Development of TNBS-induced colitis: animal model to test new pharmacological approaches

IBD is a gastro-intestinal disorder marked with chronic inflammation of intestinal epithelium, dam- aging mucosal tissue and manifests into several intestinal and extra-intestinal symptoms. Currently used medical therapy is able to induce and maintain the patient in remission, however no modifies or reverses the underlying pathogenic mechanism. The research of other medical approaches is crucial to the treatment of IBD and, for this, it ́s important to use animal models to mimic the characteristics of disease in real life. The aim of the study is to develop an animal model of TNBS-induced colitis to test new pharmacological approaches. TNBS was instilled intracolonic single dose as described by Morris et al. It was administered 2,5% TNBS in 50% ethanol through a catheter carefully inserted into the colon. Mice were kept in a Tredelenburg position to avoid reflux. On day 4 and 7, the animals were sacrificed by cervical dislocation. The induction was confirmed based on clinical symptoms/signs, ALP determination and histopathological analysis. At day 4, TNBS group presented a decreased body weight and an alteration of intestinal motility characterized by diarrhea, severe edema of the anus and moderate morbidity, while in the two control groups weren’t identified any alteration on the clinical symptoms/signs with an increase of the body weight. TNBS group presented the highest concentrations of ALP comparing with control groups. The histopathology analysis revealed severe necrosis of the mucosa with widespread necrosis of the intestinal glands. Severe hemorrhagic and purulent exsudates were observed in the submucosa, muscular and serosa. TNBS group presented clinical symptoms/ signs and histopathological features compatible with a correct induction of UC. The peak of manifestations became maximal at day 4 after induction. This study allows concluding that it’s possible to develop a TNBS- induced colitis 4 days after instillation. DII é um distúrbio gastro-intestinal caracterizado por inflamação crónica do epitélio intestinal com dano associado da mucosa, manifestando-se a partir de sintomas intestinais e extra-intestinais. A terapia médica utilizada é capaz de induzir e manter o doente em remissão, mas não modifica ou inverte o mecanismo patogénico subjacente. A procura de outras abordagens terapêuticas é crucial para o tratamento de DII e, para tal, é importante o uso de modelos animais para mimetizar as características da doença. O objetivo do estudo é desenvolver um modelo animal de colite induzida por TNBS de modo a testar novas abordagens farmacológicas. O TNBS foi instilado por via intracolónica em dose única como descrito por Morris et al. Foi administrado 2,5% de TNBS em 50% de etanol através de um cateter inserido no cólon. Os animais foram mantidos em posição Tredelenburg para evitar o refluxo. Nos dias 4 e 7, os animais foram sacrificados por deslocamento cervical. A indução de colite foi caracterizada com base nos sintomas/sinais clínicos, determinação de ALP e análise histopatológica. No dia 4, o grupo TNBS apresentou uma diminuição do peso corporal e uma alteração da motilidade intestinal caracterizada por diarreia, edema severo do ânus e morbilidade moderada, enquanto nos dois grupos controlo não foram identificados quaisquer alterações nos sintomas/ sinais clínicos com um aumento do peso corporal. O grupo TNBS apresentou as maiores concentrações de ALP, comparando com os grupos controlo. A análise histopatológica demonstrou necrose grave da mucosa com necrose generalizada das glândulas intestinais. Foi observado exsudato hemorrágico e purulento ao nível da submucosa, muscular e serosa. O grupo TNBS apresentou sintomas / sinais clínicos e características histopatológicas compatíveis com uma correta indução de colite. O pico das manifestações tornou-se máximo ao 4º dia após a indução. Este estudo permite concluir que é possível desenvolver colite induzida por TNBS 4 dias após a instilação.

