Immer wieder wird in Ordnungswidrigkeitenverfahren behauptet, dass eine positive Atemalkoholmessung nicht durch das Trinken von alkoholhaltigen Getränken, sondern durch die Aufnahme anderer Substanzen zu erklären sei. Aus gegebenem Anlass war zu klären, ob das Dampfen von E‑Zigaretten geeignet ist, ein positives Messergebnis hervorzurufen.
Medico-legal experts are increasingly enlisted to assess the methamphetamine and amphetamine serum concentrations after a criminal offense. However, since criminal users rarely provide useful information to medico-legal experts regarding the substances abused, when the substance(s) was/were used, dose of ingestion tools are needed to interpret the analytical data, which can be used as objective evidence in such cases. A comparative series of methamphetamine and amphetamine serum concentrations were used to analyze the frequency of concentrations, to determine methamphetamine/amphetamine concentration ratios, and prove them as a tool to distinguish pure methamphetamine from mixed amphetamine/methamphetamine ingestion. Additionally, two cases of survived accidental methamphetamine intoxication, resulting from ingestion smuggling which was longitudinally monitored, and pharmacokinetic parameters were assessed. In a series of 628 samples where the most frequent concentration of methamphetamine exceeded the therapeutic level, there was a strong correlation suggesting pure methamphetamine consumption, when the ratios of methamphetamine/amphetamine concentrations were within the range between 3 and 10. In the two cases of methamphetamine bodypacking, the relevant serum concentrations of methamphetamine and amphetamine, which could be measured up to 9 days after ingestion, indicated a decrease of the methamphetamine/amphetamine ratios in an exponential manner. However, the ratios were not always within the range between 3 and 10. Lastly, the course of the serum concentrations suggested an increase of the apparent elimination half-life of methamphetamine. In terms of the objective evidence required in criminal law, calculating methamphetamine/amphetamine concentration ratio is not a suitable to means to distinguish pure methamphetamine intake and that of mixed amphetamine/methamphetamine abuse in an individual case. Instead, methamphetamine high serum concentrations and the possible increase in apparent elimination half-life suggest that an extended detection period may be used to distinguish between “illicit use” as compared to “therapeutic use” of methamphetamine.
Background: Adult neurogenesis has been shown to occur throughout life and different brain pathologies were demonstrated to be associated with altered neurogenesis. Here, an impact of heroin addiction on neurogenesis in humans is hypothesised.Methods: Post mortem hippocampal specimens of drug addicts with known heroin abuse and a group of non-addictive control subjects were analysed, using antibodies indicating different stages of neurogenesis. The subgranular zone of the dentate gyrus was examined qualitatively and quantitatively.Results: The data indicate (i) a decreased number of neural precursor cells, (ii) accompanied by low rates of proliferation and (iii) a marked loss of dendritic trees in targeting cells in heroin fatalities. (iv) The age-dependent increase of differentiating cells in the healthy controls was not observed in the addicts. Additionally, double immunofluorescence labelling indicated the precursor nature of Musashi-1 positive cells in the human subgranular zone of the dentate gyrus.Conclusions: Present data firstly demonstrate the influence of drug addiction with known heroin abuse on different developmental stages of progenitors in the dentate gyrus. The patterns of antibody staining suggest a distinct inhibition of neurogenesis at the stage of neural precursor cells and revealed morphological changes in targeting cells in cases of heroin addicts as compared to healthy controls. These alterations could be considerable for memory and cognitive deficits as well as addictive behaviour in chronic drug abusers and may give rise to specific pro-neurogenic therapies. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
Drug addiction is a chronic, relapsing disease caused by neurochemical and molecular changes in the brain. In this human autopsy study qualitative and quantitative changes of glial fibrillary acidic protein (GFAP)-positive astrocytes in the hippocampus of 26 lethally intoxicated drug addicts and 35 matched controls are described. The morphological characterization of these cells reflected alterations representative for astrogliosis. But, neither quantification of GFAP-positive cells nor the Western blot analysis indicated statistical significant differences between drug fatalities versus controls. However, by semi-quantitative scoring a significant shift towards higher numbers of activated astrocytes in the drug group was detected. To assess morphological changes quantitatively, graph-based representations of astrocyte morphology were obtained from single cell images captured by confocal laser scanning microscopy. Their underlying structures were used to quantify changes in astroglial fibers in an automated fashion. This morphometric analysis yielded significant differences between the investigated groups for four different measures of fiber characteristics (Euclidean distance, graph distance, number of graph elements, fiber skeleton distance), indicating that, e.g., astrocytes in drug addicts on average exhibit significant elongation of fiber structures as well as two-fold increase in GFAP-positive fibers as compared with those in controls. In conclusion, the present data show characteristic differences in morphology of hippocampal astrocytes in drug addicts versus controls and further supports the involvement of astrocytes in human pathophysiology of drug addiction. The automated quantification of astrocyte morphologies provides a novel, testable way to assess the fiber structures in a quantitative manner as opposed to standard, qualitative descriptions.
