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Biomedical subjects

Y Miyake

Publications and source records attributed to Y Miyake.

At least 307 records · Page 17Linked to original sources
PubMed1993

Low-density lipoprotein receptor mutation that deletes exons 2 and 3 by Alu-Alu recombination.

A deletion mutant in the low density lipoprotein receptor gene of a Japanese patient with heterozygous familial hypercholesterolemia was analyzed. Genomic Southern blotting showed abnormal size restriction fragments with BamHI (7.8 kb), EcoRI (3.8 kb), BglII (17 kb), KpnI (> 23 kb), EcoRV (13 kb), and XbaI (14 kb). The abnormal EcoRI fragment, 3.8 kb, was cloned into lambda phage vector, and the deleted region of 10 kb including exons 2 and 3 was identified. The nucleotide sequence around the deletion joint was determined. The sequence of the eight nucleotides in the deletion-joint region of the mutant gene was identical to the corresponding sequences of both introns 1 and 3 of the normal gene. The deletion seemed to occur by an unequal recombination between the Alu-like sequences in the same direction in introns 1 and 3.

Base Sequence↗
PubMed1993

Hamster alpha-macroglobulin and murinoglobulin: comparison of chemical and biological properties with homologs from other mammals.

alpha-Macroglobulin and murinoglobulin were purified to homogeneity from Syrian hamster plasma and their properties were compared with those of their respective homologs from other mammals. The trypsin-inhibiting capacity of hamster murinoglobulin was much weaker than those of rat and mouse murinoglobulins. Hamster alpha-macroglobulin was cleaved by trypsin at a number of sites whereas the human homolog was split essentially only in a "bait" region into two fragments of similar size. Hamster alpha-macroglobulin treated with methylamine differed from that treated with trypsin in the electrophoretic mobility, intensity of fluorescence induced by binding of bis(8-anilino-1-naphthalenesulfonate), and plasma clearance pattern, whereas virtually no difference was observed between the human homologs treated in the same manner. The reaction of hamster alpha-macroglobulin with methylamine, as measured by the generation of thiol groups and the decrease in trypsin-protein amidase activity, was much slower than that of the human homolog. Trypsin in a complex with hamster alpha-macroglobulin retained its fibrinolytic activity, but this was not the case for human or rabbit alpha-2-macroglobulin. These results suggest that, compared with the human homolog, hamster alpha-macroglobulin is more loosely packed in the native state, undergoes conformational change more slowly on treatment with methylamine, and less efficiently hinders the access of proteinaceous substrates to trapped proteinase. The serum concentration of hamster alpha-macroglobulin was 6.9 mg/ml, or about 3-fold higher than that of the human type, and showed little change during the acute-phase reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Amidohydrolases↗
PubMed1993

Electrophysiologic detection of choroidal detachment in eyes with rhegmatogenous retinal detachment.

The base values of electrooculograms (EOGs) of 39 patients with new, unilateral rhegmatogenous retinal detachment and clear media were studied. None of the patients had a history of ocular surgery. Ophthalmoscopic examinations revealed choroidal detachment in 11 eyes. The mean (+/- SD) amplitude, expressed as a percentage of the amplitude recorded for unaffected fellow eyes, was 116 +/- 31% in the 28 eyes without choroidal detachment, and 39 +/- 10% in the 11 eyes with choroidal detachment. This difference was statistically significant (P < 0.0001). There was no significant correlation in either group between baseline value and extent of retinal detachment or intraocular pressure. These results indicate that choroidal detachment associated with rhegmatogenous retinal detachment can be revealed electrophysiologically by the baseline value of an EOG.

Adolescent↗
PubMed1993

Object images of eating disorder patients.

The authors investigated images held by eating disorder patients toward selected stimulus words using the semantic differential method. The concept "object image" was introduced here to designate the images which any person has about the mother, the father, etc. A comparison was made between 22 eating disorder patients with concurrent borderline personality disorder, 20 patients without borderline pathology, and 48 controls. The eating disorder patients were found to have a "weaker" image of "motherliness" and "womanliness" compared to the control group. Another characteristic of eating disorder patients was their unfavorable image of children. The authors also studied the images held by fathers and mothers. In the families with borderline patients, the discrepancies between what we term "object images" held by fathers, mothers, and daughters were conspicuous. The importance of a tripartite (daughter-mother-father) relationship in the psychopathology of eating disorder is discussed.

