ABSTRACT
CONTEXT: Nitromethane interferes with Jaffé measurements of creatinine, potentially mimicking acute kidney injury. OBJECTIVES: We determined the proportional contribution of nitromethane in blood samples to creatinine measured by the Jaffé colorimetric and the point-of-care (POC) reactions and determined whether the difference can reliably estimate the concentration of nitromethane. Additionally, we determined whether the presence of nitromethane interferes with anion/osmolal gaps and ascertained the stability of nitromethane in serum after 7 days. METHODS: Nitromethane was added to whole blood from four healthy volunteers to achieve concentrations of 0, 0.25, 0.5, 1, and 2 mmol/L. The following tests were performed: creatinine (Jaffé and POC), electrolytes (associated with Jaffé and POC), osmolality and nitromethane concentration (gas chromatography [GC]). Remaining samples were refrigerated and reanalyzed using GC at 7 days. Anion and osmolal gaps were calculated. Proportional recovery and degradation of nitromethane were measured using GC. Data were analyzed for agreement with single-factor ANOVA (p = 0.05). RESULTS: Mean creatinine for POC and Jaff methods were 0.93 vs. 0.76 mg/dL, respectively. Jaff creatinine concentrations increased linearly with increasing nitromethane concentrations (R(2) = 1, p = 0.01): measured creatinine (mg/dL) = 7.1*nitromethane (mmol/L) = 0.79. POC creatinine remained unchanged across the range of nitromethane concentrations (p = 0.99). Anion and osmolal gaps also remained unchanged. Nitromethane was reliably identified in all sample concentrations using GC on Day 0. Detection of 0.25 mmol/L nitromethane was not consistently recovered on Day 7. Nitromethane degradation was most pronounced at 2 mmol/L concentrations (81% recovery). CONCLUSIONS: Nitromethane alters apparent concentration of creatinine using the Jaffé reaction in a linear fashion but not when using the POC reaction. Measured difference between Jaffé and POC creatinine may identify the presence and estimate concentration of nitromethane. Presence of nitromethane did not alter the anion or osmolal gap; thus it would not potentially interfere with the diagnosis of co-exposure to a toxic alcohol.
Subject(s)
Acid-Base Equilibrium , Creatinine/blood , Methane/analogs & derivatives , Nitroparaffins/blood , Osmolar Concentration , Point-of-Care Systems , Acid-Base Equilibrium/drug effects , Adolescent , Adult , Chromatography, Gas , Colorimetry , Female , Humans , Male , Methane/blood , Methane/pharmacokinetics , Methane/pharmacology , Nitroparaffins/pharmacokinetics , Nitroparaffins/pharmacology , Young AdultABSTRACT
OBJECTIVES: To assess safety, tolerability, pharmacokinetics and hemodynamic effects of oral CF 101, an A3 adenosine receptor (A3AR) agonist, in healthy men. METHODS: One single and 1 repeated dose, parallel-group, ascending dose, double-blind and placebo-controlled study in normal volunteers. In the single dose study, n = 15 subjects received 1, 5 or 10 mg oral CF101; in each group 1 subject received placebo, the remainder active CF101. In the repeat-dose study, n = 28 subjects received repeated 12-hourly oral doses of CF 101 (2, 3, 4 or 5 mg) for 7 days, in each group 2 subjects received placebo, the remainder active CF101. TEST MATERIALS: Single-dose study: CF101 in 30% Cremophor RH40. Multiple-dose sudy: CF101 in 0.5% methylcellulose suspension. Both studies: the corresponding vehicles were used as placebos. Galenicals were prepared remotely from the clinical study site to ensure double-blind nature of the study. RESULTS TOLERABILITY: Single doses up to 5 mg CF101 were safe and well-tolerated. However, the single dose of 10 mg CF101 was associated with flushing, tachycardia, nausea and vomiting, which were viewed as dose-limiting in normal volunteers. Single doses of CF101 (as well as the first of the multiple doses) were associated with increases in heart rate (8 - 24 beats/min after 5 mg and 18 - 55 beats/min after 10 mg). Multiple doses up to 4 mg 12-hourly for 7 days were safe and well-tolerated. However, the 5 mg multiple-dose group reported headache, drowsiness, hot flushes and dizziness on standing; this declined with dosing duration and was not dose-limiting in this study. Adverse events were commonest near t(max). RESULTS PHARMACOKINETICS: For oral CF101, the t(max) was always 1 - 2 h post-dose and t 1/2 about 9 h, in both the single- and multiple-dose studies. For a single 5 mg dose (mean +/- SD) C(max) = 81.6 +/- 23.6 ng/ml in the single dose study, and 63.6 +/- 22.0 ng/ml after the first of the multiple doses; AUC if was 904.0 +/- 221.9 ng.h/ml and 596.1 +/- 196.6 ng.h/ml for the 2 studies, respectively. After 7 days of multiple dosing there was little change, and AUC(0-24h) = 601.0 +/- 163.6 ng.h/ml. These pharmacokinetic parameters were linearly proportional to dose in the other treatment groups. RESULTS PHARMACODYNAMICS: Increases in heart rate were related to plasma concentration and evident only in the upper range of concentrations observed. There were no changes on ECG monitoring beyond sinus tachycardia, and, in particular, no evidence of PR prolongation in any subject (n = 43). In comparison with single doses, this response was almost absent after 7 days of dosing. Leucocytosis (increases up to about 1.5 x 10(9)/l after 5 and 10 mg) was similarly transient and reversible after multiple dosing. CONCLUSIONS: Single oral doses up to 5 mg CF101 and repeated doses up to 4 mg 12-hourly for 7 days were safe and well-tolerated. Multiple-dose CF101 pharmacokinetics were unchanged and predictable from single-dose estimates, and were linearly proportional to dose. Increases in heart rate and neutrophil count were reversible during multiple dosing and were not dose-limiting in the repeat dose study. CF101 warrants further study for its efficacy in treating human disease.
Subject(s)
Adenosine A3 Receptor Agonists , Adenosine/analogs & derivatives , Adenosine/pharmacokinetics , Adenosine/administration & dosage , Adenosine/adverse effects , Administration, Oral , Adult , Area Under Curve , Dose-Response Relationship, Drug , Double-Blind Method , Drug Tolerance , Half-Life , Heart Rate/drug effects , Humans , Leukocyte Count , Male , Neutrophils/metabolismABSTRACT
We report an unusual case of canebrake rattlesnake (Crotalus horridus atricaudatus) envenomation whose major manifestation was orolingual edema and airway compromise. The likely source of swelling was mucosal absorption of venom following the first aid technique of cutting and sucking the bite site. Except for airway compromise, the patient had mild local bite site effects (swelling) and mild systemic findings (depressed fibrinogen and elevated creatinine phosphokinase). He was managed with fiberoptic nasotracheal intubation and Crotalid antivenin with good outcome.
Subject(s)
Airway Obstruction/etiology , Crotalid Venoms/poisoning , Crotalus , Snake Bites , Administration, Oral , Adult , Airway Obstruction/therapy , Animals , Antivenins/therapeutic use , Crotalid Venoms/administration & dosage , Humans , MaleSubject(s)
Advanced Cardiac Life Support/methods , Advanced Cardiac Life Support/standards , Heart Diseases/chemically induced , Heart Diseases/therapy , Toxicology/methods , Toxicology/standards , Adrenergic Antagonists/poisoning , Adrenergic Antagonists/therapeutic use , Anti-Arrhythmia Agents/therapeutic use , Antidepressive Agents, Tricyclic/poisoning , Calcium Channel Blockers/poisoning , Cocaine-Related Disorders/complications , Evidence-Based Medicine , Heart-Assist Devices , Humans , Opioid-Related Disorders/complications , Poisoning/complications , Respiratory Insufficiency/chemically induced , Respiratory Insufficiency/therapy , Shock/chemically induced , Shock/therapy , Vasoconstrictor Agents/therapeutic useABSTRACT
Tetra-iso-propyl 2-(3,5-di-tert-butyl-4-hydroxyphenyl)ethyl-1,1-diphosphonate (CAS 126411-13-0, SR-9223i) is a member of a new class of compounds with multiple antiatherosclerotic activities. This report not only describes the cholesterol-lowering properties in four species of animals fed normocholesterolaemic diets but also reductions in lipid deposition in the arteries of cholesterol-fed New Zealand white rabbits following the administration of SR-9223i. Plasma cholesterol concentrations were reduced in mice by 27% (200 mg/kg/day administered in the diet for 10 days), in hamsters by 33% (200 mg/kg/day administered in the diet for 8 days), in dogs by 16% (25 mg/kg/day p.o. for 28 days) and 23% (75 mg/kg/day p.o. for 28 days) and in monkeys by 22% (25 mg/kg/day p.o. for 28 days). Further, the deposition of cholesterol, especially in the esterified form, in the aortae of cholesterol-fed New Zealand white rabbits was inhibited by SR-9223i (50 and 100 mg/kg/day p.o.). At the higher dose, the cholesteryl ester content of the aorta was half that of control animals. SR-9223i, at both doses, also inhibited the accumulation of cholesterol in the liver. SR-9223i has been shown to suppress HMG CoA reductase activity, inhibit ACAT activity and prevent lipid oxidation. These activities, demonstrated in vitro, have now been shown to translate into lipid lowering and antiatherosclerotic activities in vivo.
