32 research outputs found

    Evaluating the role of intestinal transporters in fruit juice-drug interactions

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    Fruit juice-drug interactions (FJDIs) involving non-metabolized oral medications result in decreased drug exposure that may lead to reduced therapeutic efficacy. The effect is thought to be mediated by inhibition of the intestinal drug transporters organic anion transporting polypeptide 1A2 and 2B1 (OATP1A2 and OATP2B1) by fruit juice constituents, however the exact mechanisms remain controversial. We tested the hypothesis that fruit juices limit the absorption of fexofenadine through interactions with specific intestinal transporters. In vitro transport and fruit juice inhibition studies using fexofenadine, a medication involved in FJDIs, revealed that in addition to previously implicated transporters, organic cation transporter 1 (OCT1) and organic solute transporter alpha/beta (OSTα/β) are potential novel targets of fruit juice components. Pharmacokinetic interaction studies in wild-type and mOatp2b1 knockout mice demonstrated that mOatp2b1 is not involved in fexofenadine absorption or FJDIs in vivo. These findings provide new insights into the mechanism of FJDIs

    The Genome of a Pathogenic Rhodococcus: Cooptive Virulence Underpinned by Key Gene Acquisitions

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    We report the genome of the facultative intracellular parasite Rhodococcus equi, the only animal pathogen within the biotechnologically important actinobacterial genus Rhodococcus. The 5.0-Mb R. equi 103S genome is significantly smaller than those of environmental rhodococci. This is due to genome expansion in nonpathogenic species, via a linear gain of paralogous genes and an accelerated genetic flux, rather than reductive evolution in R. equi. The 103S genome lacks the extensive catabolic and secondary metabolic complement of environmental rhodococci, and it displays unique adaptations for host colonization and competition in the short-chain fatty acid–rich intestine and manure of herbivores—two main R. equi reservoirs. Except for a few horizontally acquired (HGT) pathogenicity loci, including a cytoadhesive pilus determinant (rpl) and the virulence plasmid vap pathogenicity island (PAI) required for intramacrophage survival, most of the potential virulence-associated genes identified in R. equi are conserved in environmental rhodococci or have homologs in nonpathogenic Actinobacteria. This suggests a mechanism of virulence evolution based on the cooption of existing core actinobacterial traits, triggered by key host niche–adaptive HGT events. We tested this hypothesis by investigating R. equi virulence plasmid-chromosome crosstalk, by global transcription profiling and expression network analysis. Two chromosomal genes conserved in environmental rhodococci, encoding putative chorismate mutase and anthranilate synthase enzymes involved in aromatic amino acid biosynthesis, were strongly coregulated with vap PAI virulence genes and required for optimal proliferation in macrophages. The regulatory integration of chromosomal metabolic genes under the control of the HGT–acquired plasmid PAI is thus an important element in the cooptive virulence of R. equi

    Characterisation of tumor microvessel density during progression of high-grade serous ovarian cancer: clinico-pathological impact. An OCTIPS Consortium study.

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    Background: High-grade serous ovarian cancer (HGSOC) intratumoural vasculature evolution remains unknown. The study investigated changes in tumour microvessel density (MVD) in a large cohort of paired primary and recurrent HGSOC tissue samples and its impact on patients’ clinico-pathological outcome. Methods: A total of 222 primary (pOC) and recurrent (rOC) intra-patient paired HGSOC were assessed for immunohistochemical expression of angiogenesis-associated biomarkers (CD31, to evaluate MVD, and VEGF-A). Expression profiles were compared between pOCs and rOCs and correlated with patients' data. Results: High intratumoural MVD and VEGF-A expression were observed in 75.7% (84/111) and 20.7% (23/111) pOCs, respectively. MVDhighand VEGF(+)samples were detected in 51.4% (57/111) and 20.7% (23/111) rOCs, respectively. MVDhigh/VEGF(+)co-expression was found in 19.8% (22/111) and 8.1% (9/111) of pOCs and rOCs, respectively (p = 0.02). Pairwise analysis showed no significant change in MVD (p = 0.935) and VEGF-A (p = 0.121) levels from pOCs to rOCs. MVDhighpOCs were associated with higher CD3(+)(p = 0.029) and CD8(+)(p = 0.013) intratumoural effector TILs, while VEGF(+)samples were most frequently encountered among BRCA-mutated tumours (p = 0.019). Multivariate analysis showed VEGF and MVD were not independent prognostic factors for OS. Conclusions: HGSOC intratumoural vasculature did not undergo significant changes during disease progression. High concentration of CD31(+)vessels seems to promote recruitment of effector TILs. The study also provides preliminary evidence of the correlation between VEGF-positivity and BRCA status

