Early triage echocardiography to predict outcomes in patients admitted with COVID-19: a multicenter study.

INTRODUCTION: Cardiac involvement seems to impact prognosis of COVID-19, especially in critically ill patients. We aimed to assess the prognostic value of right ventricular (RV) and left ventricular (LV) dysfunction, evaluated by bedside triage echocardiography (echo), in patients admitted to emergency departments (ED) in the US with COVID-19. We also assessed the feasibility of using cloud imaging for sharing and interpreting echocardiograms. METHODS: Patients admitted to three reference EDs with confirmed COVID-19 underwent triage echo within 72 h of symptom onset with remote interpretation. Clinical and laboratory data, as well as COVID-19 symptoms, were collected. The association between echo variables, demographics and clinical data with all-cause hospital mortality and intensive care unit (ICU) admission was assessed using logistic regression. RESULTS: Three hundred ninety-nine patients were enrolled, 41% women, with a mean age of 62±16 years. Mean oxygen saturation on presentation was 92.3± 9.2%. Compared to in-hospital survivors, non-survivors were older, had lower oxygen saturation on presentation, were more likely to have a chronic condition and had lower LV ejection fraction (50.3±19.7% vs. 58.0±13.6%) (P < .05). In the cohort, 101 (25%) patients had moderate/severe LV dysfunction, 131 (33%) had moderate/severe RV dysfunction. Advanced age and lower oxygen saturation were independently associated with death and ICU admission. LV and RV function, or other echo variables, were not independent predictors of outcomes. CONCLUSION: In patients admitted with COVID-19 undergoing early echo triage, the independent predictors of death and ICU admission were age and oxygen saturation. The inclusion of echo variables did not improve prediction of unfavorable outcomes.

Multimodality Imaging in Arrhythmogenic Right Ventricular Cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare, heritable myocardial disease associated with the development of ventricular arrhythmias, heart failure, and sudden cardiac death in early adulthood. Multimodality imaging is a central component in the diagnosis and evaluation of ARVC. Diagnostic criteria established by an international task force in 2010 include noninvasive parameters from echocardiography and cardiac magnetic resonance imaging. These criteria identify right ventricular structural abnormalities, chamber and outflow tract dilation, and reduced right ventricular function as features of ARVC. Echocardiography is a widely available and cost-effective technique, and it is often selected for initial evaluation. Beyond fulfillment of diagnostic criteria, features such as abnormal tricuspid annular plane excursion, increased right ventricular basal diameter, and abnormal strain patterns have been described. 3-dimensional echocardiography may also expand opportunities for structural and functional assessment of ARVC. Cardiac magnetic resonance has the ability to assess morphological and functional cardiac features of ARVC and is also a core modality in evaluation, however, tissue characterization of the right ventricle is limited by spatial resolution and low specificity for detection of pathological changes. Nonetheless, the ability of cardiac magnetic resonance to identify left ventricular involvement, offer high negative predictive value, and provide a reproducible structural evaluation of the right ventricle enhance the ability and scope of the modality. In this review, the prognostic significance of multimodality imaging is outlined, including the supplemental value of multidetector computed tomography and nuclear imaging. Strengths and weaknesses of imaging techniques, as well as future direction of multimodality assessment, are also described.

Ventricular fibrillation in a left ventricular assist device patient: Can the echocardiogram be misleading?

Sustained ventricular tachycardia and ventricular fibrillation (VF) are life-threatening arrhythmias which remain highly prevalent in patients with advanced heart failure. These ventricular arrhythmias may impair the support provided by continuous-flow left ventricular assist devices (CF-LVADs) and lead to frequent hospitalizations, antiarrhythmic medication use, external defibrillations, and need for heart transplantation. We report a case in which a patient with a CF-LVAD and an implantable cardioverter defibrillator at end of life presented with asymptomatic low-flow alarms and was found to have VF of unknown duration. Unique in our case was the presence of apparent organized contractility and rhythmic opening of the mitral valve on echocardiogram despite VF on electrocardiogram.

Right Ventricular Strain Predicts Structural Disease Progression in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy.

