Nonlinear broad band dynamics are less complex in major depression

OBJECTIVES: Cardiac mortality is known to be increased in depressive patients. However, the underlying mechanisms remain elusive to date. Decreased heart rate variability (HRV) has been discussed as contributing to increased cardiac mortality, but studies examining patients suffering from major depressive disorder (MDD) have revealed inconsistent results. This study aimed to investigate long-term and broad band parameters of heart rate regulation in MDD, which have been shown to be more sensitive for the assessment of autonomic dysfunction. METHODS: A total of 18 non-medicated patients suffering from MDD and 18 matched control subjects without cardiac disease were recruited and 24-h ambulatory electrocardiograms were recorded. Data were recorded during three distinct time intervals linear and nonlinear parameters as well as autonomic information flow (AIF) were calculated. RESULTS: The power law slope was significantly reduced in the patient group for all intervals investigated and correlated with symptom severity, whereas standard deviation of the 5-min NN intervals (SDANN) and area under the AIF curve (INT(NN)) showed significant differences between groups in the morning hours only. Analysis of standard HRV parameters in the time and frequency domain revealed no significant differences between groups. CONCLUSIONS: The evidence for decreased complexity of cardiac regulation in depressed patients presented here might be useful as an indicator of the increased cardiac mortality known in depression, especially since these parameters are capable of predicting cardiac mortality in other diseases. The importance of these parameters for patients at risk should be evaluated in future prospective studies.     

盐酸维拉帕米渗透泵片溶出度与人体生物利用度研究

溶出度按Weibull's分布处理得T_d=5.76 h,T₅₀=3.9 h,零级溶出速度常数K_t=9.9450,平均体外溶解时间MDT=5.391 h。测定8名健康受试者,单剂量口服,得C_max=76.2±16.7 ng/ml,T_amx=8.0 h,t_1/2=9.75 h,MRT=19.41 h,MAT=5.34 h,与Knoll公司SR片相比,F_rel=101.71%;与市售普通片相比,F_rel=96.16%。多剂量口服,得C_max=121.47±34.5 ng/ml,T_max=7.14 h。按Loo-Riegelman方程处理表明体内外显著相关。理论值与实测值基本相符。     

生物降解型左旋18－甲基炔诺酮微球在大鼠的药代动力学

用放射免疫法研究了左旋１８－甲基炔诺酮（ＬＮＧ）微球和ＬＮＧ微晶在大鼠的药代动力学。大鼠单次ｉｍＬＮＧ微晶３５ｍｇ·ｋｇ－１后４．８８ｈ．血药峰值达６７．６６ｎｍｏｌ·Ｌ－１，ＭＲＴ为１０．１６ｄ，Ｔ＜０．３２ｎｍｏｌ·Ｌ－１为４１．５０ｄ；而单次ｉｍＬＮＧ微球２０．４，４１．１和８３．３ｍｇ·ｋｇ－１后，血药分别于６，４．６７和４．３３ｈ达峰浓度１５．１９，３３．６１和３８．５５ｎｍｏｌ·Ｌ－１，ＭＲＴ分别为６９．２３，６５．１２和６３．２５ｄ，Ｔ＜０．３ｎｍｏｌ·Ｌ－１分别为１６７．８１，１６９．７３和１６７．２３ｄ。可见ＬＮＧ微球在大鼠的ＭＲＴ和Ｔ＜０．３２ｎｍｏｌ·Ｌ－１分别约为ＬＮＧ微晶的６．６和４．２倍，提示该微球具有明显的缓释长效作用，且初始血药峰值明显低于肌注ＬＮＧ微晶。