A study of the selective inhibition by urea of neutrophil alkaline phosphatase isoenzymes

The kinetics of neutrophil alkaline phosphatase (AP) inactivation by urea were examined. In standardized conditions (molarity and pH of buffer, magnesium chloride and urea concentration), monitoring of the enzymatic reaction allows identification of neutrophil AP isoenzymes. This study confirms the heterogeneity of AP in normal human neutrophils.     

Enzyme polymorphisms of Ideles populations (Ahaggar, Algeria) and the Iwellemeden Kel Kummer Twaregs (Menaka, Mali).

Surveys dealing with enzyme polymorphisms have recently been conducted in the Sahara. Results from two populations are reported here: 227 inhabitants of Ideles village (Ahaggar, Algeria); 285 nomads of a genetic isolate, the Kel Kummer Twareg tribe (Menaka, Mali). The four classical molecular variants of G6PD:A+, A-, B+, B-, are found in Ideles. The frequency of the G6PD A+ Negroid variant reaches 15% in Ideles and 7.7% among the Kel Kummer. However, gene frequencies will have to be recalculated after a study of the genetic transmission through families. The PGDC gene of 6PGD is especially frequent in the Kel Kummer where 10 'Canning' phenotypes have been observed. The PGM distribution of alleles at locus 1 in Ideles is the same as in the Mediterranean populations. The pa gene of acid phosphatase, relatively frequent in Ideles, has been excluded by drift from the Kel Kummer gene pool. AK and LDH enzymes have also been studied in both samples. The abnormal Ea1 mutation of serum pseudocholinesterase exists in Ideles and in the Kel Kummer as in other populations of the Sahara; the C5 esterase component was revealed by electrophoresis in 5% of the Kel Kummer people.     

Alkaline phosphatase and phosphotyrosine phosphatase activities of cultured amniotic cells with trisomy 18.

In cultured amniotic cells from fetuses with Edward's syndrome (trisomy 18), the activities of two protein phosphatases, alkaline phosphatase and phosphotyrosine phosphatase, were measured. Comparison with normal fetal cells showed a different behavior for each enzyme. Alkaline phosphatase was significantly lowered while phosphotyrosine phosphatase remained at normal levels. The interest of these enzyme assays in the screening procedure of this severe chromosome defect is discussed.     

cDNA to chick lumican (corneal keratan sulfate proteoglycan) reveals homology to the small interstitial proteoglycan gene family and expression in muscle and intestine.

A 1.9-kb cDNA clone to chick lumican (keratan sulfate proteoglycan) was isolated by screening an expressing vector library made from chick corneal RNA with antiserum to chick corneal lumican. The cDNA clone contained an open reading frame coding for a 343-amino acid protein, Mr = 38,640. Structural features of the deduced sequence include: a 18-amino acid signal peptide, cysteine residues at the N- and C-terminal regions, and a central leucine-rich region (comprising 62% of the protein) containing nine repeats of the sequence LXXLXLXXNXL/I, where X represents any amino acid. Lumican contains three variations of this sequence that are tandemly linked to form a unit and three units tandemly linked to form the leucine-rich region. The sequential arrangement of these repeats and their spacing suggest that this region arose by duplication. The deduced sequence shows five potential N-linked glycosylation sites, four of which are in the leucine-rich region. These sites are also potential keratan sulfate attachment sites. The cDNA clone to lumican hybridizes to a 2.0-kb mRNA found in tissues other than cornea, predominantly muscle and intestine. Radiolabeling and immunoprecipitation studies show that lumican core protein is also synthesized by these tissues. The primary structure of lumican is similar to fibromodulin, decorin, and biglycan, which indicates it belongs to the small interstitial proteoglycan gene family. The expression of lumican in tissues other than cornea indicates a broader role for lumican besides contributing to corneal transparency.     

Properties of a basement membrane-related glycoprotein synthesized in culture by a mouse embryonal carcinoma-derived cell line.

Two glycoproteins, GP-1 and GP-2, have been isolated from an extracellular membrane synthesized in cell culture by an embryonal carcinoma-derived cell line. The amino acid and carbohydrate compositions have been determined. Both proteins are rich in half-cystine residues and contain approximately 12-15% carbohydrate. Antibodies have been obtained against one of the glycoproteins, GP-2, in rabbits. The antibody reacts with basement membranes from adult mouse and human kidney glomeruli and tubules, and all basement membranes tested from mouse embryonic tissues. The molecular properties of GP-2 are superficially similar to LETS protein; however, immunological and other criteria show that they are distinct proteins. The presence of LETS protein and GP-2 in basement membranes suggests that there are subtle interactions which are important in adhesion of epithelial cells to basement membranes.     

Erythrocyte glucose-6-phosphate dehydrogenase in the Niokolonko (Malinke of the Niokolo) of Eastern Senegal. Identification of a slow variant with normal activity (Tacoma-like).

