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Biomedical subjects

M Zhao

Publications and source records attributed to M Zhao.

At least 163 records · Page 9Linked to original sources
PubMed1999

Modelling corneal epithelial wound closure in the presence of physiological electric fields via a moving boundary formalism.

A new framework for the modelling of corneal epithelial wound healing is presented, which can include the presence of a physiological electric field. The difficulty inherent in the inclusion of this biological phenomenon motivates our use of a moving boundary formalism. A key conclusion is that the model predicts a linear relation between the wound healing speed and the physiological electric field strengths over a physiologically large range of electric field strength. Another key point is that this linear relationship between electric field strength and wound healing speed is robust to variations in critical parameters that are difficult to estimate. The linearity is also robust to different realizations of the modelling framework presented.

Animals↗
PubMed1999

[Clinical use of the prefabricated expanded island skin flap].

OBJECTIVE: This is to introduce the applications of the prefabricated expanded island skin flap based on a fasciovascular pedicle. METHODS: The superficial temporal vessel was transferred to the cervical region and an expander was buried under it. When the expander was fully expanded, an island skin flap was elevated and transferred based on the fasciovascular pedicle. Eight patients were treated with this method since 1996. RESULTS: All the flaps survived without necrosis. CONCLUSION: The island skin flap prefabricated in this manner has rich blood supply and can be transferred safely. It is useful in plastic and reconstructive surgery, especially for the severe burned patients whose normal skin is insufficient.

Adult↗
PubMed1999

[Comparative study on early revascularization of membranous and endochondral onlay bone grafts in the rat].

OBJECTIVE: To investigate the disparity in early revascularization of the membranous and endochondral bone grafts. METHODS: Twenty Wistar rats were randomly divided into two groups of 10 each. Full-thickness cranial (membranous) and split-thickness iliac crest (endochondral) onlay bone grafts were placed subperiosteally onto the snout of the animal without bony fixation. At 7 and 14 days after grafting the bone grafts together with the recipient sites were harvested. Revascularization was studied utilizing opacifying injection and computerized image analysis technique. RESULTS: The extent of vascularization at 7 days was 11.88% and 22.33% in membranous and endochondral bone grafts, respectively, and they developed to be 15.93% and 34.93% at 14 days, respectively. CONCLUSION: The results indicated that endochondral bone grafts were more rapidly revascularized than membranous bone grafts at 7 and 14 days (P < 0.05). Differences in graft architecture are theorized to account for the relationship between the vascularization and volume maintenance in the bones of different embryonic origin.

Animals↗
PubMed1999

Immunological studies on the cellular phenotype involved in corneal allograft rejection.

OBJECTIVE: To investigate the cellular phenotype involved in corneal allograft rejection using wholemounts analysis. METHODS: Corneal transplantation was performed between Sprague Dawley (SD) and Wistar rats. Corneal wholemounts were prepared from control rats and those after corneal transplantation on day 7 and 12. Immunohistochemical stain was performed on these wholemounts using monoclonal antibodies to transforming growth factor beta 1(TGF-beta 1), CD3, CD4, CD8, B lymphocytes, macrophages, dendritic cells and major histocompatibility complex (MHC) class II antigen. RESULTS: Corneal allograft rejection started on day 7 and reached its maximum from 10 to 14 days after corneal transplantation. Presence of TGF-beta 1-, CD3-, CD4-, CD8-, MHC class II-positive cells, macrophages and dendritic cells were noted at the limbus of both SD rats and Wistar rats. No positive cell was present in the central cornea of normal rats. All positive cells but B lymphocyte were noted in large numbers in the cornea after corneal allograft transplantation. Marked staining for TGF-beta 1 was noted during graft rejection. CONCLUSION: The corneal wholemounts technique provides a good visualization for the cellular phenotype involved in corneal allograft rejection. A variety of cells including TGF-beta 1, CD3, CD4, CD8, MHC class II antigen positive cells, macrophages and dendritic cells are involved in corneal allograft rejection. TGF-beta 1-positive cell might be an important immunosuppressive factor after corneal transplantation and also involved in the induction of fibrosis.

Animals↗
PubMed1999

[Histological study and stereologic analysis of membranous versus endochondral onlay bone grafts].

