Intestinal homeostasis is maintained by the response of gut-associated lymphoid tissue to bacteria transported across the follicle associated epithelium into the subepithelial dome. The initial response to antigens and how bacteria are handled is incompletely understood. By iterative application of spatial transcriptomics and multiplexed single-cell technologies, we identify that the double negative 2 subset of B cells, previously associated with autoimmune diseases, is present in the subepithelial dome in health.
View Article and Find Full Text PDFConfirmed SARS-coronavirus-2 infection with gastrointestinal symptoms and changes in microbiota associated with coronavirus disease 2019 (COVID-19) severity have been previously reported, but the disease impact on the architecture and cellularity of ileal Peyer's patches (PP) remains unknown. Here we analysed tissues from throughout the gastrointestinal (GI) tract of patients who died with COVID-19. When virus was detected by PCR in the GI tract, immunohistochemistry identified virus in epithelium and lamina propria macrophages, but not in lymphoid tissues.
View Article and Find Full Text PDFMass cytometry is a variation of conventional flow cytometry using metal tagged antibodies for cell staining instead of fluorochromes and detection in a mass cytometer, a modified mass spectrometer that allows for separation of discrete masses of these metal tags by time of flight (TOF). Currently, up to 50 different metal tags are available for cell analysis. The lack of any significant mass spectral overlap and autofluorescence background makes mass cytometry uniquely suited for complex high-dimensional phenotypic and functional analysis at the single cell level, thus accelerating biomarker discovery and drug screening.
View Article and Find Full Text PDFThe neutrophil enzyme, myeloperoxidase, by converting hydrogen peroxide (HO) and chloride to hypochlorous acid (HOCl), provides important defense against ingested micro-organisms. However, there is debate about how efficiently HOCl is produced within the phagosome and whether its reactions with phagosomal constituents influence the killing mechanism. The phagosome is a small space surrounding the ingested organism, into which superoxide, HO and high concentrations of proteins from cytoplasmic granules are released.
View Article and Find Full Text PDFPerioper Med (Lond)
August 2017
Background: In 2014, this group published an investigation of surgical patients from 2012 who had substantial rates of postoperative hypoxemia (POH) and perioperative pulmonary aspiration (POPA). Therefore, we investigated whether intraoperative reverse Trendelenburg positioning (RTP) decreases POH and POPA rates.
Methods: Consecutive ASA I-IV surgical patients who had preoperative pulmonary stability requiring general anesthesia with endotracheal intubation were evaluated.
A key aspect to finding an efficacious human immunodeficiency virus (HIV) vaccine is the optimization of vaccine schedules that can mediate the efficient maturation of protective immune responses. In the present study, we investigated the effect of alternate booster regimens on the immune responses to a candidate HIV-1 clade C CN54gp140 envelope protein, which was coadministered with the TLR4-agonist glucopyranosyl lipid A-aqueous formulation. Twelve study participants received a common three-dose intramuscular priming series followed by a final booster at either 6 or 12 months.
View Article and Find Full Text PDFUnlabelled: Gonorrhea is a sexually transmitted disease causing growing concern, with a substantial increase in reported incidence over the past few years in the United Kingdom and rising levels of resistance to a wide range of antibiotics. Understanding its epidemiology is therefore of major biomedical importance, not only on a population scale but also at the level of direct transmission. However, the molecular typing techniques traditionally used for gonorrhea infections do not provide sufficient resolution to investigate such fine-scale patterns.
View Article and Find Full Text PDFNursing homes represent a unique and important methicillin-resistant Staphylococcus aureus (MRSA) reservoir. Not only are strains imported from hospitals and the community, strains can be transported back into these settings from nursing homes. Since MRSA bacteria are prevalent in nursing homes and yet relatively poorly studied in this setting, a multicenter, regional assessment of the frequency and diversity of MRSA in the nursing home reservoir was carried out and compared to that of the MRSA from hospitals in the same region.
