Search PubMed⌕ Search

Biomedical subjects

Jie Yang

Publications and source records attributed to Jie Yang.

At least 163 records · Page 9Linked to original sources
PubMed2004

Characteristics of genetic epidemiology and genetic models for vitiligo.

BACKGROUND: Vitiligo occurs with a frequency of 0.1% to 2% in various populations and is classified into several subtypes by its clinical presentation. Although genetic factors are thought to be involved in the cause of vitiligo, the genetic models for different phenotypes of vitiligo are unknown. OBJECTIVE: Our purpose was to explore potential genetic models for different phenotypes of vitiligo and analyze genetic epidemiologic characteristics of vitiligo in a Chinese population. METHODS: Information from 2247 patients and members in their families was collected using a uniform questionnaire. Patients' clinical characteristics and their family history were analyzed using software. A complex segregation analysis was conducted to propose potential genetic models for vitiligo. RESULTS: Different subtypes of vitiligo had different ages of disease onset. In relatives of patients with vitiligo, the risk of developing vitiligo increased with increasing relatedness to the patients with vitiligo. A polygenic additive model was the best model for focal vitiligo, vitiligo vulgaris, acrofacial vitiligo, and segmental vitiligo with approximately 50% heritability in each. For universal vitiligo, the best model was an environmental model. CONCLUSION: This study indicated that different phenotypes of vitiligo had different pathogeneses and genetic backgrounds. Onset of vitiligo is possibly affected by both genetic backgrounds and common environmental factors.

Adolescent↗
PubMed2004

Mirror image condylar hyperplasia in two siblings.

A Hispanic family with an unusual clinical and radiological pattern of condylar hyperplasia is presented. Mirror images of condylar hyperplasia, malocclusion of teeth, and shift of midline of the mandible were seen in two brothers. The father had a similar abnormality of his left mandibular condyle. The condylar hyperplasia in this family indicates that mandibular condylar hyperplasias could be genetic in origin, possibly Y-linked or autosomal dominant.

Adult↗
PubMed2004

CT features of synovial chondromatosis in the temporomandibular joint.

OBJECTIVE: The purpose of this study was to determine the characteristic computed tomography (CT) findings of synovial chondromatosis of the temporomandibular joint (TMJ). STUDY DESIGN: Eight subjects with synovial chondromatosis were examined with axial and coronal CT scans. All lesions were histopathologically confirmed either through an arthroscopic punch biopsy or surgery. CT appearances of the lesions were reviewed and classified. RESULTS: Among the 8 subjects, 7 (87.5%) demonstrated soft tissue swelling, 7 (87.5%) showed loose calcified bodies, and 6 (75%) had bony changes of the articular surfaces. Patterns of the skull base changes as well as intracranial extension of the disease were identified. CONCLUSIONS: Based on the CT findings, synovial chondromatosis of the TMJ is characterized by soft tissue swelling, loose calcified bodies, and bony changes of the skull base. The latter may lead to destruction of the central skull base and intracranial extension.

Adult↗
PubMed2004

Molecular basis of Stat1 and PU.1 cooperation in cytokine-induced Fcgamma receptor I promoter activation.

The high-affinity receptor for IgG (FcgammaRI) is a myeloid cell-specific and IFN-gamma-induced gene, and thereby serves as a paradigm for cytokine-induced cell type-specific gene responses. The expression of FcgammaRI is regulated by PU.1 and Stat1 transcription factors. We established an experimental model to analyze the individual functions of Stat1 and PU.1 in cytokine-induced transcription of the natural FcgammaRI promoter in U3A cells lacking both factors. PU.1 was required for both the basal activity and for the IFN-gamma-induced FcgammaRI promoter activation, while Stat1 alone could not initiate transcription. In contrast, in the context of a heterologous promoter, PU.1 inhibited the Stat1-mediated transcription. Systematic analysis of Stat1 and PU.1 mutants and FcgammaRI promoter elements revealed that activation of the promoter required the DNA binding, and the transactivation functions of both Stat1 and PU.1. PU.1 and Stat1 bound the promoter elements independently, and no physical interaction between the proteins was observed. The requirement of PU.1 for FcgammaRI promoter activity was supported by demonstration of in vitro interaction between PU.1 and components of the basal transcription machinery TBP and RNA polymerase II. Deletion of the acidic transactivation domain of PU.1 greatly diminished both the FcgammaRI promoter activity as well as the interaction with RNA polymerase II. In contrast, Stat1 did not interact with TBP or RNA polymerase II. These results define functional cooperativity between PU.1 and Stat1 in FcgammaRI promoter activation where PU.1 serves as an amplifier and bridging factor with the basal transcription machinery.

