Phylogenetically distinct hantavirus implicated in a case of hantavirus pulmonary syndrome in the northeastern United States.

Hantavirus pulmonary syndrome (HPS) is an acute respiratory illness with high mortality. It is caused by a newly described New World hantavirus known as Four Corners virus (FCV). Nearly all cases of HPS have occurred in the western United States. The etiologic agents in those cases have been closely related to each other, based upon comparisons of their genetic sequences. We have molecularly cloned the S genomic segment of a hantavirus (Rl-1) implicated in a case on HPS in the northeastern United States. Nucleotide sequence analysis shows that the Rl-1 virus has many similarities to FCV, but is clearly distinct from the western forms of that virus. These data suggest that HPS can be caused by multiple agents that together form a distinctive evolutionary clade.

A review of pulmonary pathology and mechanisms associated with inhalation of freebase cocaine ("crack").

The use of cocaine in the United States has reached near epidemic proportions. A major factor responsible for the dramatic increase in cocaine use is the ability to freebase cocaine and extract essentially pure drug to be smoked as crack. As a result, a variety of respiratory problems temporally associated with crack inhalation have been reported. Cocaine may cause changes in the respiratory tract as a result of its pharmacologic effects exerted either locally or systemically, its method of administration (smoking, sniffing, injecting), or its alteration of central nervous system neuroregulation of pulmonary function. These changes include such diverse disorders as thermal airway injury, pulmonary edema and hemorrhage, hypersensitivity reactions, and interstitial lung disease. However, a review of the pulmonary pathology and dysfunction associated with crack and/or cocaine use indicates that the reported changes are most likely multifactorial, even idiosyncratic, and fails to reveal common features diagnostic of cocaine use. It is likely that the spectrum of cocaine-induced pulmonary disease will continue to enlarge.

Sagittal liver transection--an injury from improperly worn shoulder harness seatbelts: a report of two cases.

We have identified two cases which exemplify the typical injury caused by the under-the-arm placement of a shoulder harness (without the associated lap belt) in frontal collisions, namely, fatal liver laceration in the sagittal plane. Trauma care personnel should be alert for this type of rapidly fatal abdominal injury that occurs even in low-speed impacts. A prominent warning label on these belts regarding proper placement and the need for use of the associated lap belt may be appropriate.

Normal human synovial fluid and articular cartilage contain similar intact proteoglycans.

This work, directed to characterization of proteoglycans present in normal human synovial fluid by Western blotting techniques, revealed an intimate relationship of these proteoglycans to those of articular cartilage. Analyses were performed on samples subjected to digestion with chondroitinase ABC, in the presence or absence of keratanase, yielding products containing core proteins with glycosaminoglycan side chain stubs. The proteoglycan core proteins contained epitopes reactive with monoclonal antibodies that distinguish between chondroitin sulfate-4 and chondroitin sulfate-6. Additionally, these products reacted with monoclonal antibody to keratan sulfate when keratanase was omitted from the digestion. The analysis of synovial fluid revealed that the proteoglycan core proteins expressed predominantly the chondroitin sulfate-6 epitope, with expression of the chondroitin sulfate-4 epitope demonstrable only in prepubertal individuals. There was coexpression of both chondroitin sulfate epitopes in all proteoglycan core proteins of prepubertal individuals. Coexpression of chondroitin sulfate and keratan sulfate epitopes occurred in all proteoglycan core proteins. Proteoglycan core proteins had M(r) similar to those obtained from articular cartilage. Hence, in individuals free of joint disease, most proteoglycans seem to be transferred from articular cartilage to the synovial fluid without major alteration in the apparent size of the proteoglycan core protein. Only a minor set of proteoglycan core proteins had no direct articular cartilage equivalent. As this set also contained keratan sulfate, it is likely to be of articular cartilage origin, but probably modified by proteolysis.

Passive inhalation of free-base cocaine ('crack') smoke by infants.

