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)

Phencyclidine (PCP)-induced behavior in rats was investigated in water maze and diving behavior tasks. The swimming and diving latencies of PCP-treated groups placed in a water maze apparatus were gradually shortened, and prolonged, respectively, while rats in a control group performed well. In all rats, stereotyped behavior and hyperlocomotion were absent. We propose that this animal model induced by lower doses of PCP may be useful for further studies to research schizophrenia.
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PMID:A rat model of phencyclidine psychosis. 796 34

Polydipsia among chronic psychiatric patients is poorly understood and underdiagnosed. It may have three stages: simple polydipsia, polydipsia with water intoxication, and physical complications. Epidemiological surveys have used staff reports and polyuria measures to identify polydipsic patients. Water intoxication has been screened by chart review, weight, or serum sodium data. According to these surveys, polydipsia, not explained by medically induced polyuria, may be present in more than 20% of chronic inpatients. Up to 5% of chronic inpatients had episodes of water intoxication although mild cases may have been missed. Single time point surveys show that 29% of polydipsic patients had presented water intoxication. Methodologically limited clinical studies suggest that polydipsia with water intoxication rather than simple polydipsia may be associated with poor prognosis in schizophrenia. Epidemiological surveys found polydipsia with water intoxication to be associated with chronicity, schizophrenia, smoking, some medications, male gender, and white race. New pathophysiological models need to elucidate these findings.
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PMID:Polydipsia and water intoxication in psychiatric patients: a review of the epidemiological literature. 801 88

In this study, positron emission tomography (PET) was used to evaluate cortical control of saccades. Regional cerebral blood flow (rCBF) patterns demonstrated by 15O water PET during saccadic task performance were tested in 13 normal volunteers and 20 ICD-9 schizo phrenics (10 unmedicated and 10 medicated). The following 3 saccadic tasks, which were controlled for sensory input and oculomotor output, were applied: (1) reflexive saccade = visually guided saccade, (2) volitional saccade = visually guided saccade with distracting stimuli, and (3) memory guided saccade. Schizophrenics lacked the frontal eye field (FEF) activation during every saccadic task. The left dorsolateral prefrontal cortex (DLPFC) was activated during volitional saccade only in normal controls. The rCBF of posterior parietal cortex increased in parallel with that in the DLPFC. These findings suggest functional hypofrontality in schizophrenia and the left DLPFC-PPC's crucial role in saccade against distracting stimuli and its dysfunction in the disease.
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PMID:Cortical control of saccade in normal and schizophrenic subjects: a PET study using a task-evoked rCBF paradigm. 805 18

Disturbances of water homeostasis have frequently been reported in schizophrenia. Water homeostasis is regulated by arginine vasopressin (AVP), the renin-angiotensin system and natriuretic hormones. The aim of this study was to determine the activity of the central renin-angiotensin system in schizophrenia by measuring levels of angiotensin-converting enzyme (ACE) in the cerebrospinal fluid (CSF) and blood in 14 in-patients with schizophrenia on neuroleptic medication and in 9 healthy volunteers. The levels of CSF ACE were significantly higher in the schizophrenia group. There were no correlations between CSF ACE and gender, age, age at first episode, duration of illness, term of hospitalization or neuroleptic dosage. No correlations between CSF ACE and serum ACE were found in either group. The authors suggest an activated central renin-angiotensin system in schizophrenia at least during antipsychotic drug treatment, which may cause 'psychogenic' polydipsia in some patients. ACE and the brain renin-angiotensin system may also play a role in the regulation of neuron growth and differentiation in schizophrenia.
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PMID:Elevated angiotensin-converting enzyme (kininase II) in the cerebrospinal fluid of neuroleptic-treated schizophrenic patients. 809 92

To investigate a possible association between disordered water homeostasis and cognitive impairment in schizophrenia, neuropsychological tests were applied to 16 schizophrenic patients with severely deranged water homeostasis and to 16 matched schizophrenic controls. The patients with disordered water homeostasis tended to obtain poorer scores than the controls throughout, the differences being statistically significant for two of the tests (Wechsler Memory Scale Visual Reproduction and Trial Marking Test part A). These results were not ascribable to differences in the duration of the illness, premorbid IQ, medication, or electroconvulsive therapy received, or prominence of any particular symptoms. The results suggest the co-existence of disordered water homeostasis and cognitive impairment in a subset of schizophrenic patients.
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PMID:Disordered water homeostasis and cognitive impairment in schizophrenia. 829 91

