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1.
Breast J ; 24(3): 245-252, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-28845531

RESUMO

Radiation-associated angiosarcomas (RAS) of the breast are vascular tumors arising in a previous radiation field for primary breast cancer. They occur rarely but confer a high probability of local recurrence (LR) and poor prognosis. A wide range of treatment strategies exists due to limited evidence, and although resection is the definitive treatment, LR rates remain high. It has been suggested hyperfractionated accelerated radiotherapy (HART) has the potential to prevent LR. The sarcoma group at the Juravinski Cancer Centre (JCC) reports our experience of nine patients treated with radical resection and adjuvant HART. This is one of the largest reported cohorts we are aware of to receive this treatment. The JCC pathologic data base was reviewed between the year 2006-2015 for patients with RAS. Patients who received radical surgery and immediate HART were eligible. Patients underwent radical chest wall resection and en bloc mastectomy. Radiotherapy was then delivered to 4500 cGy in 45 fractions three times daily using parallel opposed photon beams and electron patching, or volumetric modulated arc therapy. Primary outcome was recurrence-free survival in months, and records were reviewed for descriptive reports of toxicity. We compared our results to other institutions experience with surgery alone or other adjuvant therapies. Median follow-up was 19 months (range 3-41 months). One of nine patients developed LR and developed metastasis, one died of other causes, and seven are alive with no recurrent disease. There were seven reports of mild skin toxicity during treatment. One patient developed chronic wound healing complications which eventually resolved and one patient developed asymptomatic radiation osteitis of a rib. On the basis of our experience at the JCC, we recommend treatment with radical chest wall resection and adjuvant HART to prevent recurrence in RAS patients. As demonstrated in our patients, the large normal tissue volume irradiated is tolerable with in combination with small fraction sizes, and no major toxicities were seen. Further investigation into adjuvant therapy regimens and prospective studies are required to reach consensus on optimal treatment for this disease.


Assuntos
Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Hemangiossarcoma/radioterapia , Hemangiossarcoma/cirurgia , Mastectomia/métodos , Hipofracionamento da Dose de Radiação , Parede Torácica/cirurgia , Humanos , Recidiva Local de Neoplasia/cirurgia , Lesões por Radiação/radioterapia , Lesões por Radiação/cirurgia , Radioterapia Adjuvante/efeitos adversos , Resultado do Tratamento
2.
Ann Surg Oncol ; 21(7): 2181-7, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24595798

RESUMO

BACKGROUND: Gaps in breast cancer (BC) surgical care have been identified. We have completed a surgeon-directed, iterative project to improve the quality of BC surgery in South-Central Ontario. METHODS: Surgeons performing BC surgery in a single Ontario health region were invited to participate. Interventions included: audit and feedback (A&F) of surgeon-selected quality indicators (QIs), workshops, and tailoring interviews. Workshops and A&F occurred yearly from 2005-2012. QIs included: preoperative imaging; preoperative core biopsy; positive margin rates; specimen orientation labeling; intraoperative specimen radiography of nonpalpable lesions; T1/T2 mastectomy rates; reoperation for positive margins; sentinel lymph node biopsy (SLNB) rates, number of sentinel lymph nodes; and days to receive pathology report. Semistructured tailoring interviews were conducted to identify facilitators and barriers to improved quality. All results were disseminated to all surgeons performing breast surgery in the study region. RESULTS: Over 6 time periods, 1,828 BC charts were reviewed from 12 hospitals (8 community and 4 academic). Twenty-two to 40 participants attended each workshop. Sustained improvement in rates of positive margins, preoperative core biopsies, specimen orientation labeling, and SLNB were seen. Mastectomy rates and overall axillary staging rates did not change, whereas time to receive pathology report increased. The tailoring interviews concerning positive margins, SLNB, and reoperation for positive margins identified facilitators and barriers relevant to surgeons. CONCLUSIONS: This surgeon-directed, regional project resulted in meaningful improvement in numerous QIs. There was consistent and sustained participation by surgeons, highlighting the importance of integrating the clinicians in a long-term, iterative quality improvement strategy in BC surgery.


