Nodding syndrome phenotypes.

Nodding syndrome (NS) is a progressive encephalopathy of children and adolescents characterized by seizures, including periodic vertical head nodding. Epidemic NS, which has affected parts of East Africa, appears to have clinical overlap with sub-Saharan Nakalanga syndrome (NLS), a brain disorder associated with pituitary dwarfism that appears to have a patchy distribution across sub-Sahara. Clinical stages of NS include inattention and blank stares, vertical head nodding, convulsive seizures, multiple impairments, and severe cognitive and motorsystem disability, including features suggesting parkinsonism. Head nodding episodes occur in clusters with an electrographic correlate of diffuse high-amplitude slow waves followed by an electrodecremental pattern with superimposed diffuse fast activity. Brain imaging reveals differing degrees of cerebral cortical and cerebellar atrophy. Brains of NS-affected children with mild frontotemporal cortical atrophy display neurofibrillary pathology and dystrophic neurites immunopositive for tau, consistent with a progressive neurodegenerative disorder. The etiology of NS and NLS appears to be dominated by environmental factors, including malnutrition, displacement, and nematode infection, but the specific cause is unknown.

The Rise of Forensic Pathology in Human Medicine: Lessons for Veterinary Forensic Pathology.

The rise of forensic pathology in human medicine has greatly contributed to the administration of justice, public safety and security, and medical knowledge. However, the evolution of human forensic pathology has been challenging. Veterinary forensic pathologists can learn from some of the lessons that have informed the growth and development of human forensic pathology. Three main observations have emerged in the past decade. First, wrongful convictions tell us to use a truth-seeking stance rather than an a priori "think dirty" stance when investigating obscure death. Second, missed homicides and concealed homicides tell us that training and certification are the beginning of reliable forensic pathology. Third, failure of a sustainable institutional arrangement that fosters a combination of service, research, and teaching will lead to stagnation of knowledge. Forensic pathology of humans and animals will flourish, help protect society, and support justice if we embrace a modern biomedical scientific model for our practice. We must build training programs, contribute to the published literature, and forge strong collaborative institutions.

Effects of tacrolimus on an organotypic raft-culture model mimicking oral mucosa.

BACKGROUND: Tacrolimus ointment has shown efficacy in treating T-cell-mediated inflammatory oral mucosal diseases, including lichen planus. However, the safety of topical tacrolimus has been questioned, based on its possible association with malignant transformation. AIM: To evaluate the safety aspects of tacrolimus in a three-dimensional in vitro model of oral mucosa containing both multilayered epithelium and connective tissue (raft culture). METHODS: Raft cultures mimicking oral mucosa were topically exposed to tacrolimus, and the effects on cell proliferation and adhesion, epidermal growth factor receptors (EGFR, ERBB2, ERBB3, ERBB4), and apoptosis were evaluated with immunohistochemistry and terminal dUTP nick-end labelling, respectively. Results. The epithelium of the cultures was found to be slightly thinner, but no changes in cell proliferation or adhesion, apoptosis, or expression of epidermal growth factor receptors were detected. CONCLUSIONS: Our results suggest that short-term topical tacrolimus exposure of in vitro constructed oral mucosa does not induce changes in a number of factors known to be involved in malignant transformation.

Host-bacteria crosstalk at the dentogingival junction.

The dentogingival junction is of crucial importance in periodontal host defense both structurally and functionally. Oral bacteria exert a constant challenge to the host cells and tissues at the dentogingival junction. The host response is set up to eliminate the pathogens by the innate and adaptive defense mechanisms. In health, the commensal bacteria and the host defense mechanisms are in a dynamic steady state. During periodontal disease progression, the dental bacterial plaque, junctional epithelium (JE), inflammatory cells, connective tissue, and bone all go through a series of changes. The tissue homeostasis is turned into tissue destruction and progression of periodontitis. The classical study of Slots showed that in the bacterial plaque, the most remarkable change is the shift from gram-positive aerobic and facultatively anaerobic flora to a predominantly gram-negative and anaerobic flora. This has been later confirmed by several other studies. Furthermore, not only the shift of the bacterial flora to a more pathogenic one, but also bacterial growth as a biofilm on the tooth surface, allows the bacteria to communicate with each other and exert their virulence aimed at favoring their growth. This paper focuses on host-bacteria crosstalk at the dentogingival junction and the models studying it in vitro.

Fatal hemorrhage following trans--sphenoidal resection of a pituitary adenoma: a case report and review of the literature.

