520 research outputs found
M. tuberculosis genotypic diversity and drug susceptibility pattern in HIV- infected and non-HIV-infected patients in northern Tanzania
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53004.pdf (publisher's version ) (Open Access)BACKGROUND: Tuberculosis (TB) is a major health problem and HIV is the major cause of the increase in TB. Sub-Saharan Africa is endemic for both TB and HIV infection. Determination of the prevalence of M. tuberculosis strains and their drug susceptibility is important for TB control.TB positive culture, BAL fluid or sputum samples from 130 patients were collected and genotyped. The spoligotypes were correlated with anti-tuberculous drug susceptibility in HIV-infected and non-HIV patients from Tanzania. RESULTS: One-third of patients were TB/HIV co-infected. Forty-seven spoligotypes were identified.Fourteen isolates (10.8%) had new and unique spoligotypes while 116 isolates (89.2%) belonged to 33 known spoligotypes. The major spoligotypes contained nine clusters: CAS1-Kili 30.0%, LAM11- ZWE 14.6%, ND 9.2%, EAI 6.2%, Beijing 5.4%, T-undefined 4.6%, CAS1-Delhi 3.8%, T1 3.8% and LAM9 3.8%. Twelve (10.8%) of the 111 phenotypically tested strains were resistant to anti-TB drugs. Eight (7.2%) were monoresistant strains: 7 to isoniazid (INH) and one to streptomycin. Four strains (3.5%) were resistant to multiple drugs: one (0.9%) was resistant to INH and streptomycin and the other three (2.7%) were MDR strains: one was resistant to INH, rifampicin and ethambutol and two were resistant to all four anti-TB drugs. Mutation in the katG gene codon 315 and the rpoB hotspot region showed a low and high sensitivity, respectively, as predictor of phenotypic drug resistance. CONCLUSION: CAS1-Kili and LAM11-ZWE were the most common families. Strains of the Beijing family and CAS1-Kili were not or least often associated with resistance, respectively. HIV status was not associated with spoligotypes, resistance or previous TB treatment
A lanthanum picrate complex of a 1,2-bisamide substituted calix[4]arene
The synthesis and structural characterization of a lanthanum picrate complex of the proximally-substituted calix[4]arene bisamide, 5,11,17,23-tetra-tert-butyl-25,26- bis(diethylcarbamoylmethoxy)-27,28-dihydroxycalix[4] arene (L), is reported. The complex is formulated as [La(L-H)(picrate)2]2.75CH2Cl2 and crystallises with two inequivalent metal complexes in the unit cell. The differing dispositions of the picrate anions in the two complexes suggest that intramolecular interactions between the aromatic rings of the picrate and calixarene are less significant than the forces involved in the crystal packing of the complexes
Gene-Expression Signature Predicts Postoperative Recurrence in Stage I Non-Small Cell Lung Cancer Patients
About 30% stage I non-small cell lung cancer (NSCLC) patients undergoing resection will recur. Robust prognostic markers are required to better manage therapy options. The purpose of this study is to develop and validate a novel gene-expression signature that can predict tumor recurrence of stage I NSCLC patients. Cox proportional hazards regression analysis was performed to identify recurrence-related genes and a partial Cox regression model was used to generate a gene signature of recurrence in the training dataset −142 stage I lung adenocarcinomas without adjunctive therapy from the Director's Challenge Consortium. Four independent validation datasets, including GSE5843, GSE8894, and two other datasets provided by Mayo Clinic and Washington University, were used to assess the prediction accuracy by calculating the correlation between risk score estimated from gene expression and real recurrence-free survival time and AUC of time-dependent ROC analysis. Pathway-based survival analyses were also performed. 104 probesets correlated with recurrence in the training dataset. They are enriched in cell adhesion, apoptosis and regulation of cell proliferation. A 51-gene expression signature was identified to distinguish patients likely to develop tumor recurrence (Dxy = −0.83, P<1e-16) and this signature was validated in four independent datasets with AUC >85%. Multiple pathways including leukocyte transendothelial migration and cell adhesion were highly correlated with recurrence-free survival. The gene signature is highly predictive of recurrence in stage I NSCLC patients, which has important prognostic and therapeutic implications for the future management of these patients
A self-organized model for cell-differentiation based on variations of molecular decay rates
Systemic properties of living cells are the result of molecular dynamics
governed by so-called genetic regulatory networks (GRN). These networks capture
all possible features of cells and are responsible for the immense levels of
adaptation characteristic to living systems. At any point in time only small
subsets of these networks are active. Any active subset of the GRN leads to the
expression of particular sets of molecules (expression modes). The subsets of
active networks change over time, leading to the observed complex dynamics of
expression patterns. Understanding of this dynamics becomes increasingly
important in systems biology and medicine. While the importance of
transcription rates and catalytic interactions has been widely recognized in
modeling genetic regulatory systems, the understanding of the role of
degradation of biochemical agents (mRNA, protein) in regulatory dynamics
remains limited. Recent experimental data suggests that there exists a
functional relation between mRNA and protein decay rates and expression modes.
