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K O'Leary

Publications and source records attributed to K O'Leary.

17 recordsLinked to original sources
PubMed2002

Plasma, liver and kidney folate and plasma homocysteine concentrations are poor response variables at very low dietary folate intakes, in a folate depletion/repletion rat model.

Folate depletion/repletion rat models are popular protocols for assessing the bioavailability of folate. Much of the early work carried out on folate bioavailability concentrated on foods naturally high in folate. However, foods low in folate often contribute significantly to folate intake because of their high consumption in the general population. Therefore, the assessment of the bioavailability of foods low in folate is essential to properly estimate folate intake. The present study investigated plasma, liver and kidney folate and plasma homocysteine concentrations as appropriate response variables for measuring folate bioavailability in the rat at very low dietary folate intakes. One hundred and one weanling male rats (Wistar strain) were fed a folate-deficient diet containing 1% succinyl sulfathiazole for 28 d. Following depletion, six rats were randomly assigned to each of 16 repletion diets containing folic acid, fortified white bread, unfortified wholemeal bread or unfortified rye bread calculated to provide 6.25, 12.5, 18.75 and 25 micrograms folate/kg of each diet. After a further 28 d, plasma, liver and kidney folate concentrations were determined by microbiological assay. Plasma homocysteine was measured by HPLC as a functional indicator of folate status. Only a weak correlation was found between the response variables measured and dietary folate intake, indicating that this folate depletion/repletion rat model is not suitable for testing the response of rats fed diets containing very low levels of folate.

Animals↗
PubMed2001

Effects of preparation and cooking of folic acid-fortified foods on the availability of folic acid in a folate depletion/repletion rat model.

The practice of food fortification with folic acid offers the potential to increase the folate intake of the general population. To fully exploit the potential of fortification for raising folate nutriture, appropriate food vehicles need to be selected. Selection should involve determination of the availability of folic acid as affected by characteristics of the carrier food, food matrix, food preparation, and cooking. The present study investigated the effects of preparation and cooking of a range of folic acid-fortified foods on the folate status of folate-deficient rats. Fifty-six weanling male rats (Wistar strain) were fed a folate-deficient diet containing 1% succinyl sulfathiazole for 28 days. Following depletion, six rats were randomly assigned to each of eight repletion diets containing cooked or uncooked meringue mix, quick bread mix, brownie mix, or pizza base mix. The test foods were fortified with 1400 microg of folic acid/kg of food and incorporated as 19% of the repletion diets. Each of the first four groups was pair-fed a diet containing a cooked fortified food with another group fed the corresponding uncooked fortified food. After a further 28 days, plasma, liver, and kidney folate concentrations were determined by microbiological assay. Mean plasma and liver folate concentrations of rats fed diets containing cooked fortified foods were similar to those of rats fed uncooked fortified foods. Preparation and cooking did not affect the availability of folic acid from the selected cereal-based convenience foods in this rat model system, suggesting that these foods are appropriate vehicles for fortification with folic acid.

Animals↗
PubMed2001

Influence of folic acid-fortified foods on folate status in a folate depletion-repletion rat model.

An increasing number of foods fortified with varying levels of folic acid are appearing in the market place, targeted either at the general population or at specific consumer groups. Although it is assumed that the folate in these products should be highly bioavailable, there is a need to carry out studies to ascertain that this is, in fact, the case. The present study investigated the ability of selected folic acid-fortified foods (targeted at different types of consumer) to increase the folate status of folate-deficient rats. Forty-two weanling male rats (Wistar strain) were fed a folate-deficient diet containing 1 % succinyl sulfathiazole (w/w) for 28 d. Following depletion, seven rats were randomly assigned to each of five repletion diets containing folic acid, Complan, Slim Fast, Opti-Fuel2 or Cola Coa calculated to provide 200 microg folate/kg of each diet. Calculations were based on folate information from the product labels. After a further 28 d, plasma, liver and kidney folate concentrations were determined by microbiological assay. Plasma homocysteine was measured by HPLC as a functional indicator of folate status. The folate content of the foods was measured by tri-enzyme extraction followed by microbiological assay. Our analyses suggest that there may be considerable inaccuracies on the part of the manufacturers in relation to the folate declarations on the product labels. Despite this, the four foods evaluated were highly effective in elevating plasma, liver and kidney folate and lowering plasma homocysteine concentrations in rats. These results lend support to the policy of food fortification with folic acid as a means of raising the folate status of the population, and in particular to the fortification of specific foods which may target areas of the population where increased folate status is most needed.

