Research into the (Cost-) effectiveness of the ketogenic diet among children and adolescents with intractable epilepsy: design of a randomized controlled trial

Background  

Epilepsy is a neurological disorder, characterized by recurrent unprovoked seizures which have a high impact on the individual as well as on society as a whole. In addition to the economic burden, epilepsy imposes a substantial burden on the patients and their surroundings. Patients with uncontrolled epilepsy depend heavily on informal care and on health care professionals. About 30% of patients suffer from drug-resistant epilepsy. The ketogenic diet can be a treatment of last resort, especially for children. The beneficial effect of the ketogenic diet has been proven, but information is lacking about its cost-effectiveness. In the current study we will evaluate the (cost-) effectiveness of the ketogenic diet in children and adolescents with intractable epilepsy.     

Differential effects of age,cytomegalovirus-seropositivity and end-stage renal disease (ESRD) on circulating T lymphocyte subsets

The age- and cytomegalovirus (CMV)-seropositivity-related changes in subsets and differentiation of circulating T cells were investigated in end-stage renal disease (ESRD) patients (n = 139) and age-matched healthy individuals. The results show that CMV-seropositivity is associated with expansion of both CD4⁺ and CD8⁺ memory T cells which is already observed in young healthy individuals. In addition, CMV-seropositive healthy individuals have a more differentiated memory T cell profile. Only CMV-seropositive healthy individuals showed an age-dependent decrease in CD4⁺ naïve T cells. The age-related decrease in the number of CD8⁺ naïve T cells was CMV-independent. In contrast, all ESRD patients showed a profound naïve T-cell lymphopenia at every decade. CMV-seropositivity aggravated the contraction of CD4⁺ naïve T cells and increased the number of differentiated CD4⁺ and CD8⁺ memory T cells. In conclusion, CMV-seropositivity markedly alters the homeostasis of circulating T cells in healthy individuals and aggravates the T cell dysregulation observed in ESRD patients.     

BetaSearch: a new method for querying beta-residue motifs

ABSTRACT: BACKGROUND: Searching for structural motifs across known protein structures can be useful for identifying unrelated proteins with similar function and characterising secondary structures such as beta-sheets. This is infeasible using conventional sequence alignment because linear protein sequences do not contain spatial information. beta-residue motifs are beta-sheet substructures that can be represented as graphs and queried using existing graph indexing methods, however, these approaches are designed for general graphs that do not incorporate the inherent structural constraints of beta-sheets and require computationally-expensive filtering and verification procedures. 3D substructure search methods, on the other hand, allow beta-residue motifs to be queried in a three-dimensional context but at significant computational costs. RESULTS: We developed a new method for querying beta-residue motifs, called BetaSearch, which leverages the natural planar constraints of beta-sheets by indexing them as 2D matrices, thus avoiding much of the computational complexities involved with structural and graph querying. BetaSearch demonstrates faster filtering, verification, and overall query time than existing graph indexing approaches whilst producing comparable index sizes. Compared to 3D substructure search methods, BetaSearch achieves 33 and 240 times speedups over index-based and pairwise alignment-based approaches, respectively. Furthermore, we have presented case-studies to demonstrate its capability of motif matching in sequentially dissimilar proteins and described a method for using BetaSearch to predict beta-strand pairing. CONCLUSIONS: We have demonstrated that BetaSearch is a fast method for querying substructure motifs. The improvements in speed over existing approaches make it useful for efficiently performing high-volume exploratory querying of possible protein substructural motifs or conformations. BetaSearch was used to identify a nearly identical beta-residue motif between an entirely synthetic (Top7) and a naturally-occurring protein (Charcot-Leyden crystal protein), as well as identifying structural similarities between biotin-binding domains of avidin, streptavidin and the lipocalin gamma subunit of human C8. AVAILABILITY: The web-interface, source code, and datasets for BetaSearch can be accessed from http://www.csse.unimelb.edu.au/~hohkhkh1/betasearch.     

Differential effects of foliar endophytic fungi on insect herbivores attacking a herbaceous plant

Foliar endophytic fungi appear to be ubiquitous in nature, occurring in a very wide range of herbaceous plants. However, their ecological role within forbs is very poorly known and interactions with foliar-feeding insects virtually unexplored. In this study, leaves of Cirsium arvense were infected with different combinations of endophyte fungi that had been previously isolated from this plant species. Two months later, leaf material was fed to larvae of a generalist insect, Mamestra brassicae, and adults of a specialist feeder, Cassida rubiginosa. Endophytes had different effects on the two insects; one species, Chaetomium cochliodes, reduced growth of M. brassicae but increased feeding by C. rubiginosa. Another species, Cladosporium cladosporioides, increased beetle feeding also, but had no effect on M. brassicae. Interactions were also seen between fungal species and dual infection with C. cladosporioides and Trichoderma viride greatly reduced beetle feeding. It is concluded that endophytes have significant effects on foliar feeding insects that differ with degree of specialism of the herbivore. We suggest that these effects are due to chemical changes in the host, brought about by fungal infection. These fungi have received remarkably little attention in the study of insect–plant interactions and yet could be important determinants of insect growth and even population dynamics.     

