CD20-mediated B cell depletion in acetylcholine receptor autoantibody-positive myasthenia gravis

Myasthenia gravis (MG) is an autoimmune disorder characterized by muscle weakness and fatigue, mediated in the majority of cases by IgG1 autoantibodies targeting the acetylcholine receptor (AChR). As AChR autoantibodies have been shown to be pathogenic, therapies targeting B cells have been applied in patients with AChR MG for more than a decade. Recently, a phase 2 trial of the CD20-targeting agent, rituximab, in AChR MG unfortunately failed to meet its primary endpoint. Converging data however from non-randomized clinical series, some of which with more participants than the phase 2 trial, support efficacy of rituximab in AChR MG, especially early onset disease. In this opinion article, we summarize both clinical data and mechanistic principles on the use of CD20 depletion therapy in AChR MG, which we believe lend support to the argument that CD20 depletion can still be a useful therapeutic strategy for patients with AChR MG

Aromatic plant Melissa officinalis extracts selectivity in various biomass crop and legume species

Saabunud / Received 17.06.2020 ; Aktsepteeritud / Accepted 10.07.2020 ; Avaldatud veebis / Published online 10.07.2020 ; Vastutav autor / Corresponding author: Panagiotis Kanatas e-mail: [email protected] effects of various plants can be exploited for use against weeds; however, the selectivity in different crops is also important. In the current study, the effects of lemon balm (Melissa officinalis) allelochemicals on seed germination and seedling emergence of three biomass crops and three legume species were evaluated. Seed germination of rapeseed was reduced by 19, 30, 56, and 80% in the concentrations of 1, 2, 5 and 10%, respectively, as compared to the control group, whereas sweet sorghum seeds showed a more intermediate response and sunflower germination was affected only by the highest concentration. Seed germination of common bean was by 25, 34 and 60% lower at 1, 2 and 5% extract concentrations, respectively, in comparison to the control whereas up to 85% reduction of seed germination was recorded in 10% concentration. Peanut seed germination percentage ranged between 72 and 47% of control in 5 and 10% concentrations, respectively, while soybean germination was least affected from M. officinalis leaf extracts since it was reduced by only 25 and 41% in 5 and 10% concentrations, respectively, as compared to the control. Seedling emergence of rapeseed was reduced by 14, 25, 46, and 79% in the concentrations of 1, 2, 5 and 10%, respectively, as compared to the control whereas lemon balm extracts showed increased selectivity on the sunflower. Soybean emergence was reduced by only 27 and 46% in 5 and 10% concentrations, respectively, in comparison to the control whereas common bean’s seedling emergence was reduced up to 35% even in 2% concentration. Allelopathic response index values confirmed that sunflower and rapeseed were the least and most sensitive biomass crops to lemon balm allelochemicals, respectively, whereas sweet sorghum showed an intermediate response. Increased was the selectivity of the aqueous leaf extracts on soybean, whereas seed germination and seedling emergence of peanut were more affected and common bean was the most sensitive crop. Further research is needed to investigate the selectivity of M. officinalis and other aromatic plants’ allelochemicals on various crops and under different soil and climatic conditions to optimize their efficacy as tools of more eco-friendly weed management strategies

Seed priming effects on germination and first growth of the medicinal plant Achillea millefolium L.

This study evaluated the effects of seed priming on germination and growth of A. millefolium by means of laboratory and greenhouse experiments conducted during 2018 in the Agricultural University of Athens. Treatments were GA3 (400 and 800 ppm), potassium nitrate (2% and 4%), polyethylene-glycol (soaking for 12 and 24h) besides an untreated control. Experiment in Petri dishes revealed that GA3 at 400 ppm, potassium nitrate (at concentration 2 and 4%) and PEG significantly increased germination percentage of A. millefolium, while germination rate was also significantly improved as a result of all seed priming techniques. In addition, due to the soil experiment, seedling emergence was significantly increased by GA3 at 400 ppm, potassium nitrate (at both concentrations) and PEG compared with the untreated seeds. Dry biomass of the young seedlings was significantly enhanced by means of GA3 (at 400 and 800 ppm), KNO3 (4%) and PEG for 24 h, indicating the potential effect of seed priming on first growth as well. The results of the present study revealed the significant positive effects of seed priming on A. millefolium seed germination, seedling emergence and early growth

