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Biomedical subjects

H Xu

Publications and source records attributed to H Xu.

At least 181 records · Page 10Linked to original sources
PubMed2001

[Study on the tissue culture and plant regeneration of Pogostemon cablin].

Root tips, leaf segments, stem segments with node and stem segments of Pogostemon cablin (Blanco) Benth. were cultured in vitro. The results indicated that leaf segments and stem segments with node were suitable for callus formation, the frequency of callus induction were over 87.0%. A optimal medium for callus induction was MT + BA 0.5 mg/L + NAA 0.2 mg/L. MT basal medium with BA 0.5-1.0 mg/L were effective to induce differentiation of callus. And at the MT basal medium, the regenerative shoots from Pogostemon cablin could form roots.

Culture Media↗
PubMed2001

[Quantitative assay of metabolic rate of para-aminobenzoic acid combining glycine for the assessment of rabbit liver function].

OBJECTIVE: To evaluate liver function by the assessment of the capacity of glycine combining para-aminobenzoic acid (PABA) to form hippuric acid in rabbits with acute liver injury. METHODS: Thirty rabbits were randomly divided into two groups: experiment group (n=20) received D-galactosamine to be subject to acute liver necrosis, and control group (n=10) received saline as placebo. Serum concentrations of PABA, para-aminohippuric acid (PAHA), para-acetamidobenzoic acid (PAABA), and para-acetamidohippuric acid (PAAHA) were measured by high pressure liquid chromatography (HPLC). RESULTS: Compared with control group, the serum concentrations of PAHA and PAAHA were significantly reduced in experimental group, which were correlated with the degree of liver injury. CONCLUSIONS: The metabolic rate of glycine combining PABA is a sensitive index for quantitative test of liver function and assessment of acute liver necrosis.

4-Aminobenzoic Acid↗
PubMed2001

Clarithromycin-induced digoxin toxicity: a case report and a review of the literature.

A 70-year-old woman with a history of atrial fibrillation, on digoxin, presented with nausea, vomiting, and dizziness two days after initiation of clarithromycin therapy. Laboratory results revealed a serum digoxin level of 3.9 ng/ml (normal range 0.5-2.0) and creatinine of 1.1 mg/dl. The patient was admitted to the hospital and digoxin and clarithromycin were discontinued. The patient's symptoms were resolved within 24 hours and her serum digoxin level was 1.9 on the second hospital day. A review of recent literature suggests that clarithromycin may induce digoxin toxicity by three different mechanisms, including reduction of renal excretion of digoxin, alteration of intestinal flora, and inhibition of cytochrome P-450 in the liver. Digoxin toxicity was reported three to 17 days after the initiation of clarithromycin (8.1 +/- 4.8 days, n = 9). The wide variation in the time required for the appearance of toxicity may imply the different mechanisms involved in each case.

Aged↗
PubMed2001

[Therapeutic effects of nitroglycerin on pregnancy induced hypertension].

OBJECTIVE: To evaluate the effects and possibility of nitroglycerin on Pregnancy induced hypertension (PIH) treatment. METHODS: In comparison with the third trimester normal pregnant women (Normal group) (n = 11), 34 moderate/severe PIH cases were divided into three groups: PIH treated only with magnesium sulfate (Mg group) (n = 11); PIH treated only with nitroglycerin (Ng group) (n = 11); and PIH treated with Mg + Ng (Combination group) (n = 12). The endothelial nitric oxide synthase (eNOS) in placenta was investigated immunohistochemically and quantitatively. Data such as platelet aggregation (PAg), umbilical artery of S/D ratio and resistance index (RI) with color Doppler and the effect of decrement of blood pressure on PHI groups were evaluated. RESULTS: In comparision with Normal group, (1) the quantity of eNOS of PIH cases was significantly lower (P < 0.01). (2) umbilical artery S/D ratio and RI in Ng group were significantly lower after introvascular drip of Ng (P < 0.05). (3) Pag in Ng group and Combination group decreased significantly after treatment (P < 0.01), but no difference in Mg group. (4) the decrement of blood pressure on PIH groups, compared with Mg group, was significant in Ng group and Combination groups (P < 0.05). CONCLUSIONS: Ng can reduce blood pressure, fetal-placenta circulation resistance, and inhibit PAg. It probably play a role on intrauterine growth retardation (IUGR) caused by PIH.

