Density of Sphingosine-1-Phosphate Receptors Is Altered in Cortical Nerve-Terminals of Insulin-Resistant Goto-Kakizaki Rats and Diet-Induced Obese Mice

Sphingosine-1-phosphate (S1P) is a phosphosphingolipid with pleiotropic biological functions. S1P acts as an intracellular second messenger, as well as extracellular ligand to five G-protein coupled receptors (S1PR1-5). In the brain, S1P regulates neuronal proliferation, apoptosis, synaptic activity and neuroglia activation. Moreover, S1P metabolism alterations have been reported in neurodegenerative disorders. We have previously reported that S1PRs are present in nerve terminals, exhibiting distinct sub-synaptic localization and neuromodulation actions. Since type 2 diabetes (T2D) causes synaptic dysfunction, we hypothesized that S1P signaling is modified in nerve terminals. In this study, we determined the density of S1PRs in cortical synaptosomes from insulin-resistant Goto-Kakizaki (GK) rats and Wistar controls, and from mice fed a high-fat diet (HFD) and low-fat-fed controls. Relative to their controls, GK rats showed similar cortical S1P concentration despite higher S1P levels in plasma, yet lower density of S1PR1, S1PR2 and S1PR4 in nerve-terminal-enriched membranes. HFD-fed mice exhibited increased plasma and cortical concentrations of S1P, and decreased density of S1PR1 and S1PR4. These findings point towards altered S1P signaling in synapses of insulin resistance and diet-induced obesity models, suggesting a role of S1P signaling in T2D-associated synaptic dysfunction.

Plasma Galectin-4 Levels Are Increased after Stroke in Mice and Humans

Epidemiological studies have associated plasma galectin-4 (Gal-4) levels with prevalent and incident diabetes, and with an increased risk of coronary artery disease. To date, data regarding possible associations between plasma Gal-4 and stroke are lacking. Using linear and logistic regression analyses, we tested Gal-4 association with prevalent stroke in a population-based cohort. Additionally, in mice fed a high-fat diet (HFD), we investigated whether plasma Gal-4 increases in response to ischemic stroke. Plasma Gal-4 was higher in subjects with prevalent ischemic stroke, and was associated with prevalent ischemic stroke (odds ratio 1.52; 95% confidence interval 1.01-2.30; p = 0.048) adjusted for age, sex, and covariates of cardiometabolic health. Plasma Gal-4 increased after experimental stroke in both controls and HFD-fed mice. HFD exposure was devoid of impact on Gal-4 levels. This study demonstrates higher plasma Gal-4 levels in both experimental stroke and in humans that experienced ischemic stroke.

Ivacaftor therapy post myocardial infarction augments systemic inflammation and evokes contrasting effects with respect to tissue inflammation in brain and lung

Acquired cystic fibrosis transmembrane regulator (CFTR) dysfunctions have been associated with several conditions, including myocardial infarction (MI). Here, CFTR is downregulated in brain, heart, and lung tissue and associates with inflammation and degenerative processes. Therapeutically increasing CFTR expression attenuates these effects. Whether potentiating CFTR function yields similar beneficial effects post-MI is unknown. The CFTR potentiator ivacaftor is currently in clinical trials for treatment of acquired CFTR dysfunction associated with chronic obstructive pulmonary disease and chronic bronchitis. Thus, we tested ivacaftor as therapeutic strategy for MI-associated target tissue inflammation that is characterized by CFTR alterations. MI was induced in male C57Bl/6 mice by ligation of the left anterior descending coronary artery. Mice were treated with ivacaftor starting ten weeks post-MI for two consecutive weeks. Systemic ivacaftor treatment ameliorates hippocampal neuron dendritic atrophy and spine loss and attenuates hippocampus-dependent memory deficits occurring post-MI. Similarly, ivacaftor therapy mitigates MI-associated neuroinflammation (i.e., reduces higher proportions of activated microglia). Systemically, ivacaftor leads to higher frequencies of circulating Ly6C⁺ and Ly6C^hi cells compared to vehicle-treated MI mice. Likewise, an ivacaftor-mediated augmentation of MI-associated pro-inflammatory macrophage phenotype characterized by higher CD80-positivity is observed in the MI lung. In vitro, ivacaftor does not alter LPS-induced CD80 and tumor necrosis factor alpha mRNA increases in BV2 microglial cells, while augmenting mRNA levels of these markers in mouse macrophages and differentiated human THP-1-derived macrophages. Our results suggest that ivacaftor promotes contrasting effects depending on target tissue post-MI, which may be largely dependent on its effects on different myeloid cell types.

C57Bl/6N mice have an attenuated lung inflammatory response to dsRNA compared to C57Bl/6J and BALB/c mice

BACKGROUND

Lower respiratory infections caused by ssRNA viruses are a major health burden globally. Translational mouse models are a valuable tool for medical research, including research on respiratory viral infections. In in vivo mouse models, synthetic dsRNA can be used as a surrogate for ssRNA virus replication. However, studies investigating how genetic background of mice impacts the murine lung inflammatory response to dsRNA is lacking. Hence, we have compared lung immunological responses of BALB/c, C57Bl/6N and C57Bl/6J mice to synthetic dsRNA.

METHODS

dsRNA was administered intranasally to BALB/c, C57Bl/6N and C57Bl/6J mice once/day for three consecutive days. Lactate dehydrogenase (LDH) activity, inflammatory cells, and total protein concentration were analyzed in bronchoalveolar lavage fluid (BALF). Pattern recognition receptors levels (TLR3, MDA5 and RIG-I) were measured in lung homogenates using RT-qPCR and western blot. Gene expression of IFN-β, TNF-α, IL-1β and CXCL1 was assessed in lung homogenates by RT-qPCR. ELISA was used to analyze protein concentrations of CXCL1 and IL-1β in BALF and lung homogenates.

RESULTS

BALB/c and C57Bl/6J mice showed infiltration of neutrophils to the lung, and an increase in total protein concentration and LDH activity in response to dsRNA administration. Only modest increases in these parameters were observed for C57Bl/6N mice. Similarly, dsRNA administration evoked an upregulation of MDA5 and RIG-I gene and protein expression in BALB/c and C57Bl/6J, but not C57Bl/6N, mice. Further, dsRNA provoked an increase in gene expression of TNF-α in BALB/c and C57Bl/6J mice, IL-1β only in C57Bl/6N mice and CXCL1 exclusively in BALB/c mice. BALF levels of CXCL1 and IL-1β were increased in BALB/c and C57Bl/6J mice in response to dsRNA, whereas the response of C57Bl/6N was blunt. Overall, inter-strain comparisons of the lung reactivity to dsRNA revealed that BALB/c, followed by C57Bl/6J, had the most pronounced respiratory inflammatory responses, while the responses of C57Bl/6N mice were attenuated.

CONCLUSIONS

We report clear differences of the lung innate inflammatory response to dsRNA between BALB/c, C57Bl/6J and C57Bl/6N mice. Of particular note, the highlighted differences in the inflammatory response of C57Bl/6J and C57Bl/6N substrains underscore the value of strain selection in mouse models of respiratory viral infections.

Alterations to Cerebral Perfusion, Metabolite Profiles, and Neuronal Morphology in the Hippocampus and Cortex of Male and Female Mice during Chronic Exposure to a High-Salt Diet

Excess dietary salt reduces resting cerebral blood flow (CBF) and vascular reactivity, which can limit the fueling of neuronal metabolism. It is hitherto unknown whether metabolic derangements induced by high-salt-diet (HSD) exposure during adulthood are reversed by reducing salt intake. In this study, male and female mice were fed an HSD from 9 to 16 months of age, followed by a normal-salt diet (ND) thereafter until 23 months of age. Controls were continuously fed either ND or HSD. CBF and metabolite profiles were determined longitudinally by arterial spin labeling magnetic resonance imaging and magnetic resonance spectroscopy, respectively. HSD reduced cortical and hippocampal CBF, which recovered after dietary salt normalization, and affected hippocampal but not cortical metabolite profiles. Compared to ND, HSD increased hippocampal glutamine and phosphocreatine levels and decreased creatine and choline levels. Dietary reversal only allowed recovery of glutamine levels. Histology analyses revealed that HSD reduced the dendritic arborization and spine density of cortical and hippocampal neurons, which were not recovered after dietary salt normalization. We conclude that sustained HSD exposure throughout adulthood causes permanent structural and metabolic alterations to the mouse brain that are not fully normalized by lowering dietary salt during aging.

