Biomedical subjects
Publications and source records attributed to Y Okazaki.
"In this paper, the author presents his idea on the concept of population policy, emphasizing the importance of indirect measures. As an example the child allowance system in Japan is explained and evaluated by comparing [it] with those in Western countries." (SUMMARY IN ENG)
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Two cases of postinfarction oozing type left ventricular rupture and a case of oozing type left ventricular rupture due to catheter perforation for left ventriculography are reported. The technique used to repair the rupture is fibrin glue-oxycellulose fixation method. The post operative course of three cases were uneventful. But left ventricular aneurysm remained in two cases.
UNLABELLED: To better understand cortical perfusion, we developed a method for a three-dimensional display technique with 99mTc-hexamethylpropyleneamine oxime (HMPAO) SPECT. METHODS: Twelve patients with higher cortical dysfunction due to Alzheimer's disease and 18 age-matched controls were examined. Data acquisition was performed after intravenous injection of 740 MBq of 99mTc-HMPAO. After reconstructing the transaxial images, the three-dimensional images were obtained by modified volume rendering, where the surfaces were displayed in the corresponding colors as the maximum cortical value within a depth of 2 cm. RESULTS: In the control studies, almost all surface cortices were over 60% of the maximum cerebellar value. In Alzheimer's disease patients, areas of perfusion below 60% were detected in the temporo-parietal lesions and frontal lobe lesions in 6 of 12. These findings correlated with the neurological dysfunction. CONCLUSION: This method provides realistic three-dimensional information about surface cortical perfusion, which was found to be useful in clinical investigations of higher cortical dysfunction due to degenerative or cerebrovascular diseases.
Ideally, in preoperative intra-arterial infusion chemotherapy (regarding advanced breast cancer) is to obtain the most significant effects concerning histological features. Intra-arterial infusion chemotherapy using epirubicin (EPI), used in conjunction with daily doses of 1,200 mg medroxyprogesterone acetate (MPA), have recently been performed. This procedure has shown remarkable histological effects in the metastatic lymph nodes as well as in the primary lesions. These results were especially remarkable in the patients who were administered MPA (daily) two weeks prior to EPI infusion. These patients showed a complete disappearance of tumor cells. The results were interesting in view of the mechanism of action. Intra-arterial infusion chemotherapy combined with MPA may also be valuable in treating metastatic liver tumors and recurrent lesions in the regional lymph nodes such as supraclavicular tumors. A high response rate was obtained in the chemo-endocrine therapy when combined with MPA as a pretreatment. Thus, MPA may be expected to be available as a systemic therapy, too. In the future, a new development in the field of intra-arterial infusion chemotherapy may be achieved by utilizing a combination of angiogenesis inhibitors and peripheral blood stem cell transplantation.
From March 1983 to September 1994, 53 consecutive patients underwent an emergency operation for type A acute aortic dissection. Eighteen patients before 1988 (Group I) underwent simple ascending aortic replacement (n = 13) and composite graft replacement (n = 5) by conventional method. Thirty-five patients after 1989 (Group II) underwent extended ascending aortic replacement (n = 17), hemiarch replacement (n = 6), total arch replacement (n = 8) and composite graft replacement (n = 4) using a brief period of circulatory arrest. The overall hospital mortality rate was 36.8% in Group I and 25.7% in Group II. The survivals after initial operation was 47% at 10 years (Kaplan-Meier) and the event free rate was 78% at ten years, respectively. Computed tomographic scanning and aortogram demonstrated the patent false lumen in 20 patients (64.5%) at the descending thoracic aorta. In conclusion, extended ascending aortic replacement is the useful operative technique to perform accurate resection of intimal disruption and clamp-site aorta because the replacement of the entry site could reduce the risk of operative mortality and reoperation. Total arch replacement is not necessarily required, if the entry is properly resected by extended ascending aortic replacement or hemiarch replacement. Close follow-up must be considered at the patients with patent false lumen, especially in patient with Marfan's syndrome.
