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Tissue decellularization has rapidly developed to be a practical approach in tissue engineering research; biological tissue is cleared of cells resulting in a protein-rich husk as a natural scaffold for growing transplanted cells as a donor organ therapy. Minimally processed, acellular extracellular matrix reproduces natural interactions with cells in vitro and for tissue engineering applications in animal models. There are many decellularization techniques that achieve preservation of molecular profile (proteins and sugars), microstructure features such as organization of ECM layers (interstitial matrix and basement membrane) and organ level macrofeatures (vasculature and tissue compartments). While structural and molecular cues receive attention, mechanical and material properties of decellularized tissues are not often discussed. The effects of decellularization on an organ depend on the tissue properties, clearing mechanism, chemical interactions, solubility, temperature, and treatment duration. Physical characterization by a few labs including work from the authors provides evidence that decellularization protocols should be tailored to specific research questions. Physical characterization beyond histology and immunohistochemistry of the decellularized matrix (dECM) extends evaluation of retained functional features of the original tissue. We direct our attention to current technologies that can be employed for structure function analysis of dECM using underutilized tools such as atomic force microscopy (AFM), cryogenic electron microscopy (cryo-EM), dynamic mechanical analysis (DMA), Fourier-transform infrared spectroscopy (FTIR), mass spectrometry, and rheometry. Structural imaging and mechanical functional testing combined with high-throughput molecular analyses opens a new approach for a deeper appreciation of how cellular behavior is influenced by the isolated microenvironment (specifically dECM). Additionally, the impact of these features with different decellularization techniques and generation of synthetic material scaffolds with desired attributes are informed. Ultimately, this mechanical profiling provides a new dimension to our understanding of decellularized matrix and its role in new applications., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this article., (Copyright © 2021 Ryan A. Behmer Hansen et al.)

Aims: We assessed the accuracy of 64-slice multidetector computed tomography (MDCT) compared with that of invasive coronary angiography (ICA) in the evaluation of symptomatic postcoronary artery bypass graft (post-CABG) patients., Methods: MDCT and ICA were performed in 44 consecutive post-CABG patients with chest pain (mean age 66 +/- 10 years, mean duration post-CABG 9 +/- 5 years). MDCT findings were compared with the corresponding ICA, which was read by an interventional cardiologist blinded to the MDCT findings. Significant stenosis was defined as at least 50% luminal stenosis., Results: One hundred and thirty-seven grafts (31 arterial and 106 venous), all evaluable by MDCT, were assessed. In a 'per graft' analysis, MDCT could detect significant disease in bypass grafts (graft occlusion or stenosis) with a sensitivity of 98% and specificity of 98%. In a 'per segment' analysis, MDCT could detect significant disease in all native coronary arteries with a sensitivity of 91% and specificity of 79% and in clinically relevant native coronary arteries with a sensitivity of 92% and specificity of 84%. In a 'per vessel' analysis, MDCT could differentiate native arterial occlusion from nonocclusive stenosis with a sensitivity of 68% and specificity of 70%. In a 'per patient' analysis, MDCT could detect significant disease in bypass grafts or clinically relevant native coronary arteries with a sensitivity of 100%, specificity of 40% and accuracy of 93%., Conclusion: Sixty-four-slice MDCT allows evaluation of bypass grafts and native coronary arteries in post-CABG patients. Although accurate for detecting bypass graft disease, 64-slice MDCT has significant limitations when evaluating native arteries in post-CABG patients.

The purpose of our study was to determine the prevalence of non-cardiac findings in a large series of patients undergoing contrast-enhanced cardiac multi-detector computed tomography (MDCT) scans. Non-cardiac findings were classified according to the organ of involvement and level of significance. We retrospectively reviewed scans and reports of 1,061 patients performed between 1 April 2004 and 31 April 2006. Non-cardiac findings were considered significant if they warranted further radiological or clinical follow-up. A total of 103 non-cardiac findings were reported in 85 (8.0%) of the 1,061 patients. Of these lesions, 48 (46.7%) were significant and 55 (53.3%) were not. The significant lesions were found in 33 of the 1,061 patients (3.1%). Among the significant abnormalities, the three most common were pulmonary nodules (16.7%), emphysema (16.7%) and possible hepatic carcinomas (12.6%). Patients with non-cardiac findings were significantly older than those without (mean age 60 +/- 6 years vs. 55 +/- 8 years; P < 0.0001). The prevalence of active smoking was significantly higher in patients with non-cardiac findings (28.2 vs. 17.8%; P = 0.03). The prevalence of non-cardiac abnormalities detected by cardiac MDCT was 8% and about half of these findings were deemed significant. These lesions commonly occurred in the lungs and the liver. Age and active smoking were predictive of the presence of non-cardiac abnormalities.

