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Biomedical subjects

Jing Li

Publications and source records attributed to Jing Li.

At least 253 records · Page 14Linked to original sources
PubMed2005

Towards dilute magnetic semiconductors: Fe and Co substituted inorganic-organic hybrid materials based on ZnSe.

Inorganic-organic hybrid nanostructures doped with magnetic ions have been synthesized via substitution of Zn by Co or Fe in the ZnSe(L)0.5 systems under solvothermal conditions. These dilute magnetic semiconductors (DMS), Zn(1-x)MxSe(L)0.5 (M = Co, Fe; L = ethylenediamine or en, 1,3-propanediamine or pda; 0 < x < 1), are composed of perfectly ordered Zn(1-x)MxSe semiconductor monolayers interconnected by organic diamine molecules. The large blue shifts in their optical absorption edges (approximately 1.1-1.5 eV) compared to the bulk ZnSe are a direct result of a very strong quantum confinement effect (QCE). Magnetic studies show that there exist antiferromagnetic interactions between the Co or Fe centers in the structures and the interaction is enhanced as the doping concentration increases. The introduction of Fe or Co to hybrid inorganic-organic semiconductors provides a promising route to generate materials that combine the advantageous features of inorganic, organic, and magnetic functionalities in a single structure.

Cobalt↗
PubMed2005

High-sensitivity NO2 detection with carbon nanotube-gold nanoparticle composite films.

Composite films of single-walled carbon nanotube mesh doped with alkanethiol monolayer protected gold clusters (MPCs) have been investigated for ultrahigh sensitivity detection of nitrogen dioxide. The response to NO2 (measured as increased conductance) of the composite materials increased with MPC loading until a threshold MPC loading level was achieved, after which no further enhancement of sensor response is observed. The total of about ten droplets of MPC solution had been cast atop the SWNT mesh. The detection limit for NO2 has been improved 9.6-fold, to 4.6 ppb, compared with that obtained with pure SWNT sensors. Ultraviolet illumination helps to speed up the sensor recovery. All tests were done under ambient conditions.

Electrochemistry↗
PubMed2005

Potentiation of T cell function by a marine algae-derived sulfated polymannuroguluronate: in vitro analysis of novel mechanisms.

Marine algae-derived sulfated polymannuroguluronate (SPMG), a candidate drug for AIDS treatment, was intraperitoneally injected into normal mice for 6 weeks, and the in vivo and in vitro mechanisms of SPMG for immunomodulation were investigated in isolated lymphocytes by MTT assay, flow cytometry, and surface plasmon resonance assay. SPMG treatment at 5 and 10 mg/kg enhanced concanavalin A (ConA)-induced T cell proliferation, cellular levels of CD69, interleukin-2 (IL-2), and interferon-gamma (IFN-gamma), as well as CD4/CD8 ratio, while decreasing tumor necrosis factor-alpha (TNF-alpha) level in T cells of peripheral blood mononuclear cells. In addition, 1 molecule of SPMG bound to 2/3 molecules of IL-2 with a K(D) of 9.53 x 10(-7) M. Heparin prevented SPMG binding to IL-2 by 72.2%; thus, to a large extent, SPMG and heparin share common binding sites on IL-2. In contrast, other glycosaminoglycans (e.g., chondroitin sulfate and dermatan sulfate) had little effect on SPMG and IL-2 interaction, suggesting the requirement of a defined sequence within the sugar chain for specific recognition of IL-2. Concomitant treatment of IL-2 and SPMG augmented lymphocyte proliferation, compared with IL-2 alone; in contrast, SPMG alone had no proliferative effect. Taken together, our findings demonstrated for the first time that SPMG exerted its immunomodulation by direct activation of T cell function, accompanied by simultaneous modulation of cytokine function, which suggests that SPMG would show great promise for use in anti-AIDS therapy.

Adjuvants, Immunologic↗
PubMed2005

Protection of mitochondrial integrity from oxidative stress by selenium-containing glutathione transferase.

The antioxidant activity of a novel artificial glutathione peroxidase-like enzyme, selenium-containing glutathione 5-transferase from Lucilia cuprina (seleno-LuGST1-1), was studied by using a ferrous sulfate/ascorbate-induced mitochondrial damage model system. Swelling of mitochondria, lipid peroxidation, and cytochrome-c oxidase activity were selected to evaluate the preservation of mitochondrial integrity in this system. Seleno-LuGST1-1 could effectively protect the mitochondria against oxidative damage in a dose-dependent manner and exhibited both higher catalytic activity and greater antioxidant ability than the classic mimic, 2-phenyl-1,2-benziososelenazol-3(2H)-one (Ebselen). This novel artificial biocatalyst therefore may have great potential for pharmacologic application in the treatment of reactive oxygen species-related diseases.

