Learning curve of ultrasound-guided surgeon-administered transversus abdominis plane (UGSA-TAP) block on a porcine model

Background

Surgeons commonly perform ultrasound-guided Transversus Abdominis Plane blocks to manage acute pain following abdominal surgeries. There is no consensus on whether surgeons should undergo basic hands-on training to perform TAP blocks or if video-based learning is sufficient. We theorized that simulation-based learning is superior to video-based learning. In the present study, we present the analysis of technical skills of UGSA-TAP block performance on a live porcine model by general surgery trainees after undergoing video or simulation-based learning.

Methods

We performed a prospective, double-blinded, randomized study. Ten surgery residents and two surgery critical-care fellows (n = 12) without prior experience in performing the TAP block were recruited. The participants were randomized either into a video-based or simulation-based training group. After that, all participants performed a TAP block on a live anesthetized pig, which was recorded and scored by three blinded anesthesiologists. All participants completed a post-performance survey to assess their confidence in gaining competency in the UGSA-TAP block. Statistical analyses were performed to assess the differences between the two groups. P < 0.05 was considered statistically significant.

Results

All simulation-based learning participants successfully performed a survey scan, identified the three muscular layers of the abdominal wall, and identified the transversus abdominis plane compared to 50 %, 50 %, and 33 % video-based learning group participants for the respective parameters (p < 0.05). While some performance metrics showed no statistically significant differences between the groups, substantial effect sizes (Cohen's ℎ up to 1.07) highlighted notable differences in participants' performance. Both groups exhibited confidence in core competencies, with varied rates of satisfactory skill execution. Performance assessed using a global rating scale revealed a higher passing rate for the simulation group (83 % vs. 33 %). Participant feedback via the Likert scale reflected confidence post-training. Inter-rater reliability (0.83-1) confirmed the robustness of study evaluations.

Conclusion

The UGSA-TAP block curriculum should be introduced into the surgical residency programs with an emphasis on simulation-based learning to enhance the procedural skills of the trainees before transitioning to surgical patients.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Toward Precision Medicine in Atopic Dermatitis Using Molecular-Based Approaches

Atopic dermatitis is the most common chronic inflammatory skin disorder, affecting up to 20% of children and 10% of adults in developed countries. The pathophysiology of atopic dermatitis is complex and involves a strong genetic predisposition and T-cell driven inflammation. Although our understanding of the pathology and drivers of this disease has improved in recent years, there are still knowledge gaps in the immune pathways involved. Therefore, advances in new omics technologies in atopic dermatitis will play a key role in understanding the pathogenesis of this burden disease and could develop preventive strategies and personalized treatment strategies. In this review, we discuss the latest developments in genetics, transcriptomics, epigenomics, proteomics, and metagenomics and understand how integrating multiple omics datasets will identify potential biomarkers and uncover nets of associations between several molecular levels.

Toward Precision Medicine in Atopic Dermatitis Using Molecular-Based Approaches

Atopic dermatitis is the most common chronic inflammatory skin disorder, affecting up to 20% of children and 10% of adults in developed countries. The pathophysiology of atopic dermatitis is complex and involves a strong genetic predisposition and T-cell driven inflammation. Although our understanding of the pathology and drivers of this disease has improved in recent years, there are still knowledge gaps in the immune pathways involved. Therefore, advances in new omics technologies in atopic dermatitis will play a key role in understanding the pathogenesis of this burden disease and could develop preventive strategies and personalized treatment strategies. In this review, we discuss the latest developments in genetics, transcriptomics, epigenomics, proteomics, and metagenomics and understand how integrating multiple omics datasets will identify potential biomarkers and uncover nets of associations between several molecular levels.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

A genotype-specific architectural and physiological profile is involved in the flowering regularity of apple trees

In polycarpic plants, meristem fate varies within individuals in a given year. In perennials, the proportion of floral induction (FI) in meristems also varies between consecutive years and among genotypes of a given species. Previous studies have suggested that FI of meristems could be determined by the within-plant competition for carbohydrates and by hormone signaling as key components of the flowering pathway. At the genotypic level, variability in FI was also associated with variability in architectural traits. However, the part of genotype-dependent variability in FI that can be explained by either tree architecture or tree physiology is still not fully understood. This study aimed at deciphering the respective effect of architectural and physiological traits on FI variability within apple trees by comparing six genotypes with contrasted architectures. Shoot type demography as well as the flowering and fruit production patterns were followed over 6 years and characterized by different indexes. Architectural morphotypes were then defined based on architectural traits using a clustering approach. For two successive years, non-structural starch content in leaf, stem and meristems, and hormonal contents (gibberellins, cytokinins, auxin and abscisic acid) in meristems were quantified and correlated to FI within-tree proportions. Based on a multi-step regression analysis, cytokinins and gibberellins content in meristem, starch content in leaves and the proportion of long shoots in tree annual growth were shown to contribute to FI. Although the predictive linear model of FI was common to all genotypes, each of the explicative variables had a different weight in FI determination, depending on the genotype. Our results therefore suggest both a common determination model and a genotype-specific architectural and physiological profile linked to its flowering behavior.

CD9 mediates the uptake of extracellular vesicles from cancer-associated fibroblasts that promote pancreatic cancer cell aggressiveness

In pancreatic ductal adenocarcinoma (PDAC), signaling from stromal cells is implicated in metastatic progression. Tumor-stroma cross-talk is often mediated through extracellular vesicles (EVs). We previously reported that EVs derived from cancer-associated stromal fibroblasts (CAFs) that are abundant in annexin A6 (ANXA6⁺ EVs) support tumor cell aggressiveness in PDAC. Here, we found that the cell surface glycoprotein and tetraspanin CD9 is a key component of CAF-derived ANXA6⁺ EVs for mediating this cross-talk. CD9 was abundant on the surface of ANXA6⁺ CAFs isolated from patient PDAC samples and from various mouse models of PDAC. CD9 colocalized with CAF markers in the tumor stroma, and CD9 abundance correlated with tumor stage. Blocking CD9 impaired the uptake of ANXA6⁺ EVs into cultured PDAC cells. Signaling pathway arrays and further analyses revealed that the uptake of CD9⁺ANXA6⁺ EVs induced mitogen-activated protein kinase (MAPK) pathway activity, cell migration, and epithelial-to-mesenchymal transition (EMT). Blocking either CD9 or p38 MAPK signaling impaired CD9⁺ANXA6⁺ EV-induced cell migration and EMT in PDAC cells. Analysis of bioinformatic datasets indicated that CD9 abundance was an independent marker of poor prognosis in patients with PDAC. Our findings suggest that CD9-mediated stromal cell signaling promotes PDAC progression.

