Biomedical subjects

H Agata

Publications and source records attributed to H Agata.

At least 19 recordsLinked to original sources

PubMed1998

Slow induction with sevoflurane was associated with complete atrioventricular block in a child with hypertension, renal dysfunction, and impaired cardiac conduction.

We describe the appearance of complete atrioventricular block (CAVB) with sevoflurane and nitrous oxide during the slow induction in a ten-year-old male patient with hypertension, renal dysfunction, and impaired cardiac conduction. Sinus rhythm was restored following the washout of the anaesthetic gas. And CAVB recurred after the subcutaneous injection of lignocaine. The present report shows that sevoflurane should be treated with care like other inhalational anaesthetics as regards the effect on cardiac conduction.

Anesthesia, General↗

PubMed1998

[Pilot study of relapsed osteosarcoma and brain tumor with ifosfamide, carboplatin and etoposide (ICE therapy)].

Ifosfamide, Carboplatin and Etoposide (ICE) therapy was used to treat 4 patients, 2 with refractory osteosarcoma, and one each with relapsed brain tumor and newly diagnosed brain tumor. ICE therapy was administered in doses of Ifosfamide 1,800 mg/m2 x 5, Carboplatin 400 mg/m2 x 2 and Etoposide 100 mg/m2 x 5. A total of 30 courses were administered. Two cases of osteosarcoma had a stable disease (range, 3-9 months) and 2 cases of brain tumor had a complete response by magnetic resonance imaging. Moderate or severe toxicity evaluated on a per course basis included: neutropenia 83%, thrombocytopenia 93%, fever 30%, hepatotoxicity 3%, and hemorrhagic cystitis 3%. The median time to hematologic recovery was 20 days. ICE therapy is highly effective for the treatment of refractory or recurrent solid tumors with acceptable toxicity.

Adolescent↗

PubMed1997

Cerebral cortex regional blood flow and tissue oxygen tension during the trigeminal depressor response in rabbits.

The trigeminal depressor response (TDR) is characterized with profound hypotension caused by sympathetic outflow decreases. The purpose of this study was: (1) to compare the hemodynamic changes during acute hypotension induced by the TDR with those induced by electrical stimulation of the vagal nerve (VS) as models of sympathetic inhibition and vagal activation and (2) to investigate the effects of nitrous oxide (N2O), a well-known sympathomimetic, on the hemodynamic changes during the TDR. Male Japan White rabbits were anesthetized with halothane in oxygen and mechanically ventilated. The electrode pair for the TDR was inserted into the submucosal tissue of the animal's tongue. The pair for the VS was applied to the isolated left vagal trunk. Both the TDR and the VS produced similar decreases in mean arterial pressure (MAP) and cerebral cortex regional blood flow (rCBF), although the decreases in heart rate (HR) and aortic blood flow were greater during the VS. Cerebral cortex tissue oxygen tension in both groups decreased slightly. 50% N2O, producing MAP elevation and HR decrease, ameliorated the hemodynamic changes including rCBF reduction during the TDR. A sudden diminution of sympathetic tone following noxious stimulation of the orofacial area, as in the case of the TDR, may be a possible trigger mechanism for vasodepressor reactions in dental patients. The sympathomimetic and possible antinociceptive effects of N2O may explain, at least in part, the preventive effects on vasodepressor reactions during dental procedures.

Animals↗

PubMed1997

A study of learning splice sites of DNA sequence by neural networks.

To predict of splice sites in DNA sequence, we developed a neural network system with back propagation. This system has a flexible network definition language which can describe any network structure. Three types of neural network were defined using the system for the prediction of splice sites. The neural networks are trained by the arrangements of bases around the splice sites of DNA sequences. The results of simulation showed the excellent ability of the neural networks to predict splice sites by applying and testing the arrangements of DNA sequences. This system also were used to predict the effects of point mutations on the splicing of the IX factor gene which may cause hereditary disease.

Algorithms↗

PubMed1997

Pulmonary hemosiderosis with hypersensitivity to buckwheat.

