Biomedical subjects

M Zhao

Publications and source records attributed to M Zhao.

At least 199 records · Page 11Linked to original sources

PubMed1998

Immunohistochemical demonstration of bone morphogenetic protein-2 and type II collagen in pleomorphic adenoma of salivary glands.

Immunohistochemical investigation of bone morphogenetic protein-2 (BMP-2) and type II collagen, two cartilage-associated proteins, was undertaken using monoclonal antibodies in 20 cases of salivary pleomorphic adenoma (PA) in order to explore their possible roles in chondroid differentiation of this tumor. Other salivary gland tumors, including adenoid cystic carcinoma (17 cases), polymorphous low-grade adenocarcinoma (10 cases), basal cell adenoma (3 cases), basal cell adenocarcinoma (1 case), and epithelial-myoepithelial carcinoma (2 cases), were also examined for comparison. In PA, BMP-2 immunoreactivity was detected in the luminal and non-luminal cells of the tubulo-ductal structures, plasmacytoid cells, and other scattered tumor cells in solid areas. In addition, tumor cells in chondroid areas in most cases (14/15), and stellate cells in myxoid areas in many cases (7/19), were also intensely labeled for BMP-2. Furthermore, BMP-2 was also detected in the non-neoplastic ductal cells in salivary glands, whereas no other salivary gland tumors were positively stained for this protein. Type II collagen was localized in the intercellular matrix of chondroid areas and in a few chondroid differentiating cells in myxoid areas, confirming its cartilage-specificity. A proportional relationship was observed between BMP-2 expression and chondroid formation, although BMP-2 was also stained in occasional PAs without chondroid formation. It is speculated that BMP-2 might be secreted by tumor cells and play a role in chondroid formation in PA by inducing some tumor cells to produce type II collagen and other chondroid matrical substances, like glycosaminoglycans. The expression of BMP-2 is specific to PA and may possibly be used as a useful marker in differentiating PA from other salivary gland tumors.

Adenocarcinoma↗

PubMed1998

Liver cell dysplasia: reactivities for c-met protein, Rb protein, E-cadherin and transforming growth factor-beta 1 in comparison with hepatocellular carcinoma.

In the present retrospective study, liver cell dysplasia (LCD) occurring in cirrhotic livers associated or not associated with hepatocellular carcinoma (HCC) was immunohistochemically analyzed for the expression of hepatocyte growth factor receptor (c-met protein), Rb (retinoblastoma gene) protein, E-cadherin, and transforming growth factor-beta-1 (TGF-beta-1). Cytoplasmic c-met protein staining was observed in about half of the HCC's, and its prevalence was about twice as high in high grade vs. low grade tumors, but it was not correlated with proliferative activity as based on PCNA labelling. In LCD, reactivity for c-met protein was restricted to the small cell type. Nuclear staining for Rb protein was found in HCC's, and was not related to type, grade or proliferative activity, whereas no immunoreactivity was observed in normal, hyperplastic or dysplastic hepatocytes. Expression of E-cadherin prevailed in HCC's of lower grade, and particularly in those with a trabecular or acinar growth pattern. E-cadherin staining was detectable in normal and large dysplastic hepatocytes, but not in small dysplastic liver cells. TGF-beta-1 reactivity was observed in more than half the HCC's, but not in normal or dysplastic hepatocytes. These findings underline the phenotypic difference between large cell and small cell liver dysplasia, and support the hypothesis that small cell dysplasia is a precursor lesion in a hepatocarcinogenic pathway.

Cadherins↗

PubMed1998

[Applied anatomy of the temporal and frontal regions in endoscopic temporal lifting].

OBJECTIVE: This anatomic study was carried out in a bid to decrease damage of the temporal branch of the face nerve in endoscopic temporal lifting. METHODS: We dissected the frontal-temporal region and located the temporal branch on 36 sides of adult head specimens. RESULTS: It was found that the temporal branch is deep to the temporoparietal fascia and frontal muscle. The temporal branch has one to four branches in general. The first one is 8.1 +/- 2.1 mm anterior to articular tubercle and 33.8 +/- 4.9 mm superior to the bony lateral canthus. The temporal branches locate below a line drawn from the articular tubercle to 40 mm above the bony lateral canthus. CONCLUSION: It is suggested that the operation incisions in the temporal region be selected above this line.

Adult↗

PubMed1998

An experimental study on rhBMP-2 composite bone substitute for repairing craniomaxillary bone defects.

