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Biomedical subjects

G Rochholz

Publications and source records attributed to G Rochholz.

11 recordsLinked to original sources

Fatal intoxication with a decalcifying agent containing formic acid.

A fatality caused by ingestion of a decalcifying agent containing formic acid is reported. Quantitative analysis of formic acid in the form of its methyl ester was performed in different body fluids and organ samples using head-space gas chromatography with flame ionization detection. The blood taken at the time of admission to hospital had a concentration of 370.3 microg/ml, which declined to 13.9 microg/ml after 6.5 h of haemodialysis. Post-mortem concentrations were 855.4 microg/ml (heart blood), 2,712 microg/ml (gastric contents), 1128 microg/ml (haemorrhagic fluid from abdominal cavity), 3,051 microg/ml (bile), 2,664 microg/ml (contents of small intestine), 442.7 microg/g (liver) and 542.3 microg/g (kidney). The most important morphological findings for differentiating between oral and respiratory ingestion were ulceration of the oropharynx and the oesophagus as well as extensive necrotic lesions in the stomach and the duodenum without perforation. Death was caused by massive acidosis, haemolysis, bleeding complications, hepatic and renal failure. Toxicological and morphological findings revealed that a considerable amount of formic acid had been ingested orally with a suicidal intention.

Administration, Oral↗

Determination of paracetamol (acetaminophen) in different body fluids and organ samples after solid-phase extraction using HPLC and an immunological method.

A solid-phase extraction method routinely used for serum samples was improved and applied to the qualitative and quantitative determination of paracetamol in different body fluids, e.g. blood, urine, cerebrospinal fluid, synovial fluid, vitreous humor, and in tissue samples. A very simple method showed best results: Body fluids were mixed with phenacetine as internal standard and phosphate buffer (pH 6.8). Then protein was precipitated using acetonitrile. After strong centrifugation the supematant was transferred to a preconditioned Bakerbond C18-SPE-column. Elution with methanol without a prior washing step showed best recovery rates. The extracts were investigated using high-performance liquid chromatography with ultraviolet detection, a photometrical and an immunochemical method.

Acetaminophen↗

Quality assurance in age estimation based on aspartic acid racemisation.

Estimates of the age of living and dead individuals, obtained in order to answer legal or social questions, require minimum quality standards in order to guarantee data quality. We present an outline strategy (with recommendations) for the attainment of quality assurance in age estimation based on aspartic acid racemisation. The strategy is based on a definition of minimum standards for laboratories, including documentation of procedures, methodology and levels of expertise, and the formulation of guidelines for intralaboratory and interlaboratory quality control.

Age Determination by Teeth↗

[Value of "medication screening" in therapy for chronic pain].

INTRODUCTION: Drug therapy plays often an important role in the treatment of chronic pain. Former studies and also experiences of clinical practice have given evidence, that insufficient patient compliance is a widespread event. Therefore drug screening becomes a significant tool for quality assurance. In the following the methodical and practical aspects of drug screening are described and recommendations for its use in clinical practice are suggested. OBJECTIVE OF DRUG SCREENING: This tool can be used to check the intake of prescribed drugs, to detect hidden taken drugs, to decide whether side effects result of the prescribed medication or not and to support a withdrawal therapy. PRACTICAL BASICS AND INTERPRETATION OF THE FINDINGS: Drug screening presupposes an informed patient, who consents to the investigation. Otherwise confidence is risked and the handling with unexpected results is not possible any more. Testing of urine has the advantage of a non invasive procedure and makes use of the reservoir of the bladder. A close co-operation and good communication between therapist and laboratory prevents misinterpretations, which might result from inaccurate formulated questions or methodical limitations, for instance because of cross reacting substances or a too insensitive detection level for the respective drug. The finding must primary bee used to value the therapy and improve the compliance but can not prove the patient himself. CONCLUSIONS: Even if the value of drug screening is not prospectively investigated until now, clinical experiences reveals it is as powerful tool for monitoring effectiveness and side effects of pharmacotherapy of pain and also of patient compliance which the prescribed drug regimes.

English Abstract↗

Identification of osteocalcin as a permanent aging constituent of the bone matrix: basis for an accurate age at death determination.

Age at death determination based on aspartic acid racemization in dentin has been applied successfully in forensic odontology for several years now. An age-dependent accumulation of D-aspartic acid has also recently been demonstrated in bone osteocalcin, one of the most abundant noncollagenous proteins of the organic bone matrix. Evaluation of these initial data on in vivo racemization of aspartic acid in bone osteocalcin was taken a step further. After purification of osteocalcin from 53 skull bone specimens, the extent of aspartic acid racemization in this peptide was determined. The D-aspartic acid content of purified bone osteocalcin exhibited a very close relationship to age at death. This confirmed identification of bone osteocalcin as a permanent, 'aging' peptide of the organic bone matrix. Its D-aspartic acid content may be used as a measure of its age and hence that of the entire organism. The new biochemical approach to determination of age at death by analyzing bone is complex and demanding from a methodologic point of view, but appears to be superior in precision and reproducibility to most other methods applicable to bone.

Adult↗

Screening and identification of sumatriptan and its main metabolite by means of thin-layer chromatography, ultraviolet spectroscopy and gas chromatography/mass spectrometry.

Sumatriptan (CAS 103628-46-2, 3-[2-(dimethylamino)ethyl]-N-methyl-1H-indole-5-methanesulphonamide++ +), a substance for treatment of acute migraine attacks, and its main metabolite are investigated by thinlayer chromatography (TLC), ultraviolet spectroscopy, and gas chromatography/mass spectrometry (GC/MS). The resulting analytical data (correlated hRf-values, UV solvent spectra, remission spectra, GC retention indices, and electron impact (EI) mass spectra) including an extraction procedure and different derivatization methods are presented. Their applicability is described for urine analysis.

Biotransformation↗

Modified screening procedure with fluorescence detection for flunitrazepam and its metabolites via acridine derivatives.

A modified thin-layer chromatographic method with fluorescence detection is described for the screening of flunitrazepam and its major metabolites in urine. The method is based on the hydrolysis and subsequent formation of acridine derivatives by cyclization in dimethyl-formamide. This reliable screening procedure, which has proven its usefulness in many laboratories, provides valid results in the absence of diclofenac, carbamazepine, and tricyclic antidepressants. On the other hand these latter substances are frequently detectable in urine samples taken from addicts especially during therapy. So it was necessary to modify the procedure.

Acridines↗

[An improved screening program for 160 pesticides].

A screening system for 170 pesticides is reported. The following analytical methods are used: TLC (corrected Rf-value), GLC (retention index) and UV-spectroscopy. Also quantitative aspects are mentioned when modern TLC-scanners are applied.

Chromatography, Thin Layer↗