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Biomedical subjects

L A Broussard

Publications and source records attributed to L A Broussard.

13 recordsLinked to original sources
PubMed2001

Biological agents: weapons of warfare and bioterrorism.

The use of microorganisms as agents of biological warfare is considered inevitable for several reasons, including ease of production and dispersion, delayed onset, ability to cause high rates of morbidity and mortality, and difficulty in diagnosis. Biological agents that have been identified as posing the greatest threat are variola major (smallpox), Bacillus anthracis (anthrax), Yersinia pestis (plague), Clostridium botulinum toxin (botulism), Francisella tularensis (tularaemia), filoviruses (Ebola hemorrrhagic fever and Marburg hemorrhagic fever), and arenaviruses Lassa (Lassa fever) and Junin (Argentine hemorrhagic fever). The pathogenesis, clinical manifestations, diagnosis, and treatment of these agents are discussed. Rapid identification and diagnosis using molecular diagnostic techniques such as PCR is an essential element in the establishment of coordinated laboratory response systems and is the focus of current research and development. Molecular techniques for detection and identification of these organisms are reviewed.

Animals↗
PubMed2001

Headspace gas chromatographic method for the measurement of difluoroethane in blood.

OBJECTIVES: To develop a gas chromatographic assay for the analysis of difluoroethane, a volatile substance, in blood and to determine assay characteristics including linearity, limit of quantitation, precision, and specificity. SETTING: Referral toxicology laboratory RESULTS: Difluoroethane, a colorless, odorless, highly flammable gas used as a refrigerant blend component and aerosol propellant, may be abused via inhalation. A headspace gas chromatographic procedure for the identification and quantitation of difluoroethane in blood is presented. A methanolic stock standard prepared from pure gaseous difluoroethane was used to prepare whole blood calibrators. Quantitation of difluoroethane was performed using a six-point calibration curve and an internal standard of 1-propanol. The assay is linear from 0 to 115 mg/L including a low calibrator at 4 mg/L, the limit of quantitation. Within-run coefficients of variation at mean concentrations of 13.8 mg/L and 38.5 mg/L were 5.8% and 6.8% respectively. Between-run coefficients of variation at mean concentrations of 15.9 mg/L and 45.7 mg/L were 13.4% and 9.8% respectively. Several volatile substances were tested as potential interfering compounds with propane having a retention time identical to that of difluoroethane. CONCLUSIONS: This method requires minimal sample preparation, is rapid and reproducible, can be modified for the quantitation of other volatiles, and could be automated using an automatic sampler/injector system.

Administration, Inhalation↗
PubMed2000

Death due to inhalation of ethyl chloride.

A 30-year-old white male was found dead in a locked apartment with a rag held loosely in his mouth. Four cans (3 empty, 1 partially empty) containing ethyl chloride and labeled as VCR head cleaner were found next to the body. Phenylpropanolamine and low therapeutic levels of diazepam (64 microg/L) and nordiazepam (126 microg/L) were detected during toxicological analysis. An unidentified peak was observed when performing ethanol analysis by headspace gas chromatography. The peak was identified as ethyl chloride and the concentrations in the blood, urine, vitreous, brain, and lungs of the deceased were 423 mg/L, 35 mg/L, 12 mg/L, 858 mg/kg, and 86 mg/kg, respectively. The results were compared with previously reported levels of ethyl chloride in blood and vitreous and, based on a literature search, we believe that this is the first report of ethyl chloride levels in tissue.

Administration, Inhalation↗
PubMed2000

The role of the laboratory in detecting inhalant abuse.

OBJECTIVE: To provide an overview of inhalant abuse including the extent of the problem, types of products abused, modes and signs of abuse, pharmacology and effects of volatile substances, the role of the laboratory, and interpretation of laboratory results.

Administration, Inhalation↗
PubMed1997

Simultaneous identification and quantitation of codeine, morphine, hydrocodone, and hydromorphone in urine as trimethylsilyl and oxime derivatives by gas chromatography-mass spectrometry.

Following enzymatic hydrolysis of urine, a gas chromatography-mass spectrometry method for the simultaneous determination of codeine, morphine, hydrocodone, and hydromorphone uses hydroxylamine to form oxime derivatives of the keto-opiates (i.e., hydrocodone, hydromorphone, oxycodone, and oxymorphone). These trimethylsilyl-derivatized forms no longer interfere with the detection and quantitation of codeine and morphine. Samples are extracted on solid-phase columns and quantitated by deuterated internal calibrations of each analyte with selected ion monitoring. Codeine, morphine, hydrocodone, and hydromorphone are completely separated, allowing simultaneous quantitation without interference and a chromatographic analysis time < 9 min.

Codeine↗
PubMed1997

Two traffic fatalities related to the use of difluoroethane.

