Phototaxis of chloroplasts as a criterion of viability of leaf parenchyma

Summary It has been shown that phototaxis of chloroplasts may be used as a criterion of the degree of injury in leaf parenchyma of many plant species. This method was applied here to determine heat resistance of leaf parenchyma, its resistance to ethanol and high hydrostatic pressure and also to characterize reversibility and heat hardening.     

The adaptive potential of human immunity during strength training

Quantitative and functional characteristics of human T-and B-cell-related immunity and natural cytotoxicity were studied during nine-week strength training. Long-term classic strength training and low-intensity strength training without relaxation did not change the peripheral blood contents of the main subpopulations of immunocompetent cells, the phytohemagglutinin-induced proliferative activity of T lymphocytes, serum levels of immunoglobulins A, M, and G (IgA, IgM, and IgG, respectively) and the cytotoxic activity of natural killer cells. At the same time, training was accompanied by activation of the immune system, which was evident from increased counts of CD25⁺ lymphocytes observed in the peripheral blood and in the mitogen-stimulated and nonstimulated cell cultures, as well as from the higher spontaneous and mitogen-induced productions of IgA, IgM, and IgG by B lymphocytes.     

Luminescence Enhancement and SERS by Self-Assembled Plasmonic Silver Nanostructures in Nanoporous Glasses

It was shown experimentally that the action of continuous electric field on nanoporous silicate glasses with interconnecting pores, containing silver nanoparticles, leads to the spatial redistribution of nanoparticles. The concentration of nanoparticles near the negative electrode increases and results in silver nano- and microdendrite structure growth. The main mechanisms of the described effects are the field emission of silver ions from silver nanoparticles near negative electrode, migration of silver ions in the external electric field to the negative electrode, reduction of silver ions by free electrons, and new silver nanoparticle formation. The experiments have shown that at the ends of microdendrites, local field enhancement appears, which results in luminescence enhancement and in SERS.

     

Population dynamics of mites of the family pyroglyphidae and micromycetes in laboratory cultures

Original data on the study of the population dynamics in allergenic house dust mites of the family Pyroglyphidae (Dermatophagoides pteronyssinus (Trouessart 1897) and D. farinae Hughes 1961) during long (37 weeks) joint cultivation with the micromycetes Aspergillus penicillioides Speg. in simple periodical cultures without addition of food (SPC) with different initial population density of mites are given. The micromycete A. penicillioides Speg., dominating in laboratory cultures of pyroglyphids, was cultivated in parallel without mites. It was found that during joint cultivation of A. penicillioides and mites, population dynamics of D. pteronyssinus and D. farinae in SPC depended on the initial population density of mites, which affected the duration of mite developmental stages and the degree of the maximal population density. Cultures of D. farinae developed more rapidly than cultures of D. pteronyssinus, independently of the initial population density (50 or 200 specimens per gram of the substrate). A high degree of the initial population density in both mite species resulted in the shortening of the lag-phase, in more rapid reaching of the maximal population density, and in the higher degree of the maximal population density. Population density of the fungus A. penicillioides did not depend on the presence of both mite species. On the basis of our own data and literary analysis, we assume that A. penicillioides can affect the ability of mites to explore the trophic substrate, the rate of the population development, and the degree of their maximal population density. Mites, in their turn, did not significantly affect the development of A. penicillioides in our experiments.     

Age-Related Changes in Turn–Amplitude Characteristics of the EMG Recorded during Graded Isometric Contraction

The number of turns, the mean amplitude, and the peak ratio of the electromyogram (EMG) recorded in m. biceps brachii at different levels of isometric contraction were analyzed in nine age groups (from 1 month to 72 years, N = 192). Regression equations describing the age-related changes in number of EMG turns and mean EMG amplitude were respectively y = –A(2.48 ± 0.14) – M(1.32 ± 0.17) + B(11.02 ± 0.68) + (194.71 ± 7.81) (P < 0.001) and y = –A(2.47 ± 0.19) – M(1.87 ± 0.23) + B(10.03 ± 0.88) + (321.57 ± 11.05) (P < 0.001), where A is the age, years; M is the body mass, kg; and B is the load, kg. With increasing age, the interference EMG tended to assume a so-called neurogenic form as a result of age-specific organization of motor functions at the segmental level.     

Detection of bone marrow-derived cells in neointimal thickening in the rat carotid artery by nested polymerase chain reaction

The bone marrow origin of cells involved in neointimal formation after injury of the luminal surface of the vessel was confirmed by highly sensitive nested polymerase chain reaction on isolated vascular wall cells. The model of intimal hyperplasia after balloon angioplasty of the carotid artery in radiation bone marrow chimeras between male and female Wistar rats was used. The Y chromosomes of rat male donors of the bone marrow for irradiated females were used as a marker of bone marrow-derived cells. This approach demonstrated a bone marrow origin of a large fraction of α-actin-positive (smooth muscle) neointimal cells.     

Methods of assessment and control of house dust mites population and mite allergen exposure

The work is devoted to analysis of various methods of assessment and control of house dust mites population and mite allergens in city dwellings using own results and the literature data. Data about in-house dust mites biology and ecology, mechanisms of their migration and circulation in modern city conditions are presented. The comparison of several methods of mites number assessment and mite allergens exposure (classical acarological analysis, colorimetric method of guanine detection in house dust, immunochemical methods) has been performed and their advantages and disadvantages analyzed. As choice of adequate avoidance measures is one of the key question, various such measures (mechanical, physical and chemical) have been compared.