体位改变对Beagle犬心脏自主神经控制的影响

目的观察体位改变对Beagle犬心脏自主神经控制的影响。方法利用大动物无创生理遥测技术,监测清醒活动状态下雌性Beagle犬在静态姿势（lying、standing、sitting、hanging）和运动（walking）姿势下的心电图（ECG）,并用HRV功率谱分析其自主神经功能。结果在静态姿势下,Beagle犬RR间期（RRI）、RR间期的标准差SDNN（SDNN）、相邻RR间期差值平方和的均方根RMSSD（RMSSD）、相邻R-R间期差值〉50 ms的窦性个数占心搏总数的百分比pNNabs（50）（pNNabs（50））、TP总功率（TP）、VLF极低频功率（VLF）、标准化高频功率（HFnorm）均明显高于运动状态（P〈0.05,P〈0.01）,而心率（HR）、标准化低频功率（LFnorm）和低频功率/高频功率（LF/HF）平衡指数则明显低于运动状态（P〈0.05,P〈0.01）。结论不同体位姿势在静息状态下以迷走神经活动兴奋为主,相反,在运动状态下以交感神经活动兴奋为主;体位姿势改变能引起心率的变化,必然影响心脏自主神经控制能力,其主要取决于迷走神经活动强弱有关,且导致LF/HF均衡性的破坏。     

心肺压力感受器持续卸荷对前臂血流、血管阻力及心率变异性谱的影响

低压值下体负压（ＬＢＮＰ）可仅使心肺压力感受器卸荷。采用－２ｋＰａＬＢＮＰ实验结果表明：ＬＢＮＰ既不引起动脉血压变化,也不引起心率改变,但却引起基础胸阻抗（Ｚ。）从对照的２１．８±０．４升高到２２．５±０．５Ω（Ｐ＜０．０１）,前臂血管阻力（ＦＶＲ）从１２．３±０．９升高到１９．９±１．４Ｕ（Ｐ＜０．０１）,前臂血流（ＦＢＦ）从对照时７．１±０．５降低到４．３±０．３ｍｌ·ｍｉｎ￣（－１）·１００ｍｌ￣（－１）,心率变异性谱（ＨＲＶ）未发生任何变化,即心肺压力感受器卸荷时心脏自主神经活动水平与均衡性不受影响。由于ＦＶＲ和ＦＢＦ的变化可间接反映外周血管交感传出活动水平,上述实验结果提示,心肺压力感受器对外周血管及心脏自主神经活动的调节可能存在机能分化现象。     

风电项目对潜在生态廊道的影响——基于MSPA-MCR模型

风电作为构建新型电力系统的主体,能够有效助力电力系统脱碳,是实现“双碳”目标的主力军。但风电规模化建设与生态环境保护之间的矛盾日益突出,风电项目对生态环境,尤其是对区域生态廊道及生态安全格局的影响急需厘清。以福建平潭陆上风电项目所在区域为研究单元,运用形态学空间格局分析法和最小累积阻力模型、重力模型等判别重要生态源地及潜在生态廊道,评估风电项目对潜在生态廊道连通性、重要性和结构性等影响。研究表明：(1)研究区生态源地主要位于生态价值高的森林公园及风景名胜区内。受风电项目影响,源地呈现破碎化趋势,核心区占景观要素百分比由79.53%下降至76.64%。(2)风电项目导致生态廊道畅通性降低,生态廊道的走向及长度发生显著变化,大大增加了生物迁徙的空间阻力。(3)风电项目弱化了生态源地之间关联性。核心廊道和次级廊道均减少了6条,且重要性强的生态廊道完全避开风电项目所在位置。风电项目建设之后生态网络流通性变差,网络更为单一、整体生态效能降低。本研究不仅从生态环境敏感脆弱区域的生态安全角度给风电项目建成区周边生态修复提供科学参考,也为未来风电项目选址及环境质量评估提供了重要的方法支撑。     

