Enhancing performance
Cognitive performance
In 2015, a systematic review and a meta-analysis of high quality clinical trials found that, when used at low (therapeutic) doses, amphetamine produces modest yet unambiguous improvements in cognition, including working memory, long-term episodic memory, inhibitory control, and some aspects of attention, in normal healthy adults; these cognition-enhancing effects of amphetamine are known to be partially mediated through the indirect activation of both dopamine receptor D1 and adrenoceptor α2 in the prefrontal cortex. A systematic review from 2014 found that low doses of amphetamine also improve memory consolidation, in turn leading to improved recall of information. Therapeutic doses of amphetamine also enhance cortical network efficiency, an effect which mediates improvements in working memory in all individuals. Amphetamine and other ADHD stimulants also improve task saliency (motivation to perform a task) and increase arousal (wakefulness), in turn promoting goal-directed behavior. Stimulants such as amphetamine can improve performance on difficult and boring tasks and are used by some students as a study and test-taking aid. Based upon studies of self-reported illicit stimulant use, 5–35% of college students use diverted ADHD stimulants, which are primarily used for enhancement of academic performance rather than as recreational drugs. However, high amphetamine doses that are above the therapeutic range can interfere with working memory and other aspects of cognitive control. Physical performance
Amphetamine is used by some athletes for its psychological and athletic performance-enhancing effects, such as increased endurance and alertness; however, non-medical amphetamine use is prohibited at sporting events that are regulated by collegiate, national, and international anti-doping agencies.
Necrotizing periodontal diseases is one of the seven categories of periodontitis as defined by the American Academy of Periodontology 1999 classification system and is one of the three classifications of periodontal diseases and conditions within the 2017 classification. Necrotizing periodontal diseases are a type of inflammatory periodontal (gum) disease caused by bacteria (notably fusobacteria and spirochaete species). The diseases appear to represent different severities or stages of the same disease process, although this is not completely certain. These diseases usually have a sudden onset, and so the term acute is often added to the diagnosis. The mildest on the spectrum is necrotizing ulcerative gingivitis (NUG), followed by the successively more severe conditions necrotizing ulcerative periodontitis (NUP), necrotizing stomatitis and finally cancrum oris (noma), which is frequently fatal. Necrotizing ulcerative gingivitis
Necrotizing ulcerative gingivitis, (NUG), or simply necrotizing gingivitis (NG), is a common, non-contagious infection of the gums. Acute necrotizing ulcerative gingivitis (ANUG) is the acute presentation of NUG, which is the usual course the disease takes. If improperly treated NUG may become chronic and/or recurrent. In developed countries, ANUG occurs mostly in young adults with predisposing factors such as psychological stress, sleep deprivation, poor oral hygiene, smoking, immunosuppression and/or malnutrition. In developing countries, ANUG occurs mostly in malnourished children. Due to shared predisposing factors in a population (e.g. students during a period of examinations, armed forces recruits) ANUG is known to occur in epidemic-type patterns. This has led to the popular belief that ANUG is contagious, but this is not the case.