The use of cone-beam computed tomography (CBCT) in radiocarpal fractures: a diagnostic test accuracy meta-analysis.

OBJECTIVE: Occult radiocarpal fractures often present a diagnostic challenge to the emergency department. Accurate diagnosis of these injuries is crucial as a missed fracture can lead to significant morbidity. Cone-beam CT (CBCT) scan is a novel imaging modality, with minimal radiation exposure and comparatively fast acquisition time. Our aim was to evaluate its use in the diagnosis of cortical fractures in the upper limb extremity. MATERIALS AND METHODS: We conducted a systematic review of literature and included all studies that evaluated the use of CBCT in the diagnosis of radiocarpal fractures. We used a mixed-effects logistic regression bivariate model to estimate the summary sensitivity and specificity and constructed hierarchical summary receiver operative characteristic curves (HSROC). RESULTS: We identified 5 studies, with 439 patients, and observed CBCT to be 87.7% (95% CI 77.6-93.6) sensitive and 99.2% (95% CI 92.6-99.9) specific for scaphoid fractures. For carpal fractures, CBCT was observed to have a pooled sensitivity and specificity of 90.6% (95% CI 72.7-97.2) and 100% (95% CI 99-100) respectively. For distal radius fractures, CBCT sensitivity was 90% (95% CI 67-98) and specificity was 100% (95% CI 10-100). The overall inter-rater agreement effect was shown to be 0.89 (95% CI 0.82-0.96), which is deemed to be almost perfect. CONCLUSION: CBCT is an accurate diagnostic tool for occult radiocarpal cortical fractures, which could replace or supplement radiographs. We believe CBCT has a promising role in the acute radiocarpal fracture diagnostic algorithm in both emergency and trauma departments.

Collagen fibre-mediated mechanical damage increases calcification of bovine pericardium for use in bioprosthetic heart valves.

In cases of aortic stenosis, bioprosthetic heart valves (BHVs), with glutaraldehyde-fixed bovine pericardium leaflets (GLBP), are often implanted to replace the native diseased valve. Widespread use of BHVs, however, is restricted due to inadequate long-term durability, owing specifically to premature leaflet failure. Mechanical fatigue damage and calcification remain the primary leaflet failure modes, where glutaraldehyde treatment is known to accelerate calcification. The literature in this area is limited, with some studies suggesting mechanical damage increases calcification and others that they are independent degenerative mechanisms. In this study, specimens which were non-destructively pre-sorted according to collagen fibre architecture and uniaxially cyclically loaded until failure or 1 million cycles, were placed in an in vitro calcification solution. The weakest specimen group (those with fibres aligned perpendicular to the load) had statistically significantly higher volumes of calcification when compared to those with a high fatigue life. Moreover, SEM imaging revealed that ruptured and damaged fibres presented calcium binding sites; resulting in 4 times more calcification in fractured samples in comparison to those which did not fail by fatigue. To the authors' knowledge, this study quantifies for the first time, that mechanical damage drives calcification in commercial-grade GLBP and that calcification varies spatially according to localised damage levels. These findings illustrate that not only is calcification of GLBP exacerbated by fatigue damage, but that both failure phenomena are underpinned by the collagen fibre organisation. Consequently, controlling for GLBP collagen fibre architecture in leaflets could minimise the progression of these primary failure modes in patient BHVs. STATEMENT OF SIGNIFICANCE: Mechanical damage and calcification are the primary premature failure modes of glutaraldehyde-fixed bovine pericardial (GLBP) leaflets in bioprosthetic heart valves. In this study, commercial-grade GLBP specimens which were uniaxially cyclically loaded to failure or 1 million cycles, were placed in an in vitro calcification solution. MicroCT and SEM analysis showed that localised calcification levels varied spatially according to damage, where ruptured fibres offered additional calcium binding sites. Furthermore, specimens with a statistically significant lower fatigue life were associated with statistically significant higher calcification. This study revealed that mechanical damage drives calcification of GLBP. Non-destructive pre-screening of collagen fibres demonstrated that both the fatigue life and calcification potential of commercial-grade GLBP, are underpinned by the collagen fibre architecture.

