Reliability of a new loaded rolling wheel system for measuring spinal stiffness in asymptomatic participants

Abstract Background Few, if any, patient reported symptoms have been shown to be related to objective measures of spine function. Recently, patient-reported measures of disability following spinal manipulative therapy have been associated with an immediate decrease in spinal stiffness obtained by instrumented L3 indentation. Given this novel relation, we anticipate that stiffness measures obtained from locations in addition to L3 may yield valuable information. As such, our research team has developed a new technique to acquire stiffness data continuously over an entire spinal region. The reliability of stiffness measurements obtained by this new technique has yet to be quantified. Methods Continuous stiffness testing employs a weighted roller that moves uninterrupted over the spine while measuring the resulting spinal deflection along a subject-specific, laser-defined trajectory. A volunteer sample of asymptomatic participants were assessed in 2 sessions occurring 1 to 4 days apart, with each session scheduled at the same time of day. Each session consisted of 3 trials each beginning at a baseline of ~ 17 N then progressing to a maximally tolerable load as defined from pre-test familiarization trials (~ 61, 72 or 83 N). Reliability was evaluated with the intraclass correlation coefficient, the standard error of measurement and Bland & Altman analysis. Results A total of 17 asymptomatic participants (mean age 29.2 +/− 6 years, 53% female) took part in the study. Overall, the within and between-session reliability of lumbar spine stiffness measures at the maximal tolerable load was excellent ranging from 0.95–1.00 and good to excellent ranging from 0.82–0.93, respectively. Trial averaging was found to reduce standard error of measurement by a mean of 35.2% over all measurement conditions compared to a single trial. Bland and Altman plots for agreement in lumbar spine stiffness measurements varied from − 0.3 +/− 1.2 at unloaded condition to − 0.2 +/− 1.2 at loaded condition. Data from two participants were removed due to the development of back pain between two sessions. Conclusion This study introduced a new technique for measuring spinal stiffness over an entire spinal region in asymptomatic human participants. The new technique produced reliable measurements quantifying the load-displacement values for within-session and between-session assessments

In vitro and in silico studies of novel synthetic ACE-inhibitory peptides derived from Saccharomyces cerevisiae protein hydrolysate

The structure-function relation of YR-10 (YGKPVAVPAR) was investigated by synthesizing four structural analogs of that including YHR-10 (YGKHVAVHAR), GA-8 (GKPVAVPA), GHA-8 (GKHVAVHA), and PAR-3 (PAR). GA-8 (GKPVAVPA) was synthesized on the basis of simulated enzymatic gastrointestinal digestion performed by bioinformatics tools (expasy-peptide cutter). This study explains the molecular mechanisms for the interaction of synthetic peptides with ACE. The IC50 values of each were 139.554 +/- 2.3, 61.91 +/- 1.2, 463.230 +/- 3.56, 135.135 +/- 2.1, 514.024 +/- 5.86 mu M, respectively. Results indicated that Pro replacement with His in YR-10 and GA-8 increased ACE inhibitory activity respectively, by 55.63% and 70.82%. Removal of Tyr and Arg from respectively N and C terminal positions of YR-10, following in silico simulated gastrointestinal digestion caused the 3.31 fold decrease in ACE inhibitory activity. YHR-10 showed the best docking poses, and GHA-8 exhibited interaction with Zn2+. Lineweaver-Burk plots of most active peptides suggest that they act as noncompetitive inhibitors against ACE

Predicting who responds to spinal manipulative therapy using a short-time frame methodology: Results from a 238-participant study.

