Endovascular management of mycotic aortic aneurysms- A 20-year experience from a single UK centre.

AIM: To present the authors' experience of endovascular treatment of confirmed and presumed (microbiology negative) mycotic aortic aneurysms (MAA). MATERIALS AND METHODS: Patients undergoing endovascular aortic repair were identified retrospectively from 1998 using the radiology information system and an internally kept database until 2018. The primary aim was to assess the technical success and peri-operative morbidity and mortality. The secondary aim was to assess progression of infection, re-interventions, late mortality, and correlation to antibiotic duration pre- and post-procedure. RESULTS: Thirty-four endovascular aortic procedures were performed for MAA, excluding aorto-enteric fistulas, inflammatory aneurysms, and infected grafts without a new aneurysm. Seventy-six percent of these were thoracic and 24% abdominal. The technical success was 100%. Additional procedures were undertaken in four patients with two requiring a further endovascular procedure. There were two inpatient aneurysm-related mortalities and no inpatient conversions to open repair. The 30-day re-admission and re-intervention rate was 0%. Blood cultures were positive in 45%. There were no secondary graft infections. CONCLUSION: This is the largest European single-centre study. It supports endovascular management of MAA as a lower-risk alternative to open surgery with the majority of patients presenting acutely, later in life and requiring emergency management.

Numerical simulations of different sectoral contributions to post monsoon pollution over Delhi.

The National Capital Region (NCR) of India, Delhi, has experienced high post-monsoon pollution along with several peak pollution episodes in recent years. Diwali, the festival of lights, which is among the biggest festivals of India celebrated during the post-monsoon season, is also considered a pollution event associated as it is with the lighting of a large number of firecrackers. 2016 Diwali pollution episode continued for a week creating severe discomfort to residents of Delhi, prompting the judiciary to ban the sale and use of firecrackers in Delhi from 2017 onwards. The current study analyzes different sectoral and temporal emissions contribution to the 2016 post monsoonal pollution episode over Delhi using a fully coupled chemical transport model. The findings of the study indicate that aerosols produced from crop residue open burning at the northwestern states contributed more than 60% of the total simulated surface concentration during the period under study. Model experimental simulations show that despite emissions from within the city, what explains the severity of pollution over Delhi during the period under consideration is an additional pollution load emanating from these intense crop open burning sessions from nearby areas. Further, model simulations show that while Diwali emissions can elevate the pollution load over Delhi, the effects do not last beyond 48 h. It is found that the stagnation of the pollutants several days beyond the 2016 Diwali day was due to favorable meteorological conditions like low surface temperature, lower boundary layer height, and weak northwesterly winds. The study shows that in order to improve air quality in Delhi during the post-monsoon period, mitigation efforts should target the adjacent rural areas, especially when there is massive burning of crop residue in those areas.

Black carbon solar absorption suppresses turbulence in the atmospheric boundary layer.

The introduction of cloud condensation nuclei and radiative heating by sunlight-absorbing aerosols can modify the thickness and coverage of low clouds, yielding significant radiative forcing of climate. The magnitude and sign of changes in cloud coverage and depth in response to changing aerosols are impacted by turbulent dynamics of the cloudy atmosphere, but integrated measurements of aerosol solar absorption and turbulent fluxes have not been reported thus far. Here we report such integrated measurements made from unmanned aerial vehicles (UAVs) during the CARDEX (Cloud Aerosol Radiative Forcing and Dynamics Experiment) investigation conducted over the northern Indian Ocean. The UAV and surface data reveal a reduction in turbulent kinetic energy in the surface mixed layer at the base of the atmosphere concurrent with an increase in absorbing black carbon aerosols. Polluted conditions coincide with a warmer and shallower surface mixed layer because of aerosol radiative heating and reduced turbulence. The polluted surface mixed layer was also observed to be more humid with higher relative humidity. Greater humidity enhances cloud development, as evidenced by polluted clouds that penetrate higher above the top of the surface mixed layer. Reduced entrainment of dry air into the surface layer from above the inversion capping the surface mixed layer, due to weaker turbulence, may contribute to higher relative humidity in the surface layer during polluted conditions. Measurements of turbulence are important for studies of aerosol effects on clouds. Moreover, reduced turbulence can exacerbate both the human health impacts of high concentrations of fine particles and conditions favorable for low-visibility fog events.

Metabolites as novel biomarkers for childhood obesity-related traits in Mexican-American children.