Background Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited condition associated with ventricular arrhythmias and myocardial dysfunction; however, limited data exist on identifying patients at highest risk. The purpose of the study was to determine whether measures of right ventricular (RV) dysfunction on echocardiogram including RV strain were predictive of structural disease progression in ARVC. Methods and Results A retrospective analysis of serial echocardiograms from 40 patients fulfilling 2010 task force criteria for ARVC was performed to assess structural progression defined by an increase in proximal RV outflow tract dimensions (parasternal short or long axis) or decrease in RV fractional area change. Echocardiograms were analyzed for RV free-wall peak longitudinal systolic strain using 2-dimensional speckle tracking. Risk of structural progression and 5-year change in RV outflow tract measurements were compared with baseline RV strain. Of the 40 ARVC patients, 61% had structural progression with an increase in the mean parasternal short-axis RV outflow tract dimension from 36.2 to 38.5 mm (P=0.022) and 68% by increase in parasternal long-axis RV outflow tract dimension from 36.1 to 39.2 mm (P=0.001). RV fractional area change remained stable over time. Baseline RV strain was significantly associated with the risk of structural progression and 5-year rate of change. Patients with an RV strain more positive than -20% had a higher risk (odds ratio: 18.4; 95% CI, 2.7-125.8; P=0.003) of structural progression. Conclusions RV free wall strain is associated with the rate of structural progression in patients with ARVC. It may be a useful marker in determining which patients require closer follow-up and treatment.

Comparative Evaluation of Effect of Lasers and Biodentine in Dentine Regeneration: A Clinical Study.

AIM: To compare and evaluate the effect of different liners separately and in combination with lasers that is resin modified glass-ionomer cement (RMGIC), Laser+RMGIC, Biodentine, Laser+Biodentinein the treatment of deep carious lesions. MATERIALS AND METHODS: Forty patients with deep caries indicated for pulp capping were selected. Curative procedure including the cavity preparation with maximal removal of softened dentine using spoon excavator, slow speed handpiece with round burs was performed. Patients were divided into four groups with 10 patients in each group In group A RMGIC liner, group B laser biostimulation followed by RMGIC liner, group C biodentine liner, group D laser biostimulation followed by Biodentine liner were placed in the cavity after caries removal. Cavities were temporarily restored with IRM for 8 weeks. After 8 weeks, liners in each group were removed, and cavities were permanently restored lower half of the cavity with a layer of flowable Z350 XT composite, and then the remaining half of the cavity with P60 filled composites (3 M ESPE, USA) in all the groups. The observation period was 12 months. RESULTS: All the patients showed a positive response to cold test and electric pulp test at 3 months, 6 months, 12 months follow-up. In group A (RMGIC) two patients and in group B (Laser+Biodentine) three patients did not return back for the follow-up. To standardize the samples, seven patients were selected from each group with a total of 28 samples included in the study (n = 7) and statistical analysis was done using analysis of variance (ANOVA) test. The mean for the total amount of dentine deposited after 12 months was highest in: Group D-(Laser+Biodenitne) 0.32 mm > Group C-(Biodentine) 0.25 mm > Group B-(Laser+RMGIC) 0.10 > Group A-(RMGIC) 0.07 mm Conclusion: Within the limitation of the present study the following conclusion was drawn: • Lasers and biodentine are good indirect pulp capping agents • Laser has an additional effect on the tertiary dentine formation. CLINICAL SIGNIFICANCE: Lasers with antibacterial effect penetrate into dentinal tubules and accelerate the rate of dentin bridge formation in deep carious lesions.

Large and Uniform Optical Emission Shifts in Quantum Dots Strained along Their Growth Axis.

