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The possibility that thiamine (vitamin B1) has a role in nervous tissue that is independent of its well-documented coenzyme function is discussed. After reviewing the localization and metabolism of the vitamin and its phosphate esters, the effects of either thiamine deprivation or antimetabolites of thiamine on conduction and transmission, and the relationship between thiamine triphosphate and the genetic, neurological disease, subacute necrotizing encephalomyelopathy (Leigh's disease), it is suggested that despite the lack of hard evidence, it is likely that the vitamin possesses this alternate function.
Mesh-terms: Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Problem-Based Learning :: standards; Keywords: thiamine; vitamin; nervou tissue; nervou; thiamine triphosphate; leigh disease; leigh; tissue; necrotize encephalomyelopathy; subacute necrotize; encephalomyelopathy; disease subacute; phosphate ester; thiamine vitamin; hard evidence;
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Department of Psychiatry, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA. ddwyer@lsuhsc.edu
This review will focus on the treatment and prevention of schizophrenia in children and adolescents. Neurodevelopmental theories suggest that loss of gray matter and defective synaptic function are major etiological factors in this disease. The efficacy of current antipsychotic medications has been discussed, however, these drugs produce serious side effects and may adversely affect the developing brain. We propose a novel therapeutic approach, termed neuroenhancement, that aims to promote neuronal survival and optimize neuronal function through the use of drugs. The goal is to enhance glucose metabolism in the brain, which would support higher functional activity in neurons and provide neuroprotection. Future drug development for the treatment of childhood schizophrenia should focus more on optimization of neuronal function rather than tranquilization and symptomatic relief.
Lennart Balk,
Per-Åke Hägerroth,
Gun Akerman,
Marsha Hanson,
Ulla Tjärnlund,
Tomas Hansson,
Gunnar Thor Hallgrimsson,
Yngve Zebühr,
Dag Broman,
Torsten Mörner,
Henrik Sundberg
Department of Applied Environmental Science, Stockholm University, SE-106 91 Stockholm, Sweden;
Wild birds of several species are dying in large numbers from an idiopathic paralytic disease in the Baltic Sea area. Here, we demonstrate strong relationships between this disease, breeding failure, and thiamine (vitamin B(1)) deficiency in eggs, pulli, and full-grown individuals. Thiamine is essential for vertebrates, and its diphosphorylated form functions as a cofactor for several life sustaining enzymes, whereas the triphosphorylated form is necessary for the functioning of neuronal membranes. Paralyzed individuals were remedied by thiamine treatment. Moreover, thiamine deficiency and detrimental effects on thiamine-dependent enzymes were demonstrated in the yolk, liver, and brain. We propose that the mortality and breeding failure are part of a thiamine deficiency syndrome, which may have contributed significantly to declines in many bird populations during the last decades.
Department of Therapeutic Drug Monitoring, Institute of Pharmacology, University of Cologne, Gleuelerstrasse 24, D-50931 Cologne, Germany.
An improved and easy to use method for the determination of thiamin diphosphate (TDP) in 100mul of whole blood was developed. The small sample volume makes it possible to assess the nutritional status of vitamin B(1) in infants and even in preterm infants. Sample preparation comprises the extraction of TDP from whole blood by hemolysis, protein precipitation with trichloroacetic acid, and subsequent centrifugation. Potassium ferricyanide is used for pre-column derivatization of TDP to its fluorescent thiochrome derivative. Chromatographic separation was carried out using a reversed-phase column and an isocratic elution which consisted of a phosphate buffer and acetonitrile. TDP was detected fluorimetrically and quantified by external standardization. Method validation showed a high precision, almost complete recovery, and a high sensitivity. The lower limit of detection and the lower limit of quantification were 0.2ng/ml and 4ng/ml, respectively. Linearity was demonstrated over the expected concentration range of 4-400ng/ml. In conclusion, we present a convenient HPLC method for the determination of TDP which is precise, sensitive and suitable for pediatric diagnostics.
Neuroscience Research Unit, Hôpital Saint-Luc (CHUM), 1058 St-Denis Street, Montreal, Quebec, Canada, H2X 3J4.
