Vitamin B12 Deficiency and the Nervous System: Beyond Metabolic Decompensation-Comparing Biological Models and Gaining New Insights into Molecular and Cellular Mechanisms.

Vitamin B12 (VitB12) is a micronutrient and acts as a cofactor for fundamental biochemical reactions: the synthesis of succinyl-CoA from methylmalonyl-CoA and biotin, and the synthesis of methionine from folic acid and homocysteine. VitB12 deficiency can determine a wide range of diseases, including nervous system impairments. Although clinical evidence shows a direct role of VitB12 in neuronal homeostasis, the molecular mechanisms are yet to be characterized in depth. Earlier investigations focused on exploring the biochemical shifts resulting from a deficiency in the function of VitB12 as a coenzyme, while more recent studies propose a broader mechanism, encompassing changes at the molecular/cellular levels. Here, we explore existing study models employed to investigate the role of VitB12 in the nervous system, including the challenges inherent in replicating deficiency/supplementation in experimental settings. Moreover, we discuss the potential biochemical alterations and ensuing mechanisms that might be modified at the molecular/cellular level (such as epigenetic modifications or changes in lysosomal activity). We also address the role of VitB12 deficiency in initiating processes that contribute to nervous system deterioration, including ROS accumulation, inflammation, and demyelination. Consequently, a complex biological landscape emerges, requiring further investigative efforts to grasp the intricacies involved and identify potential therapeutic targets.

New Insights into the Neurodegeneration Mechanisms Underlying Riboflavin Transporter Deficiency (RTD): Involvement of Energy Dysmetabolism and Cytoskeletal Derangement.

Riboflavin transporter deficiency (RTD) is a rare genetic disorder characterized by motor, sensory and cranial neuropathy. This childhood-onset neurodegenerative disease is caused by biallelic pathogenic variants in either SLC52A2 or SLC52A3 genes, resulting in insufficient supply of riboflavin (vitamin B2) and consequent impairment of flavoprotein-dependent metabolic pathways. Current therapy, empirically based high-dose riboflavin supplementation, ameliorates the progression of the disease, even though response to treatment is variable and partial. Recent studies have highlighted concurrent pathogenic contribution of cellular energy dysmetabolism and cytoskeletal derangement. In this context, patient specific RTD models, based on induced pluripotent stem cell (iPSC) technology, have provided evidence of redox imbalance, involving mitochondrial and peroxisomal dysfunction. Such oxidative stress condition likely causes cytoskeletal perturbation, associated with impaired differentiation of RTD motor neurons. In this review, we discuss the most recent findings obtained using different RTD models. Relevantly, the integration of data from innovative iPSC-derived in vitro models and invertebrate in vivo models may provide essential information on RTD pathophysiology. Such novel insights are expected to suggest custom therapeutic strategies, especially for those patients unresponsive to high-dose riboflavin treatments.

Altered cytoskeletal arrangement in induced pluripotent stem cells (iPSCs) and motor neurons from patients with riboflavin transporter deficiency.

The cytoskeletal network plays a crucial role in differentiation, morphogenesis, function and homeostasis of the nervous tissue, so that alterations in any of its components may lead to neurodegenerative diseases. Riboflavin transporter deficiency (RTD), a childhood-onset disorder characterized by degeneration of motor neurons (MNs), is caused by biallelic mutations in genes encoding the human riboflavin (RF) transporters. In a patient- specific induced Pluripotent Stem Cells (iPSCs) model of RTD, we recently demonstrated altered cell-cell contacts, energy dysmetabolism and redox imbalance.The present study focusses on cytoskeletal composition and dynamics associated to RTD, utilizing patients' iPSCs and derived MNs. Abnormal expression and distribution of α- and ß-tubulin (α- and ß-TUB), as well as imbalanced tyrosination of α-TUB, accompanied by impaired ability to repolymerize after nocodazole treatment, were found in RTD patient-derived iPSCs. Following differentiation, MNs showed consistent changes in TUB content, which was associated with abnormal morphofunctional features, such as neurite length and Ca++ homeostasis, suggesting impaired differentiation.Beneficial effects of RF supplementation, alone or in combination with the antioxidant molecule N-acetyl-cystine (NAC), were assessed. RF administration resulted in partially improved cytoskeletal features in patients' iPSCs and MNs, suggesting that redundancy of transporters may rescue cell functionality in the presence of adequate concentrations of the vitamin. Moreover, supplementation with NAC was demonstrated to be effective in restoring all the considered parameters, when used in combination with RF, thus supporting the therapeutic use of both compounds.

Antioxidant Amelioration of Riboflavin Transporter Deficiency in Motoneurons Derived from Patient-Specific Induced Pluripotent Stem Cells.

