87 research outputs found

    Evaluación de la Calidad del Mantenimiento y su Impacto en la Productividad en el Área de Secado Mecánico de Exportadora Atlantic S.A, I semestre 2017, Sébaco, Matagalpa

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    El presente trabajo investigativo se realizó en el Beneficio de Café Seco Atlantic S.A. ubicada en la carretera Sébaco, Matagalpa, el objetivo de la presente investigación fue evaluar la calidad del mantenimiento actual en el área del Secado Mecánico del Beneficio. Las empresas industriales se encuentran en un momento decisivo debido a la inclusión de nuestro país en los mercados internacionales ya que según el Instituto Nacional de Información del Desarrollo (INIDE), la diferencia de productividad media entre el sector industrial de los países desarrollados y los de la región es de 3 a 1. Estudios como Creación de Indicadores de Productividad permiten conocer las particularidades de las diferentes ramas industriales, de modo que puedan plantearse alternativas de viabilidad. De igual manera, contar con indicadores claves para estos sectores. Para alcanzar dicho objetivo se estudiaron los diferentes indicadores que pueden ser medidos en el mantenimiento implementado en la maquinaria, como es la confiabilidad, disponibilidad, mantenibilidad y también la eficiencia general de los equipos. Los resultados obtenidos revelaron que la cuadrilla de mantenimiento de la empresa Exportadora Atlantic S.A realiza un mantenimiento basándose en la aplicación de indicadores medibles, aunque por otra parte hace falta reforzamiento en cuanto a la aplicación de esto

    Estudio y revisión de control de calidad de bloques de concreto elaborados en 5 fábricas semi-industriales en la ciudad de Managua

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    Este trabajo investigativo busca estudiar los procesos productivos y analizar la calidad del producto terminado de 5 fábricas semi industriales en la ciudad de Managua, con el fin de brindar asesoramiento e impulsar a una mejora en la calidad del sistema constructivo a base de mampostería

    Inhibition of eIF2α dephosphorylation inhibits ErbB2-induced deregulation of mammary acinar morphogenesis

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    <p>Abstract</p> <p>Background</p> <p>The ErbB2/Her2/Neu receptor tyrosine kinase is amplified in ~30% of human breast cancers. Phosphorylation of the translation initiation factor, eIF2α inhibits global protein synthesis and activates a stress signaling and growth suppressive program. We have shown that forced phosphorylation of eIF2α can suppress head and neck, colorectal carcinoma and multiple myeloma tumor growth and/or survival. Here we explore whether ErbB2 modulates eIF2α phosphorylation and whether forced phosphorylation of the latter can antagonize ErbB2 deregulation of mammary acinar morphogenesis.</p> <p>Results</p> <p>We tested whether ErbB2 signaling influenced eIF2α signaling and whether enhanced phosphorylation of the latter affected ErbB2-deregulated mammary acinar development. We obtained stable MCF10A cells overexpressing wild-type (Wt) Neu/ErbB2 or a constitutively active (CA) variant via retroviral delivery or mammary tumor cells from MMTV-Neu tumors. Western blotting, RT-PCR and confocal microscopy were used to analyze the effects of ErbB2 activation on eIF2α signaling and the effect of the GADD34-PP1C inhibitor salubrinal. Wt- and MMTV-Neu cells formed aberrant acini structures resembling DCIS, while CA-ErbB2 overexpression induced invasive lesions. In these structures we found that CA-ErbB2 but not the Wt variant significantly down-regulated the pro-apoptotic gene CHOP. This occurred without apparent modulation of basal phosphorylation of PERK and eIF2α or induction of its downstream target ATF4. However, inhibition of eIF2α dephosphorylation with salubrinal was sufficient to inhibit Wt- and CA-ErbB2- as well as MMTV-Neu-induced deregulation of acinar growth. This was linked to enhanced CHOP expression, inhibition of proliferation, induction of apoptosis and luminal clearing in Wt-ErbB2 and to inhibition of cyclin D1 levels and subsequent proliferation in CA-ErbB2 cells.</p> <p>Conclusion</p> <p>Depending on the strength of ErbB2 signaling there is a differential regulation of CHOP and eIF2α phosphorylation. ErbB2 uncouples in basal conditions eIF2α phosphorylation from CHOP induction. However, this signal was restored by salubrinal treatment in Wt-ErbB2 expressing MCF10A cells as these DCIS-like structures underwent luminal clearing. In CA-ErbB2 structures apoptosis is not induced by salubrinal and instead a state of quiescence with reduced proliferation was achieved. Treatments that stabilize P-eIF2α levels may be effective in treating ErbB2 positive cancers without severely disrupting normal tissue function and structure.</p

