Ion transport and ultra-efficient osmotic power generation in boron nitride nanotube porins.

Nanotube porins form transmembrane nanomaterial-derived scaffolds that mimic the geometry and functionality of biological membrane channels. We report synthesis, transport properties, and osmotic energy harvesting performance of another member of the nanotube porin family: boron nitride nanotube porins (BNNTPs). Cryo-transmission electron microscopy imaging, liposome transport assays, and DNA translocation experiments show that BNNTPs reconstitute into lipid membranes to form functional channels of ~2-nm diameter.

Acute in vitro and in vivo toxicity of a commercial grade boron nitride nanotube mixture.

Boron nitride nanotubes (BNNTs) are an emerging engineered nanomaterial attracting significant attention due to superior electrical, chemical and thermal properties. Currently, the toxicity profile of this material is largely unknown. Commercial grade BNNTs are composed of a mixture (BNNT-M) of ∼50-60% BNNTs, and ∼40-50% impurities of boron and hexagonal boron nitride.

Pathogenicity of Candida albicans auxotrophic mutants in experimental infections.

Auxotrophic and prototrophic control strain pairs of Candida albicans constructed by molecular biology methodologies were evaluated for pathogenicity in a systemic mouse model. Mutants that were auxotrophic for adenine, uracil, and heme each showed a lowered level of pathogenicity relative to control strains. It can be concluded from these experiments that decreased pathogenicity in each case is due to the auxotrophic mutation, because mutant and control strains were constructed so as to differ at a single locus.

Amphotericin B lipid complex therapy of experimental fungal infections in mice.

The amphotericin B lipid complex (ABLC), which is composed of amphotericin B and the phospholipids dimyristoyl phosphatidylcholine and dimyristoyl phosphatidylglycerol, was evaluated for its acute toxicity in mice and for its efficacy in mice infected with a variety of fungal pathogens. ABLC was markedly less toxic to mice when it was administered intravenously; it had a 50% lethal dose of greater than 40 mg/kg compared with a 50% lethal dose of 3 mg/kg for Fungizone, the desoxycholate form of amphotericin B. ABLC was efficacious against systemic infections in mice caused by Candida albicans, Candida species other than C.

Lysobactin, a novel antibacterial agent produced by Lysobacter sp. II. Biological properties.

Lysobactin, an antibiotic isolated from a strain of Lysobacter, is 2 to 4-fold more active than vancomycin against aerobic and anaerobic Gram-positive bacteria. Included in the spectrum of lysobactin are Staphylococci, Streptococci, corynebacteria, clostridia and various other Gram-positive anaerobic bacteria. The activity of lysobactin against aerobic and anaerobic Gram-negative bacteria is poor.

In vivo evaluation of tigemonam, a novel oral monobactam.

Tigemonam, a new monobactam with excellent activity against gram-negative bacteria, was evaluated for in vivo efficacy and absorption after oral administration to laboratory animals. Tigemonam is absorbed when administered orally to mice and dogs. In a variety of gram-negative systemic infections in mice, orally administered tigemonam was efficacious in all infections studied.

Evaluation of chemotherapeutic agents in experimental Haemophilus influenzae bacteremia and meningitis in infant rats.

Procedures for evaluating the efficacy of chemotherapeutic agents in an infant rat model of Haemophilus influenzae meningitis were developed. The results of efficacy studies with ampicillin, chloramphenicol, cefamandole, cefoxitin, and SQ 13,426 were compared to activity in vitro. While most of the drugs tested were very active against the two strains of H.

Evaluation of vaginal antifungal formulations in vivo.

Relatively simple and rapid procedures have been developed for evaluating the local efficacy of vaginal antifungal agents in vivo in a vaginal candidiasis model in ovariectomized rats. The results of this investigation indicate that the model and methods described are quite suitable for screening potential antifungal substances and for assessing the chemotherapeutic effectiveness of new antifungal agents and formulations before carrying out clinical studies.

Responsiveness of experimental surgical-wound infections to topical chemotherapy.

Topical agents freshly formulated in a cream base vehicle as well as commercial topical preparations were used to evaluate in mice the responsiveness of experimental surgical wounds infected with Staphylococcus aureus or Pseudomonas aeruginosa to chemotherapy. The responsiveness of the infections to therapy or the efficacy of a topical agent was assessed primarily by means of wound counts of the infecting organism before and after the employment of an immediate (prophylactic) or delayed (therapeutic) treatment regimen. From tests of several concentrations of an agent formulated in the vehicle, a median effective dose could be determined.