New LC-MS/MS reference data for estradiol show mini-puberty in both sexes and typical pre-pubertal and pubertal patterns

CONTEXT

Reliable estradiol (E2) reference intervals (RIs) are crucial in Pediatric Endocrinology.

OBJECTIVES

To develop a sensitive ultra-performance liquid chromatographic tandem mass spectrometry (UPLC-MS/MS) method for E2 in serum, to establish graphically represented RI percentiles and annual RIs for both sexes and to perform a systematic literature comparison.

METHODS

First, an UPLC-MS/MS method for E2 was developed. Second, graphically represented RI percentiles and annual RIs covering 0-18 years were computed (cohort of healthy children (1181 girls, 543 boys)). Subsequently, RIs were compared with published data by systematic searches.

RESULTS

Lower limit of quantification was 11 pmol/L, indicating high sensitivity. E2 first peaked during mini-puberty in both sexes (girls up to 192 pmol/L; boys up to: 225 pmol/L). As could be expected, girls showed higher pubertal E2 (up to 638 pmol/L). However, boys' RIs (up to 259 pmol/L) overlapped considerably. We found four studies in the literature which also used LC-MS/MS to determine E2 and published RIs for the complete pediatric age range. RIs varied considerably. Pre-pubertal and pubertal phases were present in all studies. Higher E2 during the time of mini-puberty in both sexes was documented in three studies including ours.

CONCLUSIONS

Variability of RIs for E2 between studies illustrates importance of laboratory-specific RIs despite using a liquid chromatographic tandem mass spectrometry (LC-MS/MS) reference method. In boys, the striking E2 peak during mini-puberty as well as high pubertal E2 without phenotypic estrogenization in regular male puberty indicate that the role of E2 in children, and especially in boys requires better functional understanding.

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.

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.

Implantable cardioverter-defibrillator therapy in the very young - Patient characteristics procedural outcome and one-year follow-up - A subgroup analysis of the german DEVICE registry

Funding Acknowledgements

Type of funding sources: None.

Background

The implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy defibrillator (CRT-D) are well-established and essential therapeutic pillars for patients with heart failure and survivors of sudden cardiac death. The number of young patients receiving ICD or CRT-D has been increasing in the last decades. Understanding the key differences between the typically older ICD population and younger patients is paramount to optimized patient care.

Methods

The DEVICE registry prospectively enrolled patients undergoing ICD/CRT implantation or revision from 50 German centers between 2007–2014. Data on patient characteristics, procedural outcome, adverse events and mortality during the initial stay and follow-up was collected. All patients under the age of 45 years were identified and included into a comparative analysis with the remaining population.

Results

A total number of 4181 patients were enrolled into the registry, of which 236 patients (5.6%) were under the age of 45 years. Median age was 38.0 [31.0; 42.0] vs. 69.0 [60.0; 75.0] years, p&lt;0.001), compared to older patients. Young patients were more likely to receive an ICD (91.5 vs. 69.4%, p&lt;0.001), than CRT device and were less likely to suffer from non-cardiac comorbidities (20.3 vs. 67.4%, p&lt;0.001). Coronary artery disease was less common in young patients (15.7 vs. 63.6%, p&lt;0.001), whereas hypertrophic cardiomyopathy (11.0 vs. 2.5%, p&lt;0.001) and primary cardiac electrical diseases (14.0 vs. 1.6%, p&lt; 0.001) were encountered more often. Mean left-ventricular ejection fractions were 42.4±18.5 vs. 31.5±11.8%, respectively (p&lt;0.001) with less young patients in NYHA functional class III/IV (19.5 vs. 45.3%, p&lt;0.001). Primary symptom at presentation was chronic heart failure for older patients (19.5 vs. 34.8%, p&lt;0.001) and survived sudden cardiac death (30.9 vs. 15.6%, p&lt;0.001) for young patients. Thus, ICD for secondary prevention was more common in young patients (53.8 vs. 43.2%, p&lt;0.001). There were no detectable differences in postoperative complications (3.0 vs. 4.1%, p=0.500) or in-hospital mortality (0.0 vs. 0.3%, p=1.000). Median follow-up time was 514 [398; 669] vs. 458 [391; 563] days (p=0.006). Device-associated complications requiring revision were more common in young patients (16.3 vs. 8.2%, p&lt;0.001) and all-cause 1-year-mortality after implantation was lower (3.1 vs. 7.3%, p=0.029; HR 0.42, 95%CI: 0.19-0.94). Even though there was no difference in rates of rehospitalization between groups (32.1 vs. 32.4%, p=0.93), young patients were re-admitted more often for "cardiac" reasons (82.7 vs. 58.9%, p&lt;0.001).

