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Biomedical subjects

J Yasuda

Publications and source records attributed to J Yasuda.

At least 73 records · Page 4Linked to original sources
PubMed1996

Detection of microsatellite instability in cancers by arbitrarily primed-PCR fingerprinting using a fluorescently labeled primer (FAP-PCR).

The microsatellite mutator phenotype (MMP), detected as a change in the number of repeating units in hundreds of thousands of microsatellite sequences in the tumor cell genome, underlies the carcinogenesis of a variety of tumors including sporadic and hereditary nonpolyposis colon cancers. This enhanced microsatellite instability was discovered using arbitrarily primed polymerase chain reaction (AP-PCR) fingerprinting of DNA from colon cancers. In this study, we found an arbitrary primer that can amplify multiple DNA fragments containing repeated sequences, including the poly A tracts found in the Alu repeats of the human genome. The combined use of primer labeling with fluorescence and an automated DNA sequencing analysis of AP-PCR products (FAP-PCR) detected alterations in fingerprint bands in all DNA samples previously determined to belong to the MMP. Fluorescent AP-PCR fingerprinting using this single arbitrary primer provides a convenient and efficient method for detecting tumor specific fingerprint alterations that are usually undetectable by conventional fingerprinting.

Blotting, Southern↗
PubMed1996

[Relation of pulmonary hemodynamics and ventilation to tissue hypoxia during exercise in patients with tuberculosis sequelae].

We examined a relationship between tissue hypoxia and pulmonary hemodynamics or ventilatory capacity during rest and exercise in patients with tuberculosis sequelae. Nine patients performed exercise test until their symptom limit. Mean pulmonary arterial pressure (PPA) during exercise was plotted against cardiac index (C.I.) from rest to maximum exercise in each patient. In most of the patients, the changes of PPA showed linear relation with the C.I., and a slope (P-F slope) was obtained from the regression equation in each patient, and it was used as an index of circulatory disability during exercise. At the same time a coefficient of oxygen delivery (COD) was calculated and mixed venous oxygen tension (PvO2) was measured to evaluate a tissue hypoxia at rest and during exercise. The changes of COD were similar to those of PvO2 during exercise. COD positively correlated with PvO2 (R = 0.873, P < 0.01) from rest to maximal exercise, indicating that the values of PvO2 depended on those of COD. P-F slope negatively correlated with S.I. (R = -0.887, P < 0.01), oxygen transport (R = -0.780, P < 0.01), COD (R = -0.827, P < 0.01) and PvO2 (R = -0.760, P < 0.01) at maximal exercise. Whereas no significant relationship between ventilatory variables and COD or PvO2 was noted at maximal exercise. In conclusion, the patients with pulmonary tuberculosis sequelae who had a step P-F slope showed low mixed venous oxygen tension during exercise as a result of limited oxygen transport in consequence of low stroke volume.

Cell Hypoxia↗
PubMed1996

[AP-PCR and AP-PCR-SSCP analyses].

DNA fingerprinting by arbitrarily primed polymerase chain reaction (AP-PCR) is a simple and informative method to investigate genetic changes in cancers. The discovery of a mutator phenotype in hereditary non-polypotic colon cancer by the AP-PCR fingerprinting demonstrated the usefulness of this unbiased method. Due to its semiquantitative amplification of the target DNA, the AP-PCR fingerprinting can be applied to analyze numerical changes of chromosome fragments. A recent breakthrough of the chromosomal assignment of human AP-PCR products enabled us to do PCR-mediated molecular karyotyping of cancers. Application of single-strand conformation polymorphism (SSCP) analysis to AP-PCR products seems to be promising to elucidate somatic point mutations and hidden losses of heterozygosity in the anonymous regions in cancers.

Colonic Neoplasms↗
PubMed1996

[Prognostic value of acute pulmonary vascular response to oxygen inhalation in patients with chronic obstructive pulmonary disease].

Seventy-two patients with chronic obstructive pulmonary disease (COPD) underwent right heart catheterization when they were clinically stable and the relationship between length of survival and acute pulmonary vascular response to 100% oxygen inhalation was studied. Oxygen inhalation significantly reduced mean pulmonary arterial pressure (PPA), cardiac index (CI), and pulmonary arteriolar resistance (PAR). The percent change in PAR (% delta PAR) was used as an index of the acute pulmonary vascular response to 100% oxygen inhalation. Each patient was classified as a responder (% delta PAR > or = 15%) or a nonresponder (% delta PAR < 15%). The cumulative survival rates of these two groups were compared. Responders survived significantly longer than did nonresponders (mean survival times were 2571 days and 1432 days, respectively). The two groups did not differ significantly in anthropometic data, pulmonary hemodynamics, or blood gas data measured at base line during air inhalation. However, FEV1 and VC were significantly lower in nonresponders than in responders. The % delta PAR was not significantly related to age, PPA, PAR on air inhalation, FEV1, FEV1%, VC or VC%. We conclude that the pulmonary vascular response to oxygen inhalation (% delta PAR) may be an independent prognostic factor in patients with COPD.

