A circadian-like gene network programs the timing and dosage of heterochronic miRNA transcription during C. elegans development

Development relies on the exquisite control of both the timing and the levels of gene expression to achieve robust developmental transitions. How cis- and trans-acting factors control both aspects simultaneously is unclear. We show that transcriptional pulses of the temporal patterning microRNA (miRNA) lin-4 are generated by two nuclear hormone receptors (NHRs) in C. elegans, NHR-85 and NHR-23, whose mammalian orthologs, Rev-Erb and ROR, function in the circadian clock. Although Rev-Erb and ROR antagonize each other to control once-daily transcription in mammals, NHR-85/NHR-23 heterodimers bind cooperatively to lin-4 regulatory elements to induce a single pulse of expression during each larval stage. Each pulse's timing, amplitude, and duration are dictated by the phased expression of these NHRs and the C. elegans Period ortholog, LIN-42, that binds to and represses NHR-85. Therefore, during nematode temporal patterning, an evolutionary rewiring of circadian clock components couples the timing of gene expression to the control of transcriptional dosage.

HLH-2/E2A Expression Links Stochastic and Deterministic Elements of a Cell Fate Decision during C. elegans Gonadogenesis

Stochastic mechanisms diversify cell fate in organisms ranging from bacteria to humans [1-4]. In the anchor cell/ventral uterine precursor cell (AC/VU) fate decision during C. elegans gonadogenesis, two "α cells," each with equal potential to be an AC or a VU, interact via LIN-12/Notch and its ligand LAG-2/DSL [5, 6]. This LIN-12/Notch-mediated interaction engages feedback mechanisms that amplify a stochastic initial difference between the two α cells, ensuring that the cell with higher lin-12 activity becomes the VU while the other becomes the AC [7-9]. The initial difference between the α cells was originally envisaged as a random imbalance from "noise" in lin-12 expression/activity [6]. However, subsequent evidence that the relative birth order of the α cells biases their fates suggested other factors may be operating [7]. Here, we investigate the nature of the initial difference using high-throughput lineage analysis [10]; GFP-tagged endogenous LIN-12, LAG-2, and HLH-2, a conserved transcription factor that orchestrates AC/VU development [7, 11]; and tissue-specific hlh-2 null alleles. We identify two stochastic elements: relative birth order, which largely originates at the beginning of the somatic gonad lineage three generations earlier, and onset of HLH-2 expression, such that the α cell whose parent expressed HLH-2 first is biased toward the VU fate. We find that these elements are interrelated, because initiation of HLH-2 expression is linked to the birth of the parent cell. Finally, we provide a potential deterministic mechanism for the HLH-2 expression bias by showing that hlh-2 is required for LIN-12 expression in the α cells.

Glutamate spillover in C. elegans triggers repetitive behavior through presynaptic activation of MGL-2/mGluR5

Glutamate is a major excitatory neurotransmitter, and impaired glutamate clearance following synaptic release promotes spillover, inducing extra-synaptic signaling. The effects of glutamate spillover on animal behavior and its neural correlates are poorly understood. We developed a glutamate spillover model in Caenorhabditis elegans by inactivating the conserved glial glutamate transporter GLT-1. GLT-1 loss drives aberrant repetitive locomotory reversal behavior through uncontrolled oscillatory release of glutamate onto AVA, a major interneuron governing reversals. Repetitive glutamate release and reversal behavior require the glutamate receptor MGL-2/mGluR5, expressed in RIM and other interneurons presynaptic to AVA. mgl-2 loss blocks oscillations and repetitive behavior; while RIM activation is sufficient to induce repetitive reversals in glt-1 mutants. Repetitive AVA firing and reversals require EGL-30/Gαq, an mGluR5 effector. Our studies reveal that cyclic autocrine presynaptic activation drives repetitive reversals following glutamate spillover. That mammalian GLT1 and mGluR5 are implicated in pathological motor repetition suggests a common mechanism controlling repetitive behaviors.

Katz and colleagues examine glutamate spillover effects on C. elegans behaviour. They show that impaired synaptic glutamate clearance in glial glutamate transporter mutants, causes presynaptic mgl-2/mGluR5 activation, generating postsynaptic neural activity oscillations driving repetitive behaviour.

RAB-35 and ARF-6 GTPases Mediate Engulfment and Clearance Following Linker Cell-Type Death

Clearance of dying cells is essential for development and homeostasis. Conserved genes mediate apoptotic cell removal, but whether these genes control non-apoptotic cell removal is a major open question. Linker cell-type death (LCD) is a prevalent non-apoptotic developmental cell death process with features conserved from C. elegans to vertebrates. Using microfluidics-based long-term in vivo imaging, we show that unlike apoptotic cells, the C. elegans linker cell, which dies by LCD, is competitively phagocytosed by two neighboring cells, resulting in cell splitting. Subsequent cell elimination does not require apoptotic engulfment genes. Rather, we find that RAB-35 GTPase is a key coordinator of competitive phagocytosis onset and cell degradation. RAB-35 binds CNT-1, an ARF-6 GTPase activating protein, and removes ARF-6, a degradation inhibitor, from phagosome membranes. This facilitates phosphatidylinositol-4,5-bisphosphate removal from phagosome membranes, promoting phagolysosome maturation. Our studies suggest that RAB-35 and ARF-6 drive a conserved program eliminating cells dying by LCD.

