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.     

吕文良教授从“引阳入阴”论瞑眩

瞑眩反应是疾病趋愈的一种祛邪反应,古今医家对其发生机制的观点不一。文章收集、整理瞑眩反应相关文献,总结古、今对瞑眩反应成因的看法,介绍吕文良教授从引阳入阴论瞑眩的经验,以期为临床对其进一步探索提供参考。吕文良教授认为久病之体,宿邪内伏,湿热痰瘀交阻而脏腑经络不通,致卫阳独行于外,不得入阴,机体阴阳失交,而瞑眩反应是机体借助药物作用,引阳入阴,使阴阳复交、正气渐盛,疾病自去而成的一种佳兆。     

Poor Treatment Outcomes Following Repositioning Maneuvers in Younger and Older Adults With Benign Paroxysmal Positional Vertigo: A Systematic Review and Meta-analysis

Objective

This systematic review aimed to methodically review the available evidence on poor treatment outcomes after repositioning maneuver treatments in adults with BPPV and whether there are differences in the outcomes for older and younger adults.

Factors influencing development of residual stresses during crystallization firing in a novel lithium silicate glass-ceramic

ObjectiveDevelopment of residual stresses is a potential source of premature fractures in glassy materials, being of special interest in novel lithium silicate glass-ceramics that require a crystallization firing to achieve their final mechanical properties. The aim of this work was to assess the influence of various firing tray systems and the application of different cooling protocols on the development of residual stresses in Suprinity PC crowns. Their effect on the in vitro lifetime of the restorations was also studied.MethodsThirty crowns were milled out of Suprinity PC blocks and crystallized using one of five different commercial firing tray systems (n = 6). Samples in each group were cooled following a fast (FC = 5.5 °C/s), a slow (SC = 0.4 °C/s) or the manufacturer’s reference cooling (REF ). Obtained crowns were sagittally or transversally sectioned and the magnitude and distribution of residual stresses was determined using the light birefringence method. Extra crowns of three of the subgroups (n = 8) were produced and submitted to chewing simulation for 10⁶ cycles or until fracture ensued.ResultsAverage residual stresses ranged between 0 and 1.5 MPa (peaks of 5 MPa). Highest stress magnitudes were observed at the support areas of groups using firing pins, leading to thermal cracks in FC samples and premature failures in the REF subgroup. The use of fibrous pads and firing pastes limited the development of residual stresses, whereas application of SC regimes extended the lifetime of the restorations.SignificanceDevelopment of residual stresses during crystallization firing in lithium silicate glass-ceramics results critical for their mechanical performance and should be therefore avoided by ensuring a homogenous cooling of the structures.     

Post-neoadjuvant strategies in breast cancer: From risk assessment to treatment escalation

The post-neoadjuvant setting in early breast cancer represents an attractive scenario for adjuvant clinical trials, offering the opportunity to test new drugs or combinations in high-risk patients who did not achieve pathologic complete response after primary treatment. No standard therapies are routinely proposed to patients with residual disease after neoadjuvant chemotherapy and few trials have explored this setting. To date, only one randomized phase III study showed the benefit of additional capecitabine after neoadjuvant chemotherapy, and international guidelines recommend at least to consider its use, particularly for triple negative breast cancer. Therefore, the management of these patients is still a clinical challenge, with limited data supporting the use of an additional adjuvant non-cross-resistant chemotherapy. Escalation strategies are currently under evaluation, with new agents proposed as supplementary post-neoadjuvant treatment (e.g. platinum salts, capecitabine, poly ADP-ribose polymerase inhibitors, immune checkpoint inhibitors, cyclin-dependent kinase 4/6 inhibitors). Based on these premises, selection criteria are critical to identify patients who may benefit from post-neoadjuvant therapies, through the validation of prognostic and predictive biomarkers for a reliable risk assessment and estimation of benefit.The present review summarizes the efforts in introducing new therapeutic options for patients with breast cancer and residual disease after neoadjuvant treatment, with a particular focus on the ongoing clinical trials and useful biomarkers for risk stratification.     

丹参川芎嗪在椎基底动脉供血不足头晕的研究

目的 探讨丹参川芎嗪对椎基底动脉供血不足头晕的影响.方法 抽取90例医院(2018年3月—2019年3月)收治的椎基底动脉供血不足头晕患者作为研究对象,根据计算机随机分组法,将90例患者分为对照组、试验组,每组45例.对照组用常规药物治疗,试验组用丹参川芎嗪注射液治疗,对比椎基底动脉血流动力学指标、血液流变学相关指标、治疗总有效率.结果 相较于对照组,试验组血流速度较高,而脉动指数较低(P<0.05);相较于对照组,试验组血液流变学相关指较低(P<0.05);相较于对照组,试验组治疗总有效率较高(P<0.05).结论 丹参川芎嗪注射液治疗椎基底动脉供血不足头晕,既可改善椎基底动脉血流动力学指标、血液流变学等相关指标,又能提高治疗总有效率.     

Interstitial lung diseases in children

Interstitial lung disease (ILD) in children (chILD) is a heterogeneous group of rare respiratory disorders that are mostly chronic and associated with high morbidity and mortality. The pathogenesis of the various chILD is complex and the diseases share common features of inflammatory and fibrotic changes of the lung parenchyma that impair gas exchanges. The etiologies of chILD are numerous. In this review, we chose to classify them as ILD related to exposure/environment insults, ILD related to systemic and immunological diseases, ILD related to primary lung parenchyma dysfunctions and ILD specific to infancy. A growing part of the etiologic spectrum of chILD is being attributed to molecular defects. Currently, the main genetic mutations associated with chILD are identified in the surfactant genes SFTPA1, SFTPA2, SFTPB, SFTPC, ABCA3 and NKX2-1. Other genetic contributors include mutations in MARS, CSF2RA and CSF2RB in pulmonary alveolar proteinosis, and mutations in TMEM173 and COPA in specific auto-inflammatory forms of chILD. However, only few genotype-phenotype correlations could be identified so far. Herein, information is provided about the clinical presentation and the diagnosis approach of chILD. Despite improvements in patient management, the therapeutic strategies are still relying mostly on corticosteroids although specific therapies are emerging. Larger longitudinal cohorts of patients are being gathered through ongoing international collaborations to improve disease knowledge and targeted therapies. Thus, it is expected that children with ILD will be able to reach the adulthood transition in a better condition.