LUCIANA REGINA MEIRELES JAGUARIBE EKMAN

(Fonte: Lattes)
Índice h a partir de 2011
8
Lattes
ResearcherID
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Patologia, Faculdade de Medicina
LIM/49 - Laboratório de Protozoologia, Hospital das Clínicas, Faculdade de Medicina

Filtros

Limpar filtros

Configurações

Resultados de Busca

Agora exibindo 1 - 10 de 22
  • article 0 Citação(ões) na Scopus
    Understanding hypergammaglobulinemia in experimental or natural visceral leishmaniasis
    (2024) CARVALHO, Camila Aparecida de; HIRAMOTO, Roberto Mitsuyoshi; MEIRELES, Luciana Regina; ANDRADE, Heitor Franco de
    Nonspecific hypergammaglobulinemia (HGG) occurs in symptomatic human visceral leishmaniasis (VL) caused by L. L. infantum. This study assessed this finding in experimental infection in hamsters and natural infection in dogs. The serum concentration of proteins, albumin and globulins was determined through the biuret and bromocresol green reaction, where the HGG was better expressed through the albumin/globulin (A/G) ratio. HGG was associated with a higher concentration of specific anti-glycan antibodies (BSA-G)/promastigote soluble extract (PSE) and the presence of circulating immune complexes (IC) by dissociative enzyme-linked immunoassay (ELISA). The study found monovalent IC in 37.9% (PSE) and 50% (BSA-G) of sera from infected hamsters, with increased frequency as the disease progressed. HGG was found in >60% of the samples in dogs with VL, associated with higher levels of specific immunoglobulin (Ig)A and IgM, but not IgG, determined using the PSE and BSA-G ELISA. HGG was associated with the presence of monovalent IC in 58.9% (PSE) and 63.4% (BSA-G) positive dog samples. HGG may result not only from the nonspecific activation of B cells, with greater production of specific and nonspecific antibodies, but also due to lower IgG excretion due to the presence of soluble monovalent IC. HGG correlates to the progression of VL and may be a marker for manifested disease.
  • article 5 Citação(ões) na Scopus
    Diagnosis of Clinical Complete Response by Probe-Based Confocal Laser Endomicroscopy (pCLE) After Chemoradiation for Advanced Rectal Cancer
    (2021) SAFATLE-RIBEIRO, Adriana Vaz; MARQUES, Carlos Frederico Sparapan; PIRES, Clelma; ARRAES, Livia; BABA, Elisa Ryoka; MEIRELLES, Luciana; KAWAGUTI, Fabio Shigehissa; MARTINS, Bruno da Costa; LENZ, Luciano Tolentino; LIMA, Marcelo Simas de; GUSMON-OLIVEIRA, Carla Cristina; RIBEIRO JR., Ulysses; MALUF-FILHO, Fauze; NAHAS, Sergio Carlos
    Background Neoadjuvant chemoradiotherapy (nCRxt) followed by radical surgery is the optimal treatment for advanced rectal adenocarcinoma. Patients with clinical complete response (cCR) may be followed closely without immediate surgery. Probe-based confocal laser endomicroscopy (pCLE) is a real-time in vivo method that allows acquisition of optical biopsies with 1000 times magnification, evaluating both epithelial and vascular patterns. Aim To evaluate the role of pCLE in the diagnosis of cCR after nCRxt for advanced rectal adenocarcinoma. Methods pCLE was performed in 47 patients with locally advanced rectal adenocarcinoma (T3/T4, or N+) who underwent nCRxt (5-fluorouracil, 5040 cGy). Results Twenty-seven (57.5%) patients were men, and the mean age was 62.8 years. Thirty-seven had partial response confirmed by pCLE. Ten (21.3%) patients had good endoscopic response and presented small ulcer (n = 5) or residual scar (n = 5). After nCRxt, the essential features to differentiate malignancy from post-radiation alterations at pCLE were the presence of irregular crypts, budding, back-to-back glands, cribriform pattern, increased vessel/crypt ratio, and fluorescein leakage. A scoring system was created considering these epithelial and vascular features, with high accuracy for differentiating patients with complete response from those with residual neoplasia (p < 0.00001). pCLE sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 100%, 71.4%, 95.2%, 100%, and 95.7%, respectively. Conclusions (1) pCLE evaluation of epithelial and vascular features may improve the diagnosis of cCR and may alter patient management; (2) pCLE might be valuable for identifying patients with advanced rectal cancer who will benefit from watch and wait strategy, avoiding immediate surgical treatment.
