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1.
Surg Clin North Am ; 101(4): 565-576, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34242600

RESUMO

Large group settings display no signs of disappearing. Most surgeons charged with this education have received no formal training. Lecturing remains the most common method of educating large groups. Even though factors required for an excellent lecture are known, their inconsistent application results in variation of effectiveness. Long-standing principles of rhetoric and recent advances in neuroscience, cognitive science, learning models, and teaching theory play a role in achieving effectiveness. This article makes recommendations for creating and delivering lectures, including active learning opportunities and modern innovations in information technology supporting teaching methods. Effective lecturing skills are acquired by persistent deliberate practice.


Assuntos
Educação de Pós-Graduação em Medicina/métodos , Cirurgia Geral/educação , Aprendizagem , Modelos Educacionais , Ensino , Humanos , Aprendizagem Baseada em Problemas , Estados Unidos
2.
Surgery ; 154(4): 739-46; discussion 746-7, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24074410

RESUMO

PURPOSE: Enhancer of zeste homologue 2 (EZH2), a component of the chromatin modification protein complex, is upregulated in pancreatic ductal adenocarcinoma (PDAC), whereas loss of p53 and its downstream target, p21(waf1/cip1), is also observed frequently. We sought to investigate the role of the p53-p21(waf1/cip1) pathway in relation to EZH2-mediated inhibition of PDAC. METHODS: The PANC-1 cell line was utilized in chromatin immunoprecipitation, gene profiling, Western blot, cell invasion, cell proliferation, and tumor xenograft assays. RESULTS: Western blot analysis with antibodies that recognize both wild-type and mutant p53 did not show any alterations in band intensity; however, antibody that detects only mutant p53 showed a band of significantly lesser intensity with EZH2 knockdown. Western blot analysis further revealed a significant upregulation of p21(waf1/cip1). Gene expression profile analysis indicated significantly enhanced transcripts of transcriptional inducers of p21(waf1/cip1), with downregulation of mutant p53 transcript, corroborating the Western blot analysis. PANC-1 cells expressing EZH2-short hairpin RNA displayed markedly attenuated growth in SCID mice. CONCLUSION: Downregulation of mutant p53 with concomitant enhanced expression of p21(waf1/cip1) and its transcriptional trans-activators may contribute toward EZH2-mediated suppression of PDAC.


Assuntos
Adenocarcinoma/genética , Carcinoma Ductal Pancreático/genética , Inibidor de Quinase Dependente de Ciclina p21/fisiologia , Genes p53/fisiologia , Neoplasias Pancreáticas/genética , Complexo Repressor Polycomb 2/fisiologia , RNA Interferente Pequeno/genética , Adenocarcinoma/patologia , Animais , Apoptose , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/genética , Elementos Facilitadores Genéticos , Proteína Potenciadora do Homólogo 2 de Zeste , Humanos , Camundongos , Neoplasias Pancreáticas/patologia , Complexo Repressor Polycomb 2/genética , Regulação para Cima
3.
Cancer Lett ; 336(1): 53-60, 2013 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-23603558

RESUMO

The enhancer of zeste homolog 2 (EZH2) methyltransferase is a transcriptional repressor. EZH2 is abnormally elevated in epithelial ovarian cancer (EOC). We demonstrated that EZH2 knockdown inhibited cell growth, activated apoptosis, and enhanced chemosensitivity. Further, silencing of EZH2 resulted in re-expression of p21(waf1/cip1) and down-regulation of mutant p53. Finally, EZH2 knockdown contributed to attenuated EOC growth in SCID mice.


