Associação de hipovitaminose D com Lúpus Eritematoso Sistêmico e inflamação / Association of hypovitaminosis D with Systemic Lupus Erythematosus and inflammation

Introdução: Atualmente, é descrita elevada prevalência de hipovitaminose D no Lúpus Eritematoso Sistêmico (LES), a qual se associa a algumas manifestações clínicas e maior atividade inflamatória. Objetivo: Avaliar a associação entre insuficiência de vitamina D com LES e marcadores inflamatórios. Métodos: Estudo transversal, tendo sido avaliados 45 pacientes com LES e 24 controles sem a doença. Níveis de 25-hidroxivitamina D [25(OH)D] menores que 30 ng/mL foram considerados insuficientes. A atividade da doença foi avaliada pelo Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Foram avaliados, ainda, proteína C reativa ultrassensível (PCRus) e interleucina-6 (IL-6) para verificação do status inflamatório. Para avaliação do envolvimento renal, foram realizados análise de elementos anormais e sedimentoscopia urinárias (EAS), hematúria e piúria quantitativas, proteinúria e depuração de creatinina em urina de 24 horas e anti-DNA de dupla hélice sérico. Resultados: A prevalência de insuficiência de 25(OH)D foi de 55% nos pacientes lúpicos e 8% nos participantes controles (p = 0,001). A mediana da 25(OH)D foi menor nos pacientes do que no grupo controle. Os pacientes com insuficiência de 25(OH)D apresentaram níveis mais elevados de IL-6 e maior prevalência de hematúria ao EAS. Não houve correlação entre vitamina D, nefrite lúpica e SLEDAI. Conclusão: Em nosso estudo, a insuficiência de vitamina D foi mais prevalente em pacientes com LES e se associou com níveis mais elevados de IL-6 e presença de hematúria. .

Introduction: Nowadays it is described a high prevalence of hypovitaminosis D in Systemic Lupus Erythematosus (SLE), which is associated with some clinical manifestations and increased inflammatory activity. Objective: To evaluate the association between vitamin D insufficiency with SLE and inflammatory markers. Methods: Cross-sectional study, in which have been evaluated 45 SLE patients and 24 controls without the disease. Levels of 25-hydroxyvitamin D [25(OH) D] less than 30 ng/mL were considered inadequate. Disease activity was assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). High sensitivity C reactive protein (hsCRP) and interleukin-6 (IL-6) were evaluated for verification of the inflammatory status. For assessment of renal involvement, analysis of abnormal elements and urinay sediment (AES), quantitative hematuria and pyuria, proteinuria and creatinine clearance in 24-hour urine and serum anti-double stranded DNA were performed. Results: The prevalence of 25(OH)D insufficiency was 55% in SLE patients and 8% in the controls participants (p = 0.001). The median of 25(OH)D was lower in patients than in controls. Patients with insufficient 25(OH)D had higher levels of IL-6 and higher prevalence of hematuria in the AES. There was no correlation between vitamin D and SLEDAI or lupus nephritis. Conclusion: In our study, vitamin D deficiency was more prevalent in patients with SLE and was associated with higher levels of IL-6 and hematuria. .

Determinación de la especificidad de IgA sérica producida en respuesta a antígenos de Leishmania (Leishmania) mexicana en leishmaniosis murina / Determination of the specificity of seric IgA produced in response to antigens of Leishmania (Leishmania) mexicana in murine leishmaniasis

En la leishmaniosis experimental, la función de los anticuerpos no está completamente clara, ya que algunos autores consideran que dichas proteínas no participan en la protección contra la infección; sin embargo, estudios histopatológicos en lesiones con leishmaniosis humana y experimental, muestran infiltrados de células plasmáticas positivas para IgA y secreción de IgM, IgG e IgA que podrían mediar la formación de complejos inmunológicos con antígenos parasitarios o propios, favoreciendo la necrosis lo que conlleva a la eliminación del parásito. En este trabajo se determinó si la IgA sérica en el modelo murino posee reactividad específica contra antígenos de Leishmania (Leishmania) mexicana de utilidad diagnóstica. Para ello, se utilizaron ratones susceptibles y resistentes a leishmaniosis cutánea, demostrándose mediante ELISA indirecta que la IgA sérica de ratones susceptibles es elevada en comparación con la producida por ratones resistentes. Aunque otros estudios en modelos murinos demuestran que la IgG sérica de ratones infectados con L. (L) mexicana presenta reactividad cruzada con antígenos parasitarios no relacionados obtenidos de Trypanosoma cruzi, al analizar la especificidad de IgA por antígenos de L. (L) mexicana y T. cruzi, mediante Western Blot, se demostró que la IgA sérica de ratones infectados con T. cruzi también reaccionan con antígenos de L. (L) mexicana, estos hallazgos sugieren que la IgA puede ser útil para el manejo clínico y pronóstico de la enfermedad.

