Black-hole universe: time evolution.

Time evolution of a black hole lattice toy model universe is simulated. The vacuum Einstein equations in a cubic box with a black hole at the origin are numerically solved with periodic boundary conditions on all pairs of faces opposite to each other. Defining effective scale factors by using the area of a surface and the length of an edge of the cubic box, we compare them with that in the Einstein-de Sitter universe. It is found that the behavior of the effective scale factors is well approximated by that in the Einstein-de Sitter universe. In our model, if the box size is sufficiently larger than the horizon radius, local inhomogeneities do not significantly affect the global expansion law of the Universe even though the inhomogeneity is extremely nonlinear.

Susceptibilities of 23 Desulfovibrio isolates from humans.

Antimicrobial susceptibilities of 23 strains of Desulfovibrio spp. were tested by Etest. Generally, Desulfovibrio spp. were highly susceptible to sulbactam-ampicillin, meropenem, clindamycin, metronidazole, and chloramphenicol: MIC(90)s of 6, 4, 0.19, 0.25, and 8 microg/ml, respectively. In addition, these strains generally showed high MICs to piperacillin and piperacillin-tazobactam. Desulfovibrio fairfieldensis (eight strains) was the species least susceptible to most agents, especially beta-lactams, and was the only species resistant to fluoroquinolones. Desulfovibrio desulfuricans strain Essex 6 isolates were less susceptible to beta-lactams than D. desulfuricans strain MB isolates.

In vitro antianaerobic activity of DX-619, a new des-fluoro(6) quinolone.

The in vitro activity of DX-619, a new des-F(6) quinolone, against anaerobic bacteria was evaluated. DX-619 showed potent activity against Bacteroides, Prevotella, Fusobacterium, Micromonas, Actinomyces, and Clostridium spp., with MIC(50)s/MIC(90)s of

[Application of "Microring AN" to "Level 1": presumptive identification of anaerobic gram-negative bacilli].

Commonly isolated anaerobic gram-negative rods (4 genus 64 strains), some other important gram-negative anaerobic species (9 genus 45 strains), and cigar-shaped clostridia (11 strains) were studied on their susceptibility patterns to 6 agents on "Microring AN". Some modifications were made in the methods and interpretation of results. Susceptibility patterns to erythromycin, rifampicin, colistin, benzylpenicillin, kanamycin, and vancomycin were following (sensitive [S], intermediate [I], resistant [R], variable [V]): for Bacteroides fragilis group, V, S, R, R, R, R, respectively; for non-pigmented Prevotella, V, S, V, V, R, R, respectively; for pigmented Prevotella, S, S, SR, V, V, R, respectively: for Fusobacterium nucleatum/necrophorum, R(S), S(I), S(IR), S(R), S, R, respectively; and for F. varium, R, R, S/I, R(S), S, R, respectively. Some results were different from that in the data table in the instruction of "Microring AN", because of differences of methodology and changes of susceptibility of those species during years. As to the other groups, that are not included in the data table in the instruction, results were following: for Bilophila wadsworthia, R, R, S, R, S, R, respectively; Desulfovibrio, V, R(S), R, R, S, R, respectively; for cigar-shaped clostridia, V, S(R), R, R, S(R), S, respectively. "Microring AN" was useful for presumptive identification in genus, species, or group level, though morphological observation and some additional simple tests such as bile-sensitivity and catalase were essential.