Administration, Inhalation↗
PubMed1995

Loss of heterozygosity at 11p15 in malignant glioma.

Deletions of loci on chromosome 11p have been found frequently in several malignant tumors including gliomas, suggesting the presence of tumor suppressor genes. We analyzed 38 gliomas [26 malignant gliomas (grades III and IV) and 12 less malignant gliomas (grade I and II)] for loss of heterozygosity using microsatellite sequences on 11p as polymorphic markers. Loss of heterozygosity was found in 8 of 26 malignant gliomas (31%) but not in the less malignant gliomas. In the region with loss of heterozygosity, loci on 11p15.5-pter were commonly deleted. Our results suggest that a putative tumor suppressor gene involved in malignant progression of gliomas is located in an approximately 21-cM region on 11p15.5-pter.

Base Sequence↗
PubMed1995

Cloning and characterization of rat cellular nucleic acid binding protein (CNBP) cDNA.

We cloned and sequenced the cDNAs which code for rat cellular nucleic acid binding protein (CNBP). In-frame insertion/deletion differences were found among the clones at two sites in the open reading frame, suggesting alternative splicing of the message or the presence of multiple genes which code for this protein. The deduced amino acid sequence revealed that one rat CNBP sequence was completely identical to its human counterpart. This striking conservation, together with the fact that homologous genes have been found in various organisms including Schizosaccharomyces pombe, suggests that CNBP plays a basic biological role in eukaryotic cells. The recombinant GST-CNBP fusion protein produced in Escherichia coli bound to a G-rich single-stranded RNA and DNA in a sequence-specific manner.

Amino Acid Sequence↗
PubMed1995

Preliminary efficacy trial of Cymelarsan in mice artificially infected with Trypanosoma brucei brucei isolated from a dog in Zambia.

An efficacy trial of Cymelarsan on a Zambian strain of Trypanosoma brucei brucei was done. Twenty-five male mice were infected intraperitoneally with 10(6) of T. b. brucei isolated from a dog. Five groups of 5 mice were treated with 0 (control), 0.25, 0.5, 1.0 and 2.0 mg/kg Cymelarsan, respectively. The target was to achieve aparasitaemia for 30 days post-treatment, euthanising those that remained parasitaemic or relapsed before then. The 0.25 and 0.5 mg/kg groups remained parasitaemic although the parasitaemic levels were reduced. The 1.0 mg/kg group had a proportion of aparasitaemic mice. However, all mice in the 2.0 mg/kg group remained aparasitaemic until day 20 when 2 mice relapsed. These results suggested that more than 2.0 mg/kg was required to eliminate this strain.

Animals↗
PubMed1995

[Treatment of recurrent uterine endometrial cancer in adjuvant therapy with medroxyprogesterone acetate (MPA) in addition of etoposide].

In recent years, we treated recurrent uterine endometrial cancer by combined therapy including CDDP. But in poor cases, like renal failure and such, it is difficult to perform the therapy. Two cases of recurrent uterine endometrial cancer treated earlier with MPA were presently treated with an addition of etoposide. The first case was given etoposide (50 mg/m2/day 4 times for 21 days by oral administration). The target tumor mass was reduced in size, occult blood vanished, and the tumor marker was reduced. The other case was treated with etoposide, 50 mg/body/day for 21 days by oral administration, but because of diarrhea, the dose had to be decreased to 25 mg/body/day every day. The tumor marker was reduced and genital bleeding vanished. These cases suggested that etoposide-MPA combined therapy might be effective for recurrent uterine endometrial cancer of well-differentiated type.

Adenocarcinoma↗
PubMed1995

[Wilson-Jones type angiosarcoma with marked response to intrapleural administration of interleukin-2].

A 64-year-old woman was admitted to our hospital with a hemothorax after one year of therapy for angiosarcoma that had arisen from the skin of the head. The hemothorax was believed to have resulted from metastasis of the angiosarcoma. Interleukin-2 (IL-2) at a dose of 20 x 10(4) U once daily was administered intrapleurally. Clinical improvement was first observed on the second day after the first dose of IL-2. Increases in natural and in lymphokine-activated killer activity of lymphocytes in pleural effusion were found on the eighth day. Starting on the 16th day of IL-2 therapy, no more fluid was drained, so administration of IL-2 was stopped. The clinical course indicated that the pleural effusion disappeared not because of pleurodesis but because of the anti-cancer effects of IL-2. There were no marked side effects, and intrapleural administration of IL-2 may be useful in patients with hemothorax due to metastasis of angiosarcoma.

Female↗
PubMed1994

Cloning and characterization of a c-myc intron binding protein (MIBP1).

