Biomedical subjects

Dong-mei Li

Publications and source records attributed to Dong-mei Li.

10 recordsLinked to original sources

PubMed2006

[Study on Bartonella vinsonii berkhoffii isolated from blood of native dogs in China].

OBJECTIVE: To isolate and identify Bartonella strains from native dogs in Shandong province in China. METHODS: EDTA-anticoagulated blood samples were collected from 71 native dogs in Yanggu county of Shandong province in March 2005. All isolates were grown on brain heart infusion agar plates containing 5% defibrinated rabbit blood. The agar plates were incubated at 37 degrees C in a humidified with 5% CO2 environment for 4 weeks or longer. All Bartonella-like isolates were examined by routine Gram and Giménez staining and then followed by polymerase chain reaction (PCR) and PCR-RFLP analysis for identification and differentiation of the isolates. Sequencing 16S rRNA, citrate synthase (gltA) gene and 16S-23S rRNA ITS were carried out and sequential similarities were calculated using the DNASTAR5 software package. The phylogenetic tree was inferred from each bootstrap sample, using the neighbor-joining methods as executed in the MEGA 3.1 software. The translation from DNA to protein were determined by DNASIS 2.5. RESULTS: The two Bartonella-like organisms (strains Q52SHD and Q64SHD) were isolated from the blood of 71 dogs. Light microscopic examination of the Gram and Giménez-stained micro-organisms showed small, short and slightly curved pleomorphic gram-negative bacilli. Amplified products of the three pairs of Bartonella genus-specific primers carried the same size as the predicted of those Bartonella species. Data from PCR-RFLP analysis showed that the two strains that having the same profiles were all different from the B. henselae type strain-16S rRNA, gltA and 16S-23S rRNA ITS sequences from the two isolates were 100.0%, 99.7% and 97.2% homologous to B. vinsonii berkhoffii. CONCLUSIONS: Based on these findings, the two isolates Q52SHD and Q64SHD were demonstrated as B. vinsonii berkhoffii. To our knowledge, this was the first report on the presence of Bartonella infection in native dogs from China, which constituted a large reservoir of Bartonella species in this country.

Animals↗

PubMed2006

[Effect of rapamycin and dexamethasone on differentiation and maturation of murine bone marrow-derived dendritic cells].

AIM: To observe the effect of rapamycin (Rap) and dexamethasone (Dex) on differentiation and development of murine bone marrow-derived dendritic cells (DC) in vitro. METHODS: DC cells generated from C57BL/6 murine bone marrow cells were induced by GM-CSF and IL-4. During the course, Rap or Dex was added to the culture and the cells were then stimulated by LPS. (1)Morphology development of DCs was observed by inverted microscope and scanning electron microscope.(2)The cells were analyzed by flow cytometry (FCM) to determine the proportion of CD11c(+) cells and the change of CD86 and MHC class II molecule.(3)The influence of DCs treated by Rap or Dex on the allogeneic T cell proliferation was studied by one-way MLR. RESULTS: (1)The morphology of DCs maintained in a durable state of immaturity after Rap or Dex pretreatment.(2)The expression of CD11c and MHC-II slightly decreased but CD86 dramatically reduced on Rap-treated DC cells. There was close relationship between the expression of CD11c on Dex-treated cells and the dosage of Dex. The surface expression of CD86 and MHC-II dramatically reduced on Dex-treated DCs. Moreover, DCs treated by Rap or Dex were both able to resist the maturation triggered by LPS.(3)Bone marrow-derived DCs cultured with Dex or Rap had a lower stimulatory effect on allogeneic T cells compared with that of mature DCs. CONCLUSION: Rap and Dex could keep DCs in durable immaturity. Compared with Dex, which inhibited the expression of co-stimulatory molecules, Rap hardly influenced the differentiation of DCs and the expression of MHC class II molecules.

Animals↗

PubMed2006

[Eye socket reconstruction with free flap].

