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T Kasama

Publications and source records attributed to T Kasama.

At least 37 records · Page 2Linked to original sources

[The cytokine network and development of immune-based intervention in mycobacterial infection].

Cell-mediated immunity, which is activated through the macrophage-cytokine-CD4 helper T cell axis, plays a key role in host defense against mycobacterial infection. In the process, protection in the host is a local event focused on granulomatous lesions that may lead to tissue damage including caseous necrosis, cavity formation, fibrosis, and consequently respiratory failure and marked deformity. The immune response to tuberculosis is a double-edged sword that may contribute to both clearance of infection and tissue damage. In experimental mouse models, immune-based intervention by interleukin (IL) 12 replacement therapy showed antimycobacterial activity in established infection but simultaneously induced both local and systemic toxicities, such as augmentation of granulomatous inflammation and damage to muscles, liver, and blood. Intermittent combination therapy including antimicrobial chemotherapy (rifamycins) and cytokine (IL-12) immune therapy resulted in maximal defense and minimal inflammation without toxicities. Although observations in mice cannot necessarily be extrapolated directly to humans, there has been a continuing hope that immune-based intervention and combination therapy, available in potentially unlimited quantities by biotechnology, albeit at considerable expense, would have a major impact on treatment of infectious diseases caused by drug-resistant microorganisms. In addition, the understanding of host defense mechanisms facilitates development of new vaccines for mycobacterial diseases.

Animals↗

Diesel exhaust particles induce NF-kappa B activation in human bronchial epithelial cells in vitro: importance in cytokine transcription.

Fine particles derived from diesel engines (diesel exhaust particles, DEP) have attracted attention, since their density in industrial countries seems related to the increased prevalence of pulmonary diseases. Previous studies have suggested that DEP have a potential to directly activate airway epithelial cells to produce and release inflammatory cytokines and mediators, and thus facilitate inflammatory responses in the lung. To elucidate the molecular mechanisms of their action, we studied here IL-8 gene expression, one of the important cytokines in inflammatory responses, by Northern blot analysis and run-on transcription assay. Suspended DEP (1-50 microgram/ml) increased the steady state levels of IL-8 mRNA, which was suggested to be largely due to increased transcriptional rates. Electrophoretic mobility shift assay demonstrated that DEP induced increased binding to the specific motif of NF-kappa B, but not of transcription factor AP-1. The luciferase reporter gene assay using wild-type and mutated NF-kappa B-binding sequences showed that DEP-induced NF-kappa B activation was involved in IL-8 transcription. Finally, both N-acetylcysteine and pyrrolidine dithiocarbamate attenuated the action of DEP on IL-8 mRNA expression, suggesting that oxidant-mediated pathway might be involved in its processes. These results suggested that DEP activate NF-kappa B, which might be an important mechanism of its potential to increase the expression of inflammatory cytokines in vitro.

Acetylcysteine↗

Occurrence of monosialosyl pentahexaosylceramide GalNAc-GM1 as specific tumor-associated ganglioside of human head and neck squamous cell carcinomas.

In a recent study of the ganglioside profiles of human head and neck squamous cell carcinomas versus normal tissue, one unidentified GX ganglioside was found exclusively in tumor extracts, migrating between GM1 and GD3 by thin-layer chromatography. To determine the chemical structure of this ganglioside which accounted for 3-8% of the total gangliosides, the lipid samples were pooled and separated by high-pressure liquid chromatography to obtain individual ganglioside species purified to homogeneity. The tumor-associated GX ganglioside was analyzed by gas-liquid chromatography, mass spectrometry and immunostaining on thin-layer plates with mouse monoclonal antibodies after enzymatic cleavage. The data allowed the identification of GX ganglioside as GalNAc-GM1 that has been reported as a very minor brain ganglioside in humans. Thus, GalNAc-GM1 is a specific tumor-associated ganglioside in human head and neck squamous cell carcinomas that could be potentially valuable for clinicians.

Carcinoma, Squamous Cell↗

GT1b in human metastatic brain tumors: GT1b as a brain metastasis-associated ganglioside.

