33 research outputs found
Occurrence and diversity of Xanthomonas campestris pv. campestris in vegetable brassica fields in Nepal
Black rot caused by Xanthomonas campestris pv. campestris was found in 28 sampled cabbage fields in five major cabbage-growing districts in Nepal in 2001 and in four cauliflower fields in two districts and a leaf mustard seed bed in 2003. Pathogenic X. campestris pv. campestris strains were obtained from 39 cabbage plants, 4 cauliflower plants, and 1 leaf mustard plant with typical lesions. Repetitive DNA polymerase chain reaction-based fingerprinting (rep-PCR) using repetitive extragenic palindromic, enterobacterial repetitive intergenic consensus, and BOX primers was used to assess the genetic diversity. Strains were also race typed using a differential series of Brassica spp. Cabbage strains belonged to five races (races 1, 4, 5, 6, and 7), with races 4, 1, and 6 the most common. All cauliflower strains were race 4 and the leaf mustard strain was race 6. A dendrogram derived from the combined rep-PCR profiles showed that the Nepalese X. campestris pv. campestris strains clustered separately from other Xanthomonas spp. and pathovars. Race 1 strains clustered together and strains of races 4, 5, and 6 were each split into at least two clusters. The presence of different races and the genetic variability of the pathogen should be considered when resistant cultivars are bred and introduced into regions in Nepal to control black rot of brassicas
Detection of Target ssDNA Using a Microfabricated Hall Magnetometer with Correlated Optical Readout
Sensing biological agents at the genomic level, while enhancing the response time for biodetection over commonly used, optics-based techniques such as nucleic acid microarrays or enzyme-linked immunosorbent assays (ELISAs), is an important criterion for new biosensors. Here, we describe the successful detection of a 35-base, single-strand nucleic acid target by Hall-based magnetic transduction as a mimic for pathogenic DNA target detection. The detection platform has low background, large signal amplification following target binding and can discriminate a single, 350 nm superparamagnetic bead labeled with DNA. Detection of the target sequence was demonstrated at 364 pM (<2 target DNA strands per bead) target DNA in the presence of 36 μM nontarget (noncomplementary) DNA (<10 ppm target DNA) using optical microscopy detection on a GaAs Hall mimic. The use of Hall magnetometers as magnetic transduction biosensors holds promise for multiplexing applications that can greatly improve point-of-care (POC) diagnostics and subsequent medical care
Lives saved with vaccination for 10 pathogens across 112 countries in a pre-COVID-19 world.
BackgroundVaccination is one of the most effective public health interventions. We investigate the impact of vaccination activities for Haemophilus influenzae type b, hepatitis B, human papillomavirus, Japanese encephalitis, measles, Neisseria meningitidis serogroup A, rotavirus, rubella, Streptococcus pneumoniae, and yellow fever over the years 2000-2030 across 112 countries.MethodsTwenty-one mathematical models estimated disease burden using standardised demographic and immunisation data. Impact was attributed to the year of vaccination through vaccine-activity-stratified impact ratios.ResultsWe estimate 97 (95%CrI[80, 120]) million deaths would be averted due to vaccination activities over 2000-2030, with 50 (95%CrI[41, 62]) million deaths averted by activities between 2000 and 2019. For children under-5 born between 2000 and 2030, we estimate 52 (95%CrI[41, 69]) million more deaths would occur over their lifetimes without vaccination against these diseases.ConclusionsThis study represents the largest assessment of vaccine impact before COVID-19-related disruptions and provides motivation for sustaining and improving global vaccination coverage in the future.FundingVIMC is jointly funded by Gavi, the Vaccine Alliance, and the Bill and Melinda Gates Foundation (BMGF) (BMGF grant number: OPP1157270 / INV-009125). Funding from Gavi is channelled via VIMC to the Consortium's modelling groups (VIMC-funded institutions represented in this paper: Imperial College London, London School of Hygiene and Tropical Medicine, Oxford University Clinical Research Unit, Public Health England, Johns Hopkins University, The Pennsylvania State University, Center for Disease Analysis Foundation, Kaiser Permanente Washington, University of Cambridge, University of Notre Dame, Harvard University, Conservatoire National des Arts et Métiers, Emory University, National University of Singapore). Funding from BMGF was used for salaries of the Consortium secretariat (authors represented here: TBH, MJ, XL, SE-L, JT, KW, NMF, KAMG); and channelled via VIMC for travel and subsistence costs of all Consortium members (all authors). We also acknowledge funding from the UK Medical Research Council and Department for International Development, which supported aspects of VIMC's work (MRC grant number: MR/R015600/1).JHH acknowledges funding from National Science Foundation Graduate Research Fellowship; Richard and Peggy Notebaert Premier Fellowship from the University of Notre Dame. BAL acknowledges funding from NIH/NIGMS (grant number R01 GM124280) and NIH/NIAID (grant number R01 AI112970). The Lives Saved Tool (LiST) receives funding support from the Bill and Melinda Gates Foundation.This paper was compiled by all coauthors, including two coauthors from Gavi. Other funders had no role in study design, data collection, data analysis, data interpretation, or writing of the report. All authors had full access to all the data in the study and had final responsibility for the decision to submit for publication
In Support of a Patient-Driven Initiative and Petition to Lower the High Price of Cancer Drugs
Comment in
Lowering the High Cost of Cancer Drugs--III. [Mayo Clin Proc. 2016]
Lowering the High Cost of Cancer Drugs--I. [Mayo Clin Proc. 2016]
Lowering the High Cost of Cancer Drugs--IV. [Mayo Clin Proc. 2016]
In Reply--Lowering the High Cost of Cancer Drugs. [Mayo Clin Proc. 2016]
US oncologists call for government regulation to curb drug price rises. [BMJ. 2015
Estimating the health impact of vaccination against ten pathogens in 98 low-income and middle-income countries from 2000 to 2030: a modelling study.
