Search

This article belongs to the Special Issue Molecular Advances in Alzheimer's Disease., Reelin binds to the apolipoprotein E receptor apoER2 to activate an intracellular signaling cascade. The proteolytic cleavage of reelin follows receptor binding but can also occur independently of its binding to receptors. This study assesses whether reelin proteolytic fragments are differentially affected in the cerebrospinal fluid (CSF) of Alzheimer’s disease (AD) subjects. CSF reelin species were analyzed by Western blotting, employing antibodies against the N- and C-terminal domains. In AD patients, we found a decrease in the 420 kDa full-length reelin compared with controls. In these patients, we also found an increase in the N-terminal 310 kDa fragment resulting from the cleavage at the so-called C-t site, whereas the 180 kDa fragment originated from the N-t site remained unchanged. Regarding the C-terminal proteolytic fragments, the 100 kDa fragment resulting from the cleavage at the C-t site also displayed increased levels, whilst the one resulting from the N-t site, the 250 kDa fragment, decreased. We also detected the presence of an aberrant reelin species with a molecular mass of around 500 kDa present in AD samples (34 of 43 cases), while it was absent in the 14 control cases analyzed. These 500 kDa species were only immunoreactive to N-terminal antibodies. We validated the occurrence of these aberrant reelin species in an Aβ42-treated reelin-overexpressing cell model. When we compared the AD samples from APOE genotype subgroups, we only found minor differences in the levels of reelin fragments associated to the APOE genotype, but interestingly, the levels of fragments of apoER2 were lower in APOE ε4 carriers with regards to APOE ε3/ε3. The altered proportion of reelin/apoER2 fragments and the occurrence of reelin aberrant species suggest a complex regulation of the reelin signaling pathway, which results impaired in AD subjects., This work was supported by grants from the Fondo de Investigaciones Sanitarias (PI15/00665 and PI19-01359, co-funded by the Fondo Europeo de Desarrollo Regional, FEDER “Investing in your future”), CIBERNED (Instituto de Salud Carlos III, Spain), and the Direcció General de Ciència I Investigació, Generalitat Valenciana (AICO/2021/308). We also acknowledge the financial support from the Spanish Ministerio de Economía y Competitividad through the “Severo Ochoa” Program for Centers of Excellence in R&D (SEV-2017-0723). M.P.L. was supported by a BEFPI fellowship from the Generalitat Valenciana. H.Z. is a Wallenberg Scholar supported by grants from the Swedish Research Council (#2018-02532); the European Research Council (#681712); Swedish State Support for Clinical Research (#ALFGBG-720931); the Alzheimer Drug Discovery Foundation (ADDF), USA (#201809-2016862); the AD Strategic Fund and the Alzheimer’s Association (#ADSF-21-831376-C, #ADSF-21-831381-C, and #ADSF-21-831377-C); the Olav Thon Foundation; the Erling-Persson Family Foundation; Stiftelsen för Gamla Tjänarinnor; Hjärnfonden, Sweden (#FO2019-0228); the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie (grant agreement no. 860197; MIRIADE); and the UK Dementia Research Institute at UCL. K.B. is supported by the Swedish Research Council (#2017-00915); the Alzheimer Drug Discovery Foundation (ADDF), USA (#RDAPB-201809-2016615); the Swedish Alzheimer Foundation (#AF-742881); Hjärnfonden, Sweden (#FO2017-0243); the Swedish state under the agreement between the Swedish government and the County Councils; the ALF-agreement (#ALFGBG-715986); the European Union Joint Program for Neurodegenerative Disorders (JPND2019-466-236); the National Institute of Health (NIH), USA, (grant #1R01AG068398-01); and the Alzheimer’s Association 2021 Zenith Award (ZEN-21-848495).

