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Biomedical subjects

D W Slingerland

Publications and source records attributed to D W Slingerland.

12 recordsLinked to original sources
PubMed1998

Food-bound B12 absorption and serum total homocysteine in patients with low serum B12 levels.

This study was undertaken to determine whether measurements of serum total homocysteine (Hcys) and bound B12 absorption are useful in determining which patients with low- or low-normal levels of serum B12 are B12 deficient. In 40 patients with low or borderline serum levels of B12, food-bound B12 absorptions were determined using a body counter in an iron room, and were related to serum total Hcys levels. Food-bound B12 absorption was decreased in 16 patients and in an additional four, absorption of the free vitamin was also decreased. Homocysteine levels were elevated in four of the 16; in three of the four who had both decreased bound and free B12 absorptions, Hcys was elevated. If elevation of the Hcys level indicates tissue deficiency of B12, the 75% incidence of normal levels of Hcys in these patients with low food-bound B12 absorptions suggests the existence of a cohort of patients who may be at risk to develop, but have not yet developed, B12 deficiency. Only long term follow-up will reveal how many ultimately will become B12 deficient.

Adult↗
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

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↗
PubMed1984

The utility of serum gastrin levels in assessing the significance of low serum B12 levels.

Elevated levels of serum gastrin as a consequence of gastric achlorhydria are characteristic of clinical pernicious anemia. In a largely male hospitalized population with an average age of 64 years, 7.7% had low levels of serum B12 (less than 170 pg/mL); only 2.5% of these had frank pernicious anemia. In an attempt to separate a subgroup with low levels of serum B12 in whom pernicious anemia may later develop, their serum gastrin levels were determined. Twenty-two percent had high values and, of these, 70% had low B12 absorptions. In patients with low serum B12 levels, serum gastrin assays may be useful in determining those in whom clinical pernicious anemia seems likely to develop.

Anemia, Pernicious↗
PubMed1983

Correction of attenuation in whole-body determination of Co-57 B12 absorption: concise communication.

The use of Co-57-labeled B12 for whole-body measurement of B12 uptake in humans has the advantage over Co-58 of easy commercial availability and lower cumulative radiation to the liver, but the disadvantage of significant attenuation. Methods devised to correct for the attenuation have used inaccurate early 100% counts. A method is described here that uses a liver phantom, containing a dissolved Co-57 B12 capsule, in a water tank. The ratios of upper to lower detector counts is related to total counts; it varies at different depths in the tank, and with the overall tank depth that is selected to accord with measured body habitus. The ratio of detector counts in the final patient count is used to read off the appropriate 100% total count. With this technique there is a clear discrimination between normal patients and those with pernicious anemia.

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↗
PubMed1976

Thyroid suppression tests during drug treatment of hyperthyroidism.

In fifteen hyperthyroid patients treated for 5 or more consecutive years with propylthiouracil four or more yearly prognostic 'suppression' tests (Cassidy & VanderLaan, 1960) were done. In nine of the fifteen patients there was a progressive diminution over a period of 3-6 years in the values of these suppressed uptakes to 20% or below. Eight of these nine patients have remained euthyroid off therapy for 1-8 years (average 3-1 years). None have become hypothyroid. The data suggest a gradual continuing change in thyroid function over the course of years in some hyperthyroid patients on antithyroid therapy. This may be a long-term effect of the drug and may have prognostic significance.

Adult↗