RESUMO
INTRODUCTION: Currently, bladder cancer detection is based on cytology and cystoscopy. White light cystoscopy (WLC) is an invasive procedure and may under-detect flat lesions. Blue light cystoscopy (BLC) and narrow band imaging (NBI) cystoscopy are new modalities that could improve the detection of non-muscle invasive bladder cancer (NMIBC) and its recurrence or progression to muscle invasive bladder cancer. We present a systematic review on BLC and NBI cystoscopy for bladder cancer diagnosis and NMIBC follow-up. MATERIAL AND METHODS: All available systematic reviews and meta-analyses on cystoscopy published in PubMed® between May 2010 and March 2021 were identified and reviewed. The main endpoints were clinical performance for bladder cancer diagnosis and for recurrence or progression detection during NMIBC follow-up, and additional value compared with cytology and/or WLC. RESULTS: Most of the meta-analyses and systematic reviews published suggest a better sensitivity of BLC and NBI cystoscopy compared to WLC, particularly for the detection of flat lesions (CIS). NBI- and BLC-guided TURBT could decrease the recurrence rates. However, their clinical utility to reduce progression rate and increase survival is still unclear. CONCLUSIONS: BLC and NBI cystoscopy are efficient techniques for bladder cancer diagnosis and NMIBC follow-up. However, their clinical benefit remains to be confirmed.
Assuntos
Cistoscopia , Neoplasias da Bexiga Urinária , Humanos , Cistectomia , Cistoscopia/métodos , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/patologia , Revisões Sistemáticas como Assunto , Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/patologiaRESUMO
BACKGROUND: RAS and K601E BRAF mutations are not a reliable indicator of malignancy in fine-needle aspirations (FNA) of thyroid indeterminate cytologic nodules. We aimed to evaluate the histologic characteristics, the risk of malignancy associated with such mutations in FNA and their potential interest for preoperative clinical management of nodules. METHODS: We evaluated 69 indeterminate thyroid nodules with RAS or K601E BRAF mutations with available histopathologic follow-up. All FNA specimens were indeterminate according to the thyroid Bethesda system. Diagnosis of malignant, benign or indolent neoplasms was classified according to 2017 WHO classification. Carcinoma, NIFTP (noninvasive follicular thyroid neoplasm with papillary-like features) and WDTUMP (well-differentiated tumor of uncertain malignant potential) were considered "surgical," as they require surgical excision. Adenoma was considered "non-surgical." The risk of malignancy and the risk of "surgical disease" were evaluated. RESULTS: Pathologic evaluation of the 69 mutated nodules demonstrated benign, indolent and malignant histology in 17 cases (25%), 21 cases (30%) and 31 cases (45%), respectively. The risk of malignancy was 45%, and the risk of surgical disease was 75%. The majority of carcinomas were a follicular variant of papillary thyroid carcinoma. On follow-up, there have been no recurrences to date. CONCLUSION: Preoperative RAS or BRAF K601E mutations detection in cytologic indeterminate thyroid nodules carries a high risk of surgical disease and may benefit from surgical management. Most surgical lesions harboring those mutations are low-risk tumors, which may be in favor of an initial lobectomy.
