Resiniferatoxin reduces cardiac sympathetic nerve activation to exert a cardioprotective effect during myocardial infarction

Background and objective: Myocardial infarction (MI) is a common critical disease of the cardiovascular system. The process of MI is often accompanied by the excessive activation of cardiac sympathetic nerves, which leads to arrhythmia. Resiniferatoxin (RTX) is a transient receptor potential vanilloid 1 (TRPV1), involved in the cardiac sympathetic afferent reflex. However, whether RTX can reduce the occurrence of arrhythmia and exert a cardioprotective effect by inhibiting the sympathetic reflex during MI is still unknown. Methods: The left anterior descending artery of cardiac was clamped to construct a model of MI. RTX (50 μg/ml) was used by epicardial application in MI rats. Ventricular electrophysiologic properties were continuously monitored by a body surface ECG. Yrosine hydroxylase (TH) and growth associated protein 43 (GAP43) were detected by Immunofluorescence staining. Connexin43 and transforming growth factor beta receptor 1 (TGF-β1) were detected by western blot. Norepinephrine (NE) and BNP levels in blood and tissue were determined by ELISA. Cardiac function was assessed by echocardiography. Results: The ERP, APD90, QRS, QT and the Tend-Tpeak intervals in MI rats were all prolonged, but decreased after RTX treatment (n = 3, P<0.05). In contrast, the RR interval was shortened in the MI group, but prolonged in the MI+RTX group (n = 3, P<0.05). RTX treatment significantly reduced ventricular arrhythmias after MI. TH- and GAP43-positive nerve densities and TGF-β1, and cx-43 protein expression were up-regulated in the MI group compared to the sham group, and they were decreased in the MI+RTX group compared to the MI group (n = 3, P<0.05). RTX can decrease serum and tissue NE and BNP levels (n = 3, P<0.05). RTX pretreatment significantly decreased heart rate, HW/BW ratio and LVIDS, and increased LVEF andLVFS values (n = 3, P<0.05). Conclusion: RTX improved cardiac dysfunction, ventricular electrophysiologic properties, and sympathetic nerve remodeling in rats with MI by inhibiting the excessive cardiac sympathetic drive.     

Vestibular Function Measurement Devices

Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments.     

A modality-specific somatosensory evoked potential test protocol for clinical evaluation: A feasibility study

ObjectiveWe aimed to establish an objective neurophysiological test protocol that can be used to assess the somatosensory nervous system.MethodsIn order to assess most fiber subtypes of the somatosensory nervous system, repetitive stimuli of seven different modalities (touch, vibration, pinprick, cold, contact heat, laser, and warmth) were synchronized with the electroencephalogram (EEG) and applied on the cheek and dorsum of the hand and dorsum of the foot in 21 healthy subjects and three polyneuropathy (PNP) patients. Latencies and amplitudes of the modalities were assessed and compared. Patients received quantitative sensory testing (QST) as reference.ResultsWe found reproducible evoked potentials recordings for touch, vibration, pinprick, contact-heat, and laser stimuli. The recording of warm-evoked potentials was challenging in young healthy subjects and not applicable in patients. Latencies were shortest within Aβ-fiber-mediated signals and longest within C-fibers. The test protocol detected function loss within the Aβ-fiber and Aδ-fiber-range in PNP patients. This function loss corresponded with QST findings.ConclusionIn this pilot study, we developed a neurophysiological test protocol that can specifically assess most of the somatosensory modalities. Despite technical challenges, initial patient data appear promising regarding a possible future clinical application.SignificanceEstablished and custom-made stimulators were combined to assess different fiber subtypes of the somatosensory nervous system using modality-specific evoked potentials.     

