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Biomedical subjects

H Okabe

Publications and source records attributed to H Okabe.

At least 163 records · Page 9Linked to original sources

Antitumor activity of 1 M tegafur-0.4 M 5-chloro-2,4-dihydroxypyridine-1 M potassium oxonate (S-1) against human colon carcinoma orthotopically implanted into nude rats.

The purpose of this study was to establish a nude rat orthotopic (organ-specific) human colorectal cancer model as an in vivo secondary screen for general evaluation of new anticancer agents against colorectal cancer and to evaluate practically the antitumor activity of 1 M tegafur-0.4 M 5-chloro-2,4-dihydroxypyridine-1 M potassium oxonate (S-1), a new p.o. fluoropyrimidine, in comparison to 1 M tegafur-4 M uracil [(UFT) effective on colorectal tumor in clinical]. After implantation of KM12C, a human colorectal cancer cell line, into the subserosal layer of the colon as a single-cell suspension, extensive local tumor growth and invasion to both the mucosal and the serosal sides were observed in all rats. Metastatic foci were also formed in both lymph nodes and lungs following local tumor growth in all of them. Using this method, an equitoxic dose of S-1 (15 mg/kg/day) and UFT (30 mg/kg/day) was administered p.o. for 14 consecutive days from 7 days after tumor cell implantation. S-1 showed a higher tumor growth inhibition than UFT did [S-1, 57% (significantly different from the tumor weight of the untreated group at P < 0.05) and UFT, 18% (P > 0.05)]. When both drugs were administered to nude rats bearing KM12C injected into the cecal wall for 28 consecutive days at equitoxic doses, the mean survival in the S-1 group was 16 days longer than that in the untreated group (P < 0.01) but that in the UFT group was only 8 days longer (P > 0.05). After the administration of an equitoxic dose of both drugs, S-1 gave the higher levels than UFT in various pharmacokinetic parameters as follows: area under the curve 0-24 h of 5-fluorouracil in plasma (3.5-fold), area under the curve 0-24 h of 5-fluorouracil incorporated into RNA in the tumor (1.3-fold), and thymidylate synthase inhibition rate (percentage) in the tumor (about 20%). Collectively, these findings suggested that this orthotopic human colorectal tumor model in nude rats is useful to evaluate the clinical therapeutic efficacy of drugs or therapies for colorectal cancer, and that S-1 had a higher therapeutic effect on human colorectal tumor than UFT did.

Adenocarcinoma↗

Pulmonary vascular injury induced by hemorrhagic shock is mediated by P-selectin in rats.

To investigate whether the P-selectin-mediated leukocyte adhesion to the endothelial cells is involved in pulmonary vascular injury after hemorrhagic shock, we examined the effect of an anti-P-selectin monoclonal antibody (MAb PB1.3) on the pulmonary accumulation of leukocytes and the subsequent pulmonary vascular injury observed after hemorrhagic shock in rats. Two hours after hemorrhagic shock, pulmonary accumulation of leukocytes, as evaluated by measuring myeloperoxidase activity, began to increase and peaked after 6 hours. Pulmonary vascular injury, as evaluated by the extravascular leakage of 125I-albumin, was significantly increased 6 hours after hemorrhagic shock. MAb PB1.3 significantly prevented both the pulmonary accumulation of leukocytes and subsequent pulmonary vascular injury. MAb PNB1.6, an anti-P-selectin monoclonal antibody incapable of inhibiting P-selectin-mediated leukocyte adhesion, did not prevent either of these effects. These observations strongly suggest that the pulmonary sequestration of leukocytes and the subsequent pulmonary vascular injury after hemorrhagic shock are mediated by P-selectin.

Animals↗

Activated protein C attenuates endotoxin-induced pulmonary vascular injury by inhibiting activated leukocytes in rats.

