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Biomedical subjects

W B Lawson

Publications and source records attributed to W B Lawson.

At least 19 recordsLinked to original sources
PubMed1998

Regional proton magnetic resonance spectroscopy in schizophrenia and exploration of drug effect.

Schizophrenia is a disorder with an unclear pathophysiology, despite numerous attempts to elucidate its etiology. We have employed proton magnetic resonance spectroscopy in vivo to explore the neurochemistry of several brain regions (left frontal and temporal cortices, left basal ganglia, and left and right thalamus) in patients with schizophrenia and in normal control subjects. We have also examined patients in different medication states. A trend toward a decreased level of inositol/creatine was found in the left temporal lobe of patients with schizophrenia, as was a trend toward a reduced level of N-acetylaspartate/creatine in the left thalamus of patients. In schizophrenic patients treated with atypical antipsychotics, decreased levels of choline were found in the left basal ganglia, while increased levels of N-acetylaspartate were found in the left frontal cortex. These results suggest altered metabolism in patients with schizophrenia, and imply that further study is needed to clarify the effects of the more recently available antipsychotics.

Adult↗
PubMed1996

The relationship between urine excretion and biogenic amines and their metabolites in cerebrospinal fluid of schizophrenic patients.

Concentrations of norepinephrine and metabolites of biogenic amines were measured in lumbar cerebrospinal fluid of 30 patients with chronic schizophrenia, nine of whom were polyuric. The mean level of norepinephrine was two-fold higher (p < or = 0.025) in polyuric patients than in patients whose excretion of urine was within the normal range. CSF levels of histamine's primary metabolite, tele-methylhistamine, an index of brain histaminergic activity, were positively correlated (p < 0.005) with daily urine volume. These results are consistent with the known influence of norepinephrine and histamine on fluid regulation and suggest that norepinephrine and histamine may be involved in psychogenic polydipsia-polyuria in schizophrenic patients.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1996

pros-Methylimidazoleacetic acid in cerebrospinal fluid of patients with chronic schizophrenia: relationships to ratings of symptoms, ventricular brain ratios, and rates of urine excretion.

Concentrations of pros-methylimidazoleacetic acid (p-MIAA) were measured in cerebrospinal fluid of 30 patients with chronic schizophrenia. Levels of p-MIAA correlated negatively with mean scores of the Psychiatric Symptom Assessment Scale for positive symptoms (r = -0.48), but not negative symptoms, and with ventricular brain ratios (r = -0.48). Patients with abnormal ventricular enlargements had much lower concentrations of p-MIAA than those with normal ventricles. These results suggest that processes that reduce accumulation of p-MIAA in CSF may be associated with increased severity of symptoms among patients with chronic schizophrenia.

Adult↗
PubMed1996

Clinical issues in the pharmacotherapy of African-Americans.

African-Americans have poorer outcomes than Caucasians in general health and mental health systems possibly due to lesser access to services, particularly pharmacotherapy in mental health systems. A review of the literature revealed that African-Americans are more likely to be overdiagnosed as having a psychotic illness. Consequently, antipsychotic medication may be overprescribed. Poorer patient compliance, delays in seeking treatment, higher prescribed dosages, and more PRN use of medication by providers add to racial differences in treatment outcome. African-Americans also are reported to be at a greater risk than Caucasians for medication side effects and adverse consequences. These problems may be exacerbated by ethnic differences in pharmacokinetics. Newer pharmacological agents may be more helpful for minorities because they are better tolerated, produce fewer side effects, and have better efficacy. However, African-Americans still are underrepresented in clinical trials and have limited access to these agents. Race and ethnicity need to be considered in maximizing pharmacotherapy and to better understand treatment outcome.

Black or African American↗
PubMed1994

Clinical correlates of body weight changes in schizophrenia.

Body weight was examined in chronic schizophrenic patients. Underweight medicated patients had normal ventricular brain ratios (VBRs) on CT. Overweight patients had both normal and abnormal VBRs. Weight decreased during neuroleptic withdrawal; caloric intake and weight increased when neuroleptics were reinstituted. Weight gain on neuroleptics correlated with symptom improvement independent of VBR or gender. Weight changes and psychosis in schizophrenia may be mediated by similar neurochemical systems.

Adult↗
PubMed1992

Fluid intake patterns in schizophrenia and normal controls.

1. Patterns of fluid intake and urine output was examined in schizophrenia and normal controls. 2. Fluid intake and urine output were significantly higher in schizophrenic patients. 3. Bouts of drinking correlated significantly with fluid intake but did not differ significantly between schizophrenic patients and normal controls. 4. Schizophrenic patients drink more per bout compared to normal controls.

Adult↗
PubMed1992

The dexamethasone suppression test as an adjunct in diagnosing depression.

Historically, affective disorders have been underdiagnosed among minorities, while schizophrenia is often overdiagnosed. Cultural differences in symptomatology, such as increased reports of auditory hallucinations, or language differences reportedly contribute to misdiagnoses in Hispanics. Consequently, we performed a thorough evaluation of Hispanic patients with a history of schizophrenia who remained diagnostic enigmas. Evaluation included the use of a Spanish-speaking interpreter, strict adherence to criteria of the Diagnostic and Statistical Manual of Mental Disorders, third edition (revised), and the dexamethasone suppression test. Five patients met criteria for major depression, and all but one were properly classified using the dexamethasone suppression test. Careful evaluation is needed with appropriate cultural and diagnostics support to avoid missing depression in Hispanics. The dexamethasone suppression test may be a useful adjunct in some difficult-to-diagnose patients.