Animals↗
PubMed2005

A novel technique of three-dimensional reconstruction segmentation and analysis for sliced images of biological tissues.

A novel technique of three-dimensional (3D) reconstruction, segmentation, display and analysis of series slices of images including microscopic wide field optical sectioning by deconvolution method, cryo-electron microscope slices by Fourier-Bessel synthesis and electron tomography (ET), and a series of computed tomography (CT) was developed to perform simultaneous measurement on the structure and function of biomedical samples. The paper presents the 3D reconstruction segmentation display and analysis results of pollen spore, chaperonin, virus, head, cervical bone, tibia and carpus. At the same time, it also puts forward some potential applications of the new technique in the biomedical realm.

Algorithms↗
PubMed2005

Altered hepatic and muscle substrate utilization provoked by GLUT4 ablation.

Studies were conducted to explore altered substrate utilization and metabolism in GLUT4 null mice. Liver fatty acid synthase mRNA and fatty acid synthesis rates were dramatically increased in GLUT4 null mice compared with control mice and were supported by increased rates of the pentose phosphate pathway oxidative phase and sterol regulatory binding protein mRNA expression. Increased GLUT2 protein content, glucokinase mRNA, and glucose-6-phosphate in GLUT4 null mice may provide substrate for the enhanced fatty acid synthesis. Increased fatty acid synthesis, however, did not lead to hepatic triglyceride accumulation in GLUT4 null mice because of increased hepatic triglyceride secretion rates. GLUT4 null mice rapidly cleared orally administered olive oil, had reduced serum triglyceride concentrations in the fed and the fasted state, and increased skeletal muscle lipoprotein lipase when compared with controls. Oleate oxidation rates were increased in GLUT4 null skeletal muscle in association with mitochondrial hyperplasia/hypertrophy. This study demonstrated that GLUT4 null mice had increased hepatic glucose uptake and conversion into triglyceride for subsequent use by muscle. The ability of GLUT4 null mice to alter hepatic carbohydrate and lipid metabolism to provide proper nutrients for peripheral tissues may explain (in part) their ability to resist diabetes when fed a normal diet.

Animals↗
PubMed2005

[Effect of Xingding Injection on expression of heat shock protein 72 in vascular endothelial cells].

OBJECTIVE: To study the effect of Xingding Injection on the expression of heat shock protein 72 (HSP 72) in vascular endothelial cells after ultraviolet radiation. METHODS: Porcine aortic endothelial cells were cultured for 72 hours in culture mediums with different concentrations (0.1, 0.5, 1.0, 5.0, 10 mg/ml) of Xingding Injection. Ultraviolet radiation was administered to the cultured cells for 30 minutes. Western-blot assay was used to measure the expression of HSP 72 in the vascular endothelial cells. RESULTS: There was no expression of HSP 72 in the cultured vascular endothelial cells without ultraviolet radiation, but there was some expression of HSP 72 after ultraviolet radiation. Xingding Injection of different concentrations could significantly improve the expression of HSP 72. The expression of HSP 72 in the vascular endothelial cells cultured in culture medium with 1.0 mg/ml Xingding Injection was the highest, and there was no more increase of expression when the concentration was higher, instead the expression decreased. CONCLUSION: Xingding Injection can protect the vascular endothelial cells from injury during stress. It may be one of its mechanisms in preventing and treating cardio-cerebrovascular disorders.

Animals↗
PubMed2005

[Immunological mechanism of exfoliative tongue fur in children with asthma].