Thiamin plays a key role in the maintenance of brain function. Thiamin diphosphate is cofactor for several enzymes involved in glucose metabolism whereas thiamin triphosphate has distinct properties at the neuronal membrane. Thiamin metabolism in the brain is compartmented between neurons and neighbouring glial cells. Thiamin deficiency is commonly encountered in severe malnutrition associated with chronic alcoholism, HIV-AIDS and gastrointestinal disease where it frequently results in Wernicke's encephalopathy (the Wernicke-Korsakoff syndrome). Wernicke's encephalopathy is severely underdiagnosed according to clinical criteria in both alcoholic and HIV-AIDS patients. Magnetic resonance imaging reveals bilateral ventricular enlargement, mammillary body atrophy and cerebellar degeneration indicative of selective neuronal loss that is characteristic of Wernicke's encephalopathy. Several mechanisms have been proposed to explain this selective loss of neurons including a cerebral energy deficit resulting from reductions in activity of thiamin diphosphate-dependent enzymes, oxidative stress and N-methyl-D-aspartate receptor-mediated excitotoxicity. Both microglia and perivascular endothelial cells are sources of NO and oxidative stress in thiamin deficiency. Decreased activities of thiamin diphosphate-dependent enzymes (in particular alpha-ketoglutarate dehydrogenase) have also been reported in neurodegenerative diseases such as Alzheimer's and Parkinson's diseases independent of patient malnutrition. In these cases, decreased activities result from direct toxic actions of oxidative stress and beta-amyloid produced as part of the neuronal cell death cascade in these disorders.
24700 Center Ridge Road, Westlake Ohio 44145, USA. dlonsdale@pol.net.
Dysautonomia refers to a disease where the autonomic nervous system is dysfunctional. This may be a central control mechanism, as in genetically determined familial dysautonomia (Riley-Day Syndrome), or peripherally in the distribution of the sympathetic and parasympathetic systems. There are multiple reports of a number of different diseases associated with dysautonomia. The etiology of this association has never been explained. There are also multiple publications on dysautonomia associated with specific non-caloric nutritional deficiencies. Beriberi is the prototype of autonomic dysfunction. It is the best known nutritional deficiency disease caused by an imbalance between ingested calories and the vitamins required for their oxidation, particularly thiamin. Long thought to be abolished in modern medical thinking, there are occasional isolated reports of the full-blown disease in developed Western cultures. Apart from genetically and epigenetically determined disease, evidence is presented that marginal high calorie malnutrition, particularly with reference to simple carbohydrates, is responsible for widespread dysautonomia. The brain and heart are the organs that have a fast rate of oxidative metabolism and are affected early by any mechanism that reduces oxidative efficiency. It is hypothesized that this results in a chaotic state of the hypothalamic/autonomic/endocrine axis. Due to the lack of adequate automatic controls, this may be responsible in some cases for breakdown of organ systems through long-standing energy deficiency, thus leading eventually to organic disease.
Department of Human Life Science, Osaka Kun-Ei Women’s College, Sets city, Osaka 566-8501, Japan.
Various radical-scavenging activities of thiamin and thiamin diphosphate (TDP) were found in some in vitro experiments. Thiamin and TDP caused considerable suppressive effects on superoxide generation in hypoxanthine and xanthine oxidase system which was measured by a sensitive chemiluminescence method using 2-methyl-6-[p-methylphenyl]-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one (MCLA), and their 50% inhibition (IC(50)) values were estimated to be 158 and 56 microM, respectively. They also showed the significant suppression against hydroperoxide generation derived from oxidized linoleic acid which was estimated by aluminum chloride method and their IC(50) values were calculated to be 260 and 46 microM. They further prevented the oxygen radical generation in opsonized zymosan-stimulated human blood neutrophils which was shown by chemiluminescence method using luminol, and their IC(50) values were calculated to be 169 and 38 microM. In contrast, they caused weak but significantly suppressive effects on the hydroxyl radical generation by Fenton reaction which was measured by electric spin resonance (ESR) method, their IC(50) values were calculated to be 8.45 and 1.46 mM respectively. These results strongly suggest a possibility that thiamin and TDP play as radical scavengers in cell-free and cellular systems.
