Biomedical subjects

Qiang Fu

Publications and source records attributed to Qiang Fu.

At least 91 records · Page 5Linked to original sources

PubMed2004

Examination of surface roughness on light scattering by long ice columns by use of a two-dimensional finite-difference time-domain algorithm.

Natural particles such as ice crystals in cirrus clouds generally are not pristine but have additional microroughness on their surfaces. A two-dimensional finite-difference time-domain (FDTD) program with a perfectly matched layer absorbing boundary condition is developed to calculate the effect of surface roughness on light scattering by long ice columns. When we use a spatial cell size of 1/120 incident wavelength for ice circular cylinders with size parameters of 6 and 24 at wavelengths of 0.55 and 10.8 microm, respectively, the errors in the FDTD results in the extinction, scattering, and absorption efficiencies are smaller than approximately 0.5%. The errors in the FDTD results in the asymmetry factor are smaller than approximately 0.05%. The errors in the FDTD results in the phase-matrix elements are smaller than approximately 5%. By adding a pseudorandom change as great as 10% of the radius of a cylinder, we calculate the scattering properties of randomly oriented rough-surfaced ice columns. We conclude that, although the effect of small surface roughness on light scattering is negligible, the scattering phase-matrix elements change significantly for particles with large surface roughness. The roughness on the particle surface can make the conventional phase function smooth. The most significant effect of the surface roughness is the decay of polarization of the scattered light.

Journal Article↗

PubMed2004

Genetic epidemiology of alcohol-induced blackouts.

BACKGROUND: Alcohol-induced blackouts (ie, periods of anterograde amnesia) have received limited recent research attention. OBJECTIVE: To examine the genetic epidemiology of lifetime blackouts and having had 3 or more blackouts in a year, including analyses controlling for the frequency of intoxication. DESIGN, SETTING, AND PARTICIPANTS: Members of the young adult Australian Twin Register, a volunteer twin panel born between January 1, 1964, and December 31, 1971, were initially registered with the panel as children by their parents between 1980 and 1982. They underwent structured psychiatric telephone interviews from February 1996 through September 2000. The current sample contains 2324 monozygotic and dizygotic twin pairs (mean [SD] age 29.9 [2.5] years) for whom both twins' responses were coded for blackout questions and for frequency of intoxication. MAIN OUTCOME MEASURE: Outcome Measure Data on lifetime blackouts and having had 3 or more blackouts in a year were collected within an examination of the genetic epidemiology of alcoholism. RESULTS: A lifetime history of blackouts was reported by 39.3% of women and 52.4% of men; 11.4% of women and 20.9% of men reported having had 3 or more blackouts in a year. The heritability of lifetime blackouts was 52.5% and that of having had 3 or more blackouts in a year was 57.8%. Models that controlled for frequency of intoxication found evidence of substantial genetic contribution unique to risk for the blackouts and a significant component of genetic risk shared with frequency of intoxication. CONCLUSIONS: The finding of a substantial genetic contribution to liability for alcohol-induced blackouts including a component of genetic loading shared with frequency of intoxication may offer important additional avenues to investigate susceptibility to alcohol-related problems.

Adult↗

PubMed2004

Preparation and characterization of a novel bioactive bone cement: glass based nanoscale hydroxyapatite bone cement.

A novel type of glass-based nanoscale hydorxypatite (HAP) bioactive bone cement (designed as GBNHAPC) was synthesized by adding nanoscale hydroxyapatite (HAP) crystalline (20-40 nm), into the self-setting glass-based bone cement (GBC). The inhibition rate of nanoscale HAP and micron HAP on osteosarcoma U2-OS cells was examined. The effects of nanoscale HAP on the crystal phase, microstructure and compressive strength of GBNHAPC were studied respectively. It was concluded that nanoscale HAP could inhibit the cell proliferation, while micron HAP could not, and that nanoscale HAP could be dispersed in the cement evenly and the morphology did not change significantly after a longer immersion time. XRD and FTIR results show nanoscale HAP did not affect the setting reaction of the cement. Furthermore, GBNHAPC had a higher compressive strength (92 MPa) than GBC. It was believed that GBNHAPC might be a desirable biomaterial that could not only fill bone defects but also inhibit cancer cell growth.

