Role of the Baroreflex in Cardiovascular Instability: A Modeling Study

A mathematical model of the short-term arterial pressure control is used to investigate the possible origin of blood pressure waves (Mayer waves) and of heart rate variability signals. The model includes an elastance-variable pulsating heart, the pulmonary and systemic circulation, the mechanical effect of respiration on venous return, and the regulatory actions of two groups of baroreceptors: the high-pressure (i.e., arterial) baroreceptors and the low-pressure (i.e., cardiopulmonary) baroreceptors. The feedback mechanisms work by modulating the peripheral resistances, the venous unstressed volumes, the ventricle end-systolic elastance and the heart period. The last mechanism involves a balance between sympathetic and vagal control actions. The basal value of all parameters in the heart and vascular model has been given to mimic a normal human hemodynamic. Parameters in the feedback regulation mechanisms have been assigned on the basis of open loop experiments in vagotomized dogs (as to the sympathetic arterial baroreflex) and neck chamber or lower body negative pressure experiments in human volunteers (as to vagal response and cardiopulmonary baroreflex). A sensitivity analysis on the gains and time delays of the feedback mechanisms revealed that (i) a significant increase in the gains and time delays (above 9 s) of all the arterial baroreflex sympathetic mechanisms is required to induce instability. In this condition, systemic arterial pressure exhibits spontaneous oscillations with a period of about 20 s, similar to Mayer waves. The control of peripheral resistance seems more important than the venous volume control in the genesis of these oscillations. (ii) An increase in the gain and time delay (above 3 s) of the arterial baroreflex vagal mechanism causes the appearance of unpredictable fluctuations in heart period, with spectral components in the range 0.08–0.12 Hz. These fluctuations originate after a double period bifurcation. (iii) The cardiopulmonary baroreflex plays a less important role in the genesis of the aforementioned instability phenomena.     

The Effect of Vagus Nerve Stimulation on Epileptiform Activity Recorded from Hippocampal Depth Electrodes

PURPOSE: To assess the effect of vagus nerve stimulation (VNS) on interictal epileptiform activity in the human hippocampus. Clinical studies have established the efficacy of vagus nerve stimulation in patients with epilepsy (VNS Study Group, 1995), although the electrophysiologic effects of VNS on the human hippocampus and mesial temporal lobe structures remain unknown. METHODS: We report a case study in which a patient with an implanted VNS underwent intracranial electrode recording before temporal lobectomy for intractable complex partial seizures. Epileptiform spikes and sharp waves were recorded from a depth electrode placed in the patient's left hippocampus. Spike frequencies and sharp-wave frequencies before and during VNS were compared using both a 5- and a 30-Hz stimulus. Different stimulation rates were tested on different days, and all analyses were performed using a Student's t test. RESULTS: We found no significant differences in spike frequency between baseline periods and stimulation at 5 and 30 Hz. In contrast, stimulation at 30 Hz produced a significant decrease in the occurrence of epileptiform sharp waves compared with the baseline, whereas stimulation at 5 Hz was associated with a significant increase in the occurrence of epileptiform sharp waves. CONCLUSIONS: VNS produces a measurable electrophysiologic effect on epileptiform activity in the human hippocampus. Although a clinical response to VNS did not occur in our patient before surgery, 30-Hz VNS suppressed interictal epileptiform sharp waves that were similar in appearance to those seen during the patient's actual seizures. In contrast, 5-Hz stimulation appeared to increase the appearance of interictal sharp waves.     

Real steak knives of cincinnati: Repeated foreign body ingestion with novel endoscopic removal

Repeated ingestion of foreign objects presents a multidisciplinary endoscopic dilemma. We report a 32‐year‐old female patient with history of multiple previous foreign body ingestions requiring several past exploratory laparotomies, who presents with a knife blade in the esophagus. We present a novel method of using a rigid cervical esophagoscope with a salivary bypass tube. The tip of the knife was isolated into the cervical esophagoscope, and the salivary bypass tube advanced off the cervical esophagoscope over the knife, shielding the serrated edge during removal preventing laceration to the esophagus. Laryngoscope, 129:567–568, 2019     

