Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In an aseptic microbiological assay of folate compounds and their breakdown compounds, using Lactobacillus casei, Streptococcus faecalis, and Pediococcus cerevisiae, 4a-hydroxy-5methyl-4,5,6,7-tetrahydrofolate and 5-methyl-5,8-dihydrofolate were inactive under all conditions to all three organisms and 5-methyl-5,6-dihydrofolate was inactive unless ascorbate was present in the incubation medium, and then only to L. casei. 5-Methyltetrahydrofolate was active only for L. casei, and activity in purified samples to S. faecalis was due to trace amounts of folic acid. Analysis of S. faecalis values in the serum in normal subjects and in patients with various disorders showed that levels of 10-formyltetrahydrofolate are raised in coeliac disease, leukaemia, rheumatoid arthritis, and schizophrenia. 5-Methyltetrahydrofolate is readily absorbed by normal human subjects and by patients with pernicious anaemia but poorly absorbed by patients with coeliac disease or leukaemia. 5-Methyl-5,6-dihydrofolate was quickly absorbed by normal human subjects, being reflected by a considerably raised level of 5-methyltetrahydrofolate in serum when sodium bicarbonate was given by mouth before the 5-methyl-5,6-dihydrofolate. These higher levels were comparable to those in patients with pernicious anaemia after oral administration of 5-methyl-5,6-dihydrofolate. Oral 5-methyl-5,8-dihydrofolate and 4a-hydroxy-5-methyl-tetrahydrofolate did not appear as microbiologically active folates in the serum. The findings of this study suggest that the availability for biological utilisation of the major dietary folate compounds will depend on the amount of gastric acidity and of ascorbate in the intestinal chyme. Many may be unavailable for metabolic utilization in the body.
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PMID:Serum folates in man. 40 3

Schizophrenic patients have low concentrations of PGE-1, n-6 fatty acids, vitamin C and zinc, elevated brain levels of dopamine and high plasma levels of interleukin-2 receptors (IL-2R). IL-2R plasma titers can be raised in celiac patients by administering wheat. These findings are both consistent with and supportive of the GI T-lymphocyte theory of schizophrenia.
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PMID:The GI T-lymphocyte theory of schizophrenia: some new observations. 156 3

Vitamin C status was determined in schizophrenic subjects using fasting plasma levels and the urinary dose response after an oral load of 1.0 g ascorbic acid. The study was carried out in 20 schizophrenic patients and 15 controls with the diagnosis of neurosis who were on the same hospital diet for at least 2 months. The schizophrenic subjects had significantly lower fasting plasma vitamin C levels (P less than 0.05) and 6-h urinary vitamin C excretion after an ascorbic acid load test (P less than 0.01). Since urinary vitamin C excretion in both groups was significantly associated with differences in fasting vitamin C plasma levels (P less than 0.001), a new group of 15 schizophrenics and 15 controls was supplemented with 70 mg of ascorbic acid daily for 4 weeks in order to optimize and standardize their vitamin C plasma levels before the ascorbic acid loading test. The results showed that after 4 weeks of supplementation the average fasting plasma vitamin C levels were almost identical in both examined groups, but the urinary vitamin C excretion was again significantly lower in schizophrenic patients (P less than 0.05). These results are in agreement with the hypothesis that schizophrenia may be associated with impaired ascorbic acid metabolism.
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PMID:Plasma levels and urinary vitamin C excretion in schizophrenic patients. 379 23

