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Biomedical subjects

Y Wu

Publications and source records attributed to Y Wu.

At least 793 records · Page 44Linked to original sources
PubMed1997

[Immunohistochemical study of p53, c-erbB-2 and nm23 proteins in human gastric cancer].

OBJECTIVE: To evaluate p53, c-erbB-2 and nm23 oncoproteins in diagnosis of gastric cancer. METHODS: The expression of p53, c-erbB-2 and nm23 oncoproteins was detected immunohistochemically in 141 surgically resected specimens and 93 endoscopic biopsy specimens of gastric cancer. RESULTS: The positive rate of p53, c-erbB-2 and nm23 immunoreactivity was 45.8-56.3%, 18.3-31.2% and 72.9%-81.3% respectively. No immunoreactivity was observed in the tumor-adjacent normal mucosa and non-tumor biopsy specimens. The presence of c-erbB-2 was correlated with the size of tumor, grade of tumor differentiation and Lanren classification. Patients with c-erbB-2 positive tumor had lower 5-year survival rate. The expression of nm23 was negatively correlated with the depth of invasion, and lymphnode metastasis. The positive rates of p53, c-erbB-2 and nm23 had no statistical difference between biopsy and resected specimens. CONCLUSION: Determination of p53, c-erbB-2 and nm23 oncoproteins immunohistochemically might be useful in the diagnosis and differential diagnosis, clinical staging, and predicting prognosis of gastric cancer.

Adenocarcinoma↗
PubMed1997

[Effects of total flavones of fructus Hippophae (TFH) on cardiac function and hemodynamics of anesthetized open-chest dogs with acute heart failure].

This study was carried out employing the model of dog with acute heart failure induced by phenobarbital natricum. It was shown that i.v. TFH 4.8 and 9.7 mg/kg could significantly increase CO, CI, + LVdP/dtmax and LVSP; shorten R-dP/dtmax in 9.7 mg/kg; raise - LVdP/dtmax, reduce LVEDP and T value; decrease MVO2I and TPVR; MAP and HR were not changed significantly. The results suggest that i.v. TFH can strengthen cardiac pump function and myocardial contractility in canine with heart failure; significantly improve myocardial diastolic function and hemodynamic performance; markedly decrease myocardia-used oxygen index and total peripheral vessel resistance, thus proving that TFH is good for heart failure.

Animals↗
PubMed1997

[Model-based study of time-dependent coronary blood flow distribution in left ventricular wall and its dependences on coronary pressure driving force].

The proposed model is of use for understanding the mechanism of intramyocardial circulation. There are three classical myocardial vascular nets in the model; each net has four vessel-size compartments which are characterized by time-dependent nonlinear resistance and compliance. The experimentally measured timed-varying perfusion and left ventricular pressure sources are used as driving inputs for the circulation. The phasic coronary blood flow characteristics predicted by the model exhibit waveform patterns that correlate qualitatively with the generally accepted results. In addition, more work is made about the myocardial infusion which is essentially controlled by the coronary pressure driving force. The results make it clear that the Intra-aortic balloon pumping and External counterpulsation are conducive to the balance between supply and demand of coronary blood flow.

Coronary Circulation↗
PubMed1997

[Effect of electric field on erythrocyte sedimentation rate. VI--dependence of electric field pattern].

An automatic analyzer of RBC rheological parameters and a microscopic morphological observation technique were employed to investigate the effect of three electric field patterns on erythrocyte sedimentation and aggregation in a physiological saline solution and in autologous plasma, respectively. Experimental results indicate that in a physiological saline solution: 1) Erythrocytes present a lightly aggregation and settle faster by an alternative current electric field; 2) There exists no erythrocyte aggregation by a direct current electric field of constant current and the enhancement of erythrocyte sedimentation is caused only by the action of electric force; 3) Time courses of erythrocyte sedimentation fit well with an exponential type curve by a direct current electric field of constant voltage, and this exponential type sedimentation curve is not caused by erythrocyte aggregation but caused by the decrease of circuit current with time duration. Also shown by experimental results is that the above three electric field patterns all affect the erythrocyte sedimentation in antologous plasma in different contents, which predicts some change in erythrocyte aggregation behavior in autologous plasma by an external electric field.

Blood Sedimentation↗
PubMed1997

[The developement of a new torque experiment device for biomaterials].

This paper introduces a biomaterial torque experiment apparatus which consists of AST486 computer, photodiode array, code device interface circuit, and magnetoelectric motional coil structure. According to experimental conditions, the computer sends out signal to the coil which under the magnetic field is activated to produce a series of desired torque and bring the sample to deflect. Angular displacement is measured by photodiode array and code device system. The whole system has good dynamics and high precision and could finish a series of torque experiment for biomaterials, and AST486 computer can automatically conduct signals analyzing and data processing.

