RESUMEN

Concentration of organochlorine pesticides (OCPs) (α-, ß-, γ- hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethane (DDD), dichlorodiphenyldichloroethylene (DDE)) in four species of Pacific salmon (pink, chum, chinook, and sockeye) are presented. OCPs in salmon organs increased in the following order: muscle < liver < eggs < male gonads. Concentrations of the OCP in salmon organs increased in following order: DDE < γ-HCH < α-HCH. The level of pollutants in salmon is compared with the sanitary and epidemiological norms of Russia and other countries. Cancer and noncancer hazard ratios through consumption of salmon in Russian Far East for both men and women also were summarized. Noncancer and cancer hazard ratio values were far below threshold values (<1.0).

Asunto(s)

RESUMEN

The regeneration of longitudinal muscle bands (LMBs) in the sea cucumber Stichopus japonicus was studied using light and electron microscopic and immunocytochemical methods. Previous investigations of holothurian organs showed the presence of some cytoskeletal proteins which were specific for LMBs only. One of them, the 98 KDa protein, was isolated by means of SDS-electrophoresis and used as an antigen to obtain polyclonal antibodies. When tested on paraffin sections of sea cucumber organs, the antibodies were shown to interact only with coelomic epithelial cells covering the LMBs. The antibodies were used to study LMB regeneration after transverse cutting. During regeneration no signs of myocyte dedifferentiation or mitotic division were observed. In the wound region, damaged myocytes degenerated and muscle bundles desintegrated. However, the coelomic epithelial cells dedifferentiated and began to invade the LMB. Just beneath the surface these cells formed clusters (muscle bundle rudiments). The number and size of the clusters gradually increased, the cells lengthened and developed contractile filaments. These observations suggest that new muscle bundles arise from coelomic epithelial cells covering the LMBs. The migration of coelomic epithelial cells into the damaged LMBs and their myogenic transformation are the basic mechanism of holothurian muscle regeneration.

RESUMEN

We propose simple model for the mechano-biochemical cycle of the myosin cross-bridges, taking into account the contribution of "slow binding" bridges in the negative strength. Mathematical analysis of this model allows us to obtain an analytical expression for the dependence of the contraction velocity on the MgATP concentration. Parameters of this equation are rate constants of dissociation of "slow binding" bridges from thin filament, liberation of inorganic phosphate and binding of MgATP. The model leads to the bell-shaped dependence of myofibrillar contraction velocity on the substrate concentration similar to the experimental one. The values of above mentioned constants for the isolated myofibrils are estimated to be close to values obtained in unstructured contractile models.

Asunto(s)

Asunto(s)

RESUMEN

Hungarian public health services are experiencing changes the purpose of which is to establish fixed and guaranteed receipt of financial resources for public health and social welfare, to entrust health insurance bodies with power to command credits, to change the mechanism of financing public health institutions. It is expected that hospitals would be financed on the basis of national system of DRGs being developed since 1986 or according to the principle of "fee-for-service". The Hungarian experience indicates that the changeover from the state system of public health to the insurance medicine requires some time.

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

Aggregation of contracted myofibrils was studied as a function of experimental conditions at myofibril contraction. The aggregation rate increased at higher concentrations of suspensions and at increased ionic strength of the medium to achieve the maximum at 0.1 M KCL in the last case. The aggregate sizes grow with an increase of ionic strength and concentration of MgATP and reduce with addition of F-actin. Aggregation of myofibrils develops only in the case of their complete or significant contraction. It was suggested that aggregation is stimulated by dehydration of myofibril at contraction.

Asunto(s)

RESUMEN

The state of the network of cost-accounting medical facilities, their role and place in the system of medical paid services for the population are described. The work, economic and fiscal activities of Moscow cost-accounting medical facilities are analyzed. Measures aimed at further improvement of medical facilities providing paid services to the population are proposed.

Asunto(s)

RESUMEN

Socio-economic basis for spending per resident is presented as a normative indicator and the technique for its determination is given as illustrated by the expenditure on public health establishments of the Moscow Main Department of Public Health in 1988.

Asunto(s)

RESUMEN

The necessity of planning the hospital network (bed capacity and its structure) in combination with social security institutions is validated. Thus, planning of the hospital network should be carried out in combination with social security institutions, the degree of development of other forms of medical services (hospitals at home, day hospitals, curative and diagnostic complexes, etc.) being taken into account. By preliminary estimates the demand for hospital beds is 127 per 10,000, 13 for chronic patients and the elderly in medicosocial facilities, 38.9 in social security institutions. Realization of the principles of differentiated hospital treatment of patients according to the degree of its intensity enables one to use hospital resources more effectively and to raise the quality of inpatient care. It is recommended to differentiate specific investments in hospital construction (25,000-70,000 rubles per a bed) according to the demand in hospital beds at different stages of treatment intensity and hierarchial level of medical care organization. Equal possibilities in the provision of inpatient care for the whole population can be achieved within the framework of unified regional models of the network of health care facilities, based on the standard target approach to the utilization of hospital resources.