Animals↗
PubMed2004

Automatic detection and recognition of signs from natural scenes.

In this paper, we present an approach to automatic detection and recognition of signs from natural scenes, and its application to a sign translation task. The proposed approach embeds multiresolution and multiscale edge detection, adaptive searching, color analysis, and affine rectification in a hierarchical framework for sign detection, with different emphases at each phase to handle the text in different sizes, orientations, color distributions and backgrounds. We use affine rectification to recover deformation of the text regions caused by an inappropriate camera view angle. The procedure can significantly improve text detection rate and optical character recognition (OCR) accuracy. Instead of using binary information for OCR, we extract features from an intensity image directly. We propose a local intensity normalization method to effectively handle lighting variations, followed by a Gabor transform to obtain local features, and finally a linear discriminant analysis (LDA) method for feature selection. We have applied the approach in developing a Chinese sign translation system, which can automatically detect and recognize Chinese signs as input from a camera, and translate the recognized text into English.

Algorithms↗
PubMed2004

Less inhibition of interferon-gamma to organism growth in host cells may contribute to the high susceptibility of C3H mice to Chlamydia trachomatis lung infection.

T-helper-1-like cytokine response and cell-mediated immunity have been shown to be critical in host resistance to Chlamydia trachomatis infection. Using a murine pneumonia model, we compared the susceptibility of C3H/HeN (C3H) and C57BL/6 mice to C. trachomatis mouse pneumonitis (MoPn) infection. C3H mice exhibited significantly higher mortality, greater organism growth and much more severe pathological changes in the lung compared with C57BL/6 mice. However, the pattern of adaptive immune responses including organism-specific delayed-type hypersensitivity, antibody responses and cytokine [interferon-gamma (IFN-gamma), interleukin-12 (IL-12), IL-4, IL-10 and tumour necrosis factor alpha] production by spleen and local draining lymph node cells in these two strains of mice appeared comparable during the process of infection. Interestingly, MoPn growth in the cultured ex vivo macrophages from C3H mice was found to be significantly less inhibited by the exogenous IFN-gamma present in the culture compared to C57BL/6 mice. The lower inhibition of MoPn growth in C3H mice was associated with significantly lower nitric oxide production by the infected macrophages following IFN-gamma stimulation. The data suggest that the cellular events downstream of cytokine production in chlamydia host cells may be important in determining the different susceptibility of hosts to chlamydial infection.

Animals↗
PubMed2004

AFM as a high-resolution imaging tool and a molecular bond force probe.

This focused review summarizes certain aspects of recent developments in the use of atomic force microscope in high-resolution imaging of membrane-bound biological macromolecules and in molecular force probing of the interaction between biological conjugates. We point out the pros and cons in these approaches and critically analyze details involved in experiments.

Adsorption↗
PubMed2004

[Experimental study of the effect of Astragalus membranaceus against herpes simplex virus type 1].

OBJECTIVE: To study the inhibitory effects of Astragalus membranaceus on herpes simplex virus type 1(HSV-1). METHODS: In the 2BS cells infected with HSV-1, the antiviral effect of Astragalus membranaceus decoction was investigated by observing the inhibition of HSV-1-induced cytopathic effect in response to treatment with the decoction. RESULTS: The half inhibition concentration (IC50) and minimal inhibition concentration (MIC) of Astragalus membranaceus were 0.98 and 1.95 g/ml respectively, with the therapeutic index (TI) of 128. CONCLUSION: Astragalus membranaceus has obvious HSV-1-inhibiting efficacy and low cytotoxicity.

