DHA Selectively Protects SAMP-8-Associated Cognitive Deficits Through Inhibition of JNK.

A potential role of marine n-3 polyunsaturated fatty acids (ω-3 PUFAs) has been suggested in memory, learning, and cognitive processes. Therefore, ω-3 PUFAs might be a promising treatment option, albeit controversial, for Alzheimer's disease (AD). Among the different mechanisms that have been proposed as responsible for the beneficial effects of ω-3 PUFAs, inhibition of JNK stands as a particularly interesting candidate. In the present work, it has been studied whether the administration of two different PUFAs (docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)) and a DHA-derived specialized pro-resolving lipid mediator (MaR1) is able to reverse cognitive deficits in the senescence-accelerated mouse prone 8 (SAMP8) mouse model of sporadic AD. The novel object recognition test (NORT) test showed that recognition memory was significantly impaired in SAMP8 mice, as shown by a significantly decreased discrimination index that was reversed by MaR1 and DHA. In the retention phase of the Morris water maze (MWM) task, SAMP8 mice showed memory deficit that only DHA treatment was able to reverse. pJNK levels were significantly increased in the hippocampus of SAMP8 mice compared to SAMR1 mice, and only DHA treatment was able to significantly reverse these increased pJNK levels. Similar results were found when measuring c-Jun, the main JNK substrate. Consequently to the increases in tau phosphorylation after increased pJNK, it was checked that tau phosphorylation (PHF-1) was increased in SAMP mice, and this effect was reversed after DHA treatment. Altogether, DHA could represent a new approach for the treatment of AD through JNK inhibition.

Small GSK-3 Inhibitor Shows Efficacy in a Motor Neuron Disease Murine Model Modulating Autophagy.

Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron degenerative disease that has no effective treatment up to date. Drug discovery tasks have been hampered due to the lack of knowledge in its molecular etiology together with the limited animal models for research. Recently, a motor neuron disease animal model has been developed using ß-N-methylamino-L-alanine (L-BMAA), a neurotoxic amino acid related to the appearing of ALS. In the present work, the neuroprotective role of VP2.51, a small heterocyclic GSK-3 inhibitor, is analysed in this novel murine model together with the analysis of autophagy. VP2.51 daily administration for two weeks, starting the first day after L-BMAA treatment, leads to total recovery of neurological symptoms and prevents the activation of autophagic processes in rats. These results show that the L-BMAA murine model can be used to test the efficacy of new drugs. In addition, the results confirm the therapeutic potential of GSK-3 inhibitors, and specially VP2.51, for the disease-modifying future treatment of motor neuron disorders like ALS.

Morphometric and neurochemical alterations found in l-BMAA treated rats.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive muscle paralysis that reflects the motoneurons' degeneration. Several studies support the relationship between ß-N-methylamino-l-alanine (l-BMAA), a neurotoxic amino acid produced by cyanobacteria and diatoms, and the sporadic occurrence of ALS and other neurodegenerative diseases. Therefore, the study of its neurotoxicity mechanisms has assumed great relevance in recent years. Recently, our research team has proposed a sporadic ALS animal model by l-BMAA administration in rats, which displays many pathophysiological features of human ALS. In this paper, we deepen the characterization of this model corroborating the occurrence of alterations present in ALS patients such as decreased muscle volume, thinning of the motor cortex, enlarged brain's lateral ventricles, and alteration of both bulbar nuclei and neurotransmitters' levels. Therefore, we conclude that l-BMAA treated rats could be a good model which mimics degenerative features that ALS causes in humans.

Preparation and impact of multiple (water-in-oil-in-water) emulsions in meat systems.

