Differences of Pathophysiology in Experimental Meningitis Caused by Three Strains of Streptococcus Pneumoniae

Differences in cytochemical and pathophysiologic abnormalities in experimental meningitis caused by pneumococcal strains A, B, and C were determined. Strain C produced the most severe abnormalities of cerebrospinal fluid (CSF) concentrations of lactate (P < .01), protein (P < .02), and glucose (P < .01), CSF white blood cell count (P < .04), cerebral blood flow (P < .02), and clinical signs (P < .05). Brain edema occurred only with strains A and C, with no association with disease severity; intracranial hypertension was also independent of disease severity. Strain B, not C, achieved the highest bacterial titers in the CSF (P < .005). The widely different abilities of strains of Streptococcus pneumoniae to induce intracranial abnormalities suggest that virulence determinants affect not only evasion of defense during colonization and invasion, as shown in other models, but also determine the course of disease once infection has been established. Differences of cell-wall metabolism among pneumococcal strains may playa role in this latter phase of the development of meningiti

Metabolic switches and adaptations deduced from the proteomes of Streptomyces coelicolor wild type and phoP mutant grown in batch culture

[EN] Bacteria in the genus Streptomyces are soil-dwelling oligotrophs and important producers of secondary metabolites. Previously, we showed that global messenger RNA expression was subject to a series of metabolic and regulatory switches during the lifetime of a fermentor batch culture of Streptomyces coelicolor M145. Here we analyze the proteome from eight time points from the same fermentor culture and, because phosphate availability is an important regulator of secondary metabolite production, compare this to the proteome of a similar time course from an S. coelicolor mutant, INB201 (ΔphoP), defective in the control of phosphate utilization. The proteomes provide a detailed view of enzymes involved in central carbon and nitrogen metabolism. Trends in protein expression over the time courses were deduced from a protein abundance index, which also revealed the importance of stress pathway proteins in both cultures. As expected, the ΔphoP mutant was deficient in expression of PhoP-dependent genes, and several putatively compensatory metabolic and regulatory pathways for phosphate scavenging were detected. Notably there is a succession of switches that coordinately induce the production of enzymes for five different secondary metabolite biosynthesis pathways over the course of the batch culturesSIThis work was funded by Biotechnology and Biological Sciences Research Council Grant BB/F003439/1, ERA-NET SysMO Project GEN2006-27745-E/SYS Grant P-UK-01-11-3i, and Research Council of Norway Project 181840/I30. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact

Efficacy and safety of glecaprevir/pibrentasvir in treatment-naïve adults with chronic hepatitis C virus genotypes 1–6 in Brazil

Introduction and objectives: Glecaprevir/pibrentasvir is a highly effective and well tolerated treatment for hepatitis C infection. Brazilian patients were not included in the original development studies for glecaprevir/pibrentasvir. This study aimed to assess safety and efficacy of glecaprevir/pibrentasvir in treatment-naïve Brazilian adults without cirrhosis or with compensated cirrhosis. Patients and methods: EXPEDITION-3 was a Phase 3, open-label, multicenter study in treatment-naïve Brazilian adults with hepatitis C infection genotype 1–6. Patients without cirrhosis (F2 or F3) or with compensated cirrhosis (F4) received 8 or 12 weeks of glecaprevir/pibrentasvir, respectively. The primary efficacy endpoint was the rate of sustained virologic response at post-treatment Week 12. Secondary endpoints were on-treatment virologic failure and relapse rates. Baseline polymorphisms were assessed in NS3 and NS5A. Adverse events and laboratory abnormalities were monitored. Results: 100 patients were enrolled, 75 received 8 weeks of treatment and 25 received 12 weeks; all patients completed treatment. Overall sustained virologic response at post-treatment Week 12 rate was high (98.0%; 98/100; 95% confidence interval: 93.0–99.4) and remained high regardless of baseline viral or host factors, including demographics, hepatitis C virus RNA levels, polymorphisms in NS3 and/or NS5A, genotype, and relevant comorbidities. 55% of patients reported ≥1 adverse event, the most common beingheadache (18.0%). Four patients reported serious adverse events; none were considered drug related orled to study drug discontinuation. No hepatic decompensations were observed.Conclusions: Glecaprevir/pibrentasvir was effective and well tolerated in treatment-naïve Brazilianpatients with hepatitis C infection without cirrhosis and with compensated cirrhosis