VALIDAÇÃO DE PROTOCOLO ELETRÔNICO MULTIPROFISSIONAL PARA CIRURGIA DO APARELHO DIGESTIVO

Background: The creation of a computerized clinical database with the ability to collect prospective information from patients and with the possibility of rescue and crossing data enables scientific studies of higher quality and credibility in less time. Aim: To validate, in a single master protocol, the clinical data referring to Surgery of Digestive System in a multidisciplinary way, incorporating it in the SINPEâ platform, and to verify the incidence of digestive diseases based on the prospectively performed collections. Method: Organize in one software, in a standardized structure, all the pre-existing items in the SINPEâ database; the theoretical basis was computerized through the MIGRASINPEâ module creating a single multiprofessional master protocol for use as a whole. Results: The existing specific protocols were created and/or adapted – they correspond to the most prevalent digestive diseases - unifying them. The possibility of multiprofessional use was created by integrating all data collected from Medicine, Nursing, Physiotherapy, Nutrition and Health Management in a prospective way. The total was 4,281 collections, distributed as follows: extrahepatic biliary tract n=1,786; esophagus n=1015; anorectal n=736; colon n=550; small intestine n=86; pancreas n=71; stomach=23; liver n=14. Conclusions: The validation of the unification and structuring in a single master protocol of the clinical data referring to the Surgery of the Digestive System in a multiprofessional and prospective way was possible and the epidemiological study carried out allowed to identify the most prevalent digestive diseases in a tertiary university hospital.Racional: A criação de um banco de dados clínicos informatizado com a capacidade de coletar informações dos pacientes de forma prospectiva e com possibilidade de resgate e cruzamento viabiliza estudos científicos de maior qualidade e credibilidade em menor tempo. Objetivos: Validar em único protocolo mestre os dados clínicos referentes à Cirurgia do Aparelho Digestivo de forma multiprofissional incorporando-o na plataforma SINPEâ, e verificar a incidência das doenças digestivas com base nas coletas prospectivamente realizadas. Método: Organizar no software em estrutura padronizada todos os itens pré-existentes no banco de dados do SINPEâ, informatizou-se a base teórica através do módulo MIGRASINPE© criando-se um único protocolo mestre multiprofissional para uso como um todo. Resultados: Foram criados e/ou adaptados os protocolos específicos existentes - que correspondem às doenças mais prevalentes que assolam este aparelho – unificando-os. Criou-se a possibilidade de uso multiprofissional integrando todos os dados coletados da Medicina, Enfermagem, Fisioterapia, Nutrição e Gestão em Saúde de maneira prospectiva. O total foi de 4.281 coletas assim distribuídas: vias biliares extra-hepáticas n=1.786; esôfago n=1015; anorretais n=736; cólon n=550; intestino delgado n=86; pâncreas n=71; estômago=23; fígado n=14.  Conclusões: A validação da unificação e estruturação em único protocolo mestre dos dados clínicos referentes à Cirurgia do Aparelho Digestivo de forma multiprofissional e prospectiva foi possível e o estudo epidemiológico realizado permitiu identificar as doenças mais prevalentes nesse aparelho em um hospital universitário terciário

The Effect of a Linear Tuning between the Antigenic Stimulations of CD4(+) T Cells and CD4(+) Tregs

We study the equilibria of an Ordinary Differencial Equation (ODE) system where CD4+ effector or helper T cells and Regulatory T cells (Tregs) are present. T cells trigger an immune response in the presence of their specific antigen. Regulatory T cells (Tregs) play a role in limiting auto-immune diseases due to their immune-suppressive ability. Here, we present explicit exact formulas that give the relationship between the concentration of T cells, the concentration of Tregs, and the antigenic stimulation of T cells, when the system is at equilibria, stable or unstable. We found a parameter region of bistability, limited by two thresholds of antigenic stimulation of T cells (hysteresis). Moreover, there are values of the slope parameter of the tuning for which an isola-center bifurcation appears, and, for some other values, there is a transcritical bifurcation. We also present time evolutions of the ODE system

Assessment of paracetamol toxic effects under varying seawater pH conditions on the marine polychaete hediste diversicolor using biochemical endpoints

Increasing atmospheric carbon dioxide (CO2) levels are likely to lower ocean pH values, after its dissolution in seawater. Additionally, pharmaceuticals drugs are environmental stressors due to their intrinsic properties and worldwide occurrence. It is thus of the utmost importance to assess the combined effects of pH decreases and pharmaceutical contamination, considering that their absorption (and effects) are likely to be strongly affected by changes in oceanic pH. To attain this goal, individuals of the marine polychaete Hediste diversicolor were exposed to distinct pH levels (8.2, 7.9, and 7.6) and environmentally relevant concentrations of the acidic drug paracetamol (PAR: 0, 30, 60, and 120 µg/L). Biomarkers such as catalase (CAT), glutathione S-transferases (GSTs), acetylcholinesterase (AChE), and cyclooxygenase (COX) activities, as well as peroxidative damage (through thiobarbituric acid reactive substance (TBARS) quantification), were quantified to serve as ecotoxicological endpoints. Data showed a general increase in CAT and a decrease in GST activities (with significant fluctuations according to the tested conditions of PAR and pH). These changes are likely to be associated with alterations of the redox cycle driven by PAR exposure. In addition, pH levels seemed to condition the toxicity caused by PAR, suggesting that the toxic effects of this drug were in some cases enhanced by more acidic conditions. An inhibition of AChE was observed in animals exposed to the highest concentration of PAR, regardless of the pH value. Moreover, no lipid peroxidation was observed in most individuals, although a significant increase in TBARS levels was observed for polychaetes exposed to the lowest pH. Finally, no alterations of COX activities were recorded on polychaetes exposed to PAR, regardless of the pH level. The obtained results suggest that seawater acidification is detrimental to marine wildlife, since it may enhance toxic effects caused by environmental realistic concentrations of acidic drugs, such as PAR. This work was crucial to evidence that ocean acidification, in the context of a global change scenario of increased levels of both atmospheric and oceanic CO2, is a key factor in understanding the putative enhanced toxicity of most pharmaceutical drugs that are of an acidic nature.info:eu-repo/semantics/publishedVersio

