768 research outputs found
International standards for early fetal size and pregnancy dating based on ultrasound measurement of crown-rump length in the first trimester of pregnancy.
OBJECTIVES: There are no international standards for relating fetal crown-rump length (CRL) to gestational age (GA), and most existing charts have considerable methodological limitations. The INTERGROWTH-21(st) Project aimed to produce the first international standards for early fetal size and ultrasound dating of pregnancy based on CRL measurement.
METHODS: Urban areas in eight geographically diverse countries that met strict eligibility criteria were selected for the prospective, population-based recruitment, between 9 + 0 and 13 + 6 weeks' gestation, of healthy well-nourished women with singleton pregnancies at low risk of fetal growth impairment. GA was calculated on the basis of a certain last menstrual period, regular menstrual cycle and lack of hormonal medication or breastfeeding in the preceding 2 months. CRL was measured using strict protocols and quality-control measures. All women were followed up throughout pregnancy until delivery and hospital discharge. Cases of neonatal and fetal death, severe pregnancy complications and congenital abnormalities were excluded from the study.
RESULTS: A total of 4607 women were enrolled in the Fetal Growth Longitudinal Study, one of the three main components of the INTERGROWTH-21(st) Project, of whom 4321 had a live singleton birth in the absence of severe maternal conditions or congenital abnormalities detected by ultrasound or at birth. The CRL was measured in 56 women at < 9 + 0 weeks' gestation; these were excluded, resulting in 4265 women who contributed data to the final analysis. The mean CRL and SD increased with GA almost linearly, and their relationship to GA is given by the following two equations (in which GA is in days and CRL in mm): mean CRL = -50.6562 + (0.815118 × GA) + (0.00535302 × GA(2) ); and SD of CRL = -2.21626 + (0.0984894 × GA).
GA estimation is carried out according to the two equations: GA = 40.9041 + (3.21585 × CRL(0.5) ) + (0.348956 × CRL); and SD of GA = 2.39102 + (0.0193474 × CRL).
CONCLUSIONS: We have produced international prescriptive standards for early fetal linear size and ultrasound dating of pregnancy in the first trimester that can be used throughout the world
MiR-24 Tumor Suppressor Activity Is Regulated Independent of p53 and through a Target Site Polymorphism
MicroRNAs (miRNAs) are predicted to regulate approximately 30% of all human genes; however, only a few miRNAs have been assigned their targets and specific functions. Here we demonstrate that miR-24, a ubiquitously expressed miRNA, has an anti-proliferative effect independent of p53 function. Cell lines with differential p53 status were used as a model to study the effects of miR-24 on cell proliferation, cell cycle control, gene regulation and cellular transformation. Overexpression of miR-24 in six different cell lines, independent of p53 function, inhibited cell proliferation and resulted in G2/S cell cycle arrest. MiR-24 over expression in cells with wt-p53 upregulated TP53 and p21 protein; however, in p53-null cells miR-24 still induced cell cycle arrest without the involvement of p21. We show that miR-24 regulates p53-independent cellular proliferation by regulating an S-phase enzyme, dihydrofolate reductase (DHFR) a target of the chemotherapeutic drug methotrexate (MTX). Of interest, we found that a miR-24 target site polymorphism in DHFR 3′ UTR that results in loss of miR-24-function and high DHFR levels in the cell imparts a growth advantage to immortalized cells and induces neoplastic transformation. Of clinical significance, we found that miR-24 is deregulated in human colorectal cancer tumors and a subset of tumors has reduced levels of miR-24. A novel function for miR-24 as a p53-independent cell cycle inhibitory miRNA is proposed
Chemosensory abilities in consumers of a western-style diet
People vary in their habitual diet and also in their chemosensory abilities. In this study we examined whether consumption of a Western-style diet, rich in saturated fat and added sugar, is associated with either poorer or different patterns of chemosensory perception, relative to people who consume a healthier diet. Participants were selected based on a food frequency questionnaire, which established whether they were likely to consume a diet either higher or lower in saturated fat and added sugar. Eighty-seven participants were tested for olfactory ability (threshold, discrimination, identification), gustatory ability (PROP sensitivity, taste intensity, quality and hedonics), and flavour processing (using dairy fat-sugar-odour mixtures). A Western-style diet was associated with poorer odour identification ability, greater PROP sensitivity, poorer fat discrimination, different patterns of sweetness taste enhancement, and hedonic differences in taste and flavour perception. No differences were evident for odour discrimination or threshold, in perception of taste intensity/quality (excluding PROP) or the ability of fats to affect flavour perception. The significant relationships were of small to moderate effect size, and would be expected to work against consuming a healthier diet. The discussion focuses on whether these diet-related differences precede adoption of a Western-style diet and/or are a consequence of it
Clinical actionability of comprehensive genomic profiling for management of rare or refractory cancers
Background.
