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Biomedical subjects

G Xiao

Publications and source records attributed to G Xiao.

At least 109 records · Page 6Linked to original sources
PubMed1996

[A study of the expression and localization of tumor necrosis factor mRNA in small intestine of rats after severe burn].

In this study, the dot blotting and in situ hybridization, collaborated with determination of contents of endotoxin and TNF in plasma, were used to study the expression and localization of TNF mRNA in the intestine. The results showed that, the expression of TNF mRNA in the small intestine increased rapidly and reached maximum at 6 h postburn, being 5.56 times higher than that of normal control. The TNF mRNA-producing cells in normal animal were mononuclear phagocytes located in lamina propria. After burn, the number of positive cells in lamina propria increased significantly, and the TNF gene-expressing cells were vascular endothelium. Many positive cells were found in the crypts of the intestine. It suggested that the expression of TNF correlated well with bacterial translocation in the early stage of burn. The mononuclear phagocytes and endothelial cells located in lamina propria and interstitial tissue were the chief TNF mRNA-producing cells in the intestine. The overproduction of TNF could provoke microvascular injury or induce the production of oxygen free radical to damage the gut mucosal barrier.

Animals↗
PubMed1996

[Protective effect of lipid A monoclonal antibody against burn sepsis in rats].

A lipid A monoclonal antibody(mAb) was prepared and it was used to study its protective effect against burn sepsis. Wistar rats were inflicted with 30% TBSA third degress burn, and they were given LPS to mimic early sepsis after burn. The rats were divided randomly into burn with LPS, monoclonal antibody treatment, and control groups. The levels of endotoxin, tumor necrosis factor, light and electron microscopic studies of the morphological changes in the liver were studied. The results showed that the anti-lipid A monoclonal antibody demonstrated capacity to cross-react with several Gram-negative bacteria and their endotoxins. The mAb improved the survival rate of rats and decreased the levels of endotoxin and TNF as well as the liver damage significantly.

Animals↗
PubMed1996

[Changes of circulating Lps and cytokines in burned patients after anti-endotoxin therapy].

OBJECTIVE: Endotoxin as the inciting agent of cytokines and other mediators, whose high level expression correlates with the septic shock and MOF, has been the one of leading causes of death in ICU. METHODS: For treating sepsis and MOF caused by endotoxin, the anti-lipid A of LPS antibody was used, 19 burned patients whose TBSA varied from 50% to 100% were divided into anti-LPS treatment group and nontreated group. RESULTS: The levels of serum endotoxin, IL-6, IL-8, TNF and soluble IL-2R were lower obviously in patients of anti-LPS group than those of nontreated group (P < 0.05). CONCLUSION: Clinical study surggests that anti-lipid A of LPS antibody can act as an therapeutic agent against gram-negative bacterin infection in burned patients.

Adult↗
PubMed1996

[A study on changes and its mechanisms of intestinal mucosal permeability after severe burn].

The changes in the intestinal mucosal permeability were observed by quantitatively assessing plasma to luminal clearance of 99mTc-labeled DTPA, and the influence of platelet activating factor (PAF) on it was investigated. The results showed that intestinal permeability was significantly elevated after severe burn and was positively correlated with increase in PAF in the intestinal tissue (r = 0.94, P < 0.01). PAF antagonist therapy could significantly attenuate postburn intestinal mucosal permeability. It is concluded that PAF is one of the important factors causing increased intestinal permeability after severe burn.

Animals↗
PubMed1995

Colocalization of the rat homolog of the von Hippel Lindau (Vhl) gene and the plasma membrane Ca++ transporting ATPase isoform 2 (Atp2b2) gene to rat chromosome bands 4q41.3-->42.1.

Using fluorescence in situ hybridization, we localized the rat homolog of the von Hippel-Lindau gene (Vhl) to rat chromosome band 4q41.3-->q42.1. We also mapped the gene encoding the plasma membrane Ca(++)-transporting ATPase isoform 2(Atp2b2) to the same chromosome subregion. These two genes together with Raf1 appear to be members of a large syntenic gene cluster that maps to human chromosome bands 3p25-->p26, mouse chromosome bands 6 C3-->E, and rat chromosome bands 4q41-->q42. Cytogenetic analysis of NRK 52E cells derived from immortalized normal rat kidney epithelial cells revealed an inverted duplication of the region containing this gene cluster.

