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Ling Wang

Publications and source records attributed to Ling Wang.

At least 109 records · Page 6Linked to original sources
PubMed2004

Enhanced antitumor efficacy on hepatoma-bearing rats with adriamycin-loaded nanoparticles administered into hepatic artery.

AIM: To investigate the antitumor activity of adriamycin (ADR) encapsulated in nanoparticles (NADR) and injected into the hepatic artery of hepatoma-bearing rats. METHODS: NADR was prepared by the interfacial polymerization method. Walker-256 carcinosarcomas were surgically implanted into the left liver lobes of 60 male Wistar rats, which were divided into 4 groups at random (15 rats per group). On the 7th day after implantation, normal saline (NS), free ADR (FADR), NADR, or ADR mixed with unloaded nanoparticles (ADR+NP) was respectively injected via the hepatic artery (i.a.) of rats in different groups. The dose of ADR in each formulation was 2.0 mg/kg body weight and the concentration was 1.0 mg/mL. Survival time, tumor enlargement ratio, and tumor necrosis degree were compared between each group. RESULTS: Compared with the rats that received NS i.a., the rats that received FADR or ADR+NP acquired apparent inhibition on tumor growth, as well as prolonged their life span. Further significant anticancer efficacy was observed in rats that received i.a. administration of NADR. Statistics indicated that NADR brought on a more significant tumor inhibition and more extensive tumor necrosis, as compared to FADR or ADR+NP. The mean tumor enlargement ratio on the 7th day after NADR i.a. was 1.106. The mean tumor-bearing survival time was 39.50 days. Prolonged life span ratio was 109.22% as compared with rats that accepted NS. CONCLUSION: Therapeutic effect of ADR on liver malignancy can be significantly enhanced by its nanopaticle formulation and administration via hepatic artery.

Animals↗
PubMed2004

Drug concentrations in axillary lymph nodes after lymphatic chemotherapy on patients with breast cancer.

BACKGROUND: Lymph node status is one of the decisive prognostic factors in breast cancer. Chemotherapy targeting regional lymphatic tissues has emerged as a promising therapy for the treatment of malignancies with a high tendency to disseminate lymphatically. The present study determined the drug concentrations in axillary lymph nodes after lymphatic chemotherapy (LC) in patients with breast cancer and compared the results with those receiving intravenous chemotherapy (VC) to investigate whether LC could improve the accumulation of anticancer drug in regional lymph nodes. METHODS: Sixty patients with breast carcinoma confirmed by preoperative puncture-biopsy were divided into two groups at random. The LC group (n = 30) received a subcutaneous injection of 4 ml of carboplatin-activated carbon suspension, containing 20 mg of carboplatin, adjacent to the primary tumour. The VC group (n = 30) received an intravenous administration of an equal dose of aqueous carboplatin. At 1, 12, 24, 36 and 48 hours after administration, modified radical mammectomies were performed on 12 patients at each time point, with 6 from each group. Axillary lymph nodes were removed for pathological examination. The platinum concentrations in nodes were determined by Zeeman atomic absorption spectrometry. RESULTS: A total of 275 axillary lymph nodes were resected, with 154 in the LC group and 121 in the VC group. Of the 275 lymph nodes, 136 (49.5%) from 23 patients (38.3%) had histopathologically detected metastases. At 1, 12, 24, 36 and 48 hours after injection, the carboplatin concentrations in the LC group were 11.82 +/- 3.50, 23.58 +/- 7.34, 18.22 +/- 4.93, 16.70 +/- 5.15 and 14.62 +/- 4.29 microg/g (means +/- SD), respectively, whereas those in the VC group were 0.06 +/- 0.02, 0.11 +/- 0.05, 0.10 +/- 0.02, 0.05 +/- 0.02 and 0 microg/g, respectively. Significant differences were found in each corresponding comparison (P < 0.001). Lymph node metastasis was uncorrelated with drug concentration (P > 0.05). CONCLUSION: LC can effectively and continuously improve the drug concentrations in axillary lymph nodes in patients with breast cancer, in comparison with VC.

Adult↗
PubMed2004

N-Aryl-gamma-lactams as integrin alphavbeta3 antagonists.

