Thoracic sarcopenia as a predictive factor of SARS-COV2 evolution

PURPOSE

Evaluation of CT sarcopenia as a predictor of intensive care hospitalization during SARS-COV2 infection.

MATERIALS AND METHODS

Single-center retrospective study of patients admitted to hospital with SARS-COV2 infection. The estimation of muscle mass (skeletal muscle index (SMI)) for sarcopenia, measurement of muscle density for muscle quality and body adiposity, were based on CT views on the T4 and L3 levels measured at admission. Demographic data, percentage of pulmonary parenchymal involvement as well as the orientation of patients during hospitalization and the risk of hospitalization in intensive care were collected.

RESULTS

A total of 162 patients hospitalized for SARS-COV2 infection were included (92 men and 70 women, with an average age of 64.6 years and an average BMI of 27.4). The muscle area measured at the level of L3 was significantly associated with the patient's unfavorable evolution (124.4cm2 [97; 147] vs 141.5 cm² [108; 173]) (p = 0.007), as was a lowered SMI (p < 0.001) and the muscle area measured in T4 (OR = 0.98 [0.97; 0.99]), (p = 0.026). Finally, an abdominal visceral fat area measured at the level of L3 was also associated with a risk of hospitalization in intensive care (249.4cm2 [173; 313] vs 147.5cm2 [93.1; 228] (p < 0.001).

CONCLUSION

This study demonstrates that thoracic and abdominal sarcopenia are independently associated with an increased risk of hospitalization in an intensive care unit, suggesting the need to assess sarcopenia on admission during SARS-COV2 infection.

Temporal changes in resting heart rate before and after heart failure decompensation in a large real-world population of patients with reduced ejection fraction

Background

Diagnostic parameters measured in implantable cardioverter defibrillators (ICD) and cardiac resynchronization therapy defibrillators (CRTD) have been shown to change before and after heart failure (HF) events with fluid overload.

Purpose

We investigated the temporal characteristics of nighttime heart rate, as a surrogate of resting heart rate, before and after HF events in a large real-world cohort of patients with ICD/CRTD devices.

Methods

We linked a de-identified database of aggregated electronic health record (EHR) data (2007–2017) to a manufacturer's device database with continuous diagnostic monitoring data. Patients with ICD/CRTD implants with HF related diagnostics were included for this study. The device computes nighttime heart rate as the average heart rate between midnight and 4 am. HF event was defined as an inpatient, emergency department, or observation unit stay in a hospital with primary diagnosis of HF and intravenous diuretics administration. Temporal ensemble average of night heart rate in the 60 days pre and post HF events were compared between HF events with and without readmission within 60 days as well as with periods with no HF events.

Results

A total of 17,886 patients with 1.8±1.2 years of follow-up met inclusion criteria. The average age of patients was 66.6±12.3 years, with 72% being males, and 51% with ICD devices. The average night heart rate pre and post HF events with and without readmission and in follow-ups with no events is shown in Figure. A total of 1174 patients had 1425 HF events with no readmission for HF within 60 days and 282 patients had 295 HF events which were followed by readmission for HF within 60 days. A total of 17,839 patients had no HF events over 86,858 follow-up months. A 3-day average night heart rate increased by &gt;3 bpm in a large proportion of patients in the 30-day period before HF event compared to 30-day periods with no events (28% vs 16%; Odds Ratio: 2.08; p&lt;0.001). Patients who were readmitted for HF have higher average NHR before and after admission compared to patients who are not readmitted. In patients who were not readmitted, the night heart rate recovers to baseline levels on an average within 10 days post discharge.

Conclusions

In a large real-world population of patients with ICD/CRTD devices, the average night heart rate increases before HF events. Patients who are readmitted are more likely to have higher night heart rate after discharge.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Medtronic Plc

Temporal characteristics of duration of daily activity before and after heart failure hospitalizations in a large real-world population of patients with cardiovascular implanted electronic devices

Background

Diagnostic parameters measured in implantable cardioverter defibrillators (ICD) and cardiac resynchronization therapy defibrillators (CRTD) have been shown to change before and after heart failure (HF) events with fluid overload.

Purpose

We investigated the temporal characteristics of device measured daily activity duration before and after HF events in a large real-world cohort of patients with ICD/CRTD devices.