Restoring myocardial infarction-induced long-term memory impairment by targeting the cystic fibrosis transmembrane regulator

BACKGROUND

Cognitive impairment is a serious comorbidity in heart failure patients, but effective therapies are lacking. We investigated the mechanisms that alter hippocampal neurons following myocardial infarction (MI).

METHODS

MI was induced in male C57Bl/6 mice by left anterior descending coronary artery ligation. We utilised standard procedures to measure cystic fibrosis transmembrane regulator (CFTR) protein levels, inflammatory mediator expression, neuronal structure, and hippocampal memory. Using in vitro and in vivo approaches, we assessed the role of neuroinflammation in hippocampal neuron degradation and the therapeutic potential of CFTR correction as an intervention.

FINDINGS

Hippocampal dendrite length and spine density are reduced after MI, effects that associate with decreased neuronal CFTR expression and concomitant microglia activation and inflammatory cytokine expression. Conditioned medium from lipopolysaccharide-stimulated microglia (LCM) reduces neuronal cell CFTR protein expression and the mRNA expression of the synaptic regulator post-synaptic density protein 95 (PSD-95) in vitro. Blocking CFTR activity also down-regulates PSD-95 in neurons, indicating a relationship between CFTR expression and neuronal health. Pharmacologically correcting CFTR expression in vitro rescues the LCM-mediated down-regulation of PSD-95. In vivo, pharmacologically increasing hippocampal neuron CFTR expression improves MI-associated alterations in neuronal arborisation, spine density, and memory function, with a wide therapeutic time window.

INTERPRETATION

Our results indicate that CFTR therapeutics improve inflammation-induced alterations in hippocampal neuronal structure and attenuate memory dysfunction following MI.

FUNDING

Knut and Alice Wallenberg Foundation [F 2015/2112]; Swedish Research Council [VR; 2017-01243]; the German Research Foundation [DFG; ME 4667/2-1]; Hjärnfonden [FO2021-0112]; The Crafoord Foundation; Åke Wibergs Stiftelse [M19-0380], NMMP 2021 [V2021-2102]; the Albert Påhlsson Research Foundation; STINT [MG19-8469], Lund University; Canadian Institutes of Health Research [PJT-153269] and a Heart and Stroke Foundation of Ontario Mid-Career Investigator Award.

P11.35.B The clinical course of long-term survivors after the diagnosis of brain metastasis

Background

To asses demographic and clinical parameters, treatment, and course of disease in patients surviving longer ≥ 5 years after the diagnosis of brain metastasis (BM).

Material and Methods

We retrospectively identified patients who were treated for BM and survived ≥ 5 years after initial BM diagnosis. We analysed and described clinical and treatment related parameters with respect to histology, time to occurrence and systemic/ BM-specific treatment.

Results

We included 48 patients with a mean age of 55 years (range 33-81, SD 12) at diagnosis of primary tumor and 58 (range 41-84, SD 20) at initial BM diagnosis. Histology was non-small-cell lung cancer in 18 (37.5%), melanoma in 14 (29.2%), breast cancer in 11 (22.9%), renal carcinoma in 2 (4.2%), and small-cell lung cancer, cancer of unknown primary and gastrointestinal cancer in one case each (2.1%). Treatment for primary tumor included resection (83.3%), chemotherapy (43.8%), radiation (33.3%), interferon therapy (18.8%), and immuno-/targeted therapy (25%). Most patients received a combination of latter. The mean interval between primary tumor and BM diagnosis was 36 months (range -2 to 277; SD 57). At the time of BM diagnosis, 50% of patients presented with systemically stable disease, 66.7% showed BM related symptoms, 92% showed a KPS ≥70. Most patients had 1 BM (72.9%), while 20.9% had 2-3 and 6.3% >3. Initial treatment for BM comprised resection (60.4%), stereotactic radiosurgery (27.2%), whole-brain-radiation therapy (8.4%), and interstitial brachytherapy (4.2%). Approximately half of the patients (52.1%) suffered from ≥1 BM relapse at initial treatment site. At the time of the analysis, 13 (27.1%) patients had died; cause of death was mostly unknown, in two patients each, systemic/cerebral cause was confirmed. The mean overall survival (OS) was 131 months (range 64-344, SD 68) and 95 (range 60-246, SD 36) after diagnosis of primary tumor and BM, respectively. All patients suffering from melanoma who had received interferon therapy (n=8) survived. Neither systemic status at BM diagnosis nor the administration of novel treatment agents or chemotherapy after BM diagnosis showed an impact on OS (p=0.642, p=0.177 and p=0.628, respectively). Further survival analysis was omitted due to subgroup sizes.

Conclusion

Despite the usually fatal course after BM development, some patients show long-term survival. Whether specific genetic parameters have a particular impact in this subgroup of patients, warrants further investigation.

Cystic fibrosis transmembrane regulator correction attenuates heart failure-induced lung inflammation

Heart failure (HF) affects 64 million people worldwide. Despite advancements in prevention and therapy, quality of life remains poor for many HF patients due to associated target organ damage. Pulmonary manifestations of HF are well-established. However, difficulties in the treatment of HF patients with chronic lung phenotypes remain as the underlying patho-mechanistic links are still incompletely understood. Here, we aim to investigate the cystic fibrosis transmembrane regulator (CFTR) involvement in lung inflammation during HF, a concept that may provide new mechanism-based therapies for HF patients with pulmonary complications. In a mouse model of HF, pharmacological CFTR corrector therapy (Lumacaftor (Lum)) was applied systemically or lung-specifically for 2 weeks, and the lungs were analyzed using histology, flow cytometry, western blotting, and qPCR. Experimental HF associated with an apparent lung phenotype characterized by vascular inflammation and remodeling, pronounced tissue inflammation as evidenced by infiltration of pro-inflammatory monocytes, and a reduction of pulmonary CFTR+ cells. Moreover, the elevation of a classically-activated phenotype of non-alveolar macrophages coincided with a cell-specific reduction of CFTR expression. Pharmacological correction of CFTR with Lum mitigated the HF-induced downregulation of pulmonary CFTR expression and increased the proportion of CFTR+ cells in the lung. Lum treatment diminished the HF-associated elevation of classically-activated non-alveolar macrophages, while promoting an alternatively-activated macrophage phenotype within the lungs. Collectively, our data suggest that downregulation of CFTR in the HF lung extends to non-alveolar macrophages with consequences for tissue inflammation and vascular structure. Pharmacological CFTR correction possesses the capacity to alleviate HF-associated lung inflammation.

Sphingosine 1-Phoshpate Receptors are Located in Synapses and Control Spontaneous Activity of Mouse Neurons in Culture

Sphingosine-1-phosphate (S1P) is best known for its roles as vascular and immune regulator. Besides, it is also present in the central nervous system (CNS) where it can act as neuromodulator via five S1P receptors (S1PRs), and thus control neurotransmitter release. The distribution of S1PRs in the active zone and postsynaptic density of CNS synapses remains unknown. In the current study, we investigated the localization of S1PR1-5 in synapses of the mouse cortex. Cortical nerve terminals purified in a sucrose gradient were endowed with all five S1PRs. Further subcellular fractionation of cortical nerve terminals revealed S1PR2 and S1PR4 immunoreactivity in the active zone of presynaptic nerve terminals. Interestingly, only S1PR2 and S1PR3 immunoreactivity was found in the postsynaptic density. All receptors were present outside the active zone of nerve terminals. Neurons in the mouse cortex and primary neurons in culture showed immunoreactivity against all five S1PRs, and Ca²⁺ imaging revealed that S1P inhibits spontaneous neuronal activity in a dose-dependent fashion. When testing selective agonists for each of the receptors, we found that only S1PR1, S1PR2 and S1PR4 control spontaneous neuronal activity. We conclude that S1PR2 and S1PR4 are located in the active zone of nerve terminals and inhibit neuronal activity. Future studies need to test whether these receptors modulate stimulation-induced neurotransmitter release.

