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Biomedical subjects

H J Kaatsch

Publications and source records attributed to H J Kaatsch.

At least 19 recordsLinked to original sources
PubMed2003

[Impairment of safety in navigation caused by alcohol: impact on visual function].

BACKGROUND: So far in Germany, no legally binding standards for blood alcohol concentration exist that prove an impairment of navigability. The aim of our interdisciplinary project was to obtain data in order to identify critical blood alcohol limits. In this context the visual system seems to be of decisive importance. MATERIALS AND METHODS: 21 professional skippers underwent realistic navigational demands soberly and alcoholized in a sea traffic simulator. The following parameters were considered: visual acuity, stereopsis, color vision, and accommodation. RESULTS: Under the influence of alcohol (average blood alcohol concentration: 1.08 per thousand ) each skipper considered himself to be completely capable of navigating. While simulations were running, all of the skippers made nautical mistakes or underestimated dangerous situations. Severe impairment in visual acuity or binocular function were not observed. Accommodation decreased by an average of 18% ( p=0.0001). In the test of color vision skippers made more mistakes ( p=0.017) and the time needed for this test was prolonged ( p=0.004). CONCLUSIONS: Changes in visual function as well as vegetative and psychological reactions could be the cause of mistakes and alcohol should therefore be regarded as a severe risk factor for security in sea navigation.

Accidents↗
PubMed2003

[Impairment of safety in navigation caused by alcohol: pupillography and measurement of pupil movements].

OBJECTIVE: To evaluate data in an interdisciplinary project (ophthalmology, forensic medicine, internal medicine, psychology,and nautical science) in order to identify critical blood alcohol limits in sea navigation. METHODS: A sea traffic simulator was employed for realistic nautical demands on 21 professional experienced skippers under sober and alcoholized conditions (target blood alcohol concentration: 1.0 per thousand ). After simulated navigation, pupil light reflex, spontaneous pupil movements,nystagmus,and saccades were evaluated by pupillography. Modification of the pupillograph enabled us also to measure optokinetic nystagmus. RESULTS: Evaluation of the pupil light reflex revealed obvious changes in the extent of relative contraction and in redilatation time under the influence of alcohol. Diminished vigilance could be observed in all of the skippers when optokinetic nystagmus was tested. CONCLUSION: The pupillograph represents a suitable device for measuring functions of the visual and vegetative systems. Thus, the impact of these functions on nautical capability can be demonstrated. If further investigations such as ophthalmological, medical, psychological, and nautical evaluations are taken into account, it could be determined that blood alcohol levels of 1.0 per thousand may exclude safe navigation.

Accidents↗
PubMed2001

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↗
PubMed2000

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↗
PubMed2000

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↗
PubMed2000

Age estimation: the state of the art in relation to the specific demands of forensic practise.

Age estimation in cadavers, human remains and living individuals may clarify issues with significant legal and social ramifications for individuals as well as for the community. In such cases methods for estimating age should fulfil the following specific demands: (1) they must have been presented to the scientific community, as a rule by publication in peer-reviewed journals, (2) clear information concerning accuracy of age estimation by the method should be available, (3) the methods need to be sufficiently accurate and (4) in cases of age estimation in living individuals principles of medical ethics and legal regulations have to be considered. We have identified and summarized the methods that essentially fulfil these specific demands. In childhood and adolescence morphological methods based on the radiological examination of dental and skeletal development are to be recommended. In adulthood, the accuracy of most morphological methods is much reduced. Here a biochemical method based on aspartic acid racemization in dentine provides the most accurate estimates of age, followed by special morphological dental and skeletal methods. The choice of method has to take account of the individual circumstances of each case. Most methods require either the consultation of specialised and trained scientists or an adequate calibration by the "user". Very few attempts have been made to find common standardisation, calibration and evaluation procedures or to develop means of quality assurance for methods of age estimation. Efforts in these directions are necessary to guarantee quality standards and adequate answers to the important legal and social issue of age estimation in forensic medicine.

Adolescent↗
PubMed2000

Fatal lipid embolism following intraarterial angiography at an early stage of arteriosclerosis.

Intraarterial angiography was performed on a patient with peripheral arterial occlusive disease (Fontaine IIb). No relevant risk factors were known, and a previous angiography had been undertaken without incident. After administration of contrast medium, the patient complained of acute pain in the lower abdomen and both legs, and a sudden rise in blood pressure was observed. The patient subsequently lost consciousness and died within 1.5 h. Postmortem examination showed that death was due to peripheral atheromatous microembolism of lipids, and not cholesterol as is usual in these cases. The differential diagnosis is discussed and a review of the literature is presented.

Angiography↗
PubMed1999

How and why does the platelet count in postmortem blood change during the early postmortem interval?

We examined the changes in the early postmortem platelet count in postmortem blood and the reasons for these changes by counting the platelets, by performing in vitro hypostatic tests, by estimating the percentage of erythrocytes by volume in postmortem blood samples, by immunohistochemistry (anti-CD61, anti-fibrinogen), and by immunoelectron microscopy (anti-CD62, anti-CD63, anti-thrombospondin). The apparent initial increase in the platelet count in postmortem blood was found to be caused by hypostatic phenomena. The subsequent discontinuous decrease in the platelet count despite continuing hypostasis in the corpse can be explained in part by postmortem thrombolysis and the development of reversible platelet-platelet aggregates. The main point is, that changes in the postmortem blood environment cause potentially reversible adhesion of platelets to pre-adsorbed fibrinogen on erythrocytes. Thus the decrease in the number of platelets in postmortem blood is not attributable to postmortem clotting but to a decrease in the number of countable platelets in postmortem blood.

