Biomedical subjects

T Ihara

Publications and source records attributed to T Ihara.

At least 37 records · Page 2Linked to original sources

PubMed1999

Changes in serum diamine oxidase activity during chemotherapy in patients with hematological malignancies.

Serum diamine oxidase (DAO) activity is very low, but is considered to reflect quantitative changes in small intestinal mass. Therefore, we measured DAO activity during chemotherapy in patients with hematological malignancies in order to evaluate mucosal injury. DAO activity decreased from 1-3 weeks after chemotherapy but returned to initial levels after 4 weeks. As the dosage of anti-cancer drugs increased, DAO activity decreased more, but its activity was not related to other parameters. These findings suggest that serum DAO could be used as an indicator of mucosal injury during chemotherapy.

Adult↗

PubMed1999

Uptake of orally administered polystyrene latex and poly(D,L-lactic/glycolic acid) microspheres into intestinal lymphoid tissues in chickens.

Fluorescein-labeled microspheres were orally administered to chickens and their distribution in intestinal lymphoid tissues was investigated. Polystyrene latex microspheres were observed in Peyer's patches, and also in the Meckel's diverticulum and the jejunum. Their density, however, seemed to be lower than that in Peyer's patches. Microspheres were rarely observed in the other intestinal tissues examined, including the bursa of Fabricius. Of note is that, although microspheres were present in the lumen, few, if any, were observed in the lamina propria of the caecal tonsil and caecum. Polystyrene latex microspheres of diameter 2.0 microm or 4.5 microm were also observed in Peyer's patches, but their density seemed to be lower as compared with the 0.75 microm microspheres. Poly(D,L-lactic/glycolic acid) (PLGA) microspheres were prepared using PLGAs of various molecular weights (MW) and their uptake into Peyer's patches was compared. Microspheres prepared with PLGA of average MW of 20000 were not taken up into Peyer's patches, but those prepared with PLGA of average MW of 61000 or 99 800 were taken up into Peyer's patches.

Administration, Oral↗

PubMed1999

Histopathological Predictors of Axillary Lymph Node Metastases in Patients with Breast Cancer.

BACKGROUND: A tumor 30 mm or less in diameter is a standard candidate for breast conserving surgery (BCS) in Japan. Axillary lymph node metastases (ALNM) is the most important prognostic factor for survival in patients with breast cancer, but the role of axillary node dissection has been controversial. Histopathological predictive factors of axillary lymph node involvement have not been established. The purpose of this study was to determine the association between the incidence of ALNM and histopathological factors by univariate and multivariate analysis METHODS: Sixty-five patients with noninvasive ductal carcinoma, and 993 patients with tumors 30 mm or less in diameter who underwent axillary dissection between 1988 and 1997 at our institute were reviewed. The association between ALNM and 13 histopathological factors (size, age, histological subtype, histological invasiveness, lymphatic invasion, vascular invasion, macroscopic classification, histological daughter mass, ductal spread, ER, PgR, p-53, and c-erbB-2) were analyzed by univariate and, when significant, by multivariate analysis. RESULTS: Only one patient with noninvasive ductal carcinoma had ALNM, and 33.1% of 993 patients with a tumor 30 mm or less in size had ALNM. Multivariate analysis identified six factors as independent predictors for ALNM: lymphatic invasion, size, histological invasiveness, macroscopic classification, age and histological daughter mass. CONCLUSION: Axillary lymph node dissection can be omitted in patients with noninvasive ductal carcinoma. Histopathological features of tumors 30 mm or less in diameter can be used to estimate the risk of ALNM, and routine axillary node dissection might be spared in selected patients at minimal risk of ALNM, if the treatment decision is not influenced by lymph node status, such as in elderly patients.

Journal Article↗

PubMed1999

Expression of interleukin-2 receptor alpha and CD45RO antigen on T lymphocytes cultured with rubella virus antigen, compared with humoral immunity in rubella vaccinees.

