The impact of different step rate threshold methods on physical activity intensity in older adults

BackgroundOlder adults benefit most from engaging in higher-intensity physical activity, which is often determined using step rate thresholds. Fixed step rate thresholds that correspond to moderate (MPA) and vigorous-intensity physical activity (VPA) have been developed for heuristic activity promotion. The activPAL monitor uses step rate thresholds to determine activity intensity. Stepping thresholds may also vary based on body mass index (BMI) or aerobic fitness level in older adults. Despite the various thresholds used in the literature, it is unclear whether they produce similar outcomes.Research QuestionHow does time spent in physical activity intensities compare between different step rate thresholds in older adults?MethodsThirty-eight participants (24♀; 67 ± 4 years; BMI: 26.6 ± 4.4 kg/m²) wore an activPAL monitor 24-hr/day for up to 7-d (total: 205-d). Aerobic fitness (V̇O₂max: 23 ± 8 ml/kg/min) was determined via indirect calorimetry during a maximal, graded cycling test. Time spent in each intensity category (light-physical-activity [LPA], MPA, VPA) was determined using the fixed (MPA/VPA) 100/130, 110/130, and activPAL step rate thresholds (74/212), as well as BMI-adjusted absolute (108.5 ± 2.5/134.0 ± 4.8) and BMI-adjusted relative (40%/60% V̇O₂max; 111.4 ± 14.7/132.0 ± 19.0) cut-offs. Times spent in each intensity category were compared between methods.ResultsThe activPAL and 100/130 thresholds yielded less LPA and more MPA than all other methods. The activPAL had no time spent in VPA at all. The BMI-adjusted absolute and relative thresholds produced statistically equivalent time in LPA and MPA (via equivalence testing), but not VPA. No two methods yielded similar time spent in LPA, MPA, or VPA.SignificanceThe choice of step rate threshold has a major impact on physical activity intensity outcomes in older adults. Inherently, strategies that adjust for older adults’ body size and/or aerobic fitness level provide a more individualized data processing strategy than fixed thresholds that assume the same threshold for all older adults     

Assessing the impact of blood alcohol concentration on the rate of in-hospital mortality following traumatic motor vehicle crash injury: A matched analysis of the National Trauma Data Bank

Background

The purpose of this study was to compare the outcomes of trauma patients who were injured in a motor vehicle crash and tested positive for alcohol upon hospital arrival versus those who tested negative.

LC-MS/MS法测定人血浆中布康唑浓度的不确定度评定

目的：评定LC-MS/MS法测定人血浆中布康唑浓度的不确定度。方法：分析测定过程中不确定度的来源，包括对照品的称量、仪器误差、标准溶液的配制、含药血浆样品的配制、血浆样品的处理、标准曲线的拟合、基质效应、重复性等，评定各来源分量的不确定度，计算合成不确定度和扩展不确定度。结果：人血浆中低（60.0 pg·mL^-1）、中（600.0 pg·mL^-1）、高（6 400.0 pg·mL^-1）浓度布康唑的扩展不确定度分别为5.62，63.90，626.26 pg·mL^-1（k=2，P=95%）。结论：LC-MS/MS法测定人血浆中布康唑浓度的不确定度主要由基质效应、血浆样品的处理（提取回收率），仪器误差、重复性（精密度）引入。     

UPLC-MS/MS测定73例患者血中头孢哌酮与舒巴坦的浓度

目的：建立液相色谱-串联质谱法（UPLC-MS/MS）同时测定人血浆中头孢哌酮与舒巴坦的浓度，分析头孢哌酮/舒巴坦血药浓度监测结果，为临床合理用药提供参考。方法：以氯唑沙宗为内标，采用Waters BEHC₁₈柱（2.1 mm×100 mm，1.7 μm）进行分离，通过串联质谱仪，负离子检测模式下，以多反应监测（MRM）方式进行定量测定。对某院2018年以不同给药方案进行治疗的73例住院患者测定的头孢哌酮/舒巴坦血药浓度结果进行分析。结果：头孢哌酮与舒巴坦在测定条件下1~200 mg·L^-1范围内线性关系良好，两者日内精密度RSD均<10%，基质效应分别为（72.77±0.99）%与（75.72±0.11）%，提取回收率均>90%。73例患者共监测血药浓度96次，其中不同给药方案2 g，q8 h（43例次）；2 g，q12 h（26例次）；2 g，q6 h（27例次），各组头孢哌酮血药浓度的中位数分别为34.12 mg·L^-1（4.12~177.79 mg·L^-1）、31.23 mg·L^-1（1.89~251.8 mg·L^-1）、59.96 mg·L^-1（1.77~140.58 mg·L^-1），舒巴坦血药浓度的中位数分别为6.3 mg·L^-1（0.61~136.01 mg·L^-1）、28.83 mg·L^-1（0.5~133.69 mg·L^-1）、11.17 mg·L^-1（0.73~143.53 mg·L^-1）。Mann-Whitney U检验显示，头孢哌酮血药浓度结果无统计学差异（P>0.05），舒巴坦有统计学差异（P<0.05）。结论：本检测方法操作简便、快速、重复性好，可满足临床头孢哌酮与舒巴坦浓度的检测；头孢哌酮/舒巴坦在不同给药方案下血药浓度结果与个体差异相关，有必要开展血药浓度监测并依据结果适时调整用药方案，提高治疗效果减少耐药率的发生。     

