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Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A patient with gout and schizophrenia is described who during a schizophrenic paroxysm with paranoid-hypochondriac-hallucinatory syndrome attempted to commit suicide and took 200 tablets milurit (20 g). He developed the picture of acute intoxication with nausea, vomiting, profuse diarrhea, abdominal pain, flushing, temperature, collapse manifestations, hepatomegaly, direct hyperbilirubinemia, elevated transaminase, leukopenia, accelerated ESR. After reanimation and infusion therapy, the patient recovered within 4 days and 2 weeks later all blood indices reached the limits of the norm.
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PMID:[Acute allopurinol (milurit) poisoning]. 402 4

There is evidence that schizophrenia may be related to excess biological activity of dopamine, deficient synthesis of a prostaglandin and to the presence of a normal opioid in excess or of an abnormal opioid. These three groups of observations seem to be interrelated since opioids are able to inhibit the formation of prostaglandin E1 and prostaglandin E1 and dopamine inhibit each other's effects. A low prostaglandin E1 level will therefore produce and apparent dopamine excess. Niacin causes flushing, apparently by stimulating production of prostaglandin E1. Much larger doses of oral niacin are required to produce flushing in schizophrenics than in normal individuals. Most schizophrenics do not flush when given 250 mg orally and this may be a simple biochemically-based test for a major group of schizophrenics.
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PMID:Schizophrenia: a biochemical disorder? 738 16

Clinical definitions of schizophrenia are unreliable and difficult to use. The niacin flush test, which involves prostaglandin-induced vasodilatation, offers a method of exploring essential fatty acid metabolism in schizophrenic patients and may serve to define a subgroup of patients. In a multicentre study of schizophrenic patients with negative symptoms, we have examined the clinical accompaniments of the niacin response. Patients failing to flush with niacin showed significantly reduced levels of arachidonic and docosahexaenoic acids. Conversion from non-flushing to flushing during the 6 month supplementation period was predicted by an increase in arachidonic acid levels in red blood cell membranes irrespective of nature of supplementation. In this study, patients were selected for their negative symptoms and, therefore, it was not surprising that further measures of negative or positive symptoms did not predict flushing. However, an increased score for affective symptoms was significantly associated with a positive flush response. The stability of the niacin test needs to be examined in relation to the periodicity of symptoms in schizophrenia and manic depressive illness. New information on the anandamide system suggests that it may be associated with periodic phenomena and should be investigated in relation to the niacin test.
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PMID:Membrane fatty acids, niacin flushing and clinical parameters. 888 17

The aim of this pilot study was to evaluate a potential skin test for schizophrenia based on the effect of aqueous methyl nicotinate (AMN) on the production of prostaglandin D2 (PGD2) from skin macrophages and the resultant cutaneous capillary vasodilatation. Four concentrations of AMN were applied topically to the forearm skin in patients and controls, and any resulting vasodilatation was rated as redness after 5 min. The test was carried out on 38 patients with schizophrenia diagnosed according to DSM-III-R criteria, and 22 normal control subjects. At all concentrations of AMN, the schizophrenics were highly significantly different from the controls. One concentration gave the greatest degree of differentiation: at this concentration at 5 min, 83% of schizophrenics but only 23% of controls had a zero or minimal response to AMN. The skin flushing seen after oral administration of nicotinic acid is due to the same reaction, and this has been normal in those with affective illness and neurosis; cyclo-oxygenase inhibitors, e.g., aspirin, give a false-positive result (failure of vasodilatation). This result is consistent with the concept of reduced membrane arachidonic acid levels in schizophrenia. This test may contribute to the reliable diagnosis of schizophrenia.
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PMID:Niacin skin flush in schizophrenia: a preliminary report. 951 68

(1) It is possible to investigate aspects of phospholipid-related signal transduction in humans noninvasively using the niacin skin flush test. (2) Patients with schizophrenia have previously been reported to show a reduced flushing response. (3) The aim of this study was to devise a comprehensive index of cutaneous response to the niacin test, incorporating aqueous methyl nicotinate concentration and time, and to test this index in schizophrenia. (4) A discrete approximation to a continuous volumetric index, which we have named the volumetric niacin response (VNR), was devised. Its value was measured in 27 patients with DSM-IV schizophrenia and 26 age- and sex-matched normal controls. (5) The mean value of the VNR in the patients with schizophrenia (16.26) was significantly smaller than that of 26.77 in the normal controls (P<.0004). (6) With a threshold value for the VNR of 21, the test differentiated well between schizophrenia and normal controls (P=.002) with a sensitivity of 78% and a specificity of 65%. (7) The present results confirm that the flushing response is reduced in schizophrenia, and show that calculation of the VNR is an effective means of allowing the total response in different patients or patient groups to be readily compared.
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PMID:A volumetric biochemical niacin flush-based index that noninvasively detects fatty acid deficiency in schizophrenia. 1185 18

Vasodilation induced by methylnicotinate, a fatty acid- and cyclooxygenase-dependent process, is reduced or absent in patients with schizophrenia. This phenomenon has been suggested to be useful as a diagnostic test for the illness. To determine whether reduced flushing is specific to schizophrenia and is caused by a deficiency in membrane fatty acids, the extent of topically applied methylnicotinate-induced vasodilation was measured in 23 subjects with schizophrenia, 20 subjects with bipolar disorder and 34 healthy volunteers along with red cell fatty acid concentrations and measures of clinical severity. Although there was a significant decrease in an estimate of vasodilation (erythema) compared with healthy volunteers in both schizophrenia and bipolar groups, the schizophrenia group responded significantly less than subjects with bipolar disorder. The reduction in the bipolar group was partly due to a delayed vasodilatory reaction, an effect not observed in subjects with schizophrenia. In subjects with schizophrenia, there were no significant correlations between methylnicotinate response and fatty acid concentrations. The authors conclude that the methylnicotinate procedure can differentiate schizophrenia from other serious mental illness. The methylnicotinate insensitivity in schizophrenia, however, is likely to be due to a deficiency in the fatty acid precursors required for the vasodilatory reaction.
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PMID:On the relationship between methylnicotinate-induced skin flush and fatty acids levels in acute psychosis. 1449 9

