Energy and plastic metabolism of the heart muscle in rabbits undergoing thyroid irradiation with decimeter waves

The functional state of myocardial mitochondria, the glycogen and nucleic acid contents in myocardium, and morphometry of structural elements of cardiomyocytes and myocardial capillary network were investigated in order to select the optimal regimen of decimeter wave exposures with power density of 10, 120 and 240 mW/cm2 on the area of thyroid gland. It was shown that the thyroid gland exposure to decimeter waves at these intensities resulted in functional shifts in energy and plastic processes in myocardium and capillary blood supply. These changes increased to a considerable extent as the intensity of exposure was increasing and reached the maximum at power density of 240 mW/cm2 but event at this intensity there was not found the injurious effect of decimeter waves on the myocardium.     

Effect of microwaves on the expression by thymocytes of various surface membrane markers

A study was made of the effects of microwave irradiation of different intensity within decimeter and centimeter ranges in vitro on the guinea-pig thymocyte-induced receptor expression to their own and rabbit erythrocytes. Besides, effects of decimeter waves on mice thymocyte-induced expression of Thy-1 antigen were studied. Microwaves were found to modulate the thymocyte-induced expression of the membrane surface markers under study.     

The immunomodulating action of microwaves in the induction of an immune response to Vi antigen

In this work the possibility of using microwaves for immunomodulation in the immunization of animals with thymus-independent antigen was studied. The projection zones of the thymus and adrenal glands of the test animals were subjected to the action of decimeter, or ultrahigh frequency (UHF), waves, while the corresponding zones of the control animals were subjected to imitation UHF irradiation. Vi-antigen was shown to be a thymus-independent antigen for rabbits (according to the results of the evaluation of the functional state of thymocytes, as manifested by the adsorption of acridine orange by the chromatin of thymocyte nuclei and by the content of RNA and DNA in the thymus). The action of UHF waves on the projection zone of the thymus was accompanied by a decrease in the glucocorticoid activity of the adrenal cortex, observed simultaneously with a pronounced immunostimulating effect. The UHF irradiation of the zone of the adrenal glands was accompanied by immunosuppression in combination with enhanced glucocorticoid activity of the adrenal cortex.     

p-155, a multimeric platelet protein that is expressed on activated platelets

Platelets respond to a large number of stimuli by undergoing complex biochemical and morphological changes. These changes are involved in physiological processes including adhesion, aggregation, and coagulation. Platelet activation produces membrane alterations that can be recognized by monoclonal antibodies. In this report we describe a novel activation-dependent protein recognized by a monoclonal antibody, JS-1. The platelet glycoprotein was designated p-155 according to its apparent reduced molecular weight, p-155 exists in the native state as varying sized, large multimers held together by disulfide bonds. p-155 is released upon platelet activation and binds to the activated platelet surface. Although p-155 and platelet glycoprotein Ia migrate similarly on reduced sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunodepletion and isoelectric focusing distinguished p-155 from glycoprotein Ia. p-155 differed from von Willebrand factor and from thrombospondin in its reduced molecular weight. Additionally, immunoblotting of immunoprecipitated p-155 with antisera to von Willebrand factor and to thrombospondin confirmed the unique identity of p-155. Evidence for a soluble, nonintegral membrane-associated protein was obtained by Triton X-114 phase separation studies, membrane elution studies, and by the demonstration of the protein in the aqueous phase of platelet releasate. Both radioimmunoprecipitation and direct binding techniques demonstrated the activation-dependent nature of p-155. The protein could not be detected in other blood cells, endothelial cells, HEL cells, liver, or in plasma. The functional role of p-155 in platelets is not yet known.     

Comparison of the duration and power spectral changes of monopolar and bipolar M waves caused by alterations in muscle fibre conduction velocity

