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Lee CY, Nurul Zaidah AS, Nur Amalina G, Muhammad Azree E, Das S, Zar CT. A review of the use of Piper betel in oxidative stress disorders. LA CLINICA TERAPEUTICA 2014; 165:269-77. [PMID: 25366948 DOI: 10.7417/ct.2014.1758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Increase in prevalence of disease related oxidative stress disorders have been on the rise in the entire world since the past decades. Significant positive effects with few antioxidant properties in the modern drugs pave for the alternative medicines in managing the disease. Piper betel (P. betel), a herb, is known to possess high anti-oxidant, anti-diabetic, anti-atherosclerosis, anti-hyperlipidemic, anti-cancer and neuroprotective property. This review focused on the effect of P. betel on diabetes mellitus, atherosclerosis and chronic kidney disease, Alzheimer's disease and breast cancer. P. betel proved to show positive effects with specific outcomes towards these diseases. Moreover, the promising effect of P. betel in vitro studies was also highlighted in the present review. It is believed that the findings obtained in this review will draw the attention of the medical professionals and general public towards P. betel and it will open the door for further detailed research.
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Cheng SW, Ko CH, Yau SK, Mak C, Yuen YF, Lee CY. Novel use of idebenone in Leber’s hereditary optic neuropathy in Hong Kong. Hong Kong Med J 2014; 20:451-4. [DOI: 10.12809/hkmj134085] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Lee CY, Tabesh A, Nesland T, Jensen JH, Helpern JA, Spampinato MV, Bonilha L. Human brain asymmetry in microstructural connectivity demonstrated by diffusional kurtosis imaging. Brain Res 2014; 1588:73-80. [PMID: 25239477 DOI: 10.1016/j.brainres.2014.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 08/30/2014] [Accepted: 09/01/2014] [Indexed: 10/24/2022]
Abstract
Structural asymmetry of whole brain white matter (WM) pathways, i.e., the connectome, has been demonstrated using fiber tractography based on diffusion tensor imaging (DTI). However, DTI-based tractography fails to resolve axonal fiber bundles that intersect within an imaging voxel, and therefore may not fully characterize the extent of asymmetry. The goal of this study was to assess structural asymmetry with tractography based on diffusional kurtosis imaging (DKI), which improves upon DTI-based tractography by delineating intravoxel crossing fibers. DKI images were obtained from 42 healthy subjects. By using automatic segmentation, gray matter (GM) was parcellated into anatomically defined regions of interest (ROIs). WM pathways were reconstructed with both DKI- and DTI-based tractography. The connectivity between the ROIs was quantified with the streamlines connecting the ROIs. The asymmetry index (AI) was utilized to quantify hemispheric differences in the connectivity of cortical ROIs and of links interconnecting cortical ROIs. Our results demonstrated that leftward asymmetrical ROIs and links were observed in frontal, parietal, temporal lobes, and insula. Rightward asymmetrical ROI and links were observed in superior frontal lobe, cingulate cortex, fusiform, putamen, and medial temporal lobe. Interestingly, these observed structural asymmetries were incompletely identified with DTI-based tractography. These results suggest that DKI-based tractography can improve the identification of asymmetrical connectivity patterns, thereby serving as an additional tool in the evaluation of the structural bases of functional lateralization.
