Antigenicity of Primary Endodontic Infection against Macrophages by the Levels of PGE(2) Production

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A critical analysis of isolation of Paracoccidioides brasiliensis from soil

The present review is a critical analysis of positive and negative reports of the isolation of Paracoccidioides brasiliensis from soil. The strains isolated from soil or soil-contaminated material (dogfood, penguin feces) by Batista et al. in Recife, Brazil, Negroni in the Argentinian Chaco, Albornoz in rural Venezuela, Silva-Vergara et al, in Ibia, Brazil, Ferreira et al, in Uberlandia, Brazil, and Gezuele et al. at the Uruguayan base in the Antarctic region, presented mycological characteristics consistent with P. brasiliensis. In most of these studies, morphological characterization was complemented with an evaluation of virulence and antigenicity, and biochemical or molecular analysis. These isolations, therefore, can be considered true, supporting the concept of soil as an important element in the ecology of the pathogen. The large number of negative reports in attempts involving soil samples and the low repeatability of isolation of the fungus from the same area indicate that the specific conditions supporting growth of the pathogen in soil have not been fully clarified.

A comparative study of the immunoantigenicity of eight Paracoccidioides brasiliensis isolates

Para se detectar diferenças imuno-antigênicas entre 8 amostras de P. brasiliensis isoladas de diferentes áreas endêmicas (Botucatu: Pb 1, 2 e 3; São Paulo: Pb: 18, 192 e 265; Venezuela: Pb 9 e 73), esutdaram-se: 1. A reatividade antigênica de cada amostra nas reações de imunofluorescência indireta (II) e de imunodifusão dupla em gel de agar (ID) contra painel de 20 soros controles positivos para paracoccidioidomicose; 2. A capacidade de induzir resposta imune humoral (medida por imunodifusão) e celular (medida pelo teste de coxim plantar) em camundongos imunizados com an-tígenos de cada amostra. Observamos: 1. As amostras Pb 265 e Pb 9 mostraram-se mais reativas na II; 2. Os antígenos das amostras Pb 192 e Pb 73 foram significativamente mais reativas na ID; 3. Estes dados demonstram diferenças de antigenicidade entre estas amostras; 4. A amostra Pb 18 mostrou baixo poder indutor de resposta imune celular e alta capacidade de indução de resposta imune humoral em camundongos imunizados, revelando dissociação de sua imunogenicidade. Estas diferenças podem indicar a existência de cepas distintas do fungo ou refletir modificações do parasita no hospedeiro ou du rante seu cultivo.

Antigenic Activity of Bacterial Endodontic Contents from Primary Root Canal Infection with Periapical Lesions against Macrophage in the Release of Interleukin-1 beta and Tumor Necrosis Factor alpha

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Frontal sinus obliteration with heterogeneous corticocancellous bone versus spontaneous osteoneogenesis in monkeys (Cebus apella): Histologic analysis

Purpose: In this study, we evaluated the results of spontaneous osteoneogenesis of the frontal sinus with autogenous bone plug versus obliteration with heterogeneous (human) bone in monkeys (Cebus apella).Materials and Methods: Eight young adult male C apella monkeys underwent an ostectomy of the anterior wall of the frontal sinus, removal of the sinus mucosa, and inner decortication of the bony walls and then were divided into 2 groups of 4 each, as follows. Group I monkeys underwent obliteration of the nasofrontal ducts with a free segment of frontallis muscle and corticocancellous heterogeneous bone, followed by full obliteration of the sinus with corticocancellous heterogeneous bone (Dayton Regional Tissue Bank, Dayton, OH). Group II monkeys underwent obliteration of the nasofrontal ducts with a frontal muscle segment and tibial autogenous bone plug, without full obliteration of the frontal sinus. In all animals, the sinus anterior wall was repositioned and fixed with 1.0 plate and screws. The monkeys were killed after 180 days, and routine laboratory procedures were followed for hematoxylin-eosin staining and histologic evaluation of the specimens.Results: the 2 studied techniques were both effective in obliterating the frontal sinus with newly formed bone. The nasofrontal ducts were obliterated by new bone formation or fibrous tissue (1 animal only).Conclusions: Both methods used for frontal sinus obliteration were effective; the heterogeneous bone (human bone) was well tolerated and presented low antigenicity. The nasofrontal duct obliteration with autogenous muscle associated with autogenous tibial bone (group II) or with heterogeneous bone (group I) was effective, isolating the frontal sinus from the nasal cavity. The spontaneous obliteration resulted, in the period analyzed, in earlier bone maturation compared with the obliteration by heterogeneous bone. (C) 2003 American Association of Oral and Maxillofacial Surgeons.

