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Biomedical subjects

D Che

Publications and source records attributed to D Che.

At least 37 records · Page 2Linked to original sources
PubMed2001

[The effects of iron compounds on SO2 and NO emissions in coal combustion process].

The effects of ferric/ferrous chlorides and ferric oxide on emissions in Tongchuan coal combustion process were experimentally investigated using thermogravimetric analyzer. The results show that all iron compounds used in the experiments, namely FeCl3, FeCl2 and Fe2O3 can change the emissions of SO2 and NO, but with different mechanisms and different magnitudes. FeCl3 plays the roles of both a catalyst and an absorbent in the conversions from coal-S to SO2 and from coal-N to NO. Due to the catalysis the activation energy required for the formation of SO2 and NO is reduced, the rates of the reactions leading to SO2 and NO increased. The catalysis is concerned with the forms of coal sulfur. Due to the absorption FeCl3 reacts with SO2 to produce FeSO4 [symbol: see text] Fe2(SO4)3. In addition FeCl3 can decrease the emissions of CO, i.e., the combustion characteristics can be changed. The effects of FeCl2 on the emissions of SO2, NO and CO are similar to those of FeCl3, but weaker. Fe2O3 can also decrease the SO2 and NO emissions to some extent, but has negligible influence on CO emission.

Catalysis↗
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

[Effects of DDPH on proliferation and immunophenotypes of the pulmonary vascular pericytes].

OBJECTIVE: To study the effects of 1-(2, 6-dimethylphenoxy)-2-(3, 4-dimethoxyphenylethylamino) propane hydrochloride (DDPH) on proliferation and immunophenotypes of newborn rat pulmonary vascular pericytes (PCs) induced by hypoxic endothelial cell conditioned medium (HECCM) from porcine pulmonary arteries. METHODS: The PCs were divided into 4 groups according to the endothelial cell conditioned medium (ECCM): normoxic ECCM (NECCM) group, NECCM + DDPH group, HECCM group and HECCM + DDPH group. Cell culture, immunocytochemical staining, image analysis and flow cytometry were used to investigate the effects of HECCM and DDPH on the expression of alpha-smooth muscle actin (alpha-SM-actin) and proliferating cell nuclear antigen (PCNA) and cell cycle in PCs. RESULTS: The alpha-SM-actin antigen in the PCs in HECCM group was more positively expressed than that in the other three groups, but CD(34) antigen and S-100 antigen were negatively expressed. The expression of alpha-SM-actin antigen, CD(34) and S-100 was positive in the groups of NECCM, NECCM + DDPH and HECCM + DDPH. The expression of alpha-SM-actin and PCNA in HECCM group was 1.32 times (F = 11.09, P = 0.000 1) and 1.24 times (F = 2.89, P = 0.025 7) that in NECCM group, 1.30 times (F = 3.65, P = 0.007 0) and 1.21 times (F = 2.63, P = 0.041 4) that in HECCM + DDPH group, respectively; The percentage of the cells in the G(0)-G(1) phase in the HECCM group was lower by 11.7% and 9.1%, in S phase higher by 5.6% and 4.2%, in G(2)-M phase higher by 6.1% and 4.9% than that in the groups of NECCM, HECCM + DDPH, respectively. The inhibitory rates of DDPH on the increased alpha-SM-actin and PCNA syntheses in PCs induced by HECCM were 23.4% and 17.1% respectively. The inhibitory rate on the increased PCs from G(0)-G(1) phase to S phase was 8.3%. CONCLUSION: DDPH might directly inhibit PCs from proliferation and immunophenotypical transformation of smooth muscle-like cells induced by HECCM.

Actins↗
PubMed2000

Molecular cloning of a regulatory protein for membrane-bound guanylate cyclase GC-A.

Activation of membrane-bound guanylate cyclase GC-A by atrial natriuretic factor (ANF) may require the involvement of accessory proteins. To identify these postulated proteins, we isolated a 1. 0-kb cDNA clone from a rat brain expression library using a polyclonal antiserum against mastoparan. The 1.0-kb cDNA encodes a protein of 111 amino acids. Expression of this cDNA in COS-7 cells potentiated ANF-stimulated GC-A activity. Therefore, the 1.0-kb gene encodes a guanylate cyclase regulatory protein (GCRP). Fluorescence microscopy studies using the fusion protein of GCRP with green fluorescence protein (GFP) indicated that GCRP was present in the cytosol in PC12 cells, but translocated toward the plasma membrane in the presence of ANF. Coimmunoprecipitation experiments indicate that GCRP associates with GC-A in the presence of ANF. These results suggest that ANF induces the association of GCRP with GC-A and this association contributes to the activation of GC-A.

