A cornucopia of diversity-Ranunculales as a model lineage

The Ranunculales are a hyperdiverse lineage in many aspects of their phenotype, including growth habit, floral and leaf morphology, reproductive mode, and specialized metabolism. Many Ranunculales species, such as opium poppy and goldenseal, have a high medicinal value. In addition, the order includes a large number of commercially important ornamental plants, such as columbines and larkspurs. The phylogenetic position of the order with respect to monocots and core eudicots and the diversity within this lineage make the Ranunculales an excellent group for studying evolutionary processes by comparative studies. Lately, the phylogeny of Ranunculales was revised, and genetic and genomic resources were developed for many species, allowing comparative analyses at the molecular scale. Here, we review the literature on the resources for genetic manipulation and genome sequencing, the recent phylogeny reconstruction of this order, and its fossil record. Further, we explain their habitat range and delve into the diversity in their floral morphology, focusing on perianth organ identity, floral symmetry, occurrences of spurs and nectaries, sexual and pollination systems, and fruit and dehiscence types. The Ranunculales order offers a wealth of opportunities for scientific exploration across various disciplines and scales, to gain novel insights into plant biology for researchers and plant enthusiasts alike.

Phase I study of peposertib and avelumab with or without palliative radiotherapy in patients with advanced solid tumors

INTRODUCTION

We report results from a phase I, three-part, dose-escalation study of peposertib, a DNA-dependent protein kinase inhibitor, in combination with avelumab, an immune checkpoint inhibitor, with or without radiotherapy in patients with advanced solid tumors.

MATERIALS AND METHODS

Peposertib 100-400 mg twice daily (b.i.d.) or 100-250 mg once daily (q.d.) was administered in combination with avelumab 800 mg every 2 weeks in Part A or avelumab plus radiotherapy (3 Gy/fraction × 10 days) in Part B. Part FE assessed the effect of food on the pharmacokinetics of peposertib plus avelumab. The primary endpoint in Parts A and B was dose-limiting toxicity (DLT). Secondary endpoints were safety, best overall response per RECIST version 1.1, and pharmacokinetics. The recommended phase II dose (RP2D) and maximum tolerated dose (MTD) were determined in Parts A and B.

RESULTS

In Part A, peposertib doses administered were 100 mg (n = 4), 200 mg (n = 11), 250 mg (n = 4), 300 mg (n = 6), and 400 mg (n = 4) b.i.d. Of DLT-evaluable patients, one each had DLT at the 250-mg and 300-mg dose levels and three had DLT at the 400-mg b.i.d. dose level. In Part B, peposertib doses administered were 100 mg (n = 3), 150 mg (n = 3), 200 mg (n = 4), and 250 mg (n = 9) q.d.; no DLT was reported in evaluable patients. Peposertib 200 mg b.i.d. plus avelumab and peposertib 250 mg q.d. plus avelumab and radiotherapy were declared as the RP2D/MTD. No objective responses were observed in Part A or B; one patient had a partial response in Part FE. Peposertib exposure was generally dose proportional.

CONCLUSIONS

Peposertib doses up to 200 mg b.i.d. in combination with avelumab and up to 250 mg q.d. in combination with avelumab and radiotherapy were tolerable in patients with advanced solid tumors; however, antitumor activity was limited.

CLINICALTRIALS

GOV IDENTIFIER

NCT03724890.

Factors associated with return-to-work outcomes in inpatient rehabilitation - a systematic scoping review

Inpatient rehabilitation is common in Germany to improve return-to-work outcomes. The objective of this systematic scoping review was to identify factors associated with return-to-work outcomes in musculoskeletal, psychological and oncological health conditions to improve tailoring of rehabilitation therapies. A search was completed in Embase, Medline, PsycInfo and AMED until May 2023 for articles investigating inpatient rehabilitation including working-age patients with oncological, musculoskeletal, or psychological diseases using a quantitative design and reporting factors associated with return-to-work outcomes. Screening of all titles and abstracts was completed by one reviewer, full texts were read by two reviewers. Quality appraisal and data extraction was completed by two reviewers. Data was analysed using a narrative synthesis. Eighteen studies of moderate quality were included. The review identified a wide range of return-to-work parameters including employment status, work ability, sickness absence, retirement status and duration of employment since rehabilitation. In addition, 48 psychological, health- and work-related factors associated with return-to-work parameters were identified. Only one RCT investigated the relationship between a depression prevention intervention and a return-to-work outcome (work ability), which showed a significant effect. In addition to the depression prevention intervention, only the factor 'health literacy' could be considered modifiable and be addressed as part of an inpatient rehabilitation programme. Furthermore, gradual work reintegration programs and/or workplace interventions in addition to inpatient rehabilitation should be further explored to improve return-to-work outcomes.

Detection Rates of Mild Cognitive Impairment in Primary Care for the United States Medicare Population

BACKGROUND

Existing evidence points to substantial gaps in detecting mild cognitive impairment in primary care but is based on limited or self-reported data. The recent emergence of disease-modifying treatments for the Alzheimer's disease, the most common etiology of mild cognitive impairment, calls for a systematic assessment of detection rates in primary care.

OBJECTIVES

The current study aims to examine detection rates for mild cognitive impairment among primary care clinicians and practices in the United States using Medicare claims and encounter data.

DESIGN

Observational study.

SETTING

Medicare administrative data.

PARTICIPANTS

The study sample includes a total of 226,756 primary care clinicians and 54,597 practices that had at least 25 patients aged 65 or older, who were enrolled in Medicare fee-for-service or a Medicare Advantage plan between 2017 and 2019.

MEASUREMENTS

The detection rate for mild cognitive impairment is assessed as the ratio between the observed diagnosis rate of a clinician or practice as documented in the data, and the expected rate based on a predictive model.

RESULTS

The average detection rates for mild cognitive impairment is 0.08 (interquartile range=0.00-0.02) for both clinicians and practices, suggesting that only about 8% of expected cases were diagnosed on average. Only 0.1% of clinicians and practices had diagnosis rates within the expected range.

CONCLUSIONS

Mild cognitive impairment is vastly underdiagnosed, pointing to an urgent need to improve early detection in primary care.

Efficacy of a computer based discontinuation strategy to reduce PPI prescriptions: a multicenter cluster-randomized controlled trial

Deprescribing of inappropriate long-term proton pump inhibitors (PPI) is challenging and there is a lack of useful methods for general practitioners to tackle this. The objective of this randomized controlled trial was to evaluate the effectiveness of the electronic decision aid tool arriba-PPI on reduction of long-term PPI intake. Participants (64.5 ± 12.9 years; 54.4% women) with a PPI intake of at least 6 months were randomized to receive either consultation with arriba-PPI from their general practitioner (n = 1256) or treatment as usual (n = 1131). PPI prescriptions were monitored 6 months before, 6 and 12 months after study initiation. In 49.2% of the consultations with arriba-PPI, the general practitioners and their patients made the decision to reduce or discontinue PPI intake. At 6 months, there was a significant reduction by 22.3% (95% CI 18.55 to 25.98; p < 0.0001) of defined daily doses (DDD) of PPI. A reduction of 3.3% (95% CI - 7.18 to + 0.62) was observed in the control group. At 12 months, the reduction of DDD-PPI remained stable in intervention patients (+ 3.5%, 95% CI - 0.99 to + 8.03), whereas control patients showed a reduction of DDD-PPI (- 10.2%, 95% CI - 6.01 to - 14.33). Consultation with arriba-PPI led to reduced prescription rates of PPI in primary care practices. Arriba-PPI can be a helpful tool for general practitioners to start a conversation with their patients about risks of long-term PPI intake, reduction or deprescribing unnecessary PPI medication.