基于多水文改变指标评价东江流域河流流态变化及其对生物多样性的影响

新丰江、枫树坝和白盆珠3座大型水库的建立对东江流域河道流量和河流流态过程有了较大改变,威胁河道下游生态系统的健康。基于广义指标生态剩余和生态赤字评价了东江流域受水库影响后流域生态需水需求目标总的盈余和缺失变化过程,基于IHA32指标计算的Do和DHRAM评价了水库对下游河段河流水文过程总的改变程度以及威胁河道生态系统健康的风险性大小,并进一步分析了对河道生物多样性的影响。研究结果如下:(1)水库对流量历时曲线(FDC)有显著影响,曲线上部下降,尾部上升,尤其体现在秋季和冬季。降水对年与夏季生态剩余影响较大,水库对各季节生态剩余和生态赤字均有较大影响:秋季和冬季生态赤字几乎为0,生态剩余显著增加。生态剩余和生态赤字与大部分IHA中32个指标具有很强的相关性,可作为衡量东江流域年和季节径流变化的生态指标。(2)龙川、河源、岭下和博罗4站点总体改变程度分别为58.48%、54.04%、54.32%和52.47%。河流流态变化导致总季节生态剩余增加并维持在较高水平,进一步引起河流生物多样性下降,并维持在较低水平。龙川和河源两站河流流态的变化对河流生态系统造成了高风险性影响,岭下和博罗两站则为中等风险。     

The Effects of a Therapy Dog on the Blood Pressure and Heart Rate of Older Residents in a Nursing Home

The aim of the present project was to investigate whether repeated visits by a therapy dog to nursing homes might affect the older residents’ systolic blood pressure and heart rate. A secondary aim was to investigate and compare effects (differences in responses) in older people with high and normal systolic blood pressure. The project consisted of two consecutive studies; the dog study (two researchers and a therapy dog with a handler visited the residents at three nursing homes, n = 13), and the control study (the two researchers alone visited the residents at three different nursing homes, n = 13). The studies were divided into three periods; period 1 (weeks 1–2), period 2 (weeks 3–4), and period 3 (weeks 5–6) and included two visits per week. The dog and her handler visited during periods 2 and 3 in the dog study. Participants’ heart rate and blood pressure were measured at 0 and 20 minutes at each visit. The data were analyzed using Friedman's two- way analysis of Variance by Rank with post-hoc analysis using Wilcoxon signed-rank tests with a Bonferroni correction, and also with the Mann-Whitney U test for independent samples. In the dog study, participants’ heart rate decreased significantly (p = 0.006) from period 1 to period 3. Participants with an initial systolic blood pressure ≥ 130 mmHg had a significant decrease in both systolic blood pressure (p = 0.009) and heart rate (p = 0.009). In the control study, participants’ heart rate and systolic blood pressure did not change significantly. The participants in the dog study had a significantly lower systolic blood pressure during period 3 (p = 0.016) compared with those in the control study. In conclusion, repeated visits by a therapy dog–handler team decreased the older adults’ heart rate, and for those with high initial systolic blood pressure, blood pressure also decreased. In addition, systolic blood pressure decreased significantly in the dog group when compared with the control group.     

Administration-Time Differences in Effects of Hypertension Medications on Ambulatory Blood Pressure Regulation

Specific features of the 24-h blood pressure (BP) pattern are linked to progressive injury of target tissues and risk of cardiovascular disease (CVD) events. Several studies have consistently shown an association between blunted asleep BP decline and risk of fatal and nonfatal CVD events. Thus, there is growing focus on ways to properly control BP during nighttime sleep as well as during daytime activity. One strategy, termed chronotherapy, entails the timing of hypertension medications to endogenous circadian rhythm determinants of the 24-h BP pattern. Significant and clinically meaningful treatment-time differences in the beneficial and/or adverse effects of at least six different classes of hypertension medications, and their combinations, are now known. Generally, calcium channel blockers (CCBs) are more effective with bedtime than morning dosing, and for dihydropyridine derivatives bedtime dosing significantly reduces risk of peripheral edema. The renin-angiotensin-aldosterone system is highly circadian rhythmic and activates during nighttime sleep. Accordingly, evening/bedtime ingestion of the angiotensin-converting enzyme inhibitors (ACEIs) benazepril, captopril, enalapril, lisinopril, perindopril, quinapril, ramipril, spirapril, trandolapril, and zofenopril exerts more marked effect on the asleep than awake systolic (SBP) and diastolic (DBP) BP means. Likewise, the bedtime, in comparison with morning, ingestion schedule of the angiotensin-II receptor blockers (ARBs irbesartan, olmesartan, telmisartan, and valsartan exerts greater therapeutic effect on asleep BP, plus significant increase in the sleep-time relative BP decline, with the additional benefit, independent of drug terminal half-life, of converting the 24-h BP profile into a more normal dipping pattern. This is the case also for the bedtime versus upon-awakening regimen of combination ARB-CCB, ACEI-CCB, and ARB-diuretic medications. The chronotherapy of conventional hypertension medications constitutes a new and cost-effective strategy for enhancing the control of daytime and nighttime SBP and DBP levels, normalizing the dipping status of their 24-h patterning, and potentially reducing the risk of CVD events and end-organ injury, for example, of the blood vessels and tissues of the heart, brain, kidney, and retina. (Author correspondence: rhermida@uvigo.es)     

