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Biomedical subjects

Y Aihara

Publications and source records attributed to Y Aihara.

At least 73 records · Page 4Linked to original sources
PubMed1998

A pharmacological and HPLC analysis of the excitatory transmitter of the cardiac ganglion in the heart of the isopod crustacean Bathynomus doederleini.

In crustacean neurogenic hearts, the myocardium contracts under the tight control of rhythmically active neurons of the cardiac ganglion located inside the heart. We demonstrated that the myocardium of Bathynomus doederleini was sensitive to glutamate, quisqualate, and kainate, and that the tension of myocardial cells developed in a dose-dependent manner. The threshold concentrations were 10(-5) M for quisqualate, 10(-4) M for glutamate, and 3 x 10(-4) M for kainate. Concanavalin A, known to prevent desensitization of glutamate receptors at crustacean neuromuscular junctions, augmented excitatory junctional potentials evoked by the cardiac ganglionic neurons in myocardial cells. Using a high performance liquid chromatography (HPLC), we analyzed glutamate in extracts of the cardiac ganglion and myocardium. We obtained values for glutamate concentrations, 8741.2 +/- 184.2 and 678.2 +/- 10.7 pmol/mg, respectively. Although we attempted to measure monoamines in the extracts by HPLC, these were not detected at measurable (more than 1 fmol per 10-microL sample) levels. In conclusion, myocardial cells in isopod crustaceans were suggested to receive glutamatergic motor innervation.

Animals↗
PubMed1998

[Clinical analysis of 11 cases of juvenile dermatomyositis and polymyositis].

Juvenile dermatomyositis (JDM) is characterized by microvasculopathy of the striated muscle, which indicates different etiology, clinical manifestation and prognosis from the adult-onset dermatomyositis. We experienced 10 cases of JDM and 1 case of juvenile polymyositis (JPM) in the recent 14 years, and analyzed clinical manifestation, laboratory findings, treatment anrognosis. The cases were 9 girls and 2 boys. The onset of the disease was 2 years of age in 2 patients, and 9 to 13 years of age in 9 patients. During the follow-up courses, no cases were dead or complicated with neoplasm. Skin rash was the most frequent manifestation at the onset, and facial erythema was common. Muscle weakness was observed only in 4 cases at the onset, and in all cases muscle enzymes including creatine kinase and aldolase were elevated. The clinical course was classified into three groups; monocyclic (5 cases), chronic and recurrent (4 cases), and fulminant (2 cases). Prognosis depended not on the degree of the elevated serum muscle enzymes, but on the initial therapy employed at the onset of the disease. Five cases including 2 cases of fulminant type were initially treated with methylprednisolon pulse therapy, and all of these had no recurrence. On the other hand, 6 cases were started the therapy with p.o. prednisolone. Four of them had frequent recurrences in accordance with tapering of prednisolone. These cases were effectively treated with the combination with immunosuppressants. In previous reports, JDM and JPM were reported to be a disorder which had relatively favorable prognosis. But we found that one third of the cases had chronic and recurrent courses. Methylprednisolone pulses as initial therapy may be effective in preventing the chronicity and recurrence of the disease.

Adolescent↗
PubMed1998

[Buckwheat allergy in 90,000 school children in Yokohama].

Hypersensitivity to buckwheat allergen frequently causes anaphylactic type reactions including urticaria, wheezing, dyspnea and/or shock. Though the susceptible pupil would be recommended to be careful for school lunch and picnic meals, the prevalence of buckwheat allergy in school children has not yet been elucidated. In this study, data on the children allergic to buckwheat were collected by sending questionnaire to 341 nurses in elementary school in Yokohama. Among the total subjects of this investigation, 92,680 children, the incidence of buckwheat allergy was determined 0.22% (140 boys and 54 girls). This percentage was not so low level besides the prevalence of such allergic diseases as bronchial asthma, atopic dermatitis, allergic rhinitis, allergic conjunctivitis and food allergy was 5.6%, 4.2%, 3.1%, 1.6%, and 1.3%, respectively. Although a large majority of clinical symptoms of buckwheat allergy were urticaria (37.3%), skin itching (33.3%), and wheezing (26.5%). Four children (3.9%) experienced anaphylactic shock having a need of medical emergency treatment. The incidence of anaphylactic shock due to buckwheat was higher than those due to egg and milk allergy. Actually 7 pupil was provoked allergic reaction by buckwheat noodle served at school lunch, and 1 pupil at picnic meals. Thus, school children allergic to buckwheat is not rare, and it is important to withdraw buckwheat food from school lunch and picnic meals.

