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.

Abstract 1455: The glucocorticoid receptor-LEDGFp75 interaction in prostate cancer therapy cross-resistance

Prostate cancer (PCa) is the second leading cause of cancer deaths in the U.S., disproportionally affecting African American (AA) men. PCa patients with recurrent disease develop therapy resistance and fail to respond to both anti-androgen receptor signaling (ARSI) therapy and taxane-based chemotherapy. Glucocorticoid receptor, a transcription factor, has been implicated in resistance to ARSI (via the GR bypass), and docetaxel (DTX) therapies. However, the mechanisms underlying this GR-mediated therapy cross-resistance are poorly understood. Previously, we demonstrated that glucocorticoids, which are co-administered with current PCa therapies and activate GR signaling, upregulate the chemoresistance-associated transcription coactivator LEDGFp75 in PCa cells. We also identified consensus GR binding sites in the promoter region of the gene encoding LEDGFp75, suggesting it is a GR target gene. We hypothesized that GR transcriptionally upregulates LEDGFp75 and then interacts with this protein in the nucleus to promote DTX resistance in PCa cells. Genetic silencing of GR in a panel of DTX-sensitive and -resistant PCa cell lines decreased the expression of LEDGFp75 at both the protein and transcript levels, confirming its status as a candidate GR target gene. However, genetic silencing of LEDGFp75 had no effects on GR protein expression. Pharmacological inhibition of GR also decreased LEDGFp75 in DTX-sensitive cells. The effects of Exicorilant and Relacorilant (Corcept Therapeutics) were evaluated on LEDGFp75 protein expression levels. Immunoprecipitation and confocal microscopy studies revealed that GR and LEDGFp75 interact in the nucleus of PCa cells. Interestingly, upregulation of GR in enzalutamide resistant LNCaP cells correlated with LEDGFp75 upregulation, and GR silencing in these cells decreased this upregulation. These results suggested a possible role for GR and LEDGFp75 in PCa therapy cross-resistance. Further studies are underway to determine if co-targeting these two proteins genetically and pharmacologically attenuates both enzalutamide resistance and DTX resistance and other aggressive properties of PCa cells. In addition, RNAseq studies have been initiated to determine the degree of transcriptional overlap between GR and LEDGFp75 in chemoresistant PCa cells. Our goal is to link mechanistically the GR-LEDGFp75 transcriptional network to ARSI/taxane cross-resistance in PCa and target this network to attenuate therapy resistance.

Citation Format: Evelyn S. Sanchez-Hernandez, Pedro T. Ochoa, Greisha L. Ortiz-Hernandez, Shannalee Martinez, Carlos Casiano. The glucocorticoid receptor-LEDGFp75 interaction in prostate cancer therapy cross-resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1455.

Abstract 3675: Epigenetic variations associated with therapy resistance among prostate tumors from Puerto Rican men

Prostate cancer (PCa) is the leading cause of cancer-related death in Puerto Rican (PR) men, a population at higher risk of developing the disease than other Hispanic/Latino groups. But the relationship between this phenomenon and epigenetics, and how this relationship explains PCa racial and ethnic health disparities are controversial. The purpose of this study was to expand on the knowledge regarding epigenetic differences in terms of DNA methylation to enable risk stratification and treatment selection in this genetically admixed population. In addition, we aim to assess differential DNA methylation patterns associated with drug resistance in PCa in PR Hispanic/Latino men. Since epigenetic changes and modifications represent critical components of carcinogenesis and progression, we are expecting differential methylation levels between aggressive vs. indolent, and resistant vs. non-resistant cases. Prostate tumors from PR men were stratified based on Gleason score. Methylation levels were measured by Illumina Infinium Methylation EPIC BeadChip DNA methylation platform, and bioinformatic analyses. In parallel, DNA methylation profiles were also analyzed using genomic DNA from PCa cells selected for resistance to androgen depletion, enzalutamide resistance, or docetaxel resistance. We identified 1,225 differentially methylated genes in prostate tumors compared with normal adjacent tissues, and 141 differentially methylated genes between aggressive vs. indolent tumors. Additionally, 723 differentially methylated genes were found in therapy resistant cell lines compared to parental controls. Analysis of the methylated genes obtained from aggressive prostate tumors from Puerto Rican patients and therapy-resistant PCa cell lines revealed four overlapping methylated genes: RNF220, FAM65B, PRDM16, and DGKH. Further analysis of PCa cells resistant to androgen depletion, enzalutamide, or docetaxel demonstrated impaired cellular migration of resistant phenotypes upon DNA methyltransferase (DNMT) inhibition using 5-azacytidine or zebularine compared to parental cell lines. DNMT1 was associated with resistance in PCa cell lines, and future studies will include silencing of methyltransferases will evaluation of drug re-sensitization. These findings provide critical insight into the epigenetic landscape of aggressive prostate tumors among PR men and highlight several candidate methylation biomarkers for assessing risk in this population.

