Biomedical subjects

Y Deng

Publications and source records attributed to Y Deng.

At least 55 records · Page 3Linked to original sources

PubMed2001

Nitric oxide increases fluid extravasation from the splenic circulation of the rat.

We hypothesized that nitric oxide (NO) contributes to intrasplenic fluid extravasation by inducing greater relaxation in splenic resistance arteries than veins such that intrasplenic microvascular pressure (P(C)) rises. Fluid efflux was estimated by measuring the difference between splenic blood inflow and outflow. Intrasplenic infusion of the NO donor S-nitroso-N-acetylpenicillamine (SNAP) (0.3 microg. 10 microl(-1). min(-1)) caused a significant increase in intrasplenic fluid efflux (baseline: 0.8 +/- 0.4 ml/min, n = 10 vs. peak rise during SNAP infusion: 1.3 +/- 0.4 ml/min, n = 10; P < 0.05). Intrasplenic P(C) was measured in the isolated, blood-perfused rat spleen. Intrasplenic infusion of SNAP (0.1 microg. 10 microl(-1). min(-1)) caused a significant increase in P(C) (saline: 10.9 +/- 0.2 mmHg, n = 3 vs. SNAP: 12.2 +/- 0.2 mmHg, n = 3; P < 0.05). Vasoreactivity of preconstricted splenic resistance vessels to sodium nitroprusside (SNP) (1 x 10(-12)-1 x 10(-4) M) and SNAP (1 x 10(-10)-3 x 10(-4) M) was investigated with the use of a wire myograph system. Significantly greater relaxation of arterioles than of venules occurred with both SNP (%maximal vasorelaxation: artery 96 +/- 2.3, n = 9 vs. vein 26 +/- 1.9, n = 10) and SNAP (%maximal vasorelaxation: artery 50 +/- 3.5, n = 11 vs. vein 32 +/- 1.7, n = 8). These results are consistent with our proposal that differential vasoreactivity of splenic resistance arteries and veins to NO elevates intrasplenic P(C) and increases fluid extravasation into the systemic lymphatic system.

Animals↗

PubMed2001

Splenorenal reflex regulation of arterial pressure.

During the course of our studies into the control of fluid extravasation from the splenic vasculature, we found that intrasplenic inhibition of NO biosynthesis caused an increase in systemic blood pressure. The present experiments were designed to investigate the mechanisms underlying this novel observation. There was an increase in mean arterial pressure when the nonspecific NO inhibitor N(G)-monomethyl-L-arginine (L-NMMA) was infused via the splenic artery but not when the same dose was administered systemically. Conversely, blood pressure decreased after intrasplenic but not systemic administration of the NO donor S-nitroso-N-acetyl-D,L-penicillamine. There was no pressor response to intrasplenic administration of either the inducible or neuronal NO synthase inhibitors N-[3-(aminomethyl)-benzyl] aceramidine and L-N(5)-(1-imino-3-butenyl)-ornithine. The pressor response to L-NMMA was abolished by denervation of either the spleen or the kidney and by pretreatment with the ACE inhibitor enalapril. We propose that the spleen influences systemic blood pressure through a reflex pathway comprising splenic afferent nerves and renal sympathetic control of renin release.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2001

[A rapid and simple detection of DNA fragment with point mutation by capillary electrophoresis].

OBJECTIVE: To establish a rapid and simple method with high efficiency in detecting point mutation of genomic DNA. METHODS: Four DNA fragments that were different from each other in only one based were amplified by using primers with artificial point mutation based on the sequence of exon 7 of p53 gene, and then were separated by capillary electrophoresis(CE). The neutral coated capillary and 4% linear polyacrylamide gel buffer were used, and the wave length of ultraviolet detector was 254 nm. RESULTS: A homozygous 196 bp DNA fragment can be separated into one dsDNA peak and two ssDNA peaks within 25 minutes, and the heterozygous 196 bp DNA fragments that were made with mixed wild type and mutated DNA can be separated into one dsDNA peak and three ssDNA peaks. The three ssDNA fragments that differ in one nucleotide can be easily separated with good resolution. CONCLUSION: CE technique is rapid, sensitive, accurate and well reproducible. It is an efficient and reliable method for rapidly screening point mutation.

Base Sequence↗

PubMed2001

[Serum markers and pathological evaluation in hepatitis fibrosis of chronic hepatitis B treated with interferon alpha].

