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91.
Integrin expression and osteopontin regulation in human fetal osteoblastic cells mediated by substratum surface characteristics 总被引:2,自引:0,他引:2
Integrin-mediated adhesion of anchorage-dependent cells to scaffolds is a critical component of tissue engineering. We investigated integrin expression by the human fetal osteoblastic cell line, hFOB 1.19 (hFOB), as a function of substratum surface wettability. The influence of surface wettability on bone cell phenotype was also examined. Plasma-treated quartz (PTQ) and glass (PTG) (hydrophilic, contact angles of 0 degrees), octadecyltrichlorosilane-treated quartz (STQ) and glass (STG) (hydrophobic, contact angles above about 100 degrees), and tissue culture polystyrene were used for cell culture. hFOB cells cultured on hydrophilic substrata displayed well-developed actin stress fibers relative to cells on hydrophobic substrata. Western blot analysis revealed that hFOB cells cultured on hydrophobic substrata (STQ or STG) express lower levels of alphav and beta3 integrin subunits than do cells on hydrophilic substrata (PTQ or PTG). This effect was more pronounced in cells on STQ than on STG. These variations in integrin expression were lessened by extended culture time. Double- labeled integrin/actin immunofluorescence confirmed Western blot results, that is, cells cultured on PTQ displayed distinct, large plaques of alphav and beta3 subunits and integrin alphavbeta3, as well as their colocalization with actin stress fiber ends, whereas cells on STQ did not display integrin plaques after 24 h and displayed only minimal plaque formation after 3 days. Vinculin, a focal adhesion protein that mediates binding between the integrin and actin cytoskeleton, appeared in Western blots to mimic the variations of alphav and beta3 expression with respect to surface wettability. Interestingly, real-time RT-PCR analysis showed that hFOB cultured on hydrophobic substrata, which have downregulated alphav and beta3 integrin subunits, displayed greater steady state mRNA levels of osteopontin, an extracellular matrix (ECM) protein containing the Arg-Gly-Asp (RGD) integrin recognition sequence, than did cells cultured on hydrophilic substrata. Our results imply that substratum surface wettability regulates integrin-mediated bone cell adhesion and further influences the expression of bone cell-ECM complexes. 相似文献
92.
Yu-Sheng Chang Pao-Hsien Chu Shih-Ming Jung Kun-Eng Lim Jaw-Ji Chu Chuen Hsueh Ying-Shiung Lee 《Cardiovascular pathology》2005,14(2):104-106
Cardiac papillary fibroelastoma (CPF) is the second most common benign neoplasm of the heart. This study describes the case of an 81-year-old man who was admitted to the hospital for severe vertigo and in whom a tumor at the right ventricular outflow tract (RVOT) was identified incidentally during echocardiography. The CPF was excised smoothly following the confirmation of its position by computed tomography. The comprehensive pathologic findings of CPF were reviewed. Detailed immunohistochemical analyses of CD34 and factor VIII-related antigen were performed on the covering endocardial cells. The unique chondroid metaplasia of fibrous tissue in this CPF has never been reported. This work is the first to present an unusual CPF at the RVOT with reactive process of fibrous connective tissue. 相似文献
93.
In-Suk Kim Eun Sil Park Jae Young Lim Chang-Seok Ki Hyun Sook Chi 《Journal of Korean medical science》2008,23(6):1105-1108
Although acquired mutations in the GATA1 gene have been reported for Down syndrome-related acute megakaryoblastic leukemia (DS-AMKL) in Caucasians, this is the first report of a Korean Down syndrome patient with AMKL carrying a novel mutation of the GATA1 gene. A 3-yr-old Korean girl with Down syndrome was admitted to our hospital complaining of pallor and fever. The findings of a peripheral blood smear and bone marrow study were compatible with the presence of AMKL. A chromosome study showed 48,XX,-7,+21c,+21,+r[3]/47,XX,+21c[17]. Following GATA1 gene mutation analysis, a novel mutation, c.145dupG (p.Ala49GlyfsX18), was identified in the N-terminal activation domain of the GATA1 gene. This mutation caused a premature termination at codon 67 and expression of an abnormal GATA-1 protein with a defective N-terminal activation domain, and the absence of full-length GATA-1 protein. This case demonstrates that a leukemogenic mechanism for DS-AMKL is contributed by a unique collaboration between overexpressed genes from trisomy 21 and an acquired GATA1 mutation previously seen in Caucasians and now in a Korean patient. 相似文献
94.
Comparative Analysis of Two Commercial Phenotypic Assays for Drug Susceptibility Testing of Human Immunodeficiency Virus Type 1 总被引:2,自引:0,他引:2
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95.
