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Recent neurophysiological studies indicate a role for reticulospinal neurons of the pontomedullary reticular formation (PMRF) in motor preparation and goal-directed reaching in the monkey. Although the macaque monkey is an important model for such investigations, little is known regarding the organization of the PMRF in the monkey. In the present study, we investigated the distribution of reticulospinal neurons in the macaque. Bilateral injections of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) were made into the cervical spinal cord. A wide band of retrogradely labeled cells was found in the gigantocellular reticular nucleus (Gi) and labeled cells continued rostrally into the caudal pontine reticular nucleus (PnC) and into the oral pontine reticular nucleus (PnO). Additional retrograde tracing studies following unilateral cervical spinal cord injections of cholera toxin subunit B revealed that there were more ipsilateral (60%) than contralateral (40%) projecting cells in Gi, while an approximately 50:50 ratio contralateral to ipsilateral split was found in PnC and more contralateral projections arose from PnO. Reticulospinal neurons in PMRF ranged widely in size from over 50 microm to under 25 microm across the major somatic axis. Labeled giant cells (soma diameters greater than 50 microm) comprised a small percentage of the neurons and were found in Gi, PnC and PnO. The present results define the origins of the reticulospinal system in the monkey and provide an important foundation for future investigations of the anatomy and physiology of this system in primates.

A girl aged eight months, who presented with developmental delay and dislocated optic lenses, was diagnosed as having combined sulfite oxidase and xanthine dehydrogenase deficiencies consistent with molybdenum cofactor deficiency. The diagnosis was confirmed by demonstrating the absence in urine of urothione, a molybdenum cofactor metabolite. Prenatal diagnosis excluded the disease in the mother's second pregnancy. A summary of an in vitro study of molybdenum cofactor synthesis in the patient is given.

A new procedure is described for the selective determination of drugs containing a 1,2-diphenolic moiety. The assay is based upon the measurement of difference absorbance between two equimolar solutions of the drug in pH 7 phosphate buffer, one of which also contains 0.1 M boric acid. The difference absorbance, which is maximum at about 292 nm, is due to the different spectral characteristics of the boric acid ester of the drug and of the unesterified drug and is proportional to the concentration of the drug. The accuracy, precision, sensitivity and specificity of the procedure are discussed. Applications of the assay are described for adrenaline, isoetharine, isoprenaline, levodopa and methyldopa in pharmaceutical formulations.

Difference spectrophotometric procedures are described for the assay of triprolidine hydrochloride, dextromethorphan hydrobromide and pseudoephedrine hydrochloride in Actifed preparations. Triprolidine is assayed by the measurement of the difference absorbance at 301 nm between equimolar solutions of the sample extract in 0.1 M sulphuric acid and 0.1 M sodium hydroxide in ethanol (20% v/v). Dextromethorphan and pseudoephedrine are assayed by measurement of the amplitudes in the second and fourth derivative spectra of the difference absorption spectrum of the sample solutions. The measured values are proportional to the concentrations of the drugs. The accuracy, precision and selectivity of the procedures are discussed. Applications of the assay are described for Actifed Compound Linctus, Actifed Syrup and Actifed Tablets.

1. Between 1971 to 1977, 74,521 urines, collected on filter paper and mailed in, were screened by the Metabolic Screening Program of the Children's Hospital. These represented 45.9% of live births in B.C. hospitals were the program has been available. The mean age of the infants was 4.4 weeks. Urines were examined by chromatography with ethyl acetate-pyridine-water for sugars. 1423 (2.13%) had an abnormal pattern necessitating a repeat urine card. A persistent abnormality was noted in 167 (0.22%) and from these a liquid urine sample was obtained for two dimensional amino acid chromatography and/or a repeat sugar chromatography. 2. In 47 (0.06%) of these a definite metabolic abnormality was confirmed. These included cases of Iminoglycinuria (8), Hartnup trait (4), Nonketotic hyperglycinemia (2), Histidinemia (1), Cystathioninuria (5), Argininosuccinic aciduria (1), Maple Syrup Urine Disease (1), Diabetes Mellitus (1), Renal glycosuria (1) and Persistent galactosuria (3). 201 infants had a slight increase of cystine and/or lysine, and 19 of these were documented to be heterozygous for cystinuria.