Influence of pasture management (nitrogen and lime addition and insecticide treatment) on soil organisms and pasture root system dynamics in the field

At an upland field site in Scotland on an established Festuca-Agrostis pasture, the effects of soil amendment on root dynamics, using nitrogen and lime and the regular application of insecticide, were studied over a period of 1 year. The most common insect root herbivore at the site was Tipula paludosa, and the application of insecticide (chlorpyrifos) reduced numbers of all insect larvae of all species. Root biomass, root appearance, root disappearance and root density were all reduced by insecticide. This reduced rooting could reflect reduced root replacement, due to the reduction in root herbivory in insecticide-treated plots or could be a direct affect of insecticide application on the roots. Root appearance, root disappearance and C and N input to the soil were increased by treatment with nitrogen and lime, while root survival time was reduced. The nitrogen and lime treatment also increased bacterial numbers in the soil and enhanced their potential C utilization. An altered rooting density and longevity was brought about by the two soil treatments, which could have both direct and indirect effects on the soil biota.     

Novel non-viral method for transfection of primary leukemia cells and cell lines

BACKGROUND: Tumor cells such as leukemia and lymphoma cells are possible targets for gene therapy. However, previously leukemia and lymphoma cells have been demonstrated to be resistant to most of non-viral gene transfer methods. METHODS: The aim of this study was to analyze various methods for transfection of primary leukemia cells and leukemia cell lines and to improve the efficiency of gene delivery. Here, we evaluated a novel electroporation based technique called nucleofection. This novel technique uses a combination of special electrical parameters and specific solutions to deliver the DNA directly to the cell nucleus under mild conditions. RESULTS: Using this technique for gene transfer up to 75% of primary cells derived from three acute myeloid leukemia (AML) patients and K562 cells were transfected with the green flourescent protein (GFP) reporter gene with low cytotoxicity. In addition, 49(+/- 9.7%) of HL60 leukemia cells showed expression of GFP. CONCLUSION: The non-viral transfection method described here may have an impact on the use of primary leukemia cells and leukemia cell lines in cancer gene therapy.     

Arbuscular mycorrhizal fungi influence visitation rates of pollinating insects

Abstract.  1. Arbuscular mycorrhizal (AM) fungi can increase a number of plant traits to which pollinating insects are known to respond. These include total plant size, flower number, flower size, and amount of pollen produced.
2. It was hypothesised that these effects would lead to a different visitation rate of pollinating insects on mycorrhizal and non-mycorrhizal plants. To test this idea, three species of annual plants ( Centaurea cyanus , Tagetes erecta , and Tagetes patula ) were grown with and without AM fungi and the visits by pollinating insects were recorded over a 2-month period.
3. In all three species, mycorrhizal plants experienced a greater number of pollinator visits per flower per unit time. Diptera and Hymenoptera were the predominant insects and the latter order showed the strongest response.
4. Here, it is suggested that mycorrhizal fungi increase floral visitation rates by insects, but that the mechanism varies from one plant species to another. In C. cyanus , it appears to be due to flower number per plant, in T. patula it is individual inflorescence size, and in T. patula it is nectar standing crop per inflorescence.     

Density-dependent dispersal may explain the mid-season crash in some aphid populations

Aphid population dynamics during the season show a characteristic pattern with rapid increase in numbers at the beginning followed by a sudden drop in the middle of the season. This pattern is usually associated with predation and/or change in food quality during the summer. By developing a mechanistic model of aphid population dynamics we show that this pattern can arise from density-dependent dispersal behaviour of aphids. The dynamics produced by the model were similar to those observed in real populations of the alder aphid (Pterocallis alni). The two mechanisms required for these oscillations to arise were the perception of density through the number of contacts with other individuals and the inter-generational transfer of information (the maternal effect). Both mechanisms are examples of delayed density-dependence and, therefore, this study adds to the evidence that delayed density-dependence might cause complex population dynamics. To reproduce the seasonal dynamics of the alder aphid with the model, the maternal effect was essential, indicating that this could be an important factor in alder aphid dynamics. According to our model, external regulations (e.g., predation and/or change in food quality) were not required to explain the highly oscillatory population dynamics of aphids during a season.     

Uremia causes premature ageing of the T cell compartment in end-stage renal disease patients

ABSTRACT: BACKGROUND: End-stage renal disease (ESRD) patients treated with renal replacement therapy (RRT) have premature immunologically aged T cells which may underlie uremia-associated immune dysfunction. The aim of this study was to investigate whether uremia was able to induce premature ageing of the T cell compartment. For this purpose, we examined the degree of premature immunological T cell ageing by examining the T cell differentiation status, thymic output via T cell receptor excision circle (TREC) content and proliferative history via relative telomere length in ESRD patients not on RRT. RESULTS: Compared to healthy controls, these patients already had a lower TREC content and an increased T cell differentiation accompanied by shorter telomeres. RRT was able to enhance CD8+ T cell differentiation and to reduce CD8+ T cell telomere length in young dialysis patients. An increased differentiation status of memory CD4+ T cells was also noted in young dialysis patients. CONCLUSION: Based on these results we can conclude that uremia already causes premature immunological ageing of the T cell system and RRT further increases immunological ageing of the CD8+ T cell compartment in particular in young ESRD patients.