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Biomedical subjects

M Zhang

Publications and source records attributed to M Zhang.

At least 253 records · Page 14Linked to original sources
PubMed2001

[Microskin grafting in recent 15 years].

OBJECTIVE: To summarize microskin grafting in recent 15 years. METHODS: Microskin grafting was performed in 162 patients with extensive burns. The indications and forms of the grafting, mechanization in making microsk in and outcome of wound recovered by micrografts were discussed. RESULTS: Extremely extensive third degree burns, common extensive third degree burns and extensive granulation wound were healed byn different ways of microskin grafting. A new machine was used to mince micrografts with good clinical results. The homografts as coverture was exfoliated in either necrosis or desquamation. Scar formation was related to wound repair. CONCLUSIONS: Microskin grafting has made progress in recent years. The orientation and even spread of micrografts are very important for good wound repair. The technic should be further improved.

Adolescent↗
PubMed2001

[Expression of ADAM12 (Meltrin-alpha) gene in giant cell tumor of bone].

OBJECTIVE: To detect expression and location of ADAM12 (meltrin-alpha) gene in giant cell tumor of bone and to study its effect on the formation of multinucleated giant cells in the tumor. METHODS: ADAM12 mRNA was detected by RT-PCR and RNA in situ hybridization in 18 cases of giant cell tumors, 6 cases of cultured tumor cells, 2 specimens of embryonic muscle tissue and 5 specimens of adult muscle tissue. RESULTS: RT-PCR showed that 12/18 (67%) cases of giant cell tumor of bone expressed ADAM12 mRNA. RNA in situ hybridization demonstrated positive ADAM12 mRNA in 12 cases of the detected tumors. The ADAM 12 mRNA positive signal was localized in the cytoplasm of almost all multinucleated giant cells and mononuclear stromal cells. However, the expression of ADAM12 mRNA decreased gradually, and eventually lost with increased passages of tumor cells and the disappearance of multinucleated giant cells in the culture. CONCLUSION: Multinucleated giant cells probably originated from the fusion of mononuclear stromal cells and ADAM12 may participate in the fusion process.

ADAM Proteins↗
PubMed2001

[Piezoelectric ceramic--a novel material for bone replacement].

Based on the piezoelectric effect of nature bone, the biocompatibility of a piezoelectric ceramic and bone tissue is observed and studied in four aspects: cytocompatibility, tissue-compatibility, mechanical compatibility and electro-compatibility. The results show that the piezoelectric ceramic is biocompatible. It is not harmful to the morphology and proliferation of L929. There is osteal combination between the piezoelectric ceramic and bone. Its mechanical properties are also suitable for bone replacement. Especially, it can induce the growth of osseous tissues along the chosen direction according to the piezoelectric properties of bone. It is envisaged that the piezoelectric ceramic may be developed and used as a novel material for bone replacement.

Animals↗
PubMed2001

Contrast enhanced MR angiography in pulmonary sequestration.

OBJECTIVE: To evaluate the feasibility of contrast enhanced three-dimensional (3D) magnetic resonance angiography (MRA) in identifying the systemic blood supply in pulmonary sequestration. METHODS: Three patients who were suspected of pulmonary sequestration were examined by contrast enhanced 3D MRA. MR images were compared with surgical findings. RESULTS: Contrast enhanced 3D MRA clearly demonstrated systemic arteries from the descending thoracic aorta supplying the basilar segments of the lower lobe in each case. Pulmonary veins from these segments, which drained into the left atrium in two cases, were also detected. MRA images were consistent with those observed in surgery. CONCLUSION: Contrast enhanced 3D MRA allows accurate diagnosis of pulmonary sequestration and may obviate the need for more invasive investigations.

Adult↗
PubMed2001

[Factors of laccase producing and fermentation conditions by a new white-rot fungus AH28-2].

White-rot fungus AH28-2, a newly isolated strain, produced effectively laccase by induction when grown on a synthetic medium. Aromatic compounds of low molecular weight had an inducing influence on laccase production and its isoenzyme compositions. The using of o-toluidine or syringic acid had the best inducing effect. Cu2+ concentration in medium had distinguished effect on laccase production. Enzyme activity was notably increased by Cu2+ and reached the maximum when Cu2+ final concentration was 5 mumol/L. Mn2+ inhibited the synthesis of laccase. Carbon and nitrogen limitation were not beneficial to laccase synthesis, while high nutrient organic medium was beneficial to the growth of cell and the synthesis of laccase. Using cellobiose as the sole carbon source, the highest level enzyme activity reached 82,923. 7 u/L under the condition of optimum fermentation with ABTS as substrate. This enzyme activity was 2.9-fold higher compared to the reported data on international references in recent years.

