The PINE study: rationale and design of a randomised comparison of epidural injection of local anaesthetics and steroids versus care-as-usual to prevent postherpetic neuralgia in the elderly [ISRCTN32866390]

BACKGROUND: Postherpetic neuralgia (PHN) is by far the most common complication of herpes zoster (HZ) and one of the most intractable pain disorders. Since PHN is seen most often in the elderly, the number of patients with this disorder is expected to increase in our ageing society. PHN may last for months to years and has a high impact on the quality of life. The results of PHN treatment are rather disappointing. Epidural injection of local anaesthetics and steroids in the acute phase of HZ is a promising therapy for the prevention of PHN. Since randomised trials on the effectiveness of this intervention are lacking, the PINE (Prevention by epidural Injection of postherpetic Neuralgia in the Elderly) study was set up. The PINE study compares the effectiveness and cost-effectiveness of a single epidural injection of local anaesthetics and steroids during the acute phase of HZ with that of care-as-usual (i.e. antivirals and analgesics) in preventing PHN in elderly patients. METHODS / DESIGN: The PINE study is an open, multicenter clinical trial in which 550 elderly (age >/= 50 yr.) patients who consult their general practitioner in the acute phase of HZ (rash < 7 days) are randomised to one of the treatment groups. The primary clinical endpoint is the presence of HZ-related pain one month after the onset of the rash. Secondary endpoints include duration and severity of pain, re-interventions aiming to treat the existing pain, side effects, quality of life, and cost-effectiveness. CONCLUSION: The PINE study is aimed to quantify the (cost-) effectiveness of a single epidural injection during the acute phase of HZ on the prevention of PHN.     

Membrane lipids and vesicular traffic

Lipids were long considered to be passive passengers of carrier vesicles with the single role of sealing the transport container. We now know that specific phospholipids are required for efficient fusion, while others facilitate budding and fission. Moreover, the various polyphosphoinositides assist in the recruitment from the cytosol of proteins of the transport machinery. Finally, the segregation of membrane lipids into different fluid phases appears to serve as a 'lipid raft' mechanism for protein sorting at various stages of the secretory and endocytic pathways. The current challenge is to understand how proteins control the metabolism and subcellular localization, and thereby the activity, of the various lipids.     

Monophyly of beta-tubulin and H+-ATPase gene variants in Glomus intraradices: consequences for molecular evolutionary studies of AM fungal genes

Arbuscular mycorrhizal fungi (AMF) are an ecologically important group of fungi. Previous studies showed the presence of divergent copies of beta-tubulin and V-type vacuolar H+-ATPase genes in AMF genomes and suggested horizontal gene transfer from host plants or mycoparasites to AMF. We sequenced these genes from DNA isolated from an in vitro cultured isolate of Glomus intraradices that was free of any obvious contaminants. We found two highly variable beta-tubulin sequences and variable H+-ATPase sequences. Despite this high variation, comparison of the sequences with those in gene banks supported a glomeromycotan origin of G. intraradices beta-tubulin and H+-ATPase sequences. Thus, our results are in sharp contrast with the previously reported polyphyletic origin of those genes. We present evidence that some highly divergent sequences of beta-tubulin and H+-ATPase deposited in the databases are likely to be contaminants. We therefore reject the prediction of horizontal transfer to AMF genomes. High differences in GC content between glomeromycotan sequences and sequences grouping in other lineages are shown and we suggest they can be used as an indicator to detect such contaminants. H+-ATPase phylogeny gave unexpected results and failed to resolve fungi as a natural group. beta-Tubulin phylogeny supported Glomeromeromycota as sister group of the Chytridiomycota. Contrasts between our results and trees previously generated using rDNA sequences are discussed.     

How Predatory Mites Learn to Cope with Variability in Volatile Plant Signals in the Environment of their Herbivorous Prey

When the chemical cues co-occurring with prey vary in time and space, foraging predators profit from an ability to repeatedly associate chemical cues with the presence of their prey. We demonstrate the ability of a predatory arthropod (the plant-inhabiting mite, Phytoseiulus persimilis) to learn the association of a positive stimulus (herbivorous prey, Tetranychus urticae) or a negative stimulus (hunger) with a chemical cue (herbivore-induced plant volatiles or green leaf volatiles). It has been suggested that the rate at which the integration of information becomes manifest as a change in behaviour, differs between categories of natural enemies (parasitoids versus insect predators; specialist versus generalist predators). We argue that these differences do not necessarily reflect differential learning ability, but rather relate to the ecologically relevant time scale at which the biotic environment changes.     