Post-mortem review of fentanyl-related overdose deaths among identified drug users in Southern Bavaria, Germany, 2005-2014

BACKGROUND

Two decades ago, there were only single case reports on deaths in Europe following the consumption of illicitly manufactured fentanyl by problem drug users. Today, lethal fentanyl intoxication is now no longer a rarity. Since 2005, a rapid increase of lethal fentanyl-related intoxications in the drug scene has been observed at the Institute of Legal Medicine, Ludwig Maximilians University, Munich. We hypothesized that this rise is the result of the launch of fentanyl matrix patches in Germany in 2004, their broad acceptance, their diversion from the regulated supply chain, and incautious prescription by medical care providers.

METHODS

Post-mortem toxicological reports were reviewed for lethal fentanyl-related intoxications between 2004 und 2014. Blood and tissue samples were tested by GC/MS or LC-MS/MS. The results of police investigations, autopsy reports, and the database of the Institute of Legal Medicine, LMU, were analysed to identify problem drug users and to detect the source of fentanyl as well as the routes of administration.

RESULTS

Between 2005 and 2014, 242 overdose victims with post-mortem toxicological detection of fentanyl were found. In the majority of cases, fentanyl matrix patches were the source of fentanyl.

CONCLUSION

The onset of fentanyl-related deaths coincided with the launch of transdermal fentanyl matrix patches in Germany in 2004. Several approaches, such as providing drug users with information on the possible risks of fentanyl consumption, education of medical caregivers, and also monitoring of the prescription of fentanyl patches, are required to reduce the number of fentanyl-related deaths in drug addicts.

Concentrations of cyanide in blood samples of corpses after smoke inhalation of varying origin

Cyanide (CN) blood concentration is hardly considered during routine when evaluating smoke gas intoxications and fire victims, although some inflammable materials release a considerable amount of hydrogen cyanide. CN can be significant for the capacity to act and can in the end even be the cause of death. Systematic data concerning the influence of different fire conditions, especially those of various inflammable materials, on the CN-blood concentration of deceased persons do not exist. This study measured the CN level in 92 blood samples of corpses. All persons concerned were found dead in connection with fires and/or smoke gases. At the same time, the carboxyhemoglobin (COHb) level was determined, and the corpses were examined to detect pharmaceutical substances, alcohol and drugs. Furthermore, we analysed autopsy findings and the investigation files to determine the inflammable materials and other circumstances of the fires. Due to the inflammable materials, the highest concentration of CN in the victims was found after enclosed-space fires (n = 45) and after motor-vehicle fires (n = 8). The CN levels in these two groups (n = 53) were in 47 % of the cases toxic and in 13 % of the cases lethal. In victims of charcoal grills (n = 17) and exhaust gases (n = 6), no or only traces of CN were found. Only one case of the self-immolations (n = 12) displayed a toxic CN level. The results show that CN can have considerable significance when evaluating action ability and cause of death with enclosed-space fires and with motor-vehicle fires.

Random Wiring, Ganglion Cell Mosaics, and the Functional Architecture of the Visual Cortex

The architecture of iso-orientation domains in the primary visual cortex (V1) of placental carnivores and primates apparently follows species invariant quantitative laws. Dynamical optimization models assuming that neurons coordinate their stimulus preferences throughout cortical circuits linking millions of cells specifically predict these invariants. This might indicate that V1's intrinsic connectome and its functional architecture adhere to a single optimization principle with high precision and robustness. To validate this hypothesis, it is critical to closely examine the quantitative predictions of alternative candidate theories. Random feedforward wiring within the retino-cortical pathway represents a conceptually appealing alternative to dynamical circuit optimization because random dimension-expanding projections are believed to generically exhibit computationally favorable properties for stimulus representations. Here, we ask whether the quantitative invariants of V1 architecture can be explained as a generic emergent property of random wiring. We generalize and examine the stochastic wiring model proposed by Ringach and coworkers, in which iso-orientation domains in the visual cortex arise through random feedforward connections between semi-regular mosaics of retinal ganglion cells (RGCs) and visual cortical neurons. We derive closed-form expressions for cortical receptive fields and domain layouts predicted by the model for perfectly hexagonal RGC mosaics. Including spatial disorder in the RGC positions considerably changes the domain layout properties as a function of disorder parameters such as position scatter and its correlations across the retina. However, independent of parameter choice, we find that the model predictions substantially deviate from the layout laws of iso-orientation domains observed experimentally. Considering random wiring with the currently most realistic model of RGC mosaic layouts, a pairwise interacting point process, the predicted layouts remain distinct from experimental observations and resemble Gaussian random fields. We conclude that V1 layout invariants are specific quantitative signatures of visual cortical optimization, which cannot be explained by generic random feedforward-wiring models.

