| 1. |
- Li, Jie, et al.
(författare)
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Heat stress alters G-protein coupled receptor-mediated function and endothelium-dependent relaxation in rat mesenteric artery
- 2008
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Ingår i: European Journal of Pharmacology. - : Elsevier BV. - 1879-0712 .- 0014-2999. ; 588:2-3, s. 280-285
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Tidskriftsartikel (refereegranskat)abstract
- Heat stress has been demonstrated to have strong cardiovascular effects. However, the underlying mechanism-mediated cardiovascular effects are still not fully understood. The present study was designed to examine if heat stress alters vascular G-protein coupled receptor-mediated vasomotion and endothelium function in rat mesenteric artery. Rats were divided into two groups, heat stress rats and control. The G-protein coupled receptors of endothelin type B (ETB) receptor-, endothelin type A (ETA) receptor-, 5-hydroxytryptamine (5-HT) receptor-, calcitonin gene-related peptide (CGRP) receptor-, alpha-adrenoceptor-mediated vosoactivity and endothelium-dependent relaxation on rat mesenteric artery ring segments were monitored by a myograph system. The plasma level of CGRP was determined by radioimmunological assay. Compared with control arterial segments, the contractile response curves of sarafotoxin 6c, a selective ETB receptor agonist and 5-HT in the arterial segments from heat stress rats were shifted towards left. An increased maximum contraction (E-max) induced by sarafotoxin 6c, but not 5-HT, was seen in the arterial segments from heat stress rats. CGRP-incluced relaxation in endothelium-denuded arterial segments from heat stress rats was enhanced. The relaxation in endothelium-intact arterial segments induced by acetylcholine was significantly decreased in heat stress rats. In addition, the plasma concentration of CGRP was increased in heat stress rats. The endothelium-dependent relaxation was characterized and shown there was a decrease in nitric oxide and endothelium-derived hyperpolarising factor-mediated relaxation in the arterial segments from heat stress rats. In conclusion, heat stress induces an enhanced vascular endothelin ETB-, 5-HT-receptors-mediated contraction, an enhanced CGRP-receptor-induced relaxation and damage to endothelium-dependent relaxation.
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| 2. |
- Tian, Chao, et al.
(författare)
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Overexpression of connective tissue growth factor WISP-1 in Chinese primary rectal cancer patients
- 2007
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Ingår i: World Journal of Gastroenterology. - 1007-9327 .- 2219-2840. ; 13:28, s. 3878-3882
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To clarify the expression change of Wnt-induced secreted protein-1 (WISP-1) in human rectal cancer and to determine whether it is correlated with invasion and metastasis of human rectal cancer. Methods: Eighty-six paired samples of rectal cancer and surgically resected distant normal rectal tissue were collected and allocated into cancer group and control group respectively. WISP-1 mRNA was detected by relative quantitative real-time RT-PCR and WISP-1 protein was examined by immunohistochemical staining. Results: WISP-1 gene overexpression was found in 65% (56/86) primary rectal cancers, 2-30 times that of the level in normal matched rectal tissues (P = 0.001). The mRNA expression level was correlated with Duke's staging, histological differentiation grade and lymph node status. The WISP-1 protein expression was in accordance with mRNA expression level. The positive degree of immunohistochemical staining in the cancer group (1.40 ± 0.35) was different from that in control group (1.04 ± 0.08, P < 0.001). Moreover, in cancer group the positive staining degree in high-level mRNA cancers (1.46 ± 0.37, n = 56) was higher than that in low-level mRNA (1.28 ± 0.28, n = 30, P = 0.018). Conclusion: Aberrant levels of WISP-1 expression may play a role in rectal tumorigenesis. WISP-1 may be used as a specific clinical diagnosis and prognosis marker in rectal cancer. © 2007 WJG. All rights reserved.
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| 3. |
- Wang, Yong, et al.