Methods

We linked a de-identified database of aggregated electronic health record (EHR) data (2007–2017) to a manufacturer's device database with continuous diagnostic monitoring data. Patients with ICD/CRTD implants with HF diagnostic feature were included for this study. Device accumulates the total number of active minutes during a 24-hour period with an active minute defined as total number of accelerometer fluctuations reaching a threshold during the minute. HF event was defined as an inpatient, emergency department, or observation unit stay in a hospital with primary diagnosis of HF and intravenous diuretics administration. Temporal ensemble average of daily duration of activity in the 60 days pre and post HF events were compared between HF events with and without readmission within 60 days and with periods with no HF events during follow-up.

Results

A total of 17,886 patients with 1.8±1.2 years of follow-up met inclusion criteria. The average age of patients was 66.6±12.3 years, with 72% being males, and 51% with ICD devices. The average daily duration of activity in HF events with and without readmission and with no events is shown in Figure. A total of 1174 patients had 1425 HF events with no readmission for HF within 60 days and 282 patients had 295 HF events which were followed by readmission for HF within 60 days. A total of 17,839 patients had no HF events over 86,858 follow-up months. The 7-day average activity duration decreased by &gt;10 minutes in a large proportion of patients in the 30-day period before HF event compared to 30-day periods with no events (43% vs 34%; Odds Ratio: 1.52; p&lt;0.001). A 7-day average activity duration increase of &gt;10 minutes from admission to 30 days after admission happens in a smaller proportion of HF events with versus without HF readmission within 60 days of index admission (24% vs 31%; Odds Ratio: 0.7; p&lt;0.001).

Conclusions

In a large real-world population of patients with ICD/CRTD devices, the average daily activity duration reduces before HF events. Re-admissions are more likely in patients with smaller increase in activity duration post discharge.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Medtronic Plc

Lower heart rates and beta-blockers are associated with new-onset atrial fibrillation

Background

Lower heart rates (HRs) prolong diastole, thereby raising filling pressures and wall stress (1,2), slowing myocardial relaxation (3), and increasing central blood pressure via superposition of reflected peripheral pressure waves onto systole (2,4). As a result, lower HRs may be associated with higher brain natriuretic peptide (BNP) levels and incident atrial fibrillation (AF). Beta-blockers (BBs) may thereby increase the risk for AF.

Purpose

Examine the relationships of HR, BNP, BB use and new-onset AF in the REVEAL-AF and SPRINT cohort of subjects at risk for developing AF.

Methods

In REVEAL-AF, 383 subjects (52% male, mean age 71.5±9.8 years) without a history of AF and a mean CHA2DS2VASC score of 4.4±1.3 received an insertable cardiac monitor and were followed up to 30 months. Baseline HRs were averaged between 8AM and 8PM for the first week post-implantation. Adjudicated AF lasting ≥6 minutes was defined as new-onset AF.

In SPRINT, 7595 patients (64% male, mean age 67.5±9.2 years) without prior history of AF and a mean CHA2DS2VASC score of 2.3±1.2 were followed for up to 60 months. Baseline average HR was derived from three seated measurements taken at the initial clinical visit. 12-lead ECG at baseline, 2 years, 4 years and close-out visit were used to determine presence of AF. Based on longitudinal medication inventories BB use was categorized into “on BB” vs “never on BB” for the duration of the trial.

Results

The median daytime HR in the REVEAL-AF cohort was 75bpm [interquartile range, IQR 68–83]. Subjects with below median HRs had 2.4-fold higher BNP levels when compared to subjects with above median HRs (median BNP [IQR]: 62pg/dl [37–112] vs. 26pg/dl [13–53], p&lt;0.001). Below median HRs were associated with a higher incidence of AF: 37% vs. 27%, p=0.047. This was validated in the SPRINT cohort after adjusting for AF risk factors (age, HR, sex, body mass index, coronary artery disease, intensive vs standard blood pressure therapy, chronic kidney disease). Both a HR&lt;75bpm and BB use were independently associated with a higher rate of AF: 1.9 vs 0.7%, p&lt;0.001 and 2.5% vs. 0.6%, p&lt;0.001, respectively. The hazard ratio for patients on BB to develop AF was 3.72 [CI 2.32, 5.96], p&lt;0.001.

Conclusion

Lower HRs and BB use are associated with higher BNP levels and incident AF, supporting the hypothesis that lower HRs mimic and/or exacerbate the hemodynamic effects of diastolic dysfunction and promote atrial myopathy. The effects of BBs on clinical outcomes in patient populations outside the context of heart failure with reduced ejection fraction will need to be reassessed.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Institute of Health

Temporal characteristics of an integrated diagnostics risk score before and after heart failure hospitalizations in a large real-world population of patients with implantable devices

Background

Diagnostic parameters measured in implantable cardioverter defibrillators (ICD) and cardiac resynchronization therapy defibrillators (CRTD) have been shown to change before and after heart failure (HF) events with fluid overload.