Disease-Relevant Single Cell Photonic Signatures Identify S100ß Stem Cells and their Myogenic Progeny in Vascular Lesions.

A hallmark of subclinical atherosclerosis is the accumulation of vascular smooth muscle cell (SMC)-like cells leading to intimal thickening and lesion formation. While medial SMCs contribute to vascular lesions, the involvement of resident vascular stem cells (vSCs) remains unclear. We evaluated single cell photonics as a discriminator of cell phenotype in vitro before the presence of vSC within vascular lesions was assessed ex vivo using supervised machine learning and further validated using lineage tracing analysis. Using a novel lab-on-a-Disk(Load) platform, label-free single cell photonic emissions from normal and injured vessels ex vivo were interrogated and compared to freshly isolated aortic SMCs, cultured Movas SMCs, macrophages, B-cells, S100ß+ mVSc, bone marrow derived mesenchymal stem cells (MSC) and their respective myogenic progeny across five broadband light wavelengths (λ465 - λ670 ± 20 nm). We found that profiles were of sufficient coverage, specificity, and quality to clearly distinguish medial SMCs from different vascular beds (carotid vs aorta), discriminate normal carotid medial SMCs from lesional SMC-like cells ex vivo following flow restriction, and identify SMC differentiation of a series of multipotent stem cells following treatment with transforming growth factor beta 1 (TGF- ß1), the Notch ligand Jagged1, and Sonic Hedgehog using multivariate analysis, in part, due to photonic emissions from enhanced collagen III and elastin expression. Supervised machine learning supported genetic lineage tracing analysis of S100ß+ vSCs and identified the presence of S100ß+vSC-derived myogenic progeny within vascular lesions. We conclude disease-relevant photonic signatures may have predictive value for vascular disease.

The calcium binding protein S100ß marks hedgehog-responsive resident vascular stem cells within vascular lesions.

A hallmark of subclinical atherosclerosis is the accumulation of vascular smooth muscle cell (SMC)-like cells leading to intimal thickening. While medial SMCs contribute, the participation of hedgehog-responsive resident vascular stem cells (vSCs) to lesion formation remains unclear. Using transgenic eGFP mice and genetic lineage tracing of S100ß vSCs in vivo, we identified S100ß/Sca1 cells derived from a S100ß non-SMC parent population within lesions that co-localise with smooth muscle α-actin (SMA) cells following iatrogenic flow restriction, an effect attenuated following hedgehog inhibition with the smoothened inhibitor, cyclopamine. In vitro, S100ß/Sca1 cells isolated from atheroprone regions of the mouse aorta expressed hedgehog signalling components, acquired the di-methylation of histone 3 lysine 4 (H3K4me2) stable SMC epigenetic mark at the Myh11 locus and underwent myogenic differentiation in response to recombinant sonic hedgehog (SHh). Both S100ß and PTCH1 cells were present in human vessels while S100ß cells were enriched in arteriosclerotic lesions. Recombinant SHh promoted myogenic differentiation of human induced pluripotent stem cell-derived S100ß neuroectoderm progenitors in vitro. We conclude that hedgehog-responsive S100ß vSCs contribute to lesion formation and support targeting hedgehog signalling to treat subclinical arteriosclerosis.

Resident multipotent vascular stem cells exhibit amplitude dependent strain avoidance similar to that of vascular smooth muscle cells.