We recently demonstrated that soluble forms of the amyloid-β protein precursor (sAβPP) assemble into multimeric complexes in cerebrospinal fluid (CSF), which contributes to the underestimation of specific sAβPP species when assessed by ELISA. To circumvent this issue, we analyzed by SDS-PAGE large fragments of sAβPP and their variants in the CSF from Alzheimer's disease (AD; n = 20) and control (n = 20) subjects, probing with specific antibodies against particular domains. Similar levels of sAβPPα and sAβPPβ protein were found in CSF samples from AD and controls, yet there appeared to be a shift in the balance of the soluble full-length AβPP (sAβPPf) species in AD samples, with a decrease in the proportion of the lower (∼100 kDa) band relative to the upper (∼120 kDa) band. Similar differences were observed in the contribution of the major KPI-immunoreactive AβPP species. CSF samples also displayed differences in the correlations of AβPP species with classical AD biomarkers, particularly with respect to the Aβ42 peptide. The differences reveal alterations that probably reflect pathophysiological changes in the brain., This study was funded in part by the EU BIOMARKAPD-Joint Programming on Neurodegenerative Diseases (JPND) project, by the Instituto de Salud Carlos III (ISCIII grants PI11/03026 to JSV, PI11/02425 and PI14/01126 to JF, PI11/03035 and PI14/1561 to AL, PI08/0036 and PI12/00013 to RSV, and PI11/03023 to JLM), co-financed by the Fondo Europeo de Desarrollo Regional, under the aegis of JPND, and through CIBERNED, ISCIII. This work was also supported by the Fundació Catalana de Síndrome de Down and by a “Marató TV3” grant (20141210 to JF) and a grant from the Griffols Foundation, and the Torsten Söderberg Foundation, Sweden (to KB).

Reelin is a glycoprotein associated with synaptic plasticity and neurotransmission. The malfunctioning of reelin signaling in the brain is likely to contribute to the pathogenesis of Alzheimer's disease (AD). Reelin binding to Apolipoprotein E receptor 2 (ApoER2) activates downstream signaling and induces the proteolytic cleavage of ApoER2, resulting in the generation of soluble fragments. To evaluate the efficiency of reelin signaling in AD, we have quantified the levels of reelin and soluble ectodomain fragments of ApoER2 (ectoApoER2) in the cerebrospinal fluid (CSF). CSF from sporadic AD patients (sAD; n = 14, age 54–83 years) had lower levels of ecto-ApoER2 (~31% reduction; p = .005) compared to those in the age-matched controls (n = 10, age 61–80), and a higher reelin/ecto-ApoER2 ratio. In contrast, autosomal dominant AD patients, carriers of PSEN1 mutations (ADAD; n = 7, age 31–49 years) had higher ecto-ApoER2 levels (~109% increment; p = .001) and a lower reelin/ecto-ApoER2 ratio than the non-mutation carriers from the same families (n = 7, age 25–47 years). Our data suggest that the levels of ecto-ApoER2 in CSF could be a suitable read-out of an impaired reelin signaling in AD, but also indicate differences between sAD and ADAD., This study was funded in part by the EU BIOMARKAPD-Joint Programming on Neurodegenerative Diseases (JPND) project, by the Instituto de Salud Carlos III (ISCIII grants PI11/03026 and PI15/00665 to JSV, PI08/0036 and PI12/00013 to RSV, and PI11/03023 to JLM), by the Direcció General d'Universitat, Investigació i Ciència, GVA (AICO/2018/090 to JSV), co-financed by the Fondo Europeo de Desarrollo Regional (FEDER, “Investing in your future”), and through CIBERNED, ISCIII.