Assuntos
Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Ovarianas/patologia , Complexo Repressor Polycomb 2/metabolismo , Interferência de RNA , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Inibidor de Quinase Dependente de Ciclina p21/genética , Proteína Potenciadora do Homólogo 2 de Zeste , Feminino , Humanos , Camundongos , Camundongos SCID , Mutação , Invasividade Neoplásica , Metástase Neoplásica , Transplante de Neoplasias , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias Ovarianas/genética , Complexo Repressor Polycomb 2/genética , Proteína Supressora de Tumor p53/genética
4.
Surgery ; 152(4): 704-11; discussion 711-3, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22943841

RESUMO

PURPOSE: To investigate the possibility of inhibiting the progression of pancreatic ductal adenocarcinoma (PDAC) by facilitating the expression of E-cadherin through the enforced expression of microRNA-101 (miR-101). METHODS: In situ hybridization was conducted with archival tissue using a double digoxigenin-labeled probe. Chromatin immunoprecipitation (ChIP) assay was conducted with EZ-Magna ChIPTM A. Gene profile analysis, Western blot, and immunoprecipitation assays were performed using standard protocols. RESULTS: We found that decreased miR-101 expression observed in archival patient tissues was significantly associated with poor prognosis indicated by low-intensity staining in high-grade tumors. ChIP assays using anti-enhancer of zeste homolog 2 (EZH2) antibodies indicated not only the interaction of EZH2 to the CDH1 (E-cadherin) promoter, but also that this interaction was significantly diminished in cells transfected with pre-miR-101. We observed a global downregulation of trimethylated lysine 27 of H3 histone (H3K27me3) along with upregulation of the enzymes histone deacetylase -1 and -2 with the re-expression of miR-101. Further, we observed lesser levels of transcriptional factors that inhibit the CDH1 promoter with pre-miR-101 treatment. Western blot analysis confirmed the enhanced E-cadherin expression. PANC-1 cells transduced with pre-miR-101 displayed markedly attenuated growth in SCID mice. CONCLUSION: These results suggest the potential therapeutic use of miR-101-enforced expression for inhibition of PDAC.


Assuntos
Caderinas/genética , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/terapia , MicroRNAs/uso terapêutico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/terapia , Adulto , Idoso , Animais , Antígenos CD , Apoptose/genética , Sequência de Bases , Carcinoma Ductal Pancreático/patologia , Estudos de Casos e Controles , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Feminino , Expressão Gênica , Humanos , Hibridização In Situ , Masculino , Camundongos , Camundongos SCID , MicroRNAs/genética , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Neoplasias Pancreáticas/patologia , Regiões Promotoras Genéticas , Transdução Genética , Ensaio Tumoral de Célula-Tronco , Ensaios Antitumorais Modelo de Xenoenxerto
5.
J Surg Res ; 177(2): 207-10, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22682529

RESUMO

BACKGROUND: Few data are available describing the benefits of initiating fundamentals of laparoscopic surgery (FLS) training during medical school. We hypothesized that an intense 1-month surgical skills elective that included FLS task training for fourth-year medical students (MS4s) would result in performance levels indistinguishable from graduating chief residents (PGY5) who had received clinical skill training and access to self-guided FLS curriculum. METHODS: From July 2007 through June 2011, 114 MS4s participated in a 1-month advanced surgical skills elective. The curriculum for the elective included cadaver dissections, patient management presentations, and surgical skill training (open surgical skills and basic laparoscopic skills modules performed on FLS trainers and virtual reality laparoscopic simulators). From June 2009 through June 2011, 21 PGY5s graduated who had never received formalized FLS skills training. These residents were tested on FLS by a certified proctor and the results recorded. The performance outcome measure was task completion time. Unpaired Student's t-test was used to compare the performance measures for each group. RESULTS: All PGY5s achieved FLS certification on their first attempt and completed enough cases for graduation. The MS4 group showed significantly better performance than the PGY5 group in the peg transfer and circle cut (P < 0.05). No difference was seen in the knot tying tasks between the two groups (P > 0.05) CONCLUSIONS: Incorporating FLS training into a 1 month-long medical school surgery elective enabled MS4s to achieve FLS performance similar to, or better than, the performance achieved by PGY5 surgery residents. We support the integration of FLS skills task training as a standard part of the skills training curriculum for medical students.


