Biomedical subjects

G Soma

Publications and source records attributed to G Soma.

At least 19 recordsLinked to original sources

PubMed2001

Cloning and characterisation of tandem-repeat type galectin in rainbow trout (Oncorhynchus mykiss).

Fish beta-galactoside binding lectin (galectin) cDNA was cloned from the cDNA library of rainbow trout (Oncorhynchus mykiss) head kidney. The clone contained a single open reading frame encoding 341 amino acids (aa) (38 kDa protein), including the initiator methionine. Significant sequence homology to mammalian galectin-9 (40-55% identity) was observed. Its amino acid sequence showed two distinct N- and C-terminal domains (148 and 130 aa, respectively) connected by a peptide linker (63 aa). The galectin contains two consensus WG-E-R/K motifs thought to play an essential role in sugar-binding, indicating that this lectin is a member of the tandem-repeat type galectins which have not been identified in fish. The 1.6 kDa mRNA of the lectin was found by Northern blot analyses to be widely expressed in the spleen, head kidney, thymus, peritoneal exudate cells, ovary, gills and heart. Southern blot analyses with the probe for C-terminal of the lectin showed the existence of two hybridising genes. These results suggest that rainbow trout has at least one tandem-repeat type galectin as well as proto-type galectin.

Amino Acid Sequence↗

PubMed2001

Tumor necrosis factor alpha (TNFalpha)-like factor produced by macrophages in rainbow trout, Oncorhynchus mykiss.

The presence of a Tumor Necrosis Factor alpha (TNFalpha)-like molecule has been suggested in fish by biological assays and biological and antigenic cross-reactivities with human TNFalpha. In the present study, whether rainbow trout macrophages produce TNFalpha was examined. Murine recombinant TNFalpha (m-rTNFalpha) was used as the standard mammalian TNFalpha. The supernatants were harvested from trout macrophage culture stimulated with lipopolysaccharide (LPS) and then passed through a Polymyxin B column to remove LPS. Results show that trout macrophage culture supernatants exhibit TNF-like activities. The supernatants significantly enhanced neutrophil migration and macrophage respiratory burst activity as assessed by NBT reduction test. The supernatants were also highly cytotoxic to murine L929 cells, which are known to be sensitive to mammalian TNFalpha. The biological activities of TNF in the trout macrophage culture supernatant was determined as 2.6 U ml(-1) in the presence of actinomycin D. This indicates biological cross-reactivity of trout TNFalpha-like factor on mammalian cells. Moreover, these activities were inhibited by a rabbit anti-mTNFalpha antibody. These results suggest that rainbow trout macrophages produce a TNFalpha-like factor that is similar to the mammalian TNFalpha in functions.

Animals↗

PubMed2001

Expression of nuclear factor-kappa B, tumor necrosis factor receptor type 1, and c-Myc in human astrocytomas.

Tumor necrosis factor receptor type 1 (TNFR1) and c-Myc are important in signal transduction in tumor necrosis factor-alpha (TNF-alpha)-induced cytotoxicity, whereas activation of nuclear factor-kappa B (NF-kappa B) protects against TNF-alpha-induced apoptosis. This study investigated the expression of NF-kappa B, TNFR1, and c-Myc in human astrocytoma tissues by reverse transcriptase-polymerase chain reaction (PCR) and immunohistochemical analysis. TNFR1 messenger ribonucleic acid (mRNA) and c-Myc mRNA were frequently expressed in malignant astrocytomas, especially in glioblastomas, compared with low-grade astrocytomas by PCR analysis. TNFR1 and c-Myc mRNAs were barely detectable in normal brain tissues. NF-kappa B p50 and p65 subunit mRNAs were detected in various grades of astrocytomas, with frequent expression in malignant astrocytomas. The presence of activated NF-kappa B was confirmed by nuclear localization in neoplastic astrocytes as determined by immunohistochemistry. Both p50 and p65 subunits were inhomogeneously expressed in neoplastic astrocytes of glioblastoma, but only in a few scattered tumor cells in low-grade astrocytoma, and almost undetectable in normal brain tissues. These results indicate that TNFR1 and c-Myc are overexpressed in malignant astrocytomas, and this may increase the cellular sensitivity to the cytotoxic action of TNF-alpha. NF-kappa B p50 and p65 were simultaneously induced and activated in malignant astrocytomas. Our results suggest that the constitutive activation of NF-kappa B subunits in malignant astrocytoma, especially in glioblastoma, could be associated with the resistance to TNF-alpha immunotherapy, and indicates new therapeutic strategies for malignant astrocytomas.