Yield, quality and weed control in soybean crop as affected by several cultural and weed management practices

In the field of Agricultural University of Athens, the effects of false seedbed technique, stale seedbed, chemical and ecologically based control on weed growth and soybean yield were evaluated (2019). The experimental treatments were: normal seedbed, normal seedbed along with pre-emergence chemical control, false seedbed, stale seedbed with glyphosate and stale seedbed with pelargonic acid. In the plots of normal seedbed along with pre-emergence chemical control, pendimethalin was applied at rate of 1560 g a.i. ha-1. In the plots of stale seedbed with glyphosate, glyphosate was applied at a rate of 2160 g a.e. ha-1 and in the plots of stale seedbed with pelargonic acid, pelargonic acid was applied at a rate of 31020 g a.i. ha-1. The experiment was conducted in a randomized complete block design with three replicates. The results revealed that stale seedbed combined either with glyphosate or pelargonic acid application reduced annual weeds’ density by 94 and 95% as compared to normal seedbed. Stale seedbed along with pelargonic acid reduced the density of perennial weeds by 36, 38 and 41% as compared to the combination of normal seedbed and pre-emergence chemical control, normal seedbed and false seedbed, respectively. The application of glyphosate in stale seedbed plots was also effective against perennial weeds. It was also observed that stale seedbed along with glyphosate increased soybean seed yield by 17, 19 and 35% as compared to the combination of normal seedbed and pendimethalin application, false seedbed and normal seedbed, respectively. Beneficial were also the effects of the combination of stale seedbed and pelargonic acid not only on soybean seed yield but also on soybean protein content. Further research is needed in order to investigate the role of false and stale seedbeds as integrated weed management practices in various crops and under different soil and climatic conditions. Research is also needed to evaluate pelargonic acid for weed control in stale seedbeds since it is an eco-friendly herbicide with no restrictions for organic farming

The effects of tillage on weed suppressive ability, leaf area, seed yield and protein content of Mucuna pruriens var. utilis

In the field of the Agricultural University of Athens, the effects of tillage on weed suppressive ability, leaf area, seed yield and protein content of velvet bean (Mucuna pruriens) were evaluated under the climatic conditions of Greece. The experiment was carried out in a randomized complete block design with three replicates. The three experimental treatments were: control (untreated), one hoeing for weed seedlings’ elimination at 7 days after sowing, and two hoeings for weed seedlings’ elimination at 7 and 15 days after sowing. Findings revealed that one hoeing reduced annual weeds’ density by 42% as compared to control treatment. Two hoeings resulted in a 47% lower density for annual species as compared to the untreated check. The density of perennial weeds recorded in the plots of one-hoeing treatment was 52% lower than the value recorded in the plots of control treatment. It was also shown that two hoeings can result in a 61% lower density regarding perennial species. Regarding velvet bean’s vegetation growth, one hoeing increased velvet bean leaf area per plant by 26% whereas, in the plots of two-hoeings treatment, the value of leaf area per plant was by 22-36% higher than the corresponding value recorded in untreated control plots. Two hoeings can increase velvet beans seed yield by 44% as well as seeds’ protein content by 17%. Further research is needed to optimize the use of velvet bean as a cover crop and seek for agronomic practices that might enhance its competitiveness against both annual and perennial weed species

Growth Analysis of Quinoa (Chenopodium quinoa Willd.) in Response to Fertilization and Soil Tillage