We investigated the effect of activated protein C (APC) on lipopolysaccharide (LPS)-induced pulmonary vascular injury in rats to investigate the possible usefulness of APC as a treatment for adult respiratory distress syndrome. Intravenously administered LPS (5 mg/kg) significantly increased pulmonary vascular permeability. APC prevented the LPS-induced increase in pulmonary vascular permeability observed at 6 hours. Heparin plus antithrombin III (ATIII) and active site-blocked factor Xa (DEGR-Xa), a selective inhibitor of thrombin generation, inhibited LPS-induced coagulopathy but did not prevent LPS-induced pulmonary vascular injury. LPS-induced pulmonary vascular injury was significantly attenuated in rats with nitrogen mustard-induced leukocytopenia and in rats treated with ONO-5046, a potent granulocyte elastase inhibitor. Administration of LPS also increased pulmonary accumulation of leukocytes, as evaluated by measurement of myeloperoxidase activity in the lungs. APC significantly reduced LPS-induced increases in pulmonary accumulation of leukocytes at 1 hour. Neither ATIII plus heparin nor DEGR-Xa inhibited leukocyte accumulation. Active site-blocked APC (DIP-APC) prevented neither the LPS-induced pulmonary accumulation of leukocytes nor the LPS-induced increase in pulmonary vascular permeability. These results suggest that the mechanism of APC inhibition of LPS-induced pulmonary vascular injury was independent of its anticoagulant activity and was related to its ability to inhibit accumulation of leukocytes. In addition, these findings suggest that the serine protease activity of APC may be essential to its inhibitory effect on LPS-induced pulmonary accumulation of leukocytes and subsequent pulmonary vascular injury.

Amino Acid Chloromethyl Ketones↗

Determination of plasma soluble fibrin using a new ELISA method in patients with disseminated intravascular coagulation.

We measured plasma levels of soluble fibrin (SF) in 98 patients suspected of having disseminated intravascular coagulation (DIC) using a newly developed enzyme-linked immunosorbent assay (ELISA) and investigated the correlations between SF determinations and measurements of other hemostatic molecular markers to determine the diagnostic usefulness of determinations of SF. Patients were classified into four groups according to their clinical and laboratory findings: overt DIC (n =33), subclinical DIC (n =23) hypercoagulability (n =22), and non-DIC (n =20). SF levels were significantly higher in patients with overt DIC compared with the other three groups and were significantly higher in the subclinical DIC and hypercoagulability groups compared with the non-DIC patients. SF levels increased significantly with each increase in the clinical stage. Although levels of thrombin-antithrombin III complex (TAT), prothrombin fragment 1 + 2 (PF 1+2), cross-linked fibrin degradation products (XDP), and plasmin-antiplasmin complex (PAP) were significantly increased in patients with overt DIC compared with non-DIC patients, the values of these hemostatic molecular markers did not consistently show an increase in association with advances in the disease stage. Plasma levels of SF in patients with overt DIC showed a positive correlation with levels of TAT, XDP,and FDP(E), but not with PF1+2 and PAP. Analysis of receiver-operating characteristic curves showed that the sensitivity and specificity of SF were similar to those of XDP for diagnosis of DIC. The sensitivity and specificity of SF for diagnosis of overt DIC were both above 90% when the cut-off value was set at 65 mu g/ml.plasma levels of SF were also increased in patients with extravascular fibrin formation without DIC. Our findings suggest that measurement of plasma levels of SF by this ELISA method is useful for the diagnosis of DIC and the evaluation of the patient's clinical status.

Amino Acid Sequence↗

A novel automated assay for malate dehydrogenase isoenzymes.

