Reducing the Probability of False Positives in Malingering Detection of Social Security Disability Claimants

The Symptom Validity Scale (SVS) for low-functioning individuals (Chafetz, Abrahams, & Kohlmaier, 2007) employs embedded indicators within the Social Security Psychological Consultative Examination (PCE) to derive a score validated for malingering against two criterion tests: Test of Memory Malingering (TOMM) and Medical Symptom Validity Test (MSVT). When any symptom validity test is used with Social Security claimants there is a known rate of mislabeling (1-specificity), essentially calling a performance biased (invalid) when it is not, also known as a false-positive error. The great costs of mislabeling an honest claimant necessitated the present study, designed to show how multiple positive findings reduce the potential for mislabeling. This study utilized a known-groups design to address the impact of using multiple embedded indicators within the SVS on the diagnostic probability of malingering. Using four SVS components, Sequence, Ganser, and Coding errors, along with Reliable Digit Span (RDS), the positive predictive power was computed directly or by the chaining of likelihood ratios. The posterior probability of malingering increased from one to two to three failed indicators. With three failed indicators, there were essentially no false positive errors, and the total SVS score was in the range consistent with Definite Malingering, as shown in Chafetz et al. (2007). Thus, in a typical PCE when an examiner might have only a few embedded indicators, more confidence in a diagnosis of malingering might be obtained with a finding of multiple failures.     

Efficacy of strength training in prepubescent to early postpubescent males and females: Effects of gender and maturity

There has been considerable debate concerning the benefits of children participating in weight training programmes. With the potential benefits of such training in specific rehabilitation regimens, the safety/efficacy of weight training is a topic in need of scientific study. Fifty-two experimental and 39 control subjects participated in this study. A 2 × 2 × 2 (gender by treatment by Tanner stage) ANOVA was used to examine pre- to post-test differences in six strength measures, eight anthropometric measures, five motor performance measures, and one flexibility measure associated with participation in a 12-week progressive resistance programme. In addition, safety of the weight training programme was examined. For strength differences, there were two significant main effects favouring strength gains in males and four favouring the experimental group. For anthropometric changes, 3-way interactions occurred that were not easily explained. However, the predominant main effect was treatment; the experimental group generally experienced gains in body segment girths with decreases in skinfold thickness. For motor performance, the experimental group had greater improvements in three of five parameters. The experimental group also had significantly greater gains in flexibility. The weight training programme was associated with only one injury. These findings support the general observation that physical benefits can be gained safely by children who participate in a weight training programme.     

Association of birth factors with subsequent developmental disability: Effectiveness in predicting severity as measured by the PEDI

Objective: To determine if specific birth factors can be used to predict a subsequent disability and severity level in self-care, mobility and social function as measured by the Paediatric Evaluation of Disability Inventory (PEDI).

Design: This cross-sectional study design used retrospective data from birth records and concurrent data from PEDI scores.

Method: Sixty children (20 per group) were selected representing groups consistent with typical development, sensory processing disorders or physical disability. Mean age was 56 months; there were 32 males. Information extracted from birth records was compared to PEDI scores.

Results: Univariate ANOVA showed differences among groups for PEDI scores (p?<?0.001) and birth factors (p?<?0.001). A forward logistic regression analysis revealed gestational age and 5-minute Apgar scores as potential predictors of PEDI scores.

Conclusion: Findings indicated that two birth factors were related to later functional performance, but only in children with sensory processing deficits.     

