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Biomedical subjects

S Arii

Publications and source records attributed to S Arii.

At least 91 records · Page 5Linked to original sources

Pathogenic role of Kupffer cell activation in the reperfusion injury of cold-preserved liver.

The present study was designed to investigate the possible participation of Kupffer cells in the development of reperfusion injury of the cold-stored liver graft. In the cold preservation of Kupffer cells with Euro-Collins solution, the proportion of asialo-GM1-positive cells was significantly increased at 12 and 24 hr of storage, and the TNF alpha-producing activity in these cells was approximately fivefold greater than control. Northern blot analysis demonstrated that TNF alpha mRNA was remarkably elevated in the reperfusion of the cold-preserved liver, although that of the prereperfused graft was only slightly induced. The reperfusion experiments of the cold-stored liver graft showed that addition of anti-TNF alpha antibody to the perfusate suppressed the elevation of the effluent levels of GOT and LDH significantly, and that pretreatment with a Kupffer cell inhibitor, gadolinium chloride, inhibited the increase of these enzymes in the effluents almost completely. Histological study revealed deposition of a fibrinlike substance in the sinusoid and the central veins extensively in the reperfused liver graft, whereas no apparent deposition was observed in the gadolinium-pretreated liver. Thus, the present study showed that Kupffer cells were primed by cold preservation with Euro-Collins solution, and then activated when the reperfusion was done. It seems likely that the Kupffer cell activation induced by cold preservation/reperfusion plays a major role in reperfusion injury with sinusoidal microcirculatory disturbance, and that TNF alpha is responsible for the impairment of the reperfused liver graft.

Alanine Transaminase↗

Typical fibrolamellar hepatocellular carcinoma in Japanese patients: report of two cases.

We report herein the cases of two Japanese patients with typical fibrolamellar hepatocellular carcinoma treated at our institute. The first patient was a 19-year-old man with no hepatitis B or C viral infection and a normal, noncirrhotic liver in the nontumorous area. The second was a 36-year-old woman with no viral infection and a noncirrhotic liver in the nontumorous area. The clinicopathology, imaging appearances, and histology of both cases were similar to reports from the United States.

Adult↗

Chemical mediator release and surface marker expression of hepatic macrophages in rats with CCl4-induced liver cirrhosis.

The present study was performed to analyze possible functional alterations of hepatic macrophages (HM phi) in rats with carbon tetrachloride (CCl4)-induced liver cirrhosis. HM phi from rats injected with CCl4 for 13 weeks and cultured for 24 hours released less than normal amounts of prostaglandin E2 (PGE2) and tumor necrosis factor (TNF) and very large amounts of interleukin-1 (IL-1). In rats injected with CCl4 for 9 weeks, only PGE2 production was reduced. Interleukin-2 receptor (IL-2R), Ia antigen and asialo GM1 antigen expressions on HM phi from both the 9- and 13-week groups were significantly decreased. IL-2R and Ia antigen expressions showed larger decreases in the 13-week group. Thus, it is concluded that HM phi derived from CCl4-induced cirrhotic livers show a functional alteration in the release of cytokines (except for IL-1) and a decrease in surface marker expression, as cirrhosis advances. These results should provide a basis for further investigation into the host-compromised status in the presence of liver cirrhosis.

Animals↗

Identification of the thromboxane A2 receptor in hepatic sinusoidal endothelial cells and its role in endotoxin-induced liver injury in rats.

The presence of the thromboxane A2 receptor in sinusoidal endothelial cells was investigated and its pathogenic role in endotoxin-induced liver injury examined. The receptor was measured with a binding assay using a specific thromboxane A2 receptor antagonist, [3H]S-145. Scatchard analysis of the binding indicated the presence of a single class of high-affinity binding sites with a dissociation constant of 5.00 +/- 0.96 nmol/L, a maximal binding of 22.85 +/- 2.71 fmol/10(6) cells and 13.80 +/- 1.60 x 10(3) binding sites per cell. The addition of a cyclooxygenase inhibitor, indomethacin, during the cell preparation increased the maximal binding value and the number of binding sites of 37.34 +/- 3.01 and 22.50 +/- 1.80 x 10(3) sites/cell, respectively. The binding was displaced by various thromboxane A2 analogs such as ONO-3708 and STA2 but was not effectively competed for by other prostaglandins. Endotoxin injection reduced dissociation constant, maximal binding and the number of binding sites in sinusoidal endothelial cells to 3.49 +/- 0.87 nmol/L, 6.03 +/- 0.64 fmol/10(6) cells and 3.65 +/- 0.39 x 10(3) sites/cell, respectively. A cyclooxygenase inhibitor and a Kupffer cell inhibitor added before endotoxin treatment significantly prevented the reduction in the number of thromboxane A2 receptors. It is possible that these effects were due to a reduction in the agonist-induced internalization of the thromboxane A2 receptor brought about by the prevention of thromboxane A2 production. Preadministration of both a cyclooxygenase inhibitor and a thromboxane A2 receptor antagonist attenuated the degree of endotoxin-induced liver injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Immunologic activation of hepatic macrophages in septic rats: a possible mechanism of sepsis-associated liver injury.

