A Coarse-to-Fine Framework for Automated Knee Bone and Cartilage Segmentation Data from the Osteoarthritis Initiative

Journal of Digital Imaging - Knee osteoarthritis (OA) is a degenerative joint disease that is prevalent in advancing age. The pathology of OA disease is still unclear, and there are no effective...     

骨性关节炎对膝关节软骨力学性质影响的实验研究

目的 研究正常国人新鲜尸体膝关节软骨和骨性关节炎膝关节软骨的生物力学性质,为临床提供生物力学参数。方法 取正常和病变的膝关节软骨在ShimadzuAUTOGRAPH电子万能试验机上进行一维拉伸实验。结果 得出了关节软骨最大载荷、伸长比、应力、应变等数据;用最小二乘法处理应力鄄应变数据,得出了其应力鄄应变关系表达式,拟合出了应力鄄应变曲线。结论 病变组各项力学性质指标均明显低于正常组。     

骨性关节炎对膝关节软骨粘弹性影响实验研究

研究了正常国人新鲜尸体膝关节软骨和骨性关节炎膝关节软骨的粘弹性力学性质.对正常和病态膝关节软骨进行一维拉伸应力松弛、蠕变实验,得出了应力松弛、蠕变实验数据和曲线,以回归分析的方法处理应力松弛、蠕变实验数据,得出了归一化应力松弛函数、归一化蠕变函数表达式.以冯元桢教授的准线性理论得出了正常组和病态组膝关节软骨松弛函数表达式,并对实验结果进行了分析讨论.     

Inaccurate Estimation of Body Weight Prior to Smoking Cessation: Implications for Quitting and Weight Gain1

Weight gain following smoking cessation has been found to hinder successful quitting. This preliminary investigation evaluated participants' ability to accurately estimate their body weight prior to attempting to quit smoking. The subjects were 51 adults (18 females and 33 males) with a mean age of 31 years. Subjects were asked to give their most accurate estimated weight in pounds just prior to obtaining their actual weight. The results indicated that subjects underestimated their weight by 3.5 lbs (1.59 kg). Two-thirds of the subjects underestimated their weight by an average of 6.6 lbs (2.99 kg). These findings suggest that obtaining an accurate body weight prior to smoking cessation may lead to a more accurate perception of subsequent weight change and facilitate successful quitting.     

The Combined Effect of Frontal Plane Tibiofemoral Knee Angle and Meniscectomy on the Cartilage Contact Stresses and Strains

Abnormal tibiofemoral alignment can create loading conditions at the knee that may lead to the initiation and progression of knee osteoarthritis (OA). The degenerative changes of the articular cartilage may occur earlier and with greater severity in individuals with abnormal frontal plane tibiofemoral alignment who undergo a partial or total meniscectomy. In this investigation, subject specific 3D finite element knee models were created from magnetic resonance images of two female subjects to study the combined effect of frontal plane tibiofemoral alignment and total and partial meniscectomy on the stress and strain at the knee cartilage. Different amounts of medial and lateral meniscectomies were modeled and subject specific loading conditions were determined from motion analysis and force platform data during single-leg support. The results showed that the maximum stresses and strains occurred on the medial tibial cartilage after medial meniscectomy but a greater percentage change in the contact stresses and strains occurred in the lateral cartilage after lateral meniscectomy for both subjects due to the resultant greater load bearing role of the lateral meniscus. The results indicate that individual’s frontal plane knee alignment and their unique local force distribution between the cartilage and meniscus play an important role in the biomechanical effects of total and partial meniscectomy.     

Body Weight in Mouse Embryos Specifies Staging of Tooth Development

Great intra- and interlitter variation in morphological stages is known to exist among mouse embryos of the same strain at a similar chronological stage. With the aim of searching for an easily measurable parameter that correlates well with tooth development, the morpho- and histodifferentiation of teeth were compared in embryos classified according to the embryonic day (ED) specified by wet body weight. The embryos and fetuses were harvested at 12-h intervals from ED12.5 until birth, weighed, fixed, and processed histologically. The tooth age was determined according to the developmental progress of the first molar, evaluated based on morpho- and histodifferentiation criteria. The data documented a better correlation between tooth morpho-histodifferentiation with the age/weight staging than with only the embryonic day. The cytodifferentiation of odontoblasts exhibited a high interlitter variability and was similar within specimens of the same litter, regardless of their body weight differences.     