We have developed a new automated method for the determination of malate dehydrogenase (MDH) isoenzymes in serum employing guanidine hydrochloride. Our proposed method showed good reproducibility; within-run precision coefficient of variations (CVs) were less than 2.5 (mean 13.6-42.9 U/L) for total MDH (T-MDH) and less than 6.7% (mean 6.3-23.5 U/L) for mitochondrial MDH (m-MDH) (n = 10). The upper detection limit of the proposed method exhibited good linearity up to 1,000 U/L for both T-MDH and m-MDH. In the proposed m-MDH reagent, the presence of up to 2,000 U/L of cytosolic MDH(c-MDH) activity had no effect on the outcome of m-MDH assay. Results of our proposed method (y) correlated well with those of the electrophoretic method (x) giving the regression equation: y = 1.46 x + 6.87 (N = 30); r = 0.99. Normal concentrations of various anticoagulants and bilirubin did not affect the assay results. Both ascorbic acid and glucose exhibited a slight positive interference with the proposed assay. Clinically, we found that m-MDH activity in serum had greater diagnostic predictive value than T-MDH activity for judging successful outcome of reperfusion therapy; the prognosis was poor when the m-MDH/T-MDH ratio was greater than 20%.

Adult↗

Macrophage inflammatory protein-1 alpha expression in non-neoplastic and neoplastic lung tissue.

The chemokines are members of a bipartite superfamily of soluble proteins that have been implicated in a wide range of acute and chronic inflammatory processes, as well as other immunoregulatory functions. Macrophage inflammatory protein-1 alpha (MIP-1alpha) belongs to the C-C subfamily of these chemokines and is primarily a potent chemoattractant and activator of monocytes. MIP-1alpha is also thought to play a role in host defence. We examined the expression of MIP-1-alpha in normal lung, inflammatory lung tissue and lung cancer cells by the immunoperoxidase method using a MIP-1alpha monoclonal antibody. MIP-1alpha protein was found to be expressed not only by alveolar macrophages, but also by bronchial ciliated cells, hyperplastic alveolar type II cells and activated fibroblasts surrounding malignant tissue. Of 33 cases of lung cancer, 23 (70%) expressed MIP-1alpha. These observations suggest that lung cancer cells, non-neoplastic alveolar type II cells and fibroblasts can participate in inflammatory cell recruitment via the production of MIP-1alpha. Tumour derived MIP-alpha may also affect the interaction between lung cancer and host inflammatory cells.

Aged↗

Effect of bucillamine on the rat trinitrobenzene sulfonic acid induced model of colitis.

Salicylazosulphapyridine and corticosteroids are the only remedies for inflammatory bowel disease currently in clinical use. They do not, however, necessarily bring about satisfactory therapeutic benefits, so that new agents are needed. In this study, we evaluated the effect of bucillamine, a new antirheumatic agent, in experimental rat colitis induced by trinitrobenzene sulfonic acid enema. Wistar rats were given vehicle alone (n = 16) or treated with 50 (n = 20) or 150 (n = 20) mg/kg of bucillamine daily for three weeks after induction of colitis. Conventional histological sections of the colon stained by haematoxylin and eosin were prepared and observed under a light microscope to determine colonic damage scores. The determinations were significantly lower in the group treated with 50 mg/kg of bucillamine and tended to be lower in the group treated with 150 mg/kg of bucillamine than in the untreated group, which implied that the experimentally induced colonic inflammatory changes and ulcerations were alleviated by bucillamine. Blood tests showed no abnormal values at the end of the treatment. The present observations suggest that bucillamine should be developed further as a possible therapy for inflammatory bowel disease.

Animals↗

Expression of an epithelial membrane glycoprotein by neurons arising from the human olfactory plate through development.

