Immunostimulating properties of synthetic derivatives of muramyl dipeptide and glucosaminyl muramyl dipeptide in vitro

Production of tumor necrosis factor (TNF) and interleukin-1 (IL-1) by macrophages of the spleen and peritoneal exudate of mice as well as cytotoxic factors (CFs) by murine splenocytes after in vitro activation was estimated. All the derivatives of muramyldipeptide (MDP) and glucosaminylmuramyldipeptide (GMDP) were able to induce production of TNF and CFs. In the presence of lipopolysaccharide (LPS), the effect was always higher. The response of the spleen macrophages to the effect of the preparations was higher than that of the peritoneal ones and ++non-fractionated splenocytes. GMDP and GMDP4 especially in the presence of LPS had the highest effect on induction of IL-1 by the murine peritoneal macrophages. On the contrary, MDP induced higher IL-1 synthesis by the spleen macrophages. The most active substances with respect to production of TNF, CFs and IL-1, i.e. MDP3 and GMDP4, might be recommended for immunotherapy of syngeneic tumors in animals.     

The asymmetry of the free amino acid pool in sections of the rat brain

The content of free amino acid pool in symmetric regions of cortex, hypothalamus, midbrain and blood of rats which had produced the movement conditioned reflex strengthened by feeding was studied. It was established that the "untrained" rats have higher content of free amino acid pool in their blood. The brain of the experimental animals revealed the biochemical asymmetry which was marked by the differences in free amino acid pool distribution between the left and right halves of the studied regions of brain. It was shown that left sided asymmetry animals i.e. animals with heightened content of free amino acid pool in the left half of the brain dominated in the "untrained" group of rats. The supposition was expressed that this biochemical asymmetry may contribute to the ability of animals to learn.     

Partial characterization ofAspergillus fumigatus polygalacturonases for the degumming of natural fibers

Summary Aspergillus fumigatus strain 4, cultured on citrus pectin as the sole carbon source, produced polygalacturonases whose activity was optimum at 65°C and pH 3.5–4.5. The enzymes presented a bimodal thermostability for 10 min, but not 60 min, of incubation. Polygalacturonases showed pH stability between 3.0 to 9.0. The enzymes were stable when stored at 4–6°C for 90 days, but their activity was reduced by 24% when they were stored at 26–30°C. Orange pulp was the best pectic carbon source tested for the production of pectinases capable of retting ramie fibers. The reutilization of these enzymes was possible, suggesting the viability of industrial use of pectinases for degumming ramie fibers.     

Loss of hydrogen atoms in H<Subscript>2</Subscript> plasma on the surfaces of materials used in EUV lithography

Low-pressure hydrogen is an important component of the working medium in extreme ultraviolet (EUV) projection lithography. Under the action of EUV photons and fast secondary electrons on the gas medium, plasma and atomic hydrogen, actively interacting with the surface, are produced. This interaction is very important, because it largely determines the lifetime of the multilayered EUV optics. In this study, the loss of atomic hydrogen under the conditions of a low pressure (<10 Torr) RF plasma discharge on the surfaces of materials used in EUV lithography is investigated. The surface loss probabilities of H atoms on these materials are measured. It is shown that surface recombination of atomic hydrogen goes according to the Eley-Rideal mechanism via direct recombination of H atoms from the gas phase with chemically and physically adsorbed atoms. In this case, the surface recombination probability is mainly determined by the density of chemical adsorption sites. The density of adsorption sites and the desorption energy of H atoms are estimated. The desorption energy of physically adsorbed H atoms on pure metal surfaces (or surfaces exposed to plasma) is about 0.5 eV, and the density of sorption sites is close to the surface density of atoms. This results in a high loss probability of H atoms on metals (∼0.1). Therefore, to provide efficient transportation of hydrogen atoms, it is necessary to use materials with the lowest loss probability of H atoms, i.e., dielectrics.     