BACKGROUND/OBJECTIVES: Although newer approaches have identified several metabolites associated with obesity, there is paucity of such information in paediatric populations, especially among Mexican-Americans (MAs) who are at high risk of obesity. Therefore, we performed a global serum metabolite screening in MA children to identify biomarkers of childhood obesity. METHODS: We selected 15 normal-weight, 13 overweight and 14 obese MA children (6-17 years) and performed global serum metabolite screening using ultra-performance liquid chromatography/quadruple orthogonal acceleration time of flight tandem micro mass spectrometer. Metabolite values were analysed to assess mean differences among groups using one-way analysis of variance, to test for linear trend across groups and to examine Pearson's correlations between them and seven cardiometabolic traits (CMTs): body mass index, waist circumference, systolic blood pressure, diastolic blood pressure, homeostasis model of assessment-insulin resistance, triglycerides and high-density lipoprotein cholesterol. RESULTS: We identified 14 metabolites exhibiting differences between groups as well as linear trend across groups with nominal statistical significance. After adjustment for multiple testing, mean differences and linear trends across groups remained significant (P < 5.9 × 10(-5) ) for L-thyronine, bradykinin and naringenin. Of the examined metabolite-CMT trait pairs, all metabolites except for 2-methylbutyroylcarnitine were nominally associated with two or more CMTs, some exhibiting significance even after accounting for multiple testing (P < 3.6 × 10(-3) ). CONCLUSIONS: To our knowledge, this study - albeit pilot in nature - is the first study to identify these metabolites as novel biomarkers of childhood obesity and its correlates. These findings signify the need for future systematic investigations of metabolic pathways underlying childhood obesity.

Localization of a major susceptibility locus influencing preterm birth.

Preterm birth (PTB) is a complex trait, but little is known regarding its major genetic determinants. The objective of this study is to localize genes that influence susceptibility to PTB in Mexican Americans (MAs), a minority population in the USA, using predominantly microfilmed birth certificate-based data obtained from the San Antonio Family Birth Weight Study. Only 1302 singleton births from 288 families with information on PTB and significant covariates were considered for genetic analysis. PTB is defined as a childbirth that occurs at <37 completed weeks of gestation, and the prevalence of PTB in this sample was 6.4%. An ∼10 cM genetic map was used to conduct a genome-wide linkage analysis using the program SOLAR. The heritability of PTB was high (h(2) ± SE: 0.75 ± 0.20) and significant (P = 4.5 × 10(-5)), after adjusting for the significant effects of birthweight and birth order. We found significant evidence for linkage of PTB (LOD = 3.6; nominal P = 2.3 × 10(-5); empirical P = 1.0 × 10(-5)) on chromosome 18q between markers D18S1364 and D18S541. Several other chromosomal regions (2q, 9p, 16q and 20q) were also potentially linked with PTB. A strong positional candidate gene in the 18q linked region is SERPINB2 or PAI-2, a member of the plasminogen activator system that is associated with various reproductive processes. In conclusion, to our knowledge, perhaps for the first time in MAs or US populations, we have localized a major susceptibility locus for PTB on chromosome 18q21.33-q23.

Solar absorption by elemental and brown carbon determined from spectral observations.

Black carbon (BC) is functionally defined as the absorbing component of atmospheric total carbonaceous aerosols (TC) and is typically dominated by soot-like elemental carbon (EC). However, organic carbon (OC) has also been shown to absorb strongly at visible to UV wavelengths and the absorbing organics are referred to as brown carbon (BrC), which is typically not represented in climate models. We propose an observationally based analytical method for rigorously partitioning measured absorption aerosol optical depths (AAOD) and single scattering albedo (SSA) among EC and BrC, using multiwavelength measurements of total (EC, OC, and dust) absorption. EC is found to be strongly absorbing (SSA of 0.38) whereas the BrC SSA varies globally between 0.77 and 0.85. The method is applied to the California region. We find TC (EC + BrC) contributes 81% of the total absorption at 675 nm and 84% at 440 nm. The BrC absorption at 440 nm is about 40% of the EC, whereas at 675 nm it is less than 10% of EC. We find an enhanced absorption due to OC in the summer months and in southern California (related to forest fires and secondary OC). The fractions and trends are broadly consistent with aerosol chemical-transport models as well as with regional emission inventories, implying that we have obtained a representative estimate for BrC absorption. The results demonstrate that current climate models that treat OC as nonabsorbing are underestimating the total warming effect of carbonaceous aerosols by neglecting part of the atmospheric heating, particularly over biomass-burning regions that emit BrC.

