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Chemistry - An Asian Journal 09/2011; 6(11):2925-30. · 4.50 Impact Factor
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ABSTRACT: We describe a surface-enhanced Raman scattering (SERS)-based sensor for the detection of human serum albumin (HSA) using gold "pearl necklace" nanomaterials (Au PNNs) as the substrate and AB 580 as the reporter.
Chemical Communications 07/2011; 47(25):7116-8. · 6.17 Impact Factor
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Chiung-Mei Chen,
Chih-Hsin Lin,
Hsueh-Fen Juan,
Fen-Ju Hu,
Ya-Chin Hsiao,
Hsin-Yi Chang,
Chih-Ying Chao, I-Cheng Chen,
Li-Ching Lee,
Tsu-Wei Wang,
Ya-Tang Chen,
Yi-Tsun Chen,
Guey-Jen Lee-Chen,
Yih-Ru Wu
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ABSTRACT: Mutations in ATP13A2 have been reported to associate with Parkinson's disease (PD). This study investigates the contribution of genetic variants in ATP13A2 to Taiwanese PD. ATP13A2 cDNA fragments from 65 early onset PD (onset <50 years) were sequenced. The identified variants were validated in a cohort of PD (n = 493) and ethnically matched controls (n = 585). A novel heterozygous G1014S, located at the conserved seventh transmembrane domain of ATP13A2 protein, was identified in an early onset PD patient, which was absent in 585 normal controls. Additionally, a reported heterozygous A746T was found in two PD patients and four controls. The clinical features and 99mTc-TRODAT-1 single photon emission computed tomography (SPECT) image of the patients carrying G1014S and A746T were similar to that of idiopathic PD. One normal control with A746T showed an asymmetric reduction of 99mT TRODAT-1 uptake in the right striatum. Under oxidative stress or apoptotic stimulus, lymphoblastoid cells carrying either A764T or G1014S showed increased caspase 3 activity compared with the controls. The rates of decay for G1014S and A746T proteins were more or less reduced in cycloheximide chase experiment. In silico modeling of G1014S exhibited a more stable feature than wild-type, and G1014S is mislocalized mainly in the intralysosomal space, which is coherent with the prediction of prohibiting N-myristoylation and membrane association. We therefore hypothesize that rare variants of ATP13A2 may contribute to PD susceptibility in Taiwan. The role played by ATP13A2 variants in PD remains to be clarified.
American Journal of Medical Genetics Part B Neuropsychiatric Genetics 06/2011; 156B(6):720-9. · 3.70 Impact Factor
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ABSTRACT: The dynamics of ClOOCl photodissociation at 248.4 and 308.4 nm was studied with photofragment translational spectroscopy. At 248.4 nm photoexcitation, the observed products are Cl, O(2), ClO and O. Product translational energy distributions P(E) and anisotropy parameters β were deduced from the measured time-of-flight spectra of the Cl, O(2), and ClO photoproducts. The photodissociation mechanisms have been discussed and compared with available theoretical results. Synchronous and fast sequential breaking of the two Cl-O bonds may both contribute to the dissociation. The relative product yields for [ClO]: [Cl] was measured to be 0.15 ± 0.04:1. The relative amounts of [O]:[O(2)] products were estimated to be 0.12:1. The branching ratios among the Cl + O(2) + Cl:ClO + ClO:ClO + Cl + O product channels were estimated to be 0.82:0.08:0.10. At 308.4 nm excitation, time-of-flight spectra of the O(2) and ClO photoproducts were recorded while there was interference from Cl(2) impurity in detecting the Cl product. Nonetheless, the observed ClO yield relative to the O(2) yield at 308.4 nm is 1.5 times that at 248.4 nm. The branching ratio between the Cl + O(2) + Cl:ClO + ClO product channels was estimated to be 0.81:0.19 at 308.4 nm. This result suggests that the ClO product may contribute a noticeable yield in the photolysis of ClOOCl at the atmospherically important wavelengths above 300 nm.
