PubMed Health⌕ Search

Biomedical subjects

H C Chui

Publications and source records attributed to H C Chui.

At least 55 records · Page 3Linked to original sources
PubMed1989

Multicenter trial of naloxone in Alzheimer's disease.

In a double-blind, placebo-controlled, crossover study of intravenously administered naloxone hydrochloride, 54 subjects with clinically ascertained Alzheimer's disease tested at three university centers showed no significant improvement in neuropsychological performance after 1-mg or 10-mg doses; 15 patients at 1 center were similarly unimproved after receiving 30 mg naloxone (single blind). Findings fail to support claims that naloxone monotherapy ameliorates cognitive impairments of Alzheimer's disease.

Adult↗
PubMed1989

Alzheimer's dementia: performance on parallel forms of the dementia assessment battery.

Fifty-four patients with Alzheimer's disease performed on the Dementia Assessment Battery that comprised of finger tapping, forward digit span, naming, verbal memory, visual memory, Token Test, digit cancellation, word-list generation, symbol-digit substitution, and copying geometric designs. Four forms of the battery were administered at weekly intervals. The equivalence of the forms, the relative difficulty of the tests, retest reliability, and factorial composition of the battery are presented. Performance improved with repetition. Impairments in visuo-spatial and verbal abilities were independent of each other. The fragility of the patients' working memory was identified as a main cause for their poor recall. The importance of "component analysis" in individual assessment is illustrated.

Aged↗
PubMed1989

Intracerebroventricular bethanechol chloride infusion in Alzheimer's disease. Results of a collaborative double-blind study.

The use of intracerebroventricular bethanechol chloride infusion in patients with Alzheimer's disease was first reported in 1984. An initial trial in four patients demonstrated the feasibility of this approach for cholinergic drug delivery to the brain, but objective improvement in cognitive function was not documented. A collaborative placebo-controlled double-blind crossover study has now been carried out in 49 patients with biopsy-documented Alzheimer's disease. The results demonstrate a statistical improvement in Mini-Mental State scores and significantly slower performance on Trails A testing during drug infusion. Other neuropsychological test scores were not similarly affected. The degree of improvement was not sufficient to justify further treatment of Alzheimer's disease patients by intracerebroventricular infusion of bethanechol chloride. The drug delivery system used in the study was well tolerated, with two irreversible complications in more than 50,000 patient days.

Alzheimer Disease↗
PubMed1988

Platelet tritiated imipramine binding and MAO activity in Alzheimer's disease patients with agitation and delusions.

Decreased platelet 3H-imipramine binding density and decreased monoamine oxidase (MAO) activity have been considered as biological characteristics of several neuropsychiatric disorders, and may be related to central serotonin defects. Since serotonin system defects occur in Alzheimer's disease (AD), and decreased brain 3H-imipramine binding density, and increased brain and platelet MAO activity are reported also, we studied platelet 3H-imipramine binding density (Bmax) and platelet MAO activity in AD outpatients without antecedent psychiatric disorder. AD subjects with significant symptomatic behavioral disorder, predominantly agitation and delusions, and AD subjects without symptomatic behaviors were compared with controls. Age, sex, mini-mental state examination score, and illness duration did not distinguish the two AD groups. The agitated/delusional group showed significantly lower Bmax values than uncomplicated AD subjects or controls. MAO activity was significantly increased among female AD subjects without symptomatic behaviors compared to those who were agitated or to controls. These results indicate that 3H-imipramine binding and MAO activity may distinguish AD subjects with agitation or delusions from those without symptomatic behaviors, and suggest the existence of a biologically based Alzheimer's behavioral subtype.

Aged↗
PubMed1987

The significance of clinically defined subgroups of Alzheimer's disease.

The significance of clinically defined subgroups of Alzheimer's disease (AD) is discussed within a framework of etiologic, pathogenetic, and treatment issues. Cerebral amyloid angiopathy and familial AD are proposed as etiologic subtypes. Clinical heterogeneity associated with age at onset and sex are thought to reflect the presence of secondary pathogenetic factors. Longitudinal studies are necessary to clarify the meaning of various symptomatic patterns.

Age Factors↗
PubMed1987

The Modified Mini-Mental State (3MS) examination.

The Mini-Mental State (MMS) examination is a widely used screening test for dementia. The Modified Mini-Mental State (3MS) incorporates four added test items, more graded scoring, and some other minor changes. These modifications are designed to sample a broader variety of cognitive functions, cover a wider range of difficulty levels, and enhance the reliability and the validity of the scores. The 3MS retains the brevity, ease of administration, and objective scoring of the MMS but broadens the range of scores from 0-30 to 0-100. Greater sensitivities of the 3MS over the MMS are demonstrated with the pentagon item drawn by 249 patients. A summary form for administration and scoring that can generate both the MMS and the 3MS scores is provided so that the examiner can maintain continuity with existing data and can obtain a more informative assessment.

Alzheimer Disease↗
PubMed1986

Pathologic correlates of dementia in Parkinson's disease.