Assuntos
Biomarcadores Tumorais/genética , Tomada de Decisão Clínica/métodos , GTP Fosfo-Hidrolases/genética , Proteínas de Membrana/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Nódulo da Glândula Tireoide/genética , Tireoidectomia , Adenocarcinoma Folicular/diagnóstico , Adenocarcinoma Folicular/genética , Adenocarcinoma Folicular/patologia , Adenocarcinoma Folicular/cirurgia , Adulto , Idoso , Biópsia por Agulha Fina , Feminino , Seguimentos , Testes Genéticos , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Estadiamento de Neoplasias , Cuidados Pré-Operatórios/métodos , Período Pré-Operatório , Medição de Risco , Câncer Papilífero da Tireoide/diagnóstico , Câncer Papilífero da Tireoide/genética , Câncer Papilífero da Tireoide/patologia , Câncer Papilífero da Tireoide/cirurgia , Nódulo da Glândula Tireoide/diagnóstico , Nódulo da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/cirurgiaRESUMO
OBJECTIVE: Liquid-based (LB)-FNA is widely recognized as a reliable diagnostic method to evaluate thyroid nodules. However, up to 30% of LB-FNA remain indeterminate according to the Bethesda system. Use of molecular biomarkers has been recommended to improve its pathological accuracy but implementation of these tests in clinical practice may be difficult. Here, we evaluated feasibility and performance of molecular profiling in routine practice by testing LB-FNA for BRAF, N/HRAS and TERT mutations. METHODS: We studied a large prospective cohort of 326 cases, including 61 atypia of undetermined significance, 124 follicular neoplasms, 72 suspicious for malignancy and 69 malignant cases. Diagnosis of malignancy was confirmed by histology on paired surgical specimen. RESULTS: Mutated LB-FNAs were significantly associated with malignancy regardless of the cytological classification. Overall sensitivity was 60% and specificity 89%. Importantly, in atypia of undetermined significance and follicular neoplasm patients undergoing surgery according to the Bethesda guidelines, negative predictive values were 85.4% and 90% respectively. TERT promoter mutation was rare but very specific for malignancy (5.5%) suggesting that it could be of interest in patients with indeterminate cytology. CONCLUSIONS: Mutation profiling can be successfully performed on thyroid LB-FNA without any dedicated sample in a pathology laboratory. It is an easy way to improve diagnostic accuracy of routine LB-FNA and may help to better select patients for surgery and to avoid unnecessary thyroidectomies.
Assuntos
Mutação/genética , Proteínas Proto-Oncogênicas B-raf/genética , Telomerase/genética , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Proteínas ras/metabolismo , Adulto , Biópsia por Agulha Fina/métodos , Citodiagnóstico/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nódulo da Glândula Tireoide/patologia , Tireoidectomia/métodosRESUMO
BACKGROUND: This study evaluates the relation of the early oestrogen-regulated gene gabarapl1 to cellular growth and its prognostic significance in breast adenocarcinoma. METHODS: First, the relation between GABARAPL1 expression and MCF-7 growth rate was analysed. Thereafter, by performing macroarray and reverse transcriptase quantitative-polymerase chain reaction (RT-qPCR) experiments, gabarapl1 expression was quantified in several histological breast tumour types and in a retrospective cohort of 265 breast cancers. RESULTS: GABARAPL1 overexpression inhibited MCF-7 growth rate and gabarapl1 expression was downregulated in breast tumours. Gabarapl1 mRNA levels were found to be significantly lower in tumours presenting a high histological grade, with a lymph node-positive (pN+) and oestrogen and/or progesterone receptor-negative status. In univariate analysis, high gabarapl1 levels were associated with a lower risk of metastasis in all patients (hazard ratio (HR) 4.96), as well as in pN+ patients (HR 14.96). In multivariate analysis, gabarapl1 expression remained significant in all patients (HR 3.63), as well as in pN+ patients (HR 5.65). In univariate or multivariate analysis, gabarapl1 expression did not disclose any difference in metastasis risk in lymph node-negative patients. CONCLUSIONS: Our data show for the first time that the level of gabarapl1 mRNA expression in breast tumours is a good indicator of the risk of recurrence, specifically in pN+ patients.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/diagnóstico , Carcinoma Ductal de Mama/patologia , Proteínas Associadas aos Microtúbulos/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/genética , Carcinoma Ductal de Mama/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Linfonodos/patologia , Metástase Linfática , Proteínas Associadas aos Microtúbulos/metabolismo , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Prognóstico , Recidiva , Estudos Retrospectivos , Células Tumorais Cultivadas , Regulação para CimaRESUMO
The prognostic value of cathepsin D has been recently recognized, but as many quantitative tumor markers, its clinical use remains unclear partly because of methodological issues in defining cut-off values. Guidelines have been proposed for analyzing quantitative prognostic factors, underlining the need for keeping data continuous, instead of categorizing them. Flexible approaches, parametric and non-parametric, have been proposed in order to improve the knowledge of the functional form relating a continuous factor to the risk. We studied the prognostic value of cathepsin D in a retrospective hospital cohort of 771 patients with breast cancer, and focused our overall survival analysis, based on the Cox regression, on two flexible approaches: smoothing splines and fractional polynomials. We also determined a cut-off value from the maximum likelihood estimate of a threshold model. These different approaches complemented each other for (1) identifying the functional form relating cathepsin D to the risk, and obtaining a cut-off value and (2) optimizing the adjustment for complex covariate like age at diagnosis in the final multivariate Cox model. We found a significant increase in the death rate, reaching 70% with a doubling of the level of cathepsin D, after the threshold of 37.5 pmol mg(-1). The proper prognostic impact of this marker could be confirmed and a methodology providing appropriate ways to use markers in clinical practice was proposed.
Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Catepsina D/análise , Idoso , Neoplasias da Mama/patologia , Estudos de Coortes , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Estudos Retrospectivos , Análise de SobrevidaRESUMO
The lack of a standardized methodology for quantifying DNA ploidy and S-phase fraction (SPF) by flow cytometry is hindering routine use of these markers in breast cancer management. In a retrospective clinical multicenter study, we validated a standardized flow cytometry protocol. We tested 633 frozen T(1)T(2), N(0)N(1), M(0) breast tumors obtained in four institutions. Cell preparation was standardized, and precise rules for data interpretation were followed. Three SPF classes were defined on the basis of tertiles after adjustment for ploidy. DNA aneuploidy was observed in 61.0% of cases. No significant difference was observed among centers. Aneuploidy and high SPF were associated with large tumor size, node involvement, high histological grade, and hormone receptor negativity. In the overall population (median follow-up, 69 months), patients with medium and high SPF values had shorter disease-free survival (DFS) than those with low SPF values (P < 0.0001). Ploidy had no significant influence. By Cox analysis, SPF, pN, and estrogen receptor status were independent predictors of DFS (P = 0.0002, P = 0.001, and P = 0.05). In node-negative patients, SPF was the only predictor of DFS (P = 0.01), whereas in node-positive patients, the risk of relapse increased with both high SPF (P = 0.003) and estrogen receptor negativity (P = 0.004). Low SPF values distinguished grade II tumors with a particularly good outcome. Our results strongly support the use of SPF in multicenter studies and clinical trials and suggest that node-negative patients with slowly proliferating tumors do not require systemic adjuvant therapy.
Assuntos
Neoplasias da Mama/patologia , Ploidias , Fase S , Adulto , Neoplasias da Mama/genética , Neoplasias da Mama/mortalidade , DNA de Neoplasias/análise , Intervalo Livre de Doença , Feminino , Citometria de Fluxo , Humanos , Pessoa de Meia-Idade , Análise Multivariada , Estudos RetrospectivosRESUMO
Among the methodological approaches of tumor proliferation, thymidine kinase (TK) and thymidylate synthase (TS) assays take into account the specific pathways of pyrimidine synthesis. Studies pointing to a prognostic value of TK and TS in breast cancer involved small numbers of patients. We investigated the prognostic value of these enzymes and their combination in a large retrospective multicenter study. Nine hundred eight T1T2, N0N1, M0 primary breast cancer samples (median follow-up 68 months) were tested. TK and TS were measured in cytosols by using standardized radioenzymatic methods. Although a positive correlation was obtained between TK and TS (p<10(-5)), major discrepancies were observed in some tumors. High levels of both enzymes were associated with large tumor size, histological grade III and steroid receptor-negative tumors. Univariate analysis showed that TK, TS and their combination were predictive of poor metastasis-free (MFS) (p < 10(-4); p=0.004; p < 10(-4)) and disease-free survival (DFS) (p < 10(-4); p=0.007; p=0.0001). TK was selected as an independent factor for MFS in Cox analysis. It was the only variable selected in node-negative patients. Subgroups with specific outcomes, with possible therapeutic implications, were identified: a) in node-negative patients not receiving adjuvant treatment, TK values in the 4th quartile were associated with poor MFS (p=0.0002) and DFS (p=0.0005) as compared to the other quartiles; b) in node-positive patients receiving adjuvant chemotherapy, low levels of both TK and TS were associated with the highest survival rates (MFS: p=0.04; DFS: p=0. 03).
