LIDIA YAMAMOTO

(Fonte: Lattes)
Índice h a partir de 2011
7
Projetos de Pesquisa
Unidades Organizacionais
LIM/48 - Laboratório de Imunologia, Hospital das Clínicas, Faculdade de Medicina

Resultados de Busca

Agora exibindo 1 - 3 de 3
  • article 38 Citação(ões) na Scopus
    The performance of four molecular methods for the laboratory diagnosis of congenital toxoplasmosis in amniotic fluid samples
    (2013) TEIXEIRA, Leandro Emidio; KANUNFRE, Kelly Aparecida; SHIMOKAWA, Paulo Tadashi; TARGA, Lilia Spaleta; RODRIGUES, Jonatas Cristian; DOMINGUES, Wilson; YAMAMOTO, Lidia; OKAY, Thelma Suely
    Introduction: Toxoplasmosis may be life-threatening in fetuses and in immune-deficient patients. Conventional laboratory diagnosis of toxoplasmosis is based on the presence of IgM and IgG anti-Toxoplasma gondii antibodies; however, molecular techniques have emerged as alternative tools due to their increased sensitivity. The aim of this study was to compare the performance of 4 PCR-based methods for the laboratory diagnosis of toxoplasmosis. One hundred pregnant women who seroconverted during pregnancy were included in the study. The definition of cases was based on a 12-month follow-up of the infants. Methods: Amniotic fluid samples were submitted to DNA extraction and amplification by the following 4 Toxoplasma techniques performed with parasite B1 gene primers: conventional PCR, nested-PCR, multiplex-nested-PCR, and real-time PCR. Seven parameters were analyzed, sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and efficiency (Ef). Results: Fifty-nine of the 100 infants had toxoplasmosis; 42 (71.2%) had IgM antibodies at birth but were asymptomatic, and the remaining 17 cases had non-detectable IgM antibodies but high IgG antibody titers that were associated with retinochoroiditis in 8 (13.5%) cases, abnormal cranial ultrasound in 5 (8.5%) cases, and signs/symptoms suggestive of infection in 4 (6.8%) cases. The conventional PCR assay detected 50 cases (9 false-negatives), nested-PCR detected 58 cases (1 false-negative and 4 false-positives), multiplex-nested-PCR detected 57 cases (2 false-negatives), and real-time-PCR detected 58 cases (1 false-negative). Conclusions: The real-time PCR assay was the best-performing technique based on the parameters of Se (98.3%), Sp (100%), PPV (100%), NPV (97.6%), PLR (co), NLR (0.017), and Ef (99%).
  • article 7 Citação(ões) na Scopus
    Factors associated with hyperglycemia and low insulin levels in children undergoing cardiac surgery with cardiopulmonary bypass who received a single high dose of methylprednisolone
    (2013) ARKADER, Ronaldo; MALBOUISSON, Luiz Marcelo; NEGRO, Gilda Maria Barbaro Del; YAMAMOTO, Lidia; OKAY, Thelma Suely
    OBJECTIVES: Administering steroids before cardiopulmonary bypass in pediatric heart surgery modulates systemic inflammatory response syndrome and improves postoperative recovery. However, the use of steroids aggravates hyperglycemia, which is associated with a poor prognosis. Adult patients with systemic inflammatory response syndrome usually evolve with hyperglycemia and high insulin levels, whereas >90% of pediatric patients exhibit hyperglycemia and low insulin levels. This study aims to determine: A) the metabolic and inflammatory factors that are associated with hyperglycemia and low insulin levels in children who underwent cardiac surgery with cardiopulmonary bypass and who received a single high dose of methylprednisolone and B) the best predictors of insulin variation using a mathematical model. METHODS: This preliminary study recruited 20 children who underwent heart surgery with cardiopulmonary bypass and received methylprednisolone (30 mg/kg) immediately after anesthesia. Among the 20 patients initially recruited, one was excluded because of the absence of hyperglycemia and lower insulin levels after surgery. However, these abnormalities were confirmed in the remaining 19 children. The C-peptide, CRP, IL-6, and adrenomedullin levels were measured before surgery, immediately after cardiopulmonary bypass, and on the first, second, and third days after cardiac surgery. RESULTS: IL-6, CRP, and adrenomedullin increments were observed, whereas the C-peptide levels remained within reference intervals. CONCLUSION: The multiple regression model demonstrated that in addition to age and glycemia (two well-known factors that are directly involved in glucose metabolism), adrenomedullin and IL-6 levels were independent factors associated with lower insulin concentrations. These four parameters were responsible for 64.7% of the observed insulin variances. In addition, the fact that C-peptide levels did not fall together with insulin could have grounded the medical decision not to administer insulin to patients.
  • article 9 Citação(ões) na Scopus
    DETECTION OF Bartonella henselae DNA IN CLINICAL SAMPLES INCLUDING PERIPHERAL BLOOD OF IMMUNE COMPETENT AND IMMUNE COMPROMISED PATIENTS BY THREE NESTED AMPLIFICATIONS
    (2013) KAWASATO, Karina Hatamoto; OLIVEIRA, Lea Campos de; VELHO, Paulo Eduardo Neves Ferreira; YAMAMOTO, Lidia; NEGRO, Gilda Maria Barbaro Del; OKAY, Thelma Suely
    Bacteria of the genus Bartonella are emerging pathogens detected in lymph node biopsies and aspirates probably caused by increased concentration of bacteria. Twenty-three samples of 18 patients with clinical, laboratory and/or epidemiological data suggesting bartonellosis were subjected to three nested amplifications targeting a fragment of the 60-kDa heat shock protein (HSP), the internal transcribed spacer 16S-23S rRNA (ITS) and the cell division (FtsZ) of Bartonella henselae, in order to improve detection in clinical samples. In the first amplification 01, 04 and 05 samples, were positive by HSP (4.3%), FtsZ (17.4%) and ITS (21.7%), respectively. After the second round six positive samples were identified by nested-HSP (26%), eight by nested-ITS (34.8%) and 18 by nested-FtsZ (78.2%), corresponding to 10 peripheral blood samples, five lymph node biopsies, two skin biopsies and one lymph node aspirate. The nested-FtsZ was more sensitive than nested-HSP and nested-ITS (p < 0.0001), enabling the detection of Bartonella henselae DNA in 15 of 18 patients (83.3%). In this study, three nested-PCR that should be specific for Bartonella henselae amplification were developed, but only the nested-FtsZ did not amplify DNA from Bartonella quintana. We conclude that nested amplifications increased detection of B. henselae DNA, and that the nested-FtsZ was the most sensitive and the only specific to B. henselae in different biological samples. As all samples detected by nested-HSP and nested-ITS, were also by nested-FtsZ, we infer that in our series infections were caused by Bartonella henselae. The high number of positive blood samples draws attention to the use of this biological material in the investigation of bartonellosis, regardless of the immune status of patients. This fact is important in the case of critically ill patients and young children to avoid more invasive procedures such as lymph nodes biopsies and aspirates.