Reflux of duodenal bile acids and abomasal ulcerations in experimental abomasal displacement in sheep

Fourteen healthy Iranian crossbred rams with the same age and weight were used to study the relationship between the reflux of duodenal bile acids and abomasal ulcerations in sheep. Rams were fed upon the same ration. The animals were randomly assigned into two equal groups of left abomasal displacement and right abomasal displacement. Before induction of abomasal displacement, ruminal and abomasal fluid samples were taken by paracentesis and the pH was recorded. Samples were centrifuged and supernatants were collected and frozen for later analysis (control samples). In each group, six sheep underwent induced abomasal displacement, and one sheep underwent exploratory laparotomy without induced abomasal displacement to provide a control for the effect of surgical stress on abomasal ulcer formation. After 4–6 days, abomasally displaced sheep showed clinical signs of abomasal displacement. After 2 weeks, the condition of animals in both groups got worse and then slaughtered. At necropsy, abomasal and ruminal fluid samples were taken and centrifuged and stored like controls. The abomasum was opened, its mucosa was examined, and the lesions and the type of ulcers were recorded. Tissue samples were also collected from each type of the lesion for histological examination. Bile acids in abomasum and rumen fluids and chloride in ruminal fluid were measured. The increase in pH and bile acids concentrations in abomasal fluid samples was well associated with abomasal ulcer formation and their severity. Significant increase in abomasal bile acids occurred after abomasal displacement in both groups (P < 0.05). This increase was significantly greater in cases which had ulcers in abomasum. Chloride concentration increased in ruminal fluid samples of both groups, which indicated the reflux of abomasal contents into the rumen (P < 0.05). It is concluded that there is a clear relationship between the increase in abomasal bile acids and ulcer formation in the abomasum.     

Clarifying the nomenclature of intervertebral disc degeneration and displacement: from bench to bedside

As a significant determinant of low back pain, intervertebral disc degeneration (IDD) has attracted more and more attention of both investigators and physicians. Disc herniation, termed as intervertebral disc displacement, is amongst the most prevalent spinal diseases closely linked with IDD. Due to the same origins and similar pathophysiology, the ambiguity regarding the similarity and difference of IDD and intervertebral disc displacement thus remains. The aim of this study was to clarify the nomenclature of IDD and disc herniation in terms of molecular etiology, pathophysiology, nature history and clinical outcomes. Collectively, IDD is a type of multifaceted, progressive spinal disease with or without clinical symptoms as back pain, characterized by extracellular matrix and the integrity of NP and AF lost, fissures formation. Disc herniation (termed as intervertebral disc displacement) is a type of spinal disease based on IDD or not, with local pain and/or sciatica due to mechanical compression and autoimmune cascades upon the corresponding nerve roots. Clarifying the nomenclature of intervertebral disc degeneration and displacement has important implications both for investigators and for physicians.     

血管内超声弹性成像中成像参数的比较研究

目的验证血管内超声弹性成像用于检测血管斑块的有效性。方法建立血管斑块的平面应变模型并生成超声仿真数据。通过一维数值优化算法获得血管径向位移分布和应变分布。通过有限元分析和迭代的方法得到血管的弹性模量分布。结果位移、应变、弹性模量3个分布图均能够检测到血管斑块,弹性模量能够提供斑块的形状大小信息,位移和应变分布图上斑块的轮廓尚不清晰。结论相对于位移和应变,弹性模量对于斑块的检测有着明显的优势,但受应变估计准确度的影响。     

Fusion of vestibular and podokinesthetic information during self-turning towards instructed targets

When observers step about their vertical axis ("active turning") without vision they dispose of essentially two sources of information that can tell them by how much they have turned: the vestibular cue which reflects head rotation in space and the "podokinesthetic" cue, a compound of leg proprioceptive afferents and efference copy signals which reflects the observer's motion relative to his support. We ask how these two cues are fused in the process leading to the perception of self-displacement during active turning. To this end we compared the performance of observers in three angular navigation tasks which differed with regard to the number and type of available motion cues: (1) Passive rotation, vestibular cue ( ves) only; observers are standing on a platform which is being rotated. (2) Treadmill stepping, podokinesthetic cue ( pod) only; observers step counter to the rotating platform so as to remain stable in space. (3) Active turning, ves and pod available; observers step around on the stationary platform. In all three tasks, angular velocity varied from trial to trial (15, 30, 60 degrees /s) but was constant during trials. Perception was probed by having the observers signal when they thought to have reached a previously instructed angular displacement, either in space or relative to the platform ("target"; range 60-1080 degrees ). Performance was quantified in terms of the targeting gain (displacement reached by the observer divided by target angle) and of the random error ( E(r)), which records an observer's deviation during single trials from his average performance. Confirming previous observations, E(r) was found to be significantly smaller during active turning than during passive turning, and we now complement these observations by showing that it is also significantly smaller than during treadmill stepping. This behaviour of E(r) is compatible with the idea that ves and pod be averaged during active turning. On the other hand, the observed characteristics of the targeting gain ( G(T)) support this idea only for the case of fast rotations (60 degrees /s); at lower velocities, the gain found during active turning was clearly not the average of the G(T) values recorded in the passive and the treadmill modes. We therefore also discuss alternative scenarios as to how ves and pod could interact, among these one based on the concept of a vestibular eigenmodel. A common denominator of these scenarios is that ves assumes the role of a prerequisite for an optimal use of pod during turning on a stationary support, without itself entering the calculation of displacement perception; this perception would be based exclusively on pod. Finally, it was a consistent observation that during passive rotations cognitive mechanisms fill in for the decaying vestibular signal in the context of the present navigation task, enabling observers to achieve large displacements surprisingly well although the duration of these movements exceeds by far the conventionally cited value of the central vestibular time constant (=20 s).     

