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Biomedical subjects

B A Burrows

Publications and source records attributed to B A Burrows.

16 recordsLinked to original sources
PubMed1992

Bound vitamin B12 absorption in patients with low serum B12 levels.

In many patients with low serum levels of vitamin B12, the absorption of the free vitamin has been normal. The present study, using a total body counter 57CoB12 absorption method that clearly separated those with intrinsic factor deficiency from controls, found that of 94 patients with low B12 levels and intact stomachs in whom the absorption of free and bound B12 was determined, 44 (47%) had normal absorption of both. However, 20 of the 94 (21%) with normal absorption of free B12 had low absorption of bound B12. The remainder (32%) had low absorption of both free and bound B12. All patients with high serum gastrin levels had low bound B12 absorption, but so did 21% of those patients with normal serum gastrin levels.

Cobalt Radioisotopes↗
PubMed1989

Further studies on the use of serum gastrin levels in assessing the significance of low serum B12 levels.

The reported incidence of low serum vitamin B12 levels in patients ranges from 4% to 8%. In only a small percentage can this be ascribed to readily diagnosed pernicious anemia, malabsorption syndrome, or to gastrointestinal surgery. This leaves a number of patients in whom the meaning of the low serum B12 is not immediately apparent. In 71 patients with intact gastrointestinal tracts, hematological indices did not adequately separate patients with decreased absorption of unbound B12 from those with normal absorption. A low absorption of B12, either unbound or food-bound, was found, however, when the level of serum gastrin was elevated. In contrast, a normal absorption of unbound B12 was likely (95% of 44 patients) when the serum gastrin was normal.

Absorption↗
PubMed1985

Effects of dieting and exercise on lean body mass, oxygen uptake, and strength.

The effects of exercise on lean body mass (LBM), fat mass (FM), maximal oxygen uptake (VO2max), and quadriceps (QD) strength were studied in 72 male, mildly obese (X = 38% fat) subjects (X age, 43.5 yr) randomly assigned to one of eight treatments arranged in a 2 X 4 factorial plan with exercise (EX) and non-exercise (NE) and four diets as the two factors. Exercise consisted of a 3 d/wk, 8-wk aerobics program (70-85% maximum heart rate) accompanied by a calisthenics program. LBM was determined by whole body potassium (40K), FM by subtracting LBM from total body weight, VO2max using the Wilmore-Costill method, and QD strength with the Cybex II system. Weight loss of the combined EX (11.8 +/- 0.6 kg) (X +/- SE) and NE (9.2 +/- 0.3 kg) groups was not statistically different. LBM of the EX group was unchanged (from 63.1 +/- 1.9 to 62.5 +/- 2.1 kg), whereas in the NE group it was reduced from 62.6 +/- 1.1 to 59.3 +/- 1.2 kg (P less than 0.001) accounting for 36% of total weight loss. FM loss was greater for the EX group (11.2 +/- 1.5 kg) when compared to the NE (5.2 +/- 1.6 kg) group (P less than 0.001). The EX group exhibited an increase in VO2max from 2.9 +/- 0.3 to 3.4 +/- 0.2 1 X min-1 (P less than 0.001), whereas the NE group was unchanged (3.0 +/- 0.3 to 2.9 +/- 0.4 1 X min-1 (NS].(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1985

Measurement of total-body cobalt-57 vitamin B12 absorption with a gamma camera.

Previously described techniques for the measurement of the absorption of [57Co]vitamin B12 by total-body counting have required an iron room equipped with scanning or multiple detectors. The present study uses simplifying modifications which make the technique more available and include the use of static geometry, the measurement of body thickness to correct for attenuation, a simple formula to convert the capsule-in-air count to a 100% absorption count, and finally the use of an adequately shielded gamma camera obviating the need of an iron room.

Absorption↗
PubMed1979

Long-term antithyroid treatment in hyperthyroidism.

The major drawback to treatment of hyperthyroidism with antithyroid compounds is the reported low rate of remission. Eighty patients have been given long-term (at least one year; average, 4.4 years; range, one to 14 years) continuous treatment with a remission rate of 76% and an average follow-up of 7.8 years (one to 21 years). The prognostic test of suppressed uptake by the thyroid of less than 20% was about 75% accurate in predicting continuing remission when treatment was stopped. Of those in remission, 14 (23%) were treated for one year, 35 (57%) for one to five years, and 12 (20%) for more than five years. Mild reactions occurred in five (6%), hypothyroidism in two (3%). An antithyroid drug is safe and effective therapy for hyperthyroidism.

Adult↗
PubMed1978

Sensitivity and specificity of radioisotope renography in renovascular hypertension.

Effective drug therapy for hypertension modifies the urgency of establishing a diagnosis of renal arterial stenosis. The cost of establishing a diagnosis must be considered with other factors in determining the usefulness of renography in renovascular hypertension. Recently published studies estimate the cost effectiveness of this procedure based on some data from a cooperative study of renal vascular hypertension. The small but costly incidence of false positives contributes significantly to the total cost of patient screening. Careful attention to technical details that are presented here could reduce false positives without sacrificing the true positives. However, even with increased specificity economic considerations would indicate limiting a screening program to younger patients or those in whom a drug regimen is unsuccessful.

False Positive Reactions↗
PubMed1975

Measures of clinical efficacy. Cost-effectiveness calculations in the diagnosis and treatment of hypertensive renovascular disease.

The sensitivity and specificity of the hypertensive intravenous pyelogram and the iodohippuran renogram have been determined for the diagnosis of renovascular disease, and cost-effectiveness calculations have been made for the diagnosis and surgical treatment of patients with renovascular hypertension. When the intravenous pyelogram alone is used to screen representative hypertensive population, 78 per cent of patients with renovascular disease are located, but at the same time an equal number of patients without renovascular diasease have abnormal pyelograms. The renogram, on the other hand, is associated with varying true-positive and false-positive ratios. These data can be plotted in the form of a receiver-operating-characteristic curve. The cost of finding a patient with renovascular disease is about $2,000, and that of a surgical cure is about $20,000. The number of deaths for 100 surgical cures is approximately 15. The dollar cost of screening and treating the total American renovascular hypertensive population is of the order of 10 to 13 billion dollars.

Bayes Theorem↗