BACKGROUND: Adverse reactions after ingesting buckwheat are known to be IgE-mediated. Further, hypersensitivity reactions may be involved in some patients with pulmonary hemosiderosis related to cow milk sensitivity. We, however, encountered a patient with pulmonary hemosiderosis related to buckwheat protein without high levels of buckwheat-specific IgE antibodies. OBJECTIVE: The aim of this study was to investigate the mechanisms. METHODS: RAST for anti-buckwheat IgE, skin prick test, skin patch test, and proliferative responses of peripheral blood mononuclear cells to buckwheat were investigated in this patient. RESULTS: RAST values for buckwheat protein were negative, and skin prick test for buckwheat protein also gave negative results. On the other hand, skin patch testing for buckwheat protein elicited positive responses. Further, peripheral blood mononuclear cells of our patient responded to buckwheat protein. CONCLUSIONS: Our patient had pulmonary hemosiderosis related to non-immediate buckwheat protein hypersensitivity.

Cells, Cultured↗

PubMed1997

Combinations of IgE values and lymphocyte proliferative responses for consideration of the clinical course of infantile hen's-egg-sensitive atopic dermatitis.

We have attempted a new approach, using peripheral blood mononuclear cells (PBMCs), to predict the clinical course of infantile food-sensitive atopic dermatitis (AD). In this study, we investigated the relationships between the clinical course of infantile hen's-egg-sensitive AD and laboratory data obtained at the early stage of AD, particularly on combinations of specific IgE antibodies to hen's egg and proliferative responses of PBMCs to ovalbumin (OA). Total IgE concentrations, specific IgE antibodies to hen's egg and proliferative responses of PBMCs to OA were measured in 31 hen's-egg-sensitive AD patients within 6 months after development of AD symptoms. After the acquisition of laboratory data, the clinical courses of all patients were followed up for 1 year. The stimulation index of proliferative responses of PBMCs to OA in hen's-egg-sensitive AD patients whose symptoms did not improve was significantly (p < 0.05) higher than that in hen's-egg-sensitive AD patients whose symptoms improved. On the other hand, the radioallergosorbent test (RAST) scores for hen's egg were not statistically different between the two groups. The degree of refractoriness of AD symptoms tended to be higher in the patients who showed a higher total IgE concentration at the beginning of the clinical course than in those who showed a lower one. These results might be attributed to the underlying cause of AD, i.e., a cell-mediated and an IgE-mediated allergy. We concluded that, in addition to total IgE concentrations, combinations of RAST values and lymphocyte proliferative responses to OA are important to predict the clinical course of infantile hen's-egg-sensitive AD.

Allergens↗

PubMed1996

Interferon-gamma and interleukin-4 production of ovalbumin-stimulated lymphocytes in egg-sensitive children.

BACKGROUND: The causal relation between egg allergy and cytokines derived from lymphocytes is unknown. OBJECTIVE: Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) production of ovalbumin-stimulated and interleukin-2 (IL-2)-stimulated peripheral blood mononuclear cells from egg-sensitive patients was investigated and compared with that of stimulated peripheral blood mononuclear cells from nonatopic healthy children. METHODS: Peripheral blood mononuclear cells from egg-sensitive patients and nonatopic healthy children were cultured with ovalbumin and IL-2 for seven days. The IFN-gamma and IL-4 concentrations in culture supernatants of the peripheral blood mononuclear cells were investigated. RESULTS: The levels of IFN-gamma production of only IL-2-stimulated or both ovalbumin-stimulated and IL-2-stimulated peripheral blood mononuclear cells from egg-sensitive patients with atopic dermatitis was significantly higher than that of healthy children and that of egg-sensitive patients with immediate allergic symptoms. CONCLUSIONS: Increased IFN-gamma production by lymphocytes after IL-2 and antigen stimulation has important implications for the mechanism of food-sensitive atopic dermatitis.

Cell-Free System↗

PubMed1995

Genetic analysis of IgE and the IGHE, IGHEP1 and IGHEP2 genes in atopic families.

