Biomedical subjects

H Wittig

Publications and source records attributed to H Wittig.

At least 19 recordsLinked to original sources

PubMed2004

Comparative regression analysis of concurrent elimination-phase blood and breath alcohol concentration measurements to determine hourly degradation rates.

Following the introduction of limit values for blood alcohol and breath alcohol concentrations of 0.5 g/kg and 0.25 mg/L, respectively, as provided under s. 24 a of the German Road Traffic Act the question is whether also breath alcohol concentrations can be back calculated to the time of the traffic offence in cases where it is definite that the person to be examined is in the period of alcohol elimination. To this end, a study was performed in which 56 healthy volunteers consumed 0.5, 0.8 and 1.0 g of ethanol mixed with fruit juice per kilogram of body weight over a period of 10-20 min. Calculations included all 391 pairs of concurrent blood alcohol and breath alcohol concentration values obtained after 2 h following the end of drinking. All volunteers exceeded the peak value of the alcohol curve. The measured values included were above 0.1 g/kg and 0.05 mg/L. For an average intake of alcohol of 0.88 g/kg the following regression lines were calculated for the period starting 2 h after the end of drinking: blood alcohol concentration [g/kg] = 1.318 - 0.172 h and breath alcohol concentration [mg/L] = 0.589 - 0.079 h. Subtracting the simple standard deviation from the mean value yielded hourly degradation rates above 0.1 g/kg and above 0.05 mg/L, respectively. Subtracting two standard deviations, the values fell below this level in both cases. In fact, back calculation of breath alcohol concentrations based on 0.05 mg/h seems to be possible for traffic offences if certain conditions are complied with, such as the use of Evidential 7110, a calibrated breath alcohol analyser approved by the Federal Physical-Technical Laboratory for measuring the breath alcohol concentration.

Adult↗

PubMed2003

LC-MS/MS analysis of pholedrine in a fatal intoxication case.

Pholedrine (4'-hydroxymethamphetamine) is a cardiovascular agent exerting hypertensive and adrenergic effects. High doses may cause a drop in the peripheral circulation blood flow and increase blood pressure, heart rate and body temperature up to a state of central respiratory paralysis. A 15-year-old girl who suffered from heavy agitation and hallucinations was admitted to the intensive care unit in a comatose state. The clinical findings included a maximum heart rate of 170 bpm and a body temperature of 43.8 degrees C. Resuscitation measures were in vain and abandoned after approximately 2h. A toxicological emergency analysis using GC/MS revealed a considerable amount of pholedrine in blood and urine. A method for determining pholedrine in human body fluids utilizing high-performance liquid chromatography (HPLC)/tandem mass spectrometry (LC-MS/MS) with a turbo ion-spray source was developed, using D11-methamphetamine and D5-methylenedioxymethamphetamine as internal standards. Samples were prepared by SPE extraction using SPEC-C18AR/MP3((R)) columns, which yielded the best extraction recovery (67%). Chromatographic separation was achieved at pH 5 on an RP-18 stationary phase applying gradient elution from 50 to 70% of B (methanol/acetonitrile 3/1 (v/v), 0.02% acetic acid) in A (5mM ammonium acetate/acetonitrile 95/5 (v/v), 0.02% acetic acid). Supra-pure acetic acid was added to the post-column effluent with a flow rate of 0.2 microl/min to optimize ionization. Detection was carried out in the positive ionization, multiple reaction monitoring (MRM) mode. The chromatograms showed no interference from other substances. The limit of detection (LOD, S/N=3) of pholedrine was 0.8 ng/ml and its lower limit of quantification (LLOQ, S/N=10) 3ng/ml. The calibration curve was linear (r=0.999) in the range 1-100 ng/ml. Samples with higher concentrations were diluted to suit the working range. The intra-day R.S.D. between 5 and 80 ng/ml were 3.8-8.7% and the inter-day R.S.D. between 5 and 100 ng/ml were 6.7-10.7%. The pholedrine concentrations in blood and urine collected when the girl was still alive were 16.1 microg/ml (R.S.D. 10.5%) and 1120 microg/ml (R.S.D. 8%), respectively. In post-mortem samples, they were 23.0 microg/ml (R.S.D. 5.1%) in heart blood and 27.3 microg/g (R.S.D. 6.6%) in the liver.