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Lee CY, Wan WS, Lui CY. Stereotatic-guided Biopsy of Mammographic Microcalcifications: When Shall We Use Digital Add-on Unit Instead of Prone Table Machine? HONG KONG JOURNAL OF RADIOLOGY 2014. [DOI: 10.12809/hkjr1413224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Lee CY. Adenosine protects Sprague Dawley rats from high-fat diet and repeated acute restraint stress-induced intestinal inflammation and altered expression of nutrient transporters. J Anim Physiol Anim Nutr (Berl) 2014; 99:317-25. [PMID: 25196093 DOI: 10.1111/jpn.12247] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 07/25/2014] [Indexed: 12/18/2022]
Abstract
This study investigated the effect of repeated acute restraint stress and high-fat diet (HFD) on intestinal expression of nutrient transporters, concomitant to intestinal inflammation. The ability of adenosine to reverse any change was examined. Six-week-old male Sprague Dawley rats were divided into eight groups: control or non-stressed (C), rats exposed to restraint stress for 6 h per day for 14 days (S), control rats fed with HFD (CHF) and restraint-stressed rats fed with HFD (SHF); four additional groups received the same treatments and were also given 50 mg/l adenosine dissolved in drinking water. Fasting blood glucose, plasma insulin, adiponectin and corticosterone were measured. Intestinal expression of SLC5A1, SLC2A2, NPC1L1 and TNF-α was analysed. Histological evaluation was conducted to observe for morphological and anatomical changes in the intestinal tissues. Results showed that HFD feeding increased glucose and insulin levels, and repeated acute restraint stress raised the corticosterone level by 22%. Exposure to both stress and HFD caused a further increase in corticosterone to 41%, while decreasing plasma adiponectin level. Restraint stress altered intestinal expression of SLC5A1, SLC2A2 and NPC1L1. These changes were enhanced in SHF rats. Adenosine was found to alleviate HFD-induced increase in glucose and insulin levels, suppress elevation of corticosterone in S rats and improve the altered nutrient transporters expression profiles. It also prevented upregulation of TNF-α in the intestine of SHF rats. In summary, a combination of stress and HFD exaggerated stress- and HFD-induced pathophysiological changes in the intestine, and biochemical parameters related to obesity. Adenosine attenuated the elevation of corticosterone and altered expression of SLC5A1, NPC1L1 and TNF-α.
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Liu YT, Chen RK, Lin SJ, Chen YC, Chin SW, Chen FC, Lee CY. Analysis of sequence diversity through internal transcribed spacers and simple sequence repeats to identify Dendrobium species. GENETICS AND MOLECULAR RESEARCH 2014; 13:2709-17. [PMID: 24782085 DOI: 10.4238/2014.april.8.15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The Orchidaceae is one of the largest and most diverse families of flowering plants. The Dendrobium genus has high economic potential as ornamental plants and for medicinal purposes. In addition, the species of this genus are able to produce large crops. However, many Dendrobium varieties are very similar in outward appearance, making it difficult to distinguish one species from another. This study demonstrated that the 12 Dendrobium species used in this study may be divided into 2 groups by internal transcribed spacer (ITS) sequence analysis. Red and yellow flowers may also be used to separate these species into 2 main groups. In particular, the deciduous characteristic is associated with the ITS genetic diversity of the A group. Of 53 designed simple sequence repeat (SSR) primer pairs, 7 pairs were polymorphic for polymerase chain reaction products that were amplified from a specific band. The results of this study demonstrate that these 7 SSR primer pairs may potentially be used to identify Dendrobium species and their progeny in future studies.
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But WM, Chan A, Lee CY, Lam A, Lam YY, Loung PY, Ng KL, Wong MY, Chan KT, Tse WY, Shek CC. Etiologies of 46,XY disorders of sex development (DSD): a collaborative study in Hong Kong. INTERNATIONAL JOURNAL OF PEDIATRIC ENDOCRINOLOGY 2013. [PMCID: PMC3850129 DOI: 10.1186/1687-9856-2013-s1-p185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Chan AOK, But WM, Lee CY, Lam YY, Ng KL, Tung J, Cheung PT, Chan D, Tse WY, Shek CC. Diagnosis of 5α–reductase 2 deficiency: is measurement of dihydrotestosterone essential? INTERNATIONAL JOURNAL OF PEDIATRIC ENDOCRINOLOGY 2013. [PMCID: PMC3892203 DOI: 10.1186/1687-9856-2013-s1-p186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lee CY, Cheng SW, Lee LK. Use of aromatase inhibitor in a girl with peripheral precocious puberty. INTERNATIONAL JOURNAL OF PEDIATRIC ENDOCRINOLOGY 2013. [PMCID: PMC3850473 DOI: 10.1186/1687-9856-2013-s1-p74] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Lee CY, Tabesh A, Benitez A, Helpern JA, Jensen JH, Bonilha L. Microstructural integrity of early- versus late-myelinating white matter tracts in medial temporal lobe epilepsy. Epilepsia 2013; 54:1801-9. [PMID: 24032670 DOI: 10.1111/epi.12353] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2013] [Indexed: 01/19/2023]
Abstract
PURPOSE Patients with medial temporal lobe epilepsy (MTLE) exhibit structural brain damage involving gray matter (GM) and white matter (WM). The mechanisms underlying tissue loss in MTLE are unclear and may be associated with a combination of seizure excitotoxicity and WM vulnerability. The goal of this study was to investigate whether late-myelinating WM tracts are more vulnerable to injury in MTLE compared with early myelinating tracts. METHODS Diffusional kurtosis imaging scans were obtained from 25 patients with MTLE and from 36 matched healthy controls. Diffusion measures from regions of interest (ROIs) for both late- and early myelinating WM tracts were analyzed. Regional Z-scores were computed with respect to normal controls to compare WM in early myelinating tracts versus late-myelinating tracts. KEY FINDINGS We observed that late-myelinating tracts exhibited a larger decrease in mean, axial, and radial kurtosis compared with early myelinating tracts. We also observed that the change in radial kurtosis was more pronounced in late-myelinating tracts ipsilateral to the side of seizure onset. SIGNIFICANCE These results suggest a developmentally based preferential susceptibility of late-myelinating WM tracts to damage in MTLE. Brain injury in epilepsy may be due to the pathologic effects of seizures in combination with regional WM vulnerability.
