蛇床子素对豚鼠离体回肠和结肠带的作用

以豚鼠离体回肠和结肠带为标本,观察蛇床子素(Ost)的作用与Ca²⁺)的关系。结果表明:Ost和钙拮抗剂Ver产生剂量依赖性抑制乙酰胆碱(ACh)、组胺及KCl所致回肠条或结肠带的收缩;非竞争性拮抗CaCl₂累积量—效曲线,pD₂分别为4.41±0.15,7.0±0.2。Ost 100μmol/L和Ver 1μmol/L均能对抗小剂量Ca²⁺所致结肠带收缩,但被加入较大量Ca²⁺所取消。Ost和Ver均能抑制ACh诱导的依内钙性收缩,不影响依外钙性收缩。结果提示Ost具有钙拮抗作用,其作用方式与Ver类似。     

Past use of oral contraceptives and the risk of developing systemic lupus erythematosus

Objective. To examine the relationship between past use of oral contraceptives (OCs) and development of systemic lupus erythematosus (SLE). Methods. Prospective cohort study of 121,645 women who were followed up every 2 years between 1976 and 1990 as part of the Nurses' Health Study. Women were classified as never users or past users of OCs based on self-report. Incidence of SLE was defined by 1) strict American College of Rheumatology (ACR) classification criteria (⩾4 ACR criteria), 2) ⩾4 ACR criteria and any physician's diagnosis, 3) ⩾4 ACR criteria and diagnosis by an ACR-certified rheumatologist, 4) ⩾3 ACR criteria, or 5) diagnosis by a physician even if the patient did not meet the ACR criteria. Results. Compared with never users of OCs, and after adjusting for age and ever use of postmenopausal hormones, the relative risk (95% confidence interval [95% CI]) for the incidence of SLE in the women who had definite cases of SLE (⩾4 ACR criteria) (n = 99) was 1.4 (0.9–2.1) for past users of OCs. Using the most stringent case definition (ACR criteria plus a diagnosis of SLE by an ACR member) (n = 58), the relative risk for past users compared with never users was 1.9 (95% CI 1.1–3.3). No relationship was observed between duration of OC use or time since first use and the risk of developing SLE. Conclusion. Past use of OCs was associated with a slightly increased risk of developing SLE. The decision to use hormonal contraception must be individualized, but the small absolute risk observed for the development of SLE in white women should not be a dominant factor in the decision.