Evolution and development of fruits of Erycina pusilla and other orchid species

Fruits play a crucial role in seed dispersal. They open along dehiscence zones. Fruit dehiscence zone formation has been intensively studied in Arabidopsis thaliana. However, little is known about the mechanisms and genes involved in the formation of fruit dehiscence zones in species outside the Brassicaceae. The dehiscence zone of A. thaliana contains a lignified layer, while dehiscence zone tissues of the emerging orchid model Erycina pusilla include a lipid layer. Here we present an analysis of evolution and development of fruit dehiscence zones in orchids. We performed ancestral state reconstructions across the five orchid subfamilies to study the evolution of selected fruit traits and explored dehiscence zone developmental genes using RNA-seq and qPCR. We found that erect dehiscent fruits with non-lignified dehiscence zones and a short ripening period are ancestral characters in orchids. Lignified dehiscence zones in orchid fruits evolved multiple times from non-lignified zones. Furthermore, we carried out gene expression analysis of tissues from different developmental stages of E. pusilla fruits. We found that fruit dehiscence genes from the MADS-box gene family and other important regulators in E. pusilla differed in their expression pattern from their homologs in A. thaliana. This suggests that the current A. thaliana fruit dehiscence model requires adjustment for orchids. Additionally, we discovered that homologs of A. thaliana genes involved in the development of carpel, gynoecium and ovules, and genes involved in lipid biosynthesis were expressed in the fruit valves of E. pusilla, implying that these genes may play a novel role in formation of dehiscence zone tissues in orchids. Future functional analysis of developmental regulators, lipid identification and quantification can shed more light on lipid-layer based dehiscence of orchid fruits.

Oncogenic Activities of Tribbles1 (TRIB1) Pseudokinase Overexpressed in GBM are Mediated by Protein-Protein Interactions

PURPOSE/OBJECTIVE(S)

Glioblastoma (GBM) is the most aggressive form of glioma with a low 5-year survival rate. The current treatments are inadequate and crippled by therapy resistance. Therefore, there is an unmet need to identify druggable therapeutic targets in GBM. In this study we identified TRIB1, a Ser/Thr pseudokinase that acts as a scaffold to initiate Ubiquitin Proteasome System-mediated degradation of its substrates. We and others have found that TRIB1 activates the canonical MAPK and Akt signaling cascades. Previous reports also suggest that TRIB1 contributes to chemotherapy resistance in various cancers. Therefore, we evaluated oncogenic roles of TRIB1 in GBM cells and its contribution to therapy resistance.

MATERIALS/METHODS

Patient-centered reverse translational approach was utilized to identify novel therapeutic targets. To this end, TRIB1 was identified by statistical association (Cox regression analysis) of the patient-derived gene expression profiling data publicly available from TCGA GBM cohort. TRIB1 was functionally validated in vitro by generating stable overexpression cell lines (patient-derived) by antibiotic selection. Conditional knockdown of TRIB1 was achieved by doxycycline induction. Protein-protein interactions were evaluated by co-immunoprecipitation. Protein levels were detected by western blotting. Changes in tumor volume and overall survival (OS) were calculated.

RESULTS

The mRNA profiling of TCGA GBM cohort revealed that increased TRIB1 gene expression was associated with worse OS of GBM patients [HR = 1.3 (1.0-1.5); P = 0.019]. The same analyses in our institutional cohort revealed a similar association. Mice bearing TRIB1 transgene overexpressing tumors had the increased tumor volume and shorter OS compared to empty vector control at the end of experiment. Overexpression of TRIB1 increased the phosphorylation/activation of ERK and Akt in patient-derived primary cell lines. Akt but not ERK activation was decreased after TRIB1 knockdown. TRIB1 bound directly to ERK and Akt in these cells. TRIB1 also formed a complex with p53, COP1 and HDAC1 in patient-derived primary cell lines. This protein-protein interaction was independent of TP53 mutation status.

CONCLUSION

Our data suggest that TRIB1 overexpressed in GBM executes various oncogenic functions through interaction with different proteins. Activating ERK signaling, can induce cell proliferation. Similarly, by activating Akt it can cause prosurvival effects. Finally, by associating with HDAC1 and COP1, TRIB1 can modulate p53 function. All these protein-protein interactions ultimately contribute to chemoradiotherapy resistance in GBM cells. We are currently developing small molecule inhibitors targeting the above-mentioned interactions of TRIB1 to overcome therapeutic resistance.

Hypoxia-Inducible Transgelin-2 Confers Treatment Resistance through Activation of PI3K/Akt/GSK3β Pathway in Glioblastoma

PURPOSE/OBJECTIVE(S)

Glioblastoma (GBM) patients with wild-type IDH experience worse survival response to the standard treatment of surgery followed by radiation therapy (RT) and temozolomide (TMZ) chemotherapy compared to their mutant IDH counterparts. This treatment has remained relatively ineffective partly due to the highly invasive phenotype of GBM leading to therapeutic resistance and tumor recurrence. Hypoxia is one of the key characteristic features of GBM which results in cancer metastasis and confers treatment resistance. Therefore, it is paramount to identify targets to help overcome hypoxia-induced treatment resistance in glioblastoma. Our lab has identified transgelin-2 (TAGLN2) to be significantly upregulated in IDH-wt GBM through multiple molecular profiling studies. This study aims to understand the mechanisms by which TAGLN2 confers treatment resistance for developing additional treatments for GBM. Additionally, active drug development efforts are also underway to target TAGLN2 for circumventing these therapeutic resistance mechanisms for effective GBM therapy.

MATERIALS/METHODS

RNAi-mediated TAGLN2 knockdown (KD) approach was employed to assess the functions of TAGLN2 in GBM patient-derived xenograft (PDX) cell lines. Series of in vitro functional assays were performed to assess the role of TAGLN2 in these cell lines. Cell proliferation, invasion ± RT and/or TMZ were assessed by MTS and Trans-well invasion assays. Subsequently, WB analysis of oncogenic signaling pathways was performed following Transgelin-2 KD. Co-IP assays and Biacore/SPR analyses were performed to study the binding affinity and kinetics for the interaction of PTEN with TAGLN2. Further, cells were intracranially implanted in nude mice to assess the role of TAGLN2 on tumor growth in vivo.

