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Biomedical subjects

Y Eto

Publications and source records attributed to Y Eto.

At least 109 records · Page 6Linked to original sources
PubMed1997

Inhibition of carnitine synthesis protects against left ventricular dysfunction in rats with myocardial ischemia.

During myocardial ischemia, inhibition of the carnitine-mediated transportation of fatty acid may be beneficial because it facilitates glucose utilization and prevents an accumulation of fatty acid metabolites. We orally administered 3-(2,2,2-trimethyl hydrazinium) propionate (MET), an inhibitor of carnitine synthesis, for 20 days to rats. Then we evaluated left ventricular (LV) function during brief ischemia by using a buffer-perfused isovolumic heart model. After 15 min of reoxygenation after the transient ischemia, LV peak systolic pressure (PSP) almost completely returned to the baseline level in rats given MET (96 +/- 4%), whereas it was only partially (77 +/- 16%) recovered in the placebo-treated rats. We induced myocardial infarction in other rats by ligating the left anterior descending coronary artery. Then the animals were given MET for 20 days, and LV function was compared. In the placebo-treated rats (with myocardial infarction, but without drug treatment), LVPSP was lower than that in the sham group [108 +/- 19 (n = 10) vs. 136 +/- 15 mm Hg (n = 13); p < 0.05], and the time constant (T) of LV pressure decay was elongated (36 +/- 4 vs. 30 +/- 7 ms; p < 0.05). In MET-treated groups, however, neither PSP nor T differed from those in the sham group. In conclusion, inhibition of the carnitine-mediated transportation of fatty acid by MET protected against left ventricular dysfunction in acute and chronic myocardial ischemia.

Animals↗
PubMed1997

Differences in origin of the 1448C mutation in patients with Gaucher disease.

Gaucher disease (GD) can be caused by any of over 50 mutations of the gene of glucocerebrosidase (D-glucosyl acylsphingosine glucohydrolase; EC 3.2.1.45). The 1448T to C mutation is found among all ethnic groups. In Ashkenazi Jews, the patients who are homozygous for the 1448C mutation are associated with the neuropathic form of the disease, but this is not the case in Japanese patients. This present study was the analysis of the two haplotypes, the Pv1.1 and the liver/erythrocytes pyruvate kinase (PKLR), in Japanese GD patients who were homo- or heterozygous for the 1448C mutation, and comparison of the results with other ethnic patients with the same genotypes in order to show ethnic differences. Of 28 patients, 20 had type I disease (7 were homozygous for the 1448C), five had type II (1 was homozygous) and 3 had type III (all were heterozygous). In Japanese GD patients with the 1448C mutation, the two haplotypes showed complete matching in (+) or (-). The Pv1.1/PKLR(+) alleles accounted for 84.0% and this frequency was opposite to that reported in Ashkenazi Jews and other Caucasians. The 1448C homozygous state showed no obvious linkage with either of the haplotypes. From this haplotype analysis, it is postulated that the origin of the 1448C mutation in Japanese GD patients is different from that reported in other ethnic groups.

DNA Mutational Analysis↗
PubMed1997

Cloning and characterization of goldfish activin type IIB receptor.

We have cloned a full length cDNA coding for the activin type IIB receptor (GactRIIB) from the goldfish ovary. GactRIIB shares 73 and 70% amino acid identity in the extracellular domain, and 78 and 80% identity in the intracellular domain with the type IIB receptors of the mouse and Xenopus respectively. The intracellular domain of GactRIIB contains two serine kinase consensus sequences, DFKSRN and GTRRYMAPE, in agreement with the reports in other vertebrates that serine/threonine phosphorylation is involved in activin signal transduction. The identity of GactRIIB was confirmed by transient expression in the COS cells followed by activin binding. Iodinated human activin A bound to the GactRIIB-transfected cells and the binding could be completely inhibited by unlabeled activin. Affinity labeling revealed a band of about 85 kDa, which is in agreement with the reported type II receptors in other vertebrates. Together with the fact that activin is expressed in the goldfish ovary, the cloning of activin receptors from the ovary suggests paracrine and autocrine roles for activin in the goldfish ovarian functions.

Activin Receptors↗
PubMed1997

[Effects of recombinant human erythropoietin (rHuEpo) on the interactions between glomerular endothelial cells and mesangial cells: regulation of cell proliferation via endothelin (ET)-1].