Growth analysis is an appropriate method for plant response to various environmental and cultural conditions during plant life. A 2-year experiment was conducted to evaluate the effect of soil tillage and fertilization on the growth and growth parameters of quinoa crop and to determine the association between yield and growth characteristics at both the single plant and crop stand level. The experiment was laid out in a split-plot design with two replicates, two main plots [conventional (CT) and minimum tillage (MT)] and four sub-plots [fertilization treatments: untreated, inorganic fertilization of 100 (N1) and 200 kg N ha-1 (N2) and sheep manure]. The highest absolute growth rate (AGR) and crop growth rate (CGR) values were recorded between the middle of vegetative growth stage and the beginning of anthesis (50-75 DAS) under conventional tillage coupled with manure (AGR: 0.4577 g day-1, CGR: 11.44 g m-2 day-1) and with N2 treatment (AGR: 0.4521 g day-1, CGR: 11.31 g m-2 day-1). Concerning specific leaf area (SLA), the highest value (150.58 cm2 g-1) was found at 75 DAS in N2 treatment. Leaf area index (LAI) were positively affected by soil tillage and fertilization with greatest values found under conventional tillage coupled with N2 treatment (5.110 m2 m-2). The highest seed yield was observed in N2 treatment (2488 and 2388 kg ha-1 under CT and MT, respectively). As a conclusion, the cultivation under conventional tillage and the increasing levels of applied nitrogen up to 200 kg N ha-1 increases crop growth and yield

Key aspects on the biology, ecology and impacts of johnsongrass [Sorghum halepense (L.) Pers] and the role of glyphosate and non-chemical alternative practices for the management of this weed in Europe

Sorghum halepense (L.) Pers is a common and noxious worldwide weed of increasing distribution in many European countries. In the present review, information on the biology, ecology, agricultural, economic and environmental impact of johnsongrass is given, and the current status of this weed in Europe is discussed. Furthermore, special attention is given to the important role of field trials using glyphosate to control weeds in arable and perennial crops in many European countries. Some of the factors which affect control efficacy and should be taken into account are also discussed. Finally, several non-chemical alternative methods (cultural, mechanical, thermal, biological, etc.) for johnsongrass management are also presented. The adoption of integrated weed management (IWM) techniques such as glyphosate use, crop rotation, and deep tillage is strongly recommended to control plant species that originate from both seed and rhizomes.This research was funded by Bayer Agriculture BVBA, grant number 140319

Changes of Weed Flora due to Nitrogen Addition in Sunflower

A field trial was conducted in Domokos region, in central Greece with Helianthus annuus, hybrid ‘LG 5658’ in order to evaluate the effects of different N fertilization and weed control methods on sunflower yield and weed flora. ANOVA showed that the interaction of fertilization and weed control had a significant effect on grain yield. Moreover, this study revealed that the density of the common weeds Amaranthus retroflexus, Abutilon theophrasti, Xanthium strumarium and Echinochloa crus-galli was increased by 60, 40, 33 and 23% in the plots of high N rate without any herbicide use. On the contrary, weeds like Datura stramonium and Convolvulus arvensis were not significantly affected by fertilization. This different responsiveness of the several weed species could be further exploited through programs of integrated crop and weed management. Moreover, our findings related to the differences in herbicide efficacy resulting from different N levels may alter weed flora and explain possible weed control failures

Can Control of Glyphosate Susceptible and Resistant Conyza sumatrensis Populations Be Dependent on the Herbicide Formulation or Adjuvants?

In this work, we studied the effect of three glyphosate formulations (isopropylamine, ammonium and potassium salts) and two non-ionic adjuvants on the resistance response of two resistant (R1, R2) and one susceptible population of the highly invasive Asteraceae, Conyza sumatrensis, from Southern France vineyards. Only in R1, an amino acid substitution (Pro106Thr) was found in the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS). The two adjuvants, in a similar fashion, significantly reduced GR50 values for every population and glyphosate formulation. Without adjuvants, glyphosate as potassium salt was the only formulation able to significantly reduce the GR50 values of every population. For every population, the two adjuvants improved, indistinguishably, leaf retention of the herbicidal solution and the potassium salt formulation led to the highest retention, both with and without the adjuvant added. Uptake responses paralleled those of retention and adjuvant addition was more effective in increasing foliar uptake of the lower performing formulations (isopropylamine and ammonium salts). The allocation pattern of glyphosate among plant compartments was only dependent on population, with R2 retaining most glyphosate in the treated leaf, clearly suggesting the occurrence of a Non-Target Site Resistance (NTSR) mechanism. Results indicate that control of weed populations possessing NTSR mechanisms of resistance to glyphosate may be improved through adequate selection of formulation and adjuvant use