OBJECTIVE: The experimental study was to determine the differences in changes in the onlay bone grafts of different embryonic origin. METHODS: The study was designed to compare the potential for appositional bone growth in membranous and endochondral onlay grafts in New-Zealand rabbits and a rhesus monkey. Results were assessed with volumetric measurement, histological examinations and stereologic analysis with double-fluorochrome labeling technique. RESULTS: For the membranous and endochondral bone grafts, the volumetric retention rate was (78.4 +/- 3.5)% and (56.0 +/- 5.1)% respectively. The mineralization apposition rate (MAR) was (3.6 +/- 0.8) microns/d and (0.92 +/- 0.33) micron/d; the osteoid seam width (OSW) was (14.56 +/- 2.69) microns and (7.38 +/- 2.20) microns; the tetracycline uptake rate(TUA) was (91.22 +/- 2.69)% and (51.28 +/- 4.11)%, respectively. CONCLUSION: 1. It was found that the membranous bone graft maintained its volume to a significantly greater extent than the endochondral bone graft; 2. Membranous bone grafts exhibited higher survival rate and greater activity than endochondral bone grafts; 3. Different changes were also found in the two recipient sites. There was more powerful bone regenerative reaction in the recipient bed of the membranous bone graft than the endochondral one.

Animals↗
PubMed1999

[The significance of antiendothelial cell antibodies in patients with lupus nephritis: a clinical and renal pathological study].

OBJECTIVE: To investigate the prevalence and possible role of antiendothelial cell antibodies (AECA) in the pathogenesis of lupus nephritis. METHODS: Sera from 58 patients with lupus nephritis were studied. Cellular ELISA were used to detect AECA, and immunoblotting was performed to determine specific endothelial target. RESULTS: 36% of the patients with lupus nephritis had elevated IgG-AECA. IgG-AECA was correlated with the higher incidence of thrombocytopenia, higher serum immuoglobulin G levels, lower serum C3(13 +/- 7) g/L and higher titers of antibodies against nucli and dsDNA. AECA consisted of a group of heterogeneous antibodies and reacted with different endothelial cell antigens ranging from 12,000 to 90,000 in molecular size. A correlation was demonstrated between heavy proteinuria (> 3.5 g/24 hr) and the existence of antibodies simultaneously against the 27,000, 29,000 endothelial cell antigens (34% vs 4%), we also found an association between the presence of glomerular capillary thrombi and antibody against the 29,000 endothelial cell antigen (60% vs 14%). CONCLUSION: These results suggested that lupus nephritis patients with AECA showed a complex autoimmune disorder and provided an indirect evidence that AECA might contribute to the pathogenesis of lupus nephritis.

Adult↗
PubMed1999

The significance of anti-endothelial cell antibodies in patients with lupus nephritis and immunoblotting analysis of the target components.

OBJECTIVE: To investigate the prevalence of anti-endothelial cell antibodies and its possible role in the pathogenesis in lupus nephritis. METHODS: Sera from 58 patients with lupus nephritis were studied. Cellular enzyme linked immunoabsaborbent assay was used to detect anti-endothelial cell antibodies, and immunoblotting technique was performed to determine its specific endothelial target antigens. RESULTS: 36.2% of the patients with lupus nephritis had elevated IgG isotype anti-endothelial cell antibodies. The association was revealed between the presence of anti-endothelial cell antibodies (AECA) and some laboratory and renal biopsy features, such as thrombocytopenia, higher serum IgG level, lower serum C3 level, higher erythrocyte sedimentation rate (ESR), presence of anti-nuclear antibody (ANA), anti-dsDNA antibodies and glomerular thrombosis. Anti-endothelial cell antibodies were consisted of a group of heterogeneous antibodies, and reacted with different endothelial cell antigens which ranged from 12-90 kD in molecular size in immunoblot. A correlation was demonstrated between heavy proteinuria (> 3.5 g/24 hr) and the existence of antibodies against both 27 and 29 kD endothelial cell antigens, an association between the presence of glomerular capillary thrombi and antibody against the 29 kD endothelial cell antigen was also found. CONCLUSIONS: Lupus nephritis patients with anti-endothelial cell antibodies showed a complex autoimmune disorder and clinical disease activity, and the results also provided an indirect evidence that anti-endothelial cell antibodies might contribute to the pathogenesis of lupus nephritis.