The dynamic architecture of the metabolic switch in Streptomyces coelicolor

[EN] Background: During the lifetime of a fermenter culture, the soil bacterium S. coelicolor undergoes a major metabolic switch from exponential growth to antibiotic production. We have studied gene expression patterns during this switch, using a specifically designed Affymetrix genechip and a high-resolution time-series of fermenter-grown samples.Results: Surprisingly, we find that the metabolic switch actually consists of multiple finely orchestrated switching events. Strongly coherent clusters of genes show drastic changes in gene expression already many hours before the classically defined transition phase where the switch from primary to secondary metabolism was expected. The main switch in gene expression takes only 2 hours, and changes in antibiotic biosynthesis genes are delayed relative to the metabolic rearrangements. Furthermore, global variation in morphogenesis genes indicates an involvement of cell differentiation pathways in the decision phase leading up to the commitment to antibiotic biosynthesis.Conclusions: Our study provides the first detailed insights into the complex sequence of early regulatory events during and preceding the major metabolic switch in S. coelicolor, which will form the starting point for future attempts at engineering antibiotic production in a biotechnological settingSIWe are very grateful to Mervyn Bibb for his generous support with the Affymetrix custom microarray design. We acknowledge the excellent technical help of K. Klein, S. Poths, M. Walter, A. Øverby and E. Hansen. This project was supported by grants of the ERA-NET SySMO Project [GEN2006-27745-E/SYS]: (P-UK-01-11-3i) and the Research Council of Norway [project no. 181840/I30

y Integrated analysis of 8-week glecaprevir/pibrentasvir in Japanese and overseas patients without cirrhosis and with hepatitis C virus genotype 1 or 2 infection

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The Constrained Maximal Expression Level Owing to Haploidy Shapes Gene Content on the Mammalian X Chromosome.

X chromosomes are unusual in many regards, not least of which is their nonrandom gene content. The causes of this bias are commonly discussed in the context of sexual antagonism and the avoidance of activity in the male germline. Here, we examine the notion that, at least in some taxa, functionally biased gene content may more profoundly be shaped by limits imposed on gene expression owing to haploid expression of the X chromosome. Notably, if the X, as in primates, is transcribed at rates comparable to the ancestral rate (per promoter) prior to the X chromosome formation, then the X is not a tolerable environment for genes with very high maximal net levels of expression, owing to transcriptional traffic jams. We test this hypothesis using The Encyclopedia of DNA Elements (ENCODE) and data from the Functional Annotation of the Mammalian Genome (FANTOM5) project. As predicted, the maximal expression of human X-linked genes is much lower than that of genes on autosomes: on average, maximal expression is three times lower on the X chromosome than on autosomes. Similarly, autosome-to-X retroposition events are associated with lower maximal expression of retrogenes on the X than seen for X-to-autosome retrogenes on autosomes. Also as expected, X-linked genes have a lesser degree of increase in gene expression than autosomal ones (compared to the human/Chimpanzee common ancestor) if highly expressed, but not if lowly expressed. The traffic jam model also explains the known lower breadth of expression for genes on the X (and the Z of birds), as genes with broad expression are, on average, those with high maximal expression. As then further predicted, highly expressed tissue-specific genes are also rare on the X and broadly expressed genes on the X tend to be lowly expressed, both indicating that the trend is shaped by the maximal expression level not the breadth of expression per se. Importantly, a limit to the maximal expression level explains biased tissue of expression profiles of X-linked genes. Tissues whose tissue-specific genes are very highly expressed (e.g., secretory tissues, tissues abundant in structural proteins) are also tissues in which gene expression is relatively rare on the X chromosome. These trends cannot be fully accounted for in terms of alternative models of biased expression. In conclusion, the notion that it is hard for genes on the Therian X to be highly expressed, owing to transcriptional traffic jams, provides a simple yet robustly supported rationale of many peculiar features of X's gene content, gene expression, and evolution

United States: Harriet Tubman

This item is part of the Chicago Anti-Apartheid Movement collection at the College Archives & Special Collections department of Columbia College Chicago. Contact [email protected] for more information and to view the collection.https://digitalcommons.colum.edu/cadc_caam_posters/1056/thumbnail.jp