IMMUNOSTIMULATION AS ADJUVANT FOR THE CHEMOTHERAPY OF EXPERIMENTAL SCHISTOSOMIASIS

Immunosuppressed animals respond poorly to schistosomal chemotherapy and that a proper response can be restored by the administration of immune serum. Present study attempts to search whether immunological stimulation would increase drug effectiveness. Swiss mice infected with 50 S. mansoni cercariae were later treated with complete Freund's adjuvant. Treatment with oxaminiquine was made with 100 mg/kg.b.w., 25 mg/kg.b.w. and 50 mg/kg/b.w., the last two doses representing a fourth and a half of the recommended curative dose. Appropriate controls for the drug, the adjuvant and the infection were also studied. The serum-level of ant-S. mansoni antibodies (ELISA) and recovery of worms by perfusion of the portal vein system were the evaluated parameters. Statistical analysis of the results failed to reveal significant differences in worm recovery between adjuvant-stimulated animals treated with oxamniquine and any of the treated controls receiving the same amount of the drug. Although total lack of immunity interferes with curative treament the usual immune response seems to be sufficient to allow for curative drug action in schistosomiasis and thus apparently does not need to be artificially stimulated

Effect of wide spectrum anti-helminthic drugs upon Schistosoma mansoni experimentally infected mice

Mebendazole, albendazole, levamisole and thiabendazole are well known as active drugs against several nematode species, and against cestodes as well, when the first two drugs are considered. None of the drugs have proven activity, however, against trematodes. We tested the effect of these drugs on the fecal shedding of schistosome eggs and the recovering of adult schistosomes, after portal perfusion in Schistosoma mansoni experimentally infected mice. Balb/c mice infected with 80 S. mansoni cercariae were divided into three groups, each in turn subdivided into four other groups, for each tested drug. The first group was treated with each one of the studied drugs 25 days after S. mansoni infection; the second group was submitted to treatment with each one of the drugs 60 days after infection. Finally, the third group, considered as control, received no treatment. No effect upon fecal shedding of S. mansoni eggs and recovering of schistosomes after portal perfusion was observed when mice were treated with either mebendazole or albendazole. Mice treated with either levamisole or thiabendazole, on the other hand, showed a significant reduction in the recovering of adult schistosomes after portal perfusion, mainly when both drugs were given during the schistosomula evolution period, i.e., 25 days after cercariae penetration, probably due to unspecific immunomodulation

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.

A clinical, epidemological, laboratorial, histological and ultrasonographical evaluation of anti-HCV EIA-2 positive blood donors

Between 1992 and 1997, 790 blood donors with anti-HCV EIA-2 strongly reagent (relationship between the sample optical density/cut-off > 3) detected at the blood bank serological screening, were evaluated in ambulatory environment. They were all negative for Chagas disease, syphilis, hepatitis B (HBsAg) and AIDS. Blood samples were collected at the first ambulatorial evaluation, for hemogram, biochemical tests and new serological tests for HCV (anti-HCV EIA-2). In blood samples of 226 repeatedly reagent anti-HCV EIA-2 blood donors, supplementary "immunoblot" test for HCV (RIBA-2) was used. In 209 donors, the presence of HCV-RNA was investigated by the PCR test. The abdominal ultrasonography was realized in 366 donors. In 269 patients liver biopsy was performed for the histopathological study. The follow-up of blood donors showed that 95.6% were repeatedly EIA-2 reagent, 94% were symptomless and denied any hepatitis history, with only 2% mentioning previous jaundice. In 47% of this population at least one risk factor has been detected for the HCV transmission, the use of intravenous drugs being the main one (27.8%). Blood transfusion was the second factor for HCV transmission (27.2%). Hepatomegaly was detected in 54% of the cases. Splenomegaly and signs of portal hypertension have seldom been found in the physical examination, indicating a low degree of hepatic compromising in HCV. Abdominal ultrasound showed alterations in 65% of the subjects, being the steatosis the most frequent (50%). In 83.5% of the donors submitted to the liver biopsy, the histopathological exam showed the presence of chronic hepatitis, usually classified as active (89%) with mild or moderate grade in most of the cases (99.5%). The histopathological exam of the liver was normal in 1.5% of blood donors. The RIBA-2 test and the HCV-RNA investigation by PCR were positive in respectively 91.6 and 75% of the anti-HCV EIA-2 reagent donors. The HCV-RNA research was positive in 82% of the RIBA-2 positive subjects, in 37.5% of the indeterminate RIBA-2 donors and in 9% of the negative RIBA-2 donors. Chronic hepatitis has also been observed in 50% of the histopathological exams of the anti-HCV EIA-2 reagent donors which were indeterminate RIBA-2. Among 18 blood donors with minimal changes histopathological exam 11 (61%) were HCV-RNA positive. Our blood donors anti-HCV reagent generally had clinical, laboratorial and histopathological features observed in patients with chronic HCV hepatitis and a high proportion could be identified in interviews and medical evaluation realized in blood blanks. Generally, these HCV infected donors are identified and discharged only by the serological tests results.

