A simple, small and low cost permanent magnet design to produce homogeneous magnetic fields.

A new portable, pocket-size NMR probe based on a novel permanent magnet arrangement is presented. It is based on a Halbach-type magnet design which mimics the field of a spherical dipole by using cylindrical bar and ring magnets. The magnet system is made up of only three individual magnets, and most field calculations and optimisations can be performed analytically. A prototype system has been built using a set of small, off the shelf commercially available permanent magnets. Proton linewidths of 50 ppm FWHM could be achieved at a field strength of 1T. Calculations show that with custom-sized permanent magnets, linewidths of less than 1 ppm can be achieved over sample volumes of up to 1 mm3, which would in theory enable chemical shift resolved proton spectroscopy on mass-limited samples. But even with the achieved linewidth of 50 ppm, this can be a useful portable sensor for small amounts of liquid samples with restricted molecular mobility, like gels, polymers or high viscosity liquids.

[Experimental testing of a new coil design for endoluminal MRI applied to the pig stomach]. / Experimentelle Erprobung eines neuen Spulendesigns zur endoluminalen MRT am Beispiel des Schweinemagens.

PURPOSE: Experimental feasibility study of a new MR-Coil concept for enhanced visualization of the gastric wall. MATERIAL AND METHODS: The newly developed single-loop receiver coil for endoluminal imaging (Fraunhofer Institute, St. Ingbert, Germany) was evaluated in 4 explanted pig stomachs in a 1.5T MR unit (Siemens Symphony, Erlangen, Germany) with T1 w and T2 w MR sequences in three planes. The new coil consists of a foldable and self-expanding single loop coil (receiver coil) of a shape memory metal (nitinol). It was covered with a biocompatible material (silicone) to prevent direct contact of the wire with stomach tissue. The coil assumes a circular configuration with a diameter of 8 cm because of its memory metal properties. The flexible characteristics of the material used allow the passage through the instrument channel (13 mm diameter) of a specially designed MR-compatible endoscope. The purpose of our study was to assess feasibility of the coil design as a first step in developing a new endoluminal MRI-concept. Additionally the number and signal intensity of visible gastric wall layers were evaluated and findings were correlated with histopathological results of a pig stomach. RESULTS: The new coil concept was a feasible system in all 4 cases and showed good image quality for analysis. On T1 w images, 3 layers were visible in all cases, and on T2 w images 4 different gastric wall layers were seen in 2 cases. Due to histopathological correlation, the different gastric wall layers were identified as follows: mucosa, submucosa and muscularis propria if three layers were depicted; in cases of 4 visible wall layers, serosa and subserosa could be detected additionally. For each gastric wall layer, a distinct signal intensity was found. CONCLUSION: The new MR coil concept for endoluminal imaging proved to be a feasible technique. Good differentiation of gastric wall layers in the pig stomach could be demonstrated. We have shown that endoscopic MR-imaging with our new coil concept is a valuable technique for the visualization of gastric wall layers. Due to this fact, follow-up studies including assessing safety aspects are necessary to finally conduct an experimental-clinical study on in-vivo human gastric specimens to detect tumor growth and morphology within the gastric wall. Endoscopic MRI may have the potential in the future to overcome today's limitations of diagnostic imaging in gastric cancer.

A brief history of forensic entomology.

Apart from an early case report from China (13th century) and later artistic contributions, the first observations on insects and other arthropods as forensic indicators were documented in Germany and France during mass exhumations in the late 1880s by Reinhard and Hofmann, whom we propose recognizing as co-founders of the discipline. After the French publication of Mégnin's popular book on the applied aspects of forensic entomology, the concept quickly spread to Canada and the US. At the time, researchers recognized that the lack of systematic observations of forensically important insects stood in the way of their use as indicators of postmortem interval. General advances in insect taxonomy, and ecology helped close this gap over the following decades. Many early case reports dealt with alleged child homicides, including the suspected use of sulphuric acid. In this context, it was shown that ants, cockroaches, and freshwater arthropods could produce postmortem artifacts suggestive of child abuse. After the World Wars, few forensic entomology cases entered the scientific literature. From the 1960s to the 1980s, Leclecq and Nuorteva were primarily responsible for maintaining the method in Central Europe, with a focus on case work. Since then, basic research in the US, Russia and Canada has opened the way to the routine use of entomology in forensic investigations. The following article gives a brief overview of historic developments in the field. A major focus is on the work done between 1850 and 1950. Since sources from that time remain difficult to track down, the article also includes a historic bibliographical overview on forensic entomology of that era.

