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Biomedical subjects

S Winbery

Publications and source records attributed to S Winbery.

14 recordsLinked to original sources
PubMed2000

Blood cocaine and metabolite concentrations, clinical findings, and outcome of patients presenting to an ED.

The purpose was to determine if blood cocaine or metabolite concentrations would accurately reflect the severity of clinical findings in patients presenting to the emergency department, identifying those requiring therapeutic intervention or those at risk for poor outcome. Blood for determination of cocaine and metabolite concentrations was drawn from patients and were determined by an extractive alkylation/mass spectrometry procedure. The mean blood concentrations (mg/L) in 111 patients were as follows: cocaine, 0.26 +/- 0.5; ecgonine 0.42 +/- 0.47; ecgonine methyl ester 0.21 +/- 0.37, norcocaine 0.03 +/- 0.17; benzoylecgonine 1.28 +/- 1.29, cocaethylene 0.02 +/- 0.06. Two patients died, 23 required hospital admission, and 88 were discharged from the ED. There was no statistical correlation between cocaine or any metabolite concentration and the severity of clinical symptoms, disposition, need for treatment or outcome. Blood cocaine and metabolite concentrations should be interpreted with caution because they vary widely and do not predict the severity of clinical findings, the incidence of adverse effects, outcome, or need for interventional therapy.

Adolescent↗
PubMed2000

Cocaine metabolism in hyperthermic patients with excited delirium.

The half-life of cocaine in clinical experiments has been reported to range from 60 to 90 min. It has been previously suggested that elevated temperature may accelerate the metabolism of cocaine. However, there is no clinical data to indicate the presence of hyperthermia like that seen in excited delirium alters the half-life of cocaine. We report the results of half-life determinations from serial cocaine concentrations in two patients with excited delirium. Both patients presented to the emergency department with classic findings of excited delirium that included hyperthermia, agitation, and cardiovascular aberrations. One patient died despite aggressive therapeutic intervention. Cocaine and metabolite concentrations were determined by an extractive alkylation mass spectrometry procedure. Presenting cocaine concentrations in patient 1 and patient 2 were 0.387 and 0.266 mg/L respectively. Results from pharmacokinetic modeling of the serial concentrations show that the half-life of cocaine was not significantly accelerated, despite the presence of hyperthermia. Data from these two cases provide further evidence that catastrophic reactions to cocaine are independent of amount or route of administration, and that the metabolism of cocaine, at least in these patients, was not altered by hyperthermia.

Journal Article↗
PubMed1998

Multiple cocaine-induced seizures and corresponding cocaine and metabolite concentrations.

The etiology of seizures associated with cocaine use is unclear. Because cocaine seizures are relatively uncommon, they should be diagnosed by exclusion and a neurological workup to rule out central nervous system (CNS) catastrophe should be made. This report describes the clinical findings, treatment, and blood cocaine and metabolite concentrations in a patient who, on two separate occasions, had seizures associated with crack cocaine ingestion. Approximately 1 hour after the ingestion incidents, the patient had multiple, generalized seizures that abated spontaneously. His workup for CNS bleeding, infection, and trauma was negative. Cocaine concentrations on the first incident peaked at 2.48 mg/L and on the second incident peaked at 3.9 mg/L. Other clinical findings included tachycardia, hypertension, diaphoresis, and disorientation. Blood cocaine and metabolite analysis revealed extremely high concentrations. Other than the incident of seizures and transient cardiovascular aberrations, these high concentrations were tolerated by the patient without further sequelae. A review of cocaine-induced seizures and treatment is included.

Adult↗
PubMed1996

Pediatric growth and development.

Most children with congenital anomalies, teratogenesis, inborn errors of metabolism, and acquired toxicity or injury will have abnormal growth and development during the first few years of life. Many of the conditions are treatable, and early intervention is associated with improved prognosis. Developmental and growth assessment should be part of any routine visit to a primary care clinician. An overview of normal growth and development is outlined, and some common abnormalities are discussed.

Child↗
PubMed1996

Pharmacological considerations for the pediatric patient.

The use of pharmacological agents in children warrants special consideration because children have variable pharmacokinetic parameters. Not only are the pharmacokinetic properties of drugs different in children as compared with adults, but these properties can undergo rapid change as children grow and mature. Furthermore, many drugs that would be useful in the pediatric population lack the indication for use in children and, therefore, dosing guidelines are not available. This paper presents an overview of basic pharmacokinetics in children and pediatric dosing guidelines.

Absorption↗
PubMed1995

Determining the true cause of death in a dermatological disaster.

