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Biomedical subjects

Y Aihara

Publications and source records attributed to Y Aihara.

At least 19 recordsLinked to original sources
PubMed1998

Molecular cloning of rat klotho cDNA: markedly decreased expression of klotho by acute inflammatory stress.

We have recently identified a novel gene, termed klotho, that is involved in the suppression of several aging phenotypes. The gene encodes a membrane protein that shares sequence similarity with the beta-glucosidases of bacteria and plants. In this study, we isolated rat klotho cDNA and examined its tissue distribution in rats. The deduced amino acid sequence of rat Klotho protein was 1014 amino acids in length and 94 and 85% homologous to those of mouse and human Klotho proteins, respectively. Northern blot analysis using the rat klotho cDNA probe identified a single transcript of 5.2 kb in size expressed predominantly in the kidney, while RT-PCR detected low levels of expression also in the brain, lung, intestine, and ovaries. During development, klotho expression in the kidney was markedly augmented after birth. Chromosomal localization of rat klotho was mapped to 12q12. Northern blot analysis showed that expression of klotho was markedly decreased by lipopolysaccharide (LPS) in vivo, suggesting that expression of klotho is affected by acute inflammatory stress. The present study leads to a better understanding of the physiologic and pathophysiologic roles of Klotho.

Amino Acid Sequence↗
PubMed1998

Dynamics of human cardiorespiratory responses to standing on one leg with eyes closed.

The postural control system has been extensively studied in terms of somatic motor function but little is known about its connection with human autonomic function. The purpose of this study was to determine the cardiorespiratory changes in response to the 1-min balance test that was performed by standing on one leg with eyes closed (SOLEC) or eyes open (SOLEO) in 12 healthy young women [mean age 20.7 (SD 3.3) years]. Heart rate (HR), respiratory rate (RR), duration of inspiration and expiration, tidal volume (VT), and oxygen uptake (VO2) were measured during the test. The SOLEC test produced rapid increases in HR at the onset. There were significant increases in HR later during the test (P < 0.05). Metabolic rate (VO2) showed a gradual increase during the SOLEC test, indicating that the late responses could have been partly due to metabolic changes. The RR increased significantly at the onset of the test (P < 0.05), and remained elevated until the end of the test. The early responses were considered to be mediated neurally through the postural control system which receives the afferent inputs arising from the vestibular system and from muscle proprioceptors of the leg. In contrast, SOLEO caused small insignificant changes in HR, RR, VT and VO2, suggesting that a visual input is essential for balancing a postural change. The SOLEC test may have potential as a test of autonomic function.

Adolescent↗
PubMed1998

The effect of exposure to negative air ions on the recovery of physiological responses after moderate endurance exercise.

This study examined the effects of negative air ion exposure on the human cardiovascular and endocrine systems during rest and during the recovery period following moderate endurance exercise. Ten healthy adult men were studied in the presence (8,000-10,000 cm-3) or absence (200-400 cm-3) of negative air ions (25 degrees C, 50% humidity) after 1 h of exercise. The level of exercise was adjusted to represent a 50-60% load compared with the subjects' maximal oxygen uptake, which was determined using a bicycle ergometer in an unmodified environment (22-23 degrees C, 30-35% humidity, 200-400 negative air ions.cm-3). The diastolic blood pressure (DBP) values during the recovery period were significantly lower in the presence of negative ions than in their absence. The plasma levels of serotonin (5-HT) and dopamine (DA) were significantly lower in the presence of negative ions than in their absence. These results demonstrated that exposure to negative air ions produced a slow recovery of DBP and decreases in the levels of 5-HT and DA in the recovery period after moderate endurance exercise. 5-HT is thought to have contributed to the slow recovery of DBP.

Adult↗
PubMed1998

Recombinant IFN-gamma treatment of a patient with hyperimmunoglobulin E syndrome triggered autoimmune thrombocytopenia.

We report a pediatric patient with hyperimmunoglobulin E syndrome (HIES) treated with recombinant IFN-gamma (rIFN-gamma) for 2 1/4 years who developed autoimmune thrombocytopenia and was positive for serum antiplatelet antibody and antinuclear antibody (ANA). She was then treated with i.v. methylprednisolone pulse therapy followed by oral immunosuppressive drugs. With this therapy, her platelet count increased and was maintained within the normal range for more than a year. We retrospectively examined her sera stored at -40 degrees C for ANA and found that the ANA level was increased from 1:40 to 1:640 with the rIFN-y therapy. Therefore, we believe that, in this case, rIFN-y treatment may have played a crucial role in triggering autoimmune thrombocytopenia. Furthermore, this case demonstrates that caution must be observed in administering rIFN-gamma to genetically predisposed patients.

Antibodies, Antinuclear↗
PubMed1998

Epidemiological study of a food-borne outbreak of enterotoxigenic Escherichia coli O25:NM by pulsed-field gel electrophoresis and randomly amplified polymorphic DNA analysis.

This study investigated the applicability of molecular epidemiological techniques to the identification of the causal agent of an outbreak of diarrhea caused by ingestion of food contaminated with enterotoxigenic Escherichia coli (ETEC). The outbreak occurred at four elementary schools in July 1996 and affected more than 800 people. Illness was most strongly associated with eating tuna paste (relative risk, 1.79; 95% confidence interval = 1.16 to 2.79; P = 0.0001). To evaluate the epidemiological characteristics of the pathogen, the DNAs from numerous isolated ETEC strains were subjected to randomly amplified polymorphic DNA analysis, pulsed-field gel electrophoresis of nuclease S1-treated plasmid DNA, and analysis of genomic DNA restriction fragment length polymorphisms. All ETEC isolates were of the O25:NM (nonmotile) serotype, which carries a heat-stable enterotoxin Ib gene. Genotypic analysis demonstrated that the strains isolated from the patients at all four schools were identical. The isolates of ETEC O25:NM obtained from the tuna paste that had been served for lunch at these schools were genetically indistinguishable from those isolated from the patients. Results suggest that this outbreak was food borne. The molecular biology-based epidemiological techniques used in this study were useful in characterizing the causal agent in this food-borne epidemic.

Animals↗
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↗