Silver trauma: a study of pre- and post-COVID-19 pandemic pan-CT scanning in elderly trauma patients in a large teaching hospital.

AIM: The challenges posed by the assessment of elderly trauma patients increase the reliance on emergency CT scanning to diagnose an injury. The COVID-19 pandemic posed challenges to image service delivery. We sought to assess the effect of the COVID-19 pandemic on the imaging of elderly trauma. MATERIALS AND METHODS: All trauma patients aged 65 and over who underwent whole-body CT scanning in the same 3-month period (April-June) in 2019 and 2022 were included in our study. Data was collected on demographics, time of scanning, clinical request details and positive report findings. Anatomical injury distribution, abbreviated injury scale (AIS) and injury severity scores (ISS) were calculated. Consensus judgment was obtained on scan justification and significance of findings. Chi-squared test of association was applied to the categorical outcomes of interest. Associations were considered significant if p<0.05. RESULTS: 79 patients were scanned in the pre-pandemic assessment period versus 217 post-pandemic, an increase of 175%, including a 248% rise in fall-from-standing requests. There was a statistically significant reduction of trauma CT requests meeting fulfilment criteria post-pandemic (95% vs 83%) (p=0.008), with significantly fewer positive findings (45.6% vs 29%) (p=0.024). There was a decrease in median ISS score in the post-pandemic group (p=0.062). CONCLUSION: Despite increased scanning, there was a reduction in both the number and severity of positive traumatic imaging findings. The pandemic has increased reliance on CT without a concomitant increase in the detection of positive findings nor clinically significant findings. This single-centre study demonstrates the need to further evaluate pan-CT trauma scanning in silver trauma patients.

A retrospective audit of the timescales involved in the diagnosis and management of suspected Achilles tendon ruptures at a single National Health Service trust: A quality service improvement and redesign project.

Introduction: The Achilles tendon is the most frequently ruptured tendon. Prompt diagnosis of this injury ensures optimal management decisions are instituted early ensuring the best outcome and patient experience, at minimal cost to the United Kingdom National Health Service. Despite this, regional and national variations to diagnosis and management exist, with anecdotal evidence of inefficiencies in the local patient pathway. To explore this further, a retrospective departmental audit of timescales from presentation to ultrasound diagnosis and definitive treatment decision was undertaken. Methods: All suspected Achilles tendon ruptures in 2018 were identified through electronic and written patient records, and information on timescales involved in the diagnosis and management of each compiled. Descriptive statistics were used to map each step of the pathway and timescales involved, with performance assessed against local departmental standards and the Swansea Morriston Achilles Rupture Treatment (SMART) protocol. Results: In total, 119 patients were identified, of which 113 received an ultrasound examination. Local departmental standards were met in the majority of cases, with 78% (n = 88) diagnosed by ultrasound within one week of the request and 83% (n = 91) given a treatment decision within two weeks of presentation. However, this was suboptimal when compared with timeframes utilised for developing the SMART protocol, with only 7% (n = 8) scanned within 48 hours of presentation. Conclusions: Key areas of the patient pathway were identified for quality service improvement and redesign, with multidisciplinary discussion resulting in the development of a revised patient pathway which expedites diagnosis and treatment for these injuries.

Multi-ENPS simulator support tool with automatic file inter-conversion and multi-membrane execution.

P System or Membrane Computing is an unconventional and natural computing model inspired by the functioning of a living cell. This model has an inherently parallel structure. There are several variants of P System developed, each of which has a different application. One of the variants, Enzymatic Numerical P System (ENPS), has primarily been developed to be used with numerical values (as in economics) and thus has vast applications. For realizing ENPS there are several tools available, primarily based on Java and Python, each of which has a different input format. Currently, there is no tool which allows the user to execute ENPS using both the simulators on the same platform, the issue being inter-conversion between input formats, namely, XML and PeP (specific format designed for Python based ENPS). Another major issue with existing simulators is their inability to allow multiple membrane systems to be executed and there is no facility for interconnection between two membrane systems. A tool developed here solves both problems namely, file inter-conversion and multiple membrane support by transferring dependent variable values automatically according to users' choice. The tool is developed using Python 3.0 and has only a few dependencies. The tool is tested under different scenarios and the results confirm the correctness of the tool.

