Development and initial validation of a cost-effective,re-usable,ultrasound-compatible suprapubic catheter insertion training simulator

IntroductionSuprapubic catheterization (SPC) is a fundamental skill required of urology trainees. A lack of affordable simulation models and unpredictability of bedside SPCs limit experiential learning opportunities. Our objective was to develop and initially validate a re-usable, low-cost, ultrasound (US)-compatible SPC simulator for acquiring skills that transfer to the bedside.MethodsThe model was constructed using six components. Staff urologists and interventional radiologists (IRs) conducted a SPC and rated the model on three domains with multiple subcategories on a five-point Likert scale: anatomic realism; usefulness as a training tool; and global/overall reaction. Participants in our first-year urology “boot camp” received SPC training, practiced, and were evaluated via an objective structured clinical examination (OSCE). Staff ratings and OSCE scores determined the model’s initial face and content validity.ResultsTwelve staff physicians participated in the study. The mean scores for urologists and IRs, respectively, were: anatomical realism: 4.10 and 3.70; usefulness as a training tool: 4.23 and 4.24; and overall reaction: 4.40 and 4.44. Staff strongly agreed that the model should be incorporated into the residency curriculum. Over the past four years, 25 boot camp participants scored a mean of 99.7% (±1.8) on the OSCE, with high technical performance and entrustment scores (4.8 and 4.7, respectively). The model cost $55 CAD.ConclusionsThis novel, multiple-use, low-cost, easily reproducible US-compatible SPC simulator demonstrated initial face and content validity via high staff urologist and IR ratings and OSCE scores of first-year urology residents. Additional research is required for construct validation.     

Role of cell–matrix interactions on VIC phenotype and tissue deposition in 3D PEG hydrogels

Valvular interstitial cells (VICs) respond to 3D matrix interactions in a complex manner, but understanding these effects on VIC function better is important for applications ranging from valve tissue engineering to studying valve disease. Here, we encapsulated VICs in poly(ethylene glycol) (PEG) hydrogels modified with three different adhesive ligands, derived from fibronectin (RGDS), elastin (VGVAPG) and collagen‐1 (P15). By day 14, VICs became significantly more elongated in RGDS‐containing gels compared to VGVAPG or P15. This difference in cell morphology appeared to correlate with global matrix metalloproteinase (MMP) activity, as VICs encapsulated in RGDS‐functionalized hydrogels secreted higher levels of active MMP at day 2. VIC activation to a myofibroblast phenotype was also characterized by staining for α‐smooth muscle actin (αSMA) at day 14. The percentage of αSMA⁺ VICs in the VGVAPG gels was the highest (56%) compared to RGDS (33%) or P15 (38%) gels. Matrix deposition and composition were also characterized at days 14 and 42 and found to depend on the initial hydrogel composition. All gel formulations had similar levels of collagen, elastin and chondroitin sulphate deposited as the porcine aortic valve. However, the composition of collagen deposited by VICs in VGVAPG‐functionalized gels had a significantly higher collagen‐X:collagen‐1 ratio, which is associated with stenotic valves. Taken together, these data suggest that peptide‐functionalized PEG hydrogels are a useful system for culturing VICs three‐dimensionally and, with the ability to systematically alter biochemical and biophysical properties, this platform may prove useful in manipulating VIC function for valve regeneration. Copyright © 2013 John Wiley & Sons, Ltd.     

