Predominant subcortical accumulation of ¹⁸F-flortaucipir binding in behavioral variant frontotemporal dementia

Cho, Hanna,Seo, Sang Won,Choi, Jae Yong,Lee, Hye Sun,Ryu, Young Hoon,Lee, Myung Sik,Na, Duk L.,Kim, Hee Jin,Lyoo, Chul Hyoung PERGAMON PRESS LTD 2018 NEUROBIOLOGY OF AGING Vol. No.

<P><B>Abstract</B></P> <P>Behavioral variant frontotemporal dementia (bvFTD) is the most common form of frontotemporal dementia, and tau pathology can be found in 40%–50% of bvFTD patients. In this study, we sought to investigate <SUP>18</SUP>F-flortaucipir-binding patterns and their correlates in clinically diagnosed bvFTD patients by comparing with results for Alzheimer's disease (AD) patients. We enrolled 20 bvFTD, 20 AD, and 20 age-matched healthy subjects who underwent neuropsychological tests, magnetic resonance imaging, and tau positron emission tomography scans with <SUP>18</SUP>F-flortaucipir. Regional standardized uptake value ratios for the cerebral cortex and underlying white matter were compared between the 2 groups. The bvFTD patients showed increased <SUP>18</SUP>F-flortaucipir binding in the putamen and globus pallidus when compared to the healthy controls. In addition, bvFTD was associated with increased binding in the white matter regions underlying the frontal, anterior cingulate, and insula cortices. The bvFTD patients may exhibit predominantly subcortical <SUP>18</SUP>F-flortaucipir-binding pattern that is distinct from the patterns seen in AD patients. We hypothesize that the clinical characteristics of bvFTD patients may be attributable to the dysfunctional frontal-subcortical networks. However, concerns remain regarding unknown “off-target” binding in the white matter and the basal ganglia.</P>

Regional amyloid burden and lacune in pure subcortical vascular cognitive impairment

Hong, Yun Jeong,Kim, Chan-Mi,Kim, Ji Eun,Roh, Jee Hoon,Kim, Jae Seung,Seo, Sang Won,Na, Duk L.,Lee, Jae-Hong PERGAMON PRESS LTD 2017 NEUROBIOLOGY OF AGING Vol. No.

<P><B>Abstract</B></P> <P>We investigated the amyloid and vascular burden in Pittsburgh compound B (PiB)–negative subcortical vascular mild cognitive impairment (svMCI) and PiB-negative subcortical ischemic vascular dementia (SIVD) to elucidate the potential roles of amyloid deposition and small vessel disease (SVD). Thirty-eight svMCI patients and 42 SIVD patients were enrolled. The regional PiB uptake values and SVD markers were obtained and compared between groups. Additionally, correlations among amyloid burden, SVD, and cognition were made. Patients with PiB-negative SIVD showed more amyloid deposition than those with PiB-negative svMCI, particularly in the cuneus, lingual gyrus, supramarginal, and angular gyri. Despite subthreshold levels for amyloid deposition, our findings showed a marked regional difference in amyloid uptake between svMCI and SIVD, particularly in posteriorly located brain areas. However, lacune, a proxy for vascular burden, showed a broader association with cognition and had more impacts on developing dementia than amyloid burden. The topographical pattern of amyloid deposition and its impact on clinical status in pure subcortical vascular cognitive impairment were different from those in Alzheimer's disease.</P>

Sex-specific association of sex hormones and gonadotropins, with brain amyloid and hippocampal neurodegeneration

Lee, Jun Ho,Byun, Min Soo,Yi, Dahyun,Choe, Young Min,Choi, Hyo Jung,Baek, Hyewon,Sohn, Bo Kyung,Lee, Jun-Young,Kim, Hyun Jung,Kim, Jee Wook,Lee, Younghwa,Kim, Yu Kyeong,Sohn, Chul-Ho,Woo, Jong Inn,Lee PERGAMON PRESS LTD 2017 NEUROBIOLOGY OF AGING Vol. No.

<P><B>Abstract</B></P> <P>This study aimed to examine the sex-specific association between serum sex hormones and gonadotropins and the cerebral beta-amyloid (Aβ) burden and hippocampal neurodegeneration in subjects with normal cognition and impaired cognition. Two hundred sixty-five older subjects received clinical assessments, serum measurements of sex hormones, gonadotropins, <SUP>11</SUP>C-Pittsburgh compound B-positron emission tomography, and magnetic resonance imaging. In females, higher free testosterone and gonadotropin levels were associated with lower cerebral Aβ positivity. In males, free testosterone was positively related to hippocampal volume with significant interaction with cognitive status. Further subgroup analyses showed that the association was significant only in impaired cognition but not in normal cognition. Free estradiol was not associated with Aβ burden or hippocampal neurodegeneration in either sex. These results suggest that testosterone might inhibit the early pathological accumulation of Aβ in females and delay neurodegeneration in males.</P>

Paleoparasitological study on the soil sediment samples from archaeological sites of ancient Silla Kingdom in Korean peninsula