Citation Format: Carlos J. Diaz Osterman, Anders Berglund, Shannalee Martinez, Camila Luis, Julie Dutil, Jaime Matta, Jarline Encarnacion-Medina, Carmen Ortiz-Sanchéz, Liang Wang, Jasreman Dhillon, Youngchul Kim, Hyun Y. Park, Gilbert Ruiz-Deya, Kosj Yamoah, Jong Y. Park. Epigenetic variations associated with therapy resistance among prostate tumors from Puerto Rican men [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3675.

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

"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.

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.

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.

Abstract 4395: The cMYC-associated transcription factor JPO2 is upregulated in taxane resistant prostate cancer cells and interacts with the stress oncoprotein LEDGF/p75

Prostate Cancer (PCa) progression leads to an advanced stage called metastatic castration PCa (mCRPC), for which currently there is no cure in spite of advances in treatment with new generation androgen deprivation drugs and chemotherapy with taxanes such as docetaxel (DTX). Our group demonstrated previously that the stress oncoprotein Lens Epithelium Derived Growth Factor of 75 kD (LEDGF/p75) is upregulated in clinical prostate tumors and contributes to DTX-resistance in mCRPC cells. However, little is known about the molecular mechanisms by which LEDGF/p75 promotes taxane resistance. The C-terminus of LEDGF/p75 contains a domain called the Integrase Binding Domain (IBD), which in T cells is responsible for tethering the HIV-integrase complex to transcriptionally active chromatin. In cancer cells, the LEDGF/p75 IBD interacts with oncogenic transcription complexes, such as Menin-MLL and the cMYC binding protein JPO2, to promote cell survival. However, the relevance of these protein-protein interactions (PPIs) in PCa and chemoresistance has never been explored. This study is designed to characterize the interaction between LEDGF/p75 and JPO2 in the DTX-resistant mCRPC cell lines PC3-DR and DU145-DR, and determine if this interaction contributes to drug resistance. Also, we want to target this interaction with repurposed HIV-based small molecule inhibitors (SMI’s) of LEDGF/p75, which target the IBD, to abrogate this resistance. We demonstrated by immunoblotting a significant 2-fold co-upregulation of JPO2 and LEDGF/p75 in the DTX-resistant PCa cells. We also observed the nuclear co-localization of these proteins by immunofluorescence microscopy. Using an immunoprecipitation approach, we confirmed that endogenous JPO2 and LEDGF/p75 co-immunoprecipitate in the DTX-resistant PCa cells. In addition, we initiated studies to evaluate SMIs originally designed to target the interaction between LEDGF/p75 and HIV-IN, for their efficacy in sensitizing resistant cells to DTX. After screening over 100 candidate inhibitors, we selected a set of SMIs which demonstrated a 20-30% decrease in viability in DTX-resistant cells when used alone, and 40-60% when used in combination with DTX. Studies are in progress to determine if these SMIs bind to LEDGF/p75 and inhibit its interaction with JPO2 and other oncoproteins. We predict that targeting LEDGF/p75 PPIs with HVI-based SMIs will disrupt transcriptional activity contributing to DTX resistance. Our goals are to establish the contribution of PPIs to LEDGF/p75-mediated transactivation of stress oncoproteins, and target these interactions to overcome PCa chemoresistance.

