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Biomedical subjects

Z Song

Publications and source records attributed to Z Song.

At least 109 records · Page 6Linked to original sources
PubMed1998

[Three-dimensional volumetric display--a new application of frequency up-conversion].

This paper discusses the present research situation and the application prospect of 3-D volumetric display technology. The possible usability and science significance of frequency up-conversion in 3-D volumetric display field are also demonstrated systematically. In ZBLAN: Pr, Yb glasses, we primarily demonstrated and achieved a new application of frequency up-conversion three dimensional volumetric display, using the two-frequency up-conversion of the rare earth ions. The efficiency of luminescence of Pr was enhanced much by the energy transfer between Pr and Yb ions.

English Abstract↗
PubMed1998

[Study on the NIR-Raman spectra and NIR-SERS spectra of amsacrine].

The near infrared surface-enhanced Raman spectra (NIR-SERS) of amsacrine,an anticancer agent, on silver collids were recored with high quality. The NIR-SERS enhancement factor is up to 10(4) magnitude. In comparison with the near infrared Raman (NIR-Raman) spectra of solid amsacrine, more information of vibrational structures of amsacrine molecules at low concentration and almost in its practical application envi ronment, can be given by the NIR-SERS. The enhancement mechanism is associated with the adsorption of acridyl ring and sulfonyl on silver surface.

Amsacrine↗
PubMed1998

[Spectroscopic characterization of a new terbium complex with red fluorescence].

Usually, the emission spectra of terbium complexes exhibit 490 nm, 545 nm bands (green color) under the excitation of UV light, which is ascribed to the two 5D4 - 7F6, 5D4 - 7F5 transition. In this report, pink red fluorescence under the excitation of 300-370nm UV light is observed for a new 1, 10-phenanthroline-2-naphthoate complex of terbium. The fluorescence, FT-IR, ICP and X-ray fluorescence analysis were performed. The results showed that under the perturbation of the ligands field, the probability of 5D4 - 7F3 transition of terbium ion was greatly enhanced, while the probability of 5D4 - 7F5 transition was greatly decreased in the complex. Therefore, pink-red fluorescence was observed for the title complex.

English Abstract↗
PubMed1998

[Spectrofluorimetric study of trifluoroacetylacetone (TFA)-gadolinium(III)-CTMAB system and application].

The determination of microamount gadolinium(III) by fluorescence method was studied based on complex formation Gd(III)-CTMAB-TFA at pH7.2. Beer's law is obeyed in the range of 0. 005-0.04 microg/mL Gd(III). The detection limit is 0.003 microg/mL. The method is used to determine microamount gadolinium of rare-earth mine with satisfactory result, and compared with that of ICP-AES method.

English Abstract↗
PubMed1998

[Spectral study of podophyllotoxin and its derivatives].

In this paper, we have studied all kinds of static absorption spectra and transient absorption spectra of podophyllotoxin and its derivatives. We have located the site of absorption spectra and their forming mechanism with spectrofluorometry, Ultraviolet, pulse radiolysis and laser photolysis, and suggested the connection of their structrue with their anti-tumour and toxicity.

Antineoplastic Agents↗
PubMed1998

[Indirect sensitized upconversion in Tm3+ and Yb3+ codoped non-crystal pentaphosphate].

We report the blue upconversion luminescence of Tm3+ and Yb3+ codoped non-crystal pentaphosphate pumped by -798nm laser diode. The samples were directly excited to 3F4 level of Tm3+ ion. Two energy transfer processes between Tm3+ and Yb3+ contribute mainly to the population of 1G4 level of Tm3+. Phonon plays an important role in the upconversion process.

English Abstract↗
PubMed1998

[Study on the interaction between Cu2+ and cholesterol by spectrometric analysis].

With four kinds of spectrometric analysis methods, i.e. spectrophotometric analysis, AAS, ICP-AES and IR, the interaction between Cu2+ and cholesterol in aqueous solution has been examined. The same results from the different methods showed that there was a surface adsorption between Cu2+ and cholesterol and this interaction would be prominent in physiology-like situation.

