Mitochondrial DNA sequencing of beetle larvae (Nitidulidae: Omosita) recovered from human bone

The isolation, amplification, and characterization of human DNA from hematophagous (blood feeding) and necrophagous (carrion feeding) arthropods have been advanced significantly by the development of polymerase chain reaction (PCR) DNA sequencing methodologies. Historically, DNA technology has been successfully utilized to identify individual hosts upon which species of hematophagous arthropods have fed. The analysis of hematophagous insects' gut content blood meals has led to major advances in medical entomology and vector-borne disease epidemiology. In the forensic arena, the ability to apply similar techniques to insects recovered from badly decomposed remains has been greatly enhanced through the advent of mitochondrial DNA (mtDNA) techniques. Mitochondrial DNA analyses have been utilized to identify both the human remains upon which fly larvae (maggots) have fed and the species of the larvae themselves. The preliminary work detailed here demonstrates, for the first time, the successful application of mtDNA sequencing techniques to the analysis of necrophagous beetle larvae. A small sample of sap beetle larvae, Omosita spp. (Coleoptera: Nitidulidae), was collected from human skeletal remains during anthropological examination and analyzed for human DNA using mtDNA sequencing. The beetle larvae yielded mtDNA matching that of the host human bone. The results detailed here further demonstrate the robust nature of human mtDNA and the ability to recover valuable mtDNA evidence from forensically important, late decompositional stage insect species.     

Detection of a primer-binding site polymorphism for the STR locus D16S539 using the Powerplex 1.1 system and validation of a degenerate primer to correct for the polymorphism

Quality assurance samples submitted from the NCSBI as part of a contract with TBTG to outsource DNA Database samples showed unexpected discrepancies for the locus D16S539 when all other loci yielded identical results. Discrepancies observed included allele drop out and an imbalance in sister alleles with samples returned from TBTG. This led to a comprehensive review of the technical procedures used between the two laboratories to determine the cause of the discrepancies noted for the locus D16S539, since both laboratories were using the PowerPlex 1.1 typing kit from the Promega Corporation. The NCSBI and the TBTG utilize different extraction methods (organic extraction vs. FTA) and amplification conditions (AmpliTaq vs AmpliTaq Gold), respectively, so the exact cause of discrepancy observed was not immediately apparent. Experiments at the NCSBI associated the observed allele drop out and the imbalance of the sister alleles with the use of AmpliTaq Gold and a hot start procedure. Sequencing data revealed that a point mutation resides on the D16S539 primer-binding site that reaches polymorphic levels in African-American populations. This led to the development of a degenerate primer by the Promega Corporation to detect "missing" alleles when AmpliTaq Gold is used. The degenerate primer was then thoroughly tested to show its efficacy in detecting the "true" D16S539 profile when used.     

Forensic comparison of soils by bacterial community DNA profiling

This preliminary investigation has shown that a soil microbial community DNA profile can be obtained from the small sample of soil recovered from the sole of a shoe, and from soil stains on clothing. We have also shown that these profiles are representative of the site of collection and therefore could potentially be used as associative evidence to prove a link between suspects and crime scenes. Soil community profiles were obtained using the T-RFLP fingerprinting method that uses fluorescent primer technology and semi-automated analysis techniques similar to those used in human DNA profiling in forensic laboratories.     

Policy feedback and public opinion: the role of employer responsibility in social policy

This study extends the literature on policy feedback and explores the extent to which public attitudes reflect learning from past government initiatives. We analyze the ways in which feedback mechanisms affecting public attitudes may differ from those earlier identified in the literature. We apply this general analytic framework to help explain variation in public attitudes toward private employer involvement in health care, explore possible causal pathways, and offer some preliminary empirical tests of these hypotheses. There are different levels of public support for the notion of employer obligation involving medical care, long-term care, and the treatment of substance abuse. Our evidence suggests that lessons about the performance of institutions in each of these policy domains represent the most important effect of existing policy on public attitudes. Furthermore, these differences correspond to what one would expect based on our model of policy feedback and cannot be explained by other plausible sources of policy legitimacy.     

Autopsy confirmation of severe pulmonary interstitial fibrosis secondary to Munchausen syndrome presenting as cystic fibrosis

Chronic factitious disorder with physical symptoms, or Munchausen syndrome, is a well-recognized but uncommonly diagnosed psychiatric condition characterized by the deliberate production of signs and symptoms of disease in order to receive medical attention. Clinical suspicion of this disease is rarely confirmed by autopsy, as the patients usually do not die as a consequence of feigning illness. Here we report the autopsy confirmation of a case of a suspected Munchausen syndrome patient who presented with a history of cystic fibrosis. Examination of the lungs demonstrated extensive severe interstitial fibrosis, and polariscopic examination revealed a large quantity of crystalline material throughout the tissue; X-ray diffraction identified the material as talc. Synopses of published cases of Munchausen syndrome presenting as cystic fibrosis, and cases of Munchausen syndrome with pulmonary talcosis are presented as part of the discussion.