Age Factors↗
PubMed1997

Effects of liposteroid on skin lesions in autoimmune MRLlpr/lpr mice.

Dexamethasone palmitate (D-PAL) incorporated into lipid microspheres (D-PAL emulsion) is taken up by the reticuloendothelial system and by some inflammatory cells. Therefore, it has a stronger anti-inflammatory activity than free corticosteroids in vivo. To study the effect of D-PAL emulsion on systemic lupus erythematosus (SLE), we administered D-PAL emulsion to MRLlpr/lpr mice, an animal model for human SLE. The effect of D-PAL emulsion was compared with that of methylprednisolone (m-PSL), a water-soluble steroid. Percent survival was higher in the group treated with 0.25 mg of D-PAL emulsion intravenously once every 4 weeks than in those groups treated similarly with m-PSL or PBS control. Swelling of lymph nodes was frequent in the group treated with m-PSL or with PBS, while rarely observed in the group treated with D-PAL emulsion. Proteinuria was more frequent in the groups treated with m-PSL or PBS than in the group treated with D-PAL emulsion. Although the frequency of skin lesions was not different between these three groups, the control and m-PSL treated mice had severe skin lesions, such as hair loss of erythematous skin with scales and crusts at the nape, while D-PAL emulsion treated animals showed only facial alopecia without inflammatory skin changes. These data demonstrate that D-PAL emulsion was more effective than a corresponding dose of m-PSL on autoimmune prone mice. This suggests that intermittent administration of D-PAL emulsion may be effective in the treatment of human SLE.

Animals↗
PubMed1997

Mixed connective tissue disease in childhood: a nationwide retrospective study in Japan.

Sixty-six children with mixed connective tissue disease (MCTD) were analyzed by a nationwide prospective study. The diagnostic significance of Raynaud's phenomenon and positive anti-RNP antibody was confirmed, and additional symptoms including swelling of fingers, facial erythema, and polyarthralgia, and laboratory findings such as positive rheumatoid factor, hypergammaglobulinemia, and increased levels of myogenic enzymes, were variably positive. These clinical and laboratory characteristics of MCTD were critically different from those of systemic lupus erythematosus, indicating that MCTD is an independent entity of disease.

Adolescent↗
PubMed1997

[Analysis of children with tuberculosis in the past 20 years].

To characterize the clinical features of childhood tuberculosis, we analyzed the symptoms, signs, and laboratory findings of the 89 children with tuberculosis admitted to the Yokohama City University Hospital from 1975 to 1994. Compared with the numbers of patients admitted from 1975 to 1979, those of patients of the past 5 years (from 1990 to 1994) were reduced by half. Of the 89 subjects, 56.2% were below 3 years of age and 24.7% were under 1 year of age. 51.7% had primary complex and 20.2% had serious tuberculosis (tuberculous meningitis 14.6%, miliary tuberculosis 3.4%, and bone and joint tuberculosis 2.2%). Tuberculous children below 3 years of age consisted of primary complex (60.0%) and serious tuberculosis (32.0%). The majority (86.0%) of tuberculous children below 3 years of age had not received BCG vaccination. In 55 (61.8%) of 89 subjects, the sources of tuberculosis were clarified. Of these subjects, 83.6% were infected in the family. The rate of BCG inocluation tended to decrease with decreasing age, especially that of children below 3 years of age was 14.0%. Of the 89 subjects, only 16.9% proved to be smear-positive. Taken together, in order to eliminate tuberculous children below 3 years of age, the following is necessary; (1) BCG inoculation in early infancy, (2) early diagnosis of index cases with adult tuberculosis, and (3) prompt and appropriate family contact examination.

Adolescent↗
PubMed1997

A pediatric case of polymyositis associated with Mycoplasma pneumoniae infection.

We describe the case of a 10-year-old girl who developed polymyositis associated with a Mycoplasma pneumoniae infection. She exhibited mild muscle weakness without skin rash, markedly elevated serum levels of muscle enzymes, and infiltration of mononuclear cells in a muscle biopsy specimen. Efficacy of both oral prednisolone and of intravenous methylprednisolone pulse therapy for her disease was limited. However, other immunosuppressive drugs, cyclophosphamide and methotrexate, proved clinically effective. This is the first report of steroid-resistant polymyositis associated with M. pneumoniae infection in a child.