Animals↗
PubMed1995

[Establishment of hybridoma lines and protective study of monoclonal antibodies against lipid A of endotoxins].

For developing monoclonal antibodies (MAb) that bound to lipid A of the LPS molecule, we established several hybridomas cell lines by fusion of SP2/0 and spleen cells from BALB/c mice immunized by J5 mutant strain of E. coli 0111:B4. Each MAb exhibited a high titer by ELISA assay. Six of MAb were of immunoglobulin G isotype and another one immunoglobulin M. All of these MAb demonstrated different capacity to cross-react with several gram-negative bacteria and their endotoxins. Among them, 9G6 MAb improved the survival rate of mice significantly when administered 2 hours before the challenge by pseudomonas A and E. coli. These findings suggest that MAb will probably be useful in the treatment of sepsis caused by a wide variety of gram-negative bacteria.

Animals↗
PubMed1995

[The roles of platelet activating factor in intestinal mucosal barrier injury after burn].

In order to investigate the roles of platelet activating factor (PAF) in postburn intestinal barrier injury, the changes in intestinal mucosal potential difference (PD), intestinal PAF, Phospholipase A2 (PLA2), myeloperoxidase (MPO) and malondialdehyde (MDA) were measured in a model of rats with 30% TBSA III degrees burns. The results showed that the intestinal PAF level was significantly elevated after severe burn and was negatively correlated with the decrease of intestinal mucosal PD (r = -0.94, P < 0.01). PAF antagonist WEB 2170 treatment could significantly inhibite the increase of PAF in intestinal tissue, enhance intestinal mucosal PD, attenuate the levels of PLA2, MPO and MDA in intestinal tissue, and alleviate the pathological changes in ileal mucosa, compared with the burn group. The results suggest that PAF is an important factor causing postburn intestinal mucosal barrier injury, and activation of leukocyte and PLA2 as well as the release of superoxide are important intermediate mechanisms for PAF leading to intestinal mucosal injury.

Animals↗
PubMed1995

[Experimental study and clinical application of rapid diagnosis of systemic candida albicans infection in burns by polymerase chain reaction].

For rapid diagnosis of systemic candidiasis, the polymerase chain reaction (PCR) was used to amplify a segment of Candida albican DNA coding for the cytochrome P450 L1 A1 in vitro. The technique provided unambiguous evidence of the presence of Candida albicans in as short as 8 hours with a detection threshold of 20 organisms. 200 blood and 120 urine specimens were collected from thirty rabbits with burn and candidiasis. Specimens of blood (n = 6), urine (n = 6), sputum (n = 7) and wound exudate (n = 7) were also collected from eight serious burn patients. PCR technique was used in all the specimens, and the result was compared with conventional fungus culture. It was shown that: (1) The positive detection rate of Candida by PCR was significantly higher than by culture for blood specimens (P < 0.01) and serial specimens of urine (P < 0.05) in infected burn animals. The clinical specimens showed the same results; (2) In evaluating diagnostic value of PCR for systemic Candida albicans infection, it was found that sensitivity, accuracy and negative prediction rate were superior to the conventional culture method. These results suggest that PCR technic may provide a rapid sensitive and specific means for the diagnosis of systemic Candida albicans infection. In addition, it may be helpful in the evaluation of therapeutic response or recurrence of infection.

Adult↗
PubMed1995

[An experimental study of the expression and localization of tumor necrosis factor mRNA in liver of rats with severe burn].

In situ hybridization was used to study the expression and localization of tumor necrosis factor (TNF) mRNA in liver of rats after burn. The results showed that the Kupffer cells expressed TNF mRNA in normal rats. After burn, the number of positive expression cells increased quickly, the expression reached max-mum at 6h postburn, and there were no significantly different with normal at 24h postburn. The dynamic changes of number of TNF mRNA producing cells was similar to that of the portal plasma endotoxin level. Kupffer cells located in sinusoid surrounding portal vein expressed TNF mRNA especially at 6h-12h postburn. Also the sinusoid endothlial cells and infiltrative inflammation cells surrounding portal vein were the TNF mRNA-producing cells, this changes appeared significantly at 12-24h postburn. The results suggested that the endotoxin originated from gut may be the principal stimulator for expression of TNF mRNA. The expression of endothlial cells and neutrophils suggested that these cells had been activated. So the endothlium, neutrophils and Kupffer cell play an important role in the pathogenesis of the endotoxin-induced live injury.

Animals↗