Assuntos
Neoplasias da Mama/cirurgia , Mastectomia/normas , Avaliação de Resultados em Cuidados de Saúde , Padrões de Prática Médica/normas , Melhoria de Qualidade/organização & administração , Biópsia de Linfonodo Sentinela , Cirurgiões , Biópsia com Agulha de Grande Calibre , Feminino , Seguimentos , Humanos , Ontário , Indicadores de Qualidade em Assistência à Saúde
3.
J Org Chem ; 75(12): 3993-4003, 2010 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-20481604

RESUMO

The asymmetric synthesis of a range of axially chiral 2-arylpyridines by a cobalt-catalyzed [2 + 2 + 2] cycloaddition reaction is described. The use of a planar chiral (1-neomenthylindenyl)cobalt(COD) complex under photochemical conditions is the key for reacting the 1-naphthyldiynes with a range of differently functionalized nitriles, giving the enantiomeric atropoisomers with high chemical yields and enantiomeric excesses of up to 94% ee.

4.
Surg Clin North Am ; 100(1): 71-90, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31753117

RESUMO

This article provides a comprehensive evaluation of surgical management of the lymph node basin in melanoma, with historical, anatomic, and evidence-based recommendations for practice.


Assuntos
Excisão de Linfonodo/métodos , Linfonodos/cirurgia , Melanoma/patologia , Neoplasias Cutâneas/patologia , Humanos , Linfonodos/patologia , Metástase Linfática , Prognóstico , Biópsia de Linfonodo Sentinela/métodos
5.
Breast ; 32: 60-65, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28038321

RESUMO

BACKGROUND: The purpose of this study was to characterize beliefs and practice patterns for breast cancer reconstruction among physicians who treat patients with breast cancer, in order to delineate current clinical practice. This survey was administered prior to Cancer Care Ontario guideline publication. METHOD: Survey questions addressed four domains: survival, delayed or obscured recurrence detection, delayed adjuvant therapy, and aesthetics. The survey was administered to 1160 Ontario plastic and general surgeons and radiation and medical oncologists. Data were compared to published guidelines. RESULTS: The overall response rate was 48%, with 57% of respondents treating breast cancer. Of those treating breast cancer, 75% are affiliated with an academic center. Immediate breast reconstruction (IBR) is not available to 28%. Autologous reconstruction is thought to interfere with recurrence detection by 23% (oncologists 30%, surgeons 19%, p = 0.04). For patients not expected to require radiation therapy, IBR is not supported by 30%. Autologous IBR is believed to delay delivery of adjuvant chemotherapy by 45% (oncologists 55%, surgeons 41%, p = 0.02). Up to 42% of respondents believe delays in adjuvant therapy delivery following IBR are due to insufficient health care resources (ie. coordinating an oncologic and reconstructive surgeon). Radiation therapy following reconstruction is believed to have negative aesthetic outcomes, and increase the need for revision surgery. CONCLUSIONS: Unfavourable beliefs about certain clinical actions do not align with recent provincial guideline recommendations. Insufficient healthcare resources are perceived to be a significant barrier to IBR and timely care.


Assuntos
Neoplasias da Mama/psicologia , Mamoplastia/psicologia , Oncologistas/psicologia , Padrões de Prática Médica/estatística & dados numéricos , Cirurgiões/psicologia , Adulto , Atitude do Pessoal de Saúde , Neoplasias da Mama/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ontário , Inquéritos e Questionários
6.
Am J Surg ; 213(2): 418-425, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27424042

