Search PubMed⌕ Search

Biomedical subjects

E Yamamoto

Publications and source records attributed to E Yamamoto.

At least 145 records · Page 8Linked to original sources
PubMed1993

[Computerized database system for pure tone audiometry].

The management and storage of pure tone audiometry data creates a major problem for otolaryngological clinics. We have devised a new computerized database system to overcome this problem. The hardware involved includes multiple audiometers and computers interfaced with a glassfiber local area network (Pi-Net). The software used is database 3 plus, a popular database language and utility software package. Programs were written for data entry, data transfer, reference, entry of patient ID, and evaluation of tympanoplasty. The following benefits of the system are noted. 1) Data entry is possible at every terminal (audiometer and computer). 2) Storage capacity is sufficient for more than 10 years of operation. 3) All data can be retrieved rapidly at any terminal. Evaluations of pre- and post-tympanoplasty hearing loss are facilitated by this system. This system is very effective for follow up of hearing disorders.

Audiometry, Pure-Tone↗
PubMed1992

A simple and sensitive ELISA of antibodies to pertussis antigens.

A precise method for quantifying serum antibody levels to antigens of Bordetella pertussis is required to evaluate pertussis vaccines, to diagnose pertussis infections, and to detect transplacentally transmitted maternal antibodies. The purpose of this paper is to report a rapid, sensitive, easy and standardized ELISA method using polystyrene balls for the assay of serum antibodies against pertussis toxin (PT) and filamentous haemagglutinin (FHA), which are protective antigens of B. pertussis. By the polystyrene ball method, a clear-cut difference was observed between values of pre- and postvaccination serum samples while by the conventional plate method those values overlapped. It was concluded that the PS ball method is one of the most sensitive and simple methods for detecting antibodies against PT and FHA.

Adhesins, Bacterial↗
PubMed1992

Investigation of the external aperture of the vestibular aqueduct in Menière's disease by three-dimensional image analysis.

The width of the external aperture of the vestibular aqueduct was measured in patients with Meniere's disease using three-dimensional images. The width of the aperture on the affected side was significantly smaller compared with that in normal ears or ears with chronic otitis media. Also, the width of the aperture on the opposite (healthy) side in unilateral Meniere's disease was significantly smaller than in these two other groups. These findings suggest that the aqueduct is incompletely developed in patients with Meniere's disease and that this may be related to the pathogenesis of this condition. Also, in unilateral Meniere's disease the opposite ear runs a high risk of eventually developing the disease.

Adolescent↗
PubMed1992

[A case of recurrent esophageal cancer maintaining complete long-term response after 5'-DFUR and ftorafur administrations].

The authors report a case with esophageal cancer who had undergone a non-curative resection and showed a recurrence. Treatment with only oral 5'-DFUR resulted in complete response. This was followed by oral ftorafur, and the case has remained complete response for 40 months. It is rare to obtain such an effect in esophageal cancers by oral and sole administration of a drug in the 5-FU class. Our experience with this case is described.

Administration, Oral↗
PubMed1991

Lignin peroxidase: toward a clarification of its role in vivo.

The extracellular lignin peroxidase from the white-rot basidiomycete Phanerochaete chrysosporium is thought to play an important role in lignin biodegradation. However, the majority of lignin-derived preparations actually experience overall polymerization at the hands of the enzyme in vitro. It has now been found that, in the presence of H2O2 at pH 4.0, the monomeric lignin precursor coniferyl alcohol is polymerized quantitatively by a lignin peroxidase preparation which is uncontaminated with MnII-dependent peroxidases. 13C NMR spectrometry of the resulting dehydropolymerisates from 13C-labeled monolignols confirms that the frequencies of different interunit linkages are very similar to those engendered through the action of horseradish peroxidase with H2O2. Indeed, lignin peroxidase does not ultimately seem to be a prerequisite for lignin degradation in vivo, yet its activity can still accelerate the conversion of lignin-derived preparations by P. chrysosporium to CO2. Consequently, lignin peroxidase can provisionally be expected to fulfill two important functions. On the one hand, the enzyme may detoxify lower molecular weight phenolic compounds released from lignins during their fungal decomposition. On the other hand, through the introduction of suitable functional groups, lignin peroxidase could indirectly enhance the susceptibility of macromolecular lignin structures toward depolymerization by another enzyme.