Adolescent↗
PubMed1993

Relationship between clinical symptoms and EEG findings in borderline personality disorder.

Borderline personality disorder (BPD) was diagnosed in female patients (N = 41) between the ages of 18 and 30 using the Diagnostic Interview for Borderline Patients (DIB) and DSM-III. Comparing the EEG findings of BPD (N = 18) and non-BPD (N = 21) groups, there were no EEG findings characteristic of BPD. We also assessed the relationship between the EEG findings and DIB items. Positive spikes appeared in patients with high scores for Impulse Action Patterns, while wave and spike phantoms were observed in patients with high scores for Interpersonal Relations. Dividing the patients into BPD and non-BPD groups, a similar tendency to that observed from an analysis of all patients was observed in the non-BPD group, but no such tendency was observed in the BPD group. The results suggest that BPD patients include those in whom vulnerability of cerebral function plays an important role in the development of these two clinical symptoms as well as those in whom vulnerability of cerebral function plays almost no pathogenic role.

Adult↗
PubMed1993

Information propagation by spatio-temporal pattern change of Ca2+ concentration throughout Physarum polycephalum with repulsive stimulation.

The development of a spatio-temporal pattern of Ca2+ concentration (Ca2+ pattern) in the plasmodium of Physarum polycephalum during repulsive response was studied using fura-2. In the migrating cell, the gradient of the Ca2+ concentration (Ca2+ gradient) immediately showed a decrease in local concentration in the area (S-site) stimulated by 50 mM KCl. The concentration rose and then decreased in a site neighboring the S-site. This transient increase of Ca2+ concentration, the duration of which was approx. 10 minutes, was propagated to the site most distant from the S-site. There, the Ca2+ concentration gradually rose and remained at a high level. Twenty-five minutes after stimulation, a new Ca2+ gradient was established throughout the plasmodium. The migratory direction of the cell as a whole then changed. In this process, although the period of Ca2+ oscillation changed at the S-site, this change was only local to the site. During the information processing of the local repulsive stimulus, the transient Ca2+ increase propagated the local information about the stimulus to the non-stimulation sites (NS-sites), leading to the generation of a new pattern and the start of coordinated migration of the plasmodium.

Animals↗
PubMed1993

Individual differences of the contribution of chromatic channels to brightness.

Perceived brightness is considered to be a combined consequence of outputs of the luminance channel and the chromatic channels in the visual system. The differences of logarithmic spectral luminous efficiencies between heterochromatic brightness matching and flicker photometry that were obtained from 16 subjects were examined by using principal component analysis. The luminous-efficiency difference between the two methods is described by only two principal components. Individual characteristics of the contribution of chromatic channels to brightness can be specified by measuring luminous efficiencies at 470 and 660 nm.

Adult↗
PubMed1993

[Therapeutic efficacy of cefodizime in combination with aminoglycosides against systemic infections caused by Pseudomonas aeruginosa in immunocompromised tumour bearing mice].

In vivo synergistic effects of cefodizime (CDZM) were investigated in combination with aminoglycosides (AGs), sisomicin (SISO) or dibekacin (DKB) against Pseudomonas aeruginosa in immunocompromised tumour bearing mice. Fractional effective dose (FED) indices showed that either synergistic or additive effects were observed between CDZM and AGs. The synergistic intraperitoneal bactericidal effect of CDZM in combination with SISO or DKB was also observed in immunocompromised tumour bearing mice. The post antibiotic effect (PAE) of AGs was prolonged by the addition of CDZM. Moreover, the strong synergistic bactericidal effects of CDZM and AGs against P. aeruginosa were observed in the presence of immunocompromised tumour bearing murine polymorphonuclear leukocytes (PMN). These results suggest that the strong therapeutic efficacy of CDZM in combination with AGs was caused by synergistic bactericidal effect of CDZM and AGs in the presence of PMN.

Animals↗
PubMed1993

Focal macular electroretinogram in X-linked congenital retinoschisis.

