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1.
Pharmacology ; 108(2): 166-175, 2023.
Article in English | MEDLINE | ID: mdl-36724745

ABSTRACT

INTRODUCTION: DPP4 is thought to be involved in certain immune processes and plays an important role in allergic reactions in the lungs. The effect of the DPP4 inhibitor sitagliptin on the effector phase of allergic rhinitis (AR) in ovalbumin (OVA)-sensitized mice and on mast cell degranulation in vitro was assessed. METHODS: The AR mouse model was established by intraperitoneal injection combined with OVA intranasal method. OVA was injected intraperitoneally 3 times for the first 2 weeks, and the mice were subsequently given DPP4 inhibitors by oral gavage, accompanied by an OVA intranasal challenge. The impacts of DPP4 inhibitors on DPP4 levels in mouse model were determined. Nasal mucosa tissue was collected for H&E staining and toluidine blue staining. Immunoglobulin E (IgE) levels and histamine levels were analyzed, and IL-4, IL-5, and IL-12 as well as IFN-γ levels were assessed. Following the treatment of dinitrophenol (DNP)-IgE or DNP-IgE plus sitagliptin in RBL-2H3 cells, ß-hexosaminidase activity was analyzed and toluidine blue staining was performed. RESULTS: DPP4 level was reduced in AR patients, as well as in AR mouse models. Nasal allergic symptoms such as sneezing and nose-scratching showed high frequency in OVA-induced mice. Sitagliptin treatment during the intranasal challenge of OVA decreased DPP4 levels, suppressed allergic symptoms, eosinophil infiltration, IgE levels, mast cell infiltration, as well as the levels of inflammatory cytokines. We further found that sitagliptin inhibited mast cell activation and histamine levels in vitro. CONCLUSION: Sitagliptin suppresses the effector phase of AR, and this mechanism is partly attributed to the suppression of inflammatory response and mast cell degranulation.


Subject(s)
Dipeptidyl-Peptidase IV Inhibitors , Rhinitis, Allergic , Mice , Animals , Dipeptidyl-Peptidase IV Inhibitors/pharmacology , Histamine/pharmacology , Sitagliptin Phosphate/pharmacology , Mast Cells , Dipeptidyl Peptidase 4/adverse effects , Tolonium Chloride/adverse effects , Immunoglobulin E , Rhinitis, Allergic/chemically induced , Cytokines , Nasal Mucosa , Ovalbumin/adverse effects , Hypoglycemic Agents/pharmacology , Mice, Inbred BALB C , Disease Models, Animal
2.
Immun Inflamm Dis ; 11(1): e763, 2023 01.
Article in English | MEDLINE | ID: mdl-36705419

ABSTRACT

OBJECTIVE: Allergic rhinitis (AR) is primarily regulated by type I hypersensitivity, with Th2 and immunoglobulin E (IgE) playing essential roles. This study aimed to determine whether angiotensin converting enzyme (ACE)2 could participate in the regulation of AR. METHODS: Nasal mucosal tissues of AR patients were collected to determine ACE2 levels. Following AR mouse models were established, ACE2 levels in nasal mucosa were determined. Then the influences of diminazene aceturate (ACE2 agonist) on AR symptoms, pathology, specific antibodies, histamine, and interleukins (ILs) release in vivo were evaluated. Afterward, human nasal mucosa epithelial cells were exposed to IL-13, and the impacts of ACE2 overexpression on the secretion of pro-inflammatory factors in vitro were assessed. RESULTS: ACE2 levels significantly declined in nasal mucosa both in patients and mouse models (p < .001). Diminazene aceturate treatment elevated the ACE2 level in mice (p < .01), accompanied by reduced frequency of nasal spray and nasal friction, decreased eosinophils and goblet cells (p < .001) according to histopathological staining. Furthermore, lgE, lgG1, histamine, and IL levels in mice were also decreased (p < .05). In vitro experiments revealed that ACE2 overexpression suppressed the secretion of pro-inflammatory factors (p < .001). CONCLUSION: Together, ACE2 activation can alleviate the symptoms of AR in mice and inhibit the release of Th2 cytokines. Activating ACE2 is a promising therapeutic approach for AR.


