Microglia and neurons in the hippocampus of migratory sandpipers

The semipalmated sandpiper Calidris pusilla and the spotted sandpiper Actitis macularia are long- and short-distance migrants, respectively. C. pusilla breeds in the sub-arctic and mid-arctic tundra of Canada and Alaska and winters on the north and east coasts of South America. A. macularia breeds in a broad distribution across most of North America from the treeline to the southern United States. It winters in the southern United States, and Central and South America. The autumn migration route of C. pusilla includes a non-stop flight over the Atlantic Ocean, whereas autumn route of A. macularia is largely over land. Because of this difference in their migratory paths and the visuo-spatial recognition tasks involved, we hypothesized that hippocampal volume and neuronal and glial numbers would differ between these two species. A. macularia did not differ from C. pusilla in the total number of hippocampal neurons, but the species had a larger hippocampal formation and more hippocampal microglia. It remains to be investigated whether these differences indicate interspecies differences or neural specializations associated with different strategies of orientation and navigation.

EXPERIMENTAL INFECTION WITH Toxocara cati IN PIGS: MIGRATORY PATTERN AND PATHOLOGICAL RESPONSE IN EARLY PHASE

Experimental inoculations of approximately 100,000 infective Toxocara cati larval eggs were done in twelve pigs. The T. cati eggs used for inoculation were collected from cat's feces. Another group of three pigs served as an uninfected control. Groups of infected pigs were euthanized at seven, 14, 21, and 28 days post-inoculation (dpi). Tissue samples were taken for digestion and histopathology changes in early phase. The number of larvae recovered from the lungs peaked at seven and 14 dpi and were also present at 21, and 28 dpi. Larvae of T. cati were present in the lymph nodes of the small and large intestine at seven, 14, and 28 dpi and at seven, 14, 21, and 28 dpi respectively. In other studied tissues, no larvae or less than one larva per gram was detected. The pathological response observed in the liver and lungs at seven and 14 dpi, showed white spots on the liver surface and areas of consolidation were observed in the lungs. The lungs showed an inflammatory reaction with larvae in center at 28 dpi. In the liver we observed periportal and perilobular hepatitis. The lymph nodes of the intestines displayed eosinophil lymphadenitis with reactive centers containing parasitic forms in some of them. The granulomatous reaction was not observed in any tissues. The role of the other examined tissues had less significance. The relevance of this parasite as an etiological agent that leads to disease in paratenic hosts is evident.

Necrolytic migratory erythema associated with glucagonoma syndrome: a case report

Necrolytic migratory erythema is a rare skin condition that consists of migrating areas of erythema with blisters that heal with hyperpigmentation. It usually occurs in patients with an alpha islet cell tumor of the pancreas-or glucagonoma-and when associated with glucose intolerance, anemia, hyperglucagonemia, and weight loss defines the glucagonoma syndrome. We describe a 52-year-old female patient with necrolytic migratory erythema associated with glucagonoma syndrome who had metastatic disease at presentation and passed away one week after her admission. The autopsy showed a tumor in the body of the pancreas, which was diagnosed as a neuroendocrine tumor and confirmed by immunohistochemistry. The diagnosis of necrolytic migratory erythema is a matter of great importance, since it might be an auxiliary tool for the early detection of glucagonoma.

Penetration Sites and Migratory Routes of Angiostrongylus costaricensis in the Experimental Intermediate Host (Sarasinula marginata)

The intermediate hosts of Angiostrongylus costaricensis are terrestrian molluscs, mostly of the family Veronicellidae. The present work aimed at clarifying more accurately the sites of penetration and the migratory routes of A. costaricensis in the tissue slugs and at verifying the pattern of the perilarval reaction at different times of infection. Slugs were individually infected with 5,000 L1, and killed from 30 min to 30 days after infection. From 30 min up to 2 hr after infection, L1 were found within the lumen of different segments of the digestive tube having their number diminished in more advanced times after exposition until complete disappearance. After 30 min of exposition, percutaneous infection occurred, simultaneously to oral infection. Perilarval reaction was observed from 2 hr of infection around larvae in fibromuscular layer, appearing later (after 6 hr) around larvae located in the viscera. A pre-granulomatous reaction was characterized by gradative concentration of amebocytes around larvae, evolving two well-organized granulomas. In this work we confirmed the simultaneous occurrence of oral and percutaneous infections. Perilarval reaction, when very well developed, defined typical granulomatous structure, including epithelioid cell transformation. The infection also caused a systemic mobilization of amebocytes and provoked amebocyte-endothelium interactions.

