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1.
J Am Coll Radiol ; 14(5S): S282-S292, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28473085

RESUMO

Women and health care professionals generally prefer intensive follow-up after a diagnosis of breast cancer. However, there are no survival differences between women who obtain intensive surveillance with imaging and laboratory studies compared with women who only undergo testing because of the development of symptoms or findings on clinical examinations. American Society of Clinical Oncology and National Comprehensive Cancer Network guidelines state that annual mammography is the only imaging examination that should be performed to detect a localized breast recurrence in asymptomatic patients; more imaging may be needed if the patient has locoregional symptoms (eg, palpable abnormality). Women with other risk factors that increase their lifetime risk for breast cancer may warrant evaluation with breast MRI. Furthermore, the quality of life is similar for women who undergo intensive surveillance compared with those who do not. There is little justification for imaging to detect or rule out metastasis in asymptomatic women with newly diagnosed stage I breast cancer. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.


Assuntos
Doenças Assintomáticas , Neoplasias da Mama/diagnóstico por imagem , Mamografia , Recidiva Local de Neoplasia/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Qualidade de Vida , Radiologia , Fatores de Risco , Sociedades Médicas , Tomografia Computadorizada por Raios X/métodos , Estados Unidos
2.
J Am Coll Radiol ; 13(11S): e43-e52, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27814823

RESUMO

Women newly diagnosed with stage 1 breast cancer have an early-stage disease that can be effectively treated. Evidence provides little justification for performing imaging to exclude metastasis in asymptomatic women with stage I breast cancer. No differences have been found in survival or quality of life in women regardless of whether they underwent initial workup for metastatic disease. These women generally prefer intensive follow-up to detect an early recurrence. However, survival rates do not differ between women who obtain intensive screening and surveillance, with imaging and laboratory studies, and women who undergo testing only as a result of development of symptoms or findings on clinical examinations. In addition, quality of life is similar for women who undergo intensive surveillance compared with those who do not. American Society of Clinical Oncology and National Comprehensive Cancer Network guidelines state that annual mammography is the only imaging examination that should be performed to detect a localized breast recurrence in asymptomatic patients. Additional imaging may be needed if the patient has locoregional symptoms. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review by the panel include extensive analysis of current medical literature from peer-reviewed journals and application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures. When evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Detecção Precoce de Câncer/normas , Mamografia/normas , Metástase Neoplásica/diagnóstico por imagem , Recidiva Local de Neoplasia/diagnóstico por imagem , Doenças Assintomáticas , Medicina Baseada em Evidências , Feminino , Humanos , Oncologia/normas , Metástase Neoplásica/patologia , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Guias de Prática Clínica como Assunto , Radiologia/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Vigilância de Evento Sentinela , Estados Unidos
3.
J Am Coll Radiol ; 11(12 Pt A): 1160-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25444069

RESUMO

Women newly diagnosed with stage 1 breast cancer have an early-stage disease that can be effectively treated. Evidence provides little justification for performing imaging to exclude metastasis in asymptomatic women with stage I breast cancer. No differences have been found in survival or quality of life in women regardless of whether they underwent initial workup for metastatic disease. These women generally prefer intensive follow-up to detect an early recurrence. However, survival rates do not differ between women who obtain intensive screening and surveillance, with imaging and laboratory studies, and women who undergo testing only as a result of development of symptoms or findings on clinical examinations. In addition, quality of life is similar for women who undergo intensive surveillance compared with those who do not. American Society of Clinical Oncology and National Comprehensive Cancer Network guidelines state that annual mammography is the only imaging examination that should be performed to detect a localized breast recurrence in asymptomatic patients. Additional imaging may be needed if the patient has locoregional symptoms. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review by the panel include extensive analysis of current medical literature from peer-reviewed journals and application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures. When evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.


Assuntos
Detecção Precoce de Câncer/normas , Mamografia/normas , Recidiva Local de Neoplasia/patologia , Vigilância da População/métodos , Guias de Prática Clínica como Assunto , Radiologia/normas , Feminino , Humanos , Oncologia/normas , Gradação de Tumores , Metástase Neoplásica , Estados Unidos , Saúde da Mulher/normas
4.
J Mol Med (Berl) ; 90(1): 81-8, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21894551

RESUMO

Biotin (vitamins H and B7) is an important micronutrient as defects in its availability, metabolism or adsorption can cause serious illnesses, especially in the young. A key molecule in the biotin cycle is holocarboxylase synthetase (HLCS), which attaches biotin onto the biotin-dependent enzymes. Patients with congenital HLCS deficiency are prescribed oral biotin supplements that, in most cases, reverse the clinical symptoms. However, some patients respond poorly to biotin therapy and have an extremely poor long-term prognosis. Whilst a small number of mutations in the HLCS gene have been implicated, the molecular mechanisms that lead to the biotin-unresponsive phenotype are not understood. To improve our understanding of HLCS, limited proteolysis was performed together with yeast two-hybrid analysis. A structured domain within the N-terminal region that contained two missense mutations was identified in patients who were refractory to biotin therapy, namely p.L216R and p.L237P. Genetic studies demonstrated that the interaction between the enzyme and the protein substrate was disrupted by mutation. Further dissection of the binding mechanism using surface plasmon resonance demonstrated that the mutations reduced affinity for the substrate through a >15-fold increase in dissociation rate. Together, these data provide the first molecular explanation for HLCS-deficient patients that do not respond to biotin therapy.


