Histological and immunological reaction of cattle skin to first-instar larvae of Dermatobia hominis

Six cattle that had earlier exposure to Dermatobia hominis were infested experimentally with first-instar larvae of the parasite. Skin biopsies taken at intervals were studied in wax and in plastic sections. The avidin-biotin-peroxidase method was used to detect the presence and localization of host immunoglobulins (Igs) G and M and antigens of first and second instar larvae of Dermatobia hominis. The larvae penetrated actively through the skin and migrated towards the subcutaneous tissues. The great numbers of eosinophils suggest that they are the most important cell in mediating damage to D.hominis larvae. The immunoglobulins bound only to dead or moulting larvae in which access to binding sites may have been altered. This could represent a morphological manifestation of a mechanism that protects larvae from the host immune response. Large amounts of soluble antigens detected along the fistulous tract may be important in the maintenance of this tract by disturbing the normal cicatrization process.

CELL-MEDIATED AND HUMORAL IMMUNE-RESPONSES IN IMMUNIZED AND OR DERMATOBIA-HOMINIS INFESTED RABBITS

The cell-mediated and humoral immune response of rabbits to antigens from larvae of Dermatobia hominis were analyzed by leucocyte migration inhibition factor assay (MIF), immunodiffusion (ID) and passive hemagglutination (PH) test in rabbits immunized with D. hominis extract, in rabbits immunized and infested with the parasite and rabbits infested with D. hominis. Twenty rabbits were divided into five groups: Group 1, rabbits immunized with a crude antigen extract, evaluated for 40 weeks at 4 week intervals; Group 2, rabbits immunized and infested with newly hatched larvae at 14 weeks post immunization (PI) and evaluated as Group 1; Group 3, rabbits immunized, evaluated for 28 weeks at 2 week intervals; Group 4, rabbits immunized and infested at 4 weeks PI and evaluated as Group 3; Group 5, rabbits infested and evaluated for 24 weeks at 2 week intervals. Different patterns of reactivity were observed in the infested and immunized animals: immunized rabbits developed antibodies and cellular immune responses earlier and at higher levels during immunization than the infested rabbits; the infestation at 14 weeks PI, when the cell-mediated and humoral immune response began to decrease, or at 4 weeks PI when these parameters were at higher levels, elicited an anamnestic response. After the spontaneous elimination of larvae by the host, from the 4th week PI onwards, high titers of antibodies and migration inhibition indices were maintained for a long period. These results suggest that the onset of cellular and humoral immune responses after immunization may be important as a biological control of myiasis and contribute to better understanding of the immune defense mechanism of the host against D. hominis.

SPINDLE MEMBRANES DURING SPERMATOGENESIS IN DERMATOBIA-HOMINIS (DIPTERA, CUTEREBRIDAE)

During the mitotic and meiotic division in Dermatobia hominis spermatogenesis, the nuclear envelope is fragmented and membranes appear around the spindle. The membranes surrounding the mitotic spindle are formed by two layers of cisterns. The membranes of the meiotic spindle consist in at least 3 or 4 layers of long smooth cisterns which isolate the spindle from the remaining cytoplasm. The presence of this kind of membranes during meiosis seems to be usual in insect male germ cell.

Rabbit antibody responses to experimental infestation with Dermatobia hominis.

The three larval stages of Dermatobia hominis (Linnaeus) have been evaluated for their immunogenicity by ELISA and immunodiffusion (ID) using sera from experimentally infested rabbits. During a primary infestation, first instar D. hominis were found to cause most reaction and allowed the earliest diagnosis by ELISA. An inhibition of the antibody response against second and third instars was observed. The inhibition disappeared after departure of the larvae from the host. In experimentally immunized hosts the antibody response, following challenge, was highest against second and third instar antigens. Antibody remained elevated during the infestation but fell immediately after the larvae had left the host.