Kim, M.J.,Seo, M.,Oh, C.S.,Chai, J.Y.,Lee, J.,Kim, G.j.,Ma, W.Y.,Choi, S.J.,Reinhard, K.,Araujo, A.,Shin, D.H. PERGAMON PRESS LTD 2016 QUATERNARY INTERNATIONAL Vol.405 No.2

<P>Due to paleoparasitology's relatively late beginnings, the fundamental data necessary for any reasonably complete understanding of parasitic infection patterns in Korean history remains insufficient. Especially with respect to ancient samples dating to before the Joseon Dynasty (1392-1910 CE), few cases have been analyzed by parasitological techniques. In the present study, we therefore undertook a series of paleoparasitological examinations of archaeological samples from the ancient Silla Kingdom (57 BCE-935 CE). Specifically, in soil samples obtained from shell midden and mountain top fortress sites, we observed Ascaris lumbricoides, Trichuris trichiura, Dicrocoelid and Taenia sp. eggs. The results of our current investigation of strata and samples from the prosperous first-millennium era of the Silla Kingdom are encouraging for a comprehensive understanding of the parasitic infection patterns in the earlier days of Korean history that could not be obtained by any previous studies. (C) 2015 Elsevier Ltd and INQUA. All rights reserved.</P>

Differential effects of blood insulin and HbA1c on cerebral amyloid burden and neurodegeneration in nondiabetic cognitively normal older adults

Byun, Min Soo,Kim, Hyun Jung,Yi, Dahyun,Choi, Hyo Jung,Baek, Hyewon,Lee, Jun Ho,Choe, Young Min,Sohn, Bo Kyung,Lee, Jun-Young,Lee, Younghwa,Ko, Hyunwoong,Kim, Yu Kyeong,Lee, Yun-Sang,Sohn, Chul-Ho,Woo PERGAMON PRESS LTD 2017 NEUROBIOLOGY OF AGING Vol. No.

<P><B>Abstract</B></P> <P>We tested the hypothesis that lower insulin or higher glycated hemoglobin (HbA1c) levels in blood are associated with increased cerebral beta amyloid (Aβ) deposition and neurodegeneration in nondiabetic cognitively normal (CN) older adults. A total of 205 nondiabetic CN older adults underwent comprehensive clinical assessment, [<SUP>11</SUP>C]Pittsburgh compound B (PiB)-positron emission tomography (PET), [<SUP>18</SUP>F]fluorodeoxyglucose-PET, magnetic resonance imaging, and blood sampling for fasting insulin and HbA1c measurement. Lower blood insulin was significantly associated with increased Aβ positivity rates and decreased cerebral glucose metabolism in the AD-signature region. In contrast, higher HbA1c levels were not associated with Aβ positivity rates but were significantly associated with higher rates of having neurodegeneration in the AD-signature regions. Our results suggest different roles of insulin and HbA1c in AD pathogenesis, in that decreased blood insulin below optimal levels may contribute to increasing cerebral Aβ deposition and neurodegeneration whereas impaired glycemic control may aggravate neurodegeneration through a nonamyloid mechanism in nondiabetic CN older adults.</P>

Repression of adenosine triphosphate–binding cassette transporter ABCG2 by estrogen increases intracellular glutathione in brain endothelial cells following ischemic reperfusion injury

Shin, Jin A.,Jeong, Sae Im,Kim, Hye Won,Jang, Gyeonghui,Ryu, Dong-Ryeol,Ahn, Young-Ho,Choi, Ji Ha,Choi, Youn-Hee,Park, Eun-Mi PERGAMON PRESS LTD 2018 NEUROBIOLOGY OF AGING Vol. No.

<P><B>Abstract</B></P> <P>The adenosine triphosphate–binding cassette efflux transporter ABCG2, which is located in the blood-brain barrier limits the entry of endogenous compounds and xenobiotics into the brain, and its expression and activity are regulated by estrogen. This study was aimed to define the role of ABCG2 in estrogen-mediated neuroprotection against ischemic injury. ABCG2 protein levels before and after ischemic stroke were increased in the brain of female mice by ovariectomy, which were reversed by estrogen replacement. In brain endothelial cell line bEnd.3, estrogen reduced the basal ABCG2 protein level and efflux activity and protected cells from ischemic injury without inducing ABCG2 expression. When bEnd.3 cells were transfected with ABCG2 small interfering RNA, ischemia-induced cell death was reduced, and the intracellular concentration of glutathione, an antioxidant that is transported by ABCG2, was increased. In addition, after ischemic stroke in ovariectomized mice, estrogen prevented the reduction of intracellular glutathione level in brain microvessels. These data suggested that the suppression of ABCG2 by estrogen is involved in neuroprotection against ischemic injury by increasing intracellular glutathione, and that the modulation of ABCG2 activity offers a therapeutic target for brain diseases in estrogen-deficient aged women.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Age-related changes in pial arterial structure and blood flow in mice

Kang, H.M.,Sohn, I.,Jung, J.,Jeong, J.W.,Park, C. PERGAMON PRESS LTD 2016 NEUROBIOLOGY OF AGING Vol. No.

