Diagnostic performance of sonographic activity scores for adult terminal ileal Crohn's disease compared to magnetic resonance and histological reference standards: experience from the METRIC trial.

OBJECTIVES: The simple ultrasound activity score for Crohn's disease (SUS-CD) and bowel ultrasound score (BUSS) are promising intestinal ultrasound (IUS) indices of CD, but studied mainly in small settings with few sonographers. We compared SUS-CD and BUSS against histological and magnetic resonance enterography (MRE) reference standards in a post hoc analysis of a prospective multicentre, multireader trial. METHODS: Participants recruited to the METRIC trial (ISRCTN03982913) were studied, including those with available terminal ileal (TI) biopsies. Sensitivity and specificity of SUS-CD and BUSS for TI CD activity were calculated with 95% confidence intervals (CI), from the prospective observations of the original METRIC trial sonographers against the histological activity index (HAI) and the simplified magnetic resonance index of activity (sMARIA). RESULTS: We included 284 patients (median 31.5 years, IQR 23-46) from 8 centres, who underwent IUS and MRE. Of these, 111 patients had available terminal ileal biopsies with HAI scoring. Against histology, sensitivity and specificity for active disease were 79% (95% CI 69-86%) and 50% (31-69%) for SUS-CD, and 66% (56-75%) and 68% (47-84%) for BUSS, respectively. Compared to sMARIA, the sensitivity and specificity for active CD were 81% (74-86%) and 75% (66-83%) for SUS-CD, and 68% (61-74%) and 85% (76-91%) for BUSS, respectively. The sensitivity of SUS-CD was significantly greater than that of BUSS against HAI and sMARIA (p < 0.001), but its specificity was significantly lower than of BUSS against the MRE reference standard (p = 0.003). CONCLUSIONS: Particularly when compared to MRE activity scoring, SUS-CD and BUSS are promising tools in a real-world clinical setting. CLINICAL RELEVANCE STATEMENT: When tested using data from a multicentre, multireader diagnostic accuracy trial, the simple ultrasound activity score for Crohn's disease (SUS-CD) and bowel ultrasound score (BUSS) were clinically viable intestinal ultrasound indices that were reasonably sensitive and specific for terminal ileal Crohn's disease, especially when compared to a magnetic resonance reference standard. KEY POINTS: The simple ultrasound activity score for Crohn's disease and bowel ultrasound score are promising intestinal ultrasound indices of Crohn's disease but to date studied mainly in small settings with few sonographers. Compared to histology and the magnetic resonance reference standard in a multicentre, multireader setting, the sensitivity of simple ultrasound activity score for Crohn's disease is significantly greater than that of bowel ultrasound score. The specificity of simple ultrasound activity score for Crohn's disease was significantly lower than that of bowel ultrasound score compared to the magnetic resonance enterography reference standard. The specificity of both indices was numerically higher when the magnetic resonance enterography reference standard was adopted.

Developing patient-centred MRI safety culture: a quality improvement report.

OBJECTIVE: Despite having a detailed MRI-safety questionnaire check at the point of referral, we have encountered a significant number of near-misses with patients being identified with MRI-Unsafe devices at the time of appointments, making this an important safety hazard. METHODS AND MATERIALS: A two-part survey was performed to assess referrer compliance of asking MRI-questionnaires. 120 outpatients across 3 MRI sites were interviewed at the time of appointment to confirm whether their referrers completed the MRI questionnaires with them at the time of referral.Location:Department of Radiology, Ninewells Hospital, Perth Royal Infirmary and Stracathro Hospital in Scotland. RESULTS: Only 50-55 % of patients confirmed that they were asked about presence of a pacemaker at the point of referral. Less than 50 % of patients reported being asked about other potential hazards.Suggested strategies for change: (1) Risk Alert-Sent to all MRI referrers in the organization. ( 2) Changes to MRI Safety Questionnaire. (3) Feedback mechanism to referrers-NHS trust website publications on number of recorded near-misses and wasted appointments due to MRI-safety issues. (4) Compulsory education/training of future referrers (junior doctors/allied health professionals). (5) Education of patients/public on MRI safety-Displaying patient information leaflets/posters in waiting areas of the hospital.Key measures for improvement: (1) Reduction in number of recorded near-misses. (2) System improvements, referrer and patient education, reduction of wasted MRI appointments and improvement of waiting-times for MRI appointments Effects of survey and conclusions: The survey highlights the possibility of inadequate referrer attention, and poor patient communication about MRI safety questionnaire with regards to potential hazards of MRI examination in presence of undeclared implants. It initiated several interventions resulting in improved patient safety, with no events in next 12 months, whilst promoting public and referrer's understanding of potential MRI safety issues. Such actions are recommended for all NHS centres across UK since there are significant similarities in functioning across UK.

Evaluation of a new system for developing particulate enzymes based on the surface (S)-layer protein (RsaA) of Caulobacter crescentus: fusion with the beta-1,4-glycanase (Cex) from the cellulolytic bacterium Cellulomonas fimi yields a robust, catalytically active product.