Subject(s)
Anticholesteremic Agents/pharmacology , Arteriosclerosis/drug therapy , Diphosphonates/pharmacology , Animals , Aorta/drug effects , Aorta/metabolism , Body Weight/drug effects , Cholesterol/blood , Cholesterol Esters/metabolism , Cholesterol, Dietary/pharmacology , Cricetinae , Diphosphonates/therapeutic use , Dogs , Lipoproteins/blood , Liver/drug effects , Liver/metabolism , Macaca fascicularis , Male , Mice , Rabbits , Species SpecificityABSTRACT
CASE REPORT: This case series documents the clinical courses of 4 patients after verapamil overdose and 1 patient after amlodipine-atenolol overdose. All subjects had hypodynamic circulatory shock (hypotension, bradycardia, and acidosis) that was not adequately responsive to conventional treatment. After initiation of insulin-dextrose infusion, the hemodynamic status of all 5 patients stabilized and all patients survived. Plasma drug concentrations are reported for all cases and verapamil levels were extremely high in 2 patients (3710 ng/mL and 3980 ng/mL). However, because patients were not treated according to a standard protocol, each patient received variable other supportive measures and inotropic agents, and the infusion rates of insulin were variable among patients. This report provides preliminary evidence toward a larger trial of insulin-dextrose to treat hypodynamic shock from calcium channel blocker overdose.
Subject(s)
Calcium Channel Blockers/poisoning , Glucose/therapeutic use , Hemodynamics/drug effects , Insulin/therapeutic use , Adolescent , Adult , Amlodipine/blood , Amlodipine/poisoning , Atenolol/blood , Atenolol/poisoning , Calcium Channel Blockers/blood , Chemotherapy, Adjuvant , Female , Humans , Male , Middle Aged , Suicide, Attempted , Verapamil/blood , Verapamil/poisoningABSTRACT
We have recently demonstrated that not all organs with high rates of mutation in the lacZ transgene develop tumors using the Muta Mouse. To better understand the role of in vivo mutation in carcinogenesis, we examined the mutant frequencies (MF) of the lacZ transgene in tumor-bearing and non tumor-bearing organs. MF, recovered after 2 weeks (the data taken from our previous study) and after 26 weeks following oral doses of 125 mg kg-1 day-1 benzo[a]pyrene (BP) for five days were compared. The organs examined included the target organs (forestomach, spleen, and lung) and non-target organs (colon, glandular stomach, and liver) for BP carcinogenesis. The data indicated that lacZ MF were markedly increased over spontaneous frequencies in the organs examined and that the organ which showed the highest MF was the colon, followed by the forestomach>spleen>glandular stomach, liver, and lung in that order. These findings indicate that the MF of the lacZ transgene in each organ, even 26 weeks after the start of the treatment does not fully correlate with the known target organs of BP. Furthermore, the lacZ MF in a non-papilloma region of a forestomach with a papilloma was equivalent to the two highest MF observed in the healthy colon (non-target organ) of mice at 26 weeks. These observations also indicate that the generation of tumors requires the induction of mutations as well as other factor(s) specific to the target organs. These results clearly suggest that highly mutated organs do not always progress to tumors in the transgenic mouse.