Therapeutic CFTR Correction Normalizes Systemic and Lung-Specific S1P Level Alterations Associated with Heart Failure

Heart failure (HF) is among the main causes of death worldwide. Alterations of sphingosine-1-phosphate (S1P) signaling have been linked to HF as well as to target organ damage that is often associated with HF. S1P's availability is controlled by the cystic fibrosis transmembrane regulator (CFTR), which acts as a critical bottleneck for intracellular S1P degradation. HF induces CFTR downregulation in cells, tissues and organs, including the lung. Whether CFTR alterations during HF also affect systemic and tissue-specific S1P concentrations has not been investigated. Here, we set out to study the relationship between S1P and CFTR expression in the HF lung. Mice with HF, induced by myocardial infarction, were treated with the CFTR corrector compound C18 starting ten weeks post-myocardial infarction for two consecutive weeks. CFTR expression, S1P concentrations, and immune cell frequencies were determined in vehicle- and C18-treated HF mice and sham controls using Western blotting, flow cytometry, mass spectrometry, and qPCR. HF led to decreased pulmonary CFTR expression, which was accompanied by elevated S1P concentrations and a pro-inflammatory state in the lungs. Systemically, HF associated with higher S1P plasma levels compared to sham-operated controls and presented with higher S1P receptor 1-positive immune cells in the spleen. CFTR correction with C18 attenuated the HF-associated alterations in pulmonary CFTR expression and, hence, led to lower pulmonary S1P levels, which was accompanied by reduced lung inflammation. Collectively, these data suggest an important role for the CFTR-S1P axis in HF-mediated systemic and pulmonary inflammation.

Impact of respiratory infectious epidemics on STEMI incidence and care

The effect of respiratory infectious diseases on STEMI incidence, but also STEMI care is not well understood. The Influenza 2017/2018 epidemic and the COVID-19 pandemic were chosen as observational periods to investigate the effect of respiratory virus diseases on these outcomes in a metropolitan area with an established STEMI network. We analyzed data on incidence and care during the COVID-19 pandemic, Influenza 2017/2018 epidemic and corresponding seasonal control periods. Three comparisons were performed: (1) COVID-19 pandemic group versus pandemic control group, (2) COVID-19 pandemic group versus Influenza 2017/2018 epidemic group and (3) Influenza 2017/2018 epidemic group versus epidemic control group. We used Student's t-test, Fisher's exact test and Chi square test for statistical analysis. 1455 patients were eligible. The daily STEMI incidence was 1.49 during the COVID-19 pandemic, 1.40 for the pandemic season control period, 1.22 during the Influenza 2017/2018 epidemic and 1.28 during the epidemic season control group. Median symptom-to-contact time was 180 min during the COVID-19 pandemic. In the pandemic season control group it was 90 min (p = 0.183), and in the Influenza 2017/2018 cohort it was 90 min, too (p = 0.216). Interval in the epidemic control group was 79 min (p = 0.733). The COVID-19 group had a door-to-balloon time of 49 min, corresponding intervals were 39 min for the pandemic season group (p = 0.038), 37 min for the Influenza 2017/2018 group (p = 0.421), and 38 min for the epidemic season control group (p = 0.429). In-hospital mortality was 6.1% for the COVID-19 group, 5.9% for the Influenza 2017/2018 group (p = 1.0), 11% and 11.2% for the season control groups. The respiratory virus diseases neither resulted in an overall treatment delay, nor did they cause an increase in STEMI mortality or incidence. The registry analysis demonstrated a prolonged door-to-balloon time during the COVID-19 pandemic.

Not All Lectins Are Equally Suitable for Labeling Rodent Vasculature

The vascular system is vital for all tissues and the interest in its visualization spans many fields. A number of different plant-derived lectins are used for detection of vasculature; however, studies performing direct comparison of the labeling efficacy of different lectins and techniques are lacking. In this study, we compared the labeling efficacy of three lectins: Griffonia simplicifolia isolectin B4 (IB4); wheat germ agglutinin (WGA), and Lycopersicon esculentum agglutinin (LEA). The LEA lectin was identified as being far superior to the IB4 and WGA lectins in histological labeling of blood vessels in brain sections. A similar signal-to-noise ratio was achieved with high concentrations of the WGA lectin injected during intracardial perfusion. Lectins were also suitable for labeling vasculature in other tissues, including spinal cord, dura mater, heart, skeletal muscle, kidney, and liver tissues. In uninjured tissues, the LEA lectin was as accurate as the Tie2–eGFP reporter mice and GLUT-1 immunohistochemistry for labeling the cerebral vasculature, validating its specificity and sensitivity. However, in pathological situations, e.g., in stroke, the sensitivity of the LEA lectin decreases dramatically, limiting its applicability in such studies. This work can be used for selecting the type of lectin and labeling method for various tissues.

P14.06 Radiomics for the non-invasive determination of the BRAF mutational status in patients with melanoma brain metastases

BACKGROUND

The BRAF V600E mutation is present in approximately 50% of patients with melanoma and is an important prerequisite for a response to targeted therapies such as BRAF inhibitors. In the majority of patients, the BRAF mutational status is based on the analysis of tissue samples from the extracranial primary tumor only. Since the extracranial and intracranial BRAF mutational status may be discrepant, the additional information on the BRAF mutational status of melanoma brain metastases would be of clinical value, e.g., for the prediction of response to targeted therapies. Here, we evaluated the potential of structural MRI radiomics for the determination of the intracranial BRAF mutational status in patients with melanoma brain metastases.

MATERIAL AND METHODS

Fifty-nine patients with melanoma brain metastases from two university hospitals (group 1, 45 patients; group 2, 14 patients) underwent surgery with subsequent genetic analysis of the brain metastases tissue to determine the BRAF mutational status. All patients underwent structural MRI preoperatively. Areas of contrast enhancement were manually segmented and analyzed. Group 1 was used for model training and validation, group 2 for model testing. After image preprocessing, 1,316 radiomics features were extracted using the open-source PyRadiomics package. A test-retest analysis was performed to identify robust features prior to feature selection. Finally, the best performing radiomics model was applied to the test data (group 2). Diagnostic performances were evaluated using receiver operating characteristic (ROC) analyses.

RESULTS

Twenty-two patients (49%) in group 1, and 6 patients (43%) in group 2 had an intrametastatic BRAF V600E mutation. Using a six parameter radiomics signature, a linear support vector machine classifier yielded an average area under the ROC curve (AUC) of 0.87 (accuracy, 85%; sensitivity, 78%; specificity, 91%) for prediction of the BRAF mutational status in the training data (group 1). Finally, the classifier achieved an AUC of 0.85 (accuracy, 86%; sensitivity, 83%; specificity, 88%) in the test data (group 2).

CONCLUSION

The developed radiomics classifier allows a non-invasive prediction of the intracranial BRAF V600E mutational status in patients with melanoma brain metastases and may be of value for treatment decisions.

Plasma S1P (Sphingosine-1-Phosphate) Links to Hypertension and Biomarkers of Inflammation and Cardiovascular Disease: Findings From a Translational Investigation

[Figure: see text].

Improving Cerebrovascular Function to Increase Neuronal Recovery in Neurodegeneration Associated to Cardiovascular Disease

Mounting evidence indicates that the presence of cardiovascular disease (CVD) and risk factors elevates the incidence of cognitive impairment (CI) and dementia. CVD and associated decline in cardiovascular function can impair cerebral blood flow (CBF) regulation, leading to the disruption of oxygen and nutrient supply in the brain where limited intracellular energy storage capacity critically depends on CBF to sustain proper neuronal functioning. During hypertension and acute as well as chronic CVD, cerebral hypoperfusion and impaired cerebrovascular function are often associated with neurodegeneration and can lead to CI and dementia. Currently, all forms of neurodegeneration associated to CVD lack effective treatments, which highlights the need to better understand specific mechanisms linking cerebrovascular dysfunction and CBF deficits to neurodegeneration. In this review, we discuss vascular targets that have already shown attenuation of neurodegeneration or CI associated to hypertension, heart failure (HF) and stroke by improving cerebrovascular function or CBF deficits.

