Correlation Tensor MRI deciphers underlying kurtosis sources in stroke.

Noninvasively detecting and characterizing modulations in cellular scale micro-architecture remains a desideratum for contemporary neuroimaging. Diffusion MRI (dMRI) has become the mainstay methodology for probing microstructure, and, in ischemia, its contrasts have revolutionized stroke management. Diffusion kurtosis imaging (DKI) has been shown to significantly enhance the sensitivity of stroke detection compared to its diffusion tensor imaging (DTI) counterparts. However, the interpretation of DKI remains ambiguous as its contrast may arise from competing kurtosis sources related to the anisotropy of tissue components, diffusivity variance across components, and microscopic kurtosis (e.g., arising from cross-sectional variance, structural disorder, and restriction). Resolving these sources may be fundamental for developing more specific imaging techniques for stroke management, prognosis, and understanding its pathophysiology. In this study, we apply Correlation Tensor MRI (CTI) - a double diffusion encoding (DDE) methodology recently introduced for deciphering kurtosis sources based on the unique information captured in DDE's diffusion correlation tensors - to investigate the underpinnings of kurtosis measurements in acute ischemic lesions. Simulations for the different kurtosis sources revealed specific signatures for cross-sectional variance (representing neurite beading), edema, and cell swelling. Ex vivo CTI experiments at 16.4 T were then performed in an experimental photothrombotic stroke model 3 h post-stroke (N = 10), and successfully separated anisotropic, isotropic, and microscopic non-Gaussian diffusion sources in the ischemic lesions. Each of these kurtosis sources provided unique contrasts in the stroked area. Particularly, microscopic kurtosis was shown to be a primary "driver" of total kurtosis upon ischemia; its large increases, coupled with decreases in anisotropic kurtosis, are consistent with the expected elevation in cross-sectional variance, likely linked to beading effects in small objects such as neurites. In vivo experiments at 9.4 T at the same time point (3 h post ischemia, N = 5) demonstrated the stability and relevance of the findings and showed that fixation is not a dominant confounder in our findings. In future studies, the different CTI contrasts may be useful to address current limitations of stroke imaging, e.g., penumbra characterization, distinguishing lesion progression form tissue recovery, and elucidating pathophysiological correlates.

Cost of Illness in Patients with Duchenne Muscular Dystrophy in Portugal: The COIDUCH Study.

OBJECTIVE: The aim of this study was to estimate the cost of illness (COI) of Duchenne muscular dystrophy (DMD) and its relation to disease progression, using age as a proxy, and according to the ambulatory status of patients. METHODS: We conducted a cross-sectional study of patients diagnosed with DMD identified through the Portuguese Neuromuscular Patients Association (APN). Data regarding patient and caregiver demographics, patient health status, resource utilization and cost, and informal care were collected using a custom semistructured questionnaire. Labor productivity and absenteeism losses were captured using the Work Productivity and Activity Impairment questionnaire. Costs were valued using a societal perspective. RESULTS: A total of 46 patient-caregiver pairs were included, of which eight of the patients were ambulant and 38 were nonambulant. Age had a decreasing effect on COI, independent of the patient's disease stage. Annualized lifetime costs were at their highest in nonambulant patients around the mean age of loss of ambulation (10 years of age). The mean per patient stage-specific costs (year 2019 values) of DMD were estimated at €48,991 in the nonambulant stage and €19,993 in the ambulant stage. Direct nonmedical costs were the main cost drivers, followed by indirect costs. CONCLUSIONS: Our results indicate a close relation between overall disease costs and disease progression. DMD is associated with a substantial economic burden, which appears to be larger around the time ambulation is lost (10 years of age). The availability of new therapeutic options that delay disease progression, especially loss of ambulation, may prove to be highly beneficial for not only patients with DMD but also their families and society.

Amino Acid Profile and Protein Quality Assessment of Macroalgae Produced in an Integrated Multi-Trophic Aquaculture System.

Seaweeds are a recognized source of bioactive compounds and techno-functional ingredients. However, its protein fraction is still underexplored. The aim of this study was to determine the total and free amino acid profile and protein content of four seaweeds species (Porphyra dioica, Porphyra umbilicalis,Gracilaria vermiculophylla, and Ulva rigida) produced in an integrated multi-trophic aquaculture system, while assessing their protein quality. Samples were submitted to acid and alkaline hydrolysis (total amino acids) and to an aqueous extraction (free amino acids) followed by an automated online derivatization procedure, and analyzed by reverse phase-high performance liquid chromatography. Protein-, non-protein and total-nitrogen were quantified by the Kjeldahl method. Crude and true protein contents were estimated based on the nitrogen and amino acid composition. Protein quality was assessed based on the amino acids profile. Porphyra species presented the highest protein content compared to the remaining three seaweed species tested. All samples presented a complete profile of essential amino acids and a high quality protein profile, according to World Health Organization and Food and Agriculture Organization standards. Methionine and tryptophan were the first limiting amino acids in all species. Red species (Porphyra and Gracilaria) presented high levels of free alanine, glutamic, and aspartic acids. The results highlight the potential of using seaweeds as an alternative and sustainable source of protein and amino acids for human nutrition and industrial food processing.

Dental prophylaxis influence in tooth color assessment-Clinical study.

OBJECTIVE: To evaluate dental prophylaxis influence in tooth color assessment with the use of different methods. MATERIALS AND METHODS: Volunteers were consecutively recruited and screened according to appropriate inclusion/exclusion criteria. Each participant's upper right central incisive and canine color was measured before and after dental prophylaxis with a one-week interval. Tooth color assessment was performed by calibrated operators and the patient using a VITA Classical shade guide and by spectrophotometric methods with a proper device (SpectroShade). Color was reported as mean with SD of Commission Internationale De l'Eclairage (CIE) L*a*b* values, ΔEab and ΔE00 . One-way analysis of variance and Tukey post hoc were performed to assess differences between methods and paired t test for assessing differences in tooth color coordinates after dental prophylaxis. Values of P < .05 were taken as significant. RESULTS: Fifty patients were included. Self-assessed dental prophylaxis effects equated to a significantly different mean ΔE00 value of 2.3 ± 1.7 (P < .01), when compared to the calibrated operator reported 0.8 ± 1.1 and the spectrophotometer 1.0 ± 0.5. Half of volunteer's ΔE00 values surpassed the acceptability threshold, when compared to 28% from investigator and 10% from spectrophotometer. CONCLUSION: Performing a dental prophylaxis did have an influence in tooth color perception with a higher self-perceived effect in the patient assessment. CLINICAL SIGNIFICANCE: The results of this study suggest that performing professional dental prophylaxis presented a perceived effect in tooth color regardless of the method used being that patients precepted whiter and less yellowish teeth. Since extrinsic stain is considered as one of the factors that could influence tooth color assessment, performing professional dental prophylaxis prior to composite or ceramic color selection in anterior teeth restorations could consequently increase treatment predictability.