Structure of UDP-N-acetylglucosamine enolpyruvyl transferase, an enzyme essential for the synthesis of bacterial peptidoglycan, complexed with substrate UDP-N-acetylglucosamine and the drug fosfomycin.

Background: UDP-N-acetylglucosamine enolpyruvyl transferase (MurA), catalyses the first committed step of bacterial cell wall biosynthesis and is a target for the antibiotic fosfomycin. The only other known enolpyruvyl transferase is 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase, an enzyme involved in the shikimic acid pathway and the target for the herbicide glyphosate. Inhibitors of enolpyruvyl transferases are of biotechnological interest as MurA and EPSP synthase are found exclusively in plants and microbes.

Cucurbitacin E-induced disruption of the actin and vimentin cytoskeleton in prostate carcinoma cells.

Cucurbitacin E has been identified by an empiric screening strategy as a sterol with potent growth inhibitory activity in vitro directed against prostate carcinoma explants (IC50 of 7-50 nM in 2- to 6-day exposures). The mechanism of cucurbitacin cytoxicity has not been elucidated previously. In the present study, we observed that cucurbitacin E caused marked disruption of the actin cytoskeleton, and in a series of cucurbitacin analogues, anti-proliferative activity correlated directly with the disruption of the F-actin cytoskeleton.

Enzymatic synthesis of UDP-galactofuranose and an assay for UDP-galactopyranose mutase based on high-performance liquid chromatography.

A method to prepare UDP-galactofuranose (UDP-Galf) free of UDP-galactopyranose (UDP-Galp) is described. The UDP-Galf is synthesized enzymatically from UDP-Galp using the enzyme UDP-galactopyranose mutase. Treatment of UDP-Galp with the enzyme yields an equilibrium mixture of UDP-Galp and UDP-Galf in which UDP-Galf is approximately 7%.

Transposition and fusion in the primary dentition: report of case.

A case is reported of the fusion and transposition of the maxillary right central and lateral primary incisors. The unerupted permanent successors exhibit anomalies as detailed previously in this paper.

Characterization of a Cys115 to Asp substitution in the Escherichia coli cell wall biosynthetic enzyme UDP-GlcNAc enolpyruvyl transferase (MurA) that confers resistance to inactivation by the antibiotic fosfomycin.

The antibiotic fosfomycin inhibits bacterial cell wall biosynthesis by inactivation of UDP-GlcNAc enolpyruvyl tranferase (MurA). Prior work has established that Cys115 of Escherichia coli and Enterobacter cloacae MurA is the active site nucleophile alkylated by fosfomycin and implicated this residue in the formation of a covalent phospholactyl-enzyme adduct derived from substrate, phosphoenolpyruvate (PEP). On the basis of sequencing information from putative MurA homolog from Mycobacterium tuberculosis, we generated a C115D mutant of E.

Evolving community health information networks.

A community health information network (CHIN) provides technology-based information services to help maintain optimal health for all the residents of a community. Defining features of a CHIN are that its services are available to all stakeholders and that competitors collaborate to share information. The initial impetus for a CHIN is usually to facilitate paying for health care or to share clinical records.

Cathepsin B is a prorenin processing enzyme.

Conversion of prorenin to renin results from proteolytic cleavage of a 43-amino-acid prorenin prosegment in renal juxtaglomerular cells. The enzyme that performs this processing is not known. Of several enzymes proposed, cathepsin B is a candidate because it colocalizes with renin in juxtaglomerular cell secretory granules and accurately cleaves the prosegment of human prorenin in vitro.

The development of magnetic resonance imaging in obstetrics.

Following recent developments in imaging techniques which overcome the problem of fetal motion, magnetic resonance imaging (MRI) has the potential to improve non-invasive fetomaternal assessment. This article catalogues the development of MRI and the potential that exists for its use in obstetrics in the future.

Mode of action of GR122222X, a novel inhibitor of bacterial DNA gyrase.

GR122222X is a potent inhibitor of the supercoiling reaction of bacterial DNA gyrase. We show that this compound binds stoichiometrically to inactivate the ATPase activity of a 43-kDa N-terminal fragment of the B subunit and competitively inhibits the binding of a radiolabelled coumarin drug to N-terminal fragments of GyrB. These and other data suggest that GR122222X has a mode of action similar, but not identical, to that of coumarin antibiotics.

Galactofuranose biosynthesis in Escherichia coli K-12: identification and cloning of UDP-galactopyranose mutase.

We have cloned two open reading frames (orf6 and orf8) from the Escherichia coli K-12 rfb region. The genes were expressed in E. coli under control of the T7lac promoter, producing large quantities of recombinant protein, most of which accumulated in insoluble inclusion bodies.

Antiproliferative effect in vitro and antitumor activity in vivo of brefeldin A.