RESULTS

Conditional KD of TAGLN2 reduces cell proliferation, survival and invasive potential of GBM PDX cell lines. TAGLN2 KD also improved the sensitivity of these cells to both TMZ and radiation in vitro, as assessed by proliferation, survival, clonal expansion, and invasion. Histopathological studies of human GBM tumors and mouse xenograft tumors showed elevated expression of TAGLN2 in the peri-necrotic region of the tumors indicating that TAGLN2 protein level was upregulated by hypoxia. We also show that TAGLN2 is induced in hypoxic microenvironments with GBM PDX cell lines and its overexpression may enhance cellular resistance towards conventional therapy. Subsequently, we also show that hypoxia-induced TAGLN2 activates the PI3K/Akt oncogenic pathway through binding and inhibition of PTEN. Finally, in vivo data using an orthotopic xenograft mouse model shows reduction of tumor growth with knockdown of TAGLN2.

CONCLUSION

Our in vitro and in vivo xenograft studies suggest that TAGLN2 confers treatment resistance to GBM contributing to tumor recurrence. Altogether, TAGLN2 may serve as a potential therapeutically vulnerable target in GBM specifically through its role in cell survival and invasion.

Enabling elliptically polarized high harmonic generation with short cross polarized laser pulses

Enabling elliptically polarized high-order harmonics overcomes a historical limitation in the generation of this highly nonlinear process in atomic, molecular and optical physics with applications in other branches. Here, we shed new light on a controversy between experimental observations and theoretical predictions on the possibility to generate harmonics with large ellipticity using two bichromatic laser pulses which are linearly polarized in orthogonal directions. Results of numerical calculations confirm the previous experimental data that in short laser pulses even harmonics with large ellipticity can be obtained for the interaction of such cross-polarized laser pulses with atoms initially in a s- or p-state, while odd harmonics have low ellipticity. The amount of the ellipticity can be controlled via the relative carrier-envelope phase of the pulses, their intensity ratio and the duration of the pulses.

Convergent evolution of plant pattern recognition receptors sensing cysteine-rich patterns from three microbial kingdoms

The Arabidopsis thaliana Receptor-Like Protein RLP30 contributes to immunity against the fungal pathogen Sclerotinia sclerotiorum. Here we identify the RLP30-ligand as a small cysteine-rich protein (SCP) that occurs in many fungi and oomycetes and is also recognized by the Nicotiana benthamiana RLP RE02. However, RLP30 and RE02 share little sequence similarity and respond to different parts of the native/folded protein. Moreover, some Brassicaceae other than Arabidopsis also respond to a linear SCP peptide instead of the folded protein, suggesting that SCP is an eminent immune target that led to the convergent evolution of distinct immune receptors in plants. Surprisingly, RLP30 shows a second ligand specificity for a SCP-nonhomologous protein secreted by bacterial Pseudomonads. RLP30 expression in N. tabacum results in quantitatively lower susceptibility to bacterial, fungal and oomycete pathogens, thus demonstrating that detection of immunogenic patterns by Arabidopsis RLP30 is involved in defense against pathogens from three microbial kingdoms.

Conservation of the restricted expression of Brassicaceae Bsister-like genes in seeds requires a transposable element in Arabidopsis thaliana

Changes in transcription factor binding sites (TFBSs) can alter the spatio-temporal expression pattern and transcript abundance of genes. Loss and gain of TFBSs were shown to cause shifts in expression patterns in numerous cases. However, we know little about the evolution of extended regulatory sequences incorporating many TFBSs. We compare, across the crucifers (Brassicaceae, cabbage family), the sequences between the translated regions of Arabidopsis Bsister- (ABS-) like MADS-box genes (including paralogous GOA-like genes) and the next gene upstream, as an example of family wide evolution of putative regulatory regions (PURRs). ABS-like genes are essential for integument development of ovules and endothelium formation in seeds of Arabidopsis thaliana. A combination of motif based GO-enrichment and reporter gene analysis using A. thaliana as common trans-regulatory environment allows analysis of selected Brassicaceae Bsister gene PURRs. Comparison of TFBS of transcriptionally active ABS-like genes with those of transcriptionally largely inactive GOA-like genes shows that the number of in silico predicted TF binding sites (TFBSs) is similar between paralogs, emphasizing the importance of experimental verification for in silico characterization of TFBS activity and analysis of their evolution. Further, our data show highly conserved expression of Brassicaceae ABS-like genes almost exclusively in the chalazal region of ovules. The Arabidopsis-specific insertion of a transposable element (TE) into the ABS PURRs is required for stabilizing this spatially restricted expression, while other Brassicaceae achieve chalaza-specific expression without TE insertion. We hypothesize that the chalaza-specific expression of ABS is regulated by CREs provided by the TE.

California poppy (Eschscholzia californica), the Papaveraceae golden girl model organism for evodevo and specialized metabolism

California poppy or golden poppy (Eschscholzia californica) is the iconic state flower of California, with native ranges from Northern California to Southwestern Mexico. It grows well as an ornamental plant in Mediterranean climates, but it might be invasive in many parts of the world. California poppy was also highly prized by Native Americans for its medicinal value, mainly due to its various specialized metabolites, especially benzylisoquinoline alkaloids (BIAs). As a member of the Ranunculales, the sister lineage of core eudicots it occupies an interesting phylogenetic position. California poppy has a short-lived life cycle but can be maintained as a perennial. It has a comparatively simple floral and vegetative morphology. Several genetic resources, including options for genetic manipulation and a draft genome sequence have been established already with many more to come. Efficient cell and tissue culture protocols are established to study secondary metabolite biosynthesis and its regulation. Here, we review the use of California poppy as a model organism for plant genetics, with particular emphasis on the evolution of development and BIA biosynthesis. In the future, California poppy may serve as a model organism to combine two formerly separated lines of research: the regulation of morphogenesis and the regulation of secondary metabolism. This can provide insights into how these two integral aspects of plant biology interact with each other.

Patients' perspectives on a patient-oriented electronic decision support tool to reduce overuse of proton pump inhibitors (arriba-PPI): a qualitative study in primary care

BACKGROUND

To evaluate patients' perspectives and their experiences with a consultation involving a computer-assisted and patient-centered discontinuation strategy (arriba-PPI tool) as part of a German multicenter study on reducing the prescription of proton pump inhibitors (PPIs).

METHODS

Qualitative in-depth telephone interviews on proton pump inhibitors with patients who had received an arriba-PPI tool-based counseling by their general practitioner (GP). A random sample of 30 patients was taken from study participants. Interviews were conducted in 2020 and analyzed using a thematic qualitative text analysis.

RESULTS

Although this was meant to be the key to shared decision making with regard to PPI reduction, study participants mostly did not recall the visual features of the tool. However, a few patients remembered them very clearly. Above all, patients appreciated a trustful relationship with the GP as well as comprehensive, individualized counseling.

CONCLUSION

Application of the arriba-PPI tool can support the decision process but can also hinder the consultation process if the tool is not properly embedded in the consultation. GPs using the arriba-PPI tool to support the shared decision-making process should consider the patients' and their own expectations on the benefit of the visual representation of the tool.

Genotyping by sequencing and a newly developed mRNA-GBS approach to link population genetic and transcriptome analyses reveal pattern differences between sites and treatments in red clover (Trifolium pratense L.)

