H. J. Kaatsch

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

Abstract 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.

Quality assurance in age estimation based on aspartic acid racemisation

Abstract 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 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.

IMPROVED DNA TYPING OF HUMAN URINE BY ADDING EDTA

Abstract 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.

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.

SummaryA 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. Characteristic 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.ZusammenfassungEin neu entwickeltes Meßgerät erfaßt kraft- und farbmetrisch die Wegdrückbarkeit von Totenflecken und ersetzt die bisherige subjektive Methode, die Abblassung von livores auf Daumen- oder Pinzettendruck zu beurteilen. Die Farbänderung der Totenflecke wird computergesteuert bei definiert ansteigendem Druck gemessen und in Relation zur jeweiligen Druckstärke ausgewertet. Bei der Untersuchung der Wegdrückbarkeit an 50 Leichen zeigten sich charakteristische Kurvenverläufe der druckbedingten Veränderung der Helligkeitsanteile in der Farbe von livores für verschiedene postmortale Intervalle. Errechnet man die Flächen unter diesen Helligkeits-Verlaufskurven und faßt diese in Zeitklassen p.m. (10-Stunden-Intervalle) zusammen, ergibt die Varianzanalyse Unterschiede der Meßwerte — vor allem des Medians -zwischen den einzelnen Zeitklassen. Auch bei den Buntheitsanteilen in der Farbe von Totenflecken sind die Meßergebnisse für verschiedene Zeitklassen voneinander abgrenzbar. Die neue Methode objektiviert das Verhalten von livores auf Druck anhand der Quantifizierung physikalischer Meßgrößen und ergänzt die bestehenden Methoden zur Todeszeitbestimmung. Darüberhinaus eröffnet das Meßsystem neue Ansätze der Todeszeitschätzung für länger zurückliegende Todeszeitpunkte, bei denen die Messung des Temperaturabfalls, bzw. der elektrischen Erregbarkeit der Muskulatur weniger zum Tragen kommt.

DNA typing in cases of blood chimerism

Abstract 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.

Fatal intoxication with a decalcifying agent containing formic acid

Abstract 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 μg/ml, which declined to 13.9 μg/ml after 6.5 h of haemodialysis. Post-mortem concentrations were 855.4 μg/ml (heart blood), 2712 μg/ml (gastric contents), 1128 μg/ml (haemorrhagic fluid from abdominal cavity), 3051 μg/ml (bile), 2664 μg/ml (contents of small intestine), 442.7 μg/g (liver) and 542.3 μg/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.

Beeinträchtigung der Sicherheit im Schiffsverkehr durch Alkohol Einfluss auf das Visuelle System

ZusammenfassungHintergrund. Es gibt derzeit keinen verbindlichen Grenzwert für die Blutalkoholkonzentration, ab dem eine Fahruntüchtigkeit im Schiffsverkehr angenommen werden muss und damit eine Bestrafung wegen Trunkenheit nach dem Strafgesetzbuch begründet werden kann. Ziel unseres interdisziplinären Projektes war die Erarbeitung von Datenmaterial, um medizinisch gesicherte Grenzwerte vorzuschlagen. Material und Methode. Der Einfluss von Alkohol auf das visuelle System und die Fähigkeit, ein Schiff zu führen,wurden an 21 Kapitänen im Schiffssimulator getestet. Es wurden nüchtern und alkoholisiert Fern- und Nahvisus,Binokularfunktion, Farben- und Dämmerungssehen sowie die Akkommodationsbreite geprüft. Ergebnisse. Bei der Fahrt im alkoholisierten Zustand (durchschnittlich 1,08‰ Blutalkoholkonzentration) zeigten alle Kapitäne nautische Fehler bzw.Fehleinschätzungen von Gefahrensituationen. Es fanden sich keine Beeinträchtigungen von Visus und Binokularfunktion. Die Akkommodationsbreite nahm durchschnittlich um 18% (p=0,0001) ab, im Farblegetest wurden alkoholisiert mehr Fehler (p=0,017) gemacht und mehr Zeit (p=0,004) benötigt. Schlussfolgerung. Die reduzierte Leistungsfähigkeit aller Probanden bei einer Blutalkoholkonzentration von ca.1‰ belegt das hohe Risikopotenzial von Alkohol im Schiffsverkehr und damit die begründete Annahme, dass Schiffsführer bei dieser Blutalkoholkonzentration fahruntüchtig sind.AbstractBackground. 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‰) 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.

