Search

Thrombin effect increasing swelling-induced glutamate efflux was examined in cultured cortical astrocytes, cerebellar granule neurons (CGN), hippocampal and cortical neurons. Hypotonic glutamate efflux (monitored by d-[H]aspartate) from cortical astrocytes was increased by thrombin (5 U/mL) to reach 16 % of the cell pool in 5 min. Thrombin had lower effects in CGN, and marginal effects in hippocampal and cortical neurons. These differences were related to the magnitude of thrombin-evoked cytosolic calcium rise. The protease-activated receptor 1 is expressed in astrocytes and neurons. In astrocytes exposed to chemical ischemia (sodium iodoacetate plus sodium azide) d-[H]aspartate release showed a first phase (20-40 min) of initial low efflux which progressively increases; and a second phase (40-60 min) of larger efflux coincident with cell swelling. Efflux at the first phase was 52 % inhibited by the glutamate transporter blocker DL- threo-β-benzyloxyaspartic-acid (TBOA) and 11 % by the volume-sensitive pathway blocker phloretin. At the second phase, efflux was reduced 52 and 38 % respectively, by these blockers. In CGN d-[H]aspartate efflux increased sharply and then decreased. This efflux was 32 % reduced by calcium omission, 46 % by TBOA and 32 % by 4-[(2-butyl-6,7dichloro-2-cyclopentyl-2,3-dihydro-1oxo-1 H-inden-5-yl)oxy] butanoic-acid. Thrombin enhanced this release by 32 %. Ischemic treatment increased astrocyte mortality from 4 % in controls to 39 and 61 % in ischemia and ischemia plus thrombin, respectively. Cell death was prevented by phloretin. CGN viability was unaffected by the treatment. These results suggest that coincidence of swelling and thrombin during ischemia elevates extracellular glutamate prominently from astrocyte efflux, which may endanger neurons in vivo. [ABSTRACT FROM AUTHOR]

The objective of this prospective cohort study was to compare fructose malabsorption in patients with functional chronic abdominal pain and in healthy children. The sample was divided into two groups: asymptomatic children and pain-predominant functional gastrointestinal disorders according to the Rome IV criteria. All children were tested for fructose malabsorption by a standardized breath hydrogen test. Hydrogen and methane were measured and the test was presumed positive when it exceeded 20 ppm above baseline. If positive, patients were given a low-fructose diet and the response was evaluated. One hundred five children were included (34 healthy children, 71 with functional chronic abdominal pain), with similar demographic characteristics in both groups (35.2% male, age 9.5 ± 2.8 years). Hydrogen levels in breath were tested through a hydrogen test for fructose demonstrating malabsorption in 58.8% of healthy children (95%CI 40.8%-76.8%) and in 40.8% of children with chronic abdominal pain (95%CI 28.7%-53.0%), removing those who had bacterial overgrowth. Twenty-one of 31 patients with symptoms and a positive test (72.4%) reported an improvement on a low-fructose diet.Conclusion: Fructose malabsorption is more common in asymptomatic children than in patients with chronic abdominal pain. Better standardized test conditions are necessary to improve accuracy of diagnosis before using this test in clinical practice. What is Known: • Although fructose malabsorption is believed to be related with chronic abdominal pain, high-quality evidence is lacking. • Concerns have raised regarding the use of breath hydrogen test for fructose malabsorption in children with chronic abdominal pain. What is New: • Fructose malabsorption is not more common in children with pain-predominant functional gastrointestinal disorders than in asymptomatic children. • Improvement in symptoms with low-fructose diet may indicate that, although patients with pain-predominant functional gastrointestinal disorders did not have a higher percentage of malabsorption, they had greater fructose intolerance.

