Valve repair after infective endocarditis secondary to perforation caused by Streptococcus gordonii: A case report.

BACKGROUND: We report a case of infective endocarditis (IE) in a patient with congenital heart valve lesions accompanied by IE, which was diagnosed based on blood culture analysis that revealed the presence of a gram-negative bacterium, Streptococcus gordonii. CASE SUMMARY: The patient had a history of precordial valve disease diagnosed by cardiac ultrasound, as well as a 4-mo history of fever. He was subjected to comprehensive anti-infection and anti-heart failure treatment in the internal medicine department. Further examination revealed sudden dislodgement from and perforation through the aortic valve by the superfluous organisms, as well as occurrence of bacterial emboli dislodgement, which caused bacteremia and infectious shock. He recovered and was discharged from the hospital after surgical and postoperative anti-infection treatments. CONCLUSION: We review the treatment process and highlight inspirations and reflections from this case; suggest possible future changes in treatment modalities.

Physicians' knowledge and sepsis guide implementation in tertiary care hospitals in China.

BACKGROUND: This study was designed to investigate the extent to which physicians involved in sepsis management understand and adopt sepsis guidelines in clinical practice. The overarching aim of this study was to generate ideas for developing more effective training methods to help physicians apply the guidelines in patient management. METHODS: Physicians working in a tertiary care hospital, primarily in the emergency and critical care departments, were recruited into the survey. They were asked to fill questionnaires which were designed to collect sepsis score, diagnostic indicators, fluid resuscitation, antibiotics choice, access to knowledge and training, as well as implementation of sepsis guidelines in clinical diagnosis and treatment. RESULTS: Overall, the response rate was 625/661 (94.5%). The investigate shows the basic information of all physicians who participated in the answer sheet, including their work department, professional title and whether their hospital was a teaching hospital. Significant differences were identified among the physicians in terms of method of acquiring sepsis guidelines, the impact of study guidelines on clinical diagnosis and treatment, efficiency of training methods, cognition of fluid resuscitation in patients with sepsis, the cognition of sepsis rehydration principles, selection of antibiotics for patients with sepsis, the basis for antibiotic selection, among other variables. CONCLUSION: Although majority of physicians involved in tertiary care hospital understand the contents of sepsis-3 guidelines, the clinical implementation of the guidelines in the diagnosis and treatment of patients with sepsis is highly heterogeneous. Thus, there is need to develop standardized training for physicians involved in sepsis diagnosis and treatment.

Improving liver tumor image contrast and synthesizing novel tissue contrasts by adaptive multiparametric MRI fusion.

Purpose: Multiparametric MRI contains rich and complementary anatomical and functional information, which is often utilized separately. This study aims to propose an adaptive multiparametric MRI (mpMRI) fusion method and examine its capability in improving tumor contrast and synthesizing novel tissue contrasts among liver cancer patients. Methods: An adaptive mpMRI fusion method was developed with five components: image pre-processing, fusion algorithm, database, adaptation rules, and fused MRI. Linear-weighted summation algorithm was used for fusion. Weight-driven and feature-driven adaptations were designed for different applications. A clinical-friendly graphic-user-interface (GUI) was developed in Matlab and used for mpMRI fusion. Twelve liver cancer patients and a digital human phantom were included in the study. Synthesis of novel image contrast and enhancement of image signal and contrast were examined in patient cases. Tumor contrast-to-noise ratio (CNR) and liver signal-to-noise ratio (SNR) were evaluated and compared before and after mpMRI fusion. Results: The fusion platform was applicable in both XCAT phantom and patient cases. Novel image contrasts, including enhancement of soft-tissue boundary, vertebral body, tumor, and composition of multiple image features in a single image were achieved. Tumor CNR improved from -1.70 ± 2.57 to 4.88 ± 2.28 (p < 0.0001) for T1-w, from 3.39 ± 1.89 to 7.87 ± 3.47 (p < 0.01) for T2-w, and from 1.42 ± 1.66 to 7.69 ± 3.54 (p < 0.001) for T2/T1-w MRI. Liver SNR improved from 2.92 ± 2.39 to 9.96 ± 8.60 (p < 0.05) for DWI. The coefficient of variation (CV) of tumor CNR lowered from 1.57, 0.56, and 1.17 to 0.47, 0.44, and 0.46 for T1-w, T2-w and T2/T1-w MRI, respectively. Conclusion: A multiparametric MRI fusion method was proposed and a prototype was developed. The method showed potential in improving clinically relevant features such as tumor contrast and liver signal. Synthesis of novel image contrasts including the composition of multiple image features into single image set was achieved.

