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Biomedical subjects

Q Wang

Publications and source records attributed to Q Wang.

At least 73 records · Page 4Linked to original sources
PubMed2005

Arrangement of high-energy neutron irradiation field and shielding experiment using 4 m concrete at KENS.

An irradiation field of high-energy neutrons produced in the forward direction from a thick tungsten target bombarded by 500 MeV protons was arranged at the KENS spallation neutron source facility. In this facility, shielding experiment was performed with an ordinary concrete shield of 4 m thickness assembled in the irradiation room, 2.5 m downstream from the target centre. Activation detectors of bismuth, aluminium, indium and gold were inserted into eight slots inside the shield and attenuations of neutron reaction rates were obtained by measurements of gamma-rays from the activation detectors. A MARS14 Monte Carlo simulation was also performed down to thermal energy, and comparisons between the calculations and measurements show agreements within a factor of 3. This neutron field is useful for studies of shielding, activation and radiation damage of materials for high-energy neutrons, and experimental data are useful to check the accuracies of the transmission and activation calculation codes.

Computer Simulation↗
PubMed2005

Association analysis of the RGS4 gene in Han Chinese and Scottish populations with schizophrenia.

We investigated the RGS4 as a susceptibility gene for schizophrenia in Chinese Han (184 trios and 138 sibling pairs, a total of 322 families) and Scottish (580 cases and 620 controls) populations using both a family trio and case-control design. Both the samples had statistical power greater than 70% to detect a heterozygote genotype relative risk of >1.2 for frequent RGS4-risk alleles. We genotyped four single nucleotide polymorphisms (SNPs) which have previously been associated with schizophrenia as either individually or part of haplotypes. Allele frequencies and linkage disequilibrium between the SNPs was similar in the two populations. In the Chinese sample, no individual SNPs or any of their haplotypes were associated with schizophrenia. In the Scottish population, one SNP (SNP7) was significantly over-represented in the cases compared with the controls (0.44 vs. 0.38; A allele; chi(2) 7.08, P = 0.011 after correction for correlation between markers by permutation testing). One two-marker haplotype, composed of alleles T and A of SNP4 and SNP7, respectively, showed individual significance after correction by permutation testing (chi(2) 6.8; P = 0.04). None of the full four-marker haplotypes showed association, including the G-G-G-G haplotype previously associated with schizophrenia in more than one sample and the A-T-A-A haplotype. Thus, our data do not directly replicate previous associations of RGS4, but association with SNP 7 in the Scottish population provides some support for a role in schizophrenia susceptibility. We cannot conclusively exclude RGS4, as associated haplotypes are likely to be surrogates for unknown causative alleles, whose relationship with overlying haplotypes may differ between the population groups. Differences in the association seen across the two populations could result from methodological factors such as diagnostic differences but most likely result from ethnic differences in haplotype structures within RGS4.

Case-Control Studies↗
PubMed2005

Self-assembly of the recombinant capsid protein of a bovine norovirus (BoNV) into virus-like particles and evaluation of cross-reactivity of BoNV with human noroviruses.

None of the enteric caliciviruses except Po/Sapo/GIII/Cowden/80/US replicates in cell culture, which complicates efforts to develop control strategies or to study viral replication. To develop serological assays for bovine noroviruses (BoNVs) and to determine the cross-reactivity of BoNV with human noroviruses, we generated two recombinant baculoviruses, rCV186-OH and rJNCV, to express the capsid genes of Bo/CV186-OH/00/US (Norovirus genogroup III [GIII], genotype 2 [GIII/2]). rCV186-OH expressed the expected 57-kDa capsid protein, but rJNCV expressed a truncated capsid protein of 35 kDa. Sequence analysis of rJNCV identified a single nucleotide deletion in the P domain of the capsid gene, which introduced a stop codon at amino acid 323. The recombinant capsid protein produced by rCV186-OH but not that produced by rJNCV self-assembled into virus-like particles (VLPs) similar to native BoNV. An antibody-capture enzyme-linked immunosorbent assay (ELISA) and antigen-capture ELISA (Ag-ELISA) detected serum antibody and antigen, respectively, from calves infected with Bo/CV186-OH/00/US but not antibodies or antigens to other enteric viruses. In other tests of the GIII/2 BoNV Ag-ELISA, no cross-reactivity was observed with VLPs from one GI and four GII human noroviruses and porcine sapovirus Cowden strain. Because, like human noroviruses, BoNVs do not grow in cell culture, the BoNV VLPs will be useful in the serological assays described for the detection of BoNV antibody and antigen. Consistent with the phylogenetic analysis of the capsid genes of bovine and human noroviruses (M. G. Han, J. R. Smiley, C. Thomas, and L. J. Saif, J. Clin. Microbiol. 42:5214-5224, 2004), the results suggest that GIII/2 BoNV does not share significant antigenic relationships with the five characterized human noroviruses tested.

