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141.
Isotopic analyses are now official or standard methods in Europe and North America for routine use in testing the authenticity of several food products. These methods are based on the measurement of stable isotope content (2H, 13C, 18O) of the product or of a specific component such as an ingredient or target molecule of the product. The determinations carried out using nuclear magnetic resonance (NMR), and Isotopic Ratio Mass Spectrometry (IRMS), provide information on the botanical and geographical origin of the food product. A deuterium natural abundance quantitative NMR method (SNIF-NMR: Site-specific Natural Isotope Fractionation) was developed as an efficient and powerful tool capable of characterizing the chemical origins of organic molecules and distinguishing their biological and geographical origin. The SNIF method is based on the measurement of deuterium / hydrogen (D/H) ratios at the specific sites of the ethanol. Using these methods, we present the obtained results for a series of Romanian wines. Our results may be used like reference data set for authenticity and origin control of wines.  相似文献   
142.
Both NK cells and CTLs kill virus-infected and tumor cells. However, the ways by which these killer cells recognize the infected or the tumorigenic cells are different, in fact almost opposite. CTLs are activated through the interaction of the TCR with MHC class I proteins. In contrast, NK cells are inhibited by MHC class I molecules. The inhibitory NK receptors recognize mainly MHC class I proteins and in this regard practically all of the HLA-C proteins are recognized by inhibitory NK cell receptors, while only certain HLA-A and HLA-B proteins interact with these receptors. Sophisticated viruses developed mechanisms to avoid the attack of both NK cells and CTLs through, for example, down regulation of HLA-A and HLA-B molecules to avoid CTL recognition, leaving HLA-C proteins on the cell surface to inhibit NK cell response. Here we provide the first example of a virus that through specific down regulation of HLA-C, harness the NK cells for its own benefit. We initially demonstrated that none of the tested HSV-2 derived microRNAs affect NK cell activity. Then we show that surprisingly upon HSV-2 infection, HLA-C proteins are specifically down regulated, rendering the infected cells susceptible to NK cell attack. We identified a motif in the tail of HLA-C that is responsible for the HSV-2-meduiated HLA-C down regulation and we show that the HLA-C down regulation is mediated by the viral protein ICP47. Finally we show that HLA-C proteins are down regulated from the surface of HSV-2 infected dendritic cells (DCs) and that this leads to the killing of DC by NK cells. Thus, we propose that HSV-2 had developed this unique and surprising NK cell-mediated killing strategy of infected DC to prevent the activation of the adaptive immunity.  相似文献   
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Habitat fragmentation due to both natural and anthropogenic forces continues to threaten the evolution and maintenance of biological diversity. This is of particular concern in tropical regions that are experiencing elevated rates of habitat loss. Although less well-studied than tropical rain forests, tropical dry forests (TDF) contain an enormous diversity of species and continue to be threatened by anthropogenic activities including grazing and agriculture. However, little is known about the processes that shape genetic connectivity in species inhabiting TDF ecosystems. We adopt a landscape genetic approach to understanding functional connectivity for leaf-toed geckos (Phyllodactylus tuberculosus) at multiple sites near the northernmost limit of this ecosystem at Alamos, Sonora, Mexico. Traditional analyses of population genetics are combined with multivariate GIS-based landscape analyses to test hypotheses on the potential drivers of spatial genetic variation. Moderate levels of within-population diversity and substantial levels of population differentiation are revealed by F ST and D est. Analyses using structure suggest the occurrence of from 2 to 9 genetic clusters depending on the model used. Landscape genetic analysis suggests that forest cover, stream connectivity, undisturbed habitat, slope, and minimum temperature of the coldest period explain more genetic variation than do simple Euclidean distances. Additional landscape genetic studies throughout TDF habitat are required to understand species-specific responses to landscape and climate change and to identify common drivers. We urge researchers interested in using multivariate distance methods to test for, and report, significant correlations among predictor matrices that can impact results, particularly when adopting least-cost path approaches. Further investigation into the use of information theoretic approaches for model selection is also warranted.  相似文献   
147.
The accumulation of β-amyloid peptides in the brain has been recognized as an essential factor in Alzheimer’s disease pathology. Several proteases, including Neprilysin (NEP), endothelin converting enzyme (ECE), and insulin degrading enzyme (IDE), have been shown to cleave β-amyloid peptides (Aβ). We have previously reported reductions in amyloid in APP+PS1 mice with increased expression of ECE. In this study we compared the vector-induced increased expression of NEP and IDE. We used recombinant adeno-associated viral vectors expressing either native forms of NEP (NEP-n) or IDE (IDE-n), or engineered secreted forms of NEP (NEP-s) or IDE (IDE-s). In a six-week study, immunohistochemistry staining for total Aβ was significantly decreased in animals receiving the NEP-n and NEP-s but not for IDE-n or IDE-s in either the hippocampus or cortex. Congo red staining followed a similar trend revealing significant decreases in the hippocampus and the cortex for NEP-n and NEP-s treatment groups. Our results indicate that while rAAV-IDE does not have the same therapeutic potential as rAAV-NEP, rAAV-NEP-s and NEP-n are effective at reducing amyloid loads, and both of these vectors continue to have significant effects nine months post-injection. As such, they may be considered reasonable candidates for gene therapy trials in AD.  相似文献   
148.
TGF-β family members play a relevant role in tumorigenic processes, including hepatocellular carcinoma (HCC), but a specific implication of the Bone Morphogenetic Protein (BMP) subfamily is still unknown. Although originally isolated from fetal liver, little is known about BMP9, a BMP family member, and its role in liver physiology and pathology. Our results show that BMP9 promotes growth in HCC cells, but not in immortalized human hepatocytes. In the liver cancer cell line HepG2, BMP9 triggers Smad1,5,8 phosphorylation and inhibitor of DNA binding 1 (Id1) expression up- regulation. Importantly, by using chemical inhibitors, ligand trap and gene silencing approaches we demonstrate that HepG2 cells autocrinely produce BMP9 that supports their proliferation and anchorage independent growth. Additionally, our data reveal that in HepG2 cells BMP9 triggers cell cycle progression, and strikingly, completely abolishes the increase in the percentage of apoptotic cells induced by long-term incubation in low serum. Collectively, our data unveil a dual role for BMP9, both promoting a proliferative response and exerting a remarkable anti-apoptotic function in HepG2 cells, which result in a robust BMP9 effect on liver cancer cell growth. Finally, we show that BMP9 expression is increased in 40% of human HCC tissues compared with normal human liver as revealed by immunohistochemistry analysis, suggesting that BMP9 signaling may be relevant during hepatocarcinogenesis in vivo. Our findings provide new clues for a better understanding of BMPs contribution, and in particular BMP9, in HCC pathogenesis that may result in the development of effective and targeted therapeutic interventions.  相似文献   
149.
Cabozantinib is an inhibitor of multiple receptor tyrosine kinases, including MET and VEGFR2. In a phase II clinical trial in advanced prostate cancer (PCa), cabozantinib treatment improved bone scans in 68% of evaluable patients. Our studies aimed to determine the expression of cabozantinib targets during PCa progression and to evaluate its efficacy in hormone-sensitive and castration-resistant PCa in preclinical models while delineating its effects on tumor and bone. Using immunohistochemistry and tissue microarrays containing normal prostate, primary PCa, and soft tissue and bone metastases, our data show that levels of MET, P-MET, and VEGFR2 are increasing during PCa progression. Our data also show that the expression of cabozantinib targets are particularly pronounced in bone metastases. To evaluate cabozantinib efficacy on PCa growth in the bone environment and in soft tissues we used androgen-sensitive LuCaP 23.1 and castration-resistant C4-2B PCa tumors. In vivo, cabozantinib inhibited the growth of PCa in bone as well as growth of subcutaneous tumors. Furthermore, cabozantinib treatment attenuated the bone response to the tumor and resulted in increased normal bone volume. In summary, the expression pattern of cabozantinib targets in primary and castration-resistant metastatic PCa, and its efficacy in two different models of PCa suggest that this agent has a strong potential for the effective treatment of PCa at different stages of the disease.  相似文献   
150.

