Peptidergic control in a fruit crop pest: The spotted-wing drosophila, Drosophila suzukii

Neuropeptides play an important role in the regulation of feeding in insects and offer potential targets for the development of new chemicals to control insect pests. A pest that has attracted much recent attention is the highly invasive Drosophila suzukii, a polyphagous pest that can cause serious economic damage to soft fruits. Previously we showed by mass spectrometry the presence of the neuropeptide myosuppressin (TDVDHVFLRFamide) in the nerve bundle suggesting that this peptide is involved in regulating the function of the crop, which in adult dipteran insects has important roles in the processing of food, the storage of carbohydrates and the movement of food into the midgut for digestion. In the present study antibodies that recognise the C-terminal RFamide epitope of myosuppressin stain axons in the crop nerve bundle and reveal peptidergic fibres covering the surface of the crop. We also show using an in vitro bioassay that the neuropeptide is a potent inhibitor (EC50 of 2.3 nM) of crop contractions and that this inhibition is mimicked by the non-peptide myosuppressin agonist, benzethonium chloride (Bztc). Myosuppressin also inhibited the peristaltic contractions of the adult midgut, but was a much weaker agonist (EC50 = 5.7 μM). The oral administration of Bztc (5 mM) in a sucrose diet to adult female D. suzukii over 4 hours resulted in less feeding and longer exposure to dietary Bztc led to early mortality. We therefore suggest that myosuppressin and its cognate receptors are potential targets for disrupting feeding behaviour of adult D. suzukii

Vitamin D in health and disease: Current perspectives

Despite the numerous reports of the association of vitamin D with a spectrum of development, disease treatment and health maintenance, vitamin D deficiency is common. Originating in part from the diet but with a key source resulting from transformation by exposure to sunshine, a great deal of the population suffers from vitamin D deficiency especially during winter months. It is linked to the treatment and pathogenesis and/or progression of several disorders including cancer, hypertension, multiple sclerosis, rheumatoid arthritis, osteoporosis, muscle weakness and diabetes. This widespread deficiency of Vitamin D merits consideration of widespread policies including increasing awareness among the public and healthcare professionals

Critical race theory as theoretical framework and analysis tool for population health research

In population health research, it is important to consider socioecological perspectives that include cultural attitudes and beliefs which permeate all levels (intrapersonal, interpersonal, institutional/community, and structural/ policy). Given the specificity of target populations centered on identity – ethnic and others – it is appropriate and warranted to centralize cultural studies theories into health determinant investigations. Cultural studies, which focus explicitly on identity exploration and impacts, have much to contribute to health research. In accordance with the transdisciplinary nature of population health and bearing in mind the significant role of ethnic identity in health outcomes, it is beneficial to utilize critical race theory (CRT) as a theoretical framework and analysis tool for population health research. This article will: (1) briefly overview a recent mental health study employing CRT, and a commentary that emphasizes how CRT can contribute to the sociology of mental health; and (2) propose ways CRT can be used in psychosocial health research

Longitudinal PET-MRI reveals beta-amyloid deposition and rCBF dynamics and connects vascular amyloidosis to quantitative loss of perfusion

The dynamics of beta-amyloid deposition and related second-order physiological effects, such as regional cerebral blood flow (rCBF), are key factors for a deeper understanding of Alzheimer's disease (AD). We present longitudinal in vivo data on the dynamics of beta-amyloid deposition and the decline of rCBF in two different amyloid precursor protein (APP) transgenic mouse models of AD. Using a multiparametric positron emission tomography and magnetic resonance imaging approach, we demonstrate that in the presence of cerebral beta-amyloid angiopathy (CAA), beta-amyloid deposition is accompanied by a decline of rCBF. Loss of perfusion correlates with the growth of beta-amyloid plaque burden but is not related to the number of CAA-induced microhemorrhages. However, in a mouse model of parenchymal beta-amyloidosis and negligible CAA, rCBF is unchanged. Because synaptically driven spontaneous network activity is similar in both transgenic mouse strains, we conclude that the disease-related decline of rCBF is caused by CA