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Biomedical subjects

Y Fukazawa

Publications and source records attributed to Y Fukazawa.

At least 37 records · Page 2Linked to original sources
PubMed1996

Apoptosis in adult mouse testis induced by experimental cryptorchidism.

Induction of cryptorchidism in the mouse causes infertility due to disruption of spermatogenesis including reduction of germ cells; however, the cellular mechanism responsible for the degenerative changes in cryptorchid testis is still unclear. In surgically induced bilateral cryptorchidism of 3-month-old C57BL/Tw mice, cellular changes in the cryptorchid testis were studied 1, 2, 3, 7, 14 and 21 days after the operation by electron microscopy, DNA fragmentation, in situ 3'-end labeling, serum and testicular testosterone measurements and gene expression. Although the testis showed DNA fragmentation even in intact mice, the cryptorchidism increased the degree of the fragmentation at 1 postcryptorchidism (p.c.) day. Apoptosis was encountered mainly in spermatids and spermatocytes. The number of apoptotic cells in the cryptorchid testis showed a 7-fold increase at 1 p.c day as compared to the intact testis, then it gradually decreased. Serum testosterone levels showed a significant decrease at 2 p.c. days and remained low thereafter. Expression of transforming growth factor-beta 2 (TGF-beta 2), TGF-beta 3, tumor necrosis factor-alpha receptor and Fas mRNAs increased in the cryptorchid testis within 24 h after the operation. In lpr(cg) and lpr mice lacking functional Fas, gld mice lacking functional Fas ligand and lpr(cg)-gld mice lacking both functional Fas and Fas ligand, the experimental cryptorchidism also induced apoptosis in germ cells at 1 p.c. day. The present results indicate that cryptorchidism induces apoptotic dell death in germ cells, and that testosterone reduction and the Fas system may not be significantly involved in the apoptosis of male germ cells.

Animals↗
PubMed1996

Effect of estrogen on ontogenic expression of progesterone and estrogen receptors in rat uterus.

The ontogenic expression of progesterone and estrogen receptors (PR and ER) and effect of estrogen on these receptors were investigated immunohistochemically in rat uterus from the day of birth ( = 0 day) to 30 days of age. Uterine epithelial and stromal cells showed a negative PR immunoreaction at 0 day. The PR in the epithelial cell nuclei appeared by 5 days, while the stromal cells showed a negative PR reaction until 12 days. The staining of the stromal cells appeared from 12 to 15 days. In both the epithelial and stromal cells, the initiation of the PR appearance was not affected by ovariectomy performed at 0 day or 5 days prior to the appearance of PR in the epithelial and stromal cells. Estrogen injections from 0 day failed to initiate the appearance of PR in the epithelial cells, regardless of doses of estradiol-17 beta (0.1, 1 and 10 micrograms daily), but induced PR in the stromal cells. The staining of ER appeared at 5 days in the epithelial cells and at 1 day in the stromal cells, respectively. ER appeared after 2-3 daily injections of estrogen from 0 day depending upon the doses. These results suggest that steroid hormones secreted from neonatal ovary do not play any important role in ontogenic expression of PR during the postnatal uterine maturation.

Animals↗
PubMed1995

In vitro secretion of insulin-like growth factor-binding proteins from liver of striped bass, Morone saxatilis.

In vitro secretion of insulin-like growth factor-binding proteins (IGFBPs) from liver of striped bass (sb: Morone saxatilis) was studied using a simple organ-culture system. Liver cubes (1 mm3) were cultured in minimum essential medium with Earle's salts containing 0.1% bovine serum albumin and 100 U/ml penicillin in 5% CO2/95% O2 at 16 degrees. The amount of double-stranded DNA in these cultured liver cubes did not change by 192 hr in the culture, but decreased by 216 hr. Four IGFBPs (a 23- to 24-kDa protein, a 28- to 30-kDa protein, a 35- to 39-kDa protein, and an 85- to 90-kDa protein) were identified in striped bass serum by Western ligand blotting; two of these IGFBPs, 23-24 kDa (sbIGFBP-1) and 28-30 kDa (sbIGFBP-2), were consistently detected in culture media by Western ligand blot analysis. The intensity of the blot for sbIGFBP-2 was consistently greater than that of sbIGFBP-1, which was no longer secreted after 96 hr in culture. The effects of hormones and growth factors on IGFBP secretion by liver tissue were measured after 48 hr in culture. sbIGFBP-1 in the medium was significantly decreased by adding ovine prolactin (10 micrograms/ml), bovine insulin (100 micrograms/ml), and bovine IGF-I (100 ng/ml), but was increased by 17 beta-estradiol (E2: 5 and 50 ng/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Effects of sex hormones on oncogene expression in the vagina and on development of sexual dimorphism of the pelvis and anococcygeus muscle in the mouse.

