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Biomedical subjects

Y Murakami

Publications and source records attributed to Y Murakami.

At least 595 records · Page 33Linked to original sources
PubMed1994

Isolation and serological characterization of porcine reproductive and respiratory syndrome (PRRS) viruses from pigs with reproductive and respiratory disorders in Japan.

Three porcine reproductive and respiratory syndrome viruses (PRRSVs) were successfully isolated from stillborn piglets and fattening pigs derived from different herds affected either with an epizootic reproductive failure or a severe chronic respiratory distress in Japan. The isolates were reacted with antisera against both European (Lelystad virus) and American (strain 46448) PRRSVs in indirect immunofluorescence (IIF). However, cross immunoperoxidase monolayer assay revealed the close serological relationships between the Japanese isolates and American PRRSV, but not between the Japanese isolates and the European PRRSV. The data of preliminary serological survey with IIF technique showed a high frequency of antibody positive pigs against both Japanese isolate and the American PRRSV, whereas a low frequency of antibody positive pigs against the European PRRSV, on herds which have had clinical episodes of PRRS-like diseases. These results indicate that PRRSVs are prevalent in Japan, and suggest that the antigenicities of the prevalent PRRSVs are more closely related to those of the American than the European PRRSVs.

Animals↗
PubMed1994

Body composition assessed by bioelectrical impedance analysis (BIA) and the correlation with plasma insulin-like growth factor I (IGF-I) in normal Japanese subjects and patients with acromegaly and GH deficiency.

Body composition was assessed by bioelectrical impedance analysis (BIA) in 100 Japanese normal adults, 9 patients with acromegaly and 11 patients with growth hormone (GH) deficiency. Body weight (BW) was greater in normal males than in normal females. Percent body fat (BF/BW) was greater in females than in males and was increased with age in both sexes. Percent total body water (TBW/BW) was less in females than in males. Although percent extracellular water (ECW/BW) was not different between both sexes, the ECW/TBW ratio was greater in females than in males. Percent body cell mass (BCM/BW) was lower in females than in males. The patients with acromegaly had a lower percent BF but a higher percent TBW, percent ECW and ECW/TBW ratio than normal subjects, while the patients with GH deficiency had a higher percent BF and ECW/TBW ratio, but lower percent TBW. Percent body cell mass (BCM/BW) was higher in acromegaly and lower in GH deficiency than in normals. There was a negative correlation (r = -0.62) between plasma IGF-I levels and percent BF, whereas a positive correlation (r = 0.51) was found between the plasma IGF-I level and percent BCM. It is suggested, therefore, that body composition is affected by sex and age in normals, and by GH secretion in patients with pituitary dysfunction. Plasma IGF-I levels may be one of the factors responsible for alterations in body composition.

Acromegaly↗
PubMed1994

Effect of smear layer removal agent and/or fluoride on the surface of dentin.

A study was conducted to observe the effectiveness of an EDTA-based agent, Tubulicid Red, and a polyacrylic acid-based agent, Dentin Conditioner, for removal of the smear layer from a prepared dentin surface, with or without a fluoride dentin reinforcing agent, using the dye penetration test and scanning electron microscopy (SEM). Bovine mandibular first and second incisors were used. After removal of the enamel, the smear layer on the dentin surface was treated with 38% H3PO4, Tubulicid Red, Dentin Conditioner, 1% NaF, 1% SnF2, Tubulicid Red (including 1% SnF2), Dentin Conditioner (including 1% NaF) and Dentin Conditioner (including 1% SnF2). In the dye penetration test, Dentin Conditioner (including 1% SnF2) was the most effective agent for preventing dye penetration. SEM evaluation of the dentin surface after treatment with the smear layer removal agents and/or fluorides showed that the smear layer was removed by H3PO4 and Dentin Conditioner. However, dentinal plugs remained after treatment with Dentin Conditioner alone. The other agents left some layers on the dentin surface.

Acid Etching, Dental↗
PubMed1994

[Valvulo-annuloplasty for atrioventricular valvular regurgitation in univentricular heart and double outlet right ventricle].

Valvulo-annuloplasty for atrioventricular (AV) valvular regurgitation was performed in 10 patients with univentricular heart and double outlet right ventricle. Kay annuloplasty alone was employed in three patients with a quadricuspid or tricuspid common AV valve. Two of them died after the operation and the remaining one is waiting for reoperation because of recurrence of severe AV valve regurgitation. The suturing-up of free margins of the anterior and posterior common leaflets was performed in 3 children with quadricuspid common AV valve and effectively reduced the regurgitation. The semicircular annuloplasty with a thin Gore-tex graft or the suturing-up of floppy leaflets combined with plasty of the chordae and papillary muscle was carried out in two patients having tricuspid AV valve, and a favourable result was obtained in the semicircular annuloplasty. In mitral AV valvular regurgitation, two patients received the suturing-up of free margins of prolapsed leaflets, and the results were satisfactory. From these results we consider that the semicircular annuloplasty for dilated tricuspid AV valve and the suturing-up of free margins of dilated or floppy leaflets in quadricuspid and bicuspid AV valves are the recommendable procedures. If more than mild AV valvular regurgitation remains after these valvuloplasties, the Kay and/or DeVega annuloplasties should be added for eliminating the regurgitation.

