Search PubMed⌕ Search

Biomedical subjects

M Wada

Publications and source records attributed to M Wada.

At least 505 records · Page 28Linked to original sources
PubMed1990

Suppression of immunological responses in rabbits experimentally infected with bovine leukemia virus.

Ten 2- to 4-month-old rabbits were inoculated subcutaneously with bovine leukemia virus (BLV)-infected bovine or sheep cells. By 6 weeks after inoculation all ten rabbits had converted to BLV antibody-positive, and BLV or BLV antigen was detected in lymphocytes from most of the rabbits tested, although there were few antigen-producing cells. Three rabbits showed continuous respiratory symptoms after infection and one died with pneumonia. Humoral immune responses against mouse serum were significantly suppressed in BLV-infected rabbits compared with non-infected control rabbits. The lymphocyte blastogenesis response was also suppressed in BLV-infected rabbits. At the time of necropsy, six rabbits showed pulmonary lesions; however, none of the BLV-infected rabbits had tumors during an observation period of over 1 year.

Animals↗
PubMed1990

Yeast artificial chromosomes containing human Xq24-Xq28 DNA: library construction and representation of probe sequences.

A library of yeast artificial chromosomes (YACs) with human DNA inserts has been assembled from a human/hamster somatic cell hybrid containing Xq24-Xqter human DNA. Screening of the agar-embedded transformants for human DNA used a manifold of 3000 stainless-steel pins to transfer colonies onto the surface of media. This facilitated the recovery of the 1 in 300 clones that contained a human DNA insert (the remainder had hamster DNA and were discarded). The library described here consists of about two genomic equivalents (102 Mb) of human DNA in 467 clones: 167 were generated by EcoRI partial digestion and contain 25.5 Mb of human DNA; 252 used partial digestion with TaqI and cover 64.2 Mb; and 48 were from sheared DNA inserts and cover 11.7 Mb. Clones were screened by hybridization with 70 probes previously assigned to Xq24-Xq28. Eleven probes did not hybridize to any YACs in the library, and 16 probes hybridized to one YAC each, 23 to two, 13 to three, and 7 to four. Also, individual YACs large enough to detect features like the clustering of polymorphic sequences in subregions of Xq24-Xqter have been obtained. For example, XY58 contained five probe sequences previously independently isolated. The overall yield of YACs containing probe sequences was indistinguishable from Poisson statistical expectations for random cloning (P = 0.9). Thus, YAC libraries such as the one described here can include most, if not all, of the sequences in the source DNA from which the library is derived. These results support the possibility that YACs may provide a reliable bridge between linkage studies and conventional recombinant DNA analyses in mapping of the human genome.

Animals↗
PubMed1990

Two forms of messenger RNA encoding rat liver mannan-binding protein are generated by differential utilization of polyadenylation sites of one transcript.

Rat liver mannan-binding protein (R-L-MBP) is a lectin specific for mannose and N-acetylglucosamine. Northern blot hybridization analysis with a R-L-MBP cDNA (0.9 kb), which we isolated previously [Oka, S., Itoh, N., Kawasaki, T., & Yamashina, I. (1987) J. Biochem. 101, 135-144], revealed that R-L-MBP was encoded by two species of mRNA of 1.4 and 3.5 kb long, respectively. Analysis of a newly isolated cDNA clone of 3.3 kb long showed that the sequence of the open reading frame of the 3.5 kb mRNA was completely identical to that of the 1.4 kb mRNA. The 3'-untranslated region of the 3.5 kb mRNA contained two inverted copies of the previously described identifier (ID) sequence, which is a repetitive element of the rat genome [Milner, R.J., Bloom, F.E., Lai, C., Lerner, R.A., & Sutcliffe, J.G. (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 713-717]. Southern blot analysis of rat genomic DNA digested with restriction enzymes suggested that each mRNA species arises from one gene, with the differences in size most easily being accounted for by differential utilization of the polyadenylation sites of one transcript.

Amino Acid Sequence↗
PubMed1990

Selection of radioresistant cells by vitamin A deficiency in a small cell lung cancer cell line.

Radiation sensitivity of a human small cell lung cancer cell line, Lu-134-B cells, cultured in serum-supplemented medium and of cells transferred to and cultured in delipidized serum-supplemented (vitamin A-deficient) medium was studied. The cells cultured in serum-supplemented medium showed the phenotype of classic small cell lung cancer sensitive to radiation, while cells transferred to delipidized serum-supplemented medium showed partial squamous cell differentiation and became resistant to radiation. These results suggest that some small cell lung cancer cells in vitro change their morphology and radiosensitivity depending on the culture conditions. The change in radiosensitivity was reproducible, and was not reversible by culture of the radioresistant cells in delipidized serum-supplemented medium with addition of retinoic acid (vitamin A-sufficient medium) for two months, although squamous cells disappeared. Acquisition of radioresistancy was considered to occur as the result of clonal selective growth in delipidized medium of a minor cell population in the original cell culture, based on a study of chromosome number. It was also found that there was no association of myc-family oncogenes with the changes of radiosensitivity in this cell line.

