Showing papers by "Masaru Tanaka published in 2013"

The roles of water molecules at the biointerface of medical polymers

Abstract: A number of biomaterials have been proposed, including hydrophilic, phase-separated and zwitterionic polymers. It has not been clearly elucidated which mechanisms are responsible for biocompatibility on a molecular level. Water interactions have been recognized as a fundamental part of the biological response to contact with biomaterials. We have proposed the ‘intermediate water’ concept; the water exhibited both clear peak for cold crystallization in differential scanning calorimetry chart and a strong peak at 3400 cm−1 in a time-resolved infrared spectrum. We found the localized hydration structure consisting of the three hydrated water in poly(2-methoxyethyl acrylate) (PMEA).

Microporous "honeycomb" films support enhanced bone formation in vitro

Abstract: Substrate topography influences cell adhesion, proliferation, and differentiation. In this study, poly (e-caprolactone) (PCL) films with a well-defined honeycomb structure of porosity 3-4, 5-6, 10-11, or 15-16 μm were contrasted with flat surfaces for their ability to support primary rat osteoblast adhesion and mineralized extracellular matrix deposition in vitro. Immunofluorescent visualization of vinculin and rhodamine phalloidin binding of actin were used to investigate cell adhesion and morphology. Localization of the alkaline phosphatase activity and Alizarin Red staining were performed to assess the osteoblast activity and deposition of a mineralized matrix. Scanning electron microscopy together with energy-dispersive X-ray spectroscopy was used to provide morphological analysis of cell-film interactions, the deposited matrix, and elemental analysis of the mineralized structures. After 24 h of culture, there were no differences in cell numbers on porous or flat PCL surfaces, but there were changes in cell morphology. Osteoblasts on honeycomb films had a smaller surface area and were less circular than cells on flat PCL. Analysis of cells cultured for 35 days under osteogenic conditions revealed that osteoblasts on all substrates acquired alkaline phosphatase activity, but levels of mineralized matrix were increased on films with 3-4-μm pore sizes. The bone-like matrix with a Ca:P ratio of 1.69±0.08 could be identified in larger areas often aligning with substrate topography. In addition, smaller spherical deposits (0.5-1 μm in diameter) with a Ca:P ratio of 1.3±0.08 were observed at the surface and particularly within the pores of the PCL film. Localization of vinculin showed significant decreases in the number of focal adhesion structures per unit cell area on 5-6, 10-11, and 15-16-μm surfaces compared to flat PCL, while focal complexes with a smaller area (0-2 μm(2)) were more abundant on 3-4 and 5-6-μm surfaces. Observation of cell interaction with these surfaces identified cytoplasmic protrusions that extended into and sealed the pores of these PCL films creating an extracellular space in which, the conditions could influence the deposition and formation of the mineralized matrix.

Inguinal porokeratosis in a Japanese man.

Abstract: Inguinal and genital porokeratosis are rare but seem to be more common in Asians. We report a case of a 69-year-old Japanese man with multiple lesions of porokeratosis in both inguinal regions. The lesions first appeared in the inguinal region and subsequently spread to the trunk. The patient reported that his father had had similar lesions. Dermoscopy demonstrated central brown pigmentation and blue-gray dots surrounded by a single "white track" at the periphery. The exterior border of the white track also showed light brown pigmentation. Genital or inguinal porokeratosis is uncommon and may be misdiagnosed as Bowen's disease, lichen planus or extramammary Paget's disease. However, awareness of this entity and the use of dermoscopy are helpful to establish a correct diagnosis.

Self-assembly of a simple low-cost dermoscope for examination of skin lesions.

Abstract: Dermoscopy is helpful not only in the early differentiation of melanoma from nevus and other pigmented skin lesions, but also in the diagnosis of non-pigmented skin lesions. However, the dermoscopy device, or dermoscope (or dermatoscope), is usually viewed as either unnecessary or expensive by young dermatologists. In reality, there is no need to buy one to start learning/practicing dermoscopy because all the components of such device are already available in most dermatology clinics; all that is needed is the assembly of the different components to construct a dermoscope and use it to examine pigmented skin lesions. The assembly of a dermo-scope requires four items: echo-gel, a glass slide, a penlight or electric torch, and an eyepiece lens of a microscope (or a 10-power magnifying lens). The assembly process is simple and includes placing an appropriate amount of echo-gel on the skin lesion, then mounting a glass slide, illumination of the lesion at an angle from above using a torch, and lastly, examination of the lesion using the eyepiece lens (Figure 1). All dermatologists who do not have a commercial dermoscope are encouraged to try this and start dermoscopic examination in the outpatient clinic! Figure 1. The assembly process includes placing echo-gel on the skin lesion, then mounting a glass slide, illumination of the lesion at an angle from above using a torch, and examination of the lesion using the eyepiece lens. [Copyright: ©2013 Sawada et ...

Biocompatible material, medical instrument and method for using medical instrument

Abstract: PROBLEM TO BE SOLVED: To provide a biocompatible material excellent in antithrombogenic property, a medical instrument and a method for using a biocompatible material.SOLUTION: The biocompatible material contains a mixture of a polymer which maintains a glassy mixed phase with polyacrylic acid 2-methoxyethyl in a room temperature and the polyacrylic acid 2-methoxyethyl. Here, a ratio of the polyacrylic acid 2-methoxyethyl to polymethyl methacrylate as a mixed weight ratio of the polymethyl methacrylate to the polyacrylic acid 2-methoxyethyl in the mixture is within a range of 1:99-90:10. The mixture has an inclined structure in which the polyacrylic acid 2-methoxyethyl is segregated on a surface side.

Squamous cell carcinoma of the soft palate associated with autoantibodies to desmoglein 1 and 3

Abstract: The desmogleins are a family of cadherins cell-cell adhesion molecules consisting of proteins DSG1, DSG2, DSG3, and DSG4. They play a role in the formation of desmosomes, which form the major types of intercellular adhesive junctions. DSGs are currently thought to be involved in autoimmune diseases, infectious diseases, and inherited diseases. Patients with pemphigus, an autoimmune blistering disease of the skin and mucous membranes, carry IgG autoantibodies directed against DSG1 and DSG3 [1]. Pemphigus vulgaris antigen is also considered a tissue-specific type of desmoglein [1].

Peristomal Pagetoid Spread of Urothelial Carcinoma of the Ureter

Abstract: Patients with ostomy including urinary stoma often develop peristomal complications, especially skin damage. The patient in this case was a 69-year old female with a history of urothelial carcinoma of the bladder and left ureter who underwent transurethral resection of a bladder tumor, nephroureterectomy and cystectomy combined with ureterocutaneostomy. Later, she had recurrence of urothelial carcinoma in the remaining ureter that spread to the peristomal epidermis, with a skin appearance resembling Paget’s disease. We report this case based on its clinical significance since we believe it is the first description of this condition in the literature.