Morphological changes in human head hair subjected to various drug testing decontamination strategies

Morphological changes in hair subjected to decontamination protocols were evaluated by scanning electron microscopy (SEM) as part of the National Laboratory Certification Program's (NLCP) efforts to develop proficiency testing materials in support of Federal Workplace Drug Testing programs. Hair from five different donors was evaluated. Hair samples were subjected to three decontamination protocols: (1) aqueous phosphate buffer, (2) methanol or (3) methylene chloride as models for aqueous, alcohol and polar organic solvent protocols, respectively. Under these protocols, samples of hair were treated for 225 min (aqueous), 15 min (alcohol), or 15 min (polar organic). After decontamination, hair strands were sputter coated with gold/palladium (AuPd) and observed by SEM. Modest lifting of cuticle scales was observed in hair treated with methanol and methylene chloride consistent with some changes to the cell membrane complex (CMC) between cuticle scales. Damage resulting from aqueous buffer treatment ranged from substantial degradation to apparent complete loss of cuticle scales. Fracture structures consistent with cuticle damage were also observed. Each decontamination protocol had a different impact on the cuticle of the hair shaft.     

Shampoo residue profiles in human head hair

Washing hair with shampoo results in an accumulation of shampoo components in the hair. Hair of individuals using different shampoos can be distinguished by analysis of shampoo residues. A method for extraction and analysis of such residues is presented. The hair is extracted using a methanol/water mixture, and the extract is analyzed by reverse-phase high-pressure liquid chromatography (HPLC). The detector system consists of two ultraviolet (UV) detectors connected in series. The method is nondestructive to hair and is sensitive enough to be applied to a single hair 5 to 10 cm in length. Residues from hair balsams are analyzed by this technique as well. The use of this method in forensic science examination of human head hair is demonstrated.     

Methadone concentrations in human hair of the head, axillary and pubic hair

The concentrations of methadone and its metabolites in the hair of the head, axillary and pubic hair obtained from patients receiving a daily maintenance doses, were determined. Comparison of the concentrations provides the highest values in the axillary hair, followed by pubic hair and the hair of the head.     

Postmortem changes in the levels of monoamine metabolites in human cerebrospinal fluid.

Four monoamine metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 3-methoxy-4-hydroxyphenylglycol (MHPG) and 5-hydroxyindoleacetic acid (5-HIAA), were determined in the cerebrospinal fluid (CSF) of cadavers, whose causes of death had been suicidal hanging (SH) or ischemic heart failure (IHF). The concentration of DOPAC increased in parallel with the increment of the postmortem interval (PMI) (r = 0.626), whereas the concentrations of HVA, MHPG and 5-HIAA did not. The correlation coefficient was further increased by considering each cause of death separately: i.e., SH, r = 0.761; IHF, r = 0.705. These findings suggest the possible usefulness of the DOPAC level in CSF for estimating PMI.     

The population of coloured fibres in human head hair.

In 2002 a population study of textile fibres in human hair was carried out using 26 volunteers in Cambridgeshire, UK. Over 12,000 fibres were recovered from a variety of hair lengths using low adhesive tape and classified according to colour, generic type and fibre length. The results of the study showed that the most common fibre colours were black/grey (48%), blue (29.1%) and red (12.7%), the least common being green, orange/brown and yellow which each accounted for less than 5% of the total. Natural fibres (mainly cotton) were predominant (72.3%) and man-made fibres were considerably less frequent. When colour and generic type were classified together, the most common combinations were black and blue cottons. The least common were the man-made fibre/colour combinations with the most frequent of these accounting for less than 7% of the sample. Fibre loads carried by long hair were found to be significantly less than that carried by short hair. The results of this study are in accordance with previous fibre population studies using other types of recipient surfaces and are likely to be influenced by factors such as seasonal and geographical variation.     