    Inhibition of Proliferation by PERK Regulates Mammary Acinar Morphogenesis and Tumor Formation

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    Endoplasmic reticulum (ER) stress signaling can be mediated by the ER kinase PERK, which phosphorylates its substrate eIF2α. This in turn, results in translational repression and the activation of downstream programs that can limit cell growth through cell cycle arrest and/or apoptosis. These responses can also be initiated by perturbations in cell adhesion. Thus, we hypothesized that adhesion-dependent regulation of PERK signaling might determine cell fate. We tested this hypothesis in a model of mammary acini development, a morphogenetic process regulated in part by adhesion signaling. Here we report a novel role for PERK in limiting MCF10A mammary epithelial cell proliferation during acinar morphogenesis in 3D Matrigel culture as well as in preventing mammary tumor formation in vivo. We show that loss of adhesion to a suitable substratum induces PERK-dependent phosphorylation of eIF2α and selective upregulation of ATF4 and GADD153. Further, inhibition of endogenous PERK signaling during acinar morphogenesis, using two dominant-negative PERK mutants (PERK-ΔC or PERK-K618A), does not affect apoptosis but results instead in hyper-proliferative and enlarged lumen-filled acini, devoid of proper architecture. This phenotype correlated with an adhesion-dependent increase in translation initiation, Ki67 staining and upregulation of Laminin-5, ErbB1 and ErbB2 expression. More importantly, the MCF10A cells expressing PERKΔC, but not a vector control, were tumorigenic in vivo upon orthotopic implantation in denuded mouse mammary fat pads. Our results reveal that the PERK pathway is responsive to adhesion-regulated signals and that it is essential for proper acinar morphogenesis and in preventing mammary tumor formation. The possibility that deficiencies in PERK signaling could lead to hyperproliferation of the mammary epithelium and increase the likelihood of tumor formation, is of significance to the understanding of breast cancer

    Morphometric and Vascular Analyses and MMP-2 Expression in Bladders of Animals with Bovine Enzootic Haematuria