Purpose

We investigated the temporal characteristics of an integrated diagnostic risk score before and after HF events in a large real-world cohort of patients with ICD/CRTD devices.

Methods

We linked a de-identified database of aggregated electronic health record (EHR) data (2007–2017) to a manufacturer's device database with continuous diagnostic monitoring data. Patients with ICD/CRTD implants with intra-thoracic impedance diagnostic feature were included for this study. The previously defined integrated diagnostic risk score was derived by combining daily diagnostic data, including intra-thoracic impedance, night-time heart rate, activity, heart rate variability, and atrial fibrillation (AF) burden, ventricular rate during AF, CRT pacing, ventricular tachycardia episodes and shocks, in a Bayesian Belief Network framework. HF event was defined as an inpatient, emergency department, or observation unit stay in a hospital with primary diagnosis of HF and intravenous diuretic administration. Temporal average of daily risk score across all patients in the 60 days pre and post HF events were compared in HF events with and without readmission within 60 days and with no HF event during pre and post follow-up days.

Results

A total of 17,886 patients with 1.8±1.2 years of follow-up met inclusion criteria. The average age of patients was 66.6±12.3 years, with 72% being males, and 51% with ICD devices. The average integrated diagnostics risk score in HF events with and without readmission and with no events is shown in Figure. A total of 1174 patients had 1425 HF events with no readmission for HF within 60 days and 282 patients had 295 HF events which were followed by readmission for HF within 60 days. A total of 17,839 patients had no HF events over 86,858 follow-up months. The average daily risk score across all patients was higher on all 60 days pre and post HF event with readmission compared to HF events with no readmission (p&lt;0.001) and both were higher compared to follow-up period with no events (p&lt;0.001). The risk score recovers less often after HF events which are followed by readmission within 60 days compared to HF events with no readmission.

Conclusions

In a large real-world population of patients with ICD/CRTD devices, the average integrated diagnostics risk score was higher before and after HF events with readmission compared to HF events with no readmission. Re-admissions are more likely in patients with smaller risk score recovery after HF events.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Medtronic Plc

Temporal relationship between atrial fibrillation and ischaemic stroke in a large cohort with continuous rhythm monitoring

Background/Introduction

Atrial fibrillation (AF) increases the risk of ischaemic stroke, but the temporal relationship is uncertain.

Purpose

To assess the temporal relationship between AF episodes and ischaemic stroke in patients with cardiovascular implantable electronic devices (CIED) utilizing a case-crossover analysis.

Methods

We linked a very large U.S. aggregated de-identified electronic health record database (2007–2017), containing claims for ischaemic stroke hospitalizations, to a manufacturer's CIED database with continuous AF monitoring. All stroke patients with ≥120 days of pre-stroke rhythm data were included. For each stroke patient, we compared the presence of a day with ≥5.5 hours of AF (the TRENDS study threshold) in the case period (days 1–30 pre-stroke) to that in the control period (days 91–120 pre-stroke). Matched analyses for dichotomous outcomes generated odds ratios with confidence intervals and p values.

Results

We identified 891 ischaemic stroke patients (71.3±10.5 years, 65% male, 27% pacemakers, 60% defibrillators, 13% insertable cardiac monitors) with continuous monitoring data in the 120 days pre-stroke. The vast majority had either no AF in both the case and control periods (n=682, 77%) or AF in both periods (n=143, 16%), i.e., non-informative records. However, among the 66 patients with informative, discordant arrhythmic states, 52 had AF in the case period versus 14 in the control period, for an odds ratio of 3.71 (95% C.I. 2.06–6.70, p&lt;0.001). Analysed by 5-day periods, stroke risk was markedly increased within 30 days of the AF episode (figure). For days 1–5 following an AF episode, the odds ratio was 9.7 (95% C.I. 5.9–16.1). Risk diminished towards non-AF risk after 30 days.

Conclusion

Our analysis of this largest cohort with continuous rhythm monitoring prior to ischaemic stroke demonstrates that stroke risk is highest within a few days of an episode of AF and diminishes rapidly thereafter. Our findings support a strategy of time-limited anticoagulation for patients with infrequent episodes of AF and available continuous rhythm monitoring.