Helminth parasites in six species of shorebirds (Charadrii) from the Coast of Belize

Thirteen species of helminth parasites were recovered from six species of charadriid shorebirds (Aves: Charadriiformes) from Belize: the ruddy turnstone, Arenaria interpres, the snowy plover, Charadrius alexandrinus, the semipalmated plover, C. semipalmatus, the killdeer, C. vociferus, the white-rumped sandpiper, Calidris fuscicollis, and the black-bellied plover, Pluvialis squatarola. Cestode species were predominant (N = 8), followed by trematode species (N = 3) and acanthocephala (N = 2). The trematode, Paramaritremopsis solielangi infected four of the six species of hosts. The cestodes, Nadejdolepis litoralis and N. paranitidulans infected three and two host species respectively. Helminth parasite species were contagious (clumped) and not evenly distributed among hosts. Twelve of the 13 species were generalists. The one specialist Microphallus kinsellae was recovered from one C. fuscicollis. Three of the four types of feeding guilds were present and in approximately the same number. All but M. kinsellae have been reported from other species of hosts, mostly from Eurasia and North America.

Angiostrongylus costaricensis: complete redescription of the migratory pathways based on experimental Sigmodon hispidus infection

Angiostrongylus costaricensis lives in the cecal and mesenteric arteries of its vertebrate hosts, and causes an inflammatory disease in humans. To investigate unknown aspects of the abdominal angiostrogyliasis pathogenesis, infected Sigmodon hispidus were sequentially studied in different times of infection. The study revealed that L3 goes alternatively through two migratory courses during its development into an adult worm: lymphatic/venous-arterial and venous portal pathways. The former is considered the principal one, because it is used by most of the larvae. Like other metastrongylides, A. costaricensis passes over the pulmonary circulation to migrate from the lymphatic system to the arterial circulation, where they circulate during some days before reaching their definitive habitat. The oviposition by mature females began on 15th day. Eggs and L1 were detected mainly in the intestine and stomach, surrounded by inflammatory reaction constituted by macrophages, monocytes, and eosinophils. They were also spread to the lungs, mesenteric lymph nodes, pancreas, spleen, and kidneys. The larvae (L1) exhibited the centripetal capacity to invade the lymphatic and venous vessels of the intestine and mesentery. Adult worms that developed in the venous intrahepatic pathway migrated downstream to reach the mesenteric veins and laid eggs that embolized in the portal hepatic vessels.

Inquérito sorológico da prevalência de infecção chagásica no Brasil, 1975/1980

A nationwide seroepidemiologic survey of human T. cruzi infection was carried out in Brazil from 1975 to 1980 as a joint programme of the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and the Superintendência de Campanhas (SUGAM), Ministry of Health, of Brazil. Due to the marked heterogeneity of urban populations as result of wide migratory movements in the country and since triatomine transmission of the disease occurs mostly in rural areas, the survey was limited to rural populations. The survey was based on a large cluster sampling of complete households, from randomly selected localities comprised of 10 to 500 houses, or up to 200 houses in the Amazon region. Random selection of localities and houses was permitted by a detailed mapping of every locality in the country, as performed and continuously adjusted, by SUCAM. In the selected houses duplicate samples on filter paper were collected from every resistent 1 year or older. Samples were tested in one of 14 laboratories scattered in the country by the indirect anti-IgG immunofluorescence test, with reagents produced and standardized by a central laboratory located at the Instituto de Medicina Tropical de São Paulo. A continuous quality control was performed at this laboratory, which tested duplicates of 10% to 15% of all samples examined by the collaborating laboratories. Data regarding number of sera collected, patients'age, sex, place of residence, place of birth and test result were computerized at the Department of Preventive Medicine, Medical School, University of São Paulo, São Paulo, Brazil. Serologic prevalence indices were estimated for each Municipality and mapped according to States and Territories in Brazil. Since data were already available for the State of São Paulo and the Federal District, these unities were not included in the survey.

