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H Köhler

Publications and source records attributed to H Köhler.

At least 19 recordsLinked to original sources
PubMed2006

Comparative macrorestriction and RFLP analysis of Mycobacterium avium subsp. avium and Mycobacterium avium subsp. hominissuis isolates from man, pig, and cattle.

In Germany, tuberculous lesions in slaughtered pigs due to infection with members of the Mycobacterium avium complex are increasingly reported. Contaminated food originating from pig or other livestock is discussed as potential source of human infection. M. avium isolates from man (n=45), pig (n=29), and cattle (n=13) were characterised by restriction fragment length polymorphism (RFLP) with respect to insertion sequences IS1245 and IS901 as well as by XbaI-based pulsed-field gel electrophoresis (PFGE) and the results were compared by computer cluster correlation analysis, to determine potential sources of infection in man. By PCR, 55% of animal isolates was identified as M. avium subsp. avium, and 45% as M. a. hominissuis. All human isolates belonged to M. a. hominissuis. IS1245-RFLP and PFGE resulted in two distinct main groupings reflecting the two subspecies, and dividing the isolates into several subgroups. Animal isolates of M. a. hominissuis were widely distributed within the subgroups of human isolates. M. a. avium isolates, further discriminated by IS901-RFLP, formed host-associated subgroups for animals. Comparison of RFLP patterns with those of PFGE resulted in different subgroups as well as different pairs of isolates with high similarities. Only two isolates exhibited identical patterns by both methods. In general, results of both methods support the possibility that M. a. hominissuis isolates from livestock represent a source of infection for man, probably by common environmental reservoirs. There was no evidence of human infections caused by M. a. avium in Germany.

Animals↗
PubMed2006

Quantitative determination of taxine B in body fluids by LC-MS-MS.

A new specific and sensitive LC-MS-MS method for the detection of taxine B and isotaxine B, the main toxic pseudo-alkaloids from yew (Taxus sp.), in biological samples (blood, urine, gastric content) was developed. Biological samples were prepared for LC-MS-MS by means of solid-phase extraction (SPE) procedure and yielded a recovery of 86%. Chromatographic separation was achieved using an RP(18) column. Detection of taxine B and isotaxine B was performed using multiple reaction monitoring with m/z 584.2 as precursor ion, i.e. [M+H](+), of both isomers and m/z 194.3 and m/z 107.1 as product ions after collision-induced dissociation. Docetaxel was applied as internal standard. The method was fully validated for the analysis of blood samples. Linearity was proven in the range from 0.1-500 ng/g. The limit of detection and the limit of quantitation are 0.4 and 2 ng/g, respectively. The method was applied to the determination of taxine B and isotaxine B in four fatal cases (two humans, two horses) with suspected yew intoxication. Blood levels were 105, 168, 174 and 212 ng/g.

Adult↗
PubMed2006

[Volume retention in heart failure, nephrotic syndrome, and liver cirrhosis].

Volume retention in heart failure, nephrotic syndrome, and liver cirrhosis reflects pathological changes in homeostatic mechanisms that regulate the extracellular volume (sympathetic activity, renin-angiotensin-aldosterone system [RAAS], natriuretic peptides) and plasma osmolality (antidiuretic hormone [ADH]). In heart failure and liver cirrhosis, these changes are induced by a reduction of the effective circulating volume, which is the part of the extracellular fluid that is within the arterial system and effectively perfusing the tissues. This reduction in the effective circulating volume is caused by reduced cardiac output (heart failure), or by splanchnic vasodilatation with arterial underfilling (liver cirrhosis). In both cases, baroreceptors in both the carotid sinuses and in the glomerular afferent arterioles upregulate RAAS- and sympathetic activity, resulting in systemic vasoconstriction and renal sodium (and volume) retention. More severe reductions in the effective circulating volume may additionally stimulate ADH release, thus increasing the reabsorption of free water with subsequent hyponatriemia. In nephrotic syndrome, volume retention results either directly from the primary renal disease, which induces renal sodium and volume retention ("overfilling"), or indirectly from the reduced plasma oncotic pressure due to hypoalbuminemia, which induces a fluid shift from the intravascular to the interstitial space ("underfilling") with subsequent acitivation of baroreceptors and secondary sodium and volume retention.

Blood Volume↗
PubMed2005

Sudden death after isobutane sniffing: a report of two forensic cases.