Subject(s)
Benzo(a)pyrene/pharmacology , Lac Operon , Mutation , Administration, Oral , Animals , Benzo(a)pyrene/administration & dosage , Carcinoma, Squamous Cell/chemically induced , Lung/drug effects , Lung/pathology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred DBA , Mice, Transgenic , Papilloma/chemically induced , Spleen/drug effects , Spleen/pathology , Stomach/drug effects , Stomach/pathologyABSTRACT
Several case reports and animal studies raise concerns over the risk of aspiration pneumonia when administering activated charcoal (AC) to intubated patients. Therefore, we sought to determine the incidence of aspiration pneumonia in intubated overdose patients who then received AC. We conducted a retrospective review from January 1994 to April 1997 of intubated patients who then received AC. Patients were transferred to, or primarily treated at, an 843-bed tertiary medical center with an annual emergency department volume of 100,000 patients. Objective evidence of infiltrate on chest radiograph during initial 48 h of hospitalization was used to determine the incidence of aspiration pneumonia. Patients with known preexisting pneumonia or with administration of AC before intubation were excluded. There were 64 patients identified. Fourteen were excluded for clinical aspiration before intubation, receiving activated charcoal before intubation, or abnormal immediate post-intubation chest radiographs. The remaining 50 patients, ages 1-64 years, 33% male, overdosing on a large variety of substances, required acute intubation and then received AC. Only two patients of these 50 (4%) with initial negative radiographs developed a new infiltrate after intubation and AC. Administration of AC to intubated overdose patients is associated with a low incidence of aspiration pneumonia.
Subject(s)
Antidotes/adverse effects , Charcoal/adverse effects , Intubation, Intratracheal/adverse effects , Pneumonia, Aspiration/etiology , Adolescent , Adult , Antidotes/therapeutic use , Charcoal/therapeutic use , Child , Child, Preschool , Drug Overdose/therapy , Emergencies , Female , Humans , Infant , Male , Middle Aged , Retrospective StudiesABSTRACT
OBJECTIVE: Toxic manifestations following ethylene glycol exposure are due to accumulation of metabolites, particularly glycolate. We characterized glycolate elimination kinetics and dialysis properties in a series of ethylene glycol poisonings. METHODS: Patients who ingested ethylene glycol and received fomepizole (4-methylpyrazole; 4-MP) +/- hemodialysis were prospectively evaluated. Serial blood samples for ethylene glycol, glycolate, pH, and bicarbonate were drawn to determine glycolate elimination rate, t1/2, and correlations between initial glycolate and initial markers of acidosis. Dialyzer inlet and outlet samples were obtained to measure hemodialysis glycolate clearance. Plasma ethylene glycol and glycolate were determined by gas chromatography. RESULTS: Ten patients, mean age 49 years (range 28-73 years), presented a mean of 10.5 hours (range 3.5-21.5 hours) after ethylene glycol ingestion. Mean initial ethylene glycol was 18.5 mmol/L (range 0.8-62.2 mmol/L) (115 mg/dL; range 5-386 mg/dL) and glycolate was 17.0 mmol/L (range 10.0-23.7 mmol/L). Nine of 10 underwent hemodialysis. Nonhemodialysis (n = 4) elimination rate was 1.08 +/- 0.67 mmol/L/h (mean +/- SD) and t1/2 was 626 +/- 474 minutes. Elimination t1/2 during hemodialysis (n = 8) was 155 +/- 42 minutes. Hemodialysis clearance (n = 5) was 170 +/- 23 mL/min with flow rates 250-400 mL/min. Pearson correlation coefficients were: anion gap vs glycolate r2 = 0.65 (p = 0.005), bicarbonate vs glycolate r2 = 0.10 (NS) and pH vs glycolate r2 = 0.06 (NS). CONCLUSION: Glycolate has a slow elimination rate and long half-life. Hemodialysis effectively clears glycolate. An increased anion gap correlates with the presence of glycolate. Hemodialysis is projected as useful for ethylene glycol-poisoned patients with anion gap acidosis and low ethylene glycol blood levels.
Subject(s)
Ethylene Glycol/pharmacokinetics , Ethylene Glycol/poisoning , Glycolates/blood , Renal Dialysis , Adult , Aged , Antidotes/therapeutic use , Chromatography, Gas , Ethylene Glycol/blood , Female , Fomepizole , Half-Life , Humans , Male , Middle Aged , Poisoning/therapy , Prospective Studies , Pyrazoles/therapeutic useABSTRACT
SKF-99085, an acyl-CoA:cholesterol acyltransferase (ACAT) was evaluated in male and female Sprague-Dawley rats at oral doses of 0, 10, 100, or 400 mg/kg/day for 6 months as part of the preclinical safety assessment of this drug candidate. In male rats given 400 mg/kg/day SKF-99085, hemorrhage and death were observed in males during the first month of the study, prompting collection of blood samples at weeks 6, 17, and 24 to monitor coagulation parameters. A dose-related increase in activated partial thromboplastin time (APTT) and Thrombotest clotting time (TCT) was observed in all male drug-treated groups. Mean APTT values for male rats given 10, 100, or 400 mg/kg/day were increased maximally to 17.5, 20.8, and 34.7 s (control, 15.4-16.0 s), and mean TCT values were increased to 86, 100, and >300 s (control, 71-74 s), respectively. Mean prothrombin times (PT) for male rats given 400 mg/kg/day were increased to 16.5 s (control, 12.9-13.1 s). Activities of factors II, VII, IX, and X were decreased in males at dosages of 10, 100, or 400 mg/kg/day. Factor V and VIII activities were unaffected. In summary, the drug-related hemorrhagic disorder observed in male rats given high doses of the ACAT inhibitor SKF 99085 was attributed to a reduction in the activity of vitamin-K-dependent coagulation factors. In contrast to humans and some other species, the APTT and TCT were more sensitive than the PT in detecting this effect.