Unveiling the mechanisms participating in the damage and repair of traumatic brain injury (TBI) is fundamental to develop new therapies. The P2Y-like GPR17 receptor has recently emerged as a sensor of damage and a key actor in lesion remodeling/repair in the rodent brain, but its role in humans is totally unknown. Here, we characterized GPR17 expression in brain specimens from seven intensive care unit TBI patients undergoing neurosurgery for contusion removal and from 28 autoptic TBI cases (and 10 control subjects of matched age and gender) of two university hospitals. In both neurosurgery and autoptic samples, GPR17 expression was strong inside the contused core and progressively declined distally according to a spatio-temporal gradient. Inside and around the core, GPR17 labeled dying neurons, reactive astrocytes, and activated microglia/macrophages. In peri-contused parenchyma, GPR17 decorated oligodendrocyte precursor cells (OPCs) some of which had proliferated, indicating re-myelination attempts. In autoptic cases, GPR17 expression positively correlated with death for intracranial complications and negatively correlated with patients' post-traumatic survival. Data indicate lesion-specific sequential involvement of GPR17 in the (a) death of irreversibly damaged neurons, (b) activation of microglia/macrophages remodeling the lesion, and (c) activation/proliferation of multipotent parenchymal progenitors (both reactive astrocytes and OPCs) starting repair processes. Data validate GPR17 as a target for neurorepair and are particularly relevant to setting up new therapies for TBI patients.
Industrial accidents with compressed air entering the gastro-intestinal tract often run fatally. The pressures usually over-exceed those used by medical applications such as colonoscopy and lead to vast injuries of the intestines with high mortality. The case described in this report is of a 26-year-old man who was harmed by compressed air that entered through the anus. He survived because of fast emergency operation. This case underlines necessity of explicit instruction considering hazards handling compressed air devices to maintain safety at work. Further, our observations support the hypothesis that the mucosa is the most elastic layer of the intestine wall.
Chronic exposure to heroin is known to cause cognitive deficits. However, little is known about the underlying molecular mechanisms. It has been suggested that opiate-induced neurotoxicity as well as impaired plasticity and regeneration may be relevant. One of the target regions where regeneration still can be observed in the adult brain is the hippocampus. Since polysialic acid neural cell adhesion molecule is regarded as one of the key players involved in plasticity and regeneration of neural tissue, we analyzed polysialic acid neural cell adhesion molecule expression in the fascia dentate hilus of the human hippocampus of 29 lethally intoxicated heroin addicts and matched controls. Immunohistochemistry with an antibody directed against polysialic acid neural cell adhesion molecule revealed its expression in differently sized cells which could be identified as neurons and glial cells. We observed an increase in the percentage of polysialic acid neural cell adhesion molecule positive neurons in hippocampal hilus of heroin addicts compared with controls (P=0.001).Interestingly, we also observed polysialic acid neural cell adhesion molecule expression in glial cells as evidenced by double immunofluorescence with glial fibrillary acidic protein and polysialic acid neural cell adhesion molecule using confocal laser scanning microscopy. The fraction of polysialic acid neural cell adhesion molecule positive glial cells was also higher in heroin addicts compared with controls (P=0.009). In addition, within the group of addicts morphine blood concentrations showed a positive correlation with the percentage of polysialic acid neural cell adhesion molecule positive neurons (P=0.04; r=0.547). In conclusion, we observed an increase in polysialic acid neural cell adhesion molecule positive neurons and glial cells in hippocampi of heroin addicts. This might reflect an attempt to repair cell damage due to heroin exposure.
