Die Selbstdifferenzierungsfähigkeit und Induktionsfähigkeit medianer und Lateraler Teile der Rumpfmedullarplatte bei Urodelen

Ohne Zusammenfassung     

Die lichtabhängige Vakuolisation der Chloroplasten in Nikotinlösungen

Ohne ZusammenfassungDie vorliegende Arbeit wurde als Teil einer Dissertation am Botanischen Institut der Universität Münster (Westfalen) ausgeführt.Meinem hochverehrten Lehrer, Herrn Prof. Dr. S. Strugger, bin ich für die Überlassung des Arbeitsplatzes und für die ständige Förderung meiner Arbeit zu größtem Dank verpflichtet.     

THE METABOLISM OF TISSUE CULTURES : I. PRELIMINARY STUDIES ON CHICK EMBRYO

1. The metabolism of chick embryo tissues has been followed by analysis of the culture media after various periods of incubation in roller bottles. 2. The initial rate of glucose utilization is increased by increasing glucose in the medium from 100 to 500 mg. per cent. Total glucose used can be increased in the same way or by daily addition of small amounts. Glucose is used in greatest amount when the medium containing 100 mg. per cent is replaced daily. 3. Although glucose consumption appears necessary for survival of cultures it may be used at a rate far in excess of that required for life and maximal growth. Complete blocking of mitosis by colchicine does not alter the rate of glucose utilization. 4. Proteolytic activity of the cultures is shown by an increase in the amino nitrogen of the peptone medium after incubation with tissue. 5. Utilization of nitrogen from an amino acid medium is shown by a decrease in the amino nitrogen of this medium. Cells obtaining their nitrogen from amino acids proliferate as rapidly as those grown in a medium identical except for the substitution of peptone, but the cell type is markedly different, in that embryo muscle forms cells resembling regenerating adult muscle. 6. Lactic acid was formed in both the presence and absence of glucose. Its formation increased with increased glucose utilization. There is some evidence that lactate may be utilized, and that it favors growth in the absence of glucose. 7. Added pyruvate was rapidly metabolized by the tissues. It, too, favors growth slightly in the absence of glucose.     

Neural differentiation of amphibian gastrula ectoderm exposed to phorbol ester

Summary Ectoderm from early gastrula stages of amphibians was isolated and treated with phorbol 12-myristate 13-acetate. The ectoderm formed neural tissue and in a few cases also mesenchyme and melanophores. The control explants formed atypical epidermis. In explants treated with phorbol 12-myristate 13-acetate the mitotic rate was increased.     

Protein determination in the presence of glycerol by the Lowry procedure. I. Influence of reaction temperature and alkali.

The influence of glycerol on the Lowry determination of bovine serum albumin (maximum, 20 μg of BSA/sample) was studied. A modified procedure was introduced by applying low temperature during copper complex formation, followed by 37°C after the addition of the Folin reagent. This ensured good accuracy in absorbance readings at the highest glycerol concentration of 22%. However, a strong interference resulting from storing the samples in 0.2 n NaOH could not be overcome.     

Molecular cytogenetic characterization of two independent karyotypic anomalies in a patient with severe mental retardation and juvenile idiopathic arthritis

We report on a patient with severe mental retardation, dysmorphic features as well as juvenile idiopathic arthritis. G-banding indicated two independent karyotypic anomalies in this patient: an interstitial deletion del(X)(p21p22.3) and a rearrangement involving chromosomes 1 and 7, which represents a direct insertion, ins(7;1)(q36;p13.2p31.2). Non-random inactivation of the paternally derived del(X) chromosome was observed in blood lymphocytes and fibroblasts. High resolution analysis of the rearrangement involving chromosomes 1 and 7 subsequently revealed the additional submicroscopic deletion of at least 5 Mb at the 1p13.2 breakpoint. The deletion occurred on the paternal chromosome and encompasses the PTPN22 gene, already known to be associated with juvenile idiopathic arthritis. Our findings underline the importance of closely investigating the breakpoint regions of apparently balanced rearrangements in patients with abnormal phenotypes since complex chromosomal rearrangements (CCRs) may turn out to be unbalanced. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.