Conclusion

Rates for procedural complications and in-hospital mortality were very low and without differences between both age groups. However younger patients experienced a higher rate of postoperative complications requiring revision and had higher readmission rates for cardiac reasons, potentially due to a more active lifestyle.

Impact of diabetes mellitus on long-term survival after transcatheter mitral valve edge-to-edge repair

Introduction

Diabetes mellitus (DM) represents a notable risk factor after surgical and interventional procedures but data on the influence of DM on long-term survival after Transcatheter Edge-to-edge Repair (TEER) for Mitral valve Regurgitation (MR) are sparse.

Purpose

To compare the outcome of patients with and without DM after TEER.

Methods

Retrospective monocentric assessment of patients after successful treatment of MR by TEER (exclusion of combined forms of transcatheter repair) between 06/2010 and 03/2018. Patients were stratified for DM at baseline and observed regarding mortality during follow-up. Cox regression analyses were performed for survival analyses.

Results

627 patients (47.0% females, 88.2% aged ≥70 years) and among these 174 subjects with DM (27.3%) were included with a median follow-up period of 486 days [IQR 157–916 days]). Within the investigation period, 20 patients (3.2%) were lost to follow-up. Patients with DM more often presented severe comorbidities like obesity (27.3% vs. 9.2%, p&lt;0.001), arterial hypertension (91.4% vs. 83.7%, p=0.013), renal insufficiency (63.8% vs. 43.9%, p&lt;0.001), coronary artery disease (77.0% vs. 59.8%, p&lt;0.001) or peripheral artery disease (14.4% vs. 8.4%, p=0.026) and had a higher median logistic Euroscore I (29.4% [20.0/43.0] vs. 25.0% [16.7/36.6], p=0.001) as well as reduced systolic function (LVEF 35% [30/50] vs. 45% [30/55], p&lt;0.001). No statistical differences in short- and long-term survival were detected between patients with and without DM (in-hospital mortality 1.7 vs. 2.6%, p=0.771; at 30-days 5.0 vs. 6.0%, p=0.842, 1-year 28.7 vs. 25.0%, p=0.419, 3-years 49.2 vs. 44.1%, p=0.554, 5-years 69.0 vs. 68.3%, p=0.497). By calculating cox regression analyses, DM was not predictive for a higher mortality, even after adjustment for other risk factors (HR 1-year 1.17 [95% CI 0.80–1.71], p=0.419; HR long-term 1.13 [95% CI 0.86–1.49], p=0.373) in the total cohort, as well as after stratification for the underlying mitral valve pathology (functional MR: 1-year HR 0.99 [95% CI 0.01–1.62], p=0.969, long-term HR 0.903 [95% CI 0.63–1.29, p=0.571; primary MR: 1-year HR 1.48 [95% CI 0.66–3.35, p=0.344, long-term HR1.66 [95% CI 0.89–3.09], p=0.110).

Conclusions

Even though DM-patients presented with a more vulnerable clinical profile, no relevant differences in short- and long-term mortality after TEER for MR were found. Although being factored in most common risk scores, DM could not be associated with an adverse prognosis after transcatheter therapy of MR.

Funding Acknowledgement

Type of funding sources: None.

P04.17 Antigen heterogeneity in glioblastoma cell lines, patient-derived cells, and patients’ glioblastoma tissue is an obstacle for CAR-T cell therapy development

BACKGROUND

Immunotherapy targeting surface antigens, e.g. CAR-T-cell therapy has become a promising therapeutic approach for glioblastoma (GBM) treatment. Antigen heterogeneity constitutes a major obstacle not only for preclinical in vitro studies but also for clinical translation. Here, we provide information about the surface expression of the eight in GBM CAR-T-cell therapy most targeted antigens (GD2, CSPG4, CD133, CD70, HER2, Il13Rα2, EGFRvIII and EphA2) by analyzing GBM cell lines (GCL), patient-derived cells (PDCL) and patients’ tumor tissue (PT) and comparing the expression profiles.

