BackgroundThe infrarenal abdominal aorta exhibits increased disease susceptibility relative to other aortic regions. Allograft studies exchanging thoracic and abdominal segments showed that regional susceptibility is maintained regardless of location, suggesting substantial roles for embryological origin, tissue composition and site-specific gene expression.ResultsWe analyzed gene expression with microarrays in baboon aortas, and found that members of the HOX gene family exhibited spatial expression differences. HOXA4 was chosen for further study, since it had decreased expression in the abdominal compared to the thoracic aorta. Western blot analysis from 24 human aortas demonstrated significantly higher HOXA4 protein levels in thoracic compared to abdominal tissues (P < 0.001). Immunohistochemical staining for HOXA4 showed nuclear and perinuclear staining in endothelial and smooth muscle cells in aorta. The HOXA4 transcript levels were significantly decreased in human abdominal aortic aneurysms (AAAs) compared to age-matched non-aneurysmal controls (P < 0.00004). Cultured human aortic endothelial and smooth muscle cells stimulated with INF-γ (an important inflammatory cytokine in AAA pathogenesis) showed decreased levels of HOXA4 protein (P < 0.0007).ConclusionsOur results demonstrated spatial variation in expression of HOXA4 in human aortas that persisted into adulthood and that downregulation of HOXA4 expression was associated with AAAs, an important aortic disease of the ageing population.

Archery has experienced a recent resurgence in participation and has seen increases in archery range attendance and in children and young adults seeking archery lessons. Popular literature and movies prominently feature protagonists well versed in this form of weaponry. Periodic homicide cases in the United States involving bows are reported, and despite this and the current interest in the field, there are no manuscripts published on a large series of arrow wounds. This experiment utilizes a broad selection of modern arrowheads to create wounds for comparison. While general appearances mimicked the arrowhead shape, details such as the presence of abrasions were greatly influenced by the design of the arrowhead tip. Additionally, in the absence of projectiles or available history, arrowhead injuries can mimic other instruments causing penetrating wounds. A published resource on arrowhead injuries would allow differentiation of causes of injury by forensic scientists.

Asthma is a common disease in the United States and is frequently encountered during medicolegal autopsies. Patients are often young and have a witnessed collapse or are found dead. Opiate abuse is also pervasive and is repeatedly seen in death investigations. All cases over a 7-year period involving asthma investigated at the Wayne County Medical Examiner's Office were reviewed for demographics, circumstances, autopsy toxicology findings, and cause and manner of death. Ninety-four cases met these criteria. Ten cases (10.5%) were positive for opiates, 8 listed drugs as the cause of death, and 2 listed asthma. Of cases with established asthma opiate positivity, 8 (80%) were found dead, and only one had a witnessed collapse. Compared with those without opiate abuse, asthmatic patients abusing opiates had a higher mean age, no reported respiratory symptoms immediately preceding death, and higher frequency of being found dead. A discernable difference exists between deaths in asthmatic patients in the presence of opiates and those without. These findings indicate that it may be possible to predict the presence of opiates given history investigation information, thereby focusing toxicology panels to promote cost-effective practices when ordering supportive tests.

Celebratory use of fireworks has been an integral part of human civilization for over millennia. While the majority of firework use is festive, their explosive nature can result in traumatic injuries and death. The authors present the death of a 21-year-old man found unresponsive on the floor of his parent's garage with extensive damage to his head after an explosion was heard. Firearms could not be found, but there were unexploded homemade and commercially produced firecrackers and components for the manufacture of additional firecrackers. The radial expansion of the blast wave formed by the intraoral explosion of a firecracker created injuries matching those of an intraoral shotgun wound.