清肾颗粒对慢性肾功能衰竭急剧加重湿热证患者肿瘤坏死因子及其受体的干预作用

目的：观察慢性肾功能衰竭（CRF）急剧加重湿热证患者血清肿瘤坏死因子-α（TNF-α）、可溶性肿瘤坏死因子受体Ⅰ（sTNFRⅠ）水平及清肾颗粒的干预作用。方法：60例CRF急剧加重湿热证患者随机分为治疗组和对照组，各30例，并选取20名健康体检者作为正常人组。治疗组与对照组均使用中药解毒泄浊Ⅱ号保留灌肠，治疗组加用清肾颗粒，每次2袋，每日3次。检测治疗组与对照组治疗前后TNF-α、sTNFRⅠ水平变化情况，并与正常人组比较。结果：治疗组临床疗效和中医证候疗效总有效率（80．00%和83．33％）明显高于对照组（53．33%和56．67％），两组比较差异均有显著性（P均〈0．05）。CRF急剧加重湿热证患者治疗前血清TNF-α、sTNFR Ⅰ水平明显高于正常人组（P均〈0．01）；治疗组治疗后患者血清TNF-α、sTNFR Ⅰ下降（P均〈0．05）；对照组治疗前后差异均无显著性（P均〉0．05）。两组治疗后比较，治疗组患者血清TNF-α、sTNFR Ⅰ水平较对照组明显下降（P均〈0．05），CRF急剧加重湿热证患者治疗前中医证候积分、SCr、血清TNF-α、sTNFRⅠ之间均呈明显正相关（P均〈0．05）。结论：CRF急剧加重湿热证患者血清TNF-α、sTNFR Ⅰ水平明显升高，清肾颗粒可降低其水平，改善肾功能，减轻临床症状。     

高能震波治疗肌肉骨关节慢性疼痛性疾病的临床研究

目的　观察高能震波对肩周炎等肌肉骨关节疾病引起的慢性疼痛的治疗效果 ,探讨其作用机制及临床应用。方法　选择 90例门诊患者 ,随机分为治疗组和对照组 ,治疗组采用ESWO AJ体外冲击波治疗机进行治疗 ,工作电压为 7～ 10kV ,冲击波频率为 60次 /min ;对照组按照病种选用相应常规物理因子疗法。采用简式McGill疼痛问卷 (MPQ)等方法进行疗效评估并比较。结果　治疗组治疗后功能明显改善 ,治愈率71.1% ,明显高于对照组 ( 4 0 .0 % ) (P <0 .0 1)。在治疗后情感类 (A)、疼痛总分 (T)与目测类比量表 (VAS)评分中 ,治疗组明显优于对照组 (P <0 .0 1或P <0 .0 5 )。且两组在治疗次数上差异有非常显著性意义 (P <0 .0 0 1)。结论　体外高能震波对肌肉骨关节疾病的慢性疼痛疗效确切 ,应用于临床具有高效、快速和安全的特点。     

2001-2012年我国护理人员锐器伤研究的文献计量分析

目的系统分析我国护理人员锐器伤研究的发展态势及存在问题,为相关研究提供参考。方法采用文献计量方法,构建文献评阅数据库,系统分析2001-2012年收录在中国期刊全文数据库和中国生物医学文献数据库中与护士锐器伤相关的研究类文献。结果共检出研究类文献867篇,文献量呈逐年上升趋势,但基金论文仅占2.0%,97.6%的作者只有1篇文献;867篇文献分布在228种期刊上,其中刊文10篇以上的期刊20种;90%以上的文献研究对象来自单个医疗机构,以护士为独立研究对象的占73.5%;文献以描述性研究为主,占89.5%,危险因素分析和干预研究仅占1.0%和9.5%;研究内容集中在锐器伤现状的回顾性调查、暴露资料的统计分析和培训干预的效果评价。文献报道的护理人员锐器伤年平均发生率为63.5%～91.3%,职业暴露率为2.4%～28.8%,仅6.9%～45.0%的护士发生锐器伤时戴手套,伤口处理正确率为34.6%～48.2%。结论护理人员锐器伤的研究在国内已引起重视,但研究内容单一、研究方法科学性不强、缺乏高产出的作者,尚需形成一个持续关注锐器伤问题的核心作者群,开展高质量的危险因素分析与干预研究,为临床护理人员预防锐器伤提供更强有力的循证依据。     