高血压颅内肿瘤患者预防性吸入七氟醚术中脑血流及颅内压变化分析

摘要 目的：分析高血压颅内肿瘤患者预防性吸入七氟醚术中脑血流及颅内压变化情况。方法：选取2018年8月至2019年8月我院收治的80例高血压颅内肿瘤患者作为研究对象,随机将其分为两组,对照组40例,给予丙泊酚维持麻醉;研究组40例,给予七氟醚维持麻醉,观察两组患者的脑血流及颅内压变化情况。结果：1）两组患者大脑前动脉（anteriorcerebral artery,ACA）、大脑中动脉（middle cerebral artery,MCA）、大脑后动脉（posterior cerebral artery,PCA）血流动力学指标比较,麻醉前（T0）阻力指数（resistance Index,RI）和时间平均流速（the average velocity,Vm）差异无统计学意义(P>0.05);诱导麻醉（T1）、维持麻醉（T2）、手术结束（T3）时间点RI和Vm比较,研究组均明显优于对照组(P<0.05);2）两组患者麻醉前颅内压(intracranial pressure,ICP)比较差异无统计学意义(P>0.05);T1、T2、T3时间点,两组患者ICP进行比较,研究组明显低于对照组(P<0.05)。结论：预防性吸入七氟醚对于高血压颅内肿瘤患者术中能够维持脑血流稳定,同时降低患者的颅内压,使患者深度麻醉,避免术中一些风险事件的发生,具有很好的临床意义,值得推广和应用。     

Effects of Time-of-Day of Hypertension Treatment on Ambulatory Blood Pressure and Clinical Characteristics of Patients With Type 2 Diabetes

Generally, hypertensive patients ingest all their blood pressure (BP)-lowering agents in the morning. However, many published prospective trials have reported clinically meaningful morning-evening, treatment-time differences in BP-lowering efficacy, duration of action, and safety of most classes of hypertension medications, and it was recently documented that routine ingestion of ≥1 hypertension medications at bedtime, compared with ingestion of all of them upon awakening, significantly reduces cardiovascular disease (CVD) events. Non-dipping (<10% decline in asleep relative to awake BP mean), as determined by ambulatory BP monitoring (ABPM), is frequent in diabetes and is associated with increased CVD risk. Here, we investigated the influence of hypertension treatment-time regimen on the circadian BP pattern, degree of BP control, and relevant clinical and analytical parameters of hypertensive patients with type 2 diabetes evaluated by 48-h ABPM. This cross-sectional study involved 2429 such patients (1465 men/964 women), 65.9?±?10.6 (mean?±?SD) yrs of age, enrolled in the Hygia Project, involving primary care centers of northwest Spain and designed to evaluate prospectively CVD risk by ABPM. Among the participants, 1176 were ingesting all BP-lowering medications upon awakening, whereas 1253 patients were ingesting ≥1 medications at bedtime. Among the latter, 336 patients were ingesting all BP-lowering medications at bedtime, whereas 917 were ingesting the full daily dose of some hypertension medications upon awakening and the full dose of others at bedtime. Those ingesting ≥1 medications at bedtime versus those ingesting all medications upon awakening had lower likelihood of metabolic syndrome and chronic kidney disease (CKD); had significantly lower albumin/creatinine ratio, glucose, total cholesterol, and low-density lipoprotein (LDL) cholesterol; and had higher estimated glomerular filtration rate and high-density lipoprotein (HDL) cholesterol. Moreover, patients ingesting all medications at bedtime had lowest fasting glucose, serum creatinine, uric acid, and prevalence of proteinuria and CKD. Ingestion of ≥1 medications at bedtime was also significantly associated with lower asleep systolic (SBP) and diastolic BP (DBP) means than treatment with all medications upon awakening. Sleep-time relative SBP and DBP decline was significantly attenuated in patients ingesting all medications upon awakening (p?<?.001). Thus, the prevalence of non-dipping was significantly higher when all hypertension medications were ingested upon awakening (68.6%) than when ≥1 of them was ingested at bedtime (55.8%; p?<?.001 between groups), and even further attenuated (49.7%) when all of them were ingested at bedtime (p?<?.001). Additionally, prevalence of the riser BP pattern, associated with highest CVD risk, was much greater (23.6%) among patients ingesting all medications upon awakening, compared with those ingesting some (20.0%) or all medications at bedtime (12.2%; p?<?.001 between groups). The latter group also showed significantly higher prevalence of properly controlled ambulatory BP (p <?.001) that was achieved by a significantly lower number of hypertension medications (p?<?.001) compared with patients treated upon awakening. Our findings demonstrate significantly lower asleep SBP mean and attenuated prevalence of a blunted nighttime BP decline, i.e., lower prevalence of markers of CVD risk, and improved metabolic profile in patients with type 2 diabetes ingesting hypertension medications at bedtime than in those ingesting all of them upon awakening. These collective findings indicate that bedtime hypertension treatment, in conjunction with proper patient evaluation by ABPM to corroborate the diagnosis of hypertension and avoid treatment-induced nocturnal hypotension, should be the preferred therapeutic scheme for type 2 diabetes. (Author correspondence: rhermida@uvigo.es)     

