Biomedical subjects

Andrew M Baker

Publications and source records attributed to Andrew M Baker.

8 recordsLinked to original sources

PubMed2004

Medical examiners, coroners, and biologic terrorism: a guidebook for surveillance and case management.

Medical examiners and coroners (ME/Cs) are essential public health partners for terrorism preparedness and response. These medicolegal investigators support both public health and public safety functions and investigate deaths that are sudden, suspicious, violent, unattended, and unexplained. Medicolegal autopsies are essential for making organism-specific diagnoses in deaths caused by biologic terrorism. This report has been created to 1) help public health officials understand the role of ME/Cs in biologic terrorism surveillance and response efforts and 2) provide ME/Cs with the detailed information required to build capacity for biologic terrorism preparedness in a public health context. This report provides background information regarding biologic terrorism, possible biologic agents, and the consequent clinicopathologic diseases, autopsy procedures, and diagnostic tests as well as a description of biosafety risks and standards for autopsy precautions. ME/Cs' vital role in terrorism surveillance requires consistent standards for collecting, analyzing, and disseminating data. Familiarity with the operational, jurisdictional, and evidentiary concerns involving biologic terrorism-related death investigation is critical to both ME/Cs and public health authorities. Managing terrorism-associated fatalities can be expensive and can overwhelm the existing capacity of ME/Cs. This report describes federal resources for funding and reimbursement for ME/C preparedness and response activities and the limited support capacity of the federal Disaster Mortuary Operational Response Team. Standards for communication are critical in responding to any emergency situation. This report, which is a joint collaboration between CDC and the National Association of Medical Examiners (NAME), describes the relationship between ME/Cs and public health departments, emergency management agencies, emergency operations centers, and the Incident Command System.

Bioterrorism↗

PubMed2004

Mitochondrial DNA phylogenetic structuring suggests similarity between two morphologically plastic genera of Australian freshwater mussels (Unionoida: Hyriidae).

In the Lake Eyre Basin, the Australian hyriid genus Velesunio is represented by three undescribed species, each of which are highly divergent genetically, but morphologically similar to Velesunio wilsonii (Lea 1859). A fourth species, Velesunio ambiguus (Philippi 1847), occurs not only in the Lake Eyre Basin but throughout much of eastern Australia, including the Murray-Darling Basin. In this study, we show that another hyriid, Alathyria jacksoni (Iredale 1934), which is sympatric with V. ambiguus, is genetically deeply nested within the Velesunio species complex, such that the genus Velesunio is paraphyletic with respect to A. jacksoni. Moreover, our mitochondrial phylogenetic reconstructions indicate that A. jacksoni is closely allied to one of the cryptic Velesunio species occurring in the Lake Eyre Basin, but distinct from V. ambiguus and the two other Velesunio species. These data suggest that the genera Alathyria and Velesunio are in need of revision. The shells of A. jacksoni and Velesunio spp. vary with local conditions and sometimes are difficult to distinguish. Our analyses also show that shell characters of these taxa do not closely match the phylogenetic data, and it appears that the traditional taxonomic emphasis on these plastic characters has obscured evolutionary relationships between these, and possibly other, Hyriidae.

Animals↗

PubMed2004

Past and present patterns of connectivity among populations of four cryptic species of freshwater mussels Velesunio spp. (Hyriidae) in central Australia.

We examined genetic structure and levels of connectivity among subpopulations within each of four cryptic species belonging to the freshwater mussel genus Velesunio. We used allozymes and a fragment of the mitochondrial cytochrome c oxidase I gene to examine genetic variation in populations from isolated waterholes, belonging to four major inland drainages in eastern Australia. Based on evidence from other invertebrates in the region we predicted that, in each species, we would find evidence of historical connectivity among populations from different drainages. This was clearly not the case, as for the two species that occurred in more than one drainage there was evidence of both current and past restriction to gene flow. Moreover, given the potential for extensive dispersal of these mussels through the river systems during flood times via their fish hosts, we predicted low levels of genetic variation among populations from waterholes in the same drainage. Contrary to our expectations, all four species showed some evidence of restricted gene flow among waterholes within drainages. This suggests that either (a) mussel larvae are not produced during flood times, when their fish hosts would be free to move between waterholes, or (b) mussel larvae are attached to their hosts at these times, but the fish movement is limited between waterholes.

Analysis of Variance↗

PubMed2003

Homicidal commotio cordis: the final blow in a battered infant.

