Since nettles prefer to grow in phosphorus-rich and nitrogen rich soils that have recently been disturbed (and thus aerated), the growth of nettles is an indicator that an area has high fertility (especially phosphate and nitrate), and thus is an indicator to gardeners as to the quality of the soil.Nettles contain nitrogenous compounds, so are used as a compost activator or can be used to make a liquid fertilizer, which although low in phosphate, is useful in supplying magnesium, sulphur, and iron. They are also one of the few plants that can tolerate, and flourish in, soils rich in poultry droppings. The stinging nettle is the red admiral caterpillars primary host plant and can attract migrating red admiral butterflies to a garden. U. dioica can be a troubling weed, and mowing can increase plant density. Regular and persistent tilling will greatly reduce its numbers, and the use of herbicides such as 2,4-D and glyphosate are effective control measures. Culture
In Great Britain and Ireland, U. dioica and the annual nettle Urtica urens are the only common stinging plants and have found a place in several figures of speech in the English language. Shakespeares Hotspur urges that "out of this nettle, danger, we pluck this flower, safety" (Henry IV, Part 1, Act II Scene 3). The figure of speech "to grasp the nettle" probably originated from Aesops fable "The Boy and the Nettle".
Lipoid pneumonia is a specific form of lung inflammation (pneumonia) that develops when lipids enter the bronchial tree. The disorder is sometimes called cholesterol pneumonia in cases where that lipid is a factor. Signs and symptoms
The pneumonia presents as a foreign body reaction causing cough, dyspnea, and often fever. Hemoptysis has also been reported. Causes
Sources of such lipids could be either exogenous or endogenous.Exogenous: from outside the body. For example, inhaled nose drops with an oil base, or accidental inhalation of cosmetic oil. Amiodarone is an anti-arrythmic known to cause this condition. Oil pulling has also been shown to be a cause. Fire breathers pneumonia from the inhalation of hydrocarbon fuel is a specific variant. At risk populations include the elderly, developmentally delayed or persons with gastroesophageal reflux. Switching to water-soluble alternatives may be helpful in some situations.Endogenous: from the body itself, for example, when an airway is obstructed, it is often the case that distal to the obstruction, lipid-laden macrophages and giant cells fill the lumen of the disconnected airspace. Appearance
The gross appearance of a lipid pneumonia is that in which there is an ill-defined, pale yellow area on the lung. This yellow appearance explains the colloquial term "golden" pneumonia. At the microscopic scale foamy macrophages and giant cells are seen in the airways, and the inflammatory response is visible in the parenchyma. Treatment
Treatment is with corticosteroids and possibly intravenous immunoglobulins. Prognosis
Endogenous lipoid pneumonia and non-specific interstitial pneumonitis has been seen prior to the development of pulmonary alveolar proteinosis in a child.