OBJECTIVE: To evaluate the anti-fibrotic effect of interferon alpha and to study the relationship between the anti-fibrotic effect and the efficacy of anti-virus in patients with chronic hepatitis B treated with interferon alpha. METHODS: Thirty-six patients with chronic hepatitis B were treated with interferon alpha. Before, during and after the treatment, the levels of hyaluronic acid (HA), type III procollagen (PC-III), type IV collagen(IV-C), laminin (LN) and transforming growth factor beta 1 (TGF-beta 1) were measured as the markers of hepatic fibrosis. Needle biopsy sections of the liver taken before and at the end of IFN treatment were assessed and compared according to the modified histological activity index (HAI) and hepatic fibrosis (HF) scoring system. RESULTS: In IFN group, the levels of HA, PC-III, IV-C, LN, and TGF-beta 1 after treatment were all significantly lower than those before treatment (P<0.01). The levels of HA, PC-III, and TGF-beta 1 after treatment were significantly lower in IFN group than in control one. HAI scores decreased from 9.3+/-3.2 to 6.2 +/-2.1 and HF scores decreased from 7.5+/-2.2 to 5.1+/-1.8 after treatment. CONCLUSIONS: The improvement of hepatic fibrosis closely related to the efficacy of anti-virus. Interferon alpha therapy is effective for hepatic fibrosis of chronic hepatitis B.

Adolescent↗

PubMed2001

Urinary excretion of aquaporin-2 water channel protein in chronic heart failure rats.

OBJECTIVE: To study the urinary excretion of aquaporin-2 (AQP2) water channel protein, and the relationship between urine AQP2 concentration and renal AQP2 gene expression in chronic heart failure (CHF) rats. METHODS: Male Sprague-Dawley rats (200 g-250 g) underwent either a left coronary artery ligation, a model of CHF, or a sham-operation. Nine weeks after surgery, urinary AQP2 concentrations and renal AQP2 protein levels were measured by Western blot. RESULTS: The urinary concentration of AQP2 water channel protein increased significantly in CHF rats as compared with sham-operated rats (365.6% +/- 102.9% vs 98.5% +/- 47.6%, P < 0.01). There was positive correlation between urinary AQP2 concentration and renal AQP2 protein expression (r = 0.89, P < 0.01). CONCLUSION: The urinary concentration of AQP2 water channel protein increases significantly in chronic heart failure rats.

Animals↗

PubMed2001

Expression of hHR21sp gene by peripheral blood and hematopoietic cells of normal subjects and Fanconi anemia patients.

OBJECTIVE: The radiation sensitive gene rad 21 of Schizosaccharomyces pombe is involved in the repair of double-stranded breaks in DNA and is essential for mitotic growth. The hHR21sp gene is its human homologue. In an attempt to investigate the role of hHR21sp in DNA repair, we studied the effects of UV and gamma-ray irradiation on hHR21sp gene expression in normal human peripheral blood cells, and non-iradiated peripheral and bone marrow cells from Fanconi anemia (FA) patients who have shown DNA repair deficiency. METHODS: Total steady state RNA was extracted from peripheral blood cells and bone marrow. RNA transcripts were quantified after RT-PCR and Southern blot, phosphoimmage and autoradiogram analysis. The results were compared with control groups. RESULTS: hHR21sp expression was significantly increased from 3 h to 9 h after UV irradiation in peripheral blood cells from normal subjects at doses of 40-80 j/m2 (P < 0.05). hHR21sp was also up-regulated by gamma-ray irradiation at 6 h to 9 h at dose of 1 to 5 Gy (P < 0.01), which was more significant than the UV irradiation. In the non-irradiated FA patient group, hHR21sp expression was decreased in bone marrow hematopoietic cells (P < 0.05). After activation by PHA and IL-2, there was still a significant depression in expression by the FA patients peripheral blood cells compared with control groups (P < 0.05). CONCLUSION: hHR21sp was up-regulated at doses and times irradiated at the range tested in normal peripheral blood cells, and is more affected by gamma-ray irradiation than UV irradiation. FA patient bone marrow hematopoietic cells and peripheral blood mononuclear cells showed down-regulation of hHR21sp expression. The results imply that defects in DNA repair via hHR21sp expression may play an important role in the pathogenesis of FA syndrome.

Adolescent↗

PubMed2001

[Study on the quality standards for xianghe suppository].

The quality standards for Xianghe suppository were studied. The TLC methods for identification of Rhizoma Coptidis, Radix Sophorae Flavescentis and Flos Caryophylli were established. A simple high performance liquid chromatographic method was established for determination of berberine and palmatine. The mobile phase was acetonitrile-water(1:1, containing KH2PO4 3.4 g, CH3(CH2)11 SO4Na 1.7 g per 1000 ml). UV detecting wavelength was 345 nm. This method is suitable for the quality control of Xianghe suppository.

