Polydimethylsiloxane Surface Modification of Microfluidic Devices for Blood Plasma Separation.

Over the last decade, researchers have developed a variety of new analytical and clinical diagnostic devices. These devices are predominantly based on microfluidic technologies, where biological samples can be processed and manipulated for the collection and detection of important biomolecules. Polydimethylsiloxane (PDMS) is the most commonly used material in the fabrication of these microfluidic devices. However, it has a hydrophobic nature (contact angle with water of 110°), leading to poor wetting behavior and issues related to the mixing of fluids, difficulties in obtaining uniform coatings, and reduced efficiency in processes such as plasma separation and molecule detection (protein adsorption). This work aimed to consider the fabrication aspects of PDMS microfluidic devices for biological applications, such as surface modification methods. Therefore, we studied and characterized two methods for obtaining hydrophilic PDMS surfaces: surface modification by bulk mixture and the surface immersion method. To modify the PDMS surface properties, three different surfactants were used in both methods (Pluronic® F127, polyethylene glycol (PEG), and polyethylene oxide (PEO)) at different percentages. Water contact angle (WCA) measurements were performed to evaluate the surface wettability. Additionally, capillary flow studies were performed with microchannel molds, which were produced using stereolithography combined with PDMS double casting and replica molding procedures. A PDMS microfluidic device for blood plasma separation was also fabricated by soft lithography with PDMS modified by PEO surfactant at 2.5% (v/v), which proved to be the best method for making the PDMS hydrophilic, as the WCA was lower than 50° for several days without compromising the PDMS's optical properties. Thus, this study indicates that PDMS surface modification shows great potential for enhancing blood plasma separation efficiency in microfluidic devices, as it facilitates fluid flow, reduces cell aggregations and the trapping of air bubbles, and achieves higher levels of sample purity.

Epithelioid Hemangioendothelioma in a Liver Transplant Recipient: A Case Report of an Extremely Rare Tumor.

Epithelioid hemangioendothelioma is a very rare vascular neoplasm, which is often multifocal or metastatic at diagnosis. Most frequently arises in the liver, followed by the lung and bones. The authors present a case of a liver transplant recipient who developed a pattern of hepatic cholestasis associated with the appearance of a proliferative hepatic lesion with infiltrative growth. Histological examination and immunohistochemical study were compatible with the diagnosis of epithelioid hemangioendothelioma. Pulmonary micronodules were detected and lung metastases were hypothesized. Therefore, bronchoscopy was performed, which turned out to be normal, and cytology was negative for neoplastic cells. After a multidisciplinary discussion, liver re-transplantation was decided. After 8 years of follow-up, the patient is clinically stable, with no graft dysfunction, no neoplastic recurrence, and dimensional stability of the pulmonary micronodules. Patients with organ transplant have higher risk of developing carcinoma compared to the general population. The development of cancer is a multifactorial process and little is known about the etiology of epithelioid hemangioendothelioma. No standard treatment strategy has been defined yet, and the natural course of the disease is heterogenous and the individual prognosis unpredictable. Complete surgical resection is offered to patients with unifocal disease, and those with unresectable disease should be evaluated for orthotopic liver transplantation.

O hemangioendotelioma epitelióide é uma neoplasia vascular extremamente rara, muitas vezes multifocal ou metastática ao diagnóstico. O local mais frequente afetado é o fígado, seguido pelo pulmão e ossos. Os autores apresentam o caso de uma doente com antecedentes de transplante hepático que desenvolveu um padrão de colestase associado ao aparecimento de uma lesão hepática proliferativa e de crescimento infiltrativo. O exame histológico e o estudo imuno-histoquímico foram compatíveis com hemangioendotelioma epitelióide. Foram detetados micronódulos pulmonares, tendo sido colocada a hipótese de se tratarem de metástases pulmonares. Assim, foi realizada broncoscopia, que não revelou alterações, estando a citologia negativa para células neoplásicas. Após discussão multidisciplinar, foi decidido o retransplante hepático. Após 8 anos de seguimento, a doente encontra-se clinicamente estável, sem disfunção do enxerto, sem recidiva neoplásica e com estabilidade dimensional dos micronódulos pulmonares. Doentes submetidos a transplante têm maior risco de desenvolver neoplasias em comparação com a população geral. O desenvolvimento da neoplasia é um processo multifatorial, sendo a etiologia do hemangioendotelioma epitelióide ainda pouco compreendida. Não existe uma estratégia terapêutica standard, sendo o curso natural da doença heterogêneo e o prognóstico individual imprevisível. A ressecção cirúrgica é a primeira opção terapêutica nos doentes com doença unifocal, aqueles com doença irressecável devem ser avaliados para transplante hepático.

