Biomedical subjects

J J Saady

Publications and source records attributed to J J Saady.

11 recordsLinked to original sources

PubMed1992

Postinjury scopolamine administration in experimental traumatic brain injury.

A single bolus dose of scopolamine (1.0 mg/kg) or saline (equal volume) was injected (i.p.) at 15, 30 or 60 min after fluid percussion traumatic brain injury in the rat. Scopolamine administered at 15 min postinjury significantly reduced beam walking deficits and body weight loss assessed for 5 days after injury. Scopolamine treatment at 30 or 60 min postinjury had no effect on behavioral outcome assessed for 5 days after injury. Plasma concentrations of scopolamine were measured with a radioreceptor assay. The plasma half-life for scopolamine was 21.6 min in injured rats and 17.3 min in normal rats (P less than 0.05). These results, along with evidence from previous studies, suggest that a brief period of excessive neuronal excitation can produce relatively long-lasting behavioral deficits. The temporal effectiveness of receptor antagonist intervention in this process appears to be brief.

Animals↗

PubMed1991

Evidence for arsenic as the immunosuppressive component of gallium arsenide.

Gallium arsenide (GaAs) has been shown previously to suppress the in vivo antibody-forming cell (AFC) response to sheep erythrocytes (SRBC) when administered intratracheally at concentrations between 50 and 200 mg/kg. In the present studies, direct addition of GaAs to in vitro-generated antibody cultures resulted in dose-dependent suppression of the primary antibody response, and was only seen when GaAs was added within 36 hr following immunization. Using atomic absorption spectrophotometry on tissue samples from mice exposed to 200 mg/kg GaAs, arsenic concentrations were found to peak in the spleen at 24 hr and decline, whereas gallium concentrations continue to rise through 14 days. Concentrations of each metal in the spleen at 24 hr are comparable to the concentrations achieved for each metal when GaAs is added at 25 microM to the in vitro model system. The 24 hr time point was chosen for comparison because all in vivo-in vitro studies were conducted using spleens from mice 24 hr after GaAs exposure. NaAsO2 and Ga(NO3)3 suppressed the AFC response dose-dependently, and in a time-dependent manner similar to GaAs when added to the in vitro system. However, based on IC50 values for each salt, the role of the gallium component in the immunosuppression appears weak. Oxalic acid (OA) and meso-2,3-dimercaptosuccinic acid (DMSA), chelators of gallium and arsenic respectively, were added to cultures with GaAs to confirm that arsenic was the primary immunosuppressive component. DMSA dose-dependently blocked GaAs-induced immunosuppression in vitro, while OA had no effect. The metal-binding compounds were determined to be specific for the metals used in these studies and did not cross-react with one another. DMSA was evaluated for its ability to prevent suppression of the AFC response in splenocytes from GaAs-exposed mice and was able to block GaAs-induced suppression of the AFC response when given sc every 4 hr beginning 1 hr prior to GaAs exposure. These data indicate that the arsenic component of GaAs is the major contributor to the GaAs-induced immunosuppression and that this effect occurs within the first 36 hr of the 5-day culture period in a concentration-dependent manner.

Animals↗

PubMed1990

Evaluation of the Abbott ADx total serum tricyclic immunoassay.

The ADx total serum tricyclic antidepressant (TCA) fluorescence polarization immunoassay (Abbott Diagnostics) for the semi-quantitation of imipramine or amitriptyline and their respective N-demethylated metabolites in cases of TCA overdose was evaluated. The assay is linear from 75-1000 ng/mL total TCA in serum, and flaggs as "HI" all results exceeding 300 ng/mL. The within and between run precision of the assay for patient serum containing imipramine or amitriptyline and their metabolites gave CV's of less than 5.5% and 8.9%, respectively. A good correlation between the results of patient serum containing imipramine and desipramine simultaneously analyzed by ADx and gas liquid chromatography (GC) was observed, r2 = 0.964, n = 32. Results of patient serum containing amitriptyline and nortriptyline or doxepin and desmethyldoxepin analyzed by ADx and GC or GC-mass spectrometry were not well correlated; r2 = 0.738, n = 44 and r2 = 0.695, n = 21, respectively. The assay consistently flagged as "HI" serum with total imipramine and desipramine concentrations above 300 ng/mL by GC, and serum with greater than 360 ng/mL of amitriptyline and nortriptyline by GC/MS. No significant cross-reactivity was observed for drugs other than the TCA.

