Telomeres and Telomerase in Neuroblastoma

Telomeres are nucleoprotein structures located at the ends of linear chromosomes. In most human adult normal somatic cells, telomeres shorten after each cellular division. This shortening ultimately leads to senescence and/or apoptosis. By contrast, in most cancer cells, telomerase activation compensates this loss and confers to these cells their infinite cell proliferation potential. Neuroblastoma (NBL) is a malignant tumor of the peripheral sympathetic nervous system and the most frequent extracranial solid tumor of childhood. NBLs are remarkably heterogeneous both at the levels of biology, genetic and clinical courses. Indeed, some of NBLs can regress spontaneously or after a mild treatment, while others are in the high-risk category with poor prognosis. The molecular bases underlying this heterogeneity are poorly understood. MYCN (V-Myc Avian Myelocytomatosis Viral Oncogene Neuroblastoma-derived Homolog) amplification, recognized as strongly associated with unfavorable patient outcome, is found in only 40% of the high-risk disease, indicating the involvement of other mechanisms. Recent observations suggest that telomerase expression and telomere dysfunctions may be one critical step in NBL development. This review provides recent insights on telomeres/telomerase regulation in NBL. Because of their involvement in the tumor cell biology, telomere and telomerase are currently at the core of new drug development

Adjunctive dexamethasone for tuberculous meningitis in HIV-positive adult

BACKGROUND Adjunctive glucocorticoids are widely used to treat human immunodeficiency virus (HIV)–associated tuberculous meningitis despite limited data supporting their safety and efficacy. METHODS We conducted a double-blind, randomized, placebo-controlled trial involving HIV-positive adults (≥18 years of age) with tuberculous meningitis in Vietnam and Indonesia. Participants were randomly assigned to receive a 6-to-8-week tapering course of either dexamethasone or placebo in addition to 12 months of antituberculosis chemotherapy. The primary end point was death from any cause during the 12 months after randomization. RESULTS A total of 520 adults were randomly assigned to receive either dexamethasone (263 participants) or placebo (257 participants). The median age was 36 years; 255 of 520 participants (49.0%) had never received antiretroviral therapy, and 251 of 484 participants (51.9%) with available data had a baseline CD4 count of 50 cells per cubic millimeter or less. Six participants withdrew from the trial, and five were lost to follow-up. During the 12 months of follow-up, death occurred in 116 of 263 participants (44.1%) in the dexamethasone group and in 126 of 257 participants (49.0%) in the placebo group (hazard ratio, 0.85; 95% confidence interval, 0.66 to 1.10; P=0.22). Prespecified analyses did not reveal a subgroup that clearly benefited from dexamethasone. The incidence of secondary end-point events, including cases of immune reconstitution inflammatory syndrome during the first 6 months, was similar in the two trial groups. The numbers of participants with at least one serious adverse event were similar in the dexamethasone group (192 of 263 participants [73.0%]) and the placebo group (194 of 257 participants [75.5%]) (P=0.52). CONCLUSIONS Among HIV-positive adults with tuberculous meningitis, adjunctive dexamethasone, as compared with placebo, did not confer a benefit with respect to survival or any secondary end point. (Funded by the Wellcome Trust; ACT HIV ClinicalTrials.gov number, NCT03092817. opens in new tab.

Fragmented understanding: exploring the practice and meaning of informed consent in clinical trials in Ho Chi Minh City, Vietnam

Background The informed consent process in clinical trials has been extensively studied to inform the development processes which protect research participants and encourage their autonomy. However, ensuring a meaningful informed consent process is still of great concern in many research settings due to its complexity in practice and interwined socio-cultural factors. Objectives This study explored the practices and meaning of the informed consent process in two clinial trials conducted by Oxford University Clinical Research Unit in collaboration with the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam. Methods We used multiple data collection methods including direct observervations, in-depth interviews with study physicians and trial participants, review of informed consent documents from 2009 to 2018, and participant observation with patients’ family members. We recruited seven physicians and twenty-five trial participants into the study, of whom five physicians and thirteen trial participants completed in-depth interviews, and we held twenty-two direct observation sessions. Results We use the concept “fragmented understanding” to describe the nuances of understanding about the consent process and unpack underlying reasons for differing understandings. Conclusions Our findings show how practices of informed consent and different understanding of the trial information are shaped by trial participants’ characteristics and the socio-cultural context in which the trials take place

Over-expression of the mitogen-activated protein kinase (MAPK) kinase (MEK)-MAPK in hepatocellular carcinoma: Its role in tumor progression and apoptosis