Cocaine is one of the most widely abused substances in the United States, in part due to the availability of its inexpensive alkaloidal free-base form, "crack". A variety of medical complications, including sudden death, are known to occur in the adult-user population, regardless of the route of cocaine administration. We report 16 cases of infant death registered by the Philadelphia (Pa) Medical Examiner's Office over a 2-year period (1987 through 1989), where toxicologic analyses revealed the presence of cocaine and/or its metabolite, benzoylecgonine. Scene investigation documented that these infants, shortly before death, had been exposed to environments that contained the smoke from crack. We conclude that the route of cocaine administration in this infant population was the passive inhalation of crack smoke. It is possible that the cocaine may have contributed to the death of these infants. Thus, in addition to the adult users, infants and children exposed to environments where crack is smoked may inhale cocaine and potentially suffer from its adverse effects.

Cocaine-induced heart disease: mechanisms and pathology.

Cocaine use has increased in recent years, in part as a result of the increased availability of "crack," the inexpensive freebase form. Although it is used medicinally and initially was considered a relatively safe street drug, cocaine clearly has addictive potential as well as adverse health consequences even in low doses. Some of its most serious adverse effects involve the cardiovascular system. Understanding the cellular mechanisms of the action of cocaine on the heart allows insight into the pathophysiology of its adverse effects. Blockade of sodium channels accounts for cocaine's anesthetic effects and acts directly on myocytes to impair action potential generation and conduction, predisposing to dysrhythmias. Blockade of neurotransmitter reuptake has many deleterious effects, including dysrhythmogenesis via increased intracellular calcium, myocardial ischemia via vasospasm and increased myocardial oxygen demand, and contraction band necrosis also via increased intracellular calcium. In addition, alterations in platelet-endothelial cell function predispose to coronary artery thrombosis and ischemia. Alterations in immune function of natural killer cells may, among other effects, predispose to the development of myocarditis, the etiology of which is probably multifactoral. Finally, a direct toxic effect of cocaine on myocytes may, in some cases, produce heart muscle dysfunction. These multiple mechanisms of action combined with the deleterious effects of often-present adulterants give rise to an unpredictable, variable, and potentially life-threatening cardiovascular response to cocaine administration.

Synthesis and degradation of fatty acid ethyl esters by cultured hepatoma cells exposed to ethanol.

Fatty acid ethyl esters are a family of neutral lipids that are the products of esterification of fatty acids with ethanol. Unlike other pathways of ethanol metabolism, ethyl esters are present in numerous human organs which are the targets of ethanol-induced damage. In the present study, we have shown that fatty acid ethyl esters are synthesized by a hepatoma cell line in tissue culture when exposed to ethanol concentrations easily attained by man during social drinking. Unlike alcohol dehydrogenase, the enzyme(s) responsible for synthesis of ethyl esters are membrane-bound and concentrated in the microsomal fraction of rat hepatocytes. In addition, fatty acid ethyl esters are hydrolyzed to free fatty acids and ethanol by membrane-bound enzyme(s) that are enriched in the microsomal and mitochondrial-lysosomal fractions. Intracellular hydrolysis of fatty acid ethyl esters release free fatty acids which are preferentially incorporated into cellular cholesterol esters. Thus, we have shown that a hepatocellular line exposed to concentrations of ethanol easily achieved in man by social drinking utilize endogenous fatty acids to form long-lived ethanol metabolites, fatty acid ethyl esters. Importantly, this family of neutral lipids may act as biochemical mediators of ethanol-induced cell damage, including the changes in cholesterol metabolism noted in chronic alcoholics.

Fatty acid ethyl esters in adipose tissue. A laboratory marker for alcohol-related death.

Fatty acid ethyl esters, a family of ethanol metabolites, are formed by esterification of ethanol with fatty acids and have been detected in human organs commonly damaged by ethanol abuse. Because alcohol-related deaths may occur up to six times as often as reported on death certificates, we undertook quantitation of these potentially longer-lived alcohol metabolites in postmortem human adipose tissue to assess their usefulness as a measure of recent ethanol exposure. After isolation and identification using sequential thin-layer and gas chromatography, fatty acid ethyl esters were present in adipose tissue of chronic alcoholics (mean +/- SEM equals 300 +/- 46 nmol/g), even though blood ethanol concentration at the time of death was undetectable. Unintoxicated nonalcoholic subjects who had no history of alcohol abuse had concentrations seven times lower (mean +/- SEM equals 43 +/- 13 nmol/g). In vitro studies demonstrate that fatty acid ethyl esters are synthesized by human adipose tissue in proportion to the ethanol concentration present and their half-life in adipose tissue of laboratory animals is 16 +/- 1.6 hours, ie, fourfold greater than that of alcohol. These results indicate that fatty acid ethyl esters are long-lived ethanol metabolites whose persistence and accumulation in adipose tissue may allow an accurate diagnosis of significant alcohol consumption even when ethanol has been completely eliminated from the body.