Funding Acknowledgement

Type of funding source: None

Are all CHA2DS2-VASc risk factors created equal? An assessment of stroke risk among 34,470 patients with CHA2DS2-VASc scores of 1 or 2

Introduction

The CHA2DS2-VASc score is commonly used to assess ischemic stroke risk in patients with documented atrial fibrillation (AF). Whether each combination of CHA2DS2-VASc score 1 or 2 confers a similar stroke risk is poorly understood.

Methods

A de-identified database of aggregated electronic health record (EHR) data from 2007–2017 was used to identify patients not on oral anticoagulation (OAC) who had documented AF and CHA2DS2-VASc scores of 1 or 2. CHA2DS2-VASc=1 groups included patients with only heart failure, hypertension, age 65–74, diabetes, vascular disease or female gender. The 17 possible permutations of CHA2DS2-VASc =2 scores were consolidated into 6 groups: prior stroke/TIA, age &gt;75, 2 co-morbidities, 1 co-morbidity + age 65–74, 1 co-morbidity + female gender, or age 65–74 + female gender. Stroke risk hazard ratios were computed for each of these groups.

Results

A total of 34,470 patients (61.0±12.0 years, 67.3% male) not on OAC with a documented history of AF and CHA2DS2-VASc scores of 1 (n=16,572) or 2 (n=17,898) were identified. The annual risks of ischemic stroke among CHA2DS2-VASc 1 and 2 patients were 0.22% [0.18–0.26] and 0.38% [0.33–0.43], respectively. For CHA2DS2-VASc =1 patients, age 65–74 conferred a greater risk of stroke while female gender conferred a lower risk. For CHA2DS2-VASc =2 patients, prior stroke/TIA conferred a greater risk of stroke while 1 co-morbidity + female gender conferred a lower risk [Figure].

Conclusion

Ischemic stroke risk varies significantly across specific risk factors in patients with CHA2DS2-VASc scores =1 or 2. Therefore, OAC decisions in these patients should consider individual risk factors rather than the aggregate score alone.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Medtronic

Radiochemotherapy with gemcitabine as radiosensitizer in patients with soft tissue sarcoma

e23559

Background: Radiation therapy is an essential backbone of the management of patients (pts.) with soft tissue sarcoma (STS) as part of a multimodal curative or palliative treatment. Concurrent external-beam radiation therapy (EBRT) and chemotherapy with doxorubicin (doxo) and ifosfamide (ifo) may be indicated as well, but is associated with relevant toxicity. Gemcitabine (gem) is a known radiosensitizer and has shown activity in STS. The purpose of this study was to evaluate the efficacy and toxicity of concurrent EBRT and gemcitabine. Methods: A single center, retrospective analysis of 12 patients (pts) with STS treated with concurrent EBRT and gemcitabine from Nov 2017 to Dez 2019 in a neoadjuvant (6 pts) or palliative setting (6 pts). Gemcitabine (gem) was administered with 150-300mg/m2 once weekly for the duration of the EBRT (50 Gy in 25 fractions over 5 weeks). In the neoadjuvant treated group, 4 pts had undifferentiated pleomorphic sarcoma (UPS) G3, 1 leiomyosarcoma (LMS) G2 and 1 retroperitoneal G1 liposarcoma (LPS). The pts. were either not eligible for a neoadjuvant systemic treatment with doxo/ifo or received the EBRT/gem treatment in addition to it. Results: 5/6 pts. with neoadjuvant EBRT/gem had R0 resection and 1/6pt. R1. The IUCC stage was IIIB in 5/6 pts and IB in 1/6 pt. The tumor regression grade (TRG) was > 99% in 3/4 pts. with UPS G3 (75%) and 80% in 1/4 pt. with UPS G3. The TRG for the G2 LMS and for the G1 LPS was 20%. All pts treated in palliative setting had high grade sarcoma and responded to the treatment with partial remission, the 6 months’ local control rate was 83% (5/6 pts) for symptomatic fast growing lesions, 1/6 pt. being in PR at 4 months follow up. The combination treatment was well tolerated with reversible skin toxicity CTCAE grade I. As expected transient thrombocytopenia was observed without limiting effect on the planned EBRT. Conclusions: The combination therapy of EBRT and gemcitabine as sensitizer in pts. with STS is feasible und well tolerated. The treatment is an option for patients not eligible for neoadjuvant systemic treatment with doxo/ifo and in the palliative setting as well. It might be more potent than radiation only in achieving tumor regression and local control for high grade STS.