Physical Chemistry Chemical Physics 01/2011; 13(18):8195-203. · 3.57 Impact Factor
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ABSTRACT: The photolysis rate of ClOOCl is crucial in the catalytic destruction of polar stratospheric ozone. In this work, we determined the photodissociation cross section of ClOOCl at 330 nm with a molecular beam and with mass-resolved detection. The photodissociation cross section is the product of the absorption cross section and the dissociation quantum yield. We formed an effusive molecular beam of ClOOCl at a nozzle temperature of 200 or 250 K and determined its photodissociation probability by measuring the decrease of the ClOOCl intensity upon laser irradiation. By comparing with a reference molecule (Cl(2)), of which the absorption cross section and dissociation quantum yield are well-known, we determined the absolute photodissociation cross section of ClOOCl at 330 nm to be (2.31 +/- 0.11) x 10(-19) cm(2) at 200 K and (2.47 +/- 0.12) x 10(-19) cm(2) at 250 K. Impurity interference has been a well-recognized problem in conventional spectroscopic studies of ClOOCl; our mass-resolved measurement directly overcomes such a problem. This measurement of the ClOOCl photolysis cross section at 330 nm is particularly useful in constraining its atmospheric photolysis rate, which in the polar stratosphere peaks near this wavelength.
The Journal of Physical Chemistry A 04/2010; 114(14):4791-7. · 2.95 Impact Factor
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ABSTRACT: This study utilized a mass-resolved detection of ClOOCl to determine its photodissociation cross section, which is the product of the absorption cross section and dissociation quantum yield. An effusive molecular beam of ClOOCl was generated and its photodissociation probability was determined through measuring the decrease in the ClOOCl beam intensity upon laser irradiation. By comparing with a reference molecule, the absolute cross sections of ClOOCl were obtained without knowing its absolute concentration. The determined cross section of ClOOCl at 248.4 nm is (8.85±0.42)×10−18 cm2 at 200 K, significantly larger than previously reported values. The temperature dependence of the cross section was investigated at 248.4 nm in the range of 160–260 K; only a very small and negative temperature effect was observed. Because 248.4 nm is very close to the peak of the UV absorption band of ClOOCl, this work provides a new calibration point for normalizing relative absorption spectra of ClOOCl. In this work, the photodissociation cross section at 266 nm and 200 K was also reported to be (4.13±0.21)×10−18 cm2.
The Journal of Chemical Physics 11/2009; 131(17):174301-174301-6. · 3.33 Impact Factor
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ABSTRACT: Spinocerebellar ataxia type 8 (SCA8) involves bidirectional expression of CUG (ATXN8OS) and CAG (ATXN8) expansion transcripts. The pathogenesis of SCA8 is complex and the spectrum of clinical presentations is broad. In the present study, we assessed the SCA8 repeat size ranges in Taiwanese Parkinson's disease, Alzheimer's disease and atypical parkinsonism and investigated the genetic variation modulating ATXN8 expression. Thirteen large SCA8 alleles and a novel ATXN8 -62 G/A promoter SNP were found. There is a significant difference in the proportion of the individuals carrying SCA8 larger alleles in atypical parkinsonism (P = 0.044) as compared to that in the control subjects. In lymphoblastoid cells carrying SCA8 large alleles, treatment of MG-132 or staurosporine significantly increases the cell death or caspase 3 activity. Although expressed at low steady-state, ATXN8 expression level is significantly higher (P = 0.012) in cells with SCA8 large alleles than that of the control cells. The ATXN8 transcriptional activity was significantly higher in the luciferase reporter construct containing the -62G allele than that containing the -62A allele in both neuroblastoma and embryonic kidney cells. Therefore, our preliminary results suggest that ATXN8 gene -62 G/A polymorphism may be functional in modulating ATXN8 expression.
Human Genetics 03/2009; 125(4):437-44. · 5.07 Impact Factor
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ABSTRACT: Spinocerebellar ataxia type 8 (SCA8) involves the expression of an expanded CTG/CAG combined repeats (CR) from opposite strands producing CUG expansion transcripts (ataxin 8 opposite strand, ATXN8OS) and a polyglutamine expansion protein (ataxin 8, ATXN8). The pathogenesis of SCA8 is complex and the spectrum of clinical presentations is broad.
Using stably induced cell models expressing 0, 23, 88 and 157 CR, we study the role of ATXN8OS transcripts in SCA8 pathogenesis. In the absence of doxycycline, the stable ATXN8OS CR cell lines exhibit low levels of ATXN8OS expression and a repeat length-related increase in staurosporine sensitivity and in the number of annexin positive cells. A repeat length-dependent repression of ATXN8OS expression was also notable. Addition of doxycycline leads to 25 approximately 50 times more ATXN8OS RNA expression with a repeat length-dependent increase in fold of ATXN8OS RNA induction. ChIP-PCR assay using anti-dimethyl-histone H3-K9 and anti-acetyl-histone H3-K14 antibodies revealed increased H3-K9 dimethylation and reduced H3-K14 acetylation around the ATXN8OS cDNA gene in 157 CR line. The repeat length-dependent increase in induction fold is probably due to the increased RNA stability as demonstrated by monitoring ATXN8OS RNA decay in cells treated with the transcriptional inhibitor, actinomycin D. In cells stably expressing ATXN8OS, RNA FISH experiments further revealed ribonuclear foci formation in cells carrying expanded 88 and 157 CR.
