MSCT coronary angiography in non-invasive assessment of coronary artery bypass grafts patency

Background: Coronary artery disease (CAD) is one of the leading cause of the morbidity and mortality in India and worldwide and last decade has seen a steep rise in incidence of CAD in India and its treatment as bypass surgery. Direct visualization of the grafts and native coronary arteries by invasive catheterization is now being replaced by non-invasive CT coronary angiography with higher slice machines and newer technology as it has good temporal resolution, high scanning speed as well as low radiation dose. We share our experience of graft imaging on 128 slice CT machine.Methods: This is a retrospective, single-center, observational study. We included 500 symptomatic patients who have undergone CT study between the year 2014 to 2018 post bypass surgery.Results: Arterial grafts have a better patency rate than venous grafts. (88% vs. 64.1%). Amongst the individual arterial grafts RIMA had the best patency rate (100%) followed by LIMA (90.8%), RA (68.7%). LAD was the most commonly involved artery (91%).Conclusions: Significant absolute concordance between CT and catheter angiographic findings have been documented for all arterial and venous grafts patency in the literature. The MSCT with retrospective gating permits an accurate and non-invasive evaluation of patent and diseased arterial and vein grafts and could replace conventional angiography for the follow-up of symptomatic, stable patients. Moreover, an optimal diagnostic accuracy was also documented in the appraisal of native vessels distal to the graft anastomoses

Phenotypic and genomic profiling of Staphylococcus argenteus in Canada and the United States and recommendations for clinical result reporting

Staphylococcus argenteus is a newly described species, formerly known as S. aureus clonal complex 75 (CC75). Here, we describe the largest collection of S. argenteus isolates in North America, highlighting identification challenges. We present phenotypic and genomic characteristics and provide recommendations for clinical reporting. Between 2017 and 2019, 22 isolates of S. argenteus were received at 2 large reference laboratories for identification. Identification with routine methods (biochemical, matrix-assisted laser desorption ionization–time of flight mass spectrometry [MALDI-TOF MS], 16S rRNA gene analysis) proved challenging to confidently distinguish these isolates from S. aureus. Whole-genome sequencing analysis was employed to confirm identifications. Using several different sequence-based analyses, all clinical isolates under investigation were confirmed to be S. argenteus with clear differentiation from S. aureus. Seven of 22 isolates were recovered from sterile sites, 11 from nonsterile sites, and 4 from surveillance screens. While sequence types ST1223/coa type XV, ST2198/coa type XIV, and ST2793/coa type XId were identified among the Canadian isolates, the majority of isolates (73%) belonged to multilocus sequence types (MLST) ST2250/coa type XId and exhibited a high degree of homology at the genomic level. Despite this similarity, 5 spa types were identified among ST2250 isolates, demonstrating some diversity between strains. Several isolates carried mecA, as well as other resistance and virulence determinants (e.g., PVL, TSST-1) commonly associated with S. aureus. Based on our findings, the growing body of literature on S. argenteus, the potential severity of infections, and possible confusion associated with reporting, including use of incorrect breakpoints for susceptibility results, we make recommendations for clinical laboratories regarding this organism

Double outlet of right ventricle: imaging spectrum on multi-slice computed tomography

Background: Multi-slice computed tomography (MSCT) is the main stay of pre-operative assessment of many complex congenital heart diseases (CHD) in current clinical practice, one of them is double outlet of right ventricle (DORV). DORV is one of the conotruncal anomalies that encompasses a wide spectrum of anatomic malformations in which both the aorta and pulmonary arterial trunk arise entirely or predominantly from the morphologically right ventricle (RV). Purpose of this article is to understand spectrum of DORV and associated types of ventricular septal defect (VSD) on MSCT imaging with special emphasis of usefulness of 3-D volume rendered (VR) images in pre surgical evaluation.Methods: A total of 500 paediatric patients (<18 years old), who had undergone MSCT were studied during the period 2014 to 2019 at the tertiary cardiac care centre.Results: 500 patients having primary/suspicious diagnosis of DORV on echocardiography during the said period were enrolled in the study. All the patients who underwent MSCT scan, were studied in detail for: DORV spectrum, associated types of VSD and its relationship to the semilunar valves. Out of 500 total subjects, subaortic VSD was the most common type of VSD observed (53%), followed by subpulmonic VSD (22%), non-committed VSD (18%) and doubly committed VSD (7%). Associations of pulmonary stenosis, subaortic stenosis and aortic co-arctation with various types of VSDs were addressed. Associated other anomalies were also analysed.Conclusions: Advances in MSCT technology has revolutionized pre-surgical diagnosis, management approach and post-operative follow-up of DORV patients. Excellent image qualities along with 3D volume rendered images help surgeon understand complex morphology of DORV variants and associated types of VSD. Significant reduction in intra and post-operative mortality in DORV patients in current era is result of MSCT technology