We have developed an expanded system (RLGS Ver.1.8) for producing RLGS patterns that result in a 16-fold increase in the number of gels produced and a 10-fold reduction in the total cost per gel. The major modifications include: 1) performing the blocking and labeling step without phenol extraction or ethanol precipitation; 2) minimizing the reaction volume and the enzyme units in each step; 3) developing a long vertical agarose disc gel electrophoresis for the 1st-dimension; and 4) developing a new apparatus for multiplex vertical 2nd-dimensional electrophoresis. RLGS Ver.1.8 was used with a new combination of restriction enzymes to identify variation for 209 loci between C57BL/6J and DBA/2J. Twenty-six BXD RI strains were analyzed and 195/209 loci were genetically mapped. These loci were mapped in one week of laboratory work by two people. This system provides an important tool for the genetic analysis of new loci in similar genetic resources.
A high-speed, high-resolution teleradiology system with full duplexing based on the Shinshu University Video and Communication Network System (SUNS) using Giga-Herz microwaves is described. The LAN at Nagano Red-Cross Hospital and The Radiology Department of Shinshu University Hospital are interfaced to a personal computer with a laser film digitizer, interactive display, and network interface. The throughput per digitized high-resolution radiographic image was 65 sec, and the mean transmission rate was 805 kilobit per sec. Teleradiology conferencing is also possible with this system. Radiologists at both hospitals interactively observe the same high-resolution images on the CRT screen using mouse cursor synchronization.
Shinshu University consists of five campuses in different locations, a situation that presents some problems in communication. To solve this problem, the Shinshu University Video and Data Network System (SUNS), which includes a high-speed audio-visual transfer function, has been developed and utilized for pre- and postgraduate education, administrative teleconferences, and local telephone (PBX) and Fax services. In 1988, a cooperative group for the study of radiographic image processing was organized, consisting of staff members of Shinshu University Hospital in Matsumoto, the Faculty of Engineering in Nagano (75 km from Matsumoto) and the Faculty of Textile Science and Technology in Ueda (45 km from Matsumoto). The system has been developed with a pair of personal computer (PC)-based interactive image workstations and high-speed digital telecommunication interfaces to the SUNS. A transmission time of 878 kbps has been attained, including the time needed for read/write onto the PC hard disk. Image data thus transferred from the hospital have been utilized for the study of image processing by researchers in the Faculty of Engineering, and the processed images have been sent back to the hospital for evaluation of clinical efficacy of the processing by diagnostic radiologists. This kind of microwave network is a promising alternative for high-speed data transmission for radiological images and their processing.
The occurrence of many charge isoforms is known for rat liver fatty acid-binding protein, and this is the major cause of conflicting data on the characterization of the protein. Recently, M. Li and T. Ishibashi (1992, Arch. Biochem. Biophys. 298, 254-258) clearly demonstrated that some charge isoforms are due to bound fatty acids. We found that acidic fraction (DE-III) of rat liver fatty acid-binding protein contained isoaspartyl-105 protein resulted from deamidation and peptide rearrangement at Asn-105. Since DE-III fraction carries mainly arachidonate, this post-translational modification might modulate binding specificity of fatty acid-binding protein.
We developed a model by which the transvascular removal of unnecessary substances in brain edema fluid could be measured quantitatively and chronologically. Brain stab wounds were produced in Wistar rats by insertion of paired microdialysis probes in the unilateral caudatoputamen. Homovanillic acid (HVA) was administered by microdialysis from one probe, and the HVA clearance was measured by HPLC analysis of perfusate from the other probe. Using this model, we evaluated the site of removal and whether the removal processes were affected by anesthesia or an elevated plasma concentration of the substance. As a result, 1) Probenecid did not change HVA clearance although this inhibits HVA removal via subarachnoid vessels. Therefore, HVA removal in this model was considered mainly due to intraparenchymal transvascular efflux. 2) There was no alteration in HVA removal induced by anesthesia or intravenous HVA injection. Consequently, this efflux mechanism seems to be a rather stable protective process, and seems to play a considerable role in brain microenvironmental homeostasis.
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A new imprinted gene has been discovered in mice using the technique of restriction landmark genomic scanning (RLGS) with methylation sensitive enzymes. Eight out of 3,100 strain-specific NotI and BssHII spots were identified as imprinted in reciprocal F1 hybrids. Subsequently, we isolated a genomic clone for one locus on proximal chromosome 11 near the Glns locus, an imprinted region in uniparental disomic mice, and its corresponding cDNA clone. Expression of this transcript from the paternal allele was established using RT-PCR of reciprocal F1-hybrid mice. The amino-acid sequence deduced from the cDNA showed significant homology to the U2 small nuclear ribonucleoprotein auxiliary factor 35 kDa subunit.