3T3 Cells↗
PubMed1998

Evolution of a state occupational lead exposure registry: 1986-1996.

In the first 11 full years of operation (January 1, 1986, through December 31, 1996) of an adult lead registry in New Jersey, 23,456 reports of occupational lead toxicity (blood lead level > or = 1.21 mumol/L) in 4,011 workers, involving 496 workplaces, were received. The majority of the reports and workers were from the manufacturing and construction industries. Over the 11 years, the annual numbers of reports and workers declined, although the annual numbers of involved workplaces remained stable, as did the number of newly identified workers and workplaces. The decline occurred primarily in the manufacturing industry; the construction industry experienced an increase in reports and reported workers. For all years combined, 36% of reported workers had at least one blood lead level equal to or greater than 1.93 mumol/L, although in the most recent years the percentage dropped overall and in both the manufacturing and construction industries.

Adult↗
PubMed1993

The garden room.

Explore the source record for details and available documents.

Female↗
PubMed1987

Occupational asthma caused by himic anhydride.

Acid anhydride compounds are reactive chemicals that have been previously associated with immunoglobulin E (IgE) mediated occupational asthma. Twenty workers with exposure to himic anhydride powder used for the manufacture of a synthetic flame retardant were questioned about respiratory symptoms. The study was initiated after one individual from the plant developed asthma. A test for serum-specific IgE to human serum albumin conjugates of himic anhydride, phthalic anhydride, hexahydrophthalic anhydride and trimellitic anhydride was performed for seven workers with respiratory symptoms associated with himic anhydride exposure. Three of the seven symptomatic workers who reported wheezing at work exhibited elevated specific IgE to two or more acid anhydride-human serum albumin conjugates. Radioallergosorbent inhibition studies performed with sera containing high levels of himic anhydride-human serum albumin specific IgE from a symptomatic worker demonstrated cross-allergenicity between himic anhydride-human serum albumin and hexahydrophthalic anhydride-human serum albumin allergenic determinants. This study demonstrated that himic anhydride can elicit IgE-mediated sensitization in the workplace.

Adult↗
PubMed1984

Elevated levels of carbon monoxide in the patient compartment of ambulances.

Six hundred and ninety New Jersey ambulances were monitored for carbon monoxide (CO); 27 per cent had CO levels of 10 ppm or more greater than ambient air in the breathing zone of the patient. Twenty-nine of these ambulances had levels of at least 35 ppm greater than ambient air. Results indicate that a CO exposure problem exists in ambulances.

Air Pollutants↗
PubMed1981

Non-invasive magnetopneumographic determination of lung dust loads in steel arc welders.

Magnetopneumography was used to measure non-invasively the concentration of the ferrimagnetic fraction of retained welding fume in the thoraces of steel arc welders. This was done by measuring the remanent magnetic fields due to ferrimagnetic particles. The 11 welders studied had concentrations of thoracic ferrimagnetic mineral several orders of magnitude greater than three machinists, 16 former asbestos insulators and 24 control subjects. These concentrations correlated well with total years welding (p less than 0.01) and radiographic evidence of small rounded densities (p less than 0.05), but not with smoking history. There was a higher concentration of ferrimagnetic mineral over the hilar regions. Magnetopneumography offers a non-invasive indicator of the accumulation of welding fume in the thorax.

Adult↗