Understanding the Influence of Nanocarrier-Mediated Brain Delivery on Therapeutic Performance Through Pharmacokinetic-Pharmacodynamic Modeling

This study aimed at evaluating how encapsulation in a regular nanocarrier (NC) (providing extended circulation time) or in a brain-targeting NC (providing prolonged circulation time and increased brain uptake) may influence the therapeutic index compared with the unformulated drug and to explore the key parameters affecting therapeutic performance using a model-based approach. Pharmacokinetic (PK) models were built with chosen PK parameters. For a scenario where central effect depends on area under the unbound brain concentration curve and peripheral toxicity relates to peak unbound plasma concentration, dose-effect and drug-side effect curves were constructed, and the therapeutic index was evaluated. Regular NC improved the therapeutic index compared with the unformulated drug due to reduced peripheral toxicity, while brain-targeting NC enhanced the therapeutic index by lowering peripheral toxicity and increasing central effect. Decreasing drug release rate or systemic clearance of NC with drug still encapsulated could increase the therapeutic index. Also, a drug with shorter half-life would therapeutically benefit more from a NC encapsulation. This work provides insights into how a NC for brain delivery should be optimized to maximize the therapeutic performance and is helpful to predict if and to what extent a drug with certain PK properties would obtain therapeutic benefit from nanoencapsulation.     

Diagnostic sensitivity of electrophysiology and ultrasonography in ulnar neuropathies of different severity

ObjectiveTo assess the diagnostic performance of electrophysiology and nerve ultrasound in ulnar neuropathies of varying clinical severity in 135 consecutive patients.MethodsClinical severity of ulnar neuropathy was graded on a 4 point scale from very mild (symptoms only) to severe (marked atrophy of intrinsic hand muscles). Sensitivity and localization ability of electrophysiology and nerve ultrasound were assessed for each point of the scale.ResultsUltrasound had higher sensitivity than electrophysiology in clinically very mild (20% and 3% for ultrasound and electrophysiology, respectively) and mild (62% and 47% for ultrasound and electrophysiology, respectively) neuropathies, had greater localizing ability in axonal ulnar neuropathies, and identified nerve hypermobility.Ultrasound nerve cross-sectional area had strong positive correlation with both clinical and electrophysiological severity scores, but with significant overlap across the severity groups.ConclusionThe diagnostic work-up of ulnar neuropathies was improved by using both electrophysiology and ultrasound at all levels of clinical severity. Ultrasound increased the diagnostic yield in very mild and mild neuropathies, localized all the ulnar neuropathies with abnormal non-localizing electrophysiology and identified nerve hypermobility.SignificanceThis is the first detailed analysis of the diagnostic performance of electrophysiology and ultrasound in ulnar neuropathies of varying severity.     

重度苯妥英钠中毒的药学监护

目的首先确定中毒药物,然后通过测定血药浓度以了解中毒程度,为重度苯妥英钠中毒患者临床抢救治疗提供依据。方法间隔一定时间采集患者静脉血,萃取血中药物,在211 nm处以反相高效液相色谱法定性,明确中毒药物并测定血药浓度。结果在苯妥英中毒患者中最高血药浓度为68.94 mg.L-1,接近治疗浓度上限的3.5倍。结论患者为重度中毒,危及生命,需临床药师与临床医师积极配合,施行全程药学监护。     

Uptake of Adriamycin in tumour and surrounding brain tissue in patients with malignant gliomas

Summary Eight patients with malignant gliomas verified on CT scan, received an intravenous injection of 50 mg of Adriamycin R, 24 hours prior to surgical removal of the tumour. Peroperatively, both tumour and surrounding tissue specimens were obtained for determination of the tissue concentrations of Adriamycin and its reduced metabolite Adriamycinol. It was found that Adriamycin could be detected in tumour tissue from all patients. The concentration varied between 0,9 and 4,6 nmol/g tissue. In contrast, Adriamycin could only be detected in surrounding brain tissue from one patient.In anin vitro study a human malignant glioma cell line (U-251 MG) was exposed to various concentrations of Adriamycin for 24 hours. It was found that an intracellular drug concentration above 30 nmol/g cells caused a concentration dependent inhibition of cell growth. Thus, it is likely that the poor effect of Adriamycin on patients with malignant gliomas is due to an ineffective drug accumulation in the tumour tissue.