Tree pine ("Pinus" species) the bark exudes sticky resin which deters attackers whereas in rubber trees ("Hevea brasiliensis") it is a milky latex that oozes out. The quinine bark tree ("Cinchona officinalis") contains bitter substances to make the bark unpalatable. Large tree-like plants with lignified trunks in the Pteridophyta, Arecales, Cycadophyta and Poales such as the tree ferns, palms, cycads and bamboos have different structures and outer coverings. Although the bark functions as a protective barrier, it is itself attacked by boring insects such as beetles. These lay their eggs in crevices and the larvae chew their way through the cellulose
Analgesic nephropathy of paracetamol into "N"-acetyl-"p"-benzoquinoneimine (NAPQI). NAPQI depletes glutathione via non-enzymatic conjugation with glutathione, a naturally occurring antioxidant. With depletion of glutathione, cells of the kidney become particularly sensitive to oxidative damage. Diagnosis is traditionally based on the clinical findings above in combination with excessive analgesic use. It is estimated that between 2 and 3 kg each of phenacetin or aspirin must be consumed before evidence of analgesic nephropathy becomes clinically apparent. Once suspected, analgesic nephropathy can be confirmed with relative accuracy using computed tomography (CT) imaging without contrast. One trial demonstrated that the appearance of papillary calcifications on CT imaging