Mitochondrial dysfunction is a key element in the pathogenesis of neurodegenerative disorders, such as riboflavin transporter deficiency (RTD). This is a rare, childhood-onset disease characterized by motoneuron degeneration and caused by mutations in SLC52A2 and SLC52A3, encoding riboflavin (RF) transporters (RFVT2 and RFVT3, respectively), resulting in muscle weakness, ponto-bulbar paralysis and sensorineural deafness. Based on previous findings, which document the contribution of oxidative stress in RTD pathogenesis, we tested possible beneficial effects of several antioxidants (Vitamin C, Idebenone, Coenzyme Q10 and EPI-743, either alone or in combination with RF) on the morphology and function of neurons derived from induced pluripotent stem cells (iPSCs) from two RTD patients. To identify possible improvement of the neuronal morphotype, neurite length was measured by confocal microscopy after ß-III tubulin immunofluorescent staining. Neuronal function was evaluated by determining superoxide anion generation by MitoSOX assay and intracellular calcium (Ca2+) levels, using the Fluo-4 probe. Among the antioxidants tested, EPI-743 restored the redox status, improved neurite length and ameliorated intracellular calcium influx into RTD motoneurons. In conclusion, we suggest that antioxidant supplementation may have a role in RTD treatment.

Mitochondrial and Peroxisomal Alterations Contribute to Energy Dysmetabolism in Riboflavin Transporter Deficiency.

Riboflavin transporter deficiency (RTD) is a childhood-onset neurodegenerative disorder characterized by progressive pontobulbar palsy, sensory and motor neuron degeneration, sensorineural hearing loss, and optic atrophy. As riboflavin (RF) is the precursor of FAD and FMN, we hypothesize that both mitochondrial and peroxisomal energy metabolism pathways involving flavoproteins could be directly affected in RTD, thus impacting cellular redox status. In the present work, we used induced pluripotent stem cells (iPSCs) from RTD patients to investigate morphofunctional features, focusing on mitochondrial and peroxisomal compartments. Using this model, we document the following RTD-associated alterations: (i) abnormal colony-forming ability and loss of cell-cell contacts, revealed by light, electron, and confocal microscopy, using tight junction marker ZO-1; (ii) mitochondrial ultrastructural abnormalities, involving shape, number, and intracellular distribution of the organelles, as assessed by focused ion beam/scanning electron microscopy (FIB/SEM); (iii) redox imbalance, with high levels of superoxide anion, as assessed by MitoSOX assay accompanied by abnormal mitochondrial polarization state, evaluated by JC-1 staining; (iv) altered immunofluorescence expression of antioxidant systems, namely, glutathione, superoxide dismutase 1 and 2, and catalase, as assessed by quantitatively evaluated confocal microscopy; and (v) peroxisomal downregulation, as demonstrated by levels and distribution of fatty acyl ß-oxidation enzymes. RF supplementation results in amelioration of cell phenotype and rescue of redox status, which was associated to improved ultrastructural features of mitochondria, thus strongly supporting patient treatment with RF, to restore mitochondrial- and peroxisomal-related aspects of energy dysmetabolism and oxidative stress in RTD syndrome.

Caracterización bibliométrica de las revistas odontológicas colombianas indexadas en la segunda actualización del Publindex 2014 / Bibliometric characterization of colombian dental journals indexed in the second update of 2014 Publindex

Aim: To characterize the Colombian jo- urnals of dentistry indexed in the second update of Publindex 2014 from the biblio- metric point of view, to describe the ten- dencies of the publications in the thematic areas of dentistry. Materials and methods: A descriptive cross-sectional documentary study that carried out a bibliometric analysis of the scientific articles published in seven dental journals (Revista de la Facultad de Odon- tología de la Universidad de Antioquia, CES Odontología, Universitas Odonto- logica, Revista Nacional de Odontología, Acta Odontológica Colombiana, Revista Odontos Odontologia Integral y Revista Colombiana de Investigación en Odonto- logía) recognized and categorized in the second update of Publindex 2014. Results: A total of 1587 publications (of which 62% were original articles derived from research) were identified in a A2 category (360), two in B category (636) and four in C category (332). Conclusions: The bibliometric analysis of the eight journals evidences that the Revista de la Facultad de Odontología de la Universidad de Antioquia and the Re- vista CES Odontología, being the oldest, are the journals that have best adapted to Publindex guidelines, the only journals included in SciELO and the two journals with the highest index h5 ­five and seven respectively­ of Google Scholar