Subject(s)
Angiotensin-Converting Enzyme 2 , Cytokines , Rhinitis, Allergic , Animals , Humans , Mice , Angiotensin-Converting Enzyme 2/metabolism , Cytokines/metabolism , Histamine , Rhinitis, Allergic/metabolism , Th2 Cells
3.
Biomed Eng Online ; 21(1): 53, 2022 Aug 02.
Article in English | MEDLINE | ID: mdl-35918704

ABSTRACT

BACKGROUND: CPT-11 (irinotecan) is one of the most efficient agents used for colorectal cancer chemotherapy. However, as for many other chemotherapeutic drugs, how to minimize the side effects of CPT-11 still needs to be thoroughly described. OBJECTIVES: This study aimed to develop the CPT-11-loaded DSPE-PEG 2000 targeting EGFR liposomal delivery system and characterize its targeting specificity and therapeutic effect on colorectal cancer (CRC) cells in vitro and in vivo. RESULTS: The synthesized liposome exhibited spherical shapes (84.6 ± 1.2 nm to 150.4 nm ± 0.8 nm of estimated average sizes), good stability, sustained release, and enough drug loading (55.19%). For in vitro experiments, SW620 cells treated with CPT-11-loaded DSPE-PEG2000 targeting EGFR liposome showed lower survival extended level of intracellular ROS production. In addition, it generated an enhanced apoptotic cell rate by upregulating the protein expression of both cleaved-caspase-3 and cleaved-caspase-9 compared with those of SW620 cells treated with free CPT-11. Importantly, the xenograft model showed that both the non-target and EGFR-targeted liposomes significantly inhibited tumor growth compared to free CPT-11. CONCLUSIONS: Compared with the non-target CPT-11-loaded DSPE-PEG2000 liposome, CPT-11-loaded DSPE-PEG2000 targeting EGFR liposome treatment showed much better antitumor activity in vitro in vivo. Thus, our findings provide new assets and expectations for CRC targeting therapy.


Subject(s)
Antineoplastic Agents , Colonic Neoplasms , Cell Line, Tumor , Colonic Neoplasms/drug therapy , Drug Delivery Systems , ErbB Receptors , Humans , Irinotecan/pharmacology , Liposomes
4.
Polymers (Basel) ; 14(9)2022 Apr 21.
Article in English | MEDLINE | ID: mdl-35566849

ABSTRACT

Oxidized sodium alginate (OSA) is selected as an appropriate material to be extensively applied in regenerative medicine, 3D-printed/composite scaffolds, and tissue engineering for its excellent physicochemical properties and biodegradability. However, few literatures have systematically investigated the structure and properties of the resultant OSA and the effect of the oxidation degree (OD) of alginate on its biodegradability and gelation ability. Herein, we used NaIO4 as the oxidant to oxidize adjacent hydroxyl groups at the C-2 and C-3 positions on alginate uronic acid monomer to obtain OSA with various ODs. The structure and physicochemical properties of OSA were evaluated by Fourier transform infrared spectroscopy (FT-IR), 1H nuclear magnetic resonance (1H NMR), X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD), and thermogravimetric analysis (TGA). At the same time, gel permeation chromatography (GPC) and a rheometer were used to determine the hydrogel-forming ability and biodegradation performance of OSA. The results showed that the two adjacent hydroxyl groups of alginate uronic acid units were successfully oxidized to form the aldehyde groups; as the amount of NaIO4 increased, the OD of OSA gradually increased, the molecular weight decreased, the gelation ability continued to weaken, and degradation performance obviously rose. It is shown that OSA with various ODs could be prepared by regulating the molar ratio of NaIO4 and sodium alginate (SA), which could greatly broaden the application of OSA-based hydrogel in tissue engineering, controlled drug release, 3D printing, and the biomedical field.

5.
Bioengineered ; 13(4): 8712-8723, 2022 04.
Article in English | MEDLINE | ID: mdl-35333690

ABSTRACT

Targeted therapy is an important therapeutic strategy currently, however, the development of targeted therapy for nasopharyngeal carcinoma (NPC) is relatively lagging. Cullin 4A (CUL4A) was reported to be overexpressed in NPC; nevertheless, the specific role of CUL4A remains unrevealed. NPC cells and tumor-bearing mice were cultivated to explore the role and mechanism of CUL4A in NPC. After evaluating CUL4A levels in NPC cells, functional experiments were carried out to investigate the effects of CUL4A knockdown and overexpression on cell proliferative, invasive and migratory aptitude as well as NF-κB signaling. Following the GeneMANIA database predicted that protein arginine methyltransferase 5 (PRMT5) was downstream of CUL4A, the mediated role of PRMT5 in the regulation of CUL4A on cells was then determined. Moreover, the tumor volumes and weights of tumor-bearing mice were recorded, and the levels of proliferation-, migration-, and NF-κB signaling-related proteins in the tumor were determined. Herein, CUL4A was enhanced in NPC cells, and its knockdown and overexpression separately suppressed and promoted cell proliferative, invasive, and migratory aptitude as well as NF-κB signal activation. Novelty, PRMT5 knockdown reversed the influences of CUL4A overexpression on these aspects. In addition, its knockdown likewise reversed the facilitating impact of CUL4A expression on tumor growth and declined the expression levels of proliferation-, migration-, and NF-κB signaling-related protein in the tumor. Together, this paper indicated that CUL4A promoted the proliferative, invasive, and migratory aptitude of NPC cells as well as tumor growth by promoting PRMT5 to activate NF-κB signaling.


