A Controlled Clinical Trial Using Placebos in Normal Subjects: A Teaching Exercise

An exercise for medical students was designed to illustrate one method of setting up a clinical trial and incidentally to demonstrate some effects of placebos. Twelve groups of four students participated: one in each group was the “recorder”, the other three (volunteers) were randomly assigned to the treatment A, treatment B, or untreated groups. Subjects performed seven psychomotor or mental tests before taking medication and 30 and 60 minutes after medication. The time taken for the tests and the errors made were recorded. Treatment A was one green and yellow gelatin capsule filled with lactose, taken with water; treatment B was a red and white capsule containing lactose; untreated subjects received a drink of water. No large changes in performance occurred and no evidence of fatigue or learning was noted, although the B''s took significantly longer to perform the arithmetic test after medication than before. Treated subjects were instructed to check any of 29 listed side effects that they experienced. A total of 44 side effects was reported: 8 of 12 in A group and 10 of 12 in B checked one or more symptoms. Indications are that the results of the trial will not soon be forgotten.     

Cyclin-dependent kinases control septin phosphorylation in Candida albicans hyphal development

Cyclin-dependent kinases (Cdks) control cytoskeleton polarization in yeast morphogenesis. However, the target and mechanism remain unclear. Here, we show that the Candida albicans Cdk Cdc28, through temporally controlled association with two cyclins Ccn1 and Hgc1, rapidly establishes and persistently maintains phosphorylation of the septin cytoskeleton protein Cdc11 for hyphal development. Upon hyphal induction, Cdc28-Ccn1 binds to septin complexes and phosphorylates Cdc11 on Ser394, a nonconsensus Cdk target. This phosphorylation requires prior phosphorylation on Ser395 by the septin-associated kinase Gin4. Mutating Ser394 or Ser395 blocked Cdc11 phosphorylation on Ser394 and impaired hyphal morphogenesis. Reconstitution experiments using purified Cdc28-Ccn1, Gin4, and septins reproduced phosphorylations on the same residues. Transient septin-Cdc28 associations were also detected prior to bud and mating-projection emergence in S. cerevisiae. Our study uncovers a direct link between the cell-cycle engine and the septin cytoskeleton that may be part of a conserved mechanism underlying polarized morphogenesis.     

In vivo activity of an azole series of CCR2 antagonists

Optimisation of a series of biaryl sulphonamides resulted in the identification of compound 7 which demonstrated dose-dependent and strain-specific inhibition of monocyte recruitment in a thioglycollate-induced peritonitis model of inflammation.     

Phase-Variable Surface Structures Are Required for Infection of Campylobacter jejuni by Bacteriophages

This study characterizes the interaction between Campylobacter jejuni and the 16 phages used in the United Kingdom typing scheme by screening spontaneous mutants of the phage-type strains and transposon mutants of the sequenced strain NCTC 11168. We show that the 16 typing phages fall into four groups based on their patterns of activity against spontaneous mutants. Screens of transposon and defined mutants indicate that the phage-bacterium interaction for one of these groups appears to involve the capsular polysaccharide (CPS), while two of the other three groups consist of flagellatropic phages. The expression of CPS and flagella is potentially phase variable in C. jejuni, and the implications of these findings for typing and intervention strategies are discussed.     

Identification of a sulfonamide series of CCR2 antagonists

A series of sulfonamide CCR2 antagonists was identified by high-throughput screening. Management of molecular weight and physical properties, in particular moderation of lipophilicity and study of pK_a, yielded highly potent CCR2 antagonists exhibiting good pharmacokinetic properties and improved potency in the presence of human plasma.     

Alkanotrophic Rhodococcus ruber as a biosurfactant producer

In this report we examined the structure and properties of surface-active lipids of Rhodococcus ruber. Most historical interest has been in the glycolipids of Rhodococcus erythropolis, which have been extensively characterised. R. erythropolis has been of interest due to its great metabolic diversity. Only recently has the metabolic potential of R. ruber begun to be explored. One major difference in the two species is that most R. ruber strains are able to oxidise the gaseous alkanes propane and butane. In preparation for investigation of the effects of gas metabolism on biosurfactant production, we set out to characterise the biosurfactants produced during growth on liquid n-alkanes and to compare these with R. erythropolis glycolipids.     

Methods evaluating vanadium tolerance in bacteria isolated from crude oil contaminated land

Investigations into bacterial responses to vanadium are rare, and in this study were initiated by isolating cultures from crude oil contaminated soil from Russia and Saudi Arabia. Addition of vanadyl sulphate and vanadium pentoxide created acid conditions in the media whilst sodium metavanadate and sodium orthovanadate produced neutral and alkaline effects, respectively. Buffers were introduced for wider comparison of the sample set treatments and to distinguish between the effects of pH and compound toxicity. This study has resulted in the creation of protocols for the pH stabilisation of media containing vanadium compounds and revealed that, although vanadium salts demonstrated some toxic effects, as revealed by MIC and bioluminescence decay tests, the effects were mainly due to pH rather than inherent toxicity of the metal. Capacity for sorption of vanadium to biomass was also investigated.     

Kinesin-dependent axonal transport is mediated by the sunday driver (SYD) protein

A broadly conserved membrane-associated protein required for the functional interaction of kinesin-I with axonal cargo was identified. Mutations in sunday driver (syd) and the axonal transport motor kinesin-I cause similar phenotypes in Drosophila, including aberrant accumulations of axonal cargoes. GFP-tagged mammalian SYD localizes to tubulovesicular structures that costain for kinesin-I and a marker of the secretory pathway. Coimmunoprecipitation analysis indicates that mouse SYD forms a complex with kinesin-I in vivo. Yeast two-hybrid analysis and in vitro interaction studies reveal that SYD directly binds kinesin-I via the tetratricopeptide repeat (TPR) domain of kinesin light chain (KLC) with K(d) congruent with 200 nM. We propose that SYD mediates the axonal transport of at least one class of vesicles by interacting directly with KLC.     

Skeletal muscle myofibrillar protein metabolism in heart failure: relationship to immune activation and functional capacity

Chronic heart failure is characterized by changes in skeletal muscle that contribute to physical disability. Most studies to date have investigated defects in skeletal muscle oxidative capacity. In contrast, less is known about how heart failure affects myofibrillar protein metabolism. Thus we examined the effect of heart failure on skeletal muscle myofibrillar protein metabolism, with a specific emphasis on changes in myosin heavy chain (MHC) protein content, synthesis, and isoform distribution in 10 patients with heart failure (63 +/- 3 yr) and 11 controls (70 +/- 3 yr). In addition, we examined the relationship of MHC protein metabolism to inflammatory markers and physical function. Although MHC and actin protein content did not differ between groups, MHC protein content decreased with increasing disease severity in heart failure patients (r = -0.748, P < 0.02), whereas actin protein content was not related to disease severity. No difference in MHC protein synthesis was found between groups, and MHC protein synthesis rates were not related to disease severity. There were, however, relationships between C-reactive protein and both MHC protein synthesis (r = -0.442, P = 0.05) and the ratio of MHC to mixed muscle protein synthesis (r = -0.493, P < 0.03). Heart failure patients showed reduced relative amounts of MHC I (P < 0.05) and a trend toward increased MHC IIx (P = 0.06). In regression analyses, decreased MHC protein content was related to decreased exercise capacity and muscle strength in heart failure patients. Our results demonstrate that heart failure affects both the quantity and isoform distribution of skeletal muscle MHC protein. The fact that MHC protein content was related to both exercise capacity and muscle strength further suggests that quantitative alterations in MHC protein may have functional significance.