Real-time assessment of black carbon pollution in Indian households due to traditional and improved biomass cookstoves.

Use of improved (biomass) cookstoves (ICs) has been widely proposed as a Black Carbon (BC) mitigation measure with significant climate and health benefits. ICs encompass a range of technologies, including natural draft (ND) stoves, which feature structural modifications to enhance air flow, and forced draft (FD) stoves, which additionally employ an external fan to force air into the combustion chamber. We present here, under Project Surya, the first real-time in situ Black Carbon (BC) concentration measurements from five commercial ICs and a traditional (mud) cookstove for comparison. These experiments reveal four significant findings about the tested stoves. First, FD stoves emerge as the superior IC technology, reducing plume zone BC concentration by a factor of 4 (compared to 1.5 for ND). Indoor cooking-time BC concentrations, which varied from 50 to 1000 µg m(-3) for the traditional mud cookstove, were reduced to 5-100 µg m(-3) by the top-performing FD stove. Second, BC reductions from IC models in the same technology category vary significantly: for example, some ND models occasionally emit more BC than a traditional cookstove. Within the ND class, only microgasification stoves were effective in reducing BC. Third, BC concentration varies significantly for repeated cooking cycles with same stove (standard deviation up to 50% of mean concentration) even in a standardized setup, highlighting inherent uncertainties in cookstove performance. Fourth, use of mixed fuel (reflective of local practices) increases plume zone BC concentration (compared to hardwood) by a factor of 2 to 3 across ICs.

Femoral artery dissection in vascular type Ehlers-Danlos syndrome; leave well alone?

Vascular Ehlers-Danlos Syndrome (EDS) is a rare autosomal dominant condition resulting from a defect in type III procollagen synthesis. This causes the development of severe vascular pathologies, including arterial rupture and pseudoaneurysm formation. We present a case of a young boy previously diagnosed with vascular EDS due to a Gly975Val substitution in the collagen α1(III) chain presenting with a common femoral artery dissection secondary to minimal trauma. This was managed conservatively with serial duplex scans and gentle mobilization. At follow up the patient had returned to normal activities, with MRA and duplex scans showing complete resolution of the dissection.

Acute gastrointestinal haemorrhage: the role of the radiologist.

Acute gastrointestinal (GI) haemorrhage is a frequent and potentially life threatening medical presentation, the management of which depends on more than one speciality. Upper GI haemorrhage is often treated by endoscopic methods, failing which radiological intervention or surgery are the alternative methods of treatment. Radiology is crucial both in the diagnosis and treatment of lower GI haemorrhage, where the role of endoscopy is limited by poor visibility. CT angiography is now the first line investigation of choice and catheter angiography is used as a prelude to intervention. Interventional radiological techniques for treatment include embolisation for both upper and lower GI arterial haemorrhage and transjugular intrahepatic portosystemic shunting for upper GI variceal haemorrhage refractory to endoscopic treatment.

Primary cardiac angiosarcoma arising from the interatrial septum: magnetic resonance imaging appearances.

We present a case of primary cardiac angiosarcoma arising from the interatrial septum that had imaging features overlapping with those of right atrial myxoma. The mass was initially discovered on a thoracic CT study. Further evaluation with echocardiography was limited by poor acoustic windows and cardiac magnetic resonance (CMR) imaging was performed prior to surgical resection. CMR provided a detailed morphological assessment; imaging features included a frond-like surface architecture, a narrow attachment point at the interatrial septum, mild signal hyperintensity compared with that of myocardium on T(1) weighted sequences, patchy foci of delayed gadolinium enhancement and a haemorrhagic pericardial effusion. To the best of our knowledge, this is the first reported case of angiosarcoma arising from the interatrial septum that has undergone evaluation with CMR.

MRI and CT appearances of cardiac tumours in adults.

Primary cardiac tumours are rare, and metastases to the heart are much more frequent. Myxoma is the commonest benign primary tumour and sarcomas account for the majority of malignant lesions. Clinical manifestations are diverse, non-specific, and governed by the location, size, and aggressiveness. Imaging plays a central role in their evaluation, and familiarity with characteristic features is essential to generate a meaningful differential diagnosis. Cardiac magnetic resonance imaging (MRI) has become the reference technique for evaluation of a suspected cardiac mass. Computed tomography (CT) provides complementary information and, with the advent of electrocardiographic gating, has become a powerful tool in its own right for cardiac morphological assessment. This paper reviews the MRI and CT features of primary and secondary cardiac malignancy. Important differential considerations and potential diagnostic pitfalls are also highlighted.