RESUMO

BACKGROUND: The study purpose was to identify tumor and surgeon predictors of local recurrence (LR), regional recurrence (RR), and distant metastasis (DM) after breast cancer (BC) surgery in a population-based cohort. METHODS: Consecutive BC surgical cases from 12 hospitals in South Central Ontario between May 2006 and October 2006 were included. Data collected on chart review included patient and tumor factors, surgery type, adjuvant treatment, surgeon specialty, surgeon case volume, and practice type. Univariate and multivariable survival analyses were performed. RESULTS: Median follow-up was 5.5 years for 402 patients (97% of sample). LR, RR, and DM occurred in 18 (4.5%), 10 (2.5%), and 47 (12%) patients, respectively. Significant predictors of BC recurrence (LR or RR or DM) were tumor size and grade, nodal status, and lymphovascular invasion on multivariable analysis. CONCLUSION: Tumor factors such as size, grade, lymphovascular invasion, and nodal status predicted BC recurrence, while practice type, surgeon specialty, and case volume did not.


Assuntos
Neoplasias da Mama/patologia , Metástase Neoplásica , Recidiva Local de Neoplasia/epidemiologia , Neoplasias da Mama/terapia , Estudos de Coortes , Feminino , Humanos , Linfonodos/patologia , Mastectomia/estatística & dados numéricos , Mastectomia Segmentar/estatística & dados numéricos , Pessoa de Meia-Idade , Gradação de Tumores , Invasividade Neoplásica , Ontário/epidemiologia , Área de Atuação Profissional/estatística & dados numéricos , Especialidades Cirúrgicas/estatística & dados numéricos
7.
Curr Med Res Opin ; 20(8): 1279-90, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15324531

RESUMO

OBJECTIVE: To evaluate the efficacy and safety of oxaprozin in comparison with diclofenac in patients with periarthritis pain of the shoulder previously unsuccessfully treated with nonsteroidal anti-inflammatory drugs other than diclofenac and oxaprozin. METHODS: In this open, multicentre, randomised, controlled study, eligible patients with periarthritis of the shoulder were randomised to receive either oxaprozin 1200 mg once daily (n = 49) or diclofenac 50 mg three times daily (n = 47). The treatment period was 15 +/- 1 days. The study was planned on a hypothesis of equivalence between the two study drugs. The primary study endpoint was the change from baseline at day 15 in the patient-assessed shoulder pain score. Secondary efficacy variables included investigator-assessed shoulder function, patient-assessed quality of life on the Short-Form-36 (SF-36) Acute Health Survey and both patients' and investigators' overall assessment of efficacy. RESULTS: At day 15, the mean changes in shoulder pain score from baseline in the oxaprozin and diclofenac groups were -5.85 +/- SD 4.62 and -5.54 +/- SD 4.41, respectively. The difference between the two groups was not statistically significant, confirming the hypothesis of the study that oxaprozin is as effective as diclofenac. Investigator-assessed shoulder function improved in both groups but more so in the oxaprozin group (p = 0.028 at day 15). Quality of life as measured by SF-36 total score was also improved in both treatment groups, with a trend toward greater improvement in the oxaprozin group. Furthermore, a significantly more favourable effect on the SF-36 'mental health' item was observed in oxaprozin compared with diclofenac-treated patients at day 15 (p = 0.0202). As assessed by investigators, the overall efficacy of oxaprozin was superior to that for diclofenac at visit 3 (8 +/- 1 days) (p = 0.0067). Patients also assessed the overall efficacy of oxaprozin as superior to that of diclofenac at visits 3 (8 +/- 1 days) (p = 0.0235) and 4 (15 +/- 1 days) (p = 0.0272). Only six adverse events, all of which were mild or moderate in intensity and occurred in four diclofenac recipients, were observed in the study. CONCLUSIONS: As expected, once-daily oxaprozin proved to be as effective as diclofenac three times daily in reducing the primary efficacy variable of patient-assessed shoulder pain score in patients with periarthritis of the shoulder refractory to previous treatments with other NSAIDs. Oxaprozin was shown to be superior to diclofenac in improving shoulder function and was considered by investigators and patients to have greater overall efficacy than diclofenac. In addition, oxaprozin showed a trend toward superior results in improving patients' quality of life compared with diclofenac. A trend towards better tolerability results for oxaprozin compared with diclofenac was also noted.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Diclofenaco/uso terapêutico , Periartrite/tratamento farmacológico , Propionatos/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oxaprozina , Medição da Dor/métodos , Periartrite/complicações , Qualidade de Vida , Autoavaliação (Psicologia) , Articulação do Ombro , Dor de Ombro/tratamento farmacológico , Dor de Ombro/etiologia , Resultado do Tratamento
8.
J Nurs Educ ; 43(2): 92-4, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14974519

