A randomized double-blind placebo-controlled trial to evaluate the immunogenicity of a candidate vaccine against American tegumentary leishmaniasis.

This study was aimed at evaluating the immunogenicity of a vaccine composed of killed Leishmania amazonensis promastigotes using several different protocols in a randomized, double-blind and controlled trial design in order to select one of them for further efficacy trials. One hundred and fourteen leishmanin skin test (LST)-negative healthy volunteers were allocated into eight groups that received either two or three deep intramuscular injections of vaccine at doses of 180, 360 and 540 microg or similar injections of placebo. Cell-mediated immune responses were evaluated before and after vaccination by means of LST as well as proliferative responses and cytokine production in Leishmania antigen-stimulated peripheral blood mononuclear cell cultures.

TcRho1, a farnesylated Rho family homologue from Trypanosoma cruzi: cloning, trans-splicing, and prenylation studies.

Rho GTPases are members of the Ras superfamily and are involved in signal transduction pathways, including maintenance of cell morphology and motility, cell cycle progression, and transcription activation. We report the molecular identification in trypanosomatids (Trypanosoma cruzi) of the first member of the Rho family. The cloned Rho protein, TcRho1, shares approximately 40% homology with other members of the Rho family.

In vitro study of the effect of aged eugenol on the flow, setting time and adhesion of Grossman root canal sealer.

In the present study, the effect of aged eugenol (up to 180 days) on the flow, setting time and adhesion of Grossman root canal sealer was evaluated, following the American Dental Association specification number 57 for root canal sealers. An Instron Universal testing machine 4444 was used for testing adhesion. There were statistically significant differences between groups, with a higher flow, lower setting time and adhesion for aged eugenol.

Geodesics without conjugate points and curvatures at infinity.

We study the asymptotic behavior of curvature and prove that the integral of curvature along a geodesic without conjugate points is nonpositive and some generalizations of Myers theorem and Cohn-Vossen's theorem. Some applications are also given.

Prevalence of Helicobacter pylori resistance to metronidazole, clarithromycin, amoxicillin, tetracycline, and furazolidone in Brazil.

Background: Helicobacter pylori infection is associated with a wide range of digestive diseases and is very prevalent in developing countries, although few data exist on the susceptibility of H. pylori to antimicrobials commonly used in eradication schedules in these countries. The aim of this study was to evaluate the resistance of H.

Atypical mucocutaneous leishmaniasis caused by Leishmania braziliensis in an acquired immunodeficiency syndrome patient: T-cell responses and remission of lesions associated with antigen immunotherapy.

An atypical case of acquired immunodeficiency syndrome-associated mucocutaneous lesions due to Leishmania braziliensis is described. Many vacuolated macrophages laden with amastigote forms of the parasite were found in the lesions. Leishmanin skin test and serology for leishmaniasis were both negative.

Evaluation of the stability and immunogenicity of autoclaved and nonautoclaved preparations of a vaccine against American tegumentary leishmaniasis.

This study was designed to evaluate the immunogenicity of autoclaved and nonautoclaved preparations of a vaccine composed of whole antigens from killed promastigotes of Leishmania amazonensis. Leishmanin skin-test (LST)-negative volunteers were immunized with either autoclaved or nonautoclaved vaccine preparations (32 and 36 subjects, respectively) that had been maintained at 4 degrees C for one year before the onset of this trial. Immunological tests were performed two days before and 40 days after vaccination.

T-cell responsiveness of American cutaneous leishmaniasis patients to purified Leishmania pifanoi amastigote antigens and Leishmania braziliensis promastigote antigens: immunologic patterns associated with cure.

Patients suffering from American cutaneous leishmaniasis were studied before therapy (active lesion) and at the end of therapy (cured patients). Assays of lymphocyte proliferative responses of peripheral blood mononuclear cells induced in vitro by Leishmania braziliensis promastigote antigens (Lb) or by three proteins (A-2/P-2, P-4, and P-8) derived from Leishmania pifanoi amastigotes were performed. Antigen-stimulated cells were harvested for CD4 and CD8 phenotype analysis and the levels of gamma interferon (IFN-gamma), interleukin 2 (IL-2) and interleukin 4 (IL-4) produced were also determined.

Tumor necrosis factor-alpha in human american tegumentary leishmaniasis.

Tumor necrosis factor-alpha (TNF-alpha) is a cytokine produced by activated macrophages and other cells. In order to verify whether the serum levels of TNF-alpha in American tegumentary leishmaniasis patients are associated with the process of cure or aggravation of the disease, 41 patients were studied: 26 cases of cutaneous leishmaniasis (CL) and 15 of mucocutaneous leishmaniasis (MCL). During active disease the serum levels of TNF-alpha of MCL patients were significantly higher than those of CL patients and control subjects (healthy individuals and cutaneous lesions from other etiologies).

Therapeutic effect of oral Kalanchoe pinnata leaf extract in murine leishmaniasis.

The effect of a leaf extract from Kalanchoe pinnata (Kp) was investigated in BALB/c mice infected with Leishmania amazonensis. Oral treatment with Kp significantly delayed onset of disease as compared to untreated mice or mice receiving Kp by the intravenous or topical routes. When initiated at early stages of infection, daily oral doses of 8 mg prevented lesion growth and the effect was long-lasting, comparable to the reference antileishmanial drug Glucantime.

