1. The range of variation in full extension at the interphalangeal and metacarpo-phalangeal joints of the thumbs of 133 male and 100 female Europeans, and of 31 male Indians and 30 male Africans, has been investigated. 2. There is considerable variation between individuals in the maximum extension of both joints of the right and left thumbs in all groups studied. 3. The distribution for each joint in both thumbs in all groups is fairly symmetrical. 4. There is a high correlation between the right and left thumbs for both joints in all groups 5. The mean angle of extension at the right and left metacarpo-phalangeal joints in all groups is similar. Female Europeans, however, show a significantly greater mean angle than male Europeans. 6. The mean interphalangeal angle of extension in male Europeans is significantly greater than that in female Europeans and the mean in the Indian and African groups is significantly greater than in the male European group. 7. There is slight negative correlation between the metacarpo-phalangeal angle and interphalangeal angle in each thumb in the European groups. 8. Many subjects in all groups can increase extension at the metacarpo-phalangeal joint after flexing the carpo-metacarpal joint. Marked hyperextension (over 40°) is more frequent in the left than in the right thumb, in females than in males, and in male Indians than in male Europeans and Africans. 9. Maximum extension at the interphalangeal joints is not related to the presence of a sesamoid bone in the anterior part of the capsule of the joint. 10. The surfaces of the metacarpo-phalangeal joints vary considerably in shape. Those which are flat form about 10 per cent. of the sample and do not show hyperextension. 11. The factors influencing the amount of extension at the interphalangeal joint is the degree of laxity of the anterior capsule. The problem at the metacarpo-phalangeal joint is more complex; both the capsule and the shape of the joint surfaces play important roles.
Platelets play an important part in normal haemostasis, and are likely to be involved in the thromboembolism seen in the primary antiphospholipid syndrome (PAPS). Evidence exists for platelet activation in this disorder, and new flow cytometric techniques have made it possible to detect low levels of activation. We have previously studied the expression of the platelet activation markers CD62p and CD63, percentage of reticulated platelets, and levels of soluble P-selectin in a group of PAPS patients. Median platelet CD63 expression and plasma soluble P-selectin levels were significantly increased in PAPS patients compared to a group of controls; there was no difference in reticulated platelet percentages between the two groups. Additional assays of platelet activation (PAC-1 expression, Annexin V binding, platelet microparticles and complexes) are being developed and assessed with respect to disease activity, thrombosis risk and effects of antithrombotic therapy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.