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.     

Test of the month: The chromogenic antifactor Xa assay

As the number of anticoagulant drugs increases and new ones are brought to market, the utility of the routine screening coagulation tests of today—namely the prothrombin time and activated partial thromboplastin time—will be significantly reduced in many clinical situations. Although the new anticoagulants are designed to require less frequent monitoring, it is imperative that the proper test is selected in situations where monitoring is needed. In addition, tests that are designed for the new generation of drugs may be informative in certain situations for monitoring the anticoagulants that have been in use for many years. Here, we present the chromogenic antifactor Xa assay and demonstrate its utility and its limitations in monitoring three anticoagulant drugs (unfractionated heparin, low molecular weight heparin, and fondaparinux) as well as one emerging anticoagulant, rivaroxaban. Am. J. Hematol. 2011. © 2011 Wiley‐Liss, Inc.     

Potential utility of plasma fatty acid analysis in the diagnosis of cystic fibrosis

BACKGROUND: An altered distribution of fatty acids in cells and tissues is found in patients with cystic fibrosis (CF). In this study, we assessed the potential role of plasma fatty acid analysis in the diagnosis of CF. METHODS: In this 2-part study, we first used gas chromatography-mass spectrometry to analyze fatty acids in plasma from 13 CF patients and 11 controls without CF. We then used the fatty acid distribution data to identify the fatty acids or multiple fatty acid calculations most effective in identifying CF patients. Part 2 of the study was a blinded analysis of 10 CF patients and 9 controls to directly test the effectiveness of the diagnostic parameters for CF identified from the plasma fatty acid analysis. RESULTS: In the nonblinded trial, the multiplication product of (18:2 n-6) x (22:6 n-3) (each as percentage of total plasma fatty acid) was the most effective indicator for distinguishing patients with CF from controls (P = 0.0003). In part 2 (the blinded trial), this multiplication product was also the most effective indicator for distinguishing CF patients from controls (P = 0.0008). CONCLUSIONS: The product of (18:2 n-6) x (22:6 n-3) is effective for distinguishing CF patients from persons without CF. This diagnostic marker may have value as an alternative to the sweat chloride test in selected patients being evaluated for CF.     

Fatty acid ethyl esters in human mononuclear cells: Production by endogenous synthesis greatly exceeds the uptake of preformed ethyl esters

BACKGROUND: Fatty acid ethyl esters (FAEE) are nonoxidative metabolites of ethanol. They are esterification products of ethanol and fatty acids. Fatty acid ethyl esters have been implicated as important mediators of ethanol-induced cytotoxicity, organ damage, and disease. In addition, they serve as specific and sensitive biomarkers for ethanol intake. Following ethanol consumption, FAEE are found in circulating blood bound to albumin or/and lipoproteins. OBJECTIVES: Using a mononuclear fraction of white blood cells (WBC) exposed to ethanol, we investigated FAEE synthesis. We then determined the amount of uptake of preformed FAEE presented to the cells and compared the amounts of FAEE within the cells that were derived from endogenous synthesis with the amount derived from uptake of exposure FAEE. We also measured the persistence of FAEE within these cells and assessed the fate of the FAEE-associated fatty acid upon FAEE hydrolysis. METHODS: A mononuclear fraction of human WBC was incubated with 25, 50, or 100 mM ethanol for 0.08 to 120 minutes, and FAEE synthesis was measured by gas chromatography/mass spectrometry. In other experiments, mononuclear cells were incubated with 25, 50, and/or 100 microM [3H]ethyl oleate, a representative FAEE species, for 0.08-120 minutes, and FAEE uptake and hydrolysis were measured. RESULTS: The total FAEE formed by treating the cells with 25 mM ethanol, which represents a physiologic dose achievable with excess alcohol intake, greatly exceeded the FAEE within cells derived from uptake of 100 microM ethyl oleate, which represents a supraphysiologic dose. There was hydrolysis of FAEE by human mononuclear cells, with free fatty acids as major metabolites of FAEE hydrolysis. Unlike any other cell type or homogenate studied, the only ethyl ester formed by human mononuclear cells exposed to ethanol was ethyl oleate. CONCLUSIONS: There is significant synthesis of FAEE by human mononuclear cells within seconds of exposure to physiologic doses of ethanol. The amount of FAEE in these cells derived from endogenous synthesis greatly exceeds the amount acquired by exogenous uptake.     