The familial occurrence of allergic diseases was studied in 478 individuals and their family members. The results showed that there was pronounced familial clustering. Total serum IgE concentrations of atopic patients and their parents were well correlated. Moreover, the concentration of specific IgE of the patients and their parents was also well correlated, suggesting that IgE production was genetically determined. To determine if major structural abnormalities of IGHE, IGHEP1 and IGHEP2 genes might lead to aberrant control and subsequent increase in IgE concentration, genomic DNAs from 55 individuals, i.e., 31 atopic patients and their family members, were examined. We detected the IGHE, IGHEP1 and IGHEP2 genes in all 55 leukocyte DNAs. We could not find any large deletions or duplications in the IGHE, IGHEP1 and IGHEP2 genes of atopic patients with high serum IgE concentrations.

Adolescent↗

PubMed1995

T cell proliferation restricted by HLA class II molecules in patients with hen's egg allergy.

We investigated the synergistic effect of anti-HLA class II monoclonal antibodies on proliferative responses to ovalbumin (OA) of T cell line (TCL) cells from five hen's-egg-sensitive patients. Among the five patients, the proliferation of the TCL cells from two patients with AD who have a low immune reaction was restored by the anti-HLA-DQ monoclonal antibodies, and the proliferation of the TCL cells from the other three patients was inhibited by the anti-HLA-DP monoclonal antibodies. These results suggest that a component of the T cell repertoire reactive with OA in hen's-egg-sensitive patients may be restricted by HLA-DP molecules. Furthermore, in hen's-egg-sensitive patients with AD who have a low immune reaction, low responsiveness may be regulated by HLA-DQ molecules.

Animals↗

PubMed1995

Differences in lymphocyte proliferative responses to food antigens and specific IgE antibodies to foods with age among food-sensitive patients with atopic dermatitis.

BACKGROUND: Clinical symptoms of patients with food-sensitive atopic dermatitis often improve with increasing age. OBJECTIVE: To investigate this tendency and the underlying mechanism. METHODS: We selected and divided 194 food-sensitive atopic dermatitis patients into three age groups. The proliferative responses of peripheral blood mononuclear cells (PBMCs) to food antigens and specific IgE antibodies to foods then were evaluated with respect to age. We also followed up 55 food-sensitive patients with atopic dermatitis and examined their improvement ratio after 1 year. Further, we investigated changes in lymphocyte proliferative responses to food antigens and specific IgE antibodies to foods in food-sensitive patients with atopic dermatitis during elimination diets. RESULTS: Proliferative responses of PBMCs to ovalbumin of patients in the over 6-years-old group were significantly (P < .05) lower than those of the less than 1-year-old group. Proliferative responses of PBMCs to bovine serum albumin of patients in the over 6-years-old group were significantly (P < .05) lower than those in the 1 to 5-year-old group and in the less than 1-year-old group. RAST values for hen egg in the over 6-years-old group were significantly (P < .05) lower than those for the less than 1-year-old group. Improvement was shown by 13 of the 33 hen egg-sensitive patients with atopic dermatitis, an improvement ratio of 39%, and by 9 of the 22 cow milk-sensitive patients with atopic dermatitis, an improvement ratio of 41%. Proliferative responses of PBMCs to food antigens in food-sensitive patients with atopic dermatitis decreased rapidly after patients were placed on elimination diets. CONCLUSION: The PBMC proliferative responses to food antigens and RAST values were higher for young children and lower for older ones who suffered from food-sensitive atopic dermatitis. Oral tolerance, in addition to the development of digestive and absorptive functions, may be responsible for these immunologic changes.

Adolescent↗

PubMed1995

Prevalence of and risk factors for allergic diseases: comparison of two cities in Japan.

BACKGROUND: Differences in the prevalence of allergic diseases and the effects of genetic and environmental factors on these diseases in two areas of the same country have not been examined by multiple logistic regression. OBJECTIVE: To determine whether the effects of genetic and environmental factors on allergic diseases differ between two areas. METHODS: A questionnaire was distributed in March 1991 to children less than 16 years old attending kindergarten, elementary, or junior high school in two Japanese cities; Gifu, with a temperate climate, and Itoman, with a subtropical one. The number of subjects analyzed were 1243 in Gifu and 1953 in Itoman. Multiple logistic regression analysis was performed using SAS. RESULTS: The prevalence of allergic diseases and atopic dermatitis in Gifu were significantly higher than in Itoman (P < .05). In contrast, the prevalence of bronchial asthma in Itoman was significantly higher than in Gifu (P < .05). Multiple logistic regression analysis showed that in both cities children of families with allergic histories have significantly higher risk of contracting an allergic disease and atopic dermatitis. The prevalences of allergic diseases and atopic dermatitis were higher in Gifu than in Itoman, even after being controlled for genetic and environmental factors. CONCLUSIONS: The increased risk of contracting an allergic disease and atopic dermatitis for the children in Gifu may be due to such factors not included in the study as climate, eating habits, or the level of air pollution.