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    Background: Bovine enzootic haematuria is a chronic, non-infectious disease caused by the ingestion of bracken Pteridium aquilinum that contain ptaquiloside, substance responsible for the development of neoplasms in combination with bovine papillomavirus infection. Studies examining metalloproteinases have shown that these enzymes may be useful as prognostic markers and many studies have correlated the intratumoural microvessel density and incidence of metastasis in a variety of cancers, including bladder cancer. This study aimed to evaluate the urothelial morphology and vasculature and quantify the expression of the enzyme metalloproteinase-2 in the bladder lesions of bovine with enzootic haematuria.Materials, Methods &amp; Results: Forty bladders with macroscopic lesions were subjected to routine histological processing. The material was stained using the Hematoxylin-Eosin (HE) and Weigert's resorcin-fuchsin staining methods. The morphometric analysis included the measurement of the total thickness of the urothelium. Microscopically, the lesions were differentiated as neoplastic or non-neoplastic, and the vascular changes were characterised as vascular proliferation, ectasia, dilation and thickening and the material stained using the Weigert's resorcin-fuchsin method was used to evaluate sclerosis and the vascular fibroelastosis. The metalloproteinase expression was evaluated using an anti-metalloproteinase-2 antibody. The main non-neoplastic lesions found in the urothelium included clear cell metaplasia, dysplasia, hyperplasia, haemorrhage, cystitis cystica and Brunn's nests and the neoplastic lesions were haemangioma, myxoma, transitional cell carcinoma, adenocarcinoma, in situ carcinoma and haemangiosarcoma. The urothelium measurements revealed differences between the epithelial thicknesses of bladders with and without neoplasms. The bladder vasculature evaluation revealed the frequent occurrence of different pathological aspects, such as vascular proliferation, dilation, expansion, ectasia and thickening; more severe vascular proliferation, thickening and fibroelastosis were observed in bladders with neoplasms. Metalloproteinase-2 expression was observed in the epithelial cells, fibroblasts, endothelial cells and smooth muscle cells present in the tumour tissue and was a significant increase in the expression of MMP-2 in the neoplasms of mesenchymal origin compared to the neoplasms of epithelial origin.Discussion: The presence of a large variety of non-neoplastic lesions indicates the possibility that there are other factors concomitant to BEH involved. Epithelial hyperplasia and metaplasia, for example, could be the result of damage caused by bovine papillomavirus type 2 or even an altered urine pH. Furthermore, it is believed that the bladder has the capacity to generate various types of neoplasms due to the different histological components of the bladder, thus enabling it to generate both mesenchymal and epithelial lesions. The thickness of the urothelium was greater in all the quadrants with neoplasms compared to the quadrants without neoplasms. These data revealed that it is possible to use less invasive diagnostic imaging methods to characterise bovine enzootic haematuria and to measure tumour progression based on the severity of vascular changes. The vascular proliferation and thickening were significant in bladders with neoplasms, which may be explained by the fact that tumours require an extensive vascular supply. In addition, many tumours release vascular growth factors and promote neovascularisation. The intensity of the immunostaining of metalloproteinase-2 differed among the different types of neoplasms. However, due to the diversity of the tumours, it was not possible to establish a relationship between metalloproteinase-2 expression and tumour progression

    Timoma em cão. Relato de caso

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    Uma cadela, Dachshund, quatro anos, foi encaminhada ao H.V. da FMVZ-UNESP-Botucatu-SP com histórico de prostração, emagrecimento progressivo, anorexia, cansaço e tosse seca. Ao exame clínico observou-se apatia, secreção nasal serosa bilateral e dispnéia intensa. Radiografia torácica demonstrou efusão pleural, edema pulmonar acentuado, desvio dorsal da traquéia e possível massa mediastinal. A ultra-sonografia, após drenagem torácica, confirmou a presença de massa mediastinal, sendo classificada como neoplasia maligna de origem epitelial pela citologia aspirativa por agulha fina. O animal veio a óbito logo após o diagnóstico de neoplasia. À necropsia constatou-se massa mediastinal encapsulada, consistência macia e superfície de corte com coloração branco-acinzentada e áreas necrótico-hemorrágicas, localizada na região ântero-ventral do tórax. O exame histopatológico demonstrou células epiteliais neoplásicas, células linfóides (timócitos) com morfologia normal, vasos sangüíneos de pequeno e médio calibre, formações císticas com conteúdo eosinofílico e corpúsculos de Hassall. A imunohistoquímica apresentou positividade para citoqueratina AE1/AE3 e UCHL, confirmando o diagnóstico de timoma.A four years old Dachshund female dog was guided to the Veterinary Hospital of FMVZ-UNESP-Botucatu-SP with history of prostration, progressive weigh loss, anorexia, fatigue and drought coughs. Apathy, serous bilateral nasal discharge, intense dyspneia and lung edema were observed in the clinical exam. Thoracic X-ray showed pleural effusion and dorsal deviation of trachea and the presence of a mediastinal mass. The ultrasonography, after thoracic drainage and fine needle aspiration cytology, confirmed the presence of mediastinal mass classified as malignant neoplasm of epithelial origin. The animal died soon after the exams due to its bad clinical conditions. At necropsy mediastinal mass was located in the antero-ventral area of the thorax. It was encapsulated, with soft consistency and gray coloration with hemorragic and necrotic areas in the cut surface. The histopathology demonstrated neoplastic epithelial cells, lymphoid cells (thymocytes) with normal morphology, blood vessels of small and medium caliber, cystic formations with eosinophilic contents and Hassall corpuscles. The immunohistochemistry reaction was positive for cytokeratin AE1/AE3 and UCHL, confirming the thymoma diagnosis