Suppression of monosodium urate crystal—induced acute inflammation by diets enriched with gamma-linolenic acid and eicosapentaenoic acid

A subcutaneous air pouch formed in Sprague-Dawley rats was used to study the effect of diets enriched in γ-linolenic acid (GLA) (in plant seed oil) and eicosapentaenoic acid (EPA) (in fish oil) on acute inflammation induced by monosodium urate crystals. The GLA-enriched diet suppressed significantly the cellular phase of inflammation (polymorphonuclear leukocyte accumulation, crystal phagocytosis, and lysosomal enzyme activity), but it had little effect on the fluid phase (exudate volume and protein concentration). In contrast, the EPA-enriched diet suppressed the fluid phase but not the cellular phase of inflammation. The findings indicate that the fluid and cellular phases of acute inflammation can be controlled independently. A combined diet of fish oil and plant seed oil (EPA-enriched and GLA-enriched) reduced both the cellular and fluid phases of inflammation. Thus, dietary provision of alternative substrates for oxidative metabolism (other than arachidonic acid) modifies monosodium urate crystal-induced acute inflammation.     

A double-blind dose-finding pilot study of docosahexaenoic acid (DHA) for major depressive disorder

We examined the antidepressant efficacy and dose-response pattern of the n-3 docosahexaenoic acid (DHA). Thirty-five depressed adult outpatients (46% women; mean age 42+/-14 years) with a 17-item Hamilton-Depression Scale (HAM-D-17) score of >/=18 were randomized into one of three double-blind dosing arms for 12 weeks. Group A (n=14): 1 g/day of oral DHA; Group B (n=11): 2 g/day; and Group C (n=10): 4 g/day. We measured HAM-D-17 scores, plasma DHA, eicosapentaenoic acid (EPA), and n-6/n-3 ratio. Completer response rates (>/=50% decrease in HAM-D-17 score) were 83% for Group A, 40% for Group B, and 0% for Group C; Groups A and B had significant decreases in HAM-D-17 scores (p<0.05). For completers and intent-to-treat subjects, plasma DHA increased significantly (p<0.05), EPA had little change (p>0.05), and n-6/n-3 decreased significantly (p<0.05). DHA may be effective for depression at lower doses.     

Oral docosahexaenoic acid given to pregnant mice increases the amount of surfactant in lung and amniotic fluid in preterm fetuses

OBJECTIVE: Our purpose was to determine whether docosahexaenoic acid increased surfactant production, as reflected by increased dipalmitoyl phosphatidylcholine, in mouse fetal lung and amniotic fluid. STUDY DESIGN: On day 9.5 of gestation, pregnant mice were given docosahexaenoic acid orally at 0, 5, 10, or 20 mg per day and were killed at day 16.5 (preterm) and day 19.5 (term) of gestation. Dipalmitoyl phosphatidylcholine was measured in fetal lung homogenates and amniotic fluid by high-performance thin-layer chromatography. RESULTS: Dipalmitoyl phosphatidylcholine values in lung were 0.22 +/- 0.27 microg/mg of total protein in preterm versus 1.96 +/- 0.57 microg/mg in term control fetuses. Pretreatment with 5, 10, or 20 mg docosahexaenoic acid increased dipalmitoyl phosphatidylcholine levels in preterm fetuses to 1.20 +/- 0.75, 1.60 +/- 0.67, and 3.28 +/- 0.44 microg/mg of protein, respectively. A similar trend was observed in amniotic fluid in which dipalmitoyl phosphatidylcholine levels were 1.86 +/- 3.70 microg/mL in preterm fetuses at baseline and increased to 7.81 +/- 1.21, 16.83 +/- 1.62 and 22.72 +/- 3.44 microg/mL after pretreatment for 7 days with 5, 10, and 20 mg docosahexaenoic acid (P<.05 compared to untreated mice). Dipalmitoyl phosphatidylcholine levels in amniotic fluid were 24.46 +/- 10.3 microg/mL in term control mice. CONCLUSION: The oral administration of docosahexaenoic acid to pregnant mice during pregnancy can induce dipalmitoyl phosphatidylcholine production and secretion, which is the major lipid component of surfactant.     

Hypercoagulability test strategies in the protein C and protein S pathway

The protein C-protein S pathway is critical in controlling normal clot formation to provide homeostasis between thrombosis and hemorrhage. Abnormalities have been described in which the pathway is altered because factor V cannot be degraded by activated protein C, producing activated protein C resistance. It has been known for nearly two decades that deficiencies in protein C and protein S can result in impaired inhibition of clot formation resulting in increased risk for thrombosis. This article describes the testing strategies associated with the diagnosis of activated protein C resistance, protein C deficiency, and protein S deficiency.