Biomedical subjects

W Mizutani

Publications and source records attributed to W Mizutani.

5 recordsLinked to original sources

PubMed2002

Patterning DNA on microm scale on mica.

Double-stranded DNA molecules were patterned by selective adsorption to aminosilane patterns on mica surfaces. Line patterns with 10 microm spacing were made by photolithography and transferred to a polymer stamp. The stamp was then used for applying aminosilane molecules by microcontact-printing technique on mica substrates. We applied DNA in Tris-EDTA (TE) buffer solution on the patterned substrate, and incubated it for 5 min at room temperature. The sample was then rinsed with pure water, and dried with nitrogen gas. Tapping mode force microscopy showed that DNA was adsorbed selectively on the aminosilanized parts of the mica substrate. We also tried to bridge two aluminum electrodes with DNA using AC electrophoresis.

Adsorption↗

PubMed2001

Method for orienting DNA molecules on mica surfaces in one direction for atomic force microscopy imaging.

An efficient method was developed to stretch DNA molecules on an atomically flat surface for AFM imaging. This method involves anchoring DNA molecules from their 5' ends to amino silanized mica surfaces. N-Succinimidyl6-[3'-(2-pyridyldithio) propionamido]hexanoate (LC-SPDP), a heterobifunctional cross-linker with a flexible spacer arm was used for this purpose. Immobilization was carried out by introducing a thiol group to the 5' end of DNA by PCR. Thiolated molecules were then reacted with the cross linker to conjugate with its 2-pyridyl disulphide group via sulfhydryl exchange. The resulting complex was deposited on amino silanized mica where NHS-ester moiety of the cross linker reacted with the primary amino group on the surface. Samples were washed by a current of water and dried by an air jet in one direction parallel to the surface. DNA molecules were fully stretched in one direction on imaging them by AFM.

Aluminum Silicates↗

PubMed2000

Method for stretching DNA molecules on mica surface in one direction for AFM imaging.

An efficient method was developed to stretch DNA molecules on an atomically flat surface for AFM imaging. This method involves anchoring DNA molecules from their 5' ends to amino silanized mica surfaces. N-Succinimidyl6-[3'-(2-pyridyldithio) propionamido]hexanoate (LC-SPDP), a heterobifunctional cross-linker with a flexible spacer arm was used for this purpose. The immobilization process was carried out by introducing a thiol group to the 5' end of DNA by PCR. Thiolated molecules were then reacted with the cross linker to conjugate with its 2-pyridyl disulphide group via sulfhydryl exchange. The resulting complex was deposited on amino silanized mica where NHS-ester moiety of the cross linker reacted with the primary amino group on the surface. Samples were washed by a current of water and dried by an air jet in one direction parallel to the surface. DNA molecules were shown to be fully stretched in one direction on imaging them by AFM.

Aluminum Silicates↗

PubMed1991

An approach to imaging of living cell surface topography by scanning tunneling microscopy.

Since a scanning tunneling microscope (STM) was developed, an observation of living cell surface has been one of the final aims in the biological application of STM. By developing a new style of STM which was combined with an optical microscope and with a novel system for the centering of both images, we successfully got the STM images of living cell surface of T24 cells (human bladder cancer cell line) and CHO cells (Chinese hamster ovary fibroblast) cultured on highly oriented pyrolytic graphite under the appropriate condition (V greater than 8.0 V, I less than 0.2 nA). Unexpectedly, the living T24 cell showed a slightly uneven surface with a steep foot slope. The CHO cell showed more rough surface with steeper slope of cell foot. Although the STM system had a fine spatial resolution less than 3 nm, the profile of living cell surface covered with electrolyte was clear only when the scanning area was more than 10 microns square.

Animals↗

PubMed1984

Lupus foot: deforming arthropathy of the feet in systemic lupus erythematosus.

Passively correctable joint deformities of the feet were found in 13 of 14 (82.8%) systemic lupus erythematosus (SLE) patients with deforming arthropathy of the hands (Jaccoud's type of arthropathy). These included hallux valgus, subluxation of the metatarsophalangeal joints and widening of the forefoot. Erosive or cystic changes of bone and cartilage were not seen. In contrast, only 4 of 16 (25%) SLE patients without hand deformities, matched for age and duration of the disease, showed similar joint deformities of the feet. Jaccoud's type of arthropathy in SLE is characterized not only by passively correctable joint deformities of the hands but of the feet as well.

Adult↗