Liver morphology with emphasis on bile ducts changes and survival analysis in mice submitted to multiple Schistosoma mansoni infections and chemotherapy

In an attempt to be as close as possible to the infected and treated patients of the endemic areas of schistosomiasis (S. mansoni) and in order to achieve a long period of follow-up, mice were repeatedly infected with a low number of cercariae. Survival data and histological variables such as schistosomal granuloma, portal changes, hepatocellular necrosis, hepatocellular regeneration, schistosomotic pigment, periductal fibrosis and chiefly bile ducts changes were analysed in the infected treated and non treated mice. Oxamniquine chemotherapy in repeatedly infected mice prolonged survival significantly when compared to non-treated animals (chi-square 9.24, p = 0.0024), thus confirming previous results with a similar experimental model but with a shorter term follow-up. Furthermore, mortality decreased rapidly after treatment suggesting an abrupt reduction in the severity of hepatic lesions. A morphological and immunohistochemical study of the liver was carried out. Portal fibrosis, with a pattern resembling human Symmers fibrosis was present at a late phase in the infected animals. Bile duct lesions were quite close to those described in human Mansonian schistosomiasis. Schistosomal antigen was observed in one isolated altered bile duct cell. The pathogenesis of the bile duct changes and its relation to the parasite infection and/or their antigens are discussed.

Occurrence of enteroparasites in day care centers in Botucatu (São Paulo State, Brazil) with emphasis on Cryptosporidium sp., Giardia duodenalis and Enterobius vermicularis

The occurrence of the enteroparasites was verified in 279 children (0 to 6 years) of four municipal day cares of Botucatu/SP. Three samples of each child's feces were collected and processed by the methods of Hoffman-Pons-Janner, Faust and Ritchie and subsequent coloration of the fecal smear by the methods of Auramina-O and Ziehl-Neelsen modified for diagnosis of Cryptosporidium sp. and Graham method for diagnosis of Enterobius vermicularis. Of the analyzed children we verified a prevalence of intestinal parasitism in 53.40%, and the most frequent parasite was Giardia duodenalis (26.88%). Significant association was verified among enteroparasitosis, family income, maternal education and age; the lowest enteroparasite frequency occurred in children of families with larger income and higher education. It was observed that G. duodenalis is more prevalent in children from 0 to 4 years and E. vermicularis is more frequent in children between three and four years old. The high enteroparasite prevalence in day cares suggests complex structure in its epidemiology, where factors beyond sanitation should be considered.

Ecological aspects of mosquitoes (Diptera: Culicidae) in the gallery forest of Brasilia National Park, Brazil, with an emphasis on potential vectors of yellow fever

Introduction We analyzed the vertical and monthly distributions of culicid species in the gallery forest of Brasília National Park, with an emphasis on the potential vectors of yellow fever (YF). Methods Between September 2010 and August 2011, mosquitoes were captured on the ground and in the canopy of the forest for five consecutive days per month, from nine to 15 hours. The mosquitoes were examined to verify natural infection with flaviviruses by isolation in Aedes albopictus Skuse, 1864 cells followed by indirect immunofluorescence. Results We identified 2,677 culicids distributed in 29 species. Most of the mosquitoes were captured at ground level (69%) during the rainy season (86%). The most abundant species were Sabethes (Sabethes) albiprivus Theobald, 1903; Limatus durhamii Theobald, 1901; Haemagogus (Conopostegus) leucocelaenus Dyar & Shannon, 1924; Haemagogus (Haemagogus) janthinomys Dyar, 1921; Aedes (Ochlerotatus) scapularis Rondani, 1848; Psorophora (Janthinosoma) ferox Von Humboldt, 1819; and Aedes (Ochlerotatus) serratus Theobald, 1901. Limatus durhamii, Limatus durhamii, Psorophora ferox, Aedes scapularis and Aedes serratus showed significant differences (p<0.05) in their habitat use. Limatus durhamii was found more often in the canopy, unlike the other species. During the rainy season, the most abundant species were Sa. albiprivus, Haemagogus leucocelaenus and Limatus durhamii. During the dry season, the potential YF vectors exhibited a very low frequency and abundance, except Aedes scapularis and Aedes serratus. No flavivirus was detected in the 2,677 examined mosquitoes. Conclusions We recommend continued and systematic entomological monitoring in areas vulnerable to the transmission of YF in the Federal District of Brazil.

Ostracoda (Crustacea) from the Archipelago of São Pedro and São Paulo, Equatorial Atlantic, with emphasis on a new Hemicytheridae genus

The present study is a further contribution to the systematic knowledge of the shallow water marine ostracodes from the Brazilian oceanic islands. A total of 14 species belonging to 10 genera and eight families is herein identified. One new genus and species are described and illustrated: Berguecythere insularis gen. nov., sp. nov. In addition to this new taxon, the abundant species Loxocorniculum tricornatum Krutak, 1971, widely distributed in recent sediments in the Gulf of Mexico, Caribbean, north and northeast of Brazil and the Rocas Atoll, along with the cosmopolitan tropical ostracode Triebelina sertata Triebel, 1948, were also identified at specific level. The remaining 11 species were left at the genus level, and should provide new species. Ecological, zoo- and paleozoogeographical aspects were also briefly discussed.