Subject(s)
Cullin Proteins , Nasopharyngeal Neoplasms , Protein-Arginine N-Methyltransferases , Animals , Cell Line, Tumor , Cell Proliferation/genetics , Cullin Proteins/genetics , Cullin Proteins/metabolism , Mice , NF-kappa B/genetics , NF-kappa B/metabolism , Nasopharyngeal Carcinoma/genetics , Nasopharyngeal Neoplasms/metabolism , Phenotype , Protein-Arginine N-Methyltransferases/genetics , Protein-Arginine N-Methyltransferases/metabolism
6.
Ann Transl Med ; 9(12): 995, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34277795

ABSTRACT

BACKGROUND: Abnormal lipid metabolism has been reported in patients with idiopathic pulmonary arterial hypertension (IPAH); however, the prognostic value of plasma free fatty acids (FFAs) for these patients is unclear. The present study aimed to determine whether FFA can play a role in predicting the survival of patients with IPAH. METHODS: A total of 69 blood samples from patients with IPAH were subjected to liquid chromatography-mass spectrometry (LC-MS). According to the classification criteria for pulmonary hypertension in the European Society of Cardiology (ESC) guidelines, patients were divided into low-risk, intermediate-risk, and high-risk groups. The FFA expression levels of patients in the three groups were compared, and the indicators with significant differences were selected. Cox regression analysis was performed to examine the associations between survival and different factors. Receiver operator characteristic (ROC) curves were used to assess the predictive effect of plasma lipids in assessing patients' risk of morbidity, including area under the curve (AUC), sensitivity, specificity and the best cutoff value. Kaplan-Meier curves were used to predict survival. RESULTS: A total of 24 FFA molecules were detected in the patients with IPAH. Among them, FFA (20:4), FFA (20:5), FFA (22:5), FFA (22:6), FFA (24:0) and FFA (30:4) showed significant differences between the low-risk and the intermediate-risk or high-risk patients with IPAH. These six FFAs were significantly correlated with hemodynamic parameters. FFA (22:6), named docosahexaenoic acid (DHA), displayed significant negative correlations with World Health Organization functional classification (WHO FC), mean right atrial pressure (mRAP), and pulmonary vascular resistance (PVR), and significant positive correlations with 6-minute walking distance (6MWD) and cardiac index (CI). Cox regression analyses demonstrated that total bilirubin (TBIL) and DHA were independent risk factors for survival of IPAH. Receiver operating characteristic curve analysis revealed that DHA had a cut-off value of 77.55, which had a sensitivity of 96.7% and a specificity of 62.5% for predicting survival. Kaplan-Meier curve analysis showed that a lower level of DHA predicted a poor outcome in patients with IPAH. CONCLUSIONS: Our study suggested that FFA levels were correlated with disease severity. Lower levels of DHA predict poor survival in patients with IPAH.

8.
Biomed Chromatogr ; 33(11): e4644, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31276615

ABSTRACT

Telaprevir is a potent, selective, peptidomimetic inhibitor of the hepatitis C virus (HCV) NS3-4A serine protease. it is used for the treatment of HCV infection in combination with peginterferon alfa and ribavirin. In the present work, the E-Z isomerization process of telaprevir in solution was revealed by online HPLC-DAD (diode array detector)-MS, variable-temperature and variable-gradient experiments. The molecular geometry information of the two isomers was established by molecular mechanics calculations, and good correlation between the two isomers' UV-vis spectra and their molecular geometry information was also discovered. In addition, it was revealed by molecular docking that the two isomers have different affinities to HCV NS3•4A protease, and the Z isomer, the minor form of telaprevir in solution, is the more effective inhibitor of HCV NS3•4A protease. The investigation can provide more structure information about telaprevir in solution and in the binding process of HCV NS3•4A protease.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/metabolism , Chromatography, High Pressure Liquid/methods , Oligopeptides/chemistry , Oligopeptides/metabolism , Isomerism , Mass Spectrometry , Molecular Docking Simulation , Serine Proteases/chemistry , Serine Proteases/metabolism , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/metabolism
9.
Mol Cell Probes ; 37: 39-47, 2018 02.
Article in English | MEDLINE | ID: mdl-29179987