Artemisinin inhibits neutrophil and macrophage chemotaxis, cytokine production and NET release

Immune cell chemotaxis to the sites of pathogen invasion is critical for fighting infection, but in life-threatening conditions such as sepsis and Covid-19, excess activation of the innate immune system is thought to cause a damaging invasion of immune cells into tissues and a consequent excessive release of cytokines, chemokines and neutrophil extracellular traps (NETs). In these circumstances, tempering excessive activation of the innate immune system may, paradoxically, promote recovery. Here we identify the antimalarial compound artemisinin as a potent and selective inhibitor of neutrophil and macrophage chemotaxis induced by a range of chemotactic agents. Artemisinin released calcium from intracellular stores in a similar way to thapsigargin, a known inhibitor of the Sarco/Endoplasmic Reticulum Calcium ATPase pump (SERCA), but unlike thapsigargin, artemisinin blocks only the SERCA3 isoform. Inhibition of SERCA3 by artemisinin was irreversible and was inhibited by iron chelation, suggesting iron-catalysed alkylation of a specific cysteine residue in SERCA3 as the mechanism by which artemisinin inhibits neutrophil motility. In murine infection models, artemisinin potently suppressed neutrophil invasion into both peritoneum and lung in vivo and inhibited the release of cytokines/chemokines and NETs. This work suggests that artemisinin may have value as a therapy in conditions such as sepsis and Covid-19 in which over-activation of the innate immune system causes tissue injury that can lead to death

A REPLICABLE OPEN-SOURCE MULTI-CAMERA SYSTEM FOR LOW-COST 4D GLACIER MONITORING

Image-based monitoring has emerged as a prevalent technique for sensing mountain environments. Monoscopic time-lapse cameras, which rely on digital image correlation to quantify glacier motion, have limitations due to the need for a Digital Elevation Model for deriving 3D flow velocity fields. Multi-camera systems overcome this limitation, as they allow for a 3D reconstruction of the scene. This paper presents a replicable low-cost stereoscopic system designed for 4D glacier monitoring. The system consists of independent and autonomous units, built from off-the-shelves components, such as a DSLR camera, an Arduino microcontroller, and a Raspberry Pi Zero, reducing costs compared to pre-built time-lapse cameras. The units are energetically self-sufficient and resistant to harsh alpine conditions. The system was successfully tested for more than a year to monitor the northwest terminus of the Belvedere Glacier (Italian Alps). Daily stereo-pairs acquired were processed with Structure-from-Motion to derive 3D point clouds of the glacier terminus and estimate glacier retreat and ice volume loss. By combining the information about ice volume loss with ablation estimates and ice flow velocity information, e.g., derived from monoscopic-camera time series, a multi-camera system enables a comprehensive understanding of sub-seasonal glacier dynamics

A novel molecular link between HOXA9 and WNT6 in glioblastoma identifies a subgroup of patients with particular poor prognosis