Hepatic lipase in the rat ovary. Ovaries cannot synthesize hepatic lipase but accumulate it from the circulation.

Hepatic lipase is proposed to have a role in steroidogenesis through its involvement in the metabolism of high density lipoproteins. We examined the activity, synthesis, distribution, and uptake of this enzyme and assessed the content of its mRNA in luteinized ovaries. We found that during peak steroidogenesis, ovaries of pregnant mare's serum gonadotropin-human chorionic gonadotropin-treated immature rats contained heparin-releasable hepatic lipase-like activity which was neutralized in a dose-dependent manner by purified antibodies to hepatic lipase isolated from post-heparin perfusates of rat livers. Quantitative immunoelectron microscopy revealed that ovarian hepatic lipase occurred along endothelial cells and was 3-fold more abundant in blood vessels of corpora lutea than those of stroma. However, hepatic lipase was not synthesized by the ovary since radiolabeled enzyme was not immunoisolated from the medium of dispersed luteinized granulosa cells incubated with [35S]methionine whereas it was present in the medium of control cells (hepatocytes). Similarly, hepatic lipase mRNA was detectable in liver but not ovaries or kidneys by Northern or slot blot analyses or by the polymerase chain reaction. Finally, 125I-labeled hepatic lipase injected into tail veins was quickly cleared from the systemic circulation, accumulating in liver, ovaries, kidneys, and spleen. Subsequent heparin injection caused rapid reappearance of radioactivity in the bloodstream and a marked decline of radiolabel in liver and ovaries but a modest decrease of that in kidneys and none in spleen. Exogenous 125I-bovine serum albumin also accumulated in all four organs but was not displaced from liver or ovaries by subsequent administration of heparin. Taken together, these data suggest that steroidogenically active ovaries possess but do not synthesize hepatic lipase. Instead, hepatic lipase originating elsewhere, presumably in the liver, is accumulated from the circulation at heparin-sensitive sites in ovarian blood vessels.

Evaluation of sudden death in psychiatric patients with special reference to phenothiazine therapy: forensic pathology.

The investigation of sudden unexpected death in psychiatric patients and the ensuing litigation has brought to our attention many unusual features important in the evaluation of such deaths. Certain pathophysiologic mechanisms of death, rarely encountered in routine forensic science practice, may be important in determining the cause of death in psychiatric patients, especially in cases where the autopsy is unrevealing. Of particular concern is a tendency in the current literature to implicate phenothiazines as a cause of death when the death investigation and the autopsies are incomplete. Thus, based on our experience and on a review of the current literature, we have set forth factors that the forensic pathologist should consider when faced with a sudden psychiatric death. A case report illustrates these unique aspects of scene investigation and analysis of terminal events and autopsy findings.

Metabolism of ethanol by human brain to fatty acid ethyl esters.

Although the most prominent acute and chronic effect of alcohol ingestion in man is alteration of brain function, metabolism of ethanol by human brain has not been documented. This study was designed to detect and localize a new family of nonoxidative ethanol metabolites, fatty acid ethyl esters, in human brain and characterize their synthetic pathways. Fatty acid ethyl ester synthase activity was present in 10 different locations in human brain, with gray matter containing more activity than white matter (0.53 nmol of ethyl oleate/mg of protein/h and 0.25 nmol of ethyl oleate/mg of protein/h, respectively). Two forms of this synthase, present in cytosol or loosely bound to membrane fractions, were isolated from human gray and white matter and then partially purified by ion-exchange chromatography. Both were active at low ethanol concentrations easily attained in vivo in man. Importantly, fatty acid ethyl esters were also detected in brains of individuals dying while intoxicated; only small amounts were present in control subjects at autopsy. Thus, alcohol metabolism in human brain has been documented for the first time by identifying both fatty acid ethyl esters and their synthases in this important target-organ of alcohol abuse.

