WITHDRAWN:Sustained release property of PLGA-collagen nerve conduit in vitro.
Ahead of Print article withdrawn by publisher.
Journal Article↗
Biomedical subjects
Li Yang
Publications and source records attributed to Li Yang.
Comparison of annular wavefront interpretation with Zernike circle polynomials and annular polynomials.
A general wavefront fitting procedure with Zernike annular polynomials for circular and annular pupils is proposed. For interferometric data of typical annular wavefronts with smaller and larger obscuration ratios, the results fitted with Zernike annular polynomials are compared with those of Zernike circle polynomials. Data are provided demonstrating that the annular wavefront expressed with Zernike annular polynomials is more accurate and meaningful for the decomposition of aberrations, the calculation of Seidel aberrations, and the removal of misalignments in interferometry. The primary limitations of current interferogram reduction software with Zernike circle polynomials in analyzing wavefronts of annular pupils are further illustrated, and some reasonable explanations are provided. It is suggested that the use of orthogonal basis functions on the pupils of the wavefronts analyzed is more appropriate.
Journal Article↗
Theoretical study on the optoelectronic properties of electron-withdrawing substituted diethynylfluorenyl gold(I) complexes.
We report on a quantum-chemical study of the electronic and optical properties of gold(I) complex AuTFT (1) and its electron-withdrawing substitutents, AuTFOT (2) and AuTFCNT (3) [where TFT = diethynylfluorenyl, TFOT = diethynylfluorenone and TFCNT = diethynyl-(9-(dicyanomethylene)fluorene)]. Our theoretical calculations indicate that for all systems the reorganization energies of electron and hole are in the same order of magnitude and similar to those of the well-known electrontransport material Alq3. The substitution of -CO and -C(CN)2 for -CH in AuTFT significantly decreases the bond length alternation and increases the electron affinity, which would effectively lower the energy barrier for electron injection from cathode and thus qualify AuTFOT (2) and AuTFCNT (3) as candidates for the electron transport layer (ETL) in light-emitting diodes (LEDs). The lowest lying excited-states of gold(I) diethynylfluorenyl derivatives have been studied by the singles configuration interaction (CIS) method and time-dependent density functional method (TDDFT). It is found that the electron-withdrawing substitutions evidently decrease the energy gap, leading to a remarkable red shift in transition energy and transformation in the direction of charge transfer. Our research is important in the development of new functional materials for the design of LEDs with enhanced performance.
Journal Article↗
Herpes simplex virus type 2 (HSV-2) establishes latent infection in a different population of ganglionic neurons than HSV-1: role of latency-associated transcripts.
Herpes simplex virus type 1 (HSV-1) and HSV-2 cause very similar acute infections but differ in their abilities to reactivate from trigeminal and dorsal root ganglia. To investigate differences in patterns of viral infection, we colabeled murine sensory ganglia for evidence of HSV infection and for the sensory neuron marker A5 or KH10. During acute infection, 7 to 10% of HSV-1 or HSV-2 antigen-positive neurons were A5 positive and 13 to 16% were KH10 positive, suggesting that both viruses reach each type of neuron in a manner proportional to their representation in uninfected ganglia. In murine trigeminal ganglia harvested during HSV latency, 25% of HSV-1 latency-associated transcript (LAT)- and 4% of HSV-2 LAT-expressing neurons were A5 positive, while 12% of HSV-1 LAT- and 42% of HSV-2 LAT-expressing neurons were KH10 positive. A similar difference was observed in murine dorsal root ganglia. These differences could not be attributed to differences in LAT expression levels in A5- versus KH10-positive neurons. Thus, HSV-1 demonstrated a preference for the establishment of latency in A5-positive neurons, while HSV-2 demonstrated a preference for the establishment of latency in KH10-positive neurons. A chimeric HSV-2 mutant that expresses the HSV-1 LAT exhibited an HSV-1 phenotype, preferentially establishing latency in A5-positive neurons. These data imply that the HSV-1 and HSV-2 LAT regions influence the ability of virus to establish latency in different neuronal subtypes. That the same chimeric virus has a characteristic HSV-1 reactivation phenotype further suggests that LAT-influenced establishment of latency in specific neuronal subtypes could be an important part of the mechanism by which LAT influences viral reactivation phenotypes.
Animals↗
The serotonin 5-HT1D receptor gene and attention-deficit hyperactivity disorder in Chinese Han subjects.