Atherosclerosis is one of the leading causes of mortality worldwide, and presents as a narrowing or occlusion of the arterial lumen. Interventions to re-open the arterial lumen can result in re-occlusion through intimal hyperplasia. Historically only de-differentiated vascular smooth muscle cells were thought to contribute to intimal hyperplasia. However recent significant evidence suggests that resident medial multipotent vascular stem cells (MVSC) may also play a role. We therefore investigated the strain response of MVSC since these resident cells are also subjected to strain within their native environment. Accordingly, we applied uniaxial 1 Hz cyclic uniaxial tensile strain at three amplitudes around a mean strain of 5%, (4-6%, 2-8% and 0-10%) to either rat MVSC or rat VSMC before their strain response was evaluated. While both cell types strain avoid, the strain avoidant response was greater for MVSC after 24 h, while VSMC strain avoid to a greater degree after 72 h. Additionally, both cell types increase strain avoidance as strain amplitude is increased. Moreover, MVSC and VSMC both demonstrate a strain-induced decrease in cell number, an effect more pronounced for MVSC. These experiments demonstrate for the first time the mechano-sensitivity of MVSC that may influence intimal thickening, and emphasizes the importance of strain amplitude in controlling the response of vascular cells in tissue engineering applications.

Alcohol Reduces Arterial Remodeling by Inhibiting Sonic Hedgehog-Stimulated Stem Cell Antigen-1 Positive Progenitor Stem Cell Expansion.

BACKGROUND: Cell and molecular mechanisms mediating the cardiovascular effects of alcohol are not fully understood. Our aim was to determine the effect of moderate ethanol (EtOH) on sonic hedgehog (SHh) signaling in regulating possible stem cell antigen-1 positive (Sca1+ ) progenitor stem cell involvement during pathologic arterial remodeling. METHODS: Partial ligation or sham operation of the left carotid artery was performed in transgenic Sca1-enhanced green fluorescent protein (eGFP) mice gavaged with or without "daily moderate" EtOH. RESULTS: The EtOH group had reduced adventitial thickening and less neointimal formation, compared to ligated controls. There was expansion of eGFP-expressing (i.e., Sca1+ ) cells in remodeled vessels postligation (day 14), especially in the neo intima. EtOH treatment reduced the number of Sca1+ cells in ligated vessel cross-sections concomitant with diminished remodeling, compared to control ligated vessels. Moreover, EtOH attenuated SHh signaling in injured carotids as determined by immunohistochemical analysis of the target genes patched 1 and Gli2, and RT-PCR of whole-vessel Gli2 mRNA levels. Intraperitoneal injection of ligated Sca1-eGFP mice with the SHh signaling inhibitor cyclopamine diminished SHh target gene expression, reduced the number of Sca1+ cells, and ameliorated carotid remodeling. EtOH treatment of purified Sca1+ adventitial progenitor stem cells in vitro inhibited SHh signaling, and their rSHh-induced differentiation to vascular smooth muscle cells. CONCLUSIONS: EtOH reduces SHh-responsive Sca1+ progenitor cell myogenic differentiation/expansion in vitro and during arterial remodeling in response to ligation injury in vivo. Regulation of vascular Sca1+ progenitor cells in this way may be an important novel mechanism contributing to alcohol's cardiovascular protective effects.

Hedgehog and Resident Vascular Stem Cell Fate.

The Hedgehog pathway is a pivotal morphogenic driver during embryonic development and a key regulator of adult stem cell self-renewal. The discovery of resident multipotent vascular stem cells and adventitial progenitors within the vessel wall has transformed our understanding of the origin of medial and neointimal vascular smooth muscle cells (SMCs) during vessel repair in response to injury, lesion formation, and overall disease progression. This review highlights the importance of components of the Hh and Notch signalling pathways within the medial and adventitial regions of adult vessels, their recapitulation following vascular injury and disease progression, and their putative role in the maintenance and differentiation of resident vascular stem cells to vascular lineages from discrete niches within the vessel wall.

Drinking speed using a Pat Saunders valved straw, wide-bore straw and a narrow-bore straw in a normal adult population.