Antidepressive Agents, Tricyclic↗

PubMed1990

Arsenic poisoning: acute or chronic? Suicide or murder?

The case of the death by arsenic poisoning of a 62-year-old white man is presented. One year prior to death, he developed intermittent bouts of severe gastroenteritis with vomiting and diarrhea, hyperpigmentation and keratosis of the skin, neutropenia, and Guillain-Barré-like neuropathy for which he was hospitalized several times. Urine test results 6 months prior to death indicating 36 mg/L arsenic were believed to be in error. At the patient's last admission, he appeared in the emergency room with severe gastroenteritis, hypotension, and dehydration. He died 3 days later. Antemortem as well as autopsy specimens revealed elevated arsenic concentrations. Arsenic micrograms/g analysis by neutron activation of hair pulled from the man's head revealed by centimeter segmental analysis proximal to distal: 226, 104, 28, 56, 41, 40, and 74. The wife of the decedent was charged with murder by arsenic poisoning of this, her fifth, husband. The defense alleged that the decedent had committed suicide. The judge awarded a directed verdict of "not guilty." Particulars of the medical, toxicological, and investigative findings are presented.

Acute Disease↗

PubMed1978

Lithium anyone?

Explore the source record for details and available documents.

Costs and Cost Analysis↗

PubMedDate not supplied

Urinary excretion of benzoylecgonine following ingestion of Health Inca Tea.

Four males ingested one cup of Health Inca Tea which contained 1.87 mg of cocaine. Urine specimens collected for 36 h post-ingestion were analyzed for benzoylecgonine (BE) by EMIT-d.a.u., TDx and gas chromatography/mass spectrometry (GC/MS). Positive immunoassay results were obtained for 21-26 h post tea ingestion. Discrepant immunoassay results occurred with only one specimen: EMIT positive; TDx negative, 0.25 mg/l; GC/MS, 0.273 mg/l. Quantitative TDx results were well correlated with GC/MS results, r2 = 0.963, n = 45. Maximum urinary BE concentrations ranged from 1.4-2.8 mg/l, occurring from 4-11 h, post ingestion. Total BE excretion in 36 h ranged from 1.05 to 1.45 mg, 59-90% of the ingested cocaine dose. Urinary excretion rate constant (Km) ranged from -0.073 to 0.111/h. Health Inca Tea ingestion should be considered when interpreting urinary BE concentrations.

Beverages↗

PubMedDate not supplied

Demonstration of physical dependence following chronic continuous methadone delivery via osmotic minipumps in pregnant rats.

The effects of a 14-day (gestation days 7-20) chronic methadone (6.3-9.0 mg/kg/day) infusion via osmotic minipumps were studied on the induction of physical dependence in both pregnant and nonpregnant female rats. Following continued methadone exposure, an acute injection of naloxone (2.0 mg/kg, SC) produced the following symptoms of withdrawal in both pregnant and nonpregnant methadone-exposed rats: increased frequency of head shakes, teeth-chattering and face-rubbing episodes, as well as the induction of burrowing, diarrhea, facial tremor, squeaking and vaginal sniffing. Increased fetal movement in the maternal abdomen was also observed in the pregnant rats. In the saline-exposed pregnant controls, naloxone failed to induce a significant effect. In addition, brain and plasma methadone levels during the various stages of pregnancy (gestation days 8-20) were determined. The methadone levels in plasma were initially variable (gestation days 8-12) but became more constant (approximately 50 ng/ml) from gestation day 14 to 20. Methadone brain levels also followed a similar pattern, except that the brain methadone content was at least 20-fold greater than plasma concentrations at any given time. Thus, relative to the high brain levels, the present data suggest that acute changes in methadone plasma concentration may not be a good index of pharmacological effect.

