A rhodanine agent active against non-replicating intracellular Mycobacterium avium subspecies paratuberculosis.

BACKGROUND: Antibiotic therapy targeting chronic mycobacterial disease is often ineffective due to problems with the emergence of drug resistance and non-replicating persistent intracellular antibiotic resistant phenotypes. Strategies which include agents able to enhance host cell killing mechanisms could represent an alternative to conventional methods with the potential for host clearance if active against dormant phenotypes. Investigations of agents with potential activity against non-replicating mycobacteria however are restricted due to a need for assays that can assess bacterial viability without having to culture. RESULTS: This study describes the development and use of a pre16S ribosomal gene RNA/DNA ratio viability assay which is independent of the need for culture, supported by a novel thin layer accelerated mycobacterial colony forming method for determining viability and culturability of MAP in intracellular environments. We describe the use of these tools to demonstrate intracellular killing activity of a novel rhodanine agent (D157070) against the intracellular pathogen Mycobacterium avium subspecies paratuberculosis (MAP) and show that the culturability of MAP decreases relative to its viability on intracellular entry suggesting the induction of a non-culturable phenotype. We further demonstrate that D157070, although having no direct activity against the culturability of extracellular MAP, can bind to cultured MAP cells and has significant influence on the MAP transcriptome, particularly with respect of delta(L )associated genes. D157070 is shown to be taken up by bovine and human cells and able to enhance host cell killing, as measured by significant decreases in both culturability and viability of intracellular MAP. CONCLUSIONS: This work suggests that pre16srRNA gene ratios represent a viable method for studying MAP viability. In addition, the rhodanine agent D157070 tested is non-toxic and enhances cell killing activity against both growing and latent MAP phenotypes

Microphytobenthic extracellular polymeric substances (EPS) in intertidal sediments fuel both generalist and specialist EPS-degrading bacteria

Microphytobenthic biofilms contain high concentrations of carbohydrate-rich extracellular polymeric substances (EPS) that are important in sediment carbon cycling. Field measurements at two locations in the Colne Estuary, U.K., showed that a significant curvilinear relationship explained 50% of the variability in chlorophyll a and EPS content. Estimates of EPS production, based on field data and published rates of production by diatoms, revealed that EPS turnover of 52% to 369% over the tidal cycle was required to account for field standing stocks. We investigated EPS degradation in sediment slurries using purified 13C-EPS produced by the diatom Nitzschia tubicola. Although EPS constituted only 5% of the sediment dissolved organic carbon (DOC) pool, 100% of the added EPS was utilized within 30 h, before decreases in other sediment-carbohydrate fractions and DOC concentrations. A general 13C enrichment of phospholipid fatty acids (PLFAs), representative of Gram-positive and Gram-negative bacteria, occurred within 6 h, with the PLFAs a15:0, i15:0, and 18:1?7c being highly enriched. The diatom PLFA 20:5?3 had relatively low but significant 13C enrichment. Stable isotope probing of 16S ribosomal ribonucleic acid (RNA-SIP) at 30 h revealed 13C-enriched sequences from the diatom genus Navicula; further evidence that diatoms assimilated the EPS, or EPS-breakdown products, from other diatom taxa. RNA-SIP also demonstrated a diverse range of highly 13C-enriched bacterial taxa, including a distinct subset (Alphaproteobacteria and Gammaproteobacteria) found only in the heavily labeled microbial assemblages. Thus, cycling of diatom EPS is rapid, and involves a wide range of microbial taxa, including some apparent specialists

Stochastic user behaviour modelling and network simulation for resource management in cooperation with mobile telecommunications and broadcast networks