P1887Development and validation of a novel premature ventricular contraction detector in an insertable cardiac monitor

Background

High premature ventricular contraction (PVC) burden may increase the risk of cardiac arrhythmias, PVC-induced cardiomyopathy and heart failure.

Purpose

We developed and validated an algorithm for continuous long-term monitoring of PVC burden in implantable loop recorders or insertable cardiac monitors (ICM).

Methods

The PVC algorithm uses long-short-long RR interval sequence and similarity and differences in r-wave morphology for three consecutive beats to detect the occurrence of a single PVC beat. Various threshold combinations were used for long-short-long RR interval sequence and degree of difference and similarity of R-wave morphology to be able to detect various types of PVCs including monomorphic, polymorphic, bigeminal, trigeminal, and interpolated PVCs. For example, a high degree of difference in R-wave morphology only required the short interval to be less than the longer interval by a smaller amount. The algorithm was designed with the intention to achieve minimum over reporting of PVC burden, i.e. maximum specificity. The algorithm was developed and validated using ECG strips stored in an ICM from real world patients. Gross, patient average and generalized estimating equation (GEE) estimates for sensitivity, specificity, positive and negative predictive value are reported.

Results

The PVC detection algorithm was developed using 87 2-minute ECG strips recorded by an ICM containing 2129 single PVC beats and 12,402 non-PVC beats to obtain a gross sensitivity and specificity of 75.9% and 98.8%. The validation data cohort consisted of 787 ICM recorded ECG strips 7–10 minutes in duration from 134 patients, providing over 460,000 beats of which 439,106 (94%) were normal beats, 8398 (2%) single PVC beats and 16,634 (4%) noisy beats. Couplets and triplets were excluded. Table 1 shows the performance results of the PVC detection algorithm in this validation set.

Performance of PVC detector Gross Patient average GEE (95% CI) Sensitivity 75.2% 69.9% 72.5% (65.8–78.3) Specificity 99.6% 99.4% 99.4% (99.2–99.6) Positive Predictive Value (PPV) 75.9% 40.6% 40.6% (33.6–48.0) Negative Predictive Value (NPV) 99.5% 99.6% 99.6% (99.3–99.7)

Conclusions

The PVC detection algorithm was able to achieve a high specificity, which ensures that 99.6% of the normal events are not incorrectly identified as PVCs, while detecting 75% of PVCs on a continuous long-term basis in insertable cardiac monitors. The accuracy of PVC burden estimates during continuous monitoring using this algorithm needs further validation using Holter studies.

Acknowledgement/Funding

Medtronic Plc

Microfluidic fabrication of polyethylene glycol microgel capsules with tailored properties for the delivery of biomolecules

Microfluidic encapsulation platforms have great potential not only in pharmaceutical applications but also in the consumer products industry. Droplet-based microfluidics is increasingly used for the production of monodisperse polymer microcapsules for biomedical applications. In this work, a microfluidic technique is developed for the fabrication of monodisperse double emulsion droplets, where the shell is crosslinked into microgel capsules. A six-armed acrylated star-shaped poly(ethylene oxide-stat-propylene oxide) pre-polymer is used to form the microgel shell after a photo-initiated crosslinking reaction. The synthesized microgel capsules are hollow, enabling direct encapsulation of large amounts of multiple biomolecules with the inner aqueous phase completely engulfed inside the double emulsion droplets. The shell thickness and overall microgel sizes can be controlled via the flow rates. The morphology and size of the shells are characterized by cryo-SEM. The encapsulation and retention of 10 kDa FITC-dextran and its microgel degradation mediated release are monitored by fluorescence microscopy.

[Normal and Adventitious Breath Sounds]

Auscultation of the lung is an inexpensive, noninvasive and easy-to-perform tool. It is an important part of the physical examination and is help ful to distinguish physiological respiratory sounds from pathophysiological events. Computerized lung sound analysis is a powerful tool for optimizing and quantifying electronic auscultation based on the specific lung sound spectral characteristics. The automatic analysis of respiratory sounds assumes that physiological and pathological sounds are reliably analyzed based on special algorithms. The development of automated long-term lungsound monitors enables objective assessment of different respiratory symptoms.

