角膜内皮移植术后早期玻璃酸钠对泪膜及角膜上皮细胞再生的作用

目的　研究1 g·L^-1和3 g·L^-1玻璃酸钠（hyaluronate，HA）滴眼液对角膜内皮移植术后早期泪膜及角膜上皮细胞再生的作用。方法　选择2017年9月至2018年2月在北京大学第三医院行角膜内皮移植术的患者60例（60眼），随机分成1 g·L^-1HA组和3 g·L^-1HA组，每组各30例，观察标准干眼评估问卷（SPEED）评分、结膜角膜染色评分（OSS）、泪膜破裂时间（TBUT）、角膜上皮缺损范围，进行激光共聚焦显微镜检查。比较不同时间点组间、组内各指标差异。结果　SPEED评分:各时间点两组间比较差异均无统计学意义（均为P>0.05）。组内比较:两组组内术后7 d、14 d、28 d均低于前一时间点（均为P=0.000），余相邻时间点两两比较差异均无统计学意义（均为P>0.05）。TBUT:术后7 d、14 d、28 d 3 g·L^-1HA组均显著高于1 g·L^-1HA组（均为P<0.05），而术前组间差异不显著；组内比较:1 g·L^-1 HA组后一时间点较前一时间点、3 g·L^-1HA组术后7 d较术前均显著延长(均为P<0.05)，而3 g·L^-1HA组术后14 d、28 d与前一时间点差异均无统计学意义（均为P>0.05）。 OSS评分:术前及术后1 d、3 d两组间比较差异均无统计学意义（均为P>0.05），术后7 d、14 d、28 d 3 g·L^-1HA组均显著低于1 g·L^-1HA组（均为P<0.05）；组内比较:两组术后1 d OSS评分均显著高于术前（均为P=0.000），其余时间点两组均低于前一时间点（均为P=0.000）。角膜上皮缺损范围:术后1 d 两组间比较差异均无统计学意义（均为P>0.05），术后3 d、7 d 两组间比较，以及两组组内与前一时间点比较差异均有统计学意义（均为P<0.05）。角膜基底细胞密度:术前、术后28 d两组间比较，以及1 g·L^-1HA组组内术前与术后28 d比较差异均无统计学意义（均为P>0.05），而3 g·L^-1 HA组术后28 d显著低于术前（P=0.002）。结论　HA可以有效改善角膜内皮移植术后早期泪膜状态并促进角膜上皮细胞再生，存在浓度依赖性。     

真菌性、细菌性和病毒性肺炎的若干凝血指标变化分析

探讨真菌性、细菌性和病毒性肺炎的若干凝血指标差异性研究。方法 回顾性分析2017 年7 月～2019 年11 月本院肺炎患者128 例与同期门诊健康体检者50 例，分析患者血浆纤维蛋白原（FIB）、凝血酶原时间（PT）和活化部分凝血酶时间（APTT）的水平。结果 三类肺炎组与对照组在FIB、PT 和APTT 水平比较，差异均有统计学意义（P＜0.01）；FIB、PT 水平与病原感染呈正相关，APTT 与病原感染呈负相关。结论FIB、PT、APTT 可以间接提示肺炎感染病原体类型，具有临床意义。     

Sensory evoked potentials in patients with Rett syndrome through the lens of animal studies: Systematic review

ObjectiveSystematically review the abnormalities in event related potential (ERP) recorded in Rett Syndrome (RTT) patients and animals in search of translational biomarkers of deficits related to the particular neurophysiological processes of known genetic origin (MECP2 mutations).MethodsPubmed, ISI Web of Knowledge and BIORXIV were searched for the relevant articles according to PRISMA standards.ResultsERP components are generally delayed across all sensory modalities both in RTT patients and its animal model, while findings on ERPs amplitude strongly depend on stimulus properties and presentation rate. Studies on RTT animal models uncovered the abnormalities in the excitatory and inhibitory transmission as critical mechanisms underlying the ERPs changes, but showed that even similar ERP alterations in auditory and visual domains have a diverse neural basis. A range of novel approaches has been developed in animal studies bringing along the meaningful neurophysiological interpretation of ERP measures in RTT patients.ConclusionsWhile there is a clear evidence for sensory ERPs abnormalities in RTT, to further advance the field there is a need in a large-scale ERP studies with the functionally-relevant experimental paradigms.SignificanceThe review provides insights into domain-specific neural basis of the ERP abnormalities and promotes clinical application of the ERP measures as the non-invasive functional biomarkers of RTT pathophysiology.     

