Lipid-based and protein-based interactions synergize transmembrane signaling stimulated by antigen clustering of IgE receptors.

Antigen (Ag) crosslinking of immunoglobulin E-receptor (IgE-FcεRI) complexes in mast cells stimulates transmembrane (TM) signaling, requiring phosphorylation of the clustered FcεRI by lipid-anchored Lyn tyrosine kinase. Previous studies showed that this stimulated coupling between Lyn and FcεRI occurs in liquid ordered (Lo)-like nanodomains of the plasma membrane and that Lyn binds directly to cytosolic segments of FcεRI that it initially phosphorylates for amplified activity. Net phosphorylation above a nonfunctional threshold is achieved in the stimulated state but not in the resting state, and current evidence supports the hypothesis that this relies on Ag crosslinking to disrupt a balance between Lyn and tyrosine phosphatase activities. However, the structural interactions that underlie the stimulation process remain poorly defined. This study evaluates the relative contributions and functional importance of different types of interactions leading to suprathreshold phosphorylation of Ag-crosslinked IgE-FcεRI in live rat basophilic leukemia mast cells. Our high-precision diffusion measurements by imaging fluorescence correlation spectroscopy on multiple structural variants of Lyn and other lipid-anchored probes confirm subtle, stimulated stabilization of the Lo-like nanodomains in the membrane inner leaflet and concomitant sharpening of segregation from liquid disordered (Ld)-like regions. With other structural variants, we determine that lipid-based interactions are essential for access by Lyn, leading to phosphorylation of and protein-based binding to clustered FcεRI. By contrast, TM tyrosine phosphatase, PTPα, is excluded from these regions due to its Ld-preference and steric exclusion of TM segments. Overall, we establish a synergy of lipid-based, protein-based, and steric interactions underlying functional TM signaling in mast cells.

Higher Anti-tumor Necrosis Factor-α Levels Correlate With Improved Radiologic Outcomes in Crohn's Perianal Fistulas.

BACKGROUND & AIMS: Higher anti-tumor necrosis factor-α (TNF) drug levels are associated with improved clinical healing of Crohn's perianal fistulas. It is unclear whether this leads to improved healing on radiologic assessment. We aimed to evaluate the association between anti-TNF drug levels and radiologic outcomes in perianal fistulising Crohn's disease. METHODS: A cross-sectional retrospective multicenter study was undertaken. Patients with perianal fistulising Crohn's disease on maintenance infliximab or adalimumab, with drug levels within 6 months of perianal magnetic resonance imaging were included. Patients receiving dose changes or fistula surgery between drug level and imaging were excluded. Radiologic disease activity was scored using the Van Assche Index, with an inflammatory subscore calculated using indices: T2-weighted imaging hyperintensity, collections >3 mm diameter, rectal wall involvement. Primary endpoint was radiologic healing (inflammatory subscore ≤6). Secondary endpoint was radiologic remission (inflammatory subscore = 0). RESULTS: Of 193 patients (infliximab, n = 117; adalimumab, n = 76), patients with radiologic healing had higher median drug levels compared with those with active disease (infliximab 6.0 vs 3.9 µg/mL; adalimumab 9.1 vs 6.2 µg/mL; both P < .05). Patients with radiologic remission also had higher median drug levels compared with those with active disease (infliximab 7.4 vs 3.9 µg/mL; P < .05; adalimumab 9.8 vs 6.2 µg/mL; P = .07). There was a significant incremental reduction in median inflammatory subscores with higher anti-TNF drug level tertiles. CONCLUSIONS: Higher anti-TNF drug levels were associated with improved radiologic outcomes on magnetic resonance imaging in perianal fistulising Crohn's disease, with an incremental improvement at higher drug level tertiles for both infliximab and adalimumab.

From self-defeating to other defeating: Examining the effects of leader procrastination on follower work outcomes.

