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51.
Danielle M. Tufts Laura B. Goodman Meghan C. Benedict April D. Davis Meredith C. VanAcker Maria Diuk-Wasser 《International journal for parasitology》2021,51(2-3):149-157
Haemaphysalis longicornis, the Asian longhorned tick, is an invasive ixodid tick that has rapidly spread across the northeastern and southeastern regions of the United States since first reported in 2017. The emergence of H. longicornis presents a potential threat for livestock, wildlife, and human health as the host associations and vector potential of this invasive pest in the United States are poorly understood. Previous field data from the United States has shown that H. longicornis was not associated with natural populations of small mammals or birds, but they show a preference for medium sized mammals in laboratory experiments. Therefore, medium and large sized mammals were sampled on Staten Island, New York, United States, to determine H. longicornis host associations and vector potential for a range of human and veterinary pathogens. A total of 97 hosts were sampled and five species of tick (Amblyomma americanum, Dermacentor variabilis, H. longicornis, Ixodes scapularis, Ixodes cookei) were found feeding concurrently on these hosts. Haemaphysalis longicornis was found in the highest proportions compared with other native tick species on raccoons (55.4%), Virginia opossums (28.9%), and white-tailed deer (11.5%). Tissue, blood, and engorged larvae were tested for 17 different pathogens using a nanoscale PCR platform. Infection with five pathogens (Borrelia burgdorferi, Anaplasma phagocytophilum, Rickettsia spp., Mycoplasma haemocanis, and Bartonella spp.) was detected in host samples, but no pathogens were found in any larval samples. These results suggest that although large and medium sized mammals feed large numbers of H. longicornis ticks in the environment, there is presently a low potential for H. longicornis to acquire pathogens from these wildlife hosts. 相似文献
52.
Castañeda-Pérez Eduardo Jiménez-Morales Karina Castellanos-Ruelas Arturo Chel-Guerrero Luis Betancur-Ancona David 《International journal of peptide research and therapeutics》2021,27(3):1979-1988
International Journal of Peptide Research and Therapeutics - Characterized by uncontrolled, long-term high blood sugar levels, diabetes mellitus affects ever increasing numbers of people worldwide.... 相似文献
53.
Ocadiz-Delgado Rodolfo Cruz-Colin Jose-Luis Alvarez-Rios Elizabeth Torres-Carrillo Antonio Hernandez-Mendoza Karina Conde-Pérezprina Juan-Cristobal Dominguez-Gomez Guadalupe-Isabel Garcia-Villa Enrique Lambert Paul F. Gariglio Patricio 《Journal of physiology and biochemistry》2021,77(4):547-555
Journal of Physiology and Biochemistry - The high-risk human papillomavirus (HR-HPV) E7 oncoprotein appears to be a major determinant for cell immortalization and transformation altering critical... 相似文献
54.
Anna Michalik Teresa Szklarzewicz Piotr Wegierek Karina Wieczorek 《Invertebrate Biology》2013,132(3):226-240
The ovaries of aphids belonging to the families Eriosomatidae, Anoeciidae, Drepanosiphidae, Thelaxidae, Aphididae, and Lachnidae were examined at the ultrastructural level. The ovaries of these aphids are composed of several telotrophic ovarioles. The individual ovariole is differentiated into a terminal filament, tropharium, vitellarium, and pedicel (ovariolar stalk). Terminal filaments of all ovarioles join together into the suspensory ligament, which attaches the ovary to the lobe of the fat body. The tropharium houses individual trophocytes and early previtellogenic oocytes termed arrested oocytes. Trophocytes are connected with the central part of the tropharium, the trophic core, by means of broad cytoplasmic processes. One or more oocytes develop in the vitellarium. Oocytes are surrounded by a single layer of follicular cells, which do not diversify into distinct subpopulations. The general organization of the ovaries in oviparous females is similar to that of the ovaries in viviparous females, but there are significant differences in their functioning: (1) in viviparous females, all ovarioles develop, whereas in oviparous females, some of them degenerate; (2) the number of germ cells per ovariole is usually greater in females of the oviparous generation than in females of viviparous generations; (3) in oviparous females, oocytes in the vitellarium develop through three stages (previtellogenesis, vitellogenesis, and choriogenesis), whereas in viviparous females, the development of oocytes stops after previtellogenesis; and (4) in the oocyte cytoplasm of oviparous females, lipid droplets and yolk granules accumulate, whereas in viviparous females, oocytes accrue only lipid droplets. Our results indicate that a large number of germ cells per ovariole represent the ancestral state within aphids. This trait may be helpful in inferring the phylogeny of Aphidoidea. 相似文献
55.
