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Biomedical subjects

E Yamamoto

Publications and source records attributed to E Yamamoto.

At least 163 records · Page 9Linked to original sources
PubMed1990

Differences in endocochlear potentials in response to anoxia in maturing and mature guinea pigs.

Endocochlear potential (EP) responses to anoxia in immature and mature guinea pigs were compared. The EP decreased much more slowly after anoxia in guinea-pig embryos than in neonates. In many of the embryos, the EP failed to reach any negative voltage. These findings show that the development of the negative component of the EP is a function of the maturation of its positive component.

Action Potentials↗
PubMed1990

Formation of cis-coniferin in cell-free extracts of Fagus grandifolia Ehrh bark.

American beech (Fagus grandifolia Ehrh) bark exclusively accumulates cis-monolignols and their glucosidic conjugates; no evidence for the accumulation of trans-monolignols has been found. The glucosyltransferase from this source exhibits a very unusual substrate specificity for cis, and not trans, monolignols. This is further evidence that cis monolignols are involved in lignin formation in these plant tissues. Preliminary evidence for the existence of a novel trans-cis monolignol isomerase was obtained, in agreement with our contention that this isomerization is not photochemically mediated.

Cell Wall↗
PubMed1990

[Report of a case--adenoma of the middle ear].

A 44-year-old female with adenoma of the middle ear was reported. Her chief complaint was hearing loss in the right ear. A white mass inside the right external auditory canal was observed. Audiometry revealed a combined deafness with the average hearing of 38.3 dB for the speech frequencies. The study by high resolution X-ray CT revealed a density area as like as a soft mass in the tympanic cavity. A tumor existing mainly in the hypotympanum was surgically removed and modified type III tympanoplasty by interposing the malleus head as an autograft as a columella was done. Postoperative course was good and the average hearing improved slightly to 30 dB. Histopathological study with stains of HE, PAS, mucicarmin, colloid iron, NSE and S-100 protein showed adenoma of the middle ear.

Adenoma↗
PubMed1990

[Fluorescent chromatogram profiles of uremic hemodialyzates and cirrhosis urines].

The unidentified fluorescence develop in body fluids during uremia and cirrhosis. We have used "hydrophobic" HPLC to profile these fluorescence in both 10 uremic hemodialyzates and 5 cirrhosis urines, and studied further to characterize the fluorescence and to gain more information of uremic fluorescent middle molecules. Chromatograms indicate evidently that the fluorescent substances are present in the middle molecule fraction of both hemodialyzates and urines. With reference to the chromatogram scale, the relative levels of fluorescent middle molecule in hemodialyzates were seemed 30% lower than the levels in urines, whereas the mean number of chromatogram peaks in hemodialyzates were 2-fold more than the number in urines. These unknown fluorescence have an excitation of 366 nm before and behind, and may produce more stable fluorescence of middle molecules by acid hydrolysis. These results suggest that there are possibly various modification on the uremic fluorescent substances.

Adult↗
PubMed1989

[Clinical analysis of 26 cases of multiple primary cancer].

Of 412 head and neck cancers in the Department of oral Surgery, Sapporo Medical College from 1976 to 1987, 26 cases (6.3%) were multiple primary cancers. One of these cases was triple cancer. The ages of these 26 cases ranged from 42 to 81 (average 61 year-old) with 20 males and 6 females (3.3:1). As to the interval between the first and second cancer, five cases (20%) were synchronous and twenty cases (80%) were metachronous in our series. Of the five synchronous, three were found by careful examination at the time of admission to our department. The stomach and head and neck cancers were frequently observed as the first cancer of metachronous cases. Second primary cancers occurred in the head and neck region were 64% and those in other regions were 36%. On the other hand, digestive cancer was predominant in the additional cancer to the index cancer (66.7%). These numbers emphasize that patients with head and neck cancers are in a cancer-prone group that develops digestive cancers. These findings have important implications in follow up policy.

Adenocarcinoma↗
PubMed1989

Effects of benzodiazepine and GABA antagonists on anticonflict effects of antianxiety drugs injected into the rat amygdala in a water-lick suppression test.

