Autoradiographic analysis of Schistosoma mansoni migration in the NZ rabbit

The migration of larval Schistosoma mansoni was tracked by means of autoradiographic analysis in naive rabbits percutaneously exposed to L-(**75 Se) selenomethionine-labeled cercariae on serial intervals of 1, 2, 4, 6, 8, 10, 15, 20, 25, 30, 40 and 50 days post-infection. Autoradiographic foci were detected from the 1st day in the skin, up to the 15th day in the liver. Adult and mature worms were recovered either paired or not 60 days after infection, by perfusion of hepatic and mesenteric veins. Morphometric analysis under optical microscopy, showed that worms were within regular dimention limits as compared to adult worms harboured by other host species. These observations extend previous informations on the S. mansoni-rabbit association and clearly demonstrate the post-liver phase of S.mansoni life-cycle in this host.

Susceptibility of laboratory-reared female Lutzomyia longipalpis (Lutz & Neiva, 1912) to infection by different species and strains of Leishmania Ross, 1903

A study was undertaken to compare the susceptibility of laboratory-reared female Lutzomyia longipalpis to infection by different species or strains of New World Leishmania. The sand flies proved to be highly susceptible to infection by a strain of Le. guyanensis, with flagellates developing in all (18/18) of the specimens examined. A lower infection rate of 37 per cents (10/27) was recorded in flies exposed to infection by a strain of Le. amazonensis. Flagellates developed in 13 per cents (6/46) of the sand flies that glood fed on dogs in the earlly stage of experimental infection with an old laboratory strain of Le. chagasi. In contrast, promastigotes did not develop in sand flies that blood fed on dogs with naturally acquired Le. chagasi. The naturally infected dogas were in an advanced stage of disease. Flagellates developed in 9// (3/32) of the sand flies that blood fed on lesions of hamsters infected with a strain of Le. braziliensis and in 9 per cents (3/34) of those that fed on hamsters with lesions due to a parasite fo the mexicana complex (strain MHOM/BR/73/BH121). Sand flies did not develop flagellate infections after blood feeding on hamsters bearing lesions induced by strain MHOM/BR/71/BR49. Factors influencing the susceptibility of Lu. longipalpis to infection by New World species of Leishmania are discussed.

Methodology in structural determination and synthesis of insect pheromone

By means of ethereal washing of insect pheromone glands of female moths, GC-MS detection along with microchemical reactions and electroantennogram (EAG) survey, six economically important insect species were targeted for pheromone identification. The discovery of a natural pheromone inhibitor, chemo-selectivity and species isolation by pheromone will be described. The modified triple bond migration and triethylamine liganded vinyl cuprate were applied for achiral pheromone synthesis in double bond formation. Some optically active pheromones and their stereoisomers were synthesized through chiral pool or asymmetric synthesis. Some examples of chiral recognition of insects towards their chiral pheromones will be discussed. A CaH2 and silica gel catalyzed Sharpless Expoxidation Reaction was found in shortening the reaction time.

Structure of the salivary glands of the unfed female tick Amblyomma cajennense (Fabricius) (Acarina: Ixodidae)

Acini in in the salivary glands of female tick specimens of Amblyomma ajennense unfed at both postnymphal and adult phases, were studied. The salivary glands are consisted by three acini, one agranular and two granular. The agranular acini are directly attached to the anterior portion of the main salivary duct, consisting of cells without valve. A relatively large, clear, central cell occupies most of the alveolar midsection. The central cell is in contact with the acini lumen. Granular acini consist of approximately seven to fourteen cells (type II acini) or seven to sixteen (type III acini). The type II acini have three types of granular cells ("a", "b" and "c") and valve; the type III acini have another three types of granular cells ("d", "e" and "f") also presenting a valve.

Expanded description of the female of Lernaeenicus longiventris Wilson, 1917, (Copepoda, Siphonostomatoida, Pennellidae) based on specimens from Mugil platanus Günter, 1880 (Perciformes, Mugilidae) of the state of Rio de Janeiro, Brazil

The description of Lernaeenicus longiventris is expanded and revised, based on specimens collected from the skin and fins of mullets, Mugil platanus Gunther, 1880, from 21 locations in coastal waters of the state of Rio de Janeiro, Brazil.