锐性吸脂针腋皱襞入路肿胀抽吸法治疗男性乳房发育症

目的:改良目前治疗男性乳房发育症的手术方法,观察其效果。方法:术前应用高频超声探头选择脂肪和乳腺组织均有增生的男性乳房发育症患者18例,以腋皱襞前端为入路,单纯应用锐性吸脂针对增大的乳房进行肿胀抽吸治疗,吸出物送病理学检查。结果:乳房胸部塑形良好,无血肿、乳头乳晕感觉障碍等并发症。胸部无手术痕迹残留。随访3～18月无复发。病理检查结果显示吸出物中有增生的乳腺组织,病理特点符合男性乳腺发育症。结论:对于脂肪和乳腺组织均有增生的男性乳房发育症,锐性吸脂针腋皱襞入路单纯肿胀抽吸术是一种可选的有效手术方法。     

Suppression wave dynamics: Visual field anisotropies and inducer strength

We used binocular rivalry and generalized flash suppression to identify several new shared properties of traveling suppression waves. A strong relationship was found between suppression wave speed and induction pulse strength: increasing the contrast or dot density of the induction pulse led to an increase in wave speed. Evidence of visual field anisotropies in wave propagation speeds were also seen, with suppression waves decelerating as they travel towards the fovea. This deceleration could not be accounted for by cortical magnification in lower level brain areas, suggesting an important role for other, yet to be identified, factors.     

飞行生理参数记录检测仪在舰艇冲击试验中的应用

目的 利用飞行生理参数记录检测仪监测舰艇在遭受水下非接触爆炸冲击时所受冲击力大小及爆炸前后舰员生理参数的变化,为在实船非接触爆炸试验中对舰员进行实时监测提供一种方法和技术手段.方法 利用飞行员飞行生理参数记录检测仪(又称BodyMonBelt生参仪),监测舰艇在遭受水下非接触爆炸冲击前后,处在舰艇不同位置的9名舰员的心电图、心率、呼吸率、体表温度及所受两轴向加速度值(Gz、Gy).统计爆炸点前后30 min内受试者的心率、呼吸率及体表温度变化,进行自身对比分析.结果 人体表心脏部位所受冲击Gz值为0.23～2.17 G、Gy值为-0.39～0.66 G,在人体可承受的冲击力范围内.爆炸前舰员最快心率107～171次/min,最快呼吸率22～29次/min;爆炸后最快心率113～155次/min,最快呼吸率24～33次/min;爆炸后30 min内平均心率和平均呼吸率均高于爆炸前,平均心率前后对比有统计学意义(t=2.929,P=0.019);体表温度无明显变化.结论 BodyMonBelt生参仪可准确记录爆炸试验过程中舰员所受冲击作用的强度,可同步记录舰员在此爆炸试验过程中的有关生理参数变化,是分析人体在危险试验过程中生理心理指标变化的有效监测设备.分析监测结果和比较,人体生理耐限值的结果表明,舰员通过穿戴防护装备和掌握正确防护姿势,可以有效防护本次当量级的冲击作用损伤. Abstract： Objective To monitor the explosion impact and its influence to the shipboard personnnel's physiological state by BodyMonBelt-a biomedical monitoring equipment for aviation in the experiment of non-contact underwater explosion on warship and to promote a real-time monitoring technique. Methods In the experiment of non-contact underwater torpedo explosion on warship, 9 shipboard personnel and a manikin, who were in different locations, were monitored by BodyMonBelt. The recorded parameters included ECG, HR, respiratory rate, body temperature and bi-axial acceleration values (Gy and Gz), of which only accelerations were recorded on manikin. Several other BodyMonBelt devices were placed in different location for recording the explosive impact to ship body. Self-comparimn analysis on HR,respiratory rate and body temperature that measured in 30 min before and after explosion was taken.Results The acceleration range applied by explosion at heart position was respectively 0. 23-2. 17 G and -0. 39-0. 66 G along Gz and Gy axis and those were in endurable range of human body. The highest HR and respiratory rate prior to explosion could be in the ranges of 107-171 beats/min and 22-29 times/min and average HR and respiratory rate, gathered at 30 min after explosion, were higher than those before explosion (t=2.929, P=0.019). The body temperature had no significant change in experiment. Conclusions BodyMonBelt could accurately record the explosion impact that applied on ship body and shipboard personnel, and simultaneously monitor the related physiological changes. It would be an applicable equipment in analyzing physiological and psychological state of the people who works in hazardous environment. By analyzing the BodyMonBelt recorded results and comparing physiological tolerance limit, it is showed that wearing proper shield and maintaining right posture could effectively protect the shipboard personnel from the explosive impact at experiment equivalent grade.