Adsorption↗
PubMed1998

Expression of growth control and differentiation genes in human lens epithelial cells with extended life span.

PURPOSE: Peptide growth factors including hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF), and epidermal growth factor (EGF) are mitogens for many cell types and may act as regulators of lens epithelial cell growth and differentiation. The present study was undertaken to investigate the expression of growth factor receptors and crystallin genes in the human lens epithelial cell line HLE B-3, created by infection with Adeno12-simian virus 40 (Ad12-SV40) hybrid virus. METHODS: Reverse transcriptase-polymerase chain reaction (RT-PCR) with gene-specific primers was used to detect transcripts, and Southern and western blot analyses were used for identification of gene products. Functional analysis of PDGF receptor was performed by measuring the effect of PDGF-BB on Ca2+ release, cell growth, and western blot analysis, by using an antiphosphotyrosine antibody. RESULTS: Human lens epithelial B-3 cells expressed the growth factor receptors HGF-R, EGF-R, and PDGF-Rbeta, but not PDGF-Ralpha, and also expressed the oncogenes H-ras and raf and the growth inhibitor transforming growth factor-beta1. Stimulation of PDGF-Rbeta with PDGF-BB in HLE B-3 cells increased phosphorylation of the receptor, was associated with an increase in intracellular Ca2+ levels, and produced a small increase in cell growth. In addition, HLE B-3 cells expressed transcripts for alphaA-, alphaB-, and betaB2-crystallins, and expressed the corresponding proteins. The transcripts for alphaA-crystallin decreased markedly at higher passages. CONCLUSIONS: The above findings suggest that the increased growth potential of human lens epithelial cells by Ad12-SV40 infection maintained certain lens-specific properties and response to PDGF.

Adult↗
PubMed1997

DCP-1, a Drosophila cell death protease essential for development.

Apoptosis, a form of cellular suicide, involves the activation of CED-3-related cysteine proteases (caspases). The regulation of caspases by apoptotic signals and the precise mechanism by which they kill the cell remain unknown. In Drosophila, different death-inducing stimuli induce the expression of the apoptotic activator reaper. Cell killing by reaper and two genetically linked apoptotic activators, hid and grim, requires caspase activity. A Drosophila caspase, named Drosophila caspase-1 (DCP-1), was identified and found to be structurally and biochemically similar to Caenorhabditis elegans CED-3. Loss of zygotic DCP-1 function in Drosophila caused larval lethality and melanotic tumors, showing that this gene is essential for normal development.

Amino Acid Sequence↗
PubMed1997

Cellular immune responses to orthopaedic implant materials following cemented total joint replacement.

In vitro cellular immune responses to metallic and polymeric implant materials in particulate form were measured preoperatively in 185 patients. The patients were candidates for either primary total joint replacement (n = 65) or revision arthroplasty (n = 120). Proliferative cellular responses to polymethylmethacrylate particles in patients with osteoarthritis at revision surgery for aseptic loosening were significantly higher than the responses of patients with osteoarthritis at either primary surgery or surgical revision for mechanical failure of the prosthesis or sepsis. The responses to particles of cobalt-chromium alloy at revision surgery were also higher than the responses at primary surgery. The responses were reevaluated in 32 patients after a minimum of 10 months following surgery to correlate individual changes in the biological responses with clinical progress. Reevaluation at early follow-up of patients who had undergone primary surgery revealed significantly elevated proliferative responses and in vitro cytokine production in response to polymethylmethacrylate and cobalt-chromium alloy particles compared with their preoperative responses. In contrast, the response at follow-up to polymethylmethacrylate was significantly reduced in patients who had undergone revision surgery, and this reduction corresponded with a marked improvement in pain, joint motion, and function following revision surgery. These data suggest that specific cellular responses to polymethylmethacrylate or cobalt-chromium alloy particles, or both, may be associated with loose or painful prostheses.