Assuntos
Competência Clínica , Laparoscopia/educação , Educação Médica , Humanos , Estudos Retrospectivos , Estudantes de Medicina/estatística & dados numéricos
6.
Pharm Res ; 28(12): 3079-90, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21818714

RESUMO

PURPOSE: MicroRNA-101 (miR-101) expression is negatively associated with tumor growth and proliferation in several solid epithelial cancers. Enhancer of zeste homolog 2 (EzH2) appears to be a functional target of miR-101. We explore the role of miR-101 and its interaction with EzH2 in epithelial ovarian carcinoma (EOC). METHODS: In situ hybridization (ISH) for miR-101 was performed on EOC patient tissues and normal controls. EOC cell lines were transfected with miR-101 and subjected to growth analysis and clonogenic assays. Cell motility was assessed by Boyden chamber and wound-healing assays. P21(waf1/cip1) and EzH2 interaction was assessed by Chromatin Immunoprecipitation (ChIP) assay in MDAH-2774 cells. SCID mice were assessed for tumor burden after injection with miR-101 or control vector-treated MDAH-2774 cells. RESULTS: ISH analysis revealed a decrease in miR-101 expression in EOC compared with normal tissue. MiR-101 re-expression in EOC cell lines resulted in increased apoptosis, decreased cellular proliferation, invasiveness, and reduced growth of tumor xenografts. CHIP assays revealed that re-expression of miR-101 inhibited the interaction of EzH2 with p21(waf1/cip1) promoter. CONCLUSIONS: MiR-101 re-expression appears to have antitumor effects, providing a better understanding of the role of miR-101 in EOC.


Assuntos
Cromatina/genética , Inibidor de Quinase Dependente de Ciclina p21/genética , Proteínas de Ligação a DNA/genética , MicroRNAs/genética , Neoplasias Epiteliais e Glandulares/genética , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Fatores de Transcrição/genética , Animais , Apoptose , Carcinoma Epitelial do Ovário , Linhagem Celular Tumoral , Proliferação de Células , Cromatina/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos SCID , MicroRNAs/metabolismo , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Neoplasias Epiteliais e Glandulares/metabolismo , Neoplasias Ovarianas/metabolismo , Ovário/metabolismo , Ovário/patologia , Complexo Repressor Polycomb 2 , Fatores de Transcrição/metabolismo
7.
Methods Mol Biol ; 755: 245-56, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21761309

RESUMO

Pure populations of tumor cells are essential for the identification of tumor-associated proteins for the development of targeted therapy. In recent years, laser capture microdissection (LCM) has been used successfully to obtain distinct populations of cells for subsequent molecular analysis. The polycomb group (PcG) protein, enhancer of zeste homolog 2 (EzH2), a methyl-transferase that plays a key role in -transcriptional gene repression, is frequently overexpressed in several malignant tumors. High levels of EzH2 are often associated with advanced disease stage in many solid tumors; however, its role in the pathogenesis of pancreatic ductal adeno-carcinoma (PDAC) is poorly understood. Because of the limited sample availability and the absence of in vitro amplification steps for proteins, the use of LCM for proteomics studies largely depends on highly sensitive protein detection methods. Here, we developed a faster and sensitive Western blot protocol and validated it for the detection of EzH2 in ∼2,000 cells. Initially, cultured PANC-1 cells were used to optimize protein electrophoresis and western blotting conditions. Gradient gel electrophoresis in combination with optimized antibody concentrations, and a sensitive chemiluminescent assay provided a strong signal. In order to further confirm the role of EzH2 in PDAC, employing siRNA-mediated gene silencing via long lasting plasmid vectors containing shRNA, we investigated the potential role of EzH2 gene silencing in pancreatic cancer regression. Positive correlation of EzH2 expression was observed with advanced stage, serous histology, and increasing grade in pancreatic cancer patient tissues. Further EzH2 knockdown resulted in decreased cell growth and invasiveness. The findings of this study emphasize that western blotting of a LCM-generated pure population of cancer cells may be a valuable technique for the study of tumor-specific proteins.


