Denuded Descemet's membrane supports human embryonic stem cell-derived retinal pigment epithelial cell culture.

Recent clinical studies suggest that retinal pigment epithelial (RPE) cell replacement therapy may preserve vision in retinal degenerative diseases. Scaffold-based methods are being tested in ongoing clinical trials for delivering pluripotent-derived RPE cells to the back of the eye. The aim of this study was to investigate human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cells survival and behaviour on a decellularized Descemet's Membrane (DM), which may be of clinical relevance in retinal transplantation. DMs were isolated from human donor corneas and treated with thermolysin. The DM surface topology and the efficiency of the denudation method were evaluated by atomic force microscope, scanning electron microscopy and histology. hESC-RPE cells were seeded onto the endothelial-side surface of decellularized DM in order to determine the potential of the membrane to support hESC-RPE cell culture, alongside maintaining their viability. Integrity of the hESC-RPE monolayer was assessed by measuring transepithelial resistance. RPE-specific gene expression and growth factors secretion were assessed to confirm maturation and functionality of the cells over the new substrate. Thermolysin treatment did not affect the integrity of the tissue, thus ensuring a reliable method to standardize the preparation of decellularized DM. 24 hours post-seeding, hESC-RPE cell attachment and initial proliferation rate over the denuded DM were higher than hESC-RPE cells cultured on tissue culture inserts. On the new matrix, hESC-RPE cells succeeded in forming an intact monolayer with mature tight junctions. The resulting cell culture showed characteristic RPE cell morphology and proper protein localization. Gene expression analysis and VEGF secretion demonstrate DM provides supportive scaffolding and inductive properties to enhance hESC-RPE cells maturation. Decellularized DM was shown to be capable of sustaining hESC-RPE cells culture, thus confirming to be potentially a suitable candidate for retinal cell therapy.

Metabolic activity of the left and right atria are differentially altered in patients with atrial fibrillation and LV dysfunction.

BACKGROUND: Alterations in atrial metabolism may play a role in the perpetuation of atrial fibrillation (AF). This study sought to compare 18F-fluorodeoxyglucose (FDG) uptake on PET, in patients with LV dysfunction versus those without AF. METHODS: Seventy-two patients who underwent myocardial viability assessment were evaluated. AF patients (36) had persistent or permanent AF based on history and ECG. Patients without AF (36) were matched to AF patients based on sex, diabetes, age, and LVEF. Maximum and mean FDG Standard Uptake Values (SUV) in the left atrial (LA) wall and right atrial (RA) wall were measured. Tissue-to-blood ratios (TBR) were calculated as atrial wall to blood-pool activity. Atrial volumes were measured by echocardiography. RESULTS: Maximum and mean FDG SUV and TBRs were significantly increased in the RA (but not the LA) of patients with AF compared to those without (P < 0.01). When accounting for changes in atrial volume, the presence of AF remained a significant predictor of higher RAMAX, but not RAMEAN FDG uptake. CONCLUSION: In patients with LV dysfunction from ischemic cardiomyopathy, LA and RA glucose metabolism are differentially altered in those with persistent atrial fibrillation. Further investigations should elucidate the temporal relationship between AF and glucose metabolic changes, as a potential target for therapy.

Low diagnostic sensitivity of cystoscopy and cystography of surgically confirmed vesicoenteric fistulae.