The aim of this paper was to prepare and characterise multiple emulsions and assess their utility as pork backfat replacers in meat gel/emulsion model systems. In order to improve the fat content (in quantitative and qualitative terms) pork backfat was replaced by a water-in-oil-in-water emulsion (W1/O/W2) prepared with olive oil (as lipid phase), polyglycerol ester of polyricinoleic acid (PGPR) as a lipophilic emulsifier, and sodium caseinate (SC) and whey protein concentrate (WP) as hydrophilic emulsifiers. The emulsion properties (particle size and distribution, stability, microstructure) and meat model system characteristics (composition, texture, fat and water binding properties, and colour) of the W1/O/W2, as affected by reformulation, were evaluated. Multiple emulsions showed a well-defined monomodal distribution. Freshly prepared multiple emulsions showed good thermal stability (better using SC) with no creaming. The meat systems had good water and fat binding properties irrespective of formulation. The effect on texture by replacement of pork backfat by W1/O/W2 emulsions generally depends on the type of double emulsion (associated with the hydrophilic emulsifier used in its formulation) and the fat level in the meat system.

ß-N-methylamino-l-alanine causes neurological and pathological phenotypes mimicking Amyotrophic Lateral Sclerosis (ALS): the first step towards an experimental model for sporadic ALS.

ß-N-methylamino-l-alanine (L-BMAA) is a neurotoxic amino acid that has been related to various neurodegenerative diseases. The aim of this work was to analyze the biotoxicity produced by L-BMAA in vivo in rats, trying to elucidate its physiopathological mechanisms and to search for analogies between the found effects and pathologies like Amyotrophic Lateral Sclerosis (ALS). Our data demonstrated that the neurotoxic effects in vivo were dosage-dependent. For evaluating the state of the animals, a neurological evaluation scale was developed as well as a set of functional tests. Ultrastructural cell analysis of spinal motoneurons has revealed alterations both in endoplasmic reticulum and mitochondria. Since GSK3ß could play a role in some neuropathological processes, we analyzed the alterations occurring in GSK3ß levels in L-BMAA treated rats, we have observed an increase in the active form of GSK3ß levels in lumbar spinal cord and motor cerebral cortex. On the other hand, (TAR)-DNA-binding protein 43 (TDP-43) increased in L-BMAA treated animals. Our results indicated that N-acetylaspartate (NAA) declined in animals treated with L-BMAA, and the ratio of N-acetylaspartate/choline (NAA/Cho), N-acetylaspartate/creatine (NAA/Cr) and N-acetylaspartate/choline+creatine (NAA/Cho+Cr) tended to decrease in lumbar spinal cord and motor cortex. This project offers some encouraging results that could help establishing the progress in the development of an animal model of sporadic ALS and L-BMAA could be a useful tool for this purpose.

Mitochondria, motor neurons and aging.

While the role of mitochondria in aging has been well characterized, their involvement in motor neuron aging remains poorly understood. Thus, we performed an exhaustive ultrastructural study of mitochondria in motor neurons from aged rats that revealed dramatic alterations in the mitochondria of axon terminals at neuromuscular junctions, characterized by swelling, mitochondrial fusion and the presence of megamitochondria. These alterations were not observed in ventral horn motor neurons in the spinal cord of aged rats, which were only altered by the appearance of electron-dense bodies in the dilated matrix cristae. Using X-ray microanalytical techniques we demonstrated the presence of calcium in these bodies, suggesting Ca(2+) overload. Moreover, in motor neurons from aged rats, cytochrome c and activated caspase 3 were detected in the cytoplasm of axon terminals at neuromuscular junctions, factors implicated in the apoptosis. Active caspase 3 was also found in the nucleus, soma and axons of aged alpha motor neuron neurons, where it mainly associated with microtubules. The colocalization of dynein and cleaved caspase 3 in neuromuscular junctions is strongly suggestive of the retrograde transport of apoptotic factors to the soma. These results are consistent with the early stages of degeneration in neuromuscular junctions during aging, which is followed by dying back. Given that aging is a key risk factor for neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS), the identification of age-related motor neuron degeneration initiated at the distal end of the axon may provide a new therapeutic target for early intervention.