Novel alphavbeta3 antagonists based on the N-aryl-gamma-lactam scaffold were prepared. SAR studies led to the identification of potent antagonists for alphavbeta3 receptor with excellent selectivity against the structurally related alpha(IIb)beta3 receptor. Additional interactions of N-aryl-gamma-lactam derivatives with alphavbeta3 were found when compared to c(-RGDf[NMe]V-) peptide antagonist. The effects of the conformation and configuration of the gamma-lactam core on the binding were also assessed.

Animals↗
PubMed2004

The Kaposi's sarcoma-associated herpesvirus (KSHV/HHV-8) K1 protein induces expression of angiogenic and invasion factors.

Kaposi's sarcoma-associated herpesvirus (KSHV/HHV-8) has been linked to Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease. In addition to endothelial cells and B lymphocytes, KSHV also has been shown to infect epithelial cells and keratinocytes. The transmembrane glycoprotein K1, encoded by the first open reading frame of KSHV, is a signaling protein capable of eliciting B-cell activation. We show that KSHV K1 can induce expression and secretion of vascular endothelial growth factor (VEGF) in epithelial and endothelial cells. Up-regulation of VEGF was mediated at the transcriptional level because expression of K1 resulted in VEGF promoter activation. We also show that K1 induces expression of matrix metalloproteinase-9 (MMP-9) in endothelial cells. Additional analyses with K1 mutant proteins revealed that the SH2 binding motifs present in the K1 cytoplasmic tail are necessary for VEGF secretion and MMP-9 induction. These results indicate that K1 signaling may contribute to KSHV-associated pathogenesis through a paracrine mechanism by promoting the secretion of VEGF and MMP-9 into the surrounding matrix.

Cells, Cultured↗
PubMed2004

Regulation of the p300 HAT domain via a novel activation loop.

The transcriptional coactivator p300 is a histone acetyltransferase (HAT) whose function is critical for regulating gene expression in mammalian cells. However, the molecular events that regulate p300 HAT activity are poorly understood. We evaluated autoacetylation of the p300 HAT protein domain to determine its function. Using expressed protein ligation, the p300 HAT protein domain was generated in hypoacetylated form and found to have reduced catalytic activity. This basal catalytic rate was stimulated by autoacetylation of several key lysine sites within an apparent activation loop motif. This post-translational modification and catalytic regulation of p300 HAT activity is conceptually analogous to the activation of most protein kinases by autophosphorylation. We therefore propose that this autoregulatory loop could influence the impact of p300 on a wide variety of signaling and transcriptional events.

Acetyl Coenzyme A↗
PubMed2004

ORFDB: an information resource linking scientific content to a high-quality Open Reading Frame (ORF) collection.

The ORFDB (http://orf.invitrogen.com/) represents an ongoing effort at Invitrogen Corporation to integrate relevant scientific data with an evolving collection of human and mouse Open Reading Frame (ORF) clones (Ultimate ORF Clones). The ORFDB serves as a central data warehouse enabling researchers to search the ORF collection through its web portal ORFBrowser, allowing researchers to find the Ultimate ORF clones by blast, keyword, GenBank accession, gene symbol, clone ID, Unigene ID, LocusLink ID or through functional relationships by browsing the collection via the Gene Ontology (GO) Browser. As of October 2003, the ORFDB contains 6200 human and 2870 mouse Ultimate ORF clones. All Ultimate ORF clones have been fully sequenced with high quality, and are matched to public reference protein sequences. In addition, the cloned ORFs have been extensively annotated across six categories: Gene, ORF, Clone Format, Protein, SNP and Genomic links, with the information assembled in a format termed the ORFCard. The ORFCard represents an information repository that documents the sequence quality, alignment with respect to public protein sequences, and the latest publicly available information associated with each human and mouse gene represented in the collection.

Animals↗
PubMed2004

Volume-regulated anion conductance in cultured rat cerebral astrocytes requires calmodulin activity.

