Characterisation of Aft1 a Fot1/Pogo type transposon of Aspergillus fumigatus

In recent years the filamentous fungus Aspergillus fumigatus has become a significant cause of infection in man and as such has become the focus of much study. It is thought to be the leading mould pathogen in leukaemia and transplant patients and is responsible for mortality in a large number of individuals with immunological disorders. In an attempt to develop molecular mutagenesis tools for assessment of this organism, the genome of A. fumigatus was analysed to identify possible functional transposable elements. An apparently intact Fot1/Pogo type transposon with 65% identity to the active Tan1 element of Aspergillus niger was identified and designated Aft1. Aft1 is a 1.9kb element present in multiple (>20) highly conserved copies. It encodes a 332 amino acid transposase which contains all the functional motifs required for transposition. In addition, the transposase was expressed in cultures grown at 37 degrees C in all three strains assessed and excision analysis suggests Aft1 may be active and of use in transposon tagging experiments. Southern hybridisation patterns indicate that Aft1 is widely distributed amongst clinical isolates of A. fumigatus with considerable variation in genomic localisation. A comprehensive analysis of the genomic localisation of Aft1 in the sequenced strain AF293 show that one insertion is 30 bases upstream of a predicted gene encoding a G-protein coupled receptor. Expression analysis indicates that this gene has been inactivated by the insertion.     

Canine model of nasal congestion and allergic rhinitis.

The ragweed- and histamine-induced decreases in nasal patency in cohorts of ragweed-sensitized and nonsensitized dogs were assessed. The volume of nasal airways (V(NA)) was assessed by acoustic rhinometry and resistance to airflow (R(NA)) by anterior rhinomanometry. Histamine delivered to the nasal passages of five dogs caused a rapid and prolonged increase in R(NA) (0.75 +/- 0.26 to 3.56 +/- 0.50 cmH(2)O. l(-1). min), an effect that was reversed by intranasal delivery of aerosolized phenylephrine. Ragweed challenge in five ragweed-sensitized dogs increased R(NA) from 0.16 +/- 0.02 to 0.53 +/- 0.07 cmH(2)O. l(-1). min and decreased V(NA) from 12.5 +/- 1.9 to 3.9 +/- 0.3 cm(3), whereas administration of saline aerosol neither increased R(NA) nor decreased V(NA). Prior administration of d-pseudoephedrine (30 mg po) attenuated the ragweed-induced increase in R(NA) and decrease in V(NA). Ragweed challenge changed neither R(NA) nor V(NA) in four nonsensitized dogs. Mediator-induced nasal congestion and allergen-induced allergic rhinitis in ragweed-sensitized dogs, which exhibit symptoms similar to human disease, can be used in the evaluation of safety and efficacy of antiallergic activity of potential drugs.     

The discovery of tropane derivatives as nociceptin receptor ligands for the management of cough and anxiety

The discovery of 1 as a high-affinity ligand for the nociceptin receptor has led to the synthesis of a series of tropane (8-methyl-8-azabicyclo[3.2.1]octane) derivatives as optimized ligands. These compounds exhibit high affinity for the nociceptin receptor, moderate to excellent selectivity over the opioid μ receptor, and behave as full agonists. In this Letter, we present the synthesis and highlight the structure–activity relationship of tropane derivatives culminating in the identification of 24 and 32 as potent and orally active antitussive and anxiolytic agents. The in vitro and in vivo activities, pharmacokinetic profile, and the hPXR activity, which predicts the potential 3A4 induction in human, are disclosed.     

Non-equilibrium allele frequency spectra via spectral methods

A major challenge in the analysis of population genomics data consists of isolating signatures of natural selection from background noise caused by random drift and gene flow. Analyses of massive amounts of data from many related populations require high-performance algorithms to determine the likelihood of different demographic scenarios that could have shaped the observed neutral single nucleotide polymorphism (SNP) allele frequency spectrum. In many areas of applied mathematics, Fourier Transforms and Spectral Methods are firmly established tools to analyze spectra of signals and model their dynamics as solutions of certain Partial Differential Equations (PDEs). When spectral methods are applicable, they have excellent error properties and are the fastest possible in high dimension; see Press et al. (2007). In this paper we present an explicit numerical solution, using spectral methods, to the forward Kolmogorov equations for a Wright–Fisher process with migration of K populations, influx of mutations, and multiple population splitting events.     

Identification of EBV-DNA in lymph nodes from patients with lymphadenopathy and lymphomas associated with AIDS

Fourteen examples of non-Hodgkin's lymphoma (NHL) and four of Hodgkin's disease in patients with AIDS as well as lymph nodes exhibiting changes related to the lymphadenopathy syndrome (LAS) from 11 HIV-positive individuals were studied for the presence of Epstein-Barr virus (EBV) genome both by in situ DNA hybridization and blotting techniques. Both methods were performed using formalin-fixed paraffin-embedded material. All the NHLs were of high malignancy and all but one were of the B-cell type. Of the four examples of Hodgkin's disease, two were lymphocytic predominant, one of mixed cellularity and one of the nodular sclerosing variety. The lymph nodes of patients with LAS were mostly stage I with marked follicular hyperplasia. In 7 of the 14 NHLs the presence of EBV-DNA was clearly demonstrated by dot-blotting and by in situ hybridization. All lymph nodes from the patients with LAS and AIDS-related Hodgkin's disease were negative for EBV by dot-blot and in situ hybridization assays. We conclude that EBV plays a role in the development of AIDS-related lymphomas, but the fact that half these lymphomas are EBV-negative suggests that other mechanisms such as polyclonal stimulation of B-cells by HIV products may also be important.     

Metabolic signalling and carbon partitioning: role of Snf1-related (SnRK1) protein kinase

A protein kinase that plays a key role in the global control of plant carbon metabolism is SnRK1 (sucrose non-fermenting-1-related protein kinase 1), so-called because of its homology and functional similarity with sucrose non-fermenting 1 (SNF1) of yeast. This article reviews studies on the characterization of SnRK1 gene families, SnRK1 regulation and function, interacting proteins, and the effects of manipulating SnRK1 activity on carbon metabolism and development.     

A stable meta‐carborane enables the generation of boron‐rich peptide agonists targeting the ghrelin receptor

Boron neutron capture therapy (BNCT) is a binary cancer therapy, which combines the biochemical targeting of a boron‐containing drug with the regional localization of radiation treatment. Although the concept of BNCT has been known for decades, the selective delivery of boron into tumor cells remains challenging. G protein‐coupled receptors that are overexpressed on cancer cells in combination with peptidic ligands can be potentially used as shuttle system for a tumor‐directed boron uptake. In this study, we present the generation of short, boron‐rich peptide conjugates that target the ghrelin receptor. Expression of the ghrelin receptor on various cancer cells makes it a viable target for BNCT. We designed a novel hexapeptide super‐agonist that was modified with different specifically synthesized carborane monoclusters and tested for ghrelin receptor activation. A meta‐carborane building block with a mercaptoacetic acid linker was found to be optimal for peptide modification, owing to its chemical stability and a suitable activation efficacy of the conjugate. The versatility of this carborane for the development of peptidic boron delivery agents was further demonstrated by the generation of highly potent, boron‐loaded conjugates using the backbone of the known ghrelin receptor ligands growth hormone releasing peptide 6 and Ipamorelin.