Increased levels of circulating fatty acids, such as palmitic acid (PA), are associated with the development of obesity, insulin resistance, type-2 diabetes and metabolic syndrome. Furthermore, these diseases are linked to an increased risk of cancer, cardiovascular diseases, mild cognitive impairment and even Alzheimer's disease (AD). However, the precise actions of elevated PA levels on neurons and their association with neuronal metabolic disruption that leads to the expression of pathological markers of AD, such as the overproduction and accumulation of the amyloid-β peptide, represent an area of intense investigation. A possible molecular mechanism involved in the effects of PA may be through dysfunction of the NAD + sensor enzyme, SIRT1. Therefore, the aim of the present study was to analyze the relationship between the effects of PA metabolism on the function of SIRT1 and the upregulation of BACE1 in cultured hippocampal neurons. PA reduced the total amount of NAD + in neurons that caused an increase in p65 K310 acetylation due to inhibition of SIRT1 activity and low protein content. Furthermore, BACE1 protein and its activity were increased, and BACE1 was relocated in neurites after PA exposure.

Introduction: The remineralizing properties of saliva contribute to maintain the physical and chemical integrity of the mineral structure of teeth, which protects it from the installation and evolution of dental caries. Objective: To relate sialometry, buffering capacity, calcium and phosphate concentration in whole stimulated saliva, and in gingival crevicular fluid with school children caries severity and activity. Materials and methods: We selected 36 schoolchildren aged 6 years: 18 with caries (International Caries Detection and Assessment System, ICDAS>1 group) and 18 without caries (ICDAS=0 group). The severity and activity of dental caries were diagnosed in the primary dentition: in the occlusal surface of molars and in the vestibular of the anterior teeth by ICDAS-II. Results: Caries in occlusal surface were more severe than in vestibular surface. The concentration of calcium in saliva and phosphate in healthy teeth gingival crevicular fluid were higher in the ICDAS>1 group. The concentration of calcium in gingival crevicular fluid was higher in the ICDAS=0 group than in the decayed teeth of the ICDAS>1 group. We found a statistically significant association between the frequency of active caries andthe concentration of phosphate in gingival crevicular fluid of teeth with caries, as well as between the severity of caries with buffering capacity and the concentration of phosphate in the gingival crevicular fluid of teeth with caries. Conclusion: We found an association between dental caries with buffering capacity and buccal calcium and phosphate.

Neurogenesis is a plastic event modulated by external cues. Systemic inflammation decreases neurogenesis in the dentate gyrus (DG) in part through the proliferative restrain of neural precursor cells (NPCs). To evaluate if inflammation affects the cell cycle progression of particular populations of NPCs, we treated young-adult mice with a single i.p. injection of saline or 1 mg/kg LPS. After 7 days, we analysed proliferation of new BrdU+/DCX+ cells through immunohistochemistry. We extracted the hippocampus and performed a neurosphere assay and a flow cytometric analysis to evaluate proliferation and to identify the phase of the cell cycle in specific populations of DG-derived NPCs. We show that the number of BrdU+/DCX+ cells diminishes in the LPS-treated group and that the number of primary neurospheres derived from LPS-injected animals is significantly reduced compared to the saline-injected group. Flow cytometry revealed that inflammation does not affect the total number of Type 1 BLBP+/TBR2- cells, while the total number of Type 2 intermediate precursor cells (IPCs) (TBR2+) from the LPS-treated group was increased. Cell cycle analysis shows a decrease in the total rate of NPCs in phases S, G2 and M in the LPS-treated group. The percentage of Type 1 BLBP+/TBR2- cells in each cell cycle phase was not different between groups, while there was a fewer number of Type 2 TBR2+ cells in S/G2/M phase. These results show that inflammation alters the appropriate cell cycle progression of Type 2 IPCs, which may contribute to the decrease in the birth rate of DG neurons.