The muscle compound action potential (M wave) recorded under monopolar configuration reflects both the propagation of the action potentials along the muscle fibres and their extinction at the tendon. M waves recorded under a bipolar configuration contain less cross talk and noise than monopolar M waves, but they do not contain the entire informative content of the propagating potential. The objective of this study was to compare the effect of changes in muscle fibre conduction velocity (MFCV) on monopolar and bipolar M waves and how this effect depends on the distance between the recording electrodes and tendon. The study was based on a simulation approach and on an experimental investigation of the characteristics of surface M waves evoked in the vastus lateralis during 4-s step-wise isometric contractions in knee extension at 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90% MVC. The peak-to-peak duration (Durpp) and median frequency (Fmedian) of the M waves were calculated. For monopolar M waves, changes in Durpp and Fmedian produced by MFCV depended on the distance from the electrode to the tendon, whereas, for bipolar M waves, changes in Durpp and Fmedian were largely independent of the electrode-to-tendon distance. When the distance between the detection point and tendon lay between approximately 15 and 40 mm, changes in Durpp of bipolar M waves were more pronounced than those of distal monopolar M waves but less marked than those of proximal monopolar M waves, and the opposite occurred for Fmedian. Since, for bipolar M waves, changes in duration and power spectral features produced by alterations in MFCV are not influenced by the electrode-to-tendon distance, the bipolar electrode configuration is a preferable choice over monopolar arrangements to estimate changes in conduction velocity.     

Dynamics of diurnal changes in serum concentration of TNF-alpha soluble receptors in gastrointestinal cancer patients

The objective of the study was to investigate the dynamic changes in soluble TNFalpha p-55 and p-75 receptors in serum of advanced cancer patients during 24 hours. The group examined consisted of 42 patients suffering from advanced gastrointestinal neoplasms (colorectal, gastric and pancreatic cancer). Serum levels of the cytokine and both receptors in cancer patients were measured using ELISA type kits 6 times a day (8.00 a.m., 2.00 p.m., 6.00 p.m., 10.00 p.m., 2.00 a.m. and again 8.00 a.m.) as well as in healthy controls. The levels of TNFalpha and its soluble receptors were substantially increased in the examined group and displayed statistically significant circadian fluctuations. The presence of circadian rhythm of the cytokine was proved (acrophase - 00.36 a.m.), however no diurnal rhythm of soluble TNF receptors was observed. The concentration of p-55 receptor was distinctly lower then p-75. The peak p-55 value appeared at 10.00 p.m. while the p-75 reached its minimum level at the same time. Although there was no statistical correlation between the receptor concentrations the shapes of both curves remained inversely proportional. The present results may suggest the presence of complex self-regulation mechanisms in advanced gastrointestinal cancer patients.     

Microwaves in the Induction of Immune Response to VI-Antigen

In this work the possibility of using microwaves (MW) for immuno-modulation in the immunization of animals with thymus-independent antigen was studied. The projection zones of the thyroid and adrenal glands of the test animals were subjected to the action of decimeter MW, while the corresponding zones of control animals were subjected to imitation MW. The endocrine activity of rabbits was estimated by radioim-mune methods. Vi-antigen was shown to be a thymus-independent antigen for rabbits, according to the results of fluorescent probes to study the structural rearrangements in surfaces of thymocyte membranes and their nuclei, which reflect early changes during the physiological activation of cells. The irradiation by MW on the projection zone of the thyroid was accompanied by a decrease in the glucocorticoid activity of the adrenal cortex and a simultaneous pronounced immunostimulating effect. MW irradiation of the zone of the adrenal glands was accompanied by immunosuppression in combination with enhanced glucocorticoid activity of the adrenal cortex.     

Interactions between p-33 and p-55 domains of the Helicobacter pylori vacuolating cytotoxin (VacA)

The VacA toxin secreted by Helicobacter pylori is considered to be an important virulence factor in the pathogenesis of peptic ulcer disease and gastric cancer. VacA monomers self-assemble into water-soluble oligomeric structures and can form anion-selective membrane channels. The goal of this study was to characterize VacA-VacA interactions that may mediate assembly of VacA monomers into higher order structures. We investigated potential interactions between two domains of VacA (termed p-33 and p-55) by using a yeast two-hybrid system. p-33/p-55 interactions were detected in this system, whereas p-33/p-33 and p-55/p-55 interactions were not detected. Several p-33 proteins containing internal deletion mutations were unable to interact with wild-type p-55 in the yeast two-hybrid system. Introduction of these same deletion mutations into the H. pylori vacA gene resulted in secretion of mutant VacA proteins that failed to assemble into large oligomeric structures and that lacked vacuolating toxic activity for HeLa cells. Additional mapping studies in the yeast two-hybrid system indicated that only the N-terminal portion of the p-55 domain is required for p-33/p-55 interactions. To characterize further p-33/p-55 interactions, we engineered an H. pylori strain that produced a VacA toxin containing an enterokinase cleavage site located between the p-33 and p-55 domains. Enterokinase treatment resulted in complete proteolysis of VacA into p-33 and p-55 domains, which remained physically associated within oligomeric structures and retained vacuolating cytotoxin activity. These results provide evidence that interactions between p-33 and p-55 domains play an important role in VacA assembly into oligomeric structures.     

