Biomedical subjects

H Mikuni

Publications and source records attributed to H Mikuni.

6 recordsLinked to original sources

PubMed1998

Type A fibril of the mouse tectorial membrane shows D-periodicity: an atomic force microscopic examination.

This study demonstrated that type A fibrils of the mouse tectorial membrane showed a morphology characteristic of collagen, as demonstrated using an atomic force microscope. In the topographical imaging mode, the surface of the type A fibrils showed a periodic pattern, consisting of alternating grooves and ridges. The periodicity of the type A fibrils was 69.1 +/- 0.6 nm, which is in accordance with characteristic collagen D-periodicity. The difference in height between grooves and ridges was 1.6 +/- 0.3 nm. In the variable deflection imaging mode, the type A fibrils showed a clear banding pattern, which consisted of alternating light and dark zones, with D-periodicity. In addition, the type A fibrils exhibited one minor dark band in the light zone and one minor light band in the dark zone.

Aged↗

PubMed1995

The three-dimensional fibrillar arrangement of the basilar membrane in the mouse cochlea.

The three-dimensional fibrillar arrangement of the basilar membrane in the mouse cochlea was studied using scanning electron microscopy. Fibrils of the basilar membrane were exposed by removing cellular elements of the cochlea using a sodium hydroxide maceration technique. The arrangement of fibrils in the basilar membrane was different between the pars arcuata and pars pectinata. In the pars arcuata, fibrils were arranged in radial and spiral direction, showing a woven pattern. In the pars pectinata, most of the fibrils ran in the radial direction. These findings suggest that the vibration pattern of the pars arcuata and pars pectinata is different when the basilar membrane vibrates.

Animals↗

PubMed1994

Nature of the fine fibrils of the basilar membrane in the cochlea.

Fine fibrils in the basilar membranes of mouse and guinea-pig cochleae were examined by transmission electron microscopy. The fibrils were 10 nm in diameter and ran straight without branching. The fibrils appeared as two parallel lines in longitudinal sections, and round or polygonal in cross-sections, displaying tubular structures with a lumen. They were similar in ultrastructural details to the elastin-associated and elastin-independent microfibrils of Low (1962) in the subcutaneous tissue. It is concluded that the fibrils in the basilar membrane are the microfibrils.

Animals↗

PubMed1992

[Contribution of proliferating cell nuclear antigen to prognostic evaluation of carcinomas of the maxillary sinus].

Proliferating cell nuclear antigen (PCNA) is a nuclear protein, synthesized in the late G1 and S phases of the cell cycle. Therefore, it is considered to be closely related to cell proliferation. The contribution of PCNA to prognostic evaluation of the disease was investigated in 42 squamous cell carcinomas of the maxillary sinuses, retrospectively. Histological sections were prepared by formalin-fixation, paraffin-embedding and staining with monoclonal antibody to PCNA (DAKO, PC10) using the Avidin-biotin peroxidase complex method. The percentage of tumor cells with positive staining for PCNA ranged from 26.3 to 92.3% (average; 61.7%). In order to evaluate PCNA in terms of prognosis, five-year survival rates in the following two groups were compared. One included cases with a PCNA positive rate above the mean level and the other, those below the mean level. Five year survival rate was 30.4% in the group with a higher positive rate, but 42.1% in the group with the lower rate. However, the difference in survival rate between the two groups was not statistically significant. In addition, no correlations either between the rate of PCNA positivity and T-classification of tumors or between the degree of tumor cell differentiation and metastasis to neck lymph nodes were obtained. Further study is necessary to evaluate PCNA as a prognostic marker in human malignancy.

Adult↗

PubMed1989

[Appropriate lymph node dissection in thyroid adenocarcinoma].

Thirty-four patients underwent thyroid surgery for papillary and follicular adenocarcinomas in the period from 1985 to 1989. Fourteen patients were treated with local neck dissection and 20 patients, with modified or radical neck dissection. Cervical lymph node metastasis was found in 25 patients (74%). Our recent policy for lymph node dissection is as follows: When deep cervical lymph node metastasis is clinically demonstrated, radical or modified neck dissection is performed. In patients without clinically demonstrated metastasis, local neck dissection and sampling of the internal jugular chain are performed. When microscopic metastasis is found in frozen sections, modified neck dissection is added. Thus we could select patients for modified neck dissection and choose appropriate neck dissection for more complete cancer clearance without losing postoperative functions.

Adenocarcinoma↗

PubMed1975

Study on the photochemical reaction of HCN and its polymer products relating to primary chemical evolution.

The photochemical reaction of HCN at 184.9 nm is studied in the gas phase. (CN)2, H2, CH4, NH3, N2H4, C2H6, and CH3NH2 are identified as gas phase products, and a reaction mechanism is proposed. HCN polymers are also obtained as solid reaction products, and their structure is investigated by Infrared Spectorscopy, UV-Visible Spectroscopy, Mass Spectrometry, and Amino Acid Analysis. The process and nature of the formation of the polymers are discussed.

Amino Acids↗