Genomic comparison of two strains of Mycobacterium avium subsp. paratuberculosis with contrasting pathogenic phenotype.

In a previous study, we evaluated the degree of virulence of Mycobacterium avium subsp. paratuberculosis (Map) strains isolated from cattle in Argentina in a murine model. This assay allowed us to differentiate between high-virulent MapARG1347 and low-virulent MapARG1543 strains. To corroborate whether the differences in virulence could be attributed to genetic differences between the strains, we performed Whole Genome Sequencing and compared the genomes and gene content between them and determined the differences related to the reference strain MapK10. We found 233 SNPs/INDELS in one or both strains relative to Map K10. The two strains share most of the variations, but we found 15 mutations present in only one of the strains. Considering NS-SNP/INDELS that produced a severe effect in the coding sequence, we focus the analysis on four predicted proteins, putatively related to virulence. Survival of MapARG1347 strain in bMDM was higher than MapARG1543 and was more resistant to acidic pH and H2O2 stresses than MapK10. The genomic differences between the two strains found in genes MAP1203 (a putative peptidoglycan hydrolase), MAP0403 (a putative serine protease) MAP1003c (a member of the PE-PPE family) and MAP4152 (a putative mycofactocin binding protein) could contribute to explain the contrasting phenotype previously observed in mice models.

Genetic variability and demographic history of Heliothis virescens (Lepidoptera: Noctuidae) populations from Brazil inferred by mtDNA sequences.

Intra- and inter-population genetic variability and the demographic history of Heliothis virescens (F.) populations were evaluated by using mtDNA markers (coxI, coxII and nad6) with samples from the major cotton- and soybean-producing regions in Brazil in the growing seasons 2007/08, 2008/09 and 2009/10. AMOVA indicated low and non-significant genetic structure, regardless of geographical scale, growing season or crop, with most of genetic variation occurring within populations. Clustering analyzes also indicated low genetic differentiation. The haplotype network obtained with combined datasets resulted in 35 haplotypes, with 28 exclusive occurrences, four of them sampled only from soybean fields. The minimum spanning network showed star-shaped structures typical of populations that underwent a recent demographic expansion. The recent expansion was supported by other demographic analyzes, such as the Bayesian skyline plot, the unimodal distribution of paired differences among mitochondrial sequences, and negative and significant values of neutrality tests for the Tajima's D and Fu's F(S) parameters. In addition, high values of haplotype diversity (H) and low values of nucleotide diversity (π), combined with a high number of low frequency haplotypes and values of θ(π)<θ(W), suggested a recent demographic expansion of H. virescens populations in Brazil. This demographic event could be responsible for the low genetic structure currently found; however, haplotypes present uniquely at the same geographic regions and from one specific host plant suggest an initial differentiation among H. virescens populations within Brazil.

Effect of desmethyldiazepam and chlordesmethyldiazepam on 3',5'-cyclic guanosine monophosphate levels in rat cerebellum.

Three different ben,odia,epines (diazepam, its pharmacologically active metabolite desmethyldiazepam, and the derivative chlordesmethyldiazepam) have been compared in our study for their effects on 3',5'-guanosine monophosphate (cGMP) cerebellar levels. Desmethyldiazepam and chlordesmethyldiazepam are several-fold more potent than diazepam in decreasing rat cyclic cGMP cerebellar concentrations. None of the three drugs induces detectable changes of cerebellar cyclic 3',5'-adenosine monophosphate (cAMP). On the other hand, the three compounds did not modify the levels of cGMP in cerebellum of newborn rats, where Purkinje cell and dendrites lack synaptic contacts. However, injection of gamma aminobutyric acid (GABA) in the newborn is still able, as in the adult, to decrease cGMP concentration in cerebellum. Our data support the hypothesis that cGMP cerebellar concentrations may be reliable biochemical marker of the clinical activity of benzodiazepines.

Effects of sulpiride isomers on the control of anterior pituitary secretion in normal man.

The effects of (+)- and (-)-sulpiride on anterior pituitary hormone secretion (LH, FSH, PL, hGH, TSH) have been studied in five normal men. Both (+)- and (-)-sulpiride increase PL and TSH secretion and decrease LH and FSH secretion, whereas they do not seem to affect hGH secretion. These results are discussed in view of the different action of (+)- and (-)-sulpiride on DA receptors in the forebrain with respect to DA receptors involved in the control of anterior pituitary secretion.

Plasma levels of chlorodesmethyldiazepam in humans.

Chlorodesmethyldiazepam (I) concentrations were followed for 72 h in the plasma of four volunteers given 2 mg of the drug orally. The drug appears to be well absorbed, reaching peak plasma levels of 20--30 ng ml-1 1--2 h after administration; 72 h after administration, plasma concentrations are still measurable (5 ng ml-1). The analytical method involved a single extraction of I from the plasma into benzene followed by centrifugation, evaporation, and gas-chromatographic analysis of the samples.