Antibodies against calcium-regulating hormones in infectious-allergic forms of bronchial asthma

Antibodies to calcitonin, parathyroid hormone and cortisol are detected in acute stage of infection-caused bronchial asthma. The appearance of antibodies is paralleled by marked hypercalcaemia. The antibodies may bind excessive hormones in the blood, preventing further hormonal imbalance. Ten-day treatment with glucocorticoids decreased the amount of antibodies possibly due to normalization of hormonal secretion and restoration of their balance. As a result, calcium blood levels returned to normal.     

Delayed hypersensitivity and nonspecific cellular immunity. The cytotoxic activity of macrophages, natural and antibody-dependent killer cells

The experiment on (BALB/cXC57BL)F1 mice, showing a high level of delayed hypersensitivity (DH) when sensitized with BCG vaccine and Staphylococcus aureus strain B-243, has demonstrated the influence of such sensitization and DH reaction induced by the injection of a specific antigen (old tuberculin or staphylococcal phagolysate) into the sensitized animals on the cytotoxicity of macrophages, natural killers (NK) and antibody-dependent killers (ADK). Sensitization with BCG vaccine alone results in an insignificant rise in the activity of these effector cells, and sensitization with S. aureus produces no changes at all. The pronounced activation of the cytotoxicity of macrophages, NK and, to a lesser extent, ADK has been observed in DH reaction induced by the injection of a specific antigen into the sensitized mice. In the course of DH reaction a rise in the activity of NK and ADK not only against tumor target cells, but also against microbial ones (Candida albicans and S. aureus) has been found to occur.     

Water Balance in Cucumis Plants, Measured by Nuclear Magnetic Resonance, I

In this paper we demonstrate the study of plant water balanceby the non-invasive measurement of tissue water content andwater flow using proton nuclear magnetic resonance (NMR). Sapvelocity and flux were measured independently in the presenceof an excess of stationary tissue water. The instrumentationdescribed allows automated and unattended measurement of flow-and water content-variables in a well-defined region of theplant over periods of several days, with a time resolution betweensuccessive measurements of c. 5 s. Using this apparatus theeffect of changes in light intensity (day/night rhythm) andrelative humidity on stem tissue water content as well as onthe velocity and flux of xylem sap in the stem were investigatedin a cucumber plant. The results are in agreement with predictionsfrom a simple model for plant water balance, which is basedon water potential, flow rate and resistance to flow. As longas only transpiration is varied, flow rate and water content(or potential) are affected in opposite ways as demonstratedin this paper. In contrast, the model predicts that changesin uptake (resulting from changes in, for example, root resistance)will induce changes in water content and flow in the same direction.An experimental verification of this prediction is given ina subsequent paper, where, in addition, the NMR results arecompared to those obtained with a dendrometer. Key words: Water balance model, Cucumis sativus L., flow, water content, NMR, water balance measurement     

Recombinational analysis of a natural noncytopathic human immunodeficiency virus type 1 (HIV-1) isolate: role of the vif gene in HIV-1 infection kinetics and cytopathicity.

Two molecularly cloned coisolates of human immunodeficiency virus type 1 (HIV-1) have been found to exhibit different phenotypes of viral expression, either rapid and cytopathic (N1T-A virus) or delayed and noncytopathic (N1T-E virus [X. Ma, K. Sakai, F. Sinangil, E. Golub, and D. J. Volsky, Virology 176:184-194, 1990]). To identify the viral genetic elements responsible for these phenotypes, we prepared reciprocal recombinants in different regions of N1T-A and N1T-E viral genomes. Infectivity experiments with the recombinant viruses revealed that the rapid/cytopathic (N1T-A-like) phenotype assorted cleanly with the V1f-coding region and Vif expression. The smallest HIV-1 DNA region that conferred the complete phenotypic switch was a 284-bp NdeI-StuI fragment within the vif open reading frame. Nucleotide sequence analysis revealed a 35-bp deletion starting at nucleotide 218 in the N1T-E vif gene. A 23-kDa Vif protein was detected by immunoblotting using Vif-specific antiserum in extracts of cells infected with N1T-A but not N1T-E virus. No detectable vif protein was found in association with sedimented particles of either virus. Cotransfection of a eucaryotic vif expression plasmid with N1T-E DNA complemented the N1T-E defect; rapid/cytopathic infection similar to that in N1T-A-transfected cells was observed. We conclude that Vif controls the rate, and consequently the cytopathic outcome, of HIV-1 infection.     

Can Ca2+-dependent competence be repeatedly induced in the same Escherichia coli cells?

Summary With the help of devised multicycle consecutive transformation (MCT) it is shown that Ca²⁺-dependent competence can be repeatedly induced in the same population of Escherichia coli cells. The same fraction of cells is induced to competence and transformed during MCT. In contrast to the results on classical transformation with mixed DNA preparations, no double transformants are observed in MCT. The competent cells and transformants are found to be more fragile than nontransformed cells. The latter are represented presumably by the cells that have not absorbed exogenous plasmid DNA. The results suggest that there is strong interference between plasmid DNAs during MCT, and that the presence of exogenous DNA makes the cells more sensitive to the apparently harmful procedure of repeated competence induction.     

