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T Ikebe

Publications and source records attributed to T Ikebe.

At least 73 records · Page 4Linked to original sources
PubMed1996

Multiple pleomorphic adenomas arising in the parotid and submandibular lymph nodes.

We report rare case of multiple pleomorphic adenomas arising in the parotid and submandibular lymph nodes of a 21-year-old man. These tumours were surrounded by lymphoid tissue which was almost identical to that of the cortex of lymph node. The possibility of metastasizing pleomorphic adenomas was discounted because the mitotic activity was low and there were no signs of infiltration. Heterotopic salivary gland tissue was also found in the lymph nodes that contained the tumours, and each tumour expressed a similar immunohistochemical staining pattern to that of the salivary gland tissue. These findings indicate that these pleomorphic adenomas probably arose from the salivary gland tissue within the lymph nodes.

Adenoma, Pleomorphic↗
PubMed1996

Mixed germ-cell tumor of the brain. Pathologic study of six autopsy cases.

Intracranial mixed germ-cell tumors are rare. We describe the findings from six autopsies of patients with these tumors. The patients were all young at presentation (mean age, 16 years), and five of the six were male. Headache, vomiting, polyuria and diplopia were common symptoms. Radiographic evaluation demonstrated a mass on the midline of the brain. The patients were treated mainly with radiation, but survival (mean, 3.7 years) was not as long as predicted. At autopsy, the tumors occupied most of the ventricular spaces, and ranged from being well-circumscribed to invasive. All tumors contained both germinoma components and nongerminomatous germ-cell tumor components. Because the distribution of these components was not homogenous, at least two sections were necessary for the diagnosis. Immunoreactivity for placental alkaline phosphatase was found in all tumors. Immunostaining for human chorional gonadotropin, alpha-fetoprotein and carcinoembryonic antigen was usually associated with abnormally high serum levels of these tumors markers in life. A number of the cells in both kinds of tumor components expressed proliferating cell nuclear antigen, probably reflecting the intense malignant potential.

Adolescent↗
PubMed1996

Immunohistochemical staining of desmosomal components in oral squamous cell carcinomas and its association with tumour behaviour.

Desmosomes are intercellular junctions that have been shown to be down-regulated in certain types of carcinomas and that may play a role in suppression of invasion and metastasis. We have shown previously that immunohistochemical staining for the major desmosomal glycoprotein, desmoglein (Dsg), is reduced in some cases of squamous cell carcinoma (SCC) of the head and neck, and that reduced staining correlates with lymph node involvement. Desmosomes are multicomponent organelles. We therefore sought to determine whether another major desmosomal molecule, desmoplakin (Dp), showed similar reduced expression to that shown by desmoglein. We have stained 65 specimens of primary SCC of the oral cavity (37 non-metastatic and 28 metatastic) with monoclonal antibodies to both desmoglein and desmoplakin. We show that reduction of Dp staining correlates with loss of differentiation of the primary tumour, degree of invasion and presence of lymph node metastases. Similar correlations were found with Dsg staining. There was also correlation between reduction in Dp staining and reduction in Dsg staining. It is concluded that down-regulation of desmosomal expression occurs in some cases of SCC of the oral cavity and is associated with invasion and metastasis. Desmosomes may have an invasion and metastasis suppressor function.

Carcinoma, Squamous Cell↗
PubMed1996

Immunohistochemistry and angiography in adenomatous hyperplasia and small hepatocellular carcinomas.

The sinusoidal structure and blood supply of 38 liver nodules less than 2 cm in diameter were investigated. There were 18 cases of adenomatous hyperplasia (AH) and 20 cases of hepatocellular carcinoma (HCC). Growth pattern, encapsulation and vascularity were examined, and immunohistochemistry performed for factor VIII related antigen (factor VIII), type IV collagen (collagen IV), laminin and CD68. There were significant differences between AH and small HCC, except for the expression of CD68. There were differences in tumor size, vascularity and the components of the basement membrane between AH and small, well differentiated HCC. The cases of AH were supplied by the portal system and maintained the sinusoidal structure, but small well-differentiated' HCC were supplied by a mixture of portal and arterial vessels. In spite of their small size, moderately and poorly differentiated HCC had capillary and were supplied by branches of the hepatic artery.