A rare endoscopic pattern in a patient with gastroesophageal reflux disease

A 21-year-old man, with personal history of asthma and no usual medication, was referred to gastroenterology appointment due to dysphagia for solids and previous episodes of food impaction in the last 5 months. He also reported nocturnal heartburn without any other warning signs. Upper gastroscopy revealed a peptic stenosis in the distal esophagus. Histopathologic examination showed hyperplasia and numerous intraepithelial eosinophils, without dysplasia or malignancy. Therapy with a double-dose proton pump inhibitor (PPI) was started. (AU)

Safety of Endoscopy Units during the COVID-19 Pandemic.

Introduction: The COVID-19 pandemic drastically changed the daily routine of all healthcare systems worldwide, and endoscopy units were no exception. Endoscopic exams were considered to have a high risk of transmission, and therefore, the safety of endoscopy units and the consequent need for pre-endoscopy SARS-CoV-2 screening were questioned early on. The aim of our study was to assess the safety of endoscopy units during the COVID-19 pandemic, as well as the effectiveness/necessity for SARS-CoV-2 screening prior to endoscopies. Material and Methods: This is a retrospective and single-center study carried out in a Portuguese tertiary hospital. All patients who underwent endoscopic procedures between September 1, 2020 and February 28, 2021 were included. The pre-endoscopy screening consisted of a specific questionnaire or a RT-PCR test for SARS-CoV-2 (nasal and oropharyngeal swab). Data were obtained through patient's clinical records and the Trace COVID platform. Results: A total of 2,166 patients were included. Patients had a mean age of 61.8 years and were predominantly male (56.2%, n = 1,218). Eighty-one (3.7%) patients had previous SARS-CoV-2 infection, with a median difference of 74 days (IQ 40.5:160.5) between infection and endoscopy. Most patients (70.2%, n = 1,521) underwent PCR screening for SARS-CoV-2 up to 72 h before the procedure, with the remaining patients (29.8%, n = 645) answering a questionnaire of symptoms and risk contacts up to 3 days before endoscopy. Of the patients who underwent RT-PCR screening for SARS-CoV-2, 21 (1.4%) tested positive, and all were asymptomatic at the time of the screening. The evaluation for SARS-CoV-2 infection up to 14 days after the endoscopic exams identified 9 positive patients (0.42%) for SARS-CoV-2. The median difference in days between endoscopy and the diagnosis of infection was 10 days. Discussion/Conclusion: Pre-endoscopy screening with RT-PCR test for SARS-CoV-2 identified a very small number of patients with COVID-19 infection as well as patients with COVID-19 infection in the following 14 days. Therefore, the risk of infection in endoscopy units is negligible if screening of symptoms and risk contacts is applied and individual protective equipment is used.