PURPOSE: The objective of this study was to assess the accuracy of cystoscopy and cystography, as compared to other diagnostic studies, in identifying vesicoenteric fistulae (VEF) in a contemporary series of patients with surgically confirmed VEF. METHODS: With institutional review board approval, we performed a single-center retrospective review of surgically confirmed VEF between 2002 and 2018. Demographic data, comorbidities, symptoms, and diagnostic evaluation were reviewed. The sensitivity, specificity, and accuracy of cystoscopy in diagnosis of VEF were compared to cross-sectional imaging. RESULTS: The study cohort consisted of 51 patients with surgically confirmed VEF secondary to diverticular disease. Diagnostic evaluation included cross-sectional imaging with CT (94%), colonoscopy (82%), cystoscopy (75%), cystography (53%), and barium enema (26%). Cystoscopic evaluation definitively demonstrated evidence of VEF in 34% of patients, while 55% of patients had nonspecific urothelial changes on cystoscopy without definitively demonstrating VEF. Comparatively, the sensitivity of VEF was 25% for cystography and 84% for CT. CONCLUSIONS: In clinical practice, the diagnostic work-up of VEF is variable. In the modern era of managed care, inclusion of cystoscopy and cystography in the evaluation of VEF does not contribute a substantial additive benefit over standard cross-sectional imaging. Cystoscopy and cystography could potentially be eliminated from the diagnostic evaluation of VEF, in the absence of a concern for malignancy, in an effort to minimize unnecessary invasive testing as well as health care expenditures.

Stem Cell-Derived Retinal Pigment Epithelial Layer Model from Adult Human Globes Donated for Corneal Transplants.

An adult human retinal pigment epithelial layer (ahRPE) model derived from stem cells isolated from native RPE monolayers (ahRPE-SCs) exhibits key physiological characteristics of native tissue and therefore provides the means to create a human "disease in a dish" model to study RPE diseases. Traditionally, RPE lines are established from whole globes dedicated to research. Here we describe a new technique for establishing primary RPE lines from the posterior poles of globes used for corneal transplants. Since tissues from corneal transplants are derived from younger and healthier donors than those used for research, we have hypothesized that RPE cells isolated from corneal transplantation globes will result in improved primary RPE line establishment. Our new procedure increases the rate of establishing successful RPE cultures and improves the total cell number yield. Use of this advanced methodology can provide a new source of high-quality primary RPE line cultures. © 2018 by John Wiley & Sons, Inc.

Dimensional Changes of Tracheids during Drying of Radiata Pine (Pinus radiata D. Don) Compression Woods: A Study Using Variable-Pressure Scanning Electron Microscopy (VP-SEM).

Variable-pressure scanning electron microscopy was used to investigate the dimensional changes in longitudinal, tangential and radial directions, on wetting and drying, of tracheids of opposite wood (OW) and three grades of compression woods (CWs), including severe CW (SCW) and two grades of mild compression wood (MCW) (MCW1 and MCW2) in corewood of radiata pine (Pinus radiata) saplings. The CW was formed on the underside and OW on the upper side of slightly tilted stems. In the longitudinal direction, the shrinkage of SCW tracheids was ~300% greater than that of OW tracheids, with the shrinkage of the MCW1 and MCW2 tracheids being intermediate. Longitudinal swelling was also investigated and hysteresis was demonstrated for the tracheids of all corewood types, with the extent of hysteresis increasing with CW severity. A statistical association was found between longitudinal shrinkage and the content of lignin and galactosyl residues in the cell-wall matrix. The galactosyl residues are present mostly as (1→4)-ß-galactans, which are known to have a high capacity for binding water and swell on hydration. The small proportions of (1→3)-ß-glucans in the CWs have similar properties. These polysaccharides may play a functional role in the longitudinal shrinking and swelling of CW tracheids. Tangential shrinkage of tracheids was greater than radial shrinkage but both were greatest for OW and least for SCW, with the MCW1 and MCW2 being intermediate.

T4 urothelial carcinoma in undiagnosed closed bladder exstrophy in a post-menopausal female.

It is rare to see an adult presenting with exstrophy of the bladder. Malignant conversion in exstrophy occurs in 4%, with adenocarcinoma as the most common histopathology. We report the first case of metastatic high grade urothelial carcinoma with squamous and sarcomatoid differentiation arising from undiagnosed, closed bladder exstrophy in a female at advanced age with associated bilateral deep vein thrombosis and clot retention. The patient developed clinical progression of disease despite neoadjuvant gemcitabine-cisplatin and salvage (or palliative) radiotherapy. To the best of our knowledge, this is the first reported case of a primary urothelial malignancy in occult bladder exstrophy.

Usefulness of Preoperative Ultrasound for the Evaluation of Testicular Rupture in the Setting of Scrotal Gunshot Wounds.