OBJECTIVE: This report describes in detail the occurrence of inflicted commotio cordis (cardiac concussion) in a previously abused 7-week-old. Though inflicted commotio cordis has been reported in three toddlers, this is the first report in a young infant. METHOD: Following documentation of abuse in a living child, the case of a death of a prior sibling--previously regarded as natural--was re-opened for further investigation. Original autopsy materials were reviewed, and the body of the deceased child was exhumed. RESULTS: Exhumation and second autopsy documented more than 50 fractures in the deceased child. When re-interviewed, the children's father admitted to causing the injuries in both children, and gave a textbook description of commotio cordis as the mechanism of death in the fatal case. CONCLUSIONS: Commotio cordis is a rare event in which a fatal dysrhythmia--usually ventricular fibrillation--is precipitated by a blow to the precordial chest. Previous reports have indicated that homicidal commotio cordis can occur in small children. This report demonstrates that commotio cordis can occur even in the very young, previously abused infant.

Autopsy↗

PubMed2003

Cryptic species and morphological plasticity in long-lived bivalves (Unionoida: Hyriidae) from inland Australia.

Molecular (mitochondrial DNA, isozyme) and morphological diversity of freshwater mussels (Family Hyriidae) was examined at 21 sites encompassing four large river systems, across southwest Queensland, Australia. Evidence was found for two major morphological groups. One group, which occurred in every river system, closely matched a recognized species (Velesunio ambiguus) both morphologically and in a well-supported lineage within a mitochondrial phylogeny generated from partial cytochrome c oxidase subunit I (COI) sequences. The second group most closely matched Velesunio wilsonii in shell morphology but formed three deeply divergent mitochondrial DNA lineages. All four lineages occurred sympatrically in some areas and displayed corresponding fixed differences at nuclear allozyme loci, which suggests an absence of recent hybridization and the presence of separate species.

Animals↗

PubMed2003

Fatal diphenhydramine intoxication in infants.

Diphenhydramine is an antihistamine available in numerous over-the-counter preparations. Often used for its sedative effects in adults, it can cause paradoxical central nervous system stimulation in children, with effects ranging from excitation to seizures and death. Reports of fatal intoxications in young children are rare. We present five cases of fatal intoxication in infants 6, 8, 9, 12, and 12 weeks old. Postmortem blood diphenhydramine levels in the cases were 1.6, 1.5, 1.6, 1.1 and 1.1 mg/L, respectively. Anatomic findings in each case were normal. In one case the child's father admitted giving the infant diphenhydramine in an attempt to induce the infant to sleep; in another case, a daycare provider admitted putting diphenhydramine in a baby bottle. Two cases remain unsolved; one case remains under investigation. The postmortem drug levels in these cases are lower than seen in adult fatalities. We review the literature on diphenhydramine toxicity, particularly as it pertains to small children, and discuss the rationale for treating these cases as fatal intoxications.

Diphenhydramine↗

PubMed2002

Estimation of body exposure to explosion.

An ordnance-disposal expert was killed while disposing of a cache of explosives. The likely position of the body was reconstructed by modeling the explosion as an omnidirectional emission of particles from a model of the explosion site and noting the distribution of particles on a model of a human. The applications and limitations of this method in reconstructing the events and correlation with the injuries noted at autopsy are discussed.

Accidents, Occupational↗

PubMedDate not supplied

From the archives of the AFIP. Child abuse: radiologic-pathologic correlation.

In the United States, roughly one of every 100 children is subjected to some form of neglect or abuse; inflicted injury is responsible for approximately 1,200 deaths per year. Child physical abuse may manifest as virtually any injury pattern known to medicine. Some of the injuries observed in battered children are relatively unique to this population (especially when observed in infants) and therefore are highly suggestive of nonaccidental, or inflicted, injury. Worrisome injuries include rib fracture, metaphyseal fracture, interhemispheric extraaxial hemorrhage, shear-type brain injury, vertebral compression fracture, and small bowel hematoma and laceration. As noted, however, virtually any injury may be inflicted; therefore, careful consideration of the nature of the injury, the developmental capabilities of the child, and the given history are crucial to determine the likelihood that an injury was inflicted. The majority of these injuries are readily detectable at imaging, and radiologic examination forms the mainstay of evaluation of child physical abuse. Detection of metaphyseal fracture (regarded as the most specific radiographically detectable injury in abuse) depends on high-quality, small field-of-view radiographs. The injury manifests radiographically as a lucent area within the subphyseal metaphysis, extending completely or partially across the metaphysis, roughly perpendicular to the long axis of the bone. Acute rib fractures (which in infants are strongly correlated with abuse) appear as linear lucent areas. They may be difficult to discern when acute; thus, follow-up radiography increases detection of these fractures. For skull injuries, radiography is best for detecting fractures, but computed tomography and magnetic resonance imaging best depict intracranial injury.

Archives↗