ASSESSMENT OF IVERMECTIN THERAPEUTIC EFFICACY ON THIRD-STAGE LARVAE OF Lagochilascaris minor IN MICE EXPERIMENTALLY INFECTED

In this study we evaluated the potential action of ivermectin on third-stage larvae, both at migratory and encysted phases, in mouse tissues after experimental infection with Lagochilascaris minor. Study groups I and II consisted of 120 mice that were orally administered 1,000 parasite eggs. In order to assess ivermectin action upon migratory larvae, group I (60 mice) was equally split in three subgroups, namely I-A, I-B, and I-C. On the 7th day after inoculation (DAI), each animal from the subgroup I-A was treated with 200 µg/Kg ivermectin while subgroup I-B was given 1,000 µg/Kg, both groups received a single subcutaneous dose. To assess the drug action on encysted larvae, group II was equally split in three subgroups, namely II-A, II-B, II-C. On the 45th DAI each animal was treated with ivermectin at 200 µg/Kg (subgroup II-A) and 1,000 µg/Kg (group II-B) with a single subcutaneous dose. Untreated animals of subgroups I-C and II-C were used as controls. On the 60th DAI all animals were submitted to larva search. At a dose of 1,000 µg/Kg the drug had 99.5% effectiveness on third-stage migratory larvae (subgroup I-B). Ivermectin efficacy was lower than 5% on third-stage encysted larvae for both doses as well as for migratory larvae treated with 200µg/Kg.

Preliminary investigation of Culicidae species in South Pantanal, Brazil and their potential importance in arbovirus transmission

In view of the high circulation of migratory birds and the environmental and climatic conditions which favor the proliferation of arthropods, the Brazilian Pantanal is susceptible to circulation of arboviruses. However, the amount of data concerning arbovirus vectors in this area is scarce; therefore the aim of this study was to conduct a preliminary investigation of Culicidae species in the Nhecolândia Sub-region of South Pantanal, Brazil and their potential importance in the arbovirus transmission. A total of 3684 specimens of mosquitoes were captured, 1689 of which caught in the rainy season of 2007, were divided into 78 pools and submitted to viral isolation, Semi-Nested RT-PCR and Nested RT-PCR, with a view to identifying the most important arboviruses in Brazil. Simultaneously, 70 specimens of ticks found blood-feeding on horses were also submitted to the same virological assays. No virus was isolated and viral nucleic-acid detection by RT-PCR was also negative. Nevertheless, a total of 22 Culicidae species were identified, ten of which had previously been reported as vectors of important arboviruses. The diversity of species found blood-feeding on human and horse hosts together with the arboviruses circulation previously reported suggest that the Nhecolândia Sub-region of South Pantanal is an important area for arbovirus surveillance in Brazil.

Malaria in the State of Amazonas: a typical Brazilian tropical disease influenced by waves of economic development

In Brazil, more than 99% of malaria cases are reported in the Amazon, and the State of Amazonas accounts for 40% of this total. However, the accumulated experience and challenges in controlling malaria in this region in recent decades have not been reported. Throughout the first economic cycle during the rubber boom (1879 to 1912), malaria was recorded in the entire state, with the highest incidence in the villages near the Madeira River in the Southern part of the State of Amazonas. In the 1970s, during the second economic development cycle, the economy turned to the industrial sector and demanded a large labor force, resulting in a large migratory influx to the capital Manaus. Over time, a gradual increase in malaria transmission was observed in peri-urban areas. In the 1990s, the stimulation of agroforestry, particularly fish farming, led to the formation of permanent Anopheline breeding sites and increased malaria in settlements. The estimation of environmental impacts and the planning of measures to mitigate them, as seen in the construction of the Coari-Manaus gas pipeline, proved effective. Considering the changes occurred since the Amsterdam Conference in 1992, disease control has been based on early diagnosis and treatment, but the development of parasites that are resistant to major antimalarial drugs in Brazilian Amazon has posed a new challenge. Despite the decreased lethality and the gradual decrease in the number of malaria cases, disease elimination, which should be associated with government programs for economic development in the region, continues to be a challenge.

Rheumatic fever: a multicenter study in the State of São Paulo

Rheumatic fever is still the most commonly seen rheumatic disease in Brazilian pediatric rheumatology clinics. It remains a significant health problem since subsequent cardiac sequelae represent one of the most important causes of chronic heart disease in children. We reviewed the clinical manifestations of rheumatic fever in 786 patients, followed at seven pediatric rheumatology clinics in the state of São Paulo, Brazil. All patients were diagnosed according to revised Jones' criteria. Regarding major criteria, 396 (50.4%) children exhibited carditis, 453 (57.6%) polyarthritis, 274 (34.8%) chorea, 13 (1.6%) erythema marginatum, and 12 (1.5%) subcutaneous nodules. Valvular lesions documented by echocardiography in the absence of accompanying auscultatory findings were found in 144 (18.3%) patients. Migratory polyarthritis was observed in 290 (64.0%) patients with articular involvement. Documented previous streptococcal infection assessed by serum antistreptolysin (ASO) titers occurred in 531 (67.5%) patients. Even though prophylaxis with benzathine penicillin was recommended to all patients, recurrent attacks were observed in 147 (18.7%). We emphasize the high frequency of chorea, silent carditis and recurrences in our series as well as the variable clinical presentation of arthritis in rheumatic fever. Multicenter studies should be encouraged to improve our understanding of the clinical features of rheumatic diseases in children and adolescents.