The latest generations of telecommunications networks have been designed to deliver higher data rates than widely used second generation telecommunications networks, providing flexible communication capabilities that can deliver high quality video images. However, these new generations of telecommunications networks are interference limited, impairing their performance in cases of heavy traffic and high usage. This limits the services offered by a telecommunications network operator to those that the operator is confident their network can meet the demand for. One way to lift this constraint would be for the mobile telecommunications network operator to obtain the cooperation of a broadcast network operator so that during periods when the demand for the service is too high for the telecommunications network to meet, the service can be transferred to the broadcast network. In the United Kingdom the most recent telecommunications networks on the market are third generation UMTS networks while the terrestrial digital broadcast networks are DVB-T networks. This paper proposes a way for UMTS network operators to forecast the traffic associated with high demand services intended to be deployed on the UMTS network and when demand requires to transfer it to a cooperating DVB-T network. The paper aims to justify to UMTS network operators the use of a DVB-T network as a support for a UMTS network by clearly showing how using a DVB-T network to support it can increase the revenue generated by their network

Uncertainty in climate change impacts on basin-scale freshwater resources – preface to the special issue: the QUEST-GSI methodology and synthesis of results

This paper presents a preface to this Special Issue on the results of the QUEST-GSI (Global Scale Impacts) project on climate change impacts on catchment-scale water resources. A detailed description of the unified methodology, subsequently used in all studies in this issue, is provided. The project method involved running simulations of catchment-scale hydrology using a unified set of past and future climate scenarios, to enable a consistent analysis of the climate impacts around the globe. These scenarios include "policy-relevant" prescribed warming scenarios. This is followed by a synthesis of the key findings. Overall, the studies indicate that in most basins the models project substantial changes to river flow, beyond that observed in the historical record, but that in many cases there is considerable uncertainty in the magnitude and sign of the projected changes. The implications of this for adaptation activities are discussed

Factors determining short- and long-term survival after orthotopic liver homotransplantation in the dog

Without azathioprine therapy, the operative risk with orthotopic liver transplantation is small. Twenty-two of 23 animals survived 2 days or more, and 19 for 6 days or longer. All eventually died of rejection within 10 days. Changes in homograft histology and function were similar to those previously reported, with cellular infiltration and hepatocyte necrosis which was heavily concentrated in the centrilobular areas. In individual experiments, there was little evidence of immunologically induced segmental hepatic arterial or portal venous occlusion; hepatocyte loss was homogeneous, and fibrinoid vascular lesions were uncommon. There was, however, some evidence of damage to the sinusoidal endothelium by adherent mononuclear cells. The changing character of the mononuclear infiltration of the homograft was reflected by widespread proliferation of similar cells in the host lymphoid tissue. Specific changes in other host organs were not noted. Some of the biochemical and histologic alterations caused by unmodified rejection can also be produced by azathioprine. In 18 nontransplanted dogs, acute rises in SGOT, SGPT, and alkaline phosphatase, unaccompanied by hyperbilirubinemia, were noted within a few days after beginning administration of this agent. Although these abnormalities tended to regress within the 40 day period of observation, more than two thirds of the livers showed histologic evidence of centrilobular hepatocyte damage or necrosis-often with intrahepatic cholestasis, but always without mononuclear cell infiltration. The hepatotoxicity was not prevented by methionine. Weight loss and progressive anemia also occurred. Lymphoid tissue was depleted. The mortality from the toxicity study was 33 percent. The use of azathioprine to mitigate rejection increased the early mortality after homotransplantation, 32 of 116 dogs dying within the first week (28 percent), most commonly of pulmonary complications. The 84 animals living longer than 7 days had a greatly potentiated homograft survival, exceeding 25 days in 44 dogs, and 50 days in 24. Fifteen animals are still alive from 62 to 324 days postoperatively. Six dogs had all drugs stopped after 116 to 123 days. Only 1 has had a clinically evident late rejection and 5 are still alive from 63 to 204 days later. Three of these animals had repeat biopsies 77 to 182 days after cessation of therapy; one homograft which was normal at 4 months remained so 6 months later, another had an improved histologic appearance, and the third had deteriorated. The longest mean survival was in those animals receiving adjuvant therapy with L-methionine or S35-methionine, but the variability of the results was so great that a statistically significant advantage of these agents could not be demonstrated. Soon after operation red cell survival was decreased, but in chronic survivors there was no evidence of a grafthost reaction. There was great variability in the vigor of rejection, ranging from the uncontrollable (29 percent) to the clinically undetectable (23 percent). Most of the animals (49 percent) had some biochemical evidence of rejection which proved to be spontaneously reversible, to a greater or lesser degree, since intensification of immunosuppressive therapy was not required. These findings correlate well with the histologic studies. In virtually all animals, azathioprine delayed the onset of rejection but in those dying in the second and third postoperative weeks, the pathologic stigmas of rejection were very similar to the untreated controls. As in the untreated animals, the number of proliferating large pyroninophilic cells in the host's lymphoid tissues was roughly proportional to the number of mononuclear cells invading the homograft liver. After this time, the predominant histologic features in most animals were those of repair and regeneration, with either absent or relatively minor degrees or continuing destruction. Since the major rejection damage was centrizonal, the healing was most prominent in these areas with interconecting fibrosis around the central veins, centrilobular bile canalicular dilatation and cholestasis, and pseudolobule formation. In some of the homografts, increased connective tissue was also present in the portal tracts, but in others including the longest survivor there were no residual abnormalities whatever. In azathioprine-treated animals, damage to the vessels in the homograft portal tracts was found in only one liver. With electron microscopy there was some evidence of damage to the sinusoidal endothelium by adherent mononuclear cells, a finding which could be analogous to that described by Kountz and co-workers11 in the peritubular capillaries of renal homografts. If immunologically mediated hemodynamic alterations play an important role in liver homograft rejection by interrupting the blood supply to the hepatocytes, it seems most likely that they occur at this intrasinusoidal capillary level rather than in the larger vessels. © 1965