Adult↗
PubMed1999

Improved DNA typing of human urine by adding EDTA.

The effect of different EDTA concentrations on the DNA content of urine samples was examined and compared to untreated urine at various storage temperatures and times. The results indicate that adding EDTA increases the DNA stability for long time storage especially at low temperatures.

DNA↗
PubMed1999

DNA typing in cases of blood chimerism.

A chimera is an organism whose cells derive from two or more distinct zygote lineages. and therefore two different blood cell populations circulate in one individual. To point out the potential pitfalls in forensic analysis, a set of triplets (a girl and two boys) who revealed blood chimerism was investigated with four STR systems using PCR. The results indicated that a DNA profile based on DNA extracted from blood can lead to a false determination because the band pattern of each triplet contained a mixture of the original genotype and the genotype of the siblings. Additional investigations on biological materials other than blood must be made in order to find out the real genetic characteristics of each child.

Adult↗
PubMed1996

[Visual evoked potentials in low blood alcohol concentrations].

BACKGROUND: Both the acute toxic effects of ethanol on the central nervous system and the effects of chronic alcohol consumption on the optic nerve (tobacco-alcohol amblyopia) are well known. We investigated the acute effect of low blood alcohol concentrations on visual evoked potentials. MATERIALS AND METHODS: A pattern VEP (stimulation by TV monitor, alternating chequerboard patterns, 45', 2 Hz, contrast 90%) was performed in ten healthy volunteers in sober condition and 0, 30, 60, 90 and 120 min following ingestion of 1 g/kg body weight ethanol (resulting in a blood alcohol concentration of 0.8-1.1%). Blood samples were drawn from the cubital vein simultaneously with each recording to determine blood alcohol concentration. RESULTS: Neither peak latencies nor amplitudes showed significant changes related to blood alcohol concentration. CONCLUSION: No acute impairment of the optic nerve caused by ingestion of low doses of alcohol could be found using pattern VEP.

Adult↗
PubMed1995

Age estimation in biopsy specimens of dentin.

Determination of age at death on the basis of aspartic acid racemization in dentin is one of the most reproducible and accurate methods. In Germany, age estimation by this method has so far generally not been applied to living persons, since the extraction of a tooth exclusively for age estimation when it is not medically indicated is regarded as ethically and legally problematic. The development of a biopsy technique applicable to dentin took place against this background. Testing the technique and analysis of dentinal biopsy specimens revealed that the biopsy technique is a low-risk procedure that causes only minor discomfort to the affected person. It is readily practicable and facilitates standardized specimen removal. The relationship between the extent of aspartic acid racemization in dentinal biopsy specimens and age is very close, facilitating age estimation. A prerequisite for accurate results is the performance of biopsies under strictly standardized conditions. If this is guaranteed, age determination on the basis of aspartic acid racemization in dentinal biopsy specimens appears to be superior in precision to most other methods in living persons and can be used for all age groups.

Adolescent↗
PubMed1994

Photometric measurement of pressure-induced blanching of livor mortis as an aid to estimating time of death. Application of a new system for quantifying pressure-induced blanching in lividity.

A newly developed digital system employs photometric measurement of pressure-induced blanching of livor mortis to estimate time of death. The conventional method of applying pressure with thumb or forceps relies largely on subjective interpretation. Our system improves on this method by photometric quantification of color changes produced by defined magnitudes of pressure. We tested the new system by applying increasing levels of pressure to lividity in 50 cadavers with known time of death. Characteristics courses for pressure-induced changes were found for the brightness component of livor mortis, revealing distinct differences between the respective postmortem intervals. The surface areas under these curves were then calculated and distributed into 10-hour postmortem time categories. Variance analysis of these surface values revealed clear differences between the time categories, especially in the medians. Distinct differences between the various postmortem time categories were also evident for the chroma component of livor mortis. The new system offers a further method--in addition to body temperature, rigor mortis, and the electrical responsiveness of skeletal muscles--for estimating time of death, especially after long postmortem intervals.

Equipment Design↗
PubMed1994

Magnetic resonance imaging of the brain during alcohol absorption and elimination--a study of the "rising tide phenomenon".

The absorption phase of alcohol is typically accompanied by more marked behavioral effects than the elimination phase. The mechanism behind this so-called "rising tide phenomenon" has not been fully elucidated. We hypothesized that the rising tide of alcohol during the absorption phase increases the permeability of the blood-brain barrier (BBB), thus elevating the free water content with consequent edema. The resulting increase in intracranial pressure, combined with alcohol's direct toxic effects, results in a synergetic reinforcement of the symptoms of intoxication. To test this hypothesis we performed proton magnetic resonance imaging (MRI) on the human brain during the alcohol absorption and elimination phases. Our results indicate that the alcohol-induced transient opening of the BBB is a possible factor behind the rising tide phenomenon.

Adult↗