BACKGROUND: Straw drinking is often recommended as a strategy for managing swallowing difficulties in adult clinical populations. This study presents a range of normal adult straw drinking speeds and discusses clinical applications. METHOD: Straw drinking speed in a normal healthy population of 70 adults from 18 to 95 years of age was measured. Three types of straws were used: a Pat Saunders valved straw (PSVS), a wide-bore straw and a narrow-bore straw (NBS). Participants drank 40  ml of water for each straw tested. All participants were asked to comment on the straws used. A mixed-method design was used wherein both quantitative and simple structured qualitative data were collected. RESULTS: Drinking speed was quickest for the wide-bore straw, followed by the NBS and slowest for the PSVS. This was supported by qualitative comments from the adults who reported that the PSVS was the most difficult straw to use. There were no significant differences between straw flow or straw type and sex of the participants. There were significant changes with aging and a decrease in flow speed with the NBS. Weight and height had some effect on straw drinking speeds. There was a slight correlation between age and sex and age and height, but not between age and weight. CONCLUSION: This article presents data for a normal range of straw drinking speeds in a healthy adult population. It can be used in the assessment and monitoring of straw drinking in acquired disorders of swallowing.

Adult vascular smooth muscle cells in culture express neural stem cell markers typical of resident multipotent vascular stem cells.

Differentiation of resident multipotent vascular stem cells (MVSCs) or de-differentiation of vascular smooth muscle cells (vSMCs) might be responsible for the SMC phenotype that plays a major role in vascular diseases such as arteriosclerosis and restenosis. We examined vSMCs from three different species (rat, murine and bovine) to establish whether they exhibit neural stem cell characteristics typical of MVSCs. We determined their SMC differentiation, neural stem cell marker expression and multipotency following induction in vitro by using immunocytochemistry, confocal microscopy, fluorescence-activated cell sorting analysis and quantitative real-time polymerase chain reaction. MVSCs isolated from rat aortic explants, enzymatically dispersed rat SMCs and rat bone-marrow-derived mesenchymal stem cells served as controls. Murine carotid artery lysates and primary rat aortic vSMCs were both myosin-heavy-chain-positive but weakly expressed the neural crest stem cell marker, Sox10. Each vSMC line examined expressed SMC differentiation markers (smooth muscle α-actin, myosin heavy chain and calponin), neural crest stem cell markers (Sox10(+), Sox17(+)) and a glia marker (S100ß(+)). Serum deprivation significantly increased calponin and myosin heavy chain expression and decreased stem cell marker expression, when compared with serum-rich conditions. vSMCs did not differentiate to adipocytes or osteoblasts following adipogenic or osteogenic inductive stimulation, respectively, or respond to transforming growth factor-ß1 or Notch following γ-secretase inhibition. Thus, vascular SMCs in culture express neural stem cell markers typical of MVSCs, concomitant with SMC differentiation markers, but do not retain their multipotency. The ultimate origin of these cells might have important implications for their use in investigations of vascular proliferative disease in vitro.

Embryonic rat vascular smooth muscle cells revisited - a model for neonatal, neointimal SMC or differentiated vascular stem cells?