TASTE GROUP THRESHOLDS AND SENSORY EVALUATION OF SPANISH WINE VINEGARS

Wine vinegar is a product obtained from wine acidification which contains at least 5% by wt. of acetic acid, in general without any additives or colorings.
Aspects studied in this work include: the determination of the taste group thresholds (geometric mean of the individual best-estimate thresholds "BET") of two different acids (citric and acetic acids) in aqueous solution and spanish vinegars produced from table and sherry wines. The results obtained suggest that wine vinegar can be considered something more than just an acidulant agent.
In order to evaluate differences among wine vinegars, discriminant tests for twenty-five spanish vinegars (sherry, table and flavored vinegars) were applied. Six of the twelve attributes freely chosen by assessors allowed grouping of the spanish wine vinegars according to their sensory aspects.     

Arginine deprivation in KB cells: I. Effect on cell cycle progress

When exponentially growing KB cells were deprived of arginine, cell multiplication ceased after 12 h but viability was maintained throughout the experimental period (42-48 h). Although tritiated thymidine ([(3)H]TdR) incorporation into acid-insoluble material declined to 5 percent of the initial rate, the fraction of cells engaged in DNA synthesis, determined by autoradiography, remained constant throughout the starvation period and approximately equal to the synthesizing fraction in exponentially growing controls (40 percent). Continous [(3)H]TdR-labeling indicated that 80 percent of the arginine-starved cells incorporated (3)H at some time during a 48-h deprivation period. Thus, some cells ceased DNA synthesis, whereas some initially nonsynthesizing cells initiated DNA synthesis during starvation. Flow microfluorometric profiles of distribution of cellular DNA contents at the end of the starvation period indicated that essentially no cells had a 4c or G2 complement. If arginine was restored after 30 h of starvation, cultures resumed active, largely asynchronous division after a 16-h lag. Autoradiographs of metaphase figures from cultures continuously labeled with [(3)H]TdR after restoration indicated that all cells in the culture underwent DNA synthesis before dividing. It was concluded that the majority of cells in arginine-starved cultures are arrested in neither a normal G1 nor G2. It is proposed that for an exponential culture, i.e. from most positions in the cell cycle, inhibition of cell growth after arginine with withdrawal centers on the ability of cells to complete replication of their DNA.     

Two closely linked tomato HKT coding genes are positional candidates for the major tomato QTL involved in Na+/K+ homeostasis

The location of major quantitative trait loci (QTL) contributing to stem and leaf [Na⁺] and [K⁺] was previously reported in chromosome 7 using two connected populations of recombinant inbred lines (RILs) of tomato. HKT1;1 and HKT1;2, two tomato Na⁺‐selective class I‐HKT transporters, were found to be closely linked, where the maximum logarithm of odds (LOD) score for these QTLs located. When a chromosome 7 linkage map based on 278 single‐nucleotide polymorphisms (SNPs) was used, the maximum LOD score position was only 35 kb from HKT1;1 and HKT1;2. Their expression patterns and phenotypic effects were further investigated in two near‐isogenic lines (NILs): 157‐14 (double homozygote for the cheesmaniae alleles) and 157‐17 (double homozygote for the lycopersicum alleles). The expression pattern for the HKT1;1 and HKT1;2 alleles was complex, possibly because of differences in their promoter sequences. High salinity had very little effect on root dry and fresh weight and consequently on the plant dry weight of NIL 157‐14 in comparison with 157‐17. A significant difference between NILs was also found for [K⁺] and the [Na⁺]/[K⁺] ratio in leaf and stem but not for [Na⁺] arising a disagreement with the corresponding RIL population. Their association with leaf [Na⁺] and salt tolerance in tomato is also discussed.     

Production of endothelial progenitor cells obtained from human Wharton's jelly using different culture conditions

Endothelial progenitor cells (EPC) participate in revascularization and angiogenesis. EPC can be cultured in vitro from mononuclear cells of peripheral blood, umbilical cord blood or bone marrow; they also can be transdifferentiated from mesenchymal stem cells (MSC). We isolated EPCs from Wharton's jelly (WJ) using two methods. The first method was by obtaining MSC from WJ and characterizing them by flow cytometry and their adipogenic and osteogenic differentiation, then applying endothelial growth differentiating media. The second method was by direct culture of cells derived from WJ into endothelial differentiating media. EPCs were characterized by morphology, Dil-LDL uptake/UEA-1 immunostaining and testing the expression of endothelial markers by flow cytometry and RT-PCR. We found that MSC derived from WJ differentiated into endothelial-like cells using simple culture conditions with endothelium induction agents in the medium.