PURPOSE: A scrotal gunshot wound may result in testicular injury, necessitating urgent scrotal exploration and attempted testicular salvage. Scrotal ultrasound is highly sensitive and specific for testicular rupture in the setting of blunt scrotal trauma but it has been poorly studied in the setting of scrotal gunshot wounds. Our objective was to determine the accuracy of scrotal ultrasound to identify testicular rupture following a scrotal gunshot wound. MATERIALS AND METHODS: We retrospectively reviewed the records of patients with a scrotal gunshot wound from 2003 to 2014 in whom preoperative ultrasound was done prior to scrotal exploration. A heterogeneous echo pattern of testicular parenchyma with contour loss was considered a positive examination for testicular rupture. Patients underwent scrotal exploration within 24 hours of presentation. The sensitivity and specificity of ultrasound were estimated and compared to operative findings. ROC curve analysis was done. RESULTS: Of 75 patients who sustained a scrotal gunshot wound ultrasound was positive in 30 and negative in 45. No ultrasound revealed bilateral injuries. Scrotal exploration demonstrated a total of 40 testicular ruptures in 35 patients, of which 30 testicles were salvaged. Ten orchiectomies were performed. The sensitivity and specificity of ultrasound were 60% and 95%, respectively, with 16 missed injuries and 6 false-positive findings. Positive predictive value was 80% and negative predictive value was 87%. The ROC AUC was 0.79. In 6 of the 16 missed injuries there was an ipsilateral hematocele or hematoma. CONCLUSIONS: The sensitivity of scrotal ultrasound is limited for evaluating testicular rupture after a scrotal gunshot wound. Large coincident hematoceles or hematomas may obscure the diagnosis of testicular rupture. Negative ultrasound should not preclude scrotal exploration after a scrotal gunshot wound is sustained.

Isolated Spongy Urethral Rupture from Abrupt Coital Distractive Force.

The classic presentation of penile fracture is a cracking or snap sound, with sharp pain, immediate detumescence, swelling, deformation and ecchymosis. A penile fracture involves rupture of the tunica albuginea of one or both corpora cavernosa. Concomitant urethral rupture is reported to occur in 10% to 20% of penile fracture cases. Isolated urethral injury without penile fracture is extremely rare. We report the first case of isolated pendulous urethral rupture from an abrupt coital distractive force. We include a literature review and discussion of isolated urethral trauma secondary to sexual intercourse. Retrograde urethrography rendered a stunning clinical image which was integral to the diagnosis and management of this patient's injury.

Metastatic Adenocarcinoma of the Prostate Presenting as Supraclavicular and Bulky Generalized Lymphadenopathy with a Benign Digital Rectal Exam.

A 63-year-old male presented with complaints of an enlarging left supraclavicular mass and weight loss. Computed tomography demonstrated a large retroperitoneal mass causing displacement of the adjacent organs, and moderate left hydroureteronephrosis. Multiple pulmonary nodules, lytic spinal lesions, and generalized lymphadenopathy including the left supraclavicular region were seen. Serum prostate-specific antigen level was 2064.0 ng/mL. Digital rectal exam revealed an enlarged prostate without nodularity. Biopsy of the supraclavicular node demonstrated prostatic adenocarcinoma. The diagnosis of lymphoma may be initially suggested, however, prostatic origin should be considered even when the prostate exam is not grossly abnormal.

Location and characterization of lignin in tracheid cell walls of radiata pine (Pinus radiata D. Don) compression woods.

