| 1. |
- Xu, Hong-Tao, et al.
(författare)
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Effects of fucosylated milk of goat and mouse on Helicobacter pylori binding to Lewis b antigen
- 2004
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Ingår i: World Journal of Gastroenterology. - Beijing : WJG Press. - 1007-9327 .- 2219-2840. ; 10:14, s. 2063-2066
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Tidskriftsartikel (refereegranskat)abstract
- Aim:To evaluate the effects of animal milk containing fucosylated antigens on Helicobacter pylori (H pylon) binding to Lewis b antigen. Methods:A mammary gland expression vector containing human α1-3/4-fucosyltransferase cDNA sequences was constructed. Transient expression of human(α1-3/4-fucosyltransferase cDNA in goat mammary cell and establishment of transgenic mice were performed. The adhesion inhibitory properties of milk samples were analyzed by using Hpylori. Results: Goat milk samples were found to inhibit bacterial binding to Lewis b antigen. The highest inhibition was observed 42 h after injection of the plasmid. The binding activity of Hpylori to Lewis b antigen reduced mostly, by 83%, however milk samples from transgenic mice did not inhibit Hpylori binding to Lewis b antigen. Conclusion: The use of “humanized“ animal milk produced by the transgenic introduction of fucosylated antigen can perhaps provide an alternative therapy and preventive measure for Hpylori infection.
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| 2. |
- Yu, Miao, et al.
(författare)
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SERS study of single-walled carbon nanotubes on silver films deposited on different substrates
- 2003
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Ingår i: Chemical Journal of Chinese Universities / Gao Deng Xue Xiao Hua Xue Xue Bao. - : Chinese Electronic Periodical Services. - 0251-0790. ; 24:6, s. 1285-1288
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Tidskriftsartikel (refereegranskat)abstract
- Surface-enhanced Raman scattering of single-walled carbon nanotubes (SWNTs) on silver films deposited on various substrates, including sapphire, quartz and glass, has been studied systematically. The characteristic features of G-band and D-band have been analyzed and compared with arc discharged and laser ablation samples. D-band is much more sensitive than G-band. The position and the intensity of the G-band in SERS spectra depend on substrates. The peak shift and absolute intensity of G-band on sapphire is obviously larger than that on glass. The contribution of high frequency vibrations to the D-band is also deendent on substrates. Compared to the SWNTs samples with a high semiconducting tube concentration, the sample with high metallic tube concentration has a stronger interaction with silver films.
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| 3. |
- Dozmorov, Mikhail, 1973, et al.
(författare)
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Slowly developing depression of N-methyl-D-aspartate receptor mediated responses in young rat hippocampi.
- 2004
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Ingår i: BMC neuroscience. - : Springer Science and Business Media LLC. - 1471-2202. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Activation of N-methyl-D-aspartate (NMDA) type glutamate receptors is essential in triggering various forms of synaptic plasticity. A critical issue is to what extent such plasticity involves persistent changes of glutamate receptor subtypes and many prior studies have suggested a main role for alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors in mediating the effect. Our previous work in hippocampal slices revealed that, under pharmacological unblocking of NMDA receptors, both AMPA and NMDA receptor mediated responses undergo a slowly developing depression. In the present study we have further addressed this phenomenon, focusing on the contribution via NMDA receptors. Pharmacologically isolated NMDA receptor mediated excitatory postsynaptic potentials (EPSPs) were recorded for two independent synaptic pathways in CA1 area using perfusion with low Mg2+ (0.1 mM) to unblock NMDA receptors. RESULTS: Following unblocking of NMDA receptors, there was a gradual decline of NMDA receptor mediated EPSPs for 2-3 hours towards a stable level of ca. 60-70 % of the maximal size. If such an experimental session was repeated twice in the same pathway with a period of NMDA receptor blockade in between, the depression attained in the first session was still evident in the second one and no further decay occurred. The persistency of the depression was also validated by comparison between pathways. It was found that the responses of a control pathway, unstimulated in the first session of receptor unblocking, behaved as novel responses when tested in association with the depressed pathway under the second session. In similar experiments, but with AP5 present during the first session, there was no subsequent difference between NMDA EPSPs. CONCLUSIONS: Our findings show that merely evoking NMDA receptor mediated responses results in a depression which is input specific, induced via NMDA receptor activation, and is maintained for several hours through periods of receptor blockade. The similarity to key features of long-term depression and long-term potentiation suggests a possible relation to these phenomena. Additionally, a short term potentiation and decay (<5 min) were observed during sudden start of NMDA receptor activation supporting the idea that NMDA receptor mediated responses are highly plastic.