Citation Format: Greisha L. Ortiz Hernandez, Shannalee Martinez, Evelyn Sanchez-Hernandez, Leslimar Rios-Colon, Christina Cajigas-DuRoss, Tino Sanchez, Nouri Neamati, Carlos A. Casiano. The cMYC-associated transcription factor JPO2 is upregulated in taxane resistant prostate cancer cells and interacts with the stress oncoprotein LEDGF/p75 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4395.

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.

[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.

[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.

Abstract 3295: A novel patient-derived xenograft model for evaluating the role of TSLP in CRLF2 B-ALL

B-cell acute lymphoblastic leukemia (B-ALL) with genetic alterations leading to overexpression of CRLF2 (CRLF2 B-ALL) is associated with poor outcomes. CRLF2 B-ALL is 5 times more common in Hispanic children than others making it a significant biological component of pediatric cancer health disparities. CRLF2 is a component of the receptor complex that is activated by the cytokine, TSLP. Receptor signaling induces Jak/STAT5 and PI3/AKT/mTOR pathway activation and plays a role in the proliferation and differentiation B cell precursors. We found that primary human bone marrow (BM) stroma express TSLP providing an in vivo source of TSLP to stimulate CRLF2 B-ALL cells. Our goal was to develop patient-derived xenograft (PDX) models of CRLF2 B-ALL for studies to understand disease mechanisms and identify therapies to treat CRLF2 B-ALL and reduce the health disparities for Hispanic children with this disease. PDX models are possible because many cytokines produced in the mouse show cross species activity on human cells. However, available data suggests that mouse TSLP does not activate human CRLF2-mediated signals. Using phospho flow cytometry we show that mouse TSLP was unable to induce increases in pSTAT5, pAKT and pS6 observed in CRLF2 B-ALL cells stimulated with human TSLP. We developed a human TSLP +/- PDX model system by transplanting immune deficient NSG mice with HS-27 stroma transduced to express human hTSLP (hTSLP+ mice) or with control vector (hTSLP- mice). Human TSLP was present at normal human serum levels in hTSLP+ mice but undetectable in hTSLP- mice. To identify genes targeted by TSLP in CRLF2 B-ALL and verify pathway activation, we transplanted primary leukemia cells from a Hispanic patient into hTSLP+ and hTSLP- mice. Whole genome microarray was performed on CRLF2 B-ALL cells isolated from the BM of the hTSLP+ and hTSLP- PDX mice. Microarray identified 280 genes that are upregulated and 281 genes that are downregulated in vivo in leukemia cells from hTSLP+ as compared to hTSLP- PDX mice. Evaluation of microarray data by Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis showed that genes downstream of mTOR pathway activation were upregulated in hTSLP+ as compared to hTSLP- mice, confirming hTSLP activity in the hTSLP+ PDX mice. Our next question was whether cells expanded in hTSLP+ vs. hTSLP- mice would exhibit changes in their ability to respond to TSLP. When we subjected PDX-expanded primary CRLF2 B-ALL cells to ex vivo TSLP stimulation ∼1/3 fewer gene targets were up- and downregulated in the leukemia cells expanded in hTSLP- mice as compared to cells from hTSLP+ mice. This suggests that CRLF2 B-ALL cells expanded in xenograft without TSLP lose some of their ability to respond to TSLP. The hTSLP+ CRLF2 B-ALL PDX mice described here provide a novel preclinical model for studying disease mechanisms and identifying therapies to target signaling pathways activated by TSLP in CRLF2 B-ALL and reduce cancer health disparities for this disease.

Citation Format: Olivia L. Francis, Parveen Shiraz, Terry-Ann Milford, Ineavely Baez, Jacqueline S. Coats, Karina Mayagoitia, Elizabeth Ginelli, Katherine R. Salcedo-Concepcion, Shannalee Martinez, Xiaobing Zhang, Valeri Filippov, Ruijun J. Su, Ross Fisher, Christopher L. Morris, Sinisa Dovat, Kimberly J. Payne. A novel patient-derived xenograft model for evaluating the role of TSLP in CRLF2 B-ALL. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3295. doi:10.1158/1538-7445.AM2015-3295

[Endobronchial ultrasound in the diagnosis of malignant pleural mesothelioma]