Hepatitis B and C virus markers among patients with hepatosplenic mansonic schistosomiasis

PURPOSE: To evaluate the frequency and the consequences of the co-infection of hepatitis B and C viruses in patients with hepatosplenic schistosomiasis (HSS). METHODS: B and C serologic markers, exposure to risk factors, biochemical assays, upper gastrointestinal endoscopies, and abdominal ultrasonograms were evaluated in 101 patients with HSS from 1994 to 1997. Whenever possible, PCR was tested and histopathological studies were reviewed. RESULTS: At least one HBV virus marker was found in 15.8%, and anti-HCV was detected in 12.9% of the subjects. The seropositive subjects tended to be older than the seronegative ones. A history of blood transfusion was significantly related to the presence of anti-HCV. Three (18.75%) out of 16 subjects exposed to B virus were HBsAg positive. Eleven (84.6%) out of thirteen patients who were anti-HCV positive demonstrated viral activity. Patients with ongoing viral infection presented a higher average level of liver aminotransferases, a higher frequency of cell decompensation and a higher rate of chronic hepatitis. Portal hypertension parameters were not influenced by viral exposure. CONCLUSIONS: The rate of hepatitis B and C viruses serologic markers observed in the patients with HSS was higher than the control group. The co-infection was responsible for a higher frequency of cell decompensation.

Liver histology in co-infection of hepatitis C virus (HCV) and Hepatitis G virus (HGV)

As little is known about liver histology in the co-infection of hepatitis C virus (HCV) and hepatitis G virus (HGV), HGV RNA was investigated in 46 blood donors with hepatitis C, 22 of them with liver biopsy: co-infection HCV / HGV (n = 6) and HCV isolated infection (n = 16). Besides staging and grading of inflammation at portal, peri-portal and lobular areas (Brazilian Consensus), the fibrosis progression index was also calculated. All patients had no symptoms or signs of liver disease and prevalence of HGV / HCV co-infection was 15.2%. Most patients had mild liver disease and fibrosis progression index, calculated only in patients with known duration of infection, was 0.110 for co-infection and 0.130 for isolated HCV infection, characterizing these patients as "slow fibrosers". No statistical differences could be found between the groups, although a lesser degree of inflammation was always present in co-infection. In conclusion co-infection HCV / HGV does not induce a more aggressive liver disease, supporting the hypothesis that HGV is not pathogenic.

Treatment with mebendazole is not associated with distal migration of adult Angiostrongylus costaricensis in the murine experimental infection

Abdominal angiostrongyliasis is a zoonotic infection produced by a metastrongylid intra-arterial nematode, Angiostrongylus costaricensis. Human accidental infection may result in abdominal lesions and treatment with anti-helminthics is contra-indicated because of potential higher morbidity with excitement or death of worms inside vessels. To evaluate the effect of mebendazole on localization of the worms, male Swiss mice, 5 week-old, were infected with 10 third stage larvae per animal. Twelve infected mice were treated with oral mebendazol, at 5 mg/kg/day, for 5 consecutive days, begining 22 days after inoculation. As control groups, 12 infected but non-treated mice and other 12 non-infected and non-treated mice were studied. The findings at necropsy were, respectively for the treated (T) and control (C) groups: 92% and 80% of the worms were inside the cecal mesenteric arterial branch; 8% and 10% were located inside the aorta. Only in the group C some worms (10%) were found inside the portal vein or splenic artery. These data indicate that treatment with mebendazole does not lead to distal or ectopic migration of A. costaricensis worms.