AB0275 TOFACITINIB EFFECTIVENESS IN PATIENTS WITH RHEUMATOID ARTHRITIS AFTER CONVENTIONAL OR BIOLOGICAL THERAPY - IT REAL ROLE IN DIFFERENT LINES OF TREATMENT

Background:

rheumatoid arthritis (RA) is a chronic and disabling autoimmune disease, with a high clinical and economic burden. This implies the need to investigate therapies that maximize clinical results. Tofacitinib is recommended as a different alternative to biologic therapy when a patient remains with moderate or high disease activity after conventional DMARDs use, or as an option after failure to biologic therapy.

Objectives:

to evaluate the effectiveness of Tofacitinib in RA as first-line (after conventional DMARDs failure) or second-line treatment (after biologic therapy failure) in a real-life cohort of RA patients and its differences.

Methods:

this is a descriptive retrospective cohort study conducted at a specialized center for RA in Bogota, Colombia; databases from 2017 to 2019 were used to select and study patients with indication of Tofacitinib, regardless of their previous treatment or disease status. The indication and initiation of Tofacitinib (5 mg BID or 11 mg once daily) was an independent medical decision made as part of the individualized management of every patient. Effectiveness was evaluated in those patients who met the high adherence criteria (at least three visits with a rheumatologist per year), with no change or addition of other conventional DMARDs. Frequencies and proportions in baseline characteristics, differences in disease activity were calculated between the first and second line tofacitinib treatment. Comparisons of continuous variables data between the two patient groups were made using the t-test; the chi-square test and Fisher’s exact test were used for statistical analysis of categorical variables. Logistic regressions were performed to analyze related factors with therapeutic response outcomes.

Results:

we included 152 RA patients who received tofacitinib: first-line (T1) (n= 85, 55.9%) or second-line (T2) (n= 67, 44.1%). T1 first-line group was younger than the T2 second-line patients (53±12.8 years and 59±11.4 years, p-value 0.01) and they had a shorter disease duration than T2 patients (11.8 vs. 12.8 years, p-value 0.01). Comparative analysis of response to treatment showed a reduction in DAS28 at 3, 6 and 12 months in both study groups. The response in disease activity at 3 months was a major factor related to 6-month response (OR 13.4, 95% CI 4.5-39.4, p value 0.000), while non-response at 3 months were associated with no response at 6 months of follow-up. Baseline DAS28 was significantly associated with response at 12 months (OR 1.9, 95% CI 1.11-3.25, p-value 0.028). At 12 months of treatment, both groups showed disease response and control according to the DAS28 from baseline, but a higher proportion of T1 patients achieved remission (45% vs 23%). A subgroup analysis to evaluate T2 second-line Tofacitinib therapy showed no statistically significant differences in any response criteria according to the number of previously received biologicals.

Table 1.

Regression analysis (risk of response of the disease at 6 and 12 months of treatment with Tofacitinib)

FactorResponse at Month 6Response at Month 12*ORIC95%P valueORIC95%P valueAge1.000.97-1.030.7881.020.98-1.060.211Male1.820.65-5.080.2510.810.27-2.380.709Duration of RA0.990.94-1.040.9081.020.96-1.080.444Positive Rheumatoid Factor0.81026-2.560.7300.630.17-2.260.485Positive Anti-CCP0.340.068-1.60.189Initial DAS281.611.04-2.490.0331.91.11-3.250.018First line0.440.19-1.010.0541.470.56-3.830.423Treatment period1.120.80-1.550.4921.10.75-1.610.607Dose: 11 mg.0.950.42-2.130.9040.750.258-1.90.565Response at Month 313.424.57-39.40.0002.320.87-6.180.091

*Positive Anti-CCP at month 12 was omitted because of collinearity

Conclusion:

Tofacitinib is an effective treatment option for patients with RA after conventional DMARDs and in patients after biologic therapy failure, but maybe is better used it as a T1 first-line of treatment. Further studies are required to determine the real role of tofacitinib in different lines of RA treatment.

Disclosure of Interests:

Wilberto Rivero: None declared, Linda Ibata: None declared, Susan Martinez: None declared, Adriana Rojas-Villarraga: None declared, Pedro Santos-Moreno Speakers bureau: Pedro Santos-Moreno has received fees for conferences from: Abbvie, Biopas-UCB, Bristol, Janssen, Pfizer, Sanofi., Consultant of: Pedro Santos-Moreno has received fees for counseling and advisory boards from: Abbvie, Abbott, Biopas-UCB, Bristol, Janssen, Pfizer, Roche, Sanofi., Grant/research support from: Pedro Santos-Moreno has received research grants from: Abbvie, Abbott, Biopas-UCB, Bristol, Janssen, Pfizer, Roche, Sanofi.

AB0242 CERTOLIZUMAB IN MONOTHERAPY AS EFFECTIVE THAN IN COMBINATION IN RHEUMATOID ARTHRITIS PATIENTS

Background:

Tumour necrosis factor-a (TNFa) inhibitors are one of the most used biological therapy for rheumatoid arthritis (RA) patients without response to conventional disease-modifying antirheumatic drugs (cDMARDs). There is scarce information about biological DMARDs (bDMARDs) effectiveness as monotherapy in real life.

Objectives:

To assess the effectiveness of Certolizumab pegol in real-life clinical practice in a cohort of patients with RA and previous failure to cDMARDs who received certolizumab as monotherapy, combined with Methotrexate (MTX), combined with leflunomide (LFN), or both MTX and LFN.

Methods:

A retrospective cohort study was conducted at a specialized center for RA management in Colombia. Patients treated with Certolizumab as monotherapy or in combination with MTX, or LFN, or both MTX plus LFN, (2012 – 2020) were included. The indication of certolizumab was a independent decision based on disease activity. Patients could be taking adjuvant medications for pain and/or corticosteroids. Certolizumab was administered 400 mg SC monthly after three induction doses at weeks 0, 2 y 4, as monotherapy or in combination with MTX (until 25 mg/week), LFN (20 mg/day) or both as a first-line treatment after failure with cDMARDs or as a second-line treatment after failure with one or more bDMARDs. Effectiveness was assessed at three, six, and twelve months according to the change in DAS28. Exploratory comparisons of numeric variable data between groups were done (ANOVA). Chi-square test and Fisher’s exact test were used for categorical variables. Multivariate analyses (logistic regressions) were performed to analyse factors related to the response at 6 and 12 months.