Child neglect and forensic entomology.

Close co-operation between forensic scientists, medico-legal doctors, and police forces made it possible to estimate not only the post-mortem interval but also the time since a child was neglected. On the skin surface under the diaper (anal-genital area), third instar larvae of the false stable fly Muscina stabulans FALLEN, and the lesser house fly Fannia canicularis L. were found. F. canicularis adults are attracted to both feces and urine. From the face, larvae of the bluebottle fly Calliphora vomitoria L. were collected. C. vomitoria maggots are typical early inhabitants of corpses. From the developmental times of the flies, it was estimated that the anal-genital area of the child had not been cleaned for about 14 days (7-21 day range), and that death occurred only 6-8 days prior to discovery of the body. This is the first report where an examination of the maggot fauna on a person illustrated neglect that had occurred prior to death.

A homicide in the Ukraine: DNA-based identification of a boiled, skeletonized, and varnished human skull, and of bone fragments found in a fireplace.

In an apartment, bone fragments were found in a fireplace. Furthermore, a varnished skull was found elsewhere in the same apartment. The tenant confessed to a murder and stated that the head of a victim, a girl, was boiled for 12 hours. He stated that the soft tissue was then removed and the skull was varnished. Other parts of the body were burned to ashes in an open field. Comparison of loci D19S252, CD4, CYAR04, TII01, F13A01, F13B, and D6S366 from the skull and the bone remains to loci of the mother of a missing girl showed that the skull came from that missing child. Biological maternity was calculated as 99.99%. The bone pieces were DNA typed as male and did not share alleles with the mother in several systems. Therefore, they belonged to a different (human) victim.

[Unilateral occurrence of blowfly maggots in the face of a decomposing body]. / Rein einseitiges Auftreten von Schmeissfliegenmaden im Gesicht einer Faulleiche.

The corpse of a 41-year-old medical doctor was found in his bed. The body was partially dried out; parts of the hip region were skeletonized due to maggot activity. In the facial region of the corpse, blowfly maggots (Lucilia (Phaenicia) sericata [Meigen]) were found exclusively in one eye socket. This is an unusual occurrence since on that side, a bedlight (40 W light bulb) had been burning during the seven week post mortem interval. All other lights in the apartment were switched off, and no direct sunlight could enter the space where the body was found (only a TV set had been running all the time, ca. 2 m away from the head at the foot end of the bed). Obviously, the maggots who usually flee light had used up the one eye that was further away from the bedlight as a feeding source. Since the continuing mummification of the corpse led to a substantial restriction of feeding material, the maggots finally switched to the eye that the light was shining on.

First report of nonpsychotic self-cannibalism (autophagy), tongue splitting, and scar patterns (scarification) as an extreme form of cultural body modification in a western civilization.

As part of her current lifestyle, a 28-year-old Caucasian woman routinely injures and allows subsequent healing of her skin and other tissues. Her body modifications include a "split tongue" (a tongue split to the base), which does not interfere with speaking and eating. Other modifications include large scarification patterns produced by branding and cutting. This woman has been known to eat parts of her skin that were previously cut out of her body. She also performs "needle play" by allowing medical syringe needles to be lodged temporarily under her skin. The patient had a normal childhood, is currently employed full-time as an office manager, and is psychologically stable. Although one other case of self-induced penoscrotal hypospadias is known, this is the only report of extensive, nonpsychotic, autodestructive behavior. However, this may not be the case in the future as an increasing number of young individuals have become interested in body modifications.

[Forensic entomology exemplified by a homicide. A combined stain and postmortem time analysis]. / Forensische Entomologie am Beispiel eines Tötungsdeliktes. Eine kombinierte Spuren- und Liegezeitanalyse.

The combined analysis of both ant and blow fly evidence recovered from a corpse, and from the boot of a suspect, suggested that an assumed scenario in a high profile murder case was likely to be true. The ants (Lasius fuliginous) were used as classical crime scene stains that linked the suspect to the scene. Blow fly maggots (Calliphora spec.) helped to determine the post mortem interval (PMI) with the calculated PMI overlapping with the assumed time of the killing. In the trial, the results of the medico-legal analysis of the insects was understood to be crucial scientific evidence, and the suspect was sentenced to 8 years in prison.

