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Biomedical subjects

A Kuwano

Publications and source records attributed to A Kuwano.

At least 37 records · Page 2Linked to original sources

Benign adult familial myoclonus epilepsy (BAFME): an autosomal dominant form not linked to the dentatorubral pallidoluysian atrophy (DRPLA) gene.

The genetic differences between two types of dominant inherited myoclonus epilepsy, dentatorubral pallidoluysian atrophy (DRPLA) and benign adult familial myoclonus epilepsy (BAFME), have been reported. A gene with a CAG repeat expansion responsible for DRPLA has been isolated. We have examined CAG repeat expansion in the DRPLA gene in five BAFME families, and the abnormal CAG expansion was not observed in the affected subjects. Linkage analysis using DNA polymorphisms in the DRPLA gene and the genes for gamma-aminobutyric acid (GABA) receptor subunits, GABAR beta 1, GABAR beta 3, and GABAR alpha 6, showed that these genes were not responsible for BAFME.

Atrophy↗

Pathomorphological findings in a case of onychomycosis of a racehorse.

The hooves of a racehorse which were affected with white line disease and hoof wall disorders on both forelimbs were histopathologically investigated using thin ground section and standard paraffin section techniques. On both hooves, large quantities of fungus were found to have invaded the white line tissues, especially in the terminal horn which were markedly damaged. The fungus was also present among the cellular debris in the fissures of horny tissues. The morphological characteristics of the fungus were brown (its natural color), PAS-positive, mold-like shape with septa inside the tissues, and unicellular spores outside the tissues. These findings suggest that onychomycosis was a primary and/or secondary cause of white line disease in this subject.

Animals↗

Isolation, characterization, and chromosomal mapping of the human insulin promoter factor 1 (IPF-1) gene.

Insulin promoter factor 1 (IPF-1) is a homeodomain-containing protein that is thought to be a key regulator of pancreatic islet development and insulin gene transcription in beta-cells. This report describes the isolation and characterization of the human IPF-1 gene. The coding region, which showed 83% nucleotide identity with the mouse IPF-1 gene, was encoded by two exons that extended over a 5-kb region of human genome. The deduced human IPF-1 protein contained 283 amino acids, 1 amino acid less than the mouse IPF-1 protein. The homeodomain region of IPF-1 was encoded by the second exon, and it was highly conserved among species. The human IPF-1 gene was mapped to chromosome 13q12(12.1) by fluorescent in situ hybridization (FISH) analysis. A simple sequence repeat polymorphism (ipf1CA2) was identified in the genomic clone. Polymerase chain reaction (PCR) amplification of this repeat region revealed two alleles (heterozygosity = 0.32). This simple sequence repeat polymorphism, and thus the IPF-1 gene, was incorporated into the human linkage map by genotyping reference Human Polymorphism Study Center (CEPH) pedigrees. Multipoint analysis with the CEPH genotype database placed the gene with equal likelihood between two marker intervals: D13S292-cdx3GA1 and cdx3GA1-D13S289 on chromosome 13, consistent with the results of FISH analysis. Two-point linkage analysis inferred that the most likely location for ipf1CA2 was at theta = 0 from cdx3GA1 locus. The exon-intron boundaries of the IPF-1 gene were sequenced, and primers were synthesized to search the homeodomain region for potential variants in patients with NIDDM. By single-strand conformational polymorphism analysis, no variants were found within this region in 61 Japanese patients, which could contribute to the pathogenesis of NIDDM. The isolation of the human IPF-1 gene, along with characterization of its genomic structure and chromosomal mapping, will now permit the assessment of the role of this gene in the pathogenesis of NIDDM in various populations.

Amino Acid Sequence↗

Association analysis of a polymorphism of the monoamine oxidase B gene with Parkinson's disease in a Japanese population.

The polymorphic allele of the monoamine oxidase B (MAO-B) gene detected by polymerase chain reaction (PCR) and single-stranded conformation polymorphism (SSCP) was associated with Parkinson's disease (PD) in Caucasians. We characterized this polymorphic allele, allele 1, of the MAO-B gene using direct sequencing of PCR products. A single DNA substitution (G-A), resulting gain of Mae III restriction site was detected in intron 13 of the MAO-B gene. The allele associated with PD in Caucasians was twice as frequent as in healthy Japanese, but the association of the allele of the MAO-B gene was not observed in Japanese patients with PD.

Adult↗

Molecular cloning and gene mapping of human basic and acidic calponins.

The nucleotide and deduced amino acid sequences of human basic and acidic calponins were determined. The basic calponin cDNA from human aorta (1496 bp) contained a single open reading frame (ORF) which encodes 297 amino acids (33,169 Da). The acidic calponin cDNA from human kidney (1607 bp) contained a single ORF which encodes 329 amino acids (36,412 Da). Basic calponin mRNA was expressed in only smooth muscle tissues, but acidic calponin mRNA was expressed in non-smooth muscle tissues as well as smooth muscle tissues. Fluorescent in situ hybridization revealed that basic and acidic calponin genes localize in 19p13.1-13.2 and 1p21-22 of human chromosomes, respectively.

Amino Acid Sequence↗

Dentatorubral-pallidoluysian atrophy (DRPLA): clinical, genetic, and neuroradiologic studies in a family.