Assuntos
Western Blotting/métodos , Carcinoma Ductal Pancreático/metabolismo , Proteínas de Ligação a DNA/metabolismo , Lasers , Microdissecção/métodos , Neoplasias Pancreáticas/metabolismo , Fatores de Transcrição/metabolismo , Animais , Carcinoma Ductal Pancreático/patologia , Ensaios de Migração Celular/métodos , Proliferação de Células , Separação Celular/métodos , Criopreservação , Eletroforese em Gel de Poliacrilamida/métodos , Proteína Potenciadora do Homólogo 2 de Zeste , Humanos , Microtomia/métodos , Neoplasias Pancreáticas/patologia , Complexo Repressor Polycomb 2 , Ratos , Coloração e Rotulagem/métodos , Células Tumorais Cultivadas
8.
J Surg Res ; 170(1): 6-9, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21696770

RESUMO

BACKGROUND: Fundamentals of Laparoscopic Surgery (FLS) certification is a high stakes examination. The best training methods to enable successful certification are undetermined. We hypothesized that first year surgical residents (R01s) who had been pretrained as medical students would perform better during skills training than previously un-trained R01s. METHODS: This is an IRB-approved, retrospective review of FLS training data generated from a single surgical skills laboratory from July 2007 through June 2010. During the study period, there were 24 R01s with no previous FLS exposure (NOVICE group) and seven R01s who had undergone FLS task training while medical students (MS4 group). All R01s practiced the FLS skill tasks weekly for portions of the training sessions with informal feedback and teaching. Performance goals were proposed for each task based on local and national proficiency figures. The performance outcome measure was task completion time (TCT). Pretraining performance was designated iTCT and post-training fTCT. RESULTS: The MS4 group began with iTCTs for all four tasks that were significantly lower than the NOVICE iTCTs. At completion of the 16-wk training period, the MS4 group continued to demonstrate mean fTCTs that were lower for all four FLS skill tasks but only significantly for PEG, CIRCLE, and INTRA skill tasks. Both NOVICE and MS4 groups showed significant improvement for all four skill tasks (P < 0.05). CONCLUSIONS: In the current milieu of work-hour limitations, the integration of FLS skill training into medical school curriculum provided a durable advantage to the pretrained R01s, which was associated with higher levels of final performance.


Assuntos
Cirurgia Geral/educação , Internato e Residência , Laparoscopia/educação , Competência Clínica , Humanos , Estudos Retrospectivos , Faculdades de Medicina
9.
J Surg Res ; 163(1): 24-8, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20605587

RESUMO

BACKGROUND: Fundamentals of Laparoscopic Surgery (FLS) certification is reliable and valid; the American Board of Surgery requires FLS certification. Dynamics of skill retention after FLS training effect training schedules for residents. We hypothesized that the initial elevation of performance levels after FLS training would deteriorate predictably with time. METHODS: FLS performance data on 16 new surgical residents (R01s) was examined retrospectively. These R01s trained at 16 weekly sessions. Training included 4 FLS tasks, VR simulator tasks, and open surgical skills. FLS skills were practiced weekly with feedback but no instruction. Performance was tested PRE, POST, and DELAY. Outcome metrics were task completion times (TCTs). RESULTS: POST TCTs were below PRE TCTs in all R01s for all FLS tasks (P < 0.05). No difference was seen between the DELAY TCT and POST TCT for peg transfer (P = 0.726) and pattern cut (P = 0.114). The DELAY TCTs were longer than POST TCTs for extra- and intra corporeal knot-tying (P < 0.0001 and P = 0.029). Relative retention was 103% for peg transfer, 85% for pattern cut, 47% for extracorporeal knot tying, and 59% for intracorporeal knot tying. However, many individual's displayed DELAY TCT equal to or lower than POST TCT implying full retention. CONCLUSIONS: This study extends the data on FLS skill retention to an actual "production" training curriculum. This FLS training provided effective learning in R01s. Although performance levels fell across these tasks on average and for the majority of individual R01s, significant skill retention remained at 7-8 months. Early training will enable R01s to maintain or elevate skill levels with additional training sessions.