Purpose: An empiric in vitro screen of human tumor cell lines found brefeldin A inhibited the growth of immortalized human cell lines, with particular sensitivity to brefeldin in a series of immortalized melanoma cell lines and nonimmortalized prostate carcinoma explants. Brefeldin A alters the morphology and function of the Golgi apparatus, endosomal, and trans-Golgi compartments in different cell types. The studies presented here sought to obtain evidence of in vivo antitumor activity by brefeldin A.

CHINs in the context of an evolving health care system.

Community Health Information Network (CHIN) developments have slowed, due to the chaotic change in the health care system and stakeholders' attendant short-sighted focus. CHINs are a long-term investment that is necessary for the health care system's evolution to maturity. Several arenas of essential CHIN activity are given that would be characteristic of a mature, goal-directed health care system Lack of enterprise-wide computer-based patient record systems is a major barrier.

Biosynthetic origin of mycobacterial cell wall arabinosyl residues.

Designing new drugs that inhibit the biosynthesis of the D-arabinan moiety of the mycobacterial cell wall arabinogalactan is one important basic approach for treatment of mycobacterial diseases. However, the biosynthetic origin of the D-arabinosyl monosaccharide residues themselves is not known. To obtain information on this issue, mycobacteria growing in culture were fed glucose labeled with 14C or 3H in specific positions.

High-throughput screen for detecting antimycobacterial agents.

A simple, robust assay system which can be used to screen for inhibitors of mycobacterial growth has been developed. A strain of the rapidly growing saprophyte Mycobacterium aurum is used as the test organism. Inhibition of its growth is highly predictive of activity against Mycobacterium tuberculosis, which cannot itself be used in screening because of its growth characteristics and highly infectious nature.

A somatic cell genetic method for identification of untargeted mutations in the glucocorticoid receptor that cause hormone binding deficiencies.

Mouse T lymphoma cell line W7MG1, which is killed by physiological concentrations of glucocorticoid agonists, was used as a convenient genetic system for isolating sublines containing mutant glucocorticoid receptors (GR) with hormone-binding deficiencies. Partially hormone-resistant cell clones were derived from chemically mutagenized cell populations by selecting for growth in moderate concentrations of dexamethasone (Dex) and then screening for failure to grow in high Dex concentrations. Such clones are likely to have mutant GR.

Distinguishing depressed from nondepressed individuals using energy and psychosocial variables.

This study was conducted to determine whether energy level can be used to distinguish depressed from nondepressed individuals and to assess the relative importance of energy level and psychosocial variables in making this distinction. Fifty-seven participants experiencing a current episode of major depression and a matched sample of nondepressed participants completed a self-report questionnaire containing measures of energy level and psychosocial variables. Discriminant analysis revealed that energy level correctly classified 93% as depressed or nondepressed, whereas psychosocial variables correctly classified 87%.

Pelvic ultrasound findings in different forms of sexual precocity.

Recently produced reference curves for various ultrasound dimensions were used to retrospectively assess 67 pelvic ultrasound scans carried out at the initial presentation in girls with sexual precocity. At presentation the group with precocious puberty had significantly increased uterine lengths and ovarian volumes compared with the normal population, and a significantly increased fundal-cervical ratio. Ovarian volume was also significantly increased in therlarche and thelarche variant.

Pelvic ultrasound measurements in normal girls.

Pelvic ultrasound scans were carried out in 153 normal girls aged between 3 days and 14.9 years, in order to obtain reference data for ovarian volume, uterine length and uterine configuration. The right ovary was significantly larger than the left (by about 17%).

Prospects for new interventions in the treatment and prevention of mycobacterial disease.

Mycobacterium tuberculosis claims more lives each year than any other single human pathogen. Despite the availability of effective drugs, the incidence of tuberculosis is increasing in much of the developing world and has recently reemerged as a public health problem in industrialized countries. In the first section of this chapter, current understanding of the fundamental biology of mycobacterial infection is reviewed from the perspective of development of new tools for disease control.

Synthesis and biological activity of novel cephalosporins containing a (Z)-vinyl dimethylphosphonate group.

A series of cephalosporins containing a novel 7-[2-(Z)-(2-amino-thiazol-4- yl)-3-(dimethoxy-phosphoryl)-acryloylamino] group were prepared and their antibacterial activity measured against a range of pathogens. In general the compounds displayed a broad spectrum of activity against both Gram positive and Gram negative organisms, except Pseudomonas aeruginosa. Activity against the latter could be achieved by introducing a catechol moiety at the 3 position of the cephalosporin.

Intraperitoneal fluid collections following liver transplantation in a paediatric population.

Reduced-size liver transplant techniques are now widely used in paediatric liver transplantation programmes. An argument against their use is the potential for an increased incidence of post-operative fluid collections arising from the cut surface of the liver. The distribution and management of fluid collections after 70 paediatric liver transplants (18 whole and 52 reduced), performed over a 3 year period is reported.