Current responses to N-methyl-D-aspartate (NMDA) in layer V pyramidal neurons of the rat prefrontal cortex were potentiated by the P2 receptor agonists adenosine 5'-triphosphate (ATP) and uridine 5'-triphosphate (UTP). The failure of these nucleotides to induce inward current on fast local superfusion suggested the activation of P2Y rather than P2X receptors. The potentiation by ATP persisted in a Ca(2+)-free superfusion medium but was abolished by 1,2-bis(2-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis(acetoxymethyl) ester, cyclopiazonic acid, 7-nitroindazole, fluoroacetic acid, bafilomycin, and tetanus toxin, indicating that an astrocytic signaling molecule may participate. Because the metabotropic glutamate receptor (mGluR) agonists (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD) (group I/II) and (RS)-3,5-dihydroxyphenylglycine (group I) both imitated the effect of ATP and the group I mGluR antagonist 1-aminoindan-1,5-dicarboxylic acid or a combination of selective mGluR(1) (7-(hydroxyimino)-cyclopropa[b]chromen-1a-carboxylate) and mGluR(5) (2-methyl-6-(phenylethynyl)pyridine) antagonists abolished the facilitation by ATP, it was concluded that the signaling molecule may be glutamate. Pharmacological tools known to interfere with the transduction cascade of type I mGluRs (guanosine 5'-O-(3-thiodiphosphate), U-73122, xestospongin C, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, calmodulin kinase II [CAMKII] inhibitor peptide) depressed the actions of both ATP and ACPD. Characterization of the P2Y receptor by agonists (ATP and UTP), antagonists (suramin and pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid), and knockout mice (P2Y(2)(-/-)) suggested that the nucleotides act at the P2Y(4) subtype. In conclusion, we propose that exogenous and probably also endogenous ATP release vesicular glutamate from astrocytes by P2Y(4) receptor activation. This glutamate then stimulates type I mGluRs of layer V pyramidal neurons and via the G(q)/phospholipase C/inositol 1,4,5-trisphosphate/Ca(2+)/CAMKII transduction pathway facilitates NMDA receptor currents.
Astroglial cells in the central nervous system (CNS) are able to change their morphology and shape after different kinds of stimuli. We have developed a method for the structural description of astrocytes based on their representation as undirected simple graphs. The underlying image processing chain and the algorithm for the graph construction are presented and the graph parameters for the quantitative structural description of the astrocytes are discussed.
To determine how long pathological findings persist after burial and which factors play a role in decomposition of a corpse, we evaluated all bodies exhumed under the auspices of the Institute of Legal Medicine at the Hannover Medical School between 1978 and 1997. A total of 87 exhumations (54 men, 33 women) were performed in this period. The time bodies remained buried varied between 5 days and 16.8 years (mean 1.5 years, median 2.3 months). Fifty-six percent of the bodies were exhumed after at most 3 months, 10% remained buried for greater than 3 years. Pathomorphological changes of the soft tissues and the internal organs remained evident after several months, in some cases after several years of burial. Overall, it was possible to evaluate internal organs after 5 years of burial. Bodies became mostly decomposed after approximately 8 years at the earliest, although it was still possible to evaluate some soft tissue remnants after 16.8 years. In stepwise logistic regression, both the length of time the body was buried (p < 0.00005) and the time of year (p < 0.0019) clearly affected the rate of physical change. The variables of sex (p = 0.33), age (p = 0.61) and changes in the integrity of the body before burial (trauma, autopsy before burial; p = 0.15) did not influence the physical state of the body after exhumation. Our data show that much information may be gained from an exhumation even after significant time has passed since burial.
