[Molecular diagnosis and frequencies of primary hypolactasia in populations of RUSSIA and neighboring countries].

The digestion of the milk sugar (lactose) is observed every normal child but not in every adult. The decreased lactase synthesis in some adults results in problems with digestion of the whole milk (primary hypolactasy). An association of lactase activity in adults with carrying of the allele T within the polymorphism C/T-13910 located upstream of the lactase gene and 100% association of hypolactasy with the genotype C/C has recently been shown for a Finnish sample. In the present work we determined the LCT* C/T_13910 genotypes and allele frequencies in populations from Russia. The genotype C/C frequencies varied from 36.6% for Russians to 88.2% for Chukchi and were close to the published medical and epidemiological data on hypolactasy frequencies in respective populations. Genotyping was performed by three different methods to identify the optimal one. Our results have shown that the studied locus is the key determinant for the primary hypolactasy development in various human populations. Consequently, the DNA diagnostics of the C/C genotype carrying is a promising predictive test to detect the primary hypolactasy long before its clinical development. Practical application of this type of diagnostics would be a step towards the individual-oriented medicine.

[Hormonal response of the bodies of cosmonauts after completion of brief space flights]. / Gormonal'naia reaktsiia organizma kosmonavtov posle zaversheniia kratkovremennykh kosmicheskikh poletov.

After short-term (7-day) space flights the following parameters were measured in blood of cosmonauts: cortisol, ACTH, aldosterone, thyrotropic hormone, thyroxine, triiodothyronine, somatotropic hormone, insulin, testosterone, cyclic nucleotides, prostaglandins, activities of the kallikrein-kinin, fibrinolytic and coagulatory systems, and plasma renin activity; in addition, renal excretion of aldosterone and total 17-oxycorticosteroids was determined. It was demonstrated that after the short-term flights the acute period of adaptation was accompanied by a moderate activation of the renin-angiotensin-aldosterone system, adrenal glucocorticoid function, pancreatic insular apparatus, kallikrein-kinin system as well as increased cyclic AMP which is suggestive of a moderately expressed stress-reaction.

[Metabolic processes in rat skeletal muscle after a flight on the Kosmos-936 biosatellite]. / Sostoianie protsessov metabolizma v skeletnykh myshtsakh krys posle poleta na biosputnike "Kosmos-936".

The study of skeletal muscles of rats flown on Cosmos-936 demonstrated different metabolic reactions in muscle fibers of different function and type to weightlessness and Earth gravity. The data obtained gave evidence that artificial gravity may considerably prevent metabolic changes in muscles developing in response to specific effects of weightlessness.

[Protein fractions and their enzyme activity in the rat myocardium in a Kosmos-936 biosatellite experiment]. / Belkovye fraktsii i ikh fermentativnaia aktivnost' v miokarde krys v éksperimente na biosputnike "Kosmos-936".

The effect of artificial gravity on protein fractions and their enzyme activity in the myocardium of rats flown on board Cosmos-936 was studied. In weightless rats the content of sarcoplasmic proteins increased at R + O and that of T fraction proteins decreased at R + 25. In centrifuged rats such changes were not seen. In centrifuged rats the enzyme activity of sarcoplasmic proteins did not alter. In weightless rats ATPase activity of myosin decreased significantly, and in centrifuged rats it remained almost unchanged.

[Skeletal muscle mixed fiber tissue metabolism in rats after a flight on the Kosmos-690 biosatellite]. / Metabolizm tkani smeshannykh po tipu volokon skeletnykh myshts u krys posle poleta na biosputnike "Kosmos-690".

On the R+O day the quadriceps muscle of rats showed a decrease in the content of T protein and an inhibition of LDH activity of sacroplasmatic proteins. These changes resulted from the combined affect of space flight factors and gamma-irradiation, and may be considered as a decline of compensatory synthetic processes responsible for the recovery of muscle proteins in weightlessness. Inhibition of the age-associated shift of the M:H ratio of LDH found on the R+25 day can be attributed to the inhibitory effect of gamma-irradiation. No change in the content of glycogen in the gastrocnemius muscle of flight rats was noted.

[Changes in the soleus muscle tissue metabolism of rats after a flight on the Kosmos-690 biosatellite]. / Izmeneniia metabolizma tkani kambalovidnoi myshtsy u krys posle poleta na biosputnike "Kosmos-690".

The soleus muscle of flown rats did not show any effect of gamma-irradiation on the composition and enzymic activity of protein fractions. On the Ist postflight day a significant decrease in the content of myofibrillar and sarcoplasmatic proteins in the soleus muscle was found. Besides, a drastic increase in the activity of aspartate aminotransferase and lactate dehydrogenase of sarcoplasmatic proteins and an atrophic type change in the LDH pattern were demonstrated. Those changes were similar to the weighttlessness-induced processes of atrophy and dystrophy and proved reversible.

[Protein fractions and their enzymatic activity in the rat myocardium after a flight on the Cosmos-690 biosatellite]. / Belkovye fraktsii i ikh fermentativnaia akivnost' v miokarde krys posle poleta na biosputnike "Kosmos-690".

Gamma-irradiation of rats in the ground-based experiment decreased the activity of aspartate aminotransferase of sarcoplasmatic proteins of the myocardium and increased the activity of adenosine triphosphate of myosin of the myocardium 1 and 26 days post-test. Gamma-irradiation of flight rats also reduced the activity of aspartate aminotransferase of sarcoplasmatic proteins of the myocardium; however, the activity of ATPase of myosin of the myocardium was lowered both 1 and 26 days postflight. It is suggested that irradiation-induced inhibition of synthetic processes delayed the synthesis of myosin with a normal activity and diminished the protein content in the T fraction of myocardium on the 1st postflight day.

[Protein fractions and their enzyme activity in rat myocardium after a 22-hour space flight]. / Belkovye fraktsii i ikh fermentativnaia aktivnost' v miokarde krys posle 22-sutochnogo kosmicheskogo poleta

No significant changes in the content of sarcoplasmatic and myofibrillar proteins were found in the myocardium of rats that made a 22-day flight onboard the biosatellite. On the 2nd and 26th postflight days the activity of aspartate and alanine aminotransferases of sarcoplasmatic proteins was increased and the total activity of lactate dehydrogenase and its isoenzyme spectrum remained unchanged. On the 2nd postflight day the ATPase activity of myosin of the myocardium was substantially lowered and on the 26th postflight day it returned to the normal. This decline in the ATPase activity of myosin can be regarded as an adaptive reaction to weightlessness.