Slice-stacking T2-weighted MRI for fast determination of internal target volume for liver tumor.

BACKGROUND: To investigate the feasibility of generating maximum intensity projection (MIP) images to determine internal target volume (ITV) using slice-stacking MRI (SS-MRI) technique. METHODS: Slice-stacking is a technique which applies a multi-slice MRI acquisition to generate a 3D MIP for ITV contouring, without reconstructing 4D-MRI. 4D digital extended cardiac-torso (XCAT) phantom was used to generate MIP images with sequential 2D HASTE sequence, with different tumor diameters (10, 30 and 50 mm) and with simulated regular and irregular (patient) breathing motions. A reference MIP was generated using all acquisition images. Consecutive repetitions were then used to generate MIP to analyze the relationship between Dice's similarity coefficient (DSC) and the number of repetitions, and the relationship between the relative ITV volume difference and the number of repetitions. Images from XCAT phantom and from three hepatic carcinoma patients were collected in this study to demonstrate the feasibility of this technique. RESULTS: For both regular and irregular breathing motion, the average DSC of ITV is >0.94 and the average relative ITV volume difference is <10% (approximately 0.15 cm3) when using 5 repeated scanning images to reconstruct MIP for tumor diameter of 10 mm. As tumor diameter increases, the DSC of ITV is >0.97 and the relative ITV volume difference is <5% for regular breathing motion, and the DSC of ITV is >0.97 and the relative ITV volume difference is <5.5% for irregular breathing motion when using 5 repeated scanning images to reconstruct MIP. In patient image study, the mean relative ITV volume difference is <3% and the mean DSC is 0.99 when using 5 repeated scanning images to reconstruct MIP. CONCLUSIONS: The number of scans required to generate tumor ITV for slice-stacking method (5-7 repetition) is 3-4 times less than that of 4D-MRI (15-20 repetitions). It is feasible to generate a fast clinically acceptable ITV using slice-stacking method with sequential 2D MR images.

The HDL from septic-ARDS patients with composition changes exacerbates pulmonary endothelial dysfunction and acute lung injury induced by cecal ligation and puncture (CLP) in mice.

BACKGROUND: Septic-acute respiratory distress syndrome (ARDS), characterized by the acute lung injury (ALI) secondary to aberrant systemic inflammatory response, has high morbidity and mortality. Despite increased understanding of ALI pathogenesis, the therapies to prevent lung dysfunction underlying systemic inflammatory disorder remain elusive. The high density lipoprotein (HDL) has critical protective effects in sepsis and its dysfunction has a manifested contribution to septic organ failure. However, the adverse changes in HDL composition and function in septic-ARDS patients are large unknown. METHODS: To investigate HDL remodeling in septic-ARDS, we analyzed the changes of HDL composition from 40 patients with septic-ARDS (A-HDL) and 40 matched normal controls (N-HDL). To determine the deleterious functional remodeling of HDL, A-HDL or N-HDL was administrated to C57BL/6 and apoA-I knock-out (KO) mice after cecal ligation and puncture (CLP) procedure. Mouse lung microvascular endothelial cells (MLECs) were further treated by these HDLs to investigate whether the adverse effects of A-HDL were associated with endothelial dysfunction. RESULTS: Septic-ARDS patients showed significant changes of HDL composition, accompanied with significantly decreased HDL-C. We further indicated that A-HDL treatment aggravated CLP induced ALI. Intriguingly, these deleterious effects of A-HDL were associated with pulmonary endothelial dysfunction, rather than the increased plasma lipopolysaccharide (LPS). Further in vitro results demonstrated the direct effects of A-HDL on MLECs, including increased endothelial permeability, enhanced expressions of adhesion proteins and pro-inflammatory cytokines via activating NF-κB signaling and decreased junction protein expression. CONCLUSIONS: Our results depicted the remodeling of HDL composition in sepsis, which predisposes lung to ARDS via inducing ECs dysfunction. These results also demonstrated the importance of circulating HDL in regulating alveolar homeostasis.

