409 research outputs found
High-throughput identification of genotype-specific cancer vulnerabilities in mixtures of barcoded tumor cell lines.
Hundreds of genetically characterized cell lines are available for the discovery of genotype-specific cancer vulnerabilities. However, screening large numbers of compounds against large numbers of cell lines is currently impractical, and such experiments are often difficult to control. Here we report a method called PRISM that allows pooled screening of mixtures of cancer cell lines by labeling each cell line with 24-nucleotide barcodes. PRISM revealed the expected patterns of cell killing seen in conventional (unpooled) assays. In a screen of 102 cell lines across 8,400 compounds, PRISM led to the identification of BRD-7880 as a potent and highly specific inhibitor of aurora kinases B and C. Cell line pools also efficiently formed tumors as xenografts, and PRISM recapitulated the expected pattern of erlotinib sensitivity in vivo
Cost effectiveness of recombinant factor VIIa for treatment of intracerebral hemorrhage
<p>Abstract</p> <p>Background</p> <p>Phase I/II placebo-controlled clinical trials of recombinant Factor VIIa (rFVIIa) suggested that administration of rFVIIa within 4 hours after onset of intracerebral hemorrhage (ICH) is safe, limits ICH growth, and improves outcomes. We sought to determine the cost-effectiveness of rFVIIa for acute ICH treatment, using published Phase II data. We hypothesized that rFVIIa would have a low marginal cost-effectiveness ratio (mCER) given the poor neurologic outcomes after ICH with conventional management.</p> <p>Methods</p> <p>We performed an incremental cost-effectiveness analysis from the societal perspective, considering conventional management vs. 80 ug/kg rFVIIa treatment for acute ICH cases meeting Phase II inclusion criteria. The time frame for the analysis was 1. 25 years: data from the Phase II trial was used for 90 day outcomes and rFVIIa complications – arterial thromboembolic events (ATE). We assumed no substantial cost differences in care between the two strategies except: 1) cost of rFVIIa (for an 80 mcg/kg dose in an 80 kg patient, assumed cost of 50,000/QALY over a wide range of sensitivity analyses. Sensitivity analyses showed that the cost of rFVIIa must exceed 50,000/QALY. Varying the cost and/or reducing the utility of health states following ATE did not impact results.</p> <p>Conclusion</p> <p>Based on data from preliminary trials, treating selected ICH patients with rFVIIa results in lower cost and improved clinical outcomes. This potential cost-effectiveness must be considered in light of the Phase III trial results.</p
Whole-genome sequencing identifies genetic alterations in pediatric low-grade gliomas
The most common pediatric brain tumors are low-grade gliomas (LGGs). We used whole-genome sequencing to identify multiple new genetic alterations involving BRAF, RAF1, FGFR1, MYB, MYBL1 and genes with histone-related functions, including H3F3A and ATRX, in 39 LGGs and low-grade glioneuronal tumors (LGGNTs). Only a single non-silent somatic alteration was detected in 24 of 39 (62%) tumors. Intragenic duplications of the portion of FGFR1 encoding the tyrosine kinase domain (TKD) and rearrangements of MYB were recurrent and mutually exclusive in 53% of grade II diffuse LGGs. Transplantation of Trp53-null neonatal astrocytes expressing FGFR1 with the duplication involving the TKD into the brains of nude mice generated high-grade astrocytomas with short latency and 100% penetrance. FGFR1 with the duplication induced FGFR1 autophosphorylation and upregulation of the MAPK/ERK and PI3K pathways, which could be blocked by specific inhibitors. Focusing on the therapeutically challenging diffuse LGGs, our study of 151 tumors has discovered genetic alterations and potential therapeutic targets across the entire range of pediatric LGGs and LGGNTs.Jinghui Zhang, Gang Wu, Claudia P Miller, Ruth G Tatevossian, James D Dalton, Bo Tang, Wilda Orisme, Chandanamali Punchihewa, Matthew Parker, Ibrahim Qaddoumi, Fredrick A Boop, Charles Lu, Cyriac Kandoth, Li Ding, Ryan Lee, Robert Huether, Xiang Chen, Erin Hedlund, Panduka Nagahawatte, Michael Rusch, Kristy Boggs, Jinjun Cheng, Jared Becksfort, Jing Ma, Guangchun Song, Yongjin Li, Lei Wei, Jianmin Wang, Sheila Shurtleff, John Easton, David Zhao, Robert S Fulton, Lucinda L Fulton, David J Dooling, Bhavin Vadodaria, Heather L Mulder, Chunlao Tang, Kerri Ochoa, Charles G Mullighan, Amar Gajjar, Richard Kriwacki, Denise Sheer, Richard J Gilbertson, Elaine R Mardis, Richard K Wilson, James R Downing, Suzanne J Baker and David W Elliso