ABSTRACT

BACKGROUND: Colorectal cancer (CRC) is a common cancer with high morbidity and mortality. However, its molecular mechanism is not clear, nor the genes related to CRC stages. METHODS: Gene expression data in CRC and healthy colorectal tissues were obtained from gene expression omnibus. Limma package was used to identify the differentially expressed genes (DEGs) between control and CRC (stage I, II, III, and IV), obtaining 4 DEG sets. VennPlex was utilized to find all DEGs and intersection DEGs. Functional interactions between all DEGs and protein-protein interactions (PPIs) between intersection DEGs were analyzed using ReactomeFIViz and STRING, respectively, and networks were visualized. Known CRC-related genes were down-loaded from Comparative Toxicogenomics Database and mapped to PPI network. RESULTS: Totally, 851, 760, 729, and 878 DEGs were found between control and CRC stage I, II, III, and IV, respectively. Taken together, 1235 DEGs were found, as well as 128 up-regulated intersection DEGs, 365 down-regulated intersection DEGs, and 0 contra-regulated DEG. A functional interaction network of all DEGs and a PPI network of intersection DEGs were constructed, in which CDC20, PTTG1, and MAD2L1 interacted with BUB1B; UGT2B17 interacted with ADH1B; MCM7 interacted with MCM2. BUB1B, ADH1B, and MCM2 were known CRC-related genes. Gradually upregulated expressions of CDC20, PTTG1, MAD2L1, UGT2B17, and MCM7 in stage I, II, III, and IV CRC were confirmed by using quantitative PCR. Besides, up-regulated intersection DEGs enriched in pathways about Cell cycle, DNA replication, and p53 signaling. CONCLUSION: CDC20, PTTG1, MAD2L1, UGT2B17, and MCM7 might be CRC stage-related genes.


Subject(s)
Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Gene Expression Profiling , Adaptor Proteins, Signal Transducing/analysis , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Cdc20 Proteins/analysis , Cdc20 Proteins/genetics , Cdc20 Proteins/metabolism , Cell Cycle Proteins/analysis , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Databases, Genetic , Gene Expression Regulation, Neoplastic , Glucuronosyltransferase/analysis , Glucuronosyltransferase/genetics , Glucuronosyltransferase/metabolism , Humans , Minichromosome Maintenance Complex Component 7/analysis , Minichromosome Maintenance Complex Component 7/genetics , Minichromosome Maintenance Complex Component 7/metabolism , Minor Histocompatibility Antigens/analysis , Minor Histocompatibility Antigens/genetics , Minor Histocompatibility Antigens/metabolism , Neoplasm Staging , Nuclear Proteins/analysis , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Protein Interaction Maps , Securin/analysis , Securin/genetics , Securin/metabolism
10.
J Stroke Cerebrovasc Dis ; 26(7): 1622-1634, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28438516

ABSTRACT

OBJECTIVE: This study aims to investigate the molecular mechanism of injury development in the cortex and the striatum after cerebral ischemia/reperfusion (I/R). METHODS: Gene expression data (GSE23160) in the cortex and the striatum of an intraluminal middle cerebral artery occlusion-I/R mouse model (N = 12) and sham controls (N = 4) were downloaded from the Gene Expression Omnibus. Limma package was used to identify the differentially expressed genes (DEGs) between the I/R (2, 8, and 24 hours) and control groups. Correlation analysis was then performed to identify the highly correlated differentially expressed genes (HCDEGs). STRING and Cytoscape software were used to construct a protein-protein interaction (PPI) network of HCDEGs. Furthermore, Venny 2.0 was used to identify common overlapped DEGs whose transcription factors (TFs) were predicted using iRegulon in Cytoscape. RESULTS: For the cortex and the striatum, 2295 and 2282 DEGs were respectively identified between the I/R group and the controls, and were classified into 3 and 2 correlation modules. For each module, a PPI network was constructed, and Toll-like receptor 2 (Tlr2, degree = 25), interleukin 1ß (Il1b, degree = 21), and heme oxygenase-1 (Hmox1, degree = 17) had high connective degrees. Furthermore, 29 common overlapped DEGs were found across time and tissue, which might be targeted by 13 TFs. Especially, Tlr2, Il1b, and Hmox1 were targeted by myeloblastosis protein (Myb, target count = 16) and FBJ osteosarcoma protein (Fos, target count = 15). Moreover, plasminogen activator urokinase receptor (Plaur) was targeted by Fos, and it was an HCDEG in correlation modules of both cortex and striatum. Upregulation of Tlr2, Il1b, Hmox1, and Plaur in I/R injury was confirmed using quantitative polymerase chain reaction and immunohistochemical staining. CONCLUSION: Tlr2, Il1b, Hmox1, and Plaur regulated by Myb and Fos might participate in cortex and striatum injury after cerebral I/R.


