Visual fixations and visually induced dizziness: An exploratory study

BackgroundVisually induced dizziness can develop as a sequala of a vestibular disorder and is characterized by symptoms of nausea, dizziness, and imbalance in rich visual environments such as supermarkets and shopping malls. To date the mechanisms underlying visually induced dizziness are poorly understood.Research questionWhat are the characteristics of visual fixations and postural sway in adults with visually induced dizziness compared to healthy adults when exposed to increasingly complex visual environments?MethodsWe recruited 20 adults with visually induced dizziness and 20 healthy adults to this cross-sectional exploratory study. Participants were instructed to maintain gaze on letters projected on a large screen with backgrounds of differing visual complexity. The number of visual refixations, movement of the centre of pressure, and movement of the head and body centres of mass were recorded.ResultsAdults with visually induced dizziness showed a significantly higher number of visual refixations (F= 10.592, p < 0.01), and increased mean velocity of head and body centres of mass movement (F= 14.034, p < 0.01 and F= 6.553, p < 0.05 respectively) compared to healthy adults.SignificanceAdults with visually induced dizziness exhibited visual fixational instability and increased postural and head sway compared to healthy adults. This was mainly observed in conditions with complex and moving backgrounds. This may account for reports from adults with visually induced dizziness of worsening symptoms in busy environments. The results from the study may assist in guiding intervention development to reduce symptoms of visually induced dizziness.     

Tumour volume distribution can yield information on tumour growth and tumour control

BackgroundIt is shown that tumour volume distributions can yield information on two aspects of cancer research: tumour induction and tumour control.Materials and methodsFrom the hypothesis that the intrinsic distribution of breast cancer volumes follows an exponential distribution, firstly the probability density function of tumour growth time was deduced via a mathematical transformation of the probability density functions of tumour volumes. In a second step, the distribution of tumour volumes was used to model the variation of the clonogenic cell number between patients in order to determine tumour control probabilities for radiotherapy patients.ResultsDistribution of lag times, i.e. the time from the appearance of the first fully malignant cell until a clinically observable cancer, can be used to deduce the probability of tumour induction as a function of patient age. The integration of the volume variation with a Poisson-TCP model results in a logistic function which explains population-averaged survival data of radiotherapy patients.ConclusionsThe inclusion of tumour volume distributions into the TCP formalism enables a direct link to be deduced between a cohort TCP model (logistic) and a TCP model for individual patients (Poisson). The TCP model can be applied to non-uniform tumour dose distributions.     

Cardioprotective effects of sinomenine in myocardial ischemia/reperfusion injury in a rat model

BackgroundIschemia reperfusion (I/R) play an imperative role in the expansion of cardiovascular disease. Sinomenine (SM) has been exhibited to possess antioxidant, anticancer, anti-inflammatory, antiviral and anticarcinogenic properties. The aim of the study was scrutinized the cardioprotective effect of SM against I/R injury in rat.MethodsRat were randomly divided into normal control (NC), I/R control and I/R + SM (5, 10 and 20 mg/kg), respectively. Ventricular arrhythmias, body weight and heart weight were estimated. Antioxidant, inflammatory cytokines, inflammatory mediators and plasmin system indicator were accessed.ResultsPre-treated SM group rats exhibited the reduction in the duration and incidence of ventricular fibrillation, ventricular ectopic beat (VEB) and ventricular tachycardia along with suppression of arrhythmia score during the ischemia (30 and 120 min). SM treated rats significantly (P < 0.001) altered the level of antioxidant parameters. SM treatment significantly (P < 0.001) repressed the level of creatine kinase MB (CK-MB), creatine kinase (CK) and troponin I (Tnl). SM treated rats significantly (P < 0.001) repressed the tissue factor (TF), thromboxane B2 (TXB2), plasminogen activator inhibitor 1 (PAI-1) and plasma fibrinogen (Fbg) and inflammatory cytokines and inflammatory mediators.ConclusionOur result clearly indicated that SM plays anti-arrhythmia effect in I/R injury in the rats via alteration of oxidative stress and inflammatory reaction.     

Increased alpha suppression with age during involuntary memory retrieval

Recent work suggests that while voluntary episodic memory declines with age, involuntary episodic memory, which comes to mind spontaneously without intention, remains relatively intact. However, the neurophysiology underlying these differences has yet to be established. The current study used electroencephalography (EEG) to investigate voluntary and involuntary retrieval in older and younger adults. Participants first encoded sounds, half of which were paired with pictures, the other half unpaired. EEG was then recorded as they listened to the sounds, with participants in the involuntary group performing a sound localization cover task, and those in the voluntary group additionally attempting to recall the associated pictures. Participants later reported which sounds brought the paired picture to mind during the localization task. Reaction times on the localization task were slower for voluntary than involuntary retrieval and for paired than unpaired sounds, possibly reflecting increased attentional demands of voluntary retrieval and interference from reactivation of the associated pictures respectively. For the EEG analyses, young adults showed greater alpha event-related desynchronization (ERD) during voluntary than involuntary retrieval at frontal and occipital sites, while older adults showed pronounced alpha ERD regardless of intention. Additionally, older adults showed greater ERD for paired than unpaired sounds at occipital sites, likely reflecting visual reactivation of the associated pictures. Young adults did not show this alpha ERD memory effect. Taken together, these data suggest that involuntary memory is largely preserved with age, but this may be due to older adults' greater recruitment of top-down control even when demand for such control is limited.     

基于全球视角的中国骨关节炎疾病负担分析

目的 掌握我国30岁以上人群骨关节炎的疾病负担现状与趋势，发现重点人群，为制定骨关节炎综合防制策略提供科学依据。方法 利用全球疾病负担数据库2019（GBD 2019），对中国30岁以上人群按照性别、年龄分组描述骨关节炎的发病率、患病率、伤残损失健康生命年（Years lived with disability, YLD），并与全球和日本、印度进行比较，分析1990—2019年骨关节炎的疾病负担与其变化趋势。作图使用GraphPad Prism 8软件。结果 2019年，中国骨关节炎患病人数约1.33亿，所致YLD约472.49万人年，占中国全因YLD的3.07%，占全球骨关节炎导致YLD的24.93%；其发病率高峰在50～54岁年龄组，各年龄段女性发病率均约为男性的1.5倍。1990—2019年，中国骨关节炎发病率、患病率、YLD率均呈逐年上升趋势，2019年依次为750.96/10万、9337.15/10万、224.78/10万，较1990年分别增加93.62%、113.53%、116.13%，均远超同期日本、印度及全球的增幅；年龄标准化后的以上指标显示，中国骨关节炎疾病负担低于日本、高于印度、接近全球平均水平。结论 随着人口老龄化程度的加深，1990—2019年我国30岁以上人群骨关节炎疾病负担越来越重，一级预防重点人群为35岁以下和未患病人群，尤其是女性，可见制定科学有效的骨关节炎综合防制方案已迫在眉睫。     

口腔科门诊应对新型冠状病毒感染防疫探讨

目前新型冠状病毒感染疫情在全国蔓延，疫情防控成为医院工作的重点。口腔科门诊患者人流量大、口腔疾患多、口腔内病菌种类复杂、诊疗过程中患者无法戴口罩、医务人员的手和器械需要接触患者的唾液、血液、病菌等，特别是在相对封闭的环境中长时间暴露于高浓度气溶胶情况下存在经气溶胶传播的可能。本院口腔科门诊通过开诊前准备、就诊期间应急管理、消毒隔离管理等方面细化防疫措施，成果显著，有效保障医患安全。