Subject(s)
Acetyl-CoA C-Acyltransferase/antagonists & inhibitors , Anticholesteremic Agents/toxicity , Diphosphonates/toxicity , Enzyme Inhibitors/toxicity , Hemorrhage/chemically induced , Hemostasis/drug effects , Animals , Female , Hemorrhage/pathology , Male , Partial Thromboplastin Time , Prothrombin Time , Rats , Rats, Sprague-Dawley , Vitamin K/physiologyABSTRACT
SR-12813 inhibits cholesterol biosynthesis in Hep G2 cells via an enhanced degradation of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. Here we also show that SR-12813 inhibits cholesterol biosynthesis in vivo. A sterol balance study was performed in normolipemic beagle dogs. The dogs were given SR-12813 orally at dosages of 10 and 25 mg/kg/day for a period of 9 days. After 7 days plasma cholesterol was decreased by 15% in the 10 mg/kg/day group and by 19% in the 25 mg/kg/day group. Using a dual isotope technique no effects on intestinal cholesterol absorption were observed. The sterol balance indicated that endogenous synthesis of cholesterol was reduced by 23% in the 10 mg/kg/day group and by 37% in the 25 mg/kg/day group. Plasma lathosterol-cholesterol levels in dogs treated with 25 mg/kg/day SR-12813 were reduced by 56%, confirming a reduction of the cholesterol biosynthesis. Treatment with SR-12813 or the HMG-CoA reductase inhibitor lovastatin resulted in a large decrease in low density lipoprotein (LDL) cholesterol. It is concluded that SR-12813 reduces cholesterol biosynthesis in the dog model which results in a decrease of bile acid excretion, cholesterol excretion and plasma cholesterol level. The in vivo profile of SR-12813 is very similar to that of direct HMG-CoA reductase inhibitors, although the mode of action of the compound is unique.
Subject(s)
Anticholesteremic Agents/pharmacology , Cholesterol/biosynthesis , Cholesterol/blood , Diphosphonates/pharmacology , Administration, Oral , Animals , Anticholesteremic Agents/administration & dosage , Cholesterol, Dietary/metabolism , Cholesterol, LDL/blood , Diphosphonates/administration & dosage , Dogs , Enzyme Inhibitors/pharmacology , Evaluation Studies as Topic , Lipoproteins/blood , Lipoproteins/drug effects , Lovastatin/pharmacology , Male , Sterols/blood , Sterols/pharmacokineticsABSTRACT
The immunotoxicologic effects of drugs on host defense have been studied widely using various animal models of infection. Here we describe a new approach to testing host defense by using a single organism (Candida albicans) in CBA/J mice. The model is configured to test 3 effector systems via different routes of inoculation to stimulate different effector arms of the immune response. Nonspecific immunity was evaluated by C. albicans colony-forming unit (CFU) count from the spleen at 2 hr (uptake) and > or = 22 hr (clearance) following intravenous inoculation. Cell-mediated immunity was assessed by CFU count from an intramuscular injection site 6 days postinoculation. Humoral immunity was assessed by anti-Candida antibody titer, following multiple subcutaneous immunizations with C. albicans. Finally, overall immunity was evaluated following intravenous injection using survival as the endpoint. Histopathological, immunohistochemical, and electron microscopic evaluation of selected tissues revealed the involvement of the expected cell types in the different effector systems. Several immunomodulatory drugs--dexamethasone, cyclosporine, liposomal muramyltripeptide phosphatidylethanolamine, and SK&F 105685--were evaluated in the C. albicans model. Dexamethasone impaired host defense against C. albicans by suppressing all endpoints measured. Similarly, cyclosporine showed broad immunosuppressive activity, with the exception of yeast uptake from the spleen. In contrast, muramyl tripeptide-phosphatidylethanolamine enhanced all but cell-mediated immunity to C. albicans. SK&F 105685 displayed both stimulatory and inhibitory effects on immune responses to the infection. Our studies demonstrate that a single organism-based approach can be a useful method for evaluating the immunological hazards of drugs on host resistance to infection.