SOX Trio Decrease in the Articular Cartilage with the Advancement of Osteoarthritis

SOX trio (SOX-5, SOX-6, and SOX-9) maintain the chondrocytic phenotypes and are vital for chondrogenesis in embryonic development. The purpose of this study is to investigate the change in the expression of SOX trio with the advancement of osteoarthritis (OA) in human articular cartilage (AC). Human OA samples from eight patients were obtained from the distal femoral condyles during total knee arthroplasty. Minimally OA cartilage taken from areas with no obvious surface defects on lateral condyles was compared with advanced OA cartilage obtained from areas within 1 cm of overt lesion located on medial condyle surface. SOX-5, SOX-6, and SOX-9 gene expressions significantly decreased by 41% (p = 0.047), 46% (p = 0.047), and 56% (p = 0.029) in advanced OA area compared with the minimally OA area. There was a significant decrease in aggrecan and type II collagen (COL2A1) gene expressions by 73% (p = 0.029) and 65% (p = 0.029), respectively, in advanced OA area compared with the minimally OA area. From Western blotting and immunohistochemistry, SOX-5, SOX-6, SOX-9, type II collagen, and aggrecan protein expressions also significantly decreased in advanced OA cartilage compared with minimally OA cartilage. DNA methylation study of SOX-9 promoter regions revealed no difference in the epigenetic status between the two areas. It is concluded that SOX trio gene and protein decreased with advancement of OA in human articular cartilage.     

Anatomically Anchored Template-Based Level Set Segmentation: Application to Quadriceps Muscles in MR Images from the Osteoarthritis Initiative

In this paper, we present a semi-automated segmentation method for magnetic resonance images of the quadriceps muscles. Our method uses an anatomically anchored, template-based initialization of the level set-based segmentation approach. The method only requires the input of a single point from the user inside the rectus femoris. The templates are quantitatively selected from a set of images based on modes in the patient population, namely, sex and body type. For a given image to be segmented, a template is selected based on the smallest Kullback–Leibler divergence between the histograms of that image and the set of templates. The chosen template is then employed as an initialization for a level set segmentation, which captures individual anatomical variations in the image to be segmented. Images from 103 subjects were analyzed using the developed method. The algorithm was trained on a randomly selected subset of 50 subjects (25 men and 25 women) and tested on the remaining 53 subjects. The performance of the algorithm on the test set was compared against the ground truth using the Zijdenbos similarity index (ZSI). The average ZSI means and standard deviations against two different manual readers were as follows: rectus femoris, 0.78 ± 0.12; vastus intermedius, 0.79 ± 0.10; vastus lateralis, 0.82 ± 0.08; and vastus medialis, 0.69 ± 0.16.     

Mapping Stresses on the Tibial Plateau Cartilage in an Ovine Model Using In-Vivo Gait Kinematics

Annals of Biomedical Engineering - Understanding stresses within the knee joint is central to understanding knee function, and the etiology and progression of degenerative joint diseases such as...     

Estimation of Radiation Dose in CT Based on Projection Data

Managing and optimizing radiation dose has become a core problem for the CT community. As a fundamental step for dose optimization, accurate and computationally efficient dose estimates are crucial. The purpose of this study was to devise a computationally efficient projection-based dose metric. The absorbed energy and object mass were individually modeled using the projection data. The absorbed energy was estimated using the difference between intensity of the primary photon and the exit photon. The mass was estimated using the volume under the attenuation profile. The feasibility of the approach was evaluated across phantoms with a broad size range, various kVp settings, and two bowtie filters, using a simulation tool, the Computer Assisted Tomography SIMulator (CATSIM) software. The accuracy of projection-based dose estimation was validated against Monte Carlo (MC) simulations. The relationship between projection-based dose metric and MC dose estimate was evaluated using regression models. The projection-based dose metric showed a strong correlation with Monte Carlo dose estimates (R ²?>?0.94). The prediction errors for the projection-based dose metric were all below 15 %. This study demonstrated the feasibility of computationally efficient dose estimation requiring only the projection data.     

