Application of Cortexin for correcting the consequences of hypoxic-ischemic damage in the brain of infant rats

To verify if the peptide preparation Cortexin can be used to correct pathological processes in the CNS during perinatal ontogenesis, a set of physiological parameters (EMG, ECG, respiration, vagosympathetic balance) were recorded and analyzed in a rat perinatal hypoxic-ischemic brain damage (PHIBD) model and control infant rats. In experimental 7-day-old animals, PHIBD was modeled under inhalation ether anesthesia by ligation of the left common carotid artery and subsequent exposure to a gas mixture of 8% oxygen and 92% nitrogen. 1 h after exposure, animals were first injected intraperitoneally with cortexin (1 mg/kg); the preparation was then injected at a daily basis for 10 days. Both control animals and those after surgery but non-treated were injected with physiological solution. After 10 and 30 days after surgery, animals exhibited a delayed body weight gain versus control and significant differences in EMG intensity and spectral structure. Cortexin treatment induced on day 10 a transient improvement in EMG spectral structure but not amplitude; by day 30, the positive effect of cortexin was no longer observed. The respiration rate both in treated and non-treated animals was higher than in control. No significant changes in the heart rate were revealed in animals with PHIBD, but non-treated animals exhibited on day 30 a tendency towards its decrease. The heart rate variability (HRV) analysis showed that 10 days after trauma both non-treated and cortexin-treated animals exhibited a statistically significant shift in the vagosympathetic balance towards a parasympathetic prevalence. On day 30, cortexin treatment yields positive effects, while in non-treated animals the vagosympathetic balance shifts towards a humoral-metabolic and sympathetic prevalence. Cortexin injection to intact rats leads to significant disturbances in the vagosympathetic balance, cardiac and, to a lesser extent, respiratory rhythms, and can cause stable disturbances in activity of the somatic and vegetative nervous systems.     

Osteogenesis imperfecta murine: interaction between type I collagen homotrimers

Types I, II, and III collagens are believed to have evolved from the same homotrimer ancestor and they have substantial sequence homology, but type I molecules are alpha1(I)(2)alpha2(I) heterotrimers, unlike homotrimeric types II and III. It is believed that the alpha2(I) chain first appeared in lower vertebrates and that it plays a particularly important role in bone formation. For instance, spontaneous mutations resulting in non- functional alpha2 chains and formation of type I homotrimers cause severe bone pathology (osteogenesis imperfecta) in humans and in animals. However, the exact role of the alpha2 chain is not known. Here, we report measurements of intermolecular forces between collagen helices in native and reconstituted fibers composed of type I homotrimers, heterotrimers and their mix. For comparison, we report forces between type II homotrimers in reconstituted fibers. In agreement with previous studies, we find that the absence of the alpha2 chain reduces temperature-favored attraction between collagen helices, either because of the difference in amino acid sequence of the alpha1 and alpha2 chains or because of more extensive post-translational modification of homotrimers. We find that forces between helices in fibers from type I (as well as type II) homotrimers are not sensitive to pH between pH 6 and 7.5, in contrast to type I heterotrimers. Apparently, the effect of pH is related to extra histidine residues present on alpha2 chains but not on alpha1 chains. Finally, our measurements indicate that the alpha2 chain is responsible for binding some soluble compound(s), possibly glycosaminoglycans, whose displacement results, e.g., in the loss of tendon crystallinity. The ability of the alpha2 chain to bind non-collagen matrix components may be particularly important for bone matrix formation and mineralization.     

Age and growth of the Pacific halibut <Emphasis Type="Italic">Hippoglossus stenolepis</Emphasis> and the size-age composition of its catches in the North-Western part of the Pacific Ocean

The results of investigation are discussed on age and growth of the Pacific halibut Hippolglossus stenolepis, as well as size-age composition of its catches in three regions of the North-Western Pacific—in Navarin area of the Bering Sea, in Pacific waters on the Northern Kurils and south-eastern Kamchatka, of the Southern Kurils—from the end of the last century. The growth rate of Pacific halibut is similar in all three regions in spite of their considerable geographic remoteness. No significant differences in the growth rate of males and females in these regions, as well as no significant interannual differences in growth of specimens caught in Pacific waters off the Northern Kurils and south-eastern Kamchatka in 1996–2000, are found. Comparison of the present-day size-age composition and that in the beginning-middle of the last century revealed their considerable similarity.     