Melanocortin is the downstream mediator of leptin signaling and absence of leptin signaling in ob/ob and db/db mice revealed the enhancement of bone formation through the central regulation. While alpha-melanocyte-stimulating hormone (alphaMSH) inhibits the secretion of interleukin-1alpha and tumor necrosis factor-alpha from the inflammatory cells, alphaMSH can also enhance clonal expansion of pro B cells linked to stimulation of osteoclastogenesis. Therefore, we tested the effect of melanocortin on bones. alphaMSH analogues [(6)His]alphaMSH-ND and [(6)Asn]alphaMSH-ND were synthesized and the radio-ligand receptor binding- and cyclic AMP generating activity were analyzed in China Hamster Ovary cell line over- expressing melanocortin receptors. The EC(50) of [(6)His]alphaMSH-ND measured from melanocortin-1, 3, 4 and 5 receptors were 0.008 +/- 0.0045, 1.523 +/- 0.707, 0.780 +/- 0.405, and 250.320 +/- 42.234 nM, respectively, and the EC(50) of [(6)Asn]alphaMSH-ND were 16.8 +/- 6.94, 271.8 +/- 21.95, 8.0 +/- 1.21, and 1132.5 +/- 635.46 nM, respectively. Four weeks after the subcutaneous injection of the analogues, the body weights in the [(6)His]alphaMSH-ND and the [(6)Asn]alphaMSH-ND treated groups (346.0 +/- 20.63 g vs. 350.0 +/- 13.57 g) were lower than that of the vehicle treated group (375.8 +/- 17.31 g, p < 0.05). There was no difference in the total femoral BMD measured by dual x-ray absorptiometry among the three groups. Among the three groups, there were no differences in the total numbers of crystal violet positive- or alkaline phosphatase positive colonies, in the expression of Receptor Activator of Nuclear Factor Kappa-B ligand on the tibia and the total number of multinucleated osteoclast-like cells differentiated from primary cultured bone marrow cells. From the above results, no evidence of bone gain or loss was found after treatment of the alphaMSH analogues peripherally. 相似文献
96.
The value of immunohistochemical detection of P-glycoprotein in breast cancer before and after induction chemotherapy. 总被引:5,自引:0,他引:5
E H Koh H C Chung K B Lee H Y Lim J H Kim J K Roh J S Min K S Lee B S Kim 《Yonsei medical journal》1992,33(2):137-142
We have studied the patterns of P-glycoprotein expression before and after 3 cycles of induction chemotherapy (5-fluorouracil, adriamycin and cyclophosphamide) using immunohistochemically stained paraffin-embedded specimen of 28 patients with locally advanced breast cancer. The frequency of P-glycoprotein expression in untreated breast cancer turned out to be very low: only one out of 28 untreated, biopsy specimen at the time of diagnosis was positive. The frequency of P-glycoprotein expression was markedly increased from 9.1% before chemotherapy to 63.6% after induction chemotherapy (p = 0.006). After 3 cycles of induction chemotherapy, 25 patients had obtained clinical response to chemotherapy (4, CR; 21, PR). Eleven out of 25 tumors (44%) showing clinical response and all three tumors (100%) with minimal response have expressed P-glycoprotein. One out of 6 patients (16.7%) with microscopic residual tumor seen in mastectomy specimen expressed P-glycoprotein, whereas 13 of 22 patients (59.1%) with gross residual tumor showed the presence of P-glycoprotein (p = 0.08). The frequency of intrinsic P-glycoprotein expression in untreated breast cancer was quite low, but approximately half of the patients do acquire P-glycoprotein expression during the cycles of induction chemotherapy. Therefore, the results suggest that the immunohistochemical detection of P-glycoprotein on residual tumor cells after induction chemotherapy can predict acquired drug resistance in breast cancer. 相似文献
97.
Evaluation of Etest MBL for detection of blaIMP-1 and blaVIM-2 allele-positive clinical isolates of Pseudomonas spp. and Acinetobacter spp 总被引:10,自引:0,他引:10
Lee K Yong D Yum JH Lim YS Bolmström A Qwärnström A Karlsson A Chong Y 《Journal of clinical microbiology》2005,43(2):942-944
The Etest MBL (AB BIODISK, Solna, Sweden) correctly differentiated all 57 isolates of Acinetobacter spp. and Pseudomonas aeruginosa with the bla(IMP-1) allele and 135 of 137 (98.5%) Acinetobacter spp. and Pseudomonas spp. isolates with the bla(VIM-2) allele. The Etest MBL was reliable for detecting the IMP-1- and VIM-2-producing Pseudomonas and Acinetobacter isolates. 相似文献
98.
S. Hering D. J. Beech T. B. Bolton S. P. Lim 《Pflügers Archiv : European journal of physiology》1988,411(5):590-592
The actions of nifedipine or BAY K 8644 were studied on barium currents recorded from single, collagenase- and elastase-dispersed, smooth muscle cells from the rabbit ear artery using the whole-cell configuration of the patch-clamp technique. Nifedipine (3M) caused a reduction in the barium current (IBa) evoked by steps to potentials positive of-10mV. This was characterized by a pronounced initial block, an increase in the rate of current decay during the voltage-clamp step, but by no increase in block if pulses were repeated every 600ms. Rapid extracellular application of nifedipine (1M) during the sustained current component (using a new concentration-jump technique) was found to have no effect on IBa over 4s at +20mV, but after returning to the holding potential (-60mV) for 10s, sustained IBa was subsequently abolished. BAY K 8644 (1M) increased IBa at all potentials, and on rapid application during the sustained current component markedly potentiated IBa. The results suggest that nifedipine binds with high affinity to the closed, available state of the Ca++ channels but they do not suggest binding to the open or inactivated states. The effect of BAY K 8644 is consistent with high affinity binding to the open or inactivated and to the closed, available states. 相似文献
99.
100.