Triangle identified at the proximal end of femur: a new sex determinant

Deviating from the conventional measurements, the present study uses the points of traction epiphysis on the upper end the femur as a landmark for measurement. A triangle was drawn on the posterior aspect of the femur using the apex of two traction epiphyses and the lateral most point on the articular margin of head. The study was conducted on 200 male and 80 female femora belonging to Central India. The lengths of triangle, so drawn, yielded highly significant results. The measurements were further evaluated by discriminant function analysis. Employing a single variable attained a prediction accuracy of 85.5% for males and 81.3% for females. When the variables were combined into a function, the accuracy improved to 86.5% for males and 86.3% for females. One of the advantages of the measurements on the proximal end of femur is that they can be used on fragmented bone where the shaft and distal end are missing. The study has applied value in the field of forensic anthropology.     

Study of microinjuries to hair cuticle of human head by scanning electron microscopy

The author presents the data on microclues in the free edges of hair cuticles of human head: microinjuries, microdefects (cracks, breaks, clefts, large and small waves) in representatives of Asia, Africa, Latin America, and Eastern Europe. The studies were carried out by scanning electron microscopy. Microinjuries of cuticle cells forming during hair combing by different types of combs and as a result of "permanent" curling are described. Scanning electron microscopy at the optimal magnification of x 3000 is a highly informative method for investigating microinjuries to the hair cuticle as additional signs in expert evaluation of the hair.     

Postmortem changes in cytochrome c oxidase activity in various organs of the rat and in human heart

Cytochrome c oxidase (COX), a mitochondrial enzyme, is inactivated by cyanide or carbon monoxide (CO) intoxication. To test whether cytochrome c has potential as an indicator of these toxins in cadavers, we measured COX activity in the main organs of the rat, and in the human heart, at various times after death. Each tissue sample or organ was homogenized and the COX activity in the mitochondrial fraction was measured using ferrous cytochrome c as the substrate. COX activity was significantly higher in rat brain, heart and kidney than in lung and liver from 0 to 4 days after death. The loss of COX activity was significantly slower in the brain and heart than in the lung, liver and kidney. Most importantly, COX activity correlated with the time-since-death for each of the rat organs we tested (r2=0.70-0.95), but for the human heart (r2=0.47). It may be possible that COX activity is likely to be a useful indicator of the time-since-death, and is worth pursuing as an indicator of the tissue cyanide and CO content.     

Postmortem changes of human bodies on the bathyal sea floor--two cases of aircraft accidents above the open sea

Forensic taphonomy in the marine context recently received growing attention. However, only limited information is available about the fate of human bodies at greater sea depth. Following two fatal aircraft accidents (west of Namibia, south of Sicily) human remains were recovered from a depth of 540-580 m (both cases) after 3 months (Namibia)/34 days (Sicily). In the Namibia case fully skeletonized bones were lifted. In the Sicily case a complete, dressed body was found exhibiting a partially skeletonized skull, starting adipocere formation and pink teeth. The rate and mode of decomposition of human bodies in the deep sea varies considerably and is mainly influenced by the local faunal composition. Of special relevance for the understanding of both cases was the oceanographic observation that the highly efficient necrophageous lyssianassids are abundant off Namibia but are rare in the Mediterranean, emphasizing the importance of collaboration of forensic and marine scientists in such case work.     

不同环境条件下大鼠死后皮肤生物力学特性改变

目的死亡时间的推测是法医病理学研究的重点和难点。皮肤具有一定生物力学特性,是机体死后分解破坏发生较迟的部分。本研究观察不同环境条件下死后大鼠皮肤生物力学特性的改变,探索其与死亡时间的关系。方法系统测试雌性SD大鼠在不同环境条件下（A组较高环境温度,B组较低环境温度）的死后皮肤生物力学特性。结果 A组大鼠皮肤死后张应力、延伸率在死后1d内先降低后升高,1d～6d逐渐降低,6d～7d略呈上升趋势;B组大鼠皮肤死后张应力在死后2d内先降低后升高,2d～16d逐渐降低,16d～20d略上升。结论 A组的张应力、延伸率和B组的张应力、应变能密度均表现出与死亡时间较好的相关性,是较好的推测死亡时间的生物力学参数。