Genetic variability of porcine parvovirus isolates revealed by analysis of partial sequences of the structural coding gene VP2

The 3'-terminal 853 nt (and the putative 283 aa) sequence of the VP2-encoding gene from 29 field strains of porcine parvovirus (PPV) were determined and compared both to each other and with other published sequences. Sequences were examined using maximum-parsimony and statistical analyses for nucleotide diversity and sequence variability. Among the nucleotide sequences of the PPV field strains, 26 polymorphic sites were encountered; 22 polymorphic sites were detected in the putative amino acid sequence. Mapping polymorphic sites of protein data onto the three-dimensional (3D) structure of PPV VP2 revealed that almost all substitutions were located on the external surface of the viral capsid. Mapping amino acid substitutions to the alignment between PPV VP2 sequences and the 3D structure of canine parvovirus (CPV) capsid, many PPV substitutions were observed to map to regions of recognized antigenicity and/or to contain phenotypically important residues for CPV and other parvoviruses. In spite of the high sequence similarity, genetic analysis has shown the existence of at least two virus lineages among the samples. In conclusion, these results highlight the need for close surveillance on PPV genetic drift, with an assessment of its potential ability to modify the antigenic make-up of the virus.

Isolation of fungi from nature in the region of Botucatu, state of São Paulo, Brazil, an endemic area of paracoccidioidomycosis

In an attempt to isolate Paracoccidioides brasiliensis from nature 887 samples of soil from Botucatu, SP, Brazil, were collected cultured in brain heart infusion agar supplemented with dextrose, in potato dextrose agar and in yeast extract starch dextrose agar, all with antibiotics, at 25º and 37ºC. Five thermo-dependent dimorphic fungi morphologically resembling P. brasiliensis were isolated; two from armadillo holes; further studies of the biology, antigenicity and genetic features of the five dimorphic fungi are necessary to clarify their taxonomy and their possible relation to P. brasiliensis. In addition, 98 dematiaceous fungi and 581 different species of Aspergillus spp. were also isolated. Our findings emphasize that armadillos and their environment are associated with thermo-dimorphic fungi and confirm the ubiquity of pathogenic dematiaceous fungi and Aspergillus spp.

Genetic and phylogenetic analysis of glycoprotein of rabies virus isolated from several species in Brazil

Genetic and phylogenetic analyses of the region containing the glycoprotein (G) gene, which is related to pathogenicity and antigenicity, and the G-L intergenic region were carried out in 14 Brazilian rabies virus isolates. The isolates were classified as dog-related rabies virus (DRRV) or vampire bat-related rabies virus (VRRV), by nucleoprotein (N) analysis. The nucleotide and amino acid (AA) homologies of the area containing the G protein gene and G-L intergenic region were generally lower than those of the ectodomain. In both regions, nucleotide and deduced AA homologies were lower among VRRVs than among DRRVs. There were AA differences between DRRV and VRRV at 3 antigenic sites and epitopes (IIa, WB+ and III), suggesting that DRRV and VRRV can be distinguished by differences of antigenicity. In a comparison of phylogenetic trees between the ectodomain and the area containing the G protein gene and G-L intergenic region, the branching patterns of the chiropteran and carnivoran rabies virus groups differed, whereas there were clear similarities in patterns within the DRRV and VRRV groups. Additionally, the VRRV isolates were more closely related to chiropteran strains isolated from Latin America than to Brazilian DRRV. These results indicate that Brazilian rabies virus isolates can be classified as DRRV or VRRV by analysis of the G gene and the G-L intergenic region, as well as by N gene analysis.

ISOLATION OF BABESIA-BIGEMINA AND BABESIA-BOVIS MEROZOITES BY AMMONIUM-CHLORIDE LYSIS OF INFECTED ERYTHROCYTES

1. We describe the isolation of viable merozoites from erythrocytes infected with Babesia bovis or Babesia bigemina organisms by ammonium chloride lysis.2. Parasite morphology was examined by both light and transmission electron microscopy. Erythrocyte-free parasites maintain their viability and infectivity, retain their antigenicity and are suitable for use in the indirect fluorescent antibody assay.

Epstein-Barr virus (EBV) nuclear antigen (EBNA)-4 mutation in EBV-associated malignancies in three different populations

Different ethnic groups with a high human leukocyte antigen (HLA)-A11 prevalence have been shown to experience a high rate of Epstein-Barr virus (EBV) infection, EBV-associated malignancies, and Epstein-Barr nuclear antigen (EBNA)-4 mutations. The epitopes 393-408 and 416-424 of EBNA-4 are major antigenic epitopes that elicit an HLA-A11 cytotoxic T lymphocyte (CTL) response to EBV infection. Mutations selectively involving one or more nucleotide residues in these epitopes affect the antigenicity of EBNA-4, because the mutant EBV strains are not recognized by the HLA-A11-restricted CTLs. To investigate these mutations in common EBV-associated malignancies occurring in different populations, we studied the mutation rate of epitopes 393-408 and 416-424 of EBNA-4 in 25 cases of EBV-associated Hodgkin's disease (HD), nine cases of AIDS-related non-Hodgkin's lymphoma, and 37 cases of EBV-associated gastric carcinoma (GC) from the United States, Brazil, and Japan. We found one or more mutations in these two epitopes in 50% (6/12) of United States HD, 15% (2/13) of Brazilian HD, 50% (6/12) United States GC and 28% (7/25) Japanese GC, and 22% (2/9) of United States AIDS-lymphoma. Similar mutations were found in 30% (3/10) of United States reactive, 0% (0/6) of Brazilian reactive, and 25% (2/8) Japanese reactive tissues. The most frequent amino acid substitutions were virtually identical to those seen in previously reported isolates from EBV-associated nasopharyngeal carcinomas and Burkitt's lymphomas occurring in high prevalence HLA-A11 regions. However, only 2/28 (7%) mutations occurred in HLA-A11-positive patients. Our studies suggest that: 1) EBNA-4 mutations are a common phenomenon in EBV-associated HD, GC, and AIDS-lymphoma; 2) the mutation rate does not vary in these geographic areas and ethnic groups; 3) EBNA-4 mutations in EBV-associated United States and Brazilian HD, United States and Japanese GC, and United States AIDS lymphomas are not related to patients' HLA-A11 status.