Antiviral Agents↗
PubMed2004

Interaction of human fibrinogen receptor (GPIIb-IIIa) with decorsin.

AIM: To build up the structure of human fibrinogen receptor GPIIb-IIIa, subsequently combined with its antagonist decorsin, and to investigate the interaction between decorsin and its receptor GPIIb-IIIa at the molecular level. METHODS: A three-dimensional (3D) molecular model of human fibrinogen receptor GPIIb-IIIa was generated by InsightII, a distance geometry-based homologous modeling package. The structure of human fibrinogen receptor GPIIb-IIIa was built by the InsightII/Homology module using the corresponding of integrin alphaVbeta3 (PDB filecode 1JV2) as the template. Then the primary structures were optimized by energy minimization. Subsequently the structural model was docked with its antagonist decorsin (PDB filecode 1dec). RESULTS: A good substrate-receptor interaction model was achieved. The interaction sites with decorsin converge at domain 8 (betaA domain of beta3 subunit) of GPIIb-IIIa. The direct interatomic contacts were made between 16 GPIIb/IIIa residues and 10 decorsin amino-acid residues. These included van der Waals contacts, electrostatic interaction, hydrogen bond, and salt bridge. Residues in contact were concentrated in four dispersed regions of human GPIIb-IIIa: the RGD reaction motif (118-132 of GPIIIa), the span from 210 to 213 of GPIIIa, Thr182 residue and Asp251 residue of GPIIIa; and they were distributed over five segments of decorsin: Asp10 residue, Asn18 and Lys19 residues, Arg28 residue, RGD motif, and Asp35-Pro36-Tyr37 segment. CONCLUSION: This complex model plays an important role in development and research of some new drugs, especially a new guided fusion-type fibrinogen receptor antagonist.

Amino Acid Sequence↗
PubMed2004

[The porcine alpha1, 3 galactosyltransferase gene siRNA targeted heterozygous hepatocyte negative express GT].

OBJECTIVE: To study whether the porcine alpha1, 3 galactosyltransferase gene siRNA targeted heterozygous hepatocyte negatively expresses GT mRNA and resists to the cytotoxicity of nature antibody in human serum. METHODS: The porcine alpha1, 3 galactosyltransferase gene siRNA targeted vector (pPNTloxPGTsiRNA) were construct with pPNTloxPGT and pMXSV/U6 vector. Positive-negative selection was used to produce a heterozygous pPNTloxPGTsiRNA knockout (+/-) clone. The GT mRNA expressions were detected with northern blot. Complement-mediated NAb cytotoxicity after incubation of hepatocytes with NAbs and complement was determined using 3- (4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium(MTS, tetrazolium salt) colorimetric assay. RESULTS: The pPNTloxPGTsiRNA targeted porcine hepatocyte (+/-) negative express GT mRNA. Only 14% to 18% cytotoxicity can be detected at the highest serum concentration. The pPNTloxPGT targeted porcine hepatocyte (+/-) express GT mRNA just as the wild type porcine cells and the cytotoxicity are 77% to 83%. CONCLUSION: The porcine a1, 3 galactosyltransferase gene siRNA targeted heterozygous hepatocyte (+/-) negative express GT and resisted to nature antibody in human serum.

Animals↗
PubMed2004

[Study on cryopreservative methods for dendritic cells derived from K562 cell line].

To investigate the biological properties of cryopreserved dendritic cell (DC) derived from K562 cell line, thus to provide a simple, quick and efficient preservative method of DC for infusion of DC to patients with leukemia after complete remission, fresh DC induced from K562 cell line (K562-DC) was frozen in -196 degrees C liquid nitrogen and -80 degrees C mechanical freezer by method of steps (RPMI 1640 with 10% DMSO, 20% FCS as cryopreservatives), and thawed in different time, respectively. Survivals of cryopreserved and fresh K562-DC, expression of surface antigens, stimulating index (SI) and cytotoxic eliminating rate were detected. The results of fresh induced cells were compared with that of cryopreserved ones. The results showed that before and after frozen in liquid nitrogen, the morphological characteristics of K562-DC had no distinct change; and both their expression rates of surface molecular and capacity to stimulate allogeneic lymphocyte had no statistic significance (P > 0.05). In addition, there were no differences in terms of viability, stimulatory capacity and cytotoxicity of K562-DC from two ways for less than one month (P > 0.05), but there were differences when frozen for more than one month (P < 0.05). It is concluded that there is no significant difference when frozen less than one month between liquid nitrogen and -80 degrees C freezer; but when time is more than one month, K562-DC frozen in -196 degrees C liquid nitrogen is better than that in -80 degrees C freezer.

