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Biomedical subjects

C Zhang

Publications and source records attributed to C Zhang.

At least 577 records · Page 32Linked to original sources
PubMed1996

[A study on changes of levels of products of lipid peroxidation in retina of rat with experimental autoimmune uveoretinitis].

OBJECTIVE: To understand the mechanisms of the retinal tissue destruction of rat with experimental autommune uveoretinitis (EAU) induced by rabbit retinal soluble antigen. METHOD: The levels of the following products of lipid peroxidation were determined at different times, conjugated dienes, malondialdehyde, fluorochrome lipid and lipid hydrogen peroxide. RESULTS: In the process of EAU, the levels of products of lipid peroxidation in the retina were increased gradually in various degrees. CONCLUSION: It is suggested that the damage from lipid peroxidation mediated by free radicals of the retina be one of the factors which induces the retinal destruction in EAU.

Animals↗
PubMed1996

[CuZn-SOD determination of sera in patients with rheumatic diseases].

Superoxide anion (O2.-) plays an important part in reactive oxygen species (ROS). In order to explore its effect on the pathogenesis of rheumatic diseases, authors had determined CuZn-SOD contents of sera in 132 subjects involving the patients of rheumatic diseases (SLE, RA, etc), non-rheumatic diseases and normal controls by using enzyme linked immunosorbent assay (ELISA). The results showed the followings: CuZn-SOD contents of 27 normal subjects: 98.80 +/- 20.74 ng/ml (x +/- s); that of 27 non-rheumatic diseases cases: 72.24 +/- 16.60 ng/ml (x +/- s); of 22 SLE cases: 56.56 +/- 19.27 ng/ml (x +/- s); of 27 RA cases: 61.56 +/- 20.53 ng/ml (x +/- s); of 29 other rheumatic diseases cases: 68.97 +/- 17.79 ng/ml (x +/- s). Statistical test was made: both CuZn-SOD contents of rheumatic disease and non-rheumatic disease were lower than that of normal subjects with more significant difference (P < 0.001); compared with that of non-rheumatic diseases patients, SLE cases had significant difference (P < 0.01); RA cases had significant difference (P < 0.05); other cases of rheumatic diseases had no statistical differrence (P > 0.05). Above results suggest that superoxide anion is a non-specific inflammatory mediator which contributes to disorders with inflammatory damages (rheumatic or non-rheumatic diseases), where CuZn-SOD content tested was obviously lower than normal subjects; among the rheumatic disease patients, CuZn-SOD contents of the sera of SLE patients were the lowest because of its more autoimmune antibody, more severe inflammatory and immunological reaction. This work laid the theoretical and experimental foundation for the clinical application of exogenous CuZn-SOD in the treatment of rheumatic diseases. Combined use of CuZn-SOD scavengers may get better result because of the complexibility of ROS inflammatory mechanism.

Adolescent↗
PubMed1996

[Establishment of an effective way for separating and culturing tumor infiltrating lymphocytes].

The key to preparing TILs for clinical application is to enhance its capacity of proliferation and cytotoxicity. For this purpose we have made a study of methodology and established an effective way consisting of 3 processes to separate and culture TILs. It included: (1) mechanical splitting; (2) digesting with 0.05% collagenase I and 0.003% DNAase I mixture in room temperature for 6 hrs and 18hrs in cool, and (3) centrifuging with 75% and 100% Ficoll non-continuous grade density. The separated TILs were suspended in conditional culture medium for proliferation. Most of them reached the amount of 10(9) at the end of culture, which was essential for clinical therapy. Their NK and LAK activities were 56.3 +/- 11.7% and 48.6% +/- 10.6% respectively, in which the CD6+ T cells played an important role. The results suggest this a perfect way for separating and culturing TILs.

Cell Culture Techniques↗
PubMed1996

[Effect of methimazole and dexamethasone on leucocyte glucocorticoid receptor, plasma ACTH, and cortisol levels in Graves' disease].

Thirty-two cases of newly diagnosed Graves' disease with hyperthyroidism were recruited in this study on the changes of leucocyte glucocorticoid receptor (GCR), plasma ACTH, and cortisol levels befor and after treatment with methimazole (tapazole) alone (n = 16) and methimazole combined with Dexamethasone (Dex, TD group, n = 16). Twenty normals served as the control. Methimazole treatment was initiated with a dosage of 40 mg/d, tapered to 20 mg/d after two weeks and maintained until complete remission in both groups. Meanwhile, Dex 6 mg/d was added to the TD group along with methimazole from the commencement of therapy. The dosage of Dex was reduced to 4.5 mg/d on the 5th day and to 2.25 mg/d two weeks after treatment, and continued until remission. It was found that there was remarkable decrease in leucocyte GCR levels with a moderate elevation of plasma ACTH and a slight decline of plasma cortisol in untreated Graves' disease, suggestive of a compensation of the pituitary-adrenal axis function in hyperthyroidism. The levels of GCR, ACTH and cortisol returned to normal after complete remission by methimazole in the methimazole alone group. In the TD group, however, all GCR, ACTH and cortisol levels were significantly decreased after Dex therapy, implying down regulation of GCR by exogenous Dex and suppresion of the pituitary-adrenal axis. Thus the dosage of glucocorticoid should be appropriately adjusted to avoid adrenal insufficiency, especially in case of stress, due to the suppresion of pituitary adrenal function.