BACKGROUND: The past two decades have seen expansion of childhood vaccination programmes in low-income and middle-income countries (LMICs). We quantify the health impact of these programmes by estimating the deaths and disability-adjusted life-years (DALYs) averted by vaccination against ten pathogens in 98 LMICs between 2000 and 2030. METHODS: 16 independent research groups provided model-based disease burden estimates under a range of vaccination coverage scenarios for ten pathogens: hepatitis B virus, Haemophilus influenzae type B, human papillomavirus, Japanese encephalitis, measles, Neisseria meningitidis serogroup A, Streptococcus pneumoniae, rotavirus, rubella, and yellow fever. Using standardised demographic data and vaccine coverage, the impact of vaccination programmes was determined by comparing model estimates from a no-vaccination counterfactual scenario with those from a reported and projected vaccination scenario. We present deaths and DALYs averted between 2000 and 2030 by calendar year and by annual birth cohort. FINDINGS: We estimate that vaccination of the ten selected pathogens will have averted 69 million (95% credible interval 52-88) deaths between 2000 and 2030, of which 37 million (30-48) were averted between 2000 and 2019. From 2000 to 2019, this represents a 45% (36-58) reduction in deaths compared with the counterfactual scenario of no vaccination. Most of this impact is concentrated in a reduction in mortality among children younger than 5 years (57% reduction [52-66]), most notably from measles. Over the lifetime of birth cohorts born between 2000 and 2030, we predict that 120 million (93-150) deaths will be averted by vaccination, of which 58 million (39-76) are due to measles vaccination and 38 million (25-52) are due to hepatitis B vaccination. We estimate that increases in vaccine coverage and introductions of additional vaccines will result in a 72% (59-81) reduction in lifetime mortality in the 2019 birth cohort. INTERPRETATION: Increases in vaccine coverage and the introduction of new vaccines into LMICs have had a major impact in reducing mortality. These public health gains are predicted to increase in coming decades if progress in increasing coverage is sustained. FUNDING: Gavi, the Vaccine Alliance and the Bill & Melinda Gates Foundation
Estimating the health impact of vaccination against ten pathogens in 98 low-income and middle-income countries from 2000 to 2030: a modelling study.
BACKGROUND: The past two decades have seen expansion of childhood vaccination programmes in low-income and middle-income countries (LMICs). We quantify the health impact of these programmes by estimating the deaths and disability-adjusted life-years (DALYs) averted by vaccination against ten pathogens in 98 LMICs between 2000 and 2030. METHODS: 16 independent research groups provided model-based disease burden estimates under a range of vaccination coverage scenarios for ten pathogens: hepatitis B virus, Haemophilus influenzae type B, human papillomavirus, Japanese encephalitis, measles, Neisseria meningitidis serogroup A, Streptococcus pneumoniae, rotavirus, rubella, and yellow fever. Using standardised demographic data and vaccine coverage, the impact of vaccination programmes was determined by comparing model estimates from a no-vaccination counterfactual scenario with those from a reported and projected vaccination scenario. We present deaths and DALYs averted between 2000 and 2030 by calendar year and by annual birth cohort. FINDINGS: We estimate that vaccination of the ten selected pathogens will have averted 69 million (95% credible interval 52-88) deaths between 2000 and 2030, of which 37 million (30-48) were averted between 2000 and 2019. From 2000 to 2019, this represents a 45% (36-58) reduction in deaths compared with the counterfactual scenario of no vaccination. Most of this impact is concentrated in a reduction in mortality among children younger than 5 years (57% reduction [52-66]), most notably from measles. Over the lifetime of birth cohorts born between 2000 and 2030, we predict that 120 million (93-150) deaths will be averted by vaccination, of which 58 million (39-76) are due to measles vaccination and 38 million (25-52) are due to hepatitis B vaccination. We estimate that increases in vaccine coverage and introductions of additional vaccines will result in a 72% (59-81) reduction in lifetime mortality in the 2019 birth cohort. INTERPRETATION: Increases in vaccine coverage and the introduction of new vaccines into LMICs have had a major impact in reducing mortality. These public health gains are predicted to increase in coming decades if progress in increasing coverage is sustained. FUNDING: Gavi, the Vaccine Alliance and the Bill & Melinda Gates Foundation
Enhanced conductivity of thin film polyaniline by self-assembled transition metal complexes