Benign perimesencephalic hemorrhage occurring after previous aneurysmal subarachnoid hemorrhage: a case report
<p>Abstract</p> <p>Introduction</p> <p>Both aneurysmal subarachnoid hemorrhage and benign perimesencephalic hemorrhage are well-described causes of spontaneous subarachnoid hemorrhage that arise as a result of different pathologic processes. To the best of the authors' knowledge, there have been no reports of both vascular pathologies occurring in the same individual.</p> <p>Case presentation</p> <p>A 51-year-old Caucasian woman with a history of aneurysmal subarachnoid hemorrhage presented five years after her initial treatment with ictal headache, meningismus, nausea and emesis similar to her previous bleeding event. Computed tomographic imaging revealed perimesencephalic bleeding remote from her previously coiled anterior communicating artery aneurysm. Both immediate and delayed diagnostic angiography revealed no residual filling of the previously coiled aneurysm and no other vascular anomalies, consistent with benign perimesencephalic hemorrhage. The patient had an uneventful hospital course and was discharged to home in good condition.</p> <p>Conclusions</p> <p>This report for the first time identifies benign perimesencephalic hemorrhage occurring in the setting of previous aneurysmal subarachnoid hemorrhage. The presence of a previously treated aneurysm can complicate the process of diagnosing benign perimesencephalic hemorrhage. Fortunately, in this case, the previously treated anterior communicating artery aneurysm was remote from the perimesencephalic hemorrhage and could be ruled out as a source. The patient's prior aneurysmal subarachnoid hemorrhage did not worsen the anticipated good outcome associated with benign perimesencephalic hemorrhage.</p
Association of TNF-α gene with spontaneous deep intracerebral hemorrhage in the Taiwan population: a case control study
<p>Abstract</p> <p>Background</p> <p>Genetic factors may play a role in susceptibility to spontaneous deep intracerebral hemorrhage (SDICH). Previous studies have shown that <it>TNF-α </it>gene variation was associated with risks of subarachnoid hemorrhage in multiple ethnicities. The present case-control study tested the hypothesis that genetic variations of the <it>TNF-α </it>gene may affect the risk of Taiwanese SDICH. We examined the association of SDICH risks with four single nucleotide polymorphisms (SNPs) within the <it>TNF-α </it>gene promoter, namely T-1031C, C-863A, C-857T, and G-308A.</p> <p>Methods</p> <p>Genotyping was determined by PCR-based restriction and electrophoresis assay for 260 SDICH patients and 368 controls. Associations were tested by logistic regression or general linear models with adjusting for multiple covariables in each gender group, and then in combined. Multiplicative terms of gender and each of the four SNPs were applied to detect the interaction effects on SDICH risks. To account for the multiple testing, permutation testing of 1,000 replicates was performed for empirical estimates.</p> <p>Results</p> <p>In an additive model, SDICH risks were positively associated with the minor alleles -1031C and -308A in men (OR = 1.9, 95% CI 1.1 to 3.4, p = 0.03 and OR = 2.6, 95% CI 1.3 to 5.3, p = 0.005, respectively) but inversely associated with -863A in females (OR = 0.5, 95% CI 0.2 to 0.9, p = 0.03). There were significant interaction effects between gender and SNP on SDICH risks regarding SNPs T-1031C, C-863A, and G-308A (p = 0.005, 0.005, and 0.007, respectively). Hemorrhage size was inversely associated with -857T in males (p = 0.04).</p> <p>Conclusions</p> <p>In the Taiwan population, the associations of genetic variations in the <it>TNF-α </it>gene promoter with SDICH risks are gender-dependent.</p
A critique of the World Resources Institute's report "Pesticides and the immune system: the public health risks".
