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Biomedical subjects

Li Zhang

Publications and source records attributed to Li Zhang.

At least 361 records · Page 20Linked to original sources
PubMed2005

[Diagnosis of thalassemia by using genechips].

OBJECTIVE: The new technology of genechip is exerting a significant impact on the identification of thalassemia, and allows to rapidly and efficiently detect a number of molecular disorders. The aim of the present study was to explore the application value of the diagnostic genechip in determining thalassemia. METHODS: The subjects group consisted of 62 children with alpha thalassemia and 93 children with beta thalassemia (60 with thalassemia trait, 33 with thalassemia major) from Guangdong province were tested from July 2002 to July 2003; 115 were males and 40 were females, the age ranged from 1 day to 11 years. These children had mild, moderate or severe anemia. Laboratory examinations showed microcytosis and hypochromocytosis. DNA was extracted from ACD coagulated blood with Invisorb DNA extraction kit. After preparation, the alpha and beta globin gene organization and structure of sample was analyzed by genechip technology. RESULTS: (1) Heterozygotes, homozygotes and compound heterozygotes of the three commonest deletional alpha thalassemia (--(SEA), -alpha(3.7), -alpha(4.2)) and two non-deletional alpha thalassemia (HbCS, HbQS) were successfully detected. (2) Eight different mutations were identified in 126 chromosomes among 60 cases with beta thalassemia traits and 33 cases with beta thalassemia major, namely CD41-42, IVS-II-654, TATAbox-28, CD17, CD71-72 (+A), betaE(26) CD27-28 (+C) and CD71-72 (+T), with the frequencies of 33.5%, 23.9%, 15.0%, 15.0%, 4.8%, 2.4%, 2.4% and 1.5% respectively. (3) Eight cases (13.3%) in 60 thalassemia traits, two cases (6%) 33 cases with thalassemia major were detected to be combined with alpha thalassemia mutation. CONCLUSION: (1) The usage of genechip in identifying thalassemia mutations has the advantages of simplicity, economy and shorter time. This technique does not use radioisotope and could also detect alpha and beta thalassemia mutations simultaneously. (2) The occurrence of alpha and beta thalassemia dual heterozygotes is frequent in Guangdong province and the genechip technology is important in genetic counseling and prenatal diagnosis of thalassemia in this area.

Child↗
PubMed2005

[Relationship of serum level of dihydropyrimidine dehydrogenase and serum concentration of 5-fluorouracil to treatment response and adverse events in colorectal cancer patients].

BACKGROUND & OBJECTIVE: Toxicities and response are different when patients with advanced colorectal cancer were treated with standard FOLFOX6 regimen. Serum level of dihydropyrimidine dehydrogenase (DPD) relates to efficacy and toxicities of chemotherapy containing 5-fluorouracil (5-FU). This study was to explore relationship of DPD to serum concentration of 5-FU in colorectal cancer patients treated with FOLFOX6 regimen, and their correlation to treatment response and adverse events. METHODS: Serum level of DPD in 72 patients with colorectal cancer was detected by high-performance liquid chromatography (HPLC) before chemotherapy. Serum concentration of 5-FU at steady state was detected by HPLC after patients received FOLFOX6 regimen. Treatment response and adverse events in the patients were assessed. RESULTS: Serum levels of DPD were normally distributed in 72 patients (ranged 1.55-5.94), while serum concentrations of 5-FU at steady state were not (ranged 141.1-1 741.9 microg/L). Serum level of DPD was negatively correlated with serum concentration of 5-FU (r=-0.460, P < 0.01). Occurrence of adverse events was lower when 5-FU concentration was less than 600 microg/L than when 5-FU concentration was more than 600 microg/L (P < 0.05). The mean serum concentration of 5-FU was significantly higher in patients with complete response and partial response than in patients with steady disease, and progressive disease (513.9 microg/L vs. 409.8 microg/L, and 259.3 microg/L, P < 0.05). Serum level of DPD was lower in patients suffered oral mucositis and diarrhea of grade II-IV than in patients suffered oral mucositis and diarrhea of grade 0-I (P=0.016, P=0.047). Serum level of DPD had no relation with treatment response of the patients (r=0.312, P=0.078). CONCLUSIONS: DPD level and serum 5-FU concentration vary a lot among patients with colorectal cancer. DPD level negatively correlates with serum 5-FU concentration. Serum concentration of 5-FU correlates with treatment effect and toxicities.