CFTR Therapeutics Normalize Cerebral Perfusion Deficits in Mouse Models of Heart Failure and Subarachnoid Hemorrhage

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The cystic fibrosis transmembrane conductance regulator (CFTR) is a significant modulator of cerebrovascular reactivity; the loss of CFTR function enhances myogenic vasoconstriction.

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Heart failure and subarachnoid hemorrhage downregulate cerebrovascular CFTR protein expression; this leads to enhanced cerebral artery vasoconstriction, reduced cerebral perfusion, neuronal injury, and ultimately, neurologic deficits.

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CFTR therapeutics that maintain CFTR expression normalize the perfusion deficits, reduce neuronal injury, and improve neurologic function in these pathological settings.

Heart failure (HF) and subarachnoid hemorrhage (SAH) chronically reduce cerebral perfusion, which negatively affects clinical outcome. This work demonstrates a strong relationship between cerebral artery cystic fibrosis transmembrane conductance regulator (CFTR) expression and altered cerebrovascular reactivity in HF and SAH. In HF and SAH, CFTR corrector compounds (C18 or lumacaftor) normalize pathological alterations in cerebral artery CFTR expression, vascular reactivity, and cerebral perfusion, without affecting systemic hemodynamic parameters. This normalization correlates with reduced neuronal injury. Therefore, CFTR therapeutics have emerged as valuable clinical tools to manage cerebrovascular dysfunction, impaired cerebral perfusion, and neuronal injury.

Role of the S1P pathway and inhibition by fingolimod in preventing hemorrhagic transformation after stroke

Hemorrhagic transformation (HT) is a complication of severe ischemic stroke after revascularization. Patients with low platelet counts do not receive reperfusion therapies due to high risk of HT. The immunomodulatory drug fingolimod attenuated HT after tissue plasminogen activator in a thromboembolic stroke model, but the underlying mechanism is unknown. Fingolimod acts on several sphingosine-1-phosphate (S1P) receptors, prevents lymphocyte trafficking to inflamed tissues, and affects brain and vascular cells. This study aimed to investigate changes in S1P-signaling in response to brain ischemia/reperfusion and the effects of the S1P receptor modulator fingolimod on HT. We studied brain expression of S1P signaling components, S1P concentration, and immune cell infiltration after ischemia/reperfusion in mice. We administered fingolimod after ischemia to wild-type mice, lymphocyte-deficient Rag2^−/− mice, and mice with low platelet counts. Ischemia increased S1P-generating enzyme SphK1 mRNA, S1P concentration, and S1P receptor-1 (S1P1)⁺ T-cells in the brain. Fingolimod prevented lymphocyte infiltration, and attenuated the severity of HT in Rag2^−/− mice but it was ineffective under thrombocytopenia. Fingolimod prevented β-catenin degradation but not Evans blue extravasation. Ischemia/reperfusion upregulates brain S1P signaling pathway, and fingolimod exerts local effects that attenuate HT. Although fingolimod seems to act on the brain tissue, it did not prevent blood-brain barrier leakage.

PDGF-B Is Required for Development of the Glymphatic System

The glymphatic system is a highly polarized cerebrospinal fluid (CSF) transport system that facilitates the clearance of neurotoxic molecules through a brain-wide network of perivascular pathways. Herein we have mapped the development of the glymphatic system in mice. Perivascular CSF transport first emerges in hippocampus in newborn mice, and a mature glymphatic system is established in the cortex at 2 weeks of age. Formation of astrocytic endfeet and polarized expression of aquaporin 4 (AQP4) consistently coincided with the appearance of perivascular CSF transport. Deficiency of platelet-derived growth factor B (PDGF-B) function in the PDGF retention motif knockout mouse line Pdgfbret/ret suppressed the development of the glymphatic system, whose functions remained suppressed in adulthood compared with wild-type mice. These experiments map the natural development of the glymphatic system in mice and define a critical role of PDGF-B in the development of perivascular CSF transport.

T-Cell Accumulation in the Hypertensive Brain: A Role for Sphingosine-1-Phosphate-Mediated Chemotaxis

Hypertension is considered the major modifiable risk factor for the development of cognitive impairment. Because increased blood pressure is often accompanied by an activation of the immune system, the concept of neuro-inflammation gained increasing attention in the field of hypertension-associated neurodegeneration. Particularly, hypertension-associated elevated circulating T-lymphocyte populations and target organ damage spurred the interest to understanding mechanisms leading to inflammation-associated brain damage during hypertension. The present study describes sphingosine-1-phosphate (S1P) as major contributor to T-cell chemotaxis to the brain during hypertension-associated neuro-inflammation and cognitive impairment. Using Western blotting, flow cytometry and mass spectrometry approaches, we show that hypertension stimulates a sphingosine kinase 1 (SphK1)-dependent increase of cerebral S1P concentrations in a mouse model of angiotensin II (AngII)-induced hypertension. The development of a distinct S1P gradient between circulating blood and brain tissue associates to elevated CD3+ T-cell numbers in the brain. Inhibition of S1P₁-guided T-cell chemotaxis with the S1P receptor modulator FTY720 protects from augmentation of brain CD3 expression and the development of memory deficits in hypertensive WT mice. In conclusion, our data highlight a new approach to the understanding of hypertension-associated inflammation in degenerative processes of the brain during disease progression.

The emerging alliance of sphingosine-1-phosphate signalling and immune cells: from basic mechanisms to implications in hypertension

The immune system plays a considerable role in hypertension. In particular, T-lymphocytes are recognized as important players in its pathogenesis. Despite substantial experimental efforts, the molecular mechanisms underlying the nature of T-cell activation contributing to an onset of hypertension or disease perpetuation are still elusive. Amongst other cell types, lymphocytes express distinct profiles of GPCRs for sphingosine-1-phosphate (S1P) - a bioactive phospholipid that is involved in many critical cell processes and most importantly majorly regulates T-cell development, lymphocyte recirculation, tissue-homing patterns and chemotactic responses. Recent findings have revealed a key role for S1P chemotaxis and T-cell mobilization for the onset of experimental hypertension, and elevated circulating S1P levels have been linked to several inflammation-associated diseases including hypertension in patients. In this article, we review the recent progress towards understanding how S1P and its receptors regulate immune cell trafficking and function and its potential relevance for the pathophysiology of hypertension. LINKED ARTICLES: This article is part of a themed section on Immune Targets in Hypertension. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.12/issuetoc.

Prediction model for obtaining spermatozoa with testicular sperm extraction in men with non-obstructive azoospermia

STUDY QUESTION

Can an externally validated model, based on biological variables, be developed to predict successful sperm retrieval with testicular sperm extraction (TESE) in men with non-obstructive azoospermia (NOA) using a large nationwide cohort?

SUMMARY ANSWER

Our prediction model including six variables was able to make a good distinction between men with a good chance and men with a poor chance of obtaining spermatozoa with TESE.

WHAT IS KNOWN ALREADY

Using ICSI in combination with TESE even men suffering from NOA are able to father their own biological child. Only in approximately half of the patients with NOA can testicular sperm be retrieved successfully. The few models that have been developed to predict the chance of obtaining spermatozoa with TESE were based on small datasets and none of them have been validated externally.

