Biomedical subjects
K Miyake
Publications and source records attributed to K Miyake.
[Alpha 1-antitrypsin (alpha 1-AT)].
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[Alpha 1-antichymotrypsin (ACT)].
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[Changes in diameter size and F-actin expression in the myocytes of patients with diabetes and streptozotocin-induced diabetes model rats].
Diabetes mellitus may be an independent risk factor for disturbance of cardiac function, but the detailed mechanism remains unclear. In the present study, histological examinations were carried out on 25 hearts from diabetes model rats as well as myocardial biopsy materials from patients with diabetes (n = 25). The mean diameter of the cardiac myocytes in humans was 12.2 +/- 0.5 microns in the control group of patients without diabetes mellitus or hypertension (n = 6), 13.7 +/- 0.8 microns in the hypertension group (n = 3), 9.0 +/- 1.7 microns in the diabetes group (n = 8), and 11.9 +/- 2.0 microns in the diabetes with hypertension group (n = 8). The cardiac myocytes of diabetic patients appeared to be atrophic. Comparison of the size of myocytes in the control rats vs streptozotocin-induced diabetes model rats (n = 7, each) was 5.4 +/- 0.2 vs 5.2 +/- 0.3 microns at 2 weeks; 5.9 +/- 0.1 vs 4.9 +/- 0.9 microns at 12 weeks, and 5.7 +/- 0.1 vs 4.0 +/- 0.2 microns at 24 weeks, respectively, and gradually decreased in streptozotocin rats with aging. Immuno-histochemistry with phaloidin was used to assess F-actin in the cardiac myocytes. The relative cross-sectional area of F-actin in the cardiac myocytes of streptozotocin rats was compared to that in non-streptozotocin rat myocytes. F-actin fluorescence in streptozotocin rats was 89.9 +/- 3.9% at 2 weeks, 77.9 +/- 6.4% at 12 weeks, and 56.8 +/- 5.7% at 24 weeks, indicating a decrease in F-actin. These results suggest that the smaller myocytes observed in patients with diabetes and streptozotocin rats are related to the decrease in F-actin in myocytes.
RP105 is associated with MD-1 and transmits an activation signal in human B cells.
RP105 was originally discovered as a mouse B-cell surface molecule that transmits an activation signal. The signal leads to resistance against irradiation-induced apoptosis and massive B-cell proliferation. Recently, we found that mouse RP105 is associated with another molecule, MD-1. We have isolated here the human MD-1 cDNA. We show that human MD-1 is also associated with human RP105 and has an important role in cell surface expression of RP105. We also describe a monoclonal antibody (MoAb) that recognizes human RP105. Expression of RP105 is restricted to CD19(+) B cells. Histological studies showed that RP105 is expressed mainly on mature B cells in mantle zones. Germinal center cells are either dull or negative. RP105 is thus a novel human B-cell marker that is preferentially expressed on mature B cells. Moreover, the anti-RP105 MoAb activates B cells, leading to increases in cell size, expression of a costimulatory molecule CD80, and DNA synthesis. The B-cell activation pathway using RP105 is conserved in humans.
Mouse MD-1, a molecule that is physically associated with RP105 and positively regulates its expression.
RP105 is a leucine-rich repeat molecule that is expressed on mouse B cells and transmits a growth-promoting signal. An anti-RP105 Ab precipitated additional molecules as well as RP105. These molecules were found to be a mouse homologue of chicken MD-1. Chicken MD-1 was previously isolated as a v-myb-regulated gene, since its transcription increases rapidly after v-myb induction. Mouse MD-1, when transiently expressed as an epitope-tagged protein, is secreted in culture fluid but tethered to the cell surface by coexpressed RP105. An association of these molecules was confirmed by immunoprecipitation with the anti-RP105 Ab and subsequent probing of the epitope tag on MD-1. Moreover, MD-1 has an effect on the expression of RP105. In transient transfection of RP105, the percentage of RP105-positive cells increased more than twice with the coexpression of MD-1. The stable expression of MD-1 conferred approximately a sevenfold increase in cell surface RP105 on a cell line that expresses RP105 alone. Thus, MD-1 is physically associated with RP105 and is important for efficient cell surface expression.
The molecular mechanism of B cell activation by toll-like receptor protein RP-105.
