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E Matsuo

Publications and source records attributed to E Matsuo.

At least 19 recordsLinked to original sources
PubMed2000

Holding characteristics of planar objects suspended by near-field acoustic levitation

The authors have found the acoustic levitation phenomenon where planar objects of 10 kg weight can be levitated near a vibration surface. This phenomenon has been studied for non-contact transportation. A circular planar object can be suspended without contacting a circular vibration plate. We have studied the holding force which acts horizontally on the levitated objects. The horizontal position of the object is stabilized by this force. In this paper, we discuss the effect of the radius of a levitated object, levitation distance, displacement amplitude of the vibration plate and the vibration mode on the suspending force.

Journal Article↗
PubMed1999

The plasmid F OmpP protease, a homologue of OmpT, as a potential obstacle to E. coli-based protein production.

OmpT, an outer membrane-localized protease of Escherichia coli, cleaves a number of exogenous and endogenous proteins during their purification. SecY, an endogenous membrane protein, is a target of this artificial proteolysis in vitro. Here we report that SecY cleavage occurs even in cell extracts from ompT-disrupted cells, if they carry an F plasmid derivative. A gene, ompP, on the F plasmid was shown to be responsible for this proteolysis. These results indicate that the absence of an F-like plasmid should be checked when choosing a host strain for E. coli-based protein production.

Bacterial Outer Membrane Proteins↗
PubMed1999

Conservation of histone binding and transcriptional repressor functions in a Schizosaccharomyces pombe Tup1p homolog.

The Ssn6p-Tup1p corepressor complex is important to the regulation of several diverse genes in Saccharomyces cerevisiae and serves as a model for corepressor functions. To investigate the evolutionary conservation of these functions, sequences homologous to the S. cerevisiae TUP1 gene were cloned from Kluyveromyces lactis (TUP1) and Schizosaccharomyces pombe (tup11(+)). Interestingly, while the K. lactis TUP1 gene complemented an S. cerevisiae tup1 null mutation, the S. pombe tup11(+) gene did not, even when expressed under the control of the S. cerevisiae TUP1 promoter. However, an S. pombe Tup11p-LexA fusion protein repressed transcription of a corresponding reporter gene, indicating that this Tup1p homolog has intrinsic repressor activity. Moreover, a chimeric protein containing the amino-terminal Ssn6p-binding domain of S. cerevisiae Tup1p and 544 amino acids from the C-terminal region of S. pombe Tup11p complemented the S. cerevisiae tup1 mutation. The failure of native S. pombe Tup11p to complement loss of Tup1p functions in S. cerevisiae corresponds to an inability to bind to S. cerevisiae Ssn6p in vitro. Disruption of tup11(+) in combination with a disruption of tup12(+), another TUP1 homolog gene in S. pombe, causes a defect in glucose repression of fbp1(+), suggesting that S. pombe Tup1p homologs function as repressors in S. pombe. Furthermore, Tup11p binds specifically to histones H3 and H4 in vitro, indicating that both the repression and histone binding functions of Tup1p-related proteins are conserved across species.

Amino Acid Sequence↗
PubMed1999

Complete DNA sequence analysis for 16S ribosomal RNA gene of the leproma-derived, cultivable and nerve-invading mycobacterium HI-75.

The complete 1493 nucleotide sequence of the 16SrRNA gene of the leproma-derived and cultivable mycobacterium HI-75 strain was analyzed to elucidate the taxonomic characteristics by direct sequencing of the polymerase chain reaction (PCR) products. The results revealed that the sequence of mycobacterium HI-75 was mostly similar to that of Mycobacterium scrofulaceum with 5 bases differences in the sequenced 1493 bases (0.35%) of the 16SrRNA gene. M. leprae differed from the strain with 47 bases (3.3%). Sasaki and Hamit reported the nerve-invasive activity of the inoculated mycobacterium HI-75 in nude mice or the 131I-treated immunocompromised Swiss mice. The results indicate that mycobacterium HI-75 could be a mutant of M. scrofulaceum possessing the ability to invade the peripheral nerve in addition to developing leproma-like lesions.

Base Sequence↗
PubMed1998

Syd, a SecY-interacting protein, excludes SecA from the SecYE complex with an altered SecY24 subunit.