Attention-deficit/hyperactivity disorder (ADHD) is a heritable disease. Serotonin is one of the neurotransmitters involved in the etiology of ADHD. Serotonin-1D receptors are autoreceptors which can regulate the release of serotonin in brain, so the HTR1D gene may be predisposing. The current study genotyped two variants of HTR1D gene in 272 ADHD trios of Chinese ethnicity, that is 1350T > C in the coding region and 1236A > G in 3'-UTR by the use of transmission disequilibrium test (TDT). The A allele of the 1236A > G polymorphism exhibited both a trend toward preferential transmission to ADHD probands (chi2 = 3.815, P = 0.051) and a significant preferential transmission to probands of ADHDC (chi2 = 4.198, P = 0.040). Additional polymorphisms in this gene need to be studied further.
Asian People↗
Possible mechanisms explaining the tendency towards interstitial fibrosis in aristolochic acid-induced acute tubular necrosis.
BACKGROUND: We explored possible mechanisms responsible for the inability of plerosis and the tendency towards fibrosis in aristolochic acid-induced acute tubular necrosis (AA-ATN). METHODS: Renal biopsy tissues from eight AA-ATN cases were examined. Tubulointerstitial injury was semiquantitatively assessed. Immunohistochemical steptavidin-peroxide (SP) methods were used to determine the expressions of proliferating cell nuclear antigen (PCNA), epidermal growth factor (EGF), alpha-smooth muscle actin (alpha-SMA), transforming growth factor-beta(1) (TGF-beta(1)), connecting tissue growth factor (CTGF), fibronectin (FN), collagen III (Col-III), collagen IV (Col-IV), factor VIII-related antigen (VIII-Ag) and vascular endothelial growth factor (VEGF). Ultramicrostructure of endothelial cells and basement membrane of peritubular capillaries (PTC) and glomerular capillaries was detected by electron microscopy. These data were compared with that of 9 cases of antibiotic-induced ATN (a-ATN) and 10 cases of minor mesangioproliferative non-IgA glomerulonephritis, which served as a control group. RESULTS: In AA-ATN, almost no renal tubular epithelial cells (RTEC) were PCNA-positive (0.01 +/- 0.02%), and EGF expression was considerably decreased (9.55 +/- 7.22%). This was in contrast with the highly active tubular proliferation (PCNA-positive RTEC 47.25 +/- 19.33%, P < 0.05) and increased EGF expression in a-ATN (64.38 +/- 19.22%, P < 0.05). The expression of alpha-SMA in the tubulointerstitium, the number of interstitial TGF-beta(1)-positive cells and the CTGF-positive interstitial area were all increased in both a-ATN and AA-ATN, with no obvious differences between the two groups. With respect to extracellular matrix (ECM) deposition, FN, Col-III and Col-IV were detected only in the interstitium of AA-ATN. PTC lumina were decreased in size and misshapen in the AA-ATN group. Also in AA-ATN, the luminal wall was partially disrupted, endothelial cells were swollen and vacuoles and granules were found in the cell plasma. Parts of the endothelial cells were detached from the tubular basement membrane. CONCLUSION: The strong ability for RTEC repair after acute injury was severely diminished in AA-ATN, and this effect may be partly due to reduced EGF expression. Anti-fibrosis mechanisms may also be impaired in AA-ATN, since both a-ATN and AA-ATN had increased expression of TGF-beta(1) and CTGF, whereas only the latter group showed ECM deposition. Injury and loss of PTC occurred in AA-ATN, and this may contribute to tubulointerstitial damage, the inability of plerosis and the tendency towards fibrosis in this disease.
Actins↗
Excitatory amino acid receptor-mediated responses in periaqueductal gray neurons are increased during ethanol withdrawal.
The ventrolateral periaqueductal gray (PAG) is critical for propagation in the neuronal network for ethanol withdrawal (ETX) seizures, and ethanol is known to alter glutamate effects. This study evaluated changes in glutamate antagonist effects on PAG neurophysiology in brain slices from rats treated with ethanol in vivo. Spontaneous action potentials were rare in control PAG neurons but common during ETX. Spontaneous excitatory postsynaptic potential (EPSP) frequency was increased during ETX, and an AMPA antagonist, 6,7-dinitroquinoxaline-2,3-dione (DNQX) was more effective in suppressing this activity than an NMDA antagonist, 2-amino-7-phosphonoheptanoate (AP7). EPSPs evoked by stimulation of dorsolateral PAG were decreased by AP7 or DNQX in ETX and control neurons. EPSPs of ETX neurons were significantly less sensitive than controls to blockade by AP7 and DNQX. Paired-pulse facilitation of EPSPs was significantly increased during ETX, but paired-pulse inhibition occurred in controls. Thus, PAG hyperexcitability during ETX results from alterations of both NMDA and AMPA receptor-mediated neurotransmission, which may contribute importantly to ETX seizures. These results differ from previous findings in the seizure-initiating site for ETX seizures, inferior colliculus (IC), where NMDA receptor-mediated mechanisms dominate excitability increases during ETX. This dichotomy may be related to the different role played by IC and PAG in the ETX seizure network.