Autoantibodies↗
PubMed1999

[Analysis of instability and deletion on chromosome 3p14 in Peutz-Jeghers syndrome].

OBJECTIVE: To determine the region where the tumor susceptible genes located, and to study chromosome instability, deletion and rearrangement of genes in Peutz-Jeghers Syndrome. METHODS: The method of induction was used to detect chromosome fragile sites of patients, Who were contrasted to familiar members and healthy individuals. DNA was extracted from leukocyte, polypus and tumor tissues, fresh or embedded in paraffin. The highly frequent abnormality of chromosome 3p14 region was studied with PCR, PCR-SSCP, microsatellite analysis, and DNA sequencing. RESULTS: The highest frequency of fragile site was in chromosome 3p14-3p24 region. The aberration frequency of D3S3340 is 21.4%, and that of D3S30 is 14.3%. Microsatellite analysis demonstrated LOH, of which the frequency is 42.9%; in addition, APC, k-ras mutation also occurred. The loss of guanylic acid was found in D3S1766. CONCLUSION: PJS has high chromosome instability, with deletion, mutation and arrangement of genes in 3p14 region, suggesting that cancer susceptible genes would be harbed in 3p14 cloning.

Adolescent↗
PubMed1999

[Changes of calcitonin gene-related peptide content in induced sputum from patients with COPD and asthma].

OBJECTIVE: To explore the role of sensory neuropeptide calcitonin gene-related peptide (CGRP) in the pathogenesis of chronic airway inflammatory diseases COPD and bronchial asthma. METHODS: Patients with COPD (n = 19), bronchial asthma (n = 14), all were in stable stage and 10 normal volunteers were examined. After hypertonic saline inhalation challenge in all subjects, CGRP-LI concentration in the induced sputum was measured by radioimmunoassay. Cellular content was assayed by microscopic analysis, the relation between CGRP-LI level and FEV1 value was calculated by linear regression. RESULTS: The sputum CGRP concentrations in patients with COPD and patients with asthma were (15.97 +/- 2.15) ng/L, (18.79 +/- 3.91) ng/L, respectively, both were significantly higher than those in normal volunteers (2.36 +/- 0.35) ng/L. Moreover, CGRP concentrations in induced sputum in each disease group were correlated with the degree of airflow obstruction, r = -0.50 and -0.61, respectively (P < 0.05). The percentage of neutrophil cell count (64.9 +/- 2.9)% was significantly higher in patients with COPD (P < 0.01), while the percentage of eosinophil cell count (5.8 +/- 0.5)% was increased in patients with asthma (P < 0.01). CONCLUSIONS: The data suggested that CGRP release may participate in the chronic inflammation of patients with COPD and bronchial asthma.

Aged↗
PubMed1999

[Expression of heat shock protein 90 alpha and its effect on the growth of tumor in mice].

OBJECTIVE: To study the effect of hsp90 alpha on the growth of tumor in mice and its mechanism. METHODS: Hsp90 alpha fusion protein was expressed in E. coli. DBA/2 mice were injected with purified fusion protein, then challenged with L1210 cells. The size of tumor was measured every other day. NK cell activity was detected by 51Cr release assay. RESULTS: The tumors grew faster while activity NK cell activity of mice was lower in the test mice than that in the control mice. CONCLUSION: The results suggest that the accelerated tumor growth is probably due to the formation of anti-hsp90 alpha antibody and decreased NK cell activity of mice treated with hsp90 alpha.

Animals↗
PubMed1999

[The serum bactericidal activity of domestic fleroxacin and lomefloxacin].