(författare)
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mRNA expression of minichromosome maintenance 2 in colonic adenoma and adenocarcinoma
- 2009
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Ingår i: EUROPEAN JOURNAL OF CANCER PREVENTION. - 0959-8278. ; 18:1, s. 40-45
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Tidskriftsartikel (refereegranskat)abstract
- As proliferation is essential for Progression from normal cells to tumor, certain markers specific to proliferating cells may permit detection of premalignant lesions. Here, we aimed to evaluate the possible value of a proliferation marker, minichromosome maintenance 2 (MCM2), in the early diagnosis of colorectal cancer, by analyzing the difference in MCM2 expression among normal mucosa, adenoma, and adenocarcinoma, and investigating the relationship of MCM2 expression in adenomas with clinicopathologic variables. Using immunohistochemistry and real-time reverse transcription-PCR, we observed that the expression of MCM2 protein was present on basal third to half of colonic crypts in normal mucosa, whereas throughout the epithelium in adenomas and adenocarcinomas, the expression of MCM2 mRNA in adenocarcinomas was significantly higher than in adenomas (P=0.001), whereas the difference between adenoma and normal mucosa was not significant (P=0.184); we also found that the expression of MCM2 mRNA tended to be increased in the adenomas with high-grade dysplasia, or in older patients, respectively, compared with those with low-grade dysplasia, and younger patients. These results suggested the potential value of MCM2 in early diagnosis of colorectal cancer.
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| 4. |
- Zhang, Zhi-Yong, et al.
(författare)
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Nup88 expression in normal mucosa, adenoma, primary adenocarcinoma and lymph node metastasis in the colorectum
- 2007
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Ingår i: Tumor Biology. - : Springer Science and Business Media LLC. - 1010-4283 .- 1423-0380. ; 28:2, s. 93-99
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: It was the aim of this study to investigate Nup88 expression in normal colorectal mucosa, adenoma, adenocarcinoma and lymph node metastasis, as well as the relationship between Nup88 expression and clinicopathological features. Methods: Nup88 expression was examined by immunohistochemistry in 84 normal mucosa samples, 32 adenomas, 181 primary adenocarcinomas, and 18 lymph node metastases from colorectal tumour patients. Results: Nup88 expression was observed in normal epithelial and tumour cells. The frequency of strong Nup88 expression was increased from normal mucosa or adenoma to primary tumour and lymph node metastasis (p < 0.0001). There was no significant difference in the expression between normal mucosa and adenoma (p = 0.41). The frequency of strong Nup88 expression was higher in ulcerated tumours (40%) than in polypoid/large fungating tumours (23%, p = 0.048). The frequency of strong Nup88 expression was significantly different among tumours with good (21%), moderate (42%) and poor differentiation (48%, p = 0.01). Nup88 expression was not related to the patients' gender, age, tumour location, size, histological type, invasive depth, lymph node status and Dukes stage (p > 0.05). Conclusion: Our results suggest that Nup88 may play a role during the development, aggressiveness and differentiation of colorectal tumours. Copyright © 2007 S. Karger AG.
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| 5. |
- Zhao, Guang-Jiu, et al.
(författare)
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Photoinduced intramolecular charge transfer and S-2 fluorescence in thiophene-pi-conjugated donor-acceptor systems : Experimental and TDDFT studies
- 2008
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 14:23, s. 6935-6947
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Tidskriftsartikel (refereegranskat)abstract
- Experimental and theoretical methods were used to study newly synthesized thiophene-pi-cojugated donor-acceptor compounds, which were found to exhibit efficient intramolecular charge-transfer emission in polar solvents with relatively large Stokes shifts and strong solvatochromism. To gain insight into the solvatochromic behavior of these compounds, the dependence of the spectra on solvent polarity was studied on the basis of Lippert-Mataga models. We found that intramolecular charge transfer in these donor-acceptor systems is significantly dependent on the electron-with-drawing substituents at the thienyl 2-position. The dependence of the absorption and emission spectra of these compounds in methanol on the concentration of trifluoroacetic acid was used to confirm intramolecular charge-tranfer emission. Moreover, the calculated absorption and emission energies, which are in accordance with the experimental values, suggested that fluorescence can be emitted from different geometric confirmations. In addition, a novel S-2 fluorescence phenomenon for some of these compounds was also be observed. The fluorescence excitation spectra were used to confirm the S-2 fluorescence. We demonstrate that S-2 fluorescence can be explained by the calculated energy gap between the S-2 and S-1 states of these molecules. Furthermore, nonlinear optical behavior of the thiophene-pi-conjugated compound with diethylcyanomethylphosphonate substituents was predicted in theory.