Cytoplasmic bridges, intercellular junctions, and individualization of germ cells during spermatogenesis in Dermatobia hominis (Diptera: Cuterebridae)

During mitotic and meiotic divisions in Dermatobia hominis spermatogenesis, the germ cells stay interlinked by cytoplasm, bridges as a result of incomplete cytokinesis. By the end of each division, cytoplasmic bridges flow to the center of the cyst, forming a complex, called the fusoma. During meiotic prophase I, spermatocytes I present desmosome-like junctions and meiotic cytoplasmic bridges. At the beginning of spermiogenesis, the fusoma moves to the future caudal end of the cyst, and at this time the early spermatids are linked by desmosome-like junctions. Throughout spermiogensis, new and sometimes broad cytoplasmic bridges are formed among spermatids at times making them share cytoplasm. In this case the individualization of cells is assured by the presence of smooth cisternae that outline then structures The more differentiated spermatids have in addition to narrow cytoplasmic bridges, plasmic membranes junctions. By the end of spermiogenesis the excess cytoplasmic mass is eliminated leading to spermatid individualization. Desmosome-like junctions of spermatocytes I and early spermatids appear during the fusoma readjustment and segregations; on the other hand, plasmic membrane junctions appear in differentiating spermatids and are eliminated along with the cytoplasmic excess. These circumstances suggest that belt desmosome-like and plasmic membrane junctions are involved in the maintenance of the relative positions of male germ cells in D. hominis while they are inside the cysts. © 1996 Wiley-Liss, Inc.

Análise bioquímica dos produtos de excreção/secreção de larvas de Dermatobia hominis

Pós-graduação em Medicina Veterinária - FMVZ

Diagnóstico laboratorial de blastocistose humana - ocorrência de Blastocystis hominis (BRUMPT,1912) em habitantes da região de Araraquara-SP

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Associação entre presença de Mycoplasma hominis e Ureaplasma urealyticum e níveis de citocinas pró e antiinflamatórias no líquido amniótico de gestação de termo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Perfil de virulência e resistência aos antimicrobianos em Staphylococcus haemolyticus, S. warneri, S. lugdunensis e S. hominis

Estudar o perfil patogênico e de resistência aos antimicrobianos em amostras de Staphylococcus haemolyticus, Staphylococcus warneri, Staphylococcus lugdunensis e Staphylococcus hominis. Foram estudadas 65 amostras isoladas de pacientes do Hospital das Clínicas da FMB, Botucatu, sendo 23 S. haemolyticus, 23 S. hominis, 10 S. warneri e 9 S. lugdunensis. Foram pesquisados por PCR os genes responsáveis pela produção de biofilme (icaA, icaC, icaD), genes de enterotoxinas (sea, seb, sec, sed), Toxina 1 da Síndrome do Choque Tóxico (tst) e resistência à oxacilina (mecA). Das 65 amostras estudadas, 83% apresentaram ao menos um dos genes das toxinas pesquisadas, 87,7% um dos genes ica e 63,1% o gene mecA. O SCCmec foi tipado por PCR-Multiplex, sendo o tipo I o mais prevalente (34,1%). A heterorresistência à vancomicina foi pesquisada através da triagem em ágar BHI com 4 μg ml-1, encontrada em 36,9% das amostras, e com 6 μg ml-1 de vancomicina, encontrada em 15,4%. Todas as espécies estudadas foram altamente toxigênicas. A presença do SCCmec I apresentou relação com a heterorresistência à vancomicina. Ainda, S. hominis e S. haemolyticus se revelaram mais virulentos e resistentes, levando em conta os fatores de virulência, resistência à oxacilina e heterorresistência à vancomicina. A evidência e a necessidade de maior preocupação com as espécies S. hominis e S. haemolyticus ficou clara, o que ainda não havia sido relatado, bem como a relação entre a presença de SCCmec I e heterorresistência à vancomicina

Correlação entre presença de Mycoplasma hominis e Ureaplasma urealyticum e níveis IL-6 e IL-10 no líquido amniótico de gestantes com trabalho de parto prematuro

