Biomedical subjects

M Xiong

Publications and source records attributed to M Xiong.

At least 37 records · Page 2Linked to original sources

PubMed2001

[Expression of endogenic bone morphogenetic protein in repairing rabbit skull with tissue engineering technique].

OBJECTIVE: To explore the distribution and effect of endogenic bone morphogenetic protein (BMP) in repairing rabbit skull with tissue engineered bone. METHODS: The autologous osteoblast-like cells were instantly implanted onto polyglycolic acid (PGA) matrix coated with collagen. The rabbit skull defect models were established by resection of bilateral 1.5 cm x 1.0 cm full-thickness parietal bone in 18 New Zealand rabbits, which were randomly divided into two groups. In one group, the composite of osteoblast- like cells and PGA matrix were grafted into the defect on one side of the skull as experimental group I, leaving the same defect area on the other side as control group without any graft implanted. In the other group, simply PGA was done in the same way as experimental group II. The tissue samples were harvested at 3, 8 and 14 days postoperatively and examined by histological and immunohistochemistry methods. The concentrations of BMP in different regions of the samples were measured using computer image analysis system. RESULTS: After 3 days of operation, the BMP positive cells were found in the matrix of experimental group I. At 8 days postoperatively, the formation of new bone on experimental group I was prior to that of experimental group II and control group. On the 14th day, bone trabecula was formed on the experimental group I, but there was only fibrous tissue on control group. The concentration of BMP on the experimental group I and II were higher than that of corresponding region on control side. CONCLUSION: The osteoblast-like cells instantly implanted onto PGA matrix can synthesize and secrete BMP. It may be one of the reasons of tissue engineered bone inducing new bone regeneration that localizing endogenic BMP in bone defect area, increasing the concentration of endogenic BMP and improving its distribution by tissue engineering technique.

Animals↗

PubMed2001

CT virtual endoscopy of the auditory ossicular chain: clinical applications.

OBJECTIVE: To evaluate the clinical applications and limitations of CT virtual endoscopy (CTVE) in the auditory ossicular chain. METHODS: CTVE of the auditory ossicular chain was performed with 1.0 mm collimation at pitch 1.0, bone algorithm, 9.6 cm field of view, and 0.1-0.2 mm reconstruction interval in 40 patients with middle ear diseases. 30 cases were confirmed by surgery. Results were compared with the findings of axial high resolution CT (HRCT) and multiplanar reformation (MPR) images and surgery. RESULTS: The accuracy of CTVE images in detecting ossicular destruction was 92.6%, significantly higher than that of axial HRCT (83.9%) and multiplanar reformation (76.5%) images. CTVE could also clearly reveal the postoperative condition and congenital dysplasia of the auditory ossicular chain. CONCLUSIONS: CTVE can clearly demonstrate a three-dimensional image of the auditory ossicular chain and is useful in evaluating diseases of the ear, especially the auditory ossicles. CTVE could not clearly demonstrate abnormal soft tissue within the tympanic cavity, abnormal changes of the tympanic membrane and tympanic walls, and could be easily influenced by artificial factors.

Adolescent↗

PubMed2001

[Clinicopathologic features and prognosis of lymphoepithelioma-like carcinoma of the lung].

OBJECTIVE: To analyze the clinicopathologic features and prognosis of lymphoepithelioma-like carcinoma (LELC) of the lung. METHODS: 26 cases of pulmonary LELC with available long-term follow-up information were compared with 84 cases of pulmonary non-LELC(33 cases of squamous cell carcinoma, 36 cases of adenocarcinoma, 6 cases of adeno-squamous carcinoma and 9 cases of large cell carcinoma) with available long-term follow-up information using Kaplan-Meier method and the generalized Wilcoxon test. RESULTS: LELC of the lung had a better prognosis than non-LELC (P < 0.05). Further study showed that pulmonary LELC had a significantly better prognosis than adeno-squamous carcinoma and large cell carcinoma. However, there was no significant prognostic differences between pulmonary LELC and squamous cell carcinoma and adenocarcinoma. Tumor recurrence and necrosis (> or = 5% of tumor) were associated with poor prognosis. CONCLUSION: Pulmonary LELC, which is a very rare and unique entity, has a better prognosis after therapy.

Adult↗

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

Relationship between tumor suppressor gene p53 and tumors of adipose tissue.

