A retrospective study of 40 victims of Crotalus snake bites: analysis of the hepatic necrosis observed in one patient

Forty patients with a diagnosis of snake bite were studied at the Infectious and Parasitic Disease Service of the Faculty of Medicine of Botucatu. Thirty were males and 10 females, ranging in age from 16 to 70 years. All were farm laborers and 35 of them were bitten in the lower limbs. Two of the 9 patients seen more than 6 hours after the bite died. The low mortality rate (5%) observed could be explained by the early care provided, by the use of appropriate doses of anti-crotalus serum, parenteral hydration, urine alkalinization with sodium bicarbonate and induction of osmotic diuresis with a mannitol solution. Anatomopathological examination of one of the patients who died revealed extensive hepatic necrosis. The authors discuss the possibility of the effect of a factor of snake venom in the genesis of hepatic necrosis and in the increased transaminase levels.

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.

Pathogenesis of hepatic septal fibrosis associated with Capillaria hepatica infection of rats

Septal fibrosis is a common form of hepatic fibrosis, but its etiology and pathogenesis are poorly understood. Rats infected with the helminth Capillaria hepatica constitute a good experimental model of such fibrosis. To investigate the pathogenetic contribution of the several parasitic factors involved, the following procedures were performed in rats: a) regarding the role of eggs, these were isolated and injected either into the peritoneal cavity or directly into the liver parenchyma; b) for worms alone, 15-day-old infection was treated with mebendazole, killing the parasites before oviposition started; c) for both eggs and worms, rats at the 30th day of infection were treated with either mebendazole or ivermectin. Eggs only originated focal fibrosis from cicatricial granulomas, but no septal fibrosis. Worms alone induced a mild degree of perifocal septal fibrosis. Systematized septal fibrosis of the liver, similar to that observed in the infected controls, occurred only in the rats treated with mebendazole or ivermectin, with dead worms and immature eggs in their livers. Thus, future search for fibrogenic factors associated with C. hepatica infection in rats should consider lesions with both eggs and worms.

Fulminant hepatic failure in children and adolescents in Northern Brazil

The histological findings of fulminant hepatic failure were correlated to the demographic, clinical, biochemical and virological features in children and adolescents, native to the Amazonas State in Northern Brazil. 96.2% had evidence of infection by primary hepatotrophic viruses. Histological analysis revealed three distinct patterns of fulminant hepatic failure.

Capillaria hepatica-induced hepatic fibrosis in rats: paradoxical effect of repeated infections

Multiple exposures to parasitic agents are considered an important factor in the genesis of the most severe forms of the diseases they cause. Capillaria hepatica-induced septal fibrosis of the liver in rats usually runs without signs of portal hypertension or hepatic failure. After determining the hepatic profile of 15 animals during the course of a single infection, we submitted 20 rats to multiple Capillaria hepatica infections to determine whether repeated exposures would augment fibrosis production, transforming septal hepatic fibrosis into a true cirrhosis. Ten single-infection rats served as controls. A total of 5 exposures, with 45-day intervals, were made. Histological changes were followed by means of surgical liver biopsies, collected prior to infection and to each re-infection. Functional changes were minimal and transient. Although a slight recrudescence of fibrosis was observed after the first two re-infections and when the single-infected control group was re-infected at the end of the experiment, subsequent re-infections failed to increase the amount of fibrosis. On the contrary, there occurred quantitative and qualitative evidence of collagen degradation and suppression of parasite development. These paradoxical results are in keeping with the hypothesis that a complex immunological modulation participates in the mechanism of hepatic fibrosis induced by Capillaria hepatica infection in rats.

Infecções do trato respiratório inferior pelo vírus sincicial respiratório em crianças hospitalizadas menores de um ano de idade

Analisou-se características clínicas e evolutivas em crianças menores de um ano internadas com infecção do trato respiratório inferior por vírus sincicial respiratório (VSR). Feito estudo transversal com 89 lactentes hospitalizados durante as épocas de maior incidência do VSR, em 1997 e 1998, na cidade do Rio de Janeiro. Foram pesquisados antígenos virais, nas secreções de nasofaringe, com anticorpos monoclonais anti-VSR, antiinfluenza A e B e antiparainfluenza tipo 3, por ensaio de imunofluorescência indireta. Formaram-se três grupos: bronquiolite ou bronquite sibilante (n=44), pneumonia (n=26) e bronquiolite e pneumonia (n=19). Houve positividade para o VSR em 42 (47,1%) pacientes. Em 1997 a média de dias de oxigenoterapia foi de 5,2 e em 1998, de 2,5 dias (p> 0,05). Não houve diferença de apresentação clínica entre os lactentes que apresentaram positividade para o VSR e aqueles cujo resultado foi negativo. A sensibilidade e especificidade da sibilância em relação ao isolamento de VSR foram 85% e 65%, respectivamente. O VSR foi o principal causador de infeções do trato respiratório inferior em lactentes que necessitaram de hospitalização.

