输卵管妊娠腹腔镜下手术后持续性异位妊娠的预防

目的:探讨预防腹腔镜下保守性手术治疗输卵管妊娠后持续性异位妊娠(PEP)所需的MTX的治疗剂量.方法:对104例输卵管妊娠患者行腹腔镜下保守性手术,在取出妊娠物后,53例在病灶局部注入MTX 30mg(稀释成2ml),51例局部注入MTX 15mg(稀释成2ml).结果:两组无1例发生PEP,统计学上无显著性差异(P>0.05).结论:用MTX15mg局部注射即能成功地预防腹腔镜下保守性手术治疗输卵管妊娠后PEP的发生,因剂量小,故副作用少,安全有效.     

中西医结合治疗79例宫外孕临床观察

目的:探讨中西医结合治疗宫外孕的有效方法。方法:连续5天,每日肌肉注射氨甲喋啶(ATX)20mg;配合活血止血、消杀胚中药,每天1剂,连服20~25天。结果:79例经20~25天治疗,显效72例,有效7例。结论:中西医结合是一种安全、经济、有效的治疗宫外孕方法。     

Activation by reduced glutathione of methotrexate transport into isolated rat liver cells

The uptake of methotrexate (MTX) by isolated rat hepatocytes and its changes under the influence of exogenous GSH have been studied under various conditions: GSH concentration, pH of incubation medium, preincubation of cells prior to MTX and GSH addition, ionic composition of the incubation medium (standard saline, Na⁺-free, Na⁺ and K⁺-free, or ion-deficient), after prior treatment of cells by membrane -SH blockers (p-CMBS, 4-CMB and DIP²⁺) and ATP.It was found that GSH strongly accelerated MTX uptake. This effect depended on GSH concentration and on preincubation of cells. The GSH effect was not dependent on medium pH in spite of an observed close relationship between pH of incubate and MTX transport itself. Activation by GSH of MTX transport was connected to an increase in intracellular K⁺. It was also noted that while blockers of membrane -SH groups like p-CMBS and 4-CMB inhibited MTX uptake and increased the intracellular Na⁺/K⁺ ratio, both effects were partially overcome by GSH. After treatment by DIP²⁺, Na⁺/K⁺ ratio was unaffected, but MTX uptake inhibited. Still GSH abolished inhibition. Added ATP also inhibited MTX uptake and caused loss of cellular K⁺ and accumulation of Na⁺ Here neither effect could be reversed by GSH; consequently, high cellular amounts of K⁺ and MTX accumulated by previous action of GSH were depleted on subsequent ATP addition. MTX uptake was low in sucrose medium. But in this ion-deficient medium, GSH had the greatest stimulatory effect on MTX uptake.It is concluded that binding GSH can affect the redox state of the -S-S-/-SH groups of the cellular plasma membrane and that this effect of GSH might demonstrate involvement of the redox state in the control of MTX permeability.     

氨甲蝶呤两种给药方法治疗异位妊娠的比较

目的 :寻找简单、有效且成功率高 ,又不影响生育功能的异位妊娠氨甲蝶呤 (MTX)给药方法。方法 :对92例确诊异位妊娠 ,符合 MTX药物治疗条件的患者 ,分成 A、B两组 ,A组 5 8例 ,使用 MTX全身分次注射 ,B组 34例 ,使用 MTX在电视宫腔镜直视下插管单次注射 ,两组进行比较。结果 :治疗成功率、治疗前两组的血β- HCG水平、平均住院日、治疗后输卵管通畅率 ,两组差异无显著性 (P>0 .0 5 ) ,治疗后血 β- HCG恢复正常水平的时间 ,B组优于 A组 (P<0 .0 5 ) ,A组副反应发生例数多于 B组 (P<0 .0 5 )。结论 :两种给药方法治疗异位妊娠 ,均具有安全、有效的优点 ,MTX全身分次注射方法简单、易操作 ,发生副反应轻 ,适用基层医院使用。     

Methotrexate Concentration Levels in the Cerebrospinal Fluid During High-Dose Methotrexate Infusions: An Unreliable Prediction

In 25 children with lymphoid malignancies, 96 high-dose methotrexate infusions (3 g/m²) with a duration of 24 h have been administered as a part of the treatment schedule. A lumbar puncture was performed to apply methotrexate intrathecally. The moment of lumbar puncture during the infusion was chosen at different times. In 76 of the infusions the concentration of methotrexate in the cerebrospinal fluid and in plasma were determined just prior to the intrathecal administration. From the second to the eighth hour after the initiation of the infusion the concentration of methotrexate in the cerebrospinal fluid appeared to be significantly lower than 16 or 24 h after the initiation of the infusion. Of all samples during the infusions, the plasma concentration varied a tenfold (2-20 X 10^-5 mol/L), but the cerebrospinal fluid concentration of methotrexate varied about a 300-fold (3.5-900 X 10 mol/L). No correlation could be found between the plasma concentration of methotrexate and the cerebrospinal fluid concentration. It is concluded that the methotrexate concentration in the cerebrospinal fluid cannot be predicted by determining the plasma concentration. It lakes at least 8 h of infusion before a steady-state concentration of methotrexate is reached in the cerebrospinal fluid. In high-dose methotrexate infusions without intrathecal therapy, the dose of 3 g/m² is the minimum amount of methotrexate to reach the minimum therapeutic concentration 5 X 10⁷ mol/L) in the cerebrospinal fluid for the treatment of subclinical central nervous system invasion of malignant lymphoid cells. To maintain the minimum therapeutic concentration according to the CxT principle the duration of the infusion should be preferably longer than 24 h.     