This research examines the influence of leader procrastination on employee attitudes and behaviours. While previous studies have typically viewed procrastination as a form of self-defeating behaviour, this research explores its effects on others in the workplace. In Study 1, using data collected from 290 employees, we demonstrate the discriminant and relative predictive validity of leader procrastination on leadership effectiveness compared with laissez-faire leadership and directive leadership. In Study 2, based on dyadic data collected in three phases from 250 employees and their 23 supervisors, we found that leader procrastination was associated with follower discretionary behaviour (organizational citizenship behaviour and deviant behaviour). Additionally, job frustration was found to mediate the relationship between leader procrastination and follower outcomes. The quality of the leader-follower relationship, as a boundary condition, was shown to mitigate the detrimental effects of leader procrastination. Together, the findings suggest that leader procrastination is a distinct form of negative leadership behaviour that represents an important source of follower job frustration. PRACTITIONER POINTS: Leader procrastination is different from laissez-faire and directive leadership and can be detrimental to followers.Job frustration mediates the relationship between leader procrastination and follower discretionary behaviour.Organizations should facilitate high-quality LMX relationships as a method for mitigating the negative effects of leader procrastination.

Metabolic and magnetic resonance imaging: complementary modalities for the preoperative assessment of lateral pelvic lymph nodes in rectal cancer.

BACKGROUND: The management of lateral pelvic lymph nodes for rectal cancer is a topical and controversial issue. The aim of this study was to assess the relationship between lateral pelvic lymph node features on magnetic resonance imaging (MRI) and positron emission tomography-computed tomography (PET-CT) with oncological outcomes in patients with rectal cancer. METHODS: A retrospective analysis of 284 patients with primary locally advanced rectal cancer treated with neoadjuvant therapy and surgical resection with curative intent between January 2003 and Dec 2018 was undertaken. From this study population, a select cohort of 77 patients with abnormal lateral pelvic lymph nodes on preoperative imaging had imaging re-analysed by radiologists blinded to clinical outcomes. Pre and post neoadjuvant therapy MRI and PET-CT lateral pelvic lymph node features were correlated with oncological outcomes. RESULTS: A lateral pelvic lymph node short axis size ≥5 mm on post neoadjuvant therapy MRI was a significant predictor of worse 3-year local recurrence free survival (HR 8.35, P = 0.001). Lateral pelvic lymph node avidity on post neoadjuvant therapy PET-CT was a significant predictor of worse 3-year distant recurrence free survival (HR 5.62, P = 0.001). No correlation of oncological outcomes with overall survival was identified. CONCLUSION: Lateral pelvic lymph node imaging features on post-neoadjuvant therapy MRI and PET-CT predicted those at risk of rectal cancer recurrence. Further studies are required to confirm these findings that suggest restaging MRI and PET-CT are complementary modalities for the preoperative assessment of lateral pelvic lymph nodes in rectal cancer.

Saline-polyethylene glycol blends preserve in vitro annulus fibrosus hydration and mechanics: An experimental and finite-element analysis.

Precise control of tissue water content is essential for ensuring accurate, repeatable, and physiologically relevant measurements of tissue mechanics and biochemical composition. While previous studies have found that saline and polyethylene glycol (PEG) blends were effective at controlling tendon and ligament hydration levels, this work has yet to be extended to the annulus fibrosus (AF). Thus, the first objective of this study was to determine and validate an optimal buffer solution for targeting and maintaining hydration levels of tissue-level AF specimens in vitro. This was accomplished by measuring the transient swelling behavior of bovine AF specimens in phosphate-buffered saline (PBS) and PEG buffers across a wide range of concentrations. Sub-failure, failure, and post-failure mechanics were measured to determine the relationship between changes in tissue hydration and tensile mechanical response. The effect of each buffer solution on tissue composition was also assessed. The second objective of this study was to assess the feasibility and effectiveness of using multi-phasic finite element models to investigate tissue swelling and mechanical responses in different external buffer solutions. A solution containing 6.25%w/v PBS and 6.25%w/v PEG effectively maintained tissue-level AF specimen hydration at fresh-frozen levels after 18 h in solution. Modulus, failure stress, failure strain, and post-failure toughness of specimens soaked in this solution for 18 h closely matched those of fresh-frozen specimens. In contrast, specimens soaked in 0.9%w/v PBS swelled over 100% after 18 h and exhibited significantly diminished sub-failure and failure properties compared to fresh-frozen controls. The increased cross-sectional area with swelling contributed to but was not sufficient to explain the diminished mechanics of PBS-soaked specimens, suggesting additional sub-tissue scale mechanisms. Computational simulations of these specimens generally agreed with experimental results, highlighting the feasibility and importance of including a fluid-phase description when models aim to provide accurate predictions of biological tissue responses. As numerous previous studies suggest that tissue hydration plays a central role in maintaining proper mechanical and biological function, robust methods for controlling hydration levels are essential as the field advances in probing the relationship between tissue hydration, aging, injury, and disease.