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| 6. |
- Bonilha, Vera L, et al.
(författare)
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Semenogelins in the human retina: Differences in distribution and content between AMD and normal donor tissues
- 2008
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Ingår i: Experimental Eye Research. - : Elsevier BV. - 0014-4835. ; 86:1, s. 150-156
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Tidskriftsartikel (refereegranskat)abstract
- The two cellular targets of interest in age-related macular degeneration (AMD) are the photoreceptors and the RPE. However, the mechanisms involved in AMD pathology are not yet fully understood. In the present report, we extend our previous studies on semenogelin proteins (Sgs) in normal human retina and compare these with the distribution in retinas from AMD donor eyes. Semenogelins I (SaI) and II (SaII) are the major structural protein components of semen coagulum, but have been recently found in non-genital tissues as well. Cryo and paraffin sections of human retina were processed for both immunofluorescence and DAB reaction with a specific antibody. The presence of Sal was analyzed in retina and RPE total lysates and SaI was detected by western blot in human retina and RPE. The intensity of immunoreactivity was significantly reduced in the AMD eyes. Sal is expressed in the normal human retina and in the retina of AMD donor eyes, where localization was detected in the photoreceptors and in a few ganglion cells. We find the distribution of Sal in the AMD retinas substantially lower than observed in normal retina. Sal localization to photoreceptors and the RPE suggests a possible function related to the ability of these cells to sequester zinc.
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| 7. |
- Chen, H., et al.
(författare)
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The distribution of grating-coupled field of quantum well infrared photodetector using FDTD method
- 2007
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Ingår i: Infrared Materials, Devices, and Applications. - : SPIE - International Society for Optical Engineering. - 9780819470102 ; , s. 68351E-
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Konferensbidrag (refereegranskat)abstract
- For most commonly used GaAs/AlGaAs n-type quantum well infrared photodetectors (QWIPs), the normal incident absorption is not possible because of the transition rule. The optical grating is required to achieve high absorption quantum efficiencies. When some gratings are patterned on the metal plate, the polarization direction can be changed greatly because of the diffraction effect. Finite difference time domain (FDTD) method has been used to investigate the effect of a reflection metal grating on the couple efficiency previously. However, the authors only take one metal grating and apply periodic boundary condition along the grating direction due to the computation limit. For a real QWIP system, such simulation is crude. In this work we consider a real GaAs/AlGaAs QWIP with a wavelength response around 15um and use FDTD method to investigate the effect of a reflection metal grating on the electric field pattern and the couple efficiency. The simulating results show that the electric field pattern is not periodic for every metal grating in a real QWIP system. We have also studied the influence of the substrate thickness and the grating period on the electric field pattern and the couple efficiency. These results offer a guideline for the design of QWIP.
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| 8. |
- Hua, Dong, et al.
(författare)
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Small interfering RNA-directed targeting of toll-like receptor 4 inhibits human prostate cancer cell invasion, survival, and tumorigenicity
- 2009
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Ingår i: Molecular Immunology. - : Elsevier BV. - 0161-5890 .- 1872-9142. ; 46:15, s. 2876-2884
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Tidskriftsartikel (refereegranskat)abstract
- A major cause of tumor treatment failure is cancer cell metastasis. Toll-like receptor 4 (TLR4)-mediated signaling has been implicated in tumor cell invasion, survival, and metastasis in a variety of cancers. In this study, we investigated the biological roles of TLR4 in prostate metastatic cell invasion and survival, and the potential of gene silencing of TLR4 using small interfering RNA (siRNA) for treatment of cancer. In cultured human prostate cancer cell lines, TLR4 were higher PC3 and DU145 as compared with the poorly metastatic LNCaP indicating that up-regulation of TLR4 was positively correlated with metastasis of tumor cell. In the highly metastatic cancer cell PC3, gene silencing of TLR4 using siRNA significantly inhibited TLR4 mRNA expression and protein level. Knockdown of TLR4 in PC3 cells resulted in a dramatic reduction of tumor cell migration and invasion as indicated by a Matrigel invasion assay. Furthermore, TLR4 siRNA suppressed cell viability and ultimately caused the induction of apoptotic cell death. The effects were associated with abrogating TLR4-mediated signaling to downstream target molecules such as myeloid differentiation factor 88 (MyD88), adaptor-inducing IFN-beta (TRIF), and interferon regulatory factor-1 (IRF-1). In a mouse prostate cancer model, administration with the plasmid construct expressing siRNA for TLR4 obviously inhibited established tumor growth and survival. These studies revealed evidence of a multifaceted signaling network operating downstream of TLR4-mediated tumor cell invasion, proliferation, and survival. Thus, RNA interference-directed targeting of TLR4 may raise the potential of its application for cancer therapy.
