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Biomedical subjects

T Li

Publications and source records attributed to T Li.

At least 307 records · Page 17Linked to original sources

[Application of the time-series method to analyse the seasonal distribution of epidemic encephalitis B incidence in Guangdong province in the years of 1984-1993].

This paper analysed the data of epidemic encephalitis B incidence that was constituted to time- series and the two-ordered contingency table in Guangdong province from 1984 to 1993. Two different kinds of statistical methods of run- test and ordered-log-ratio test were applied to study the characteristics of seasonal distribution. Consistent conclusion was obtained to show that there appeared an obvious seasonal cyclic characteristic of a peak every year (June or July) for the incidence of epidemic encephalitis B. It is helpful for the epidemiologists to understand the principle and method of these statistical tests.

China↗

[Xenogeneic antigens and immune response in pig to man xenograft].

Limitation of donor source for allograft makes the research on xenograft progress. Pig is regarded as one of the ideal donor animals. The major obstacle in xenograft is hyperacute rejection, which is caused by complements after they are activated by xenogeneic antigens combined with natural antibodies. It has been confirmed that alpha-Gal is the major target antigen, whose expression is incharged by alpha-1,3 galactosyltransferase (alpha-GT). The approaches to overcome hyperacute rejection against alpha-Gal included: immunoadsorption of xenogeneic natural antibodies, lysis of antigen by enzyme and genetic manupilation to obtain animal lack of alpha-GT. Besides alpha-Gal, there were other antigens binding to human serum antibody, such as gp65 and gp100, which was expressed on PAEC after induced by TNF, the A-like antigen. But their function was still unknown. It was debatable on the role of MHC in xenograft. Both direct and indirect pathway were involved in cellular response in xenograft.

Animals↗

[Reactivity of human peripheral blood lymphocyte to alpha-Gal on porcine arotic endothelial cell].

After escaping from the hyperacute rejection (HAR), the xenograft has to be faced the challenge of acute vascular, acute cellular and even chronic rejection. Endothelial cells have been confirmed as a kind of antigen processing cell (APC) in allo-rejection. The porcine aortic endothelial cell (PAEC) expressed SLA-II and B7 which are the characteristics of professional APC. PAEC also has plenty of alpha-Gal residues, whether the antigen play any role in the post-HAR is still unknown. Human and porcine peripheral blood lymphocyte (PBLC) were isolated and divided into two parts, one for the effectors and the another were incubated with mitomycin C (MMC) as stimulators. The two kinds of PBLC were mixed-cultured within five days. Cultured PAEC from NJZ Pig was incubated with MMC and divided into two: One digested with alpha-galactosidase. The two kinds of PAEC were taken as stimulators to mixed-culture with human PBLC for five days. All the proliferation was detected with 3H-TdR intermingled in the system. The results showed that allo-MLR was stronger than xeno-MLR in the cases. The proliferation was much stronger when PAEC was used as the stimulator than that of porcine PBLC. However, the response was remarkably decreased after the digestion of alpha-Gal with alpha-galactosidase. The conclusion was that the low response of porcine-to-human MLR in vitro might be related to the predominant indirect pathway of antigen recognition in this system. While PAEC was used as the stimulator the proliferation in MLR was stronger which might be concerned that PAEC itself was an APC as well as xeno-antigen sources, thus the direct pathway was predominant and worked more efficiently. The alpha-Gal might induce T cell proliferation through the linkage with the biological big molecules working as a complete antigen. The other post-HAR antigen might also exist in PAEC such as SLA-II, etc.

Animals↗

[Reactivity of tissues of chinese NJZ pig to human serum].