A worker was killed operating on a natural gas pipeline. At a receiver station the man intended to pick up two so called cleaning pigs, each weighing about 150 kg, diameter 0.5 m. For this purpose the gas pressure in the pig trap was let off by a valve, manometer controlled. According to an eyewitness's statement, the receiver pressure was equal to outside air pressure before the accident. The victim stood right in front of the flap of the receiver when he began to unfix the screws of the flap. Whilst working, the flap snapped out driven by the two cleaning pigs. The man and the devices were flung through a wire-netting fence and dropped down on a nearby field at a distance of 27, 29 and 38 m, respectively, from the receiver. The man died on the scene of the accident. The forensic autopsy ordered by the prosecution revealed signs of massive blunt trauma on the head, thorax and abdomen. In the criminological and forensic reconstruction of the accident the external injuries of the victim were found to be consistent with the front surface of the cleaning pig flung out first. It was determined that the second pig had got stuck in the receiver and that gas pressure had built up behind the pigs due to a leaky valve. As a consequence the pigs were expelled at a velocity of approximately 220 km/h causing a pattern of injury comparable to that of a fall from a great height.
Astrocytes in the hippocampus express glutamate receptors of the AMPA subtype. An increasing body of evidence suggests a contribution of astroglial AMPA receptors to a direct signaling between neurons and glial cells in vivo. Here, we have combined functional analysis with singlecell RT-PCR to investigate whether hippocampal astrocytes express Ca2+-permeable AMPA receptors. We show that by postnatal day 5, a mosaic of Ca2+-permeable and less Ca2+-permeable AMPA receptors coexists in individual astrocytes, while receptors with a more uniform, low divalent permeability dominate in older cells. Moreover, we report an upregulation of the flip form of the GluR2 subunit during maturation, while the splicing status of GluR1 and GluR4 remains unchanged. Due to its specific properties, Ca2+-permeable AMPA receptors in astrocytes might strengthen neuron-to-glia signaling and enable proper formation of structural and functional connections between glial cells and glutamatergic synapses in the developing hippocampus.
Membrane currents and changes in the intracellular Ca2+ concentration ([Ca2+](i)) were measured in HEK293 cells transfected with the human P2X(3) receptor (HEK293-hP2X(3)). RT-PCR and immunocytochemistry indicated the additional presence of endogenous P2Y(1) and to some extent P2Y(4) receptors. P2 receptor agonists induced inward currents in HEK293-hP2X(3) cells with the rank order of potency alpha,beta-meATP approximate to ATP > ADP-beta-S > UTP. A comparable rise in [Ca2+](i) was observed after the slow superfusion of ATP, ADP-beta-S and UTP; alpha,beta-meATP was ineffective. These data, in conjunction with results obtained by using the P2 receptor antagonists TNP-ATP, PPADS and MRS2179 indicate that the current response to alpha,beta-meATP is due to P2X(3) receptor activation, while the ATP-induced rise in [Ca2+](i) is evoked by P2Y(1) and P2Y(4) receptor activation. TCE depressed the alpha,beta-meATP current in a manner compatible with a non-competitive antagonism. The ATP-induced increase of [Ca2+](i) was much less sensitive to the inhibitory effect of TCE than the current response to alpha,beta-meATP. The present study indicates that in HEK293-hP2X(3) cells, TCE, but not ethanol, potently inhibits ligand-gated P2X(3) receptors and, in addition, moderately interferes with G protein-coupled P2Y(1) and P2Y(4) receptors. Such an effect may be relevant for the interruption of pain transmission in dorsal root ganglion neurons following ingestion of chloral hydrate or trichloroethylene.