GPUPeP: Parallel Enzymatic Numerical P System simulator with a Python-based interface.

Membrane computing is a computational paradigm inspired by the structure and behavior of a living cell. P Systems are the computing devices that are used to realize membrane computing models. Numerous theoretical studies on many variants of P Systems have shown them to be computationally universal. There is a wide range of applications of P Systems from modeling of biological processes to image processing. Among many variants of P Systems, one of the most important is Enzymatic Numerical P System (ENPS). ENPS is a class of P System in which membranes operate on numerical values. To realize the power of ENPS there are a few simulators developed. Each and every simulator has some advantages as well as some disadvantages. Here, a GPU based simulator using Python as a user interaction language is developed. This tool is a completely parallel variant, compatible with a Python based sequential simulator (PeP) which was the first Python based work for ENPS. The developed simulator uses CUDA to interact with GPU and gives the desired speed up, while processing the membranes. There are two important case studies which show the performance of the developed tool to be far better than the other serial simulators.

Cardiac allograft remodeling after heart transplantation is associated with increased graft vasculopathy and mortality.

The aim of this study was to assess the patterns, predictors and outcomes of left ventricular remodeling after heart transplantation (HTX). Routine echocardiographic studies were performed and analyzed at 1 week, 1 year and 3-5 years after HTX in 134 recipients. At each study point the total cohort was divided into three subgroups based on determination of left ventricle mass and relative wall thickness: (1) NG-normal geometry (2) CR-concentric remodeling and (3) CH-concentric hypertrophy. Abnormal left ventricular geometry was found as early as 1 week after HTX in 85% of patients. Explosive mode of donor brain death was the most significant determinant of CH (OR 2.9, p = 0.01) at 1 week. CH at 1 week (OR 2.72, p = 0.01), increased body mass index (OR 1.1, p = 0.01) and cytomegalovirus viremia (OR - 4.06, p = 0.02) were predictors of CH at 1 year. CH of the cardiac allograft at 1 year was associated with increased mortality as compared to NG (RR 1.87, p = 0.03). CR (RR 1.73, p = 0.027) and CH (RR 2.04, p = 0.008) of the cardiac allograft at 1 year is associated with increased subsequent graft arteriosclerosis as compared to NG.

Periprocedural anticoagulation for atrial fibrillation ablation.

BACKGROUND: Catheter ablation for atrial fibrillation (AF) can increase risk of left atrial (LA) thrombi and stroke. Optimal periprocedural anticoagulation has not been determined. OBJECTIVE: We report the role of administering warfarin and aspirin without low molecular weight heparin in patients undergoing AF ablation. METHODS: A total of 207 patients underwent ablation for AF. Transesophageal echocardiography (TEE) guided transseptal puncture and ruled out clot in the LA. After first puncture, the sheath was flushed with heparin (5,000 Units/mL). After second puncture, a bolus of 80 units/kg of heparin was given, followed by an infusion to maintain activated clotting time (ACT) around 300-350 seconds. Warfarin was stopped and aspirin was started (325 mg/day) 3 days preprocedure. Warfarin was restarted on the day of the procedure. Both medications were continued for 6 weeks postablation. Warfarin was continued for 6 months in patients with prior history of persistent or recurrent AF. Thirty-seven patients who showed smoke in the LA on TEE were given low molecular weight heparin postprocedure until international normalized ratio (INR) was therapeutic. RESULTS: Thirty-two patients had persistent and 175 had paroxysmal AF; 87 were cardioverted during ablation. Two patients had transient ischemic attack (TIA) on the sixth and eighth days, respectively, following ablation, with complete recovery. Both had subtherapeutic INRs. CONCLUSION: In patients without demonstrable clot or smoke in the LA, starting aspirin 3 days prior and warfarin immediately post-radiofrequency ablation, without low molecular weight heparin, with meticulous anticoagulation during the procedure, appears to be a safe mode of anticoagulation.

Quantitation of a 55K cellular protein: similar amount and instability in normal and malignant mouse cells.

