Antimicrob Agents Chemother
February 2015
Drug-resistant tuberculosis (TB) has lent urgency to finding new drug leads with novel modes of action. A high-throughput screening campaign of >65,000 actinomycete extracts for inhibition of Mycobacterium tuberculosis viability identified ecumicin, a macrocyclic tridecapeptide that exerts potent, selective bactericidal activity against M. tuberculosis in vitro, including nonreplicating cells.
View Article and Find Full Text PDFThe new tuberculosis (TB) lead ecumicin (1), a cyclic tridecapeptide, was isolated from Nonomuraea sp. MJM5123, following a high-throughput campaign for anti-TB activity. The large molecular weight of 1599 amu detected by LC-HR-MS precluded the initial inference of its molecular formula.
View Article and Find Full Text PDFProanthocyanidins (PACs) are secondary plant metabolites that mediate nonenzymatic collagen cross-linking and enhance the properties of collagen based tissue, such as dentin. The extent and nature of cross-linking is influenced by the composition and specific chemical structure of the bioactive compounds present in certain PAC-rich extracts. This study investigated the effect of the molecular weight and stereochemistry of polyphenol compounds on two important properties of dentin, biomechanics, and biostability.
View Article and Find Full Text PDFObjective: To examine the availability, need, and use of workplace policies for workers with osteoarthritis (OA) and inflammatory arthritis (IA) and their association with employment outcomes.
Methods: Participants (n = 219) were employed, ages ≥25 years, and diagnosed with OA or IA. They were recruited through community advertising and rheumatology clinics in 2 Canadian provinces.
Background: There is increasing recognition that quality of life (QoL) and patient-reported outcomes (PROs) are of fundamental importance and particularly relevant given the relatively high likelihood of long-term survival in most women with endometrial cancer (EC). However, there has been relatively little research focused on this topic. Our objective was to analyze our current knowledge and identify research questions to be included in the design of next clinical trials.
View Article and Find Full Text PDFBackground: Quality of life (QoL) in endometrial cancer (EC) is understudied. Incorporation of QoL questionnaires and patient-reported outcomes in clinical trials has been inconsistent, and the tools and interpretation of these measures are unfamiliar to most practitioners. In 2012, the Gynecologic Cancer InterGroup Symptom Benefit Working Group convened for a brainstorming collaborative session to address deficiencies and work toward improving the quality and quantity of QoL research in women with EC.
View Article and Find Full Text PDFJ Obstet Gynaecol Can
August 2014
Objective: Ovarian cancer treatments and outcomes vary substantially, yielding a diverse group of survivors. Few data exist on quality of life (QoL) concerns and the foremost needs of these patients. Our goal was to conduct a pilot study to determine the QoL needs of ovarian cancer survivors to establish priorities for future interventions.
View Article and Find Full Text PDFInt J Gynecol Cancer
October 2014
Objective: The aim of this study was to determine whether pelvic inflammation contributes to the pathogenesis of ovarian cancer or other malignancies.
Design: This article is a cohort study.
Setting: The study was conducted in a tertiary university and provincial cancer referral institutions.
Background: Many advanced human tumors, including hepatocellular carcinomas (HCC) are auxotrophic for arginine due to down-regulation of argininosuccinate synthetase (ASS1), the rate-limiting enzyme in arginine synthesis. The arginine-lowering agent PEGylated arginine deiminase (ADI-PEG 20) has shown efficacy as a monotherapy in clinical trials for treating arginine-auxotrophic tumors and is currently being evaluated in combination with cisplatin in other cancer types. Epigenetic silencing via methylation of the ASS1 promoter has been previously demonstrated in other cancer types, and a reciprocal relationship between ASS1 expression and cisplatin resistance has also been observed in ovarian cancer.
View Article and Find Full Text PDFThe evolution of cancer genomes within a single tumor creates mixed cell populations with divergent somatic mutational landscapes. Inference of tumor subpopulations has been disproportionately focused on the assessment of somatic point mutations, whereas computational methods targeting evolutionary dynamics of copy number alterations (CNA) and loss of heterozygosity (LOH) in whole-genome sequencing data remain underdeveloped. We present a novel probabilistic model, TITAN, to infer CNA and LOH events while accounting for mixtures of cell populations, thereby estimating the proportion of cells harboring each event.
View Article and Find Full Text PDFPreviously reported findings in Austrian BRCA1/2 mutation carriers suggested a possible dependency of embryos with BRCA1/2 mutations on so-called low alleles of the fragile X mental retardation 1 (FMR1) gene, characterized by less than 26 CGG repeats (CGG(n<26)). The hypothesis arose from a study reporting highly statistically significant enrichment of low FMR1 alleles, significantly exceeding low allele prevalence in a general population, suggesting embryo lethality of BRCA1/2 mutations, "rescued" by presence of low FMR1 alleles. Such a dependency would also offer an explanation for the so-called "BRCA-paradox," characterized by BRCA1/2 deficient embryonic tissues being anti-proliferative (thereby potentially causing embryo-lethality) but proliferative in malignant tumors, including breast and ovarian cancers.