OBJECTIVE: To measure bone regenerative effects in animal calvarial or mandibular critical-size defects using recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with four selected carriers. MATERIALS AND METHODS: The composite bone grafts were obtained by combining rhBMP-2 with chitin, coral, coral-based porous HA (CHA), and xenogeneic cancellous bone, respectively. These materials were implanted on the calvarial or mandibular defect of rabbits and on the calvarial defect of rats. Each carrier material was also studied as a control group. The animals were examined 2, 4, 8, and 12 weeks after implantation by radiography, histology (under light microscope and scanning electron microscope), immunohistochemistry, and biomechanics. RESULTS: The results showed that the composite graft was absorbed gradually after it was implanted into the defect, during which time new bone was formed within the combined material in the defect site; the amount of new bone increased as time elapsed. At 12 weeks the composite was replaced completely by bone except in the CHA group. In contrast, a large amount of fibrous tissue, and little new bone, formed on the area of the bone defect when the carrier material alone was implanted. CONCLUSIONS: All materials tested seem to be suitable carriers for rhBMP-2, which plays a very important role in new bone formation. These composite bone substitutes may be ideal materials for repairing various bone defects in the craniomaxillofacial region.

Animals↗

PubMed1998

[Immunoprotection in guinea pigs using DNA recombinant plasmid rpDJt and expressed protein P68 in L. interrogans serovar lai].

Immunoprotection against the infection by Leptospira interrogans serogroup Icterohemorrhagiae serovar lai strain 017 was demonstrated in guinea pigs vaccinated with DNA recombinant plasmid rpDJt and expressed protein P68 derived from genomic library of Leptospira strain 017. Thirty days after active immunization, each group received intraperitoneally (1/2 dose) and subcutaneously (1/2 dose) inoculum of L. interrogans serovar lai stain 017; cultures were adjusted to 5 x 10(8) cells/ml. All guinea pigs were observed for 10 days after challenge. Survival (%) of P68 group was 100(7/7); P23 group was 75(3/4); group rpDJt was 77(10/13); group lack recombinant (control) pT7-7 was 25 (3/12), and group with whole-cell inactivated vaccine was 93(13/14). Although the protective antigen in the leptospires has yet to be determined, it is evident that expressed protein P68 conferred a high degree of immunoprotection in guinea pigs.

Animals↗

PubMed1998

[An immunohistochemical study of the proliferating activity of ameloblastic fibroma and ameloblastic fibrosarcoma].

Six cases of ameloblastic fibroma (AF) and three cases of ameloblastic fibrosarcoma (AFS) were immunohistochemically investigated with a proliferating cell nuclear antigen (PCNA) monoclone antibody. Data on the PCNA labeling index (LI) of both epithelial and mesenchymal components were analyzed. The results showed that the PCNA LI of mesenchymal component of AFS (40.8%) was significantly higher than that of AF (3.2%) (P < 0.01) and that of the epithelial component of AFS (5.3%) was significantly lower than that of the mesenchymal one of AFS (P < 0.01). The results suggested that PCNA LI be a useful marker for the differentiation diagnosis of AF and AFS.

Cell Division↗

PubMed1998

[Comparative study of expression levels of the major human heat shock proteins in cancer and normal tissues].

OBJECTIVE: To investigate and compare mRNA expression levels of the major human HSPs (including HSP90 alpha, HSP90 beta, HSP70, HSC70 and HSP27) in 25 cases of laryngeal carcinomas and normal controls. METHODS: mRNA slot blot hybridization technique was used and cDNA probes of HSP27, HSC70 and HSP90 beta were prepared with PCR method. RESULTS: HSP90 alpha and HSP70 expression was significantly enhanced approximately 5 fold in laryngeal cancer tissues compared to that in the normal larynx tissues while HSP27, HSC70 and HSP90 beta expression was at similar levels. CONCLUSION: The results suggest that HSP90 alpha and HSP70 may play more important role in the carcinogenic process of laryngeal cancer. To find out mechanisms involved will pave the way for the application of HSPs on the biologic therapy of laryngeal cancer.

Adult↗

PubMed1998

[Effect of recombinant human FLT3 ligand (rhFL) on in vitro expansion of human cord blood CD34+ cells].