In experimental leishmaniasis, the role of antibodies is not entirely clear, as some authors consider that these proteins are not involved in protection against infection. However, histopathological studies in human and experimental leishmaniasis lesions, show plasma cell infiltrates positive for IgA and secretion of IgM, IgG and IgA could mediate the formation of immune complexes with parasite antigens or self components, favoring necrosis leading to the elimination of the parasite. In this study, we determined if the serum IgA in the murine model has specific reactivity against antigens of Leishmania (Leishmania) mexicana of diagnostic utility. To do this, we used mice either susceptible or resistant to cutaneous leishmaniasis, and demonstrated by indirect ELISA that serum IgA is elevated in susceptible mice compared with that produced by resistant mice. Although other studies in murine models show that the serum IgG from mice infected with L. (L) mexicana present cross reactivity with unrelated parasite antigens derived from Trypanosoma cruzi, the analysis of the specificity of IgA by antigens of L. (L) mexicana and T. cruzi, by Western Blot, showed that the IgA serum of mice infected with T. cruzi reacts too with antigens of L. (L) mexicana. These findings suggest that IgA may be useful for the clinical management and prognosis of the disease.

Sera of Chagasic patients react with antigens from the tomato parasite Phytomonas serpens

The genus Phytomonas comprises trypanosomatids that can parasitize a broad range of plant species. These fagellates can cause diseases in some plant families with a wide geographic distribution, which can result in great economic losses. We have demonstrated previously that Phytomonas serpens 15T, a tomato trypanosomatid, shares antigens with Trypanosoma cruzi, the agent of human Chagas disease. Herein, two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) were used to identify proteins of P. serpens 15T that are recognized by sera from patients with Chagas disease. After 2D-electrophoresis of whole-cell lysates, 31 peptides were selected and analyzed by tandem mass spectrometry. Twenty-eight polypeptides were identifed, resulting in 22 different putative proteins. The identifed proteins were classifed into 8 groups according to biological process, most of which were clustered into a cellular metabolic process category. These results generated a collection of proteins that can provide a starting point to obtain insights into antigenic cross reactivity among trypanosomatids and to explore P. serpens antigens as candidates for vaccine and immunologic diagnosis studies.

Effects of Toxoplasma gondii and Toxocara canis Antigens on WEHI-164 Fibrosarcoma Growth in a Mouse Model

Cancer is the main cause of death in developed countries. However, in underdeveloped countries infections and parasitic diseases are the main causes of death. There are raising scientific evidences indicating that parasitic infections induce antitumor activity against certain types of cancers. In this study, the effects of Toxoplasma gondii and Toxocara canis egg antigens in comparison with Bacillus Calmette Guerin (BCG) (known to have anticancer distinctive) on WEHI-164 fibosarcoma transplanted to BALB/c mice was investigated. Groups of 6 male BALB/c mice injected with T. gondii antigen, BCG, or T. canis egg antigen as case groups and alum alone as control groups. All mice were then challenged with WEHI-164 fibrosarcoma cells. The mice were examined for growth of the solid tumor and the tumor sizes were measured every other day up to 4 wk. The mean tumor area in T. gondii, BCG, or alum alone injected mice in 4 different days of measurements was 25 mm2, 23 mm2, and 186 mm2 respectively. Also the mean tumor area in T. canis injected mice in 4 different days was 25.5 mm2 compared to the control group (alum treated) which was 155 mm2. T. gondii parasites and T. canis egg antigens induced inhibition of the tumor growth in the fibrosarcoma mouse model. We need further study to clarify the mechanisms of anti-cancer effects.

