86 research outputs found

    Contribution of intermediate-volatility organic compounds from on-road transport to secondary organic aerosol levels in Europe

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    Atmospheric organic compounds with an effective saturation concentration (C∗) at 298 K between 103 and 106 µg m−3 are called intermediate-volatility organic compounds (IVOCs), and they have been identified as important secondary organic aerosol (SOA) precursors. In this work, we simulate IVOCs emitted from on-road diesel and gasoline vehicles over Europe with a chemical transport model (CTM), utilizing a new approach in which IVOCs are treated as lumped species that preserve their chemical characteristics. This approach allows us to assess both the overall contribution of IVOCs to SOA formation and the role of specific compounds. For the simulated early-summer period, the highest concentrations of SOA formed from the oxidation of on-road IVOCs (SOA-iv) are predicted for major European cities, like Paris, Athens, and Madrid. In these urban environments, on-road SOA-iv can account for up to a quarter of the predicted total SOA. Over Europe, unspeciated cyclic alkanes in the IVOC range are estimated to account for up to 72 % of the total on-road SOA-iv mass, with compounds with 15 to 20 carbons being the most prominent precursors. The sensitivity of the predicted SOA-iv concentrations to the selected parameters of the new lumping scheme is also investigated. Active multigenerational aging of the secondary aerosol products has the most significant effect as it increases the predicted SOA-iv concentrations by 67 %.</p

    CCDB: a curated database of genes involved in cervix cancer

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    The Cervical Cancer gene DataBase (CCDB, http://crdd.osdd.net/raghava/ccdb) is a manually curated catalog of experimentally validated genes that are thought, or are known to be involved in the different stages of cervical carcinogenesis. In spite of the large women population that is presently affected from this malignancy still at present, no database exists that catalogs information on genes associated with cervical cancer. Therefore, we have compiled 537 genes in CCDB that are linked with cervical cancer causation processes such as methylation, gene amplification, mutation, polymorphism and change in expression level, as evident from published literature. Each record contains details related to gene like architecture (exon–intron structure), location, function, sequences (mRNA/CDS/protein), ontology, interacting partners, homology to other eukaryotic genomes, structure and links to other public databases, thus augmenting CCDB with external data. Also, manually curated literature references have been provided to support the inclusion of the gene in the database and establish its association with cervix cancer. In addition, CCDB provides information on microRNA altered in cervical cancer as well as search facility for querying, several browse options and an online tool for sequence similarity search, thereby providing researchers with easy access to the latest information on genes involved in cervix cancer

    How can we objectively categorise partnership type? A novel classification of population survey data to inform epidemiological research and clinical practice

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    Abstract: Background Partnership type is a determinant of STI risk; yet, it is poorly and inconsistently recorded in clinical practice and research. We identify a novel, empirical-based categorisation of partnership type, and examine whether reporting STI diagnoses varies by the resulting typologies. Methods: Analyses of probability survey data collected from 15 162 people aged 16–74 who participated in Britain's third National Survey of Sexual Attitudes and Lifestyles were undertaken during 2010–2012. Computer-assisted self-interviews asked about participants' ≤3 most recent partners (N=14 322 partners/past year). Analysis of variance and regression tested for differences in partnership duration and perceived likelihood of sex again across 21 ‘partnership progression types’ (PPTs) derived from relationship status at first and most recent sex. Multivariable regression examined the association between reporting STI diagnoses and partnership type(s) net of age and reported partner numbers (all past year). Results: The 21 PPTs were grouped into four summary types: ‘cohabiting’, ‘now steady’, ‘casual’ and ‘ex-steady’ according to the average duration and likelihood of sex again. 11 combinations of these summary types accounted for 94.5% of all men; 13 combinations accounted for 96.9% of all women. Reporting STI diagnoses varied by partnership-type combination, including after adjusting for age and partner numbers, for example, adjusted OR: 6.03 (95% CI 2.01 to 18.1) for men with two ‘casual’ and one ‘now steady’ partners versus men with one ‘cohabiting’ partner. Conclusions: This typology provides an objective method for measuring partnership type and demonstrates its importance in understanding STI risk, net of partner numbers. Epidemiological research and clinical practice should use these methods and results to maximise individual and public health benefit