Adolescent↗
PubMed1994

Turn-over of PAF in cultures of human paranasal sinus mucosa.

The change of PAF concentration in the culture medium was investigated by radioimmunoassay when 10(-8) M PAF or 10(-8) M lyso-PAF was incubated with a piece of normal human paranasal sinus mucosa. The PAF concentration in the medium of the former group was halved within 11.3 min and reduced to less than 5% of the initial concentration within 60 min. However, there was no significant difference in the reduction of PAF concentrations in the medium between groups with or without the mucosa. When 10(-8) M lyso-PAF was incubated with a piece of mucosa, PAF gradually increased and reached the maximum of 0.36 x 10(-8) M at 20 min, and thereafter quickly decreased to a non-detectable level.

Cells, Cultured↗
PubMed1994

Defecation mechanisms in conscious dogs after total colectomy with ileorectal anastomosis.

To clarify defection mechanisms in those with total colectomy, we performed comparative studies of intestinal motility in two groups of straight and J-pouch ileorectal anastomosis. In the straight group, 98 percent of the interdigestive migrating contractions (IMC) reached the anastomosis and 48 percent of the defecations were affected by the contractions. In the J-pouch group, 16 percent of the contractions reached the anastomosis and only 8 percent of the defecations were related to the contractions. We conclude that transmission of IMC to the rectum is related to the frequency of defecation after total colectomy and that the disappearance of IMC in the J-pouch anastomosis reduced the frequency of defecations in those instances.

Animals↗
PubMed1994

[A study of nosocomial infections by the comparison of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa].

The objective of this study was to investigate nosocomial infections by the comparison of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. We made a serological classification of 262 strains of Pseudomonas aeruginosa between 1983 and 1991. Group E strains were prevalent in 1987 and group F strains after 1990. Both these groups strains were resistant to several antibiotics, and were scarcely detected from the appendix contents in appendicitis that originated outside the hospital. Therefore we presumed these were nosocomial pathogens. With the countermeasures to nosocomial infections from 1987 on the isolation rate of enterotoxin type B and C MRSA strains decreased. Following this MRSA change, almost group E strains disappeared in Pseudomonas aeruginosa. Whereas type AC MRSA began to isolated abruptly from 1990, and the isolation of group F strains increased simultaneously. Type B and C strains still remained high sensitivity to minocycline. Type AC which have already gotten resistance to minocycline took the place of type B and C and prevalented. Similarly group F in Pseudomonas aeruginosa took the place of group E as soon as the former acquired resistance to carbapenem.

Cross Infection↗
PubMed1994

[Two cases of coronary artery fistula with coronary artery aneurysm].

Two cases of coronary artery fistula with coronary artery aneurysm were reported. Coronary angiography showed dilated right coronary artery with the formation of aneurysm drained to the right atrium and to the right ventricle respectively. The inflow ostium from the coronary artery to the aneurysm were closed from inside adding aneurysmorraphy. Postoperative clinical courses were uneventful and residual shunts were not detected by angiography. We reported these cases with literature.

Child, Preschool↗
PubMed1994

[DNA heterogeneity in oral cavity and hypopharyngeal carcinoma].

The study was carried out on 18 cases of oral cavity carcinoma and 12 cases of hypopharyngeal carcinoma to assess the degree of intratumoral heterogeneity and the relation to tumor size, lymph metastasis and histological type. In oral cavity carcinoma, 6 cases (33%) were aneuploid, while in hypopharyngeal carcinoma all were aneuploid. DNA heterogeneity was identified in 4 cases (22%) in oral cavity carcinoma, end in 6 cases (50%) of hypopharyngeal carcinoma. No correlation was found between DNA heterogeneity and tumor size, lymph metastasis and histological type. However, even early carcinomas have intratumoral DNA heterogeneity. It was supposed that the result which hypopharyngeal carcinoma had higher degree of aneuploid and DNA heterogeneity comparing with oral cavity carcinoma supported that hypopharyngeal carcinoma had higher clinical malignancy from the aspect of proliferative movement. The data indicate that it is impossible to analyze correct DNA content by only one specimen and it is important to investigate intratumoral DNA heterogeneity to research the mechanism of multiplicity and clinical malignancy of carcinoma.

Adult↗
PubMed1994

[Transcatheter embolization of aorto-pulmonary collateral arteries in cyanotic congenital heart disease].