Non-enzymatic glycation of annulus fibrosus alters tissue-level failure mechanics in tension.

Advanced-glycation end products (AGEs) are known to accumulate in biological tissues with age and at an accelerated rate in patients with diabetes and chronic kidney disease. Clinically, diabetes has been linked to increased frequency and severity of back pain, accelerated disc degeneration, and an increased risk of disc herniation. Despite significant clinical evidence suggesting that diabetes-induced AGEs may play a role in intervertebral disc failure and substantial previous work investigating the effects of AGEs on bone, cartilage, and tendon mechanics, the effects of AGEs on annulus fibrosus (AF) failure mechanics have not yet been reported. Thus, the aim of this study was to determine the relationship between physiological levels of AGEs and AF tensile mechanics at two distinct loading rates. In vitro glycation treatments with methylglyoxal were applied to minimize changes in tissue hydration and induce two distinct levels of AGEs based on values measured from human AF tissues. In vitro glycation increased modulus by 48-99% and failure stress by 45-104% versus control and decreased post-failure energy absorption capacity by 15-32% versus control (ANOVA p < 0.0001 on means; range given across two loading rates and glycation levels). AGE content correlated strongly with modulus (R = 0.74, p < 0.0001) and failure stress (R = 0.70, p < 0.0001) and moderately with post-failure energy absorption capacity (R = 0.62, p < 0.0001). Failure strain was reduced by 10-17% at the high-glycation level (ANOVA p = 0.01). Tissue water content remained near or just above fresh-tissue levels for all groups. The alterations in mechanics with glycation reported here are consistent with trends from other connective tissues but do not fully explain the clinical predisposition of diabetics to disc herniation. The results from this study may be used in the development of advanced computational models that aim to study disc disease progression and to provide a deeper understanding of altered structure-function relationships that may lead to tissue dysfunction and failure with aging and disease.

Lobar Cerebral Microbleeds Are Associated With Cognitive Decline in Patients With Type 2 Diabetes Mellitus.

Purpose: Combined the number, volume, and location of cerebral microbleeds (CMBs), this study aimed to explore the different features of CMBs and their correlation with cognitive ability in patients with type 2 diabetes mellitus (T2DM). Methods: This study recruited 95 patients with T2DM and 80 healthy control (HC) individuals. AccuBrain®, an automated tool, was used to obtain the number and volume of CMBs. The scores on global cognition and five cognitive domains were derived from a battery of cognitive tests. The logistic regression and multivariate linear regression were conducted to determine the relationship between the CMBs (number, volume, and location) and cognitive ability in patients with T2DM. Results: After adjusting for several variables, the total volume of CMBs (OR = 0.332, 95%CI: 0.133-0.825, and p = 0.018) was independent risk factor for cognitive impairment, whereas the total number of CMBs was not (OR = 0933, 95%CI: 0.794-1.097, and p = 0.400). Furthermore, the volume of CMBs in lobar regions was independently associated with working memory (ß = -0.239, 95%CI: -0.565 to -0.035, and p = 0.027). However, no significant correlation between the number of CMBs (both lobar and deep/infratentorium) and any cognitive domains was observed. Conclusions: Lobar CMBs was related with cognitive impairment in patients with T2DM and might be a potential early warning signal. Compared with the counting analysis, the quantitative method offered a more sensitive and objective measurement for studying imaging features of CMBs.

Coronary image quality of 320-MDCT in patients with heart rates above 65 beats per minute: preliminary experience.