    Primary Diffuse Large B Cell Lymphoma in Kidney with Involvement of Central Nervous System and Heart in a Siamese Cat

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    Background: Lymphoma is the most common neoplasia in cats and usually happens in middle-aged males of European breeds, FeLV-positive test is also observed in 25% to 50% of these cases. The diagnostic of renal lymphoma is based on clinical signs, the diagnosis is based on clinical signs associated with additional tests. Histological an immunohistochemical evaluations allows the classifcation which can provide prognostic information. Central nervous system metastasis is frequently reported, but lingual and lung lobe extension were also reported. Here, we report a case of renal lymphoma with systemic involvement of heart and CNS in a cat. Case: A 3-year-old male Siamese cat presented with weight loss, emesis, anorexia, polydipsia and polyuria for at least 3 weeks. The clinical parameters were stable, but presenting pale mucosal membrane and also severe dehydration. Complete blood count and chemistry profle revealed anemia and severe azotemia. On abdominal palpation, bilateral renomegaly and irregular contours of both kidneys were also detected. The kidneys were enlarged and had irregular contours on palpation, confrmed by abdominal ultrasonography, that revealed kidneys with markedly irregular contours, and the presence of fluid with high cellularity between cortical and renal capsule (capsular fluid). An aspiration citology by fne-needle from the capsular fluid guided by ultrasound was collected and sent to cytological analysis, which suggested lymphoma. The aspirate was moderately cellular and consisted of large round cells with distinct, scant, basophilic cytoplasm, round nuclei with dense chromatin, inconspicuous nucleoli, and large amount of naked cells. On the second day of treatment the cat presented a cardiopulmonary arrest not responsive to cardiopulmonary cerebral resuscitation, died, and the owner authorized the necropsy, allowing the renal biopsy showing that the same neoplastic cells presented in kidneys were also seen in heart and central nervous system, suggesting the occurrence of primary renal lymphoma with involvement of to these tissues, and the diagnosis was high grade diffuse large cell lymphoma. And also histopathological exam diagnosed high grade diffuse large cell lymphoma. Discussion: The patient died, and the post-mortem histological analysis confrmed the diagnosis of primary diffuse large B cell lymphoma in kidney with systemic involvement of heart and central nervous system (CNS). Lymphoma is the most common renal tumor in cats, however primary feline renal tumors are rare and few reports are available at this time. Here we report the occurrence of primary renal lymphoma in a Siamese cat, and there´s no previous report of this type of lymphoma especially in this breed. More investigation is needed to evaluate the susceptibility of Siamese cat breed to the development of primary renal lymphoma. It is diffcult to determine whether the renal involvement is primary or it is a consequence of the multicenter type. In the present report the same neoplasic infltration observed in kidney was also found in central nervous system and heart. The cytology is a quickly, non-invasive, and sensitivity method for the diagnostic of lymphoma. However, the cytology do not provides the immune diagnosis of diffuse large B cell, and although it is useful for staging lymphoma, histopathology and immunohistochemistry is always necessary for classifcation and grading. Since the diagnosis, the cat of this report survived only 2 days, which reinforces the bad prognosis of renal lymphoma. The renal lymphoma should be considered as a potential cause of severe azotemia, and should be taken as the mainly differential diagnosis among neoplasias of kidneys in cats.Keywords: oncology, feline, extranodal, lymph nodes, cance

