Magnetic resonance imaging of regional gray matter volume in persons who died by suicide.

In vivo neuroimaging research in suicide attempters has shown alterations in frontal system brain regions subserving emotional regulation, motivation, and self-perception; however, data from living individuals is limited in clarifying risk for suicide death. Postmortem neuroimaging provides an approach to study the brain in persons who died by suicide. Here, whole brain voxel-based analyses of magnetic resonance imaging gray matter volume measures were performed comparing persons confirmed by forensic investigation to have died by suicide (n = 24), versus other causes (n = 24), in a univariate model covarying for age and total brain volume; all subjects were scanned within 24 hours after death. Consistent with the hypothesis that persons who died by suicide would show lower gray matter volume in frontal system brain regions, this study of suicides showed lower gray matter volume in ventral frontal and its major connection sites including insula, striatum, and amygdala.

Fracture energy threshold in parry injuries due to sharp and blunt force.

Blows with axes, machetes or blunt objects such as baseball bats, truncheons, etc. are often parried, resulting in typical parry injuries, or so-called nightstick fractures to the ulna. In this study, we sought to assess the impact energy required to break the ulna in such parry incidents in an experimental setting using semisynthetic and fully synthetic models. Twenty-seven sheep radii and 33 polyurethane synthetic bones were cast into gelatin prior to being fired at with missiles made of a section of an axe blade or steel rod at different firing velocities using a compressed-nitrogen cannon. Each model was then examined as to the presence of hair-line fractures or complete fractures. Sheep bones and synthetic bones displayed comparable results when struck by the axe missile; here, a clear fracture threshold was evident between 14.00 and 15.26 J. When struck by the rod missile, only the synthetic bones produced significant results, namely a fracture threshold between 20.15 and 23.59 J. In conclusion, our results show an ulnar fracture threshold of approximately 15 J when struck by an axe. The experiments regarding blows with a rod displayed a fracture threshold of around 22 J, but, as this could not be validated with biological bones, this result is questionable.

Estimating the postmortem interval of human skeletal remains by analyzing their fluorescence at 365 and 490 nm.

The study presented here is regarded as a continuation of the experiments of Sterzik et al., who developed a new practical method to distinguish between historical and recent human skeletal remains. Bone cross-sections were illuminated using light with wavelengths of 365 and 490 nm, causing fluorescence. The fluorescence was documented by photography and further analyzed to examine the areal extent of a certain fluorescent color. Contrary to the previous experiments of Sterzik et al., the present study focused on bones with postmortem intervals (PMIs) ≥ 50 years. Therefore, this study fills the gap created by the former study, pointing towards a correlation between the PMI and the areal extent of the fluorescent surface in both tests. The presence of blue and red fluorescent surfaces < 1% indicated a PMI ≥ 50 years. Furthermore, the presence of blue and red fluorescent surfaces > 1% can be regarded as a marker to exclude a PMI ≥ 50 years; in fact, these bones are likely to have a PMI < 30 years.

CT metal artefact reduction for internal fixation of the proximal humerus: value of mono-energetic extrapolation from dual-energy and iterative reconstructions.

AIM: To assess the value of dual-energy computed tomography (DECT) and an iterative frequency split-normalized metal artefact reduction (IFS-MAR) algorithm compared to filtered back projections (FBP) from single-energy CT (SECT) for artefact reduction in internally fixated humeral fractures. MATERIALS AND METHODS: Six internally fixated cadaveric humeri were examined using SECT and DECT. Data were reconstructed using FBP, IFS-MAR, and mono-energetic DECT extrapolations. Image analysis included radiodensity values and qualitative evaluation of artefacts, image quality, and level of confidence for localizing screw tips. RESULTS: Radiodensity values of streak artefacts were significantly different (p < 0.05) between FBP (-104 ± 222) and IFS-MAR (73 ± 122), and between FBP and DECT (32 ± 151), without differences between IFS-MAR and DECT (p < 0.553). Compared to FBP, qualitative artefacts were significantly reduced using IFS-MAR (p < 0.001) and DECT (p < 0.05), without significant differences between IFS-MAR and DECT (p < 0.219). Image quality significantly (p = 0.016) improved for IFS-MAR and DECT compared to FBP, without significant differences between IFS-MAR and DECT (p < 0.553). The level of confidence for screw tip localization was assessed as best for DECT in all cases. CONCLUSION: Both IFS-MAR in SECT and mono-energetic DECT produce improved image quality and a reduction of metal artefacts. Screw tip positions can be most confidently assessed using DECT.