Nematode parasites of Brazilian psittacid birds, with emphasis on the genus Pelecitus railliet & Henry, 1910

In the present paper, some species of nematodes from Brazilian parrots are studied: Aproctapyrrhurae. Ascaridia hermaphrodita, A. sergiomeirai, Pelecitus circularis and P. helicinus. Single female specimens of Pelecitus sp. and Thelazia sp. are presented. The male of P. circularis is fully illustrated, for the first time, since 1884. Ascaridia sergiomeirai is also restudied 59 years after proposition. New host records are estabilished. Remarks on other species of nematodes occuring in psittacid birds are included.

Current advances on the study of snail-snail interactions, with special emphasis on competition process

Field work research on population dynamic of snails from the regions of Belo Horizonte and Lagoa Santa give much information about interactions among two or more species of mollusks: Pomacea haustrum, Biomphalaria glabrata, B. tenagophila, B. straminea and Melanoides tuberculata. Data ranging from two years to several decades ago suggest that the Pampulha reservoir is like a cemetery of B. glabrata and B. straminea, species that coexist for more than 14 years in a small part of a stream, whereas only B. glabrata lives in all the streams of the basin. In the last ten to twenty years B. tenagophila has coexisted with P. haustrum and M. tuberculata in the Serra Verde ponds and in the Pampulha dam. However these species have not settled in any of the brooks, except temporarily. The data suggest that the kind of biotope and the habitat conditions are decisive factors for the permanence of each species in its preferencial biotope. B. glabrata, natural from streams and riverheads, quickly disappears from the reservoirs and ponds where it coexists with other species for a short time, independently of the competitive process. Competition needs to be better studied, since in Central America and Caribean islands this kind of study has favored the biological control of planorbid species.

Studies on the biology of schistosomiasis with emphasis on the Senegal river basin

The construction of the Diama dam on the Senegal river, the Manantali dam on the Bafing river, Mali and the ensuing ecological changes have led to a massive outbreak of Schistosoma mansoni in Northern Senegal, associated with high intensity of infections, due to intense transmission, and the creation of new foci of S. haematobium. Data on the vectorial capacity of Biomphalaria pfeifferi from Ndombo, near Richard Toll, Senegal are presented with sympatric and allopatric (Cameroon) S. mansoni. Comparisons are made on infectivity, cercarial production, chronobiology of cercarial emergence and longevity of infected snails. Recent data on the intermediate host specificity of different isolates of S. haematobium from the Lower and Middle Valley of the Senegal river basin (SRB) demonstrate the existence of at least two strains of S. haematobium. The role of Bulinus truncatus in the transmission of S. haematobium in the Lower and Middle Valleys of the SRB is reviewed. Both S. haematobium and S. mansoni are transmitted in the same foci in some areas of the SRB.

The Triatomines of Northern Peru, with Emphasis on the Ecology and Infection by Trypanosomes of Rhodnius ecuadoriensis (Triatominae)

Information on the distribution and synanthropic behaviour of triatomines is essential for Chagas disease vector control. This work summarises such information from northern Peru, and presents new data on Rhodnius ecuadoriensis - an important local vector infesting 10-35% of dwellings in some zones. Three species are strongly synanthropic and may be suitable targets for chemical control of domestic/peridomestic bug populations. Panstrongylus herreri, the main domestic vector in the area, is probably present in sylvatic ecotopes in the Marañón river system. R. ecuadoriensis and Triatoma dimidiata seem exclusively domestic; biogeographical and ecological data suggest they might have spread in association with humans in northern Peru. Confirmation of this hypothesis would result in a local eradication strategy being recommended. Presence of trypanosome natural infection was assessed in 257 R. ecuadoriensis; Trypanosoma rangeli was detected in 4% of bugs. Six further triatomine species are potential disease vectors in the region (T. carrioni, P. chinai, P. rufotuberculatus, P. geniculatus, R. pictipes, and R. robustus), whilst Eratyrus mucronatus, E. cuspidatus, Cavernicola pilosa, Hermanlentia matsunoi, and Belminus peruvianus have little or no epidemiological significance. A strong community-based entomological surveillance system and collaboration with Ecuadorian public health authorities and researchers are recommended.

Human bartonellosis: seroepidemiological and clinical features with an emphasis on data from Brazil - A review

Bartonellae are fastidious Gram-negative bacteria that are widespread in nature with several animal reservoirs (mainly cats, dogs, and rodents) and insect vectors (mainly fleas, sandflies, and human lice). Thirteen species or subspecies of Bartonella have been recognized as agents causing human disease, including B. bacilliformis, B. quintana, B. vinsonii berkhoffii, B. henselae, B. elizabethae, B. grahamii, B. washoensis, B. koehlerae, B. rocha-limaea, and B. tamiae. The clinical spectrum of infection includes lymphadenopathy, fever of unknown origin, endocarditis, neurological and ophthalmological syndromes, Carrion's disease, and others. This review provides updated information on clinical manifestations and seroepidemiological studies with an emphasis on data available from Brazil.