We studied ganglioside expression in 12 human metastatic brain tumors metastasized from colon (4), renal (3), lung (2), esophagus (1), pancreas (1), and mammary (1) carcinomas. GM3 was the major common ganglioside expressed in brain metastatic tumor tissues, and GT1b was also present in all the metastatic brain tumor tissues. The latter was identified by TLC-immunostaining and characterized structurally by secondary ion mass spectrometry combined with 'Far-Eastern blot'. The immunohistochemical analysis of frozen tissue sections confirmed localization of GT1b in the tumor cell membrane or cytosol. GT1b was shown to be expressed both in the primary colon carcinoma and the metastasis of a single patient by immunohistochemical procedure. In systemic carcinomas without brain metastasis, GM3 was a common major component, but no GT1b was detected. These findings indicate that GT1b is a brain metastasis-associated ganglioside. We speculate that the presence of GT1b would be a useful marker for estimating metastatic potentials to the brain.

Adenocarcinoma↗

Biphasic regulation of the development of murine type II collagen-induced arthritis by interleukin-12: possible involvement of endogenous interleukin-10 and tumor necrosis factor alpha.

OBJECTIVE: To examine the dose-specific effects of interleukin-12 (IL-12) on the evolution of murine type II collagen-induced arthritis (CIA). METHODS: From day 24 through day 33 following primary immunization, mice received daily intraperitoneal injections of murine recombinant IL-12. Measurements of anticollagen IgG, cytokines, and corticosterone were performed using enzyme-linked immunosorbent assay and radioimmunoassay. RESULTS: CIA mice injected with a low dose of IL-12 (5 ng/day) exhibited accelerated onset and increased severity of arthritis. In contrast, administration of a high dose of IL-12 (500 ng/day) attenuated arthritic inflammation. The low dose of IL-12 induced tumor necrosis factor alpha (TNFalpha) production, whereas the high dose induced production of both IL-10 and corticosterone and suppression of anticollagen antibody levels. Administration of neutralizing anti-TNFalpha and anti-IL-10 antibodies reversed the dose-specific effects of IL-12. CONCLUSION: IL-12 is an important immunomodulator during the pathogenesis of CIA. It appears to act by regulating humoral and cellular immune responses, as well as by mediating the expression of immunoregulatory cytokines and glucocorticoids.

Adjuvants, Immunologic↗

Isolation and characterization of a novel Forssman active acidic glycosphingolipid with branched isoglobo-, ganglio-, and neolacto-series hybrid sugar chains.

Equine kidney and spleen contain a Forssman active glycosphingolipid, and the structure of this glycolipid has been reported to be that of a globopentaosylceramide (GalNAcalpha-1,3GalNAcbeta-1,3Galalpha-1, 4Galbeta-1,4Glcbeta-1,1'Ceramide). We found that equine kidney contains several other anti-Forssman antibody-reactive glycosphingolipids. One of these acidic Forssman active glycosphingolipids was isolated and characterized by means of NMR, mass spectrometry, permethylation studies, and TLC-immunostaining. This glycolipid contains three moles of galactose, one mole of glucose, three moles of N-acetylgalactosamine, one mole of N-acetylglucosamine, and one mole of N-acetylneuraminic acid, and is stained on TLC with anti-Forssman antibodies and anti-GM2 ganglioside antibodies. HOHAHA and ROESY experiments and permethylation studies showed this glycolipid oligosaccharide to be branched at the innermost galactose; one chain has an isoglobo structure with a terminal Forssman disaccharide and the other chain is branched through the linkage of N-acetylglucosaminebeta-1,6 to the inner galactose. The nonreducing end of the GM2 trisaccharide is linked to this glucosamine. The structure of the oligosaccharide of the glycolipid presented here is a novel type, having branched isoglobo-, ganglio-, and neolacto-series oligosaccharides. Mass spectrometric analyses indicated the ceramide moiety of the glycolipid to be composed predominantly of hydroxy fatty acids (C20:0, C22:0, C23:0, C24:0, and C25:0) and hydroxysphinganine. GalNAcalpha-1,3GalNAcbeta-1,3Galalpha-1,3[GalNAcbet a-1, 4(NeuAcalpha-2,3)Galbeta-1,4GlcNAcbeta-1,6]Galbeta+ ++-1,4Glcbeta-1, 1'Ceramide

Animals↗

Macrophage inflammatory protein 1 alpha expression by synovial fluid neutrophils in rheumatoid arthritis.