Adult↗
PubMed2005

[Effect of expression of coxsackie and adenovirus receptor on antitumor activity of genetically modified adenovirus].

BACKGROUND & OBJECTIVE: The effect of adenovirus, a kind of oncolytic virus and a kind of carrier in gene therapy, depends on the expression of Coxsackie and adenovirus receptor (CAR) on cell surface to a large degree. This study was to evaluate relationship of CAR expression to infectivity and efficacy of adenovirus. METHODS: Pathologic specimens from 29 patients in a clinical trial of genetically modified adenovirus (H101) were collected. Expression of CAR in cancer tissues was detected by immuohistochemistry. Expression of CAR on cancer cell membrane was detected by flow cytometry (FCM). Inhibitory effect of H101 on cells was assessed by MTT assay. RESULTS: Positive rate of CAR was significantly higher in patients achieved complete remission (CR) or partial remission (PR) than in patients had stable disease (SD) or progressive disease (PD) [70.0% (7/10) vs. 31.6% (6/19), P=0.048]. CAR expression on different cells was different, and the amount of CAR was positively related to virus infectivity, presented as the inhibitory rate of H101-infected cells (r=0.986). CONCLUSIONS: The expression of CAR closely relates to antitumor activity and efficacy of adenovirus. Also, the efficacy of adenovirus is higher on cancers with increased CAR expression than on those with decreased CAR expression.

Adenoviridae↗
PubMed2005

[FTIR spectroscopic explorations of clinical practice of breast cancer].

The authors detected ten normal breast tissue samples and eight breast cancer samples by FTIR spectroscopy with an ATR probe. Nineteen variables of thirteen bands in the spectra were compared using standard statistic methods. The results demonstrated that bands of protein, lipid, carbohydrate, and nucleic acid from cancerous samples were significantly different from those from normal ones: (1) The relative intensity of N-H band increased and amide I band shifted to lower wave number significantly; (2) Symmetric and antisymmetric vibrations of -CH2 group, C=O vibration, and relative intensity of (-CH2)n decreased; (3) The intensity of 1160 cm(-1) band was much weaker than that of 1120 cm(-1); (4) The band of P=O or P-O-C shifted toward lower wave number. The authors believe that FTIR spectroscopy has a promising future in breast cancer diagnosis.

Breast↗
PubMed2005

[Preparation of Ce-loaded nano-TiO2 and study on its UV-Vis reflective spectrum].

Ce-loaded nano-TiO2 was prepared by the loading technology of metallic ions, and was characterized by XRD and TEM. The UV-Vis reflective spectra of nano-TiO2 and Ce-loaded nano-TiO2 were analyzed. The result shows that after loading rare earth element Ce the reflective spectral characteristic of nano-TiO2 moves to the visible region with a red shift to 500 nm, and the obvious change takes place in the absorbance in the visible spectral range with a three-fold enhancement. It is indicated that the load of rare earth element Ce is favorable to enhancing the absorption of visible and UV light of anatase nano-TiO2, and thereby greatly increases its photocatalytic activity.

Cerium↗
PubMed2005

[Sensitivity and specificity analysis of the lineage related antibodies in acute leukemia immunophenotyping by flow cytometry].