Animals↗
PubMed2005

[Study of Shugan Yiyang capsule on erectile dysfunction].

OBJECTIVE: To study the pharmacological effect of Shugan Yiyang(SGYY) capsule. METHOD: kongming mice and Wistar rats were used to observe the effects of SGYY capsule on sexual desire, erection, ejaculation and fatigue. The weight of prostate, seminal vesicle, testes, levators and thymus and serum testosterone level were also measured. Furthermore, Rhesus monkey were used to construct animal model of erectile dysfunction. Effects of SGYY capsule on sexual behavior, penile blood flow and electromyogram were observed. RESULT: SGYY capsule can remarkably reduce the incubation period of erection, ejaculation and innovate the sexual desire,erection, ejaculation both on rats and rhesus monkeys. The weight of prostate, seminal vesicle, testes, levators in mice and serum testosterone level of rats increased while the weight of thymus decreased. It can also diminish the luminar of vein and reduce the venous outflow while the transmission of peripheral nervous system remained stable. CONCLUSION: SGYY capsule can remarkably improve the erectile activity, sexual desire and ejaculatory activity. The mechanism of SGYY capsule may be related to the increase of androgen and adrenocorticohormone levels. as well as the reduction of penile venous outflow. [Key words] shuganyiyang capsule; er

Animals↗
PubMed2004

Electronic structure and bonding of Au on a SiO2 cluster: a nanobullet for tumors.

The binding of gold atoms to a small silica cluster has been studied by using density functional theory with generalized gradient approximation for exchange and correlation. It is shown that gold atoms bind to silicon atoms with dangling bonds and serve as seeds for the growth of Au islands. The large electron affinity of gold causes a significant change in the electronic structure of silica resulting in a substantial reduction in the highest occupied and the lowest unoccupied molecular orbital and the optical gap, thus allowing it to absorb near infrared radiation. This suggests that a small cluster can have a similar functionality in the treatment of cancer as the large size nanoshell, but for a different mechanism.

Breast Neoplasms↗
PubMed2004

Antiferromagnetic coupling driven by bond length contraction near the Ga1-xMnxN film surface.

Using first principles calculations based on gradient corrected density functional theory we show that Mn atoms, which couple ferromagnetically in bulk Ga1-xMnxN, couple antiferromagnetically on its surface. This change in magnetic behavior is brought about by a contraction of the Mn-Mn and Mn-N bond lengths, which is significantly greater on the surface than in the bulk. The present study provides new insight to the numerous conflicting experimental observations in Mn doped GaN systems.

Journal Article↗
PubMed2004

Epstein-Barr virus latent membrane protein 1 (LMP1) upregulates Id1 expression in nasopharyngeal epithelial cells.

Nasopharyngeal carcinoma is closely associated with Epstein-Barr virus (EBV) infection. The EBV-encoded LMP1 has cell transformation property. It suppresses cellular senescence and enhances cell survival in various cell types. Many of the downstream events of LMP1 expression are mediated through its ability to activate NF-kappaB. In this study, we report a novel function of LMP1 to induce Id1 expression in nasopharyngeal epithelial cells (NP69) and human embryonal kidney cells (HEK293). The Id1 is a basic helix-loop-helix (bHLH) protein and a negative transcriptional regulator of p16(INK4a). Expression of Id1 facilitates cellular immortalization and stimulates cell proliferation. With the combination of both specific chemical inhibitors and genetic inhibitors of cell signaling, we showed that induction of Id1 by LMP1 was dependent on its NF-kappaB activation domain at the carboxy-terminal region, CTAR1 and CTAR2. Induction of Id1 by LMP1 may facilitate clonal expansion of premalignant nasopharyngeal epithelial cells infected with EBV and may promote their malignant transformation.

Carcinoma↗
PubMed2004

Evaluation of the pharmacokinetics and pharmacodynamics of intravenous lansoprazole.