STUDY DESIGN, SIZE, DURATION

We performed a retrospective nationwide cohort study. Data from 1371 TESE procedures were collected between June 2007 and June 2015 in the two fertility centres.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All men with NOA undergoing their first TESE procedure as part of a fertility treatment were included. The primary end-point was the presence of one or more spermatozoa (regardless of their motility) in the testicular biopsies.We constructed a model for the prediction of successful sperm retrieval, using univariable and multivariable binary logistic regression analysis and the dataset from one centre. This model was then validated using the dataset from the other centre. The area under the receiver-operating characteristic curve (AUC) was calculated and model calibration was assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 599 (43.7%) successful sperm retrievals after a first TESE procedure. The prediction model, built after multivariable logistic regression analysis, demonstrated that higher male age, higher levels of serum testosterone and lower levels of FSH and LH were predictive for successful sperm retrieval. Diagnosis of idiopathic NOA and the presence of an azoospermia factor c gene deletion were predictive for unsuccessful sperm retrieval. The AUC was 0.69 (95% confidence interval (CI): 0.66-0.72). The difference between the mean observed chance and the mean predicted chance was <2.0% in all groups, indicating good calibration. In validation, the model had moderate discriminative capacity (AUC 0.65, 95% CI: 0.62-0.72) and moderate calibration: the predicted probability never differed by more than 9.2% of the mean observed probability.

LIMITATIONS, REASONS FOR CAUTION

The percentage of men with Klinefelter syndrome among men diagnosed with NOA is expected to be higher than in our study population, which is a potential selection bias. The ability of the sperm retrieved to fertilize an oocyte and produce a live birth was not tested.

WIDER IMPLICATIONS OF THE FINDINGS

This model can help in clinical decision-making in men with NOA by reliably predicting the chance of obtaining spermatozoa with TESE.

STUDY FUNDING/COMPETING INTEREST

This study was partly supported by an unconditional grant from Merck Serono (to D.D.M.B. and K.F.) and by the Department of Obstetrics and Gynaecology of Radboud University Medical Center, Nijmegen, The Netherlands, the Department of Obstetrics and Gynaecology, Jeroen Bosch Hospital, Den Bosch, The Netherlands, and the Department of Obstetrics and Gynaecology, Academic Medical Center, Amsterdam, The Netherlands. Merck Serono had no influence in concept, design nor elaboration of this study.

TRIAL REGISTRATION NUMBER

Not applicable.

Prediction model for live birth in ICSI using testicular extracted sperm

STUDY QUESTION

Which parameters have a predictive value for live birth in couples undergoing ICSI after successful testicular sperm extraction (TESE-ICSI)?

SUMMARY ANSWER

Female age, a first or subsequent started TESE-ICSI cycle, male LH, male testosterone, motility of the spermatozoa during the ICSI procedure and the initial male diagnosis before performing TESE were identified as relevant and independent parameters for live birth after TESE-ICSI.

WHAT IS KNOWN ALREADY

In reproductive medicine prediction models are used frequently to predict treatment success, but no prediction model currently exists for live birth after TESE-ICSI.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study between 2007 and 2015 in two academic hospitals including 1559 TESE-ICSI cycles. The prediction model was developed using data from one centre and validation was performed with data from the second centre.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included couples undergoing ICSI treatment with surgically retrieved sperm from the testis for the first time. In the development set we included 526 couples undergoing 1006 TESE-ICSI cycles. In the validation set we included 289 couples undergoing 553 TESE-ICSI cycles. Multivariable logistic regression models were constructed in a stepwise fashion (P < 0.2 for entry). The external validation was based on discrimination and calibration.

MAIN RESULTS AND THE ROLE OF CHANCE

We included 224 couples (22.3%) with a live birth in the development set. The occurrence of a live birth was associated with lower female age, first TESE-ICSI cycle, lower male LH, higher male testosterone, the use of motile spermatozoa for ICSI and having obstructive azoospermia as an initial suspected diagnosis. The area under the receiver operating characteristic (ROC) curve was 0.62. From validation data, the model had moderate discriminative capacity (c-statistic 0.67, 95% confidence interval: 0.62-0.72) but calibrated well, with a range from 0.06 to 0.56 in calculated probabilities.

LIMITATIONS, REASONS FOR CAUTION

We had a lack of data about the motility of spermatozoa during TESE, therefore, we used motility of the spermatozoa used for ICSI after freeze-thawing, information which is only available during treatment. We had to exclude data on paternal BMI in the model because too many missing values in the validation data hindered testing. We did not include a histologic diagnosis, which would have made our data set less heterogeneous and, finally, our model may not be applicable in centres which have a different policy for the indication for performing sperm extraction. The prognostic value of the model is limited because of a low 'area under the curve'.

WIDER IMPLICATIONS OF THE FINDINGS

This model enables the differentiation between couples with a low or high chance to reach a live birth using TESE-ICSI. As such it can aid in the counselling of patients and in clinical decision-making.

STUDY FUNDING/COMPETING INTERESTS

This study was partly supported by an unconditional grant from Merck Serono (to D.D.M.B. and K.F.) and by the Department of Obstetrics and Gynaecology of Radboud University Medical Center, Nijmegen, The Netherlands, the Department of Obstetrics and Gynaecology, Jeroen Bosch Hospital, Den Bosch, The Netherlands, and the Department of Obstetrics and Gynaecology, Academic Medical Center, Amsterdam, The Netherlands. Merck Serono had no influence in concept, design, nor elaboration of this study.

TRIAL REGISTRATION NUMBER

Not applicable.

Hypertension and the Brain: A Risk Factor for More Than Heart Disease

Background: Cerebral small vessel disease (cSVD), a common risk factor for cognitive impairment, involves unspecific arteriopathy characterized by hypertrophy and endothelial dysfunction that alter cerebrovascular function and auto-regulation of cerebral blood flow (CBF). Microbleedings, subcortical lacunar infarctions and diffuse areas of white matter lesions resulting from vascular injury are associated with reduced cognitive function mostly characterized by difficulties in learning and retention, attention deficits, gait disorders or depression. In recent years, it has become evident that vascular risk factors contribute to the development of cSVD and associated vascular cognitive impairment (VCI). Among them, hypertension emerged as such a major modifiable risk factor since the brain presents an early target for organ damage due to changes in blood pressure (BP). Subsequently both high and, especially in the elderly, low BP have been linked to cognitive decline, which initiated controversial discussions about BP control as a potential therapeutic strategy to achieve optimal brain perfusion and thus, reduce the occurrence of cSVD and cognitive dysfunction. Yet, recent randomized controlled trials examined the impact of anti-hypertensive therapy on cognitive performance with conflicting results. Summary: In light of the current knowledge, it becomes apparent that there is an urgent need to understand the mechanisms underlying hypertension-induced cerebrovascular complications in order to identify effective therapeutic targets to prevent and most importantly also reverse cognitive decline mediated through hypertension. Key Message: This review summarizes the current knowledge of cSVD pathogenesis as well as possible links to hypertension-mediated cerebrovascular complications. By pointing out knowledge gaps, it aims to spur future studies in search of specific targets helping to prevent therapy failures and decelerate the rapidly progressing neuro-degeneration of patients suffering from cerebrovascular diseases emanating from hypertension.

Couples with non-obstructive azoospermia are interested in future treatments with artificial gametes

STUDY QUESTION

Would couples diagnosed with non-obstructive azoospermia (NOA) consider two future treatments with artificial gametes (AGs) as alternatives for testicular sperm extraction followed by ICSI (TESE-ICSI)?

SUMMARY ANSWER

Most couples with NOA (89%) would opt for treatment with AGs before attempting TESE-ICSI and/or after failed TESE-ICSI.

WHAT IS KNOWN ALREADY

Couples with NOA who undergo TESE-ICSI have a 25% chance of conceiving a child. Two future treatments that are being developed are 'ICSI with artificial sperm formed from somatic cells' (ICSI with AGs) and 'natural conception after autotransplantation of in vitro proliferated spermatogonial stem cells' (natural conception with AGs). It is unknown what treatment preferences patients have.

STUDY DESIGN, SIZE, DURATION

A cross-sectional survey conducted in 2012-2013, addressing all 921 couples diagnosed with NOA and treated with TESE-ICSI in Dutch fertility clinics between 2007 and 2012. The coded questionnaires were sent by mail and followed up with two reminders.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We developed the questionnaire based on a literature review and previous qualitative interviews, and included treatment preference and the valuation of nine treatment characteristics. We assessed reliability of the questionnaires and calculated mean importance scores (MISs: 0-10) of each treatment characteristic. We assessed which patient and treatment characteristics were associated with a couple's hypothetical treatment preference using binominal regression.