OBJECTIVE: To determine the contribution made by synovial fluid (SF) neutrophils to the augmented expression of macrophage inflammatory protein 1 alpha (MIP-1alpha) in rheumatoid arthritis (RA). METHODS: Neutrophils were isolated from samples of SF from RA patients and peripheral blood (PB) samples from RA patients and healthy controls. Cell associated MIP-1alpha was visualised immunohistochemically, and cell associated MIP-1alpha as well as MIP-1alpha secreted into the SF was assayed by ELISA. Steady state expression of MIP-1alpha mRNA was assessed by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Freshly isolated SF neutrophils contained significantly higher concentrations of both MIP-1alpha protein and its transcript than PB neutrophils from either RA patients or healthy controls; incubation in the absence or presence of tumour necrosis factor alpha for 24 hours resulted in a significant increase in MIP-1alpha secretion by RA SF neutrophils compared with neutrophils obtained from either normal PB or RA PB; and expression of MIP-1alpha by SF neutrophils was well correlated with both RA disease activity and SF mononuclear cell (MNC) counts. CONCLUSION: Expression and secretion of MIP-1alpha by SF neutrophils may be indicative of local and systemic inflammation in RA. Moreover, this C-C chemokine may contribute to the recruitment of MNCs from the bloodstream into synovial joints and tissues.

Adult↗

Downregulation of intercellular adhesion molecule-1 expression on human synovial fibroblasts by endothelin-1.

OBJECTIVE: To study the effect of endothelin-1 (ET-1) on the expression of intercellular adhesion molecule-1 (ICAM-1) by synovial fibroblasts derived from individuals with rheumatoid arthritis (RA) or osteoarthritis (OA). METHODS: The expression of ICAM-1 protein and the abundance of ICAM-1 mRNA in synovial fibroblasts derived from individuals with RA or OA, or healthy controls, was assessed by flow cytometry and Northern blot analysis, respectively. mRNA expression of ET type A (ETA) and ET type B (ETB) receptors was assessed by reverse transcription polymerase chain reaction. RESULTS: Tumor necrosis factor-alpha (TNF-alpha) increased the expression of ICAM-1 by RA and OA fibroblasts. While ET-1 alone had no significant effect on ICAM-1 expression by either cell type, it inhibited the TNF-alpha induced increase in ICAM-1 expression, and this effect was more marked in RA fibroblasts. TNF-alpha also increased the amount of ICAM-1 mRNA in both cell types, and ET-1 inhibited this increase to a greater extent in RA fibroblasts than in OA fibroblasts. This inhibitory effect of ET-1 was reversed by addition of specific antagonist of ETA receptor. mRNA expression of ETA and ETB receptors was significantly greater in RA fibroblasts stimulated with TNF-alpha or even medium alone than in OA fibroblasts. CONCLUSION: These results suggest that ICAM-1 expression by fibroblasts is regulated not only by proinflammatory cytokines such as TNF-alpha and interleukin-1beta, but also by the vasoactive peptide ET-1, and that ET-1 may play an important role in inflammatory responses, especially in rheumatoid synovitis.

Aged↗

Decreased synthesis of glycosphingolipids in cells lacking vimentin intermediate filaments.

We are studying defects in glycosphingolipid synthesis in cells lacking vimentin intermediate filaments (vimentin-). Sugars can be incorporated into glycolipids whose ceramide is synthesized either de novo (pathway 1) or from sphingoid bases salvaged from hydrolysis of sphingolipids (pathway 2) and into glycolipids recycling from the endosomal pathway through the Golgi (pathway 3). Vimentin- embryonic fibroblasts, obtained from vimentin-knockout mice, incorporate less sugar into glycolipids than vimentin+ fibroblasts. Using two inhibitors of ceramide synthesis, beta-chloroalanine and fumonisin B1, we found the major defect in synthesis to be in pathway 2 and not in de novo synthesis. We used two additional approaches to analyze the functions of pathways 2 and 3. First, we used exogenous glucosylthioceramide ([14C]C8-Glc-S-Cer), a synthetic, nonhydrolyzable glycosphingolipid, as a precursor for synthesis of larger glycolipids. Vimentin- SW13 cells and embryonic fibroblasts glycosylated [14C]C8-Glc-S-Cer less extensively than their vimentin+ counterparts. Second, we used chloroquine to inhibit the hydrolysis of sphingolipids in endosomes and lysosomes. Chloroquine markedly decreased the incorporation of sugars into glycolipids larger than glucosylceramide. The defect in glycolipid synthesis in vimentin- cells probably results from impaired intracellular transport of glycolipids and sphingoid bases between the endosomal/lysosomal pathway and the Golgi apparatus and endoplasmic reticulum. Intermediate filaments may accomplish this function by contributing to the organization of subcellular organelles and/or by binding proteins that participate in transport processes.