Amino Acid Sequence↗
PubMed2000

Effect of c-myc antisense oligodeoxynucleotides on hypoxia-induced proliferation of pulmonary vascular pericytes.

To study the effect of c-myc antisense oligodeoxynucleotides (ODNs) on proliferation of pulmonary vascular pericytes (PC) induced by hypoxia, cell culture, dot hybridization using probe of digoxigenin-11-dUTP-labeled cDNA, 3H-thymidine incorporation, immunocytochemical technique and image analysis methods were used to observe the effect of c-myc antisense ODNs on expression of c-myc gene and proliferating cell nuclear antigen (PCNA), and 3H-thymidine incorporation of PC induced by hypoxia. The results showed that hypoxia could significantly enhance the expression of c-myc and PCNA (P < 0.01), and elevate 3H-thymidine incorporation of PC (P < 0.01), but antisense ODNs could significantly inhibit the expression of c-myc and PCNA (P < 0.05), and 3H-thymidine incorporation of PC (P < 0.01). It was suggested that hypoxia could promote the proliferation of PC by up-regulating the expression of c-myc gene, but c-myc antisense ODNs could inhibit hypoxia-induced proliferation of PC by downregulating the expression of c-myc gene.

Animals↗
PubMed2000

Relationship between the expression of alpha 1-antitrypsinase in bronchioalveolar carcinoma and clinical pathology.

By using immunohistochemistry LSAB method and imaging analysis technique, the expression of alpha 1-antitrypsinase (alpha 1-AT) in 41 cases of bronchioalveolar carcinoma (BAC) was quantitatively detected to explore the relationship between alpha 1-AT expression in BAC tissues and clinical pathology. The results showed that the total positive rate for alpha 1-AT expression was 85.4%. The positive rate for alpha 1-AT expression in alveolar BAC was 100%, with the immunity reactive staining intensity being significantly higher than in papillary BAC, mucinous BAC or sclerosing BAC (P < 0.05). The positive rate in papillary BAC was 93.3%, with the intensity higher mucinous BAC or sclerosing BAC (P < 0.01); The positive rate in both mucinous BAC and sclerosing BAC was 66.7% (P > 0.05); The expression intensity in lymph node metastatic group was obviously lower than that in the group without metastasis (P < 0.01); The patients with mucinous BAC were diagnosed at a younger age than those with other histologic types of BAC (P < 0.05). It was suggested that BAC cells could also produce alpha 1-AT. Detection of alpha 1-AT could be used as a new method to diagnose BAC and might play a role in assessing BAC metastasis.

Adenocarcinoma↗
PubMed2000

The effect of hypoxia on expression of basic fibroblast growth factor in pulmonary vascular pericytes.

To examine whether hypoxia exerts effect on the expression of basic fibroblast growth factor (bFGF) in pulmonary vascular pericytes (PC), cell culture, in situ hybridization with probe of digoxigenin-11-dUTP-labled cDNA, immunocytochemistry and image analysis were employed in this study. The results showed that the expression amount of bFGF mRNA and protein in PC of hypoxia (H) group was 1.31 times (P < 0.01) and 1.17 times (P < 0.01) that of normoxia (N) group respectively. It suggests that hypoxia can directly enhance the expression of bFGF mRNA and protein in PC. Increased expression of bFGF may play an important role in the process of PC proliferation and differentiation of PC into smooth muscle-like cells.

Animals↗
PubMed1999

Adaptation of capillary isoelectric focusing to microchannels on a glass chip.

