ABSTRACT
Eight radiochemical methods for the assay of vitamin B12 in serum were compared with the microbiological assay with Lactobacillus leichmannii ATCC 7830 using 198 individual sera of patients. There was a good agreement between the results of most samples with some kits and the microbiological assay. However, especially in the sera of vitamin B12-deficient patients large discrepancies between the results could occur. These variations were due to both the kits used and the performance of the assays in different laboratories. A sufficient number of non-pooled sera of vitamin B12-deficient patients should be included in investigations to validate radiochemical methods.
Subject(s)
Biological Assay , Radioisotopes , Reagent Kits, Diagnostic/standards , Vitamin B 12/blood , Humans , Lactobacillus , Methods , Microchemistry , Vitamin B 12 Deficiency/bloodSubject(s)
Cellulose/analogs & derivatives , DEAE-Cellulose/analogs & derivatives , Heparin/metabolism , Absorption , Blood Coagulation Tests , DEAE-Cellulose/adverse effects , DEAE-Cellulose/pharmacology , Hexadimethrine Bromide/pharmacology , Humans , Partial Thromboplastin Time , Prothrombin TimeABSTRACT
HCG and beta-HCG were determined in umbilical arterial and venous blood immediately after spontaneous term delivery. HCG and beta-HCG are present in higher concentrations in arterial than in venous umbilical cord blood. The data are consistent with the hypothesis that HCG and beta-HCG are produced in the fetal compartment of the human fetoplacental unit, with a larger contribution of the female fetus as compared with the male.
Subject(s)
Chorionic Gonadotropin/blood , Maternal-Fetal Exchange , Peptide Fragments/blood , Chorionic Gonadotropin, beta Subunit, Human , Female , Fetal Blood/metabolism , Humans , Infant, Newborn , PregnancySubject(s)
Blood Coagulation Tests/methods , Heparin/blood , Thromboplastin , Adult , Aged , Blood Coagulation/drug effects , Heparin/pharmacology , Hexadimethrine Bromide/pharmacology , Humans , Indicators and Reagents , Male , Middle Aged , Osmolar Concentration , Sulfur Radioisotopes , Time FactorsABSTRACT
Lactating Texel ewes are hyperprolactinemic. Hyperprolactinemia persists for at least the first 50 h after weaning, when the udder is swollen and tender. Oral administration of bromocriptine lowers hyperprolactinemia dramatically within 4 h, correlated with 'shrinking' of the udder. During lowering of hyperprolactinemia there is no immediate increase in LH.
Subject(s)
Lactation/physiology , Ovulation , Prolactin/metabolism , Animals , Bromocriptine/pharmacology , Female , Humans , Models, Biological , Pregnancy , SheepABSTRACT
Six commercially available reagents for the determination of the activated partial thromboplastin time have been evaluated and compared with respect to their sensitivity to the coagulation factors VIII, IX and XI and to their response to heparin. Some variation was observed among the reagents regarding their sensitivity to factor XI and even greater differences were obtained with factors VIII and IX. It was also clear that none of the reagents was sensitive to the same extent to the factors tested. The sensitivity to heparin shows considerable variation, in terms of time as well as mode of response to increasing heparin levels. In four reagents this response is linear, it is logarithmic in one and the remaining one is yet again different. It seems unlikely that any standardization of the APTT determination is at present possible with the reagents studied.
