Ernest Bueding

Occurrence of oxidative phosphorylations in the muscle of Ascaris lumbricoides.

Abstract The occurrence of aerobic phosphorylations in preparations of Ascaris muscle has been demonstrated. A particulate fraction of the muscle, a non-dialyzable component of the parasites perienteric fluid and the presence of a substrate (pyruvate) and of diphosphoryridine nucleotide are required. In low concentrations dinitrophenol uncouples oxidative phosphorylations, but this effect is less pronounced or even abolished in the presence of higher concentrations of dinitrophenol.

Content and distribution of glycogen in Schistosoma mansoni.

Summary From 13.6 to 29.0% of the dry matter of the males of S. mansoni consisted of glycogen. In females the amount varied between 2.7 and 5.0%. The glycogen in both male and female worms was deposited principally in the musculature and parenchyma. The relatively small amount in the female is explained by the less well-developed musculature and parenchyma and the more abundant sexual apparatus which is glycogen negative. Histological studies were in general accord with the quantitative observation that the amount of glycogen in the male tends to increase with age.

The immunological specificity of lactic dehydrogenase of Schistosoma mansoni.

Abstract An antiserum against lactic dehydrogenase of Schistosoma mansoni markedly inhibited the activity of this enzyme as well as those of the enzymes catalyzing the same reaction in Schistosoma japonicum and in Schistosoma haematobium . The same immune serum had no effect on the activities of lactic dehydrogenase of rabbit muscle and on those of another glycolytic enzyme of Schistosoma mansoni , phosphohexose isomerase. Reduced diphosphopyridine nucleotide, one of the substrates of lactic dehydrogenase, protected the schistosome enzymes from the inhibitory effect of the antiserum.

Survival of Schistosoma mansoni in vitro.

Summary 1. A method is described for studying the survival of S. mansoni in vitro. 2. These parasites survived in serum for 14 to 18 days; in serum ultranltrate for 10 to 12 days. 3. In a chemically defined medium, the survival of the parasite did not exceed 18 hours. 4. Addition of an aqueous extract of beef muscle or of a purified fraction of protogen to the synthetic medium significantly increased the period of survival. 5. Under completely anaerobic conditions the schistosomes survived for 5 days.

Effect of 2-Methyl-l,4-Naphthoquinone on Glycolysis of Schistosoma mansoni.∗

Conclusions 2-Methyl-1,4-naphthoquinone markedly inhibits aerobic glycolysis of Schistosoma mansoni in vitro. Since glycolysis, rather than oxidative metabolism, appears to be essential for the survival of these organisms, and since the toxicity of 2-methyl-1,4-naphthoquinone for mammalian species is low, the effect of this compound in experimental schistosomiasis has been studied. Results in mice suggest that the compound may act synergistically with subcurative doses of antimonials (“Fuadin”).

EFFECT OF CYANINE DYES ON THE METABOLISM OF LITOMOSOIDES CARINII

The cyanine dyes in concentrations as low as 5 x M ( 1 : 40,000,000) inhibit the oxidative metabolism of Litomosoides carinii. The inhibition of the respiration of these worms produced by the cyanines is associated with a compensatory increase in aerobic glycolysis. This effect of the cyanines on filarial metabolism is not limited to conditions in uitro. After the intraperitoneal injection of subcurative doses of a cyanine dye to filariae infected cotton rats, the worms removed from the pleural cavity of the host survive and remain motile, but their oxygen uptake is decreased and their rate of aerobic glycolysis is increased. Since the administration of two to four times higher doses results in the death of the parasite, it appears that the curative action of the cyanines in filariasis of the cotton rat is due to an inhibitory effect of these compounds on the respiratory metabolism of the parasite. The respiratory metabolism of L. carinii is inhibited by low concentrations of all compounds having the amidinium ion system in which a positively charged quaternary nitrogen is linked to a tertiary nitrogen by a conjugated chain of at least three carbons in length. Both nitrogens may be incorporated in heterocyclic rings (cyanine dyes),

Metabolism of renal cortex in nephrotic syndrome of rats.

Summary 1. The oxygen uptake of renal cortex slices of 29 control rats and 42 animals in which the nephrotic syndrome had been induced by the intravenous injection of nephrotoxic sera was studied. 2. In Krebs-Ringer solution, without added substrates, the average oxygen uptake of cortex slices of nephrotic rats did not differ from that of the controls. 3. Addition of glucose or of fructose resulted invariably in an increase in the oxygen uptake in the control slices. No consistent increase after addition of these two hexoses was noted when the kidney slices were obtained from nephrotic rats. 4. The increase in oxygen uptake of nephrotic slices produced by lactate, succinate, glutamate, acetoacetate and butyrate was equal to or only slightly less than in the corresponding control experiments. 5. Racemic alanine stimulated the oxygen uptake of the slices to a lesser degree in the nephrotic group. 6. Since oxidation of lactate, of succinate, and of glutamate proceeded at a normal rate, the inability of glucose and fructose to raise the oxygen uptake of nephrotic kidney slices cannot be ascribed to an inhibition of the cytochrome system or of the enzymes involved in the tricarboxylic acid cycle.

Reduction In the Number of Adult Trichinella spiralis in Rats After Treatment with Naphthoquinones.

Summary The oral administration of 2-methyl-1,4-naphthoquinone and 2 hydroxy-3-piperidinomethyl-1,4-naphthoquinone to rats infected with Trichinella spiralis produced a significant reduction in the number of intestinal adult trichinellae. Nine other structurally related naphthoquinones had no such effect.