Replication profile of PCDH11X and PCDH11Y, a gene pair located in the non-pseudoautosomal homologous region Xq21.3/Yp11.2.

In order to investigate the replication timing properties of PCDH11X and PCDH11Y, a pair of protocadherin genes located in the hominid-specific non-pseudoautosomal homologous region Xq21.3/Yp11.2, we conducted a FISH-based comparative study in different human and non-human primate (Gorilla gorilla) cell types. The replication profiles of three genes from different regions of chromosome X (ZFX, XIST and ATRX) were used as terms of reference. Particular emphasis was given to the evaluation of allelic replication asynchrony in relation to the inactivation status of each gene. The human cell types analysed include neuronal cells and ICF syndrome cells, considered to be a model system for the study of X inactivation. PCDH11 appeared to be generally characterized by replication asynchrony in both male and female cells, and no significant differences were observed between human and gorilla, in which this gene lacks X-Y homologous status. However, in differentiated human neuroblastoma and cerebral cortical cells PCDH11X replication profile showed a significant shift towards allelic synchrony. Our data are relevant to the complex relationship between X-inactivation, as a chromosome-wide phenomenon, and asynchrony of replication and expression status of single genes on chromosome X.

An event-by-event probabilistic methodology for assessing the health risks of persistent chemicals in fish: a case study at the Palos Verdes Shelf.

A human health risk assessment of recreational anglers who consume fish from the Palos Verdes Shelf was conducted. The uptake of DDT, DDE, and DDD (collectively total DDT or tDDT) and polychlorinated biphenyls (PCBs) due to fish ingestion was characterized using Monte Carlo techniques. This analysis relied upon 176 probability density functions developed from over 300,000 individual pieces of information to represent 17 different exposure factors that influence the human uptake of persistent organic chemicals in fish. The carcinogenic and noncarcinogenic risks were estimated using a microexposure event modeling approach that estimates exposure on an event-by-event basis. This evaluation relied upon several large studies that provided site-specific data on angler behavior and concentratioins of chemicals in 13 fish species. Our results indicate that the median theoretical increased lifetime cancer risk associated with estimated exposure to tDDT and PCBs was 5 x 10(-8) for anglers who fish on commercial passenger fishing vessels (CPFVs) and who catch and eat fish from the Palos Verdes Shelf. The mean risk for these anglers was 2 x 10(-7), and the 95th percentile risk was 8 x 10(-7). At the 9.5th percentile, the hazard quotients for anglers were less than 1, indicating that noncancer effects are unlikely. These results are in contrast with prior risk assessments of this site that suggested that consumption of white croaker alone posed a cancer risk of 2 x 10(-3) and a hazard quotient of 32. Our results were validated by their agreement with several independent local studies regarding fishing and consumption practices. This assessment indicates that the levels of tDDT and PCB in fish at the Palos Verdes Shelf do not pose a significant risk to human health among recreational anglers. Based on the size of the local angler population, no cases of cancer would be expected to result from eating Palos Verdes Shelf fish. The methodology used here should be applicable to characterizing the risks to those who ingest fish from the waterways of most industrialized nations.

A near-infrared method for the assay of cineole in eucalyptus oil as an alternative to the official BP method.

Thirty different eucalyptus oil samples were scanned on the FOSS NIRSystems 6500 Rapid Content Sampler using a reflectance vessel as sample presentation method. The cineole content of each sample was determined by the BP method and these reference data were used to construct two calibration equations for cineole content in the oils using Vision software. The mean accuracy for the NIR method differed by 1.01% or less, and the mean bias by +/-0.33% or less, compared with the BP method. Calculation of the 95% confidence intervals for the slope and intercept of plots of NIR predicted values against BP method reference values showed that there was no evidence of fixed or relative systematic errors. Tests for short-term and intermediate repeatability were conducted. The standard deviation was 0.83% w/w or less and the coefficient of variation was 1.11% or less. The confidence intervals for both short-term and intermediate repeatability overlapped with that for the BP method, suggesting that there was no evidence for a difference in values obtained by the BP and NIR methods. The range of cineole contents used in the calibrations was extended by incorporating five samples of eucalyptus oil spiked with cineole, and five samples of two essential oils known to have a lower cineole content than eucalyptus oil, to give a range of 52.5 to 99.0% w/w. The mean accuracy decreased to an error of 1.26% or less and the bias to +/-0.50% or less. Again, confidence intervals suggested there was no evidence for fixed or systematic errors in the NIR calibrations. We propose that NIR spectroscopy could be used as an alternative method for the determination of cineole content in eucalyptus oils.

The effect of cooking practices on the concentration of DDT and PCB compounds in the edible tissue of fish.

Chemical contaminants in fish can be an important source of human exposure to chemicals. Assessments of the fish consumption pathway need to adjust the concentrations of the chemical to account for reductions in 1,1-bis(4-chlorophenyl)-2,2-dichloroethane (DDD), dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyltrichloroethane (DDT) (herein collectively referred to as total DDT or tDDT) and polychlorinated biphenyls (PCBs) that can occur during cooking. The results of this analysis indicate that baking, frying, broiling, boiling, smoking, and microwaving all effectively reduce the concentrations of tDDT and PCBs in fish tissue. Average reductions in tDDT ranged from 16 to 55% depending on the cooking method. Similar reductions in PCBs ranged from 26 to 68%. An evaluation of the factors influencing the degree of cooking loss indicated that neither initial chemical mass in the raw fillet, fillet lipid content, nor skin removal were significant predictors of the percent reduction in tDDT or PCB.

Changing patterns of breast cancer.

Changes in treatment of breast cancer are high-lighted as follows: 1) Outpatient breast biopsy offers advantages in planning treatment and also saves money, 2) Mammograms are increasing the numbers of breast tumors found early, 3) For many reasons modified mastectomy is finding increasing use, 4) Breast cancer appears to be multifocal at least one-half of the time. Multifocal breast cancer is more aggressive, 5) Bilateral breast cancer appears to have a very favorable prognosis, especially when non-simultaneous.