OBJECTIVE: To evaluate antibacterial activities in vivo and in vitro of fleroxacin and lomefloxacin. METHODS: Minimal inhibitory concentration (MIC) and serum bactericidal activity (SBA) domestic fleroxacin and lomefloxacin were determined by agar disk dilution method and microplate method respectively. A clinical observation of fleroxacin and lomefloxacin for treating acute bacillary dysentery was carried out. RESULTS: MIC(90) of fleroxacin against E. coli, K. pneumoniae, S. dysenteriae, S. aureus was 0.25-2 mg/L, being the same as that of ofloxacin. However, MIC(90) of lomefloxacin against the above mentioned species was twice or fourfold as that of ofloxacin and fleroxacin. The percent age of peak SBA > or = 1:8 with ofloxacin, fleroxacin and lomefloxacin against E. coli, K. pneumoniae, S. dysenteriae was 80%-100%, 90%-100% and 50%-80% respectively (P < 0.01). The clinical cure rates of acute bacillary dysentery were 93.3%, 100% and 100% and the bacterial clearance rates were 93.3%, 100% and 100% in the lomefloxacin, fleroxacin and ofloxacin group respectively. CONCLUSION: The antibacterial activity in vivo and in vitro of fleroxacin against E. coli, K. pneumoniae, S. dysenteriae was similar to that of ofloxacin and stronger than that of lomefloxacin.

Anti-Infective Agents↗
PubMed1999

[The diagnostic significance of antineutrophil cytoplasmic antibodies in ulcerative colitis].

OBJECTIVE: To inquire into the diagnostic significance of antineutrophil cytoplasmic antibodies (ANCA) in ulcerative colitis (UC). METHODS: Serum ANCA from 58 UC patients, 43 non-UC patients and 58 healthy donors were detected with indirect immunofluorescence (IIF), enzyme linked immunosorbent assay (ELISA)and Western blot. RESULTS: The sensitivity and specificity of the presence of ANCA in the diagnosis of UC were 37.93% and 100% respectively. In the group of UC, patients with mild, moderate and severe clinical manifestations had positive ANCA rates of 17.65%, 41.67% and 52.94% respectively. The occurrence rates of mucosal vasculitis and grade III-V mucosal inflammation were 78.95% and 78.95% respectively in ANCA-positive group, but 37.04% and 44.44% in ANCA-negative group. The levels of the binding of the five kinds of ANCA antigens i.e. myeloperoxidase (MPO), bactericidal/permeability increasing protein (BPI), lactoferrin (LF), cathepsin G (CG) and proteinase-3 (PR-3) with the serum of UC patients were 13.99%, 13.79%, 10.34% 10.34% and 8.62% respectively. Specific protein strips were observed in 48.28% of the UC patients with Western blot technique, 47,000 polypeptide being the most common and making up 22.41% of them. CONCLUSION: The detection of ANCA was an auxiliary method for the diagnosis of UC. At present, UC-associated target antigens were not yet clarified, 47,000 polypeptide may be one of them. ANCA may participate in the pathogenesis of UC.

Adolescent↗
PubMed1999

[Changes of apoptosis and Fas gene expression in cardiomyocytes of rats with myocardial reperfusion and the effects of ischemic preconditioning].

OBJECTIVE: To study the changes of apoptosis and Fas gene expression in cardiomyocytes of rats with different duration of reperfusion after myocardial ischemia and the effects of ischemic preconditioning (IPC). METHODS: 108 rats were divided randomly into 6 groups, i.e. sham-operated (observing for 24h in operated control), 30min of ischemia followed by 6h of reperfusion(I(30 min) R(6h)), I(30min)R(12h), I(30min)R(24h), I(30min)R(48h) and IPC. The myocardial cell apoptosis was determined with terminal deoxynucleotidyl transferase-mediated dUTP-fluorescein nick end labeling (TUNEL) method; The protein and mRNA expression of Fas gene were studied with S-P immunohistochemical staining and RT-PCR analysis respectively. RESULTS: Cardiomyocyte apoptosis and the level of Fas gene expression varied with the duration of reperfusion. The apoptotic index (AI) and protein expression index (PEI) of Fas gene in myocytes were highest in rats with I(30min)R(48h) [AI: (38.15 +/- 13.26)%; Fas PEI: (24.77 +/- 12.92)%], but mRNA induction peaked at I(30min)R(24h) (Fas/beta-actin: 0.76 +/- 0.21); PEI of Fas gene correlated significantly with AI of myocytes (r = 0.87, P < 0.01); IPC decreased myocyte apoptosis and down-regulated the protein expression of Fas gene (all P < 0.05). CONCLUSION: The number of apoptotic myocytes and the expression level of Fas gene varied with different duration of myocardial reperfusion. The change of apoptosis and Fas gene expression may be involved in the process of myocardial ischemia reperfusion injury. IPC prevent myocardial injury partly by inhibiting myocyte apoptosis and down-regulating protein expression of Fas gene.