We introduce a calibration method to quantify the impact of external mechanical stress on the emission wavelength of distinct quantum dots (QDs). Specifically, these emitters are integrated in a cross-section of a semiconductor core wire and experience a longitudinal strain that is induced by an amorphous capping shell. Detailed numerical simulations show that, thanks to the shell mechanical isotropy, the strain in the core is uniform, which enables a direct comparison of the QD responses. Moreover, the core strain is determined in situ by an optical measurement, yielding reliable values for the QD emission tuning slope. This calibration technique is applied to self-assembled InAs QDs submitted to incremental elongation along their growth axis. In contrast to recent studies conducted on similar QDs submitted to a uniaxial stress perpendicular to the growth direction, optical spectroscopy reveals up to ten times larger tuning slopes, with a moderate dispersion. These results highlight the importance of the stress direction to optimize the QD optical shift, with general implications, both in static and dynamic regimes. As such, they are in particular relevant for the development of wavelength-tunable single-photon sources or hybrid QD opto-mechanical systems.

Demographic and clinical predictors of leptomeningeal collaterals in stroke patients.

BACKGROUND: Leptomeningeal collaterals improve outcome after stroke, including reduction of hemorrhagic complications after thrombolytic or endovascular therapy, smaller infarct size, and reduction in symptoms at follow-up evaluation. The purpose of this study was to determine the demographic and clinical variables that are associated with a greater degree of cerebral collaterals. METHODS: Clinical data of patients presenting with M1 occlusions of the middle cerebral artery (MCA) and associated computed tomography angiography studies after admission from 3 separate institutions were retrospectively compiled (n = 82). Occluded hemispheres were evaluated against the intact hemisphere for degree of collateralization in the MCA territory. Regression analysis of variance was conducted between clinical variables and collateral score to determine which variables associate with greater collateral development. RESULTS: Smaller infarct size corresponded to greater collateral scores, whereas older age and statin use corresponded to lower collateral scores (P < .001). CONCLUSIONS: Cerebral collateralization is influenced by age and statin use and influences infarct size.

Vasculopathy, inflammation, and blood flow in leg ulcers of patients with sickle cell anemia.

Chronic leg ulcers are frequent and debilitating complications of sickle cell anemia. Inadequate blood supply has been postulated to be an important factor in their occurrence and delayed healing. Little is known about their microcirculatory and histopathological changes. We evaluated the microcirculation of lower extremity ulcers with laser speckle contrast imaging and infrared thermography and obtained clinical and laboratory characteristics in 18 adults with sickle cell anemia and chronic leg ulcers. Skin biopsies were obtained in four subjects. Subjects had markers of severe disease, anemia, high degree of hemolysis, inflammation, and thrombophilia. The highest blood flow was present in the ulcer bed, progressively less in the immediate periwound area, and an unaffected control skin area in the same extremity. Microscopic examination showed evidence of venostasis, inflammation, and vasculopathy. Blood vessels were increased in number, had activated endothelium and evidence of thrombosis/recanalization. High blood flow may be due to chronic inflammation, cutaneous vasodilatation, venostasis, and in situ thrombosis. These changes in skin microcirculation are similar to chronic venous ulcers in the non-sickle cell disease (SCD) population, thus suggesting that leg ulcers may be another end-organ complication with endothelial dysfunction that appears in patients with SCD at a younger age and with higher frequency than in the general population.

Topical sodium nitrite for chronic leg ulcers in patients with sickle cell anaemia: a phase 1 dose-finding safety and tolerability trial.

