Effect of Catechol-O-Methyltransferase Genotype on Self-Reported Efficacy and Activity Changes in the Brain Prefrontal Area in Response to a Caffeine Placebo / 医薬品情報学

Objective: The placebo effect can enhance the response to treatment, even in the absence of pharmacological ingredients. One possible factor explaining the likelihood of the placebo effect in individuals is genetic polymorphisms in neurotransmitters. This study focused on gene polymorphisms in the catechol-O-methyltransferase (COMT) as an interindividual variable of the placebo effect.Design・Methods: All 120 participants were explained the effects of caffeine, including its ability to ameliorate drowsiness and increase concentration, and then given a placebo (lactose). The onset of the placebo effect was measured in terms of the degree of caffeine-reduced sleepiness using subjective indices of the Stanford Sleepiness Scale (SSS) and a feeling of drowsiness-Visual Analogue Scale (VAS). The mechanism of the placebo effect was objectively examined in terms of changes in cerebral blood flow in the prefrontal cortex of the brain. In addition, we investigated participants’ susceptibility to the placebo effect by examining genetic polymorphisms in COMT.Results: After taking the drug, sleepiness on the SSS and VAS was significantly improved (p＜0.001), although there was no change in prefrontal cortex activity. Among the 120 participants, 63 had a Val/Val-type polymorphism in COMT (52.5%), 45 had a Val/Met-type (37.5%), and 12 had a Met/Met-type (10.0%). There were no significant differences among COMT gene polymorphisms in the subjective measures of SSS and VAS. However, there was a tendency for the cerebral blood flow changes to be larger in the left hemisphere of the brain in individuals with the Met/Met type.Conclusion: There seems to be a relationship between prefrontal cortex activity and genetic polymorphisms. In particular, there may be a correlation between the expression of a placebo effect and COMT gene polymorphisms.

Relationship between Bilateral Fractures of Proximal Femur and Knee Osteoarthritis / 日本農村医学会雑誌

  In recent years, the incidence of proximal femur fractures has been increasing with the aging of the population. There has been a growing number of those patients who injure on the other side of the hip at later date. We studied the relationship between proximal femurfractures and knee osteoarthritis, which is one of the diseases preceding fractures.<br>  We surveyed 234 and 17 patients hospitalized with unilateral and bilateral fractures, respectively at Atsumi Hoapital from April 2008 to March 2011. The research covered sex, age, the cause of injury, the period until they had proximal femur fractures on the other side, bilateral-fracture rate, incidence rates of diseases (cerebrovascular, eye and respiratory), knee osteoarthritis, dementia, diabetes and other forms of fracture.<br>  As a result, we confirmed the connection between knee osteoarthritis and bilateral fractures. There was every indication that knee osteoarthritis may be a major factor which leads to bilateral fractures. All patients with bilateral fracture injured resulting from falls.<br>  We believe it is important to take an approach on the treatment of hip fractures and prevention of knee osteoarthritis and falling.