Objectives

To date, limited and inconsistent evidence exists regarding racial discrimination and risk of cardiovascular disease (CVD).

Methods

Cross-sectional observational study of 1005 US-born non-Hispanic black (n = 504) and white (n = 501) participants age 35–64 randomly selected from community health centers in Boston, MA (2008–2010; 82.4% response rate), using 3 racial discrimination measures: explicit self-report; implicit association test (IAT, a time reaction test for self and group as target vs. perpetrator of discrimination); and structural (Jim Crow status of state of birth, i.e. legal racial discrimination prior 1964).

Results

Black and white participants both had adverse cardiovascular and socioeconomic profiles, with black participants most highly exposed to racial discrimination. Positive crude associations among black participants occurred for Jim Crow birthplace and hypertension (odds ratio (OR) 1.92, 95% confidence interval (CI) 1.28, 2.89) and for explicit self-report and the Framingham 10 year CVD risk score (beta  = 0.04; 95% CI 0.01, 0.07); among white participants, only negative crude associations existed (for IAT for self, for lower systolic blood pressure (SBP; beta  = −4.86; 95% CI −9.08, −0.64) and lower Framingham CVD score (beta  = −0.36, 95% CI −0.63, −0.08)). All of these associations were attenuated and all but the white IAT-Framingham risk score association were rendered null in analyses that controlled for lifetime socioeconomic position and additional covariates. Controlling for racial discrimination, socioeconomic position, and other covariates did not attenuate the crude black excess risk for SBP and hypertension and left unaffected the null excess risk for the Framingham CVD score.

Conclusion

Despite worse exposures among the black participants, racial discrimination and socioeconomic position were not associated, in multivariable analyses, with risk of CVD. We interpret results in relation to constrained variability of exposures and outcomes and discuss implications for valid research on social determinants of health.  相似文献   
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