Effect of b-Propiolactone treatment on the complement activation mediated by equine antisera

Reduction of complement activation through an alteration of the Fc fragment of immunoglobulins by b-propiolactone treatment was carried out in equine antisera raised against rabies virus, Bothrops venoms and diphtherial toxin. Results were evaluated by means of an anaphylactic test performed on guinea-pigs, and compared to the ones obtained with the same sera purified by saline precipitation (ammonium sulfate), followed or not by enzymatic digestion with pepsin. Protein purity levels for antibothropic serum were 184.5 mg/g and 488.5 mg/g in b-propiolactone treated and pepsin-digested sera, respectively. The recovery of specific activity was 100% and 62.5% when using antibothropic serum treated by b-propiolactone and pepsin digestion, respectively. The antidiphtherial and anti-rabies sera treated with b-propiolactone and pepsin presented protein purity levels of 5,698 and 7,179 Lf/g, 16,233 and 6,784 IU/g, respectively. The recovery of specific activity for these antisera were 88.8%, 77.7%, 100% and 36,5%, respectively. b-propiolactone treatment induced a reduction in complement activation, tested "in vivo", without significant loss of biological activity. This treatment can be used in the preparation of heterologous immunoglobulins for human use.

Identification of Toxoplasma gondii antigens involved in the IgM AND IgG indirect hemagglutination tests for the diagnosis of toxoplasmosis

Crude Toxoplasma gondii antigens represent raw material used to prepare reagents to be employed in different serologic tests for the diagnosis of toxoplasmosis, including the IgM and IgG indirect hemagglutination (IgG-HA and IgM-HA) tests. So far, the actual antigenic molecules of the parasite involved in the interaction with agglutinating anti-T. gondii antibodies in these tests are unknown. The absorption process of serum samples from toxoplasmosis patients with the IgG-HA reagent (G-toxo-HA) demonstrated that red cells from this reagent were coated with T. gondii antigens with Mr of 39, 35, 30, 27, 22 and 14 kDa. The immune-absorption process with the IgM-HA reagent (M-toxo-HA), in turn, provided antibody eluates which recognized antigenic bands of the parasite corresponding to Mr of 54, 35 and 30 kDa, implying that these antigens are coating red cells from this reagent. The identification of most relevant antigens for each type of HA reagent seems to be useful for the inspection of the raw antigenic material, as well as of reagent batches routinely produced. Moreover the present findings can be used to modify these reagents in order to improve the performance of HA tests for the diagnosis of toxoplasmosis

Peptic disease and Helicobacter pylori are highly prevalent in patients with the indeterminate form of chagas’ disease: report of 21 cases

Given that chagasic patients in the indeterminate form of this disease, can have abnormal motility of the digestive tract and immunologic abnormalities, we decided to assess the frequency of peptic disease and Helicobacter pylori (Hp) infection in these individuals. Twenty-one individuals, 13 males and 8 females, mean age 37.6 ± 11.1 years, were examined. Biopsies of the duodenum, antrum, lesser and greater gastric curvature and esophagus were performed. The endoscopic findings were of chronic gastritis in 20 (95.2%) patients, duodenal ulcer in 3 (14.3%), gastric and duodenal ulcer in 3 (14.3%), gastric ulcer alone in 1 (4.8%), esophagitis in 5 (23.8%), and duodenitis in 5 (23.8%). The diagnosis of infection by the Hp was done by the urease test and histologic examination. Hp infection was found in 20 (95.2%) individuals: in 20 out of them in the antrum, in 17 in the lesser curvature, and in 17 in the greater curvature. Hp was not found in the esophagus and duodenum. The only individual with no evidence of infection by Hp was also the only one with normal endoscopic and histologic examinations. The histologic examinations confirmed the diagnoses of gastric ulcer as peptic, chronic gastritis in 20 patients, duodenitis in 14, and esophagitis in 9. In this series the patients had a high frequency of peptic disease, which was closely associated with Hp infection

Evaluation of the allergenicity of spore and mycelia extracts of Pisolithus tinctorius

The antigenic and allergenic chemical analysis of spore and mycelia extracts of Pisolithus tinctorius was carried out. The spores were collected from basidiocarps in plantations of Eucalyptus spp and the mycelia from culture in MNM medium. With basis on the fungus growth curve, the mycelia masses were obtained after 10, 20, 30, and 40 days of incubation, which correspond, respectively, to the beginning, middle and end of the log phase, and beginning of the decline phase. The mycelia masses, together with the spores, were submitted to the action of three extractors (Coca, Tris-HCl, and ammonium bicarbonate). The contents of carbohydrates and proteins were determined. The SDS-PAGE electrophoretical analysis revealed separate fractions in these extracts, besides common fractions, in function of cultivation time and extraction methods. The selected extracts for the allergic tests were the ones with the highest number of fractions. The prick-tests were conducted in 374 patients – rural workers, eucalyptus plantation works and college students. The positivity to the "prick test" with the antigenic extract of P. tinctorius was, respectively, 3.78%, 28.20% and 6.40%. Most prick-test positive patients (82.75%) also presented symptoms of respiratory allergy (asthma and rhinitis). There was no reactivity difference when the spore and mycelia extracts were employed. The analysis of the positive patients’ sera revealed the presence of IgE specific to the P. tinctorius antigens. Since Pisolithus tinctorius is found as mycorrhyza of Eucalyptus spp, and this plant is used in reforestation in most countries, the importance of that fungus should be regarded as a possible cause of respiratory allergies, especially in occupationally exposed workers