Diminished gating of the auditory evoked response to repeated stimuli is a psychophysiological defect associated with schizophrenia and several other psychiatric illnesses. The P50 wave of the auditory evoked response to the second of paired stimuli is decreased in most normal subjects, whereas many psychotic subjects show significantly less decrement. The aim of this experiment was to test whether the cold-pressor test, which causes transient distress and pain accompanied by increased sympathetic activity, also causes a transient impairment in P50 auditory sensory gating in normal control subjects. Ten normal control subjects with normal gating of the P50 response immersed their hands in an ice water bath for 2 min. This cold-pressor test diminished P50 auditory gating in nine of these subjects, although the degree of impairment was highly variable among subjects. The impairment in gating was transient, with partial resolution by 30 min. The cold-pressor test was subjectively viewed as painful and also caused blood pressure to increase. Thus, a transient stressor can impair P50 auditory gating in some subjects.
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PMID:Transient impairment in P50 auditory sensory gating induced by a cold-pressor test. 838 6

The mesocortical dopamine system is thought to play an important role in the etiology of the stress response. Dopamine (DA) has been shown to accumulate in the rat frontal cortex in response to a wide variety of stressors. Diazepam, an anxiolytic benzodiazepine, can reverse the effects of stress on cortical DA. We investigated the effects of acute and chronic diazepam administration on immobilization stress-induced changes of the DA system in the frontal cortex of the rat. In the first study, 2.5 mg/kg diazepam was administered 20 min prior to 40 min of immobilization stress. Acute diazepam significantly reduced basal levels of extracellular DA and antagonized the stress-induced increase in cortical DA when compared to untreated stressed rats. Acute diazepam did not significantly effect extracellular DOPAC. In the second study, an experimental group of rats was given approximately 2 mg/kg/day diazepam in their drinking water for 3 weeks. This treatment significantly reduced anxiety as assessed by a staircase test for anxiety. Chronic diazepam had no effect on basal levels of cortical DA. However, chronic diazepam treatment also attenuated stress-induced increases in extracellular DA when compared to untreated stressed control rats. Chronic diazepam did not affect stress-induced changes in DOPAC but it did antagonize the effects of stress on HVA. Thus, acute and chronic diazepam treatment can antagonize stress-induced activation of the mesocortical DA system. It is proposed that this effect is produced through an enhancement of GABAergic neurotransmission by diazepam. The role of the dopaminergic system during stress, anxiety, and schizophrenia is discussed.
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PMID:The effect of acute and chronic diazepam treatment on stress-induced changes in cortical dopamine in the rat. 858 19

A 28-year-old woman, treated for schizophrenia, developed severe hypotonic hyponatremia (serum Na: 109 mEq/L) after several days of compulsive water drinking. The patient was admitted in a coma and required intensive supportive therapy. Rhabdomyolysis quickly followed with high serum creatine phosphokinase levels and myoglobinuria. A high volume alkaline diuresis was initiated. Renal failure or compartment syndrome did not complicate the clinical picture. The mechanisms causing water intoxication and hyponatremia are discussed as are the possible pathogenetic explanations behind acute hyponatremia and rhabdomyolysis.
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PMID:Case report: severe hyponatremia after water intoxication: a potential cause of rhabdomyolysis. 870 73

This cross-sectional survey attempts to establish the prevalence of polydipsia and water intoxication at a state hospital (N = 360) using staff diagnosis, specific gravity of the urine (SPGU), weight changes, and chart review. There were 150 [42%, 95% confidence interval (CI) 37-47%] patients diagnosed as polydipsic by the staff or by SPGU. At least 93 (26%, CI 21-30%) had primary polydipsia not explained by other causes. Chart review identified 17 (5%, CI 3-7%) patients with a history of water intoxication. Using a case-control study design, schizophrenia, extended duration of hospitalization, and heavy smoking were associated with primary polydipsia in a logistic regression analysis (respective odds ratios were 1.6, 1.8, and 3.6). All patients with a history of water intoxication were Caucasian (versus 83% in those without a history) and had significantly more extended hospitalizations (94 vs. 49%). Future case-control studies should combine longitudinal identification of true cases and controls and exhaustive collections of clinical information in a standardized way.
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PMID:Polydipsia and water intoxication in a long-term psychiatric hospital. 878 Aug 52

This report describes two cases of schizophrenia inpatients with polydipsia, intermittent hyponatremia, and water intoxication. Case 1, a 38 year-old male, developed polydipsia after seven years duration of schizophrenia, with a daily intake of water of more than 10 liters as a result of auditory hallucination suggestion. Nocturnal hyponatremia, agitation and exacerbation of psychosis were noted during admission. After 12 treatments of electroconvulsive therapy, the symptoms of psychosis and polydipsia declined. Case 2, a 42 year-old male, had also been a case of schizophrenia for about twenty years, and developed polydipsia with more than 5 liters of daily water intake in a chronic psychiatric hospital for a period of 5 years schizophrenia. He claimed that he enjoyed the pleasure of drinking water. The symptom of water intoxication had been noted intermittently in the past year, leading to at least two seizures. Finally the patient was transferred to our ward due to agitated mood, self-destructive behavior, consciousness loss, and motor weakness. The clinical features, differential diagnosis and treatment concept of polydipsia and water intoxication were also discussed in context.
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PMID:[Polydipsia and water intoxication in schizophrenia patients: report of two cases]. 881 59


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