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Biomedical subjects

X Huang

Publications and source records attributed to X Huang.

At least 361 records · Page 20Linked to original sources
PubMed1999

[Changes of PMN apoptosis in rabbits after burn].

OBJECTIVES: To study the dynamic changes of apoptosis of PMN from rabbits in the early stage after severe burn in vivo and investigate the effect of burn serum and wound exudate on PMN apoptosis in vitro. METHODS: 12 rabbits were randomly divided into 2 groups: control group (37 degrees C) and burn group (95 degrees C, 15 sec, III degrees 30% TBSA). Whole blood from the burn group at 0, 4, 8, 12, 24 h postburn was stained with acridine orange/ethidium bromide (AO + EB), and observed under UV microscopy. PMNs were isolated from both groups and cultured for 24 h (37 degrees C, 5% CO(2)) with normal serum (NS), burn serum (BS), and subeschar tissue fluid (STF) respectively. Morphological assessment and quantitation of apoptosis were performed with AO + EB stain and flow cytometric analysis. RESULTS: The number of apoptotic PMN in vivo decreased in the early stage postburn. In the BS + PMN group and STF + PMN group, the percentage of apoptotic PMN reduced (vs NS + PMN group, P < 0.05) and the specific DNA "ladder" pattern for apoptotic cells was not detected by agarose gel electrophoresis. We observed that both burn serum and STF could similarly suppressed PMN apoptosis while there was no significant difference between NS + normal PMN group and NS + burn PMN group. CONCLUSIONS: Apoptosis is inhibited in PMN from rabbits postburn in the early stage. Both burn serum and STF from rabbits postburn can inhibit PMN apoptosis in vitro.

Animals↗
PubMed1999

[Time trend of mortality rates of cerebrovascular diseases in Hong Kong].

OBJECTIVE: To describe the time trend of mortality rates of cerebrovascular diseases (CVD) in Hong Kong for the period of 1976 to 1995, and to compare them with those in the more developed countries around the world. METHODS: Mortality rates of CVD were standardized directly using world standard population in 1961. Annual percent changes of mortality rates of CVD were estimated with a non-linear regression. Birth-cohort analysis was carried out at an interval of five-year of age to compare their age-specific mortality rates of CVD in different birth cohorts. Time trend of cause-specific mortality rates of CVD both in males and females was fitted with a simple linear regression model. RESULTS: Considerable downward trend of CVD mortality was observed during the past twenty years. Mortality rates among men and women decreased by 50.96% and 37.85% in 1995, as compared to those in 1976, respectively. Although in general, a greater trend in CVD mortality was observed during the last 10 years, as compared with that in the previous 10 years, an annual increase in CVD mortality of 1.34% was found among males aged 35 to 44 years during the latter 10 years. CVD mortality for both males and females decreased steadily by 1% per year. CVD mortality for females will catch up with that for males by the year of 2013, if such a trend continues. Birth-cohort analysis showed that those born more recently at the same age-group had lower mortality of CVD (except for those born after 1955). Data from hospital admission showed that improvement in the treatment for CVD could have contributed partly to the decrease in its mortality. CONCLUSION: Time trend of mortality of CVD in Hong Kong was similar to that in many other economically developed areas around the world.

Adult↗
PubMed1999

[Construction of Streptococcus mutans surface protein antigen eukaryotic expression vector pcDNA3-PAc. II. Testified efficiency of repeated using glass fiber chromatographic column].

OBJECTIVE: To explore one method getting highly purified plasmid DNA and costing low. METHODS: According to principle of extraction and purification plasmid DNA of glass fiber chromatographic column, its operation sequence was improved so that disposable glass fiber chromatographic column could be used repeatedly. The concentration and purity of plasmid DNA obtained by 12 times repeated using glass fiber chromatographic column were determined by spectrophotometry. Moreover, Those plasmid DNA obtained were tested by restriction enzyme and agarose gel electrophoresis, Ligation in vitro and transformation test. RESULTS: 12 times repeated use of glass fiber chromatographic column made no significant difference to the concentration and purity of obtained plasmid DNA (P < 0.05), and plasmid DNA was completely digested by restriction enzyme. The digested fragments were well ligated together by the action of T4 DNA Ligase in ATP ligating buffer in vitro and ligated DNA was well transformed into E. coli. CONCLUSION: Repeated use glass fiber chromatographic column can obtain a lot of highly purified plasmid DNA and cost is low. Digestion, ligation and transformation of those plasmid DNA are not affected. The results may be significant in molecular cloning and study of gene vaccination.

