Mari Taniguchi

Comparative study on the chronology of third molar mineralization in a Japanese and a German population

In Germany, a sharp increase in forensic age estimations of living persons has been observed in recent years. German law defines four legally relevant age limits: 14, 16, 18 and 21 years. In these age groups, radiographic assessment of the mineralization status of third molars is of particular importance. So far, the influence of ethnicity on the mineralization rate has been insufficiently analyzed. A total of 3031 orthopantomograms of 1597 Japanese and 1434 Germans aged between 12 and 26 years were examined. The mineralization status of third molars was evaluated on the basis of the classification proposed by Demirjian. For the individual mineralization stages, the study presents the mean values and standard deviations (SD) separately for both populations and sexes. The majority of probands from both the Japanese and the German population achieved the C stage and the late G and H stages of third molar development at similar ages. Significant differences between Japanese and Germans were observed, however, with regard to the D, E and F stages defined by Demirjian. Japanese men and women achieved the D, E and F stages approximately 2-3 years later than German men and women. In addition to forensic age determination in living persons, the presented reference data can also be used for age estimations of unidentified deceased persons and skeletons.

Postmortem serum uric acid and creatinine levels in relation to the causes of death

Serum uric acid (UA) and creatinine (Cr) mainly derive from skeletal muscle tissues. Although, remarkable postmortem stability of the serum levels has been reported, there appears to be very poor knowledge of the diagnostic value in investigation of death, except for uremia. The aim of the present study was to evaluate postmortem serum UA and Cr levels using 395 forensic autopsy cases, in comparison with blood urea nitrogen (BUN), for investigation of the pathophysiology of death with special regard to the causes of death involving possible skeletal muscle damage, e.g. due to hypoxia, heat or agonal convulsions. Cr and BUN showed relatively good topographic stability in the cadaveric blood, whereas, UA was often much higher in the right heart blood than in the left heart and peripheral blood, independent of postmortem intervals. Moderate to marked elevation of Cr and BUN accompanied with hyperuricemia was observed in delayed death. In the acute death cases (survival time <30 min), UA, especially in the right heart blood, showed a considerable elevation in mechanical asphyxiation and drowning. The Cr level in fire victims with a lower carboxyhemoglobin (COHb) level (<60%) was significantly higher than in those with the possible fatal level (>60%). A similar elevation of Cr was observed in fatalities from heat stroke and methamphetamine (MA) poisoning. The observations suggested that hyperuricemia in acute death may be indicative of advanced hypoxia and that elevated Cr level may reflect the skeletal muscle damage, especially due to thermal influence.

Possible postmortem serum markers for differentiation between fresh-, saltwater drowning and acute cardiac death: a preliminary investigation

The aim of the present study was to investigate the differences in postmortem blood biochemistry between fresh-, saltwater drowning and acute myocardial infarction/ischemia (AMI) (n=11, n=15 and n=23, respectively; postmortem interval <48 h). Left and right cardiac blood samples were examined for the serum markers: sodium (Na), chloride (Cl), magnesium (Mg), blood urea nitrogen (BUN), creatinine (Cr), pulmonary surfactant-associated protein A (SP-A) and cardiac troponin T (cTn-T). The most efficient markers were the left-right cardiac BUN ratio for determination of drowning (hemodilution) and the left heart blood Mg level for differentiation between fresh- and saltwater aspiration. A characteristic feature of saltwater drowning was a low left-right BUN ratio and a marked elevation in the serum Cl, Mg and Ca levels of the left heart blood. Serum cTn-T level was usually low in drownings, showing a difference from most cases of AMI. Freshwater drowning showed a significant elevation of serum SP-A, although there was considerable overlapping with saltwater drowning and AMI. These findings suggested the usefulness of serum markers in the investigation of death from drownings.