The frequency with which targeted tumor sequencing results will lead to implemented change in care is unclear. Prospective assessment of the feasibility and limitations of using genomic sequencing is critically important.
Methods.
A prospective clinical study was conducted on 100 patients with diverse-histology, rare, or poor-prognosis cancers to evaluate the clinical actionability of a Clinical Laboratory Improvement Amendments (CLIA)-certified, comprehensive genomic profiling assay (FoundationOne), using formalin-fixed, paraffin-embedded tumors. The primary objectives were to assess utility, feasibility, and limitations of genomic sequencing for genomically guided therapy or other clinical purpose in the setting of a multidisciplinary molecular tumor board.
Results.
Of the tumors from the 92 patients with sufficient tissue, 88 (96%) had at least one genomic alteration (average 3.6, range 0–10). Commonly altered pathways included p53 (46%), RAS/RAF/MAPK (rat sarcoma; rapidly accelerated fibrosarcoma; mitogen-activated protein kinase) (45%), receptor tyrosine kinases/ligand (44%), PI3K/AKT/mTOR (phosphatidylinositol-4,5-bisphosphate 3-kinase; protein kinase B; mammalian target of rapamycin) (35%), transcription factors/regulators (31%), and cell cycle regulators (30%). Many low frequency but potentially actionable alterations were identified in diverse histologies. Use of comprehensive profiling led to implementable clinical action in 35% of tumors with genomic alterations, including genomically guided therapy, diagnostic modification, and trigger for germline genetic testing.
Conclusion.
Use of targeted next-generation sequencing in the setting of an institutional molecular tumor board led to implementable clinical action in more than one third of patients with rare and poor-prognosis cancers. Major barriers to implementation of genomically guided therapy were clinical status of the patient and drug access. Early and serial sequencing in the clinical course and expanded access to genomically guided early-phase clinical trials and targeted agents may increase actionability.
Implications for Practice:
Identification of key factors that facilitate use of genomic tumor testing results and implementation of genomically guided therapy may lead to enhanced benefit for patients with rare or difficult to treat cancers. Clinical use of a targeted next-generation sequencing assay in the setting of an institutional molecular tumor board led to implementable clinical action in over one third of patients with rare and poor prognosis cancers. The major barriers to implementation of genomically guided therapy were clinical status of the patient and drug access both on trial and off label. Approaches to increase actionability include early and serial sequencing in the clinical course and expanded access to genomically guided early phase clinical trials and targeted agents
Efficient Generation of Multipotent Mesenchymal Stem Cells from Umbilical Cord Blood in Stroma-Free Liquid Culture
BACKGROUND: Haematopoiesis is sustained by haematopoietic (HSC) and mesenchymal stem cells (MSC). HSC are the precursors for blood cells, whereas marrow, stroma, bone, cartilage, muscle and connective tissues derive from MSC. The generation of MSC from umbilical cord blood (UCB) is possible, but with low and unpredictable success. Here we describe a novel, robust stroma-free dual cell culture system for long-term expansion of primitive UCB-derived MSC.
METHODS AND FINDINGS: UCB-derived mononuclear cells (MNC) or selected CD34(+) cells were grown in liquid culture in the presence of serum and cytokines. Out of 32 different culture conditions that have been tested for the efficient expansion of HSC, we identified one condition (DMEM, pooled human AB serum, Flt-3 ligand, SCF, MGDF and IL-6; further denoted as D7) which, besides supporting HSC expansion, successfully enabled long-term expansion of stromal/MSC from 8 out of 8 UCB units (5 MNC-derived and 3 CD34(+) selected cells). Expanded MSC displayed a fibroblast-like morphology, expressed several stromal/MSC-related antigens (CD105, CD73, CD29, CD44, CD133 and Nestin) but were negative for haematopoietic cell markers (CD45, CD34 and CD14). MSC stemness phenotype and their differentiation capacity in vitro before and after high dilution were preserved throughout long-term culture. Even at passage 24 cells remained Nestin(+), CD133(+) and >95% were positive for CD105, CD73, CD29 and CD44 with the capacity to differentiate into mesodermal lineages. Similarly we show that UCB derived MSC express pluripotency stem cell markers despite differences in cell confluency and culture passages. Further, we generated MSC from peripheral blood (PB) MNC of 8 healthy volunteers. In all cases, the resulting MSC expressed MSC-related antigens and showed the capacity to form CFU-F colonies.
CONCLUSIONS: This novel stroma-free liquid culture overcomes the existing limitation in obtaining MSC from UCB and PB enabling so far unmet therapeutic applications, which might substantially affect clinical practice
Limited Sampling Strategy to Predict AUC of the CYP3A Phenotyping Probe Midazolam in Adults: Application to Various Assay Techniques
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97211/1/00912700222011418.pd
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