[Tryptophan immunoadsorption for multiple sclerosis and neuromyelitis optica: therapy option for acute relapses during pregnancy and breastfeeding]

BACKGROUND

Approximately 25 % of women with multiple sclerosis (MS) suffer clinically relevant relapses during pregnancy. Almost all disease-modifying drugs are contraindicated in pregnancy. High-dose glucocorticoids have some serious risks, especially within the first trimester. Tryptophan immunoadsorption (IA) provides a safe option to treat MS relapses during pregnancy.

OBJECTIVES

In this case series we describe for the first time the use of tryptophan IA for MS and neuromyelitis optica (NMO) relapses during pregnancy and breastfeeding.

PATIENTS AND METHODS

In this study a total of 9 patients were retrospectively analyzed of which 7 patients received IA treatment during pregnancy, 2 during breastfeeding and 4-6 tryptophan IA treatments were performed per patient with the single use tryptophan adsorber. Primary outcome was symptom improvement of the relapse.

RESULTS

In this study four patients with MS and one with NMO relapse during pregnancy were treated with IA without preceding glucocorticoid pulse therapy. The MS patients showed improvement in the expanded disability status scale (EDSS) by at least one point, the NMO patient showed significant improvement in visual acuity and two pregnant patients with steroid-refractory relapses showed clinically relevant improvement after IA. Of the patients two suffered from steroid-refractory relapses during breastfeeding and relapse symptoms improved in both cases after treatment with IA. All treatments were well tolerated and no serious adverse events occurred.

CONCLUSION

Tryptophan IA was found to be safe, well-tolerated and effective in the treatment of MS and NMO relapses during pregnancy and breastfeeding, sometimes without preceding glucocorticoid pulse therapy. A binding recommendation is limited without prospective clinical studies.

Evaluation of Study and Patient Characteristics of Clinical Studies in Primary Progressive Multiple Sclerosis: A Systematic Review

Background

So far, clinical studies in primary progressive MS (PPMS) have failed to meet their primary efficacy endpoints. To some extent this might be attributable to the choice of assessments or to the selection of the study population.

Objective

The aim of this study was to identify outcome influencing factors by analyzing the design and methods of previous randomized studies in PPMS patients without restriction to intervention or comparator.

Methods

A systematic literature search was conducted in MEDLINE, EMBASE, BIOSIS and the COCHRANE Central Register of Controlled Trials (inception to February 2015). Keywords included PPMS, primary progressive multiple sclerosis and chronic progressive multiple sclerosis. Randomized, controlled trials of at least one year’s duration were selected if they included only patients with PPMS or if they reported sufficient PPMS subgroup data. No restrictions with respect to intervention or comparator were applied. Study quality was assessed by a biometrics expert. Relevant baseline characteristics and outcomes were extracted and compared.

Results

Of 52 PPMS studies identified, four were selected. Inclusion criteria were notably different among studies with respect to both the definition of PPMS and the requirements for the presence of disability progression at enrolment. Differences between the study populations included the baseline lesion load, pretreatment status and disease duration. The rate of disease progression may also be an important factor, as all but one of the studies included a large proportion of patients with a low progression rate. In addition, the endpoints specified could not detect progression adequately.

Conclusion

Optimal PPMS study methods involve appropriate patient selection, especially regarding the PPMS phenotype and progression rate. Functional composite endpoints might be more sensitive than single endpoints in capturing progression.

Polyglycidol-based metal adhesion promoters

Hydrophilic adhesion promoters that facilitate intimate binding between metals and polymers are an important class of materials with a wide variety of applications in biomedical coatings. Currently, non-poly(meth-)acrylate based hydrophilic polymeric adhesives are unavailable. Here, we report the preparation of such adhesion-promoters based on linear polyglycidol for biomedical applications. The adhesion promoting polymer is prepared from partly phosphonoethylated polyglycidol in three steps. First, the remaining hydroxyl groups of the polyglycidol backbone are reacted with acryloyl chloride; secondly, the phosphonate groups are chemoselectively dealkylated using bromotrimethylsilane. Finally, the bis(trimethylsilyl)phosphonate intermediate is converted to the phosphonic acid through ethanolysis. The reaction conditions of each synthetic step are optimized individually and the products are characterized by ¹H, ³¹P NMR and SEC analysis. The optimized reaction conditions are applied to establish a straightforward one-pot reaction, resulting in an ethanolic formulation of the adhesion promoter, which can be used immediately for the coating application. Special attention is paid to the stability of the intermediates, the chemoselectivity of the reactions and the shelf-life of the product. ¹H NMR spectroscopy reveals hydrolytic instability of the product under ambient conditions; however, the polymers are sufficiently stable in dry ethanol for at least 14 days. The combination of this hydrophilic polymer with acrylate and phosphonic acid groups constitutes a versatile platform technology for the preparation of thin primer coatings on metal substrates for biomedical applications. The phosphonic acid residues assure strong binding to stainless steel wires and the acrylates can be addressed by UV light to enable crosslinking, thus improving mechanical stability and adhesion between the substrate and a biomedical hydrogel coating. The quality of the adhesion promotion to stainless steel wires is verified by using a lubricious, hydrogel top coat and by evaluating friction and wear resistance of this total coating system. Constant values for friction and wear are obtained, proving the applicability of phosphonic acid-functionalized polyglycidols as metal adhesion promoters for biomedical applications.

