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Biomedical subjects

X Yang

Publications and source records attributed to X Yang.

At least 271 records · Page 15Linked to original sources
PubMed2001

[The effect of ETA receptor antagonist WS009A on the pathogenesis of hypoxic pulmonary hypertension in rats].

OBJECTIVE: To investigate the effect of ETA receptor antagonist, WS009A, on the pathogenesis of hypoxic pulmonary hypertension in rats. METHODS: In the course of chronic hypoxia, rats were treated with WS009A (10 mg/kg) by a siliastic catheter inserted in the left external jugular vein. RESULTS: The measured values of mean pulmonary arterial pressure (mPAP) were 2.7 +/- 0.33, 3.97 +/- 0.47 [symbol: see text] 2.39 +/- 0.27 kPa in the control, the hypoxic and the WS009A treated groups, respectively. The percentages of vascular wall area/total vascular area (MA%) were 0.26 +/- 0.03, 0.52 +/- 0.04, 0.32 +/- 0.07, respectively. The percentages of vascular wall thickness/vascular external diameter(MT%) were 0.14 +/- 0.02, 0.31 +/- 0.03, 0.18 +/- 0.05, respectively. The ratios of right ventricular wall to left ventricle plus septum[RV/(LV + S)] were 0.24 +/- 0.02, 0.35 +/- 0.03, 0.26 +/- 0.03, respectively. The variance analysis revealed there were decreases in mPAP and the ratio of RV/(LV + S) in WS009A group (P < 0.01, compared with those in hypoxic group). There were no haemodynamic and right ventricular hypertrophy differences between WS009A group and control group. The MT% and MA% in WS009A groups were higher than those in controls, but there were significantly decreased MT% and MA% in WS009A group as compared with those in hypoxic group (P < 0.01). CONCLUSION: The ETA receptor antagonist, WS009A, attenuates the pulmonary vascular wall remodelling and the pulmonary hypertension induced by chronic hypoxia.

Animals↗
PubMed2001

[The measurement of 153Sm-EDTMP bone uptake rate and its relationship with therapeutic effect].

OBJECTIVE: To evaluate the measurement of 153Sm-EDTMP Bone uptake rate with whole-body scintigraphy and analyze the relationship between bone uptake rate and therapeutic effect. METHODS: 66 patients with bony metastases were examined with whole-body scintigraphy 10 minutes and 6 hours after the administration of 153Sm-EDTMP, and then bone uptake rate was calculated. RESULTS: The bone uptake rate in 66 patients ranged from 31.9% to 86.6%, (mean 56.0%). The patients with higher bone uptake rate had better overall therapeutic effect. According to the bone uptake rate calculated by whole-body scintigraphy, the therapy activity administered within the limit of bone marrow absorbed dose of 1400 mGy in these patients was 1.40-2.27GBq (mean 1.90 GBq). CONCLUSION: The present authors have developed a whole-body scintigraphic technique which is simple and reliable in calculating prospectively a safe and effective dose of 153Sm-EDTMP for palliating the patient's painful bone metastases without myelotoxicity.

Adult↗
PubMed2001

[Application of video laryngoscope in diagnosis and treatment of laryngeal diseases].

OBJECTIVE: To investigate the value of video laryngoscope in diagnosis of laryngeal diseases. To study the effect of video laryngoscope in treatment of laryngeal diseases. METHOD: Pentax VNL-1530T and Olympus BF-240T video laryngoscope were used in diagnosis of 3628 cases of laryngeal diseases and in treatment of 1221 cases of laryngeal diseases. RESULT: 3628 cases were examined by video laryngoscope, and correct diagnosis was made. 768 cases of vocal cord polyp and 249 cases of vocal cord node were excised, 113 cases of foreign bodies in hypopharynx or larynx were removed. 91 cases of other laryngeal diseases were treated under video laryngoscope. CONCLUSION: Video laryngoscope is a new excellent instrument in diagnosis and treatment of laryngeal disease.

Adolescent↗
PubMed2001

[Research on the immunological cause of auricular pseudocyst].