The intentional inhalation of a volatile substance ("sniffing") causing euphoria and hallucinations is an under-recognised form of substance abuse in children and adolescents with a high morbidity and mortality. Sudden death can be caused by cardiac arrhythmia, asphyxia or trauma. Two fatal cases of isobutane sniffing of cigarette lighter refill containing isobutane are reported. Toxicological investigations revealed the presence of isobutane in the heart blood and brain tissue of both cases (case 1: heart blood 0.1 microg/g, brain tissue 2.3 microg/g; case 2: heart blood 4.6 microg/g, brain tissue 17.4 microg/g) and the presence of its metabolite 2-methyl-2-propanol in the heart blood of both cases (0.5 and 1.8 microg/g, respectively). The histological investigations of the inner organs showed similar results in both victims. Autopsy findings, results of the histological and immunohistochemical investigations, toxicological findings and analytical procedures are discussed.

Administration, Inhalation↗
PubMed2005

HPLC with laser-induced native fluorescence detection for morphine and morphine glucuronides from blood after immunoaffinity extraction.

A new immunoaffinity solid phase extraction of morphine and its phase II metabolites, morphine-3-beta-D-glucuronide and morphine-6-beta-D-glucuronide is described. An immunoadsorber was applied which was created for the first time by the immobilisation of specific antibodies (polyclonal, host: rabbit) by the sol-gel method. The extraction method in combination with high performance liquid chromatography-fluorescence determination has been validated and shown to be applicable to blood samples of heroin victims in a low concentration range. Blood extracts were essentially free of interfering matrix components when compared to C8-extracts. Additionally, a novel, sensitive and selective detection system for wavelength-resolved analysis of laser-induced fluorescence coupled to HPLC was developed. The analytes were excited with a frequency tripled Ti:Sa laser (lambda=244 nm quasi cw). The total emission spectrum was recorded with a detection system consisting of an imaging spectrograph and a back-illuminated CCD camera. This technique of detection, combined with an extended optical path (at least 6 mm could be illuminated by the laser), resulted in an optimal fluorescence intensity of the analytes. The method permitted the analysis of morphine, morphine-3-beta-D-glucuronide and morphine-6-beta-D-glucuronide in a low concentration range and could be applied to a complex matrix such as postmortem blood samples because analyte peaks could be discriminated from matrix peaks by their characteristic emission spectra.

Chromatography, High Pressure Liquid↗
PubMed2004

Suffocation and poisoning--the hard-hitting side of Munchausen syndrome by proxy.

Munchausen syndrome by proxy (MSBP) is a severe and difficult to diagnose form of child abuse characterised by the simulation, aggravation or production of symptoms of illness in a child by an adult. MSBP often leads to multiple hospitalisations and has a high mortality and long-term morbidity. This study describes the cases of 5 families with 8 children affected who presented with unexplained neurological or gastrointestinal symptoms or even loss of consciousness. All were victims of poisoning or suffocation by their mothers. Two of those children died and were initially diagnosed as SIDS or natural death, respectively. They were only recognised as MSBP victims after another sibling had fallen ill with similar symptoms. The cases are discussed in consideration of the relevant literature. In addition warning signs of this forensically relevant syndrome and a strategy for the management of suspected MSBP cases are described.

Asphyxia↗
PubMed2004

Development of a psilocin immunoassay for serum and blood samples.

After the immunisation of rabbits with a psilocin-specific immunogen, polyclonal antisera were obtained. With these antisera a competitive, heterogeneous radioimmunoassay for the detection of psilocin was developed. As tracer a derivative of psilocin was synthesised, which contained a tritiated CH(3) group. The antisera showed a specific reaction with psilocin. The cross-reactivity of structurally related endogenous substances like serotonin, tryptophan and tyrosine was below 0.01%. Also common drugs of abuse (Delta(9)-tetrahydrocannabinol, cocaine, morphine, amphetamine) showed negligible cross-reactivity (0.01-2%). Only tricyclic neuroleptics with a (dimethylamino)ethyl side-chain showed some cross-reactivity (20%). Spiked serum and blood samples were analysed with this new immunoassay and the results obtained were compared with the values measured with a validated GC-MS method.

Animals↗
PubMed2004

[Differential diagnosis of urinary findings].