To elucidate the effects of recombinant human erythropoietin (rHuEpo) on the interactions between glomerular endothelial cells (GENs) and mesangial cells (GMCs), we investigated whether or not cultured bovine GENs alter endothelin (ET)-1 secretion from bovine MCs and MC proliferate under basal or rHuEpo-stimulated conditions. Incubation for 24 hours with synthetic ET-1 stimulated MC in a dose-dependent manner. In addition, 100 pg/ml of ET-1 significantly stimulated MC proliferation after more than 12 hours incubation. Moreover, rHuEpo stimulated ET-1 secretion from GENs in a dose-dependent manner and showed less stimulation of ET-1 secretion from GMCs than GENs. DNA synthesis in both GENs and GMCs was significantly stimulated with more than 5 U/ml of rHuEpo. ET-1 secretion from GENs co-cultured with GMCs was higher than that from cultured GENs only. Conditioned medium, obtained from co-culture of GENs and GMCs, stimulated the proliferation of GMCs that were significantly inhibited with 10(-6) M approximately 10(-5) M BQ-123, a ETA receptor antagonist. These results suggest that rHuEpo directly stimulates the proliferation of GENs and GMCs, and this stimulatory effect is in part due to ET-1 secreted from these cells, especially GENs.

Animals↗
PubMed1996

Construction of high-resolution physical maps from yeast artificial chromosomes using restriction landmark genomic scanning (RLGS).

We have established a new system for chromosome-specific yeast artificial chromosome (YAC) contig construction using restriction landmark genomic scanning (RLGS-based YAC contig mapper). RLGS is a powerful tool for detecting more than 1000 restriction landmarks distributed on an entire genome in one procedure. In this system, RLGS is applied to sorted chromosomes to cover the target chromosome. Using these landmarks as guideposts, chromosome-specific YAC clones are then ordered. In this paper, we report the construction of a map for a human chromosome 21 YAC contig spanning q22.1 using this new approach. Applying RLGS to sorted chromosomes 21 enables detection of approximately 1400 spots (equivalent of 1050 PacI landmarks), covering the entire region of this chromosome. We constructed the 2.5-Mb YAC contig encompassing 21q22.1 with 66 spots (equivalent of 50 PacI landmarks). With this contig map, we could detect two deleted regions and chimerism in the YAC insert DNA. Our results demonstrated the usefulness of this approach for finding DNA alterations of YACs, such as deletions and chimerism.

Chimera↗
PubMed1996

Mutation screening of 17 Japanese patients with neuropathic Gaucher disease.

Using PCR and PCR-single strand conformation polymorphism (SSCP) we have identified gene mutations in 17 Japanese patients with neuropathic Gaucher disease (type 2, 9 cases; type 3, 8 cases). The L444P, F213I, D409H, and 1447 del 20 and 1447 ins TG mutations accounted for eight (type 2, 6; type 3, 2), seven (type 2, 2; type 3, 5), three (type 3), and three (type 2) alleles, respectively. Three alleles were unique. Ten alleles (type 2, 5; type 3, 5) could not be identified. The genotypes, D409H/?, L444P/?, L444P/F213I, and F213I/?, were identified in three, three, two, and two patients, respectively. Six patients had a unique genotype and none of the mutant alleles could be identified in one patient. The data indicate that the genotypes in Japanese patients with neuropathic Gaucher disease are found to be heterogeneous and the genotype prevalence and mutated alleles are unique.

Alleles↗
PubMed1996

Gene therapy for metachromatic leukodystrophy.

Metachromatic leukodystrophy (MLD) is an inherited metabolic disease which is characterized by a deficiency of arylsulfatase A (ASA). This deficiency causes progressive accumulation of cerebroside sulfate in oligodendrocytes (OL) in the brain, resulting in dysmyelination. Approaches being developed by the authors to treating MLD are based on direct delivery of ASA genes into the brain. In the present report, it has been shown that the recombinant adenovirus (Adex1SRLacZ) was able to transduce the OL very efficiently. Moreover, primary fibroblasts from MLD patients were exposed to recombinant adenovirus expressing the ASA gene (Adex1SRASA) and the cells expressed the transgene. The influence of overexpression of ASA on the activity of other sulfatases was also tested in fibroblasts from patients with MLD using a retrovirus vector (MFG-ASA). It was demonstrated that the overexpression of ASA reduces the activity of various sulfatases by a small amount but does not induce an accumulation of glycosaminoglycan. These results indicate that the influence of ASA overexpression on other sulfatases is different from that of the N-acetygalactosamine-4-sulfatase overexpression in a previous report. It was concluded that the correction of ASA deficiency by a recombinant adenovirus that potentially could be used to transfer the gene to the brain, and gene therapy for MLD based on gene transfer of the ASA gene to mutant cells will be feasible because the overexpression of ASA in cells does not lead to profound deficiency of other sulfatases or result in a new phenotype.