Antigens, CD↗

PubMed1998

Involvement of 26-kDa membrane-bound tumour necrosis factor precursor in bidirectional feedback regulation on 17-kDa tumour necrosis factor production after stimulation by lipopolysaccharide.

The authors have previously shown that 26-kDa membrane-bound tumour necrosis factor precursor (proTNF) on the cell-surface of primed human monocytic cell line THP-1 is involved in positive feedback regulation of lipopolysaccharide (LPS)-dependent TNF-production. Here, we provide direct evidence for modulation of responsiveness of the THP-1 cells against LPS by membrane-bound pro-TNF. When THP-1 cells were cocultivated with a heterogeneous cell line (proTNF/3T3 cells) which constitutively expressed membrane-bound proTNF, LPS-dependent TNF-production by THP-1 cells was significantly suppressed and the normal level was restored by the presence of anti-TNF antibody during cocultivation. The proTNF-3T3-induced decline of TNF-production of THP-1 was observed primarily at the mRNA level, although no difference was observed in the mRNA level of interleukin 1 beta, another LPS-inducible cytokine. These results suggest that proTNF could also be involved in the negative feedback regulation of LPS-dependent TNF-production through cell-to-cell contact. The augmentation of LPS-dependent TNF-production accompanied by the production of endogenous proTNF induced by exogenous agent was inhibited by protein kinase C inhibitor, whereas proTNF/3T3-induced suppression of TNF-production could not be restored to the normal level. It thus seems possible that proTNF might act on macrophages as a bidirectional regulator of its production by THP-1 cells depending on co-induced signals.

3T3 Cells↗

PubMed1998

A large number of tandem repeats in the polymorphic epithelial mucin gene is associated with severe acne.

Polymorphic epithelial mucin (PEM) or MUC1 is a glycoprotein secreted from various epithelial gland tissues. In skin, PEM is detected in sweat glands and sebaceous glands by the DF3 monoclonal antibody. The gene of PEM includes an allele exhibiting length polymorphism due to a variable number of tandem repeats (VNTR); this is expressed co-dominantly, which may influence the microenvironment of the skin. The allelic size variation of the PEM gene was investigated in Japanese acne patients, atopic dermatitis patients, and healthy controls. The frequency of longer length alleles was significantly higher in severe acne patients.

Acne Vulgaris↗

PubMed1997

Structural characterization of lipid A obtained from Pantoea agglomerans lipopolysaccharide.

Lipopolysaccharide isolated from Pantoea agglomerans showed higher priming and triggering activities for macrophages in terms of tumor necrosis factor production than other lipopolysaccharides. To identify the difference in biological activities of lipopolysaccharide of Pantoea agglomerans from other lipopolysaccharides on the basis of structure, we determined the structure of the lipid A part, which is the biological center of lipopolysaccharides, by quantitative analysis, nuclear magnetic resonance spectroscopy and mass spectrometry. Lipopolysaccharide of Pantoea agglomerans is constructed with at least two kinds of lipid A of different levels of acylation. One is of the same type as that of Escherichia coli with hexa-acyl lipid A and the other is the Salmonella minnesota type with hepta-acyl lipid A.

Bacterial Proteins↗

PubMed1996

Mechanistic analysis of high antitumor effect of intradermal administration of lipopolysaccharide from Pantoea Agglomerans.