The cDNA for a c-myc intron 1 binding protein 1 (MIBP1) in the rat was isolated from lambda gt11 and lambda ZAPII cDNA libraries. Sequencing of the cDNA clones revealed a long ORF which encoded a putative protein of 2437 amino acid residues. This protein has two widely separated zinc finger regions, each of which carries C2H2 motifs. When expressed in E. coli as a fusion protein, part of the MIBP1 showed sequence-specific binding to the target sequence, i.e., a 9-bp sequence in the rat c-myc intron 1. MIBP1 is most likely the rat counterpart of human MHC binding protein-2 (MBP-2/HIV-EP2), based on the 86% similarity in nucleotide sequence and 93% similarity in amno acid sequence. Northern blotting revealed a high level of MIBP1 mRNA in the brain.

Amino Acid Sequence↗
PubMed1994

Potential for transmission of avian influenza viruses to pigs.

Pandemic strains of influenza A virus arise by genetic reassortment between avian and human viruses. Pigs have been suggested to generate such reassortants as intermediate hosts. In order for pigs to serve as 'mixing vessels' in genetic reassortment events, they must be susceptible to both human and avian influenza viruses. The ability of avian influenza viruses to replicate in pigs, however, has not been examined comprehensively. In this study, we assessed the growth potential of 42 strains of influenza virus in pigs. Of these, 38 were avian strains, including 27 with non-human-type haemagglutinins (HA; H4 to H13). At least one strain of each HA subtype replicated in the respiratory tract of pigs for 5 to 7 days to a level equivalent to that of swine and human viruses. These results indicate that avian influenza viruses with or without non-human-type HAs can be transmitted to pigs, thus raising the possibility of introduction of their genes into humans. Sera from pigs infected with avian viruses showed high titres of antibodies in ELISA and neutralization tests, but did not inhibit haemagglutination of homologous viruses, cautioning against the use of haemagglutination-inhibition tests to identify pigs infected with avian influenza viruses. Co-infection of pigs with a swine virus and with an avian virus unable to replicate in this animal generated reassortant viruses, whose polymerase and HA genes were entirely of avian origin, that could be passaged in pigs. This finding indicates that even avian viruses that do not replicate in pigs can contribute genes in the generation of reassortants.

Animals↗
PubMed1994

Growth control of influenza A virus by M1 protein: analysis of transfectant viruses carrying the chimeric M gene.

Analysis of fast-growing reassortants (AWM viruses) of influenza A virus produced by mixed infection with a fast-growing WSN strain and a slowly growing Aichi strain indicated that the M gene plays a role in the regulation of virus growth rate at an early step of infection (J. Yasuda, T. Toyoda, M. Nakayama, and A. Ishihama, Arch. Virol. 133:283-294, 1993). To determine which of the two M gene products, M1 or M2, is responsible for the growth rate control, one recombinant WSN virus (CWA) clone possessing a chimeric M gene (WSN M1-Aichi M2) was generated by using an improved reverse genetics and transfection system. The recombinant CWA virus retained the phenotype of both large plaque formation and early onset of virus growth. This indicates that the WSN M1 protein is responsible for rapid virus growth.

Amino Acid Sequence↗
PubMed1994

An occurrence of stomach impaction in ostriches (Struthio camelus) on a farm in Zambia associated with high mortality.

Fifty-one ostriches (Struthio camelus), 6 weeks old, were imported from Namibia and introduced onto a farm in Zambia. Soon after introduction, most of the birds manifested clinical symptoms such as anorexia and diarrhea and 19 birds died within 1 week. The proventriculus and gizzard in the 4 dead birds were full of solid masses of lucerne hay mixed with maize and consequently the gizzard was extremely impacted by them. Neither pathogenic bacteria nor parasites were detected from the autopsied birds and 8 fecal samples. After diagnosis, the ostrich feed was improved and a demulcent was given immediately; then all ostriches that remained on the farm recovered. In conclusion, these data confirmed that the present case was stomach impaction in ostriches.

Animal Feed↗
PubMed1994

Absence of activating mutations of the RAF1 protooncogene in human lung cancer.

Recently, the RAF protein has been demonstrated to be a direct effector of RAS protein in a RAS-mediated signal transduction pathway. Activations of the RAF1 gene by small mutations, such as point mutations in the kinase domain and a tetrapeptide insertion into conserved region 2, have been suggested from analyses of chemically induced lung cancers in mice and by site-directed mutagenesis. We investigated the presence of small mutations of the RAF1 gene in human lung carcinomas, especially in those not carrying the mutated RAS gene, expecting that aberrations of the RAF1 gene might play a role complementary to RAS gene mutations in tumorigenesis. Single-strand conformation polymorphism (SSCP) analysis of polymerase chain reaction products of DNA samples from 140 patients revealed no tumor specific mutations of the RAF1 gene in any of these specimens. This result suggests that mutations of the RAF1 gene are not involved in tumorigenesis in human lung.

Base Sequence↗