To investigate the pathogenesis of liver dysfunction accompanying intra-abdominal sepsis, we used rats with cecal ligation and punctures (CLP) and examined the expression of the inflammatory cytokines IL-1-alpha, IL-1-beta, and TNF-alpha, as well as the expression of a cell adhesion molecule, ICAM-1, in the liver. We also examined the expression of Ia antigen and interleukin-2 receptor (IL-2R) on hepatic macrophages. Hepatic macrophages isolated from rats 24 hours after CLP exhibited significantly higher IL-1 and TNF activity than those from control rats. Hepatic macrophages isolated from rats 72 hours after CLP exhibited the maximal IL-1 and TNF activity. In the hepatic nonparenchymal cells, IL-1-alpha mRNA was induced 1 hour after CLP, increasing to the maximal level 3 hours after CLP, whereas IL-1-beta mRNA was induced gradually, reaching a peak 6 hours after CLP. ICAM-1 mRNA reached a peak 3 hours after CLP. Induction of TNF-alpha mRNA was not detected by the present Northern blot analysis. Seventy-two hours after CLP, the proportions of hepatic macrophages expressing Ia antigens and IL-2R were increased significantly, as revealed by the flow cytometric analysis. In conclusion, the present study showed that hepatic macrophages are in an activated state in sepsis as indicated by their increased production of inflammatory monokines and their increased expression of immunomodulatory surface molecules. Further, we demonstrated the sequential induction of the mRNA of the various inflammatory cytokines and ICAM-1. These findings strengthen the notion that these cytokines are relevant to the pathogenesis of liver injury associated with sepsis.

Animals↗

Chemical mediators released from hepatic macrophages in primary culture--basic characteristics of human hepatic macrophages and changes in liver cirrhosis.

Chemical mediators released from human hepatic macrophages (HHM phi) in primary cultures were analyzed for their secretory function and probable contribution to the modulation of the host defense system and metabolism in liver cirrhosis. In our basic studies, HHM phi increased dose dependently the release of superoxide (O2-) and interleukin-1 (IL-1) when stimulated by opsonized zymosan, up to 1000 micrograms/dish. PGE2 production showed a relatively narrow range of dose dependency, and larger doses led to a reduction of PGE2 yield in some samples. Next, we compared the mediator release from the HHM phi of patients with liver cirrhosis with that from HHM phi in normal liver. O2- released from HHM phi of 8 patients with liver cirrhosis was significantly decreased (controls, n = 20) (P < 0.01). IL-1 released from the HHM phi of 6 cirrhotic patients tended to be higher than that from the HHM phi of 10 control patients, but the difference was not statistically significant (P < 0.10). PGE2 production, however, was about the same in the two groups. These results suggest that cultured HHM phi have certain basic characteristics in releasing mediators with highly potent specific activities and also that these secretory abilities may change in liver cirrhosis. In conclusion, the analysis of cultured HHM phi may be a very practical way to clarify their inherent abilities and participation in the complicated clinical features of liver cirrhosis.

Carcinoma, Hepatocellular↗

The role of Kupffer cells in the surveillance of tumor growth in the liver.