Aged↗
PubMed1996

Detection of serum antibodies against Chlamydia pneumoniae by ELISA.

Chlamydia pneumoniae causes pneumonia and other respiratory infections in children, adolescents and adults. We tried to evaluate the diagnostic value of detection of serum antibodies by ELISA for C. pneumoniae infections in Japanese children. Serum IgG, IgA and IgM antibodies to C. pneumoniae were determined by the microimmunofluorescence (MIF) test. Serum IgG and IgA antibodies were also determined by ELISA test kits. Results obtained by ELISA were compared with those obtained by MIF test. IgG antibody to C. pneumoniae was detected in 135 (39.5%) by ELISA and in 125 (36.5%) by MIF out of 342 sera from Japanese infants and children without respiratory infections (aged from 2 months old to 15 years old). IgA antibody to C. pneumoniae was detected in 129 (37.7%) by ELISA and in 117 (34.2%) by MIF out of 342 sera tested. Of 342 specimens 113 were IgG-positive by ELISA and MIF (sensitivity: 90.4%, specificity: 89.9%, r = 0.853). Of 342 sera 28 had IgG antibody titers of 1:256 and none had titers 1:512 or higher by MIF. Of 28 infants and children a total of nine were less than 4 years of age. On the other hand, of 342 specimens 99 were IgA-positive by ELISA and MIF (sensitivity: 84.6%, specificity: 86.7%, r = 0.769). Of 342 sera 16 had IgA antibody titers of 1:256 or higher by MIF. Of 16 infants and children, ten were less than 4 years of age. ELISA had excellent sensitivity and specificity relative to MIF test for detection of IgC and IgA antibodies to C. pneumoniae. It was suggested that C. pneumoniae infection in Japanese infants and children under 4 years of age was not infrequent.

Adolescent↗
PubMed1996

[Atherosclerosis and clinical examination: epidemiology of stroke and ischemic heart disease].

We discussed the risk factors for stroke and ischemic heart disease (IHD) as a main atherosclerotic disease. We showed that hypertension was the most principal risk factor for both cerebral hemorrhage and cerebral infarction, and the increase of total cholesterol (TCH) was inversely related with the incidence of cerebral hemorrhage. Many of the cerebral infarctions occurred where a large number of the cerebral hemorrhages did. We indicated that the mechanism of occurrence was different between stroke and IHD. In Japan, TCH has been recognized as a risk factor for IHD as same as western countries, but there are not many IHD. The mean of TCH was lower before one or two decade. But, it has increased in the last decade, and recently is nearing the level of American people in the thirties and forties. Death statistics of IHD became more accurate in Japan by reason for revision of the death certificate form from ICD-9 to ICD-10. The recognition of IHD death statistics will be changed. Incidence of stroke has been decreasing because of the decrease of hypertension. However, we will have to reconsider a preventive measure of IHD.

Adult↗
PubMed1995

Interleukin 1-induced phosphorylation of MAD3, the major inhibitor of nuclear factor kappa B of HeLa cells. Interference in signalling by the proteinase inhibitors 3,4-dichloroisocoumarin and tosylphenylalanyl chloromethylketone.

The regulation of the inhibitor of nuclear factor kappa B (I kappa B) by interleukin 1 (IL1) was investigated in HeLa cells. Two forms of I kappa B were resolved by ion-exchange chromatography. The major form (75%) was identified as MAD3 by specific antisera. IL1 generated rapidly (6 min) an electrophoretically retarded form of MAD3 that was stable in acid and was converted into the unmodified form by phosphatase 2A. It thus corresponded to a phosphorylation of the protein on serine or threonine. IL1 also caused the disappearance of MAD3 from the cells, which was complete 15 min after stimulation and coincided with a 46% reduction of cellular I kappa B activity. Newly-synthesized MAD3 accumulated to pre-stimulation levels between 60 and 90 min after stimulation and this coincided with the down-regulation of the phosphorylating activity. The serine proteinase inhibitors 3,4-dichloroisocoumarin (DCI) and tosylphenylalanyl chloromethylketone (TPCK) prevented phosphorylation and disappearance of MAD3. At the same concentrations (10-100 microM), they also increased basal phosphorylation of the small heat shock protein (hsp27) and prevented the IL1- and phorbol 12-myristate 13-acetate-induced increases of its phosphorylation. The inhibitors were thus interfering with protein kinases when blocking degradation of MAD3. Recombinant MAD3 phosphorylated in vitro by protein kinase C was not electrophoretically retarded, suggesting that MAD3 was phosphorylated by another kinase in IL1-stimulated cells. Our results suggest that the IL1-induced phosphorylation of MAD3 on serine or threonine leads to its degradation. DCI and TPCK blocked phosphorylation mechanisms and it could not be concluded that serine proteinases were involved in the breakdown of MAD3.