OBJECTIVE: To determine the effects of recombinant human FLT3 ligand (rhFL) on in vitro expansion of human cord blood CD34+ cells. METHODS: Human cord blood CD34+ cells were enriched by using a magnetic cell isolation system. CD34+ cells were incubated in liquid culture in the presence of different cytokines. The total number of all cells and the number of CD34+ cells and hematopoietic progenitor cells (CFU-GM and BFU-E) were counted at various time intervals. RESULTS: Human cord blood CD34+ cells could be enriched to the purity of more than 80%. The number of CD34+ cells increased 3.4 folds in the presence of rhFL + IL3 + IL6 + GMCSF + EPO in seven days, while in the control group without rhFL, it increased 1.5 folds. The difference of the number of more matured hematopoietic progenitor cells in the CD34+ cell population between the control group and the rhFL group was not significant. CONCLUSION: Only the primitive hematopoietic progenitor cells are expanded by rhFL according to the results obtained in the exclusion method.

Antigens, CD34↗

PubMed1998

[ICAM-1 and HLA-DR expression in bronchial epithelial cells from patients with chronic obstructive pulmonary disease].

OBJECTIVE: To study the expression of adhesion molecules in epithelial cells from patients with COPD. METHOD: The expression of ICAM-1 and HLA-DR in airway epithelial cells from 10 COPD patients, 7 asthmatic patients, 9 chronic bronchitis patients, and 10 healthy volunteers was evaluated using immunohistochemistry techniques. The cells were stained and analysed microscopically. RESULT: The percentage of neutrophils in brushing cells from COPD(0.04) were significantly higher than those from asthma(0.01) and normal subjects (0.01). More goblet cells were found in COPD (mean 0.13) and chronic bronchitis (mean 0.11) as compared with asthma (0.03) and healthy volunteers. As to the expression of ICAM-1 in COPD, the percentage of cells expressing ICAM-1(15%) significantly increased in comparison with chronic bronchitis (6.28% P < 0.05), healthy volunteer(1.8%, P < 0.05), and asthma (8.8%, P > 0.05). The score of expression of ICAM-1 in COPD was significantly higher than those in asthma (P < 0.05), chronic bronchitis (P < 0.05) and normal subjects (P < 0.001). As to the expression of HLA-DR in COPD, the percentage of cells expressing HLA-DR(5.9%) significantly increased in comparison with normal subjects (0.6% P < 0.05), but there was no significant difference among COPD, asthma and chronic bronchitis. The score of expression of HLA-DR in COPD was significantly higher than those in healthy volunteers (P < 0.001), chronic bronchitis (P < 0.001) and asthma (P < 0.05). In addition, the percentage of neutrophils in brushing cells from COPD significantly correlated with the expression of ICAM-1 (r = 0.81, P < 0.01). CONCLUSION: Upregulation of ICAM-1 in epithelial cell from COPD correlates with the neutrophil infiltration in COPD. Lymphocytes are in an active state in COPD and the use of brush biopsies of the bronchial epithelium may serve as a diagnostic tool for differentiation among COPD, chronic bronchitis and asthma.

Adult↗

PubMed1998

[Spironolactone ameliorates rat pulmonary fibrosis induced by bleomycin A5].

OBJECTIVE: The purpose of this study was to investigate the role of aldosterone in pulmonary fibrosis and the protective effect of anti-aldosterone treatment. METHOD: Rats were divided into control, fibrosis and treatment groups; rat pulmonary fibrosis was induced by endotracheal injection of bleomycin A5 and spironolactone was given 100 mg/kg daily in drinking water to treatment group. 28 days later, plasma, bronchoalveolar lavage fluid(BALF) and tissue aldosterone concentration, as well as lung collagen levels, were determined. RESULT: Plasma aldosterone was higher in fibrosis group than that in control group(469 +/- 161 pg/ml and 319 +/- 115 pg/ml, respectively), but without significant difference (P > 0.05); spironolactone could ameliorate the extent of pulmonary fibrosis, the level of lung collagen was 25% less than that of fibrosis group (3.4 +/- 0.5 mg/g lung and 4.6 +/- 1.2 mg/g lung, respectively; q = 3.7893, P < 0.05), and the level of lung protein was 22% less (50 +/- 4 mg/g lung and 65 +/- 6 mg/g lung, respectively; P < 0.01). CONCLUSION: Spironolactone had some protective effects on pulmonary fibrosis, and aldosterone might play a role in the development of pulmonary fibrosis.

Aldosterone↗

PubMed1998

[Clinical study on relationship among Heart-Qi Deficiency, left ventricular function and myocardial ischemia in patients with coronary heart disease].

