Biomedical subjects

Frank Heidorn

Publications and source records attributed to Frank Heidorn.

4 recordsLinked to original sources

PubMed2002

Expression and location of the bradykinin B2 receptor in rat testis.

To investigate the possible role of the local tissue kallikrein-kinin system in spermatogenesis, we analyzed gene expression and cellular distribution of the bradykinin subtype-2 receptor (B(2) receptor) in the rat testis. Reverse transcription-polymerase chain reaction revealed B(2) receptor expression in testis and primary cultures of Sertoli cells and peritubular cells isolated from immature and mature rats. In situ hybridization of the B(2)-receptor mRNA showed intense labeling of cells on the base of the seminiferous tubule, whereas the autoradiographic signals gradually decreased toward the lumen. Immune histochemistry using testicular sections of pubertal and adult rats showed specific staining for the B(2)-receptor protein in cells of the adluminal compartment of the seminiferous tubules, especially on pachytene spermatocytes and spermatids. This immunostaining varied with the stages of the seminiferous cycle. The receptor protein was also observed on peritubular cells of pubertal rats. In conclusion, we demonstrated a stage-specific expression of the bradykinin B(2) receptor in different cells of the seminiferous tubules of the rat testis. The results point to a possible function of the tissue kallikrein-kinin system in the local regulation of spermatogenesis.

Animals↗

PubMedDate not supplied

[Storage time for criminal trace evidence].

The article discusses the question if and under what conditions trace evidence may be stored for DNA analysis. The authors report on several cases in which methodological improvements or even the introduction of DNA technology itself helped to identify the perpetrator or to rule out a suspect, who may already have been wrongly convicted, many years after the offence. Under medical and scientific aspects these cases seem to speak in favour of unlimited storage. German law does not contain explicit regulations on the storage of trace evidence of unknown origin, although it seems admissible under existing law. In view of a minor need of protection as against a high interest in the preservation of trace evidence, storage for an unlimited period of time seems necessary.

DNA Fingerprinting↗

PubMedDate not supplied

[Interindividual morphologic variability as reason for misinterpretations in forensic osteology exemplified by a rib].

Bone finds make great demands on the examiner. The first priority is to establish the remains as human, because then further analyses have to be performed for identification. Especially for bone fragments it may be extremely difficult to determine whether they are of human or animal origin. In the reported case a bone fragment similar to a human rib was found in a medieval town together with more than 300 non-human bones. As it turned out, a medieval cesspit had been opened during excavation works. Even an mtDNA analysis could not answer the question whether the rib was of human origin. A direct comparison with numerous ribs of humans and mammals showed the great interindividual variability, but in the end it was possible to rule out a human origin and to identify the fragment as the third left rib of a pig.

Animals↗

PubMedDate not supplied

[Heteroplasmy in mtDNA in a set of dizygotic twins].

The authors report on a case of a dicygotic female twin pair, one of them containing a T/C heteroplasmy in two (heart and brain) of five analysed organs at position nt204 of the HV2 region. Results and especially the evidence of an unequal distribution of the heteroplasmy are discussed.

Adolescent↗