Quantitative expression of a specific 55,000 (55K)-molecular-weight cellular protein was studied in two groups of mouse embryo fibroblast (clonal) cells originating from two parent clones, one of which possessed high tumorigenicity and the other of which possessed very low tumorigenicity. From the clone with low tumorigenicity, tumor lines and clones were obtained by selecting rare spontaneously transformed highly tumorigenic (mutant) cells. Cells were labeled during exponential growth for 3 h at 37 degrees C, with [35S]methionine, and the cellular 55K protein was immunoprecipitated with a monoclonal antibody and quantitated. There were low and approximately equal amounts of 55K protein in cells (clones) with both low and high tumorigenicity from both groups of cells, and there was no correlation at all between quantitative expression of 55K protein and of cellular tumorigenicity. There was approximately 10- to 20-fold more 55K protein in all simian virus 40-transformed T antigen-positive derivative clones, as shown previously. The T antigen-negative revertant tumor lines and clones obtained by an immunological in vivo selection method had low amounts of 55K protein, similar to the parent cell before simian virus 40 transformation. In all of the T antigen-negative cells, including the highly tumorigenic cells, degradation (turnover?) of the 55K protein was rapid, and a half-life of 15 to 60 min was estimated from pulse-chase experiments. In all of the T antigen-positive cells the 55K protein was stable (half-life greater than 10 h). In primary cells established from the tumors induced by highly tumorigenic cells there was a very low or no detectable amount of the 55K protein. This is in contrast to the primary cells obtained from early murine embryos in which we have reported high amounts of (stable) 55K proteins.

Clinical presentation, investigation, and management of pulmonary vein stenosis complicating ablation for atrial fibrillation.

BACKGROUND: Although segmental or circumferential ablation is effective in eliminating pulmonary vein (PV)-mediated atrial fibrillation (AF), this procedure may be complicated by the occurrence of PV stenosis. METHODS AND RESULTS: To establish the clinical presentation, diagnostic manifestations, and interventional management of PV stenosis, 23 patients with stenosis of 34 veins complicating ablation of AF were evaluated. Each patient became symptomatic 103+/-100 days after undergoing ablation. In 8 veins, the ablation producing the PV stenosis was a repeated procedure for continued AF. Nineteen patients presented with dyspnea on exertion, 7 with dyspnea at rest, 9 with cough, and 6 with chest pain. On multirow spiral computed tomography examination, the narrowest lumen of the affected PVs measured 3+/-2 mm compared with 13+/-3 mm at baseline (P< or =0.001). The relative perfusion of affected lung segments on isotope scans was reduced to 4+/-3% of total perfusion compared with 22+/-10% in unaffected segments. At percutaneous intervention, these veins showed 80+/-13% stenosis, with a mean gradient of 12+/-5 mm Hg. This was significantly reduced to a residual stenosis of 9+/-8% (P< or =0.001) and a residual gradient of 3+/-4 mm Hg (P< or =0.001). Twenty veins were treated with balloon dilatation alone, whereas 14 veins were stented with standard 10-mm-diameter bare-metal stents. Although the symptomatic response was nearly immediate and impressive, 14 patients developed in-stent or in-segment restenosis, requiring repeated interventions in 13. CONCLUSIONS: Percutaneous intervention produces rapid and dramatic symptom relief in patients with highly symptomatic PV stenosis after radiofrequency ablation for AF. Nevertheless, alternative treatment methods will be required to decrease recurrent in-stent or in-segment restenosis.

Disease mapping using mixture distribution.

BACKGROUND & OBJECTIVES: Data on infectious diseases like tuberculosis (TB) have been analyzed in the past without giving adequate attention to spatial variations. Earlier studies also attempted to display disease status of sub regions, usually census tracts, by categorizing them into quartiles, that helps the authorities to identify high- or low-risk areas. This approach is based mainly on binomial and Poisson models for disease data, and the recent attempts focus on using mixture models of Poisson distribution. We carried out this study to find wards of Madurai Corporation having high risks for TB disease, to develop a model of mixture of Poisson distributions for the number of cases and to classify each ward to one of many risk groups for TB disease, and to represent spatial distribution of TB incidence in Madurai city. METHODS: produced the observed counts of TB patients in 72 wards of Madurai Corporation. The number of risk groups and the Poisson parameters of each group were found by maximum likelihood approach using the computer package C.A.MAN (Computer Assisted Mixture ANalysis). Bayesian methods were used to associate each ward to a particular risk group. The results were geographically presented in maps by using ArcView mapping software. RESULTS: Using binomial model, 26 wards were categorized as high risk wards, and with mixture model approach 15 wards showed standardized morbility ratio (SMR) >1. The wards along river Vaigai and densely populated wards had high risk. INTERPRETATION & CONCLUSION: Our findings demonstrate the usefulness of the mixture models for disease data with geographical variations.