Metabolic and EEG alterations during the early phase of triethyltinsulphate (TET) intoxication

EEG changes as well as the mechanisms of the hyperglycaemic effect of triethyltinsulphate (TET), a compound known to induce brain oedema, were investigated in cats and rabbits, respectively. Considerable EEG alterations characterized by slow waves appeared in some minutes after TET administration. The hyperglycaemic effect of TET like that of epinephrine could be prevented by the administration of 1 mg/kg of the beta blocker, pindolol. It is suggested that the hyperglycaemic effect of TET is brought about by sympathetic activation.     

Decreased impacts of the 2003 heat waves on mortality in the Czech Republic: an improved response?

The paper examines impacts on mortality of heat waves in 2003, the hottest summer on record in the Czech Republic, and compares them with previous similar events. While most summer heat waves over the period since 1986 were associated with significantly elevated mortality, this was not the case for three out of the four heat waves in 2003. The relatively weak mortality response was particularly noteworthy for the most severe heat wave which occurred in the first 10 days of August 2003 and resulted in enormous excess mortality in some western European countries. A mortality displacement effect and short-term adaptation to heat contributed to the reduced mortality impacts of the heat waves that followed after previous relatively warm periods. However, the decreased mortality response of the 2003 heat waves compared to previous heat waves in the 1990s is also likely to have arisen from positive health-care and other socio-economic changes in the post-communist central European region over the past decade, as well as a better public awareness of heat-related risks due to enhanced media coverage and regular biometeorological forecast and warnings.     

Changes in the cellular glycosaminoglycans of cultured mastocytoma cells induced by sodium butyrate

The effect of sodium butyrate on the cellular glycosaminoglycans of cultured mastocytoma p-815-4 cells was investigated using enzymic digestion, electrophoresis, nitrous acid degradation, and sequential partition fractionation. The average cellular glycosaminoglycan content of mastocytoma p-815-4 cells grown in the presence of 2 mM sodium butyrate was ten times as much as that of the control p-815-4 cells. Approximately 90% of the glycosaminoglycans isolated from the control cells and 70% from the butyrate-treated cells were found to be chondroitin 4-sulfate by enzymic digestion. The remainders were chondroitinase ABC-resistant. Hyaluronic acid and dermatan sulfate were not detected in either control cells or butyrate-treated cells. The chondroitinase ABC-resistant fraction of glycosaminoglycans from butyrate-treated cells showed a molar ratio of sulfate to uronic acid of more than 2.0, and provided some physicochemical properties characteristics to reference bovine lung heparin.     

Diurnal changes in maize leaf photosynthesis : I. Carbon exchange rate, assimilate export rate, and enzyme activities

Diurnal changes in photosynthetic parameters and enzyme activities were characterized in greenhouse grown maize plants (Zea mays L. cv Pioneer 3184). Rates of net photosynthesis and assimilate export were highest at midday, coincident with maximum irradiance. During the day, assimilate export accounted for about 80% of net carbon fixation, and the maximum export rate (35 milligrams CH₂O per square decimeter per hour) was substantially higher than the relatively constant rate maintained through the night (5 milligrams CH₂O per square decimeter per hour). Activities of sucrose phosphate synthase and NADP-malate dehydrogenase showed pronounced diurnal fluctuations; maximum enzyme activities were generally coincident with highest light intensity. Reciprocal light/dark transfers of plants throughout the diurnal cycle revealed that both enzymes were deactivated by 30 minutes of darkness during the day, and they could both be substantially activated by 30 minutes of illumination at night. During 24 hours of extended darkness, sucrose phosphate synthase activity declined progressively to an almost undetectable level, but was activated after 1.5 hours of illumination. Thus, the diurnal fluctuation in maize sucrose phosphate synthase can be explained by some form of light modulation of enzyme activity and is not due to an endogenous rhythm in activity. No diurnal fluctuations were observed in the activities of NADP-malic enzyme or fructose 6-phosphate-2-kinase. Phosphoenolpyruvate carboxylase was activated by light to some extent (about 50%) when activity was measured under suboptimal conditions in vitro. The results suggested that the rates of sucrose formation and assimilate export were closely aligned with the rate of carbon fixation and the activation state of sucrose phosphate synthase.     

