708 research outputs found

    Detection of transgenic and endogenous plant DNA in blood and organs of Nile tilapia, Oreochromis niloticus fed a diet formulated with genetically modified soybean meal

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    Anxiety regarding the fate of ingested transgenic DNA in farmed fish fed genetically modified (GM) soybean meal (SBM) has been raised with regard to human consumption. The objective of this study was to detect possibility of gene transfer of transgenic and endogenous DNA fragments in Nile tilapia (Oreochromis niloticus) blood and organs after consumption of a GM SBM diet. Nile tilapias with an average weight of 75.0 g were fed diets containing 48% GM or non-GM SBM for 21 days. During this period, a GM SBM diet was fed to fish for 12 days, and then switched to feed with non-GM SBM for 9 days for determining the residual span of the transferred cauliflower mosaic virus (CaMV) 35S promoter fragment. Blood, spleen, liver, intestine, kidney, and muscle tissues were taken (n = 10) every three days during the feeding period. Total DNA was extracted from the samples and analyzed by polymerase chain reaction (PCR) for determining the presence of a 108-bp fragment of the CaMV 35S promoter and a 144-bp fragment of the soybean chloroplast-specific DNA. Low-copy chloroplast-specific DNA fragment was detected in all organ and tissue samples and the majority of intestinal samples of fish fed GM SBM diet. Similarly, a low number and faint signals of the CaMV 35S promoter fragments were detected in all organ samples except muscle of fish fed the GM SBM diet, while none were detected 3 days after changing to a non-GM SBM diet. A very low frequency of transmittance to muscle and organs of fish was confirmed. It is recognized that the low copy number of transgenic DNA in the GM SBM diet is a challenge to their detection in tissues. These results suggested that transgenic DNA would be processed in the gastrointestinal tract in a similar manner with conventional plant DNA

    Edwardsiellosis, common and novel manifestations of the disease: A review

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    P?ginas. 82-90Recurso Electr?nicoEdwardsiella tarda es una bacteria Gram-negativa encontrada com?nmente en ambientes y animales acu?ticos donde causa edwardsiellosis o septicemia por Edwardsiella tarda. La bacteria tiene una distribuci?n mundial y un alto potencial de infectar a humanos, causando infecciones que van desde una enfermedad gastrointestinal autolimitante en reci?n nacidos y adultos ancianos hasta infecciones extraintestinales similares a aquellas observadas en peces. Las lesiones incluyen abscesos, piogranulomas y necrosis en tejidos, como el cerebro, el h?gado, la piel y los m?sculos. La distribuci?n sist?mica del microrganismo usualmente termina en septicemia. Varios de los cambios patol?gicos inducidos por E. tarda en humanos son consistentemente observados en peces enfermos, y estos animales constituyen un modelo apropiado para el estudio de la patog?nesis de edwardsiellosis. En esta revisi?n, se describen las manifestaciones cl?nicas, los cambios patol?gicos macrosc?picos y microsc?picos comunes y nuevos de la enfermedad en dos especies de peces de importancia comercial: el lenguado japon?s (Paralichthys olivaceus) y la tilapia h?brida (Oreochromis spp.), as? como la variedad de infecciones reportadas en humanos.Edwardsiella tarda is a Gram-negative bacterium commonly found in aquatic environments and in water-borne animals where it causes a disease named edwardsiellosis or Edwardsiella septicemia. The bacterium is distributed worldwide and has ahigh potential to infect humans, causing infections ranging from self-limited gastrointestinal disease particularly in newborns and aged, and a variety of extraintestinal infections similar to those observed in affected fish, including pyogranulomatous inflammation, abscesses and necrosis in different tissues such as the brain, liver, skin and muscles. Systemic dissemination of the micro-organism usually ends in septicemia. Many of the pathological changes induced by E. tarda in humans are consistently observed in diseased fish, and these animals seem to be an appropriate model to study the pathogenesis of edwardsiellosis. In this review we describe common and novel clinical, gross and histopathological manifestations of the entity in two commercial fish species, Japanese flounder (Paralichthys olivaceus) and tilapia hybrids (Oreochromis spp.), as well as the diversity of infections documented in humans

    Bld10p, a novel protein essential for basal body assembly in Chlamydomonas: localization to the cartwheel, the first ninefold symmetrical structure appearing during assembly

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    How centrioles and basal bodies assemble is a long-standing puzzle in cell biology. To address this problem, we analyzed a novel basal body-defective Chlamydomonas reinhardtii mutant isolated from a collection of flagella-less mutants. This mutant, bld10, displayed disorganized mitotic spindles and cytoplasmic microtubules, resulting in abnormal cell division and slow growth. Electron microscopic observation suggested that bld10 cells totally lack basal bodies. The product of the BLD10 gene (Bld10p) was found to be a novel coiled-coil protein of 170 kD. Immunoelectron microscopy localizes Bld10p to the cartwheel, a structure with ninefold rotational symmetry positioned near the proximal end of the basal bodies. Because the cartwheel forms the base from which the triplet microtubules elongate, we suggest that Bld10p plays an essential role in an early stage of basal body assembly. A viable mutant having such a severe basal body defect emphasizes the usefulness of Chlamydomonas in studying the mechanism of basal body/centriole assembly by using a variety of mutants

    An oral delivery system for controlling white spot syndrome virus infection in shrimp using transgenic microalgae

