41 research outputs found

    Time-resolved dual transcriptomics reveal early induced Nicotiana benthamiana root genes and conserved infection-promoting Phytophthora palmivora effectors

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    BACKGROUND: Plant-pathogenic oomycetes are responsible for economically important losses in crops worldwide. Phytophthora palmivora, a tropical relative of the potato late blight pathogen, causes rotting diseases in many tropical crops including papaya, cocoa, oil palm, black pepper, rubber, coconut, durian, mango, cassava and citrus. Transcriptomics have helped to identify repertoires of host-translocated microbial effector proteins which counteract defenses and reprogram the host in support of infection. As such, these studies have helped in understanding how pathogens cause diseases. Despite the importance of P. palmivora diseases, genetic resources to allow for disease resistance breeding and identification of microbial effectors are scarce. RESULTS: We employed the model plant Nicotiana benthamiana to study the P. palmivora root infections at the cellular and molecular levels. Time-resolved dual transcriptomics revealed different pathogen and host transcriptome dynamics. De novo assembly of P. palmivora transcriptome and semi-automated prediction and annotation of the secretome enabled robust identification of conserved infection-promoting effectors. We show that one of them, REX3, suppresses plant secretion processes. In a survey for early transcriptionally activated plant genes we identified a N. benthamiana gene specifically induced at infected root tips that encodes a peptide with danger-associated molecular features. CONCLUSIONS: These results constitute a major advance in our understanding of P. palmivora diseases and establish extensive resources for P. palmivora pathogenomics, effector-aided resistance breeding and the generation of induced resistance to Phytophthora root infections. Furthermore, our approach to find infection-relevant secreted genes is transferable to other pathogen-host interactions and not restricted to plants.This work was supported by the Gatsby Charitable Foundation (RG62472), by the Royal Society (RG69135) and by the European Research Council (ERC-2014-STG, H2020, 637537)

    A peer mentorship to enhance active lifestyle and community integration in people with spinal cord injury : I wheel

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    Wheelchair maintenance is an important factor in wheelchair mobility. Currently, there is no standardized training resource available to teach wheelchair users about the maintenance or set-up of their manual wheelchairs. Purpose: The purpose of this feasibility research was to assess the feasibility of conducting an experimental study to evaluate the wheelchair maintenance training program. Method: The research program had two main phases. Phase 1 included the development of learning materials, evaluation forms and tests. We performed reliability tests on the 3-cone test and wheelchair maintenance knowledge test and report them in chapter two and three. Phase 2 entailed a feasibility study. In this study, we conducted a wheelchair maintenance workshop to train the mentors (n=5) and then assigned each mentor three mentees (n =15). Each mentor conducted a one-on-one peer-session with each mentee and each mentee completed assigned tests and questionnaires during three assessment visits (baseline, and 2 and 4 weeks after their peer session). Feasibility outcomes were evaluated, and all mentees completed an exit survey at the end of the wheelchair maintenance training program. Results: The 3-cone test and the wheelchair maintenance knowledge test are reliable (ICC >0.9) to use in clinical research. In feasibility study for wheelchair maintenance training, the process outcome (recruitment rate: mentor 71%, mentee 25%), resource outcome (retention rate (>90%), adherence (>90%), fidelity (>80%), completion rate (>90%) and training satisfaction (>90%) and preliminary evaluation outcomes were achieved. Scheduling (management outcome) was challenging and we were not able to meet the goal projected for this outcome, however we were able to complete all the sessions. Conclusion: The 3-cone test and the wheelchair maintenance knowledge test appear to be useful and reliable to be used in the clinical setting. Summary and descriptive results from the feasibility study were sufficient to justify conducting a subsequent randomized controlled trial. We hope to replicate the findings of wheelchair maintenance training by demonstrating the change in mechanical efficacy of wheelchair and the increased knowledge about wheelchair maintenance in the future. This evidence could then be used to support changes in teaching and knowledge improvement in wheelchair maintenance.Medicine, Faculty ofExperimental Medicine, Division ofMedicine, Department ofGraduat

    Vascular Response to Graded Angiotensin II Infusion in Offspring Subjected to High-Salt Drinking Water during Pregnancy: The Effect of Blood Pressure, Heart Rate, Urine Output, Endothelial Permeability, and Gender

