Presence Of Propylene Glycol Research Articles

Preparation of monoiodotyrosine-13-glucagon

Glucagon was iodinated with the lactoperoxidase method at pH 10.0 in the presence of propylene glycol using a substitution of 0.3 g-atom I/mol glucagon. Under these conditions the reactivity of the iodine to tyrosine at position 13 is found to be 4-fold that of the tyrosine at position 10. The amount of diiodotyrosine was less than one-twentieth that of the monoiodotyrosine at either tyrosine residue. Relatively pure monoiodo[ 125I]tyrosine-13-glucagon can be separated from other iodoglucagons by means of DEAE-chromatography. Such a homogeneous preparation with a known position of the iodine makes it possible to study a specific interaction between the monoiodoglucagon and the glucagon antisera or the glucagon receptor.

EFFECTS OF 1,3,5, (10), 16 ESTRATETRAEN-3-OL ON MAMMALIAN L-FIBROBLASTS IN VITRO.

SummaryL-fibroblast cell cultures were treated with varying concentrations of 1, 3, 5, (10), 16-estratetraen-3-ol (#742) dissolved in propylene glycol. Propylene glycol (2%) was found to stimulate the mitotic rate. With #742 added the mitotic rate and total cell number were increased markedly. The presence of propylene glycol and #742 caused a distinct change in the morphology of the cells present in the cultures.

POTENTIATION OF GLUCURONIDASE HYDROLYSIS OF SODIUM PREGNANEDIOL GLUCURONIDATE

It has been observed that after long standing a reduction occurs in the activity of glucuronidase preparations of mammalian origin (e.g. Ketodase) on sodium pregnanediol glucuronidate (NaPG), either as a pure solution or in urine. This deterioration is characterized by increases in the optimum pH and in the amount of enzyme required to yield a complete hydrolysis of the NaPG. The fact that complete enzyme activity on pure NaPG solutions is restored by the addition of propylene glycol suggests that this deterioration might involve some glucuronyl transfer mechanism. Propylene glycol increases the activity of enzyme on pure NaPG solution by a factor of 6–15, reducing the amount of enzyme required to give a 95% hydrolysis in 4 hours from about 150 units/ml to 10 units/ml or by reducing the time required for 10 units/ml of enzyme to effect this hydrolysis from 24 to 4 hours. The presence of inhibitors in urine reduces this factor to 2, thus it requires half as much enzyme to effect a 95% or complete hydrolysis of the NaPG of urine in the presence of propylene glycol as in its absence. About two-thirds of the inhibitors toward the Ketodase hydrolysis of the NaPG in urine can be removed by simple (NH4)2SO4precipitation and extraction techniques. Thus 25 units/ml urine equivalent are capable of giving a complete hydrolysis of the NaPG in such extracts in the presence of propylene glycol, compared to 150 units/ml for the original urine under similar circumstances or 300–600 units/ml in the absence of propylene glycol.

STREPTOMYCIN IN THE THERAPY OF GRANULOMA INGUINALE

Streptomycin has been found to be active principally against certain gram-negative organisms and acid-fast bacilli. Its trial in the management of granuloma inguinale, while not entirely justified in view of the controversial concept of the nature of the pathogenic agent, was warranted on the basis that the need for a more effective and specific form of therapy of granuloma inguinale was greatly desired. Before the advent of the antibiotics the modem therapy of granuloma inguinale generally involved the use of one of a number of antimony compounds. These have varied from the intravenous injection of such antimonials as antimony potassium tartrate and diramin (an aqueous solution of the products resulting from the reaction between antimony catechol and triisopropanolamine in the presence of propylene glycol) to the intramuscular administration of the less toxic and more stable derivatives, such as lithium antimony thiomalate (anthiomaline) and stibophen. 1 In addition, adjuncts to antimony