The important worldwide forage crop red clover (Trifolium pratense L.) is widely cultivated as cattle feed and for soil improvement. Wild populations and landraces have great natural diversity that could be used to improve cultivated red clover. However, to date, there is still insufficient knowledge about the natural genetic and phenotypic diversity of the species. Here, we developed a low-cost complexity reduced mRNA analysis (mRNA-GBS) and compared the results with population genetic (GBS) and previously published mRNA-Seq data, to assess whether analysis of intraspecific variation within and between populations and transcriptome responses is possible simultaneously. The mRNA-GBS approach was successful. SNP analyses from the mRNA-GBS approach revealed comparable patterns to the GBS results, but due to site-specific multifactorial influences of environmental responses as well as conceptual and methodological limitations of mRNA-GBS, it was not possible to link transcriptome analyses with reduced complexity and sequencing depth to previously published greenhouse and field expression studies. Nevertheless, the use of short sequences upstream of the poly(A) tail of mRNA to reduce complexity are promising approaches that combine population genetics and expression profiling to analyze many individuals with trait differences simultaneously and cost-effectively, even in non-model species. Nevertheless, our study design across different regions in Germany was also challenging. The use of reduced complexity differential expression analyses most likely overlays site-specific patterns due to highly complex plant responses under natural conditions.

Dynamic genome evolution in a model fern

The large size and complexity of most fern genomes have hampered efforts to elucidate fundamental aspects of fern biology and land plant evolution through genome-enabled research. Here we present a chromosomal genome assembly and associated methylome, transcriptome and metabolome analyses for the model fern species Ceratopteris richardii. The assembly reveals a history of remarkably dynamic genome evolution including rapid changes in genome content and structure following the most recent whole-genome duplication approximately 60 million years ago. These changes include massive gene loss, rampant tandem duplications and multiple horizontal gene transfers from bacteria, contributing to the diversification of defence-related gene families. The insertion of transposable elements into introns has led to the large size of the Ceratopteris genome and to exceptionally long genes relative to other plants. Gene family analyses indicate that genes directing seed development were co-opted from those controlling the development of fern sporangia, providing insights into seed plant evolution. Our findings and annotated genome assembly extend the utility of Ceratopteris as a model for investigating and teaching plant biology.

Murine typhus complicated by sHLH mimicking adult-onset Still's disease

INTRODUCTION

Adult-onset Still's disease (AOSD) is a rare multisystemic disorder and a diagnostic challenge for physicians because of the wide range of differential diagnoses. Common features of AOSD and secondary hemophagocytic lymphohistiocytosis (sHLH) could favour diagnostic uncertainty, in particular in case of infection-related sHLH.

OBSERVATION

A 61-year-old man was admitted to our internal medicine department for suspected AOSD. He reported a 2-week history of sudden onset fever, headaches, myalgia, sore throat, diarrhoea, and an erythematous macular rash of the trunk as well as petechial purpuric lesions on both legs on return from Reunion Island. Laboratory tests found cytopenia, hepatic cytolysis, hypertriglyceridaemia, and hyperferritinaemia. Hemophagocytosis was diagnosed on bone marrow aspiration in favour of the diagnosis of secondary hemophagocytic lymphohistiocytosis (sHLH). Subcutaneous anakinra (100mg) was initiated to treat sHLH with favourable course. Oral doxycycline was added 3days later because of atypical features for AOSD diagnosis such as diarrhoea, hypergammaglobulinaemia, and doubtful serologies for Rickettsia and Coxiella. Three weeks later, Rickettsia typhi serology was checked again and revealed an increase in IgG titer>4 times that confirmed the diagnosis of murine typhus. A diagnosis of murine typhus complicated by sHLH was retained, successfully treated by anakinra and doxycycline.

CONCLUSION

Our observation shows that AOSD diagnosis has to be stringent due to the many differential diagnoses, particularly infection complicated by sHLH, which may be rare. It is important to consider murine typhus in patients returning from endemic areas, such as La Reunion or other tropical areas, when they present fever of unknown origin with non-specific clinical features. Moreover, this case illustrates the effectiveness of IL-1 blockers as a treatment for symptomatic sHLH without severity criteria, regardless of the aetiology.

POS0755 SAFETY, TOLERABILITY, PHARMACOKINETICS, AND PHARMACODYNAMICS OF A SINGLE ORALLY ADMINISTERED DOSE OF ENPATORAN IN A PHASE I STUDY OF HEALTHY JAPANESE AND CAUCASIAN PARTICIPANTS

Background

Enpatoran, a novel, highly selective and potent dual toll-like receptor (TLR) 7 and TLR8 inhibitor, is in development for the treatment of autoimmune disorders including systemic and cutaneous lupus erythematosus. A first-in-human study in healthy participants has shown that enpatoran is well-tolerated and has a linear pharmacokinetic (PK) profile.

Objectives

To compare the PK parameters, safety, and tolerability of single ascending oral doses of enpatoran in a Phase I study in Japanese and Caucasian participants, and to explore a potential PK/pharmacodynamic (PD) relationship.

Methods

A single-centre, open-label, sequential dose group study enrolled healthy Japanese and Caucasian participants into three dose cohorts. Each Caucasian participant was matched by body weight (± 20%), height (± 15%) and sex to a Japanese participant. Participants received a single orally administered enpatoran dose of 100 mg, 200 mg, or 300 mg as a film-coated tablet under fasting conditions. PK parameters, (maximum plasma concentration [Cmax]; area under the plasma concentration–time curve (AUC) from time 0 to infinity [AUC0-inf]; AUC from time 0 to the last sampling time [AUC0-tlast]) determined using noncompartmental analysis, were estimated post-dose from Day 1–3. Safety was assessed from Day -1 to 8. PK (exposure) between the two ethnic groups was compared using an analysis of covariance (ANCOVA) model including ethnic group, natural log-transformed dose, and ethnic group by natural log dose interaction. Ex vivo secretion of cytokines (PD) under stimulated (using the TLR7/8 agonist, R848) and unstimulated conditions, was assessed pre- and post-dose. A panel of cytokines was analysed by multiplex immunoassay; IL-6 was considered the primary PD biomarker.

Results

The study included 36 male participants (18 Japanese and 18 Caucasian) with a mean (± SD) age of 35.1 (± 10.8) years and mean (± SD) body mass index of 23.1 (± 2.1) kg/m2. Each dose group included six Japanese and six Caucasian participants. The geometric mean enpatoran plasma exposure parameters (Cmax, AUC0-inf, and AUC0-tlast) were consistent between the two ethnic groups for each dose level (Table 1) and indicated dose proportionality. ANCOVA modeling demonstrated comparable exposure between the two groups (geometric least square mean ratio [Japanese/Caucasian;90% CI] of Cmax: 0.9409 [0.7855–1.1270]; AUC0-inf: 0.8959 [0.7497–1.0704] and AUC0-tlast: 0.8963 [0.7511–1.0695]). Treatment-emergent adverse events (TEAEs) were observed in six Japanese (n = 0, 100 mg; n = 3, 200 mg; n = 3, 300 mg) and four Caucasian (n = 1, 100 mg; n = 0, 200 mg; n = 3, 300 mg) participants. There we no serious TEAEs; most were mild and not dose dependent. Treatment-related TEAEs were mild diarrhoea, mild flatulence, and moderate headache. There were no deaths, withdrawals, or early terminations due to TEAEs. Administering enpatoran effectively reduced ex vivo stimulated cytokine release, with maximal inhibition observed at 2 hours post-dose (IL-6: mean ≥99%). High inhibition levels were sustained through 24 hours in a dose-dependent manner (IL-6: mean ~76–97%). The pattern of cytokine release inhibition was consistent across doses and ethnic groups.