Introdução: A pandemia COVID-19 mudou drasticamente o dia-a-dia de todos os sistemas de saúde a nível mundial e as unidades de endoscopia não foram exceção. Os exames endoscópicos foram considerados exames com alto risco de transmissão pelo que desde cedo se questionou a segurança das unidades de endoscopia e a consequente necessidade de rastreio SARS-CoV-2 pré-endoscopia. O objetivo do estudo foi avaliar a segurança das unidades de endoscopia durante a pandemia por COVID-19 bem como a eficácia/necessidade de rastreio SARS-CoV-2 prévio aos exames endoscópicos. Material e métodos: Foi desenvolvido um estudo retrospetivo e unicêntrico, no qual todos os doentes submetidos a exames endoscópicos entre 1 de setembro de 2020 e 28 de fevereiro de 2021 foram incluídos. Como estratégia de rastreio pré endoscopia foram aplicados questionários específicos de sintomas e contactos de risco, ou teste PCR de SARS-CoV-2 (zaragatoa nasal e orofaríngea). Os dados clínicos foram obtidos através do processo clínico do doente e da plataforma Trace COVID-19. Resultados: Foram incluídos um total de 2,166 doentes submetidos a exames endoscópicos durante o período de estudo. Os doentes incluídos apresentaram uma média de idades de 61.8 anos e eram maioritariamente do sexo masculino (56.2%, n = 1,218). 3.7% (n = 81) dos doentes já tinha tido infeção por COVID-19 no passado, sendo a mediana da diferença de dias entre a infeção e a data do exame de 74 dias. A maioria dos doentes (70.2%, n = 1,521) foi submetido a rastreio por PCR de SARS-CoV-2 até 72 horas antes do procedimento, sendo os restantes doentes (29.8%, n = 645) submetidos a um questionário de sintomas e contactos de risco realizado até 3 dias antes do procedimento. Dos doentes que realizaram rastreio por PCR de SARS-CoV-2, 21 (1.4%) apresentaram teste positivo, estando todos assintomáticos à data do teste. Aquando da verificação de infeção por SARS-CoV-2 até 14 dias após a realização dos exames endoscópicos apurou-se que apenas 9 doentes (0.42%) testaram positivo para SARS-CoV-2, sendo a mediana da diferença de dias entre a data do exame e o diagnóstico de infeção de 10 dias. Discussão/Conclusão: O rastreio pré-endoscopia com teste PCR de SARS-CoV-2 identificou um número reduzido de doentes infetados com COVID-19 e o número de doentes com infeção por COVID-19, nos 14 dias seguintes aos exames endoscópicos, foi muito baixo. Assim, se aplicado o rastreio de sintomas e contactos de risco, usados os equipamentos de proteção individual adequados, o risco de infeção nas unidades de endoscopia torna-se negligenciável.

Postcolonoscopy Colorectal Cancer in a Referral Center for Colorectal Cancer: Prevalence and Risk Factors.

Background and Aims: Colonoscopy is effective to detect and remove colorectal lesions. However, after a negative colonoscopy, cancers could be detected during the interval follow-up. This study was designed to identify characteristics and risk factors for postcolonoscopy colorectal cancer - interval type. Methods: Medical records of individuals who were newly diagnosed with colorectal cancer between January 2018 and December 2019 were reviewed. Clinical, demographic, and endoscopic variables were analyzed. Those with the diagnosis of colorectal cancer between two consecutive colonoscopies performed within the appropriated surveillance range were considered to have postcolonoscopy colorectal cancer - interval type. A comparison between the group of patients with non-postcolonoscopy colorectal cancer - interval type and the group of patients with postcolonoscopy colorectal cancer - interval type was then performed. Results: During the study period, 491 patients were newly diagnosed with colorectal cancer. Among them, 61 (12.4%) had postcolonoscopy colorectal cancer - interval subtype. Postcolonoscopy colorectal cancer - interval type was three times more prevalent on the proximal colon (p = 0.014) and was associated with the presence of two or more cardiovascular risk factors (aOR = 4.25; p = 0.016), cholecystectomy in the past (aOR = 10.09; p = 0.019), and family history of colorectal cancer on a first-degree relative (aOR = 4.25; p = 0.006). Moreover, isolated cardiovascular risk factors revealed a protective effect for the absence of all cardiovascular risk factors (aOR = 20; p = 0.034). The ROC curve associated with the multivariate model revealed a predictive power of 77.8% (p < 0.001). Conclusions: Postcolonoscopy colorectal cancer - interval type is more common in the proximal colon and in patients with a family history (first-degree relative) of colorectal cancer, two or more cardiovascular risk factors, and a history of cholecystectomy. All of these are easily detectable in clinical practice and may be of extreme importance in the control of postcolonoscopy colorectal cancer in the near future.

