Role of substance P in regulating the feeding behavior and the avoidance reaction in the rabbit

Similar changes in feeding and avoidance reaction in spite of the way of substance P administration (30 mgk/kg intravenously or 14,8 nmol intraventricular) were found in rabbits with electrodes implanted in various limbic-midbrain structures. Feeding was found to be more sensitive to substance P administration, as it was shown by the decrease of excitability of the hypothalamic "feeding center" and abolishing of the inhibitory and facilitatory effects on this center from the dorsal hippocampus and the midbrain reticular formation, correspondingly. New cortical-subcortical integration under substance P was presented in new characteristics of EEG activity in neocortical areas, both background and in response to stimulation of various limbic-midbrain structures. Biochemical data let to suggest that at the neural level substance P led to destabilization of membrane structures in endoplasmatic reticulum and to redistribution of membrane-connected N-acetylneuramine acid which was directly involved in neurotransmission.     

A two-step purification procedure for sheep liver 6-phosphogluconate dehydrogenase

A two-step procedure for the purification of 6-phosphogluconate dehydrogenase (EC 1.1.1.44; 6-PGDH) from sheep liver is described. The enzyme is directly bound to cellulose phosphate by batch extraction and eluted with a linear salt gradient. Purification is completed by affinity chromatography using NADP(+)-agarose. The result is 6-PGDH of high purity, greatly increased yield, and the highest specific activity yet achieved, with a significant reduction in the purification time.     

Analysis of Some Physiological and Biochemical Indices in Patients with Covid-19 Pneumonia Using Mathematical Methods

Journal of Evolutionary Biochemistry and Physiology - The aim of the work was to conduct a retrospective analysis of the clinical data of patients with pneumonia caused by the SARS-CoV-2 virus, and...     

Hydraulic failure and tree dieback are associated with high wood density in a temperate forest under extreme drought

Catastrophic hydraulic failure will likely be an important mechanism contributing to large‐scale tree dieback caused by increased frequency and intensity of droughts under global climate change. To compare the susceptibility of 22 temperate deciduous tree and shrub species to hydraulic failure during a record drought in the southeastern USA, we quantified leaf desiccation, native embolism, wood density, stomatal conductance and predawn and midday leaf water potential at four sites with varying drought intensities. At the two driest sites, there was widespread leaf wilting and desiccation, and most species exhibited predawn leaf water potentials of ≤3 MPa and >60% loss of xylem conductivity in branches. Although species with high wood density were more resistant to cavitation, they had higher levels of native embolism and greater canopy dieback than species with low wood density. This unexpected result can be explained by the failure of species with dense wood to avert a decline in water potential to dangerous levels during the drought. Leaf water potential was negatively correlated with wood density, and the relationship was strongest under conditions of severe water deficit. Species with low wood density avoided catastrophic embolism by relying on an avoidance strategy that involves partial drought deciduousness, higher sensitivity of stomata to leaf water potential and perhaps greater rooting depth. These species therefore maintained water potential at levels that ensured a greater margin of safety against embolism. These differences among species may mediate rapid shifts in species composition of temperate forests if droughts intensify due to climate change.     

Observations on torquaratorid acorn worms (Hemichordata,Enteropneusta) from the North Atlantic with descriptions of a new genus and three new species

Enteropneusts in the family Torquaratoridae were imaged using still and video cameras in the deep North Atlantic and then collected by remotely operated vehicles. From this material, we describe Yoda purpurata n. gen, n. sp., Tergivelum cinnabarinum n. sp., and Allapasus isidis n. sp. Individuals of the first two species were browsing completely exposed on the sea floor, whereas the specimen of the last species was encountered floating ~1 m above the sea floor. Living specimens of Y. purpurata were 12–19 cm long and had a dark reddish‐purple proboscis, collar, and genital wings (folded dorsally over the anterior region of the trunk). Members of this species were hermaphrodites (the first ever discovered in the phylum Hemichordata), with numerous separate testes and ovaries in the genital wings. Living specimens of T. cinnabarinum were 12–26 cm long and had a cinnabar‐colored proboscis, collar, and back veils (arising from the anterior region of the trunk); sexes were separate, and body shape and internal morphology closely resemble those of its brown congener, T. baldwinae, from the eastern Pacific. The only specimen of A. isidis collected was a male 13 cm long and pale yellow when alive. Its body shape was proportionally shorter and broader than that of its orange congener, A. aurantiacus, from the eastern Pacific, but the internal anatomy of the two species is virtually identical. [Correction made after online publication August 21, 2012 to correct species name in preceding sentence.]     

微重力对石刁柏根尖组织和细胞中钙水平及分布的影响

用焦锑酸钾沉淀法进行了组织和细胞中游离钙的化学定位。用光学显微镜和透射电镜观察石刁柏幼苗在太空飞行后Ｃａ２＋沉淀颗粒在根尖组织和细胞内的分布。结果表明,太空飞行１５天后,Ｃａ２＋在各组织内的分布情况与地面对照无明显差异,但Ｃａ２＋的含量明显低于对照。Ｃａ２＋在细胞内不同区域的分布在飞行和对照样品中差异十分明显,对照细胞中Ｃａ２＋集中在液泡内,其它细胞器中很少见到。飞行幼苗的根尖细胞,液泡中Ｃａ２＋很少,并向液泡膜集结,液泡膜内侧和细胞质中的Ｃａ２＋明显增多。细胞壁中的Ｃａ２＋较对照有明显增加,高尔基体中也有少量钙存在。本文着重讨论了飞行幼苗根尖中Ｃａ２＋在细胞内重新分布的可能作用。     

Species, population and age diversity in cell resistance to adhesion of Neisseria meningitidis serogroups A, B and C

The variation of cell adherence of meningococci serogroups A, B and C and influenza viruses was investigated in 11 animal species and in humans of different age groups (1st, 2nd, 3rd and 4th weeks; 2nd-3rd months; 4th-12th months, 2nd-3rd years; and 18th-60th years of life) as well as in women during pregnancy (17th-36th weeks) and childbirth. Red blood cells of all animals tested as well as of human newborns were absolutely resistant to attachment of meningococci. In neonatal and the later periods the human cells become far differently sensitive individually to meningococcal adhesion. In contrast, the viral adhesion was characterized by different individual cell sensitivity in all age groups tested. Pregnancy and childbirth did not influence the women's cell sensitivity to adhesion of Neisseria meningitidis. Different receptors are involved in interactions of human cells with influenza viruses and meningococci. The function of meningococcal receptors on human cells develops during postnatal ontogenesis. The variations express both specific (genetic) and ontogenetic (individual) differences in natural resistance to meningococcal infection.