Erdheim-Chester disease is a non-Langerhans cell histiocytosis that is progressive and may lead on to multi-organ involvement. Pulmonary involvement is rare, its presentation is nonspecific, and it carries an adverse outcome. Several radiological features, when considered together, may point to the diagnosis. This condition should be considered in the differential diagnosis of interstitial lung disease. We describe a 39-year-old woman who presented with dry cough, malaise and progressive dyspnoea. She was diagnosed to have late stage interstitial lung disease due to Erdheim-Chester disease.

Background: Little is known about the long-term consequence of severe acute respiratory syndrome (SARS). We carried out an assessment on SARS patients after their recovery from their acute illness., Method: Postal survey comprising Health-Related Quality of Life (HRQoL) questionnaires and anxiety and depression measures was sent to them at 3 months' postdischarge., Results: There was a significant impairment in both the HRQoL and mental functioning. Forty-one percent had scores indicative of a posttraumatic stress disorder (PTSD); about 30% had likely anxiety and depression., Conclusion: SARS has significant impact on HRQoL and psychological status at 3 months.

Study Objectives: To characterize the long-term pulmonary function and health status in a prospectively identified cohort of patients who survived the severe acute respiratory syndrome (SARS)., Design: Prospective follow-up cohort study., Setting: University-affiliated hospital., Patients: Ninety-four patients who recovered from SARS were assessed at a uniform time point of 1 year after hospital discharge., Measurements: The study included the measurement of static and dynamic lung volumes, the determination of the diffusing capacity of the lung for carbon monoxide (D(LCO)), and a health status evaluation using the St. George Respiratory Questionnaire (SGRQ)., Results: Eleven patients (12%) had mild impairment of FVC, 20 (21%) had mild impairment of FEV1, 5 (5%) had mild impairment of the FEV1/FVC ratio, and 17 (18%) had mild impairment of the D(LCO). There was one patient (1%) who had moderate impairment of FVC, one patient (1%) who had moderate impairment of the FEV1/FVC ratio, and three patients (3%) who had moderate impairment of the D(LCO). No pulmonary function abnormalities were detected in 59 patients (63%). Mean scores were significantly higher (ie, worse) than the population norms in the activity (p < 0.001), impacts (p < 0.001), and total (p < 0.001) domains of the SGRQ., Conclusions: One year after recovery from SARS, persistent pulmonary function impairment was found in about one third of patients. The health status of SARS survivors was also significantly worse compared with the healthy population. The main determinants of morbidity in recovered SARS patients need to be further defined.

Background: Obtaining meaningful temperature for the human body requires identifying a body site that will provide reliable data across a large population. It is important to understand that skin temperature does not solely depend on body-core temperature and may be affected by other physiological and environmental factors. Currently, there is lack of empirical data in correlating facial surface temperature with body core temperature. Present IR systems in use at airports/immigration checkpoints have not been scientifically validated particularly in regards to the false-negative rate. As a result, they may create a false sense of security by underestimating the number of febrile (and possibly infected) individuals. This article evaluates the effectiveness of thermal scanner when it is being used for mass blind screening of potential fever subjects such as SARS or bird flu patients., Methods: Bio-statistics with regression analysis and ROC is applied to analyse the data collected (502) from the SARS hospital in Singapore and conclusive results are drawn from them. The results are vital in determining two very important pieces of information: the best and yet practical region on the face to take readings and optimal pre-set threshold temperature for the thermal imager., Results: (1) The thermal scanner can be used as a first line tool for the mass blind screening of hyperthermia, (2) the readings from the scanner suggest good correlation with the ear temperature readings, (3) an imager temperature threshold should be determined by the environmental factors, outdoor condition in particular, the physiological site offset and the performance characteristics of thermal imager to warrant the most accurate and reliable screening operation., Conclusions: The analysis suggested that the thermal imager used holds much promise for mass blind screening when the readings from a specific region have a good correlation with the ear temperature. From the regression analysis, the best reading is taken from the maximum temperature in the eye region, followed by the maximum temperature in the forehead region. With ROC analysis, a randomly selected individual from the fever group has a test value larger than that for a randomly selected individual from the normal group in 97.2% of the time. The test can distinguish between the normal and febrile groups and an optimum threshold temperature for the thermal imager can be found. The pre-set threshold cut-off temperature for the current thermal imager was found to be 36.3 degrees C with reference to the associated environmental condition. Any temperature readings that exceed this reading will trigger off the alarm and a thermometer will be used to verify the whether the person is having fever.