Can retinal ganglion cell dipoles seed iso-orientation domains in the visual cortex?

It has been argued that the emergence of roughly periodic orientation preference maps (OPMs) in the primary visual cortex (V1) of carnivores and primates can be explained by a so-called statistical connectivity model. This model assumes that input to V1 neurons is dominated by feed-forward projections originating from a small set of retinal ganglion cells (RGCs). The typical spacing between adjacent cortical orientation columns preferring the same orientation then arises via Moiré-Interference between hexagonal ON/OFF RGC mosaics. While this Moiré-Interference critically depends on long-range hexagonal order within the RGC mosaics, a recent statistical analysis of RGC receptive field positions found no evidence for such long-range positional order. Hexagonal order may be only one of several ways to obtain spatially repetitive OPMs in the statistical connectivity model. Here, we investigate a more general requirement on the spatial structure of RGC mosaics that can seed the emergence of spatially repetitive cortical OPMs, namely that angular correlations between so-called RGC dipoles exhibit a spatial structure similar to that of OPM autocorrelation functions. Both in cat beta cell mosaics as well as primate parasol receptive field mosaics we find that RGC dipole angles are spatially uncorrelated. To help assess the level of these correlations, we introduce a novel point process that generates mosaics with realistic nearest neighbor statistics and a tunable degree of spatial correlations of dipole angles. Using this process, we show that given the size of available data sets, the presence of even weak angular correlations in the data is very unlikely. We conclude that the layout of ON/OFF ganglion cell mosaics lacks the spatial structure necessary to seed iso-orientation domains in the primary visual cortex.

Deaths due to physical restraint

BACKGROUND

Physical restraint is used primarily for patients at risk of falling, those with motor unrest and agitated behavior, and those who manifest an intention of doing harm to themselves or are at risk of suicide. The use of freedom-restraining measures (FRM), and, in particular, the use of physical restraints against the patient's will, can be a serious intrusion of basic human rights and, as such, an act of violence against the patient. The improper use of physical restraints can cause injuries of varying severity, which can sometimes be fatal.

METHODS

We analyzed all cases of death under physical restraint that were recorded in the autopsy reports of the Institute of Forensic Medicine in Munich from 1997 to 2010.

RESULTS

Among the 27 353 autopsies conducted over the period of the study, there were 26 cases of death while the individual was physically restrained. Three of these cases involved patients who died of natural causes while restrained, and one was a suicide. The remaining 22 deaths were caused solely by physical restraint; all of them occurred in patients under nursing care who were not continuously observed. The immediate cause of death was strangulation (11 cases), chest compression (8 cases), or dangling in the head-down position (3 cases). In 19 of these 22 patients, the restraints were incorrectly fastened, including two cases in which improvised non-standard restraints were used. One nursing-home patient died because of an abdominal restraint even though it had been correctly applied: She was mobile enough to slip through the restraint till it compressed her neck, and then unable to extricate herself from it, so that she died of strangulation.

CONCLUSION

To prevent such deaths, we recommend from a forensic medical standpoint that all possible alternatives to FRM should be used instead. If direct-contact restraints are truly necessary, they must be applied as recommended and the restrained person must be closely observed.

Coverage, continuity, and visual cortical architecture

BACKGROUND

The primary visual cortex of many mammals contains a continuous representation of visual space, with a roughly repetitive aperiodic map of orientation preferences superimposed. It was recently found that orientation preference maps (OPMs) obey statistical laws which are apparently invariant among species widely separated in eutherian evolution. Here, we examine whether one of the most prominent models for the optimization of cortical maps, the elastic net (EN) model, can reproduce this common design. The EN model generates representations which optimally trade of stimulus space coverage and map continuity. While this model has been used in numerous studies, no analytical results about the precise layout of the predicted OPMs have been obtained so far.

RESULTS

We present a mathematical approach to analytically calculate the cortical representations predicted by the EN model for the joint mapping of stimulus position and orientation. We find that in all the previously studied regimes, predicted OPM layouts are perfectly periodic. An unbiased search through the EN parameter space identifies a novel regime of aperiodic OPMs with pinwheel densities lower than found in experiments. In an extreme limit, aperiodic OPMs quantitatively resembling experimental observations emerge. Stabilization of these layouts results from strong nonlocal interactions rather than from a coverage-continuity-compromise.

