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Biomedical subjects

K R Labrosse

Publications and source records attributed to K R Labrosse.

6 recordsLinked to original sources
PubMed1988

Reliability of antidepressant assays: a reference laboratory perspective on antidepressant monitoring.

Chromatography (gas and liquid) and immunoassays are used for monitoring the commonly prescribed tricyclic antidepressants. Many commercially available immunoassays are known to cross react with structurally similar compounds. Chromatographic methods make it possible simultaneously to resolve and quantify amitriptyline, nortriptyline, imipramine, desipramine, trimipramine, doxepin, desmethyldoxepin, protriptyline, and maprotiline-and potentially crossreactive compounds can be separated from the tricyclics. Immunoassays may have a valuable role in initial toxicological screening for the presence of a tricyclic-like compound, and they also may be helpful in a laboratory dedicated to a well-controlled patient group. However, 10% of our specimens contain more or different antidepressants than we are requested to analyze for. With our analysis, we are able to report which antidepressants are present, and in what concentrations. Further, in the case of a potential overdose of tricyclic, the primary purpose for early toxicological analysis to anticipate subsequent clinical complications. Therefore, even in the case of toxicological analysis, it is important to know exactly what tricyclic antidepressant is present rather than just the semiquantitative presence of one or more structurally related compounds, because these various compounds differ markedly in their potential for adverse effects. There are too many potential, and possibly yet unknown, interactions for a reference laboratory routinely to rely on immunoassays for therapeutic drug monitoring or toxicological identification of antidepressants.

Antidepressive Agents, Tricyclic↗
PubMed1986

Is serum creatine kinase-MB in electrically injured patients predictive of myocardial injury?

We undertook a retrospective study of 36 victims of high-voltage electrical contact injuries to determine the incidence and possible source of elevated creatine kinase (CK)-MB enzyme in their serum. Only two sustained myocardial infarctions (one late) according to history, electrocardiographic findings, and clinical course. Serum lactate dehydrogenase isoenzyme levels were abnormal but revealed no myocardial infarction patterns. Creatine kinase total activity, however, reached 1.5 to 1,140 times normal in 92% and the CK-MB level was abnormal in 50% despite the low incidence of myocardial damage. Skeletal muscle CK and CK-MB levels in four nonelectrically injured patients were comparable to those in normal muscle while CK and CK-MB activity was elevated in six such electrical injuries. There was a gradient in CK-MB activity with greatest CK-MB activity in "normal" muscle near the injury site, lesser amounts in border tissue, and least in the worst-injured site. We conclude that myocardial injury is uncommon in high-voltage electrical injury and skeletal muscle injured by high electrical voltage is stimulated to produce, as well as release, CK-MB.

Adolescent↗
PubMed1986

Circadian rhythm in mammary cytoplasmic estrogen receptor content of Balb/C female mice with and without pituitary isografts.

Cytoplasmic estrogen receptors were determined by the dextran-coated charcoal method in inguinal breast tissue of three groups of Balb/C female mice 6-8 weeks following subcutaneous implantation into the intact animals of three pituitary glands and three pieces of skeletal muscle (group I), three pituitary glands and three segments of hypothalamic tissue (group II), or three pieces of skeletal muscle (group III) obtained from animals of the same inbred strain as control. A circadian rhythm in estrogen receptor content was statistically quantified by cosinor analysis in the muscle implanted control and the pituitary and hypothalamic implant groups. In the pituitary and muscle implant group the circadian rhythm is of borderline significance with a P-value between 0.05 and 0.10. The timing (acrophase) and extent of change (amplitude) are similar in all three treatment groups. The average receptor content (MESOR) in the two pituitary-implanted groups, which in previous studies were shown to have an increased breast cancer incidence is about twice that of the control group. The reduction in the pituitary induced breast cancer rate by hypothalamic tissue addition to a cancer incidence between the animals with pituitary and muscle isograft and the mice carrying no pituitary at all has also been shown previously in this strain of mice and is not reflected in receptor content.

Animals↗
PubMed1981

Free thyroxine levels in critically ill patients. A comparison of currently available assays.

Two indices of free thyroxine (T4) and four methods of free T4 measurement were compared in 85 patients with acute illness, hospitalized in intensive care units. All of the methods of free T4 measurement in critical illness were nonspecific, and two of the methods failed to suggest hypothyroidism in two patients with primary hypothyroidism and another associated critical illness. Since the ideal screening test should be both sensitive and specific, all tests for free T4 used in this study should be interpreted with caution in severely ill patients.

Acute Disease↗