Animals↗
PubMed1990

Effect of recombinant human erythropoietin on new anaemic model rats induced by gentamicin.

The effects of recombinant human erythropoietin (r-HuEPO) on haematological parameters were studied in rats in which uraemia and anaemia had been induced by gentamicin, an aminoglycoside antibiotic and a nephrotoxic agent. After the occurrence of slight polycythaemia, the red blood cell count, haematocrit and haemoglobin concentration decreased by 20-30% compared with those of the control (saline-injected) rats. At the end of gentamicin treatment, the endogenous serum EPO level had decreased to about 40% compared with that of control rats. Gentamicin-treated rats showed marked elevation of blood urea nitrogen, extensive tubular necrosis in the kidney and haemosiderin deposition in the spleen. In the osmotic fragility test, the fragility of erythrocytes significantly increased compared with that of control rats. These findings indicate that the anaemia induced by gentamicin is due not only to a deficiency of EPO but also to an enhancement of fragility of erythrocytes in an azotaemic environment. The administration of r-HuEPO during anaemia markedly increased red blood cell count, haematocrit and haemoglobin concentration. It is suggested that a gentamicin-treated rat is a useful and convenient anaemic model and r-HuEPO is useful for treatment of anaemia in acute renal failure.

Anemia↗
PubMed1990

Effects of physical training on febrile and acute-phase responses induced in rats by bacterial endotoxin or interleukin-1.

1. We investigated the effect of physical training on febrile and acute-phase responses induced in rats by intravenous (I.V.) injection of bacterial endotoxin or human recombinant interleukin-1 beta (IL-1). Physical training was performed by swimming for 1 h per day, 5 days a week. After four weeks of training, animals were used in the experiments. 2. The I.V. injection of endotoxin produced a febrile response in the trained group but not in the control group. However, there were no statistically significant differences between febrile responses induced by the I.V. injection of IL-1 in the control and trained groups. 3. The I.V. injection of endotoxin significantly decreased the plasma concentration of iron and zinc and increased the plasma fibrinogen concentration in both the control and the trained groups. However, the decreases in the plasma iron and zinc concentrations in the trained group were significantly greater than those in the control group. The I.V. injection of endotoxin increased the circulating leucocyte count in the only trained group. 4. The I.V. injection of IL-1 significantly decreased the plasma concentration of iron and zinc and increased the plasma fibrinogen concentration and the circulating leucocyte count in both the control and the trained groups. However, between the two groups, no significant differences in the values of acute-phase reactants were observed. 5. The present results suggest that the ability to produce cytokine(s) to induce febrile and acute-phase responses is enhanced by physical training. However, physical training has no effect on the febrile and acute-phase responses induced by IL-1.

Acute-Phase Reaction↗
PubMed1990

Uncomplicated acute diverticulitis of the cecum and ascending colon: sonographic findings in 18 patients.

To determine the sonographic features of uncomplicated acute diverticulitis of the cecum and ascending colon, the sonographic findings in 534 patients who presented with right lower quadrant pain were reviewed. Of these, 18 patients had uncomplicated acute diverticulitis of the cecum and ascending colon. The diagnosis was confirmed by surgery (one patient), clinical course (17 patients), CT (eight patients), or contrast enema (11 patients). On sonography, a round or oval focus of varying echogenicity, which protruded from a segmentally thickened colonic wall and was surrounded by a hyperechoic area, was seen in all 18 patients. These were hypoechoic foci (12 patients), hypoechoic foci with internal strong echoes (three patients), and echogenic shadowing foci with surrounding hypoechoic bands (three patients). Extraluminal gas (one patient) and thickening of lateroconal fascia (six patients) were seen also. Findings of enlarged appendix, frank abscess, and ascites were absent. All patients, including the one who had laparotomy, were successfully treated medically for diverticulitis. Of 515 patients without diverticulitis, in only one patient with acute appendicitis did sonography show a hypoechoic protruding focus. Our experience indicates that the major sonographic finding in patients with uncomplicated acute diverticulitis of the right colon is a hypoechoic round or oval focus protruding from a segmentally thickened colonic wall.

Acute Disease↗
PubMed1990

Dye penetration of the smear layer and fluoride application to the dentin surface.