As a first step toward adaptation of capillary isoelectric focusing (cIEF) to microchannels on a glass chip, we have compared the three most common mobilization methods: chemical, hydrodynamic, and electroosmotic flow (EOF)-driven mobilization. Using a commercial cIEF apparatus with coated or uncoated fused-silica capillaries, both chemical and hydrodynamic mobilization gave superior separation efficiency and reproducibility. However, EOF-driven mobilization, which occurs simultaneously with focusing, proved most suitable for miniaturization because of high speed, EOF compatibility and low instrumentation requirements. When this method was tested in a 200-micron-wide, 10-micron-deep, and 7-cm-long channel etched into planar glass, a mixture of Cy5-labeled peptides could be focused in less than 30 s, with plate heights of 0.4 micron (410 plates/s) upon optimization. For a total analysis time of less than 5 min, we estimate a maximum peak capacity of approximately 30-40. Interestingly, the order of migration was found to be reversed compared to capillary-based focusing.

Glass↗
PubMed1999

Establishment of the culture technique of pulmonary vascular pericytes and its identification in rats.

In order to study the cellular origin of muscularization in non-muscular arterioles of the lung, the pulmonary vascular pericytes-culture was established. The terminal lung tissue of the rat was taken out and minced. Then 0.5% of type IV collagenase solution was added for digestion and the microvascular segments were obtained by screening. The targeted cells were cultured by "selective conditioned media". Under phase-contrast microscope, the cultured cells were large in size with ragged margin and numerous pseudopodia, which imparted tubule-like structure. There was no contact inhibition in growing cells, so multiple layers developed. When they were confluent, there were morphologically no "hillock and dale" growth pattern as in smooth muscle cells or "weave-like" pattern as in fibroblasts. The ultrastructure of cultured cells showed numerous digital processes, moderate amount of rough and smooth endoplasmic reticulum, rich Golgi's apparatus, microfilaments, few lysosomes without myofilaments and dense bodies. Immunohistochemical staining revealed that the cultured pericytes had same kind of cellular skeletal protein, alpha-SM-actin, like smooth muscle cells. The cultured cells also exhibited positive reaction to CD34 antigen and S-100 antigen, which were negative in smooth muscle cells and fibroblasts. The cell growth pattern, ultrastructure and immunological phenotype suggested that the cultured cells had characteristics of vascular pericytes. Pericytes are one of the components of microvascular cells, and the establishment of in vitro culture technique of pericytes is of significance for further exploration of the muscularization of non-muscular arterioles in lung and the mechanism of structural remodeling of pulmonary vessels.

Animals↗
PubMed1999

[Chronic obstructive pulmonary disease and pulmonary structural remodeling].

OBJECTIVE: To understand the pathological characteristics of the lungs in 20 autopsy cases of chronic obstructive pulmonary disease(COPD) complicated with cor pulmonale and its relationship with structural remodeling of the lungs. METHODS: The lungs of 20 autopsy cases of COPD complicated with cor pulmonale were fixed in 10% formalin or by low pressure 18.4-33.4 mm Hg perfusion with 10% formalin. The lungs were cut sagitally into large slices with 2 cm in thickness, and the percentage of the emphysematous areas was calculated by point counting. The pathological characteristics of bronchioles and the stromal fibrosis area were examined microscopically and quantitatively using a latticed micrometer (Zeiss). The distribution and the ratio of type I to type III collagen in the lung tissue were determined using a sirius red-polarizing microscopy-morphmetry method. RESULTS: Of the 20 cases of COPD, irregular and saccular emphysema were the most frequent (17/20). 10 cases had moderate and high degree of emphysema, and 6 cases showed hypertrophy of the right ventricle (heart weight > 400 g). The mean area of stromal fibrosis auounted for total area of the examined lungs was (27.1 +/- 2.9)% and control group (12.0 +/- 1.8)%. The ratio of the area of the type I collagen to type III collagen was 5.6:1 (control group 1.3:1). All 1504 bronchioles showed chronic inflammation, 38% of which revealed acute exacerbation, and 53% of which showed lumen stenosis and fibrotic obstruction. CONCLUSIONS: Acute and chronic bronchiolitis and peri-bronchiolitis are the essential pathological changes in COPD, and also are the key link of the structural remodeling of the pulmonary tissue and vessels.

Bronchi↗
PubMed1999

[Effect of hypoxia on proliferation and differentiation of the pulmonary vascular pericytes].