Berberine↗

PubMed2001

[Clinical observation of TNF-alpha content in nasopharyngeal secretion of patients with nasopharyngeal carcinoma].

OBJECTIVE: To detect the changes of tumor necrosis factor-alpha (TNF-alpha) in nasopharyngeal secretion of patients with nasopharyngeal carcinoma(NPC). METHOD: The content of TNF-alpha in nasopharyngeal secretion was determined by radioimmunoassay (RIA) in 20 controls, 52 patients with NPC. RESULT: The average concentrations of TNF-alpha were (12.95 +/- 4.62) pmol/L in control group, (33.68 +/- 15.13) pmol/L in NPC group and (64.00 +/- 11.57) pmol/L in NPC with necrosis group. The content of TNF-alpha in nasopharyngeal secretion in control group was lower significantly than that of patients with NPC (P < 0.01). CONCLUSION: The level of TNF-alpha in nasopharyngeal secretion of NPC patients was higher than that of normal subjects. To detect the content of TNF-alpha in nasopharyngeal secretion is a useful test for the study and diagnosis of NPC.

Adult↗

PubMed2001

The analysis of electroretinography of diabetes mellitus.

PURPOSE: In order to get deeper understanding of Diabetic Retinopathy(DR), we analyzed and evauated the results of the amplitude and latency of F-ERG a-wave, b-wave and the total amplitudes of oscillatory potentials(OPs). METHODS: F-ERG of 105 eyes from 55 cases of DM were diagnosed by the medical department from July 1997 to July 1998. The 105 eyes were examined by ophthalmoscope and fluorescing in angiography and divided into there groups: 22 eyes with DM without DR(NDR), 56 eyes with background DR(BDR) and 27 eyes with proliferate DR(PDR). In addition, 30 eyes were regard as normal control group(NCG). We used VATA-2000 type vision electrophysiological instrument and inter-national standard for clinical ERG to do measure meat and recording automatically by computer. RESULTS: 1. The proportion of eyes number of invisible wave of a-wave, b-wave of F-ERG and Ops increased with the development of DR. 2. There were significant differences(P < 0.01) in the latency of a-wave between NCG and BDR and statistical significance(P < 0.05) between BDR and NDR. There were significant differences(P < 0.01) in the amplitude of b-wave among NCG and BDR, NCG and PDR, NDR and BDR, NDR and PDR. 3. The total amplitudes of OPs lowered with progressions of DR. There were significant differences(P < 0.01) in tota amplitudes of OPs between NCG and NDR, NCG and BDR, NDR and BDR, statistical significance(P < 0.05) between NDR and PDR. 4. There was no correlation between each index and the duration of the disease (P < 0.05). CONCLUSION: The amplitude of a-wave, b-wave, and total amplitudes are the targets for early diagnosis of DR. The combined analyses of the three indexes of ERG can determine the severity, curative effect, and prognosis of the disease.

Adult↗

PubMed2001

[Immunohistochemistry research on keratoconus].

PURPOSE: Keratoconus is a noninflammatory disease characterized by thining and ectasia of the central cornea. The etiology and pathogenesis of keratoconus remain unclear. We studied the composition of basement membranes (BM) in normal, scarred and keratconus corneas to find out possible changes specific for keratoconus. METHODS: Paraffin-embeded sections of normal, scarred and keratoconus corneas were immunostained with antibodys against type IV collagen, Fibronectin (Fn) and Laminin (Ln). RESULTS: Keratoconus had increased staining of the epithelial BM for alpha 1-alpha 2 chain of type IV collagen and Fn, especially in scarred corneal regions. A similar enhancement was also observed in scarred corneas, and there was no significant difference between keratoconus and scarred cornea. CONCLUSION: A process similar to wound healing would largely contribute to the differences seen in the keratoconus.

Adolescent↗

PubMed2001

[Assessing the quality of life of people with chronic diseases using SF-36].

