50 research outputs found

    The Potential for a Blood Test for Scabies

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    Scabies, caused by the mite S. scabiei that burrows in the skin of humans, is a contagious skin disease that affects millions of people worldwide. It is a significant public health burden in economically disadvantaged populations, and outbreaks are common in nursing homes, daycare facilities, schools and workplaces in developed countries. It causes significant morbidity, and in chronic cases, associated bacterial infections can lead to renal and cardiac diseases. Scabies is very difficult to diagnose by the usual skin scrape test, and a presumptive diagnosis is often made based on clinical signs such as rash and itch that can mimic other skin disease. A sensitive and specific blood test to detect scabies-specific antibodies would allow a physician to quickly make a correct diagnosis. Our manuscript reports the antibody isotype profiles of the sera of two groups of patients with ordinary scabies (17 from the US and 74 from Brazil) and concludes that such a blood test should be based on circulating IgM type antibodies that do not also recognize antigens of the related and ubiquitous house dust mites. Both are important considerations for research for developing a blood test for the diagnosis of scabies

    Structural Optimization and Thermal Modeling of Flux Switching Machine

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    The point of this study was to model a lumped parameter thermal network for flux switching machine. The model could be utilized to outline new cooling systems and as a developer for this sort of machines. The model developed is a thermal framework having segments essentially focused around existing literature. The losses in various machine sections were thought to have already found from the electromagnetic model. The elemental model can then be utilized to carry out simulations regarding cyclic loading as well as transient activities. The thermal model examined here is partitioned into different sectors, thereby empowering analysis of this machine. The model under investigation has been acknowledged by utilizing a COMSOL Multi-physics simulator and Matlab ® programming software. The heat exchange coefficients are characterized from information gathered from the comparative kind of machines. The developed framework also considers sensitivity analysis in terms of parametric effects on the behavior of the machine thermally. The developed model needs no substantial computing and can simply be run on a personal computer. The model can later be modified and connected to diverse machine developments. Structural topology optimization approach is adopted to find the optimal geometry. As a basic study, two optimization techniques i.e., genetic and simulated annealing algorithms have been adopted with the former based on the process of natural selection and the latter on the process of annealing (heating and cooling of metals). The design goal is to minimize the total dissipated losses to improve the overall efficiency and hence to achieve optimal design results

    Identification of Antigenic Sarcoptes scabiei Proteins for use in a Diagnostic Test and of Non-antigenic Proteins that may be Immunomodulatory

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    Background Scabies, caused by the mite, Sarcoptes scabiei, infects millions of humans, and many wild and domestic mammals. Scabies mites burrow in the lower stratum corneum of the epidermis of the skin and are the source of substances that are antigenic or modulate aspects of the protective response of the host. Ordinary scabies is a difficult disease to diagnose. Objective The goal of this project was to identify S. scabiei proteins that may be candidate antigens for use in a diagnostic test or may be used by the mite to modulate the host’s protective response. Methods An aqueous extract of S. scabiei was separated by 2-dimensional electrophoresis and proteins were identified by mass spectrometry. A parallel immunoblot was probed with serum from patients with ordinary scabies to identify IgM and/or IgG-binding antigens. The genes coding for 23 selected proteins were cloned into E. coli and the expressed recombinant proteins were screened with serum from patients with confirmed ordinary scabies. Results We identified 50 different proteins produced by S. scabiei, 34 of which were not previously identified, and determined that 66% were recognized by patient IgM and/or IgG. Fourteen proteins were screened for use in a diagnostic test but none possessed enough sensitivity and specificity to be useful. Six of the 9 proteins selected for the possibility that they may be immunomodulatory were not recognized by antibodies in patient serum. Conclusions Thirty-three proteins that bound IgM and/or IgG from the serum of patients with ordinary scabies were identified. None of the 14 tested were useful for inclusion in a diagnostic test. The identities of 16 proteins that are not recognized as antigens by infected patients were also determined. These could be among the molecules that are responsible for this mite’s ability to modulate its host’s innate and adaptive immune responses

    A review of Sarcoptes scabiei: past, present and future

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    Abstract The disease scabies is one of the earliest diseases of humans for which the cause was known. It is caused by the mite, Sarcoptes scabiei, that burrows in the epidermis of the skin of humans and many other mammals. This mite was previously known as Acarus scabiei DeGeer, 1778 before the genus Sarcoptes was established (Latreille 1802) and it became S. scabiei. Research during the last 40 years has tremendously increased insight into the mite’s biology, parasite-host interactions, and the mechanisms it uses to evade the host’s defenses. This review highlights some of the major advancements of our knowledge of the mite’s biology, genome, proteome, and immunomodulating abilities all of which provide a basis for control of the disease. Advances toward the development of a diagnostic blood test to detect a scabies infection and a vaccine to protect susceptible populations from becoming infected, or at least limiting the transmission of the disease, are also presented

    Response of Human Skin Equivalents to Sarcoptes scabiei

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    Enzymatic Activity in Extracts of Allergy-Causing Astigmatid Mites

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