Neuroprotective effect of rhaponticin against Parkinson disease: Insights from in vitro BV-2 model and in vivo MPTP-induced mice model.

Parkinson's disease (PD) is a complex neurodegenerative illness associated with the loss or damage to neurons of the dopaminergic system in the brain. Few therapeutic approaches and considerable side effects of conventional drugs necessitate a new therapeutic agent to treat patients with PD. Rhaponticin is a natural hydroxystilbene, found in herbal plants such as Rheum rhaponticum, and known to have desirable biological activity including anti-inflammatory properties. However, the neuroinflammation on rhaponticin levels has only been investigated partially so far. So, the current study explored whether rhaponticin could ameliorate the pathophysiology observed in both the in vitro microglial BV-2 cells and the in vivo (1-methyl-4-phenyl-1,2,3,5-tetrahydropyridine [MPTP])-mediated PD model. The results show rhaponticin significantly attenuated lipopolysaccharide (LPS)-mediated microglial activation by suppressing nitric oxide synthase in conjunction with abridged reactive oxygen species production together with proinflammatory mediator reduction. In vivo rhaponticin treatment improves motor impairments as well as the loss of dopaminergic neurons in MPTP-treated mice possibly through suppression via mediators of inflammation. Taken together, these results offer evidence that rhaponticin exerts anti-inflammatory effects and neuroprotection in an LPS-induced microglial model and the MPTP-induced mouse models of PD.

Hybrid graphene/GaN ultraviolet photo-transistors with high responsivity and speed.

In this work, we explore the possibility of using hybrid graphene/GaN phototransistors to get high responsivity, high speed, and large photosensitive area. The responsivity of our hybrid graphene/GaN phototransistors with a relatively large 15.2 mm2 active area reaches 361 mA/W at 10 V and the response time is ~5 ms, much better performance than traditional GaN photodetectors. This is because graphene acts as the carrier transport channel with a high mobility and greatly increases the charge collection efficiency. Our results should shed more light on the role of graphene in hybrid phototransistors and open a feasible pathway to develop large area ultraviolet photodetectors with high responsivity and high speed.

High-Efficiency Sb2Se3 Solar Cells Modified by Potassium Hydroxide.

Antimony selenide (Sb2Se3) has attracted considerable attention for its simple composition, nontoxic nature, and abundance. However, the efficiency of Sb2Se3 solar cells is limited by the low carrier concentration and high recombination rate at the interface between Sb2Se3 and the Au layer. For this paper, the KOH solution used as the etchant was used to increase the efficiency of Sb2Se3 solar cells. The KOH solution not only reacts with (etching the surface) but also diffuses inside the Sb2Se3 film. This study unexpectedly demonstrates that KOH also increases the doping density and improves the back contact (the thin Sb2O3 layer exists with the etching of the KOH solution) of Sb2Se3 solar cells. Lastly, the best power conversion efficiency of 7.16% is demonstrated with a high open-circuit voltage of 0.407 V; we believe our work can serve as a guide for further development of high-efficiency Sb2Se3 solar cells.

A regulatory variation in OPRK1, the gene encoding the kappa-opioid receptor, is associated with alcohol dependence.

Variations in OPRK1, which encodes the kappa-opioid receptor, are associated with the risk for alcohol dependence. Sequencing DNAs with higher and lower risk haplotypes revealed an insertion/deletion (indel) with a net addition of 830 bp located 1986 bp upstream of the translation start site (1389 bp upstream of the transcription start site). We demonstrated that the upstream region extending from -1647 to -10 bp or from -2312 to -10 bp (relative to the translation start site) could function as a promoter in transient transfection assays. We then determined that the presence of the indel reduced transcriptional activity by half. We used a PCR assay to genotype individuals in 219 multiplex alcohol-dependent families of European American descent for the presence or absence of this indel. Family-based association analyses detected significant evidence of association of this insertion with alcoholism; the longer allele (with the indel), which had lower expression, is associated with higher risk for alcoholism. This indel is, therefore, a functional regulatory variation likely to explain at least part of the association of OPRK1 with alcohol dependence.