A Stable Q Compensated Reverse Time Migration Method Based on Excitation Amplitude Imaging Condition

The stability and efficiency, especially the stability, are generally concerned issues in Q compensated reverse time migration (Q-RTM). The instability occurs because of the exponentially boosted high frequency ambient noise during the forward or backward seismic wavefield propagation. The regularization and low-pass filtering methods are two effective strategies to control the instability of the wave propagation in Q-RTM. However, the regularization parameters are determined experimentally, and the wavefield cannot be recovered accurately. The low-pass filtering method cannot balance the selection of cutoff frequency for varying Q values, and may damage the effective signals, especially when the signal-to-noise ratio (SNR) of the seismic data is low, the Q-RTM will be a highly unstable process. In order to achieve the purpose of stability, the selection of cutoff frequency will be small enough, which can cause great damage to the effective high frequency signals. In this paper, we present a stable Q-RTM algorithm based on the excitation amplitude imaging condition, which can compensate both the amplitude attenuation and phase dispersion. Unlike the existing Q-RTM algorithms enlarging the amplitude, the exponentially attenuated seismic wavefield will be used during both the forward and backward wavefield propagation of Q-RTM. Therefore, the new Q-RTM algorithm is relative stable, even for the low SNR seismic data. In order to show the accuracy and stability of our stable Q-RTM algorithm clearly, an example based on Graben model will be illustrated. Then, a realistic BP gas chimney model further demonstrates that the proposed method enjoys good stability and anti-noise performance compared with the traditional Q-RTM with amplitude amplification. Compare the Q-RTM images of these two models to the reference images obtained by the acoustic RTM with acoustic seismic data, the new Q-RTM results match the reference images quite well. The proposed method is also tested using a field seismic data, the result shows the effectiveness of our proposed method.     

Incidence of difficult airway situations during prehospital airway management by emergency physicians—A retrospective analysis of 692 consecutive patients

IntroductionIn the prehospital setting, advanced airway management is challenging as it is frequently affected by facial trauma, pharyngeal obstruction or limited access to the patient and/or the patient's airway. Therefore, incidence of prehospital difficult airway management is likely to be higher compared to the in-hospital setting and success rates of advanced airway management range between 80 and 99%.Methods3961 patients treated by an emergency physician in Zurich, Switzerland were included in this retrospective analysis in order to determine the incidence of a difficult airway along with potential circumstantial risk factors like gender, necessity of CPR, NACA score, GCS, use and type of muscle relaxant and use of hypnotic drugs.Results692 patients underwent advanced prehospital airway management. Seven patients were excluded due to incomplete or incongruent documentation, resulting in 685 patients included in the statistical analysis. Difficult intubation was recorded in 22 patients, representing an incidence of a difficult airway of 3.2%. Of these 22 patients, 15 patients were intubated successfully, whereas seven patients (1%) had to be ventilated with a bag valve mask during the whole procedure.ConclusionIn this physician-led service one out of five prehospital patients requires airway management. Incidence of advanced prehospital difficult airway management is 3.2% and eventual success rate is 99%, if performed by trained emergency physicians. A total of 1% of all prehospital intubation attempts failed and alternative airway device was necessary.     

Oral Everolimus for Treatment of a Giant Left Ventricular Rhabdomyoma in a Neonate—Rapid Tumor Regression Documented by Real Time 3D Echocardiography

The presented case reports on successful treatment with everolimus in a neonate with left ventricular giant rhabdomyoma. The authors used a different dosage regime compared to literature and documented rapid tumor regression by 3D echocardiography.     

Melatonin compensates silencing of heat shock protein 70 and suppresses ultraviolet radiation‐induced inflammation in human skin ex vivo and cultured keratinocytes

Melatonin, a lipophilic compound synthesized and released from the pineal gland, effectively acts against ultraviolet radiation (UVR), one of the main inducers of epidermal damage, skin cancer, inflammation, and DNA photo damage. One of the common known stress protein induced by UVR is heat shock protein 70 (Hsp70), highly expressed in human keratinocytes, providing cellular resistance to such stressors. Here, using human full‐thickness skin and normal human epidermal keratinocytes (NHEK), we investigated the interaction of melatonin and Hsp70 toward UVR‐induced inflammatory and apoptotic responses. The following observations were made: (i) UVR upregulated Hsp70 gene expression in human epidermis while melatonin significantly inverted this effect, (ii) similar patterns of regulation were observed within Hsp70 protein level, and (iii) mechanistic studies involving silencing of Hsp70 RNA (Hsp70 siRNA) showed prominent decrease of IκB‐α (an inhibitor of NF‐κB) and enhanced gene expression of pro‐inflammatory cytokines (IL‐1β, IL‐6, Casp‐1) and pro‐apoptotic protein (Casp‐3) in NHEK. Parallel investigation using melatonin (10^?3 m ) significantly inverted these responses regardless depletion of Hsp70 RNA suggesting a compensatory action of this compound in the defense mechanisms. Our findings combined with data reported so far thus enrich existing knowledge about the potent anti‐apoptotic and anti‐inflammatory action of melatonin.     

(Technically) Difficult colonoscope insertion – Tips and tricks

Cecal intubation is a critical aspect of effective, complete colonoscopy. Difficult colonoscopy is most often considered as one in which it is challenging or impossible to reach the cecum. It may be a common occurrence due to patient and/or endoscopist factors. Incomplete colonoscopies should be avoided, since patients in this context present an important prevalence of lesions that escape examination. The approach to successful cecal intubation should depend on characterization of the problem as redundant colon or difficult sigmoid colon. Most patients with a prior incomplete colonoscopy can be colonoscoped successfully, if careful attention is paid to technique, using a variety of scopes, colonoscopy methods and additional equipment. Sufficient time should be allotted to make the attempt.