Immune Complexes in Cystic Fibrosis

Circulating immune complexes were detected in serum and sputum of patients with cystic fibrosis (C.F.). There were extensive deposits of immunoglobulins and complement immune complexes in several of the C.F. organs, especially the respiratory and gastrointestinal tracts, but not in the kidneys. Significant concentrations of IgG and of complement complexes could be eluted from the lungs of the C.F. patients but not from those of controls. Studies involving immunoabsorption, autoradiography, and molecular sieving through Sephadex G-200 columns identified both bovine serum albumin and staphylococcal α-haemolysin as two of the antigens present in the immune complexes. The sedimentation constant of the immune complexes was about 8S to 11S. The clinical significance of these immune complexes and the wide variety of antibodies detected in C.F. patients are discussed.     

Objective classification of scapular kinematics in participants with movement faults of the scapula on clinical assessment

The aim of this study was to assess the potential of employing a classification tool to objectively classify participants with clinically assessed movement faults (MFs) of the scapula. Six participants with a history of shoulder pain with MFs of the scapula and 12 healthy participants with no movement faults (NMFs) performed a flexion movement control test of the scapula, while scapular kinematic data were collected. Principal component scores and discrete kinematic variables were used as input into a classifier. Five out of the six participants with a history of pain were successfully classified as having scapular MFs with an accuracy of 72%. Variables related to the upward rotation of the scapula had the most influence on the classification. The results of the study demonstrate the potential of adopting a multivariate approach in objective classification of participants with altered scapular kinematics in pathological groups.     

On the role of the starved codon and the takeoff site in ribosome bypassing in Escherichia coli

Translating ribosomes can skip over stretches of messenger RNA and resume protein chain elongation after a "bypassed" region. We have previously shown that limitation for isoleucyl-tRNA can initiate a ribosome bypass when an AUA codon is in the ribosomal A-site. We have now generalized this effect to other "hungry" codons calling for four different limiting aminoacyl-tRNA species, suggesting that a pause at any A-site will have this effect. We have assessed bypassing in a large family of reporters with nearly every different triplet in the "takeoff site", i.e. the P-site on the 5' side of the hungry codon, and an identical "landing site" codon 16 nucleotides downstream. The different takeoff sites vary over a factor of 50 in bypassing proficiency. At least part of this variation appears to reflect stability of the codon Colon, two colons anticodon interaction at the takeoff site, as indicated by the following: (a) the bypassing proficiency of different tRNAs shows a rough correlation with the frequency of A Colon, two colons U as opposed to G Colon, two colons C pairs in the codon Colon, two colons anticodon association; (b) specific tRNAs bypass more frequently from codons ending in U than from their synonym ending in C; (c) an arginine tRNA with Inosine in the wobble position which reads CGU, CGC, and CGA bypasses much more frequently from the last codon than the first two synonyms.     

Development of a statistical model of knee kinetics for applications in pre-clinical testing

Pre-clinical computational testing of total knee replacements (TKRs) often only considers a single patient model with simplified applied loads. In studies of multiple patients, most only take into account geometric differences, especially in studies on the knee. Limited availability of kinetic data means that it is difficult to account for inter-patient variability. Principal component analysis (PCA) based statistical models have been used to capture the variation of a set of data and generate new instances of the data. This study presents a method to create a statistical model of kinetic waveform data. A PCA based statistical model was created of the tibiofemoral joint loads for level gait of preoperative TKR patients using data predicted from a musculoskeletal model. A reconstruction test showed that, using principal components (PCs) representing 95% variance, the median root-mean-squared (RMS) error was <0.1 body weight (BW) for the forces and <0.001 BWm for the moments. Leave-one-out tests were also performed and although the median RMS error increased for each load in comparison to the reconstruction error (maximum was 0.2 BW for the axial force and 0.012 BWm for the varus-valgus moment) these were considered within an acceptable limit. The purpose of creating a statistical model is to be able to sample a large set of data representing a population from a small set of clinical data. Such models can potentially be used in population based studies of TKRs incorporating inter-patient variability.     

Rapid duplex immunoassay for wound biomarkers at the point-of-care

In this study we describe a novel method of sampling and quantifying wound biomarkers for clinical settings. We believe the chosen format will allow rapid assessments of wound healing and provide biomarker evidence-based decision points for treatment of the wound at the time of presentation. The wound monitoring principle uses a proprietary sample collection tool (a thermally reversible hydrogel) to sample and isolate biomarkers within a wound environment without further sample extraction/preparation steps. We show how gel samples can be analysed in a lateral flow assay format utilising fluorescent microspheres with optically discrete emission characteristics and demonstrate quantitative detection of two analytes (duplexing) achieved in a single test line. As a model assay, the chronic wound biomarkers interleukin 6 (IL6) and tumour necrosis factor alpha (TNFα) are used. Limits of detection of 48.5 pg/mL and 55.5 pg/mL respectively in hydrogel samples and 7.15 pg/mL and 10.7 pg/mL respectively in plasma are reported. We believe this is the first literature example of quantitative detection of multiple analytes within a single test line using spectral separation to distinguish the analytes.