Osmotic reversal induces assembly of tight junction strands at the basal pole of toad bladder epithelial cells but does not reverse cell polarity

Summary This paper reports the effect of reversing the osmotic environment between luminal and serosal compartments of a toad urinary bladder on the polarity of assembly of tight junction strands. Toad bladders were filled with Ringer's solution (220 mOsm) and were immersed in distilled water at room temperature or at 37°C. Within two minutes, new tight junction strands are assembled. The new tight junctional strands unite the basal pole of epithelial cells with the apical side of basal cells. Physiological studies show that oxytocin, a synthetic analog of antidiuretic hormone, is still capable of inducing increases in water transport in epithelia which were osmotically reversed. This capacity decreases significantly for longer periods of osmotic reversal. Osmotic reversal does not alter the original polarity of epithelial cells: 1) the apical tight junction belt, at the apical pole, is not displaced; 2) the freeze-fracture morphology typical of apical plasma membrane (particle-rich E faces; particle-poor P faces) is not altered; 3) oxytocin and cyclic AMP induce aggregates which are observed only at the apical plasma membrane. Massive assembly of junctional elements occurs even in epithelia preincubated in the presence of cycloheximide (an inhibitor of protein synthesis) or of cytoskeleton perturbers. Our experiments show that the polarity of assembly of tight junction strands depends on the vectorial orientation of the osmotic environment of the epithelium.     

Anabolic effect of genistein and genistin on bone metabolism in the femoral-metaphyseal tissues of elderly rats: The genistein effect is enhanced by zinc

The effect of genistein and genistin on bone components in the femoral-metaphyseal tissues obtained from elderly female rats was investigated in vitro. The metaphyseal tissues were cultured for 24 h in a medium containing either vehicle, genistein (10^-8-10^-5 M) or genistin (10^-7-10^-5 M). The presence of genistein or genistin caused a significant increase in alkaline phosphatase activity, deoxyribonucleic acid (DNA) and calcium contents in the metaphyseal tissues. The effect of genistein was greater than that of genistin. The bone components increased by genistein (10^-5 M) or genistin (10^-5 M) were completely blocked by the presence of cycloheximide (10^-6 M). The presence of zinc sulfate (10^-5 M) caused a significant increase in the genistein (10^-5 M)-elevated alkaline phosphatase activity, DNA and calcium contents. The enhancement with zinc was not seen by genistin (10^-5 M). The stimulatory effect of zinc on the genistein-induced increase in bone components of the metaphyseal tissues was completely blocked by the presence of cycloheximide (10^-6 M). The present results suggest that genistein and genistin have an anabolic effect on bone metabolism in the femoral-metaphyseal tissues of elderly rats, and that the genistein effect is enhanced by zinc, an essential trace element.     

Estimation of conditions evoking fracture in finger bones under pinch loading based on finite element analysis

A finger finite element (FE) model was created from CT images of a Japanese male in order to obtain a shape-biofidelic model. Material properties and articulation characteristics of the model were taken from the literature. To predict bone fracture and realistically represent the fracture pattern under various loading conditions, the ESI-Wilkins-Kamoulakos rupture model in PAM-CRASH (ESI Group S.A., Paris, France) was utilized in this study with parameter values of the rupture model determined by compression testing and simulation of porcine fibula. A finger pinch simulation was then conducted to validate the finger FE model. The force-displacement curve and fracture load from the pinch simulation was compared to the result of finger pinch test using cadavers. Simulation results are coincident with the test result, indicating that the finger FE model can be used in an analysis of finger bone fracture during pinch accident. With this model, several pinch simulations were conducted with different pinching object’s stiffness and pinching energy. Conditions for evoking finger bone fracture under pinch loading were then estimated based on these results. This study offers a novel method to predict possible hazards of manufactured goods during the design process, thus finger injury due to pinch loading can be avoided.     

MIPO技术结合锁定加压钢板、顺行交锁髓内钉及锁定加压钢板治疗肱骨干中段骨折疗效的对比研究

摘要 目的：探讨微创经皮钢板内固定（MIPO）技术结合锁定加压钢板、顺行交锁髓内钉、锁定加压钢板治疗肱骨干中段骨折的疗效。方法：选择2016年2月至2019年2月我院收治的126例肱骨干中段骨折患者，采用随机数字表法将其分为三组，MIPO组（42例）采用MIPO技术结合锁定加压钢板固定治疗，髓内钉组（42例）采用顺行交锁髓内钉固定治疗，钢板组（42例）采用锁定加压钢板固定治疗。所有患者术后随访12个月，比较三组手术时间、术中出血量、术后住院时间、骨折愈合时间、术前和术后第12个月美国加州大学肩关节评分系统（UCLA）评分、Mayo肘关节功能评分（MEPS）、欧洲五维健康量表(EQ-5D)评分以及并发症发生率。结果：MIPO组和髓内钉组的术中出血量与术后住院时间均少于钢板组（P＜0.05），MIPO组和髓内钉组之间无统计学差异（P＞0.05）。MIPO组、钢板组骨折愈合时间短于髓内钉组（P＜0.05），MIPO组、钢板组之间无统计学差异（P＞0.05）。MIPO组、钢板组术后第12个月UCLA评分均高于髓内钉组（P＜0.05），MIPO组、钢板组之间无统计学差异，第12个月MEPS无差异（P＞0.05）。术后第12个月MIPO组、钢板组EQ-5D评分高于髓内钉组（P＜0.05），MIPO组、钢板组之间无统计学差异（P＞0.05）。三组桡神经损伤、肩峰损伤发生率相比较，差异有统计学意义（P＜0.05），桡神经损伤以钢板组发生率最高，肩峰损伤以髓内钉组发生率最高。结论：MIPO技术结合锁定加压钢板具有微创、术后恢复快、对肩关节功能及生活质量的影响较小、术后并发症较少的优势，是肱骨干中段骨折较为理想的治疗方式。     

