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Biomedical subjects

J Schuberth

Publications and source records attributed to J Schuberth.

At least 19 recordsLinked to original sources
PubMed2000

In vitro cultivation of Trypanoplasma borreli (protozoa: kinetoplastida), a parasite from the blood of common carp Cyprinus carpio.

An in vitro culture system was developed for Trypanoplasma borreli, a pathogenic flagellate from the blood of European cyprinids. Trypanoplasms multiplied rapidly in a mixture of Hanks' balanced salt solution (HBSS, 45%), L15 (22.5%), Earle's minimum essential medium (MEM, 22.5%) and 10% distilled water, which was supplemented with 5 to 10% heat-inactivated pooled carp serum. In medium supplemented with fetal bovine serum, multiplication of T. borreli seemed to be inhibited. Cultures initiated with less than 100 000 T. borreli per ml culture medium did not survive, and a substantial multiplication of trypanoplasms was found at inocula beginning with 630 000 flagellates ml(-1). Trypanoplasms multiplied at 15, 20 and 25 degrees C. In cultures incubated at 4 degrees C the trypanoplasms remained viable but the number of flagellates did not increase. Trypanoplasms from in vitro cultures retained their infectivity for carp for at least 90 d (5 passages). The trypanoplasms survived in culture over a period of up to 5 mo (10 passages). The established culture system allows the propagation of high numbers of fish-infective trypanoplasms, which are required to study parasite-host relationships in carp.

Animals↗
PubMed1997

Gas residues of engine starting fluid in postmortem sample from an arsonist.

Diethyl ether was found in samples of the blood, urine, and lung from a fire victim. Because the lung also carried a number of low-boiling paraffins, it was inferred that the detected compounds came from engine starting fluid, which the victim apparently had been exposed to while be intentionally used it as an accelerant to start the fire. The reported death illustrates the value of searching post mortem samples for highly volatile residues of possible arson accelerants.

Adult↗
PubMed1996

A full evaporation headspace technique with capillary GC and ITD: a means for quantitating volatile organic compounds in biological samples.

The full evaporation technique (FET), which is a variant of headspace analysis used to overcome matrix effects, was combined with capillary gas chromatography (GC) and ion-trap detection (ITD). The aim was to enable quantitative tests of volatile organic compounds (VOCs) in blood and postmortem tissue samples. FET was applied to sample sized less than 35 mg whose VOCs were released from the matrix at an equilibration temperature of 130 degrees C. A capillary column with a nonpolar stationary phase was used for GC, and ITD was performed with the mass spectrometer run in full-scan mode. The potential of FET-GC-ITD was studied for the analysis of blood samples spiked with low concentrations of ethanol, acetone, 2-propanol, and 2-butanone and on brain tissue that contained methyl tert-butyl ether (MTBE), Benzene, toluene, ethylbenzene, o-, m-, and p-xylene, and propylbenzene. Samples were obtained from the bodies of victims who had inhaled smoke during an arson or accidental fire. There was a linear relationship between peak area and sample size, which indicates that the conditions of full evaporation were met and that the matrix effect was negated. The total analyte amount in the test sample at the limit of quantitation was in the range of 0.4-1 nmol for polar VOCs in blood and 0.03-0.1 nmol for nonpolar VOCs in brain tissue. Data on precision and accuracy of the method are reported.

Alcohols↗
PubMed1994

Post-mortem test for low-boiling arson residues of gasoline by gas chromatography-ion-trap mass spectrometry.

Using headspace capillary GC-MS with ion-trap detection, the additive in motor gasoline, MTBE (methyl tert.-butyl ether), was spotted in the blood from five victims of arsons set off with motor gasoline. In the brain from a death of a fire started by ignited isoparaffins, a number of branched C8 alkanes were found. Since 80 control samples of accidental fires, started by non-chemical means, tested negative for MTBE or isoparaffins, the data suggested that post-mortem exams for low-boiling organics may offer a new concept for arson analysis.

Ethers↗
PubMed1991

Volatile compounds detected in blood of drunk drivers by headspace/capillary gas chromatography/ion trap mass spectrometry.

As shown by others, ethanol and methanol appear in the breath of normals, and endogenous methanol becomes detectable also in the blood after intake of ethanol. In this study I have investigated whether low-molecular-weight volatile organics, other than methanol, arise in the blood of drunk drivers who had imbibed alcoholic beverages. To this end a method for searching for such compounds in the blood is described. It was based on headspace extraction, gas chromatographic separation on a DB-WAX capillary, and ion trap detection in the mass range 29-99 u. Detection limits, as defined by the analyte concentration that gives a signal equal to three times the standard deviation of the baseline noise, were estimated for the different mass numbers used in the substance search. Given the detection limits, presented as mmoles per litre (numbers within parentheses), in every drunk driver's blood with more than 10 mmol l-1 of ethanol between seven and nine different volatile substances were spotted. These were ethanol (0.15), 2-propanone (0.015), ethyl acetate (0.0005), 2-butanone (0.006), methanol (1.5), 2-propanol (0.06), ethanol (0.7), 2-butanol (0.03), and 1-propanol (0.03).