Lipopolysaccharide from Pantoea Agglomerans (LPSp) has a remarkably high antitumor activity even against poorly immunogeneic tumors when given by intradermal injection combined with cyclophosphamide (CY). We have extended this study to gain an insight into the mechanism of this antitumor effect, and especially into the induction of cell mediated immunity. In immunohistological studies, extensive necrosis and marked infiltration of the inflammatory cells at the tumor were observed after intradermal injection of LPSp combined with CY, but not after CY alone or after no treatment. The cells around the tumors were mostly neutrophils and macro phages (Mac 1+); T cells (CD4+, CD8+) were also present. The serum levels of cytokines, induced after intradermal injection of LPSp, were determined and compared with intravenous administration of LPSp or recombinant TNF-SAM2. TNF-alpha, IL-1, IL-6 and GM-CSF were measured by ELISA as a marker of cytokine induction. The peak level of TNF-alpha induced by intradermal injection of LPSp was about 5000 pg ml-1, which was considered relatively small since this level was observed even in clinical trial. There seems to be a longer period of release of TNF-alpha after an intradermal injection than after an intravenous injection. This may produce the remarkably high antitumor effect of the intradermal injection. The antitumor effect of intradermal administration combined with CY was evaluated in nude mice to clarify the role of T cells in high antitumor activity. In this experiment, antitumor activity was found to be much less in BALB/c nu/nu mice without regression, while complete regression was frequently observed in syngeneic mice, showing the crucial role of T cells in this treatment. These observations suggest that intradermal administration of LPSp in combination with CY continuously releases and induces not only extensive necrosis of the tumor but also cell mediated antitumor immunity, which may be indispensable for complete regression of the tumor. Clinical application of this treatment for advanced cancer patients is in progress.

Animals↗

PubMed1996

Surgical experience of total anomalous pulmonary venous connection with mid-term follow-up in a developing country.

OBJECTIVE: To illustrate the incidence, the different age group, varied clinical presentation, incremental risk factors for surgery and follow-up results from this part of the world. EXPERIMENTAL DESIGN: Retrospective study with follow-up from 3 months to 5 years. SETTING: Institutional practice with hospitalised care. SELECTION PROCEDURE: Hospitalised patients with a diagnosis of total anomalous pulmonary venous connection. INTERVENTIONS: All patients who were diagnosed to have total anomalous pulmonary venous connection underwent corrective surgery. RESULTS: There were 20 hospital deaths postoperatively. The mean follow-up was 1.9 year. Logistic regression analysis identified age group, timing of surgery, associated anomalies preoperative symptoms, anatomical type of lesion, pulmonary artery hypertension, duration of ventilation, low cardiac output as risk factors for surgery. The mean survival time was 4-8 years. CONCLUSION: Mortality continues to be higher from this part of the world due to severe malnourishment, late presentation. Sociodemographic factors also play a major role in affecting surgical outcome apart from the identified risk factors for surgery.

Cardiac Surgical Procedures↗

PubMed1995

Molecular cloning of a cDNA that encodes the precursor to several exogastrula-inducing peptides, epidermal-growth-factor-related polypeptides of the sea urchin Anthocidaris crassispina.