HYPOXIC STRESS, HEPATOCYTES AND CACO-2 VIABILITY AND SUSCEPTIBILITY TO Shigella flexneri INVASION

SUMMARY Inflammation due to Shigella flexneri can cause damage to the colonic mucosa and cell death by necrosis and apoptosis. This bacteria can reach the bloodstream in this way, and the liver through portal veins. Hypoxia is a condition present in many human diseases, and it may induce bacterial translocation from intestinal lumen. We studied the ability of S. flexneri to invade rat hepatocytes and Caco-2 cells both in normoxic and hypoxic microenvironments, as well as morphological and physiological alterations in these cells after infection under hypoxia. We used the primary culture of rat hepatocytes as a model of study. We analyzed the following parameters in normoxic and hypoxic conditions: morphology, cell viability, bacterial recovery and lactate dehydrogenase (LDH) released. The results showed that there were fewer bacteria within the Caco-2 cells than in hepatocytes in normoxic and hypoxic conditions. We observed that the higher the multiplicity of infection (MOI) the greater the bacterial recovery in hepatocytes. The hypoxic condition decreased the bacterial recovery in hepatocytes. The cytotoxicity evaluated by LDH released by cells was significantly higher in cells submitted to hypoxia than normoxia. Caco-2 cells in normoxia released 63% more LDH than hepatocytes. LDH increased 164% when hepatocytes were submitted to hypoxia and just 21% when Caco-2 cells were in the same condition. The apoptosis evaluated by Tunel was significantly higher in cells submitted to hypoxia than normoxia. When comparing hypoxic cells, we obtained more apoptotic hepatocytes than apoptotic Caco-2 cells. Concluding our results contribute to a better knowledge of interactions between studied cells and Shigella flexneri. These data may be useful in the future to define strategies to combat this virulent pathogen.

LIVER BIOPSY: IMPORTANCE OF SPECIMEN SIZE IN THE DIAGNOSIS AND STAGING OF CHRONIC VIRAL HEPATITIS

Liver biopsy is the gold standard method for the grading and staging of chronic viral hepatitis, but optimal biopsy specimen size remains controversial. The aim of this study was to evaluate the quality of liver specimen (number of portal tracts) and to evaluate the impact of the number of portal tracts in the staging of chronic hepatitis. Material and Methods: 468 liver biopsies from consecutive patients with hepatitis C virus and hepatitis B virus infection from 2009 to 2010 were evaluated. Results: The length of fragment was less than 10 mm in 43 cases (9.3%), between 10 and 14 mm in 114 (24.3%), and ≥ 15 mm in 311 (64.4%); of these, in 39 (8.3%) cases were ≥ 20 mm. The mean representation of portal tracts was 17.6 ± 2.1 (5-40); in specimens ≥ 15 mm the mean portal tract was 13.5 ± 4.7 and in cases ≤ 15 mm was 11.4 ± 5.0 (p = 0.002). Cases with less than 11 portal tracts were associated with F3, and cases with 11 or more portal tracts with F2 (p = 0.001). Conclusion: this study demonstrated the good quality of liver biopsy and a relationship between the macroscopic size of the fragment and the number of portal tracts.

Esquistossomose pulmonar. II. Forma crônica reativada com hipertensão e Cor pulmonale

Os Autores descrevem um caso grave de esquistossomose mansoni (forma hepática com hipertensão portal associada a forma pulmonar com hipertensão pulmonar e cor pulmonalej sobre o qual evoluiu uma sindrome toxi-infectuosa grave e de longa duração. Sucessivos exames radiológicos do tórax revelaram acometimento predominantemente arteriolar, ao lado de uma micronodulação pulmonar grosseira e difusa em ambos os hemitóraces e configuração de coração pulmonar. A histopatologia de material de biópsia pulmonar identificou basicamente uma arterite pulmonar característica, inflamação granulomatosa atípica provocada principalmente por vermes e raros ovos de S. mansoni envolvidos por escassa reação inflamatória. Para explicar a origem de constelação clínica toxi-infectuosa, foram afastadas as hipóteses de associação da esquistossomose a concausas infectuosas ou não, mas de curso febril, e a superposição de uma forma toxêmica sobre outra crônica pré-existente. Com base em dados clínicos, particularmente em subsídios da laparoscopia, e anatômicos, concluiu-se tratar o caso de uma forma crônica de esquistossomose reativada, provavelmente em virtude de alterações imunológicas inusitadas do hospedeiro. Ao que tudo parece indicar, o desvio de ovos e de vermes aos pulmões deveu-se à sindrome de hipertensão portal, cujos shunts entre a circulação portal e sistêmica determinaram a rota preferencial da migração.