OBJECTIVE: High heart rate may negatively influence the image quality of cardiac CT. The technical advances of 320-MDCT may overcome issues with poor image quality associated with high heart rate. This study aimed to evaluate the coronary image quality of 320-MDCT in patients with heart rates above 65 beats/min. MATERIALS AND METHODS: Patients who presented for cardiac CT were divided into two groups according to heart rate, either greater than 65 beats/min or less than or equal to 65 beats/min. Two radiologists were blinded to the patient groups and evaluated images of 15 coronary artery segments per patient using 320-MDCT with consensus agreement. The image quality was scored subjectively as 1 or 2 (diagnostic quality) or 3 (poor quality and nondiagnostic). RESULTS: There were no statistically significant differences between the two groups in terms of age, sex, and body mass index (p > 0.05). The median heart rate was 70 beats/min (range, 67-110 beats/min) for the group with heart rate greater than 65 beats/min and 60 beats/min (range, 48-65 beats/min) for the group with heart rate less than or equal to 65 beats/min (p < 0.001). In patients with heart rates greater than 65 beats/min, diagnostic quality images (scores of 1 or 2) were obtained in 95.6% of the analyzed segments, compared with 96.9% in the group with heart rate less than or equal to 65 beats/min (p = 0.7). CONCLUSION: Our initial evaluation suggests that coronary artery images of diagnostic quality can be obtained using 320-MDCT in most patients with heart rates greater than 65 beats/min, in percentages similar to those for patients with heart rates less than or equal to 65 beats/min. This finding may be the result of the inherent image acquisition and reconstruction technique of 320-MDCT.

The Role of Change in the Relationships Between Leader-Member Exchange/Coworker Exchange and Newcomer Performance: A Latent Growth Modeling Approach.

This study examines whether and how the qualities of newcomers' interpersonal relationships [i.e., leader-member exchange (LMX) and coworker exchange (CWX)] relate to their initial performance and how changes in the qualities of these relationships relate to the changes in performance. To test a latent growth model, we collected data from 230 newcomers at six time points over a 6-week period. The results showed that LMX quality is positively related to initial newcomer performance; however, changes in LMX quality are not statistically significantly related to changes in newcomer performance. In contrast, an increase in CWX quality is positively related to newcomer performance improvement, but the initial quality of CWX does not predict newcomer performance. Furthermore, newcomers' psychological entitlement moderates the relationship between LMX quality and newcomer performance; newcomers' conscientiousness moderates the relationship between increases in CWX quality and improvements in newcomer performance. The findings increase our understanding of the newcomer exchange relationship-performance link over time and suggest that future newcomer socialization research explore the initial level of and the changes in these relationships simultaneously.

Do antispasmodics or rectal enemas improve image quality on multiparametric prostate MRI? An 'Evidence-Based Practice' review of the literature.

Multiparametric magnetic resonance imaging (mpMRI) of the prostate is increasingly used for the preoperative detection and staging of prostate cancer. Image quality of prostate mpMRI can be significantly degraded by motion related artefact due to bowel peristalsis and susceptibility related artefact, which reduces cancer detection sensitivity. The use of several different methods including anstispasmodic medications and rectal enemas were proposed as potential methods to reduce mpMRI artefacts, but current recommendations in the scientific literature are conflicting and inconsistent. This article seeks to identify the best available evidence to determine which patient preparation method is most effective in improving prostate mpMRI, and provides recommendations for further areas of research. We used the five-step 'Evidence-Based Practice' systematic approach of 'Ask, Search, Appraise, Apply and Evaluate' described by the McMaster University and National Health Service for critical appraisal of topics. We developed a focused clinical question using a PICO format, and performed a primary and secondary literature search through Ovid Medline, Ovid Embase and Cochrane CENTRAL (Wiley). All identified articles were appraised for strength and validity. Seven articles were retrieved which demonstrated conflicting sensitivities and specificities for intravenous hyoscine butylbromide and rectal enema in improving image susceptibility artefact, motion artefact, and anatomic distortion on the T2 or diffusion weighted imaging sequences. Intravenous hysoscine butylbromide is the optimum patient preparation method for improving T2W and DWI image quality in prostate mpMRI. The use of a preparatory rectal enema is not currently recommended, but better quality studies are required.