Subject(s)
Adjuvants, Immunologic/pharmacology , Candidiasis/drug therapy , Candidiasis/immunology , Adjuvants, Immunologic/toxicity , Animals , Antibody Formation/drug effects , Candida albicans/drug effects , Cyclosporine/administration & dosage , Cyclosporine/pharmacology , Dexamethasone/administration & dosage , Dexamethasone/pharmacology , Disease Models, Animal , Drug Evaluation, Preclinical/methods , Female , Immunity, Cellular/drug effects , Immunity, Innate/drug effects , Injections, Intraperitoneal , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Inbred CBA , Mice, Inbred DBA , Models, Immunological , Survival RateABSTRACT
OBJECTIVE: To evaluate whether measures that lower cytosolic calcium (Ca) can reverse propranolol (PROP) toxicity in the isolated, perfused rat heart. METHODS: Isolated rat hearts were perfused on a Langendorff apparatus with Krebs-Henseleit-bicarbonate (KHB) buffer solution. Toxicity was produced by perfusing the hearts with PROP (5 micrograms/mL) for 30 minutes. Subsequently, the hearts were treated for 30 minutes with buffer containing PROP plus experimental treatment. Three treatments were chosen: hypertonic sodium (Na) (160 mmol), to stimulate Na-Ca exchange, dantrolene (DAN) (10 mumol), to inhibit Ca release from sarcoplasmic reticulum, and combined hypertonic Na and DAN. The hearts were paced after 20 minutes of treatment. Heart rate (HR), left ventricular peak systolic pressure (LVP), the first derivative of LVP (dP/dt), and coronary flow were measured. RESULTS: PROP decreased HR and rendered the hearts refractory to pacing. PROP did not alter dP/dt. PROP increased LVP consistent with increased cytosolic Ca. Combined hypertonic Na and DAN treatment restored the ability to pace PROP-toxic hearts to the basal HR. Individually, hypertonic Na or DAN treatment partially restored the ability to pace toxic hearts. As experimental treatments increased HR, dP/dt and LVP decreased, consistent with decreased cytosolic Ca availability. CONCLUSION: These data are consistent with the hypothesis that bradycardia during beta-blocker cardiotoxicity is mediated by altered Ca homeostasis.
Subject(s)
Adrenergic beta-Antagonists/adverse effects , Dantrolene/pharmacology , Heart/drug effects , Muscle Relaxants, Central/pharmacology , Propranolol/adverse effects , Sodium/pharmacology , Animals , Calcium/physiology , Cardiac Pacing, Artificial , Cytosol/drug effects , Heart Rate/drug effects , Homeostasis/drug effects , In Vitro Techniques , Male , Rats , Rats, Sprague-Dawley , Ventricular Pressure/drug effectsABSTRACT
STUDY OBJECTIVE: To compare the efficacy of a novel antidote, insulin, with standard treatments, glucagon and epinephrine, in a canine model of acute beta-blocker toxicity. METHODS: Anesthetized dogs were fitted with instruments by means of thoracotomy and vascular cutdown for multiple cardiodynamic, hemodynamic, metabolic, and electrical measures. After basal measurements were taken, animals received intravenous propranolol (.25 mg/kg/minute) continuously for the remainder of the experiment. Toxicity was defined as a 25% decrease in the product of heart rate times mean blood pressure. Thirty minutes after the development of toxicity, toxic measures were taken (treatment 0 minutes), and then the animals (n = 6 each group) received either sham (saline solution), insulin (4 IU/minute with glucose clamped), glucagon (50 micrograms/kg bolus, then 150 micrograms/kg/hour infusion), or epinephrine (1 microgram/kg/minute). Animals were monitored until death or for 240 minutes. RESULTS: Propranolol decreased contractility, left ventricular pressure, and systemic blood pressure, and resulted in death of all sham-treated animals by 150 minutes. Six of six insulin-treated, four of six glucagon-treated, and one of six epinephrine-treated animals survived. Survival was greater for insulin-treated animals, compared with either glucagon-treated (P < .05) or epinephrine-treated animals (P < .02) by the log-rank test. Insulin-treated animals were characterized by improved cardiodynamics and hemodynamics, increased myocardial glucose uptake, and decreased serum potassium. CONCLUSION: Insulin is a superior antidote compared with glucagon or epinephrine in an anesthetized canine model of acute beta-blocker toxicity.
