Clinical Trial of Lincomycin Hydrochloride in Reiter's Disease

A double-blind trial comparing lincomycin hydrochloride (Mycivin) and placebo in 22 patients with Reiter''s disease showed no significant difference in clinical or laboratory findings between the two groups. It is concluded that lincomycin hydrochloride is no more effective than placebo in the treatment of Reiter''s disease.     

Effect of Lytic Enzymes of Acanthamoeba castellanii on Bacterial Cell Walls

Extracts of Acanthamoeba castellanii (Neff) contain alpha- and beta-glucosidase, beta-galactosidase, beta-N-acetylglucosaminidase, amylase, and peptidase. All of these activities are optimal between pH 3 and 4. These extracts also were found to clarify suspensions of cell walls from nine different gram-positive bacteria, including Micrococcus lysodeikticus. The pH optimum for the lytic activity was between 3 and 4. The extent of lysis of the various cell walls did not correlate with the release of free amino groups and of free N-acetylated sugars from the walls during digestion with these extracts. Suspensions of cell walls of Escherichia coli (a gram-negative bacterium), Cordiceps militaris (a fungus), and Acanthamoeba cysts, as well as of colloidal chitin, were not clarified by incubation with these extracts, although reducing sugars were released from each of these materials. Exhaustive digestion of M. lysodeikticus walls by lysozyme released no free N-acetylglucosamine. The products of exhaustive digestion of this cell wall with Acanthamoeba extracts were free N-acetylglucosamine, free N-acetylmuramic acid, glycine, alanine, glutamic acid, lysine, and N-acetylmuramic acid peptide fragments. These results suggest that the amoeba extracts contain endo- and exo-hexosaminidases, in addition to beta-hexosaminidase and peptide hydrolases.     

Action Spectrum for Growth Delay Induced in Escherichia coli B/r by Far-Ultraviolet Radiation

An action spectrum for growth delay induced in Escherichia coli B/r by far-ultraviolet radiation (230 to 295 nm) was obtained. It resembles the action spectrum for killing obtained in the same experiments, indicating that the chromophore for growth delay is probably the same as the chromophore for killing. Another action spectrum for killing, obtained under conditions more suitable for chromophore identification, suggests that nucleic acid, either deoxyribonucleic acid or ribonucleic acid, is the chromophore for growth delay induced by far ultraviolet. Isoprenoid quinones, which seem to be important chromophores for growth delay induced by near-ultraviolet radiation (above 300 nm), appear to play a negligible role in growth delay induced by wavelengths below 300 nm.     

Acetylation of serotonin in vitro by a human N-acetyltransferase

1. There is a well-recognized genetic polymorphism for the N-acetylation of isoniazid and sulphamethazine by human livers. 2. Serotonin was found to be acetylated by human liver enzyme preparations and the N-acetylserotonin formed was identified and determined quantitatively. 3. In 13 livers examined there was a wide variability in the capacity to acetylate serotonin that did not correlate with the capacity of the same livers to acetylate isoniazid and sulphamethazine. The results suggest that serotonin is not a natural substrate for the polymorphic N-acetyltransferase and that it may be acetylated by a different enzyme.     

Continuities between mitochondria and endoplasmic reticulum in the mammalian ovary

Summary An electron microscope study of developing mouse oocytes has revealed a close morphological relationship between mitochondria and endoplasmic reticulum. In many instances, it was noted that the outer mitochondrial membrane was continuous with the reticular membranes. These cytoplasmic membranes are smooth or studded with ribosomes. These continuities establish an open channel between the endoplasmic reticulum and mitochondria. Similar connections are also found in isolated preparations of mitochondria from the adult guinea pig ovary. The functional significance of these observations are discussed in relation to biochemical studies which demonstrate a transfer of protein from endoplasmic reticulum to mitochondria.     

Feeding and the control of volume within the tests of regular sea-urchins

The rigid, fluid filled, echinoid test presents problems of internal volume control when the vital functions of the animal involve the introduction of material, from outside the test, into the internal fluid systems. The volume of food in the guts of echinoids can be shown to vary considerably in the short term, to an extent which demands considerable capabilities for internal volume compensation. This is achieved by adjusting the quantity of fluid held within the gut so that, although the volume of food may vary widely, the total volume of the gut remains constant within narrow limits. The volume of gut fluid varies inversely with the quantity of food, and ingestion of food through the mouth is compensated by ejection of an equal volume of fluid from the anus. Defaecation is compensated by intake of fluid into the gut. On starvation, the gut becomes completely fluid filled and free from food.
The food of regular urchins is habitually compacted into regularly sized subpherical pellets covered with a tough mucus coating. The formation of coated pellets takes place in the buccal cavity and pharynx. The pellets remain discrete throughout their passage along the gut. The mucus coating resists digestion and remains intact even after defaecation. The functional morphology of the buccal cavity and pharynx is described in detail.
It is suggested that the functional significance of the pellets is associated with the gut fluid, volume compensation mechanism, which requires free flow of fluid throughout the length of the gut. It is also suggested that the siphon may be implicated in volume control, where fine adjustment of gut volume can be achieved by balancing ejection of fluid from the anus with intake of water through the mouth, but that the water intake is by the siphonal route, thus avoiding the necessity of flushing and diluting the enzyme rich digestive stomach region.     

Immunological studies in tropical splenomegaly syndrome in Uganda

An immunological evaluation carried out in eight patients with the tropical splenomegaly syndrome showed no evidence of impairment in cellular or humoral immunity, though raised levels of macroglobulins were noted in four patients. Hence gross immunological deficiency cannot be associated with the intense lymphoreticular proliferation observed in this disorder.