CONCLUSIONS

Our results demonstrate that optimization models for stimulus representations dominated by nonlocal suppressive interactions are in principle capable of correctly predicting the common OPM design. They question that visual cortical feature representations can be explained by a coverage-continuity-compromise.

Analyseebenen und Dateninterdependenz in der Kleingruppenforschung am Beispiel netzbasierter Wissensintegration

Zusammenfassung: In Experimenten mit Kleingruppen fallen Daten auf Person- und Gruppenebene an, die ebenenspezifische Konstrukte und Indikatoren erfordern. Bei einer Analyse auf Person- oder Gruppenebene muss berücksichtigt werden, dass die anfallenden Daten oft nicht unabhängig sind, wobei zugleich die Interdependenz ein sinnvoller und wichtiger Gegenstand der Analyse von Gruppenprozessen ist. In den letzten Jahren sind vermehrt Vorschläge sowohl zur Konzeptualisierung ebenenspezifischer Indikatoren als auch zur statistischen Analyse von Daten aus Experimenten mit interagierenden Gruppen gemacht worden. Am Beispiel eines Experiments zum computer-mediierten Informationsaustausch und zur Informationsintegration in Gruppen wird gezeigt, wie eine inhaltlich sinnvolle Interdependenz von Individuum und Gruppe modelliert und überprüft werden kann. Darüber hinaus werden die Möglichkeiten von Analyseverfahren mit Datenaggregierung oder mit statistischen Methoden, wie etwa gemischten Modellen, diskutiert.

Deaths following methotrexate overdoses by medical staff

Methotrexate (MTX) is an effective disease modifying antirheumatic drug (DMARD) with a relatively safe profile, and it is widely used to treat neoplastic diseases and dermatologic and rheumatologic disorders. As indications for use of MTX increase, more accidental overdoses are noted to occur. Typical problems include deficiencies in labeling, instructions, or packaging, as well as erroneous use. We describe 5 fatal cases of repeated oral overdose of MTX prescribed by physicians in the treatment of rheumatoid arthritis to focus attention on the design of the underlying system and the organizational practices as sources of problems.

Do Centenarians Die Healthy? An Autopsy Study

BACKGROUND

Our goal was to assess the prevalence of common causes of death and the demographic variables in a selected population of centenarians.

METHODS

The autopsy reports and medical histories of all individuals > or =100 years, dying unexpectedly out of hospital, were gathered from 42,398 consecutive autopsies, performed over a period of 18 years at the Institute of Forensic Medicine, Vienna. These records were evaluated with regard to age and sex, circumstances of death, season, time and the cause of death, as well as the presence of any other comorbidity.

RESULTS

Forty centenarians (11 men, 29 women) were identified with a median age of 102 +/- 2.0 (range: 100-108) years. Sixty percent were described as having been healthy before death. However, an acute organic failure causing death was found in 100%, including cardiovascular diseases in 68%, respiratory illnesses in 25%, gastrointestinal disorders in 5%, and cerebrovascular disease in 2%. Additionally, centenarians suffered from several comorbidities (cardiac antecedents, neurologic disorders, liver diseases, cholecystolithiasis), which were not judged to be the cause of death.

CONCLUSIONS

Centenarians, though perceived to have been healthy just prior to death, succumbed to diseases in 100% of the cases examined. They did not die merely "of old age." The 100% post mortem diagnosis of death as a result of acute organic failure justifies autopsy as a legal requirement for this clinically difficult age group.

Patientenfach und elektronisches Rezept

Electronic prescribing shall contribute essentially to improved healthcare services from 2006 onwards in Germany. The desired improvements, however, can only be achieved with "real" telematic solutions. The alternative of pharmaceutical prescription transmission via secure network connections or via electronic health card provides a considerable empowerment to the patients. Electronic prescribing, however, does not provide direct advantages to patients. Benefits for them can be realised by a drug documentation system, ready to identify contraindications or multiple prescriptions. The patients' acceptance of the system to be established therefore largely depends on the concurrent introduction of both elements.

Application of the BioRobot EZ1 in a forensic laboratory

In a forensic laboratory, the routine application of an automated DNA extraction and purification robot has to fulfil several conditions, like producing reproducible DNA's of sufficient quantity and quality from all the different forensic biological stains relevant to various carrier materials. In this study, the suitability of the BioRobot EZ1 system from QIAGEN (Hilden, Germany), which offers fully automated extraction and purification of nucleic acids using magnetic bead technology, was tested. In summary, the DNA's obtained from the BioRobot EZ1 for different forensic relevant biological materials showed a quantity and quality comparable to those of the forensic standard protocols normally used in our laboratory. The system saves time, because there is no need of any further purification or concentration step after the automated DNA extraction. It can also be used as a replacement for time consuming organic extractions. A disadvantage of the system was the unsteady quality of the chemical regencies used by the robot. Nineteen different lots were tested with a self designed test system.