Assembly of the Escherichia coli 30S ribosomal subunits proceeds through multiple parallel pathways. The protein factors RimM, YjeQ, RbfA, and Era work in conjunction to assist at the late stages of the maturation process of the small subunit. However, it is unclear how the functional interplay between these factors occurs in the context of multiple parallel pathways. To understand how these factors work together, we have characterized the immature 30S subunits that accumulate in ΔrimM cells and compared them with immature 30S subunits from a ΔyjeQ strain. The cryo-EM maps obtained from these particles showed that the densities representing helices 44 and 45 in the rRNA were partially missing, suggesting mobility of these motifs. These 30S subunits were also partially depleted in all tertiary ribosomal proteins, particularly those binding in the head domain. Using image classification, we identified four subpopulations of ΔrimM immature 30S subunits differing in the amount of missing density for helices 44 and 45, as well as the amount of density existing in these maps for the underrepresented proteins. The structural defects found in these immature subunits resembled those of the 30S subunits that accumulate in the ΔyjeQ strain. These findings are consistent with an “early convergency model” in which multiple parallel assembly pathways of the 30S subunit converge into a late assembly intermediate, as opposed to the mature state. Functionally related factors will bind to this intermediate to catalyze the last steps of maturation leading to the mature 30S subunit. 相似文献
56.
Karina Motta Melo Ingrid Reale Alves Julio Cesar Pieczarka José Augusto de Oliveira David Cleusa Yoshiko Nagamachi Cesar Koppe Grisolia 《Genetics and molecular biology》2013,36(3):425-429
The frequency of spontaneous micronucleus (MN) formation in fish species needs to be determined to evaluate their usefulness for genotoxic biomonitoring. The definition of a good bioindicator takes into account the current knowledge of its metabolic traits as well as other factors including its feeding behavior and relationship to the environment. In this study, we compared the basal frequencies of micronucleated erythrocytes and nuclear abnormalities (NA) among different species of the fish Order Gymnotiformes (Rhamphichthys marmoratus, Steatogenys elegans, Sternopygus macrurus, Parapteronotus hasemani, Gymnotus mamiraua, Gymnotus arapaima, Brachyhypopomus beebei, Brachyhypopomus n. sp. BENN) sampled in several localities of the Eastern Amazon. A baseline of MN and NA frequency in these fish was determined, enabling the identification of potentially useful species as models for genotoxicity studies. Only one impacted sample collected at a site in the River Caripetuba showed a significant number of NAs, which may be due to the release of wastewater by neighbouring mining industries and by the burnt fuel released by the small boats used by a local community. Our results may provide support for further studies in areas of the Eastern Amazon affected by mining, deforestation and other anthropogenic activities. 相似文献
57.