Bone Cements↗

PubMed2004

[Effect of purified pre-beta 1 HDL on efflux of 3H-cholesterol loaded in human smooth muscle cells].

OBJECTIVE: To compare the effects of different HDL subclasses on the efflux of 3H-cholesterol loaded human smooth muscle cells (SMCS). METHODS: 3H-cholesterol loaded human SMCS were incubated with purified pre-beta 1 HDL, alpha-HDL and apoE-deficient HDL3 respectively. The cholesterol effluxing capacity and incubating time of different HDL subclasses were detected, and were analysed by double-reciprocal mapping. RESULTS: It was found that the value of Emax of pre-beta 1 HDL is higher than that of alpha-HDL and apoE-deficient HDL3 (P < 0.01), and the value of Ke of pre-beta 1 HDL is lower than that of alpha-HDL and apoE-deficient HDL3 (P < 0.01). CONCLUSION: The results showed the effluxing capacity and efficiency of pre-beta 1 HDL were greater than those of alpha-HDL and apoE-deficient HDL3, thus suggesting that pre-beta 1 HDL is a more efficient acceptor of cell-derived 3H-cholesterol.

Aorta↗

PubMed2004

[First-line Xeloda (Capecitabine) treatment for advanced and recurrent colorectal cancer].

OBJECTIVE: To evaluate the efficacy and safety of capecitabine as first-line therapy in patients with advanced and recurrent colorectal cancer. METHODS: From December 2000 to November 2001, sixty patients with advanced and recurrent colorectal cancer received first-line capecitabine treatment given at a dose of 1250 mg/m(2) twice daily, on days 1 - 14 every 21 days. At least 2 cycles were administered. RESULTS: The overall response rate was 23.3% with 14 PR, 24 SD (40.0%) and 15 PD. The median survival time was 14.7 months. The survival rate was 63.9% at 12-months and 33.4% at 24-months. Grade III-IV adverse effects were diarrhea in 4 patients (6.6%), anemia in 2 (3.3%) and hand-foot syndrome (HFS) in 1 (1.7%); Grade I-II adverse effects were hyperpigmentation in 20 (33.3%), HFS in 18 (30.0%) and diarrhea in 10 (16.7%). CONCLUSION: Capecitabine is an efficacious and better-tolerated alternative treatment for the patients with advanced and recurrent colorectal cancer.

Adult↗

PubMed2004

[Effect of herceptin combined with Doxorubicin on rat cardiotoxicity].

BACKGROUND & OBJECTIVE: Herceptin is a humanized monoclonal antibody for treating the patients with metastatic breast cancers overexpressing human epidermal growth factor receptor (HER-2). Herceptin combined with doxorubicin markedly increased the incidence of cardiac dysfunction in clinical trials. The current study was designed to investigate the cardiotoxicity aggravated by Herceptin combined with doxorubicin in rats. METHODS: Thirty-six female rats were randomized into four groups (n=9): control group, Herceptin group, doxorubicin group, Herceptin combined with doxorubicin group. The value of malon dialdehyde (MDA) was measured by thiobarbituric acid (TBA) method and the activity of glutathione peroxidase (GSH-Px) was measured by 5,5'-dithiobis-2-nitrobenzoic acid (DTNB) method. The damage and apoptosis of myocardium were observed by electron microscopy and tdt-mediated dUTP nick end labeling (TUNEL). The ratio of myocardial apoptosis cells was quantified using flow cytometry. RESULTS: The value of MDA in control group and Herceptin group were (0.70+/-0.03) and (0.73+/-0.05) nmol x(mg x protein)(-1), respectively; the activity of GSH-PX in control group and Herceptin group were (81.31+/-0.13) and (78.43+/-0.15) U x(mg x protein)(-1),respectively;the two groups were similar. The value of MDA in doxorubicin group and Herceptin combined with doxorubicin group were (0.88+/-0.10) and (0.94+/-0.13) nmol x(mg x protein)(-1), respectively; the activity of GSH-PX in doxorubicin group and Herceptin combined with doxorubicin group were(67.88+/-0.24) and(63.37+/-0.28) U x(mg x protein)(-1),respectively. The most prominent ultrastructural damages were mitochondrial swelling with fragmentation of cristae and vacuoles formation in doxorubicin group and Herceptin combined with doxorubicin group. Herceptin markedly increased the ratio of apoptosis of myocardial cells from (5.35+/-0.27) % in doxorubicin group to (8.27+/-0.38) % in Herceptin combined with doxorubicin group as measured by flow cytometry (P< 0.05). CONCLUSION: Herceptin alone had little toxic effects on rat cardiomocytes, but Herceptin combined with doxorubicin can aggravate rat cardiotoxicity. Herceptin can also increase the number of the apoptosis cell in rat myocardium.

