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Biomedical subjects

J Lyngbye

Publications and source records attributed to J Lyngbye.

49 records · Page 3Linked to original sources
PubMed1977

Folate binding by human milk protein.

Human whey was subjected to gel chromatography. Two folate binding protein fractions wer eluted: a major one (Mr congruent to 30,000) and a minor one (Mr greater than 200,000). The former folate binding fraction (FB) could be isolated from whey by means of ion exchange chromatography. Equilibrium dialysis experiments with whey and isolated FB indicated the existence of cooperatively interacting sites in folate binding. The folate analogue methotrexate inhibited folate binding. Inhibition was apparently of a competitive type since methotrexate did not reduce maximum binding capacity. Cooperativity was lost in the presence of methotrexate. Binding affinity was inversely proportional to the concentration of FB suggesting involvement of a polymerizing protein system in binding. None of the other fractions eluted on the ion exchange column could bind folate.

Binding Sites↗
PubMed1976

Method for monitoring plasma progesterone concentrations in pregnancy.

We present a time-series model for monitoring concentrations in plasma of hormones produced in the placenta, progesterone being chosen as an example. The model, which is based on the assumption that variations in plasma progesterone concentration in pregnant subjects mainly reflect variations in the growth rate of the placenta, was applied to eight series of progesterone values measured during pregnancy in eight subjects. In the model, which was found to fit the data, it is assumed that progesterone concentration is proportional to the size of the placenta and that the growth rate of the placenta varies at random, with a mean value alpha. The variation of alpha was of the same magnitude among and within the subjects. If the average of many subjects alpha values is used, a single subject may be used as her own reference, based on only one previous observation. When two observations are available, an individual's own alpha value may be estimated and used for the prediction. The predictive power of the new method was found to be far superior to the conventional method in which a single sample reference material is used. Furthermore, one need not know the gestational age in order to use the method.

Abortion, Spontaneous↗
PubMed1975

Diagnostic value of routine liver tests.

In 131 patients on a medical service and 97 patients on a surgical service, in whom a diagnosis of hepatobiliary disease was verified in the hospital, the diagnostic value of routine liver tests performed soon after admission was evaluated by stepwise discriminant analysis. By measurements of alanine aminotransferase, alkaline phosphatases, gamma globulin, prothrombin time, bilirubin, and albumin, half of the medical patients were correctly classified into one of seven diagnostic categories. Aminotransferase contributed most to the classification, being twice as effective as random allocation. Decreasing the number of diagnostic categories to three (hepatitis, fatty liver, and chronic liver disease) increased the frequency of correct allocation to 80%. The allocation of all the patients to seven medical and four surgical diagnostic categories by means of four tests (aminotransferase, alkaline phosphatases, prothrombin time, and bilirubin) was significantly improved by each step with a misclassification rate of 55% when all tests were used. A reduction of the diagnostic groups to five (hepatitis, fatty liver, chronic liver disease, duct obstruction and tumor) increased the frequency of correct allocation to 63%. The analysis demonstrates the limited diagnostic effectiveness of routine liver tests when used alone. The absolute discrimination values depend on the a priori frequencies of the diagnostic groups investigated, and therefore may vary from time to time and from place to place.

Alanine Transaminase↗