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Lee CY, Bennett KM, Debbins JP. Sensitivities of statistical distribution model and diffusion kurtosis model in varying microstructural environments: a Monte Carlo study. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 230:19-26. [PMID: 23428968 DOI: 10.1016/j.jmr.2013.01.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Revised: 01/12/2013] [Accepted: 01/19/2013] [Indexed: 06/01/2023]
Abstract
The aim of this study was to investigate the microstructural sensitivity of the statistical distribution and diffusion kurtosis (DKI) models of non-monoexponential signal attenuation in the brain using diffusion-weighted MRI (DWI). We first developed a simulation of 2-D water diffusion inside simulated tissue consisting of semi-permeable cells and a variable cell size. We simulated a DWI acquisition of the signal in a volume using a pulsed gradient spin echo (PGSE) pulse sequence, and fitted the models to the simulated DWI signals using b-values up to 2500 s/mm(2). For comparison, we calculated the apparent diffusion coefficient (ADC) of the monoexponential model (b-value=1000 s/mm(2)). In separate experiments, we varied the cell size (5-10-15 μm), cell volume fraction (0.50-0.65-0.80), and membrane permeability (0.001-0.01-0.1mm/s) to study how the fitted parameters tracked simulated microstructural changes. The ADC was sensitive to all the simulated microstructural changes except the decrease in membrane permeability. The ADC increased with larger cell size, smaller cell volume fraction, and larger membrane permeability. The σstat of the statistical distribution model increased exclusively with a decrease in cell volume fraction. The Kapp of the DKI model was exclusively increased with decreased cell size and decreased with increasing membrane permeability. These results suggest that the non-monoexponential models of water diffusion have different, specific microstructural sensitivity, and a combination of the models may give insights into the microstructural underpinning of tissue pathology.
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Cheng SW, Lee LK, Lee CY. A girl with short stature and dysmorphism. INTERNATIONAL JOURNAL OF PEDIATRIC ENDOCRINOLOGY 2013. [PMCID: PMC3856503 DOI: 10.1186/1687-9856-2013-s1-p42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Lee CY, Shiea J. Gas chromatography connected to multiple channel electrospray ionization mass spectrometry for the detection of volatile organic compounds. Anal Chem 2012; 70:2757-61. [PMID: 21644791 DOI: 10.1021/ac971325+] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This work successfully connected gas chromatography (GC) to seven-channel electrospray ionization (ESI) mass spectrometry to separate and detect a mixture of volatile organic compounds. Gaseous analyte was eluted separately from a GC column and directed into the central channel of the ESI source. The analyte was protonated by ion-molecule reactions between the analyte and the ions which were generated by electrospraying the acidic solution through the outside six channels surrounding the central channel. Real-time analysis of the organic reaction involving volatile and thermally unstable compounds (dimethylhydrazine ⇌ azomethane + H(2)) was also achieved by continuously purging the air in the reaction vessel to the seven-channel ESI source.