创伤后重型急性弥漫性脑肿胀临床治疗策略

目的 探讨重型创伤后急性弥漫性脑肿胀（PADBS）患者保守治疗与手术治疗的疗效。方法 分析 2016年1月—2019年12月该院神经外科收治的44例重型PADBS患者，根据治疗方式分为手术组和保守治疗组，统计入院时格拉斯哥昏迷量表（GCS）评分、头颅CT检查情况、伤后6个月格拉斯哥预后量表（GOS）评分等资料。结果 两组患者入院时年龄、性别及GCS评分比较，差异无统计学意义（P>0.05）。两组患者伤后6个月时GOS评分比较，差异无统计学意义（P>0.05），但两组住院时间比较，差异有统计学意义（P<0.05），手术组长于保守治疗组。结论 重型PADBS在无瞳孔变化及GCS评分下降的情况下，可密切观察病情下选择保守治疗。     

High-Pressure Water Swelling Sealant Injection Injury to the Hand: a Case Report and Review of the Literature

High-pressure injection injuries (HPII) caused by water swelling sealant are rare at present. The patient generally has small-sized skin lesions, and the misleadingly benign presentation may cause delayed treatment at the early stage of management. In addition, radiographic examination may be underestimated. Subsequently, the inadequate surgical intervention may cause tissue necrosis and poor prognosis. Furthermore, the early recognition of water swelling sealant injected into tissue and emergent surgical intervention are the key to successful management for the patient with HPII caused by injecting water swelling sealant to tissue.     

Influence of posture on blink reflex prepulse inhibition induced by somatosensory inputs from upper and lower limbs

BackgroundPrepulse inhibition (PPI) is a neurophysiological phenomenon whereby a weak stimulus modulates the reflex response to a subsequent strong stimulus. Its physiological purpose is to avoid interruption of sensory processing by subsequent disturbing stimuli at the subcortical level, thereby preventing undesired motor reactions. An important hub in the PPI circuit is the pedunculopontine nucleus, which is also involved in the control of posture and sleep/wakefulness.ObjectiveTo study the effect of posture (supine versus standing) on PPI, induced by somatosensory prepulses to either upper or lower limb. PPI was measured as the percentage inhibition of the blink reflex response to electrical supraorbital nerve (SON) stimulation.MethodsSixteen healthy volunteers underwent bilateral blink reflex recordings following SON stimulation either alone (baseline) or preceded by an electrical prepulse to the median nerve (MN) or sural nerve (SN), both in supine and standing. Stimulus intensity was 8 times sensory threshold for SON, and 2 times sensory threshold for MN and SN, respectively. Eight stimuli were applied in each condition.ResultsBaseline blink reflex parameters did not differ significantly between the two postures. Prepulse stimulation to MN and SN caused significant inhibition of R2. In supine but not in standing, R2 was significantly more inhibited by MN than by SN prepulses. In standing, SN stimulation caused significantly more inhibition of R2 than in supine, while the inhibition caused by MN prepulses did not differ significantly between postures.SignificancePPI induced by lower limb afferent input may contribute to postural control while standing.     

Investigating the association between eye colour and the Neurological Pupil index

IntroductionBrown or dark brown eyes make it difficult to distinguish the contrast between a black pupil and the surrounding iris, which may result in clinical assessment errors. The pupillometer can be used to derive an indexed value, the Neurological Pupil index™ (NPi) for pupillary light reflex. However, there are limited data associating the NPi and iris colour. We examine the NPi and eye colour association.MethodsData were pooled from the Establishing Normative Data for Pupillometer Assessments in Neuroscience Intensive Care (END-PANIC) Registry. The analysis includes 14,168 observations collected from 865 patients with neurological conditions who were admitted to the intensive care unit. Summary statistics and statistical models were developed to examine the association using Statistical Analysis Software (SAS) summary procedure.ResultsThe mean age of the cohort was 56 years (standard deviation = 17). Eye colour included dark brown (n = 339), blue (n = 234), brown (n = 173), green (n = 82), and other (n = 37). There was significant differences (p < 0.0001) between mean NPi values by eye colour [blue = 4.08 (0.92), brown = 3.34 (1.45), dark = 3.71 (1.33), green = 4.08 (0.67), other = 3.76 (1.25)]. However, a further random-effects mixed model after controlling for confounding variables revealed no significant difference in NPi values among different eye colour groups.ConclusionsThe pupillary light reflex, when assessed using the pupillometer, is not dependent on the eye colour. Practitioners are not required to consider eye colour as a confounder when they perform pupillary assessment for examining patients with neurological conditions.     