ß-N-methylamino-L-alanine induces changes in both GSK3 and TDP-43 in human neuroblastoma.

ß-N-methylamino-L-alanine (L-BMAA) is a neurotoxic amino acid produced by most cyanobacteria, which are extensively distributed in different environments all over the world. L-BMAA has been linked to a variety of neurodegenerative diseases. This work aims to analyze the toxicological action of L-BMAA related to alterations observed in different neurodegenerative illness as Alzheimer disease and amyotrophic lateral sclerosis. Our results demonstrate that neuroblastoma cells treated with L-BMAA show an increase in glycogen synthase kinase 3 ß (GSk3ß) and induce accumulation of TAR DNA-binding protein 43 (TDP-43) truncated forms (C-terminal fragments), phosphorylated  and high molecular weight forms of TDP-43, that appears frequently in some neurodegenerative diseases.

Mineralocorticoid receptor activation induces insulin resistance through c-Jun N-terminal kinases in response to chronic corticosterone: cognitive implications.

It is becoming evident that chronic exposure to glucocorticoids might not only result in insulin resistance or cognitive deficits, but also is considered as a risk factor for pathologies such as depression or Alzheimer's disease. In the present study, in vivo experiments using a non-invasive method of chronic administration of corticosterone in drinking water demonstrated that chronic corticosterone administration led to cognitive impairment in the novel object recognition test and insulin resistance, as shown by significant increases in plasma insulin levels and the homeostatic model assessment index, and decreased insulin receptor phosphorylation. Corticosterone treatment induced an increased expression of stress-activated c-Jun N-terminal kinase (JNK) in the hippocampus, accompanied by decreases in glycogen synthase kinase 3ß, increases in pTau levels and increased neuronal cell death (caspase-3 activity). All these effects were reversed by the administration of a JNK1 inhibitor or by the mineralocorticoid receptor antagonist spironolactone. It is suggested that the mineralocorticoid receptors and JNK-mediated pathways are involved in the interaction of glucocorticoid-insulin resistance and the development of relevant cellular processes for Alzheimer's disease.

Healthier oils stabilized in konjac matrix as fat replacers in n-3 PUFA enriched frankfurters.

Nutritional, sensory and technological properties of frankfurters as affected by reformulation processes designed to reduce fat content and improve fatty acid profile were investigated. Healthier oils stabilized in oil in water emulsion or in konjac matrix gel were used as fat replacers. Results showed that improved fat content by the replacement of pork backfat with konjac gel and by the addition of healthier oils stabilized by various different systems, both resulted in products with very similar characteristics. From a nutritional standpoint, reformulated frankfurters with konjac gel and/or added a healthier oil combination may claim "reduced fat content" and/or "high omega 3 fatty acid content" according to European Regulation, since they could contain less than 30% of the fat in the reference product and more than 0.6 g of ALA/100 g and more than 80 mg of the sum of EPA plus DHA per 100 g, respectively. Chill storage over 40days generally had little effect on the technological characteristics of frankfurters.

Stress-induced anhedonia is associated with an increase in Alzheimer's disease-related markers.

BACKGROUND AND PURPOSE: Stress is believed to be associated with the development of neuropsychiatric disorders, including Alzheimer's disease (AD). We have studied mechanisms implicated in vulnerability to stress and the relationship with changes in AD-related markers. EXPERIMENTAL APPROACH: Anhedonia induced by a chronic mild stress (CMS) procedure, applied for 6 weeks, was used to select rats vulnerable or resistant to stress. Sucrose intake, the Porsolt forced swimming test and cognitive deficits in the novel object recognition test (NORT) were used to characterize vulnerable and resilient rats. The antidepressant venlafaxine (20 mg·kg(-1) p.o.) or saline was administered daily during the last 2 weeks of CMS. Biochemical markers affected by stress, PKB, ERK and synaptophysin, and those associated with AD, amyloid ß-protein (Aß), ß-secretase (BACE1) and τ phosphorylation, were measured in the hippocampus. KEY RESULTS: After CMS, 40% of rats were resistant to the development of anhedonia (CMS-resistant to stress), whereas the remaining were responsive [CMS-anhedonic (CMSA)]. Only CMSA rats displayed significant increases in immobility time in the forced swimming test and cognitive deficits in the NORT, and significant decreases in synaptophysin, phosphorylated PKB and phosphorylated ERK1/2 expression in the hippocampus. Increased levels of Aß40, BACE1 and τ phosphorylation were also found only in CMSA rats. All these effects in CMSA rats were reverted by treatment with venlafaxine. CONCLUSIONS AND IMPLICATIONS: Vulnerability to stress might constitute a risk factor for the development of AD, and pharmacological treatment with venlafaxine may represent a therapeutic strategy for the treatment of stress-related disorders, including AD.