BACKGROUND: The A10 and A7r5 cell lines derived from the thoracic aorta of embryonic rat are widely used as models of non-differentiated, neonatal and neointimal vascular smooth muscle cells in culture. The recent discovery of resident multipotent vascular stem cells within the vessel wall has necessitated the identity and origin of these vascular cells be revisited. In this context, we examined A10 and A7r5 cell lines to establish the similarities and differences between these cell lines and multipotent vascular stem cells isolated from adult rat aortas by determining their differentiation state, stem cell marker expression and their multipotency potential in vitro. METHODS: Vascular smooth muscle cell differentiation markers (alpha-actin, myosin heavy chain, calponin) and stem cell marker expression (Sox10, Sox17 and S100ß) were assessed using immunocytochemistry, confocal microscopy, FACS analysis and real-time quantitative PCR. RESULTS: Both A10 and A7r5 expressed vascular smooth muscle differentiation, markers, smooth muscle alpha - actin, smooth muscle myosin heavy chain and calponin. In parallel analysis, multipotent vascular stem cells isolated from rat aortic explants were immunocytochemically myosin heavy chain negative but positive for the neural stem cell markers Sox10+, a neural crest marker, Sox17+ the endoderm marker, and the glia marker, S100ß+. This multipotent vascular stem cell marker profile was detected in both embryonic vascular cell lines in addition to the adventitial progenitor stem cell marker, stem cell antigen-1, Sca1+. Serum deprivation resulted in a significant increase in stem cell and smooth muscle cell differentiation marker expression, when compared to serum treated cells. Both cell types exhibited weak multipotency following adipocyte inductive stimulation. Moreover, Notch signaling blockade following γ-secretase inhibition with DAPT enhanced the expression of both vascular smooth muscle and stem cell markers. CONCLUSIONS: We conclude that A10 and A7r5 cells share similar neural stem cell markers to both multipotent vascular stem cells and adventitial progenitors that are indicative of neointimal stem-derived smooth muscle cells. This may have important implications for their use in examining vascular contractile and proliferative phenotypes in vitro.

Incidence of congenital cytomegalovirus infection in Ireland: implications for screening and diagnosis.

BACKGROUND: Congenital cytomegalovirus (cCMV) causes serious intrauterine infection and is the leading cause of sensorineural hearing loss. In the absence of routine screening, asymptomatic infections, which constitute approximately 90% of all cCMV cases, remain undiagnosed; however many clinical abnormalities manifest later in childhood. OBJECTIVES: The aims of the present study were to determine, for the first time, the incidence of cCMV infection in a large maternity hospital in Dublin city and the optimal sampling method for neonatal screening. STUDY DESIGN: A pilot screening study of asymptomatic infants born was conducted over a 12-month period. Mothers were consented and neonates screened for evidence of CMV infection (n=1044). Urine or saliva was tested for the presence of CMV DNA and reactive results were confirmed with follow-up testing and clinical evaluation. RESULTS: cCMV incidence in the asymptomatic neonates screened was 0.19%. An overall cCMV incidence was extrapolated based on the total number of live-births and data from those infants routinely screened for cCMV during the study period, and estimated as 0.23%. Neonatal urine collection proved prohibitive to mass screening. However, testing of saliva for CMV DNA was rapid, sensitive and suitable for screening. Furthermore, in a low prevalence population, pooling of patient samples proved effective and cost-efficient. CONCLUSIONS: The present study concluded that there is a significant burden of undiagnosed cCMV infection in Ireland. The introduction of neonatal CMV DNA testing of saliva is viable, and could be considered as part of the national newborn screening programme, following a cost-benefit analysis.

Preoperative atrial histological changes are not associated with postoperative atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) remains the most common complication of cardiac surgery. Prophylactic therapies have been studied, but their utility has been limited by the inability to accurately identify patients who will develop this complication. Recent studies have suggested that atrial myolysis and lipofuscin pigmentation are associated with post-coronary artery bypass grafting (CABG) AF. We sought to determine whether there is an association between preoperative atrial histology and subsequent post-CABG AF. METHODS: Samples of right atrial appendage were obtained from 94 patients undergoing CABG. Tissue was formalin fixed and paraffin embedded. Sections 4 mum thick were cut, stained with hematoxylin and eosin, and examined for the following parameters: fibrosis, myolysis, inflammation, nuclear size, pericardial exudates, lipofuscin pigment, arteriolar hypertrophy, contraction banding, mesothelial hyperplasia, and atrial diverticula. Results were graded as absent, mild, moderate, or severe by two independent observers who were blinded to the clinical outcomes. Univariate and multivariate analyses were carried out. RESULTS: Thirty-six (38%) patients developed AF. No correlation was found between the 10 features assessed, including myolysis and lipofuscin pigmentation, and the development of AF. CONCLUSION: Simple morphology of right atrial appendages does not predict the development of postoperative AF.