In this paper we propose a model for the dynamics of successions of sequences
of active subnetworks of the GRN. The model is able to reproduce key
characteristics of molecular dynamics, including homeostasis, multi-stability,
periodic dynamics, alternating activity, differentiability, and self-organized
critical dynamics. Moreover the model allows to naturally understand the
mechanism behind the relation between decay rates and expression modes. The
model explains recent experimental observations that decay-rates (or turnovers)
vary between differentiated tissue-classes at a general systemic level and
highlights the role of intracellular decay rate control mechanisms in cell
differentiation.Comment: 16 pages, 5 figure
Human papillomavirus prevalence in women attending routine cervical screening in South Wales, UK: a cross-sectional study
In this cross-sectional population-based study we determine human papillomavirus (HPV) prevalence in South Wales to provide comprehensive baseline data for future assessment of the impact of prophylactic HPV vaccination and to help inform future screening strategies. Liquid-based cytology samples from women attending routine cervical screening were collected (n=10 000: mean age 38 years, 93% cytology negative, and 64.8% from the 50% least deprived LSOA according to social deprivation score (SDS)). High-Risk (HR) and Low-Risk HPV screening was performed using HPV PCR-EIA with genotyping of HR positives and data correlated with age, SDS and cytology. Overall HPV prevalence was 13.5% (9.3% age standardised) and the most frequent HR types were HPV 16, 31, 18 and 58. In HR HPV-positive cases 42.4% had a single HR type and they were predominant in women with severe cytological abnormalities. Here, 66% of all HR HPV cases were in women aged 30 years of age or less and SDS had no significant effect on HPV status. HPV prevalence increased significantly with degree of dyskarosis from 7% in cytology negative samples to 80% in samples with severe cytological abnormalities (P-value <0.0001). Overall, 46% of HR HPV cases were positive for the two HR types targeted by the prophylactic vaccines (HPV 16 and HPV 18). The data presented represents the largest type-specific investigation of HPV prevalence in an unselected UK population
Finding needles in haystacks: linking scientific names, reference specimens and molecular data for Fungi
DNA phylogenetic comparisons have shown that morphology-based species recognition often underestimates fungal diversity. Therefore, the need for accurate DNA sequence data, tied to both correct taxonomic names and clearly annotated specimen data, has never been greater. Furthermore, the growing number of molecular ecology and microbiome projects using high-throughput sequencing require fast and effective methods for en masse species assignments. In this article, we focus on selecting and re-annotating a set of marker reference sequences that represent each currently accepted order of Fungi. The particular focus is on sequences from the internal transcribed spacer region in the nuclear ribosomal cistron, derived from type specimens and/or ex-type cultures. Re-annotated and verified sequences were deposited in a curated public database at the National Center for Biotechnology Information (NCBI), namely the RefSeq Targeted Loci (RTL) database, and will be visible during routine sequence similarity searches with NR_prefixed accession numbers. A set of standards and protocols is proposed to improve the data quality of new sequences, and we suggest how type and other reference sequences can be used to improve identification of Fungi
Shotgun Proteomics Identifies Serum Fibronectin as a Candidate Diagnostic Biomarker for Inclusion in Future Multiplex Tests for Ectopic Pregnancy