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| 9. |
- Lele, Duan, et al.
(författare)
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Carbene-pyridine chelating 2Fe2S hydrogenase model complexes as highly active catalysts for the electrochemical reduction of protons from weak acid (HOAc)
- 2007
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; :13, s. 1277-1283
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Tidskriftsartikel (refereegranskat)abstract
- Two asymmetrically disubstituted diiron complexes (mu-pdt)[Fe(CO)(3)][Fe(CO)(eta(2)-L)] (L = 1-methyl-3-(2-pyridyl)imidazol-2-ylidene (NHCMePy), 2; 1,3-bis(2-picolyl) imidazol-2-ylidene (NHCdiPic), 4) and a mono-substituted diiron complex (mu-pdt)[Fe(CO)(3)][Fe(CO)(2)(NHCdiPic)] (3) were prepared as biomimetic models of the Fe-only hydrogenase active site. X-Ray studies show that the NHCMePy and NHCdiPic ligands in 2 and 4 each coordinate to the single iron atom as NHC-Py chelating ligands in two basal positions and the NHCdiPic ligand of complex 3 lies in an apical position as a monodentate ligand. The large ranges of the highest and the lowest nu(CO) frequencies of 2 and 4 reflect that the relatively uneven electron density on the two iron atoms of the 2Fe2S model complexes 2 and 4 is as that observed for mono-substituted diiron complexes of good donor ligands. The cyclic voltammograms and the electrochemical proton reduction by 2 and 3 were studied in the presence of HOAc to evaluate the effect of asymmetrical substitution of strong donor ligands on the redox properties of the iron atoms and on the electrocatalytic activity for proton reduction.
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| 10. |
- Li, He, et al.
(författare)
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Enhanced G-protein coupled receptors-mediated contraction and reduced endothelium-dependent relaxation in hypertension
- 2007
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Ingår i: European Journal of Pharmacology. - : Elsevier BV. - 1879-0712 .- 0014-2999. ; 557:2-3, s. 186-194
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Tidskriftsartikel (refereegranskat)abstract
- The present study was designed to demonstrate a hypothesis that some G-protein coupled receptors are up-regulated and a dysfunction of endothelium occurs in hypertension. The arteries from hypertensive patients and spontaneously hypertensive rats (SHR) were tested. An in vitro myograph system was used to obtain concentration-contraction curves mediated by endothelin ETA, endothelin ETB, 5-hydroxytryptamine 2A (5HT(2A))-receptors and alpha(1)-adrenoceptors in the arterial segments. In hypertensive patients, the maximum contractions (E-max) induced by endothelin ETB, endothelin ETA and 5-HT receptors were significantly increased with elevated pEC(50) values, while a significantly leftward shift of alpha(1)-adrenoceptor-mediated contraction was seen. Similar results were obtained in SHR. Specific antagonists for 5-HT2A receptors or alpha(1)-adrenoceptors rightward shifted the concentration-contractile curves induced by 5-HT or noradrenalin, while the Emax were not significantly altered, suggesting that the contractions were mediated by 5-HT2A receptors and ocl-adrenoceptors, respectively. Endothelium-dependent maximum relaxation (R-max) in the arterial segments induced by acetylcholine was significantly decreased in both hypertensive patients and SHR. In addition, nitric oxide- and endothelium-derived hyperpolarizing factor-mediated dilatations were decreased significantly and the arterial enclothelial cells were in part lost in SHR. In conclusion, endotheliD ETB, endothelin ETA, 5-HT2A receptor- and alpha-adrenoceptor-mediated contractions were increased in hypertension, while the endotheliurn and its ftinctions were damaged. (c) 2006 Elsevier B.V All rights reserved.
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