To evaluate the sensitivity and specificity analysis of the lineage related antibodies in acute leukemia immunophenotyping by flow cytometry (FCM), immunophenotyping in 184 patients with acute leukemia was performed by FCM analysis. The results showed that in the lineage-related antibodies of acute myelocytic leukemia (AML), the sensitivity of CD13 and CD33 was higher (95.5% and 91.2%, respectively), the specificity of them was deficient (72.5% and 62.2%, respectively); the sensitivity of MPO was low (69.1%), but the specificity was high (100%); the sensitivity and specificity of CD117 were high (88.2% and 100%, respectively); the sensitivity of CD14 and CD15 was low (18.4% and 27.2%, respectively); the specificity of CD14 with monocytes was high. As the lineage-related antibodies of B-lineage ALL were concerned, CD19 showed high sensitivity and low specificity (100% vs 83.4%); the sensitivity and specificity of CD79a (96.4% vs 100%) and CD22 (100% vs 100%) were high; the sensitivity and specificity of CD10 (53.6% vs 82.5%) and CD20 (70.4% vs 87.5%) were low. In T-lineage ALL, the specificity of CD3 was high (97.5%), but the sensitivity was below the mark (80.0%); the sensitivity of CD7 was high (100%), but the specificity was low (77.9%); while the sensitivity and specificity of CD5, CD2 and CD1a were all deficient. In conclusion, the sensitivity and specificity analysis of the lineage-related antibodies in acute leukemia immunophenotyping are coincident with St Jude immunophenotyping project. It seems only that CD117 is superior to MPO in defining AML, but the sensitivity and specificity analysis of CD22 and CD79 are similar in defining B-lineage ALL, therefore, anyone of them may be selected as your need.

Acute Disease↗
PubMed2005

[Neonatal murine keratinocytes split express CD80/CD86 upon culture].

It was previously thought that keratinocytes did not express the CD80 and CD86 which provide the most important costimulatory signals for the antigen-specific T-cell activation. The cultured keratinocytes allografts were initially accepted, but eventually, all grafted donor cells were gradually replaced by recipient cells. The precise mechanisms are not very clear. In this study, neonatal murine keratinocytes were cultured for 7 days, the results of flow cytometry and confocal microscopy showed that CD80 could be detected on keratinocytes, while CD86 could not be detected all the time. RT-PCR analysis confirmed this result. The expression level of the CD80 mRNA amplified significantly from day 1 to day 7, as expression of the control beta-actin, but CD86 was not detected. Mixed Lymphocyte Reaction (MLR) showed that keratinocytes cultured with 10% serum for 7 d stimulated effectively allogeneic rather than syngeneic T cell proliferation. This study demonstrated for the first time that costimulatory molecule CD80 can be expressed on keratinocytes in vitro. These data provided an alternative explanation for the ultimate rejection of allogeneic keratinocytes in which keratinocytes act as antigen-presenting cells.

Animals↗
PubMed2005

[Feasibility of stem cells transplantation through aorta in adriamycin-induced heart failure].

Stem cells transplantation is a promising strategy for treating myocardial infarction and/or chronic heart failure; however, with respect to nonischemic heart failure, there are some limitations inherent in the current methods of transplantation. In this study, we investigated the feasibility of a novel method, i. e. transplantation through the root of aorta when the ascending aorta occluded above the sinus aortae. Japanese white ears rabbits were used as chronic heart failure models by intravenous injection of adriamycin. Autologous bone marrow mononuclear cells (MNC) were infused into the root of aorta when the ascending aorta was occluded by a couple of balloons above the sinus aortae. After 4 weeks, ejection fraction was significantly improved in MNC group. In conclusion, we have developed a unique method for efficient and safe cell transplantation based on infusion in aorta. This method, potentially suitable for nonischemic heart failure and could be used to achieve even and global supply of cells in heart.

Animals↗
PubMed2005

[The effect of Helicobacter pylori eradication therapy on bismuth absorption of colloidal bismuth subcitrate].

