1.Comparative study of synthesised hyroxyapatite from pure chemicals and Malaysian natural limestone precursors.
S H Abu Bakar ; Z Hussein ; S L Hee ; F Fazan
The Medical journal of Malaysia 2004;59 Suppl F():81-2
Hydroxyapatite, (HA; Ca1O(PO4)6(OH)2) has been successfully applied in medical and dental applications for several years due to its excellent biocompatibility. The usage of HA in Malaysia, however, is limited due to the lack of availability. Therefore the aim of this work is to produce HA materials from both pure chemicals and from Malaysian natural limestone precursors, and to compare their bulk properties. However, parts of Malaysian natural limestone deposits actually consist of a combination of Ca(OH)2 and CaCO3. In order to utilise the limestone to produce HA material, the combination of these commercially pure chemicals as HA precursors should still work. In order to test this hypothesis, two HAs were produced by wet synthesis technique utilising (a) combination of Ca(OH)2 + CaCO3 from pure commercial chemicals [WCC] and (b) a local natural limestone [WL] precursors. The HAs produced; WCC and WL, were compacted into discs and sintered at 1250 degrees C. The characterisations and evaluations conducted were XRD, SEM-EDX, FTIR and shrinkage factor. The results indicate that WL gives slightly better bulk properties compared to WCC.
Sjogren's syndrome B antibody
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MALAYSIAN
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hydroxyl group
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Calcium measurement
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Work
2.Prognosis of Patients with Behavioral Variant Frontotemporal Dementia Who have Focal Versus Diffuse Frontal Atrophy.
Jin San LEE ; Na Yeon JUNG ; Young Kyoung JANG ; Hee Jin KIM ; Sang Won SEO ; Juyoun LEE ; Yeo Jin KIM ; Jae Hong LEE ; Byeong C KIM ; Kyung Won PARK ; Soo Jin YOON ; Jee H JEONG ; Sang Yun KIM ; Seung Hyun KIM ; Eun Joo KIM ; Key Chung PARK ; David S KNOPMAN ; Duk L NA
Journal of Clinical Neurology 2017;13(3):234-242
BACKGROUND AND PURPOSE: Only a few studies have investigated the relationship between different subtypes and disease progression or prognosis in patients with behavioral variant frontotemporal dementia (bvFTD). Since a localized injury often produces more focal signs than a diffuse injury, we hypothesized that the clinical characteristics differ between patients with bvFTD who show diffuse frontal lobe atrophy (D-type) on axial magnetic resonance imaging (MRI) scans versus those with focal or circumscribed frontal lobe atrophy (F-type). METHODS: In total, 94 MRI scans (74 scans from bvFTD and 20 scans from age-matched normal controls) were classified into 35 D- and 39 F-type bvFTD cases based on an axial MRI visual rating scale. We compared baseline clinical characteristics, progression in motor and cognitive symptoms, and survival times between D- and F-types. Survival analyses were performed for 62 of the 74 patients. RESULTS: While D-type performed better on neuropsychological tests than F-type at baseline, D-type had higher baseline scores on the Unified Parkinson's Disease Rating Scale (UPDRS) Part III. Evaluations of motor progression showed that the disease duration with motor symptoms was shorter in D-type than F-type. Moreover, the survival time was shorter in D-type (6.9 years) than F-type (9.4 years). Cox regression analyses revealed that a high UPDRS Part III score at baseline contributed to an increased risk of mortality, regardless of the pattern of atrophy. CONCLUSIONS: The prognosis is worse for D-type than for those with F-type. Shorter survival in D-type may be associated with the earlier appearance of motor symptoms.
Atrophy*
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Disease Progression
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Frontal Lobe
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Frontotemporal Dementia*
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Frontotemporal Lobar Degeneration
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Humans
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Magnetic Resonance Imaging
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Mortality
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Neurobehavioral Manifestations
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Neuropsychological Tests
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Parkinson Disease
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Prognosis*
3.Erratum to: Prognosis of Patients with Behavioral Variant Frontotemporal Dementia Who have Focal Versus Diffuse Frontal Atrophy.
Jin San LEE ; Na Yeon JUNG ; Young Kyoung JANG ; Hee Jin KIM ; Sang Won SEO ; Juyoun LEE ; Yeo Jin KIM ; Jae Hong LEE ; Byeong C KIM ; Kyung Won PARK ; Soo Jin YOON ; Jee H JEONG ; Sang Yun KIM ; Seung Hyun KIM ; Eun Joo KIM ; Key Chung PARK ; David S KNOPMAN ; Duk L NA
Journal of Clinical Neurology 2017;13(4):447-447
The original version of this article contained wrong information of an author which should be changed.