Niacin (vitamin B3) flushing--a marker of altered prostaglandin signaling--is indirectly linked to the phospholipid-prostaglandin metabolism. Diminished skin flushing was repeatedly found in schizophrenia, but has not been systematically investigated at different stages of disorder as yet. We compared niacin sensitivity of 32 first-episode and 32 multi-episode patients (mainly on stable medication) with age and gender matched healthy controls. Methylnicotinate was applied in three concentrations onto the inner forearm skin. Flush response was assessed in 3 min intervals over 15 min using optical reflection spectroscopy. Whereas first-episode patients showed significantly diminished flush response as compared to controls, comparable differences were not found between multi-episode patients and controls. Comparison of niacin sensitivity at different stages of schizophrenia support the notion of altered prostaglandin signaling primarily at the onset of disorder. Longitudinal studies have to rule out possible long-term effects of neuroleptic medication.
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PMID:Impaired niacin sensitivity in acute first-episode but not in multi-episode schizophrenia. 1588 94

We describe a case of massive oral niacin overdose that resulted in severe persistent hypotension without the manifestation of cutaneous flushing. This case is the highest overdose of niacin reported in the literature to date and the first time severe persistent hypotension has been attributed to niacin. A 56-year-old male with a history of schizophrenia presented to the emergency department after orally ingesting 11,000 mg of niacin. The patient cited an Internet resource that recommended high-dose niacin for therapy of schizophrenia as the reason for his ingestion. He stopped his psychiatric medications several weeks prior to his niacin overdose. At presentation, the patient was alert and normothermic. His pulse was 68 beats per minute and his blood pressure was initially 92/41 mmHg. Hypotension with a blood pressure of 58/40 developed over the next few hours and persisted despite intravenous infusion of over 4 liters of normal saline. The physical exam was otherwise unremarkable, specifically without signs of an allergic reaction or cutaneous flushing. He required intravenous dopamine infusion for 12 hours to support a mean arterial blood pressure greater than 60 mmHg. Evaluation for other etiologies of hypotension was unrevealing. Serum niacin levels were 8.2 ug/ mL and 5.6 ug/mL at 48 and 96 hours post ingestion, respectively, giving an apparent T1/2 of 87 hours. Massive overdose of niacin appears to be capable of causing severe, persistent hypotension in the absence of cutaneous flushing. In this case, the ingestion of a dietary supplement based on Internet advice led to a severe adverse reaction.
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PMID:Treatment advice on the internet leads to a life-threatening adverse reaction: hypotension associated with Niacin overdose. 1649 99

Several observations point to the involvement of disturbed lipid biology in schizophrenia. Reduced response to niacin flushing test, which involves vasodilatation induced by prostaglandin D2 (PGD2), is among the evidences, together with decreased CSF levels of lipocalin-type prostaglandin D2 synthase (PTGDS), the enzyme responsible for the synthesis of PGD2 in the brain. Since PTGDS is also a carrier for lipophilic molecules such as retinoids and thyroid hormones, altered PTGDS levels might influence both PGD2-mediated signaling, and vitamin A and thyroid hormone availability. To test whether genetic variants of PTGDS are involved in the etiology of schizophrenia, we searched for variants in the coding and regulatory regions of the gene. We identified four previously described polymorphisms. Using two case-control samples from Portugal and Brazil, none of the polymorphisms tested was associated with the disease. In addition, no transmission distortion was observed in an independent parents-offspring sample from the Azorean Islands. Our data do not support the involvement of the PTGDS gene in the etiology of schizophrenia.
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PMID:Family-based and case-control studies reveal no association of lipocalin-type prostaglandin D2 synthase with schizophrenia. 1723 May 1

Increasing evidence suggests modulating effects of cannabinoids on time of onset, severity, and outcome of schizophrenia. Efforts to discover the underlying pathomechanism have led to the assumption of gene x environment interactions, including premorbid genetical vulnerability and worsening effects of continuing cannabis use. The objective of this cross-sectional study is to investigate the relationship between delta-9-tetrahydrocannabinol intake and niacin sensitivity in schizophrenia patients and healthy controls. Intensity of niacin skin flushing, indicating disturbed prostaglandin-mediated processes, was used as peripheral marker of lipid-arachidonic acid pathways and investigated in cannabis-consuming and nonconsuming schizophrenia patients and in healthy controls. Methylnicotinate was applied in three concentrations onto the forearm skin. Flush response was assessed in 3-min intervals over 15 min using optical reflection spectroscopy. In controls, skin flushing was significantly decreased in cannabis-consuming as compared to nonconsuming individuals. When comparing the nonconsuming subgroups, patients showed significantly decreased flush response. The populations as a whole (patients and controls) showed an inverse association between skin flushing and sum scores of Symptom Check List 90-R. Results demonstrate an impact of long-term cannabis use on lipid-arachidonic acid pathways. Considering pre-existing vulnerability of lipid metabolism in schizophrenia, observed effects of cannabis use support the notion of a gene x environment interaction.
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PMID:Cannabinoids influence lipid-arachidonic acid pathways in schizophrenia. 1731 20


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