MAIN RESULTS AND THE ROLE OF CHANCE

The vast majority (89%) of the 494 responding couples (response rate: 54%) would potentially opt for AGs as a first and/or a last resort treatment option. More specifically, as a first treatment couples were likely (67%) to prefer natural conception with AGs over TESE-ICSI and less likely to prefer ICSI with AGs over TESE-ICSI (34%). After failed TESE-ICSI, the majority of couples (75%) would want to attempt ICSI with AGs as a last resort option. The most important characteristics of treatment were safety for children (MIS: 8.2), pregnancy rates (MIS: 7.7) and curing infertility (MIS: 6.8). Costs, burden, naturalness and technological sophistication were of about equal importance (MIS: 3.1-4.0). The majority of patients rated conception at home and moral acceptability as not important (MIS: 1.7 and 0.8, respectively), but the importance attributed to these variables did still affect patients' likeliness to opt for AGs.

LIMITATIONS AND REASONS FOR CAUTION

Couples with NOA not opting for TESE-ICSI were not included and might have other perspectives. Couples' hypothetical choices for AGs might differ from their actual choices once data on the costs, safety and pregnancy rates become available from these new treatment options.

WIDER IMPLICATIONS OF THE FINDINGS

The interest of couples with NOA in potential future treatments with AGs encourages further pre-clinical research. Priority setting for research and future decision-making on clinical application of AGs should take all characteristics important to patients into account.

STUDY FUNDING/COMPETING INTERESTS

The authors report no financial or other conflict of interest relevant to the subject of this article.

[Comparison of Costs and Revenues in Conservative and Invasive Treatment in Cardiology: a Contribution Margin Analysis]

Aim of the study: Direct costing is a specialized form of cost analysis well suited for medical areas with DRG-orientated flat rate payments. By comparing case-related variable costs and payments, it is possible to compare the economic benefits of different medical treatments. This aim was pursued by developing a direct costing concept and by its application to invasively and non-invasively treated cardiac patients. Methods: The entire database comprised 7 330 cases of a tertiary cardiac center between 2007 and 2011. It was derived from databases of the hospital information system, the materials management department and the catheter laboratory. On the revenue side, DRG payments were included. Costs related to heart catheterization such as material, personnel and maintenance expenses were considered to be variable costs. Contribution margins and relative contribution margins were calculated by introducing the length of hospital stay as a time reference. Results: During the observation period, caseload and annual revenues increased by about 20 percent. Contribution margins were higher in invasively than in non-invasively treated patients (2 097±1 590 vs. 1 614±1 105 €; p<0,001). However, the relative relation of both patient groups was not altered during the observation period. A remarkable shortening of the duration of catheter laboratory examinations was observed between 2007 and 2011 (46,2±39,1 auf 36,7±33,5 min; p<0,001). In the same period, relative contribution margins increased from 461±306 to 530±335 € (p<0,001). Conclusions: Within existing supply structures, direct costing is a useful tool for economic comparison of different treatment services. Furthermore, temporal constraints of an economic bottleneck can be easily monitored and tackled with the help of time management tools.

Therapeutically Targeting Tumor Necrosis Factor-α/Sphingosine-1-Phosphate Signaling Corrects Myogenic Reactivity in Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

Subarachnoid hemorrhage (SAH) is a complex stroke subtype characterized by an initial brain injury, followed by delayed cerebrovascular constriction and ischemia. Current therapeutic strategies nonselectively curtail exacerbated cerebrovascular constriction, which necessarily disrupts the essential and protective process of cerebral blood flow autoregulation. This study identifies a smooth muscle cell autocrine/paracrine signaling network that augments myogenic tone in a murine model of experimental SAH: it links tumor necrosis factor-α (TNFα), the cystic fibrosis transmembrane conductance regulator, and sphingosine-1-phosphate signaling.

METHODS

Mouse olfactory cerebral resistance arteries were isolated, cannulated, and pressurized for in vitro vascular reactivity assessments. Cerebral blood flow was measured by speckle flowmetry and magnetic resonance imaging. Standard Western blot, immunohistochemical techniques, and neurobehavioral assessments were also used.

RESULTS

We demonstrate that targeting TNFα and sphingosine-1-phosphate signaling in vivo has potential therapeutic application in SAH. Both interventions (1) eliminate the SAH-induced myogenic tone enhancement, but otherwise leave vascular reactivity intact; (2) ameliorate SAH-induced neuronal degeneration and apoptosis; and (3) improve neurobehavioral performance in mice with SAH. Furthermore, TNFα sequestration with etanercept normalizes cerebral perfusion in SAH.

CONCLUSIONS

Vascular smooth muscle cell TNFα and sphingosine-1-phosphate signaling significantly enhance cerebral artery tone in SAH; anti-TNFα and anti-sphingosine-1-phosphate treatment may significantly improve clinical outcome.

Tumor Necrosis Factor-α Underlies Loss of Cortical Dendritic Spine Density in a Mouse Model of Congestive Heart Failure

Background

Heart failure (HF) is a progressive disorder characterized by reduced cardiac output and increased peripheral resistance, ultimately leading to tissue perfusion deficits and devastating consequences for several organs including the brain. We previously described a tumor necrosis factor-α (TNF-α)–dependent enhancement of posterior cerebral artery tone and concomitant reduced cerebral blood flow in a mouse model of early HF in which blood pressure remains minimally affected. HF is often associated with cognitive impairments such as memory deficits, even before any overt changes in brain structure and function occur. The pathophysiology underlying the development of cognitive impairments in HF is unknown, and appropriate treatment strategies are lacking.

Methods and Results

We used a well-established mouse model in which HF was induced by experimental myocardial infarction produced by permanent surgical ligation of the left anterior descending coronary artery (infarct size ≈25% of the left ventricular wall). Ligated mice developed enlarged hearts, congested lungs, and reduced cardiac output and blood pressure, with elevated peripheral resistance within 6 to 8 weeks after ligation. In this study, we demonstrated the significance of the proinflammatory cytokine TNF-α during HF-mediated neuroinflammation and associated impaired hippocampus-independent nonspatial episodic memory function. Augmented cerebral TNF-α expression and microglial activation in HF mice, indicative of brain inflammation, were accompanied by morphological changes and significant reduction of cortical dendritic spines (61.39±8.61% for basal and 61.04±9.18% for apical spines [P<0.001]). The significance of TNF-α signaling during the observed HF-mediated neurodegenerative processes is supported by evidence showing that sequestration or genetic deletion of TNF-α ameliorates the observed reduction of cortical dendritic spines (33.51±7.63% for basal and 30.13±6.98% for apical spines in wild-type mice treated with etanercept; 17.09±6.81% for basal and 17.21±7.29% for apical spines in TNF-α^−/−). Moreover, our data suggest that alterations in cerebral serum and glucocorticoid-inducible kinase 1 (SgK1) expression and phosphorylation during HF may be TNF-α dependent and that an increase of SgK1 phosphorylation potentially plays a role in the HF-associated reduction of dendritic spine density.

Conclusions

Our findings demonstrate that TNF-α plays a pivotal role in HF-mediated neuroinflammation and associated alterations of cortical dendritic spine density and has the potential to reveal novel treatment strategies for HF-associated memory deficits.

[Prophylaxis and therapy for atrial fibrillation after general thoracic surgery]

Following thoracic surgery atrial fibrillation (AF) frequently occurs in 12 to 44 % of cases postoperatively and is related to an increased morbidity and mortality. In 2011, the Society of Thoracic Surgeons of the United States published guidelines for the prophylaxis and treatment of postoperative AF. High evidence levels are provided for continuing β-blocker treatment despite its known negative inotropic effects. Alternatively, the calcium channel blocker diltiazem, or amiodarone for patients without pneumonectomy are recommended for prophylactic therapy. For rate control of AF occurring post surgery, not only selective β1-blockers, calcium channel blockers, but also magnesium or digoxin are suitable in haemodynamically stable patients. Amiodarone, β1-blockers and flecainide are preferred for rhythm control in case of haemodynamic stability in regard to possible side effects and contraindications. In contrast, electrical cardioversion is indicated in those patients with haemodynamic instability. Persistent AF of > 48 hours is a target for anticoagulation treatment depending on the individual aspects of the patient and in accordance to the CHADS2 score. The present review article further discusses the evidence for the recommended medical therapy and treatment strategies.