The β-site amyloid precursor protein cleaving enzyme 1 (BACE1) is the main brain β-secretase responsible for the amyloidogenic processing of the amyloid precursor protein (APP). Previous studies have suggested that cerebrospinal fluid (CSF) β-secretase activity may be a candidate diagnostic biomarker for Alzheimer’s disease (AD), but biochemical characterization of BACE1 protein in CSF is needed. CSF samples from 19 AD patients and 19 age-matched non-AD controls (n = 19) were classified according to their Aβ42, total tau, and P-tau CSF biomarker levels. We found that β-secretase activity was higher in the CSF of AD subjects than in that of the controls. We found that the majority of the β-secretase activity in the CSF, measured using a peptide substrate homologous to the BACE1 cleavage site, was not inhibited by specific BACE1 inhibitors. We defined enzymatic activity attributable specifically to BACE1 as the activity that was blocked by the specific inhibitors, which is still higher in AD subjects. BACE1 protein levels were characterized by lectin binding, immunoprecipitation, blue native-PAGE, and western blotting using antibodies against specific protein domains. BACE1 was found to be present in human CSF as a mature form of ~ 70 kDa that probably comprised truncated and full-length species, and also as an immature form of ~ 50 kDa that retains the prodomain. CSF-BACE1 was found to assemble into hetero-complexes containing distinct species. Immunoblotting with an antibody against the C-terminus of BACE1 revealed significantly higher levels of the 70-kDa full-length BACE1, while the 50 kDa immature form remained unaltered. When the 70-kDa species was probed with an antibody against the N-terminus of BACE1 (which does not discriminate between truncated and full-length forms), no increase in immunoreactivity was observed, suggesting that truncated forms of BACE1 do not increase in AD. In conclusion, the complexity of BACE1 species in CSF has to be taken into consideration when determining BACE1 activity and protein levels in CSF as biomarkers of AD., This study was funded in part by the Direcció General d’Universitat, Investigació i Ciència, GVA (AICO/2018/090), by the EU BIOMARKAPD-Joint Programme on Neurodegenerative Diseases (JPND) and the Instituto de Salud Carlos III (ISCIII grant PI11/03026), by the ISCIII (PI15/00665), co-financed by the Fondo Europeo de Desarrollo Regional under the aegis of JPND), and through CIBERNED, ISCIII (FEDER, “Investing in your future”). HZ is a Wallenberg Academy Fellow supported by grants from the European Research Council, the Swedish Research Council and the UK Dementia Research Institute at UCL. KB holds the Torsten Söderberg Professorship in Medicine at the Royal Swedish Academy of Sciences, and is supported by the Swedish Research Council (#2017-00915), the Swedish Alzheimer Foundation (#AF-742881), Hjärnfonden, Sweden (#FO2017-0243), and a grant (#ALFGBG-715986) from the Swedish state under the agreement between the Swedish government and the County Councils, the ALF-agreement.

ErbB4 is a transmembrane receptor tyrosine kinase that binds to neuregulins to activate signaling. Proteolytic cleavage of ErbB4 results in release of soluble fragments of ErbB4 into the interstitial fluid. Disruption of the neuregulin-ErbB4 pathway has been suggested to be involved in the pathogenesis of amyotrophic lateral sclerosis (ALS). This study assesses whether soluble proteolytic fragments of the ErbB4 ectodomain (ecto-ErbB4) can be detected in cerebrospinal fluid (CSF) and plasma, and if the levels are altered in ALS. Immunoprecipitation combined with mass spectrometry or western blotting analyses confirmed the presence of ecto-ErbB4 in human CSF. Several anti-ErbB4-reactive bands, including a 55 kDa fragment, were detected in CSF. The bands were generated in the presence of neuregulin-1 (Nrg1) and were absent in plasma from ErbB4 knockout mice. Ecto-ErbB4 levels were decreased in CSF from ALS patients (n = 20) and ALS with concomitant frontotemporal dementia patients (n = 10), compared to age-matched controls (n = 13). A similar decrease was found for the short ecto-ErbB4 fragments in plasma of the same subjects. Likewise, the 55-kDa ecto-ErbB4 fragments were decreased in the plasma of the two transgenic mouse models of ALS (SOD1G93A and TDP-43A315T). Intracellular ErbB4 fragments were decreased in the frontal cortex from SOD1G93A mice, indicating a reduction in Nrg-dependent induction of ErbB4 proteolytic processing, and suggesting impaired signaling. Accordingly, overexpression of Nrg1 induced by an adeno-associated viral vector increased the levels of the ecto-ErbB4 fragment in the SOD1G93A mice. We conclude that the determination of circulating ecto-ErbB4 fragments could be a tool to evaluate the impairment of the ErbB4 pathway and may be a useful biomarker in ALS., This work was supported by grants from the Fondo de Investigaciones Sanitarias (PI15/00665 to JSV and PI15/01618 to RRG), cooperative project 2015-01 from CIBERNED (Instituto de Salud Carlos III, Spain) to XN and JSV, all co-funded by the Fondo Europeo de Desarrollo Regional (FEDER), Unión Europea, “Una manera de hacer Europa”; grants TV3201428-10 to XN and 201437 to RRG of Fundació La Marato-TV3; and grant #20289 of AFM-Telethon to XN. HZ is a Wallenberg Academy Fellow and is supported by grants from the Swedish and European Research Councils and the UK Dementia Research Institute at UCL. KB holds the Torsten Söderberg Professorship in Medicine at the Royal Swedish Academy of Sciences. We also acknowledge financial support from the Spanish Ministerio de Economía y Competitividad, through the “Severo Ochoa” Programme for Centres of Excellence in R&D (SEV-2017-0723).