Basidiomycota↗
PubMed2001

Sequence and chromosomal assignment of a human novel cDNA: similarity to gamma-aminobutyric acid transporter.

Gamma-aminobutyric acid (GABA) is the predominant inhibitory neurotransmitter in the mammalian brain. Although initially thought to be confined to the central nervous system, GABAergic activity has also been described in other tissues throughout the body. In the present study, we report the cloning and localization of human GABA transporter cDNA and document its expression in various human tissues. A human liver cDNA library was initially screened by a 32P-labeled murine brain GABA transporter 3 (GAT-3) cDNA probe, and full-length cDNA was cloned by employing Marathon-Ready human kidney cDNA. The human GABA transporter cDNA encoded a 569 amino acid hydrophobic protein with 12 transmembrane domains (TMs). Search of published sequences revealed high homology with rat GAT-2, murine GAT-3 cDNA, human solute carrier family 6 member 13 (SLC6A13), and a human peripheral betaine/GABA transporter. Northern blot analyses demonstrated that the human GABA transporter is expressed strongly in the kidney and to a lesser extent in the liver and brain. The sequence was well matched with human chromosome 12p13.3, suggesting the human GABA transporter contains 14 exons. The above findings confirm the existence of and further characterize a specific GABA transporter in human tissues.

Amino Acid Sequence↗
PubMed2001

[Corneal topography and pachymetry in normal eyes].

OBJECTIVE: To evaluate the corneal topography and pachymetry on normal eyes. METHODS: The Orbscan corneal topography system was used to investigate corneal topography and pachymetry on 46 normal subjects. RESULTS: In normal eyes, island-shape was the most common type in the elevation topography of anterior corneal surface, followed by incomplete ridge, regular ridge, irregular ridge and unclassified type. For the elevation topography of posterior corneal surface, the most common type was also the island-shape, followed by regular ridge, incomplete ridge and irregular ridge. The thinnest point of cornea in normal eyes was located (0.90 plus minus 0.51) mm away from the visual axis with the thickness of (0.55 plus minus 0.33) mm, which was commonly seen at the inferotemporal quarter of cornea, followed by superotemporal, inferonasal and superonasal quarter. The mean corneal thickness was the least in corneal center and greatest in superior part of cornea. For the color-coded map of corneal thickness, oval shape was the commonest type, followed by round shape, eccentric oval shape and eccentric round shape. CONCLUSIONS: The normal parameters on pan-corneal thickness and corneal shape of both anterior and posterior surface will provide much more useful informations in finding abnormal cornea. Orbscan topography system is a useful instrument for the evaluation of corneal shape and thickness, which is helpful in corneal refractive surgeries.

Adult↗
PubMed2001

[The effects of ecdysterone on the apoptosis and necrosis of cultured HUVEC induced by endotoxin].

OBJECTIVE: To study the protective effects of ecdysterone (EDS) on the apoptosis and necrosis of cultured HUVEC induced by endotoxin. METHODS: HUVEC was cultured in vitro. Apoptosis and necrosis of HUVEC were induced by LPS, and EDS was added in test specimen. Apoptosis was determined by means of flow cytometry and fluorescent microscopy. RESULTS: There was relatively less number of apoptosis and necrosis of in vitro cultured normal HUVEC than that after LPS stimulation, whereas apoptosis dominated over necrosis. After EDS was added to the culture of HUVEC, cell apoptosis and necrosis decreased simultaneously. CONCLUSION: EDS might exert protective effects on cultured HUVEC against apoptosis and necrosis induced by LPS.

Apoptosis↗
PubMed2001

[Analysis of bacterial resistance to antibiotics in a burn ward].

OBJECTIVE: To analyze the bacterial resistance to antibiotics in a burn ward in the past 4 years. METHODS: Six hundred and fifty strains of bacteria were isolated from the wounds and blood of burn patients admitted to our hospital in recent 4 years. Slip agar diffusion method was employed to carry out antibiotic sensitivity test, and the results were interpreted according to the NCCLS criteria. Extended spectrum beta -- lactamases (ESBLs) were detected by double slips synergic test in 45 strains of Klebsiella Pneumoniae. RESULTS: Only vancomycin was effective for staphylococcus aureus, and Imipenem was effective for E. coli, E. cloacae and K. pneumoniae. But P. aeruginosa was only susceptible to polymyxin -- B. In addition, Thirty -- eight out of 45 strains of K. pneumoniae were ESBLs positive with the incidence of 84.4%. CONCLUSION: The high resistance of the bacteria to most antibiotics in our burn ward might be related to the high production of beta -- lactamases and especially ESBLs. Imipenem remained stable to ESBLs and remained highly effective for most bacteria. But antibiotics with beta -- lactamases inhibitor became less effective in recent years. The resistance rate of P. aeruginosa to Imipenem increased gradually in recent years. This might be due to the abuse of Tienam in burn patients, which stimulated the bacteria to produce a new metallic beta -- lactamases transfected by plasmid, decreasing the production of bacterial outer membrane proteins and inducing a change in membranous permeability.