PURPOSE: To study macular function of X-linked congenital retinoschisis (CRS) by focal macular electroretinogram (MERG). METHODS: MERGs were recorded with 5 degrees, 10 degrees, and 15 degrees spots in 20 patients with CRS. Seventeen patients showed foveal schisis with little or no change in foveal fluorescein angiography (Group 1), and three patients showed advanced macular changes with nonspecific macular degeneration (Group 2). RESULTS: In Group 1, a-wave amplitudes were within the normal range, but b-waves and oscillatory potentials (OPs) had mean amplitudes significantly below those for normal control subjects. The mean b- to a-wave ratios, significantly lower than in normal eyes, decreased significantly with decreasing spot size. The implicit times of a-waves, b-waves, and OPs were significantly delayed. In Group 2, MERGs were nearly nondectable. CONCLUSIONS: The macular pathology of CSR exists mainly in the middle and inner retinal layers, disturbing the fovea more than the perifovea, whereas degeneration of photoreceptors progresses in more advanced stage.

Adolescent↗
PubMed1993

[A study on the integration of fetal behavior and the development of association between parameters evaluated].

To evaluate the development of the fetal behavioral state with reference to the association of the fetal parameters we selected, we simultaneously monitored fetal heart rate (FHR), fetal movement (FM), fetal eye movement (FEM) and fetal breathing movement (FBM). These various parameters were monitored with 2 ultrasonographic real time scanners and a doppler device to monitor fetal movement. We assessed the convergence and integration of these four parameters to evaluate the association rate (AR). FHR with a variation in excess of 3 min. was interpreted as the active phase (A), and reduced variation in excess of 3 min. as the inactive phase (I). When FM and FEM were observed in the 1 min. window of A, we labeled this A3, and when FBM was present in more than 10% of the 1 min. window, we labeled it A4. A3/A = AR-A3% and A4/A = AR-A4% was calculated. A similar calculation was done for I, without FM and FEM in the 1 min. window of I (I3) and when FBM was present less than 10% of 1 min. (I4), allow derivation AR-I3% and AR-I4%. A discrete separation of synchrony in A and asynchrony in I can be seen to develop as the fetus matures, and we feel that this may be a valuable tool in the evaluation of fetal central nervous system development in utero.

Central Nervous System↗
PubMed1993

[Therapeutic efficacy of cefodizime in combination with minocycline against systemic infection caused by methicillin-resistant Staphylococcus aureus in immunocompromised tumour bearing mice].

The in vivo synergistic effect of cefodizime (CDZM) in combination with minocycline (MINO) against methicillin-resistant Staphylococcus aureus (MRSA) was investigated. A study of fractional effective dose (FED) index showed that either synergistic or additive effect was observed between CDZM and MINO. The postantibiotic effect (PAE) of MINO was not altered by the addition of CDZM. However, a strong synergistic bactericidal effect of CDZM and MINO against MRSA CT-18 was observed for more than 14 hours in the presence of immunocompromised tumour bearing murine polymorphonuclear leukocytes (PMN). These results suggest that the strong therapeutic efficacy of CDZM in combination with MINO was caused by synergistic bactericidal effect of the 2 drugs in the presence of PMN.

Animals↗
PubMed1992

A point mutation of low-density-lipoprotein receptor causing rapid degradation of the receptor.

The exons of the low-density-lipoprotein-(LDL)-receptor gene from a Japanese patient with homozygous familial hypercholesterolemia were amplified by the polymerase chain reaction (PCR), and their nucleotide sequences were determined. A point mutation from G to C was found in exon 9, which was expected to change Asp at position 412 to His. This amino acid change occurred within the epidermal-growth-factor-precursor homology domain of the LDL receptor, slightly impairing the processing from the precursor to the mature form and causing rapid degradation of the mature form in the fibroblasts of the patient. The mutant LDL-receptor gene transfected into COS-1 cells expressed a LDL-receptor protein with the same properties as the protein expressed in the fibroblasts of the patient; impaired processing and rapid degradation of the synthesized receptor protein. The mutation was identified in family members of the patient by dot-blot hybridization of PCR-amplified DNA with the mutant oligonucleotide. The family members carrying the mutant gene showed higher serum cholesterol levels than the others. However, their cholesterol levels were also greatly influenced by the apolipoprotein-E phenotype.

Base Sequence↗
PubMed1992

Molecular cloning and chromosomal localization of a human gene encoding D-amino-acid oxidase.