Prevalence of human papillomavirus DNA in female cervical lesions from Rio de Janeiro, Brazil

A hundred-sixty paraffin-embedded specimens from female cervical lesions were examined for human papillomavirus (HPV) types 6, 11, 16 and 18 infections by non-isotopic in situ hybridization. The data were compared with histologic diagnosis. Eighty-eight (55) biopsies contained HPV DNA sequences. In low grade cervical intraepithelial neoplasias (CIN I), HPV infection was detected in 78.7 of the cases, the benign HPV 6 was the most prevalent type. HPV DNA was detected in 58 of CIN II and CIN III cases and in 41.8 of squamous cell carcinomas (SCC). Histologically normal women presented 20 of HPV infection. Oncogenic HPV was found in 10 of these cases, what may indicate a higher risk of developing CINs and cancer. Twenty-five percent of the infected tissues contained mixed infections. HPV 16 was the most common type infecting the cervix and its prevalence raised significantly with the severity of the lesions, pointing its role in cancer pathogenesis. White women presented twice the cervical lesions of mulatto and African origin women, although HPV infection rates were nearly the same for the three groups (approximately 50). Our results showed that HPV typing by in situ hybridization is a useful tool for distinguishing between low and high risk cervical lesions. Further studies are required to elucidate risk factors associated with HPV infection and progression to malignancy in Brazilian population.

Molecular aspects of Schistosoma mansoni female maturation

Incubation of total protein extracts of Schistosoma mansoni with 3H 17-beta-estradiol and 20-hydroxyecdysone, revealed steroid binding proteins in both, male and female worms. The interaction of nuclear proteins with restriction fragments of the gender and stage-specific gene F-10 was investigated using the "Band-Shift" technique. Distinct male and female nuclear proteins bound to the fragments of this gene. Among the nuclear proteins, only those rich in cysteine residues bound to DNA. In vitro incubation of live worms with the estrogen antagonist Tamoxifen, altered the pattern of the DNA binding proteins, producing in females, a band profile similar to that obtained with male worm protein extracts. When Tamoxifen was injected into schistosome infected mice, the eggs produced by females presented an abnormal morphology, compatible with non-viable eggs. These results suggest that the regulation of transcription of the F-10 gene might involve steroid receptors.

Schistosoma mansoni: control of female fertility by the male

We have established an in vitro culture system for adult schistosomes that allows monitoring gene expression for up to more than ten days. Comparing female worms that are paired with those that have been separated, we find distinct differences, clearly documenting an influence of the male in female gene expression. In perfect coincidence with classical observations that were based on histological techniques, we find that the male particularly regulates gene expression in those tissues that are characterized by cell proliferation, e.g. the vitellaria. From these results, we hypothesize that the key target for the inductive signal that is transferred from the male to the female during pairing is the activation of a growth factor that stimulates mitotic proliferation.

Diagnostic Importance of Female External Genital Structure of Phlebotomine Sand Flies (Diptera:Psychodidae) as Observed by Scanning Electron Microscopy

Morphological description of sand flies has remained a neglected area. The different organs used in taxonomy have not yet been described adequately with the scanning electron microscopy (SEM). We have examined the external genital structures of females of three Old World phlebotomine sand flies under SEM and recorded the morphological variations of the organs. We have found the female external genital structures of the three species varied considerably in morphology. The importance of the female external genital structures in sand fly identification is indicated

Morphology and Histology of the Female Reproductive System of Abedus ovatus Stal (Belostomatidae: Hemiptera: Insecta)

In Abedus ovatus Stal, the female reproductive system consists of a pair of ovaries leading to oviduct and opens out by genital aperture. Each ovary is composed of five telotrophic ovarioles, with four different regions, terminal filament, germarium, vitellarium and pedicel. Germarium and vitellarium are the germ tubes in which the development of oocyte occurs. In the germarium, the differentiation of trophocytes into young oocytes was observed in three zones, ZI, ZII and ZIII. Further development of oocytes in the vitellarium could be divided into seven stages, STI STVII. The developed eggs are lodged in the pedicel