Deficiencies of specific vitamins produce consistent symptoms of psychiatric disorder. Thiamine deficiency, which is common in alcoholism, can produce confusion and psychotic symptoms, in addition to neurological signs. Vitamin B12 and folate deficiency may contribute symptoms of disorientation, depression or psychosis; their measurement is a part of routine dementia work-ups. Pyridoxine deficiency results in seizures, although the effects of exogenously administered pyridoxine are not clearly understood in depression and anxiety - the disorders in which it is most frequently used clinically. The use of vitamins has been most prominent in psychiatry in the treatment of schizophrenia, where large doses of nicotinic acid were initially given alone and later combined with other vitamins and minerals. Several theoretical models were described to support the use of vitamins in schizophrenia. These included: the parallels of schizophrenia to the psychiatric symptoms of pellagra; hypotheses of a defect in adrenaline metabolism; and the accumulation of psychotoxic substances which produce psychotic symptoms. Initially, positive results were reported over 30 years ago, but have not been replicated by thorough investigations. An extensive series of comprehensive placebo-controlled trials failed to show efficacy for any of the vitamin therapies tested. Although clearly less effective than antipsychotic drug treatment, vitamin therapy is not without risks - adverse effects have been reported with nicotinic acid, pyridoxine and vitamin C.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Vitamins in psychiatry. Do they have a role? 389 44

Vitamins are a group of organic compounds occurring naturally in food and are necessary for good health. Lack of a vitamin may lead to a specific deficiency syndrome, which may be primary (due to inadequate diet) or secondary (due to malabsorption or to increased metabolic need), and it is rational to use high-dose vitamin supplementation in situations where these clinical conditions exist. However, pharmacological doses of vitamins are claimed to be of value in a wide variety of conditions which have no, or only a superficial, resemblance to the classic vitamin deficiency syndromes. The enormous literature on which these claims are based consists mainly of uncontrolled clinical trials or anecdotal reports. Only a few studies have made use of the techniques of randomisation and double-blinding. Evidence from such studies reveals a beneficial therapeutic effect of vitamin E in intermittent claudication and fibrocystic breast disease and of vitamin C in pressure sores, but the use of vitamin A in acne vulgaris, vitamin E in angina pectoris, hyperlipidaemia and enhancement of athletic capacity, of vitamin C in advanced cancer, and niacin in schizophrenia has been rejected. Evidence is conflicting or inconclusive as to the use of vitamin C in the common cold, asthma and enhancement of athletic capacity, of pantothenic acid in osteoarthritis, and folic acid (folacin) in neural tube defects. Most of the vitamins have been reported to cause adverse effects when ingested in excessive doses. It is therefore worthwhile to consider the risk-benefit ratio before embarking upon the use of high-dose vitamin supplementation for disorders were proof of efficacy is lacking.
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PMID:Vitamin therapy in the absence of obvious deficiency. What is the evidence? 623 Feb 19

The height and weight were measured and the total fat and fat-free mass were estimated in 1123 patients in a mental hospital. The results were compared with the reported values in healthy persons. The young patients weighed the same as young healthy persons whereas the average weight in the elderly patients was much less than healthy elderly persons. In the elderly women patients, this difference in weight was much greater in those with dementia than in those with affective disorders or schizophrenia. The difference in weight was not related to the duration of stay in hospital, and there was no evidence that it was due to malnutrition. The lower weight may therefore by a marker for those persons likely to need institutional care rather than the result of loss of weight. A minority of the elderly patients, particularly the ill and immobile, had one of the biochemical markers of malnutrition, low plasma concentrations of either albumin or vitamin C or vitamin D. On average, these patients weighed less and had less body fat than the others. These patients may be the high-risk group for nutritional deficiency but there was no evidence that any of them had a clinically significant nutritional problem.
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PMID:The body composition of the chronic mentally ill. 716 Nov 39

The recent finding that dendritic spines (on which 90% of all excitatory synapses on pyramidal cells are formed) are not permanent structures but are continually being formed and adsorbed has implications for the present theoretical basis of neurocomputation, which is largely based on the concept of fixed nerve nets. This evidence would tend to support the recent theories of Edelman, Freeman, Globus, Pribram and others that neuronal networks in the brain operate mainly as nonlinear dynamic, chaotic systems. This paper presents a hypothesis of a possible neurochemical mechanism underlying this synaptic plasticity based on reactive oxygen species and toxic 0-semiquinones derived from catecholamines (i) by the enzyme prostaglandin H synthetase induced by glutamatergic NMDA receptor activation and (ii) by reactive nitrogen species derived from nitric oxide in a low ascorbate environment. A key factor in this neuromodulation may be the fact that catecholamines are potent antioxidants and free radical scavengers and are thus able to affect the redox mediated balance at the glutamate receptors between synapse formation and synapse removal that may be a key factor in neurocomputational plasticity. But catecholamines are also easily oxidized to neurotoxic 0-semiquinones and this may be relevant to the pathology of several diseases including schizophrenia. The relationship between dopamine release and positive reinforcement is relevant to this hypothesis.
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PMID:The biochemical basis of synaptic plasticity and neurocomputation: a new theory. 914 26