Action Potentials↗
T regulatory and primed uncommitted CD4 T cells express CD73, which suppresses effector CD4 T cells by converting 5'-adenosine monophosphate to adenosine.
CD73 (5'-ectonucleotidase) is expressed by two distinct mouse CD4 T cell populations: CD25+ (FoxP3+) T regulatory (Treg) cells that suppress T cell proliferation but do not secrete IL-2, and CD25- uncommitted primed precursor Th (Thpp) cells that secrete IL-2 but do not suppress in standard Treg suppressor assays. CD73 on both Treg and Thpp cells converted extracellular 5'-AMP to adenosine. Adenosine suppressed proliferation and cytokine secretion of Th1 and Th2 effector cells, even when target cells were activated by anti-CD3 and anti-CD28. This represents an additional suppressive mechanism of Treg cells and a previously unrecognized suppressive activity of Thpp cells. Infiltration of either Treg or Thpp cells at inflammatory sites could potentially convert 5'-AMP generated by neutrophils or dying cells into the anti-inflammatory mediator adenosine, thus dampening excessive immune reactions.
5'-Nucleotidase↗
[Multi-slice computed tomography of myocardial bridge and mural coronary artery and clinical significance thereof].
OBJECTIVE: To investigate the diagnosis of myocardial bridge and mural coronary artery (MB-MCA) with multi-slice computed tomography (MSCT) and clinical significance thereof. METHODS: 900 patients suspected as with coronary artery disease (CHD) underwent 64-slice computed tomography performed by 3 radiologists independently. When consistency was obtained among the independent interpretations of the tomogram among them the diagnosis of MB-MCA could be confirmed. The length of MCA and thickness of MB were measured, and the situation of the nearby arteries were observed and recorded. Based on the above mentioned 3 items the reference scoring criteria were established. RESULTS: 180 sites of MB-NCA were found in 167 (18.56%) of the 900 patients, 112 males and 55 females, aged 54.46 (33 - 84). 167 of the 180 sites of MB-MCA were located on the LAD (92.7%). MCA could be covered by MB in a form of semi-circularity (63.89%, 115/180) or circularity (36.11%, 65/180) The length of MCA was 18.7 mm +/- 10.2 mm, and the thickness of MB was 1.7 mm +/- 1.2 mm. 70% of the arteries proximal and/or distal to the MB-MCA were tortuous. Length of MCA < 10 mm, half-surrounding of MB, and smoothness of the proximal and distant vessels were scored as 1; length of MCA of 10 approximately 20 mm, thickness of MB < 1 mm, and tortuousness of the unilateral proximal or distant vessel were scored as 2; and length of MCA > 20 mm, thickness of MB > 1 mm, and tortuousness of the bilateral proximal and distant vessels were scored as 3. Coronary atherosclerosis was found in 88 of the 167 patients (52.69%). No significant correlation was found between coronary atherosclerosis and MB-MCA grade (u = 1.234, P > 0.05). CONCLUSION: Sixty-four-slice CT can be used to confirm the presence of MB = MCA and the morphology of coronary artery with MB-MCA. Coronary atherosclerosis is not significantly correlated with MB-MCA grade.
Adult↗
[Association between serotonin 1D gene polymorphisms and attention deficit hyperactivity disorder comorbid or not comorbid disruptive behavior disorder].
