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Paracoccidioidomycosis (PCM) is a systemic mycosis caused by the fungus Paracoccidioides brasiliensis (S1, PS2, and PS3) and by the new species, P. lutzii. Considering that genetic differences in the Paracoccidioides genus could elicit distinct immune responses by the host, current research investigated serum IgG levels to antigens from P. brasiliensis B339 (S1), P. brasiliensis LDR3 (PS2), and atypical strain LDR2 ( P. lutzii), in patients with chronic PCM from the northern and west regions of Paraná, Brazil ( n = 35). Cell-free antigen (CFA) and high molecular mass fraction (hMM) were produced from each strain. Samples were analyzed by ELISA and immunodiffusion (ID). ELISA positivity using CFA: B339-100 %, LDR3-83 %, and LDR2-74 %. Response to CFA from B339 was more intense ( p < 0.05), while there was no difference between LDR3-LDR2. IgG anti-hMM was higher for antigens from B339 or LDR3, when compared with LDR2 ( p < 0.05). There was a positive correlation for each strain between CFA-hMM and for hMM between B339-LDR3 and LDR3-LDR2. ID positivity with CFA: B339-63 %, LDR3-66 %, and LDR2-60 %. We conclude that the intensity of reaction of the patients’ sera varies with the strain used; hMM influences tests that use CFA, independently of strain; using ID, positive rates were very similar, but there was a large number of false negative results; ELISA tests using antigens from P. brasiliensis S1 were able to detect a larger number of patients than PS2 and P. lutzii (which had a considerable number of false negative results), and therefore, its use may be more appropriate in this region of Brazil. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the immune response of young dogs experimentally infected with Paracoccidioides brasiliensis. Six dogs were infected intravenously with P. brasiliensis and one control dog was inoculated with sterile saline. The infected animals were sacrificed in groups of two at 1. 6 and 12 months after infection. During the experimental period, the immune responses of the dogs to the fungus were followed by ELISA (IgM and IgG), by the immunodiffusion test and by the skin test with gp43. After killing the dogs, samples from several organs were submitted to histopathological analysis (H&E and Grocott stains) but the fungus was not observed in any tissue. Attempts to isolate the fungus from these tissue samples were also unsuccessful. All infected dogs, except one, reacted positively to the immunodiffusion and skin tests. All infected dogs showed a humoral immune response to the gp43 antigen detected by ELISA. The IgM and IgG response peaked by the first and second month, respectively. We conclude that young dogs appear to be resistant to the development of paracoccidioidomycosis. [ABSTRACT FROM AUTHOR]

An indirect competitive enzyme-linked immunosorbent assay (ELISA) method using a monoclonal antibody for deoxynivalenol (DON) detection in wheat and flour was standardised and validated (detection limit = 177.1 µg kg(-1)) and its performance was compared with LC-MS, quantification limit =140 µg kg(-1)). DON recovery ranged from 88.7% to 122.6% for wheat grain and from 70.6% to 139.3% for flour. Among the 38 wheat samples evaluated, DON was detected in 29 samples (76.3%) by ic-ELISA (281.6-12 291.4 µg kg(-1)) and in 22 samples (57.9%) by LC-MS (155.3-9906.9 µg kg(-1)). The 0.93 correlation coefficient between ic-ELISA and LC-MS data in 19 positive DON wheat samples demonstrated the reliability and efficiency of ic-ELISA. Results indicated that standardised ic-ELISA was suitable for DON screening in wheat samples and the need for continuous monitoring of mycotoxin levels in foodstuffs.

The dimorphic fungus Paracoccidioides brasiliensis is the etiological agent of paracoccidioidomycosis, a human granulomatous disease. Recently the first case of natural disease in dogs was reported. The complement system is an important effector component of humoral immunity against infectious agents. Therefore, the aim of this study was to evaluate the activation of the dog alternative complement pathway by P. brasiliensis. Initially, the ability of erythrocytes of guinea pig, rabbit, sheep, chicken and swine to activate the dog alternative pathway was evaluated. The guinea pig erythrocytes showed the greatest capacity to activate dog alternative pathway. The alternative (AH50) hemolytic activity was evaluated in 27 serum samples from healthy dogs and the mean values were 87.2 AH50/ml. No significant differences were observed in relation to sex and age. The alternative pathway activation by P. brasiliensis was higher in serum samples from adult dogs when compared to puppies and aged dogs (p ≤ 0.05). This is the first report of dog alternative complement pathway activation by P. brasiliensis and suggests that it may play a protective role in canine paracoccidioidomycosis.