OBJECTIVE: To investigate the relationship between p53 gene and tumors of adipose tissue at the level of protein and gene. METHODS: Immunohistochemical LSAB, PCR-SSCP and DNA sequencing were used in 82 cases. RESULTS: p53 protein is expressed only in liposarcomas, in which the positive staining rate was 48.08% (25/52). In different subtypes of liposarcomas, the positive staining rate in well differentiated liposarcomas was 30.00% (9/30), which is much lower than that of the poorly differentiated liposarcomas (P < 0.005). Abnormality in the single-stranded DNA pattern was determined in 2 samples (pleomophic liposarcomas) by PCR-SSCP analysis. Missense mutations in exon 8 codon 268 of p53 gene (AAC-->ATC) were detected by DNA sequencing. Another heterozygotic cosense mutation may exist at exon 6 codon 221 of p53 gene (GAG-->GAA). CONCLUSIONS: The data suggest that the p53 protein has a relationship with development, differentiation and malignancy of liposarcoma. Detecting the level of p53 protein expression may be valuable in evaluating the level of differentiation and malignancy of liposarcoma. There appear point mutation on exon 8, 6 of p53 gene.

Genes, p53↗

PubMed2001

Laryngeal and hypopharyngeal carcinoma: comparison of helical CT multiplanar reformation, three-dimensional reconstruction and virtual laryngoscopy.

OBJECTIVE: To evaluate the clinical application of helical CT multiplanar reformation (MPR) three-dimensional reconstruction (3D) and virtual laryngoscopy (CTVL) in laryngeal and hypopharyngeal carcinoma. METHODS: Axial helical CT scans were performed in 22 patients with laryngeal or hypopharyngeal carcinoma, along with MPR, 3D and CTVL. These results were compared with the findings of fiber optic laryngoscopy and surgery. RESULTS: Combining axial and MPR images, both the accuracy in preoperative tumor staging and the diagnosis of metastatic lymph nodes were 95%. MPR demonstrated more information about the extent of tumor than axial images in 23% cases; 3D image displayed clearly the extension of tumor, the vessels and airway from multiple views. The location, size and extent of tumors found in cranio-caudal CTVL corresponded well with that of laryngoscopy, and CTVL demonstrated the relationship between the tumor and vocal cords and anterior commissure by caudo-cranial approach, which was inaccessible to fiber optic laryngoscopy in 3 cases. CONCLUSIONS: Axial images of helical CT clearly demonstrate the location, size and extent of laryngeal and hypopharyngeal carcinoma, while MPR and 3D images are useful in displaying the three-dimensional images and anatomical relation of the tumor. CTVL can clearly display the mucosal surface structures of the larynx and hypopharynx and is a good complementary method of laryngoscopy.

Adult↗

PubMed2001

Confirmation of susceptibility gene loci on chromosome 1 in northern China Han families with type 2 diabetes.

OBJECTIVE: To confirm previous effort to identify type 2 diabetes susceptibility genes in a Northern Chinese population by conducting a new genome scan with both an increased number of type 2 diabetes families and a new set of microsatellite markers within the previously localized regions. METHODS: A genome scan method was applied. After multiplexed PCR, electrophoreses, genescan and genotyping analysis, we obtained size information for all loci, and then a further study was done by both parametric and non-parametric linkage analysis to investigate the P values and Z values of these loci. RESULTS: We surveyed 34 microsatellite markers which distributed within 5 regions along chromosome 1, and a total of 12,000 genotypes were screened. Evidence of linkage with diabetes was identified for 8 of the 34 loci. All P values of the 8 loci were lower than 0.05, and the highest Z value was 2.17. A very interesting finding is that all 5 markers at the p- terminal 1p36.3-1p36.23 region, spanning a long range of 16.9 cM, were identified to have a low P value of less than 0.05, which suggests that this region may contain multiple susceptibility genes. Regions 4 and 5 also confirmed the previous findings, and we narrowed these two regions to a 2.7 cM and 2.5 cM regions, respectively. CONCLUSIONS: We further confirmed the results gained in the previous genome-wide scan using an increased number of NIDDM families and a new set of microsatellite markers lying within the initially localized regions. The fact that all 5 loci at the p- terminal region displayed a low P value of less than 0.05 suggests that more than 1 susceptibility gene may reside in this region.

Chromosomes, Human, Pair 1↗

PubMed2001

[CT virtual bronchoscopy in the diagnosis of central lung cancer].