OBJECTIVE: To investigate whether the acid suppression therapy influences the absorption of bismuth from colloidal bismuth subcitrate (CBS); to locate the deposit position of bismuth in mice's organs and to detect the consequential change of cell functions in these deposited organs. METHODS: 48 male SD rats weighing from 200-250 g were randomly divided into five groups: Group A(1), kill the rats on the cessation day of administration CBS; Group B(1), kill the rats on the day 8 weeks after the cessation of administration CBS; Group A(2) (CBS + amoxicillin + metronidazole + omeprazole), kill the rats on the cessation day of administration; Group B(2) (CBS + amoxicillin + metronidazole + omeprazole), kill the rats on the day 8 weeks after the cessation of administration; Control group. These medicines had been taken every day for 14 days. The issue sections (liver, brain and kidney) were counterstained after AMG development. The bismuth deposited in tissues was observed by microscopy. At the same time, the gray level of kidney tissue sections were measured and compared through image processing program. The deposition of bismuth and the degrees of cell organ's impairment were observed through electron microscopy. By the use of electron probe microanalysis, bismuth can be distinguished from chemical element. RESULTS: The bismuth can be accumulated in cell bodies of proximal convoluted renal tubule, portal area, hypothalamus, and hypoglossal nuclei after its absorption. Under the light microscopy, heavy AMG staining granules were found in cell bodies of proximal convoluted renal tubule. It was discovered that the amounts of bismuth accumulation in kidney of quadruple therapy group were much more than that of single compound therapy group (P < 0.05). The amounts of bismuth accumulation in kidney on the cessation day of administration are more than that 8 weeks later (P < 0.01). What is more, under the electron microscopy, heavy AMG staining granules were found exclusively in lysosomes of proximal convoluted renal tubule cell. The electron microscopy found some cell impairment in quadruple therapy group: the impairment to these cells can be recovered 8 weeks after the cessation of administration. CONCLUSIONS: The acid suppression therapy causes an increase of bismuth absorption and accumulation from CBS in the rats' kidney. Finally, the absorbed bismuth can be discharged out of the body via kidney. Large amounts of bismuth accumulation in kidney can impair the functions of proximal convoluted renal tubule cell.

Absorption↗
PubMed2005

[Study on the level of placental urocortin and corticotropin-releasing hormone receptor 2beta of preeclampsia].

OBJECTIVE: To determine the relation between the expression of urocortin and corticotropin-releasing hormone receptor 2beta (CRH-R2beta) in the placenta and pathogenesis of preeclampsia. METHODS: Placentas were collected from 20 pregnant women with preeclampsia as study group and 20 normal pregnant women as control group. Urocortin mRNA and CRH-R2beta mRNA were measured by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Urocortin peptide was measured by immunohistochemistry. RESULTS: (1) The mRNA expression of urocortin was significantly higher (P < 0.05) in preeclampsia (1.14 +/- 0.26) compared with normal pregnancies (0.78 +/- 0.46). (2) There was no significant difference between the expression of CRH-R2beta mRNA of preeclampsia (0.89 +/- 0.33) and of normal pregnancies (0.93 +/- 0.50). (3) The result of immunohistochemistry demonstrated that urocortin was predominantly localized in syntrophoblast with weak staining in cyntrophoblast and capillaries. Urocortin in syntrophoblast of preeclampsia was significantly higher than that of normal pregnancy (P < 0.05). CONCLUSIONS: Our study demonstrates that urocortin peptide and mRNA is increased in women with preeclampsia. This may be a kind of stress-responsive compensatory mechanism in human placenta. Urocortin may play a role in the pathology of the disease.

Adult↗
PubMed2005

[An 1-year prospective cohort study on mortality of injecting drug users].

OBJECTIVE: To study the mortality among injecting drug users (IDUs) from an IDUs cohort in Liangshan of Sichuan province. METHODS: In November 2002, 376 injecting drug users were recruited and followed up for 1 year as part of a prospective cohort study. Socio-demographics and risk behaviors on drug use were recorded. After one year, the mortality rate was estimated and risk factors for mortality were analyzed using Cox regression. RESULTS: Out of the original cohort of 376 participants, there were 28 reported and confirmed deaths during the one year follow-up period. The mortality rate of the cohort was 77.32 per 1000 person-years (95% CI: 48.68 - 105.95) with the standardized mortality ratio (SMR) as 47.62 (95% CI: 31.63 - 68.71). Out of the 28 deaths, 64.3% (18/28) caused by overdoses of drug. No variables were found to be associated with death of all causes, but being un-married and >or= 9 year history of injecting drugs were found to be associated with overdose-related mortality in the final model of Cox regression. The hazard ratios were 4.51 (95% CI: 1.03 - 19.67) and 2.77 (95% CI: 1.10 - 7.00) respectively. CONCLUSION: Overdose served the most frequent cause of deaths in Liangshan of Sichuan province. Future studies should be conducted to focus on mortality and risk factors associated with mortality among IDUs to provide targeted interventions in reducing unnatural mortality.

Adult↗
PubMed2005

[Relation between angiogenesis, fibrinolysis and invasion/metastasis in breast cancer].