We examined the calmodulin dependence of anion channel activation during hypo-osmotic swelling in rat cerebral astrocytes. Control cells bathed in iso-osmotic (290 mOsm) phosphate-buffered saline (PBS) and recorded using a patch electrode containing 140 mM KCl increased membrane conductance threefold over basal levels after 12 min in hypo-osmotic (200 mOsm) PBS. Cells injected with monoclonal anticalmodulin antibody demonstrated no increase in membrane conductance during a subsequent exposure to hypo-osmotic PBS. In contrast, cells iontophoretically injected with monoclonal antiglial fibrillary acidic protein antibody or with anticalmodulin antibody absorbed with an excess of free calmodulin demonstrated an increase in conductance during hypo-osmotic exposure similar to that of control cells. Conductance in iso-osmotic conditions was unchanged by antibody injection. Similar results were obtained when using patch electrode and bath solutions containing chloride as the only cell permeant ion, indicating a calmodulin-dependent anion current is activated with this degree of hypo-osmotic treatment. Western blots confirmed the specificity of the anticalmodulin and antiglial fibrillary acidic protein antibodies used in this study for proteins of 17 and 51 kD, respectively. In addition, in vitro studies demonstrated inhibition of the calmodulin-dependent activation of phosphodiesterase by the anticalmodulin antibody. Thus, binding of this antibody to calmodulin causes functional inhibition of calmodulin activity. No change in the intensity or cellular distribution of calmodulin immunostaining was observed during 30 min of hypo-osmotic exposure. However, increased immunostaining for activated calmodulin kinase IIalpha was observed after 10 min of hypo-osmotic exposure, suggesting initiation of calmodulin-dependent processes by cell swelling. The data indicate calmodulin activity is critical for activation of volume-regulated anion channels in rat cerebral astrocytes.

Animals↗
PubMed2004

Background light adaptation of the retinal neuronal adaptive system. II. Dynamic effects.

The dynamic effects of continuous exposure to light on the neuronal adaptive system of the retina, as indicated by the oscillatory response (OPs) of the electroretinogram (ERG) were studied in the albino rat. Digitally filtered OPs and the a- and b-waves of the corneal ERG were simultaneously recorded in dark adaptation, during continuous light adaptation to four levels of background light (BGL) changing in steps of two log units from 1.43 x 10(-6) cd/m2, referred to as 'low and high scotopic, low and high mesopic' levels. Exposed to 'high scotopic' BGL the total oscillatory response (SOP) significantly enhanced within the first minute, whereas the amplitudes of the a- and b-waves were unaffected. In 'low mesopic' BGL the SOP increased within the first minute, whereas the a- and b-waves significantly decreased. 'High mesopic' BGL instantaneously and profoundly reduced both the SOP and the slow potentials. The individual OPs changed in amplitudes mainly within the first minute of BGL. In general, the earlier OPs (O1 and O2) reacted more to the two 'scotopic' BGL levels, whereas the later OPs (O3 and 04) were more affected by the relatively brighter two 'mesopic' conditions. In conclusion, the rapid increase of the OPs within the first minute of 'high scotopic' and 'low mesopic' BGL exposure may represent a rudimentary light adaptational effect in the rod-dominated rat retina. These findings also suggest that the neuronal adaptive mechanism of the retina seems to be a robust system, probably attaining preservation of visual abilities in the rat on exposure to light.

Adaptation, Ocular↗
PubMed2004

Preparation, characterization, and in vitro evaluation of physostigmine-loaded poly(ortho ester) and poly(ortho ester)/poly(D,L-lactide-co-glycolide) blend microspheres fabricated by spray drying.

