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Biomedical subjects

S Fujikawa

Publications and source records attributed to S Fujikawa.

At least 73 records · Page 4Linked to original sources
PubMed1994

Ultrastructure of IVM-IVF bovine blastocysts vitrified after equilibration in glycerol 1,2-propanediol using 2-step and 16-step procedures.

Two experiments were conducted to investigate the relationship between survival rates and ultrastructural appearance, using the freeze-replica technique, of bovine blastocysts after vitrification. In experiment 1, blastocysts obtained from in vitro-matured and in vitro-fertilized (IVM-IVF) bovine oocytes were either equilibrated in a stepwise manner in a vitrification solution (VS; 22.5% glycerol + 22.5% 1,2-propanediol) using 16 steps for 18 min in total (the 16-step method) or equilibrated with 10% glycerol + 20% 1,2-propanediol for 10 min and then exposed to VS (the 2-step method). The blastocysts were then vitrified by plunging them into liquid nitrogen. All samples were subsequently thawed in a water bath at 37 degrees C and cultured in vitro with a monolayer of cumulus cells. The survival rate obtained for blastocysts equilibrated by the 16-step method was 83.3% (25/30). In contrast, no blastocysts survived by the 2-step method (0/30). In experiment 2, freeze-replica observations were carried out on blastocysts vitrified by the 16-step method and the 2-step method. In all the blastocysts, no ice crystals were observed in the cytoplasm, blastocoelic cavity, or extracellular areas, which confirmed the occurrence of complete vitrification. Little ultrastructural change was observed in the plasma membrane of the blastocysts equilibrated by the 16-step method. In contrast, small vesicles and distinct intramembrane particle (IMP) aggregation were frequently observed in the plasma membranes of blastocysts equilibrated by the 2-step method. These results indicate that the successful cryopreservation of blastocysts following the 16-step equilibration requires not only complete vitrification, but also minimization of ultrastructural damage to the plasma membrane.

Animals↗
PubMed1993

Effect of the composition of vitrification media on survival of rabbit embryos.

A total of 448 rabbit morula stage embryos were used to examine the effect of modified vitrification procedure and vitrification media containing 10% (1.36 M) glycerol, 20% (2.72 M) 1,2-propanediol, and 1 M sucrose. The best result, 89.5% embryos developed in vitro, was obtained after equilibration, vitrification, and dilution of embryos using media in which the salt concentration was maintained constant on a molar basis. Media prepared on a molal basis were more toxic and/or less efficient.

Animals↗
PubMed1993

Non-steroidal anti-inflammatory drugs and slow-acting anti-rheumatic drugs in juvenile rheumatoid arthritis.

The preferred drugs for the initial treatment of juvenile rheumatoid arthritis (JRA) are salicylates or other non-steroidal anti-inflammatory drugs (NSAID) such as tolmetin or naproxen. If the disease activity does not respond adequately to the treatment, slow-acting anti-rheumatic drugs (SAARD) such as oral gold agents, low-dose D-penicillamine, or sulfasalazine should be given in addition to NSAID. If the systemic manifestations are severe, corticosteroid therapy may be commenced. Furthermore, if the joint destruction is progressive, immunosuppressants such as methotrexate would be selected as the third-line drugs of choice. The safety and efficacy of SAARD and immunosuppressants for the treatment of children with JRA, however, have not yet been confirmed, as the adverse effects such as bone marrow suppression, oncogenicity and mutagenicity are sometimes intense. Consequently, the strict indications for use and new therapeutic concepts for the management of JRA based on its pathogenesis are required.

Adult↗
PubMed1992

Detection of antibodies against streptococcal peptidoglycan and the peptide subunit (synthetic tetra-D-alanyl-bovine serum albumin complex) in rheumatic-diseases.

