Citrulline in amniotic fluid and the prenatal diagnosis of citrullinemia

We report relatively high citrulline concentration in amniotic fluid of a citrullinemic fetus suggesting that prenatal detection of this condition could be done on this basis in conjunction with a direct or an indirect determination of argininosuccinate synthetase activity in amniotic fluid cells.     

Haithabu — Entdeckung neuer Funde durch hochauflösende kleinseismische Messungen

A high-precision seismic reflection method has been developed for investigating archeological objects which are hidden in a mud-layer of the Haddebyer Noor, a lake in front of the old Viking settlement Haithabu near Schleswig. Wooden and metallic objects larger than about 30 cm could be detected and mapped. Some of the mapped objects have been rescued by diving operations. Others, like wooden harbour constructions of unexpectedly large dimensions, and a large (second) shipwrack were left conserved in the mud. All finds provide a new picture of this old Viking settlement showing that its inhabitants had a far higher stage of development than hitherto suspected.     

More news about quarks

The “constituents” quarks and leptons of matter (with rest-mass) are compared with the historical development of “elements” in chemistry. If unsaturated quarks induce high (and at the moment unpredictable) rest-masses above l0GeV, we have a new view of nuclei comprising (2Z + N) u-quarks and (Z +2N) d-quarks in their low-energy states, without any reference to protons and neutrons as permanent building-blocks. Recent studies of quarks and possible rishons (sub-quarks) and technicolour hadrons are reviewed, and the rôle of identity and cardinality in quantum mechanics analyzed.     

Morphogene substanzen ausHydra

We use hydra as a model system to understand how growth and differentiation and, as a consequence of this, pattern formation are controlled at the molecular level. We have found that four substances control head and foot formation in hydra: an activator and an inhibitor of head formation and an activator and an inhibitor of foot formation. The two activators are peptides with molecular weights around 1000 daltons, the inhibitors are smaller in molecular weight (<500), have an overall positive charge and do not contain peptide bonds. In normal animals all four substances are present and most likely produced by nerve cells. We hope to understand how these substances act and interact to create the spatial and temporal pattern of growth and differentiation typical for hydra.     

The use of amniotic fluid AFP action limits in diagnosing open neural tube defects

An analysis is made of alphafetoprotein (AFP) concentrations in 3630 amniotic fluids submitted for prospective prenatal diagnoses over a 7-year period. There were 89 cases of anencephaly, 74 of open spina bifida and 3467 with normal singleton outcomes. The AFP data were expressed in both standard deviations above the mean and multiples of the normal median for individual weeks of gestation. False positive and false negative rates were comparable in the two systems at selected cut-offs. It is concluded that either system may be used in setting action limits for the primary distinction of unaffected pregnancies from those in which an open neural tube defect is present.     

Technical and theoretical considerations in the HLA typing of amniotic fluid cells for prenatal diagnosis and paternity testing

HLA typing of amniotic fluid cells has been used for the prenatal diagnosis of the HLA linked diseases congenital adrenal hyperplasia (21-OH-deficiency (21-OH-def) type) and complement C4 deficiency and it has also been used for the prenatal de termination of paternity. There are, however, technical difficulties in this test associated with the weak expression of some B locus antigens on amniotic fluid cells, and theoretical difficulties related to associations between particular HLA antigens and the 21-OH-def allele. Since certain HLA-B locus antigens are found in significantly increased frequencies among patients with 21-OH-def, there is a relatively high incidence of HLA-B homozygosity among the patients and over 40 percent of the parents of these patients share one or more HLA-B locus antigens. Results of some prenatal HLA typing tests may thus be difficult to interpret, and supplementary tests should be used whenever possible. HLA typing of amniotic cells is, however, the only available procedure for prenatal diagnosis of C4 deficiency and it is the best available procedure for prenatal determination of paternity. A modification of our original procedure allows HLA typing to be performed with increased numbers of HLA typing sera, and sera with optimum reactivity for amniotic fluid cells have now been selected for the definition of most of the more commonly expressed HLA antigens. Although amniotic fluid cells do not express DR antigens, amniotic fluid cells can be typed for the HLA-linked marker glyoxalase I (GLO) and this may be the informative for prenatal diagnosis in some cases.