We studied the expression of interleukin-2 receptor alpha (CD25)+ CD45RO+ CD4+ T lymphocytes (T-cell activation) in response to the rubella virus (RV) antigen (Matsuura strain, Biken, Osaka, Japan) using three-color-staining flow cytometry. The subjects were 48 healthy children (3-14 years old, 31 boys and 17 girls), who had received either monovalent vaccine (n = 5; mean age, 13.2 years) or measles-mumps-rubella (MMR) vaccine (n = 21; mean age, 10.5 years), had been naturally infected (n = 5; mean age, 11.4 years), or had been neither vaccinated nor naturally infected (n = 17; mean age, 10.0 years) and 62 healthy adolescents and adults (15-37 years old; 19 males and 43 females), who had received monovalent vaccine (n = 26, mean age, 27.4 years), had been naturally infected (n = 8; mean age, 24.0 years), or had been neither vaccinated nor naturally infected (n = 8; mean age, 16.5 years). Ninety-four of 110 subjects had HI titers > or = 1:16. T-cell activation in these subjects was significantly higher than that in 6 seronegative (HI titers < 1:8) subjects (p < 0.05). T-cell activation did not differ significantly with the history of exposure to RV. HI antibody titers > or = 1:16 and T-cell activation persisted in vaccinated subjects for > or = 20 years and was similar to those in naturally infected subjects. Our results suggest that cell-mediated immunity and humoral immunity persist for at least 20 years after vaccination.

Adolescent↗

PubMed1999

Expression of interleukin-2 (IL-2) receptor alpha and CD45RO antigen on T-lymphocytes cultured with measles virus antigens, compared with humoral immunity in measles vaccinees.

In response to two types of measles virus (MV) antigens, a vaccine strain CAM and a wild strain isolated in 1994, the expression of IL-2 receptor alpha (CD25)(+)CD45RO(+)CD4(+) T-lymphocytes (T-cell activation) was analyzed by flow cytometry. In 75 healthy subjects with measles hemagglutination inhibition tests > or =1:16, the percentage of T-cell activation was significantly increased compared with that in seronegative individuals (p) < 0.05). Moreover, the T-cell expression was not significantly different among the vaccinated (n = 38), the naturally infected (n = 28) and the subclinically infected (exposed with wild type without history of measles infection and HI titers > or =1:16) (n = 10) groups. T-cell activation stimulated with MV antigens and HI antibody titers persisted for almost 30 years in the vaccinated group. These results suggest that cell-mediated immunity persists for long periods after vaccination and does not be influenced by antigenic drift.

Adolescent↗

PubMed1999

Stomal recurrence invading the cervicothoracic esophagus and upper mediastinum: resectability and the creation of a safe anterior mediastinal tracheostoma.

Surgical salvage for stomal recurrence is a for midable problem for head and neck surgeons. The two factors of considerable significance are resectability and establishment of a safe anterior mediastinal tracheostoma. A case of stomal recurrence invading the cervicothoracic esophagus and upper mediastinum is presented. Total esophagectomy and upper mediastinal dissection was performed. The esophagus was reconstructed immediately with a pedicled gastric flap. The omentum on the gastric pedicle was wrapped around the trachea to reduce the likelihood of erosion into the great vessels and to supplement the lateral blood supply to the trachea. No serious postoperative complications were observed. We believe that the total esophagectomy improved the resectability, and that the bulk of the gastric pedicle and the use of the omentum prevented significant postoperative complications associated with an anterior mediastinal tracheostoma.

Anastomosis, Surgical↗

PubMed1999

Comparison of adjuvants with respect to serum IgG antibody response in orally immunized chickens.

We have previously shown that oral immunization with non-replicating antigens hardly induced serum IgG antibody response in chickens and addition of sodium fluoride (NaF) to the immunogen markedly improved their immunological states. In the present study, taurine, lithium and Quillaja saponin (Q-SAP) were compared with NaF with respect to their enhancement of serum IgG antibody response in chickens after oral immunization. The antibody titer of chickens which received Q-SAP as the mucosal adjuvant tended to be higher than that of chickens which received antigen plus NaF. Simultaneous administration of antigen with lithium or taurine elicited a higher antibody titer in chickens compared to those of chickens orally immunized with antigen alone, but the effect of these two adjuvants was less efficient compared with that of NaF. These results suggested that Q-SAP as well as NaF is useful as an oral adjuvant for chickens.

Adjuvants, Immunologic↗

PubMed1999

Mouse colitis induced by Escherichia coli producing Yersinia enterocolitica 60-kilodalton heat-shock protein: light and electron microscope study.

