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Biomedical subjects

L J Keating

Publications and source records attributed to L J Keating.

14 recordsLinked to original sources

The generality of individual differences in the estimation of size.

These two studies pursued the notion that there are individual differences of considerable generality in the extent to which individuals estimate the size of objects, including body image and physical objects such as a blank card. In the first study, 79 female undergraduate students estimated the width of their own bodies (head, shoulders, waist, and hips), the waist of a standard "real" person, the bodies of two life-size wooden figures, and three boxes. In the second study, 60 female undergraduate students estimated the width of their bodies, three boxes, and two blank cards. Errors in estimation, computed as the difference between estimate and true value divided by the true value, were obtained from all subjects. Correlations between body-image errors and all other errors in estimation were positive in both studies, except for one correlation of - .02. Factor analyses of the correlations between the error scores in each study indicated a substantial general factor, although some residual common variance remained. Results supported the proposition that individuals differ in a consistent fashion across a wide range of size-estimation situations.

Adult↗

Bioavailability of carbonyl iron: a randomized, double-blind study.

49 female blood donors with iron-deficiency anemia were treated with equal doses of iron either as carbonyl iron or ferrous sulfate in a randomized, double-blind fashion. The prevalence of side-effects was similar in the two groups. Mean values for hemoglobin concentration, mean corpuscular volume, corrected reticulocyte count, platelet count, serum iron, total iron-binding capacity, transferrin saturation or erythrocyte protoporphyrin did not differ significantly between the two groups throughout the study. After 16 weeks of therapy, the mean increase in hemoglobin iron was similar in both groups (p = 0.2). Estimates of net changes in total body iron suggested that the overall bioavailability of carbonyl iron was high, about 70% that of ferrous sulfate.

Adult↗

A study of confidential unit exclusion.

The effectiveness of the confidential unit exclusion (CUE) procedure recommended by the Food and Drug Administration has been questioned by the blood banking community. The purpose of this study was to determine whether donors were informing the blood center correctly regarding the disposition (transfuse or do not transfuse) of their donated blood. A letter explaining the confidential study and requesting permission to send the participant a questionnaire noting his or her self-exclusion choice was mailed to 230 donors who had chosen transfuse and 276 donors who had chosen do not transfuse. After consent was obtained, participants were sent a second packet and asked to indicate whether they had chosen correctly and, if not, to identify reasons for that incorrect choice. A seven-word terminology quiz made up of words from the CUE form was also enclosed. All participants who had chosen transfuse indicated that this was the correct choice. Approximately 50 percent of those who had chosen do not transfuse indicated that this was an incorrect choice; the most common reason was that "I was not paying attention." The most frequently misunderstood term was "confidential." Donors who chose do not transfuse had a significantly higher rate of error on the terminology quiz (p less than 0.01) than did those who chose transfuse.

Blood Donors↗

High-dose carbonyl iron for iron deficiency anemia: a randomized double-blind trial.

To determine if high doses of oral iron could shorten the duration of therapy necessary to treat Fe deficiency anemia, high-dose Fe 600 mg three times per day (given as nontoxic carbonyl Fe) was compared with standard ferrous sulfate 60 mg Fe++ three times per day in a randomized, double-blind, 3-wk trial involving 36 female blood donors with mild Fe deficiency anemia. In animal studies, both forms of Fe have similar bioavailability when administered in equal amounts. High-dose carbonyl Fe was well tolerated with gastrointestinal side effects similar those observed with standard FeSO4 therapy. The 10-fold larger amount of Fe resulted in a mean 1.5-fold increase in estimated Fe absorption. Both regimens corrected anemia but neither replenished storage Fe. These results suggest that the principal advantage to the use of carbonyl Fe would derive from its safety rather than from the large doses that can be given.

Adolescent↗

Carbonyl iron therapy for iron deficiency anemia.

To determine if elemental carbonyl iron powder is safe and effective therapy for iron deficiency anemia, 20 nonanemic and 32 anemic volunteers were studied. Single doses of 1,000 to 10,000 mg of carbonyl iron (15 to 150 times the 65 mg of iron in the usual dose of ferrous sulfate) were tolerated by nonanemic volunteers with no evidence of toxicity and only minor gastrointestinal side effects. Anemic volunteers (menstruating women who had previously donated blood) were treated with several regimens providing 1,000 to 3,000 mg of carbonyl iron daily in one to three doses for 8 to 28 days. After 12 weeks anemia was corrected in 29 of 32 patients, and serum ferritin was greater than 12 micrograms/L in 14. Hemoglobin regeneration proceeded at a rate similar to that described for therapy with oral iron salts and parenteral iron dextran. There was no evidence of hematologic, hepatic, or renal toxicity, but mild gastrointestinal side effects occurred in a majority of anemic volunteers. Carbonyl iron is an effective, inexpensive treatment for iron deficiency anemia, is accompanied by tolerable side effects and may have an advantage over therapy with iron salts by substantially reducing or eliminating the risk of iron poisoning in children.