AIM: To compare the pharmacokinetics and pharmacodynamics of lansoprazole 30 mg administered intravenously in 0.9% NaCl or in polyethylene glycol, or orally. METHODS: Twenty-nine subjects received lansoprazole orally on days 1-7 and intravenous lansoprazole in NaCl on days 8-14. Blood samples were collected on days 1, 7, 8 and 14. Fasting basal acid output and pentagastrin-stimulated maximal acid output were determined on days -1, 8, 9 and 15. Thirty-six different subjects received one of four regimen sequences: intravenous lansoprazole in NaCl, intravenous in polyethylene glycol, per orally, or intravenous placebo, each for 5 days. Twenty-four hour intragastric pH was recorded on days 1 and 5. RESULTS: Intravenous and per oral lansoprazole for 7 days produced equivalent basal acid output and maximal acid output suppression. Pharmacokinetics and mean pH values with intravenous lansoprazole in NaCl or polyethylene glycol were equivalent. Both produced mean pH and percentages of time pH above 3, 4, 5 and 6 that were significantly greater than did per orally. CONCLUSIONS: Intravenous lansoprazole inhibits acid secretion as effectively in NaCl as in polyethylene glycol, and its onset of action is faster than per oral lansoprazole.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2004

Generating doughnut-shaped beams with large charge numbers by use of liquid-crystal spiral phase plates.

Liquid-crystal spiral phase plates with cell gaps of 7 and 20 microm have been used to generate doughnut-shaped beams (doughnut beams) with charges of 1 and 4, respectively. Stacking these liquid-crystal spiral phase plates yielded doughnut beams with charge numbers up to 8. High efficiency and flexibility are the advantages of generating doughnut beams by stacking liquid-crystal spiral phase plates. Interference of doughnut beams generated by liquid-crystal spiral phase plates and plane waves has been studied. Fingerlike interference patterns were obtained with a doughnut beam tilted from a Gaussian beam; spiral fanlike patterns were obtained with a doughnut beam and a Gaussian beam collimated coaxially. The experimental results are supported qualitatively by simulation. By rotating a glass slide in the path of the Gaussian beam, one can rotate the fanlike interference pattern in a controlled fashion. With the liquid-crystal display technology that we have developed and report here, these liquid-crystal spiral phase plates should find applications in optical tweezers.

Journal Article↗
PubMed2004

Analysis of strain difference in behavior to Cholecystokinin (CCK) receptor mediated drugs in PVG hooded and Sprague-Dawley rats using elevated plus-maze test apparatus.

This study investigated the behavioral mechanisms underlying the anxiogenic, or anxiolytic mediated effects of CCK(2) receptor mediated agonist (CCK-4) and antagonist drugs (LY225910, LY288513, CR2945) in PVG hooded and Sprague-Dawley (SD) rats using the elevated plus maze test apparatus. In addition, the effects of a CCK(1) antagonist (CR1409) were investigated for its possible mediation in anxiety behavior between PVG hooded and SD rats. PVG hooded rats treated with CCK-4, decreased the time spent in the open arm and increased the time spent in the closed arm and correspondingly showed increase in the number of entries in the open arms while the number of entries in closed arm was insignificant, whereas SD rats decreased the time spent in the closed arm, while other parameters remained insignificant. PVG hooded rats administered with various CCK(2) antagonists (LY225910, LY288513, and CR2945) significantly increased the time spent in the open arm and correspondingly decreased the time spent in the closed arm, while the number of entries in the open or closed arm was insignificant, in contrast, SD rats failed to show any reliable significance. PVG hooded rats administered with the CCK(1) antagonist (CR1409), failed to show any reliable significance, in contrast, SD rats significantly increased the time spent in the open arm. The strain differences observed in this study suggests that CCK plays mainly as a neuromodulator, in which the various CCK(2) antagonists may not affect baseline anxiety state, but instead they modulate heightened states of anxiety through differential effects of CCK(1)/CCK(2) receptors.

Animals↗
PubMed2004

Glucagon-like peptide-1 regulates proliferation and apoptosis via activation of protein kinase B in pancreatic INS-1 beta cells.

