The double-edged sword of COX-2 selective NSAIDs

THE LAUNCH OF THE CYCLOOXYGENASE-2 (COX-2) selective NSAIDs was based on 2 hypotheses: (1) the major adverse effects limiting the usefulness of nonselective NSAIDs are gastrointestinal in nature and (2) COX-2 selective NSAIDs are associated with fewer gastrointestinal adverse effects than nonselective NSAIDs. At the time of the launch, neither of these hypotheses had been proven and, as documented in this review, both remain uncertain. The increased incidence of total and nongastrointestinal serious adverse events, with the COX-2 selective NSAIDs as compared with nonselective NSAIDs, in the Celecoxib Long-term Arthritis Safety Study (CLASS) and the Vioxx Gastrointestinal Outcomes Research (VIGOR) study remains a major concern. The increased morbidity associated with the COX-2 selective NSAIDs may be a manifestation of the COX-2 selectivity of rofecoxib and celecoxib or the supramaximal doses of these drugs used in the trials. Proof that the increased harm was not caused by the COX-2 selectivity of the drugs depends on demonstration in a randomized controlled trial that COX-2 selective NSAIDs at usual doses are as effective as nonselective NSAIDs and cause fewer gastrointestinal serious adverse events without increasing the incidence of total nongastrointestinal serious adverse events.     

T1D发病中的双刃剑——iNKT细胞

1型糖尿病(type 1 diabetes,T1D)是一种由遗传因素、环境因素和免疫调节因素共同参与的自身免疫性疾病。由于免疫系统的功能紊乱和调节异常,胰岛β细胞受损,导致胰岛素缺乏,糖代谢紊乱。恒定自然杀伤T(invariant nature killer T,iNKT)细胞是一种同时参与适应性免疫和固有免疫应答的特殊T细胞亚群。近年来发现iNKT细胞与T1D的发病密切相关,虽然有关报道众多但结论不一。旨在对这一领域的最新研究进展进行综述。     

Pregnane X receptor: a double-edged sword

During the last decade, much progress has been made in exploring the mechanisms of alterations elicited by foreign compounds in xeno- and endobiotic metabolism regulated by the human nuclear pregnane X receptor （PXR）. PXR, identified as a human nuclear receptor in 1998 and generally regarded as a sensor activated by exogenous and endogenous chemicals, regulates a large number of enzymes and transporters involved in the response of mammals to their chemical environment.     

Eye injuries in Canadian hockey.

Increasing public concern led the Canadian Ophthalmological Society, in January 1974, to form a committee to study the incidence, types and causes of hockey eye injuries and to devise means of reducing such injuries. Retrospective and current studies were undertaken, and face protectors were tested. In both pilot studies, sticks were the commonest cause and the highest number of eye injuries was in players 11-15 years old. An average of 15% of all injured eyes were rendered legally blind. Cooperation with hockey authorities has resulted in changed rules and their sticter enforcement, and formulation of standards for face protection approved by the Canadian Standards Association. In this interim report the committee recommends that all amateur hockey players wear eye protectors and urges ophthalmologists to participate in efforts to improve the design of protective equipment.     

Retinal detachment following hockey injury.

Thirty-three cases of retinal detachment following hockey injury were seen during a 15-year period at the retina clinic of Maisonneuve-Rosemont Hospital, Montreal. Most injuries occurred in adolescents, the average age being 18 years. The mean interval between injury and preoperative examination was 3 years. Almost half of these young hockey players remained legally blind in the affected eye even after a successful operation. A helmet with a protective face visor is suggested as the best prevention against severe ocular damage such as retinal detachment.     

National survey of spinal injuries in hockey players

There has been an alarming increase in the number of spinal injuries in hockey players. Between 1976 and 1983, 42 were reported to the Committee on Prevention of Spinal Injuries due to Hockey. The median age of the injured players was 17 years. Of the 42 players 28 had spinal cord injuries, and 17 of them had complete paralysis below the vertebral level of the injury. Strikes from behind and collisions with the boards were common mechanisms of injury. Many of the players had suffered a burst fracture of the cervical spine following a blow to the top of the helmet when the neck was slightly flexed. The committee studied a number of possible etiologic factors and made several recommendations regarding prevention. League officials, coaches, players and equipment manufacturers can all play a role in prevention.