Adult↗

Carbonyl iron for short-term supplementation in female blood donors.

A randomized, double-blind trial of iron replacement after repeated blood donation was conducted in 75 menstruating women; 51 completed the study. Volunteers were assigned randomly to one of three treatment groups: 1) carbonyl iron (nontoxic elemental iron powder), 600 mg; 2) ferrous sulfate, 300 mg (60 mg Fe++); or 3) placebo, each given three times daily for 1 week immediately after blood donation. Blood samples obtained initially and 56 days later were tested for hemoglobin, mean corpuscular volume (MCV), free erythrocyte protoporphyrin, serum ferritin, serum iron, total iron binding capacity (TIBC), and percent saturation of TIBC. The prevalence of gastrointestinal side effects was similar in both groups taking iron. At the end of the study there was no laboratory evidence of change in iron status in women who received carbonyl iron (n = 15). In those treated with ferrous sulfate (n = 17) the mean TIBC increased (p less than 0.001), and in the placebo group (n = 19) there were decreases in mean MCV (p less than 0.01), serum ferritin (p less than 0.001), and percent saturation (p = 0.027) with an increase in mean TIBC (p = 0.004). Carbonyl iron seems to be effective for short-term iron replacement in repeat blood donors and may have the advantage of decreased or absent risk of poisoning if accidentally ingested by children.

Blood Donors↗

Red blood cell mass in autologous and homologous blood units. Implications for risk/benefit assessment of autologous blood crossover and directed blood transfusion.

A prospective analysis of 300 consecutively collected homologous blood (HB) units from a regional blood center and an analysis of 188 consecutively collected autologous blood (AB) units from a community hospital was conducted. Analysis of the red blood cell (RBC) mass content of these blood units revealed that HB contained 13 percent more RBC than AB: 200 +/- 1.1 vs 177.1 +/- 1.1 mL, (m +/- SE), respectively (p less than 0.05). Of 174 AB units eligible for crossover by AABB criteria for RBC mass (greater than or equal to 154 mL), 35 (20%) were below the 95 percent confidence interval range for RBC mass of HB units collected; mean RBC mass of 300 HB units was 12 percent greater than that of 174 AB units (200.1 +/- 1.1 vs 178.9 +/- 0.9 mL, p less than 0.001) and 20 percent greater than that of the 35 AB units outside the 95 percent confidence interval (200.1 +/- 1.1 vs 161.2 +/- 0.5 mL, p less than 0.001). These findings indicate that an evaluation of the issues of AB crossover for HB transfusion should include a risk/benefit analysis of AB units with lower RBC mass. These findings also indicate that the proposed changes in AABB standards regarding directed donation (DD) should consider the reduced benefits of DD units with lower RBC mass in a risk/benefit analysis of this practice, and support retention of homologous donor standards for directed donors.

Blood Banks↗

Prevention of iron deficiency with carbonyl iron in female blood donors.

The effectiveness of elemental, nontoxic carbonyl iron in replacing iron lost at blood donation was examined. In a randomized double-blind design, 99 women, aged 18 to 40, were given placebo or low-dose carbonyl iron (100 mg orally) at bedtime for 56 days after phlebotomy. Compliance was equivalent for the two regimens. Mild side effects were slightly greater with carbonyl iron. At Day 56, estimated net iron absorption from therapy or diet, or both, was sufficient to replace iron in 85 percent of those receiving carbonyl iron but in only 29 percent of those taking placebo (p less than 0.001). The rates of deferral from repeat donation were 8 percent in the carbonyl iron group and 36 percent in the placebo group (p less than 0.01), and the positive predictive value of routine screening in identifying participants without iron deficiency was 83 versus 13 percent (p less than 0.01). It can be concluded that short-term carbonyl iron supplementation in female blood donors can replace the iron lost at phlebotomy, protect the women against iron deficiency, and enhance their ability to give blood.

Anemia, Hypochromic↗