Clinically significant blunt cardiac trauma: role of serum troponin levels combined with electrocardiographic findings

BACKGROUND: The true importance of blunt cardiac trauma (BCT) is related to the cardiac complications arising from it. Diagnostic tests that can predict accurately if such complications will develop or not may allow early and aggressive monitoring or early discharge. We investigated the role of two simple and convenient tests, serum cardiac troponin I (cTnI) and electrocardiogram (ECG), when used to identify patients at risk of cardiac complications after BCT. METHODS: Over a 10-month period, 115 patients with evidence of significant blunt thoracic trauma were prospectively followed to identify the presence of clinically significant BCT (Sig-BCT), defined as cardiogenic shock, arrhythmias requiring treatment, or structural cardiac abnormalities directly related to the cardiac trauma. An ECG was obtained at admission and at 8 hours. Cardiac troponin I was measured at admission, at 4 hours, and at 8 hours. Transthoracic echocardiography was performed when clinically indicated. The sensitivity, specificity, and positive and negative predictive values of ECG and cTnI to identify Sig-BCT were calculated. Clinical risk factors for Sig-BCT were examined by univariate and multivariate analysis. RESULTS: Nineteen patients (16.5%) were diagnosed with Sig-BCT and, in 18 of them, symptoms presented within 24 hours of admission. Abnormal electrocardiographic findings were detected in 58 patients (50%) and elevated cTnI levels in 27 (23.5%). Electrocardiography and cTnI had positive predictive values of 28% and 48% and negative predictive values of 95% and 93%, respectively. However, when both tests were abnormal (positive) or normal (negative), the positive and negative predictive values increased to 62% and 100%, respectively. Other independent risk factors for Sig-BCT were head injury, spinal injury, history of preexisting cardiac disease, and a chest Abbreviated Injury Score greater than 2. CONCLUSION: The combination of ECG and cTnI identifies reliably the presence or absence of Sig-BCT. Patients with an abnormal ECG and cTnI need close monitoring for at least 24 hours. Patients with a normal admission ECG and cTnI can be safely discharged in the absence of other injuries.     

Non-Invasive Hemodynamic Assessment of Aortic Coarctation: Validation with In Vivo Measurements

We propose a CFD-based approach for the non-invasive hemodynamic assessment of pre- and post-operative coarctation of aorta (CoA) patients. Under our approach, the pressure gradient across the coarctation is determined from computational modeling based on physiological principles, medical imaging data, and routine non-invasive clinical measurements. The main constituents of our approach are a reduced-order model for computing blood flow in patient-specific aortic geometries, a parameter estimation procedure for determining patient-specific boundary conditions and vessel wall parameters from non-invasive measurements, and a comprehensive pressure-drop formulation coupled with the overall reduced-order model. The proposed CFD-based algorithm is fully automatic, requiring no iterative tuning procedures for matching the computed results to observed patient data, and requires approximately 6–8 min of computation time on a standard personal computer (Intel Core2 Duo CPU, 3.06 GHz), thus making it feasible for use in a clinical setting. The initial validation studies for the pressure-drop computations have been performed on four patient datasets with native or recurrent coarctation, by comparing the results with the invasively measured peak pressure gradients recorded during routine cardiac catheterization procedure. The preliminary results are promising, with a mean absolute error of less than 2 mmHg in all the patients.     

Electronic and optical properties of monolayer MoS2 under the influence of polyethyleneimine adsorption and pressure

MoS₂ is one of the well-known transition metal dichalcogenides. The moderate bandgap of monolayer MoS₂ is fascinating for the new generation of optoelectronic devices. Unfortunately, MoS₂ is sensitive to gases in the environment causing its original electronic properties to be modified unexpectedly. This problem has been solved by coating MoS₂ with polymers such as polyethyleneimine (PEI). Furthermore, the application of pressure is also an effective method to modify the physical properties of MoS₂. However, the effects of polyethyleneimine and pressure on the electronic and optical properties of monolayer MoS₂ remain unknown. Therefore, we elucidated this matter by using density functional theory calculations. The results showed that the adsorption of the PEI molecule significantly reduces the width of the direct bandgap of the monolayer MoS₂ to 0.55 eV because of the occurrence of the new energy levels in the bandgap region due to the contribution of the N-2p_z state of the PEI molecule. Remarkably, the transition from semiconductor to metal of the monolayer MoS₂ and the MoS₂/PEI system occurs at the tensile pressure of 24.95 and 21.79 GPa, respectively. The bandgap of these systems approaches 0 eV at the corresponding pressures. Importantly, new peaks in the optical spectrum of the clean MoS₂ and MoS₂/PEI appear in the ultraviolet region under compressive pressures and the infrared region under tensile strains.

Pressure modifies both electronic and optical properties; however, PEI adsorption only alters the electronic structure of monolayer MoS₂.     

Myocardial degradation and left bundle branch block predict conversion to low ejection fraction in heart failure with preserved systolic function

The authors prospectively investigated whether left bundle branch block (LBBB) and myocardial degradation as indicated by elevated troponin T (tnT) predict the phenomenon of systolic conversion to low ejection fraction (EF 40%). Thirty consecutive patients with HFPSF were included and followed over a 4-year interval. A follow-up EF assessment was performed in 25 patients. Six of 15 patients with tnT >or=0.01 ng/mL demonstrated systolic conversion to low EF on follow-up, while none of the 10 patients with tnT <0.01 ng/mL experienced this phenomenon (P=.03). Five of the 6 converters presented with LBBB, while only 1 of the 19 nonconverters had this abnormality (P=.0007). Four of the 6 converters had an initial EF >50%. Myocardial degradation and LBBB predicted systolic conversion in HFPSF patients with nonsignificant coronary disease.     

