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Biomedical subjects

K Urakami

Publications and source records attributed to K Urakami.

At least 73 records · Page 4Linked to original sources

Plasma and serum G4 isoenzyme of acetylcholinesterase in patients with Alzheimer-type dementia and vascular dementia.

We developed a new assay for plasma or serum G4 acetylcholinesterase (AChE) activity. There was no difference in G4 AChE activity between serum and plasma. Plasma AChE activity in control subjects (8-92 years) was independent of age. Serum G4 AChE activity was significantly increased in patients with vascular dementia (P less than 0.01), compared with age-matched control, and significantly decreased in those with probable Alzheimer-type dementia (P less than 0.02). The difference between VD and ATD was significant (P less than 0.001), and thus the measurement of plasma or serum G4 AChE activity would be helpful in the differential diagnosis of dementia.

Acetylcholinesterase↗

In vitro and in vivo antagonists against parathyroid hormone-related protein.

Four analogues of parathyroid hormone-related protein (PTHrP), PTHrP(7-34)NH2, (10-34)NH2, (15-34)NH2 and (20-34)NH2, were synthesized and their antagonistic activity against PTHrP(1-34) was examined in vitro and in vivo. In vitro studies revealed that all four analogues antagonized PTHrP-stimulated cyclic AMP production in rat osteosarcoma cells (ROS 17/2.8), and that PTHrP(7-34)NH2 and PTHrP(10-34)NH2 had potent antagonistic activity. In vivo experiments in nude mice also revealed that PTHrP(7-34)NH2 completely inhibited hypercalcemia induced by PTHrP(1-34), indicating that these analogues antagonize the effects of PTHrP(1-34) in vitro and in vivo.

Adenylyl Cyclases↗

A community-based study of parental age at the birth of patients with dementia of the Alzheimer type.

The association of dementia of the Alzheimer type (DAT) with parental age at the birth of patients who develop DAT was investigated in a community-based study in Japan. Both maternal and paternal ages of patients who have developed DAT are significantly higher than those in controls and multi-infarct dementia. This study suggests that advanced age may become a cause of chromosome abnormality, and advanced parental age at subjects' birth may be a possible risk factor in DAT.

Adult↗

Muscle contraction headache and migraine. Platelet activation and plasma norepinephrine during the cold pressor test.

For clarification of possible platelet activation in migraine and chronic muscle contraction headache (MCH) under stress, plasma platelet factor 4 (PF4), norepinephrine (NE), and free fatty acids (FFA) were investigated during the cold pressor test. Both PF4 and NE increased significantly, whereas FFA showed no remarkable changes. The increases of PF4 in MCH and migraine during this test were significantly greater than in healthy controls. The increase of PF4, however, was independent of NE increase and FFA changes. On the other hand, we observed decreased NE levels in both MCH and migraine, which might suggest peripheral sympathetic hypofunction. The platelets of MCH or migraine patients seem to be impaired, and the impairment may be caused by continuous sympathetic hypofunction. The behaviour of the above three substances in MCH was similar to that in migraine throughout the present study.

Blood Platelets↗

Apolipoprotein abnormalities in dementia.

The serum levels of apolipoprotein B, C-II and the ratio of apolipoprotein B/A-I were found to be significantly higher in multiinfarct dementia than in dementia of the Alzheimer type. The high serum levels of apolipoprotein B, C-II and the high ratio of apolipoprotein B/A-I may cause multiinfarct dementia. The large difference between the groups suggests that the serum levels of apolipoprotein B, C-II and the ratio of apolipoprotein B/A-I may be useful in differential diagnosis of these two kinds of dementia.

Aged↗

Cerebral infarction due to disseminated intravascular coagulation with thromboexclusion for dissecting aortic aneurysma.

Cerebral infarction due to chronic disseminated intravascular coagulation (DIC) after thromboexclusion for thoracic dissecting aortic aneurysma is described. Chronic DIC may be caused by the delay of thrombus formation at the site of thromboexclusion, and local DIC occurred at that site. It is difficult to find chronic DIC. This case shows that DIC after thromboexclusion for dissecting aortic aneurysma may be one of the causes of recurrent cerebral infarction.

Aortic Dissection↗

Characterization of the course of senile dementia of the Alzheimer type using cerebrospinal fluid levels of acetylcholinesterase and somatostatin.

Through an epidemiological survey, we observed 3 types of clinical courses among patients with senile dementia of the Alzheimer type (SDAT). The mental ability of the patients declined rapidly (Group A; n = 11), gradually (Group B; n = 6), or showed extremely slow changes (Group C; n = 9). The acetylcholinesterase (AChE) activity and somatostatin (SRIF) concentration of the cerebrospinal fluid (CSF) were measured in patients with Alzheimer's disease (AD) and 3 types of SDAT. Both AChE activity and SRIF concentration of CSF were significantly lower in Group A and among patients with AD compared with age-matched control subjects. Both AChE activity and SRIF concentration of CSF were not significantly different in Groups B and C. This biochemical study confirmed our epidemiological finding that only the patients in Group A with SDAT closely resembled the clinical course of AD and may belong to the category of neurodegenerative disorders.