View Article and Find Full Text PDFBackground: Vaccination against 7 serotypes of Streptococcus pneumoniae has led to the near extinction of vaccine serotypes in both disease and asymptomatic carriage. In carriage, vaccine serotypes have been replaced by nonvaccine serotypes.
Methods: We used multilocus sequence typing to analyze a sample of 294 isolates of S.
Infusion nurses are uniquely positioned to play a vital role in the early identification and management of infusion and hypersensitivity reactions during the administration of biologic therapies. This article reviews the current evidence regarding reactions related to the administration of monoclonal antibodies, namely, natalizumab, a humanized monoclonal antibody against the cellular adhesion molecule alpha4-integrin, in patients with multiple sclerosis. In addition to differentiating between infusion and hypersensitivity reactions, the article presents general guidelines for the management of these reactions and provides case studies to better illustrate the use of appropriate interventions.
View Article and Find Full Text PDFBackground: Methods for assigning strains to bacterial species are cumbersome and no longer fit for purpose. The concatenated sequences of multiple house-keeping genes have been shown to be able to define and circumscribe bacterial species as sequence clusters. The advantage of this approach (multilocus sequence analysis; MLSA) is that, for any group of related species, a strain database can be produced and combined with software that allows query strains to be assigned to species via the internet.
View Article and Find Full Text PDFBackground: Pilus components of Streptococcus pneumoniae encoded by rlrA were recently shown to elicit protection in an animal model of infection. Limited data are available on the prevalence of the rlrA operon in pneumococci; therefore, we investigated its distribution and its antigenic variation among disease-causing strains.
Methods: The prevalence of rlrA and its association with serotype and genotype were evaluated in a global panel of 424 pneumococci isolates (including the 26 drug-resistant clones described by the Pneumococcal Molecular Epidemiology Network).
Background: Gonorrhoea is an important cause of sexual ill health and is concentrated in geographical areas and demographic groups. This study explores the distribution of gonorrhoea across London.
Methods: Epidemiological data on all gonorrhoea cases were collected from 13 major genitourinary clinics in London between 1 June and 30 November 2004.
Background: In response to the selective pressure of pneumococcal conjugate vaccine, increased asymptomatic carriage of antibiotic-nonsusceptible nonvaccine serotypes (NVTs) has been observed. Possible mechanisms include de novo acquisition of resistance, serotype switching, introduction of new clones, and expansion of existing clones.
Methods: To investigate the process of increased antibiotic nonsusceptibility among replacing serotypes, we applied multilocus sequence typing to samples of 126 and 222 pneumococci collected in 2001 and 2004, respectively, from the nasopharynges of children <7 years of age in 16 Massachusetts communities.
Background: Molecular typing of Neisseria gonorrhoeae and contact tracing provide a combined approach for analysis of sexual networks in metropolitan areas, although there are some difficulties in application. Our aim was to examine the application of high-throughput molecular approaches that can identify individuals in linked sexual networks.
Methods: We characterised 2045 isolates of N gonorrhoeae from patients presenting at 13 major sexually transmitted infection clinics in London, UK, between June 1 and Nov 30, 2004.
Free Radic Biol Med
December 2005
We describe a new assay for the chlorination activity of myeloperoxidase and detection of chloramines. Chloramines were detected by using iodide to catalyze the oxidation of either 3,3',5,5'-tetramethylbenzidine (TMB) or dihydrorhodamine to form strongly absorbing or fluorescent products, respectively. With TMB as little as 1 muM taurine chloramine could be detected.
View Article and Find Full Text PDFThe small animal practitioner is likely to be called upon to help nontraditional pets such as rabbits, rodents, and ferrets. The more information veterinarians have regarding normal anatomy, physiology, reproduction, medicine, anesthesia, and surgery of these unusual pets, the more likely they will be able to help their owners. This article presents an overview of routine and emergency reproductive concerns that the small animal practitioner may face when presented with nontraditional mammalian patients.
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