Identification of amastigote-specific antigens of Leishmania donovani using kala-azar patient sera.

Antigenic characterization of the soluble fraction of axenic amastigotes of Leishmania donovani ( strain Dd8, causative agent of Indian kala-azar) and their comparison with promastigotes is reported. The axenic amastigotes were assessed for their immunological status employing anti-A2 monoclonal antibody which is extremely specific for L. donovani amastigotes. SDS-PAGE of 35[S] methionine labeled proteins of the two parasite stages exhibited few stage specific and some conserved antigens in both the stages. An increased synthesis of heat shock proteins was observed in axenic amastigotes. Western blot experiments employing sera of kala azar positive patients identified immunodominent antigens of 116,83,26 and 12 kDa in axenic amastigotes which were not present in promastigotes. These amastigote stage specific antigens may have immense potential in immunodiagnosis and prophylaxis of kala-azar.

Detection of immunoglobulin G in the lung and liver of hamsters with visceral leishmaniasis

Several organs are affected in visceral leishmaniasis, not only those rich in mononuclear phagocytes. Hypergammaglobulinemia occurs during visceral leishmaniasis; anti-Leishmania antibodies are not primarily important for protection but might be involved in the pathogenesis of tissue lesions. The glomerulonephritis occurring in visceral leishmaniasis has been attributed to immune complex deposition but in other organs the mechanism has not been studied. In the current study we demonstrated the presence of IgG in the lung and liver of hamsters with visceral leishmaniasis. Hamsters were injected intraperitoneally with 2 x 10(7) amastigotes of Leishmania (Leishmania) chagasi and the presence of IgG in the liver and lung was evaluated at 7, 15, 30, 45, 80 and 102 days postinfection (PI) by immunohistochemistry. The parasite burden in the spleen and liver increased progressively during infection. We observed a deposit of IgG from day 7 PI that increased progressively until it reached highest intensity around 30 and 45 days PI, declining at later times. The IgG deposits outlined the sinusoids. In the lung a deposit of IgG was observed in the capillary walls that was moderate at day 7 PI, but the intensity increased remarkably at day 30 PI and declined at later times of infection. No significant C3 deposits were observed in the lung or in the liver. We conclude that IgG may participate in the pathogenesis of the inflammatory process of the lung and liver occurring in experimental visceral leishmaniasis and we discuss an alternative mechanism other than immune complex deposition

An appraissl of laboratory methods addressing roll back malaria

Os métodos de laboratório säo ferramentas importantes para se alcançar as principais metas para o controle da malária, que säo: a) Diagnóstico precoce e tratamento rápido; b) métodos preventivos, incluindo o controle do vetor; c) prevencäo e controle de epidemias e d) capacitaçäo de países endêmicos para pesquisa e controle da doença. Estes säo aplicados na prática clínica para o diagnóstico individual e para o seguimento de pacientes sob tratamento específico anti-malárico. Também säo úteis em estudos epidemiológicos, pois permitem medir infecções atuais e passadas da populaçäo, assessorar a suscetibilidade à drogas, avaliar o estado funcional da populaçäo e detectar a presença de infecçäo no mosquito. Para a realizaçäo do diagnóstico precoce na prática clínica deve-se utilizar métodos para detecçäo de plasmódios ou de seus componentes (antígenos ou DNA) em hemácias. Para estudos epidemiológicos, uma maior variedade de métodos podem ser utilizados, pois o tempo näo é crucial, e podem ser feitos em um laboratório central com equipamentos especializados e automatizados. Neste artigo, avaliamos criticamente os métodos de laboratório disponíveis para: a) Detecçäo de Plasmodium em hemácias; b) detecçäo de antígenos de Plasmodium em hemácias e soro; c) detecçäo do DNA de Plasmodium; d) detecçäo de anticorpos anti-Plasmodium; e) avaliar o estado imune e e) detecçäo de esporozoítas no mosquito.