Basidiomycota↗
PubMed1991

[Clinical features of delayed diagnosis in congenital duodenal obstruction].

Delayed diagnosis in two cases of congenital duodenal obstruction was discussed. Case 1. Ten-month-old baby girl with Down's syndrome was admitted to the hospital because of vomiting of milk. Wall-like obstruction was found in the second part of duodenum. Case 2. One-year-old boy infant with Down's syndrome showed a stack of coin in the duodenum on admission. Wall-like obstruction was found in the second part of duodenum. Diagnosis of duodenal obstruction is sometimes delayed in Down's syndrome. Symptom such as vomiting and growth retardation might be ignored in a child with Down's syndrome. A large hole was found in the center of the obstruction in both cases; 4 mm in diameter in case 1, 3 mm in case 2. Papilla of Vater opened at the anal side of the obstruction. These structural particularities played a role in making symptom of duodenal obstruction obscure. Mural obstruction of duodenum was observed in both cases. The obstructions were, in shape, similar to the membraneous stenosis of the duodenum. However, they were not membranes but walls as thick as 4-5 mm. Wall-like duodenal obstruction has not been reported in the literature. It can not be concluded whether mural obstruction in our cases is a new subtype of duodenal obstruction or not.

Down Syndrome↗
PubMed1991

Proton chemical-shift imaging with magnetically and electrically inhomogeneous objects.

Proton chemical-shift imaging with the elimination of three kinds of artifacts caused by main magnetic field inhomogeneities, susceptibility distributions of imaging objects, and the electromagnetic properties of radiofrequency (RF) fields is presented in this paper. In addition, the last of these artifacts, which is dependent upon the conductivity distributions of objects, especially in high-tesla imaging, is also demonstrated experimentally. The method proposed here enables the reconstruction of artifact-free water/fat separation images by using simple image data manipulations without the complicated phase-unwrap process, even with main magnetic field inhomogeneities larger than the chemical-shift difference between water and fat magnetizations.

Electric Conductivity↗
PubMed1991

A horseradish peroxidase study of the fiber orientation in the facial nerve.

Horseradish peroxidase (HRP) was used to investigate the motor fiber orientation in the cat's intratemporal facial nerve. When HRP was applied to the zygomatic rami, HRP-labeled fibers were distributed diffusely throughout the labyrinthine and tympanic segments. On the other hand, distal to the chorda tympani entrance, a well-defined topographical orientation was found in the posterolateral aspect of the nerve. When HRP was applied to the buccal rami, topographical orientation was found in the posteromedial area of the distal mastoid segment. When HRP was applied to the posterior auricular rami, topographical orientation was found in the center to the anterior area of the distal mastoid segment. These results indicate that each branch of the facial motor nerve has a topographical orientation in the distal part of the mastoid segment, while nerve fibers are dispersed in the tympanic and labyrinthine segments.

Animals↗
PubMed1991

Observation of the external aperture of the vestibular aqueduct using three-dimensional surface reconstruction imaging.

Observation of the external aperture of the vestibular aqueduct was hitherto possible only in cadavers or dry temporal bones; however, by applying three-dimensional surface reconstruction imaging, it is now possible to observe solid-looking images of this structure in living humans. When the width of the external aperture of the vestibular aqueduct was measured in 58 people, it was found to be significantly narrower in the affected ears of patients with Meniere's disease than in normal ears.

Chronic Disease↗
PubMed1991

[Effect of uremic middle molecules removed during hemofiltration on the enzyme activity in rat liver cytosol].

It is well known that the products of protein catabolism and some of the intermediates including middle molecules (MM) are a biochemical feature of uremic serum and also the activity of serum alanine aminotransferase decreases relatively. To examine the toxicity of MM, we investigate the effect of MM removed by HF on aminotransferases and peptidases in rat liver cytosol. The following enzymes were selected: aminotransferases (GOT, GPT), leucine aminopeptidase (LAP), gamma-glutamyltranspeptidase (gamma GTP). MM samples were as follows: preparation of MM fraction from each 10 l HF fluid at half intervals of former (F-) and latter (L-) for 5 h. HF of two patients (5 weeks) by 1KD ultrafiltration, and group separation into hydrophobic (Mo) and hydrophilic (Mi) by XAD-4 resin (F-Mo, L-Mo, F-Mi, L-Mi). Except for GOT, the effect of MM were found at the activities decreased on LAP (26-30%), on GPT (5-6%), and increased on gamma GTP (4-23%), as compared to control. We found a little difference in the results by the character of MM (Mo, Mi) and by the intervals of HF (F-, L-). These results suggest that MM might play a role in the formation of uremic peptides.