1-Propanol↗
PubMed1989

Computer-aided headspace gas chromatography applied to blood-alcohol analysis: importance of online process control.

This paper describes the analysis of ethanol in blood specimens from suspect drunk drivers and the associated quality assurance procedures currently used in Sweden for legal purposes. Aliquots of whole blood from two separate Vacutainer tubes are diluted with 1-propanol as internal standard before analysis by headspace gas chromatography (HS-GC) with three different stationary phases: Carbopak B, Carbopak C, and 15% Carbowax 20 M. The actual HS-GC analysis, the integration of chromatographic peaks, the collection and processing of results, as well as the quality control tests involve the use of computer-aided techniques. The standard deviation of analysis(y) increased with concentration of ethanol in the blood specimen(x), and above 0.50 mg/g the regression equation was y = 0.0033 + 0.0153x. The prosecution blood-alcohol concentration (BAC) is the mean of three separate determinations made by different laboratory technicians working independently with different sets of equipment. A deduction is made from the mean analytical result to compensate for random and systematic errors inherent in the method. At BACs of 0.5 and 1.5 mg/g, which are the statutory limits in Sweden, the allowances currently made are 0.06 and 0.09 mg/g, respectively. Accordingly, the reduced prosecution BAC is less than the actual BAC with a statistical confidence of 99.9%.

Alcoholic Intoxication↗
PubMed1985

Drugs in motorists traveling Swedish roads: on-the-road-detection of intoxicated drivers and screening for drugs in these offenders.

This paper deals with the police officer's or police doctor's ability to find drivers under the influence of drugs. We have also studied whether the protocol on the driver's previous histories of drug intake is useful for directing the chemist in his analytical approach to revealing intoxicants in the suspects' body fluids. A comprehensive procedure for screening traffic-hazardous drugs in the urine was found necessary and is described. By using this method, we have studied the incidence of drunken drivers with detectable medicinal or illicit agents. The results demonstrate that 91% of those drivers found by the officer or doctor of the police to be on intoxicants other than ethanol, carried some kind of traffic-hazardous drug in their body fluids, and that the doctor was a better judge than the police in identifying these offenders. By using a series of chemical methods for drug screening, we found that every third driver suspected of drunken driving due to ethanol, but not to other intoxicants, held some kind of a traffic-hazardous drug substance in his urine; benzodiazepines and cannabinoids were the most common findings. The data imply that 34% of these suspects revealed their intakes of traffic-dangerous intoxicants. We conclude that the judgements of both the officer and doctor of the police are needed for an efficacious detection of drivers under the influence of drugs. Moreover, the results infer that the chemist has to screen for intoxicants to reveal these in a suspect driver. We also conclude that drugs, particularly the benzodiazepines or cannabinoids, may be commonly encountered in drunken drivers, suspected of being inebriated by ethanol but no other toxicants.

Alcoholic Intoxication↗
PubMed1975

Transport of choline from plasma to cerebrospinal fluid in the rabbit with reference to the origin of choline and to acetylcholine metabolism in brain.

The supply of choline to the brain and the interrelationship between acetylcholine metabolism in the brain, choline in cerebrospinal fluid (CSF) and choline in plasma has been investigated by studying the transport of deuterium labelled choline from plasma toCSF in rabbits. The experiments were performed either by i.v. infusion of labelled choline or by administering deuterium choline in the diet until steady state levels were reached. All assays of labelled as well as unlabelled choline and acetylcholine were carried out by gas chromatographic-mass spectrometric technique. From these experiments it was found that the half-lives of the disappearance of labelled choline in plasma and CSF were similar (15 min) and the mole fraction of labelled choline in plasma was approximately 2.4 times that in CSF. The half-life of labelled acetylcholine in brain was about 25 min. In the time interval 10-20 min, the mole fraction of brain acetylcholine was the same as that of CSF choline. When infusion was carried out during pentobarbital anaesthesia the mole fraction of labelled brain acetylcholine decreased and that of labelled CSF choline increased compared to those of conscious animals. At steady state the mole fraction of labelled choline in plasma was nearly twice as high as that in CSF which in turn was significantly higher than that of acetylcholine in the brain. From these results it is suggested that in rabbit, free and derived choline in plasma are supplied to the brain in equal amounts. Furthermore it is suggested that choline is transported from plasma, via the extracellular space of the brain to CSF. In the extracellular space a part of choline is diverted and exchanged with choline in the acetycholine metabolic pathway.

Acetylcholine↗