Biomedical subjects
N N Wong
Publications and source records attributed to N N Wong.
Vergence adaptation in children and its clinical significance.
BACKGROUND AND PURPOSE: Vergence adaptation has not been well investigated in children even though it may contribute to binocular dysfunction and near work induced asthenopia. METHODS: We compared vergence adaptation in 18 children and 18 young adult subjects by assessing tonic vergence (TV) before and immediately after a period of sustained near fixation, by measuring heterophoria with a synoptophore through 0.5 mm binocular pinholes. Adaptation was induced by a reading task at 15 cm for a continuous 5 minute period. RESULTS: Mean pre-task TV values of 0.70 MA (Meter Angles) and 0.20 MA were observed for the children and young adults, respectively (p = 0.08). The initial mean vergence adaptation for children and adults was +0.45 MA and +0.11 MA, respectively (p = 0.001). CONCLUSION: The greater vergence adaptation observed in children may impact upon the clinical assessment of their binocular vision, especially heterophoria measurement which may require longer periods of dissociation than previously recommended, and might also ultimately be partly responsible for the predominant development of esodeviations during childhood
Colesevelam: a new bile acid sequestrant.
Coronary heart disease is the most prevalent form of cardiovascular disease in the United States. Hyperlipidemia--specifically, increased total and low-density lipoprotein cholesterol levels--positively correlates with the development of coronary heart disease. Colesevelam, a nonabsorbed, water-insoluble polymer, is a new bile acid sequestrant that is effective in lowering total and low-density lipoprotein cholesterol levels. In several short-term, placebo-controlled studies, colesevelam has decreased total cholesterol levels by approximately 6 to 10% and low-density lipoprotein cholesterol levels by approximately 9 to 20%. When given in combination with atorvastatin, lovastatin, or simvastatin, low-density lipoprotein cholesterol levels were decreased more than with colesevelam alone. Its unique hydrogel formulation may also minimize the potential for gastrointestinal adverse effects, which are common with other bile acid sequestrants. There have been few published studies available concerning this drug; no long-term studies and few large-scale studies have been published.
Aggrenox: an aspirin and extended-release dipyridamole combination.
Stroke is one of the leading causes of death in the United States. The risk of experiencing a recurrent stroke remains elevated for several years after an initial stroke or a transient ischemic attack (TIA), therefore secondary prevention is crucial in reducing the risk of stroke and the complications and costs associated with stroke. Aggrenox, a combination of low-dose aspirin and extended-release dipyridamole, is a new agent that is effective in the secondary prevention of stroke and transient ischemia of the brain. The clinical effect of its two antiplatelet agents are additive and significantly better than either aspirin or dipyridamole alone, although it has not been shown to be more effective than aspirin alone in preventing death. Aggrenox is much more expensive than aspirin alone but has been shown to be more cost-effective. At this point, much of the pharmacologic information concerning this combination agent is based on previous data about aspirin and immediate-release dipyridamole. This combination of aspirin and extended-release dipyridamole may play a significant role in secondary stroke and TIA prevention.
Orlistat.
Obesity is a risk factor for cardiovascular disease. Orlistat is a gastric and pancreatic lipase inhibitor indicated for the management of obesity. It is the first antiobesity agent that is not a centrally acting appetite suppressant; instead, it decreases absorption of dietary fat in the gastrointestinal tract. The effects of orlistat on weight loss, weight regain, and on a number of obesity-related risk factors have been assessed in large clinical trials of 1 to 2 years' duration. Compared with subjects who received placebo and a hypocaloric diet alone, weight loss of at least 5 to 10% of initial body weight was observed in a significantly larger number of subjects who were treated with orlistat plus a hypocaloric diet during the first year of treatment. Subjects who received orlistat 120 mg three times daily regained significantly less weight than subjects who received placebo during the second year of treatment. In addition, orlistat was found to have favorable effects on blood pressure and concentrations of serum lipid, glucose, and insulin. Gastrointestinal events are the most common adverse effects experienced by patients who received orlistat; however, most of these events were mild to moderate in intensity, transient in duration, and decreased considerably during the second year of treatment.