RESUMO

This article describes the development and implementation of the Governor's Wellmobile program. Designed to increase access to community-based health care for uninsured, underserved populations and to provide innovative clinical practice, research, and education opportunities for students and faculty, this fleet of four full-service, primary care clinics "on wheels" is managed and operated by the University of Maryland School of Nursing, demonstrating that nurse-managed practice models are valuable to the state's health care delivery system. Issues of long-term financial sustainability are presented, as well as lessons learned about the importance of public, private, and philanthropic partnerships and political support in ensuring the success of such programs.


Assuntos
Enfermagem em Saúde Comunitária , Bacharelado em Enfermagem/organização & administração , Unidades Móveis de Saúde/organização & administração , Prática do Docente de Enfermagem/organização & administração , Atenção Primária à Saúde/organização & administração , Enfermagem em Saúde Comunitária/educação , Enfermagem em Saúde Comunitária/organização & administração , Previsões , Humanos , Maryland , Área Carente de Assistência Médica , Pessoas sem Cobertura de Seguro de Saúde , Modelos Educacionais , Modelos de Enfermagem , Objetivos Organizacionais , Escolas de Enfermagem/organização & administração
9.
J Contin Educ Nurs ; 35(5): 203-10; quiz 232-3, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15481400

RESUMO

As a result of the growing shortage of nurses and the dramatically changing role of the front-line nurse manager, leadership education for nurses is of critical importance. The purpose of the project described in this article was to design, implement, and evaluate an innovative model of nursing leadership development for students enrolled in registered nurse to bachelor of science in nursing or registered nurse to master of science in nursing programs. A guided "action-learning" course was designed that focused on both core knowledge and experiential learning. The course was developed with the assistance of an advisory panel of prominent nurse leaders with expertise in administration, health policy, informatics, and nursing education. The prototype course was offered for the first time as an elective in Spring 2003. Evaluation data indicated that the course was considered valuable by students and with modifications suggested by students, faculty, and advisory panel members, the course would be offered regularly as part of the curriculum. Recommendations also included adapting course content to a continuing education format.


Assuntos
Bacharelado em Enfermagem/organização & administração , Educação de Pós-Graduação em Enfermagem/organização & administração , Reeducação Profissional/organização & administração , Liderança , Enfermeiros Administradores , Papel do Profissional de Enfermagem , Baltimore , Currículo , Humanos , Mentores/psicologia , Modelos Educacionais , Modelos de Enfermagem , Enfermeiros Administradores/educação , Enfermeiros Administradores/organização & administração , Pesquisa em Educação em Enfermagem , Aprendizagem Baseada em Problemas/organização & administração , Competência Profissional/normas , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Autoavaliação (Psicologia) , Estudantes de Enfermagem/psicologia
10.
Stud Health Technol Inform ; 101: 113-7, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15537211

RESUMO

One goal in modern medicine is to increase the treatment quality. A major step towards this aim is to support the execution of standardized, guideline-based clinical protocols, which are used in many medical domains, e.g., for oncological chemotherapies. Standardized chemotherapy protocols contain detailed and structured therapy plans describing the single therapy steps (e.g., examinations or drug applications). Therefore, workflow management systems offer good support for these processes. However, the treatment of a particular patient often requires modifications due to unexpected infections, toxicities, or social factors. The modifications are described in the treatment protocol but not as part of the standard process. To be able to further execute the therapy workflows in case of exceptions running workflows have to be adapted dynamically. Furthermore, the physician should be supported by automated exception detection and decision support for derivation of necessary modifications. The AdaptFlow prototype offers the required support for the field of oncological chemotherapies by enhancing a workflow system with dynamic workflow adaptation and rule based decision support for exception detection and handling.