Base Sequence↗
PubMed1993

Synergism between muramyl dipeptide and lipopolysaccharide in the inhibition of glycosaminoglycan synthesis in cultured rat costal chondrocytes.

The effect of synthetic muramyl dipeptide on glycosaminoglycan synthesis in cultured rat costal chondrocytes was examined. Muramyl dipeptide alone had no effect on the glycosaminoglycan synthesis of rat chondrocytes, whereas Escherichia coli lipopolysaccharide and interleukin 1 alpha inhibited glycosaminoglycan synthesis in a dose dependent manner. Muramyl dipeptide, when added to chondrocyte cultures in the presence of lipopolysaccharide, enhanced the lipopolysaccharide induced inhibition of glycosaminoglycan synthesis in a dose dependent manner. Adjuvant active analogues of muramyl dipeptide, but not adjuvant inactive analogues, also enhanced the lipopolysaccharide induced inhibition of glycosaminoglycan synthesis. In combination with muramyl dipeptide, to inhibit glycosaminoglycan synthesis, lipopolysaccharide could be replaced with the synthetic lipid A, an active principle of lipopolysaccharide. These results show that the muramyl dipeptide portion of bacterial peptidoglycan enhances the susceptibility of rat chondrocytes to the lipid A portion of bacterial lipopolysaccharide, and therefore the interaction between chondrocytes and bacterial cell wall components might be involved in damaging the cartilage in inflammatory joint diseases.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1992

The binding subunit of pertussis toxin inhibits IL-1 induction of IL-2 and prostaglandin production.

The inhibitory effect of pertussis toxin on the action of IL-1 has been investigated. The toxin inhibited IL-1-induced production of IL-2 mRNA and protein in EL4 cells. The B oligomer of the toxin, which was shown to be devoid of ADP-ribosylating activity, proved as inhibitory as the holotoxin. The inhibition was therefore attributable to the binding subunit of the toxin and not to its ability to ADP-ribosylate G proteins. The toxin did not affect the IL-1R binding to its ligand, nor did it inhibit an early post-receptor event, the induction of the transcription factor NF kappa B. This implied that the toxin was not uncoupling IL-1R signaling. The toxin, or its B oligomer, inhibited PGE2 synthesis in human gingival fibroblasts stimulated by IL-1, but not by PMA. Assay of PG synthetic activity in the cells after addition of exogenous arachidonic acid suggested impairment by the toxin of induction of PG-synthesizing enzymes. IL-1 stimulation of IL-6 or collagenase production by fibroblasts was unaffected by pertussis toxin. The binding subunit of the toxin inhibits certain IL-1 responses by virtue of previously unrecognized actions on lymphoid and fibroblastic cells. It does not appear to block early signaling and the inhibition highly unlikely to involve inactivation of a G protein.

Adenosine Diphosphate Ribose↗
PubMed1992

Mass trial of hypoallergenic rice (HRS-1) produced by enzymatic digestion in atopic dermatitis with suspected rice allergy. HRS-1 Research Group.

The clinical usefulness of a hypoallergenic rice (HRS-1) which was produced by enzymatic decomposition of the constituent proteins of original rice was evaluated in a multicentre study in 44 subjects with recalcitrant atopic dermatitis (AD), who were suspected of having rice allergy. The subjects were fed for at least 4 weeks with HRS-1 instead of eliminating both regular rice and wheat from their daily diet. The extent of overall skin lesions was expressed by using the AD affected area and severity index (ADASI). A statistically significant decrease in ADASI was observed at the 2nd and the 4th week readings and at the end of the study. A provocation test with regular rice was carried out in 5 of 44 subjects following the HRS-1 therapy. An obvious increase in ADASI was found in all of these 5 cases just after this procedure. On final evaluation, 77% of the patients tested showed 'moderate' to 'remarkable' improvement, and 59% of the patients a 'moderate' to 'remarkable' reduction in use of the steroid ointment concomitantly used for the treatment. Finally, HRS-1 was evaluated as 'useful' or 'very useful' in 69% of the subjects.

