Mechanical Hemolysis Complicating Transcatheter Interventions for Valvular Heart Disease: JACC State-of-the-Art Review

Mechanical intravascular hemolysis is frequently observed following procedures on heart valves and uncommonly observed in native valvular disease. In most cases, its severity is mild. Nevertheless, it can be clinically significant and even life threatening, requiring multiple blood transfusions and renal replacement therapy. This paper reviews the current knowledge on mechanical intravascular hemolysis in valvular disease, before and after correction, focusing on pathophysiology, approach to diagnosis, and impact of other hematological conditions on the resultant anemia. The importance of a multidisciplinary management is underscored. Laboratory data are provided about subclinical hemolysis that is commonly observed following the implantation of surgical and transcatheter valve prostheses and devices. Finally, clinical scenarios are reviewed and current medical and surgical treatments are discussed, including alternative options for inoperable patients.     

种植手术同期根向复位瓣附着龈重建的临床研究

目的探索一种简单高效的手术方法,用于增加种植体周围的附着龈宽度并且能缩短种植修复的疗程。探讨根向复位瓣附着龈重建术的效果。方法收集有种植修复需求的患者8例,但种植位点处附着龈宽度小于2 mm,行种植手术同期利用根向复位瓣技术进行附着龈重建。术后2周拆线。8周后常规种植上部修复并负荷。分别观察手术前、术后8周、修复完成即刻、修复完成1年时附着龈宽度的变化情况。结果所有患者种植体周围的附着龈宽度明显增加,修复完成1年后未见明显附着龈退缩。术后2周拆线,除1个种植位点在术后第2天因缝合线脱落致黏膜仍有炎症外,其余位点黏膜愈合良好。结论根向复位瓣附着龈重建术创伤小,并且同期种植手术可以缩短种植修复疗程,术后患者恢复效果较好。可以作为增加种植体周围附着龈宽度的简单高效的方法。     

红细胞分布宽度与急性胰腺炎严重程度的研究

目的研究外周血红细胞分布宽度(RDW)对急性胰腺炎AP严重程度评估的价值。方法收集2017年1月-2019年3月在首都医科大学大兴医院收治的急性胰腺炎(AP)患者266例,按疾病严重程度分为重症急性胰腺炎(SAP)组、中重症急性胰腺炎(MSAP)组、轻症急性胰腺炎(MAP),并纳入相同例数的健康体检者作为对照组,收集患者的一般资料及RDW进行统计分析。结果急性胰腺炎(AP)组与对照组之间RDW差异具有有统计学意义(P<0.05);SAP患者的RDW水平明显高于非SAP患者;RDW(P <0.05,OR=3.378)是急性胰腺炎的一项独立危险因素;ROC曲线预测AP及SAP曲线下面积分别为0.712及0.840。结论 RDW水平是评估急性胰腺炎严重程度及预后的一项有效指标。     

Investigation of factors associated with ABCB5-positive limbal stem cell isolation yields from human donors

PurposeTo identify factors associated with isolation yields of ATP-binding cassette (ABC) superfamily member B5 (ABCB5)-positive limbal stem cells (LSCs) from human cadaveric donor eyes.MethodsWhole eye globes were obtained from the Saving Sight eye bank, Kansas City, MO and the CorneaGen eye bank, Seattle, WA. ABCB5-positive LSCs were sorted by flow cytometry upon anti-ABCB5 monoclonal antibody staining within one week after donor death. The yields of live limbal epithelial cells in their entirety and of isolated pure ABCB5-positive LSC subsets were correlated with variables contained in the eye donors’ medical information.ResultsThe mean isolation yield of live limbal epithelial cells and ABCB5-positive LSCs per donor eye was (340,000 ± 160,000 and 2,608 ± 1,842 respectively, mean ± SD). Stepwise regression analysis showed that cardiac disease-related death was the strongest negative predictor of the ABCB5-positive LSC isolation yield (p = 0.01). While we observed a trend for an age-related decline in the yield of ABCB5-positive LSCs, a statistically significant association could not be established (2% decrease/year, p = 0.11). Additionally, despite a trend for decreased isolation yields of total live limbal epithelial cells isolated from single donors with a longer time between death and tissue processing (p = 0.04), this did not affect the yields of purified ABCB5-positive LSC, which was independent of increasing time between death and tissue processing (p = 0.50).ConclusionsOur study identifies cardiac disease-related death as a donor variable significantly associated with lower ABCB5-positive LSC isolation yields.     

