Naomi Sameshima

Electrolyte analysis of pleural effusion as an indicator of drowning in seawater and freshwater

It is important for forensic pathologists to determine the diagnosis of drowning as well as the site of drowning. In a previous study, we propose that analysis of electrolytes in pleural effusion from rats may be useful for determining whether drowning has occurred in seawater or freshwater. To test this proposal, we measured the concentration of sodium, potassium and chloride ions and total protein in pleural effusion from 40 autopsy cases: 24 involving seawater drowning, 9 freshwater drowning and 7 no drowning. The concentrations of sodium and chloride ions in pleural effusion showed a significant difference between seawater drowning and freshwater drowning. The concentration of potassium ions and total protein showed no difference between each group, although they increased in proportion to the postmortem interval in cases of both seawater and freshwater drowning. These results are almost same as our previous study and, thus, the quantitative analysis of electrolytes in pleural effusion may be useful for determining whether drowning has occurred in seawater or freshwater.

Estimation of postmortem interval based on the spectrophotometric analysis of postmortem lividity

The color of postmortem lividity and control skin in 21 adult cadavers whose postmortem interval was within 72h, was measured by spectrophotometry in order to estimate the postmortem interval, objectively. The L *a *b * system, which has been widely used for the digital expression of skin color, was used and linear regression analysis was performed to determine the relationship between the postmortem interval and 31 color factors including L * (Value), a * and b * (Chroma and Hue) and C * (Chroma). The difference in Chroma between postmortem lividity and control skin (DeltaC * and DeltaC( *)/C(c)( *)) was only weakly correlated with the postmortem interval. We propose a new equation for calculating the postmortem interval using several color factors obtained by measurement of postmortem lividity, together with some autopsy findings that are known to affect the formation of postmortem lividity. The new equation makes it possible to estimate the postmortem interval within +/-4.76h.

Vulnerability of experimentally induced fatty liver to heat stress in rats

BackgroundThe aim of this study was to confirm the vulnerability of fatty liver to heat stress using fatty liver rats from the viewpoint of the induction of apoptosis.MethodsWe exposed rats with and without a fatty liver to heat stress and then looked for apoptotic cells within the liver tissue using two apoptosis detection kits. We also determined the mRNA expression of heat shock protein (HSP) 70, caspase-3, bcl-2, and bax using a quantitative reverse transcription-polymerase chain reaction method.ResultsFollowing heat stress, apoptosis was strongly visible in the fatty liver comparing with that noted in the normal liver. The expression of HSP70 was increased following heat stress in both livers, but the volume of its expression was significantly less in the fatty liver than in the normal liver. The ratio of bcl-2/bax expression tended to increase in the normal liver but decrease in the fatty liver following heat stress. Caspase-3 demonstrated no significant change following heat stress in both livers.ConclusionsThe detection of apoptosis, together with changes in the mRNA expression of HSP70 and the expression ratio bcl-2/bax mRNA may indicate vulnerability of a fatty liver to heat stress and may support the hypothesis that morphologic change is induced in a fatty liver by exposure to heat stress. These results suggest that fatty liver may be more vulnerable to heat stress than normal liver.

Rapid and reliable screening method for detection of 70 pesticides in whole blood by gas chromatography–mass spectrometry using a constructed calibration-locking database

Pesticide poisoning is one of the most common causes of death by poisoning in Japan, and various kinds of pesticides including organophosphates, carbamates and pyrethroids are listed as causative substances. The purpose of our study was to develop a rapid and reliable screening method for various kinds of pesticides in whole blood by using a unique calibration-locking database and gas chromatography-mass spectrometry. A database of 70 pesticides was constructed using NAGINATA™ software with parameters such as mass spectrum, retention time and qualifier ion/target ion ratio (QT ratio) and calibration curve. Diazepam-d(5) was used as the internal standard for construction of each calibration curve within the range of 0.01-5.0 μg/ml. We examined the applicability of the constructed database by analyzing whole blood samples spiked with 70 pesticides. The pesticides in blood were extracted with hexane under acidic conditions or with an enhanced polymer column (Focus™), subjected to GC-MS, and screened by the pesticides database. Among the 70 pesticides examined, 66 and 62 were successfully identified at the level of 1 and 0.1 μg/ml, respectively, by hexane and 63 and 51 were identified by the Focus column without the use of standard compounds. The time required for data analysis was significantly reduced. Since the established method can produce qualitative and semi-quantitative data without the need for standard substances, this new screening method using NAGINATA™ should be useful for confirming the presence of pesticides in blood in future clinical and forensic cases.

Reliable determination of cyanide, thiocyanate and azide in human whole blood by GC–MS, and its application in NAGINATA–GC–MS screening

PurposeCyanide, its metabolite thiocyanate and azide in human biological fluids are commonly analyzed by gas chromatography–mass spectrometry (GC–MS) after derivatization with pentafluorobenzyl bromide using extractive alkylation. However, the reported methods have some drawbacks. We examined each step of these reported methods and attempted to establish a more reliable method to determine the levels of the above compounds in human whole blood. We also examined the applicability of the established method to NAGINATA–GC–MS screening.MethodsThe deproteinization method, internal standard (IS), the cause of column damage, and the effect of the addition of ascorbic acid were examined, and the best procedure was selected. The obtained data, including mass specta, retention times and calibration curves were registered to the database of NAGINATA software.ResultsThe analysis of cyanide in whole blood was possible only when the blood was deproteinized with trichloroacetic acid. A high recovery of thiocyanate and azide was obtained without the deproteinization step. K13C15N (for cyanide) and tribromobenzene (for thiocyanate and azide) were selected as ISs. The column damage caused by the phase transfer catalyst was successfully eliminated by passing the catalyst containing solution through an ethyl benzoic sulfonic silica gel column. By these improvements, a more reliable determination method was established. All anions were rapidly identified using NAGINATA software, and the approximate concentration of each compound in whole blood was obtained at the same time.ConclusionsBecause NAGINATA–GC–MS screening can rapidly identify these poisons without using toxic compounds as reference standards, it should be useful in forensic and emergency medicine laboratories.

A familial case of ABO phenotype-genotype discrepancy.

In the present study, we detected a familial case of ABO phenotype-genotype discrepancy. Although the observed phenotypes were B and O, the corresponding ABO genotypes were AB and AOG, respectively, by routine examination. Exons 6 and 7 of the ABO gene were sequenced and subsequently, the sequence of the allele responsible for ABO phenotype-genotype discrepancy was examined. Our results indicated that the Ax allele was present in 3 family members. By employing traditional serological methods, we further identified and confirmed that the allele Ax and the resulting Ax phenotype are responsible for ABO phenotype-genotype discrepancy.

An autopsy case of misdiagnosis based on postmortem computed tomography findings.

A middle-aged man was found lying beside his bicycle on an early winter morning. The cause of death was diagnosed by clinicians as traumatic intracerebral hemorrhage and cerebral contusion with frontal bone fracture based on the findings of Computed Tomography (CT) of the head. However, forensic autopsy revealed that there were no evidences of intracerebral hemorrhage and left frontal bone fracture but the defect of golf ball size on the frontal lobe which was considered to be a complication from the old cerebral contusion and old bone fracture. The bleeding and pooling blood from subarachnoid hemorrhage (SAH) to the frontal lobe defect had the appearance of an intracerebral hemorrhage. Disruption of left renal artery was found and the cause of death was diagnosed as massive hemorrhage due to this rupture. Although postmortem CT is a useful tool for obtaining information on the body prior to conducting an autopsy, it should be used with extreme caution.