Taurine and the Brain.

This article briefly describes the trophic actions of taurine in the developing brain, contribution of taurine to the volume regulation of brain cells, and the interference of taurine with the synaptic amino acid receptors. Finally the possible use of taurine as a drug is discussed in various pathological states of the brain.When we searched material for this review, we got almost 4000 articles from the PubMed when using the terms "taurine and brain.

Clinical course and need for hospital admission after lithium discontinuation in patients with bipolar disorder type I or II: mirror-image study based on the LiSIE retrospective cohort.

Background: Currently, the evidence for lithium as a maintenance treatment for bipolar disorder type II (BD-II) remains limited. Guidelines commonly extrapolate recommendations for BD-II from available evidence for bipolar disorder type I (BD-I). Comparing the impact of lithium discontinuation is one way of assessing effectiveness in both groups.

Correction to: Reasons for lithium discontinuation in men and women with bipolar disorder: a retrospective cohort study.

Following publication of the original article [1], the authors reported an error in Fig. 1 and Table 1, concerning the number of female participants. The correct number is 283, instead of 238 that was originally published.

Automated image analysis detects aging in clinical-grade mesenchymal stromal cell cultures.

Background: Senescent cells are undesirable in cell therapy products due to reduced therapeutic activity and risk of aberrant cellular effects, and methods for assessing senescence are needed. Early-passage mesenchymal stromal cells (MSCs) are known to be small and spindle-shaped but become enlarged upon cell aging. Indeed, cell morphology is routinely evaluated during MSC production using subjective methods.

Method for Low Nanomolar Concentration Analyte Sensing Using Electrochemical Enzymatic Biosensors.

We introduce a new electrochemical measurement method compatible with an enzymatic biosensor that is capable of analyte sensing down to the low nanomolar concentration regime. This method is termed accumulation mode sensing and utilizes an immobilized redox polymer mediator wired to an oxidoreductase enzyme to store charge during a premeasurement charge concentration step, followed by a measurement step in which this accumulated charge is quantified. We demonstrate this new method using a model glucose sensor and show how the sensitivity of a sensor can be modified simply by adjusting the time duration of the charge concentration step.

Collision Dynamics during the Electrooxidation of Individual Silver Nanoparticles.

Recent high-bandwidth recordings of the oxidation and dissolution of 35 nm radius Ag nanoparticles at a Au microelectrode show that these nanoparticles undergo multiple collisions with the electrode, generating multiple electrochemical current peaks. In the time interval between observed current peaks, the nanoparticles diffuse in the solution near the electrolyte/electrode interface. Here, we demonstrate that simulations of random nanoparticle motion, coupled with electrochemical kinetic parameters, quantitatively reproduce the experimentally observed multicurrent peak behavior.

Comparison of Toxicity of Taurine and GABA in Combination with Alcohol in 7-Day-Old Mice.

Previously, we described the combined toxicity of taurine and alcohol, and assumed hypoglycemia to be one reason of this toxicity. To understand whether taurine-ethanol combined toxicity is exclusively connected to taurine or whether other inhibitory amino acids may have similar effects when combined with ethanol, we tested different doses of gamma-aminobutyric acid (GABA) in combination with ethanol in 7-day-old mice. The minimal dose of GABA in combination with 5 g/kg ethanol which could kill a mouse was 2 g/kg.

Significance of Taurine in the Brain.

Two main functions of taurine in the brain are here discussed: the role of taurine in cell volume regulation and the neuromodulatory actions of taurine liberated by depolarization. Taurine takes part in cell volume regulation with other small-molecular compounds. Extracellular taurine inhibits neuronal firing through GABA and glycine receptors.

Observation of Multipeak Collision Behavior during the Electro-Oxidation of Single Ag Nanoparticles.

The dynamic collision behavior of the electro-oxidation of single Ag nanoparticles is observed at Au microelectrodes using stochastic single-nanoparticle collision amperometry. Results show that an Ag nanoparticle collision/oxidation event typically consists of a series of 1 to ∼10 discrete "sub-events" over an ∼20 ms interval. Results also show that the Ag nanoparticles typically undergo only partial oxidation prior to diffusing away from the Au electrode into the bulk solution.

Electrogenerated Chemiluminescence Reporting on Closed Bipolar Microelectrodes and the Influence of Electrode Size.