床旁超声联合颅内血流监测预测心肺复苏患者颅内压升高的效果研究

摘要 目的：探讨床旁超声联合颅内血流监测预测心肺复苏患者颅内压升高的效果。方法：选择2020年1月至2022年12月在本院重症医学科行心肺复苏治疗的60例患者作为研究对象,于心肺复苏术后采用脑室测压导管测定颅内压,根据颅内压结果将患者分为颅内高压组和正常组。采用酶联免疫吸附法检测两组患者血清脑源性神经营养因子（BDNF）、中枢神经特异性蛋白（S100β）和神经元特异性烯醇化酶（NSE）水平。比较两组患者视神经鞘宽度（ONSD）、大脑中动脉搏动指数（MCA-PI）。采用Pearson分析颅内压、ONSD与MCA-PI之间的相关性。绘制受试者工作特征（ROC）曲线分析患者ONSD、MCA-PI对的心肺复苏术后颅内压升高的预测价值。结果：（1）60例心肺复苏患者中19例出现颅内压升高;（2）颅内高压组患者血清BDNF、S100β和NSE水平均显著高于正常组（P<0.05）;（3）颅内高压组患者ONSD和MCA-PI均显著高于正常组（P<0.05）;（4）心肺复苏患者ICP与ONSD、MCA-PI均呈显著正相关关系（r=0.872、0.848,P<0.05）。（5）ONSD和MCA-PI预测心肺复苏患者发生颅内压升高的AUC分别为0.875（95%CI：0.739~1.000）、0.841（95%CI：0.735~0.948）。ONSD预测心肺复苏患者颅内压升高的最佳截断值为≥5.69 mm,对应敏感度、特异度、约登指数、阳性预测值和阴性预测值分别为78.95%、100.00%、78.95%、100.00%和91.11%;MCA-PI预测心肺复苏患者颅内压升高的最佳截断值为≥0.945,对应敏感度、特异度、约登指数、阳性预测值和阴性预测值分别为78.95%、80.49%、59.44%、65.22%和89.19%。结论：床旁超声和颅内血流监测均无创安全,ONSD和MCA-PI都可以有效预测心内复苏患者颅内压升高,ONSD预测效能更佳。     