MATERIAL AND METHODS

We measured expression of the above-mentioned antigens in 7 GCL (GaMG, U87, U373, U343, U251, U138, DKMG), 7 PDCL and PT of 9 patients by flow cytometry (FACSCanto II). After evaluation with FlowJo software (TreeStar), we scored antigen expression (0–1.0: low expression, 1.1–2.0: medium expression, 2.1–3.0: high expression) and calculated the mean expression and range.

RESULTS

GD2 showed a medium expression in GCL (x̅=1.3) but was highly expressed in PDCL (x̅=2.6) and PT (x̅=2.4). In contrast, CSPG4 displayed low expression in GCL (x̅=0.3) and PT (x̅=0.4), but medium expression in PDCL (x̅=1.9). CD133, a stem cell marker, showed low expression in GCL (x̅=0.8) and PDCL (x̅=0.4), whereas the expression in PT was medium (x̅=1.4). Both CD70 and Il13Rα2 were weakly expressed in GCL, PDCL and PT (x̅=0.2, 0.4, 0.0 and 0.5, 0.6, 0.4, respectively). HER2 displayed medium expression in GCL (x̅=1.4) and PDCL (x̅=1.4) and low expression in PT (x̅=0.6). For EGFRvIII medium expression was detectable in all three entities (x̅=1.4, 1.1 and 1.1). EphA2 was mildly expressed in GCL (x̅=0.1), medium expressed in PT (x̅=2.0) and highly expressed in PDCL (x̅=2.6). Overall, there was high variability of antigen surface expression even within each of the groups.

CONCLUSION

GCL, PDCL and PT display heterogenic antigen surface expression with high variability within each group, thereby complicating clinical translation of in vitro results obtained using cell lines. This aspect should be taken into account in GBM target antigen research.

Cardiac Phenotype and Tissue Sodium Content in Adolescents With Defects in the Melanocortin System

CONTEXT

Pro-opiomelanocortin (POMC) and the melanocortin-4 receptor (MC4R) play a pivotal role in the leptin-melanocortin pathway. Mutations in these genes lead to monogenic types of obesity due to severe hyperphagia. In addition to dietary-induced obesity, a cardiac phenotype without hypertrophy has been identified in MC4R knockout mice.

OBJECTIVE

We aimed to characterize cardiac morphology and function as well as tissue Na+ content in humans with mutations in POMC and MC4R genes.

METHODS

A cohort of 42 patients (5 patients with bi-allelic POMC mutations, 6 heterozygous MC4R mutation carriers, 19 obese controls without known monogenic cause, and 12 normal weight controls) underwent cardiac magnetic resonance (CMR) imaging and 23Na-MRI.

RESULTS

Monogenic obese patients with POMC or MC4R mutation respectively had a significantly lower left ventricular mass/body surface area (BSA) than nonmonogenic obese patients. Left ventricular end-diastolic volume/BSA was significantly lower in POMC- and MC4R-deficient patients than in nonmonogenic obese patients. Subcutaneous fat and skin Na+ content was significantly higher in POMC- and MC4R-deficient patients than in nonmonogenic obese patients. In these compartments, the water content was significantly higher in patients with POMC and MC4R mutation than in control groups.

CONCLUSION

Patients with POMC or MC4R mutations carriers had a lack of transition to hypertrophy, significantly lower cardiac muscle mass/BSA, and stored more Na+ within the subcutaneous fat tissue than nonmonogenic obese patients. The results point towards the role of the melanocortin pathway for cardiac function and tissue Na+ storage and the importance of including cardiologic assessments into the diagnostic work-up of these patients.

Long-term outcomes with new generation prostheses in patients undergoing transcatheter aortic valve implantation

Background

Transcatheter Aortic Valve Implantation (TAVI) is today the first option for older patients with aortic valve stenosis (AS) at intermediate or high risk for surgery. Constant development of bioprosthetic valves and delivery systems have reduced complications and improved outcomes over the years. The 3rd generation Edwards Sapien 3 Valve (S3) and the 2nd generation Medtronic Evolut R Valve (ER) are currently the most frequently used worldwide. There is a paucity of published data regarding long term outcomes in these new generation TAVI patients.

Methods and results

In our retrospective, single-center analysis we included patients with severe Aortic Stenosis who underwent transfemoral TAVI with a new generation prosthesis between 2014 and 2016. Peri- and postprocedural outcomes of these patients were analyzed according to the VARC-2 criteria.