Acetylcholinesterase↗

Increase of striatal dopamine turnover by stress in MPTP-treated mice.

The characteristics of motor function and brain dopamine (DA) metabolism in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice after immersion immobilization stress were investigated. There was no significant difference in locomotor activities between MPTP-treated and saline-treated mice, but locomotor activities of MPTP-treated mice after stress decreased more remarkably than those of saline-treated mice. Immediately after stress, striatal DA concentrations of MPTP-treated mice were significantly lower than those of saline-treated mice. Striatal DA levels improved when 24 h passed after stress. The striatal and cortical (DOPAC + HVA)/DA ratios of MPTP-and stress-treated mice was significantly higher than that of saline-and stress-treated mice. It is due to the decreased DA level and the enhancement of DA turnover that MPTP-treated mice became remarkably akinetic after stress, and that L-DOPA therapy is not effective when the symptoms in patients with Parkinson's disease worsen due to stress.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

Lp(a) lipoprotein in cerebrovascular disease and dementia.

Lp(a) lipoprotein has been considered an independent risk factor in the development of coronary heart disease (CHD). We examined the role of Lp(a) in patients with cerebrovascular disease (CVD) and those with dementia. The Lp(a) concentration in patients with CHD, those with cerebral infarction due to a large artery occlusion and those with vascular dementia (VD) was significantly higher than that of age-matched control subjects. However, the Lp(a) concentration was not high in cerebral infarction due to a small artery occlusion, intracerebral hemorrhage and dementia of the Alzheimer type (DAT). The present results suggest that Lp(a) should cause VD as well as CVD, and that Lp(a) should be one of the indicators that distinguish VD from DAT.

Aged↗

No association between DLST gene and Alzheimer's disease or Wernicke-Korsakoff syndrome.

Among many candidate genes for the genetically heterogeneous Alzheimer's disease (AD), only apolipoprotein E (ApoE) has been confirmed. Another candidate is the dihydrolipoyl succinyltransferase (DLST) gene, one of three components of thiamine-dependent mitochondrial alpha-ketoglutarate dehydrogenase complex (KGDHC), because KGDHC activity is reported reduced in AD patients. Also characterized by reduced KGDHC activity is another neuropsychiatric disease, Wernicke-Korsakoff syndrome (WKS), which results from thiamine deficiency. Examination of specific DLST gene polymorphism in 247 Japanese AD patients, 53 alcoholic WKS patients, and 368 nondemented Japanese control subjects revealed no significant differences in DLST genotypes and failed to replicate the findings of earlier studies indicating an association between DLST gene polymorphism and AD.

Acyltransferases↗

Apolipoprotein E in patients with dementia of the Alzheimer type and vascular dementia.

The phenotypes of apolipoprotein E (ApoE) in the plasma of patients with dementia of the Alzheimer type (DAT) and vascular dementia (VD) were determined by the isoelectric focusing method. The ApoE mRNA level in the skin fibroblasts was also determined by the Northern blot analysis. As compared with the control subjects, the frequency of the ApoE epsilon 4 allele was significantly higher in the DAT group as well as the VD group, but was not significantly different in the cerebrovascular disease without dementia (CVD) group. The skin fibroblast ApoE mRNA level in the DAT group and the VD group was significantly lower than that in the control group. These findings suggest that the phenotype of ApoE is associated with DAT and VD, and that the lower level of ApoE mRNA may play an important role in the development of DAT as well as VD.

Aged↗

The expression of presenilin-1 mRNA in skin fibroblasts from Alzheimer's disease.

The presenilin-1 (PS-1) gene was recently identified as one of the causative genes in the early onset of familial Alzheimer's disease (AD). Analysis of the PS-1 gene is thought to be useful in clarifying the pathogenesis of AD. However, there have been few reports about the expression of the PS-1 gene in AD. In this study, we analyzed the expression of PS-1 mRNA in cultured skin fibroblasts taken from living patients with AD by Northern blot analysis. The subjects consisted of 18 cases with AD and 10 cases of neurological patients without dementia (CTL). We found that the PS-1 mRNA levels in AD were significantly higher than those in CTL (p < 0.01). Moreover, we found that the PS-1 mRNA level increases in the early stages of AD and tends to decrease in the advanced stages. These findings suggest that high levels of PS-1 mRNA may play an important role in developing AD.

Adult↗