Influence of sinus impulses on the parasystolic cycle length

Recently, it has been shown that in most clinical cases of parasystole, the parasystolic rhythm is not completely independent of the sinus rhythm. In this study, to disclose the mechanism of such "irregular" parasystole, parasystolic cycles with an intervening sinus QRS complex (XSX) were compared with their immediately adjacent pure parasystolic cycles without any intervening nonparasystolic QRS complexes (XX) in 10 cases of ventricular parasystole. In eight cases, the XSX interval was equal to or nearly equal to the adjacent pure XX interval; in one, the XSX interval was shorter than the XX interval; and in only one, the XSX interval was longer than the XX interval. In six cases in which the XSX interval was almost equal to the XX interval, calculated XSX intervals with a later intervening sinus QRS complex were obtained from the differences between the XSSX interval (ie, interectopic interval with two intervening sinus QRS complexes) and its adjacent XX interval. In five of the six cases, the calculated XSX interval was shorter than the XX interval. These observations suggest that in most cases of parasystole, early intervening sinus impulses do not change the parasystolic cycle, whereas late intervening sinus impulses shorten the parasystolic cycle. This suggests the presence of type I second-degree entrance block as the mechanism of "irregular" parasystole.     

Oxygen uptake-heart rate relationship in élite wheelchair racers

The American College of Sports Medicine (ACSM) recommends that, as a general rule for health purposes, individuals should exercise at 40%–85% of their maximal oxygen uptakes. Moreover, it has been suggested that 55%–90% of the maximal heart rate may be used as an alternative estimate of these percentage maximal oxygen uptake values. The present study examined the relationship between percentage peak heart rate (% HR_peak) and percentage peak oxygen uptake (% ) during steady-state incremental intensity wheelchair propulsion of 16 élite, male wheelchair racers (WR). Oxygen uptake was determined during each submaximal exercise stage and heart rate (HR) was continuously monitored. The was subsequently determined using a separate protocol. Linear regression equations of % HR_peak versus % for each participant included % HR_peak values corresponding to 40%, 60%, 80% and 85% . The linear regression equation, derived as the group mean of the slope and intercept terms determined for each individual, was: . The group mean of the individual correlation coefficients for the relationship was 0.99. The values of % HR_peak for each of the % values below 85% were significantly greater (P<0.01) than those suggested by the ACSM. This suggests that the ACSM guidelines below 85% , based on % HR_peak, may underestimate the relative exercise intensity (i.e. % ) in the WR population. However, in élite level WR, % HR_peak can be recommended as an alternative estimate of % at wheelchair propulsion intensities of 85% or more. Electronic Publication     

The meaning of good sleep: a longitudinal study of polysomnography and subjective sleep quality

SUMMARY  The present study sought to investigate the meaning of subjectively good sleep, using a longitudinal and intraindividual design. Eight subjects slept in an isolation unit according to an irregular schedule of 6h sleeps and 1h naps, designed to give normal amounts of time in bed (1/3 of total), but variable sleep quality. Eight sleeps and eight naps were used for longitudinal simple and multiple regression analyses with standard polysomnographical sleep variables as predictors and subjective sleep quality as dependent variables. The results showed that subjective sleep quality (and related variables) was closely related to sleep efficiency, but not sleep stages. At least 87% efficiency was required for ratings of 'rather good' sleep. In addition, sleep quality ratings improved with closeness (of the awakening) to the circadian acrophase (17.00–21.00 hours) of the rectal temperature rhythm. The subjective ease of awakening differed from most other other variables in that it was related to low sleep efficiency. Objective and subjective homologues of sleep length and sleep latency showed high mean intraindividual correlations ( r = 0.55 and 0.64, respectively). It was concluded that objective measures of sleep continuity were closely reflected in perceived sleep quality and that sleep quality essentially means sleep continuity.     