[Prediction of PaO2/FiO2 ratio from SpO2/FiO2 ratio adjusted by transcutaneous CO2 measurement in critically ill children]. / Predicción del índice PaO2/FiO2 a partir del índice SpO2/FiO2 ajustado por la medición transcutánea de CO2 en niños críticamente enfermos.

OBJECTIVE: To evaluate if the inclusion of the transcutaneous CO(2) tension measurement (PtcCO(2)) can improve partial pressure of oxygen/ fraction of inspired oxygen ratio [PaO(2)/FiO(2) (P/F)] prediction from pulse oximetry saturation/FiO(2) ratio [SpO(2)/FiO(2) (S/F)]. METHODS: Retrospective analysis of blood gas data from critically ill children. PaO(2), SpO(2), FiO(2) and PtcCO(2) from 40 samples in 8 patients were analysed. A multiple linear regression model was performed to predict P/F ratio from S/F ratio and PtcCO(2). Using the equation obtained, S/F ratio values were calculated for P/F ratios of 200 and 300 and different levels of PtcCO2. Receiver Operator Characteristic (ROC) curves were made to analyse the diagnostic values of P/F ratio (200 and 300). RESULTS: The linear regression model was: P/F=37.277+(1.072×S/F) - (1.567×PtcCO2); P<.0001; R(2)=0.469. Using the equation, for a PtcCO(2) value of 40 mmHg, P/F ratios of 200 and 300 corresponded to S/F ratios of 295.1 and 426.5, respectively. Computed P/F ratio less than 256.7 had 84.6% sensitivity and 85.2% specificity for the diagnosis of P/F ratio less than 200. Computed P/F ratio less than 297.6 had 89.7% sensitivity and 82% specificity for the diagnosis of P/F ratio less than 300. CONCLUSION: PtcCO(2) has a significant influence on the prediction of P/F ratio from S/F ratio. Prospective studies with more patients are needed to validate these results.

[Lung simulator]. / Simulador de pulmón.

INTRODUCTION: One of the main limitations to running mechanical ventilation courses is the lack of cheap, interactive, and easily reproducible lung simulators. OBJECTIVE: Presentation of a new lung simulator. MATERIAL: Lung simulator consisting of two different parts: A) Resistance system: simulates respiratory airway. It is made up of 3 or 5 ball valves that allow for the simulation of resistance increase and air leaks. B) Compliance system: it reproduces lungs and rib cage characteristics. It is made up of three parts: 1 or 2 expandable chambers (a commercial test lung), a connection system to the resistance mechanism, and a distensibility limiting clamp. The simulator allows for a single or double assembly depending on the inclusion of one or two lungs to the resistance system, allowing the tidal volume to be adjusted from 10 to 500 ml. CONCLUSIONS: We present an easily assembled lung simulator for teaching purposes that is cheap, reproducible and interactive, allowing for simulation of patterns of restriction, obstruction, and presence of air leaks.

Technological and sensory characteristics of reduced/low-fat, low-salt frankfurters as affected by the addition of konjac and seaweed.

