Rapid detection of potyviruses from crude plant extracts

Potyviruses (genus Potyvirus; family Potyviridae) are widely distributed and represent one of the most economically important genera of plant viruses. Therefore, their accurate detection is a key factor in developing efficient control strategies. However, this can sometimes be problematic particularly in plant species containing high amounts of polysaccharides and polyphenols such as yam (Dioscorea spp.). Here, we report the development of a reliable, rapid and cost-effective detection method for the two most important potyviruses infecting yam based on reverse transcription-recombinase polymerase amplification (RT-RPA). The developed method, named ‘Direct RT-RPA’, detects each target virus directly from plant leaf extracts prepared with a simple and inexpensive extraction method avoiding laborious extraction of high-quality RNA. Direct RT-RPA enables the detection of virus-positive samples in under 30 min at a single low operation temperature (37 °C) without the need for any expensive instrumentation. The Direct RT-RPA tests constitute robust, accurate, sensitive and quick methods for detection of potyviruses from recalcitrant plant species. The minimal sample preparation requirements and the possibility of storing RPA reagents without cold chain storage, allow Direct RT-RPA to be adopted in minimally equipped laboratories and with potential use in plant clinic laboratories and seed certification facilities worldwide

The performance of a smart ball-and-socket actuator applied to upper-limb rehabilitation

Magnetorheological fluids are capable of providing continuously variable yield stresses in response to external magnetic fields. Greater potential application in rehabilitation may be realised if these fluids are utilised in controllable actuators offering multi-degree-of-freedom motions. This article presents the results of the comparative performance of a ball-and-socket actuator, employing magnetorheological fluids as the controllable medium, using theoretical and numerical approaches. The theoretical model combines the viscous friction and the controllable field-dependent characteristics of the magnetorheological fluid in which a Bingham plastic model is used to simulate the shear stress of the fluid under various input conditions. A special procedure to simulate the device performance using computational fluid dynamics techniques, which were performed using ANSYS CFX computer code, is detailed. Three commercial magnetorheological fluids (MRF241-ES, MRF132-AD and MRF122-2ED) were assessed and it was found that the simulated values of the device torque compared well with the theoretical values.</p

Rapid and specific detection of Yam mosaic virus by reverse-transcription recombinase polymerase amplification

Yam mosaic virus (YMV; genus Potyvirus) is considered to cause the most economically important viral disease of yams (Dioscorea spp.) in West Africa which is the dominant region for yam production globally. Yams are a vegetatively propagated crop and the use of virus-free planting material forms an essential component of disease control. Current serological and PCR-based diagnostic methods for YMV are time consuming involving a succession of target detection steps. In this study, a novel assay for specific YMV detection is described that is based on isothermal reverse transcription-recombinase polymerase amplification (RT-exoRPA). This test has been shown to be reproducible and able to detect as little as 14 pg/μl of purified RNA obtained from an YMV-infected plant, a sensitivity equivalent to that obtained with the reverse transcription-polymerase chain reaction (RT-PCR) in current general use. The RT-exoRPA assay has, however, several advantages over the RT-PCR; positive samples can be detected in less than 30 min, and amplification only requires a single incubation temperature (optimum 37 °C). These features make the RT-exoRPA assay a promising candidate for adapting into a field test format to be used by yam breeding programmes or certification laboratories

Reprogramming of hepatic fat accumulation and 'browning' of adipose tissue by the short-chain fatty acid acetate

Background/Objectives: Short-chain fatty acids, produced by microbiome fermentation of carbohydrates, have been linked to a reduction in appetite, body weight and adiposity. However, determining the contribution of central and peripheral mechanisms to these effects has not been possible. Subjects/Methods:C57BL/6 mice fed with either normal or high-fat diet were treated with nanoparticle-delivered acetate, and the effects on metabolism were investigated. Results:In the liver, acetate decreased lipid accumulation and improved hepatic function, as well as increasing mitochondrial efficiency. In white adipose tissue, it inhibited lipolysis and induced 'browning', increasing thermogenic capacity that led to a reduction in body adiposity. Conclusions:This study provides novel insights into the peripheral mechanism of action of acetate, independent of central action, including ‘browning’ and enhancement of hepatic mitochondrial function

Portal Vein Thrombosis after Restorative Proctocolectomy for Familial Adenomatous Polyposis and Sigmoid Cancer