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| 4. |
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| 5. |
- Li, Hui
(författare)
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Dynamic Fetal and Placental Circulatory Changes during Uterine Contractions
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The best mode of delivery for fetuses with intrauterine growth restriction (IUGR) and umbilical artery (UA) blood flow changes is not well elucidated. Uterine artery, fetal UA, middle cerebral artery (MCA), and venous blood flow changes during uterine contractions during an oxytocin challenge test (OCT) have not been observed systemically. AIMS: To evaluate outcome in IUGR with UA blood flow changes planned for vaginal delivery after a negative OCT, and to investigate uterine artery, fetal UA, MCA, and venous blood flow during OCT with Doppler ultrasound. RESULTS: 1. A positive OCT occurred twice as often in IUGR with abnormal UA blood flow as in IUGR with normal flow. In OCT negative cases allowed a trial of labor, the vaginal delivery rate was not different between the two flow groups. 2. Doppler velocimetry of blood flow velocity waveforms (FVWs) during uterine quiescence, contractions and relaxations in the uterine arteries identified 11 different waveform shapes when recordings were systemically classified with regard to the mean flow velocity over the pulse cycle. 3. No different uterine artery blood flow changes during the OCT were found in cases with or without operative delivery for fetal distress (ODFD) or birth asphyxia. 4. The UA vascular flow resistance was significantly higher in OCT positive cases compared with negative cases during uterine contractions and relaxations, but not during basal measurements; No different UA blood flow changes during the OCT were found in cases with or without ODFD or birth asphyxia. 5. The vascular flow resistance in fetal MCA decreased during uterine contractions and relaxations compared with basal measurements both in OCT positive and negative cases, but OCT positive cases showed a more pronounced decrease. 6. Increased blood flow velocities and decreased impedance to flow occurred in fetal cerebral veins parallel to a decrease of vascular flow resistance in the fetal MCA during uterine contractions. CONCLUSIONS: OCT was just as good in the abnormal flow group as in the normal flow group to select suitable candidates for a trial of vaginal delivery. The proposed qualitative classification system may accomplish to cover a complete spectrum of different uterine artery FVWs, but uterine artery blood FVWs during the OCT seems have a limited clinical value in predicting pregnancy outcome. A vascular pathophysiological mechanism operating in OCT positive cases was disclosed only during the OCT, but an ‘OCT Doppler velocimetry?of UA blood flow seems to have a limited predictive value on neonatal outcome. A redistribution of the fetal circulation with a ‘brain-sparing?flow is a physiological phenomenon occurring during acute hypoxemia provoked by uterine contractions.
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| 6. |
- Li, Hui, et al.
(författare)
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Prospect for vaginal delivery of growth restricted fetuses with abnormal umbilical artery blood flow.
- 2003
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 1600-0412 .- 0001-6349. ; 82:9, s. 828-833
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Tidskriftsartikel (refereegranskat)abstract
- Background. The best mode of delivery in cases of intrauterine growth restriction (IUGR) with umbilical artery blood flow changes is not well elucidated. Objective. To evaluate outcome in IUGR with umbilical artery blood flow changes planned for vaginal delivery after a negative oxytocin challenge test (OCT). Methods. In 84 term singleton pregnancies with suspected IUGR and no unanimous indication for abdominal delivery, Doppler velocimetry and OCT were performed. Positive OCT cases were delivered by cesarean section, negative OCT cases planned for vaginal delivery. Results. Umbilical artery Doppler velocimetry was normal in 51 cases (normal group) and abnormal in 33 cases (increased pulsatility index with maintained forward diastolic flow). Gestational age at delivery was shorter (p = 0.008), positive OCT more common (33% vs. 16%; p = 0.06), and vaginal delivery less common (40% vs. 63%; p = 0.04) in the abnormal blood flow group compared with the normal flow group. When in labor, 68% in the abnormal flow group and 76% in the normal flow group delivered vaginally (p = 0.6). One baby had a lethal malformation and another suffered meconium aspiration and pneumothorax, but was discharged home healthy. Conclusions. The vaginal delivery rate was significantly lower in the abnormal flow group compared with the normal flow group, but in cases finally destined for a trial of labor the vaginal delivery rates were similar. There was no indication that any fetus was exposed to detrimental hypoxia or distress.
