44 research outputs found

    Blood DNA methylation and breast cancer risk: a meta-analysis of four prospective cohort studies

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    BACKGROUND: Environmental and genetic factors play an important role in the etiology of breast cancer. Several small blood-based DNA methylation studies have reported risk associations with methylation at individual CpGs and average methylation levels; however, these findings require validation in larger prospective cohort studies. To investigate the role of blood DNA methylation on breast cancer risk, we conducted a meta-analysis of four prospective cohort studies, including a total of 1663 incident cases and 1885 controls, the largest study of blood DNA methylation and breast cancer risk to date. METHODS: We assessed associations with methylation at 365,145 CpGs present in the HumanMethylation450 (HM450K) Beadchip, after excluding CpGs that did not pass quality controls in all studies. Each of the four cohorts estimated odds ratios (ORs) and 95% confidence intervals (CI) for the association between each individual CpG and breast cancer risk. In addition, each study assessed the association between average methylation measures and breast cancer risk, adjusted and unadjusted for cell-type composition. Study-specific ORs were combined using fixed-effect meta-analysis with inverse variance weights. Stratified analyses were conducted by age at diagnosis ( 10 years). The false discovery rate (q value) was used to account for multiple testing. RESULTS: The average age at blood draw ranged from 52.2 to 62.2 years across the four cohorts. Median follow-up time ranged from 6.6 to 8.4 years. The methylation measured at individual CpGs was not associated with breast cancer risk (q value > 0.59). In addition, higher average methylation level was not associated with risk of breast cancer (OR = 0.94, 95% CI = 0.85, 1.05; P = 0.26; P for study heterogeneity = 0.86). We found no evidence of modification of this association by age at diagnosis (P = 0.17), ER status (P = 0.88), time since blood collection (P = 0.98), or CpG location (P = 0.98). CONCLUSIONS: Our data indicate that DNA methylation measured in the blood prior to breast cancer diagnosis in predominantly postmenopausal women is unlikely to be associated with substantial breast cancer risk on the HM450K array. Larger studies or with greater methylation coverage are needed to determine if associations exist between blood DNA methylation and breast cancer risk

    Evaluation of procalcitonin for diagnosis of neonatal sepsis of vertical transmission

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    BACKGROUND: The results of recent studies suggest the usefulness of PCT for early diagnosis of neonatal sepsis, with varying results. The aim of this prospective multicenter study was to determine the behavior of serum PCT concentrations in both uninfected and infected neonates, and to assess the value of this marker for diagnosis of neonatal sepsis of vertical transmission. METHODS: PCT was measured in 827 blood samples collected prospectively from 317 neonates admitted to 13 acute-care teaching hospitals in Spain over one year. Serum PCT concentrations were determined by a specific immunoluminometric assay. The diagnostic efficacy of PCT at birth and within 12–24 h and 36–48 h of life was evaluated calculating the sensitivity, specificity, and likelihood ratio of positive and negative results. RESULTS: 169 asymptomatic newborns and 148 symptomatic newborns (confirmed vertical sepsis: 31, vertical clinical sepsis: 38, non-infectious diseases: 79) were studied. In asymptomatic neonates, PCT values at 12–24 h were significantly higher than at birth and at 36–48 h of life. Resuscitation at birth and chorioamnionitis were independently associated to PCT values. Neonates with confirmed vertical sepsis showed significantly higher PCT values than those with clinical sepsis. PCT thresholds for the diagnosis of sepsis were 0.55 ng/mL at birth (sensitivity 75.4%, specificity 72.3%); 4.7 ng/mL within 12–24 h of life (sensitivity 73.8%, specificity 80.8%); and 1.7 ng/mL within 36–48 h of life (sensitivity 77.6%, specificity 79.2%). CONCLUSION: Serum PCT was moderately useful for the detection of sepsis of vertical transmission, and its reliability as a maker of bacterial infection requires specific cutoff values for each evaluation point over the first 48 h of life

    Pai syndromee: first patient with agenesis of the corpus callosum and literature review.

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    BACKGROUND: Pai syndrome (PS) is a rare regional developmental defect of the face, mainly characterized by the variable association of midline cleft of the upper lip (MCL), duplicated maxillary median frenulum, and midline facial cutaneous and midanterior alveolar process polyps. Its entire clinical spectrum is still poorly delineated and the etiology remains unknown. CASE: We describe a 1-month-old boy presenting with MCL, left nostril hamartomatous mass, midline pedunculated polyp originating from the columella base, midline alveolar cleft, duplication of the upper median frenulum, unilateral persistent papillary membrane, lipoma of the corpus callosum, and additional minor facial dysmorphism. This patient also presents with agenesis of the corpus callosum, which has never been reported in PS. Literature review was carried out comparing clinical data of the 20 previously published patients with those observed in the present case. CONCLUSIONS: The minimum diagnostic criteria for PS has been fixed in one or more hamartomatous nasal polyps plus MCL (with or without cleft alveolus) and/or midanterior alveolar process congenital polyp. Additional common ancillary findings include duplicated median maxillary frenulum, hypertelorism, nasal cleft, midfrontal skin tags, and ocular and CNS structural abnormalities. However, mental retardation is only an occasional feature and seems to be related to coexisting conditions (such as chromosome imbalance). Literature review shows that PS is etiologically heterogeneous, as it may result from chromosome abnormalities and environmental/stochastic events, as well as de novo mutations

    Use of neutron absorbers for the experimental determination of lattice parameters in subcritical assemblies.

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    Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1966.Bibliography: leaves 188-192.Sc.D
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