OBJECTIVE: To explore the immunological mechanism of exfoliative tongue fur in children with asthma. METHODS: Thirty-nine children with asthma, twenty-eight children with repetitive respiratory tract infection (non-asthma) and eleven healthy children were divided into five groups, which were asthma with exfoliative fur or with non-exfoliative fur groups, non-asthma with exfoliative fur or with non-exfoliative fur groups and normal control group. The concentrations of keratin 13 and bcl-2 in cells exfoliated from tongue fur were detected by immunohistochemical method. The expression levels of blood cell chemokine receptor-3 (CCR-3) and CD4(+) were examined by flow cytometry, and the levels of serum cortisol and IgE were detected by radioimmunoassay. RESULTS: The levels of blood CD4(+) and CCR-3 of children with asthma and exfoliative fur were higher than those in the asthma with non-exfoliative fur group and the normal control group (P<0.05). The serum level of cortisol in the groups of asthma with exfoliative fur and non-asthma with exfoliative fur were lower than that in the other groups (P<0.05). The serum levels of IgE in asthma with exfoliative fur or with non-exfoliative fur groups were higher than that in the other groups (P<0.05). Concentrations of keratin 13 in the cells exfoliated from tongue fur in the groups of asthma or non-asthma with exfoliative fur were lower than that of the other groups (P<0.05). There was no significant difference of expression level of bcl-2 in the cells exfoliated from tongue fur among these five groups. CONCLUSION: There is a reasonably close relationship between the formation of exfoliative tongue fur and the immune system such as low level of serum cortisol and high levels of blood CD4(+) and CCR-3, which may all promote the formation of exfoliative fur. The disability of keratinization and apoptosis of epithelial cells of tongue may also be one cause for its formation.

Asthma↗
PubMed2005

[Study of relationship between ApoE epsilon4 allele and hippocampal atrophy in Alzheimer disease].

OBJECTIVE: To investigate the relationship between ApoE epsilon4 allele and hippocampal atrophy in patients with AD. METHODS: Using MRI-based volumetry technique and PCR-FRLP, the hippocampal volume and ApoE genotype of 34 AD patients were examined, and the difference in hippocampal volume between the ApoE epsilon4 positive AD group (n=17) and the ApoE epsilon4 negative AD group (n=17) was analyzed. The relationship between the number of ApoE epsilon4 allele and the hippocampal volume was also evaluated. RESULTS: The hippocampal volume of the ApoE epsilon4 positive AD group was significantly smaller than that of the ApoE epsilon4 negative AD group (t = 2.43, P < 0.05), and there was a negative relationship between the number of ApoE epsilon4 allele and the hippocampal volume (r(s) = -0.210, P = 0.0024). These implied: the more the number of ApoE epsilon4 allele a patient had, the smaller the hippocampal volume of the patient would be. CONCLUSION: In this study the relationship between ApoE epsilon4 allele and hippocampal atrophy of AD was noticeable and it might shed light on the possible role of ApoE epsilon4 in the pathogenesis of AD.

Aged↗
PubMed2005

[CH4 and N2O emission from a winter-time flooded paddy field in a hilly area of Southwest China].

By the method of static opaque chamber/modified gas chromatography, a one-year field experiment was conducted to measure in situ the CH4 and N2O emission from a winter-time flooded paddy field in a hilly area of Southwest China. Gas samples were taken simultaneously from rice-involved and rice-uninvolved plots. The results showed that during rice growth period, the CH4 emission from the winter-time flooded paddy field was higher than that from other paddy fields, but largely lower than many previous reports for the similar regions in Southwest China. The average flux of CH4 emission from rice-involved plots was 22.76 +/- 2.76 mg CH4 x m(-2) x h(-1) during rice growth period, 9.64 +/- 1.17 mg CH4 x m(-2) x h(-1) per year, and 1.43 +/- 0.20 mg CH4 x m(-2) x h(-1) during non-rice growth season; while that from rice-uninvolved plots was only 2.03 +/- 0.18 mg CH4 x m(-2) x h(-1) per year, markedly lower than those from rice-involved plots. During rice growth season, the mean emission rate of CH4 and N2O was 4.53 +/- 0.38 mg CH4 x m(-2) x h(-1) and 32.01 +/- 5.02 microg N2O x m(-2) x h(-1) from rice-uninvolved plots, but reached to 22.76 +/- 2.76 mg CH4 x m(-2) x h(-1) and 73.04 +/- 5.03 microg N2O x m(-2) x h(-1) from rice-involved plots, respectively. Rice involvement resulted in 302% increment of CH4 and 128% increment of N2O emission. There was a clear trade-off between CH4 and N2O emission in paddy fields. Even with a span of 500 years, our calculation showed that in this winter-time flooded paddy field, the GWP contributed by N2O production was 7.9% of the CH4 contribution, and thus, the greenhouse effect of N2O production from this field was very small.

Greenhouse Effect↗
PubMed2005

[Effects of uvulopalatopharyngoplasty surgery on subsequent continuous positive airway pressure in patients with obstructive sleep apnea-hypopnea syndrome].

