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Biomedical subjects

Kuniyasu Soda

Publications and source records attributed to Kuniyasu Soda.

6 recordsLinked to original sources
PubMed2006

Increased blood spermine levels decrease the cytotoxic activity of lymphokine-activated killer cells: a novel mechanism of cancer evasion.

Increased blood polyamine levels, often observed in cancer patients, have negative impacts on patient prognosis and are associated with tumor progression. The purpose of our study was to examine the effects of polyamines on cellular immune function. Peripheral blood mononuclear cells (PBMCs) from healthy volunteers were cultured with the human natural polyamines spermine, spermidine, or putrescine, and the effects on immune cell function were examined. The correlation between post-operative changes in blood polyamine levels and lymphokine-activated killer (LAK) activity was also examined in cancer patients. Spermine decreased the adhesion of non-stimulated PBMCs to tissue culture plastic in a dose- and a time-dependent manner without affecting cell viability or activity. This decrease in adhesion capacity was accompanied by a decrease in the number of CD11a bright-positive and CD56 bright-positive cells. Upon stimulation with interleukin 2 to activate LAK cytotoxicity, PBMCs cultured overnight with 100 or 500 microM spermine showed decreased cytotoxic activity against Daudi cells (91.5 +/- 1.7 and 84.9 +/- 3.0%, respectively (n = 6) compared to PBMC cultured without polyamines). In a group of 25 cancer patients, changes in blood spermine levels after surgery were negatively correlated with changes in LAK cytotoxicity after surgery (r = -0.510, P = 0.008: n = 25). Increased blood spermine levels may be an important factor in the suppression of anti-tumor immune cell function.

Cell Adhesion↗
PubMed2005

Erythropoietin attenuates cachectic events and decreases production of interleukin-6, a cachexia-inducing cytokine.

In cancer cachexia, erythropoietin often yields beneficial therapeutic effects by improving patient's metabolic and exercise capacity via an increased erythrocyte count. However, erythropoietin also has counter-regulatory effects against pro-inflammatory cytokines, which are postulated to be mediators of cancer cachexia. We investigated the mechanisms by which erythropoietin improves the cachectic condition. In this study, 100 Units/day of erythropoietin were administered intraperitoneally to BALB/c male mice, carrying a subclone of colon 26 adenocarcinoma, beginning on the day after tumor inoculation and continuing until they died. Erythropoietin administration attenuated the decline in body weight, as well as the decline in fat and muscle weights, of tumor-bearing mice, but improved the survival of cachectic mice. Mice receiving erythropoietin had increased erythrocyte and platelet counts, but significantly decreased white blood cell count. In addition, erythropoietin administration significantly decreased interleukin-6 levels, not only in serum but also in the inoculated tumor. These results indicate that the positive therapeutic effects of erythropoietin on cancer cachexia are due, not only to improving metabolic and exercise capacity via an increased erythrocyte count, but also to attenuation of cachectic manifestations by decreased production of the cachexia-inducing cytokine, interleukin-6.

Adenocarcinoma↗
PubMed2005

Spermine, a natural polyamine, suppresses LFA-1 expression on human lymphocyte.

Natural polyamines, spermine, spermidine, and putrescine, play a pivotal role in the regulation of gene expression; therefore, the age-dependent decreases and the disease-dependent increases in polyamine synthesis suggest a possible contribution of polyamines to the age-related and disease-associated changes in cellular function. In this study, we examined the effects of polyamines on the cellular function and the expression of adhesion molecules on human PBMCs from healthy volunteers. Flow cytometry revealed that PBMCs cultured with spermine decreased mean fluorescent intensities (MFIs) of CD11a and CD18 in the lymphocyte light-scattered region, but not in the monocyte region. This suppression was observed in a dose- and time-dependent manner and found nonspecifically on all cell subsets we tested (CD3(+), CD4(+), CD8(+), CD19(+), CD45RA(+), CD45RO(+), CD4(+)CD45RA(+), CD4(+)CD45RO(+), CD8(+)CD45RA(+), CD8(+)CD45RO(+)). The decreases of CD11a and CD18 MFIs were accompanied by the decrease in adherent capacity of PBMCs to HUVECs. Spermine did not hinder cell activities or cell viability. Among 42 healthy volunteers (mean, 49.5 years old; from 26 to 69), blood spermine levels inversely correlated with the CD11a MFIs of cells in the lymphocyte region (r = -0.48; p = 0.001), but not with those in the monocyte region. The effects of spermidine seemed weaker than those of spermine, and blood spermidine levels had no correlation with CD11a MFIs of the lymphocyte region. Putrescine had no effect on the expressions of membrane molecules. Polyamines, especially spermine, decrease LFA-1 (CD11a/CD18) expression on human lymphocyte and adhesion capacity of PBMCs to HUVECs.

CD11a Antigen↗
PubMed2004

Biclonal extramedullary plasmacytoma arising in the peritoneal cavity: report of a case.

We report a rare case of extramedullary plasmacytoma, which arose either in the ileum or the ileal mesentery. A 70-year-old woman presented with a high fever and symptoms of bowel obstruction. Computed tomography and magnetic resonance imaging showed a large heterogeneous tumor in the peritoneal cavity. Serum immunoelectrophoresis revealed a biclonal increase of IgA-Kappa and IgG-Kappa. At surgery, we found that the parenchyma of the fragile tumor had firm communication with the ileal mesentery, and the cavity of the tumor communicated with the ileal lumen. After a temporary regression following surgery and chemotherapy, the tumor grew rapidly. Although there was no evidence of progression to multiple myeloma, the patient died of cachexia less than 4 months after surgery.

Aged↗
PubMed2003

Excessive increase of serum interleukin 6 jeopardizes host defense against multi-bacterial infection.

Serum interleukin 6 (IL-6) is elevated among patients who have undergone surgery, trauma, and thermal injury. It is well known that the greater the increase of serum IL-6, the higher the incidence of post-injury morbidity and mortality is. However, it has not been determined whether the physiological effects of IL-6 increase the rate of morbidity and mortality or if IL-6 is just a bystander that only indicates the severity of the injury. To elucidate this, we planned to investigate the effect of IL-6 on a multi-bacterial infection, one of the most frequent post-injury complications. CDF1 male mice were administered recombinant human IL-6 (hIL-6) continuously at a dose of 0, 1, or 10 microg/day. The mice then underwent cecal ligation without puncture that induced slow multi-bacterial infection. The survival rate of mice receiving 10 microg/day of hIL-6 was significantly lower (38.5%) than the rate of those receiving 0 (83.3%) or 1 (92.3%) microg/day of hIL-6. The result of this study showed that only excessive increases in serum IL-6, to levels that were observed among patients who underwent severe injury or extensive surgery with high incidence of post-injury infection, jeopardize the host's defense against bacterial infection.

Animals↗