Tilted stems of softwoods form compression wood (CW) and opposite wood (OW) on their lower and upper sides, respectively. More is known about the most severe form of CW, severe CW (SCW), but mild CWs (MCWs) also occur widely. Two grades of MCWs, MCW1 and MCW2, as well as SCW and OW were identified in the stems of radiata pine (Pinus radiata) that had been slightly tilted. The four wood types were identified by the distribution of lignin in the tracheid walls determined by fluorescence microscopy. A solution of the fluorescent dye acridine orange (AO) (0.02% at pH 6 or 7) was shown to metachromatically stain the tracheid walls and can also be used to determine lignin distribution. The lignified walls fluoresced orange to yellow depending on the lignin concentration. Microscopically well-characterized discs (0.5 mm diameter) of the wood types were used to determine lignin concentrations and lignin monomer compositions using the acetyl bromide method and thioacidolysis, respectively. Lignin concentration and the proportion of p-hydroxyphenyl units (H-units) relative to guaiacyl (G-units) increased with CW severity, with <1% H-units in OW and up to 14% in SCW. Lignin H-units can be used as a marker for CW and CW severity. Similar discs were also examined by Raman and FTIR micro-spectroscopies coupled with principal component analysis (PCA) to determine if these techniques can be used to differentiate the four different wood types. Both techniques were able to do this, particularly Raman micro-spectroscopy.

Improved diagnostic accuracy when combining computed tomography angiography and corrected coronary opacification in patients with coronary stents.

Background The accuracy of coronary computed tomography angiography (CCTA) is sub-optimal in patients with coronary stents. Methods that can increase its diagnostic accuracy are desirable. Objective A proof-of-concept study was undertaken to determine if corrected coronary opacification (CCO) differences can improve the accuracy of CCTA in stented coronary arteries. Methods PCI patients who underwent both CCTA and invasive coronary angiography (ICA) within 3 months were analyzed. Coronary luminal attenuation values (normalized to the aorta) were measured proximally and distally to coronary stents. CCO differences were evaluated for ability to predict (i) stenosis on invasive angiography, (ii) abnormal resting coronary flow as measured by the corrected thrombolysis in myocardial infarction (TIMI) frame count (cTFC), and (iii) the combination of abnormal resting flow and significant stenosis on invasive angiography. Results Twenty-nine stented coronary arteries (n = 25, mean age =61.4 years, men =80.0%) were assessed. In stented coronary vessels, CCO identified stenosis (≥ 70%) with an area under the curve of 0.767 (P = 0.021). CCO predicted abnormal resting coronary flow with high accuracy (AUC =0.867, P = 0.002). Combined CCTA/CCO identified both abnormal cTFC and stenosis ≥70% on ICA (functionally significant stenosis) with diagnostic accuracy of 92.3%. In contrast, CCTA visual assessment alone had lower diagnostic accuracy of 66.7% for identifying functionally significant stenosis. Conclusion CCO differences are predictive of abnormal resting flow and consequently, in-stent restenosis. Incorporation of this technique may improve the specificity of CCTA in PCI patients.

Tracheid cell-wall structures and locations of (1 → 4)-ß-D-galactans and (1 → 3)-ß-D-glucans in compression woods of radiata pine (Pinus radiata D. Don).

BACKGROUND: Compression wood (CW) forms on the underside of tilted stems of coniferous gymnosperms and opposite wood (OW) on the upperside. The tracheid walls of these wood types differ structurally and chemically. Although much is known about the most severe form of CW, severe CW (SCW), mild CWs (MCWs), also occur, but less is known about them. In this study, tracheid wall structures and compositions of two grades of MCWs (1 and 2) and SCW were investigated and compared with OW in slightly tilted radiata pine (Pinus radiata) stems. RESULTS: The four wood types were identified by the distribution of lignin in their tracheid walls. Only the tracheid walls of OW and MCW1 had a S3 layer and this was thin in MCW1. The tracheid walls of only SCW had a S2 layer with helical cavities in the inner region (S2i). Using immunomicroscopy, (1 → 4)-ß-D-galactans and (1 → 3)-ß-D-glucans were detected in the tracheid walls of all CWs, but in only trace amounts in OW. The (1 → 4)-ß-D-galactans were located in the outer region of the S2 layer, whereas the (1 → 3)-ß-D-glucans were in the inner S2i region. The areas and intensities of labelling increased with CW severity. The antibody for (1 → 4)-ß-D-galactans was also used to identify the locations and relative amounts of these galactans in whole stem cross sections based on the formation of an insoluble dye. Areas containing the four wood types were clearly differentiated depending on colour intensity. The neutral monosaccharide compositions of the non-cellulosic polysaccharides of these wood types were determined on small, well defined discs, and showed the proportion of galactose was higher for CWs and increased with severity. CONCLUSION: The presence of an S3 wall layer is a marker for very MCW and the presence of helical cavities in the S2 wall layer for SCW. The occurrence and proportions of (1 → 4)-ß-D-galactans and (1 → 3)-ß-D-glucans can be used as markers for CW and its severity. The proportions of galactose were consistent with the labelling results for (1 → 4)-ß-D-galactans.

