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Biomedical subjects

X Chen

Publications and source records attributed to X Chen.

At least 1,135 records · Page 63Linked to original sources
PubMed1997

[Optimization of quenching system for determination of emodin and chrysophanol by chemiluminescence method].

Determination of the valid components in traditional Chinese medicine is one of the key steps for its identification, and the development of accurate and simple methods is necessary for the present analysis work of medicines. In this paper, the experimental conditions were optimized and procedures chosen for determination of emodin and chrysophanol by lunminol-H2O2-Cr3+ chemiluminescence quenching system. The dynamic range for determination of emodin was 10(-4)-10(-8) g/ml (r = 0.9965), with a detection limit of 1.57 x 10(-9) g/ml. The RSD and recovery for determination of 10(-7) g/ml of emodin (n = 6) were 0.4% and 92.8% +/- 0.5%, respectively. Satisfactory results were also obtained when the method was used to determine chrysophanol. This method was used, after separation by thin layer chromatography, to determine emodin and chrysophanol in several traditional Chinese patent medicines, and the results were in good agreement with those obtained by the standard colorimetric method.

Anthraquinones↗
PubMed1997

[Apoptosis-antagonizing protein Bcl-2 expression, distribution in non-Hodgkin's lymphoma and its clinical significance].

OBJECTIVE: Apoptosis-antagonizing protein Bcl-2 expression, distribution in non-Hodgkin's lymphoma (NHL) and its clinical significance were studied. METHODS: Four-stage peroxidase antiperoxidase complex (PAP) method was applied to comparatively investigate the expression and distribution of Bcl-2 protein in formalin-fixed, paraffin-embedded lymph node tissue comprising 12 cases of reactive follicular hyperplasia and 71 cases of NHL. RESULTS: (1) Bcl-2 protein was detected in 93.0% cases of NHL with T- or B-lymphocytic phenotype. (2) Bcl-2 protein was restricted in centrocytes but not in centroblasts in 8 of 9 cases of NHL stemed from germinal centers. (3) A significant increase in Bcl-2 protein expression was found in 5 of 10 cases of diffuse large B-lymphocytic NHL showing plasmacytoid differentiation. (4) In 7 cases of follicular NHL the neoplastic nodules were strongly labeled for Bcl-2 protein and only scattered positive cells were seen in its periphery; On the contrary, in reactive lymphoid follicles Bcl-2 protein was predominantly anchored in mantle zones whereas germinal center cells were unstained. CONCLUSION: (1) Bcl-2 protein is expressed in NHL of T- or B-cell origin. (2) Bcl-2 protein expression appears to be associated with differentiation stages of NHL. (3) Immunohistochemical staining for Bcl-2 protein conduces to differentiate between reactive and neoplastic follicles.

Apoptosis↗
PubMed1997

[Mechanism of protective action of Phyllanthus urinaria L. against injuries of liver cells].

It has been found out that the carbon tetrachloride (CCl4)-induced increase of serum glutamic-pyruvic transaminase (ALT) and elevation of MDA in liver of mice are significantly lowered by Phyllanthus urinaria in vivo, and the coincubation of isolated rat hepatocytes with Phyllanthus urinaria in vitro significantly inhibits CCl4-induced decrease of mobility of membrane of liver cells and increase of intracellular free Ca2+ ([Ca2+]i) concentrations of liver cells. These results suggest that the anti-lipid peroxidation effect and protective action of membrane of Phyllanthus urinaria may be related to its protective action against CCl4-induced liver injuries.

Alanine Transaminase↗
PubMed1997

[A comparative study on the chemical components of Salvia miltiorrhiza Bge. collected from Zhongjiang of Sichuan and from other habitats].

In this paper, the chemical components in the root of Salvia miltiorrhiza from three habitats (Zhongjiang of Sichuan, Henan and Shandong) were comparatively studied. The results show that the TLC chromatogram and contents of tanshinone IIA in the crude drugs are about the same, the sodium content appears to be lower in the sample from Sichuan, but the contents of other metallic elements are about the same in the samples from different habitats.

Abietanes↗
PubMed1997

[Growth development of Ligustium chuanxiong Hort].

Experimental studies and chemical analysis have been made on Ligustium chuanxiong in its period of growth, generation and growth of organs, content and accumulation of nutritive elements, accumulation of dry matters, fertilizer consumption, etc.

Apiaceae↗
PubMed1997

[Significance of nm23 expression in malignant carcinoma of salivary gland].

In recent years, a tumor suppressor gene nm23 has been found to be associated with decreased tumor metastatic potential. Allelic deletion, mutation and low expression of this gene has been correlated with tumor metastatic potential in a number of tumors. We examined the expression of nm23 in 40 cases of salivary gland malignant carcinomas by immunohistochemical method. The results showed that nm23 lower expression tumors were associated with a higher rate of metastasis (81.8%) than nm23 higher expression (3.4%, P < 0.005). There is no correlation between nm23 lower expression and tumor size, location and pathologic type (P > 0.05). This result indicates that nm23 gene plays an important role in the metastasis of salivary gland malignant carcinoma.

Adult↗
PubMed1997

[Purification and some properties of extracellular beta-glucosidase from Rhizopus japonicus IFO5318].