Assessment of multiple displacement amplification for polymorphism discovery and haplotype determination at a highly polymorphic locus, MC1R

The identification of common genetic variants such as single nucleotide polymorphisms (SNPs) in the human genome has become central in human population genetics and evolution studies, as well as in the study of the genetic basis of complex traits and diseases. Crucial for the accurate identification of genetic variants is the availability of high quality genomic DNA (gDNA). Since popular sources of gDNA (buccal cells, lymphocytes, hair bulb) often do not yield sufficient quantities of DNA for molecular genetic applications, whole genome amplification methods have recently been introduced to generate a renewable source of double-stranded linear DNA. Here, we assess the fidelity of one method, multiple displacement amplification (MDA), which utilizes bacteriophage Phi29 DNA polymerase to generate amplified DNA from an original source of gDNA, in a representative SNP discovery and genetic association study at the melanocortin 1 receptor (MC1R) locus, a highly polymorphic gene in humans involved in skin and hair pigmentation. We observed that MDA has high fidelity for novel SNP discovery and can be a valuable tool in generating a potentially indefinite source of DNA. However, we observed an allele amplification bias that causes genotype miscalls at heterozygous sites. At loci with multiple polymorphic sites in linkage disequilibrium, such as at MC1R, this bias can create a significant number of heterozygote genotype errors that subsequently misrepresents haplotypes.     

Fat-free mass hydration in newborns: assessment and implications for body composition studies

Aim: Equipment (Pea Pod) offering new possibilities to assess infant body composition has recently become available and has already been used in several studies. In the Pea Pod, body density is converted to body composition using one of two models (‘Fomon’ or ‘Butte’) with different water content in fat‐free mass (hydration factor, HF). In healthy full‐term infants, we assessed HF and its biological variability in 12 newborns and calculated body composition using the two models at 1 and 12 weeks in 108 infants. Body weight and volume were assessed in Pea Pod, and body water was assessed using isotope dilution. Results: Hydration factor was 80.9% with low biological variability (0.8% of average HF). Body fat (%) was significantly lower at 1 and 12 weeks when calculated using the ‘Butte’ model than when using the ‘Fomon’ model. The difference was more pronounced at one than at 12 weeks. Conclusion: Our HF value agrees with that in the ‘Fomon’ model, its low biological variability can be reconciled with the statement that Pea Pod is accurate in newborns and ‘Fomon’ is the best available model for studies in Pea Pod.     

不同材料赋值下股骨静力学有限元模型的力学仿真分析

文题释义： 材料赋值：由于人体骨骼结构复杂,由骨膜、皮质骨和松质骨构成,并且不同骨质的材料属性差异很大,因此在很多生物力学分析过程中为了简化模型,提高分析效率,很多学者在进行生物力学仿真研究中对骨骼模型采用了不同的赋值方法。 股骨模型材料赋值：给股骨分配不同的材料属性成为建立个性化有限元模型的基本步骤,而且材料属性分配将对分析结果产生很大的影响。但是目前有关不同赋值方法对人体骨科生物力学仿真分析研究的影响还很少有全面系统的研究。 背景：不同骨质的材料属性差异很大,因此在很多生物力学分析过程中为了简化模型,提高分析效率,很多学者在进行生物力学仿真研究中对骨骼模型采用了不同的赋值方法,而材料属性分配将对生物力学分析结果产生很大的影响。 目的：采用不同的材料属性赋值方法建立3种股骨有限元模型并进行有限元仿真分析,探究不同材料赋值方法对股骨有限元生物力学仿真分析的影响。 方法：采集志愿者股骨CT扫描数据,以DICOM格式文件导入Mimics医学影像处理软件重建股骨模型,对模型分别赋予3种不同的材料属性,即均一材料赋值、皮-松质骨赋值和灰度赋值,并将模型导入有限元分析软件Abaqus 6.14中,设置相同的载荷和边界条件进行应力及位移分析。 结果与结论：①3种股骨模型的应力输出结果相差不大,且均在合理范围内;②但是均一材料赋值股骨模型与皮-松质骨赋值股骨模型的最大应力主要分布于股骨干部位,而灰度赋值股骨模型的最大应力分布在股骨颈处,这也与现实状态下股骨骨折部位主要出现于股骨颈部位所吻合;③皮-松质骨赋值模型和灰度赋值模型输出的位移值基本一致;而均一材料赋值的股骨模型位移值最小,并且与其他2种模型位移量相差40%左右;④提示灰度赋值的方法能够较好地反映人体股骨的生物力学特性,从而可以更准确地模拟真实股骨的生物力学特征,这也为骨科生物力学进行有限元仿真建模提供了重要理论依据。 ORCID: 0000-0001-5075-7333(颜继英) 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     

