Successful DNA typing of a urine sample in a doping control case using human mitochondrial DNA analysis

In a doping control case, a urine sample was tested positive for nandrolon. We were asked by the athlete to perform DNA investigations on the questioned urine sample and compare these to a fresh blood sample taken from the athlete in order to detect or rule out manipulation and/or switching of the samples. The urine sample had been collected nine months prior to the investigation and had been stored at 4 degrees C. In a first approach, nuclear DNA systems were investigated that failed with the exception of the Amelogenin system. Due to the high copy number of mitochondrial DNA molecules and the robustness of the mitochondrial genome, we investigated the HVR I and HVR II regions of mitochondrial DNA and obtained reproducible and clear sequencing results for both the blood and the urine samples. Due to the identical sequences, it could not be excluded that the blood sample and the urine sample were from the same individual or an individual having the same maternal lineage.     

A discrimination method for paper by Fourier transform and cross correlation

A non-destructive method for discriminating between different types of paper has been proposed, using image analysis, Fourier transformation, and cross-correlation matching. A fast Fourier transform (FFT) is used to extract the periodicity in the structure of paper that results from the manufacturing processes. The light-transmission images of the paper to be Fourier transformed are obtained from a flatbed image scanner. The similarity between the power spectrum of the FFT of the sample and that of a reference is quantified using a cross-correlation matching method. An advantage of using frequency analysis is that periodicity can be detected even if the sample is damaged or is printed on. The technique works on samples as small as 2 cm2.     

Analysis of ionic ratios in myocardial tissue and their relation to cardiac damage

The authors evaluated the usefulness of the postmortem biochemical analysis of ionic ratios in different parts of the heart and their relation to cardiac damage caused by chest trauma, as observed by anatomopathologic study. Fifty-nine 59 cases were studied, selected from routine necropsies, and samples were taken from different sites of cardiac tissue. The cause of death was trauma in 40 cases and nontraumatic causes in 19 cases. The object of this study was to analyze the levels of Na+, K+, Ca+2, Mg+2, and Zn+2 in different zones of the heart, and the relationship between intracellular and extracellular ion ratios and the different causes of death and any anatomopathologic alterations observed. The biochemical tests revealed a possible relation between the ionic values and cause of death. Alterations in cell membrane permeability and corresponding modification of the ionic ratios were produced earlier than histologic alterations, which need longer to establish themselves whether or not they follow a traumatic process.     

What is the best sample for determining the early postmortem period by on-the-spot flow cytometry analysis?

The level of degradation of DNA as a means for determining the time of death has been proposed as a valid adjunct to the classic thanatochronologic methods. The twofold aim of this work was to determine which organ might reveal both a correlation between the percentage of degradation of the DNA and the time lapse since death, and would be easiest to sample and yield the most reproducible results even in technically unfavorable situations such as on-the-spot investigations at the scene of death. A comparison of the spleen, blood, and liver showed that hepatic tissue best meets these specific needs because it shows a virtually linear correlation between the time elapsed since death and the level of degradation of the DNA, and it can easily be sampled at the scene of death by use of a common biopsy needle.     

Immunohistochemical study of basic fibroblast growth factor and vascular endothelial growth factor expression for age determination of cutaneous wounds

The authors investigated the expression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) during skin wound healing using immunohistochemical techniques. After a full-thickness incision was made on the dorsal skin, mice were killed 0.5, 1, 3, 8, 24, 72, 144, or 240 hours after incision, and the wound was excised. To evaluate the influences of postmortem degeneration, cutaneous wound excision was performed 1 to 5 days after the mice were killed. The excised wounds were stained by the conventional streptoavidin-biotinylated peroxidase complex method, using specific antibodies, and the ratio of the number of positive cells to total cells was determined. Expression of bFGF was detected in the nuclei of epidermal cells and fibroblasts in the early 0.5- to 1-hour phases and the late 24- to 144-hour phases. Expression of VEGF was detected in the cytoplasm of epidermal cells in the 24- to 144-hour phases. Immunoreactivity of both cytokines was detected 1 day post mortem and was especially well preserved in the fibroblasts. Time-dependent expression of both factors suggested that they would be useful markers for the determination of wound age. However, bFGF should be superior to VEGF because of its earlier expression and because of its more persistent expression in dermal fibroblasts with increasing postmortem interval.