The physostigmine-loaded poly(ortho ester) (POE), poly(dl-lactide-co-glycolide) (PLGA) and POE/PLGA blend microspheres were fabricated by a spray drying technique. The in vitro degradation of, and physostigmine release from, the microspheres were investigated. SEM analysis showed that the POE and POE/PLGA blend particles were spherical. They were better dispersed when compared to the pure PLGA microspheres. Two glass transition temperature ( Tg ) values of the POE/PLGA blend microspheres were observed due to the phase separation of POE and PLGA in the blend system. XPS analysis proved that POE dominated the surfaces of POE/PLGA blend microspheres, indicating that the blend microspheres were coated with POE. The encapsulation efficiencies of all the microspheres were more than 95%. The incorporation of physostigmine reduced the Tg value of microspheres. The Tg value of the degrading microspheres increased with the release of physostigmine. For instance, POE blank microspheres and physostigmine-loaded POE microspheres had a Tg value of 67 degrees C and 48 degrees C, respectively. After 19 days in vitro incubation, Tg of the degrading POE microspheres increased to 55 degrees C. Weight loss studies showed that the degradation of the blend microspheres was accelerated with the presence of PLGA because its degradation products catalyzed the degradation of both POE and PLGA. The release rate of physostigmine increased with increase of PLGA content in the blend microspheres. The initial burst release of physostigmine was effectively suppressed by introducing POE to the blend microspheres. However, there was an optimized weight ratio of POE to PLGA (85:15 in weight), below which a high initial burst was induced. The POE/PLGA blend microspheres may make a good drug delivery system.

Body Fluids↗
PubMed2004

Lysophospholipids and chemokines activate distinct signal transduction pathways in T helper 1 and T helper 2 cells.

We demonstrate the expression of S1P(1,3,4,5) the receptors for sphingosine 1-phosphate (S1P), and LPA(1,2,3) the receptors for lysophosphatidic acid (LPA) in T helper 1 (Th1) and T helper 2 (Th2) cells. S1P and LPA induce the chemotaxis of Th1 and Th2 cells, an activity that is resistant to pertussis toxin (PTX) pretreatment in Th1, but is sensitive in Th2 cells. Also, I-TAC-induced Th1 and eotaxin-induced Th2 cell chemotaxis are blocked by PTX pretreatment. LPA but not S1P induces calcium flux response in Th1 and Th2 cells, which is due to the influx of extracellular calcium and is mediated by receptor activation, since EGTA and suramin (SUR) completely abrogate LPA-induced the release of calcium. No cross-desensitization is observed between thapsigargin (TG) and LPA in both cell types. PTX and SUR but not EGTA inhibit I-TAC- or eotaxin-induced [Ca(2+)](i) release in Th1 and Th2 cells. Our results indicate that lysophospholipids and chemokines stimulate different signal transduction pathways.

Calcium↗
PubMed2004

Body distribution of nanoparticle-containing adriamycin injected into the hepatic artery of hepatoma-bearing rats.

The aim of the study was to investigate the body distribution of nanoparticle-containing adriamycin (NADR) injected into the hepatic artery of hepatoma-bearing rats. Thirty Walker-256 hepatoma-bearing rats were divided into two groups at random, with 15 rats in each. NADR and free adriamycin (FADR) were injected into the hepatic artery of animals on the seventh day after tumor implantation. At 1, 5, and 15 hr, after administration, five animals in each group were sacrificed and the ADR concentrations in the plasma, liver, heart, spleen, lungs, kidneys, and tumor were determined. The results showed that NADR substantially increased the ADR concentrations in liver, spleen, and tumor of rats compared to FADR, whereas the concentrations in plasma, heart, and lungs were significantly decreased. In conclusion, the body distribution of ADR can be modified by its encapsulation into nanoparticles and administration via the hepatic artery.

Animals↗
PubMed2004

CCAAT/enhancer binding protein alpha binds to the Epstein-Barr virus (EBV) ZTA protein through oligomeric interactions and contributes to cooperative transcriptional activation of the ZTA promoter through direct binding to the ZII and ZIIIB motifs during induction of the EBV lytic cycle.