Atrioventricular block as the initial manifestation of cardiac sarcoidosis in middle-aged adults.

INTRODUCTION: Atrioventricular block (AVB) can be caused by several conditions, including cardiac sarcoidosis (CS). The prevalence of CS causing this presentation in a North American population has not been investigated and was the purpose of this study. METHODS: We prospectively evaluated patients aged 18-60 years presenting with unexplained 2nd or 3rd degree AVB and no previous history of sarcoidosis in any organ. All patients had fluorodeoxyglucose-positron emission tomography (FDG-PET) scans for the evaluation of CS. Japanese Ministry of Health Welfare (JMHW) criteria and biopsy results were used to confirm the diagnosis of CS. Subjects with advanced imaging suggestive of CS were investigated for extracardiac involvement. Patients were followed for major adverse cardiac events. RESULTS: Thirty-two patients presenting with unexplained AVB underwent cardiac and whole body FDG-PET for the investigation of CS from February 2010 to June 2013. Mean age was 52.8 ± 6.2 years, and 20 were male. CS was diagnosed in 11/32 (34%) subjects and 11/11 were subsequently diagnosed with extra-CS. Average follow-up was 21 ± 9 months. Adverse events were observed in 3 subjects with CS but none in subjects with idiopathic AVB. All 3 patients presented with heart failure, 2 also had recurrent VT resulting in ICD shocks. CONCLUSIONS: In this prospective study of consecutive patients aged ≤60 years presenting with unexplained AVB, we found that 11/32 (34%) had previously undiagnosed CS. Among patients with CS, 3/11 had adverse clinical outcomes compared with 0/21 (P = 0.011). Our data suggest that all patients aged ≤60 years with unexplained AVB should be investigated for CS. Moreover, patients diagnosed with CS should be closely followed.

Clinical interpretation standards and quality assurance for the multicenter PET/CT trial rubidium-ARMI.

UNLABELLED: Rubidium-ARMI ((82)Rb as an Alternative Radiopharmaceutical for Myocardial Imaging) is a multicenter trial to evaluate the accuracy, outcomes, and cost-effectiveness of low-dose (82)Rb perfusion imaging using 3-dimensional (3D) PET/CT technology. Standardized imaging protocols are essential to ensure consistent interpretation. METHODS: Cardiac phantom qualifying scans were obtained at 7 recruiting centers. Low-dose (10 MBq/kg) rest and pharmacologic stress (82)Rb PET scans were obtained in 25 patients at each site. Summed stress scores, summed rest scores, and summed difference scores (SSS, SRS, and SDS [respectively] = SSS-SRS) were evaluated using 17-segment visual interpretation with a discretized color map. All scans were coread at the core lab (University of Ottawa Heart Institute) to assess agreement of scoring, clinical diagnosis, and image quality. Scoring differences greater than 3 underwent a third review to improve consensus. Scoring agreement was evaluated with intraclass correlation coefficient (ICC-r), concordance of clinical interpretation, and image quality using κ coefficient and percentage agreement. Patient (99m)Tc and (201)Tl SPECT scans (n = 25) from 2 centers were analyzed similarly for comparison to (82)Rb. RESULTS: Qualifying scores of SSS = 2, SDS = 2, were achieved uniformly at all imaging sites on 9 different 3D PET/CT scanners. Patient scores showed good agreement between core and recruiting sites: ICC-r = 0.92, 0.77 for SSS, SDS. Eighty-five and eighty-seven percent of SSS and SDS scores, respectively, had site-core differences of 3 or less. After consensus review, scoring agreement improved to ICC-r = 0.97, 0.96 for SSS, SDS (P < 0.05). The agreement of normal versus abnormal (SSS ≥ 4) and nonischemic versus ischemic (SDS ≥ 2) studies was excellent: ICC-r = 0.90 and 0.88. Overall interpretation showed excellent agreement, with a κ = 0.94. Image quality was perceived differently by the site versus core reviewers (90% vs. 76% good or better; P < 0.05). By comparison, scoring agreement of the SPECT scans was ICC-r = 0.82, 0.72 for SSS, SDS. Seventy-six and eighty-eight percent of SSS and SDS scores, respectively, had site-core differences of 3 or less. Consensus review again improved scoring agreement to ICC-r = 0.97, 0.90 for SSS, SDS (P < 0.05). CONCLUSION: (82)Rb myocardial perfusion imaging protocols were implemented with highly repeatable interpretation in centers using 3D PET/CT technology, through an effective standardization and quality assurance program. Site scoring of (82)Rb PET myocardial perfusion imaging scans was found to be in good agreement with core lab standards, suggesting that the data from these centers may be combined for analysis of the rubidium-ARMI endpoints.