Subject(s)
Adrenergic beta-Antagonists/poisoning , Antidotes/therapeutic use , Hypoglycemic Agents/therapeutic use , Insulin/therapeutic use , Propranolol/poisoning , Acute Disease , Adrenergic beta-Agonists/therapeutic use , Animals , Disease Models, Animal , Dogs , Drug Evaluation, Preclinical , Drug Monitoring , Epinephrine/therapeutic use , Glucagon/therapeutic use , Hemodynamics/drug effects , Poisoning/drug therapy , Survival AnalysisABSTRACT
Cocaine is a local anesthetic with the potential to induce dysrhythmia due to direct myocardial sodium channel antagonism similar to class I antidysrhythmic drugs. The hallmark of myocardial sodium channel poisoning is wide complex dysrhythmia, and the current accepted treatment is intravenous bicarbonate. Wide complex dysrhythmio due to cocaine in the absence of myocardial infarction is rare, and optimum management is undefined. We report three cases of acute cocaine intoxicating during which patients developed wide complex dysrhythmia consistent with sodium channel poisoning. In one case, wide complex tachycardia resolved without direct treatment. In the other cases, wide complex dysrhythmia resolved following intravenous bicarbonate therapy directed at reversing sodium channel blockade.
Subject(s)
Arrhythmias, Cardiac/chemically induced , Cocaine/poisoning , Narcotics/poisoning , Adult , Arrhythmias, Cardiac/diagnosis , Arrhythmias, Cardiac/drug therapy , Electrocardiography , Epilepsy, Tonic-Clonic/chemically induced , Female , Humans , Male , Sodium Bicarbonate/therapeutic use , Sodium Channels/drug effectsABSTRACT
We introduce here a new fluorescence microscopy technique for en face analysis of the atherosclerotic fatty streaks (FS). This technique is semiquantitative and has the sensitivity and resolution to map lipids to individual cells in FS less than 100 microns in diameter. New Zealand White rabbits were fed an atherogenic diet for up to 26 weeks. Aortas were fixed in formalin and stained en bloc with the fluorescent dyes Nile red and filipin. Fluorescent staining was validated by correlating microfluorimetric and biochemical measurements of the lipid content in FS. To determine the cell types associated with the different staining patterns, FS were also evaluated by transmission electron microscopy (TEM) and immunohistochemistry (IH). Correlation of microfluorimetry, TEM, IH, and biochemical data indicated that regions rich in non-esterified cholesterol stained with filipin and fluoresced blue owing to accumulations of lipid vesicles and/or cholesterol crystals. Regions rich in neutral and polar lipids stained with Nile red and fluoresced yellow or orange, respectively, owing to accumulations of lipids in both macrophages and smooth muscle cells (SMC). Digital overlays of the filipin and Nile red images revealed that larger lesions (> 0.5 mm diameter) had a "nested" distribution of lipids, with a blue (filipin) fringe surrounding an orange (Nile red) fringe surrounding a yellow (Nile red) center.
Subject(s)
Arteriosclerosis/metabolism , Lipids/analysis , Microscopy, Fluorescence , Animals , Arteriosclerosis/pathology , Biopsy , Disease Models, Animal , Rabbits , Time FactorsABSTRACT
Alterations of the cardiac membranous ventricular septum were studied using macrodissection, scanning electron and light microscopy of fetal, weanling, and adult Sprague-Dawley rats. Membranous ventricular septal defects (VSDs) were observed in 2.0% of fetuses on day 21 postcoitus (pc) but not in weanling or adult rats. The most common observation was a nonpatent depression in the membranous septum with an incidence of 38.1, 10.5, 4.3% for fetuses on days 17, 19, or 21 pc, respectively, 11.8% for weanlings, and 9.1% for adults. VSDs were characterized by a split in the endocardial cushion cells in the interventricular component of the membranous septum. Nonpatent depressions were characterized by a split in the endocardial cushion cells in the atrioventricular component of the septum, and they persisted postnatally as a blind-ended diverticulum directed above the tricuspid valve. The cardiovascular teratogens, trimethadione and trypan blue, produced in fetuses nonpatent depressions and VSDs morphologically similar to untreated fetuses. Maternal diet restriction (25% of controls) lowered fetal (day 21 pc) body weight by 47% but did not affect the incidence of ventricular septal alterations, suggesting that intrauterine growth retardation is not necessarily associated with alterations in the development of the ventricular septum. We conclude that neither VSDs nor nonpatent depressions in Sprague-Dawley rats affect postnatal survival and that VSDs close spontaneously during neonatal life.