A 58-year-old woman with acromegaly developed massive epistaxis 7 days following trans-sphenoidal resection of a growth hormone-secreting pituitary adenoma. At autopsy, it was determined that the source of the hemorrhage was a rupture of the intracavernous segment of the internal carotid artery secondary to a bacterial arteritis. We describe the gross dissection and histologic examination undertaken in this unusual case, discuss the possible etiology of the infection and review the potential complications of this surgical approach with a view to improving forensic examination of these patients.

Determination of safety levels of horseradish peroxidase-iodide system to human gingival keratinocytes and fibroblasts in vitro.

The peroxidase-iodide (I-) system is a potential antimicrobial agent, and its bacteriocidal activity against various periodontal bacteria has been shown in many studies. The aim of this study was to investigate the possible cytotoxic effects of a non-physiological horseradish peroxidase (HRP)-I- system on human gingival keratinocytes and fibroblasts. Immortalized human skin keratinocyte cell line was used as a reference. Three indicators were studied: membrane permeability (trypan blue staining), cell growth (crystal violet staining) and metabolic activity (alamarBlue stain). The cells were cultured in microtitration plates, and the most commonly used exposure time to the HRP system was 1 h. The effects of HRP system on cell growth and metabolic activity were observed at lower I- and H2O2 concentrations than its effects on membrane permeability. Gingival fibroblasts were more prone to detachment than keratinocyte cell lines, but no differences in changes of growth or metabolic activities were observed between gingival fibroblasts and gingival keratinocytes. The highest concentrations of the HRP-I- system components which did not have any significant detrimental effects on the metabolic activity and cell growth of gingival keratinocytes and fibroblasts were: 50 microg/ml HRP, 500 micromol/L I- and 500 micromol/L H2O2. Although this system has been shown to be antibacterial against oral bacteria, no recommendations about the usage of the HRP-I- system in oral cavity can be made yet due to the in vitro nature of this study. Our results form the basis for future safety studies investigating the chronic toxicity of this system to oral epithelium.

Death due to bioterrorism-related inhalational anthrax: report of 2 patients.

On October 9, 2001, a letter containing anthrax spores was mailed from New Jersey to Washington, DC. The letter was processed at a major postal facility in Washington, DC, and opened in the Senate's Hart Office Building on October 15. Between October 19 and October 26, there were 5 cases of inhalational anthrax among postal workers who were employed at that major facility or who handled bulk mail originating from that facility. The cases of 2 postal workers who died of inhalational anthrax are reported here. Both patients had nonspecific prodromal illnesses. One patient developed predominantly gastrointestinal symptoms, including nausea, vomiting, and abdominal pain. The other patient had a "flulike" illness associated with myalgias and malaise. Both patients ultimately developed dyspnea, retrosternal chest pressure, and respiratory failure requiring mechanical ventilation. Leukocytosis and hemoconcentration were noted in both cases prior to death. Both patients had evidence of mediastinitis and extensive pulmonary infiltrates late in their course of illness. The durations of illness were 7 days and 5 days from onset of symptoms to death; both patients died within 24 hours of hospitalization. Without a clinician's high index of suspicion, the diagnosis of inhalational anthrax is difficult during nonspecific prodromal illness. Clinicians have an urgent need for prompt communication of vital epidemiologic information that could focus their diagnostic evaluation. Rapid diagnostic assays to distinguish more common infectious processes from agents of bioterrorism also could improve management strategies.

Subtle fatal manual neck compression.

A critical analysis of the postmortem diagnostic criteria for asphyxia leads to a difficulty that has significant implications for the forensic pathologist. The difficulty is that there are no universally recognized pathognomic signs of asphyxia, but pathologists frequently make this diagnosis based on observations that individually have indeterminate significance but combined together, in the appropriate context, have diagnostic value. This leads to the question: if asphyxia has no recognizable signs at autopsy how are we able to diagnose this entity in the latter circumstances? This problem can be solved by defining the minimally adequate diagnostic criteria for compressive neck injury. These criteria are potentially well-defined but currently lacking, in part, due to incomplete morphological characterization of the injuries that frequently occur in strangulation. The problem is especially challenging because the signs of strangulation form a spectrum of degree from minimal to marked and there is no consensus as to the minimal number and nature of lesions that is required to make the diagnosis of strangulation. In the present review of lesions that are commonly encountered in strangulation, intracartilaginous laryngeal haemorrhages and laryngeal cartilage microfractures are considered to have unrecognized diagnostic value, and these lesions are described in detail. A triad of haemorrhages (subepithelial laryngeal haemorrhage, intralaryngeal muscular haemorrhage, and intracartilaginous laryngeal haemorrhage) is discussed in the context of developing a definition of strangulation based on morphological criteria in the absence of overt mechanical injuries to the neck. Although definitive criteria for cases with minimal findings are still lacking, several lesions have putative diagnostic value.