Table 1.

PK parameters in Japanese and Caucasian participants at the three enpatoran dose levels

Parameter100 mg200 mg300 mgJapaneseCaucasianJapaneseCaucasianJapaneseCaucasianN = 6N = 6N = 6N = 6N = 6N = 6Cmax139175260245486490(ng/mL)AUC0-inf7749481910185028403330(h*ng/mL)AUC0-tlast7589311880183028103270(h*ng/mL)

All values are Geometric mean.

Cmax, maximum plasma concentration AUC0-inf, area under the plasma concentration–time curve (AUC) from time 0 to infinity; AUC0-tlast, AUC from time 0 to the last sampling time.

Conclusion

There were no relevant ethnic differences in PK, PD, and safety between healthy Japanese and Caucasian participants across a range of single oral enpatoran doses, thus supporting the inclusion of Asian participants in future global Phase II studies.

Acknowledgements

We would like to thank those who took part in the study. This study was sponsored by the healthcare business of Merck KGaA, Darmstadt, Germany (CrossRef Funder ID: 10.13039/100009945), who funded medical writing support by Bioscript Stirling Ltd.

Disclosure of Interests

Sathej Gopalakrishnan Shareholder of: Merck Healthcare KGaA, Employee of: Merck Healthcare KGaA, Axel Krebs-Brown Employee of: Merck Healthcare KGaA, Marco Nogueira Filho Employee of: Merck Healthcare KGaA, Yoshihiro Kuroki Employee of: Merck Biopharma Co., Ltd., Angelika Bachmann Employee of: Merck Healthcare KGaA, Andreas Becker Shareholder of: Merck Healthcare KGaA, Employee of: Merck Healthcare KGaA, Frank Schippers Employee of: Merck Healthcare KGaA, Markus Fluck Shareholder of: Merck Healthcare KGaA, Employee of: Merck Healthcare KGaA, Özkan Yalkinoglu Employee of: Merck Healthcare KGaA, Lena Klopp-Schulze Employee of: Merck Healthcare KGaA

Targeting CD73 with AB680 (Quemliclustat), a Novel and Potent Small-Molecule CD73 Inhibitor, Restores Immune Functionality and Facilitates Antitumor Immunity

T cells play a critical role in the control of cancer. The development of immune checkpoint blockers (ICB) aimed at enhancing antitumor T-cell responses has revolutionized cancer treatment. However, durable clinical benefit is observed in only a subset of patients, prompting research efforts to focus on strategies that target multiple inhibitory signals within the tumor microenvironment (TME) to limit tumor evasion and improve patient outcomes. Adenosine has emerged as a potent immune suppressant within the TME, and CD73 is the major enzyme responsible for its extracellular production. CD73 can be co-opted within the TME to impair T-cell-mediated antitumor immunity and promote tumor growth. To target this pathway and block the formation of adenosine, we designed a novel, selective, and potent class of small-molecule inhibitors of CD73, including AB680 (quemliclustat), which is currently being tested in patients with cancer. AB680 effectively restored T-cell proliferation, cytokine secretion, and cytotoxicity that were dampened by the formation of immunosuppressive adenosine by CD73. Furthermore, in an allogeneic mixed lymphocyte reaction where CD73-derived adenosine had a dominant suppressive effect in the presence of PD-1 blockade, AB680 restored T-cell activation and function. Finally, in a preclinical mouse model of melanoma, AB680 inhibited CD73 in the TME and increased the antitumor activity of PD-1 blockade. Collectively, these data provide a rationale for the inhibition of CD73 with AB680 in combination with ICB, such as anti-PD-1, to improve cancer patient outcomes.

VIGS Goes Viral: How VIGS Transforms Our Understanding of Plant Science

Virus-induced gene silencing (VIGS) has developed into an indispensable approach to gene function analysis in a wide array of species, many of which are not amenable to stable genetic transformation. VIGS utilizes the posttranscriptional gene silencing (PTGS) machinery of plants to restrain viral infections systemically and is used to downregulate the plant's endogenous genes. Here, we review the molecular mechanisms of DNA- and RNA-virus-based VIGS, its inherent connection to PTGS, and what is known about the systemic spread of silencing. Recently, VIGS-based technologies have been expanded to enable not only gene silencing but also overexpression [virus-induced overexpression (VOX)], genome editing [virus-induced genome editing (VIGE)], and host-induced gene silencing (HIGS). These techniques expand the genetic toolbox for nonmodel organisms even more. Further, we illustrate the versatility of VIGS and the methods derived from it in elucidating molecular mechanisms, using tomato fruit ripening and programmed cell death as examples. Finally, we discuss challenges of and future perspectives on the use of VIGS to advance gene function analysis in nonmodel plants in the postgenomic era.

Learning curve and functional outcomes after laser enucleation of the prostate for benign prostate hyperplasia according to surgeon's caseload

PURPOSE

To evaluate the impact of surgical caseload on safety, efficacy, and functional outcomes of laser enucleation of the prostate (LEP) applying a structured mentoring program.

METHODS

Patient characteristics, perioperative data, and functional outcomes were analyzed descriptively. Linear and logistic regression models analyzed the effect of caseload on complications, functional outcomes and operative speed. Within the structured mentoring program a senior surgeon was present for the first 24 procedures completely, for partial steps in procedures 25-49, and as needed thereafter.

RESULTS

A total of 677 patients from our prospective institutional database (2017-2022) were included for analysis. Of these, 84 (12%), 75 (11%), 82 (12%), 106 (16%), and 330 patients (49%) were operated by surgeons at (A) < 25, (B) 25-49, (C) 50-99, (D) 100-199, and (E) ≥ 200 procedures. Preoperative characteristics were balanced (all p > 0.05) except for prostate volume, which increased with caseload. There was no significant difference in change of IPSS, Quality of life, ICIQ, pad usage, peak urine flow, residual urine, and major complications (Group A: 8.3 to E: 7.6%, p = 0.2) depending on the caseload. Caseload was not associated (Odds ratio: 0.7-1.4, p > 0.2) with major complications in the multivariable logistic regression model. Only operating time was significantly shorter with increasing caseload in the multivariable analysis (111-55 min, beta 23.9-62.9, p < 0.001).

CONCLUSION

With a structured mentoring program, the safety and efficacy of LEP can be ensured even during the learning curve with very good outcome quality. Only the operating time decreases significantly with increasing experience of the surgeon.