Adenoviridae↗
PubMed1996

Clinical and genetic studies of five fatal cases of Japanese Gaucher disease type 1.

Five fatal cases of Japanese patients with type 1 Gaucher disease were studied. The causes of death included hemorrhage secondary to esophageal varices (two cases), respiratory distress (one case), hepatic failure (one case) and postoperative sepsis (one case). All of the patients had previous splenectomies, four patients had bone involvement and hepatic cirrhosis. The identified Gaucher genotypes were 1448C/1213G, 1603T/1603T, 1448C/1390G, and 1213G/1213G. The prognosis of type 1 Gaucher disease is generally good. We propose that patients with a similar clinical course and genotype to those presented in the present study should receive prompt comprehensive treatment. Patients with the 1213G mutation, pulmonary and liver involvement and a previous splenectomy should be considered as candidates for early vigorous treatment.

Adolescent↗
PubMed1996

[Study on septicaemia in infants and children in the past 20 years. Part 1. An analysis of causal organisms].

Causal organisms and their changes were evaluated in 158 cases of septicaemia admitted to Jikei University Hospital from 1975 to 1994. Eighty patients (50.6%) were aged less than 1 year, and 37 patients (23.4%) were newborns. The average mortality rate was 18.4%. The mortality rate between 1975 and 1984 was 26.8%, and that of the past 10 years (from 1985 to 1994) decreased to 13.7%. Staphylococcus aureus (29 cases, 19.4%) was the most common pathogens isolated, followed by Pseudomonas sp. (24 cases, 15.2%), Escherichia coli (19 cases, 12.0%), and Haemophilus influenzae (18 cases, 11.4%). H. influenzae, Acinetobacter sp., Streptococcus pneumoniae and Group B streptococcus (GBS) increased in the past 10 years (from 1985 to 1994), compared with the preceding 10 years (from 1975 to 1984). The mortality rate of Klebsiella sp. septicaemia (28.6%) was highest, followed by Pseudomonas sp. (25.0%), S. aureus (24.1%), S. pneumoniae (22.2%). H. influenzae and Acinetobacter sp. septicaemia were not fatal. E. coli and GBS were common among neonates and patients aged less than 1 year. H. influenzae septicaemia occurred mainly in patients with meningitis, in those younger than school age. Acinetobacter sp. was common among neonates and children with leukaemia Pseudomonas sp., Klebsiella sp., and Acinetobacter sp. were mainly detected in patients with underlying diseases. E. coli, H. influenzae, S. pneumoniae and GBS were mainly detected in patients without underlying diseases.

Adolescent↗
PubMed1996

[Study on septicaemia in infants and children in the past 20 years. Part 2. An analysis of factors that prescribe for the prognosis].

Underlying diseases, complications, clinical findings, and laboratory findings were evaluated in 158 cases of septicaemia admitted to Jikei University Hospital from 1975 to 1994, in order to conjectured factors that prescribe for the prognosis. 50% of the patients had underlying diseases. Malignancy including leukaemia (31 cases, 39.2%) was the most common underlying disease, followed by low birth weight infant (17 cases, 21.5%), aplastic anemia (9 case, 11.4%), and congenital heart disease (7 cases, 8.9%). The death rate for patients with underlying disease (27.8%) was significantly greater than the mortality for normal patients with septicaemia (8.9%) (p < 0.05). Meningitis (24.7%) was the most common complication, followed by DIC (19.6%), shock (15.2%), and pneumonia (10.8%). The mortality rate of septicaemia complicated by shock was 66.7% (p < 0.01), and that complicated by DIC was 45.2% (p < 0.01). The mortality rate for patients with the clinical findings of respiratory distress, cough, abdominal distention, cyanosis, splenomegaly, or peripheral coldness was more than 40% and significantly greater (p < 0.01). Mortality rate in patients with granulocyte counts of < 4.000/mm3, platelet counts of < 5 x 10(4)/ mm3, total protein of < 5.0 g/dl, or ESR of < 20 mm/hr were significantly greater (p < 0.01) than those in patients with normal laboratory findings. Coincidence rate of blood and stool cultures was 57.9% for E. coli, and 28.6% for Klebsiella sp., and that of blood and throat cultures was more than 30% for Pseudomonas sp., Haemophilus influenzae, and Staphylococcus aureus. In the study of antimicrobial susceptibility for microorganisms isolated, the number of drug resistant S. aureus had increased in the last 10 years.

Adolescent↗
PubMed1996

Demonstration of activin in normal pituitary and in various human pituitary adenomas by immunohistochemistry.