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    Introduction. Rennin-angiotensin system and salt diet play important roles in blood pressure control. We hypothesized that the high-salt intake during pregnancy influences the degree of angiotensin-dependent control of the blood pressure in adult offspring. Methods. Female Wistar rats in two groups (A and B) were subjected to drink tap and salt water, respectively, during pregnancy. The offspring were divided into four groups as male and female offspring from group A (groups 1 and 2) and from group B (groups 3 and 4). In anesthetized matured offspring mean arterial pressure (MAP), heart rate and urine output were measured in response to angiotensin II (AngII) (0-1000 ng/kg/min, iv) infusion. Results. An increase in MAP was detected in mothers with salt drinking water (P<0.05). The body weight increased and kidney weight decreased significantly in male offspring from group 3 in comparison to group 1 (P<0.05). MAP and urine volume in response to AngII infusion increased in group 3 (P<0.05). These findings were not observed in female rats. Conclusion. Salt overloading during pregnancy had long-term effects on kidney weight and increased sex-dependent response to AngII infusion in offspring (adult) that may reveal the important role of diet during pregnancy in AngII receptors

    Preventive role of estradiol on kidney injury induced by renal Ischemia-Reperfusion in male and female rats

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    Background: Renal ischemia-reperfusion (RIR) is the main cause of renal failure. The incidence of RIR injury seems to be gender-related due to female sex hormone; estrogen. This study was designed to investigate the protective role of estrogen against RIR injury in male and ovariectomized female rats. Methods: Thirty-nine Wistar rats were used in this study as male and ovariectomized female rats in the sham-operated, RIR, and estradiol-treated plus RIR groups. The RIR was induced by clamping the renal vessels for 45 min and then 24 h of reperfusion. All animals finally were sacrificed for the measurements. Results: The serum levels of creatinine and blood urea nitrogen and kidney tissue damage score significantly increased in both male and female RIR rats (P < 0.05). Estradiol however significantly attenuated theses parameters (P < 0.05) toward normal levels in female (P < 0.05), but not in male rats. Kidney weight increased in both genders and estradiol intensified it in the male rats (P < 0.05). Uterus weight was increased by estradiol in female rats (P < 0.05) and testis weight did not alter in male rats. Conclusions: Estradiol demonstrated a protective role against RIR injury in female rats; however, estradiol as an antioxidant could not protect the male kidney from RIR injury

    Antimicrobial Activities of the Secondary Metabolite Extracted from a Nocardia Strain

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    Background & Objective: The emergence of antibiotic-resistant bacteria and limited treatment options for these infections is a challenging problem in the world. There is increasing interest in isolating bioactive molecules from actinobacteria and elucidating their antimicrobial mechanisms at the moment. The current study aimed to investigate the antimicrobial activities of a Nocardia strain (N4) that was previously isolated from the soil samples in Tehran, Iran.  Materials & Methods: The cultural, morphological, and physiological characteristics of the strain were determined and the identity of the strain was confirmed using 16SrRNA gene sequencing. The strain was screened for antimicrobial metabolite production. The in vitro anti-microbial activity of the extracted metabolite was assessed by agar well diffusion and minimum inhibitory concentrations methods. Finally, the structure of the extracted metabolite was confirmed by HPLC and mass spectrometry methods. Results: The isolate shared 99% sequence similarity with Nocardia soli. The strain showed broad-spectrum antimicrobial activities against some pathogenic bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 700603, Salmonella Typhimurium ATCC 14028 and Shigella sonnei RI366) and fungi (Aspergillus niger ATCC 1015 and Aspergillus fumigatus ATCC 1022) in the agar well diffusion method. The ethyl acetate extract of the strain exhibited the highest antimicrobial activity against E. coli (MIC= 4.67±3.055 μg/mL) and K. pneumoniae (MIC=3.33±1.155 μg/mL). The metabolite showed high similarity with C21H28N7O14. Conclusions: The current study confirmed the presence of a bioactive metabolite in strain N4, suggesting that this may be a promising candidate for discovering bioactive components with broad antibacterial activities against a variety of pathogens Keywords