Postmortem lung weight in drownings: a comparison with acute asphyxiation and cardiac death

There are several controversial findings and arguments about the lung weight as a marker of drowning. The aim of the present study was to examine the difference in the lung weight and the amount of pleural effusion between freshwater and saltwater drownings (n=70 and n=75, respectively), in comparison with asphyxiation (n=85) and acute cardiac death (n=82), for the diagnosis of drowning. In drowning cases, a gradual postmortem time-dependent decrease in the lung weight and a reciprocal increase in the pleural effusion suggested postmortem transudation from the lungs. The decrease in the total value of the combined lung weight and the amount of pleural effusion was marked in saltwater immersion after 3 days postmortem, suggesting a leakage of the effusion out of the thoracic cavity under an osmotic effect of the immersion medium. In cases within 3 days postmortem, when the combined lung weight and amount of pleural effusion were added to estimate possible combined lung weight at the time of death, there was a gross difference among the causes of death: the value was the largest in saltwater drowning, followed by freshwater drowning, acute cardiac death and asphyxiation. However, the value depended on the gender and age of the subjects, suggesting a relation to the individual physical constitution and survival time or vital activity. These factors should be taken into consideration in evaluation of the lung weight in the diagnosis of drownings.

Intranuclear ubiquitin immunoreactivity of the pigmented neurons of the substantia nigra in fatal acute mechanical asphyxiation and drowning

Abstract To evaluate the significance of immunohistochemical staining of ubiquitin (heat shock protein) in the midbrain for the medico-legal diagnosis of fatal asphyxiation and drowning, we investigated forensic autopsy cases of fatal mechanical asphyxia (n = 18), manual/ligature strangulation (n = 9), hanging (n = 4), aspiration/choking (n = 5) and drowning (n = 16). These were compared to control groups (n = 30) consisting of fatalities from brainstem injury (n = 12) and acute myocardial infarction (n = 18). Ubiquitin was clearly demonstrated in the nuclei of pigmented substantia nigra neurons, showing two intranuclear staining patterns: a type of inclusion (possibly Marinesco bodies) and a diffuse staining. The diffuse staining was significantly more frequently observed in cases of drowning. The percentage of total ubiquitin positive neurons was frequently higher in strangulation (5.1– 28.4%, mean 17.0%), aspiration/choking (5.3–32.0%, mean 17.6%) and drowning (7.0–34.1%, mean 19.8%), but relatively low in hanging (5.1–12.7%, mean 8.6%), brainstem injury (0–10.4%, mean 5.0%) and acute myocardial infarction (1.5–16.9%, mean 8.3%). These observations suggest that intranuclear ubiquitin immunoreactivity of the pigmented substantia nigra neurons in the midbrain was induced by a fatal severe stress on the central nervous system in asphyxiation and drowning.

Pulmonary immunohistochemistry and serum levels of a surfactant-associated protein A in fatal drowning

To evaluate the immunohistochemical distribution and serum levels of a pulmonary surfactant-associated protein A (SP-A) in fatal drowning with regard to the pulmonary alveolar injury, 53 autopsy cases were investigated. SP-A was membranously or linearly demonstrated in varying intensities on the intra-alveolar interior surface and on the interface of the intra-alveolar effusion. A high score of intra-alveolar aggregates of SP-A was significantly more frequently observed in freshwater than saltwater drowning. The left/right ratios of cardiac blood SP-A level were significantly high both in fresh- and saltwater drowning, showing no relationship to aggregated SP-A scores. Immunohistochemical score and serum level of SP-A were independent of the lung weight or pleural effusion. These observations suggest a partial difference of pulmonary pathophysiology depending on the immersion medium in fatal drowning.

Post-mortem urinary myoglobin levels with reference to the causes of death.