Assuntos
Neoplasias da Mama/enzimologia , Proteínas de Neoplasias/análise , Timidina Quinase/análise , Timidilato Sintase/análise , Adulto , Idoso , Análise de Variância , Neoplasias da Mama/patologia , Citosol/enzimologia , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Estudos RetrospectivosRESUMO
As part of a clinical research project co-ordinated in Grenoble, six French institutions (CRLCC Angers, CHU Grenoble, Hospices civils Lyon, AP Marseille, CRLCC St-Cloud, CHU Tours) grouped together in order to study the following proliferative parameters in primary breast cancer: DNA synthesis enzymes [thymidine kinase (TK), thymidylate synthase (TS)], signal transduction enzyme [protein tyrosine kinase (PTK)] and S-phase fraction (%S). TK, TS and PTK were measured in cytosols using radio-enzymatic biochemical methods. S-phase was estimated using flow cytometry. The first step consisted in standardization and technical validation of the measurements. The second step consisted in the clinical validation by using a retrospective series of 1,003 breast cancers T1T2, N0N1, M0. We report the results of the first step, together with the distributions of the variables and their relationship with classical clinical variables: 1) Using standardized methods and a cytosolic control, a good reproducibility of measurements was obtained, whether assays were performed in one (TS, PTK) or in several laboratories (TK). 2) Significantly different distributions of TK and TS were observed between the different centres mainly due to different conditions of storage of tumours and cytosols. 3) A highly significant correlation was observed between TK, TS and PTK. Highest TK, TS and PTK levels were observed in tumours with high histological grade or receptor negative tumors. This study clearly illustrates the importance of quality assurance of multicentre studies.
Assuntos
Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/enzimologia , Carcinoma Ductal de Mama/patologia , Proteínas de Neoplasias/análise , Proteínas Tirosina Quinases/análise , Timidina Quinase/análise , Timidilato Sintase/análise , Adulto , Idoso , Divisão Celular , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
Urokinase type plasminogen activator (uPA) and its inhibitors, plasminogen activator inhibitor type I (PAI-1) and type II (PAI-2), are supposed to be involved in the expression of the invasive and metastatic phenotype of cancer cells. However, clinical investigations on the prognostic significance of their levels in tumor tissue are difficult to realize because of the absence of a convenient method of measurement of these parameters. The aim of the present investigation was to set up a method allowing the measurement of these enzymes and of sex steroid receptor status in appropriate subcellular fraction(s) in conditions easily reproducible in routine. We found that a tissue homogenate prepared according to the method recommended [5] for current measurement of sex steroid receptors is appropriate for further distinct preparations. One aliquot is used for cytosol preparation; another can be treated by 2% Triton X-100 (vol/vol) and provide an extract containing the totality of uPA and PAI-1. The advantage of this procedure is that appropriate subcellular fractions can be derived from a unique homogenization step. Total uPA and PAI-1 are measured in a Triton extract with good performance as compared to previous investigations [4]. PAI-2 is measured in the same cytosol fraction used for sex steroid receptors and other parameters. Because of its simplicity and its high reliability, this method could be a useful tool in the investigation of uPA family proteases and analysis of their prognostic significance in early breast tumors.
