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Biomedical subjects

D Shen

Publications and source records attributed to D Shen.

At least 73 records · Page 4Linked to original sources
PubMed1998

Activity of platelet in patients with high level of LDL and the effect of LDL on platelet glycoproteins.

OBJECTIVE: To investigate the activity of platelet in patients with high level of low density lipoproteins (LDL) and the effect of LDL on platelet glycoproteins (GP). METHODS: Platelet glycoproteins, whose platelet were activated or unactivated, were measured by flow cytometry. RESULTS: The amount of the platelet membrane GP II b/III a in patients was not significantly different from that of the control when platelet was unactivated (P > 0.05); when platelet was activated by adenosine diphosphate (ADP), the amount of patients' platelet GP II b/III a was increased markedly in comparison with that in the control (P < 0.01). Having been preincubated with LDL, the platelets were activated by ADP and the amounts of GP II b/III a of patients group and the control were all increased obviously as compared with those in the platelets which were not incubated with LDL (P < 0.01; P < 0.01). There was no significant difference of the amount of granule membrane protein-140 (GMP-140) between patients and the control when platelet was activated by thrombin (P > 0.05). Having been preincubated with LDL, platelet was activated by thrombin, the amounts of GMP-140 on patients' and control platelet were all increased markedly (P < 0.01, P < 0.01). CONCLUSION: The activity of platelet in patients with high level of LDL is increased significantly. LDL can increase the expression of platelet glycoproteins.

Adult↗
PubMed1998

[Production, identification and redirected cytotoxicity of CD3/CD19 bispecific monoclonal antibody].

OBJECTIVE: To prepare CD3/CD19 bispecific monoclonal antibody (BsAb) and study its biological effects. METHODS: The CD3/CD19 BsAb was prepared by using hybri-hybridoma technique. The presence of BsAb was demonstrated by double-isotype ELISA and cell conjugate assay. RESULTS: We obtained three strains of CD3/CD19 quadromas, including a stable one. 51Cr release assay showed that CD3/CD19 supernatants, CD3/CD19 purified antibody and CD3/CD19 chemical heterocongjugate greatly enhanced the cytotoxic activity of CD3 AK cells against Nalm-6 cells (P < 0.05-0.001). CONCLUSIONS: The CD3/CD19 BsAb we prepared was efficient in redirecting activated T cells against target tumor cells. This indicates that the CD3/CD19 BsAb has potential value of clinical use.

Animals↗
PubMed1998

[Application of dot immunogold filtration assay for diagnosis of Schistosomiasis japonica].

AIM: To quest for a simple and convenient assay for the diagnosis of schistosomiasis. METHODS: Three monoclonal antibodies against different epitopes of antigens of S. japonicum were used to develop a dot immunogold filtration assay for detection of schistosomal antigen-antibody reaction on the membrane during the filtration process. The results could be read with the naked eye within a few minutes. RESULTS: The sensitivity of the SEA assay was 16 ng/ml. In 69 serum samples from patients with chronic schistosomiasis, the positive rate and specificity of this assay were 60.8% and 95.2%, respectively. Dot-ELISA was used in detecting 137 serum samples from patients with chronic schistosomiasis, the positive rate and specificity were 54.7% and 94.6%, respectively. When sandwich-ELISA was used in detecting 118 serum samples from patients with chronic schistosomiasis, the positive rate and specificity were 61.9% and 95.7%, respectively. CONCLUSION: The sensitivity and specificity of DIFA were similar to those of ELISA, but DIFA required less time and no special equipment.

Enzyme-Linked Immunosorbent Assay↗
PubMed1998

Changes of plasma level of neurotensin, somatostatin, and dynorphin A in pilots under acute hypoxia.

This study examined the effect of high-altitude exposure on the plasma levels of certain peptides in the regulation of heart and blood vessels. The plasma levels of dynorphin A, neurotensin, and somatostatin were measured in 30 pilots before and after exposure to hypoxia in an altitude chamber. The results showed that plasma concentrations of the three peptides were increased significantly after exposure to hypoxia. In the test group, 18 pilots lived on a plateau (1,725 m above sea level); the other 12 pilots lived on a plain (208 m above sea level). When exposed to hypoxia, the three peptides increased significantly in the plateau group, but in the plain group, neurotensin and dynorphin A increased but somatostatin had no significant change. These results indicate that these peptides might participate in the regulation of cardiovascular activities under hypoxia.

Adult↗
PubMed1997

Redistribution of platelet membrane glycoprotein IV and release of intracellular alpha-granule thrombospondin in patients with chronic myelogenous leukemia.