Molecular and phenotypic description of Coccidioides Posadasii sp nov., previously recognized as the non-California population of Coccidioides immitis

Coccidioides posadasii sp. nov., formerly known as non-California (non-CA) Coccidioides immitis, is described. Phylogenetic analyses using single nucleotide polymorphisms, genes, and microsatellites show that C. posadasii represents a divergent, genetically recombining monophyletic clade. Coccidioides posadasii can be distinguished from C. immitis by numerous DNA polymorphisms, and we show how either of two microsatellite loci may be used as diagnostic markers for this species. Growth experiments show that C. posadasii has significantly slower growth rates on high-salt media when compared with C. immitis, suggesting that other phenotypic characters may exist.Published versio

Structural Change for a Post-Growth Economy: Investigating the Relationship between Embodied Energy Intensity and Labour Productivity

Post-growth economists propose structural changes towards labour-intensive services, such as care or education, to make our economy more sustainable by providing meaningful work and reducing the environmentally damaging production of material goods. Our study investigates the assumption underlying such proposals. Using a multi-regional input-output model we compare the embodied energy intensity and embodied labour productivity across economic sectors in the UK and Germany between 1995 and 2011. We identify five labour-intensive service sectors, which combine low embodied energy intensity with low growth in embodied labour productivity. However, despite their lower embodied energy intensities, our results indicate that large structural changes towards these sectors would only lead to small reductions in energy footprints. Our results also suggest that labour-intensive service sectors in the UK have been characterised by higher rates of price inflation than other sectors. This supports suggestions from the literature that labour-intensive services face challenges from increasing relative prices and costs. We do not find similar results for Germany, which is the result of low overall growth in embodied labour productivity and prices. This highlights that structural change is closely associated with economic growth, which raises the question of how structural changes can be achieved in a non-growing economy

Re: the role of radiology in anatomy teaching in UK medical schools: a national survey. A reply.

Sir – We thank Raja and colleagues1 for their interest in our article and share their enthusiasm for the integration of radiology in anatomy teaching. This is something that we feel passionate about. Two of our authors are full-time practicing consultant radiologists with additional roles as medical educators in anatomy teaching at the University of Cambridge medical school