OBJECTIVE: To investigate the relation between angiogensis, fibrinolysis and invasion/metastasis in breast cancer. METHODS: The expression of urokinase-type plasminogen activator (uPA) and microvascular density (MVD) was immunohistochemically studied in 110 patients with primary breast cancer. RESULTS: High uPA expression was found in 59 patients (53.6%), and weak expression in 51 patients (46.4%). Strong MVD expression was found in 53 patients (48.2%), and weak expression in 57 patients (51.8%). The correlation between uPA expression and tumor size, lymph node status, TNM stage was statistically significant. Expression of MVD was also significantly associated with tumor size and TNM stage. Neither age related to GDDP, menopausal status nor PR ER status was significantly with uPA and MVD expression. Patients with strong expression of uPA and/or MVD had a significantly shorter relapse-free survival than those with weak expression of uPA and/or MVD. Especially, patients with strong expression of both uPA and MVD were likely to develop recurrence and metastasis. Multivariate analysis showed that uPA and MVD were two independent prognostic factors affecting the relapse-free survival. CONCLUSION: Angiogensis and fibrinolysis were closely associated with invasion and metastasis of breast cancer. uPA and MVD may be two strong and independent biologic markers in predicting postoperative relapse and metastasis of breast cancer.

Adult↗
PubMed2005

[Effect of glucose on biofilm and the gene ica expression in Staphylococcus epidermidis with different biofilm-forming capability].

The infection of S. epidermidis, an opportunistic human pathogen, depends on biofilm formation, and biofilm formation is closely related to environment. Researches in the thesis focused on two strains of S. epidermidis with different capability of biofilm formation. To find the mechanism of response to environment on biofilm formation, biofilm formation and expression of ica, icaR, AtlE in theses S. epidermidis cultivated in different grow environment and in media with glucose for different time were assayed. Glucose can induce the biofilm formation by inducing ica gene, but the inducing do not need continued ica expression, and other genes also contribute to the regulation; anti-ODN specially binding icaADBC can withstand biofilm inducing from glucose. These results suggest that biofilm formation closely related to growth environment, which is a complex regulation mechanism. Biofilm formation is closely related to bacteria energy metabolism and cell wall synthesis. Some crucial factors in the complex and integrated regulation system have not been known yet.

Biofilms↗
PubMed2005

[Patterns of spasmodic dysphonia and botulinum toxin injections].

OBJECTIVE: To investigate the patterns of spasmodic dysphonia and the outcome treated with botulinum toxin A injections. METHODS: All subjects were studied with acoustic analysis, laryngostroboscopy and laryngeal electromyography (EMG) including motor unit potential measure (MUP), recruitment pattern analysis and evoked electromyography. All the patients with spasmodic dysphonia were received botulinum toxin A (BOTOX) injections in each affected muscles and mostly under electromyographic guidance. RESULTS: Among 22 cases of spasmodic dysphonia, 18 cases of adductor dysphonic patients have strained, strangled voice with intermittent breaks in speech as a consequence of hyperadduction and spasm of the vocal folds during phonation. Two patients had synchronous pharyngeal, lingual and velar tremor. Amplitudes of MUP of thyroarytenoid muscle (TA) were greater in patients group than in normal group (P < 0.01); The recruitment activity was increased and the amplitudes were greater than normal group (700-2500 microV) and the duration of activity of the TA during phonation was also notably greater in patients group than in normal group. Four cases of abductor dysphonic patients have a breathy, effortful hypophonic voice with abrupt termination of voicing. Amplitudes of MUP of posterior cricoarytenoid muscle (PCA) in patients group were increased up to 374 to 538 microV. The recruitment activity was increased and the amplitude was greater than normal(3000-5000 microV). In the adductor dysphonic group, patients who were treated with unilateral toxin injection had good results with 2.5 U or more. The average onset of toxin effect in all adductor dysphonic patients was at 6 hours to 2 days (1.4+/-0. 8) days (x +/- s), with a peak effect at 2 weeks and the follow-up EMG showed fibrillation potentials or electric silence in injected muscle. Duration of benefit was 8 to 24 weeks (15.2 +/- 4.9) weeks. The side-effect of toxin injection were including breathy voice or occasional dysphagia and aspiration. The patients with abductor spasms were less well controlled after PCA injections. CONCLUSIONS: Spasmodic dysphonia was regarded as a neuromuscular diseases, so its diagnosis, classification, treatment and follow-up should depend on not only clinical manifestation but also EMG. Presently, for controlling the dystonic symptoms, the most effective therapy for most of those patients is local BOTOX injections. Repeated injections are required to have a stable results.