The authors studied the role of 70-Kd heat shock protein (HSP70) in the progression of breast cancer by examining the correlation between the expression of HSP70 and epidermal growth factor receptor, c-erbB-2, p53, and estrogen receptor in 124 cases of invasive primary human breast cancers. Positivity of an anti-HSP70 monoclonal antibody, C92, was closely associated with the elevation of estrogen receptor (P < .008), whereas it inversely correlated with the expression of p53 (P < .01). In addition, the expression of HSP70 correlated inversely with the expression of epidermal growth factor receptor, although the correlation was not statistically significant (P = .06). These results suggest that the expression of HSP70 plays a role in the progression of human breast cancer.
We developed a method for producing restriction landmark genomic scanning (RLGS) profiles of large-size genomes, such as those of higher plants or amphibians using a restriction trapper. Use of the conventional RLGS method is limited to genomes smaller than 3 x 10(9) bp, because the larger genomic DNAs, especially those of more than 1 x 10(10) bp, produce high background due to incorporation of radioactivity at non-specifically damaged sites. Our new method reduces the background levels by reducing genome complexity to 1/200-1/300 using a purification step to enrich DNA fragments carrying specific restriction landmarks at their ends using a restriction trapper. This step makes it possible to obtain RLGS patterns of larger genomes. Our paper describes the practical application for the RLGS method using a restriction trapper with the pine tree genome (3 x 10(10) bp/haploid genome; Pinus koraiensis Sieb. et Zucc.) as an example.
We have developed a multiplex method of genome analysis, restriction landmark genomic scanning (RLGS) that has been used to construct genetic maps in mice. Restriction landmarks are end-labeled restriction fragments of genomic DNA that are separated by using high resolution, two-dimensional gel electrophoresis identifying as many as two thousand landmark loci in a single gel. Variation for several hundred of these loci has been identified between laboratory strains and between these strains and Mus spretus. The segregation of more than 1100 RLGS loci has been analyzed in recombinant inbred (RI) strains and in two separate interspecific genetic crosses. Genetic maps have been derived that link 1045 RLGS loci to reference loci on all of the autosomes and the X chromosome of the mouse genome. The RLGS method can be applied to genome analysis in many different organisms to identify genomic loci because it uses end-labeling of restriction landmarks rather than probe hybridization. Different combinations of restriction enzymes yield different sets of RLGS loci providing expanded power for genetic mapping.
The in vivo antichlamydial activities of sparfloxacin and reference drugs were examined in a experimental model of pneumonia caused by Chlamydia pneumoniae in leukopenic mice; their in vitro activities were also examined. The most potent agents in vitro were sparfloxacin (MICs for C. pneumoniae Kajaani and IOL 207, (0.031 and 0.031 micrograms/ml, respectively), clarithromycin (0.031 and 0.031 micrograms/ml, respectively), and minocycline (0.031 and 0.031 micrograms/ml, respectively); these were followed by tosufloxacin (0.063 and 0.125 micrograms/ml, respectively) and ofloxacin (0.5 and 0.5 micrograms/ml, respectively). The MBCs of sparfloxacin, tosufloxacin, ofloxacin, clarithromycin, and minocycline for these two strains were 0.063 and 0.063 micrograms/ml, 0.125 and 0.25 micrograms/ml, 1.0 and 1.0 micrograms/ml, 0.125 and 0.125 micrograms/ml, and 0.25 and 0.25 micrograms/ml, respectively. Fatal pneumonia was induced by intranasal inoculation of cyclophosphamide-treated leukopenic mice with C. pneumoniae IOL 207; infiltration of neutrophils and lymphocytes was observed in the lungs of these mice by histopathological examination. The 50% effective dose of sparfloxacin (oral dose of 0.97 mg/kg of body weight) against the pneumonia was the lowest among the drugs tested; this was followed by those of minocycline (2.22 mg/kg), tosufloxacin (3.47 mg/kg), clarithromycin (4.66 mg/kg), and ofloxacin (16.6 mg/kg). The results indicate that it may be worthwhile to use sparfloxacin against C. pneumoniae infections in humans.