Does the video head impulse test replace caloric testing in the assessment of patients with chronic dizziness? A systematic review and meta-analysis

IntroductionCaloric testing is the most frequently used test to assess peripheral vestibular function since the beginning of the 20th century. However, the video head impulse test, vHIT, has gained prominence in the field of neurotology, as it is a faster examination, easier to perform and less uncomfortable for the patient.ObjectiveTo compare, through systematic review and meta-analysis, the proportion of altered cases between vHIT tests and caloric testing in patients with chronic dizziness, in addition to assessing the sensitivity and specificity of vHIT, with caloric testing as the gold standard.MethodsThe literature search was carried out in the PubMed, Scopus, BVS-Bireme, Web of Science, Embase, Cochrane and ProQuest indexed databases, with no restrictions regarding the publication period. All articles that contained the results of the two tests were included in the evaluation of patients with dizziness. Two researchers independently conducted data selection and extraction from the studies, strictly following the inclusion and exclusion criteria defined in the research protocol. In case of disagreement during the selection, a discussion was carried out with a third evaluator.ResultsEleven of the 1293 initial articles met the eligibility criteria and were analyzed. 2670 patients were evaluated, of which 1112 (41.6%) were males and 1558 (58.4%) females, with a mean age of 51.6 years. The proportion of altered results in the vHIT was 21% (95%CI 9% –33%), and 55% in the caloric testing (95%CI 43% –67%).ConclusionThe vHIT does not substitute for caloric testing. The tests are complementary in assessing the patient with dizziness, as they describe the tonotopy of the ampullary crest at different frequency ranges of stimulation. In chronic cases, the vHIT has a low sensitivity and high diagnostic specificity in comparison to caloric testing.     

重型颅脑损伤的手术治疗

目的探讨重型颅脑损伤梯度减压的手术方法对预防术中脑膨出、降低死亡率及致残率的效果。方法对100例重型颅脑损伤患者采用分次减压手术方式及去骨瓣后，硬膜与颞肌筋膜瓣减张缝闭硬膜切口方法。结果40例脑肿胀患者术中脑嘭出6例占15．0％，死亡19例占47．5％；60例脑内血肿病人未发生脑膨出，死亡12例占20％。结论脑外伤后脑血管调节麻痹及血肿压迫继发脑水肿易造成脑膨出.术中分次减压降低了骨窗部位脑组织的顺应性，从而降低了局部的压力梯度，避免脑血管急性扩张，能有效防止脑膨出，降低死亡率及致残率。     

肛直肠抑制反射时门静脉血中P物质变化

目的探讨肛直肠抑制反射（RAIR）时门静脉血中P物质（SP）的变化规律及外源性内脏神经对其变化的影响。方法将实验大白鼠分为7组，其中6组先按去与不去直肠肛管外源性内脏神经支配而分为不去神经和去神经两大组，每组中又按Foley导管上气囊置入直肠腔中的位置分为2、4、6cm组；同时再设1个对照组，将Foley导管置入直肠腔中，但不注水扩张球囊。检测并比较在直肠腔内刺激后，各组门静脉血中的SP值及变化情况。结果去神经组中2、4cm组与不去神经组之间及对照组之间，门静脉血中SP值变化比较，P〉0．05，差异无统计学意义。不去神经组中的6cm组与对照组及去神经组中2cm和4cm组之间SP值比较，P〈0．01，差异有统计学意义；去神经组和不去神经组中的6cm组之间SP值比较，P〈0．01，差异有统计学意义。结论直肠腔内上部的刺激不引出RAIR可能与该部位的刺激使内括约肌兴奋性递质（SP）的释放有关；外源性内脏神经对RAIR中门静脉血的SP变化有调控作用。