Assuntos
Neoplasias da Mama/química , Mama/química , Química Clínica/métodos , Inibidor 1 de Ativador de Plasminogênio/isolamento & purificação , Inibidor 2 de Ativador de Plasminogênio/isolamento & purificação , Ativador de Plasminogênio Tipo Uroquinase/isolamento & purificação , Mama/enzimologia , Neoplasias da Mama/enzimologia , Feminino , Humanos , Frações Subcelulares/química , Frações Subcelulares/enzimologia , Extratos de Tecidos/químicaRESUMO
In a study involving 50 breast cancer tumours, we compared two oestrogen receptor (ER) detection methods developed by us--a microplate immunoenzymometric assay (EIA96) and an immunohistochemistry kit (HistoCIS-ER)--with the radioligand assay (RLA), the Abbott immunoenzymometric assay ER-EIA and the reverse transcriptase polymerase chain reaction technique (RT-PCR). Among the three ER protein cytosolic assays (EIA96, ER-EIA and RLA), the two EIAs showed the best agreement (y = 1.086x - 7.840; r2 = 0.876). At the calculated optimal cut-off values (8 and 14 fmol mg(-1) protein for EIA96 and RLA respectively), EIA96 was more sensitive than RLA (0.94 for EIA96, 0.88 for RLA), but slightly less specific (0.82 for EIA96, 0.94 for RLA). The Cox logistical regression model applied to EIA96, RLA and RT-PCR showed that EIA96 discriminated the best between ER-EIA+ and ER-EIA- samples. The RT-PCR technique and HistoCIS-ER both had a positivity-negativity concordance of 86% with EIA96.
Assuntos
Receptores de Estrogênio/análise , Adenocarcinoma/química , Neoplasias da Mama/química , Feminino , Humanos , Técnicas Imunoenzimáticas , Imuno-Histoquímica , RNA Mensageiro/análise , Receptores de Estrogênio/genéticaRESUMO
The estrogen receptor (ER) status of breast cancer is used both as a prognostic factor and as a predictor of response to endocrine therapy. An immunoenzymometric assay for ER was developed on 96-well microtiter plates (EIA96). This technique involves two monoclonal antibodies directed against different epitopes in the B domain of ER. The two-step protocol (16-18 h and 3 h at 4 degrees C) requires 100 microL of cytosol. This assay showed a detection limit of 0.58 pmol/L. Intra- and interassay CVs of clinical specimens were < or = 5% except for the least concentrated sample (6.5 pmol/L, CV = 6.7%). In a comparison study involving cytosols of breast adenocarcinoma tissue biopsies, we compared the EIA96 with the radioligand assay (RLA) and the Abbott ER-EIA, widely used techniques for determining ER concentration in cytosols of breast cancer tumors. The two EIAs showed excellent agreement; however, two samples showed discrepant results by EIA96 and RLA.
Assuntos
Adenocarcinoma/química , Neoplasias da Mama/química , Técnicas Imunoenzimáticas , Receptores de Estrogênio/análise , Biópsia , Citosol/química , Feminino , Humanos , Técnicas Imunoenzimáticas/estatística & dados numéricos , Sensibilidade e EspecificidadeRESUMO
PURPOSE: To clarify the role of the c-Ha-ras-1 gene in bladder cancer predisposition and prognosis. MATERIALS AND METHODS: The c-Ha-ras-1 locus was studied by Southern blotting in white blood cells and tumor samples obtained from 126 patients with bladder cancer (74 Ta-T1 and 52 T2-T4). A comparison with 84 unaffected patients and a survival analysis were performed. RESULTS: The patients with bladder cancer presented 7 different c-Ha-ras-1 alleles, 12 different genotypes, heterozygosity in 49% of cases and a loss of heterozygosity (in the tumor) in 13 cases. The most frequent allele (a1, 6.6 kb) was present in 83% of patients. Heterozygosity correlated with vascular invasion in the tumor (p < 0.0001). In the small subgroup of 11 patients with rare alleles and genotypes, these alleles and genotypes occurred more often in patients with T2-T4 tumors (p < 0.01 for alleles and genotypes), aneuploid tumors (p < 0.001, p < 0.005) and tumors with vascular invasion (p < 0.01, p < 0.005). However, in this study, the majority of patients with high risk tumors possessed common alleles and genotypes. Survival analysis showed that neither the c-Ha-ras-1 genotype nor allelomorphism was an independent prognostic factor. Elsewhere, no rare allele occurred more frequently in bladder cancer affected patients than in unaffected patients. CONCLUSION: This study confirms c-Ha-ras-1 gene polymorphism in a bladder cancer affected population and, in some cases, a loss of genetic material in the vicinity of this locus. No specific genotype can be implicated in the predisposition to bladder carcinoma, and c-Ha-ras-1 genotyping appears of limited value in the clinical management of these patients.