Role of partial hepatectomy on Capillaria hepatica-induced hepatic fibrosis in rats

It is known that hepatic fibrosis may regress following partial hepatectomy, since the hepatic parenchyma regenerates very rapidly, but not the excess of fibrous tissue. The present study evaluated this hypothesis by observing the behavior of systematized septal fibrosis induced by either 30 or 90-day-old Capillaria hepatica infection, in rats subjected to partial hepatectomy. The results revealed that the morphology of the fibrosis was unaffected, but its relative quantity within the microscope field appeared significantly decreased, as a consequence of the increased liver tissue mass following regeneration.

Evaluation of the histopathological hepatic lesions and opportunistic agents in Brazilian HIV patients

INTRODUCTION: to evaluated the type histopathological hepatic lesions and opportunistic agents in Brazilian HIV-infected patients. METHODS: we examined 52 percutaneous liver biopsies of 50 HIV-infected patients who had at least two of the following conditions: fever of unknown origin, unexplained severe emaciation, hepatomegaly or abnormal liver chemistry. The specimens were cultured for mycobacteria and fungi and stained by standard procedures. RESULTS: reactive patterns, granulomatous hepatitis and chronic active hepatitis were verified in 28 (54%), 11 (21%) and 8 (15%) of the patients respectively. Opportunistic infections were diagnosed in 18 (36%) patients: mycobacteria in 12 (24%), Cryptococcus neoformans in 5 (10%) patients and mycobacteria and yeast was isolated from the same liver fragment in one patient. CONCLUSIONS: mycobacteriosis was the most common opportunistic infection and liver tissue culture is an important method to detect opportunistic agents, even in the absence of histological lesions.

Dynamics of Capillaria-hepatica-induced hepatic septal fibrosis in rats

INTRODUCTION: The pathogenesis of septal hepatic fibrosis, induced in rats by Capillaria hepatica infection, was studied with the aid of a large collection of stored paraffin blocks, representative of the different evolutive phases of fibrosis which appeared in 100% of infected rats. METHODS: Studies were conducted involving histology, immunohistochemistry, immunofluorescence and morphometric methods, in order to observe the dynamic behavior of the cellular and matrix components of fibrosis, over a one year period of evolution. RESULTS: Observation verified that septal fibrosis originates from several portal spaces simultaneously. Its origin and progression involve blood vessel proliferation (angiogenesis), multiplication of actin-positive cells (pericytes and myofibroblasts) and progressive collagen deposition. By the end of 4-5 months, a progressive decrease in all these components was observed, when signs of regression of septal fibrosis became more evident over time. CONCLUSIONS: Besides indicating the fundamental role played by angiogenesis in the pathogenesis of fibrosis, these morphological data concerning the dynamics of this C. hepatica experimental model proved to be adequate for future investigations regarding the functional aspects of fibrosis induction, progression and regression.

One-year cardiac morphological and functional evolution following permanent pacemaker implantation in right ventricular septal position in chagasic patients

INTRODUCTION: The septal position is an alternative site for cardiac pacing (CP) that is potentially less harmful to cardiac function. METHODS: Patients with Chagas disease without heart failure submitted to permanent pacemaker (PP) implantation at the Clinics Hospital of the Triângulo Mineiro Federal University (UFTM), were selected from February 2009 to February 2010. The parameters analyzed were ventricular remodeling, the degree of electromechanical dyssynchrony (DEM), exercise time and VO2 max during exercise testing (ET) and functional class (NYHA). Echocardiography was performed 24 to 48h following implantation and after one year follow-up. The patients were submitted to ET one month postprocedure and at the end of one year. RESULTS: Thirty patients were included. Patient mean age was 59±13 years-old. Indication for PP implantation was complete atrioventricular (AV) block in 22 (73.3%) patients and 2nd degree AV block in the other eight (26.7%). All patients were in NYHA I and no changes occurred in the ET parameters. No variations were detected in echocardiographic remodeling measurements. Intraventricular dyssynchrony was observed in 46.6% of cases and interventricular dyssynchrony in 33.3% of patients after one year. CONCLUSIONS: The findings of this work suggest that there is not significant morphological and functional cardiac change following pacemaker implantation in septal position in chagasic patients with normal left ventricular function after one year follow-up. Thus, patients may remain asymptomatic, presenting maintenance of functional capacity and no left ventricular remodeling.