Animals↗

Occurrence of an unusual phospholipid, phosphatidyl-L-threonine, in cultured hippocampal neurons. Exogenous L-serine is required for the synthesis of neuronal phosphatidyl-L-serine and sphingolipids.

We have recently reported that L-serine released from astroglial cells supports the survival and neuritogenesis of hippocampal neurons under a serum- and glia-free culture condition (Mitoma, J., Furuya, S., and Hirabayashi, Y. (1998) Neurosci. Res. 30, 195-199). In this study, we show that exogenous L-serine is required for the synthesis of phosphatidyl-L-serine (PS) and sphingolipids in hippocampal neurons. When hippocampal neurons were maintained under an astroglial cell-free condition, the levels of sphingolipids and phosphatidyl-L-serine in the neurons were greatly reduced in the absence of external L-serine or glycine. Instead, a novel phospholipid appeared just ahead of PS on TLC. This novel lipid was determined to be phosphatidyl-L-threonine by TLC blotting/negative secondary ion mass spectrometry and amino acid analysis. Biochemical studies on rat brain microsomes have indicated that phosphatidyl-L-threonine is synthesized by the base exchange enzyme that is involved in PS synthesis with much lower affinity, that is, approximately (1)/(150) of L-serine. Addition of L-serine or glycine to the culture medium restored the synthesis of PS and sphingolipids in the neurons. These observations show that hippocampal neurons require exogenous L-serine for the synthesis of PS and sphingolipids in the absence of astroglial cells and suggested that astroglial cells contribute to neuronal lipid synthesis through the supply of L-serine.

Animals↗

Antibodies to GT1a ganglioside in patients with Guillain-Barré syndrome.

Serum antibodies from 8 (13%) of 62 patients with the acute Guillain-Barré syndrome (GBS) and 1 of 3 patients with the Miller Fisher syndrome (MFS) recognized a minor ganglioside in bovine and human brain trisialoganglioside fractions. The ganglioside antigen migrated between GD1a and GD1b on thin-layer chromatograms. The structure of this ganglioside was established to be GT1a by thin-layer chromatography blotting and mass spectrometry. GT1a a ganglioside was also detected in human and bovine peripheral nerves by thin-layer chromatogram immunostaining. Serum from the GBS patients had IgM, IgG, or IgA antibodies against GT1a detectable by enzyme-linked immunosorbent assay (ELISA). Serum from the MFS patient also had elevated levels of IG against GT1a. None of the sera from 43 patients with other neurological diseases or from 24 healthy controls reacted with GT1a. Sera from 6 of 8 GBS patients with anti-Gt1a antibodies also reacted with GQ1b. There was no difference in the incidence of anti-GT1a immunoglobulins in acute GBS patients with or without oculomotor abnormalities. Levels of anti-GT1a antibodies correlated temporally wit clinical symptoms in GBS patients. Although the incidence of dysphagia was slightly higher in GBS patients with anti-GT1a antibodies than in those without, the number of patients studied may have been too small to detect an association between anti-GT1a antibodies and an a specific clinical variant of GBS. Our data demonstrate that a proportion of GBS patients have antibodies against GT1a ganglioside and suggest that these antibodies may play a role in the pathogenesis of neuropathy in GBS.

Adult↗

N-glycolylneuraminic acid-containing GM1 is a new molecule for serum antibody in Guillain-Barré syndrome.