Limbs found in water: investigation using anthropological analysis and the diatom test.

We report the investigation, using a multi-disciplinary approach, of five cases of dismembered limbs which were recovered from Lake Ontario, Lake Erie and the Niagara River, and examined at the Office of the Chief Coroner for Ontario. In all cases, postmortem examination revealed that the limbs had been disarticulated in the postmortem period, by non-human taphonomic processes. In addition to routine gross examination, the femur and/or tibia were assessed using anthropological methods to give estimates of the sex, age, race and stature of the individual. The anthropologic data facilitated the identification of one of the cases. In all cases, nitric acid extracts of the femoral bone marrow were prepared and examined for the presence of diatoms. In all instances, diatom frustules were recovered from marrow extracts, indicating that drowning was the cause of death or at least a significant contributing factor in the cause of death. The use of the diatom test was helpful in excluding the possibility that the limbs were dismembered from individuals who had died by means other than drowning, and had been subsequently 'dumped' into water. The application of anthropological methods and the diatom test for drowning may significantly enhance the medico-legal investigation of body parts recovered from water, and we present an overview of useful techniques here. Anthropological data may facilitate identification, and the diatom test may establish a cause of death.

A triad of laryngeal hemorrhages in strangulation: a report of eight cases.

The results of histological studies on larynges from eight cases of manual strangulation, all that had intracartilaginous laryngeal hemorrhages, a recently described and under-recognized lesion associated with strangulation, are reported. Formalin-fixed larynges were examined in serial section using a standardized protocol. In all cases, intracartilaginous laryngeal hemorrhages were associated with subepithelial laryngeal hemorrhages, and intralaryngeal muscular hemorrhages forming a "triad of hemorrhages." In five cases, the triad was found in the presence of laryngeal cartilage microfractures. Since cartilage microfractures can be causally related to mechanical injury to the neck, it is likely that the triad of hemorrhages has diagnostic value as an independent morphological criterion for the postmortem diagnosis of strangulation. Since a proportion of cases of strangulation lack characteristics that are self-evidently due to violent application of pressure on the neck, recognition of the triad may have important implications for the postmortem diagnosis of strangulation.

Modeling of a periodic instability in paired helical filaments reveals an axial repeat.

Ultrastructural studies of paired helical filaments (PHF) have been facilitated by the ability to isolate enriched fractions of detergent-insoluble forms of PHF. These fractions are composed of a relatively homogeneous population of short (usually < 400 nm) highly fragmented PHF. A small proportion of isolated PHF have highly stereotyped angled profiles that represent deformations due to structural instability. These distorted PHF can be characterized quantitatively using a simple numerical procedure that reveals that the axial instabilities occur with predictable regularity over the length of the PHF. Using a structural model of PHF, it is shown that the periodicity of the axial instability can be correlated to an axially repeated subunit of uniform size. The upper limit for the axial extent of the repeated segment was calculated to be 80 nm, similar to the size of a single one-half twist in the PHF ribbon. It is proposed that this segment may represent one type of particle in the hierarchy of structural subunits in the PHF ribbon, or an oligomeric intermediate species in PHF assembly.

Epithelial cell response to challenge of bacterial lipoteichoic acids and lipopolysaccharides in vitro.

Accumulating dental plaque at the gingival margin contains lipoteichoic acids (LTAs) from the cell walls of gram-positive bacteria. In subgingival plaque associated with periodontal disease the amount of lipopolysaccharides (LPSs) from gram-negative bacteria increases. As the gingival junctional epithelium (JE) is an important structural and functional tissue, participating in the first line defence against apical advancement of dental plaque, this study examined the direct effects of LTAs (from Streptococcus mutans and S. sanguis) and LPSs (from Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola and Escherichia coli) on two epithelial cell lines (HaCaT and ERM) and a culture model for human JE. The cells were exposed to the LTAs or LPSs (10-50 microg/ml) for variable periods of time. None of the bacterial surface components had any effect on primary adhesion or on the epithelial attachment of the JE cultures. However, cell growth and mitotic activity were consistently reduced in all cultures treated with LTAs. In contrast, LPSs showed only slight or no effects on cell growth and mitotic activity depending on the epithelial cells used. This suggests that LPSs, despite their established role as modulators of inflammation, do not have direct harmful effects - at the concentrations found in dental plaque and gingival crevicular fluid - which would explain the mechanism of epithelial degeneration and detachment from the tooth surface. However, the LTAs appear to inhibit the renewal of epithelium and may thus contribute to degeneration of coronal JE and subgingival colonisation by periodontal pathogens.