Jere E. Meredith Jr. Sethu Sankaranarayanan Valerie Guss Anthony J. Lanzetti Flora Berisha Robert J. Neely J. Randall Slemmon Erik Portelius Henrik Zetterberg Kaj Blennow Holly Soares Michael Ahlijanian Charles F. Albright 《PloS one》2013,8(10)
Cerebral spinal fluid (CSF) Aβ42, tau and p181tau are widely accepted biomarkers of Alzheimer’s disease (AD). Numerous studies show that CSF tau and p181tau levels are elevated in mild-to-moderate AD compared to age-matched controls. In addition, these increases might predict preclinical AD in cognitively normal elderly. Despite their importance as biomarkers, the molecular nature of CSF tau and ptau is not known. In the current study, reverse-phase high performance liquid chromatography was used to enrich and concentrate tau prior to western-blot analysis. Multiple N-terminal and mid-domain fragments of tau were detected in pooled CSF with apparent sizes ranging from <20 kDa to ~40 kDa. The pattern of tau fragments in AD and control samples were similar. In contrast, full-length tau and C-terminal-containing fragments were not detected. To quantify levels, five tau ELISAs and three ptau ELISAs were developed to detect different overlapping regions of the protein. The discriminatory potential of each assay was determined using 20 AD and 20 age-matched control CSF samples. Of the tau ELISAs, the two assays specific for tau containing N-terminal sequences, amino acids 9-198 (numbering based on tau 441) and 9-163, exhibited the most significant differences between AD and control samples. In contrast, CSF tau was not detected with an ELISA specific for a more C-terminal region (amino acids 159-335). Significant discrimination was also observed with ptau assays measuring amino acids 159-p181 and 159-p231. Interestingly, the discriminatory potential of p181 was reduced when measured in the context of tau species containing amino acids 9-p181. Taken together, these results demonstrate that tau in CSF occurs as a series of fragments and that discrimination of AD from control is dependent on the subset of tau species measured. These assays provide novel tools to investigate CSF tau and ptau as biomarkers for other neurodegenerative diseases. 相似文献
58.
Meredith Mealer John Kittelson B. Taylor Thompson Arthur P. Wheeler John C. Magee Ronald J. Sokol Marc Moss Michael G. Kahn 《PloS one》2013,8(12)
Objective
Barriers to executing large-scale randomized controlled trials include costs, complexity, and regulatory requirements. We hypothesized that source document verification (SDV) via remote electronic monitoring is feasible.Methods
Five hospitals from two NIH sponsored networks provided remote electronic access to study monitors. We evaluated pre-visit remote SDV compared to traditional on-site SDV using a randomized convenience sample of all study subjects due for a monitoring visit. The number of data values verified and the time to perform remote and on-site SDV was collected.Results
Thirty-two study subjects were randomized to either remote SDV (N=16) or traditional on-site SDV (N=16). Technical capabilities, remote access policies and regulatory requirements varied widely across sites. In the adult network, only 14 of 2965 data values (0.47%) could not be located remotely. In the traditional on-site SDV arm, 3 of 2608 data values (0.12%) required coordinator help. In the pediatric network, all 198 data values in the remote SDV arm and all 183 data values in the on-site SDV arm were located. Although not statistically significant there was a consistent trend for more time consumed per data value (minutes +/- SD): Adult 0.50 +/- 0.17 min vs. 0.39 +/- 0.10 min (two-tailed t-test p=0.11); Pediatric 0.99 +/- 1.07 min vs. 0.56 +/- 0.61 min (p=0.37) and time per case report form: Adult: 4.60 +/- 1.42 min vs. 3.60 +/- 0.96 min (p=0.10); Pediatric: 11.64 +/- 7.54 min vs. 6.07 +/- 3.18 min (p=0.10) using remote SDV.Conclusions
Because each site had different policies, requirements, and technologies, a common approach to assimilating monitors into the access management system could not be implemented. Despite substantial technology differences, more than 99% of data values were successfully monitored remotely. This pilot study demonstrates the feasibility of remote monitoring and the need to develop consistent access policies for remote study monitoring. 相似文献59.
