Subclinical albuminuria is linked to gray matter atrophy in type 2 diabetes mellitus

Objective

Microalbuminuria (MA), a marker of renal microvascular disease, is associated with brain atrophy and neurovascular changes in older adults with type 2 diabetes mellitus (DM). We evaluated the relationship between urine albumin-to-creatinine ratio (UACR) and regional brain volumes to determine whether subclinical albuminuria may indicate early structural brain changes in type 2 DM.

Materials/Methods

We studied UACR and brain volumes in 85 type 2 DM patients (64.8 ± 8.3 years) and 40 age-matched controls using 3D magnetization prepared rapid acquisition with gradient echo (MP-RAGE) MRI (magnetic resonance imaging) at 3 Tesla. The relationship between UACR and brain volumes was analyzed using the least square models.

Results

In DM patients, UACR ≥ 5 mg/g, UACR ≥ 10 mg/g and clinically significant MA (UACR ≥ 17 mg/g [males] and 25 mg/g [females]) were associated with lower gray matter (GM) volume in the frontal lobe (r²_adj = 0.2–0.4, P = 0.01–0.05) and UACR ≥ 5 mg/g was also related to global GM atrophy (r²_adj = 0.1, P = 0.04), independent of DM duration, glucose levels, HbA_1c and hypertension. For UACR ≥ 5 mg/g, a lower global GM volume was related to worse executive function (P = 0.04) in the DM group. No associations were found for UACR (< 5 mg/g) and controls.

Conclusions

Subclinical albuminuria (UACR ≥ 5 mg/g) is associated with lower GM volume that has clinical impact on cognitive function in older diabetic patients, and these relationships are independent of DM control and hypertension. Therefore, UACR levels may serve as an additional marker of DM-related brain structural changes.     

基于机器学习的新型冠状病毒(COVID-19)疫情分析及预测

本研究采用数学建模的方式,在有限的数据下,通过机器学习对近期爆发的新型冠状病毒(COVID-19)肺炎确诊人数趋势进行了预测,根据有关部门发布的信息,预测了疫情拐点出现的时间,并对比了各省预计最终确诊人数所占的比例,以此为依据,大致划分了疫情的严重程度,对各省市人民防护工作有指导意义。     

Clinician accuracy when subjectively interpreting articulating paper markings

Aims:

The aim of this study was to determine whether Subjective Interpretation of paper markings is a reliable method for identifying the relative occlusal force content of tooth contacts.

Methodology:

295 clinicians selected the “Most Forceful” and “Least Forceful” occlusal contacts in six occlusal-view photographs of articulating paper marks that were later compared against computerized occlusal analysis relative occlusal force measurements of the same tooth contacts. Means and standard deviations were calculated by years in clinical practice and by number of occlusion courses taken. A Chi-square analysis was also performed.

Results:

The mean correct for 295 participant dentists was 1·53 (±1·234). There were no significant differences found for years in practice (P>0·16) or number of occlusion courses taken (P>0·75). The Chi-square analysis showed a sensitivity of 12·6%, a specificity of 12·4%, a positive predictive value of 12·58%, and a negative predictive value of 12·42%. Chance was calculated at 12·5% correct.

Conclusions:

Subjective Interpretation is an ineffective clinical method for determining the relative occlusal force content of tooth contacts. The reported low scores obtained from a large group of participant dentists suggest clinicians are unable to reliably differentiate high and low occlusal force from looking at articulating paper marks. This longstanding method of visually observing articulating paper marks for occlusal contact force content should be replaced with a measurement-based, objective method.     

A role for the MAPK/ERK pathway in oligodendroglial differentiation in vitro: stage specific effects on cell branching

The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway is important for both long-term survival and timing of the progression of oligodendrocyte differentiation. Oligodendroglial cells treated with MEK inhibitor were distinguished by using stage specific markers: NG2 proteoglycan, A2B5, 2′3′nucleotide-cyclic 3′phosphodiesterase (CNPase) and myelin basic protein (MBP), and classified according to their morphology into different developmental stages. Treatment significantly increased the number of cells with more immature morphologies and decreased the number of mature cells. Furthermore, it increased the number of rounded cells that could not be classified into any of the oligodendroglial developmental stages. The strongest effects were usually observed shortly after treatment. Rounded cells were CNPase/MBP positive and they were not stained by anti-NG2 or A2B5, indicating that they were mature cells unable either to extend and/or to maintain their processes. These data showed an effect of the MAPK/ERK pathway on oligodendroglial branching, with possible consequences for the formation of the myelin sheath.     