Induction of endometriosis alters the peripheral and endometrial regulatory T cell population in the non-human primate

BACKGROUND

Endometriosis is a gynecological condition that is characterized by extreme abdominal pain and also decreased fertility. Regulatory T cells (Tregs) have immunosuppressive activity critical for embryonic implantation and likewise the acceptance of tissue engraftment. Utilizing the induced non-human primate (Papio anubis) model of endometriosis, we hypothesize that endometriosis decreases the peripheral and endomet rial Treg profile, whereas ectopic lesions have increased Treg localization.

METHODS

Peripheral blood and endometrium were obtained throughout the menstrual cycle prior to and after induction of disease. Animals were randomly assigned to control (n = 7) or diseased (n = 16) treatment groups. Endometriosis was induced by i.p. injection of autologous menstrual tissue for 2 consecutive months during menses. Peripheral blood and endometrial tissue were collected at d9-11PO at 1, 3, 6, 9, 12 and 15 months post-induction of disease for fluorescence-activated cell sorting, quantitative RT-PCR and immunohistochemistry. Ectopic lesions were excised at 1 and 6 months post-inoculation and also harvested at necropsy (15 months) and processed for RNA of IHC. Identification of Tregs through analysis of FOXP3 expression was conducted utlilizing several methodologies. Differences were determined by non-parametric statistical analysis between all treatment groups and time points.

RESULTS

In control animals, the proportion of peripheral natural Tregs (nTregs) was reduced (P < 0.05) during the mid- and late secretory stages of the menstrual cycle compared with menses. The induction of disease decreased peripheral Treg expression at early time points (P < 0.05) and this remained low throughout the time course, compared with the pre-inoculatory level of an individual. FOXP3 gene expression and Treg populations were also decreased in the eutopic endometrium (P < 0.05) compared with control animals, whereas these parameters were increased in ectopic lesions (P < 0.05), compared with the eutopic endometrium.

CONCLUSIONS

Our data suggest that a reduction in peripheral Tregs may be a causative factor for endometriosis-associated infertility, while the increase in ectopic Treg expression may aid lesion development. Furthermore, endometriosis appears to disrupt Treg recruitment in both eutopic and ectopic endometrium.

Electronic transport and structure of microcrystalline silicon deposited by the VHF-GD technique

Electronic transport parallel and perpendicular to growth direction has been studied in a series of microcrystalline silicon samples obtained by various dilutions of silane in hydrogen. It is clearly shown that the transport properties (dark conductivity, drift mobility, ambipolar diffusion length and photoconductivity) under dark and under illumination conditions are enhanced as the dilution is increased. Furthermore, these films exhibit no degradation upon light-soaking. X-Ray diffraction patterns of the samples confirm that there is a correlation between the amount of crystalline fraction in the samples and the transport properties, as well as a preferential orientation along the growth direction. A similar correlation is found with the shift of the Si-H stretching mode peak of the infrared spectra (IR). Because transport properties have been measured by different techniques (dark conductivity, ambipolar length and photoconductivity in the direction perpendicular to growth direction, drift mobility in the direction parallel to growth direction), no statement can be made about a possible anisotropy in transport, as it would be expected from the columnar shape of the crystallites.

On the Way Towards High Efficiency Thin Film Silicon Solar Cells by the “Micromorph” Concept

Recently the authors have demonstrated that compensated or “midgap” intrinsic hydrogenated microcrystalline silicon (μc-Si:H), as deposited by the Very High Frequency Glow Discharge (VHF-GD) technique, can be used as active layer in p-i-n solar cells. Compared to amorphous silicon (a-Si:H), μc-Si:H was found to have a significantly lower energy bandgap of around 1 eV. The combination of both materials (two absorbers with different gap energies) leads to a “real” tandem cell structure, which was called the “micromorph” cell. Micromorph cells can make better use of the sun's spectrum in contrast to conventional double-stacked a-Si:H / a-Si:H tandems.