OBJECTIVE: To elucidate the relationship between the auricular pseudocyst and the immunological function of patients. METHOD: The cyst fluid and blood sample had been detected for contents of IgG, IgA, IgM and complement C3 by radial immunodiffusion, immunocomplex (IC) contents by polyethylene glycol turbidimetry in 55 cases, anti-nuclear antibody (ANA) by immuno-fluorescent technique in 23 cases, extractable nuclear antibody (ENA) by immunotransfer technique in 24 cases. The frozen sections of cyst wall tissue of 24 cases had been detected for immunocomplex by immunoenzyme histochemistric method. The reactions were observed separately between the auricle tissue of healthy white rat, human embryo and cyst fluid, serum of patient and normal serum. RESULT: Contents of IgG, IgA, IgM and C3 in the cyst fluid were lower than the serum significantly (P < 0.01). No IC, ANA and ENA could been found both in serum and cyst fluid, but reactive immunocomplex was discovered on the auricle cartilagous tissue of patient, immunocomplex also be observed on human embryo aurical tissue when it reacted with cyst fluid, but complex hadn't be found when the auricle tissue of white rat and human embryo reacted with serum of patient and normal people. CONCLUSION: The reason of auricular pseudocyst may be related with the local autoimmune status of patient.

Adult↗
PubMed2001

[Characters of uncoupling protein and its relation with obesity].

Uncoupling proteins(UCP) are carrier proteins in mitochondria. In eukaryotic cells, ATP is generated by oxidative phosphorylation, an energetic coupling at mitochondria level. The oxidative reactions occurring in the respiratory chain generate an electrochemical proton gradient at both sides of the inner membrane of mitochondria. This gradient is used by the ATP synthase to phosphorylate ADP into ATP. The coupling of cell respiration with ADP phosphorylation is only partial in brown adipose tissue (BAT) mitochondria, where UCP causes a reentry of protons into the matrix and abolishes the electrochemical proton gradient. The liberated energy is then dissipated as heat and the synthesis of ATP is reduced. Recently, the cloning of new UCPs expressed in other tissues revealed the importance of this kind of regulation of respiratory control in metabolism and energy expenditure. The newly characterized UCPs are potential target drugs for obesity treatment, which could be favor of energy expenditure and diminish the metabolic efficiency.

Energy Metabolism↗
PubMed2001

[Determination of total, soluble and insoluble dietary fiber in foods by enzymatic-gravimetric method].

For studying the contents of dietary fiber in general foods and functional foods, a enzymatic-gravimetric method recommended by AOAC was established in our laboratory. The method for the determination of total, soluble and insoluble dietary fiber in foods and functional foods could be used for many other kind of foods. The relative standard deviations (RSD) of reproducibility between-run and within-run were 2.04%-7.85%, 3.42%-55.23% respectively. The repeatability of the methods was good, and the methods are suitable for many foods.

Dietary Fiber↗
PubMed2001

[Effects of pressure induced retinal ischemia on ERG in rabbit].

OBJECTIVE: To observe the effects of pressure induced retinal ischemia on electroretinogram(ERG) in rabbit. METHODS: Retinal ischemia was induced in rabbits by increasing intraocular pressure at 30 mmHg, 60 mmHg, 90 mmHg, 120 mmHg for 45 minutes, and retinal function was monitored by eletroretinography. RESULTS: There was no difference on ERG before or after the experiment both in 30 mmHg group and control one. In 60 mmHg pressure induced ischemia eyes, the amplitudes of the b-wave and OPs wave reduced significantly. Four hours after reperfusion, they were totally recovered. After an ischemic insult of 90 mmHg or 120 mmHg for 45 minutes, there was no response of ERG. Four hours later, the amplitudes of the b-wave and OPs wave were 66.912 +/- 20.157 and 16.423 +/- 3.965 the former, 38.852 +/- 23.438 and 8.610 +/- 12.090 the latter, respectively. CONCLUSION: These results suggest that higher intraocular pressure causes more severe retina ischemic damage, and less recovery ability.

Animals↗
PubMed2001

[Effect of ligustrazine peritoneal dialysate on CD40 expression of rat peritoneal mesothellial cells].

