1,193 research outputs found
Attention Maintenance in Novice Drivers: Assessment and Training
All programs assessing attention maintenance inside the vehicle have required eye trackers and either a driving simulator or a specially equipped field vehicle. Ideally, one would like a way to assess attention maintenance that could be implemented on a desktop PC. Additionally, one would like to have a program that could be used to train novice drivers to maintain their attention more safely on the forward roadway. An experiment was run (a) to determine whether a program FOCAL (Focused Concentration and Attention Learning) using a desktop PC could differentiate between the attention maintenance skills of novice and experienced drivers and (b) to determine whether a program that improved the hazard anticipation skills of novice drivers might also improve their attention maintenance skills. FOCAL was able to differentiate between the attention maintenance skills of novice and experienced drivers. However, hazard anticipation training did not improve the attention maintenance skills of the novice drivers
(+)-SJ733, a clinical candidate for malaria that acts through ATP4 to induce rapid host-mediated clearance of Plasmodium
Drug discovery for malaria has been transformed in the last 5 years by the discovery of many new lead compounds identified by phenotypic screening. The process of developing these compounds as drug leads and studying the cellular responses they induce i
Craniofacial surgery for nonmelanoma skin malignancy: Report of an international collaborative study
AbstractBackground.This study examined the efficacy of craniofacial surgery (CFS) in treating locally advanced nonmelanoma skin cancer (NMSC).Methods.One hundred twenty patients who underwent CFS for NMSC were identified from 17 participating institutions. Patient, tumor, and treatment information was analyzed for prognostic impact on survival.Results.Surgical margins were negative in 74%, close in 3%, and involved in 23% of patients. Complications occurred in 35% of patients, half of which were local wound problems. Operative mortality was 4%. Median follow‐up interval after CFS was 27 months. The 5‐year overall survival (OS), disease‐specific survival (DSS), and recurrence‐free survival (RFS) rates were 64%, 75%, and 60%, respectively. Squamous cell histology, brain invasion, and positive resection margins independently predicted worse OS, DSS, and RFS.Conclusion.CFS is an effective treatment for patients with NMSC invading the skull base. Histology, extent of disease, and resection margins are the most significant predictors of outcome. © 2007 Wiley Periodicals, Inc. Head Neck, 200
Nucleosomes protect DNA from DNA methylation in vivo and in vitro
Positioned nucleosomes limit the access of proteins to DNA. However, the impact of nucleosomes on DNA methylation in vitro and in vivo is poorly understood. Here, we performed a detailed analysis of nucleosome binding and nucleosomal DNA methylation by the de novo methyltransferases. We show that compared to linker DNA, nucleosomal DNA is largely devoid of CpG methylation. ATP-dependent chromatin remodelling frees nucleosomal CpG dinucleotides and renders the remodelled nucleosome a 2-fold better substrate for Dnmt3a methyltransferase compared to free DNA. These results reflect the situation in vivo, as quantification of nucleosomal DNA methylation levels in HeLa cells shows a 2-fold decrease of nucleosomal DNA methylation levels compared to linker DNA. Our findings suggest that nucleosomal positions are stably maintained in vivo and nucleosomal occupancy is a major determinant of global DNA methylation patterns in vivo
The interplay of matrix metalloproteinase-8, transforming growth factor-beta 1 and vascular endothelial growth factor-C cooperatively contributes to the aggressiveness of oral tongue squamous cell carcinoma