Recent advances in the study of avian malaria: an overview with an emphasis on the distribution of Plasmodium spp in Brazil

Avian malaria parasites (Plasmodium) have a worldwide distribution except for Antarctica. They are transmitted exclusively by mosquito vectors (Diptera: Culicidae) and are of particular interest to health care research due to their phylogenetic relationship with human plasmodia and their ability to cause avian malaria, which is frequently lethal in non-adapted avian hosts. However, different features of avian Plasmodium spp, including their taxonomy and aspects of their life-history traits, need to be examined in more detail. Over the last 10 years, ecologists, evolutionary biologists and wildlife researchers have recognized the importance of studying avian malaria parasites and other related haemosporidians, which are the largest group of the order Haemosporida by number of species. These studies have included understanding the ecological, behavioral and evolutionary aspects that arise in this wildlife host-parasite system. Molecular tools have provided new and exiting opportunities for such research. This review discusses several emerging topics related to the current research of avian Plasmodium spp and some related avian haemosporidians. We also summarize some important discoveries in this field and emphasize the value of using both polymerase chain reaction-based and microscopy-based methods in parallel for wildlife studies. We will focus on the genus Plasmodium, with an emphasis on the distribution and pathogenicity of these parasites in wild birds in Brazil.

The phlebotomine fauna (Diptera: Psychodidae) of Guaraí, state of Tocantins, with an emphasis on the putative vectors of American cutaneous leishmaniasis in rural settlement and periurban areas

Phlebotomine sandflies were captured in rural settlement and periurban areas of the municipality of Guaraí in the state of Tocantins (TO), an endemic area of American cutaneous leishmaniasis (ACL). Forty-three phlebotomine species were identified, nine of which have already been recognised as ACL vectors. Eleven species were recorded for the first time in TO. Nyssomyia whitmani was the most abundant species, followed by Evandromyia bourrouli, Nyssomyia antunesi and Psychodopygus complexus. The Shannon-Wiener diversity index and the evenness index were higher in the rural settlement area than in the periurban area. The evaluation of different ecotopes within the rural area showed the highest frequencies of Ev. bourrouli and Ny. antunesi in chicken coops, whereas Ny. whitmani predominated in this ecotope in the periurban area. In the rural settlement area, Ev. bourrouli was the most frequently captured species in automatic light traps and Ps. complexus was the most prevalent in Shannon trap captures. The rural settlement environment exhibited greater phlebotomine biodiversity than the periurban area. Ps. complexus and Psychodopygus ayrozai naturally infected with Leishmania (Viannia) braziliensis were identified. The data identified Ny. whitmani as a potential ACL vector in the periurban area, whereas Ps. complexus was more prevalent in the rural environment associated with settlements.

A comparative study of the effect of multiple immersions on Aedini (Diptera: Culicidae) mosquito eggs with emphasis on sylvan vectors of yellow fever virus

The effect of multiple immersions on Haemagogus janthinomys , Haemagogus leucocelaenus , Aedes albopictus and Ochlerotatus terrens eggs was studied. Eggs were collected in April, June, October and December of 2011 in Minas Gerais, Brazil. Most of the Aedes and Ochlerotatus eggs hatched upon the first immersion, while Haemagogus eggs showed a varied instalment hatching response. The number of immersions required for hatching increased for eggs collected closer to the dry winter season.

Analysis of experiments in square lattice with emphasis on variance components. i. Individual analysis

This paper focused on four alternatives of analysis of experiments in square lattice as far as the estimation of variance components and some genetic parameters are concerned: 1) intra-block analysis with adjusted treatment and blocks within unadjusted repetitions; 2) lattice analysis as complete randomized blocks; 3) intrablock analysis with unadjusted treatment and blocks within adjusted repetitions; 4) lattice analysis as complete randomized blocks, by utilizing the adjusted means of treatments, obtained from the analysis with recovery of interblock information, having as mean square of the error the mean effective variance of this same analysis with recovery of inter-block information. For the four alternatives of analysis, the estimators and estimates were obtained for the variance components and heritability coefficients. The classification of material was also studied. The present study suggests that for each experiment and depending of the objectives of the analysis, one should observe which alternative of analysis is preferable, mainly in cases where a negative estimate is obtained for the variance component due to effects of blocks within adjusted repetitions.

Laryngeal schwannoma: a case report with emphasis on sonographic findings

Schwannomas are benign nerve sheath tumors composed of Schwann cells, which normally produce the insulating myelin sheath covering peripheral, cranial and autonomic nerves. Twenty-five to forty-five percent of all schwannomas occur in the head and neck region, but location of such tumors in the larynx is rarely observed. The present report is aimed at describing a clinical case of laryngeal schwannoma, with emphasis on sonographic findings.