Characterization of reentrant circuit in macroreentrant right atrial tachycardia after surgical repair of congenital heart disease: isolated channels between scars allow "focal" ablation.

BACKGROUND: The purpose of this study was to characterize the circuit of macroreentrant right atrial tachycardia (MacroAT) in patients after surgical repair of congenital heart disease (SR-CHD). METHODS AND RESULTS: Sixteen patients with atrial tachycardia (AT) after SR-CHD were studied (atrial septal defect in 6, tetralogy of Fallot in 4, and Fontan procedure in 6). Electroanatomic right atrial maps were obtained during 15 MacroATs in 13 patients, focal AT in 1 patient, and atrial pacing in 2 patients without stable AT. A large area of low bipolar voltage (/=2 scars forming narrow channels. Ablation within the channels eliminates MacroAT.

Transthoracic two-dimensional high frequency (7.5 MHz) ultrasonic visualization of the distal left anterior descending coronary artery.

High frequency (7.5 MHz) two-dimensional ultrasound in combination with modified acoustic windows allowed visualization of the distal left anterior descending artery in 61 (85%) of 72 patients studied. Visualization was confirmed in one patient who underwent simultaneous high frequency ultrasound recording and selective dye injection into the left coronary artery. In addition, calcific coronary atherosclerosis was identified in one patient. The saphenous vein bypass graft along with its distal site of anastomosis was clearly seen in 3 patients and coronary artery flow was detected in 24 (33%).

Frequency and explanation of false negative diagnosis of aortic dissection by aortography and transesophageal echocardiography.

OBJECTIVES: This study was designed to define the frequency and explanation of false negative diagnosis of aortic dissection by aortography and transesophageal echocardiography. BACKGROUND: Aortography and transesophageal echocardiography have been widely utilized to diagnose aortic dissection. Previous reports have not fully addressed the reasons why these studies yield false negative results in a large number of patients with aortic dissection. METHODS: Sixty-five consecutive patients with aortic dissection underwent aortography and transesophageal echocardiography. Diagnosis of aortic dissection was confirmed at operation or by computed tomography in all patients. RESULTS: Biplane transesophageal echocardiograms yielded false negative results in two patients (sensitivity 97% [63 of 65]). Both patients had well localized DeBakey type II aortic dissection. The diagnosis was probably missed because of image interference from the air-filled trachea and mainstem bronchi. In both patients, the dissection was readily identified by aortography. Aortograms yielded false negative results in 15 patients (sensitivity 77% [50 of 65]); the aortic dissection was type I in 7 patients, type II in 1 and type III in 7. The dissection in all 15 patients was readily identified by transesophageal echocardiography. The missed diagnosis was probably due to a completely thrombosed false lumen or intramural hematoma with noncommunicating dissection in 13 patients and to a large ascending aortic aneurysm with nearly equal flow on both sides of the intimal flap in 2. In no patient was the diagnosis missed by both aortography and transesophageal echocardiography. CONCLUSION: Transesophageal echocardiography is an excellent screening tool for aortic dissection. However, it may miss small type II aortic dissections localized to the upper portion of the ascending aorta because of image interference from the air-filled trachea. An intramural hematoma cannot be easily visualized by aortography, and this lesion is the principal reason for false negative aortographic findings.

Recognition and embolic potential of intraaortic atherosclerotic debris.

Atherosclerotic disease of the thoracic aorta is common in the elderly and patients with clinical coronary artery disease. Although embolization can occur from atherosclerotic debris within the thoracic aorta, it is not commonly considered in the differential diagnosis of the source of a systemic embolism. In the current study, the prevalence, clinical significance and embolic potential of intraaortic atherosclerotic debris as detected by transesophageal echocardiography was determined. Intraaortic atherosclerotic debris was identified in 38 (7%) of 556 patients undergoing transesophageal echocardiography. An embolic event occurred among 11 (31%) of the 36 study patients with intraaortic atherosclerotic debris. The incidence of an embolic event was higher when the debris was pedunculated and highly mobile (8 [73%] of 11 patients) than when it was layered and immobile (3 [12%] of 25 patients) (p less than 0.002). Among 15 patients undergoing an invasive procedure of the aorta, the incidence of embolism was 27%. In conclusion, in a patient with an embolic event, the thoracic aorta should be considered as a potential source. Transesophageal echocardiography can reliably detect intraaortic atherosclerotic debris, and when it is identified, an invasive aortic procedure should be avoided if possible.