Background: Matrix metalloproteinase-8 (MMP-8) has oncosuppressive properties in various cancers. We attempted to assess MMP-8 function in oral tongue squamous cell carcinoma (OTSCC). Methods: MMP-8 overexpressing OTSCC cells were used to study the effect of MMP-8 on proliferation, apoptosis, migration, invasion and gene and protein expression. Moreover, MMP-8 functions were assessed in the orthotopic mouse tongue cancer model and by immunohistochemistry in patient samples. Results: MMP-8 reduced the invasion and migration of OTSCC cells and decreased the expression of MMP-1, cathepsin-K and vascular endothelial growth factor-C (VEGF-C). VEGF-C was induced by transforming growth factor-beta 1 (TGF-beta 1) in control cells, but not in MMP-8 overexpressing cells. In human OTSCC samples, low MMP-8 in combination with high VEGF-C was an independent predictor of poor cancer-specific survival. TGF-beta 1 treatment also restored the migration of MMP-8 overexpressing cells to the level of control cells. In mouse tongue cancer, MMP-8 did not inhibit metastasis, possibly because it was eliminated in the peripheral carcinoma cells. Conclusions: The suppressive effects of MMP-8 in OTSCC may be mediated through interference of TGF-beta 1 and VEGF-C function and altered proteinase expression. Together, low MMP-8 and high VEGF-C expression have strong independent prognostic value in OTSCC.Peer reviewe
Predisposition to Cancer Caused by Genetic and Functional Defects of Mammalian Atad5
ATAD5, the human ortholog of yeast Elg1, plays a role in PCNA deubiquitination. Since PCNA modification is important to regulate DNA damage bypass, ATAD5 may be important for suppression of genomic instability in mammals in vivo. To test this hypothesis, we generated heterozygous (Atad5+/m) mice that were haploinsuffficient for Atad5. Atad5+/m mice displayed high levels of genomic instability in vivo, and Atad5+/m mouse embryonic fibroblasts (MEFs) exhibited molecular defects in PCNA deubiquitination in response to DNA damage, as well as DNA damage hypersensitivity and high levels of genomic instability, apoptosis, and aneuploidy. Importantly, 90% of haploinsufficient Atad5+/m mice developed tumors, including sarcomas, carcinomas, and adenocarcinomas, between 11 and 20 months of age. High levels of genomic alterations were evident in tumors that arose in the Atad5+/m mice. Consistent with a role for Atad5 in suppressing tumorigenesis, we also identified somatic mutations of ATAD5 in 4.6% of sporadic human endometrial tumors, including two nonsense mutations that resulted in loss of proper ATAD5 function. Taken together, our findings indicate that loss-of-function mutations in mammalian Atad5 are sufficient to cause genomic instability and tumorigenesis
Exome-Derived Adiponectin-Associated Variants Implicate Obesity and Lipid Biology
Circulating levels of adiponectin, an adipocyte-secreted protein associated with cardiovascular and metabolic risk, are highly heritable. To gain insights into the biology that regulates adiponectin levels, we performed an exome array meta-analysis of 265,780 genetic variants in 67,739 individuals of European, Hispanic, African American, and East Asian ancestry. We identified 20 loci associated with adiponectin, including 11 that had been reported previously (p .60) spanning as much as 900 kb. To identify potential genes and mechanisms through which the previously unreported association signals act to affect adiponectin levels, we assessed cross-trait associations, expression quantitative trait loci in subcutaneous adipose, and biological pathways of nearby genes. Eight of the nine loci were also associated (p <1 x 10(-4)) with at least one obesity or lipid trait. Candidate genes include PRKAR2A, PTH1R, and HDAC9, which have been suggested to play roles in adipocyte differentiation or bone marrow adipose tissue. Taken together, these findings provide further insights into the processes that influence circulating adiponectin levels.Peer reviewe
Genetic Studies of Leptin Concentrations Implicate Leptin in the Regulation of Early Adiposity.
Leptin influences food intake by informing the brain about the status of body fat stores. Rare LEP mutations associated with congenital leptin deficiency cause severe early-onset obesity that can be mitigated by administering leptin. However, the role of genetic regulation of leptin in polygenic obesity remains poorly understood. We performed an exome-based analysis in up to 57,232 individuals of diverse ancestries to identify genetic variants that influence adiposity-adjusted leptin concentrations. We identify five novel variants, including four missense variants, in LEP, ZNF800, KLHL31, and ACTL9, and one intergenic variant near KLF14. The missense variant Val94Met (rs17151919) in LEP was common in individuals of African ancestry only, and its association with lower leptin concentrations was specific to this ancestry (P = 2 × 10-16, n = 3,901). Using in vitro analyses, we show that the Met94 allele decreases leptin secretion. We also show that the Met94 allele is associated with higher BMI in young African-ancestry children but not in adults, suggesting that leptin regulates early adiposity
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