Carboxylation of phosphoenolpyruvate by extracts of Neisseria gonorrhoeae.

The enzymatic carboxylation of phosphoenolpyruvate by cell-free extracts of Neisseria gonorrhoeae was examined and determined to be similar to the reaction catalyzed by phosphoenolpyruvate carboxylase (PEPC). This was shown by the irreversibility of the reaction and nucleotide independency. The enzyme was found to have some characteristics different from the other bacterial PEPCs reported.

Dose-response of prolactin and thyrotropin to N3im-methyl-thyrotropin releasing hormone in euthyroid men.

The synthetic N3im-methyl analogue of thyrotropin releasing hormone (methyl-TRH) was administered intravenously to 15 euthyroid men, ages 36-62, in graded doses from 6.25 mug to 500 mug in order to establish the range of response of prolactin (PRL), TSH, T3 and T4 to various doses of methyl-TRH. There was a dose-related rise in serum TSH, PRL, T3, and T4 which gave a nearly linear relationship when the integrated area of response was used as an index of response to the various doses of methyl-TRH.

Prolactin response to N3im-methyl-thyrotropin releasing hormone in euthyroid subjects.

The N3im-methyl analogue of thyrotropin releasing hormone (methyl-TRH) was compared with ordinary TRH as a prolactin (PRL) releaser in 32 euthyroid volunteers (20 male and 12 female, ages 17-66 years). The mean PRL response to 100 mug of methyl-TRH was greater (P less than 0.025) than the PRL response to 500 mug of TRH at 10 min and at all sampling times from 30 to 240 min after administration of the releasing factors.

Effect of N3im-methyl-thyrotropin releasing hormone on the human pituitary-thyroid axis.

The N3im-methyl analogue of thyrotropin release hormone (methyl-TRH) was compared with TRH as a thyrotropin releaser in 30 euthyroid volunteers (ages 19-61 years). The mean TSH response to 100 mug of methyl-TRH was greater (P less than 0.005) than the TSH response to 500 mug of TRH from 10 min to 240 min after giving the releasing factors.

Preliminary studies in the clinical use of a bicarbonate containing growth medium for Neisseria gonorrhoeae.

A recent study from our laboratory demonstrated that the gaseous carbon dioxide atmosphere used for growth of Neisseria gonorrhoeae could be replaced by the addition of sodium bicarbonate directly to the growth medium. A comparative growth study was initiated using the Transgrow system and the bicarbonate system, Nei-Carb. The Nei-Carb system displayed several obvsiou advantages over the Transgrow system.

Effects of bicarbonate on growth of Neisseria gonorrhoeae: replacement of gaseous CO2 atmosphere.

The effect of NaHCO2 on the growth of Neisseria gonorrhoeae cultures was studied in a liquid and a semisolid growth medium. With a broth culture, NaHCO3 (0.009 M) greatly reduced the lag phase and also increased the total growth.

Jejunal perfusion of simple and conjugated folates in man.

The technique of human jejunal perfusion was used to study the process of digestion and absorption of conjugated folates in five healthy volunteers. The test solution of isotonic saline contained equimolar concentrations of purified [3H]pteroylmonoglutamate ([3H]PG-1) and of [14C]pteroylheptaglutamate ([14C]PG-7) which was labeled on the first glutamyl unit. Calculations were made of the luminal disappearance of each labeled folate, and degradation products of [14C]PG-7 were identified in luminal contents obtained 15 and 30 cm from the infusion site.

Bacteriophage tail components. V. Complementation of T4D gene 28 - -infected bacterial extracts with pteroyl hexaglutamate.

Synthetic pteroyl hexaglutamate (9 x 10(-6) M) stimulated the formation of new T4D particles in vitro in extracts of Escherichia coli B infected with T4D gene 28(-). The stimulation was specific for this form of folic acid since neither pteroyl pentaglutamate nor pteroyl heptaglutamate stimulated phage formation. T4D formation in vitro in E.

Studies on the absorption and metabolism of folic acid. I. Folate absorption in the dog after exposure of isolated intestinal segments to synthetic pteroylpolyglutamates of various chain lengths.

Folic acid absorption was studied in anesthetized dogs by determining the amount and chemical nature of folate in venous blood emerging from isolated intestinal segments containing free folic acid and/or pteroylpolyglutamates of a known chain length. Chromatographically pure test materials placed in the lumen were prepared by unambiguous solid phase synthetic methods. This synthetic procedure not only yields compounds of known structure, it also provides a means by which glutamic acid residues at any given position in the gamma glutamyl chain can be made radioactive.