Adolescent↗

PubMed1994

A general purpose neural network simulator system for medical data processing.

We developed a general purpose neural network simulator system for medical data processing. This system has a flexible network definition language. Users can define arbitrary hierarchical neural networks using the definition language to analyze medical data that contains some complex patterns. The learning algorithm used in this system is back propagation. Learning curves are displayed on multiple windows. This is a general purpose system, so it can be used for various kinds of medical data processing such as one dimensional signal processing or two dimensional image processing. The system can run on a standard UNIX workstation, which is faster and more powerful than most personal computers. The system needs an X window system/Motif and C compiler. These are standard system programs already available on most UNIX workstations. The source code of the system can be retrieved from our anonymous ftp site via Internet.

Algorithms↗

PubMed1994

Proliferative responses towards native, heat-denatured and pepsin-treated ovalbumin by peripheral blood mononuclear cells from patients with hen's egg-sensitive atopic dermatitis.

In order to clarify the mechanism of food-antigen recognition, the proliferative responses of peripheral blood mononuclear cells (PBMCs) to native, heat-denatured or pepsin-treated ovalbumin (OA) were investigated in 16 hen's egg-sensitive patients with atopic dermatitis (AD). Seven of them had hypersensitivity to boiled hen's egg and others had not. The responses of PBMCs to heat-denatured OA were lower than those to native OA in the patients without hypersensitivity to boiled hen's egg. However, there were no differences of the responses of PBMCs between heat-denatured OA and native OA in the patients with hypersensitivity to boiled hen's egg. Moreover, the reduction of the responses of PBMCs to pepsin-treated OA was recognized in six out of seven patients. The primary structure of OA did not change by heating or pepsin treatment according to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). These results suggested that the secondary structure of OA changed in connection with the reduction of the responses of PBMCs to denatured OA. In addition, we demonstrated the suppressive effect of anti-HLA-DR and anti-HLA-DQ monoclonal antibodies on the proliferative response of PBMCs to OA. The results suggested that the proliferative responses of PBMCs to OA were restricted by HLA-DR or HLA-DQ in hen's egg-sensitive patients with AD.

Antibodies, Monoclonal↗

PubMed1994

Predictive values of cord blood IgE and cord blood lymphocyte responses to food antigens in allergic disorders during infancy.

Proliferative response of cord blood lymphocytes stimulated twice by food antigens and cord blood IgE concentration were measured in 131 full-term newborn infants for the prediction of allergic disorders. Through the follow-up study for 2 1/2 years, the value of stimulation index in proliferative response of cord blood lymphocytes to ovalbumin or bovine serum albumin was greater than 1.5 in 17 (sensitivity 53.1%) of 32 infants in whom allergic disorders developed and less than 1.5 in 81 (specificity 81.8%) of 99 infants who had no allergic disorders (cutoff limit of stimulation index 1.5). The sensitivity was increased (71.9%) by the combination of the cord blood IgE concentration (cutoff limit 1.0 IU/ml) and proliferative response of cord blood lymphocytes to food antigens (cutoff limit of stimulation index 1.5). The combination of the cord blood IgE concentration and proliferative response of cord blood lymphocytes to food antigens is useful for the prediction of allergic disorders. Interleukin-2 production of cord blood lymphocytes stimulated with food antigens was also measured in 24 newborn infants. Interleukin-2 activity in culture supernatants of ovalbumin- or bovine serum albumin-stimulated cord blood lymphocytes correlated well with proliferative response of cord blood lymphocytes to ovalbumin or bovine serum albumin.

Antigens↗

PubMed1994

Identification of monocyte chemotactic factors in supernatants of ovalbumin-stimulated lymphocytes from patients with atopic dermatitis who are sensitive to hen's egg.

