131 research outputs found

    Aplicación de algunos ioduros de alcohilo a la separación de selenio y teluro

    Get PDF
    Fil: D'Agostino, Aída. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil: Massani, Zulema M.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

    Correlating Antimicrobial activity and Structure in Montmorillonite modified with Hexadecyltrimethylammonium and Silver

    Get PDF
    The relationship between antimicrobial properties and structure of montmorillonite (MMT) containing hexadecyltrimethylammonium bromide (HDTMA-Br) and silver (Ag) was determined. HDTMA was adsorbed at the clay interlayer by a cation exchange, through the positive head of the ammonium group. At higher surfactant loadings (100 and 200% cation exchange capacity (CEC); MH1 and MH2 samples, respectively) the prevalence of weak adsorption (Van der Waals forces) was observed; whereas below the clay CEC (50%, MH0.5) strong interactions predominated (cation exchange). These different interactions impacted on antimicrobial activity, increasing bactericidal capacity when the surfactant was more available to diffuse. For organo-montmorillonites (OMMT) and all samples with Ag, zeta potential pointed out electrical charge changes on the outer surface, respect to MMT. XPS analyses showed peaks attributed to clusters formation, silver oxidation, and Ag0 in MMTAg and MH0.5-Ag. The Ag0 peak was also present in MH1-Ag and MH2-Ag, the later showing an extra peak associated with AgBr. HDMTA+ and Ag adsorbed on the MMT acted synergistically against Staphylococcus aureus. This effect was less noticeable for Escherichia coli and the result was attributed to both, E. coli outer envelope which might lower the efficacy of HDMTA+ adsorbed on the MMT, and decreasing silver proportions when the surfactant loading increased. MH1-Ag presented the best bactericidal properties, showing synergistic effects against S. aureus, while maintaining activity against E. coli compared to MMT-Ag. Understanding MMT-HDMTA-Ag efficacy contributes to the design of new antimicrobial materials for potential applications in health careFil: Fernández Solarte, Alejandra María. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; Argentina. Corporacion Universitaria Minuto de Dios.; ColombiaFil: Blanco Massani, Mariana Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Molina, Vanesa Magali. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Benítez Guerrero, Mónica. Universidad de Malaga. Facultad de Ciencias; EspañaFil: Torres Sánchez, Rosa M.. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; Argentin

    Mineralización del fósforo orgánico

    Get PDF
    p.157-163Con la finalidad de estudiar el índice de mineralización del fósforo se efectuaron incubaciones de suelos naturales y previamente esterilizados, solos y en contacto con resina Amberlite IRA 400 en su forma C 0 3 H - y Cl- llevada a pH 7,0. Las variaciones del fósforo inorgánico se estudiaron en períodos entre 1 y 56 días

    Evolution of minimally invasive techniques and surgical outcomes of ALPPS in Italy: a comprehensive trend analysis over 10 years from a national prospective registry

    Get PDF
    BackgroundSince 2012, Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) has encountered several modifications of its original technique. The primary endpoint of this study was to analyze the trend of ALPPS in Italy over a 10-year period. The secondary endpoint was to evaluate factors affecting the risk of morbidity/mortality/post-hepatectomy liver failure (PHLF).MethodsData of patients submitted to ALPPS between 2012 and 2021 were identified from the ALPPS Italian Registry and evaluation of time trends was performed.ResultsFrom 2012 to 2021, a total of 268 ALPPS were performed within 17 centers. The number of ALPPS divided by the total number of liver resections performed by each center slightly declined (APC = - 2.0%, p = 0.111). Minimally invasive (MI) approach significantly increased over the years (APC = + 49.5%, p = 0.002). According to multivariable analysis, MI completion of stage 1 was protective against 90-day mortality (OR = 0.05, p = 0.040) as well as enrollment within high-volume centers for liver surgery (OR = 0.32, p = 0.009). Use of interstage hepatobiliary scintigraphy (HBS) and biliary tumors were independent predictors of PHLF.ConclusionsThis national study showed that use of ALPPS only slightly declined over the years with an increased use of MI techniques, leading to lower 90-day mortality. PHLF still remains an open issue

    Activation of Fas/FasL pathway and the role of c-FLIP in primary culture of human cholangiocarcinoma cells

    Get PDF
    Intrahepatic cholangiocarcinoma (iCCA) represents a heterogeneous group of malignancies emerging from the biliary tree, often in the context of chronic bile ducts inflammation. The immunological features of iCCA cells and their capability to control the lymphocytes response have not yet been investigated. The aims of the present study were to evaluate the interaction between iCCA cells and human peripheral blood mononuclear cells (PBMCs) and the role of Fas/FasL in modulating T-cells and NK-cells response after direct co-culture. iCCA cells express high levels of Fas and FasL that increase after co-culture with PBMCs inducing apoptosis in CD4(+), CD8(+) T-cells and in CD56(+) NK-cells. In vitro, c-FLIP is expressed in iCCA cells and the co-culture with PBMCs induces an increase of c-FLIP in both iCCA cells and biliary tree stem cells. This c-FLIP increase does not trigger the caspase cascade, thus hindering apoptotis of iCCA cells which, instead, underwent proliferation. The increased expression of Fas, FasL and c-FLIP is confirmed in situ, in human CCA and in primary sclerosing cholangitis. In conclusion our data indicated that iCCA cells have immune-modulatory properties by which they induce apoptosis of T and NK cells, via Fas/FasL pathway, and escape inflammatory response by up-regulating c-FLIP system