Rehabilitation care planning on a digital communication platform for patients with a work disability: protocol for the RehaPro-SERVE feasibility study

Background

Long-term disability to work is a risk factor for a permanent reduction in income. Rehabilitation care can support people to return to work. In Germany, rehabilitation care to return to work is mostly provided in specialised clinics. The aim of the Rehapro-SERVE study is to reduce work disability days by facilitating rehabilitation care planning using a digital communication platform. To investigate the feasibility, we will test the implementation of the digital platform and evaluate the study procedures. The Rehapro-SERVE study is funded by the German Federal Ministry of Labour and Social Affairs (BMAS) (grant number: 661R0053K1).

Method

The feasibility study includes a two-armed unblinded block randomised controlled study (RCT) without follow-up assessments as well as an interview study. Participants for the RCT (n = 16) are primary care patients with a minimum of 4 weeks of absence from work due to musculoskeletal, oncological or psychological conditions and at high risk of early retirement. Eligibility criteria are age 40 to 60 years; minimum of 4 weeks continuous sick leave before recruitment due to musculoskeletal, mental health or oncological conditions; and being at high risk of early retirement. Patients will be recruited from 8 primary care practices in urban and rural areas in Hesse, Germany. Following baseline assessments, patients will be randomised to either digitalised care planning (treatment) or a control group. The digitalised care planning platform will include the patients’ primary care physicians, jobcentres and public health physicians to decide on a tailored return-to-work programme. The collaboration will be supported by a case administrator and, if considered beneficial, a social worker for the patient. An interview study will evaluate the acceptability of the study procedures and the intervention.

Discussion

The use of a digital communication platform enables stakeholders to exchange information and discuss rehabilitation care planning in a timely fashion. The results of the feasibility study will lead to the adaptation of study procedures for the main study. The results will support the design and conduct of similar studies including digital applications in primary care or across different healthcare settings.

Trial registration

DRKS- German Clinical Trials Register, DRKS00024207. Registered on 22 March 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00957-2.

Coherence in macroscopic high harmonic generation for spatial focal phase distributions of monochromatic and broadband Gaussian laser pulses

Efficient application of ultrafast laser sources from high harmonic generation requires an understanding of how the spectrum can be controlled - the extent of the highest harmonics and the strength and cleanness of the harmonic lines. We study one important aspect in the coherent build-up of macroscopic high-order harmonic generation, namely the impact of different phase distributions in the focal area on the features of the generated radiation. Specifically, we compare the high harmonic signals for the commonly-used Gouy distribution of a monochromatic beam with those for the phase distribution of a short broadband Gaussian pulse. To this end, we apply a theoretical model in which the microscopic yields are obtained via interpolation of results of the time-dependent Schrödinger equation, which are then used in an individual-emitter approach to determine the macroscopic signals. Regions of poor and good coherent build-up as a function of the position of the gas jet are identified using measures for the strength of the harmonic lines and for the impact of off-harmonic radiation. While the largest extent of the spectra as well as the strongest contribution of off-harmonic radiation is found for positioning the gas jet after the focus for both distributions, the relative strength of the harmonics is overall weaker for the short Gaussian pulse distribution and the spectra differ for a gas jet positioned at the focus. These differences are mainly caused by the additional dependence of the focal phase in the transverse direction for the short Gaussian pulse distribution.

Consolidation nivolumab and ipilimumab versus observation in limited-disease small-cell lung cancer after chemo-radiotherapy - results from the randomised phase II ETOP/IFCT 4-12 STIMULI trial

BACKGROUND

Concurrent chemotherapy and thoracic radiotherapy followed by prophylactic cranial irradiation (PCI) is the standard treatment in limited-disease small-cell lung cancer (LD-SCLC), with 5-year overall survival (OS) of only 25% to 33%.

PATIENTS AND METHODS

STIMULI is a 1:1 randomised phase II trial aiming to demonstrate superiority of consolidation combination immunotherapy versus observation after chemo-radiotherapy plus PCI (protocol amendment-1). Consolidation immunotherapy consisted of four cycles of nivolumab [1 mg/kg, every three weeks (Q3W)] plus ipilimumab (3 mg/kg, Q3W), followed by nivolumab monotherapy (240 mg, Q2W) for up to 12 months. Patient recruitment closed prematurely due to slow accrual and the statistical analyses plan was updated to address progression-free survival (PFS) as the only primary endpoint.

RESULTS

Of the 222 patients enrolled, 153 were randomised (78: experimental; 75: observation). Among the randomised patients, median age was 62 years, 60% males, 34%/65% current/former smokers, 31%/66% performance status (PS) 0/1. Up to 25 May 2020 (median follow-up 22.4 months), 40 PFS events were observed in the experimental arm, with median PFS 10.7 months [95% confidence interval (CI) 7.0-not estimable (NE)] versus 42 events and median 14.5 months (8.2-NE) in the observation, hazard ratio (HR) = 1.02 (0.66-1.58), two-sided P = 0.93. With updated follow-up (03 June 2021; median: 35 months), median OS was not reached in the experimental arm, while it was 32.1 months (26.1-NE) in observation, with HR = 0.95 (0.59-1.52), P = 0.82. In the experimental arm, median time-to-treatment-discontinuation was only 1.7 months. CTCAE v4 grade ≥3 adverse events were experienced by 62% of patients in the experimental and 25% in the observation arm, with 4 and 1 fatal, respectively.

CONCLUSIONS

The STIMULI trial did not meet its primary endpoint of improving PFS with nivolumab-ipilimumab consolidation after chemo-radiotherapy in LD-SCLC. A short period on active treatment related to toxicity and treatment discontinuation likely affected the efficacy results.

Prevalence, aetiologies and prognosis of the symptom cough in primary care: a systematic review and meta-analysis

Background

Cough is a relevant reason for encounter in primary care. For evidence-based decision making, general practitioners need setting-specific knowledge about prevalences, pre-test probabilities, and prognosis. Accordingly, we performed a systematic review of symptom-evaluating studies evaluating cough as reason for encounter in primary care.

Methods

We conducted a search in MEDLINE and EMBASE. Eligibility criteria and methodological quality were assessed independently by two reviewers. We extracted data on prevalence, aetiologies and prognosis, and estimated the variation across studies. If justifiable in terms of heterogeneity, we performed a meta-analysis.

Results

We identified 21 eligible studies on prevalence, 12 on aetiology, and four on prognosis. Prevalence/incidence estimates were 3.8–4.2%/12.5% (Western primary care) and 10.3–13.8%/6.3–6.5% in Africa, Asia and South America. In Western countries the underlying diagnoses for acute cough or cough of all durations were respiratory tract infections (73–91.9%), influenza (6–15.2%), asthma (3.2–15%), laryngitis/tracheitis (3.6–9%), pneumonia (4.0–4.2%), COPD (0.5–3.3%), heart failure (0.3%), and suspected malignancy (0.2–1.8%). Median time for recovery was 9 to 11 days. Complete recovery was reported by 40.2- 67% of patients after two weeks, and by 79% after four weeks. About 21.1–35% of patients re-consulted; 0–1.3% of acute cough patients were hospitalized, none died. Evidence is missing concerning subacute and chronic cough.