The Epstein-Barr virus (EBV)-encoded ZTA protein interacts strongly with and stabilizes the cellular CCAAT/enhancer binding protein alpha (C/EBPalpha), leading to the induction of p21-mediated G(1) cell cycle arrest. Despite the strong interaction between these two basic leucine zipper (bZIP) family proteins, the ZTA and C/EBPalpha subunits do not heterodimerize, as indicated by an in vitro cross-linking assay with in vitro-cotranslated (35)S-labeled C/EBPalpha and (35)S-labeled ZTA protein. Instead, they evidently form a higher-order oligomeric complex that competes with C/EBPalpha binding but not with ZTA binding in electrophoretic mobility shift assays (EMSAs). Glutathione S-transferase affinity assays with mutant ZTA proteins revealed that the basic DNA binding domain and the key leucine zipper residues required for homodimerization are all required for the interaction with C/EBPalpha. ZTA is known to bind to two ZRE sites within the ZTA promoter and to positively autoregulate its own expression in transient cotransfection assays, but there is conflicting evidence about whether it does so in vivo. Examination of the proximal ZTA upstream promoter region by in vitro EMSA analysis revealed two high-affinity C/EBP binding sites (C-2 and C-3), which overlap the ZII and ZIIIB motifs, implicated as playing a key role in lytic cycle induction. A chromatin immunoprecipitation assay confirmed the in vivo binding of both endogenous C/EBPalpha and ZTA protein to the ZTA promoter after lytic cycle induction but not during the latent state in EBV-infected Akata cells. Reporter assays revealed that cotransfected C/EBPalpha activated the ZTA promoter even more effectively than cotransfected ZTA. However, synergistic activation of the ZTA promoter was not observed when ZTA and C/EBPalpha were cotransfected together in either HeLa or DG75 cells. Mutagenesis of either the ZII or the ZIIIB sites in the ZTA promoter strongly reduced C/EBPalpha transactivation, suggesting that these sites act cooperatively. Furthermore, the introduction of exogenous C/EBPalpha into EBV-infected HeLa-BX1 cells induced endogenous ZTA mRNA and protein expression, as demonstrated by both reverse transcription-PCR and immunoblotting assays. Finally, double-label immunofluorescence assays suggested that EAD protein expression was activated even better than ZTA expression in latently infected C/EBPalpha-transfected Akata cells, perhaps because of the presence of a strong B-cell-specific repressed chromatin conformation on the ZTA promoter itself during EBV latency.

Amino Acid Motifs↗
PubMed2004

Identification of a Kv3.4 channel in corneal epithelial cells.

PURPOSE: Voltage-gated K(+) channels maintain salt and water balance and normal function of corneal epithelial cells. To determine their identity, Kv channel types were sought in cultured rabbit corneal epithelial cells and in the intact rat corneal epithelium. METHODS: Immunohistochemistry and Western blot analysis were performed to detect K(+) channels in the membrane and cell lysates of rat and SV-40-transformed rabbit corneal epithelial (RCE) cells, using specific antibodies. The whole-cell patch clamp was used to characterize the biophysical and pharmacologic properties of the K(+) current in RCE cells. RESULTS: Expressions of K(+) channel types in corneal epithelial cells were detected by using a panel of specific anti-K(+) channel antibodies. Western blot analysis, using specific anti-K(+) channel antibodies including anti-Kv1.1, -2.1, -3.1, -3.2, -3.4, -4.2, and -4.3, demonstrated that in corneal epithelial cells Kv3.4 channel was highly expressed in whole-cell lysates and in cell membrane preparations. The anti-Kv3.4 channel antibody produced intense immunoreactivity in both RCE cells and rat corneal epithelium. Fluorescence immunostaining and avidin-biotin-peroxidase complex immunostaining confirmed localization of Kv3.4 channels in the cell membrane of both RCE and rat corneal epithelial cells. Voltage depolarization-activated K(+) currents in RCE cells were inhibited by applications of either 4-aminopyridine (4-AP, at micromolar levels), alpha-dendrotoxin at nanomolar levels, or blood-depressing substance-I at nanomolar levels. CONCLUSIONS: Biochemical and pharmacological profiles of the voltage-gated, 4-AP-sensitive K(+) channel in rat and RCE cells resemble characteristics of a Kv3.4 channel, a member of the Shaw subfamily. This channel may play important roles in maintaining normal function of corneal epithelium.

4-Aminopyridine↗
PubMed2004

[A study on occupational stress in commercial workers of a supermarket in Yinchuan].