In the continuing search for proteins that play a role in Alzheimer's disease (AD) and that are related to the pathological hallmarks, those that influence cognitive function and that constitute potential therapeutic targets deserve special interest. Reelin is a signaling protein that is involved in a cascade of cytoplasmic events that control tau phosphorylation and that regulate synaptic neurotransmission, plasticity, and memory. Both Reelin expression and glycosylation are modulated by amyloid-β (Aβ), suggesting that the activity of Reelin could be affected in AD and hence, its possible influence on this pathology should be taken into consideration. The levels of Reelin in the brain of AD patients appear to be altered and interestingly, disrupted Reelin signaling is associated with increased tau phosphorylation as well as with amyloid-β protein precursor processing. We discuss here the somewhat contradictory data regarding Reelin levels in AD and we evaluate the processing of the Reelin receptor, ApoER2, and other downstream events, such as the phosphorylation of the intracellular adapter Dab1. Together with brain Reelin levels, these changes may represent a relevant read-out of Reelin signaling in the human brain.

Although aggressive fluid therapy during the first days of hospitalization is recommended by most guidelines and reviews on acute pancreatitis (AP), this recommendation is not supported by any direct evidence. We aimed to evaluate the association between the amount of fluid administered during the initial 24 h of hospitalization and the incidence of organ failure (OF), local complications, and mortality.This was a prospective cohort study. We included consecutive adult patients admitted with AP. Local complications and OF were defined according to the Atlanta Classification. Persistent OF was defined as OF of48-h duration. Patients were divided into three groups according to the amount of fluid administered during the initial 24 h: group A:3.1 l (less than the first quartile), group B: 3.1-4.1 l (between the first and third quartiles), and group C:4.1 l (more than the third quartile).A total of 247 patients were analyzed. Administration of4.1 l during the initial 24 h was significantly and independently associated with persistent OF, acute collections, respiratory insufficiency, and renal insufficiency. Administration of3.1 l during the initial 24 h was not associated with OF, local complications, or mortality. Patients who received between 3.1 and 4.1 l during the initial 24 h had an excellent outcome.In our study, administration of a small amount of fluid during the initial 24 h was not associated with a poor outcome. The need for a great amount of fluid during the initial 24 h was associated with a poor outcome; therefore, this group of patients must be carefully monitored.

Persistent and multiple organ failure (POF and MOF) are predictive of death in acute pancreatitis (AP). Local complications without organ failure are associated with morbidity but a low risk of mortality.To design a three-category classification of AP severity and to compare it with the Atlanta Classification (AC) in terms of morbidity and mortality.Severe AP was defined as death, POF (48 h) or MOF. Moderate AP was defined as the presence of acute collections and/or pancreatic necrosis. Mild AP was defined by exclusion. We compared this classification with AC in 144 episodes of AP.In the three-category classification, severe AP was associated with significantly more frequent intensive care unit admission, invasive treatment and mortality than moderate and mild AP (p0.01). Severe AP patients required longer hospital stay and more nutritional support than mild AP patients (p0.01). Patients with moderate AP had significantly longer hospital stay and more need for nutritional support than patients with mild AP (p0.01). Five patients died, all of them with MOF and/or POF.A three-category classification distinguishes three homogeneous groups of severity.

In chromaffin cells, SNARE proteins, forming the basic exocytotic machinery are present in membrane clusters of 500-600 nm in diameter. These microdomains containing both SNAP-25 and syntaxin-1 are dynamic and the expression of altered forms of SNAREs modifies not only their motion but also the mobility of the associated granules. It is also clear that SNARE microdomain location defines the place for individual vesicle fusion and that the alteration of cluster dynamics affects the fusion process itself. Interestingly, these SNARE patches colocalize with the borders of F-actin cages forming the cytoskeletal cortical network, and these borders also contain clusters of L- and P/Q type calcium channels. The organization of the secretory machinery in association with the borders of cytoskeletal cages seems to be an effective way to promote fast coupling between calcium entry and catecholamine release as demonstrated with the use of mathematical secretory models.