Histopathologic studies of the cerebral cortex, hippocampus, and three subcortical nuclei were performed in four patients with Parkinson's disease whose mental status had been evaluated by neuropsychologic testing. Clinicopathologic correlations suggest that dementia with marked visuospatial disturbance as well as severe aphasia may be associated with severe neuronal loss in subcortical nuclei, without significant numbers of plaques or tangles in the hippocampus and cerebral cortex. Furthermore, memory loss may not be consistently related to neuronal loss in the nucleus basalis of Meynert, particularly in non-Lewy body parkinsonism.

Aged↗
PubMed1985

Plasticity of hippocampal circuitry in Alzheimer's disease.

Two markers of neuronal plasticity were used to compare the response of the human central nervous system to neuronal loss resulting from Alzheimer's disease with the response of rats to a similar neuronal loss induced by lesions. In rats that had received lesions of the entorhinal cortex, axon sprouting of commissural and associational fibers into the denervated molecular layer of the dentate gyrus was paralleled by a spread in the distribution of tritiated kainic acid-binding sites. A similar expansion of kainic acid receptor distribution was observed in hippocampal samples obtained postmortem from patients with Alzheimer's disease. An enhancement of acetylcholinesterase activity in the dentate gyrus molecular layer, indicative of septal afferent sprouting, was also observed in those patients with a minimal loss of cholinergic neurons. These results are evidence that the central nervous system is capable of a plastic response in Alzheimer's disease. Adaptive growth responses occur along with the degenerative events.

Acetylcholinesterase↗
PubMed1985

Clinical subtypes of dementia of the Alzheimer type.

Clinical subtypes of dementia of the Alzheimer type were evaluated by comparing age at onset, aphasia, family history, and motor disorder in 146 individuals with progressive dementia. Early onset was significantly associated with more prevalent and more severe language disorder. Forty-five percent of all probands had familial history of dementia, but we could not differentiate relative familial risk based on age at onset or aphasia. Independent of duration of illness, myoclonus and noniatrogenic extrapyramidal disorder were associated with greater severity of dementia.

Aged↗
PubMed1984

Stability of neuronal number in the human nucleus basalis of Meynert with age.

Numbers of neurons in the nucleus basalis of Meynert were estimated in seventeen non-demented patients who died of chronic hepatic or cardiopulmonary disease. Neurons were counted at the site of maximal neuronal density (SMND). This site was chosen by reviewing serial sections around the decussation of the anterior commissure and appeared to be comparable in different individuals. No correlation between numbers of neurons and age could be found. It appears that no uniform neuronal loss occurs in the nucleus basalis with age. Taken together with biochemical studies of cerebral cortical choline acetyltransferase activity, these findings suggest that there is no overall change in cholinergic input to cerebral cortex with age.

Adult↗
PubMed1984

CT criteria of hemisphere asymmetry fail to predict language laterality.

We compared CT measures of the left and right cerebral hemispheres for two groups of right-handed aphasic adults: those who were left-hemisphere language dominant (n = 89) and those who were right-hemisphere language dominant (n = 15). The distribution of linear CT measures of anterior and posterior widths and lengths did not differ significantly in the two groups. These findings fail to support the hypothesis that CT criteria of hemisphere asymmetry predict language laterality.

Adult↗
PubMed1980

Computerized tomographic scan findings in patients with autistic behavior.

An analysis of the computerized tomography scans of 17 patients with autistic behavior was carried out by investigators independent from those selecting the subjects. Mild abnormalities of the ventricular system were noted in several scans (increased size, altered left/right relation of lateral ventricles), and in three scans major hydrocephalus and circumscribed lesions of the parenchyma were seen. It was not possible to discern a singular abnormal pattern, the abnormalities appearing consequent to a variety of disease processes of the CNS.

Adolescent↗
PubMed1980

Brachial plexus involvement in familial pressure-sensitive neuropathy: electrophysiological and morphological findings.

Two family members with hereditary pressure-sensitive neuropathy are reported. One patient presented atypically with acute brachial plexus neuropathy following transaxillary removal of the first rib. Electrophysiological studies showed slowing of motor nerve conduction in clinically affected and unaffected nerves. In vitro recording of the compound action potential of the subclinically involved sural nerve showed pronounced slowing in conduction of large and small myelinated fiber groups. These alterations correlated with morphological studies of the sural nerve that showed tomacula with acute and healed segmental demyelination. An inherited, generalized neuropathy manifested by a morphological abnormality of myelination may render peripheral nerves unduly susceptible to mechanical trauma, including positional pressure or traction effects during general anesthesia.

Adult↗
PubMed1980

Progressive dialysis encephalopathy ("dialysis dementia").

Sixty cases of distinctive progressive and fatal encephalopathy have been reported in patients undergoing long-term hemodialysis. An analysis of their records reveals that mean duration of hemodialysis prior to onset is 2.5 years, while mean duration of clinical course until death is 6.3 months. The most frequent clinical manifestations include disturbances in communication (87%), cognition (66%) and movement (93%). Nonspecific electroencephalographic abnormalities are present in all cases. The condition is possibly related to some yet unidentified metabolic disorder. There is no effective therapy.

Adult↗