Results:

Of 181 enrolled patients, 24 received certolizumab as monotherapy, 62 combined with MTX, 47 in combination with LFN and 48 in combination with MTX and LFN. 55.2% of patients were first-line treatment, without significant differences between groups. Mean age of subjects included was 57.87 ± 12.33 with a mean age of around 60 years in patients treated with CERTO+MTX and CERTO+LFN (p=0,014). Women predominated in all groups (84% of the total) (p=0,275). The duration of arthritis on average was 8.27 ± 8.73 years, without significant differences between treatment groups (p=0,871). In terms of disease activity, 78.5% of patients were in moderate or high disease activity, according to DAS28, without significant differences between the groups (p=0,787). Differences in the number of biologicals and corticoid use were observed, patients in the combination groups had used in a higher proportion two or more biological (p=0,046) than in the monotherapy group and had used corticosteroids (p=0,042) more frequently. Overall, there were decreased disease activity, at 3 and 6 months with no significant differences between groups (p=0,08). At 12 months of treatment, there was a higher maintenance in mild activity/remission response in monotherapy group compared to the others (p=0,01). In the multivariate analysis, no differences were observed in the response at 6 and 12 months between the treatment groups. The response at three months was the only variable associated with the 6-month response (OR 5.46; CI 95% 2.08 – 14.32). The response at three months (OR 4.04; CI 95% 1.28-12.69) and positive anti-CCP (OR 3.83; CI 95% 1.11-13.21) were associated with 12-month response.

Conclusion:

These exploratory results show a clear trend of Certolizumab being effective as monotherapy in patients previously treated with cDMARDs and even after being treated with one bDMARD. Although results are not statistically different, it seems that certolizumab in monotherapy could be as least as effective as combination therapy. Prospective studies with larger sample size and with a structured follow-up are needed to confirm these findings.

Disclosure of Interests:

Paola Osorio: None declared, Laura Villarreal: None declared, Wilberto Rivero: None declared, Linda Ibata: None declared, Susan Martinez: None declared, Adriana Rojas-Villarraga: None declared, Pedro Santos-Moreno Speakers bureau: has received fees for conferences from: Abbvie, Abbott, Biopas-UCB, Bristol, Janssen, Pfizer, Roche, Sanofi, Consultant of: has received fees for counseling, advisory boards from: Abbvie, Abbott, Biopas-UCB, Bristol, Janssen, Pfizer, Roche, Sanofi, Grant/research support from: has received fees for research grants from: Abbvie, Abbott, Biopas-UCB, Bristol, Janssen, Pfizer, Roche, Sanofi

Spatial variability in carbon- and nitrogen-related traits in apple trees: the effects of the light environment and crop load

Photosynthetic carbon assimilation rates are highly dependent on environmental factors such as light availability and on metabolic limitations such as the demand for carbon by sink organs. The relative effects of light and sink demand on photosynthesis in perennial plants such as trees remain poorly characterized. The aim of the present study was therefore to characterize the relationships between light and fruit load on a range of leaf traits including photosynthesis, non-structural carbohydrate content, leaf structure, and nitrogen-related variables in fruiting ('ON') and non-fruiting ('OFF') 'Golden Delicious' apple trees. We show that crop status (at the tree scale) exerts a greater influence over leaf traits than the local light environment or the local fruit load. High rates of photosynthesis were observed in the ON trees. This was correlated with a high leaf nitrogen content. In contrast, little spatial variability in photosynthesis rates was observed in the OFF trees. The lack of variation in photosynthesis rates was associated with high leaf non-structural carbohydrate content at the tree level. Taken together, these results suggest that low carbon demand leads to feedback limitation on photosynthesis resulting in a low level of within-tree variability. These findings provide new insights into carbon and nitrogen allocations within trees, which are heavily dependent on carbon demand.

"Optimization of Surgical Resident Safety and Education During the COVID-19 Pandemic - Lessons Learned"

The COVID-19 pandemic has engendered rapid and significant changes in patient care. Within the realm of surgical training, the resultant reduction in clinical exposure and case volume jeopardizes the quality of surgical training. Thus, our general surgery residency program proceeded to develop a tailored approach to training that mitigates impact on resident surgical education and optimizes clinical exposure without compromising safety. Residents were engaged directly in planning efforts to craft a response to the pandemic. Following the elimination of elective cases, the in-house resident complement was effectively decreased to reduce unnecessary exposure, with a back-up pool to address unanticipated absences and needs. Personal protective equipment availability and supply, the greatest concern to residents, has remained adequate, while being utilized according to current guidelines. Interested residents were given the opportunity to work in designated COVID ICUs on a volunteer basis. With the decrease in operative volume and clinical duties, we shifted our educational focus to an intensive didactic schedule using a teleconferencing platform and targeted areas of weakness on prior in-service exams. We also highlighted critical COVID-19 literature in a weekly journal club to better understand this novel disease and its effect on surgical practice. The long-term impact of the COVID-19 pandemic on resident education remains to be seen. Success may be achieved with commitment to constant needs assessment in the changing landscape of healthcare with the goal of producing a skilled surgical workforce for public service.

Comparative ecotoxicity of single and binary mixtures exposures of cadmium and nickel on growth and biomarkers of Lemna gibba

The aim of the present study was to investigate the toxicity effects of cadmium-nickel (Cd-Ni) after single and mixtures exposures over the macrophyte Lemna gibba. Effects were assessed on growth, as frond number and fresh weight and biochemical parameters, such as total protein content and activity of antioxidant enzymes. Plants were exposed to single Cd and Ni in concentrations that ranged between 0.13-33 mg/L and 0.18 and 11.82 mg/L, respectively. For binary mixtures, individual metal IC50 values were used for selection of the evaluated concentrations. The experimental design consisted in three different ratios based on the concept of toxic units (TU), each ratio was evaluated by five different concentrations. Both single and mixture treatments were performed for 7 days following the conditions according to OECD (2006). Single and mixture exposures affected plant growth and the biomarkers of the antioxidant response. Growth parameters showed a differential sensitivity after individual metal exposures. Cd was more toxic for L. gibba plants when fresh weight was considered, but on the contrary, considering frond number, Ni was the most toxic metal. IC50-7d, based on growth rate calculated on frond number were 17.8 and 2.47 mg/L, and on fresh weight were 1.08 and 3.89 mg/L, for Cd and Ni respectively. LOEC values for Cd were obtained at 2.06 and 1.03 mg/L, for frond number and fresh weight, respectively; while for Ni, these values were 0.92 and 11.82 mg/L. The three evaluated ratios for binary mixtures resulted in a high toxicity considering the same response variables in single metal exposures. Ratio 1 (2/3 TU Cd-1/3 TU Ni) was the most toxic considering both frond number and fresh weight, showing percentage inhibition of growth rates of 96 and 90%, respectively for the highest concentration. A modification of the protein content was observed in single, but especially in the mixture treatments. The activity of catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APOX; EC 1.11.1.11) and guaiacol peroxidase (GPOX; EC 1.11.1.7) was also affected in single and mixtures assays. APOX and GPOX showed a higher increase of its activities respect the controls after mixture treatments than for single metal treatments. Such optimization of the antioxidant system could be one of the causes of the antagonistic toxicity observed in mixture exposures. Concentration addition (CA) reference model, based on frond number, in Cd-Ni mixtures was not a good predictor to evaluate toxicity from dissolved metal concentration since the results showed that toxicity was less than additive, with an average of ΣTU = 2.17. The observed antagonisms resulted to be stronger in mixtures with higher metal concentrations.

