Coronary artery luminal narrowing in the young with sudden unexpected death: a coroner's autopsy study in 350 subjects age 40 years and under.

OBJECTIVE: To describe the extent and distribution of coronary artery luminal narrowing in a Canadian population (aged 40 years and under) dying suddenly and unexpectedly. METHODS: From a coroner's autopsy population of 350 subjects whose mean age was 28.4 +/- 6.5 years and of whom 250 were male, percentage luminal narrowing was estimated in the four epicardial coronaries. The left main, left anterior descending, left circumflex and right major coronary arteries were sectioned at 5 mm intervals and percentage cross-sectional luminal narrowing from the internal elastic lamina of each segment was estimated microscopically and then graded into four categories: I, 0 to 25%; II, 26 to 50%; III, 51 to 75%; and IV, greater than 75%. A total of 14,611 5 mm segments were evaluated (mean 41.7 per case). The segments were classified as originating from males or females and into three age groups (less than 20, 20 to 29 and 30 to 40 years). RESULTS: For the entire population, virtually no luminal narrowing greater than 50% was found in patients less than age 20 years, but was found in 3% of segments in the group aged 20 to 29 years and in 8.4% of segments in the group aged 30 to 40 years. In the group aged 20 to 29 years, greater than 50% narrowing was found in 3.8% of segments in males and in 1.2% of segments in females (P < 0.001). In the group aged 30 to 40 years, the corresponding numbers were 10.5% for males and 2.2% in females (P < 0.0001). Eighty-six males (34.4%) had greater than 50% narrowing of at least one coronary artery versus 19 females (19%) (P < 0.01). Left main narrowing of greater than 50% was found in 17 subjects, of which 13 were males. Luminal narrowing was more prevalent in the left anterior descending than the right coronary artery or left circumflex coronary artery and more prevalent in the right coronary artery than the left circumflex coronary artery. CONCLUSIONS: In subjects less than age 20 years, luminal narrowing greater than 50% was virtually nonexistent. Its frequency progressed in both sexes after age 20 years and was significantly more pronounced in males. Narrowing of the left main coronary artery was more frequent than anticipated and was more common in males.

Determination of human immunodeficiency virus antibody status in forensic autopsy cases in Vancouver using a recombinant immunoblot assay.

Sera from 207 forensic autopsy cases were tested for the presence of antibody to the human immunodeficiency virus (HIV) using a recombinant immunoblot assay (RIBA) technique developed by Chiron Corporation of Emeryville, California--the Chiron RIBA-HIV216 test system. Out of these cases, 172 autopsies were of individuals with no known risk factors for HIV infection, and of these, 169 had no detectable antibodies to HIV. In 2 cases, the serum reacted with p24 alone on the RIBA-HIV216 assay, but these results were not confirmed by further testing and are considered to be false positive reactions. In 1 case, the serum reacted only with gp41 on the RIBA-HIV216 test but was nonreactive with further testing. This result has been designated equivocal. Of the 35 cases at high risk of HIV infection, 4 had antibodies to HIV detected in postmortem serum samples. The sensitivity (100%) and specificity (98.5%) of the RIBA-HIV216 test system are high. However, the test appears to be more suitable for routine diagnosis of HIV infection than for rapid screening in the mortuary.

Firearm regulations and rates of suicide. A comparison of two metropolitan areas.

To investigate a possible association between firearm regulations and suicide, we compared the incidence of suicide from 1985 through 1987 in King County, Washington, with that in the Vancouver metropolitan area, British Columbia, where firearm regulations are more restrictive. The risk of death from suicide was not found to differ significantly between King County and the Vancouver area (relative risk, 0.97; 95 percent confidence interval, 0.87 to 1.09). The rate of suicide by firearms, however, was higher in King County (relative risk, 2.34; 95 percent confidence interval, 1.90 to 2.88), because the rate of suicide by handguns was 5.7 times higher there. The difference in the rates of suicide by firearms was offset by a 1.5-fold higher rate of suicide by other means in the Vancouver area. Persons 15 to 24 years old had a higher suicide rate in King County than in the Vancouver area (relative risk, 1.38; 95 percent confidence interval, 1.02 to 1.86). Virtually all the difference was due to an almost 10-fold higher rate of suicide by handguns in King County. We conclude that restricting access to handguns might be expected to reduce the suicide rate in persons 15 to 24 years old, but that it probably would not reduce the overall suicide rate.