Adolescent↗
PubMed1991

Occlusal contact area and temporomandibular joint symptoms.

A new method for quantitative occlusal measurement is presented. In this study occlusal contact areas in 79 patients with or without temporomandibular joint symptoms were assessed from the simple wax bite. The area of occlusion has showed no distinct differences between the two groups. The occlusal contacts did not show any significant correlations with temporomandibular joint dysfunctions.

Adolescent↗
PubMed1991

[Clinical effect of hypoallergenic rice (HRS-1) in atopic dermatitis. HRS-1 Research Group].

The usefulness of hypoallergenic rice (HRS-1) was clinically evaluated in 43 patients with severe atopic dermatitis (AD), who were suspected of having rice allergy, in collaboration with 13 hospitals. The patients were fed with HRS-1 instead of eliminating both regular rice and wheat from their daily diet. AD area and severity index (ADASI) was calculated as an indicator of the degree of cutaneous symptoms. Significant decrease of ADASI were observed in the 2nd and 4th week and at the end of the replacement therapy (5.6 weeks on average). On final evaluation, 74% of the patients tested showed "moderate" to "remarkable" improvement, and in 53% of the patients HRS-1 resulted in a "moderate" to "remarkable" reduction in the dosage and the grade of potency of the steroid ointment concomitantly used for the treatment. Finally, HRS-1 was evaluated as "useful" to "very useful" as the elimination diet in 70% of the patients.

Adolescent↗
PubMed1990

Mechanism of cyclic GMP inhibition of inositol phosphate formation in rat aorta segments and cultured bovine aortic smooth muscle cells.

In order to clarify the mechanism(s) by which cyclic GMP inhibits the generation of inositol phosphates in rat aorta segments and cultured bovine aortic smooth muscle cells, we studied phosphoinositide hydrolysis and GTPase activity in homogenates and membrane preparations of cultured bovine aortic smooth muscle cells. Pretreatment of homogenate preparations with cyclic GMP plus ATP did not inhibit [8-arginine, 3H] vasopressin (AVP) binding, but resulted in a total suppression of the AVP-induced GTPase activation. The pretreatment with cyclic GMP and ATP also inhibited the formation of inositol phosphates induced by AVP in the presence of low concentrations of guanosine 5'-(gamma-thio)triphosphate (GTP gamma S), or by high concentrations of GTP gamma S alone. However, the formation of inositol phosphates by high concentrations of Ca2+ alone was not blocked. These results suggest that the ability of cyclic GMP to inhibit phosphoinositide hydrolysis results from an inhibition of a guanine nucleotide regulatory protein activation, and the interaction between guanine nucleotide regulatory protein and phospholipase C. While the precise site of this inhibition is not presently known, the inhibition by cyclic GMP is dependent upon the addition of ATP and probably entails a phosphorylation event since adenylylimidodiphosphate can not substitute for the ATP requirement.

Adenosine Triphosphate↗
PubMed1990

Catabolic effects of muramyl dipeptide on rabbit chondrocytes.

Muramyl dipeptide, an essential structure for the diverse biologic activities of bacterial cell wall peptidoglycan, inhibited the synthesis of glycosaminoglycan/proteoglycan in cultured rabbit costal chondrocytes in a dose-dependent manner. Muramyl dipeptide, as well as lipopolysaccharide and interleukin-1 alpha, also enhanced the release of 35S-sulfate-prelabeled glycosaminoglycan/proteoglycan from the cell layer, which seems to reflect, at least partially, the increasing degradation of glycosaminoglycan/proteoglycan. Five synthetic analogs of muramyl dipeptide known to be adjuvant active or adjuvant inactive were tested for their potential to inhibit synthesis of glycosaminoglycan/proteoglycan and to enhance the release of glycosaminoglycan/proteoglycan in chondrocytes. The structural dependence of these synthetic analogs on chondrocytes was found to parallel that of immunoadjuvant activity. These results suggest that muramyl dipeptide is a potent mediator of catabolism in chondrocytes.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1989

Synthetic inositol trisphosphate analogs and their effects on phosphatase, kinase, and the release of Ca2+.