Photodynamic therapy (PDT) in non-surgical treatment of periodontitis

Periodontitis represents a major problem for patients, since it is not possible to eliminate the bacteria that are responsible for this pathology with a pharmacological treatment. The present study included forty-four patients with periodontitis, who had undergone disinfection via photodynamic therapy (PDT) using a laser source having a 635 nm wavelength associated with a photoactivable substance (methylene blue). Clinical assessment of plaque index (PI), bleeding on probing (BOP), probing depth (PD), calculus index (CI), gingival recession (REC) and clinical attachment level (CAL) were recorded at base line, 1 month (4 weeks) after treatment and again 3 months (12 weeks) after treatment, while site radiography (RX) and microbiological test (MT) were recorded at base line and 3 months (12 weeks) after treatment. The outcomes show a good efficacy of the PDT in the elimination of the periodontal pathogenic microflora and in the improvement of the clinical parameters considered: from the base line to the final check after 12 weeks it has been observed a reduction in REC of about 16.9%, a reduction of CAL of about 17.85%, a reduction of the BoP of about 93.3%, a reduction of the PD of about 17%, a reduction of the CI of about 66.3%, a reduction of PI of about 44%, and microbiologically a reduction of the total amount of bacteria with proven parodontopathic properties (red complex bacteria) of about 58.74%. Within the limits of the present study, PDT can be reasonably considered as a good carrier that leads to significant improvements in the parameters (clinical and microbiological) considered.

Modelling transport of inhibiting and activating signals and their combined effects on floral induction: application to apple tree

Floral induction (FI) in shoot apical meristems (SAM) is assumed to be triggered by antagonistic endogenous signals. In fruit trees, FI occurs in some SAM only and is determined by activating and inhibiting signals originating from leaves and fruit, respectively. We developed a model (SigFlow) to quantify on 3D structures the combined impact of such signals and distances at which they act on SAM. Signal transport was simulated considering a signal 'attenuation' parameter, whereas SAM fate was determined by probability functions depending on signal quantities. Model behaviour was assessed on simple structures before being calibrated and validated on a unique experimental dataset of 3D digitized apple trees with contrasted crop loads and subjected to leaf and fruit removal at different scales of tree organization. Model parameter estimations and comparisons of two signal combination functions led us to formulate new assumptions on the mechanisms involved: (i) the activating signal could be transported at shorter distances than the inhibiting one (roughly 50 cm vs 1 m) (ii) both signals jointly act to determine FI with SAM being more sensitive to inhibiting signal than activating one. Finally, the genericity of the model is promising to further understand the physiological and architectural determinisms of FI in plants.

Comparative ecotoxicity of single and binary mixtures exposures of cadmium and zinc on growth and biomarkers of Lemna gibba

In the present study, single and mixture effects of cadmium (Cd) and zinc (Zn) on Lemna gibba were analyzed and compared using growth parameters, based on frond number and fresh weight, and biochemical parameters, such as pigment, protein content and activity of antioxidant enzymes. Plants were exposed for 7 days to these metals in nutrient solution. Single and mixture exposures affected plant growth and the biomarkers of the antioxidant response. Considering the growth parameters, Cd was found to be much more toxic than Zn. IC50-7d, based on growth rate calculated on frond number, were 17.8 and 76.73 mg/L, and on fresh weight were 1.08 and 76.93 mg/L, for Cd and Zn respectively. For Cd, LOEC values were obtained at 2.06 and 1.03 mg/L, for frond number and fresh weight respectively; while for Zn, at 20.1 and 74.6 mg/L. A high toxicity effect, considering the same response variables, was observed in plants exposed to the mixtures. Three fixed ratios, based on toxic units (TU) were assayed, ratio 1: 2/3 Cd-1/3 Zn, ratio 2: 1/2 Cd-1/2 Zn and ratio 3: 1/3 Cd-2/3 Zn. Ratio 3 (where Zn was added in higher proportion) was the less toxic. All concentrations of Ratio 1 and 2 significantly inhibited plant growth, showing a 100% inhibition of growth rate at the highest concentrations when based on frond number. Catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APOX; EC 1.11.1.11) and guaiacol peroxidase (GPOX; EC 1.11.1.7) activities in single metals assays were higher than controls. In mixture tests, the activity of APOX and GPOX was significantly stimulated in plants exposed to all evaluated combinations, while CAT was mainly stimulated in Ratio 3. It was observed that the activity of the enzymes was increased in the mixtures compared with similar concentrations evaluated individually. APOX activity was observed to fit the CA model and following a concentration-response pattern. The response of this antioxidant enzyme could serve as a sensitive stressor biomarker for Cd-Zn interactions. Frond number in Cd-Zn mixtures was not well predicted from dissolved metal concentration in solution using concentration addition (CA) as reference model, as results showed that toxicity was more than additive, with an average of ΣTU = 0.75. This synergistic effect was observed up to 50 mg Zn/L in the mixture, but when it was present in higher concentrations a less than additive effect was observed, indicating a protective effect of Zn. A synergistic and dose-ratio deviations from CA model were also observed.

0683 CPAP Adherence Relative To Sleep Duration And Sleep Period In Different Study Populations

Introduction

CPAP is intended for use during sleep to alleviate disordered breathing. Most patients who use CPAP do so for only a portion of their sleep period, although anecdotally it is known that some also use CPAP while awake. We compared the unusually high levels of CPAP adherence found in a recent study of patients with Overlap Syndrome to a VA clinical population and to participants from the APPLES study.

Methods

CPAP adherence levels were taken from three sources: (1) The O2VERLAP Study, a large comparative effectiveness trial that used two different methods of providing information and support to current CPAP users diagnosed with both OSA and COPD. (2) Combined data from the four most recent clinical CPAP trials conducted at VA San Diego Healthcare System. (3) The APPLES study. Total sample sizes were 332, 957, and 405, respectively. Total sleep time (TST) and total sleep period (TSP) were assessed via the Pittsburgh Sleep Quality Index (PSQI) for (1) and (2) and via polysomnography for (3).

Results

Mean CPAP use, TST, and TSP for each source were: (1) 6.7, 6.8, & 8.1; (2) 4.0, 6.1, & 7.5; (3) 4.5, 6.6, & 8.0. We examined the ratios of adherence over either TST or TSP, and the ratios for each source were: (1) 98% & 83%; (2) 66% & 55%; (3) 68% & 56%.