Age-related cerebral blood flow decreases are thought to deteriorate cognition and cause senescence, although the related mechanism is unclear. To investigate the relationships between aging and changes in cerebral blood flow and vasculature, we obtained fluorescence images of young (2-month-old) and old (12-month-old) mice using indocyanine green (ICG). First, we found that the blood flow in old mice's brains is lower than that in young mice and that old mice had more curved pial arteries and fewer pial artery junctions than young mice. Second, using Western blotting, we determined that the ratio of collagen to elastin (related to cerebral vascular wall distensibility) increased with age. Finally, we found that the peak ICG intensity and blood flow index decreased, whereas the mean transit time increased, with age in the middle cerebral artery and superior sagittal sinus. Age-related changes in pial arterial structure and composition, concurrent with the observed changes in the blood flow parameters, suggest that age-related changes in the cerebral vasculature structure and distensibility may induce altered brain blood flow.

Late Pleistocene-Holocene sedimentary facies and evolution of the Jeju Strait shelf, southwest Korea

Hong, Seok-Hwi,Chang, Tae Soo,Lee, Gwang-Soo,Kim, Jin Cheul,Choi, Jooah,Yoo, Dong-Geun PERGAMON PRESS LTD 2019 QUATERNARY INTERNATIONAL Vol.519 No.-

<P><B>Abstract</B></P> <P>The depositional environments of the Jeju Strait shelf since the last interglacial period are analyzed using sedimentary structures, grain size textures, sediment color, and optically-stimulated luminescence (OSL) and accelerator mass spectrometry (AMS) ages of vibro-cores. The shelf deposits can be divided into 12 sedimentary facies grouped into four depositional units: 1) shelf sand, 2) estuarine sand/mud, 3) fluvial sand/mud, and 4) shelf sand/mud. Each unit is separated by a sharp and unconformable erosion boundary. Unit 1 shows massive to slightly bedded sandy shells with oyster fragments, representing a shelf environment during sea-level highstand. The OSL date of the base of the unit is 124.4 ± 10.0 ka. Unit 2 is characterized by thin periodic parallel laminated mud, suggesting tidal signatures in tidal flats. Sediments are typically moderate brownish, suggesting extreme weathering after deposition. The OSL dates of this unit range from 81.1 ± 5.3 to 74.2 ± 4.7. Unit 3 consists of lower cross-bedded sand and laminated mud with fining-upward successions. It is interpreted as the product of channel deposits in a fluvial environment during a sea-level falling. The OSL ages of Unit 3 range from 50.6 ± 2.9 to 26.1 ± 1.6 ka, belonging to the Weichselian glacial period. The uppermost unit (Unit 4) is composed of homogeneous mud and massive sand with molluscan shell fragments in the modern shelf environment during sea-level highstand. OSL and <SUP>14</SUP>C-AMS ages range from 0.32 ± 0.02 to 11.2 ± 0.1 ka. Consequently, the late Pleistocene-Holocene sedimentary facies in this area consist of marine and non-marine environments, which mainly correspond to sea-level changes.</P>

Suspended sediment source tracing at the Juksan Weir in the Yeongsan River using composite fingerprints

Lim, Young Shin,Kim, Jong Wook,Kim, Jin Kwan PERGAMON PRESS LTD 2019 QUATERNARY INTERNATIONAL Vol.519 No.-

<P><B>Abstract</B></P> <P>Since 2008, the Yeongsan River in South Korea has experienced significant environmental changes, such as the dredging of its riverbed and the construction of large weirs. The quantity and quality of the fine sediments that provide adsorptive surfaces for pollutants has an influence on water quality, human health, and aquatic organisms. To determine the dominant contributors and seasonal variation in suspended sediment at the Juksan Weir in the Yeongsan River, reservoir sediments were obtained at monthly intervals using a time-integrated suspended sediment sampler. We applied a fingerprinting procedure combined with a multivariate mixing model to discriminate between different types of land use and to apportion sediment sources. Cropland topsoils, forest topsoils and channel bank materials were selected as end-members, and fallout radionuclides, geochemical elemental concentrations and the magnetic properties of each source material were used as diagnostic tracer properties. According to the mixing model results, channel bank materials were the dominant source of reservoir sediment during the entire monitoring period. In winter, there was a slight increase in the contribution from forest topsoils, which could have been influenced by freeze–thaw processes. Despite the high proportion of agricultural land use in the study catchment and its proximity to the river, there was a small sediment contribution from the cropland topsoils. There were uncertainties resulting from an imperfect classification due to the spatial distributions of forest and cropland and the combination of the mixing model with the fingerprinting procedure. The results provide the basis for developing strategies for sediment control and reservoir management.</P>

Audit Report Information Content and the Provision of Non-audit Services: Evidence from Spanish Lending Decisions

최순규,박영렬,문두철,송상철,Andres GUIRAL,강진구 Pergamon Press Ltd. 2014 Auditing and Taxation Vol.23 No.1