Antigens, Surface↗
PubMed2004

[Methodological study on digitalization of tongue image in traditional Chinese medical diagnosis].

This is a research aimed at proposing a computerized tongue analysis method based on computerized image processing for quantizing the tongue properties in traditional Chinese medical diagnosis. The chromatic algorithm and 2-D Gabor wavelet transformation are applied to segmenting tongue from original image. The statistical method is adopted in identifying the colors of each pixel, which are attributed to the tongue substance and coating respectively. Thickness of tongue coating is determined by energy of 2-D Gabor wavelet coefficients (GWTE). The distribution of GWTE and invariant moment algorithm are used to judge the tongue texture. The experiment result shows that all methods proposed in this paper are effective.

Algorithms↗
PubMed2003

Antiangiogenic and antitumor agents. Design, synthesis, and evaluation of novel 2-amino-4-(3-bromoanilino)-6-benzylsubstituted pyrrolo[2,3-d]pyrimidines as inhibitors of receptor tyrosine kinases.

Several different classes of growth factor receptors containing tyrosine kinases (RTK) are directly or indirectly involved in angiogenesis. Inhibition of these RTKs has provided a new paradigm in the treatment of tumors by restricting their growth and metastasis. We have designed, synthesized and evaluated eleven novel 2-amino-4-(3-bromoanilino)-6-substituted benzyl pyrrolo[2,3-d]pyrimidines as the first in a series of RTK inhibitors. These analogues were synthesized from appropriate alpha-bromomethylbenzyl ketones by cyclocondensation with 2,6-diamino-4-pyrimidone to afford the 2-amino-4-oxo-6-substituted benzyl pyrrolo[2,3-d]pyrimidines. Chlorination of the 4-position followed by displacement with 3-bromoaniline afforded the target compounds. In some instances, the 2-amino moiety of the pyrrolo[2,3-d]pyrimidines was protected prior to the chlorination and displacement followed by deprotection. The compounds were evaluated as inhibitors of vascular endothelial growth factor receptors VEGFR-2 (Flk-1, KDR) and VEGFR-1 (Flt-1); epidermal growth factor receptor (EGFR); and platelet-derived growth factor receptor-beta (PDGFR-beta). Selected compounds were also evaluated against the growth of A431 cells (which overexpress EGFR) in culture and as inhibitors of angiogenesis in the chicken embryo chorioallantonic membrane (CAM) assay. In each evaluation, a known standard compound was used as a comparison. Of the 11 analogues, five were more potent or equipotent as compared to standard compounds against the growth factor receptors. Two analogues showed superior inhibition of A431 cells in culture compared to the standard compounds. Three analogues were equipotent with the standard compound in the CAM assay and four of the analogues were dual inhibitors of RTKs. The structure-activity relationship for inhibition of different RTKs was quite distinct and different, and for VEGFR-2 and EGFR diametrically opposite. The inhibitory data against the RTKs in this study demonstrates that variation of the substituent(s) in the benzyl ring of these 2-amino-4-anilino 6-benzyl pyrrolo[2,3-d]pyrimidines does indeed control both the potency and specificity of inhibitory activity against RTKs.

Adenosine Triphosphate↗
PubMed2003

Creation of the first anomeric D/L-sugar kinase by means of directed evolution.