Adult↗
PubMed2001

Effects of soybean fibers on blood sugar, lipid levels and hepatic-nephritic histomorphology in mice with diabetes mellitus.

OBJECTIVE: To study the influence of soybean fibers on blood sugar, blood-lipid metabolism, and histomorphology in mice models with diabetes mellitus (DM). METHOD: After normal mice and mice with Streptozocin (STZ)-induced DM were fed with forage containing a certain amount of soybean fiber (SF) for 5 weeks, blood sugar and blood lipid were determined, and morphological changes of hepatic and nephritic tissues were observed. RESULT: The results of 5-week experiment had shown: 1. In normal mice fed with SF, the blood sugar level was decreased (P < 0.05). There were no obvious changes in serum total cholesterol (TC) and the triglyceride (TG). The high-density-lipoprotein cholesterol (HDL-C) level was increased significantly (P < 0.05); 2. Among DM mice, blood sugar was decreased considerably (P < 0.001), TC and TG also decreased noticeably (P < 0.05), HDL-C increased clearly (P < 0.05); 3. SF has a protective role to the liver and kidney of DM mice. CONCLUSION: It is suggested that SF has the function of decreasing blood sugar, blood-lipid and improving their metabolism, and of protecting liver and kidney of DM mice.

Animals↗
PubMed2001

[Expression of human leucocyte antigen in ectopic endometrial tissue of endometriosis].

OBJECTIVE: To investigate the human leucocyte antigen (HLA) expression of ectopic endometrial epithelial cells in cases with endometriosis and its role in pathogenesis of endometriosis. METHODS: By immunohistochemical analysis, HLA expression was observed in ectopic endometrial epithelial cells of 25 endometriosis patients. Ectopic endometrial cells were cultured in vitro successfully and the expression of HLA were analyzed by flow cytometry in 10 out of the 25 patients. Eutopic endometrium of 15 normal women were taken as control. RESULTS: (1) Expression of HLA class I molecule on ectopic endometrial epithelial cells of endometriosis measured by the immunohistochemical analysis was lower than those of controls, (4.0 +/- 0.5) score and (1.2 +/- 0.8) score respectively. So was the expression rate by flow cytometry in vitro culture (63.38 +/- 11.88)% and (5.27 +/- 2.88)% respectively (P < 0.01). (2) The expression of HLA class II molecule on ectopic endometrial epithelial cells of endometriosis was significantly increased. The outcome by immunohistochemical analysis was (0.2 +/- 0.1) score (control group) and (4.1 +/- 0.7) score (case group) and by flow cytometry was (7.19 +/- 2.43)% and (58.57 +/- 14.99)% respectively (P < 0.01). CONCLUSIONS: The abnormal HLA expression could play a role in the pathogenesis of endometriosis.

Adult↗
PubMed2001

[Investigation of the clinicopathologic features, immunophenotype and Epstein-Barr virus infection of primary central nervous system lymphoma].

OBJECTIVE: To investigate the clinicopathological features, immunophenotypes and EB virus infection of 25 cases of primary central nervous system lymphoma (PCNSL). METHODS: Immunohistochemical staining was performed using monoclonal antibodies, L26 (CD20), kappa,lambda for B lymphocytes, UCHL-1 (CD45RO) for T lymphocytes, CS1-4 for latent membrane protein-1 (LMP-1) and GFAP for gliocytes. In situ hybridization was used for detection of EB virus encoded small nuclear RNAs (EBER1/2). RESULTS: All of the 25 PCNSL were of B lymphocyte origin with high-grade malignancy. Only 2/25 (8%) cases showed positive signal in EBER1/2 in situ hybridization. CONCLUSION: This group of PCNSL were all B-cell lymphomas, and the role of EB virus in this group of PCNSL was uncertain.

