Identification of periodontal pathogens in healthy periimplant sites.

PURPOSE: : The aim of this study was to evaluate the presence of periodontopathogens in subgingival periimplant sites in partially edentulous patients using polymerase chain reaction procedures, with regard to areas with clinical and radiographic signs of health and areas presenting periimplant disease. MATERIALS AND METHODS: : Thirty nonsmoking, partially edentulous patients, aged 30 to 76 years, were included in this study and divided in 3 groups according their clinical and radiographic characteristics. Group A (n = 10) presented periimplant health, group B (n = 10) presented periimplant mucositis, and group C (n = 10) were patients with periimplantitis. Periimplant tissues were clinically examined as regards the color of mucosae, presence of bacterial plaque, depth and bleeding on probing, and local suppuration. History of periodontal disease was also considered. Radiographic analysis evaluated the presence of bone loss around the implant. Samples of periimplant crevicular fluid were collected to analyze the presence of periodontal pathogens, Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsythensis (Tf), and Treponema denticola (Td). RESULTS: : The results showed that the history of periodontal disease is associated with periimplant disease. The bacteria Aa, Pg, Pi, Td, and Tf were present in periimplant sites clinically and radiographically characterized, as healthy periimplant tissues, mucositis, and periimplantitis. CONCLUSIONS: : We concluded that Aa, Pg, Pi, Td, and Tf are present in healthy and diseased conditions. Therefore, these periodontal pathogens are not strictly related to periimplant disease sites.

Diagnóstico do gene quimérico BCR-ABL e doença residual mínima em diferentes malignidades hematológicas

Estudos citogenéticos e moleculares em pacientes com leucemias são usados para a identificação de alterações gênicas com valor diagnóstico e prognóstico. Estes estudos, aqui apresentados, têm sido úteis para a caracterização e o monitoramento das leucemias associadas à presença de transcritos BCR-ABL, possibilitando a avaliação da doença residual mínima e a previsão da recaída.A análise molecular qualitativa e/ou quantitativa do gene quimérico BCR-ABL foi realizada em 80 pacientes através da Reação em Cadeia da Polimerase utilizando o ADN complementar ao ARN mensageiro após transcrição reversa (RT -PCR). A análise molecular por RT-PCR qualitativo foi usada para determinar diferentes pontos de quebras do gene quimérico (b3a2, b2a2, e1a2 e b2a3), permitindo a caracterização molecular de diferentes desordens hematológicas e monitoramento de diferentes procedimentos terapêuticos. Achados relacionados à expressão de BCR-ABL mostraram a utilidade de uma abordagem molecular rotineira para classificação de desordens mieloproliferativas e leucemias linfóides agudas Ph+ assim como no monitoramento dos tratamentos. A utilização do RT -PCR quantitativo, para estimar os níveis de BCR-ABLl/ABL em pacientes com LMC com diferentes tratamentos (Transplante de medula óssea (TMO), Infusão de linfócitos de doador (ILD) e Interferon (IFN) e em pacientes em remissão mostrou resultados consistentes. Este protocolo possibilitou um monitoramento preciso da doença residual mínima e de sua evolução, apresentando claras vantagens em relação às técnicas convencionais. O estudo preferencial por seqüenciamento de um paciente com LMC que apresentou um transcrito atípico ao diagnóstico possibilitou a caracterização do rearranjo b2a3 associado à um curso clínico agressivo. Finalmente, a análise citogenética e FISH realizados em 30 pacientes com suspeita de LMC ou após procedimentos terapêuticos para LMC permitiram o diagnóstico e a avaliação das terapias

Cytogenetic and molecular studies of leukaemic patients are useful for identifying gene rearrangements of diagnostic and prognostic significance associated to malignant transformation whose early detection has shown to be beneficial. The studies herein reported have been useful for characterising and monitoring leukaemias associated to presence of BCR-ABL transcripts as well as for assessing minimal residual disease and anticipating impending relapse. Qualitative and/or quantitative molecular analyses of the chimaeric BCRABL gene were carried out in 80 patients with Polymerase Chain Reaction assays amplifying complementary DNA following reverse transcription of messenger RNA (RT-PCR). Qualitative RT-PCR was used for identifying different breakpoints within the chimaeric BCR-ABL gene (b3a2, b2a2, e1a2, and b2a3), allowing for a molecular characterisation of different haematological disorders and monitoring different therapeutic procedures. Our findings indicated that detection of BCR-ABL transcripts should be routinely used for diagnosing myeloproliferative disorders and acute, Ph+ leukaemias as well as in serial studies following or during treatment. Quantitative RT-PCR assays, used for estimating BCR-ABL/ABL transcript levels in CML patients following or during treatment (Bone marrow transplantation, donor Iymphocyte infusion or interferon) and in remission, showed consistent results. These assays were useful for an accurate monitoring of minimal residual disease and its clinical progression, clearly preferable to conventional techniques. DNA sequence analysis of a CML patient who showed an atypical BCRABL transcript at diagnosis allowed for the characterisation of a b2a3 rearrangement associated to an aggressive clinical course. Finally, cytogenetic and FISH analyses of 30 patients with presumed CML or after CML therapy was useful for diagnosis and evaluation of therapeutic procedures