Macrolide antibiotics M-4365 produced by Micromonospora. III. In vitro antimicrobial activity of antibiotic M-4365G2 (de-epoxy rosamicin)

Antibiotic M-4365G2 (de-epoxy rosamicin) produced by Micromonospora capillata MCRL 0940 is a new basic 16-membered macrolide antibiotic with activity equal to or superior to erythromycin and josamycin against Gram-positive bacteria. Of interest are the high degree of activity against Gram-negative bacilli and mycoplasmas, and striking inhibitory effects against indole-producing Proteus spp. Bactericidal activity of M-4365G2 is also to be noticed.

Sarcoma botryoides arising from the biliary tract of children. A case report with review of the literature

Sarcoma botryoides (embryonal rhabdomyosarcoma) originating from the common bile duct is reported in a 4-year-old girl. Grossly, the tumor is characterized by multiple polypoid and grape-like projections into the lumen of the common bile duct and shows plate-like thickening of the common bile duct wall. On multiple cut-sections these polypoid masses are soft and light yellow white except for multifocal hemorrhage. Histologically the tumor consists of undifferentiated mesenchymal cells with a myxomatous appearance; rhabdomyoblasts with varing degree of maturation are scattered here and there within the matrix. These cells are characterized by a strap and racket shape with abundant eosinophilic cytoplasm and elongated cytoplasm with cross striations. The histogenesis of the tumor may be related possibly to an abnormal differentiation of the primitive mesenchymal cells toward striated muscle cells.

Permanent loss of chromosome initiation in toluene-treated Bacillus subtilis cells

Initiation of deoxyribonucleic acid replication is absent in Bacillus subtilis cells made permeable by toluene. The absence of initiation may be (i) a temporary removal of toluene, or (ii) irreversibly lost due to damage by toluene treatment to a cellular structure or a process required for chromosome initiation. Washed cells, previously treated with toluene and subsequently washed free of detectable amounts of toluene, have the same characteristics of toluene-treated cells in which toluene is not removed. The continued absence of initiation in the washed cells indicates a permanent loss of initiation in cells treated with toluene. Protein synthesis is also inhibited irreversibly by toluene treatment, indicating damage to translation as a possible mechanism for loss of initiation of toluene-treated cells.

Tests for deoxyribonucleic acid synthesis in toluenized Bacillus subtilis cells

Several tests were devised to further characterize deoxyribonucleic acid (DNA) synthesis in toluenized Bacillus subtilis cells. Vigorous agitation of toluenized cells (localization test) demonstrated that the DNA replication is exclusively a cell-associated process. A DNA "repair" condition was also applied to toluenized cells and shown to be distinct from DNA replication in its DNA polymerase I dependency and its ability to synthesize DNA on template which is either cell associated or free, outside the cell. This repair condition was used in conjunction with the localization test to demonstrate the penetration of deoxyribonuclease I and possibly DNA polymerase I into toluenized cells. Therefore, we suggest that the localization test can be used to test the penetration of proteins into toluenized cells for both the DNA repair and replication processes.

Highly Sensitive Light-induced Memory Effect with Amorphous Se-SnO(2) Heterojunction

The light-induced memory effect in amorphous selenium films is studied by fabricating them into a sort of heterojunction (Se-SnO(2)) so as to be able to apply the bias voltage together with the laser beam irradiation for memory. Under the reverse bias voltage, a region of high electric field is formed in the selenium film near the junction. Remarkable enhancement in the photo-induced image spot is achieved if an appropriate bias voltage is applied simultaneously, indicating the sensitization of the memory effect due to the photocurrent induced by the high electric field in the selenium film.