The clinical, genetic, and neuroradiologic characteristics of dentatorubral-pallidoluysian atrophy (DRPLA) are delineated in six patients from three generations of a Japanese family. The clinical characteristics of the disease varied, the age at onset depending on patients with juvenile-onset were characterized by myoclonus, epilepsy, and mental retardation whereas cerebellar ataxia, choreoathetosis, and dementia were typical of adult- and senile-onset patients. All affected individuals showed one expanded allele with the repeat number of CAG at the DRPLA locus, ranging from 58 to 82, and a normal allele, ranging from 10 to 21. The most severely affected patient, a case of maternal transmission and with the largest allele, became bedridden in a vegetative state by age 12. On the CT and MRI, varying degrees of brain atrophy were present in all patients. T2-weighted MRI in patients with senile-onset showed symmetric high-signal lesions in the cerebral white matter, globus pallidus, thalamus, midbrain, and pons. However, MRI in younger patients revealed no such lesions and CT failed to demonstrate lesions in the globus pallidus and brain stem. Thus, intrafamilial heterogeneity of DRPLA was also evident on MRI. High-signal lesions involving both, subcortical white matter and thalamus may be characteristics of senile-onset patients and may correlate with their dementia.

Adult↗

Age-related morphometrical changes of arteries of uterine wall in mares.

To investigate the morphological changes of uterine wall arteries associated with the progression of age in Thoroughbred broodmares, uterine wall arteries from 13 mares, aged 2 to 31 years, were studied by routine histomorphometry. The ratio of intimal thickness to external diameter increased due to hyperplasia of elastic fibers and was significantly correlated with age (r = 0.95, P < 0.001). The ratio of medial thickness to external diameter decreased and was also significantly correlated with age (r = -0.84, P < 0.001). Using electron microscopy, it was determined that the cross-sectional area of the tunica media occupied by smooth muscle cells gradually decreased with increasing age. These results demonstrate that in arteries of the uterine wall in mares, hyperplasia of intimal elastic fiber and thinning of the medial smooth muscular layer is associated with aging, suggesting that aging may influence endometrial pathology.

Aging↗

Isochromosome 15q of maternal origin in two Prader-Willi syndrome patients previously diagnosed erroneously as cytogenetic deletions.

Since our previous report on two Prader-Willi syndrome (PWS) patients with t(15q;15q) (Niikawa and Ishikiriyama; Hum Genet 69:22-27, 1985) was erroneous, we report here new data and a corrected interpretation. Reexamination of the parental origin of their t(15q;15q) using polymorphic DNA markers that are mapped to various regions of 15q documented no molecular deletions at the 15q11-q13 region in either patient. Both patients were homozygous at all loci examined and their haplotypes on 15q coincided with one of those in their respective mothers. These results indicate that the presumed t(15q;15q) in each patient was actually an isochromosome 15q producing maternal uniparental disomy, consistent with genomic imprinting at the PWS locus.

Aneuploidy↗

Mapping of the human gene for inducible heme oxygenase to chromosome 22q12.

Heme oxygenase is an essential enzyme in heme catabolism that cleaves heme to form biliverdin, releasing carbon monoxide and iron. There are two isozymes of heme oxygenase: heme oxygenase 1 (HO-1) and heme oxygenase 2, each of which is encoded by a separate gene. It is noteworthy that HO-1 is inducible by various environmental factors, while heme oxygenase 2 is not. Here we have localized the human HO-1 gene to chromosome 22 by polymerase chain reaction (PCR) analysis of human-hamster somatic cell hybrids. The precise region of the HO-1 locus was then determined by fluorescence in situ hybridization, revealing that the human HO-1 gene is localized to 22q12.

Animals↗

Computed tomography in fetal methylmercury poisoning.

Cerebral computed tomography was studied in eight patients with fetal methylmercury poisoning. All patients had evidence of prenatal exposure to methylmercury and showed psychomotor retardation. All of them had abnormal computed tomography findings. The most common finding was sulcal and ventricular enlargement, with or without cisternal enlargement. These findings indicated generalized cortical and subcortical maldevelopment. The distribution of sulcal and fissural enlargement did not show specific dominance in central sulcus, calcarine fissure or cerebellum. This distribution contrasts with the location of focal atrophy present in adult methylmercury poisoning. The computed tomography findings were relatively mild compared with the clinical features and were not distinct from those in cerebral palsy.

Activities of Daily Living↗

Telomere association of human chromosomes induced by aphidicolin.

Telomere associations were studied in metaphase chromosomes from 96-h cultures of peripheral blood lymphocytes of two healthy women, treated with 0.4 microM aphidicolin for the last 72 h. Telomere associations were encountered in 2.9% and 3.2% of the metaphases screened, whereas no such associations were encountered in 5-fluorodeoxyuridine-treated cultures. The chromosome arms involved in telomere associations were nonrandom: 1q, 2q, 3q, 6p and 16q were more frequently involved in the associations (P less than 0.01). Of the 51 combinations of telomere associations encountered, those occurring nonrandomly were 1q/2q, 2q/2q, 4q/4q, 6q/6q and 6p/6p associations.

Adult↗

Gene dosage is a mechanism for Charcot-Marie-Tooth disease type 1A.

Charcot-Marie-Tooth disease type 1A (CMT1A) is the most common inherited peripheral neuropathy in humans, characterized electrophysiologically by decreased nerve conduction velocities (NCVs). CMT1A is associated with a large submicroscopic DNA duplication in proximal 17p. In this report we demonstrate that a patient with a cytogenetically visible duplication, dup(17)(p11.2p12), has decreased NCV. Molecular analysis demonstrated this patient was duplicated for all the DNA markers duplicated in CMT1A as well as markers both proximal and distal to the CMT1A duplication. These data support the hypothesis that the CMT1A phenotype can result from a gene dosage effect.

Charcot-Marie-Tooth Disease↗