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Lee CY, Li Z, Pipe JG, Debbins JP. Turboprop+: enhanced Turboprop diffusion-weighted imaging with a new phase correction. Magn Reson Med 2012; 70:497-503. [PMID: 23023533 DOI: 10.1002/mrm.24481] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 08/13/2012] [Accepted: 08/13/2012] [Indexed: 01/01/2023]
Abstract
Faster periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) diffusion-weighted imaging acquisitions, such as Turboprop and X-prop, remain subject to phase errors inherent to a gradient echo readout, which ultimately limits the applied turbo factor (number of gradient echoes between each pair of radiofrequency refocusing pulses) and, thus, scan time reductions. This study introduces a new phase correction to Turboprop, called Turboprop+. This technique employs calibration blades, which generate 2-D phase error maps and are rotated in accordance with the data blades, to correct phase errors arising from off-resonance and system imperfections. The results demonstrate that with a small increase in scan time for collecting calibration blades, Turboprop+ had a superior immunity to the off-resonance-related artifacts when compared to standard Turboprop and recently proposed X-prop with the high turbo factor (turbo factor = 7). Thus, low specific absorption rate and short scan time can be achieved in Turboprop+ using a high turbo factor, whereas off-resonance related artifacts are minimized.
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Lee KY, Jeon SY, Hong JW, Choi KW, Lee CY, Choi SJ, Kim JH, Song KH, Kim KH. Endothelin-1 enhances the proliferation of normal human melanocytes in a paradoxical manner from the TNF-α-inhibited condition, but tacrolimus promotes exclusively the cellular migration without proliferation: a proposed action mechanism for combination therapy of phototherapy and topical tacrolimus in vitiligo treatment. J Eur Acad Dermatol Venereol 2012; 27:609-16. [PMID: 22404745 DOI: 10.1111/j.1468-3083.2012.04498.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Vitiligo is an acquired pigmentary disorder caused by the destruction of melanocytes. Two of the major theories regarding the pathogenesis of vitiligo are the autoimmune theory and autocytotoxicity theory, but, the precise pathogenetic mechanism is still not clarified. OBJECTIVES We investigated the effects of ET-1, tacrolimus and tumour necrosis factor-α (TNF-α) on proliferation and migration of cultured normal human melanocytes (NHMs). We also sought to clarify the theoretical rationale underlying the topical tacrolimus monotherapy or tacrolimus-UV combination therapy as tools for vitiligo treatment. METHODS The effects of ET-1, tacrolimus and TNF-α on proliferation/migration of cultured NHMs were investigated by MTT assay/Boyden chamber transwell migration assay. We also examined roles of CXC-chemokine receptor II (CXCR II) and matrix metalloproteinases (MMPs) in such conditions. RESULTS ET-1 exerted a stimulatory effect on melanocyte proliferation and migration, but, tacrolimus exerted a stimulatory effect only on melanocyte migration higher than ET-1. TNF-α inhibited melanocyte proliferation in a dose-dependent manner. Paradoxically, TNF-α-pretreated NHMs exhibited an enhanced proliferative efficiency after being switched to ET-1. We found CXCRII was highly expressed in TNF-α-incubated melanocytes than the agents-free control, and ET-1 treatment after TNF-α preincubation showed the higher levels of CXCRII expression than the condition incubated with TNF-α alone. Moreover, the greater activities of MMP-2 and MMP-9 induced by tacrolimus than ET-1, reflected tacrolimus would enhance migration stimulatory effect in cultured NHMs. CONCLUSIONS Topical tacrolimus can be used an effective agent for vitiligo treatment as monotherapy, maybe due to its migration stimulatory action or TNF-α inhibitory property, and also as a component in combination therapy with UV treatment, considering the more upregulated MMPs activities are induced and the more effective migrations are feasible by itself than ET-1.
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Lee CY, Qin J, Munyard KA, Siva Subramaniam N, Wetherall JD, Stear MJ, Groth DM. Conserved haplotype blocks within the sheep MHC and low SNP heterozygosity in the Class IIa subregion. Anim Genet 2011; 43:429-37. [PMID: 22497756 DOI: 10.1111/j.1365-2052.2011.02268.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This report describes single-nucleotide polymorphisms (SNPs) in the sheep major histocompatibility complex (MHC) class II and class III regions and provides insights into the internal structure of this important genomic complex. MHC haplotypes were deduced from sheep family trios based on genotypes from 20 novel SNPs representative of the class II region and 10 previously described SNPs spanning the class III region. All 30 SNPs exhibited Hardy-Weinberg proportions in the sheep population studied. Recombination within an extended sire haplotype was observed within the class II region for 4 of 20 sheep chromosomes, thereby supporting the presence of separated IIa and IIb subregions similar to those present in cattle. SNP heterozygosity varied across the class II and III regions. One segment of the class IIa subregion manifested very low heterozygosity for several SNPs spanning approximately 120 Kbp. This feature corresponds to a subregion within the human MHC class II region previously described as a 'SNP desert' because of its paucity of SNPs. Linkage disequilibrium (LD) was reduced at the junction separating the putative class IIb and IIa subregions and also between the class IIa and the class III subregions. The latter observation is consistent with either an unmapped physical separation at this location or more likely a boundary characterized by more frequent recombination between two conserved subregions, each manifesting high within-block LD. These results identify internal blocks of loci in the sheep MHC, within which recombination is relatively rare.