Serum antibodies reactive with streptococcal cell wall peptidoglycan (PG) and its peptide subunit (synthetic tetra-D-alanine) were measured by enzyme-linked immunosorbent assay (ELISA) in patients with rheumatoid arthritis (RA), juvenile rheumatoid arthritis (JRA), osteoarthritis and acute rheumatic fever (RF) compared with healthy subjects. Using 'checkerboard' titrations, anti-PG antibody in human serum was detected at a concentration of PG antigen at 10 micrograms per well with serum dilutions of 1:1,000. For measurement of anti-tetra-D-alanine antibody, the antigen, (D-Ala4)31 was used at 0.5 micrograms per well and sera were diluted to 1:200. When the IgG antibody levels to the PG and the tetra-D-alanine of the sera of patients with RA, JRA and RF were compared with sera from healthy subjects, the sera of the patients had significantly higher levels than did healthy subjects. Antibody that reacted with the PG in serum was absorbed with purified group-specific C-carbohydrate (A-CHO), but A-CHO was not capable of absorbing anti-(D-Ala4)31 antibodies. Therefore, the peptide subunit should be used as antigen in order to measure the specific antibody to PG. Both anti-PG and anti-tetra-D-alanine antibody in human sera primarily belonged to the IgG2 subclass.

Adolescent↗
PubMed1992

Successful cryopreservation of mouse blastocysts using a new vitrification solution.

Mouse blastocysts were exposed to solutions containing four concentrations (10, 20, 30 and 40% v/v) of six permeating cryoprotectants (glycerol, ethylene glycol, propylene glycol, dimethyl sulfoxide, 1,3-butanediol and 2,3-butanediol) in phosphate-buffered saline (PBS) with calf serum (CS) at room temperature (20-22 degrees C). Blastocysts were exposed to these solutions for various periods, diluted into PBS plus CS with or without 1 mol trehalose l-1 solution and their subsequent survival in vitro was examined. Two-way anova showed a significant interaction (P < 0.01) between cryoprotectant type, concentration of cryoprotectant and method of dilution. However, no significant interaction was observed between cryoprotectant type and duration of exposure. Results suggest that cryoprotectant-induced injury to nonfrozen blastocysts is variable and depends on the cryoprotectant used. On the basis of toxicity assays, ethylene glycol was the least harmful and was combined with dimethyl sulfoxide and 1,3-butanediol to produce a new vitrification solution. Mouse blastocysts were successfully cryopreserved using a vitrification solution (designated as VSv) consisting of 20% ethylene glycol, 20% dimethyl sulfoxide and 10% 1,3-butanediol (v/v). Embryos were equilibrated in two steps, first in an equilibration solution (designated as ESv: 10% ethylene glycol, 10% dimethyl sulfoxide and 5% 1,3-butanediol; v/v) and then to VSv or one-step in VSv at different exposure times at room temperature, and then vitrified by direct plunging into liquid nitrogen. High developmental rates were obtained in vitro when the embryos were exposed to ESv and VSv for 3 and 0.5 min, respectively (96.2%) or exposed to VSv for 0.5 min (95.4%). Prolonged exposure time proved detrimental to subsequent embryo development in vitro. When vitrified warmed embryos were transferred immediately to pseudopregnant recipients, the rate of development to normal fetuses did not significantly differ from that of the nonvitrified control (two-step, 54.2 and one-step, 45.0 versus 60.0%, P > 0.05). These results suggest that the simple vitrification solution described in this study is effective for the cryopreservation of mouse blastocysts.

Analysis of Variance↗
PubMed1992

[Clinical pictures of juvenile rheumatoid arthritis].

Juvenile rheumatoid arthritis is a clinical syndrome of primary chronic arthritis in childhood. JRA is subdivided into three subtypes according to the clinical picture within six months of the onset of the disease. The clinical picture of systemic onset type usually starts with a characteristic spiking fever. Children with this onset type, sometimes have pleursy, percarditis, myocarditis, generalyzed lymphnode swelling, hepatosplenomegaly and rheumatoid rash, but arthritis may not appear within the first few months. Children with polyarticular onset type, joint manifestations are similar to that of the rheumatoid arthritis of the adult. In patients with the pauciarticular onset type, the prognosis of arthritis is relatively fair compared with the other two types, but the doctor must always be aware of the complication of chronic and recurrent uveitis which sometimes develop to glaucoma, without subjective signs.

Adolescent↗
PubMed1990

Ultrastructural differences in junctional intercellular communication between highly and weakly metastatic clones derived from rat mammary carcinoma.