Adolescent↗
PubMed2001

[Characteristics and distribution pattern of farmland patch in river valley in middle and low Taihang mountain area--a case study in Yanzhi River in Fuping County, Hebei Province].

Based on the investigations in the main valley of Yanzhi river in Fuping county of Hebei Province, the characteristics and distribution patterns were analyzed. The results indicated that farmland patches were distributed in the whole valley, except the headstream reach. With the increase of human disturbances, the proportion of farmlands increased along the river from upstream to downstream, while in natural landscapes, the environmental heterogeneity and fragmentation of farmlands decreased. The area of Yanzhi river valley totaled 2297.09 hm2, mainly composed by farmland. There were 117 farmland patches mainly distributed along the riverbank in the valley, totalling 1027.78 hm2 and occupying 44.74% of the valley, which were very well irrigated, but always endangered by flood. The farmland patches were not symmetrically distributed along river, with 57.17% of farmland located on the left side of bank. The width of farmland patch presented an increasing trend, with a remarkable variation. The farmland patches were mainly strip-shape.

Agriculture↗
PubMed2001

[N2O emission by trees under natural condition].

The sources of N2O, one of the major greenhouse gases in the atmosphere, are still unclear till now. It was previously thought that only soil microbial process produced N2O. The aim of this study was to provide evidences that plant can emit N2O under the natural condition. The measurement of aboveground vertical profiles of N2O concentrations were conducted within coniferous-deciduous mixed forests in Changbai Mountain, China. Significant high N2O concentrations were found at or near the height of canopy. High concentrations in profiles were 3.03% to 64.9% higher than the "normal concentrations". Differences between the high concentrations and the "normal concentrations" were statistically significant. The simultaneous occurrence of high concentrations at/nearby the canopy height and normal concentrations at the trunk space height indicated an efflux of N2O from foliage to atmosphere. This study afforded evidences supporting that plant per se, besides forest soil, was an important source of atmospheric N2O in a forest ecosystem.

Air↗
PubMed2001

[Study on the rat airway epithelial cell injury induced by bacterial infection and its pathogenesis].

OBJECTIVE: To explore the rat airway, especially small airway epithelium injury induced by Klebsiella pneumoniae infection and its pathogenesis. METHODS: A rat airway inflammation and COPD model was induced by repeated intranasal infection with Klebsiella pneumoniae. The injury changes were dynamically observed under SEM, TEM and LM. Actin, TNF-alpha, Fos, Jun protein and their mRNA expression levels in small airway epithelium were analyzed by immunohistochemistry and in situ hybridization. The changes of lung TNF-alpha content were examined by radioimmunoassay. RESULTS: 1 week after Klebsiella pneumoniae infection the epithelial cilia cohered, fell down, partially fell off and the tight intercellular connection destroyed. 2 and 4 weeks after the infection, the injury of bronchus epithelia worsened with pronounced chronic inflammation in all bronchi. The bronchioles walls became thickened, lumen narrowed and emphysema was noted. Compared with control group, TNF-alpha mRNA expression was higher (P < 0.01) in the 2nd and 4th week while TNF-alpha protein was higher at 4 weeks (P < 0.01). From 1st week after the infection, Fos protein and mRNA expression began to elevate (P < 0.01). TNF-alpha content of lung began to increase (P < 0.01) and kept at a higher level until the 8th week. CONCLUSIONS: Repeated intranasal injection of a certain amount of Klebsiella pneumoniae can induce airway inflammation and emphysema. The main features of early airway epithelia injury are damage of cilia and intercellular junctions, the cause of which may be associated with changes in microfilament arrangement of epithelia. High expression of TNF-alpha protein in the airway epithelia and lung parallels with epithelium injury. Fos and Jun proteins may also play important roles in up-regulating the TNF-alpha protein.

