[Compensatory and adaptive mechanisms in children with congenital multiple arthrogryposis in the absence of active flexion in the elbow joint]. / Kompensatorno-prisposobitel'nye mekhanizmy u detei s vrozhdennym mnozhestvennym artrogripozom s otsutstviem aktivnogo sgibaniya v loktevom sustave.

Arthrogryposis is one of the most severe congenital orthopedic diseases, characterized by multiple joint contractures, hypoplasia or aplasia of the skeletal muscles of the extremities, as well as severe motor disorders. The use of compensatory strategies allows patients to improve the ability to self-care. OBJECTIVE: To study the compensatory strategies in children with arthrogryposis with absent of active flexion in the elbow joint and estimate their dynamic after surgical treatment. MATERIAL AND METHODS: We performed a clinical examination of 236 patients with arthrogryposis with deformities of the upper extremities due to arthrogryposis at the age of 10 months to 16 years. The examination was carried out before the operation, as well as at various times (from 1 month to 8 years) after. In 87 cases (67 patients), restoration of active elbow flexion was performed by transposition of latissimus dorsii or pectoralis major to the biceps position. The activity of the muscles involved that most commonly used in compensatory strategies (synergy of m. biceps brachii and m. deltoideus or m.biceps brachii and m. quadriceps femoris) in 10 patients (from 3 to 10 y.o.), was evaluated before and after (from 2 months to 2 years) surgery by surface electromyography. RESULTS: It was found that children's compensatory strategies are formed at the age of 6 months to 1 y.o.6 months after surgery, the using of compensatory strategies becomes more rare, and 12-18 months after surgery, when the strength of the forearm muscles was 4 points, they were not used at all. CONCLUSIONS: Compensatory strategies in children with the absence of active and preservation of passive flexion in the elbow joint are diverse. They depend on the amplitude of passive and active movements in the shoulder, the function of the hand and deformities of the lower extremities. These strategies in children with arthrogryposis are unstable and completely disappear when active movements in the elbow joint are restored in the functional range.

[Mitochondrial and lysosomal pathways of death of hepatocytes of lamprey Lampetra fluviatilis L].

Mechanisms of mitochondrial and lysosomal pathways of natural cell death in lamprey hepatocytes at the spring period of prespawning migration are described. The mitochondrial pathways (release of cytochrome c from mitochondria into cytosol and activation ofcaspases) operates according to the classical scheme known for apoptosis. The lysosomal cell death pathway connected with activation of cathepsin B has been revealed quite recently in cells in pathologies, in particular at obstruction of gallbladder and bile ducts. The peculiarity of lamprey hepatocytes consists in biliary atresia (the absence both of gallbladder and of bile ducts) in liver of adult animals. Thereby the lamprey hepatocytes represent an excellent object for study of this new pathway of cell death. We have revealed a parallel development of the mitochondrial and lysosomal pathways of cell death of lamprey hepatocytes.

[Bioenergetics of the lower vertebrates. Mechanisms of adaptations to anoxia and hypoxia].

In this review, causes of tremendous differences in respiration and oxidative metabolism between the homoiothermal and poikilothermal vertebrates are discussed. Tissues of the latter contain not lower, and sometimes even higher amount of mitochondria with the powerful potential of oxidative enzymes, as compared with the homoiothermal vertebrates; this potential is realized only by 3-4% because of a low rate of oxygen transport due to peculiarities of the cardiovascular system of the lower vertebrates. Limitation of ATP synthesis is responsible for a specific structure of plasma membranes with the essentially lower amount of channels for the passive ion leakage as compared with the mammalian plasma membranes. Examples are presented of the homoiothermal animal cells (the frog olfactory receptor cell) that contact with environment without mediation of the blood circulation system and have the energy metabolism level comparable with that of mammalian cells. Examples of energetic aromorphosis are tunas with heat exchangers in several organs and with a powerful system of oxygen delivery to cells; owing to this, intensity of their oxidative metabolism could reach that of the higher terrestrial vertebrates. The closing part of this paper describes the molecular mechanisms that allow some representatives of reptiles, amphibians, and fish to survive long periods of hypoxia and anoxia.

[Effect of hypoxia on the content and stoichiometry of cytochromes in muscle of the gray mullet Liza aurata].

The maintenance of the gray mullet Liza aurata under conditions of hypoxia (P(O2) 55-82 GPa) for 1-2 days led to a decrease of oxygen pressure in arterial blood by 47%, while in venous blood--by 28%. The mean muscle oxygen pressure decreased by 19.2%. The number of hypoxic and anoxic zones in muscle tissue decreased significantly, in particular in red muscle. The maintenance of the fish in hypoxic waters for 15 days led to a rise of the content of cytochromes in muscle and a qualitative readjustment of the mitochondrial respiratory chain manifested in an increase of the content of cytochromes a and a3 and a decrease of cytochrome b. In discussion, literature data are presented which support the described regularity.

[Peculiarities of functioning of liver mitochondria of river lamprey Lampetra fluviatilis and common frog Rana temporaria at periods of suppression and activation of energy metabolism].