Assuntos
Protocolos Clínicos , Sistemas de Apoio a Decisões Clínicas , Oncologia , Administração dos Cuidados ao Paciente/métodos , Guias de Prática Clínica como Assunto , Humanos , Neoplasias/tratamento farmacológico
11.
Nurs Leadersh Forum ; 8(1): 34-9, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14649130

RESUMO

For more than two decades, nursing educators and administrators have grappled with issues of declining student enrollments and the concurrent "defection" of nurses from the labor market. This article describes both short- and long-term strategies for addressing the nursing shortage and identifies new opportunities for collaboration in building the nursing workforce of the future.


Assuntos
Recursos Humanos de Enfermagem/provisão & distribuição , Seleção de Pessoal/organização & administração , Atitude do Pessoal de Saúde , Escolha da Profissão , Comportamento Cooperativo , Diversidade Cultural , Humanos , Relações Interprofissionais , Liderança , Manobras Políticas , Marketing , Avaliação das Necessidades , Enfermeiros Administradores/educação , Enfermeiros Administradores/organização & administração , Enfermeiros Administradores/psicologia , Papel do Profissional de Enfermagem , Recursos Humanos de Enfermagem/educação , Recursos Humanos de Enfermagem/psicologia , Competência Profissional/normas , Percepção Social , Valores Sociais
12.
Am J Surg ; 208(1): 50-7, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24315382

RESUMO

BACKGROUND: The investigators designed a sustained, surgeon-directed, iterative project to improve the quality of breast cancer surgery in south central Ontario. METHODS: The strategy included audit and feedback of surgeon-selected quality indicators, workshops, and tailoring interviews. Workshops were held to discuss quality improvement strategies, select quality indicators, review audited results, and select interventions for subsequent implementation. Semistructured tailoring interviews were conducted to identify facilitators and barriers to improved quality. All presentations and results were disseminated to all surgeons performing breast surgery in the study region. RESULTS: Forty-four surgeons performing breast surgery across 12 hospitals are involved in the project. Five workshops have been held since 2005. Surgeons' enthusiasm and involvement in the project have been positive. Interim results demonstrated that over 4 audit cycles (2006-2010), the preoperative core biopsy rate increased from 73% to 92%. The tailoring interviews indicated that 18 of 21 surgeons performed preoperative core biopsies. CONCLUSIONS: This project highlights the feasibility of a surgeon-directed, iterative quality improvement strategy in breast cancer surgery. Interim results demonstrate consistent improvements in a key selected quality indicator.


Assuntos
Neoplasias da Mama/cirurgia , Cuidados Intraoperatórios/normas , Mastectomia/normas , Padrões de Prática Médica/normas , Cuidados Pré-Operatórios/normas , Melhoria de Qualidade/organização & administração , Atitude do Pessoal de Saúde , Biópsia com Agulha de Grande Calibre/normas , Biópsia com Agulha de Grande Calibre/estatística & dados numéricos , Educação Médica Continuada , Feminino , Humanos , Entrevistas como Assunto , Cuidados Intraoperatórios/educação , Cuidados Intraoperatórios/métodos , Cuidados Intraoperatórios/estatística & dados numéricos , Mastectomia/educação , Mastectomia/métodos , Auditoria Médica , Oncologia/educação , Ontário , Avaliação de Resultados em Cuidados de Saúde , Padrões de Prática Médica/estatística & dados numéricos , Cuidados Pré-Operatórios/educação , Cuidados Pré-Operatórios/métodos , Cuidados Pré-Operatórios/estatística & dados numéricos , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Indicadores de Qualidade em Assistência à Saúde , Estudos Retrospectivos
13.
Am J Surg ; 205(6): 703-10, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23465329