The B cell-specific transmembrane protein RP-105 belongs to the family of Drosophila toll-like proteins which are likely to trigger innate immune responses in mice and man. Here we demonstrate that the Src-family protein tyrosine kinase Lyn, protein kinase C beta I/II (PKCbetaI/II), and Erk2-specific mitogen-activated protein (MAP) kinase kinase (MEK) are essential and probably functionally connected elements of the RP-105-mediated signaling cascade in B cells. We also find that negative regulation of RP-105-mediated activation of MAP kinases by membrane immunoglobulin may account for the phenomenon of antigen receptor-mediated arrest of RP-105-mediated B cell proliferation.
Physical and functional association between thymic shared antigen-1/stem cell antigen-2 and the T cell receptor complex.
Thymic shared antigen-1 (TSA-1)/stem cell Ag-2 (Sca-2) is a glycosylphosphatidylinositol (GPI)-anchored antigen expressed on lymphocytes. We have previously demonstrated that a signal via TSA-1/Sca-2 inhibits T cell receptor (TCR)-mediated T cell activation and apoptosis. To elucidate a molecular mechanism for TSA-1-mediated modulation of the TCR-signaling pathway, we examined whether TSA-1 is physically coupled to the TCR in the present study. TSA-1 was clearly associated with CD3zeta chains in T cell hybridomas, activated T cells, and COS-7 cells transfected with TSA-1 and CD3zeta cDNA. The physical association was confirmed on the surface of T cells in immunoprecipitation and confocal microscopy. The analysis using stable and transient transfectants expressing a transmembrane form of TSA-1 revealed that the association of CD3zeta did not require the GPI anchor of TSA-1. Finally, tyrosine phosphorylation of CD3zeta chains was induced after stimulation with anti-TSA-1, suggesting that a functional association between these two molecules also exists. These results imply that the physical association to CD3zeta underlies a regulatory role of TSA-1/Sca-2 in the TCR-signaling pathway.
B lymphocytes differentially use the Rel and nuclear factor kappaB1 (NF-kappaB1) transcription factors to regulate cell cycle progression and apoptosis in quiescent and mitogen-activated cells.
Rel and nuclear factor (NF)-kappaB1, two members of the Rel/NF-kappaB transcription factor family, are essential for mitogen-induced B cell proliferation. Using mice with inactivated Rel or NF-kappaB1 genes, we show that these transcription factors differentially regulate cell cycle progression and apoptosis in B lymphocytes. Consistent with an increased rate of mature B cell turnover in naive nfkb1-/- mice, the level of apoptosis in cultures of quiescent nfkb1-/-, but not c-rel-/-, B cells is higher. The failure of c-rel-/- or nfkb1-/- B cells to proliferate in response to particular mitogens coincides with a cell cycle block early in G1 and elevated cell death. Expression of a bcl-2 transgene prevents apoptosis in resting and activated c-rel-/- and nfkb1-/- B cells, but does not overcome the block in cell cycle progression, suggesting that the impaired proliferation is not simply a consequence of apoptosis and that Rel/NF-kappaB proteins regulate cell survival and cell cycle control through independent mechanisms. In contrast to certain B lymphoma cell lines in which mitogen-induced cell death can result from Rel/NF-kappaB-dependent downregulation of c-myc, expression of c-myc is normal in resting and stimulated c-rel-/- B cells, indicating that target gene(s) regulated by Rel that are important for preventing apoptosis may differ in normal and immortalized B cells. Collectively, these results are the first to demonstrate that in normal B cells, NF-kappaB1 regulates survival of cells in G0, whereas mitogenic activation induced by distinct stimuli requires different Rel/NF-kappaB factors to control cell cycle progression and prevent apoptosis.
Stable integration of human immunodeficiency virus-based retroviral vectors into the chromosomes of nondividing cells.
