Biomedical subjects

D T Forman

Publications and source records attributed to D T Forman.

58 records · Page 4Linked to original sources

PubMedDate not supplied

Biochemical assessment of fetal lung maturity.

The relationship between the enzyme phosphatidate phosphohydrolase (PAPase) and lecithin/sphingomyelin (L/S) ratio in amniotic fluid was evaluated in normal human pregnancies and in several pregnancies complicated by Rh isoimmunization. An increase in PAPase activity in amniotic fluid appears to parallel the increase in L/S ratio after 33 weeks gestation in normal subjects. These data suggest that amniotic fluid PAPase may originate from the fetal lung and play a role in the regulation of the synthesis os lecithin. Its usefulness as an indicator of fetal lung development requires further correlation and confirmation.

Amniotic Fluid↗

PubMedDate not supplied

The measurement and interpretation of serum ferritin.

Determination of serum ferritin is an important means of assessing body iron stores. Trace amounts of ferritin normally present in serum are detectable by sensitive radioimmunoassay techniques or an enzyme immunoassay procedure. Ferritin normally accounts for no more than a very small fraction of the total iron in serum, but generally maintains a stable concentration that is proportional to the much larger pool of storage iron in tissues. The serum ferritin assay, in contrast to other measurements of iron status such as hemoglobin, serum iron and iron-binding capacity, can distinguish differences in iron stores within the physiological range. In iron deficiency anemia, the concentration is below 10 ng per ml. Increased concentrations (above 200 ng per ml) are found in conditions with increased iron stores. The information it provides is similar to that obtained from bone-marrow aspirates stained for iron. In contrast to the percent transferrin-saturation and concentration of erythrocyte protoporphyrin, ferritin concentrations become abnormal before exhaustion of mobilizable iron stores and before the onset of anemia. Serum ferritin also provides a practical means of assessing new programs of iron supplementation, since it reflects various degrees of iron deficiency and overload.

Anemia, Hypochromic↗

PubMedDate not supplied

Release of amino acids from fatty livers during organ harvest for transplantation.

Shortage of organ donors presents a perplexing problem in liver transplantation, and improved methods for evaluating the viability of organs prior to implantation are urgently needed. In the present study, the hypothesis was evaluated that grafts from fatty livers release more amino acids than non-fatty controls during organ harvest. Amino acids in graft rinse effluents at the time of harvest and after cold storage were measured by reverse-phase high performance liquid chromatography and compared with plasma aspartate aminotransferase (AST) levels and recipient survival. Twenty-four hours after transplantation of fatty livers, AST levels in recipient rats were increased more than two-fold compared to non-fatty controls (p < 0.01). Survival in the control group was 83 percent, whereas animals receiving fatty livers from ethanol-treated rats survived no longer than 7 days after transplantation (p < 0.05). The rate of release of amino acids from the liver explant was two-fold higher during the harvest procedure (0.5 h) than during the subsequent 23.5 hour cold storage period (435 +/- 70 vs. 186 +/- 14 nmol/ml/hr/g liver, p < 0.001). Further, in the early rinse effluent, amino acids were released about two-fold faster from fatty livers than from controls (p < 0.05). This study demonstrates that the release of amino acids from liver explants increases during the harvesting procedure and is about two-fold higher in fatty livers which fail after transplantation than in surviving controls. It is proposed that amino acid release from explants after organ harvest might serve as a useful marker to evaluate graft function prior to transplantation.

Amino Acids↗

PubMedDate not supplied

Drug interference in laboratory testing.

Characteristic problems in the interpretation data when a drug or its metabolite interferes with a laboratory procedure are reviewed. Various mechanisms of interference (physical, chemical, pharmacological and drug-drug interaction) are discussed. The role of a computerized drug-test interference file in assisting in the predication as well as interpretation of apparent test results is described.

Clinical Laboratory Techniques↗