Human terminal-vomeronasal neural crest cells began to express a 34,000 molecular weight epithelial membrane glycoprotein, which was detected by the mouse monoclonal antibody Ber-EP4 soon after their migration into the olfactory plate. Expression of this antigen continued in neurons arising from these cells, which were olfactory sensory neurons and luteinizing hormone-releasing hormone-producing neurons migrating into the brains of the embryos of approximately 44-52 postovulatory days. Ber-EP4 immunoreactivity appeared over the entire surface membranes of these neurons, including their processes, not only in their extracerebral portions, but also within the brain parenchyma from 48 to 53 postovulatory days. Ber-EP4 immunoreactivity of these migrating neurons became weaker as they matured into luteinizing hormone-releasing hormone-producing neurons and disappeared from the postnatal hypothalamic neurons; however, it remained in the primary sensory nerve fibers throughout postnatal life. Except for the neurons arising from the olfactory plate, no other human neurons express this epithelial antigen during the course of development. The mechanism and significance of the expression of this antigen in mature sensory neurons remains unclear, but the intramucosal location and morphological kinship of these neurons to epithelial cells may be related to this phenomenon. The results of the present study indicate that neurons arising from the olfactory plate are distinct from other neurons by having a 34,000 molecular weight epithelial membrane glycoprotein that can be detected by the mouse monoclonal antibody, Ber-EP4, during the embryonic stage. This antigen disappears from the luteinizing hormone-releasing hormone-producing neurons concomitant with maturation, but is preserved in the olfactory primary sensory nerve throughout postnatal life.

Antibodies, Monoclonal↗

Cell kinetics in mandibular ameloblastic fibro-odontoma evaluated by bromodeoxyuridine and proliferating cell nuclear antigen immunohistochemistry: case report.

A case of ameloblastic fibro-odontoma in a 10-year-old Japanese male patient is presented. Bromodeoxyuridine (BrdU) and proliferating cell nuclear antigen (PCNA) immunohistochemistry were applied to investigate the cell kinetics of this lesion. The tumour proliferation activity was individually evaluated through the labelling index (LI) at the epithelial and mesenchymal components. The LI of BrdU was 0.9% in the epithelial and 2.1% in the mesenchymal component, while the LI of PCNA was 2.2% in the epithelial and 7.7% in the mesenchymal component. These immunohistochemical investigations suggest that the mesenchymal component was more proliferative than the epithelial component. Such an immunohistochemical investigation may be useful in evaluating the proliferative potential of odontogenic tumours.

Bromodeoxyuridine↗

Expression of bcl-2 oncogene product in primary non-Hodgkin's malignant lymphoma of the oral cavity.

The B-cell leukemia/lymphoma-2 (bcl-2) proto-oncogene is peculiar, as its product appears to provide survival advantage to B cells by blocking apoptosis. Expression of bcl-2 protein was analyzed in 54 cases of primary non-Hodgkin's malignant lymphomas of the oral cavity by immunohistologic staining of paraffin-embedded tissue. The immunophenotype of each tumor was established with the use of a panel of monoclonal and polyclonal antibodies to lymphoid cell differentiation antigens. The cases in the present study were 42 B-cell lymphomas, 7 T-cell lymphomas and 5-lymphomas revealing histiocytic markers. Sixteen of the 42 B-cell lymphomas were positive for bcl-2 protein, and were composed of 7 low-grade B-cell lymphomas and 9 high-grade B-cell lymphomas. Seven low-grade B-cell lymphomas were composed of one mucosa-associated lymphoid tissue type, three centrocytic types and three centroblastic-centrocytic types. Nine high-grade B-cell lymphomas comprised four centroblastic types, one immunoblastic type and four lymphoblastic types. Enhanced expression of the bcl-2 oncogenic protein was detectable in lymphoma cells in 2 cases for the T-cell lymphoma, and one case for the true histiocytic lymphoma. In contrast to the previous reports of American node-based lymphomas, Japanese primary oral lymphomas in our series expressed a lower frequency of bcl-2 protein. Furthermore, the present study indicated that bcl-2 protein was expressed on a wide variety of B-cell lymphomas, T-cell lymphomas and true histiocytic lymphoma, and that differences in bcl-2 protein expression may be useful in the diagnostic separation of lymphoblastic lymphoma with B-cell marker from Burkitt's lymphoma.