Biocompatible Materials↗
PubMed1997

[Experimental study on erythrocyte of obstructive jaundice patient: its changes of membrane protein and mechanical properties].

The component of the erythrocyte membrane protein under three states obstruction, after surgical relief of obstruction, and normal) were analyzed qualitatively by using SDS-PAGE and the method of thin scanning. The result revealed that the membrane protein band 4.2 was absent under the state of obstruction and it recovered after surgical relief of obstruction. Then the mechanical properties of the above three cases of erythrocytes were tested by the micropipette aspiration system and the data were analyzed by Voigt model. The result showed that the elastic modulus and the coefficient of viscosity of the erythrocytes under the state of obstruction were greater than those of the normal; thus the deformability decreased, but "overcorrection" appeared after surgical relief of obstruction. The possible relations between the mechanical properties and the change of membrane protein were discussed.

Adult↗
PubMed1997

[Materials using in the prevention of scar formation after laminectomy].

The recurrent syndrome after laminectomy is related to the scar formation overlying epidural. To solve this catastrophic problem means to prevent the fibrosis. In the present review a variety of materials used in the inhibition or prevention of that syndrome are introduced, and their effects are reviewed and discussed. Some characteristics of the materials for prevention are summarized, and in our experiments the material point of view is rational.

Animals↗
PubMed1997

[Studies on the analysis of hydrocodone and its metabolite in human urine by GC/MS].

The method for the analysis of hydrocodone and its metabolite in urine by GC/MSD is reported. The urine was hydrolysed with HCl and extracted with diethyl ether/isopropanol. The gas chromatography/mass spectrometric properties of trimethylsilyl ether of hydrocodone, first reacted with methoxyamine to protect the carbonyl group, were studied. This method is sensitive and rapid for the determination of hydrocodone, codeine and dihydrocodeine.

Analgesics, Opioid↗
PubMed1997

[A study on central and peripheral nerve transmitter mechanism of motion sickness].

Model of motion sickness (MS) was induced in rats by accelerating and decelerating vertical rotation for 60 min. The contents of Ach, NA, A and 5-HT and the activity of AchE in brain and blood of rats were examined after 60 min of rotation. The results showed: NA contents and AchE activity decreased significantly while A and 5-HT increased in rat's brain. Levels of Ach, NA and A in blood were increased. The results suggested that MS may be related to the imbalance of transmitters in the central nervous system resulting in the reduction of central arousal, and the imbalance between sympathetic and parasympathetic nerves.

Acetylcholine↗
PubMed1997

[Study on the clinical and biological characteristics of 20 cases of chronic lymphoid leukemias].

OBJECTIVE: To further define the chronic lymphoid leukemia (CLL). METHODS: Tweenty cases of CLL classified after the FAB proposals (1989) were retrospectively analyzed. RESULTS: Based on the clinical features, cell/tissue morphology, immunophenotype, IgH and TCR gamma gene rearrangement serum or urine immunoglobulin levels, 16 cases of B-lymphoid leukemia (12 of CLL, 1 of PLL, 2 of leukemia/lymphoma, and 1 of WM) as well as 4 cases of T-lymphoid leukemia (2 of leukemia/lymphoma, 1 of T-LGLL, and 1 of NK-LGLL) were identified. The diagnostic criteria,cell morphology,biological characteristics and prognosis for CLL were discussed. CONCLUSION: T-leukemia/lymphoma should be incorporated in the classification of CLL.

Chronic Disease↗
PubMed1997

[Arginine-glutamine replacement at residue 57 of NADH-cytochrome b5 reductase in Chinese hereditary methemoglobinemia].

OBJECTIVE: To elucidate the molecular mechanism of NADH cytochrome b5 reductase (Cytb5R) deficiency in hereditary methemoglobinemia. METHODS: Cytb5R cDNA was cloned from white blood cells from patient with hereditary methemoglobinemia by RT-PCR method, and the genomic DNA from 3 pedigrees with hereditary methemoglobinemia were analyzed by restriction enzyme analysis. RESULTS: On sequencing the cDNA, two missense mutation were found. One is CGG-->CAG at codon 57 of exon 3, caused Arg-Gln replacement. The other is GAG-->GGG at codon 222 of exon 8. The former mutation abolishes the Msp I recognition site which was confirmed in two of three hereditary methemoglobinemia family. The latter mutation generates a recognition site for Bsi Y I. Amplification of exon 8 by PCR followed by digestion with Bsi Y I revealed no mutation in all patients from the three families. CONCLUSION: Arg57-Gln replacement is responsible for Cytb5R deficiency in the two Chinese pedigrees.

Adult↗
PubMed1997

[The preliminary investigation on proliferative and survival capabilities of normal and abnormal mononuclear cells in bone marrow of patients with paroxysmal nocturnal hemoglobinuria].