Classical urinalysis is extremely useful in the differential diagnosis of diseases of the kidneys and lower urinary tract. Although dipsticks are suitable for orientational purposes, when pathology is indicated, and when renal disease presents, they must be supplemented by urine microscopy or quantitative and qualitative protein electrophoresis to establish the diagnosis. Phase-contrast microscopy can distinguish glomerular from nonglomerular hematuria and thus guide the further diagnosis, and the detection of leukocytes and bacteria confirms the diagnosis of urinary tract infection. In asymptomatic patients microhematuria or proteinuria is detected more frequently with increasing age. A differentiated diagnostic strategy must be adapted to the individual risk of the patient, and must avoid overdiagnosis while not missing potentially serious pathology.

Acanthocytes↗
PubMed2004

[Zoonoses in working- and wild animals and their significance in Germany. An overview].

The control of infectious diseases transmitted from animals to humans (zoonoses) was recently put on a new basis in the European Union when a new Zoonoses Directive entered into force. Brucellosis, campylobacteriosis, echinococcosis, listeriosis, salmonellosis, trichinosis, and the respective causative agents, tuberculosis due to Mycobacterium bovis, and verotoxigenic Escherichia coli must be included in monitoring. Additional zoonoses and zoonotic agents are to be monitored according to the epidemiological situation. Against this background, the current knowledge on important zoonoses transmitted from livestock and some wildlife animals to humans as well as the epidemiological situation in Germany with regard to these diseases is summarized.

Animals↗
PubMed2004

Determination of aconitine in body fluids by LC-MS-MS.

A very sensitive and specific method was developed for the determination of aconitine, the main toxic alkaloid from plants of the genus Aconitum L., in biological samples. The method comprised solid-phase extraction using mixed-mode Cs cation exchange columns followed by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Chromatographic separation was achieved with a RP8 column. Detection of aconitine was achieved using electrospray in the positive ionisation mode and quantification was performed using multiple reaction monitoring with m/z 646.4 as precursor ion, i.e. [M+H]+ of aconitine and m/z 586.5, m/z 526.4 and m/z 368.4 as product ions after collision-induced dissociation. The method was fully validated for the analysis of blood samples: the limit of detection and the limit of quantitation were 0.1 ng/g and 0.5 ng/g, respectively. Within the linear calibration range of 0.5-25 ng/g, analytical recovery was 79.9%. In two fatal cases with suspected aconite intoxication, aconitine could be detected in blood samples at concentrations of 10.0 and 12.1 ng/g. In one case, aconitine could also be detected in the stomach content (3 ng/g) and in the other in the urine (180 ng/ml).

Aconitine↗
PubMed2003

LC-MS determination of Taxus alkaloids in biological specimens.

A semi-quantitative LC-MS method was developed for the detection of the pseudo alkaloids of Taxus baccata (yew) from human body fluids and tissue samples. This method was used to examine the cause of death of a 43-year-old man who died several hours after he drank a decoction of taxus leaves. Autopsy and histology demonstrated early signs of myocardial hypoxia. Since investigation of the stomach content did not yield evidence of taxus ingestion, the taxus alkaloids were determined in blood, stomach content and tissue samples of the deceased by LC-MS. The samples were prepared by solid phase extraction on RP-18 columns. Chromatographic separation was achieved by HPLC on a RP-8 column, coupled to an ion trap mass spectrometer (Finnigan LCQ). An atmospheric pressure electrospray ionisation was performed. Spectra of the alkaloids were recorded in the single MS mode and in the MS-MS mode and compared with reference spectra obtained from an extract of yew leaves. In the stomach content, the kidneys, the liver and a heart blood sample of the deceased, alkaloids of Taxus baccata, predominantly taxine B and iso-taxine B, were identified. The semi-quantitative evaluation of the heart blood revealed a taxine concentration of 11 micro g taxine/g. As far as we know this is the first case in which a semi-quantitative analysis of taxine alkaloids has been performed.

Adult↗
PubMed2003

Influences of naturally occurring and experimentally induced porcine pneumonia on blood parameters.

It had been the objective of the studies described to establish local and systemic changes by naturally occurring pneumonia or pneumonia experimentally induced by Pasteurella multocida and Haemophilus parasuis in swine. Acute and chronic pneumonia was found to alter the cytokine level of lung lavage fluid and affect the composition and function of blood cells, especially with regard to phagocytosis, radical formation and cell surface receptors. Interleukin-6 levels in blood plasma rose 24h after experimental intrabronchial infection. The influences of the changes on growth and meat quality are discussed.

Acute Disease↗