1,482 research outputs found

    Retinal Changes in a Mutant Form of Goldfish with Megalophthalmia

    Get PDF
    The retinal changes of a mutant strain of goldfish with megalophthalmia were studied by histology, electron microscopy and biochemistry. Changes in the morphology of the pigment epithelium, decrease in number of photoreceptors, thinning out of retinal layers and the existence of spaces in the retina were all features as the eyes grew in size. Invasion of macrophages was also evident in the retina. A decrease in leucine uptake per milligram of retina was also detected as the eye grew beyond 0.8 millilitre in volume. These changes, although related to volume changes (i.e., growth) of the eyes, were found to have little relationship with increase of intraocular pressure as intraocular pressures in the growing eyes of the mutant strain did not change much. Goldfish from a control strain with similar eye volumes and sizes (ages) were used for comparison and similar changes as in the mutant were not apparent

    Expansion of a novel endogenous retrovirus throughout the pericentromeres of modern humans

    Get PDF
    Abstract Background Approximately 8% of the human genome consists of sequences of retroviral origin, a result of ancestral infections of the germ line over millions of years of evolution. The most recent of these infections is attributed to members of the human endogenous retrovirus type-K (HERV-K) (HML-2) family. We recently reported that a previously undetected, large group of HERV-K (HML-2) proviruses, which are descendants of the ancestral K111 infection, are spread throughout human centromeres. Results Studying the genomes of certain cell lines and the DNA of healthy individuals that seemingly lack K111, we discover new HERV-K (HML-2) members hidden in pericentromeres of several human chromosomes. All are related through a common ancestor, termed K222, which is a virus that infected the germ line approximately 25 million years ago. K222 exists as a single copy in the genomes of baboons and high order primates, but not New World monkeys, suggesting that progenitor K222 infected the primate germ line after the split between New and Old World monkeys. K222 exists in modern humans at multiple loci spread across the pericentromeres of nine chromosomes, indicating it was amplified during the evolution of modern humans. Conclusions Copying of K222 may have occurred through recombination of the pericentromeres of different chromosomes during human evolution. Evidence of recombination between K111 and K222 suggests that these retroviral sequences have been templates for frequent cross-over events during the process of centromere recombination in humans.http://deepblue.lib.umich.edu/bitstream/2027.42/111301/1/13059_2015_Article_641.pd

    Quantification of injury burden using multiple data sources: a longitudinal study

    Get PDF
    Quantification of injury burden is vital for injury prevention, as it provides a guide for setting policies and priorities. This study generated a set of Hong Kong specific disability weights (DWs) derived from patient experiences and hospital records. Patients were recruited from the Accident and Emergency Department (AED) of three major trauma centers in Hong Kong between September 2014 and December 2015 and subsequently interviewed with a focus on health-related quality of life at most three times over a 12-month period. These patient-reported data were then used for estimation of DWs. The burden of injury was determined using the mortality and inpatient data from 2001 to 2012 and then compared with those reported in the UK Burden of Injury (UKBOI) and global burden of diseases (GBD) studies. There were 22,856 mortality cases and 817,953 morbidity cases caused by injuries, in total contributing to 1,027,641 disability-adjusted life years (DALYs) in the 12-year study timeframe. Estimates for DALYs per 100,000 in Hong Kong amounted to 1192, compared with 2924 in UKBOI and 3459 in GBD. Our findings support the use of multiple data sources including patient-reported data and hospital records for estimation of injury burden

    Treatment with Methylphenidate for Attention Deficit Hyperactivity Disorder (ADHD) and the Risk of All-Cause Poisoning in Children and Adolescents:A Self-Controlled Case Series Study

