Use of cryopreserved peripheral mononuclear blood cells in biomonitoring

This study was performed to investigate the effect of storing blood samples by freezing on selected biomarkers and possible implications for biomonitoring. Comparative measurements were performed in order to investigate the use of cryopreserved vs. freshly separated peripheral mononuclear blood cells (PMBC) obtained from donor blood. Measurements of DNA-repair, mutant frequency, and subcell content were included. Samples for large biomonitoring studies are usually taken from study groups within a short timeperiod of days/weeks and storing of study material for later analysis can be necessary. We measured the DNA repair activity as dimethylsulfate induced unscheduled DNA synthesis (UDS) in PMBC incubated with either autologous plasma or fetal bovine serum (FBS). Comparison of the hprt mutant frequency by the T cell cloning assay was made in parallel. Finally the content of B/T-lymphocytes and monocytes was measured in phytohemaglutinin (PHA)-stimulated cultures at different time intervals. The results showed a higher DNA repair activity in cryopreserved samples compared with fresh samples. We also found differences in mutant frequencies with higher values in fresh samples. A significant correlation of frequencies was seen when comparing fresh with cryopreserved samples. Furthermore we recommend fresh human plasma used in UDS incubation media.     

Isopods as indicators of the copper content of soil and litter

Summary In two species of isopods (mainlyTracheoniscus rathkei, plus a fewOniscus asellus) total copper content as well as the amount of copper extractable with zinc-dibenzyldithiocarbamate in CCl₄ (CTC) were determined. Both copper fractions show near perfect relationship with total copper concentration of the litter collected in the isopods' habitats. Between copperrich and copper-poor sites in Tirol, Austria, mean total copper content of the isopods varies by a factor of 7, mean CTC-extracted copper by a factor of 140 (Table 2). With the exception of one, particularly impoverished, site the concentration of copper in the CTC-extracted compartment reflects the total copper concentration of the food of the animals. Both copper fractions increase with the weight of animals, but the proportionality factor of the increase is three times larger for total copper than for CTC-extracted copper.A simplified geological map of Tirol is given in which the relationship between copper content of soil and litter and of the isopods at selected sites is indicated.     

Refined localization of the pyruvate dehydrogenase E1α gene (PDHA1) by linkage analysis

Pyruvate dehydrogenase (PDH) E1α is a key component in the PDH complex which catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA. Defects in the gene coding for PDH E1α (PDHA1) are associated with a variety of clinical symptoms, often of a severe character. In the present study, the segregation of three polymorphic CA repeats located in PDHA1 was followed in the 40 CEPH reference pedigrees. Using these data, multipoint linkage analysis was carried out, refining the genetic location of PDHA1. The 16-point map presented locates PDHA1 in an approximately 3-cM interval between DXS999 and DXS365 with odds of more than 1000 : 1. From known physical localizations of the flanking marker loci, PDHA1 could be regionally assigned to Xp22.1-p22.2. The information provided should be of value in clinical settings. Received: 10 May 1996