Genomic clones covering the entire sequence of the gene encoding human D-amino-acid oxidase (DAO) (EC 1.4.3.3), one of the principal and characteristic flavoenzymes of peroxisomes, were isolated from human placental genomic libraries with the aid of a previously cloned cDNA for human DAO as a probe. Nucleotide sequence analysis revealed that the gene, present as a single copy in the human genome, comprises 11 exons and spans 20 kilobase pairs. The protein sequences containing the catalytically important residues, Tyr-228 and His-307, are coded for by separate exons. Heterologous transcription initiation sites were identified by primer extension analysis, and the sequence of the 5'-flanking region of the DAO gene was found to show some features common to other mammalian genes, such as those of glucocorticoid and the cAMP-responsive element. An additional noteworthy feature is the presence of promoter-like sequences in the first intron of the gene. In addition, two sequences of alternating pyrimidine and purine nucleotides, (CA)20 and (CA)17, are also present in the first intron. Such sequences may play some role in the expression of the DAO gene in human tissues. With the use of genomic DNAs prepared from human and Chinese hamster somatic hybrid cells as templates for the polymerase chain reaction, the gene for DAO was localized to human chromosome 12.

Animals↗
PubMed1992

The human gene for renin-binding protein.

The human renin-binding protein (RnBP) gene was isolated from a human placental genomic library and characterized. The gene spans about 10 kilobases and consists of 11 exons separated by 10 introns. The 5'-flanking region and the exon-intron boundaries were sequenced. Residue G* in 5'-CGAG*TGG-3' was identified as the major transcription initiation site, and "GC" boxes were found in the vicinity of the cap site. No typical "TATA" or "CCAAT" box exists in the 5'-flanking region. The hydrophobic domain followed by a leucine-zipper motif in RnBP is encoded by the sixth exon. A fragment of the human RnBP gene (nucleotides -739 to +244) linked to the chloramphenicol acetyltransferase gene was transfected into human Wilms' tumor G401 and mouse L929 cells. The expression of this chimeric gene in G401 cells was 4-fold higher than that in L929 cells, the tissue-specific regulation of RnBP gene expression thus being suggested. The promoter for the RnBP gene was shown to be localized in nucleotides -35 to +244 on assaying of the promoter activity using deletion mutants of the chimeric constructs. The RnBP gene was found to be located in human chromosome X by means of polymerase chain reaction of hybrid DNAs from human and hamster somatic cells.

Animals↗
PubMed1992

Familial optic atrophy with negative electroretinograms.

We describe optic atrophy and abnormal electroretinographic findings in affected members from two families. Central vision failed in the second to third decade of life. Examination findings included visual acuities of 20/20 (1.0) to 20/500 (0.4), defective color vision, mild to moderate myopia, pericentral or centrocecal scotomas, and, in four of five patients, optic atrophy. Dark adaptometry found elevated cone and rod psychophysical thresholds. Bright flash electroretinograms showed normal a-wave amplitude and markedly subnormal b-wave amplitude. Rod responses were low normal to moderately subnormal in amplitude with normal implicit times. Photopic electroretinographic b-wave amplitudes varied from normal to mildly subnormal. Cone implicit times were normal. Because negative electroretinograms are not seen with other familial optic atrophies, the association of optic atrophy with the abnormal negative electroretinogram configuration in these patients represents a newly appreciated genetic disorder.

Adult↗
PubMed1992

Increased aqueous flare as a result of a therapeutic dose of mannitol in humans.

To evaluate the effects of mannitol on aqueous flare (aqueous protein concentration), we administered an intravenous clinical therapeutic dose to normal young adults (average age 20.1 years), to normal older adults (average age 61.5 years), and also to patients with diabetes mellitus, systemic hypertension, or pseudoexfoliation syndrome who were about to undergo intraocular surgery (average age 66.4 years). Protein and cell levels in the aqueous were determined with a device that measures laser light scatter in the aqueous. Mannitol increased the intensity of aqueous flare. In all subjects, the intensity of aqueous flare was greatest around 1 h following drug administration; the magnitude and duration of the aqueous flare increase were significantly greater in normal older adults than in normal young adults; the magnitude was essentially the same in older adults with and without disease. The effect reversed within 6 h of drug administration in normal subjects. We consider the findings to represent changes in actual aqueous protein concentration and discuss the possible causes of this phenomenon.

Adult↗