The diagnosis of malignant pleural mesothelioma relies mostly on the pathological examination of pleural samples, validated by a panel of experts and generally obtained during medical or surgical thoracoscopy performed for the management of an exudative pleural effusion. In the absence of pleural effusion (dry-type mesothelioma), the diagnostic approach depends on the features of the lesions (pleural thickness, nodules and/or masses) and their pleural location. Ultrasound and CT-guided needle aspiration represent recognized alternative diagnostic techniques in these situations. We present the case of a patient, presenting a dry-type mesothelioma, whose diagnosis was obtained by endobronchial ultrasound (EBUS)-guided needle aspiration of a pleural mediastinal mass and confirmed by a CT-guided needle aspiration of another pleural mass in close contact with the chest wall. The samples have been compared and show quantitative and qualitative similarities. EBUS represents a minimally invasive alternative diagnostic technique for dry-type mesothelioma, showing thickness of the mediastinal pleura in contact with a central airway or when thoracoscopy, which remains the "gold standard" diagnostic approach, is not feasible.

[Bilateral diaphragmatic paralysis due to Parsonage-Turner syndrome]

We report the case of a 49-years-old patient who presented to the accident and emergency department with sudden onset dyspnea associated with acute shoulder pain. He was breathless at rest with supine hypoxemia. He had an amyotrophic left shoulder with localized paresis of the shoulder. Both hemi-diaphragms were elevated on chest X-rays. Pulmonary function tests showed a restrictive pattern and both phrenic nerve conduction velocities were decreased. At night, alveolar hypoventilation was evidenced by elevated mean capnography (PtcCO2: 57mmHg). Neuralgic amyotrophy, Parsonage-Turner syndrome was the final diagnosis. This syndrome is a brachial plexus neuritis with a predilection for the suprascapular and axillary nerves. Phrenic nerve involvement is rare but where present can be the most prominent clinical feature as in our case report.

Abstract B21: A human-mouse xenograft model to evaluate therapies and study the role of TSLP-induced signals in Ph-like ALL

While the overall survival rate for children with B cell precursor acute lymphoblastic leukemia (B-ALL) is high, a subset of children with this disease are at high risk for relapse and death. Genome-wide analysis has shown that gene expression profiles in these high-risk B-ALLs is similar to that of Philadelphia chromosome–positive ALL and these are designated Ph-like ALL. Approximately half of Ph-like ALL are characterized by genetic defects resulting in overexpression of CRLF2. CRLF2, together with the IL-7Rα, forms a receptor complex that is activated by the cytokine, TSLP. The JAK-STAT5 pathway is phosphorylated downstream of this receptor complex activation. The activating JAK mutations found in some CRLF2 B-ALL have led to speculation that TSLP stimulation is not a factor in CRLF B-ALL. In preliminary studies to address this question we evaluated the effect of TSLP on a CRLF2 B-ALL cell lines with JAK defects and which have been reported to exhibit constitutive JAK-STAT5 activation. Our data show that TSLP increases STAT5 phosphorylation in these cell lines and also in primary CRLF2 B-ALL cells. Our next step was to evaluate the role of TSLP-CRLF2 interactions in vivo in the human-mouse xenograft model. However, mouse TSLP is different from most other cytokines produced in the xenograft in that it is species-specific and does not activate the human TSLP receptor complex that includes CRLF2. Thus, traditional xenograft models do not provide the TSLP-CRLF2 interactions that we believe to be a major factor in CRLF2 B-ALL. To overcome this obstacle we engineered immune-deficient NOD/SCID IL-2Rγ null (NSG) mice to express human TSLP (hTSLP+ mice) as well as control mice that lack the TSLP cytokine (hTSLP– mice). ELISA assays show serum hTSLP levels in the hTSLP+ mice that approximate the normal range in human serum. We used this hTSLP+/- xenograft model system to study the in vivo effects of TSLP on mice transplanted with Ph-like B-ALL. First, we used the hTSLP+/– xenograft model system to evaluate the in vivo effects of TSLP on survival and proliferation of transplanted CRLF2 B-ALL cells harboring a JAK defect (MUTZ5 cell line). Mice were euthanized at 5 weeks and BM was harvested. Evaluation of BM disease by flow cytometry showed that the percentage of viable human leukemia cells in hTSLP+ mice was twice that observed in hTSLP– mice. Evaluation of cell cycle progression in human CRLF2 B-ALL cells isolated from xenograft BM showed that the percentage of cycling cells in hTSLP+ mice was 2.5 fold higher than in hTSLP– mice. When primary Ph-like ALL cells were transplanted to produce hTSLP+/– xenografts, the viable pre-B ALL cells present in the BM of hTSLP+ mice showed higher expression levels of the TSLPR components (CRLF2 and IL-7Rα) than those in the hTSLP- mice. These data provide evidence that the TSLP produced in this model is active and that it impacts primary pre-B ALL cells. Preliminary data obtained from this model suggests that TSLP provides a signal that promotes in vivo survival of CRLF2 B-ALL cells and that it may play a role in selection of leukemia clones during in vivo leukemogenesis. Microarray analysis comparing gene expression in primary CRLF2 B-ALL cells isolated from hTSLP+ and hTSLP– xenograft mice identified 565 that genes are differentially regulated (&gt; 2 fold up or downregulated; p&lt;.05). Ingenuity Pathway Analysis is currently underway to identify the signaling pathways that are regulated by hTSLP in CRLF2 B-ALL in vivo in the hTSLP+/– xenograft model. The identification of genes downstream of TSLP-CRLF2 signaling has the potential of providing drug targets for combination therapy to effectively treat Ph-like B-ALL. The hTSLP+/– xenograft model will provide an important tool for evaluating the in vivo efficacy of these and other drugs to treat CRLF2 B-ALL.

