RESUMO
The evaluation of the technical condition of historic buildings that have operated for several hundred years is a complicated issue. Even buildings that are in very poor condition must be checked and assessed in terms of their further repair, strengthening, or compliance with conditions that allow the facility to be safely operated. Most 18th-century buildings have not survived to this day retaining their original arrangements and structural elements. Renovations and repair work in the past were often carried out using materials of uncertain quality, with repair work of different qualities and without detailed analysis or methodology, based only on the experience of the former builders. In historic structures, the character of the work of individual structural elements has often changed due to significant material degradation, the poor quality of repair work, or the loss of adequate support. When load transfers change, internal forces are redistributed, and, as a result, the static scheme changes. This article presents an overview of identified defects affecting the change in static schemes in historical building structures built in the 18th century, using the example of a historic building with a large number of aforementioned defects. The process of assessing the technical condition of the facility is presented, in which non-destructive testing (NDT) methods were used. Detailed computational analyses were carried out for the wooden roof truss structure, which had partially lost its support.
RESUMO
The parasitic roundworm Trichinella spiralis is most commonly transmitted to humans through consumption of raw or undercooked meat of infected pigs or game. To prevent human infection, slaughterhouses perform meat safety surveillance using the gold standard "Magnetic Stirrer Method". We introduce a fast and objective method using automated detection of specific Trichinella spiralis antigens by a newly developed immunoassay based on chemiluminescence (ChLIA). Panel A comprised muscle tissue samples from non-infected pigs (n = 37). Panel B comprised muscle tissue samples from non-infected pigs spiked with different amounts of Trichinella larvae without collagen capsules (n = 56). Panel C contained muscle tissue samples from experimentally infected pigs including Trichinella larvae encapsulated in collagen (n = 32). Each sample was shredded with PBS buffer in a knife mill, destroying Trichinella larvae. Following centrifugation, the supernatant (muscle tissue extract containing released excretory and secretory Trichinella spiralis antigens) was used for Trichinella-specific antigen detection by the new Trichinella ChLIA. The overall accuracy of the Trichinella ChLIA was 97.6 %. The specificity of the Trichinella ChLIA was 100 % (panel A). The sensitivity in samples from experimentally infected pigs was 100 % representing a detection limit of 0.01 larvae per gram. Cross-reactivity with parasites other than Trichinella spp. was not observed. This new meat inspection method for the detection of Trichinella spiralis antigens presents high specificity and high sensitivity, especially in truly infected samples. In contrast to the gold standard, this new approach to meat safety surveillance does not require longsome digestion or microscopy by trained personnel.
RESUMO
Leucoproliferative Theileria parasites possess the unique capability to transform their bovine host cell, resulting in tumour-like characteristics like uncontrolled proliferation. The molecular mechanisms underlying this parasite-dependent process are only poorly understood. In the current study, bioinformatic analysis of the Theileria annulata surface protein (TaSP) from different T. annulata isolates identified a conserved CDK1 phosphorylation motif T131 PTK within the extracellular, polymorphic domain of TaSP. Phosphorylation assays with radioactively labelled ATP as well as ELISA-based experiments using a phospho-threonine-proline (pThr-Pro) antibody revealed, that CDK1-cyclin B specifically phosphorylates T131 , identifying TaSP as a substrate in vitro. Confocal microscopy and proximity ligation assays suggest an interaction between CDK1 and TaSP in T. annulata-infected cells. Further studies demonstrated a nearly complete co-localization of the pThr-Pro signal and TaSP only in cells in interphase, pointing towards a cell cycle-dependent event. Immunostainings of isolated, non-permeabilized schizonts confirmed the presence of the pThr-Pro epitope on the schizont's surface. Lambda phosphatase treatment abolished the pThr-Pro signal of the schizont, which was reconstituted by the addition of CDK1-cyclin B. Treatment of T. annulata-infected cells with the CDK1 inhibitor purvalanol A resulted in morphological changes characterized by tubulin-rich cell protrusions and an extension of the schizont, and a dose-dependent reduction of BrdU incorporation and Ki67 staining of T. annulata-infected cells, demonstrating a clear impact on the Theileria-dependent proliferation of the bovine host cell. Our data reveal the parasite surface protein TaSP as a target for the host cell kinase CDK1, a major player during cell division. Targeting the uncontrolled proliferation of Theileria-infected cells is a novel and reasonable approach to limit parasite load in order to facilitate a successful cellular immune response against the parasite.
Assuntos
Proteína Quinase CDC2/metabolismo , Doenças dos Bovinos/prevenção & controle , Proteínas de Protozoários/metabolismo , Theileria annulata/imunologia , Theileriose/prevenção & controle , Motivos de Aminoácidos , Animais , Proteína Quinase CDC2/antagonistas & inibidores , Bovinos , Doenças dos Bovinos/parasitologia , Proliferação de Células , Ensaio de Imunoadsorção Enzimática/veterinária , Fosforilação , Purinas/farmacologia , Esquizontes , Theileria annulata/metabolismo , Theileriose/parasitologiaRESUMO
The parasitic roundworm Trichinella spiralis is most commonly transmitted to humans through consumption of raw or undercooked meat of infected pigs or game. To prevent human infection, slaughterhouses perform meat safety surveillance using the gold standard "Magnetic Stirrer Method". We introduce a fast and objective method using automated detection of specific Trichinella spiralis antigens by a newly developed immunoassay based on chemiluminescence (ChLIA). Panel A comprised muscle tissue samples from non-infected pigs (n=37). Panel B comprised muscle tissue samples from non-infected pigs spiked with different amounts of Trichinella larvae without collagen capsules (n=56). Panel C contained muscle tissue samples from experimentally infected pigs including Trichinella larvae encapsulated in collagen (n=32). Each sample was shredded with PBS buffer in a knife mill, destroying Trichinella larvae. Following centrifugation, the supernatant (muscle tissue extract containing released excretory and secretory Trichinella spiralis antigens) was used for Trichinella-specific antigen detection by the new Trichinella ChLIA. The overall accuracy of the Trichinella ChLIA was 97.6 %. The specificity of the Trichinella ChLIA was 100 % (panel A). The sensitivity in samples from experimentally infected pigs was 100 % representing a detection limit of 0.01 larvae per gram. Cross-reactivity with parasites other than Trichinella spp. was not observed. This new meat inspection method for the detection of Trichinella spiralis antigens presents high specificity and high sensitivity, especially in truly infected samples. In contrast to the gold standard, this new approach to meat safety surveillance does not require longsome digestion or microscopy by trained personnel.
RESUMO
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