Preventive Medicine Group, Westlake, OH 44145, USA. dlonsdale@@pol.net
Thiamin(e), also known as vitamin B1, is now known to play a fundamental role in energy metabolism. Its discovery followed from the original early research on the 'anti-beriberi factor' found in rice polishings. After its synthesis in 1936, it led to many years of research to find its action in treating beriberi, a lethal scourge known for thousands of years, particularly in cultures dependent on rice as a staple. This paper refers to the previously described symptomatology of beriberi, emphasizing that it differs from that in pure, experimentally induced thiamine deficiency in human subjects. Emphasis is placed on some of the more unusual manifestations of thiamine deficiency and its potential role in modern nutrition. Its biochemistry and pathophysiology are discussed and some of the less common conditions associated with thiamine deficiency are reviewed. An understanding of the role of thiamine in modern nutrition is crucial in the rapidly advancing knowledge applicable to Complementary Alternative Medicine. References are given that provide insight into the use of this vitamin in clinical conditions that are not usually associated with nutritional deficiency. The role of allithiamine and its synthetic derivatives is discussed. Thiamine plays a vital role in metabolism of glucose. Thus, emphasis is placed on the fact that ingestion of excessive simple carbohydrates automatically increases the need for this vitamin. This is referred to as high calorie malnutrition.
Preventive Medicine Group, Westlake, Ohio, USA. dlonsdale@pol.net
Thiamine tetrahydrofurfuryl disulfide (TTFD) is the synthetic counterpart of allithiamine, occurring naturally in garlic. Allithiamine was discovered in Japan in 1951. Its extensive research was reported by a group known as the Vitamin B Research Committee of Japan, and given this name because of its existence in the bulbs of many of the allium species of plants. It was found to be a disulfide derivative of thiamine, produced as a result of enzymatic action on the thiamine molecule in garlic bulbs when the bulb is cut or crushed. Subsequent experimental work in both animals and human subjects revealed that its metabolic effect was much more powerful than the thiamine from which it was derived. Japanese investigators created a number of synthetic forms and investigated their use in a number of human disease conditions. Although some derivatives have been synthesized without a disulfide bond in the molecule, these investigators emphasized that the disulfide was an extremely important part of its biologic action and TTFD is the most modern of the disulfide derivatives. Because at least part of its beneficial effects are the same as water soluble thiamine salts, this review deals first with the clinical uses of thiamine (vitamin B1) in medicine.
Neuroscience. 2004 ;125 (4):833-40
15120844
Cit:5
J Czerniecki,
G Chanas,
M Verlaet,
L Bettendorff,
A F Makarchikov,
P Leprince,
P Wins,
T Grisar,
B Lakaye
Center for Cellular and Molecular Neurobiology, University of Liège, 17 place Delcour, B-4020 Liège, Belgium.
Thiamine triphosphate (ThTP) is found in small amounts in most organisms from bacteria to mammals, but little is known about its physiological role. In vertebrate tissues, ThTP may act as a phosphate donor for the phosphorylation of certain proteins; this may be part of a new signal transduction pathway. We have recently characterized a highly specific 25-kDa thiamine triphosphatase (ThTPase) that is expressed in most mammalian tissues. The role of this enzyme may be the control of intracellular concentrations of ThTP. As the latter has been considered to be a neuroactive form of thiamine, we have studied the distribution of ThTPase mRNA and protein in rodent brain using in situ hybridization and immunohistochemistry. With both methods, we found the strongest staining in hippocampal pyramidal neurons, as well as cerebellar granule cells and Purkinje cells. Some interneurons were also labeled and many ThTPase mRNA-positive and immunoreactive cells were distributed throughout cerebral cortical gray matter and the thalamus. White matter was not significantly labeled. ThTPase immunoreactivity seems to be located mainly in the cytoplasm of neuronal perikarya. Immunocytochemical data using dissociated cultured cells from hippocampal and cerebellum showed that the staining was more intense in neurons than in astrocytes. The protein was rather uniformly located in the perikarya and dendrites, suggesting that ThTP and ThTPase may play a general role in neuronal metabolism rather than a specific role in excitability. There was no apparent correlation between ThTPase expression and selective vulnerability of certain brain regions to thiamine deficiency.
