Molecular biodiversity of arbuscular mycorrhizal fungi in trace metal-polluted soils

We assessed the indigenous arbuscular mycorrhizal fungi (AMF) community structure from the roots and associated soil of Plantago major (plantain) plants growing on sites polluted with trace metals (TM) and on unpolluted sites. Uncontaminated and TM-contaminated sites containing As, Cd, Cu, Pb, Sn and Zn were selected based on a survey of the TM concentration in soils of community gardens in the City of Montréal. Total genomic DNA was extracted directly from these samples. PCR followed by denaturing gradient gel electrophoresis (PCR-DGGE), augmented by cloning and sequencing, as well as direct sequencing techniques, was all used to investigate AMF community structure. We found a decreased diversity of native AMF (assessed by the number of AMF ribotypes) in soils and plant roots harvested from TM-polluted soils compared with unpolluted soils. We also found that community structure was modified by TM contamination. Various species of Glomus, Scutellospora aurigloba and S. calospora were the most abundant ribotypes detected in unpolluted soil; ribotypes of G. etunicatum, G. irregulare/G. intraradices and G. viscosum were found in both polluted and unpolluted soils, while ribotypes of G. mosseae and Glomus spp. (B9 and B13) were dominant in TM-polluted soils. The predominance of G. mosseae in metal-polluted sites suggests the tolerance of this species to TM stress, as well as its potential use for phytoremediation. These data are relevant for our understanding of how AMF microbial communities respond to natural environments that contain a broad variety of toxic inorganic compounds and will substantially expand our knowledge of AMF ecology and biodiversity.     

Synthesis of selenium-containing amino acid analogues and their biological study

Synthesis of selenium-containing amino acid analogues is described. These compounds were prepared in a concise and short synthetic route in good yields by nucleophilic substitution reaction of pyridineselenol and quinolineselenol derivatives with N-phthaloylglycyl chloride followed by hydrazinolysis. The newly synthesized compounds were screened against different strains of bacteria and fungi.     

Clinical and molecular characterization of a combined 17p13.3 microdeletion with partial monosomy 21q21.3 in a 26-year-old man

We led a clinical and molecular characterization of a patient with mild mental delay and dysmorphic features initially referred for cytogenetic exploration of an azoospermia. We employed FISH and array CGH techniques for a better definition and refinement of a double chromosome aberration associating a 17p microdeletion with partial monosomy 21q due to 1:3 meiotic segregation of a maternal reciprocal translocation t(17;21)(p13.3;q21.2) revealed after banding analysis. Brain MRI depicted partial callosal and mild diffuse cerebral atrophies, but without expected signs of lissencephaly. The patient's karyotype formula was: 45,XY,der(17)t(17;21)(p13.3;q21.2)mat,-21. FISH study confirmed these rearrangements and array CGH analysis estimated the loss sizes to at least 635 kb on chromosome 17 and to 15.6 Mb on chromosome 21. The absence of lissencephaly and major brain malformations often associated with 17p terminal deletions could be attributed to the retention of PAFAH1B1, YWHAE and CRK genes. Dysmorphic features, moderate mental impairment and minor brain malformations could result from the 21q monosomy and particularly the partial deletion of the APP-SOD1 region. Azoospermia should result from gamete apoptosis induced by a control mechanism triggered in response to chromosome imbalances. Our study provides an additional case for better understanding and delineating both 17p and 21q deletions.     

Efficacy and safety of artemether in the treatment of chronic fascioliasis in Egypt: exploratory phase-2 trials

Background

Fascioliasis is an emerging zoonotic disease of considerable veterinary and public health importance. Triclabendazole is the only available drug for treatment. Laboratory studies have documented promising fasciocidal properties of the artemisinins (e.g., artemether).

Methodology

We carried out two exploratory phase-2 trials to assess the efficacy and safety of oral artemether administered at (i) 6×80 mg over 3 consecutive days, and (ii) 3×200 mg within 24 h in 36 Fasciola-infected individuals in Egypt. Efficacy was determined by cure rate (CR) and egg reduction rate (ERR) based on multiple Kato-Katz thick smears before and after drug administration. Patients who remained Fasciola-positive following artemether dosing were treated with single 10 mg/kg oral triclabendazole. In case of treatment failure, triclabendazole was re-administered at 20 mg/kg in two divided doses.

Principal Findings

CRs achieved with 6×80 mg and 3×200 mg artemether were 35% and 6%, respectively. The corresponding ERRs were 63% and nil, respectively. Artemether was well tolerated. A high efficacy was observed with triclabendazole administered at 10 mg/kg (16 patients; CR: 67%, ERR: 94%) and 20 mg/kg (4 patients; CR: 75%, ERR: 96%).

Conclusions/Significance

Artemether, administered at malaria treatment regimens, shows no or only little effect against fascioliasis, and hence does not represent an alternative to triclabendazole. The role of artemether and other artemisinin derivatives as partner drug in combination chemotherapy remains to be elucidated.     

