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Biomedical subjects

T Yoshimatsu

Publications and source records attributed to T Yoshimatsu.

At least 91 records · Page 5Linked to original sources
PubMed1990

The prevalence of sensitivity to constituents of dental alloys.

Ninety-five participants were epicutaneous patch tested in order to determine the prevalence of sensitivity to components of dental alloys. Seventeen individuals (17.9%) developed allergic reactions, which were caused by mercury (10.5%), copper (2.1%), nickel, cobalt, tin, gold and zinc (1.1%). Eight of 17 allergic responders had a history of dermatitis from metal contact. The results show that there is a need for careful immunological considerations during the selection of suitable alloys, particularly in the case of patients with lesions suspected of being caused by dental alloys.

Adult↗
PubMed1990

[Muscle activities in the region of neck, shoulder and back during isometric horizontal jaw exercises in various postures].

Eleven healthy participants were made to perform isometric horizontal jaw movements with maximum voluntary efforts in various postures. Surface EMGs from the laterocervical, nucha, shoulder and back regions were bilaterally picked up, and simultaneously recorded with jaw force. The results obtained were as follows: 1. Electromyographic power value in these regions depended on the directions of the jaw exercises (posteriorly pull greater than posterolaterally pull greater than anteriorly push not equal to anterolaterally push, P less than 0.0001). 2. The directional effects mentioned above were significantly obvious in the inferior laterocervical (Electrode No. 2) and back Electrode No. 5) regions (P less than 0.0001). 3. The postural effects on the power value were varied with the directions of the jaw exercises (P not equal to 0.03); i.e., the highest value during jaw pull was observed in an upright position, while that during jaw push was found in a supine position. 4. From above results, it would be considered that occlusal habits with sustained isometric jaw retrusion might have higher probability to provoke the discomfortableness in the neck, shoulder and back regions than those with protrusion, and that the habits with the retrusion might be more injurious in a supine than in an upright position, while those with the protrusion more injurious in an upright position.

Adult↗
PubMed1990

[A case of multiple inflammatory tracheo-bronchial polyps associated with chronic sinusitis].

A 57 year-old woman was aware of breath odor and visited to our hospital. There were no abnormal findings in her physical examination and chest X-ray. Multiple polyps in the trachea and both main bronchi were discovered by fiberoptic bronchoscopy. They were 0.1-0.5 cm in diameter. In a histological examination, squamous metaplastic epithelial cells and numerous inflammatory cells infiltrating subepithelially were seen. No malignant cells were found. The patient had suffered from chronic sinusitis for 15 years, and it was suggested that the development of tracheo-bronchial polyps was associated with chronic sinusitis.

Bronchial Neoplasms↗
PubMed1989

Control of gene expression by artificial introns in Saccharomyces cerevisiae.

Artificial yeast introns that show cold-sensitive splicing have been constructed. These conditional introns can be inserted into a target gene as an "intron cassette" without disrupting the coding information, allowing expression of the gene to be cold sensitive. Insertion of these intron cassettes rendered the yeast URA3 gene cold sensitive in its expression. The advantage of this intron-mediated control system is that any gene can be converted to a controllable gene by simple insertion of an intron.

Base Sequence↗
PubMed1989

[Changes of muscle activities in neck and shoulder region during sustained isometric contractions of jaw muscles].

Eight healthy participants performed horizontal isometric jaw movements with maximum voluntary contractions of the jaw muscles until they could not tolerate the task. Electromyographic activities bilaterally recorded from the superior and inferior regions of the sternocleidomastoid muscle and the nuchal and shoulder regions of the trapezius muscle were observed. The results obtained were as follows: 1. In more than 94% of 32 trials, the amplitude of EMGs during the task were higher than those at rest, and in more than 79%, temporal changes in EMG burst were synchronized with the onset-offset of the exercise. 2. In more than 72% of all trials, small amplitude EMG lasted after cessation of the task. 3. Muscle activities of the lateral cervical region during the exercise were superior to the activity of the nuchal and shoulder regions, and amplitude of EMGs in the neck and shoulder regions tended to be the highest during isometric retrusion. 4. These results don't contradict with our hypotheses that occlusal habits might be one cause of the unpleasant sensation in the neck and shoulder regions and that sustained isometric retrusion might have heavier effects on it.

Adult↗
PubMed1989

[Influence of a repetitive commanded acoustic signal with constant frequency on jaw tapping movement].

Influence of a repetitive commanded acoustic signal with constant frequency of 1.3 Hz on jaw tapping movement was studied. 10 healthy subjects were made to perform anticipated jaw tapping movement corresponding to the signal. Jaw tapping movement with and without signal were analyzed for their opening distance and a ratio of duration of opening phase I (depressing phase), opening phase II (plateau phase), closing phase and tooth contact phase to the cycle time. 1. Opening distance in loaded tapping was shorter than that in the tapping ad lib. (P not equal to 0.01), and independently of commanded signal it became to be longer with increasement of trial numbers (P not equal to 0.01). 2. The ratio of duration of tooth contact phase in loaded tapping became smaller with increasement of the trials, although that in the tapping ad lib. became greater (P less than 0.001). 3. The ratio of duration of opening phase I in loaded tapping became greater with increasement of the trials, while that in the tapping ad lib. became smaller (P not equal to 0.01). 4. It could be interpreted that in the loaded tapping "an instant performance control" acted from the beginning of the trials and the signal might make it facile or easy to detect and confirm errors in movement.

Adult↗
PubMed1989

[Clinical evaluations on removability of removable partial dentures].

The following results were obtained from studying the removability of 53 removable partial dentures. 1. All of their retentive forces were less than 2,000 gf. 2. In 5 out of 31 dentures whose retentive forces were graded D2 and less, the wearers could remove the dentures easily without help of their fingers. Out of 22 dentures graded D4 and more, 3 conic dentures were difficult in removal. 3. The wearers were dissatisfied with 3 dentures graded D2 and less, and with 2 conic dentures graded D4. 4. In 12 dentures graded D1, 9 dentures were evaluated to be too loose by the operators. In 12 dentures graded D4 and more, 2 conic dentures were evaluated to be too tight by both the wearers and the operators. 5. All conic dentures complained had 4-degree-tapered conic studs as the retainer. 6. It is considered that in terms of subjective evaluations, an adequate retentive force for the dentures might be in the range from 800 gf to 2,000 gf.

Consumer Behavior↗
PubMed1985

Cloning and structural analysis of a part of the human epidermal growth factor receptor gene.

We screened a gene library constructed with human leukocyte chromosomal DNA fragments with an oligonucleotide probe complementary to the middle part of the cDNA for the human epidermal growth factor receptor. One of the genomic DNA clones obtained contains an insert of 36 kilobase pairs encoding 54% of the mature receptor protein. From the sequencing experiments, we were able to locate the exact site of the gene rearrangement, which had been previously suggested in some epidermoid carcinoma cell lines, in the intron preceding the exon coding for the hydrophobic transmembrane domain. Such a rearrangement must result in the removal of an authentic splicing acceptor site and the separation of the 3'-segment of the receptor gene which could encode a polypeptide homologous to the v-erb-B oncogene product responsible for chicken carcinogenesis.

Base Sequence↗