541 research outputs found

    Murine Typhus in Child, Yucatan, Mexico

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    A case of murine typhus in Yucatan was diagnosed in a child with nonspecific signs and symptoms. The finding of Rickettsia typhi increases the number of Rickettsia species identified in Yucatan and shows that studies are needed to determine the prevalence and incidence of rickettsioses in Mexico

    Direct evidence of Rickettsia typhi infection in Rhipicephalus sanguineus ticks and their canine hosts

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    Murine typhus is a rickettsiosis caused by Rickettsia typhi, whose transmission is carried out by rat fleas in urban settlements as classically known, but it also has been related to cat fleas in a sub-urban alternative cycle that has been suggested by recent reports. These studies remarks that in addition to rats, other animals like cats, opossums and dogs could be implied in the transmission of Rickettsia typhi as infected fleas obtained from serologically positive animals have been detected in samples from endemic areas. In Mexico, the higher number of murine typhus cases have been detected in the Yucatan peninsula, which includes a great southeastern region of Mexico that shows ecologic characteristics similar to the sub-urban alternative cycle recently described in Texas and California at the United States. To find out which are the particular ecologic characteristics of murine typhus transmission in this region, we analyzed blood and Rhipicephalus sanguineus ticks obtained from domestic dogs by molecular approaches, demonstrating that both samples were infected by Rickettsia typhi. Following this, we obtained isolates that were analyzed by genetic sequencing to corroborate this infection in 100% of the analyzed samples. This evidence suggests for the first time that ticks and dogs could be actively participating in the transmission of murine typhus, in a role that requires further studies for its precise description.Keywords: Dogs, Murine typhus, Rhipicephalus sanguineus, Rickettsia typhi, Vecto

    First histopathological study in kidneys of rodents naturally infected with Leptospira pathogenic species from Yucatan, Mexico

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    AbstractObjectiveTo report the renal histological lesions in synanthropic rodents, Mus musculus and Rattus rattus, naturally infected with Leptospira spp., captured in a rural community in Yucatan, Mexico.MethodsKidney samples of synanthropic rodents were collected from a rural community in Yucatan, Mexico. Polymerase chain reaction was used to detect Leptospira spp. infection. Tissue kidney was fixed in 10% buffered formalin, processed according to the usual techniques for paraffin inclusion, cut and stained with hematoxylin and eosin, and examined using a conventional electronic microscope.ResultsA total of 187 rodents were captured. Nine individuals (4.8%) were positive for Leptospira spp. in the molecular analysis. All renal lesions observed in the histopathological study had been reported previously for Leptospira spp. infection.ConclusionsThe histopathological lesions are present in the kidneys, plus the results of the polymerase chain reaction confirm that these rodents are true carriers of Leptospira spp

    Fatal Human Infection with Rickettsia rickettsii, Yucatán, Mexico

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    The first fatal Rickettsia rickettsii infection was diagnosed in the southwest of Mexico. The patient had fever, erythematous rash, abdominal pain, and severe central nervous system involvement with convulsive crisis. The diagnosis of R. rickettsii infection was established by immunohistochemistry and specific polymerase chain reaction

    La prescripcion como modo de extinguir las obligaciones tributarias en Chile. Analisis general y de los supuestos por los cuales se amplia su aplicacion desde su forma ordinaria a su forma extraordinaria

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    52 p.El Derecho Tributario es una de las ramas más complejas del Ordenamiento Jurídico, por sus normas, eminentemente técnicas y porque algunos pasajes de la ley son poco claros o imprecisos al establecer que ciertas circunstancias conllevan una consecuencia jurídica determinada. Esta investigación trata sobre la institución de la prescripción en materia tributaria. Además de realizar un análisis general, resolveremos ciertos aspectos controvertidos referentes a la forma en que se computan los plazos de prescripción, así como definiremos qué se debe entender como declaración no presentada o maliciosamente falsa, para efectos del aumento del plazo de prescripción aplicable a un contribuyente, desde su forma ordinaria a su forma extraordinaria. Como sustento teórico, utilizaremos tanto la postura doctrinaria sobre la materia, así como también la de los Tribunales Superiores de Justicia y la de los entes administrativos, contrastada con lo que el legislador dispuso en el Código Tributario y otros cuerpos legales./ ABSTRACT Tax law is one of the most complex branches Legal System, since its rules are very technical nature and because the Legislature in some passages of the law is unclear or vague to defining parameters for establishing certain circumstances involving a Legal Consequence determined. This research is about the institution of the Extinctive Prescription in Tax Matters. In addition to general analysis, we will solve some of the controversy concerning the way in which computing the prescription periods, and also define what should be understood as a declaration not filed or maliciously false, effects of increased within limitations applicable to a taxpayer, their way from ordinary to extraordinary. Theoretical support, we will use both the doctrinal position on the matter, as well as the Higher Courts and the Administrative, contrasted with what the Legislature decided in the Tax Code and other Legislation

