Hepatocarcinoma en hígado no cirrótico / Hepatocellular carcinoma in a non cirrhotic liver

Background: The appearance of hepatocellular carcinoma in non-cirrhotic livers is uncommon. Material and Method: We report a 62 years old woman presenting with a liver mass that was subjected to a left hepatectomy. Results: The pathology report disclosed a poorly to moderately differentiated hepatocellular carcinoma. The surrounding liver tissue was normal. Immunohistochemistry identified intracytoplasmic a-1 antitrypsin granules, confirming the suspicion of a-1 antitrypsin deficiency.

Introducción: El Carcinoma Hepatocelular (HCC), tumor hepático primario más frecuente, se presenta en general en hígados cirróticos. Un porcentaje menor se desarrolla en pacientes sin cirrosis, en los cuales deben buscarse otras etiologías. Paciente y Método: Se presenta un caso clínico y las características anato-mopatológicas de una paciente con hepatocarcinoma e hígado no cirrótico tratada en nuestro centro. Mujer de 62 años, con historia de dolor abdominal y baja de peso. Estudio por imágenes revela masa hepática de aproximadamente 8 cm de diámetro mayor, en segmentos II, III y IV, sugerente de HCC. Resultados: Se realiza hepatectomía izquierda. Evoluciona de forma satisfactoria en el postoperatorio. La biopsia muestra un HCC moderada a pobremente diferenciado. El tejido no tumoral es normal, con gránulos intracitoplasmáticos Pas y Pas diastasa (+). Inmunohistoquímica identifica gránulos intracitoplasmáticos de antitripsina, con lo que se confirma la sospecha diagnóstica de déficit de a-1 antitripsina.

Infectious haemolytic anaemia causes jaundice outbreaks in seawater-cultured coho salmon, Oncorhynchus kisutch (Walbaum), in Chile.

In the last 9 years, epizootics of an icterus condition has affected coho salmon, Oncorhynchus kisutch (Walbaum), reared in seawater cages in southern regions of Chile. At necropsy, fish from field cases exhibited signs of jaundice accompanied by pale light-brown livers and dark spleens. Histopathological and haematological results indicated that these fish presented haemolytic anaemia. After microbiological examination no bacterial or viral agents could be identified as aetiological agents of this disease. In an infectivity trial, coho salmon, Atlantic salmon, Salmo salar L., and rainbow trout, Oncorhynchus mykiss (Walbaum), were inoculated intraperitoneally with a filtrate of an organ homogenate (0.45 microm) from a diseased coho salmon and held for 60 days in tanks supplied with fresh water. The disease was only reproduced in coho salmon in which mortalities, beginning at day 23 post-inoculation (p.i.), reached a cumulative value of 24% at day 27 p.i. This condition was transmitted to non-inoculated cohabiting coho salmon suggesting that it is a waterborne disease. Thus, this icteric condition is caused by an infectious form of haemolytic anaemia, probably of viral aetiology, and coho salmon are more susceptible than either Atlantic salmon or rainbow trout.

Experimental infection of coho salmon Oncorhynchus kisutch by exposure of skin, gills and intestine with Piscirickettsia salmonis.

Piscirickettsiosis pathogenesis was examined using some tissues as entry portals of Piscirickettsia salmonis in coho salmon. Juvenile fish, weighing approximately 8.4 g, were used in this trial. Inocula were prepared using the strain SLGO-95 of P. salmonis. The micro-organism was cultured in the CHSE-214 cell line as described by Fryer et al. (1990) and doses containing 10(4.7) and 10(3.7) TCID50 were prepared. Each dose was used to infect the fish via skin, gills and intestine. Skin and gills were exposed by calibrated drops, and the intestine by an intubation through the anal opening. Some fish were injected intraperitoneally with the same P. salmonis doses, as positive virulence controls. Sham-inoculated fish for each of the tested routes were also included as negative controls. Piscirickettsiosis was experimentally reproduced with all the inoculation methods. Cumulative mortalities and survival analyses showed that the most effective entry portal was skin followed by intestinal intubation and finally by gill infection.

Experimental vertical transmission of Piscirickettsia salmonis and in vitro study of attachment and mode of entrance into the fish ovum.

Piscirickettsia salmonis is a pathogenic bacterial agent causing septicaemic disease in salmon. Since its isolation in Chile in 1989, P. salmonis has continually produced high mortality rates in salmon farms. Little information exists regarding the mechanisms of vertical transmission of this pathogen. Experimental vertical transmission was established in the present study by inoculation of male and female rainbow trout broodstock with P. salmonis. The bacterium was subsequently detected using indirect immunofluorescence in milt and coelomic fluid of the majority of inoculated broodstock (14/15). Bacteria were detected in the fry when 1 or both parents were inoculated, although none of the infected fry presented signs of the disease. P. salmonis was also detected in progeny obtained through fertilisation ova from non-inoculated females incubated in a medium containing a bacterial suspension, demonstrating transmission during the process of fertilisation. Ova infected in vitro were examined at sample periods from 30 s to 60 min using scanning electron microscopy. This demonstrated that the bacterium attaches to the ova by means of membrane extensions, structures which we have called 'piscirickettsial attachment complex' (PAC) and which would allow later penetration into the ovum.

Routes of entry of Piscirickettsia salmonis in rainbow trout Oncorhynchus mykiss.