OBJECTIVE: To study the relationship among Heart-Qi Deficiency (HQD), left ventricular function and myocardial ischemia in patients with coronary heart disease (CHD). METHODS: Doppler echocardiogram, electrocardiogram were used to observe 103 patients of CHD clinically. Patients of stable angina pectoris treated with Radix Codonopsitis Pilosulae (50 cases) or Nifedipine (20 cases) were observed as well. RESULTS: Occurrence of left ventricular function insufficiency, both systolic and diastolic, was higher in CHD patients of HQD type as compared with that of non-HQD type. The left ventricular diastolic function showed high susceptibility (87%) and the left ventricular systolic function showed high specificity (88%) for HQD evaluation. Radix Codonopsitis Pilosulae could protect the left ventricular function and improve myocardial ischemia. CONCLUSIONS: Myocardial ischemia and blood stasis cause HQD, while the Chinese herbal medicine treatment on HQD could improve the blood stasis to alleviate myocardial ischemia effectively. The mechanism of which might be to enhance the positive diastolic and systolic function of cardiac muscles, reduce the resistance pressure and keep pressure of coronary perfusion so as to improve the blood supply of heart.

Aged↗

PubMed1998

[Expression of heat shock proteins in laryngeal carcinoma].

OBJECTIVE: To determine the expression of HSPs(HSP90 alpha, HSP90 beta, HSP70, HSP27) in laryngeal carcinoma and normal laryngeal mucosa. METHODS: Total RNA were extracted from 21 laryngeal cancer tissue samples and the normal mucosa of the corresponding larynx. The expression of HSPs mRNA was examined by Slot blot analysis. RESULTS: 1. HSP90 alpha and HSP70 were selectively overexpressed 5 times more in laryngeal carcinoma than in normal mucosa of larynx. 2. HSP90 beta and HSP27 were constitutively expressed at low level in these two groups. There was no significant difference between the levels of expression of HSP90 beta and HSP27 in laryngeal carcinoma and normal controls. CONCLUSION: The results that HSP90 alpha and HSP 70 mRNA were selectively overexpressed in laryngeal carcinoma suggested that HSP90 alpha and HSP70 might play a specific role in the pathogenesis of laryngeal cancer. To clarify the mechanism of HSPs action could help to provide theorical basis for the biological therapy of laryngeal cancer.

Adult↗

PubMed1998

[Corneal epithelium implantation under corneal flap after excimer laser in situ keratomileusis: a clinical pathological and cytological study and management].

OBJECTIVE: To study the clinical pathological and cytological characteristics of corneal epithelial cells implanted under the cap of laser in situ keratomileusis and the method of management. METHODS: For 4 eyes with epithelial cell implantation, the corneal cap was torn from temporal side to nasal, and the implanted material was removed from the flap and the stromal base. After washing between the interface, the cap was repositioned. RESULT: No epithelial implantation occurred again in these 4 cases after follow-up for 1 similar 12 months. The clinical pathological and cytological studies showed the material removed was degenerated and necrotic epithelial cells mixed with some unknown materials. CONCLUSION: Clinically, the material formed under the cap white and yellow in color should be removed as soon as it happens. The material consists mainly of non-structural material with necrotic and degenerated epithelial cells.

Cornea↗

PubMed1998

[A preliminary observation on vitrectomy combined with autologous platelet concentrate for the treatment of idiopathic macular holes].

OBJECTIVE: To investigate the efficacy of vitrectomy combined with autologous platelet concentrate for the treatment of idiopathic macular holes. METHODS: Fifteen eyes of 14 patients with idiopathic macular hole were treated. The follow-up period ranged from 3 to 16 months. Postoperatively, visual acuity, macular threshold, Amsler grid, fluorescein angiography (FA) and complications were evaluated. RESULTS: Of the fifteen eyes, the closure of the holes was achieved in 13 eyes (86.7%), visual acuity improved for two lines or more in 12 eyes (80.0%). The postoperative visual acuities in patients with abnormal Amsler grid were improved. No significant differences were found in the macular threshold (P = 0.34). Postoperative FA showed that the blocked fluorescence at the site of the macular hole which was surrounded by a hyperfluorescence ring (window defect) in three eyes. The intraoperative complication was primarily the retinal hole, and the postoperative complication was chiefly the aggravation of cataract. CONCLUSIONS: These results indicate that vitrectomy combined with autologous platelet concentrate can seal the macular hole well and improve the visual acuity in most patients. A large multicenter randomized prospective study and a longer period of follow-up are needed to verify these results.