In patients with inflammatory bowel disease (IBD), including ulcerative colitis (UC), heat-shock protein (Hsp) 60 has been detected in serum and the intestinal tract. Our mouse colitis model was established using Escherichia coli transformed with Yersinia enterocolitica Hsp60 gene as an immunizing antigen, and examined light and electron microscopically as compared with lesions of UC. The large intestine of mice injected with Hsp60 antigen showed swollen goblet cells, glandular dilation, erosion, ulceration, and infiltration of inflammatory cells. The change like crypt abscesses was also found, and various phases of inflammation were observed simultaneously in individual mice. In addition, the reticulum fibers were absent ultrastructurally in the subepithelial reticular layer. Hyperplasia of the thymus was found in antigen-treated mice. These lesions were similar to those of UC. These results suggest that UC-like enteritis in mice was induced by using Hsp60, considered as one of the pathogens for UC.

Animals↗

PubMed1999

Exposure to diesel exhaust affects the male reproductive system of mice.

Several recent reports have suggested that sperm count and quality in normal men are declining. Various environmental chemical compounds may affect the male reproductive system. We propose here that diesel exhaust is an environmental pollutant with the potential to influence male reproductive function. Ultrastructural changes were observed in Leydig cells of mice exposed to diesel exhaust (0.3 mg diesel exhaust particles (DEP)/m3 through the airway, 12 h daily, up to 6 months) and reduction in LH receptor mRNA expression in Leydig cells was observed at a concentration of 1 mg DEP/m3. Daily sperm production per gram of testis dose-dependently decreased with exposure to DE for 6 months; 29%, 36%, and 53% reductions were observed at 0.3, 1.0, and 3.0 mg DEP/m3, respectively. A no-observed-adverse-effect level (NOAEL) was observed with approximately 30 micrograms DEP/m3, which is lower than the WHO-recommended limit.

Air Pollutants↗

PubMed1999

Medium-chain triglycerides modulate ileitis induced by trinitrobenzene sulfonic acid.

BACKGROUND: It is important to develop an appropriate animal model for further investigation into inflammatory bowel disease (IBD). We therefore investigated a trinitrobenzene sulfonic acid (TNBS) ileitis model. Dietary fat in Crohn's disease is still a controversial risk factor for IBD. We therefore also studied the effects of medium-chain triglycerides (MCT) and long-chain triglycerides (LCT) on TNBS ileitis. METHODS AND RESULTS: An intraileal injection of TNBS induced ulceration and inflammation with thickening of the intestinal wall, which were characterized histologically by infiltration of polymorphic nuclear leucocytes and by granuloma formation. The mucosal damage score and serum sialic acid levels reached their highest 7 days after the TNBS injection and then gradually decreased. The mucosal damage series in the MCT group was significantly lower than in the LCT group, and levels of tumour necrosis factor-alpha (TNF-alpha) and leukotriene B4 (LTB4) tended to be lower in the MCT group. CONCLUSIONS: These results suggested that TNBS enteritis might be useful as an IBD animal model and that MCT modulates intestinal inflammation and is less damaging than LCT.

Analysis of Variance↗

PubMed1999

Metal ion-directed DNA recognition by chelating DNA ligands.

Novel DNA ligand bearing oxine and pyridinium group has been synthesized. The DNA binding of this ligand was regulated by coexisting Cu2+ over the range of more than three orders in magnitude of binding constant. This should be due to the metal-mediated dimerization of the ligand and concomitant emergence of cationic charges. There were definite two DNA binding modes for the ligand dimer depending on the P/L ratio.

Chelating Agents↗

PubMed1999

Outcome of thrombotic thrombocytopenic purpura and hemolytic uremic syndrome in Japan.