Aristolochic acid exposure in Romania and implications for renal cell carcinoma

Background:

Aristolochic acid (AA) is a nephrotoxicant associated with AA nephropathy (AAN) and upper urothelial tract cancer (UUTC). Whole-genome sequences of 14 Romanian cases of renal cell carcinoma (RCC) recently exhibited mutational signatures consistent with AA exposure, although RCC had not been previously linked with AAN and AA exposure was previously reported only in localised rural areas.

Methods:

We performed mass spectrometric measurements of the aristolactam (AL) DNA adduct 7-(deoxyadenosin-N⁶-yl) aristolactam I (dA-AL-I) in nontumour renal tissues of the 14 Romanian RCC cases and 15 cases from 3 other countries.

Results:

We detected dA-AL-I in the 14 Romanian cases at levels ranging from 0.7 to 27 adducts per 10⁸ DNA bases, in line with levels reported in Asian and Balkan populations exposed through herbal remedies or food contamination. The 15 cases from other countries were negative.

Interpretation:

Although the source of exposure is uncertain and likely different in AAN regions than elsewhere, our results demonstrate that AA exposure in Romania exists outside localised AAN regions and provide further evidence implicating AA in RCC.     

Traditional and novel approaches to management of heart failure: successes and failures

Although considerable progress has been made in the pharmacologic and device management of chronic heart failure in recent decades, heart failure patients continue to remain symptomatic, with high hospitalization and mortality rates. A number of novel agents, including endothelin antagonists and tumor-necrosis factor blockers, have recently failed to improve the clinical outcomes of patients with heart failure. Have we reached a ceiling in preventing the progression of the disease? This article reviews successes and late-stage clinical trial disappointments in the treatment of patients with heart failure. Furthermore, the article discusses how agents that have beneficial effects in heart failure also generally attenuate or reverse ventricular remodeling, whereas the newer agents that have failed to improve clinical outcomes either had no effect on remodeling or have been associated with adverse remodeling.     

Variations of the renal function parameters in rectal cancer patients with a defunctioning loop ileostomy

Purpose

The objective of this study is to investigate the impact of the temporary loop ileostomy on renal function and also to assess the factors associated with the change in renal function observed between the index surgery (the moment of the radical surgical procedure) and the closure of the ileostomy (the moment of the secondary surgical act of suppression of the ileostomy).

Methods

A total of 69 rectal cancer patients from a single referral surgical unit who had a loop ileostomy during low anterior resection of the rectum were included in this study. Serum creatinine levels were evaluated, and estimated glomerular filtration rate (eGFR) was calculated prior to index surgery and closure of the ileostomy.

Results

During this time interval, there was a significant decrease in eGFR levels (mean difference ??4.5 mL/min/1.73 m², 95% CI ??7.8 to ??1.3 mL/min/1.73 m²), and also a significant increase in the serum creatinine values (mean difference 0.07, 95% CI 0.02–0.12 mg/dL). The eGFR decrease was more pronounced in diabetic patients, in those with a baseline Charlson Comorbidity Index score?≥?1 or in those that received chemotherapy. In a multivariable regression analysis, the use of neoadjuvant chemotherapy was the only variable significantly associated with the change in eGFR levels between the two surgical interventions.

Conclusion

Renal function impairment is an important event that the surgeon has to take into consideration when deciding upon opting for a loop ileostomy to temporarily defunction a colorectal anastomosis.

     

Comprehensive preclinical evaluation of a multi-physics model of liver tumor radiofrequency ablation

Purpose

We aim at developing a framework for the validation of a subject-specific multi-physics model of liver tumor radiofrequency ablation (RFA).

Methods

The RFA computation becomes subject specific after several levels of personalization: geometrical and biophysical (hemodynamics, heat transfer and an extended cellular necrosis model). We present a comprehensive experimental setup combining multimodal, pre- and postoperative anatomical and functional images, as well as the interventional monitoring of intra-operative signals: the temperature and delivered power.

Results

To exploit this dataset, an efficient processing pipeline is introduced, which copes with image noise, variable resolution and anisotropy. The validation study includes twelve ablations from five healthy pig livers: a mean point-to-mesh error between predicted and actual ablation extent of 5.3 ± 3.6 mm is achieved.

Conclusion

This enables an end-to-end preclinical validation framework that considers the available dataset.

     

A novel proteolytic processing of prolysyl oxidase

Lysyl oxidase (LOX) is an amine oxidase that is critical for the stability of connective tissues. The secreted proLOX is enzymatically quiescent and is activated through proteolytic cleavage between residues Gly(162) and Asp(163) (residue numbers according to the mouse LOX) by bone morphogenetic protein (BMP)-1 gene products. Here we report a novel processing of proLOX identified in vitro and in vivo. Two forms of mature LOX were identified and characterized by their immunoreactivity to specific antibodies, amine oxidase activity, and mass spectrometry. One form was identified as a well-characterized BMP-1 processed LOX protein. Another was found to be a truncated form of LOX resulting from the cleavage at the carboxy terminus of Arg(192). The truncated form of LOX still appeared to retain amine oxidase activity. The results from the proLOX gene deletion and mutation experiments indicated that the processing occurs independent of the cleavage of proLOX by BMP-1 gene products and likely requires the presence of LOX propeptide. These results indicate that proLOX could be processed by two different mechanisms producing two forms of active LOX.