Stimulation of prostaglandin-dependent macrophage suppressor cells by the subcutaneous injection of polyunsaturated fatty acids

Polyunsaturated fatty acids (PUFAs), in the form of pure linoleic, linolenic, or arachidonic acid, were injected subcutaneously into male C57Bl/6 mice daily for 10 days. Injection of 3.6 mg/day of PUFA resulted in up to a two- to threefold increase in spleen weight. Spleen cell response to mitogens was reduced by about 70%; mixed lymphocyte responses were reduced by about 90% when compared to normal values. In admixture experiments, spleen cells from PUFA treated mice suppressed the mitogen induced blastogenic response of control spleen cells by up to 90%. Fractionation of spleen cells from PUFA treated mice by G-10 adherence resulted in an enrichment of suppressive activity in the adherent cells. The suppressive effect of G-10 adherent cells was abolished by the addition of indomethacin as well as by depletion of macrophages by treatments with agents such as carbonyl iron and leucine methyl ester. These studies indicate that the administration of PUFA has marked immunosuppressive effects in mice. These effects may be related to increased prostaglandin production and appear to be mediated by a macrophage type cell.     

Helicobacter Hypothesis for Idiopathic Parkinsonism: Before and Beyond

We challenge the concept of idiopathic parkinsonism (IP) as inevitably progressive neurodegeneration, proposing a natural history of sequential microbial insults with predisposing host response. Proof-of-principle that infection can contribute to IP was provided by case studies and a placebo-controlled efficacy study of Helicobacter eradication. "Malignant" IP appears converted to "benign", but marked deterioration accompanies failure. Similar benefit on brady/hypokinesia from eradicating "low-density" infection favors autoimmunity. Although a minority of UK probands are urea breath test positive for Helicobacter , the predicted probability of having the parkinsonian label depends on the serum H. pylori antibody profile, with clinically relevant gradients between this "discriminant index" and disease burden and progression. In IP, H. pylori antibodies discriminate for persistently abnormal bowel function, and specific abnormal duodenal enterocyte mitochondrial morphology is described in relation to H. pylori infection. Slow intestinal transit manifests as constipation from the prodrome. Diarrhea may flag secondary small-intestinal bacterial overgrowth. This, coupled with genetically determined intense inflammatory response, might explain evolution from brady/hypokinetic to rigidity-predominant parkinsonism.     

High-school students in university research labs? Implementing an outreach model based on the ‘science as inquiry’ approach

In this study we designed, implemented, and evaluated an outreach programme for high-school biology students rooted in the ‘science as inquiry’ approach. Accordingly, students learn about science from experts in the field, as well as through in-class exposure to the history and philosophy of science. Our sample consisted of 11th graders (n?=?497), ages 16–17, attending advanced biology classes. Our goal was to determine whether this programme had a significant effect on students’ understanding of the ‘nature of science’ (NOS) and on their attitudes towards science. Using a controlled pre-post research design, we asked participants to complete a Likert-like questionnaire. Also, we conducted post-programme semi-structured interviews with 35 of the participants. Results show that completion of the programme significantly enhanced participants’ NOS understanding and improved their attitudes towards science. Participants expressed a deep level of NOS understanding and explicitly stated that the field visits to experts’ labs had changed their attitude towards science. We believe that our outreach programme can be adapted for teaching other sciences and for societies worldwide, as long as there is access to university laboratories and researchers willing to interact with young citizens and potential future scientists.     

Expression of engrailed proteins in arthropods, annelids, and chordates

engrailed is a homeobox gene that has an important role in Drosophila segmentation. Genes homologous to engrailed have been identified in several other organisms. Here we describe a monoclonal antibody that recognizes a conserved epitope in the homeodomain of engrailed proteins of a number of different arthropods, annelids, and chordates; we use this antibody to isolate the grasshopper engrailed gene. In Drosophila embryos, the antibody reveals engrailed protein in the posterior portion of each segment during segmentation, and in a segmentally reiterated subset of neuronal cells during neurogenesis. Other arthropods, including grasshopper and two crustaceans, have similar patterns of engrailed expression. However, these patterns of expression are not shared by the annelids or chordates we examined. Our results provide the most comprehensive view that has been obtained of how expression patterns of a regulatory gene vary during evolution. On the basis of these patterns, we suggest that engrailed is a gene whose ancestral function was in neurogenesis and whose function was co-opted during the evolution of segmentation in the arthropods, but not in the annelids and chordates.     