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Chan AOK, But WM, Ng KL, Wong LM, Lam YY, Tiu SC, Lee KF, Lee CY, Loung PY, Berry IR, Brown R, Charlton R, Cheng CW, Ho YC, Tse WY, Shek CC. Molecular analysis of congenital adrenal hyperplasia due to 21-hydroxylase deficiency in Hong Kong Chinese patients. Steroids 2011; 76:1057-62. [PMID: 21570420 DOI: 10.1016/j.steroids.2011.04.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 04/18/2011] [Accepted: 04/20/2011] [Indexed: 11/16/2022]
Abstract
BACKGROUND Congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency (21OHD) is an autosomal recessive disorder due to mutation in the CYP21A2 gene. OBJECTIVE To elucidate the genetic basis of 21-hydroxylase-deficient CAH in Hong Kong Chinese patients. PATIENTS AND METHODS Mutational analysis of the CYP21A2 gene was performed on 35 Hong Kong Chinese patients with 21OHD using direct DNA sequencing and multiplex ligation-dependent probe amplification (MLPA). RESULTS The genetic findings of 21 male and 14 female patients are the following: c.293-13A/C>G (intron 2 splice site; 20 alleles), p.I172N (13), p.R356W (7), p.Q318X (4). A total of 20 mutant alleles contained gross deletion/conversion of all or part of the CYP21A2 gene. A novel mutation, c.1367delA (p.D456fs), was detected in one patient. One patient had only a heterozygous mutation detected. Out of 35 patients, 16 would have been incorrectly genotyped if either DNA sequencing or MLPA alone was used for molecular analysis. CONCLUSIONS The frequency of various mutations in the studied patients differs from those reported in other Asian populations. Gross deletion/conversion accounts for nearly one-third of the genetic defects. Therefore, laboratories must include methods for detecting point mutations as well as gross deletions/conversions to avoid misinterpretation of genotype. Genotyping has increasingly been proven to be a useful tool for supplementing, if not replacing, hormonal profiling for the diagnosis of 21OHD.
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Au WY, Lee V, Lau CW, Yau J, Chan D, Chan EYT, Cheung WWW, Ha SY, Kho B, Lee CY, Li RCH, Li CK, Lin SY, Ling ASC, Mak V, Sun L, Wong KHF, Wong R, Yuen HL. A synopsis of current care of thalassaemia major patients in Hong Kong. Hong Kong Med J 2011; 17:261-266. [PMID: 21813892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
OBJECTIVE To provide a synopsis of current thalassaemia major patient care in Hong Kong. DESIGN Retrospective study. SETTING All haematology units of the Hospital Authority in Hong Kong. PATIENTS All patients with thalassaemia major with regular transfusion. RESULTS To date, there were 363 thalassaemia major patients under the care of the Hospital Authority. Prenatal diagnosis has helped to reduce the number of indigenous new cases, but in recent years immigrant cases are appearing. The patients have a mean age of 23 (range, 1-52) years, and 78% of them are adults. In 2009, they received 18 782 units of blood. This accounted for 9.5% of all blood consumption from the Hong Kong Red Cross. In the past, cardiac iron overload was the major cause of death (65%) and few patients survived beyond the age of 45 years. The availability of cardiac iron assessment by magnetic resonance imaging (T2 MRI) to direct the use of oral deferiprone chelation has reduced the prevalence of heart failure and cardiac haemosiderosis, which should reduce mortality and improve life expectancy. CONCLUSION The future for thalassaemia care in Hong Kong is bright. With better transfusion and chelation, it should be possible to avoid growth and endocrine deficiencies in younger patients.