The present study was designed to investigate the role of Kupffer cells (Kc) in the surveillance of liver tumors. We examined the antitumor activity of Kc by 51Cr releasing assay and inhibition of [3H]thymidine ([3H]TdR) incorporation into tumor cells. We also studied the change in the growth of liver tumors following the activation and the blockade of Kc. The cytotoxicity of Kc against K562 increased as the effector:target (E:T) ratio rose and reached its maximum level of about 18% at an E:T ratio of 20:1. [3H]TdR incorporation into target cells (P815 and AH130) was also inhibited by Kc. Such antitumor activity of Kc was augmented by OK432 (K562, from 13.8 +/- 5.6 to 21.9 +/- 2.5%; AH130, from 19.2 +/- 14.5 to 37.1 +/- 12.6%). In the experiment of the inoculation of AH130 via the portal vein, OK432 decreased the number of hepatic foci, whereas macrophage inhibitors carrageenan and gadolinium increased the number of tumor nodules. In addition, gadolinium injection reduced the number of Kupffer cells reactive with monoclonal antibodies directed against macrophages ED2 and Ki-M2R. Tumor growth in the liver was maximum in rats with both gadolinium treatment and splenectomy. In conclusion, Kc have antitumor activity, and augmentation of Kc may be a possible strategy to prevent hematogenous hepatic metastasis.

Animals↗

Prostaglandin E2 production by hepatic macrophages and peripheral monocytes in liver cirrhosis patients.

We analyzed PGE2 production in primary-cultured human hepatic macrophages (HHM phi) and peripheral monocytes (MO) from patients with and without liver cirrhosis, and correlated PGE2 production with the patients' liver function. Serum choline esterase (ChE) levels were used as an indicator of liver function. PGE2 production in both HHM phi and MO from cirrhotic patients was significantly lower than in HHM phi and MO from non-cirrhotic patients. PGE2 production in cirrhotic HHM phi was inversely correlated with ChE levels, whereas PGE2 production in cirrhotic MO showed no obvious correlation. In conclusion, both HHM phi and MO might contribute to the pathophysiology of liver cirrhosis via attenuated PGE2 production. Furthermore, HHM phi activity appears to be more strongly affected by the chronic pathological changes observed in the cirrhotic liver.

Cells, Cultured↗

Superoxide release by primary-cultured human hepatic macrophages and peripheral monocytes from patients with normal and cirrhotic livers.

We analysed superoxide anion (O2-) release from primary-cultured human hepatic macrophages (HHM phi) and peripheral blood monocytes (MO) derived from patients with normal and cirrhotic livers. Primary cultured human hepatic macrophages and MO from cirrhotic patients released less O2- than cells from normal patients. Superoxide anion release by HHM phi showed a significant, positive correlation with the serum glutamate pyruvate transaminase (GPT) level, whereas O2- release by MO showed only a weak correlation with the GPT level. In conclusion, a significant reduction in O2- release was observed in HHM phi and MO cultured from cirrhotic patients. Primary-cultured human hepatic macrophages are probably more susceptible to environmental changes within the cirrhotic liver than MO, since they are found locally within the liver and correlate with serum GPT levels.

Aged↗

Predictive factors for intrahepatic recurrence of hepatocellular carcinoma after partial hepatectomy.

To establish useful predictors of the intrahepatic recurrence of hepatocellular carcinoma (HCC) after partial hepatectomy, retrospective analyses of clinical and pathologic factors were done in 112 of 206 patients treated by partial hepatectomy. The absence or presence of intrahepatic recurrence was confirmed by a follow-up study. Cancer-free survival rates after 1, 2, 3, and 5 years were 54.8%, 36.7%, 32.5%, and 25.6%, respectively. The significant factors affecting recurrence were tumor size, number of tumors, cancer cell infiltration of the fibrous capsule of the tumor, portal involvement, and stage of the tumor, but the grade of anaplasia according to Edmondson-Steiner's classification and the severity of associated liver cirrhosis did not show a correlation with the incidence of recurrence. According to Akaike's Information Criteria (AIC), tumor number is useful for predicting early prognosis, and capsular infiltration is a good indicator of long-term survival. However, portal involvement gives much prognostic information throughout the entire postoperative period.

Adult↗

Enhancement of rat hepatic macrophages by treatment with interleukin-2 and streptococcal preparation OK432, with reference to antitumor activity, soluble factor production and Ia expression.