OBJECTIVE: To evaluate the clinical application of CT virtual bronchoscopy(VB) in the diagnosis of centrally located lung cancer. METHODS: Forty-five cases confirmed by fiberoptic bronchoscopy and pathology underwent volume scanning using spiral CT (HiSpeed Advantage CT/i. GE Medical Systems, U.S.A). The patients examined included 33 with central lung cancer, 8 with post-operative residual bronchial stumps, 2 with post-radiotherapy lung cancer, and 2 with tracheal carcinoma. Data were transferred to computer workstation (GE Advantage Windows 3.1) and CT virtual bronchoscopic (CTVB) images with pseudocolor encoding were generated using Navigator Smooth soft-ware. RESULTS: CTVB could reveal 100% segmental bronchus and 80% subsegmental bronchus simulating fiberoptic bronchoscopy. The tumors appeared as masses or nodules, causing bronchial wall thickening and occlusions. Post-operative residual bronchial stumps showed smooth end without recurrence of tumors or appeared as nodular protrusion if tumor recurred. The post-radiotherapy bronchial wall was uneven and there was narrowing of bronchial lumen. CONCLUSION: CTVB is a noninvasive method of observing the airway. It stimulates the images observed under fiberoptic bronchoscopy and com be used partly in lieu of it. Associated with multiplanar reformat, CTVB can demonstrate extraluminal invasion of the tumor. The limitations of CTVB are that it is not possible to observe mucosal abnormalities and perform biopsy.

Adult↗

PubMed2001

[The clinical usefulness of helical CT multiplanar reformation, three-dimensional reconstruction and virtual laryngoscopy in laryngeal and hypopharyngeal carcinomas].

OBJECTIVE: To evaluate the clinical applications of helical CT multiplanar reformation (MPR), three-dimensional reconstruction (3D) and virtual laryngoscopy (CTVL) in laryngeal and hypopharyngeal carcinoma. METHODS: Axial helical CT scan was performed in 24 patients with laryngeal or hypopharyngeal carcinoma, meanwhile MPR, 3D and CTVL were performed on each patient. The results were compared with the fiberoptic laryngoscopic and surgical findings. RESULTS: Axial helical CT combined with MPR images, the accuracy of preoperative tumor staging and detection of metastatic lymph nodes were both 96%. In 25% of the cases, MPR was more informative than axial images about the extent of tumor invasion. The 3D image three-dimensionally displayed the extent of tumor invasion, and its relation to blood vessels and airway. On CTVL, the location, size and extent of intraluminal tumors of the larynx and hypopharynx when observed from above corresponded well with those observed under laryngoscope. In 4 patients, CTVL observed from below, demonstrated the relationship between the tumor and vocal cords and anterior commissure inaccessible to fiberoptic laryngoscopy. CONCLUSION: Helical CT axial scanning combined with MPR, 3D and CTVL images, can provide more comprehensive information about laryngeal and hypopharyngeal carcinoma.

Adult↗

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↗

PubMed2001

[E-cadherin associated protein expression and its significance in invasive lobular carcinoma and invasive ductal carcinoma of breast].

OBJECTIVE: To study E-cadherin associated proteins alpha-, beta-, gamma-catenin expression and their significance in invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) of breast. METHODS: Immunohistochemistry staining (labeled streptavidin-biotin method) was used to detect alpha-, beta-, gamma-catenin expression in invasive breast carcinoma (19 cases of ILC and 32 cases of IDC ). RESULTS: The loss and reduction rate of alpha-, beta-, gamma-catenin expression in ILC was 78.9% (15 cases), 52.6% (10 cases) and 84.2% (16 cases), respectively. The rate of alpha-, beta-, gamma-catenin expression showing loss and reduction in IDC was 75.0% (24 cases), 43.8% (14 cases) and 81.3% (26 cases), respectively. The staining intensity of alpha-, beta-, gamma-catenin expression in invasive carcinoma of breast was weaker than that in foci of carcinoma in situ (semiquantitative grading). There was a positive relationship between the expression of alpha-catenin and beta-catenin in invasive breast carcinoma. No significant association was seen between reduced protein expression of alpha-, beta-, gamma-catenin and the development of lymph node metastasis. CONCLUSION: alpha-, beta-, gamma-catenin expression was almost identical in ILC and IDC of breast, showing significant loss and reduction of protein expression in the carcinoma cells of invasive breast carcinoma, suggesting that alpha-, beta-, gamma-catenin may lose their normal adherent ability in the pathogenesis of invasive breast carcinoma.

Adult↗

PubMed2001

[Gene chip technology and its advances in medical science].