Monocyte chemotactic activities in supernatants of ovalbumin (OA)-stimulated peripheral blood mononuclear cell (PBMC) cultures were studied in patients with atopic dermatitis (AD) who were sensitive to hen's egg. The monocyte chemotactic activities in hen's egg-sensitive AD patients were significantly higher than those of non-atopic healthy controls and patients with immediate allergic symptoms. However, the monocyte chemotactic activities were not detected in bovine serum albumin-stimulated PBMC culture supernatants in patients with AD who were sensitive to hen's egg, but not to cow's milk. Furthermore, there was significant correlation between the monocyte chemotactic activities and proliferative responses of PBMCs to OA in hen's egg-sensitive AD patients, whereas there was no significant correlation between the monocyte chemotactic activities and radioallergosorbent test values. These results suggest that PBMCs stimulated with food antigens produce monocyte chemotactic factors which relate to the pathogenesis of AD in food-sensitive AD patients and that the pathogenesis of AD may be related to cell-mediated immune responses.

Adolescent↗

PubMed1994

Suppression of proliferative responses of lymphocytes to food antigens by an anti-allergic drug, ketotifen fumarate, in patients with food-sensitive atopic dermatitis.

Experimental studies have shown that ketotifen fumarate inhibits reaginic antibody-mediated hypersensitivity reactions. In this study, the proliferative responses of peripheral blood mononuclear cells (PBMCs) to ovalbumin (OA) in children with atopic dermatitis (AD), who are sensitive to hen's egg, were significantly higher than those of healthy children. The proliferative responses of PBMCs to OA were dose-dependently inhibited by ketotifen in patients with hen's egg-sensitive AD. Moreover, the inhibition resulted from the effects of ketotifen on T cells. In contrast, the proliferative responses of PBMCs to phytohemagglutinin and tetanus toxoid were not inhibited by ketotifen. These results suggest that ketotifen inhibits food antigen-specific proliferative responses of PBMCs in patients with food-sensitive AD.

Child, Preschool↗

PubMed1994

Timing of onset of allergic symptoms as a response to a double-blind, placebo-controlled food challenge in patients with food allergy combined with a radioallergosorbent test and the evaluation of proliferative lymphocyte responses.

The timing of onset of allergic symptoms in a double-blind, placebo-controlled food challenge (DBPCFC) was combined with a radioallergosorbent test (RAST) and evaluation of proliferative responses of peripheral blood mononuclear cells (PBMCs) in 27 atopic dermatitis patients with hen's egg allergy. Of the 27 patients, 11 showed reactions within 2 h (immediate group), and 16 showed reactions after more than 2 h (nonimmediate group) after ingestion of hen's egg. The RAST scores for hen's egg in the immediate group were significantly (p < 0.01) higher than those in the nonimmediate group, while the proliferative responses of PBMCs to ovalbumin in the nonimmediate group were significantly (p < 0.01) higher than those in the immediate group. These results suggest that the RAST values are related to immediate allergic symptoms in DBPCFC and the proliferative responses of PBMCs are related to nonimmediate allergic symptoms in DBPCFC. The timing of onset of allergic symptoms in DBPCFC will render DBPCFC more useful in the diagnosis of food allergy, including the late-onset reactions to foods.

Adolescent↗

PubMed1994

Characterization of infiltrating CD4+ cells in atopic dermatitis using CD45R and CD29 monoclonal antibodies.

Tissue sections from the skin of patients with atopic dermatitis were investigated by means of hematoxylin-eosin staining, the avidin-biotin-peroxidase complex method, and double-labeling immunofluorescence using monoclonal antibodies to cell-surface antigens, including CD45R and CD29. In skin lesions of patients with atopic dermatitis, the epidermis was spongiotic and hyperplastic with little cellular infiltrate. Perivascular dermal infiltrate was significant and consisted primarily of mononuclear cells. The majority of the infiltrating mononuclear cells in the skin of patients with atopic dermatitis were CD4+ cells. Langerhans' cells were also increased in number. Furthermore, we investigated the subsets in the infiltrating CD4+ cells by double-labeling immunofluorescence using CD45R and CD29 monoclonal antibodies. Among the infiltrating CD4+ cells, CD4+CD29+ cells were dominant and CD4+CD45R+ cells were also present.

Adolescent↗