Premature chromosome condensation in a case of Fanconi's anemia.

Evidence is presented for the occurrence of premature chromosome condensation (PCC) from micronuclei even in the first in vitro mitoses in a case of Fanconi's anemia.     

Conservation of Glycerolated Cultures of Ochromonas danica and O. malhamensis at −10 C

SYNOPSIS. Ochromonas danica in a complex natural growth medium dies at 6–10 C in 4 days; O. malhamensis in ∼2 days. O. danica grown in the medium supplemented with 4.0% glycerol survived at −10±2 C for 35 days, and with 8% glycerol 29 days. O. malhamensis lasted only to 5 days in these media supplemented with 4% glycerol. Ethylene glycol and dimethylsulfoxide were too toxic to be effective. Difficulties in freeze-preservation of certain other phagocytic cells, notably blood granulocytes having comparatively simple flexuous outer membranes, add interest to use of O. danica and O. malhamensis as test organisms for preservation methods, especially in the convenient, inexpensive -10 to -20 C range. Biphasic media with an overlay of distilled water serve for conservation at room temperature. Problems of mutational erosion of these photosynthetic phagotrophs are discussed.     

Characterization of purine nucleotide metabolism in primary rat muscle cultures

The synthesis and metabolic fate of purine nucleotides were studied, employing labeled precursors, in primary rat muscle cultures. The cultures were found to produce purine nucleotides, by de novo and salvage pathways, both exhibiting dependence on cellular availability of substrate 5-phosphoribosyl-1-pyrophosphate (PPRibP). Depletion of cellular PPRibP decelerated the rate of purine synthesis, whereas increasing PPRibP generation by high Pi concentration in the incubation medium, accelerated purine synthesis. Ribose accelerated purine synthesis, indicating that ribose 5-phosphate availability in the cultured muscle is limiting for PPRibP synthesis. The study in the muscle cultures of the metabolic fate if IMP formed from [14C]formate and that of nucleotides formed from labeled purine bases, revealed that the main flow in the nucleotide interconversions pathways is from AMP to IMP. The flow from IMP to GMP and to AMP appeared to be of a lesser magnitude and virtually no flow could be detected from GMP to IMP. The greatest proportion of radioactivity of purine nucleotides following synthesis by either de novo or salvage pathways, accumulated in IMP, reflecting the relative rates of flows between the various nucleotides and probably also a relatively low, or inhibited activity of the IMP nucleotidase. The results suggest that primary muscle cultures are a plausible model for the study of the role of purine metabolism in muscle work.     

Detection of a light-sensitive pool of cGMP in goldfish cone color receptors by immunocytochemistry

A procedure for the immunocytochemical localization of cGMP in the goldfish retina is described. The procedure is then used to evaluate the presence of cGMP in cone color receptors in retinas from dark-adapted and light stimulate fish. The results show that cone color receptors in dark-adapted retinas contain large amounts of immunocytochemically defined cGMP in the ellipsoid region, which are greatly reduced after light exposure.     

Pränatale Chromosomenanalyse mit Mosaikbefund 46,XX/92,XXXX

Zusammenfassung Die Chromosomenanalyse aus Zellen der Amnionflüssigkeit, entnommen bei einer 28jährigen Frau in der 30. Schwangerschaftswoche, erbrachte einen Mosaikbefund aus weiblichen diploiden und tetraploiden Metaphasen. Die Blutzellkulturen des gesunden Neugeborenen zeigten einen normalen Karyotyp. Zusätzliche Untersuchungen sprechen für eine in vitro-Entstehung des Mosaiks.

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Prental chromosome analysis with mosaic statement 46,XX/92,XXXXPosible of an eroneous diagnosis

Summary The chromosome analysis from cells of the amniotic fluid performed in a 28 year old woman in the 30th week of pregnancy revealed a mosaic of female diploid and tetraploid metaphases. Lymphocyte cultures from the healthy newborn showed a normal female karyotype. Additional findings indicate an in vitro origin of the mosaic.

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Direktor: Prof. Dr. H. Lüers

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Leiter: Prof. Dr. E. Saling

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Nach einem Vortrag, gehalten am 11. 7. 1970 auf der Tagung der Gesellschaft für Anthropologie und Humangenetik (Sektion Cytogenetik) in Kiel.