OBJECTIVE: To study difference in occupational stress between men and women commercial workers in a supermarket in Yinchuan, Ningxia. METHODS: Totally, 679 commercial workers in a supermarket were investigated with questionnaire of occupational stress indicator (OSI), matched on age, length of service, educational level, marital status and type of work. RESULTS: Score of occupational stress factors, relationships, home/work balance and organizational atmosphere in women commercial workers was 143.48, 30.86, 20.82 and 15.16, respectively, obviously higher than that in men, with 134.89, 28.61, 18.75 and 13.93, respectively. Score of psychological health and satisfaction in women was 39.86 and 14.82, respectively, lower than that in men, with 43.84 and 17.66, respectively, which indicate that occupational stress in women was more severe with a more stressful psychological reaction than in men. Stepwise regression analysis showed that the main predicting factor for job satisfaction was personal relationships in women, and organizational atmosphere, managerial role and workload in men. Those for psychological health was control strategy and organizational atmosphere in women, and organizational atmosphere and recognition in men, those for physical illness was workload in women and support strategy and physical exercises in men, and those for stress level was support strategy in women and coping strategy in men. CONCLUSIONS: Women commercial workers experienced much more stress, with more severe stress reaction in their work, than men did. The main factors affecting occupational stress reaction and level of stress in women and men were not quite similar.

Adaptation, Psychological↗
PubMed2004

[Expression and activation of MAPK pathway signaling molecules in human breast cancer cell lines].

AIM: To detect the expression and status of extracellular regulatory kinase 1 and 2 (ERK1/2) and its upstream kinase MEK1/2 proteins in four breast cancer cell lines MCF-7, Bcap-37, SK-BR-3 and T47D and study the effects of cyclophosphamide and epirubicin on the growth of the cell lines and on the expression and status of the signaling molecules. METHODS: Western blot was used to examine the expression and status of MEK1/2 and ERK1/2 proteins in these cells and the effects of these two drugs on them. The effects of the two drugs on the proliferation of these breast cancer cell lines were detected by MTT colorimetry. RESULTS: The levels of expression and phosphorylation of MEK1/2 and ERK1/2 proteins in four breast cancer cell lines increased notably as compared with those in MCF-10 cells. Both drugs could inhibit the proliferation of breast cancer cells. And the levels of expression and phosphorylation of MEK1/2 and ERK1/2 proteins in breast cancer cell lines treated with the drugs were markedly lower than those in untreated breast cancer cells. CONCLUSION: Overexpression and phosphorylation of MEK and ERK may play an important role in the generation and development of human breast cancer. The inhibitory effect of cyclophosphamide and epirubicin on proliferation of the breast cancer cells may be by means of inhibiting expression and phosphorylation of MEK and ERK.

Antibiotics, Antineoplastic↗
PubMed2004

[Comparison among four kits in detection of anti-SARS-CoV IgG in sera of SARS patients].

OBJECTIVE: To compare the sensitivity and specificity of four kits for detection of anti-severe acute respiratory syndrome (SARS)-CoV IgG in sera of SARS patients. METHODS: Anti-SARS-CoV IgG was detected in 99 serial sera from 18 SARS patients and in 123 negative reference sera, using two enzyme linked immunosorbent assays (EIA No. A and No. B) and two indirect immunofluorescence assays (Australian IFA and Euroimmun IFA). RESULTS: Anti-SARS-CoV IgG was not detected in sera collected from SARS patients at the first week after onset by any of the four kits, however, it was detectable in sera obtained at the second week of illness by EIA No. B, and two IFA, but not by EIA No. A, with the positive rates of 57.1% (4/7), 57.1% (4/7) and 42.9% (3/7), respectively. The anti-SARS-CoV IgG was first determined in sera on the 9th day by Euroimmun IFA, 12th day by EIA No. B, 13th day by Australian IFA, and 16th day by EIA No. A. The positive rates of antibody on the 3rd week after onset were 84.2% (16/19), 94.7% (18/19), 78.9% (15/19) and 52.6% (10/19) respectively. They were identical since the 4th week after the disease onset. Through detection of 123 negative reference sera, the specificity of EIA No. A and two IFA was 100%, with exception of 94.9% for EIA No. B. CONCLUSION: The sensitivity and specificity of the two IFAs were relatively higher than that of the two EIAs. The quality of the two homemade EIAs should be improved.

Antibodies, Viral↗