QuEChERS-超高效液相色谱-质谱联用法测定熊胆粉中9种苯二氮䓬类药物残留量

建立了超高效液相色谱-质谱联用法(UPLC-MS/MS)快速测定中药材熊胆粉中9种苯二氮?类药物残留的方法。样品以乙腈为提取溶剂,经萃取盐包除杂提取,采用分散式固相萃取管 (EMR-Lipid dSPE) 净化,ACQUITY BEH C18色谱柱(1.7 μm,2.1×100 mm)分离,多反应监测模式(MRM)采集数据,外标法定量。在优化的条件下,虽9种药物存在不同程度的基质效应,但不影响检测结果的准确性。方法学考察结果显示,9种苯二氮?类药物在对应的浓度范围内线性关系良好,决定系数(R²)≥0.9961,方法检出限(LOD,S/N =3)在0.06～0.71 μg/kg范围内,定量限(LOQ,S/N =10)在0.20～2.60 μg/kg范围内,3个加标水平的平均回收率在69.1%～108.0%范围内,日内RSD为1.8%～9.0%,日间RSD为2.6%～9.3%。该方法前处理操作简便、重现性好,准确度高,为熊胆粉中苯二氮?类药物残留的风险监控提供了一种有效的检测技术。     

S‐(+)‐Linalool from Lippia alba: sedative and anesthetic for silver catfish (Rhamdia quelen)

ObjectiveThe present study describes the isolation of linalool from the essential oil of Lippia alba (Mill.) N. E. Brown, and its anesthetic effect in silver catfish (Rhamdia quelen) in comparison with essential oil. The potentiation of depressant effects of linalool with a benzodiazepine (BDZ) and the involvement of GABAergic system in its antagonism by flumazenil were also evaluated.Study designProspective experimental study.AnimalsJuvenile silver catfish unknown sex weighing mean 9.24 ± 2.83 g (n = 6 for each experimental group per experiment).MethodsColumn chromatography was used for the isolation of S-(+)-linalool. Fish (n = 6 for each concentration) were transferred to aquaria with linalool (30, 60, and 180 μL L^?1) or EO of L. alba (50, 100, and 300 μL L^?1) to determine the induction time for anesthesia. After induction, the animals were transferred to anesthetic-free aquaria to assess their recovery time. To observe the potentiation, fish were exposed to linalool (30, 60, and 180 μL L^?1) in the presence or absence of BDZ (diazepam 150 μm). In another experiment, fish exposed to linalool (30 and 180 μL L^?1) or BDZ were transferred to an anesthetic-free aquaria containing flumazenil (5 μm) or water to assess recovery time.ResultsLinalool had a similar sedation profile to the essential oil at a proportional concentration in silver catfish. However, the anesthesia profile was different. Potentiation of linalool effect occurred only when tested at low concentration. Fish exposed to BDZ showed faster anesthesia recovery in water with flumazenil, but the same did not occur with linalool.Conclusions and clinical relevanceThe use of linalool as a sedative and anesthetic for silver catfish was effective at 30 and 180 μL L^?1, respectively. The mechanism of action seems not to involve the benzodiazepine site of the GABAergic system.     

Sedative effects of an intramuscular or intranasal combination of sufentanil and midazolam in New Zealand White rabbits

ObjectiveTo evaluate the sedative effects of a combination of sufentanil and midazolam administered intramuscularly (IM) or intranasally (IN) prior to induction of anesthesia with propofol in New Zealand White rabbits.Study designProspective, randomized, crossover, experimental study.AnimalsA total of 11 adult New Zealand White rabbits.MethodsSufentanil (0.5 μg kg^–1) and midazolam (2 mg kg^–1) were administered to rabbits via IM or IN route. The righting reflex was assessed, and sedation was scored. Heart rate, respiratory rate (f_R) and temperature were recorded prior to treatment administration and after loss of the righting reflex.ResultsMeasured variables remained within normal physiologic ranges for all rabbits. The only statistically significant change was for f_R, which was significantly lower after sedation for both routes. The time to loss of righting reflex was 14.8 ± 6.5 and 12.5 ± 7.4 minutes and sedation scores were 6 (4–8) and 7 (6–8) for IM and IN routes, respectively, with no difference between treatments. No adverse effects were observed during the experimental period.Conclusions and clinical relevanceSufentanil combined with midazolam administered either IM or IN resulted in moderate to deep sedation in New Zealand White rabbits at the dose rates studied.     

Effect of benzodiazepines on the dose of alfaxalone needed for endotracheal intubation in healthy dogs

Objective

To evaluate the dose-sparing effect of midazolam or diazepam on the dose of alfaxalone required to achieve endotracheal intubation in premedicated dogs.

Effects of peripheral-type benzodiazepine receptors in platelet membrane on patients with depression after first attack of cerebral infarction

AIM：To evaluate the changes of peripheral-type benzodiazepine receptors (PBRs) in platelet membrane in post-stroke depression (PSD) patients and to investigate the effects of PBRs on PSD. METHODS：Forty-three patients with PSD, fifty-nine patients with first-ever cerebral infarction and fifty-six healthy volunteers participated in this study. Platelet membrane in venous blood was prepared. Binding assay of the radioactive PBRs antagonist ［3H］PK11195 to platelet membrane was performed. RESULTS：A significant difference of ［3H］PK11195 binding was found among the 3 groups (P<0.01). Compared with the healthy volunteers ［(298.2±25.1） pmol/(g protein)］, a highly significant increase in ［3H］PK11195 binding was observed in platelet membrane in the patients with first attack of cerebral infarction ［(1 410.8±41.4） pmol/(g protein), P<0.01］. Compared with the patients with first attack of cerebral infarction, a significant reduction in ［3H］PK11195 binding was detected in platelet membrane in the patients with PSD ［(361.7±30.6) pmol/(g protein), P<0.01］. In the patients with PSD, no significant difference of ［3H］PK11195 binding was found between men and women (P>0.05). ［3H］PK11195 binding was related to the score of Hamilton depression rating scale (r=-0.44, P<0.01) but not to the duration of cerebral infarction (r=0.27,P>0.05). CONCLUSION:PBRs binding activity in platelet membrane decreases in the patients with PSD and affects the degree of depression.     

Evaluation of sedative and antinociceptive effects of dexmedetomidine,midazolam and dexmedetomidine–midazolam in tegus (Salvator merianae)

Objective

To evaluate dexmedetomidine, midazolam and dexmedetomidine–midazolam for sedation and antinociception in tegus.