Short tandem repeat (STR) locus HUMD8S306 in a large population sample from Germany.

Applied DNA typing in medico-legal investigations, in criminalistic practice, and in paternity cases often relies on high inclusion and exclusion probabilities. For that reason, the short autosomal tandem repeat locus D8D306 was validated for forensic use and incorporated into a nonoverlapping multiplex reaction with HUMDHFRP2 and HUMCD4: The allele frequencies of D8S306 in four different regions of Germany (n = 1220 alleles) were determined for use in a population database; the allele distributions did not significantly deviate from each other. The hererozygosity of D8S306 is 83%, expected exclusion chance in stain cases is 96% (paternity cases: 69%), the lowest amount of successfully amplified DNA was 30 pg. The alleles are in Hardy-Weinberg equilibrium.

Allele frequency distributions of the polymorphic STR loci HUMVWA, HUMFES, HUMF13A01 and the VNTR D1S80 in a Filipino population from Metro Manila.

Allele frequency distributions at the short tandem repeat (STR) loci HUMVWA, HUMFES, HUMF13A01 and of the variable number of tandem repeat (VNTR) locus D1S80 were determined in a Filipino population from Metro Manila (103 individuals) by use of the polymerase chain reaction (PCR) followed by polyacrylamide gel electrophoresis (PAGE). The exact test demonstrated that all four loci had no deviations from Hardy-Weinberg equilibrium (HWE) with the only reservation that the exact test p-value for F13A01 is weak. The discriminating power is 0.82 for D1S80, and the expected exclusion chance is 0.85 for F13A01, 0.83 for FES, and 0.93 for VWA. The observed heterozygosity rates are 0.63 for D1S80, 0.66 for F13A01, 0.67 for FES, and 0.80 for VWA. The exact test for independance between all loci gave a p-value of 0.0195. This is the first time that Filipino population data of DNA loci of forensic importance are reported.

Six forensic entomology cases: description and commentary.

Insects are known to be useful in estimating the postmortem interval (PMI). Here several cases are reported which show that a wide range of applications in medicolegal questions and hygiene together or apart from estimating the PMI can be answered by use of forensic entomology techniques, including close observation of larval development. Case 1 describes how blowfly larvae fell from a putrefied corpse, hid, and finally emerged from pupae three months after disinfection and renovation. In case 2, the entomological state of the decomposed corpse of a heroin user is described. Case 3 deals with a single adult Protophormia terranovae found in the skull of a partially mummified woman. Case 4 reports the finding of Serratia marcescens bacteria in red Muscina stabulans pupae which were found on a 5-day-old corpse. In case 5, blowfly eggs on the corpse of another heroin user are interpreted as an indication of the decedent being laid outside at night after his death in a flat. Case 6 deals with the finding of Parasarcophaga argyrostoma, which in Cologne might be an indicator species which tells if a corpse was lying outside at least for some time.

Random amplified polymorphic DNA (RAPD) typing of necrophageous insects (Diptera, Coleoptera) in criminal forensic studies: validation and use in practice.

To permit quick identification of arthropods, random amplified polymorphic DNA typing (RAPD) was used to support classical morphological and medico-legal analysis of maggots on a human corpse. The method was employed to determine if maggots which were found on the inside of a body bag were identical (a) with maggots found on the outside of the bag, and (b) pupae found on the floor under the corpse. Pre-mixed RAPD reaction beads together with semiautomatic computer aided analysis of the PCR products are shown to discriminate between closely related necrophageous insect species (flies and beetles) found on corpses. From the 11 RAPD primers used, one alone was sufficient in resolving a practical forensic situation. This is the first report of a forensic application of RAPD DNA typing.

The quantitative alteration of the DNA content in strangulation marks is an artefact.