Insufficient supply of organ for allotransplantation made the study on finding new organ resources from animal progress. Pig is regarded as one of the optimal donor animals for human. The major obstacle in this field is hyperacute reaction (HAR), which is triggered after the xenogenic natural antibodies preexisting in recipient blood combine to the antigens on the surface of the endothelium and activate the complement system. alpha-Galactose residues (alpha-Gal) on the endothelial cell have been identified as the major xenoantigens. NJZ Pig has been closely breed since 1938, whose family history is clear. Tissue samples from heart, liver, kidney, pancreas, lung, small intestine, skin, spleen, thymus and lymph node were obtained and embedded in paraffin. The sections were performed the immunohistochemical staining with the sera from health volunteers (including all the blood types) as the primary antibodies as well as the biotin labeled bandeirae simplicifolia I isolectin B4 (BS I-B4), which has specific affinity to alpha-galactose. All the staining sections were compared with the tissues digested with alpha-galactosidase. There was no difference between the antigens recognized by sera of different blood types. alpha-Gal was still the major xenoantigen on the endothelial cells. There might exist non-alpha-Gal antigens on the distal convoluted tubules and collecting tubules of the kidney. There was no alpha-Gal distributing on the secreting part of pancreas, either the islet cells or the matrix cells, but surely on pancreatic duct and vessels. All the antigenity was destroyed after the enzyme digestion except that the small intestine gland still positive with the BS I-B4. alpha-Gal is the major xenogenic antigen in NJZ Pigs. There exist some unknown antigens on the distal convoluted tubules and collecting ducts of the kidney. The blood type of recipient is not the first affair to be considered in pig-to-human xenotransplantation. The specificity of BS I-B4 for the alpha-galactose needs more detail research.

Animals↗

[The effect of sex steroids on human ovarian granulosa cell apoptosis].

OBJECTIVES: To study the molecular mechanism of human follicular atresia by exploring the effects of estrogen, androgen on human granulosa cell (GC) apoptosis. METHODS: Ovarian GC DNA fragments of both atretic and developing follicles before and after estrogen (1 microgram/ml), androgen (1 microgram/ml) treatments were analysed by agarose gel electrophoresis. The expression of bcl-2 mRNA was also determined by northern blotting in GC of developing follicle after sex steroids addition. RESULTS: Internucleosomal DNA cleavage occurred in granulosa cells in atretic follicles and after androgen treatment. In granulosa cells of developing follicles, estrogen treatment increased the expression of bcl-2 mRNA by 45%, while androgen treatment downregulated the expression of bcl-2 mRNA by 35%. CONCLUSION: Androgens increase apoptotic DNA fragmentation, and decrease the expression of bcl-2 mRNA in GC of developing follicles, while estrogens produce the opposite effect. Therefore, expression of bcl-2 may be involved in the mechanism of follicular development and atresia.

Adult↗

[Management of hepatic trauma in 267 cases].

Two hundred and sixty-seven consecutive hepatic trauma in recent 17 years were analysed. They were classified by AAST classification: grade I and II 68 cases (25.4%), grade III 132 cases (49.44%), grade IV 52 cases (19.48%) and grade V 15 cases (5.6%) and 237 cases were operated in different procedures according to the severity of the trauma. More than ten modalities such as dedridement, suturing, repairment, abdominal drainage, billiary drainage, hepatic artery ligation, packing and pressing hemostasis, resection of traumatic parecchyma, vessel ligation with suturing in section etc were used, The morbidity and mortality were 20.6% and 8.9%, respectively. The other 24 cases were found no active bleeding during laporatomy and rehabitated with preservative management. The authors believe that effective management on time and intensive perioperative care are important to minimize the morbidity and mortality of hepatic trauma. Nonoperative management deserves enough attention.

Adolescent↗

[The effects of nitric oxide synthase on secondary spinal cord injury: an experimental research].

