大孔树脂富集三裂叶蟛蜞菊倍半萜内酯A和B的研究

目的 大量富集三裂叶蟛蜞菊倍半萜内酯A，B(WTA，WTB)。方法 采用气相色谱法测定WTA和WTB，并以WTA和WTB的含量、洗脱率、精制度为考察指标，研究D101大孔树脂吸附WTA和WTB的工艺条件及参数。结果 通过大孔树脂吸附后，WTA和WTB的洗脱率达90％，50％乙醇洗脱部分中WTA和WTB的含量为总固物的4．01％～4．09％。结论 可以采用大孔树脂富集WTA和WTB。     

The Myocardial Lesions Produced by the Potassium Channel Opener Aprikalim in Monkeys and Rats Are Prevented by Blockade of Cardiac {beta}-Adrenoceptors

Aprikalim is a potent, specific, and selective opener of ATP-sensitiveK⁺ (K_ATP) channels. By virtue of this pharmacological property,aprikalim affords cardioprotection in experimental models ofischemia/reperfusion injury, and, at higher doses, also causesperipheral or coronary vasodilatation. Direct-acting peripheralvasodilators can cause myocardial lesions, particularly in ratsand dogs. However, unexpectedly, aprikalim produced this effectalso in monkeys. Thus, the primary aim of this investigationwas to assess whether in monkeys these myocardial lesions werethe direct or indirect consequence of the vascular effects ofaprikalim. Cyno-mologus monkeys were given the ß-adrenoceptorantagonist nado-lol (2 mg/kg po, twice daily) for 4 consecutivedays. On the third and fourth day of the experiment, they receivedaprikalim (1 mg/kg po). In another series, two monkeys carryingtelemetry transmitters for blood pressure and heart rate measurementswere also given aprikalim or its vehicle. Finally, aprikalim(1 mg/kg po for 2 days) or its vehicle was administered to ratswhich were concurrently treated with the ß-adrenoceptorantagonist atenolol (5 mg/ kg sc) or its vehicle. In cynomologusmonkeys, aprikalim produced focal and multifocal myocardialnecrosis of minimal to moderate intensity in or near the papillarymuscles of the left ventricle. These effects were abrogatedby nadolol. Similarly, necrotic lesions were caused by aprikalimonly in those rats which had not been pretreated with atenolol.In monkeys, aprikalim produced a marked and long-lasting decreasein aortic blood pressure, accompanied by an even more prolongedtachycardia. These results demonstrate that aprikalim can producemyocardial necrosis not only in rats but also in monkeys. Toour knowledge, this is the first time that such adverse effectsare reported for a vasodilator in monkeys. More importantly,these effects were prevented by blocking cardiac ß-adrenoceptors.Thus, the myocardial lesions produced by aprikalim may be attributedto its profound and prolonged hemodynamic effects.     

Variation in the Amount of Hemoglobin S in a Patient with Sickle Cell Trait and Megaloblastic Anemia

A patient with sickle cell trait and nutritional megaloblastic anemia wasfound to have a much smaller proportion of hemoglobin S during the megaloblastic phase than after recovery. This observation suggests preferential synthesis of hemoglobin A by megaloblastic bone marrow in the presence of theA-S trait.

Submitted on July 30, 1962 Accepted on November 9, 1962     

On-call work and sleep: the importance of switching on during a callout and switching off after a call

Due to the unpredictable nature of working time arrangements, on-call workers experience regular disruption to sleep, particularly if woken by calls. Sleep disruption can impact long term physical and mental health, next day performance, and importantly, performance immediately after waking. To reduce the impact of performance impairments upon waking (i.e., reducing sleep inertia), research has investigated strategies to promote alertness (e.g., bright light, caffeine, and exercise). This review puts forth on-call workers who are likely to return to sleep after a call, it is also important to consider the impact of these sleep inertia countermeasures on subsequent sleep. Future research should build on the preliminary evidence base for sleep inertia countermeasures by examining the impact on subsequent sleep. This research is key for both supporting alertness and performance during a call (“switching on”) and for allowing the on-call worker to return to sleep after a call (“switching off”).     

Indications and effects of botulinum toxin A for obstetric brachial plexus injury: a systematic literature review

Aim To give an overview of indications for the use of botulinum toxin A (BoNT‐A) treatment for children with obstetric brachial plexus injury (OBPI), and to present the best available evidence of the effectiveness of this treatment. Method Searches were performed in Cinahl, Cochrane Library, Embase, PubMed, and Web of Science, using the keywords ‘botulinum’ and ‘plexus’, to identify articles reporting on the use of BoNT‐A as a treatment for children with OBPI. Studies found through the references of related articles were also selected. Results Ten full‐text papers and six congress abstracts were included, involving 343 children. Four groups of indications could be identified: internal rotation/adduction contracture of the shoulder, limited active elbow flexion, limited active elbow extension, and pronation contracture of the lower arm. Overall, positive results were reported for all except the indication for limited active elbow extension. However, only one study was comparative in nature; all others were classified as having a low level of evidence. There was a large variation in outcome measures. Interpretation To provide better evidence for the already partly promising results of BoNT‐A treatment for children with OBPI, multicentre randomized controlled trials are needed.     

How does the pitch and pattern of a signal affect auditory arousal thresholds?

How arousal thresholds vary with different sounds is a critical issue for emergency awakenings, especially as sleepers are dying in fires despite having a working smoke alarm. Previous research shows that the current high-pitched (3000+ Hz) smoke alarm signal is significantly less effective than an alternative signal, the 520 Hz square wave, in all populations tested. However, as the number of sounds tested has been small further research is needed. Here we measured auditory arousal thresholds (AATs) across signals with a range of characteristics to determine the most effective waking signal. Thirty-nine young adults participated over three nights. In Part A, nine signals were presented in stage 4 sleep with ascending decibel levels. Signals were short beeps in the low- to mid-frequency range with different spectral complexities: square waves, pure tones, whoops and white noise. Part B manipulated temporal patterns, inserting silences of 0, 10 and 21 s after each 12 s of beeps. It was found that the low-frequency (400 and 520 Hz) square waves yielded significantly lower AATs than the alternatives. A trend was found across the three temporal manipulations, with a 10 s intervening silence showing some advantage. These findings support earlier research indicating that the best sound for awakening from deep sleep is a low-frequency square wave. It is argued that the signal with the lowest response threshold when awake may be the same as the most arousing signal when asleep, especially where the sleeper processes the signal as meaningful.     

Transoral Partial Supraglottic Resection Using The CO2 Laser

Transoral epiglottis resection or partial supraglottic resection was done with the CO₂ laser in 20 highly selected patients. Visualization was best accomplished using the Lynch suspension system, but was satisfactory with the Jako-Pilling laryngoscope. The best indications for this procedure were: 1. for visualization of the true vocal cords in previously treated cancer patients whose epiglottis obstructed indirect mirror examination, 2. for removal of obstructing benign epiglottic lesions, 3. as an excisional biopsy in limited epiglottic cancer, especially of the suprahyoid epiglottis. No major complications or operative morbidity occurred. This approach obviated the potential morbidity of external surgical procedures in a select group of patients. Shortened hospitalization, avoidance of tracheotomy, minimal postoperative discomfort and edema, and excellent wound healing were additional advantages seen.