In order to elucidate the role of the amygdala in rat conflict behavior in a water lick suppression test, we examined the effect of lesions of various nuclei of the amygdaloid complex on this behavior. An anticonflict effect was produced by a lesion of the anterior part of central and basolateral amygdala, and lesion to the posterior part of the central amygdala, but not by posterior of the basolateral amygdala or medial amygdala lesions. These results suggest that the amygdala, especially the anterior part of the central and basolateral nuclei, plays an important role in conflicting behavior of rats in the water lick test. In a second experiment, the effects of benzodiazepine- and GABA-antagonists on the anticonflict action of diazepam, zopiclone, and phenobarbital injected into the anterior part of central and basolateral amygdala were examined, also using a water lick suppression test. A dose-dependent anticonflict action was produced by systemic administration as well as by intra-amygdala injection of diazepam, zopiclone, lormetazepam, flurazepam and phenobarbital. The order of potency was lormetazepam greater than zopiclone greater than or equal to diazepam greater than flurazepam greater than or equal to phenobarbital for both routes of injection. The anticonflict effects of diazepam and zopiclone injected into the amygdala were completely reversed by Ro15-1788 and beta-CCM but not by bicuculline, while the anticonflict effect of phenobarbital was reversed by beta-CCM but not by Ro15-1788 or bicuculline. The present results strongly suggest that the anterior nuclei of central and basolateral amygdala are important sites of action of antianxiety drugs, and that an anticonflict action produced by intra-amygdala injection of benzodiazepines or barbiturate is mediated through the different receptor mechanisms.

Amygdala↗
PubMed1989

A simplified Master's two-step test for preschool children.

To investigate the usefulness of a simplified Master's two step test (s-MTT) for preschool children aged 4-6, s-MTT was carried out in our pediatric cardiology clinic using a new stair and connector for joining the leads from each child to the ECG machine. The subjects were 21 children with Kawasaki disease without coronary involvement and four children with arrhythmias. The treadmill exercise test (TET) was done on the same day to compare the exercise load of s-MTT with that of TET. Oxygen uptake during s-MTT was also examined using another group consisting of eight outpatients. There were no differences in indices such as peak heart rate (HR), HR immediately after exercise, and performance ratio between the outpatients in this study and kindergarteners in the preliminary report. The proportions of peak HR and HR immediately after exercise in s-MTT to those in TET were 91.1 +/- 7.9 (mean +/- SD)% and 91.1 +/- 8.6%, respectively. The average oxygen uptake of the eight outpatients in s-MTT was 23.2 +/- 4.1 ml/min/kg. These studies suggest that the simplified MTT is useful as a screening test, because it can be done for all children aged 4-6 in any laboratory.

Cardiovascular Diseases↗
PubMed1989

[The clinical application of oxygen saturation pulse oximeter in otolaryngological field].

Recently, we had opportunity to use an oxygen saturation pulse oximeter (minolta pulsox-7) which is a compact, light-weight device and allows continuous, percutaneous easy determination of arterial blood oxygen saturation. We obtained the following results from clinical application of this device in the field of otorhinolaryngology. 1. There was a high coefficient of correlation (0.899) between the values of oxygen saturation determined with a Minolta Pulsox-7 and an arterial blood gas analyzer. 2. This instrument was simple to handle and was clinically applicable, and seems to be highly useful for a) timing of tracheostomy, b) objective evaluation of dyspnea, c) monitor of nasal surgery under local anesthesia.

Adult↗
PubMed1989

[Secondary metastasis after excision of oral squamous cancer without local recurrence].

A secondary metastasis after surgery was uncovered in 12 out of 73 cases of oral squamous cancer. The clinical and histological characteristic tendencies of the metastasis of these 12 cases were the tongue as the tumor site (11/12), and an aggressive invasion in the tumor-host borderline with 2 of Gr, 3, 5 of Gr. 4C and 5 of Gr. 4D, according to the grading of Yamamoto and Kohama (1982). The control of these metastases was not easy because of their multiple and extra-nodal spread. Tumor-free survival occurred in 4 out of 11 (36.3%). Therefore, in some situations, a prophylactic neck dissection would seem to be recommended.

Aged↗
PubMed1989

[Histological malignancy grading of oral squamous cell carcinomas].

UNLABELLED: A modification of Jakobsson's criteria that determines the mode of cancer invasion (Yamamoto, 1982) has been reported to be useful in predicting the prognosis in patients with an oral squamous cell carcinoma. In this retrospective study, a five-factorial grading system of the histological malignancy (+ the differentiations, the nuclear polymorphism, the mitoses, and the cellular response) was evaluated in relation to clinical course of each patient. RESULT: 75 cases were classified into four grades from Grade 1, the lowest malignancy, to Grade 4, the highest malignancy. The percentage metastases was 10, 24, 54, and 75% for each grade, respectively. The percentage of survival was 75, 75, 35, and 25% for each grade, respectively. From these results, this grading system was seen to have a close-correlation with the clinical course of each patient.

Adult↗
PubMed1989

[Inhibitory effect of uremic fluorescent substances on the cellular energy generation].