Subdural hemorrhage post obstetric epidural: An MRI Case Report.

Epidural and spinal anesthesia is a routine anesthetic procedure and considered the standard of care for intrapartum analgesia. Complications of epidurals vary greatly from temporary hypotension to meningitis and intracranial bleeds. Intracranial subdural hemorrhages are considered a rare but serious complication that may have significant long-term morbidity, particularly for postpartum women. The most common complication is a postdural puncture headache and patients with intracranial subdural hemorrhage present with similar symptoms.1 Imaging may be necessary to differentiate the 2 conditions and ensure patients are treated correctly.

Magnetic resonance imaging manifestations of cerebral small vessel disease: automated quantification and clinical application.

ABSTRACT: The common cerebral small vessel disease (CSVD) neuroimaging features visible on conventional structural magnetic resonance imaging include recent small subcortical infarcts, lacunes, white matter hyperintensities, perivascular spaces, microbleeds, and brain atrophy. The CSVD neuroimaging features have shared and distinct clinical consequences, and the automatic quantification methods for these features are increasingly used in research and clinical settings. This review article explores the recent progress in CSVD neuroimaging feature quantification and provides an overview of the clinical consequences of these CSVD features as well as the possibilities of using these features as endpoints in clinical trials. The added value of CSVD neuroimaging quantification is also discussed for researches focused on the mechanism of CSVD and the prognosis in subjects with CSVD.

Primary myelofibrosis: spectrum of imaging features and disease-related complications.

Primary myelofibrosis is a chronic clonal stem cell disorder that results in a build-up of marrow fibrosis and dysfunction, hypermetabolic states, and myeloid metaplasia. The clinical and radiological consequences can be quite diverse and range from the manifestations of osteosclerosis and extramedullary haematopoiesis to thrombohaemorrhagic complications from haemostatic dysfunction. In addition, there is the challenge of identifying less well-recognised sites of extramedullary haematopoiesis and their site-specific complications. The intent of this article is to illustrate the spectrum of primary myelofibrosis as declared though multimodality imaging, with examples of both common and rarer disease manifestations.

MRI for pelvic floor dysfunction: can the strain phase be eliminated?

PURPOSE: The purpose of the study was to determine if the strain phase of an MR defecography (MRD) protocol is redundant and can be eliminated without a loss of diagnostic information. MATERIALS AND METHODS: Institutional review board approval was obtained and the requirement for informed consent was waived. A retrospective single-center review of 80 MRD examinations (68 female, 12 male, mean age 55 years old) was conducted. Two radiologists blinded to patient information evaluated in consensus the strain and evacuation phases separately and in a random order. Each phase was assessed for the presence and degree of posterior compartment descent, cystocele, urethral hypermobility, uterovaginal prolapse, rectocele, rectal intussusception, and enterocele. The degree of pelvic floor descent was compared using a paired t test and McNemar's test was used to compare the proportion of abnormal findings. RESULTS: The evacuation phase identified all abnormalities identified on the strain phase and also identified both additional and more pronounced abnormalities, including an additional 34 cystoceles, 20 cases of urethral hypermobility, 13 uterovaginal prolapses, 36 rectoceles, 5 rectal intussusceptions, and 6 enteroceles (all p < 0.02). The mean posterior compartment descent was 24.1 mm greater on the evacuation phase than the strain phase (p < 0.0001). CONCLUSION: The strain phase is redundant and we propose that it can be eliminated from a routine MRD protocol. This will help streamline the examination, simplify patient instructions, and reduce both imaging and reporting time.

Upregulated MT1-MMP/TIMP-2 axis in the TSU-Pr1-B1/B2 model of metastatic progression in transitional cell carcinoma of the bladder.