We examined 159 patients with thrombotic thrombocytopenic purpura and hemolytic uremic syndrome in Japan. The subjects were divided in three groups; 90 patients with thrombotic thrombocytopenic purpura, 51 patients with verotoxin-induced hemolytic uremic syndrome, and 18 patients with drug-induced hemolytic uremic syndrome. Eighty-two percent of the patients with thrombotic thrombocytopenic purpura had associated neurological disorders and 78% of drug-induced hemolytic uremic syndrome associated with pulmonary edema. Renal insufficiency was noted in the 69% cases with both hemolytic uremic syndrome groups. Seventeen patients with thrombotic thrombocytopenic purpura had systemic lupus erythematosus and 6 were pregnant. Autoantibody were positive in 53% of thrombotic thrombocytopenic purpura. Seventy-seven percent of patients with thrombotic thrombocytopenic purpura received plasma exchange at 4,000 mL/day three times a week, 71% antithrombotic agents, and 78% steroid administration, respectively. However, 27% of the patients with hemolytic uremic syndrome were treated by hemodialysis in addition to antithrombotic agents. When drug-induced hemolytic uremic syndrome was diagnosed, the drug was immediately discontinued and the patients were treated with antiplatelet agents. Seventy-four percent of the patients with thrombotic thrombocytopenic purpura were alive at 26 weeks compared with 95% of those with hemolytic uremic syndrome. As thrombotic thrombocytopenic purpura had a high mortality rate in Japan, we should carry out early diagnosis and early treatment.

Adolescent↗

PubMed1998

Callosal window between prefrontal cortices: cognitive interaction to retrieve long-term memory.

A perceptual image can be recalled from memory without sensory stimulation. However, the neural origin of memory retrieval remains unsettled. To examine whether memory retrieval can be regulated by top-down processes originating from the prefrontal cortex, a visual associative memory task was introduced into the partial split-brain paradigm in monkeys. Long-term memory acquired through stimulus-stimulus association did not transfer via the anterior corpus callosum, a key part interconnecting prefrontal cortices. Nonetheless, when a visual cue was presented to one hemisphere, the anterior callosum could instruct the other hemisphere to retrieve the correct stimulus specified by the cue. Thus, although visual long-term memory is stored in the temporal cortex, memory retrieval is under the executive control of the prefrontal cortex.

Analysis of Variance↗

PubMed1998

Adjuvant effects of fluoride on oral immunization of chickens.

The present study was conducted to examine the antibody responses of chickens after oral immunization and the influence of sodium fluoride (NaF) on their immunological states. Bovine serum albumin (BSA) was used as an antigen, and the response was measured by enzyme-linked immunosorbent assays of serum samples, bile samples, and lachrymal fluids. Oral immunization of chickens with antigen alone hardly induced antibody responses in sera, bile samples or lachrymal fluids. Moreover, compared to control chickens, these orally immunized chickens exhibited a lower serum IgG response to subsequent parenteral immunization, suggesting that oral immunization induced immunological tolerance in chickens. A mucosal adjuvant, NaF, could abrogate oral tolerance and elicit an increase in antibody responses. Chickens, which received oral administration of antigen and NaF simultaneously, showed a significant rise in serum IgG antibody. Although there were variations among individual chickens and the titers were low, IgA antibodies were detected in bile samples and lachrymal fluids.

Adjuvants, Immunologic↗

PubMed1998

The process of ultrastructural changes from nuclei to apoptotic body.

There have been many reports on the formation of apoptotic bodies, but little is known about the cellular pathological processes and the morphological changes involved. We induced apoptotic cell death by administering nivalenol (NIV), a trichothecene mycotoxin produced by Fusarium species, and investigated the ultrastructural process of formation of apoptotic bodies. The thymus was examined by electron microscopy 6, 12, and 18 h after administration. Apoptotic cell death was induced in the thymus of NIV-treated mice. The nuclei became invaginated and pinched off to give fragments, and crescent-shaped spaces (CSS) were found around the nuclear envelopes of these cells at quite an early stage. In some of these spaces, myelin figures were observed. We divided the process of formation into four stages and characterized each of them. These are easily recognized in morphological stages and are also useful for clarifying the apoptotic mechanism.

Animals↗

PubMed1998

Gelatin-induced T-cell activation in children with nonanaphylactic-type reactions to vaccines containing gelatin.