Postoperative portal vein thrombosis (PVT) is rare, but has been described after various open as well as minimal access abdominal operations, especially splenectomy and colorectal surgical procedures. We report the case of a 39-year-old female who underwent restorative proctocolectomy and ileal pouch-anal anastomosis for familial adenomatous polyposis with sigmoid cancer. She presented 14 days later with vague upper abdominal pain, nausea, vomiting and high output stoma. Doppler ultrasonography confirmed PVT and therefore anticoagulant therapy was started. Her condition improved dramatically and she underwent closure of ileostomy after finishing adjuvant chemotherapy. She remained well at 3-year follow-up with good pouch function and no local or distant recurrence. A high index of suspicion is essential for early diagnosis and prompt treatment of postoperative PVT after restorative proctocolectomy. Early anticoagulation is essential to avoid subsequent complications

Withdrawal of Long-Term Nucleotide Analog Therapy in Chronic Hepatitis B:Outcomes From the Withdrawal Phase of the HBRN Immune Active Treatment Trial

INTRODUCTION:Withdrawal of nucleos(t)ide analog therapy is increasingly being evaluated in chronic hepatitis B infection as a strategy to induce hepatitis B surface antigen (HBsAg) loss. The Hepatitis B Research Network Immune-Active Trial evaluated treatment with tenofovir (TDF) for 4 years ± an initial 6 months of peginterferon-α (PegIFN) (NCT01369212) after which treatment was withdrawn.METHODS:Eligible participants (hepatitis B e antigen [HBeAg]-/anti-HBe+, hepatitis B virus [HBV] DNA &lt;103IU/mL, no cirrhosis) who discontinued TDF were followed for at least 1 year with optional follow-up thereafter. Retreatment was based on predefined criteria.RESULTS:Among 201 participants who received 4 years of treatment, 97 participants (45 TDF and 52 TDF + PegIFN arm, 79 Asian) discontinued TDF. HBsAg loss occurred in 5 participants, 2 within 25 weeks and 3 within 89-119 weeks postwithdrawal (cumulative rate 4.3% by 2 years). Alanine aminotransferase (ALT) flares (&gt;5× upper limit of normal) after TDF withdrawal occurred in 36 (37.1%) participants and occurred more frequently and earlier in those HBeAg- compared with HBeAg+ at treatment initiation. ALT flares were associated with older age and higher HBV DNA pretreatment and at the visit before the flare. ALT flares were not significantly associated with HBsAg decline or loss but were associated with immune active disease at 1 year (70.6% vs 11.9%, P &lt; 0.0001) and 2 years (66.7% vs 25.9%, P = 0.03) postwithdrawal. Treatment reinitiation was required in 13 (13.4%) participants, and 13 others remained in a sustained inactive carrier state by the end of the study follow-up. No criteria reliably predicted safe treatment withdrawal.DISCUSSION:Results from this trial do not support TDF withdrawal as a therapeutic strategy. HBsAg loss was infrequent within 2 years of stopping long-term TDF. If withdrawal is considered, HBV DNA should be carefully monitored with reinitiation of therapy if levels rise above 4 log10IU/mL to reduce the risk of ALT flares, as they were not associated with subsequent HBsAg decline or loss.</p

Randomized Trial of Tenofovir With or Without Peginterferon Alfa Followed by Protocolized Treatment Withdrawal in Adults With Chronic Hepatitis B

