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Biomedical subjects

Ling Zhang

Publications and source records attributed to Ling Zhang.

At least 145 records · Page 8Linked to original sources

[VEGF antisense oligonucleotide inhibits the expression of vascular endothelial growth factor in human leukemic cell lines].

OBJECTIVE: To explore the effects of vascular endothelial growth factor (VEGF) antisense phosphorothioated oligodeoxynucleotide (AS-ODN) on the expression of VEGF in human leukemic cell lines (HL-60 and K562 cells). METHODS: The levels of VEGF mRNA and protein in leukemic cells incubated with VEGF AS-ODN were measured by RT-PCR, immunohistochemistry assay and ELISA. MTT test was used to examine the influence of the culture supernatant (CS) of VEGF AS-ODN treated leukemic cells on the proliferation of human umbilical vein endothelial cells (ECV304). RESULTS: After leukemic cells were treated with different concentrations (2.5 approximately 15.0 micro mol/L) of VEGF AS-ODN for 24 h, VEGF mRNA level in the cells decreased remarkably in a concentration dependent manner, no change was found in the VEGF missense ODN treated cells (MS-ODN). When the leukemic cells were treated with 5 micro mol/L VEGF AS-ODN for 24 h, VEGF protein level decreased greatly both in the cells and in the CS; and the proliferation stimulating effect of the treated CS on the ECV304 cells reduced. Meanwhile, there was no obvious change in VEGF protein and its effect in the VEGF MS-ODN treated group. CONCLUSION: VEGF AS-ODN could inhibit VEGF expression in human leukemic cell lines in vitro.

Enzyme-Linked Immunosorbent Assay↗

[Changes of compliance in tensional anastomotic arteries].

The data of arterial pressure and diameter were measured in vivo before and after normal anastomosis and tensional anastomosis in canine femoral arteries at different time intervals. The arterial compliance was calculated, and the exponential form C = bemPa was employed to fit the compliance (C)- average pressure (Pa) curve. The relationship between compliance and average pressure was determined. The results showed that the compliance of arteries decreased after anastomosis, and the compliance of arteries after tensional anastomosis was lower than that of normal anastomosis at different time intervals. It was decreased most markedly at 14 days after tensional anastomosis. This indicated that the distensibility of tensional anastomotic artery was decreased more markedly than that of normal anastomotic artery. The function of artery was evidently affected by tensional anastomosis.

Anastomosis, Surgical↗

[Advances in the research of sperm protein 17].

Sperm protein 17 (Sp17) is a testis-specific protein involved in acrosome reaction in spermatozoa. However, the Sp17 gene has been recently detected in normal non-testis tissues and malignant neoplasias. Therefore Sp17 may be a potential target for immunocontraception and a suitable target for tumor immunotherapy. This paper reviews the advances in the protein characterization, expression and distribution, and biological function of Sp17 and its clinical research.

Animals↗

Finding potential ligands for PDZ domains by tailfit, a JAVA program.

OBJECTIVE: To deduce all potential ligands undiscovered experimentally by searching all the proteins containing same C-termini, which can bind a certain PDZ domain. METHODS: We developed a JAVA program for searching short exact sequence matches at C-terminus. According to the known C-termini, which PDZ domains recognized experimentally, Swissprot database has been searched by this program for all potential ligands. RESULTS: Some PDZ domains may have more potential ligand proteins, which are undiscovered yet experimentally. These bioinformatic results also provide clues for studying functions of hypothetical proteins and PDZ domains' protein interactions in many different organisms. CONCLUSION: The results may provide useful clues for discovering potential functions of hypothetical proteins and new functions of known proteins.

Amino Acid Sequence↗

[Early diagnosis of prostate cancer using free/total prostate-specific antigen ratio with population-based screening data].