Subject(s)
Basal Ganglia/metabolism , Cerebral Cortex/metabolism , Gene Expression Profiling/methods , Infarction, Middle Cerebral Artery/genetics , Oligonucleotide Array Sequence Analysis , Reperfusion Injury/genetics , Transcriptome , Animals , Basal Ganglia/pathology , Cerebral Cortex/pathology , Computational Biology , Databases, Genetic , Disease Models, Animal , Gene Expression Regulation , Gene Regulatory Networks , Heme Oxygenase-1/genetics , Heme Oxygenase-1/metabolism , Infarction, Middle Cerebral Artery/metabolism , Infarction, Middle Cerebral Artery/pathology , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice , Protein Interaction Maps , Proto-Oncogene Proteins c-fos/genetics , Proto-Oncogene Proteins c-fos/metabolism , Proto-Oncogene Proteins c-myb/genetics , Proto-Oncogene Proteins c-myb/metabolism , Receptors, Urokinase Plasminogen Activator/genetics , Receptors, Urokinase Plasminogen Activator/metabolism , Reperfusion Injury/metabolism , Reperfusion Injury/pathology , Signal Transduction , Time Factors , Toll-Like Receptor 2/genetics , Toll-Like Receptor 2/metabolism
12.
Cancer Discov ; 4(6): 662-673, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24675041

ABSTRACT

UNLABELLED: Non-small cell lung cancers (NSCLC) harboring anaplastic lymphoma kinase (ALK) gene rearrangements invariably develop resistance to the ALK tyrosine kinase inhibitor (TKI) crizotinib. Herein, we report the first preclinical evaluation of the next-generation ALK TKI, ceritinib (LDK378), in the setting of crizotinib resistance. An interrogation of in vitro and in vivo models of acquired resistance to crizotinib, including cell lines established from biopsies of patients with crizotinib-resistant NSCLC, revealed that ceritinib potently overcomes crizotinib-resistant mutations. In particular, ceritinib effectively inhibits ALK harboring L1196M, G1269A, I1171T, and S1206Y mutations, and a cocrystal structure of ceritinib bound to ALK provides structural bases for this increased potency. However, we observed that ceritinib did not overcome two crizotinib-resistant ALK mutations, G1202R and F1174C, and one of these mutations was identified in 5 of 11 biopsies from patients with acquired resistance to ceritinib. Altogether, our results demonstrate that ceritinib can overcome crizotinib resistance, consistent with clinical data showing marked efficacy of ceritinib in patients with crizotinib-resistant disease. SIGNIFICANCE: The second-generation ALK inhibitor ceritinib can overcome several crizotinib-resistant mutations and is potent against several in vitro and in vivo laboratory models of acquired resistance to crizotinib. These findings provide the molecular basis for the marked clinical activity of ceritinib in patients with ALK-positive NSCLC with crizotinib-resistant disease. Cancer Discov; 4(6); 662-73. ©2014 AACR. See related commentary by Ramalingam and Khuri, p. 634 This article is highlighted in the In This Issue feature, p. 621.


Subject(s)
Antineoplastic Agents/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Protein Kinase Inhibitors/therapeutic use , Pyrimidines/therapeutic use , Receptor Protein-Tyrosine Kinases/antagonists & inhibitors , Sulfones/therapeutic use , Anaplastic Lymphoma Kinase , Animals , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Crizotinib , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/genetics , Humans , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Mice , Mice, SCID , Mutation , Pyrazoles/therapeutic use , Pyridines/therapeutic use , Receptor Protein-Tyrosine Kinases/genetics , Receptor Protein-Tyrosine Kinases/metabolism , Tumor Burden
13.
BMC Infect Dis ; 13: 249, 2013 May 30.
Article in English | MEDLINE | ID: mdl-23718728

ABSTRACT

BACKGROUND: Hand hygiene compliance is generally assessed by observation of adherence to the "WHO five moments" using numbers of opportunities as the denominator. The quality of the activity is usually not monitored since there is no established methodology for the routine assessment of hand hygiene technique. The aim of this study was to objectively assess hand rub coverage of staff using a novel imaging technology and to look for patterns and trends in missed areas after the use of WHO's 6 Step technique. METHODS: A hand hygiene education and assessment program targeted 5200 clinical staff over 7 days at the National University Hospital, Singapore. Participants in small groups were guided by professional trainers through 5 educational stations, which included technique-training and UV light assessment supported by digital photography of hands. Objective criteria for satisfactory hand hygiene quality were defined a priori. The database of images created during the assessment program was analyzed subsequently. Patterns of poor hand hygiene quality were identified and linked to staff demographic. RESULTS: Despite the assessment taking place immediately after the training, only 72% of staff achieved satisfactory coverage. Failure to adequately clean the dorsal and palmar aspects of the hand occurred in 24% and 18% of the instances, respectively. Fingertips were missed by 3.5% of subjects. The analysis based on 4642 records showed that nurses performed best (77% pass), and women performed better than men (75% vs. 62%, p<0.001). Further risk indicators have been identified regarding age and occupation. CONCLUSION: Ongoing education and training has a vital role in improving hand hygiene compliance and technique of clinical staff. Identification of typical sites of failure can help to develop improved training.