Animals↗
PubMed2001

[The clinical significance of E-cadherin and alpha-catenin expression in human gastric cancer].

OBJECTIVE: To evaluate the expression of cell adhesion molecules E-cadherin (E-CD) and alpha-catenin (alpha-CA) in relation to biologic behavior of gastric cancer. METHODS: The level of E-CD and alpha-CA expression was examined in 70 cases of primary gastric cancer by immunohistochemical technique. RESULTS: The rate of E-CD and alpha-CA expression was significantly reduced in gastric cancer with more prominent malignant phenotype, such as tumor in stage III/IV with poor cell differentiation, invasion through serosa and lymph node (LN) metastasis. With the increase in the number and frequency of LN metastasis and its dissemination distal to second group LNs, the reduction in expression of the two adhesion molecules was increasingly significant. The frequency of LN metastasis and shed cancer cells in the peritoneum in patients with E-CD(-)/alpha-CA(-) and E-CD(+)/alpha CA(-) cancer were significantly higher than those in patients with E-CD(+)/alpha-CA(+) tumor. Liver metastasis was most frequent in all cases with E-CD(+)/alpha-CA(-) tumor. CONCLUSION: Down regulation of E-CD and/or alpha-CA correlates with the malignant behavior of gastric cancer. Examination of E-CD and alpha-CA expression in primary gastric cancer helps evaluate its intensity of LN metastasis, TNM staging and prognosis.

Cadherins↗
PubMed2001

[Immunogenicity of phage-displayed tumor antigen-mimic peptide].

OBJECTIVE: To determine the immunogenicity of phage-displayed tumor antigen-mimic peptide, and to lay experimental foundation for the development of gastric cancer vaccine. METHODS: Based on previous studies, two phage-displayed peptide libraries were screened and 12 and 30 positive phage clones obtained from two libraries respectively. All the positive phages were purified and used them to immunize Balb/c mice. The immune serum was screened by immunohistochemical with tissue sections of human gastric cancer expressing MG7 antigen. The result was further confirmed by fluorescence labeling and ELISA. RESULTS: Through immunohistochemical screening of immune sera with tissue sections of human gastric cancer, one phage displayed mimic peptide was able to elicit production of antibody specific for human gastric cancer. CONCLUSION: The result demonstrates that it is possible to develop tumor vaccine based on antigen epitope mimic peptide with immunogenicity.

Animals↗
PubMed2001

[Bioremediation of mineral oil and polycyclic aromatic hydrocarbons (PAHs) in soils with two plant species].

With alfalfa (Medicago sativa) and paddy rice as test plants, and with pollutant level, specific bacteria, fungi and organic fertilizer as control factors, the bioremediation of mineral oil and polycyclic aromatic hydrocarbons (PAHs) in soils with two plant species was conducted. The results showed that the degradation rate of mineral oil was promoted by fertilization in alfalfa soil, but not in paddy rice soil. The degradation rate of total PAHs (11 PAH listed in USEPA) was increased by fertilization both in alfalfa and in paddy rice soil, and the promotion effect of fertilizer was better in paddy rice soil than in alfalfa soil. The fertilization rate was positively related to the rhizospheric indigenous fungi and bacteria's CFU in alfalfa soil, but only to the indigenous bacteria's CFU in paddy rice soil. The fungi and bacteria's CFU in both test soils had no positive relation with the amount of specific bacteria and fungi spiked. The degradation rate of 3-ring PAHs was enhanced in both alfalfa and paddy rice soil by fertilization, and the effect was stronger in paddy rice soil than in alfalfa soil. However, fertilization had no positive effect on the degradation of 4-ring PAHs.

Bacteria↗
PubMed2001

Animal study on lung injury caused by simulant segmented shock waves.