Animals↗

PubMed2004

[Influence of Shenshuai Capsule on renal tissue apoptosis of rats with chronic renal failure].

OBJECTIVE: To explore the influence of Shenshuai Capsule on renal tissue apoptosis of Wistar rats with chronic renal failure. METHOD: Wistar rats were fed with adenine to establish chronic renal failure model, and then they were divided into three groups separately fed with Shenshuai capsule (high or low dosage) and Niaoduqing. RIA, immunohistochemical method and electron microscopy were used. RESULTS: The parameters of renal function between the treatment group (high dosage) and the Niaoduqing group were significantly different respectively. Shenshuai capsule could inhibit tubular epicyte apoptosis and Fas genetic expression, and improve Bcl-2 genetic expression. CONCLUSION: Shenshuai capsule could inhibit epicyte apoptosis, and adjust Fas genetic expression. Bcl-2 genetic expression indicated that this may be one of the mechanism to postpone the renal failure by Shunshuai capsule.

Adenine↗

PubMed2004

[Insight into surface structure and hemocompatibility of fluorinated poly(ether urethane)s and poly(ether urethane)s blends].

It has been well known that fluorinated polyurethanes exhibit unique low surface energy, biocompatibility, biostability and nonsticking behavior. Consequently, these polymers have attracted considerable interest. In this study, the effect of various concentrations of fluorinated polyurethanes in the polyurethanes on the surface structures of the blends and their hemocompatibility were investigated by XPS, AFM, contact angle and platelet adhesion. It was found that the high concentration fluorine on the outer surfaces of the blends obtained with the low concentration of fluorinated polyurethanes (F: 0.342 wt%) in the blends was the same as that of the fluorinated poly(ether urethane)s, and all of the blends and the fluorinated poly(ether urethane)s had good hemocompatibility, compared with poly(ether urethane)s. The polymer blends and fluorinated poly(ether urethane)s suppressed platelet adhesion due to their high hydrophobicity and low surface tension. The XPS, AMF and contact angle results indicated that the high hydrophobicity of outer surface of the polyurethane blends is independent of the fluorinated polyurethanes content in the polymer blends but related to the concentration of the CF3 groups because the lower critical surface tensions and higher contact angle of many fluorinated surfaces reflect the concentration of CF3 groups.

Coated Materials, Biocompatible↗

PubMed2004

[Effect of S-2-(3-aminopropylamino) ethyl phosphorothioic acid on apoptosis and proliferation inhibition of HL-60 cell line].

To study the effects of S-2-(3-aminopropylamino) ethyl phosphorothioic acid (WR-2721, amifostine) on proliferation inhibition and apoptosis of HL-60 human leukemia cell line, the cell apoptosis rate of HL-60 was determined by annexin V/PI double staining method. Cell proliferation and chemotherapy sensitivity were analyzed with XTT assay, and the changes of cell cycle were observed through flow cytometry. The results showed that WR-2721 could significantly inhibit HL-60 cell proliferation. After treatment (30 min, 37 degrees C) with WR-2721, the sensitivity of HL-60 cells to VP16 was enhanced, and the IC(50) descended from 52.5 micro g/ml to 40.5 microg/ml. After 72 hours treatment of HL-60 cells with WR-2721, the early apoptotic cells (annexin V-FITC positive/PI negative) were increased from (5.5 +/- 1.9)% to (48.5 +/- 8.4)% (P < 0.001), late apoptotic cells (annexin V-FITC positive/PI positive) were increased from (1.2 +/- 0.5)% to (39.0 +/- 4.0)% (P < 0.001), and HL-60 cells were arrested in G(2)-M phase. In conclusion, WR-2721 treatment can enhance HL-60 cell chemotherapy sensitivity to VP16, inhibit proliferation, induce apoptosis and accumulation of cells in G(2)-M phase.

