446 research outputs found
Objectives and models of the planetary quarantine program
The objectives of the planetary quarantine program are presented and the history of early contamination prevention efforts is outlined. Contamination models which were previously established are given and include: determination of parameters; symbol nomenclature; and calculations of contamination and hazard probabilities. Planetary quarantine is discussed as an issue of national and international concern. Information on international treaty and meetings on spacecraft sterilization, quarantine standards, and policies is provided. The specific contamination probabilities of the U.S.S.R. Venus 3 flyby are included
The Saccharomyces cerevisiae W303-K6001 cross-platform genome sequence: insights into ancestry and physiology of a laboratory mutt
Saccharomyces cerevisiae strain W303 is a widely used model organism. However, little is known about its genetic origins, as it was created in the 1970s from crossing yeast strains of uncertain genealogy. To obtain insights into its ancestry and physiology, we sequenced the genome of its variant W303-K6001, a yeast model of ageing research. The combination of two next-generation sequencing (NGS) technologies (Illumina and Roche/454 sequencing) yielded an 11.8 Mb genome assembly at an N50 contig length of 262 kb. Although sequencing was substantially more precise and sensitive than whole-genome tiling arrays, both NGS platforms produced a number of false positives. At a 378x average coverage, only 74 per cent of called differences to the S288c reference genome were confirmed by both techniques. The consensus W303-K6001 genome differs in 8133 positions from S288c, predicting altered amino acid sequence in 799 proteins, including factors of ageing and stress resistance. The W303-K6001 (85.4%) genome is virtually identical (less than equal to 0.5 variations per kb) to S288c, and thus originates in the same ancestor. Non-S288c regions distribute unequally over the genome, with chromosome XVI the most (99.6%) and chromosome XI the least (54.5%) S288c-like. Several of these clusters are shared with Sigma1278B, another widely used S288c-related model, indicating that these strains share a second ancestor. Thus, the W303-K6001 genome pictures details of complex genetic relationships between the model strains that date back to the early days of experimental yeast genetics. Moreover, this study underlines the necessity of combining multiple NGS and genome-assembling techniques for achieving accurate variant calling in genomic studies
Outbreaks of virulent diarrheagenic Escherichia coli - are we in control?
Shiga toxin-producing Escherichia coli (STEC) are the most virulent diarrheagenic E. coli known to date. They can be spread with alarming ease via food as exemplified by a large sprout-borne outbreak of STEC O104:H4 in 2011 that was centered in northern Germany and affected several countries. Effective control of such outbreaks is an important public health task and necessitates early outbreak detection, fast identification of the outbreak vehicle and immediate removal of the suspected food from the market, flanked by consumer advice and measures to prevent secondary spread
A Clinical Trial to Validate Event-Related Potential Markers of Alzheimer\u27s Disease in Outpatient Settings
INTRODUCTION: We investigated whether event-related potentials (ERP) collected in outpatient settings and analyzed with standardized methods can provide a sensitive and reliable measure of the cognitive deficits associated with early Alzheimer\u27s disease (AD).
METHODS: A total of 103 subjects with probable mild AD and 101 healthy controls were recruited at seven clinical study sites. Subjects were tested using an auditory oddball ERP paradigm.
RESULTS: Subjects with mild AD showed lower amplitude and increased latency for ERP features associated with attention, working memory, and executive function. These subjects also had decreased accuracy and longer reaction time in the target detection task associated with the ERP test.
DISCUSSION: Analysis of ERP data showed significant changes in subjects with mild AD that are consistent with the cognitive deficits found in this population. The use of an integrated hardware/software system for data acquisition and automated data analysis methods make administration of ERP tests practical in outpatient settings
Ongoing outbreaks of hepatitis A among men who have sex with men (MSM), Berlin, November 2016 to January 2017 – linked to other German cities and European countries
Since 14 November 2016, 38 cases of hepatitis A have been notified in Berlin; of these, 37 were male and 30 reported to have sex with men (MSM). Median age of MSM cases is 31 years (range: 24–52 years). Phylogenetic analysis revealed three distinct sequences, linking cases in Berlin to those in other German cities and to clusters recognised in other European countries in 2016
Thin PDMS Films Using Long Spin Times or Tert-Butyl Alcohol as a Solvent
Thin polydimethylsiloxane (PDMS) films are frequently used in “lab on a chip” devices as flexible membranes. The common solvent used to dilute the PDMS for thin films is hexane, but hexane can swell the underlying PDMS substrate. A better solvent would be one that dissolves uncured PDMS but doesn't swell the underlying substrate. Here, we present protocols and spin curves for two alternatives to hexane dilution: longer spin times and dilution in tert-butyl alcohol. The thickness of the PDMS membranes under different spin speeds, spin times, and PDMS concentrations was measured using an optical profilometer. The use of tert-butyl alcohol to spin thin PDMS films does not swell the underlying PDMS substrate, and we have used these films to construct multilayer PDMS devices
Angiotensin II, via angiotensin receptor type 1/nuclear factor-κB activation, causes a synergistic effect on interleukin-1-β-induced inflammatory responses in cultured mesangial cells
Introduction: The nuclear factor-κB (NF-κB) is an important regulator of the inflammatory response. Angiotensin II
(Ang II) activates the NF-κB pathway linked to renal inflammation. Although both AT1 and AT2 receptors are involved
in Ang II-mediated NF-κB activation, the biological processes mediated by each receptor are not fully characterized.
