Publications by authors named "Ronaldo Cesar Borges Gryschek"

Using a panel study design, we aimed to estimate the seroconversion and seroreversion rates of anti-Strongyloides IgG antibodies from surveys carried out 11 months apart in a rural community in the Amazon Basin in Brazil. We used enzyme immunoassays to measure anti-Strongyloides IgG antibodies in 325 baseline plasma samples and 224 others that were collected 11 months later from residents in the agricultural settlement of Granada, Acre State. We observed anti-Strongyloides IgG antibodies in 21.

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Article Synopsis
  • Immunosuppressed patients, especially those who have undergone organ transplants, are at risk for severe infections from the parasite Strongyloides stercoralis.
  • This study focused on detecting anti-Strongyloides IgG antibodies in liver transplant patients using two methods: an initial screening with ELISA and confirmation with Western blotting.
  • The results showed a 10.9% reactivity rate in the ELISA test, with a significant portion of positive cases identifying a specific protein fraction, emphasizing the need for routine screening for this infection in liver transplant recipients.
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Strongyloidiasis has been a neglected parasitic infection caused by Strongyloides genus parasites. Despite assessment of S. stercoralis exposure in different vulnerable populations, seroprevalence in inmates worldwide remains to be fully established.

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Background: The potential that Strongyloides stercoralis infection has to cause major morbidity and high mortality when the disseminated form occurs in transplant patients is of particular concern.

Methods: In this study, the objective was to observe S. stercoralis infection in patients who are candidates for transplantation by using parasitological, serological, and molecular techniques and to propose an algorithm for the detection of that infection in transplant candidates.

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Strongyloides stercoralis, a pathogenic roundworm, is considered endemic in several tropical and subtropical areas worldwide. Indigenous populations have the highest soil-transmitted helminthiases-related mortality rates, but the prevalence and risk factors associated with S. stercoralis in Brazilian indigenous populations have not been established.

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Serodiagnosis of strongyloidiasis is usually performed by ELISA for the detection of IgG antibodies due to its high sensitivity and practicality, but its main limitation is a constant source of S. stercoralis antigens. The use of S.

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Serodiagnosis of human strongyloidiasis is a practical alternative to parasitological methods due to its high sensitivity. However, cross-reactivity with other helminth infections limits its utility, and this problem is due to the use of homologous or heterologous somatic extracts of the parasite as an antigen source. Excretory-secretory (E/S) products from Strongyloides infective larvae can be used to improve the serodiagnosis.

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Objective: The association between diabetes and Strongyloides infection remains controversial. This study aimed to detect Strongyloides stercoralis DNA in the feces of patients with Diabetes Mellitus type 2 (DM2).

Methods: Fecal samples were analyzed via the Lutz, Rugai, and agar plate culture methods.

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This study aimed to report the first case of a patient with hepatosplenic schistosomiasis mansoni, refractory ascites and portal vein thrombosis treated with a transjugular intrahepatic portosystemic shunt (TIPS), at the Instituto de Radiologia, Hospital das Clinicas, Faculdade de Medicina, Universidade de Sao Paulo, Brazil. After the procedure, the patient recovered favorably and progressed with portal pressure reduction and no deterioration of the liver function. Endovascular shunt modification is a conservative medical approach that often helps in reducing symptoms significantly, making it a less invasive and a safer alternative to liver transplantation for the treatment of schistosomiasis with portal hypertension.

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The Western-blotting technique was applied to identify antigenic fractions of excretory-secretory Toxocara canis antigen recognized by IgG antibodies throughout an experimental infection in mice challenged by different inocula. Mice were inoculated with 5, 50 and 500 embryonated eggs and serum samples were collected 15, 30, 60, 90 and 120 days post-infection. Serum samples were analyzed using an excretory-secretory Toxocara antigen.