Adolescent↗

PubMed2003

Identification of the minor component of a mixed stain by using mismatch primer-induced restriction sites in amplified mtDNA.

We report a case in which STR typing failed to identify the minor component of a mixed saliva stain, but a mitochondrial restriction analysis succeeded in discriminating between the two components. To identify the nt16093 and nt16265 transitions, the template was amplified with the mismatch primers L16092-mm16085 and H16266-mm16269. In the presence of the transitions the mismatch primers created a BsaB I and a Cac8 I restriction site, respectively. Subsequently, aliquots were restricted separately using the enzymes Cac8 I and BsaB I which clearly identified the minor stain component.

Beverages↗

PubMed2000

Is it possible to differentiate mtDNA by means of HVIII in samples that cannot be distinguished by sequencing the HVI and HVII regions?

The mitochondrial control region includes three so-called hypervariable (HV) regions, in which the polymorphic positions show a particularly high frequency. According to a population study of 200 unrelated individuals from Germany, HVI (positions 16,024-16,365, according to Anderson) showed 88 variable positions in a total length of 342 bp (26%) and HVII (positions 73-340) displayed 65 mutable sites in 268 bp (24%). HVIII (positions 438-574) exhibited a slightly lower variability, with 25 polymorphic sites within 137 bp (18%), but contrasted clearly with the background, which showed variability rates of only 7% (positions 16,366-16,569, 1-72) and 3% (positions 341-437), respectively. At present, the displacement (D)-loop database in Magdeburg comprises 904 sequences of the mitochondrial HVI region and HVII region from Germans, Austrians and Swiss. By means of this material, the extent to which the mtDNA sequences that do not differ in the HVI and HVII regions can be differentiated by additionally sequencing HVIII was investigated.

Austria↗

PubMed2000

Mitochondrial DNA in the Central European population. Human identification with the help of the forensic mt-DNA D-loop-base database.

Sequencing of mtDNA is an advanced method for the individualisation of traces. Disadvantages of this method are expensive and time-consuming analysis and evaluation procedures as well as the necessary stock of population-genetic data which is still insufficient. Central European institutes of forensic medicine from Germany, Austria, and Switzerland have been working together since the beginning of 1998 to establish a mtDNA database. The aim is to build up a large stock of forensically established data and provide population-genetic data for frequency investigations, which will serve as a basis for expert opinions and scientific research. Good data quality is ensured by using original sequences only. Ring tests, which have been conducted to enhance analytical reliability, revealed a high correspondence rate of the analytical results obtained by the individual member institutes. Today 1410 sequences are available for comparison, of which 1285 sequences in the HV1 and HV2 regions cover the full ranges from 16051 to 16365 and from 73 to 340 (according to Anderson). The major part is formed by Central European sequences comprising 1256 data sets from Germany, Austria, and Switzerland. Today the database contains sequences from a total of 12 European, six African and three Asian countries including 100 sequences from Japan. This paper is aimed at discussing the individualisation potentials of mtDNA as well as the possibilities and limits of ethnic differentiation by means of pairwise sequence differences on the basis of the data stock available.

Austria↗

PubMed2000

Expression of the plasminogen activator system and the inhibitors PAI-1 and PAI-2 in posttraumatic lesions of the CNS and brain injuries following dramatic circulatory arrests: an immunohistochemical study.

Plasminogen activators as inducible extracellular serine proteases are involved in a variety of processes, such as the degradation of brain structures. In regions of brain degradation, an increase in the expression of genes encoding cytokines and proteinases has recently been demonstrated. We tested the hypothesis, whether the plasminogen activator system as well as the plasminogen activator inhibitors are expressed and possibly involved in a proteolytic cascade that breaks down the extracellular matrix as a result of ischemic or posttraumatic brain destructions. To study this supposition, we investigated immunohistochemically the expression of tPA, uPA and its receptor, the plasminogen activator inhibitors PAI-1 and PAI-2, tetranectin as well as the laminin breakdown as an event of secondary brain injury. Brain tissue from 21 autopsy cases with severe brain injuries, material from 14 ischemic infarcts and 11 controls with acute hypoxia were used. All components of the plasminogen activator system studied were over-expressed immunohistochemically in reactive astrocytes, microglia and endothelial cells around the lesion zone. Tetranectin showed an analogous distribution to the plasminogen activator system. A reduced immunoreactivity of laminin within the identical region of destruction was detected concomitant with laminin remnants in perivascular macrophages, so that a remarkable role of the plasmin cascade in the degradation of extracellular matrix proteins in the brain is taken into consideration.

