Proximal External Aortic Compression for Life-Threatening Abdominal-Pelvic and Junctional Hemorrhage: An Ultrasonographic Study in Adult Volunteers

Introduction: Following life-threatening junctional trauma, the goal is to limit blood loss while expediting transfer to operative rescue. Unfortunately, life-threatening abdominal-pelvic or junctional hemorrhage is often not amenable to direct compression and few temporizing strategies are available beyond hemostatic dressings, hypotensive resuscitation, and balanced transfusion. Objectives: In this study, we evaluated proximal external aortic compression to arrest blood flow in healthy adult men. Methods: This was a simulation trial of proximal external aortic compression, for life-threatening abdominal-pelvic and junctional hemorrhage, in a convenience sample of healthy adult male volunteers. The primary end points were cessation of femoral blood flow as assessed by pulse wave Doppler ultrasound at the right femoral artery, caudal to the inguinal ligament. Secondary end points were discomfort and negative sequelae. Results: Aortic blood flow was arrested in 12 volunteers. Median time to blood flow cessation was 12.5?seconds. Median reported discomfort was 5 out of 10. No complications or negative sequelae were reported. Conclusion: This trial suggests that it may be reasonable to attempt temporization of major abdominal-pelvic and junctional hemorrhage using bimanual proximal external aortic compression. In the absence of immediate alternatives for this dangerous and vexing injury pattern, there appear to be few downsides to prehospital proximal external aortic compression while concomitantly expediting definite care.     

Antigen-dependent effects of divergent selective breeding based on natural antibodies on specific humoral immune responses in chickens

NAb are defined as antigen binding antibodies present without a known previous exposure to this antigen. NAb are suggested to enhance specific antibody (SpAb) responses, but consequences of different NAb levels on immunization are largely unknown. Layer chickens were divergently selected and bred for keyhole limpet hemocyanin (KLH)-binding NAb titers, resulting in a High line and a Low line. In this study, we investigated: (1) the relation of NAb levels with SpAb titers; and (2) the effect of immunization on NAb titers. The 50 highest females of the High line and the 50 lowest females of the Low line of generation 2 were intramuscularly immunized at 33 weeks of age with 1 mL phosphate buffered saline (PBS) containing one of four treatments: (1) negative control (no antigen), (2) 500 µg KLH, (3) 100 µg avian tuberculin purified protein derivative of Mycobacterium avium (PPD), or (4) 250 µg human serum albumin (HuSA). IgM and IgG titers of NAb and SpAb in plasma were determined prior to immunization and weekly for 5 weeks post immunization by indirect ELISA. In addition, antibody affinity was investigated. No differences in SpAb and NAb response against KLH and PPD were observed as a consequence of different NAb titers, but increased and prolonged SpAb and NAb titer responses against HuSA were observed for the High line compared to the Low line. Different natural antibody titers did not impair SpAb dynamics and SpAb affinity. NAb titers were not, or for only short-term, affected by immunization. We show here that NAb may enhance SpAb responses, but that this effect is antigen-dependent. We hypothesize that NAb play a role in general disease resistance through enhancement of the humoral adaptive immune response.     

Development and evaluation of RapTAT: A machine learning system for concept mapping of phrases from medical narratives