Conclusion

Prevalences and incidences of cough are high and show regional variation. Acute cough, mainly caused by respiratory tract infections, is usually self-limiting (supporting a “wait-and-see” strategy). We have no setting-specific evidence to support current guideline recommendations concerning subacute or chronic cough in Western primary care. Our study presents epidemiological data under non non-pandemic conditions. It will be interesting to compare these data to future research results of the post-pandemic era.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-021-01501-0.

Characterization of vacuum and deep ultraviolet pulses via two-photon autocorrelation signals

Characterization of ultrashort vacuum and deep ultraviolet pulses is important in view of applications of those pulses for spectroscopic and dynamical imaging of atoms, molecules, and materials. We present an extension of the autocorrelation technique, applied for measurement of the pulse duration via a single Gaussian function. Analytic solutions for two-photon ionization of atoms by Gaussian pulses are used along with an expansion of the pulse to be characterized using multiple Gaussians at multi-color central frequencies. This approach allows one to use two-photon autocorrelation signals to characterize isolated ultrashort pulses and pulse trains, i.e., the time-dependent amplitude and phase variation of the electric field. The potential of the method is demonstrated using vacuum and deep ultraviolet pulses and pulse trains obtained from numerical simulations of macroscopic high harmonic spectra.

Tolerance and microbiological efficacy of cefepime or piperacillin/tazobactam in combination with vancomycin as empirical antimicrobial therapy of prosthetic joint infection: a propensity-matched cohort study

BACKGROUND

The use of piperacillin/tazobactam with vancomycin as empirical antimicrobial therapy (EAT) for prosthetic joint infection (PJI) has been associated with an increased risk of acute kidney injury (AKI), leading us to propose cefepime as an alternative since 2017 in our reference centre.

OBJECTIVES

To compare microbiological efficacy and tolerance of these two EAT strategies.

METHODS

All adult patients with PJI empirically treated with vancomycin+cefepime (n = 89) were enrolled in a prospective observational study and matched with vancomycin+piperacillin/tazobactam-treated historical controls (n = 89) according to a propensity score including age, baseline renal function and concomitant use of other nephrotoxic agents. The two groups were compared using Kaplan-Meier curve analysis, and non-parametric tests regarding the proportion of efficacious empirical regimen and the incidence of empirical therapy-related adverse events (AE).

RESULTS

Among 146 (82.0%) documented infections, the EAT was considered efficacious in 77 (98.7%) and 65 (98.5%) of the piperacillin/tazobactam- and cefepime-treated patients, respectively (P = 1.000). The rate of AE, particularly AKI, was significantly higher in the vancomycin+piperacillin/tazobactam group [n = 27 (30.3%) for all AE and 23 (25.8%) for AKI] compared with the vancomycin+cefepime [n = 13 (14.6%) and 6 (6.7%)] group (P = 0.019 and <0.001, respectively), leading to premature EAT discontinuation in 20 (22.5%) and 5 (5.6%) patients (P = 0.002). The two groups were not significantly different regarding their comorbidities, and AKI incidence was not related to vancomycin plasma overexposure.

CONCLUSIONS

Based on the susceptibility profile of bacterial isolates from included patients, microbiological efficacy of both strategies was expected to be similar, but vancomycin + cefepime was associated with a significantly lower incidence of AKI.

Attitudes of medical students to general practice: a multinational cross-sectional survey

BACKGROUND

A shortage of general practitioners (GPs) is common to many European countries. To counteract this, it is essential to understand the factors that encourage or discourage medical students from choosing to become a GP.

OBJECTIVE

To evaluate medical students' attitudes towards general practice and to identify factors that discourage them from considering a career as a GP.

METHODS

In this multinational cross-sectional online survey, 29 284 students from nine German, four Austrian and two Slovenian universities were invited to answer a questionnaire consisting of 146 closed and 13 open-ended items.

RESULTS

Of the 4486 students that responded (response rate: 15.3%), 3.6% wanted to become a GP, 48.1% were undecided and 34.6% did not want to be a GP. Significant predictors for interest in becoming a GP were higher age [odds ratio (OR) = 1.06; 95% confidence interval (CI) = 1.02-1.10], positive evaluation of the content of a GP's work (OR = 4.44; 95% CI = 3.26-6.06), organizational aspects (OR = 1.42; 95% CI = 1.13-1.78), practical experience of general practice (OR = 1.66; 95% CI = 1.08-2.56) and the country of the survey [Slovenian versus German students (Reference): OR = 2.19; 95% CI = 1.10-4.38; Austrian versus German students (Reference): OR = 0.50; 95% CI = 0.32-0.79].

CONCLUSION

Strategies to convince undecided students to opt for a career as a GP should include a positive representation of a GP's work and early and repeated experience of working in a general practice during medical school.

Implementation of a uniform nationwide medical licensing examination in general practice. A feasibility study

Objective: A competency-based training of medical students that is adapted to the realities of care is required internationally and is being intended in Germany with the Master Plan for Medical Studies 2020. In order to test these competencies, the German National Institute for state examinations in Medicine, Pharmacy and Psychotherapy (IMPP) has developed a concept for the redesign of the final part of the medical licensing examination in Germany. It focuses on general and interprofessional healthcare in the examination with outpatients. The aim of this work is to assess the feasibility of the new final examination on the basis of pilot examinations in family practices and to derive further steps for the national implementation. Methods: Fourteen medical students in their internship year completed a full examination with patients aged 42 to 84 years. Examiners evaluated the examination performance using standardised evaluation forms. Feasibility was qualitatively assessed in terms of compliance with content and time limits, examination results, patient reflections, and implementation in the practice. Results: Students were able to complete all tasks within the given time frame. Based on the evaluation forms, the examiners assessed the performance of the students. Patients appreciated the structured course of the examination in the familiar location of their family practice. For the nationwide implementation of the examination, 2,500 examination practices are required for about 10,000 examinees per year. Four students can then be examined on two days per year in each practice. Conclusions: Oral-practical examinations with outpatients in general medical practices can be carried out successfully throughout the nation. An implementation of the examinations throughout Germany requires that medical studies are restructured and that this new curriculum is implemented as intended by the Master Plan for Medical Studies 2020. Furthermore, training and remuneration of examiners together with a legal framework for the new examination must be established.

Coughing children in family practice and primary care: a systematic review of prevalence, aetiology and prognosis

BACKGROUND

For evidence-based decision making, primary care physicians need to have specific and reliable information on the pre-test probabilities of underlying diseases and a symptom's course. We performed a systematic review of symptom-evaluating studies in primary care, following three research questions: (1) What is the prevalence of the symptom cough in children consulting primary care physicians? (2) What are the underlying aetiologies of cough and the respective frequencies? (3) What is the prognosis of children with cough?

