THE DIAGNOSIS OF IRON DEFICIENCY BY ERYTHROCYTE PROTOPORPHYRIN AND SERUM FERRITIN ANALYSES

ABSTRACT. Free erythrocyte protoporphyrin (FEP) and serum ferritin have been determined in 57 healthy children and in 25 children with varying degrees of iron deficiency. FEP was found to be inversely correlated to the concentration of hemoglobin (r=-0.80) as well as to serum ferritin (r=-0.64). Elevated FEP was found in children with hemoglobin less than 12.5 g/dl, or serum ferritin less than 8 μg/l. In a group of apparently hematologically normal children between the age of 10–14 years (hemoglobin≥ 12.5 g/dl), a 2-month-trial of iron medication resulted in an increase in hemoglobin and ferritin, and a decrease in FEP, indicating suboptimal supply of iron for hemoglobin synthesis before iron medication. In a patient with iron deficiency (FEP 15.3 μmole/l, hemoglobin 5.2 g/dl), iron therapy was followed by a rapid fall in FEP before any changes in hemoglobin, serum iron transferrin saturation and ferritin could be detected. The rapid fall in FEP during start of treatment in iron deficiency makes FEP a sensitive biochemical parameter on iron homeostasis in iron deficiency anemia.     

Immunotoxicity Testing: An Economical Multiple-Assay Approach

Immunotoxicity Testing: An Economical Multiple-Assay Approach.EXON, J.H., KOLLER, L.D., TALCOTT, P.A., O'REILLY, C.A., ANDHENNINGSEN, G.M. (1986). Fundam Appl. Toxicol. 7, 387-397. Amodel for assessing immunotoxicologic effects of chemicals anddrugs was developed in the Sprague-Dawley rat whereby multipleconcomitant immunoassays were performed in a single animal.The multiple parameters of immunity assessed in each rat includedT cell-dependent IgG antibody production, delayed hypersensitivity,natural killer cell cytotox-icity, and production of three potentimmune regulating immunocytokines: macrophage-de-rived interleukin1 and prostaglandin E2, and lymphocyte-derived interleukin 2.Splenocyte and resident peritoneal macrophage numbers were alsoquantitated and spleen and thymus weights recorded. The sensitivityof this animal model was tested by treating rats with the immune-potentiatingdrugs, NPT 15392 (erythro-9-[2-hydroxy,3-nonyl]hypoxanthine)and avridine (N, N-dioctadecyl-N', N'-bis-[2-hydroxyethyl]propanediamine,or the immune-suppressive drugs, cyclophosphamide (N, N-bis[2-chloroethyl]tetrahydro-2H-1,3,2-oxazaphosphorin-2-amine-2-oxide)and dexamethasone. Rats treated with NPT 15392 or avridine generallyhad enhanced immune responses, while those treated with cyclophosphamideor dexamethasone had decreased immune responses. Differentialresponsiveness of various immunocyte populations within individualrats to different drugs, or to doses of the same drug, indicatesthe efficacy of measuring multiple responses within the sameanimal. The multiassay-single animal approach represents aneconomical, versatile, sensitive, and relatively comprehensiveparadigm for assessing immunotoxicologic/pharmacologic propertiesof chemicals and drugs. The approach is extremely economicalsince multiple immune responses are evaluated in each animal.The approach is versatile because it is amenable to incorporationof a variety of in vitro and in vivo assays and could be appliedto almost any species. The model is relatively comprehensivebecause major types of immune responses/immunocyte populationsand immunoregulatory pathways are tested. Finally, the modelis sensitive for detecting immunosuppression as well as immunoenhancement,as validated by the use of known immune response modifiers inthis Study.     

Influence of Different Conditioning Methods on Force and Fatigue Resistance in Chronically Stimulated Skeletal Muscles

A study was undertaken to compare different conditioning methods for the transformation of latissimus dorsi muscle into a fatigue resistant one for application in circulatory assist. In ten sheep four electrodes were sutured to the epineurium of the left thoracodorsal nerve for indirect electrical stimulation of the latissimus dorsi muscle. In six sheep a "carousel stimulation, " a special multichannel stimulation, in combination with a recently developed conditioning protocol was used for muscle conditioning ( multichannel method ). In four sheep, a conventional stimulation protocol using single channel stimulation was applied for transformation of the muscle (single channel method). The final experiments were carried out when fatigue resistance was obtained. The maximum tetanic forces at different preloads were determined and fatigue resistance was tested during 20 minutes of continuous stimulation. Both conditioning patterns led to fatigue-free chronic stimulation. Muscles conditioned by multichannel stimulation exhibited between 20% and 33% less force than the contralateral unconditioned muscles, whereas in the single channel group this loss was between 32% and 43%. Thus, the multichannel method revealed relatively superior in preserving muscle force for chronic stimulation.