A smear layer is formed after cavity or root canal preparation. The aim of the present study was to reinforce the dental surface in order to prevent the invasion of foreign irritants, by treating the smear layer with fluoride. Dentinal samples whose surfaces had been washed with water after the formation of a smear layer, and corresponding samples without washing, were examined by the dye penetration test, and the results were compared. Although there was no significant difference between the two groups of samples, dye penetration was suppressed by about 30% in washed samples, whereas the suppression was 20% in unwashed samples. When washed samples were treated with 1.0% SnF2, 10.0% SnF2, 7.5% Na2PO2F, 15% Na2PO2F, APF, 10 mM In(NO3)3, 100 mM TiF3, 50 mM TiF3, or 10 mM TiF3, samples washed after treatment with 1.0% SnF2 showed a dye penetration suppression of about 60% as a whole, in comparison with samples having no smear layer. Hardly any suppression of dye penetration was observed after treatment with other fluorides.

Acid Etching, Dental↗
PubMed1990

[Myelodysplastic syndrome (RAEB-T) occurring after adjuvant chemotherapy for colon and rectum cancers].

A 67-year-old man was admitted to our hospital because of bleeding tendency and high fever. The patient had a past history of gastrectomy and transverse colectomy for cancer of transverse colon at age 57, and rectum resection for rectum cancer at age 59. After these operations, Tegafur 645 g, MMC 56 mg, and Ara-C 560 mg were administered for about 6 years. Hematological examinations revealed hemoglobin of 7.7 g/dl, white cell count of 9,500/microliters with 8% myeloblasts, and platelet count of 7,000/microliters. A diagnosis of myelodysplastic syndrome (RAEB-T) was made from the finding of bone marrow smear, which showed 28% myeloblasts, and neutrophils and megakaryocytes with morphologically abnormal nuclei and cytoplasms. Chromosomal banding study of the bone marrow cells revealed -5, -8, 7q- in all analyzed cells. These findings suggest that the preceding adjuvant chemotherapy is probably related to the occurrence of myelodysplastic syndrome.

Aged↗
PubMed1990

[Spontaneous complete remission in a patient with acute monocytic leukemia].

A spontaneous complete remission was observed in a 47-year-old female with acute monocytic leukemia. Resolution of all abnormalities, including systemic papule, thrombocytopenia, increased numbers of immature monocytoid cells in the peripheral blood and bone marrow, elevation of serum lysozyme and LDH, and trisomy 8 on chromosome analysis, occurred without any treatment. Moreover, the remission was not associated with any infection or blood transfusion, and is persistent for 12-month duration.

Chromosomes, Human, Pair 8↗
PubMed1990

Human Xq24-Xq28: approaches to mapping with yeast artificial chromosomes.

One hundred twenty-seven yeast strains with artificial chromosomes containing Xq24-Xqter human DNA were obtained starting from a human/hamster somatic cell hybrid. The clones were characterized with respect to their insert size, stability, and representation of a set of Xq24-Xqter DNA probes. The inserts of the clones add up to 19.3 megabase (Mb) content, or about 0.4 genomic equivalents of that portion of the X chromosome, with a range of 40-650 kb in individual YACs. Eleven clones contained more than one YAC, the additional ones usually having hamster DNA inserts; the individual YACs could be separated by extracting the total DNA from such strains and using it to retransform yeast cells. One of the YACs, containing the probe for the DXS49 locus, was grossly unstable, throwing off smaller versions of an initial 300-kb YAC during subculture; the other YACs appeared to breed true on subculture. Of 52 probes tested, 12 found cognate YACs; the YACs included one with the glucose-6-phosphate dehydrogense gene and another containing four anonymous probe sequences (DX13, St14, cpx67, and cpx6). Xq location of YACs is being verified by in situ hybridization to metaphase chromosomes, and fingerprinting and hybridization methods are being used to detect YACs that overlap.

Animals↗
PubMed1990

[Preoperative therapeutic embolization for massive hemoptysis from bronchial collaterals in tetralogy of Fallot--a case report successfully treated by total correction].

Hemoptysis from bronchial collateral arteries in cyanotic heart diseases is a troublesome complication. We report a case of Tetralogy of Fallot presented with massive hemoptysis which was successfully treated with transcatheter therapeutic embolization prior to the radical operation. A 28-years old man was admitted to our hospital because of hemoptysis and dyspnea. On the day of admission, he had a massive hemoptysis and became asphyxic. Diagnostic cardiac catheterization performed next day revealed Tetralogy of Fallot. Bronchial arteriogram demonstrated large bronchial collateral arteries with heavy staining around the right lower lobe bronchus. Therapeutic embolization with Gelfoam was performed and the hemostasis was obtained. The radical operation was performed 4 months later. Before cardiopulmonary bypass, the right bronchial artery was ligated. He was weaned from the extracorporeal circulation under the stable circulatory condition, and respirator on the first post operative day without any complications, and he was discharged on the 57th day after the operation. We emphasize the efficacy of therapeutic embolization of the well developed bronchial collateral arteries as a pretreatment of hemoptysis in the cyanotic heart disease.