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| 7. |
- Li, Hui-xiang, et al.
(författare)
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[Expressions of thymidine phosphorylase, thymidylate synthase and dihydropyrimidine dehydrogenase in breast cancer and their correlations with prognosis]
- 2004
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Ingår i: Zhonghua zhong liu za zhi [Chinese journal of oncology]. - Beijing, China : Zhongguo Yixue Kexueyuan / Cancer Hospital, Chinese Academy of Medical Sciences. - 0253-3766. ; 26:11, s. 669-672
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To study the expression of thymidine phosphorylase (TP), thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) mRNA in breast cancer and its correlation with prognosis.Methods: Expression levels of TP, TS and DPD mRNA in 86 micro-selected breast cancer tissues and 9 normal breast tissues were detected by real-time quantitative PCR.Results: The median expression levels of TP, TS and DPD mRNA in tumor tissue and in normal tissues were 16.54, 0.38, 2.47 and 11.75, 0.25, 8.33, respectively, there were no significant differences (P >0.05). The expression levels of TP, TS and DPD mRNA showed no association with tumor size, lymph node metastasis, pathological grade and clinical stage, except that of DPD showed a negative association with patients' ages. There was no significant difference in disease-free survival or overall survival between the patients with high and low TP or DPD mRNA levels. Disease-free survival tends to be better in the patients with low TS mRNA level than those with high TS mRNA, but the difference was not significant (P=0.069), while the overall survival showed a statistically difference (59.00 month and 70.30 month) (P=0.0496).Conclusion: The expression level of TS mRNA may serve as a prognostic marker for breast cancer patients.
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| 8. |
- Li, Y, et al.
(författare)
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Robustness of Air Distribution in Plenum-Based Ductless Ventilation Systems
- 2004
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Ingår i: The International Journal of Ventilation. - 1473-3315 .- 2044-4044. ; 3:2, s. 105-118
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This paper introduces a concept of robustness of an air distribution method, which is defined as being capable of meeting the ventilation requirements during varying operational conditions. The robustness performance may be particularly important when the system allows individual control of the supply air parameters. As a preliminary example, plenum-based (ductless) air distribution methods are studied using computational fluid dynamics. Among the four basic air distribution methods in plenum-based systems, it is found that the floor supply and ceiling return system does not always produce the conventional displacement ventilation system performance when the heat sources are not concentrated. The ceiling supply with ceiling return produces the best robustness performance over a wide range of supply velocities.
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| 9. |
- Zhang, Shu-min, et al.
(författare)
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Dynamic changes in hepatitis C virus genotypes and sequence patterns in plasma donors exposed to reinfection
- 2001
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Ingår i: Journal of Medical Virology. - 1096-9071. ; 63:3, s. 228-236
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Tidskriftsartikel (refereegranskat)abstract
- Sequential serum samples from four plasma donors (designated A, B, C, and D) at a Chinese blood bank with hepatitis C transmission problems were studied from 1994 to 1997. The samples were examined for antibodies to HCV, for HCV viremia by PCR and HCV genotyping. Co- and superinfections were studied by direct sequencing of the 5'-NCR, core, and HVR-1 regions, using low and high genotype-specific primers targeting the HVR-1, and by cloning of selected samples. Genotype changes occurred in all four donors: A (1b-2a-1b), B (1b-2a-2a/1b-1b), C (1b-2a), and D (1b/2a-1b). Donor D was married to donor B. The 1b isolates of donor A could not be sequenced in the HVR-1 due to low-level viremia. Two early 1b isolates from donors B and C showed high HVR-1 similarity. The later 1b isolates from B had changed significantly but were identical to the isolate from donor D. Spouses B and D also shared genotype 2a strains. The 2a isolates from donors A, B/D, and C differed by 8-10 nucleotides in the HVR-1. The frequent changes in genotype and the appearance of homologous isolates from different subjects indicate transmission at the blood bank. These four donors, all identified shortly after infection, developed very few mutations in the HVR-1 and few quasispecies during a period of 6-18 months. Highly specific primers proved to be superior to cloning for identification of minor virus populations. The results indicate nosocomial transmission of more than one strain at the blood bank studied.
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