Protection against Toxoplasmosis in Mice Immunized with Different Antigens of Toxoplasma gondii Incorporated into Liposomes

Different toxoplasma antigens were entrapped within liposomes and evaluated, in this form, for their ability to protect Swiss mice against toxoplasma infection: soluble tachyzoite antigen (L/TAg), tissue cyst (L/CAg), tachyzoite plus tissue cyst (L/TCAg) or purified antigen of tachyzoite (L/pTAg). The protein used in L/pTAg was purified from tachyzoites using a stage-specific monoclonal antibody which reacted at a molecular weight of 32 kD in SDS PAGE and silver stain using reduced condition. To compare the immuno-adjuvant action of liposomes and of Freund's Complete Adjuvant (FCA), another group of mice was immunized with soluble tachyzoite antigen (STAg) emulsified in FCA (FCA/TAg). Control groups were inoculated with (STAg) alone, phosphate-buffered saline (PBS), FCA with PBS (FCA/PBS) and empty liposomes (L/PBS). Mice were inoculated subcutaneously with these antigens six, four and two weeks before a challenge with 80 tissue cysts of the P strain of Toxoplasma gondii orally. All mice immunized with or without adjuvant showed a humoral response, as measured by Elisa. However, no correlation was found between antibody titer and protection against the challenge. All mice immunized with L/pTAg or L/TCAg survived (100), whereas 80 percent and 90 percent of mice from groups which received respectively PBS or FCA/PBS and L/PBS died. All mice immunized with antigens entrapped within liposomes (L/TAg, L/CAg, L/TCAg and L/pTAg) showed low numbers of intracerebral cysts

A monoclonal antibody-based test system for detection of Entamoeba histolytica-specific coproantigen.

BACKGROUND: Diagnosis of amebiasis based on stool microscopy or demonstration of anti-amebic antibodies has limitations. A diagnostic system based on demonstration of the parasite product in clinical specimens holds promise. METHODS: Murine monoclonal antibodies were developed against an Entamoeba histolytica-specific coproantigen. A monoclonal antibody (MoAb) 3D10 was employed in a double-antibody sandwich microELISA system for the detection of amebic coproantigen in fecal specimens. The system was evaluated in three groups of subjects: 63 patients with intestinal amebae, 27 with non-amebic parasitosis, and 57 apparently healthy controls. RESULTS: The MoAb 3D10 belonged to IgG1 isotype and recognized three antigens, with mol. wt. 36, 25 and 17 kDa in the crude extract of E. histolytica (HM1-IMSS), and an amebic coproantigen with MW 36 kDa in the stool supernatant from patients with intestinal amebae. The coproantigen was detected in the stool eluates of 56 (89%) patients with intestinal amebae and in none of the stool eluates from other subjects, thereby giving this system a sensitivity of 89% and specificity of 100% for the detection of intestinal amebae. CONCLUSIONS: This monoclonal antibody recognizes as intact epitope on the E. histolytica-specific coproantigen. The validity of the MoAb-based microELISA system needs to be established.

T Cell response of asymptomatic Leishmania chagasi infected subjects to recombinant leishmania atigens

In areas of Leishmania chagasi transmission the ability to control leishmania infection is associated with IFN-y production. In visceral leishmaniasis down-regulation of T cell responses is mediated by interleukin-10 (IL-10). In this study we evaluated the lymphoproliferative response IFN-y and IL-10 production on lymphocyte cultures stimulated with recombinant leishmania antigen in subjects with asymptomatic L. chagasi infection difference in the lymphoproliferative response of the subjects with asymptomatic infection as compared to patients with visceral leismaniasis and heslthy subjects with respect to crude antigens (p<0.01), gp-63 (p<0.05) and hsp-70 (p<0.01), as well as between asymptomatic L. chagasi infected subjects and patients with visceral leishmaniasis with respect to the response to all antigens tested. The IFN-y production observed in the group with asymptomatic infection with all the three recombinant antigens tested was higher (p<0.01) than that observed in patients with visceral leishmaniasis and in healthy subjects. Furthermore, in individuals with asymptomatic infection, IL-10 levels in cultures stimulated with recombinant antigens were very low. This study shows that lymphocytes from individuals with asymptomatic L. chagasi infection are able to recognize recombinant leishmania antigens with production of a cytokine that is associated with leishmania killing.

