Resolving the cognitive clinico-radiological paradox - Microstructural degeneration of fronto-striatal-thalamic loops in early active multiple sclerosis.

BACKGROUND: Associations between cognitive impairment (CI) and both global and regional brain volumes can be weak in early multiple sclerosis (MS), a dilemma known as cognitive clinico-radiological paradox. We hypothesized that white-matter (WM) integrity within fronto-striatal-thalamic networks may be a sensitive marker for impaired performance in speed-dependent tasks, typical for early MS. METHODS: Twenty-seven patients with early active relapsing-remitting MS (RRMS) received comprehensive neuropsychological assessment and underwent structural and diffusion-weighted brain magnetic resonance imaging (MRI). Global and regional brain volumes were obtained using FreeSurfer software. Fractional anisotropy (FA) was computed from diffusion tensor images to assess microstructural alterations within three anatomically predefined fronto-striatal-thalamic loops known to be relevant for speed-dependent attention and executive functions. RESULTS: Overall cognitive performance (Spearman's ρ = .51) and performance in the domains processing speed (ρ = .44) and executive functions (ρ = .41) were correlated with patients' mean FA within the right dorsolateral-prefrontal loop. In addition, overall cognitive performance correlated with mean FA within the right lateral orbitofrontal loop (ρ = .39) - but only before controlling for WM lesion count. In contrast, regional volumes of grey-matter structures within these fronto-striatal-thalamic loops (including the thalamus) were not significantly related to CI. The total brain volume was associated with performance in the domain verbal memory (ρ = .43) only. CONCLUSIONS: Microstructural degeneration within specific fronto-striatal-thalamic WM networks, previously characterized as crucial for task-monitoring, better accounts for speed-dependent CI in patients with early active RRMS than global or regional brain volumes. Our findings may advance our understanding of the neural substrates underlying CI characteristic for early RRMS.

Recovery of thalamic microstructural damage after Shiga toxin 2-associated hemolytic-uremic syndrome.

INTRODUCTION: The underlying pathophysiology of neurological complications in patients with hemolytic-uremic syndrome (HUS) remains unclear. It was recently attributed to a direct cytotoxic effect of Shiga toxin 2 (Stx2) in the thalamus. Conventional MRI of patients with Stx2-caused HUS revealed - despite severe neurological symptoms - only mild alterations if any, mostly in the thalamus. Against this background, we questioned: Does diffusion tensor imaging (DTI) capture the thalamic damage better than conventional MRI? Are neurological symptoms and disease course better reflected by thalamic alterations as detected by DTI? Are other brain regions also affected? METHODS: Three women with serious neurological deficits due to Stx2-associated HUS were admitted to MRI/DTI at disease onset. Two of them were longitudinally examined. Fractional anisotropy (FA) and mean diffusivity were computed to assess Stx2-caused microstructural damage. RESULTS: Compared to 90 healthy women, all three patients had significantly reduced thalamic FA. Thalamic mean diffusivity was only reduced in two patients. DTI of the longitudinally examined women demonstrated slow normalization of thalamic FA, which was paralleled by clinical improvement. CONCLUSION: Whereas conventional MRI only shows slight alterations based on subjective evaluation, DTI permits quantitative, objective, and longitudinal assessment of cytotoxic cerebral damage in individual patients.

Lupin protein positively affects plasma LDL cholesterol and LDL:HDL cholesterol ratio in hypercholesterolemic adults after four weeks of supplementation: a randomized, controlled crossover study.

BACKGROUND: A couple of studies indicate a favorable impact of lupin protein on cardiovascular risk factors in humans. These studies, however, used relatively high doses of > 33 g/d, which can hardly be consumed under physiological conditions. Therefore, we investigated the effect of 25 g/d lupin protein isolate (LPI) on selected cardiovascular markers and on serum amino acids. METHODS: A total of 33 hypercholesterolemic subjects participated in a randomized, controlled, double-blind crossover study. LPI and the active comparator milk protein isolate (MPI) were incorporated in protein drinks and consumed over 8 wk separated by a 4 wk washout period. Anthropometric data, blood pressure, and nutrient intake were assessed at baseline and after 8 wk of both protein interventions. Blood was sampled at baseline, wk 4 and wk 8. All 33 subjects were included in final statistical analyses using repeated measures ANOVA with the general linear model or using linear mixed model. RESULTS: Except for higher HDL cholesterol at wk 4 of LPI (P ≤ 0.036), anthropometric parameters, blood pressure, and plasma lipids did not differ among LPI and MPI intervention. Compared to baseline, the primary outcome LDL cholesterol was significantly reduced after 4 wk of both interventions (P ≤ 0.008), while LDL:HDL cholesterol ratio was decreased only by LPI (P = 0.003). These time effects were restricted to subjects with higher hypercholesterolemia and disappeared after 8 wk. Blood pressure was reduced after 8 wk of LPI (P ≤ 0.044). Almost all serum amino acids were higher at wk 4 but not at wk 8 of MPI compared to LPI. Following 4 wk and 8 wk of LPI intervention, most amino acids remained unchanged. Both interventions caused a slight, but significant rise in body weight and body fat after 8 wk (P ≤ 0.045). CONCLUSION: In conclusion, 25 g LPI can beneficially modulate plasma LDL cholesterol at least over short-term. Using appropriate dietetic conditions that improve consumer compliance and avoid changes in energy intake as well as in body composition, lupin protein could positively impact cardiovascular risk factors particularly in individuals with higher hypercholesterolemia. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01304992.

UVB exposure of farm animals: study on a food-based strategy to bridge the gap between current vitamin D intakes and dietary targets.

Vitamin D deficiency is a global health problem. This study aimed to investigate the efficacy of ultraviolet (UV) B radiation for improving vitamin D3 content of eggs and meat. In a two-factorial design hens that received diets with 0 (-D3) or 3,000 IU (+D3) vitamin D3/kg were non-exposed (-UVB) or exposed to UVB radiation (+UVB) for 3 h daily over 4 weeks. Data show that UVB radiation was very effective in raising the vitamin D3 content of egg yolk and meat. Egg yolk from +UVB/-D3 hens had a higher vitamin D3 content (17.5±7.2 µg/100 g dry matter (DM)) than those from the -UVB/+D3 group (5.2±2.4 µg/100 g DM, p<0.01). Vitamin D3 content in egg yolk of vitamin D3-supplemented hens could be further increased by UVB radiation (32.4±10.9 µg/100 g DM). The content of 25-hydroxyvitamin D3 (25(OH)D3) in the egg yolk also increased in response to UVB, although less pronounced than vitamin D3. Meat revealed about 4-fold higher vitamin D3 contents in response to UVB than to dietary vitamin D3 (p<0.001). In conclusion, exposure of hens to UVB is an efficient approach to provide consumers with vitamin D3-enriched foods from animal sources.