O trabalho de parto prematuro (TPP) é uma intercorrência obstétrica com etiologia multifatorial, que tem como principal complicação a prematuridade. A infecção da cavidade amniótica (CA) é um fator associado ao TPP e, nos últimos anos, inúmeros trabalhos têm demonstrado a presença de diferentes espécies bacterianas no líquido amniótico (LA) de pacientes em TPP. Dentre essas, destacam-se duas espécies de micoplasmas genitais, Mycoplasma hominis e Ureaplasma urealyticum, que embora sejam freqüentemente detectadas no LA ainda são pouco estudadas quanto à sua relação com essa complicação obstétrica. Avaliar a infecção na cavidade amniótica por M. hominis e U. urealyticum bem como determinar os níveis de IL-6 e IL-10 no líquido amniótico de gestantes com trabalho de parto prematuro. Foi realizado estudo prospectivo com 20 gestantes em TPP, atendidas no Serviço de Obstetrícia do Hospital das Clínicas da Faculdade de Medicina de Botucatu, UNESP. O grupo controle foi constituído de 20 gestantes com indicação para amniocentese transabdominal para avaliação da maturidade fetal. Foram obtidas amostras do líquido amniótico e das membranas corioamnióticas de todas as pacientes incluídas no estudo. A pesquisa de M.hominis e U.urealyticum no LA foi realizada empregando-se a técnica de reação em cadeia da polimerase (PCR) e os níveis de IL-6 e IL-10 quantificados por ensaio imunoenzimático (ELISA). Os dados obtidos referentes às características maternas, infecção da cavidade amniótica e concentração de citocinas no LA foram submetidos ao teste z de proporção e ao teste de Mann-Whitney e o nível de significância adotado foi de 5%. A incidência de TPP no período do estudo foi de 5,8%. No grupo TPP, a pesquisa de invasão microbiana da CA foi positiva para... (Resumo completo, clicar acesso eletrônico abaixo)

Centriole behaviour during meiosis of male germ cells of Dermatobia hominis (Diptera:Cuterebridae)

During the meiotic division of Dermatobia hominis spermatogenesis, the centrioles duplicate only in prophase I, giving rise to short cilia which are exposed on the cellular surface. In metaphase I they are internalized and distributed to the daughter cells. Consequently, the secondary spermatocytes have two centrioles which repeat the cycle of cilia externalization followed by internalization. The spermatids receive only one centriole, which changes into a basal body and originates a flagellum. This centriole behaviour seems to be a general feature in insect male germ cell meiosis.

Dermatobia hominis: potencial risk of resistance to macrocyclic lactones

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Intestinal parasitic infections in HIV/AIDS patients: epidemiological, nutritional and immunological aspects

This study applied a socioeconomic questionnaire designed to evaluate the frequency of intestinal parasites and characterize epidemiological, nutritional, and immunological variables in 105 HIV/AIDS patients - with and without parasitic infections, attending the Day Hospital in Botucatu, UNESP, from 2007 to 2008. Body mass index was calculated and the following tests performed: parasitological stool examinations; eosinophil, IgE, CD4(+) T and CD8(+) T lymphocyte cell counts; albumin test; viral load measure; and TNF-alpha, IFN-gamma, IL-2, IL-5 and IL-10 cytokine levels. Results were positive for parasitic intestinal infections in 12.4% of individuals. Most patients had good socioeconomic conditions with basic sanitation, urban dwellings, treated water supply and sewage, good nutritional and immunological status and were undergoing HAART. Parasites were found at the following frequencies: Entamoeba - five patients (38.5%), Giardia lamblia-four (30.7%), Blastocystis hominis-three (23.0%), Endolimax nana-two (15.4%), and Ascaris lumbricoides - one (7.7%). There were no significant differences between the two groups for eosinophils, albumin, IgE, CD4(+) T and CD8(+) T lymphocytes, INF-gamma, IL-2, or IL-10. Most patients also showed undetectable viral load levels. Significant differences were found for TNF-alpha and IL-5. These results show the importance of new studies on immunodeficient individuals to increase understanding of such variables.

Amniotic Fluid Interleukin-1 Beta and Interleukin-6, but not Interleukin-8 Correlate with Microbial Invasion of the Amniotic Cavity in Preterm Labor

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