益精养血方对帕金森病大鼠多巴胺能神经元Caspase-3表达的影响

目的研究益精养血方对帕金森病(Parkinson's disease,PD)大鼠多巴胺能神经元Caspase-3表达的影响。方法将微量6-羟多巴胺(6-OHDA)立体定向注射于SD大鼠中脑右侧黑质以建立大鼠帕金森病模型,将造模成功的实验动物随机分为模型组、实验(中药)组,每组6只;另纳入6只正常大鼠为正常组。正常组和模型组大鼠生理盐水灌胃,实验组大鼠益精养血方灌胃,各30天。灌胃结束两周后进行行为学检测,免疫组织化学方法观测黑质酪氨酸羟化酶(TH)、Caspase-3的表达。结果实验组大鼠的旋转圈数比治疗前明显减少(P<0.05),实验组损毁侧与健侧黑质TH阳性细胞数量百分比较模型组显著提高(P<0.05),实验组损毁侧黑质Caspase-3表达的OD值比模型组显著降低(P<0.05)。结论益精养血方可使帕金森病大鼠多巴胺能神经元Caspase-3的表达降低,明显抑制神经细胞凋亡。     

Superior cycle control with a contraceptive vaginal ring compared with an oral contraceptive containing 30 microg ethinylestradiol and 150 microg levonorgestrel: a randomized trial

BACKGROUND: This trial was conducted to compare cycle control with vaginal ring a combined contraceptive vaginal ring, and a combined oral contraceptive (COC) delivering 30 mug ethinylestradiol (EE) and 150 mug levonorgestrel. METHODS: This open-label, randomized, multi-centre, Phase III study involved adult women from 11 countries. Subjects were treated with either vaginal ring or a COC for 13 cycles (12 months). RESULTS: A total of 1030 subjects (vaginal ring, n=512; COC, n=518) comprised the intention-to-treat (ITT) population. The percentage of women in the ITT population who completed the trial was 70.9% for vaginal ring and 71.2% for the COC group. The incidence of breakthrough bleeding and spotting over cycles 2-13, the primary efficacy parameter, was lower with vaginal ring (range 2.0-6.4%) than the COC (range 3.5-12.6%), and for cycles 2 and 9 the lower incidence with vaginal ring was confirmed as statistically significant (P=0.003 and P=0.002 respectively). The incidence of intended bleeding was significantly higher over all cycles with vaginal ring (58.8-72.8%) than with the COC (43.4-57.9%). CONCLUSIONS: Cycle control with vaginal ring was excellent and superior to that of a COC containing 30 mug EE.     

The role of a raphe serotonin system in the control of septal unit activity and hippocampal desynchronization.

The effects of electrical stimulation of the median raphe nucleus on neuronal discharges in the medial septal area and electrical activity of the hippocampus were examined in urethane-anaesthetized rats. Two cell populations in the medial septal area were differentiated on the basis of their spontaneous discharge pattern, response to median raphe nucleus stimulation and whether or not they were antidromically activated following hippocampal stimulation. Medial septal area cells classified as I-neurones discharge in an irregular pattern which was unrelated to hippocampal activity. In contrast, B-neurones discharge in either rhythmic bursts or in an irregular manner which were related to hippocampal ‘theta’ or ‘desynchronization’, respectively. Single pulse stimulation of the median raphe nucleus inhibited the spontaneous discharge of I-neurones but did not influence the firing of B-neurones or hippocampal activity. Repetitive stimulation of the median raphe nucleus resulted in a prolonged inhibition of I-neurones, a disruption of the bursting discharge of B-neurones, and desynchronization of the hippocampal ‘theta’. The effects of median raphe nucleus stimulation were blocked by pretreatment with parachlorophenylalanine suggesting that a serotonin-containing system originating in the median raphe nucleus may be involved in mediating these responses.     

基于古今文献对经典名方中细辛毒性的有效避减探析

目的：通过研究细辛的相关文献,对影响细辛毒性的关键信息进行梳理,为经典名方中细辛的合理应用提供依据。方法：通过文献计量学的方式,搜集细辛的古今相关文献,分析细辛毒性与药物基原、用药部位、炮制方式、药物剂型、方药配伍、服药方法及患者体质因素之间的关系。结果：在经典名方的研发过程中,细辛在当归四逆汤、厚朴麻黄汤中的用量分别为9、6 g,煎煮时间应>120 min;细辛在辛夷散、三痹汤、大秦艽汤、清上蠲痛汤种的单次用量分别为0.8、1.2、0.9、1.1 g;当归四逆汤、厚朴麻黄汤、清上蠲痛汤等应选用辽细辛的根茎,辛夷散可选择汉城细辛的根茎。在药物的炮制上,当归四逆汤、厚朴麻黄汤、三痹汤、大秦艽汤四方中的细辛可选用酒制;辛夷散、清上蠲痛汤中的细辛可选用炒制;另外,细辛的毒性与药物的配伍和患者的体质等因素均有着密切的关系。结论：该研究通过梳理有关细辛毒性的文献资料,得出了影响细辛毒性的关键信息,探析了细辛毒性的有效避减方式,为包含细辛的经典名方的合理开发和安全应用提供了更为充分的依据。     