Adrenocorticotropic Hormone↗
PubMed1996

[Reconstitution of Hu-SCID mice transplanted with human tonsillar lymphocytes immunized with dengue virus-2 in vitro and its immune response].

OBJECTIVE: To study the measure for the reconstitution of severe combined immunodeficient disease mice (SCID mice) transplanted with human lymphocytes immunized with specific antigen in vitro. METHODS: Hu-SCID mice were constructed by intraperitoneal (i.p.) transfer of human tonsillar lymphocytes (TLC) first immunized with dengue virus-2 (DV2) in vitro, then boostered with different doses of DV2 antigen in vivo. RESULTS: Human immunoglobulin (Ig) and specific human anti-DV2 antibodies could be detected in sera of the hu-SCID mice by ELISA. Two weeks after transplantion of the in vitro-immunized hu-TLC, the highest human IgG concentration was 412.86 micrograms/ml, two or four weeks later specific human anti-DV2 IgM or IgG and the neutralizing antibody could found in these sera, respectively, the highest titer was 1:6400. The levels of human IgG and human anti-DV2 antibodies were related to the dose of DV2 antigen. The presence of human B cells (CD20+) and T/cells (CD3+, CD4+, CD8+) were shown in the sleen, lung, intestine and mesentery of the hu-SCID mice as determined by immunoperoxidase staining, and the cells were distributed correspondingly with the lymphocyte cells in proper human tissue. Human anti-DV2 IgG could also be detected in the spleen cell culture obtained from the SCID mice. CONCLUSION: By co-immunized in vitro and in vivo the SCID mice deduced stronger immune response for specific antigen, and the reconstitution of the human lymphocytes could be established successfully.

Animals↗
PubMed1996

[Epidemiological survey of Graves' disease on a hundred thousand people in Daging area].

OBJECTIVE: To study the incidence of Graves' disease and associated factors. METHODS: A total of 100123 people aged 15-79 in Daqing region were surveyed epidemiologically. The investigations were conducted for an average two years. RESULTS: 301 patients with Graves' disease were newly diagnosed, 74 of them (1.6/1000) were males and 227 (4.1/1000) females. The total incidence was 3.0/1000. The incidence had significant differences between ages and occupations. Investigations of 18 associated factors for Graves' disease by using the Logistic multivariate regression analysis showed the following pathological factors, virus history, psychological stimulation, food, drugs, family history, education, distributions, etc. CONCLUSION: This study may provide the theoretical evidence for prevention and treatment of Grave's disease.

Adolescent↗
PubMed1996

[Labeling of antihuman bladder carcinoma monoclonal antibody with a technetium-99m and radioimmunoimaging of human bladder carcinoma xenograft in nude mice].

Anti-human bladder carcinoma cell line BIU-87 monoclonal antibody-BDI-1 was labeled with 99mTc by direct mercaptoethanol reducing method. Quality control tests showed that the labeling yield was 69.9%; the radiochemical purity was higher than 90%; the immunoreactive fraction of 99mTc-BDI-1 was 81% and the association constant was 1.22 x 10(-9) M-1. The radioimmunoimaging of human bladder carcinoma xenograft in nude mice and the biodistribution of 99mTc-BDI-1 were studied. After having been scintigraphed at three time intervals (at 4, 16 and 22 hour), the animals were sacrificed for biodistribution of 99mTc-BDI-1. Tumor can be seen clearly at 22 hour after intravenous injection of 99mTc-BDI-1; %ID/g (percentage of the injected dose per gram of tissue) of tumor was 20.70, the average T/NT was 10.52, the minimum T/NT was 2.90 (tumor/kidney) and the maximum T/NT was 20.70 (tumor/small intestine or muscule). The results above indicated that 99mTc-BDI-1 can be used for radioimmunodetection of human bladder carcinoma in vivo and BDI-1 may be suitable as a targeting device in patients.

Animals↗
PubMed1996

[The effect of electroacupuncture on the discharge activity of temperature-sensitive neurons of preoptic-anterior hypothalamus in the rabbit treated by arginine vasopressin].

