Biomedical subjects

Z Schaff

Publications and source records attributed to Z Schaff.

130 records · Page 8Linked to original sources

PubMedDate not supplied

Additional evidence for more than one agent of human non-A, non-B hepatitis. Transmission and passage studies in chimpanzees.

Evidence supporting the existence of two agents of human non-A, non-B hepatitis was obtained by the inoculation of chimpanzees sequentially with serum from a chronically infected human (Inoculum I) and with fibrinogen prepared from pooled plasma (Inoculum IV), each of which had transmitted non-A, non-B hepatitis to humans. Passage inoculations of serum samples obtained during the acute stages of chimpanzee infections transmitted by either the agent in Inoculum I or IV also transmitted non-A, non-B hepatitis to additional chimpanzees. Transmission and passage of the agent in Inoculum IV were conducted in chimpanzees which previously had recovered from infection by the agent in Inoculum I. Cytoplasmic tubules in hepatocytes, which have been described during non-A, non-B hepatitis, were observed by electron microscopy in liver biopsies obtained during all infections transmitted by the agent in Inoculum I. These cytoplasmic tubules were not detected in liver biopsies from chimpanzees infected by Inoculum IV, except in one chimpanzee inoculated by Inoculum IV without prior exposure to the agent in Inoculum I. The cytoplasmic tubules observed in this study were found to be composed of transverse bands arranged with a periodicity of approximately 17 nm. These studies suggest that two different agents or distinct serotypes of human non-A, non-B hepatitis may have been present in these inocula, although reactivation of latent infection or reinfection could not be ruled out completely.

Animals↗

PubMedDate not supplied

Bile flow and biliary sulfobromophthalein sodium excretion in rats with liver cirrhosis and portacaval shunt.

In order to study the combined effect of end-to-side portacaval shunt and chronic liver damage on biliary organic anion transport, the rat model of thioacetamide-induced chronic liver injury was utilized. Compared with sham-operated animals, bile flow and maximal biliary excretion (Tm) of sulfobromophthalein sodium (BSP) was decreased in rats 9 weeks after shunt operation. If rats with shunts were treated for 8 weeks with thioacetamide, an agent causing hepatic fibrosis and pseudolobule formation, BSP transport from the hepatocyte into bile was further diminished. Compared with the shunted controls, the thioacetamide-treated rats with shunts had elevated serum bilirubin and alkaline phosphatase concentrations, and on electron microscopy their livers had dilated bile canaliculi with a decreased number of microvilli. Non-shunted rats treated with thioacetamide for 8 weeks had similar but less severe changes in the canalicular ultrastructure. Bile flow and BSP Tm were not influenced by thioacetamide treatment alone, perhaps due to the marked liver hypertrophy in these animals. These results indicate that canalicular active transport of organic anions is more sensitive to the effect of thioacetamide in animals with portacaval shunts than in those with sham operations. A similar impairment of hepatic organic anion handling by hepatotoxic compounds might be the consequence of portasystemic shunts in patients with liver cirrhosis.

Alkaline Phosphatase↗

PubMedDate not supplied

Occurrence of tubuloreticular inclusions in acute viral hepatitis.

Light and electron microscopy were used to study the liver needle-biopsy material of 20 patients with acute viral hepatitis. According to clinical and serologic data, 5 cases proved to be acute viral hepatitis type A, 13 were type B, and 2 were type non-A/non-B. In 2 of the hepatitis type A, in 6 of the hepatitis type B, and in one of the type non-A/non-B cases, tubuloreticular inclusions (TRI) were found in the endoplasmic reticulum of the sinusoidal endothelial cells of the liver. These data support the possible presumption that the inclusions represent a characteristic reaction of the endoplasmic reticulum to different influences, as for example to viral infection, rather than to the virus itself.

Biopsy, Needle↗

PubMedDate not supplied

Intracytoplasmic crystalline inclusions in the hepatocytes of humans and chimpanzees.

Intracytoplasmic crystalline inclusions (CCIs) were observed in liver biopsy specimens taken from three patients and three chimpanzees. CCIs are rare in human hepatocytes and have never been described in chimpanzees. All three human cases were connected with alcoholic liver disease; no viral infection was noted. The histologies of the two liver biopsy specimens obtained from healthy chimpanzees were normal, but hepatitis B virus (HBV) infection was demonstrated in the third case by immunohistochemistry and radioimmunoassay. In the last biopsy specimen a large accumulation of HBV core particles was present in the nuclei and among the filaments of CCIs of the hepatocytes. This finding suggests that crystallizations of viral proteins may form intracytoplasmic inclusions in hepatocytes, whereas in other cases toxic effects (alcohol) or normal conditions (storage) may lead to the formation of similar structures.

Animals↗