Neonatal treatment of female mice with diethystilbestrol (DES) is known to induce ovary-independent persistent proliferation and cornification of vaginal epithelium. This irreversibly changed vaginal epithelium persistently expressed higher levels of c-jun and c-fos mRNAs, which was not altered by postpubertal estrogen. Sexual dimorphism was encountered in mouse pelvis and anococcygeus muscle. Postpubertal estrogen changed the shape of the pelvis to the female type and postpubertal androgen changed it to the male type. Neonatal exposure to DES and to the antiestrogen tamoxifen altered the developmental pattern of the pelvis, which contained lower concentrations of calcium and phosphorus than controls. The size of anococcygeus muscle was increased by postpubertal androgen but decreased by postpubertal estrogen. However, neonatal estrogen (DES) exposure permanently enlarged the anococcygeus muscle. Thus, neonatal treatment of mice with estrogen and antiestrogen results in irreversible changes in nonreproductive as well as reproductive structures.

Animals↗
PubMed1995

Apoptosis in thyroid tissue from patients with Hashimoto's thyroiditis.

To clarify whether apoptosis of thyroid follicular epithelial cells occurs at the tissue level in autoimmune thyroiditis, 17 specimens of thyroid tissues with Hashimoto's thyroiditis were stained for fragmented DNA. Almost all nuclei of follicular epithelial cells forming atrophic thyroid follicles surrounded by mononuclear cell infiltration and fibrosis showed positive staining. With increasing distance from lymphoid cell follicles, the percentage of follicular epithelial cells with DNA fragmentation-positive nuclei decreased (30-80%). Electron microscopic study revealed the existence of epithelial cells with shrunk and condensed nuclei. The frequency of those cells in different areas was almost compatible with that of cells with fragmentation-positive nuclei. These findings suggest that apoptosis plays an important role in the thyroid tissue injury in autoimmune thyroiditis.

Adult↗
PubMed1995

[Epidemiology of Mycobacterium tuberculosis infection based on RFLP analysis].

In Japan, the decline of the tuberculosis incidence rates has been slowed down since 1970s. To study factors influencing this slow down of the decline, we have carried out the analysis of RFLP patterns of 941 strains of M. tuberculosis which were isolated at 38 hospitals in various districts of Japan in 1992. The outline of the results is as follows; (1) Distribution of the number of IS6110: The number of the occurring IS elements varies from 1 to 19, and the majority of the isolates have 9 to 14 copies. This finding is identical to the result of the previous investigation carried out in 1987 using 123 strains of M. tuberculosis. There were groups of individuals with identical patterns among those having the same number of copies. The characteristics of the RFLP pattern variety in Japan looks like that of Africa where tuberculosis in highly prevalent. In our country, however, it is considered that the influence of elderly people is very important. Thirty-seven strains contained only one hybridizing band. In 35 of these strains the copy was observed in a 7.9 kbp fragment, and in the other two strains the copy was observed in a 1.5 kbp fragment. Isolates which contain only one or small number of copies could not be differentiated by IS6110, so that other targets for RFLP analysis such as IS1081, DR sequence, and PGRS are to be further investigated. (2) Cluster analysis was shown to be an appropriate epidemiological methodology.(ABSTRACT TRUNCATED AT 250 WORDS)

Cluster Analysis↗
PubMed1994

A new biomaterial, hen egg shell membrane, to eliminate heavy metal ion from their dilute waste solution.

The egg shell membrane (ESM) is an intricate lattice network of stable and water-insoluble fibers with high surface area. ESM accumulates and eliminates various heavy metal ions from dilute aqueous solution with high affinity and in short contact time, depending on pH and characteristics of the individual ion. Under certain conditions, the level of precious ions, Au, Pt, and Pd accumulation approaches 55, 25, and 22% of dry wt of ESM, respectively. Also uranium uptake 30% of that of ESM. Experiments suggested that ESM is promising to use for the purpose of removal/recovery of metals and water pollution control.

Adsorption↗
PubMed1994

Antigen-specific suppression of antibody responses by T lymphocytes cytotoxic for antigen-presenting cells.