The effect of biological response modifiers, such as interleukin-2 (IL-2) and streptococcal preparation OK432, on the functions of hepatic macrophages was investigated. The macrophages, even with no exogenous stimulation, produced superoxide anion (O2-) and tumor necrosis factor (TNF), displayed cytotoxicity against K562 cells and cytostasis against P815 cells and expressed immune-region-associated antigen (Ia). IL-2 administered in vitro or in vivo enhanced O2- production by hepatic macrophages and the intravenous injection of OK432 also enhanced O2 production. Furthermore, IL-2 added to the culture medium of hepatic macrophages isolated from OK432-injected rats augmented O2- production even more. The TNF production and Ia expression of the macrophages were also increased by the intravenous injection of OK432. As with O2- production, the cytotoxicity of the cells was enhanced by OK432 injection or by IL-2 added to the culture medium and the combination of OK432 and IL-2 augmented their cytotoxicity even more. Thus, the present study suggested that IL-2 and OK432 induce the augmentation of the antitumor activity of hepatic macrophages, partly as a result of the increase in production of O2- and TNF and Ia expression.

Animals↗

Effect of anticancer agents on cell cycle of regenerating hepatocytes in rats.

The effect of three anticancer agents, cisplatin, doxorubicin, and mitomycin, on liver regeneration after 70% partial hepatectomy in rats was investigated by total DNA content of the liver and flow cytometric analysis of hepatocyte nuclei using two-color staining of anti-bromodeoxyuridine monoclonal antibody and propidium iodide. Total DNA content of regenerating liver 7 days after hepatectomy showed significant suppression of regeneration by these agents (P less than 0.01). The inhibitory effects of the agents on the cell cycle of hepatocytes by flow cytometric analysis were (1) a delay of the peak or a decrease in the proportion of S phase nuclei and/or (2) polyploidization of the nuclei, demonstrated by accumulation of 8c and occasionally 16c nuclei, of which the DNA contents were four and eight times as much as that of diploid (2c) cell nuclei, respectively. The former (1) suggests G0 or G1 phase block, and the latter (2) G2 phase block. In terms of total DNA content of regenerating liver, the inhibitory effect was most prominent in the cisplatin-administered groups. The polyploidization of nuclei was most remarkable in the mitomycin-administered groups. Although the total DNA content recovered to the level of control at 6 weeks after hepatectomy, the polyploidization effect persisted in the drug-administered groups. These agents had no cytocidal action on proliferating hepatocytes as can be seen from the aspartate aminotransferase and alanine aminotransferase serum levels. We conclude that in a short-term observation, the anti-cancer agents significantly inhibit liver regeneration, although the inhibitory effect on DNA synthesis does not last long.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Tumoricidal activity of Kupffer cells augmented by anticancer drugs.

The effect of Mitomycin-C (MMC) and Adriamycin (ADM) on the antitumor-associated function of Kupffer cells was examined. MMC and ADM enhanced the production of superoxide by Kupffer cells in cultures at low concentrations likely to occur in clinical use. The expression of interleukin-2 receptor, Ia antigen and asialoGM1 antigen, measured by flowcytometry, was increased by contact with MMC. Growth inhibition of AH130, rat ascites hepatoma, and P815, murine mastocytoma, by Kupffer cells treated with anticancer drugs was greater than that by Kupffer cells alone or anticancer agent alone. These results show that MMC and ADM activate Kupffer cells, leading to synergistic antitumor activity. The results suggest that some anticancer agents act through immunological mechanisms as well as through direct antineoplastic activity.

Animals↗

Effect of PGE2 on interleukin-1 and superoxide release from primary-cultured human hepatic macrophages.

In order to learn more about how human hepatic macrophages function, we analyzed the effect of exogenous PGE2 on the amounts of interleukin-1 (IL-1) and superoxide (O2-) released from primary-cultured human hepatic macrophages (HHM phi). When endogenous PGE2 production was blocked by indomethacin, exogenous PGE2 reduced IL-1 release from HHM phi in a dose-dependent manner, whereas it tended to increase O2- release from HHM phi. These results may suggest the probable contribution of PGE2 in regulating HHM phi mediator release in vivo.

Cells, Cultured↗

Hepatic macrophage malfunction in rats with obstructive jaundice and its biological significance.