We examined by electron microscopy the differences in junctional intercellular communications among highly metastatic clones, weakly metastatic clones, and the parent clone obtained from a spontaneously developed rat mammary carcinoma. We also investigated intercellular communications of the highly and weakly metastatic clone cells with normal fibroblasts. The results showed that ultrastructural changes of the highly metastatic clone cells, such as microvilli, microfilaments, and small organelles including endoplasmic reticulum, Golgi apparatus, and mucous particles, were more distinct than those of the weakly metastatic clone cells, and that the numbers of desmosome and gap junctions of weakly metastatic clone cells were significantly greater than those of highly metastatic clone cells. The formation of gap junctions and desmosomes was found only between weakly metastatic clone cells and normal fibroblasts. When both highly and weakly metastatic clone cells were cultured with normal fibroblasts, a tight junction was observed only in the culture of weakly metastatic clone cells and normal fibroblasts. These results suggest that ultrastructural differences are related to the proliferation and detachment of tumor cells from the primary site in the initial stage of tumor metastasis.

Animals↗
PubMed1989

Practices and attitudes related to hearing: a survey of executives.

Executives were surveyed about their hearing health-care practices and attitudes toward hearing loss (N = 140, mean age = 49, number of males = 133). In regard to hearing health-care practices, about one-third of the executives had not had a hearing test during the past 5 years. Fifty-one percent of the executives reported that a hearing test was conducted or recommended during their annual physical examinations. Twenty (14%) of the executives rated their hearing as fair or poor, but only two of them wore hearing aids. Executives who reported poorer hearing were less likely to have had recent hearing tests. When seeking a hearing evaluation, the executives indicated a two-to-one preference for medical doctors over audiologists--none preferred hearing aid dispensers. Regarding attitudes, approximately 90% of the executives felt that hearing aids were effective, but only two-thirds disagreed with the stereotype that hearing aids connote old age. Executives who tended to equate hearing aids with old age were less likely to be aware of hearing-impaired employees in their companies. Implications of these findings are discussed.

Administrative Personnel↗
PubMed1988

Streptococcal antibody: as an indicator of tonsillectomy.

The significance of antibody for streptolysin-O concerning tonsillectomy was studied. The results obtained were as follows. 1. The upper limit of ASO titer in 5,121 school children was 250 u and a value of more than 333 u was considered abnormal. But the level of the normal limit was different from year to year. 2. Among 143 cases with a high ASO titer of more than 833 u, only 12 cases had recurrent tonsillitis. There was no correlation between the tonsillar hypertrophy and the height of streptococcal antibodies. 3. There was a correlation between the titers determined by ELISA IgG-ASO and ASO in Todd units (r = 0.69), but there was no agreement between the titers determined by ELISA IgM-ASO and ASO in Todd units. 4. IgM-ASO determined by ELISA showed high levels in cases with early stages of streptococcal infection, focal infection and streptococcal carriers. Cases with high ASO, both IgG- and IgM-subclasses, were considered to have an indicative factor for tonsillectomy.

Acute Disease↗
PubMed1987

Ultrastructural preservation of plasma membranes by non-lethal slow freezing to liquid nitrogen temperature.

Secondary hyphae of Lyophyllum ulmarium were shown to tolerate slow freezing, which allowed extracellular freezing, to -196 degrees C. A freeze-fracture study showed that under this non-lethal freezing condition, the plasma membrane of the secondary hyphae did not show any ultrastructural changes as compared with the control, except gross cellular shrinkage. Tertiary hyphae of Lyophyllum ulmarium, on the other hand, were completely injured by slow freezing to -196 degrees C, and the plasma membrane showed distinct intramembrane particle aggregation as a result of direct membrane contact caused by severe cellular deformation. It is suggested that the absence of freezing injury in the secondary hyphae was due to ultrastructural preservation of the plasma membrane, which resulted from avoidance of severe cellular deformation, while occurrence of freezing injury in the tertiary hyphae is considered to be due to ultrastructural changes in the plasma membrane caused by severe cellular deformation.

Cell Membrane↗