OBJECTIVE: To evaluate the use of free/total prostate-specific antigen ratio (fPSA/tPSA ratio) in improving the early diagnosis of prostate cancer. METHODS: fPSA/tPSA ratio in the serum was analyzed prospectively in 187 men with tPSA ranging between 4.0 and 20.0 microg/L. All of them underwent ultrasound-guided sextant prostatic biopsies. Sensitivity, specificity, positive and negative predictive values were calculated by SPSS 10.0 software. RESULTS: Prostate cancer detection rates were 18.1% and 22.5% when tPSA was within the ranges of 4.0-10.0 g/L and 10.0-20.0 g/L respectively. fPSA/tPSA ratio was more significant than tPSA in all the men. When the cut-off value of fPSA/tPSA ratio was set at 0.25, 90.5% and 87.5% of cancers could be detected; and 26.7% and 11.3% of biopsies could be avoided within the tPSA ranges of 4.0-10.0 g/L and 10.0-20.0 g/L, respectively. CONCLUSION: The use of fPSA/tPSA ratio can improve prostate cancer detection and reduce unnecessary biopsies when tPSA is within the range of 4.0-10.0 microg/L and 10.0-20.0 microg/L.

Aged↗

[Quality evaluation of prepared slices of Paeonia lactiflon--determination of paeoniflorin by HPLC].

OBJECTIVE: To establish the quality criteria of the prepared slices of Paeonia lactiflon. METHOD: RP-HPLC was used for the determination of paeoniflorin in 10 lots of samples by ultrasound-assisted extraction. RESULT: The samples were extracted with 50% methanol. Seperation of the solution was performed on an ODS column with a mobile phase of acetonitrile-water (18:82), detected at 230 nm. CONCLUSION: The method is simple, repeatable, accurate and applicable.

Benzoates↗

Two hundred and fifty-eight cases of hemoptysis treated by injection of vitamin K3 into Chize point.

Injection of vitamin K3 into Chize (LU 5) was used from 1980 to 1992 in 258 inpatients suffering from diseases of the respiratory system accompanied with hemoptysis. As a result, the effective rate was 83% for mild hemoptysis and 72.1% for moderate hemoptysis in the treatment group, as compared to 48.5% and 45.2% respectively in control group A, and to 83.8% and 75% in control group B. There was a significant difference between the treatment group and control group A (P < 0.01). However, the effective rate was only 31.8% for severe hemoptysis in the treatment group, as compared to 81.3% in control group B with a significant difference. It is therefor concluded that injection of vitamin K3 into Chize is a good therapy for mild or moderate hemoptysis but not for severe cases.

Acupuncture Points↗

[Effect of EBV encoded BARF1 gene on malignant transformation of human epithelial cell line HBE].

BACKGROUND & OBJECTIVE: The BARF(1) (BamHI A right frame1)gene,encoded by Epstein-Barr virus(EBV),may have oncogenic properties,which leaded to immortalization of a monkey kidney epithelial cell line and malignant transformation of human B lymphocytes and murine fibroblasts. This study was designed to evaluate effect of BARF(1) on cell transformation and tumorgenesis on human epithelia and its mechanisms. METHODS: BARF(1) was amplified from B95-8 cell line by polymerase chain reaction (PCR). Eukaryotic recombinant vector pcDNA(3)-BARF(1) was constructed,and transfected into human bronchial epithelial cell line HBE,and expression of BARF(1) in the transfected cells was detected by Western blot. Growth status,proliferation rate,ability of colony formation in soft agar,and tumorigenicity of HBE cells transfected with BARF(1) were studied. RESULTS: BARF(1) gene promoted proliferation and transformation of HBE cells. After injected with 1 x 10(7) HBE cells transfected with BARF(1),tumor nodes were observed in 2 of 6 mice at the 10th day. CONCLUSION: BARF(1),as a virus oncogene,may play an important role in malignant transformation of HBE cells.

Animals↗

[Studies on the genetic pathogenesis of myasthenia gravis caused by CTLA-4 gene polymorphism].