Effect of short chain fatty acids on human gingival epithelial cell keratins in vitro.

Hemidesmosomal attachment of the junctional epithelial cells to the tooth and the ability of the attached cells to divide are essential features of the healthy dentogingival junction. Short chain fatty acids are bacterial metabolites associated with gingival inflammation and periodontal pockets. In vitro, short chain fatty acids have been shown to inhibit epithelial cell division and increase the density of their keratin filaments. This study examined these keratin changes by making use of human gingival keratinocyte cultures, gel electrophoresis and Western blot. Short chain fatty acids, butyrate and propionate, increased the relative amount of keratin proteins in the cells, most strikingly keratin K17. The distribution of K17 was further studied in a culture model for human junctional epithelium and in gingival biopsies. In butyrate-treated cultures of junctional epithelium, K17 expression was markedly increased and extended to the basal cells and to the cells mediating the attachment of the explant to the substratum. In clinically healthy gingiva, K17 was expressed predominantly in sulcular epithelium. The dividing basal cells and the cells attached to the tooth were negative. In advanced periodontitis, a strong reaction for K17 was localised to the pocket epithelium. The inhibition of epithelial cell division and the simultaneous upregulation of K17 in vitro, and the strong expression of this protein in detached pocket epithelium suggest a role for the short chain fatty acids in the degenerative process that leads to subgingival advancement of pathogens and, eventually, to periodontal pocket formation.

Unexpected death related to restraint for excited delirium: a retrospective study of deaths in police custody and in the community.

BACKGROUND: Some people in states of excited delirium die while in police custody. Emerging evidence suggests that physical restraint in certain positions may contribute to such deaths. In this study the authors determined the frequency of physical restraint among people in a state of excited delirium who died unexpectedly. METHODS: The authors reviewed the records of 21 cases of unexpected death in people with excited delirium, which were investigated by the Office of the Chief Coroner for Ontario between 1988 and 1995. Eyewitness testimony, findings during postmortem examinations, clinical history, toxicological data and other official documents describing the events surrounding the deaths were analyzed. Specific reference was made to documented eyewitness testimony of restraint method, body position and use of capsicum oleoresin (pepper) spray. Because cocaine was detected in the blood of some of these people during the postmortem examination, the role of cocaine in excited delirium was examined by comparing the cocaine levels in these cases with levels in 2 control groups: 19 people who died from acute cocaine intoxication and 21 people who had used cocaine shortly before they died but who had died from other causes. RESULTS: In all 21 cases of unexpected death associated with excited delirium, the deaths were associated with restraint (for violent agitation and hyperactivity), with the person either in a prone position (18 people [86%]) or subjected to pressure on the neck (3 [14%]). All of those who died had suddenly lapsed into tranquillity shortly after being restrained. The excited delirium was caused by a psychiatric disorder in 12 people (57%) and by cocaine-induced psychosis in 8 (38%). Eighteen people (86%) were in police custody when they died. Four (19%) had been sprayed with capsicum oleoresin, and heart disease was found in another 4 at autopsy. The blood level of cocaine in those whose excited delirium was cocaine induced was similar to levels found in recreational cocaine users and lower than levels found in people who died from cocaine intoxication. INTERPRETATION: Restraint may contribute to the death of people in states of excited delirium, and further studies to test this hypothesis are recommended. Meanwhile, law enforcement authorities and others should bear in mind the potential for the unexpected death of people in states of excited delirium who are restrained in the prone position or with a neck hold.

Intra-cartilaginous laryngeal haemorrhages and strangulation.

A previously unrecognized laryngeal injury in young female victims of manual strangulation is described. Twelve larynges that were retrospectively and prospectively collected at the Office of the Chief Coroner for Ontario (1982-1997) were used for this study. In all instances, the larynges were from cases of strangulation (mean age 27 +/- 10 years, range 20-46) with classical postmortem findings of asphyxia and either manual or combined manual and ligature strangulation. None of the larynges had fractures of the lamina of the thyroid cartilage, superior cornua, or cricoid cartilages. However, in 9 of the 12 cases (75%), sagittal sections revealed multifocal acute haemorrhages into the base of the superior cornua of the thyroid cartilage at the point of origin from the laminae. The presence of acute intra-cartilaginous haemorrhage into the larynx likely represents the disruption of small blood vessels due to elastic deformation of the flexible larynx during strangulation. The recognition of this form of laryngeal injuries broadens the pathological findings in cases of asphyxia associated with pressure on the neck.