Chemoenzymatic routes toward complex glycoconjugates often depend on the availability of sugar-1-phosphates. Yet the chemical synthesis of these vital components is often tedious, whereas natural enzymes capable of anomeric phosphorylation are known to be specific for one or only a few monosaccharides. Herein we describe the application of directed evolution and a high-throughput multisugar colorimetric screen to enhance the catalytic capabilities of the Escherichia coli galactokinase GalK. From this approach, one particular GalK mutant carrying a single amino acid exchange (Y371H) displayed a surprisingly substantial degree of kinase activity toward sugars as diverse as d-galacturonic acid, d-talose, l-altrose, and l-glucose, all of which failed as wild-type GalK substrates. Furthermore, this mutant provides enhanced turnover of the small pool of sugars converted by the wild-type enzyme. Comparison of this mutation to the recently solved structure of Lactococcus lactis GalK begins to provide a blueprint for further engineering of this vital class of enzyme. In addition, the rapid access to such promiscuous sugar C-1 kinases will significantly enhance accessibility to natural and unnatural sugar-1-phosphates and thereby impact both in vitro and in vivo glycosylation methodologies, such as natural product glycorandomization.

Carbohydrate Sequence↗
PubMed2003

The herbal medicine Dipsacus asper wall extract reduces the cognitive deficits and overexpression of beta-amyloid protein induced by aluminum exposure.

Excess aluminum (Al) exposure impairs neurocognitive function in humans and animals. Epidemiologic studies have shown a potential link between chronic Al exposure and Alzheimer's disease. In the present study, we sought to evaluate the protective effects of the herbal medicine Dipsacus asper extract against the cognitive impairment and overexpression of hippocampal beta-amyloid protein (Abeta) induced by chronic Al exposure in rats. Vitamin E (VE) was used as a positive control. Following exposure to 0.3% aluminum chloride (AlCl(3)) solution for 90 days in their drinking water, animals displayed a striking decrease (>80%) in step-through latency in the passive avoidance task and a significant increase (123%) in the number of Abeta immunoreactive cells in the hippocampus compared to controls. Al-exposed animals were then randomly assigned to receive vehicle, Dipsacus asper extract (4 g/kg), or VE (40 mg/kg) treatment up to 5 months. Both Dipsacus asper extract and VE significantly ameliorated animal's performance impairment in the passive avoidance task and suppressed the overexpression of hippocampal Abeta immunoreactivity. The effects of Dipsacus asper extract, but not VE, increased with time of treatment. The present results suggest that Dipsacus asper extract may possess therapeutic effects against Alzheimer's disease.

Administration, Oral↗
PubMed2003

PIAS proteins promote SUMO-1 conjugation to STAT1.

Signal transducer and activator of transcription 1 (STAT1) is a critical mediator of interferon-gamma (IFN-gamma)-induced transcription that is regulated through posttranslational modifications and through transacting proteins such as protein inhibitor of activated STAT1 (PIAS1). PIAS proteins have been shown to function as E3-type small ubiquitin-like modifier (SUMO) ligases, and sumoylation has been identified as a modulatory mechanism for several transcription factors. Here we show that STAT1 is subject to SUMO-1 modification, and sumoylation occurs in vivo and in vitro at a single, evolutionary conserved amino acid residue Lys703. Members of the PIAS family of proteins were found to strongly stimulate sumoylation of STAT1. Furthermore, activation of STAT1 by IFN-gamma or pervanadate induced SUMO-1 conjugation. Mutation of Lys703 in STAT1 resulted in increased IFN-gamma-mediated transactivation, suggesting a negative regulatory function for sumoylation. These results indicate that STAT1 is covalently modified by SUMO-1 in cytokine signaling and that PIAS proteins promote SUMO-1 conjugation to STAT1.

DNA-Binding Proteins↗
PubMed2003

Studies on the substrate specificity of Escherichia coli galactokinase.

In vitro glycorandomization (IVG) technology is dependent upon the ability to rapidly synthesize sugar phosphates. Compared with chemical synthesis, enzymatic (kinase) routes to sugar phosphates would be attractive for this application. This work focuses upon the development of a high-throughput colorimetric galactokinase (GalK) assay and its application toward probing the substrate specificity and kinetic parameters of Escherichia coli GalK. The demonstrated dinitrosalicylic assay should also be generally applicable to a variety of sugar-processing enzymes. [reaction: see text]

Colorimetry↗