Publication rates of abstracts presented at the 2007 and 2010 Canadian Association of Radiation Oncology meetings

BACKGROUND

We set out to determine the rate, time-trend, and defining factors associated with publication of abstracts presented at two annual scientific meetings of the Canadian Association of Radiation Oncology (caro).

METHODS

All abstracts accepted for oral presentation in 2007 and 2010 were obtained from the caro program archives and searched using the PubMed database. Variables in the dataset included the year of presentation at caro and of publication in a scientific journal, time to publication (in months), publishing journal, impact factor of publishing journal, abstract research type (clinical, technical, or basic science) and disease site, country of origin, and university of the first author.

RESULTS

Overall, 88 of 172 abstracts from the 2007 (n = 102) and 2010 (n = 70) caro meetings were published in peer-reviewed journals (publication rate: 51.2%). Mean time to publication was 18.5 months. Among research types, clinical research (62.5%) and, among disease sites, prostate cancer (40.4%) were most likely to be published. Of all the abstracts, 50.1% were contributed by only 2 universities, a proportion that resembles the overall abstract publication rate of 51.2%. The conversion rate for those 2 universities (51.1%) is very similar to that for all abstracts presented at the two meetings.

CONCLUSIONS

Half the abstracts presented at the 2007 and 2010 caro meetings were ultimately published in journals indexed in PubMed by about 1.5 years after presentation. Half the abstracts and publications came from just 2 universities; more must to be done to close the gap.

Perspectives of infertile men on future stem cell treatments for nonobstructive azoospermia

Concerns have been expressed about the rapid introduction of new fertility treatments into clinical practice. Patients' perspectives on new treatments and their introduction into clinical practice are unexplored. Two alternative treatments for testicular sperm extraction followed by intracytoplasmic sperm injection in men with nonobstructive azoospermia (NOA), the formation of artificial sperm and autotransplantation of in vitro proliferated spermatogonial stem cells, are in a preclinical phase of development. This study aimed to explore, prior to future clinical introduction, which treatment aspects are valued by NOA patients and would be taken into account in deciding to undergo these future treatment options. In-depth telephone interviews were conducted with 14 men with NOA. Interviews were transcribed, analysed with content analysis and data saturation was reached. Besides the obvious factors, success rates and safety, patients valued 'the intensity of the procedure', 'the treatments' resemblance to natural conception' and 'feeling cured'. Patients supported the development of these treatments and were eager to take part if such treatments would become available in the future. The patient's perspective on innovative treatments can (co)direct reproductive research. More research into the patients' perspectives on innovations and minimal thresholds to be met prior to their introduction into clinical practice is required.

Angular momentum sensitive two-center interference

In quantum mechanics the Young-type double-slit experiment can be performed with electrons either traveling through a double slit or being coherently emitted from two inversion symmetric molecular sites. In the latter one the valence photoionization cross sections of homonuclear diatomic molecules were predicted to oscillate over kinetic energy almost 50 years ago. Beyond the direct proof of the oscillatory behavior of these photoionization cross sections σ, we show that the angular distribution of the emitted electrons reveals hitherto unexplored information on the relative phase shift between the corresponding partial waves through two-center interference patterns.

Synthesis, pH-dependent, and plasma stability of meropenem prodrugs for potential use against drug-resistant tuberculosis

Meropenem, a broad-spectrum parenteral β-lactam antibiotic, in combination with clavulanate has recently shown efficacy in patients with extensively drug-resistant tuberculosis. As a result of meropenem's short half-life and lack of oral bioavailability, the development of an oral therapy is warranted for TB treatment in underserved countries where chronic parenteral therapy is impractical. To improve the oral absorption of meropenem, several alkyloxycarbonyloxyalkyl ester prodrugs with increased lipophilicity were synthesized and their stability in physiological aqueous solutions and guinea pig as well as human plasma was evaluated. The stability of prodrugs in aqueous solution at pH 6.0 and 7.4 was significantly dependent on the ester promoiety with the major degradation product identified as the parent compound meropenem. However, in simulated gastrointestinal fluid (pH 1.2) the major degradation product identified was ring-opened meropenem with the promoiety still intact, suggesting the gastrointestinal environment may reduce the absorption of meropenem prodrugs in vivo unless administered as an enteric-coated formulation. Additionally, the stability of the most aqueous stable prodrugs in guinea pig or human plasma was short, implying a rapid release of parent meropenem.

Abstract WP262: Therapeutically Targeting TNFa-S1P Signaling Restores Microvascular Reactivity after Experimental Subarachnoid Hemorrhage

Background: Subarachnoid hemorrhage (SAH) is characterized by an initial hemorrhagic and ischemic brain injury followed by delayed macro- and microvascular constriction. Large-artery vasospasm and enhanced microcirculatory myogenic tone may contribute to delayed cerebral ischemia. Although this implies that therapeutic interventions must specifically correct the SAH-induced myogenic tone enhancement, current therapeutic approaches non-selectively interfere with vasoconstriction and risk disrupting cerebral autoregulation. This may explain why most interventions do not improve clinical outcome. This study identifies the molecular basis for exacerbated cerebrovascular constriction and validates new targets for SAH treatment.

Methods: Wild-type, tumor necrosis factor α (TNFα) knockout, sphingosine-1-kinase (Sphk1) knockout and inducible, smooth muscle cell-targeted TNFα knockout mice were used. SAH was created by injection of 80 μl of arterial blood into the prechiasmatic cistern. Myogenic tone in the olfactory artery was assessed with a myograph system. Standard procedures for fluorescent immunolocalization, Western blotting and assessment of apoptosis were used.

Results: SAH increased myogenic tone and vascular wall TNFα expression, without enhancing overall vascular contractility in response to phenylephrine. Knockout of TNFα globally or smooth muscle cell-specifically prevented SAH-induced increased myogenic tone. Inhibition of TNFα-shedding (TAPI, 50 μmol/L) or receptor-binding (etanercept, 10 mg/ml) eliminated SAH-mediated myogenic tone augmentation. Cystic fibrosis transmembrane regulator (CFTR) protein expression was down-regulated in cerebral arteries after SAH, which was abolished by antagonism of TNFα. Genetic mouse models confirmed that S1P signaling mediates the myogenic tone augmentation in SAH. Finally, disrupting TNFα signaling attenuated neuronal apoptosis in SAH animals.

Conclusion: We identify a novel smooth muscle cell autocrine/paracrine signaling network that augments myogenic tone in SAH. It links TNFα, CFTR and sphingosine-1-phosphate (S1P) signaling. Targeting TNFα and the S1P 2 receptor subtype are potential therapeutic options to improve clinical outcome in SAH.

[Echocardiographic tissue Doppler imaging analysis of the systolic and early diastolic velocities of the mitral annulus motion in hypertrophic cardiomyopathy and in top-level athletes]

BACKGROUND AND OBJECTIVE

Echocardiographic Tissue Doppler Imaging (TDI) has been proposed for the differentiation of pathological left ventricular hypertrophy (e. g. hypertrophic cardiomyopathy, HCM) and physiologic left ventricular hypertrophy (athlete's heart). The aim of this study was the TDI analysis of the systolic (S') and early diastolic (E') velocities in patients (pts.) with non-obstructive hypertrophic cardiomyopathy (HCM) and in top-level athletes in consideration of the previously published cut-off values (S' < 9 cm/s, E' < 9 cm/s).

PATIENTS AND METHODS

Pulsed-wave TDI of the systolic and early-diastolic velocities was performed at the lateral and septal mitral annulus in the four-chamber view in 17 HCM pts (12 men; mean age 44 ± 16 years) and 80 consecutive athletes (80 men; mean age 26 ± 5 years).