The present study was designed to investigate the pathophysiology of obstructive jaundice by analyzing the function of hepatic macrophages and their role in immune responses and homeostasis in rats. The phagocytic index, determined by the rate of disappearance of 51Cr-endotoxin from the peripheral blood after intravenous injection, was increased in obstructive jaundice 2 weeks after bile duct ligation. The superoxide production of isolated hepatic macrophages and peripheral blood monocytes, measured by the superoxide dismutase inhibitable ferricytochrome c reduction method, was increased. Prostaglandin E2 release, measured by RIA, was markedly increased in rats with obstructive jaundice, but there was no significant difference in interleukin-1 release between jaundiced and control rats. The flow-cytometric analysis of surface molecules of hepatic macrophages showed decreased expression of interleukin-2 receptor in rats with obstructive jaundice. Thus, the functions of hepatic macrophages in rats with obstructive jaundice were impaired. This malfunction may disturb the immunoregulatory network and metabolism, although the exact implications of the altered function of hepatic macrophages have not yet been clarified.

Animals↗

Cell kinetics of regenerating liver after 70% hepatectomy in rats--2-color flow cytometric analysis.

Two-color flow cytometric (FCM) analysis using anti-bromodeoxyuridine (BrdU) monoclonal antibody (MoAb) was used to investigate the cell kinetics of regenerating liver after 70% partial hepatectomy in rats. Three peaks were seen in DNA histograms of rat hepatocyte nuclei, corresponding to diploid(2c), tetraploid(4c), and octaploid(8c). These proportions changed in the course of regeneration which were clearly demonstrated by DNA histograms using flow cytometry. The proportion of diploid, tetraploid, and octaploid nuclei in control liver were 49.3 +/- 1.6%, 45.0 +/- 7.4%, and 1.7 +/- 0.7%, respectively. A significant change occurred at 24 hours after hepatectomy, as FCM revealed 25.9 +/- 1.1% diploid, 54.5 +/- 1.2% tetraploid, and 9.0 +/- 0.9% octaploid. This shift to polyploid nuclei persisted until 72 hours, and then gradually returned to the pattern of control liver. The S-phase nuclei which incorporated BrdU increased rapidly at 24 hours to a peak of 11.3 +/- 0.9%, and gradually decreased to 5.8 +/- 0.8%, 5.3 +/- 0.8%, 2.4 +/- 0.6%, 2.9 +/- 1.1%, and 1.2 +/- 0.6%, at 48, 72, 96, 120, and 168 hours, respectively. This 2-color FCM analysis made a detailed analysis of the cell kinetics in regenerating hepatocytes possible, and may be applied in investigations of various aspects of liver regeneration.

Animals↗

Tissue distribution of 2-3 and 2-6 sialyl Lewis A antigens and significance of the ratio of two antigens for the differential diagnosis of malignant and benign disorders of the digestive tract.

The authors investigated the tissue distribution of two kinds of sialylated derivatives of Lewis A (Le(a)) antigen in patients with cancers of the digestive system using specific monoclonal antibodies, and evaluated the significance of determining the 2-3 and 2-6 sialylated Le(a) antigen levels for the diagnosis of cancer. In most specimens from patients with cancers of the pancreas, biliary tract, stomach, and colon, the 2-3 sialylated Le(a) antigen was strongly expressed in cancer cells. However, 2-6 sialylated Le(a) antigen was less frequently expressed in cancer cells. The former is therefore more specific to cancer than the latter. Also, the serum level of the 2-3 sialylated Le(a) antigen was significantly higher than that of the 2-6 counterpart in patients with cancers of pancreas, biliary tract, stomach, and colon. The resulting ratio of serum 2-3/2-6 sialylated Le(a) antigens was frequently high in patients with malignancy and was low in patients with benign disorders of these digestive organs. Therefore, the 2-3/2-6 sialylated Le(a) antigen ratio is a useful for the differential diagnosis of malignant disorders in these organs. However, liver disorders were found to be exceptional in that both antigens were mostly absent in hepatocellular carcinoma (HCC) cells in immunohistologic examination, as well as in nonmalignant parenchymal liver cells. Only the epithelial cells of the intrahepatic bile ducts expressed the 2-6 sialylated Le(a) antigen strongly, and expressed the 2-3 sialylated Le(a) antigen moderately. The levels of both antigens were sometimes high in patients with liver disorders, but the ratio always remained low in patients with HCC as well as benign liver disorders such as cirrhosis or chronic hepatitis. The sialylated Le(a) antigens, which sometimes accumulate in the sera of patients with HCC, were concluded to originate from the epithelial cells of the proliferating small bile ducts, and those serum antigens cannot be considered as evidence for the presence of liver cancer cells.

Antibodies, Monoclonal↗