Reduced multivariate polynomial-based neural network for automated traffic incident detection

This paper proposes a neural network model based on reduced multivariate polynomial pattern classifier for application in freeway incident detection. The reduced multivariate model (RM) is a recently proposed classifier model which is easy to implement and analyze, and has been observed to efficiently capture the nonlinear input–output relationships in many classification applications. Since the freeway incident detection can be treated as a two-category pattern classification problem, the reduced multivariate polynomial model is particularly suitable for this incident detection application. Both Recursive Singular Value Decomposition (RSVD)- based and gradient descent-based least square estimators were adopted to learn the RM classifier in this work. The comparison of results obtained with those from several other classification strategies demonstrates the efficacy of the proposed model for traffic incident detection.     

Comparison of BMD precision for Prodigy and Delphi spine and femur scans

Introduction Precision error in bone mineral density (BMD) measurement can be affected by patient positioning, variations in scan analysis, automation of software, and both short- and long-term fluctuations of the densitometry equipment. Minimization and characterization of these errors is essential for reliable assessment of BMD change over time.Methods We compared the short-term precision error of two dual-energy X-ray absorptiometry (DXA) devices: the Lunar Prodigy (GE Healthcare) and the Delphi (Hologic). Both are fan-beam DXA devices predominantly used to measure BMD of the spine and proximal femur. In this study, 87 women (mean age 61.6±8.9 years) were measured in duplicate, with repositioning, on both systems, at one of three clinical centers. The technologists were International Society for Clinical Densitometry (ISCD) certified and followed manufacturer-recommended procedures. All scans were acquired using 30-s scan modes. Precision error was calculated as the root-mean-square standard deviation (RMS-SD) and coefficient of variation (RMS-%CV) for the repeated measurements. Right and left femora were evaluated individually and as a combined dual femur precision. Precision error of Prodigy and Delphi measurements at each measurement region was compared using an F test to determine significance of any observed differences.Results While precision errors for both systems were low, Prodigy precision errors were significantly lower than Delphi at L1–L4 spine (1.0% vs 1.2%), total femur (0.9% vs 1.3%), femoral neck (1.5% vs 1.9%), and dual total femur (0.6% vs 0.9%). Dual femur modes decreased precision errors by approximately 25% compared with single femur results.Conclusions This study suggests that short-term BMD precision errors are skeletal-site and manufacturer specific. In clinical practice, precision should be considered when determining: (a) the minimum time interval between baseline and follow-up scans and (b) whether a statistically significant change in the patient’s BMD has occurred.     

非线性生物模型回归参数计算的一个新方法及应用

目的：研究变量代换对非线性生物模型回归参数的干扰，寻找消除或减少该干扰的新方法。方法：利用空间变换、泰勒(Taylor)级数和加权处理的组合方式消除或减少变量代换带来的严重影响。结果：给出一个计算非线性生物模型回归参数的新方法。结论：新方法消除或减少了变量代换带来的严重影响，保留了变量代换便于计算的优点；不但显著提高了非线性生物模型回归参数的精度，而且还能发现原始数据中隐藏的问题。     

最小二乘法求算药物动力学参数标准差的研究

本文提出利用血药浓度的平均值拟合血药浓度和时间的关系。应用最小二乘法把血药浓度的标准差分配给曲线参数,再由误差传递原理将曲线参数的标准差传给药物动力学参数,从而使药物动力学参数既能表现出药物在生物体内的一般规律,又能反映出生物体的个体差异。文中介绍了本方法的数学原理及头孢羟氨苄在狗体内的药物动力学计算实例。结果表明,本方法计算量小,结果可靠。