OBJECTIVES: To investigate the effects of the changing amount of nitric oxide on secondary spinal cord injury and determine the role of nitric oxide during secondary spinal cord injury. METHODS: After close spinal cord modest injury (T9) by fluid-percussion model, rats were given saline, small dose of L-NAME (8 mg/kg) and large dose of L-NAME (40 mg/kg) respectively. The changes of hemodynamics, tissue constitution, and neural function were observed. RESULTS: We found small dose of L-NAME had little effects on the hemodynamics but could improve neural function. Whereas, large dose of L-NAME raised the MABP significantly, constricted pial arteriole (90 minutes, 10%), decreased regional spinal cord blood flow (SCBF) (90 minutes, 22%), augmented the dysfunction of neural system. Rats lost weight and the rate of death raised. CONCLUSIONS: These findings indicated that nitric oxide could have dual role during secondary spinal cord injury. Controlling local nitric oxide production suitably through changing the activity of nitric oxide synthase could improve tissue survival and benefit the recovery of neural function.

Animals↗

[Angiographic embolization for the treatment of uncontrollable epistaxis].

In the treatment of 8 cases of patients with uncontrollable epistaxis, we used the embolization following vascular angiographic localization. They were cured and no any serious complication. Embolization is the safe and effective method of stopping uncontrollable epistaxis and is the best method in the elder patients with other diseases, under the condition of anterior and posterior nasal packing being controversial. It is the key that before embolization we make angiography to arteries and find the bleeding vessels. The technique of embolization, superselective embolization and so on are all important measures in the decreasing severe complications.

Aged↗

[Influence of fry-processing on outward character and inner quality of volatile oil containing drugs such as fructus Viticis, etc].

According to the requirement of outward character in processing traditional Chinese drugs, five volatile oil containing drugs Fructus Viticis, Rhizoma Atractylodis Macrocephalae, Rhizoma Cyperi, Fructus Foeniculi and Fructus Aurantii were fry-processed. The conditions of frying technology were measured; the amounts of volatile oil before and after processing were determined with accurate volatile oil extractor; and the volatile oil in Rhizoma Atractylodis Macrocephalae and Fructus Aurantii was analyzed by means of GC.

Apiaceae↗

[Studies on Epstein-Barr virus in patients with primary sinonasal non-Hodgkin's lymphoma].

OBJECTIVE: To study the relationship between Epstein-Barr virus (EBV) infection and primary sinonasal non-Hodgkin's lymphoma. METHODS: Using polymerase chain reaction (PCR) method, 22 patients with primary sinonasal non-Hodgkin's lymphoma (NHL), including 13 tumours of T cell type and 9 of B cell type, and mucosa from twenty cases of nasonasosinusitis were tested for the presence of Epstein-Barr virus (EBV) DNA. RESULTS: The results showed that 14 of 22 non-Hodgkin's lymphoma (63.6%) and 4 of 20 nasonasosinusitis mucosa (20%) were EBV-DNAase gene positive (9 T cell type and 5 B cell type). The difference between non-Hodgkin's lymphoma and nasal mucosa was statistically significant (P < 0.005). CONCLUSION: These results suggest that EBV is not only present in B lymphocyte lymphomas but also in T lymphocyte lymphomas.

Adolescent↗

[Pathological observation of the olfactory epithelium in dysosmia induced by chronic nasosinusitis].

OBJECTIVE: To understand the relationship between the pathology of the olfactory epithelium in dysosmia induced by nasosinusitis and the prognosis. METHODS: The olfactory epithelium of 23 patients who had chronic nasosinusitis and undergone endoscopic sinus surgery was histologically observed. All patients were diagnosed to have anosmia by olfactory tests before the operation. The history ranged from 5 to 30 years. Fifty were males and 8 females. RESULTS: Pathological changes were found in all cases: 16 (69.6%) with decreased olfactory cells, 10 (43.5%) had normal atrophic olfactory epithelia, 6 (26.1%) respiratory epithelial metaplasia and 10 (43.5%) mucous gland metaplasia. All the patients had been followed up for 6-10 months after operation. sixteen patients who had normal olfactory epithelia got improvement in their olfactory function; 7 patients whose olfactory epithelia were severely diseased got no amelioration of their symptoms. CONCLUSIONS: The quantity of olfactory cells bears a positive relation with the olfactory condition.