Amifostine↗

PubMed2004

[Pyramiding of senescence-inhibition IPT gene and Xa23 for resistance to bacterial blight in rice (Oryza sativa L.)].

Transgenic lines (GC-1) carrying a senescence-inhibition cheimeric gene, IPT (isopentenyl transferase) gene, CBB23, a isogenic lines carrying Xa23 gene for resistance to bacterial blight, and Hexi15, a commercial cultivar showing high resistance to blast disease, were used as donors to pyramid IPT gene and Xa23 by marker-assisted selection (MAS). Seventeen BC1F1 plants pyramiding Xa23 gene and IPT genes were obtained from three multi-cross combinations. Then, the plants carrying Xa23 and IPT genes were crossed with parental lines of two-line hybrid rice, such as 9311, E32, Pei' ai 64S and W9834S. The progenies were backcrossed the acceptor parents. A total of 17 plants carrying Xa23 and IPT genes were detected by PCR, disease resistance identification and analysis of CTK contents of in the four combinations of "(9311///Hexi15/CBB23// GC-1) x 9311", "(E32///Hexi15/CBB23//GC-1) x E32", "(Pei'ai 64S///Hexi15/CBB23//GC-1) x Pei' ai 64S" and "(GC-1/CBB23//W9834S/Hexi15) x W9834S". These plants showed resistance to blast disease by inoculating test using 21 the lines of Pyricularia grisea from Northern China. Six plants of BC2F1 pyramiding Xa23 and IPT genes were further obtained in the combinations of "[(9311///Hexi15/CBB23//GC-1) x 9311] x 9311", "[(E32///Hexi15/CBB23//GC-1) x E32] x E32". After backcrossed and self-crossed 1 approximately 2nd, the plants pyramiding Xa23 and IPT genes can be used in the program of hybrid rice breeding.

Alkyl and Aryl Transferases↗

PubMed2003

Proteasomal degradation of Runx2 shortens parathyroid hormone-induced anti-apoptotic signaling in osteoblasts. A putative explanation for why intermittent administration is needed for bone anabolism.

It is unknown why sustained elevation of parathyroid hormone (PTH) stimulates bone resorption, whereas intermittent administration stimulates bone formation. We show in mice that daily injections of PTH attenuate osteoblast apoptosis, thereby increasing osteoblast number, bone formation rate, and bone mass, but do not affect osteoclast number. In contrast, sustained elevation of PTH, achieved either by infusion or by raising endogenous hormone secretion with a calcium-deficient diet, does not affect osteoblast apoptosis but increases osteoclast number. Attenuation of apoptosis by PTH in cultured osteoblastic cells requires protein kinase A-mediated phosphorylation and inactivation of the pro-apoptotic protein Bad as well as transcription of survival genes, like Bcl-2, mediated by CREB (cAMP response element-binding protein) and Runx2. But, PTH also increases proteasomal proteolysis of Runx2. Moreover, the anti-apoptotic effect of PTH is prolonged by inhibition of proteasomal activity, by overexpressing a dominant negative form of the E3 ligase (ubiquitin-protein isopeptide ligase) that targets Runx2 for degradation (Smurf1), or by overexpressing Runx2 itself. The duration of the anti-apoptotic effect of PTH, thus, depends on the level of Runx2, which in turn is decreased by PTH via Smurf1-mediated proteasomal proteolysis. The self-limiting nature of PTH-induced survival signaling might explain why intermittent administration of the hormone is required for bone anabolism.

Animals↗

PubMed2003

Isolation and analyses of genes preferentially expressed during early cotton fiber development by subtractive PCR and cDNA array.