Gene (DNA) chip or DNA microarray is a new technique developed during human genomic research programs. When DNA chip containing thousands of DNA or oligonucleotide are hybridized to labeled samples, gene expression, DNA sequencing as well as DNA mutation and polymorphism can be analyzed with high efficiency in large scale. We are able to perform this technique on dozens of specimens at once in tumor differentiation, tumor typing, tumor diagnosis, tumorigenesis, and new tumor-associated genes discovery.

Gene Expression Profiling↗

PubMed2001

[Primary giant cell malignant fibrous histiocytoma of the lung].

A case of primary giant cell malignant fibrous histiocytoma (MFH) of the lung was reported. Gross findings showed two well demarcated isolated nodules located in the right lower lobe of the lung appeared yellowish-gray and gray-red on gross section with areas of focal calcifications, hemorrhage and necrosis. Microscopic findings showed that the tumor consisted of diffuse neoplastic histiocytes and spindle-shaped fibroblasts arranged in a prominent storiform pattern intermingled with numerous multinucleated tumor giant cells and osteoclast-like multinucleated giant cells. Focal osteoid tissue was mainly located at the periphery of the tumor. In addition, a number of scattered apoptotic multinucleated giant cells were observed. Tumor cells were positive for vimentin, alpha-1-antitrypsin, lysozyme and mac387, but negative for cytokeratin, actin, S-100, NSE, and NF. Primary giant cell MFH of the lung is a very rare malignant tumor. This tumor should be treated by prompt radical surgery.

Adult↗

PubMed2000

Combined linkage and linkage disequilibrium mapping for genome screens.

Linkage analysis and association studies, two major approaches for genetic studies of human diseases, are useful for mapping genes that are highly penetrant, but both use only part of the information that is available for mapping disease genes. Therefore, they provide limited utility when used alone. In this report, we present combined linkage and linkage disequilibrium mapping that simultaneously utilizes linkage and linkage disequilibrium information for mapping human disease genes. Compared with the existing linkage analysis and association study methods, this method has several advantages: 1) it has high statistical power by a joint analysis of linkage and linkage disequilibrium for localizing disease susceptibility loci: 2) it unifies the theory of linkage analysis and linkage disequilibrium mapping, 3) it retains the general framework for linkage analysis and, hence, can be easily incorporated into the existing software for the linkage analysis. The proposed LLDM is applied to familial hemophagocytic lymphohistiocytosis (FHL) disease.

Chromosome Mapping↗

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

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↗

PubMed2000

The haplotype linkage disequilibrium test for genome-wide screens: its power and study design.

The focus of human genetics continues to shift toward the dissection of complex phenotypes. Integral to these endeavors is the development of powerful analytical tools. To this end, we propose a novel method designated the haplotype linkage disequibrium (LD) test for identifying diseases genes. The basic structure of the haplotype test statistic is a chi-square in which haplotypes, as opposed to individual marker data, are compared between cases and controls. Specifically, we performed power calculations and demonstrate that the use of haplotypes improves the power of mapping disease genes. We show that this approach can be used for initial genome-wide screens in mapping disease genes. Furthermore, we investigated the factors influencing statistical power of the method and discussed basic principals underlying study design. Published data from the Hereditary Hemochromatosis region was used to illustrate the utility of the haplotype test. Also discussed is its relationship with linkage disequibrium.

Alleles↗

PubMed2000

Association of Epstein-Barr virus with lymphoepithelioma-like carcinoma of the lung in southern China.

Having reviewed the data on 3,663 consecutive cases of primary lung carcinoma in southern China, we found that 32 cases could meet the criteria for lymphoepithelioma-like carcinoma (LELC) of the lung. To study the relationship between pulmonary LELC and Epstein-Barr virus (EBV) infection, we used in situ hybridization and immunohistochemistry techniques to detect the EBV-encoded small nonpolyadenylated RNA (EBER), latent membrane protein 1 (LMP1), and viral capsid antigen (VCA) in 32 cases of LELC and 19 cases of non-LELC lung carcinoma. Of the 32 cases, 30 (94%) showed EBER positivity. Of the 30 EBER-positive pulmonary LELC cases, 16 and 7 expressed LMP1 and VCA, respectively. In contrast with LELC, none of the 19 cases of non-LELC lung carcinoma showed EBER-, LMP1-, or VCA-positive signals in carcinoma cells. The results demonstrate that there is a close relationship between EBV infection and pulmonary LELC. EBV infection may have an essential role in the tumorigenesis of pulmonary LELC. EBV latent infection is the main status in pulmonary LELC except for individual EBV entering into a lytic cycle.

Adult↗