eXaSkin: A novel high-density bolus for 6MV X-rays radiotherapy

PurposeTo evaluate eXaSkin, a novel high-density bolus alternative to commercial tissue-equivalent Superflab, for 6MV photon-beam radiotherapy.Materials and methodsWe delivered a 10 × 10 cm² open field at 90° and head-and-neck clinical plan, generated with the volumetric modulated arc therapy (VMAT) technique, to an anthropomorphic phantom in three scenarios: with no bolus on the phantom’s surface, with Superflab, and with eXaSkin. In each scenario, we measured dose to a central planning target volume (PTV) in the nasopharynx region with an ionization chamber, and we measured dose to the skin, at three different positions within the vicinity of a neck lymph node PTV, with MOSkin™, a semiconductor dosimeter. Measurements were compared against calculations with the treatment planning system (TPS).ResultsFor the static field, MOSkin results underneath the eXaSkin were in agreement with calculations to within 1.22%; for VMAT, to within 5.68%. Underneath Superflab, those values were 3.36% and 11.66%. The inferior agreement can be explained by suboptimal adherence of Superflab to the phantom’s surface as well as difficulties in accurately reproducing its placement between imaging and treatment session. In all scenarios, dose measured at the central target agreed to within 1% with calculations.ConclusionseXaSkin was shown to have superior adaptation to the phantom’s surface, producing minimal air gaps between the skin surface and bolus, allowing for accurate positioning and reproducibility of set-up conditions. eXaSkin with its high density material provides sufficient build-up to achieve full skin dose with less material thickness than Superflab.     

Anemia: ¿cuál es su relación con el síndrome de fragilidad en el anciano?

Anaemia is often unexpectedly found, or in a context of investigations into a chest pain, dyspnoea, or weakness. This disorder can be considered an indicator of health status in elderly patients, and has been related to the frailty syndrome. A systematic review was conducted on the studies published in PubMed and Google Scholar databases in the period from January 1999 to May 2019. The search was limited to those studies published regarding anaemia and its relationship to the frailty syndrome. Anaemia seems to be part of the immunosenescence process that can explain frailty syndrome in association with other metabolism, endocrine, and inflammatory disorders. It was unable to be determined if anaemia is responsible for frailty or a result of it.     

Clinical application of a gantry-attachable plastic scintillating plate dosimetry system in pencil beam scanning proton therapy beam monitoring

PurposeThe entrance beam fluence of therapeutic proton scanning beams can be monitored using a gantry-attachable plastic scintillating plate (GAPSP). This study evaluated the clinical application of the GAPSP using a method that measures intensity modulated proton therapy (IMPT) beams for patient treatment.MethodsIMPT beams for the treatment of nine patients, at sites that included the spine, head and neck, pelvis, and lung, were measured using the GAPSP, composed of an EJ-212 plastic scintillator and a CMOS camera. All energy layers distinguished by the GAPSP were accumulated to determine the dose distribution of the treatment field. The evaluated fields were compared with reference dose maps verified by quality assurance.ResultsComparison of dose distributions of evaluation treatment fields with reference dose distributions showed that the 3%/1 mm average gamma passing rate was 96.4%, independent of the treatment site, energy range and field size. When dose distributions were evaluated using the same criteria for each energy layer, the average gamma passing rate was 91.7%.ConclusionsThe GAPSP is a suitable, low-cost method for monitoring pencil beam scanning proton therapy, especially for non-spot scanning or additional collimation. The GAPSP can also estimate the treatment beam by the energy layer, a feature not common to other proton dosimetry tools.     

老年低肌肉含量人群肾功能及肠道菌群变化

目的分析肾功能指标水平及肠道菌群分布对老年人群肌肉含量降低的影响,以期为提高老年人群肌肉含量提供新的思路。方法选取2017年6月至2019年6月于我院行生物电阻抗(BIA)检测的452例老年人为研究对象,根据BIA检测结果分别将男性和女性中BIA水平较低的前25%的对象作为低肌肉含量组(观察组),另外75%的对象作为肌肉含量正常组(对照组),采用全自动生化分析仪测定各组受试者尿微量白蛋白/肌酐(UACR)及肾小球滤过率(eGFR),采用实时荧光定量聚合酶链反应(FQ-PCR)法检测粪便标本中菌群数量。结果观察组对象eGFR水平低于对照组(男性:t=6.543,P0.001;女性:t=5.700,P0.001)、UACR高于对照组(男性:t=5.543,P0.001;女性:t=4.995,P0.001)。观察组中男性受试者肠道普拉梭菌、乳杆菌、双歧杆菌、梭菌属Ⅰ族数量低于对照组(t=8.952、12.971、10.142、26.072,均P0.001)。观察组中女性受试者肠道普拉梭菌、乳杆菌、双歧杆菌数量低于对照组(t=11.040、11.570、10.840,均P0.001),而梭菌属Ⅰ族数量高于对照组(t=31.941,P0.001)。结论老年人群肾功能受损及肠道菌群数量改变可能造成营养不良而导致肌肉含量降低。