School of Psychological Science, La Trobe University, Bundoora, Australia.
Alcohol can have an effect on almost every cell in the human body and it is becoming increasingly clear that when alcohol is consumed the prior nutritional status of the individual may be an important factor for long-term health. The salt and water hypothesis integrates the biochemical findings from the current alcohol literature and proposes a mechanism by which alcohol consumption prior to food intake may cause a transient alteration in the functioning of the hypothalamic-pituitary-adrenal axis due to an alcohol-induced impairment in electrolyte regulation.
Other papers by authors:Extracts of tissue fluids from a patient with subacute necrotizing encephalomyelopathy inhibit thiamine pyrophosphate-adenosine triphosphate phosphotransferase of rat brain. Brain tissue from the patient, in contrast to normal brain tissue, contained essentially no thiamine triphosphate, although thiamine and its other phosphate esters were present in normal concentrations. These findings suggest a relation between this disease and thiamine triphosphate.
Thiamine and thiamine triphosphate (TTP) values were assayed in various brain regions in 11 controls and 13 patients with subacute necrotizing encephalomyelopathy (SNE, Leigh disease). The TTP values of normal brain were 5% of the total thiamine value. The relative TTP (or % TTP) level was consistently low in the pons, midbrain, and cerebellum of all the SNE brains. Twenty-five percent of the SNE brains had normal TTP levels in the frontal region. The TTP values correlated with the degrees of pathologic involvement in all sampled regions of the brain except the cerebellum. The concentration of thiamine in the mammillary bodies exceeded its concentration elsewhere in both control and SNE brains. The finding of low TTP levels in morphologically abnormal regions supports the hypothesis that TTP deficiency is etiologically related to SNE.
Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA.
Al(2)O(3) and TiO(2) atomic layer deposition (ALD) were employed to develop an ultrathin barrier film on copper to prevent water corrosion. The strategy was to utilize Al(2)O(3) ALD as a pinhole-free barrier and to protect the Al(2)O(3) ALD using TiO(2) ALD. An initial set of experiments was performed at 177 °C to establish that Al(2)O(3) ALD could nucleate on copper and produce a high-quality Al(2)O(3) film. In situ quartz crystal microbalance (QCM) measurements verified that Al(2)O(3) ALD nucleated and grew efficiently on copper-plated quartz crystals at 177 °C using trimethylaluminum (TMA) and water as the reactants. An electroplating technique also established that the Al(2)O(3) ALD films had a low defect density. A second set of experiments was performed for ALD at 120 °C to study the ability of ALD films to prevent copper corrosion. These experiments revealed that an Al(2)O(3) ALD film alone was insufficient to prevent copper corrosion because of the dissolution of the Al(2)O(3) film in water. Subsequently, TiO(2) ALD was explored on copper at 120 °C using TiCl(4) and water as the reactants. The resulting TiO(2) films also did not prevent the water corrosion of copper. Fortunately, Al(2)O(3) films with a TiO(2) capping layer were much more resilient to dissolution in water and prevented the water corrosion of copper. Optical microscopy images revealed that TiO(2) capping layers as thin as 200 Å on Al(2)O(3) adhesion layers could prevent copper corrosion in water at 90 °C for ~80 days. In contrast, the copper corroded almost immediately in water at 90 °C for Al(2)O(3) and ZnO films by themselves on copper. Ellipsometer measurements revealed that Al(2)O(3) films with a thickness of ~200 Å and ZnO films with a thickness of ~250 Å dissolved in water at 90 °C in ~10 days. In contrast, the ellipsometer measurements confirmed that the TiO(2) capping layers with thicknesses of ~200 Å on the Al(2)O(3) adhesion layers protected the copper for ~80 days in water at 90 °C. The TiO(2) ALD coatings were also hydrophilic and facilitated H(2)O wetting to copper wire mesh substrates.
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