Assuntos
Genes ras/genética , Neoplasias da Bexiga Urinária/genética , Mapeamento Cromossômico , Genótipo , Heterozigoto , Homozigoto , Humanos , Taxa de Sobrevida , Neoplasias da Bexiga Urinária/mortalidadeRESUMO
The c-Ha-ras-1 polymorphism was studied in 92 bladder tumor samples (newly diagnosed and/or recurrent) obtained from 73 patients and in the paired white blood cells (WBC). A heterozygous state was detected in WBC DNA of 38 patients (52%). The statistical analysis (univariate and multivariate) demonstrated an association between the heterozygous state of the patients and a lymphatic invasion. In patients with a pTa tumor, there was a relation between the heterozygous state and a younger age at diagnosis. A loss of heterozygosity for c-Ha-ras-1 locus was detected in seven out of the 38 informative tumors (18.4%). No significant correlation was observed with the prognostic factors. These results address the relation between the heterozygous genomic state and the risk of lymphatic invasion in the patients with a bladder tumor.
Assuntos
Genes ras , Polimorfismo de Fragmento de Restrição , Neoplasias da Bexiga Urinária/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , DNA de Neoplasias/análise , Feminino , Heterozigoto , Humanos , Leucócitos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Neoplasias da Bexiga Urinária/patologiaAssuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Amplificação de Genes , Proteínas Proto-Oncogênicas/genética , Proto-Oncogenes , Feminino , Humanos , Prognóstico , Proteínas Tirosina Quinases/genética , Receptor ErbB-2 , Receptores de Estrogênio/análise , Receptores de Progesterona/análiseRESUMO
In 199 breast cancers, HER-2/neu amplification was analyzed by Southern blotting (149 cases) and by slot blotting (149 cases), with 99 cases studied using both techniques. There were 18.8% amplified tumors (> or = 2 copies) by Southern blotting and 15.4% by slot blotting. The difference in the percentages of amplified tumors was not statistically significant (p = 0.44). There was a correlation between HER-2/neu amplification and the SBR grade (p = 0.046): this correlation relied on the absence of amplification in the GI tumors. In a subset study, the negativity of the progesterone receptor content was correlated with HER-2/neu amplification in the node positive (p = 0.02), the pre-menopausal (p = 0.04) and the pre-menopausal node positive (p = 0.002) patients. In the literature as in our results, amplification appears to be correlated with poor prognostic factors. However, in a subgroup with most of the favorable prognostic factors: positive estrogen and progesterone receptor contents and node negativity, the frequency of amplified tumors (19.4%, n = 67) was the same as that observed in the whole group (16.6%, n = 199). This result may suggest that the HER-2/neu amplification could act as an independent prognostic factor.
Assuntos
Neoplasias da Mama/genética , Amplificação de Genes/genética , Proteínas Oncogênicas Virais/genética , Adulto , Idoso , Análise de Variância , Southern Blotting , Neoplasias da Mama/mortalidade , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , Receptor ErbB-2RESUMO
A non-radioactive DNA probe for the TEM-type beta-lactamase gene was obtained by using the 'Chemiprobe' system. It was used along with a 32P-labeled TEM probe to screen for TEM beta-lactamase gene in 107 bacterial isolates representing 7 Gram-negative genera and previously classified as TEM-positive or negative. The DNA to be tested was extracted from these bacterial isolates by the Birnboim-Doly method and, after blotting into charged nylon membranes, it was submitted to hybridization with either the TEM 'Chemiprobe' or the 32P-TEM probe. The TEM 'Chemiprobe' could detect as few as 25 pg specific DNA if it was used at a concentration of 5 ng per cm2 of membrane. The results obtained by both probes were concordant in 93.5% of the entire sample. The TEM 'Chemiprobe' was specific since only one false positive was observed. Furthermore, it appeared at least as sensitive as the 32P-labeled TEM probe. As the dot-hybridization with the sulfone-labeled probe was sensitive, simple and easy to perform, it will be useful for large-scale screening in clinical laboratory.