Pharmacokinetics of methotrexate in erythrocytes in psoriasis

Summary The intraerythrocytic levels of folate and methotrexate were measured in 25 patients on long-term methotrexate therapy for recalcitrant psoriasis. The mean steady state concentration of methotrexate in erythrocytes was 85 nmol/l and the mean erythrocyte folate concentration was 729 nmol/l. A linear correlation was not observed between these parameters, but the greatest methotrexate accumulation was found in cells at the lower end of the erythrocyte folate concentration range. In 5 patients started on methotrexate therapy the erythrocyte concentrations of methotrexate and folate were followed over 6 months. 3–4 days after the first dose, methotrexate had been accumulated against a concentration gradient in the erythrocytes. The methotrexate concentration increased steadily until the steady state level was reached after 4–6 weeks. The steady state level was maintained during the 6 month ovservation period. The erythrocyte folate concentration did not change during this period. The data suggest that methotrexate polyglutamate synthesis whithin the circulating erythrocyte is a major cause of methotrexate accumulation in these cells.     

双突变二氢叶酸还原酶基因对小鼠的化疗保护作用

目的 探讨人双突变的二氢叶酸还原酶（DHFR）基因对小鼠化疗保护作用。方法 以反转录病毒为载体,将DHFR基因转染入小鼠骨髓干细胞,观察氨甲喋呤（MTX）处理后的骨髓细胞中粒细胞-巨噬细胞克隆形成单位（CFU-GM）的生成情况;观察大剂量MTX化疗后转基因小鼠血象、体重及生存率的变化;用RT-PCR检测转基因小鼠骨髓细胞耐药基因的表达。结果 转染SFG-F／S-NeoR耐药基因的骨髓细胞有耐药克隆的形成,供体小鼠为15.8％,受体小鼠为18．0％,对照组为0;大剂量化疗后,含耐药基因组小鼠血象、体重逐渐恢复正常,生存率为83．3％（第40天）,对照组为0;转基因小鼠骨髓细胞经RT-PCR检测,显示有F／S基因条带（400bp）。结论 DHFR耐药基因可导入小鼠骨髓细胞并获得表达,提高了骨髓细胞对MTX的耐药性。     

甲氨喋呤脂质体药物释放动力学研究

本文应用荧光分光光度法研究了甲氨喋呤脂质体冻干粉针在几种输液中药物释放动力学。结果表明:甲氨喋呤脂质体的药物释放速率符合一级动力学方程。甲氨喋呤脂质体在不同输液中药物释放速率常数不同。温度升高、药物释放速率常数增大。     

Azaspiracid-4 inhibits Ca2+ entry by stored operated channels in human T lymphocytes

Azaspiracids (AZs) are a new group of phycotoxins discovered in the Ireland coast that includes the isolated analogues: AZ-1, AZ-2, AZ-3, AZ-4 and AZ-5 and the recently described AZ-6-11. Azaspiracid toxic episodes show gastrointestinal illness, but neurotoxic symptoms are also observed in mouse bioassay. Despite their great importance in human health, so far its mechanism of action is largely unknown. In this report, we present the first data about the effect of AZ-4 on cytosolic calcium concentration [Ca2+]i in freshly human lymphocytes. Cytosolic Ca2+ variations were determined by fluorescence digital imaging microscopy using Fura2 acetoxymethyl ester (Fura2-AM). AZ-4 did not modify cytosolic Ca2+ in resting cells. However, the toxin dose-dependent inhibited the increase in cytosolic Ca2+ levels induced by thapsigargin (Tg). AZ-4 decreased Ca2+-influx induced by Tg but did not affect the Ca2+-release from internal stores induced by this drug. The effects of AZ-4 on Ca2+-influx induced by Tg were reversible and not regulated by adenosine 3',5'-cyclic monophosphate (cAMP) pathway. When AZ-4 was added before, after or together with nickel, an unspecific blocker of Ca2+ channels, the effects were indistinguishable and additive. AZ-4 also inhibited maitotoxin (MTX)-stimulated Ca2+-influx by 5-10%. Thus, AZ-4 appeared to be a novel inhibitor of plasma membrane Ca2+ channels, affecting at least to store operated channels, showing an effect clearly different from other azaspiracid analogues.