The study population consisted of 359 patients (mean patient age 82±7 years, 47% male, mean EuroSCORE II 8.0±8). The S3 group included 215 patients, the ER group 144 patients. Median follow-up period was 3.8 years (IQR 3.3 to 4.4 years, maximum follow-up in living patients 5.1 years).

Device Success rates where equal in both groups (93.0% vs. 92.4%, p=0.812). We report a 30-day mortality of 2.8% in the S3 group, 2.1% in the ER group, respectively (p=0.674). There was no difference in stroke rate, conversion to open heart surgery, major vascular complications, life-threatening or disabling bleeding or myocardial infarction. Implantation of a new permanent pacemaker was lower in the S3 group (S3: 27.4% vs. ER: 44.5%, p=0.002). While prosthesis mean gradients where higher in the S3 group (12.0 mmHg vs. 8.2 mmHg, p&lt;0.001), there was a tendency to less paravalvular leaks (PVL ≥2: 1% vs. 3.6%, p=0.088).

All-Cause Mortality up to 5 years did not show a difference between both patient groups (mean survival S3 3.5 years, ER 3.3 years, p=0.895). Independent predictors of death where impaired left ventricular function (HR 1.61, p=0.007), chronic kidney injury (HR 1.55, p=0.032), peripheral artery disease (HR 2.10, p=0.003), malignant tumor (HR 2.40, p&lt;0.001) and periprocedural stroke (HR 3.95, p=0.007).

Discussion

We present a comparison of the new-generation aortic valve prostheses Edwards Sapien 3 and Medtronic Evolut R concerning long-term as well as periprocedural outcomes. The analyzed cohort consisted of patients at intermediate to high surgical risk. Yet, 30-day mortality was very low both in S3 and ER patients. Device success and periprocedural outcomes in both groups were comparable and are in line with previous studies using VARC-2 definitions.

Conclusion

New generation TAVI valves offer an excellent implant and outcome success rate compared to early transcatheter Aortic valve replacement. Long-term survival was independent of prostheses choice and mainly attributed to pre- and intraprocedural comorbidities and complications.

All-Cause Mortality (Kaplan-Meier)

Funding Acknowledgement

Type of funding source: None

Impact of tricuspid valve regurgitation severity and its secondary reduction on long-term survival after transcatheter mitral valve edge-to-edge repair

Background

Mitral valve regurgitation (MR) is a frequent heart valve disorder affecting 1–2% of the humans in the general population and over 10% of the individuals older than 75 years. While a symptomatic and prognostic benefit of transcatheter edge-to-edge repair for MR (TMVR) was reported, data regarding long-term outcome as well as influence of concomitant tricuspid regurgitation (TR) are sparse.

Purpose

We aimed to investigate the impact of periinterventional development of TR on survival of patients undergoing interventional edge-to-edge repair for MR in a large retrospective monocentric study.

Methods

We retrospectively analyzed survival of patients successfully treated with isolated edge-to-edge repair for MR from 06/2010–03/2018 (exclusion of combined forms of TMVR) in our center. Baseline, periprocedural as well as follow-up data were gathered. Concomitant TR was evaluated at baseline and after 30 days and categorized from grades 0 (no TR) to grade III (severe TR). We analyzed the influence of severe vs. non-severe TR on 30-day, 1-year and long-term survival.

Results

Overall, 627 consecutive patients (47.0% female, 57.4% functional MR) were enrolled. Median follow-up time was 462 days [IQR 142–945]. Survival status was available in 96.7%. Survival rates were 97.6% at discharge, 75.7% after 1, 54.5% after 3, 37.6% after 5 and 21.7% after 7 years.

TR at baseline (examination results were available in 92.3%) was categorized as severe TR in 25.6%, medium TR in 33.3%, mild TR in 35.1% and no TR in 6.0%. TR at 1 month (examination results were available in 81.1%) was severe in 16.7%, medium in 30.2%, mild in 45.6% and no TR was found in 7.4%; improvement by at least 1 TR-grade was documented in 33.6% of the patients.

While a severe (compared to non-severe) TR at baseline did not affect the 30-day mortality (7.4% vs. 5.2%, p=0.354), 1-year survival was substantially impaired in those patients (36.5% vs. 23.0%, p=0.012). Accordingly, severe TR was not associated with 30d-mortality (as evaluated by univariate Cox regression, p=0.340), but with 1-year survival (HR 1.78, 95% CI 1.19–2.65, p=0.005) and showed a trend towards impaired long-term survival (HR 1.30, 95% CI 0.96–1.76, p=0.089).