The BOLD hemodynamic response in healthy aging

Several previous studies have compared the blood oxygen level-dependent (BOLD) hemodynamic response (HDR) in healthy elderly subjects to the HDR in young subjects. Some studies have found a relative decreased amplitude in the elderly in the visual cortex, whereas other studies have found the elderly HDR amplitude in the visual cortex to be nearly identical to that in young subjects. A possible explanation for the different findings is that the peak voxel HDR is similar between the groups, but that the HDR in the group-averaged region-of-interest (ROI) is "washed out" by the inclusion of less significant voxels (due to a smaller extent of activation in the elderly) or by the inclusion of negative-peaking voxels. We tested this hypothesis using event-related functional magnetic resonance imaging (fMRI ). While undergoing fMRI, subjects performed a simple visual and motor task, pressing with their index fingers in response to visual presentation of the word tap. Data from 18 subjects, 8 young and 10 elderly, were analyzed. For each subject, a visual and a motor ROI was selected by choosing the most significant positive voxels within the anatomically defined ROI. This individual subject approach excluded both low-significance and negative-peaking voxels. Similar peaks were found for the elderly and the young subjects in both motor and visual regions and a more sustained BOLD response was found for the elderly in both regions. Additionally, as predicted, a greater percentage of voxels with a negative HDR was found for the elderly in the visual region; this finding was also replicated in our reanalysis of an independent fMRI and aging study from the fMRI Data Center. Functional neuroimaging observations of negative HDRs in visual areas have been interpreted as the effect of unconstrained processing during rest. Our results suggest that the elderly may have more unconstrained visual processing during the rest condition in the scanner. The observation that the group differences in the BOLD response are sensitive to voxel selection (e.g., inclusion of low-significance and/or negative voxels) underscores the importance of ROI selection criteria in the interpretation of fMRI studies using elderly populations.     

When is elevated testosterone not testosterone? When it is an immunoassay interfering antibody

A discrepancy between clinical findings and a markedly elevated testosterone (T) level stimulated search to explain this inconsistency. The cause of the falsely elevated T level was determined to be heterophile antibodies from a polyclonal gammopathy in a subject with acute myelogenous leukemia.     

Validation of the Clinical COPD Questionnaire as a psychophysical outcome measure in adult laryngotracheal stenosis

Objectives: To validate the Clinical Chronic Obstructive Pulmonary Disease Questionnaire (CCQ), a patient‐administered instrument developed for bronchopulmonary disease as a disease‐specific psychophysical outcome measure for adult laryngotracheal stenosis. Design: Prospective observational study. Settings: Tertiary/National referral airway reconstruction centre. Participants: Thirty‐three tracheostomy‐free patients undergoing endoscopic laryngotracheoplasty. Main outcome measures: CCQ and the Medical Research Council (MRC) Dyspnoea scale, a previously validated but more limited scale, were administered to patients 2 weeks before surgery, preoperatively, and 2 weeks after endoscopic laryngotracheoplasty. Pulmonary function was assessed preoperatively. Internal consistency was assessed with Cronbach α statistics and test–retest reliability was determined using intraclass correlation. Correlations between CCQ and MRC scale, and pulmonary function were used to assess convergent and divergent validity respectively. Instrument responsiveness was assessed by correlating total and domain‐specific CCQ scores with anatomical disease severity and post‐treatment effect size. Results: There were 12 males and 21 females. Mean age was 44 ± 15 years. Cronbach α coefficient and intraclass correlation coefficient were 0.88 and 0.95 respectively. Total and domain‐specific CCQ scores significantly correlated with the MRC scores (P < 0.001) and significant correlations between CCQ and peak expiratory flow rate and FEV₁ were identified (P < 0.03). There were statistically significant changes in total and domain‐specific CCQ scores when different stenosis severities were compared. Clinical COPD Questionnaire scores also changed significantly and congruently following surgery (P < 0.05 in both cases). Discussion: Clinical COPD Questionnaire is a valid and sensitive instrument for assessing symptom severity and levels of function and well‐being in adult patients with laryngotracheal stenosis and can be used as a patient‐centred disease‐specific outcome measure for this condition.     

Laboratory evaluation of aspirin responsiveness

Aspirin is the most commonly used antiplatelet medication. Laboratory monitoring of aspirin response has recently become a topic of interest due to potential impacts on patient management and clinical outcomes. This article summarizes available laboratory testing of aspirin response with focus on technical issues, limitations, and current opinion on the utility of routine patient testing. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.