Assuntos
Internato e Residência , Laparoscopia , Retenção Psicológica , Humanos , Estudos Retrospectivos , Análise e Desempenho de Tarefas
10.
Am Surg ; 75(9): 817-21, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19774954

RESUMO

The Southeast Michigan Center for Medical Education (SEMCME) is a consortium of teaching hospitals in the Greater Detroit metropolitan area. SEMCME pools its resources for several educational means, including mock oral board examinations. The educational and cost benefits to mock oral examinations on a multi-institutional basis in preparation for the American Board of Surgery (ABS) certifying examination were analyzed. Ten-year multi-institution data from the mock oral examinations were correlated with ABS certifying examination pass rates. Mock oral examination scores were available for 107 of 147 graduates, which included 12 candidates who failed their certifying examination on the first attempt (pass rate = 89%). Four of 31 examinees who had a low score (4.9 or less) in their mock oral exams failed their certifying examination in their first attempt. The cost of running the mock examination was low (approximately $35/resident for 50 residents). When graduates from the last 10 years were surveyed, the majority of respondents believed that the mock oral examination helped in their success and with their preparation for the certifying examination. Thus, the many benefits of administering the examination with the resources of a consortium of hospitals result in the accurate reproduction of real-life testing conditions with reasonable overall costs per resident.


Assuntos
Competência Clínica/normas , Diagnóstico Bucal/métodos , Educação Médica Continuada/métodos , Cirurgia Geral/educação , Conselhos de Especialidade Profissional/organização & administração , Diagnóstico Bucal/educação , Avaliação Educacional/métodos , Hospitais de Ensino , Humanos , Estudos Retrospectivos , Inquéritos e Questionários , Estados Unidos
11.
Ann Surg Oncol ; 10(7): 734-9, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12900363

RESUMO

BACKGROUND: The benefits of primary tumor downstaging and assessment of chemoresponsiveness have resulted in expanded applications for induction chemotherapy. However, the pathologic evaluation and prognostic significance of response in preoperatively treated lymph nodes have not been defined. METHODS: The axillary lymph nodes of 71 patients with locally advanced breast cancer treated with induction chemotherapy were evaluated for histological evidence of tumor regression as defined by the presence of nodal fibrosis, mucin pools, or aggregates of foamy histiocytes. RESULTS: Complete pathologic response in the breast and axilla occurred in 10 patients (14%); 19 (26.8%) had evidence of tumor regression in 1 or more lymph nodes. Patients without nodal metastases and no evidence of tumor regression had the best outcome (median disease-free survival, 31.5 months; relapse rate, 27%). Patients with residual nodal metastases and no evidence of treatment effect had the worst outcome (median disease-free survival, 19.8 months; relapse rate, 55%). The median disease-free survival was 22.1 months, and the relapse rate was 32% for patients with histopathologic evidence of tumor regression in the axillary lymph nodes. CONCLUSIONS: Detection of treatment effect in axillary lymph nodes after induction chemotherapy identifies a subset of patients with an outcome intermediate between that of completely node-negative and node-positive patients. The axillary lymph nodes of patients receiving preoperative chemotherapy should be routinely analyzed for the presence of these features.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/tratamento farmacológico , Carcinoma Ductal de Mama/patologia , Linfonodos/patologia , Neoplasias da Mama/mortalidade , Carcinoma Ductal de Mama/mortalidade , Feminino , Fibrose , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Prognóstico , Indução de Remissão , Resultado do Tratamento
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