Adult↗

Precise determination of TSH receptor antibody activity in serum containing bovine TSH (bTSH) binding antibody by absorption using denatured bTSH or sheep FSH.

A previous report demonstrated that sera with bovine TSH (bTSH) binding antibody showed abnormally negative TSH receptor antibody (TRAb) activity in the standard TRAb assay method. The corrected TRAb activity calculated by the determination of the nonspecific binding of the labeled bTSH for each test serum [NSB(T)] resulted in positive TRAb activity. However, the precise calculation was difficult because NSB(T) level was significantly higher than the nonspecific binding in normal pool serum [NSB(N)] level. In the present experiment the determination of the TRAb activity was performed after absorption of bTSH binding antibodies by the heat-denatured bTSH to obtain more precise TRAb activity. In addition, absorption by sheep FSH (sFSH) was performed because almost all bTSH binding antibodies showed specific binding to the alpha-subunit of mammalian pituitary glycoprotein hormones in our previous study. Three days absorption of test serum using 1 mU of the heat-denatured bTSH (100 degrees C for 1 h) or 5 mU of sFSH was chosen as optimal because NSB(T) decreased remarkably to NSB(N) levels. The corrected TRAb determined after these absorptions decreased significantly compared to the corrected TRAb activity without the absorption. When the complete absorption of bTSH binding antibody was performed by the decrease of the NSB(T) level to the NSB(N) level, the TRAb activity determined by these two different absorptions was almost similar (difference was less than 10%). However, it was difficult to obtain the precise TRAb activity in the cases with extremely high bTSH binding antibody, because the NSB(T) level was higher than the NSB(N) level by the incomplete absorption of bTSH binding antibody.

Absorption↗

Use of preoperative autologous blood donations and erythropoietin for treatment of giant cell tumor of the ischium.

A 24-year-old man with an osteolytic lesion of the ischium was referred to the authors' institution. Computed tomography and magnetic resonance imaging studies showed that the lesion extended to and involved the subchondral bone of the acetabulum. Histologic examination of the biopsy specimen revealed giant cell tumor of bone. Following the biopsy, autologous blood was collected 4 times with recombinant human erythropoietin treatment definitive surgery was performed. Three weeks after the biopsy, the lesion was curetted and bone cementation was performed. The total blood loss during surgery was 3100 ml, which was replaced successfully with stored autologous blood without the need for homologous blood transfusion. The authors believe that without the erythropoietin treatment, autologous blood could have been collected only 3 times instead of 4 times, and the patient would have needed homologous blood.

Adult↗

Role of granulocyte elastase in the formation of hemorrhagic shock-induced gastric mucosal lesions in the rat.

OBJECTIVE: To investigate the mechanism by which activated leukocytes induce gastric mucosal lesions, we examined whether granulocyte elastase is involved in the formation of such lesions in a rat model of hemorrhagic shock. DESIGN: Prospective, randomized, controlled study. SETTING: Research laboratory at a university medical center. SUBJECTS: Male Wistar rats, weighing 220 to 280 g. INTERVENTIONS: Animals were subjected to hemorrhagic shock by phlebotomy. ONO-5046, a granulocyte elastase inhibitor (300 mg/kg ip), was administered 30 mins before or after phlebotomy. The effects of antithrombotic substances and tranexamic acid on hemorrhagic shock-induced gastric mucosal lesions also were examined. The effects of granulocyte elastase on the thrombomodulin activity and 35S-glycosaminoglycan content of endothelial cells were examined, using cultured human umbilical vein endothelial cells.

Animals↗

Gabexate mesilate, a synthetic protease inhibitor, attenuates endotoxin-induced pulmonary vascular injury by inhibiting tumor necrosis factor production by monocytes.