Temperature-induced sex reversal is not responsible for sex-ratio distortions in grayling Thymallus thymallus or brown trout Salmo trutta.

On the basis of the experiments carried out over various years, it was concluded that (1) grayling Thymallus thymallus and brown trout Salmo trutta are resistant to temperature-induced sex reversal at ecologically relevant temperatures, (2) environmental sex reversal is unlikely to cause the persistent sex ratio distortion observed in at least one of the study populations and (3) sex-specific tolerance of temperature-related stress may be the cause of distorted sex ratios in populations of T. thymallus or S. trutta.

Annular distribution patterns of .357 Magnum fragments in soft tissue simulants after striking hard material that prevented the bullet from exiting.

The distribution of bullet fragments inside the body can provide information for the reconstruction of events in shooting incidents. The formation of an annular distribution pattern of bullet fragments was recently presented in a case report. The fragments were scattered radially around an exit-re-entrance wound resulting from collision of the bullet with a floor tile immediately after perforating the body. Such an annular distribution pattern of bullet fragments around an exit-re-entrance wound would indicate that a body was in close contact with hard material, for instance, lying on hard ground or leaning against a concrete wall, when the shot was fired. The aim of this experimental study was to investigate the formation and reproducibility of the annular distribution pattern of bullet fragments. It was assumed that the distribution pattern would be formed when hard material blocks a bullet from exiting a soft tissue simulant. Furthermore, the dependency of this distribution pattern on the impact angle was assessed. For this purpose, .357 Magnum bullets were fired at ballistic soap blocks with a steel plate at the rear end of the soap block. Six shots were performed at an impact angle of 90° (experiment 1), and six shots were performed at an impact angle of 45° (experiment 2). The distribution pattern of the fragments inside the individual soap blocks was examined via computed tomography (CT). In experiment 1, the bullets burst, and large fragments formed annular distribution patterns with a radial extent of approximately 4.9 cm and a maximum depth of approximately 2.3 cm. In experiment 2, the bullets ricocheted from the steel plate, and tiny fragments formed small annular distribution patterns at the points of ricochet with a radial extent of approximately 1.5 cm and a maximum depth of approximately 1.2 cm. The end position of the large main fragments was approximately 9.7 cm distant from the point of ricochet at a mean depth of 2.7 cm. The mean kinetic energy of the bullets at the time of impact was 580 J in experiment 1 and 394 J in experiment 2. Distribution patterns of bullet fragments in the body may provide information not only on the impact angle of a bullet but also on whether the body was in contact with a hard material that blocked the bullet from exiting the body. CT proved to be an appropriate imaging method for such investigations.

[Virtual autopsy (virtopsy) in forensic science: from the scalpel to the scanner]. / Virtuelle Autopsie (Virtopsy) in der Forensik: Vom Skalpell zum Scanner.

The aim of "virtopsy" is to utilize modern imaging technology to optimize classical autopsy documentation. The benefits of virtopsy include examiner-independent, objective 3D documentation and its non-invasive approach. Virtopsy is an option in cases where autopsy is rejected by family members or for religious reasons. It is also suitable as a rapid identification and examination tool in large-scale disasters. Forensic findings can be presented to prosecutors and courts in 3D and without bloody images.

Evaluation of an acetated Ringer-based contrast material mixture for postmortem computed tomography angiography.

PURPOSE: The purpose of this study was to compare an established postmortem contrast medium mixture based on polyethylene glycol (PEG) to an isotonic crystalloid with acetated Ringer solution (AR) as the base, both mixed with water-soluble iodinated contrast medium for postmortem computed tomography angiography (PMCTA) with the aim to avoid alterations of the corpse during autopsy. MATERIALS AND METHODS: The study included 20 cadavers; 10 had PMCTA with AR and 10 with PEG. PMCTA images were analyzed with respect to image quality, vascular contrast patterns and artifacts. Autopsy was evaluated for visual, organ, vessel and haptic alterations. The Wilcoxon rank sum test was used to search for differences in image quality between the two groups. Statistical significance was set at P<0.05. RESULTS: AR provided excellent contrast within the right coronary artery (P<0.001) but a lack of contrast within the left coronary artery (P=0.008) whereas PEG showed the opposite. A better image quality was observed in the PEG group by comparison with the AR group for right common carotid artery (P=0.03), left common carotid artery (P=0.01) and left coronary artery (P=0.008). No differences were found for ascending aorta (P=0.65), aortic arch (P=0.09), right circle of Willis (P=0.17), left circle of Willis (P=0.08), inferior vena cava (P=0.07) and abdominal aorta (P=0.08). Severe extravasation occurred in all (10/10; 100%) cadavers in the AR group but in none (0/10; 0%) in the PEG group (P<0.001). At autopsy, visual alteration with lilac discoloration of the face was observed in 4/10 cadavers (40%) in the AR group and in 9/10 cadavers (90%) in the PEG group (P=0.057). Haptic alterations were observed in 3/10 cadavers (30%) in the AR group and 10/10 cadavers (100%) in the PEG group (P=0.003). CONCLUSION: AR results in contrast medium mixture extravasation in all cadavers, but PEG altered the autopsy more severely. Both carrier substances result in specific substance-related artifacts and dependent opacification of the coronary arteries, but PEG is recommended for PMCTA exclusively with regard to diagnostic imaging.