Petronella Anbeek Ivana I?gum Britt J. M. van Kooij Christian P. Mol Karina J. Kersbergen Floris Groenendaal Max A. Viergever Linda S. de Vries Manon J. N. L. Benders 《PloS one》2013,8(12)
Purpose
Volumetric measurements of neonatal brain tissues may be used as a biomarker for later neurodevelopmental outcome. We propose an automatic method for probabilistic brain segmentation in neonatal MRIs.Materials and Methods
In an IRB-approved study axial T1- and T2-weighted MR images were acquired at term-equivalent age for a preterm cohort of 108 neonates. A method for automatic probabilistic segmentation of the images into eight cerebral tissue classes was developed: cortical and central grey matter, unmyelinated and myelinated white matter, cerebrospinal fluid in the ventricles and in the extra cerebral space, brainstem and cerebellum. Segmentation is based on supervised pixel classification using intensity values and spatial positions of the image voxels. The method was trained and evaluated using leave-one-out experiments on seven images, for which an expert had set a reference standard manually. Subsequently, the method was applied to the remaining 101 scans, and the resulting segmentations were evaluated visually by three experts. Finally, volumes of the eight segmented tissue classes were determined for each patient.Results
The Dice similarity coefficients of the segmented tissue classes, except myelinated white matter, ranged from 0.75 to 0.92. Myelinated white matter was difficult to segment and the achieved Dice coefficient was 0.47. Visual analysis of the results demonstrated accurate segmentations of the eight tissue classes. The probabilistic segmentation method produced volumes that compared favorably with the reference standard.Conclusion
The proposed method provides accurate segmentation of neonatal brain MR images into all given tissue classes, except myelinated white matter. This is the one of the first methods that distinguishes cerebrospinal fluid in the ventricles from cerebrospinal fluid in the extracerebral space. This method might be helpful in predicting neurodevelopmental outcome and useful for evaluating neuroprotective clinical trials in neonates. 相似文献60.
Fabio E. Leal Lishomwa C. Ndhlovu Aaron M. Hasenkrug Fernanda R. Bruno Karina I. Carvalho Harry Wynn-Williams Walter K. Neto Sabri S. Sanabani Aluisio C. Segurado Douglas F. Nixon Esper G. Kallas 《PLoS neglected tropical diseases》2013,7(2)
HTLV-1 infection is associated with several inflammatory disorders, including the neurodegenerative condition HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). It is unclear why a minority of infected subjects develops HAM/TSP. CD4+ T cells are the main target of infection and play a pivotal role in regulating immunity to HTLV and are hypothesized to participate in the pathogenesis of HAM/TSP. The CD39 ectonucleotidase receptor is expressed on CD4+ T cells and based on co-expression with CD25, marks T cells with distinct regulatory (CD39+CD25+) and effector (CD39+CD25−) function. Here, we investigated the expression of CD39 on CD4+ T cells from a cohort of HAM/TSP patients, HTLV-1 asymptomatic carriers (AC), and matched uninfected controls. The frequency of CD39+ CD4+ T cells was increased in HTLV-1 infected patients, regardless of clinical status. More importantly, the proportion of the immunostimulatory CD39+CD25− CD4+ T-cell subset was significantly elevated in HAM/TSP patients as compared to AC and phenotypically had lower levels of the immunoinhibitory receptor, PD-1. We saw no difference in the frequency of CD39+CD25+ regulatory (Treg) cells between AC and HAM/TSP patients. However, these cells transition from being anergic to displaying a polyfunctional cytokine response following HTLV-1 infection. CD39−CD25+ T cell subsets predominantly secreted the inflammatory cytokine IL-17. We found that HAM/TSP patients had significantly fewer numbers of IL-17 secreting CD4+ T cells compared to uninfected controls. Taken together, we show that the expression of CD39 is upregulated on CD4+ T cells HAM/TSP patients. This upregulation may play a role in the development of the proinflammatory milieu through pathways both distinct and separate among the different CD39 T cell subsets. CD39 upregulation may therefore serve as a surrogate diagnostic marker of progression and could potentially be a target for interventions to reduce the development of HAM/TSP. 相似文献