A recent World Resources Institute (WRI) report concluded that pesticides are a likely cause of immune suppression for millions of people throughout the world. The gravity of this conclusion motivated us to review the scientific evidence cited in the report. The predominant human evidence came from cross-sectional studies conducted in the former Soviet Union.These studies were difficult to evaluate due to incomplete reporting and had obvious limitations in terms of subject selection, exposure assessment,lack of quality control, statistical analysis, adequacy of the comparison group, and confounding. The toxicologic evidence was comprised mainly of acute high-dose studies in which the exposure conditions resulted in systemic toxicity. The relevance of these studies to effects at typical human exposure levels is questionable. We did not find consistent, credible evidence to support the conclusion of widespread pesticide-related immune suppression. Nonetheless, the WRI report is an important document because it focuses attention on a potentially important issue for future research and brings a substantial literature of foreign language studies to the attention of Western scientists
Sensitivity and specificity of blood-fluid levels for oral anticoagulant-associated intracerebral haemorrhage
Intracerebral haemorrhage (ICH) is a life-threatening emergency, the incidence of which has increased in part due to an increase in the use of oral anticoagulants. A blood-fluid level within the haematoma, as revealed by computed tomography (CT), has been suggested as a marker for oral anticoagulant-associated ICH (OAC-ICH), but the diagnostic specificity and prognostic value of this finding remains unclear. In 855 patients with CT-confirmed acute ICH scanned within 48 h of symptom onset, we investigated the sensitivity and specificity of the presence of a CT-defined blood-fluid level (rated blinded to anticoagulant status) for identifying concomitant anticoagulant use. We also investigated the association of the presence of a blood-fluid level with six-month case fatality. Eighteen patients (2.1%) had a blood-fluid level identified on CT; of those with a blood-fluid level, 15 (83.3%) were taking anticoagulants. The specificity of blood-fluid level for OAC-ICH was 99.4%; the sensitivity was 4.2%. We could not detect an association between the presence of a blood-fluid level and an increased risk of death at six months (OR = 1.21, 95% CI 0.28–3.88, p = 0.769). The presence of a blood-fluid level should alert clinicians to the possibility of OAC-ICH, but absence of a blood-fluid level is not useful in excluding OAC-ICH
Identifying youth-friendly service practices associated with adolescents’ use of reproductive healthcare services in post-conflict Burundi: a cross-sectional study
BACKGROUND: Very little is known about reproductive health service (RHS) availability and adolescents’ use of these services in post-conflict settings. Such information is crucial for targeted community interventions that aim to improve quality delivery of RHS and outcomes in post-conflict settings. The objectives of this study therefore was to examine the density of RHS availability; assess spatial patterns of RHC facilities; and identify youth-friendly practices associated with adolescents’ use of services in post-conflict Burundi. METHODS: A cross-sectional survey was conducted from a full census of all facilities (n = 892) and provider interviews in Burundi. Surveyed facilities included all public, private, religious and community association owned-centers and hospitals. At each facility efforts were made to interview the officer-in-charge and a group of his/her staff. We applied both geospatial and non-spatial analyses, to examine the density of RHS availability and density, and to explore the association between youth-friendly practices and adolescents’ use of RHS in post-conflict Burundi. RESULTS: High spatial patterning of distances of RHC facilities was observed, with facilities clustered predominantly in districts exhibiting persistent violence. But, use of services remained undeterred. We further found a stronger association between use of RHS and facility and programming characteristics. Community outreach, designated check-in/exam rooms, educational materials (posters, print, and pictures) in waiting rooms, privacy and confidentiality were significantly associated with adolescents’ use of RHS across all facility types. Cost was associated with use only at religious facilities and youth involvement at private facilities. No significant association was found between provider characteristics and use of RHS at any facility. CONCLUSIONS: Our findings indicate the need to improve youth-friendly service practices in the provision of RHS to adolescents in Burundi and suggest that current approaches to provider training may not be adequate for improving these vital practices. Our mixed methods approach and results are generalizable to other countries and post-conflict settings. In post-conflict settings, the methods can be used to identify service availability and spatial patterns of RHC facilities to plan for targeted service interventions, to increase demand and uptake of services by youth and young adults
