Tsurumi University

About: Tsurumi University is a education organization based out in Yokohama, Japan. It is known for research contribution in the topics: Enamel paint & Periodontal fiber. The organization has 1491 authors who have published 2336 publications receiving 42740 citations. The organization is also known as: Tsurumi daigaku.

Suppression of basal autophagy in neural cells causes neurodegenerative disease in mice

Abstract: Autophagy is an intracellular bulk degradation process through which a portion of the cytoplasm is delivered to lysosomes to be degraded. Although the primary role of autophagy in many organisms is in adaptation to starvation, autophagy is also thought to be important for normal turnover of cytoplasmic contents, particularly in quiescent cells such as neurons. Autophagy may have a protective role against the development of a number of neurodegenerative diseases. Here we report that loss of autophagy causes neurodegeneration even in the absence of any disease-associated mutant proteins. Mice deficient for Atg5 (autophagy-related 5) specifically in neural cells develop progressive deficits in motor function that are accompanied by the accumulation of cytoplasmic inclusion bodies in neurons. In Atg5-/- cells, diffuse, abnormal intracellular proteins accumulate, and then form aggregates and inclusions. These results suggest that the continuous clearance of diffuse cytosolic proteins through basal autophagy is important for preventing the accumulation of abnormal proteins, which can disrupt neural function and ultimately lead to neurodegeneration.

Use of a new adhesive film for the preparation of multi-purpose fresh-frozen sections from hard tissues, whole-animals, insects and plants.

Abstract: A method for preparing thin fresh-frozen sections from large samples and hard tissues is described and the applications are shown. A new adhesive film is introduced to produce the frozen sections. The sample is frozen in a cooled hexane or liquid nitrogen, and then freeze-embedded with 4-5% carboxymethyl cellulose (CMC) in the coolant. A specially prepared adhesive film is fastened to the cut surface of the sample in order to support the section and cut slowly with a disposable tungsten carbide blade. The adhesive film is made of a thin plastic film and an adhesive before use. This method produces 2-microm thick fresh-frozen sections from a large sample, bone or tooth. The "film-section" i.e. the section attached to the adhesive film, can be used for many types of studies such as histology, general histochemistry, enzyme histochemistry, immunohistochemistry, in situ hybridization, elemental analysis, and autoradiography for water-soluble materials. Immunohistochemistry and in situ hybridization can be carried out with nonfixed and undecalcified sections. The section on the adhesive film can be transferred to a glass slide and mounted under a cover slip, and stained sections can be examined with an optical microscope at high magnification. This method is also useful for preparing frozen sections from samples of fish, insects, and plants. Furthermore, samples of particular areas can be collected from the film-section by means of a laser microdissection technique. The multiple possible applications of the adhesive film render it highly useful for studies in biological and medico-dental fields.

The international workshop on meibomian gland dysfunction: report of the subcommittee on management and treatment of meibomian gland dysfunction.

Abstract: The goals of the subcommittee were to review the current practice and published evidence of medical and surgical treatment options for meibomian gland dysfunction (MGD) and to identify areas with conflicting, or lack of, evidence, observations, concepts, or even mechanisms where further research is required. To achieve these goals, a comprehensive review of clinical textbooks and the scientific literature was performed and the quality of published evidence graded according to an agreed on standard, using objective criteria for clinical and basic research studies adapted from the American Academy of Ophthalmology Practice Guidelines1 (Table 1). It should be noted that, in many of the clinical textbooks and previous reports, terminology is often interchanged and the management of anterior and posterior blepharitis and/or meibomitis is often considered concurrently. Thus, a broad scope of documents was reviewed in this process. Consistency in terminology and global adoption of the term “meibomian gland dysfunction” would significantly aid clinical research and clinical care in MGD going forward. Table 1. Grading Level of Evidence of Clinical and Basic Research Studies1

Negligible immunogenicity of terminally differentiated cells derived from induced pluripotent or embryonic stem cells