Conclusion

This comparison demonstrates that unlike many CPAP users who tend to use therapy for only a fraction of time spent asleep, patients with COPD and OSA exhibit higher levels of adherence which often exceed sleep time and may be obtaining additional benefits from CPAP use during non-sleep periods. More research is needed both to improve CPAP delivery and support for patients who are using CPAP sub optimally and to understand the factors that account for the heightened levels of CPAP adherence in COPD.

Support

PPRND #1507-31666; IIR 02-275; IIR 07-163; IIR 12-069; PULM-028-12F.

0995 Nightcap For School-nights: Association Between Milk Intake And Sleep Duration In First-graders

Introduction

Insufficient sleep has been identified as an obesity risk factor due to mechanistic pathways contributing to higher carbohydrate intake, including in children. Dietary intake of macronutrients, such as fats and protein found in milk, may serve as a modifiable risk factor for adequate sleep. We hypothesize that milk intake among a sample of urban first-graders may be associated with sleep duration.

Methods

Cross-sectional analysis of parent reports of an adapted version of the Child Sleep Health Questionnaire (CSHQ) and Block Dietary Data Systems Food Frequency Questionnaire (FFQ) were analyzed among a sample of 837 Black children in Brooklyn, New York. Summary scores were created for milk type. Milk intake was classified by fat content: whole milk and 2% categorized as high-fat, and 1% and skim as low-fat. Independent t-test, correlations and regression analysis to identify associations between parent reports of child’s sleep duration and milk intake were conducted.

Results

On average, children were 7.3 + 0.6 years old and 52% female. Nearly 57% of parents were immigrants. Children’s mean BMI was 17.27, approximately at the 85th BMI percentile according to CDC index-for-age percentiles. On average, FFQ data reported children consumed high-fat milk 6 days a week. Linear variable regression analysis between high-fat milk intake and sufficient sleep were significant (β =, 0.090, p &lt; 0.05). BMI was significantly associated with high-fat milk intake (β= 0.17, p&lt;0.05). However, high-fat milk intake was not significantly associated with (in)sufficient sleep, after controlling for BMI, sex and age. No difference was reported between immigrant parents and U.S. born parents.

Conclusion

Plausibly, high-fat milk is contributing to satiety and longer sleep duration. Future studies should include more comprehensive measurement of milk consumption (i.e. time of day and volume) to consider possible effects on children’s sleep. Actigraphy measures and sleep diaries should also be considered.

Support

Bezos Grant and Community Service Plan grant.

0238 Campus Food Pantry Assistance is Related to Better Physical And Mental Health Through Adequate Sleep Among College Students in a Public University System

Introduction

Food insecurity is an issue among students in higher education and has been linked to insufficient sleep, and poor mental and general health. College campuses have quickly responded by establishing campus food pantries. However, the extent to which campus food pantries are ameliorating the impacts of food insecurity is unknown.

Methods

Online survey data were collected from a cross-sectional sample of 1,855 students who were food pantry users in the 10-campus UC system. Students were asked to report their number of visits to a food pantry in the past month, and to rate their general health, depressive symptoms, and number of days of enough sleep (in a week) before and after food pantry access. Changes in days of enough sleep, depressive symptoms and general health were computed. Demographic characteristics were obtained from institutional data. Path analysis was used to examine direct and indirect pathways from food pantry use to depressive symptoms and general health through enough sleep days, controlling for workstudy receipt, Pell grant receipt and family income.

Results

Students on average were 21.7 years old (SD= 3.5), and had more days of adequate sleep (25%), and improved depressive symptoms (43%) and general health (31%) after obtaining services from a campus food pantry. An increase in monthly food pantry use was directly related to a decrease in depressive symptoms (β= 0.08, p&lt;0.001) and an increase in general health (β= 0.07, p=0.001). Additionally, an increase in food pantry use related to an increase in getting more days of enough sleep (β=0.07, p=0.001), which in turn positively related to a decrease in depressive symptoms (β=0.18, p&lt;0.001) and improved general health (β=0.24, p&lt;0.001).

Conclusion

Food pantry use had a positive relationship with student health outcomes, and enough sleep days played an important mediating role. Findings suggest that emergency food access may have a positive impact on student health outcomes.

Support

This study was funded by the UC Campus Basic Needs Committees.

0696 The O2VERLAP Study: High Cpap Use Levels Found In Overlap Syndrome (OSA And COPD) Patients

Introduction

CPAP therapy is prescribed to help manage disordered breathing during sleep time periods. Most users, especially those with non-severe obstructive sleep apnea (OSA), use it only for some portion of their sleep period. Patients with Overlap Syndrome have both OSA and chronic obstructive pulmonary disease (COPD). While there has been some research on CPAP use levels in this patient population, there has been little indication that they use CPAP any differently than those with OSA only.

Methods

The O2VERLAP Study was a large comparative effectiveness trial enrolling people with COPD and OSA and using two different methods of providing information and support to current users of CPAP therapy. The study utilized an electronic national recruitment strategy and 332 participants were enrolled. CPAP data from the 12-week study period was analyzed. The Pittsburgh Sleep Quality Index was used to determine both estimated total sleep period (TSP) and total sleep time (TST). Because participants were all current users of CPAP, data from the total sample was combined and used. The percentage of TST and TSP that CPAP was used was calculated as CPAP use divided by either TST or TSP.

Results

The mean TST was 6.8 hours, TSP was 8.1 hours, and CPAP use was 6.7 hours. CPAP was used during 98.5% of the TST and during 82.7% of the TSP. Over 35% of the sample used CPAP at a level that was equal to or greater than their total sleep period.

Conclusion

Most OSA study populations use CPAP for some fraction of their night’s sleep. This COPD/OSA study population used CPAP to a markedly high level, including over one-third of the sample (n=~100) who used CPAP more than their self-reported sleep period. Further research on the extent and reasons for non-sleep period (i.e., daytime) CPAP use in COPD patients is warranted.

Support

PPRND #1507-31666.

Combustion Method for Determination of Crude Protein in Meat and Meat Products: Collaborative Study

Twelve laboratories participated in a collaborative study to compare a combustion method with the AOAC mercury catalyst Kjeldahl method (928.08) for the determination of crude protein in meat and meat products. Three different combustion instruments were used; consequently, the combustion method for this study is written in generic terms describing the principle, the apparatus specifications, and the performance requirements needed. Fifteen sample pairs were used for the study; each pair consisted of the same commercial meat product from each of 2 different manufacturers. Protein content of all samples ranged from about 10 to 20%. In addition, nicotinic acid and lysine monohydrochloride were used as standards to assess combustion equipment performance. All laboratories and all instruments performed the combustion method satisfactorily on the basis of results for the standards. For the meat samples, repeatability standard deviations (sr) ranged from 0.11 to 0.40 for the Kjeldahl method and from 0.12 to 0.41 for the combustion method; the repeatability relative standard deviations (RSDr) ranged from 0.82 to 2.41% and from 0.60 to 2.23% for the Kjeldahl and combustion methods, respectively. Reproducibility standard deviations (SR) ranged from 0.20 to 0.49 for the Kjeldahl method and from 0.18 to 0.46 for the combustion method, whereas the reproducibility relative standard deviations (RSDR) ranged from 1.59 to 2.84% for the Kjeldahl method and from 1.32 to 3.35% for the combustion method. Overall grand means were 15.59% protein for the Kjeldahl method and 15.75% protein for the combustion method. The combustion method was adopted first action by AOAC International.

