Biomedical subjects

S Inbar

Publications and source records attributed to S Inbar.

4 recordsLinked to original sources

PubMed1992

Comparison of the effects of adenosine and nifedipine in pulmonary hypertension.

The hemodynamic effects of intravenously administered adenosine, a potent vasodilator, were examined in 15 patients with pulmonary hypertension. All patients were given adenosine, 50 micrograms/kg per min, increased by 50 micrograms/kg per min at 2 min intervals to a maximum of 500 micrograms/kg per min or until the development of untoward side effects. The patients were then given oral nifedipine, 20 mg every hour, until a greater than or equal to 20% decrease in pulmonary vascular resistance or systemic hypotension occurred. The administration of maximal doses of adenosine, 256 +/- 46 micrograms/kg per min, produced a 2.4% reduction in pulmonary artery pressure (p = NS), a 37% decrease in pulmonary vascular resistance (p less than 0.001) and a 57% increase in cardiac index (p less than 0.001). The administration of maximally effective doses of nifedipine (91 +/- 36 mg) produced a 15% reduction in the mean pulmonary artery pressure (p less than 0.05), a 24% decrease in pulmonary vascular resistance (p less than 0.01) and an 8% increase in cardiac index (p = NS). There was a significant correlation (r = 0.714, p = 0.01) between the reduction in pulmonary vascular resistance that resulted from adenosine administration and that achieved with the administration of nifedipine. Six patients had substantial reductions in pulmonary vascular resistance with adenosine but not with nifedipine. Thus, adenosine is an effective vasodilator in patients with pulmonary hypertension and can be used for safe and rapid assessment of vasodilator reserve in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗

PubMed1990

Dry chemistry thin film immunoassay.

The authors report the development of a novel thin film multilayer immunoassay technology. The technology is applied to therapeutic drug monitoring and thyroid hormone testing in serum or plasma and can be extended to assays of other low molecular weight analytes. The assay detection range spans five orders of magnitude, from 1 x 10(-3) to 1 x 10(-8) M. The assay element comprises of multilayer coated chip, containing the active reagents in an agarose matrix and a plastic module serving both as a holder and a spreader. The assays are in the fluorescent competitive immunoassay format of the ligand displacement mode and are performed on an automated instrument with random access capability. The assays are fast and reliable and gave very good agreement when compared to reference methods.

Immunoassay↗

PubMed1990

Development of monoclonal antibodies for therapeutic drug monitoring.

For the development of multilayer fluorescent immunoassays to determine directly a variety of therapeutic drugs high specific monoclonal antibodies against the anticonvulsants carbamazepine, phenobarbital, phenytoin and valproic acid have been prepared. For each antibody a standard curve could be established showing good linearity and a suitable sensitivity scope. To validate the eligibility of the desired antibodies a variety of drugs and metabolites sharing structural similarities to the individual drugs were tested for their cross-reactivity. It could be shown that only a few very closely related compounds exhibited substantial cross-reactivity. These monoclonal antibodies are therefore assumed to be suitable for a TDM-assay development.

Antibodies, Monoclonal↗

PubMed1989

Multilayer fluorescent immunoassay technique.

We describe a new multilayer immunoassay element for the determination of haptens in undiluted serum and plasma. Polysaccharide layers are coated onto a plastic base. The signal layer contains an immobilized antibody and a fluorescent-labeled hapten. A second layer, containing a pigment, acts as an optical screen. Sample spreading is achieved by a molded grid in contact with the upper layer of the immunoassay element. After sample is added to the element, endogenous analyte competes with the labeled hapten for the binding sites of the immobilized antibody; equilibrium is reached in 4-12 min. Because of the relative liquid-holding capacities of the layers and the grid, only a small amount of the free components remains in the signal layer. The signal is measured by front-surface fluorimetry. This technology has been applied to theophylline and thyroxin assays. Within- and between-run CVs range from 3% to 6%. Comparisons with fluorescent polarization immunoassays (Abbott TDx) showed excellent correlation (theophylline: r = 0.98, slope = 1.07, intercept = 0.3; thyroxin: r = 0.97, slope = 0.91, intercept = 0.8). The new method requires only one pipetting step (sample delivery) and is potentially applicable to a wide range of analytes.

Fluorescence Polarization↗