OBJECTIVE: To discuss the effect of eye reconstruction with free flap. METHODS: Free flap was used in 21 patients of contracted eye socket and anophthalmos. The forearm free flap was utilized in 19 patients,the scapular flap in 2. Free flap with microvascular anastomoses was transferred into contracted eye socket. And hydroxyapatite implant was selectively inserted for intraorbital implantation according to the extent of contracted eye socket postoperation. Eye socket was reconstructed in one stage operation. RESULTS: The flaps were transferred successfully in all patients. All patients were followed up between 4 to 42 months, better cosmetic results were achieved and well-fitted eye prosthesis was weaned. CONCLUSION: Free flap is a useful alternative in treatment of severe contracted eye socket.

Adolescent↗

PubMed2005

[Relationship of CTLA-4 exon 1 A49-->G polymorphism with sCTLA-4 and Th1/Th2 bias in idiopathic dilated cardiomyopathy].

OBJECTIVE: To investigate the association of cytotoxic T lymphocyte associated antigen-4 (CTLA-4) gene exon 1 A49-->G polymorphism with the genetic susceptibility to idiopathic dilated cardiomyopathy (IDC) in Chinese Han nationality. METHODS: Peripheral blood samples were collected from 48 patients with IDC, 31 males and 17 females, and 50 sex- and age-matched normal controls. ELISA was used to examine the cytokines: sCTLA-4, gamma-interferon (IFN-gamma), and interleukin-4 (IL-4)with the ratio of IFN-gamma/IL-4 as an indicator for Th1/Th2 bias. PCR-RFLP was used to analyze the A/G polymorphism of CTLA-4 exon 1 A49-->G. The relationship of CTLA-4 genotype and alleles frequencies with sCTLA-4, IFN-gamma and IFN-gamma/IL-4 was evaluated by linear regression analysis. RESULTS: Compared with the normal controls, the frequencies of GG genotype (0.6042 and 0.7396, P = 0.012) and the G allele (0.36 and 0.56, P = 0.008) were significantly increased in the patients with IDC. Increased serum sCTLA-4 was found in the IDC group compared with the controls (1.87 microg/L +/- 1.06 microg/L vs. 0.54 microg/L +/- 0.19 microg/L, P < 0.05). IFN-gamma was significantly lower in the IDC group than in the control group (16 ng/L +/- 6 ng/L vs. 30 ng/L +/- 10 ng/L, P < 0.05). The ratio of IFN-gamma/IL-4 was significantly in the IDC group than in the control group (1.63 +/- 0.50 vs. 3.01 +/- 0.89, P < 0.05). No statistically difference was found in the IL-4 level between the two groups. Linear regression analysis manifested significant interrelationship between the GG genotype, G allele frequencies and serum sCTLA-4 (r = 0.57, P = 0.021), IFN-gamma/IL-4 ratio (r = 0.42, P = 0.028) in the IDC group. While no correlation was found for AA, AG genotype and the A allele frequency. CONCLUSION: CTLA-4 gene exon 1 A49-->G substitution is associated with an increased IDC genetic susceptibility, which implicates that the CTLA-4 gene may have a significant role in IDC, possibly via a Thr-->Ala change in CTLA-4 signal peptide, with a result of functional change of sCTLA-4. The bias of Th1/Th2 paradigm is associated with the increased sCTLA-4 level under certain background of immunogenicity.

Antigens, CD↗

PubMed2005

[Modification of titanium surface with calcium and phosphorus ions using micro-arc oxidation and its effect on osteoblast attachment].

