Related Experiment Videos
Non-A, non-B hepatitis: ultrastructural evidence for two agents in experimentally infected chimpanzees
Abstract:
Two different ultrastructural alterations were observed in liver cells of chimpanzees inoculated with plasma derived from two different patients with non-A, non-B hepatitis. During the acute phase of illness in one group of four chimpanzees, peculiar tubular structures, composed of two unit membranes with electron-opaque material in between, were observed in the cytoplasm of hepatocytes. In contrast, these structures were never detected in the liver cells of the second group of five chimpanzees that received the second inoculum, However, nuclear changes, usually associated with aggregates of 20- to 27-nanometer particles, were found in hepatocytes of the latter animals. Although these particles resembled viruses, they were not as uniform as small virus particles often appear. In five other chimpanzees inoculated with non-A, non-B hepatitis material not known to be related to the first two inocula, cytoplasmic structures were found in four, and nuclear structures were found in the remaining one. Thus, all 14 chimpanzees inoculated with transmissible non-A, non-B hepatitis agents could be classified as having either nuclear or cytoplasmic changes. These observations add support to epidemiologic data suggesting that there may be more than one agent of non-A, non-B hepatitis.
Insights
Ultrastructural analysis of non-A, non-B hepatitis in chimpanzees revealed distinct cytoplasmic tubular structures and nuclear viral-like particles. These findings support the hypothesis of multiple infectious agents causing non-A, non-B hepatitis.
Area of Science:
- Hepatology
- Virology
- Electron Microscopy
Background:
- Non-A, non-B hepatitis is a significant cause of viral hepatitis.
- The causative agents of non-A, non-B hepatitis remain largely unidentified.
- Transmission studies in chimpanzees are crucial for understanding hepatitis viruses.
Purpose of the Study:
- To investigate the ultrastructural changes in chimpanzee liver cells infected with non-A, non-B hepatitis agents.
- To determine if distinct morphological alterations correlate with different etiological agents.
- To provide evidence supporting the existence of multiple non-A, non-B hepatitis viruses.
Main Methods:
- Inoculation of chimpanzees with plasma from non-A, non-B hepatitis patients.
- Transmission electron microscopy of liver biopsies.
- Ultrastructural examination of hepatocytes for specific morphological changes.
Main Results:
- Two distinct ultrastructural alterations were observed: peculiar cytoplasmic tubular structures and nuclear aggregates of viral-like particles.
- Chimpanzees inoculated with one agent developed cytoplasmic changes, while another group showed nuclear alterations.
- All inoculated chimpanzees exhibited either cytoplasmic or nuclear changes, correlating with the inoculum source.
Conclusions:
- The observed distinct ultrastructural changes in chimpanzee hepatocytes support the existence of multiple transmissible agents responsible for non-A, non-B hepatitis.
- These findings complement epidemiological data suggesting etiological heterogeneity.
- Electron microscopy provides valuable insights into the morphology of unidentified hepatitis viruses.