This paper reports the effect of an edible seaweed, Sea Spaghetti (Himanthalia elongata), on the physicochemical (emulsion stability, cooking loss, colour, texture, residual nitrite and microstructure) and sensory characteristics of reduced- and low-fat, low-salt (NaCl) frankfurters prepared with konjac gel as a fat substitute. The effects on emulsion stability of substituting konjac gel for pork backfat were conditioned by the proportion of the substitution. Incorporation of a combination of Sea Spaghetti/konjac gel (accompanied by reduction in salt) increased (P<0.05) cooking loss and reduced (P<0.05) emulsion stability in the gel/emulsion systems. Incorporation of Sea Spaghetti/konjac gel produced a decrease (P<0.05) of lightness (L*) and redness (a*) values and an increase (P<0.05) of yellowness (b*) as compared to the other samples. The effect of adding seaweed on the texture parameters of low-salt frankfurters varied depending on the proportion of konjac gel used in the formulation. Morphological differences in frankfurter microstructure were observed as fat content was reduced and konjac gel increased. Incorporation of a combination of Sea Spaghetti/konjac gel caused the formation of a more heterogeneous structure, in which the seaweed was integrated in the meat protein matrix.

Massive lower gastrointestinal haemorrhage, successfully treated with corticosteroids, as main symptom of Schönlein-Henoch purpura.

Schönlein-Henoch purpura is a small vessel disease that affects mainly skin and kidney, although several gastrointestinal symptoms may occur including abdominal pain, intussusception, perforation or bleeding. Massive lower gastrointestinal haemorrhage is rare and even more as the main symptom of the disease. We present a case of a 2-year-old boy with Schönlein-Henoch purpura who developed a massive lower gastrointestinal bleeding requiring blood transfusion. In this patient both Schönlein-Henoch purpura and gastrointestinal haemorrhage were successfully treated with intravenous methylprednisolone, avoiding surgical intervention. Physicians need to have a high index of suspicion when evaluating these patients, even more when dermatologic signs are scarce. Glucocorticosteroid therapy may be effective when treating severe gastrointestinal symptoms.

Anisakis antigens detected in fish muscle infested with Anisakis simplex L3.

Anisakis simplex is a fish parasite that is a public health risk to those consuming raw or poorly cooked marine fish and cephalopods because of the possibility of becoming infested with live larvae. In humans, penetration of the larvae into the gastrointestinal track can cause acute and chronic symptoms and allergic anisakiasis. Excretion and secretion products released by the larvae are thought to play a role in migration through the tissues and induce an immunoglobulin E-mediated immune response. The aim of this preliminary study was to detect parasite antigens and allergens in fish tissues surrounding the migrating larvae. Hake and anchovy fillets were artificially parasitized with Anisakis larvae and stored in chilled conditions for 5 days. Larvae were evaluated for fluorescence, fish muscle tissue was examined with transmission electron microscopy, and immunohistochemical reactions of two rabbit polyclonal antisera against a parasite crude extract and the allergen Ani s 4 were recorded. Larvae immediately migrated into the fish muscle, and no emission of bluish fluorescence was observed. Fish muscle areas in contact with the parasite showed disruptions in the structure and inclusion of granules within sarcomeres. Both parasite antigens and the Ani s 4 allergen were located in areas close to the larvae and where sarcomere structure was preserved. These findings indicate that parasite antigens and allergens are dispersed into the muscle and might cause allergic symptoms such as dyspnea, vomiting, diarrhea, urticaria, angioedema, or anaphylaxis in some individuals sensitive to A. simplex.

Allergenic properties and cuticle microstructure of Anisakis simplex L3 after freezing and pepsin digestion.