Blood Transfusion, Autologous↗

PubMed1998

[Immunohistochemical studies on wholemounts of the cornea and iris-ciliary body after corneal transplantation].

OBJECTIVE: To study the phenotype of the cells involved in the pathogenesis of allograft rejection after corneal transplantation. METHODS: Wholemounts of the cornea and iris-ciliary body were isolated and prepared from normal rats and those after penetrating corneal transplantation. Immunohistochemical stainings were carried out on these wholemounts using monoclonal antibodies to CD3 (T cell), CD4 [T-helper (Th) cell], CD8 [T-suppressor (Ts) cell], macrophages, dendritic cells, B lymphocytes, major histocompatibility complex (MHC) class II antigen and transforming growth factor-beta (TGF-beta). RESULTS: All the cells mentioned above except B lymphocytes were positive and present in a small number in the peripheral cornea and limbus of normal rats. A massive influx of CD3, CD4, CD8 positive cells, macrophages, dendritic cells, MHC class II and TGF-beta positive cells not only into cornea but also into the iris was observed 7 days after allograft corneal transplantation. Whereas no B cell was found in the allograft. Such a cellular response was not found in the rats in which corneal transplantation with autologous cornea was performed. CONCLUSION: T cells, Th cells, Ts cells, macrophages, dendritic cells, MHC class II positive cells and TGF-beta positive cells are involved in the pathogenesis of corneal allograft transplantation. The involvement of the iris and ciliary body may promote or aggravate the allograft rejection.

Animals↗

PubMed1998

[Recent advances of heterologous gene expression in E. coli].

In recent years, along with the rapid development of genetic engineering technologies, a vast amount of valuable proteins have been expressed in E. coli with high productivity. The problems concerning the productivity and purity of the heterologous proteins are no longer the major ones, as many expression system and protein purification schemes have been developed and perfected. More attention is being payed to the activity, specific activity, correct folding and intactness of the heterologous proteins. Perhaps it is the solutions to such problems that will finally lead to the maturity of the application of recombinant proteins.

Animals↗

PubMed1998

[The relation of neonatal hyaline membrane disease and congenital human cytomegalovirus infection].

To study the relation of neonatal hyaline membrane disease (HMD) and congenital human cytomegalovirus (HCMV) infection, two pairs of primers were synthesized according to the sequence of HCMV conserved region of the immediate--early(IE) gene. The nested polymerase chain reaction (nested-PCR) was used for the detection of HCMV-DNA of the paraffin-embedded lung tissues from neonatal HMD and non-neonatal HMD. 11 of 30 neonatal HMD patients were positive, the positive rate was 36.7%. Specimens of non-neonatal HMD patients were all negative. The difference between the two groups was significant (chi 2 = 5.05, P < 0.025). There is close relationship between neonatal HMD and congenital HCMV infection.

Cytomegalovirus↗

PubMed1998

Modulation of platinum-induced toxicities and therapeutic index: mechanistic insights and first- and second-generation protecting agents.

Platinum-type drugs have proven to be valuable in the treatment of a variety of solid tumors, beginning with the commercial approval of cisplatin 18 years ago. There are several clinically important toxicities commonly associated with the administration of these drugs. Despite the extensive use of cisplatin and carboplatin, the fundamental chemical transformations and mechanisms that underlie their antitumor and toxic effects have not been fully characterized. Several first-generation protective thiols have been clinically studied in an attempt to reduce the toxicity of platinum-type drugs; while some of these agents appear to protect against certain toxicities, nearly all platinum-protecting drugs have their own intrinsic toxicities, which can be additive to the toxicity of platinum-type drugs. Tumor protection by platinum-protecting drugs is an additional untoward effect that is associated with certain types of agents and must be addressed with care. Recent advances in theoretical and laboratory methods and the use of supercomputers have extended our understanding of the possible major mechanisms underlying platinum drug antitumor activity and toxicity; we present strong evidence that there are two classes of chemical species of platinum drug. One class appears to predominantly account for the antitumor activity, and the other class of chemical species produces many of the toxic effects of platinum drugs. We have discovered a new nontoxic, second-generation platinum-protecting agent, known as BNP7787, which appears to selectively inactivate and eliminate toxic platinum species. BNP7787 has recently entered phase I clinical testing in cancer patients.

Amifostine↗