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Biomedical subjects

A M Herrera

Publications and source records attributed to A M Herrera.

5 recordsLinked to original sources
PubMed1990

Microdialysis sampling for determination of plasma protein binding of drugs.

The use of microdialysis sampling to study the binding of drugs to plasma proteins was evaluated. Microdialysis sampling is accomplished by placing a short length of dialysis fiber in the sample and perfusing the fiber with a vehicle. Small molecules in the sample, such as drugs, diffuse into the fiber and are transported to collection vials for analysis. Larger molecules, such as proteins and protein-bound drugs are excluded by the dialysis membrane. Microdialysis was found to give values for in vitro protein binding in plasma equivalent to those determined by ultrafiltration. Microdialysis offers advantages in terms of maintaining equilibria and experimental versatility. Microdialysis sampling also provides potential use for in vivo determinations of protein binding.

Blood Proteins↗
PubMed1990

Sinusitis. Its association with asthma.

Sinusitis may present as an indolent infection, without the classic symptoms and signs commonly expected, and will probably be missed in children who have only cough and persistent rhinorrhea unless this diagnosis is kept in mind. Plain radiography is the most commonly used diagnostic procedure for sinusitis, but computed tomography may be more sensitive. The contribution of sinusitis to the induction and exacerbation of asthma is still unresolved. The existence of a nasobronchial reflex is not clearly supported by available data, although it is a likely explanation for the observed relationship between the two processes. However, sinusitis appears to be an important underlying trigger for some cases of asthma and, therefore, should be suspected any time that acute or chronic asthma is difficult to control.

Adult↗
PubMed1989

Immunoglobulin composition of three commercially available intravenous immunoglobulin preparations.

To evaluate whether significant differences in immunoglobulin composition exist among the three commercially available intravenous immunoglobulin (IVIG) preparations, we compared three of these products in terms of their quantitative immunoglobulin concentration, IgG subclass concentration, and the presence of IgG aggregates. Three different lots were tested for each of the IVIG formulations, and the IgG subclass assays were performed by three different laboratories. Differences were found among the three formulations in subclass concentration and aggregate content. Sandoglobulin (Sandoz Pharmaceuticals, East Hanover, N.J.) contained a significantly higher amount of IgG2 (p less than 0.002) compared to the other formulations. All the formulations tested were found to be deficient in IgG4 relative to the World Health Organization standards, with Gammagard (Hyland Therapeutics, Glendale, Calif.) demonstrating only negligible amounts. Immunoglobulin aggregate content was different among manufacturers with Gamimmune N (Cutter Biological, Berkeley, Calif.) containing the highest amount of monomer IgG (99.8%). Significant differences were found in the subclass results obtained by the ICN ImmunoBiologicals assay (Lisle, Ill.), compared to the two reference laboratories. This difference among the subclass assays raises the question as to the use of these assays in the evaluation of patients with suspected subclass deficiencies. The differences in subclass concentration and aggregate content in IVIG preparations were great, and future clinical trials with these formulations would be indicated to determine the clinical significance of these findings.

Chromatography, High Pressure Liquid↗