ILK Induces Cardiomyogenesis in the Human Heart
Integrin-linked kinase (ILK) is a widely conserved serine/threonine kinase that regulates diverse signal transduction pathways implicated in cardiac hypertrophy and contractility. In this study we explored whether experimental overexpression of ILK would up-regulate morphogenesis in the human fetal heart.Primary cultures of human fetal myocardial cells (19-22 weeks gestation) yielded scattered aggregates of cardioblasts positive for the early cardiac lineage marker nk × 2.5 and containing nascent sarcomeres. Cardiac cells in colonies uniformly expressed the gap junction protein connexin 43 (C × 43) and displayed a spectrum of differentiation with only a subset of cells exhibiting the late cardiomyogenic marker troponin T (cTnT) and evidence of electrical excitability. Adenovirus-mediated overexpression of ILK potently increased the number of new aggregates of primitive cardioblasts (p<0.001). The number of cardioblast colonies was significantly decreased (p<0.05) when ILK expression was knocked down with ILK targeted siRNA. Interestingly, overexpression of the activation resistant ILK mutant (ILK(R211A)) resulted in much greater increase in the number of new cell aggregates as compared to overexpression of wild-type ILK (ILK(WT)). The cardiomyogenic effects of ILK(R211A) and ILK(WT) were accompanied by concurrent activation of β-catenin (p<0.001) and increase expression of progenitor cell marker islet-1, which was also observed in lysates of transgenic mice with cardiac-specific over-expression of ILK(R211A) and ILK(WT). Finally, endogenous ILK expression was shown to increase in concert with those of cardiomyogenic markers during directed cardiomyogenic differentiation in human embryonic stem cells (hESCs).In the human fetal heart ILK activation is instructive to the specification of mesodermal precursor cells towards a cardiomyogenic lineage. Induction of cardiomyogenesis by ILK overexpression bypasses the requirement of proximal PI3K activation for transduction of growth factor- and β1-integrin-mediated differentiation signals. Altogether, our data indicate that ILK represents a novel regulatory checkpoint during human cardiomyogenesis
The Saccharomyces cerevisiae Histone Chaperone Rtt106 Mediates the Cell Cycle Recruitment of SWI/SNF and RSC to the HIR-Dependent Histone Genes
In Saccharomyces cerevisiae, three out of the four histone gene pairs (HTA1-HTB1, HHT1-HHF1, and HHT2-HHF2) are regulated by the HIR co-repressor complex. The histone chaperone Rtt106 has recently been shown to be present at these histone gene loci throughout the cell cycle in a HIR- and Asf1-dependent manner and involved in their transcriptional repression. The SWI/SNF and RSC chromatin remodeling complexes are both recruited to the HIR-dependent histone genes; SWI/SNF is required for their activation in S phase, whereas RSC is implicated in their repression outside of S phase. Even though their presence at the histone genes is dependent on the HIR complex, their specific recruitment has not been well characterized. In this study we focused on characterizing the role played by the histone chaperone Rtt106 in the cell cycle-dependent recruitment of SWI/SNF and RSC complexes to the histone genes.Using GST pull-down and co-immunoprecipitation assays, we showed that Rtt106 physically interacts with both the SWI/SNF and RSC complexes in vitro and in vivo. We then investigated the function of this interaction with respect to the recruitment of these complexes to HIR-dependent histone genes. Using chromatin immunoprecipitation assays (ChIP), we found that Rtt106 is important for the recruitment of both SWI/SNF and RSC complexes to the HIR-dependent histone genes. Furthermore, using synchronized cell cultures, we showed by ChIP assays that the Rtt106-dependent SWI/SNF recruitment to these histone gene loci is cell cycle regulated and restricted to late G1 phase just before the peak of histone gene expression in S phase.Overall, these data strongly suggest that the interaction between the histone chaperone Rtt106 and both the SWI/SNF and RSC chromatin remodeling complexes is important for the cell cycle regulated recruitment of these two complexes to the HIR-dependent histone genes
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