The present study demonstrates that the expanded CUG-repeat tracts are toxic to human cells and may affect ATXN8OS RNA expression and stability through epigenetic and post-transcriptional mechanisms.
BMC Molecular Biology 03/2009; 10:9. · 2.86 Impact Factor
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ABSTRACT: Despite the increasing popularity of propofol for sedation in colonoscopy, the optimal regimen is still controversial. Both propofol alone and propofol in combination with meperidine are frequently used during colonoscopy, but the impact of adding meperidine has not been evaluated. This study aimed to investigate if adding meperidine to propofol offers any advantage in terms of patient tolerance, recovery time, and postcolonoscopy discomforts.
Consecutive patients admitted to the physical checkup department of our hospital were randomized to receive either meperidine plus propofol (combination group, n=100) or propofol alone (propofol group, n=100) for sedated colonoscopy. The patients' tolerance and postcolonoscopy discomforts (pain, bloating, dizziness, and nausea/vomiting) were assessed with a 0-10 visual analog scale. The recovery times were assessed with 5-minute and 10-minute Aldrete scores.
The dose of propofol was less in the combination group than the propofol group (129.80+/-37.93 mg vs. 147.90+/-47.85, mean+/-SD, P=0.003). The endoscopists, anesthetists, and nurses all rated patients' tolerance in favor of the combination group than the propofol group (mean+/-SD, endoscopists, 9.17+/-1.23 vs. 8.49+/-1.60, P=0.001; anesthetists, 9.21+/-1.08 vs. 8.63+/-1.37, P=0.001; nurses, 9.18+/-1.34 vs. 8.71+/-1.47, P=0.019, respectively). Patients in the combination group recovered earlier than the placebo group (5-min Aldrete scores: 9.48+/-1.09 vs. 9.05+/-1.32, mean+/-SD, P=0.013; short intervals to speak: 4.29+/-4.05 min vs. 6.30+/-5.22 min, P=0.003; and departure: 18.62+/-5.28 min vs. 20.28+/-5.68 min, P=0.034). There was also less abdominal bloating in the combination group after colonoscopy (1.23+/-1.79 vs. 2.19+/-2.12, mean+/-SD, P=0.004). Incidences of hypoxemia, hypotension, and overall satisfaction scores were comparable between the 2 groups.
For sedated colonoscopy, propofol in combination with meperidine is better than propofol alone in improving patients' tolerance and recovery.
Journal of clinical gastroenterology 02/2009; 43(8):753-7. · 2.21 Impact Factor
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ABSTRACT: Both of environmental and genetic factors confer vulnerability to Parkinson's disease (PD). NR4A2 (Nurr1), a member of the steroid/thyroid hormone nuclear receptor superfamily, is essential for the neurogenesis and differentiation of dopaminergic neurons in the midbrain. Brain derived neurotrophic factor (BDNF) deficiency may play a role in the pathogenesis of PD, as the surviving dopaminergic nigrostriatal neurons have reduced levels of BDNF. This study examines whether BDNF V66M (c.196 G --> A) or NR4A2 IVS6 +18insG polymorphism is associated with the risk of Taiwanese PD and the age of onset using a case-control study. The genotype or allele frequency distribution of both BDNF V66M and NR4A2 IVS6 +18insG polymorphisms was not significantly different between the cases and the controls. Neither BDNF nor NR4A2 polymorphism influences PD onset age. Notably, after stratification by sex, female individuals carrying the NR4A2 2G/2G genotype demonstrated a trend toward significant decrease in risk of developing PD (OR = 0.49, 95% CI = 0.25-0.96, P = 0.039). These results suggest that the NR4A2 IVS6 +18insG polymorphism may play a minor role in PD susceptibility among Taiwanese women.