In this study we demonstrated an alternative model of the antigen (Ag)-specific suppression of antibody response in mice. Splenocytes that were taken from BALB/c mice immunized by i.v. injection of soluble human serum albumin (HSA) or ovalbumin exhibited MHC-restricted Ag-specific cytotoxicity for the respective antigen-presenting cells (APC). When HSA-primed splenocytes cultured with Ag and interleukin-2 (IL-2) were treated with anti-CD4 or anti-CD8 monoclonal antibody (mAb) plus complement, CD8+ and CD4+ T cells exhibited nearly the same level of cytotoxicity against APC. Furthermore, HSA-primed CD4+ and CD8+ T cells released the same amount of interferon-gamma (IFN-gamma) when stimulated with Ag and IL-2. Recombinant IFN-gamma was shown to suppress the in vitro plaque-forming cell (PFC) response to sheep red blood cells (SRBC) only when it was added within 24 h after addition of Ag. The supernatants from both HSA-primed CD4+ and CD8+ T cells suppressed the PFC response to SRBC in vitro, and the suppressive activity was abrogated by anti-IFN-gamma mAb, but increased by anti-IL 4 mAb. These results suggest that in our system the effector cells for Ag-specific suppression of the antibody response in mice are both the cytotoxic type 1 clones (IFN-gamma-producing) of CD4+ and CD8+ T cells for APC, and that IFN-gamma is a major extracellular effector molecule for such suppression.

Animals↗
PubMed1994

[Mucinous adenocarcinoma of the prostate. A case report and analysis of the literature].

An 80-year-old man, who had been treated for colon cancer 25 years ago, presented with gross hematuria. Rectal examination revealed a soft nodule in the right lobe. The serum prostatic specific antigen (PSA) was elevated to 5.2 ng/ml, while prostatic acid phosphate (PAP) was normal. Transrectal ultrasound revealed a hypoechoic mass in peripheral zone of the prostate and dilated seminal vesicle. A needle biopsy of the prostate showed mucinous adenocarcinoma. Under the diagnosis of prostatic tumor with seminal vesicle involvement, radical prostatectomy was performed. Histological findings showed organ confined cancer, of which most was composed of extracellular mucin lakes. Immunohistochemical study revealed the tumor cells positive for PSA and PAP. Mucinous adenocarcinoma of the prostate has been known to be clinically different from non-mucinous adenocarcinoma, in that the former is insensitive to hormonal therapy, is rarely associated with elevated PAP and rarely metastasize to the bone. But our analysis of the literatures is Japan showed no significant difference clinically between mucinous and non mucinous prostatic adenocarcinoma. However mucinous adenocarcinoma with signet ring cell rarely responds to hormonal therapy, which should not be classified to true mucinous adenocarcinoma in the current criteria. True mucinous adenocarcinoma could be a variant of prostatic adenocarcinoma, which is peripheral origin and should be treated like non-mucinous adenocarcinoma.

Acid Phosphatase↗
PubMed1994

Scanning electron microscope observation of adherence of Candida albicans to cultured keratinocytes.

The role of antigen 6 in the adherence process of Candida albicans serotype A to cultured keratinocytes was examined with a scanning electron microscope. The number of adhered organisms was significantly lower for the antigen 6-deficient mutant strain than for the antigen 6-positive parent strain (P < 0.001). Fibril- or strand-like structures bridging the organisms and the keratinocytes were found to develop during the later stages of adherence.

Bacterial Adhesion↗
PubMed1993

New method for detection of Candida albicans in human blood by polymerase chain reaction.

We developed a new method for detection of Candida albicans cells in human blood by the polymerase chain reaction that amplifies a 125-bp region within a species-specific, multiple-copy DNA fragment. In preparing template DNA from C. albicans-containing blood, the addition of C. tropicalis cells, together with antibody which reacts with both cells, raised the sensitivity of detection of C. albicans to about 3 cells per 0.1 ml.

Base Sequence↗
PubMed1993

[A case of acute pulmonary hemorrhage and positive anti-glomerular basement membrane antibody in systemic lupus erythematosus].

A 58-year-old woman was admitted with cough, dyspnea on effort and diffuse micronodular and patchy shadows on her chest roentgenograms. Two weeks later, acute pulmonary hemorrhage developed with low levels of complement and positive immune complexes. She was diagnosed as having systemic lupus erythematosus (SLE) with positive anti-nuclear antibody, positive anti-DNA antibody, biologically false positive Wassermann reaction, auto-immune hemolytic anemia and photosensitive dermatoses. In addition, anti-glomerular basement membrane antibody (anti-GBM antibody) was positive in serum, but pulmonary hemorrhage was thought to be secondary to SLE, since the renal biopsy showed lupus nephritis. Cases of SLE with positive anti-GBM antibody are seldom confirmed. It was assumed that the basement membrane of the lung or kidney was damaged first by interstitial pneumonitis due to SLE or lupus nephritis, basement membranes antigens were exposed, with secondary production of anti-GBM antibody.

