101 research outputs found

    A New Endemic Focus of Chagas Disease in the Northern Region of Veraguas Province, Western Half Panama, Central America

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    Background: Chagas disease was originally reported in Panama in 1931. Currently, the best knowledge of this zoonosis is restricted to studies done in historically endemic regions. However, little is known about the distribution and epidemiology of Chagas disease in other rural areas of the country. Methods and Findings: A cross-sectional descriptive study was carried out between May 2005 – July 2008 in four rural communities of the Santa Fe District, Veraguas Province. The study included an entomologic search to collect triatomines, bloodmeal type identification and infection rate with trypanosomes in collected vectors using a dot- blot and PCR analysis, genotyping of circulating Trypanosoma cruzi (mini-exon gene PCR analysis) and the detection of chagasic antibodies among inhabitants. The vector Rhodnius pallescens was more frequently found in La Culaca and El Pantano communities (788 specimens), where it was a sporadic household visitor. These triatomines presented darker coloration and larger sizescompared with typical specimens collected in Central Panama. Triatoma dimidiata was more common in Sabaneta de El Macho (162 specimens). In one small sub-region (El Macho), 60 % of the houses were colonized by this vector. Of the examined R. pallescens, 54.7.0 % (88/161) had fed on Didelphis marsupialis, and 24.6 % (34/138) of T. dimidiata specimens collected inside houses were positive for human blood. R. pallescens presented an infection index with T. cruzi of 17.7 % (24/ 136), with T. rangeli of 12.5 % (17/136) and 50.7 % (69/136) were mixed infections. In 117 T. dimidiata domestic specimens th

    Acute graft versus host disease

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    Acute graft-versus-host disease (GVHD) occurs after allogeneic hematopoietic stem cell transplant and is a reaction of donor immune cells against host tissues. Activated donor T cells damage host epithelial cells after an inflammatory cascade that begins with the preparative regimen. About 35%–50% of hematopoietic stem cell transplant (HSCT) recipients will develop acute GVHD. The exact risk is dependent on the stem cell source, age of the patient, conditioning, and GVHD prophylaxis used. Given the number of transplants performed, we can expect about 5500 patients/year to develop acute GVHD. Patients can have involvement of three organs: skin (rash/dermatitis), liver (hepatitis/jaundice), and gastrointestinal tract (abdominal pain/diarrhea). One or more organs may be involved. GVHD is a clinical diagnosis that may be supported with appropriate biopsies. The reason to pursue a tissue biopsy is to help differentiate from other diagnoses which may mimic GVHD, such as viral infection (hepatitis, colitis) or drug reaction (causing skin rash). Acute GVHD is staged and graded (grade 0-IV) by the number and extent of organ involvement. Patients with grade III/IV acute GVHD tend to have a poor outcome. Generally the patient is treated by optimizing their immunosuppression and adding methylprednisolone. About 50% of patients will have a solid response to methylprednisolone. If patients progress after 3 days or are not improved after 7 days, they will get salvage (second-line) immunosuppressive therapy for which there is currently no standard-of-care. Well-organized clinical trials are imperative to better define second-line therapies for this disease. Additional management issues are attention to wound infections in skin GVHD and fluid/nutrition management in gastrointestinal GVHD. About 50% of patients with acute GVHD will eventually have manifestations of chronic GVHD

    Mesenchymal stem cell therapy and acute graft-versus-host disease: a review

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    Clinical impact of the loss of chromosome 7q on outcomes of patients with myelodysplastic syndromes treated with allogeneic hematopoietic stem cell transplantation

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    We conducted a nationwide retrospective study to evaluate the prognostic influence of +1, der(1;7)(q10;p10) [hereafter der(1;7)] and ?7/del(7q) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for de novo myelodysplastic syndromes (MDS). In this database, 69 MDS patients with der(1;7), 75 with ?7/del(7q), and 511 with normal karyotype (NK) underwent allo-HSCT at advanced disease status. The 3-year overall survival (OS) and cumulative incidence of relapse (CIR) were 50.4 and 19.4% for those with der(1;7), 36.2 and 38.4% for ?7/del(7q),and 51.1 and 20.7% for NK, respectively. In the multivariate analysis, the presence of ?7/del(7q) correlated with a significantly shorter OS (HR [95% CI], 1.38 [1.00?1.89]; P = 0.048) and higher CIR (HR, 2.11 [1.36?3.28]; P = 0.001) than those with NK. There were 23 patients with der(1;7), 29 with ?7/del(7q), and 347 with NK who underwent allo-HSCT at early disease status.The 3-year OS and CIR were as follows: 47.3 and 9.5% for the der(1;7) group, 70.5 and 13.8% for ?7/del(7q), and 70.9 and 5.6% for NK,respectively. No significant differences were observed in OS and CIR among three groups. The impact of the loss of chromosome 7q on OS and CIR may differ based on its type and disease status after allo-HSCT for MDS

    A dynamic homogenization approach for modelling hybrid piezoelectric nanogenerators

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    Energy scavenging, from green and sustainable energy resources, is increasingly attracting the atten- tion of researchers and industries in several engineering fields. The main aim is capturing the energy, naturally available in the environment, and converting it into electrical energy. Emerging applica- tions, such as in flexible/strechable micro and nano electronics, biomedical monitoring, wearable technology, micro and nano robotics and extreme technology, require devices of smaller and smaller size and high performances

    Editorial: Cutting-Edge Metastructures: Micro-Architected and Active Metamaterials

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    The present Research Topic collects articles dealing with the optimal design, the realization and the testing of meta-structures capable of achieving dynamic high-performance. The common thread linking these articles is using metamaterials concepts to conceive intriguing internal architecture for wave propagation control. Due to their interdisciplinary nature and their broad range of applications, metamaterials have increasingly inspired researchers of different communities. In the last years, mathematicians, physicists, engineers, and material scientists have mobilized massive effort to move the limits beyond state-of-the-art to realize extreme materials. Charming behaviors such as filtering, wave-guiding, negative refraction, cloaking, seismic protection, noise reduction and band-gap control have been demonstrated to be possible theoretically, via numerical simulations and by real experiments. Different techniques have been developed for achieving such exotic effects. A non-exhaustive list of these includes i) mass, inertia and stiffness modifications, ii) the use of local inertial or Helmholtz resonators or gyroscopes elements embedded into lattice or continuum materials, iii) the use of a multi-field electro-mechanical coupling via piezoelectric active phases. Within this framework, the current research topics of the articles provide a new perspective for using the metamaterial idea to achieve phenomena such as cloaking, seismic protection, dynamic wave propagation attenuation, and wave localization
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