Heat Shock Proteins: Classification, Functions and Expressions in Plants during Environmental Stresses.

Heat shock proteins assist in folding proteins that is a basic cellular constituent responsible for various crucial functions including protein assembly, transportation, folding in normal conditions and denaturation of proteins in stress and in other cellular function. Abiotic factors like increased temperature, drought and salinity negatively affect reproduction and survival of plants. Plants (HSPs), as chaperones, have crucial part in conversing biotic and abiotic stress tolerance. Plants react towards critical changes through biochemical, growth, and physiological mechanisms included expression of stress-reactive proteins, which are regulated by interconnected signaling cascades of transcription factors including heat stress TFs.

Analysis of Cellular Component Indicators of Immune Status of Rhesus Macaques

Objective. Selection of indicators of lymphocyte populations in rhesus macaques determined by flow cytometry to evaluate variations of cellular constituent of their immune status.Materials and methods. Blood of 11 healthy rhesus macaque males, 2,0–2,5 years old, weighing 2,5–3,0 kg, was used. Monkeys were examined simultaneously in each of 7 months of observation (since May till November). Immunophenotyping was conducted by FC500 cytofluorimeter using Affymetrix eBioscience monoclonal antibodies. The following cellular constituent indicators of immune status were differentiated: total T lymphocytes (phenotype CD2+CD20-); total B lymphocytes (phenotype CD2-CD20+); natural killer cells (phenotype CD2+CD56+); T helper cells (phenotype CD2+CD4+); cytotoxic T lymphocytes (phenotype CD2+CD8+); double-positive T lymphocytes (phenotype CD4+CD8+) and T lymphocytes positive by antigens CD2 and CD20 (phenotype CD2+CD20+).Results and discussion. Statistical analysis of the obtained results revealed the absence of the effect of research time factor on the stated indicators. To assess changes in the cellular constituent of immune status of rhesus macaques, it is possible to use indicators that are less variable: total T and B lymphocytes, T helper cells, cytotoxic T lymphocytes and T lymphocytes with phenotype (CD2+CD20+). The use of CD56 as a marker of natural killer cells of rhesus macaques is impractical due to its low expression and a small size of the population bearing this marker. The research results may form the basis of the normative indicators of the subpopulation cell composition of immune system in rhesus macaques, which will allow the study of infected animals when assessing the quality of medical products in relation to dangerous and particularly dangerous infections.

Atrazine and Mesotrione-Induced Oxidative Stress and Impact on Antioxidant Enzymes and Chlorophyll Contents in Bermudagrass

ABSTRACT: The effect of atrazine, mesotrione, and joint activity of atrazine plus mesotrione on pigment, lipid peroxidation, and antioxidant enzyme activity was studied. Atrazine and mesotrione treatments significantly reduced chlorophyll a (Chl a), chlorophyll b (Chl b), carotenoid concentrations, and protein content in bermudagrass (Cynodon dactylon L.) plants, whereas they significantly enhanced lipid peroxidation. The treatment of atrazine plus mesotrione caused greater phototoxic effect on bermudagrass than either herbicide alone, which was evident from the significantly decreased membrane stability noted as a function of the enhanced singlet oxygen and malondialdehyde (MDA) contents, as well as from the greater reduction in Chl a, Chl b, and carotenoid contents. Although bermudagrass activated the antioxidant enzymes catalase (CAT), peroxidase (POD), and glutathione S-transferase (GST), it was significantly injured after the herbicide treatments. Thus, results suggested that the enzymatic and non-enzymatic antioxidants of bermudagrass was overloaded after the treatment of atrazine plus mesotrione, and the reactive oxygen species (ROS) subsequently caused lipid peroxidation, pigment and protein degradation, as well as other cellular constituent damage.

Casp8p41 generated by HIV protease kills CD4 T cells through direct Bak activation

Previous studies have shown that human immunodeficiency virus (HIV) protease cleaves procaspase 8 to a fragment, termed Casp8p41, that lacks caspase activity but nonetheless contributes to T cell apoptosis. Herein, we show that Casp8p41 contains a domain that interacts with the BH3-binding groove of pro-apoptotic Bak to cause Bak oligomerization, Bak-mediated membrane permeabilization, and cell death. Levels of active Bak are higher in HIV-infected T cells that express Casp8p41. Conversely, targeted mutations in the Bak-interacting domain diminish Bak binding and Casp8p41-mediated cell death. Similar mutations in procaspase 8 impair the ability of HIV to kill infected T cells. These observations support a novel paradigm in which HIV converts a normal cellular constituent into a direct activator that functions like a BH3-only protein.

A MULTIPHASE MODEL OF TUMOR AND TISSUE GROWTH INCLUDING CELL ADHESION AND PLASTIC REORGANIZATION

The main aim of the paper is to embed the experimental results recently obtained studying the detachment force of single adhesion bonds in a multiphase model developed in the framework of mixture theory. In order to do that the microscopic information is upscaled to the macroscopic level to describe the dependence of some crucial terms appearing in the PDE model on the sub-cellular dynamics involving, for instance, the density of bonds on the membrane, the probability of bond rupture and the rate of bond formation. In fact, adhesion phenomena influence both the interaction forces among the constituents of the mixtures and the constitutive equation for the stress of the cellular components. Studying the former terms a relationship between interaction forces and relative velocity is found. The dynamics presents a behavior resembling the transition from epithelial to mesenchymal cells or from mesenchymal to ameboid motion, though the chemical cues triggering such transitions are not considered here. The latter terms are dealt with using the concept of evolving natural configurations consisting in decomposing in a multiplicative way the deformation gradient of the cellular constituent distinguishing the contributions due to growth, to cell rearrangement and to elastic deformation. This allows the description of situations in which if in some points the ensemble of cells is subject to a stress above a threshold, then locally some bonds may break and some others may form, giving rise to an internal reorganization of the tissue that allows to relax exceedingly high stresses.

New opportunities to dissect and manipulate plant processes

The use of transgenic plants has become a standard tool of experimental plant biology and is changing many approaches to plant improvement. The technology has greatly expanded the range of methods available to isolate and identify new plants genes, and has permitted great strides in understanding the mechanisms which regulate gene expression. In addition, the ability to use cloned genes to alter the functional expression of the gene in transgenic plants has created entirely novel opportunities to examine the biological role of virtually any cellular constituent.

Scanning electron microscopy of freeze-fractured prescapular lymph node of caprine

The lymphatic system is very important in the immunological activities of the body. Clinicians confirm the diagnosis of infectious diseases by palpating the involved cutaneous lymph node for changes in size, heat, and consistency. Clinical pathologists diagnose systemic diseases through biopsies of superficial lymph nodes. In many parts of the world the goat is considered as an important source of milk and meat products.The lymphatic system has been studied extensively. These studies lack precise information on the natural morphology of the lymph nodes and their vascular and cellular constituent. This is due to using improper technique for such studies. A few studies used the SEM, conducted by cutting the lymph node with a blade. The morphological data collected by this method are artificial and do not reflect the normal three dimensional surface of the examined area of the lymph node. SEM has been used to study the lymph vessels and lymph nodes of different animals. No information on the cutaneous lymph nodes of the goat has ever been collected using the scanning electron microscope.