A simultaneous assay of levodopa and benserazide in combined formulations is described that utilizes the different spectral properties of the drugs in the presence of germanium dioxide. Difference absorbances are measured at 238 and 292.5 nm between pH 6 solutions of the drugs complexed with germanium dioxide relative to equimolar solutions of the uncomplexed drugs. The concentrations are calculated using two simultaneous equations derived from the difference absorptivities of the individual drugs at 238 and 292.5 nm. The choice of wavelengths for maximum accuracy and precision is discussed. Good recoveries of the drugs in standard mixtures were obtained and satisfactory precision was demonstrated by the relative standard deviations of 0.46% and 1.07% for levodopa and benserazide, respectively, obtained in the replicate analyses of a sample of Madopar capsules. The accuracy of the procedure and the absence of interference from excipients were confirmed by the good agreement in the results for the assay of several batches of Madopar capsules and one of Madopar tablets with those obtained by the manufacturer by an HPLC procedure.

A rapid difference spectrophotometric assay of 5-hydroxymethylfurfuraldehyde (5-HMF) in certain degraded syrups is described. The method involves the measurement of the difference absorbance at 340 nm of the isonicotinoyl hydrazone of 5-HMF, formed at room temperature in an acidic solution of isoniazid, relative to an equimolar solution of 5-HMF, which has been reduced by sodium borohydride, and isoniazid reagent. The procedure is accurate, precise and selective for 5-HMF in the syrups examined. The limits of detection and determination are 0.91 mug ml(-1) and 12.4 mug ml(-1), respectively. The method has been applied to codeine linctus, paracetamol elixir (paediatric) opiate squill linctus, ipecacuanha and squill linctus, Phensedyl Linctus and invert syrup.

A rapid assay is described for the simultaneous determination of emetine and cephaeline in ipecacuanha and its preparations, based upon the different fluorescence intensities of the alkaloids at pH 1 and pH 12. The assay involves the measurement of fluorescence at 317 nm of dilutions of the sample in 0.1 M hydrochloric acid (pH 1) and 0.01 M sodium hydroxide (pH 12) with an excitation wavelength of 283 nm. Concentrations of the individual alkaloids are calculated using two simultaneous equations derived from the experimentally determined coefficients of fluorescence of solutions (1 mug/ml) of emetine and cephaeline at pH 1 and pH 12. The procedure, which has been shown to be accurate, precise and sensitive, requires only 1 ml of a liquid sample and less than 0.5 g of powdered root. There was reasonable agreement between the total concentrations of alkaloids in tinctures and liquid extracts of ipecacuanha determined by the spectrofluorimetric method and by the titrimetric procedure of the British Pharmacopoeia. The fluorimetric procedure gave higher levels of alkaloids in the powdered root than did the B.P. method; this difference is explained by incomplete extraction of the alkaloids in the B.P. procedure for powdered ipecacuanha root.

The effects of variation of temperature in the range 0 degrees -40 degrees C on the zero and second derivative ultraviolet absorption spectra of ten compounds have been investigated. When the temperature of the solutions was increased, most of the substances showed a linear reduction of maximum absorbance (A(max)), with temperature coefficients of -0.07 +/- 0.03% per degree. The second derivative amplitudes of all the substances were reduced, with temperature coefficients (-0.1 to -0.5% per degree) that bore no significant relationship to those of the corresponding A(max) values. These effects on the extrema of the derivative spectra are explained by the small reduction in curvature at the corresponding wavelengths of the fundamental spectra, that occurs with increasing temperature. The precise and accurate assay of substances by derivative UV spectrophotometry requires that the temperatures of the standard and sample solutions are identical at the time of measurement.

A rapid difference spectrophotometric procedure is described for the assay of 5-hydroxymethylfurfuraldehyde (5-HMF) in hydrolysed pharmaceutical syrups. The assay involves measurement of the difference absorbance at 283 nm (DeltaA(283)) of a solution of 5-HMF at pH 8 relative to that of an equimolar solution in which the absorption of the 5-HMF has been destroyed by reduction of the carbonyl group by sodium borohydride. The DeltaA(283) is proportional to the concentration of 5-HMF and is unaffected by the presence of sucrose (the sugar component of syrup) or of dextrose or laevulose (the principal sugars of invert syrup). The accuracy, precision and selectivity of the method are discussed. The limits of detection and determination are 0.78 microg ml(-1) and 9.6 microg ml(-1) respectively. The assay has been applied successfully to samples of syrup containing hydroxybenzoate (paraben) preservatives, invert syrup, simple linctus, ephedrine elixir and raspberry syrup.