To clarify the pathogenesis of Guillain-Barré syndrome (GBS) after parenteral injections of bovine brain gangliosides, we searched for new molecules in bovine brain gangliosides recognized by sera from GBS patients. Gangliosides fractionated in a Q-Sepharose column were used as the antigens, and the binding of serum IgG or IgM was examined by thin-layer chromatography/immunostaining. Fourteen of 175 serum samples from the patients reacted with the monosialoganglioside fraction 2. In the neutral solvent system, a band in this fraction migrated with N-acetylneuraminic acid-containing GM1 [GM1(NeuAc)], whereas in the alkaline solvent system it migrated slower. This suggested that the band was N-glycolylneuraminic acid-containing GM1 [GM1(NeuGc)]. In both solvent systems, its mobility was almost the same as that of authentic GM1(NeuGc) from mouse liver. Secondary ion mass spectrometry showed that the ganglioside's structure was consistent with that of GM1(NeuGc). IgG anti-GM1(NeuGc) antibodies in sera from the GBS patients were significantly absorbed by GM1(NeuAc), indicative that the anti-GM1(NeuGc) antibodies cross-react with GM1(NeuAc). N-Glycolylneuraminic acid-containing gangliosides are so highly immunogenic in humans that the injection of GM1(NeuGc) could induce the production of IgG anti-GM1(NeuGc) antibody, which cross-reacts with GM1(NeuAc).

Animals↗

The possible role of interleukin (IL)-12 and interferon-gamma-inducing factor/IL-18 in protection against experimental Mycobacterium leprae infection in mice.

Cell-mediated immunity participates in host defense against mycobacterial infection. Both interleukin 12 (IL-12) and interferon-gamma-inducing factor (IGIF/IL-18), produced mainly by macrophages, play a critical role in expression of cell-mediated immunity. To investigate the role of IL-12 and IGIF/IL-18 in vivo, we examined cytokine profile, bacterial growth, and the potential benefit of cytokine therapy in susceptible and resistant mice infected with Mycobacterium leprae. The early expression of IL-12 p40 and IGIF/IL-18 at the site of inoculation was found in resistant mice 3-72 h after the infection, but not in susceptible mice. Both strains of mice did not show expression of IFN-gamma and IL-4. IL-12 administration resulted in a significant reduction of bacterial counts in mice with established M. leprae infection. The results imply that susceptible mice exhibit decreased expression of type 1 helper T (Th1) response without reciprocal increased Th2 response and show responsiveness to exogenous IL-12. IL-12 therapy may be a possible rationale for treatment of M. leprae infection.

Animals↗

Interleukin-13 down-regulates the expression of neutrophil-derived macrophage inflammatory protein-1 alpha.

OBJECTIVE AND DESIGN: To determine whether interleukin-13 (IL-13) possesses anti-inflammatory properties with respect to polymorphonuclear neutrophils (PMNs). Effects of IL-13 on production of the chemokine, macrophage inflammatory protein-1 alpha (MIP-1alpha), by PMNs were analyzed. SUBJECTS: Human peripheral blood PMNs obtained from healthy volunteers. METHODS: PMNs were stimulated by lipopolysaccharide (LPS) and/or IL-13 for selected periods of time, and MIP-1alpha expression was assessed by ELISA and Northern blot analysis. RESULTS: IL-13 suppressed expression and production of PMN-derived MIP-1alpha mRNA and protein in a dose- and time-dependent manner. Inhibition of protein synthesis caused significant enhancement of MIP-1alpha mRNA expression. The inhibitory activity of IL-13 was abrogated, however, in the presence of cycloheximide, suggesting that IL-13's effect was via synthesis of de novo repressor protein(s). CONCLUSIONS: PMN-derived chemokines are regulated by both proinflammatory and immunomodulatory cytokines. The coordinated production of these substances is likely to be important in the orchestration of inflammatory and immune responses.

Blotting, Northern↗

Analysis of glycosphingolipids of human head and neck carcinomas with comparison to normal tissue.

Glycosphingolipids of head and neck carcinomas from six tumor-bearing patients were analyzed and compared to those of normal tissue from similar areas. The total glycosphingolipid content and the lipid-bound sialic acid were much higher in carcinomas than in normal tissue. Major neutral glycolipids were glucosylceramide, lactosylceramide, trihexosylceramide and paragloboside. Sulfatides were seen only in extracts from normal tissue which also showed a rather simple ganglioside pattern with #GM3 and GD3 as major species, whereas tumors showed additional species such as GM2 and GD2, along with a strong increase in LM1, GM1, GD1a and GT1b.