Neuronal activity in the retina generates osmotic gradients that lead to Müller cell swelling, followed by a regulatory volume decrease (RVD) response, partially due to the isoosmotic efflux of KCl and water. However, our previous studies in a human Müller cell line (MIO-M1) demonstrated that an important fraction of RVD may also involve the efflux of organic solutes. We also showed that RVD depends on the swelling-induced Ca 2+ release from intracellular stores. Here we investigate the contribution of taurine (Tau) and glutamate (Glu), the most relevant amino acids in Müller cells, to RVD through the volume-regulated anion channel (VRAC), as well as their Ca 2+ dependency in MIO-M1 cells. Swelling-induced [ 3 H]Tau/[ 3 H]Glu release was assessed by radiotracer assays and cell volume by fluorescence videomicroscopy. Results showed that cells exhibited an osmosensitive efflux of [ 3 H]Tau and [ 3 H]Glu (Tau > Glu) blunted by VRAC inhibitors 4-(2-butyl-6,7-dichloro-2-cyclopentylindan-1-on-5-yl)-oxybutyric acid and carbenoxolone reducing RVD. Only [ 3 H]Tau efflux was mainly dependent on Ca 2+ release from intracellular stores. RVD was unaffected in a Ca 2+ -free medium, probably due to Ca 2+ -independent Tau and Glu release, but was reduced by chelating intracellular Ca 2+ . The inhibition of phosphatidylinositol-3-kinase reduced [ 3 H]Glu efflux but also the Ca 2+ -insensitive [ 3 H]Tau fraction and decreased RVD, providing evidence of the relevance of this Ca 2+ -independent pathway. We propose that VRAC-mediated Tau and Glu release has a relevant role in RVD in Müller cells. The observed disparities in Ca 2+ influence on amino acid release suggest the presence of VRAC isoforms that may differ in substrate selectivity and regulatory mechanisms, with important implications for retinal physiology. NEW & NOTEWORTHY The mechanisms for cell volume regulation in retinal Müller cells are still unknown. We show that swelling-induced taurine and glutamate release mediated by the volume-regulated anion channel (VRAC) largely contributes the to the regulatory volume decrease response in a human Müller cell line. Interestingly, the hypotonic-induced efflux of these amino acids exhibits disparities in Ca 2+ -dependent and -independent regulatory mechanisms, which strongly suggests that Müller cells may express different VRAC heteromers formed by the recently discovered leucine-rich repeat containing 8 (LRRC8) proteins.

The dentate gyrus of the hippocampus is a plastic structure where adult neurogenesis constitutively occurs. Cell components of the neurogenic niche are source of paracrine as well as membrane-bound factors such as Notch, Bone Morphogenetic Proteins, Wnts, Sonic Hedgehog, cytokines, and growth factors that regulate adult hippocampal neurogenesis and cell fate decision. The integration and coordinated action of multiple extrinsic and intrinsic cues drive a continuous decision process: if adult neural stem cells remain quiescent or proliferate, if they take a neuronal or a glial lineage, and if new cells proliferate, undergo apoptotic death, or survive. The proper balance in the molecular milieu of this neurogenic niche leads to the production of neurons in a higher rate as that of astrocytes. But this rate changes in face of microenvironment modifications as those driven by physical exercise or with neuroinflammation. In this work, we first review the cellular and molecular components of the subgranular zone, focusing on the molecules, active signaling pathways and genetic programs that maintain quiescence, induce proliferation, or promote differentiation. We then summarize the evidence regarding the role of neuroinflammation and physical exercise in the modulation of adult hippocampal neurogenesis with emphasis on the activation of progression from adult neural stem cells to lineage-committed progenitors to their progeny mainly in murine models.

Nodular fasciitis is a benign fibroblastic tumour that does not commonly occur in the hand and generally does not exceed 5 cm in size. Given the characteristics of this entity, it demands a differential diagnosis with malignant tumours and infectious processes. We present an unusual case of nodular fasciitis in the palm of the hand, producing a lesion larger than any similar lesion reported previously in this location.

Hydatid disease is a parasitic infection generally occurring in specific geographical areas. Exclusive involvement of the muscles is extremely uncommon, because implantation at this site would require passage through the filters of the liver and lung. We describe a patient with a mass in the popliteal fossa of the knee for 7 years who was seen for pain and was found to have hydatid disease.