Search

Background: Studies have observed higher incidence of cardiovascular mortality in South Asians (SA), and lower prevalence in East Asians (EA), compared with Caucasians. These observations are not entirely explained by ethnic differences in cardiovascular risk factors and mechanistic factors such as variations in cardiac anatomy and physiology may play a role. This study compared ethnic differences in CT-assessed left ventricular (LV) mass, coronary anatomy and non-invasive fractional flow reserve (FFRCT). Method(s): Three-hundred symptomatic patients (age 59 +/- 7.9, male 51%) underwent clinically-mandated CT-coronary-angiography (CTA) were matched for age, gender, BMI and diabetes (100 each ethnicity). Assessment of coronary stenosis, luminal dimensions and vessel dominance was performed by independent observers. LV mass, coronary luminal volume and FFRCT were quantified by blinded core-laboratory. A sub-analysis was performed on patients (n = 187) with normal/minimal disease (0-25% stenosis). Result(s): Stenosis severity was comparable across ethnic groups. EA demonstrated less left-dominant circulation (2%) compared with SA (8.2%) and Caucasians (10.1%). SA compared with EA and Caucasians demonstrated smallest indexed LV mass, coronary luminal volumes and dimensions. EA compared with Caucasians had comparable indexed LV mass, coronary luminal dimensions and highest luminal volumes. The latter was driven by higher prevalence of right-dominance including larger and longer right posterior left ventricular artery. FFRCT in the left anterior descending artery (LAD) was lowest in SA (0.87) compared with EA (0.89; P = 0.009) and Caucasians (0.89; P < 0.001), with no difference in other vessels. All observed differences were consistent in patients with minimal disease. Conclusion(s): This single-centre study identified significant ethnic differences in CT-assessed LV mass, coronary anatomy and LAD FFRCT. These hypotheses generating results may provide a mechanistic expla

Purpose: South Asian (SA) have been observed to have higher cardiovascular mortality rates compared to East Asians (EA) and Caucasians. Pericoronary adipose tissue (PCAT) attenuation around the right coronary artery (RCA) from coronary CT angiography (CTA) has been associated with coronary inflammation and cardiac death. We aimed to investigate i) the relationship between plaque characteristics and PCAT attenuation and ii) to assess gender and ethnic differences in PCAT attenuation using a matched cohort of SA, EA and Caucasians. Method(s): Three-hundred symptomatic patients who underwent CTA were matched for age, gender, BMI and diabetes (100 in each ethnic group). Semi-automated software was used to quantify the total volumes and burden of non-calcified plaque (NCP), low-density non-calcified plaque (LD-NCP) and calcified plaque (CP) in blinded core-lab analysis. PCAT CT attenuation was measured around the RCA (10-50 mm from RCA ostium), the most standardized model for PCAT analysis. Result(s): The total volumes and burden of NCP, LD-NCP and CP were comparable in the ethnic groups (each p > 0.05). PCAT attenuation was higher in patients with coronary plaque. PCAT attenuation correlated with the total volumes and burden of NCP, LD-NCP and CP (r>0.17; p < 0.003). Within the RCA this correlation persisted only for NCP features (r>0.39;p < 0.001). Males showed higher PCAT attenuation (p < 0.001). PCAT attenuation was similar between Caucasian, EA and SA (p = 0.32). Conclusion(s): PCAT CT attenuation correlated most with its surrounded NCP features further highlighting its role as surrogate measure of coronary inflammation. As coronary plaque burden and RCA PCAT attenuation did not differ between ethnic groups, causes of increased cardiac mortality in South Asians needs further investigations.Copyright © 2020

Background: When compared with Caucasian populations, East Asians (EA) have a lower prevalence of coronary artery disease, myocardial infarction and cardiovascular mortality. Ethnic differences in coronary atherosclerotic burden and plaque composition are not known. Objective(s): To compare CT-assessed coronary atherosclerotic burden, plaque composition and quantitative high risk plaque features in a matched cohort of Caucasian and EA patients with stable chest pain. Method(s): Two-hundred symptomatic patients (age 58.8+/-7.9, male 51%) underwent clinically mandated CT coronary angiography (CTA) were matched for age, gender, BMI and diabetes (100 for each ethnic group). Visual CTA assessment and quantitative plaque analysis using dedicated semiautomatic software was performed by a blinded core laboratory to measure plaque volume and burden. Plaque composition was determined from measurement of total, calcified and non-calcified plaque (NCP) volumes. NCP was further separated by differences in Hounsfield Units (HU). Quantitative high risk plaque features were defined as low attenuation necrotic core (-30 to 30 HU) and intermediate fibrofatty plaque (31-130 HU). Favourable plaque was defined as high attenuation fibrous plaque (131-350 HU). Result(s): Segment Involvement Score, percent diameter and area stenosis were comparable in both groups. Similarly, there was no significant difference in total plaque, calcified and non-calcified plaque volume and burden. Compared with Caucasians, plaque composition in East Asians was associated with significantly less high risk features of necrotic core (3.47 vs 5.09%, P=0.003) and fibrofatty plaque (29.28 vs 37.20% P=0.002). Fibrous plaque composition was highest in East Asians (65.65 vs 57.58% P=0.009). Conclusion(s): Based on this matched cohort with comparable overall plaque volume and burden, East Asians exhibited significantly lower composition of high risk plaque features and had higher favourable plaque composition compare