Interleukin-1β (IL-1β) is an important macrophage-derived cytokine that regulates immune and inflammatory processes,
activating intracellular pathways shared with Ang II, including the NF-κB.
Materials and methods: In vitro studies were done in primary cultured rat mesangial cells. NF-κB pathway was
evaluated by phosphorylated levels of p65/IκB and DNA binding activity. The Ang II receptor subtype was determined
by pretreatment with AT1 and AT2 antagonists.
Results: In mesangial cells the simultaneous presence of Ang II and IL-1β caused a synergistic activation of the NF-κB
pathway and a marked upregulation of proinflammatory factors under NF-κB control, including monocyte chemoattractant
protein-1. The AT1, but not AT2, antagonist abolished the synergistic effect on NF-κB activation and proinflammatory
genes caused by coincubation of Ang II and IL-1β.
Conclusions: These data indicates that Ang II, via AT1/NF-κB pathway activation, cooperates with IL-β to increase the
inflammatory response in mesangial cellsThis work was supported by grants from the Instituto de Salud
Carlos III (ISCIIIRETIC REDinREN RD06/0016, RD12/0021,
PI11/01854), Comunidad de Madrid (Fibroteam S2010/BMD-
2321, S2010/BMD-2378), and Research Institute Queen Sophia
(IRSIN). Programa Intensificación Actividad Investigadora
(ISCIII/Agencia Laín-Entralgo/CM) to AO. MA and ESL are supported
by a ‘Sara Borrell’ postdoctoral contract from Instituto de
Salud Carlos III (CD10/00347 and CD09/00066, respectively
Identifying outbreaks of sexually transmitted infection: who cares?
BACKGROUND: Current routine surveillance schemes for sexually transmitted infections (STIs) in the United Kingdom (UK) are not designed for outbreak identification. Recognising STI outbreaks, therefore, depends almost entirely on the alertness of health professionals. The objective of this study was to explore health professionals' knowledge of, and attitudes towards, identification and investigation of STI outbreaks in Wales. METHODS: We conducted a cross-sectional survey in Wales in June 2005, and sent a questionnaire to consultants of genitourinary medicine (GUM, n = 11), a consultant microbiologist from each laboratory (n = 14), all consultants in communicable disease control (n = 5), and to epidemiologists of the National Public Health Service (n = 4). RESULTS: 26 (76%) of 34 survey recipients responded. Of these, 17 (65%) ranked the investigation of STI outbreaks as important or very important, and 19 (73%) perceived participation in the investigation of an STI outbreak as part of their responsibility. Only six (25%) respondents had actively searched their computer system or patient records for a possible STI outbreak in the previous twelve months, and 15 (63%) had never looked for an outbreak. Of seven GUM physicians who said they had identified at least one STI outbreak, three had never informed public health authorities. CONCLUSION: Prompt identification and coordinated investigation of outbreaks, usually through a multidisciplinary outbreak control team, is central to the control of many infectious diseases. This does not appear to be the case for STIs, which we believe represents a lost opportunity to reduce transmission. Besides improved surveillance methods, a change in culture towards STI outbreaks is needed among health professionals in Wales
Escherichia coli O157 Infection and Secondary Spread, Scotland, 1999–2008
To determine the proportion of Escherichia coli O157 cases in Scotland attributable to secondary spread, we analyzed data obtained through entire-population enhanced surveillance. We identified 11% of cases as secondary. Secondary cases in single households were younger than secondary cases in outbreaks affecting >1 household and had similar risk for hemolytic uremic syndrome
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