Michihiro Kimura

Endothelin-1-like immunoreactivity in cerebral cortex of Alzheimer-type dementia

1. Endothelin-1-like immunoreactivity (ET-1-LI) in cerebral cortex in postmortem brains obtained from patients with Alzheimer-type dementia (ATD) was measured by enzyme-immunoassay. 2. The ET-1-LI in the ATD brains was significantly increased in frontal and occipital cortex than those in the control brains and a significant correlation was found between frontal and temporal lobe of ATD brains. 3. These findings may explain the clinico-radiological results that the cerebral blood flow is decreased in ATD patients, the mechanism of which is still unknown.

Irreversible Subcortical Dementia Following High Altitude Illness

In this report, we present the cases of two 63-year-old women who developed high altitude cerebral edema complicated by the occurrence of permanent neuropsychiatric sequelae. They shared a similar clinical course, in that both developed disturbance of consciousness shortly after their arrival at Cuzco, Peru (3500 m), and both developed persistent neuropsychiatric symptoms after resolution of the acute illness. Interestingly, in case 2 there was a 1-month lucid interval between remission of high altitude illness and occurrence of the irreversible neuropsychiatric sequelae. Brain computerized tomography in case 1 and brain magnetic resonance imaging in case 2 disclosed lesions in the globus pallidus bilaterally, suggesting that the neuropsychiatric symptoms in these patients were manifestations of subcortical dementia. The development of high altitude illness was considered to be attributable to mild restrictive lung impairment in case 1 and to a deficient ventilatory response to hypoxia in case 2. It must therefore be borne in mind that irreversible subcortical dementia may be associated with high altitude cerebral edema.

Assessment of cerebrospinal fluid levels of serum amyloid P component in patients with Alzheimer's disease

Serum amyloid P component (SAP) is a normal plasma constituent that is observed both in senile plaque and in neurofibrillary tangle in brains of patients with Alzheimers disease (AD). In this study, we evaluated the SAP levels in cerebrospinal fluid (CSF) of 72 patients with AD, 11 frontotemporal dementia and nine normal control subjects. There was no significant difference in the SAP levels between the AD group and other groups. However, among AD patients, cognitive function was rated using the Mini-Mental State Examination and was correlated with the SAP level (R = 0.38, P < 0.05). Our results suggest that measurement of the SAP levels in CSF can be useful for assessing the degree of cognitive impairment in AD patients.

Serum Amyloid P Component Level in Alzheimer's Disease

Serum amyloid P component (AP) is a normal plasma constituent that is observed in senile plaques and neurofibrillary tangles in brains of Alzheimers disease (AD) patients. In this study we have evaluated the AP levels in sera of 16 patients with AD and in 16 control subjects by enzyme-linked immunosorbent assay. The AP level was 22.4 +/- (SD) 7.0 micrograms/ml in the AD group and 34.4 +/- (SD) 6.6 micrograms/ml in the control group. The AP level in the AD group was significantly lower than that of the control group (p < 0.01). In the control group, there was no correlation between AP levels and age. Our results suggest that the production of AP by the liver (hepatocytes), thought to be the only source, may be suppressed in AD patients and that the deposition of AP in senile plaques and neurofibrillary tangles is not due to its overproduction.

Demographic and psychological features of déjà vu experiences in a nonclinical Japanese population.

The authors investigated the frequency and correlates of déjà vu experiences in 386 healthy adult volunteers recruited from several areas in Japan. Déjà vu experiences and related experiences were evaluated using the Inventory of Déjà vu Experiences Assessment. Déjà vu experiences were observed by 294 (76.2%) of the 386 participants. Persons who experienced déjà vu were younger and more educated than persons who had not experienced it. There were no differences in the frequency of déjà vu experiences based on sex, hand preference, or area of residence. Subsequent factor analysis associated déjà vu with precognitive dreams and remembering dreams as dream- and memory-related factors rather than with the dissociation-related factors of depersonalization, derealization, jamais vu, and daydreams or with mental activity-related factors such as paranormal quality and travel frequency. Results suggest that déjà vu experiences are associated with good memory function.