Introdução: A colonoscopia é eficaz a detetar e remover lesões do colon e reto. Contudo, após uma colonoscopia normal, podem ser detetadas neoplasias durante o intervalo de vigilância recomendado entre colonoscopias. O objetivo do estudo foi identificar características e fatores de risco para o desenvolvimento de cancro colorretal póscolonoscopia ­ subtipo de intervalo. Material e Métodos: Estudo retrospetivo e unicêntrico realizado entre janeiro de 2018 e dezembro de 2019 que incluiu todos os doentes diagnosticados de novo com cancro colorretal. Variáveis clínicas, demográficas e endoscópicas foram obtidas após consulta do processo clínico. Doentes com diagnóstico de cancro colorretal entre duas colonoscopias consecutivas, realizadas no intervalo de vigilância recomendado, foram considerados como tendo cancro colorretal pós-colonoscopia ­ subtipo de intervalo. Foi, então, realizada a comparação entre o grupo de doentes com cancro colorretal não pós colonoscopia ­ subtipo de intervalo e o grupo de doentes com cancro colorretal pós colonoscopia ­ subtipo de intervalo. Resultados: Durante o período de estudo, 491 doentes foram diagnosticados de novo com cancro colorretal. Destes, 61 (12.4%) foram considerados como tendo cancro colorretal pós-colonoscopia ­ subtipo de intervalo. O cancro colorretal pós-colonoscopia ­ subtipo de intervalo foi três vezes mais prevalente no colon proximal (p = 0.014) e associou-se a presença de dois ou mais fatores de risco cardiovasculares (aOR = 0.45; p = 0.016), colecistectomia no passado (aOR = 10.09; p = 0.0.19) e história familiar de cancro colorretal num familiar de primeiro grau (aOR = 4.25; p = 0.006). Aquando da análise dos fatores de risco cardiovasculares isolados, observou- se um fator protetor aquando da ausência de todos os fatores de risco cardiovasculares (aOR = 20; p = 0.034). A curva ROC associada ao modelo multivariado revelou um poder preditivo de 77.8% (p < 0.001). Conclusão: O cancro colorretal pós-colonoscopia ­ subtipo de intervalo é mais comum no colon proximal e em doentes com história familiar (em familiares de primeiro grau) de cancro colorretal, dois ou mais fatores de risco cardio-vasculares e história de colecistectomia. Todos estes fatores de risco são facilmente detetáveis na prática clínica e podem ser de extrema importância no controlo, a curto e longo prazo, do cancro colorretal pós-colonoscopia.

Predicting residual neoplasia after a non-curative gastric ESD: validation and modification of the eCura system in the Western setting: the W-eCura score.

OBJECTIVE: To evaluate the risk factors for lymph node metastasis (LNM) after a non-curative (NC) gastric endoscopic submucosal dissection (ESD) and to validate and eventually refine the eCura scoring system in the Western setting. Also, to assess the rate and risk factors for parietal residual disease. DESIGN: Retrospective multicentre multinational study of prospectively collected registries from 19 Western centres. Patients who had been submitted to surgery or had at least one follow-up endoscopy were included. The eCura system was applied to assess its accuracy in the Western setting, and a modified version was created according to the results (W-eCura score). The discriminative capacities of the eCura and W-eCura scores to predict LNM were assessed and compared. RESULTS: A total of 314 NC gastric ESDs were analysed (72% high-risk resection (HRR); 28% local-risk resection). Among HRR patients submitted to surgery, 25% had parietal disease and 15% had LNM in the surgical specimen. The risk of LNM was significantly different across the eCura groups (areas under the receiver operating characteristic curve (AUC-ROC) of 0.900 (95% CI 0.852 to 0.949)). The AUC-ROC of the W-eCura for LNM (0.916, 95% CI 0.870 to 0.961; p=0.012) was significantly higher compared with the original eCura. Positive vertical margin, lymphatic invasion and younger age were associated with a higher risk of parietal residual lesion in the surgical specimen. CONCLUSION: The eCura scoring system may be applied in Western countries to stratify the risk of LNM after a gastric HRR. A new score is proposed that may further decrease the number of unnecessary surgeries.

Recovering from a renal vascular catastrophe: Case report.

Renal artery thrombosis is a rare vascular event that precipitates renal infarction. Although in up to one third of cases the etiology is not identified, renal artery lesions, cardioembolism and acquired thrombophilias are the main causes. A bilateral simultaneous idiopathic renal artery thrombosis is an unlikely coincidence. We present two cases of patients with acute bilateral renal artery thrombosis of unknown etiology. Cardiac embolism, acquired thrombophilia and occult neoplasm workups were negative. Both cases were temporarily hemodialysis-dependent and partially recovered renal function under conservative approach with systemic anticoagulation. Recommendations on optimal treatment for renal artery thrombosis are still lacking. We discuss the available options.

Activation of an actin signaling pathway in pre-malignant mammary epithelial cells by P-cadherin is essential for transformation.

