四川轮环藤根中两种新双苄基异喹啉生物碱的分离鉴定

从中国特有植物四川轮环藤(Cyclea sutchuenensis Gagnep.)根中除分得已知的轮环藤碱(Ⅰ)和异粒枝碱(Ⅱ)外,还分离得到两种新双苄基异喹啉生物碱,分别命名为异轮环藤碱(Ⅲ)和四川轮环藤辛碱(Ⅳ)。经物理常数和波谱数据分析鉴定,证明Ⅲ为轮环藤碱的差向异构体,Ⅳ系一种新型的8-12′,12-7′首尾双氧桥双苄基异喹啉生物碱。     

Absolute bioavailability of fluoride from disodium monofluorophosphate and enteric-coated sodium fluoride tablets

Objectives: The absolute bioavailability and other pharmacokinetic parameters of two fluoride formulations were investigated in 13 healthy volunteers, aged 61–70 years. Methods: The following formulations were administered, under fasting conditions, in a single-dose three-way cross-over design: tablets of 76 mg disodium monofluoro phosphate (MFP, equivalent to 10.0 mg F⁻ ion), enteric-coated (e.c.) tablets of 25 mg sodium fluoride (NaF_or, equivalent of 11.3 mg F⁻ ion), and an isoosmotic aqueous injection solution (4 ml) of 22.1 mg sodium fluoride (NaF_iv, equivalent of 10.0 mg F⁻ ion). There was a wash-out period of at least one week between each administration. Blood was sampled before and during a 24-hour period after administration. For F⁻ excretion urine was sampled 48 hours before (baseline) and over the 48 hours after the adminstration. Results: The mean t_1/2 values of the three formulations were 8.3, 8.7 and 8.3 h for MFP, NaF_or and NaF_iv respectively, and were not significant different. Mean C_max after MFP was significantly higher than after NaF_or [344 vs 142 μg⋅l⁻¹]. Mean t_max for MFP was shorter than for NaF_or [1.1 vs 4.6 h]. MFP had significantly higher bioavailability [102.8%] than NaF_or [64.2%]. Conclusion: The MFP formulation showed higher bioavailability with smaller variation than the NaF_or formulation. MFP is preferable, therefore, for fluoride therapy in clinical practice, and changing from NaF_or to MFP will require adjustment of the dose. Received: 23 May 1995/Accepted in revised form: 8 January 1996     

Normal penile anatomy and abnormal penile conditions: evaluation with MR imaging

The appearance of the normal penis and of a variety of penile abnormalities on magnetic resonance (MR) images was studied in 55 patients with either medium (0.35 T) or high (1.5 T) magnetic field strengths. Penile morphologic characteristics with anatomic detail of the corpora cavernosa and corpus spongiosum were demonstrated in each patient. MR images clearly displayed congenital anomalies (n = 6), penile prostheses (n = 7), fibrous tissue or hematoma due to trauma (n = 8), and fibrous plaque in Peyronie disease (n = 3). MR imaging also demonstrated urethral (n = 6) and penile (n = 5) neoplasms and allowed tumor staging, thus facilitating the surgical approach.     

Gated cardiac magnetic resonance structural imaging: optimization by electronic axial rotation

Most magnetic resonance imaging has used body orthogonal axes with the Z axis placed along the length of the body and the X and Y axes at right angles to the body. This orientation is not optimum for the heart; visualization of sections along the short and long cardiac axes would best define cardiac structural detail and functional status. The new orientation was accomplished by selection of electronic angulation of the magnetic fields for each subject rather than by attempting to approximate the cardiac axes by altering the position of the patient. This technique improved visualization of comparative wall segments, valvular structures, and the true four-chamber view of the heart, and also gave the best visualization of the pericardium. In addition, more accurate estimates of chamber size and myocardial mass can be made from the short-axis orientation, since the sections are orthogonal to the myocardium.