Perfluorooctanoic Acid Exposure Assessment on Common Carp Liver through Image and Ultrastructural Investigation

Perfluorooctanoic acid (PFOA) poses particular concern as an emerging pollutant in both surface and ground waters. Fish, as a natural inhabitant of these waters and being highly representative of vertebrates, represents an ideal animal model to assess the toxic effects of PFOA. Hereby, liver microscopic texture was comparatively evaluated in individuals of common carp subchronically exposed to PFOA using grayscale differential box counting, a fractal analysis method. Furthermore, liver cytoplasmic glycogen areas and ultrastructure were also evaluated and compared to the image analysis findings. Redundancy Analysis was performed to assess, in summary, how much the variation of fractal dimension and lacunarity was explained by the concentration of PFOA in liver, the mass of liver and the number of proliferating cell nuclear antigen (PCNA)-immunoreactive nuclei. Treatment group ordination was better determined by fractal dimension than lacunarity. Interestingly, a significant complexity increase was associated with the modification of liver microscopic texture due to PFOA exposure. This complexity increase was related to “cloudy swelling”, possibly representing a primarily adaptive strategy against PFOA challenge, rather than a slight, reversible form of degeneration as traditionally proposed. The occurrence of endoplasmic reticulum stress, unfolded protein reaction and hormetic response was proposed and discussed.

Spermatocytic Seminoma

Spermatocytic seminoma is a rare germ cell tumor distinct from classical seminoma, both clinically and pathologically. It affects older men, has not been associated with a history of cryptorchidism, and has no known counterpart in ovary or any other site. Pathologically, it is characterized by 3 distinct cell types, lack of cytoplasmic glycogen, and scant to absent lymphocytic infiltrate. Gain of chromosome 9 is the most consistent genetic abnormality. There have been few case reports of sarcomas arising in spermatocytic seminoma and only an occasional report of metastasis. It is important to differentiate this condition from its frequent mimics, such as classic seminoma and embryonal carcinoma, because patients with spermatocytic seminoma may not require further treatment after surgery.

Immunolocalization ofTaenia soliumgap junction innexins

SUMMARYIn previous studies, ultrastructural observations revealed a large number of gap junctions (GJs) in the neck and immature proglottid tissues ofTaenia soliumtapeworms. In these helminths, cytoplasmic glycogen sacs are connected by numerous discrete GJs to other cells throughout the maturing strobilar tissue. Discontinuous sucrose gradients were used to purify membrane fractions containing GJs, which were identified by ultrastructural analysis. A trans-membrane peptide sequence from a highly conserved innexin region was used to construct a 20-amino acid synthetic peptide and used to raise polyclonal antibodies in rabbits that recognized both a 55 and a 67 kDa protein in a Western blot of the GJ-enriched pellet. Immunohistochemistry of larval and adult worm sections incubated with antiserum to the synthetic peptide and a secondary anti-rabbit IgG bound to fluorescein, revealed strong binding to the tegumentary surface of the worm, as well as patchy fluorescent areas in the parenchyma. The results indicate that both the tegument of cysticerci and adultT. soliumcontain innexin-rich membranes, which may function as a tegumentary transport system for small molecules.

Successful ex Vivo Normothermic Liver Perfusion with Purely Artificial Products using Artificial Blood

We tried to make an ex vivo functioning liver with an artificial perfusate that consisted of artificial blood in the pig liver. A liver graft from a female pig weighing 20 kg was harvested in the usual manner. The perfusion solution consisted of artificial blood, L-15 medium, distilled water, bovine serum albumin, NaHCO3, NaOH, KCl, human regular insulin, 50% glucose solution, and dexamethasone. The isolated liver was perfused with this oxygenated perfusate through the portal vein at a rate of 300 ml/min for 9 hours. Seven livers were perfused for 9 hours in this system. Five of the livers showed mean oxygen consumption of over 8 ml-02/min during perfusion. Histological findings showed that the hepatic architecture was almost completely preserved and numerous hepatocytes exhibited PAS-positive cytoplasmic glycogen deposits in these livers. These observations indicate that we have succeeded in developing an ex vivo functioning liver with an artificial perfusate employing artificial blood.

Trophectodermal carcinoma: mouse teratocarcinomaderived tumour stem cells differentiating into trophoblastic and yolk sac elements

The retransplantable tumour line derived from a spontaneous ovarian murine teratocarcinoma (Fekete & Ferigno, 1952) was cloned and characterized using light and electron microscopic and immunohistochemical techniques. Grown in ascites, the tumour consisted predominantly of stem cells and a small number of differentiated derivatives. The stem cells expressed surface reactivity with antibody to SSEA-3 and Forssman antigen, alkaline phosphatase, focal cytoplasmic reactivity with antibody to SSEA-1, and varying amounts of cytoplasmic glycogen and 3 betahydroxysteroid dehydrogenase. Their cytoskeleton reacted with antibodies to keratin and vimentin. The differentiated derivatives formed approximately 5–15% of the total cell population in ascites and appeared either as giant cells or were characterized by their reactivity with antibodies to H-2 or α-foetoprotein or intracellular and pericellular laminin or high levels of 3 betahydroxysteroid dehydrogenase activity. Solid tumours produced from subcutaneously injected cells had a variegated appearance suggesting, that like the limited differentiation in the ascites, the stem cells can give rise to trophoblastic, as well as parietal and visceral yolk sac elements. On the basis of the presented data the tumour stem cells were considered as representing malignant equivalents of the common precursor of trophoblastic, visceral and parietal yolk sac cells most likely corresponding to trophectoderm. Accordingly, the tumour was designated as trophectodermal carcinoma.