Global effects of vitamin A deficiency on gene expression in rat liver: evidence for hypoandrogenism.

Vitamin A (retinol) metabolites are ligands for transcription factors that regulate many genes. The liver is the main storage depot for retinol and plays a role in vitamin A homeostasis. To better understand the effects of vitamin A deficiency on liver gene expression, we produced retinol deficiency in male rats by feeding a diet low in retinol for 53 days after weaning and examined the effects on gene expression in liver using Affymetrix oligonucleotide microarrays. We detected expression of 41% of the 8799 probe sets represented on the RGU-34A GeneChips. Vitamin A deficiency resulted in major changes in liver gene expression: 805 genes (22% of all genes detected) differed at P

Natural haplotypes in the regulatory sequences affect human alcohol dehydrogenase 1C (ADH1C) gene expression.

Human alcohol dehydrogenases (ADHs) play important roles in metabolizing alcohol, and several lines of evidence suggest that variations in ADH genes affect the risk for alcoholism. Differences in regulatory sequences could affect the expression of ADH genes and thereby modify the risk for alcoholism. To explore this idea, we sequenced regulatory regions upstream of ADH1C and identified 13 polymorphisms, including one 66-base pair (bp) insertion/deletion (in/del), one 5-bp variation, and 11 single nucleotide polymorphisms (SNPs), eight of which were newly identified. We examined the effects of naturally occurring haplotypes on gene expression. The 66-bp in/del alone did not change promoter activity, but when it was combined with three other SNP alleles, a twofold difference in transcription activity was observed in transient transfection assays in H4IIE-C3 cells. These data imply that there are interactions among polymorphisms in the cis-acting elements, and highlight the importance of studying regulatory polymorphisms within the context of their naturally occurring haplotypes. We also demonstrated tissue specificity in cis-acting elements by comparing gene expression in H4IIE-C3 and HeLa cells.

Alternative splicing and promoter use in the human GABRA2 gene.

GABA(A) receptors mediate the majority of the fast synaptic inhibition in the mammalian brain. They are the targets of several important drugs, including benzodiazepines, which are used as anxiolytics, sedatives, anti-convulsants, and in the treatment of alcohol withdrawal symptoms. Non-coding variations in GABRA2, the gene encoding the alpha2 subunit, are associated with the risk for alcoholism, suggesting that regulatory differences are important. GABRA2 mRNAs from whole human brain and from three brain regions were examined for evidence of alternative splicing using reverse transcription-PCR and DNA sequencing. A complex pattern of alternative splicing and alternative promoter use of the human GABRA2 mRNA was demonstrated. There are four major isoforms consisting of combinations of two alternative 5' and 3' exons, as well as minor isoforms lacking exon 4 or exon 8. The alternative 5' exons each lie downstream of a functional promoter sequence, as shown by transient transfection assays. The promoter activities of naturally occurring haplotypes differed, indicating genetic differences in gene expression.

Evaluation of clinical features of elderly epilepsy in China.

Recent data indicate that the prevalence and incidence of epilepsy are high among the elderly, many of whom will have concomitant neurodegenerative, cerebrovascular, or neoplastic disease. The aim of this study is to evaluate the clinical characteristics of elderly patients with epilepsy in China. We retrospectively reviewed the clinical records of 104 outpatients over 50 years of age (average: 63.8 years). The results showed that in the total 104 outpatients, 53 men and 51 women were studied. Twenty-seven (26.0%) patients had idiopathic epilepsy syndromes, and 15 (14.4%) patients were considered cryptogenic. Sixty-two (59.6%) patients had remote symptomatic epilepsy. According to the known etiological factors, cerebrovascular disease (53.2%) is the most common underlying cause, followed by craniocerebral trauma (16.1%), primary or metastatic neoplastic disease (16.1%), and others (14.5%). The most common type of seizure in the group studied was partial seizures (51.9%), followed by generalized seizures (37.5%). Forty-three patients (41.3%) were used combination medication and 61 patients (58.7%) were used single medication. In conclusions, this study provides important data for clinical and research purposes in China. Further research is indicated to confirm the clinical findings of the elderly people with epilepsy by a larger epidemiological study.