Histopathological evaluation in experimental envenomation of dogs with Crotalus durissus terrificus Venom

The present work evaluated histopathological aspects in experimental envenomation of dogs with Crotalus durissus terrificus venom. Twenty-eight mixed breed adult dogs were divided into three groups of seven animals each: Group I only venom; Group II - venom + 50ml antiophidic serum + fluid therapy; Group III venom + 50ml antiophidic serum + fluid therapy + urine alkalization. Lyophilized venom of Crotalus durissus terrificus was reconstituted in saline solution and inoculated subcutaneously at the dose of 1mg/kg body weight. Three animals of each group were subjected to euthanasia, and their muscular tissue, brain, spleen, kidneys, heart, lungs, stomach, small and large intestines, and popliteal lymph node fragments were collected for histopathological evaluation. There was myonecrosis in the inoculated limb, renal tubular degeneration, lymphoid hyperplasia of spleen, and unspecific reactive hepatitis. These results show the antigenicity and action of the venom on the immune system.

Aspectos imunogeneticos na pesquisa da etiologia da catarata senil

The immunogenetic study of senile cataract showed that the association with the HLA antigens and Ia antigens suggests an influence of the antigenicity for cataractogenesis, but not a peculiar specificity. However, the investigation of the immunoglobulins in lens suggest that the lens pathology may be produced by antibodies reacting with the lens capsule and consequently interfering with the lens epithelial metabolism, and contributes to the complex mechanism of cataract formation.

Allogeneic transplants of rib cartilage preserved in 98% glycerol or 70% alcohol into the malar process of rats: a comparative histological study.

A comparative study was made of two methods of cartilage preservation, 98% glycerol and 70% alcohol. Rib cartilage was treated by either of these methods and transplanted into the malar process of rats. Cartilage grafts preserved by both methods were equally well tolerated. Resorption and bone substitution were similar in both groups after 120 days, although resorption was greater for the alcohol-preserved cartilage up until day 30. The possible reduction in antigenicity by the 98% glycerol did not produce any difference of behavior from the cartilage preserved in 70% alcohol.

Detection of enterotoxin and toxic shock syndrome toxin 1 genes in Staphylococcus, with emphasis on coagulase-negative staphylococci

The detection of staphylococcal enterotoxins is decisive for the confirmation of an outbreak and for the determination of the enterotoxigenicity of strains. Since the recognition of their antigenicity, a large number of serological methods for the detection of enterotoxins in food and culture media have been proposed. Since immunological methods require detectable amounts of toxin, molecular biology techniques represent important tools in the microbiology laboratory. In the present study, polymerase chain reaction (PCR) was used to identify genes responsible for the production of enterotoxins and toxic shock syndrome toxin 1 (TSST-1) in S. aureus and coagulase-negative staphylococci (CNS) isolated from patients and the results were compared with those obtained by the reverse passive latex agglutination (RPLA) assay. PCR detection of toxin genes revealed a higher percentage of toxigenic S. aureus strains (46.7%) than the RPLA method (38.3%). Analysis of the toxigenic profile of CNS strains showed that 26.7% of the isolates produced some type of toxin, and one or more toxin-specific genes were detected in 40% of the isolates. These results suggests the need for further studies in order to better characterize the pathogenic potential of CNS and indicate that attention should be paid to the toxigenic capacity of this group of microorganisms.

Tissue engineering: Using collagen type i matrix for bone healing of bone defects

Among the many tissues in the human body, bone has been considered as a powerful marker for regeneration and its formation serves as a prototype model for tissue engineering based on morphogenesis. Therefore, collagen type I is one of the most useful biomaterials used in tissue engineering as extracellular matrix components capable to promote bone healing. The literature reveals excellent biocompatibility and safety due to its biological characteristics, such as biodegradability and weak antigenicity, making collagen type I the primary resource in medical applications. Thus, it was also used for tissue engineering including skin replacement, bone substitutes, and artificial blood vessels and valves. The authors describe the treatment of an abscessed apical periodontal cyst and show good outcomes of bone healing, using tissue engineering, as collagen type I matrix. © 2013 by Mutaz B. Habal, MD.