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)

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

The aim of this study was to confirm a recent report that the non-invasive niacin skin flush test can be used to demonstrate impaired arachidonic acid-related signal transduction in schizophrenia. The response to topical aqueous methyl nicotinate solution was recorded at five-minute intervals over 20 minutes in 21 patients with schizophrenia, and in 20 age- and sex-matched normal individuals with no personal or family psychiatric history. The response was significantly lower in the patients with schizophrenia. At a concentration of 0.001 M, at the 15-minute timepoint, only two out of the 21 patients with schizophrenia showed a response, compared with 15 out of 20 of the controls (p < 0.00002), giving a sensitivity of the niacin skin test of 90% and a specificity of 75%. Our results are therefore consistent with the previous published report and suggest that this test may be useful clinically in the diagnosis of schizophrenia.
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PMID:The niacin skin flush test in schizophrenia: a replication study. 1150 Dec 24

(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

The aim of this study was to test the hypothesis that autism (a neurodevelopmental disorder of unknown etiology) is associated with altered phospholipid-related signal transduction using the niacin skin flush test. This is the first reported use of this test in this disorder. The response to topical aqueous methyl nicotinate solution was recorded at 5-min intervals over 20 min in eight patients with autism and in 16 age- and sex-matched normal individuals with no history of this or any other major neuropsychiatric disorder. There was no significant difference between the mean volumetric niacin response (VNR) (+/- S.E.M.) in the patients with autism, 27.0 (+/- 2.2) mol s l(-1), and the mean VNR of 27.6 (+/- 2.4) mol s l(-1) in the control group (P>.8). Therefore, there appears to be no evidence of altered phosopholipid-related signal transduction in autism as assessed by this test. Furthermore, since the VNR is reduced in a related disorder, schizophrenia, these results suggest fatty acid abnormalities in autism are likely to differ from those in schizophrenia.
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PMID:Normal phospholipid-related signal transduction in autism. 1250 30

The normal vasodilatory response to topically applied methylnicotinate has been reported to be absent or reduced in patients with schizophrenia, a finding thought to be related to aberrant phospholipid metabolism. Previous studies have however failed to measure vasodilation using a direct and objective method. In addition, it is unknown whether methylnicotinate insensitivity is specific to schizophrenia. To address these issues we compared the magnitude of methylnicotinate-induced vasodilation in chronically ill patients with schizophrenia (SCZ) (n=27) or bipolar disorder (BP) (n=26) to that in healthy controls (n=32). Blood flow was monitored using laser Doppler flowmetry. Vasodilatory response to 1 and 10 mM methyl nicotinate was markedly and significantly reduced in patients with schizophrenia compared to that in subjects with bipolar disorder and healthy controls. In conclusion, reduced methyl nicotinate response in schizophrenia has been demonstrated using an objective measure of vasodilation. Our data further support the potential utility of this measure as a diagnostic marker for schizophrenia.
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PMID:Reduced vasodilatory response to methylnicotinate in schizophrenia as assessed by laser Doppler flowmetry. 1505 78

The niacin skin test reflects a flush and oedema owing to the production of prostaglandin D2 from arachidonic acid. A diminished response may indicate abnormalities in the phospholipid metabolism, which has been shown in schizophrenia. There is evidence that dyslexia might also involve phospholipid abnormalities, therefore we examined the skin response in 51 dyslexics and 45 controls. Four concentrations of aqueous methyl nicotinate were applied topically to the forearm. Flushing was rated using a seven-point scale at 3 min intervals over 21 min. Repeated measures ANOVA for the four concentrations across all seven time-points showed no significant effect of subject group, but when analyses were confined to the first 9 min, flushing was reduced in dyslexics. Significant group differences were also found for the lowest niacin concentration (0.0001M) across six out of seven time-points. The results indicate a slightly reduced and delayed response to niacin in dyslexia.
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PMID:Niacin skin test response in dyslexia. 1789 71