BACKGROUND: Well-tolerated and effective treatments are needed for chronic leg ulcers in sickle cell anaemia. Topical sodium nitrite, a known nitric oxide donor, enhances blood flow in ulcers and has known bacteriostatic effects. We aimed to assess the safety, tolerability, and pharmacokinetics of topical sodium nitrite in patients with sickle cell disease and chronic leg ulcers. METHODS: We enrolled adult patients from an ambulatory clinic at the National Institutes of Health (Bethesda, MD, USA) with sickle cell anaemia with leg ulcers (with a surface area of 2.5-100 cm2) persisting for at least 4 weeks into a safety and tolerability phase 1 dose-escalation trial of topical sodium nitrite. Increasing concentrations of sodium nitrite cream were applied twice weekly for 4 weeks to one ulcer per patient at five dose levels (0.5%, 1%, 1.5%, 1.8%, and 2%). The primary endpoints were safety and tolerability, with secondary endpoints of pharmacokinetics, blood flow, and wound healing. Pain relief was analysed post hoc. Endpoints were analysed over time for the whole study population and according to dose level. This study is registered with ClinicalTrials.gov, number NCT01316796. FINDINGS: Between April 4, 2011, and March 19, 2013, we enrolled 18 adult patients with sickle cell anaemia and leg ulcers into our trial. We assigned three patients into each cohort, and each cohort was treated with a different concentration of sodium nitrite cream (cohort 1: 0.5%, cohort 2: 1.0%, cohort 3: 1.5%, and cohort 4: 2.0%). Patients were not enrolled into the next cohort dose until we were able to establish that no dose-limiting toxicities were observed. An additional six patients were enrolled to cohort 3a: 1.8%, after two patients in cohort 4 had asymptomatic drops in diastolic blood pressure. No grade 3-4 adverse events were observed, and there were no serious adverse events or dose-limiting side-effects. Pharmacokinetic analysis showed that systemic absorption of sodium nitrite was very low. Application of topical sodium nitrite was associated with a significant increase in peri-wound cutaneous blood flow measured by laser speckle contrast imaging (p=0.0002), corroborated by increased peri-wound skin temperature by infrared thermography (p=0.0119). We recorded a dose-dependent decrease in leg ulcer size (p=0.0012) and pain (p<0.0001). Ulcers healed completely in three patients who received the highest concentrations of topical sodium nitrite (the 1.8% and 2% cream). In our post-hoc analysis of pain, brief pain inventory scores improved in pain severity (p=0.0048) and pain interference (p=0.0013). INTERPRETATION: Our results indicate that topical sodium nitrite 2% cream is suitable for additional clinical trials in adults with sickle cell anaemia to promote healing of leg ulcers. FUNDING: National Heart, Lung and Blood Institute Division of Intramural Research (National Institutes of Health).

Dielectric GaAs antenna ensuring an efficient broadband coupling between an InAs quantum dot and a Gaussian optical beam.

We introduce the photonic trumpet, a dielectric structure which ensures a nearly perfect coupling between an embedded quantum light source and a Gaussian free-space beam. A photonic trumpet exploits both the broadband spontaneous emission control provided by a single-mode photonic wire and the expansion of this mode within a conical taper. Numerical simulations highlight the performance and robustness of this concept. As a first application in the field of quantum optics, we report the realization of an ultrabright single-photon source. The device, a high aspect ratio GaAs photonic trumpet containing a few InAs quantum dots, demonstrates a first-lens external efficiency of 0.75±0.1 and an external coupling efficiency to a Gaussian beam as high as 0.58±0.08.

Linearly polarized, single-mode spontaneous emission in a photonic nanowire.

We introduce dielectric elliptical photonic nanowires to funnel efficiently the spontaneous emission of an embedded emitter into a single optical mode. Inside a wire with a moderate lateral aspect ratio, the electromagnetic environment is largely dominated by a single guided mode, with a linear polarization oriented along the ellipse major axis. The resulting monomode spontaneous emission is maintained over a broad wavelength range, a key asset of this 1D photonic structure. Our theoretical analysis is completed by an experimental study of GaAs elliptical photonic wires with embedded InAs quantum dots. In particular, the fraction of collected photons with the desired linear polarization can exceed 95%.

Inhibition, enhancement, and control of spontaneous emission in photonic nanowires.

We experimentally investigate the spontaneous emission (SE) rates of single InAs quantum dots embedded in GaAs photonic nanowires. For a diameter leading to the optimal confinement of the fundamental guided mode HE11, the coupling to HE11 dominates the SE process and an increase of the SE rate by a factor of 1.5 is achieved. When the diameter is decreased, the coupling to this mode vanishes rapidly, thus allowing the coupling to the other radiation modes to be probed. In these conditions, a SE inhibition factor of 16, equivalent to the one obtained in state-of-the-art photonic crystals, is measured. These results, which are supported by fully vectorial calculations, confirm the potential of photonic nanowires for a nearly perfect, broadband SE control.

Matrix metalloproteinase-2 gene polymorphism is not associated with increased glioblastoma multiforme susceptibility: an Indian institutional experience.