Subject(s)
Heart Septal Defects, Ventricular/etiology , Heart Valves/abnormalities , Heart Ventricles/abnormalities , Animals , Diet, Reducing/adverse effects , Female , Fetal Growth Retardation/complications , Fetus , Heart Septal Defects, Ventricular/embryology , Heart Valves/embryology , Male , Microscopy, Electron, Scanning , Rats , Rats, Sprague-Dawley , Time Factors , Trimethadione/toxicity , Trypan Blue/toxicityABSTRACT
This note has reviewed the extent of protection of workers against income loss during the first 6 months of illness or injury. National income loss in 1994 was $81.1 billion, of which $49.4 billion (60.9 percent) was replaced by income-protection programs, including sick leave, group insurance, temporary disability insurance under statutory State provisions, individual insurance, workers' compensation, and (during the 6th month) the Social Security Disability Insurance program. In 1994, wage and salary workers in the private sector lost $55.2 billion because of nonoccupational illnesses or injuries, of which $19.0 billion (34.5 percent) was replaced. Wage replacement rates are higher for full-time professional and technical employees with longevity in large or medium firms, and especially public employees. The lowest level of coverage is given to part-time employees with limited seniority who work in production and related areas in small, private firms. Approximately 70 percent of wage and salary workers in the private sector have some protection through their employment against earnings losses caused by short-term illness. Forty-four percent of these workers have short-term disability insurance,and only half have sick-leave coverage.
Subject(s)
Acute Disease/economics , Cost of Illness , Disabled Persons/statistics & numerical data , Insurance, Disability/statistics & numerical data , Health Benefit Plans, Employee/statistics & numerical data , Health Benefit Plans, Employee/trends , Humans , Income/statistics & numerical data , Income/trends , Insurance Benefits/statistics & numerical data , Insurance Benefits/trends , Insurance, Disability/trends , Sick Leave/statistics & numerical data , Sick Leave/trends , United States , Workers' Compensation/statistics & numerical data , Workers' Compensation/trendsSubject(s)
Private Sector/economics , Social Welfare/economics , Education/economics , Education/statistics & numerical data , Employment/economics , Health Expenditures/statistics & numerical data , Health Expenditures/trends , Humans , Insurance, Disability/economics , Pensions/statistics & numerical data , Public Sector/economics , Social Work/economics , Social Work/statistics & numerical data , United StatesABSTRACT
Drugs that inhibit the low-Km, cGMP-inhibitable form of phosphodiesterase III (PDE III) are associated with arterial lesions in the extramural coronary arteries of dogs following oral and intravenous administration at high doses. Acute coronary arterial lesions have been investigated following administration to the dog of SK&F 95654, a potent PDE III inhibitor, and the progression of the lesion defined. Groups of 3 male beagle dogs received a single 2-hr infusion of SK&F 95654 at 8 mg/kg/hr and the characteristics of the coronary arterial lesions were evaluated at 1, 3, 10, and 34 days postdosing by light, scanning, and transmission electron microscopy. At 24 hr postdosing, the arterial lesion was characterized by segmental or circumferential necrosis of medial smooth muscle cells and hemorrhage; adventitial hemorrhage was also noted, particularly in the right atrial artery. Ultrastructural evaluation showed extensive medial necrosis, characterized by loss of smooth muscle cells and their replacement by cellular debris with ingress of erythrocytes, platelets, and inflammatory cells into the media. Associated with medial changes, significant endothelial effects were observed consisting of widening of intercellular boundaries, loss of normal elongated cellular appearance, and the attachment of numerous leukocytes and platelets. During the 10-34-day postdosing period, substantial repair of the arterial lesions occurred such that by day 34 all sections of extramural coronary artery were normal. The lesions induced in the dog are consistent with a hemodynamic effect induced by the pharmacological action of SK&F 95654.