OBJECTIVE: To study the effect of hypoxia on proliferation and differentiation of the pulmonary vascular pericytes (PC). METHODS: Cell culture, (3)H-thymidine incorporation ((3)H-TdR), immunocytochemistry and image analysis methods were used. RESULTS: It was found that the (3)H-thymidine incorporation, the expression amounts of proliferating cell nuclear antigen (PCNA) and alpha-smooth muscle actin (alpha-SM-Actin) in direct hypoxia (H) group was 2.16 times (P < 0.01), 1.16 times(P < 0.01) and 1.11 times (P < 0.05) that of normoxia (N) group, in hypoxic endothelial cell conditioned medium (HECCM) group was 1.8 times (P < 0.01), 1.15 times (P < 0.01) and 1.12 times (P < 0.05) that of normoxic endothelial cell conditioned medium (NECCM) group. CONCLUSIONS: It was suggested that hypoxia can stimulate pulmonary artery endothelial cells (PAEC) to secrete some growth factors to enhance PC proliferation and transformation of smooth muscle-like cells.

Actins↗
PubMed1999

[The effects of hypoxia on vascular pericytes of the lung].

OBJECTIVE: To study the effects of hypoxia, directly or mediated by pulmonary arterial endothelial cells, on energy metabolism, cell cycle, platelet derived growth factor (PDGF) and PDGF receptor mRNA expression of vascular pericytes of the lung in vitro. METHODS: Use of MTT colorimetric assay, flow cytometry, nucleic acid in situ hybridization and automatic image analysis for quantitative analysis. RESULTS: Hypoxia promoted vascular pericyte proliferation directly or through the mediation of endothelial cells to promote vascular pericyte proliferation from static phase (G(0), G(1) phase) to DNA synthesis phase (S phase) and mitotic phase (G(2) + M phase) and upregulate gene expression of PDGF and PDGF-R by vascular pericyte of the lung. CONCLUSIONS: The low oxygen tension of alveolar gas and hypoxemia may promote transcription of PDGF and its receptor gene. Paracrine and autocrine PDGF may induce proliferation of vascular pericytes of the pulmonary vessels and may play a role in pulmonary hypertension and structural remodeling of the pulmonary vessels, especially in the neomuscularization of nonmuscular pulmonary arterioles.

Animals↗
PubMed1998

The expression of PDGF-B chain mRNA in lung tissue from rats repeatedly infected with mycoplasma pneumoniae.

In order to investigate the role played by platelet derived growth factor-BB (PDGF-BB) in the pathogenesis of pulmonary interstitial fibrosis in rats repeatedly infected with mycoplasma pneumoniae (MP), a rat MP infection model was developed by infecting rats with MP for 9 times during a period of 24 weeks with a technique of ultrasonic nebulizing inhalation. Then in situ hybridization was performed with PDGF-B chain cDNA probe and the results were quantitatively analyzed to measure the changes in PDGF-B chain mRNA expression in the lung tissue. The results showed that: (1) MP polymerase chain reaction (PCR) tests showed positive results in the bronchoalveolar lavage fluid (BALF) from all of the MP-infected rats (n = 4) while they were all negative in BALF from the control animals (n = 4, P < 0.05) and in BALF from those rats both infected with MP and, at the same time, treated with erythromycin (n = 4, P < 0.05). Bacterial cultures of the bronchial and lung tissue were negative in all three groups. The observation under a transmission electron microscope indicated that the interalveolar septa were widened with increased amount of collagen in the MP-infected rats while there were no obvious abnormalities in the other two groups. (2) Strong positive expression of PDGF-B chain mRNA was found in the plasma of monocytes and macrophages located in the locally widened interalveolar septa and alveolar spaces in the lung tissue from the MP-infected animals with the integral optical densities being 37.42 +/- 9.05 (n = 4) which was significantly higher than the values of control group (0.42 +/- 0.08, n = 4, P < 0.01) and of the group with MP-infection plus erythromycin treatment (1.62 +/- 0.40, n = 4, P < 0.01). These results suggest that PDGF-BB may be involved in the process of the development of pulmonary interstitial fibrosis caused by the repeated MP-infection. It may be an important growth factor for mediating the roles of monocytes and macrophages to promote the aggregation and proliferation of fibroblasts which can then secrete collagen in large quantity in the pulmonary interstitium.

Animals↗
PubMed1998

[Platelet-derived growth factor (PDGF) mRNA expression of porcine pulmonary artery smooth muscle cells induced by hypoxic endothelial cells conditioned medium].