OBJECTIVE: To study the genetic pathogenesis of myasthenia gravis (MG) caused by cytotoxic T lymphocyte associated antigen-4 (CTLA-4) gene polymorphisms and regulation function of transcription factor. METHODS: ELISA assay was used to determine the expression level of serum sCTLA-4 in MG. Four single nucleotide polymorphisms (SNPs) of CTLA-4 at exon 1 +49, promoter -318, -1661, -1772 were analyzed by restriction fragment length polymorphism (RFLP). Transcription factor nuclear factor 1(NF-1) and c/EBPbeta binding site were confirmed by chromatin immunoprecipitation(CHIP) assay. RESULTS: It was found that the frequencies of the GG+49 genotype and G+49 allele are higher in MG patients with thymoma than those in patients of thymic hyperplasia and normal thymus subgroups. T/C-318 is not correlated with MG. The frequency of CT-1772 genotype is significantly higher in MG patients, especially in MG patients with thymoma, when compared with that in healthy controls. Meanwhile, the frequency of the G-1661 allele and GG-1661 genotype is lower in MG patients. Linkage disequilibrium (LD) between each SNPs in promoter -1772, -1661, -318 and coding sequence 1 (CDS 1) +49 is apparent. sCTLA-4 levels in patients' sera are correlated with the haplotype and genotype. T/C-1772 and A/G-1661 SNPs change the sequence of transcription factor NF-1 and c/EBPbeta binding sites. DNA variants lose site-specific binding activity of transcription factor regulated by lectin ConA and PHA. CONCLUSION: There are strong positive linkages among four SNPs. C/T-1772 and A/G-1661 polymorphisms can result in inefficient transcription of CTLA-4 gene. T>C-1772 mutation also affects gene splicing. These SNPs may constitute a factor of susceptibility to disease.

Adolescent↗

[Determination of psoralen and isopsoralen in Psoralea corylifolia L. from different habitats].

OBJECTIVE: To study the psoralen and isopsoralen content in Psoralea corylifolia from different habitats. METHOD: C18 column was used. Mobile phase was methanol-water (45:55). The detection wavelength was at 245nm and the flow rate was 1.0 ml/min. RESULT: The linearity was obtained over the range of 0.448 to approximately 0.448 microg (r = 0.9999) for psoralen, 0.356 to approximately 0.356 microg = 0.997) for isopsoralen. CONCLUSION: The contents of psoralen and isopsoralen in Psoralea corylifolia from different habitats have no obvious difference.

Chromatography, High Pressure Liquid↗

[Expression and significance of PTEN and caspase-3 in laryngeal squamous cell carcinoma].

OBJECTIVE: To elucidate the expression and significance of PTEN and Caspase-3 in laryngeal squamous cell carcinoma. METHOD: Immunochemical method was used to study 289 cases of laryngeal carcinoma, including 60 cases atypical hyperplasia of vocal fold and 20 cases of normal laryngeal tissues. RESULT: The PTEN gene was expressed in 58.8% laryngeal carcinoma tissues, in 86.7% atypical hyperplasia of vocal fold and 100.0% normal laryngeal tissues. The differences were significance (P < 0.05). The Caspase-3 was expressed in 48.1% laryngeal carcinoma tissues, in 61.7% atypical hyperplasia of vocal fold and in 85.0% normal laryngeal tissues. The differences were significance (P < 0.05). In addition, there was a positive correlation between the expression of Caspase-3 and PTEN (P < 0.01). CONCLUSION: Expression of PTEN and Caspase-3 in laryngeal carcinoma is different from that of normal laryngeal tissues, which may play an important role in the tumorigenesis and development of laryngeal carcinoma.

Adult↗

L-arginine reverses p47phox and gp91phox expression induced by high salt in Dahl rats.

Derangements in the production and degradation of reactive oxygen species (ROS) as well as nitric oxide (NO) have been implicated in cardiovascular diseases. We explored how supplementation with l-arginine, an NO synthase substrate, restores such derangements of ROS/NO systems in Dahl salt-sensitive, hypertensive (DS) rats. We detected an increase of NADPH oxidase activity, a key enzyme that produces superoxide, in the membrane fraction of the renal cortex derived from DS rats loaded with high salt for 4 weeks; high salt loading also remarkably increased urinary H2O2, 8-isoprostane, and thromboxane B2 excretion and decreased plasma NO end products. These changes from high salt loading were counteracted by oral l-arginine supplementation. We further examined expression patterns of NADPH oxidase subunits in renal cortex derived from these animals. High salt loading increased gp91phox and p47phox but not p22phox or Rac1 or mRNA abundance, which were counteracted with L-arginine supplementation. Western blot analyses after subcellular fractionation revealed that l-arginine supplementation distinctly decreases membrane localization of p47phox protein, as it decreases total expression of Rac1 protein in DS rats with high salt loading. These results disclose that high salt loading causes a deficiency in available L-arginine amounts for NO synthases and induces NADPH oxidase activation in the renal cortex of DS rats, which l-arginine supplementation markedly restores. Since superoxide rapidly eliminates NO, which inhibits sodium reabsorption in the cortical collecting duct, superoxide production caused by upregulated NADPH oxidase activity in the renal cortex of high salt-loaded DS rats may accelerate sodium reabsorption and hypertension.