Cardiac PET: metabolic and functional imaging of the myocardium.

Cardiac PET has evolved over the past 30 years to gain wider acceptance as a valuable modality for a variety of cardiac conditions. Wider availability of scanners as well as changes in reimbursement policies in more recent years has further increased its use. Moreover, with the emergence of novel radionuclides as well as further advances in scanner technology, the use of cardiac PET can be expected to increase further in both clinical practice and the research arena. PET has demonstrated superior diagnostic accuracy for the diagnosis of coronary artery disease in comparison with single-photon emission tomography while it provides robust prognostic value. The addition of absolute flow quantification increases sensitivity for 3-vessel disease as well as providing incremental functional and prognostic information. Metabolic imaging using (18)F-fluorodeoxyglucose can be used to guide revascularization in the setting of heart failure and also to detect active inflammation in conditions such as cardiac sarcoidosis and within atherosclerotic plaque, improving our understanding of the processes that underlie these conditions. However, although the pace of new developments is rapid, there remains a gap in evidence for many of these advances and further studies are required.

Evidence of enhanced serum amino acid profile but not appetite suppression by dietary glycomacropeptide (GMP): a comparison of dairy whey proteins.

OBJECTIVE: There is evidence that high-protein foods increase satiety and may aid weight loss, yet little is known of differential effects of protein composition. The aim of the study was to compare the acute effects of 4 whey proteins on satiety and food intake and to evaluate possible relationships with postprandial serum amino acid concentrations. METHODS: Isoenergetic high-protein shakes (∼1 MJ) containing 25 g whey protein were given to 18 lean male participants using a crossover design. Three protein fractions identified as satiating in a rat model, glycomacropeptide (GMP), beta-lactoglobulin (ß-lac), and colostrum whey protein concentrate (WPC), were compared with a WPC control. A standardized 2.5MJ breakfast was given at 0830 hours, followed by the preload beverages at 1130 hours. Participants rated appetite sensations using visual analogue scales (VAS) prior to the beverage (baseline, 0 minutes) and then at 15, 30, 45, 60, 90, 150, and 210 minutes. Energy and macronutrient intake was measured by covert weighing of an ad libitum lunch meal at 90 minutes. Repeat blood samples were collected via venous cannulation. RESULTS: Serum amino acid (a.a.) concentrations differed between whey fractions (p=0.012) and were higher following GMP compared to ß-lac (p=0.051) and colostrum WPC (p=0.044) but not the WPC control (p=0.20). There was no difference in VAS-rated hunger, satisfaction, or thoughts of food between whey fractions, but fullness did differ (p=0.032) and was highest following the ß-lac beverage. Energy intake was not suppressed relative to control by any of the 3 whey fractions. CONCLUSIONS: We conclude that total serum a.a. concentration was a poor indicator of satiety, with little evidence of differential satiety between these whey proteins other than a modest enhancement of fullness by ß-lac.