The work dealt with study of mitochondria in reversible metabolic suppression of hepatocytes of the river lamprey Lampetra fluviatilis in the course of prespawning starvation and of liver mitochondria of the common frog Rana temporaria during hibernation and activity. In winter the metabolic depression of lamprey hepatocytes, unlike that of frog hepatocytes, has been found to be due to deactivation of complex I of the electron transport mitochondrial chain, a low rate of NAD-dependent substrate oxidation, a low content of adenine nucleotide content, and a high degree of mitochondrial membrane permeability to H+ and other monovalent ions (KCl-, K+). The mitochondrial membrane permeability decreases in the presence of ethyleneglycoldiamineethyltetraacetic acid (EGTA), cyclosporine A (CsA), adenosine-5'-diphosphate (ADP), and Mg+. These facts indicate the presence in these mitochondria of the Ca2+ -dependent unspecific pore in the low-conductance state. Histological studies showed the lamprey and the frog to have principal differences in use of energy substrates at the period of metabolic depression. Lampreys utilize predominantly lipids, whereas frogs--glycogen. The clearly pronounces activation of lipid consumption is observed at the spring period before spawning and death of lamprey. Possible causes of metabolic depression are discussed as well as similarity and difference in behavior of mitochondria of cyclostomes and amphibians throughout metabolic depression and activity.

[Blood amino acid composition of poikilothermic vertebrate under prolonged starvation]. / Aminokislotnyi pul krovi dlitel'no golodaiushchikh poikilotermnykh pozvonochnykh.

Free amino acids in the blood plasma of lamprey (Lampetra fluviatilis) and frog (Rana temporaria) have been determined quantitatively for the periods of deprivation of the exogenous feed. The lamprey's total amino acid pool increased by 74% from November to April and reached the lower limit known for the mammals. The amount of free amino acids in frogs decreased by 40% in the spring as compared with the autumn values. The difference is accounted for by certain features of the living cycles of these animals. A more energetic proteolysis in the lamprey tissues as compared with that in the frog tissues has been confirmed by quantitative determining of leucine, isoleucine and valine in the blood of these animals. Apart from the above, alanine, glycine, lysine, threonine and, in certain periods, tyrosine have been found to be quantitatively significant in the plasma of both animal species. The composition and proportion of the amino acids in blood plasma of these animals are due to specific features of their metabolism and connected with the energy state of the liver cells under starvation.

Reversible metabolic depression in hepatocytes of lamprey (Lampetra fluviatilis) during pre-spawning: regulation by substrate availability.

The regulation of oxidative metabolism in hepatocytes of lampreys (Lampetra fluviatilis) during the freshwater pre-spawning period of their life cycle was studied. The energy metabolism in these cells is characterized by a simplified scheme, where glycolytic ATP production is insignificant and fatty acids are the major respiratory substrates. Seasonal changes in aerobic cell metabolism include a considerable reversible depression of metabolic rate in lamprey hepatocytes during the winter months of the pre-spawning period. The depression is characterized by a more than twofold decrease in hepatocyte endogenous respiration rate, a reduction of oxidative phosphorylation and drop in cellular ATP content. The addition of fatty acids to the hepatocyte incubation medium prevents the decrease in the metabolic rate. In spring, before spawning, a marked activation of energy metabolism in lamprey hepatocytes is found. These observations support the conclusion that the regulation of lamprey hepatocyte energy metabolism is realized through the availability of fatty acids for oxidation.

Tertiary ammonium ion induces contraction of rat aorta segments and increases the mobility of lipids in the membrane of rat aorta smooth muscle cells.

The effects of tertiary ammonium ion--IEM-1194 (decyldiisopropylammonium bromide)--on smooth muscle cells (SMC) isolated from rat aorta were investigated. Using the patch-clamp technique in the cell-attached configuration, two types of effects on the Ca(2+)-activated K+ channels were recorded after application of IEM-1194: an increase in the number of fast transition bursts in open channels and the prolongation of the burst. The removal of the agonist led to the activation of these channels. Mechanical responses of aortic rings were recorded using the method of isometric tension measurements. IEM-1194 (100-400 microM) caused contractions consisting of two phases. The first phase emerged immediately after application of the agonist. The second phase was observed 10-15 min after application. The contraction of the aorta was followed by the relaxation for over 1.5 h. The same results were obtained in the Ca(2+)-free external solution. Measurements of SMC membrane fluidity by the EPR method showed that IEM-1194 induced an increase in the mobility of membrane lipids. Based on these results, we suggest a mechanism of IEM-1194 action on the Ca(2+)-activated K+ channels.

[The mitochondria of poikilothermic vertebrates: oxidative phosphorylation and adenine nucleotides]. / Mitokhondrii nekotorykh poikilotermnykh pozvonochnykh: okislitel'noe fosforilirovanie i adeninovye nukleotidy.

The respiration and phosphorylation velocities in lamprey liver mitochondria are high and with some Krebs cycle substrates they even exceed those of mammals. These parameters in frog liver mitochondria during winter period are 2-3 times lower as compared to rat mitochondria. The adenine nucleotide contents in liver mitochondria of lampreys, fish and frogs are 2-8 times lower than in mitochondria of adult mammals; they are comparable to these parameters in liver mitochondria of rats at the earliest stages of postnatal ontogenesis. Participation of intramitochondrial adenine nucleotides in regulation of oxidative phosphorylation of poikilothermic vertebrates in vivo is discussed.

[The seasonal dynamics of the adenine nucleotide level in the liver mitochondria of the frog Rana temporaria]. / Sezonnaia dinamika soderzhaniia adeninovykh nukleotidov v mitokhondriiakh pecheni liagushki Rana temporaria.

ATP, ADP and AMP content of liver mitochondria has been determined in frogs immediately after isolation during autumn, winter and spring periods. Seasonal changes in adenine nucleotides in frogs are similar to those observed in rat liver mitochondria during early postnatal ontogenesis. It is suggested that in frogs seasonal changes in liver intramitochondrial adenine nucleotides depend on the hormonal condition of animals.