The beta-glucosidase from Rhizopus japonicus IFO5318 was purified by Ammonium sulfate salting out and column chromatographies with the recovery of 22%. The molecular weight of the enzyme was about 4.0 x 10(5), consisting of four identical subunits; The optimum reaction temperature and pH for the beta-glucosidase were 55 degrees C and pH 5.5, respectively; While the enzyme was sensitive to heat, it could be stable at a wide range of pH. The Km and Vmax values of the enzyme were 0.825 mg.ml-1 and 135.4 mumol.min-1.mg-1, respectively, using p-Nitrophenyl-beta-D-glucopyranoside as a substrate. The beta-glucosidase exhibited strongest hydrolysis effect on cellobiose and some of its activity could be inhibited by SDS, Fe3+ and Hg2+.

Molecular Weight↗
PubMed1997

[The side effect and complication of intraarterial phosphorus-32 glass microspheres for patients with advanced hepatoma].

The phosphorus-32 glass microspheres(32P-GMS) is a new radioembolizer for cancer therapy. From March 1994 to April 1995, 24 patients with unresectable hepatocellular carcinoma and 3 patients with cavernous hemangioma received internal radiation treatment of 32P-GMS. The clinical results demonstrated that hepatic arterial instillation of 32P-GMS appeared to be safe and effective for hepatocellular carcinoma. There was no significant bone marrow or renal toxicity or liver to pulmonary bypass. A transient change of liver function and fever occurred in almost all patients. Significant liver toxicity and gastrointestinal tract reaction were seen when radiation dose > 50 Gy or microspheres > 3 g, and then various postoperative complications occurred.

Adult↗
PubMed1997

[Influence of smear layer and adhesive resin on the adaptation of amalgam restoration to cavity walls].

This in vitro study evaluated the effect of removing smear layer and applying adhesive on the marginal adaptation of amalgam fillings to cavity walls. Three groups were established, cavities in group 1 were exposed to 10% EDTA (pH7.4) for 1 minute to remove smear layer before amalgam condensation; cavities in group 2 were also subjected to EDTA, then Miradapt adhesive was applied on the walls, finally amalgam condensed into cavities before the adhesive set; cavities in group 3 received no special treatment before amalgam condensation. After thermocycling, all teeth were subjected to SEM and image analyser. Results showed: Space between restorations and tooth structure in group 1 was 6.31 microns, space in group 2 with adhesive was 3.49 microns and micromechanical interlocking was observed while space in control group was 14.22 microns. Difference among the three groups was statistical significant. It was indicated that removing smear layer and using adhesive resin significantly improved the adaptation of amalgam to cavity walls.

Composite Resins↗
PubMed1997

[Establishment of immediate implant animal model in mongrel dog's fresh extraction socket].

The purpose of the study was to establish the animal models which had clinical characteristics in bone defect sizes around immediate implants. The mesial region of dogs' fresh extraction sockets were made with 3 mm x 3 mm x 5 mm size bone defects around implants with a round bur, then observed their osseous changes at 2 weeks, 4 weeks, 8 weeks, 12 weeks with and without demineralized freeze-dried bone allograft (DFDBA) filled. The results showed that the bone defects in DFDBA grafted group were substituted by new bone, but the defects in ungrafted group were only substituted to 3/5. Such animal models had the advantages of simple preparations and similar clinical characteristics, so they were beneficial to investigation of the immediate implantation.

Animals↗
PubMed1997

[Benign focal melanotic lesions of the oral mucosa: a clinicopathologic study of 41 cases].

41 patients with benign focal melanotic lesions on the oral mucosa were studied. The results showed that among the patients, 27 were female and 14 male, the mean age was 33 years old, and the most common site was the lip and gingiva. Clinically, the lesions were focal and well-defined, the size was about 0.6 cm in diameter. Histologically, 21 cases were pigmented nuvus on the oral mucosa (18 cases with nevocellular nevus and 3 cases with the common blue nevus), 2 cases were junctional change, 5 cases were the lentigo simplex, and 13 cases were oral melanotic macule. The characteristics of the oral melanotic macule and the junctional change were discussed.

Adolescent↗
PubMed1997

[A comparative study on the blood vessel sclerosing effect of pingyungmycin and Natrii morrhuates].

Twelve adult rabbits were used in this experiment. After posterion auricular veins were temporarily blocked, pingyungmycin and natrii morrhuatis were injected separately and their effect on the blood vessels was studied. The results showed that pingyungmycin caused endotheliac cell oedema, degeneration, vascular shrinkage, vascular wall thickening, while the effect of natrii morrhuatis on the blood vessels was thrombosis, organization of thrombus and closure of the lumen of the blood vessels. The sclerosing mechanisms of the two medicines and their clinical applications were discussed.

Animals↗
PubMed1997

[Effects of extract of Cortex Ilicis Rotundae on cardiovascular pharmacology].

In thes paper, the effects of Cortex Ilicis Rotundae (CIR) on Cardiovascular Pharmacology are studied. The results show that ethyl alcohol extract of CIR can reduce coronary blood flow, weaken myocardial contractility, slow down heart rates, prolong survival time of mice and prevent arrhythmias, the roles of CIR decoction are similar to ethyl alcohol extract, but it is not markable on heart rates and myocardial contractility.

Animals↗