Human immunodeficiency virus type 1 (HIV-1)-based vectors are thought to be useful for gene transfer into nondividing cells. We examined whether HIV vectors can really integrate into the chromosomes of nondividing cells. CD4+HeLa cells arrested at the G2 or G1/S phase were incubated with the HIV vector pseudotyped with the HIV envelope. The transduction efficiency of the HIV vector in these nondividing cells was comparable to that in proliferating cells. Sequencing of the polymerase chain reaction-amplified fragments containing the junction sites showed that the HIV vector was stably integrated into the chromosomal DNA. It was also demonstrated that terminally differentiated human macrophages and nonproliferating NT neurons could be transduced by the HIV vector after adenovirus-mediated expression of CD4. These results suggest that the HIV vector may be useful not only for gene therapy of AIDS but also for a variety of gene therapy protocols targeting nondividing cells.
Establishment and characterization of an immortal macrophage-like cell line inducible to differentiate to osteoclasts.
Osteoclasts are hematopoietic cells essential for bone remodeling and resorption. To understand the process of osteoclast development, we established a macrophage-like cell line C7 that has the potential to differentiate into functional osteoclasts; multinuclear tartrate-resistant acid phosphatase positive cells capable of forming pits on dentin slices. C7 cells share the characteristics of their cell surface molecules and phagocytic activity with macrophages. Generation of osteoclasts from C7 cells was mostly suppressed by the addition of a function-blocking antibody directed to c-Fms, the receptor for macrophage-colony stimulating factor (M-CSF), or by osteoclastogenesis inhibitory factor (OCIF). These responses correspond well with the osteoclast precursors present in bone marrow and peritoneal cavity. Reagents such as bacterial lipopolysaccharide and granulocyte/macrophage-CSF that are known to act as inducers for other cell lineages rather than osteoclasts abolished the potential of osteoclastogenesis in C7 cells. These phenotypes of C7 cells have been stably maintained for more than 2 years. We believe that the cell line established in this study will provide an important tool for osteoclast biology.
Staining of the lens capsule for circular continuous capsulorrhexis in eyes with white cataract.
We have developed a technique of staining the anterior capsule with a solution of indocyanine green that facilitates performance of the circular continuous capsulorrhexis in eyes with a mature cataract. We compared the results of phacoemulsification and intraocular lens implantation in 10 eyes with the capsule stained with results of 10 eyes having the same procedure with standard circular continuous capsulorrhexis. The results of specular microscopy and laser flare-cell photometry showed no statistically significant differences between the 2 groups. Although the safety of intraocular indocyanine green dye has not yet been definitively established, the findings of this pilot study suggest that it is safe and useful in visualizing the anterior capsule of a mature cataract during cataract surgery.
A biomimetic electron releasing device: capacitively connected glow discharge electrode.
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Liquefied aftercataract: a complication of continuous curvilinear capsulorhexis and intraocular lens implantation in the lens capsule.
PURPOSE: To describe a new type of aftercataract that contains a liquefied, milky white substance between the lens optic and the posterior lens capsule. METHOD: We reviewed the medical records of 41 patients identified as having this type of aftercataract. RESULTS: All 41 eyes (41 patients) underwent uneventful phacoemulsification after continuous curvilinear capsulorhexis and implantation of a posterior chamber intraocular lens made from polymethylmethacrylate. Two months to 6 years after surgery (average+/-SD, 3.8+/-1.7 years), fibrosis was noted evenly along the entire circumference and between the anterior surface of the intraocular lens optic and the edge of the capsular opening created by continuous curvilinear capsulorhexis. This led to formation of a closed chamber between the intraocular lens and the posterior lens capsule, which then accumulated a liquefied, milky white substance. Twenty-three of the 41 eyes showed liquefied aftercataract in conjunction with other types of aftercataract: in 12 eyes with fibrosis, in 11 eyes with Elschnig pearls, and in one eye with a Soemmering ring. None of the eyes had any signs of inflammation; six of the 41 eyes had reduced visual acuity caused exclusively by the liquefied aftercataract. Before cataract surgery, 14 eyes were diagnosed with diabetic retinopathy, four with glaucoma, and two with uveitis. CONCLUSION: We report a new type of aftercataract characterized by a liquefied, milky white substance that accumulates between the lens optic and the posterior lens capsule when the anterior capsular opening, originally created by continuous curvilinear capsulorhexis, becomes occluded with the lens optic.
Establishment and characterization of pro-B cell lines from motheaten mutant mouse defective in SHP-1 protein tyrosine phosphatase.
