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Biomedical subjects

Z Shi

Publications and source records attributed to Z Shi.

At least 73 records · Page 4Linked to original sources
PubMed2000

[The significance of the expressions of lipopolysaccharide binding protein mRNA and lipopolysaccharide receptor CD14 mRNA in the liver of burned rat].

OBJECTIVE: To explore the significance and the correlation between enteric endotoxin translocation and hepatic endotoxin -- sensitivity -- enhancing system--lipopolysaccharide -- binding protein (LBP)/lipopolysaccharide receptor CD14 (LBP/CD14) after burn. METHODS: Wistar rats subjected to 35% III degree burn were employed as the model. The rats were randomly divided into three groups: i.e. normal control (C, n = 8) group, thermal injury (T, n = 10) group and recombinant bactericidal/permeability -- increasing protein (rBPI(21)) treatment (R, n = 6) group. The rats in T and R groups were sacrificed at 12 postburn hour (PBH) and the liver tissue was collected for the detection of the mRNA expressions of LBP, CD14 and tumor necrosis factor (TNFalpha) and blood samples collected for hepatic functional indices. RESULTS: The hepatic endotoxin content increased significantly postburn (P < 0.01), and the expressions of LBP/CD14 and TNFalpha mRNA in liver tissue increased obviously. However the use of rBPI(21) could evidently lower hepatic endotoxin content and inhibit the expression of tissue LBP/CD14 and TNFalpha. In addition, rBPI(21) could also significantly decrease serum level of glutamic -- pyruvic transaminase (ALT) (P < 0.01). CONCLUSION: Aggregation of endotoxin in liver due to postburn translocation might obviously stimulate the expression of LBP/CD14 mRNA locally. The up -- regulation of the expression of LBP/CD14 might be the principle molecular basis enhandced activity of translocated endotoxin on inflammatory cells.

Acute-Phase Proteins↗
PubMed2000

[Clinical retrospect on autoimplantation of traumatically dislocated teeth].

OBJECTIVE: A total of 48 cases with autoimplantation of traumatically dislocated teeth were retro spected as clinical references. METHODS: Several indexes were recorded in details, for instance, tooth dislocation time, operation and postoperative management and patients were followed up periodically. RESULTS: Tooth dislocating intervals from trauma to implantation were from 0.5 to 48 hours. Therapeutic effectiveness was graded as perfect in 37 teeth (61.7%), good in 18 (30.0%) and poor in 5 teeth (8.3%), in which 3 teeth were extracted within 1 year. Three-year success rate was 83.0%, and five-year success rate was 61.7%. It was judged 20 teeth being as periodontal membranous healing, 35 bony healing and 5 fibrous healing. Pulpal vitality tests were positive in 23 and negative in 37 teeth. Root canal therapies were conducted in 20 teeth. CONCLUSION: Carefully protecting periodontal membranes, keeping good fixation, preventing from infection and avoiding occlusal injuries are important factors for successful implantation of the dislocated teeth. Periodical examination would be benefit to the long term prognosis. The correct methods for dislocated tooth preservation should be treated as the important part of health education.

Adolescent↗
PubMed1999

Bcl-2 plays a key role instead of mdr1 in the resistance to hexadecylphosphocholine in human epidermoid tumor cell line KB.

We induced tolerance to hexadecylphosphocholine (HePC) in the human epidermoid tumor cell line, KB. After 70 weeks of adaptation, the IC50 of HePC in the resistant cells KBr was 32-fold higher than in parental KB cells, and they were 30-fold more resistant to another ether lipid analogue, ET-18-OCH3. The KBr cells also showed cross-resistance to vincristine and colchicine while remaining sensitive to other chemotherapy agents. RT-PCR assays showed that expression of the multidrug resistance gene (MDR1) was positive in KBr cells, whereas the expression of GST-pi (glutathione S-transferase pi) and MRP (multidrug resistance protein) was undetectable in KBr cells. Both an immunocytochemistry test and Western blot analysis indicated that the expression of bcl-2 in KBr cells was strongly positive, while it was only mildly expressed in KB cells. Verapamil could not reverse the resistance of KBr to HePC although it is a well-known reversing agent against MDR1. Our results suggest that bcl-2 instead of MDR1 plays a major role in the resistance of KBr cells.

Antineoplastic Agents↗
PubMed1999

DNA-based non-invasive vaccination onto the skin.

