Pathology and first report of natural infections of the eye trematode Philophthalmus lachrymosus Braun, 1902 (Digenea, Philophthalmidae) in a non-human mammalian host

The avian eye trematode Philophthalmus lachrymosus Braun, 1902 is for the first time referred naturally occurring in a non-human mammalian host. Previously, natural infections with P. lachrymosus and other species of Philophthalmus have been occasionally reported from man, with few data on experimental infections of non-human mammals. Results presented here are related to the report of two cases of philophthalmosis due to natural infections of wild Brazilian capybaras, Hydrochaeris hydrochaeris L., 1766 with P. lachrymosus and associated pathology. Clinical signs, gross and microscopic lesions as well as new morphometric data on the parasite are presented.

Pathology of periportal fibrosis involution in human schistosomiasis

Optical and electron microscopical evidences of focal matrix degradation were frequently seen in liver sections of periportal fibrosis caused by schistosomiasis mansoni in man. The material came from 14 wedge hepatic biopsies taken from patients with chronic advanced hepatosplenic disease and undergoing operations for the relief of portal hypertension. Besides the presence of focal areas of rarefaction, fragmentation and dispersion of collagen fibers, the enlarged portal spaces also showed hyperplasia of elastic tissue and disarray of smooth muscle fibers following destruction of portal vein branches. Eggs were scanty in the tissue sections, and matrix degradation probably represented involuting changes related to the progressive diminution of parasite-related aggression, which occurs spontaneously with age or after cure by chemotherapy. The changes indicative of matrix degradation now described are probably the basic morphological counterpart of periportal fibrosis involution currently being documented by ultrasonography in hepatosplenic patients submitted to curative chemotherapy.

FETO-PLACENTARY PATHOLOGY IN HUMAN PARVOVIRUS B19 INFECTION

In view of the scarce references concerning the histological data in congenital parvovirus human B19 infection, we intend to provide a description of the pathological features observed in six autopsies.The virus was detected by DNA hybridization (ISH-DBH),PCR and electronmicroscopy (EM) in paraffin-embedded feto-placentary tissues.These cases constitute a subset from 86 Non Immunologic Hydrops Fetalis (NIHF) cases, in which a systemic complex of inflammatory/degenerative lesions of unknown etiology was visualized by optical microscopy. In one case a syphilitic process was detected, typefying a double infection. All fetuses showed a similar pathology - hydrops, hepato-splenomegaly, lung hypoplasia and erythroblastemia, the specific histological feature being the presence of intranuclear inclusions in the erythroid progenitors, in the erythropoietic visceral tissue and in blood marrow. Complex cardiopathy allied to abnormal lung lobulation and polisplenia were observed once; in 2 cases endocardial fibroelastosis was diagnosed. The pulmonary lesions were represented by dysmaturity allied to interstitial mononuclear infiltration. The hepatic consisted of cholestasis, portal fibrosis, canalicular proliferation, hemossiderosis, focal necroses and giant cell transformation. The central nervous system lesions were predominantly anoxic although the autolysis impaired a correct diagnosis.

Pathology of complete atrioventricular block in chronic chagas' myocarditis

Sclero-atrophy, fibrosis, vascular ectasia, phlebosclerosis and mild non-specific chronic inflammatory changes were observed in variable location and proportion involving the atrioventricular conducting tissue of the heart in five human cases of chronic Chagas' myocarditis associated with complete atrioventricular block. One case presented complete destruction of the A-V conduction system. In three cases the lesions were disseminated all along the conducting tissue but did not cause anywhere a complete disruption in the continuity of the system. The distal portion of the bundle branches were the most damaged sector of the system, exceptfor the fasciculi of the posterior division of the left bundle branch which were relatively preserved. One case exhibited bilateral sclero-atrophy of the bundle branches as the main change; and another showed early and mild fibrocalcific damage of the penetrating portion of the His bundle. The A-V node appeared as the least involved part of the conducting system in the cases studied. Demonstration of the lesions in this series of cases seems important because: a) it reveals that complete atrioventriculr block in chronic Chagas' disease results from disseminated lesions and not from focal disruptive change as has been commonly observed in cases of other etiologies; b) it shows that chronic inflammation can produce at the end variable and widespread vascular, degenerative andfibrotic alterations within the conducting tissue of the heart, which may lead to its total destruction.

Biodemes and zymodemes of Trypanosoma cruzi strains: correlations with clinical data and experimental pathology

With the objective of establishing biological and biochemical characteristics of a significant number of Trypanosoma cruzi strains from different geographical areas, 138 strains isolated from naturally infected humans, triatomine or vertebrate hosts were studied; 120 were isolated from different areas of Brazil and 18 from other South and Central American countries. Inocula from triatomine or culture forms were injected into suckling Swiss mice, followed by passages into mice 10 to 12 g. Biological characters and histopathological study permitted the inclusion of the strains into three Types or biodemes: I, II, III. Isoenzymic analysis confirmed a correspondence between the biodemes and zymodemes : Type I and Z2b, Type II and Z2, Type III and Z1. Results showed the ubiquitary distribution of the several types of strains. The predominance of the same Type and zymodeme in one geographical area was confirmed : Type II strains among the human cases from eastern Bahia and east of Goiás; Type III strains from humans of north Brazil and Central America and from silvatic vectors or vertebrates from other geographical areas. The biological types of strains correlate with different histopathological lesions considering cardiac involvement and neuronal lesions. These findings suggest that the biological behavior together with isoenzymes patterns and pathological pictures in the vertebrate host can be an important tool for establishing correlations between strains behavior and clinico-pathological manifestations of Chagas' disease in different geographical areas.