Antigens, Surface↗
PubMed1999

[A comparative study of different neuromuscular pedicle embedded in posterior cricoarytenoid muscle].

OBJECTIVE: To compare the results and effect of different neuromuscular pedicle (NMP) embedded in posterior cricoarytenoid muscle. METHOD: In 22 dogs, combined vocal cord paralysis models were made. The first group (10 dogs) were embedded by sternohyoid muscle pedicle of ansa cervicalis, the second (10 dogs), accessory sternocleidomastoid neuromuscular pedicle, the third (2 dogs), control group. RESULT: Evaluation was possible in 19 dogs. Reinnervation of the left posterior cricoarytenoid muscle occurred in 17 dogs following NMP. Return of spontaneous abduction in the operated side with NMP was noted after 4 months postoperatively. There was little difference between the two NMP groups. CONCLUSION: NMP was successful to reinnervate the posterior cricoarytenoid muscle.

Accessory Nerve↗
PubMed1999

[The curative effect of daphnlin spray on treating rhinitis].

OBJECTIVE: To observe the effect of Daphnlin spray on decongesting rhinocleisis and to search effective drugs for treating rhinitis. METHOD: 105 patients collected from chronic simple rhinitis, chronic hypertrophic rhinitis and perennial allergic rhinitis were treated with daphnlin spray (daphnlin group) or ephedrine spray (ephedrine group). RESULT: The total efficiency of daphnlin group in treating rhinitis above is 90.9% and that of ephedrine group (69.3%) in 1 minute and for ephedrine group is mostly (68.7%) between 1 to 3 minutes. The keeping curative effect time for daphnlin spray is mostly (70.4%) above 5 hours and for ephedrine spray is mostly (71.8%) in 3 hours. After a week, the nasal resistances are difference between daphnlin group and ephedrine group. CONCLUSION: Daphnlin spray is better than ephedrine spray in decongesting rhinocleisis, keeping curative effect and in safety, so daphnli is one kind of effective drugs in treating rhinitis.

Administration, Inhalation↗
PubMed1999

[Establishment of animal model for ischemic facial palsy in rat].

OBJECTIVE: In order to establish animal model for ischemic facial nerve palsy in rats and to observe the intrinsic vascular network of facial nerve in the fallopian canal. METHOD: Selective vascular embolization of the external carotid artery was performed in rats. The animals were killed at 1 and 30 days after operation respectively. 10% gelatin solution with fluorescent dye were injected into their left ventricles. The changes intrinsic vascular network were observed under inverted fluorescent microscopy. RESULT: Facial palsy was presented within 5 to 15 min following arterial embolization, the intrinsic capillaries of facial nerve appeared to be thinner and some of them were blocked by microspheres, especially in the labyrinthine segment. Facial palsy almost recovered after 30 days postoperatively. The capillaries returned to be almost normal shape and only few of them were thinner. CONCLUSION: The establishment of animal model for ischemic facial palsy will make contribution to experimental research and clinical treatment for facial palsy.

Animals↗
PubMed1999

[The rebound of nasal resistance after decongestant used in nose].

OBJECTIVE: To investigate the effect of decongestant on nasal resistance so as to provide theories for studing rhinitis medicamentosa. METHOD: The changes of nasal blockage in 92 cases of acute rhinitis and chronic rhinitis after using decongestants were recorded, and the nasal resistance in 39 cases were measured by active anterior rhinomanometry. RESULT: According to the diseases and decongestants used, the percentage of nasal resistance rebound were 63.5%, 31.2%, 32.2%, 8.6% in 4 groups of investigated patients and 50%, 20%, 75% in 3 groups of measured patients respectively. CONCLUSION: Decongestants can cause the rebound of nasal resistance, which related to the diseases and the decongestants used. The mechanism may be that the factors dilating the vasa in nasal mucosa are activated.

Adolescent↗
PubMed1999

[A study of time-dependent blood flow distribution in ischemic myocardium and its dependence on perfusion pressure with modeling and emulation].