Adrenomedullary chromaffin cells represent an excellent model to study the molecular events linked to exocytosis, because they use the same type of SNAREs for vesicle docking and fusion as neurons. In these cells, both in the intact tissue and in isolated cells in culture, syntaxin-1 and SNAP-25 are present in the plasmalemma unevenly distributed in patches, even when exogenous t-SNAREs are expressed. In fact, the expression of SNAP-25 fused to green fluorescent protein has been useful to study the movement of these clusters by total internal reflection fluorescent microscopy. These microdomains move little in the plasma membrane plane but they undertake relatively large displacements of 100 nm in the axis perpendicular to the membrane. Movement in either axis is dependent on molecular interactions within the t-SNARE complex and indeed, clusters formed by recombinant SNAP-25 Δ9, the product of Botulinum neurotoxin A cleavage, undergo larger displacement. Interestingly, altering the movement of t-SNARE clusters also influences the mobility of the chromaffin vesicles associated with these t-SNAREs. Furthermore, highly mobile vesicles associated with the clusters formed by SNAP-25 Δ9 present a low probability of exocytosis and also slower fusion kinetics. Finally, we discuss some of the factors that could influence the movement of t-SNARE clusters and how these dynamics may influence the mobility and the fusion properties of the vesicles in the vicinity of active sites.

Background: Soluble fragments of the amyloid precursor protein (APP) generated by α- and β-secretases, sAPPα and sAPPβ, have been postulated as promising new cerebrospinal fluid (CSF) biomarkers for the clinical diagnosis of Alzheimer’s disease (AD). However, the capacity of these soluble proteins to assemble has not been explored and could be relevant. Our aim is to characterize possible sAPP oligomers that could contribute to the quantification of sAPPα and sAPPβ in CSF by ELISA, as well as to characterize the possible presence of soluble full-length APP (sAPPf)., Results: We employed co-immunoprecipitation, native polyacrylamide gel electrophoresis and ultracentrifugation in sucrose density gradients to characterize sAPP oligomers in CSF. We have characterized the presence of sAPPf in CSF from NDC and AD subjects and demonstrated that all forms, including sAPPα and sAPPβ, are capable of assembling into heteromers, which differ from brain APP membrane-dimers. We measured sAPPf, sAPPα and sAPPβ by ELISA in CSF samples from AD (n = 13) and non-disease subjects (NDC, n = 13) before and after immunoprecipitation with antibodies against the C-terminal APP or against sAPPβ. We demonstrated that these sAPP heteromers participate in the quantification of sAPPα and sAPPβ by ELISA. Immunoprecipitation with a C-terminal antibody to remove sAPPf reduced by ~30% the determinations of sAPPα and sAPPβ by ELISA, whereas immunoprecipitation with an APPβ antibody reduced by ~80% the determination of sAPPf and sAPPα., Conclusions: The presence of sAPPf and sAPP heteromers should be taken into consideration when exploring the levels of sAPPα and sAPPβ as potential CSF biomarkers., This study was funded in part by the EU BIOMARKAPD-Joint Programming on Neurodegenerative Diseases (JPND) project. This project is supported through the Instituto de Salud Carlos III (ISCIII; grants PI11/03026 to JSV and PI11/03023 to JLM) under the aegis of JPND, and through CIBERNED, ISC-III. We also acknowledge the support for the publication fee to the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).