Citation Format: Olivia Francis, Ruijun Su, Shannalee Martinez, Ineavely Baez, Terry-Ann Milford, Terrence Bennett, Ross Fisher, Christopher L. Morris, Sinisa Dovat, Kimberly J. Payne. A human-mouse xenograft model to evaluate therapies and study the role of TSLP-induced signals in Ph-like ALL. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr B21.

HPV-negative carcinoma of the uterine cervix: a distinct type of cervical cancer with poor prognosis

OBJECTIVE

Using highly sensitive polymerase chain reaction (PCR) techniques, we reanalysed all cervical carcinomas (CCs) found to be human papillomavirus (HPV)-negative by Hybrid Capture 2 (HC2) to determine the prevalence of true HPV-negativity. We also evaluated the characteristics of the patients with tumours with confirmed HPV-negativity.

DESIGN

Observational study.

SETTING

Barcelona, Spain.

POPULATION

A cohort of 136 women with CC (32 adenocarcinomas, 104 squamous cell carcinomas) who had pre-treatment HC2 testing.

METHODS

All negative cases were reanalysed and genotyped for HPV using three PCR assays (SPF10, GP5+/6+ and E7-specific assay).

MAIN OUTCOME MEASURES

Percentage of confirmed HPV-negative and HPV-positive tumours. Clinicopathological features and disease-free survival (DFS) and overall survival (OS) of both groups.

RESULTS

Fourteen of 136 women (10.2%) were negative for HPV by HC2. After reanalysis by PCR-based techniques only 8/136 (5.8%) tumours were confirmed as HPV-negative, whereas in six cases different HPVs were identified [HPV-11, -16 (two tumours), -18, -45, and -68]. Confirmed HPV-negativity was more frequent in adenocarcinomas than in squamous cell carcinomas (5/32, 15.6% versus 3/104, 2.9%, respectively; P = 0.017). Patients with CCs with confirmed HPV-negativity had significantly worse DFS than women with HPV-positive tumours [51.9 months (95% CI 12.2-91.7 months) versus 109.9 months (95% CI 98.2-121.5 months); P = 0.010]. In the multivariate analysis HPV-negativity and International Federation of Gynecology and Obstetrics (FIGO) staging were associated with increased risk of progression and mortality.

CONCLUSIONS

An HC2-negative result is an uncommon finding in women with CC, but in almost half of these cases HPVs are identified by more sensitive techniques. CCs with confirmed HPV-negativity are more frequently adenocarcinomas, and seem to be associated with worse DFS.