Characterization of human T lymphocyte-mediated immune responses induced by a vaccine against American tegumentary leishmaniasis.

Forty-three Brazilians were immunized against American tegumentary leishmaniasis using a vaccine made of whole antigens from killed promastigotes of five American dermotropic Leishmania strains. None of the immunized subjects had a positive reaction in the Montenegro skin test (leishmanin) before vaccination, and 74% developed positive reactions in the skin test after vaccination. The proliferative responses of peripheral blood mononuclear cells (PBMC) induced by antigens from dermotropic Leishmania species were significantly higher after vaccination than before vaccination.

Does lipophosphoglycan enhance the T cell-stimulatory activity of lipophosphoglycan-associated proteins?

Peripheral blood mononuclear cells (PBMC) from 13 American tegumentary leishmaniasis (ATL) patients and two healthy controls were tested in in vitro proliferative response assays with crude lipophosphoglycan (LPG), purified LPG, LPG-associated proteins (LPGAP) and synthetic LPGAP from L. donovani. Cells from another group of six ATL patients were similarly tested with LPGAP obtained from L.

Effect of in vivo depletion of CD4+ T cells on experimental infection of susceptible BALB/c mice with Leishmania amazonensis.

The role played by CD4+ T lymphocytes in susceptible BALB/c mice infected with Leishmania amazonensis was investigated. Depletion of CD4+ T cells was achieved in experimentally infected mice by means of treatment with anti-CD4 monoclonal antibody (mAb), resulting in significant reductions in the size of lesions and in mortality when compared with control animals. Moreover, the parasite load in the depleted mice, as quantified by limiting dilution analysis, was about 10-times lower than in the control groups.

[Cancer in the female population in Brazil].

This study seeks to show the importance of cancer as a cause of morbidity and mortality among Brazilian women. Mortality data from the Health Ministry and incidence data from the six Brazilian Population Based Cancer Registries (Belém, Fortaleza, Recife, S. Paulo, Porto Alegre e Goiânia) were used.

Identification of GTPase genes in the protozoa parasites Trypanosoma cruzi and Leishmania amazonensis.

A PCR based assay was designed in order to amplify putative ras gene sequences of the GTPase superfamily eventually present in Leishmania amazonensis and Trypanosoma cruzi. A set of primers corresponding to the conserved motifs G1 and G3 of the GTP binding proteins was synthesized. Sequencing of six PCR products (three from Leishmania and three from Trypanosoma) identified, however, two other different GTPases.

Analysis of the human T cell responsiveness to purified antigens of Leishmania: lipophosphoglycan (LPG) and glycoprotein 63 (gp 63).

The responsiveness of peripheral blood lymphocytes from 15 cutaneous leishmaniasis patients and five healthy volunteers to purified surface antigens of Leishmania was studied. The following purified antigens were independently used as stimuli for lymphocyte proliferation in vitro: lipophosphoglycan of L. braziliensis, (Lb-LPG), lipophosphoglycan of L.

Synergy between activated Leishmania major-specific CD4+ T lymphocytes and bone-marrow-derived cells in the exacerbation of murine cutaneous leishmaniasis.

Mechanisms of exacerbation of murine cutaneous leishmaniasis mediated by Leishmania major-specific CD4+ T lymphocytes were studied. Using a limiting dilution assay for the quantification of Leishmania parasites, the infected tissues (footpad) of lethally irradiated mice were found to contain tenfold less parasites at four days of infection than the footpads of infected unirradiated animals. Injection of bone marrow cells depleted of T cells into irradiated mice at the site of infection led to an increase in parasite numbers to levels equivalent to those seen in unirradiated mice.

Indirect immunofluorescence test in New World leishmaniasis: serological and clinical relationship.

The indirect immunofluorescence test (IF) for anti-Leishmania antibodies (IgG and IgM) was performed with sera from the following groups of individuals: 214 cutaneous leishmaniasis patients, 28 healthy subjects with positive Montenegro's skin test (MST), 29 healthy subjects with negative MST and 16 visceral leishmaniasis patients. The first four groups came from a suburban area of Rio de Janeiro (Jacarepaguá) where cutaneous leishmaniasis caused by Leishmania braziliensis braziliensis is endemic. It was observed that IF-IgM titers were significantly higher amongst the cutaneous leishmaniasis patients with less than four months of disease as compared to those with longer periods and that IF-IgG titers were significantly higher in patients with multiple lesions as compared to those with single lesions.

Human american cutaneous leishmaniasis (Leishmania b. braziliensis) in Brazil: lymphoproliferative responses and influence of therapy.

The host defence to Leishmania parasites is believed to depend on cell-mediated immune responses. Three groups of inhabitants from an endemic area in Rio de Janeiro were studied: Group I consisted of 28 patients with cutaneous lesions, Group II of 28 healthy persons (without ulcers) but with positive Montenegro skin tests (MST) and Group III of 29 healthy persons with negative MST. The peripheral blood lymphocyte proliferative responses induced by leishmanial-antigens (Leishmania b.