Anti-Bacterial Agents↗
PubMed2001

[Clinical study on the early and short -- term use of antibiotics with broad spectrum in severely burned patients].

OBJECTIVE: To investigate the prevention and treatment effects of early and short -- term use of antibiotics with broad spectrum on postburn severe infection in severely burned patients. METHODS: Thirty -- five burn patients with TBSA from 50% to 95% were enrolled in the study. The patients were divided into early prevention [20 cases, antibiotics were used started from 6 postburn hours (PBH)] and delayed prevention (15 cases, antibiotics were applied after 48 PBH) groups. Plasma levels of LPS, TNFa and IL -- 8 were dynamically monitored with the concomitant observation of clinical signs of postburn sepsis. RESULTS: After major burns, the plasma levels of LPS, TNFalpha and IL -- 8 increased evidently and reached the peak values on 3 similar 5 postburn days (PBD). But the levels of all above factors in the early group were obviously lower than those in the delayed group (P < 0.05 similar 0.01). The incidencies of sepsis and internal organ complications within 2 postburn weeks were much lower in the early group than those in the delayed group (P < 0.05). The subeschar bacterial quantification on 4 similar 7 PBD was evidently lower in the early group than that in the delayed group (P < 0.01). CONCLUSION: Early and short -- term use of antibiotics with broad spectrum in severely burned patients could effectively prevent postburn severe infection and lower down the incidence of internal organ complications.

Adolescent↗
PubMed2001

[Apoptosis of bone marrow cells aplastic anemia patients treated with cyclosporin A].

OBJECTIVE: To evaluate the effects of cyclosporin A (CsA) on the apoptosis of bone marrow cells of aplastic anemia (AA) patients. METHODS: The apoptosis of and Fas antigen expression on the bone marrow mononuclear cells (MNC) in 25 AA patients and 10 normal controls were assayed by TUNEL and FACS, respectively. RESULT: The percentage of CD(34)(+) cells was decreased significantly in AA patients than in normal controls (P < 0.05), and so did the percentage of CD(34)(+)Fas(+) cells (P < 0.05). The percentage of apoptotic cells in AA patients was higher than that of controls (P < 0.01). After the patients were treated with CsA for 2 months, the percentage of apoptotic cells was decreased (P < 0.01). The percentage of CD(34)(+)Fas(+) cells was positively correlated with that of apoptotic cells in AA patients. CONCLUSION: Fas is involved in the apoptosis of CD(34)(+) cells of AA patients. CsA could reduce the percentage of apoptosis of bone marrow cells in AA patients.

Adolescent↗
PubMed2001

[The diagnostic value of platelet glycoprotein-specific autoantibody detection in autoimmune thrombocytopenic purpura].

OBJECTIVE: To evaluate the clinical significance of platelet glycoprotein-specific autoantibody detection and platelet-associated IgG (PAIgG) measurement in the differential diagnosis between autoimmune thrombocytopenia and nonimmune thrombocytopenias. METHODS: Anti- GP II b/III a and anti-GP I b/IX autoantibodies were detected by a modified monoclonal antibody immobilization of platelet antigens assay (modified MAIPA), and PAIgG by competitive ELISA. RESULTS: Comparing with the measurement of PAIgG, the GP-specific autoantibody assay was less sensitive but much more specific for the diagnosis of autoimmune thrombocytopenia. CONCLUSION: The platelet GP-specific autoantibody detection is considerably better than PAIgG measurement in discriminating immune from nonimmune thrombocytopenia.

Adolescent↗
PubMed2001

Cyclohexylamino-demethoxy-hypocrellin B and photodynamic therapy decreases human cancer in vitro.