Handgun regulations, crime, assaults, and homicide. A tale of two cities.

To investigate the associations among handgun regulations, assault and other crimes, and homicide, we studied robberies, burglaries, assaults, and homicides in Seattle, Washington, and Vancouver, British Columbia, from 1980 through 1986. Although similar to Seattle in many ways, Vancouver has adopted a more restrictive approach to the regulation of handguns. During the study period, both cities had similar rates of burglary and robbery. In Seattle, the annual rate of assault was modestly higher than that in Vancouver (simple assault: relative risk, 1.18; 95 percent confidence interval, 1.15 to 1.20; aggravated assault: relative risk, 1.16; 95 percent confidence interval, 1.12 to 1.19). However, the rate of assaults involving firearms was seven times higher in Seattle than in Vancouver. Despite similar overall rates of criminal activity and assault, the relative risk of death from homicide, adjusted for age and sex, was significantly higher in Seattle than in Vancouver (relative risk, 1.63; 95 percent confidence interval, 1.28 to 2.08). Virtually all of this excess risk was explained by a 4.8-fold higher risk of being murdered with a handgun in Seattle as compared with Vancouver. Rates of homicide by means other than guns were not substantially different in the two study communities. We conclude that restricting access to handguns may reduce the rate of homicide in a community.

Human blood stain identification and sex determination in dried blood stains using recombinant DNA techniques.

DNA was extracted from human and non-primate dried blood stains. Human male and female specimens were readily distinguished by analysis with a Y-chromosome specific DNA probe. Human and non-primate blood stains were also readily differentiated using a repeat sequence (Alu) DNA probe. The potential power of recombinant DNA analysis in forensic science is discussed.

Anatomico-radiological study of the borderline sella.

Multidirectional thin section tomography was performed on 62 excised sphenoidal bones. The pituitary gland was then sectioned and examined microscopically for evidence of microadenoma, cellular hyperplasia or cysts. There is absolutely no meaningful correlation between the radiological and the histological findings. Minor sellar changes in the form of slight irregularity of the lamina dura, asymmetry of the sellar floor or thinning of the dorsum sellae may be found in the absence of any histopathological abnormality.

CNS putative L-prolyl-L-leucyl-glycinamide (PLG) receptors, brain and lymphocyte dopamine receptors.

1. In view of previously demonstrated modulatory effects of PLG on the sensitivity of central dopamine receptors, we developed a radioligand binding assay to identify specific binding sites of PLG in rat and normal human brain. 2. 3H-PLG binds specifically to rat striatum exhibiting high affinity (KD = 4.69 +/- 0.50 nM) saturability (Bmax = 9.20 +/- 0.30 fmoles/mg protein) and reversibility; the highest density of specific PLG binding sites occurring in the striatum, followed by the hypothalamus and cerebral cortex. 3. Saturable, high-affinity binding sites of PLG were identified in human striatum. The substantia nigra was enriched with the highest level of specific PLG binding sites. 4. Dopamine receptors were identified in human lymphocytes. 5. The results are compatible with the hypothesis that differential modulation of CNS dopamine receptors by PLG is functionally associated with interacting with specific PLG binding sites in the rat and human brain, and pose implications for Parkinson's disease and tardive dyskinesia.

A model of cardiac arrhythmias and sudden death: cantharidin-induced toxic cardiomyopathy.