Transcatheter embolization (TE) using steel coils was performed on three patients with aorto-pulmonary collateral arteries (APCAs). Case #1: In a 13-year-old boy who had undergone corrective surgery for pulmonary atresia with ventricular septal defect (PA with VSD), one APCA was embolized by the TE technique. This resulted in a remarkable improvement in postoperative pulmonary congestion. Case #2: A 13-year-old boy who had previously undergone procedures to correct tetralogy of Fallot (TOF), underwent TE for two APCAs prior to subsequent surgery before for pulmonary stenosis. The procedure abandoned one APCA because of the long narrow origin of the vessel. For the other APCA, TE was unsuccessfully performed due to the displacement of a coil into the peripheral pulmonary artery. Case #3: An 8-year-old girl with PA with VSD underwent TE for three APCAs before corrective surgery. One APCA arising from the abdominal aorta was occluded successfully. The other two were considered too small at the orifice for TE, and were ligated surgically before corrective surgery. TE is a safe and effective method for suitable cases of APCAs. However, caution should be exercised to prevent complications. The selection of appropriate coils and catheters is also important.

Adolescent↗
PubMed1994

DNA aberrations at the retinoblastoma gene locus in human squamous cell carcinomas of the lung.

We detected DNA aberrations at the RB locus in surgical specimens of human primary non-small cell lung carcinoma by single-strand conformation polymorphism analysis of polymerase chain reaction products amplified from regions of exons 2 to 27 including parts of the flanking intron sequences. Detection of nucleotide sequence polymorphism revealed loss of heterozygosity in six of eight informative cases among 13 squamous cell carcinomas analysed. In two of the six cases, mutations in the remaining allele were detected. In 25 adenocarcinomas analysed, no loss of heterozygosity was observed in 16 informative cases and a point mutation was detected in one of the uninformative cases. In one of three adenosquamous carcinomas analysed, a point mutation was detected and one adenoid cystic carcinoma analysed showed allelic loss of the RB gene. Our results indicated that loss of heterozygosity at the RB locus is frequent in squamous cell carcinomas of the lung, but not in adenocarcinomas. In the squamous cell carcinomas with allelic loss, mutations of the RB gene in the remaining alleles were found in one third of the tumors.

Base Sequence↗
PubMed1994

[Right-sided infective endocarditis with ventricular septal defect].

Two patients underwent surgical treatment for right-sided infective endocarditis with ventricular septal defect. In both cases, blood cultures showed Peptostreptococcus, and the operation was performed at non-active phase after antibiotics therapy. The case 1 was a 7-year-old girl who was observed a vegetation on the chorda of the anterior paillary muscle by echocardiography. The defect was directly closed and the vegetation was excised. The case 2 was 22-year-old female who had been diagnosed of VSD in her infancy. A high fever continued and echocardiography revealed a vegetation attached to the septal tricuspid leaflet. Partial excision of the leaflet and autopericard patch plasty was performed, and the VSD was directly closed. Postoperatively intravenous antibiotic therapy was given for periods of 6 weeks, and clinical course were uneventful in both cases. Local excision of vegetation and leaflet repair by autopericard patch plasty should be performed in cases with localized vegetation and minor valvular regurgitation.

Adult↗
PubMed1993

Involvement of the proteasome and antizyme in ornithine decarboxylase degradation by a reticulocyte lysate.

Ornithine decarboxylase (ODC) degradation in a freshly prepared reticulocyte lysate was examined. Immunodepletion of proteasomes from the reticulocyte lysate resulted in almost complete loss of ODC degradation. In contrast with the previously reported degradation in extracts of hepatoma tissue-culture (HTC) and Chinese-hamster ovary (CHO) cells or that by the purified 26 S proteasome, efficient degradation of ODC was observed in the lysate without exogenous antizyme, an ODC protein inhibitor induced by polyamines, owing to the presence of a significant amount of antizyme in the lysate. The degradation of ODC in the lysate was strongly suppressed on inactivation of antizyme in the lysate with antizyme inhibitor, a protein which binds to the antizyme and releases ODC from the ODC-antizyme complex. Thus the main pathway for ODC degradation in a reticulocyte lysate was essentially the same as that characterized previously in extracts of HTC and CHO cells, namely an ATP- and antizyme-dependent 26 S proteasome-catalysed pathway that is presumed to be responsible for ODC degradation in whole cells.

Animals↗
PubMed1993

Single amino-acid replacement is responsible for the stabilization of ornithine decarboxylase in HMOA cells.