While residual severe TR at one month did not influence 1-year-mortality significantly (p=0.478), improvement of TR demonstrated a trend to better survival after the first year (86.9 vs. 81.0%, p=0.208) confirmed in the Cox regression analysis (HR 0.66, 95% CI 0.36–1.22, p=0.188).

Conclusions

In this large retrospective monocentric study with a long-term follow-up-period of &gt;7 years after edge-to-edge therapy for MR, we demonstrated that severe TR at the time of the intervention had an impact on 1-year-survival. Furthermore, a missing periinterventional improvement of TR was shown to be unfavorable regarding the long-term survival of these patients.

Funding Acknowledgement

Type of funding source: None

Visual word form processing deficits driven by severity of reading impairments in children with developmental dyslexia

The visual word form area (VWFA) in the left ventral occipito-temporal (vOT) cortex is key to fluent reading in children and adults. Diminished VWFA activation during print processing tasks is a common finding in subjects with severe reading problems. Here, we report fMRI data from a multicentre study with 140 children in primary school (7.9-12.2 years; 55 children with dyslexia, 73 typical readers, 12 intermediate readers). All performed a semantic task on visually presented words and a matched control task on symbol strings. With this large group of children, including the entire spectrum from severely impaired to highly fluent readers, we aimed to clarify the association of reading fluency and left vOT activation during visual word processing. The results of this study confirm reduced word-sensitive activation within the left vOT in children with dyslexia. Interestingly, the association of reading skills and left vOT activation was especially strong and spatially extended in children with dyslexia. Thus, deficits in basic visual word form processing increase with the severity of reading disability but seem only weakly associated with fluency within the typical reading range suggesting a linear dependence of reading scores with VFWA activation only in the poorest readers.

P11.44 Conception of a promising future therapy: Drug loaded-microbubbles against glioblastoma

BACKGROUND

Major obstacles for an effective chemotherapy of glioblastomas (GBM) are the blood-brain-barrier (BBB) and serious systemic side effects of the cytotoxic drugs. A new promising strategy could be the delivery of microbubbles, encapsulating the chemotherapeutics, across the BBB to the tumor site. This will shield the drug from detrimental systemic effects. Low intensity focused ultrasound (LIFU) is able to open the BBB and triggers targeted release of the drugs within the tumor. First data on the synthesis of microbubbles, specifically designed new drugs and the targeted rupture of microbubbles by LIFU are presented.

MATERIAL AND METHODS

Thin-film hydration of lipids was utilized to prepare microbubbles, which were tested for toxicity on the GBM cell lines GaMG, U87, U138 and U343. In addition these cells were treated with 6 platinum(II) and palladium(II) complexes conjugated to lipophilic side chains of different length (C1, C8, C10) for 72h. To evaluate cell viability and calculate EC50 values MTT assays and a real-time proliferation assay using the impedance-based xCELLigence DP-System were executed.

RESULTS

Microbubbles ≤ 2µm in diameter were synthesized and could be disintegrated by applying LIFU. Neither the intact bubbles nor the lipids alone had any toxic effects on the GBM cells. In contrast, all six drugs were highly effective with EC50 values far below those of Temozolomide (67µM) and in the range of the reference drug cisplatin (3µM). Especially the palladium(II) compound with the C1-chain displayed a very low EC50 value (<10µM), while the longer chains and the platinum(II) compounds were less effective (EC50 10–40µM). An early and concentration-dependent onset of the cytotoxic effect of drugs with C1 and C8 side chains was revealed in the real time proliferation assay.

CONCLUSION

All components for a new microbubble-based therapeutic strategy are in place. Microbubbles were synthesized without having toxic effects in cell culture. New highly potent palladium(II) and platinum(II) compounds with low EC50 values were developed. The next step will be their encapsulation into the microbubbles via their lipophilic side chains to develop an effective drug-delivery system for the treatment of GBM in combination with LIFU. This will allow increasing the local concentration of chemotherapeutic agents at the tumor site, irrespectively of their molecular size and BBB penetration capacity.

