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Biomedical subjects

J Brent

Publications and source records attributed to J Brent.

41 records · Page 3Linked to original sources

Reversal of prolonged isoniazid-induced coma by pyridoxine.

Isoniazid overdose is known to result in the rapid onset of seizures, metabolic acidosis, and prolonged obtundation. Pyridoxine has been reported to be effective in treating isoniazid-induced seizures. We report three cases of obtundation secondary to isoniazid overdose that was immediately reversed by intravenous pyridoxine. In two of these cases, status seizures were stopped by intravenous pyridoxine administration, but the patients remained comatose for prolonged periods. The comas were immediately reversed by the administration of additional pyridoxine. In the third case, the patient's lethargy was treated by intravenous pyridoxine on presentation and was followed by immediate awakening. Pyridoxine is effective in treating not only isoniazid-induced seizures, but also the mental status changes associated with this overdose. The dose required to induce awakening may be higher than that required to control seizures.

Adolescent↗

Lymphocyte defect in plasmacytoma-bearing mice.

Multiple myeloma is often associated with humoral immunodepression in both man and mouse. When mice bearing the humorally immunodepressive plasmacytomas TEPC-183 and SPQC-11 were injected with SRBC, the rise of serum haemolysins was significantly less than that of non-tumour-bearing mice. Mice with the plasmacytomas MPC-11 and MOPC-315 have an antibody response similar to normal mice when injected with SRBC. Following immunization, normal mice and those bearing MPC-11 showed a 2- to 3-fold increase in total spleen lymphocytes. Mice bearing TEPC-183 or SPQC-11, the plasmacytomas causing an impaired antibody response, has significant increase in spleen lymphocytes under the same conditions. Mice bearing MOPC-315 had a very high initial count of spleen lymphocytes, which did not further increase upon immune stimulation.Incubation of lymphocytes from plasmacytoma-bearing mice with PHA did not produce an increase in TdR incorporation and in some cases even caused a decrease in TdR incorporation.Lymphocytes from mice bearing TEPC-183, SPQC-11, and MOPC-315 incorporated less TdR in response to LPS than did normal mice. On the other hand, mice bearing MPC-11 incorporated about as much TdR as did normal mice following LPS stimulation. Thus, the defect in the ability to respond to LPS in vitro correlated with the lack of an increase of spleen lymphocytes in mice bearing these tumours following antigenic stimulation in vivo.No immunodepressive properties of serum from mice with plasmacytoma could be detected.

Animals↗

Cocaine adsorption to activated charcoal in vitro.

Although activated charcoal (AC) is commonly used after ingestions of cocaine, the ability of AC to bind with this drug is unknown. We studied binding of cocaine to AC in vitro. Cocaine adsorption to charcoal for AC:drug ratios of 1:1, 2.5:1, and 5:1 at pH 1.2 was 40%, 92%, and 99%, respectively; at pH 8.0, it was 78%, 98%, and 99%, respectively. All means were significantly different (P less than 0.05) versus the control (no AC) at each pH. At the AC:drug ratio of 1:1, there was also significantly greater adsorption of cocaine at pH 8.0 than at pH 1.2. This study shows that AC strongly adsorbs cocaine under both acidic and alkaline conditions.

Adsorption↗

Fluoxetine versus tricyclic antidepressants: a prospective multicenter study of antidepressant drug overdoses. The Antidepressant Study Group.

This study compares the clinical course of tricyclic antidepressant and fluoxetine overdose. The study was a prospective case series of 9 urban hospital systems. Consecutive sampling of overdose patients presenting to emergency departments provided the participants for the study. The therapy was determined by each institution. Clinical, laboratory, economic impact, and coroners' information was gathered. Of 622 patients, 482 were excluded because of significant coingestants or lack of laboratory confirmation, leaving 124 tricyclic antidepressant and 16 fluoxetine cases. Twenty-seven percent of tricyclic antidepressant patients were alert on arrival to the emergency department; only 12.9% remained alert. The following were significantly more frequent after tricyclic antidepressant overdose: agitation, tachycardia, QRS prolongation, terminal R-wave deviation, intubation, coma, and admission to the intensive care unit. The mean tricyclic plus metabolite level was 777.6 ng/mL (range = 20-5260 ng/ mL), and the mean fluoxetine plus metabolite level was 496.4 ng/mL (range = 120-1930 ng/mL). There were two tricyclic antidepressant deaths. Of 179 total drug-ingestion deaths from the coroners' records, 38 were from tricyclic antidepressants and none from fluoxetine. Thus, tricyclic antidepressant overdoses resulted in more toxicity and more frequent admissions to the intensive care unit than did fluoxetine overdoses.

Adolescent↗