Utility of the Bender Gestalt Test for Differentiation of Dementia with Lewy Bodies from Alzheimer’s Disease in Patients Showing Mild to Moderate Dementia

Aims: We examined the utility of the Bender Gestalt Test (BGT) for the differentiation of dementia with Lewy bodies (DLB) from Alzheimer’s disease (AD), comparing BGT scores between DLB and AD patients showing mild to moderate dementia. Methods: Eighteen DLB patients, 36 AD patients controlled by age, years of education, Clinical Dementia Rating and Mini Mental State Examination scores, and 21 nondemented elderly participants controlled by age and years of education were subjected to the BGT. Their BGT performances were scored according to the Pascal-Suttell method. Results: The DLB group showed significantly higher (that is worse) BGT scores than the other groups. When a cutoff point of 98 was used to differentiate DLB from AD, the patients exceeding 98 were 94% in the DLB group, 17% in the AD group and 0% in the control group. The sensitivity and specificity of this cutoff point were 0.94 and 0.89, respectively. Conclusion: The BGT is a useful neuropsychological test to differentiate DLB from AD.

Amyloid-P-component-like immunoreactivity in β/A4-immunoreactive deposits in Alzheimer-type dementia brains

An immunohistochemical study using the mirror-image technique was performed in order to establish whether amyloid P component is involved in the mechanism of deposition of amyloid fibrils in senile plaques (SPs) in Alzheimer-type dementia (ATD). Ninety percent of β/A4 protein-immunoreactive SPs were also stained by the anti-amyloid P component immunchistochemistry, and this applied to all of the diffuse, primitive and classical types of β/A4 deposits. These findings may suggest an involvement of amyloid P component in the formation of amyloid fibrils in senile plaques in ATD brains.

Quantitative single photon emission tomography analysis for the diagnosis of transient global amnesia: Adaptation of statistical parametric mapping

Abstract We report two cases of transient global amnesia (TGA) diagnosed using a clinical criteria and single photon emission tomography (SPECT) with the aid of Statistical Parametric Mapping (SPM). Both patients underwent an initial SPECT study about 20 h after the disappearance of the amnesic episode, and a second study 3 weeks after the episode. We conducted quantitative cerebral blood flow (CBF) analyses using SPM on Matlab. This revealed regions with abnormal CBF in the first studies but not in the second. This method appears to be useful for diagnosis of TGA, especially in patients with suspected TGA in whom the amnesic episode disappears within a few days.

A preliminary study on plasma concentrations of bifemelane, indeloxazine and propentofylline in aged patients with organic brain disorders.

1. Plasma concentrations of cerebral metabolic activating drugs (bifemelane, indeloxazine and propentofylline) were studied in 68 patients (male 25, female 43) with dementia or other organic brain diseases. 2. The variations in plasma concentrations of these drugs were much bigger than expected. Measurements of bifemelane level with time course also disclosed that the concentrations were relatively stable for several months, but they varied very much among patients. 3. These findings suggest that drug monitoring are important in terms of evaluation of drug efficacy and prevention of side effects.

Amyloid P component immunoreactivity in brains of Alzheimer‐type dementia is reduced by formic acid pretreatment on tissue section

In order to elucidate the enhancement mechanism of amyloid staining by formic acid (FA) pretreatment on a tissue section, we investigated changes of immunoreactivity of amyloid P component (AP) in senile plaques of Alzheimer‐type dementia (ATD) brains. Although immunoreactivity of various amyloidogenic proteins is enhanced by FA treatment, the immunoreactivity of AP was reduced by the treatment in this study. Amyloid P is thought to deposit to amyloid structure by leakage from blood vessels. Therefore, this result suggests that the enhancement effect depends not only on the property of amyloidogenic protein itself but also on the binding form to amyloid structure.