Adverse drug reactions that result in patient death warrant special consideration to determine if the outcome was preventable. We report the results of an investigation into the cause of death of a 63 year old male who was thought to have phenytoin-induced toxic epidermal necrolysis (TEN). Most dermatological reactions from drugs are minor and resolve without sequelae once the drug is discontinued. In some cases, reactions are severe and can be life threatening. The patient arrived at the emergency department with extensive exfolative dermatitis. The differential diagnosis included phenytoin-induced TEN, scalded skin syndrome, and phenytoin hypersensitivity. After he was admitted his clinical status deteriorated and he died 13 days after admission. Autopsy findings were significant for necrotizing dermatitis, necrotizing pneumonia, multiple herpetic ulcerations, multisystem organ failure and blood cultures grew Staphylococcus aureus (TSS toxin positive). Findings that indicate a cause of death other than a drug-induced dermatological reaction are presented as well as an overview of the patients' medical history. The differential diagnosis of drug induced skin lesions are also discussed.

Journal Article↗
PubMed1991

Lowering extracellular calcium decreases the length of isolated outer hair cells.

Transduction by the inner hair cells is hypothesized to be modulated through a change in the length of the outer hair cells (OHC). It has been suggested that the slow change occurring in OHC length is mediated by an actin-myosin system requiring Ca2+ and ATP. This study was designed to systematically examine the effects of lowering extracellular Ca2+ on OHC length. OHCs were isolated from guinea pig cochleae, mechanically dissociated and dispersed, and placed in a Hank's balanced salt solution (HBS). Exposing the cells to a Ca(2+)-free HBS supplemented with 200 microns EDTA produced a shortening in OHC length with a concomitant increase in cell width. The shortening was reversed successfully by bathing the cells in 8 mM Ca2+. We speculate that the decrease in length due to lowering extracellular Ca2+ may be caused by a relaxation of a circumferential contractile mechanism which is thought to cause elongation of intact OHCs (Slepecky, 1989; Dulon et al., 1990).

Animals↗
PubMed1986

Comparative actions of quisqualate and N-methyl-D-aspartate, excitatory amino acid agonists, on guinea-pig cochlear potentials.

We examined dose-dependent changes in the amplitude of guinea-pig cochlear microphonic potentials (CM), summating potentials (SP) and compound auditory nerve action potentials (CAP) produced after perfusing perilymphatic scalae with artificial perilymph containing either the transmitter candidate, L-glutamate; one of the excitatory amino acid agonists, quisqualate, kainate, N-methyl-D-aspartate (NMDA) or D-glutamate; or the control, alpha-ketoglutarate. None of these compounds significantly altered CM or SP. Kainate abolished CAP, but only partial suppression occurred using maximal effective doses of quisqualate (67%) or L-glutamate (82%). The remaining compounds had only marginal effects on CAP. The potency of quisqualate (EC50 = 14.8 microM) exceeded that of both kainate (EC50 = 66.9 microM) and L-glutamate (EC50 = 1.41 mM). These data suggest the presence of neuronal, possibly postsynaptic, excitatory amino acid receptor subpopulations which are preferentially sensitive to quisqualate and to kainate, but not to NMDA. These findings are discussed in the framework of our hypothesis that the proposed quisqualate and kainate receptors are normally activated by an endogenous excitatory amino acid such as L-glutamate which the hair cells release as a neurotransmitter.

Action Potentials↗
PubMed1985

Comparative actions of GABA and acetylcholine on the Xenopus laevis lateral line.

The effects of GABA, acetylcholine and carbachol on the spontaneous activity of afferent nerve fibers in the lateral line of Xenopus laevis are characterized. Atropine and bicuculline were also tested on drug- and water motion-evoked activity. GABA (0.019-1.25 mM) suppressed and both acetylcholine (1.25-80 microM) and carbachol (1.25-40 microM) increased spontaneous activity. These actions were blocked by bicuculline (100 microM) and atropine (4 microM) respectively. Atropine (20 microM) and bicuculline (100 microM) had no effect on water motion-evoked activity. The results characterize actions of GABA and acetylcholine not previously described and provide evidence that does not support the hypothesis that GABA or acetylcholine are the afferent transmitter.

Acetylcholine↗
PubMedDate not supplied

Clinical pharmacology of lysergic acid diethylamide: case reports and review of the treatment of intoxication.

Intoxication and overdose are common presenting complaints to the emergency department. Acute intoxication with lysergic acid diethylamide (LSD) has become a relatively rare event, especially when compared with the incidence of ethanol and cocaine intoxication. We recently had an outbreak of presumed LSD intoxications occurring over one weekend. All patients had attended a performance by the musical group The Grateful Dead. At present, LSD intoxication or overdose can only be suspected based on clinical findings because there are no readily available rapid laboratory tests for detecting either the parent compound or the metabolites of the drug. The clinical findings and outcomes of five patients with suspected LSD intoxication are presented. The pharmacological effects of LSD and treatment modalities of intoxication are reviewed. All patients were treated conservatively based on clinical signs and symptoms. Only one patient required hospital admission for combative behavior that was initially refractory to pharmacological restraint.

Adult↗