Abstract: Immune rejection may limit the therapeutic use of induced pluripotent stem cells (iPSCs); here, terminally differentiated mouse iPSCs are shown to generate negligible immune rejection in their host. Induced pluripotent stem cells (iPSCs) derived from a patient's own somatic cells could have great therapeutic potential. The hope is that iPSC-derived differentiated cells would avoid any immunogenic responses. In this study, Masumi Abe and colleagues assess the immunogenicity of skin and bone marrow tissues derived from a large set of isogenic mouse embryonic stem cell and iPSC lines. Their results are consistent with negligible immune rejection by the host. The advantages of using induced pluripotent stem cells (iPSCs) instead of embryonic stem (ES) cells in regenerative medicine centre around circumventing concerns about the ethics of using ES cells and the likelihood of immune rejection of ES-cell-derived tissues1,2. However, partial reprogramming and genetic instabilities in iPSCs3,4,5,6 could elicit immune responses in transplant recipients even when iPSC-derived differentiated cells are transplanted. iPSCs are first differentiated into specific types of cells in vitro for subsequent transplantation. Although model transplantation experiments have been conducted using various iPSC-derived differentiated tissues7,8,9,10 and immune rejections have not been observed, careful investigation of the immunogenicity of iPSC-derived tissue is becoming increasingly critical, especially as this has not been the focus of most studies done so far. A recent study reported immunogenicity of iPSC- but not ES-cell-derived teratomas11 and implicated several causative genes. Nevertheless, some controversy has arisen regarding these findings12. Here we examine the immunogenicity of differentiated skin and bone marrow tissues derived from mouse iPSCs. To ensure optimal comparison of iPSCs and ES cells, we established ten integration-free iPSC and seven ES-cell lines using an inbred mouse strain, C57BL/6. We observed no differences in the rate of success of transplantation when skin and bone marrow cells derived from iPSCs were compared with ES-cell-derived tissues. Moreover, we observed limited or no immune responses, including T-cell infiltration, for tissues derived from either iPSCs or ES cells, and no increase in the expression of the immunogenicity-causing Zg16 and Hormad1 genes in regressing skin and teratoma tissues. Our findings suggest limited immunogenicity of transplanted cells differentiated from iPSCs and ES cells.

Resolution-enhanced Fourier transform infrared spectroscopy study of the environment of phosphate ion in the early deposits of a solid phase of calcium phosphate in bone and enamel and their evolution with age: 2. Investigations in the nu3PO4 domain.

Abstract: In order to investigate the possible existence in biological and poorly crystalline synthetic apatites of local atomic organizations different from that of apatite, resolution-enhanced, Fourier transform infrared spectroscopy studies were carried out on chicken bone, pig enamel, and poorly crystalline synthetic apatites containing carbonate and HPO4 2− groups. The spectra obtained were compared to those of synthetic well crystallized apatites (stoichiometric hydroxyapatite, HPO4 2−-containing apatite, type B carbonate apatite) and nonapatitic calcium phosphates which have been suggested as precursors of the apatitic phase [octacalcium phosphate (OCP), brushite, and β tricalcium phosphate and whitlockite]. The spectra of bone and enamel, as well as poorly crystalline, synthetic apatite in thev 4 PO4 domain, exhibit, in addition to the three apatitic bands, three absorption bands that were shown to be independent of the organic matrix. Two low-wave number bands at 520–530 and 540–550 cm−1 are assigned to HPO4 2−. Reference to known calcium phosphates shows that bands in this domain also exist in HPO4 2−-containing apatite, brushite, and OCP. However, the lack of specific absorption bands prevents a clear identification of these HPO4 2− environments. The third absorption band (610–615 cm−1) is not related to HPO4 2− or OH− ions. It appears to be due to a labile PO4 3− environment which could not be identified with any phosphate environment existing in our reference samples, and thus seems specific of poorly crystalline apatites. Correlation of the variations in band intensities show that 610–615 cm−1 band is related to an absorption band at 560 cm−1 superimposed on an apatite band. All the nonapatitic phosphate environments were shown to decrease during aging of enamel, bone, and synthetic apatites. Moreover, EDTA etching show that the labile PO4 3− environment exhibited a heterogeneous distribution in the insoluble precipitate.