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Lee SH, Koh JS, Ryu CW, Lee CY, Lee SJ. Successful endosaccular coiling after a balloon occlusion test of the caudal channel of a double origin of the posterior inferior cerebellar artery originating from the aneurysm neck. Interv Neuroradiol 2011; 17:183-7. [PMID: 21696656 DOI: 10.1177/159101991101700207] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 03/19/2011] [Indexed: 11/17/2022] Open
Abstract
Therapeutic strategies for unruptured aneurysms in elective procedures must be carefully planned with respect to safety. We describe the case of a patient who presented with an unruptured aneurysm associated with a double origin of the posterior inferior cerebellar artery (DOPICA), a rare variant of aberrant origin. A three-dimensional rotational angiogram clearly showed that the aneurysm incorporated the origin of the DOPICA caudal channel, which was more dominant than the cranial one. The aneurysm was completely obliterated using detachable coils after a balloon occlusion test (BOT) of the caudal channel was conducted to confirm the tolerance of the patient following sudden interruption of the more prominent flow coming from the caudal channel of the DOPICA. This report affirms the need to suspect anomalies associated with a DOPICA that predispose to intracranial aneurysms and highlights the potential role of a BOT in pretreatment hemodynamic evaluations of unusual aneurysms accompanying a particular developmental anomaly.
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Li Z, Pipe JG, Lee CY, Debbins JP, Karis JP, Huo D. X-PROP: A fast and robust diffusion-weighted propeller technique. Magn Reson Med 2011; 66:341-7. [DOI: 10.1002/mrm.23033] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 04/18/2011] [Accepted: 05/07/2011] [Indexed: 11/10/2022]
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Au WY, Lee V, Kho B, Ling ASC, Chan D, Chan EYT, Chan GCF, Cheung WWW, Lau CW, Lee CY, Li RCH, Li CK, Lin SY, Mak V, Sun L, Wong KHF, Wong R, Yau J, Yuen HL. A synopsis of current haemophilia care in Hong Kong. Hong Kong Med J 2011; 17:189-194. [PMID: 21636866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
Abstract
OBJECTIVE To provide a synopsis of current haemophilia care in Hong Kong. DESIGN Retrospective survey. SETTING All haematology units of the Hospital Authority in Hong Kong. PATIENTS All patients with haemophilia A and haemophilia B. RESULTS To date, there were 222 mild-to-severe haemophilia patients (192 type A, 30 type B) under regular public care in Hong Kong (43% were considered severe, 33% moderate, and 24% mild), which gave a crude prevalence of 6.8/100 000 male inhabitants. A total of 12.8 million units of Factor VIII and 3 million units of Factor IX were prescribed annually. This amounts to 1.83 units of FVIII per capita of the population, which is comparable to that of other developed countries. Leading causes of mortality were human immunodeficiency virus-related complications (10 cases) and cerebral bleeding (2 cases). The life expectancy of patients with severe haemophilia in Hong Kong is improving; currently the oldest patient is 60 years old. Such improved survival may be due to enhanced factor availability, prompt treatment of bleeding episodes at home, safer factor products, and better antiviral treatment. Primary prophylaxis is the accepted standard of care for severe and moderate cases, and "Factor First" has become hospital policy. However, 12 patients continue to present treatment challenges, due to the documented presence of factor inhibitors. In all, 28, 100, and 14 cases respectively were positive for human immunodeficiency virus, hepatitis C virus, and hepatitis B virus; the youngest patients with the corresponding infections being 28, 13, and 22 years old. Comprehensive care with dedicated physiotherapy, surgical support, and radionucleotide synovectomy may reduce morbidity further. CONCLUSION A multidisciplinary approach can further improve the future care for haemophilia patients in Hong Kong.
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Moldowan JM, Fago FJ, Lee CY, Jacobson SR, Watt DS, Slougui NE, Jeganathan A, Young DC. Sedimentary 12-n-Propylcholestanes, Molecular Fossils Diagnostic of Marine Algae. Science 2010; 247:309-12. [PMID: 17735849 DOI: 10.1126/science.247.4940.309] [Citation(s) in RCA: 222] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Certain C(30)-steranes have been used for identifying sedimentary rocks and crude oils derived from organic matter deposited in marine environments. Analysis of a C(30)-sterane from Prudhoe Bay oil indicates that these C(30)-steranes are 24-n-propylcholestanes that apparently are derived from precursor sterols 24-n-propylidene-cholesterols and 24-n-propylcholesterol. These widely occurring sterols are biochemically synthesized in modern oceans by members of an order (Sarcinochrysidales) of chrysophyte algae. These data thus imply that C(30)-sterane biomarkers in sedimentary rocks and crude oils have a marine origin. Screening of a few organic-rich sedimentary rocks and oils from throughout the Phanerozoic suggests that these C(30)-steranes first appeared and, therefore, their source algae evolved between Early Ordovician and Devonian.
