The development of the sympathetic system of the heart

Development of the sympathetic nervous system begins at about embryonic day 9 in mice with the migration of the neural crest cells to the dorsal aorta and the development of neurons and the sympathetic ganglia. This is followed by the axonal elongation towards the developing cardiac tissue. This process is directed by a series of signal ligands including ephrin-B1, semaphorin 3a (Sema3a), F-Spondin, bone morphogenetic proteins (BMPs), Wnt-1 protein, neurotrophin-3 (NT-3), nerve growth factor (NGF) and artemin (ARTN). Once at the developing heart, the nerve fibres follow the coronary veins in the subepicardium using NGF and the chemorepellent Sema3a as signals. Here they interact with the cardiac conduction system. Although these cardiac neural cells are part of the autonomic system, they are developed later, mainly on the epicardial surface. Bilateral innervation of the heart comes from the middle cervical stellate (MC-S) ganglion. Although the left ventricle and atrium receive noradrenaline from the MC-S on both sides, the right ventricle receives more from the MC-S from the left rather than from the right side. The development of the great vessels also contributes towards the pattern of development of cardiac innervation. The afferent fibres leaving the heart are also described. Their development relates to the sympathetic innervation of the heart and therefore to cardiac sensations. We hypothesise about how this reflects on the patterns of ischaemic cardiac pain.peer-reviewe

Prevalence of obesity in Malta

Background: Obesity is a global epidemic with the Mediterranean island of Malta being no exception. The World Health Organization (WHO) has identified Malta as one of the European countries with the highest obesity prevalence. Method: A cross-sectional study was conducted (2014–2016) under the auspices of the University of Malta. The prevalence of overweight-obesity in Malta was calculated and then age stratified for comparisons with previous studies. Results: The study identified 69.75% (95% CI: 68.32–71.18) of the Maltese population to be either overweight or obese. The men overweight/obese prevalence (76.28% 95% CI: 74.41–78.14) was statistically higher than that for women (63.06% 95% CI: 60.92–65.20) (p = 0.0001). Age stratification revealed that both genders had the highest overweight prevalence rates between 55 and 64 years (Men = 23.25% 95% CI: 20.43–26.33; Women = 24.68% 95% CI: 21.44–28.22). Men obesity prevalence rates were highest in the 35 to 44 years group (22.52% 95% CI: 19.65–25.68) while for women it was highest in the 55 to 64 years group (28.90%, 95% CI: 25.44–30.63). Conclusion: Over a 35-year period, an overall decrease in the normal and overweight BMI categories occurred with an increase in the prevalence of obesity. An exception was observed in the women, where the prevalence of normal BMI increased over this time period. Also, it appears that while the total population obesity prevalence increased (for 2016), a percentage of the women have shifted from an obese to an overweight status.peer-reviewe

NetMatchStar: an enhanced Cytoscape network querying app [version 1; referees: 2 approved]

We present NetMatchStar, a Cytoscape app to find all the occurrences of a query graph in a network and check for its significance as a motif with respect to seven different random models. The query can be uploaded or built from scratch using Cytoscape facilities. The app significantly enhances the previous NetMatch in style, performance and functionality. Notably NetMatchStar allows queries with wildcards

NetMatchStar: an enhanced Cytoscape network querying app [version 2; referees: 2 approved]

We present NetMatchStar, a Cytoscape app to find all the occurrences of a query graph in a network and check for its significance as a motif with respect to seven different random models. The query can be uploaded or built from scratch using Cytoscape facilities. The app significantly enhances the previous NetMatch in style, performance and functionality. Notably NetMatchStar allows queries with wildcards