Chromaffin cell catecholamines are released when specialized secretory vesicles undergo exocytotic membrane fusion. Evidence indicates that vesicle supply and fusion are controlled by the activity of the cortical F-actin-myosin II network. To study in detail cell cortex and vesicle interactions, we use fluorescent labeling with GFP-lifeact and acidotropic dyes in confocal and evanescent wave microscopy. These techniques provide structural details and dynamic images of chromaffin granules caged in a complex cortical structure. Both the movement of cortical structures and granule motion appear to be linked, and this motion can be restricted by the myosin II-specific inhibitor, blebbistatin, and the F-actin stabilizer, jasplakinolide. These treatments also affect the position of the vesicles in relation to the plasma membrane, increasing the distance between them and the fusion sites. Consequently, we observed slower single vesicle fusion kinetics in treated cells after neutralization of acridine orange-loaded granules during exocytosis. Increasing the distance between the granules and the fusion sites appears to be linked to the retraction of the F-actin cytoskeleton when treated with jasplakinolide. Thus, F-actin-myosin II inhibitors appear to slow granule fusion kinetics by altering the position of vesicles after relaxation of the cortical network., This work was supported by grants from the Spanish Ministry of Science and Innovation (MICINN, BFU2008-00731, and BFU2011-25095) and the Generalitat Valenciana (ACOMP2011/090) to LMG. IL and CT were recipients of fellowships from the Spanish Ministry of Education and Science (MEC).

We have studied how the F-actin cytoskeleton is involved in establishing the heterogeneous intracellular Ca2+ levels ([Ca2+] i) and in the organization of the exocytotic machinery in cultured bovine chromaffin cells. Simultaneous confocal visualization of [Ca 2+]i and transmitted light studies of the cytoskeleton showed that, following cell stimulation, the maximal signal from the Ca 2+-sensitive fluorescent dye Fluo-3 was in the empty cytosolic spaces left by cytoskeletal cages. This was mostly due to the accumulation of the dye in spaces devoid of cytoskeletal components, as shown by the use of alternative Ca2+-insensitive fluorescent cytosolic markers. In addition to affecting the distribution of such compounds in the cytosol, the cytoskeleton influenced the location of L- and P-Q-type Ca2+ channel clusters, which were associated with the borders of cytoskeletal cages in resting and stimulated cells. Indeed, syntaxin-1 and synaptotagmin-1, which are components of the secretory machinery, were present in the same location. Furthermore, granule exocytosis took place at these sites, indicating that the organization of the F-actin cytoskeletal cortex shapes the preferential sites for secretion by associating the secretory machinery with preferential sites for Ca 2+ entry. The influence of this cortical organization on the propagation of [Ca2+]i can be modelled, illustrating how it serves to define rapid exocytosis., This work was supported by grants from the Spanish Ministry of Education and Culture (MEC, MICINN, BFU2005-02154/BFI and BFU2008-00731) and the Generalitat Valenciana (ACOMP06/036) to L.M.G.; the Spanish Ministry of Education and Culture (BFU2007-67607) and AN (BFU2008-01492) to I.Q.; and the Fundación BBVA and I-MATH project C3-0136 to A.G. and J.S. C.J.T.-H. and I.L.-F. were recipients of fellowships from the MICINN (Spain). V.G-V. thanks CONACyT for its financial support of her PhD scholarship. We also acknowledge the financial support received from the CONSOLIDER programme (CSD07-00023) and CIBERDEM (Instituto de Salud Carlos III).

Introduction: Angiopoietin-2 (Ang-2) is a vascular mediator associated with increased endothelial permeability. It has been described that Ang-2 levels are associated with severity of acute pancreatitis (AP). We hypothesize that Ang-2 may be associated with fluid sequestration (FS), thus it may be an early marker of increased fluid requirements. Aims: Our main aim was to investigate the association between serum Ang-2 levels and FS. Our secondary aimwas to investigate the relationship between serum Ang-2 levels and outcome. Patients & methods: Retrospective analysis of a prospective clinical database and banked serum (obtained in the first 24h of admission) of consecutive patients admitted with AP. Ang-2 levels were measured by enzyme-linked immunosorbent assay. FS was categorized according to percentiles of FS (water balance) in Group A: p75 (>3.8L). Results: We included 123 episodes of AP, 52.8% females, 63.4% gallstone AP. Median (p25-p75) Ang-levels (pg/mL) were 3752 (2486-4384) in group A, 4685 (3459-6057) in group B and 4928 (3071-6119) in group C, p < 0.05. Ang-2 levels (pg/mL) were significantly (p