Impact of Within-Tree Organ Distances on Floral Induction and Fruit Growth in Apple Tree: Implication of Carbohydrate and Gibberellin Organ Contents

In plants, organs are inter-dependent for growth and development. Here, we aimed to investigate the distance at which interaction between organs operates and the relative contribution of within-tree variation in carbohydrate and hormonal contents on floral induction and fruit growth, in a fruit tree case study. Manipulations of leaf and fruit numbers were performed in two years on "Golden delicious" apple trees, at the shoot or branch scale or one side of Y-shape trees. For each treatment, floral induction proportion and mean fruit weight were recorded. Gibberellins content in shoot apical meristems, photosynthesis, and non-structural carbohydrate concentrations in organs were measured. Floral induction was promoted by leaf presence and fruit absence but was not associated with non-structural content in meristems. This suggests a combined action of promoting and inhibiting signals originating from leaves and fruit, and involving gibberellins. Nevertheless, these signals act at short distance only since leaf or fruit presence at long distances had no effect on floral induction. Conversely, fruit growth was affected by leaf presence even at long distances when sink demands were imbalanced within the tree, suggesting long distance transport of carbohydrates. We thus clarified the inter-dependence and distance effect among organs, therefore their degree of autonomy that appeared dependent on the process considered, floral induction or fruit growth.

Hypoxia-Induced Caveolin-1 Expression Promotes Migration and Invasion of Tumor Cells

BACKGROUND

Exacerbated proliferation of cancer cells in nascent tumors leads to the genesis of a hypoxic microenvironment, which is associated with poor patient prognosis, because these stress conditions enhance migratory, invasive and metastatic capacities of tumor cells. These changes are associated with the induction of the hypoxia-inducible factors (HIFs, mainly HIF1α) and increased expression of target genes, including Caveolin-1 (CAV1). Results from our group have shown that CAV1 expression in metastatic cancer cells promotes cell migration/invasion in vitro and metastasis in vivo in a manner dependent on tyrosine-14 phosphorylation by src family kinases. Here, we evaluated whether hypoxia-induced expression of CAV1 was required for hypoxia-dependent migration and invasion in cancer cells.

METHODS

B16-F10 murine melanoma and HT29(US) colon adenocarcinoma cells were exposed to hypoxia (1% O2). CAV1 expression was evaluated by western blotting. Endogenous CAV1 and HIF1α were knocked-down using different shRNA constructs. Cell migration and invasion were evaluated in Boyden Chamber and Matrigel assays, respectively.

RESULTS

We observed that hypoxia increased CAV1 protein levels in a HIF1 α- dependent manner, in B16-F10 and HT29(US) cells. Importantly, hypoxia-dependent migration of both tumor cell lines was blocked upon CAV1 knock-down. Likewise, pharmacological inhibition of HIF prevented hypoxia-induced migration and invasion in B16-F10 cells. Finally, hypoxia-induced migration was also blocked by the src-family kinase inhibitor 4-amino-5-(4-chloro-phenyl)-7-(t-butyl) pyrazolo3,4-dpyrimidine (PP2), an inhibitor of CAV1 phosphorylation.

CONCLUSION

Hypoxia induced migration and invasion of metastatic cancer cells require HIF1α-dependent induction of CAV1 expression and src family kinase activation.

Neoformation and summer arrest are common sources of tree plasticity in response to water stress of apple cultivars

BACKGROUND AND AIMS

Depending on the species, water stress affects different growth and developmental processes, mainly due to changes in hydraulic properties and hormonal signalling. This study compared the impact of water stress on tree development and organ growth in three apple cultivars.

METHODS

Trees were differentially irrigated to induce water stress or to provide well-watered conditions in their second and third years of growth. Effects of water stress were evaluated at tree scale by shoot number and proportions of the different types of shoots, and at shoot scale by metamer appearance rate, growth duration and arrest time, as well as organ size.

KEY RESULTS

Water stress promoted early growth cessation, prolonged summer arrests and decreased growth resumptions, thus modifying within-tree shoot demography in favour of short shoots. Growth cessations occurred in mild water stress conditions before any difference in stem water potential appeared. No major impact was observed on organ size. Consistently with tree ontogeny, the number of shoots that resumed growth after summer arrest decreased with years, but more in water-stressed than well-watered conditions.

CONCLUSIONS

Even though the impact of water stress differed slightly among cultivars, the reduction in neoformation and increase in summer arrest played a common role in apple tree morphological responses and led to stress avoidance by early reduction of tree leaf area.

Multi-scale high-throughput phenotyping of apple architectural and functional traits in orchard reveals genotypic variability under contrasted watering regimes

Despite previous reports on the genotypic variation of architectural and functional traits in fruit trees, phenotyping large populations in the field remains challenging. In this study, we used high-throughput phenotyping methods on an apple tree core-collection (1000 individuals) grown under contrasted watering regimes. First, architectural phenotyping was achieved using T-LiDAR scans for estimating convex and alpha hull volumes and the silhouette to total leaf area ratio (STAR). Second, a semi-empirical index (I PL) was computed from chlorophyll fluorescence measurements, as a proxy for leaf photosynthesis. Last, thermal infrared and multispectral airborne imaging was used for computing canopy temperature variations, water deficit, and vegetation indices. All traits estimated by these methods were compared to low-throughput in planta measurements. Vegetation indices and alpha hull volumes were significantly correlated with tree leaf area and trunk cross sectional area, while I PL values showed strong correlations with photosynthesis measurements collected on an independent leaf dataset. By contrast, correlations between stomatal conductance and canopy temperature estimated from airborne images were lower, emphasizing discrepancies across measurement scales. High heritability values were obtained for almost all the traits except leaf photosynthesis, likely due to large intra-tree variation. Genotypic means were used in a clustering procedure that defined six classes of architectural and functional combinations. Differences between groups showed several combinations between architectural and functional traits, suggesting independent genetic controls. This study demonstrates the feasibility and relevance of combining multi-scale high-throughput methods and paves the way to explore the genetic bases of architectural and functional variations in woody crops in field conditions.