    Analysis of Plasmodium falciparum diversity in natural infections by deep sequencing.

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    Malaria elimination strategies require surveillance of the parasite population for genetic changes that demand a public health response, such as new forms of drug resistance. Here we describe methods for the large-scale analysis of genetic variation in Plasmodium falciparum by deep sequencing of parasite DNA obtained from the blood of patients with malaria, either directly or after short-term culture. Analysis of 86,158 exonic single nucleotide polymorphisms that passed genotyping quality control in 227 samples from Africa, Asia and Oceania provides genome-wide estimates of allele frequency distribution, population structure and linkage disequilibrium. By comparing the genetic diversity of individual infections with that of the local parasite population, we derive a metric of within-host diversity that is related to the level of inbreeding in the population. An open-access web application has been established for the exploration of regional differences in allele frequency and of highly differentiated loci in the P. falciparum genome

    Human milk intake in preterm infants and neurodevelopment at 18 months corrected age

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    BackgroundThe effect of human milk intake on neurodevelopment in preterm infants is uncertain.MethodsWe analyzed data from 611 participants in the DHA for Improvement of Neurodevelopmental Outcomes study, enrolled at ≤33 wk gestation from five Australian perinatal centers. The main exposures were (i) average daily human milk intake during the neonatal hospitalization and (ii) total duration of human milk intake before and after discharge. Outcomes were Bayley Scales of Infant Development, 2nd Edition Mental (MDI), and Psychomotor (PDI) Development Indexes.ResultsAdjusting for confounders in linear regression, human milk intake was not associated with higher MDI (0.2 points per 25 ml/kg/d; 95% confidence interval (CI): -0.6, 1.0) or PDI (-0.3 points; 95% CI: -1.1, 0.4). Longer duration of human milk intake was also not associated with MDI (0.1 points per month; 95% CI: -0.2, 0.3) or PDI (-0.2 points per month; 95% CI: -0.5, 0.01) scores, except in infants born 29-33 wk gestation (n = 364, MDI 0.3 points higher per additional month, 95% CI: 0.1, 0.6).ConclusionsWe found no associations of human milk intake during the neonatal hospitalization with neurodevelopment at 18 mo corrected age.Background: The effect of human milk intake on neurodevelopment in preterm infants is uncertain. Methods: We analyzed data from 611 participants in the DHA for Improvement of Neurodevelopmental Outcomes study, enrolled at ≤33 wk gestation from five Australian perinatal centers. The main exposures were (i) average daily human milk intake during the neonatal hospitalization and (ii) total duration of human milk intake before and after discharge. Outcomes were Bayley Scales of Infant Development, 2nd Edition Mental (MDI), and Psychomotor (PDI) Development Indexes. Results: Adjusting for confounders in linear regression, human milk intake was not associated with higher MDI (0.2 points per 25 ml/kg/d; 95% confidence interval (CI): −0.6, 1.0) or PDI (−0.3 points; 95% CI: −1.1, 0.4). Longer duration of human milk intake was also not associated with MDI (0.1 points per month; 95% CI: −0.2, 0.3) or PDI (−0.2 points per month; 95% CI: −0.5, 0.01) scores, except in infants born 29–33 wk gestation (n = 364, MDI 0.3 points higher per additional month, 95% CI: 0.1, 0.6). Conclusions: We found no associations of human milk intake during the neonatal hospitalization with neurodevelopment at 18 mo corrected age
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