Inhibins and activins have been known to modify the secretion of various pituitary hormones. To study whether inhibins and activins are present in human pituitary tissues, immunohistochemical studies with antisera to activin A and inhibin alpha subunit were performed on 9 human pituitary adenoma tissue specimens and one sample of normal pituitary tissue adjacent to one adenoma. Activin immunoreactivities were demonstrated in the cytoplasms of one GH and one PRL and two non-functioning adenomas and one normal pituitary tissue, but they were negative in one PRL, one ACTH, one FSH and two non-functioning adenomas. Thus, the presence and absence of activin in the same type of adenoma in regard to hormone production, suggested that the difference in immunostaining simply reflected the difference in the activin concentration. In contrast to this, inhibin alpha subunit immunoreactivity was not found in any of the tissues studied. These data suggested a local synthesis of activin in the normal pituitary as well as various kinds of pituitary adenoma tissues and its local role in the human pituitary gland.

Activins↗
PubMed1996

Anti-activin A antibody (IgY) specifically neutralizes various activin A activities.

Activin A (beta A beta A), originally isolated from ovarian follicular fluids as a follicule-stimulating hormone (FSH) secretion stimulator, has also been identified as an erythroid differentiation factor (EDF), a neuron survival factor and a mesoderm-inducing factor. Thus, activin A is a multifunctional factor, and further studies on its physiological function are important. However, it is very difficult to produce a specific antibody to neutralize the activity of activin A because of its highly conserved amino acid sequence across mammalian species. In this study, we succeeded in generating an antibody against activin A, which can neutralize several activities of activin A, such as the stimulation of FSH secretion from pituitary cells and the induction of the differentiation of erythrocytes in vitro. This antibody did not affect the activity of activin B (beta B beta B), which induces the differentiation of erythrocytes in vitro, and the activity of inhibin A (alpha beta A), which inhibits FSH secretion from pituitary in vitro, but slightly neutralized that of activin AB (beta A beta B). Western blotting analysis showed that this antibody recognized both dimeric and monomeric forms of the beta A subunit of activin and inhibin. These results suggest that this antibody recognizes the beta A subunit of activin and specifically neutralizes the activity of a dimer of the beta A subunit, activin A. Furthermore, by the addition of this antibody to the culture medium, the development of murine embryos was suppressed, suggesting that endogenous activin A plays an important role in murine development. These results indicate the usefulness of this antibody for studies of endogenous activin actions.

Activins↗
PubMed1996

[MRI findings of anterior spinal artery syndrome in childhood].

We reported two cases of anterior spinal artery syndrome in childhood evaluated by MRI of the spinal cord. The T2-weighted MRI revealed high signal intensity in the anterior region of spinal cord in both cases. These findings might be related with edema of the ischemic region. Several years later, the regions of the spinal cord showed atrophic changes. The high signal intensity on the T2-weighted MRI was characteristic of the anterior spinal artery syndrome.

Arteries↗
PubMed1996

[Molecular studies of Gaucher disease].

Gaucher disease is characterized by a deficiency of glucocerebrosidase and hence the accumulation of glucocerebroside in visceral organs such as liver and spleen. Clinically, this disorder can be classified into three types according to clinical phenotype; types I, II and III. More than 50 different gene mutations have been reported previously in the world. Gene mutations in the Japanese showed that the most common mutations are LEU444Pro and Phe313Ileu mutations, accounting for about 40% and 10% of the total alleles, respectively. In the Japanese, there were no mutations in N370S and 84GG among the Japanese. Gaucher disease is recently treated by the administration of purified placental glucocerebrosidase. Aided by the Japanese Ministry of Welfare, six patients with Gaucher disease have been under treatment for almost two years. All cases responded to this treatment as seen in Hb value, platelet count, plasma acid phosphatase value, ACE value, and size of liver and spleen. Gene therapy for Gaucher disease is also currently under consideration.

Asian People↗
PubMed1996

Mitochondrial encephalomyopathies preceded by de-Toni-Debré-Fanconi syndrome or focal segmental glomerulosclerosis.

We report two rare cases of mitochondrial encephalomyopathies which were preceded by renal diseases. One occurred in an 11-year-old girl diagnosed with Kearns-Sayre syndrome, which was preceded by de-Toni-Debré-Fanconi syndrome 8 years previously. The other occurred in a 14-year-old girl diagnosed with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes, who developed focal segmental glomerulosclerosis 3 years prior to confirmation of the diagnosis. Tissue from both patient demonstrated morphological abnormalities of the mitochondria in the distal renal tubular epithelium and leiomyocytes of the small renal artery. The present cases illustrate various clinical and morphologic evidence of renal diseases which may further our understanding of mitochondrial encephalomyopathies.

Adolescent↗
PubMed1996

[Batten disease].

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Adolescent↗