Non-invasive vaccination onto the skin (NIVS) could improve vaccination programs because the procedure requires no specially trained personnel and may eliminate many problems associated with needle injections. There is also evidence that the efficacy of a skin-targeted vaccine may be optimal when the antigen is expressed within the outer layer that is in constant contact with potential pathogens. We report here that non-invasive gene delivery by pipetting adenovirus- or liposome-complexed plasmid DNA onto the outer layer of skin could achieve localized transgene expression within a restricted subset of skin in mice and the elicitation of an immune response against the protein encoded by the DNA. These results provide a proof of principle that NIVS may appear as a novel method for the administration of DNA-based vaccines.

Adenoviridae↗
PubMed1999

Growth hormone suppression of insulin-like growth factor binding protein-1 promoter activity.

Hepatic transcription of insulin-like growth factor binding protein-1 (IGFBP-1) is rapidly downregulated by growth hormone (GH) which is also known to induce expression of c-fos and c-jun. Co-expression of c-fos or c-jun in rat hepatocytes, individually or together, suppresses IGFBP-1 promoter activity by approximately 60%. When hepatic nuclear extracts from sham-operated, hypophysectomized (hypox) and GH-treated hypox rats were analyzed by DNase-1 footprinting, differences in the protection pattern were identified in three regions of the IGFBP-1 promoter. F1 corresponding to - 660 to - 640 bp showed acute changes in response to GH administration. In additional regions, F2 and F3, representing - 758 to - 748 bp and - 477 to - 447 bp, respectively, differences were apparent between nuclear extracts from the hypox and sham-operated rats. When F1 and F2 were removed by deletion of the region from - 824 to - 557 bp, the GH response was lost but suppression by co-expression of c-fos and c-jun was preserved. A putative AP-1 binding site was present in the F3 footprint region, however removal of F3 did not affect the GH responsiveness. These data indicate that several distinct sequences, other than the putative AP-1 site are involved in mediating the GH effects on IGFBP-1 transcription.

Animals↗
PubMed1999

EEG coherency II: experimental comparisons of multiple measures.

OBJECTIVE: A concentric spheres model was used in an earlier paper to estimate the effects of volume conduction, reference electrode and spatial filtering on different EEG coherence measures. EEG data are used here to verify theoretical predictions. METHODS: Three EEG data sets were: (1) 64 channel, recorded during 7 alternating periods of resting and mental calculation. (2) 128 channel, for comparison of eyes open versus eyes closed coherence. (3) 128 channel, recorded during deep sleep (stages 3 and 4) and REM. RESULTS: The directions of large scale (lobeal) coherency changes between brain states are relatively independent of coherence measure. However, coherence between specific electrode pairs is sensitive to method and frequency. Average reference and digitally linked mastoids provide reasonable semi-quantitative estimates of large-scale neocortical source coherence. Close bipolar, Laplacian, and dura image methods remove most reference electrode and volume conduction distortion, but may underestimate coherence by spatial filtering. CONCLUSION: Each EEG coherence method has its own potential sources of error and provides coherence estimates for different neural population sizes located in different locations. Thus, studies of coherence and brain state should include several different kinds of estimates to take full advantage of information in recorded signals.

Adolescent↗
PubMed1999

[Matched case-control study for detecting risk factors of breast cancer in women living in Chengdu].

OBJECTIVE: To detect the risk factors of breast cancer in women living in Chengdu in order to identify high risk population and to conduct proper interventions. METHODS: A matched case-control study was performed in 265 cases with breast cancer who lived in this area. RESULTS: In the univariate analysis, menarche to menopause period > or = 35 years, taking oral contraceptives, history of benign breast diseases, passive smoking, and syrup drinking are the statistically significant risk factors of breast cancer, whereas breast feeding and soybean food consumption are protective factors. Conditional logistic multivariate analysis revealed that history of benign breast diseases and passive smoking are risk factors while soybean food products and breast feeding are protective factors. CONCLUSION: The risk factors of breast cancer in women living in Chengdu are history of benign breast diseases and passive smoking.

Adolescent↗
PubMed1999

[The time course and tissue distribution of endotoxin in rats after thermal injury].

OBJECTIVE: To observe the time course and tissue distribution of endotoxin, and to evaluate the potential role of local endotoxin in mediating multiple organ damage following burns. METHODS: Wistar rats were subjected to a 35 percent full-thickness scald injury. They were grouped according to time of sacrifice: no burn, and 12, 24, 48, 72 hours postburn. Tissue specimens from liver, kidneys, lungs and intestine were aseptically harvested to determine tissue endotoxin levels. In addition, blood samples were obtained for measurement of organ function parameters. RESULTS: It was found that endotoxin levels in liver, spleen and lungs increased markedly after thermal injury, with the highest level in liver. Meanwhile, serum GPT, GOT, CK-MB levels, and pulmonary myeloperoxidase(MPO) activities markedly elevated after scald injury, reaching a maximum between 12 and 24 hours. Intestinal diamine oxidase(DAO) activities tended to decrease at various time points postburn. In addition, there were highly positive correlations between pulmonary endotoxin levels and MPO activities, and also between renal endotoxin levels and serum Cr values. CONCLUSION: Burn injury per se can result in gut-derived endotoxin translocation which is mainly distributed to the liver, spleen and lungs. Endotoxin accumulated in local sites may play an important role in mediating multiple organ damage secondary to major burns.