Foreign body asphyxia: a preventable cause of death in the elderly

BACKGROUND

To assess the prevalence of food/foreign body asphyxia in the elderly Viennese population in order to reduce the incidence of these fatal events.

METHODS

This is an autopsy-based, retrospective study in Vienna, Austria. Participants included all nonhospitalized (n =200) cases of choking in 1984 to 2001, from a total 42,745 consecutive autopsies performed at the Institute of Forensic Medicine. In addition, data from hospitalized adult cases of fatal choking (n =73) in 1984 to 2001, from the mortality registrar of Vienna, were included.

RESULTS

The nonhospitalized choking victims were analyzed according to age (18 to 64 vs >/=65 years), sex, circumstances of death, and predisposing factors. Hospitalized cases were analyzed according to age, sex, and whether an autopsy was already performed by pathologists at the institution where they died. In the study period, 273 adults died of food/foreign body asphyxia, 73% of them out of the hospital and 27% in hospitals. Food/foreign body asphyxia in the elderly was characterized by a significantly higher asphyxiation of soft/slick foods (p <0.007) with agomphiasis (p <0.002), occurring most frequently during lunch (49%), and in 2.5% during feeding of neurologically impaired. In contrast, younger individuals choked significantly more often on large pieces of foreign material (p <0.002) and showed a significantly higher rate of blood alcohol concentration (p <0.001).

CONCLUSIONS

This study demonstrates that semisolid foods are the cause of a large number of asphyxiations, especially among the elderly. Knowledge of the fact that semisolid foods are a high-risk factor in elderly individuals should be distributed in public and private healthcare systems, and awareness could be a first step in reducing the incidence of food/foreign body asphyxia.

Textbooks on legal Medicine in the German-speaking Countries

In this survey, the textbooks on legal medicine which were published in the German-speaking countries from the 17th century up to now are briefly reviewed. The textbooks with the most impact on the further development of legal medicines were those published by Johann Ludwig Casper in Berlin and Eduard Ritter von Hofmann in Vienna in the 19th century. The main textbooks of the 20th century are addressed as well, also the different development in both German countries.

Investigation of oral swabs taken from newborn infants after breastfeeding

The aim of this study was to investigate the influence of breastfeeding on the DNA-profiles from oral swabs of newborn babies. Five mother and child pairs were asked to provide orals swabs from the mother and from the child before and immediately after nursing. Investigation of the samples revealed no maternal alleles in the saliva samples of the child taken directly after breast feeding. Therefore, we conclude that nursing does not influence the STR-typing of oral swabs taken form newborn infants. A possible explanation could be that the DNA content of mother's milk is significantly lower than the DNA content of saliva.

Paternity testing using Y-STR haplotypes: assigning a probability for paternity in cases of mutations

In parentage testing with male children, Y-chromosomal STR evidence is gaining more and more importance. In some cases, multilocus haplotypes of related persons can differ at a single locus due to a mutation. In this work, a likelihood approach is presented for the calculation of a probability for paternity under consideration of a single mutation event on the Y-chromosome. The new methodology is applied to two case examples.

Identification of the skeletal remains of Martin Bormann by mtDNA analysis

Contrary to statements of an eye-witness who reported that Martin Bormann, the second most powerful man in the Third Reich, died on 2 May 1945 in Berlin, rumours persisted over the years that he had escaped from Germany after World War II. In 1972, skeletal remains were found during construction work, and by investigating the teeth and the bones experts concluded that they were from Bormann. Nevertheless, new rumours arose and in order to end this speculation we were commissioned to identify the skeletal remains by mitochondrial DNA analysis. The comparison of the sequence of HV1 and HV2 from the skeletal remains and a living maternal relative of Martin Bormann revealed no differences and this sequence was not found in 1,500 Caucasoid reference sequences. Based on this investigation, we support the hypothesis that the skeletal remains are those of Martin Bormann.

Evaluation and application of the AmpF l STR Profiler Plus PCR amplification kit in a Bavarian population sample

Allele frequencies for the nine tetrameric STR loci D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820 were determined in a population sample of 155 unrelated Bavarians using the AmpF/STR Profiler Plus PCR amplification kit. No deviations from the Hardy-Weinberg equilibrium were observed. The influence of the PCR cycle number as well as the template DNA concentration on the performance of the kit was studied. DNA concentrations lower than 75 pg DNA per 25 microliters reaction volume resulted in allelic drop-out.

