Marijuana-produced impairments in coordination. Experienced and nonexperienced subjects

The effects of marijuana and a placebo on perceptual-motor coordination, motor ability, and visual perception were compared in cannabis-experienced and naïve subjects. Impairments in coordination were observed in both groups. However, the impairment was greater in the experienced than in the naïve group.

Marijuana-produced changes in pain tolerance. Experienced and non-experienced subjects

The effect of marijuana and placebo on pain tolerance was compared in cannabis-experienced and naive subjects. A statistically significant increase in tolerance was observed after smoking marijuana. Although there was no statistically significant interaction between the drug effect and having had previous cannabis experience, there was a definite trend towards a greater increase for the experienced (16%) compared to the naive group(8%).

Bone collagen turnover in idiopathic scoliosis estimated from total hydroxyproline excretion

The turnover of bone collagen is reflected by the 24-hour excretion of urinary total hydroxyproline. In idiopathic scoliosis there is an increase above normal in the turnover of bone collagen throughout adolescence. Spinal immobilization in plaster-of-Paris, spinal traction, and spinal fusion are all accompanied by increases in the turnover of bone collagen. It is suggested that estimation of the urinary total hydroxyproline excretion is useful in monitoring spinal changes during the treatment of children with idiopathic scoliosis and may reflect otherwise unsuspected changes in the bone collagen.

Hydroxyproline excretion and height velocity in adolescent boys

The height velocity of 122 boys of 11 to 17 years is compared with their urinary total hydroxyproline excretion and a close relation is shown. The importance of this is discussed in relation to undersized children and to those with scoliosis in whom rapid growth is often associated with increasing curvature of the spine. Poor correlation was found between urinary total hydroxyproline excretion and height, weight, body surface area, and creatinine excretion.