Suchergebnisse

Doublecortin (DCX), a microtubule-associated protein, specifically expresses in neuronal precursors. This protein has been used as a marker for neuronal precursors and neurogenesis. In the present study, we observed differences in DCX immunoreactivity and its protein levels in the hippocampal dentate gyrus between adult and aged dogs. In the adult dog, DCX immunoreactive cells with well-stained processes were detected in the subgranular zone of the dentate gyrus. Numbers of DCX immunoreactive cells in the dentate gyrus of the aged dog were significantly decreased compared to those in the adult dog. DCX immunoreactive cells in both adult and aged dog did not show NeuN (a marker for mature neurons) immunoreactivity. NeuN immunoreactivity in the aged dog was poor compared to that in the adult dog. DCX protein level in the aged dentate gyrus was decreased by 80% compared to that in the adult dog. These results suggest that the reduction of DCX in the aged hippocampal dentate gyrus may be involved in some neural deficits related to the hippocampus. ; The authors would like to thank Mr. Seok Han, Mr. Seung Uk Lee and Ms. Hyun Sook Kim for their technical help in this study. This work was supported by the Nano/Bio program of Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government (MOST) (No. M10641450002-06N4145- 00200).

BACKGROUND: Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), spreads rapidly and has attracted worldwide attention. METHODS: To improve the forecast accuracy and investigate the spread of SARS-CoV-2, we constructed four mathematical models to numerically estimate the spread of SARS-CoV-2 and the efficacy of eradication strategies. RESULTS: Using the Susceptible-Exposed-Infected-Removed (SEIR) model, and including measures such as city closures and extended leave policies implemented by the Chinese government that effectively reduced the β value, we estimated that the β value and basic transmission number, R(0), of SARS-CoV-2 was 0.476/6.66 in Wuhan, 0.359/5.03 in Korea, and 0.400/5.60 in Italy. Considering medicine and vaccines, an advanced model demonstrated that the emergence of vaccines would greatly slow the spread of the virus. Our model predicted that 100,000 people would become infected assuming that the isolation rate α in Wuhan was 0.30. If quarantine measures were taken from March 10, 2020, and the quarantine rate of α was also 0.3, then the final number of infected people was predicted to be 11,426 in South Korea and 147,142 in Italy. CONCLUSIONS: Our mathematical models indicate that SARS-CoV-2 eradication depends on systematic planning, effective hospital isolation, and SARS-CoV-2 vaccination, and some measures including city closures and leave policies should be implemented to ensure SARS-CoV-2 eradication.

Objects The diffusion-based spherical mean technique (SMT) provides a novel model to relate multi-b-value diffusion magnetic resonance imaging (MRI) data to features of tissue microstructure. We propose the first clinical application of SMT to image the brain of patients with multiple sclerosis (MS) and investigate clinical feasibility and translation. Methods Eighteen MS patients and nine age- and sex-matched healthy controls (HCs) underwent a 3.0 Tesla scan inclusive of clinical sequences and SMT images (isotropic resolution of 2 mm). Axial diffusivity (AD), apparent axonal volume fraction (V-ax), and effective neural diffusivity (D-ax) parametric maps were fitted. Differences in AD, V-ax, and D-ax between anatomically matched regions reflecting different tissues types were estimated using generalized linear mixed models for binary outcomes. Results Differences were seen in all SMT-derived parameters between chronic black holes (cBHs) and T2-lesions (P <= 0.0016), in V-ax and AD between T2-lesions and normal appearing white matter (NAWM) (P < 0.0001), but not between the NAWM and normal WM in HCs. Inverse correlations were seen between V-ax and AD in cBHs (r = -0.750, P = 0.02); in T2-lesions D-ax values were associated with V-ax (r = 0.824, P < 0.0001) and AD (r = 0.570, P = 0.014). Interpretations SMT-derived metrics are sensitive to pathological changes and hold potential for clinical application in MS patients. ; Sources of support include: extramural program of the National Institutes of Health (NIH) (NIBIB K01 EB009120, R01 EB000461, and K25 EB013659), the Clinical and Translational Science Awards (UL1TR000445-06 from National Center for Advancing Translational Sciences/NIH), the European Union Horizon 2020 (EU H2020 634541-2), the EPSRC (Engineering and Physical Sciences Research Council), United Kingdom (UK) (UK EPSRC EP/M020533/1, UK EPSRC EP/N018702/1), the National MS Society (MS Clinical Mentorship Program, NMSS PP-180129686 and NMSS RG-1501-02840).

Astrocytes perform neuron-supportive tasks, repair and scarring process in the central nervous system. In this study, we observed glial fibrillary acidic protein (GFAP), a marker for astrocytes, immunoreactivity in the dentate gyrus and hippocampus proper (CA1–3 region) of adult (2–3 years of age) and aged (10–12 years of age) dogs. In the adult group, GFAP immunoreactive astrocytes were distributed in all layers of the dentate gyrus and CA1–3 region, except in the stratum pyramidale of the CA1–3 region. In the aged group, GFAP immunoreactivity decreased markedly in the molecular layer of the dentate gyrus. However, GFAP immunoreactivity in the CA1–3 region increased in all layers, and the cytoplasm of GFAP immunoreactive astrocytes was hypertrophied. GFAP protein levels in the aged dentate gyrus decreased; however, GFAP levels in the CA1–3 region increased. These results suggest that the morphology of astrocytes and GFAP protein levels in the hippocampal dentate gyrus and CA1 region are changed, respectively, with age. ; The authors would like to thank Mr. Seung Uk Lee and Ms. Hyun Sook Kim for their technical help in this study. This work was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (KRF-2007–313-E00048).