Alterations in the expression or function of cell adhesion molecules have been implicated in all steps of tumor progression. Among those, P-cadherin is highly enriched in basal-like breast carcinomas, playing a central role in cancer cell self-renewal, collective cell migration and invasion. To establish a clinically relevant platform for functional exploration of P-cadherin effectors in vivo, we generated a humanized P-cadherin Drosophila model. We report that actin nucleators, Mrtf and Srf, are main P-cadherin effectors in fly. We validated these findings in a human mammary epithelial cell line with conditional activation of the SRC oncogene. We show that, prior to promoting malignant phenotypes, SRC induces a transient increase in P-cadherin expression, which correlates with MRTF-A accumulation, its nuclear translocation and the upregulation of SRF target genes. Moreover, knocking down P-cadherin, or preventing F-actin polymerization, impairs SRF transcriptional activity. Furthermore, blocking MRTF-A nuclear translocation hampers proliferation, self-renewal and invasion. Thus, in addition to sustaining malignant phenotypes, P-cadherin can also play a major role in the early stages of breast carcinogenesis by promoting a transient boost of MRTF-A-SRF signaling through actin regulation.

Shelf-Life Performance of Fish Feed Supplemented with Bioactive Extracts from Fermented Olive Mill and Winery By-Products.

Fortifying fish feeds with bioactive compounds, such as enzymes and antioxidants, has been an adopted strategy to improve feed nutritional quality and sustainability. However, feed additives can lose activity/effectiveness during pelleting and storage processes. This work aimed to monitor functional activity stability in feeds supplemented with a bioactive extract, including cellulases, xylanases, and antioxidants. This bioactive extract (FBE) was produced by Aspergillus ibericus under solid-state fermentation of olive mill and winery by-products. Two isoproteic and isolipidic diets were formulated and unsupplemented or supplemented with lyophilized FBE (0.26% w/w). Both diets were stored at room temperature (RT) or 4 °C for 4 months. Results showed that feed storage at 4 °C enhanced the stability of the enzymes and cellulase was more stable than xylanase. Compared to RT, storage at 4 °C increased cellulase and xylanase half-life by circa 60 and 14%. Dietary FBE supplementation increased antioxidant activity and storage at 4 °C reduced antioxidant activity loss, while in the unsupplemented diet, antioxidant activity decreased to the same level in both storage temperatures. Dietary supplementation with FBE reduced lipid peroxidation by 17 and 19.5% when stored at 4 °C or RT, respectively. The present study is a step toward improving the storage conditions of diets formulated with bioactive compounds.

Endoscopic ampullectomy of a giant pedunculated ampullary adenoma.

The authors present a case of a 72-year-old woman with a personal history of arterial hypertension, dyslipidemia and gallstones. For suspected choledocholithiasis, a MR-Cholangiopancreatography was performed, which revealed the presence of an endoluminal polypoid structure in the third duodenal portion.

A rare cause of obscure gastrointestinal bleeding.

A 62-year-old woman was referred to Gastroenterology appointment due to severe iron deficiency anemia (5.9 g/dL), complaining of asthenia and requiring blood transfusion. The patient denied blood loss. Initial blood test showed a severe iron deficiency, with ferritin of 5ng/mL and transferrin saturation of 2.7%. Folic acid and vitamin B12 were normal. Upper gastroscopy and colonoscopy didn't show any lesions. Abdominopelvic CT and capsule endoscopy were, also, normal.

An uncommon colonic polyp.

A 50-year-old male was referred to a Gastroenterology appointment after a screening colonoscopy with a 25mm exophytic lesion, with a depressed central area, on the transverse colon. Histologic examination of the biopsy specimen showed low-grade dysplasia. The patient was submitted to a new colonoscopy and what was seen was a flat lesion with central depression, with no lift-sign (Figure 1a and 1b) and, therefore, endoscopic resection was not performed. New endoscopic biopsies were taken and showed no dysplasia.

Esophagopleural fistula due to empyema necessitans.

Empyema necessitans is a rare entity that consists on the development of an abscess that begins in the pleural space and then extends to the adjacent tissues. This case shows a rare and very late complication of a total pneumonectomy, emphasizing the importance of the multidisciplinary approach and the potential of endoscopic therapy with over-the-scope clips.

Terminal ileitis - When all factors come together.

A 45-year-old male, with a recent surgery for odontoid fracture, presented to the emergency department with a 15-days history of abdominal pain associated with fever and weight loss. He reported a recent history of antibiotic therapy due to respiratory infection and a frequent use of anti-inflammatory drugs (NSAIDs) in the last three months.