Animals↗
PubMed1999

[The effects of inhaled bronchodilators on central inspiratory drive in patients with COPD].

OBJECTIVE: To evaluate the effects of inhaled bronchodilators on the central inspiratory drive in patients with COPD. METHODS: 91 patients with COPD were divided into three groups (A, B, C) randomly. Lung functions and P(0.1) were measured at baseline and 20 min and 60 min after inhalation (A: albuterol; B: iprotropium; C: albuterol + iprotropium). RESULTS: P(0.1) decreased after inhalation in all three groups (P < 0.05 approximately 0.001). A positive correlation between DeltaP(0.1) and DeltaFRC was found in the three groups (r = 0.4325 - 0.5230, P < 0.05 approximately 0.01). V(E)/P(0.1) increased in the three groups after inhalation (P < 0.05 approximately 0.005). There was significant improvement of V(E)/P(0.1) in group B and C as compared with that of group A (P < 0.05, P < 0.001); There was a different correlative factor with V(E)/P(0.1) in group B and C. CONCLUSIONS: (1) P(0.1) decreased after inhalation, It may be caused by decreased FRC. (2) V(E)/P(0.1) became appropriate after inhalation in all groups; The improvement in group B and C was superior to that of group A. There may be different mechanisms to improve V(E)/P(0.1) by different inhalators.

Administration, Inhalation↗
PubMed1999

[A clinical study of bacterial infection in patients with chronic obstructive pulmonary disease].

OBJECTIVE: To investigate the association of bacteriologic characteristics and bacterial infection in small airway disease. METHODS: Fiberoptic bronchoscopy and ultrathin fiberoptic bronchoscopy were performed on outpatients with COPD and chronic bronchitis both during stable stage and acute exacerbation. Samples were obtained from both large and small airways by protective specimen brush, and bacteria were cultured quantitatively. RESULTS: The positive rates for pathogens in patients with COPD and chronic bronchitis during acute exacerbation were 26.6% (8/30) and 23.5% (5/17) respectively. Major pathogens in acute COPD include Staphylococcus aureus, Streptococcus pneumoniae, Hemophilus influenzae, Moraxella catarrhalis, and Pseudomonas aeruginosa. All of the pathogens were present in large airways, with 2 strains present in small airways concurrently. The positive rates for pathogens in stable COPD and chronic bronchitis were 24.0% (6/24) and 11.7% (2/17) respectively. Major pathogens found in stable COPD include Staphylococcus epidermis, Micrococcus and Streptococcus pneumoniae. The bacteria were less than 10 x 10(3) cfu/ml, present mainly in large airways. There was no significant difference in the extent of small airway diseases between COPD with bacterial infection and that without bacterial infection (P > 0.05). CONCLUSIONS: Bacterial infection is not a major pathogenic factor in stable COPD. There is no direct cause-and-effect relationship between bacterial infection and the extent of small airway diseases in patients with COPD.

Adult↗
PubMed1999

[The effect of inhaled ipratropium bromide on airway and lung tissue muscarinic receptors in a rat model of COPD].

OBJECTIVE: To observe the effect of inhaled ipratropium bromide on airway and lung tissue muscarinic receptors (MR) in a rat model of chronic obstructive pulmonary disease (COPD). METHODS: The rat model of COPD was established by chronic exposure with high concentrations of SO(2) gas, COPD rats inhaled aerosolized 0.025% ipratropium bromide solution 10 ml (twice/d, 20min/time). The MR was determined by radioligand binding studies with (3)H-QNB as the ligand. RESULTS: Compared with that of control, there was a marked increase in MR density on day 30 of treatment with ipratropium but not on day 5. The MR density decreased and close to normal level on the 6th day after cessation of regular therapy with inhaled ipratropium for 30 days. No significant difference was observed in antagonist affinity (Kd) among different time groups of ipratropium therapy. CONCLUSIONS: Chronic exposure to the anticholinergic agent ipratropium bromide produces an up-regulation of airway MR. The airway MR density can recover to normal when treatment stopped. Up-regulation of airway MR is associated with transient bronchoconstriction following cessation of regular ipratropium therapy and lung function deteriorated following long-term inhaled ipratropium bromide.

Administration, Inhalation↗