Complementary DNA clones for exogastrula-inducing peptides (EGIPs) of the sea urchin Anthocidaris crassispina, which are related to epidermal growth factor (EGF), were obtained from a cDNA library of late gastrula embryos using, as probe, the partial cDNA for one of the EGIP (EGIP-D) obtained by the reverse-transcription PCR method. The longest cDNA was composed of 1662 bp, and encoded a protein of approximately 36 kDa with a region that resembled a signal sequence. The deduced protein contains the sequences of EGIP-C, EGIP-D, and EGIP-A in that order, followed by the sequence for an unidentified EGIP-like polypeptide. When expressed in Escherichia coli as a fusion protein with beta-galactosidase, the product for the cDNA was specifically recognized by a rabbit antibody raised against EGIP-D that had been purified from embryos. Characteristic amino acid residues were found around the N-terminus and the C-terminus of each EGIP sequence, suggesting a specific processing mechanism for the generation of the individual EGIPs from the precursor. RNA-blot analysis revealed the presence of EGIP mRNA in unfertilized eggs. The level of this mRNA decreased gradually after fertilization, began to increase dramatically after the onset of gastrulation, and continued to increase through the pluteus stage. Genomic Southern-blot analysis suggested that this gene is present as a single copy. A homology search showed that the EGIP cDNA has a similarity to the cDNA for SpEGF2 which was cloned as a gastrula-specific gene in another sea urchin, Strongylocentrotus purpuratus.

Amino Acid Sequence↗

PubMed1995

Inducibility of endogenous tumor necrosis factor by tumor cells from colorectal tumor patients at Dukes stage C as a novel prognostic factor following curative operation.

PURPOSE: It is well known that tumor cells secrete endogenous tumor necrosis factor (en-TNF) as a cytokine when stimulated with lipopolysaccharide (LPS). We, therefore, analyzed the biologic role of en-TNF secreted by tumor cells themselves to learn the prognosis of patients and the susceptibility of tumors to biologic response modifiers in particular. METHODS: Patients with Dukes C colorectal tumors were studied after curative operation to determine the inducibility of en-TNF by their primary cultured cells in response to LPS. RESULTS: Irrespective of the known clinicopathologic factors of the tumors, en-TNF was produced in 21 of a total of 44 patients. The group of patients with clear en-TNF production showed a significantly lower incidence of recurrence and/or metastasis and a higher survival rate than the group without en-TNF production, suggesting a strong correlation between patient prognosis and inducibility of en-TNF. CONCLUSION: Inducibility of en-TNF by tumor cells themselves can be a novel prognostic factor for patients with colorectal tumor, especially of Dukes Stage C.

Biomarkers↗

PubMed1995

Hemodynamic evaluation of recombinant human tumor necrosis factor (TNF)-alpha, TNF-SAM2 and liposomal TNF-SAM2 in an anesthetized dog model.

We have evaluated the hemodynamic effects of systemically administered recombinant human tumor necrosis factor (TNF)-alpha, TNF-SAM2 and liposome-bound TNF-SAM2 in an anesthetized mongrel dog model. A dose of 10 micrograms TNF protein/kg of each formulation was injected in a peripheral vein and mean systemic arterial pressure (SAP), heart rate (HR) and cardiac output (CO) were measured. TNF-alpha induced a marked drop in SAP in all three dogs (mean decrease = 59.3 +/- 5.2 mm Hg; to 61.5% of baseline; p = 0.008); whereas TNF-SAM2 caused a smaller and transient drop in SAP in four dogs (mean decrease = 25.5 +/- 10.1 mm Hg; to 81.2% of baseline; p = 0.086). In three dogs administered liposome-bound TNF-SAM2, which retains antitumor activity in vivo, a net slight hypertensive phase and sustained elevated CO occurred, followed by a return to an essentially normotensive state (101.0% of baseline SAP). This model demonstrates that the principal acute systemic toxicity of TNF, i.e., hypotension, can be markedly attenuated by liposomal formulation of a second-generation TNF.

Animals↗

PubMed1995

Formulation and antitumor efficacy of liposomal-caprylated-TNF-SAM2.

