A species comparison of 2,4-dinitrotoluene metabolism in vitro.

Postmitochondrial supernatants prepared from livers of mice, rats, rabbits, dogs, and monkeys metabolized 2,4-dinitrotulene. The pattern of metabolites was characterized in both sexes of the species examined. In addition, the pattern of metabolites was altered by varying incubation conditions and pretreating male rats with phenobarbital or SKF 525-A.     

Changes in beta-2 adrenergic receptor sensitivity with maturation of erythroid progenitor cells.

Erythroid burst forming units (BFU-E) were much more sensitive to the beta-2 selective adrenergic drug, salbutamol, than erythroid colony forming units (CFU-E) in an in vitro study of erythroid progenitor cells.     

The influence of insulin, cAMP and the calcium ionophore X 537 A on the growth of the cartilage analagen of limb buds in vitro.

Limb buds of 11-day-old mouse embryos were cultured for 6 days with insulin, dibutyryl cAMP and X 537 A. The cartilage anlage was reduced by insulin and enlarged by dibutyryl cAMP and X 537 A. The effects are due to changes in the amount of intercellular substance.     

The inability of nuclear dehydrogenating clostridia to oxidize bile salt hydroxyl groups.

In a survey of the intracellular bile salt oxidoreductase activity in fecal bacteria, 16 strains of nuclear dehydrogenating clostridia and 2 strains of non-nuclear dehydrogenating C. paraputrificum were demonstrated unable to oxidize cholate at any of the 3 OH groups. Since nuclear dehydrogenation at the delta-1 and delta-4 position requires a 3-oxo precursor steroid, it appears that these organisms require the presence of a 3 alpha-hydroxysteroid dehydrogenating organism for nuclear dehydrogenation.     

Octopamine levels during the moult cycle and adult development in the migratory locust, Locusta migratoria.

Octopamine content of the head of the locust Locusta migratoria has been determined during the last larval stage, moulting and adult life of 3 groups of insects: female and male gregarious, solitary and CO2 solitarized. An important difference was found between these 3 groups. Octopamine contents increased in the middle of the larval life and during the adult life. The moulting time is characterized by a sharp decrease of the octopamine content which becomes identical in the 3 groups of insects. The relation between octopamine content, hormone cycles and motility is discussed.     

Presumptive identification of aminoglycoside antibiotics by the pH susceptibility disc agar-diffusion method.

Using the pH (buffered) sensitivity discs for the agar-diffusion bioassay of aminoglycoside antibiotics, characteristic response curves were obtained. Since the nature of the activities observed are structure-related, this method can serve as a useful aid for primary identification of members of this class of antibiotics.     

Age variation in the increase of hypothalamic and brain stem contents of phenylethanolamine m-octopamine and p-octopamine in spontaneously hypertensive rats (SH Kyoto).

Phenylethanolamine, m-octopamine and p-octopamine contents were determined as a function of age in the hypothalamus and brain stem of spontaneously hypertensive rats and controls Wistar Kyoto. In hypothalamus, the content of the 3 amines was 2--4-fold greater for the SH rats. In the brain stem, the phenylethanolamine and p-octopamine contents were 2--3-fold greater in SH rats but 5--6-fold higher in the case of m-octopamine. The difference appears at 3 weeks and correlates the blood pressure with the increase of age. The significance of these findings is discussed.     

Inhibition of the NADP-linked glutamate dehydrogenase from Trypanosoma cruzi by silver nitrate.

The purified NADP-linked glutamate dehydrogenase from Trypanosoma cruzi was strongly inhibited by silver nitrate. The inhibition was reversed by reduced glutathione, and was modified by the presence of the substrates during preincubation of the enzyme with the inhibitor.