Transthoracic high frequency (7.5 MHz) echocardiographic assessment of coronary vascular reserve and its relation to left ventricular mass.

Transthoracic high frequency (7.5 MHz) ultrasonography can visualize the distal left anterior descending coronary artery. Thirty-seven patients were studied before and after administration of 0.4 mg sublingual nitroglycerin to determine whether this technique could quantitatively record changes in coronary artery diameter after intervention. Left anterior descending coronary artery diameter increased from 2.2 to 2.8 mm (p less than 0.05). The vasodilator response of this artery was compared with left ventricular mass index in normal subjects, patients with congestive cardiomyopathy and those with end-stage renal disease and left ventricular hypertrophy. Left anterior descending artery diameter increased 55% in normal subjects, 27% in patients with dilated cardiomyopathy and 10% in those with end-stage renal disease with left ventricular hypertrophy. These results demonstrate that high frequency ultrasound can detect nitroglycerin-induced changes in left anterior descending artery diameter. The percent increase is related to the diameter before nitroglycerin administration, which is related to the underlying diagnosis and left ventricular mass index.

Feasibility of identifying amyloid and hypertrophic cardiomyopathy with the use of computerized quantitative texture analysis of clinical echocardiographic data.

Ultrasound tissue characterization, the evaluation of certain physical properties of a tissue based on its acoustic properties, is an evolving application in echocardiography. The ability to identify acutely and chronically injured tissue has been demonstrated in a number of animal studies, but data in humans are limited. The present study tested the hypothesis that quantitative echocardiographic texture analysis, a method of evaluating the spatial pattern of echoes in echocardiographic images, would differentiate amyloid and hypertrophic cardiomyopathy from normal myocardium. Routine clinical echocardiographic data were obtained on 34 subjects at the Mayo Clinic (10 normal subjects, 10 patients with amyloid heart disease, 8 patients with hypertrophic cardiomyopathy and 6 patients with left ventricular hypertrophy due to hypertension). Standard videotape recordings of these echocardiograms were analyzed at the University of Iowa. Echocardiographic data were digitized with use of a calibrated, 256 gray level digitization system. Quantitative texture analysis was performed on data from the ventricular septum and posterior left ventricular wall in end-diastolic and end-systolic, short-axis and long-axis echocardiographic images. The gray level run length texture variables were able to discriminate hypertrophic cardiomyopathy and amyloid heart disease from normal myocardium and from each other (p less than 0.0083 for comparisons of the quantitative texture features of amyloid versus hypertrophic cardiomyopathy versus normal by multivariate analysis of variance). The texture of the myocardium in hypertensive left ventricular hypertrophy not associated with amyloid or hypertrophic cardiomyopathy was in general not significantly different from that of normal myocardium.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural, spectral, thermodynamical, NLO, HOMO, LUMO and NBO analysis of fluconazole.

Fluconazole is an efficient antifungal drug used in the treatment and prevention of superficial and systemic fungal infections. The molecular structure, fundamental vibrational wavenumber and intensity of the vibrational bands are interpreted, aided by density functional theory method. The results of the calculations were applied to simulated spectra of the title compound, which show excellent agreement with observed spectra. The vibrational analysis of the title compound has been carried out using FT-IR and FT-Raman spectra. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital analysis. The present investigation is extended to calculate the HOMO-LUMO energy gap, polarizability, Mulliken charges and thermodynamical properties of fluconazole at different temperature. The calculated HOMO-LUMO energy gap shows that the charge transfer occurs within the molecule. The frontier orbital and molecular electrostatic potential surface studies have been employed to understand the active sites of fluconazole. Nonlinear optical properties related to polarizability and hyperpolarizability are also discussed. The absorption characteristics and solvent analysis of fluconazole have been made using UV-Vis spectroscopic method.

