Properties of recombinant NADP-malate dehydrogenases from Sorghum vulgare leaves expressed in Escherichia coli cells

In this study, a cDNA clone coding for sorghum leaf NADP-malate dehydrogenase [Crétin, C., Luchetta, P., Joly, C., Decottignies, P., Lepiniec, L., Gadal, P., Sallantin, M., Huet, J. C. & Pernollet, J. C. (1990) Eur. J. Biochem. 192, 299-303] was used either in the full-length form or in a shorter form deprived of the 5' end coding for the transit peptide. Both cDNA fragments were cloned into the expression vector pKK233-2 and the resulting constructions were used to transform E. coli cells. The bacterial cells which do not contain any NADP-dependent malate dehydrogenase before transformation were able to express the protein after transformation and induction, as detected both by activity measurements and by immunoblot. The recombinant proteins could be purified to homogeneity and their biochemical characteristics studied. They were identical to those of the enzyme isolated from corn or sorghum leaves, including the well known redox regulatory properties. The NADP-malate dehydrogenases derived from both constructions had a similar subunit size and the analysis of their N-terminal sequences revealed that E. coli cells were able to recognize the processing signal of the precursor polypeptide and to mature and assemble the protein in a manner similar to higher plants.     

Some electron microscopy characteristics of lung immune response in the rats stimulated by respiratory and parenteral ways with pneumococcal suspensions

Conventional albino rats of either sexes, weighing about 100 grams, were stimulated, one group by inhalation of pulverized suspensions of living type III pneumococci, in 6 exposures, and the second group, by 5 intramusculary injections, one a week, of 0,1 ml, emulision of killed germs, in complete Freund's adjuvant submitted after a week free interval to the inhalation of aerosolized living pneumococci. The tissue fragments sampled at two and respective five weeks after the beginning of the experiment, from central and peripherical sites of lungs, inclusively from a control group, were fixed in glutaraldehide-osmic acid and prepared for electron-microscopical examination. In the thickened, densely cellular alveolar walls there are numerous mature plasma cells, intermediate elements between reticular septal cells and plasmablast and also histiocytic cells which phagocytic inclusions and shape suggests their movement in the interalveolar septa. The swollen free alveolar macrophages contain an increased number of lysosomes and ribosomes. The hyperplastic granular pneumocytes possess enlarged cytosomes excreting osmiophilic material in the air spaces. There are discussed the problems of local plasma cell differentiation, alveolar macrophage physiology and transparietal migration of histiocytes.     

Maternal origin of a de novo balanced t(21q21q) identified by ets-2 polymorphism

Summary Molecular investigations were done in a woman with a de novo balanced t(21q21q) discovered because of the birth of a trisomic 21 baby. Polymorphisms detected with probe ets-2 after MspI digestion showed that both chromosomes 21 involved in the rearrangement were of maternal origin. The most likely hypothesis is that of a disomic 21 oocyte fertilized by a nullisomic 21 sperm.     

A sensitive sandwich enzyme immunoassay for calcitonin gene-related peptide (CGRP): characterization and application.

Thirty mouse monoclonal antibodies (mAbs) directed against rat calcitonin gene-related peptide-alpha (CGRP-alpha) have been obtained. These mAbs are classified in 2 groups, one recognizing the peptide N-terminus and the other binding the C-terminus. A two-site immunometric assay was developed using mAb CGRP-83 as capture antibody, whereas mAb CGRP-72 acts as tracer, covalently labeled with enzyme acetylcholinesterase. This assay appeared sensitive (limit of detection: 2 pg/ml) and precise, allowing quantitative measurement of all human and murine CGRP isoforms. The assay was used to determine specific concentrations of CGRP in different rat, mice and guinea pig samples. The validity of the test was demonstrated by HPLC fractionation experiments.     

Microbial and biochemical basis of a Fusarium wilt-suppressive soil

Crops lack genetic resistance to most necrotrophic pathogens. To compensate for this disadvantage, plants recruit antagonistic members of the soil microbiome to defend their roots against pathogens and other pests. The best examples of this microbially based defense of roots are observed in disease-suppressive soils in which suppressiveness is induced by continuously growing crops that are susceptible to a pathogen, but the molecular basis of most is poorly understood. Here we report the microbial characterization of a Korean soil with specific suppressiveness to Fusarium wilt of strawberry. In this soil, an attack on strawberry roots by Fusarium oxysporum results in a response by microbial defenders, of which members of the Actinobacteria appear to have a key role. We also identify Streptomyces genes responsible for the ribosomal synthesis of a novel heat-stable antifungal thiopeptide antibiotic inhibitory to F. oxysporum and the antibiotic''s mode of action against fungal cell wall biosynthesis. Both classical- and community-oriented approaches were required to dissect this suppressive soil from the field to the molecular level, and the results highlight the role of natural antibiotics as weapons in the microbial warfare in the rhizosphere that is integral to plant health, vigor and development.     

Structure of the Tetramerization Domain of Measles Virus Phosphoprotein

The atomic structure of the stable tetramerization domain of the measles virus phosphoprotein shows a tight four-stranded coiled coil. Although at first sight similar to the tetramerization domain of the Sendai virus phosphoprotein, which has a hydrophilic interface, the measles virus domain has kinked helices that have a strongly hydrophobic interface and it lacks the additional N-terminal three helical bundles linking the long helices.     

Classification of prostate magnetic resonance spectra using Support Vector Machine

Prostate cancer is the most common cancer in men over 50 years of age and it has been shown that nuclear magnetic resonance spectra are sensitive enough to distinguish normal and cancer tissues. In this paper, we propose a classification technique of spectra from magnetic resonance spectroscopy. We studied automatic classification with and without quantification of metabolite signals. The dataset is composed of 22 patient datasets with a biopsy-proven cancer, from which we extracted 2464 spectra from the whole prostate and of which 1062 were localised in the peripheral zone. The spectra were manually classed into 3 different categories by a spectroscopist with 4 years experience in clinical spectroscopy of prostate cancer: undetermined, healthy and pathologic. We used different preprocessing methods (module, phase correction only, phase correction and baseline correction) as input for Support Vector Machine and for Multilayer Perceptron, and we compared the results with those from the expert. If we class only healthy and pathologic spectra we reach a total error rate of 4.51%. However, if we class all spectra (undetermined, healthy and pathologic) the total error rate rises to 11.49%. We have shown in this paper that the best results are obtained using the pre-processed spectra without quantification as input for the classifiers and we confirm that Support Vector Machine are more efficient than Multilayer Perceptron in processing high dimensional data.