Adult↗
PubMed2005

[Quantitative analysis of pulegone in Herba Schizonepetae].

OBJECTIVE: To establish the determination method of pulegone in Herba Schizonepetae. METHOD: HPLC method was developed for the determination of pulegone in Herba Schizonepetae. The separation was performed on C18 column with MeOH-H2O (80:20) as a mobile phase. The detection wavelength was set at 252 nm. RESULT: The quantitation of pulegone in Herba Schizonepetae varied from 0.2-0.7 mg x g(-1). The average recovery is 96.2%, RSD 0.81%. CONCLUSION: The method is simple, rapid and accurate.

Chromatography, High Pressure Liquid↗
PubMed2005

[Epidermal growth factor receptor mutation in Chinese patients with non-small cell lung cancer].

BACKGROUND & OBJECTIVE: Recent studies showed that somatic mutations in epidermal growth factor receptor (EGFR) tyrosine kinase (TK) domain are associated with sensitivity of non-small cell lung cancer(NSCLC) to TK inhibitor gefitinib. The mutations, including in-frame deletions at exon 19 and substitutions at exon 18 or exon 21, cluster around ATP-binding pocket of TK domain. The frequency of mutations are higher in Japanese patients than in American patients. This study was to analyze EGFR mutations in Chinese patients with NSCLC. METHODS: From Jun. to Oct. 2004, fresh specimens of lung cancer and corresponding normal lung tissue were collected from 52 consecutive NSCLC patients (39 men and 13 women) treated in Cancer Center of Sun Yat-sen University. All patients had not received treatment of gefitinib. DNA was extracted from the 52 specimens. Exons 19 and 21 were amplified by polymerase chain reaction (PCR), and sequenced and analyzed from both sense and antisense directions. RESULTS: Somatic mutations in TK domain of EGFR in tumors were identified from 10 of the 52 (19.2%) patients, including 7 cases of in-frame deletion in exon 19 and 3 cases of amino acid substitution in exon 21. Mutation rate was significantly higher in adenocarcinoma, adeno-squamous carcinoma, and bronchioloalveolar cancer than in squamous cell carcinoma [26.1% (6/23), 40.0% (2/5), and 50.0% (2/4) vs. 0 (0/20), P=0.025], and significantly higher in non-smokers than in smokers [41.8% (7/17) vs. 8.6% (3/35), P=0.009]. Mutation rate in women was similar to that in men [23.1% (3/13) vs. 18.0% (7/39), P=0.697]. CONCLUSION: EGFR mutation rate in Chinese NSCLC patients is similar to that in Japanese patients, and is obviously higher than that in Caucasian population.

Adenocarcinoma↗
PubMed2005

[Efficacy of gefitinib on Chinese patients with locally advanced or metastatic non-small cell lung cancer: a clinical trial].

BACKGROUND & OBJECTIVE: Gefitinib, a selective inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase, has been approved to be used in treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC) in many countries. This study, a multicenter clinical trial, was designed to evaluate the efficacy of gefitinib on Chinese patients with locally advanced or metastatic NSCLC after failure of previous chemotherapy, and explore its safety. METHODS: A total of 159 pathologically-confirmed NSCLC patients were enrolled. Gefitinib was orally administered 250 mg once daily until disease progression or the occurrence of intolerable toxicity. RESULTS: The objective response rate was 27.0%; the disease control rate was 54.1%. The median progression-free survival time was 97 days; the median overall survival time was 10.0 months; the 1-year survival rate was 44%. The most common drug-related adverse events were rash (44.0%), pruritus (15.7%), and diarrhea (10.1%), and most of them were grade 1-2 events with no need of further treatment. CONCLUSION: Gefitinib is effective and safe in treating Chinese patients with locally advanced or metastatic NSCLC after failure of previous chemotherapy.

Adult↗