High prevalence and functional effects of serum antineuronal antibodies in patients with gastrointestinal disorders

BACKGROUND

Antineuronal antibodies can be associated with both gastrointestinal (GI) and brain disorders. For example, antibodies against the potassium channel subunit dipeptidyl-peptidase-like protein-6 (DPPX) bind to neurons in the central nervous system (CNS) and myenteric plexus and cause encephalitis, commonly preceded by severe unspecific GI symptoms. We therefore investigated the prevalence of antineuronal antibodies indicative of treatable autoimmune CNS etiologies in GI patients.

METHODS

Serum samples of 107 patients (Crohn's disease n = 42, ulcerative colitis n = 16, irritable bowel syndrome n = 13, others n = 36) and 44 healthy controls were screened for anti-DPPX and further antineuronal antibodies using immunofluorescence on rat brain and intestine and cell-based assays. Functional effects of high-titer reactive sera were assessed in organ bath and Ussing chamber experiments and compared to non-reactive patient sera.

KEY RESULTS

Twenty-one of 107 patients (19.6%) had antibodies against the enteric nervous system, and 22 (20.6%) had anti-CNS antibodies, thus significantly exceeding frequencies in healthy controls (4.5% each). Screening on cell-based assays excluded established antienteric antibodies. Antibody-positive sera were not associated with motility effects in organ bath experiments. However, they induced significant, tetrodotoxin (TTX)-insensitive secretion in Ussing chambers compared to antibody-negative sera.

CONCLUSIONS & INFERENCES

Antineuronal antibodies were significantly more frequent in GI patients and associated with functional effects on bowel secretion. Future studies will determine whether such antibodies indicate patients who might benefit from additional antibody-directed therapies. However, well-characterized encephalitis-related autoantibodies such as against DPPX were not detected, underlining their rarity in routine cohorts.

Leukotriene Release from Neutrophils of Patients on Hemodialysis with Cellulose Membranes

The role of cytokines in patients with chronic renal failure is currently under investigation. We therefore studied the release of leukotriene B4 (LTB4) from polymorphonuclear leukocytes (PMN) in stable dialysis patients treated with two different cellulose membranes, Cuprophan and Hemophan®, a modified cellulose with less complement activation. Six patients were treated for four weeks with Cuprophan then switched to Hemophan® for another four weeks. Before and after the last treatment of each period, PMN were separated from 20 ml heparinized blood by FICOLL density gradient centrifugation. Portions of 5x106 PMN were resuspended in Hanks' buffer and stimulated for 5 minutes with calcium ionophore A23187 (5 /μg/ml). LTB4 in cell supernatants was determined by specific radioimmunoassay. PMN from dialysis patients before HD released significantly (p<0.01) more LTB4 than healthy donors. No significant difference between pre- and post-dialysis values was observed with Cuprophan or Hemophan® dialyzers. Our data suggest that the acute effects of blood membrane interaction with either complement activating or non-activating dialyzers do not lead to changes in post-dialysis leukotriene metabolism, but leukotriene production is enhanced chronically in dialysis patients.

Mechanism of 67Ga Accumulation in Normal Rat Liver Lysosomes

67Ga accumulates in various malignant tumors and parenchymatous tissues. It was found to be associated with the soluble fraction of lysosomes (11). The present work investigates the mechanism of 67Ga accumulation in normal liver cells.

Lysosomes were isolated from rat liver after intravenous injection of carrier free 67Ga. The soluble lysosomal fraction was obtained by sonication followed by centrifugation at 105,000 xg for 2 hrs. Gel filtration on Sephadex G 25 superfine was carried out on the soluble lysosomal fraction in order to investigate the stability of the 67Ga-protein complex within the lysosomes under EDTA treatment. After treatment with 1 mM/1 EDTA a considerable amount of the protein bound radioactivity was found to be liberated. In further experiments the 67Ga binding lysosomal proteins were fractionated by electrophoresis on 7% Polyacrylamide gels (0.5 cm x 5.5 cm). After staining with Coomassie blue 18 separated protein bands were apparent. 67Ga distribution within the gels was assessed by direct counting of radioactivity in gel slices. A considerable amount of the intralysosomal protein bound radioactivity migrated with a relative mobility of 0.36 corresponding to a protein band of molecular weight 85,000 — 90,000. This peak corresponded to the peak of 67Ga labeled purified transferrin in control gels. These data were confirmed by Immunoelectrophoresis combined with autoradiography: within the soluble lysosomal fraction a slight transferrin line could be identified.

We conclude that 67Ga which is transported in the blood by transferrin (23) and taken up by the hepatic cell through endocytosis (32) is accumulated in the lysosomes associated with transferrin and its degraded fragments.

