Rock climbing injuries.

Rock climbing has become increasingly popular in the past decade. However, the increased participation exposes a greater number of climbers to potential injury. The risks involved with climbing increase in proportion to the skill-level of the climber: the higher the skill-level, the more hours are required for training and on more difficult routes. The hands are used as tools for the ascent, with much of the climber's weight placed upon the fingers and also distributed through the wrist, elbow and shoulders. The combination of repetitive climbing and the excessive weight-bearing demands of the sport result in cumulative trauma to the upper limbs. Prevention should begin with educating climbers on the potential risk for injury. Although adequate rest between climbs and decreased training when pain is first encountered would aid in alleviating numerous problems, additional search directed towards improving training, treatment and rehabilitation programmes is warranted.

CD4+CD8- T cells are the effector cells in disease pathogenesis in the scurfy (sf) mouse.

Mice hemizygous for the X-linked mutation, scurfy (sf), exhibit a fatal lymphoreticular disease that is mediated by T lymphocytes. To evaluate the respective roles of CD4 or CD8 single positive T cells in scurfy disease, neonates were treated with mAbs directed against the CD4 or CD8 molecules. Whereas mice treated with an anti-CD8 Ab developed lesions and succumbed to disease at the same time (17 days) as their untreated scurfy littermates, mice treated with an anti-CD4 Ab lived up to 11 wk before developing scurfy disease. To insure a more complete elimination of the T cell subsets, the scurfy mutation was bred onto beta 2-microglobulin (beta 2m)-deficient (CD8-less) and CD4-deficient transgenic mouse lines. Whereas there was little moderation of disease in beta 2m-deficient scurfy mice, CD4-deficient scurfy mice had markedly decreased scurfy lesions and a prolonged life span, similar to that of anti-CD4-treated sf/Y mice. Additionally, scurfy disease was transplanted into H-2-compatible nude mice through the adoptive transfer of CD4+CD8- T cells, but not CD4-CD8+ T cells. Flow-cytometric analysis revealed that sf/Y mice have an increased percentage of activated CD4+ T cells in their lymph nodes. In addition, there is an increase in the in vitro production of cytokines in the cultured splenocytes of CD8-less, but not CD4-less, scurfy mice. These data suggest that CD4+ T cells are critical mediators of disease in the scurfy mouse.

Event-related brain potentials (P300) and neuropsychological deficit in patients with focal brain lesions.

Sixteen patients with chronic focal brain lesions were investigated with an acoustic P300 test and psychological tests of spatial abilities (Maze Tracing Speed Test, Form Board Test), cognitive speed (Sequential Number Connection Test), categorization (Figure Sorting Test), verbal fluency and vigilance. Neither the psychological battery nor P300 analysis discriminated frontal from retrorolandic brain lesions. Abnormalities of P300 significantly correlated with impairments in those psychological tests which had a spinal component in common. We suggest that abnormality of the P300 with focal brain damage rather indicates higher mental function impairment than direct effects of the lesion.