Biomedical subjects

M Hammarstrom

Publications and source records attributed to M Hammarstrom.

5 recordsLinked to original sources

PubMed2002

Does nitric oxide act as a cellular messenger in muscarinic endometrial secretion in the guinea-pig?

Uterine secretory cells receive a sympathetic cholinergic secremotor innervation. Nitric oxide (NO) has been suggested to be a second messenger of neurogenic modulated glandular secretion of the seminal vesicle. Thus a similar pattern for nervous induced carbohydrate secretion of the endometrium was assumed. The nitric oxide synthase (NOS) activity was estimated via formation of L-citrulline from L-arginine and histochemically with the nicotinamide-adenine dinucleotide phosphate diaphorase (NADPH-d) nitro blue technique. The carbohydrate secretion from everted uterine horns placed in organ baths was estimated. A calcium dependent formation of citrulline was found in the uterine horn suggesting an NOS activity. Strong NADPH staining cells were found in the glandular ducts of the endometrium and in the epithelial linings of the oviduct. Carbachol induced carbohydrate secretion of the endometrium while N-nitro L-arginin (L-NNA) and N-nitro L-arginin methyl ester (L-NAME) inhibited the carbachol induced secretion. The isomer D-NAME had no effect on carbachol induced secretion. When L-arginine was administered together with L-NNA no inhibitory effect on carbachol induced secretion was seen. L-arginine only had no effect on carbohydrate secretion. The NO donor glyceryl tritrate increased carbohydrate secretion but no synergistic effect was seen in combination with carbachol. The results suggest that glandular NO production is a prerequisite for muscarinic carbohydrate secretion of the endometrium.

Animals↗

PubMed1990

Predictive value of lipoprotein (a) and other serum lipoproteins in the angiographic diagnosis of coronary artery disease.

To determine the relation among lipids in predicting coronary artery disease (CAD), 213 patients undergoing diagnostic angiography for suspected CAD were prospectively studied. Twenty-one patients had normal coronary arteries and 192 had CAD in 1 to 3 arteries at arteriography with measurements obtained with digital calipers. Lipoproteins were measured and lipoprotein (a) [Lp(a)] was also assayed in a subset of 98 patients with CAD. Statistical analysis was performed using uni- and multivariate techniques to test the association among age, gender, systemic hypertension, diabetes mellitus, cigarette smoking, family history, total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, very low density lipoprotein cholesterol, apolipoproteins (apo) A-I and apo B, ratio of apo A-I to apo B, and ratio of HDL cholesterol to total cholesterol, to Lp(a) and to CAD. All factors except gender, systemic hypertension, diabetes mellitus and cigarette smoking were univariate predictors of CAD. Multivariate predictors were, in decreasing order of significance, family history, age, HDL/total cholesterol ratio and apo B. When Lp(a) was included, multivariate predictors were age, family history, apo B and Lp(a), in that order. Lipid parameters alone showed that the HDL/total cholesterol ratio and that Lp(a) provide the best predictive tests for the detection of CAD in this referral population and may ultimately become important screening tests for CAD.

Coronary Angiography↗

PubMed1989

Comparison of specific radioimmunoassays for cyclosporine.

This study compares two recently introduced radioimmunoassay kits involving specific monoclonal antibodies to cyclosporine. One kit (Sandimmun) involved 3H-labeled CsA (3H-CsA) as tracer and the other (CY-CLO-Trac-SP) involved a 125I-labeled conjugated derivative of CsA. The kits were nearly equivalent in method performance characteristics. They produced superimposed standard curves and equivalent values to transplanted patient samples. Concentrations of CsA determined by either kit were apparently equivalent to values measured by high-performance liquid chromatography, suggesting that the specific monoclonal antibodies used with the kits detect in trough blood mainly native CsA. The 125I-labeled CsA, when compared with the 3H-CsA alternative, increased the sensitivity and precision, decreased the turnaround time, and provided a technically efficient and conveniently capable method of replacing HPLC for measuring native CsA.

Antibodies, Monoclonal↗

PubMed1989

Four sensitive thyrotropin assays critically evaluated and compared.

We compared four sensitive procedures for thyrotropin (TSH)--Corning's Magic-Lite, ElectroNucleonics' Delfia, Baxter's Stratus, Nichols' Allegro--for their ability to completely discriminate TSH concentrations in sera in euthyroidism, hyperthyroidism, and hypothyroidism. We evaluated the analytical and clinical performance of these procedures according to previously published criteria. All procedures we examined fulfilled the criterion stipulating less than 1% overlap between the assay variation at the lower normal range limit and the assay sensitivity. Both measurements were made with an interassay CV not exceeding 10% to 15%. All procedures produced results that correlated well for specimens with TSH concentrations of greater than 0.4 milli-int. unit/L, and all four procedures clearly distinguished hypothyroid from euthyroid subjects. In a hyperthyroid-euthyroid comparison, three of the procedures, the Magic-Lite, Delfia, and Allegro, differentiated the two with 97% accuracy, the Stratus procedure with only 90% accuracy. The procedures appeared to differ even more in the measurement of TSH in serum of patients undergoing suppressive treatment with thyroid hormones and in hospitalized nonthyroidally ill patients. The observed differences among procedures were thought to be related in part to a matrix serum effect, which is accentuated in samples from hospitalized patients.

Evaluation Studies as Topic↗

PubMed1983

Effect of Fluosol-DA on radioimmunoassay results.

Fluosol-DA, an emulsion of perfluorocarbons, is used as a blood substitute. Its presence in samples affects results of certain radioimmunoassays routinely done in our laboratory. In several, added Fluosol-DA caused an upward displacement of the standard curve, the extent of which depended on the structure and quantity of the assayed antigen, the concentration of Fluosol-DA, and the nature of the immunoreagents. Fluosol-DA markedly affected results of assays for triiodothyronine, thyroxin, and digoxin (by one method), but assays for aminoglycosides and protein hormones were unaffected. We determined that Fluosol-DA interacts with unbound labeled (and, presumably, with unlabeled) antigen to form a complex that coprecipitates with the bound antigen-antibody fraction during the separation step. In comparison with the idealized condition we observed an apparent increase in antibody-bound labeled antigen and consequently an apparent underestimation of the measured antigen. Depending on the nature of the immunoreagents, antibodies can extract more or less of their respective antigens from particles of Fluosol-DA emulsion.

Antigen-Antibody Complex↗