Quantification of T-cell-mediated apoptosis in heterogeneous leukemia populations using four-color multiparameter flow cytometry.

BACKGROUND: The unique capacity of dendritic cells to present antigens to naive T cells is being increasingly utilized in cancer therapy. The efficacy of cell-based immunotherapy can be analyzed by determination of cytotoxic activity of T cells toward tumor cells in vitro. This study supplies a flow cytometric method to analyze T-cell-mediated cytotoxic activity toward heterogeneous leukemic cell populations at a single-cell level. METHODS: The fluorescent probe SYTO16 and the dead-cell dye 7-aminoactinomycine-D (7-AAD) were used to identify early and late stages of apoptosis in combination with leukemia cell-identifying markers. Determination of viable, apoptotic, and necrotic cells was performed by inclusion of fluorescent beads. RESULTS: In nine acute myeloid leukemia samples and three leukemic cell lines the use of SYTO16 next to the dead-cell marker 7-AAD significantly increased (P = 0.001) the sensitivity of the cytotoxicity assay as compared with single use of 7-AAD. Analysis of several effector-to-target ratios revealed the ability to determine dose-response effects. Enumeration of absolute numbers resulted in coefficients of variation of 4.1% and 8.4% for cell lines and leukemic samples, respectively. CONCLUSION: The presented flow cytometric cytotoxicity assay enables the study of T-cell-mediated apoptosis in a heterogenous leukemia population.     

Co‐evolution with recombination affects the stability of mobile genetic element insertions within gene families of Salmonella

Bacteria can have multiple copies of a gene at separate locations on the same chromosome. Some of these gene families, including tuf (translation elongation factor EF‐Tu) and rrl (ribosomal RNA), encode functions critically important for bacterial fitness. Genes within these families are known to evolve in concert using homologous recombination to transfer genetic information from one gene to another. This mechanism can counteract the detrimental effects of nucleotide sequence divergence over time. Whether such mechanisms can also protect against the potentially lethal effects of mobile genetic element insertion is not well understood. To address this we constructed two different length insertion cassettes to mimic mobile genetic elements and inserted these into various positions of the tuf and rrl genes. We measured rates of recombinational repair that removed the inserted cassette and studied the underlying mechanism. Our results indicate that homologous recombination can protect the tuf and rrl genes from inactivation by mobile genetic elements, but for insertions within shorter gene sequences the efficiency of repair is very low. Intriguingly, we found that physical distance separating genes on the chromosome directly affects the rate of recombinational repair suggesting that relative location will influence the ability of homologous recombination to maintain homogeneity.     

Euclidean distance can identify the mannitol level that produces the most remarkable integral effect on sugarcane micropropagation in temporary immersion bioreactors

Plant scientists usually record several indicators in their abiotic factor experiments. The common statistical management involves univariate analyses. Such analyses generally create a split picture of the effects of experimental treatments since each indicator is addressed independently. The Euclidean distance combined with the information of the control treatment could have potential as an integrating indicator. The Euclidean distance has demonstrated its usefulness in many scientific fields but, as far as we know, it has not yet been employed for plant experimental analyses. To exemplify the use of the Euclidean distance in this field, we performed an experiment focused on the effects of mannitol on sugarcane micropropagation in temporary immersion bioreactors. Five mannitol concentrations were compared: 0, 50, 100, 150 and 200 mM. As dependent variables we recorded shoot multiplication rate, fresh weight, and levels of aldehydes, chlorophylls, carotenoids and phenolics. The statistical protocol which we then carried out integrated all dependent variables to easily identify the mannitol concentration that produced the most remarkable integral effect. Results provided by the Euclidean distance demonstrate a gradually increasing distance from the control in function of increasing mannitol concentrations. 200 mM mannitol caused the most significant alteration of sugarcane biochemistry and physiology under the experimental conditions described here. This treatment showed the longest statistically significant Euclidean distance to the control treatment (2.38). In contrast, 50 and 100 mM mannitol showed the lowest Euclidean distances (0.61 and 0.84, respectively) and thus poor integrated effects of mannitol. The analysis shown here indicates that the use of the Euclidean distance can contribute to establishing a more integrated evaluation of the contrasting mannitol treatments.