Clinical and Investigative Medicine最新文献

The Clinician Investigator Trainee Association of Canada (CI) trainees across the country around the common goal of improving training conditions for those pursuing a career at the junction of research and medicine. Since then, the CI training landscape has shifted dramatically. The number of Canadian CI trainees enrolled totaling 289 MD-PhD trainees and 389 Clinical Investigator Program (CIP) trainees as of 2019 [1]. Alumni outcome data have presented conclusive evidence that MD-PhD training programs are effective in producing CI careers [2-4].

Background: Pulmonary fibrosis (PF) is associated with reduction in vital capacity (VC) and increase in expiratory flow rates, including peak expiratory flow (PEF). Full pulmonary function testing and computed tomography chest scans are limited resources in some geographic areas and a simple and sensitive screening test would be of value. We hypothesized that increase in the ratio of % predicted PEF over % predicted VC (%PEF/%VC), from spirometry alone might be sensitive to screen for pulmonary fibrosis.

Methods: The %PEF/%VC from 1,000 consecutive spirometric flow volume curves was nearly normally distributed: 7.5% (approximately 1.5 standard deviations) had a ratio ≥ 1.4. We evaluated the sensitivity and specificity of this cut point for a diagnosis of PF in a retrospective chart review of 391 patients with good quality spirometry and respirologists' confirmed diagnoses.

Results: Of the 391 patients analyzed, 98 had PF, 79 were normal, 70 had a combined obstructive and restrictive processes, 57 had obstructive lung disease, 61 had extra-parenchymal restriction and 26 had non-fibrotic interstitial lung disease. A %PEF/%VC ≥ 1.4 was only 54.1% sensitive in predicting PF, however it had a specificity of 94.9%. There was a 95.1% specificity for ruling in intra-parenchymal opposed to extra-parenchymal restriction.

Conclusion: A %PEF/%VC ≥ 1.4 was not sensitive enough to screen for PF but did demonstrate high specificity and thus may be helpful in identifying intraparenchymal restriction.

On November 8th, 2019, the Cumming School of Medicine at the University of Calgary hosted the 11th annual Leaders in Medicine (LIM) Research Symposium. Dr. Donald A. Redelmeier, Professor at the University of Toronto and Canada Research Chair in Medical Decision Sciences, served as the keynote speaker with a talk entitled "Pitfalls of Reasoning and Clinical Medicine". In addition, there were five oral and 64 poster presentations. These presentations covered topics ranging from health promotion to neuroimaging. The event celebrated the continuing success and diversity of the LIM program and the training of clinician-scientists at the University of Calgary.

Purpose: Magnesium-based alloy scaffold is a promising biodegradable stent due to its intrinsic mechanical performance and biocompatibility. Based on our preliminary experiments, we designed a novel sirolimus-eluting magnesium-based alloy scaffold. This work aimed to assess its safety and degradation performance in vivo.

Methods: The scaffolds were implanted in the lower limb arteries of Bama mini-pigs. Safety was defined as no immediate thrombosis or >30% residual stenosis, which was assessed with optical coherence tomography and digital subtraction angiography. Blood biochemical analyses were performed to evaluate hepatorenal toxicity. The degradation process of the scaffolds, the endothelialization, and lumen loss of the stented-vessels were detected with scanning electron microscopy, immunohistochemical, hematoxylin-eosin staining and optical coherence tomography.

Results: Twenty-four scaffolds were successfully implanted in six pigs with no signs of immediate thrombosis or >30% residual stenosis. The scaffolds were covered by endothelium at one month and absolutely resorbed at six months post implantation. Blood analysis showed that the hepatorenal function except for alanine aminotransferase and γ-glutamyl transpeptidase was normal. Obvious intimal hyperplasia and lumen loss were found in the stented vessels at three months, while the diameters and inner lumen areas of stented segments had increased significantly at six months (p.

Professor Sir Mark Walport, FRS, FMed Sci, FRCP, physicianscientist, academic leader and visionary health research planner, was the recipient of the 2020 Henry G. Friesen International Prize in Health Research. He is a former Chief Executive, UK Research and Innovation (UKRI) and UK government's Chief Scientific Advisor. He continues to be a champion of fundamental science in health research, engineering, technology and innovation, and is a major spokesperson on COVID-19 pandemic trends at the global level.

Purpose: Despite advances in our understanding of the roles of the long noncoding RNA (lncRNA) tumor suppressor candidate 7 (TUSC7) in cancer biology, which has been identified to act as a tumor suppressor by regulating cell proliferation, apoptosis, migration, invasion, cell cycle and tumor growth, its function in colorectal cancer remains unknown.

Methods: The expression levels of TUSC7 in colorectal cancer tissues and cell lines were determined, and the biological functions of TUSC7 to cancer progression in colorectal cancer were investigated via correlation analysis of clinical samples, cell viability assay, transwell assay and apoptosis analysis. Further, the molecular regulatory mechanisms of TUSC7 were demonstrated by luciferase reporter assay and western blotting.