Animals↗
PubMed1999

[The effect of bactericidal/permeability-increasing protein on lipopolysaccharide-binding protein and lipopolysaccharide receptor CD14 mRNA expression in rats after thermal injury].

OBJECTIVE: To elucidate the possible mechanisms underlying beneficial effect of recombinant bactericidal/permeability-increasing protein (rBPI) on multiple organ damage secondary to major burns. METHODS: Wistar rats were subjected to a 35% full-thickness scald injury, and randomly divided into 3 groups: normal controls (n = 8), thermal injury (n = 21), and rBPI21 treatment (n = 12). In thermal injury and rBPI21 treatment groups, animals were sacrificed at 12 and 24 hours after burn, respectively. Tissue samples from liver, kidneys, lungs and intestine were collected to measure lipopolysaccharide-binding protein (LBP)/lipopolysaccharide receptor CD14 and tumor necrosis factor-alpha (TNF-alpha) mRNA expression. In addition, blood samples were obtained for measurement of organ function parameters. RESULTS: Treatment with rBPI21 could significantly decrease tissue LBP and CD14 mRNA expression in various organs (P < 0.05-0.01). Also, TNF-alpha mRNA expression in liver, kidneys and lungs were markedly inhibited by rBPI21 secondary to acute insults (P < 0.05-0.01). Moreover, in the rBPI21 treatment group, significant reduction in serum GPT levels and elevation in intestinal DAO activities were found compared to those in the thermal injury group (P < 0.05-0.01). CONCLUSIONS: Treatment with rBPI21 is effective in attenuating multiple organ damage resulted from gut origin endotoxin translocation after thermal injury, which might be associated with down-regulation effect of tissue LBP and CD14 gene expression by use of rBPI21.

Acute-Phase Proteins↗
PubMed1999

Effects of BRL 55 834 on allergen-induced bronchoconstriction and airway inflammation in sensitized guinea pigs.

OBJECTIVE: To investigate the effects of potassium channel activator on allergen-induced bronchoconstriction and airway inflammation and to discuss which role it plays in asthma therapy. METHODS: Airway insufflation pressure, examination of inflammatory cells in bronchial alveolar lavage fluid, analysis of airway pathology and airway Evans blue dye extravasation measurement were employed to detect airway resistance and airway inflammatory responses. RESULTS: [(3s, 4R)-3, 4-dihydro-2, 2-dimethyl-4-(2-oxopiperidin-l-yl)-6-pentafluoroethyl-2H-1-benzopyran-3-ol] (BRL) 55 834 (8 micrograms/kg) inhibited not only ovalbumin-induced airway insufflation pressure increase but also inflammatory cell infiltration (ICI) in sensitized guinea-pigs; moreover, it did not decrease blood pressure; in contrast to BRL 55 834, single dose of BRL 38 227 (200 micrograms/kg) and verapamil (0.5 mg/kg) had a little effect on ICI; single dose of aminophylline (25 mg/kg) and dexamethasone (1 mg/kg) could not inhibit ICI, but the former could inhibit airway insufflation increase; drugs, besides aminophylline, could reduce microvascular leakage; single dose of BRL 38 227, verapamil and dexamethasone had no inhibition of airway insufflation pressure; BRL 38 227 and verapamil decreased blood pressure markedly. CONCLUSIONS: Selective potassium channel activator BRL 55 834 not only decreases airway resistance, but also inhibit airway inflammation, and both of them are of benefit to asthma therapy.

Animals↗
PubMed1999

[Efficacy of transcatheter arterial infusion chemotherapy and transcatheter arterial embolization in 132 patients with primary hepatocellular carcinoma].

OBJECTIVE: To find out factors influencing efficacy of transcatheter arterial infusion chemotherapy (TAI) and transcatheter arterial embolization (TAE) for unresectable primary hepatocellular carcinoma. METHODS: From January 1993 to October 1997, 132 patients with unresectable primary hepatocellular carcinoma (HCC) received 597 intervention treatments. Of the 132 patients, 122 patients were given TAI plus TAE (92.4%), while the remaining 10 patients were given TAI alone (7.6%). RESULTS: The 1-, 2-, and 3-year overall survival rate was 81.8%, 36.4% and 18.2%, respectively. The clinical stage of the disease, the embolizing agents used and their dosage, formation of collateral circulation to the tumor and proper application of superselective hepatic arterial catheterization are factors affecting treatment efficacy. CONCLUSION: Adequately performed TAI and TAE can be routinely used for the treatment of unresectable liver cancer.

