RESUMO
Reactive oxygen species (ROS) are necessary for various cellular processes. However, excess ROS cause damage to many biological molecules and therefore must be tightly regulated in time and space. Hydrogen peroxide (H2 O2 ) is the most commonly used ROS as second messenger in the cell. It is a relatively long-lived freely diffusible signaling molecule during early events of injury. In the Cnidarian hydra, injury-induced ROS production is essential for regeneration to proceed. In the present study, we have examined influence of varying exposure to H2 O2 on head and foot regeneration in the middlepieces of trisected hydra. We find that longer (4 hours) exposure to 1 mM H2 O2 inhibits both head and foot regeneration while shorter exposure (2 hours) does not. Longer exposure to H2 O2 resulted in extensive damage to DNA that could not be repaired, probably due to suboptimal induction of APE1, an enzyme necessary for base excision repair (BER). Concomitantly, genes involved in activation of Wnt pathway, necessary for head regeneration, were significantly downregulated. This appeared to be due to failure of both stabilization and transient nuclear localization of ß-catenin. Similarly, genes involved in foot regeneration were also downregulated on longer exposure to H2 O2 . Thus, exposure to excess ROS inhibits regenerative processes in hydra through reduced expression of genes involved in regeneration and diminished DNA repair.
Assuntos
Reparo do DNA/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Genes Essenciais , Hydra/efeitos dos fármacos , Peróxido de Hidrogênio/toxicidade , Regeneração/efeitos dos fármacos , Animais , Hydra/fisiologiaRESUMO
In our pursuit to develop novel non-carbohydrate small molecule Galectin-1 Inhibitors, we have designed a series of 1-benzyl-1H-benzimidazole derivatives and demonstrated their anticancer activity. The compound 6g, 4-(1-benzyl-5-chloro-1H-benzo[d]imidazol-2-yl)-N-(4-hydroxyphenyl) benzamide was found to be most potent with an IC50 of 7.01⯱â¯0.20⯵M and arresting MCF-7 cell growth at G2/M phase and S phase. Induction of apoptosis was confirmed by morphological changes like cell shrinkage, blebbing and cell wall deformation, dose dependent increase in the mitochondrial membrane potential (ΔΨm) and ROS levels. Further, dose dependent decrease in Gal-1 protein levels proves Gal-1 mediated apoptosis by 6g. Molecular docking studies were performed to understand the Gal-1 interaction with compound 6g. In addition, RP-HPLC studies showed 85.44% of 6g binding to Gal-1. Binding affinity studies by fluorescence spectroscopy and Surface Plasmon Resonance (SPR) showed that 6g binds to Gal-1 with binding constant (Ka) of 1.2â¯×â¯104â¯M-1 and equilibrium constant KD value of 5.76â¯×â¯10-4 M respectively.
Assuntos
Antineoplásicos/farmacologia , Benzimidazóis/farmacologia , Galectina 1/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Benzimidazóis/síntese química , Benzimidazóis/química , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Galectina 1/metabolismo , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Modelos Moleculares , Estrutura Molecular , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
BACKGROUND: Transcatheter aortic valve replacement (TAVR) has become a commonplace procedure for the treatment of aortic stenosis in higher risk surgical patients. With the high cost and steadily increasing number of patients receiving TAVR, emphasis has been placed on optimizing outcomes as well as resource utilization. Recently, studies have demonstrated the feasibility of conscious sedation in lieu of general anesthesia for TAVR. This study aimed to investigate the clinical as well as cost outcomes associated with conscious sedation in comparison to general anesthesia in TAVR. METHODS: Records for all adult patients undergoing TAVR at our institution between August 2012 and June 2016 were included using our institutional Society of Thoracic Surgeons (STS) and American College of Cardiology (ACC) registries. Cost data was gathered using the BIOME database. Patients were stratified into two groups according to whether they received general anesthesia (GA) or conscious sedation (CS) during the procedure. No-replacement propensity score matching was done using the validated STS predicted risk of mortality (PROM) as a propensity score. Primary outcome measure with survival to discharge and several secondary outcome measures were also included in analysis. According to our institution's data reporting guidelines, all cost data is presented as a percentage of the general anesthesia control group cost. RESULTS: Of the 231 patients initially identified, 225 (157 GA, 68 CS) were included for analysis. After no-replacement propensity score matching, 196 patients (147 GA, 49 CS) remained. Overall mortality was 1.5% in the matched population with a trend towards lower mortality in the CS group. Conscious sedation was associated with significantly fewer ICU hours (30 vs 96 hours, p = <0.001) and total hospital days (4.9 vs 10.4, p<0.001). Additionally, there was a 28% decrease in direct cost (p<0.001) as well as significant decreases in all individual all cost categories associated with the use of conscious sedation. There was no difference in composite major adverse events between groups. These trends remained on all subsequent subgroup analyses. CONCLUSION: Conscious sedation is emerging as a safe and viable option for anesthesia in patients undergoing transcatheter aortic valve replacement. The use of conscious sedation was not only associated with similar rates of adverse events, but also shortened ICU and overall hospital stays. Finally, there were significant decreases in all cost categories when compared to a propensity matched cohort receiving general anesthesia.
Assuntos
Anestesia Geral/economia , Sedação Consciente/economia , Substituição da Valva Aórtica Transcateter/economia , Idoso de 80 Anos ou mais , Anestesia Geral/métodos , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Sedação Consciente/métodos , Custos e Análise de Custo , Feminino , Humanos , Masculino , Pontuação de Propensão , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Procedimentos Cirúrgicos Torácicos/economia , Substituição da Valva Aórtica Transcateter/métodos , Resultado do TratamentoRESUMO
As percutaneous cardiac interventions continue to evolve, high-risk procedures are being performed on patients deemed too ill for surgery. What were once considered lower-risk procedures compared with open cardiac interventions may no longer be so because of the complex nature of the interventions and the complex comorbidities of the patients on whom these are being performed. We present a case involving high-risk percutaneous cardiac interventions (left main coronary angioplasty and aortic balloon valvuloplasty), facilitated by the use of extracorporeal membrane oxygenation in a critically ill patient with severe aortic stenosis, left main coronary disease, and ischemic cardiomyopathy.
RESUMO
Video is an excellent medium for medical education, both for clinicians and for the public. YouTube has emerged as one of the largest sources of freely accessible content. It is our intent to provide a preliminary discussion of the growing role of videos in medical education, sources of this video content, and the format of surgical video content on YouTube. Additionally, we will highlight the limitations and pitfalls that clinicians and the public should be aware of when viewing online video content. Several sources of both patient- and clinician-directed videos are easily accessible from the Internet and DVDs today. Medical professionals, students, and patients now have mobiles and instantaneous access to a growing collection of video content. A brief list of online video sources to view and learn dermatologic surgical techniques is provided. Given the increasing ease of creating and posting high-quality video content, this list will continue to grow, providing dermatologic surgeons with an ever-increasing wealth of visual knowledge. Although YouTube is a dominant source of publicly accessible videos, clinicians and consumers should be aware of the source and intent of the video content before accepting the content. Although it is easy to post content on YouTube, it is difficult to verify sources and the credentials of the people posting the videos. Therefore, the viewer should filter content with a discerning eye, embracing the concept of caveat emptor--or buyer beware.