Arginine vasopressin (AVP) has been shown to have significant effects on the thermoregulation. The present experiments were to investigate the effect of electroacupuncture (EA) on the discharge activity of temperature-sensitive neurons of preoptic-anterior hypothalamus (PO-AH) in rabbits treated by AVP and arginine vasopressin monoclonal antibody (AVPMcAb). The results were as follows: (1) AVP could markedly promote the firing activity of EA on heat-sensitive neurons in PO-AH. (2) AVPMcAb could markedly reduce the effect of EA on temperature-sensitive neurons in PO-AH. Experimental results indicated that the mechanisms of EA on hypothermia might be related to AVP.

Animals↗
PubMed1996

[Experimental study on uptake of fluoride by dentin after pulsed Nd:YAG laser irradiation].

The purpose of this study was to determine the uptake of fluoride by dentin after pulsed Nd:YAG laser irradiation. Under SEM examination dentin lased by pulsed Nd:YAG laser appeared to be melted; there were no changes of calcium and phosphorus levels. Dentin irradiated by pulsed Nd:YAG laser and treated with 38% Ag(NH3)2F showed greater uptake and deep penetration of fluoride than topical application of fluoride alone, SEM examination revealed that CaF2-like and Ag3PO4-like deposits were formed on the dentin surface. These results suggested that pulsed Nd:YAG laser irradition could improve the absorption of fluoride in dentin.

Dentin↗
PubMed1996

[Clinical application and observation of silicone oil in complicated retinal detachment].

Nine eyes with complicated retinal detachment underwent vitrectomy and silicone oil tamponate among whom there were seven eyes with PVRC3-PVRD2, one eye with giant retina tear and PVRD3 and one eye with giant retina tear. All the eyes were followed-up for an average of 12.6 months with a range from 2 to 23 months. Retina were completely reattached in there eyes. Vision were improved in six eyes. Retina was redetached in one eye after removal of silicone oil. Silicone oil tamponate can be used in complicated retinal detachment that fails to respond to conventional method. However, silicone oil tamponate may cause a number of complications, so its indications should be properly taken care of.

Adolescent↗
PubMed1996

[Interleukin-6 and immune state in children with nephrotic syndrome].

IL-6 activities were determined in 37 children with idiopathic nephrotic syndrome (INS) by using an IL-6 dependent murine hybridoma-clone (MH60). The results showed that the levels of IL-6 activities in children with INS at the stage of onset were significantly higher than those of normal control group (P < 0.01), and the levels of IL-6 activities had positive correlation with the levels of urinary protein in 24 hours. The levels of IL-6 activities decreased remarkably at the stage of remission. CD+3 cells and the levels of serum IgG decreased significantly in those with INS; CD+8 cell increased and CD+4/CD-8 cell ratio decreased obviously in those with the simple nephrotic syndrome (SNS) at the stage of onset as compared with normal control group. These results indicate that there are immune disorders characterized by increased level of IL-6 activity in INS and suggest that IL-6 plays an important role in the development of INS.

CD4-CD8 Ratio↗
PubMed1996

[Improved MTT colorimetric assay for NKC activity].

The established improved 3-(4,5-dimethyl thiazoly)2,5-diphenyl-tetrazolium bromide (MTT) colorimetric assay for measuring the amount and function of living cell by the authors has the characteristics of simplicity, dependability and good repeatability within 3-12 hours. We have used this improved MTT colorimetric assay in measuring natural kill cell (NKC) activity of human peripheral blood. The results show that when the activities of effector cell (EC) and target cell (TC) are > or = 95%, and the density of EC is > or = 3 x 10(2)/well and that of TC > or = 1.6 x 10(2)/well, the number of living cell is positively correlated with the OD570nm volume of purple formazan metabolite of MTT solution (re = 0.94, ri = 0.97, P < 0.001). When the ratio of EC/TC is 40:1, the NKC activity of peripheral blood of health adults is equal to that report by Zhang Chongjie et al. By this MTT colorimetric assay, the NKC activity of peripheral blood of 10 leukemic patients has been detected. The mean +/- s of NKC activity is 34.86 +/- 7.80%, which is postively correlated with the result (35.16 +/- 8.40%) of the inhibition of 3H-TdR incorporation assay performed at the same time (r = 0.876, P < 0.001). MTT colormetric assay for NKC activity avoids getting in touch with isotope. It is a convenient and valuable method.

Adult↗
PubMed1996

[The relationship between the retinal lipid peroxidation or antioxidation and age in rats].