Since 1989, Piscirickettsia salmonis, the causal agent of piscirickettsiosis, has killed millions of farmed salmonids each year in southern Chile. The portal of entry for the pathogen was investigated by use of selected experimental infections in juvenile rainbow trout (12 g). The methods used were intraperitoneal injection, subcutaneous injection, patch contact on skin, patch contact on gills, intestinal intubation and gastric intubation. Cumulative mortalities at Day 33 post-inoculation were 98, 100, 52, 24, 24, and 2%, respectively. It was shown that intact skin and gills could be penetrated by P. salmonis. The high mortality obtained in subcutaneously injected fish indicated that skin injuries could facilitate the invasion of this pathogen. Results suggested that the main entry sites are through the skin and gills and that the oral route may not be the normal method by which P. salmonis initiates infection of salmonids.

Immunization with bacterial antigens: piscirickettsiosis.

Piscirickettsiosis is a septicaemic disease of salmonid fish caused by the obligated intracellular rickettsia, Piscirickettsia salmonis. This disease was first reported in 1989 in salmon cultured in sea water netpens in southern Chile where it is still a major problem causing high mortality among cultured salmonids. In recent years related agents have been reported in farmed salmonids from Ireland, Canada and Norway. Mortality, however, at these locations has been reported to be low. Because of the recent description of piscirickettsiosis and its aetiological agent, knowledge about the immune response of fish against this organism is limited. At present, there is only one paper in the literature dealing with this subject. To standardise challenge methods for testing the efficacy of vaccination, lethal dose 50% and infectivity dose 50% were determined for coho salmon (Oncorhynchus kisutch) and rainbow trout (O. mykiss) using intraperitoneal (i.p.) injections of P. salmonis. Experiments using bath challenge methods failed to reproduce the disease using rainbow trout although low levels of infection in their tissues were found. In a field trial, using formalin killed bacterins injected i.p. into pre-smolt coho salmon, the fish were naturally challenged by placing them in sea water where endemic piscirickettsiosis occurred. The results showed that some of the vaccinated fish groups experienced lower cumulative mortality than the non-vaccinated control group (X < 0.05), suggesting an immunoprotective response in these animals. A trial was also conducted with formalin-killed bacterins in rainbow trout using different antigen concentrations with and without booster injections. Fish were challenged by IP injection of P. salmonis. Vaccinated fish showed less mortality than their respective infected control. Unfortunately the challenge was not strong enough because mortality in the infected control fish was low (20%). Antibody levels measured by radio-immuno-assay increased until day 40 post vaccination. The highest levels of antibody were obtained in the sera of fish vaccinated with concentrated antigen using booster injections.

Pathogenicity of chicken anaemia virus (isolate 10343) for young and older chickens.

One-day-old chicks, inoculated intramuscularly (i.m.) with the chicken anaemia virus (CAV) isolate 10343, showed depression of body weight gain and anaemia, particularly between days 14 and 21 post-inoculation (p.i.)- The weights of thymus and bursa were substantially reduced compared to controls at days 14 and 21 p.i. The histological lesions detected in thymus, bursa, spleen and liver were similar in frequency at days 14 and 21 p.i. Eosinophilic intranuclear inclusion bodies, lymphocyte depletion, and focal necrosis were detected in the thymus, spleen, bursa and liver of more than 50% of the inoculated chicks at days 14 and 21 p.i. Focal necrosis and vacuolar degeneration in the liver, as well as apoptosis in different organs were more evident at days 14 and 21 p.i. Ten-week-old broiler breeders, inoculated i.m. with isolate 10343 showed pathological changes that were less severe than the changes shown by 1-day-old chicks. No anaemia could be detected in this group. However, severe thymus atrophy, and histological lesions in bursa, spleen, and liver, were also evident at days 14 and 21 p.i. in some of the inoculated birds. Viral detection by immunofluorescence using a monoclonal antibody revealed a wide distribution of the CAV isolate. CAV antigen was detected until day 21 p.i. in thymus, spleen, bursa and liver. According to the severity of the lesions shown by 1-day-old chicks, the length of the period in which CAV antigen could be detected in tissues, and the fact that CAV isolate 10343 was capable of inducing disease in 10-week-old chickens, it seems that this CAV isolate may be particularly virulent.

Avian infectious bronchitis: viral persistence in the harderian gland and histological changes after eyedrop vaccination.

The histological changes in the harderian gland (HG) induced by the attenuated H-120 infectious bronchitis virus (IBV) vaccine strain and the persistence of this virus in the stroma of the gland was evaluated in chickens after eyedrop vaccination. Virus replication induced an increase in IBV-specific enzyme-linked immunosorbent assay antibody levels from marginal levels at vaccination (26 days of age) to significantly higher levels 10 days after exposure. IBV antigen was detected in the HG by both immunofluorescence using a monoclonal antibody and virus reisolation in embryonated chickens eggs until day 14 postvaccination. Lymphocytic, heterophilic, erythrocytic, and plasma cell infiltration as well as epithelial cell integrity in collecting tubules and acini were evaluated in the HG throughout the experimental period. IBV vaccination with the attenuated vaccine strain H-120 resulted in partial damage to the HG, as demonstrated by both the presence of plasma cells showing Russell bodies and by tubule epithelial cell exfoliation that occurs simultaneously with the presence of detectable IBV. The increase in plasma cell number and the enlargement of lymphoid foci appear to be expressions of the immunocompetence of this paraocular gland.