Adult↗
PubMed1999

[Gene expression of lipopolysaccharide receptor CD14 and tumor necrosis factor-alpha in rats after thermal injury].

OBJECTIVE: To investigate changes in lipopolysaccharide receptor CD14 and tumor necrosis factor-alpha (TNF-alpha) gene expression in vital organs, and their significance in the pathogenesis of systemic inflammation after burns. METHODS: Wistar rats were subjected to a 35 percent full-thickness scald injury, then sacrificed pre-burn, and postburn 12, 24, 48, 72 hours, respectively. Tissue samples from liver, kidney, lung and intestine were collected to measure CD14 and TNF-alpha mRNA expression. Peritoneal macrophages were harvested by peritoneal lavage to determine CD14 mRNA expression. RESULTS: CD14 mRNA expression increased markedly after thermal injury, peaking at both 12 and 48 hours. Likewise, CD14 mRNA levels were significantly up-regulated in peritoneal macrophages. Gene expression of TNF-alpha elevated markedly in liver, lungs, and kidneys after acute insults. Positive correlation was found between CD14 mRNA and TNF-alpha mRNA in liver, lung, and kidney tissues. CONCLUSIONS: Thermal injury per se can markedly up-regulate both CD14 and TNF-alpha gene expression in various organs. Excessive CD14 mRNA expression may enhance synthesis and release of TNF-alpha stimulated by endotoxin translocation, and the interaction between CD14 and TNF-alpha may play an important role in mediating multiple organ damage secondary to major burns.

Animals↗
PubMed1999

[Effects of high fluoride intake on the fluoride of femora, teeth and some biochemical indexes in rats].

In order to approach practicable indexes for assessing the effects of the products which are intended to be used to prevent endemic fluorosis, Wistar rats were fed with fluoridated water(50 mg/L) for four weeks. After only one week treated with fluoride, a higher activity of NAG(N-acetyl-beta-D-glucosaminidase) in urine, ChE(cholinesterase) in blood and increased urinary excretion of fluoride (compared with the control, P < 0.01) were observed, and these changes were lasted to the end of the fourth week of the study, but hydroxyproline in serum and urine had not been changed in both groups. After four weeks, the fluoride levels in the femora and teeth of fluoride treated group were ten times higher than that of the control group. According to the results, fluoride in bones and teeth must be taken as key indexes, the activities of NAG in urine and ChE in blood should be taken into consideration for assessing the effects of fluoride protagonist.

Acetylglucosaminidase↗
PubMed1999

[A follow-up study of anterior deciduous cross-bite].

OBJECTIVE: To determine the relationship between anterior deciduous crossbite and anterior permanent crossbite, Angle classification of malocclusion and class III jaw relationship through a follow-up study in community children. METHODS: A follow-up study was done six years later in 102 children who were out of 120 children having anterior deciduous crossbite detected in a survey of six years before. Other 102 children with normal occlusion of deciduous and permanent teeth were treated as the control group. RESULTS: There were 51 out of 102 cases developed anterior permanent crossbite. In comparison with the group with 1-2 anterior deciduous crossbite, the group with more than two neighboring anterior deciduous crossbite had more significant probability to turn into anterior permanent crossbite, OR = 6.8 (95% CI: 2.7-17.6). The patients with more than 2 neighboring anterior deciduous teeth crossbite had significantly more chance of developing Angle III malocclusion and class III jaw relationship than those in the control group and those with 1-2 anterior deciduous teeth crossbite. CONCLUSION: Clinical orthodontists should pay more attention to the patients with more than 2 neighboring anterior deciduous crossbite.

Adolescent↗
PubMed1999

[Analysis of physicochemical property and composition of fatty acid of almond oil].

Almond oil was extracted from almond and saponified with saturated KOH-methanol. The mixed fatty acids methylated by methanol-H2SO4(4:1, V/V). Methyl esters were extracted by ether and detected by gas chromatography. The major fatty acids in Taiyuan almond oil were found to be about 68% oleic acid (C18:1), 25% linoleic acid(C18:2), 4.6%-4.8% palmitic acid(C16:0) and a little of palmitoleic acid(C16:1), stearic acid(C18:0). A trace of arachidic acid(C20:0) was also found.

Chromatography, Gas↗
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↗