苯甲吗啉类药物的代谢及代谢产物的研究

本文报道苯甲吗啉类药物的气相色谱与气质联用检测方法。用HP-5890A气相色谱仪、氮专属性检测器,对服药后不同时间排尿中原型药及主要代谢产物,以内标法定量测定,绘制尿累积排泄曲线.醚提取物用三氟醋酐衍生化、气相色谱、气质联用分析比较衍生化前后保留时间及质谱数据,鉴定主要代谢产物苯甲吗啉,微量代谢产物去甲麻黄素、去甲伪麻黄素、麻黄素和伪麻黄素,方法灵敏、结果可靠,适用于此类药物的临床监测与运动员尿样检测。     

Pentastarch Versus Albumin in Cardiopulmonary Bypass Prime: Impact on Blood Loss

Abstract Background: Albumin is commonly used as a volume expander in cardiopulmonary bypass (CPB) prime. Pentastarch, a low molecular weight hetastarch, may provide similar efficacy at decreased cost but is known to alter coagulation profiles. Infectious concerns forced the temporary withdrawal of albumin in our institution. Therefore we evaluated pentastarch as an alternative with regards to perioperative hemostasis and blood loss. Methods: One hundred consecutive adult patients undergoing first-time aorto-coronary bypass were given 750 mL of 10% pentastarch (represented as P in calculations) diluted in 1000 mL of Ringer's solution added in their CPB prime. A similar control group of 100 consecutive patients had received 200 mL of 25% albumin (represented as A in calculations) diluted in 1500 mL of Ringer's solution. Results: Postoperative prothrombin time (PT) was slightly higher with pentastarch (P: 14.9 ± 1.5 seconds, A: 14.2 ± 1.3 seconds, p = 0.003). Postoperative bleeding was also increased (P: 2337 ± 1242 mL, A: 1981 ± 1121 mL, p = 0.0341, mostly because of recirculated shed mediastinal blood (P: 834 ± 499 mL, A: 640 ± 388, p = 0.002) rather than lost pleural tube blood (P: 1503 ± 821 mL, A: 1341 ± 824 mL, p = 0.16). Overall net blood loss (P: 2014 ± 914 mL, A: 2061 ± 1015, p = 0.73) was similar. Blood-product transfusion requirements and postoperative daily hematocrits did not differ. Conclusion: The diminished coagulability associated with this dose of pentastarch resulted in increased postoperative bleeding. However, with recirculation of shed mediastinal blood, there was no net increase in blood loss. In this setting, pentastarch may serve as a suitable alternative to albumin. ( J Card Surg 1999; 14.279–286 )     

Cerebrospinal fluid analyses in migraine patients and controls

To investigate the role of central neurotransmitters in the pathogenesis of migraine, we measured cerebrospinal fluid (CSF) levels of certain amino acids (glycine, taurine, glutamine) and metabolites of biogenic amines (5-hydroxyindoleacetic acid and homovanillic acid) in 38 migraine patients and compared them with the levels from 10 headache-free controls. The levels of taurine, glycine and glutamine were significantly higher in the migraine patients (p < 0.0001 for taurine and glycine; p < 0.0009 for glutamine); there were no significant differences among the three migraine subgroups (infrequent migraine, frequent migraine and transformed migraine). In seven patients subsequently treated with divalproex sodium, CSF taurine levels decreased significantly from pretreatment baseline values. These data support the concept that migraine is at least in part a disorder of central neurotransmission.     

Plaque accumulation on different dental filling materials

abstract — The purpose of the present study was to investigate whether some dental filling materials collect more plaque than others under standardized conditions in vitro and in vivo . Round disks of the filling materials of silicate, composite and amalgam were prepared and placed on an agar/sucrose medium or hung in liquid medium containing 5% sucrose. The mediae were inoculated with Streptococcus mutans OMZ 176 and OMZ 52–3. After 6 d the disks were rinsed in distilled water and the plaque that had accumulated on the surfaces was scraped off and measured by the orcinol method. The materials were also fitted to acrylic plates and introduced into the mouth. Six patients wore two plates each for comparison of the materials and were told to rinse their mouth every hour with 15% sucrose solution. After 8 h the plaque was scraped off and measured. Silicate disks on agar medium invariably produced inhibition zones of about 4 mm. Composites and amalgam showed no such zones. In liquid medium an insignificant amount of plaque was absorbed to the silicate disks, whereas abundant amounts were found on composite materials and some on amalgam disks. The same trend could be demonstrated in the clinical experiments.     

Endoscopic third ventriculostomy: a study of intracranial pressure vs. haemodynamic changes.

Fourteen paediatric patients with obstructive hydrocephalus were studied. They underwent endoscopic third ventriculostomy under general anaesthesia. Their ages ranged from 1 to 144 weeks (mean 34+/-36 weeks) and weight from 2 to 22 kg (mean 10.2+/-5.4 kg). In an attempt to identify the possible mechanisms of the intraoperative haemodynamic changes associated with endoscopic third ventriculostomy, we studied the intracranial pressure measured in the third ventricle versus the haemodynamic changes. The intracranial pressure was measured using a pressure transducer attached at one end to the endoscope and the other end to the monitor. The mean third ventricle pressure value was 10.2 mmHg (+/-3.5). Bradycardia occurred in six (43%) of our patients. The mean value of the lowest heart rate reading intraoperatively was 81 beats/min (+/-31.8). Negative correlation was obtained between the intracranial pressure and the haemodynamic changes. Alerting the surgeon to perforate the floor of the third ventricle or withdraw the scope away from it was sufficient to resolve the bradycardia. We concluded that serious dysrhythmias might occur during endoscopic third ventriculostomy, the majority of which can be resolved without medications.