Recent evidence suggests plaque morphology evaluated on coronary computed tomography angiography has prognostic implications. East Asians have a lower prevalence of myocardial infarction and cardiovascular mortality compared with European-origin Caucasians. We aimed to compare coronary atherosclerotic burden and plaque composition in a matched cohort of Caucasian and East Asians patients with stable chest pain who underwent computed tomography angiography. Two-hundred symptomatic patients (age 58.8 +/- 7.9, male 51%) were matched for age, gender, body mass index, and diabetes (100 each ethnic group). A blinded core-laboratory quantified calcified and noncalcified plaque (NCP) volume and burden. Components of NCP were differentiated by plaque hounsfield unit (HU) thresholds which defined high-risk necrotic core (-30 to 30HU), fibrofatty plaque (31 to 130HU); and low-risk fibrous plaque (131 to 350HU). Composition of NCP components was derived as (NCP component volume/total NCP volume) x 100%. Segment Involvement Score, percent diameter and area stenosis were comparable in both groups. Similarly, there was no difference in the volume and burden of total, calcified and NCP. Compared with Caucasians, East Asians demonstrated lower composition of plaque attenuation corresponding to necrotic core (3.5 vs 5.1%; p = 0.004) and fibrofatty plaque (29.6 vs 37.3%; p = 0.005), and higher fibrous plaque (65.7 vs 57.6%; p = 0.004). On multivariable analysis East Asian ethnicity was independently associated with lower composition of high-risk plaque after adjustment for risk factors and scan parameters. These findings were consistent in a propensity-matched sensitivity-analysis. In conclusion, based on this matched cohort, East Asian ethnicity is associated with significantly less composition of high-risk NCP (necrotic core and fibrofatty plaque) and a higher composition of low-risk fibrous plaque compared with Caucasians; which may confer a lower risk of cardiovascular events.Copy

Bats are important reservoirs and vectors in the transmission of emerging infectious diseases. Many highly pathogenic viruses such as SARS-CoV and rabies-related lyssaviruses have crossed species barriers to infect humans and other animals. In this study we monitored the major roost sites of bats in Singapore, and performed surveillance for zoonotic pathogens in these bats. Screening of guano samples collected during the survey uncovered a bat coronavirus (Betacoronavirus) in Cynopterus brachyotis, commonly known as the lesser dog-faced fruit bat. Using a capture-enrichment sequencing platform, the full-length genome of the bat CoV was sequenced and found to be closely related to the bat coronavirus HKU9 species found in Leschenault's rousette discovered in the Guangdong and Yunnan provinces.

© 2017 The Author(s). Macrophages are potent immune cells with well-established roles in the response to stress, injury, infection and inflammation. The classically activated macrophages (M1) are induced by lipopolysaccharide (LPS) and express a wide range of pro-inflammatory genes. M2 macrophages are induced by T helper type 2 cytokines such as interleukin-4 (IL4) and express high levels of anti-inflammatory and tissue repair genes. The strong association between macrophages and tumour cells as well as the high incidences of leukocyte infiltration in solid tumours have contributed to the discovery that tumour-associated macrophages (TAMs) are key to tumour progression. Here, we investigated the role of Annexin A1 (ANXA1), a well characterized immunomodulatory protein on macrophage polarization and the interaction between macrophages and breast cancer cells. Our results demonstrate that ANXA1 regulates macrophage polarization and activation. ANXA1 can act dually as an endogenous signalling molecule or as a secreted mediator which acts via its receptor, FPR2, to promote macrophage polarization. Furthermore, ANXA1 deficient mice exhibit reduced tumour growth and enhanced survival in vivo, possibly due to increased M1 macrophages within the tumor microenvironment. These results provide new insights into the molecular mechanisms of macrophage polarization with therapeutic potential to suppress breast cancer growth and metastasis.