Arthroplasty, Replacement↗
PubMed1997

Conformational transitions of the phosphodiester backbone in native DNA: two-dimensional magic-angle-spinning 31P-NMR of DNA fibers.

Solid-state 31P-NMR is used to investigate the orientation of the phosphodiester backbone in NaDNA-, LiDNA-, MgDNA-, and NaDNA-netropsin fibers. The results for A- and B-DNA agree with previous interpretations. We verify that the binding of netropsin to NaDNA stabilizes the B form, and find that in NaDNA, most of the phosphate groups adopt a conformation typical of the A form, although there are minor components with phosphate orientations close to the B form. For LiDNA and MgDNA samples, on the other hand, we find phosphate conformations that are in variance with previous models. These samples display x-ray diffraction patterns that correspond to C-DNA. However, we find two distinct phosphate orientations in these samples, one resembling that in B-DNA, and one displaying a twist of the PO4 groups about the O3-P-O4 bisectors. The latter conformation is not in accordance with previous models of C-DNA structure.

Crystallography, X-Ray↗
PubMed1997

Primary structure and functional expression of heavy- and light-chain variable region genes of a monoclonal antibody specific for human fibrin.

The immunoglobulin heavy- and light-chain variable region (VH and VK) genes were isolated from 8E5 hybridoma cells, which secreted monoclonal antibody against human fibrin by RT-PCR. An expression vector pOPE51-8E5 was constructed for the recombinant VH-VK scFv expression. The primary sequence of the variable regions was determined. Expression product was found in the periplasmic space and inclusion bodies by SDS-PAGE and immunoblotting. It was a 30 KDa single chain fragment (scFv) with the antigen-binding specificity of the parental monoclonal antibody. A light chain shuffling with an unspecific VL did not result in a loss of fibrin binding specificity.

Amino Acid Sequence↗
PubMed1997

Ginseng treatment reduces bacterial load and lung pathology in chronic Pseudomonas aeruginosa pneumonia in rats.

The predominant pathogen in patients with cystic fibrosis (CF) is Pseudomonas aeruginosa, which results in a chronic lung infection associated with progressive pulmonary insufficiency. In a rat model of chronic P. aeruginosa pneumonia mimicking that in patients with CF, we studied whether the inflammation and antibody responses could be changed by treatment with the Chinese herbal medicine ginseng. An aqueous extract of ginseng was injected subcutaneously, and cortisone and saline were used as controls. Two weeks after challenge with P. aeruginosa, the ginseng-treated group showed a significantly improved bacterial clearance from the lungs (P < 0.04), less severe lung pathology (P = 0.05), lower lung abscess incidence (P < 0.01), and fewer mast cell numbers in the lung foci (P < 0.005). Furthermore, lower total immunoglobulin G (IgG) levels (P < 0.01) and higher IgG2a levels (P < 0.025) in serum against P. aeruginosa sonicate and a shift from an acute type to a chronic type of lung inflammation compared to those in the control and cortisone-treated groups were observed. These findings indicate that ginseng treatment of an experimental P. aeruginosa pneumonia in rats promotes a cellular response resembling a TH1-like response. On the basis of these results it is suggested that ginseng may have the potential to be a promising natural medicine, in conjunction with other forms of treatment, for CF patients with chronic P. aeruginosa lung infection.

Animals↗
PubMed1997

T cell receptor (V beta) bias in the response of rheumatoid arthritis synovial fluid T cells to connective tissue antigens.

T cell receptor (V beta) use in the response to type II collagen and cartilage proteoglycans was analysed in peripheral blood and synovial fluid T cells from RA patients. T cells from RA patients with an immune response to connective tissue antigens, and paired PB and SF samples were stimulated in vitro with type II collagen, high density aggrecan proteoglycans (PG), and the T cell mitogen concanavalin A. After short term culture, mRNA was extracted from cells and a reverse transcription-polymerase chain reaction was performed, using primers specific for eight TCR V beta determinants. Blood cells stimulated with ConA generated strong bands with virtually all the V beta primers tested, but the TCR (V beta) expression by SF T cells stimulated with mitogen was biased, suggesting a selection process during joint infiltration. The V beta phenotypes of cells responding to PG was restricted in individual RA patients, but the pattern of V beta use in the the RA population was not consistent. In contrast, the V beta phenotypes of SF cells responding to CII was highly biased in both individual patients and the RA population, with V beta 14, V beta 17, and V beta 8 phenotypes predominant. We conclude that the T cell response to connective tissue antigens is restricted compared with mitogen stimulation, with the highest degree of TCR bias seen in the response of SF T cells to stimulation with type II collagen.

