STRUCTURE AND BIOLOGICAL ACTIVITY OF LIPIARMYCIN
Actinoplanes deccanensis ATCC21983, the producer of antibiotics lipiarmycin A3 and A4, furnished also a related antibiotic designated lipiarmycin B, active against Gram-positive bacteria, including anaerobes, and against Neisseria. The structures of the two major components, B3 and B4, were elucidated from their physico-chemical properties, XHand 13C NMRspectra and fast atom bombardmentmass spectra data in comparison with lipiarmycins A3andA4.
Fidaxomicin (OPT-80) for the treatment of Clostridium difficile infection
Importance of the field: Clostridium difficile infection (CDI) has become an increasingly important healthcare-associated complication in many countries. CDI outbreaks, a new ‘hypervirulent’ form and increased worldwide rates have underscored four urgent unmet needs for this disease: i) effective prevention of CDI; ii) therapies to produce faster resolution of CDI symptoms; iii) therapies to treat severe CDI more effectively and reduce its mortality; and iv) therapies to reduce the CDI recurrence rate following treatment. Areas covered in this review: Fidaxomicin, a new macrocyclic antibiotic, has demonstrated potent in vitro activity against C. difficile with limited or no activity against normal fecal flora. It is minimally absorbed from the intestinal tract, even in the presence of intestinal inflammation. When tested against oral vancomycin in clinical studies of CDI therapy, it has equivalent efficacy for curing CDI at end of treatment and a comparable safety profile to that agent. However, fidaxomicin therapy of CDI is associated with significantly fewer CDI recurrences in the 28 days following treatment. Symptom resolution is also slightly quicker in some CDI patients. Additional fecal flora analysis in the CDI trials showed that fewer individuals developed intestinal colonization with vancomycin-resistant enterococci (VRE) among the fidaxomicin-treated group. This new molecule, which has just completed two large Phase III multicenter studies, successfully addresses two of the four urgent and unmet needs for dealing with CDI. What the reader will gain: Fidaxomicin is as effective and as safe as vancomycin therapy for treating CDI but is associated with far fewer recurrences post-treatment and a decreased risk of VRE acquisition. Take home message: Fidaxomicin is a potential new therapy for CDI which has the capacity to substantially decrease post-treatment recurrences and is as safe and well-tolerated as standard vancomycin treatment.
Diskless linux system with unionfs for an educational computer center
The total cost of ownership is a major concern for computer centers that maintain hundreds of PCs. From our experience, it would be most important to reduce hardware faults, particularly the troubles of hard disk drives. This paper describes how we built our educational computer system using diskless PCs. Before constructing our system, the following items were listed as the objectives of client PCs: (1) run Linux, (2) work without local HD, (3) deploy a single OS image to all PCs, (4) be easy to update the OS image, (5) be applicable to as many device configurations as possible, (6) become clients for unix servers (Linux, Solaris, AIX, etc.), and (7) use open sources. We chose Vine Linux 3.1, which is a derivative of RedHat Linux and is well organized for Japanese language environment. To satisfy (3) and (5), we introduced unionfs which has stackable file system feature. The system directories and files dependent on each PC such as /tmp, /dev, /var, /etc/mtab, and /etc/fstab are generated as memory files systems in the boot procedure, and are stacked on the common OS image using unionfs. Since this stack mechanism was implemented only by adding some hook codes to /etc/rc.d/rc.sysinit, our idea, we believe, is applicable to other Linux distributions. Our educational computer system consists of 8 servers, 12 boot servers and 500 diskless PCs, and is now in operation.