The present study will show that the compensation technique (involving boron “microdoping”) used sofar for obtaining midgap μc-Si:H can be replaced by the application of a gas purifier. The use of this gas purifier has a beneficial influence on the transport properties of undoped intrinsic μc-Si:H. By this procedure, increased cell efficiencies in both, single microcrystalline silicon p-i-n as well as micromorph cells could be obtained. In the first case 7.7 % stable, and in the second case 13.1% initial efficiency could be achieved under AM1.5 conditions. Preliminary light-soaking experiments performed on the tandem cells indicate that microcrystalline silicon could contribute to an enhancement of the stable efficiency performance. Micromorph cell manufacturing is fully compatible to a-Si:H technology; however, its deposition rate is still too low. With further increase of the rate, a similar cost reduction potential like in a-Si:H technology can be extrapolated.

[Chiari II malformation. Supportive and predictive value of brainstem reflex and EAEP recordings]

BACKGROUND

In about 20% of patients with Chiari II malformation brainstem signs and symptoms occur. Ventilatory dysfunction is the main cause of death in these patients. The indication for craniocervical decompression is based on clinical examination because supporting electrophysiological or radiological methods were lacking.

METHODS

In a prospective study the clinical courses of 106 patients were documented during a 3-year period. In addition brainstem diagnostic procedures using the masseter reflex (MR), blink reflex (BR) and early auditory evoked potentials (EAEP) were done. Based on the model of binary logistic regression the odds ratio (OR) of progression over time was calculated.

RESULTS

The combination of MR and late BR components showed the highest correlation with clinical findings (OR: 23). The highest predictive value regarding clinical progression over a 3-year period was shown by the combined evaluation of MR, late BR components and EAEP interpeak latency I-V (OR: 17.6). Signs and symptoms had no predictive value.

CONCLUSIONS

Combined brainstem reflex recordings (MR and late BR components) support the clinical examination. To evaluate the long-term prognosis brainstem reflexes and EAEP recordings should be used.

Intravenous immunoglobulin in primary and secondary chronic progressive multiple sclerosis: a randomized placebo controlled multicentre study

In patients with relapsing-remitting multiple sclerosis (MS), IVIG was shown to reduce the relapse rate and progression of disability. In patients with chronic progressive MS, a beneficial effect of IVIG was not documented in placebo controlled studies. This trial investigated the influence of IVIG in primary (PPMS) and secondary (SPMS) chronic progressive MS. Two-hundred and thirty-one patients stratified for PPMS (n=34) and SPMS (n=197) were randomly assigned to IVIG 0.4 g/kg per month or to placebo for 24 months. Primary endpoints were 1) the time to sustained progression of disease identified as worsening of the expanded disability status scale (EDSS) sustained for 3 months, and 2) the improvement of neurological functions defined by a patient's best EDSS score. Secondary endpoints were the proportion of patients with sustained progression, the relapse rate, the assessment of fine motor skills, visual evoked potentials, contrast sensitivity, depression and quality of life. Analysis of the intention-to-treat (ITT) population of combined PPMS and SPMS patients showed that the mean time to sustained progression was 74 weeks in the IVIG compared with 62 weeks in the placebo group (P=0.0406). When PPMS and SPMS patients were analysed separately, the time to sustained progression was also longer in the IVIG group, but the difference was not significant. There was no IVIG-mediated improvement in neurological functions. In the combined per protocol (PP) treated patients, IVIG treatment prolonged time to sustained progression by 13 weeks (P=0.0396). PPMS patients, but not SPMS patients showed a slight favourable IVIG effect on the best EDSS score. In the combined ITT population there were less patients with sustained progression in the IVIG than in the placebo group (P=0.028). The difference was significant in PPMS (P=0.016), but not in SPMS patients. In the combined PP population, there was a trend for a favorable IVIG effect on the rates of patients with sustained progression. In patients with PPMS, this IVIG effect reached significance (P=0.036). Other secondary endpoints did not show significant differences between treatment groups. Eighteen patients with PPMS and 102 patients with SPMS withdrew from the study for various reasons. Treatment was generally well tolerated. It was concluded that monthly IVIG infusion could delay progression of disease in patients with PPMS, and that there was a trend in favour of IVIG treatment in patients with SPMS.