Origin and composition of cell-free DNA in spent medium from human embryo culture during preimplantation development

STUDY QUESTION

What is the origin and composition of cell-free DNA in human embryo spent culture media?

SUMMARY ANSWER

Cell-free DNA from human embryo spent culture media represents a mix of maternal and embryonic DNA, and the mixture can be more complex for mosaic embryos.

WHAT IS KNOWN ALREADY

In 2016, ~300 000 human embryos were chromosomally and/or genetically analyzed using preimplantation genetic testing for aneuploidies (PGT-A) or monogenic disorders (PGT-M) before transfer into the uterus. While progress in genetic techniques has enabled analysis of the full karyotype in a single cell with high sensitivity and specificity, these approaches still require an embryo biopsy. Thus, non-invasive techniques are sought as an alternative.

STUDY DESIGN, SIZE, DURATION

This study was based on a total of 113 human embryos undergoing trophectoderm biopsy as part of PGT-A analysis. For each embryo, the spent culture media used between Day 3 and Day 5 of development were collected for cell-free DNA analysis. In addition to the 113 spent culture media samples, 28 media drops without embryo contact were cultured in parallel under the same conditions to use as controls. In total, 141 media samples were collected and divided into two groups: one for direct DNA quantification (53 spent culture media and 17 controls), the other for whole-genome amplification (60 spent culture media and 11 controls) and subsequent quantification. Some samples with amplified DNA (N = 56) were used for aneuploidy testing by next-generation sequencing; of those, 35 samples underwent single-nucleotide polymorphism (SNP) sequencing to detect maternal contamination. Finally, from the 35 spent culture media analyzed by SNP sequencing, 12 whole blastocysts were analyzed by fluorescence in situ hybridization (FISH) to determine the level of mosaicism in each embryo, as a possible origin for discordance between sample types.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Trophectoderm biopsies and culture media samples (20 μl) underwent whole-genome amplification, then libraries were generated and sequenced for an aneuploidy study. For SNP sequencing, triads including trophectoderm DNA, cell-free DNA, and follicular fluid DNA were analyzed. In total, 124 SNPs were included with 90 SNPs distributed among all autosomes and 34 SNPs located on chromosome Y. Finally, 12 whole blastocysts were fixed and individual cells were analyzed by FISH using telomeric/centromeric probes for the affected chromosomes.

MAIN RESULTS AND THE ROLE OF CHANCE

We found a higher quantity of cell-free DNA in spent culture media co-cultured with embryos versus control media samples (P ≤ 0.001). The presence of cell-free DNA in the spent culture media enabled a chromosomal diagnosis, although results differed from those of trophectoderm biopsy analysis in most cases (67%). Discordant results were mainly attributable to a high percentage of maternal DNA in the spent culture media, with a median percentage of embryonic DNA estimated at 8%. Finally, from the discordant cases, 91.7% of whole blastocysts analyzed by FISH were mosaic and 75% of the analyzed chromosomes were concordant with the trophectoderm DNA diagnosis instead of the cell-free DNA result.

LIMITATIONS, REASONS FOR CAUTION

This study was limited by the sample size and the number of cells analyzed by FISH.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study to combine chromosomal analysis of cell-free DNA, SNP sequencing to identify maternal contamination, and whole-blastocyst analysis for detecting mosaicism. Our results provide a better understanding of the origin of cell-free DNA in spent culture media, offering an important step toward developing future non-invasive karyotyping that must rely on the specific identification of DNA released from human embryos.

STUDY FUNDING/ COMPETING INTEREST

This work was funded by Igenomix S.L. There are no competing interests.

Growth and carbon balance are differently regulated by tree and shoot fruiting contexts: an integrative study on apple genotypes with contrasted bearing patterns

In plants, carbon source-sink relationships are assumed to affect their reproductive effort. In fruit trees, carbon source-sink relationships are likely to be involved in their fruiting behavior. In apple, a large variability in fruiting behaviors exists, from regular to biennial, which has been related to the within-tree synchronization vs desynchronization of floral induction in buds. In this study, we analyzed if carbon assimilation, availability and fluxes as well as shoot growth differ in apple genotypes with contrasted behaviors. Another aim was to determine the scale of plant organization at which growth and carbon balance are regulated. The study was carried out on 16 genotypes belonging to three classes: (i) biennial, (ii) regular with a high production of floral buds every year and (iii) regular, displaying desynchronized bud fates in each year. Three shoot categories, vegetative and reproductive shoots with or without fruits, were included. This study shows that shoot growth and carbon balance are differentially regulated by tree and shoot fruiting contexts. Shoot growth was determined by the shoot fruiting context, or by the type of shoot itself, since vegetative shoots were always longer than reproductive shoots whatever the tree crop load. Leaf photosynthesis depended on the tree crop load only, irrespective of the shoot category or the genotypic class. Starch content was also strongly affected by the tree crop load with some adjustments of the carbon balance among shoots since starch content was lower, at least at some dates, in shoots with fruits compared with the shoots without fruits within the same trees. Finally, the genotypic differences in terms of shoot carbon balance partly matched with genotypic bearing patterns. Nevertheless, carbon content in buds and the role of gibberellins produced by seeds as well as the distances at which they could affect floral induction should be further analyzed.

[Neuroplasticity: synaptogenesis during normal development and its implication in intellectual disability]

Neuroplasticity is the biological capacity of the nervous system to modify its structure and functioning to adapt to both physiological and pathological variations in the environment. Its main physiological consequences are learning and memory, and its pathological outcome is neurological rehabilitation. The continuous change and initial fragility of the developing brain make the embryonic and foetal periods especially plastic (what is known as developmental neuroplasticity). The progressive reduction in plasticity, however, is never complete and the capacity to modify the brain circuits in response to new learning (adaptive neuroplasticity) or brain injuries (reactive neuroplasticity) remains throughout the individual's entire lifespan. The main neurobiological mechanism underlying neuroplasticity is the formation of synaptic contacts between neurons. Neurodevelopmental disorders are associated to functional anomalies of the brain, often derived from the lack of adaptive or reactive capacity of the brain to modify circuits that are malformed or damaged by genetic or environmental anomalies. They are traditionally associated with the appearance of intellectual disability and mental illnesses. This review deals with the development of the neuroplasticity of the brain and its neurobiological mechanisms. Some of the cellular and molecular processes involved in its normal development are also examined, together with the possible consequences deriving from alterations affecting them.

Synthesis of 4-aryl-1,2,3-triazolyl appended natural coumarin-related compounds with antiproliferative and radical scavenging activities and intracellular ROS production modification

Diverse natural coumarin-based compounds linked to aryl via a 1,2,3-triazole spacer with antiproliferative activity against K562 cells, radical scavenging activity and a decrease of ROS production were provided.