Biomarkers, Tumor↗

Effects of chroman derivatives on platelet aggregation induced by some aggregating agents in rabbits.

1. We synthesized 10 chroman derivatives (CD-1 to CD-10) derived from khellactone, including praeruptorin A and praeruptorin B and examined the effects of these compounds on rabbit platelet aggregation. 2. These compounds exhibited an inhibitory effect on platelet-activating factor (PAF)-induced platelet aggregation and their effects were more potent on PAF-induced platelet aggregation than on adenosine triphosphate (ADP)-, arachidonate (AA)- or collagen-induced platelet aggregation. In particular, (+/-)-cis-5-methoxy-6-methoxycarbonyl-2,2-dimethyl-3,4-ditiglyloxychr oman (CD-6), (+/-)-cis-5-methoxy-6-(2-methoxycarbonylethenyl)-2,2-dimethyl- 3,4-ditiglyloxychroman (CD-8), (+/-)-cis-3,4-diacetoxy-5-methoxy-2,2-dimethyl-6-propylchroman (CD-9) and (+/-)-cis-5-methoxy-2,2-dimethyl-6-propyl-3,4-ditiglyloxychroman (CD-10) showed a moderate inhibition of PAF-induced platelet aggregation. 3. From these findings, it is suggested that compounds with potent PAF antagonist activities have the following features: (i) a tiglyloxy moiety is required at the 3 and 4 positions; and (ii) the methoxy moiety is also required at the 5 position of chroman skeleton in khellactone.

Adenosine Diphosphate↗

Roxithromycin inhibits cytokine production by and neutrophil attachment to human bronchial epithelial cells in vitro.

We evaluated the effect of roxithromycin on cytokine production and neutrophil attachment to human airway epithelial cells. Roxithromycin suppressed production of interleukin 8 (IL-8), IL-6, and granulocyte-macrophage colony-stimulating factor. It inhibited neutrophil adhesion to epithelial cells. Roxithromycin modulates local recruitment and activation of inflammatory cells, which may have relevance to its efficacy in airway diseases.

Anti-Bacterial Agents↗

Pharmacological activities of khellactones, compounds isolated from Peucedanum japonicum THUNB. and Peucedanum praeruptorium DUNN.

The spasmolytic and antiallergic effects of AA and BB, compounds isolated from Peucedanum japonicum THUNB. (P. japonicum THUNB.) and Peucedanum praeruptorium DUNN. (P. praeruptorium DUNN.), were investigated in isolated smooth muscle and rat PCA. AA and BB showed noncompetitive antagonistic effects on Ach- and histamine-induced contraction in the isolated guinea pig ileum. Both AA and BB at 10(-6) g/ml caused a slight shift to the right of the dose-response curve for Ca2+ in isolated guinea pig ileum, and a concentration up to 3 x 10(-6) g/ml displayed noncompetitive antagonistic effects. The Ba2+ (3 x 10(-4) g/ml)-induced contraction in ileum and the histamine (10(-3) g/ml)-induced contraction in trachea were obtained to relaxation by AA and BB in a concentration-dependent fashion. AA and BB showed noncompetitive antagonist action on serotonin-induced contraction of the rat uterus excised 24-48 h after subcutaneous injection of female rats with estradiol. But, AA and BB were found to have hardly any inhibitory effect on rabbit thoracic aorta contractions induced by epinephrine (3 x 10(-6) g/ml). When the effect of oral administration of 40 mg/kg dose of BB was tested on the rat homologous PCA using anti-egg albumin mouse serum dilutions (1:100, 1:250, 1:500 and 1:750), it inhibited the 1:750 serum reaction 42.6%, but the inhibition rates for the other dilutions were 12-20%. Thus, based on the results of testing AA and BB, compounds isolated from P. japonicum THUNB. and P. praeruptorium DUNN. were confirmed to possess a spasmolytic effect on different types of smooth muscle and a mild antiallergic effect. These findings are of interest in regard to the medical uses of P. japonicum THUNB. and P. praeruptorium DUNN. as a herbal drug for bronchial asthma, spasmolytic effect, etc.

Animals↗