OBJECTIVE: To explore the effect of Ligustrazine (LGZ) affecting the expression of CD40 on mesothelial cells (MC). METHODS: Rat's peritoneal MC isolated from peritoneal cavity were cultured and maintained under the defined conditions in vitro. They were cultured with 4.25% peritoneal dialysis solution (PDS), 4.25% PDS added LGZ (40 mg/L), 4.25% PDS added IFN-gamma (100 u/ml) and 4.25% PDS added IFN-gamma and LGZ for 30 min, the DMEM/F12 cultural medium was taken as control. The expression of CD40 on MC was detected by reverse transcript polymerase chain reaction (RT-PCR) and flow cytometry analysis. RESULTS: MC cultured in vitro expressed CD40 markedly, the expression of CD40 mRNA and its protein was markedly up-regulated following stimulation with 4.25% PDS or IFN-gamma and 4.25% PDS. LGZ (40 mg/L) could reduce the expression of CD40 mRNA and its protein significantly as it was added in 4.25% PDS and 4.25% PDS with IFN-gamma. CONCLUSION: The PDS stimulates the expression of CD40 on MC. LGZ has the function of down-regulating the expression of CD40 on MC. During long-term continuous ambulatory peritoneal dialysis, it might be helpful to alleviate chronic inflammatory reaction by adding LGZ into standard PDS, therefore prevent or retard the occurence and development of peritoneal fibrosis.

Animals↗
PubMed2001

[Intravitreally injectable poly (D, L-Lactide) microspheres containing dexamethasone acetate for sustained release].

AIM: To prepare and evaluate dexamethasone acetate-loaded poly (d, l-lactide) microspheres for sustained release in vitro and their therapeutic effect on proliferative vitreoretinopathy in vivo. METHODS: The microspheres were prepared by a solvent evaporation/extraction technique. Properties such as geometric mean diameter, span, drug loading, rate of entrapment and release characteristics were evaluated. Differential scanning calorimetry and X-ray powder diffractometry were used to identify the physical phase of dexamethasone acetate in poly (d, l-lactide) matrix, and safety in vivo was examined. Effect of drug-loaded microspheres on suppression of experimental proliferative vitreoretinopathy was studied in albino rabbit eyes after an intravitreal injection of macrophages. RESULTS: The geometric mean diameter and span of the microspheres were 62.9 microns and 0.92, respectively. Drug loading and rate of entrapment of dexamethasone acetate in microspheres were 17.5% and 86.5%, respectively. Differential scanning calorimetry and X-ray powder diffractometry showed that dexamethasone acetate dispersed uniformly as molecules in poly (d, l-lactide) matrix. Ninety percent of the dexamethasone acetate was released in vitro from dexamethasone acetate after 48 days, while the same amount released from microspheres took 90 days. Storage under 4 degrees C in refrigerator or 25 degrees C in a dessicator at a relative humidity of 75% for 90 days had little effect on the properties of the microspheres. Intravitreal injection of microspheres showed a sustained release and continuous action of dexamethasone acetate for 84 days. After injection of activated macrophages, the groups of blank microspheres and dexamethasone acetate showed proliferation to different extent, while the base of the eye remained clear and no obvious proliferation was observed for the group of microspheres. A significant difference exists between these three groups. CONCLUSION: Poly (d, l-lactide) microspheres containing dexamethasone acetate is a potentially promising delivery system for the suppression of proliferative vitreoretinopathy.

Animals↗
PubMed2001

Effects of the HOE 694 on transient inward current and Na(+) - Ca(2+) exchange in guinea pig cardiomyocytes.