OBJECTIVE: To investigate the relationship between two HTR1D gene polymorphisms, that is 1350T > C and 1236A > G polymorphisms, and attention deficit hyperactivity disorder (ADHD) comorbid or not comorbid disruptive behavior disorder (DBD). METHODS: Blood samples were taken from 90 trios with probands of ADHD comrbid DBD and 182 trios with probands of ADHD not comorbid DBD. DNA was extracted. 1350T > C and 1236A > G were genotyped by restriction fragment length polymorphism analysis. Transmit/disequilibrium test and haplotype analysis were used to test the association of the two polymorphisms of HTR1D gene and ADHD comorbid or not comorbid disruptive behavior disorder (DBD) separately. RESULTS: 1350T allele(chi2 = 3.67, P = 0.055)and G/T haplotype(chi2 = 3.84, P = 0.050)were overtransmitted, while 1350C allele(chi2 = 3.67, P = 0.055) and G/C haplotype(chi2 = 5.22, P = 0.022)were undertransmitted to probands of ADHD with DBD. No biased transmission of any allele and haplotype was found in families with probands of ADHD without DBD. CONCLUSION: ADHD comorbid or not comorbid DBD are different at the level of HTR1D gene polymrohisms of 1350T > C and 1236A > G. The current results indicate that ADHD with DBD has more heritable backgrounds when compared with ADHD without DBD.
Adolescent↗
Analysis of the dermatophyte Trichophyton rubrum expressed sequence tags.
BACKGROUND: Dermatophytes are the primary causative agent of dermatophytoses, a disease that affects billions of individuals worldwide. Trichophyton rubrum is the most common of the superficial fungi. Although T. rubrum is a recognized pathogen for humans, little is known about how its transcriptional pattern is related to development of the fungus and establishment of disease. It is therefore necessary to identify genes whose expression is relevant to growth, metabolism and virulence of T. rubrum. RESULTS: We generated 10 cDNA libraries covering nearly the entire growth phase and used them to isolate 11,085 unique expressed sequence tags (ESTs), including 3,816 contigs and 7,269 singletons. Comparisons with the GenBank non-redundant (NR) protein database revealed putative functions or matched homologs from other organisms for 7,764 (70%) of the ESTs. The remaining 3,321 (30%) of ESTs were only weakly similar or not similar to known sequences, suggesting that these ESTs represent novel genes. CONCLUSION: The present data provide a comprehensive view of fungal physiological processes including metabolism, sexual and asexual growth cycles, signal transduction and pathogenic mechanisms.
Arthrodermataceae↗
Large-scale cis-element detection by analysis of correlated expression and sequence conservation between Arabidopsis and Brassica oleracea.
The rapidly increasing amount of plant genomic sequences allows for the detection of cis-elements through comparative methods. In addition, large-scale gene expression data for Arabidopsis (Arabidopsis thaliana) have recently become available. Coexpression and evolutionarily conserved sequences are criteria widely used to identify shared cis-regulatory elements. In our study, we employ an integrated approach to combine two sources of information, coexpression and sequence conservation. Best-candidate orthologous promoter sequences were identified by a bidirectional best blast hit strategy in genome survey sequences from Brassica oleracea. The analysis of 779 microarrays from 81 different experiments provided detailed expression information for Arabidopsis genes coexpressed in multiple tissues and under various conditions and developmental stages. We discovered candidate transcription factor binding sites in 64% of the Arabidopsis genes analyzed. Among them, we detected experimentally verified binding sites and showed strong enrichment of shared cis-elements within functionally related genes. This study demonstrates the value of partially shotgun sequenced genomes and their combinatorial use with functional genomics data to address complex questions in comparative genomics.
Arabidopsis↗
Host and direct antitumor effects and profound reduction in tumor metastasis with selective EP4 receptor antagonism.
Prostaglandin E(2) (PGE(2)), one of the major metabolites of cyclooxygenase-2, has been implicated in tumorigenesis and tumor progression in several human cancers, including colorectal and lung. Here, we show that one of the PGE(2) receptors, the EP4 receptor, plays an important role in metastasis in both of these tumor types. Using i.v. injected Lewis lung carcinoma (3LL), we found that tumor metastasis to lung was significantly reduced when mice were treated with a specific EP4 antagonist ONO-AE3-208 or when EP4 receptor expression was knocked down in the tumor cells using RNA interference technology. Host EP4 receptors also contributed to tumor metastasis and tumor growth with decreased metastasis and tumor growth observed in EP4 receptor knockout animals. In vitro tumor cell adhesion, motility, invasion, colony formation, and Akt phosphorylation were all significantly inhibited when 3LL cells were treated with the EP4 receptor-specific antagonist. When the cells were treated with an EP4-specific agonist (AE1-734), we observed a worsening of these same features in vitro. Treatment with ONO-AE3-208 also profoundly decreased liver metastases after intrasplenic injection of MC26 colon cancer cells. Our data show that selective antagonism of EP4 receptor signaling results in a profound reduction in lung and colon cancer metastasis. Selective antagonism of the EP4 receptor may thus represent a novel therapeutic approach for the treatment of cancer and especially its propensity to metastasize.