甘草苷对抑郁模型大鼠体重及行为学的影响

目的:观察甘草苷对慢性应激抑郁模型大鼠体重及行为学的影响。方法:72只成年SD雄性大鼠,随机分为6组:正常对照组、模型组、氟西汀组,以及甘草苷3个剂量组,每组12只。采用慢性应激加孤养造模,应激持续5周,从第3周起进行药物干预。观察大鼠体重及行为学改变。结果:应激5周后,与正常对照组相比模型组大鼠体重降低(429±45/494±37,P<0.01),糖水消耗量降低(8.3±3.3/14.4±2.7,P<0.01),强迫游泳的不动时间延长(96±10/37±9,P<0.01)。3周甘草苷灌胃后,大鼠体重仍低于正常对照组(444±45、442±22、423±28/494±37,P<0.01),但与模型组相比差异无显著性;甘草苷3个剂量组的糖水消耗量较模型组大鼠增加(11.4±4.0、14.1±3.5、14.0±2.5/8.3±3.3,P<0.05);强迫游泳不动时间较模型组大鼠也缩短(63±8、66±10、26±8、41±11/96±10,z=-2.02、-3.52、-3.03,P<0.05或P<0.01)。结论:除未发现对体重的影响外,3周灌胃甘草苷可以有效逆转抑郁模型大鼠上述的行为学改变,提示甘草苷具有抗抑郁样作用。     

The Protective Effect of Sodium Hyaluronate on the Cartilage of Rabbit Osteoarthritis by Inhibiting Peroxisome Proliferator-Activated Receptor-Gamma Messenger RNA Expression

Purpose

The purpose of this study was to study the protective effect and influence of sodium hyaluronate (Na-HA) on mRNA expression of peroxisome proliferators-activated receptor gamma (PPAR-γ) in cartilage of rabbit osteoarthritis (OA) model.

Materials and Methods

Forty eight white rabbits were randomly divided into A, B, and C groups. Group A was normal control group, B and C groups underwent unilateral anterior cruciate ligament transection (ACLT). The rabbits in group B were injected normal saline after ACLT; and Group C received intraarticular1% sodium hyaluronate (HA) injection 5 weeks after surgery, 0.3 mL once a week. At 11th week after surgery, all the rabbits were sacrificed. The cartilage changes on the medial femoral condyles were graded separately. Cartilage sections were stained with safranin-O and HE, and messenger RNA (mRNA) expression of PPAR-γ was detected by using real time polymerase chain reaction (Real Time-PCR).

Results

Cartilage degeneration in group B was significantly more severe than in A and C injection group. The grey value of Safranin-O of B group was higher than A and C groups. Expression of PPAR-γ mRNA in group B was higher than group A and C.

Conclusion

This study shows that Na-HA has a protective effect on articular cartilage degeneration, and the inhibitory effect on the PPAR-γ mRNA expression may be one of therapeutic mechanism of Na-HA.     

Posterodorsal Amygdaloid Lesions in Rats: Long-Term Effects on Body Weight

Bilateral lesions in the most posterodorsal aspects of the amygdala in female rats resulted in immediate and dramatic weight gains on a standard lab chow diet. The rate of weight gain returned to normal by Day 20, but the difference in body weight between animals with amygdaloid lesions and those with sham lesions was maintained for the duration of the study (60 days). Because rats with posterodorsal amygdaloid lesions have also been found to be hyperinsulinemic, it is hypothesized that the lesions result in a similar, though smaller, version of the syndrome that follows lesions of the ventromedial hypothalamus.     

Effect of Hedan Tablets on Body Weight and Insulin Resistance in Patients with Metabolic Syndrome