Diagnostic and prognostic value of red blood cell distribution width in sepsis: A narrative review

Previous studies showed that red blood cell distribution width (RDW) can be used as a prognostic and diagnostic index in various non-hematological diseases, including severe infections and sepsis. Here, we provide a narrative review to summarize the findings of available studies investigating the relationship between RDW and sepsis. Current evidence suggests that increased RDW on admission, both in adults and neonates, may be associated with unfavorable outcomes on the short- and long-term. In patients with suspected sepsis, RDW has modest value for predicting positive blood culture. Accordingly, its diagnostic value for sepsis seems limited, whilts dynamic changes of RDW are associated with outcome of sepsis. Taken together, these results suggest that RDW could be used as a prognostic index in septic patients.     

Neural selectivity,efficiency, and dose equivalence in deep brain stimulation through pulse width tuning and segmented electrodes

BackgroundAchieving deep brain stimulation (DBS) dose equivalence is challenging, especially with pulse width tuning and directional contacts. Further, the precise effects of pulse width tuning are unknown, and recent reports of the effects of pulse width tuning on neural selectivity are at odds with classic biophysical studies.MethodsWe created multicompartment neuron models for two axon diameters and used finite element modeling to determine extracellular influence from standard and segmented electrodes. We analyzed axon activation profiles and calculated volumes of tissue activated.ResultsWe find that long pulse widths focus the stimulation effect on small, nearby fibers, suppressing distant white matter tract activation (responsible for some DBS side effects) and improving battery utilization when equivalent activation is maintained for small axons. Directional leads enable similar benefits to a greater degree. Reexamining previous reports of short pulse stimulation reducing side effects, we explore a possible alternate explanation: non-dose equivalent stimulation may have resulted in reduced spread of neural activation. Finally, using internal capsule avoidance as an example in the context of subthalamic stimulation, we present a patient-specific model to show how long pulse widths could help increase the biophysical therapeutic window.DiscussionWe find agreement with classic studies and predict that long pulse widths may focus the stimulation effect on small, nearby fibers and improve power consumption. While future pre-clinical and clinical work is necessary regarding pulse width tuning, it is clear that future studies must ensure dose equivalence, noting that energy- and charge-equivalent amplitudes do not result in equivalent spread of neural activation when changing pulse width.     

Coronary Artery Lumen Segmentation Using Location–Adaptive Threshold in Coronary Computed Tomographic Angiography: A Proof-of-Concept

ObjectiveTo compare the lumen parameters measured by the location-adaptive threshold method (LATM), in which the inter- and intra-scan attenuation variabilities of coronary computed tomographic angiography (CCTA) were corrected, and the scan-adaptive threshold method (SATM), in which only the inter-scan variability was corrected, with the reference standard measurement by intravascular ultrasonography (IVUS).Materials and MethodsThe Hounsfield unit (HU) values of whole voxels and the centerline in each of the cross-sections of the 22 target coronary artery segments were obtained from 15 patients between March 2009 and June 2010, in addition to the corresponding voxel size. Lumen volume was calculated mathematically as the voxel volume multiplied by the number of voxels with HU within a given range, defined as the lumen for each method, and compared with the IVUS-derived reference standard. Subgroup analysis of the lumen area was performed to investigate the effect of lumen size on the studied methods. Bland-Altman plots were used to evaluate the agreement between the measurements.ResultsLumen volumes measured by SATM was significantly smaller than that measured by IVUS (mean difference, 14.6 mm³; 95% confidence interval [CI], 4.9–24.3 mm³); the lumen volumes measured by LATM and IVUS were not significantly different (mean difference, −0.7 mm³; 95% CI, −9.1–7.7 mm³). The lumen area measured by SATM was significantly smaller than that measured by LATM in the smaller lumen area group (mean of difference, 1.07 mm²; 95% CI, 0.89–1.25 mm²) but not in the larger lumen area group (mean of difference, −0.07 mm²; 95% CI, −0.22–0.08 mm²). In the smaller lumen group, the mean difference was lower in the Bland-Altman plot of IVUS and LATM (0.46 mm²; 95% CI, 0.27–0.65 mm²) than in that of IVUS and SATM (1.53 mm²; 95% CI, 1.27–1.79 mm²).ConclusionSATM underestimated the lumen parameters for computed lumen segmentation in CCTA, and this may be overcome by using LATM.