Objetivo: Caracterizar las revistas odonto- lógicas colombianas indexadas en la segun- da actualización del Publindex 2014 desde el punto de vista bibliométrico para descri- bir las tendencias de las publicaciones en cuanto a las áreas temáticas odontológicas. Materiales y Métodos: Estudio descriptivo documental de corte transversal que realizó un análisis bibliométrico de los artículos científicos publicados en siete revistas odontológicas (Revista de la Facultad de Odontología de la Universidad de Antio- quia, CES Odontología, Universitas Odon- tologica, Revista Nacional de Odontología, Acta Odontológica Colombiana, Revista Odontos Odontología Integral y Revista Colombiana de Investigación en Odonto- logía) reconocidas y categorizadas en la segunda actualización del Publindex 2014. Resultados: Se identificaron un total de 1587 publicaciones (de los cuales el 62% fueron artículos originales derivados de investigación) distribuidos en una revista categoría A2 (360), en dos revistas catego- ría B (636) y en cuatro revistas categoría C (332). Conclusiones: El análisis bibliométrico de las ocho revistas evidencia que la Revista de la Facultad de Odontología de la Uni- versidad de Antioquia y la Revista CES Odontología, siendo las más antiguas, son las revistas que mejor se han adaptado a los lineamientos del Publindex, las únicas revistas incluidas en SciELO y las dos revistas con el índice h5 mas alto ­cinco y siete respectivamente­de Google Scholar.

Effect of the cross-linking agent and drying method on encapsulation efficiency of orange essential oil by complex coacervation using whey protein isolate with different polysaccharides.

Orange essential oil was microencapsulated by complex coacervation with whey protein isolate (WPI): carboxymethylcellulose (CMC), WPI:sodium alginate (SA) and WPI:chitosan (CH). Effect of pH, protein:polysaccharide ratio and solid concentration on coacervation efficiency were selected for the best coacervation conditions. Tannic acid (TA), sodium tripolyphosphate, oxidised tannic acid and transglutaminase enzyme (TG) were used as cross-linking agents. Highest encapsulation efficiency (EE) for wet coacervated microcapsules ranged from 88% to 94%. Microcapsules were freeze and spray dried to evaluate their effect on its integrity. EE was higher than 80% in freeze dried coacervated microcapsules with and without cross-linking agent, but they formed a solid cake. Spray-dried samples formed a free fluid solid (10-20 µm), where the systems WPI:CMC and WPI:CH cross-linked with TA and TG, respectively showed the highest EE (47% and 50% respectively), representing 400% improvement compared to the samples without cross-linking.

Cocoa protective effects against abnormal fat storage and oxidative stress induced by a high-fat diet involve PPARα signalling activation.

A high-fat (HF) diet increases lipid storage and oxidative stress in mouse liver and this process seems to be mediated by Peroxisome Proliferator-Activated Receptor α (PPARα). In this study we evaluated the protective effect of cocoa against hepatic steatosis induced by a HF diet. The HF diet down-regulated PPARα expression and turned off PPARα-signalling, deregulated the ß-oxidation (ß-Ox) system and catalase (CAT) activity, increased fat storage, reduced expression of enzymatic activity involved in oxidative defence in the liver and doubled the weight gain per calorie consumed compared to animals under the normal diet. In contrast, cocoa improved hepatic ß-Ox, activated PPARα-signalling and up-regulated both gene and protein expression of SOD1. Moreover, when co-administered with the HF diet, cocoa treatment counteracted lipid storage in the liver, improved the lipid-metabolizing activity and oxidative stress defences and normalized the weight gain per calorie consumed.

Systematic review of efficacy and safety of pemetrexed in non-small-cell-lung cancer.

INTRODUCTION: Lung cancer accounts for 20 % of cancer deaths in Spain. The most frequent subtype (87 %) is non-small cell lung cancer (NSCLC). Pemetrexed is a recently marketed drug added to NSCLC therapeutic arsenal. It seems to have become one of the most used options for the treatment of this condition over the last 3 years. AIM OF THE REVIEW: To evaluate the efficacy and safety of pemetrexed in NSCLC, in the different therapy lines. Method A systematic search of published literature was conducted using the main databases (MEDLINE, EMBASE, the Cochrane Library and the Center for Reviews and Dissemination) and subsequently a search of referenced literature was performed. We included clinical trials, meta-analyses and systematic reviews. The evaluation of the quality of the articles was performed by pairs using specific assessment scales, Critical Appraisal Skills Program (CASP) adapted for CASP Spain. Then we extracted data on efficacy and safety according to the treatment line assessed. RESULTS: We identified 277 references. Finally, nine clinical trials and a meta-analysis complied with inclusion criteria. In first-line induction, treatment with pemetrexed associated with a platinum was similar in terms of efficacy to other alternative chemotherapy regimens, except in patients with non-squamous histology, in whom survival was higher in the experimental group. In maintenance treatment, greater efficacy was seen with pemetrexed in patients with non-squamous histology. In second-line treatment, there were no significant differences in terms of efficacy and safety for pemetrexed treatment versus other chemotherapy options. The most frequent adverse reactions were: hematological, gastrointestinal and neurological. All were significantly less frequent with pemetrexed versus other alternative therapies, except for liver toxicity. CONCLUSIONS: Due to the high degree of uncertainty as to its efficacy in certain subgroups of patients, including conflicting data; to its recent incorporation, and therefore lack of safety data in the medium and long term, and the high budgetary impact of its incorporation into health systems, it seems reasonable to optimize its use, identifying those patients who may benefit most.