The 18-year-old white male driver and 17-year-old white male passenger of an automobile were killed when their vehicle crossed the median of a 4-lane highway and collided with a minivan. A can of airbrush propellant was found in the automobile of the deceased. The only drug detected during initial toxicological analyses was 130 mg/L ethanol in the blood of the driver. When performing ethanol analysis by headspace gas chromatography, an unidentified peak was observed in the blood of both deceased. This peak was identified as difuoroethane (Freon 152), the propellant in the aerosol can found in the automobile. The concentrations of difluoroethane in the blood of the driver and passenger were 78 mg/L and 35 mg/L, respectively. Based on a literature search we believe that this is the first report of the quantitation of difluoroethane in biological samples.

Accidents, Traffic↗
PubMed1979

Quantitative high-performance liquid-chromatographic method for determining disopyramide (Norpace) in serum.

We report a high-performance liquid-chromatographic method for measuring disopyramide (Norpace, Searle) in serum. The drug is extracted from 0.5 ml of serum into chloroform containing the internal standard p-chlorodisopyramide, separated on a reversed-phase octadecylsilyl column at room temperature, and detected at 254 nm. The method is sensitive to 0.2 mg of disopyramide per liter, with a linear response to at least 10 mg/liter. Within-day precision (CV) for frozen serum pools is 8.3 (n = 21) and (n = 22) at mean concentrations of 2.6 and 5.9 mg/liter, respectively. Day-to-day precision (CV) is 9.4 (n = 80) and 9.3 (n = 29) at mean concentrations of 2.8 and 6.7 mg/liter, respectively. Recoveries for disopyramide in serum averaged 98% over the linear range when compared against an aqueous standard taken through the entire analytical procedure. The method is relatively specific, as evidenced by interference studies with over 85 drugs.

Chromatography, High Pressure Liquid↗
PubMed1979

Calibration and monitoring of spectrometers and spectrophotometers.

We have delineated some of the factors affecting the performance of spectrometers and spectrophotometers in the clinical laboratory and have presented some of the methods for verifying that these instruments are functioning properly. At a minimum, every laboratory should perform periodic inspections of spectrometric functions to check wavelength calibration, linearity of detector response, and stray radiation. Only through such an inspection program can a laboratory ensure that these instruments are not contributing to inaccurate analytical results.

Color↗
PubMedDate not supplied

Shots for tots: Louisiana's infant immunization initiative.

PURPOSE: To describe the "Shots for Tots" immunization initiative, a community-based approach to overcoming barriers to timely immunizations. POPULATION: Children in southwest Louisiana, ages 1 month to 5 years, requiring immunizations. CONCLUSIONS: The "Shots for Tots" immunization initiative has been successful in improving immunization rates. PRACTICE IMPLICATIONS: With the increase in community-based practice and the resurgence of many vaccine-preventable diseases, this program can serve as an example to pediatric nurses involved in prevention and primary care in their efforts to improve immunization rates.

Child, Preschool↗
PubMedDate not supplied

Evaluation of DRI enzyme immunoassays for drugs-of-abuse screening on the Cobas Mira.

OBJECTIVE: To establish optimal performance parameters (ratios of sample and reagents, reaction time, and distinction of absorbance values between calibrators) on the Roche Cobas Mira analyzer for the evaluation of Diagnostic Reagents Inc enzyme immunoassay reagents for urine screening of amphetamines, cannabinoids, cocaine metabolite, opiates, and phencyclidine. SETTING: Laboratory in a physician's office. PRACTICE DESCRIPTION: Two laboratorians analyze a daily average of 25 urine samples for employment screening purposes. PRODUCT COMPARISON: DRI reagents were compared to Syva EMIT reagents. RESULTS: Within-run and between-run precision at the cutoff concentration for DRI reagents ranged from 1.1% to 1.6% CV and 2.2% to 5.7% CV respectively. Results (positive or negative) using DRI or Syva EMIT reagents were identical for cannabinoids, cocaine metabolite, opiates and PCP. Direct comparison for amphetamines was not possible because of different cutoff concentrations of the 2 reagents systems. CONCLUSION: DRI reagents are acceptable alternatives to EMIT reagents for the analysis of amphetamines, cannabinoids, cocaine metabolite, opiates and phencyclidine in urine on the Cobas Mira analyzer. Utilization of DRI reagents for more than 12 months demonstrated the reliability of the reagents and allowed cost comparison. ABBREVIATIONS: DRI = Diagnostic Reagents Inc; EMIT = enzyme multiplied immunoassay technique; d.a.u. = drugs of abuse; PCP = phencyclidine; GC/MS = gas chromatography/mass spectrometry.

Enzyme Multiplied Immunoassay Technique↗