Overweight,Obesity, and Blood Pressure: The Effects of Modest Weight Reduction

Several large epidemiological studies have shown an association between body mass index and blood pressure in normal weight and overweight patients. Weight gain in adult life especially seems to be an important risk factor for the development of hypertension. Weight loss has been recommended for the obese hypertensive patient and has been shown to be the most effective nonpharmacological treatment approach. However, long‐term results of weight loss programs are disappointing with people often regaining most of the weight initially lost. In recent years, a modest weight loss, defined as a weight loss of 5% to 10% of baseline weight, has received increasing attention as a new treatment strategy for overweight and obese patients. A more gradual and moderate weight loss is more likely to be maintained over a longer period of time. Several studies have confirmed the blood pressure‐lowering effect of a modest weight loss in both hypertensive and nonhypertensive patients. A modest weight loss can normalize blood pressure levels even without reaching ideal weight. In patients taking antihypertensive medication, a modest weight loss has been shown to lower or even discontinue the need for antihypertensive medication. In patients with high normal blood pressure, a modest weight loss can prevent the onset of frank hypertension. The blood pressure‐lowering effect of weight loss is most likely a result of an improvement in insulin sensitivity and a decrease in sympathetic nervous system activity and occurs independent of salt restriction. In conclusion, a modest weight loss that can be maintained over a longer period of time is a valuable treatment goal in hypertensive patients.     

激光针灸对穴位组织温度和血流灌注率的影响

本文在Pennes方程的基础上研究了激光针灸治疗对穴位组织的温度和血流灌注率的影响。结果显示,连续激光与脉冲激光针灸都能使穴位组织的温度和血流灌注率升高,随着激光的功率密度升高则穴位组织的温度和血流灌注率亦升高。通过这些研究为激光针灸的临床实际应用提供了理论基础。     

Influence of Aspirin Usage on Blood Pressure: Dose and Administration-Time Dependencies

This study investigates the possible effects of acetylsalicylic acid (ASA; aspirin) on systolic (S) and diastolic (D) blood pressure (BP) in healthy and mildly hypertensive subjects receiving ASA at different times according to their rest-activity cycle. A double-blind, randomized, controlled trial was conducted in 73 healthy young adult volunteers and 18 previously untreated subjects with mild hypertension. The BP of each subject was automatically monitored every 30 minutes for 48h before the trial and at the end of a one-week course of placebo and a one-week course of ASA. Healthy volunteers were randomly assigned to one of six groups, defined according to the dose of ASA (either 500 mg/day, the usual commercial dose; or 100 mg/day) and timing of ASA and placebo (within 2h after awakening, Time 1; 7h to 9h after awakening, Time 2; or within 2h of bedtime, Time 3). Subjects with mild hypertension the low dose of 100 mg/day ASA, as well as one week of placebo, and were randomly assigned to one of the same three groups defined above according to the time of treatment. A small (?2 mmHg in the 24h mean of SBP), but statistically significant, BP reduction was found when 500 mg/day ASA was given to healthy volunteers at Time 2. With 100 mg/day, the effect of ASA in healthy subjects was comparable to the BP reduction found with the higher dose for Time 2; there was again no effect on BP at Time 1, but we found a statistically significant effect at Time 3 (2.3 mmHg reduction in the 24h mean of SBP), larger than for Time 2. For hypertensive patients, the BP reduction was again statistically significant for Time 2 and, to a greater extent, for Time 3 (?4.5 mmHg for both SBP and DBP); all patients in these two groups showed a BP reduction after one week of ASA. The effect was about three times as large as the BP reduction obtained in healthy subjects treated with 100 mg/day ASA. Results indicate a statistically significant time- and dose-dependent effect of ASA on BP. In any meta-analysis of ASA effects, inquiries about the time when subjects took the drug are indicated and may account for discrepancies in the literature. Moreover, the influence of ASA on BP demonstrated here indicates the need to identify and control for ASA effects in patients using ASA before or during their participation in antihypertension medication trials. (Chronobiology International, 14(6), 619–637, 1997)     

Effects of Different Once-a-Day Medications on 24-Hour Blood Pressure Recordings in Hypertensives

Compliance with antihypertensive treatment can be increased by using medications that are taken only once daily. There is, however, concern as to whether the efficacy of such drugs is sufficient to cover 24 h. Ambulatory blood pressure monitoring (ABPM) is an ideal technique to assess the effect of this kind of drug and to determine over- or undertreatment. In this study three drugs were examined as once-a-day preparations. Thirty-six patients were treated with three different doses of bisoprolol, as an example of the β,-selective beta-blockers; 12 patients were treated with a combination of the AChE-inhibitor enalapril and hydrochlorothiazide; eight patients were treated with nifedipine once per day, a new galenic form of nifedipine, as an example of the calcium-channel blockers. In each group we saw a significant downward shift over the entire 24-h curve. Our results also show that using 24-h blood pressure monitoring devices can help establish an appropriate dose, avoid over- and undertreatment, and control the total burden of the patient.