The toxicity of uremic fluorescent substances (F-ure) in hemofiltrates of a dialysis patient on the respiration of rat liver mitochondria was studied in comparison with some fluorescent substances (F-cir) in a cirrhosis urine. These substances found in both the body fluid of chronic disease were fractionated by hydrophobic HPLC. And the characteristic of (1) F-ure and (2) F-cir was as follows: the hydrophobicity based on Sasagawa's constant, (1) 1.1 approximately 1.3 & (2) 1.8; lambda max in UV spectrum, (1) 231, 356 nm & (2) 220 approximately 230, 290 nm; Em in fluorescence, (1) 461 nm & (2) 361 or 504 approximately 7 nm. When F-ure was added into mitochondrial respiratory medium, the respiration of succinate (State 4) decreased about a half in the presence of phosphate and succinate/ADP respiration (State 3) was much suppressed. And about a quarter of this suppression was released by an uncoupled (SF-6847), whereas F-cir on the state 3 respiration showed to be stimulative effect in like manner of uncoupler. The toxicity of uremic fluorescent substances on cellular energy generation could be demonstrated by decreased respiration of mitochondria.

Animals↗
PubMed1988

Localized amyloidosis of the uterine cervix.

Localized amyloidosis of the uterine cervix was found in a 56-year-old woman. The firm enlarged cervix showed massive tumorous amyloid deposition. In the amyloid deposits there were foci of ossification and calcification. An infiltrate of multinucleated giant cells, histiocytes, lymphocytes, and plasma cells was seen adjacent to the amyloid deposits. Immunohistochemically, the amyloid reacted with antisera against A-lambda, amyloid protein of immunoglobulin lambda light chain origin. This indicated that the amyloid protein was of immunoglobulin origin in this rare case of localized amyloidosis of the uterine cervix.

Amyloidosis↗
PubMed1988

Exclusive accumulation of Z-isomers of monolignols and their glucosides in bark of Fagus grandifolia.

In addition to Z-coniferyl and Z-sinapyl alcohols, bark extracts of Fagus grandifolia also contain significant amounts of the glucosides, Z-coniferin, Z-isoconiferin (previously called faguside) and Z-syringin. The corresponding E-isomers of these glucosides do not accumulate to a detectable level. The accumulation of the Z-isomers suggests that either they are not lignin precursors or that they are reservoirs of monolignols for subsequent lignin biosynthesis; it is not possible to distinguish between these alternatives. The co-occurrence of Z-coniferin and Z-isoconiferin demonstrate that glucosylation of monolignols can occur at either the phenolic or the allylic hydroxyl groups.

Acetylation↗
PubMed1988

Experimental study on facial nerve suturing--comparison between epineural and perineural sutures.

A comparison was made between epineural and perineural sutures using the orbicular is oculi branches of facial nerves of 30 cats. Nerve regeneration was slightly reduced with perineural suture without a tube compared with epineural suture with a tube, epineural suture without a tube and perineural suture with a tube, which showed similar results. A good regeneration was observed when approximation was made without tension at both cut ends of the perineurium. When the corresponding funiculus cannot be identified, epineural suture is considered sufficient.

Anastomosis, Surgical↗
PubMed1988

Epimerization kinetics of moxalactam in frozen solution.

The epimerization rate constants of R- and S-epimers of moxalactam (LMOX) in a frozen aqueous solution decreased as the temperature decreased. The reaction proceeded in the unfrozen region remaining in the frozen solution, without being affected by the ice. The reaction stopped completely below the collapse temperature of the LMOX aqueous solution. The ratio of R- and S-epimers at equilibrium, which was equal to the ratio of the epimerization rate constant, increased as the temperature decreased. This change in the ratio at equilibrium could be ascribed to the difference in the activation energy between the two epimers.

Chromatography, High Pressure Liquid↗
PubMed1988

Reliability of percutaneous test for facial nerve function. Comparison between indirect and direct stimulation method.

To evaluate the reliability of conventional tests for facial nerve denervation, comparisons of the thresholds and relationship with prognosis were made between the conventional percutaneous and direct stimulation methods in 11 cases of facial palsy decompressed and followed up for more than 6 months. Although all cases showed complete or severe nerve degeneration in the preoperative percutaneous stimulation test, the threshold for the direct intraoperative stimulation test varied from 4 V (normal) to more than 30 V. The results of the direct intraoperative stimulation test correlated well with prognosis (degree of improvement of palsy score). Our results indicate that the direct stimulation method is better than the percutaneous stimulation method as an electrodiagnostic test for nerve degeneration.

Adolescent↗