Rapid, automated determination of the mapping of free text phrases to pre-defined concepts could assist in the annotation of clinical notes and increase the speed of natural language processing systems. The aim of this study was to design and evaluate a token-order-specific naïve Bayes-based machine learning system (RapTAT) to predict associations between phrases and concepts. Performance was assessed using a reference standard generated from 2860 VA discharge summaries containing 567,520 phrases that had been mapped to 12,056 distinct Systematized Nomenclature of Medicine – Clinical Terms (SNOMED CT) concepts by the MCVS natural language processing system. It was also assessed on the manually annotated, 2010 i2b2 challenge data. Performance was established with regard to precision, recall, and F-measure for each of the concepts within the VA documents using bootstrapping. Within that corpus, concepts identified by MCVS were broadly distributed throughout SNOMED CT, and the token-order-specific language model achieved better performance based on precision, recall, and F-measure (0.95 ± 0.15, 0.96 ± 0.16, and 0.95 ± 0.16, respectively; mean ± SD) than the bag-of-words based, naïve Bayes model (0.64 ± 0.45, 0.61 ± 0.46, and 0.60 ± 0.45, respectively) that has previously been used for concept mapping. Precision, recall, and F-measure on the i2b2 test set were 92.9%, 85.9%, and 89.2% respectively, using the token-order-specific model. RapTAT required just 7.2 ms to map all phrases within a single discharge summary, and mapping rate did not decrease as the number of processed documents increased. The high performance attained by the tool in terms of both accuracy and speed was encouraging, and the mapping rate should be sufficient to support near-real-time, interactive annotation of medical narratives. These results demonstrate the feasibility of rapidly and accurately mapping phrases to a wide range of medical concepts based on a token-order-specific naïve Bayes model and machine learning.     

Recent trends in barbiturate detection in medicolegal deaths

A study was undertaken of 51 cases where barbiturates were detected in post-mortem blood samples from 2000 to 2019 at Forensic Science South Australia, Adelaide, Australia. The cause of death was drug toxicity in only 27 (53%) (M:F = 19:8; age range 19-74yrs, mean 46yrs). In 17 cases, barbiturate toxicity was the primary cause of death, 14 due to pentobarbitone and 3 to phenobarbitone. All were suicides. Barbiturates were obtained by online purchase from overseas sources in 9 cases (33%), and through veterinary practice in 2 cases (7%). Drug toxicity deaths where barbiturates were detected rose from 1 in 2000–2004 to 11 in 2015–2019, and those where deaths were primarily due to barbiturate toxicity rose from 1 in 2000–2004 to 9 in 2015–2019. However, the mere detection of barbiturates in post mortem samples did not equate with illicit use, as 23 of the deaths (45%) were due to natural causes in individuals prescribed barbiturates for epilepsy. The usefulness of examining subset populations separate from accrued national data is also demonstrated in the significantly younger age of decedents in South Australia dying from deliberately administered barbiturates (46 yrs) compared to the national average of 57.9 yrs. The reasons for this difference will require further investigation as this may impact upon local suicide prevention strategies.     