Subject(s)
Hand Hygiene/standards , Health Personnel/standards , Adult , Female , Hand Hygiene/methods , Hand Hygiene/statistics & numerical data , Health Education , Health Personnel/statistics & numerical data , Humans , Male , Middle Aged , Program Evaluation , Singapore , World Health Organization
14.
Biochem J ; 430(3): 425-37, 2010 Sep 15.
Article in English | MEDLINE | ID: mdl-20632993

ABSTRACT

ALK (anaplastic lymphoma kinase) is an RTK (receptor tyrosine kinase) of the IRK (insulin receptor kinase) superfamily, which share an YXXXYY autophosphorylation motif within their A-loops (activation loops). A common activation and regulatory mechanism is believed to exist for members of this superfamily typified by IRK and IGF1RK (insulin-like growth factor receptor kinase-1). Chromosomal translocations involving ALK were first identified in anaplastic large-cell lymphoma, a subtype of non-Hodgkin's lymphoma, where aberrant fusion of the ALK kinase domain with the NPM (nucleophosmin) dimerization domain results in autophosphosphorylation and ligand-independent activation. Activating mutations within the full-length ALK kinase domain, most commonly R1275Q and F1174L, which play a major role in neuroblastoma, were recently identified. To provide a structural framework for understanding these mutations and to guide structure-assisted drug discovery efforts, the X-ray crystal structure of the unphosphorylated ALK catalytic domain was determined in the apo, ADP- and staurosporine-bound forms. The structures reveal a partially inactive protein kinase conformation distinct from, and lacking, many of the negative regulatory features observed in inactive IGF1RK/IRK structures in their unphosphorylated forms. The A-loop adopts an inhibitory pose where a short proximal A-loop helix (alphaAL) packs against the alphaC helix and a novel N-terminal beta-turn motif, whereas the distal portion obstructs part of the predicted peptide-binding region. The structure helps explain the reported unique peptide substrate specificity and the importance of phosphorylation of the first A-loop Tyr1278 for kinase activity and NPM-ALK transforming potential. A single amino acid difference in the ALK substrate peptide binding P-1 site (where the P-site is the phosphoacceptor site) was identified that, in conjunction with A-loop sequence variation including the RAS (Arg-Ala-Ser)-motif, rationalizes the difference in the A-loop tyrosine autophosphorylation preference between ALK and IGF1RK/IRK. Enzymatic analysis of recombinant R1275Q and F1174L ALK mutant catalytic domains confirms the enhanced activity and transforming potential of these mutants. The transforming ability of the full-length ALK mutants in soft agar colony growth assays corroborates these findings. The availability of a three-dimensional structure for ALK will facilitate future structure-function and rational drug design efforts targeting this receptor tyrosine kinase.


Subject(s)
Catalytic Domain , Mutant Proteins/chemistry , Protein Conformation , Protein-Tyrosine Kinases/chemistry , Adenosine Diphosphate/chemistry , Adenosine Diphosphate/metabolism , Amino Acid Motifs/genetics , Amino Acid Sequence , Anaplastic Lymphoma Kinase , Animals , Cell Line , Crystallization , Crystallography, X-Ray , Humans , Kinetics , Models, Molecular , Molecular Sequence Data , Mutagenesis , Mutant Proteins/metabolism , Neuroblastoma/enzymology , Neuroblastoma/genetics , Phosphorylation , Protein Binding , Protein-Tyrosine Kinases/genetics , Protein-Tyrosine Kinases/metabolism , Receptor Protein-Tyrosine Kinases , Sequence Homology, Amino Acid , Spodoptera , Staurosporine/chemistry , Staurosporine/metabolism , Substrate Specificity
15.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 28(10): 931-3, 2008 Oct.
Article in Chinese | MEDLINE | ID: mdl-19123335

ABSTRACT

OBJECTIVE: To explore the clinical effects of colonic dripping with Taihuang liquid (THL) in treating neonatal hyperbilirubinemia (HBE). METHODS: One hundred and thirty-eight neonates with HBE were randomly assigned to two groups. Conventional treatment and nursing were given to both groups, and THL was given additionally to the observation group by colonic dripping. RESULTS: Significant differences between the observation group and the control group were shown in frequency of defecation (4.6 +/- 1.3 times/d vs 2.0 +/- 1.1 times/d), daily serum bilirubin reduction (31.5 +/- 10.1 micromol/L vs 23.3 +/- 8.3 micromol/L), and days for normalizing serum bilirubin level (5.6 +/- 3.5 d vs 7.8 +/- 4.1 d, all P < 0.01). CONCLUSION: Colonic dripping of THL could promote the excretion of bilirubin, so as to decrease the level of serum bilirubin in neonates with HBE.


