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Background: As a consequence of aging and the age-related cardiovascular risk, both of them closely associated to neurodegenerative diseases, dementia has become one of the major public health concerns for governments and the scientific and medical communities. Up to date, there isn’t any front-line screening tool implemented at a population level. In this regard, we aim to assess the association of several systemic biomarkers related to neuroinflammation [lactate dehydrogenase (LDH), complement component 3, C-reactive protein, alpha-1-antitrypsin, alpha-2-macroglobulin (a2M) and pancreatic prohormone], lipid metabolism [apolipoprotein E, 24S-hydroxycholesterol], and neuronal integrity [tau protein], with dementia risk in an adult-elderly population at high cardiovascular risk. Methods: We designed a case-cohort study nested in the PREDIMED cohort (110 incident cases of dementia, 251 non-cases). Participants were at high risk for cardiovascular disease (CVD), but had no clinical CVD neither dementia at the time of enrolment. Inclusion criteria were an age of 55-80 years old and the presence of diabetes type 2 or at least 3 cardiovascular risk factors (smoking, overweight or obesity, hypertension, dyslipidemia, and family history of premature CVD). We used Cox proportional hazard models to estimate hazard ratios (HR) of the association between these nine plasma biomarkers and dementia risk adjusted for several covariates. Results: Dementia cases were older, presented higher levels of fasting glucose and were more likely to have type 2 diabetes. The prevalence of dyslipidemia and smoking in patients with dementia was lower. Dementia cases had higher levels of LDH and a2M. Higher LDH levels were associated with a higher risk of developing dementia after adjustment (HR = 1.19). Conclusions: Higher LDH plasma levels are associated with a higher risk of dementia incidence in population at high cardiovascular risk. [ABSTRACT FROM AUTHOR]

We report on 8.4-GHz very-long-baseline interferometry (VLBI) observations of SN 2001gd in the spiral galaxy NGC 5033 made on 2002 June 26 (2002.48) and 2003 April 8 (2003.27). We used the interferometric visibility data to estimate angular diameter sizes for the supernova by model fitting. Our data nominally suggest a relatively strong deceleration for the expansion of SN 2001gd, but we cannot dismiss the possibility of a free supernova expansion. From our VLBI observations on 2003 April 8, we inferred a minimum total energy in relativistic particles and magnetic fields in the supernova shell of, and a corresponding equipartition average magnetic field of. We also present multiwavelength Very Large Array (VLA) measurements of SN 2001gd made at our second VLBI epoch at frequencies of 1.4, 4.9, 8.4, 15.0, 22.5 and 43.3 GHz. The VLA data are well fitted by an optically thin, synchrotron spectrum, partially absorbed by thermal plasma. We obtain a supernova flux density of at the observing frequency of 8.4 GHz for the second epoch, which results in an isotropic radio luminosity of between 1.4 and 43.3 GHz, at an adopted distance of 13.1 Mpc. Finally, we report on an XMM–Newton X-ray detection of SN 2001gd on 2002 December 18. The supernova X-ray spectrum is consistent with optically thin emission from a soft component (associated with emission from the reverse shock) at a temperature of around 1 keV. The observed flux corresponds to an isotropic X-ray luminosity of in the 0.3–5 keV band. We suggest that both radio and X-ray observations of SN 2001gd indicate that a circumstellar interaction similar to that displayed by SN 1993J in M 81 is taking place. [ABSTRACT FROM AUTHOR]

We report here on 5-GHz global very-long-baseline interferometry (VLBI) observations of SN 1986J, 16 yr after its explosion. We obtained a high-resolution image of the supernova, which shows a distorted shell of radio emission, indicative of a deformation of the shock front. The angular size of the shell is ∼4.7 mas, corresponding to a linear size of ∼6.8 × 10[sup 17] cm for a distance of 9.6 Mpc to NGC 891. The average speed of the shell has decreased from ∼ 7400 km s[sup -1] in 1988.74 down to about 6300 km s[sup -1] in 1999.14, indicative of a mild deceleration in the expansion of SN 1986J. Assuming a standard density profile for the progenitor wind (ρ[sub cs] ∝ r[sup -s], s = 2), the swept-up mass by the shock front is ∼2.2 M.... This large swept-up mass, coupled with the mild deceleration suffered by the supernova, suggests that the mass of the hydrogen-rich envelope ejected at explosion was ...12 M.... Thus, the supernova progenitor must have kept intact most of its hydrogen-rich envelope by the time of explosion, which favours a single, massive star progenitor scenario. We find a flux density for SN 1986J of ∼ 7.2 mJy at the observing frequency of 5 GHz, which results in a radio luminosity of ∼1.4 × 10[sup 37] erg s[sup -1] for the frequency range 10[sup 7]-10[sup 10] Hz (α = -0.69; S[sub v] ∝ v[sup α]). We detect four bright knots that delineate the shell structure, and an absolute minimum of emission, which we tentatively identify with the centre of the supernova explosion. If this is the case, SN 1986J has then suffered an asymmetric expansion. We suggest that this asymmetry is due to the collision of the supernova ejecta with an anisotropic, clumpy (or filamentary) medium. [ABSTRACT FROM AUTHOR]