OBJECTIVE: To determine the effect of uvulopalatopharyngoplasty (UPPP) therapy on post-surgery continuous positive airway pressure (CPAP) treatment during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS), and to evaluate the use of Bi-level positive airway pressure (BiPAP) in whom CPAP therapy failed. METHODS: Thirty-four OSAHS patients after UPPP surgery were tested more than 3 months after the procedure. Among them 25 patients were treated with classical UPPP (cUPPP), in which all of the uvula and part of the soft palate were removed. Nine underwent modified UPPP (mUPPP), keeping part of the uvula. The control group consisted of 34 age, body mass index (BMI) and apnea hypopnea index (AHI) matched, newly diagnosed OSAHS patients without prior treatment. Four patients receiving both pre- and post-surgery tests were included in both groups. A manual titration of CPAP to determine the optimal CPAP pressure (oCPAP) and the highest CPAP pressure (hCPAP) the patient can tolerate was performed during both NREM and REM sleep in all 68 patients. RESULTS: 72% of the UPPP patients had less than 50% decrease in AHI, and 82% of the 34 patients still had AHI > 15 during post-operation PSG test. Hence, most of them needed further therapy. All of the untreated OSAHS patients could tolerate 17-20 cm H2O of CPAP during NREM and REM sleep. None had severe mouth air leak before an oCPAP was reached. In contrast, five in the surgery group failed to respond to CPAP treatment during both NREM and REM sleep, and one more during REM sleep. All of the nine patients who had a mUPPP could tolerate CPAP. One of the four tested both before and after surgery failed to respond to CPAP treatment after surgery during REM sleep and one during both NREM and REM sleep. However, the six patients failed to respond to CPAP treatment tolerated BiPAP therapy well. CONCLUSIONS: In a considerable number of patients with OSAHS, UPPP may compromise the applicability of nasal CPAP as a subsequent therapy, and BiPAP might be a treatment option for patients who could not tolerate CPAP treatment.

Adult↗
PubMed2005

[Nanometer-size titanium dioxide separation/preconcentration and ICP-AES for the determination of Cd, Co and Zn].

The adsorption behavior of Cd, Co and Zn on nanometer-size TiQ2 was investigated. At pH 9.0, Cd, Co and Zn were retained on the nanometer-size TiO2, then eluted with 0.1 mol x L(-1) HNO3 and determined by ICP-AES. The adsorption capacities of nanometer TiO2 were found to be 8.1, 6.9 and 15.1 mg x g(-1) for Cd, Co and Zn respectively. The detection limits (3sigma) for Cd, Co and Zn are 5.1, 3.4 and 2.9 ng x mL(-1) respectively. The proposed method has been applied to the determination of trace Cd, Co and Zn in environmental samples with satisfactory results.

Adsorption↗
PubMed2005

[Detection of autoimmune parameter of SARS patients].

OBJECTIVE: To explore whether autoimmune phenomena exist in SARS patients, and to seek for unusual autoimmune antibodies in SARS patients. METHODS: Autoantibodies against cell nuclei (ANA), autoantibodies against smooth muscles (SMA), autoantibodies against parietal cells (PCA), autoantibodies against heart cells (HRA) were detected by using immunofluorescence, and autoantibodies against live-kidney microsomes (LKM) and anti-M2 antibodies were detected by ELISA in sera taken from 27 SARS patients and 18 healthy controls. Immunofluorescence was used to localize the targets antigens in slides with biochips of lung (monkey) of SARS associated antibodies. RESULTS: ANA, AMA, LKM and SMA were found positive in 3, 1, 1, and 1 of the 27 SARS sera. In 18 healthy control sera, one ANA and one AMA were positive. Statistical analysis showed that there were no difference between two groups in every item detected. Twenty-six of 27 SARS patients and 5 of 18 healthy controls had strongly stained columnar epithelia of the bronchiole, especially the lumen border of the epithelia?the difference between two groups was significant. CONCLUSION: No antibodies against organs but lung were found in SARS patients. There are auto antibodies against lung tissues in sera of SARS patients.

Adolescent↗
PubMed2005

[Relationship between congenital long QT syndrome and Brugada syndrome gene mutation].