    Genetic dissection reveals diabetes loci proximal to the gimap5 lymphopenia gene

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    rats are protected from type 1 diabetes (T1D) by 34 Mb of F344 DNA introgressed proximal to the gimap5 lymphopenia gene. To dissect the genetic factor(s) that confer protection from T1D in the DRF. f/f rat line, DRF. f/f rats were crossed to inbred BBDR or DR. lyp/lyp rats to generate congenic sublines that were genotyped and monitored for T1D, and positional candidate genes were sequenced. All (100%) DR. f/f congenic sublines further refined the RNO4 region 1 interval to ϳ670 kb and region 2 to the 340 kb proximal to gimap5. All congenic DRF. f/f sublines were prone to low-grade pancreatic mononuclear cell infiltration around ducts and vessels, but Ͻ20% of islets in nondiabetic rats showed islet infiltration. Coding sequence analysis revealed TCR V␤ 8E, 12, and 13 as candidate genes in region 1 and znf467 and atp6v0e2 as candidate genes in region 2. Our results show that spontaneous T1D is controlled by at least two genetic loci 7 Mb apart on rat chromosome 4. type 1 diabetes; BB rat; T cell receptor; autoimmune CHARACTERISTICS OF TYPE 1 DIABETES (T1D) in both human and the BioBreeding spontaneously diabetes-prone (BBDP) rat include polyuria, hyperglycemia, ketoacidosis, insulitis, and insulin dependency for life. As in human T1D, islets are infiltrated by mononuclear cells at the time of onset with rapid hyperglycemia due to a complete loss of islet ␤-cells (32). The genetic etiology of human T1D remains complex and although the major histocompatibility complex (MHC) (HLA DQ) on chromosome 6 accounts for ϳ40% of T1D risk, the number of non-HLA genetic factors is increasing steadily (2, 7). The BB rat offers a powerful model to dissect both genetic contributions and mechanisms by which immunemediated beta cell killing induces T1D (3, 4, 15, 17-21, 27, 28, 46). As in humans, the major genetic determinant of susceptibility in the BB rat is the MHC (Iddm1) on rat chromosome (RNO) 20. The class II MHC locus RT1B/D. u/u ), an ortholog of human HLA DQ (9), is necessary but not sufficient for T1D in the BBDP rat and other RT1. u/u -related rat strains with spontaneous (24, 47) or induced T1D (8, 43). In BBDP, a null mutation in the gimap5 gene (lyp; Iddm2) on RNO4 (14, 27) causes lymphopenia and is tightly linked to spontaneous T1D development. The DR. lyp/lyp rat with 2 Mb of BBDP DNA encompassing gimap5 introgressed into the genome of related BBDR rats (BioBreeding resistant to spontaneous T1D) are also 100% lymphopenic and 100% spontaneously diabetic (11). With complete T1D penetrance and tight regulation of onset, the congenic DR. lyp/lyp rat line offers distinct advantages in identification of genes responsible for disease progression. It is possible to induce T1D in BBDR rats (32) and related RT1 u/u rats (8) by administration of polyinosinic: polycytidylic acid (poly I:C, an activator of innate immunity), the T reg depleting cytotoxic DS4.23 anti-ART2.1 (formerly RT6) monoclonal antibody or by viral infection (34). This indicates that the BBDR has an underlying genetic susceptibility to T1D. In crosses between WF and either BBDP or BBDR rats, a quantitative trait locus (QTL) important for induced T1D (Iddm14, previously designated Iddm4) was mapped to RNO4 (6, Interestingly, F344 DNA introgressed between D4Rat253 and D4Rhw6 into the congenic DR. lyp/lyp genetic background resulted in a lymphopenic but nondiabetic rat (designated DRF. f/f ) (11). Protection from T1D in the DRF. f/f congenic rat line led us to conclude that spontaneous T1D in the BB rat is controlled, in part, by a diabetogenic factor(s) independent of the gimap5 mutation (76.84 Mb) on RNO4. This congenic interval is encompassed within Iddm14, raising the possibility that the Iddm14 locus could be required for both spontaneous and induced T1D in the BB rat. The aim of this study was to cross the DRF. f/f rat to BBDR and DR. lyp/lyp rats and produce recombinant sublines that could be assessed for both lymphopenia and diabetes and to estimate the number of independent genes on RNO4 that control spontaneous T1D

    Aberrant Cortical Activity in Multiple GCaMP6-Expressing Transgenic Mouse Lines

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    Transgenic mouse lines are invaluable tools for neuroscience but, as with any technique, care must be taken to ensure that the tool itself does not unduly affect the system under study. Here we report aberrant electrical activity, similar to interictal spikes, and accompanying fluorescence events in some genotypes of transgenic mice expressing GCaMP6 genetically encoded calcium sensors. These epileptiform events have been observed particularly, but not exclusively, in mice with Emx1-Cre and Ai93 transgenes, of either sex, across multiple laboratories. The events occur at >0.1 Hz, are very large in amplitude (>1.0 mV local field potentials, >10% df/f widefield imaging signals), and typically cover large regions of cortex. Many properties of neuronal responses and behavior seem normal despite these events, although rare subjects exhibit overt generalized seizures. The underlying mechanisms of this phenomenon remain unclear, but we speculate about possible causes on the basis of diverse observations. We encourage researchers to be aware of these activity patterns while interpreting neuronal recordings from affected mouse lines and when considering which lines to study