Partial protection of mice against Trypanosoma cruzi after immunizing with the TcY 72 antigenic preparation

A 72 kDa Trypanosoma cruzi glycoprotein recognized by the 164C11 monoclonal antibody (IgM isotype) was purified by preparative electrophoresis. The antigenic preparation obtained, named TcY 72, was used to immunize C57Bl/10 mice. The following results were observed after immunization: (1) induction of higher titres of IgG than IgM antibodies, as evaluated by indirect immunofluorescence; (2) significant DTH after infection of epimastigotes in mice footpads: (3) peak parasitemia in immunized mice was significantly reduced and animals were negative by 13 days post-infection, although the mice still succumb to infection: (4) the phenotypic analysis of spleen cell populations showed a decrease in the CD4/CD8 ratio in immunized mice. Taken as a whole, these findings indicate that TcY 72 is immunogenic and potentially important for protective immunity.

Detección de antígeno de Giardia en materia fecal de Meriones unguiculatus (Gerbil) por ELISA utilizando anticuerpos policlonales / Detection of Giardia antigen in Meriones unguiculatus (Gerbil) faeces by ELISA using policlonal antibodies

La identificación de Giardia lamblia en heces puede fracasar debido a la eliminación intermitente de quiste y/o trofozoítos del parásito. Actualmente, puede recurrirse a la detección de antígeno del parásito en materia fecal comprobando que el huésped está infectado y/o enfermo circunstancia que ofrece una gran ventaja para el tratamiento oportuno de paciente y de manera indirecta para el control de la enfermedad de las personas que se encuentran alredodor de éste. En este trabajo, se estandarizó y evaluó el ensayo inmunoenzimático ELISA utilizando anticuerpos policlonales anti-quiste y antitrofozoíto de cepas colombianas de Giardia desarrollados en conejo para la detección de antígeno del parásito en heces de gerbils (Meriones unguiculatus), modelo animal para estudios de giardiasis, como paso previo para la detección de antígeno en heces humanas. Para ello, se purificaron quistes de Giardia a partir de heces humanas mediante gradientes de sucrusa y percoll para infectar gerbils y obtener periódicamente quistes y trofozoítos del parásito. Posteriormente con la finalidad de obtener anticuerpos policlonales anti-quiste y anti-trofozoítos del parásito, se inocularon conejos independientemente con antígeno de quiste y trofozoíto de Giardia. Se realizó una mezcla de anticuerpos policlonales anti-quiste y anti-trofozoíto de Giardia, en una proporción 1:2 respectivamente, previa purificación de éstos mediante precipitación secuencial con ácido caprílico y sulfato de amonio y se eleboró un conjugado con parte de los anticuerpos policlonales uniéndole a éstos fosfatasa alcalina. Finalmente se realizó el diagnóstico parasitológico a 47 heces de gerbils infectados previamente con quistes de giardia y 55 heces de gerbils no infectados. Se observó quistes de Giardia en las 47 heces de gerbils infectados (muestras positivas) y ningún parásito intestinal en los animales no infectados (muestra negativas). La concentración óptima de anticuerpos policlonales fue de 40 µgr/ml y la dilución óptima de conjugado fue de 1:400. El valor de absorbancia (punto de corte) que diferenció una muestra negativa de una positiva fue de 0.142. Los parámetros de la prueba fueron: sensibilidad: 91 por ciento, especificidad: 93 por ciento, valor predictivo positivo: 91 por ciento y valor predictivo negativo: 93 por ciento. El ELISA estandarizado y evaluado servirá como base para la detección de antígeno de Giardia en heces humanas

Detection of hydatid antigen in human cyst fluid by reverse latex agglutination test

The present work studied the use of reverse latex agglutination [RLA] test in the diagnosis of CE as a test that could directly detect hydatid antigen in human cyst fluid samples. The results were reliable when compared with the direct microscopic examination of cyst fluid samples. Also, it was more reliable than indirect hemagglutination test as it showed 100% sensitivity. No false positive reaction was observed with samples from cystic tumors with a resultant specificity of 100%. Moreover, the test is easy to perform with a visually interpreted results within 2-3 minutes. The reagents are inexpensive, stable and easily available. These merits make the RLA test suitable for the diagnosis of CE, particularly in suspected cases with seronegative results or cases with sterile cysts