BACKGROUND: Many cases of anaphylactic or nonanaphylactic reactions have been reported to measles-mumps-rubella vaccine or its component vaccines that contain gelatin as a stabilizer. Increased levels of specific IgE antibodies to gelatin have been reported in children with anaphylactic reactions. However, IgE is not increased in cases of nonanaphylactic reaction, and the mechanisms of the reaction are still controversial. OBJECTIVE: The study was aimed to elucidate the relationship between nonanaphylactic reaction and gelatin. METHODS: We investigated in vitro induction of activated memory helper T cells (CD4(+ )CD25(+ )CD45RO+ cells) in response to gelatin in children with nonanaphylactic reactions to vaccines containing gelatin. RESULTS: In patients with delayed-type sensitivity to gelatin confirmed with a positive skin test response, CD4(+ )CD25(+ )CD45RO+ cells were significantly more strongly induced in culture containing gelatin than in control cultures. However, there was no significant difference between cultures with gelatin and those with control solvent in patients without reactions after vaccination. Of 76 patients with nonanaphylactic reactions after immunization with vaccine containing gelatin, 61 had an increased lymphocyte stimulation index to gelatin versus control children. CONCLUSION: These results suggest the possibility that nonanaphylactic reactions to gelatin-containing vaccine in Japan might be mediated by delayed hypersensitivity reactions against gelatin.

Anaphylaxis↗

PubMed1998

Activation of lymphocytes by HHV-6 antigen in normal children and adults.

We investigated the immune reaction of lymphocytes in response to human herpes virus-6 (HHV-6) in normal children and adults. Cell proliferation was assayed by measurement of the incorporation of 5-bromo-2'-deoxyuridine (BrdU) by enzyme-linked immunosorbent assay (ELISA), and changes in expression of interleukin-2 receptors (IL-2Rs) (alpha-, beta3-, and gamma-chain) were assayed by flow cytometry. Incorporation of BrdU and expression of IL-2Rs (alpha-, beta-, and gamma-chain) in CD4+, CD8+, and CD45RO+ lymphocytes were increased when peripheral blood mononuclear cells (PBMC) from HHV-6 seropositive children aged 3 to 12 years and adults were cultured with HHV-6 antigen compared with control antigen. In contrast, cord blood mononuclear cells (CBMC) and PBMC from seronegative children did not show cell proliferation and changes in expression of IL-2Rs. In seropositive children less than 2 years of age, the magnitude of cell proliferation was low and IL-2Rs (alpha-, beta-, and gamma-chain) in CD8+ cells and IL-2Rs (alpha-chain) in CD45RO+ cells were increased. These data suggest that children below the age of 2 had immature lymphocytic response to HHV-6 antigen. Deletion of monocytes from PBMC and the addition of a mixture of anti-IL-2Rs (alpha-, beta-, and gamma-chain) antibodies reduced cell proliferation in response to HHV-6, suggesting the requirement of the presence of monocytes and expression of IL-2Rs.

Adult↗

PubMed1998

Suppression of arachidonic acid cascade-mediated apoptosis in aflatoxin B1-induced rat hepatoma cells by glucocorticoids.

It has been shown that hypophysectomy protects aflatoxin B1 (AFB1) hepatocarcinogenesis and the prevention of apoptosis is a critical process for tumorigenesis. In this paper, we analyzed the cell death of AFB1-induced rat hepatoma Kagura-2 (K2) cells elicited by an estrogen antagonist, tamoxifen (TAM), and transforming growth factor-beta1 (TGF-beta1) to elucidate the function of endocrine factors in AFB1 hepatocarcinogenesis. TAM and TGF-beta1 induced a typical apoptosis in K2 cells. The apoptotic cell death was efficiently suppressed by glucocorticoids (GCs), but not by other steroid compounds including 17beta-estradiol (E2). Cyclo-oxygenase (COX) inhibitors such as aspirin (ASP) and indomethacin (IND) also inhibited the apoptosis, while inhibitory effects of general lipoxygenase (LOX) inhibitors such as nordihydroguaiaretic acid (NDGA) and 5,8,11-eicosatrienoic acid (ETI) were not observed. TAM and TGF-beta1 enhanced the release of [3H]arachidonic acid (AA) from pre-labeled K2 cells, which was inhibited by dexamethasone (DEX). Furthermore, cytosolic phospholipase A2 (cPLA2) activity in K2 cells treated with TAM for 2 h was higher than that in the control. Prostaglandin J2 (PGJ2) and delta12-PGJ2, AA metabolites formed in the COX pathway, induced K2 cell death. These results suggest that AA metabolites are involved in apoptotic K2 cell death elicited by TAM and TGF-beta1, and GCs could act as a tumor promoter in AFB1 hepatocarcinogenesis through the prevention of apoptosis induced by AA metabolites formed in vivo.

Aflatoxin B1↗