OBJECTIVE: To analyze the influence of chronic diseases on the quality of life by using short form of 36 (SF-36). METHODS: Four hundred and thirty-eight people with chronic diseases were surveyed in a township and a city in Sichuan Province. The diseases were classified according to ICD-9 and the quality of life of people with chronic diseases of different systems was analyzed. RESULTS: The quality of life of people with chronic diseases of different systems was lower than that of general people aged 40 or above. The quality of life varied among people with chronic diseases of different systems in four fields, namely PF, SF, VT and MH. The main diseases that influenced the quality of life were mental disorders, infectious and parasitic diseases, the diseases of blood and blood-forming organs. CONCLUSION: The chronic diseases have decreased the quality of life. The diseases of different systems have had different influences on the quality of life. SF-36 is suitable for assessing the quality of life of people with chronic diseases. Quality of life should be taken as an important health index in chronic disease control and prevention.

China↗

PubMed2000

Preoperative mobilization of circulating dendritic cells by Flt3 ligand administration to patients with metastatic colon cancer.

PURPOSE: To evaluate preoperative dendritic cell (DC) mobilization and tumor infiltration after administration of Flt3 ligand (Flt3L) to patients with metastatic colon cancer. PATIENTS AND METHODS: Twelve patients with colon cancer metastatic to the liver or lung received Flt3L (20 microg/kg/d subcutaneously for 14 days for one to three cycles at monthly intervals) before attempted metastasectomy. The number and phenotype of DCs mobilized into peripheral-blood mononuclear cells (PBMCs) were evaluated by flow cytometry. After surgical resection, metastatic tumor tissue was evaluated for DC infiltration. In vivo immune responses to recall antigens were measured. RESULTS: After Flt3L administration, on average, the total number of leukocytes in the peripheral blood increased from 5.9 +/- 1.0 x 10(3)/mm(3) to 11.2 +/- 3.8 x 10(3)/mm(3) (mean +/- SD, P: =. 0001). The percentage of CD11c(+)CD14(-) DCs in PBMCs increased from 2.4% +/- 1.8% to 8.8% +/- 4.7% (P: =.004). Delayed-type hypersensitivity (DTH) responses to recall antigens (CANDIDA:, mumps, and tetanus) showed marginally significant increases in reactivity after Flt3L administration (P: =.06, P: =.03, and P: =.08, respectively). An increase in the number of DCs was observed at the periphery of the tumors of patients who received Flt3L compared with those of patients who had not. CONCLUSION: Flt3L is capable of mobilizing DCs into the peripheral blood of patients with metastatic colon cancer and may be associated with increases in DC infiltration in the peritumoral regions. Flt3L mobilization is associated with a trend toward increased DTH responses to recall antigens in vivo. The use of Flt3L to increase circulating DCs for cancer immunotherapy should be considered.

Adjuvants, Immunologic↗

PubMed2000

Peg3/Pw1 promotes p53-mediated apoptosis by inducing Bax translocation from cytosol to mitochondria.

Mitochondria is believed to play a central role in p53-mediated apoptosis. However, the signal transduction pathways leading to mitochondria remain unclear. Here, we report that translocation of Bax protein from cytosol to mitochondria is required for p53-induced apoptosis. Cytosolic Bax is unable to induce apoptosis, and blocking Bax translocation inhibits cell death. Expression of Bcl-2 blocks cytochrome c release and apoptosis but has no effect on Bax translocation, suggesting that Bax translocation acts upstream of Bcl-2. We further demonstrate that Peg3/Pw1, a protein up-regulated in p53-mediated cell death process, induces Bax translocation independent of apoptosis. The results suggest that Bax translocation represents an important regulatory step in p53-mediated apoptosis, and Peg3/Pw1 functions as a modulator downstream of p53 to regulate Bax redistribution in the cells, thus favoring the cellular decision toward apoptosis over growth arrest following p53 induction.

Apoptosis↗

PubMed2000

Tumor-specific recognition of human myeloma cells by idiotype-induced CD8(+) T cells.

Immunoglobulin secreted by myeloma cells contains a unique antigenic determinant (idiotype [Id]) that may serve as a tumor-specific antigen. Although Id-protein-specific T-cell responses have been reported in patients with myeloma, it is not known whether primary myeloma tumor cells can present naturally processed Id peptides on their surface as a target. We immunized 2 healthy human stem-cell donors with Id proteins from their recipients. T cells from the immunized donors released high levels of T-helper 1-type cytokines in response to stimulation with myeloma cells from their recipients. The T-cell-mediated cytokine response to tumor cells was blocked by a major histocompatibility complex (MHC) class I monoclonal antibody, whereas the response to soluble Id protein was dependent on MHC class II. To investigate whether Id-specific CD8(+) T cells can recognize and kill autologous myeloma cells, we generated T cells from peripheral blood mononuclear cells from a third patient with myeloma by means of in vitro stimulation with autologous dendritic cells pulsed with Id protein. Tumor-specific lysis of myeloma cells was demonstrated by the lack of killing of autologous nonmalignant B cells or natural killer-sensitive K562 cells. Lysis of autologous myeloma targets was restricted by MHC class I molecules. These data represent the first report of class I-restricted T-cell recognition of fresh autologous myeloma targets and formally demonstrate that human myeloma cells can serve as targets of an Id-specific T-cell response. (Blood. 2000;96:2828-2833)

Adult↗

PubMed2000

Total synthesis of oxidized phospholipids. 3. The (11E)-9-hydroxy-13-oxotridec-11-enoate ester of 2-lysophosphatidylcholine.