Laser-induced fluorescence detection on multichannel electrophoretic microchips using microprocessor-embedded acousto-optic laser beam scanning.

An improved method for fast scanning and fluorescence detection on multimicrochannel microchips is presented using acousto-optic-deflection-driven laser-beam scanning. A microprocessor embedded subsystem used in conjunction with LabView program as the human-machine interface for control of laser-beam scanning and data preprocessing allowed faster scanning and addressing speeds to be attained and improved attenuation calibration and the data sampling speed. This system allows for flexible, high-resolution fluorescence detection for multimicrochannel electrophoresis in a manner that can be applied to a number of high-throughput analysis applications. Incorporating an F-theta focusing lens into the optical set-up allowed for a laser spot as small as 10 microm to accurately be addressed to the center of microchannels. With this spot size, it will be possible to further increase the channel density in the scanning range without encountering crosstalk. Using a six-channel microchip (four separation channels, two alignment channels), the simultaneous separation and fluorescence detection of amino acids and DNA digest samples in four channels is illustrated. User-friendly interpretation of the separation data is facilitated not only by a peak alignment/normalization routine developed within the software, but also through improved signal-to-noise ratios obtained through exploitation of signal processing.

Antiepileptic drug-induced skin reactions: a retrospective study and analysis in 3793 Chinese patients with epilepsy.

OBJECTIVE: To evaluate the incidence and clinical characteristics of AED-related skin reactions, along with factors influencing these reactions, in a sample of 3793 Chinese epileptic patients. MATERIALS AND METHODS: Between February 1999 and April 2010, consecutive patients with epilepsy were studied retrospectively. A detailed survey of each patient's medical records concerning all treatment with AEDs was performed. RESULTS: A total of 3793 (2323 male) Chinese epileptic patients taking at least one AED were investigated. Overall, 137/3793 (3.61%) patients experienced a skin reaction following one out of 11 different of AEDs marketed in China. In this study, we found skin reactions from carbamazepine (CBZ) in 3.80% of exposures, from lamotrigine (LTG) in 11.11%, and from oxcarbazepine (OXC) in 8.92%. Skin reactions developed significantly more often in females than in males (4.97% vs. 2.76%), and a logistic regression analysis confirmed female gender as a factor linked to AED-related rashes (OR=1.84, p<0.001). LTG-induced rashes were more frequent in girls under age 13 than in women over the age of 13 (p<0.05). CONCLUSION: The incidence of skin reactions was somewhat higher for LTG, CBZ, and OXC, whereas valproic acid, levetiracetam, and topiramate were rarely associated with skin reactions. Caution should be exercised when prescribing certain AEDs, particularly CBZ, LTG, and OXC. Females have a higher risk for skin reactions compared to males, though further investigation is needed to discern the underlying mechanisms.

MRI sequence findings in sporadic Creutzfeldt-Jakob disease.

MRI has had an important role in the diagnosis of Creutzfeldt-Jakob disease (CJD). The aim of our study was to compare the efficacy of different MRI sequences among six biopsy-proven patients with sporadic CJD (sCJD) and seven patients with probable sCJD. These 13 patients with CJD aged from 36 years to 75 years (mean age: 55.5 years) were evaluated with T1-weighted, T2-weighted, and fluid-attenuated inversion recovery (FLAIR) MRI and diffusion-weighted imaging (DWI). The characteristic MRI lesion pattern was found to be bilateral, symmetric and hyperintense signal changes in the basal ganglia and cortical regions. Two major lesion patterns were identified in all patients involving the cortex and basal ganglia. No signal abnormality was found in the thalamus. We found lesions in the cortex and basal ganglia in 7/13 patients (54%), isolated cortical involvement in 2/13 patients (15%), and isolated basal ganglia lesions in 4/13 patients (31%). The cortical involvement was widespread (in at least two regions) and usually included the frontal or occipital lobes (9/13, 69%) on DWI. Only one patient showed moderate high-signal intensity in the basal ganglia on T2-weighted MRI. T1-weighted MRI revealed no signal intensity abnormalities. We conclude that high signal changes in the basal ganglia and cerebral cortex on FLAIR and DWI are useful in the diagnosis of sCJD. Isolated cortical involvement on DWI and FLAIR should lead to a suspicion of CJD. DWI is the most sensitive MRI technique in the diagnosis of CJD, which supports an amendment to the clinical diagnostic criteria for sCJD to include findings from MRI.