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Sivakumar S, Song YC, Park IS, Cho SH, Lee CY, Kim BG. Short-term influence of phosphate and nitrate on heavy metal accumulation by red alga Acrosorium uncinatum. ENVIRONMENTAL MONITORING AND ASSESSMENT 2010; 165:449-460. [PMID: 19421882 DOI: 10.1007/s10661-009-0958-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Accepted: 04/18/2009] [Indexed: 05/27/2023]
Abstract
Heavy metal accumulation (Cu, Zn, Ni, and Pb) in common marine macroalga, Acrosorium uncinatum under nutrient (phosphate and nitrate) enriched (experiment 1) and starved (experiment 2) conditions over a short exposure period (12 h) were examined in this study. Control was maintained in seawater contained nutrient solution without addition of metals and in seawater alone for experiment 1 and 2, respectively. Among the four metals studied, the accumulation of Zn, Ni, and Pb was considerably lower than Cu. The accumulation factor for all metals varies greatly in different nutrient concentrations, but it increases as the exposure of metal concentration decreases in both the experiments. The results of the present findings established that this macroalga is an accumulator of metals Cu, Zn, Ni, and Pb and have the potential to accumulate these metals even in a short time exposure period (12 h). Even though metal accumulation by A. uncinatum largely depends on the available concentration in the medium, nutrients like phosphate and nitrate can affect the accumulation significantly.
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Lee PI, Lee CY. Practical considerations in converting from plasma-derived to recombinant hepatitis B vaccines. BioDrugs 2010; 10:11-25. [PMID: 18020583 DOI: 10.2165/00063030-199810010-00002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Plasma-derived and recombinant vaccines have been developed to prevent hepatitis B virus infections. Both types of vaccine perform very well with respect to safety, immunogenicity and protective efficacy. The protection afforded by both types of vaccine is satisfactory for at least 5 to 10 years after vaccination, and a further booster dose is not necessary during this period. However, the plasma-derived vaccine is costly to produce and there is an unjustified but prevalent fear that it may be contaminated by potential pathogens. The supply of human plasma for production of the plasma-derived vaccine cannot be assured once use of hepatitis B vaccines becomes universal. It is therefore inevitable that the recombinant vaccine will replace the plasma-derived vaccine. If necessary, both vaccines can be used in combination. Future directions for hepatitis B vaccine development include: determination of the need for incorporation of pre-S gene products to enhance immunogenicity; defining a practical strategy to combat the problem of escape mutants after vaccination; and development of combination vaccines containing other inactivated antigens to allow complete immunisation against several diseases with a minimal number of injections.
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Subramaniam NS, Morgan EF, Lee CY, Wetherall JD, Groth DM. Polymorphism of sheep MHC Class IIb gene TAPASIN. Vet Immunol Immunopathol 2010; 137:176-80. [PMID: 20605221 DOI: 10.1016/j.vetimm.2010.04.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 04/06/2010] [Accepted: 04/26/2010] [Indexed: 11/18/2022]
Abstract
The Major Histocompatibility Complex (MHC) is one of the most gene dense regions in the genome and studies in several species have shown significant associations between the MHC and disease. The endoplasmic reticular glycoprotein, tapasin, is involved in the MHC class I antigen presentation pathway. Sheep TAPASIN is located in the class IIb region of the MHC. Sheep TAPASIN was subcloned from BAC and cosmid genomic clones and DNA sequenced. TAPASIN is 9549bp in length and encodes a protein of 447 amino acids. The structure of sheep TAPASIN was similar to other mammals and consisted of eight exons with a distinctively larger intron between exon three and four. Sheep TAPASIN gene had high sequence identity with other mammalian TAPASINs. The TAPASIN gene sequence is conserved across many mammalian species and is possibly maintained through purifying selection with the average ratio of ds/dn of 3.9. Twenty-six SNPs in sheep TAPASIN were identified.
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