Virtopsy: fatal stab wounds to the skull--the relevance of ante-mortem and post-mortem radiological data in case reconstructions.

Homicides with a survival of several days are not uncommon in forensic routine work. Reconstructions of these cases by autopsy alone are very difficult and may occasionally lead to unsatisfying results. For the medico-legal reconstruction of these cases, ante-mortem and post-mortem radiological imaging should always be included in the expertise. We report on a case of fatal penetrating stab wounds to the skull in which a case reconstruction was only possible by combining the radiological ante- and post-mortem data with the autopsy findings.

A fully synthetic lung model for wound-ballistic experiments-First results.

PURPOSE: Today, synthetic models have all but replaced animal and corpse models in examining damage to soft-tissues and skeletal structures by ballistic trauma. As, however, non-solid organs such as the lungs, have not been able to be replaced by a fully synthetic model we attempted to create such a model. MATERIAL AND METHODS: 20% ordnance gelatine was frothed with a household mixer and cooled to stable foam. Several of these foam blocks were then stuck together with liquid gelatine and placed between 10% gelatine blocks. As controls, we embedded pig lungs in gelatine and compared the wound channels seen in computed tomography created upon shooting with 9mm Luger. RESULTS: The fully synthetic models displayed radiological and physical densities comparable to real lungs. The wound profile characteristics of the fully synthetic lung models were very similar to the semisynthetic swine-gelatine models regarding the permanent wound cavity. Furthermore, in both semi- and fully synthetic models we detected a ring surrounding the permanent wound channel, most likely representing the remnants of the temporary wound cavity. CONCLUSION: Our results indicate that this fully synthetic lung model is a viable substitute for ballistic experiments on lungs. We believe that further research on the temporary wound channel in lungs is possible with this model in order to provide more insight into the effect of ballistic trauma to the lungs not seen otherwise.

Line-scan diffusion tensor imaging of the posttraumatic brain stem: changes with neuropathologic correlation.

Following trauma, imaging of brain stem lesions is often inconclusive. In a man who suffered a lethal accident, postmortem MR diffusion tensor (DT) imaging of the brain and neuropathologic examination were performed. DT imaging showed a disorganization of fibers in the brain stem that was not found in 2 controls and corresponded to changes on neuropathologic correlation. Diffusion tensor imaging provides an insight into the organization of myelinated structures of the CNS, potentially allowing diagnosis of traumatic fiber tract rupture.

Immediate early protein of pseudorabies virus is a general transactivator but stimulates only suboptimally utilized promoters. A clue to specificity?

Pseudorabies virus, a herpesvirus, encodes an immediate early (IE) protein that is known to be a general and strong transactivator of transcription. We have tested the activity of this IE protein with a set of well-defined promoters containing a TATA box and one type of upstream factor binding site (for Sp1, NF-kappa B, heavy metal responsive factors, octamer factors or glucocorticoid receptor). All promoters were strongly activated by IE protein, i.e. the IE protein did not preferentially activate transcription via a particular type of upstream element. Activation did not require a bona fide TATA box, since a promoter construct with three Sp1 sites but no TATA box was also activated. Our data are not compatible with a model in which IE protein would bypass the need for upstream factors. Rather, the properties of IE protein, especially a failure to induce strong transcription from a promoter with only a TATA box but no upstream sequences, mimic the action of a remotely placed, cis-active, enhancer DNA. The IE protein was found to have no effect on transcription units that are expressed to their maximal potential, irrespective of whether this was high or low. Such optimal transcription conditions are observed in the presence of a strong enhancer, or with multiple tandem copies of an upstream binding site and/or a high concentration of the corresponding factor. The property of stimulating only "suboptimally" utilized promoters may be exploited by pseudorabies virus to restrict the specificity of the IE protein to the viral early promoters and a subset of cellular promoters.