UNLABELLED: It is frequently difficult to prove the vitality in cases of fatal hanging. Using impulse cytophotometry, Müller et al. (Krim. Forens. Wiss. 44, 1981) reported on possibly vital alterations of the DNA content in five strangulation marks (hypodiploidy). The objective of the present study was to perform a re-evaluation by means of current methods of quantitative DNA analysis. The investigation included 24 cases of hanging (typical, n = 11; atypical, n = 13). DNA was extracted by use of phenol/chloroform and quantitated photometrically in relation to the tissue weight. In addition, skin specimens were examined histologically and their water content was determined. The mean DNA content of strangulation marks was 3.2 micrograms DNA/mg tissue, that one of uninjured skin (control) 1.4 microgram DNA/mg tissue. The ratio of DNA content between strangulation grooves and control skin varied from 1.2 to 5.2 (average: 2.4) implicating apparently elevated DNA levels in strangulation marks. Histology revealed typical changes with absence of leukocyte infiltration suggesting mechanical compression of DNA containing layers. The additional determination of the water content emerged-in dependence on the macroscopic appearance, dried or non-dried-reduced values for strangulation marks (average: 42% vs. 66%). Statistical analysis demonstrated a significant correlation between elevated DNA content and reduced water content of strangulation marks. CONCLUSION: the markedly elevated DNA content of strangulation marks is interpreted as an artefact due to drying of the skin with a reduction of the water content (and weight) in the course of mechanical cutaneous alterations (compression). Therefore, quantitative changes in the local DNA content of the groove have no importance as a sign of vitality in fatal strangulations.

DNA typing in forensic medicine and in criminal investigations: a current survey.

Since 1985 DNA typing of biological material has become one of the most powerful tools for personal identification in forensic medicine and in criminal investigations [1-6]. Classical DNA "fingerprinting" is increasingly being replaced by polymerase chain reaction (PCR) based technology which detects very short polymorphic stretches of DNA [7-15]. DNA loci which forensic scientists study do not code for proteins, and they are spread over the whole genome [16, 17]. These loci are neutral, and few provide any information about individuals except for their identity. Minute amounts of biological material are sufficient for DNA typing. Many European countries are beginning to establish databases to store DNA profiles of crime scenes and known offenders. A brief overview is given of past and present DNA typing and the establishment of forensic DNA databases in Europe.

Five cases of forensic short tandem repeat DNA typing.

In medicolegal samples DNA is often broken into fragments. In many cases, only the amplification of short tandem repeated DNA stretches (STRs), which are located in noncoding regions, allows DNA typing of such degraded materials. To demonstrate the high diversity of biological materials which forensic biologists have to deal with, and to outline the success rates and limits of the method, we describe five cases (minute amount of tissue on barrel, tissue in decay, tumor tissue, sperm after multiple rape, stored urine samples) in which forensic DNA typing was successfully performed by use of the short tandem repeats HUMDHFRP2, HUMD8S306, HUMCD4, HUMF13A1, HUMTH01, HUMVWA, and HUMFES.

[Collecting insects, spiders and crustaceans for criminal forensic study]. / Asservierung von Insekten-, Spinnen- und Krebsmaterial für die forensisch-kriminalistische Untersuchung.

Use of entomological evidence in medico-legal questions allows a wide range of applications, e.g. estimation of postmortem intervals, investigation of taking away a corpse to another location and many others. An important point is to store and eventually breed carrion-associated arthropods in the right way. As a rule all arthropods should be stored cool in 70% ethanol at the crime scene to allow subsequent species determination. Basic breeding instructions are outlined, two breeding devices are described, and an overview on useful literature is given.

[Expert insect identification in cases of decomposed bodies]. / Zur insektenkundlichen Begutachtung in Faulleichenfällen.

We report two cases in which putrefied corpses were found in the state of massive myasis (colonisation of files); in one case, also beetles could be collected. Case 1:A human corpse was found four months postmortem exposed freely near a railway embankment (suicide, known heroin user). Masses of jumping cheese skipper fly larvae were found on the corpse and bred for identification subsequently. Furthermore, several beetles were found. Case 2: Three months after removal of a corpse found dead for one and a half month in fall/wintertime in a flat, green-blue blowflies and their larvae were seen constantly in the now completely empty, disinfected flat and in a flat being situated in the floor below. Larvae hid behind vertical floor ledges and wall-on-walls made of plaster and rested in diapause until temperature increased.

(GTG)5 allows the distinction between different isolates of the nematode Caenorhabditis elegans.

We have not been able to distinguish different isolates from the nematode Caenorhabditis elegans by morphological means. However, they differ on the molecular level and strains from several geographic regions can be identified with the help of "genetic fingerprints" using the oligonucleotide probe (GTG)5.