Beginning to understand the role of sugar carriers in Colletotrichum lindemuthianum: the function of the gene mfs1

Fungi of the Colletotrichum genus are among the most prominent phytopathogens that cause diseases with a considerable economic impact, such as anthracnose. The hemibiotrophic fungus Colletotrichum lindemuthianum (teleomorph Glomerella cingulata f. sp. phaseoli) is the causal agent of the anthracnose of the common bean; and similarly to other phytopathogens, it uses multiple strategies to gain access to different carbon sources from its host. In this study, we examine mfs1, a newly identified C. lindemuthianum hexose transporter. The mfs1 gene is expressed only during the necrotrophic phase of the fungus’ interaction within the plant and allows it to utilize the available sugars during this phase. The deletion of mfs1 gene resulted in differential growth of the fungus in a medium that contained glucose, mannose or fructose as the only carbon source. This study is the first to describe a hexose transporter in the hemibiotrophic pathogen C. lindemuthianum and to demonstrate the central role of this protein in capturing carbon sources during the necrotrophic development of the plant/pathogen interaction.     

Specificity of the rapid rK39 antigen-based immunochromatographic test Kalazar Detect(r) in patients with cutaneous leishmaniasis in Brazil

The aim of this study was to evaluate the specificity of a rapid immunochromatographic test that was developed to detect antibodies against the rK39 antigen for the diagnosis of visceral leishmaniasis (VL). This evaluation was performed using sera from patients with a confirmed diagnosis of active cutaneous leishmaniasis. The sera from 272 patients with a confirmed diagnosis of localised cutaneous leishmaniasis (CL) who resided in an area endemic for Leishmania braziliensis in Brazil were obtained before the initiation of antileishmanial treatment. Kalazar Detect^(r)(InBios, Seattle, WA) recombinant K39 antigen-based immunochromatographic strips were used according to the manufacturer''s instructions. The test results were evaluated independently by two examiners in sequential order. The positive controls for the test included five serum samples from five patients with parasitologically confirmed diagnosis of VL caused by Leishmania infantum in Brazil. Overall, 100% of the samples obtained from patients with CL were negative, confirming the absence of a serological cross-reaction for individuals with cutaneous disease when these patients were evaluated using the rapid test. The lack of a cross-reaction in patients who were infected by parasites of the same genus highlights the specificity of the rK39 antigen for the diagnosis of VL in areas with the sympatric circulation of L. braziliensis and L. infantum.     

In Vivo Quantitative Assessment of Myocardial Structure,Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most importantly, with the development of a novel preclinical iodinated contrast agent called eXIA160, functional and metabolic assessment of the heart became possible. However, prior to the advent of commercial MicroCT scanners equipped with X-ray flat-panel detector technology and easy-to-use cardio-respiratory gating, preclinical studies of cardiovascular disease (CVD) in small animals required a MicroCT technologist with advanced skills, and thus were impractical for widespread implementation. The goal of this work is to provide a practical guide to the use of the high-speed Quantum FX MicroCT system for comprehensive determination of myocardial global and regional function along with assessment of myocardial perfusion, metabolism and viability in healthy mice and in a cardiac ischemia mouse model induced by permanent occlusion of the left anterior descending coronary artery (LAD).     

Detection of Mycobacterium leprae DNA by polymerase chain reaction in the blood and nasal secretion of Brazilian household contacts

DNA samples from blood and nasal swabs of 125 healthy household contacts was submitted to amplification by polymerase chain reaction (PCR) using a Mycobacterium leprae-specific sequence as a target for the detection of subclinical infection with M. leprae. All samples were submitted to hybridization analysis in order to exclude any false positive or negative results. Two positive samples were confirmed from blood out of 119 (1.7%) and two positive samples from nasal secretion out of 120 (1.7%). The analysis of the families with positive individuals showed that 2.5% (n = 3) of the contacts were relatives of multibacilary patients while 0.8% of the cases (n = 1) had a paucibacilary as an index case. All positive contacts were followed up and after one year none of them presented clinical signs of the disease. In spite of the PCR sensitivity to detect the presence of the M. leprae in a subclinical stage, this molecular approach did not seem to be a valuable tool to screen household contacts, since we determined a spurious association of the PCR positivity and further development of leprosy.