To evaluate pathophysiological significance of post-mortem urinary myoglobin levels in determining the cause of death, we investigated 210 forensic autopsy cases, partially in comparison with serum levels. Post-mortem serum myoglobin levels were extraordinary high in most cases possibly due to post-mortem change. Urinary myoglobin levels did not correlate with the serum levels, showing possible post-mortem elevation in cases of a prolonged post-mortem period over 48h. A high (>1000 ng/ml), moderate (100-1000 ng/ml), slight (50-100 ng/ml) and not significant (<50 ng/ml) elevation of urinary myoglobin were observed in 26, 43, 31 and 110 cases, respectively. Half the highly elevated cases were those with a survival time over 24h. In cases of minor muscle injury such as head trauma, elevation of urinary myoglobin level was closely related to longer survival. In acute/subacute deaths with a post-mortem interval within 48h, a significant difference was observed in relation to the blood carboxyhemoglobin (COHb) levels of fire victims: myoglobinuria over 100 ng/ml was more frequently and markedly observed in cases with COHb below 60% than over 60%, suggesting muscle damage in fatal burns. Similar elevation was observed in heat stroke victims, and also in some cases of acute and subacute death from polytrauma, asphyxiation, drowning, electricity and spontaneous cerebral bleeding, but not in myocardial infarction. Thus, it was suggested that high post-mortem urinary myoglobin levels in acute and subacute death cases may be a possible indicator of antemortem massive skeletal muscle damage as well as exertional muscle hyperactivity or convulsive disorders associated with hypoxia.

Pulmonary surfactant-associated protein A as a marker of respiratory distress in forensic pathology: assessment of the immunohistochemical and biochemical findings

The aim of the present study was to review the immunohistochemical and biochemical findings with reference to the causes of death in routine casework (total, n=492). In the immunohistochemistry (n=283), an increase in intra-alveolar granular SP-A (SP-A score) was often observed in asphyxiation (n=21/34, 61.8%) and freshwater drowning (n=15/24, 62.5%), and also in fire and methamphetamine (MA) fatalities (n=22/76, 28.9% and n=5/16, 31.3%). Serum SP-A level (n=134) was elevated in acute respiratory distress syndrome and in some cases of drowning, fire and MA fatalities, hyperthermia and chest traumas. A quantitative analysis of SP-A subclass-gene expression (SP-A1/A2 mRNA) in the lung tissue specimens (n=126) revealed an increase in the SP-A1/A2 mRNA ratio in asphyxiation (n=17/21, 80.9%), freshwater drowning (n=7/9, 77.7%), fire and MA fatalities (n=20/35, 57.1% and n=8/10, 80.0%). These findings suggested the usefulness of SP-A as a marker of asphyxiation, respiratory distress and alveolar injury.

Immunohistochemical investigation of pulmonary surfactant-associated protein A in fire victims

To evaluate the forensic pathological significance of the immunohistochemical distribution of pulmonary surfactant-associated protein A (SP-A) in determining the cause of death in fires, 57 fire victims were examined by scoring the staining intensity. The highest SP-A score with dense granular deposits (aggregates) in the intra-alveolar space was frequently observed in cases with a lower blood carboxyhemoglobin (COHb) level (<60%). The SP-A score was relatively low in carbon monoxide intoxication due to causes other than fires. High SP-A scores showed a relation to the serum level and in part related to the bloody exudate in the lower airway. These observations suggested that the increase in SP-A in fire victims may be mainly related to pulmonary alveolar injury due to the inhalation of hot air and/or irritant gases rather than hypoxia.

Decapitation in suicidal hanging — a case report with a review of the literature

We report a case of self-decapitation by suicidal hanging from a river bridge and discuss the decapitation mechanism, reviewing the literature. The torso and the head of the victim, respectively, were found apart in a river approximately 100 m and 600 m, respectively, downstream from the bridge in two days. Morphological, serological and DNA analyses confirmed their identity. Torn ligaments between the atlas and axis accompanied by fractures in the axis at the partes interarticulares were indicative of a traction force combined with anteroflexion of the head by falling from a height, and the radial pressure due to a strong, single twisted nylon rope with a slip knot was considered to have contributed considerably to the subsequent skin laceration with wavy marginal abrasions. In the reviewed literature, cervical spine fractures were described only in two of six cases, suggesting head movement at the time of decapitation.