Primary intracerebral Rosai-Dorfman disease.

Sinus histiocytosis with massive lymphadenopathy (SHML), also known as Rosai-Dorfman disease (RDD), is an idiopathic histiocytic disorder of lymph nodes and extranodal sites. Central nervous system (CNS) manifestations, particularly in the absence of nodal disease, are rare. Intracranial RDD clinically and radiologically resembles meningioma, and histologic examination is essential for a definitive diagnosis. We report four patients with RDD primary to the CNS without evidence of other sites of involvement, review the literature, and discuss the clinical manifestations, pathology, treatment and outcome.

Cross-reactivity of skin rashes with current antiepileptic drugs in Chinese population.

OBJECTIVE: Due to less experience with the cross-reactivity of antiepileptic drugs (AEDs) in Chinese population, we surveyed the rates of cross- reactivity of rash among commonly used AEDs in Chinese patients with epilepsy, particularly between the traditional and the new compounds. METHODS: We have retrospectively reviewed the medical records concerning all antiepileptic drug treatment in consecutive Chinese patients with epilepsy in our center. The incidence of AED-related rash was determined in 3793 outpatients, taking at least one of the AEDs-carbamazepine (CBZ), valproic acid (VPA), phenytoin (PHT), phenobarbital (PB), clonazepam (CZP), oxcarbazepine (OXC), lamotrigine (LTG), gabapentin (GBP), topiramate (TPM), levetiracetam (LEV) and traditional Chinese medicine (TCM). We have performed telephone interviews among all patients with AEDs-related rash. We described the clinical characteristics of the 18 patients with cross-reactivity involving the AEDs, and the cross- reactivity pattern for CBZ, PHT, OXC, and LTG. RESULTS: A total of 3.61% (137/3793) of patients experienced a skin rash to at least one AEDs, of these patients, 73 (53.28%) were female and 64 were males (46.72%). While 18 patients had a rash to two or more AEDs. Of patients who had a rash to CBZ and were also prescribed PHT (n = 17), 52.9% had a rash to PHT (abbreviated as CBZ → PHT: 52.9%); of patients who had a rash to PHT and were also prescribed CBZ (n = 13), rate of rash was 69.2% (i.e., PHT → CBZ: 69.2%). Other results: CBZ → LTG: 25% (n = 16); LTG → CBZ: 44.4% (n = 9); CBZ→ OXC: 40% (n = 10); OXC → CBZ: 66.7% (n = 6); LTG → PHT: 20% (n = 5); PHT → LTG: 16.7% (n = 6); OXC → LTG: 25% (n=4); LTG → OXC: 33.3% (n = 3); OXC → PHT: 25% (n = 4); PHT → OXC: 16.7% (n = 6). There was a highly significant mutual risk for cross- reactivity for CBZ and PHT, and OXC, and LTG (p<0.001), mutual risk reached statistical significance for LTG and CBZ (p = 0.01). CONCLUSION: Cross-reactivity rates between certain AEDs are high, especially when involving carbamazepine and phenytoin. There were also too few patients with rash to reach definitely conclusions about possible cross-reactivity. Larger numbers of patients would be needed to assess this and the mechanism. Caution should be exercised when prescribing certain AEDs (especially CBZ and PHT, but also OXC, and LTG).

Differential regulation of the alcohol dehydrogenase 1B (ADH1B) and ADH1C genes by DNA methylation and histone deacetylation.