Photosynthetic Adaptation of Solanum dulcamara L. to Sun and Shade Environments: II. Physiological Characterization of Phenotypic Response to Environment

Photosynthetic and growth properties of Solanum dulcamara L. were studied under controlled environments. The 200 experimentally tested plants were clonal replicates of five field-collected individuals, three from fully exposed habitats and two from deeply shaded habitats. After 4 weeks of growth in one of eight environmental treatments, each plant was measured for leaf adaxial and abaxial conductance to water vapor, specific leaf weight, chlorophyll per square decimeter of leaf, photosynthetic unit size, light-saturated photosynthetic rate, total leaf area, and total leaf, stem, and root dry weights. Changes in light level influenced photosynthesis and growth of each plant more than changes in water availability or temperature. It is strongly suggested that the primary adaptive response of the tested individuals to changes in levels of light involves the regulation of leaf thickness.     

Increased insulin sensitivity in Gsalpha knockout mice

The stimulatory guanine nucleotide-binding protein (G(s)) is required for hormone-stimulated cAMP generation. Gnas, the gene encoding the G(s) alpha-subunit, is imprinted, and targeted disruption of this gene in mice leads to distinct phenotypes in heterozygotes depending on whether the maternal (m-/+) or paternal (+/p-) allele is mutated. Notably, m-/+ mice become obese, whereas +/p- mice are thinner than normal. In this study we show that despite these opposite changes in energy metabolism, both m-/+ and +/p- mice have greater sensitivity to insulin, with low to normal fasting glucose levels, low fasting insulin levels, improved glucose tolerance, and exaggerated hypoglycemic response to administered insulin. The combination of increased insulin sensitivity with obesity in m-/+ mice is unusual, because obesity is typically associated with insulin resistance. In skeletal muscles isolated from both m-/+ and +/p- mice, the basal rate of 2-deoxyglucose uptake was normal, whereas the rate of 2-deoxyglucose uptake in response to maximal insulin stimulation was significantly increased. The similar changes in muscle sensitivity to insulin in m-/+ and +/p- mice may reflect the fact that muscle G(s)alpha expression is reduced by approximately 50% in both groups of mice. GLUT4 expression is unaffected in muscles from +/p- mice. Increased responsiveness to insulin is therefore the result of altered insulin signaling and/or GLUT4 translocation. This is the first direct demonstration in a genetically altered in vivo model that G(s)-coupled pathways negatively regulate insulin signaling.     

The alternative stimulatory G protein alpha-subunit XLalphas is a critical regulator of energy and glucose metabolism and sympathetic nerve activity in adult mice

The complex imprinted Gnas locus encodes several gene products including G(s)alpha, the ubiquitously expressed G protein alpha-subunit required for receptor-stimulated cAMP generation, and the neuroendocrine-specific G(s)alpha isoform XLalphas. XLalphas is only expressed from the paternal allele, whereas G(s)alpha is biallelically expressed in most tissues. XLalphas knock-out mice (Gnasxl(m+/p-)) have poor suckling and perinatal lethality, implicating XLalphas as critical for postnatal feeding. We have now examined the metabolic phenotype of adult Gnasxl(m+/p-) mice. Gnasxl(m+/p-) mice had reduced fat mass and lipid accumulation in adipose tissue, with increased food intake and metabolic rates. Gene expression profiling was consistent with increased lipid metabolism in adipose tissue. These changes likely result from increased sympathetic nervous system activity rather than adipose cell-autonomous effects, as we found that XLalphas is not normally expressed in adult adipose tissue, and Gnasxl(m+/p-) mice had increased urinary norepinephrine levels but not increased metabolic responsiveness to a beta3-adrenergic agonist. Gnasxl(m+/p-) mice were hypolipidemic and had increased glucose tolerance and insulin sensitivity. The similar metabolic profile observed in some prior paternal Gnas knock-out models results from XLalphas deficiency (or deficiency of the related alternative truncated protein XLN1). XLalphas (or XLN1) is a negative regulator of sympathetic nervous system activity in mice.     