AIMS/HYPOTHESIS: The incretin hormone glucagon-like peptide-1 augments islet cell mass in vivo by increasing proliferation and decreasing apoptosis of the beta cells. However, the signalling pathways that mediate these effects are mostly unknown. Using a clonal rat pancreatic beta cell line (INS-1), we examined the role of protein kinase B in mediating beta-cell growth and survival stimulated by glucagon-like peptide-1. METHODS: Immunoblot analysis was used to detect active (phospho-) and total protein kinase B. Proliferation was assessed using (3)H-thymidine incorporation, while apoptosis was quantitated using 4'-6-diamidino-2-phenylindole staining and APO percentage apoptosis assay. Kinase-dead and wild-type protein kinase B was introduced into cells using adenoviral vectors. RESULTS: Glucagon-like peptide-1 rapidly activated protein kinase B in INS-1 cells (by 2.7+/-0.7-fold, p<0.05). This effect was completely abrogated by inhibition, with wortmannin, of the upstream activator of protein kinase B, phosphatidylinositol-3-kinase. Glucagon-like peptide-1 also stimulated INS-1 cell proliferation in a dose-dependent manner (by 1.8+/-0.5-fold at 10(-7) mol/l, p<0.01), and inhibited staurosporine-induced apoptosis (by 69+/-12%, p<0.05). Both of these effects were also prevented by wortmannin treatment. Ablation of protein kinase B by adenovirus-mediated overexpression of the kinase-dead form of protein kinase Balpha prevented protein kinase B phosphorylation and completely abrogated both cellular proliferation ( p<0.05) and protection from drug-induced cellular death ( p<0.01) induced by glucagon-like peptide-1. CONCLUSIONS/INTERPRETATION: These results identify protein kinase B as an essential mediator linking the glucagon-like peptide-1 signal to the intracellular machinery that modulates beta-cell growth and survival.

Animals↗
PubMed2004

Distinct regions of periaqueductal gray (PAG) are involved in freezing behavior in hooded PVG rats on the cat-freezing test apparatus.

The periaqueductal gray (PAG) is considered to be an exit relay for defensive responses. Studies have shown that the ventrolateral periaqueductal gray (vlPAG) plays a role in the expression of freezing behavior whereas dorsolateral periaqueductal gray (dlPAG) is involved on both freezing and active forms of defensive behaviors. To further elucidate this theory, lesioned vlPAG and dlPAG rats were exposed to a cat in the cat-freezing test apparatus. Subsequently, a 7-day repeated exposure to a cat was done on the vlPAG and dlPAG lesioned rats. Results showed that the vlPAG lesioned rats demonstrated significant decrease in freezing behavior and corresponding increase in locomotor activity, while the dlPAG lesioned rats failed to show any significance. Subsequent repeated exposure of the vlPAG lesioned rats to a cat for 7 days showed a gradual decrease in freezing behavior with significance shown at days 5, 6 and 7 while the dlPAG lesioned rats failed to show any changes. These results suggest that vlPAG regulates freezing behavior in hooded PVG rats.

Animals↗
PubMed2004

The relationship between solitary pulmonary nodules and bronchi: multi-slice CT-pathological correlation.

AIM: To investigate the relationship between solitary pulmonary nodules (SPN) and bronchi and its value in predicting the nature of the SPN. MATERIALS AND METHODS: We performed volumetric targeted scans of 0.5 mm collimation with multi-slice computed tomography (MSCT), reconstructing multiplanar reconstructions (MPR), curved multiplanar reconstructions (CMPR) and surface-shaded display (SSD) images of bronchi in 78 consecutive patients with SPN (53 malignant and 25 benign) and correlated the findings with those of macroscopic and microscopic specimens. RESULTS: With this CT protocol, the third to seventh-order bronchi were shown continuously and very clearly in all patients. CT findings were consistent with those of specimens. CT demonstrated the relationship between the SPN and bronchi in 46 (86.8%) malignant and 18 (75.0%) benign nodules. Five types of tumour-bronchus relationships were identified with MSCT. Type I: the bronchus was obstructed abruptly by the SPN; type II: the bronchus penetrated into the SPN with tapered narrowing and interruption; type III: the bronchial lumen shown within the SPN was patent and intact; type IV: the bronchus ran around the periphery of the SPN with intact lumen; type V: the bronchus was displaced, compressed and narrowed by the SPN. Malignant nodules were most commonly of type I (58.5%), secondly of type IV (26.4%) and rarely of type V (1.9%). Benign nodules were most often of type V (36.0%), followed by type III (20.0%), type I (16.0%), and there were no type II. Types I, II and IV were more common in malignant nodules, whereas type V was seen more frequently seen in benign nodules (p<0.05). There was no statistically significant difference between the two groups regarding type III. CONCLUSION: Ultra-thin section with MSCT and MPR, CMPR and SSD reconstruction can improve the demonstration of the patterns of tumour-bronchus relationships, which can reflect the pathological changes of the nodules to some extent and help differentiate malignant from benign tumours.

Aged↗
PubMed2004

Injection of okadaic acid into the meynert nucleus basalis of rat brain induces decreased acetylcholine level and spatial memory deficit.

