Cystic fibrosis carrier screening in two New South Wales country towns.

OBJECTIVE: To assess the feasibility of offering community testing for carrier status of delta F508, a gene mutation associated with cystic fibrosis (CF). DESIGN: Prospective pilot survey. SETTING: General practice, the two main high schools and workplaces in the country towns of Young and Harden (combined population, 14,940; with 7707 people aged 16-55 years) in New South Wales (NSW). PARTICIPANTS: Individuals aged 16 years and over. MAIN OUTCOME MEASURES: Number of delta F508 carriers, test uptake rates, mode of learning about the testing, motivation for testing, retention of knowledge about CF, and test results and emotional effects of knowledge about carrier status. RESULTS: We tested 610 people (8% of the population aged 16-55 years) and identified 47 carriers (20% of the expected number in the 7707 people aged 16-55 years). Testing in schools had the highest uptake. Retention of knowledge was high; all delta F508-positive individuals recalled their carrier status accurately. Anxiety was transient among carriers; over 90% of all respondents felt they had made the right decision to be tested. CONCLUSIONS: We recommend community testing for carrier detection and suggest targeting those with a family history of CF and girls aged over 16 in high schools.

Measurement of the self-diffusion coefficient of water as a function of position in wheat grain using nuclear magnetic resonance imaging.

A pulsed field gradient spin echo sequence has been incorporated in a nuclear magnetic resonance (NMR) imaging experiment to provide an image contrast dependent on local molecular self-diffusion. The consequent image attenuation is shown to exhibit a dependence on applied magnetic field gradient consistent with the Stejskal-Tanner relationship. The method used represents a novel extension of microscopic imaging and demonstrates the possibility of measuring localized motion.Water self-diffusion rates normal to the transverse 1.3-mm section of a wheat grain have been measured in structural features at 150-mum resolution. The results are consistent with averaged measurements in the bulk grain obtained by other methods while local differences in water mobility correlate with differences in physiological function.

The levels of soluble nucleotides in wheat aleurone tissue.

The content of soluble nucleotides in aleurone layers isolated from mature wheat (Triticum aestivum var. Olympic) grain was investigated. The most abundant nucleotides were adenosine triphosphate, uridine triphosphate, and uridine diphosphoglucose. Smaller amounts of guanosine triphosphate, cytidine triphosphate, adenosine diphosphate, and nicotinamide adenine dinucleotide were also identified. The levels of some of these nucleotides were increased after incubation of the tissue under certain conditions.Nucleotide levels were measured at intervals during incubation of aleurone layers in water. The changes observed are discussed in relation to a response by the tissue to wounding.

The metabolism of soluble nucleotides in wheat aleurone layers treated with gibberellic Acid.

The metabolism of soluble nucleotides was investigated in wheat (Triticum aestivum var. Olympic) aleurone layers treated with gibberellic acid. Whereas nucleotide levels were relatively unaffected by the treatment, a transient increase was observed in the incorporation of (32)P. The effect was maximal 30 to 60 minutes after gibberellic acid was administered, and by 180 minutes incorporation was lower than in the control. The greatest changes were detected in the nucleoside triphosphates, particularly in cytidine triphosphate. The findings are discussed in relation to the mode of action of gibberellic acid.

The composition of soluble nucleotides in the developing wheat grain.

A method is described for the extraction and measurement of soluble nucleotides from wheat grain. Nucleotides were separated (80-90% recovery) by paper chromatography followed by electrophoresis. The nucleotides extracted were ADP-glucose, ATP, ADP, AMP, and NAD; UDP-glucose, UTP, UDP, and UMP with smaller quantities of cytidine nucleotides.In grain sampled at 20 days after anthesis, 70% of the UDP-glucose was present in the endosperm and the remainder in the testa and pericarp; 90% of the ADP-glucose was found in the endosperm. Of the four uridine nucleotides UDP-glucose was the most plentiful and the level rose from about 330 mmumoles per g fresh weight on the third day after flowering to 430 mmumoles/g on day 12 and then fell steadily to about 140 mmumoles/g just before complete ripening. Levels of 250 mmumoles and 200 mmumoles per g fresh weight were recorded for UTP and UDP on day 12. Thereafter the content of UTP fell relatively more rapidly than either UDP or UDP-glucose.ATP was the most abundant adenine nucleotide and from 7 days after anthesis to day 40 the quantity per g fresh weight fell from about 350 mmumoles to 100 mmumoles. The level of ADP-glucose rose to a maximum of 140 mmumoles/g between days 15 and 21 and then fell slightly towards maturity while ADP varied between 50 and 80 mmumoles/g. On day 20, coinciding with the maximum rate of starch synthesis in the endosperm, the concentration of ADP-glucose in this tissue was about 0.3 mm, and that of UDP-glucose 0.7 mm.The relationship of these results to the mechanism of transfer of hexose units from sucrose to starch is discussed.