Adult↗

PubMed1999

A systematic regional study of dopamine and dopamine-derived salsolinol and norsalsolinol levels in human brain areas.

Dopamine and the dopamine-derived tetrahydroisoquinoline alkaloids salsolinol and norsalsolinol were measured by high-performance liquid chromatography with electrochemical detection in 15 regions of the human brain. The regional distribution of dopamine in 32 brains was similar to previous reports with highest concentrations in the basal ganglia, especially in the striatum, followed by the substantia nigra and the hypothalamus. Significant amounts of salsolinol and norsalsolinol were only found in these dopamine-rich areas, whereas in the other regions no alkaloids were detected. These findings suggest that the concentration of the substrate dopamine may determine the alkaloid level during in vivo formation.

Adult↗

PubMed1999

Loss of heteroplasmy in the displacement loop of brain mitochondrial DNA in astrocytic tumors.

The aim of this study was the determination of D-loop heteroplasmy in astrocytic brain tumors. DNA fragments corresponding to the hypervariable region 2 of the mitochondrial displacement loop (D-loop) from 12 astrocytic tumors and 2 corresponding brain samples were cloned into a plasmid vector. Heteroduplex analysis revealed high sequence variability in the brain samples and a subfraction of grade 2 and grade 3 tumors. Furthermore, the results were suggestive of a very low degree of heteroplasmy in all glioblastomas. This was confirmed by direct sequencing of 223 cloned DNA samples from nine individuals. Heteroplasmy was caused in most cases by a well-known length polymorphism of a homopolymeric c-tract. Heteroplasmy of the two reference brain samples was lost in the corresponding tumors. Genes Chromosomes Cancer 26:80-83, 1999.

Adult↗

PubMed1998

Early magnetic resonance imaging of brainstem lesions after severe head injury.

OBJECT: The availability of magnetic resonance (MR) imaging data obtained in comatose patients after head injury is scarce, because MR imaging is somewhat cumbersome to perform in patients requiring ventilation and because, in the first hours after injury, its relevance is clearly inferior to computerized tomography (CT) scanning. The authors assessed the value of MR imaging in the early postinjury period. METHODS: In this prospective study MR imaging was performed in 61 consecutive patients within 7 days after they suffered a severe head injury. An initial CT scan had already been obtained. To understand the clinical significance of the lesions whose morphological appearance was identified with MR imaging, brainstem function was assessed by registration of somatosensory and auditory evoked potentials. Brainstem lesions were visualized in 39 patients (64%). Bilateral pontine lesions proved to be 100% fatal and nonbrainstem lesions carried a mortality rate of 9%. In singular cases circumstances allowed for a clear clinical distinction between primary and secondary brainstem lesions. On MR imaging all lesions were hyper- and hypointense after intervals longer than 2 days. Within shorter intervals (< 2 days) after the injury, primary lesions appeared isointense on MR imaging. In one secondary brainstem lesion there were no traces of blood. CONCLUSIONS: Because mean intracranial pressure (ICP) levels in patients without brainstem lesions were similar to those in patients with brainstem lesions, the authors conclude that it was not mainly increased ICP that accounted for the high mortality rates in patients with brainstem lesions. The authors also conclude that brainstem lesions are more frequently found in severe head injury than previously reported in studies based on neuropathological or CT scanning data. Early MR imaging after head injury has a higher predictive value than CT scanning.

Adult↗

PubMed1997

Hypothalamic osteolipoma: a case report.

The authors present a case of an ossified lipoma at tuber cinerum, an incidental finding when performing an autopsy of a 61-year old male. A tight connection to right communicans posterior artery led first to the diagnosis of a calcified saccular aneurysm, but histologic examination revealed an osteolipoma consisting of mature adipose tissue and formation of bone. Intracranial lipomas are neither hamartomas nor true neoplasms, but they are more likely to be congenital malformations. The recent literature is reviewed, and the two most current embryologic concepts of the development of intracranial lipomas are discussed.

Autopsy↗

PubMed1996