A diversity-oriented synthesis of cyclopenta[b]pyrroles and related compounds through a calcium(ii)/copper(ii) catalytic sequence

A sequential bicatalytic route relying on calcium(ii) and copper(ii) salts is described to provide access to original nitrogen-containing heterocycles.

Brain structural alterations associated with dysfunctional cognitive control of pain in patients with low back pain

BACKGROUND

Recent evidence has shown that chronic back pain (CBP) can lead to functional alterations in the circuitry underlying the cognitive control of pain. Thought suppression (TS) is a common type of cognitive control of pain. Previous research has shown that TS has paradoxical effects that may increase the awareness of pain. Pain-related TS may also increase individuals' attention to pain, which may also increase pain sensation, but thus far, the relationship between pain-related TS and structural brain alterations is unknown.

METHODS

In this study, we investigated a group of 30 patients 6 months after lumbar disc surgery by applying voxel-based morphometry (VBM) to identify brain regions correlated with TS scores.

RESULTS

Since pain-related TS has been positively correlated with depression, all calculations were controlled for depression and age. VBM revealed a negative correlation between the TS score and regional grey matter volume (GMV) in the left superior temporal gyrus (LSTG) and the left middle temporal gyrus (L MTG), which is part of the left temporoparietal junction (L TPJ). In addition, a mediation analysis revealed a significant mediation effect of the pain-related TS on the association between GMV of the left TPJ and reported pain intensity in the last 7 days.

CONCLUSIONS

These findings are consistent with previous research on the dysfunctional cognitive control of pain and may therefore provide potential insights into the neural substrates of obstructive cognitive control in chronic low back pain, with a special emphasis on pain-related TS.

SIGNIFICANCE

The link between pain-related thought suppression and brain morphology may provide a new perspective on the understanding of cognitive control of pain in chronic low back pain, which may help improve cognitive behavioural therapy.

Effects of plant-symbiotic relationships on the living soil microbial community and microbial necromass in a long-term agro-ecosystem

We examined the impact of arbuscular mycorrhizal fungi and rhizobia on the living microbial community and microbial necromass under different long-term fertilization treatments at the long-term Static Fertilization Experiment Bad Lauchstädt (Germany). Phospholipid fatty acids (PLFA) and amino sugars plus muramic acid, were used as biomarkers for soil microbial bio- and necromass, respectively, and analyzed from six treatments imposed on two crop rotations, varying only in the inclusion/non-inclusion of a legume. Treatments included: two levels of only farmyard manure (FYM), only mineral fertilizer (NPK), the combined application of both fertilizer types and a non-fertilized control. PLFA profiles differed clearly between the investigated crop rotations and were significantly related to labile C, mineral N, and soil pH. This emphasizes the role of carbon, and of mycorrhizal and rhizobial symbioses, as driver for changes in the microbial community composition due to effects on the living conditions in soil. We found some evidence that legume associated symbiosis with arbuscular mycorrhizal fungi and rhizobia act as a buffer, reducing the impact of varying inputs of mineral nutrients on the decomposer community. While our results support former findings that living microbial populations vary within short-term periods and are reflective of a given crop grown in a given year, soil necromass composition indicates longer term changes across the two crop rotation types, mainly shaped by fertilizer related effects on the community composition and C turnover. However, there was some evidence that specifically the presence of a legume, affects the soil necromass composition not only over the whole crop rotation but even in the short-term.

Role of erythropoietin in the anemia of renal insufficiency in man and in an experimental uremic rabbit model

ESF deficiency is probably not a major contributing factor in the early stages of the anemia of renal insufficiency. Serum ESF titers are lower in advanced renal failure when compared to that of nonuremic anemic subjects suffering from equivalent anemia. With increasing renal insufficiency a relative ESF deficiency gains increasing importance as a pathogenic factor in reduced erythropoiesis. Kidneys without excretory function may still be erythropoietically effective, since a further increase in the anemia occurs after bilateral nephrectomy. However, a basal erythropoiesis is still maintained by extrarenal ESF production, which is also enhanced by hypoxia. ESF deficiency is compensated after successful renal transplantation. A decreased response of the bone marrow to ESF may be another factor contributing to the hypoproliferative state of erythropoiesis in uremia. As demonstrated in a chronic uremic rabbit model there may be a blockade of further differentiation of the erythroid precursors. The relationship of this blockade in differentiation to the inhibitor of heme synthesis is not clear.