A mathematical model was proposed for studying the time-dependent blood flow distribution in ischemic myocardium with different developments of collateral circulation. The model includes the blood perfusion of normal myocardium and ischemic myocardium. There are three classical myocardial vascular nets in each part and each net is represented by a branch of time-dependent nonlinear resistance and compliance. Experimentally measured aortic pressure and left ventricular pressure from six male dogs were taken as input data for emulation. The results demonstrate that raising perfusion pressure with external counterpulsation can improve the blood perfusion condition in ischemic myocardium.

Animals↗
PubMed1999

[Functional analysis of human A gamma-globin gene promoter with-173 T-->C mutation].

OBJECTIVE: To investigate the effect of the human A gamma-globin gene-173 T-->C mutation on the binding of transacting factors to the promoter and the activity of the promoter. METHODS: Electrophoretic mobility shift assay and transient transfection assay were used in this study. RESULTS: The A gamma-globin gene-173 T-->C mutation decreased the affinity of GATA-1 to the mutant promoter fragment (-201(-)-158) 96% (P < 0.01) and the binding of Oct-1 to the same DNA fragment 55% (P < 0.05). The activity of the mutant promoter was 2-fold (P < 0.05) as strong as that of the normal one in MELGM979 cells. The mutant and the normal promoters exhibited basically same activities in K562 and Hela cells. CONCLUSIONS: The -173 T-->C mutation decreased dramatically the binding of GATA-1, implicating that GA-TA-1 may act as a negative regulator of A gamma-globin gene in adults. The -173 T-->C mutation may enhance the activity of A gamma-globin gene promoter in the adult erythroid cell environment.

Adult↗
PubMed1999

[Soluble IL-2 receptor levels in patients with Graves' ophthalmopathy].

OBJECTIVE: Soluble interleukin-2 receptor (sIL-2R) levels in sera with Graves' ophthmopathy was investigated for its relationship to the clinical manifestations and therapeutic effects. METHODS: sIL-2R levels were measured in sera of 41 patients with Graves' ophthalmopathy which had not yet received specific treatment for their ophthalmopathy and euthyroid during the entire study period and 49 normal subjects. RESULTS: In untreated patients, the mean levels of sIL-2R were significantly higher than those in the normal subjects (P < 0.001). There was no difference in the levels of sIL-2R between patients with hyperthyriod Graves' ophthalmopathy and those with enthyroid Graves' ophthalmopathy. The levels of sIL-2R in patients with response for corticosteoids treatment were significantly higher than that in patients with non-response for corticosteoids treatment (P < 0.001), but there were no differences between the each class present in the NOSPECS classification of ophthalmopathy. 12 patients with response for corticosreoids had lower sIL-2R levels After 3-month treatment than pertreatment. CONCLUSION: These results suggested that elevated sIL-2R levels in patients with Graves' ophthalmopathy may be derived from ophthalmopathy itself, e.g. intra-orbital activated lymphocytes, and serve as a useful parameter to evaluate clinical activity score and predict value of corticosteoids treatment outcome.

Adult↗
PubMed1999

Expression of ICAM-1 and LFA-1 molecules in relation to renal allograft rejection in rats.

OBJECTIVE: The purpose of this study was to assess the renal graft expression of ICAM-1 (intercellular adhesion molecule-1) and LFA-1 (lymphocyte function-associated antigen-1) molecule with relation to graft rejection. METHODS: Rat kidney transplantation was performed according to the procedure of Kamada with some modification. Experimental rats were divided into 5 groups. The survival time of recipient rats and function of grafts after renal transplantation were observed. The sections of renal graft were stained for monoclonal antibody ICAM-1 and LFA-1, and then quantification of ICAM-1 and LFA-1 expression was accomplished by computer image analysis. RESULTS: ICAM-1 and LFA-1 increased significantly in the renal allograft rejection group as compared with the non-rejection groups (P<0.05). CONCLUSION: Both biopsy of renal graft and monitoring of ICAM-1 and LFA-1 are useful tools in diagnosing and treating acute rejection.

Animals↗
PubMed1999

[New solution of simultaneous equations in spectrophotometry for the determination of aspirin and acetaminophen in xiaoer tuishao pian].

