29 research outputs found

    Enhancing resistance against African weevils through development of transgenic sweetpotato cultivars (Ipomoea batatas (L.) Lam.) expressing cry7Aa1, cry3Ca1 and ET33-34 genes.

    Get PDF
    Sweetpotato (Ipomoea batatas) is one of the most important food crops in tropical and subtropical countries. In Sub-Saharan Africa, sweetpotato is mainly produced for consumption and as a source of income by resource-poor farmers. However, their production is limited by severe damage caused by pests and diseases. The African weevils Cylas puncticollis and C. brunneus are the main biological constraints that may cause losses between 50 and 100%. Biotechnological approaches to control weevils include the introduction of genes encoding Cry proteins found to be active against these pests. To that end, several protocols for sweetpotato regeneration and transformation by organogenesis or somatic embryogenesis have been developed but their efficiency remains largely genotype-dependent and time-consuming. In this study, 31 African sweetpotato cultivars from CIP genebank were screened for regeneration and transformation efficiencies by organogenesis and somatic embryogenesis. Additionally, “Jewel” and “Jonathan” cultivars were used as organogenic and embryogenic controls, respectively. Regeneration by organogenesis was conducted using a two-step protocol including 2,4-D then thidiazuron, zeatin or kinetin while regeneration by embryogenesis was performed using a three-step protocol, each one using a different hormone (2,4,5-T, ABA and AG3). Higher than 40% regeneration efficiencies were obtained for 8 cultivars (Jewel, Imby, Kawogo, Luapula, Mafutha, CIP440163, Zambezi and Ukerewe) with an organogenesis protocol and 8 cultivars (Jonathan, Imby, K51/3251, Bwanjule, CIP440163, SPK004, New Kawogo and KSP 11) with an embryogenesis protocol. Genetic transformation of sweetpotato with Jewel by organogenesis and Imby, CIP440163 and Jonathan by somatic embryogenesis has been achieved using chimerical genes coding for three of the most active proteins (Cry7Aa1, ET33-34, and Cry3Ca1) against African weevils. Transgenic events have been confirmed by kanamycin resistant calli test, PCR and Southern blot. Transcriptional activity and Cry protein accumulation are being tested in leaves and storage roots by Real time PCR and DAS-ELISA respectively

    Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

    Get PDF
    Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

    Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

    Get PDF
    Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

    The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

    Get PDF
    AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

    The European Solar Telescope

    Get PDF
    The European Solar Telescope (EST) is a project aimed at studying the magnetic connectivity of the solar atmosphere, from the deep photosphere to the upper chromosphere. Its design combines the knowledge and expertise gathered by the European solar physics community during the construction and operation of state-of-the-art solar telescopes operating in visible and near-infrared wavelengths: the Swedish 1m Solar Telescope, the German Vacuum Tower Telescope and GREGOR, the French TĂ©lescope HĂ©liographique pour l’Étude du MagnĂ©tisme et des InstabilitĂ©s Solaires, and the Dutch Open Telescope. With its 4.2 m primary mirror and an open configuration, EST will become the most powerful European ground-based facility to study the Sun in the coming decades in the visible and near-infrared bands. EST uses the most innovative technological advances: the first adaptive secondary mirror ever used in a solar telescope, a complex multi-conjugate adaptive optics with deformable mirrors that form part of the optical design in a natural way, a polarimetrically compensated telescope design that eliminates the complex temporal variation and wavelength dependence of the telescope Mueller matrix, and an instrument suite containing several (etalon-based) tunable imaging spectropolarimeters and several integral field unit spectropolarimeters. This publication summarises some fundamental science questions that can be addressed with the telescope, together with a complete description of its major subsystems

    Voedsel, nieuwe voeding en allergeniciteit

    Get PDF
    Certain foods lead may to allergic responses in certain individuals. Main allergenic foods are Crustacea (shrimp, lobster, crab), egg, fish, milk, peanuts, soybeans, tree nuts, and wheat, and allergens are always proteins. A wide array of symptoms can result from food allergy (gastrointestinal, skin, respiratory). Severe and life threatening situations can occur. The prevalence is about 2% of the population; 5-8% of children. Based on the possibility to introduce new antigenic determinants when introducting new genes into crops, there is reason for concern that genetically engineered food may provide a health risk. Hazard identification concerning the allergenicity of newly engineered foods comprises evaluation of the source of the newly introduced gene, sequence similarities with known allergens, sensitivity to digestion, solid phase immunoassay with positive sera, skin prick testing and double-blind placebo-controlled food challenge in food allergic individuals. Genetically engineered foods that contain genes from non allergenic sources, but that lead to new proteins that are relatively insensitive to gastric simulated fluid degradation pose the biggest problem for evaluation of potential allergenicity. Therefore, animal models are being developed in which, after oral or parenteral exposure to proteins, analysis of antibody subclasses is performed to discriminate allergenicity from immunogenicity. The developing immune system is especially sensitive to immunomodulatory influences. The time at which food allergens are first encounterd may have an impact on the development of food allergy. Also factors that are in the food but are not allergenic themselves may influence the development of oral tolerance to food allergens, i.e. those moieties that influnece immune responses (immunotoxicants) or may influence entry of proteins into the mucosa.Voedselallergie kan gepaard gaan met een groot aantal symptomen (in het maag-darmkanaal, de huid, en de ademhalingsorganen) en kan leiden tot levensbedreigende situaties. De prevalentie van voedselallergie is ongeveer 2% van de bevolking; in kinderen 5-8%. Schaaldieren (garnalen, kreeft, krab), eieren, vis, melk, pinda, soya, noten, en tarwe zijn belangrijke allergene bronnen in onze voeding; het gaat daarbij altijd om eiwitten. Omdat de vervaardiging van genetisch gemodificeerde gewassen gepaard kan gaan met de introductie van nieuwe allergenen, bestaat bezorgdheid dat dergelijke nieuwe voedingsgewassen een nadelig effect op gezondheid kunnen hebben. Het identificeren van potentiele allergeniciteit van genetisch gemodificeerde voeding houdt in: evaluatie van de bron van het gen in het nieuwe voedsel, homologieen van de geintroduceerde genproducten met bestaande allergenen, stabiliteit in aanwezigheid van maagsappen, solid phase immunoassay met positieve humane sera, huidpriktesten, en dubbelblinde placebo-gecontroleerde voedselprovocatietesten in patienten met bewezen voedselallergie. Gemodificeerde voeding, waarin genen zijn geintroduceerd die afkomstig zijn uit niet allergene bronnen en die coderen voor eiwitten die relatief resistent zijn voor degradatie door maagsappen, vormen een groot probleem voor de beoordeling van het betreffende product. Om die reden worden diermodellen ontwikkeld, waarbij na orale of parenterale blootstelling aan de eiwitten antilichaamresponsen worden gemeten om immunogeniciteit en allergeniciteit te onderscheiden. Het zich ontwikkelende immuunsysteem is met name gevoelig voor effecten van immunologisch actieve factoren. Het tijdstip waarop een eerste contact met voedselallergenen plaats vindt kan een grote impact hebben op het al of niet ontstaan van voedselallergie. Factoren in de voeding die niet zelf allergeen zijn kunnen een invloed hebben op de het ontwikkelen van orale toletantie voor voedselallergenen, bijvoorbeeld omdat die bestanddelen immunologisch actief zijn of de toegang van allergenen tot de mucosa bevorderen
    corecore