INTRODUCTION:Hepatitis B surface antigen (HBsAg) loss is associated with improved long-term outcomes of patients with chronic hepatitis B but is infrequently achieved with current monotherapies. We assessed whether combination strategies that included treatment withdrawal enhanced HBsAg loss.METHODS:A randomized (1:1) trial of tenofovir disoproxil fumarate (TDF) for 192 weeks with or without peginterferon (PegIFN) alfa-2a for the first 24 weeks, followed by withdrawal of TDF at week 192 with 48 weeks of off-treatment follow-up to week 240. The primary end point was HBsAg loss at week 240.RESULTS:Of 201 participants (52% HBeAg positive, 12%/6% genotype A/A2, 7% cirrhosis) randomized to TDF + PegIFN (n = 102) or TDF alone (n = 99), 6 participants had lost HBsAg at the end of the treatment phase (week 192), 5 (5.3%) in the combination group, and 1 (1.0%) in the TDF alone group (P = 0.09). By week 240, 9 participants had cleared HBsAg, 5.3% in combination, and 4.1% in monotherapy arms (P = 0.73). HBsAg decline and loss occurred earlier with TDF + PegIFN than TDF, with a ≥1-logIU/mL qHBsAg decline by week 24 in 28% in TDF + PegIFN compared with 6% in TDF (P = 0.04). HBsAg loss occurred in 7 of 12 (58%) with hepatitis B virus subgenotype A2 (all HBeAg positive) compared with only 2 of 189 (1%) with other hepatitis B virus genotypes and in 8 of 93 (8.6%) HBeAg positive vs 1 of 87 (1.1%) HBeAg negative.DISCUSSION:PegIFN combined TDF followed by protocolized TDF withdrawal led to earlier but not higher percentages of HBsAg clearance. Pretreatment HBeAg positivity and subgenotype A2 were strongly associated with HBsAg clearance.</p

Unlocking community capability through promotion of self-help for health: experience from Chakaria, Bangladesh

Background People’s participation in health, enshrined in the 1978 Alma Ata declaration, seeks to tap into community capability for better health and empowerment. One mechanism to promote participation in health is through participatory action research (PAR) methods. Beginning in 1994, the Bangladeshi research organization ICDDR,B implemented a project “self-help for health,” to work with existing rural self-help organizations (SHOs). SHOs are organizations formed by villagers for their well-being through their own initiatives without external material help. This paper describes the project’s implementation, impact, and reflective learnings. Methods Following a self-help conceptual framework and PAR, the project focused on building the capacity of SHOs and their members through training on organizational issues, imparting health literacy, and supporting participatory planning and monitoring. Quarterly activity reports and process documentation were the main sources of qualitative data used for this paper, enabling documentation of changes in organizational issues, as well as the number and nature of initiatives taken by the SHOs in the intervention area. Health and demographic surveillance system (HDSS) data from intervention and comparison areas since 1999 allowed assessment of changes in health indicators over time. Results Villagers and members of the SHOs actively participated in the self-help activities. SHO functionality increased in the intervention area, in terms of improved organizational processes and planned health activities. These included most notably in convening more regular meetings, identifying community needs, developing and implementing action plans, and monitoring progress and impact. Between 1999 and 2015, while decreases in infant mortality and increases in utilization of at least one antenatal care visit occurred similarly in intervention and comparison areas, increases in immunization, skilled birth attendance, facility deliveries and sanitary latrines were substantially more in intervention than comparison areas. Conclusion Building community capability by working with pre-existing SHOs, encouraging them to place health on their agendas, strengthening their functioning and implementation of health activities led to sustained improvements in utilization of services for over 20 years. Key elements underpinning success include efforts to build and maintain trust, ensuring social inclusion in project activities, and balancing demands for material resources with flexibility to be responsive to community needs

Are 'Village Doctors' in Bangladesh a curse or a blessing?

<p>Abstract</p> <p>Background</p> <p>Bangladesh is one of the health workforce crisis countries in the world. In the face of an acute shortage of trained professionals, ensuring healthcare for a population of 150 million remains a major challenge for the nation. To understand the issues related to shortage of health workforce and healthcare provision, this paper investigates the role of various healthcare providers in provision of health services in Chakaria, a remote rural area in Bangladesh.</p> <p>Methods</p> <p>Data were collected through a survey carried out during February 2007 among 1,000 randomly selected households from 8 unions of Chakaria <it>Upazila</it>. Information on health-seeking behaviour was collected from 1 randomly chosen member of a household from those who fell sick during 14 days preceding the survey.</p> <p>Results</p> <p>Around 44% of the villagers suffered from an illness during 14 days preceding the survey and of them 47% sought treatment for their ailment. 65% patients consulted Village Doctors and for 67% patients Village Doctors were the first line of care. Consultation with MBBS doctors was low at 14%. Given the morbidity level observed during the survey it was calculated that 250 physicians would be needed in Chakaria if the patients were to be attended by a qualified physician.</p> <p>Conclusions</p> <p>With the current shortage of physicians and level of production in the country it was asserted that it is very unlikely for Bangladesh to have adequate number of physicians in the near future. Thus, making use of existing healthcare providers, such as Village Doctors, could be considered a realistic option in dealing with the prevailing crisis.</p