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Comparable Frequencies (comparable + frequency)
Selected AbstractsDistinct CpG island methylation profiles and BRAF mutation status in serrated and adenomatous colorectal polypsINTERNATIONAL JOURNAL OF CANCER, Issue 11 2008Yong Ho Kim Abstract A subset of colorectal cancers with CpG island methylator phenotype-high (CIMP-H) is frequently associated with MSI and BRAF V600E mutation. Since limited data are available on different histological types of colorectal polyps, we compared the pattern and the frequency of promoter methylation, CIMP-H, MSI, KRAS and BRAF V600E mutations and the relationship among these molecular parameters and the clinicopathologic characteristics in 110 serrated polyps (48 hyperplastic polyps, 32 sessile serrated adenomas and 30 serrated adenomas) and 32 tubular adenomas using 7 commonly used tumor-associated gene loci. No significant difference in the frequency of overall methylation frequency (86% vs. 100%) and CIMP-H (39% vs. 28%) between serrated polyps and tubular adenomas was observed, but proximally located serrated polyps showed more frequent methylation at 5 of 7 loci examined, and were more likely to be CIMP-H (62% vs. 22%). MGMT methylation was more common in tubular adenomas while MLH1 and HIC1 were more frequently methylated in serrated polyps. BRAF mutation was frequently present in all types of serrated polyps (80%), but was absent in tubular adenomas and was not associated with CIMP or MSI status. These results show comparable frequencies of promoter methylation of tumor-associated genes and CIMP-H, but distinct differences in gene-specific or colonic site-specific methylation profiles occur in serrated polyps and tubular adenomas. BRAF mutation occurs independently of CIMP and MSI in all types of serrated polyps and may serve as a marker of serrated pathway of colorectal carcinogenesis. © 2008 Wiley-Liss, Inc. [source] Variation across the agricultural season in organophosphorus pesticide urinary metabolite levels for Latino farmworkers in eastern North Carolina: Project design and descriptive resultsAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 7 2009Thomas A. Arcury PhD Abstract Background Community Participatory Approach to Measuring Farmworker Pesticide Exposure, PACE3, used a longitudinal design to document pesticide biomarkers among farmworkers. This article presents an overview of PACE3 and provides a descriptive analysis of participant characteristics and one set of pesticide biomarkers, the dialkylphosphate (DAP) urinary metabolites of organophosphorus (OP) pesticides. Methods Two hundred eighty seven farmworkers were recruited during 2007 from 44 farmworker camps in 11 eastern North Carolina counties. Participants provided interviews, urine samples, blood samples, and saliva samples up to four times at monthly intervals beginning in May. A total of 939 data points were collected. Results Farmworkers were largely men (91.3%) from Mexico (94.8%) with a mean age of 33.7 years (SE 0.82); 23.3% spoke an indigenous language. Across all data points, frequencies of detection and median urinary concentrations were 41.3% and 0.96,µg/L for dimethylphosphate (DMP), 78.3% and 3.61,µg/L for dimethylthiophosphate (DMTP), 33.3% and 0.04,µg/L for dimethyldithiophosphate (DMDTP), 40.5% and 0.87,µg/L for diethylphosphate (DEP), 32.3% and 0.17,µg/L for diethylthiophosphate (DETP), and 8.09% and 0.00,µg/L for diethyldithiophosphate (DEDTP). The frequencies of detection and urinary concentrations of the DAP metabolites increased during the season. Conclusions More PACE3 participants were from Mexico, male, migrant workers, and spoke an indigenous language compared to national data. PACE3 participants had comparable frequencies of detection and urinary metabolite concentrations with participants in other studies. Variability in the frequencies of detection and urinary concentrations of the DAP metabolites indicates the importance of longitudinal studies of biomarkers of currently used pesticides in farmworker populations. Am. J. Ind. Med. 52:539,550, 2009. © 2009 Wiley-Liss, Inc. [source] Contribution of Naïve and Memory T-Cell Populations to the Human Alloimmune ResponseAMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2009C. Macedo T-cell alloimmunity plays a dominant role in allograft rejection. The precise contribution of naïve and memory T cells to this response however remains unclear. To address this question, we established an ex vivo flow-cytometric assay that simultaneously measures proliferation, precursor frequency and effector molecule (IFN,, granzyme B/perforin) production of alloreactive T cells. By applying this assay to peripheral blood mononuclear cells from healthy volunteers, we demonstrate that the CD4+ and CD8+ populations mount similar proliferative responses and contain comparable frequencies of alloreactive precursors. Effector molecule expression, however, was significantly higher among CD8+ T cells. Analysis of sorted naïve and memory T cells showed that alloreactive precursors were equally present in both populations. The CD8+ effector and terminally differentiated effector memory subsets contained the highest proportion of granzyme B/perforin after allostimulation, suggesting that these cells present a significant threat to transplanted organs. Finally, we demonstrate that virus-specific lymphocytes contribute significantly to the alloresponse in certain responder,stimulator HLA combinations, underscoring the importance of T-cell cross-reactivity in alloimmunity. These results provide a quantitative assessment of the roles of naïve and memory T-cell subsets in the normal human alloimmune response and establish a platform for measuring T-cell alloreactivity pre- and posttransplantation. [source] The effect of screening for cardio-renal risk factors on drug use in the general populationBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 6 2007Jarir Atthobari What is already know about this subject ,,Screening of the population may result in medicalization. ,,There is no report about the effect of a health screening programme on drug prescribing. What this study adds ,,Screening of the general population for cardiovascular risk factors does not lead to more drug prescribing, for either screening-related or screening-unrelated drugs. ,,The incidence of drug use increases in screened subjects with high risk, but only for drugs related to the purpose of screening. ,,For screening to be successful, i.e. increased drug use in the detected diseased subjects, it has to be performed in a population expected to be at increased risk. Aim To evaluate the effect of a cardio-renal screening programme on desired and undue drug use. Methods Data from the PREVEND cohort (Prevention of REnal and Vascular ENd-stage Disease) were used. The drug use of screened (randomly) selected subjects (n = 2650) was compared with unscreened subjects, matched for age and sex (n = 10 434). Drug use in the overall PREVEND cohort, enriched for albuminuria (n = 6751), was also studied. Screening-related drugs (antihypertensive, antilipidaemic, antidiabetic and antithrombotic) were selected, as well as screening-unrelated drugs (benzodiazepines, drugs for acid-related disorders and painkillers). Time to first prescription after screening is presented as Kaplan,Meier curves. Results After 6.5 years of follow-up, the incidence of drug use was not significantly different between the screened, randomly selected and unscreened cohorts. Antihypertensives were used by 21.5 and 20.8%, respectively; antilipidaemic 12.8 and 10.2%, antidiabetics 4.0 and 3.9%, and antithrombotic 11.4 and 12.0%. Screening-unrelated drugs were used at comparable frequencies. Compared with the unscreened cohort, screening-related drugs were prescribed more frequently for subjects in the enriched cohort (25.8, 15.5, 5.5 and 13.5% for antihypertensive, antilipidaemic, antidiabetic and antithrombotic, respectively), whereas screening-unrelated drugs were used at comparable frequencies. Conclusions The incidence of drug use did not differ between the screened, randomly selected and unscreened cohorts. Screening does not lead to more drug prescription, thus arguing against the fear of undue medicalization after screening. The data also show that, for screening to be successful, it should be performed in a targeted population, such as one enriched for albuminuria. [source] | ||||||||||