Glycosylation is a key in SARS-CoV-2 infection

SARS-CoV-2 causes the respiratory syndrome COVID-19 and is responsible for the current pandemic. The S protein of SARS-CoV-2-mediating virus binding to target cells and subsequent viral uptake is extensively glycosylated. Here we focus on how glycosylation of both SARS-CoV-2 and target cells crucially impacts SARS-CoV-2 infection at different levels: (1) virus binding and entry to host cells, with glycosaminoglycans of host cells acting as a necessary co-factor for SARS-CoV-2 infection by interacting with the receptor-binding domain of the SARS-CoV-2 spike glycoprotein, (2) innate and adaptive immune response where glycosylation plays both a protective role and contributes to immune evasion by masking of viral polypeptide epitopes and may add to the cytokine cascade via non-fucosylated IgG, and (3) therapy and vaccination where a monoclonal antibody-neutralizing SARS-CoV-2 was shown to interact also with a distinct glycan epitope on the SARS-CoV-2 spike protein. These evidences highlight the importance of ensuring that glycans are considered when tackling this disease, particularly in the development of vaccines, therapeutic strategies and serological testing

Phenylethyl isothiocyanate extracted from watercress by-products with aqueous micellar systems: development and optimisation

Phenylethyl isothiocyanate (PEITC) was reported as a useful antioxidant, anti-inflammatory, and chemopreventive agent. Due to technological and stability issues, it is necessary to be able to extract PEITC from its natural matrix (watercress) through sustainable and scalable methodologies. In this article, we explored, for the first time, the extractive capacity of aqueous micellar systems (AMSs) of two non-ionic surfactants. For this, we compared the AMSs with conventional organic solvents. Furthermore, we developed and optimised a new integral PEITC production and extraction process by a multifactorial experimental design. Finally, we analysed the antioxidant capacity by the oxygen radical absorbance capacity (ORAC) and ABTS methods. As results, the AMSs were able to extract PEITC at the same level as the tested conventional solvents. In addition, we optimised by response surface methodology the integrated process (2.0% m/m, 25.0 C, pH 9.0), which was equally efective (ca. 2900 g PEITC/g watercress), regardless of the surfactant used. The optimal extracts showed greater antioxidant capacity than pure PEITC, due to other antioxidant compounds extracte in the process. In conclusion, by the present work, we developed an innovative cost-effective and low environmental impact process for obtaining PEITC extracts from watercress by-products.N/

Chitosan-olive oil microparticles for phenylethyl isothiocyanate delivery: optimal formulation

Phenylethyl isothiocyanate (PEITC), a chemopreventive compound, is highly reactive due to its considerably electrophilic nature. Furthermore, it is hydrophobic and has low stability, bioavailability and bioaccessibility. This restricts its use in biomedical and nutraceutical or food applications. Thus, the encapsulation of this agent has the function of overcoming these limitations, promoting its solubility in water, and stabilizing it, preserving its bioactivity. So, polymeric microparticles were developed using chitosan-olive oil-PEITC systems. For this, an optimisation process (factors: olive oil: chitosan ratio and PEITC: chitosan ratio) was implemented through a 3-level factorial experimental design. The responses were: the particle size, zeta-potential, polydisperse index, and entrapment efficiency. The optimal formulation was further characterised by FTIR and biocompatibility in Caco-2 cells. Optimal conditions were olive oil: chitosan and PEITC: chitosan ratios of 1.46 and 0.25, respectively. These microparticles had a size of 629 nm, a zeta-potential of 32.3 mV, a polydispersity index of 0.329, and entrapment efficiency of 98.49%. We found that the inclusion process affected the optical behaviour of the PEITC, as well as the microparticles themselves and their interaction with the medium. Furthermore, the microparticles did not show cytotoxicity within the therapeutic values of PEITC. Thus, PEITC was microencapsulated with characteristics suitable for potential biomedical, nutraceutical and food applications.info:eu-repo/semantics/publishedVersio

Expression profile of mucins (MUC2, MUC5AC and MUC6) in Helicobacter pylori infected pre-neoplastic and neoplastic human gastric epithelium

BACKGROUND: Helicobacter pylori (H. pylori) causes gastritis and intestinal metaplasia (IM) that may evolve to gastric carcinoma. The objective of this study was to compare the profile of mucins in the progressive stages of H. pylori infected pre-neoplastic and neoplastic human gastric epithelium. We used a panel of monoclonal antibodies with well-defined specificities of MUC2, MUC5AC and MUC6 to characterize the expression pattern of mucins by immunohistochemistry. METHODS: RUT and ELISA were down for H. pylori confirmation. Human gastric biopsy sections were stained using immunohistochemistry with MUC2, MUC5AC and MUC6 antibodies. RESULTS: MUC5AC was expressed in the superficial epithelium and the upper part of the gastric pits. MUC6 expression was detected in the lower part of the gastric glands. MUC2 was expressed in intestinal metaplasia, mostly in goblet cells. The mucin expression profile in the progressive stages of H. pylori infected human gastric epithelium allows the identification of intestinal metaplasia, which is characterized by a decreased expression of the gastric mucins (MUC5AC and MUC6) and de novo expression of MUC2. CONCLUSION: In conclusion, our results suggest that there is altered expression of MUC5AC and MUC6 together with the aberrant expression of MUC2 in intestinal metaplasia, during the process of gastric carcinogenesis. The present study indicates that the MUC2 mucin expression pattern is a reliable marker of intestinal metaplasia, which appears in the context of H. pylori infected individuals