The contents of aspirin and acetaminophen in xiaoer tuishao pian were determined by using the new solution of simultaneous equations without any preliminary separation. The average recoveries and variation coefficients of the analysis are 99.95% and 1.74% for aspirin and 100.1% and 0.93% for acetaminophen, respectively. The method was simple, rapid and accurate.

Acetaminophen↗
PubMed1999

[Monitoring and elimination of sulfur dioxide and nitrogen dioxide by passive sampling method].

The concentration of atmospheric pollutants, sulfur dioxide and nitrogen dioxide, were monitored by passive sampler with spectrophotometric determination method. The results were compared with active sampling method. It was found that the two methods got the same results. The adsorption of sulfur dioxide and nitrogen dioxide by sorbent-saturated filter paper was also studied.

Air Pollutants↗
PubMed1999

[Determination of sulfur dioxide by fluorometric analysis].

A method to determine the concentration of atmospheric pollutant, sulfur dioxide, was studied by fluorophotometric method. The composition and concentration of reaction solution were optimized. This method can be developed to be a fibre optic fluorometric method for routine monitoring.

Air Pollutants↗
PubMed1998

Loss of atm radiosensitizes multiple p53 null tissues.

An unusual clinical finding in ataxia-telangiectasia, a human disorder caused by mutations in atm, is exquisite sensitivity to gamma irradiation. By contrast, homozygous deletion of p53 is marked by radiation resistance in certain tissue compartments. Previous studies (A. J. Levine, Cell, 88: 323-331, 1997) have shown that, in vitro, p53-deficient bone marrow cells are resistant to gamma irradiation. Furthermore, the gastrointestinal radiosensitization engendered by the loss of atm has recently been shown (C. H. Westphal et al., Nat. Genet., 16: 397-401, 1997) to be independent of p53. Expanding on previous work, we have looked at in vivo bone marrow resistance in p53-deficient mice. Our results indicate that inbred FVB strain p53 null mice survive lethal irradiation doses because of bone marrow resistance. Moreover, the deletion of atm radiosensitizes even p53 null bone marrow and mouse embryonic fibroblast cells. The results presented here argue that the loss of atm radiosensitizes multiple tissues in a p53-independent manner. Hence, functional inhibition of atm in p53 null and p53 wild-type human tumors may be a useful adjunct to gamma irradiation-based antitumor therapy.

Animals↗
PubMed1998

The fibronectin type III domain as a scaffold for novel binding proteins.

The fibronectin type III domain (FN3) is a small autonomous folding unit which occurs in many animal proteins involving in ligand binding. The beta-sandwich structure of FN3 closely resembles that of immunoglobulin domains. We have prepared a phage display library of FN3 in which residues in two surface loops were randomized. We have selected mutant FN3s which bind to a test ligand, ubiquitin, with significant affinities, while the wild-type FN3 shows no measurable affinity. A dominant clone was expressed as a soluble protein and its properties were investigated in detail. Heteronuclear NMR characterization revealed that the selected mutant protein retains the global fold of FN3. It also has a modest conformational stability despite mutations at 12 out of 94 residues. These results clearly show the potential of FN3 as a scaffold for engineering novel binding proteins.

Amino Acid Sequence↗
PubMed1998

[The use of microsatellite DNA markers for distinguishing metastatic tumor cells].

OBJECTIVE: To study the genetic stability and to establish a method for detection of micrometastasis using microsatellite DNA in human breast cancer xenograft in nude mice. METHODS: Fresh tissue of human breast cancer was xenotransplanted in nude mice or thotopically. Genomic DNA extracted from tissues of human breast cancer, xenotransplanted tumors and metastatic foci in nude mice were PCR amplified at three microsatellite loci (D14S68, D18S69, D20S199) and were analysed by electrophoresis and silver stain on PAGE. RESULTS Microsatellite DNA in genome of the xenotransplanted tumors and metastatic foci in nude mice were identical with that of the human breast cancer. CONCLUSION: This study has demonstrated in nude mice the xenotransplanted tumors and metastatic foci that originated from human breast cancer. The genetic stability in human breast cancer is evident in the processes of xenotransplantation, serial passages in nude mice, metastasis and in vitro culture. This method is sensitive and specific for the discrimination of metastatic tumor cells.

Animals↗