Y-chromosomal STR haplotypes in a population sample from Bavaria

The seven Y-chromosomal STRs DYS 19, DYS385 I/II, DYS389 I/II, DYS390, DYS391, DYS392 and DYS393 were amplified using two multiplex PCRs. The optimization of the PCR conditions led to reliable and sensitive systems. Co-amplification of the amelogenin locus was possible in both multiplex systems. In a population sample of 151 Bavarian males, a gene diversity of 0.99 was observed. Sensitivity studies revealed a detection limit of 50 pg DNA per 25 microl reaction volume. PCR experiments with combinations of male/male and male/female DNA showed that in male/male mixtures, the minor component could be detected up to a ratio of 1:15, whereas in male/female mixtures the male component could be found in a higher ratio up to 1:60.

The diagnostic significance of haemorrhage of the posterior cricoarytenoid muscles

A number of authors have indicated that haemorrhage of the posterior cricoarytenoid (PCA) muscles can be used as a diagnostic criterion to establish the cause of death. Other authors even consider it to be 'forensic evidence' when differentiating between natural and violent death. They agree on agonal asphyxia or dyspnoea as a developmental mechanism, possibly in combination with a 'convulsive' dilatation of the glottic cleft. In view of this difference of opinion, we conducted a study of our own. Retrospective evaluation of 2060 post-mortem examinations performed in 1996 at the Institute of Forensic Medicine of the University of Munich disclosed 28 cases demonstrating visible haemorrhage of the PCA muscles. The study revealed no correlation between these findings and certain causes of death, nor any indication of certain mechanisms of development.

Hydrocution in a case of Coxsackie virus infection

An apparently healthy 7-year-old boy attempted to demonstrate his ability to dive into a whirlpool but was retrieved from the water in a state of unconsciousness after several minutes. Resuscitation was unsuccessful. No characteristic signs of drowning were found at the autopsy but examination of the lymph nodes and the cardiac muscle indicated a pre-existent infection. The histological examination revealed a slight degree of predominantly lymphocytic infiltration of the cardiac muscle. IgM antibodies against Coxsackie virus were detected in the serum sample by means of ELISA. The reverse transcriptase polymerase chain reaction (RT-PCR) performed on an extract of formalin-fixed, paraffin-embedded cardiac muscle tissue revealed a DNA sequence specific for Coxsackie B3 virus. Therefore, cardiac failure was due to a myocardial virus infection and the additional strain caused by diving. This case report emphasizes the importance of modern molecular biological methods in cases of sudden death including death by hydrocution.

Haemorrhages in the posterior cricoarytenoid muscles--an unspecific autopsy finding

Atraumatic haemorrhages in the posterior cricoarytenoid (PCA) muscles can be observed for from 1% to 9% of various causes of death. It has been claimed that there is an association between these findings and the cause of death, particularly coronary death. Additionally it has been assumed that haemorrhages in the PCA muscles may be caused by an asphyxial mechanism and it has even been suggested that the haemorrhages may be a "sign" which could be used to differentiate between natural and unnatural death. Because of the differing views we carried out additional research into the course of these haemorrhages. Six characteristic cases out of 2060 autopsies with macroscopically diagnosed haemorrhages in the PCA muscles are presented. The six cases included acute heart failure, death caused by bolus, drowning, trauma of brain and skull, exsanguination from polytrauma and choking after aspiration of vomit. These cases were completely different with regard to all the circumstances of death. On the basis of these findings and in contrast to the literature it cannot be shown that proofs exist for a correlation between the haemorrhages and the causes and the manner of death. As a consequence it must be stated that haemorrhages in the PCA muscles do not have any diagnostic significance.

Variations of the frontal exit of the supraorbital nerve: an anatomic study

Until now, it has been taken for granted that the point of emergence of the supraorbital nerve is by way of a notch or a foramen at the border of the inner to the medial third of the supraorbital rim. In contrast to several anatomic textbooks, we noticed that the exit point was repeatedly not at the site where anticipated when implanting lid springs for facial palsy. This gave us the idea of investigating these variations and how big they are, because most open and recent endoscopic forehead lift techniques have relied on a constant exit point of the supraorbital nerve. A total of 507 macerated skulls (1014 orbits) from three anatomic collections in Austria and Germany were studied. All skulls were adult European skulls gathered from the prehistoric age up to the twentieth century. Additionally, 18 fixed cadavers (36 orbits) and 25 fresh cadavers (50 orbits) were studied. These data were not included in the statistical analysis but in the discussion. The anatomic measurements on the skulls were carried out with an anthropometric calliper. The examinations concentrated on the configuration (notch/foramen) and the number of exit point(s) on the supraorbital rim, the vertical distance from the supraorbital rim, and the distance from the nasion to the various exit point(s). Combining all of these parameters, 74 percent of the skulls showed asymmetric findings between the right and left orbits. In 15 percent of both orbits, the supraorbital nerve left the orbital cavity already in its two branches, the medial and lateral branch, either through a notch or a foramen, the foramen being sometimes the exit of a supraorbital canal. The average distance from the nasion to the frontal notch/foramen was 25 mm on both orbits (range 16 to 55 mm) and to the supraorbital notch/foramen 31 mm (range 20 to 49 mm). The largest vertical distance from the supraorbital rim to its farthest exit point was 19 mm. Other than what is cited in literature, the variations concerning the configuration and the distance of the exit point(s) of the supraorbital nerve were so significant that all forehead operations, especially those using endoscopic techniques, must take into account these findings.