  • article 5 Citação(ões) na Scopus
    Early high avidity specific IgG production in experimental hamster visceral leishmaniasis
    (2020) CARVALHO, Camila Aparecida de; FERRAO, Thiago Fidelis; CAVALCANTE, Fernanda Siqueira; FREITAS, Flavia Regina Novais de; MEIRELES, Luciana Regina; ANDRADE JUNIOR, Heitor Franco de
    Visceral leishmaniasis (VL) byLeishmania (Leishmania) infantumis epidemic in Brazil. Hypergammaglobulinemia appears early in patients with VL and is ineffective. Usually, high-affinity IgG B cells are selected during most infections, a critical step for an effective humoral response. The avidity of IgG antibodies in VL is unexplored due to the absence of temporal parameters in most patients, associated to low clinical significance. Experimental infection models overcome this fact, allowing the monitoring of the disease temporal evolution. In this study, the avidity of IgG antibodies was evaluated in experimental models, in infection in hamsters, and in immunization in rabbits. Specific IgG antibodies were detected by ELISA, using chaotropic solution to determine avidity, as reported for viral infections. The levels of IgG antibodies correlated with the progression of experimental infection in hamsters or antigenic stimulation in immunized rabbits. However, IgG avidity was high early in infected animals, even in early periods (> 80%), while in immunized rabbits, they had early antibodies of low avidity with progressive maturation, similar as other infections. These data suggest that the affinity maturation of the avidity of anti-LeishmaniaIgG antibodies promoted at an early stage, influencing the appropriate interaction between antigens and affecting the disease progression. This fact could be associated to monovalent immune complexes, as reported in human and experimental VL. This scenario may be related to an independent process of immune cell activation by the parasite but absent in antigen preparation used as immunogens.
  • article 10 Citação(ões) na Scopus
    CD19 LYMPHOCYTE PROLIFERATION INDUCED BY Bifidobacterium animalis subsp lactis IN C57BL/6 MICE EXPERIMENTALLY INFECTED WITH Toxoplasma gondii
    (2016) RIBEIRO, Claudia de Mello; ZORGI, Nahiara Esteves; MEIRELES, Luciana Regina; GARCIA, Joao Luis; ANDRADE JUNIOR, Heitor Franco de
    Toxoplasmosis is frequently acquired through the oral route by the ingestion of cysts or oocysts of Toxoplasma gondii. Once ingested, the parasites penetrate the intestinal epithelial cells and rapidly disseminate to all organs in the host. During T. gondii infection, the intestinal microbiota plays an important role in stimulating a protective immune response against the parasite. In this sense the use of probiotics is worthy of note since they are live microorganisms that have beneficial effects on the host through stimulation of the immune response that can be important in the control of T. gondii proliferation and dissemination in the host. In the present study, the action of the probiotic Bifidobacterium animalis subsp. lactis was investigated in C57BL/6 mice infected with oocysts of ME49 strain of T. gondii. The probiotic had an immunomodulatory action, inducing CD19 lymphocyte proliferation and consequently increasing anti-T. gondii antibody level. Bifidobacterium animalis subsp. lactis provided protection in supplemented mice, compared to the control group. In addition, supplemented animals had milder inflammatory process in the small intestine, indicating that the probiotic protects the intestinal mucosa during infection with T. gondii. It was concluded that the probiotic B. animalis subsp. lactis induces humoral immune response capable of providing protection against T. gondii infection.
  • article 1 Citação(ões) na Scopus
    Effect of chaotropes in Chagas disease and leishmaniasis cross-reacting serology assays for epidemiological surveys
    (2018) SANTOS, Anderson Pacheco dos; CARVALHO, Maria Esther de; MEIRELLES, Luciana Regina; ANDRADE JUNIOR, Heitor Franco de
    Introduction: Serological cross-reactivity between leishmaniasis and Chagas disease, especially at low titers, leads to difficulties of the seroepidemiological interpretation. Methods: We have studied the ability of urea as a chaotrope to select high-avidity antibodies in IgG ELISA, thus reducing low-avidity IgG cross-reactivity in serologically positive samples in both assays. Results: Using 0.5M urea for diluting the sample efficiently defined leishmaniasis or double infections in high-avidity IgG ELISA and eliminated false-positive results. Conclusions: The use of a chaotropic diluting agent is useful for improving the specificity of Chagas disease and leishmaniasis immunoassays.