Glutathione S-transferase M1, T1 and P1 polymorphisms and bladder cancer risk in Egyptians

Previous studies suggest that bladder cancer risk may vary with GST genotype but these results are inconsistent. The aim of this study was to explore whether GSTM1, GSTT1 and GSTP polymorphisms were associated with increased bladder cancer risk in an Egyptian population. GSTM1, GSTT1 and GSTP1 genotype frequencies were determined in bladder cancer cases (n=72) and healthy controls with no history of malignancies (n=82) using PCR-based techniques. The GSTT1*2 genotype was particularly associated with increased risk (OR 2.71, 95%CI 1.27-5.73) and the GSTM1*2 genotype to a lesser extent (OR 1.63, 95%CI 0.85-3.10). 18.1% of cases but only 7.3% of controls were GSTP1*B*B homozygotes (OR 2.38, 95%CI 0.83-6.87). The presence of two or more a priori at-risk genotypes was associated with increased bladder cancer risk (OR 2.42; 95%CI 1.47-3.97). These results suggest that polymorphisms in the GST genes are associated with increased risk of bladder cancer among Egyptians.     

Expression of Sara2 human gene in erythroid progenitors

A human homologue of Sar1, named Sara2, was shown to be preferentially expressed during erythropoiesis in a culture stimulated by EPO. Previous studies, in yeast, have shown that secretion-associated and Ras-related protein (Sar1p) plays an essential role in protein transport from the endoplasmic reticulum to the Golgi apparatus. Here, we report the molecular analysis of Sara2 in erythroid cell culture. A 1250 bp long cDNA, encoding a 198 amino-acid protein very similar to Sar1 proteins from other organisms, was obtained. Furthermore, we also report a functional study of Sara2 with Real-time quantitative PCR analysis, demonstrating that expression of Sara2 mRNA increases during the initial stages of erythroid differentiation with EPO and that a two-fold increase in expression occurs following the addition of hydroxyurea (HU). In K562 cells, Sara2 mRNA was observed to have a constant expression and the addition of HU also up-regulated the expression in these cells. Our results suggest that Sara2 is an important gene in processes involving proliferation and differentiation and could be valuable for understanding the vesicular transport system during erythropoiesis.     

Adsorption characteristics of malachite green on activated carbon derived from rice husks produced by chemical-thermal process

Phosphoric acid (H(3)PO(4)) and sodium hydroxide (NaOH) treated rice husks, followed by carbonization in a flowing nitrogen were used to study the adsorption of malachite green (MG) in aqueous solution. The effect of adsorption on contact time, concentration of MG and adsorbent dosage of the samples treated or carbonized at different temperatures were investigated. The results reveal that the optimum carbonization temperature is 500 degrees C in order to obtain adsorption capacity that is comparable to the commercial activated carbon for the husks treated by H(3)PO(4). It is interesting to note that MG adsorbed preferably on carbon-rich than on silica rich-sites. It is found that the behaviour of H(3)PO(4) treated absorbent followed both the Langmuir and Freundlich models while NaOH treated best fitted to only the Langmuir model.     

NopA is associated with cell surface appendages produced by the type III secretion system of Rhizobium sp. strain NGR234

Rhizobium sp. strain NGR234, which is capable of interacting with a large number of legumes, utilizes a variety of signaling molecules to establish nitrogen-fixing symbioses. Among these are nodulation outer proteins (Nops) that transit through a type III secretion system (TTSS). Abolition of Nop secretion affects nodulation of certain legumes. Under free-living conditions, the secretion of Nops can be induced by the addition of flavonoids. Here, we show that an in-frame deletion of nopA abolishes secretion of all other Nops and has the same impact on nodule formation as mutations that lead to a nonfunctional TTSS. This secretion-minus phenotype of the nopA mutant, as well as bioinformatics analysis of NopA itself, suggests that NopA could be an external component of the TTSS. Electron microscopy showed that NGR234 synthesizes fibrillar structures on the cell surface in a flavonoid-inducible and NopA-dependent manner. Purification of the macromolecular surface appendages revealed that NopA is a major component of these structures.     

Association analysis of the plasminogen activator inhibitor-1 4G/5G polymorphism in Hispanics and African Americans: the IRAS family study

OBJECTIVE: Plasminogen activator inhibitor type-1 (PAI-1) plays a central role in fibrolysis and has recently been hypothesized to influence components of the insulin resistance syndrome. We consider whether the 4G/5G polymorphism influences components of insulin resistance and obesity solely through PAI-1 protein levels or also though a secondary pathway. In addition, we explore whether transforming growth factor (TGF-beta1), a key regulator of PAI-1 expression, modifies the influence of the PAI-1 4G/5G polymorphism on these traits. METHODS AND RESULTS: The Insulin Resistance and Atherosclerosis (IRAS) Family Study genotyped 287 African American (18 pedigrees) and 811 Hispanic American (45 pedigrees) individuals for the 4G/5G PAI-1 and two TGF-beta1 polymorphisms (R25P, C-509T). Individuals were recruited from three clinical centers located in San Antonio (urban Hispanic), San Luis Valley (rural Hispanic) and Los Angeles (African American). The presence of the 4G PAI-1 allele was positively associated with PAI-1 protein level (combined sample p < 0.0001). Hispanic Americans average 65% higher PAI-1 protein levels than African Americans (p < 0.0001). Consistently across ethnic groups, increased PAI-1 protein levels were associated with increased insulin resistance and overall and central obesity (p value < 0.0001, combined sample). Adjusting for PAI-1 protein levels, there was evidence of an association of PAI-1 genotype (4G) with insulin sensitivity (p < 0.002) and subcutaneous fat (p < 0.01). These associations were not influenced by TGF-beta1 genotypes. CONCLUSIONS: PAI-1 protein is a strong correlate of insulin resistance (IR) and obesity in Hispanics and African Americans. However, PAI-1 4G/5G polymorphism appears to influence insulin resistance and obesity beyond its direct influence on serum PAI-1 protein levels.