The redistribution of platelet membrane glycoprotein IV (GPIV) and the release of intracellular alpha-granule thrombospondin (TSP) were examined and the inhibition of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) in patients with chronic myelogenous leukemia (CML) was observed and quantitation of beta-TG and PF4 in sera was conducted. GPIV in inactive platelet from CML was 36080 +/- 17010 molecules/platelet as compared with 13190 +/- 4810 from the controls (P < 0.01). No abnormality was found in the distribution of platelet membrane GPIb and GPIIb/IIIa (P > 0.05). The GPIV redistribution on active platelet membrane induced thrombin (IU/ml) from CML and healthy donors was 44320 +/- 32310 and 22800 +/- 12700 molecules/platelet respectively (P < 0.01). The difference in the release of intracellular alpha-granule TSP between CML and the control group was not found (P > 0.05). There was no direct correlation between GPIV expression and TSP binding after platelet activation. The high levels of beta-TG and PF4 in sera inhibited release of intracellular alpha-granule TSP in vitro. These results indicate that the abnormality of platelet membrane GPIV is a common marker in CML, therefore the specific increase of platelet GPIV in patients with CML may be a useful tool for the diagnosis and monitoring of the platelet dysfunction. The release of internal TSP pools is hindered by either beta-TG or PF4 in sera.

CD36 Antigens↗
PubMed1997

First trial of home ECG and blood pressure telemonitoring system in Macau.

OBJECTIVE: To determine the feasibility of home monitoring of patients with cardiac disease or hypertension. METHODS: An improved home electrocardiographic and blood pressure telemonitoring system linked to a central workstation was tested in 10 patients in Macau for 3 months. RESULTS: The total number of connections was 1377. Of the automatic alarm connections, 32.5% were false positive, with the percentage of false positives ranging from 7.6 to 54.6 for different patients. Both patients and physicians found the system easy to use. CONCLUSIONS: Further investigation is required to match the number of patients with the system capacity. A more robust dysrhythmia detection algorithm is needed to reduce the number of false alarms. Nevertheless, the results were sufficiently good that the trial is being expanded.

Blood Pressure Determination↗
PubMed1997

A home electrocardiography and blood pressure telemonitoring system.

A home electrocardiography (ECG) and blood pressure telemonitoring system for cardiac patients was installed in the Macau region. The monitoring centre was established in the emergency unit at the Government Hospital of Macau. The first users were 10 cardiovascular patients selected by a physician. The average age of these users was 61 years (range 30-78). The results of a three-month trial showed that the system was easy to operate and technically reliable. It was found to be helpful for cardiac patients. The most significant problem during the trial was electrical noise from the ECG electrodes.

Adult↗
PubMed1997

[Inclusion body myositis: clinical and myopathological features].

Inclusion body myositis has been recognized as a major form of idiopathic inflammatory myopathy. An old male patient with insidious onset and slowly progressive muscular weakness and artrophy has been reported in this article. The duration of symptom before biopsy was 23 years. The first symptom was dysphagia, and muscular weakness developed seven years later. Muscular atrophy was predominant symmetrically and proximally, particularly the quadriceps femoris muscles. Cervical and abdominal muscles were also affected. Myalgia was absent. Electromyogrophy showed myopathic alterations. Erythrocyte sedimentation rate, creatine kinase, immunoglobulins G increased slightly or moderately. Rheumatoid factor was positive, and he had been diagnosed as having rheumatoid arthritis for 23 years. Inclusion body myositis was ultimately diagnosed based on the muscle biopsy which showed mononuclear cell invasion of nonnecrotic muscle fibers, the characteristic rimmed vacuoles in cryostat sections and cytoplasmic inclusion bodies consisted of plenty of tubulofilaments by electron microscope.

Aged↗
PubMed1997

[Clinical evaluation of serum transforming growth factor beta 1 assay in the diagnosis of primary hepatic carcinoma].

Serum transforming growth factor beta 1 (TGF beta 1) concentration was determined in 47 patients with primary hepatic carcinoma (PHC) and 77 patients with various liver diseases and gastrointestinal tumors by means of enzyme-linked immunosorbent assay system. The result revealed that serum TGF beta 1 level of PHC patients were significantly higher (257.6 +/- 126.0 micrograms/L) than those in normal subjects (81.5 +/- 43.5 micrograms/L), in patients with hepatitis (152.4 +/- 98.4 micrograms/L), cirrhosis (191.8 +/- 96.3 micrograms/L), hepatic benign tumor (91.9 +/- 37.9 micrograms/L), metastatic liver cancer (146.4 +/- 73.7 micrograms/L) and gastrointestinal tumor (128.7 +/- 56.4 micrograms/L) (P < 0.01 or 0.05). Serum TGF beta 1 level was elevated in 34 of 47 (72.3%) PHC patients, including 5 of 7 (91.4%) small (< 5 cm) PHC patients. The sensitivity and specificity of diagnosis of TGF beta 1 in PHC were 72.3% and 77.9%, respectively. The diagnostic positivity was 78.5% in AFP-negative PHC patients. The combined assay of serum TGF beta 1 and AFP could further raise the detection rate of PHC up to 93.6%. Above results suggest that serum TGF beta 1 might be a candidate for a novel tumor marker for diagnosis and monitoring of PHC.