    Get PDF
    BACKGROUND: Children and adolescents with attention deficit hyperactivity disorder (ADHD) are at higher risk of all-cause poisoning by drugs and chemicals (intentional or accidental). Currently, there is limited data on whether medication treatment for ADHD can reduce the risk of all-cause poisoning. METHODS: Patients aged 5–18 years with a methylphenidate (MPH) prescription and an incident poisoning diagnosis between January 2001 and June 2020 were identified from the Hong Kong Clinical Data Analysis and Reporting System. A self-controlled case series study design was used to compare the incidence rate ratios (IRRs) of all-cause poisoning during different risk windows (30 days before the first MPH prescription, exposure periods within 30 days of the first prescription, and periods of subsequent exposure) compared with the reference window (other non-exposure periods). RESULTS: 42,203 patients were prescribed ADHD medication in Hong Kong during the study period. Of these, 417 patients who had both an MPH prescription and poisoning incident recorded were included in the main analysis. Compared with other non-exposed periods, a higher risk of poisoning was found in the 30 days before the first prescription (IRR 2.64, 95% confidence interval [CI] 1.33–5.22) and exposure periods within 30 days of the first prescription (IRR 2.18, 95% CI 1.06–4.48), but not during prolonged exposure. However, compared with 30 days before the first prescription as well as exposure periods within 30 days of the first prescription, there was a lower risk during the subsequent exposure (IRRs 0.49 and 0.60, respectively). Similar results to the main analysis were also found in the subgroup analysis of intentional poisoning and females, but not in that of accidental poisoning and males. CONCLUSIONS: The risk of all-cause poisoning was higher shortly before and after the first MPH prescription and became lower during the subsequent prescription period. Our results do not support an association between the use of MPH and an increased risk of all-cause poisoning in children and adolescents and, in fact, suggest that longer-term use of MPH may be associated with a lower risk of all-cause poisoning, although this latter finding requires further study. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40263-021-00824-x

    Improvement of electrical properties of ITO thin films by melt-free ultra-short laser crystallization

    Get PDF
    We describe a novel solid state crystallisation method for optimising a thin film transparent conductive oxide when deposited on flexible polymer substrates. The method is based on ultra-short non-thermal laser sintering of indium tin oxide (ITO) thin films. In this study, we used commercial ITO thin films deposited on a flexible polyethylene terephthalate substrate with a relatively low melting temperature compared with ITO on glass. We demonstrate the use of laser scanning with high pulse overlapping at fluences seven times less than the threshold required for melting/damage of ITO. The results confirm greater than four times enhancement in the mobility of charge carriers of ITO thin films after laser scanning and sheet resistance can be reduced up to 25%. There is no reduction in optical transparency observed in laser treated samples. Surface morphology and x-ray diffraction analyses confirm the improvement in crystallite sizes by laser sintering, resulting in a greater than 37% increase in grain size due to enhanced crystallization. Comparison of experimental and simulation based on a delayed two temperature model confirms that ITO thin film crystallization occurred at about one-third of the melting temperature of ITO

    Assessing seroprevalence and associated risk factors for multiple infectious diseases in Sabah, Malaysia using serological multiplex bead assays

    Get PDF
    Background: Infectious diseases continue to burden populations in Malaysia, especially among rural communities where resources are limited and access to health care is difficult. Current epidemiological trends of several neglected tropical diseases in these populations are at present absent due to the lack of habitual and efficient surveillance. To date, various studies have explored the utility of serological multiplex beads to monitor numerous diseases simultaneously. We therefore applied this platform to assess population level exposure to six infectious diseases in Sabah, Malaysia. Furthermore, we concurrently investigated demographic and spatial risk factors that may be associated with exposure for each disease. Methods: This study was conducted in four districts of Northern Sabah in Malaysian Borneo, using an environmentally stratified, population-based cross-sectional serological survey targeted to determine risk factors for malaria. Samples were collected between September to December 2015, from 919 villages totaling 10,100 persons. IgG responses to twelve antigens of six diseases (lymphatic filariasis- Bm33, Bm14, BmR1, Wb123; strongyloides- NIE; toxoplasmosis-SAG2A; yaws- Rp17 and TmpA; trachoma- Pgp3, Ct694; and giardiasis- VSP3, VSP5) were measured using serological multiplex bead assays. Eight demographic risk factors and twelve environmental covariates were included in this study to better understand transmission in this community. Results: Seroprevalence of LF antigens included Bm33 (10.9%), Bm14+ BmR1 (3.5%), and Wb123 (1.7%). Seroprevalence of Strongyloides antigen NIE was 16.8%, for Toxoplasma antigen SAG2A was 29.9%, and Giardia antigens GVSP3 + GVSP5 was 23.2%. Seroprevalence estimates for yaws Rp17 was 4.91%, for TmpA was 4.81%, and for combined seropositivity to both antigens was 1.2%. Seroprevalence estimates for trachoma Pgp3 + Ct694 were 4.5%. Age was a significant risk factors consistent among all antigens assessed, while other risk factors varied among the different antigens. Spatial heterogeneity of seroprevalence was observed more prominently in lymphatic filariasis and toxoplasmosis. Conclusions: Multiplex bead assays can be used to assess serological responses to numerous pathogens simultaneously to support infectious disease surveillance in rural communities, especially where prevalences estimates are lacking for neglected tropical diseases. Demographic and spatial data collected alongside serosurveys can prove useful in identifying risk factors associated with exposure and geographic distribution of transmission

