Microbial inactivation using plasma-activated water obtained by gliding electric discharges

Aim:  To evaluate the microbial disinfection efficacy of a plasmachemical solution obtained by the activation of water with gliding electric discharges.
Methods and Results:  Distilled water was activated for 5 min by a nonthermal quenched plasma of the glidarc type operating in humid air and at atmospheric pressure. The plasma-activated water (PAW) was then used to treat planktonic and adherent cells of Staphylococcus epidermidis , Leuconostoc mesenteroides (as models of Gram-positive bacteria), Hafnia alvei (a Gram-negative bacteria) and Saccharomyces cerevisiae (as a yeast model). The treatments were less efficient on adherent cells than on planktonic cells in the case of bacteria, but not of S. cerevisiae . Inactivation was more effective for bacteria than for the yeast.
Conclusions:  Significant reductions in microbial populations were achieved in all cases, demonstrating the effectiveness of this new approach to treat contaminated media.
Significance and Impact of the Study:  PAW is a promising solution with potential application to the decontamination of equipment and surfaces.     

Retama species growing in different ecological–climatic areas of northeastern Algeria have a narrow range of rhizobia that form a novel phylogenetic clade within the Bradyrhizobium genus

Sixty-seven isolates were isolated from nodules collected on roots of Mediterranean shrubby legumes Retama raetam and Retama sphaerocarpa growing in seven ecological–climatic areas of northeastern Algeria. Genetic diversity of the Retama isolates was analyzed based on genotyping by restriction fragment length polymorphism of PCR-amplified fragments of the 16S rRNA gene, the intergenic spacer (IGS) region between the 16S and 23S rRNA genes (IGS), and the symbiotic genes nifH and nodC. Eleven haplotypes assigned to the Bradyrhizobium genus were identified. Significant biogeographical differentiation of the rhizobial populations was found, but one haplotype was predominant and conserved across the sites. All isolates were able to cross-nodulate the two Retama species. Accordingly, no significant genetic differentiation of the rhizobial populations was found in relation to the host species of origin. Sequence analysis of the 16S rRNA gene grouped the isolates with Bradyrhizobium elkanii, but sequence analyses of IGS, the housekeeping genes (dnaK, glnII, recA), nifH, and nodC yielded convergent results showing that the Retama nodule isolates from the northeast of Algeria formed a single evolutionary lineage, which was well differentiated from the currently named species or well-delineated unnamed genospecies of bradyrhizobia. Therefore, this study showed that the Retama species native to northeastern Algeria were associated with a specific clade of bradyrhizobia. The Retama isolates formed three sub-groups based on IGS and housekeeping gene phylogenies, which might form three sister species within a novel bradyrhizobial clade.     

Influence de la rhTSH sur la fixation du 18 FDG dans une population de 42 patients avec cancer différencié de la thyroïde suspect de récidive

PurposeThe role of positron emission tomography with 18 fluoro-deoxy-glucose (FDG-PET) in case of differentiated thyroid carcinoma recurrence is established. However, the influence of TSH levels on 18 FDG is still discussed. Our study aims at comparing respective performances of FDG-PET performed at low TSH levels and under rhTSH stimulation, when a recurrence of a thyroid carcinoma is suspected.Material and methodsForty-two patients have been included, in a prospective way; each of them has been explored by FDG-PET at low (PET1) and high TSH levels with Thyrogen^® (PET2). The number of hypermetabolic foci, the intensity of uptake, both visual and with Standardized Uptake Values (SUV) have been compared.ResultsPET1: 82 foci were detected, including 75 true positive (TP) and seven false positive (FP). Sensitivity by lesion is 85.23 and 58.6% on a patient basis. Twelve pathological sites, not visualized (false negative) in PET1, were seen under stimulation. PET2: 89 foci were detected, including 87 TP and two FP; two tumoral sites visualized with PET1 are not detected. Sensitivity by lesion is 97.75 and 75.9% on a patient basis. SUV are significantly higher under stimulation. In three patients, therapeutic strategy has been modified, based on PET2 data.ConclusionStimulation by rhTSH improves FDG-PET performances. Therefore, it is justified to resort to it in case of recurrence of differentiated thyroid carcinoma, when the usual workup is negative.     

CK2 activity is modulated by growth rate in Saccharomyces cerevisiae

CK2 is a highly conserved protein kinase controlling different cellular processes. It shows a higher activity in proliferating mammalian cells, in various types of cancer cell lines and tumors. The findings presented herein provide the first evidence of an in vivo modulation of CK2 activity, dependent on growth rate, in Saccharomyces cerevisiae. In fact, CK2 activity, assayed on nuclear extracts, is shown to increase in exponential growing batch cultures at faster growth rate, while localization of catalytic and regulatory subunits is not nutritionally modulated. Differences in intracellular CK2 activity of glucose- and ethanol-grown cells appear to depend on both increase in molecule number and k_cat. Also in chemostat cultures nuclear CK2 activity is higher in faster growing cells providing the first unequivocal demonstration that growth rate itself can affect CK2 activity in a eukaryotic organism.     