The aim of this study was to investigate pulmonary function and exercise capacity in a group of survivors of the severe acute respiratory syndrome (SARS). At 3 months after hospital discharge, 46 survivors of SARS underwent the following evaluation: spirometry, static lung volumes and carbon monoxide transfer factor (TL,CO). In total, 44 of these patients underwent cardiopulmonary exercise testing. No abnormalities were detected in the pulmonary function tests in 23 (50%) of the patients. Abnormalities of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC and TL,CO were detected in seven (15%), 12 (26%), one (2%) and 18 (39%) patients, respectively. All of these abnormalities were mild except in one case. In 18 patients (41%), the maximum aerobic capacity was below the lower limit of the normal range. Breathing reserve was low in four patients and significant oxygen desaturation was detected in a further four patients. Comparison of the measured exercise capacity with resting pulmonary function tests showed many cases of discordance in impairment. In conclusion, pulmonary function defects were detected in half of the recovered severe acute respiratory syndrome patients 3 months after hospital discharge, but the impairment was mild in almost all cases. Many patients had reduced exercise capacity that cannot be accounted for by impairment of pulmonary function.

A new form of atypical pneumonia was reported in the East Asian region beginning from early 2003. This was later termed by the World Health Organisation as Severe Acute Respiratory Syndrome (SARS). The diagnosis of SARS relies on a combination of clinical features and chest radiographic findings. A preliminary review of SARS in Singapore shows chest radiographic findings of patchy airspace shadowing with severe cases progressing to diffuse air-space shadowing. We illustrate these findings with temporal correlation in our case report. As SARS is a contagious, rapidly progressive and potentially fatal condition, early diagnosis is crucial for prompt management and isolation of patients. Recognition of chest radiographic findings aids in the early diagnosis and containment of SARS.

Nonspecific interstitial pneumonia (NSIP) has been recently described as a distinct clinicopathologic entity. We describe an unusual case of a middle-aged man who presented with exertional dyspnoea, cough, radiographic airspace opacities in the left lung and previous history of right thoracotomy for suspected right lower lobe neoplasm. Histology at that time revealed "chronic inflammation". A course of high-dose steroids was given after failure of the airspace opacities to respond to a trial of antituberculous therapy. Improvement in symptoms and radiological appearance was noted subsequently. A diagnosis of nonspecific interstitial pneumonia was made on review of the initial open lung biopsy specimen. Seven months after tailing down to maintenance low-dose steroids, the NSIP relapsed. The NSIP subsequently responded again to high-dose steroids. This case illustrates that NSIP is a difficult diagnosis, may present as a focal lung opacity initially, and may relapse after steroid dose is tailed down.

The ability of Staphylococcus aureus cells to induce platelet aggregation has long been recognized. However, despite several attempts to identify the mechanisms involved in this interaction, the nature of the bacterial receptors required remains poorly understood. Using genetic manipulation, this study for the first time provides clear evidence that several S. aureus surface proteins participate in the inter-action with platelets. Mutants of S. aureus strain Newman lacking one or more surface proteins were tested for their ability to stimulate platelet aggregation. This approach was complemented by the expression of a number of candidate proteins in the non-aggregating Gram-positive bacterium Lacto-coccus lactis. S. aureus-induced aggregation was monophasic and was dependent on the platelet receptor GPIIb/IIIa. The fibrinogen-binding proteins, clumping factors A and B and the serine-aspartate repeat protein SdrE could each induce aggregation when expressed in L. lactis. Although protein A expressed in L. lactis was not capable of inducing aggregation independently, it enhanced the aggregation response when expressed on the surface of S. aureus. Thus, S. aureus has multiple mechanisms for stimulating platelet aggregation. Such functional redundancy suggests that this phenomenon may be important in the pathogenesis of invasive diseases such as infective endocarditis.

A 36-year-old Korean man presented with a history of epilepsy. MR imaging of the brain revealed multiple conglomerated round nodules that were hypointense on both T1-and-T2 weighted images. These were located at the left temporal and occipital lobes and had surrounding encephalomalacia. CT scan confirmed the presence of large calcified nodules in the corresponding regions. These imaging findings were typical of chronic cerebral paragonimiasis. The clinical, CT and MR features of cerebral paragonimiasis are reviewed.

A prospective study of 211 central venous catheters consecutively placed in 186 patients under radiological guidance was conducted over an 18-month period. The majority (64%) of our patients were at risk for acute complications or failure. These risks included bleeding tendency, distorted anatomy, or previous complicated lines and failed "blind" percutaneous attempts. We employed the subtraction angiographic technique for venous mapping or ultrasound localisation to guide our initial puncture. The accumulated catheter experience was 15,295 days and the median catheter survival time was 166 days. The success rate was 100%. Our acute complications included 1 case of arterial puncture (0.5%), 2 pneumothoraces (1.0%), and 13 patients (6.1%) with haematoma or prolonged oozing at the puncture site. The calculated infection rate was 0.25 episodes per 100 catheter days at risk. These results are comparable to those reported in the literature. We conclude that central venous catheterisation using imaging guidance is accurate and safe, and should be the method of choice especially in high-risk patients.