Immobilized biocatalysts, including particulate enzymes, represent an attractive tool for research and industrial applications because they combine the specificity of native enzymes with the advantage that they can be readily separated from end product and reused. We demonstrated the use of the Caulobacter crescentus surface (S)-layer protein (RsaA) secretion apparatus for the generation of particulate enzymes. Specifically, a candidate protein made previously by fusion of the beta-1,4-glycanase (Cex) from the cellulolytic bacterium Cellulomonas fimi with the C-terminus of RsaA was evaluated. Cex/RsaA cleaved the glycosidic linkage in the artificial substrate p-nitrophenyl-beta-D-cellobioside with a KM similar to that of native Cex (1.1 mM for Cex/RsaA vs 0.60 mM for Cex), indicating that the particulate Cex enzyme was able to bind substrate with wild-type affinity. By contrast, the kcat value was significantly reduced (0.08 s-1 for Cex/RsaA vs 15.8 s-1 for Cex), likely owing to the fact that the RsaA C-terminus induces spontaneous unstructured aggregation of the recombinant protein. Here, we demonstrated that not only can an RsaA fusion protein be cheaply produced and purified to a high yield (76 mg/L of dry wt for Cex/RsaA), but it can also be efficiently recycled. The Caulobacter S-layer secretion system therefore offers an attractive new model system for the production of particulate biocatalysts.

S-layer-mediated display of the immunoglobulin G-binding domain of streptococcal protein G on the surface of Caulobacter crescentus: development of an immunoactive reagent.

The immunoglobulin G (IgG)-binding streptococcal protein G is often used for immunoprecipitation or immunoadsorption-based assays, as it exhibits binding to a broader spectrum of host species IgG and IgG subclasses than the alternative, Staphylococcus aureus protein A. Caulobacter crescentus produces a hexagonally arranged paracrystalline protein surface layer (S-layer) composed of a single secreted protein, RsaA, that is notably tolerant of heterologous peptide insertions while maintaining the surface-attached crystalline character. Here, a protein G IgG-binding domain, GB1, was expressed as an insertion into full-length RsaA on the cell surface to produce densely packed immunoreactive particles. GB1 insertions at five separate sites were expressed, and all bound rabbit and goat IgG, but expression levels were reduced compared to those of wild-type RsaA and poor binding to mouse IgG was noted. To remedy this, we used the 20-amino-acid Muc1 peptide derived from human mucins as a spacer, since insertions of multiple tandem repeats were well tolerated for RsaA secretion and assembly. This strategy worked remarkably well, and recombinant RsaA proteins, containing up to three GB1 domains, surrounded by Muc1 peptides, not only were secreted and assembled but did so at wild-type levels. The ability to bind IgG (including mouse IgG) increased as GB1 units were added, and those with three GB1 domains bound twice as much rabbit IgG per cell as S. aureus cells (Pansorbin). The ability of recombinant protein G-Caulobacter cells to function as immunoactive reagents was assessed in an immunoprecipitation assay using a FLAG-tagged protein and anti-FLAG mouse monoclonal antibody; their performance was comparable to that of protein G-Sepharose beads. This work demonstrates the potential for using cells expressing recombinant RsaA/GB1 in immunoassays, especially considering that protein G-Caulobacter cells are more cost-effective than protein G beads and exhibit a broader species and IgG isotype binding range than protein A.

Tai Chi versus brisk walking in elderly women.

PURPOSE: to compare the effects of a short style of Tai Chi versus brisk walking training programme on aerobic capacity, heart rate variability (HRV), strength, flexibility, balance, psychological status and quality of life in elderly women. METHODS: nineteen community-dwelling, sedentary women (aged 71.4 +/- 4.5 years) were randomly assigned to Tai Chi Chuan (TCC; n = 11) or brisk walking group (BWG; n = 8). A separate group of elderly women was recruited from the same population to act as a sedentary comparison group (SCG; n = 8). The exercise groups met for 1 h, three days per week for 12 weeks. Outcomes measured before and after training included estimated VO2max, spectral analysis of HRV (high-frequency, low-frequency power as well as high- and low-frequency power in normalised units) as a measure of autonomic control of the heart, isometric knee extension and handgrip muscle strength, single-leg stance time, the State Trait Anxiety Inventory (STAI), Profile of Mood States (POMS) and Short Form-36 (SF-36) questionnaires. RESULTS: significant improvement was seen in estimated VO(2)max in the TCC group (TCC versus SCG P = 0.003, TCC versus BWG P = 0.08). The mean within-person change of high-frequency power in normalised units (HFnu) increased [8.2 (0.14-16.3)], representing increased parasympathetic activity, and low-frequency power in normalised units (LFnu) decreased [-8.7 (-16.8-0.5)], representing decreased sympathetic activity, in the TCC group only. Significant gains were also seen in the non-dominant knee extensor strength and single-leg stance time (TCC versus BWG P < 0.05). CONCLUSIONS: a short style of TCC was found to be an effective way to improve many fitness measures in elderly women over a 3-month period. TCC was also found to be significantly better than brisk walking in enhancing certain measures of fitness including lower extremity strength, balance and flexibility.

Two determinants in the capsid of a persistent type 3 poliovirus exert different effects on mutant virus uncoating.

Mutant polioviruses (PV) have been previously found to be capable of establishing persistent infections in HEp-2c cells. Together, two amino acid substitutions in the viral capsid of a type 3 poliovirus (PV-3), at positions VP213 and VP1(290), are sufficient to confer the persistent phenotype to a normally lytic virus. When susceptible cells are infected, the double mutant T7L+2L(13)1N(290) undergoes unique conformational changes in the capsid, modifying its sedimentation coefficient from 160S to 147S. In the present study, we have further investigated mutant PV decapsidation and, in particular, the effect of each determinant independently. Our results indicate that the novel 147S form was also generated by a mutant carrying only the determinant 1N290. This form was not produced as a result of inherent capsid instability and it was generated only upon specific PV-host cell interactions. The second viral determinant, 2L13, also modified receptor-induced conformational changes, although differently from 1N290.