American Journal of Medical Genetics Part B Neuropsychiatric Genetics 06/2007; 144B(4):458-62. · 3.70 Impact Factor
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ABSTRACT: We report the clinical features, electrophysiological findings and genetic characteristics of the first two Taiwanese siblings ever reported with sialidosis type I. We also provide a 10-year follow-up result. Enzymological analysis revealed a primary sialidase deficit. The back-averaged electroencephalography demonstrated myoclonic jerk-related cortical activities and the somatosensory evoked potential studies revealed giant cortical components. During the 10-year follow-up, the brain magnetic resonance images of the younger brother remained normal, whereas they showed mild cerebellar atrophy in the older sister. Macular cherry red spots were absent in both siblings. However, visual evoked potential revealed progressively prolonged latencies of P100 bilaterally, which was consistent with progressive deterioration of the siblings' visions. DNA analysis showed that the siblings had a homozygous missense point mutation c.544A-->G (Ser182Gly) in the exon 3 of the alpha-N-acetyl-neuraminidase (NEU1) gene. The mutation is predicted to cause a decreased sialidase activity but the mutant sialidase can still be targeted to the lysosomes, which may correlate with the mild clinical phenotypes and absent cherry red spots in the siblings.
Journal of the Neurological Sciences 08/2006; 247(1):65-9. · 2.35 Impact Factor
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Thrombosis Research 02/2006; 118(2):235-40. · 2.44 Impact Factor
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Chiung-Mei Chen,
Hsien-Yuan Lane,
Yih-Ru Wu,
Long-Sun Ro,
Fen-Lin Chen,
Wei-Ling Hung,
Yi-Ting Hou,
Cheng-Yueh Lin,
Shu-Yi Huang, I-Cheng Chen,
Bing-Wen Soong,
Ming-Liang Li,
Hsiu-Mei Hsieh-Li,
Ming-Tsan Su,
Guey-Jen Lee-Chen
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ABSTRACT: Schizophrenia has a complex and non-Mendelian mode of inheritance. Recently, trinucleotide repeat (TNR)-containing genes have been considered as the candidate genes predisposing to schizophrenia. The purpose of this study was to determine whether a genetic association could be observed between schizophrenia and the TNR polymorphisms within the KLHL1AS/SCA8, PPP2R2B/SCA12, and TBP/SCA17 genes. We studied 100 unrelated schizophrenia patients and 124 controls without evident neurodegenerative or psychiatric disorders. The overall allele frequency distributions of the KLHL1AS/SCA8 and PPP2R2B/SCA12 genes were not significantly different between the schizophrenic patients and the control subjects (P>0.05). The allele frequency distribution in the schizophrenic patients was significantly different from that in the controls at the TBP/SCA17 gene (P=0.0149), with an increased frequency of 36 repeats in the patients and two patients carrying 45 TNR expansions were identified. TBP/SCA17 is the TATA box binding protein gene mapped to chromosome 6q27. The study suggests that TNR expansions of the TBP/SCA17 gene may contribute to the genetic risk of schizophrenia in rare cases.
Schizophrenia Research 11/2005; 78(2-3):131-6. · 4.75 Impact Factor
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ABSTRACT: Arctium lappa Linne (burdock) is a perennial herb which is popularly cultivated as a vegetable. In order to evaluate its hepatoprotective effects, a group of rats (n = 10) was fed a liquid ethanol diet (4 g of absolute ethanol/ 80 ml of liquid basal diet) for 28 days and another group (n = 10) received a single intraperitoneal injection of 0.5 ml/kg carbon tetrachloride (CCl(4)) in order to potentiate the liver damage on the 21st day (1 day before the beginning of A. lappa treatment). Control group rats were given a liquid basal diet which did not contain absolute ethanol. When 300 mg/kg A. lappa was administered orally 3 times per day in both the 1-day and 7-day treatment groups, some biochemical and histopathological parameters were significantly altered, both in the ethanol group and the groups receiving ethanol supplemented with CCl(4). A. lappa significantly improved various pathological and biochemical parameters which were worsened by ethanol plus CCl(4)-induced liver damage, such as the ethanol plus CCl(4)-induced decreases in total cytochrome P-450 content and NADPH-cytochrome c reductase activity, increases in serum triglyceride levels and lipid peroxidation (the deleterious peroxidative and toxic malondialdehyde metabolite may be produced in quantity) and elevation of serum transaminase levels. It could even restore the glutathione content and affect the histopathological lesions. These results tended to imply that the hepatotoxicity induced by ethanol and potentiated by CCl(4) could be alleviated with 1 and 7 days of A. lappa treatment. The hepatoprotective mechanism of A. lappa could be attributed, at least in part, to its antioxidative activity, which decreases the oxidative stress of hepatocytes, or to other unknown protective mechanism(s).
Journal of Biomedical Science 01/2002; 9(5):401-9. · 2.01 Impact Factor