Adult↗
PubMed1989

Participation of the hup gene product in site-specific DNA inversion in Escherichia coli.

The closely related Escherichia coli genes hupA and hupB each encode a bacterial histone-like protein HU. We report here that DNA inversion mediated by hin, gin, pin and rci but not by cin is blocked in a hupA hupB double mutant, although inversions in these systems occur in the hupA or hupB single mutant as efficiently as in the wild-type strain. These findings show that HU protein participates in site-specific DNA inversion in E. coli and that only one subunit, either HU-1 or HU-2, is sufficient for this inversion.

Bacterial Proteins↗
PubMed1989

Participation of hup gene product in replicative transposition of Mu phage in Escherichia coli.

The closely related Escherichia coli genes hupA and hupB each encode a bacterial histone-like protein HU. We report here that mutator phage Mucts62 was unable to replicate in a hupA hupB double mutant, although it could replicate in hupA or hupB single mutant as efficiently as in the wild-type strain. Mucts62 was able to lysogenize the double mutant at 30 degrees C; cell killing occurred when the lysogen was incubated at 42 degrees C, but did not result in phage production. High-frequency non-replicative integration of Mu into host genomic DNA soon after infection could not be detected in the hupAB double mutant. These results provide the evidence that HU protein is essential for replicative transposition of Mu phage in E. coli, and also participates in high-frequency conservative integration.

Bacterial Proteins↗
PubMed1989

Relationship between sugar chain structure and biological activity of recombinant human erythropoietin produced in Chinese hamster ovary cells.

Two forms of erythropoietin, EPO-bi and EPO-tetra, with different biological activities were isolated from the culture medium of a recombinant Chinese hamster ovary cell line, B8-300, into which the human erythropoietin gene had been introduced. EPO-bi, an unusual form, showed only one-seventh the in vivo activity and 3 times higher in vitro activity of the previously described recombinant human EPO (standard EPO). In contrast, EPO-tetra showed both in vivo and in vitro activities comparable to those of the standard EPO. EPO-bi, EPO-tetra, and the standard EPO had the same amino acid composition and immunoreactivity. However, structural analyses of their N-linked sugar chains revealed that EPO-bi contains the biantennary complex type as the major sugar chain, while EPO-tetra and the standard EPO contain the tetraantennary complex type as the major sugar chain. From examination of various preparations of recombinant human EPO, we found a positive correlation between the in vivo activity of EPO and the ratio of tetraantennary to biantennary oligosaccharides. These results suggest that higher branching of the N-linked sugar chains is essential for effective expression of in vivo biological activity of EPO.

Animals↗
PubMed1989

The occurrence of a ca-dependent period in the red light-induced late g1 phase of germinating adiantum spores.

The first cell cycle of Adiantum spores, which is induced by red light (R), was studied with regard to its temporal dependence on Pfr (the active form of phytochrome) and Ca(2+). Responses were quantified with increases of the spore content of DNA, thus limiting the investigation to the reactions taking place before the S phase of the cell cycle (i.e. during G0/G1/S transitions). Spores hydrated for more than 2 days in the standard medium (includes 1 millimolar free Ca(2+)) showed, after stimulation with a saturating R pulse, an increase of DNA beginning at about 25 hours and saturating at about 55 hours. Reversal by far-red light of the inductive effect of R was used to examine the temporal requirement for Pfr. Spores became dependent on the supply of external Ca(2+) when incubated in a low Ca medium (32 nanomolar free Ca(2+) with 10 millimolar EGTA); this culture condition was used, after observing that the DNA increase occurs similarly if Ca(2+) is supplied after the R pulse, to examine the temporal requirement for external Ca(2+). It was concluded that the G1 phase of the spore is separated into three subphases: (a) the Pfr-dependent period which immediately follows the R pulse and varies among individual spores from a few to about 25 hours, (b) the Ca(2+)-dependent period (about 10 hours) which occurs immediately before the S phase, and (c) a gap (15-20 hours) between the two periods. In the Ca(2+)-dependent period, spores require the presence of extracellular Ca(2+). This period occurs only during a determined time after the R pulse, and the competence of spores to enter the S phase is lost sharply if external Ca(2+) is not available continuously during this period.

Journal Article↗