Trypanosoma cruzi: amastigote polymorphism defined by monoclonal antibodies

We have raised monoclonal antibodies (mAbs) directed towards amastigote forms of Trypanosoma cruzi, and shown that mAbs 1D9 and 4B9 are carbohydrate while mAb 4B5 activity is resistant to periodate oxidation of the antigen. Here we used an ELISA to quantitate and compare the expression of surface epitopes on fixed parasites among different parasite isolates. The expression of markers varied among T. cruzi amastigotes isolated from infected cells or after extracellular differentiation of trypomastigotes. Moreover, we also observed an extensive polymorphic expression of these epitopes among amastigotes derived from different strains and clones. For instance, mAb 2C2 strongly and evenly reacted with 9 strains and clones (G, Y, CL, Tulahuen, MD, and F, and clones Sylvio X-10/4, D11, and CL.B), with absorbance at 492 nm (A492 nm) from 0.6 to 0.8. By contrast, mAb 4B5 had a higher expression in Tulahuen amastigotes (around 0.9 at 492 nm) whereas its reactivity with amastigotes from clones CL.B, Sylvio X-10/4 and D11 was much lower (around 0.4). mAb 1D9 displayed an interesting pattern of reactivity with amastigotes of the different strains and clones (A492 nm of G>D11ÝSylvio X-10/4 = MD>Tulahuen = F = Y>CL>CL.B). Finally, we observed that mAb 4B9 had the lowest reaction with the parasites studied, with higher values of A492 nm with Y strain (around 0.6) and lower values with Tulahuen, F and CL.B strains (around 0.2). Immunoblotting analysis also showed extensive variations among amastigotes of the various parasite isolates and mAbs 4B9, 1D9 and 4B5 revealed significant differences in expression between clones and parental strains. These data describe a previously uncharacterized polymorphism of T. cruzi amastigote surface components

Avaliação de uma nova microtécnica de fixação de complemento (Garcia & Sotelo, 1991) para o diagnóstico da doença de Chagas crônica com diferentes preparaçoes antigênicas / The evaluation of a new complement fixation microtechnic (Garcia & Sotelo, 1991) for the diagnosis of chronic Chagas disease with different antigenic preparations

No presente trabalho, avalia-se a nova fixação de complemento, comparativamente à imunofluorescência indireta, para o diagnóstico da doença de Chagas crônica, utilizando um extrato aquoso de formas epimastigotas do Trypanosoma cruzi e três extratos etanólicos: um de epimastigotas, um de tripomastigotas e outro de amastigotas obtidas de cultura. Empregaram-se 236 amostras testadas por imunofluorescência indireta: 109 positivas (20 com diagnóstico parasitológico) e 127 amostras negativas (96 de doadores de sangue e 31 de portadores de outras patologias). Os resultados mostraram que é possível obter reação positiva em amostras diluídas até 1:16. Os melhores limiares de reatividade encontrados foram a diluição 1:4 para o extrato etanólico de amastigotas e 1:2 para os demais antígenos. Os índices de correlação entre a nova fixação de complemento e imunofluorescência indireta indicaram o extrato etanólico de epimastigotas como o antígeno mais adequado para fins de diagnóstico entre as preparações testadas, tendo apresentado índice de co-positividade com a imunofluorescência indireta de 0,92207 e índice de co-negatividade de 0,90000. Conclui-se que a nova fixação de complemento mostrou-se ser uma microtécnica semi-quantitativa rápida, sensível, barata e de fácil execução, aplicável ao diagnóstico da doença de Chagas crônica.