4.18F-THK5351 PET Positivity and Longitudinal Changes in Cognitive Function in β-Amyloid-Negative Amnestic Mild Cognitive Impairment
Min Young CHUN ; Jongmin LEE ; Jee Hyang JEONG ; Jee Hoon ROH ; Seung Jun OH ; Minyoung OH ; Jungsu S. OH ; Jae Seung KIM ; Seung Hwan MOON ; Sook-young WOO ; Young Ju KIM ; Yeong Sim CHOE ; Hee Jin KIM ; Duk L. NA ; Hyemin JANG ; Sang Won SEO
Yonsei Medical Journal 2022;63(3):259-264
Purpose:
Neuroinflammation is considered an important pathway associated with several diseases that result in cognitive decline. 18F-THK5351 positron emission tomography (PET) signals might indicate the presence of neuroinflammation, as well as Alzheimer’s disease-type tau aggregates. β-amyloid (Aβ)-negative (Aβ–) amnestic mild cognitive impairment (aMCI) may be associated with non-Alzheimer’s disease pathophysiology. Accordingly, we investigated associations between 18F-THK5351 PET positivity and cognitive decline among Aβ– aMCI patients.
Materials and Methods:
The present study included 25 amyloid PET negative aMCI patients who underwent a minimum of two follow-up neuropsychological evaluations, including clinical dementia rating-sum of boxes (CDR-SOB). The patients were classified into two groups: 18F-THK5351-positive and -negative groups. The present study used a linear mixed effects model to estimate the effects of 18F-THK5351 PET positivity on cognitive prognosis among Aβ– aMCI patients.
Results:
Among the 25 Aβ– aMCI patients, 10 (40.0%) were 18F-THK5351 positive. The patients in the 18F-THK5351-positive group were older than those in the 18F-THK5351-negative group (77.4±2.2 years vs. 70.0±5.5 years; p<0.001). There was no difference between the two groups with regard to the proportion of apolipoprotein E ε4 carriers. Interestingly, however, the CDR-SOB scores of the 18F-THK5351-positive group deteriorated at a faster rate than those of the 18F-THK5351-negative group (B=0.003, p=0.033).
Conclusion
The results of the present study suggest that increased 18F-THK5351 uptake might be a useful predictor of poor prognosis among Aβ– aMCI patients, which might be associated with increased neuroinflammation (ClinicalTrials.gov NCT02656498).
5.Clinical Characteristics of a Nationwide Hospital-based Registry of Mild-to-Moderate Alzheimer's Disease Patients in Korea: A CREDOS (Clinical Research Center for Dementia of South Korea) Study.
Hee Kyung PARK ; Duk L NA ; Seol Heui HAN ; Ji Young KIM ; Hae Kwan CHEONG ; Seong Yoon KIM ; Sang Yun KIM ; Chang Hyung HONG ; Do Kwan KIM ; Bon D KU ; So Young MOON ; Jun Young LEE ; Yong S SHIM ; Young Chul YOUN ; Eun Joo KIM ; Beoung Chae KIM ; Kee Hyung PARK ; Kyung R CHA ; Sang Won SEO ; Jae Hong LEE
Journal of Korean Medical Science 2011;26(9):1219-1226
With rapid population aging, the socioeconomic burden caused by dementia care is snowballing. Although a few community-based studies of Alzheimer's disease (AD) have been performed in Korea, there has never been a nationwide hospital-based study thereof. We aimed to identify the demographics and clinical characteristics of mild-to-moderate AD patients from the Clinical Research Center for Dementia of Korea (CREDOS) registry. A total of 1,786 patients were consecutively included from September 2005 to June 2010. Each patient underwent comprehensive neurological examination, interview for caregivers, laboratory investigations, neuropsychological tests, and brain MRI. The mean age was 74.0 yr and the female percentage 67.0%. The mean period of education was 7.1 yr and the frequency of early-onset AD (< 65 yr old) was 18.8%. Among the vascular risk factors, hypertension (48.9%) and diabetes mellitus (22.3%) were the most frequent. The mean score of the Korean version of Mini-Mental State Examination (K-MMSE) was 19.2 and the mean sum of box scores of Clinical Dementia Rating (CDR-SB) 5.1. Based on the well-structured, nationwide, and hospital-based registry, this study provides the unique clinical characteristics of AD and emphasizes the importance of vascular factors in AD in Korea.
Aged
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Aged, 80 and over
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Alzheimer Disease/complications/*diagnosis
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Brain/radionuclide imaging
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Caregivers
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Dementia/diagnosis
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Demography
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Diabetes Mellitus, Type 2/etiology
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Female
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Hospitals
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Humans
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Hypertension/etiology
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Interviews as Topic
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Magnetic Resonance Imaging
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Male
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Middle Aged
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Questionnaires
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*Registries
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Republic of Korea
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Risk Factors