Biomedical subjects

J Dunker

Publications and source records attributed to J Dunker.

3 recordsLinked to original sources

PubMed2003

Parallel DNA template preparation using a vacuum filtration sample transfer device.

Solid-phase techniques have facilitated the handling of biochemical analytes. This has stimulated the development of systems by which large sample panels can be analyzed with high levels of security and quality. We describe a sample transfer device based on the principle of vacuum filtration, which enables parallel handling of 96 samples of analytes bound to Sepharose beads. The tool was employed for strand separation of DNA samples, by attracting the beads to filter probes while passing them between the reagent solutions. The samples were analyzed using Pyrosequencing technology and proved to yield genotyping results of high quality. The presented sample preparation procedure provides an important link in the development of integrated systems for rapid genetic analysis at a low cost. In addition, the same filter could be reused extensively with very low risk for detectable cross-contamination between assays and without any reduction in processing capacity, thus further reducing the cost per analyzed sample.

DNA↗

PubMed1991

Interpreting palmar sweat prints.

The plastic impression method to assess the number of active palmar sweat glands (PSI) was used to study changes of sweat gland activity during several phases of dental treatment. Subjects were 64 female and 38 male patients at a dental surgery. At the beginning they scaled five typical dental situations in terms of perceived threat: waiting-room before treatment: sitting down in the dental chair; dentist enters and starts treatment; after treatment in the dental chair; and back in waiting-room after treatment. Four prints were taken in the waiting-room before treatment and one in each other situation described above. The average of prints 3 and 4 was used for phase comparisons. Palmar sweat index values were generally in accordance with the threat of the situations. In particular there was a rise from waiting-room to sitting down in the dental chair and a further increase at the dentist's entry, whereafter values dropped considerably. A significant decrease from the first two waiting-room values to the following two suggests that the PSI reacts sensitively to the novelty of the assessment procedure itself and that the very first recordings should hence not be taken into evaluation.

Adolescent↗

PubMed1990

[The number of active sweat glands (PSI, palmar sweat index) in stress caused by blood donation].

The number of active sweat glands (PSI), heart rate, systolic (SBP) and diastolic blood pressure (DBP) were assessed every 2 minutes in 109 male blood donors. Three measurements were taken at the beginning (adaptation phase), three later but before blood donation (baseline), one during the venous puncture (phase 3), three thereafter but still during donation (phase 4), and four after removal of the cannula (phase 5). Analysis of variance yielded significant differences between phases; PSI and SBP behaved similarly, decreasing from adaptation to baseline, rising during puncture, and decreasing again thereafter. Mean within-subject correlations between variables were significantly above 0. Between-subjects correlations were significantly negative for PSI and DBP. This is best explained by the influence of age on both variables. Correlations of PSI values as determined by three raters had a mean of 0.90. The study shows that the PSI is a very sensitive indicator of stress that is easily accessible also in field studies.

Adult↗