The half-life of ornithine decarboxylase (ODC) in HMOA cells, a variant cell line derived from hepatoma tissue culture (HTC) cells, is markedly increased compared with that in the parental cell line. In the present study, we examined which of the three relevant factors is responsible for the ODC stabilization in HMOA cells, namely ODC itself, a regulatory protein antizyme and an ODC-degrading activity. SDS/PAGE analysis of radiolabeled ODC revealed that ODC from HMOA cells migrated somewhat faster than that from HTC cells, suggesting that HMOA ODC was structurally altered. Direct sequencing of reverse-transcription/polymerase-chain-reaction (RT-PCR) products of ODC mRNA from HMOA cells revealed a T to G replacement, causing a Cys441-->Trp replacement near the C-terminus. No alteration was found in the whole coding region of antizyme mRNA. An authentic mutant ODC cDNA with the same replacement was transfected and expressed in C55.7 ODC-deficient Chinese hamster ovary cells. Upon cycloheximide treatment, the mutant ODC activity did not decrease appreciably for at least 3 h, whereas wild-type ODC activity decreased with a half-life of 1 h. In-vitro-synthesized mutant ODC with the Cys441-->Trp (or Ala) replacement was also stable in a reticulocyte-lysate ODC-degradation system. Metabolically labeled and purified mouse ODC was degraded in HMOA cell extracts in the presence of ATP and antizyme as rapidly as in HTC cell extracts, indicating that HMOA cells have a normal ODC degrading activity. These results indicated that the single amino acid replacement, Cys441-->Trp, is responsible for the stabilization of ODC in HMOA cells and that Cys441 is important for rapid ODC turnover.

Animals↗
PubMed1993

Functional interactions between SV40 T antigen and other replication proteins at the replication fork.

The functional interaction of simian virus 40 (SV40) large tumor antigen (T antigen) with DNA polymerase alpha (pol alpha)-primase complex, human single-stranded DNA binding protein (HSSB), and DNA polymerase delta (pol delta) holoenzyme, which includes pol delta, activator I (also called replication factor C), and proliferating cell nuclear antigen, at the replication fork was examined using the purified components that support SV40 DNA replication. Dilution of reaction mixtures during RNA primer synthesis revealed that T antigen remained associated continuously with the fork, while the pol alpha-primase complex dissociated from the complex during oligoribonucleotide synthesis. T antigen unwound duplex DNA from the SV40 core origin at a rate of 200 base pairs/min. Pol alpha-primase complex inhibited the rate of the unwinding reaction, and HSSB, pol alpha, and primase were all required for this effect. These requirements are the same as those essential for DNA primase-catalyzed oligoribonucleotide synthesis (Matsumoto, T., Eki, T., and Hurwitz, J. (1990) Proc. Natl. Acad. Sci. U. S. A. 87, 9712-9716). This result suggests that the pol alpha-primase complex interacts with T antigen and HSSB during the unwinding reaction to synthesize RNA primers and that the interaction decreases the rate of T antigen movement. While pol delta holoenzyme can elongate primed DNA chains at a rate of 400-600 nucleotides/min on singly primed phi X174 DNA, the rate of the leading strand synthesis catalyzed by pol delta holoenzyme in the SV40 replication system in vitro was about 200 nucleotides/min. This rate was similar to the unwinding rate catalyzed by T antigen. Thus, the rate of leading strand synthesis catalyzed by pol delta holoenzyme in vitro appears to be limited by the unwinding reaction catalyzed by T antigen.

Antigens, Polyomavirus Transforming↗
PubMed1993

DNA polymerase alpha stimulates the ATP-dependent binding of simian virus tumor T antigen to the SV40 origin of replication.

The ATP-dependent binding of simian virus 40 (SV40) large tumor antigen (T antigen) to the SV40 origin of replication is an essential step in the initiation of SV40 DNA synthesis. Previous studies indicated that the ATP-dependent complex consists of a double hexamer of T antigen at the origin. The binding reaction and the subsequent unwinding of the duplex DNA from the origin were examined using a gel mobility shift assay. T antigen bound to the core origin cooperatively in the presence of ATP. In the presence of human single-stranded DNA-binding protein (HSSB), T antigen, complexed to the core origin, started the unwinding of duplex DNA. At low concentrations of T antigen and in the presence of ATP, DNA polymerase alpha (pol alpha) stimulated the binding of T antigen to the core origin, while HSSB did not. This stimulation resulted in an increase in the subsequent unwinding reaction in the presence of HSSB. Primase alone did not affect the binding reaction and was not required for the stimulation by pol alpha. The stimulation required the hydrolysis of ATP and the AT tract domain of the core origin. Kinetic studies showed that while pol alpha stimulated the binding of T antigen to the core origin, it did not stabilize the complex. Pol alpha also stimulated the formation of the ATP-dependent T antigen-site I complex, a region that also contains an AT-rich sequence. These observations imply a regulatory role for pol alpha in the initiation of SV40 DNA replication.

Adenosine Triphosphate↗