OBJECTIVE: To investigate the relationship between the retinal lipid peroxidation (LPO) or antioxidation and age. METHODS: The thiobarbituric acid (TBA) and chemical luminescence methods, were used to detect the retinal malondialdehyde (MDA) content produced by LPO and superoxide dismutase (SOD) activity which represents the antioxidation ability of retina in 22 rats different ages. RESULTS: The retinal MDA contents were 0.18 +/- 0.06, 0.16 +/- 0.06, 0.38 +/- 0.11, 0.49 +/- 0.09 nmol/mg protein respectively in 5, 12, 18, 24 months old (F test, P < 0.01); the retinal SOD activities were 0.99 +/- 0.30, 2.48 +/- 0.56, 0.70 +/- 0.35, 0.85 +/- 0.57 U/mg protein respectively in 5, 12, 18, 24 months old rats (F test, P < 0.01). CONCLUSIONS: The retinal MDA content increased and SOD activity decreased with aging. The cumulative effects of the long-term photochemical damage and decreased antioxidation ability in retina might be the causes of the increased retinal LPO.

Aging↗
PubMed1996

[Effect of processing on the content of guanfu A in radix Aconiti coreani].

Quantitative determination of guanfu A in Radix Aconiti Coreani before and after processing has been made by dual-wavelength TLC-scanning. The results show that the content of guanfu A is about 0.144% before processing, and 0.106%-0.12% after steam processing (n = 4), which is greatly higher than other processed products. The average recovery rate is 97.64% (n = 5).

Alkaloids↗
PubMed1996

[Chemical components of Cynomorium sonaricum Rupr].

Two stigmastenol compounds were isolated from the root of Cynomorium songaricum and identified by chemical and spectral methods as 5 alpha-stigmast-9(11)-en-3 beta-ol and 5 alpha-stigmast-9(11)-en-3 beta-ol-tetracosantrienoic acid ester.

Drugs, Chinese Herbal↗
PubMed1996

[Effect of hemin in treating hemorrhagic anemia and toxicity].

AIM: To study the effect of hemin in treating hemorrhagic anemia and toxicity. METHODS: Fifty rats with hemorrhagic anemia were randomly divided into 5 groups with different dosage of hemin (93, 168, 300 mg.kg-1.d-1), ferrous gluconate (FG 300 mg.kg-1.d-1), and water, ig for 7 d. Twenty mice fed with hemin (6.0 g.kg-1.d-1) in 24 h for observing acute toxicity effects. Long-term toxicity were observed in 80 rats given hemin (0.65, 1.3, 2.6 g.kg-1.d-1) in 3 months. RESULTS: Hb of the rats of corresponding groups were 66-->121, 71-->141, 66-->148, 69-->140, and 67-->112 g.L-1. There were no adverse effects observed on acute toxicity test. No abnormalitis were found in hemogram, liver renal function test, and autopsy. CONCLUSION: Hemin had a better effect than FG and no adverse effect was found in hemin.

Anemia, Iron-Deficiency↗
PubMed1995

The role of membrane proximal threonine residues conserved among guanine-nucleotide-binding-protein-coupled receptors in internalization of the m4 muscarinic acetylcholine receptor.

Many guanine-nucleotide-binding-protein-coupled receptors contain consensus sequences for phosphorylation by cAMP-dependent protein kinase (PKA), often located in the membrane proximal regions critically important for receptor signalling. In the present study, we have evaluated by site-directed mutagenesis the role of the putative PKA phosphorylation sites in the m4 muscarinic acetylcholine receptor (mAChR), i.e. Thr145 in the second cytoplasmic loop and Thr399 in the third cytoplasmic loop, and the influence of PKA on m4 mAChR function and internalization. Antagonist binding was unaltered by any of the mutations studied, while the agonist-binding affinity was either not affected (Thr145 alanine), increased (Thr399 alanine) or decreased (Thr399 serine or aspartic acid). m4 mAChR-mediated inhibition of adenylyl cyclase was unaltered by the mutations, except for an approximately tenfold reduced agonist potency of the Thr399 aspartic acid mutated receptor. Agonist-induced receptor internalization was unaltered with Thr399 serine or aspartic acid mutations of the receptors, but was strongly decreased in its rate and extent upon replacement of Thr399, Thr145 or both of these residues with alanine. These mutational effects could not be reproduced by treatment of wild-type receptor-expressing cells with the PKA inhibitor H-8. Furthermore, maximal stimulation of cellular PKA neither affected receptor internalization nor signalling measured as receptor-mediated Ca2+ mobilization. We conclude that the membrane proximal threonine residues of the m4 mAChR are not required for receptor signalling, but replacement by alanine residues can significantly affect receptor internalization, independently of PKA phosphorylation. Sequence comparisons suggest that threonine residues at corresponding positions may be relevant to internalization of other guanine-nucleotide-binding-protein-coupled receptors.

Amino Acid Sequence↗