In a survey of blood genetic markers in the Niokolonko of Eastern Senegal, three types of G6PD variants were discovered: (1) fast variants, common Negro G6PD A +; the frequency of the Gd A + gene was 0.183; (2) deficient G6PD A--, occurring with a fairly low frequency: 0.079, and (3) some individuals were carriers of a slow moving electrophoretic variant with normal activity. After purification, the analysis of kinetic parameters showed that this enzyme was closely similar to G6PD Tacoma. We proposed to label it 'G6PD Tacoma-like'. The incidence of this mutation in the whole group studied was 0.020. G6PD Tacoma-like may be common in some African tribes.     

Evolutionary trade-offs at the Arabidopsis WRR4A resistance locus underpin alternate Albugo candida race recognition specificities

The oomycete Albugo candida causes white rust of Brassicaceae, including vegetable and oilseed crops, and wild relatives such as Arabidopsis thaliana. Novel White Rust Resistance (WRR) genes from Arabidopsis enable new insights into plant/parasite co-evolution. WRR4A from Arabidopsis accession Columbia (Col-0) provides resistance to many but not all white rust races, and encodes a nucleotide-binding, leucine-rich repeat immune receptor. Col-0 WRR4A resistance is broken by AcEx1, an isolate of A. candida. We identified an allele of WRR4A in Arabidopsis accession Øystese-0 (Oy-0) and other accessions that confers full resistance to AcEx1. WRR4A^Oy-0 carries a C-terminal extension required for recognition of AcEx1, but reduces recognition of several effectors recognized by the WRR4A^Col-0 allele. WRR4A^Oy-0 confers full resistance to AcEx1 when expressed in the oilseed crop Camelina sativa.     

Effect of a Bacillus subtilis strain on flax protection against Fusarium oxysporum and its impact on the root and stem cell walls

In Normandy, flax is a plant of important economic interest because of its fibres. Fusarium oxysporum, a telluric fungus, is responsible for the major losses in crop yield and fibre quality. Several methods are currently used to limit the use of phytochemicals on crops. One of them is the use of plant growth promoting rhizobacteria (PGPR) occurring naturally in the rhizosphere. PGPR are known to act as local antagonists to soil‐borne pathogens and to enhance plant resistance by eliciting the induced systemic resistance (ISR). In this study, we first investigated the cell wall modifications occurring in roots and stems after inoculation with the fungus in two flax varieties. First, we showed that both varieties displayed different cell wall organization and that rapid modifications occurred in roots and stems after inoculation. Then, we demonstrated the efficiency of a Bacillus subtilis strain to limit Fusarium wilt on both varieties with a better efficiency for one of them. Finally, thermo‐gravimetry was used to highlight that B. subtilis induced modifications of the stem properties, supporting a reinforcement of the cell walls. Our findings suggest that the efficiency and the mode of action of the PGPR B. subtilis is likely to be flax variety dependent.     

A Phase 1b Randomized,Controlled, Double-Blinded Dosage-Escalation Trial to Evaluate the Safety,Reactogenicity and Immunogenicity of an Adenovirus Type 35 Based Circumsporozoite Malaria Vaccine in Burkinabe Healthy Adults 18 to 45 Years of Age

Background

Ad35.CS.01 is a pre-erythrocytic malaria candidate vaccine. It is a codon optimized nucleotide sequence representing the P. falciparum circumsporozoite (CS) surface antigen inserted in a replication deficient Adenovirus 35 backbone. A Phase 1a trial has been conducted in the USA in naïve adults and showed that the vaccine was safe. The aim of this study is to assess the safety and immunogenicity of ascending dosages in sub Saharan Africa.

Methods

A double blind, randomized, controlled, dose escalation, phase Ib trial was conducted in a rural area of Balonghin, the Saponé health district (Burkina Faso). Forty-eight healthy adults aged 18-45 years were randomized into 4 cohorts of 12 to receive three vaccine doses (day 0, 28 and 84) of 10⁹, 10¹⁰, 5X10¹⁰, 10¹¹ vp of Ad35.CS.01 or normal saline by intra muscular injection. Subjects were monitored carefully during the 14 days following each vaccination for non serious adverse events. Severe and serious adverse events were collected throughout the participant study duration (12 months from the first vaccination). Humoral and cellular immune responses were measured on study days 0, 28, 56, 84, 112 and 140.

Results

Of the forty-eight subjects enrolled, forty-four (91.7%) received all three scheduled vaccine doses. Local reactions, all of mild severity, occurred in thirteen (27.1%) subjects. Severe (grade 3) laboratory abnormalities occurred in five (10.4%) subjects. One serious adverse event was reported and attributed to infection judged unrelated to vaccine. The vaccine induced both antibody titers and CD8 T cells producing IFNγ and TNFα with specificity to CS while eliciting modest neutralizing antibody responses against Ad35.

Conclusion

Study vaccine Ad35.CS.01 at four different dose levels was well-tolerated and modestly immunogenic in this population. These results suggest that Ad35.CS.01 should be further investigated for preliminary efficacy in human challenge models and as part of heterologous prime-boost vaccination strategies.

Trial Registration

ClinicalTrials.gov NCT01018459 http://clinicaltrials.gov/ct2/show/NCT01018459