    Systemic delivery of E6/7 siRNA using novel lipidic particles and its application with cisplatin in cervical cancer mouse models

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    Small interfering RNA (siRNA) shows great promise in cancer therapy, but its effectiveness in vivo still remains a crucial issue for its transition into the clinics. Although the successful use of polyethylene glycol (PEG)ylated lipidic delivery systems have already been reported, most of the formulation procedures used are labour intensive and also result in unstable end products. We have previously developed a simple yet efficient hydration-of-freeze-dried- matrix (HFDM) method to entrap siRNA within lipid particles, in which the products exhibited superior stability. Here, we show that these HFDM-formulated particles are stable in the presence of serum and can deliver siRNA efficiently to tumours after intravenous administration. Using these particles, around 50% knockdown of the target gene expression was observed in tumours. With the use of siRNA targeting the E6/7 oncogenes expressed in cervical cancer, we showed a 50% reduction in tumour size. This level of tumour growth suppression was comparable to that achieved from cisplatin at the clinically used dose. Overall, our results demonstrate the feasibility of using HFDM-formulated particles to systematically administer E6/7-targeted siRNA for cervical cancer treatment. The simplicity of preparation procedure along with superior product stability obtained from our method offers an innovative approach for the in vivo delivery of siRNA

    Prevalence and burden of HBV co-infection among people living with HIV:A global systematic review and meta-analysis

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    Globally, in 2017 35 million people were living with HIV (PLHIV) and 257 million had chronic HBV infection (HBsAg positive). The extent of HIV-HBsAg co-infection is unknown. We undertook a systematic review to estimate the global burden of HBsAg co-infection in PLHIV. We searched MEDLINE, Embase and other databases for published studies (2002-2018) measuring prevalence of HBsAg among PLHIV. The review was registered with PROSPERO (#CRD42019123388). Populations were categorized by HIV-exposure category. The global burden of co-infection was estimated by applying regional co-infection prevalence estimates to UNAIDS estimates of PLHIV. We conducted a meta-analysis to estimate the odds of HBsAg among PLHIV compared to HIV-negative individuals. We identified 506 estimates (475 studies) of HIV-HBsAg co-infection prevalence from 80/195 (41.0%) countries. Globally, the prevalence of HIV-HBsAg co-infection is 7.6% (IQR 5.6%-12.1%) in PLHIV, or 2.7 million HIV-HBsAg co-infections (IQR 2.0-4.2). The greatest burden (69% of cases; 1.9 million) is in sub-Saharan Africa. Globally, there was little difference in prevalence of HIV-HBsAg co-infection by population group (approximately 6%-7%), but it was slightly higher among people who inject drugs (11.8% IQR 6.0%-16.9%). Odds of HBsAg infection were 1.4 times higher among PLHIV compared to HIV-negative individuals. There is therefore, a high global burden of HIV-HBsAg co-infection, especially in sub-Saharan Africa. Key prevention strategies include infant HBV vaccination, including a timely birth-dose. Findings also highlight the importance of targeting PLHIV, especially high-risk groups for testing, catch-up HBV vaccination and other preventative interventions. The global scale-up of antiretroviral therapy (ART) for PLHIV using a tenofovir-based ART regimen provides an opportunity to simultaneously treat those with HBV co-infection, and in pregnant women to also reduce mother-to-child transmission of HBV alongside HIV

    Chlamydia trachomatis infection during pregnancy associated with preterm delivery: a population-based prospective cohort study

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    Chlamydia trachomatis infection is the most prevalent bacterial sexually transmitted infection and may influence pregnancy outcome. This study was conducted to assess the effect of chlamydial infection during pregnancy on premature delivery and birthweight. Pregnant women attending a participating midwifery practice or antenatal clinic between February 2003 and January 2005 were eligible for the study. From 4,055 women self-administered questionnaires and urine samples, tested by PCR, were analysed for C. trachomatis infection. Pregnancy outcomes were obtained from midwives and hospital registries. Gestational ages and birthweights were analysed for 3,913 newborns. The C. trachomatis prevalence was 3.9%, but varied by age and socio-economic background. Chlamydial infection was, after adjustment for potential confounders, associated with preterm delivery before 32 weeks (OR 4.35 [95% CI 1.3, 15.2]) and 35 weeks gestation (OR 2.66 [95% CI 1.1, 6.5]), but not with low birthweight. Of all deliveries before 32 weeks and 35 weeks gestation 14.9% [95% CI 4.5, 39.5] and 7.4% [95% CI 2.5, 20.1] was attributable to C. trachomatis infection. Chlamydia trachomatis infection contributes significantly to early premature delivery and should be considered a public health problem, especially in young women and others at increased risk of C. trachomatis infection
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