OBJECTIVE: To study the method for modifying titanium surface with calcium and phosphorus ions using micro-arc oxidation technique and observe osteoblast attachment to the modified surface. METHODS: TA(2) titanium discs were treated with micro-arc oxidation in electrolyte solution containing Ca(2+) and PO(4)(3-). The influence of Ca(2+) and PO(4)(3-) concentrations in the solution and the electrical parameters of the micro-arc oxidization on the content of calcium and phosphorus ions incorporated into the surface of titanium was investigated using energy-dispersive X-ray (EDX) analysis. Scanning electron microscopy was employed for morphological observation of the ceramic coating on the metal surface. The binding strength of ceramic coating with titanium was tested by shear bonding experiment. MC-3T3-E1 osteoblast-like cells were then cultured on the treated surface of titanium discs to investigate the influence of the ceramic coating on osteoblast attachment. RESULTS: Micro-arc oxidation treatment produced a layer of porous TiO(2) coating on the surface of titanium discs, with the average pore size of 2 to 10 mum. EDX analysis revealed that the ceramic coating contained Ca and P elements, whose content had close correlation with Ca(2+) and PO(4)(3-) concentrations in the electrolyte solution and voltage, duty cycle and frequency of micro-arc oxidation. The average bonding strength of the ceramic coating with titanium was 22+/-3 MPa, and TiO(2) coating promoted attachment and spread of osteoblast-like cells on the metal surface as demonstrated by cell culture. CONCLUSIONS: Porous TiO(2) coating can be constructed on the surface of titanium using micro-arc oxidation, and Ca(2+) and PO(4)(3-) incorporated into the coating can improve the biocompatibility of titanium. The content of Ca(2+) and PO(4)(3-) in the coating can be modulated by adjusting the concentrations of Ca(2+) and PO(4)(3-) in the electrolyte solution and the electrical parameters of the micro-arc oxidation.

3T3 Cells↗

PubMed2005

[Experimental study of using acellular dermal dermis instead of donor sclera in orbital implantation].

OBJECTIVE: To evaluate the histocompatibility of homologous acellular dermal matrix as a wrapping material for a hydroxyapatite orbital implant and compare the speed of fibrovascular ingrowth in hydroxyapatite orbital implant wrapped with homologous acellular dermal matrix and homologous sclera respectively. METHODS: Twenty four New Zealand rabbits were divided into two groups randomly. One group is implanted with hydroxyapatite orbital implant wrapped with homologous acellular dermal matrix behind the globe, the other group with homologous sclera. The observation included immunological reaction of the globe postoperation. Biopsies of implanted material were taken on weeks 1, 4, 8 and 12 postoperation for histopathological and electron microscope examination. RESULTS: Histological examination showed the homologous acellular dermal matrix has no immunological and inflammatory reaction after implanted in orbit. But the speed of fibrovascular ingrowth is a little slower than that of homologous sclera. CONCLUSIONS: The homologous acellular dermal matrix has the better histocompatibility as an encapsulating biomaterial, it can be a new material instead of homologous sclera.

Animals↗

PubMed2004

[Study on Bartonella infection using molecular biological diagnostic techniques from China].

OBJECTIVE: To establish polymerase chain reaction (PCR) technique for the detection of specific genes related to species of genus Bartonella, and for diagnosing clinically suspected cat-scratch disease (CSD) case complicated with pneumonia on both lungs. The appearance of Bartonella infectious diseases calls for genus and species detection and tools for identification in order to make clinical diagnosis and carry on epidemiological studies. METHODS: One pair of primer TIle.455p-TAla.885n was designed based on the fact that tRNA(Ile)-tRNA(Ala) intergenic spacer region in 16S-23S rRNA intergenic spacer (ITS) of genus Bartonella were high variable sequences flanked by completely conserved tRNA-encoding genes. 16S-23S rRNA was longer than that which had been described in other bacteria. Two published pairs of primers were used to directly detect the specific gene fragments of Bartonella species DNA extracts from human blood, followed by PCR product Sequencing and nucleotide base sequence analysis. RESULTS: Amplification products of the three pairs of primers had the same predicted size of those in Bartonella spp. According to the different length of electrophoresis bank, the sample was identified as a species of genus Bartonella other than the positive control. Sequence analysis showed that the nuleotide sequence from the PCR product of primer TIle.455p-TAla.885n was identical to the Bartonella isolated from Yunnan in China. CONCLUSIONS: PCR-based assay provided a simple and rapid means to detect pathogenic Bartonella species in humans and mammalian hosts as well as in arthropod vecters. This study suggested that this pathogenic Bartonella species existed in patients in northern and southern parts of China.

