Water distribution in blood during sickling of erythrocytes

Plasma urea and protein determinations proved suitable for measuring changes in total diffusible water and plasma volume in whole blood. Deoxygenation by saturation with carbon dioxide at 25 degrees C caused no change in plasma urea, but a significant increase in plasma protein concentration was induced with both normal and sickle-cell (HbSS) blood. Thus in HbSS blood there was no binding or trapping of water as a result of sickling and there was a normal influx of water into the cells (Bohr effect) despite the polymerization of the hemoglobin molecules with sickling. Consistent with this observation was the finding that the deoxygenation induced a similar increase in concentration of the plasma cations, sodium plus potassium. HbSS erythrocytes neither lost nor gained water under the more physiologic conditions of deoxygenation with a 95% nitrogen, 5% carbon dioxide gas mixture.     

Electronic phenotyping of health outcomes of interest using a linked claims-electronic health record database: Findings from a machine learning pilot project

ObjectiveClaims-based algorithms are used in the Food and Drug Administration Sentinel Active Risk Identification and Analysis System to identify occurrences of health outcomes of interest (HOIs) for medical product safety assessment. This project aimed to apply machine learning classification techniques to demonstrate the feasibility of developing a claims-based algorithm to predict an HOI in structured electronic health record (EHR) data.Materials and MethodsWe used the 2015-2019 IBM MarketScan Explorys Claims-EMR Data Set, linking administrative claims and EHR data at the patient level. We focused on a single HOI, rhabdomyolysis, defined by EHR laboratory test results. Using claims-based predictors, we applied machine learning techniques to predict the HOI: logistic regression, LASSO (least absolute shrinkage and selection operator), random forests, support vector machines, artificial neural nets, and an ensemble method (Super Learner).ResultsThe study cohort included 32 956 patients and 39 499 encounters. Model performance (positive predictive value [PPV], sensitivity, specificity, area under the receiver-operating characteristic curve) varied considerably across techniques. The area under the receiver-operating characteristic curve exceeded 0.80 in most model variations.DiscussionFor the main Food and Drug Administration use case of assessing risk of rhabdomyolysis after drug use, a model with a high PPV is typically preferred. The Super Learner ensemble model without adjustment for class imbalance achieved a PPV of 75.6%, substantially better than a previously used human expert-developed model (PPV = 44.0%).ConclusionsIt is feasible to use machine learning methods to predict an EHR-derived HOI with claims-based predictors. Modeling strategies can be adapted for intended uses, including surveillance, identification of cases for chart review, and outcomes research.     

Helicobacter pylori infection in children with recurrent abdominal pain

Helicobacter pylori was cultured and Helicobacter-like organisms (HLO) were seen in 6 (16%) of 37 children with recurrent abdominal pain. Five children had concomitant histological inflammation, but none had endoscopic changes. All 6 children demonstrated positive serology. Compared with the total group, they were more often from developing countries, larger families and lower Social groups. Treatment with phenoxymethyl penicillin and colloidal bismuth subcitrate did not result in side effects or elevated serum levels of serum bismuth. Three children demonstrated metronidazole-resistant strains and the treatment of these children remained an unsolved problem. Among the 31 H. pylori/ HLO negative children 8 (26%) demonstrated histological changes, 5 (16%) endoscopic changes and 11 (35%) had positive serology. In conclusion, pathological findings at upper gastrointestinal endoscopy are common in children with recurrent abdominal pain. Because of disconcordance between endoscopy, histology and culture, we recommend that biopsies should always be taken to clarify the diagnosis.     

Ten year maturation period in a level-I trauma center,a cohort comparison study

European Journal of Trauma and Emergency Surgery - Many changes have been made to improve trauma care. Improved trauma team response and usage of a hybrid resuscitation room are examples of how...     

调配骨水泥经皮椎体成形术注入治疗老年骨质疏松性椎体压缩骨折的疗效及其生物相容性

目的：总结经皮椎体成形术治疗老年骨质疏松性椎体压缩骨折的临床效果,并观察骨水泥材料与宿主的生物相容性反应. 方法：①患者对象：阳江市中医医院2003-02/2005-12收治的骨质疏松症性椎体压缩性骨折患者26例（32个椎体）,在C形臂X射线机透视下,行经皮椎弓根途径椎体成形术治疗.其中65岁以下的8例患者（8椎体）在硬膜外麻醉下行体位及手法复位后再行经皮椎体成形术治疗.②骨水泥注入方法及途径：调配骨水泥为英国CORIN公司生产的低黏滞度聚甲基丙烯酸甲酯,在骨水泥中加入尹索显或欧乃派克,粉∶液∶造影剂比例为3∶2∶1.应用1 mL专用注射器（美国COOK公司产品）经穿刺针将处于黏稠阶段的骨水泥注入椎体,当骨水泥达椎体后壁即停止注射.如果单侧穿刺骨水泥分布未超过椎体中线,则同时行另一侧椎弓根穿刺.③效果评估：观察椎体高度的恢复,采用目测类比评分法评估疼痛缓解程度,并发症发生情况与材料及宿主的反应. 结果：26例均完成手术进入结果分析.①每椎体注射骨水泥3.5～8.0 mL,平均4.5 mL,24 h后即离床活动.②手法复位后行经皮椎体成形术者,椎体高度椎体高度恢复到正常的75%～90%,随访≥12个月无椎体高度丢失.③术前目测类比评分为8.1（5.6～9.5）分,术后为2.7（1.2～4.8）分.23例患者腰痛术后24 h内消失,3例陈旧性骨折患者腰痛术后部分缓解.④并发骨水泥椎旁渗漏4例4椎体,未发现特殊的材料和宿主反应;前引流静脉渗漏2例2椎体,无临床症状;穿剌针抽出脑脊液1例,改行另侧穿刺成功. 结论：①经皮椎体成术治疗老年骨质疏松性椎体压缩骨折具有微创、见效快、疗效肯定的优点.②体位及手法复位后行经皮椎体成术,能大部分恢复椎体高度,适合于年龄相对较轻,椎体楔形压缩较多的患者.③只要操作熟练,单侧椎弓根穿刺即能达到临床目的.④骨水泥材料与宿主之间呈现较好的生物相容性.