Anti-Glomerular Basement Membrane Disease↗
PubMed1992

Expression of myeloid cell phenotypes by a novel adult T-cell leukemia/lymphoma cell line.

BACKGROUND: Human T-cell leukemia virus type 1 (HTLV-1) can infect a number of cells of different lineages in vitro, yet the immunophenotypes of most adult T-cell leukemia/lymphomas (ATLs) are restricted to CD4+. The apparent discrepancy between these findings is still largely unknown. PURPOSE: We report on a unique case of ATL in which the leukemia cells were positive for both T-cell and myeloid cell antigens. To characterize these cells, we isolated cell lines from this patient with ATL. METHODS: The fresh leukemia cells were cultured without the addition of interleukin-2. Cell cloning was carried out by limiting dilution. RESULTS: A cell line (MU) and its clonal sublines were established. MU cells showed the same chromosomal abnormalities and T-cell receptor beta-chain gene rearrangement pattern as those of fresh leukemia cells. MU cells were exclusively positive for a myeloid cell marker (CD13) but not for T-cell markers, despite the presence of T-cell receptor gene rearrangement. CONCLUSION: The established ATL cell line showed both T-cell and myeloid cell characteristics, which seems to be the first evidence for the close association of ATL cells with both lymphoid and myeloid features. The cell line may provide a new insight for the targets of HTLV-1 infection and transformation in vivo.

Adult↗
PubMed1992

Antigenic role of stress-induced catalase of Salmonella typhimurium in cell-mediated immunity.

The ability of the H2O2-induced catalase of Salmonella typhimurium to induce cell-mediated immunity against S. typhimurium infection in mice was examined. When exponentially growing cells of S. typhimurium were treated with 20 microM H2O2, the cells resisted killing by 1 mM H2O2 and showed the induction of a new species of catalase in addition to the constitutively produced one. Two molecules of catalases in S. typhimurium were isolated from mutant strains: H2O2-induced catalase (catalase II, 320 kDa), from a regulatory gene-deficient oxyR1 mutant, and constitutive catalase (catalase I, 350 kDa), from a katG gene-deleted mutant. When mice were inoculated with a sublethal dose of live cells, an intensive protective immunity (100% survival at 3 weeks) after challenge with a virulent strain associated with the delayed-type footpad hypersensitivity (DTH) reactions to both catalase I and catalase II was induced. Conversely, mice immunized with formalin-killed virulent S. typhimurium did not elicit protective immunity or DTH to either catalase. When mice were immunized with catalase I or catalase II, an enhanced protection (to a certain extent: 50% survival at 3 weeks) was induced in mice immunized with catalase II associated with DTH which did not cross-react with catalase I but not in those given catalase I. These results suggest that H2O2-induced stress proteins, including catalase II, are the dominant antigens for cell-mediated immunity in live cells of S. typhimurium and that a burst of such stress proteins in live salmonellae in phagocytes is responsible for the induction of cell-mediated immunity that is largely involved in the protection of susceptible mice against Salmonella infection.

Animals↗
PubMed1992

Role of specific determinants in mannan of Candida albicans serotype A in adherence to human buccal epithelial cells.

Candida albicans serotype A (C. albicans A) possesses a specific antigen, designated antigen 6, which resides in mannans on the cell surface. To determine the role of the mannan moiety of the C. albicans cell wall in adherence to buccal epithelial cells, we used antigen 6-deficient mutants which had been isolated by screening with an agglutinating monoclonal antibody against antigen 6 (MAb-6). 1H nuclear magnetic resonance spectral analysis of the purified mannans from the mutants showed a loss of the signals related to that beta-linkage of the side chains. Moreover, acetolyzed fragments of the mutant mannans showed a decreased amount of mannohexaose and mannopentaose. The mutant yeast cells exhibited significantly reduced ability to adhere both to exfoliated buccal epithelial cells and to a human buccal cell line. A number of strains of C. albicans A, C. tropicalis, and C. glabrata, all of which bear antigen 6, showed significantly higher adherence to the cell line than did those of C. albicans serotype B, which lack antigen 6. The whole mannan from the C. albicans A parent inhibited the adherence of C. albicans A to epithelial cells dose dependently, whereas mannan from a mutant strains did not. Moreover, C. albicans A treated with MAb-6 or polyclonal factor 6 serum showed reduced adherence. A close correlation was found between adhesive ability and agglutinability with MAb-6 in the C. albicans A parent, the antigenic mutants, and their spontaneous revertants. These results suggest that so far as mannan adhesion is concerned, serotype A-specific determinants are largely involved in the mechanisms of adherence of C. albicans A to human buccal epithelial cells.

Adhesiveness↗