The reelin signaling pathway plays a crucial role during the development of laminated structures in the mammalian brain. Reelin, which is synthesized and secreted by Cajal-Retzius cells in the marginal zone of the neocortex and hippocampus, is proposed to act as a stop signal for migrating neurons. Here we show that a decreased expression of reelin mRNA by hippocampal Cajal-Retzius cells correlates with the extent of migration defects in the dentate gyrus of patients with temporal lobe epilepsy. These results suggest that reelin is required for normal neuronal lamination in humans, and that deficient reelin expression may be involved in migration defects associated with temporal lobe epilepsy.

In order to identify polymorphic positions and to determine their frequency in the human mitochondrial D-loop containing region, the mitochondrial DNA (mtDNA) control region of 200 unrelated individuals from Germany were amplified and directly sequenced. Sequence comparison led to the identification of 190 mitochondrial lineages as defined by 202 variable positions. The most frequently occurring lineage comprised 5 individuals, whereas 186 types of D-loop sequences were observed in only one individual. Of the sequences studied 7% are not unique but show at least one counterpart with an identical haplotype. The majority (61%) of the control regions investigated showed between four and eight nucleotide positions deviating from the reference sequence. The maximum number of deviations observed in a single control region was 18. The majority of the variable positions in the D-loop region (88%) are located within three hypervariable regions. Sequence variations are caused by nucleotide substitutions, insertions or deletions. As compared to insertions and deletions, nucleotide substitutions make up the vast majority of the mutations (90%). We have predominantly found transitions (75%) and a significantly lower frequency of transversions (15%) whereas insertions (6%) as well as deletions (4%) are rather rare. Upon sequencing the mitochondrial control region from 200 German Caucasians the genetic diversity was estimated at 0.99. The probability of two randomly selected individuals from a population having identical mtDNA types is 0.6%.

Human parvovirus B19 has been linked to a variety of cardiac diseases, as well as to erythema infectiosum, acute arthropathy, and fetal hydrops. A causal association between viral infection and cardiac disease was frequently postulated following the detection of B19 DNA by PCR in endomyocardial biopsy specimens. Since the lifelong persistence of B19 DNA in bone marrow, skin, synovia, tonsils, and liver was previously reported, the aim of our study was to investigate the possibility of asymptomatic B19 DNA persistence in heart tissue. Myocardial autopsy and postmortem blood samples were prospectively collected from 69 bodies sent to the Department of Forensic Medicine, Freiburg University Medical Center, for inquests. All study subjects were screened for B19-specific antibodies using a commercial enzyme immunoassay. Tissue samples were analyzed by real-time PCR for the presence of viral DNA. Since the presence of B19 genotype 2, known to have been circulating before 1960, would prove long-lasting persistence, the presence of the B19 genotype was retrospectively determined in seven of the study subjects by melting temperature analysis and sequencing of the PCR product. B19 DNA was found in myocardial samples from 46 of 48 seropositive and in none of 21 seronegative individuals. B19 genotype 1 was found in three patients born between 1950 and 1969. Genotype 2 was found in four patients born between 1927 and 1957. Our findings suggest lifelong persistence of B19 DNA in heart tissue. Thus, the detection of B19 DNA in myocardial biopsy specimens alone is not sufficient to postulate a relationship between B19 infection and cardiac disease.

No abstract

The first and second hypervariable regions of the human mitochondrial DNA control region contain two homopolymeric stretches of cytosine (nt 16184-16193 and nt303-315, respectively). According to the Cambridge reference sequence these homopolymeric stretches are interrupted by thymine (T), at positions 16189 and 310, respectively. Monotonous runs of the same base have been suggested to be hot spots for mutations, probably caused by replication slippage, resulting in length heteroplasmy. This paper describes a rapid method based on restriction cleavage of labelled PCR products encompassing the homopolymeric tract in HVII to quantify the relative proportions of different length variants present in an individual. To compare the accuracy of this method, cloned PCR products from several heteroplasmic individuals have been additionally sequenced.

No abstract

Spectrophotometric measurements were performed on intra- and/or subcutaneous bruises occurring in direct temporal connection with peracute fatal trauma. The purpose of these measurements was to determine whether the visual colour impression of a fresh traumatic extravasation can give information on the localisation of the haemorrhage in a certain tissue layer. After visual assessment of the colour of the bruise, the spectral reflectance curves and the CIE-L*a*b* colour values were determined with the help of a diode array spectrophotometer. The localisation and size of the haemorrhages in the cutis and/or subcutis were evaluated morphologically after incision of the skin. It was confirmed that there is a relationship between the colour impression and the localisation of the bruise. Bruises localised near the surface have a more reddish appearance while bruises in deeper layers give a more bluish colour impression. An explanation may be found in the optical characteristics of skin. Blood localised in the subcutis appears blue on the surface due to scattering processes in the dermis (Rayleigh scattering), as the blue wavelengths of the light are scattered (and thus reflected) to a greater extent than the red wavelengths.

The first ever German-language clinical guidelines for the treatment of NSSI have now been issued. Psychotherapy is the treatment of first choice. More research is needed so that subgroups with different disease courses can be more clearly defined.