Angiopoietin-2, a Regulator of Vascular Permeability in Inflammation, is Associated With Persistent Organ Failure in Patients With Acute Pancreatitis From the United States and Germany David C. Whitcomb, Venkata Muddana, Christopher J. Langmead, Frank D. Houghton, Annett Guenther, Patricia K. Eagon, Julia Mayerle, Ali Aghdassi, Frank U. Weiss, Janette Lamb, Gilles Clermont, Markus M. Lerch, Georgios I. Papachristou

To study the activation of pancreatic and pulmonary mast cells and the effect of mast cell inhibition on the activation of peritoneal and alveolar macrophages during acute pancreatitis. METHODS: Pancreatitis was induced by intraductal infusion of 5% sodium taurodeoxycholate in rats. The mast cell inhibitor cromolyn was administered intraperitoneally (i.p.) 30 min before pancreatitis induction. The pancreatic and pulmonary tissue damage was evaluated histologically and mast cells and their state of activation were evaluated. Peritoneal and alveolar macrophages were obtained and the expression of tumor necrosis factor α was determined. Myeloperoxidase activity was measured to evaluate the effect of mast cell inhibition on the progression of the inflammatory process. Finally, the effect of plasma on cultured mast cells or macrophages was evaluated in vitro. RESULTS: The mast cell stabilizer significantly reduced inflammation in the pancreas and lung and the activation of alveolar macrophages but had no effect on peritoneal macrophages. Mast cell degranulation was observed in the pancreas during pancreatitis but no changes were observed in the lung. Plasma from rats with pancreatitis could activate alveolar macrophages but did not induce degranulation of mast cells in vitro. CONCLUSION: Pancreatic mast cells play an important role in triggering the local and systemic inflammatory response in the early stages of acute pancreatitis. In contrast, lung mast cells are not directly involved in the inflammatory response related to pancreatic damage., Supported by The Project SAF2006-08449 and a grant from Fundación para la Investigación del Hospital General Universitario de Alicante; Inmaculada Lopez-Font has a Juan de la Cierva contract supported by the Spanish Ministry of Science and Innovation.

Introduccion La neoplasia mucinosa papilar intraductal (NMPI) es un tumor pancreatico productor de mucina que crece en el sistema ductal. Objetivos Describir las caracteristicas clinicas de los casos de NMPI diagnosticados en nuestro centro. Pacientes y metodos Estudio retrospectivo de pacientes diagnosticados de NMPI en el Hospital General Universitario de Alicante entre 2005 y 2008. Resultados Se diagnosticaron 9 pacientes, 6 (66,7%) varones. La edad al diagnostico fue 70±10 anos (rango 55-81). En 8 (88,9%) pacientes se sospecho la neoplasia por imagen tipica en TAC, en 1 (11,1%) paciente se sospecho por ecoendoscopia (moco en papila). En 5 (55,6%) de los casos la NMPI era de rama periferica y en 4 (44,4%) de ducto principal. La clinica de presentacion mas frecuente fue pancreatitis aguda: 5 (55,6%) pacientes, seguida de dolor abdominal en 2 (22,2%), diagnostico casual en prueba de imagen en 1 (11,1%) y sindrome constitucional en 1 (11,1%) paciente. En 2 (22,2%) casos la NMPI se asociaba a calcificaciones pancreaticas por pancreatitis cronica obstructiva. El diagnostico definitivo en 8 (88,9%) pacientes se realizo por ecoendoscopia (citologia positiva en 5, en el resto con citologia negativa: presencia de moco en 2 pacientes y CEA elevado con lesion tipica en 1). En 1 (11,1%) paciente se diagnostico por moco en PAAF percutanea. En total se objetivo moco en la puncion o en papila en 5 (55,6%) pacientes. La histologia fue adenoma en 5 (55,6%) casos, borderline en 3 (33,3%, todos ellos de ducto principal) y desconocida en 1 (11,1%). El tratamiento fue quirurgico en 4 (44,4%) pacientes (duodenopancreatectomia cefalica en todos ellos). En 3 (33,3%) de ellos la indicacion fue NMPI sintomatica (pancreatitis aguda o dolor abdominal) y en 1 (11,1%) por NMPI de ducto principal. En 2 casos con NMPI borderline no se realizo cirugia por rechazo del paciente asociado a edad elevada. No hubo casos de neoplasia invasiva ni mortalidad. Conclusiones La presentacion mas frecuente de la NMPI es la pancreatitis aguda. El TAC es la prueba que suele sugerir el diagnostico y la ecoendoscopia la tecnica que lo confirma. El analisis del liquido es eficaz en el diagnostico. La histologia mas frecuente es adenoma. La NMPI de ducto principal es mas agresiva histologicamente.