    Neuroendocrine tumors presenting with thyroid gland metastasis: a case series

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>Autopsy series have shown that metastasis to the thyroid gland has occurred in up to 24% of patients who have died of cancer. Neuroendocrine tumors may metastasize to thyroid gland.</p> <p>Case presentations</p> <p>Case 1 was a 17-year-old Turkish woman who was referred from our Endocrinology Department for a thyroidectomy for treatment of neuroendocrine tumor metastasis. She was treated with a bilateral total thyroidectomy. Histopathological examination results were consistent with a neuroendocrine tumor; neoplastic cells showed strong immunoreactivity to chromogranin A and synaptophysin, but the immunohistochemical profile was inconsistent with medullary thyroid carcinoma in that the tumor was negative for calcitonin, carcinoembryonic antigen, and thyroid transcription factor-1.</p> <p>Case 2 was a 54-year-old Turkish woman who presented with a 3-cm nodule on her right thyroid lobe. She had undergone surgery for a right lung mass four years previously. After a right pneumonectomy, thymectomy and lymph node dissection, a typical carcinoid tumor was diagnosed. Under ultrasonographic guidance, fine needle aspiration biopsy of her right thyroid pole nodule was performed and the biopsy was compatible with a neuroendocrine tumor metastasis. She was treated with a bilateral total thyroidectomy. Histopathological examination indicated three nodular lesions, 5 cm and 0.4 cm in diameter in her right lobe and 0.1 cm in diameter in her left lobe. The tumors were consistent with a neuroendocrine phenotype, showing strong immunoreactivity to chromogranin A and synaptophysin.</p> <p>Conclusion</p> <p>Thyroid nodules detected during follow-up of neuroendocrine tumor patients should be thoroughly investigated. A fine needle aspiration biopsy of the thyroid confirms the diagnosis in most cases and leads to appropriate management of those patients and may prevent unnecessary treatment approaches.</p

    Ostomy closure rate during COVID-19 pandemic. An Italian multicentre observational study

    Get PDF
    During the corona virus disease 2019 (COVID-19) pandemic, most of the surgical procedures were performed for emergencies or oncologic reasons to the detriment of the remaining elective procedures for benign conditions. Ileostomy or colostomy creation are sequelae of oncologic or emergency colorectal surgery, but their closure does not fall within the definition of oncologic or emergency surgery. The aim of this retrospective multicentre observational study is to report the impact of COVID-19 pandemic on the ostomy closure rate in Italy. Data regarding ileostomy and colostomy creation and closure from 24 Italian centres, during the study period (March 2020–February 2021) and during the control period (March 2019–February 2020) were collected. Three hospitals (12.5%) were COVID free. The number of colostomies and ileostomies created and closed in the same period was lower (-18.8% and-30%, respectively) in the study period in comparison to the control period (p = 0.1915 and p = 0.0001, respectively), such as the ostomies closed in the analysed periods but created before (colostomy-36.2% and ileostomy-7.4%, p = 0.2211 and p = 0.1319, respectively). Overall, a 19.5% reduction in ostomies closed occurred in the study period. Based on the present study, a reduction in ostomy closure rate occurred in Italy between March 2020 and February 2021. During the pandemic, the need to change the clinical practice probably prolonged deterioration of quality of life in patients with ostomies, increasing number of stomas that will never be closed, and related management costs, even if these issues have not been investigated in this study

    Appendectomy during the COVID-19 pandemic in Italy: a multicenter ambispective cohort study by the Italian Society of Endoscopic Surgery and new technologies (the CRAC study)

    Get PDF
    Major surgical societies advised using non-operative management of appendicitis and suggested against laparoscopy during the COVID-19 pandemic. The hypothesis is that a significant reduction in the number of emergent appendectomies was observed during the pandemic, restricted to complex cases. The study aimed to analyse emergent surgical appendectomies during pandemic on a national basis and compare it to the same period of the previous year. This is a multicentre, retrospective, observational study investigating the outcomes of patients undergoing emergent appendectomy in March-April 2019 vs March-April 2020. The primary outcome was the number of appendectomies performed, classified according to the American Association for the Surgery of Trauma (AAST) score. Secondary outcomes were the type of surgical technique employed (laparoscopic vs open) and the complication rates. One thousand five hundred forty one patients with acute appendicitis underwent surgery during the two study periods. 1337 (86.8%) patients met the inclusion criteria: 546 (40.8%) patients underwent surgery for acute appendicitis in 2020 and 791 (59.2%) in 2019. According to AAST, patients with complicated appendicitis operated in 2019 were 30.3% vs 39.9% in 2020 (p = 0.001). We observed an increase in the number of post-operative complications in 2020 (15.9%) compared to 2019 (9.6%) (p &lt; 0.001). The following determinants increased the likelihood of complication occurrence: undergoing surgery during 2020 (+ 67%), the increase of a unit in the AAST score (+ 26%), surgery performed &gt; 24 h after admission (+ 58%), open surgery (+ 112%) and conversion to open surgery (+ 166%). In Italian hospitals, in March and April 2020, the number of appendectomies has drastically dropped. During the first pandemic wave, patients undergoing surgery were more frequently affected by more severe appendicitis than the previous year's timeframe and experienced a higher number of complications. Trial registration number and date: Research Registry ID 5789, May 7th, 202

    Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

    Get PDF
    Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic
    corecore