1切2中垂直内移测量法在高位腰椎间盘突出症经皮椎间孔镜侧路手术治疗中的应用

目的 探讨1切2中垂直内移测量法在经皮椎间孔镜侧路手术治疗高位腰椎间盘突出症(L_1/2或L_2/3)的安全性及初步疗效分析。方法 纳入山西省人民医院骨科2017年6月—2018年8月单节段高位腰椎间盘突出症的患者20例进行回顾性分析,其中男13例、女7例,年龄55～84岁、平均65.14岁;病变节段位于L_1/2者8例,L_2/3者12例。术前均采用1切2中垂直内移测量法在MRI横断面测量后,确定穿刺旁开距离和穿刺点;手术均采用经皮椎间孔镜经椎间孔入路全内镜下逐步扩大椎间孔,直视下进行神经减压。分析手术时间,术前、术后3个月、6个月分别采用VAS、ODI对患者临床表现及功能情况进行评估,总体临床疗效的评价采用MacNab评估标准。结果 20例患者手术均顺利,无输尿管和肾脏损伤及其他并发症。手术时间(72.13±23.01)min;术后伤口均愈合良好,术后第2天均佩戴腰围下地活动、适当功能锻炼,术后第3天出院。术后均获得6个月以上的随访。根据MacNab评估标准,术后疗效优14例(70%)、良5例(25%)、可1例(5%),优良率为95%。术前、术后3个月、术后6个月,VAS分别为(65.15±7.16)分、(22.02±9.64)分和(10.13±9.61)分,ODI分别为45.17%±10.54%、16.51%±8.35%和11.65%±5.93%,术后3、6个月分别与术前比较,差异均有统计学意义(P值均＜0.01)。结论 在高位腰椎间盘突出症经皮椎间孔镜侧路手术治疗中,采用1切2中垂直內移测量法定位穿刺旁开距离和穿刺点安全可靠,可以达到较好的临床效果。     

Ballistocardiogram of avian eggs determined by an electromagnetic induction coil

As an avian embryo grows within a eggshell, the whole egg is moved by embryonic activity and also by the embryonic heartbeat. A technical interest in detecting minute biological movements has prompted the development of techniques and systems to measure the cardiogenic ballistic movement of the egg or ballistocardiogram. (BCG). In this context, there is interest in using an electromagnetic induction coil (solenoid) as another simple sensor to measure the BCG and examining its possibility for BCG measurement. A small permanent magnet is attached tightly to the surface of an incubated egg, and then the egg with the magnet is placed in a solenoid. Preliminary model analysis is made to design a setup of the egg, magnet and solenoid coupling system. Then, simultaneous measurement with a laser displacement measuring system, developed previously, is made for chicken eggs, indicating that the solenoid detects the minute cardiogenic ballistic movements and that the BCG determined is a measure of the velocity of egg movements.     

带线锚钉与钢板内固定治疗肱骨大结节骨折的优劣分析

背景:手术治疗肱骨大结节骨折目前普及切开复位钢板螺钉固定,但存在着一些不足。目的:比较切开复位带线锚钉与切开复位钢板内固定治疗肱骨大结节骨折的疗效。方法:回顾性分析2016年1月至2018年12月苏州大学附属第一医院收治的肱骨大结节骨折33例患者的资料,根据内固定方式分为锚钉组(n=7)和钢板组(n=26),分别行切开复位带线锚钉和切开复位钢板螺钉内固定。统计比较2组患者手术时间、切口长度、术中失血量、术后骨折块再移位距离及术后1个月、3个月、末次随访肩关节功能Constant-Murle评分,并记录2组内固定的不良反应情况。结果与结论:①锚钉组手术时间(73.1±10.5)min短于钢板组(98.2±11.9)min,切口长度(7.3±1.1)cm小于钢板组(14.9±1.7)cm,术中失血量(45.0±7.1)m L小于钢板组(141.0±25.9)mL,差异均有显著性意义(P<0.05);②锚钉组术后骨折块再移位距离(3.0±1.8)mm大于钢板组(1.1±2.3)mm,差异有显著性意义(P<0.05);③术后1,3个月及末次随访时,2组之间Constant-Murle评分比较,差异均无显著性意义(P>0.05);④提示与切开复位钢板内固定相比,切开复位带线锚钉内固定治疗肱骨大结节骨折具有手术时间短、创伤小的优势。