View Article and Find Full Text PDFThe pathogenesis of vulvar squamous cell carcinoma follows 1 of 2 distinct pathways. A precursor lesion in the human papilloma virus-independent pathway, differentiated vulvar intraepithelial neoplasia (dVIN), was only recently characterized in detail and is infrequently diagnosed without an associated component of invasive carcinoma. Aberrant p53 immunostaining is frequently seen in dVIN, and in approximately 25% to 30% of cases it manifests as a complete loss or a p53-null pattern.
View Article and Find Full Text PDFThe present study demonstrates the importance of adequate precision when reporting the δ and J parameters of frequency domain (1)H NMR (HNMR) data. Using a variety of structural classes (terpenoids, phenolics, alkaloids) from different taxa (plants, cyanobacteria), this study develops rationales that explain the importance of enhanced precision in NMR spectroscopic analysis and rationalizes the need for reporting Δδ and ΔJ values at the 0.1-1 ppb and 10 mHz level, respectively.
View Article and Find Full Text PDFHuman biological specimens are important for translational research programs such as the Canadian Ovarian Experimental Unified Resource (COEUR) funded by the Terry Fox Research Institute. Sample quality is an important consideration, as it directly impacts the quality of ensuing research. The aim of the present study was to determine the quality of tissues collected from different sites contributing to the COEUR cohort.
View Article and Find Full Text PDFProanthocyanidin-rich plant-derived agents have been shown to enhance dentin biomechanical properties and resistance to collagenase degradation. This study systematically investigated the interaction of chemically well-defined monomeric catechins with dentin extracellular matrix components by evaluating dentin mechanical properties as well as activities of matrix metalloproteinases (MMPs) and cysteine-cathepsins (CTs). Demineralized dentin beams (n=15) were incubated for 1h with 0.
View Article and Find Full Text PDFThe interpretation of NMR spectroscopic information for structure elucidation involves decoding of complex resonance patterns that contain valuable molecular information (δ and J), which is not readily accessible otherwise. We introduce a new concept of 2D-NMR barcoding that uses clusters of fingerprint signals and their spatial relationships in the δ-δ coordinate space to facilitate the chemical identification of complex mixtures. Similar to widely used general barcoding technology, the structural information of individual compounds is encoded as a specifics pattern of their C,H correlation signals.
View Article and Find Full Text PDFAlthough proanthocyanidins (PACs) modify dentin, the effectiveness of different PAC sources and the correlation with their specific chemical composition are still unknown. This study describes the chemical profiling of natural PAC-rich extracts from 7 plants using ultra high pressure/performance liquid chromatography (UHPLC) to determine the overall composition of these extracts and, in parallel, comprehensively evaluate their effect on dentin properties. The total polyphenol content of the extracts was determined (as gallic acid equivalents) using Folin-Ciocalteau assays.
View Article and Find Full Text PDFResearch published over the past 10 years has suggested that most "ovarian cancer," and specifically the high-grade serous carcinoma (HGSC) subtype of ovarian cancer, actually originates in the fallopian tube. In this review, we examine the evidence supporting the tubal origin hypothesis for HGSC, and discuss the clinical implications of our improved understanding of the pathogenesis of ovarian cancer. We searched Medline R and Medline in-process and non-indexed citations from inception to December 15, 2012, to identify all English or French language articles discussing the origins of HGSC.
View Article and Find Full Text PDFNuclear Magnetic Resonance (NMR) is a universal and quantitative analytical technique. Being a unique structural tool, NMR also competes with metrological techniques for purity determination and reference material analysis. In pharmaceutical research, applications of quantitative NMR (qNMR) cover mostly the identification and quantification of drug and biological metabolites.
View Article and Find Full Text PDFA new strategy for the analysis of natural products uses a combination of quantitative (1)H NMR (qHNMR) and adsorbent-free countercurrent separation (CS) methodology to establish a quantification method for ginkgotoxin (4'-O-methylpyridoxine) in Ginkgo biloba preparations. The target analyte was concentrated in a one-step CS process using the ChMWat +2 solvent system (CHCl3-MeOH-H2O, 10:5:5) and subsequently assayed by qHNMR. While commercial G.
View Article and Find Full Text PDFObjective: The purpose of this study was to assess the uptake and perioperative safety of bilateral salpingectomy (BS) as an ovarian cancer risk-reduction strategy in low-risk women after a regional initiative that was aimed at general gynecologists in the province of British Columbia, Canada.
Study Design: This population-based retrospective cohort study evaluated 43,931 women in British Columbia from 2008-2011 who underwent hysterectomy that was performed with and without BS or bilateral salpingo-oophorectomy or who underwent surgical sterilization by means of BS or tubal ligation. Parameters that were examined include patient age, operating time, surgical approach, indication, length of hospital stay, and perioperative complications.
Objectives: The biomodification of dentin is a biomimetic approach, mediated by bioactive agents, to enhance and reinforce the dentin by locally altering the biochemistry and biomechanical properties. This review provides an overview of key dentin matrix components, targeting effects of biomodification strategies, the chemistry of renewable natural sources, and current research on their potential clinical applications.
Methods: The PubMed database and collected literature were used as a resource for peer-reviewed articles to highlight the topics of dentin hierarchical structure, biomodification agents, and laboratorial investigations of their clinical applications.
Thirty-five thousand actinomycete extracts were screened for anti-Mycobacterium tuberculosis (M. tb) activity, followed by C18 cartridge fractionation of 37 prioritized extracts. Based on MICs against replicating and nonreplicating M.
View Article and Find Full Text PDF