A description of mercury in fishes from the Madeira River Basin, Amazon, Brazil

Over the last 20 years several projects carried on the Madeira River basin in the Amazon produced a great amount data on total Hg concentration in different fish species. In this paper we discuss temporal trends in Hg contamination and its relation to body weight in some of those fishes, showing that even within similar groups, such as carnivorous and non-migratory fish, the interspecies variability in Hg accumulation is considerable.

Philophthalmus gralli (Digenea: Philophthalmidae) parasite of Anas bahamensis and Amazonetta brasiliensis, from Lagoons of Maricá county, Rio de Janeiro, Brazil

Forty ducks, 18 Anas bahamensis (white-cheecked pintail) and 22 Amaxonetta brasiliensis (Brazilian duck) from Maricá and Guarapina lagoons, Maricá, RJ, Brazil, were examined. The prevalence of Philophthalmus gralli in A. bahamensis was 22.2% ans in A. brasiliensis was 27.27%. This is the first record of P. gralli in the Neotropical region, and A. bahamensis and A. brasiliensis are new host records for P. gralli.

Systemic modulation of peripheral eosinophilia (air pouch model) in Schistosoma mansoni infection

Schistosoma mansoni infection induces in their hosts a marked and sustained eosinophilia, which is influenced or modulated by complex mechanisms, that vary according to the phase of infection. To address this phenomenon, we used the air pouch (AP) model in control and infected Swiss webster mice, analyzing the cellular, tissue response and local expression of adhesion molecules [CD18 (beta 2-chain), CD44, ICAM-1 (CD54), L-selectin (CD62L), CD49d (alpha 4-chain), LFA1 (CD11a)]. Infected animals were studied at 3 (pre-oviposition phase), 7 (acute phase), and 14 (chronic phase) weeks after infection (5-6 mice/period of infection). Normal mice were age-matched. Results showed that after egg stimulation, compared with matched controls, the infected mice, at each point of infection, showed a lower eosinophil response in the acute (7 weeks) and chronic phase (14 weeks) of infection. However, when the infected mice were in pre-oviposition phase (3 weeks) their eosinophil response surpassed the control ones. In the AP wall of infected mice, a significant decrease in the expression of ICAM-1 and CD44 in fibroblastic-like cells and a reduction in the number of CD18 and CD11a in migratory cells were observed. The other adhesion molecules were negative or weakly expressed. The results indicated that in the air pouch model, in S. mansoni-infected mice: (1) eosinophil response is strikingly down-regulated, during the acute ovular phase; (2) in the pre-oviposition phase, in contrast, it occurs an up-regulatory modulation of eosinophil response, in which the mechanisms are completely unknown; (3) in the chronic phase of the infection, the down modulation of eosinophil response is less pronounced; 4) Down-regulation of adhesion molecules, specially of ICAM-1 appear to be associated with the lower eosinophil response.

Prevalence of Helicobacter pylori Infection in a Rural Area of the State of Mato Grosso, Brazil

The prevalence of Helicobacter pylori infection was evaluated by ELISA in 40 children and teenagers and in 164 adults from a rural area of the State of Mato Grosso, Brazil. Antibodies to H. pylori were detected in the serum of 31 (77.5%) children and teenagers and in 139 (84.7%) adults. The prevalence of infection increased with age (c2 for trend, p < 0.01) even though no variations occurred in the region in the present century in terms of living conditions or sanitation, economical development and migratory influx supporting the hypothesis that the infection is also acquired during later life in developing countries. An inverse correlation was observed between the prevalence of infection and annual family income (c2 for trend, p < 0.013). There was no correlation between type of system for sewage disposal and prevalence of infection (p = 0.8). In conclusion, the prevalence of H. pylori infection in Nossa Senhora do Livramento, a rural area from Brazil, is very high and similar to that observed in other developing countries. Furthermore, the increase in the prevalence of infection with age observed in this population seems to be due to both, cohort effect and acquisition of the infection during later life