Bioquímica da esquistossomose mansônica. VI - alterações do compartimento lisossômlco hepático relacionadas ao tempo de infecção

O Schistosoma mansoni e/ou seus ovos causam uma hepatopatia muito importante e com aspectos anátomo-clínicos bem característicos. Uma vez carregados pela corrente circulatória, os vermes podem ocluir ramos dicotômicos de maior calibre do sistema portal e, quando mortos produzem lesões às vezes extensas, primeiro necróticas, depois inflamatórias e, posteriormente cicatriciais, sempre circunscritas e não sistematizadas. Os ovos, além de penetrarem no's ramúsculos não dicotômicos da rede periductal, alcançam os ramos de distribuição ou até mesmo as vênulas aferentes, ocluin- do muitas delas e, como conseqüência, formam os granulomas intravasculares que podem levar a uma interrupção da corrente sangüínea portal a esse nível e alterações da circulação intralobular. A diminuição da taxa de oxigênio disponível e conseqüentemente o decréscimo do pH intra e extracelular são potentes labilizadores das membranas dos diversos componentes do compartimento lisossômico. A saída de hidrolases ácidas, proteínas catiônicas e hidrolases neutras, a partir desses orgãnulos, acarreta agressões tissulares muito importantes, com o desencadeamento e/ou manutenção dos processos inflamatórios típicos desta parasitose. Neste trabalho estudou-se as atividades lisossômicas ligadas às diversas fases da esquistossomose mansônica hepática. Os resultados indicaram que a integridade funcional dos complexos membranosos do compartimento lisossômico foi significativamente alterada, já a partir do segundo mês da infecção e que parece haver um estreito relacionamento entre o agravamento das lesões inflamatórias hepáticas com uma maior labilidade lisossômica.

Labrea-like hepatitis in Vitoria, Espirito Santo state, Brazil: report of a case

A case of fulminat hepatitis with microvesicular steatosis resembling Labrea 's fever, diagnosed in Vitoria (ES) is reported. The 16 year old bcy presented with severe epistaxis, agitation, jaundice and hemorrhagic vomiting and died two days after admission to the emergency unit of the Vnivesity Hospital. The disease started five days before with fever, myalgias, dark urine and jaundice andprogressed withpsychic agitation, torpor and coma. The liver andspleen were notpalpable. HBsAg was negative in the serum. The autopsy showed acute hepatitis with tylic necrosis confluent in the midizonal and periportal areas with massive microvesicular steatosis in the remaining hepatocytes. Mononuclear cellspredominated in the exudate. The reticulum showed condensation in the necrotic areas without typical bands of collapse. The portal tracts were edematous with mononuclear infiltration and mild bile duct proliferation. Absence of cholestasis. Exceptfor the confluent midzonalandperiportal necrosis this case showed several clinical and morphological aspects of the Labreafever describedfrom the East Amazon, demonstrating that the anatomical picture of this disease probabty is not in related to afactor peculiar to the Amazon region.

A clinico-pathological study of 163 untreated cases of chronic hepatitis C

We performed a clinico-pathological study of 163 untreated cases of chronic hepatitis C. Eighty five percent of the patients were clinically asymptomatic and their physical examinations sbowed unremarkable or minimal changes at the time of the liver biopsy Liver function tests tended to present slight abnormalities, involving mild elevations of the activity of the aminotransferases and gamma-glutamil transferase levels. In spite of these mild abnormalities advanced chronic liver disease ivas histologically detected in eighty nine percent of the patients, mainly showing chronic active hepatitis. The most characteristic histological finding ivas an interlobular bile duct damage which correlated with the presence of tymphoid aggregates in the portal tracts and with the development of fibrosis.

Sobre a reversão da fibrose hepática esquistossomótica após terapêutica específica. Estudo histológico

Biópsias cirúrgicas de fígado de portadores da forma hepatesplênica compensada da esquistossomose mansônica, previamente tratados com oxaminiquine (Mansil) e submetidos, posteriormente, à anastomose esplenorrenal, foram estudadas através de algumas técnicas histológicas e imunohistoquímicas. Embora a pesquisa de vermes adultos, de ovos e/ou de granulomas fosse negativa, em todos os espécimes examinados, a fibrose portal estava presente.

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.