    MicroRNAs in pulmonary arterial remodeling

    Get PDF
    Pulmonary arterial remodeling is a presently irreversible pathologic hallmark of pulmonary arterial hypertension (PAH). This complex disease involves pathogenic dysregulation of all cell types within the small pulmonary arteries contributing to vascular remodeling leading to intimal lesions, resulting in elevated pulmonary vascular resistance and right heart dysfunction. Mutations within the bone morphogenetic protein receptor 2 gene, leading to dysregulated proliferation of pulmonary artery smooth muscle cells, have been identified as being responsible for heritable PAH. Indeed, the disease is characterized by excessive cellular proliferation and resistance to apoptosis of smooth muscle and endothelial cells. Significant gene dysregulation at the transcriptional and signaling level has been identified. MicroRNAs are small non-coding RNA molecules that negatively regulate gene expression and have the ability to target numerous genes, therefore potentially controlling a host of gene regulatory and signaling pathways. The major role of miRNAs in pulmonary arterial remodeling is still relatively unknown although research data is emerging apace. Modulation of miRNAs represents a possible therapeutic target for altering the remodeling phenotype in the pulmonary vasculature. This review will focus on the role of miRNAs in regulating smooth muscle and endothelial cell phenotypes and their influence on pulmonary remodeling in the setting of PAH

    Search for Narrow Diphoton Resonances and for gamma-gamma+W/Z Signatures in p\bar p Collisions at sqrt(s)=1.8 TeV

    Get PDF
    We present results of searches for diphoton resonances produced both inclusively and also in association with a vector boson (W or Z) using 100 pb^{-1} of p\bar p collisions using the CDF detector. We set upper limits on the product of cross section times branching ratio for both p\bar p\to\gamma\gamma + X and p\bar p\to\gamma\gamma + W/Z. Comparing the inclusive production to the expectations from heavy sgoldstinos we derive limits on the supersymmetry-breaking scale sqrt{F} in the TeV range, depending on the sgoldstino mass and the choice of other parameters. Also, using a NLO prediction for the associated production of a Higgs boson with a W or Z boson, we set an upper limit on the branching ratio for H\to\gamma\gamma. Finally, we set a lower limit on the mass of a `bosophilic' Higgs boson (e.g. one which couples only to \gamma, W, and Z$ bosons with standard model couplings) of 82 GeV/c^2 at 95% confidence level.Comment: 30 pages, 11 figure

    Search for the Supersymmetric Partner of the Top-Quark in ppˉp \bar{p} Collisions at s=1.8TeV\sqrt{s} = 1.8 {\rm TeV}

    Full text link
    We report on a search for the supersymmetric partner of the top quark (stop) produced in ttˉt \bar{t} events using 110pb1110 {\rm pb}^{-1} of ppˉp \bar{p} collisions at s=1.8TeV\sqrt{s} = 1.8 {\rm TeV} recorded with the Collider Detector at Fermilab. In the case of a light stop squark, the decay of the top quark into stop plus the lightest supersymmetric particle (LSP) could have a significant branching ratio. The observed events are consistent with Standard Model ttˉt \bar{t} production and decay. Hence, we set limits on the branching ratio of the top quark decaying into stop plus LSP, excluding branching ratios above 45% for a LSP mass up to 40 {\rm GeV/c}2^{2}.Comment: 11 pages, 4 figure
    corecore