RESUMO

BACKGROUND: This study examined the impact of intraoperative digital specimen mammography (IDSM) compared with conventional specimen radiography (CSR) for nonpalpable breast lesions in patients undergoing breast-conserving surgery (BCS). METHODS: In this retrospective cohort study, 201 consecutive image-detected nonpalpable breast lesions underwent BCS after preoperative localization and specimen radiography. Data on patient, tumor, and surgical factors were collected. RESULTS: CSR was performed in 105 patients and IDSM was used in 96 patients. Patient and tumor factors were similar in both groups. Using univariate analysis, CSR resulted in more positive margins (19% vs 6.2%; P = .012). Rates of cavity margin resection, reoperation, and operative times were similar for CSR and IDSM. Independent predictors of positive margins on multivariable analysis were use of CSR, microcalcifications on mammography, the need for bracketing for localization, and no cavity margin excision (all P < .05). CONCLUSIONS: In this study, the use of IDSM resulted in fewer positive margins after BCS, although operative times were similar.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/cirurgia , Cuidados Intraoperatórios , Mamografia/métodos , Intensificação de Imagem Radiográfica , Calcinose , Carcinoma Ductal de Mama/diagnóstico por imagem , Carcinoma Ductal de Mama/cirurgia , Carcinoma Lobular/diagnóstico por imagem , Carcinoma Lobular/cirurgia , Estudos de Coortes , Feminino , Humanos , Mastectomia Segmentar , Pessoa de Meia-Idade , Análise Multivariada , Duração da Cirurgia , Reoperação , Estudos Retrospectivos
14.
Cancer Chemother Pharmacol ; 68(3): 661-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21125276

RESUMO

PURPOSE: Adjuvant therapy reduces the risk of recurrence of breast cancer. This study was undertaken to determine characteristics guiding choice of adjuvant therapy. METHODS: A retrospective review was completed of characteristics of patients with breast cancer (stages I-III) at a regional center from 2004 to 2007. Univariate analysis was used to select factors (P < 0.1) for entry into multivariate stepwise logistic regressions. Odds ratios with 95% confidence intervals were calculated. A P value of <0.05 was significant, and comparisons were two-tailed. RESULTS: Model 1 (n = 744) assessed the prescription of any adjuvant regimen (hormonal or chemotherapy). Indicators of choice of any regimen were positive lymph nodes [OR 16.5, CI (6.2, 44.0)], grade [4.0, (2.5, 6.0)], size [3.2, (2.1, 4.6)], PR [0.3, (0.1, 0.6)], and multicentricity [0.2 (0.04, 0.66)]. Model 2 (n = 663) assessed chemotherapy in ER+ patients. Indicators of addition of chemotherapy were stage [8.9 (4.3, 18.6), grade [5.5 (3.1, 9.6)], positive nodes [2.7 (1.1, 6.4)], physician experience [1.1 (1.0, 1.2)], age [0.8 (0.79, 0.86)], and year of treatment [0.8, (0.4, 0.9)]. Model 3 (n = 867) assessed prescription of a more aggressive chemotherapy regimen and indicators were treatment by a breast specialist oncologist [8.6 (1.7, 43.1)], stage [3.6 (2.4, 5.4)], positive nodes [2.6 (1.7, 4.1)], year of treatment [1.5 (1.3, 1.8)], size [1.2 (1.1, 1.4)], age [0.91 (0.89, 0.93)], and PR [0.4 (0.3, 0.6)]. CONCLUSIONS: This study verifies known factors for choice of adjuvant therapy, excludes others thought to be important, and quantifies effects at our center. Further studies are required to compare these models where risk stratification is different.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Quimioterapia Adjuvante , Adulto , Idoso , Envelhecimento/fisiologia , Antineoplásicos/uso terapêutico , Antineoplásicos Hormonais/uso terapêutico , Inibidores da Aromatase/uso terapêutico , Terapia Combinada , Estudos Transversais , Feminino , Hormônios/uso terapêutico , Humanos , Modelos Logísticos , Linfonodos/patologia , Pessoa de Meia-Idade , Modelos Estatísticos , Recidiva Local de Neoplasia/prevenção & controle , Razão de Chances , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Análise de Regressão , Estudos Retrospectivos , Medição de Risco , Tamoxifeno/uso terapêutico
17.
Chem Soc Rev ; 36(7): 1085-94, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17576476