Cotton fibers are differentiated epidermal cells originating from the outer integuments of the ovule. To identify genes involved in cotton fiber elongation, we performed subtractive PCR using cDNA prepared from 10 days post anthesis (d.p.a.) wild-type cotton fiber as tester and cDNA from a fuzzless-lintless (fl) mutant as driver. We recovered 280 independent cDNA fragments including most of the previously published cotton fiber-related genes. cDNA macroarrays showed that 172 genes were significantly up-regulated in elongating cotton fibers as confirmed by in situ hybridization in representative cases. Twenty-nine cDNAs, including a putative vacuolar (H+)-ATPase catalytic subunit, a kinesin-like calmodulin binding protein, several arabinogalactan proteins and key enzymes involved in long chain fatty acid biosynthesis, accumulated to greater than 50-fold in 10 d.p.a. fiber cells when compared to that in 0 d.p.a. ovules. Various upstream pathways, such as auxin signal transduction, the MAPK pathway and profilin- and expansin-induced cell wall loosening, were also activated during the fast fiber elongation period. This report constitutes the first systematic analysis of genes involved in cotton fiber development. Our results suggest that a concerted mechanism involving multiple cellular pathways is responsible for cotton fiber elongation.

Cell Division↗

PubMed2003

Diffusion-corrected simultaneous multilayer growth model.

A diffusion-corrected simultaneous multilayer (DCSM) model was developed, taking into account up-step and down-step diffusion of adatoms and enabling rapid identification of different film growth modes. This DCSM model was applied to the initial growth of Cr on (100) SrTiO3 and (0001) alpha-Al2O3 surfaces, monitoring the deposition process by in situ Auger electron spectroscopy. We conclude with general remarks on the usefulness of the DCSM model for exploiting solid state wetting processes of thin metal films on different substrates.

Journal Article↗

PubMed2003

Uniformly sized molecularly imprinted polymer for (S)-nilvadipine. Comparison of chiral recognition ability with HPLC chiral stationary phases based on a protein.

Uniformly sized molecularly imprinted polymers (MIPs) for (S)-nilvadipine have been prepared by a multistep swelling and polymerization method using methacrylic acid, 2-(trifluoromethyl)acrylic acid, 2-vinylpyridine, or 4-vinylpyridine (4-VPY) as a functional monomer and ethylene glycol dimethacrylate (EDMA) as a cross-linker. The chiral recognition abilities of the MIPs for nilvadipine and other dihydropyridine calcium antagonists were evaluated using a mixture of sodium phosphate buffer (or water) and acetonitrile or only acetonitrile as the mobile phase. The (S)-nilvadipine-imprinted 4-VPY-co-EDMA polymers gave the highest resolution for nilvadipine among the MIPs prepared. In addition, the enantioseparation of nilvadipine was attained using the (S)-nilvadipine-imprinted EDMA polymers, without use of a functional monomer. 1H NMR and molecular modeling studies suggested a one-to-one hydrogen-bonding-based complex formation of (S)-nilvadipine with 4-VPY in chloroform. These results reveal that the (S)-nilvadipine-imprinted EDMA polymers could recognize the template molecule by its molecular shape, and that in addition to this recognition, hydrophobic and hydrogen-bonding interactions seems to play important roles in the retention and chiral recognition of nilvadipine on the 4-VPY-co-EDMA polymers in hydroorganic mobile phases. By optimizing chromatographic conditions such as column temperature and flow rate, the baseline separation of nilvadipine enantiomers was attained with a short analysis time and with a column efficiency comparable to commercially available chiral stationary phases based on a protein, such as ovomucoid or alpha1-acid glycoprotein.

Adsorption↗

PubMed2003

Genetic and environmental effects on offspring alcoholism: new insights using an offspring-of-twins design.