  • article 3 Citação(ões) na Scopus
    Natural versus Recombinant Viral Antigens in SARS-CoV-2 Serology: Challenges in Optimizing Laboratory Diagnosis of COVID-19
    (2020) MEIRELES, Luciana Regina; SILVA, Angelica Moura Freixeira da; CARVALHO, Camila Aparecida; KESPER, Norival; GALISTEO JR., Andres Jimenez; SOARES, Camila Pereira; ARAUJO, Danielle Bastos; DURIGON, Edison Luiz; OLIVEIRA, Danielle Bruna Leal; MORGANTI, Ligia; CHURA-CHAMBI, Rosa Maria; ANDRADE JR., Heitor Franco de
    OBJECTIVES: COVID-19 is a public health emergency of international concern whose detection in recovered asymptomatic patients is dependent on accurate diagnosis as it enables the estimation of the susceptibility of the population to the infection. This demand has resulted in the development of several commercial assays employing recombinant proteins, but the results of these assays are not reliable as they do not involve comparison with natural viral antigens. We independently used the SARS-CoV-2 whole viral antigen (WVA) and recombinant nucleocapsid protein (rNP) to develop in-house ELISAs for IgG detection; the results of these ELISAs were then compared to obtain reliable results. METHODS: WVA and rNP ELISAs were performed on COVID-19 negative sera from patients before the pandemic in Brazil, and on RT-qPCR-positive or SARS-CoV-2-IgG against rNP and IgG against WVA-positive samples from recently infected patients in Sao Paulo, Brazil. RESULTS: Both ELISAs detected a large fraction of infected patients but exhibited certain drawbacks. Higher signals and lower numbers of false-negatives were observed in rNP ELISA; however, a higher fraction of false-ositives was observed in control groups. A high number of false-negatives was observed with WVA ELISA. Correlating the results of rNP and WVA ELISAs resulted in improved performance for COVID-19 diagnosis. CONCLUSION: The choice of antigen is an important aspect in optimizing the laboratory diagnosis of COVID-19. The use of rNP ELISA for the detection of anti-SARS-CoV-2 IgG antibodies seems promising, but comparison of the results with those of WVA ELISA is crucial for accurate test development prior to commercialization. IgG serology using several assays, and with the spectral patterns of SARS-CoV-2, resulted in confusing information that must be clarified before the establishment of diagnostic serology criteria.
  • article 3 Citação(ões) na Scopus
    Isolated specific IgA against respiratory viruses, Influenza or SARS-CoV-2, present in the saliva of a fraction of healthy and asymptomatic volunteers
    (2022) ZORGI, Nahiara Esteves; MEIRELES, Luciana R.; OLIVEIRA, Danielle Bruna Leal; ARAUJO, Danielle Bastos; DURIGON, Edson L.; ANDRADE JUNIOR, Heitor Franco de
    Objectives: Defense against respiratory viruses depends on an immune response present in the mucosa, as saliva IgA secretes antibodies. During the pandemic, such as influenza or SARS-CoV-2, most infected patients are asymp-tomatic but retain specific antibodies post-infection. The authors evaluated IgG and IgA antibodies against SARS-CoV-2 and influenza in the saliva of asymptomatic volunteers, validated with controls or vaccinated individuals.Methods: The authors detected specific antibodies by validated conventional ELISA using natural SARS-CoV-2 antigens from infected Vero cells or capture-ELISA for influenza using natural antigens of the influenza vaccine.Results: Saliva from influenza-vaccinated individuals had more IgA than paired serum, contrary to the findings for specific IgG. In COVID-19-vaccinated samples, specific IgA in saliva increased after vaccination, but IgG levels were high after the first dose. In saliva from the asymptomatic population (226), anti-Influenza IgG was found in 57.5% (130) of samples, higher than IgA, found in 35% (79) of samples. IgA results were similar for SARS-CoV-2, with IgA present in 30% (68) of samples, while IgG was less present, in 44.2% (100) of samples. The proportion of influenza IgG responders was higher than that for SARS-CoV-2 IgG, but both populations presented similar pro-portions of IgA responders, possibly due to variable memory B cell survival. For both viruses, the authors found an important proportion (> 10%) of IgA+IgG-samples, suggesting the occurrence of humoral immunity directed to the mucosa.Conclusion: Specific antibodies for respiratory viruses in saliva are found in either infection or vaccination and are a convenient and sensitive diagnostic tool for host immune response.