OBJECTIVE: To unfold the proliferation and survival behavior of normal and abnormal early hematopoietic cells in paroxysmal nocturnal hemoglobinuria(PNH). METHODS: The bone marrow mononuclear cells (BMMNC) from 6 patients with PNH were separated into two subpopulations using CD59 monoclonal antibody combined with goat-anti-mouse IgG immunomagnetic beads, and then cultured in vitro. RESULTS: The BMMNCs from normal control had better proliferation capacity and stronger potential of suvival than both CD59(+) and CD59(-) BMMNCs from PNH patients. The CD59(+) BMMNCs from PNH patients, which should be expected "normal" in view of the CD59 expression, were surprisingly found to have less capabilities to form CFU-GM and BFU-E in semisolid cultures and less abilities of expansion and survival in liquid cultures than their CD59(-) counterparts. The CD59 expression of CD59(+) BMMNC in PNH patients diminished to some extent after a period of liquid culture while the normal control remained unchanged indicating that some of CD59 antigen on the cells were gradually lost during cultivation. CONCLUSION: In all cases of PNH studied, CD59(-) BMMNCs dominated hemopoiesis, and CD59(+) BMMNCs seems to have less potential to proliferate. The emergence of abnormal CD59(-) cells could not only result from PIG-A gene mutation but might also arise as the consequence of loss of GPI-anchored protein during the course of hematopoietic development and differentiation.

Animals↗
PubMed1997

[Effects of antisense oligodeoxynucleotides targeting multidrug resistance gene on resistant cell line K562/ AO2].

OBJECTIVE: To investigate the reversal effect of antisense oligodeoxynucleotide on human multidrug-resistant leukemic cell line K562/AO2. METHODS: Antisense oligodeoxynucleotides (AOD) targeting-6 approximately 9 sites of exon 2 in human multidrug resistance gene(mdr-1), one of which is sequence-strict-complied and linked with polyethyleneglycol (PEG) at 5' end (AP, 15 mer), the other lacks nucleotide complied site-1 (AP', 14mer), were synthesized. AP, AP' and verapamil were simultaneously added to human mdr-1-mRNA positive leukemia cell line K562/AO2 and, mdr-1-mRNA and p170 were detected. AS' and AP'were labelled by FITC and designated as ASF' and APF', respectively. In addition, the intracellular concentration of them was detected by FACS. RESULTS: AP' significantly enhanced the sensitivity of K562/AO2 to DOX, down-regulated the expression of mdr-1 and MRP-mRNA and p170, elevated the intracellular concentration of the two AOD, while AP had no effect. The uptake of APF' was significantly higher than that of ASF' in K562/AO2, and the fluorescence was observed in the plasma and nuclear of K562/AO2 cells. CONCLUSION: (AOD targeting mdr-1 promoted the drug sensitivity of drug-resistant tumor cells. 2 AOD had no cytotoxicity to tumor cells. 5 Low molecule PEG enhanced significantly the uptake of AOD by tumor cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

[Study on the separation and determination of phthalates in plants].

A convenient and efficient method for analysis of phthalate esters (PEs) in plants was developed. PEs in plants were extracted with dichloromethane by ultrasonication, separated by chromatography with a column chromatography packed with 10-40microm sillica and then determined by HPLC on a 250mm x 4.6mm i.d. ODS column using MeOH/H2O (88:12) as mobile phase and UV detection at 228nm. The minimum detectable limits for diethyl phthalate (DEP) and diethylhexyl phthalate (DEHP) were 47pg and 85pg respectively. The overall recoveries of PEs were found to be 85%-101%. The method has been satisfactorily applied to the determination of plant samples.

Chromatography, High Pressure Liquid↗
PubMed1997

[Determination of decomposition products of di-t-butyl peroxide by gas chromatography].

In this work we found that there were five decomposition products of di-t-butyl peroxide at 320 degrees C by GC-MS. The peak area of acetone as a chief product in the thermal decomposition was related to di-t-butyl peroxide concentration in a linear manner. The range was from 22.91 to 114.93 microg (r=0.9997, n=4). By use of the calibration, we can possibly determine the content of the peroxide rapidly. The present method is more suitable for the determination of peroxide that is liable to decompose and difficult to be vaporized.

Chromatography, Gas↗
PubMed1997

[Three-dimensional microanalysis of arsenic impurity in silicon].

The three-dimensional distribution of arsenic impurity concentration on the silicon wafer surface is determinaed by means of synchrotron radiation X-ray microfluorescence (SRXRF) and total reflection X-ray fluorescence (TXRF) anslysis. The result of depth profile of As is checked with secondary ion mass spectrometry (SIMS) and the agreement is reasonably good.

English Abstract↗