Syd is an Escherichia coli cytosolic protein that interacts with SecY. Overproduction of this protein causes a number of protein translocation-related phenotypes, including the strong toxicity against the secY24 mutant cells. Previously, this mutation was shown to impair the interaction between SecY and SecE, the two fundamental subunits of the membrane-embedded part of protein translocase. We have now studied in vitro the mechanisms of the Syd-directed inhibition of protein translocation. Pro-OmpA translocation into inverted membrane vesicles (IMVs) prepared from the secY24 mutant cells as well as the accompanied translocation ATPase activity of SecA were rapidly inhibited by purified Syd protein. In the course of protein translocation, high affinity binding of preprotein-bearing SecA to the translocase on the IMV is followed by ATP-driven insertion of the 30-kDa SecA segment into the membrane. Our experiments using 125I-labeled SecA and the secY24 mutant IMV showed that Syd abolished both the high affinity SecA binding and the SecA insertion. Syd was even able to release the inserted form of SecA that had been stabilized by a nonhydrolyzable ATP analog. Syd affected markedly the proteolytic digestion pattern of the IMV-integrated SecY24 protein, suggesting that Syd exerts its inhibitory effect by interacting directly with the SecY24 protein. In accordance with this notion, a SecY24 variant with a second site mutation (secY249) resisted the Syd action both in vivo and in vitro. Thus, Syd acts against the SecY24 form of translocase, in which SecY-SecE interaction has been compromised, to exclude the SecA motor protein from the SecYE channel complex.

Adenosine Triphosphatases↗
PubMed1998

Genetic analysis of an essential cytoplasmic domain of Escherichia coli SecY based on resistance to Syd, a SecY-interacting protein.

We previously described a dominant negative secY-d1 allele in Escherichia coli, whose product interferes with protein export, presumably by sequestering SecE, the stabilizing partner of SecY. Syd is the product of a multicopy suppressor of the secY-d1 phenotype, and its overproduction preferentially stabilizes the wild-type SecY protein. In contrast, overproduction of Syd is toxic to the secY24 mutant, which shows a partial defect in SecY-SecE interaction. We isolated Syd-resistant revertants from the secY24 mutant. Pseudo-reversions mapped to sites at or near the secY24 mutation site (Gly240-->Asp). The secY249 mutation (Ala249-->Val) intragenically suppressed Syd sensitivity, but not the temperature-sensitive Sec phenotype of the secY24 mutation. The SecY249 mutant protein shows a reduced capacity to be stabilized by Syd, suggesting that the mutation weakens the SecY-Syd interaction. The other two mutations changed residue 240 (the site of the secY24 alteration) to Asn (secY245) or Ala (secY241) and restored the ability of the cell to export protein. Although the secY245 mutant retained some sensitivity to Syd overproduction, the secY241 mutant was completely Syd-resistant. Furthermore, the secY241 mutation seemed to represent a "hyper reversion" with respect to the SecY-SecE interaction. Protein export in this mutant was no longer sensitive to SecY-d1. When the secY-d1 mutation was combined intragenically with secY241, the resulting double mutant gene (secY-d1-241) showed an increased ability to interfere with protein export. On the basis of our model for SecY-d1, these results suggest that the secY241 alteration enhances SecY-SecE interaction. These results indicate that residue 240 of SecY is crucial for the interaction between the cytosolic domains of SecY and SecE required for the establishment of the translocase complex.

ATP-Binding Cassette Transporters↗
PubMed1998

[A case of ovarian cyst presenting as urinary retention].

A 54-year-old woman presented with repeated episodes of urinary retention during an approximately 7-month period of dysuria. Computerized tomography scan revealed a right ovarian cyst and a small uterine myoma. At operation, the ovarian cyst was deeply incarcerated into the pouch of Douglas displacing the bladder neck and the uterine cervix in the anterocephalad direction. Histological diagnosis of the resected cyst was benign mucinous cystadenoma. This is the 5th reported case of urinary retention caused by ovarian cyst in the Japanese literature.

Cystadenocarcinoma, Mucinous↗
PubMed1997

[Hansen's disease and nephropathy as its sequence].

