Sir, Studies in vitro and in animals have shown that killing of bacteria by -lactams is time dependent and maximal at relatively low concentrations, indicating optimal administration by continuous infusion. Continuous infusion of ceftazidime was recently reported to be well tolerated by children with cystic fibrosis. On the other hand, the bactericidal activity of aminoglycosides is concentrati...

been shown to form bilayer vesicles (cationic liposomes) and have been applied to gene delivery. Cationic vesicles designed for that purpose are generally intrinsically unstable. Although application of cationic liposomes has also been anticipated for the delivery of drugs, peptides, vitamins and lipids and other biologically active compounds to biological cells and tissues, liposomes used for ...

It has been observed that alterations in normal ECM structure and mechanotransduction play a role in heart valve diseases. Current paradigms in valve biology, cell culture and animal models, are inadequate for study of the agents that cause these alterations. A mitral valve organ culture system has been designed that stimulates mitral valves in a simulated in vivo environment for periods of 4-6...

We performed detailed photoluminescence (PL) spectroscopy studies of three different types of single-walled carbon nanotubes (SWNTs) by using samples that contain essentially only one chiral type of SWNT, (6,5), (7,5), or (10,5). The observed PL spectra unambiguously show the existence of an emission sideband at ~ 145 meV below the lowest singlet excitonic (E11) level, whose identity and origin...

Highly colored cranberries are desired for both fresh and juice markets. Berries accumulate more color when allowed to stay on the vines longer. However, early fall frosts often force growers to harvest before the fruit has reached its optimal color. This is especially true for the berries under the canopy. No product is currently available for grower to accelerate the color development in cran...

Two clinical trials were performed to investigate the antibacterial effects of SnF2 and to explore the apparent selective reduction of salivary S. mutans. In the first clinical trial, subjects were followed through baseline periods interposed between periods of either once or twice daily brushing with 0.4% SnF2. At weekly intervals, salivary samples from each subject were quantitated for S. mut...

Inositol phosphate kinases (IPKs) sequentially phosphorylate inositol phosphates (IPs) to yield a group of small signaling molecules involved in diverse cellular processes. Inositol 1,3,4,5,6pentakisphosphate 2-kinase (IPK1) phosphorylates IP5 to IP6; however, the mechanism of IP recognition employed by IPK1 is currently unresolved. We previously demonstrated that IPK1 possesses an unstable N-l...

Most nonmuscle cells are known to maintain a relatively high concentration of unpolymerized actin. To determine how the polymerization of actin is regulated, exogenous nucleation sites, prepared by sonicating fluorescein phalloidin-labeled actin filaments, were microinjected into living Swiss 3T3 and NRK cells. The nucleation sites remained as a cluster for over an hour after microinjection, an...

The fluorescent compound Hoechst 33342 is a substrate for many multidrug resistance (MDR) transporters and is widely used to characterize their transport activity. We have constructed mutants of the adenosine triphosphate (ATP) binding cassette (ABC)-type MDR transporter LmrA of Lactococcus lactis that are defective in ATP hydrolysis. These mutants and wild-type LmrA exhibited an atypical behav...

Much work is needed in the design of more effective bone tissue engineering materials to induce the growth of normal bone tissue. Nanotechnology offers exciting alternatives to traditional bone implants since bone itself is a nanostructured material composed of nanofibered hydroxyapatite welldispersed in a mostly collagen matrix. For this purpose, poly-lactic-co-glycolic acid (PLGA) was dissolv...