Anti-Inflammatory Agents↗
PubMed1997

[A case of macrophage activation syndrome developed with systemic juvenile rheumatoid arthritis].

We reported a child of macrophage activation syndrome (MAS) associated with the course of systemic juvenile rheumatoid arthritis (sJRA). The clinical and laboratory findings in our case was ascribed to the overproduced inflammatory cytokines especially TNF-alpha by activated macrophages. Moreover, macrophage-colony stimulating factor (M-CSF) was also elevated in the active phase of the disease, and decreased in the convalescent phase, indicating that M-CSF can be the most potent stimulator of macrophages to produce inflammatory cytokines. Cyclosporine A along with plasmaexchange and corticosteroid, instead of VP16 or other immunosuppresive agents, was effecting in the management of this severe, life-threatening MAS.

Anemia↗
PubMed1997

Destruction of hematopoietic microenvironment by cytotoxic T cells.

Coculture of cytotoxic T cells (STIL-3 C5) derived from L8313 leukemic mice with hematopoietic supportive stromal cells (MS-5) resulted in the detachment of MS-5 cells from the culture dish, whereas helper T cells (STIL-3 DF) did not induce this detachment. The response of bone marrow (BM) adherent cells to the same treatment was similar to that of MS-5 cells. The detached cells were unable to proliferate further, and genomic DNA of these cells showed fragmentation, suggesting that hematopoietic stromal cells died of apoptosis. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed that STIL-3 C5 cells, but not STIL-3 DF cells expressed perforin, granzyme A & B, and Fas ligand. Fas was expressed in MS-5, BM adherent cells, MS-K and NIH/3T3 cells, which do not support hematopoiesis. These data suggest that the aforementioned factors mediate induction of apoptosis in MS-5 cells induced by direct cell-to-cell interaction with STIL-3 C5. This may explain the mechanism responsible for the destruction of the hematopoietic microenvironment by cytotoxic T cells in L8313 leukemia, from which STIL-3 cells are derived; it also suggests that destruction of hematopoietic tissue may be caused by leukemic cytotoxic T cells in some cases of leukemia.

Animals↗
PubMed1996

Toxoplasma gondii: experimental infection in cats vaccinated with 60Co-irradiated tachyzoites.

The effects of 60Co-irradiation on the viability and immunogenicity of RH and Beverley strains of Toxoplasma gondii was examined. While 60Co-irradiated tachyzoites retained invasive activity in mouse embryonal cells and sustained antigenicity in mouse peritoneal macrophages, the parasites did not develop in host cells. Vaccination of mice with 60Co-irradiated tachyzoites of either RH or Beverley strains induced resistance to challenge with a highly virulent strain (RH strain). Vaccination of kittens with 60Co-irradiated tachyzoites of the Beverley strain partially prevented oocyst shedding when challenged with cysts (bradyzoites) from the Beverley strain. But kittens vaccinated with 60Co-irradiated or fixed tachyzoites of the RH strain shed oocysts when challenged with cysts (bradyzoites) from the Beverley strain. These results suggest that the development of protective immunity in feline toxoplasmosis seems to be strain and/or stage-specific.

Animals↗
PubMed1996

Age-related decrease in responsiveness to L-DOPA is not due to changes in dopamine receptor mRNAs or G protein mRNAs.

To clarify the cause of the age-related decrease in the responsiveness to L-DOPA seen in parkinsonian patients, we studied age-related changes in the mRNA levels of dopamine receptors (D1, D2) and of G proteins (Gs, Gi, Go) in 22 control human brains aged 50-105 years. Neither the mRNA levels of dopamine receptors or of the G proteins changed with age. Another factor in the receptor-G protein cascade, such as guanine nucleotide binding, may cause the age-related decrease in responsiveness.

Actins↗
PubMed1996

Acute anterior uveitis in a child with HLA-B60 after Salmonella enteritis associated with the transient appearance of auto-antibody.

A Japanese girl with HLA-B60, but not B27, who developed acute anterior uveitis after Salmonella enteritis is described. There was no evidence of arthritis or urethritis during this episode. This is the first report that acute anterior uveitis after Salmonella enteritis was associated with the transient appearance of auto-antibody in the serum at an early period.