Animals↗

Nonradioactive iodide effectively induces apoptosis in genetically modified lung cancer cells.

We assessed a nonradioactive approach to induce apoptosis in non-small cell lung cancer by a novel iodide uptake and retention mechanism. To enhance tumor apoptosis, we transduced non-small cell lung cancer cells with retroviral vectors containing the sodium iodide symporter (NIS) and thyroperoxidase (TPO) genes. Expression of NIS and TPO facilitated concentration of iodide in tumors. As a consequence of the marked increase in intracellular levels of iodide, apoptosis was seen in >95% of NIS/TPO-modified lung cancer cells. Intraperitoneal injection of potassium iodide resulted in significant tumor volume reduction in NIS/TPO-modified tumor xenografts without apparent adverse effects in SCID mice. Iodide induced an increase in the level of reactive oxygen species. Iodide-induced apoptosis is sensitive to N-acetylcysteine inhibition, suggesting an important role by reactive oxygen species in this apoptotic process. In addition, iodide-induced apoptosis is associated with overexpression of CDKN1A (p21/Waf1)and down-regulation of survivin at both mRNA and protein levels. This is the first report demonstrating that a therapeutic dose of nonradioactive iodide has potent efficacy and high selectivity against lung cancer when used in combination with genetic modification of cancer cells to express the NIS/TPO genes.

Acetylcysteine↗

[Pathological features of prostate cancer in Chinese cohort detected through mass screening and their relationships with serum prostate specific antigen].

OBJECTIVE: To investigate the pathological features of the prostate biopsy through mass screening for prostate cancer in Chinese cohort and their relationships with serum prostate specific antigen (PSA). METHODS: ELISA was used to measured the serum PSA in 12 027 Chinese men aged 50 and over in Changchun, Jilin Province. Transrectal ultrasound guided six-sextant biopsy was performed on 137 cases with the serum PSA value > 4.0 micro g/L and 21 cases with the serum PSA < 4.0 micro g/L but with urethral obstructive symptoms. Pathological analysis was done with the aid of statistic software SPSS 10.0. RESULTS: Of the 158 biopsies, 41 cases of prostatic carcinoma were found (25.9%, 41/158). The moderately differentiated carcinoma and poorly differentiated carcinoma accounted for 61% and 34% respectively. In these 41 cases of prostate cancer, a significant linear positive correlation between the serum PSA and the Gleason score (r = 0.329, P < 0.05) and a significant linear positive correlation between the serum PSA and the positive counts of carcinoma in six-sextant biopsy (r = 0.425, P = 0.006) were found. CONCLUSION: The moderately differentiated carcinoma is the most common type of prostate cancer. The approach of mass screening opens a new avenue for the early detection of prostate cancer. Serum PSA value is not only associated with the pathological grading but also with the extension of tumor.

Biopsy, Needle↗

A virtual reality environment for evaluation of a daily living skill in brain injury rehabilitation: reliability and validity.