Influence of polymer molecular weight in osteoinductive composites for bone tissue regeneration

In bone tissue regeneration, certain polymer and calcium-phosphate-based composites have been reported to enhance some biological surface phenomena, facilitating osteoinduction. Although the crucial role of inorganic fillers in heterotopic bone formation by such materials has been shown, no reports have been published on the potential effects the polymer phase may have. The present work starts from the assumption that the polymer molecular weight regulates the fluid uptake, which determines the hydrolysis rate and the occurrence of biological surface processes. Here, two composites were prepared by extruding two different molecular weight l/d,l-lactide copolymers with calcium phosphate apatite. The lower molecular weight copolymer allowed larger fluid uptake in the composite thereof, which was correlated with a higher capacity to adsorb proteins in vitro. Further, the large fluid absorption led to a quicker composite degradation that generated rougher surfaces and enhanced ion release. Following intramuscular implantation in sheep, only the composite with the lower molecular weight polymer could induce heterotopic bone formation. Besides influencing the biological potential of composites, the molecular weight also regulated their viscoelastic behaviour under cyclic stresses. The results lead to the conclusion that designing biomaterials with appropriate physico-chemical characteristics is crucial for bone tissue regeneration in mechanical load-bearing sites.     

Efficacy of physical activity interventions in post-natal populations: systematic review,meta-analysis and content coding of behaviour change techniques

This systematic review and meta-analysis reports the efficacy of post-natal physical activity change interventions with content coding of behaviour change techniques (BCTs). Electronic databases (MEDLINE, CINAHL and PsychINFO) were searched for interventions published from January 1980 to July 2013. Inclusion criteria were: (i) interventions including ≥1 BCT designed to change physical activity behaviour, (ii) studies reporting ≥1 physical activity outcome, (iii) interventions commencing later than four weeks after childbirth and (iv) studies including participants who had given birth within the last year. Controlled trials were included in the meta-analysis. Interventions were coded using the 40-item Coventry, Aberdeen & London - Refined (CALO-RE) taxonomy of BCTs and study quality assessment was conducted using Cochrane criteria. Twenty studies were included in the review (meta-analysis: n = 14). Seven were interventions conducted with healthy inactive post-natal women. Nine were post-natal weight management studies. Two studies included women with post-natal depression. Two studies focused on improving general well-being. Studies in healthy populations but not for weight management successfully changed physical activity. Interventions increased frequency but not volume of physical activity or walking behaviour. Efficacious interventions always included the BCTs ‘goal setting (behaviour)’ and ‘prompt self-monitoring of behaviour’.     

前蛋白转化酶枯草溶菌素9基因多态性的106进展

前蛋白转化酶枯草溶菌素9(PCSK9)是近年来新发现的一种与调节胆固醇代谢密切相关蛋白,属前蛋白转化酶家族。PCSK9可通过调节低密度脂蛋白胆固醇(LDLC)水平进而影响冠状动脉粥样硬化性心脏病、外周血管病、脑血管病、神经系统疾病及糖尿病等疾病的风险。近来研究表明,PCSK9基因多态性位点双向调节胆固醇水平。认识这些多态性位点,对于评估疾病严重性、预后或药物治疗反应有重要临床意义。本文就PCSK9基因多态性及其临床研究进展做一综述。     

丹参酮ⅡA对泡沫细胞胆固醇平衡的影响

目的通过体外细胞实验阐明丹参酮ⅡA对泡沫细胞胆固醇平衡的影响。方法体外培养小鼠RAW264.7细胞,以氧化型低密度脂蛋白诱导为泡沫细胞模型,并用不同浓度的丹参酮ⅡA进行处理,通过油红O染色观察细胞内脂质堆积情况,酶比色法定量检测细胞内总胆固醇和胆固醇酯的变化,荧光定量PCR和WesternBlot检测细胞中CD36、三磷酸腺苷结合盒转运体A1(ABCA1)、肝脏X受体α(LXRα)、过氧化体增殖物激活型受体α(PPARα)及PPARγ的mRNA和蛋白表达。结果 0～20 mg/L的丹参酮ⅡA对泡沫细胞增殖活力无明显影响,20 mg/L丹参酮ⅡA干预后,泡沫细胞内胆固醇酯与总胆固醇的比值显著降低,细胞内脂质累积减少,并上调AB-CA1、LXRα和PPARα的mRNA和蛋白表达,但对CD36表达无明显作用。结论丹参酮ⅡA能抑制泡沫细胞的形成,其机制可能是通过诱导PPARα、LXRα和ABCA1表达,促进胆固醇的外排。