In a recent study, the transition metal complex, cis-dichlorobis(2-, 2′-dipyridyl)ruthenium (II) (Ru(bpy)2Cl2), and the macrocycle Ru(TPP)CO (TPP: - tetraphenylporphine) were bound to pyridine terminated self-assembled monolayers on quartz. Following modification of the quartz surface with metal complexes, the conducting polymer polyaniline was deposited via in situ polymerization. The sheet conductivity (as measured by the four-probe method) of the resulting polyaniline films deposited onto Ru(bpy)2Cl2 and Ru(TPP)CO surfaces was significantly enhanced relative to films deposited onto unmodified quartz. It is postulated that either the macrocycle or the transition metal complex-modified surface interacts with the conducting polymer as it is forming, resulting in a more ordered expanded coil conformation for the polymer. The net result of such an interaction is a thin film possessing significantly greater electrical conductivity. © 2007 American Chemical Society
Effects of Palladium(II) Chlorocomplex Speciation on the Controlled Interaction with a Polyaniline Film in Acid
In this study, we
determined the Pd(II) chlorocomplex species that
has the most favorable interaction with an electropolymerized and
protonated polyaniline (PANI) film. This study was completed with
the intent to use this species to electrochemically build atomic palladium
clusters in the PANI matrix. Varying amounts of NaCl were added to
a K<sub>2</sub>PdCl<sub>4</sub>/HClO<sub>4</sub> solution to result
in three species studied: PdCl<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>, PdCl<sub>3</sub>(H<sub>2</sub>O)<sup>−</sup>, and PdCl<sub>4</sub><sup>2–</sup>. UV–vis spectroscopy was used
to confirm the speciation, and Raman spectroscopy, X-ray photoelectron
spectroscopy, and cyclic voltammograms were used to probe the interaction
between the Pd species and PANI. It was determined that PdCl<sub>3</sub>(H<sub>2</sub>O)<sup>−</sup> most effectively interacts with
PANI as a result of the charge balance between the anion and the protonated
nitrogen-containing groups in the polymer. It has been also found
that some fraction of inserted Pd(II) cannot be reduced to Pd(0)
Unraveling the Biomolecular Snapshots of Mitosis in Healthy and Cancer Cells Using Plasmonically-Enhanced Raman Spectroscopy
Owing
to the dynamic and complex nature of mitosis, precise and
timely executions of biomolecular events are critical for high fidelity
cell division. In this context, visualization of such complex events
at the molecular level can provide vital information on the biomolecular
processes in abnormal cells. Here, we explored the plasmonically enhanced
light scattering properties of functionalized gold nanocubes (AuNCs)
together with surface-enhanced Raman spectroscopy (SERS) to unravel
the complex and dynamic biological processes involved in mitosis of
healthy and cancerous cells from its molecular perspectives. By monitoring
various stages of mitosis using SERS, we noticed that relatively high
rate of conversion of mitotic proteins from their α-helix structure
to β-sheet conformation is likely in the cancer cells during
meta-, ana-, and telophases. Unique biochemical modifications to the
lipid and amino acid moieties, associated with the observed protein
conformational modifications, were also identified. However, in healthy
cells, the existence of proteins in their β conformation was
momentary and was largely in the α-helix form. The role of abnormal
conformational modifications of mitotic proteins on the development
of anomalous mitotic activities was further confirmed by looking at
plasmonic nanoparticle-induced cytokinesis failure in cancer cells.
Our findings illustrate the vast possibilities of SERS in real-time
tracking of complex, subtle, and momentary modifications of biomolecules
in live cells, which could provide new insights to the role of protein
conformation dynamics during mitosis on the development of cancer
and many other diseases
Unraveling the Biomolecular Snapshots of Mitosis in Healthy and Cancer Cells Using Plasmonically-Enhanced Raman Spectroscopy
Owing
to the dynamic and complex nature of mitosis, precise and
timely executions of biomolecular events are critical for high fidelity
cell division. In this context, visualization of such complex events
at the molecular level can provide vital information on the biomolecular
processes in abnormal cells. Here, we explored the plasmonically enhanced
light scattering properties of functionalized gold nanocubes (AuNCs)
together with surface-enhanced Raman spectroscopy (SERS) to unravel
the complex and dynamic biological processes involved in mitosis of
healthy and cancerous cells from its molecular perspectives. By monitoring
various stages of mitosis using SERS, we noticed that relatively high
rate of conversion of mitotic proteins from their α-helix structure
to β-sheet conformation is likely in the cancer cells during
meta-, ana-, and telophases. Unique biochemical modifications to the
lipid and amino acid moieties, associated with the observed protein
conformational modifications, were also identified. However, in healthy
cells, the existence of proteins in their β conformation was
momentary and was largely in the α-helix form. The role of abnormal
conformational modifications of mitotic proteins on the development
of anomalous mitotic activities was further confirmed by looking at
plasmonic nanoparticle-induced cytokinesis failure in cancer cells.
Our findings illustrate the vast possibilities of SERS in real-time
tracking of complex, subtle, and momentary modifications of biomolecules
in live cells, which could provide new insights to the role of protein
conformation dynamics during mitosis on the development of cancer
and many other diseases