To determine the association of the HLA in 50 patients with schizophrenia, schizoaffective disorder, 48 healthy controls, 41 biological relatives without psychiatric disease, and 48 biological relatives with mood disorder, the HLA genotype at the class I and class II were determined. The subjects were interviewed by structured diagnostic criteria categorized according to DSM-IV, axis I, (SCID-IV). Significant positive association was found with HLA-B.15 in patients, family with humor disorder and without mental disorder (p=0.003) and negative association of the HLA-B.35 in relatives without psychiatric disease (p=0.03). The HLA-B.15 frequency was significantly increased in a subgroup of patients with age at onset in the early 20s, lower educational achievement, occupational disability, chronically ill, more paranoid type. These findings suggest the existence of some involvement of an immunogenetic mechanism in a subgroup of schizophrenic, schizoaffective patients, and biological relatives.

An association between depression and altered immune and hormonal systems has been suggested by the results of many studies. In the present study we carried out immune and hormonal measurements in 40 non-medicated, ambulatory adult patients with depression determined by CID-10 criteria and compared with 34 healthy nondepressed subjects. The severity of the condition was determined with the Hamilton Depression Rating Scale. Of 40 depressed patients, 31 had very severe and 9 severe or moderate depression, 29 (72.5%) were females and 11 (27.5%) were males (2.6:1 ratio). The results revealed a significant reduction of albumin and elevation of alpha-1, alpha-2 and beta-globulins, and soluble IL-2 receptor in patients with depression compared to the values obtained for nondepressed subjects (P<0.05). The decrease lymphocyte proliferation in response to a mitogen was significantly lower in severely or moderately depressed patients when compared to control (P<0.05). These data confirm the immunological disturbance of acute phase proteins and cellular immune response in patients with depression. Other results may be explained by a variety of interacting factors such as number of patients, age, sex, and the nature, severity and/or duration of depression. Thus, the data obtained should be interpreted with caution and the precise clinical relevance of these findings requires further investigation.

The leukotoxin produced by Actinobacillus actinomycetemcomitans is considered the major virulence factor with potential to cause damage to the host defenses. The present work analyzed the serumal and salivary levels of antibodies against the leukotoxin produced by A. Actinomycetemcomitans, in patients with Localized Juvenile Periodontitis (LJP) and in healthy controls. Additionally, analysis of the immune complex (IC) was carried out in saliva samples. The classic ELISA method, with leukotoxin obtained through Sephadex G-200 gel filtration, and the capture ELISA method, using rabbit anti-A. Actinomycetemcomitans (leukotoxic, FDC Y4, IgG) adsorbed with a non-leukotoxic strain of A. actinomycetemcomitans, were used. The results obtained demonstrated significantly higher serumal levels of IgG in patients with LJP, when they were compared with the healthy controls, both for the classic and capture ELISA methods (p < 0.05). However, no significant differences were observed between the salivary levels of IgG, SIgA and IC in the examined individuals. These results suggest that even though A. actinomycetemcomitans presents virulence factors that affect the immune response, there is immune response to leukotoxin in LJP patients. This increase of IgG in the blood stream might contribute to host defense, limiting the lesion to the periodontal regions already colonized by A. actinomycetemcomitans.

The polymorphonuclear neutrophil (PMN) chemotaxis index and modulation of serum factors in 15 Brazilian periodontal patients (five localized juvenile and ten adult periodontitis) and ten healthy subjects were examined. Adult periodontitis patients showed a normal chemotaxis index, Localized juvenile periodontitis LJP patients showed diminished chemotaxis and serum cell-directed inhibitor activity. The results suggest that PMN abnormalities could not be caused by only the neutrophils themselves, but also by modulation of serum factors acting on this LJP disease.

Anti-human T lymphocyte serum specific to the receptor for sheep erythrocytes (E) was produced by immunizing sheep with autologous erythrocytes sensitized with solubilized receptors from human lymphocytes. The anti-soluble receptors serum (anti-Rs) inhibited E-Rosette formation, identified T lymphocytes by indirect immunofluorescence, agglutinated the formalized E-soluble receptors complexes, and inhibited the E-soluble receptors interaction. This anti-Rs serum was also submitted to the affinity chromatography by protein A sepharose, and the amounts of 0.15 to 120 micrograms of purified anti-Rs IgG were added to the lymphocyte culture. The result obtained showed an induction of proliferative response of the normal human lymphocytes in the presence of 60 and 120 micrograms of anti-Rs IgG.