Aged↗
PubMed1991

An improved ELISA system for the measurement of IgG antibodies against pertussis toxin (PT) and filamentous hemagglutinin (FHA) in human sera.

We have developed a modified assay method for the measurement of antibodies against PT and FHA. Polystyrene balls coated with purified PT and FHA were incubated with standard or test sera, washed, incubated with goat anti-human IgG F(ab')2 conjugated with horseradish peroxidase and then washed again. Peroxidase activity was then measured by color development using o-phenylenediamine. The anti-PT and anti-FHA IgG titers were determined using calibration curves. The assay standard curves for anti-PT and anti-FHA were both linear from 1 to 100 ELISA units per milliliter (EU ml-1), and the assay sensitivity was calculated to be 1 EU ml-1 in both cases. Intra- and inter-assay CVs were both less than 10%. Inter-laboratory assay CVs calculated from the results from four different facilities were 3.3-34.6% (average 14.5%) and 2.1-30.3% (average 13.6%) for anti-PT and anti-FHA IgG, respectively, and the correlation coefficient between the Chinese hamster ovary (CHO) cell assay and the anti-PT PS-ball ELISA assay was 0.959. Using this assay method we obtained in a highly sensitive and reproducible measurement of IgG antibodies against PT and FHA in human sera. This assay should be especially useful for the determination of low concentrations of these antibodies.

Adhesins, Bacterial↗
PubMed1990

A subunit of yeast site-specific endonuclease SceI is a mitochondrial version of the 70-kDa heat shock protein.

Endo.SceI of Saccharomyces cerevisiae is a heterodimeric site-specific endonuclease, which is distinguishable from prokaryotic restriction endonucleases in the mode of recognition of its cleavage site. We have used monoclonal antibodies specific to the larger subunit (75 kDa) of Endo.SceI to isolate the gene for the subunit (ENS1) from S. cerevisiae. Unexpectedly, ENS1 was found to encode a 70-kDa heat shock protein-related polypeptide and to be identical to recently cloned SSC1. Subcellular fractionation experiments on yeast cells revealed that the primary target site of the larger subunit is mitochondria, where almost all the Endo.SceI activity is localized. Molecular genetic analysis of ENS1 demonstrated its indispensability for growth and the requirement of a high level of its expression at the sporulation and germination stages. The data suggest that ENS1 plays an important role, especially at these differentiation stages.

Amino Acid Sequence↗
PubMed1990

[Selective resection of the distal bile duct in a high risk patient with polypoid cancer of the intrapancreatic bile duct].

An 81-year-old man who had suffered from hypertension for the preceding three years was admitted as an emergency to the department of neurology of our hospital with the chief complaint of dysarthria. He was diagnosed to have multiple lacunar cerebral infarcts by cranial CT, while the laboratory data showed liver dysfunction characteristic of cholestasis. Mild respiratory insufficiency and renal dysfunction were also found. Further radiological examinations on the liver and biliary tree (US, CT and ERC) were performed, and they revealed that the common bile duct was dilated due to two stone-like masses. He was referred to our department of surgery and underwent laparotomy. Intraoperative endoscopy disclosed intraductal papillomatous lesions. Because of the multiple complications of the patient, resection of the entire common bile duct including the gallbladder and the papilla of Vater without any resection of the pancreas was performed instead of pancreatoduodenectomy. The postoperative course was uneventful and he was discharged on the 31st POD. One year after operation, there is no sign of recurrence either clinically or radiologically. The potentially curative operation for cancer of the distal bile duct is pancreatoduodenectomy, but this is of so great a surgical stress that such a high risk case as described above might be unable to survive it. Even if he survived the perioperative period, he might have a poor quality of life due to postoperative complications. The macroscopic appearance of bile duct cancer is correlated to its invasive spread and prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