Muscle invasive transitional cell carcinoma (TCC) of the bladder is associated with a high frequency of metastasis, resulting in poor prognosis for patients presenting with this disease. Models that capture and demonstrate step-wise enhancement of elements of the human metastatic cascade on a similar genetic background are useful research tools. We have utilized the transitional cell carcinoma cell line TSU-Pr1 to develop an in vivo experimental model of bladder TCC metastasis. TSU-Pr1 cells were inoculated into the left cardiac ventricle of SCID mice and the development of bone metastases was monitored using high resolution X-ray. Tumor tissue from a single bone lesion was excised and cultured in vitro to generate the TSU-Pr1-B1 subline. This cycle was repeated with the TSU-Pr1-B1 cells to generate the successive subline TSU-Pr1-B2. DNA profiling and karyotype analysis confirmed the genetic relationship of these three cell lines. In vitro, the growth rate of these cell lines was not significantly different. However, following intracardiac inoculation TSU-Pr1, TSU-Pr1-B1 and TSU-Pr1-B2 exhibited increasing metastatic potential with a concomitant decrease in time to the onset of radiologically detectable metastatic bone lesions. Significant elevations in the levels of mRNA expression of the matrix metalloproteases (MMPs) membrane type 1-MMP (MT1-MMP), MT2-MMP and MMP-9, and their inhibitor, tissue inhibitor of metalloprotease-2 (TIMP-2), across the progressively metastatic cell lines, were detected by quantitative PCR. Given the role of MT1-MMP and TIMP-2 in MMP-2 activation, and the upregulation of MMP-9, these data suggest an important role for matrix remodeling, particularly basement membrane, in this progression. The TSU-Pr1-B1/B2 model holds promise for further identification of important molecules.

Mitigation of cerebellar neuropathy in globoid cell leukodystrophy mice by AAV-mediated gene therapy.

Globoid cell leukodystrophy (GLD) is an autosomal recessive, lysosomal storage disease caused by deficiency of the enzyme galactocerebrosidase (GALC). The absence of GALC activity leads to the accumulation of the toxic substance psychosine and the preferential loss of myelinating cells in the central and peripheral nervous systems. Profound demyelination, astrogliosis and axonopathy are the hallmarks of the pathogenesis of GLD, and cerebellar ataxia is one of the dominant manifestations in adolescents and adults affected with GLD. To date, studies regarding cerebellar degeneration in GLD are limited. In this study, the efficacy of cerebellum-targeted gene therapy on the cerebellar neuropathology in twitcher mice (a murine model of GLD) has been validated. We observed degeneration of Purkinje cells, Bergmann glia, and granule cells in addition to astrocytosis and demyelination in the cerebellum of the twitcher mice. Ultrastructural analysis revealed dark cell degeneration and disintegration of the cellular composition of Purkinje cells in untreated twitcher mice. In addition, the expressions of neurotrophic factors CNTF, GDNF and IGF-I were up-regulated and the expression of BDNF was down-regulated. Intracerebellar-mediated gene therapy efficiently corrected enzymatic deficiency by direct transduction to Purkinje cells and cross-correction in other cell types in the cerebellum, leading to the amelioration of both neuroinflammation and demyelination. The population, dendritic territory, and axonal processes of Purkinje cells remained normal in the cerebellum of treated twitcher mice, where radial fibers of Bergmann glia spanned the molecular layer and collateral branches ensheathed the dendritic processes of Purkinje cells. Moreover, the aberrant expressions of neurotrophic factors were mitigated in the cerebellum of treated twitcher mice, indicating the preservation of cellular function in addition to maintaining the neuronal architecture. The life span of the treated twitcher mice was significantly prolonged and their neurobehavioral performance was improved. Taken together, our findings underscore the complexity of cerebellar neurodegeneration in GLD and highlight the potential effectiveness of gene therapy in mitigating neuropathological deficits in GLD and other neurodegenerative disorders in which Purkinje cells are involved.

An endless line on the chest radiograph.

