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61.
Syk is a 72-kDa protein-tyrosine kinase that regulates signaling through multiple cell surface receptors including those for antigens, immunoglobulins and proteins of the extracellular matrix. As part of its function, Syk binds a variety of downstream effectors through interactions that are often mediated by motifs that recognize phosphotyrosines. In a search for novel Syk-interacting proteins by yeast two-hybrid analysis, we identified tensin2 as a Syk-binding protein. Syk interacts with a fragment of tensin2 located near the C-terminus that contains SH2 and PTB domains. In epithelial cells, tensin2 localizes both to focal adhesions and to large cytoplasmic puncta. It is within these punctuate structures that Syk and tensin2 are co-localized. The clustering of Syk within these structures leads to its phosphorylation on tyrosine.  相似文献   
62.
Background: Studies investigating the association between genetic polymorphism of glutathione S-transferase T1 (GSTT1) and risk of colorectal cancer have reported conflicting results. In order to clarify the effect of GSTT1 polymorphism on the risk of developing colorectal cancer, we carried out a meta-analysis using published data to obtain more precise estimates of risk. Methods: Electronic searches of PubMed and EMBASE were conducted to select studies for this meta-analysis. Papers were included if they were observational studies investigating the association between GSTT1 polymorphism and colorectal cancer risk. The principal outcome measure was the odds ratio (OR) with 95% confidence interval (CI) for the risk of colorectal cancer associated with GSTT1 null genotype. Results: We identified 30 eligible studies, which included 7635 cases and 12,911 controls. The combined results based on all studies showed that there was a statistically significant link between GSTT1 null genotype and colorectal cancer risk (OR = 1.20, 95% CI = 1.03–1.40). In the analysis of ethnic groups, we observed distinct differences associated with GSTT1 null genotype, the pooled odds ratios for the GSTT1 polymorphism were 1.32 in Caucasians (95% CI = 1.09–1.58) and 1.03 in Asians (95% CI = 0.81–1.32). As far as concerned the interaction between GSTT1 genotype and colorectal cancer risk in relation to smoking history, there was no increase in risk for smokers or nonsmokers with the GSTT1 null genotype (smokers: OR = 1.13, 95% CI = 0.80–1.60, nonsmokers: OR = 0.99, 95% CI = 0.71–1.38). When stratifying by the location of colorectal cancer, we found that there was a statistically significant link in rectal cancer (OR = 1.50, 95% CI = 1.09–2.07), but not in colon cancer (OR = 1.33, 95% CI = 0.94–1.88). No associations could be detected between null GSTT1 polymorphism and age, sex, tumor stage and differentiation. Conclusion: Our current study demonstrates that GSTT1 null genotype is associated with an increased risk of colorectal cancer, specifically, among Caucasians.  相似文献   
63.
Postmenopausal Osteoporosis (PMOP) is oestrogen withdrawal characterized of much production and activation by osteoclast in the elderly female. Cytisine is a quinolizidine alkaloid that comes from seeds or other plants of the Leguminosae (Fabaceae) family. Cytisine has been shown several potential pharmacological functions. However, its effects on PMOP remain unknown. This study designed to explore whether Cytisine is able to suppress RANKL‐induced osteoclastogenesis and prevent the bone loss induced by oestrogen deficiency in ovariectomized (OVX) mice. In this study, we investigated the effect of Cytisine on RAW 264.7 cells and bone marrow monocytes (BMMs) derived osteoclast culture system in vitro and observed the effect of Cytisine on ovariectomized (OVX) mice model to imitate postmenopausal osteoporosis in vivo. We found that Cytisine inhibited F‐actin ring formation and tartrate‐resistant acid phosphatase (TRAP) staining in dose‐dependent ways, as well as bone resorption by pit formation assays. For molecular mechanism, Cytisine suppressed RANK‐related trigger RANKL by phosphorylation JNK/ERK/p38‐MAPK, IκBα/p65‐NF‐κB, and PI3K/AKT axis and significantly inhibited these signalling pathways. However, the suppression of PI3K‐AKT‐NFATc1 axis was rescued by AKT activator SC79. Meanwhile, Cytisine inhibited RANKL‐induced RANK‐TRAF6 association and RANKL‐related gene and protein markers such as NFATc1, Cathepsin K, MMP‐9 and TRAP. Our study indicated that Cytisine could suppress bone loss in OVX mouse through inhibited osteoclastogenesis. All data provide the evidence that Cytisine may be a promising agent in the treatment of osteoclast‐related diseases such as osteoporosis.  相似文献   
64.
Biosynthesis of caldariellaquinone in Sulfolobus spp.   总被引:1,自引:2,他引:1       下载免费PDF全文
The biosynthesis of caldariellaquionone (CQ) was studied in species of Sulfolobus by measuring the incorporation of stable isotopically labeled tyrosines into CQ. By feeding a series of tyrosines labeled with deuterium or 13C and then measuring the extent and position at which label was incorporated into CQ by mass spectrometry, it was shown that more than 95% of the label was incorporated into the benzo[b]thiophen-4,7-quinone moiety of CQ. From the labeling experiments, it is concluded that the benzo[b]thiophen-4,7-quinone is derived as an intact unit from all of the carbons of tyrosine except C-1.  相似文献   
65.
66.
Taurine transporter is expressed in vascular smooth muscle cells   总被引:2,自引:0,他引:2  
Liao XB  Zhou XM  Li JM  Tan ZP  Liu LM  Zhang W  Tan H  Lu Y  Yuan LQ 《Amino acids》2007,33(4):639-643
Summary. The regulation of vascular smooth muscle cells (VSMCs) function by taurine has been a subject of increasing interest and investigation, and taurine is taken up into cells through a specific transporter system, the taurine transporter (TAUT). In the present study, we examined the expression of TAUT in VSMCs and the kinetic parameters of the uptake process of TAUT in VSMCs. RT-PCR and western blot demonstrated that the mRNA and protein of TAUT was expressed in VSMCs in vitro. Immunohistochemistry using antibody for TAUT revealed the expression of this protein in rat thoracic aorta. The maximal [3H]taurine uptake rate in VSMCs was 37.75 ± 3.13 pmol/min per mg of protein, with a K m value of 5.42 ± 0.81 μM. Thus, VSMCs are able to express a functional taurine transporter. The regulation and detailed function of taurine and TAUT in VSMCs remain unclear, but our findings suggest a functional role for them in VSMCs metabolism.  相似文献   
67.
BackgroundHIFU has been shown to be a more suitable alternative for the treatment of primary solid tumors and metastatic diseases than other focal heat ablation techniques due to its noninvasive and extracorporeal nature. However, similar to other focal heat ablation techniques, HIFU is still in need of refinements due to tumor recurrence.MethodsIn this work, we investigated the effectiveness of an adjunct treatment regimen using doxorubicin (DOX)-loaded, injectable, in situ-forming, and phase-inverting PLGA as the second line of defense after HIFU ablation to destroy detrimental residual tumors and to prevent tumor recurrence. All of the statistical analyses were performed using the Statistical Package for the Social Sciences 18.0(SPSS, Inc., Chicago, IL, USA), and p< 0.05 was considered statistically significant. All of the results are presented as the means ± STDEV (standard deviation). For multiple comparisons, ANOVA (differences in tumor volumes, growth rates, apoptosis, proliferation indexes, and Bcl-2 and Bax protein levels) was used when the data were normally distributed with homogenous variance, and rank sum tests were used otherwise. Once significant differences were detected, Student-t tests were used for comparisons between two groups.ResultsOur results revealed that DOX diffused beyond the ablated tissue regions and entered tumor cells that were not affected by the HIFU ablation. Our results also show that HIFU in concert with DOX-loaded PLGA led to a significantly higher rate of tumor cell apoptosis and a lower rate of tumor cell proliferation in the areas beyond the HIFU-ablated tissues and consequently caused significant tumor volume shrinkage (tumor volumes:0.26±0.1,1.09±0.76, and 1.42±0.9cm3 for treatment, sham, and no treatment control, respectively).ConclusionsFrom these results, we concluded that the intralesional injection of DOX-loaded PLGA after HIFU ablation is significantly more effective than HIFU alone for the treatment of solid tumors.  相似文献   
68.
Label‐free quantitative imaging is highly desirable for studying live cells by extracting pathophysiological information without perturbing cell functions. Here, we demonstrate a novel label‐free multimodal optical imaging system with the capability of providing comprehensive morphological and molecular attributes of live cells. Our morpho‐molecular microscopy (3M) system draws on the combined strength of quantitative phase microscopy (QPM) and Raman microscopy to probe the morphological features and molecular fingerprinting characteristics of each cell under observation. While the commonr‐path geometry of our QPM system allows for highly sensitive phase measurement, the Raman microscopy is equipped with dual excitation wavelengths and utilizes the same detection and dispersion system, making it a distinctive multi‐wavelength system with a small footprint. We demonstrate the applicability of the 3M system by investigating nucleated and nonnucleated cells. This integrated label‐free platform has a promising potential in preclinical research, as well as in clinical diagnosis in the near future.   相似文献   
69.
70.