From this present data it has been evaluated a new complement fixation test, comparatively to indirect immunofluorescence to diagnose chronic Chagas' disease, utilizing one watery extract of epimastigotes of Trypanosoma cruzi and three other ethanolic extracts: one from epimastigotes, one from tripomastigotes and a third one of amastigotes obtained from cultures. Utilizing 236 serum samples indirect immunofluorescence test was performed: 109 positives (20 of them with positive parasitologic diagnostic) and 127 negatives (96 of healthy blood donors and 31 with other diseases). The results have showed that is possible a positive reaction in diluted samples up to 1:16. The best limits of reactivity found were the dilutions 1:4 for the ethanolic extract of amastigotes and 1:2 for the others antigens. The correlation index among the new complement fixation test and indirect immunofluorescence test showed that the ethanolic extract from epimastigotes was the best antigen to be utilized to diagnosis purposes. Its co-positivity index with indirect immunofluorescence was 0.92207 and the co-negative index was 0.90000. Concluding, the new complement fixation test showed itself as a fast, sensible, easily applicable semiquantitative microtechnique to the diagnosis of chronic Chagas' disease.

The ICT Malaria Pf: a simple, rapid dipstick test for the diagnosis of Plasmodium falciparum malaria at the Thai-Myanmar border.

The ICT Malaria Pf test for the detection of Plasmodium falciparum infection was evaluated in the diagnosis of 305 patients with fever who were admitted to a hospital located on the Thai-Myanmar border. All patients were admitted for at least one week to exclude reinfection. The test was performed using admission blood samples collected into ethylenediaminetetraacetic acid. The sensitivity, specificity and accuracy of the test were 92.7%, 95.1% and 94.7% respectively, compared to standard microscopic diagnosis. The ICT Malaria Pf test is an accurate method for the diagnosis of P. falciparum infection. Its simplicity and rapidity make it particularly appropriate for use in remote areas where microscopic examination of blood films is unavailable.

Evaluation of Leishmania antigens preparation and storage for use in enzyme immunoassays

The influence of time and temperature on the storage of an alkaline antigen of L. major-like and L.(V.) braziliensis promastigotes added or not of a proteases inhibitor (PMSF) was evaluated by means of an IgG-ELISA. Antibodies in assays using L. major-like antigen stored at -20 degrees C for 6 months had a statistically lower geometric mean titer (GMT) and different 95% confidence interval limits (CL) than antigens stored otherwise, as assessed by the [quot ]t[quot ] statistic. The PMSFL. major-like antigen after storage for 6 months at a temperature of 4 degrees C had the same GMT and 95% CL displayed at time zero as well as when storage for 4 and 6 months at -20 degrees C. Significant differences were not found when L.(V.) braziliensis antigens were stored at times and temperatures mentioned; the PMSF antigen stored for 2 months at -70 degrees C resulted in a lower serum GMT and 95% CL than any other, as assessed by the [quot ]t[quot ] statistic. Antigen performance did not show any statistical difference associated to the addition of PMSF within the same species; the largest difference between antigens was that between PMSF-L. (V.) braziliensis and L. major-like without PMSF.

A influência do tempo e temperatura de estocagem de antígenos alcalinos de promastigotas de L. major-like e L. (V.) braziliensis adicionados ou não de um inibidor de proteases foi avaliada por meio de reações de IgG-ELISA. A reação que empregava o antígeno de L. major-like estocado por 6 meses a -20oC mostrou que médias geométricas dos títulos (MGT)e intervalos de confiança 95% (IC 95%) eram estatisticamente inferiores àquelas obtidas com antígenos estocados em outros intervalos de tempo, medido pela estatística "t". O antígeno PMSF-L. major-like depois de 6 meses de estocagem à temperatura de 4oC tinha a mesma MGT e IC 95% do tempo zero assim como quando ele foi estocado a -20oC por 4 e 6 meses. Não foram observadas diferenças estatisticamente diferentes com os antígenos de L. (V.) braziliensis estocados nas mesmas condições de tempo e temperatura exceto o antígeno PMSF estocado por 2 meses a -70oC que apresentou MGT e IC 95% inferiores a quaisquer outras como aferido pela estatísitca "t". Quando comparados os desempenhos dos antígenos não houve direrenças estatisticamente significantes entre a adição ou não de PMSF para qualquer dos parasitas. A análise do cruzamento entre antígenos mostrou que a maior diferença netre eles foi a do contraste entre L. (V.) braziliensis adicionado de PMSF e L. major-like sem adição de PMSF.