Adult↗

[The preliminary analysis of domestic hydrogel microspheres for endovascular embolization].

OBJECTIVE: To evaluate the embolic effects and biocompatibility of domestic hydrogel microspheres (HMs). METHOD: 22 domestic rabbits were used. 0.03 g/2ml, 0.06 g/2ml domestic Hms of 70 - 150 microm and 2 ml normal saline were injected respectively through catheterization in the right common carotid arteries of rabbits. The changes in neurologic functions, general state and average weight of rabbits were observed, and the histomorphological changes of embolized arteries and surrounding tissues were evaluated by analysis of macroscopy and light microscope. RESULT: Rabbits' neurologic symptoms (hemiparalysis, convulsion and hypotonia) and death were observed after embolization. Thrombogenesis was present and the entire cross sections of blood vessels could easily be embolized. Neither acute and chronic inflammatory cells nor remarkable general toxic and side effects were shown in rabbits. CONCLUSION: Domestic HMs can effectively block the vessels, and they have the characteristics of good biocompatibility. The kind of domestic HMs is a promising particulate embolic agent in clinical sets.

Animals↗

[Studies on the chemical constituents of the leaves from Artabotrys hexapetalus].

Artabotrys hexapetalus (annonaceae) is distributed in southern China. As a Chinese folk herb medicine, its root and fruits are used to treat malaria and scrofula, respectively. Two new flavonol glycosides, artabotryside-A (1), -B (2), three known flavonoids: taxifolin (3), 7-O-glucoluteolin (4), apigenin-7-O-apiosyl(1-->2) glycoside (5), and two organic acid: succinic (6) and fumaric acid (7) have been isolated from the leaves of A. hexapetalus. The structures of 1 and 2 were elucidated as quercetin-3-O-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinofuranoside (1) and kaempferol-3-O-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinofuranoside (2), respectively, on the basis of spectral analysis. The compounds 3 through 7 were found from A. hexapetalus for the first time.

Annonaceae↗

[Progress in the controlled release systems of hirudin].

Hirudin is very effective in treating and preventing cardiovascular disorders. In this review several polymeric controlled release systems of hirudin are introduced. The advantages of the local delivery for restenosis and the feasibility of endovascular drug-containing pharmaceutic stents for local therapy of cardiovascular thrombosis are discussed.

Coronary Thrombosis↗

[A novel high quality specific antithrombotic drug--hirudin].

Hirudin is the most potent specific inhibitor of thrombin, which is currently undergoing clinical trials as a novel antithrombotic drug. In this paper, the composition and structure, the pharmacological and pharmacokinetic characteristics, the anticoagulant and antithrombotic activity and function, the methods of isolation, recombination and syntheses were reviewed.

Fibrinolytic Agents↗

Modulation of adriamycin-induced changes in serum free fatty acids, albumin and cardiac oxidative stress.

Adriamycin-induced cardiomyopathic changes are prevented by combination therapy with probucol. These beneficial effects are suggested to be due to a combination of antioxidant as well as lipid-lowering effects of probucol. In the present study, we compared the effects of probucol (PROB) with that of lovastatin (LOV), a lipid-lowering drug, and trolox (TRO), an antioxidant, on adriamycin (ADR)-induced subchronic in vivo changes in serum free fatty acids (FFA), serum albumin and myocardial reduced (GSH) and oxidized (GSSG) glutathione in rats. ADR caused a significant increase in FFA, decrease in albumin, and an increase in FFA/albumin. PROB and LOV modulated the increases in FFA and FFA/albumin, while TRO was without any effect. ADR reduced myocardial GSH, increased GSSG and decreased GSH/GSSG. Only PROB caused significant improvement in GSH and normalized GSSG levels. It is suggested that these modulatory effects of probucol may also contribute in the beneficial effects of this drug against adriamycin-induced cardiomyopathy and congestive heart failure.

Animals↗