Mitochondria Exert Age-Divergent Effects on Recovery from Spinal Cord Injury

The extent that age-dependent mitochondrial dysfunction drives neurodegeneration is not well understood. This study tested the hypothesis that mitochondria contribute to spinal cord injury (SCI)-induced neurodegeneration in an age-dependent manner by using 2,4-dinitrophenol (DNP) to uncouple electron transport, thereby increasing cellular respiration and reducing reactive oxygen species (ROS) production. We directly compared the effects of graded DNP doses in 4- and 14-month-old (MO) SCI-mice and found DNP to have increased efficacy in mitochondria isolated from 14-MO animals. In vivo, all DNP doses significantly exacerbated 4-MO SCI neurodegeneration coincident with worsened recovery. In contrast, low DNP doses (1.0-mg/kg/day) improved tissue sparing, reduced ROS-associated 3-nitrotyrosine (3-NT) accumulation, and improved anatomical and functional recovery in 14-MO SCI-mice. By directly comparing the effects of DNP between ages we demonstrate that mitochondrial contributions to neurodegeneration diverge with age after SCI. Collectively, our data indicate an essential role of mitochondria in age-associated neurodegeneration

C5 deficiency and C5a or C5aR blockade protects against cerebral malaria

Experimental infection of mice with Plasmodium berghei ANKA (PbA) provides a powerful model to define genetic determinants that regulate the development of cerebral malaria (CM). Based on the hypothesis that excessive activation of the complement system may confer susceptibility to CM, we investigated the role of C5/C5a in the development of CM. We show a spectrum of susceptibility to PbA in a panel of inbred mice; all CM-susceptible mice examined were found to be C5 sufficient, whereas all C5-deficient strains were resistant to CM. Transfer of the C5-defective allele from an A/J (CM resistant) onto a C57BL/6 (CM-susceptible) genetic background in a congenic strain conferred increased resistance to CM; conversely, transfer of the C5-sufficient allele from the C57BL/6 onto the A/J background recapitulated the CM-susceptible phenotype. The role of C5 was further explored in B10.D2 mice, which are identical for all loci other than C5. C5-deficient B10.D2 mice were protected from CM, whereas C5-sufficient B10.D2 mice were susceptible. Antibody blockade of C5a or C5a receptor (C5aR) rescued susceptible mice from CM. In vitro studies showed that C5a-potentiated cytokine secretion induced by the malaria product P. falciparum glycosylphosphatidylinositol and C5aR blockade abrogated these amplified responses. These data provide evidence implicating C5/C5a in the pathogenesis of CM

Characterization of Errors in Retinopathy of Prematurity Diagnosis by Ophthalmologists-in-Training in the United States and Canada

PURPOSE: To identify the prominent factors that lead to misdiagnosis of retinopathy of prematurity (ROP) by ophthalmologists-in-training in the United States and Canada. METHODS: This prospective cohort study included 32 ophthalmologists-in-training at six ophthalmology training programs in the United States and Canada. Twenty web-based cases of ROP using wide-field retinal images were presented, and ophthalmologists-in-training were asked to diagnose plus disease, zone, stage, and category for each eye. Responses were compared to a consensus reference standard diagnosis for accuracy, which was established by combining the clinical diagnosis and the image-based diagnosis by multiple experts. The types of diagnostic errors that occurred were analyzed with descriptive and chi-squared analysis. Main outcome measures were frequency of types (category, zone, stage, plus disease) of diagnostic errors; association of errors in zone, stage, and plus disease diagnosis with incorrectly identified category; and performance of ophthalmologists-in-training across postgraduate years. RESULTS: Category of ROP was misdiagnosed at a rate of 48%. Errors in classification of plus disease were most commonly associated with misdiagnosis of treatment-requiring (plus error rate = 16% when treatment-requiring was correctly diagnosed vs 81% when underdiagnosed as type 2 or pre-plus; mean difference: 64.3; 95% CI: 51.9 to 76.7; CONCLUSIONS: Ophthalmologists-in-training in the United States and Canada misdiagnosed ROP nearly half of the time, with incorrect identification of plus disease as a leading cause. Integration of structured learning for ROP in residency education may improve diagnostic competency