Assuntos
Biotina/metabolismo , Deficiência de Holocarboxilase Sintetase/metabolismo , Carbono-Nitrogênio Ligases/química , Carbono-Nitrogênio Ligases/isolamento & purificação , Carbono-Nitrogênio Ligases/metabolismo , Deficiência de Holocarboxilase Sintetase/genética , Humanos , Ligação Proteica , Mapeamento de Interação de Proteínas , Piruvato Carboxilase/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo
5.
Arch Biochem Biophys ; 479(2): 163-9, 2008 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-18809372

RESUMO

Biotin protein ligase (BPL) is an essential enzyme responsible for the activation of biotin-dependent enzymes through the covalent attachment of biotin. In yeast, disruption of BPL affects important metabolic pathways such as fatty acid biosynthesis and gluconeogenesis. This makes BPL an attractive drug target for new antifungal agents. Here we report the cloning, recombinant expression and purification of BPL from the fungal pathogen Candida albicans. The biotin domains of acetyl CoA carboxylase and pyruvate carboxylase were also cloned and characterised as substrates for BPL. A novel assay was established thereby allowing examination of the enzyme's properties. These findings will facilitate future structural studies as well as screening efforts to identify potential inhibitors.


Assuntos
Bioensaio/métodos , Biotina/química , Candida albicans/enzimologia , Carbono-Nitrogênio Ligases/química , Proteínas Fúngicas/química , Acetil-CoA Carboxilase/química , Acetil-CoA Carboxilase/genética , Acetil-CoA Carboxilase/metabolismo , Antifúngicos/química , Biotina/genética , Biotina/metabolismo , Candida albicans/genética , Carbono-Nitrogênio Ligases/antagonistas & inibidores , Carbono-Nitrogênio Ligases/metabolismo , Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/química , Ácidos Graxos/biossíntese , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Gluconeogênese/fisiologia , Estrutura Terciária de Proteína/fisiologia , Piruvato Carboxilase/química , Piruvato Carboxilase/genética , Piruvato Carboxilase/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
6.
Hum Mutat ; 29(6): E47-57, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18429047

RESUMO

Multiple carboxylase deficiency is a clinical condition caused by defects in the enzymes involved in biotin metabolism, holocarboxylase synthetase (HLCS) or biotinidase. HLCS deficiency is a potentially fatal condition if left untreated, although the majority of patients respond to oral supplementation of 10-20 mg/day of biotin. Patients who display incomplete responsiveness to this therapy have a poor long-term prognosis. Here we investigated cell lines from two such HLCS-deficient patients homozygous for the c.647T>G p.L216R allele. Growth of the patients' fibroblasts was compromised compared with normal fibroblasts. Also the patient cells were not sensitive to biotin-depletion from the media, and growth rates could not be restored by re-administration of biotin. The molecular basis for the HLCS deficiency was further investigated by characterisation of the p.L216R protein. The HLCS mRNA was detected in MCD and normal cell lines. However, protein and enzyme activity could not be detected in the patients' cells. In vitro kinetic analysis revealed that enzyme activity was severely compromised for recombinantly expressed p.L216R and could not be increased by additional biotin. Furthermore, the turn-over rate for the mutant protein was double that of wildtype HLCS. These results help provide a molecular explanation for the incomplete biotin-responsiveness of this p.L216R form of HLCS.


Assuntos
Carbono-Nitrogênio Ligases/genética , Deficiência de Holocarboxilase Sintetase/genética , Biotina/metabolismo , Carbono-Nitrogênio Ligases/metabolismo , Células Cultivadas , Feminino , Fibroblastos/metabolismo , Meia-Vida , Deficiência de Holocarboxilase Sintetase/metabolismo , Humanos , Recém-Nascido , Masculino , Linhagem , Samoa
7.
Am J Surg ; 184(5): 394-400, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12433600

RESUMO

BACKGROUND: Fibroadenomas commonly found by palpation and routine mammography account for approximately 20% of open surgical breast biopsies. Alternatives to open surgery include tumor removal using an automated coring device and tumor ablation using heating or cooling elements. We report our initial experience with cryoablation of biopsy-proven benign fibroadenomas. METHODS: A table-top cryoablation system employing a 2.4-mm cryoprobe was used to treat biopsy-proven benign fibroadenomas up to 4 cm in maximum diameter in a prospective nonrandomized fashion. The cryoprobe was placed under ultrasound guidance. Using a treatment algorithm based on fibroadenoma size, all tumors were subjected to two freeze cycles with an interposing thaw. Skin appearance and temperature, probe temperature, iceball size, and patient comfort were closely monitored during the procedure. Follow-up examinations including ultrasonography and photographs were scheduled for up to 12 months postablation. RESULTS: Fifty patients with 57 core biopsy-proven benign fibroadenomas were treated. Seven early cases were treated in an ambulatory surgery center setting. The remaining procedures were completely office-based using only local anesthetic. Tumor diameter varied from 7 mm to 42 mm (mean 21 mm). The iceball engulfed the target lesion in each case. Transient postoperative side effects were local swelling and ecchymosis. Postoperative discomfort rarely required medication beyond acetaminophen or ibuprofen. Lesions showed progressive shrinkage and disappearance over 3 to 12 months. No skin injury was noted and appearance remained excellent. Patient satisfaction was excellent. CONCLUSIONS: With office-based use of ultrasound-guided cryoablation for fibroadenomas there was little or no pain, target lesions were reduced in size or eliminated, scarring was minimal, cosmesis outstanding, and patient satisfaction was excellent. Cryoablation offers a useful office-based alternative to surgical excision of benign fibroadenomas.


Assuntos
Neoplasias da Mama/cirurgia , Criocirurgia/métodos , Fibroadenoma/cirurgia , Ultrassonografia de Intervenção , Adolescente , Adulto , Idoso , Assistência Ambulatorial , Anestesia Local , Biópsia , Biópsia por Agulha , Neoplasias da Mama/patologia , Feminino , Fibroadenoma/patologia , Humanos , Pessoa de Meia-Idade , Dor , Satisfação do Paciente , Resultado do Tratamento
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