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To evaluate the diagnostic accuracy of three types of antigenic preparations from Strongyloides venezuelensis infective larvae for detection of serum IgG anti-Strongyloides antibodies by enzyme-linked immunosorbent assay (ELISA). Soluble somatic fractions (SSF) and membrane somatic fractions (MSF) and excretory−secretory (E/S) products from S. venezuelensis infective larvae were evaluated against 71 sera from individuals with strongyloidiasis, 105 sera from healthy individuals, and 84 sera from individuals with other helminth infections.

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Toxocariasis is still a neglected parasitic disease worldwide and much about its biology and diagnosis has yet to be understood. The migration of third stage larvae via bloodstream suggests a potential use of molecular tools in diagnosis as well to deepen the knowledge about its migration behaviors. Conventional PCR was applied in serum and tissue samples from BALB/c mice infected with 5 and 500 embryonated eggs.

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Background: The current literature is scarce as to the outcomes of COVID-19 infection in non-Hodgkin's lymphoma patients and whether immunosuppressive or chemotherapeutic agents can cause worsening of the patients' condition during COVID-19 infection.

Case Presentation: Our case is a 59-year-old gentleman who presented to the Emergency Department of the Cancer Institute of Hospital das Clínicas da Universidade de São Paulo, São Paulo, Brazil on 10th May 2020 with a worsening dyspnea and chest pain which had started 3 days prior to presentation to the Emergency Department. He had a past history of non-Hodgkin's lymphoma for which he was receiving chemotherapy.

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This review considers the advantages and disadvantages of parasitological techniques, methods of detecting antibodies and antigens, as well as molecular biology techniques in the diagnosis of human strongyloidiasis. In addition, it elucidates the potential of different techniques for rapid and effective detection of clinical cases, thus enabling early treatment and preventing fatal consequences of this helminthiasis.

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The present study aimed to evaluate the occurrence of Blastocystis sp. in Brazilian studies over a period of years (2000-2020), as well as point out relevant aspects of this enigmatic organism. We performed a literature search using six sources of international databases.

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Blastocystis sp. is an enteric protist commonly found in human fecal samples. In Brazil, few studies have been developed, but none of them has explored the presence of Blastocystis in patients with diabetes mellitus.

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Blastocystis sp. is a protist commonly found in stool samples of humans and animals. Biological and genetic factors of this organism remain controversial.

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Approximately 240 million people worldwide are infected by Schistosoma. In Brazil, one of the main intermediate hosts of this parasite is Biomphalaria glabrata snails. The early detection of larval stages in intermediate hosts is an important challenge to public health, but it also represents an opportunity as a new alternative to indicate earlier natural infections before cercariae differentiation and emergence.

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Article Synopsis
  • The study investigates the relationship between a certain enteric protist and urticaria in patients from São Paulo, Brazil, focusing on its occurrence and molecular diversity.
  • Researchers analyzed fecal samples from 58 patients with urticaria using parasitological methods and PCR testing to identify specific subtypes of the protist.
  • The findings revealed several subtypes, with ST1, ST3, and ST4 being the most common among the patients, contributing to a better understanding of this organism's role in allergic skin conditions.
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This study aimed to evaluate the use of saliva samples in the Dot-ELISA test for immunodiagnosis of human strongyloidiasis. The Dot-ELISA presented similar results to the ELISA test, with 70% and 60% sensitivity and 85% and 90% specificity, respectively, for IgA in the saliva. The Dot-ELISA with alternative saliva samples may be a suitable tool for diagnosing human strongyloidiasis, especially in populations with high levels of exposure to helminth.

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Objective: Schistosomiasis remains a public health problem. This was a descriptive and retrospective study of 42 patients with a severe form of schistosomiasis who were admitted to the outpatient clinic of the Faculdade de Medicina da Universidade de São Paulo, São Paulo, in São Paulo, Brazil.

Methods: A data collection questionnaire was designed from the patient charts, and the following variables were evaluated: age, sex, place of birth, occupation, signs and symptoms of schistosomiasis, data from laboratory and imaging examinations, data regarding treatment outcomes, and the existence of comorbidities.

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