Commensal plants and animals have long been used to track human migrations, with Rattus exulans (the Pacific rat) a common organism for reconstructing Polynesian dispersal in the Pacific. However, with no knowledge of the homeland of R. exulans, the place of origin of this human-commensal relationship is unknown. We conducted a mitochondrial DNA phylogeographic survey of R. exulans diversity across the potential natural range in mainland and Island Southeast Asia in order to establish the origin of this human-commensal dyad. We also conducted allozyme electrophoresis on samples from ISEA to obtain a perspective on patterns of genetic diversity in this critical region. Finally, we compared molecular genetic evidence with knowledge of prehistoric rodent faunas in mainland and ISEA. We find that ISEA populations of R. exulans contain the highest mtDNA lineage diversity including significant haplotype diversity not represented elsewhere in the species range. Within ISEA, the island of Flores in the Lesser Sunda group contains the highest diversity in ISEA (across all loci) and also has a deep fossil record of small mammals that appears to include R. exulans. Therefore, in addition to Flores harboring unusual diversity in the form of Homo floresiensis, dwarfed stegodons and giant rats, this island appears to be the homeland of R. exulans.

A low-resolution X-ray molecular structure of the title hydrated salt, [Na(C19H21N6O6)]·2H 2O, displays scorpionate character and resolves apparent ambiguities between solution and solid-state NMR spectroscopies. The 13C NMR CPMAS spectrum is consistent with this structure showing some splittings, which have been rationalized using GIAO/B3LYP/6-311++G(d,p) theoretical calculations. © 2013 International Union of Crystallography.

Crystallographic and solid CPMAS NMR studies were performed on the (4S,7R)-enantiomer as well as on the (4S,7R)- and (4R,7S)-7,8,8-trimethyl-4,5,6,7-tetrahydro-4,7-methano-2H-indazole racemate. Both crystallize with six independent molecules forming two trimers. Assignment of the 13C chemical shifts to the six molecules, slighting differing in geometry, was carried out by comparison with GIAO/B3LYP/6-31G(d) calculations. © 2009 Elsevier B.V. All rights reserved.

The tautomerism in the solid state and in solution of five 4-bromo-1H-pyrazoles has been studied by multinuclear magnetic resonance spectroscopy and, for one of them, by X-ray crystallography (3,4-dibromo-5-phenyl-1H-pyrazole). When there is a bromine atom at position 3(5), in all cases, the tautomer present in the solid state is the 3-bromo one. In solution, the same tautomer is the major one. DFT calculations justify the predominance of 3-bromo tautomers over 5-bromo ones and provide some useful chemical shifts obtained through GIAO calculations. © 2007 Elsevier Ltd. All rights reserved.

The structure of the title compound serves for a discussion about the topic of orthogonal interactions. This interaction, although weak, is important due to its peculiar geometry. Other examples from the Cambridge Crystallographic Database, together with theoretical calculations are reported. © CSIRI 2005.

1-Hydroxymethylindazole and 1-hydroxymethylbenzotriazole have been studied in solution by 1H, 13C and 15N NMR spectroscopy and the X-ray structure of the second compound determined. DFT and GIAO calculations have been used to discuss geometries, energies (comparatively with 2-substituted isomers) and NMR chemical shifts.

Reaction of (Me3SiCH2)3Al with E(SiMe3)3 (E = P, As) in a 1:1 mole ratio affords the Lewis acid-base adducts (Me3SiCH2)3Al.P(SiMe3)3 (1) and (Me3SiCH2)3Al.As(SiMe3)3 (2). Similarly, the 1:1 mole ratio reaction of (Me3CCH2)3Al with E(SiMe3)3 (E = P, As) leads to the isolation of (Me3CCH2)3Al.P(SiMe3)3 (3) and (Me3CCH2)3Al.As(SiMe3)3 (4). The adduct (Me3SiCH2)2(Br)Al.P(SiMe3)3 (5) was obtained from the 1:1 mole ratio reaction of (Me3SiCH2)2AlBr with P(SiMe3)3. The dimers (Me3SiCH2)(Br)AlP(SiMe3)22 (6) and (Me3SiCH2)(Br)AlAs(SiMe3)22 (7) were isolated as products of the lithium halide elimination reactions of (Me3SiCH2)AlBr2 (10) with LiE(SiMe3)2 (E = P, As), while reaction of (Me3SiCH2)2AlBr with these same lithium pnictide salts leads to the isolation of (Me3SiCH2)2AlP(SiMe3)22 (8) and (Me3SiCH2)2AlAs(SiMe3)22 (9). Various physical and spectroscopic data, including a variable temperature NMR study of the dimeric compounds 6 through 9, are presented for the above compounds, as are the single crystal X-ray structures of 2 through 7 and 9., Prepared in collaboration with University of Delaware, Dept. of Chemistry, Newark, DE; University of North Carolina at Chapel Hill, Dept. of Chemistry, Chapel Hill, NC. Accepted for publication in Organometallics.