Maintenance of spontaneous breathing at an intensity of 60%-80% may effectively prevent mechanical ventilation-induced diaphragmatic dysfunction.

Controlled mechanical ventilation (CMV) can cause diaphragmatic motionlessness to induce diaphragmatic dysfunction. Partial maintenance of spontaneous breathing (SB) can reduce ventilation-induced diaphragmatic dysfunction (VIDD). However, to what extent SB is maintained in CMV can attenuate or even prevent VIDD has been rarely reported. The current study aimed to investigate the relationship between SB intensity and VIDD and to identify what intensity of SB maintained in CMV can effectively avoid VIDD. Adult rats were randomly divided according to different SB intensities: SB (0% pressure controlled ventilation (PCV)), high-intensity SB (20% PCV), medium-intensity SB (40% PCV), medium-low intensity SB (60% PCV), low-intensity SB (80% PCV), and PCV (100% PCV). The animals underwent 24-h controlled mechanical ventilation (CMV). The transdiaphragmatic pressure (Pdi), the maximal Pdi (Pdi max) when phrenic nerves were stimulated, Pdi/Pdi max, and the diaphragmatic tonus under different frequencies of electric stimulations were determined. Calpain and caspase-3 were detected using ELISA and the cross-section areas (CSAs) of different types of muscle fibers were measured. The Pdi showed a significant decrease from 20% PCV and the Pdi max showed a significant decrease from 40% PCV (P<0.05). In vivo and vitro diaphragmatic tonus exhibited a significant decrease from 40% PCV and 20% PCV, respectively (P<0.05). From 20% PCV, the CSAs of types I, IIa, and IIb/x muscle fibers showed significant differences, which reached the lowest levels at 100% PCV. SB intensity is negatively associated with the development of VIDD. Maintenance of SB at an intensity of 60%-80% may effectively prevent the occurrence of VIDD.

Evaluation of dosimetric uncertainty caused by MR geometric distortion in MRI-based liver SBRT treatment planning.

PURPOSE: MRI-based treatment planning is a promising technique for liver stereotactic-body radiation therapy (SBRT) treatment planning to improve target volume delineation and reduce radiation dose to normal tissues. MR geometric distortion, however, is a source of potential error in MRI-based treatment planning. The aim of this study is to investigate dosimetric uncertainties caused by MRI geometric distortion in MRI-based treatment planning for liver SBRT. MATERIALS AND METHODS: The study was conducted using computer simulations. 3D MR geometric distortion was simulated using measured data in the literature. Planning MR images with distortions were generated by integrating the simulated 3D MR geometric distortion onto planning CT images. MRI-based treatment plans were then generated on the planning MR images with two dose calculation methods: (1) using original CT numbers; and (2) using organ-specific assigned CT numbers. Dosimetric uncertainties of various dose-volume-histogram parameters were determined as their differences between the simulated MRI-based plans and the original clinical CT-based plans for five liver SBRT cases. RESULTS: The average simulated distortion for the five liver SBRT cases was 2.77 mm. In the case of using original CT numbers for dose calculation, the average dose uncertainties for target volumes and critical structures were <0.5 Gy, and the average target volume percentage at prescription dose uncertainties was 0.97%. In the case of using assigned CT numbers, the average dose uncertainties for target volumes and critical structures were <1.0 Gy, and the average target volume percentage at prescription dose uncertainties was 2.02%. CONCLUSIONS: Dosimetric uncertainties caused by MR geometric distortion in MRI-based liver SBRT treatment planning was generally small (<1 Gy) when the distortion is 3 mm.