This article examines the viability of and the alterations to the larval cuticle and the pattern of the antigens released when live or frozen Anisakis simplex larvae were treated with acid and pepsin. The results showed that freezing did not greatly alter the larva body. If ruptures were observed, the antigen release to the incubation media was not enhanced, and most of the antigenic content was retained inside the bodies of the larvae. The immunoblotting assay demonstrated that most of the antigens released, including the allergen Ani s 4, were resistant to pepsin. Freezing killed the larvae, but their survival was not compromised by acid treatment or pepsin digestion when kept chilled. All these findings support recommendations about freezing fish for consumption raw or undercooked to prevent human infection by A. simplex larvae. However, our data show that the antigenicity of the larvae is preserved after freezing and may explain why some sensitized patients develop symptoms after ingestion of infested frozen fish.

Influence of different types and proportions of added edible seaweeds on characteristics of low-salt gel/emulsion meat systems.

The effects of three different types of edible seaweeds, Sea Spaghetti (Himanthalia elongata), Wakame (Undaria pinnatifida), and Nori (Porphyra umbilicalis) added at two concentrations (2.5% and 5% dry matter) on the physicochemical and morphological characteristics of gel/emulsion systems were evaluated. The addition of seaweeds improved (P<0.05) water- and fat-binding properties except in the case of Nori added at 2.5%. Hardness and chewiness of the cooked products with added seaweed were higher (P<0.05), and springiness and cohesiveness were lower (P<0.05) than in control samples. Colour changes in meat systems were affected by the type of seaweed. The morphology of sample differed depending on the type of seaweed added, and this is the result of differences in physical and chemical characteristic of the seaweed powder used. In general, products formulated with the brown seaweeds (Sea Spaghetti and Wakame) exhibited similar behaviour, different from that of products made with the red seaweed Nori.

Physical study of minced fish muscle with a white-grape by-product added as an ingredient.

Functional properties of a white grape dietary fiber concentrate (WGDF) obtained from wine industry residues were determined with a view to their use as potential functional ingredient in seafood products. The main features of interest of WGDF are that it is a natural product containing high concentrations of dietary fiber (DF) with a high-soluble DF (sDF)/insoluble DF (iDF) ratio and associated bioactive compounds; as such it is considered potentially suitable for use as dietary fiber in the enrichment of foods. WGDF was therefore added to minced fish muscle (MFM) of horse mackerel (Trachurus trachurus) to take advantage of its technological properties, and also to enrich a food product that is a functional product in itself but does not contain dietary fiber. WGDF was added (2% and 4%) to MFM, which was stored for 6 mo at -20 degrees C, and a further lot was vacuum packed. Physical and mechanical properties, sensory and color analyses, microscopy, and electrophoretic profiles were all done in samples every month. The results indicate that WGDF had good functional properties, high water and oil retention capacity, and considerable swelling properties, which would make it useful as a natural ingredient in foods. The addition of WGDF to MFM augmented aggregation of myofibrillar proteins in the course of frozen storage, although electrophoretic profiles were very similar in samples with and without WGDF. The addition of WGDF to MFM made samples softer and less springy and cohesive. SEM showed good dispersion of WGDF in MFM but the matrix was more discontinuous than in the control. Water retention was significantly enhanced when WGDF was added, and the cooking yield improved. In sensory evaluation, samples containing 2% of WGDF scored highest in overall acceptance as compared with the control. Vacuum packing did not significantly affect the properties considered during frozen storage.

Ultrastructural changes and structure and mobility of myowater in frozen-stored hake (Merluccius merluccius L.) muscle: relationship with functionality and texture.

The ultrastructural changes and the main Raman spectral features of water (3100-3500 and 50-600 cm(-)(1) ranges) in frozen-stored hake were studied with the aim of connecting these changes with loss of some functional properties such as water holding capacity, and with modifications of muscle texture. The following results were obtained: (a) The changes in the spaces between myofibrils can be related to modifications of shear resistance. (b) The behavior of the strong 160 cm(-)(1) band can be related to conformational transitions of muscle proteins, to changes in the structure of muscle water, and/or to alterations in protein-water interactions. (c) There were intensity changes in the nu(s)(OH) band that may be attributable to transfer of water to larger spatial domains during frozen storage.