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PubMed1975

Effect of carbon tetrachloride on the hepatic alkaline and acid phosphatases in a teleost fish, Heteropneustes fossils.

The effect of carbon tetrachloride on the liver of Heteropneustes fossilis was investigated in relation to the activity of phosphatases. 3 h after intraperitoneal injection, the liver showed binucleate cells, balloon cells and necrosis. The cell membrane of the hepatocytes around the biliary canaliculi is ruptured at a few places and the cellular exudates are accumulated in the canaliculi. The nucleus is enlarged and becomes pycnotic. Intense alkaline and acid phosphatase activity is observed along the cell membrane, around the nucleus and nucleolus. 5 h after injection, the liver cell membrane is ruptured and cirrhosis results. The cell volume is decreased and the contents of the cell are accumulated at a few places. The nucleus is fragmented. Strong phosphatase activity is seen throughout the cells, especially around the nucleus and cell membrane.

Acid Phosphatase↗
PubMed1979

Bioassay of complex mixtures derived from fossil fuels.

The conversion or processing of shale, coal, or petroleum involves elevated temperatures and altered pressures, and under these conditions polynuclear aromatic hydrocarbons are likely to form. Certain compounds of this type exhibit carcinogenic activity for a variety of organ sites in experimental animals and epidemiological evidence strongly implicates their role as carcinogens in man. It is then not unexpected that many liquid fractions derived from shale and coal are carcinogenic when subjected to bioassay. Benzo(a)pyrene, [B(a)P], is frequently considered to be an indicator substance. It is clear that when a small quantity of B(a)P is present in a fraction, the fraction will exhibit carcinogenic activity in a bioassay (mouse skin). However, it does not follow that the lack of detectable B(a)P insures that the fraction will be noncarcinogenic. Several fractions have been analyzed for their content of B(a)P and then subjected to bioassay. A method for testing complex mixtures for their carcinogenic potential is described. The carcinogenic potency of these fractions are compared to petroleum fractions.

Animals↗
PubMed2001

Leaf dimorphism in Archaeopteris roemeriana (Progymnosperm): further early fossil evidence of shoot dorsiventrality.

Additional information on the morphology of the vegetative ultimate branches of Archaeopteris roemeriana was obtained by uncovering compression specimens collected in Upper Devonian deposits in Belgium. For the first time, anisophylly, previously inferred from anatomical studies, is demonstrated on one species of the genus. Small leaves less than half the size of those more readily seen in unprepared compressions are borne on the adaxial surface of the ultimate branches. The phyllotaxis is discussed and the eventual adaptation to light interception of the combination of anisophylly and shoot dorsiventrality is put forward.

Journal Article↗
PubMed2001

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Animals↗