Toxic cardiomyopathy may result in fatal arrhythmias. To develop a model to study ventricular fibrillation and asystole, we investigated the effect of cantharidin in the production of cardiac arrhythmias and myocardial damage. Conscious albino rabbits, weighing between 1.8 to 2.8 kg received an intravenous bolus injection of cantharidin ranging from 0.6 to 1.9 mg/kg or a control injection of solvent. The electrocardiogram was continuously monitored on tape before and after injection for extended periods of time. Dose-related effects were observed with the following: 1) presence, magnitude and duration of ST depression after injection; 2) occurrence of fatal arrhythmias; 3) survival time (high doses were usually fatal within 3 hr); and 4) electron microscopic evidence of mitochondrial swelling, intramitochondrial granules and myofibrillar degeneration. The most common arrhythmias associated with the high doses of cantharidin were frequent ventricular ectopics, ventricular tachycardia, ventricular fibrillation or asytole. The arrhythmias could not be explained by alterations in blood pressure, electrolytes or blood gases. These findings show the cardiotoxic properties of cantharidin and its ability to produce fatal cardiac arrhythmias. Thus, it may serve as a model to study sudden death and the efficacy of antiarrhythmic drugs.

Pathological features of cantharidin-induced toxic cardiomyopathy: lack of correlation between electron-microscopic and histopathologic myocardial damage.

Electron-microscopic evidence of the cardiotoxic effects of cantharidin administered to rabbits was observed. No correlation was found between the electron-microscopic changes and the light-microscopic features as assessed by special histological stains. The reasons for this are discussed.

Drug-induced myocarditis: a report of two cases.

Two patients are reported with hypersensitivity myocarditis. One, a 71-year-old female, was being treated with methyldopa at the time of her death and the second, a 67-year-old female, was receiving tetracycline for a respiratory tract infection.

Definitions of ischaemia, infarction and necrosis.

Definitions of the terms ischaemia, infarction and necrosis are presented and their significance in connection with sudden cardiac death is discussed. Morphological features of acute myocardial fibre degeneration are reviewed and the significance of such findings are considered.

Apparent hypoxic changes in pulmonary arterioles and small arteries in infancy.

The pulmonary arterioles and small arteries were studied and their musculature and its nuclei were quantified in 90 neonates, infants, and young children who had suffered from a variety of clinical and hypoxic conditions immediately before death. Among the 90 cases investigated in this study, 30 were of sudden infant death syndrome (SIDS). No evidence was found to support the view that cases of SIDS are subjected to chronic hypoxia before death as significantly more medial muscle tissue in the pulmonary arterioles and small arteries was found in the chronic hypoxic group compared to the SIDS, non-hypoxic, and acute hypoxic groups. Furthermore, there was no statistically significant difference in the amount of medial muscle tissue of the pulmonary vessels as between the SIDS, non-hypoxic, and acute hypoxic groups. With other signs of acute hypoxia found at the necropsy of SIDS, the results of this study could be considered to support the view that cases of SIDS succumb as a result of an acute episode of hypoxia, or possibly repeated short-duration episodes of acute hypoxia which do not produce pulmonary vascular changes.

Fibrosis of the conducting tissue in infancy.

The conducting tissue of the heart was studied in a group of 38 cases of the sudden infant death syndrome and in a control group of 28 children dying of known causes. A variable amount of fibrous tissue was found in the atrioventricular complex in almost every case. There was a statistically significant increase in fibrous tissue with age in both groups and there was also significantly more fibrosis in the sudden infant death group compared with the controls. Possible explanations for these findings are discussed and it is suggested that the results might be of aetiological significance in the sudden infant death syndrome.

Role of respiratory viruses in childhood mortality.

Respiratory viruses have been identified at necropsy in the lungs of 13 out of 24 children who died with observed acute respiratory illness. The histological appearances of the lungs supported the association between virus and death in each of these 13 children and suggested an unidentified virus aetiology in a further five cases. Histological appearances compatible with bacterial infection were found in the lungs of only two of the 24 children. Similar virus and histological findings have been reported in about one-third of victims of the sudden infant death syndrome (cot deaths), indicating a rapid unobserved respiratory virus infection as the most likely mode of death in this group. Evidence that respiratory viruses may be involved in a larger proportion of sudden unexpected deaths, perhaps as antigens in a hypersensitivity reaction, is discussed. Respiratory viruses seem the major identifiable agents contributing to the maintenance of the postneonatal mortality rate since acute respiratory illness and the sudden infant death syndrome together account for about two-thirds of deaths at this age.