6‐Hydroxykynurenic acid (6‐HKA), a derivative of kynurenic acid (KYNA) extracted from Ginkgo biloba leaves, was tested for its putative glutamate receptor (GluR) antagonism in comparison to the scaffold substance. The patch‐clamp method together with fast‐application techniques were used to estimate inhibition by 6‐HKA and KYNA of agonist binding at NMDA and α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) receptors (NMDARs and AMPARs) of CA1 pyramidal neurones. 6‐Hydroxykynurenic acid proved to be a low‐affinity antagonist. When comparing with KYNA, 6‐HKA was less potent at NMDARs (IC 50 = 136 versus 59 µ m ), but showed a higher affinity to AMPARs ( K B = 22 versus 172 µ m ). The replacement of 6‐HKA and KYNA by glutamate was investigated on outside‐out patches. Both antagonists competitively inhibited AMPAR responses and displayed fast unbinding kinetics, but the derivative was significantly slower displaced than KYNA (τ = 1.63 versus 1.22 ms). Our findings demonstrate that 6‐hydroxylation considerably changes the pharmacological profile of KYNA. Among the 6‐derivatives of KYNA, 6‐HKA shows the highest affinity to AMPARs. Despite its relatively low lipophily, these properties might be of clinical relevance under conditions that compromise the integrity of the blood–brain barrier. Furthermore, 6‐HKA should be a useful tool to analyse glutamate‐mediated synaptic responses.
The subunit composition of native AMPA receptor (AMPA-R) channels was recently described in several neuronal cell types but less information is available on glial cells. Evidence from recombinant receptor studies suggests that the expression of distinct subunits determines the specific functional properties of the receptor channel. In the present study, we combined the patch clamp technique with the reverse transcription-polymerase chain reaction (RT-PCR) to correlate the expression of gene transcripts with functional properties of AMPA-R in single identified glial cells of the hippocampus. The cells were freshly isolated from the stratum radiatum of the CA1 subregion. We focused on cells expressing AMPA-R with an intermediate Ca2+ permeability which were identified as immature astrocytes due to their morphological, immunocytochemical and electrophysiological characteristics. After recording, the cells were harvested and RT-PCR was performed with the same individual cell to investigate the composition of their AMPA-R transcripts. Our results suggest the expression of a heteromeric subunit architecture. In all cells, the GluR2 subunit was present, which is known to confer a low Ca2+ permeability to the receptor complex. Most frequently, we met co-expression of GluR2 and GluR4. This study demonstrates that astrocytes in the hippocampus express a distinct AMPA-R subunit composition which differs from neurons. The glial receptors might be involved in the modulation of gene expression as well as the regulation of proliferation and differentiation.
In the present study, we were interested in a quantitative analysis of voltage-activated channels in a subpopulation of hippocampal glial cells, termed “complex” cells. The patch-clamp technique in the whole-cell mode was applied to identified cells in situ and to glial cells acutely isolated from tissue slices. The outward current was composed of two components: a sustained and a transient current. The transient K+ channel had electrophysiological and pharmacological properties resembling those of the channel through which the A-currents pass. In addition, this glial A-type current possessed a significant Ca2+ dependence. The current parameters determined in situ or in isolated cells corresponded well. Due to space clamp problems in situ, properties of voltage-dependent Na+ currents were only analysed in suspended glial cells. The tetrodotoxin (TTX) sensitivity and the stationary and kinetic characteristics of this current were similar to corresponding properties of hippocampal neurons. These quantitative data demonstrate that at an early postnatal stage of central nervous system maturation, glial cells in situ express a complex pattern of voltage-gated ion channels. The results are compared to findings in other preparations and the possible consequences of transmitter-mediated channel modulation in glial cells are discussed.