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Biomedical subjects

D Teichler-Zallen

Publications and source records attributed to D Teichler-Zallen.

5 recordsLinked to original sources
PubMed1980

Amniotic fluid secretor typing: validation for use in prenatal prediction of myotonic dystrophy.

Use of the well-established linkage of the secretor locus (Se) to the myotonic dystrophy locus (Dm) as an indirect means for prenatal prediction of myotonic dystrophy requires that the phenotypic expression of the fetal secretor locus be accurately and reliably assessed in amniotic fluid. Secretor status determinations on 89 amniotic fluids obtained by second trimester amniocentesis were compared with results of postnatal secretor typing of saliva samples collected from the resulting 89 offspring. The secretor types of the paired amniotic fluid-saliva samples were in agreement in all cases. The only unusual typing result was on an amniotic fluid from a blood group O secretor fetus in which the level of soluble H antigen was estimated to be about one-third that observed for other H secretors. Though it is possible that rare secretor fetuses with very low titers of soluble antigen at the time of amniocentesis could be mistyped as non-secretors, our results indicate that such an erroneous typing result would only occur in about 1-2% of all amniotic fluids tested. Constructed mixtures of 10% heparinized blood in non-secretor amniotic fluid or of 10% serum in amniotic fluid derived from secretor fetuses did not introduce sufficient levels of soluble antigen or of antibody to interfere with accurate secretor typing, thus providing reassurance that maternal and/or fetal blood contamination of amniotic fluid does not compromise accuracy of fetal secretor typing. This study documents the accuracy and reliability of amniotic fluid secretor typing for prenatal prediction of fetal risk for later development of myotonic muscular dystrophy.

ABO Blood-Group System↗
PubMed1969

The effect of manganese on chloroplast structure and photosynthetic ability of Chlamydomonas reinhardi.

Manganese deficiency was induced in mixotrophically-grown cultures of the green alga Chlamydomonas reinhardi and the effects of this deficiency on photosynthetic activity and cell structure were investigated. Manganese-deficient cells are unable to carry out, at normal rates, photosynthetic reactions involving system II of the photosynthetic electron transport chain. Reactions requiring only system I are not inhibited. Normal system II activity returns within 2 hr in the light following addition of manganous ions to deficient cells.Significant structural alterations for deficient cells were observed in the chloroplast, in the arrangement of discs into stacks. Stacking distributions for normal, deficient, and recovered cells were quantitatively characterized and compared by the introduction of an experimentally-defined distribution function and its attendant parameters. The results provide evidence for a role for manganese in maintaining chloroplast structure.

Chloroplasts↗
PubMed1967

An Electron Spin Resonance Study of Manganese in Wild-Type and Mutant Strains of Chlamydomonas reinhardi.

Changes in the intensity of the electron spin resonance signal of divalent manganese were found to occur in suspensions of wild-type Chlamydomonas reinhardi. The observed manganese signal decreased in the light and increased in the dark. Through the use of a continuous-flow system it was possible to determine that the manganous ions responsible for the observed signal were localized solely in the medium. Changes in the signal intensity associated with wild-type cells were independent of the ability of fragments prepared from these cells to perform the Hill reaction with 2,6-dichlorophenol-indophenol (DPIP) as the oxidant.The manganese signal changes were still evident, though smaller, in cell suspensions of wild-type cells treated with 3-(3,4-dichlorophenyl)-1, 1-dimethylurea, and in mutant strains unable to carry out the Hill reaction, ac-115 and ac-141.From these data it is concluded that the changes in intensity of the manganese resonance are not related to the function of manganese in photosynthesis but may reflect the capacity of cells for ion uptake in the light.

Journal Article↗