A series of inositol 1,4,5-trisphosphate (IP3) analogs and positional isomers was examined to explore the structure-activity relationships among IP3 5-phosphatase, IP3 3-kinase, and the release of Ca2+. All analogs with additional groups on the 2nd position of IP3 inhibited the hydrolysis of [5-32P]IP3 catalyzed by erythrocyte ghosts, with a lower Ki value than seen with IP3. IP3 dehydroxylated at the 2nd position also had a lower Ki, while 2,4,5-IP3 or cyclic(1:2), 4,5-IP3 had higher Ki values. Among these compounds 2-deoxy-IP3 was as potent as IP3 in inhibiting the phosphorylation by [3H] IP3-3-kinase in rat brain cytosol. The other compounds, except for 2,4,5-IP3 inhibited the phosphorylation, however, 2-30 times higher concentrations were required. By lowering free Ca2+, the concentrations required for half-maximal inhibition were low, while those of IP3, 2-deoxy-IP3, and positional isomers remained unchanged. These compounds acted as full agonists in releasing Ca2+ from permeabilized macrophages, although 1.6-50-fold higher concentrations than IP3 were required. These compounds also inhibited the binding of [3H]IP3 to rat cerebellum and bovine adrenal cortex microsomes, but the potencies were 2.9-33 times less than that of IP3. Thus, the 2nd position of IP3 can be modified with only a slight loss of biological activity.

Animals↗
PubMed1988

Possible binding sites for inositol 1,4,5-trisphosphate in macrophages.

We reported that an arylazide derivative of inositol 1,4,5-trisphosphate (InsP3) caused irreversible InsP3-induced Ca2+ release from saponin-permeabilized macrophages after photoirradiation. To determine the specific receptors for InsP3, presumably present on the endoplastic reticulum, we synthesized isotope-labeled arylazide derivatives of InsP3; InsP3 was coupled with p-azidobenzoyl [3H]beta-alanine (InsP3-[3H]AB beta A) or p-[125I]azidosalicyl beta-alanine (InsP3-[125I]AS beta A). We report here that three proteins may be associated with the Ca2+ releasing mechanism, in photoirradiated saponin-permeabilized macrophages and in the microsomal fraction.

Animals↗
PubMed1988

Effects of human recombinant tumor necrosis factor-alpha and interleukin 1 on the synthesis of glycosaminoglycan and DNA in cultured rat costal chondrocytes.

We examined effects of human rTNF alpha on the synthesis of glycosaminoglycan and DNA in cultured rat costal chondrocytes. The effects of human recombinant IL-1 alpha and IL-1 beta were also given attention. rTNF alpha, as well as rIL-1 alpha and rIL-1 beta, decreased the incorporation of [35S]sulfate into glycosaminoglycan to about 10% of the levels in the control. The half-maximal doses of rTNF alpha, rIL-1 alpha or rIL-1 beta required for the suppression of glycosaminoglycan synthesis (by rTNF alpha, rIL-1 alpha, and rIL-1 beta) were 2 ng/ml, 30 ng/ml, or 5 ng/ml, respectively. rTNF alpha stimulated incorporation of [3H]thymidine in the chondrocytes in a dose- and time-dependent manner. DNA synthesis was increased to about threefold over the control cultures in the presence of 1 microgram/ml rTNF alpha for 72 hr. The stimulatory effect of rTNF alpha on DNA synthesis was observed in both subconfluent and confluent cultures, whereas rIL-1 alpha and rIL-1 beta had no stimulatory activity on DNA synthesis. The addition of rTNF alpha to the cultures of chondrocytes stimulated DNA synthesis, even in medium containing no fetal calf serum. The fetal calf serum acted synergistically with rTNF alpha in increasing DNA synthesis. We propose that both TNF and IL-1 may be involved in inflammatory diseases of cartilage, and that TNF alpha, but not IL-1, may have some physiologic growth factor function for chondrocytes.

Animals↗