ABSTRACT
There is a need for improvement of thyrotropin measurements in the clinical laboratory, specifically in the lower portion of the normal range. We cite realistic examples of incorrect, misleading data generated with many thyrotropin kits currently in use and propose a practical laboratory protocol to evaluate the performance of a procedure for determining thyrotropin. The protocol integrates medical physiology with analytical measurement.
Subject(s)
Thyroid Diseases/diagnosis , Thyrotropin/blood , Evaluation Studies as Topic , Humans , Reagent Kits, Diagnostic , Thyroid Diseases/bloodSubject(s)
Antibodies, Viral/analysis , Rubella/immunology , Female , Humans , Immunization , Pregnancy , RadioimmunoassayABSTRACT
High-pressure liquid chromatography was used with a 5-micron silica gel column to quantitate hexylresorcinol in a commercial antiseptic solution following extraction with methylene chloride. This method shows linearity to at least 0.025% hexylresorcinol. A mobile phase consisting of 63% heptane, 34% chloroform, and 5% methanol was used with a UV detector (254 nm) and a flow of 3 ml/min. No interfering substances were observed.
Subject(s)
Hexylresorcinol/analysis , Anti-Infective Agents, Local/analysis , Chromatography, High Pressure Liquid , Methods , Solutions/analysisABSTRACT
Quantitative analyses of both camphor and parachlorophenol in camphorated parachlorophenol by high-pressure liquid chromatography is described. A 5% solution of phenol in the mobile phase (heptane-chloroform 3:2) served as the internal standard; the assay involved addition of this phenol solution to the camphorated parachlorophenol, followed by further dilution using the mobile phase (heptane-chloroform, 3:2) and injection into the instrument.
Subject(s)
Camphor/analysis , Chlorophenols/analysis , Chromatography, High Pressure Liquid , Drug Combinations/analysis , Solutions/analysisABSTRACT
High-pressure liquid chromatography was used with a 5-micrometer silica gel column to quantitate the phenol in phenolated calamine lotion USP and a commercial antiseptic solution. This method requires less than 10 min/assay, and other compounds present in the products analyzed did not interfere.
Subject(s)
Phenols/analysis , Anti-Infective Agents, Local/analysis , Antipruritics/analysis , Chromatography, High Pressure Liquid , Drug Combinations , Methods , Solutions/analysisABSTRACT
Fourteen 8-hydroxyquinolines were tested for antiplaque activity by measuring their minimum inhibitory concentrations [MIC (M)] against Streptococcus mutans No. 6715. Linear regression analysis was conducted with the MIC (M) values and hydrophobic (log P), electronic (beta, pKaOH, pKaN), and steric [molar refractivity (MR), molecular weight (mol wt)] parameters. The best correlation (r2 = 0.90) was obtained with MR, log P, and beta. The smaller the steric contribution of the 5-substituent, the more active the compound. The parent 8-hydroxyquinoline was the most active. The negative contribution toward activity by 5-substituents larger than hydrogen can be overcome by the positive contributions of groups that are lipophilic and electron withdrawing; for example, the 5-chloro derivative is as active as the parent 8-hydroxyquinolines.
Subject(s)
Dental Plaque/prevention & control , Hydroxyquinolines/analogs & derivatives , Oxyquinoline/analogs & derivatives , Oxyquinoline/chemical synthesis , Regression Analysis , Streptococcus mutans/growth & development , Structure-Activity RelationshipABSTRACT
Some 4- and 5-substituted 8-hydroxyquinolines, with predicted log P values in the range of 1.48-2.90, were synthesized by modified Skraup reactions or thermal cyclization. These hydroxyquinolines include the 5-methyl, 4,5-dimethyl, 4-methyl, 5-hydroxy-4-methyl, 5-methoxy, 5-methoxy-4-methyl, 4-hydroxy, 4-chloro, 4-amino, and 5-amino analogs. Partition coefficients, antibacterial activity, and antiplaque activity were determined. Four analogs showed in vitro antiplaque activity. None of the derivatives with ionizable functions was active.