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignancies in South East Asia. Although activation of the MEK-MAPK is often associated with cellular growth, the role of MEK-MAPK in growth and survival of hepatocarcinoma cells has not been established. METHODS: Immuno-histochemistry was used to localize phosphorylated MAPK and MEK1/2 in the tissues. 3-(4,5-Dimethylthiazol-2-y1)-2,5-diphenyltetrazolium bromide (MTT) assay and ELISA were used to determine cell viability and cell proliferation. Deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay was used to detect apoptotic cells. Western blots analysis was performed to determine the levels of proteins involved in the MEK-MAPK and apoptotic pathways. Transfection study was performed to assess the role of MEK-MAPK pathway in growth and survival of liver cancer cells. RESULTS: We report that phosphorylation of MEK1/2 at Ser217/221 was detected by immuno-histochemistry in 100% (46 of 46) of HCCs examined. A positive signal was localized in the nuclei of hepatocarcinoma cells but not in dysplastic hepatocytes or stromal cells. Over-expression and phosphorylation of MAPK was also detected in 91% (42 of 46) and 69% (32 of 46) of HCCs examined, respectively. The percentage of cells showing positively for phosphorylated MEK1/2 increased with advancing tumor stage. In vitro, treatment of human HepG2 and Hep3B cells with MEK1/2 specific inhibitors U0126 and PD98059 led to growth inhibition and apoptosis. U0126 induced the release of cytochrome c and increased the cleavage of caspase-3, caspase-7, and poly ADP-ribose polymerase (PARP). Inhibition of phosphatidylinositol 3-kinase (PI-3K), c-Jun N-terminal kinase (JNK) and p38 kinase activities caused only a mild apoptosis in HepG2 and Hep3B cells. Activated MEK1-transfected cells were more resistant to UO126-induced apoptosis in vitro and formed larger tumors in SCID mice than mock-transfected cells. CONCLUSION: In conclusion, our results demonstrate that MEK-MAPK plays an important role in the growth and survival of liver cancer cells and suggest that blocking MEK-MAPK activity may represent an alternative approach for the treatment of liver cancer

Trouver un terrain d’entente : analyse comparative du point de vue des étudiants et de celui des enseignants sur l’utilisation des TIC

Affiche présentée dans le cadre du Colloque de l'ARC, «Des racines et des ailes pour la recherche collégiale», dans le cadre du 85e Congrès de l’Acfas, Université McGill, Montréal, les 8 et 9 mai 2017.Bien qu’il existe de nombreuses études concernant l’utilisation des technologies de l’information et de la communication (TIC) dans l’enseignement, rares sont celles qui portent à la fois sur le point de vue des étudiants et sur celui des enseignants. Pourtant, un cadre comparatif de ces deux groupes pourrait aider les cégeps à cerner les TIC qui répondent aux besoins d’apprentissage. Dans le contexte d’un projet subventionné par le Fonds de recherche du Québec – Société et culture, 311 cégépiens et 114 enseignants (nommés par leurs étudiants pour leur excellente utilisation des TIC) ont rempli un sondage de 34 questions. L’analyse comparative montre des différences (p. ex., 73 % des étudiants apprécient les télévoteurs, mais seulement 17 % des enseignants nommés les utilisent) et des similarités (p. ex., presque tous les étudiants apprécient les logiciels de présentation; plus de 90 % des enseignants les utilisent). Une utilisation pertinente des TIC par les enseignants, appuyée par les opinions des étudiants, pourrait augmenter la motivation et l’engagement de ces derniers. Notre étude pourrait générer d’autres recherches visant à comprendre pourquoi certaines TIC fonctionnent bien pour les étudiants et pourquoi d'autres, tels les examens en ligne, sont rarement utilisées par les enseignants

Diagnostyka niedoboru alfa-1-antytrypsyny we francuskim szpitalu ogólnym — przypadkowe rozpoznania czy systematyczny skrining?