Animals↗
DNA damage induced by resveratrol and its synthetic analogues in the presence of Cu (II) ions: mechanism and structure-activity relationship.
The prooxidant effect of resveratrol (3,5,4'-trihydroxy-trans-stibene) and its synthetic analogues (ArOH), that is, 3,4,4'-trihydroxy-trans-stibene (3,4,4'-THS), 3,4,5-trihydroxy-trans-stibene (3,4,5-THS), 3,4-dihydroxy-trans-stibene (3,4-DHS), 4,4'-dihydroxy-trans-stibene (4,4'-DHS), 2,4-dihydroxy-trans-stilbene (2,4-DHS), 3,5-dihydroxy-trans-stilbene (3,5-DHS) and 3,5,4'-trimethoxy-trans-stibene (3,5,4'-TMS), on supercoiled pBR322 plasmid DNA strand breakage and calf thymus DNA damage in the presence of Cu (II) ions has been studied. It was found that the compounds bearing ortho-dihydroxyl groups (3,4-DHS, 3,4,4'-THS, and 3,4,5-THS) or bearing 4-hydroxyl groups (2,4-DHS, 4,4'-DHS, and resveratrol) exhibit remarkably higher activity in the DNA damage than the ones bearing no such functionalities. Kinetic analysis by UV-visible spectra demonstrates that the formation of ArOH-Cu (II) complexes, the stabilization of oxidative intermediate derived from ArOH and Cu (II)/Cu (I) redox cycles, might be responsible for the DNA damage. This study also reveals a good correlation between antioxidant and prooxidant activity, as well as cytotoxicity against human leukemia (HL-60 and Jurkat) cell lines. The mechanisms and implications of these observations are discussed.
Copper↗
Association between polymorphisms in serotonin 2C receptor gene and attention-deficit/hyperactivity disorder in Han Chinese subjects.
Attention deficit hyperactivity disorder (ADHD) is much more frequent in males than females, so several genes on the X chromosome (e.g., MAOA and MAOB) have been pursued as candidates for influencing risk for the disorder. HTR2C is also located on the X chromosome. In the current study, we examined the relationship between the C-759T and G-697C polymorphisms of HTR2C and ADHD in 488 Han Chinese families. Transmission Disequilibrium Test (TDT) analysis showed that the -759C allele, the -697G allele, and haplotype -759C/-697G were significantly over-transmitted to affected probands, while haplotypes -759C/-697C and -759T/-697C were under-transmitted. When families were divided into three subtypes according to the diagnosis of probands, the -697G allele and haplotype -759C/-697G were significantly over transmitted to ADHD-C probands, while haplotype -759T/-697C was under-transmitted to these individuals; however, no biased transmission of any allele or haplotype was observed for probands with ADHD-I, suggesting that different subtypes of ADHD have different genetic influences. Our findings highlight the need to explore the role of 5-HT2C receptor dysfunction in the pathogenesis of ADHD.
Attention Deficit Disorder with Hyperactivity↗
Effect of breviscapine on fractalkine expression in chronic hypoxic rats.
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Animals↗
Long-period grating refractive index sensor with a modified cladding structure for large operational range and high sensitivity.
What is believed to be a novel long-period grating (LPG) refractive index sensor with a modified cladding structure is proposed and studied. In the proposed structure, the cladding of the fiber has a two-layer structure, i.e., a cladding layer of low refractive index with a reduced radius and an overlay of high refractive index. The sensitivity of the structure-modified LPG sensor to the ambient refractive index change as a function of the cladding layer and overlay parameters is investigated by way of modeling. It is found that an increase of the ambient refractive index causes a field redistribution of the cladding mode into the overlay when the parameters of the overlay are properly selected. It is shown that by reducing the radius of the cladding layer, the operational range of the LPG refractive index sensor can be as large as 0.195 (from 1.244 to 1.440) with a minimum sensitivity of 660 nm/refractive index, which represents a 31% increase of operational range in comparison with the operational range obtained from the reported structure. The design guidelines for achieving this large operation range and high sensitivity are explained by investigating the dependence of the cladding modes on the radius of the cladding layer.
Journal Article↗
Clinical vignette. Echocardiographic detection of intracardiac non-metallic foreign body complicated by infective endocarditis.
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Child↗