Right Heart Blood Research Articles

Cyanide concentrations in blood and tissues of fire victims.

Cyanide poisoning has been regarded to contribute the fatal outcome in fire victims. The toxicity of inhaled hydrogen cyanide (HCN) at the cellular level was evaluated considering the impact of methemoglobin (MetHb) produced by fire gases. Cyanide (CN) concentrations and total hemoglobin contents were measured in right heart blood (RHB) and seven organs/tissues (basal ganglia, brain stem, heart, lung, liver, kidney and psoas muscle) collected from 20 fire fatalities. MetHb and carboxyhemoglobin saturations were also measured in RHB. The amount of CN probably bound to the cytochrome c oxidase of the tissue cells (CCO-CN) was extrapolated from CN and hemoglobin contents in RHB and organs/tissues, MetHb saturation in RHB and binding capacity of MetHb for CN. CN concentrations in RHB showed a wide range with the highest concentration of 8.927 μg/mL. The lung contained the largest CN content among organs/tissues with the mean concentration of 2.219 μg/g, then the heart (0.259 μg/g) and it was lower than 0.100 μg/g in others. Exceedingly large amount of CN in the lung could be explained by high hemoglobin content, being the port of entry of HCN and postmortem diffusion of fire gases. CCO-CN was theoretically present in about 20% of organ/tissue samples, most commonly in the basal ganglia (10 samples, with the mean of 0.059 μg/g) followed by heart (eight samples, with the mean of 0.109 μg/g). No CCO-CN was found in liver and kidney. HCN might have the effect on brain and heart.

Thyroglobulin Level in Postmortem Blood Samples as a Diagnostic Tool for Cause of Death

There were many conflicting results about the significance of postmortem thyroglobulin (Tg) level as a biomarker in forensic diagnosis. This work aimed to assess the relation between postmortem blood Tg level and the cause of death. Sixty cadavers received at Cairo Department of Forensic Medicine (Zenhum Morgue), Egypt, were classified into two groups; 1st group included 30 cadavers died by different types of asphyxia, and 2nd group included 30 cadavers died by causes other than asphyxia. In all cases, right heart blood (RHB) and left heart blood (LHB) Tg levels were measured using chemiluminescence immunometric assay and thyroid tissues were histopathlogically examined. Thyroglobulin level was high in 76.6% of 1st group cases and in 83.3% of 2nd group cases. In fatal traumatic brain injury cases, there was a significant positive correlation between Tg level and survival period. The mean value of RHB Tg levels was higher than that of LHB Tg levels in both studied groups while Tg was high in all cases with skin discoloration as a sign of putrefaction regardless of the cause of death. In conclusion, thyroglobulin level is unreliable as a diagnostic tool for cause of death because it may be affected by postmortem changes.

Appropriate blood sampling sites for measuring Tg concentrations for forensic diagnosis.

Previous studies have reported that thyroglobulin (Tg) concentrations in heart blood are high in cases of asphyxia caused by neck compression such as hanging, strangulation, and throttling and in those with fatal traumatic brain injuries. However, even in cases without these findings presumed to increase the Tg concentration in the previous studies, we previously reported that in some cases the Tg concentration in right heart blood (RHB) and left heart blood (LHB) exceeded the standard value for diagnosis (200 ng/mL) defined in previous studies and the Tg concentration in RHB was significantly higher than that in LHB. In the present study, in our 46 forensic autopsy cases without findings presumed to increase Tg concentration, we separately collected external iliac venous blood (IVB) and external iliac arterial blood (IAB) in addition to RHB and LHB, measured Tg concentrations in RHB, LHB, IVB, and LAB (TRHB, TLHB, TIVB, and TIAB, respectively), and investigated the appropriate blood sampling site for measuring Tg concentrations for forensic diagnosis. TRHB, TLHB, TIVB, and TIAB were 386.3 ± 674.1, 105.8 ± 179.0, 109.2 ± 166.8, and 43.7 ± 90.9 ng/mL, respectively. There were statistically significant differences between TRHB and TLHB, TIVB and TIAB, TRHB and TIVB, and TLHB and TIAB. Tg is more readily diffused by the venous system (RHB, IVB) than by the arterial system (LHB, IAB) because the venous system retains more blood volume after death. Tg is more readily diffused to heart blood (RHB, LHB) than to peripheral blood (IVB, IAB) because of the proximity of the heart to the thyroid gland. Therefore, we conclude that Tg leaks into the vessels around the thyroid gland because of the influences of postmortem changes and subsequently diffuses through the blood after death, and therefore the Tg concentration increases after death. When Tg concentration values are used for forensic diagnosis, it is appropriate to measure them using peripheral arterial blood situated distant from the thyroid gland.

Unreliability of the use of thyroglobulin concentration in postmortem blood samples in forensic diagnosis

Previous studies have reported that the concentration of thyroglobulin (Tg) in heart blood is high in cases of asphyxia by neck compression such as hanging, strangulation, and throttling and in those with traumatic injuries to the head. However, we have experienced cases in which we observed high Tg concentrations without such findings. Therefore, we analyzed the influence of postmortem changes on Tg concentration. Of 253 forensic autopsies conducted at our institution, we analyzed 44 cases without the findings presumed to increase Tg concentration. We collected right heart blood (RHB) and left heart blood (LHB) separately and measured Tg concentrations in each. The Tg concentration of the RHB in 19 (43%) cases and that of the LHB in 10 (23%) cases was higher than the standard value (200ng/ml) obtained in previous studies. In some cases, we found large differences between the Tg concentrations of RHB and LHB. We suggest that Tg concentration can increase above the standard value and that a difference between the Tg concentration of RHB and LHB arises as a result of postmortem changes. Consequently, if there is a large difference between the Tg concentration of RHB and LHB, the concentration of Tg should not be used as a basis for forensic diagnosis.