Lactoferrin impedes epithelial cell adhesion in vitro.

In the process of host defence against microbial challenge, neutrophils release granule contents with the potential side effect of damaging structural tissues. In the junctional epithelium such damage may contribute to the degeneration and renewal of the epithelial cells attached directly to the tooth (DAT cells), and subsequently to periodontal pocket formation. This study reports on lactoferrin, one of the substances released by neutrophils, and its effects on epithelial cell adhesion, growth, DNA synthesis and spreading of cell colonies at concentrations recorded in the crevicular fluid. We show that, in opposition to what has been reported on bacterial cells, lactoferrin has no effect on the DNA synthesis of attached epithelial cells in model systems attempting to simulate the DAT cells in vivo. However, both iron-saturated and unsaturated lactoferrin hampered cell adhesion, growth and spreading of cell colonies in a dose-dependent manner. These findings suggest that lactoferrin does not affect epithelial cell proliferation but it may have a role in delaying the repair of the DAT cell population during inflammation by interfering with cell adhesion.

Diatoms and homicide.

Six illustrative cases of homicidal drowning are reported in which the diatom test for drowning was a useful adjunct to the medicolegal investigation of death. In all six cases, diatom frustules were recovered from the femoral bone marrow. In five cases, diatoms extracted from the bone marrow were compared with diatoms obtained from samples of putative drowning medium. In all of these case, the same types of diatoms were observed in both the water samples and the marrow. In an additional case, watery fluid from the maxillary sinus contained the same diatom types as were present in the femoral bone marrow. Four of the six cases were found submerged in water and had autopsy findings consistent with drowning. In the remaining two cases, the bodies were found on land; one case was grossly decomposed and one body was extensively burned since the body was set afire on dry land after death. In some of the case drowning was associated with blunt force head injury (one case), sharp force injuries of the chest (one case), or strangulation (three cases). These results indicate that the diatom test for drowning is an important adjunct to the medicolegal investigation of homicidal drowning, particularly in those cases were autopsy and scene findings do not imply drowning as a cause of death.

Forensic significance of the polymorphism of hyoid bone shape.

The reasons why some hyoids fracture in strangulation and others do not may relate to anatomic features of the hyoid bone. On this basis, we studied the dimensions and shape of hyoid bones (n = 100) originating from the Terry collection, National Museum of Natural History, Smithsonian Institution. The hyoid bones were extensively polymorphic in both dimensions studied, the span or breadth, and the length of the cornua. There was no linear relationship between the breadth and length dimensions of the bone. Based on qualitative assessment, hyoid bones could be classed as either hyperbolic (55%) or parabolic (45%) in shape. Hyperbolic hyoid bones could be distinguished from hyoid bones with a parabolic configuration on the basis of the metric data although there was considerable overlap in the dimensions of hyoid bones of both configurations. Female hyoid bones tended to be smaller in both dimensions than male hyoid bones. The metric parameters of fractured hyoid bones from 10 cases (8 female, 2 male) of strangulation were compared with the dimensions of hyoid bones in this study. The metric features of the fractured hyoid bones were attributable to the predominance of females in the group of fractured hyoid bones studied, an observation that is anticipated because the majority of strangulations involve female decedents. On this basis, we conclude that variables other than the shape and dimensions of the hyoid bone are more relevant in determining if hyoid fracture occurs during strangulation.

Cortical degeneration in progressive supranuclear palsy. A comparison with cortical-basal ganglionic degeneration.

We report 3 patients with progressive supranuclear palsy (PSP) who developed limb apraxia, focal dystonia, and arm levitation late in the course of the disease. Neuropathological examination revealed cortical degeneration in addition to the characteristic pathological findings of PSP. Semiquantitative comparative histological and immunohistological studies of the neocortex of these patients as well as 5 cases of classical PSP and 4 cases of cortical-basal ganglionic degeneration (CBGD) revealed a distinctive form of cortical degeneration in PSP. The cortical degeneration was often circumscribed and confined to premotor and motor cortex. It was characterized by neuronal loss and gliosis. Swollen neurons were only rarely observed in neocortex of PSP cases in contrast with CBGD, where they were abundant. Neuronal and glial tau as well as tau immunoreactive threads were seen in both PSP and CBGD, but were more abundant in CBGD. The appearance of tau reactive astrocytes also differed in both disorders; tufted astrocytes were seen exclusively in PSP, while typical annular astrocytic plaques were confined to CBGD. These observations indicate that cortical degeneration occurs in PSP and may be associated with atypical clinical manifestations that lead to diagnostic difficulties.