Ectopic pregnancy (EP) is difficult to diagnose early and accurately. Women often present at emergency departments in early pregnancy with a 'pregnancy of unknown location' (PUL), and diagnosis and exclusion of EP is challenging due to a lack of reliable biomarkers. The objective of this study was to identify novel diagnostic biomarkers for EP. Shotgun proteomics, incorporating combinatorial-ligand library pre-fractionation, was used to interrogate pooled sera (n = 40) from women undergoing surgery for EP, termination of viable intrauterine pregnancy and management of non-viable intrauterine pregnancy. Western blot was used to validate results in individual sera. ELISAs were developed to interrogate sera from women with PUL (n = 120). Sera were collected at time of first symptomatic presentation and categorized according to pregnancy outcome. The main outcome measures were differences between groups and area under the receiver operating curve (ROC). Proteomics identified six biomarker candidates. Western blot detected significant differences in levels of two of these candidates. ELISA of sera from second cohort revealed that these differences were only significant for one of these candidates, fibronectin. ROC analysis of ability of fibronectin to discriminate EP from other pregnancy outcomes suggested that fibronectin has diagnostic potential (ROC 0.6439; 95% CI 0.5090 to 0.7788; P>0.05), becoming significant when 'ambiguous' medically managed PUL excluded from analysis (ROC 0.6538; 95% CI 0.5158 to 0.7918; P<0.05). Fibronectin may make a useful adjunct to future multiplex EP diagnostic tests
Smoking and its effect on scar healing
Scar formation is influenced by several factors such as wound infection, tension, wound depth and anatomical localization. Hypertrophic scarring is often the result of an imbalance in the wound and scar healing process. The exact underlying pathophysiological mechanism remains unclear. Smoking has a higher risk of postoperative complications probably due to a diminished macrophage induction. Following our clinical impression that smokers without postoperative wound infections show esthetically better scars, we evaluated the scars after a reduction mammaplasty in smoking and nonsmoking patients in a prospective clinical trial. Between July 2006 and September 2007, 13 smokers and 30 non smokers with a reduction mammaplasty were included. They were recruited from Viecuri Medical Centre and Atrium Medical Centre in the Netherlands after written consent. Surgical data and data of the patients' condition were collected. Follow-up for erythema values of the scars was done with a colorimeter (The Minolta CR-300, Minolta Camera Co., Ltd., Osaka Japan) at 1, 3, 6 and 9Â months postoperatively on four standardized postsurgical sites. ANOVA and Chi-square test were used for statistical analysis. In the smoking group, the scars were significantly less red compared to the nonsmoking group. No significant differences were found in BMI, resection weight and drain production between both groups. Although smoking is certainly not recommended as a preventive therapy to influence scar healing, this study confirms our assumption that smokers tend to have faster and less erythemateous scar healing to nonsmokers. Further research is needed to understand the mechanism of the effect of smoking on scars
Molecular and cellular mechanisms underlying the evolution of form and function in the amniote jaw.
The amniote jaw complex is a remarkable amalgamation of derivatives from distinct embryonic cell lineages. During development, the cells in these lineages experience concerted movements, migrations, and signaling interactions that take them from their initial origins to their final destinations and imbue their derivatives with aspects of form including their axial orientation, anatomical identity, size, and shape. Perturbations along the way can produce defects and disease, but also generate the variation necessary for jaw evolution and adaptation. We focus on molecular and cellular mechanisms that regulate form in the amniote jaw complex, and that enable structural and functional integration. Special emphasis is placed on the role of cranial neural crest mesenchyme (NCM) during the species-specific patterning of bone, cartilage, tendon, muscle, and other jaw tissues. We also address the effects of biomechanical forces during jaw development and discuss ways in which certain molecular and cellular responses add adaptive and evolutionary plasticity to jaw morphology. Overall, we highlight how variation in molecular and cellular programs can promote the phenomenal diversity and functional morphology achieved during amniote jaw evolution or lead to the range of jaw defects and disease that affect the human condition
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