    Latinamerican guidelines of RIICER for diagnosis of tick-borne rickettsioses

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    Las rickettsiosis transmitidas por garrapatas son afecciones de distribución mundial, que por diferentes motivos se pueden considerar emergentes y reemergentes. Hasta hace escasos años la única rickettsiosis transmitida por garrapatas en Latinoamérica era la infección por Rickettsia rickettsii, pero en la actualidad y fundamentalmente, gracias a la incorporación de nuevas herramientas para el diagnóstico microbiológico como la reacción en cadena de la polimerasa y secuenciación o el cultivo celular rápido en tubo cerrado, se han descrito e involucrado otras especies de Rickettsia en la producción de patología humana. En estas guías se detallan y describen las diferentes técnicas utilizadas para el diagnóstico microbiológico de las rickettsiosis. Además, se incluye una sección en la que se detallan las especies más importantes de garrapatas duras relacionadas con las rickettsiosis en Latinoamérica, con claves para su clasificación taxonómica.Tick-borne rickettsioses are worldwide infectious diseases that are considered emerging and re-emerging. Until recently the only tick-borne rickettsiosis present in Latin America was Rickettsia rickettsii infection, but to date, with the incorporation of new tools as PCR and sequencing and the quick cellular close tube cultures (Shell-vial), new species has been involved as human pathogens. In these guidelines, we offer an update of the microbiological assays for diagnosing rickettsioses. Besides we have included a section in which the most important hard ticks involved in human rickettsioses in Latinoamerica are detailed.Financiamiento: RIICER (Red Iberoamericana para la Investigación y Control de las Enfermedades Rickettsiales) del Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo (CYTED)

    Učinak postupnog blanširanja u otopini kalcijeva klorida na teksturu i strukturu ukiseljenih „jalapeño” paprika

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    Jalapeño peppers incur texture changes during thermal processing due to loss of turgor pressure, tissue softening, and pectin solubility in the cell wall, which affects their quality and acceptability as a processed product among consumers. The objective of this work is to evaluate the effect of stepwise blanching with calcium chloride solution on firmness, calcium absorption and microstructural changes of jalapeño peppers. Batches of 1 kg of pepper halves were blanched at 65 °C for 4 min at different concentrations of CaCl2 (0, 0.075, 0.15 and 0.3 mol/L). After blanching, the peppers were removed, placed in plastic bags and submerged in a water bath at 65 °C for different holding times (0, 15, 30 and 45 min). Then the peppers were blanched again in an acidified solution at 96 °C for 3 min to remove enzymatic activity. Afterwards, peppers were packed in glass containers with brine at 95 °C and pasteurized at 85 °C for 10 min. The product was stored for 10 days at room temperature, then analyzed for texture, calcium absorption, pH, acidity, and microstructural changes. Results showed that CaCl2 concentration and blanching improved firmness with a maximum value of 3.68 N, a 4.3-fold increase over control. Calcium absorption increased with CaCl2 concentration reaching a maximum of 0.68 g of Ca2+ per kg of samples. Microscopy showed reduced cell wall damage in the samples that were blanched in 0.3 mol/L of CaCl2 at 45 min of holding time. The optimum processing conditions determined in thisstudy can be used for improving the firmness of peppers.Tijekom toplinske obrade mijenja se tekstura „jalapeño” paprika zbog gubitka turgora, mekšanja tkiva i topljivosti pektina u staničnim stijenkama, što utječe na njihovu kakvoću i prihvatljivost među potrošačima. Svrha je ovoga rada bila procijeniti učinak postupnog blanširanja u otopini kalcijeva klorida na čvrstoću tkiva, apsorpciju kalcija i mikrostrukturalne promjene „jalapeño” paprika. Šarže od 1 kg polovica paprika blanširane su 4 minute na 65 °C pri različitim koncentracijama CaCl2 (0; 0,075; 0,15 i 0,3 mol/L). Nakon blanširanja paprike su stavljene u plastične vrećice i potopljene u vodenu kupelj na 65 °C tijekom 0, 15, 30 i 45 min. Zatim su radi inaktivacije enzima 3 minute blanširane u zakiseljenoj otopini pri 96 °C, te pakirane u staklenke s rasolom (pri 95 °C) i pasterizirane na 85 °C tijekom 10 min. Naposljetku su 10 dana skladištene na sobnoj temperaturi, nakon čega je analizirana njihova tekstura, apsorpcija kalcija, pH, kiselost i mikrostrukturalne promjene. Rezultati pokazuju da CaCl2 i blanširanje poboljšavaju čvrstoću tkiva 4,3 puta (na maksimalnih 3,68 N), u usporedbi s kontrolnim uzorkom. Povećanjem koncentracije CaCl2 povećala se apsorpcija kalcija (maksimalno 0,68 g Ca2+/kg paprika). U uzorcima blanširanim 45 min u otopini CaCl2, koncentracije 0,3 mol/L, mikroskopski je utvrđeno manje oštećenje staničnih stijenki. Stoga je zaključeno da se čvrstoća paprika može poboljšati optimiranjem uvjeta prerade
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