IntroductionApart from their recognized lipid-lowering effect, Hedan tablets, a mixture of Chinese herbal medicines, have demonstrated a certain weight-loss effect in clinical practice. The aim of this randomized, double-blind, placebo-controlled study was to verify the effect of Hedan tablets on body weight (BW) and insulin resistance (IR) in patients with metabolic syndrome (MetS).MethodsA total of 62 eligible patients with MetS were divided into two groups: the treatment group (Hedan tablets at 4.38 g/day tid) and the control group (placebo treatment). Both groups attended follow-ups at 8, 16, and 24 weeks during the process. The parameters of the assessment include lipid level, BW, triglyceride (TG) to high-density lipoprotein cholesterol (HDLc) ratio (TG/HDLc), homeostasis model assessment for IR (HOMA-IR) index, and adiponectin.ResultsPatients in the treatment group showed a significant decrease in BW compared to those in the control group (−4.47 vs. 0.06 kg) after 8 weeks of treatment. A significant decrease in body mass index (BMI) was also observed in the treatment group after 16 weeks of treatment (−1.79 vs. −0.03 kg/m²). In the treatment group, 20 out of 31 (64.5%) patients lost 5–10% BW and 4 out of 31 (12.9%) patients lost over 10% BW after 24 weeks of treatment. Although there were no significant changes in the patients'' HOMA-IR, the treatment group showed a significant reduction in TG/HDLc (−0.98 vs. −0.19) after 8 weeks of treatment and a significant increase in adiponectin (6.87 vs. −0.43) after 16 weeks of treatment.Discussion/ConclusionThe Hedan tablets significantly improve BW, BMI, TG/HDLc, and adiponectin in patients with MetS. Thus, Hedan tablets may be used as an adjunct to existing MetS management methods.     

Development of a BMI-Assigned Stunkard Scale for the Evaluation of Body Image Perception Based on Data of the SOS Reference Study

IntroductionStunkard''s figure rating scale is a widely used tool to assess weight status and, more recently, body image perception in people with obesity. However, large population-based studies on Europeans linking this scale''s silhouettes with measured BMI values are lacking. Therefore, we used measured weight and height data from the Swedish Obese Subjects (SOS) reference cohort to assign a mean BMI to each of the 9 Stunkard Scale silhouettes and to define silhouette cutoff values for categorizing people with obesity and overweight.MethodsA total of 1,128 participants from the SOS reference cohort were included (54% females, BMI = 25.2 [ranging from 17.6 to 45.4] ±3.8 kg/m², and age = 50 [ranging from 36 to 62] ±7 years [means ± standard deviation]). Patients estimated their own body size by choosing a silhouette of the Stunkard Scale. A mean BMI, based on measured weight and height, was assigned to each male and female silhouette of the Stunkard Scale. Measured BMI values were compared with BMI values calculated by simple linear regression analysis. ROC analysis was used to test accuracy of discrimination and the Youden index to assess optimal cutoff.ResultsFigure ratings and BMI were strongly correlated in men, r (518) = 0.76, p < 0.001 and women, r (606) = 0.80, p < 0.001. Silhouette selection significantly predicted BMI values in men, β = 16.03, t (518) = 25.30, p < 0.001, and women, β = 12.06, t (606) = 32.98, p < 0.001, and explained a significant proportion of variance in BMI values in men, R² = 0.55, F (1, 518) = 639.98, p < 0.001, and women, R² = 0.64, F (1, 606) = 1,087.88, p < 0.001. ROC curve analyses resulted in an optimal cutoff value of 6 for identifying people with obesity and 5 for overweight.ConclusionStunkard''s figure rating scale can be used with confidence to assess weight status. Silhouette selection accurately classifies subjects as overweight or obese.     

基于人工神经网络的足月胎儿体重预测方法

对胎儿体重的预测在产科临床上具有非常重要的意义,传统上采用回归分析方法预测胎儿体重,存在可靠性差等缺点。本研究采用反向传播(BP)人工神经网络方法预测胎儿体重,实验中采用双顶径、小脑横径、腹围、肝脏长度、股骨长度、股骨皮下脂肪厚度、孕龄等参数作为BP神经网络的输入参数,网络由输入层、隐含层和输出层三部分组成。对109例临床资料进行预测,结果为:训练组预测符合率达89.77%,平均绝对误差104.22g,平均相对误差3.24%;验证组预测符合率达76.19%,平均绝对误差190.84g,平均相对误差5.60%。表明人工神经网络预测胎儿体重方法十分有效,准确性高于回归方程。     