BACKGROUND: The human class I alcohol dehydrogenase (ADH) genes (ADH1A, ADH1B, and ADH1C) differ in expression during development and in various tissues. They are repressed in the HepG2 human hepatoma cell line. We hypothesized that epigenetic modifications play a role in this repression and that class I ADH gene expression would be enhanced upon global inhibition of DNA methylation and histone deacetylation. METHODS: Southern blotting was used to assess the methylation status of each class I ADH gene. HepG2 and HeLa cells were treated with either the DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-aza-dC), the histone deacetylase inhibitor Trichostatin A (TSA), or both in combination, and class I ADH gene expression was analyzed. Chromatin immunoprecipitation assays were performed to analyze histone H3 acetylation. Transient transfections and gel mobility shift assays were used to analyze the role that methylation plays in inhibiting transcription factor binding and promoter function. RESULTS: We show that the upstream regions of ADH1A, ADH1B, and ADH1C are methylated in HepG2 cells. 5-Aza-2'-deoxycytidine treatment enhanced expression of both ADH1B and ADH1C. Trichostatin A treatment elevated expression of ADH1C. ADH1A expression was not stimulated by either 5-aza-dC or TSA. H3 histones associated with a methylated upstream region of ADH1B were hyperacetylated in TSA-treated, but not in 5-aza-dC-treated, HepG2 cells. A methylated upstream region of ADH1C achieved histone H3 hyperacetylation upon either 5-aza-dC or TSA treatment. Methylation of the ADH1B proximal promoter in vitro decreased its activity to 54% and inhibited the binding of the upstream stimulatory factor. CONCLUSIONS: These findings suggest that the class I ADH genes are regulated by epigenetic mechanisms in human hepatoma cells. The temporal and tissue-specific expression of these genes may in part result from differences in epigenetic modifications and the availability of key transcription factors.

Association of alcohol dehydrogenase genes with alcohol dependence: a comprehensive analysis.

Linkage evidence indicated that gene(s) located on chromosome 4q, in the region of the alcohol dehydrogenase (ADH) genes, affected risk for alcoholism. We genotyped 110 single nucleotide polymorphisms (SNPs) across the seven ADH genes and analyzed their association with alcoholism in a set of families with multiple alcoholic members, using the pedigree disequilibrium test. There was strong evidence that variations in ADH4 are associated with alcoholism: 12 SNPs were significantly associated. The region of strongest association ran from intron 1 to 19.5 kb beyond the 3' end of the gene. Haplotype tag SNPs were selected for the block in the ADH4 gene that provided evidence of association and subsequently used in association analysis; the haplotype was significantly associated with alcoholism (P=0.01) There was weaker evidence that variations in ADH1A and ADH1B might also play a role in modifying risk. Among African-Americans, there was evidence that the ADH1B*3 allele was protective.

High-throughput single-strand conformation polymorphism analysis on a microfabricated capillary array electrophoresis device.

A high-density 384-lane microfabricated capillary array electrophoresis device is evaluated for high-throughput single-strand conformation polymorphism (SSCP) analysis. A delayed back bias direct electrokinetic injection scheme is used to provide better than 10-bp resolution with an 8.0-cm effective separation length. Separation of a HaeIII digest of PhiX174 yielded theoretical plate numbers of 4.0 x 10(6). Using 5% PDMA containing 10% glycerol and 15% urea, 21 single-nucleotide polymorphisms (SNPs) from HFE, MYL2, MYL3, and MYH7 genes associated with hereditary hemochromatosis (HHC) and hereditary hypertrophic cardiomyopathy (HCM) are discriminated at two running temperatures (25 degrees C and 40 degrees C), providing 100% sensitivity. The data in this study demonstrate that the 384-lane microCAE device provides the resolution and detection sensitivity required for SSCP analysis, showing its potential for ultrahigh-throughput mutation detection.

Hydroxyethylcellulose as an effective polymer network for DNA analysis in uncoated glass microchips: optimization and application to mutation detection via heteroduplex analysis.