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    White spot disease (WSD) is a longstanding and serious viral disease of various shrimp species that has caused high mortality rates for many decades. Currently, there is no practical method to control this disease. Therefore, we have explored the development of a novel vaccine-based method to control this disease using transgenic algae. During infection by white spot syndrome virus (WSSV), the interaction between viral envelope proteins and cell surface protein receptors on target cells is the key step of viral entry and replication. Hence, transgenic lines of the green microalga Chlamydomonas reinhardtii harbouring a WSSV VP28 viral envelope protein were created as an oral delivery system for vaccinating shrimp. Two separate transplastomic lines containing wild-type and codon optimized gene sequences for VP28 were evaluated for recombinant protein levels. Only the codon optimized line gave rise to detectable VP28 in western blot analysis, which demonstrated that optimization for chloroplast codon bias improved the efficiency of expression and that the gene design produced a favourable RNA secondary structure with suitable free energy for translation. In addition, bile salt and acid tolerance tests demonstrated that this transgenic Chlamydomonas can tolerate mildly acidic (pH 5.0) conditions and 0.30% bile salts. These features indicated that algal cells are suitable for delivering viral antigens through a shrimp's digestive system. In WSSV infection experiments, the highest survival rate (87%) was recorded in shrimps fed with the codon optimized VP28 line mixed into their feed, indicating that this line could be employed in the control of WSSV spread in shrimp populations. This algal strategy offers a new, efficient, fast and less labour-intensive method for the control of other diseases in aquatic animals through oral delivery

    Fast Adaptation in Vestibular Hair Cells Requires Myosin-1c Activity

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    SummaryIn sensory hair cells of the inner ear, mechanical amplification of small stimuli requires fast adaptation, the rapid closing of mechanically activated transduction channels. In frog and mouse vestibular hair cells, we found that the rate of fast adaptation depends on both channel opening and stimulus size and that it is modeled well as a release of a mechanical element in series with the transduction apparatus. To determine whether myosin-1c molecules of the adaptation motor are responsible for the release, we introduced the Y61G mutation into the Myo1c locus and generated mice homozygous for this sensitized allele. Measuring transduction and adaptation in the presence of NMB-ADP, an allele-specific inhibitor, we found that the inhibitor not only blocked slow adaptation, as demonstrated previously in transgenic mice, but also inhibited fast adaptation. These results suggest that mechanical activity of myosin-1c is required for fast adaptation in vestibular hair cells

    Group cognitive behavioural therapy (GCBT) versus treatment as usual (TAU) in the treatment of irritable bowel syndrome (IBS): A study protocol for a randomized controlled trial

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    Background: Irritable bowel syndrome (IBS) is a common disease that affects the quality of life (QOL) and social functioning of sufferers. Visceral anxiety is currently considered a key factor in the onset and exacerbation of IBS, and cognitive-behavioural therapy (CBT) targeting visceral anxiety is thought to be effective. However, access to CBT is limited due to the lack of trained therapists, the substantial time required for therapy and the associated costs. Group CBT (GCBT) may solve some of these problems. We have therefore planned this trial to examine the efficacy of GCBT for IBS. Methods: The trial is a two-armed, parallel group, open label, stratified block randomized superiority trial. The study group will consist of 112 participants (aged 18–75 years) with IBS (Rome-III or IV criteria). Participants will be randomly allocated 1:1 to (i) the intervention group: ten-week GCBT plus treatment as usual (TAU) or (ii) the control group: waiting list (WL) plus TAU. The co-primary outcomes are the change in IBS severity or disease-specific quality of life from baseline to week 13 which is 1 month after the end of treatment. The efficacy of GCBT for IBS will be examined through mixed-effects repeated-measures analysis. Discussion: GCBT, if found effective, can address the issues of the shortage of therapists as well as the time required and the costs associated with individual CBT. Clinically, the findings will help make effective CBT programmes accessible to a large number of distressed IBS patients at lower costs. Theoretically, the results will clarify the relationship between IBS and psychological stress and will help elucidate the underlying mechanisms of IBS. Trial registration: UMIN, CTR-UMIN000031710. Registered on March 13, 2018

    Impact of the Method of G6PD Deficiency Assessment on Genetic Association Studies of Malaria Susceptibility

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    BACKGROUND:Clinical association studies have yielded varied results regarding the impact of glucose-6-phosphate dehydrogenase (G6PD) deficiency upon susceptibility to malaria. Analyses have been complicated by varied methods used to diagnose G6PD deficiency. METHODOLOGY/PRINCIPAL FINDINGS:We compared the association between uncomplicated malaria incidence and G6PD deficiency in a cohort of 601 Ugandan children using two different diagnostic methods, enzyme activity and G6PD genotype (G202A, the predominant East African allele). Although roughly the same percentage of males were identified as deficient using enzyme activity (12%) and genotype (14%), nearly 30% of males who were enzymatically deficient were wild-type at G202A. The number of deficient females was three-fold higher with assessment by genotype (21%) compared to enzyme activity (7%). Heterozygous females accounted for the majority (46/54) of children with a mutant genotype but normal enzyme activity. G6PD deficiency, as determined by G6PD enzyme activity, conferred a 52% (relative risk [RR] 0.48, 95% CI 0.31-0.75) reduced risk of uncomplicated malaria in females. In contrast, when G6PD deficiency was defined based on genotype, the protective association for females was no longer seen (RR = 0.99, 95% CI 0.70-1.39). Notably, restricting the analysis to those females who were both genotypically and enzymatically deficient, the association of deficiency and protection from uncomplicated malaria was again demonstrated in females, but not in males (RR = 0.57, 95% CI 0.37-0.88 for females). CONCLUSIONS/SIGNIFICANCE:This study underscores the impact that the method of identifying G6PD deficient individuals has upon association studies of G6PD deficiency and uncomplicated malaria. We found that G6PD-deficient females were significantly protected against uncomplicated malaria, but this protection was only seen when G6PD deficiency is described using enzyme activity. These observations may help to explain the discrepancy in some published association studies involving G6PD deficiency and uncomplicated malaria
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