Trypanosoma cruzi: chemotherapy with benznidazole in mice inoculated with strains from Paraná State and from different endemic areas of Brazil

Strains of Trypanosoma cruzi from different geographical areas have shown different levels of susceptibility to trypanocidal drugs. The susceptibility in vivo to benznidazole was investigated in eighteen strains of T. cruzi. Twelve were isolated from chronic chagasic patients from different Chagas’ disease endemic areas. The other six strains were isolated from the northwestern region of Paraná state; two of them from patients three from triatomines (Triatoma sordida) and one from wild reservoir (Didelphis sp.). To test drug the infected mice were divided into two groups of twenty. One group was treated with benznidazole for twenty consecutive days and the other group was used as untreated control. The treatment began after detection of the infection by direct blood examination or haemoculture. The control of cure was done through haemoculture and indirect immunofluorescence test. The drug eliminated the inflammatory lesions of the skeletal muscle of mice considered cured and from the heart of most of them. Moreover, the inflammatory lesions were reduced in treated but not cured animals. The T. cruzi strains studied showed a gradient of drug susceptibility that varied from 0% to 100%. Ten strains were considered sensitive to the treatment (61 to 100% of cure), one strain was partially sensitive (50% of cure) and seven strains were considered resistant to the treatment (0 to 40% of cure). This variation was observed both in strains of T. cruzi isolated from domestic and sylvatic cycles

Coccidioidomycosis in Brazil. A case report

Coccidioidomycosis is an endemic infection with a relatively limited geographic distribution: Mexico, Guatemala, Honduras, Colombia, Venezuela, Bolivia, Paraguai, Argentina and the southwest of the United States. In these countries, the endemic area is restricted to the semiarid desert like regions which are similar to the northeast of Brazil. Case report: The patient is a 32 year-old male, born in the state of Bahia (Northeast of Brazil) and has been living in São Paulo (Southeast) for 6 years. He was admitted at Hospital das Clínicas, at the Department of Pneumology in October 1996, with a 6 month history of progressive and productive cough, fever, malaise, chills, loss of weight, weakness and arthralgia in the small joints. Chest x-rays and computerized tomography disclosed an interstitial reticulonodular infiltrate with a cavity in the right upper lobe. The standard potassium hydroxide preparation of sputum and broncoalveolar lavage demonstrated the characteristic thickened wall spherules in various stages of development. Sabouraud dextrose agar, at 25° C and 30° C showed growth of white and cottony aerial micelium. The microscopic morphology disclosed branched hyphae characterized by thick walled, barrel shaped arthroconidia alternated with empty cells. The sorological studies with positive double immunodiffusion test, and also positive complement fixation test in 1/128 dilution confirmed the diagnosis. The patient has been treated with ketoconazole and presents a favorable clinical and radiological evolution

IgM and IgA Antibody Responses in 12 Cases of Human Acquired Toxoplasmosis

The persistence, in some subjects, of specific IgM antibodies to Toxoplasma gondii for several months after the acute phase of infection has complicated the interpretation of serological test results for toxoplasmosis. Several reports have emphasized the value of the detection of Toxoplasma-specific IgA antibodies for the diagnosis of acute toxoplasmosis. In this article, we report the follow-up profiles of Toxoplasma-specific IgM and IgA antibodies in serum samples obtained from 12 patients at various intervals after the onset of the clinical manifestations of infection. IgM antibodies were detected by the indirect immunofluorescence (IIF) test, antibody capture enzyme-linked immunosorbent assay (cELISA) and enzyme-mediated chemilluminescent technique (CmL). IgA antibodies were quantified by the direct ELISA (dELISA) and cELISA procedures. As defined by the manufacturer of the cELISA test for IgA used, most patients with acute toxoplasmosis have antibody levels > 40 arbritary units per ml (AU/ml). At values > 40 AU/ml, the cELISA for IgA detected significant antibody levels for a shorter time than the other techniques used for IgM and IgA detection. However, IgA levels £ 40 AU/ml do not exclude the possibility of acute toxoplasmosis since such levels can be reached very soon after infection with T. gondii. The results obtained in the present study show that the serological diagnosis of acute toxoplasmosis may not be such an easy task. Our data suggest that use of the IgA-cELISA concomitantly with IgM antibody screening could permit, in some circumstances, a more efficient diagnosis of acute acquired toxoplasmosis

Streptococcus pneumoniae and Haemophilus influenzae as etiological agents of conjunctivitis outbreaks in the region of Ribeirão Preto, SP, Brazil

In the study of conjunctivitis outbreaks occurring from September 1994 to September 1996 in the region of Ribeirão Preto, conjunctival exudates of 92 patients were cultivated in Instituto Adolfo Lutz Laboratory I, Ribeirão Preto. Most cases occurred in the age range 2-7 years. The etiological agents which were most frequently isolated from the analyzed cases were: Streptococcus pneumoniae and Haemophilus influenzae, in 40.22% and 21.74%, respectively. 51.35% of the S. pneumoniae isolated strains were not typable. The oxacillin-resistant S. pneumoniae strains were submitted to the minimum inhibitory concentration test (MIC) and three of them presented intermediate resistance, whereas only one was highly resistant to penicillin.