This paper reviews what is currently known about the redox state of the glutamate synapse and its possible role in modulating synaptic plasticity and thus learning and neurocomputation. The hypothesis is presented that the growth or pruning of the synaptic spine is controlled in part by the balance in the synapse between neurodestructive pro-oxidants (e.g., nitric acid radical and hydrogen peroxide) and neuroprotective antioxidants (e.g., ascorbate and carnosine). In addition, there may be a role for catecholamines, in particular dopamine, related to its role in reinforcement signalling. Activation of the dopamine D2 receptor induces the synthesis of an antioxidant enzyme, possibly catalase. Dopamine may also affect the redox balance in the glutamate synapse directly by diffusion from the adjacent dopaminergic bouton-en-passage. Catecholamines are powerful antioxidants, scavengers of free radicals and iron chelators. Catecholamine-iron complexes are potent dismuters of superoxide ions. Additional agents participating in spine pruning may be neurotoxic catecholamine o-quinones present in the brain. This system may be at fault in schizophrenia and Parkinson's disease. Experiments to test the hypothesis are suggested.
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PMID:Redox mechanisms at the glutamate synapse and their significance: a review. 1032 73

This review covers certain novel aspects of catecholamine signaling in neurons that involve redox systems and synaptic plasticity. The redox hypothesis suggests that one important factor in neurocomputation is the formation of new synapses and the removal of old ones (synaptic plasticity), which is modulated in part by the redox balance at the synapse between reactive oxygen species (ROS) (such as hydrogen peroxide and the nitric oxide radical) and neuroprotective antioxidants (such as ascorbate, glutathione, and catecholamines). Catecholamines, in particular dopamine, which signals positive reinforcement, may play a key role in this activity. Dopamine has powerful antioxidant properties by several separate mechanisms-direct ROS scavenging, activation of the synthesis of antioxidant proteins, and possibly via dismuting complexes with iron inside endosomes or in catecholaminergic synaptic vesicles. This may contribute to synaptic growth and reinforcement-directed learning. On the other hand, catecholamines are easily oxidized to toxic quinones on the neuromelanin pathway. This might contribute under certain circumstances to synaptic deletion. Evidence is presented that abnormalities in this system may contribute to the pathogenesis of Parkinson's disease and schizophrenia.
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PMID:Redox aspects of signaling by catecholamines and their metabolites. 1122 69

Tardive dyskinesia caused by antipsychotic treatment is a severe problem not only in the management of schizophrenia, but also of affective disorders. Vitamin E monotherapy has been used in schizophrenic patients with tardive dyskinesia. Pharmacologists warn against high dosage of vitamin E because of its pro-oxidative effects on low-density lipoprotein with consecutive cardiac risks. Addition of vitamin C probably reduces this risk because of its interactions with vitamin E, i.e. vitamin C reduces vitamin E radicals formed when vitamin E scavenges the oxygen radicals. We have therefore tested the safety and efficacy of combining vitamin C and E in a sample of patients with affective disorders and tardive dyskinesia who had previously been treated with antipsychotics due to psychotic symptoms. In all 6 patients, a reduction of tardive symptomatology was seen. In our sample, no side effects were observed. Further studies on this combination therapy are suggested.
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PMID:Severe tardive dyskinesia in affective disorders: treatment with vitamin E and C. 1257 30


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