经典名方当归补血汤的古代文献分析与考证

当归补血汤出自金元时期李东垣《内外伤辨惑论卷中·暑伤胃气论》,是一首被历代医家传承发扬的补气生血经典名方,已被收录于2018年国家中医药管理局公布《古代经典名方目录（第一批）》。通过系统梳理古籍文献及现代文献,并结合古代经典名方关键信息考证原则,对经典名方当归补血汤的历史源流、组成、剂量、炮制、制法与煎服法、功效与应用进行考证分析。共收集相关古籍文献信息604条,其中涉及中医古籍186部,其中40部（金元5部,明19部,清16部）中医古籍详细记载了组成、炮制、剂量等内容。有关当归补血汤组成,主要为当归和黄芪;根据古今剂量折算,黄芪37.3~38.1 g,当归7.5~7.6 g;黄芪宜采用蜜炙,当归为酒当归;加入水600 mL,煎至300 mL,饭前温服。该方古籍主要记载功效为血虚发热,证见肌热、燥热,烦渴引饮,目赤面红,昼夜不息,脉洪大而虚,重按无力,是补气生血名方。现代研究表明,当归补血汤常用于治疗各种贫血、糖尿病肾病、肿瘤、心脑血管疾病。上述研究结果为经典名方当归补血汤后期开发研究提供了参考依据。     

补肾生血方联合西药治疗再生障碍性贫血早期疗效预测指标

目的：探讨补肾生血方联合西药治疗再生障碍性贫血（AA）早期疗效的预测指标,为中医补肾治法联合西药治疗AA提供预后参考指标。方法：本研究为回顾性研究,选取2018年9月至2021年3月于中国中医科学院西苑医院等19家医院就诊并采用补肾生血方联合西药治疗6个月有效的126例患者,评价其治疗4个月时的疗效,根据治疗4个月时的疗效评价结果将其分为4个月有效组和4个月无效组,分析比较两组患者治疗前在年龄、性别、疾病分型[包括重型AA(SAA)、非重型AA(NSAA)]、病程、骨髓有核细胞增生程度及基线血象水平[包括白细胞（WBC）、中性粒细胞（ANC）、血红蛋白（HGB）、血小板（PLT）、网织红细胞（RET）]、T淋巴细胞及亚群、T-box转录因子（T-bet）、GATA家族转录因子-3(GATA-3)表达水平指标上的差异。结果：4个月有效组在20岁≤年龄<40岁及60岁≤年龄<80岁患者占比较高（P<0.05）;两组患者在性别、疾病分型（SAA/NSAA）、病程、有无合并症等方面均差异无统计学意义。4个月有效患者治疗前HGB、WBC、ANC、PLT基线水平明显高于治疗4个月...     

益气活血通便方对慢传输型便秘大鼠的治疗作用及机制

目的：探讨益气活血通便方对慢传输型便秘(STC)大鼠的治疗作用及机制。方法：采用盐酸洛哌丁胺灌胃法建立STC大鼠模型,设定正常组、模型组、莫沙必利组、益气活血通便方低、中、高剂量组(3.51、7.02、14.04 g·kg^-1)给药后观察各组大鼠一般体征变化、计算粪便含水率及肠道推进率;采用苏木素-伊红染色观察结肠组织黏膜炎症改变;采用酶联免疫吸附测定法检测各组大鼠结肠P物质(SP)、血管活性肠肽(VIP)含量;采用免疫组织化学法和蛋白免疫印迹法检测大鼠结肠组织水通道蛋白(AQP)3、AQP4、AQP8和c-Kit蛋白灰度值,通过16S r RNA高通量测序检测肠道菌群变化。结果：经过益气活血通便方给药治疗10 d后,与模型组比较,益气活血通便方不同剂量组和莫沙必利组大鼠的粪便含水率和肠道推进率均显著增加(P<0.01)。与模型组比较,益气活血通便方中、高剂量组和莫沙必利组大鼠结肠无明显黏膜炎症改变,杯状细胞排列较规整无断裂、数量较多。益气活血通便方中、高剂量组和莫沙必利组血清中SP含量明显升高(P<0.05,P<0.01),VIP明显降低(P&...