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Biomedical subjects

K Kamimura

Publications and source records attributed to K Kamimura.

118 records · Page 7Linked to original sources

Sorsby's fundus dystrophy in two Japanese families with unusual clinical features.

PURPOSE: To describe two Japanese families with Sorsby's fundus dystrophy (SFD) with unusual clinical features. METHODS: Two families from Kagoshima Prefecture with senile-onset macular dystrophy were examined. Three affected individuals through three successive generations of one family and three affected siblings in another family were examined and followed. RESULTS: The initial symptom of these patients was a rapid or slow central visual loss that occurred at an average age of 67.4 years. The major ophthalmoscopic changes consisted of soft drusen and hemorrhagic or atrophic lesions in the macula, which were progressive and ultimately led to disciform scarring. They had no difficulty with night vision. All the patients had normal peripheral retina with intact peripheral fields. They maintained good ambulatory vision and could walk unguided until late in life. These patients had a novel mutation in the tissue inhibitor of the metalloproteinases-3 (TIMP3) gene. CONCLUSIONS: This is the first report of SFD from the East. Its clinical features differ from those of SFD patients of the West, appearing closer to features of age-related macular degeneration. These two unrelated Japanese families with an identical mutation in the TIMP3 gene might be descendants of a common ancestor who carried the mutant gene.

Aged↗

Genetic risk factors in Japanese Alzheimer's disease patients: alpha1-ACT, VLDLR, and ApoE.

We studied the polymorphism of alpha1-antichymotrypsin (ACT), very low density lipoprotein receptor (VLDLR) and apolipoprotein E (ApoE) genes in 200 control subjects and 65 patients with Alzheimer's disease (AD) in Japanese. The subjects consisted of 30 patients with early onset familial Alzheimer's disease (FAD), a patient with late onset FAD, 29 patients with an early onset isolated form of AD, and 5 patients with late onset AD. ApoE genotypes were significantly different between controls and FAD (p < 0.0005) or AD (p < 0.05), and patients carrying at least one ApoE epsilon4 allele were found in 44% of FAD and 34.3% of AD; both were significantly different (p < 0.001) from the controls (12.5%). ACT genotypes and allele frequencies were not different among these groups except for genotypes between ApoE epsilon4 FAD and ApoE epsilon4 controls (p = 0.019). There was a slight but significant increase of the 5 repeat allele of VLDLR in AD (p = 0.014), but the difference was rather diminished in the presence of an ApoE epsilon4 allele. None of combinations of ACT and VLDLR genotypes in the presence or absence of an ApoE epsilon4 allele gave significant difference. Thus, we conclude that among the reported genetic risk factors, ApoE epsilon4 is the only definite risk factor for both FAD and AD, and the VLDLR polymorphism might be associated with AD cases in Japanese.

Alleles↗

Identification of a Notch3 mutation in a Japanese CADASIL family. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary disease that is characterized by recurrent stroke episodes and focal neurologic deficits progressing to pseudobulbar palsy and dementia. The causative gene is the Notch3 gene on chromosome 19, and 22 missense mutations have been identified in Caucasian patients to date. To perform mutational analysis of the Notch3 gene, we identified its exon intron boundaries and prepared sets of primers for amplification of each exon. Using these primers, we determined the Notch3 gene in a Japanese family with CADASIL symptoms and found a missense mutation (Arg133Cys) in exon 4. The mutation was heterozygous and cosegregated with the disease. Thus, the Notch3 gene is responsible for CADASIL in patients across different ethnic groups.

Dementia, Multi-Infarct↗

Development of Plasmodium berghei ookinetes to young oocysts in vitro.

The mosquito stage of Plasmodium berghei was cultivated in vitro, with special attention to ookinete transformation into early oocyst. The ookinetes were obtained by in vitro culture of gametocytes taken from infected mice, purified by density gradient of metrizoic acid or a lymphocyte separation medium, and incubated either in acellular culture or in co-cultivations with mosquito cells. In acellular culture, the ookinetes were found to aggregate with each other and transformed from banana to round shapes. Their inner pellicular membranes and subpellicular microtubules partially disappeared, indicating that development to early oocyst had occurred. Co-cultivation wtih Aedes albopictus cells (C6/36 clone) revealed that ookinetes transformed into early oocyst in the medium, or invaded the cells and then transformed to early oocysts within the cell cytoplasm as well. However all of these transformed cells failed to develop further, i.e., neither deposition of the oocyst capsule nor nuclear division was observed. Many ookinetes which failed to penetrate the Aedes cells were phagocytized within three days of culture. A significant difference between invaded and transformed oocysts and phagocytized ookinetes was seen in that the former lacked vacuole membrane. Co-cultivation with Toxorhynchites amboinensis cells (TRA-284-SFG clone) permitted transformation of ookinetes into early oocysts in the medium as in the acellular culture, but no ookinete invasion nor phagocytosis by the cell was observed.

Aedes↗

Mutations of the notch3 gene in non-caucasian patients with suspected CADASIL syndrome.

The Notch3 gene has been recently identified as a causative gene for cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). To investigate the genetic contribution of Notch mutations in familial cases with vascular leukoencephalopathy, we screened 13 patients from 11 unrelated families, which were selected on the basis of magnetic resonance imaging findings and positive family history. We identified three different missense mutations in 5 patients from 4 families. Two (Arg90Cys and Arg133Cys) are the same as previously reported in Caucasian patients, the other (Cys174Phe) is a novel mutation causing a loss of a cysteine in epidermal-growth-factor-like repeats of Notch3. These data indicate that the CADASIL Notch3 mutations were found in approximately 35% of familial cases with leukoencephalopathy, suggesting genetic heterogeneity of the disease.

Adult↗