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Biomedical subjects

P Helminen

Publications and source records attributed to P Helminen.

8 recordsLinked to original sources
PubMed1992

Does chemotherapy of hematological malignancies affect DNA fingerprint pattern?

We analyzed DNA fingerprints of lymphoma patients to find out whether DNA damage caused by irradiation and chemotherapy can result in DNA fingerprint changes, and whether the differences found previously in leukemia patients could be partially due to the treatment. In this study we did not find any post-treatment DNA fingerprint differences in 33 lymphoma patients, concluding, that the therapy of hematological malignancies does not affect DNA fingerprint patterns. Further, the variations of methylation do not either explain the detected differences in leukemic patients.

DNA Damage↗
PubMed1992

Amplification of three hypervariable DNA regions by polymerase chain reaction for paternity determinations: comparison with conventional methods and DNA fingerprinting.

The present study evaluates the usefulness of a PCR-based method for routine paternity testing in 35 paternity cases. This identification method which is based on amplification of three hypervariable genetic loci, apoB, D1S80 and HLA-DQ alpha, is compared, with regard to reliability and technical feasibility, to the conventional identification methods based on protein polymorphisms and to Southern blot hybridizations with multi- and single locus probes. Data obtained by PCR-amplification of these three loci resulted in paternity indices (56.1, geometric mean value) which are at the same level as the corresponding values derived from standard genetic blood group markers (42.7). The geometric mean value of the paternity indices obtained by Southern blot hybridization using three single locus probes (190.6) was more informative, and the most informative analysis proved to be Southern blot hybridization with multilocus probes. The technical feasibility and the reproducibility of the PCR-based analysis is, however, overwhelming, and if several highly polymorphic loci are amplified, the resolving power of PCR-analysis is similar to that obtained using multilocus probes.

Blood Grouping and Crossmatching↗
PubMed1991

Proving paternity of children with deceased fathers.

Determination of paternity was attempted in the case of three children whose putative fathers are dead using DNA samples of the paternal grandparents. The DNA analyses were performed with both multilocus and single-locus probes which resolve highly polymorphic areas of human genome. The results were conclusive with both types of probes and facilitated, for example, the exclusion of the brother of the putative father. The evidence for true paternity obtained with DNA analyses can be considered reliable in this type of "indirect" paternity in which tests based on protein polymorphism are inconclusive.

Blood Group Antigens↗
PubMed1990

DNA-fingerprint changes compared to karyotypes in acute leukemia.

Chromosomal analysis is routinely used in follow-up studies of acute leukemia, but it cannot be used in patients who do not have karyotypic abnormalities in blastic phase (10-46% of all cases). Recently we have demonstrated that unspecific DNA-fingerprint (DNA-F) changes can be detected in blastic phase of leukemia by DNA-F analysis. These changes can be used as molecular markers of the disease and in the follow-up studies of acute leukemia karyotyping and DNA-F analysis are complementary. The comparative analyses of leukemia samples with both these methods could help to localize minisatellite loci in chromosomes and reveal new DNA areas related to leukemia. New, more specific probes targeted to specific chromosomes could consequently be developed. We compared the DNA-F to the karyotypes of 50 acute leukemia patients. In blastic phase, 19 patients had DNA-F alterations and 31 patients abnormal karyotypes, 12 patients had both DNA-F alterations and karyotypic abnormalities. DNA-F changes were detected in six of the 16 patients with normal karyotypes and 19 patients with normal DNA-F had abnormal karyotypes at the time of diagnosis. Eleven patients showed neither DNA-F changes nor abnormal karyotypes in blastic phase. Three acute myeloid leukemia (AML) patients with DNA-F changes in blastic phase had trisomy eight as a sole abnormality or combined with balanced translocation, which suggests that there might be AML associated minisatellite locus in chromosome 8. In other cases the karyotypes were complicated and no clear evidence of the relationship of DNA-F changes with other chromosomes could be found.

Acute Disease↗
PubMed1989

New molecular marker in AML: DNA-fingerprint differences between leukemic phase and remission in acute myeloid leukemia.

DNA-fingerprint (DNA-F) analysis, based on the polymorphism of the tandem repeats of minisatellite areas in human genome, has a capacity to reveal minor changes in dispersed areas of human genome. In this study we have applied DNA-F analysis to the detection of differences between leukemic phase and remission in acute myeloid leukemia (AML). In order to identify normal and leukemic cell populations we used two molecular probes: Jeffreys' minisatellite probes 33.6 + 33.15 and M13 wild-type phage probe. Comparison of varying minisatellite fragments between remission and diagnosis/relapse was performed by Southern blot hybridization in 21 patients with AML. The results demonstrate that Southern hybridization with minisatellite probes can detect differences in DNA-fingerprints between leukemic phase and remission in 44% of AML patients. Thus differences in DNA-fingerprinting provides a new molecular marker, which can be useful in the detection of residual disease as well as in the study of the pathogenesis of AML.

Biomarkers, Tumor↗
PubMed1988

Application of DNA "fingerprints" to paternity determinations.

26 cases of disputed paternity were tested by the methods routinely used in Scandinavian countries and by the DNA "fingerprinting" technique. In all the studied cases the results of DNA analyses were similar to those obtained with the routine examinations based on protein polymorphisms; and, in the cases where even HLA typing did not distinguish between tentative fathers, the results obtained with DNA analyses were unambiguous.

Autoradiography↗
PubMed1988

Differences in DNA-fingerprints between remission and relapse in childhood acute lymphoblastic leukemia.

DNA "fingerprint" (DNA-F) analysis, based on the polymorphism caused by numeric variations in the tandem repeats of minisatellite areas of the human genome, has a potential capacity to reveal even minor genomic changes. In this study we have applied DNA-F to the detection of residual disease in leukemia. In order to identify normal and leukemic cell populations, we used two molecular probes: Jeffrey's minisatellite probes and M13 wild type phage probe, which detect different sets of polymorphic fragments in the human genome. Comparison of varying minisatellite fragments between remission and relapse was performed by Southern blot hybridization in seven patients with acute lymphoblastic leukemia (ALL). The results suggest that Southern hybridization with DNA "fingerprint" probes can prove to be a sensitive method in the detection of minimal residual disease in ALL.

Adolescent↗