The impact of long-term water stress on tree architecture and production is related to changes in transitions between vegetative and reproductive growth in the 'Granny Smith' apple cultivar

Water stress (WS) generates a number of physiological and morphological responses in plants that depend on the intensity and duration of stress as well as the plant species and development stage. In perennial plants, WS may affect plant development through cumulative effects that modify plant functions, architecture and production over time. Plant architecture depends on the fate of the terminal and axillary buds that can give rise, in the particular case of apple, to reproductive or vegetative growth units (GUs) of different lengths. In this study, the impact of long-term WS (7 years) on the fate of terminal and axillary buds was investigated in relation to flowering occurrence and production pattern (biennial vs regular) in the 'Granny Smith' cultivar. It was observed that WS decreased the total number of GUs per branch, regardless of their type. Conversely, WS did not modify the timing of the two successive developmental phases characterized by the production of long and medium GUs and an alternation of floral GUs over time, respectively. The analysis of GU successions over time using a variable-order Markov chain that included both the effects of the predecessor and water treatment revealed that WS reduced the transition towards long and medium GUs and increased the transition toward floral, short and dead GUs. WS also slightly increased the proportion of axillary floral GUs. The higher relative frequency of floral GUs compared with vegetative ones reduced the tendency to biennial bearing under WS. The accelerated ontogenetic trend observed under WS suggests lower vegetative growth that could, in turn, be beneficial to floral induction and fruit set.

Cancer-associated fibroblast-derived annexin A6+ extracellular vesicles support pancreatic cancer aggressiveness

The intratumoral microenvironment, or stroma, is of major importance in the pathobiology of pancreatic ductal adenocarcinoma (PDA), and specific conditions in the stroma may promote increased cancer aggressiveness. We hypothesized that this heterogeneous and evolving compartment drastically influences tumor cell abilities, which in turn influences PDA aggressiveness through crosstalk that is mediated by extracellular vesicles (EVs). Here, we have analyzed the PDA proteomic stromal signature and identified a contribution of the annexin A6/LDL receptor-related protein 1/thrombospondin 1 (ANXA6/LRP1/TSP1) complex in tumor cell crosstalk. Formation of the ANXA6/LRP1/TSP1 complex was restricted to cancer-associated fibroblasts (CAFs) and required physiopathologic culture conditions that improved tumor cell survival and migration. Increased PDA aggressiveness was dependent on tumor cell-mediated uptake of CAF-derived ANXA6+ EVs carrying the ANXA6/LRP1/TSP1 complex. Depletion of ANXA6 in CAFs impaired complex formation and subsequently impaired PDA and metastasis occurrence, while injection of CAF-derived ANXA6+ EVs enhanced tumorigenesis. We found that the presence of ANXA6+ EVs in serum was restricted to PDA patients and represents a potential biomarker for PDA grade. These findings suggest that CAF-tumor cell crosstalk supported by ANXA6+ EVs is predictive of PDA aggressiveness, highlighting a therapeutic target and potential biomarker for PDA.

Detecting QTLs and putative candidate genes involved in budbreak and flowering time in an apple multiparental population

In temperate trees, growth resumption in spring time results from chilling and heat requirements, and is an adaptive trait under global warming. Here, the genetic determinism of budbreak and flowering time was deciphered using five related full-sib apple families. Both traits were observed over 3 years and two sites and expressed in calendar and degree-days. Best linear unbiased predictors of genotypic effect or interaction with climatic year were extracted from mixed linear models and used for quantitative trait locus (QTL) mapping, performed with an integrated genetic map containing 6849 single nucleotide polymorphisms (SNPs), grouped into haplotypes, and with a Bayesian pedigree-based analysis. Four major regions, on linkage group (LG) 7, LG10, LG12, and LG9, the latter being the most stable across families, sites, and years, explained 5.6-21.3% of trait variance. Co-localizations for traits in calendar days or growing degree hours (GDH) suggested common genetic determinism for chilling and heating requirements. Homologs of two major flowering genes, AGL24 and FT, were predicted close to LG9 and LG12 QTLs, respectively, whereas Dormancy Associated MADs-box (DAM) genes were near additional QTLs on LG8 and LG15. This suggests that chilling perception mechanisms could be common among perennial and annual plants. Progenitors with favorable alleles depending on trait and LG were identified and could benefit new breeding strategies for apple adaptation to temperature increase.

[Brain development and plasticity]

Neurodevelopmental disorders are associated to functional anomalies of the brain that become manifest early on in life. Traditionally, they have been related almost exclusively to the appearance of intellectual disability and delayed psychomotor development. The causes of these disorders have been partially described, and include anomalies due to genetic causes (Down syndrome, fragile X syndrome, etc.), exposure to toxic factors during pregnancy (foetal alcohol syndrome), infections (cytomegalovirus, toxoplasmosis, etc.) or other alterations, including a status of great immaturity at birth (very preterm). Epidemiological data based on a better knowledge of the diseases affecting the central nervous system suggest that some mental disorders, which appear in adolescence or early adulthood, also have their origin in anomalies in brain development. This review aims to offer an overview of brain development. Some of the cellular and molecular processes that may account for the similarities and differences in the phenotypes that generate alterations affecting normal development are also analysed. The study is conducted with a view to clearly identifying processes that are susceptible to modification by means of therapeutic intervention consisting in an early care programme.

Genetic Variation of Morphological Traits and Transpiration in an Apple Core Collection under Well-Watered Conditions: Towards the Identification of Morphotypes with High Water Use Efficiency

Water use efficiency (WUE) is a quantitative measurement which improvement is a major issue in the context of global warming and restrictions in water availability for agriculture. In this study, we aimed at studying the variation and genetic control of WUE and the respective role of its components (plant biomass and transpiration) in a perennial fruit crop. We explored an INRA apple core collection grown in a phenotyping platform to screen one-year-old scions for their accumulated biomass, transpiration and WUE under optimal growing conditions. Plant biomass was decompose into morphological components related to either growth or organ expansion. For each trait, nine mixed models were evaluated to account for the genetic effect and spatial heterogeneity inside the platform. The Best Linear Unbiased Predictors of genetic values were estimated after model selection. Mean broad-sense heritabilities were calculated from variance estimates. Heritability values indicated that biomass (0.76) and WUE (0.73) were under genetic control. This genetic control was lower in plant transpiration with an heritability of 0.54. Across the collection, biomass accounted for 70% of the WUE variability. A Hierarchical Ascendant Classification of the core collection indicated the existence of six groups of genotypes with contrasting morphology and WUE. Differences between morphotypes were interpreted as resulting from differences in the main processes responsible for plant growth: cell division leading to the generation of new organs and cell elongation leading to organ dimension. Although further studies will be necessary on mature trees with more complex architecture and multiple sinks such as fruits, this study is a first step for improving apple plant material for the use of water.