RESUMO

Cycloaddition reactions compose one of the most important classes of reactions when it comes to the simultaneous formation of several bonds in one reaction step. The de novo construction of carbocyclic aromatic systems from acetylenes was also found as an excellent possibility for the assembly of heteroaromatic systems. The transition metal-catalysed [2 + 2 + 2] cycloaddition reaction constitutes a fascinating tool for the synthesis of pyridines from nitriles and the most recent developments demonstrate the ability to control the substitution pattern as well as the possibility of introducing chirality by the use of achiral substrates and a chiral catalyst under mild conditions. In this tutorial review we are focusing on the de novo construction of pyridine ring systems by the transition metal-catalysed [2 + 2 + 2] cycloaddition reaction. After surveying the mechanistic features and intermediates of the reaction depending on the different metal complexes used, we depict the preparation of achiral pyridine derivatives. The last section describes the advances in the synthesis of chiral pyridines and biaryls using the cyclotrimerization method. The various possibilities of introducing chirality by catalytic means are presented and illustrated by instructive examples. This review will be of interest for people active in: Organic Chemistry, Organometallic Chemistry, Transition Metal Chemistry, Stereoselective Synthesis, Heterocyclic Chemistry.

18.
Chemistry ; 13(4): 1117-28, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17068833

RESUMO

A novel and efficient, two-step route to axially chiral biaryls is demonstrated. In a direct asymmetric cross-cyclotrimerization in the presence of a chiral cobalt(I) catalyst, axially chiral biaryls bearing phosphoryl moieties have been prepared, and through indirect evidence the authors have been able to clarify the origin of the stereochemical induction and the nature of the central intermediate in the catalytic cycle. By subsequent reduction of the phosphoryl moiety to the corresponding phosphine, a very efficient and atom-economical approach to chiral systems has been developed. These chiral systems clearly have great potential use as axially chiral monodentate P- or bidentate P,O-ligands, as has been demonstrated by the employment of the novel NAPHEP as a new monodentate acting ligand in an asymmetric hydrosilylation reaction.

19.
Org Biomol Chem ; 5(9): 1397-404, 2007 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-17464409

RESUMO

This work reports the synthesis of new axially chiral bridged 2,2'-bipyridines 1 and pyridylmonooxazolines (pymox) 2. The potential of these new axially chiral N,N-ligands was evaluated in asymmetric catalytic cyclopropanation of styrene derivatives 22a-c with diazoesters 21a,b. While 2,2'-bipyridines 1a-c afforded the corresponding cyclopropanes 23a-f in up to 65% ee, pymoxs 2a-e gave somewhat lower enantioselectivities (up to 53% ee). Both classes of ligands produced trans-cyclopropanes 23a-f as the major isomer, although with modest diasteroselectivities (56 : 44 to 78 : 22). A structure-stereoselectivity relationship study of ligands 1 and 2 identified the chiral biaryl axis as being mostly responsible for the enantioselective performances of these ligands.

20.
J Org Chem ; 67(13): 4414-22, 2002 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-12076136

RESUMO

The photocatalyzed [2 + 2 + 2]-cycloaddition of nitriles with 2 equiv of acetylene to 2-pyridines can be carried out under mild conditions and represents a valuable extension to common synthetical methods. For the ideal wavelength range (350-500 nm), lamps as well as sunlight can be used. Working at room temperature and in organic solvents such as toluene or hexane as well as in water gives satisfying results in many cases. However, it is also possible to vary the solvent and the reaction temperature of the photocatalyzed synthesis and to choose, with respect to the specific substrate, specific requirements for this particular reaction and general requirements of the method. This simple and selective method derives its potential mainly from the large variety of applicable nitriles. Suitable substrates include (functionalized) aliphatic and aromatic nitriles as well as cyanamides derived from secondary amines.

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