OBJECTIVE: To investigate the molecular pathology in families with long QT syndrome (LQTS) including Jervell-Longe-Nielsen syndrome (JLNS) and Romano-ward syndrome (RWS) and Brugada syndrome (BS) in Chinese population. METHODS: Polymerase chain reaction and DNA sequencing were used to screen for KCNQ1, KCNH2, KCNE1, and SCN5A mutation. RESULTS: We identified a novel mutation N1774S in the SCN5A gene of the BS family, a novel mutation G314S in a RWS family which had also been found in Europe, North America, and Japan, and a single nucleotide polymorphisms (SNPs) G643S in the KCNQ1 of the JLNS family. In this JLNS family, another heterozygous novel mutation in exon 2a was found in KCNQ1 of the patients. CONCLUSION: New mutations were found in our experiment, which expand the spectrum of KCNQ1 and SCN5A mutations that cause LQTS and BS.

Adolescent↗
PubMed2005

[The effect of carvedilol on cardiac function and autoantibodies against the cardiac receptors].

OBJECTIVE: To evaluate the effect of carvedilol on the cardiac function and autoantibodies against the cardiac beta(1), beta(2) and alpha(1)-adrenergic receptors in patients with chronic heart failure (CHF). METHODS: 54 patients with CHF were divided randomly into two groups, one was regular treatment group treated with ACE inhibitor, digoxin and diuretic, another was carvedilol treatment group treated with carvedilol on the basis of above regular treatment. All the patients were followed up for six months and measured the changes of cardiac function and three autoantibodies by echocardiography and enzyme-linked immunosorbent assay (ELISA) respectively. RESULTS: (1) After carvedilol treatment, LVEDD and LVESD (57.50 +/- 7.29) mm and (43.17 +/- 8.27) mm were smaller than that in regular treatment group [(64.09 +/- 7.40) mm and (52.93 +/- 8.35) mm], and LVEF [(50.41 +/- 10.91)%] was higher than that [(41.70 +/- 7.45)%] in regular treatment group (P < 0.01). (2) After carvedilol treatment, the positive ratios and average titers of autoantibodies against the cardiac beta(1), beta(2) and alpha(1)-adrenergic receptors all decreased significantly compared with that of pre-treatment (P < 0.05). The positive ratios of autoantibodies against the three receptors in carvedilol treatment group were lower than those in regular treatment group (P < 0.05). The average titers of autoantibodies against the cardiac beta(1), beta(2) and alpha(1)-adrenergic receptors in carvedilol treatment group (1:72.44, 1:61.66 and 1:67.30) were lower than those in regular treatment group (1:113.24, 1:110.66 and 1:113.24), P < 0.05. CONCLUSIONS: Carvedilol decreased positive ratio and average titer of autoantibodies against the beta(1), beta(2) and alpha(1) receptors accompanied with the obvious improvement of cardiac function though the blockade of beta(1), beta(2) and alpha(1) receptors. It suggests that the autoantibodies might be involved in the process of pathophysiology and development of CHF. Carvedilol can inhibit this process.

Adult↗
PubMed2005

[The relationship between central corneal thickness and Perkins applanation tonometry in rabbits].

OBJECTIVE: To investigate the relationship between central corneal thickness (CCT) and Perkins applanation tonometry and establish a mathematic model of correlation between true intraocular pressure (IOP), CCT and Perkins applanation tonometry. METHODS: The study included thirty-two new Zealand rabbits. One eye received excimer laser photorefractive keratectomy (PRK), the other eye was used as control. The eye selected randomly according to stochastic digital chart received PRK to thin the central cornea and to generate different central corneal thickness. The Perkins applanation tonometry, CCT, corneal curvature (CC) were measured by Perkins applanation tonometer, ultrasonic pachymetry and keratometer pre- and post-PRK. Direct intracameral IOP readings was measured by IOP transducer. Statistical analyses were performed with the Pearson correlation coefficient and stepwise regression analysis. RESULTS: There is no difference in the measurement of Perkins applanation tonometry, CCT and CC between experimental and controls. A significant correlation was found between IOP and CCT pre- and post-PRK (r = 0.761, P < 0.05; r = 0.829 P < 0.05). There is correlation between IOP and CC, (r = 0.098, P > 0.05; r = 0.260, P > 0.05). The slope of CCT was 0.066 mm Hg/micron pre-PRK and 0.053 mm Hg/micron post-PRK. However, the change of IOP correlated with CCT. Regression equation for direct intracameral IOP Y = 12.107 + 1.254X(1) - 0.033X(2) (X(1) = Perkins applanation tonometry, X(2) = CCT). CONCLUSIONS: CCT is an important variable in the evaluation of applanation IOP and should be considered when the Perkins applanation tonometry was taken.

Animals↗