Aged↗
PubMed1997

[The significance of midline structure shifting in the patients of cerebral hemorrhage in basal ganglia by computerized tomography].

Thirty-six patients of cerebral hemorrhage in basal ganglia were studied between medline structure shifting on CT scan and assessment of clinic neurological function, defect (AND). The differences were significant between the following two groups: including in parameter A (the distance from center of hematoma to normal midline), 26.01 +/- 6.06 mm in survivor group, 21.53 +/- 5.03 mm in death group; in parameter B (the distance from the farthest point in shifted midline to the normal midline), 3.84 +/- 2.66 mm in survivor group, 10.32 +/- 4.24 mm in death group; in parameter C (ratio of the partial length of shifted midline to all length of the normal midline), 0.347 +/- 0.136 in survivor group; 0.582 +/- 0.082 in death group. Having analized these parameters, the authors found that the mortality rates were 0 and 100% if B was < or = 4.0 mm and > 10.0 mm respectively and the mortality rates were 0 and 90% if C was < or = 0.30 and > 0.50. The authors also found that there was closed correlation between the parameters B or C described midline shifting and AND.

Adult↗
PubMed1997

Clinical comparison of pulsatile and nonpulsatile perfusion during cardiopulmonary bypass.

Controversy exists concerning the utilization of pulsatile flow during cardiopulmonary bypass (CPB) with regard to improved patient outcomes. The purpose of the present study was to evaluate pulsatile perfusion in patients undergoing CPB in a clinical setting. Seventy patients undergoing open heart surgery for repair of valvular or congenital heart disease were prospectively entered into the study and were randomly assigned to either pulsatile perfusion (PP, n = 35) or nonpulsatile perfusion (NP, n = 35) groups. All patients received identical surgical, perfusion, and postoperative care. Study parameters included: rate of spontaneous cardiac conversion, inotropic drug use, urine output, skin temperature, platelet count, fibrinogen concentration, and plasma free hemoglobin level. There were no statistically significant differences seen in either preoperative or operative parameters between groups. The PP group had a significantly higher rate of spontaneous cardiac conversion, less inotropic drug use, earlier recovery of skin temperature, and higher urine output during CPB (908.8 +/- 87.2 ml/hr vs. 606.1 +/- 57.5 ml/hr, p < .01). There were no significant differences in either platelet count or fibrinogen concentration between groups. There was a steady increase in plasma free hemoglobin during PP, which was not seen in the NP group (p < .01). We conclude that the use of pulsatile flow resulted in improved patient outcomes in maintaining better renal function and preserving cardiac function in the early post-bypass period.

Adult↗
PubMed1997

[Cloning and expression of heavy- and light-chain variable region genes of monoclonal antibody specific for human fibrin].

OBJECTIVE: To obtain the minimum molecule having activity to bind human fibrin. METHODS: The immunoglobulin heavy- and light-chain variable region (VH and Vkappa) genes were isolated from 8E5 hybridoma cells, which secreted a monoclonal antibody against human fibrin, by RT-PCR. An expression vector pOPE51-8E5 was constructed for the recombinant VH-Vkappa expression. The transformed E. coli JM 109 cells were propagated and induced by IPTG. RESULTS AND CONCLUSION: Expression product was found in the periplasmic space and inclusion bodies by SDS-PAGE and immunobloting. It was a 30000 single chain fragment (scFv) with antigen-binding specificity. The yield of the scFv was 28.9% of the total bacterial proteins.

Animals↗