Beeinträchtigung der Sicherheit im Schiffsverkehr durch Alkohol

ZusammenfassungHintergrund. Im Rahmen eines interdisziplinären Projektes (Ophthalmologie,Rechtsmedizin, Innere Medizin,Psychologie und Nautik) wurden Daten erhoben, um medizinisch gesicherte Blutalkoholgrenzwerte für die Schifffahrt zu empfehlen. Methoden. In der Schiffssimulationsanlage wurden an 21 erfahrene Kapitäne im nüchternen und im alkoholisierten Zustand (Zielalkoholkonzentration im Blut: 1,0‰) realitätsnahe nautische Anforderungen gestellt. Nach den simulierten Fahrten wurden mittels Pupillographie Pupillenlichtreflex, spontane Pupillenbewegung, sakkadische Augenbewegung und Nystagmus sowie nach Modifikation des Gerätes der optokinetische Nystagmus ausgewertet. Ergebnisse. Bei der Messung des Pupillenlichtreflexes fanden sich unter Alkohol: eine Verkürzung der relativen Kontraktionsamplitude, eine Verlängerung der Latenzzeit, eine Verlangsamung der Kontraktionsgeschwindigkeit sowie eine geringere Amplitude.Eine verminderte Konzentration im alkoholisierten Zustand ließ sich bei allen Kapitänen durch die Prüfung des OKN nachweisen. Schlussfolgerungen. Die Pupillographie ist eine geeignete Methode, Einflüsse von Alkohol auf vegetative Funktionen und Fahrtauglichkeit in der Schifffahrt zu erfassen.Vergleichende Betrachtungen des Einflusses von Alkohol auf Pupillenreaktion und Augenbewegung sowie auf nautische Leistungen zeigten z.T. deutliche Funktionsausfälle bei einer Blutalkoholkonzentration von 1,0‰.AbstractObjective. 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‰).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‰ may exclude safe navigation.

Measurement of digitalis-glycoside levels in ocular tissues: A way to improve postmortem diagnosis of lethal digitalis-glycoside poisoning? II. Digitoxin*

SummaryPrompted by animal studies reporting the accumulation of digitalis-glycosides in ocular tissues, we investigated whether measurement of digoxin levels in human ocular tissues can improve the postmortem diagnosis of lethal digoxin intoxication. Digoxin was measured in the vitreous humor and choroid-retina of patients who had received in-patient treatment with digoxin prior to death (therapeutic group) and in a single case of suicidal intoxication. The results were compared with the digoxin levels in the femoral vein blood, myocardium, kidney and liver, and evaluated in light of the medical history of each patient. In the therapeutic group the mean digoxin level was higher in the choroid-retina than in other tissues and body fluids. The range of variation in levels in the choroid-retina following therapeutic doses was comparable to that in the other tissues. An extremely high level of digoxin was present in the choroid-retina in the case of suicidal intoxication. In all cases, levels in the vitreous humor were very low compared to those in the choroid-retina. Hence, it is unlikely that significant distortion of choroid-retinal levels occurs due to postmortem diffusion of digoxin into the vitreous body. Our results indicate that measurement of digoxin levels in the choroid-retina can aid the postmortem diagnosis of lethal digoxin intoxication.ZusammenfassungNachdem von anderen Autoren tierexperimentell hohe Digitalisglykosidkonzentrationen in okulären Geweben nachgewiesen werden konnten, sollte die Frage geklärt werden, ob durch Bestimmung der Digoxinspiegel in Augengeweben ein Beitrag zur Verbesserung der postmortalen Diagnostik von tödlichen Digoxinintoxikationen geleistet werden kann. Bei mit Digoxin behandelten, in Kliniken verstorbenen Patienten (therapeutisches Kollektiv) sowie in einem Fall einer suicidalen Vergiftung wurden Digoxinkonzentrationen in Glaskörperflüssigkeit und Choroidretina bestimmt. Die in den okulären Geweben bestimmten Werte wurden den Digoxinspiegeln in Femoralvenenblut, Myocard, Niere und Leber gegenübergestellt und unter Berücksichtigung anamnestischer Daten interpretiert. In der Choroidretina wurden im therapeutischen Kollektiv Digoxinkonzentrationen gefunden, die im Mittel deutlich über den in den übrigen Organen bestimmten Werten lagen. Die Streuung der Choroidretinakonzentrationen nach therapeutischer Dosierung war mit der Streuung der übrigen Gewebespiegel vergleichbar. In dem Intoxikationsfall wurde eine ausgesprochen hohe Choroidretinakonzentration festgestellt. Im Vergleich zu den Choroidretinawerten waren die Glaskörperflüssigkeitsspiegel in allen Fällen sehr niedrig; mit einer wesentlichen Verfälschung der Choroidretinakonzentrationen durch eine mögliche Diffusion des Digoxins in den Glaskörper ist danach nicht zu rechnen. Nach unseren Untersuchungsergebnissen ist die Bestimmung des Digoxinspiegels in der Choroidretina in fraglichen Vergiftungsfällen sinnvoll.