METHODS

Following a pre-defined algorithm and independent double reviewer ratings we searched MEDLINE and EMBASE. All quantitative original research articles in English, French or German were included if they focused on unselected study populations of children consulting a primary care physician for cough. We used the random effects model for meta-analysis in subgroups, if justifiable in terms of heterogeneity.

RESULTS

We identified 14 eligible studies on prevalence, five on aetiology and one on prognosis. Prevalence estimates varied between 4.7 and 23.3% of all reasons for an encounter, or up to estimates of 60% when related to patients or consultations. Cough in children is more frequent than in adults, with lowest prevalences in adolescents and in summer. Acute cough is mostly caused by upper respiratory tract infections (62.4%) and bronchitis (33.3%); subacute or chronic cough by recurrent respiratory tract infection (27.7%), asthma (up to 50.4% in cough persisting more than 3 weeks), and pertussis (37.2%). Potentially serious diseases like croup, pneumonia or tuberculosis are scarce. In children with subacute and chronic cough the total duration of cough ranged from 24 to 192 days. About 62.3% of children suffering from prolonged cough are still coughing two months after the beginning of symptoms.

CONCLUSION

Cough is one of the most frequent reasons for an encounter in primary care. Our findings fit in with current guideline recommendations supporting a thoughtful wait-and-see approach in acute cough and a special awareness in chronic cough of the possibility of asthma and pertussis. Further evidence of aetiological pre-test probabilities is needed to assess the diagnostic gain based on patient history and clinical signs for differential diagnoses of cough in children.

Transcriptome analysis of gynoecium morphogenesis uncovers the chronology of gene regulatory network activity

The gynoecium is the most complex organ formed by the flowering plants. It encloses the ovules, provides a surface for pollen contact and self-incompatibility reactions, allows pollen tube growth, and, post fertilization, develops into the fruit. Consequently, the regulation of gynoecium morphogenesis is complex and appropriate timing of this process in part determines reproductive success. However, little is known about the global control of gynoecium development, even though many regulatory genes have been characterized. Here, we characterized dynamic gene expression changes using laser-microdissected gynoecium tissue from four developmental stages in Arabidopsis. We provide a high-resolution map of global expression dynamics during gynoecium morphogenesis and link these to the gynoecium interactome. We reveal groups of genes acting together early and others acting late in morphogenesis. Clustering of co-expressed genes enables comparisons between the leaf, shoot apex, and gynoecium transcriptomes, allowing the dissection of common and distinct regulators. Furthermore, our results lead to the discovery of genes with putative transcription factor activity (B3LF1, -2, DOFLF1), which, when mutated, lead to impaired gynoecium expansion, illustrating that global transcriptome analyses reveal yet unknown developmental regulators. Our data show that genes encoding highly interacting proteins, such as SEPALLATA3, AGAMOUS, and TOPLESS, are expressed evenly during development but switch interactors over time, whereas stage-specific proteins tend to have fewer interactors. Our analysis connects specific transcriptional regulator activities, protein interactions, and underlying metabolic processes, contributing toward a dynamic network model for gynoecium development.

Transcriptome analysis reveals major transcriptional changes during regrowth after mowing of red clover (Trifolium pratense)

BACKGROUND

Red clover (Trifolium pratense) is globally used as a fodder plant due its high nutritional value and soil improving qualities. In response to mowing, red clover exhibits specific morphological traits to compensate the loss of biomass. The morphological reaction is well described, but the underlying molecular mechanisms and its role for plants grown in the field are unclear.

RESULTS

Here, we characterize the global transcriptional response to mowing of red clover by comparing plants grown under greenhouse conditions with plants growing on agriculturally used fields. Unexpectedly, we found that biotic and abiotic stress related changes of plants grown in the field overlay their regrowth related transcriptional changes and characterized transcription related protein families involved in these processes. Further, we can show that gibberellins, among other phytohormones, also contribute to the developmental processes related to regrowth after biomass-loss.

CONCLUSIONS

Our findings show that massive biomass loss triggers less transcriptional changes in field grown plants than their struggle with biotic and abiotic stresses and that gibberellins also play a role in the developmental program related to regrowth after mowing in red clover. Our results provide first insights into the physiological and developmental processes of mowing on red clover and may serve as a base for red clover yield improvement.

Microelimination or Not? The Changing Epidemiology of Human Immunodeficiency Virus-Hepatitis C Virus Coinfection in France 2012–2018

Background

The arrival of highly effective, well-tolerated, direct-acting antiviral agents (DAA) led to a dramatic decrease in hepatitis C virus (HCV) prevalence. Human immunodeficiency virus (HIV)-HCV–coinfected patients are deemed a priority population for HCV elimination, while a rise in recently acquired HCV infections in men who have sex with men (MSM) has been described. We describe the variations in HIV-HCV epidemiology in the French Dat’AIDS cohort.

Methods

This was a retrospective analysis of a prospective cohort of persons living with HIV (PLWH) from 2012 to 2018. We determined HCV prevalence, HCV incidence, proportion of viremic patients, treatment uptake, and mortality rate in the full cohort and by HIV risk factors.

Results

From 2012 to 2018, 50 861 PLWH with a known HCV status were followed up. During the period, HCV prevalence decreased from 15.4% to 13.5%. HCV prevalence among new HIV cases increased from 1.9% to 3.5% in MSM but remained stable in other groups. Recently acquired HCV incidence increased from 0.36/100 person-years to 1.25/100 person-years in MSM. The proportion of viremic patients decreased from 67.0% to 8.9%. MSM became the first group of viremic patients in 2018 (37.9%). Recently acquired hepatitis represented 59.2% of viremic MSM in 2018. DAA treatment uptake increased from 11.4% to 61.5%. More treatments were initiated in MSM in 2018 (41.2%) than in intravenous drug users (35.6%). In MSM, treatment at the acute phase represented 30.0% of treatments in 2018.

Conclusions

A major shift in HCV epidemiology was observed in PLWH in France from 2012 to 2018, leading to a unique situation in which the major group of HCV transmission in 2018 was MSM.

Clinical Trials Registration. NCT02898987.

Evaluation of different target genes for the detection of Salmonella sp. by loop-mediated isothermal amplification

The loop-mediated isothermal amplification (LAMP) technique was used to investigate six salmonella-specific sequences for their suitability to serve as targets for the pathogen identification. Sequences selected for designing LAMP primers were genes invA, bcfD, phoP, siiA, gene62181533 and a region within the ttrRSBCA locus. Primers including single nucleotide polymorphisms were configured as degenerate primers. Specificity of the designed primer sets was determined by means of 46 salmonella and 32 other food- and waterborne bacterial reference species and strains. Primers targeting the ttrRSBCA locus showed 100 % inclusivity of target and exclusivity of other test species and strains. Other primer sets revealed deficiencies, especially regarding Salmonella enterica subsp. II-IV and Salmonella bongori. Additionally, primers targeting the siiA gene failed to detect S. enterica subsp. enterica serotypes Newport and Stanley, whereas bcfD primers did not amplify DNA of S. enterica subsp. enterica serotype Schleissheim. TtrRSBCA primers, providing short detection times and constant melting temperatures of amplification products, achieved best overall performance.