Animals↗

PubMedDate not supplied

A case of nonfatal sodium fluoride ingestion.

A nonfatal case of sodium fluoride ingestion is presented. The quantity of sodium fluoride ingested is unknown. Initial serum and urine samples were taken 24 h after ingestion and contained 3.4 and 21.3 mg/L fluoride, respectively. At that time the patient was essentially asymptomatic, but it is clear that he survived a plasma concentration greater than that usually considered lethal, 3 mg/L serum fluoride. The case illustrates the lack of correlation between plasma fluoride concentration and toxic effects and the importance of obtaining a history of fluoride ingestion.

Humans↗

PubMedDate not supplied

Determination of atropine in blood by gas chromatography/mass spectrometry.

A gas chromatographic/mass spectrometric (GC/MS) method for the rapid quantitation of atropine (AT) in blood is presented. A 2.0-mL blood specimen containing deuterated N-methyl-atropine as the internal standard was alkaline-hydrolyzed to convert atropine to tropine. The tropine was extracted by organic solvent which was evaporated to dryness. Tropine in the residue was derivatized with pentafluoropropionic anhydride (PFPA) to the PFPA-tropine ester which was chromatographed on a 25-m cross-linked methyl silicone capillary column with temperature programming at 100 degrees C initially and increased by 20 degrees C/min. The retention time of atropine was 1.7 min. The GC/MS was operated in the SIM mode and the mass fragments monitored were 124 and 287 for AT and 127 and 290 for the internal standard. The assay was linear from 10-300 ng/mL. Replicate analysis of blood specimens containing 200 ng/mL gave a CV = 6.5% (n = 10). Recovery of AT at 75 and 150 ng/mL was 69% (n = 10). The limit of quantitation of AT was 10 ng/mL. Scopolamine may be simultaneously extracted and identified; the retention time was 1.8 min with mass ions 81 and 138.

Atropine↗

PubMedDate not supplied

Estimation of the body burden of arsenic in a child fatally poisoned by arsenite weedkiller.

A three-year-old child died after ingestion of a mouthful of an estimated 44% sodium arsenite solution. Litigation was initiated based on the quality of emergency treatment at a rural hospital. An issue raised in litigation was whether the child could have survived if he had received an additional dose of BAL (dimercaprol). BAL had been sent for from a neighboring city and arrived approximately 2.0 h after admission. The first 50-mg dose of BAL could have combined with a maximum of 30 mg arsenic; a second dose could have brought the total of chelated arsenic to 60 mg. To determine the total body burden of arsenic in the child, multiple tissues were analyzed. The total body burden was estimated at 113 mg, with 100 mg of this total attributable to the ingested solution. The actual body burden after two doses of BAL therefore would have been at least 40 mg, a fatal level.

Arsenic↗

PubMedDate not supplied

Determination of chlorinated hydrocarbon pesticides by solid-phase extraction and capillary GC with electron capture detection.

Pesticides and their metabolites are extracted and concentrated from serum using C18 solid-phase extraction cartridges. The internal standard aldrin is added to 4 mL of serum or plasma, treated with 2 mL of methanol, and the resultant supernatant applied to the C18 cartridge. After several washes, pesticides are eluted from the column with isoctane and the eluate quantified with capillary gas chromatography using electron capture detection. Extraction efficiency is from 70 to 75% and the method detection limit ranges from 0.1-0.7 ng/mL depending on the analyte. Precision studies demonstrate that CVs range from 3.5 to 25.2%. Standard curves are linear to at least 7 ng/mL for lindane and chlordane isomers, heptachlor, heptachlor epoxide, oxychlordane, trans-nonachlor, dieldrin, dichlorodiphenyldichloroethylene (p,p'-DDE), dichlorodiphenyldichloroethane (p,p'-DDD), and dichlorodiphenyltrichloroethylene (p,p'-DDT).

Chromatography, Gas↗