Simvastatin treatment highlights a new role for the isoprenoid/cholesterol biosynthetic pathway in the modulation of emotional reactivity and cognitive performance in rats.

The aim of the present work was to shed light on the role played by the isoprenoid/cholesterol biosynthetic pathway in the modulation of emotional reactivity and memory consolidation in rodents through the inhibition of the key and rate-limiting enzyme 3-hydroxy 3-methylglutaryl Coenzyme A reductase (HMGR) both in vivo and in vitro with simvastatin. Three-month-old male Wistar rats treated for 21 days with simvastatin or vehicle were tested in the social interaction, elevated plus-maze, and inhibitory avoidance tasks; after behavioral testing, the amygdala, hippocampus, prefrontal cortex, dorsal, and ventral striatum were dissected out for biochemical assays. In order to delve deeper into the molecular mechanisms underlying the observed effects, primary rat hippocampal neurons were used. Our results show that HMGR inhibition by simvastatin induces anxiogenic-like effects in the social interaction but not in the elevated plus-maze test, and improves memory consolidation in the inhibitory avoidance task. These effects are accompanied by imbalances in the activity of specific prenylated proteins, Rab3 and RhoA, involved in neurotransmitter release, and synaptic plasticity, respectively. Taken together, the present findings indicate that the isoprenoid/cholesterol biosynthetic pathway is critically involved in the physiological modulation of both emotional and cognitive processes in rodents.

Estudio comparativo entre la técnica anestésica alveolar superior medio anterior y la técnica infiltrativa / A comparative study between the anterior middle superior alveolar and the infiltrative block techniques

Antecedentes: la técnica anestésica más usada en odontología para el bloqueo del nervio alveolar superior anterior y medio es la infiltrativa; sin embargo, produce el bloqueo nervioso de los músculos de la expresión, lo cual es negativo para algunos procedimientos de odontología restauradora. Existe una nueva técnica de inyección para la arcada superior, el bloqueo alveolar superior medio anterior (ASMA), que consigue anestesia pulpar del incisivo central hasta el segundo premolar, con la gran ventaja de que no produce anestesia colateral de la cara y músculos de la expresión; además, quedan anestesiados los tejidos blandos palatinos de la región. Objetivo: comparar la efectividad de las técnicas anestésicas infiltrativa y ASMA para el nervio alveolar superior anterior y medio, con el fin de proponer su uso en la práctica diaria odontológica. Método: se realizó un estudio descriptivo y analítico. La muetra fue 10 estudiantes de la Facultad de Odontología de la Pontificia Universidad Javeriana con dientes anteriores, caninos y premolares superiores vitales y que no fueran alérgicos al anestésico local, a quienes se les aplicaron las dos técnicas en dos citas diferentes y se realizaron pruebas de vitalidad inicial y postanestesia, con el vitalómetro, para determinar el grado de respuesta pulpar. Se analizaron los resultados por medio de las pruebas de U de Mann Whitney y Chi2. Resultados: al comparar la respuesta pulpar de cada diente, se determinó que la técnica infiltrativa fue superior a la técnica ASMA en lo que se refiere a la profundidad anestésica. Al comparar la anestesia colateral de los músculos de la expresión, ala de la nariz y mucosa vestibular, se encontró una diferencia significativa entre estas dos técnicas, ya que con la técnica ASMA no se presentó en ningún caso este tipo de anestesia muscular, mientras que con la infiltrativa los 10 pacientes presentaron anestesia de estas estructuras. Conclusiones: con la técnica ASMA se logró menor profundidad anestésica para el bloqueo del impulso nervioso en la región anterior superior, especialmente en el incisivo central. No se presentó anestesia colateral de cara y músculos de la expresión al utilizar la técnica ASMA. Como efecto adverso, con la técnica ASMA se presentó dolor durante la aplicación; sin embargo, esta técnica fue menos dolorosa que la técnica infiltrativa