Results: We observed that the expression of TUSC7 was markedly decreased in colorectal cancer cell lines. Moreover, the lower expression of TUSC7 was correlated with advanced clinical grades and poorer survival and may be an independent risk factor for colorectal cancer. Moreover, the expression of TUSC7 inhibited cell proliferation, invasion and epithelial-to-mesenchymal transition (EMT), while it facilitated apoptosis through competitively binding miR-23b. We also found that TUSC7 decreased the expression of phosphodiesterase 7A (PDE7A), a downstream target of miR-23b, through the TUSC7/miR-23b/PDE7A axis.

Conclusion: We demonstrated the expression of TUSC7 suppressed colorectal cancer progression through the TUSC7/miR-23b/PDE7A axis, suggesting that TUSC is a potential target for therapeutic intervention in colorectal cancer.

Purpose: As miR-34c acts as a tumor suppressant for multiple cancers, the purpose of this study was to investigate that role that miR-34c plays in the proliferation and apoptosis of lung cancer.

Methods: The expression of miR-34c in 600 patients with lung cancer was quantitatively analyzed with real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) technology and correlated to clinical pathological parameters. The CCK-8 analysis and flow cytometry were carried out to detect cell proliferation and apoptosis in miR-34c-mimic transfected cell lines. Moreover, the regulation of miR-34c to interleukin-6 (IL-6) in cell lines was detected by western blot, qRT-PCR and dual-luciferase reporter assay.

Results: The expression of miR-34c was downregulated in lung cancer compared with adjacent normal tissues. The expression level of miR-34c was linked to stromal invasion. Furthermore, overexpressing miR-34c played an active role in effectively inhibiting cell proliferation and inducing apoptosis. In addition, a significant inverse relationship was exhibited between the expression of miR-34c and IL-6 in tumor tissues.

Conclusion: At the molecular level, IL-6 can be used as a direct target of miR-34c in the treatment of lung cancer cells and miR-34c can be used as an effective biomarker and therapeutic target for lung cancer.

Purpose: Canadian clinician-scientist trainees enrolled in dual degree programs often pursue an extended training route following completion of MD and MSc or PhD degrees. However, the proportion, plans and reasoning of trainees who intend to pursue training internationally following dual degree completion has not been investigated. In this study, we assessed the international training considerations of current clinician-scientist trainees.

Methods: We designed an 11-question survey, which was sent out by program directors to all current MDPhD program and Clinician Investigator Program (CIP) trainees. Responses were collected from July 8, 2019 to August 8, 2019.

Results: We received a total of 191 responses, with representation from every Canadian medical school and both MD-PhD program and CIP trainees. The majority of trainees are considering completing additional training outside Canada, most commonly post-doctoral and/or clinical fellowships. The most common reasons for considering international training include those related to quality and prestige of training programs. In contrast, the most common reasons for considering staying in Canada for additional training are related to personal and ethical reasons. Irrespective of intentions to pursue international training, the majority of trainees ultimately intend to establish a career in Canada.

Conclusion: While most trainees are considering additional training outside of Canada due to prestige and quality of training, the majority of trainees intend to pursue a career as a clinician-scientist back in Canada. Trainees would likely benefit from improved guidance and mentorship on the value of international training, as well as enhanced support in facilitating cross-border mobility.

Purpose: The purpose of this study was to determine whether ticagrelor, a classic anti-platelet drug, has a therapeutic effect on sepsis-induced myocardial injury.

Methods: The C57BL6J mice received oral ticagrelor (10, 25 and 50 mg/kg) for seven days after which cecum ligation and puncture (CLP) were performed. An adenosine-receptor antagonist (CGS15943) was administered two hours before CLP. After 24 h, cardiac function was measured using cardiac echocardiography, then the heart and blood were collected. Hematoxylin and eosin (HE) staining and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL staining) were used to observe pathological changes and cardiomyocyte apoptosis. Plasma concentration of TNF-α, IL-6 and adenosine and myocardial tissue levels of TNF-α and IL-6 were determined. Survival analysis was performed. Western blot was used to determine the expression of a signalling protein in the myocardial tissue.

Results: The HE and TUNEL staining showed less inflammatory cell infiltration and less cardiomyocyte apoptosis in the ticagrelor group. Cardiac echocardiography showed preserved heart function in the ticagrelor group. Plasma TNF-α, IL-6 and relative expression of TNF-α and IL-6 in myocardial tissue were significantly lower in the ticagrelor group. Plasma adenosine levels were significantly higher in the ticagrelor group. Adenosine-receptor antagonists significantly blocked the protective effect of ticagrelor. Ticagrelor reduced the mortality of sepsis mice, and this reduction was blocked by the adenosine-receptor antagonist. Western blot showed that ticagrelor activated the phosphorylation of AKT and mTOR. Adenosine-receptor antagonists inhibited the activation of AKT and mTOR.

Conclusion: The protective effect of ticagrelor was dependent on adenosine-receptor activation, with downstream upregulation of phosphorylation of AKT and mTOR.