Animals↗

PubMed2004

[Eye socket reconstruction with free radial forearm flap in anophthalmic orbital syndrome and contracted eye socket].

OBJECTIVE: To assess the effect of eye socket reconstruction with free radial forearm flap. METHODS: Reconstructive procedures were performed in 7 patients underwent orbital exenteration for malignant tumors and in 9 patients underwent enucleation and postoperative irradiation of the orbit for the treatment of retinoblastoma. These patients were suffered from anophthalmic orbital syndrome and contractive eye socket. A microvascular surgical technique with a free radial forearm flap was adopted. Hydroxyapatite implant was inserted as an intraorbital implantation. RESULTS: All patients were followed up for 6 months to 5 years and good cosmetic results were obtained. A large eye socket was achieved permanently. Artificial eye could be fitted with satisfactory results. CONCLUSION: Free radial forearm flap transplantation offers a useful option for the treatment of anophthalmic orbital syndrome.

Adolescent↗

PubMed2004

[Experimental study of the biocompatible and osteoinductive behavior of the hydroxyapatite/ultra-high molecular weight polyethtlene composite].

OBJECTIVE: To compare the biocompatibility and osteoinductive behavior of HA (hydroxyapatite) and HA/UHMWPE (ultra-high molecular weight polyethtlene) composite in orbital implantation. METHODS: Osteoectomy of the upper orbital rim was perform on 24 adult New Zealand rabbits. The animals were randomly divided into 4 groups with 6 of each. The HA, HA/UHMWPE composite or UHMWPE (10 mm x 10 mm x 3 mm in size) was implanted to the upper orbital defect of the animal in respective group. Animals were sacrificed at 1, 4, 8, 12 weeks. Histopathologic sections of the implants were evaluated and compared with light and transmission electron microscopy study. RESULTS: During the experimental period of 12 weeks, there was no implant extrusion or displacement. In the groups of HA and HA/UHMWPE composite, vascular ingrowth and fibroblasts were observed shortly and osteocytes were seen at 8 weeks. Calcium deposition of the implants showed a laminar fashion at 12 weeks. In the group of UHMWPE, fibrous membranes were seen around the implant at 1 week. Transmission electron microscopy study showed that in the HA and HA/UHMWPE groups, fibroblasts and vascular ingrowth could be seen, but osteocytes were not observed. CONCLUSION: HA/UHMWPE composite demonstrated biocompatibility and osteoinductive property. It would be a good substitute for bone, particularly for orbital bone.

Animals↗

PubMed2004

[Study on the prevalence of Bartonella species in rodent hosts from different environmental areas in Yunnan].

OBJECTIVE: To investigate Bartonella infections in small mammalian reservoir hosts from different environments and types of climate in Yunnan. METHODS: Femoral blood samples were collected from the anesthetic captured animals from five counties including three types of climate. All isolates were grown on brain and heart infusion agar plates containing 5% defibrinated rabbit blood. The agar plates were incubated at 35 degrees C in a humidified with 5% CO2 environment for at least 4 weeks. Bartonella-like isolates were confirmed by the polymerase chain reaction and visualizing the target gene fragment by gel electrophoresis. RESULTS: Bartonella species were isolated from 69 of 176 small animals including 4 species of 3 genera from 4 counties and the total prevalence in rodents was 39.2%. The maximal prevalence was 42.0% of Rattus tanezumi flavipectus usually inhabiting indoors and courtyard and contacting closely to human. Moreover, Bartonella isolates were obtained from Rattus noruegicus, Eothenomys miletus and Mus pahari. Life environments of captured animals involved indoors, courtyard, brush and forest in mountain. CONCLUSION: The finding in this study suggested the characteristic of diversity of Bartonella infections in rodent hosts in southern China included Bartonella species parasiting in a wide range of animal hosts in different environments as well as climate types. Further investigations were needed in different areas in China to confirm more mammalian reservoir hosts with Bartonella infections.

Animals↗