CONTEXT: Although there is now considerable evidence that genetic effects play a critical role in the development of alcohol dependence (AD), theoretical and methodological limitations of this literature require caution in describing the etiology and development of this disorder. OBJECTIVE: To disentangle genetic and environmental effects on AD by means of the infrequently used, yet potentially powerful, offspring-of-twins design. DESIGN: Offspring of twins. PARTICIPANTS: Male monozygotic and dizygotic twins concordant or discordant for AD and control pairs from the Vietnam Era Twin Registry were assessed, as were the offspring of these twins and the mothers of these offspring. INTERVENTIONS: Structured psychiatric interviews. MAIN OUTCOME MEASURES: Participants' psychiatric, alcohol abuse (AA), and AD histories (DSM-IV). RESULTS: Offspring of monozygotic and dizygotic twins with a history of AD were significantly more likely to exhibit AA or AD than were offspring of nonalcoholic fathers. Offspring of an alcohol-abusing monozygotic twin whose co-twin was AD were also more likely to exhibit AD than were offspring of nonalcoholic twins. In contrast, offspring of an unaffected (ie, no history of abuse or dependence) monozygotic twin whose co-twin was AD were no more likely to exhibit AA or AD than were offspring of nonalcoholic twins. CONCLUSIONS: These findings support the hypothesis that family environmental effects do make a difference in accounting for offspring outcomes, in particular, that a low-risk environment (ie, the absence of parental alcoholism) can moderate the impact of high genetic risk regarding offspring for the development of alcohol-use disorders.

Adolescent↗

PubMed2003

Using mobile information technology to build a database for anesthesia quality control and to provide clinical guidelines.

The paper describes a mobile information system to collect patient information for anaesthesia quality control. In this system we use handheld computers, to collect patient data at the bedside with a daily synchronization of the data of the anaesthesiologist's handheld with the anaesthesia database center, later used for quality control analysis. Further, we design mobile clinical guidelines to be used on the same handhelds.

Anesthesia↗

PubMed2002

Parathyroid hormone stimulates receptor activator of NFkappa B ligand and inhibits osteoprotegerin expression via protein kinase A activation of cAMP-response element-binding protein.

Parathyroid hormone (PTH) stimulates osteoclast formation by binding to its receptor on stromal/osteoblastic cells and stimulating the production of receptor activator of NFkappaB ligand (RANKL) and inhibiting the expression of osteoprotegerin (OPG). However, the mechanisms through which PTH regulates these genes remain unknown. Here we report that PTH stimulated RANKL gene transcription and increased RANKL mRNA stability in murine stromal/osteoblastic cells stably expressing human PTH/PTH-related protein receptor 1. PTH also potently suppressed OPG mRNA in these cells. Cycloheximide did not block the effects of PTH on RANKL but did inhibit the suppression of OPG mRNA. Activation of protein kinase A (PKA) was necessary and sufficient for the effect of PTH on both genes. Conditional expression of a dominant-negative form of the transcription factor CREB, but not c-fos or Runx2, significantly reduced PTH stimulation of RANKL. CREB activity was also required for full stimulation of RANKL by oncostatin M or 1,25-dihydroxyvitamin D(3). Dominant-negative forms of CREB and c-fos reduced the suppression of OPG by PTH. These results demonstrate that PTH directly stimulates RANKL expression via a PKA-CREB pathway and that CREB may be a central regulator of RANKL expression. Furthermore, they suggest that PTH suppression of OPG involves CREB and c-fos.

Animals↗

PubMed2002

Finite-difference time-domain solution of light scattering and absorption by particles in an absorbing medium.

The three-dimensional (3-D) finite-difference time-domain (FDTD) technique has been extended to simulate light scattering and absorption by nonspherical particles embedded in an absorbing dielectric medium. A uniaxial perfectly matched layer (UPML) absorbing boundary condition is used to truncate the computational domain. When computing the single-scattering properties of a particle in an absorbing dielectric medium, we derive the single-scattering properties including scattering phase functions, extinction, and absorption efficiencies using a volume integration of the internal field. A Mie solution for light scattering and absorption by spherical particles in an absorbing medium is used to examine the accuracy of the 3-D UPML FDTD code. It is found that the errors in the extinction and absorption efficiencies from the 3-D UPML FDTD are less than approximately 2%. The errors in the scattering phase functions are typically less than approximately 5%. The errors in the asymmetry factors are less than approximately 0.1%. For light scattering by particles in free space, the accuracy of the 3-D UPML FDTD scheme is similar to a previous model [Appl. Opt. 38, 3141 (1999)].

Journal Article↗