Reliability and Measurement error of Active Knee extension Range of Motion in a Modified slump Test Position: A Pilot study

Abstract

The slump test is a tool to assess the mechanosensitivity of the neuromeningeal structures within the vertebral canal. While some studies have investigated the reliability of aspects of this test within the same day, few have assessed the reliability across days. Therefore, the purpose of this pilot study was to investigate reliability when measuring active knee extension range of motion (AROM) in a modified slump test position within trials on a single day and across days. Ten male and ten female asymptomatic subjects, ages 20–49 (mean age 30.1, SD 6.4) participated in the study. Knee extension AROM in a modified slump position with the cervical spine in a flexed position and then in an extended position was measured via three trials on two separate days. Across three trials, knee extension AROM increased significantly with a mean magnitude of 2° within days for both cervical spine positions (P>0.05). The findings showed that there was no statistically significant difference in knee extension AROM measurements across days (P>0.05). The intraclass correlation coefficients for the mean of the three trials across days were 0.96 (lower limit 95% CI: 0.90) with the cervical spine flexed and 0.93 (lower limit 95% CI: 0.83) with cervical extension. Measurement error was calculated by way of the typical error and 95% limits of agreement, and visually represented in Bland and Altman plots. The typical error for the cervical flexed and extended positions averaged across trials was 2.6° and 3.3°, respectively. The limits of agreement were narrow, and the Bland and Altman plots also showed minimal bias in the joint angles across days with a random distribution of errors across the range of measured angles. This study demonstrated that knee extension AROM could be reliably measured across days in subjects without pathology and that the measurement error was acceptable. Implications of variability over multiple trials are discussed. The modified set-up for the test using the Kincom dynamometer and elevated thigh position may be useful to clinical researchers in determining the mechanosensitivity of the nervous system.     

Hypophosphatasia: Enzyme Replacement Therapy Brings New Opportunities and New Challenges

Hypophosphatasia (HPP) is caused by loss‐of‐function mutation(s) of the gene that encodes the tissue‐nonspecific isoenzyme of alkaline phosphatase (TNSALP). Autosomal inheritance (dominant or recessive) from among more than 300 predominantly missense defects of TNSALP (ALPL) explains HPP's broad‐ranging severity, the greatest of all skeletal diseases. In health, TNSALP is linked to cell surfaces and richly expressed in the skeleton and developing teeth. In HPP,TNSALP substrates accumulate extracellularly, including inorganic pyrophosphate (PPi), an inhibitor of mineralization. The PPi excess can cause tooth loss, rickets or osteomalacia, calcific arthropathies, and perhaps muscle weakness. Severely affected infants may seize from insufficient hydrolysis of pyridoxal 5?‐phosphate (PLP), the major extracellular vitamin B₆. Now, significant successes are documented for newborns, infants, and children severely affected by HPP given asfotase alfa, a hydroxyapatite‐targeted recombinant TNSALP. Since fall 2015, this biologic is approved by regulatory agencies multinationally typically for pediatric‐onset HPP. Safe and effective treatment is now possible for this last rickets to have a medical therapy, but a number of challenges involving diagnosis, understanding prognosis, and providing this treatment are reviewed herein. © 2017 American Society for Bone and Mineral Research.     

Event-Specific Versus Unitary Causal Accounts of Optimism Bias

Optimism bias is often assumed to have a unitary cause regardless of the event, however, factors causing it may actually be event-specific. In Experiment 1 (N=23), subjects rated the importance of various causes for individual events. The results identified consistent differences in perceptions of causal factors across events. Experiment 2 (N=190) employed the possible causal factors absent exempt error and degree of motivation to investigate an event-specific theory of optimism bias in a manipulation design. Participants were encouraged to view one causal factor (absent/exempt or motivation) as either important or unimportant to future risk when they estimated their risk of absent/exempt-related, motivation-related and unrelated events (as determined in Experiment 1). A hanging control group received no manipulation. The event-specific theory's prediction that these manipulations would affect particular events and not others were not supported. However, discouraging the absent/exempt error reduced optimism bias across events, generally. Hence, a unitary and not an event-specific theory of optimism bias was supported. Furthermore, for the first time, the possible role of and confounding of cognitive manipulations of optimism bias by mood were evaluated, and not supported.     

Microsatellite Instability Is Absent in Liver and Biliary Mucosa of Patients with Primary Sclerosing Cholangitis

Microsatellite instability occurs in the colonicmucosa of patients with inflammatory bowel disease andmay predispose the mucosa to neoplastic transformation.It is unknown whether microsatellite instability also plays a role in the neoplastic riskassociated with primary sclerosing cholangitis. Weexamined 134 tissue samples from 21 patients withsclerosing cholangitis for microsatellite instability ateight loci. All tissues were also stainedimmunohistochemically using an antibody to theproliferation marker Ki-67. Microsatellite instabilitydid not occur in any samples from the intrahepatic orextrahepatic biliary system, although one patientdemonstrated instability in the colon. Ki-67 indicesranged from 0 to 2.5 in nondysplastic biliary epitheliumand from 1.5 to 29.4 in areas of dysplasia. The absence of microsatellite instability in sclerosingcholangitis suggests that the genetic basis ofneoplastic progression in chronic inflammatory diseaseof the bile ducts differs from that of intestinalcancers arising in the setting of chronic inflammatorybowel disease and may relate to differences in themicroenvironment in these two sites.     

Histologic Variation of Grade and Stage of Non-alcoholic Fatty Liver Disease in Liver Biopsies

Background: Sampling error regarding disease grade and stage has been ascribed to needle liver biopsies in patients with chronic liver disease. Although several studies evaluating sampling error in liver biopsies exist, none have investigated this phenomenon in patients with non-alcoholic fatty liver disease (NAFLD). This study aims to determine the rate and extent of sampling error in liver biopsies obtained from patients undergoing Roux-en-Y gastric bypass (RYGBP) surgery for morbid obesity. Methods: 10 morbidly obese patients underwent simultaneous liver biopsies from the right and left hepatic lobes during an open examination preceding the RYGBP procedure. The biopsies were subsequently randomly evaluated and then blindly re-evaluated by a liver pathologist. Degrees of inflammatory activity and fibrosis were determined and scored for each sample using a semi-quantitative system with 3 grades and 4 stages. Results: No grading differences were observed, and 3 patients (30%) had a difference of at least 1 stage between the right and left lobes. One patient had a 2-stage difference in paired samples, with significantly different biopsy sizes and number of portal tracts. Blinded histologic re-evaluation did not result in grading or staging scores that differed from the original evaluation. Conclusions: Liver biopsy samples taken from the right and left hepatic lobes showed similar grades of disease activity, but differed in histopathologic staging in 30% of the NAFLD patients. Obtaining an adequately sized biopsy (>1.0 cm in length with >10 portal tracts) greatly reduces sampling error.