Severe digestive pathology associated with chronic Chaga's disease in Ecuador: report of two cases

DNA extracted from peripheral blood of two Ecuadorian patients showing severe digestive pathology was amplified by the polymerase chain reaction using a Trypanosoma cruzi specific oligonucleotide primers derived from the primary sequence of a cDNA encoding for a 24 kDa excretory/secretory protein. The positive PCR results together with the clinical findings confirmed that both patients had a digestive pathology due to Chagas' disease. This pathology could be more frequent than previously described in the chagasic endemic regions of Andean countries.

Hepatic pathology in Capillaria hepatica infected mice

Septal fibrosis of the liver regularly develops in rats infected with Capillaria hepatica. To find out whether such fibrosis also occurs in mice, 20 animals were submitted to infection with either 100 or 300 embryonated eggs and histologically examined after several periods of time, from 30 to 110 days afterwards. Results showed that mice developed acute, severe, diffuse and focal hepatic lesions that were soon modulated to focal areas of fibrosis containing eggs and worm remnants, despite the fact that a few worms remained alive, at least up to 110 days after inoculation. Areas of perisinusoidal fibrosis appeared in the proximity and around focal parasitic lesions, but clear-cut septal fibrosis was not observed. Why septal fibrosis forms in rats, but not in mice during C. hepatica infection, only further studies can clarify. Mice seem to show better host/parasite relationship than rats in regard to C. hepatica infection.

Shifts in composition of avian communities related to temperate-grassland afforestation in southeastern South America

Afforestation of temperate grasslands with fast-growing trees for industrial pulpwood production is spreading in South America. Despite high afforestation rates resulting from governmental policies that stimulate pulpwood production in grasslands of southern Brazil and Uruguay, the impact of this activity on biodiversity remains to be properly assessed. We used an Impact-Reference study design to evaluate how grassland afforestation affects the composition of grassland bird assemblages. We sampled eucalyptus plantations and neighboring natural grasslands in southern Brazil from 2006-2009, and relied on nested sampling and analysis to separate the effects of afforestation from the natural variability of grasslands. We recorded a significant difference in composition between assemblages from grasslands and tree plantations. Species adapted to open, treeless areas tended to be negatively affected in relation to edge or forest birds in eucalyptus plantations. Afforestation is systematically replacing the bird assemblage of hilltop grasslands by a collection of common edge and forest species that occur in nearby riverine and hillside forests. Although most grassland birds negatively affected by tree plantations are common and widespread, observed and predicted afforestation rates in southeastern South America may result in regional population reductions in the near future.

The changing pattern of pathology due to Schistosoma mansoni infection

A survey of the autopsy data on hepatosplenic schistosomiasis during periods, before and after the advent of new chemotherapeutic drugs, revealed that: a) the pathological presentation was the same for the two periods; b) the number of cases in the last five years is progressively decreasing; c) hepatosplenic disease due to schistosomiasis is becoming rare in young people. These data represent a change in the pattern of pathology in schistosomiasis, probably related to new chemotherapy.

Filariopsis barretoi (travassos, 1921) (Nematoda: metastrongyloidea) lung parasite of primates from South America - taxonomy, synonyms and pathology

Nematodes and fragments of lungs from Cebus ssp., Callithrix jacchus (l.) and Saimiri sciureus (L.) were studied. The worms from Cebus and Callithrix must be called Filariopsis barretoi (Travassos, 1921). The names Filariopsis arator Chandler, 1931 and Filaroides cebi Gebauer, 1933 are synonymized to F. barretoi. The status of Filariopsis gordius (Travassos, 1921) remains uncertain. The pathology is described. The parasites are located in the pulmonary paranchyma, near the pleural surface, constituting nodules.

Prevalence of avian haematozoa in São Paulo state, Brazil

The blood parasites of 15,574 birds representing 266 species of 43 families from primarily three areas in São Paulo State, Brazil were examined for haematozoa. Only 1240 (8.0% of 121 species fo 32 families were infected with blood parasites. This prevalence was similar to that reported in a previous study. Species of Haemoproteus were the most commonly encountered haematozoans (38.9%), followed by microfilaria (30.7%), Trypanosoma (13.7%), Plasmodium (7.5%) and Leucocytozoon (0.8%). Prevalence of parasitism was significantly different between the three major areas sampled. It was shown that this was due in part to differences in the avifaunas at both the familial and species levels. Prevalence varied markedly in only one of the 10 years of the study. Monthly fluctuations in prevalence were largely due to changes in relative proportions of highlytion of both. Prevalences of both microfilaria and Trypanosoma were higher than reported for any other similar survey in the world.