Phylogenetic Evidence for Two New Insect-Associated Chlamydia of the Family <Emphasis Type="Italic">Simkaniaceae</Emphasis>

On the basis of 16S–23S ribosomal DNA analyses, the whitefly Bemisia tabaci (Sternorrhyncha, Aleyrodidae) and the eriococcid Eriococcus spurius (Sternorrhyncha, Eriococcidae) were each found to harbor novel related chlamydial species within the family Simkaniaceae. The generic designation Fritschea gen. nov. is proposed to accommodate the two species, F. bemisiae sp. nov. and F. eriococci sp. nov. The finding of chlamydial 16S–23S ribosomal DNA in B. tabaci is consistent with a previous electron microscopy study which found that bacteriocytes of this species contain structures that we consider to resemble the elementary and reticulate bodies of chlamydia (Costa HS, Westcot DM, Ullman DE, Rosell R, Brown JK, Johnson MW. Protoplasma 189:194–202, 1995). The cloning and sequencing of a 16.6 kilobase DNA fragment from F. bemisiae indicated that it contains six genes encoding for proteins similar to those found in other species of chlamydia. These results extend the range of organisms that harbor chlamydia. Received: 27 August 2002 / Accepted: 4 September 2002     

Structure,fluctuation and magnitude of a natural grassland soil metagenome

The soil ecosystem is critical for human health, affecting aspects of the environment from key agricultural and edaphic parameters to critical influence on climate change. Soil has more unknown biodiversity than any other ecosystem. We have applied diverse DNA extraction methods coupled with high throughput pyrosequencing to explore 4.88 × 10⁹ bp of metagenomic sequence data from the longest continually studied soil environment (Park Grass experiment at Rothamsted Research in the UK). Results emphasize important DNA extraction biases and unexpectedly low seasonal and vertical soil metagenomic functional class variations. Clustering-based subsystems and carbohydrate metabolism had the largest quantity of annotated reads assigned although <50% of reads were assigned at an E value cutoff of 10⁻⁵. In addition, with the more detailed subsystems, cAMP signaling in bacteria (3.24±0.27% of the annotated reads) and the Ton and Tol transport systems (1.69±0.11%) were relatively highly represented. The most highly represented genome from the database was that for a Bradyrhizobium species. The metagenomic variance created by integrating natural and methodological fluctuations represents a global picture of the Rothamsted soil metagenome that can be used for specific questions and future inter-environmental metagenomic comparisons. However, only 1% of annotated sequences correspond to already sequenced genomes at 96% similarity and E values of <10⁻⁵, thus, considerable genomic reconstructions efforts still have to be performed.     

The ‘Swallow Tail’ Appearance of the Healthy Nigrosome – A New Accurate Test of Parkinson's Disease: A Case-Control and Retrospective Cross-Sectional MRI Study at 3T

There is no well-established in vivo marker of nigral degeneration in Parkinson''s disease (PD). An ideal imaging marker would directly mirror the loss of substantia nigra dopaminergic neurones, which is most prominent in sub-regions called nigrosomes. High-resolution, iron-sensitive, magnetic resonance imaging (MRI) at 7T allows direct nigrosome-1 visualisation in healthy people but not in PD. Here, we investigated the feasibility of nigrosome-1 detection using 3T - susceptibility-weighted (SWI) MRI and the diagnostic accuracy that can be achieved for diagnosing PD in a clinical population. 114 high-resolution 3T – SWI-scans were reviewed consisting of a prospective case-control study in 19 subjects (10 PD, 9 controls) and a retrospective cross-sectional study in 95 consecutive patients undergoing routine clinical SWI-scans (>50 years, 9 PD, 81 non-PD, 5 non-diagnostic studies excluded). Two raters independently classified subjects into PD and non-PD according to absence or presence of nigrosome-1, followed by consensus reading. Diagnostic accuracy was assessed against clinical diagnosis as gold standard. Absolute inter- and intra-rater agreement was ≥94% (kappa≥0.82, p<0.001). In the prospective study 8/9 control and 8/10 PD; and in the retrospective study 77/81 non-PD and all 9 PD subjects were correctly classified. Diagnostic accuracy of the retrospective cohort was: sensitivity 100%, specificity 95%, NPV 1, PPV 0.69 and accuracy 96% which dropped to 91% when including non-diagnostic scans (‘intent to diagnose’). The healthy nigrosome-1 can be readily depicted on high-resolution 3T - SWI giving rise to a ‘swallow tail’ appearance of the dorsolateral substantia nigra, and this feature is lost in PD. Visual radiological assessment yielded a high diagnostic accuracy for PD vs. an unselected clinical control population. Assessing the substantia nigra on SWI for the typical ‘swallow tail’ appearance has potential to become a new and easy applicable 3T MRI diagnostic tool for nigral degeneration in PD.     