WSTĘP: Poddano analizie procedurę badania przesiewowego w kierunku niedoboru alfa-1-antytrypsyny (A1AT) w Szpitalu w Nevers (Francja) oraz badań elektroforezy białek surowicy wykonanych w celu wykrycia niedoboru A1AT. MATERIAŁ I METODY: Badanie miało charakter retrospektywny. Przeanalizowano wyniki oznaczenia niedoboru alfa-1-antytrypsyny wykonanych na bezpośrednie zlecenie w okresie 3 lat oraz wyniki badań przesiewowych w kierunku niedoboru A1AT realizowanych zgodnie z międzynarodowymi rekomendacjami. Oceniono również wyniki elektroforezy białek surowicy uzyskane w tym samym okresie. WYNIKI: Na bezpośrednie badanie stężenia alfa-1-antytrypsyny skierowano 102 pacjentów, podczas gdy 1392 pacjentów spełniało wskazania do badania przesiewowego. Nie wykryto żadnego przypadku niedoboru wśród zbadanych 102 pacjentów. W tym czasie w laboratorium wykonano 5551 badań elektroforezy białek surowicy. Obniżenie frakcji alfa-1 globulin stwierdzono u 68 badanych. U 17 pacjentów oznaczono stężenie alfa-1-antytrypsyny i u 14 stwierdzono niedobór. WNIOSKI: Niedobór alfa-1-antytrypsyny częściej wykrywa się przypadkowo w badaniu elektroforezy białek surowicy niż w wyniku badania przesiewowego. Badanie niedoboru alfa-1 globulin za pomocą elektroforezy białek surowicy wydaje się wciąż najbardziej skuteczną metodą detekcji i powinno być wykonywane systematycznie. Co więcej, badaniem tą metodą powinni być objęci wszyscy pacjenci poddani badaniu skriningowemu, realizowanemu zgodnie z międzynarodowymi wytycznymi.WSTĘP: Poddano analizie procedurę badania przesiewowego w kierunku niedoboru alfa-1-antytrypsyny (A1AT) w Szpitalu w Nevers (Francja) oraz badań elektroforezy białek surowicy wykonanych w celu wykrycia niedoboru A1AT. MATERIAŁ I METODY: Badanie miało charakter retrospektywny. Przeanalizowano wyniki oznaczenia niedoboru alfa-1-antytrypsyny wykonanych na bezpośrednie zlecenie w okresie 3 lat oraz wyniki badań przesiewowych w kierunku niedoboru A1AT realizowanych zgodnie z międzynarodowymi rekomendacjami. Oceniono również wyniki elektroforezy białek surowicy uzyskane w tym samym okresie. WYNIKI: Na bezpośrednie badanie stężenia alfa-1-antytrypsyny skierowano 102 pacjentów, podczas gdy 1392 pacjentów spełniało wskazania do badania przesiewowego. Nie wykryto żadnego przypadku niedoboru wśród zbadanych 102 pacjentów. W tym czasie w laboratorium wykonano 5551 badań elektroforezy białek surowicy. Obniżenie frakcji alfa-1 globulin stwierdzono u 68 badanych. U 17 pacjentów oznaczono stężenie alfa-1-antytrypsyny i u 14 stwierdzono niedobór. WNIOSKI: Niedobór alfa-1-antytrypsyny częściej wykrywa się przypadkowo w badaniu elektroforezy białek surowicy niż w wyniku badania przesiewowego. Badanie niedoboru alfa-1 globulin za pomocą elektroforezy białek surowicy wydaje się wciąż najbardziej skuteczną metodą detekcji i powinno być wykonywane systematycznie. Co więcej, badaniem tą metodą powinni być objęci wszyscy pacjenci poddani badaniu skriningowemu, realizowanemu zgodnie z międzynarodowymi wytycznymi

Les perspectives des étudiants et des professeurs sur l’excellence dans l’utilisation des TIC et du cyberapprentissage au collégial

"Ce document est basé sur le rapport final d’un projet financé par le Fonds de recherche du Québec – Société et culture (FRQSC) et son partenaire, le ministère de l’Éducation et de l’Enseignement Supérieur (MEES) dans le cadre du programme Actions concertées Persévérance et réussite scolaires."Comprend un résumé, des références bibliographiques et des annexe

Student and professor perspectives on exemplary practices in the use of information and communication technologies (ICTs) and e-learning in colleges

"This document is based on the final report of a projet funded by the Fonds de recherche du Québec – Société et culture (FRQSC) and its partner the ministère de l’Éducation et de l’Enseignement supérieur (MEES) for the program Actions concertées Persévérance et réussite scolaires."Comprend un résumé, des références bibliographiques et des annexe

Evaluation of awake prone positioning effectiveness in moderate to severe COVID-19

Evidence mainly from high income countries suggests that lying in the prone position may be beneficial in patients with COVID-19 even if they are not receiving invasive ventilation. Studies indicate that increased duration of prone position may be associated with improved outcomes, but achieving this requires additional staff time and resources. Our study aims to support prolonged (≥ 8hours/day) awake prone positioning in patients with moderate to severe COVID-19 disease in Vietnam. We use a specialist team to support prone positioning of patients and wearable devices to assist monitoring vital signs and prone position and an electronic data registry to capture routine clinical data

Urinary catecholamine excretion, cardiovascular variability, and outcomes in tetanus

Severe tetanus is characterized by muscle spasm and cardiovascular system disturbance. The pathophysiology of muscle spasm is relatively well understood and involves inhibition of central inhibitory synapses by tetanus toxin. That of cardiovascular disturbance is less clear, but is believed to relate to disinhibition of the autonomic nervous system. The clinical syndrome of autonomic nervous system dysfunction (ANSD) seen in severe tetanus is characterized principally by changes in heart rate and blood pressure which have been linked to increased circulating catecholamines. Previous studies have described varying relationships between catecholamines and signs of ANSD in tetanus, but are limited by confounders and assays used. In this study, we aimed to perform detailed characterization of the relationship between catecholamines (adrenaline and noradrenaline), cardiovascular parameters (heart rate and blood pressure) and clinical outcomes (ANSD, mechanical ventilation required, and length of intensive care unit stay) in adults with tetanus, as well as examine whether intrathecal antitoxin administration affected subsequent catecholamine excretion. Noradrenaline and adrenaline were measured by ELISA from 24-h urine collections taken on day 5 of hospitalization in 272 patients enrolled in a 2 × 2 factorial-blinded randomized controlled trial in a Vietnamese hospital. Catecholamine results measured from 263 patients were available for analysis. After adjustment for potential confounders (i.e., age, sex, intervention treatment, and medications), there were indications of non-linear relationships between urinary catecholamines and heart rate. Adrenaline and noradrenaline were associated with subsequent development of ANSD, and length of ICU stay