BACKGROUND: Glioblastoma multiforme (GBM) is a highly malignant central nervous system tumor that is extremely refractory to therapy due to its rapid growth and local invasive potential. The ability of glioma cells to invade the surrounding tissue has been attributed to the expression of matrix metalloproteinase-2 (MMP-2) in human gliomas. The -1306C/T polymorphism in the MMP-2 gene has been found to be associated with gastric adenocarcinoma, lung cancer and various other cancers including GBM. Racial and ethnic variations are known in such genetic polymorphisms. AIMS: This prospective, case control study was aimed to find out an association of MMP-2 gene polymorphism with susceptibility to develop glioblastoma in Indian population. MATERIAL AND METHODS: MMP-2 gene polymorphism was studied using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 110 GBM patients and 150 healthy controls. The SPSS 17.0 statistical software (Chicago, IL, USA) was used for data management and analysis. RESULTS AND CONCLUSIONS: A significant association of MMP-2 (-1306C/T) polymorphism with GBM (P = 0.475) was not found, suggesting that MMP-2 (-1306C/T) polymorphism is not associated with increased GBM susceptibility.

Association of matrix metalloproteinase-1 gene polymorphism with glioblastoma multiforme in a northern Indian population.

Matrix metalloproteinase-1 (MMP-1) is known to be involved in the pathogenesis of glioma. It damages the extra-cellular matrix to produce invasiveness in cancer tissue, and hence has a direct effect in cancer invasion. The study aims to explore the association of single nucleotide polymorphism of -1607 MMP-1 gene with susceptibility to glioblastoma multiforme (GBM) in northern Indian subjects. One hundred and ten GBM patients and 150 healthy controls were included in this study. 1607 MMP-1 gene was studied by PCR-RFLP; different genotypes being combinations of 1G and 2G allele (1G/1G, 1G/2G and 2G/2G). 2G/2G genotype was significantly associated with GBM patients (OR, 2.24; P = 0.016; 95% CI, 1.16-4.30) as compared to controls. Prevalence of the 2G allele of -1607 MMP-1 polymorphism was significantly greater in GBM patients as compared to controls (62.3 vs 48.3%, OR, 1.76; P = 0.002; 95% CI, 1.23-2.52). This study suggests that the 2G/2G genotype and 2G allele of -1607 MMP-1 polymorphism are associated with an increased susceptibility for developing GBM.

An intramedullary tuberculous abscess of the conus in a 5-year-old child presenting with urinary dysfunction.

OBJECTIVE: To report a case of the primary presence of an intramedullary tuberculous abscess in the conus medullaris with neither a history of contact nor tuberculous infection elsewhere in the body. CASE DESCRIPTION: A 5-year-old boy progressed from urinary hesitancy and frequency to complete urinary retention over the course of 1 month. He was seronegative for human immunodeficiency virus. Magnetic resonance imaging (MRI) showed a D11-L1, well-circumscribed, intramedullary mass within the conus, which was hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging with a thin-walled enhancing capsule. A D11-L2 laminectomy revealed a tense dura and expanded cord with no arachnoidal adhesions. A midline myelotomy and capsular fenestration released thick yellowish, creamy pus. The histology showed loose aggregates of epithelioid cells and a mixed leukocyte population including polymorphonuclear leukocytes and mononuclear cells without formed granulomas. Ziehl-Neelsen staining showed acid-fast bacilli of Mycobacterium tuberculosis. The patient showed rapid improvement of sphincteric function with four-drug antituberculous therapy (ATT). CONCLUSIONS: To the best of the authors' knowledge, an intramedullary conus tuberculous abscess in a young child presenting with urinary dysfunction has never been reported. Perhaps hematogenous spread of M. tuberculosis within the conus, encapsulated proliferation and caseating necrosis (owing to delayed-type hypersensitivity), and an osmotic increase in the fluid content were responsible for its genesis and for the lack of arachnoidal adhesions around the cord. Surgical decompression of the abscess established the diagnosis, increased penetrability of ATT, and decreased the biologic load of bacteria, achieving a good recovery.