Background

Care advances in the United States (US) have led to improved survival of children with neurological impairment (NI). Children with NI may account for an increasing proportion of hospital resources. However, this assumption has not been tested at a national level.

Methods and Findings

We conducted a study of 25,747,016 US hospitalizations of children recorded in the Kids'' Inpatient Database (years 1997, 2000, 2003, and 2006). Children with NI were identified with International Classification of Diseases, 9th Revision, Clinical Modification diagnoses resulting in functional and/or intellectual impairment. We assessed trends in inpatient resource utilization for children with NI with a Mantel-Haenszel chi-square test using all 4 y of data combined. Across the 4 y combined, children with NI accounted for 5.2% (1,338,590) of all hospitalizations. Epilepsy (52.2% [n = 538,978]) and cerebral palsy (15.9% [n = 164,665]) were the most prevalent NI diagnoses. The proportion of hospitalizations attributable to children with NI did not change significantly (p = 0.32) over time. In 2006, children with NI accounted for 5.3% (n = 345,621) of all hospitalizations, 13.9% (n = 3.4 million) of bed days, and 21.6% (US$17.7 billion) of all hospital charges within all hospitals. Over time, the proportion of hospitalizations attributable to children with NI decreased within non-children''s hospitals (3.0% [n = 146,324] in 1997 to 2.5% [n = 113,097] in 2006, p<.001) and increased within children''s hospitals (11.7% [n = 179,324] in 1997 to 13.5% [n = 209,708] in 2006, p<0.001). In 2006, children with NI accounted for 24.7% (2.1 million) of bed days and 29.0% (US$12.0 billion) of hospital charges within children''s hospitals.

Conclusions

Children with NI account for a substantial proportion of inpatient resources utilized in the US. Their impact is growing within children''s hospitals. We must ensure that the current health care system is staffed, educated, and equipped to serve this growing segment of vulnerable children. Please see later in the article for the Editors'' Summary  相似文献   
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