Subject(s)
Drugs, Chinese Herbal/administration & dosage , Hyperbilirubinemia, Neonatal/drug therapy , Bilirubin/blood , Female , Humans , Hyperbilirubinemia, Neonatal/blood , Infant , Infant, Newborn , Male
16.
Bioorg Med Chem Lett ; 17(15): 4378-81, 2007 Aug 01.
Article in English | MEDLINE | ID: mdl-17574417

ABSTRACT

Novel anthranilamides were surprisingly found to exert additional activity on B-RAF. Corresponding thiophene, pyrazole, and thiazole core analogs were prepared as VEGFR-2 inhibitors with c-KIT, and B-RAF activity. Compounds in the phenyl, thiophene, and thiazole series are in vivo active.


Subject(s)
Antineoplastic Agents/pharmacology , Neoplasms/drug therapy , Protein Kinase Inhibitors/pharmacology , Vascular Endothelial Growth Factor Receptor-2/antagonists & inhibitors , Animals , Antineoplastic Agents/therapeutic use , Cell Line, Tumor , Humans , Mice , Protein Kinase Inhibitors/therapeutic use , Structure-Activity Relationship
17.
Ann Acad Med Singap ; 35(6): 408-10, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16865191

ABSTRACT

INTRODUCTION: In this paper, we report a novel VMD2 gene mutation in a Chinese family with Best vitelliform macular dystrophy. MATERIALS AND METHODS: Ophthalmologic examination and optical coherence tomography (OCT) were performed in 2 members of this family. Mutational screening was performed by single-strand conformation polymorphism (SSCP) and direct sequencing of PCR-amplified DNA fragments, corresponding to the 11 exons of the gene. RESULTS: Sequence analysis identified a previously unreported C to G change, predicting a Phe-113-Leu substitution. Both the proband and his sister harboured this novel mutation. Each had bilateral vitelliform lesions. CONCLUSIONS: A novel mutation in the VMD2 gene (C427G) was found in Chinese patients with Best vitelliform macular dystrophy.


Subject(s)
Eye Proteins/genetics , Macular Degeneration/genetics , Mutation , Adult , Bestrophins , China , Chloride Channels , Female , Humans , Male , Pedigree
18.
Zhonghua Yan Ke Za Zhi ; 41(4): 355-63, 2005 Apr.
Article in Chinese | MEDLINE | ID: mdl-15924700

ABSTRACT

OBJECTIVE: To investigate the waveform characters of single channel mVEP and its variability in normal Chinese people. METHODS: VERIS Science 4.3 system was used to record and analyze single channel mVEP. The stimulation was performed with a 60 pattern segment dartboard configuration. The Michelson contrast was 99% and the repetition rate 75 Hz. Recording electrodes were placed 3 cm above and 3 cm below the inion. The m-14 sequence required 4 minutes of recording time per eye, which was divided into 8 short segments. The signal was amplified 100 000 times and band-pass filtered between 3 and 100 Hz. The first slices of second kernel at 60 locations were analyzed. The main wave peak-to-trough amplitude and latency from 30 to 130 ms signal window were measured and calculated with the costumed Matlab program. The study included 64 normal subjects (39 women and 25 men). The age range was 13 - 66 years. 7 subjects were tested 2 - 7 times on different occasions for reproducibility. The statistic analysis was performed with Excel and SPSS. RESULTS: In mVEP trace array, the polarity of upper hemifield traces was usually opposite to lower hemifield traces. However, at near vertical meridian areas and near below horizontal meridian areas, the trace polarity had some variability. The main wave mean amplitudes of 60 location responses in left eye were from 0.177 microV to 0.401 microV. The amplitude CVs for 60 locations were from 36.6% to 60.7%. The mean latencies of 60 location responses were from 100 to 116 ms, and latency CVs were from 8.8% to 18.1%. The smaller signals located in zones of upper periphery, along vertical meridian, below horizontal meridian and the larger signals located in near horizontal meridian areas and near non-axial meridian areas which distribution is like a bow tie. There was smaller amplitude variability in the some upper hemifiled locations with smaller amplitude, and there was larger amplitude variability in the some lower hemifiled locations with larger amplitude. The mean amplitudes of all 60 locations in male subjects were lower than that in female subjects, in which 30 locations were low significantly (P < 0.05). The gender influence on latency was less, in which only at 10 locations the difference was significant (P < 0.05). At 20 locations of all, which were mainly distributed at near vertical meridian of lower hemifiled, there was a significant positive correlation of age with amplitude. The age influence on latency was also less. CONCLUSIONS: The larger variability of main wave peak-to-trough amplitude in single channel mVEP existed in different subjects and different locations of same subject. In analysis of mVEP amplitude, the influence of VEP curve location, gender and age should be considered. The main wave latencies of intersubject and intrasubject have smaller variability, and less effect by gender and age, so latency may be a useful diagnostic parameter.