OBJECTIVE: To establish the stability and validity of information collected in a virtual reality environment from persons with traumatic brain injury (TBI). DESIGN: Prospective correlation design to examine 3-week test-retest results for equivalence reliability between computer-simulated and natural environments. SETTING: A residential rehabilitation center for brain injury. PARTICIPANTS: Fifty-four consecutive patients with TBI who received comprehensive rehabilitation services and who were at different stages of recovery. INTERVENTION: An immersive virtual kitchen was developed in which a meal preparation task involving multiple steps was performed. The subjects completed meal preparation both in a virtual reality kitchen and an actual kitchen twice over a 3-week period. MAIN OUTCOME MEASURES: Time and errors on task completion using virtual reality assessment, actual kitchen performance (analogous to the virtual reality environment), occupational therapy (OT) evaluation, and neuropsychologic tests. RESULTS: The stability of performance using the simulated virtual environment was estimated with intraclass correlation coefficients (ICCs). The ICC value for total performance, based on all steps involved in the meal preparation task, was.76 (P<.01). The construct validity of the simulated environment was examined by correlating performance in the virtual environment with that in the actual kitchen (r=.63, P<.01), the OT evaluation (r=.30, P=.05 for meal preparation; r=.40, P=.01 for cognitive subskills), and neuropsychologic tests (r=.56, P<.01 for the full-scale intelligence quotient [IQ]; r=.40, P<.01 for the verbal IQ; r=.56, P<.01 for the performance IQ). Finally, a multiple regression analysis revealed that the virtual reality environment test was a good predictor for the actual assessment kitchen (beta=.35, P=.01). CONCLUSION: The virtual reality system showed adequate reliability and validity as a method of assessment in persons with brain injury.

Adolescent↗

Mechanism of activation of human peripheral blood NK cells at the single cell level by Echinacea water soluble extracts: recruitment of lymphocyte-target conjugates and killer cells and activation of programming for lysis.

Echinacea purpurea, a plant originally used by native Americans to treat respiratory infections, has also been shown to exert immunomodulatory activities both in vivo and in vitro. However, the mechanism underlying Echinacea-induced immunomodulation remains largely unknown. This study examined in vitro the effects of soluble extracts of E. purpurea on natural killer (NK) cells present in human peripheral blood mononuclear cells (PBMC). Flow cytometric methods were used to examine activation, cytotoxicity, NK-target binding, and killer cell frequency. Treatment of PBMC with Echinacea overnight resulted in the activation of CD69 expression and increase in mean fluorescence intensity in both the CD16+ and CD16+CD56+ NK subsets. However, the frequency of CD16+ cells was decreased as well as the mean fluorescence intensity was down-regulated. NK cytotoxicity was augmented 100% at the concentration of 0.1 microg/ml of Echinacea in a short time (4-h) assay. Examination at the single cell level revealed augmentation of the frequency of CD56+ NK-target conjugates and a plateau was reached after 30-60 min of incubation. Likewise, the frequency of CD56+ killer cells in the conjugates was also significantly increased by Echinacea. There was recruitment of non-conjugated CD56+ cells into CD16+ NK-target conjugates and activation of the NK-target non-killer conjugates into killer cells. These findings demonstrate that Echinacea extracts are potent activators of NK cytotoxicity. Echinacea augments the frequency of NK target conjugates and activates the programming for lysis of NK cells.

Antigens, CD↗

Induction of LOX-1 and iNOS expressions by ischemia-reperfusion of rat kidney and the opposing effect of L-arginine.

Lectin-like oxidized low-density lipoprotein receptor (LOX-1) is a newly identified endothelial cell surface major receptor for oxidatively modified low-density lipoprotein. Progression of arthrosclerosis in the donor organ after organ transplantation is a major problem. We hypothesized that ischemia-reperfusion induces LOX-1. After 1 h ischemia of bilateral kidneys plus 3, 6, or 12 h reperfusion, we first revealed that LOX-1 mRNA expression was increased in renal cortex and medulla at 6 h after reperfusion, which was decreased by L-arginine supplement. Plasma nitric oxide (NO) end-product nitrite plus nitrate and inducible nitric oxide synthase (NOS) expression were increased after reperfusion of 6 h. However, NOS substrate L-arginine did not augment but markedly decreased plasma NO end product, because L-arginine supplement suppressed inducible NOS expression in kidney. We hypothesized that available L-arginine is depleted by ischemia-reperfusion, leading to inducible NOS induction. Ischemia decreased L-arginine levels in kidney and L-arginine supplement increased NO end products in renal cortex in the earliest phase of reperfusion. These results disclosed for the first time that a deficiency in L-arginine by ischemia reperfusion causes uncoupling of constitutive NOS, which induces inducible NOS and LOX-1, implying why L-arginine is effective for stroke or transplantation in preventing atherosclerotic progress.

Animals↗