OBJECTIVE: To study the lung injury caused by segmented shock waves. METHODS: A total of 60 rabbits and 20 rats were used in this study. The process of transmission of shock waves was divided into three phases, i.e., the recompression phase (RP), the decompression phase (DP) and the underpressure phase (UP). And the recompression wave (RW), the decompression wave (DW) a nd the underpressure wave (UW) simulated the three phases, respectively, generated by the equipment designed by us. The RW test, DW test and UW test were respectively applied to the animals. And lung injuries caused by segmented shock waves were discussed. RESULTS: Under the experimental conditions, the RW did not cause obvious lung injury, but the DW could cause different severities of lung injuries. The greater the decompression ranged and the shorter the decompression duration was adopted, the more severe the lung injury was observed. The UW, to some extent, could cause obvious lung injury. CONCLUSIONS: It suggests that lung injury under shock waves probably occurs during the DP primarily. It probably does not cause direct obvious lung injury during the RP, but significantly influences the capability of causing lung injury during the DP.

Animals↗
PubMed2001

[Inhibition of proliferation and induction of apoptosis by simvastatin in K562 leukemic cell line].

OBJECTIVE: To investigate the anti-apoptotic mechanism and explore approach to inhibiting proliferation and inducing apoptosis of chronic myclogenous leukemia (CML) cells. METHODS: K562 cell line was used to evaluate the effects of simvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, and the combination of simvastatin with chemotherapeutic agents on the proliferation and apoptosis of CML cells. RESULTS: Simvastatin could significantly inhibit proliferation and induce apoptosis of K562 cells, and could increase the sensitivity of K562 cells to chemotherapeutic agents. Addition of mevalonate, the immediate product of HMG-CoA, could completely reverse this effect. CONCLUSION: Simvastatin inhibited proliferation and induced apoptosis of K562 cells through inhibiting the metabolic pathway of mevalonate. It is promising that HMG-CoA reductase inhibitors may be an effective chemotherapeutic approach to the treatment of CML.

Antineoplastic Agents↗
PubMed2001

[Study on immunonodulating activities of enzymolyzed loach protein].

The immunomodulating activities of enzymolyzed loach protein in mice were investigated by regular methods for immunology evaluation. The doses of enzymolyzed loach protein were 0.1, 0.2, 0.4 g.kg-1 bw, which were 5, 10, 20 times respectively as large as the recommended daily intake(0.02 g.kg-1 bw). After being successively fed with enzymolyzed loach protein at given doses for 30 days by ig respectively, the mice were detected by immunomodulation tests. The results indicated that enzymolyzed loach protein had significant modulating effects on all of test indexes and suggested it had apparent immunomodulating activities in mice. Based on the results described above, we speculate that the enzymolyzed loach protein may have immunomodulating functions and can enhance the immunity of body.

Adjuvants, Immunologic↗
PubMed2001

[Studies on tissue culture of Dendrobium chrysotoxum Lindl in vitro].

OBJECTIVE: To set up a system for the culture of Dendrobium chrysotoxum in vitro. METHOD: Tissue culture, fire fly luminescence and phenol-H2SO4 method. RESULT: The embryo could germinate with or without light, the MS, 1/2MS, B5, N6 mediums are suitable to the growth and the differentiation of sprout with light, 0.5 mg.L-1 NAA and 1 mg.L-1 6-BA, and ATP have regular changes, the content of polysaccharide was 2.833% in plant and 7.254% in sprout. CONCLUSION: The light has no effects on the embryo germination, but the phytohormone, nitrogen source and organized elements are important to the growth and differentiation of the sprout which should be transferred to the MS, 1/2MS, B5, N6 mediums in time supplemented with NAA [symbol: see text] 6-BA, ATP may be served as the dynamic indication of nourishment demand in the plant. The content of polysaccharide in the sprout is higher and can be utilized.

Culture Techniques↗