Further characterization of an antigenic site of HIV-1 gp120 recognized by virus neutralizing human monoclonal antibodies.

OBJECTIVE: The aim of this study is to characterize antigenic sites on HIV-1 gp120 which may be important for the development of active and passive immunization strategies against HIV-1 infection. DESIGN: Two HIV-1-seropositive individuals were selected from the Amsterdam cohort and Epstein-Barr virus (EBV)-transformed B cells were generated from their peripheral blood mononuclear cells, which produce HIV-1-specific human monoclonal antibodies (HuMAb). METHODS: HuMAb were generated and selected based on their reactivities with native gp120. Reactivity with HIV-1 strains from phylogenetically different subfamilies was determined by immunostaining and virus neutralization assays. Specificity for the CD4-binding site was tested by an inhibition enzyme-linked immunosorbent assay and amino acids (aa) involved in the binding of the HuMAb were identified with a set of gp120 molecules with single aa substitutions. RESULTS: Three HuMAb (GP13, GP44, GP68) were generated, all recognizing a conserved conformation dependent epitope within, or topographically near, the CD4-binding site of gp120. HuMAb GP13 and GP68 neutralized a broad range of HIV-1 strains from phylogenetically different subfamilies, whereas HuMAb GP44 exhibited a more restricted pattern of neutralizing activity. The patterns of gp120 aa involved in their binding were unique for each of these HuMAb. CONCLUSIONS: The pattern of reactivities of these three HIV-1-neutralizing HuMAb developed in these studies is similar to, but distinct from other human and rodent MAb that recognize this antigenic site of HIV-1 gp120.

Stable transduction with lentiviral vectors and amplification of immature hematopoietic progenitors from cord blood of preterm human fetuses.

Umbilical cord blood (CB) from the early gestational human fetus is recognized as a rich source of hematopoietic stem cells. To examine the value of fetal CB for gene therapy of inborn immunohematopoietic disorders, we tested the feasibility of genetic modification of CD34(+) cells from CB at weeks 24 to 34 of pregnancy, using lentiviral vector-mediated transfer of the green fluorescent protein (GFP) gene. The transduction rate of CD34(+) cells was 42 +/- 9%, resulting in GFP expression in 23 +/- 4% of colonies derived from colony-forming units (CFUs) and 11 +/- 1% from primitive long-term culture-initiating cells (LTC-ICs). Cell cycle analysis demonstrated transduction and GFP expression in cells in the G(0) phase, which contains immature hematopoietic progenitors. Transduced fetal CD34(+) cells could be expanded 1000-fold in long-term cultures supplemented with megakaryocyte growth and development factor along with Flt-3 ligand. At week 10, expression of GFP was observed in 40.5 +/- 11.7% of CFU-derived colonies. While prestimulation of CD34(+) cells with cytokines prior to transduction increased the efficiency of GFP transfer 2- to 3-fold, long-term maintenance of GFP-expressing CFUs occurred only in the absence of prestimulation. The GFP gene was found integrated into the genomic DNA of 35% of LTC-IC-derived colonies initiated at week 10, but GFP expression was not detectable, suggesting downregulation of transgene activity during the extended culture period. These results indicate that human fetal CB progenitors are amenable to genetic modification by lentiviral vectors and may serve as a target for gene therapy of hematopoietic disorders by prenatal autologous transplantation.

Contribution of disulfide bonds in the carboxyl terminus of the human immunodeficiency virus type I gp120 glycoprotein to CD4 binding.

The carboxyl half of the HIV-1 gp120 glycoprotein, which has been implicated in binding to the CD4 receptor, contains two disulfide bonds linking cysteine residues 378-445 and 385-418. To examine the necessity of these disulfide bonds for the formation and/or maintenance of a gp120 glycoprotein competent for CD4 binding, we created mutants of a soluble form of gp120 in which combinations of these cysteine residues were altered. The mutant glycoproteins were examined for export from the expressing cell and for CD4 binding ability. Mutant gp120 molecules lacking both disulfide bonds were not stably expressed or exported. However, mutants for which either disulfide bond could form were exported and were fully competent for CD4 binding. In some cases, the presence of one of the pair of linked cysteines exerted more detrimental effects on export or CD4 binding than did alteration of both cysteines. Thus, the evaluation or the contribution of a particular disulfide bond to a phenotype should include studies in which both cysteines involved in the bond are simultaneously altered.