BackgroundSpinal manipulative therapy (SMT) is among the nonpharmacologic interventions that has been recommended in clinical guidelines for patients with low back pain, however, some patients appear to benefit substantially more from SMT than others. Several investigations have examined potential factors to modify patients' responses prior to SMT application. The objective of this study was to determine if the baseline prediction of SMT responders can be improved through the use of a restricted, non-pragmatic methodology, established variables of responder status, and newly developed physical measures observed to change with SMT.Materials and methodsWe conducted a secondary analysis of a prior study that provided two applications of standardized SMT over a period of 1 week. After initial exploratory analysis, principal component analysis and optimal scaling analysis were used to reduce multicollinearity among predictors. A multiple logistic regression model was built using a forward Wald procedure to explore those baseline variables that could predict response status at 1-week reassessment.ResultsTwo hundred and thirty-eight participants completed the 1-week reassessment (age 40.0± 11.8 years; 59.7% female). Response to treatment was predicted by a model containing the following 8 variables: height, gender, neck or upper back pain, pain frequency in the past 6 months, the STarT Back Tool, patients' expectations about medication and strengthening exercises, and extension status. Our model had a sensitivity of 72.2% (95% CI, 58.1-83.1), specificity of 84.2% (95% CI, 78.0-89.0), a positive likelihood ratio of 4.6 (CI, 3.2-6.7), a negative likelihood ratio of 0.3 (CI, 0.2-0.5), and area under ROC curve, 0.79.ConclusionIt is possible to predict response to treatment before application of SMT in low back pain patients. Our model may benefit both patients and clinicians by reducing the time needed to re-evaluate an initial trial of care

Improving biomass and carbohydrate production of microalgae in the rotating cultivation system on natural carriers

Abstract Biofilm-based algal technologies have gained popularity due to higher biomass productivity, efficient harvesting, and water-saving over suspended growth systems. A rotating attached system was designed to assess the biofilm-forming capacity of different isolated microalgal strains from the Persian Gulf. Four microalgal strains, including two Chlorella sp., one Picochlorum sp. and one filamentous cyanobacterium Desmonostoc sp. were cultivated on four carriers: jute, cotton, yarn and nylon. The carriers’ physicochemical surface characteristics and attachment effects, like contact angle, were investigated. The incorporated biomass and exopolysaccharides (EPS) content in the suspended and biofilm system was calculated and compared. The results showed that the cyanobacterium strain had the biofilm formation capability on both jute and cotton in the attached cultivation system. Under the same culture conditions, the biomass productivity on jute and cotton carriers was significantly higher (4.76 and 3.61 g m− 2 respectively) than the growth in aqueous suspension (1.19 g m− 2 d− 1). The greatest incorporated exopolysaccharides amount was observed on jute (43.62 ± 4.47%) and the lowest amount was obtained from the growth on positive charge yarn (18.62 ± 1.88%). This study showed that in comparison with planktonic growth, the colonization of cyanobacterial cells and subsequent production of extracellular matrix and biofilm formation can lead to increased biomass production

Synthesis, in vitro and cellular antioxidant activity evaluation of novel peptides derived from Saccharomyces cerevisiae protein hydrolysate : structure-function relationship

The relationship between structure and function of primary antioxidant peptide, YR-10 (YGKPVAVPAR) was considered by synthesizing three analogues including YHR-10 (YGKHVAVHAR), GA-8 (GKPVAVPA) and PAR-3 (PAR). Antioxidant activity was determined through in vitro and cellular assays. Substitution of Pro with His in the structure of YR-10 led to significant (P < 0.05) higher ABTS radical scavenging and ferric reducing activity. Following in silico simulated gastrointestinal digestion, Tyr and Arg were omitted, respectively, from N and C-terminal positions and resulted in decreasing DPPH, ABTS radical scavenging, and ferric reducing activities. PAR-3 showed the best inhibitory activity on linoleic acid oxidation. Pretreatment of Caco-2 cells with YR-10, YHR-10, and GA-8 (1000 mu M) before exposure to H2O2 (160 mu M) resulted in 34.10%, 39.66% and 29.159% reduction in malondialdehyde and 53.52%, 17.02% and 24.71% reduction in protein carbonyl levels. The peptide pretreatment reduced catalase level in cells and PAR-3 exhibited the most protective effects on the viability of cells exposed to oxidative stress