股骨近端不同平面皮质骨厚度值、X射线灰度值与女性髋部脆性骨折的相关性

文题释义：脆性骨折：是指在无创伤或较微创伤情况下引起的骨折，一般是指在平地或人体站立高度下活动过程中发生的骨折，X射线下常可见骨骼有骨质疏松征象，也称为骨质疏松性骨折。 髋部骨折：是指发生在髋部及周围的骨折，包括股骨颈骨折、股骨转子间骨折、转子间骨折及髋臼骨折等，是骨质疏松性骨折最常发生的骨折部位，患者常因高龄且伴有基础疾病而1年内死亡率可达50%，5年存活率为20%。 背景：随着人口老龄化，脆性骨折疾病受到临床越来越多的关注，骨密度值的单独使用已经不能满足临床对脆性骨折的风险评估。目前骨皮质厚度作为评估脆性骨折发生风险的新方向和新方法之一，受到越来越多学者的研究和讨论。 目的：探讨在X射线DR摄影下，股骨近端不同平面骨皮质厚度值、X射线灰度值与50岁以上女性髋部脆性骨折的相关性，以此探寻股骨近端不同平面中，用于预测女性髋部脆性骨折发生风险最合适的测量平面。 方法：依照纳入标准收集2018年7月至2019年6月在广西医科大学第九附属医院放射科行X射线DR骨盆正位片检查的50岁以上女性患者100例的相关临床资料。所有患者对试验方案均知情同意，且得到医院伦理委员会批准。股骨近端骨皮质厚度值的测量平面设计为股骨颈中段、小转子上1 cm以内和小转子下1 cm以内，共3个测量平面。X射线灰度值测量以大转子和小转子的中点连线作为矩形对角线取矩形区域测量。 结果与结论：①50-64岁年龄组记为A组，65岁及以上年龄组记为B组，每组各50例；② B组患者的小转子上1 cm以内和小转子下1 cm以内平面的骨皮质厚度值、X射线灰度值比A组低，骨折率比A组高，差异均有显著性意义(P < 0.05)；而股骨颈中段平面的骨皮质厚度值2组间比较差异无显著性意义(P > 0.05)；③骨皮质厚度值的测量平面比较，骨皮质厚度测量值在整体上由高到低依次为小转子下1 cm以内、小转子上1 cm以内和股骨颈中段平面，差异有显著性意义(P < 0.05)；④观察对象小转子下1 cm以内及小转子上1 cm以内骨皮质厚度值、X射线灰度值、年龄，与脆性骨折相关系数依次为-0.303，-0.205，-0.272及0.346(P < 0.05)，但股骨颈中段平面皮质骨厚度与脆性骨折无明显相关性(P > 0.05)；⑤A组中骨折和非骨折患者小转子上1 cm以内和小转子下1 cm以内测量平面的骨皮质厚度值比较差异有显著性意义(P < 0.05)；B组中骨折和非骨折患者各指标比较差异均无显著性意义(P > 0.05)；在50岁以上的所有患者中，骨折和非骨折患者各测量平面的骨皮质厚度值和X射线灰度值的比较差异均有显著性意义(P < 0.05)；⑥说明骨皮质厚度值变薄，X射线灰度值变小，则髋部脆性骨折可能性变高。利用股骨近端骨皮质厚度评估50岁以上女性髋部脆性骨折风险时，推荐在股骨小转子下1 cm以内平面进行测量。 ORCID: 0000-0003-1961-7468(覃海阔) 中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程     

Influence of natural weathering on colour stability of materials used for facial prosthesis

Colour stability of resin and silicone is an important factor for longevity of facial prostheses. The aim of this study was to evaluate the colour stability of resins and silicone for facial prostheses. Three brands of acrylic resin and one of facial silicone were evaluated considering pigment incorporation for the colourless materials. Ten samples of each material were fabricated and submitted to measurements of chromatic alteration initially and after 90 and 180 days of weathering natural through visual analysis and spectrophotometry. Data were evaluated by ANOVA and Tukey test (p < 0.05). Statistically significant colour alteration was observed among some materials regardless of the period. The materials did not present a statistical difference between 90 and 180 days except for the pigmented heat-polymerized resin. The colour difference between pigmented Silastic MDX4-4210 and colourless Silastic was statistically significant (p < 0.01) in both periods as well as between pigmented and colourless heat-polymerized resin, and between the resins Rapidaflex and Lentaflex. The visual method demonstrated colour alteration in all materials evaluated during the first 90 days of ageing. All materials exhibited colour alteration due to exposure to environment.     

GNE myopathy: A prospective natural history study of disease progression

Mutations in the glucosamine (UDP-N-acetyl)-2-epimerase/N-acetylmannosamine kinase gene cause GNE myopathy, a mildly progressive autosomal recessive myopathy. We performed a prospective natural history study in 24 patients with GNE myopathy to select evaluation tools for use in upcoming clinical trials. Patient clinical conditions were evaluated at study entry and one-year follow-up. Of the 24 patients, eight (33.3%) completed a standard 6-min walk test without assistance. No cardiac events were observed. Summed manual muscle testing of 17 muscles, grip power, and percent force vital capacity (%FVC) were significantly reduced (p < 0.05), and scores for 6-min walk test and gross motor function measure were decreased (p < 0.1) after one year. The decrement in %FVC was significant among non-ambulant patients, whereas the decrement in grip power tended to be greater among ambulant patients. The 6-min walk test, gross motor function measure, manual muscle testing, grip power, and %FVC reflect annual changes and are thus considered good evaluation tools for clinical trials.