Adult↗
PubMed1991

Adjunctive clonazepam in the treatment of chronic schizophrenia.

Clonazepam was added to the neuroleptic regimen of 3 treatment-resistant schizophrenic patients with schizoaffective features. Manic symptoms improved but returned following discontinuation of clonazepam. The drug appears to benefit positive psychotic symptoms but worsens negative symptoms.

Adult↗
PubMed1989

RBC and plasma choline in neuroleptic-treated schizophrenic patients.

We measured red blood cell (RBC) choline and plasma choline concentrations in 27 chronic schizophrenic inpatients and 23 normal controls. Both blood choline measures had a significant test-retest reliability in patients whose neuroleptic status remained unchanged over 1 month. RBC choline concentration was significantly lower in patients medicated with neuroleptics and cogentin. Patients with a low RBC choline and a low RBC/plasma choline ratio were on significantly higher doses of medication and had higher scores on the hostility/suspiciousness subscale of the Brief Psychiatric Rating Scale. RBC choline increased when neuroleptics were discontinued. Blood choline measures were also compared among medication-free schizophrenic patients, inpatients with other diagnoses, and normal controls. No significant differences were seen among these groups for any choline measure, although the schizophrenic patients showed greater variability. Medication-free schizophrenic patients with such clinical factors as tardive dyskinesia and abnormalities on computed tomography contributed to this variability. Age was positively correlated with plasma choline.

Adult↗
PubMed1988

Schizophrenic dementia. Clinical and computed axial tomography correlates.

Twenty-seven chronic schizophrenic patients and nine other psychiatric patients closely matched in education were compared on the Halstead-Reitan Battery and the Wechsler Adult Intelligence Scale (WAIS). The schizophrenic patients as a group showed significantly poorer performance on the WAIS (full scale: X +/- SD, 92.9 +/- 2.9 vs. 110.8 +/- 2.1, p less than .002) and the Halstead-Reitan Battery (HRB; Average Impairment Range = 2.1 +/- .2 vs. 1.12 +/- .06, p less than .003). In addition the schizophrenic patients did significantly worse than did nonschizophrenic patients on all WAIS subtests and scored in the impaired range on most HRB subtests. Computed axial tomography scans revealed large ventricles on nine schizophrenic patients and cortical atrophy on three others. Among schizophrenics, the enlarged ventricle group consistently scored the worst. No relationship was seen between neuropsychological test performance and degree of ongoing psychopathology as measured by the Brief Psychiatric Rating Scale. These findings are consistent with previous reports of cognitive impairment in schizophrenia and are discussed in terms of regional localization. They provide additional evidence that the impairment is related to the disease process and that structural abnormalities are associated with the more severe condition.

Adult↗
PubMed1987

Preliminary evidence of reduced combined output of dopamine and its metabolites in chronic schizophrenia.

The mean combined total body excretion of dopamine (DA) and its metabolites, measured by summing the molar excretion of DA and its metabolites in 24-hour urine samples (Sum DA), was reduced in 20 patients with schizophrenia who had not been receiving medication for at least two weeks. These patients were relatively resistant to treatment, as they were unable to live independently outside institutional settings despite conventional neuroleptic therapy. In contrast, sum norepinephrine (Sum NE), measured by summing the molar excretion of NE and its metabolites, was not reduced. These results are highlighted by expressing the data in terms of the ratio of Sum DA/Sum NE. Patients with schizophrenia had a significantly lower ratio. Treatment with haloperidol normalized the low ratio. Urinary excretion of 5-hydroxyindoleacetic acid was normal in the schizophrenic patients. These results suggest that chronic schizophrenia is more likely to be associated with a low rather than a high state of DA activity.

Adult↗
PubMed1986

Racial and ethnic factors in psychiatric research.

Although historically research findings about racial and ethnic issues were all too often used to support prevailing concepts of racial inferiority, in recent years racial and ethnic factors have frequently been ignored. However, current findings suggest that racial and ethnic differences exist in the symptom presentations of psychiatric disorders. Significant racial differences have been noted among proposed biological markers for various psychiatric disorders, such as serum creatinine phosphokinase, platelet serotonin, and HLA-A2. Racial and ethnic differences in response to psychotropic medication, such as higher blood levels found among Asians, affect dosage requirements and potential side effects. All of these developments underline the importance of considering ethnic and racial factors in psychiatric research.

Black or African American↗
PubMed1985

Prothrombin time proficiency testing: a robust grading method.

A robust two-way analysis of variance technique was applied to determine simultaneously the effects of method and thromboplastin on prothrombin time. A new approach to outlier detection for two-way analysis of variance was used. Focusing on the underlying error structure improved the uniformity of the grading procedure in the hematology proficiency testing program of the New York State Department of Health. The logarithm-transformed scale produced constancy of error variance and resulted in uniformity of the acceptable spread of data. The common variance was lower than that obtained by previous methods and allowed for a narrower acceptable range of reported prothrombin times by reducing the inflated standard deviation, thus improving the efficiency of the grading procedure. For proficiency testing, no advantage was found in the use of either a common thromboplastin or freeze-dried, coumadinized patient plasmas rather than artificially depleted commercial plasmas, except for special purposes.

Automation↗