OBJECTIVE: To study the effect of hypoxic endothelial cell conditioned medium on the autocrine of PDGF in porcine pulmonary artery smooth muscle cells (PASMC). METHODS: Experimental groups included serum-free medium group (control group), normoxic endothelial cell conditioned medium (NECCM) group and hypoxic endothelial cell conditioned medium (HECCM) group. The expression of PDGF-A and -B chain mRNA was determined by in situ hybridization and image analysis. RESULTS: A weak expression for PDGF-A and PDGF-B mRNA was observed in PASMC cultured in serum free medium (control group); HECCM markedly enhanced the expression of PDGF-A and PDGF-B mRNA in PASMC, both being about 1.8-fold and 1.73-fold of the control group respectively, and 1.4-fold and 1.5-fold of the NECCM group respectively (P < 0.01). CONCLUSION: PDGF may be an autocrine growth factor of PASMC induced by HECCM and may play an important role in vascular structural remodeling of hypoxic pulmonary hypertension.

Animals↗
PubMed1997

Photostimulation with caged neurotransmitters using fiber optic lightguides.

'Caged' neurotransmitters are molecules that are transformed to a neuroactive state by exposure to light of an appropriate wavelength and intensity. Use of these substances has centered on in vitro bath application and subsequent activation using light from lasers or flashlamps that is delivered into the preparation through microscope optics. We have tested a new and simpler method, using finely tapered fiberoptic lightguides, that promises to expand the use of caged compounds for in vitro and in vivo experimentation. We demonstrated the feasibility and flexibility of this method for caged neurotransmitter delivery using a range of ex vitro, in vitro and in vivo approaches. The degree and timing of uncaging could be controlled by manipulating the wavelength, intensity and timing of the light projected into the optical fiber. Because of the small size of the light guide and the ability to control light exposure at the source, this new method promises greater control over the spatial and temporal delivery of neuroactive substances than simple bath or iontophoretic application, and enables delivery of conventional neurotransmitters with a spatial and temporal resolution closer to that of the natural neuronal circuitry. In addition, this new method allows the application of normally labile substances, such as the free radical gas nitric oxide, by the photoconversion of photosensitive precursors.

Animals↗
PubMed1997

Effects of the medium conditioned by endothelial cells under hypoxic condition on the phenotype of porcine pulmonary arterial smooth muscle cells.

The effects of the medium conditioned by endothelial cells under hypoxic condition on the phenotype modulation of pulmonary artery smooth muscle cells (PASMCs) were investigated by using cell culture and morphometrical analysis. The results showed that the number of diploid cells and alpha-sm-actin of PASMCs in the hypoxic endothelial cell conditioned medium group (HECCM) was lower and the myofibrilles were even less than that in normal endothelial cell conditioned medium group (NECCM). On the contrary, the volume density of rough endoplasmic reticulum (RER) and mitochondria of PASMCs in the HECCM group was higher than that in the NECCM group, i.e. altering from a contractile type to a synthetic type. However, under direct hypoxic condition for 24 h, the phenotype of cultured PASMCs remained unchanged, i.e. retained contractile type. It suggests that the HECCM can induce phenotype modulation of PASMCs, may be mediated by the pulmonary artery endothelial cells (PAECs) which can secrete some cytokins affecting the PASMCs.

Animals↗
PubMed1997

[Effects of hypoxia on the release of PDGF-B chain from pulmonary artery endothelial cells and on growth of pulmonary artery smooth muscle cells].

Platelet-derived growth factor (PDGF), content in hypoxic endothelial cells conditioned medium (HECCM) and normoxic endothelial cells conditioned medium (NECM) was determined using protein dot blot assay. The effects of HECCM and NECCM on the growth of pulmonary artery smooth muscle cells (PASMC) were assessed with [3H]-thymidine incorporation technique and flow cytometric analysis. PDGF content in HECCM was higher than that in NECCM. HECCM dramatically enhanced the DNA synthesis in PASMC and significantly promoted the cell cycle progression of PASMC from G0/G1 phase to S phase. In addition, administration of anti-PDGF-B chain monoclonal antibodies blocked markedly the DNA synthesis of PASMC stimulated by HECCM and obviously inhibited the entry of the cells from G0/G1 phase to S phase. These results suggest that increased PDGF release from pulmonary artery endothelial cells under hypoxia could stimulate the proliferation of PASMC which may induce pulmonary vascular reconstruction and involve in the development of hypoxic pulmonary hypertension.

Animals↗