A 40-year-old male patient had his right femoral vein catheterised following admission with altered conscious state from polypharmacy overdose. The procedure was documented as successful and uncomplicated. A postprocedural chest radiograph demonstrated a linear metallic opacity projecting over the superior vena cava and inferior vena cava (SVC and IVC, respectively), with superior and inferior ends not visualised. This did not alert the attending radiologist and intensivist who might have assumed such a metallic object to be external to the patient. Only the central line was removed prior to patient discharge 2 days later. The patient died 2 years later from unrelated streptococcal pneumonia complicated by septicaemia and multiorgan failure. The postmortem discovered a central venous guidewire in the IVC across the right atrium into SVC.

Comparison of 3MP medical-grade to 1MP office-grade LCD monitors in mammographic diagnostic and perceptual performance.

INTRODUCTION: Picture archiving and communication systems images designed to be viewed on high-resolution medical-grade monitors are routinely viewed on office-grade monitors on the wards or at home. This study aimed to determine whether a statistically significant difference in diagnostic (cancer detection) and perceptual (microcalcification detection) performance exists between 3MP grade and 1MP office-grade monitors. METHODS: 3MP Dome medical-grade liquid crystal display (LCD) monitors (Planar, Beaverton, OR, USA) were compared to 1MP Dell office-grade LCD monitors (Dell Inc, Round Rock, TX, USA). Eight radiologists (reader experience 8-30 years) read the same set of 100 mammograms (23/100 with proven cancers and 52/100 with microcalcifications) presented in random order on three occasions separated by two time intervals of 12 weeks. Reads 1 and 3 utilised 3MP monitors and formed the baseline read. Read 2 utilised 1MP monitors and constituted the experimental read. Reading conditions were standardised. Readers were aware of which monitors they were using. Multivariate logistic regression analysis (to account for reader variability and monitor impact) was performed to assess for statistical significance. RESULTS: At α = 5%, confidence intervals analysis comparing the measured parameters between 1MP to 3MP monitors demonstrated no statistically significant difference in diagnostic and perceptual performance for the reader group. In cancer detection (the diagnostic task), reader accuracy remained high irrespective of monitor type. Regression analysis comparing performance with 1MP against 3MP monitors found P values of 0.693 and 0.324 for diagnostic and perceptual performance, respectively. CONCLUSION: There were no statistically and clinically significant differences between 3MP and 1MP monitors in mammographic diagnostic and perceptual performance. Comparable performance may be due to compensatory behaviour by readers.

Thioflavin T fluorescence in human serum: correlations with vascular health and cardiovascular risk factors.

OBJECTIVES: Amyloid fibrils and amyloid-like structures are implicated in atherosclerosis via macrophage activation and inflammation. A common property of amyloid-like structures is their ability to induce thioflavin T (ThT) fluorescence. We measured ThT fluorescence in serum and related these levels to traditional cardiovascular risk factors and non-invasive measures of vascular dysfunction (elasticity). In addition, chemically modified serum components that contribute to serum ThT fluorescence were explored and identified. DESIGN, METHODS, AND RESULTS: Sera from 105 people, including 35 healthy subjects, and 70 high cardiovascular risk patients (36 with rheumatoid arthritis and 34 with systemic lupus erythrematosus) showed an 8.75-fold variation in induced ThT fluorescence. Although mean (+/-SD) ThT fluorescence did not differ significantly between groups (controls 0.97+/-0.26, RA 1.12+/-0.45, and SLE 0.74+/-0.23), the combined data set showed significant inverse correlation (p=0.046) between ThT fluorescence tertiles and small artery elasticity. Correlation was also found between ThT fluorescence tertiles and LDL-cholesterol, total-cholesterol, and C-reactive protein. Floatation fractionation of apoB containing lipoproteins showed that ThT reactivity in this fraction correlated with both serum oxidised-LDL and LDL-cholesterol levels. However, approximately 94% of ThT reactivity in serum was associated with the non-apoB containing serum fraction, with the majority of ThT fluorescence associated with albumin. Incubation of purified albumin with glucose or with methylglyoxal induced ThT fluorescence, suggesting that glycated or chemical adducts of albumin contribute to the variation in ThT fluorescence of human serum. CONCLUSIONS: We propose that the detection of these adducts in serum using ThT fluorescence measurements may provide a marker for chemically modified protein structures that could assist the assessment of cardiovascular disease risk.