Antibodies, Antinuclear↗
PubMed1996

[Serial computed thermography for Raynaud's phenomenon of patient with progressive systemic sclerosis (PSS)].

We reported a case with progressive systemic sclerosis, a relatively rare disease in childhood. Raynaud's phenomenon (RP) of the patient was serially monitored by computed thermography for 1 year. Although clinically apparent RP manifested only in winter season, thermographical changes were documented through all season, suggesting that RP is a constitutional sign which may emerge in winter by provocation of atmosphere. Thus, we recommend to use the words, "Raynaud's phenomenon" and " Raynaud's symptom", in an appropriate meaning. RP of the patient, however, varied depending on the time determined, which indicated that the cause of RP is not due to the irreversible tissue degenerations, but due to the reversible functional factors. Computed thermography was proved useful for detecting RP objectively, and will be valuable for estimating the effects of medications for RP.

Adult↗
PubMed1996

[Immunologic analysis of milk, hen egg, and soybean proteins in butter and margarine, and clinical assessment for availability of hypoallergenic margarine (HAM)].

To determine the allergenic proteins in commercially available butter and margarine, protein fractions were extracted and immunologically analyzed against milk, hen egg, and soybean antigens. Butter and 10 kinds of margarine were proved to contain these proteins in various concentrations by ELISA and immunoblotting methods by use of the rabbit antisera developed against each food proteins. However, hypoallergenic margarine was found to contain no such proteins at all. Using sera obtained from atopic dermatitis patients, previously detected high levels of IgE antibodies to milk, hen egg, or soybeans, the extracted protein fraction from butter and margarine was analyzed whether these proteins react with IgG antibodies in patients' sera. The sera with high levels of specific IgE recognized protein antigens in these extracts except those from hypoallergenic margarine, suggesting that proteins in butter and margarine may become allergenic for the patients sensitive to the proteins, and that hypoallergenic margarine will be a reasonable alternative for the allergic patients to milk, hen egg, or soybeans.

Adolescent↗
PubMed1995

[A case of tuberculous meningitis followed by tuberculoma with pan-hypopituitarism].

We reported a case who suffered from tuberculous meningitis at 10 months of age, and progressed to basal tuberculoma despite intensive drug therapy with isoniazid, rifampin, and streptomycin. Pan-hypopituitaliam due to basal tuberculoma was effectively replaced by the administration of anti-diuretic hormone (DDAVP) and levothyroxine sodium. Basal tuberculoma was finally removed by surgical operation. Histopathological examination of the tuberculoma revealed Mycobacterium tuberculosis and Langhans giant cells. During the 6 years after the operation, her growth rate was found to be retarded, and the administration of human growth hormone was started. Remarkable catch-up growth was demonstrated. We like to emphasize that infantile tuberculosis, mostly a result of intafamilial transmission, may manifest meningitis in the early phase of the disease, and it sometimes progresses to basal tuberculoma unresponsive to anti-mycobacterial drug therapy.

Child↗
PubMed1995

Separate control of the survival, the self-renewal and the differentiation of hemopoietic stem cells.

Hemopoietic stem cells adhere to hemopoietic supportive (MS-5) cells, but not to non-supportive (MS-K) cells. Although a soluble stem cell factor (SCF) was produced by both of these cell lines, little activity was detectable in the supernatant from the cultures of either of these cells, indicating that SCF might be compartmentalized within the extracellular matrix (ECM), and transferred directly to the stem cells via the ECM (44). To probe this possibility, we studied the transfer of SCF from the ECM and the subsequent support of the survival of the hemopoietic stem cells. A stem cell-enriched bone marrow cell fraction was overlaid on SCF-containing ECM. The stem cells survived and proliferated for some days without differentiation under these conditions, whereas stem cells overlaid on ECM without SCF died within a few days. Addition of interleukin-3 (IL-3) to the ECM that contains SCF, induced differentiation of the stem cells. Granulocyte-macrophage colony-stimulating factor (GM-CSF) induced further differentiation of the stem cells, which was accompanied by a decrease in the number of colony-forming unit in spleen (CFU-S). These observations verified the above hypothesis, and indicated that the survival, the self-renewal, and the differentiation of hemopoietic stem cells can be separately controlled at least in vitro.

Animals↗