OBJECTIVE: To determine the effects of HOE 694, a new and potent Na(+)-H+ exchanger blocker, on transient inward current (It(i)) and Na(+) - Ca(2+) exchange during hypoxia-reoxygenation in guinea pig cardiomyocytes. METHODS. Cardiomyocytes were isolated from adult guinea pig ventricle. Experiment was performed in an experimental chamber that allowed the cells to be exposed to a sufficiently low O2 pressure. The cells were subjected to hypoxia and reoxygenation. The ionic currents were studied with patch clamp technique. RESULTS: In the absence of HOE 694, hypoxia-reoxygenation induced It(i) in 12 of 15 experiments; but in cardiomyocytes pretreated with HOE 694 (10 approximately 50 micro mol/L), the incidence of It(i) observed during reoxygenation was reduced to 5 of 11 experiments and 3 of 10 experiments, P < 0.05 vs control respectively. The Na(+) - Ca(2+) exchange current was unaffected by HOE 694 under normoxic condition. However, when cells were pretreated with 10 micromol/L HOE 694 for 10 min, then subjected to hypoxia condition, the Na(+) - Ca(2+) exchange current significantly inhibited. CONCLUSIONS: Blockade of the Na(+)-H+ exchange by HOE 694 could reduce Ca(2+) overload upon hypoxia-reoxygenation, and inhibition of Na(+) - H+ exchange may also indirectly decrease Na(+) - Ca(2+) exchange activity during hypoxia.

Animals↗
PubMed2001

[Construction and expression of huGM-CSF (9-127)-IL-6(29-184) fusion protein gene].

OBJECTIVE: To construct and express huGM-CSF(9-127)-IL-6(29-184) fusion protein with high purity and both huGM-CSF and huIL-6 biologic activities. METHODS: The novel gene coding for the fusion protein of huGM-CSF(9-127)-IL-6(29-184) was constructed by strategy of step by step cloning in pBV220 expression vector. The amino acids 1-8 of huGM-CSF and the amino acids 1-28 of huIL-6 were deleted by PCR technique. The mutant huGM-CSF (9-127) and huIL-6 (29-184) cDNAs were linked via a linker sequence coding 15 amino acid residues (G-G-S-G-S)3. Fusion protein was expressed in E.coli host strain DH5 alpha. To obtain the fusion protein, Q Sepharose H.P. ion exchange chromatography and Sephacryl S-200 gel filtration were performed. The biologic activities were detected by MTT method. RESULTS: Fusion protein was expressed in E.coli host strain DH5 alpha in the form of inclusion body. The expression level was more than 25% of the total cell lysate. Through Q Sepharose H.P. ion exchange chromatography and Sephacryl S-200 gel filtration, huGM-CSF(9-127)-IL-6(29-184) fusion protein with high purity was obtained. The protein showed both huGM-CSF and huIL-6 biologic activities. The specific activity of huGM-CSF was 1.08 x 10(8) U/mg, and for huIL-6, it reached 1.95 x 10(7) U/mg. CONCLUSION: huGM-CSF(9-127)-IL-6(29-184) fusion protein with high purity and both huGM-CSF and huIL-6 biologic activities was obtained.

Cloning, Molecular↗
PubMed2001

Gut barrier function damage following multiple firearm injuries in a porcine model.

OBJECTIVE: To study the characteristics and pathogenesis of gut barrier damage following multiple firearm injuries in a porcine model. METHODS: Twenty-four small pigs were divided into 4 groups: control group (n = 6, group C), group H (n = 6, gunshot-induced tangential fracture of parietal bone), group L (n = 6, gunshot-induced comminuted fracture of bilateral femora) and group M (n = 6, combined group H + L). Gastric intramucosal pH (pHi), plasma endotoxin levels in portal vein, and plasma D-lactate levels were measured and blood samples were cultured at different intervals after trauma. The animals were sacrificed at 72 h following trauma and intestinal tissues were harvested for pathological examination and diamine oxidase (DAO) activity measurement. RESULTS: In group M at 72 h, pHi was significantly lower than that of group H and L ( P < 0.01), and plasma endotoxin level was significantly higher than that of group H (P < 0.01) and group L (P < 0.05). Simultaneously, in group M, D-lactate level was markedly higher than that of group H ( P < 0.01), and incidence of positive blood culture was much higher than that of group H and L ( P < 0.05). Necrosis and exfoliation were revealed at ileum villus top in all trauma groups, especially in group M, in which ileum DAO activity declined most significantly as well. CONCLUSION: Multiple trauma is prone to cause gastrointestinal ischemia even without hemorrhagic shock. The damage of gut barrier in multiple trauma appears to be more severe than that in one-site trauma, thereby promoting gut-derived endotoxemia and bacterial translocation and contributing to the development of endogenous infection.

