Sudden unexpected death from cardiac concussion (commotio cordis) with unusual legal complications

Sudden and unexpected death may result from cardiac concussion following blunt force trauma to the thorax. Undiagnosed pathologic disease must be carefully evaluated as a possible contributory element. Legal complications may arise from any autopsy. It is recommended that a photograph be taken upon completion of the autopsy. This photograph and adequate records can be used to refute any charges against the pathologist or assistants for the poor condition of a body after its release.     

Micromethod for MN antigen grouping of dried bloodstains

A micromethod based on the absorption elution technique was shown to be applicable to the detection of M and N blood groups of dried bloodstains on cotton cloth. Each antigen M and N was tested using two different types of antisera. Two hundred different bloodstains, stored up to six months, were analyzed. Conclusive results were obtained for M typing on 2.5-mm-long bloodstained threads. For N typing, some cross-reactivity of homozygous M stains with anti-N sera was observed. This may be explained by the structure of the M and N antigens on the red cell membrane.     

Identification of mechanical asphyxiation in cases of attempted masking of the homicide

Five homicides are described that had remained unexplained as to the causes of death after gross pathology. Although general signs of asphyxiation were present, they were lacking injuries specific of strangulation or oro-nasal occlusion. The diagnoses of asphyxiation were established by microscopical investigation of the lung and confirmed by subsequent police inquiries. An oro-nasal occlusion was involved in three cases, a strangulation or an oro-nasal occlusion, in another case. The victims were young and healthy. Toxicological investigations remained negative in four cases; one victim was anaesthetized by bromazepam and ether and had a blood alcohol concentration of 80 mg/100 ml. Lung histology and electron microscopy revealed acute emphysema, the development of a haemorrhagic-dysoric syndrome and a microembolism syndrome. With regard to the haemorrhagic-dysoric syndrome, the development of alveolar-interstitial edema is particularly important. This finding may also be diagnosed by light microscopy in semi-thin sections. It is emphasized that the combined action of several pathomechanisms is responsible for the rapid manifestation of the pulmonary lesions. Especially, the haemorrhagic-dysoric syndrome is brought about by the combined action of inspiratory intrapulmonary vacuum and raised intracapillary pressure. The complex pattern allows to compile the diagnosis of mechanical asphyxia even if there is no corresponding injury.     

Colorimetric measurements on small paint fragments using microspectrophotometry

The use of the Nanospec 10S microspectrophotometer (Nanometrics Inc.) as a colour-coding instrument for small paint fragments and individual layers within a layer structure is described.The CIE system of colour notation is discussed and numerical values for colours within the CIE system are derived from reflectance measurements made with the microspectrophotometer.     

Age estimation from the rib by phase analysis: white females

Metamorphosis at the sternal extremity of the rib has already been established as a reliable indicator of age at death. Using a sample of white males, it was shown that an accurate estimation of age can be made by direct examination of the bone itself. However, because of sexual differences in hormonal production and dimorphism in the skeleton, the present study was carried out to develop an appropriate standard for age determination from the sternal rib in white females. The sample consisted of 86 ribs of known age, sex, and race. Observations were made at the costochondral junction with special attention to pit formation (its shape and depth), changes in the walls and rim surrounding it, and overall bone density and texture. Based on changes in these areas, the ribs were separated into nine phases (0 through 8). The most rapid metamorphosis occurred in Phases 1 through 4 (mean ages 14-28) with changes noticeable at 3 to 4 year intervals. After mean age 28, this process slowed, considerably expanding the interval between phases to 10 to 15 years. The female ribs showed both earlier initial pit formation and a different morphologic pattern of aging as compared with males. Statistical analysis revealed that the features chosen to delineate the phases are valid predictors of age. This study has shown that the sternal rib can provide an accurate estimation of age in females spanning a mean age of 14 to 76 years.     

Determination of total hemoglobin in forensic blood samples with special reference to carboxyhemoglobin analysis

For the determination of total hemoglobin (Hb) in blood containing elevated carboxyhemoglobin (COHb), a newly developed reagent containing a 100-fold concentration of ferricyanide (20 g/l) and a 2-fold concentration of Sterox SE was compared with a standard reagent (0.2 g/l ferricyanide), the reagent of van Kampen and Zijlstra, using forensic blood samples and experimentally heated blood samples. There were no significant differences between the spectra of hemiglobincyanide (HiCN) solution produced with our reagent and the van Kampen and Zijlstra reagent using experimentally heated blood samples. Although the spectra of HiCN changed gradually with increased heating time and with the passage of time after mixing, the absorbance at 540 nm (A540) did not change until at least 120 min for both the reagents. When forensic blood samples containing elevated COHb were mixed with the van Kampen and Zijlstra reagent, total-Hb concentrations determined 5 min after mixing were 10-20% higher than those determined after 180 min. The overestimates of total Hb determined after 5 min resulted in comparable underestimates of percentage saturation of COHb (COHb%) when COHb% was obtained from the ratio of COHb content, determined by gas chromatogrpahy, to total-Hb concentration in blood. However, there was an extremely good correlation between the values of total Hb in forensic blood samples determined with the van Kampen and Zijlstra reagent after 180 min and those determined with our reagent after 5 min. From the results obtained, our reagent proved to be suitable for the determination of total Hb in forensic science practice.     

A fatal interaction of methocarbamol and ethanol in an accidental poisoning

A case is presented of a fatal drug interaction caused by ingestion of methocarbamol (Robaxin) and ethanol. Methocarbamol is a carbamate derivative used as a muscle relaxant with sedative effects. Therapeutic concentrations of methocarbamol are reported to be 24 to 41 micrograms/mL. Biological fluids were screened for ethanol using the Abbott TDx system and quantitated by gas-liquid chromatography (GLC). Determination of methocarbamol concentrations in biological tissue homogenates and fluids were obtained by colorimetric analysis of diazotized methocarbamol. Blood ethanol concentration was 135 mg/dL (0.135% w/v) and urine ethanol was 249 mg/dL (0.249% w/v). Methocarbamol concentrations were: blood, 257 micrograms/mL; bile, 927 micrograms/L; urine, 255 micrograms/L; gastric, 3.7 g; liver, 459 micrograms/g; and kidney, 83 micrograms/g. The combination of ethanol and carbamates is contraindicated since acute alcohol intoxication combined with carbamate usage can lead to combined central nervous system depression as a result of the interactive sedative-hypnotic properties of the compounds.     

Transferrin polymorphism detected in human urine using isoelectric focusing followed by immunoblotting

Genetic polymorphism of transferrin (TF) was revealed in human urine by isoelectric focusing and immunoblotting on thin-layer polyacrylamide gels. Using this technique more than 300 urine samples were examined, and correct TF typing from a small volume of urine (approx. 0.5 ml) was achieved, in comparison with the results of direct grouping for plasma. Three common phenotypes, TF C1, C2-1 and C2, were differentiated. In addition, the rare types TF C1D, C2D, and C1B were observed. The frequencies of the TF alleles in our samples were found to be: TF*C1 = 0.7265, TF*C2 = 0.2624, TF*D = 0.0083 and TF*B = 0.0028.