阿立哌唑与齐拉西酮对精神分裂症患者血糖、血脂和体重影响的Meta分析

目的评价阿立哌唑与齐拉西酮对精神分裂症患者血糖、血脂及体重影响的差异。方法计算机检索CBM、中国期刊全文数据库(CNKI)、万方数据库、维普中文科技期刊数据库(VIP),纳入关于阿立哌唑与齐拉西酮对精神分裂症患者血糖、血脂和体重的随机对照试验,由两名作者单独纳入与排除文献、评价质量、提取数据,将数据录入Rev Man 5.1进行Meta分析。结果共纳入6项符合标准的研究,合计样本量586例,其中阿立哌唑治疗组292例,齐拉西酮治疗组294例;Meta分析结果显示:干预结束时阿立哌唑组体质量低于齐拉西酮组[MD=-0.31,95%CI(-0.56,-0.05)],差异有统计学意义(P0.05);干预结束时阿立哌唑组HDL-c高于齐拉西酮组[MD=0.24,95%CI(0.01,0.47)],差异有统计学意义(P0.05);干预结束时两组的LDL-c,FBG,TCH,TG和BMI比较[MD=-0.31~0.19,95%CI(-0.47,0.43)],差异无统计学意义(P0.05)。结论阿立哌唑在改善血脂代谢、降低体重方面比齐拉西酮更占优势,但两者对于糖代谢的影响无差异。     

沙浴治疗兔膝骨关节炎的实验研究

目的：研究沙浴对兔膝关节骨性关节炎(osteoarthritis OA)关节周围血流、膝关节滑膜及软骨的病理改变的影响，为中老年人膝骨关节炎的沙浴治疗提供依据。方法：青紫兰兔15只，成功建立OA动物模型13只，其中12只随机分成自由活动组(A)，自由活动加沙疗组(B)，健侧关节沙疗对照组(C)。在平均气温32℃情况下，将模型兔下半部分掩埋在干燥的40～50℃的海沙中，1次25～30min，1次／d。观察沙疗后即时的膝关节周围血流情况，以及经过沙疗10d和20d后膝关节滑膜及软骨的病理改变。结果：沙疗后患侧膝关节活动改善，膝关节周围血管内血流明显增加，膝关节滑膜细胞层次逐渐减少、炎症细胞明显减少，但软骨细胞退变改善在光学显微镜下不明显。结论：沙疗能增加治疗部位的血流，改善局部血液循环，促进炎症的消退，对正常关节无不利影响。     

The Effect of Body Weight and Alcohol Consumption on Hyperuricemia and Their Population Attributable Fractions: A National Health Survey in China

IntroductionThe prevalence of hyperuricemia (HUA) is increasing worldwide; understanding of population attributable fraction of modifiable risk factors (MRFs) is important for disease prevention. Given the sparse evidence on how MRFs influence HUA in mainland China, we aimed to explore the effect of excess body weight and alcohol consumption and their population attributable fractions of HUA based on a national survey in mainland China.MethodsUsing data from the China National Health Survey which included 31,746 Han Chinese of 20–80 years of age from 10 provinces, we estimated the prevalence and MRFs (overweight/obesity and alcohol consumption) of HUA. HUA was defined as serum uric acid >417 μmol/L in men and >340 μmol/L in women. Restricted cubic-spline models were used to demonstrate the linear and nonlinear associations between exposures and HUA. The adjusted population attributable risk (PAR) was calculated to understand the relative importance of each MRF.ResultsThe prevalence of HUA was 25.1% in men and 15.9% in women. The population fraction of HUA cases that could be avoided by weight loss was 20.6% (19.3%–22.0%) in men and 18.1% (17.1%–19.0%) in women. The PAR of alcohol consumption was 12.8% (8.5%–17.1%) in men. Participants from Southwest China (Yunnan) had the highest HUA prevalence (47.9% in men and 29.9% in women) but with lower PAR of MRFs, especially in men (16.7%). Subjects in North China had lower HUA prevalence but higher PAR of MRFs. Around 44.8% male HUA cases in Inner Mongolia (26.9% of HUA prevalence) and 37.7% cases in Heilongjiang (34.4% of HUA prevalence) were attributable to overweight/obesity and alcohol consumption.ConclusionThere are significant sex and geographic difference on PAR of HUA due to MRFs. More tailored prevention strategies are needed to prevent HUA through weight loss and reduction of alcohol consumption.