The nature of the sieving matrix for DNA fragment separation is of immense importance in capillary and microchip electrophoresis. The chemical nature of the surface of the capillary or microchannel wall is equally as important, particularly with DNA electrophoresis where a substantial electroosmotic flow (EOF) may be detrimental to the separation. Although DNA analysis has been carried out successfully in both coated and uncoated capillaries, analysis of unpurified polymerase chain reaction products has been carried out primarily with covalently coated surfaces, especially with microchip electrophoresis. In this report, double-stranded (ds) DNA fragment analysis using hydroxyethylcellulose (HEC) buffered in 1xTris-borate-EDTA is demonstrated both in uncoated capillaries and in microchips. EOF was suppressed 20% in the presence of 1.5% HEC, and the effectiveness of HEC as a polymer for dsDNA fragment analysis was dependent on the pH, with pH 8.6 being optimal. Using separation efficiency (number of theoretical plates) and resolution to gauge the effectiveness of a variety of polymers for the capillary separation of dsDNA fragments in the size range 60-587bp, HEC was found to be comparable in performance to polydimethylacrylamide (PDMA), and superior to linear polyacrylamide and polyethylene oxide for DNA analysis. With respect to longevity and robust performance, HEC could be used effectively in an uncoated capillary for more than 40 runs and for more than 90 runs (without replenishing the polymer) in an uncoated microchip. Application of the optimized HEC conditions is demonstrated through its ability to facilitate heteroduplex analysis.

Microfabricated 384-lane capillary array electrophoresis bioanalyzer for ultrahigh-throughput genetic analysis.

A microfabricated 384-lane capillary array electrophoresis device is developed and utilized for massively parallel genetic analysis. The 384 capillary lanes, arrayed radially about the center of a 200-mm-diameter glass substrate sandwich, are constructed using scalable microfabrication techniques derived from the semiconductor industry. Samples are loaded into reservoirs on the perimeter of the wafer, separated on the 8-cm-long poly(dimethylacrylamide) gel-filled channels, and detected with a four-color rotary confocal fluorescence scanner. The performance and throughput of this bioanalyzer are demonstrated by simultaneous genotyping 384 individuals for the common hemochromatosis-linked H63D mutation in the human HFE gene in only 325 s. This lab-on-a-chip device thoroughly exploits the power of microfabrication to produce high-density capillary electrophoresis arrays and to use them for high-throughput bioanalysis.

Variations in GABRA2, encoding the alpha 2 subunit of the GABA(A) receptor, are associated with alcohol dependence and with brain oscillations.

Alcoholism is a complex disease with both genetic and environmental risk factors. To identify genes that affect the risk for alcoholism, we systematically ascertained and carefully assessed individuals in families with multiple alcoholics. Linkage and association analyses suggested that a region of chromosome 4p contained genes affecting a quantitative endophenotype, brain oscillations in the beta frequency range (13-28 Hz), and the risk for alcoholism. To identify the individual genes that affect these phenotypes, we performed linkage disequilibrium analyses of 69 single-nucleotide polymorphism (SNPs) within a cluster of four GABA(A) receptor genes, GABRG1, GABRA2, GABRA4, and GABRB1, at the center of the linked region. GABA(A) receptors mediate important effects of alcohol and also modulate beta frequencies. Thirty-one SNPs in GABRA2, but only 1 of the 20 SNPs in the flanking genes, showed significant association with alcoholism. Twenty-five of the GABRA2 SNPs, but only one of the SNPs in the flanking genes, were associated with the brain oscillations in the beta frequency. The region of strongest association with alcohol dependence extended from intron 3 past the 3' end of GABRA2; all 43 of the consecutive three-SNP haplotypes in this region of GABRA2 were highly significant. A three-SNP haplotype was associated with alcoholism, with P=.000000022. No coding differences were found between the high-risk and low-risk haplotypes, suggesting that the effect is mediated through gene regulation. The very strong association of GABRA2 with both alcohol dependence and the beta frequency of the electroencephalogram, combined with biological evidence for a role of this gene in both phenotypes, suggest that GABRA2 might influence susceptibility to alcohol dependence by modulating the level of neural excitation.