Abnormal hyperphosphorylation of tau and cholinergic deficit occur in the early stage of Alzheimer's disease (AD) and relate to the dementia symptom. Hyperphosphorylation of tau, neurofilament (NF) and other proteins in AD brain appears to be caused by a down-regulation of protein phosphatase 2A (PP2A), but the mechanism leading to cholinergic deficit is still unknown. In this study, we selectively inhibited PP2A by injection of okadaic acid (OA) into the Meynert nucleus basalis of rats. We found that injection of OA induced hyperphosphorylation of tau and NF and decreased acetylcholine (ACh) level in the nucleus basalis of Meynert. These alterations were accompanied by spatial memory deficit in OA-injected rats. We also demonstrated that the OA-induced ACh reduction may be due to a failure of intraneuronal transport of choline acetyltransferase (ChAT) from cell body to the neuronal terminals rather than an alteration of activity of ChAT or acetylcholinesterase. This study suggests that a down-regulation of PP2A may underlie both abnormal hyperphosphorylation of cytoskeletal proteins leading to neurofibrillary degeneration and cholinergic deficiency in AD.

Acetylcholine↗
PubMed2004

Study of renal function matching between Banna Minipig Inbred line and human.

Pigs have been thought to be ideal candidates for xenotransplant donors. However besides the immunological barrier, physiological and pharmacokinetic comparabilities of kidney function between donor animals and humans are important factors for successful xenotransplantation. As a unique large inbred animal, Banna Minipig Inbred (BMI) has been reported to be a potential large animal suitable for xenotransplantation. However, its physical and pharmacokinetic compatibilities with humans have not been documented. The purpose of this investigation was to measure renal routine function, glomerular filtration rate (GFR), renal blood flow (ERPF), and drug metabolism to evaluate comparability to humans. The results suggested that the renal function of BMI was similar to that of humans to eliminate nonprotein nitrogenous end products of metabolism. Pharmacokinetics of p-aminohippurate (PAH) and inulin--the most widely used methods to assess ERPF and GFR--showed that BMI showed lower values than humans for GFR, but similar function to humans in ERPF. The pharmacokinetics of cefazolin; a widely used model drug to study kidney drug metabolizing capacity, showed greater overall renal drug elimination of BMI than of humans. These results suggested that BMI did show comparable data to human renal function.

Adult↗
PubMed2004

RAIDD aggregation facilitates apoptotic death of PC12 cells and sympathetic neurons.

In human cell lines, the caspase 2 adaptor RAIDD interacts selectively with caspase 2 through its caspase recruitment domain (CARD) and leads to caspase 2-dependent death. Whether RAIDD induces such effects in neuronal cells is unknown. We have previously shown that caspase 2 is essential for apoptosis of trophic factor-deprived PC12 cells and rat sympathetic neurons. We report here that rat RAIDD, cloned from PC12 cells, interacts with rat caspase 2 CARD. RAIDD overexpression induced caspase 2 CARD- and caspase 9-dependent apoptosis of PC12 cells and sympathetic neurons. Apoptosis correlated with the formation of discrete perinuclear aggregates. Both death and aggregates required the expression of full-length RAIDD. Such aggregates may enable more effective activation of caspase 2 through close proximity. Following trophic deprivation, RAIDD overexpression increased death and aggregate formation. Therefore, RAIDD aggregation is important for its death-promoting effects and may play a role in trophic factor withdrawal-induced neuronal apoptosis.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Genetic relationship between olfactory response and fitness in Cotesia glomerata (L.).

The flight response of the parasitic wasp Cotesia glomerata (L.) to semiochemicals from a plant-host complex is subject to genetic variation. The significance of additive genetic variance for the odour-guided behaviour has been demonstrated by bidirectional selection. In order to understand the potential and constraints for phenotypic evolution in olfactory response under the pressure of natural selection, this study was to investigate genetic covariation between the odour-guided behaviour and life-history traits and its genetic correlation with the efficiency of parasitism. A paternal half-sib analysis revealed that there was no significant genetic correlation between this behavioural character and any of three life-history traits examined (the development time of immature stages, the body size of female wasps, the number of female wasps per brood). Comparisons between the selected high and low olfactory-response strains showed the lack of correlated responses in these life-history traits to bidirectional selection on the odour-guided behaviour. On the other hand, genotypic differences in the ability of olfactory response significantly affected the efficiency of parasitism. In comparison with the low olfactory-response strain, female wasps from the high olfactory-response strain were able to parasitize more host larvae in a wider area of habitats. This study provides the first evidence of links between olfactory response and population success in parasitoids from a genetic perspective.

Animals↗