Biomarkers, Tumor↗
PubMed1997

[Down-regulation effect of HIM82 on respiratory burst of neutrophil].

OBJECTIVE: The early control of respiratory burst of Neutrophil (PMN) was studied by using McAb HIM82. METHODS: PMNs were isolated from healthy volunteers. Superoxide anion, Hydrogen peroxide were measured in the presence of HIM82 FMLP. Sustance P and the NEP activities was measured in the presence of HIM82 alone. RESULTS: The amount of O2.- and H2O2 produced in experimental group (by combining with HIM82) are (44.00 +/- 8.9)% (n = 8, P < 0.01) and (65.16 +/- 15.41)% (n = 8, P < 0.01) of control group respectively. The activity of NEP inactivated by PMA (without HIM82) is (43.29 +/- 9.41)% (n = 8, P < 0.05) and the activity is (66.48 +/- 15.53)% (n = 8, P < 0.05) in PMA-inactivated group with HIM82. CONCLUSIONS: The result mentioned above showed that the HIM82 monoclonal antibody exerts obvious down regulation on respiration burst induced by PMA and antagniation on inactivity of NEP. We under stand that this McAb has important regulation effect on function of PMN, it shows that the specific combination with corresponding antigen on membrane is essential for function of PMN especially for mechanism of respiratory burst of activated PMN.

Antibodies, Monoclonal↗
PubMed1997

[Cloning and sequencing of cDNA of E2/NS1 gene of hepatitis C virus].

Hepatitis C virus (HCV) RNA extracted from serum of a patient infected with HCV in Beijing was converted to cDNA by reverse transcription. HCV E2/NS1 gene (approximately 930 bp) was amplified by nested polymerase chain reaction and was inserted into pGEM-T plasmid vector. The 431 bp nucleotide sequence at 5' terminus of this gene was determined by dideoxy-mediated chain termination method. The result of comparison of this sequence and sequences of another 9 HCV isolates suggested that the isolate we obtained was highly homologous to HCV genotype II. There are two hypervariable regions (HVR) at the N terminus of envelope protein encoded by HCV E2/NS1 gene. Several relatively conserved amino acid residues and areas located in and out of HVR were also observed. They are concerned in maintenance of spatial conformation of HCV envelope protein, but their immune function remains to be further studied.

Amino Acid Sequence↗
PubMed1997

[Immunophenotyping study on the blood cells of the patients with paroxysmal nocturnal hemoglobinuria].

OBJECTIVE: To detect the expression of glycosyl-phosphatidyl-inositol (GPI) anchored protein on the blood cell membrane and its implication in the diagnosis of paroxysmal nocturnal hemoglobinuria (PNH). METHODS: The GPI anchored protein was detected by indirect immunofluorescence method with a panel of monoclonal antibodies (CD55, CD59, CD16, CD58, HIR2, CD15, CD2) in 22 PNH patients. RESULTS: The abnormal granulocytes and erythrocytes with deficient GPI anchored proteins were identified in all PNH patients whether the routine hemolysis tests for PNH, including Ham test and mCLST, were positive or negative. However, lymphocytes with PNH-defect were found in only 14 patients. CONCLUSION: GPI anchored protein assay provided sensitive and specific method for the diagnosis of PNH.

Adult↗
PubMed1997

[Expression of CD45RA and CD45RO antigens and its implication in leukemias].

OBJECTIVE: To investigate the expression of CD45RA and CD45RO antigens in leukemias and its implication in the diagnosis and differential diagnosis of leukemias. METHODS: The expression of CD45 RA and CD45RO antigens and other markers on the surface of bone marrow or peripheral blood cells was investigated by indirect immunofluorescence in 104 cases of leukemias. Of them, 33 cases were ALL (23 of B-lineage ALL and 10 of T-ALL), 62 AML, and 9 B-CLL. RESULTS: Four patterns, CD45RA+/RO-, CD45 RA-/RO+, CD45RA+/RO+ and CD45RA-/RO-, were revealed. 87% of B-lineage ALL displayed CD45 RA+/RO-, 70% of T-ALL CD45RA-/RO+, and 78% of B-CLL CD45RA+/RO+, The frequency of the four patterns was 56% for CD45RA+/RO-, 18% for CD45RA-/RO+, 16% for CD45RA+/RO+ and 10% for CD45RA-/RO-, respectively in AML, and had no correlation with AML subtypes. CONCLUSION: CD45 isoform patterns could be served as supplementary tools for the differential diagnosis of B-lineage ALL, T-ALL and B-CLL.