Subject(s)
Evoked Potentials, Visual , Visual Fields , Adolescent , Adult , Age Factors , Aged , Asian People , Female , Humans , Male , Middle Aged , Sex Factors
19.
Zhonghua Yan Ke Za Zhi ; 41(3): 221-5, 2005 Mar.
Article in Chinese | MEDLINE | ID: mdl-15840362

ABSTRACT

OBJECTIVE: To investigate the diagnosis value of the frequency doubling perimetry (FDP) screening program in the aged 40 or more natural population-based glaucoma screening. METHODS: In 3 natural villages of Daxing District and 4 northern metropolitan communities of Beijing, 4439 subjects aged 40 or over were screened for glaucoma from May to October in 2001. The screening protocol C-20-1 of the frequency doubling perimetry (FDP) was used in all subjects. For suspect glaucoma subjects, TOP threshold visual field testing with an Octopus perimeter, gonioscopy and stereo fundusgraphy were performed on different days. Detected Glaucoma patients were classified as mild (MD 5 dB or less), moderate (MD > 5 dB and < 10 dB) and advanced (MD 10 dB or more) degrees according to their Octopus test results. FDP parameters including test time, numbers of abnormal location, comtotalon score and score by quadrant were analyzed. Data from one eye of normal subjects and milder eye of optic nerve damage in glaucoma subjects were analyzed. RESULTS: After excluding subjects whose fixation error or false positive error was > 0.33, data from 4330 subjects (97.54%) were analyzed. If abnormality of one location or more was used as a FDP cutoff, and subjects were divided into normal and glaucoma two groups (excluded other eye diseases in non-glaucoma subjects); the FDP had a sensitivity of 50.70% (72/142), a specificity of 90.58% (2260/2340), an area under the ROC curve (AUC) of 0.74, a positive predictive value (PV) of 47.71%, a negative predictive value of 96.95%, a positive likelihood ratio (LR) of 14.83 and a negative LR of 0.51. If excluded the eyes without glaucomatous optic nerve changes and visual field damage, the FDP had a sensitivity of 76.39%, an AUC of 0.87, a positive PV of 40.74%, a negative PV of 99.25%, a positive LR of 22.34 and a negative LR of 0.24. The sensitivity of detecting mild, moderate and advanced glaucoma was 54.17%, 76.00% and 100.00%, respectively. There was strong negative correlation between FDP quadrant score and quadrant mean sensitivity (MS) of Octopus perimetry in glaucoma patients (Spearman correlation, Rs = -0.732, -0.628, -0.639, -0.679, all P = 0.000). CONCLUSIONS: The FDP screening protocol C-20-1 is a very rapid functional test for screening glaucoma in large natural populations aged 40 or more and is proven to be feasible. It has high specificity and good sensitivity for moderate and advanced glaucoma.


Subject(s)
Glaucoma/diagnosis , Visual Field Tests/methods , Adult , Aged , Aged, 80 and over , Glaucoma/epidemiology , Humans , Mass Screening , Middle Aged , Sensitivity and Specificity , Visual Fields
20.
Chin Med J (Engl) ; 117(9): 1418-21, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15377440

ABSTRACT

BACKGROUND: Corneal dystrophy is a group of inherited blinding diseases of the cornea. This study was to identify the mutations of the keratoepithelin (KE) gene for proper diagnosis of corneal dystrophy. METHODS: Three families with corneal dystrophy were analysed. Thirteen individuals at risk for corneal dystrophy in family A, the proband and her son in family B, and the proband in family C were examined after their blood samples were obtained. Mutation screening of human transforming growth factor beta-induced gene (BIGH3 gene) was performed. RESULTS: Five individuals in family A were found by clinical evaluation to be affected with granular corneal dystrophy and carried the BIGH3 mutation W555R. However, both probands in families B and C, also diagnosed with granular corneal dystrophy, harboured the BIGH3 mutation R124H. CONCLUSION: Molecular genetic analysis can improve accurate diagnosis of corneal dystrophy.


Subject(s)
Corneal Dystrophies, Hereditary/genetics , Extracellular Matrix Proteins/genetics , Mutation , Transforming Growth Factor beta/genetics , Adolescent , Adult , Child , Child, Preschool , Corneal Dystrophies, Hereditary/pathology , Female , Humans , Male , Middle Aged
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