DNA typing from stained sperm-positive vaginal smears: four rape cases

DNA typing from stained sperm-positive vaginal smears was performed in four cases of sexual assault. In Cases 1 and 2, a 6-month-old and a 6-week-old, Papanicolaou-stained vaginal smear with 99% propanol fixation underwent DNA analysis respectively. In Case 1, the HLA-DQalpha type of the sperm fraction of the smear was able to be determined following PCR, and the possibility of the suspect being the rapist could not be excluded. In Case 2, the possibility that the suspect was the rapist in the crime was excluded based on the results of DNA typing by means of two different single-locus probes. In the remaining two cases, H-E-stained smears after air drying for 4 or 5 months were the material for DNA analysis, and DNA typing was attempted by PCR-based STR system. In Case 3, there was no genetic information from sperm fraction of the smear due to the small number of spermatozoa on the glass slide. Therefore, it was impossible to determine whether the suspect was the rapist or not. In Case 4, sperm DNA from the smear was amplified and typed, and the suspect could be excluded. These four cases demonstrate that stained vaginal smears containing many spermatozoa can be used for DNA analysis in sexual assault cases.

[Sudden death caused by an arterial hydatid embolism]

HISTORY

A 45-year-old woman from Turkey who had been living in Germany for 6 years, suddenly became short of breath, developed seizures and died within 2 minutes. There was no evidence of previous illness.

INVESTIGATIONS

At autopsy a large hydatid and many other hydatids of varying sizes were found inside the left heart. Rupture of one of the hydatid cysts in the left atrium had caused embolism to the arterial system. The cyst walls showed typical laminar cuticular structure. The sediments of the cyst fluid contained scolices of Echinococcus granulosus, but no antibodies were demonstrated by indirect haemagglutination.

DIAGNOSIS AND CONCLUSION

This is a rare case of Echinococcus granulosus infection, limited to the heart, which had followed an asymptomatic course until sudden death caused by arterial embolism of the hydatids. Such diagnosis should be considered in case of sudden death of persons from areas in which the disease is endemic.

Evaluation of MHS-5 in detecting seminal fluid in vaginal swabs

Vaginal swabs taken in 211 cases of alleged sexual assault were examined for seminal vesicle-specific antigen (SVSA) using an MHS-5-ELISA (SEMA kit). The results were compared with those obtained by sperm detection by means of light microscopy and the acid phosphatase reaction (ACP), using Phosphatesmo-KM papers. Especially in fresher samples (duration of storage between 10 days and 2 1/2 months), a high degree of correlation was observed between the results of light microscopic and MHS-5 methods. Several cases with positive MHS-5 showed concurrent positive ACP reactions, even though no spermatozoa had been seen microscopically. The results are displayed in the light of time elapsed between the alleged assault and examination of the swabs. The longest time span after the alleged assault in which MHS-5 yielded a positive result was 47 h; in this case spermatozoa were also seen microscopically. SVSA is not totally stable in vaginal swabs stored over long (9 months to 5 1/2 years) periods of time. Furthermore, results in eight penile swabs are reported. MHS-5 is a useful tool for medico-forensic semen detection in vaginal swabs, probably even in cases of azoospermic or aspermia.

Recombinant human Fab antibody fragments to HIV-1 Rev and Tat regulatory proteins: direct selection from a combinatorial phage display library

A human Fab phage display library has been produced from peripheral blood lymphocytes of an individual who was asymptomatic after 10 years of infection with human immunodeficiency virus type-1 (HIV-1). The library was panned against the HIV-1 Rev and Tat regulatory proteins and several clones, producing Fab binding to these proteins, were isolated (3 to Rev and 4 to Tat) with binding constants varying from 10(-6)M to 10(-8)M. DNA sequencing demonstrated two unique anti-Rev Fab clones, but the four anti-Tat Fab comprised only two unique IgG1 heavy chain Fd fragments, illustrating redundancy of light chains. Peptide mapping of the epitopes recognized by these Fab indicated that three of the anti-Tat Fab were directed to the functional domain between amino acid residues 22-33 of the Tat molecule, and that binding was inhibited by reduction of this cysteine-rich region with dithiothreitol. The anti-Rev Fab were directed to sites adjacent to the Rev basic nucleolar localization sequence (residues 52-64) and to the Rev activation domain (residues 75-88). Binding constants were of a similar order to that of an anti-Rev single-chain Fv fragment (SFv) used successfully for intracellular immunization, and as such intracellular effects with the human anti-Tat and anti-Rev Fab are not precluded. These newly described human antibody fragments to HIV-1 regulatory proteins may be critical moieties for gene therapeutic protocols, to control HIV-1 replication in human cells.

