physical factors on organism.

[Means and methods of acoustic protection in aviation: current status and outlook for development].

Analysis of the current status of acoustic protection in aviation shows that despite the material progress in the field, risk of professional pathologies in flying and technical personnel is still high. The situation is dramatized by the lack of effective personal and crew acoustic protectors. The authors speculate on applicability of innovative materials and technologies, ingenious designs of earphones and modular prefabricated demountable structures.

[Medical and biologic evaluation of individual noise-protection means efficiency].

In laboratory and nature, the authors studied protective properties of experimental models of noise-protection earphones with high acoustic efficiency in broadened frequency range. The article covers expedience of studies at workplaces, including medical and biologic methods that evaluate noise-protection in audible and infra-sound ranges.

[Selective adsorption of endotoxin in the complex treatment of patients with severe sepsis].

Severe sepsis and septic shock remain the most serious problem of critical care medicine today with a mortality of 25-80%. Bacterial endotoxin is of considerable importance in the pathogenesis of sepsis. A selective hemosorbent in which endotoxin adsorption is accomplished via its binding to a synthetic peptide (LPS-A) has been recently designed in Sweden.

[Occupationally mediated morbidity in aviation specialists].

General hygienic evaluation covered workplaces of aviation engineers and technicians and showed that work conditions of these occupations are characterized mainly by exposure to noise and infrasound, that are assigned to hazardous (3.4) and jeopardized (4) classes. Analysis of periodic medical examinations results helped to justify evidence based occupational and occupationally mediated diseases.

[Criteria of noise pathologies in aviation specialists and their prognostic implications].

The paper outlines the criteria of noise pathologies in aviation specialists after extended period of exposure to high-intensity noise and infrared sound. Analysis of morbidity and clinical researches shows prevalence of such pathologies as neurosensory deafness, hypertension and discirculatory encephalopathy. These disorders were correlated with career length.

[Hygienic analysis of conditions of work at the aircraft repair plants and ways to improve the acoustic situation].

Inspection of the conditions of work at aircraft repair plants showed that employees are impacted by a number of harmful in-plant factors including noise, infrasound, kerosene, microclimate and others. Acoustic conditions correspond to harmful (3.2-3.