    Classificação citológica dos linfomas caninos

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    Os linfomas estão entre as neoplasias mais frequentes na espécie canina. Do ponto de vista etiológico, epidemiológico, clínico, morfológico e imunofenotípico, os linfomas caninos apresentam muitas semelhanças com os linfomas não-Hodgkin humanos e os esquemas de classificação destes têm sido utilizados na espécie canina. O objetivo do presente trabalho foi aplicar aos linfomas caninos as classificações de Kiel, Working Formulation e Fournel-Fleury et al. (1994), em material colhido pelo método da PAAF (Punção Aspirativa por Agulha Fina). De acordo com a Classificação de Kiel, 61,02% (36 casos) das neoplasias se enquadram como de grau alto 38,98% (23 casos) como de grau baixo. Segundo a Classificação da Working Formulation, 11,86% (sete casos) foram classificados linfomas de grau baixo, 61,02% (36 casos) de grau intermediário e 27,12% (16 casos) de grau alto. Utilizando a classificação proposta por Fournel-Fleury et al. (1994), 38,98% (23 casos) dos animais que apresentaram linfomas de grau baixo e 61,02% (36 casos) de grau intermediário ou alto. Concluindo, a PAAF é um método de diagnóstico que pode ser empregado na classificação dos linfomas caninos. A classificação que mostrou melhores resultados foi a de Kiel, que tem por característica principal a ênfase nos achados citológicos.Lymphoma is among the most frequent canine neoplasia and share many similarities with human non-Hodgkin's lymphoma in respect of etiology, epidemiology, clinical, morphological and immunophenotipical aspects. Human classification schemes have been used in canine lymphoma. The aim of this work was apply Kiel, Working Formulation and Fournel-Fleury's et al. (1994) classification in Fine Needle Aspiration (FNA) cytology matherial. According to Kiel scheme 61.02% (36 cases) were high-grade lymphomas and 38.98% (23 cases) low grade. The Working Formulation, showed 11.86% (7 cases) of low grade, 61.02% (36 cases) intermediary grade and 27.12% (16 cases) high grade. In Fournel-Fleury's protocol revealed a predominance of high-grade lymphoma, with 61.02% (36 cases) over 38.98% (23 cases) of low grade. In conclusion, FNA can be used as a diagnostic method and in canine lymphoma cytological classification. Kiel's system showed the best results, once is based on cytologic basis

    Proliferação celular nos linfomas caninos

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    O estudo dos linfomas caninos além de abordar a classificação morfológica e imunofenotípica necessita ser ampliado para que se tenha a avaliação da cinética celular. Esta verificação só pode ser feita com segurança quando são avaliados os parâmetros que indicam a taxa de proliferação celular. No homem, estes fatores têm influência no prognóstico e no tratamento dos limfomas. Os 40 linfomas utilizados neste trabalho foram classificados de acordo com a classificação de Kiel e a imunofenotipagem utilizou CD3 (linfócitos T) e CD79a (linfócitos B). A proliferação celular foi avaliada pelos métodos de contagem dos AgNORs e Ki-67 (MIB-1) De acordo com a classificação de Kiel os linfomas de alto grau foram os mais freqüentes, a imunofenotipagem mostrou a mesma freqüência de linfomas T e B. Quando avaliada a proliferação celular houve diferença significativa entre os linfomas de alto e baixo grau tanto pelo método do AgNOR como do KI-67.(MIB-1), porém não foram estatisticamente entre os imunofenótipos Entre as neoplasias de alto grau de malignidade a média de número de NORs por núcleo de célula neoplásica foi de 1,37 ± 0,32, e nos casos de baixo grau de 0,98 ± 0,36, de acordo com o KI-67 a média do percentual de células positivas foi de 43,19% ± 19,01, e 14,09% ± 11,74 nos casos de alto e baixo grau, respectivamente.Lymphoma studies deals with morphological classification and immunophenotypic features and they have to be amplified for cellular kinetics evaluation. This evaluation can only be safely made, when the proliferative index are evaluated. In men the proliferation index have, most of the time, important influence in the neoplasia prognosis and treatment In this work it was used 40 canine lymphomas that were classified according to Kiel methods and immunophenotype was achieved with CD3 (T lymphocyte) and CD79a (B lymphocyte). Cellular proliferation was evaluated by AgNORs and Ki-67 (MIB-1) According to Kiel classification system, high grade lymphomas were more frequent and T and B lymphoma showed the same frequency.When cellular proliferation was evaluated, there was a significant difference between high grade and low grade lymphomas by AgNOR and Ki-67 (MIB-1) methods, but did not differ when comparing immunophenotype. Among high grade malignancy lymphomas the NORs medium number per cell nucleoli was 1.37± 0.32 and in low grade was 0.98± 0.36, concerning Ki-67 the positive cellular percentual was 43.19% ± 19.01, e 14.09% ± 11.74 in high and low grade, respectively
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