Prognostic significance of valvular regurgitation in patients with infective endocarditis.

PURPOSE: Doppler ultrasound is a sensitive modality for detecting and quantitating valvular regurgitation in patients with infective endocarditis. Because valvular regurgitation leads to heart failure, we evaluated the prognostic significance of Doppler-detected valvular regurgitation in patients with endocarditis who had not yet developed clinical heart failure. PATIENTS AND METHODS: We reviewed the medical records of 65 patients with a clinical diagnosis of infective endocarditis from May 1985 to March 1990. A total of 49 patients were included in the study: 33 patients with native valve endocarditis and 16 patients with prosthetic valve endocarditis. The initial Doppler echocardiogram was examined in these patients to determine the presence and degree of valvular regurgitation. RESULTS: Significant (moderate to severe) valvular regurgitation was detected in 23 (47%) patients. The presence or absence of significant valvular regurgitation did not predict the development of congestive heart failure, the need for surgery, or death (p = NS). The development of congestive heart failure was significantly associated with the need for surgery (p less than 0.0001) and death (p less than 0.05). CONCLUSION: We conclude that the detection of significant valvular regurgitation in patients with infective endocarditis who have not yet developed heart failure is not predictive of future complications nor does the absence of significant valvular regurgitation identify a group of patients with a more favorable prognosis. In our series, patients who developed congestive heart failure had a significantly higher incidence of surgery and death. Therefore, decisions regarding clinical management in patients with infective endocarditis should not be made solely on the presence or absence of echocardiographically detected valvular regurgitation.

Induction of simian virus 40 transplantation immunity in hamsters by gel-purified SV40 large T antigen.

Simian virus 40 (SV40) large T antigen and p53 cellular protein were isolated from an SV40-transformed hamster cell line by immunoprecipitation with anti-T sera and purified by sodium dodecyl sulfate-gel electrophoresis. These two protein were tested in hamsters for the presence of SV40 transplantation rejection antigenic sites by in vivo transplantation rejection assay. The large T antigen immunized the hamsters against a challenge of SV40 tumor cells and the protected animals generated cytotoxic spleen cells. Hamsters immunized with the p53 cellular protein were not protected against SV40-induced tumor but there was some delay in the appearance of tumor.

Lack of arrhythmogenicity with ST-segment elevation during high-dose of dobutamine atropine stress in patients with documented or suspected coronary artery disease.

The angiographic, echocardiographic, and electrocardiographic correlates of ST-segment elevation during high-dose dobutamine-atropine stress were prospectively looked at in a group of high-risk patients. Unlike exercise-induced ST elevation, ST-segment elevation with dobutamine-atropine stress, while indicating transmural ischemia, did not increase rate of arrhythmias and hence by itself may not be an indication to terminate the test.

Effect of depressed left ventricular function on hemodynamics of normal St. Jude Medical prosthesis in the aortic valve position.

To evaluate the effect of left ventricular (LV) dysfunction on Doppler-derived transprosthetic hemodynamic indexes in patients with normally functioning St. Jude aortic valve prostheses, 74 consecutive patients were studied. LV ejection fraction was assessed by using Simpson's biplane rule. The 34 patients with normal ejection fraction (greater than or equal to 0.51) (group A) generally had the highest values of peak (31 +/- 13 mm Hg) and mean (16 +/- 6 mm Hg) gradients, whereas 19 patients with moderate to severe reduction of ejection fraction (less than or equal to 0.31) (group C) had the lowest values (17 +/- 6 and 9 +/- 3 mm Hg, respectively) (p less than 0.05). Significant decreases (p less than 0.05) for acceleration and corrected (for heart rate) velocity time integral in group C were noted compared to group A, and group B (21 patients with mild to moderately reduced ejection fraction [0.50 to 0.32]). A significant inverse correlation for Doppler-derived peak and mean gradients and corrected velocity time integral was demonstrated with increasing aortic valve prosthetic sizes from 19 to 29 mm in group A patients (r = -0.41 to -0.71) but less so in group B or C. Thus, in addition to valve size, LV function should be considered an important factor in detecting prosthetic valvular flow characteristics and dysfunction. A normal derived velocity and gradient in patients with moderately to severely depressed LV function may not rule out significant valvular stenosis.