Histomorphometric evaluation of the effect of early exercise on subchondral vascularity in the third carpal bone of horses.

OBJECTIVE: To investigate histomorphometric changes in the cartilage and subchondral bone of the third carpal bone associated with conditioning exercise in young Thoroughbreds. ANIMALS: Nine 18-month-old Thoroughbreds. Procedures-Both third carpal bones of 9 horses (4 exercised spontaneously at pasture only and 5 given additional conditioning exercise beginning at a mean age of 3 weeks) were evaluated. Histomorphometric variables (hyaline and calcified cartilage thickness and collagen orientation; vascular channel area, number, and orientation; and osteochondral junction rugosity) of the third carpal bone, sampled at 4 dorsopalmar sites in the radial facet, were compared between the exercised and nonexercised groups. RESULTS: The vascular channel area measured at the 4 dorsopalmar sites was larger in the exercised group than in the control group, but none of the variables were significantly different between groups. Both groups had significant site-specific variations in all measured variables. Most importantly, the vascular channel area was highest in the most dorsal aspect. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the mild exercise imposed in both groups during the developmental period appeared to be associated with an increase in the vascular channel area beneath the calcified cartilage layer in the third carpal bone. This increased vascular channel area could also be associated with high stress in the dorsal aspect of the radial facet, a region that is known to be vulnerable to osteochondral fragmentation.

The role of noninvasive imaging in coronary artery disease detection, prognosis, and clinical decision making.

A vast array of noninvasive imaging modalities is available for the evaluation of the presence and severity of coronary artery disease (CAD). Choosing the right test can be challenging but is critical for proper patient diagnosis and management. Presently available imaging tests for CAD include: (1) nuclear myocardial perfusion imaging procedures (single-photon emission tomography) and positron emission tomography, (2) stress echocardiography, (3) computed tomography coronary angiography, and (4) cardiac magnetic resonance imaging. Exercise treadmill testing electrocardiography is another alternative that we will discuss briefly. Selection of the most appropriate imaging modality requires knowledge of the clinical question being addressed, patient characteristics (pretest probability and prevalence of disease), the strengths, limitations, risks, costs, and availability of each procedure. To assist with test selection, we review the relevant literature in detail to consider the relative merits of cardiac imaging modalities for: (1) detection of CAD, (2) risk stratification and prognostication, and (3) guiding clinical decision making.

The implantable defibrillator and return to operation of vehicles study.

AIMS: We sought to characterise driving habits of contemporary implantable cardioverter defibrillator (ICD) patients. METHODS AND RESULTS: We performed a multicentre prospective observational study of consecutive ICD recipients. Non-commercial drivers with a valid licence were eligible. Patient and ICD data were recorded. All patients completed an anonymous questionnaire regarding their driving habits. Among 275 patients, 25 (9.1%) stopped driving permanently after ICD implantation. During a mean follow-up of 26.5 ± 4.5 months, 25.3% of patients received an ICD shock (52.5% appropriate). The median time to first shock was 7.0 (2.5, 17.5) months and was not significantly different between primary and secondary ICD patients. However, shocks (36.5 vs. 21.3%, P = 0.027) and recurrent shock episodes (17.5 vs. 6.2%, P = 0.011) were more common in secondary ICD patients. Physician-recommended driving restrictions were not recalled by 37.9% and not followed by 23.0% of patients. Overall, the mean duration of driving abstinence was 2.2 ± 2.9 and 3.6 ± 5.3 months for primary and secondary patients, respectively. Notably, 36.5% of secondary patients drove within 1 month. Eight patients (3.3%) received a shock while driving, five of which resulted in road traffic accidents. The annual risk of a shock while driving was 1.5%. CONCLUSIONS: Patient driving behaviour following ICD implantation is variable, with over one-third not remembering and almost one-quarter not adhering to physician-directed driving restrictions. Over one-third of secondary ICD patients drive within 1 month despite physician recommendations. Further studies are required to establish the optimal duration of driving restriction in ICD recipients.