2-Cyclohexylamino-2-demethoxy-hypocrellin B (CHAHB) is a new photosensitizer synthesized by the mild reaction between hypocrellin B (HB) and cyclohexylamine, in which the peri-hydroxylated perylenequinone structure of the parent HB is preserved and the photoresponse is enhanced markedly. Electron paramagnetic resonance (EPR) spin trapping measurements and 9,10-diphenylanthracene (DPA) bleaching studies were employed to investigate the photodynamic action of CHAHB in the presence of oxygen. Singlet oxygen ((1)O2) and superoxide anion radical (O2*-) generated by illuminating CHAHB in aerobic solution have been observed. Compared with HB, CHAHB distinctly enhanced the O2(*-)-generating abilities, although (1)O2-generating abilities were lowered. The photodynamic action of CHAHB in the therapy of cancer was investigated in vitro. The results in vitro revealed a much more significant decrease in cancer cell growth than with HB. Laser or dye alone had no effect, indicating that intratumor CHAHB and laser therapy may prove useful in unresectable cancer.

Cell Line↗
PubMed2001

[Researches on morphology and anatomy of root system of Dendrobium nobile Lindl].

OBJECTIVE: To understand the morphological and anatomical characteristics of Dendrobium nobile so as to provide scientific basis for its domestication and cultivation. METHOD: The root's morphological development and interior structure were investigated. RESULT AND CONCLUSION: Dendrobium has peculiar structure which determines that this plant requires a growing environment with high water and air ventilation properties.

Dendrobium↗
PubMed2001

[Expression of Fas and Fas ligand in lesions of patients with discoid lupus erythematosus].

OBJECTIVE: To study the relation of apoptosis and pathogenesis of lupus erythematosus. METHODS: Expressions of Fas and Fas ligand(FasL) were detected in 30 lesions of discoid lupus erythematosus(DLE) and 5 skin specimens from healthy controls by immunohistochemical staining. RESULTS: Fas and FasL were positively expressed in most epidermal keratinocytes, infiltrating lymphocytes around blood vessels and appendages, and Fas was positively expressed in a few sweat ducts and hair follicles. Fas and FasL expressions were weakly positive or negative in healthy controls. CONCLUSION: Apoptosis induced by Fas, FasL pathway may be related to the pathogenesis of lupus erythematosus.

Adult↗
PubMed2001

[An experimental study on the implantation of a biomaterial with electro-activity for replacement of hard tissue in bone].

OBJECTIVE: To assess the effects of a piezoelectric biological ceramic on osteogenesis. METHODS: Hydroxyapatite (HA) and piezoelectric biological ceramics (hydroxyapatite and barium titanate, HABT) were implanted in the jawbones of 5 dogs, and for sample collection, the dogs were killed separately at 1 week, 2 weeks, 1 month, 2 months and 3 months after implantation. The samples from a rhesus monkey and a blank control were collected 34 months after implantation. The implanted samples and surrounding tissues were subjected to histological observations using light microscopy (LM) and scanning electronmicroscopy (SEM) were made. RESULTS: Compared with the control groups, the HABTs promoted osteogenesis significantly. One week after implantation, new bone tissues were found on the surface vertical to the longitudinal direction of HABT; more bone tissues were found after 2 weeks. HABTs induced the bone tissues to arrange orderly. After two years and ten months of implantation, the piezoelectric bioceramic and bone became monolithic, and the structure of bone was normal. CONCLUSION: HABTs could promote osteogenesis.

Animals↗
PubMed2001

[Effect of total flavones of Hippophae rhamnoides L. on sympathetic activity in hypertension].

OBJECTIVE: To investigate the effect of total flavones of hippophae rhamnoides L (TFH) on sympathetic nerve activity of essential hypertensive patients and to determine whether TFH possesses inhibitory effect on sympathetic activity after supine isometric exercise. METHODS: Heart rate, blood pressure and plasma catecholamines of the patients were measured before and after treatment. 88 patients were randomly divided into TFH group (n = 35), calcium antagonist nifedipine (n = 33) and verapamil ER (n = 20) group. RESULTS: It was shown after 8 weeks of treatment that TFH did not alter the rest heart rate and plasma catecholamine concentration in the patients (P > 0.05). In contrast, nifedipine produced an increase of noradrenaline and adrenaline level(P < 0.01). Isometric exercise may significantly increase the heart rate, blood pressure and plasma catecholamine concentration in hypertensive patients. In TFH group, exercise did not increase the heart rate, blood pressure and plasma catecholamine concentration after treatment. In nifedipine group, however, the same isometric exercise significantly increased the heart rate, blood pressure and noradrenaline concentration after treatment (P < 0.01). In verapamil group, the plasma catecholamine concentration did not change after treatment, but it was significantly increased after isometric exercise. CONCLUSIONS: The results suggest that TFH does not alter the sympathetic activity in treatment of hypertension and the inhibitory effect of TFH on sympathetic activity after supine isometric exercise may provide clinical benefits.

Aged↗