Complications of the treatment of congenital dislocation of the hip by the Pavlik harness

The results of the treatment of congenital dislocation of the hip using the Pavlik harness were satisfactory, but lateral displacement and deformity of the femoral head were sometimes observed after treatment. The causes of these complications are discussed and the measures taken to avoid them are discribed.

Determination of 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide (virazole) in blood and urine by chemical ionization-mass fragmentography

A combined gas chromatographic-mass spectrometric technique is described for the quantification of virazole in serum and urine. Proteins are removed by molecular filtration, lipids by extraction with dichloromethane and interfering endogenous constituents by acidic and basic ion-exchange resins. Virazole is quantified by monitoring the protonated molecular ions of the fully silylated derivatives of virazole (m/e 533) and the arabinose analog (internal standard) obtained by methane chemical ionization. The detection limit is 150 pg (0.6.10(-12) mole) of virazole injected. In serum 10 ng/ml (4.10(-8) mole) can be detected, 25 ng/ml quantified. In urine 0.5 microgram/ml can be quantified without preconcentration. Virazole was detected in serum for at least 96 h at the 70-ng/ml level.

Mass fragmentographic determination of pyrazinamide and its metabolites in serum and urine

A combined gas chromatographic-mass spectrometric technique is described for the simultaneous determination of pyrazinamide and its two main metabolites, pyrazinoic acid and 5-hydroxypyrazinoic acid. Serum (200 microliter) is deproteinized and evaporated to dryness; urine (20 microliter) is evaporated. The crude residues are silylated and selected ions are monitored in the chemical-ionization mode with isobutane as both chromatographic carrier and reagent gas. The sensitivity is 10 ng/ml for pyrazinamide and pyrazinoic acid and 20 ng/ml for the 5-hydroxy metabolite in a single analysis. Nicotinic acid and nicotinamide are internal standards. Both unchanged drug and metabolites were identified and quantified in the serum and urine of human subjects.

Preclinical toxicological study of phosphonoacetic acid: determination in blood by selected ion monitoring

Confirmed observations of the inhibition of oncogenic viruses by phosphonoacetic acid led to preclinical trials in animal model systems. Circulating phosphonoacetic acid was detected in the blood of mouse, rabbit and monkey after oral or subcutaneous administration of the drug. Phosphonoacetic acid is quantified in blood, after removing proteins and lipids, as the trimethylsilylated derivative, by monitoring the intensity of the protonated molecular ion and also that of phosphonopropionic acid (internal standard) using chemical ionization mass spectrometry combined with gas chromatography. The detection limit is 20 ng ml-1 when 0.2 ml serum is analyzed. A dosage of 230 mg kg-1 day-1 by continuous infusion is proposed for therapeutic trials in monkeys. This dose is well tolerated and results in slowly increasing blood levels of phosphonoacetic acid which reach a maximum of approximately 50 microgram ml-1 in a four day infusion, and decrease to 2 microgram ml-1 24 h after termination.

Ontogenetic expression of larval and adult hemoglobin phenotypes in the intergeneric salmonid hybrids

Ontogeny of the hemoglobins of Honmasu (Oncorhynchus rhodurus, HXH),brook trout (Salvelinus fontinalis, BXB) and their reciprocal hybrids (HXB and BXH) was examined electrophoretically as well as spectrophotometrically. All of these fish have electrophoretically distinct larval and adult type hemoglobins and the transition from one type to the other occurred early during post-hatching development. In the case of larval hemoglobins, the electrophoretic pattern of a hybrid, BXH, resembled that of the maternal parent, brook trout (BXB), while the hemoglobin of the reciprocal hybrid, HXB, differed markedly from that of the maternal parent, Honmasu (HXH), in that it possesses a diffuse pattern. Spectrophotometric examinations indicated that this was mostly methemoglobin. Adult type hemoglobins at more advanced stages of both hybrids were electrophoretically resolved into the parental hemoglobins. However, no "hybrid" hemoglobins were detected. Because there was abnormal hemoglobin formation in the larval erythrocytes (erythrocytes L) of the HXB hybrid, and then normal hemoglobin synthesis in the adult erythrocytes (erythrocytes A) of the same fish at later developmental stages, it appears that the paternal effects upon the hemoglobin differed in these two erythroid cell lines of the developing trout.