Sex-specific extraction of organic anions by the rat liver

The capacity for hepatic elimination of some compounds is different in males and females and differential expression of a number of sinusoidal and canalicular transporters exists. However, the specific events underlying the functional differences are not understood. To determine how sex influences sinusoidal and canalicular organic anion transport, bile duct-cannulated livers from mature Sprague-Dawley rats of both sexes were single-pass perfused with saline containing the model organic anions bromosulphophthalein (BSP), carboxyfluorescein (CF), carboxyfluorescein diacetate (CFDA) or 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS). Assay of effluent perfusate anion concentration showed that BSP, but not DIDS, extraction was significantly higher in male versus female rats. At 20 min perfusion with 50 microM BSP the mean effluent concentration was 5.6 and 20.1 microM in, respectively, male and female rats. HPLC confirmed that the effluent perfusate concentration of BSP was higher in female as compared with male rats and was not contributed to by its glutathione conjugate. With 25 microM DIDS, the effluent concentration reached 7.3 (male) and 8.2 microM (female), indicating high extraction efficiency. In contrast to BSP and DIDS, CF extraction was very low (<20%) so that differences between male and females could not be assessed. Biliary BSP and CF excretion were, respectively, 3.5- and 4-fold higher in male rats. Neither sinusoidal efflux nor biliary excretion of CF was sex-dependent with a higher cytoplasmic load of CF (during CFDA perfusion). Our results suggest that differences in sinusoidal uptake are responsible for the sex-specific hepatic excretion of some organic anions.     

Biphenyl amide p38 kinase inhibitors 4: DFG-in and DFG-out binding modes

The biphenyl amides (BPAs) are a series of p38α MAP kinase inhibitors. Compounds are able to bind to the kinase in either the DFG-in or DFG-out conformation, depending on substituents. X-ray, binding, kinetic and cellular data are shown, providing the most detailed comparison to date between potent compounds from the same chemical series that bind to different p38α conformations. DFG-out-binding compounds could be made more potent than DFG-in-binding compounds by increasing their size. Unexpectedly, compounds that bound to the DGF-out conformation showed diminished selectivity. The kinetics of binding to the isolated enzyme and the effects of compounds on cells were largely unaffected by the kinase conformation bound.     

Synthesis and biological activity of anticoccidial agents: 5,6-diarylimidazo[2,1-b][1,3]thiazoles

Novel 5,6-diarylimidazo[2,1-b][1,3]thiazoles bearing an amine substituent at the imidazothiazole 2-position have been synthesized and evaluated as anticoccidial agents in both in vitro and in vivo assays. Both subnanomolar in vitro activity and broad spectrum in vivo potency were detected for several compounds, particularly compound 10.     

Report of the 2006 RSPCA/UFAW Rodent Welfare Group meeting

The RSPCA/UFAW Rodent Welfare Group holds a one-day meeting every autumn to discuss current welfare research and to exchange views on rodent welfare issues. A key aim of the group is to encourage people to think about the lifetime experience of laboratory rodents, ensuring that every potential influence on their well-being has been reviewed and refined. Speakers at the 2006 meeting presented preliminary findings of ongoing studies and discussed regulatory updates. Topics included the housing and husbandry of mice and rats, refining the use of rodents in asthma research, good practice for the euthanasia of rodents using carbon dioxide and achieving reduction by sharing genetically modified mice.     

Exploitation of endophytes for sustainable agricultural intensification

Intensive agriculture, which depends on unsustainable levels of agrochemical inputs, is environmentally harmful, and the expansion of these practices to meet future needs is not economically feasible. Other options should be considered to meet the global food security challenge. The plant microbiome has been linked to improved plant productivity and, in this microreview, we consider the endosphere – a subdivision of the plant microbiome. We suggest a new definition of microbial endophyte status, the need for synergy between fungal and bacterial endophyte research efforts, as well as potential strategies for endophyte application to agricultural systems.