    Effect of nicorandil on QT dispersion in patients with stable angina pectoris undergoing elective angioplasty: A triple-blind, randomized, placebo-controlled study

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    Background: Nicorandil leads to the relaxation of fine vascular smooth muscle, and thus causes vasodilatation of major epicardial. Also, it has anti-arrhythmic and cardio-protective effects by improving reperfusion, and ultimately leads to a reduction in microvascular damage caused by percutaneous coronary intervention (PCI). Objective: The aim of this study was to determine the effect of nicorandil on QT interval dispersion (QTd) in patients with stable angina pectoris during elective angioplasty. Methods: This triple-blind and randomized clinical trial was performed on patients with stable angina pectoris, candidates for elective angiography referred to Imam Reza and Ghaem hospitals in Mashhad, Iran, between January and October 2016. The patients were randomly assigned to one of two groups receiving nicorandil (60 mg as 20 mg before and 40 mg after PCI) and placebo. All the patients underwent electrocardiography 12 hours before and 12 hours after PCI. The values of maximal corrected QT interval (QTc max) and QTd in these intervals, and the levels of changes in the QTd (QTd difference before angiography and after PCI) were compared between the two groups. Data were analyzed statistically using SPSS version 18 software via Chi-square and Independent-samples t-test. Results: This study was performed on 90 patients (55 males and 35 females) with a mean age of 58.6±10.8 years, on two groups of 45 people. The two groups were matched for age, body mass index, cardiovascular risk factors and baseline testing. The QTd before angiography had no statistically significant difference between the patients of both groups (control: 77.7±17.1 vs. nicorandil: 80.7±14.2 ms; p=0.371). The QTd after PCI in the nicorandil group was lower than the control group (48.1±14.2 vs. 59.2±15.6 ms; p=0.000). The decrease rate in QTd had a statistically significant difference between the two groups (control: 18.9±11.0 vs. nicorandil: 33.5±9.5 ms; p=0.000). Conclusions: The results of this study showed that oral administration of nicorandil around the PCI could further reduce QTd following PCI, compared to the control group. Trial registration: The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the Irct ID: IRCT2016120631159N1 Funding: The authors received no financial support for the research, authorship, and/or publication of this article

    Exposure to drought: adaptive strategies amongst rural natural resource dependent societies in Africa

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    Adaptation to climate change and variability has recently emerged as an important research focus, as projected climate change scenarios for this century suggest significant disturbance to the livelihoods of natural resource dependent communities in the developing world, and especially in Africa. Within the international policy arena, there is growing awareness that adaptation to the impacts of climate change is crucial. Despite considerable work on livelihood strategies to climate vanability and change in 25 years, there has yet been little examination of the actual processes through which adaptations occur, especially what leads to successful pathways of adaptation.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Gentamicin Induced Nephrotoxicity: The Role of Sex Hormones in Gonadectomized Male and Female Rats

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    Background. Gentamicin (GM) induced nephrotoxicity may be sex hormones related. The effects of sex hormones on GM induced nephrotoxicity in gonadectomized rats were investigated. Methods. Ovariectomized rats received 0.25, 0.5, or 1 mg/kg/week of estradiol (ES) alone or accompanied with 10 mg/kg/week of progesterone (Pro) for two weeks followed by GM (100 mg/kg/day) for 9 days. Castrated rats were also treated with 10, 50, or 100 mg/kg/week of testosterone (TS) for two weeks and then received GM. In addition, a single castrated group received 0.25 mg/kg/week of ES plus GM. Results. GM increased the serum levels of blood urea nitrogen (BUN) and creatinine (Cr) and kidney tissue damage score (KTDS) (P<0.05). TS had no effect on the serum levels of BUN and Cr and KTDS, while low dose of ES intensified these parameters in male (P<0.05). ES (0.5 mg/kg) without Pro ameliorated KTDS in female (P<0.05) while ES (1 mg/kg) with or without Pro exacerbated the BUN values and Cr values, KTDS, and body weight loss (P<0.05). Conclusion. ES (0.5 mg/kg) without Pro ameliorated kidney damage induced by GM in female while neither TS nor ES had beneficial effect on nephrotoxicity induced by GM in male, although ES aggravated it
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