A total synthesis of (11E)-9-hydroxy-13-oxotridec-11-enoate ester of 2-lysophosphatidylcholine (HOT-PC) was devised to facilitate identification of this oxidized phospholipid. A lactone, 8-(3-oxo-1H,6H-2-oxinyl)octanoic acid (1), believed to be generated through an intermediate (11E)-9-hydroxy-13-oxotridec-11-enoic acid (HOT), is produced upon autoxidation of linoleic acid. A synthesis of lactone 1 methyl ester was accomplished from HOT involving a novel trans-cis isomerization that is driven to completion by cyclization to a hemiacetal. An alternative route to this carbon skeleton was also achieved that provides the lactone 1 itself.

Isomerism↗

PubMed2000

The 1.7 A crystal structure of human cell cycle checkpoint kinase Chk1: implications for Chk1 regulation.

The checkpoint kinase Chk1 is an important mediator of cell cycle arrest following DNA damage. The 1.7 A resolution crystal structures of the human Chk1 kinase domain and its binary complex with an ATP analog has revealed an identical open kinase conformation. The secondary structure and side chain interactions stabilize the activation loop of Chk1 and enable kinase activity without phosphorylation of the catalytic domain. Molecular modeling of the interaction of a Cdc25C peptide with Chk1 has uncovered several conserved residues that are important for substrate selectivity. In addition, we found that the less conserved C-terminal region negatively impacts Chk1 kinase activity.

Catalytic Domain↗

PubMed2000

Xanthene-bridged cofacial bisporphyrins.

The synthesis and characterization of cofacial bisporphyrins juxtaposed by xanthene-bridged pillars are presented. The one-pot preparation of the xanthene dialdehyde avoids the lengthy bridge synthesis accompanying other cofacial porphyrin systems, thus allowing for the facile preparation of homobimetallic zinc (10), copper (11), and nickel (12) complexes. The cofacial orientation of the two porphyrin macrocycles was confirmed by X-ray crystallography. Structural data are provided for bisporphyrins 10-12: 10 (C79H82N8OZn2), triclinic, space group P1, a = 11.2671(2) A, b = 14.9809(2) A, c = 20.4852(2) A, alpha = 101.6680(10) degrees, beta = 100.8890(10) degrees, gamma = 101.8060(10) degrees, Z = 2; 11 (C79H82N8OCu2), triclinic, space group P1, a = 11.21410(10) A, b = 14.9539(5) A, c = 20.6915(7) A, alpha = 101.810(2) degrees, beta = 101.044(2) degrees, gamma = 101.722(2) degrees, Z = 2; 12 (C79H82N8ONi2), monoclinic, space group C2/c, a = 24.1671(4) A, b = 10.669 A, c = 50.5080(9) A, beta = 99.553(2) degrees, Z = 8. Exciton interactions between the porphyrin rings are apparent in electronic spectra, consistent with the cofacial superstructure. The combination of structural and spectroscopic data provides a basis for the design of additional metal derivatives for the activation of dioxygen and other small molecules.

Bridged-Ring Compounds↗

PubMed2000

Characterisation of two new gene cassettes, aadA5 and dfrA17.

Escherichia coli INS33 was isolated from the urinary tract of an infected patient. It was resistant to ampicillin, chloramphenicol, spectinomycin, streptomycin, sulfafurazole, tetracycline and trimethoprim. PCR screening revealed the presence of a class 1 integron that harboured two new gene cassettes, designated dfrA17 and aadA5. The new dfrA17 cassette was 91% identical to the known dfrA7 cassette. The aadA5 cassette was 95% identical over the first 830 bp to aadA4, but lacked the IS26 element found at the 3' end of this truncated cassette. Cloning and expression of the cassette region demonstrated that dfrA17 conferred high level resistance to trimethoprim but aadA5 conferred resistance to spectinomycin but not to streptomycin.

Amino Acid Sequence↗