Hepatic lipase. Synthesis, processing, and secretion by isolated rat hepatocytes.

Hepatic lipase, a glycoprotein synthesized and secreted by the hepatocyte, binds to sinusoidal endothelium where it is involved in metabolism of lipoprotein phospholipid and triglyceride. To better understand the regulation of hepatic lipase, we investigated the synthesis, post-translational processing, and secretion of the enzyme by isolated rat hepatocytes. Metabolically labeled [35S]methionine hepatic lipase protein, produced by the collagenase-dispersed hepatocytes, was immunoisolated from detergent-solubilized cells and incubation medium at designated times, using a polyclonal rabbit anti-rat hepatic lipase antibody raised against hepatic lipase purified to homogeneity from rat liver post-heparin perfusates. Following polyacrylamide gel electrophoresis and fluorography, radiolabeled hepatic lipase was quantitated by densitometry. Newly synthesized hepatic lipase was rapidly secreted and accumulated in the medium as a 59,000-dalton protein in a manner consistent with a constitutive process. An intracellular 53,000-dalton precursor of the mature 59,000-dalton hepatic lipase was identified by immunoprecipitation. The 53,000-dalton form could also be generated by endoglycosidase digestion of the secreted 59,000-dalton protein. In pulse-chase experiments, the 53,000-dalton protein was converted into the 59,000-dalton form. A 47,000-dalton form of hepatic lipase was immunoisolated from cell lysates only after tunicamycin treatment and could be generated from the secreted 59,000-dalton enzyme by prolonged endoglycosidase digestion. These data show that hepatic lipase is synthesized and rapidly secreted by isolated rat hepatocytes. Further, an intracellular 47,000-dalton precursor peptide can be identified after tunicamycin treatment, which may represent the hepatic lipase polypeptide, presumably after removal of its signal sequence; a 53,000-dalton partially glycosylated peptide exists as a major precursor form in the cell; and the mature 59,000-dalton hepatic lipase is present in the hepatocyte, but it is rapidly secreted.

Thrombomodulin, an endothelial anticoagulant protein, is absent from the human brain.

Protein C activation by thrombin is significantly accelerated by the endothelial cell cofactor, thrombomodulin. In this study, we have developed a radioimmunoassay for thrombomodulin and have measured the cofactor content in several human tissues. The assay method detects as little as 2 ng of thrombomodulin. The highest thrombomodulin content was found in lung and placenta, but the antigen was also detected in spleen, pancreas, liver, kidney, skin, heart, and aorta. Unexpectedly, thrombomodulin was absent from brain. Extracts from cerebral cortex, cerebellum, centrum semiovale, midbrain, basal ganglia, pons, and medulla were devoid of thrombomodulin. In contrast, thrombomodulin antigen is present in extracerebral intracranial vessels, including basilar and internal carotid arteries and choroid plexus, as well as in endothelium of the pia-arachnoid.

Presence of nonoxidative ethanol metabolism in human organs commonly damaged by ethanol abuse.

Acetaldehyde, the end product of oxidative ethanol metabolism, contributes to alcohol-induced disease in the liver, but cannot account for damage in organs such as the pancreas, heart, or brain, where oxidative metabolism is minimal or absent; nor can it account for the varied patterns of organ damage found in chronic alcoholics. Thus other biochemical mediators may be important in the pathogenesis of alcohol-induced organ damage. Many human organs were found to metabolize ethanol through a recently described nonoxidative pathway to form fatty acid ethyl esters. Organs lacking oxidative alcohol metabolism yet frequently damaged by ethanol abuse have high fatty acid ethyl ester synthetic activities and show substantial transient accumulations of fatty acid ethyl esters. Thus nonoxidative ethanol metabolism in addition to the oxidative pathway may be important in the pathophysiology of ethanol-induced disease in humans.

Collection of trace evidence from bombing victims at autopsy.

The body recovered from the scene of a bombing may contain important trace evidence that links the suspect to the crime. Recognizing the lack of guidelines for evidence removal from the body, we have prepared a protocol to guide the pathologist in the collection of trace evidence from the bombing victim. Case material used in the development of the protocol included 13 bombing fatalities reported to the St. Louis Medical Examiner's Office since 1975.