Despite much effort to improve treatments, patients with malignant glioma still present a very poor prognosis that has not changed significantly in the last decades. In this context, it is crucial to better understand glioma pathogenesis to identify new molecular prognostic subgroups and therapeutic targets. WNT6 was recently identified as a new oncogenic molecule in glioblastoma (GBM), with prognostic value in patients, but the mechanisms underlying WNT6 aberrant expression in glioma are still unknown. WNT6 was overexpressed in a subset of gliomas independently of IDH mutations, 1p/19q codeletion status, and WNT6 gene copy number. Interestingly, WNT6 expression is associated with the DNA methylation levels of particular CpG regions at both the WNT6 promoter and the gene body in glioma patient samples. HOXA9, a transcription factor previously associated with poorer clinical outcome in GBM, was identified as a novel transcriptional regulator of WNT6, activating the WNT/β-catenin pathway in vitro and in vivo. In various cohorts of glioma patients, mRNA levels of WNT6 and HOXA9 were significantly correlated, extending our in vitro and in vivo findings into the clinical setting. Interestingly, this novel molecular link between WNT6 and HOXA9 was not limited to glioma, as they were co-expressed also in patients with other tumor types. Clinically, WNT6 was a prognostic biomarker of shorter survival in GBM, independently of HOXA9 expression. Concomitant high expression of both WNT6 and HOXA9 identified a subgroup of patients with particularly dismal survival. These findings describe novel WNT6 regulatory mechanisms in GBM, establishing particular DNA methylation patterns and HOXA9 as critical regulators of WNT6 expression in glioma. This HOXA9-WNT6 molecular link supports WNT signaling in GBM cells and is a powerful prognostic biomarker, highlighting the clinical relevance of this axis in patients. Novel therapies targeting WNT6-HOXA9 signaling may thus be useful for this deadly disease.info:eu-repo/semantics/publishedVersio

A multicenter validation of an endoscopic classification with narrow band imaging for gastric precancerous and cancerous lesions

BACKGROUND AND STUDY AIM: The reliability and external validity of narrow band imaging (NBI) in the stomach have not been described consistently. The aim of the current study was to describe and estimate the accuracy and reliability of a simplified classification system for NBI in the diagnosis of gastric lesions. METHODS: Consecutive patients undergoing NBI endoscopy at two reference centers (n=85, 33% with dysplasia) were included in two studies. In total, 224 different areas were biopsied and recorded onto video. In the derivation study, previously described NBI features were analyzed in order to develop a simplified classification. In the validation study the accuracy and reliability of this classification were estimated among three groups of endoscopists with different levels of expertise in NBI. .RESULTS: The reliability/accuracy results from the derivation study allowed the creation of a simplified NBI classification. In the validation study, "regular vessels with circular mucosa" (pattern A) was associated with normal histology (accuracy 83%; 95% confidence interval [CI] 75?%-90%); "tubulo-villous mucosa" (pattern B) was associated with intestinal metaplasia (accuracy 84%; 95CI 77%-91%; positive likelihood ratio [LR+]=4.75); and "irregular vessels and mucosa" (pattern C) was associated with dysplasia (accuracy 95%; 95CI 90%-99%; LR+=44.33). The reproducibility of these patterns was high (k=0.62). "Light-blue crest" was moderately reliable (k=0.49) but specific (87%) for intestinal metaplasia. A variable vascular density (additional pattern+) was the best feature for Helicobacter pylori gastritis (accuracy 70%; 95CI 59%-80%) but showed only fair reliability (k=0.38). Non-experienced endoscopists presented lower agreement (k=0.6 vs. k=0.75) and accuracy (74% vs. 86%) than international experts/experienced endoscopists. CONCLUSION: A simplified NBI classification is accurate and reliable for the diagnosis of intestinal metaplasia and dysplasia. The classification should be further assessed and validated on a per-patient assessment of NBI, and by comparing NBI with other imaging technologies.This study was supported by a grant for medical investigation from the Portuguese Digestive Endoscopy Society (SPED 2009 Investigation Grant)

Ergonomics applied to the development and evaluation of insoles for protective footwear

Knowledge of ergonomics/human factors plays an important role in the creation and design of safety shoes and insoles, contributing to worker protection, comfort, and stability. The purpose of this study is to compare previous insole designs and analyze the plantar pressure and gait pattern kinematics using the Oxford foot model protocol. The tests were performed comparing the environments on the three rockers of the gait, represented by the heel, midfoot, and forefoot, according to the classification of foot type. The analysis of plantar pressure, regarding its total and maximum distribution, showed that the innovative insole presents a better load distribution in terms of the maximum plantar pressure exerted in the hindfoot and forefoot regions. In the biomechanical analysis of gait, the five variables studied did not show variation in the normal mechanics of the foot in any of the three environments considered. The hallux joint was the one that presented the greatest divergences with the barefoot in terms of amplitude and variability, as expected.SHOE@FUTURE: Technological Solutions for Professional Footwear, POCI-01-0247-FEDER-033835, co-financed by the European Regional Development Fund (FEDER) through the Competitiveness and Internationalization Operational Program under the “Portugal 2020” Program. This work has been supported by FCT—Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020