We report a fundamental study of the use of Ru(bpy)-based electrogenerated chemiluminescence (ECL) as an optical reporting system for the detection of redox-active analyte on closed bipolar microelectrodes, focused on gaining an in-depth understanding of the correlation between ECL emission intensity and electrochemical current. We demonstrate the significant effect that the size of the anodic and cathodic poles has on the resulting ECL signal and show how this influences the quantitative detection of analyte on a closed bipolar electrode. By carefully designing the geometry of the bipolar electrode, the detection performance of the system can be tuned to different analyte concentration ranges.

Neurotoxicity of Ammonia.

Abnormal liver function has dramatic effects on brain functions. Hyperammonemia interferes profoundly with brain metabolism, astrocyte volume regulation, and in particular mitochondrial functions. Gene expression in the brain and excitatory and inhibitory neurotransmission circuits are also affected.

Electroretinography and Visual Evoked Potentials in Childhood Brain Tumor Survivors.

This population-based cross-sectional study evaluates the clinical value of electroretinography and visual evoked potentials in childhood brain tumor survivors. A flash electroretinography and a checkerboard reversal pattern visual evoked potential (or alternatively a flash visual evoked potential) were done for 51 survivors (age 3.8-28.

Properties of Taurine Release in Glucose-Free Media in Hippocampal Slices from Developing and Adult Mice.

The release of preloaded [(3)H]taurine from hippocampal slices from developing 7-day-old and young adult 3-month-old mice was studied in a superfusion system in the absence of glucose. These hypoglycemic conditions enhanced the release at both ages, the effect being markedly greater in developing mice. A depolarizing K(+) concentration accentuated the release, which indicates that it was partially mediated by exocytosis.

Osteogenic differentiation of mesenchymal stromal cells in two-dimensional and three-dimensional cultures without animal serum.

Introduction: Bone marrow-derived mesenchymal stromal cells (MSCs) have been intensely studied for the purpose of developing solutions for clinical tissue engineering. Autologous MSCs can potentially be used to replace tissue defects, but the procedure also carries risks such as immunization and xenogeneic infection. Replacement of the commonly used fetal calf serum (FCS) with human platelet lysate and plasma (PLP) to support cell growth may reduce some of these risks.

A robust and reproducible animal serum-free culture method for clinical-grade bone marrow-derived mesenchymal stromal cells.

Efficient xenofree expansion methods to replace fetal bovine serum (FBS)-based culture methods are strongly encouraged by the regulators and are needed to facilitate the adoption of mesenchymal stromal cell (MSC)-based therapies. In the current study we established a clinically-compliant and reproducible animal serum-free culture protocol for bone marrow-(BM-) MSCs based on an optimized platelet-derived supplement. Our study compared two different platelet-derived supplements, platelet lysate PL1 versus PL2, produced by two different methods and lysed with different amounts of freeze-thaw cycles.

Imaging transient formation of diffusion layers with fluorescence-enabled electrochemical microscopy.

Fluorescence-enabled electrochemical microscopy (FEEM) is demonstrated as a new technique to image transient concentration profiles of redox species generated on ultramicroelectrodes (UMEs). FEEM converts an electrical signal into an optical signal by electrically coupling a conventional redox reaction to a fluorogenic reporter reaction on a closed bipolar electrode. We describe the implementation of FEEM for diffusion layer imaging and use an array of thousands of parallel bipolar electrodes to image the diffusion layers of UMEs in two and three dimensions.

Modulation by kynurenine of extracellular kynurenate and glutamate in cerebral cortex of rats with acute liver failure.

Background: Kynurenic acid (KYNA) modulates the glutamatergic tone by controlling neuronal glutamate (GLU) release. The present study tested the potential of the KYNA precursor, kynurenine (KYN) to counter increased extracellular GLU associated with the pathogenesis of hepatic encephalopathy accompanying acute liver failure (ALF).

Methods: ALF was induced in adult rats by administration of a hepatotoxin, thioacetamide.

Fluorescence-enabled electrochemical microscopy with dihydroresorufin as a fluorogenic indicator.

Recently, we introduced a new electrochemical imaging technique called fluorescence-enabled electrochemical microscopy (FFEM). The central idea of FEEM is that a closed bipolar electrode is utilized to electrically couple a redox reaction of interest to a complementary fluorogenic reaction converting an electrochemical signal into a fluorescent signal. This simple strategy enables one to use fluorescence microscopy to observe conventional electrochemical processes on very large electrochemical arrays.

Taurine and epilepsy.

Dysfunction of excitatory and inhibitory neurotransmitters or neuromodulators is thought to underlie epileptic symptoms. Taurine, 2-aminoethanesulfonate, is a ubiquitous free amino acid abounding in the brain of humans and most animal species. It hyperpolarizes neurons and inhibits their firing.