The tumor necrosis factor (TNF) mutant TNF-SAM2 has previously been shown to have a therapeutic profile superior to parental TNF. To initially evaluate the characteristics of liposomal formulations of TNF-SAM2, it was modified with the N-hydroxysuccinimide ester of caprylic acid to increase its hydrophobic binding to multilamellar and small unilamellar vesicles (MLVs and SUVs). Native PAGE and fluorescamine analysis of acetylated parental TNF and TNF-SAM2 indicated that these proteins both displayed trimeric structures based on crosslinking/SDS-PAGE analysis and behaved similarly with respect to reactivity of their amino functions. Limited N-terminal sequencing analysis of partially acetylated (approx 3 acetyl groups per trimer) TNF-SAM2 indicated that the N-terminal Val was not modified; this was also concluded based on HPLC/mass spectrometric (LC-MS) analysis of Glu C digests. LC-MS analysis of tryptic digests of the acetylated TNF-SAM2 indicated that Lys-98 was unreactive. Molecular ions corresponding to acetylated Lys-containing peptides for all five other Lys residues could be detected; none appeared hyperreactive, but Lys-11 appeared hyporeactive. MLVs composed of DMPC/DMPG (7:3) and SUVs composed of DPPC/DSPC (1:1) displayed high capacity for binding to caprylated TNF-SAM2. These formulations of caprylated TNF-SAM2 displayed tumor necrotizing and growth-inhibitory activity in a syngeneic tumor model, and may be candidates for clinical development.

1,2-Dipalmitoylphosphatidylcholine↗

PubMed1994

Antinociceptive effect of lipopolysaccharide from Pantoea agglomerans on streptozotocin-induced diabetic mice.

The antinociceptive effect of lipopolysaccharide from Pantoea agglomerans (LPSp) in streptozotocin-induced diabetic mice was examined. Although subcutaneous (s.c.) administration of LPSp produced a dose-dependent inhibition of the tail-flick response in both non-diabetic and diabetic mice, the antinociceptive response was greater in diabetic mice than in non-diabetic mice. The antinociceptive effects of LPSp in both diabetic and non-diabetic mice were significantly antagonized by s.c. administration of naltrindole, a selective delta-opioid receptor antagonist or nor-binaltorphimine, a selective kappa-opioid receptor antagonist, but not by beta-funaltrexamine, a selective mu-opioid receptor antagonist. These results suggest that LPSp produces a marked antinociceptive effect in diabetic mice through the activation of delta- and kappa-opioid receptors.

Analgesics↗

PubMed1994

Constitutive expression of TNF-alpha and -beta genes in mouse embryo: roles of cytokines as regulator and effector on development.

1. Using the RT/PCR method, we examined mRNA expression of several inflammatory factors in mouse embryos during mid-late embryonal development. mRNAs of tumor necrosis factor (TNF)-alpha, TNF-beta, their receptors (TNF-RI, TNF-RII), transforming growth factor (TGF)-beta, were expressed constitutively in most of the embryonic tissues. 2. While mRNAs of other factors, interleukin (IL)-1 alpha, IL-1 beta, IL-3, IL-6, granurocyte-colony stimulating factor (G-CSF), leukaemia inhibitory factor (LIF), and interferon (IFN)-gamma were only limitedly expressed. 3. The mRNAs of several complement components (C2, C3, C4, C5) and receptors (CR1, CR2) were also detected. Among them, the expression of C3 and CR1 were prominent. These results strongly support our idea that inflammation-like system play an important role to regulate embryogenesis.

Animals↗

PubMed1994

Effects of a lipopolysaccharide from Pantoea agglomerans on the cocaine-induced place preference.

A lipopolysaccharide from Pantoea agglomerans (LPSp) was purified, and its effect on the cocaine-induced place preference was examined in rats. Cocaine (4 mg/kg, i.p.) produced a significant place preference. Administration of LPSp (5-1000 micrograms/kg, i.p.) alone resulted in neither preference nor aversion for either the drug- or saline-associated place. However, pretreatment with LPSp (500 and 1000 micrograms/kg, i.p.) abolished the place preference that had been induced by cocaine. Furthermore, treatment with LPSp (500 micrograms/kg, i.p.) abolished cocaine (20 mg/kg, i.p.)-induced locomotor enhancement in mice. These results suggest that while LPSp itself may possess neither reinforcing nor locomotor enhancing effects, it blocks both the reinforcing and the locomotor enhancing effects of cocaine. Therefore, LPSp might be useful in pharmacotherapy for prevention of recurrent cocaine abuse.