A Single Amino Acid Change in the Hemagglutinin Protein of Measles Virus Determines Its Ability To Bind CD46 and Reveals Another Receptor on Marmoset B Cells

This paper provides evidence for a measles virus receptor other than CD46 on transformed marmoset and human B cells. We first showed that most tissues of marmosets are missing the SCR1 domain of CD46, which is essential for the binding of Edmonston measles virus, a laboratory strain that has been propagated in Vero monkey kidney cells. In spite of this deletion, the common marmoset was shown to be susceptible to infections by wild-type isolates of measles virus, although they did not support Edmonston measles virus production. As one would expect from these results, measles virus could not be propagated in owl monkey or marmoset kidney cell lines, but surprisingly, both a wild-type isolate (Montefiore 89) and the Edmonston laboratory strain of measles virus grew efficiently in B95-8 marmoset B cells. In addition, antibodies directed against CD46 had no effect on wild-type infections of marmoset B cells and only partially inhibited the replication of the Edmonston laboratory strain in the same cells. A direct binding assay with insect cells expressing the hemagglutinin (H) proteins of either the Edmonston or Montefiore 89 measles virus strains was used to probe the receptors on these B cells. Insect cells expressing Edmonston H but not the wild-type H bound to rodent cells with CD46 on their surface. On the other hand, both the Montefiore 89 H and Edmonston H proteins adhered to marmoset and human B cells. Most wild-type H proteins have asparagine residues at position 481 and can be converted to a CD46-binding phenotype by replacement of the residue with tyrosine. Similarly, the Edmonston H protein did not bind CD46 when its Tyr481 was converted to asparagine. However, this mutation did not affect the ability of Edmonston H to bind marmoset and human B cells. The preceding results provide evidence, through the use of a direct binding assay, that a second receptor for measles virus is present on primate B cells.     

Studies on stomatal function, epicuticular wax and stem-root transition region of polyethylene glycol-treated and nontreatedin vitro grape plantlets

Summary Scanning electron microscopy, light microscopy, and gravimetric analysis was used to evaluate stomatal function, epicuticular wax, and the stem-root transition region of grape (Vitis sp. ‘Valiant’) plantlets grownin vitro, polyethylene glycoltreatedin vitro, and greenhouse-grown plants. Scanning electron microscopic studies of leaf surfaces ofin vitro-grown plants showed widely open stomata as compared to leaf stomata of polyethylene glycol-treatedin vitro-cultured and greenhouse-grown plants. Ultrastructurally, leaf epicuticular wax ofin vitro plants was less dense than in their polyethylene-treated and greenhouse counterparts. Quantitatively,in vitro-grown plants had reduced epicuticular was as compared to polyethylene glycol-treated and greenhouse-grown plants. Light microscopic studies showed no obvious differences in the vascular connections in the stem-root transition region ofin vitro-cultured, polyethylene glycol-treatedin vitro-cultured, and greenhouse-grown plants. It is therefore likely that the rapid wilting and desiccation observed after transplantingin vitro grape plantlets is due to their defective stomatal function and reduced epicuticular wax and may not be due to poor water transport associated with vascular connection.     

Molecular genetic investigations of the mechanism of tumourigenesis in von Hippel-Lindau disease: analysis of allele loss in VHL tumours

Von Hippel-Lindau (VHL) disease is a dominantly inherited familial cancer syndrome characterised by the development of retinal and central nervous system haemangioblastomas, renal cell carcinoma (RCC), phaeochromocytoma and pancreatic tumours. The VHL disease gene maps to chromosome 3p25-p26. To investigate the mechanism of tumourigenesis in VHL disease, we analysed 24 paired blood/tumour DNA samples from 20 VHL patients for allele loss on chromosome 3p and in the region of tumour suppressor genes on chromosomes 5, 11, 13, 17 and 22. Nine out of 24 tumours showed loss of heterozygosity (LOH) at at least one locus on chromosome 3p and in each case the LOH included the region to which the VHL gene has been mapped. Chromosome 3p allele loss was found in four tumour types (RCC, haemangioblastoma, phaeochromocytoma and pancreatic tumour) suggesting a common mechanism of tumourigenesis in all types of tumour in VHL disease. The smallest region of overlap was between D3S1038 and D3S18, a region that corresponds to the target region for the VHL gene from genetic linkage studies. The parental origin of the chromosome 3p25-p26 allele loss could be determined in seven tumours from seven familial cases; in each tumour, the allele lost had been inherited from the unaffected parent. Our results suggest that the VHL disease gene functions as a recessive tumour suppressor gene and that inactivation of both alleles of the VHL gene is the critical event in the pathogenesis of VHL neoplasms. Four VHL tumours showed LOH on other chromosomes (5q21, 13q, 17q) indicating that homozygous VHL gene mutations may be required but may not be sufficient for tumourigenesis in VHL disease.     

Von Hippel-Lindau disease: identification of deletion mutations by pulsed-field gel electrophoresis

Von Hippel-Lindau disease (VHL) is an inherited multisystem neoplastic disorder. We prepared a 2.5-megabase (Mb) restriction map of the region surrounding the VHL gene and identified and characterized overlapping deletions in three unrelated patients affected with VHL. The smallest nested deletion (100 kb) was located within a 510-kb NruI fragment detected by 19–63. The rearrangements detected will be useful in isolating and evaluating candidate cDNAs for the VHL gene. The detailed physical map will be useful in studying the organization and structure of genes in the VHL region.