Adolescent↗
PubMed1997

[Determination of organic acids and inorganic anions by gradient ion chromatography].

The chromatographic conditions for separation and detection of organic acids and inorganic anions by gradient ion chromatography with suppressed conductivity detection were studied. The optimized gradient programs were established. Ion chromatography were performed with a DX-100 chromatograph (DIONEX). The separation column is IonPac-AS11. Compared with NaHCO3/Na2CO3 and Na2B4O7, NaOH was the optimal eluent. The effect of organic modifier was also studied. Among methanol, 2-propanol and acetonitrile, methanol can make ion pairs such as malate and succinate, malonate and tartrate gaining baseline resolution. By using ion exchange separation, Cl-, NO3-, malate, succinate, malonate, tartrate, SO4(2-), oxalate were eluted between 5 mmol/L NaOH-16% CH3OH and 10 mmol/L NaOH-16% CH3OH in 25 min. A mobile phase composed of 30 mmol/L NaOH, 50% CH3OH and D.I. water was chosen to elute two groups of organic acids and inorganic anions: (1) quinate, formate, Cl-, malate, malonate, oxalate, citrate, isocitrate, aconitate; (2) lactate, Cl-, SO4(2-), tartrate, PO4(3-), citrate, isocitrate, aconitate. The detection limits (S/N = 3) were 0.1625 (quinate), 0.0691 (formate), 0.0115 (Cl-), 0.0886 (malate), 0.0591 (malonate), 0.0263 (oxalate), 0.1147 (citrate), 0.2017 (isocitrate), 0.3656 (cis-aconitate), 0.1045 (trans-aconitate), 0.1950 (lactate), 0.0729 (tartrate), 0.0224 (SO4(2-)) and 0.0692 (PO4(3-)) mg/L. The relative standard deviations were lower than 11.9% (n = 7) and the correlation coefficients ranged from 0.9212 for Cl- to 0.9999 for formate. The method was applied to determine the organic acids and inorganic anions of beverages and citric acids fermenting-medium. The results were satisfactory.

Anions↗
PubMed1997

[Clinical observation on effect of xiaoyu zhixue tablet on 104 patients with idiopathic multifocal bleeding and platelet aggregation defect].

OBJECTIVE: To explore the effect and pharmacological mechanism of Xiaoyu Zhixue Tablet (XZT). METHODS: The XZT mainly composed of Chinese medicinal herbs to replenishing Qi and removing stasis was used to treat patients with idiopathic multifocal bleeding and platelet aggregation defect. Patients were divided into 2 groups. The TCM group (104 cases) treated with XZT, and the control group (84 cases) treated with vitamins C, K and P, adrenosin and (or) artificial menstruation, for at least 4 months. RESULTS: The hemostatic effective rate was 92.3% in TCM group and 27.4% in control group (P < 0.005), the recovery rate of platelet aggregation after 6 months therapy was 69.2% and only 1.8% respectively. The difference between two groups was very significant (P < 0.005). CONCLUSION: XZT could regulate the physiological functions of blood-vessel and platelet to realize the hemostatic action and platelet aggregation.

Adolescent↗
PubMed1996

Cross-resistance, cisplatin accumulation, and platinum-DNA adduct formation and removal in cisplatin-sensitive and -resistant human hepatoma cell lines.

The BEL7404 human hepatoma cell line was selected in vitro for primary cisplatin resistance. A panel of four cisplatin-resistant sublines were generated which exhibited resistance to cisplatin (up to 34-fold) but were not cross-resistant to adriamycin, taxol, etoposide, or mitomycin C. Further characterization of this panel of cell lines revealed that increased cisplatin resistance was associated with decreased cisplatin accumulation in the selected sublines (up to 14-fold) relative to the parental BEL7404 cell line. A significant reduction in platinum-DNA adduct formation (9-fold) and ribosomal RNA gene-specific interstrand crosslink formation (12-fold) were also observed in the 7404-CP20 cell line. No differences in the rate of platinum efflux from the BEL7404 and 7404-CP20 cell lines were detected following a 4-h loading period, and total platinum-DNA adduct and gene-specific interstrand crosslink removal rates were similar in both cell lines. There were approximately 3-fold more total platinum-DNA adducts present in the BEL7404 cells relative to the 7404-CP20 cells at equitoxic concentrations of cisplatin, suggesting that DNA damage tolerance also contributes to the cisplatin resistance phenotype. Overall, these results indicate that decreased cisplatin accumulation is the major cisplatin resistance mechanism present in the in vitro-selected cell lines. This model system of acquired cisplatin resistance may be valuable in determining the molecular basis for decreased cisplatin uptake and be useful for the study of potential resistance modulators.

Carcinoma, Hepatocellular↗