Effect of cetyltrimethylammonium on the human blood cholinesterases activity

The influence of cationic detergent cetyltrimethylammonium on the human blood cholinesterases activity (erythrocyte acetylcholinesterase and plasma butyrylcholinesterase) in reactions of hydrolysis of alpha-thionaphthylacetat and acetylthiocholine is studied. It is shown, that cetyltrimethylammonium is reversible effector for both cholinesterases. This compound competitively inhibited enzymatic hydrolysis of acetylthiocholine by both cholinesterases, and in the reactions of enzymatic hydrolysis alpha-thionaphthylacetat display as the synergistic activator--in experiments with butyrylcholinesterase, and as the reversible inhibitor--in experiments with acetylcholinesterase. Kinetic constants in reaction of acetylcholinesterase inhibition by cetyltrimethylammonium defined by means of different substrates--alpha-thionaphthylacetat and acetylthiocholin. They are close among themselves and amount (2.5 +/- 0.3) x 10(-5) and (2.8 +/- 0.3) x 10(-5) M, accordingly. Butyrylcholinesterase was more sensitive to influence of cetyltrimethylammonium. The kinetic constants defined for this enzyme by the effect of inhibition of acetylthiocholin hydrolysis or activation of alpha-thionaphthylatcetat hydrolysis, are also close among themselves and amount (3.9 +/- 0.4) x 10(-6) and (4.4 +/- 0.4) x 10(-6) M, accordingly.     

Thermal stability of lactate dehydrogenase in the complex with the anion polyelectrolyte poly(styrene sulfonate)

The temperature stability of the cytoplasmic enzyme of the glycolysis of lactate dehydrogenase from a pig muscle (isoenzyme M4) in a complex with the anion polyelectrolyte poly(styrenesulfonate) has been investigated by the methods of adiabatic differential scanning microcalorimetry, the own protein fluorescence, and circular dichroism. Calorimetric investigations of complex of lactate dehydrogenase with poly(styrenesulphonate) in 50 mM phosphate buffer at pH 7.0 have shown that the temperature of the transition and enthalpy of lactate dehydrogenase thermal denaturation sharply decreases with growing weight ratio poly(styrenesulphonate)/lactate dehydrogenase, though at 20 degrees C the enzyme activity of lactate dehydrogenase remains unchanged for several hours irrespective of the addition of poly(styrenesulphonate). The addition of phosphate ions to the solution enhances the resistance of lactate dehydrogenase to both thermal denaturation and inactivation by polyelectrolyte. The data obtained are interpreted from the viewpoint of a special role of two anion-binding centers in intersubunits contacts of lactate dehydrogenase, which enhance its resistance to both thermal denaturation and destruction by polyelectrolyte.     

Immunostimulating and anticoagulating activity of fucoidan from brown algae Fucus evanescens of Okhotskoe sea]

Fucoidan--nontoxic sulfated polysaccharide was isolated from brown algae Fucus evanescens in Okhotskoe Sea. Chemical analysis of the compound was performed, it was shown that fucoidan is freely soluble in water and acid solutions. Immunotropic and anticoagulating properties of the compound were evaluated in comparison with heparin. It was demonstrated that fucoidan in wide range of doses stimulated phagocytic and bactericidic activity at leucocytes of mice peritoneal exudate. Heparin on the contrary demonstrated depressive effect on these functions at high dose. It was shown that fucoidan has dose-dependent anticoagulating activity in vitro and in vivo comparable with heparin activity. The results of investigation demonstrated possibility of fucoidan application as immunomodulating and anticoagulating agent of plant origin.     

Erythrobacter vulgaris sp. nov., a novel organism isolated from the marine invertebrates

Four yellow-pigmented, gram-negative, chemoorganotrophic aerobic bacteria were isolated from starfish Stellaster equestris (strains 022-2-10T, 022-2-9, and 022-2-12) and soft coral (unidentified species) (strain 022-4-7) collected in the South China Sea. 16S rRNA gene sequence-based analyses of the new organisms revealed that Erythrobacter spp. were the closest relatives and shared the highest similarity of 98.7% to E. citreus, 98.5% to E. flavus, 97.9% to E. litoralis and 97.6% to E. longus. The novel organisms were tolerant to 3-6% NaCl, grew between 10 degrees C and 40 degrees C, and were not able to degrade gelatin, casein, and agar, while degraded Tween 80. Two strains (022-2-9 and 022-2-12) could weakly degrade starch. All strains produced a large pool of carotenoids and did not have Bacteriochlorophyll a. Phosphatidylethanolamine (30-36%), phosphatidylglycerol (39-46%), and phosphatidylcholine (21-27%) were the predominant phospholipids. Sphingoglycolipid was not detected. The major fatty acids were 16:0 (6-11%), 16:1omega7 (12-15%), and 18:1omega7 (46-49%). The two-hydroxy fatty acids, 13:0-2OH, 14:0-2OH, 15:0-2OH, 16:0-2OH were also present. The G + C content of the DNAs ranged from 61 to 62 mol%. The level of DNA similarity among four strains was conspecific and ranged from 94% to 98%. Even though new strains and other species of the genus had rather high level of 16S rRNA gene sequence similarities, DNA-DNA hybridization experiments showed only 33-39% of binding with the DNA of the type strains. On the basis of these results and the significant differences demonstrated in the phenotypic and chemotaxonomic characteristics, it is suggested that the new organisms be classified as a novel species; the name Erythrobacter vulgaris sp. nov. is proposed. The type strain is 022-2-10T (= KMM 3465T = CIP 107841T).     