Animals↗

PubMed1994

Antitumor effect of exogenous/endogenous TNF (EET) therapy with cyclophosphamide on C6 glioma in rat.

We earlier reported that endogenous TNF could be induced in mice as well as in patients by successive administration of exogenous TNF as a primer and OK-432 as a trigger, and we termed this exogenous/endogenous TNF (EET) therapy. We studied the effect of EET therapy with cyclophosphamide (CY) on tumor-transplanted rats. In order to induce endogenous TNF, 5 x 10(5) U/kg of recombinant human TNF-S(AM2) (rTNF; 5.6x10(6) U/mg protein) was injected intravenously (iv) as a primer followed by injection of 25 KE/kg of OK-432 as a trigger. TNF activity induced in serum was about 500 U/ml. Only 1 U/g of TNF was detected in the brain. To evaluate the antitumor effect, C6 glioma cells (1.6 x 10(4) cell/5 microliters) was transplanted into the brain. On day 7 of the transplantation, the rats were administered iv with CY (75 mg/kg), treated with EET therapy 7 days thereafter, and survival days were checked. No clear difference in survival days was observed between the rats treated with the EET and the control group. Three rats out of 6 treated with CY survived for more than 40 days, and all the rats treated with the combination of CY and EET continued to survive. The histological examination on day 44 revealed necrotic changes at the tumor lesions in all of the surviving rats, and the animals were evaluated as completely cured. These results suggest that applied treatment based on the EET therapy will be also effective against malignant brain tumors.

Animals↗

PubMed1994

Suppression of hyperalgesia in streptozotocin-induced diabetic mice by a lipopolysaccharide from Pantoea agglomerans.

The ability of a lipopolysaccharide from Pantoea agglomerans (LPSp) to relieve hyperalgesia was examined by observing its inhibition of the decrease in the threshold for nociceptive perception, as determined by the tail-pinch test, in streptozotocin-induced diabetic mice. Subcutaneous injection of LPSp suppressed hyperalgesia in streptozotocin-induced diabetic mice and also exerted a therapeutic effect on hyperalgesia in these animals. The present data suggest that LPSp may be effective in relieving the pain associated with diabetic neuropathy.

Animals↗

PubMed1993

Fc gamma receptor-mediated biological activities of human leukemic cell lines and their modulation by transforming growth factor-beta 1 and interleukin 6.

Previously we reported that transforming growth factor-beta 1 (TGF-beta 1) remarkably enhanced the differentiation of human leukemic cell lines, HL-60 and THP-1, in the presence of 1 alpha,25-dihydroxyvitamin D3 (VD3) and also that it induced Fc receptor for immunoglobulin G (Fc gamma R), type IIIB, in the presence of retinoic acid (RA). The present study revealed that TGF-beta 1 enhanced the Fc gamma RI- and Fc gamma RII-mediated antibody-dependent cellular cytotoxicity (ADCC) of the cells differentiated in the presence of VD3 and RA. However, production of active oxygen molecules was suppressed by TGF-beta 1. On the other hand, IL-6 stimulated production of active oxygen molecules and ADCC of the cells treated with VD3 and tumor necrosis factor-alpha (TNF-alpha). Furthermore, the levels of cell surface Fc gamma RI and Fc gamma RII were not clearly correlated with the ADCC. The TGF-beta 1/VD3-treated HL-60 cells were able to synthesize mRNAs for TGF-beta 1 and TNF-alpha, although TNF-alpha protein was not detectable. These results suggest that TGF-beta 1 has a bifunctional role, either stimulatory or inhibitory, in the modulation of macrophage activities through Fc gamma Rs and that IL-6 stimulates certain macrophage activities in mature cells.

Antibody-Dependent Cell Cytotoxicity↗