Asunto(s)

RESUMEN

The loss of Ca2+-sensitivity by natural actomyosin (desensitisation) after treatment with low ionic strength solutions results in marked deceleration of protein superprecipitation. This phenomenon is not due to the removal of minor proteins, since a similar effect was observed during "desensitisation" of synthetic actomyosin containing only myosin and actin. However, addition to desensitised actomyosin of tropomyosin, especially in combination with alpha-actinin markedly restores the initial parameters of superprecipitation and ATPase activity. It was assumed that desensitisation has a direct modifying influence on actomyosin, whose effect is weakened in the presence of tropomyosin and alpha-actinin.

Asunto(s)

RESUMEN

Studies have been made on the distribution of phospholipids between rhodopsin and free lipids of photoreceptor membranes of the outer segments of retinal rods from cattle, frog Rana temporaria and fish Teragra chalcogramma. comparative investigation of fatty acid composition of phospholipids from rhodopsin microboundary and lipid bilayer in photoreceptor membranes was made as well. Amino phospholipids from rhodopsin microboundry were revealed using glutaraldehyde. This reagent by means of its aldehyde groups links phospholipid amino groups with amino groups of proteins of photoreceptor membranes. After this treatment, free phospholipids of lipid bilayer were extracted from photoreceptor membranes by methanol-chloroform mixture. It was demonstrated that fatty acid composition of phospholipids of lipid bilayer differs from that of amino phospholipids from rhodopsin microboundary. In the animals investigated, fatty acids of phospholipids from lipid bilayer were found to be more unsaturated than fatty acids of amino phospholipids from rhodopsin microboundary. This difference was more pronounced in photoreceptor membranes from the frog and fish than from cattle.

Asunto(s)

RESUMEN

PIP: The decline in mortality that occurred in the USSR up to 1960 is first described. The reasons why this decline has not continued in recent years and why mortality has even increased in certain age groups are then considered. The solution to the problem of increasing mortality is sought in an improvement in Soviet health services in order to increase life expectancy in general and the length of economically active life in particular.^ieng

Asunto(s)

Asunto(s)

RESUMEN

Using polyacrylamide gel electrophoresis in the presence of Na-SDS, the oligomerization of membrane proteins of the retinal rod outer segments of the frog and the wall-eyed pollock and of rabbit skeletal muscle sarcoplasmic reticulum was studied. It was shown that under storage of the retinal rod outer segments the rhodopsin oligomerization is inhibited by the lipid peroxidation inhibitor--ionol. Similar oligomerization was observed under induction of lipid peroxidation in the membranes; the accumulation of the lipid peroxidation product--malonic dialdehyde--was accompanied by disappearance of the rhodopsin monomeric form in the outer segments. The cross-linking agent--glutaric dialdehyde--also causes oligomerization of the rhodopsins. Similar aggregation is also characteristic of the major protein of the sarcoplasmic reticulum fragments, i. e. Ca2+-dependent ATP-ase. Thus, one of the main changes in the protein content of biomembranes under lipid peroxidation is the oligomerization of integral proteins due to their interaction with bifunctional reagents, i. e. lipid peroxidation products.

Asunto(s)

RESUMEN

Using gas-liquid and column chromatography, the carbohydrate composition of the visual protein rhodopsin from wall-eyed pollock purified by SDS-electrophoresis was studied. It was found that similar to bovine rhodopsin, the protein from wall-eyed pollock contains in its carbohydrate moiety only two types of monosaccharides, i. e. mannose and glucosamine (1,78 +/- 0,13 moles of mannose per one mole of glucosamine). One mole of rhodopsin contains 9,43 +/- 1,5 moles of mannose and 5,3 moles of glucosamine. The data obtained suggest a similarity of the carbohydrate component of wall-eyed pollock rhodopsin to that of the traditional object--bovine rhodopsin. Possible functions of the carbohydrate component of rhodopsin in the photoreceptor membrane are postulated.

Asunto(s)

RESUMEN

Using SDS-electrophoresis, it was shown that the addition of sodium ions to the solubilization medium causes oligomerization of wall-eyed pollock rhodopsin. Oligomerization is also caused by solubilization of the wall-eyed pollock rod outer segments by sodium cholate (deoxycholate), by changes in SDS concentration as well as by an increase of protein content in the solubilization mixture, freezing of solubilizate and treatment of the rod outer segments by sodium borohydrate upon illumination. Possible causes of wall-eyed pollock rhodopsin aggregation are discussed.

Asunto(s)

Asunto(s)

RESUMEN

Fragmentation of wall-eyed pollock and bovine rhodopsins by papain in the photoreceptor membrane was studied by sodium dodecyl sulfate electrophoresis. A scheme of step-wise rhodopsin proteolysis is presented. The molecular weights and localization of the carbohydrate and chromophore components of the fragments formed were determined. The data obtained suggest that the photoreceptor membranes of both rhodopsins contain three sites accessible to water environment and are indicative of topographical similarity of the rhodopsins.

Asunto(s)