Mice homozygous for the motheaten (Hcph(me)) mutation lack a functional SHP-1 protein tyrosine phosphatase, show severe immunologic dysregulation and die at an early age. Severe pneumonitis in me/me mice is associated with abnormal proliferation of macrophages and granulocytes. Overgrowth of macrophages in long term cultures of me/me bone marrow has prevented analyses of lymphopoiesis in vitro. To establish hematopoietic cell lines from me/me mice, we cultured me/me bone marrow with the PA6 stromal cell line in the presence of antagonistic antibody against the receptor (c-Fms) for macrophage colony stimulating factor (M-CSF). In these cultures, overgrowth of M-CSF-dependent macrophages was suppressed by the antagonistic antibody and other hemopoietic cell lineages were generated efficiently from me/me bone marrow. By using this culture system, we established me/me pro-B cell clones (MEBs) with rearranged DH-JH but not VH-DJH. The growth of MEB clones required IL-7 and c-Kit ligand, corresponding to normal pro-B cells which express SHP-1. MEB cells were sensitive to starvation by either IL-7 or c-Kit ligand, resulting in apoptotic death. The present culture system, which supports hematopoiesis of me/me bone marrow, provides useful tools for the determination of the role of SHP-1 in signal transduction of B lymphopoiesis.
New classification of capsular block syndrome.
PURPOSE: To propose a new classification of capsular block syndrome (CBS) to improve understanding of the etiology and provide effective treatment. SETTING: Shohzankai Medical Foundation, Miyake Eye Hospital, Nagoya, and Japanese Red Cross Society, Wakayama Medical Center, Wakayama, Japan. METHODS: Three groups of eyes with CBS were reviewed: eyes originally reported and diagnosed as having CBS; eyes experiencing CBS after hydrodissection and luxation of the lens nucleus; and eyes with CBS accompanying liquefied aftercataract or capsulorhexis-related lacteocrumenasia. RESULTS: In all 3 groups, the CBS occurred in eyes with a continuous curvilinear capsulorhexis (CCC). It was characterized by accumulation of a liquefied substance within a closed chamber inside the capsular bag, formed because the lens nucleus or the posterior chamber intraocular lens (IOL) optic occluded the anterior capsular opening created by the CCC. Depending on the time of onset, CBS can be classified as intraoperative (CBS seen at the time of lens luxation following hydrodissection), early postoperative (original CBS), and late postoperative (CBS with liquefied aftercataract or lacteocrumenasia). The etiology of the accumulated substance and the method of treatment are different in each type. CONCLUSION: Capsular block syndrome is a complication of cataract/IOL surgery that can occur during and after surgery. Correctly identifying the type of CBS is crucial to understanding the nature and effective treatment of this disorder.
Improved methods of HIV vector mediated gene transfer.
HIV vectors are capable of targeted gene transfer into CD4+ cells. However, extensive testing of HIV vectors in gene therapy applications is hampered by the low titer of current HIV vector could be concentrated by approximately 20 times by sulfonated cellulose column chromatography. No replication competent cytopathic HIV was detected in the concentrated vector preparation. When the vector preparation and the target cells were centrifuged at transduction, about a five-fold increase in the apparent titer was achieved. Accordingly, by combining these two techniques the overall titer was increased by approximately two orders of magnitude. Using this high efficiency strategy, we transduced human primary lymphocytes that are refractory to transduction with currently available viral vectors. Amplification and sequencing of the integration sites showed that HIV vectors could stably integrate into the chromosomes of CD4 enriched human peripheral blood mononuclear cells. These findings indicate that HIV vectors are useful for the development of gene therapy targeting lymphocytes.
Production of emotional facial expressions in European American, Japanese, and Chinese infants.
European American, Japanese, and Chinese 11-month-olds participated in emotion-inducing laboratory procedures. Facial responses were scored with BabyFACS, an anatomically based coding system. Overall, Chinese infants were less expressive than European American and Japanese infants. On measures of smiling and crying, Chinese infants scored lower than European American infants, whereas Japanese infants were similar to the European American infants or fell between the two other groups. Results suggest that differences in expressivity between European American and Chinese infants are more robust than those between European American and Japanese infants and that Chinese and Japanese infants can differ significantly. Cross-cultural differences were also found for some specific brow, cheek, and midface facial actions (e.g., brows lowered). These are discussed in terms of current controversies about infant affective facial expressions.