A role for lymphocytes and cytokines on the eosinophil migration induced by LPS

In the present work we review the existing evidence for a LPS-induced cytokine-mediated eosinophil accumulation in a model of acute inflammation. Intrathoracic administration of LPS into rodents (mice, rats or guinea pigs) induces a significant increase in the number of eosinophils recovered from the pleural fluid 24 hr later. This phenomenon is preceded by a neutrophil influx and accompanied by lymphocyte and monocyte accumulation. The eosinophil accumulation induced by LPS is not affected by inhibitors of cyclo or lipoxygenase nor by PAF antagonists but can be blocked by dexamethasone or the protein synthesis inhibitor cycloheximide. Transfer of cell-free pleural wash from LPS injected rats (LPS-PW) to naive recipient animals induces a selective eosinophil accumulation within 24 hr. The eosinophilotactic activity present on the LPS-PW has a molecular weight ranging between 10 and 50 kDa and its effect is abolished by trypsin digestion of the pleural wash indicating the proteic nature of this activity. The production of the eosinophilotactic activity depends on the interaction between macrophages and T-lymphocytes and its effect can not be blocked by anti-IL-5 monoclonal antibodies. Accumulated evidence suggest that the eosinophil accumulation induced by LPS is a consequence of a eosinophilotactic cytokine produced through macrophage and T-cell interactions in the site of a LPS-induced inflammatory reaction.

The Effects of a DNA Virus Infection on the Reproductive Potential of Female Tsetse Flies, Glossina morsitans centralis and Glossina morsitans morsitans (Diptera: Glossinidae)

Reproductive anomalies associated with the tsetse DNA virus infection in the female tsetse hosts, Glossina morsitans centralis Machado and Glossina morsitans morsitans Westwood, inoculated with the virus during the 3rd instar larval stage were studied and the data compared to those obtained from the control females injected with sterile physiological saline. Virus infected flies had significantly longer first and second pregnancy cycles (P<0.0001) and produced pupae that were of significantly less weight in milligrams (P<0.0001) compared to controls. Transmission of the virus to progeny was not absolute and only 21% of G. m. centralis and 48% of G. m. morsitans first progeny flies from infected females developed salivary gland hypertrophy as a result of transmission from mother to progeny. The virus infected females produced significantly fewere pupae compared to the controls during the experimental period (P<0.00001).

Risk Factors for Human T Cell Lymphotropic Virus Type I among Injecting Drug Users in Northeast Brazil: Possibly Greater Efficiency of Male to Female Transmission

It was observed in the city of Salvador, State of Bahia, the highest seroprevalence of human T cell lymphotropic virus type 1 (HTLV-I) infection in Brazil as demonstrated by national wide blood bank surveys. In this paper, we report results of an investigation of drug use and sexual behavior associated with HTLV-I infection among male and female injecting drug users (IDUs) in Salvador. A cross sectional study was conducted in the Historical District of Salvador from 1994-1996 (Projeto Brasil-Salvador) and 216 asymptomatic IDUs were selected using the snowball contact technique. Blood samples were collected for serological assays. Sera were screened for human immunodeficiency virus (HIV-1/2) and HTLV-I/II antibodies by ELISA and confirmed by Western blot. The overall prevalence of HTLV-I/II was 35.2% (76/216). The seroprevalence of HTLV-I, HTLV-II and HIV-1 was for males 22%, 11.3% and 44.1% and for females 46.2%, 10.3% and 74.4% respectively. HTLV-I was identified in 72.4% of HTLV positive IDUs. Variables which were significantly associated with HTLV-I infection among males included needle sharing practices, duration of injecting drug use, HIV-1 seropositivity and syphilis. Among women, duration of injecting drug use and syphilis were strongly associated with HTLV-I infection. Multivariate analysis did not change the direction of these associations. Sexual intercourse might play a more important role in HTLV-I infection among women than in men.