Under-reporting of forensic findings: craniocervical emergency imaging in cases of survived hanging.

To determine the diagnostic bias between clinical and forensic radiology in cases of nonfatal hanging and determine and describe typical underreported imaging findings. In a retrospective, single-center study, all patients admitted for attempted suicide with near-hanging or fatal hanging between January 2008 and December 2020 who received CT or MRI of head and neck were reviewed and missed findings in the original report were documented. A binary regression with disagreement as dependent variable was fitted for the imaging modality, fatality, age, and sex. A total of 123 hanging incidents were retrospectively analyzed. The vast majority (n = 108; 87.8%) had attempted suicide with a nonfatal outcome. Fatal outcome occurred in 15 (12.0%). The extra- and intracranial injuries documented on CT and MRI scans were laryngeal (n = 8; 6.5%), soft tissue (n = 42; 34.1%), and vascular injuries (n = 1; 0.8%). Intracranial pathology was evident on 18 (14.6%) scans. Disagreement occurred in 36 (29.3%) cases and represented 52 (69.2%) of all cases with a radiological finding. Disagreement was strongly associated with fatality (OR: 2.7-44.9.4, p = 0.0012). In most cases, nonfatal hangings cause no or only minor injuries. Fatal cases are associated with a greater probability of missed minor imaging findings. This suggests that findings deemed clinically irrelevant are probably not reported in such severe emergency cases. This association indicates that minor abnormalities are underreported when major pathologies are evident on imaging in victims of strangulation.

U1 small nuclear RNA plays a direct role in the formation of a rev-regulated human immunodeficiency virus env mRNA that remains unspliced.

rev-regulated expression of HIV-1 envelope proteins from a simian virus 40 late replacement vector was found to be dependent on the presence of a 5' splice site in the env mRNA in spite of the fact that this mRNA remains unspliced. When the 5' splice site upstream of the env open reading frame was deleted or mutated, expression of envelope protein was lost. RNA analysis of cells transfected with 5' splice-site mutants showed a dramatic reduction in the steady-state levels of env mRNA whether or not rev was present. Envelope expression could be restored in one of the 5' splice-site mutants by cotransfection with a plasmid expressing a suppressor U1 small nuclear RNA containing a compensatory mutation. These experiments show that U1 small nuclear RNA plays a direct and essential role in the formation of an unspliced RNA that is subject to regulation by rev.

Regulation of human immunodeficiency virus env expression by the rev gene product.

A single simian virus 40 late replacement vector which expresses both the rev and envelope (env) genes of human immunodeficiency virus was used to examine the mechanism underlying the dependence of env gene expression on the rev protein. When rev was deleted from the vector, no envelope protein expression could be detected in transfected cells, and the levels of cytoplasmic env mRNA were dramatically reduced. In contrast to this, the levels of env RNA in total cellular RNA preparations were similar with or without rev coexpression, and analysis of nuclear RNA showed that the levels of nuclear env RNA were increased in the absence of rev. These results suggest that rev functions to regulate nuclear export of env mRNA. It was possible to restore env expression from the vector lacking rev by supplying rev in trans, provided that a cis-acting sequence was also present. This sequence was mapped to a 854-base-pair region within the env open reading frame, and it was shown that the sequence could be moved but that it worked only in its original orientation.