RESULTS

Pts with HCM showed significantly decreased systolic velocities of the septal (S' septal: 5.1 ± 1.2 cm/s versus 9.5 ± 1.5 cm/s, p < 0.001) and lateral mitral annulus (S' lateral: 6.4 ± 2.0 cm/s vs. 10.5 ± 2.1 cm/s, p < 0.001). The early diastolic velocity of the mitral annulus E' was significantly decreased in HCM, too (E' septal: 5.9 ± 2.2 cm/s vs. 13.1 ± 2.9 cm/s, p < 0.001; E' lateral: 8.2 ± 3.0 cm/s vs. 16.5 ± 3.4 cm/s, p < 0.001).

CONCLUSION

Tissue Doppler Imaging of the systolic and early diastolic velocity of the mitral annulus might be helpful as a promising additional method for the echocardiographic differentiation between pathological and physiologic left ventricular hypertrophy.

Proximal cerebral arteries develop myogenic responsiveness in heart failure via tumor necrosis factor-α-dependent activation of sphingosine-1-phosphate signaling

BACKGROUND

Heart failure is associated with neurological deficits, including cognitive dysfunction. However, the molecular mechanisms underlying reduced cerebral blood flow in the early stages of heart failure, particularly when blood pressure is minimally affected, are not known.

METHODS AND RESULTS

Using a myocardial infarction model in mice, we demonstrate a tumor necrosis factor-α (TNFα)-dependent enhancement of posterior cerebral artery tone that reduces cerebral blood flow before any overt changes in brain structure and function. TNFα expression is increased in mouse posterior cerebral artery smooth muscle cells at 6 weeks after myocardial infarction. Coordinately, isolated posterior cerebral arteries display augmented myogenic tone, which can be fully reversed in vitro by the competitive TNFα antagonist etanercept. TNFα mediates its effect via a sphingosine-1-phosphate (S1P)-dependent mechanism, requiring sphingosine kinase 1 and the S1P(2) receptor. In vivo, sphingosine kinase 1 deletion prevents and etanercept (2-week treatment initiated 6 weeks after myocardial infarction) reverses the reduction of cerebral blood flow, without improving cardiac function.

CONCLUSIONS

Cerebral artery vasoconstriction and decreased cerebral blood flow occur early in an animal model of heart failure; these perturbations are reversed by interrupting TNFα/S1P signaling. This signaling pathway may represent a potential therapeutic target to improve cognitive function in heart failure.

Tumor necrosis factor-α-mediated downregulation of the cystic fibrosis transmembrane conductance regulator drives pathological sphingosine-1-phosphate signaling in a mouse model of heart failure

BACKGROUND

Sphingosine-1-phosphate (S1P) signaling is a central regulator of resistance artery tone. Therefore, S1P levels need to be tightly controlled through the delicate interplay of its generating enzyme sphingosine kinase 1 and its functional antagonist S1P phosphohydrolase-1. The intracellular localization of S1P phosphohydrolase-1 necessitates the import of extracellular S1P into the intracellular compartment before its degradation. The present investigation proposes that the cystic fibrosis transmembrane conductance regulator transports extracellular S1P and hence modulates microvascular S1P signaling in health and disease.

METHODS AND RESULTS

In cultured murine vascular smooth muscle cells in vitro and isolated murine mesenteric and posterior cerebral resistance arteries ex vivo, the cystic fibrosis transmembrane conductance regulator (1) is critical for S1P uptake; (2) modulates S1P-dependent responses; and (3) is downregulated in vitro and in vivo by tumor necrosis factor-α, with significant functional consequences for S1P signaling and vascular tone. In heart failure, tumor necrosis factor-α downregulates the cystic fibrosis transmembrane conductance regulator across several organs, including the heart, lung, and brain, suggesting that it is a fundamental mechanism with implications for systemic S1P effects.

CONCLUSIONS

We identify the cystic fibrosis transmembrane conductance regulator as a critical regulatory site for S1P signaling; its tumor necrosis factor-α-dependent downregulation in heart failure underlies an enhancement in microvascular tone. This molecular mechanism potentially represents a novel and highly strategic therapeutic target for cardiovascular conditions involving inflammation.

[Stress-related alteration of urine compositions: idiopathic CaOx stone formers, patients with chronic inflammatory bowel disease (CIBD) and healthy controls]

BACKGROUND

Increased emotional stress in everyday life influences the way of living and metabolism of people living in developed countries. Contemporaneously, the incidence and prevalence of urolithiasis rises. Does a pathogenetically relevant relationship exist between chronic stress burden and permanently altered urinary composition?

PATIENTS AND METHODS

The influence of chronic stress burden on urine composition and risk of urinary calcium oxalate (CaOx) stone formation was, for the first time, comprehensively investigated in 29 healthy controls (CG), 29 idiopathic CaOx stone formers (SF) and 28 patients suffering from chronic inflammatory bowel disease (CIBD). After 4 days with standardized nutrition, 24-h urine was collected. Extensive urinalysis was performed and APCaOx index calculated. Evaluation of subjective stress level was carried out by using the standardized and well-established questionnaire Trierer Inventar zur Beurteilung von chronischem Stress (TICS). The concentration values of the urinary parameters as well as the APCaOx values were linearly correlated with the stress scores obtained from the different items of the TICS. A significance level p≤0.05 was considered to indicate statistical significance.

RESULTS

The mean APCaOx indices amounted to 0.8±0.3 in CG, 1.2±0.7 in SF and 1.9±1.2 in CIBD. The increased APCaOx in SF mainly results from relatively increased Ca and oxalate excretions, whereas in CIBD this also results from reduced urinary excretions of citrate and Mg as well as reduced 24-h urinary volumes. The calculation of linear correlation coefficients between a TICS stress dimension and a concentration value of a urinary parameter or APCaOx results in r values not exceeding 0.600. However, some of these correlations are statistically highly significant. In SF only one combination with Ca was observed, while in CIBD in contrast a number of combinations, in particular including Na, was obtained. In CG direct statistical relationships between stress burden and citrate as well as Mg exist. In this group, increased stress burden is associated with increased inhibitory potential to prevent CaOx stone formation.

CONCLUSION

In the investigated study groups, differently complex relationships between amount of stress burden and risk of CaOx stone formation were observed, however, without obvious physicochemical principle(s). In some individuals, stress can be associated with a significantly stress-related alteration of urinary composition towards increased CaOx stone formation risk. The results obtained from the CIBD group allow for the first time a conclusive link between emotional stress and inflammatory activity on the one hand and inflammatory activity and metabolic risk constellation of CaOx stone formation on the other hand.

Effects of a small acute subdural hematoma following traumatic brain injury on neuromonitoring, brain swelling and histology in pigs

An acute subdural hematoma (ASDH) induces pathomechanisms which worsen outcome after traumatic brain injury, even after a small hemorrhage. Synergistic effects of a small ASDH on brain damage are poorly understood, and were studied here using neuromonitoring for 10 h in an injury model of controlled cortical impact (CCI) and ASDH. Pigs (n = 32) were assigned to 4 groups: sham, CCI (2.5 m/s), ASDH (2 ml) and CCI + ASDH. Intracranial pressure was significantly increased above sham levels by all injuries with no difference between groups. CCI and ASDH reduced ptiO(2) by a maximum of 36 ± 9 and 26 ± 11%, respectively. The combination caused a 31 ± 11% drop. ASDH alone and in combination with CCI caused a significant elevation in extracellular glutamate, which remained increased longer for CCI + ASDH. The same two groups had significantly higher peak lactate levels compared to sham. Somatosensory evoked potential (SSEP) amplitude was persistently reduced by combined injury. These effects translated into significantly elevated brain water content and histological damage in all injury groups. Thus, combined injury had stronger effects on glutamate and SSEP when compared to CCI and ASDH, but no clear-cut synergistic effects of 2 ml ASDH on trauma were observed. We speculate that this was partially due to the CCI injury severity.