Introduccion El sistema BISAP se ha descrito y validado recientemente como predictor de mortalidad al ingreso por pancreatitis aguda (PA) en un estudio poblacional. Consta de 5 elementos de facil determinacion, cada uno de los cuales tiene el valor de 1 punto: nitrogeno ureico en sangre > 25 mg/dl, alteracion de estado mental, sindrome de respuesta inflamatoria sistemica, edad mayor de 60 anos y presencia de derrame pleural. Su principal ventaja es que su calculo es sencillo, en contraposicion al sistema APACHE II que tambien ha mostrado valor pronostico en el momento del ingreso hospitalario. Objetivos Comprobar la utilidad del sistema BISAP al ingreso en la prediccion de complicaciones locales, sistemicas, mortalidad y gravedad de PA segun criterios de Atlanta y compararlo con APACHE II. Pacientes y metodos Estudio de cohortes retrospectivo. Se analizo una base de datos completada de forma prospectiva que incluia todo paciente con pancreatitis aguda ingresado en nuestro servicio desde enero a noviembre de 2008. Resultados Se analizaron 98 pacientes, 23% con PA grave. La mortalidad fue 5,1%. La etiologia fue biliar en 46,9%, alcohol 14,3%, idiopatica 16,3% y otras causas en 22,5%. De los 5 pacientes que fallecieron 2 mostraron en BISAP 1 punto, 2 de ellos 2 puntos y en 1 caso 3 puntos. No se encontro asociacion estadisticamente significativa entre BISAP y presencia de colecciones agudas, pseudoquistes, necrosis, fallo organico, gravedad ni mortalidad. APACHE II al ingreso se asocio a mortalidad (9,2±5,6 vs 6,1±3, p Conclusiones En nuestra muestra el sistema BISAP al ingreso no identifica eficazmente los casos fatales, ni predice las complicaciones locales o el fallo organico en la pancreatitis aguda. El APACHE II al ingreso se asocio de forma significativa a mortalidad, fallo organico y gravedad.

This study assesses whether C-terminal fragments (CTF) of the amyloid precursor protein (APP) are present in cerebrospinal fluid (CSF) and their potential as biomarkers for Alzheimer’s disease (AD). Immunoprecipitation and simultaneous assay by Western blotting using multiplex fluorescence imaging with specific antibodies against particular domains served to characterize CTFs of APP in human CSF. We demonstrate that APP-CTFs are detectable in human CSF, being the most abundant a 25-kDa fragment, probably resulting from proteolytic processing by η-secretase. The level of the 25-kDa APP-CTF was evaluated in three independent CSF sample sets of patients and controls. The CSF level of this 25-kDa CTF is higher in subjects with autosomal dominant AD linked to PSEN1 mutations, in demented Down syndrome individuals and in sporadic AD subjects compared to age-matched controls. Our data suggest that APP-CTF could be a potential diagnostic biomarker for AD., This study was funded in part by the EU BIOMARKAPD-Joint Programming on Neurodegenerative Diseases (JPND) project, by the Instituto de Salud Carlos III (ISCIII grants PI11/03026 and PI15/00665 to JSV, PI11/02425 and PI14/01126 to JF, PI11/03035 and PI14/1561 to AL, PI08/0036 and PI12/00013 to RSV, and PI11/03023 to JLM), co-financed by the Fondo Europeo de Desarrollo Regional, under the aegis of JPND, and through CIBERNED, ISCIII. This work was also supported by the Fundació Catalana de Síndrome de Down, by a “Marató TV3” grant (20141210) and a grant from the Griffols Foundation, Spain (to JF); and the Torsten Söderberg Foundation, Sweden (to KB). JSV also acknowledges financial support from the Spanish Ministerio de Economía y Competitividad, through the “Severo Ochoa” Programme for Centres of Excellence in R&D (SEV- 2013-0317).