Tooth length and incisal wear and growth in guinea pigs (Cavia porcellus) fed diets of different abrasiveness

Dental diseases are among the most important reasons for presenting guinea pigs (Cavia porcellus) and other rodents to veterinary clinics, but the aetiopathology of this disease complex is unclear. Clinicians tend to believe that the ever-growing teeth of rabbits and rodents have a constant growth that needs to be worn down by the mastication of an appropriate diet. In this study, we tested the effect of four different pelleted diets of increasing abrasiveness [due to both internal (phytoliths) and external abrasives (sand)] or whole grass hay fed for 2 weeks each in random order to 16 guinea pigs on incisor growth and wear, and tooth length of incisors and cheek teeth. There was a positive correlation between wear and growth of incisors. Tooth lengths depended both on internal and external abrasives, but only upper incisors were additionally affected by the feeding of whole hay. Diet effects were most prominent in anterior cheek teeth, in particular M1 and m1. Cheek tooth angle did not become shallower with decreasing diet abrasiveness, suggesting that a lack of dietary abrasiveness does not cause the typical 'bridge formation' of anterior cheek teeth frequently observed in guinea pigs. The findings suggest that other factors than diet abrasiveness, such as mineral imbalances and in particular hereditary malocclusion, are more likely causes for dental problems observed in this species.

Performing radical cystectomy and urinary diversion in regional anesthesia: potential risk reduction in the treatment of bladder cancer

OBJECTIVE

To assess the feasibility and performance of radical cystectomy with urinary diversion using exclusively regional anesthesia (i.e. combined spinal thoracic epidural anesthesia, CSTEA), avoiding the adverse effects of general anesthesia.

MATERIALS AND METHODS

In our hospital, radical cystectomy with extended pelvic and iliac lymphadenectomy and urinary diversion was performed on 28 patients using CSTEA without applying general anesthesia, in 2011 and 2012. Under maintained spontaneous breathing, the patients were awake and responsive during the entire procedure. Outcome measurements included operative time, blood loss, start of oral nutrition, start of mobilization, postoperative pain levels using numerical and visual analog scales (NAS/VAS), postoperative complications according to the Clavien-Dindo classification and length of hospital stay.

RESULTS

All surgical procedures were performed without any complications and caused no anesthesiologically or surgically untoward effects. We observed no more severe complications than grade 1 according to the Clavien-Dindo classification.

CONCLUSIONS

Our data show that CSTEA is an effective and safe technique for radical cystectomy, whereby spontaneous breathing and reduced interference with the cardiopulmonary system potentially lower the perioperative risks, especially for high-risk patients. We recommend practice of CSTEA for radical cystectomy to further evaluate and monitor the safety, efficacy, outcomes and complications of CSTEA.

Cystectomy and urinary diversion in the treatment of bladder cancer without artificial respiration

PURPOSE

To assess the feasibility and performance of radical cystectomy with urinary diversion using exclusively regional anesthesia (i.e. combined spinal thoracic epidural anesthesia, CSTEA).

MATERIALS AND METHODS

In 2011 radical cystectomy with extended pelvic and iliac lymphadenectomy was performed on 14 patients using urinary diversion without applying general anesthesia. Under maintained spontaneous breathing, the patients were awake and responsive during the entire procedure. Postoperatively, pain management took three days with the remaining epidural catheter before oral analgesics were administered. Mobilization and diet restoration were carried out according to the fast-track concept. Outcome measurements included operative time, blood loss, beginning of oral nutrition, beginning of mobilization, postoperative pain levels using numerical and visual analog scales (NAS/VAS), length of hospital stay.

RESULTS

All surgical procedures were performed without any complications. The absence of general anesthesia did not result in any relevant disadvantages. The postoperative progress was normal in all patients. Particularly, cardiopulmonary complications and enteroparesis did not occur. The provided palliative care proved sufficient (NAS max. 3-4). Discharge followed 10 to 22 days after surgery. At the time of discharge, the patients described the procedure to be relatively positive.

CONCLUSIONS

Our data show that CSTEA is an effective technique for radical cystectomy, whereby spontaneous breathing and reduced interference with the cardiopulmonary system potentially lower the perioperative risks especially for high-risk patients. We recommend practice of CSTEA for radical cystectomy to further evaluate and monitor the safety, efficacy, outcomes, and complications of CSTEA.