Characterization of haemorrhages at the origin of the sternocleidomastoid muscles in hanging

Haemorrhages at the periostal-clavicular origin of the sternocleidomastoid muscles were found in 52 out of 54 cases of death by hanging. This cervical haemorrhage is most frequently found in death by hanging, but only seldomly seen in other causes of death and can therefore be regarded as being typical for death by hanging. The frequency of this finding on the side of the highest point of the ligature mark is significantly higher, thereby supporting the hypothesis of extension as the causative mechanism. External cardiac massage and assisted breathing have no influence on the occurrence of haemorrhages. Histology shows the haemorrhages to be mainly directly epiperiostal, however, many cases displayed concurrent sub- and intraperiostal extravasations. Artificial post mortem production of these findings is discussed in the light of the literature.

[Self-castration with suicide]

Suicide of a 31 year old man with multiple slashes and stab wounds including complete amputation of penis, scrotum and testicles is reported. Wound patterns in genital self-mutilations are discussed. Despite serious loss of blood the reported survival periods are remarkable; death from bleeding seems to be rare. A review of similar cases shows that self-castrations as well as other self-inflicted genital mutilations are usually associated with psychiatric disorders and transsexuality or hypersexuality.

The detection of petechial haemorrhages of the conjunctivae in dependency on the postmortem interval

Petechial haemorrhages of the conjunctivae are not specific for lethal throttling or strangulation, but they belong to the important indicators for such mechanisms. In experimental models it is shown that petechial bleedings of the conjunctivae disappear with the occurrence of advanced signs of putrefaction or in cases of fresh-water logging. Therefore, it must be emphasized that the lack of petechial haemorrhages in putrefied or fresh-water-logged corpses is of very restricted meaning for the examination, whether throttling or strangulation has taken place or not, and the autopsy should always be performed in these cases with special regard to the neck.

Disulfide-bonded discontinuous epitopes on the glycoprotein of vesicular stomatitis virus (New Jersey serotype)

Intrachain disulfide bonds between paired cysteines in the glycoprotein (G) of vesicular stomatitis virus (VSV) are required for the recognition of discontinuous epitopes by specific monoclonal antibodies (MAbs) (W. Keil and R. R. Wagner, Virology 170:392-407, 1989). Cleavage by Staphylococcus aureus V8 protease of the 517-amino-acid VSV-New Jersey G protein, limited to the glutamic acid at residue 110, resulted in a protein (designated GV8) with greatly retarded migration by polyacrylamide gel electrophoresis (PAGE) under nonreducing conditions. By Western blot (immunoblot) analysis, protein GV8 was found to lose discontinuous epitope IV, which maps within the first 193 NH2-terminal amino acids. These data, coupled with those obtained by PAGE migration of a vector-expressed, truncated protein (G1-193) under reducing and nonreducing conditions, lead us to postulate the existence of a major loop structure within the first 193 NH2-terminal amino acids of the G protein, possibly anchored by a disulfide bond between cysteine 108 and cysteine 169, encompassing epitope IV. Site-directed mutants in which 10 of the 12 cysteines were individually converted to serines in vaccinia virus-based vectors expressing these single-site mutant G proteins were also constructed, each of which was then tested by immunoprecipitation for its capacity to recognize epitope-specific MAbs. These results showed that mutations in NH2-terminal cysteines 130, 174, and, to a lesser extent, 193 all resulted in the loss of neutralization epitope VIII. A mutation at NH2-terminal cysteine 130 also resulted in the loss of neutralization epitope VII, as did a mutation at cysteine 108 to a lesser extent. Both epitopes VII and VIII disappeared when mutations were made in COOH-distal cysteine 235, 240, or 273, the general map locations of epitopes VII and VIII. These studies also reveal that distal, as well as proximal, cysteine residues markedly influence the disulfide-bond secondary structure, which ostensibly determines the conformational structure of the VSV-New Jersey G protein required for presentation of the major discontinuous epitopes recognized by neutralizing MAbs.

Newly synthesized class II MHC chains are required for VSV G presentation to CTL clones

Mechanisms of antigen processing and presentation to thymus-derived lymphocytes have been under intense study for several years, focusing on both Class I-restricted antigen presentation and Class II-MHC restricted responses. The studies described here examine the processing and presentation of exogenously provided soluble glycoprotein of the vesicular stomatitis virus and as well as newly synthesized viral glycoprotein. Evidence is provided that newly synthesized Class II MHC chains are required for cell surface expression of processed glycoprotein determinants irrespective of the origin of the viral antigen. Inhibitors of distinct cellular processes, including ammonium chloride, emetine, and Brefeldin A, have been used to dissect the pathways utilized.