  • article 3 Citação(ões) na Scopus
    Saliva collection and detection of anti-T. gondii antibodies of low-income school-age children as a learning strategy on hygiene, prevention and transmission of toxoplasmosis
    (2019) MACRE, Miriam de Souza; MEIRELES, Luciana Regina; SAMPAIO, Barbara Fialho Carvalho; ANDRADE JUNIOR, Heitor Franco de
    School-age children are a social group in which blood collection for laboratory testing can be perceived as an invasive procedure, with low acceptance and tolerance of stakeholders. This problem could be circumvented by replacing serum samples with saliva. For this purpose, and to make the collection of saliva samples playful and instructive for children, educational activities on hygiene and toxoplasmosis transmission and prevention were performed using toys and audiovisual tools. The target audience consisted of 7-10 year-old children from low-income families who attended public schools in the city of Sao Paulo. Saliva samples were used in a previously described in-house Enzyme-Linked Immunosorbent Assays (ELISA) to detect anti-Toxoplasma gondii IgG antibodies and establish the immunological status of each of the participants. One year later, children's memory and fixation of concepts regarding hygiene habits, as well as transmission and prevention of toxoplasmosis were tested in the same schools, by means of a questionnaire application, using students who did not participate in the first intervention as controls. The prevalence of positive anti-T. gondii IgG among students was 50% (82/164). One year later, 45 children had more knowledge on toxoplasmosis (28/45 vs 29/147) and they drew the cat's involvement in the transmission of toxoplasmosis more often than controls (28/45 vs 29/147). Sorted according to the presence of specific IgG in saliva, recovered positive students presented worse memory of the above cited knowledge as did saliva-negative IgG students, but both groups had isolated higher frequency of fixed knowledge than non-intervened students. Our data show that there is a high prevalence of T. gondii infection in school-children from low-income areas; saliva is an alternative to blood for anti-T. gondii IgG detection; and a one-day educational intervention in school-children was effective in promoting knowledge fixation on hygiene and toxoplasmosis transmission and prevention after one year.
  • article 6 Citação(ões) na Scopus
    Measles, rubella, mumps and Toxoplasma gondii antibodies in saliva of vaccinated students of schools and universities in Sao Paulo City, Brazil
    (2020) SAMPAIO, Barbara Carvalho Fialho; RODRIGUES, Jaqueline Polizeli; MEIRELES, Luciana Regina; ANDRADE JUNIOR, Heitor Franco de
    Introduction: Vaccines are well-established public health interventions with major impact on the prevalence of infectious diseases, but outbreaks are occurring frequently due to primary and secondary failures, despite high coverage. Surveillance of efficacy and duration of induced immunity is a difficult task as it requires invasive blood sampling in children and teenagers. Saliva can be an acceptable alternative source of IgG to assess vaccine efficacy and toxoplasmosis incidence. We investigated IgG response for measles, mumps, rubella, and T. gondii in saliva samples of vaccinated young people. Methods: Saliva was collected from 249 public schools students from Sao Paulo, Brazil, aged 7 to 13 years old, during an interactive exhibition on hygiene. We used S. aureus protein A solid phase capture assay for IgG reactive to biotinylated purified proteins. Paired saliva and serum (47) were tested from young adults with serum evidence of T. gondii infection and from negative children less than 12 month old for standardization. Reproducibility was greater than 98% and sensitivity and specificity of the saliva assays were greater than 95%, as well as the concordance of paired saliva and serum samples. Results: Saliva from high school students showed a prevalence of 8.5% (95% CI: 5.0-11.9%) for anti T. gondii IgG; 96.8% (94.6-99%) of anti-measles IgG; 59.1% (53-65%) of anti-rubella IgG, and 57.5% (51.3-63.6%) of anti-mumps IgG. Discussion: The prevalence of antibodies against mumps and rubella after 6-8 years of vaccination was lower than against measles among students. The findings of this study demonstrate the feasibility of saliva sampling for follow-up of vaccine immune status in teenagers. This useful approach allows for IgG detection for vaccine control or epidemiological studies. (C) 2019 Sociedade Brasileira de Infectologia.
  • article 36 Citação(ões) na Scopus
    HUMAN TOXOPLASMOSIS OUTBREAKS AND THE AGENT INFECTING FORM. FINDINGS FROM A SYSTEMATIC REVIEW
    (2015) MEIRELES, Luciana Regina; EKMAN, Claudio Cesar Jaguaribe; ANDRADE JR., Heitor Franco de; ALBUQUERQUE, Expedito Jose de
    Toxoplasmosis, a worldwide highly prevalent zoonotic infection, is transmitted either by the oocysts, from water and soil, or the tissue cysts, in raw or undercooked infected meat, of Toxoplasma gondii. An ongoing debate is whether there are differences between the clinical and epidemiological characteristics of the outbreaks due to one or the other infective form of the agent. We performed a systematic review, recovering 437 reported outbreaks of which 38 were selected. They were complete reports containing ascribed Toxoplasma infecting form, and clinical and demographic data. There was no gender or age group selection in the outbreaks, which were described more often in the Americas. A large number of individuals were affected when oocysts, associated with soil and water contaminated with cat feces, were considered the transmission source. Onset of symptoms occurred early when the infection was ascribed to meat tissue cysts (11.4 +/- 6.7 days) with sharpened temporal distribution of cases, while a broader and prolonged appearance of new cases was observed when oocysts in water were the source of the infection (20 +/- 7 days, p < 0.001). Such information may be useful in the design and implementation of control strategies.