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H Wittig

Publications and source records attributed to H Wittig.

17 recordsLinked to original sources
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↗
PubMed1984

[Quantitative determination of toxic elements in microbiologically produced technical protein feeds. 3. Photometric determination of trace amounts of arsenic using silver diethyldithiocarbamate and the atomic absorption spectrometry-hydride technic].

With a view to the determination of trace amounts of arsenic in microbiologically produced protein feeds, the authors compared the results yielded by the photometric method using silver diethyl dithiocarbamate ( AgDDTC ) with those obtained by means of the atomic absorption spectrometry(AAS)-hydride technique. Prior to analysis, the samples were dry-ashed after addition of Mg/Mg(NO3)2 or digested with nitric acid. Further comparative results were obtained by neutron-activation analysis. These methods were used to analyze novel protein feeds produced from yeast and bacterial biomasses, as well as some fermentation raw materials, for arsenic. A comparison of the values found with literature data relative to the arsenic contents of conventional protein feeds and foods shows that the novel microbiologically produced protein feeds are absolutely able to compete with protein feeds and foods currently used.

Animal Feed↗
PubMedDate not supplied

Stiff-man syndrome: possible autoimmune etiology targeted against GABA-ergic cells.

We report the case of a female patient, who died at the age of 66 years. Besides an insulin-dependent diabetes mellitus (IDDM) she had developed the clinical symptoms of stiff-man-syndrome (SMS) and harbored autoantibodies against glutamate-decarboxylase (GAD) in blood and liquor. GAD catalyzes the biosynthesis of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). The autopsy revealed typical alterations observed in diabetes mellitus including an incomplete fibrosis of pancreatic Langerhans islets. A decrease of GABA-ergic cells in the cerebellar cortex was observed, and a size reduction of Renshaw cells in the spinal cord. Furthermore, a dilution series of a polyclonal GABA antibody delivered a reduced immunofluorescence in the cerebellum. In skeletal muscle a neurogenic atrophy was observed. As described in literature, the clinical symptoms decayed following clonazepam administration. We suggest that this case including GAD autoantibodies, dramatic loss of GAD-expressing pancreatic cells, and loss or atrophy of GABA secretory neurons, supports the hypothesis that SMS may be an autoimmune disease directed against GABA-ergic cells. Furthermore, we suggest a neuronal hypersensitivity at the spinal cord level caused by the atrophic Renshaw cells.

Aged↗