Amine Oxidase (Copper-Containing)↗
PubMed2001

[Substitution of diphenyl sulfurine to trinuclear clusters and infrared spectra characterization].

Substitution of diphenyl sulfurine to dodecarbonyl-triruthenium and dodecarbonyl-triiron were studied respectively. Infrared spectra were used in characterization of the reactions and to follow the reaction processes from starting to finishing. Spectra data showed that the new compounds appeared and starting materials disappeared. The results products Ru3 (CO)9CSN2HPh2 and Fe3 (CO)8S2CNPh were taken in KBr pellet infrared spectras. C, S and N in diphenyl sulfurine might coordinate to transitionmetal atoms in the clusters. Since trinuclear ruthenium and iron clusters have different stability and diphenyl sulfurine induced attacked to cluster skeleton in reaction, Ru3 (CO)12 and Fe3 (CO)12 give different coordination structure trinuclear Ru and Fe clusters, in which every metal atom forms 18 e constitution.

Iron↗
PubMed2001

[Study on determination of trace cadmium in Chinese medicine loulu by graphite furnace atomic absorption spectrometry].

A method for the determination of trace cadmium in chinese medicine Loulu by graphite furnace atomic absorption spectrometry (GFAAS) has been described. The matrix modifier and its proper concentration, the influence factors including ashing and atomization temperature, atomization time and coexisting ions were investigated. Under the optimum experimental conditions, the detection limit and the relative standard deviation of the method were 0.06 ng.mL-1 and 2.43% (n = 11), respectively. The recovery was between 97% and 105%. The method is simple, rapid and accurate, and can eliminate the matrix effect. It has been applied to the direct determination of trace cadmium in chinese medicine Loulu with satisfactory results.

Cadmium↗
PubMed2001

[Determination of Se, Fe, Si in electrolytic manganese metal by ICP-AES].

The method was established for the simultaneous determination of Se, Fe and Si in electrolytic manganese metal by inductively coupled plasma atomic emission spectrometry (ICP-AES). The sample was dissolved by light sulphuric acid. The analysis conditions were obtained by studying dissolved acid, Mn matrix and background. The recommended method not only proved to be simple and rapid but showed satisfying precision and accuracy as well. The relative standard deviation is less than 2.68% and the recovery is 98%-105%. The t-test showed that no conspicuous difference with typical methods was found.

Electrolysis↗
PubMed2001

[Direct determination of Pb, Zn and Cd in environmental and biological samples by FAAS].

This paper describes interference and background correction problem of direct determination of Pb, Zn and Cd in soil, sediment, plants, halobios and sea water by FAAS. With the improvement of limit of detection(L.O.D) of instrument, Pb, Zn and Cd in same environmental and biological samples can be analyzed directly by FAAS, but it is worth taking attention that there are quantities of elements which lead to background interference in air-ethyne flame, such as Al, Na, K Ca, Mg and Fe. Compare with no background correction, limit of detection using D2 lamp background correction is improved by 1.05-4.5 times, the recoveries and the relative standard deviation(R.S.D) are better, standard samples were also analyzed with satisfactory results.

Animals↗
PubMed2001

[Diagnosis and treatment of ectopic molar pregnancy].

OBJECTIVE: To summerize the experience in the diagnosis and treatment of ectopic molar pregnancy. METHODS: Clinical data of 3 cases of women with ectopic hydatidiform mole in Peking Union Medical College Hospital were analyzed retrospectively. RESULTS: The clinical characteritics of ectopic molar pregnancy depend upon the site of the disease. It can be metastasized distantly in early stage. Digital subtraction angiography, colour ultrosound and laparotomy may play very important roles in the diagnosis of ectopic molar pregnancy. Regular chemotherapy and resection of drug-resistant focus are still the main methods of treatment. CONCLUSIONS: Prophylactic chemotherapy for ectopic molar pregnancy should be emphasized. It is very important to make an early diagnosis of malignant metastasis and to give a regular treatment for the patients.

Angiography, Digital Subtraction↗