Interpersonal Interaction under the Conditions of High Autonomy in Interplanetary Mission Simulation (Mars-500 Experiment)

This paper discusses the influence of the social status and psychological stability of individuals on their communicative behavior in space flight on the basis of retrospective analysis of the findings of the Mars-500 experiment, in which six participants were isolated for a period of simulating a long-term exploration mission. Data were obtained using both classic social-psychological methods and observation of video recorded behavior. Communicative behavior of the crew members was dependent on the level of individual anxiety and social status in the isolated small group.     

Interaction of protein with charged colloidal particles

The functional state of three proteins of different molecular weight (urease, lactate dehydrogenase, and hemoglobin) in the presence of the linear polyelectrolytes poly(allylamine hydrochloride) (PAA) and sodium poly(styrenesulfonate) (PSS) in the dissolved state and of the same polyelectrolytes bound to the surface of microspheres has been investigated. Microspheres were prepared by consecutive absorption of oppositely charged polyelectrolytes so that the outer layer of the shell was PAA for the acidic protein urease, and PSS for the alkaline proteins LDH and hemoglobin. It was shown that the dissolved polyelectrolyte completely inactivates all three proteins within one minute with a slight difference in the time constant. (By Hb inactivation are conventionally meant changes in the heme environment observed from the spectrum in the Soret band.) In the presence of microspheres, the proteins were adsorbed on their surface; in this case, more than 95% of the activity was retained within two hours. The proportion of the protein adsorbed on microspheres accounted for about 98% for urease, 72% for Hb, and 35% for LDH, as determined from the tryptophan fluorescence data. The interaction of hemoglobin with another type of charged colloidal particles, phospholipid vesicles, leads to the destruction of the tertiary structure of the protein, which made itself evident in the optical absorption spectra in the Soret band, as well as the spectra of tryptophan fluorescence and circular dichroism. In this case, according to circular dichroism, the percentage of α-helical structure of Hb was maintained. The differences in the physical and chemical mechanisms of interaction of proteins with these two types of charged colloidal particles that leads to differences in the degree of denaturing effects are discussed.     

Caprylic Triglyceride as a Novel Therapeutic Approach to Effectively Improve the Performance and Attenuate the Symptoms Due to the Motor Neuron Loss in ALS Disease

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder of motor neurons causing progressive muscle weakness, paralysis, and finally death. ALS patients suffer from asthenia and their progressive weakness negatively impacts quality of life, limiting their daily activities. They have impaired energy balance linked to lower activity of mitochondrial electron transport chain enzymes in ALS spinal cord, suggesting that improving mitochondrial function may present a therapeutic approach for ALS. When fed a ketogenic diet, the G93A ALS mouse shows a significant increase in serum ketones as well as a significantly slower progression of weakness and lower mortality rate. In this study, we treated SOD1-G93A mice with caprylic triglyceride, a medium chain triglyceride that is metabolized into ketone bodies and can serve as an alternate energy substrate for neuronal metabolism. Treatment with caprylic triglyceride attenuated progression of weakness and protected spinal cord motor neuron loss in SOD1-G93A transgenic animals, significantly improving their performance even though there was no significant benefit regarding the survival of the ALS transgenic animals. We found that caprylic triglyceride significantly promoted the mitochondrial oxygen consumption rate in vivo. Our results demonstrated that caprylic triglyceride alleviates ALS-type motor impairment through restoration of energy metabolism in SOD1-G93A ALS mice, especially during the overt stage of the disease. These data indicate the feasibility of using caprylic acid as an easily administered treatment with a high impact on the quality of life of ALS patients.