A Novel Approach to Recovery of Function of Mutant Proteins by Slowing Down Translation

Protein homeostasis depends on a balance of translation, folding, and degradation. Here, we demonstrate that mild inhibition of translation results in a dramatic and disproportional reduction in production of misfolded polypeptides in mammalian cells, suggesting an improved folding of newly synthesized proteins. Indeed, inhibition of translation elongation, which slightly attenuated levels of a copepod GFP mutant protein, significantly enhanced its function. In contrast, inhibition of translation initiation had minimal effects on copepod GFP folding. On the other hand, mild suppression of either translation elongation or initiation corrected folding defects of the disease-associated cystic fibrosis transmembrane conductance regulator mutant F508del. We propose that modulation of translation can be used as a novel approach to improve overall proteostasis in mammalian cells, as well as functions of disease-associated mutant proteins with folding deficiencies.     

Heteroaryl urea inhibitors of fatty acid amide hydrolase: Structure–mutagenicity relationships for arylamine metabolites

The structure–activity relationships for a series of heteroaryl urea inhibitors of fatty acid amide hydrolase (FAAH) are described. Members of this class of inhibitors have been shown to inactivate FAAH by covalent modification of an active site serine with subsequent release of an aromatic amine from the urea electrophile. Systematic Ames II testing guided the optimization of urea substituents by defining the structure–mutagenicity relationships for the released aromatic amine metabolites. Potent FAAH inhibitors were identified having heteroaryl amine leaving groups that were non-mutagenic in the Ames II assay.     

Kinetics of juvenile sea bass (Dicentrarchus labrax, L.) systemic and mucosal antibody secreting cell response to different antigens (Photobacterium damselae spp. piscicida, Vibrio anguillarum and DNP).

The ELISPOT assay was used to measure the number of specific antibody secreting cells (ASC) induced during the primary and secondary immune responses in the spleen, head kidney and gut of juvenile (5 g) sea bass (Dicentrarchus labrax) to bacterial (Vibrio anguillarum and Photobacterium damselae ssp. piscicida) and hapten dinitrophenyl-conjugated to keyhole limpet haemocyanin (DNP-KLH) antigens administered intraperitoneally. High variability among individuals was observed at each sampling day. All fish were bath vaccinated to V. anguillarum at an earlier stage (2 g) in the farm of origin prior to the development of the experiments, and therefore only secondary and tertiary responses were measured in the group immunised with this bacterium. Significant differences to the controls were observed in the primary responses of the head kidney and the spleen to P. damselae ssp. piscicida and DNP, respectively. Frequency analysis of the production of ASC suggests that significant responses in the gut might be masked by the high error variance. The peak of the primary response was observed 4 days earlier to DNP (18-20 days post-immunisation) and it was significantly higher than the response to P. damselae ssp. piscicida. Higher numbers of ASC were observed in the secondary responses of the head kidney and spleen, although they were not statistically significantly different from the primary levels, probably due to the high error variance as supported by the frequency analysis. Nevertheless, together with a faster response (peak at 7 days post-immunisation), the data suggest that memory formation had occurred. Additionally, the data suggest that some suppression of the secondary immune response in the gut might have occurred. The head kidney appears to produce the highest number of specific ASC of the organs tested. It appears that sea bass show a relatively fast but short duration antibody response.     

Septation and chromosome segregation during sporulation in Bacillus subtilis

The early stages of sporulation in Bacillus subtilis incorporate a modified, highly asymmetric cell division. It is now clear that most, if not all, of the components of the vegetative division machinery are used also for asymmetric division. However, the machinery for chromosome segregation may differ significantly between vegetative growth and sporulation. Several interesting checkpoint mechanisms couple cell cycle events to gene expression early in sporulation. This review summarises important advances in the understanding of chromosome segregation and cell division at the onset of sporulation in B.subtilis in the past three years.