Overexpression of RAPGEF3 enhances the therapeutic effect of dezocine in treatment of neuropathic pain

Pain is a significant problem worldwide that affects the quality of life of patients. Dezocine is a non-addictive analgesic drug with kappa-opioid antagonist activity and has been successfully used to alleviate of postoperative pain. In addition, dezocine has an analgesic effect similar to that of morphine, alleviating moderate to severe pain. Rap guanine nucleotide exchange factor 3 (RAPGEF3) is a guanine nucleotide exchange factor for GTPases Rap1 and Rap2, which could enhance the activity of Rap1 to promote cell adhesion and axon regeneration, as well as promote neurite extension by interacting with nerve growth factors. Here, we first observed that overexpression of RAPGEF3 increased cell viability, as shown by a CCK-8 assay, and recovered brain function in rats. The expression of inflammation-related factors at the mRNA level was detected using qPCR, and the concentration of these factors in a cultured cell medium and rat serum samples were decreased as shown by ELISA after RAPGEF3 overexpression. Through western blotting, we further found that pro-inflammatory proteins were decreased, and these effects might be mediated by inhibition of the Ras/p-38 MAPK signaling pathway. Taken together, we speculated that RAPGEF3overexpression enhances the therapeutic effect of dezocine on neuropathic pain by inhibiting the inflammatory response through inhibition of the Ras/p-38 MAPK signaling pathway.Keywords: RAPGEF3, dezocine, neuropathic pain, Ras/p-38 MAPK, inflammation     

The change of negative components of the evoked potentials of spinal cord after irradiating of a SHF-waves

The influence of super high frequency (SHF) waves (lambda = 3 sm) nonthermal intensity (1.6 mWt/sm2) on work of regulator systems of a spinal cord (SC) of cats was considered. The estimation of parameters of negative components of cord dorsum potential (CDP) is made for stimulus, which apply on peripheral nerves or dorsal root earlier and after the influence of SHF on SC. Change in work of population of segmentary and non-segmentary interneurons after the SHF irradiation with 30 minutes exposition was shown. The authors consider that the main influence SHF waves is directed on a changes of membrane potential of SC neurons. The specified effect carries temporary and convertible character.     

Changes in the Light Scattering by Symbiosomes from Vicia faba Root Nodules as Indicator of Ion and Metabolite Transport across the Peribacteroid Membrane

Passive transport of ions and metabolites across the peribacteroid membrane (PBM) was investigated on symbiosome preparations isolated from the broad bean (Vicia faba L.) root nodules and suspended in a potassium-free medium. Optical density of the symbiosome suspension at 546 nm was monitored as an indicator of light-scattering changes. Depolarization of the PBM with tetraphenylphosphonium cation (TPP⁺) caused an increase in light scattering of symbiosome suspension. This effect was enhanced after adding a K⁺ ionophore valinomycin to the incubation medium. A similar effect was observed after supplementing the symbiosome suspension with nigericin, a K⁺/H⁺ antiporter. Similar experiments on bacteroid suspensions prepared from isolated symbiosomes did not reveal any appreciable changes in light scattering in the presence of the same membrane-active substances. The light scattering by symbiosome suspensions decreased after adding malate or succinate, while the subsequent addition of centimolar concentrations of K⁺ substantially accelerated this process. Light scattering by the symbiosome suspension was insensitive to the addition of glutamate, a substance normally impermeant through the PBM of legume root nodules. These results suggest that the changes in light scattering by symbiosomes reflect the osmotically induced changes of symbiosome volume. These volume changes were assigned to alteration of the peribacteroid space (PBS). The incubation of symbiosomes in a potassium-free medium acidified their the PBS; this acidification was accelerated by valinomycin, carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (FCCP), and nigericin, and it was abolished in the presence of comparatively high concentrations of K⁺ in the incubation medium. The results indicate a relatively high permeability of the PBM to K⁺ ions.     

The effect of etimizol on the excitability and spontaneous super-slow activity of the structures of the rabbit brain]

Spontaneous superslow electrical brain activity and its changes were studied in acute experiments on curarized rabbits after administration of etimysol in doses of 1.0, 1.5 and 2.5 mg/kg. The effect of the drug persisted for three hours. Two oscillation phases were recorded in the medial group of mesencephalic reticular nuclei and the lateral nucleus of the hypothalamus: a short positive phase and a prolonged negative one. In other brain structures only negative waves were recorded. A significant functional rearrangement of correlative connections of brain structures took place in 90 minutes after the drug administration. The factor analysis showed that the most subtle connections were preserved in the neocortex and the dorsal hippocampus.