Nephropathy as the sequences of Hansen's disease before and after the introduction of chemotherapy was compared referring to the report by Hayashi in 1943 and the summary of the autopsy reports from 1978 to 1981 at National Hansen's disease hospital Zenseien. Unlike the high rates of tuberculosis as the cause of death before the introduction of chemotherapy (41.3%) those thereafter decreased to be negligible. On the other hand the comparison of the rates of nephropathy with the same way as that of tuberculosis was impossible since the description about nephropathy by Hayashi was not sufficient to characterize each nephropathy since he included arteriolitis, glomerulonephritis and interstitial nephritis together in the term of nephritis. Death rate due to nephritis among Hansen's disease patients according to Hayashi at that time was 21.2% which was twice as many comparing to that in the other cases. According to the report about the cases of Zenseien those reported to have glomerulonephritis was 37.3% though those were not necessarily listed as the cause of death. Also the nephropathy including fibrinoid angitis with occasional microaneurysmal dilatation of afferent arteries, glomerulitis, sclerosis and stricture of efferent arteries likewise ischemic acute tubular necrosis possibly as the result of these angiopathy seemed to be present. These vascular changes partially resemble to that of microscopic periarteritis nodosa but seems to be common in the smaller arteries. In conclusion, unlike the case of tuberculosis the rate of nephritis including glomerulitis, arteriolitis and interstitial nephritis as Hayashi used as his criteria does not seem to have decreased. Therefore, the critical analysis of the nephropathy especially of that relating to the arteriolitis should be done to obtain the knowledge to suppress its occurrence.

Arteritis↗
PubMed1997

A genomic study on the cultivable and nerve invading Mycobacterium HI-75 after the recovery 3 months of the inoculation to nude mice.

The sequence of the polymerase chain reaction (PCR) product of 16S ribosomal RNA (16S rRNA) of the leproma-derived and cultivable Mycobacterium HI-75 (M. HI-75) which was obtained from the infected regions of inoculated mice, was examined and compared with that of the cultured bacteria by the direct sequencing techniques. The sequence was completely consistent with the cultured bacilli in the comparable 837 bases of 16S rRNA. The mycobacterium examined in this study was originally isolated as M. leprae (ML) by Skinsnes, et al. in 1975 from leproma of a lepromatous type Hansen's disease patient and therefore named as Mycobacterium leprae HI-75 by them, and was maintained from 1984 using either Ogawa's or Sauton's media in the beginning and Ogawa's medium enriched with glucronic acid and N-acetyl-D-glucosamine recently. Sasaki and Hamit reported the nerve invasion and the growth of the inoculated bacilli either to the nude mice or the I131 treated immunocompromised Swiss mice. We previously reported that cultured HI-75 was most similar to M. scrofulaceum by the direct sequencing of the gene of 16S rRNA. The 16S rRNA obtained from the mouse tissue in the present study indicated that M. HI-75 would be a variant of M. scrofulaceum possessing an ability to invade into peripheral nerve. The results suggest that the HI-75 strain claims a nature as a pathogen to develop a leproma-like lesion.

Animals↗
PubMed1994

Hepatic encephalopathy with increased cerebral blood flow in SPECT and MRI abnormalities in the basal ganglia.

A case of hepatic encephalopathy with increased cerebral blood flow in single-photon emission computed tomography (SPECT) and abnormalities upon magnetic resonance imaging (MRI) is reported. SPECT showed increased blood flow exceeding 70 ml/100 g/min in the cerebellum, basal ganglia and cerebral cortex, with hyperammonemia and abnormal electroencephalographic signs showing severe generalized slowing. SPECT data and MRI might reflect abnormal metabolism and neuropathological changes in hepatic encephalopathy.

Antiparkinson Agents↗
PubMed1994

On the beta-glucuronidase binding protein (BGBP) of microorganisms. Its purification, the antiserum preparation against that and its localization in leproma and the other infectious lesions shown by immunohistologic method.

Our previous studies suggested that M. leprae (ML) grow in peripheral nerves and lepra cells because ML metabolize hyaluronic acid (HA), and use its component for their growth by the aid of host enzyme combined to the bacilli derived beta-glucuronidase binding protein (BGBP). In this study, therefore, we examined the method to purify BGBP from a mycobacterium HI-75 originally separated from a leproma and cultured by modified Ogawa's medium containing split products of HA (glucuronic acid and N-acetylglucosamine). The distribution of BGBP in leproma and the other lesions consisting of hepatitis B virus infected liver and M. avium-intracellulare infected lung tissue were also immunohistologically examined. As the result, the best method to get BGBP was preparatory electrophoresis in the final step of the purification and not the molecular sieving. The BGBP was actually proven in leproma and the other infected tissues as described, indicating the abilities of these microorganisms to utilize the metabolic machinery of the host with the similar ways to that of ML.