Phenylethyl isothiocyanate: a bioactive agent for gastrointestinal health

The incidence of gastrointestinal pathologies (cancer in particular) has increased progressively, with considerable morbidity and mortality, and a high economic impact on the healthcare system. The dietary intake of natural phytochemicals with certain bioactive properties has shown therapeutic and preventive effects on these pathologies. This includes the cruciferous vegetable derivative phenylethyl isothiocyanate (PEITC), a bioactive compound present in some vegetables, such as watercress. Notably, PEITC has antioxidant, anti-inflammatory, bactericidal, and anticarcinogenic properties. This review summarized the current knowledge on the role of PEITC as a potential natural nutraceutical or an adjuvant against oxidative/inflammatory-related disorders in the gastrointestinal tract. We also discussed the safe and recommended dose of PEITC. In addition, we established a framework to guide the research and development of sustainable methodologies for obtaining and stabilizing this natural molecule for industrial use. With PEITC, there is great potential to develop a viable strategy for preventing cancer and other associated diseases of the gastrointestinal tract. However, this topic still needs more scientific studies to help develop new PEITC products for the nutraceutical, pharmaceutical, or food industries.info:eu-repo/semantics/publishedVersio

Sialyl Lewis x expression in canine malignant mammary tumours: correlation with clinicopathological features and E-Cadherin expression

<p>Abstract</p> <p>Background</p> <p>Sialyl Lewis x (sLe^x) antigen is a carbohydrate antigen that is considered not only a marker for cancer but also implicated functionally in the malignant behaviour of cancer cells. Overexpression of sLe^xis associated with enhanced progression and metastases of many types of cancer including those of the mammary gland. Canine mammary tumours can invade and give rise to metastases via either lymphatic or blood vessels.</p> <p>E-Cadherin is specifically involved in epithelial cell-to-cell adhesion. In cancer, E-Cadherin underexpression is one of the alterations that characterizes the invasive phenotype and is considered an invasion/tumour suppressor gene. Partial or complete loss of E-Cadherin expression correlates with poor prognosis in canine malignant mammary cancer.</p> <p>The aim of this study was to analyse the sLe^xexpression in canine malignant mammary tumours and to evaluate if the presence of sLe^xcorrelates with the expression of E-Cadherin and with clinicopathological features.</p> <p>Methods</p> <p>Fifty-three cases of canine mammary carcinomas were analysed immunohistochemically using monoclonal antibodies against sLe^x(IgM) and E-Cadherin (IgG). The clinicopathological data were then assessed to determine whether there was a correlation with sLe^xtumour expression. Double labelled immunofluorescence staining was performed to analyse the combined expression of sLe^xand E-Cadherin.</p> <p>Results</p> <p>sLe^xexpression was consistently demonstrated in all cases of canine mammary carcinomas with different levels of expression. We found a significant relationship between the levels of sLe^xexpression and the presence of lymph node metastases. We also demonstrated that when E-Cadherin expression was increased sLe^xwas reduced and vice-versa. The combined analysis of both adhesion molecules revealed an inverse relationship.</p> <p>Conclusion</p> <p>In the present study we demonstrate the importance of sLe^xin the malignant phenotype of canine malignant mammary tumours. Our results support the use of sLe^xas a prognostic tumour marker in canine mammary carcinomas. Furthermore, we showed that sLe^xand E-Cadherin expression were inversely correlated. Future studies are warranted to clarify the molecular mechanism underlying the relation between sLe^xand E-Cadherin in canine mammary carcinoma cells which represents an important comparative model to woman breast cancer.</p

Bioceramics: tendencies and perspectives of an interdisciplinary area

The need for new materials to substitute injured or damaged parts of the human body has led scientists of different areas to the investigation of bioceramics since the 70's, when other materials in use started to show implantation problems. Bioceramics show some advantages like being the material that best mimics the bone tissue but also, present low mechanical strength due to its ceramic nature. This paper presents a general view about the topic.51852

Distúrbios do equilíbrio hidroeletrolítico e do equilíbrio acidobásico: uma revisão prática

O equilíbrio hidroeletrolítico e o equilíbrio acidobásico são assuntos de importância para todas as especialidades. Porém, seu entendimento prático é, por vezes, revestido de variados graus de dificuldades. No presente texto apresenta-se o assunto apenas como uma visão prática, adquirida emmais de vinte (20) anos de ensino para estudantes, médicos residentes e médicos pósgraduandos. O texto tem apenas a pretensão didática, sem nenhuma preocupação acadêmica.Fluid, electrolyte and acid-base disorders are very important subjects for all medical specialties . But their practical learning is, sometimes, very difficult. This text intends to discuss this subject based on more than 20 years of didatic experience teaching medical students, medical residents and post-doctoral students. The text has only didatic pretensions without any academic purpose