Cooperativity of neutralizing antibodies directed against the V3 and CD4 binding regions of the human immunodeficiency virus gp120 envelope glycoprotein.

Human immunodeficiency virus type 1 (HIV-1) infection elicits neutralizing antibodies directed against two discrete regions of the gp120 exterior envelope glycoprotein: the third variable (V3) loop and the CD4 binding region. Monoclonal antibodies directed against these two regions demonstrated additive or, in some cases, weakly synergistic neutralization of HIV-1 infection. Cooperativity in virus neutralization was also observed for some gp120 mutants that, in the absence of anti-V3 loop antibodies, were relatively resistant to neutralization by antibodies directed against the CD4 binding region. Although the binding of some anti-V3 region monoclonal antibodies increased the recognition of the multimeric envelope glycoproteins by anti-CD4 binding antibodies, this enhanced binding was not predictive of the degree of cooperativity observed in virus neutralization. These results suggest that elicitation of both types of neutralizing antibodies should increase the efficacy of vaccine preparations.

Is 'virtual histology' the next step after the 'virtual autopsy'? Magnetic resonance microscopy in forensic medicine.

AIM: The study aimed to validate magnetic resonance microscopy (MRM) studies of forensic tissue specimens (skin samples with electric injury patterns) against the results from routine histology. METHODS AND RESULTS: Computed tomography and magnetic resonance imaging are fast becoming important tools in clinical and forensic pathology. This study is the first forensic application of MRM to the analysis of electric injury patterns in human skin. Three-dimensional high-resolution MRM images of fixed skin specimens provided a complete 3D view of the damaged tissues at the site of an electric injury as well as in neighboring tissues, consistent with histologic findings. The image intensity of the dermal layer in T2-weighted MRM images was reduced in the central zone due to carbonization or coagulation necrosis and increased in the intermediate zone because of dermal edema. A subjacent blood vessel with an intravascular occlusion supports the hypothesis that current traveled through the vascular system before arcing to ground. CONCLUSION: High-resolution imaging offers a noninvasive alternative to conventional histology in forensic wound analysis and can be used to perform 3D virtual histology.

The evaluation of a synthetic long bone structure as a substitute for human tissue in gunshot experiments.

Our goal was to compare experimental gunshot wounds in our non-biological bone model with similarly created wounds in swine bones, and evaluate the results. The design of the synthetic (polyurethane) bone was patterned after human bone structure, with a compact outer layer covering a porous inner layer. Ordnance gelatin, as substitute bone marrow, was injected into the bone's hollow core. To simulate the periostium, the bone was covered with a layer of latex. Then the bone was embedded in gelatin used to simulate surrounding soft tissue. For comparison, fresh swine bones were also embedded in gelatin, and fired upon under the same guidelines. All gunshots were high-speed filmed. In our experimental study, gunshot wounds to swine bones, and to our synthetic, non-biological bones were compared. The results (the comparison between the biological swine bones and the non-biological model bones) in regard to the following points are absolutely equal: the loss of velocity and energy after striking bone, bone fragmentation, bullet deformation, and the penetrating wound channel. Continuing studies with our synthetic bone model will bring about an even greater understanding of the mechanisms of "bullet-bone interaction". For this reason, we have extended our variety of bone models to include other skeletal structures such as skull, spine, pelvis and flat bones for further gunshot experiments.

Gunshot residue patterns on skin in angled contact and near contact gunshot wounds.

The goal of this study was the reproduction of shape and pattern of gunshot residues in near contact and contact gunshot wounds by a series of experimental gunshots on a skin and soft tissue model. The aim was to investigate the shape and direction of soot deposits with regard to the muzzle according to different muzzle-target angles, firing distances, type of ammunition and weapon and barrel length. Based on a review of the literature and on the results of the experiments the authors could make the following statements of gunshot residues in angled contact and close contact gunshot: (1) gunshot residues on the target surface can be differentiated in a "inner" and "outer powder soot zone"; (2) the outer powder soot zone is much less visible than the inner powder soot zone and may lack on human skin; (3) with increasing muzzle target distance both inner and outer powder soot halo increase in size and decrease in density; (4) in angled shots the inner powder soot halo shows an eccentric, elliptic shape which points towards the muzzle, regardless of ammunition, calibre and barrel length; (5) the outer powder soot points away from the muzzle in angled contact and close contact shots.