Animals↗
PubMed1990

[Brain metastasis from primary pericardial mesothelioma. Case report].

A 50-year-old female was admitted because of nausea, vomiting, and cerebellar ataxia. Computed tomography scan revealed an enhanced mass accompanied with a cyst in the right cerebellar hemisphere. The mass situated in the subcortical region was removed. Histologically, highly vascular tumor cells lined the cavities. Postoperative radio- and chemotherapy were administered and the clinical symptoms improved gradually. Two months later, the patient complained of dyspnea. Chest X-ray on second admission demonstrated cardiomegaly. Hemorrhagic pericardial effusion amounting to 1000 ml was aspirated by pericardial puncture. Papillary clusters of tumor cells were demonstrated in the pericardial effusion. The patient died of cardiac failure. At necropsy solid tumors were located in the heart, lung, left inguinal region, and cerebellum. Histological diagnosis was mesothelioma arising from the heart. Primary pericardial mesotheliomas are rare; approximately 106 cases have been reported. Pericardial mesothelioma frequently spreads to the adjacent pleura and mediastinum, but distant metastases are extremely rare because patients with pericardial mesothelioma tend to die early due to cardiac failure or cardiac tamponade.

Brain Neoplasms↗
PubMed1990

A study on the impression materials using for the mannequin practice.

The mannequin exercises which are practiced in clinical exercises of dental colleges are getting more important these days. It is necessary to compare the difference between the efficiency of a mannequin and a living body. When making a partial denture using the simulation model, it is very important to know what kind of impression materials you are able to use or the accuracy of those impression materials. A study on a simulation model is used for making a partial denture. Choosing some sort of impression materials and treatment positions have the possibility to exert influence on impression taking through the process from impression taking to model making. At first, to find the impression materials which are able to take the impression of simulation model's simulate mucous membrane, choose nine impression materials and examined them. Then, examine the effective relationship between the impression taking and the mannequin's head and back position. Establish a mannequin's head and back inclination from four positions. Cut the acquired four models at the same location and examine them. The following results were obtained. 1. Of the impression materials used, with the exception of Flexicon and Rapid, there was no adhesiveness observed with the artificial mucosa. In addition, in the case of Exaflex Injection, Regular and Putty, there were noninduration sections among the sections that contacted with the artificial mucosa. 2. Regarding the effect of the bodily position, changes in the impression were observed for the upper jaw in the case of the median sagittal section C and the lateral section S. This was particularly frequent on the palate in the molar region.(ABSTRACT TRUNCATED AT 250 WORDS)

Dental Impression Materials↗
PubMed1990

[A study of linearity and reciprocity during shock applied with a hammer to human dry skull].

The authors used a human dry skull on which the cranial bone mandible had been joined with an artificial articulator disk to form a single unit. Impact acceleration corresponding to weak and strong tapping was considered a dynamic load in examining the vibration transfer characteristics of the facial cranial bone when impact was applied from the mentum section in a situation designed to be closer to reality. Flexion injection type (resonance frequency f0 = 100 to 150 Hz, produced by GC Corp.) was applied to the human dry skull as an artificial periodontal membrane at thickness of 0.3 mm. In addition, Exaflex heavy body type (f0 = 400 Hz, produced by GC Corp.) was applied as an artificial disk. This was then placed on a damper produced by spreading a rubber dam sheet with a thickness of 35 microns on a tire tube with a diameter of 35 cm and an air pressure of 35 kg/cm2. Investigations were then made concerning linearity and reciprocity to determine whether an experimental system could be achieved or not. This was then followed by modal analysis. As a result, the following matters were ascertained: (1) The resonating area differed according to the extent of the force. (2) An increase in the viscoelastic elements of the silicon was accompanied by attenuation of force. (3) Directionality of force attenuation was caused by the complexity of bone structure. (4) A tapping force of 0.3G or 1G was sufficiently attenuated by the facial cranial bone. (5) The transfer function at the bone seams and thinner areas of the bones was insufficient for modal analysis of the facial region and total cranial bone of the human dry skull.

Biomechanical Phenomena↗