OBJECTIVE: In order to determine whether gabexate mesilate, a synthetic protease inhibitor with anticoagulant properties, is useful for the treatment of adult respiratory distress syndrome, we examined its effect on endotoxin-induced pulmonary vascular injury in rats. DESIGN: Prospective, randomized, controlled study. SETTING: Research laboratory at a university medical center. SUBJECTS: Male Wistar rats (180 to 220 g.) INTERVENTIONS: Animals received intravenous infusions of endotoxin (5 mg/kg iv) or saline (control). Pulmonary vascular injury was assessed 6 hrs after administration of endotoxin in terms of the increase in vascular permeability. Rats received gabexate mesilate (10 mg/kg ip), heparin, antithrombin III, an inactive derivative of activated factor X (a selective inhibitor of thrombin generation), or N-[2-[4-(2,2-dimethyl-propionyloxy) phenylsulfonylamino] benzoyl] aminoacetic acid (ONO-5046) (a potent granulocyte elastase inhibitor) 30 mins before endotoxin administration. Leukocytopenia was induced by administration of methotrexate. The effects of the gabexate mesilate on the function of activated neutrophils and the production of tumor necrosis factor -alpha (TNF-alpha) by endotoxin-stimulated monocytes were examined in vitro using neutrophils and monocytes prepared from healthy human volunteers. MEASUREMENTS AND MAIN RESULTS: Pulmonary vascular permeability was determined by measuring the vascular leakage of intravenously administered 125I-labeled bovine serum albumin. Intravenous administration of endotoxin significantly increased pulmonary vascular permeability. Gabexate mesilate significantly inhibited pulmonary vascular injury observed 6 hrs after the administration of endotoxin. Pulmonary vascular injury was not attenuated by the administration of heparin, heparin plus antithrombin III, or the inactive derivative of activated factor X, but pulmonary vascular injury was significantly attenuated in animals with methotrexate-induced leukocytopenia and in those animals treated with N-[2-[4-(2,2-dimethyl-propionyloxy) phenylsulfonylamino] benzoyl] aminoacetic acid. Gabexate mesilate in concentrations of 10(-4) to 10(-3) M inhibited the release of granulocyte elastase and leukocyte aggregation stimulated by N-formyl-methionyl-leucyl-phenylalanine and the opsonized zymosan-activated production of superoxide radical by neutrophils in vitro. Gabexate mesilate significantly inhibited the endotoxin-induced increase in the serum concentration of TNF-alpha in vivo and, at a concentration of 10(-8) M, the production of TNF-alpha by endotoxin-stimulated monocytes in vitro. CONCLUSION: Our findings suggest that gabexate mesilate attenuated endotoxin-induced pulmonary vascular injury mainly by inhibiting TNF-alpha production by monocytes, which may play a central role in sepsis-related lung injury.

Animals↗

Role of granulocyte elastase in ischemia/reperfusion injury of rat liver.

OBJECTIVE: To investigate the role of granulocyte elastase in ischemia/reperfusion injury of liver, the effect of ONO-5046, a granulocyte elastase inhibitor, was examined in ischemia/reperfusion-induced liver injury in rats. DESIGN: Prospective, randomized, controlled study. SETTING: Research laboratory at a university medical center. SUBJECTS: Male Wistar rats, weighing 220 to 280 g. INTERVENTIONS: Animals receiving continuous intravenous infusion of ONO-5046 (50 mg/kg/hr) were subjected to hepatic ischemia/reperfusion. Hepatic damage was evaluated by effects on bile formation capacity, plasma clearance of indocyanine green, and serum aminotransferase concentrations after ischemia/reperfusion. MEASUREMENTS AND MAIN RESULTS: Hepatic dysfunction, observed after 60 mins of ischemia/reperfusion, led to a reduction in bile flow and to a decrease in the plasma clearance of indocyanine green. These indicators of hepatic dysfunction were prevented, to a large extent, by administration of ONO-5046. Serum concentrations of aminotransferases increased after hepatic ischemia/reperfusion, peaking at 12 hrs of reperfusion. Increases in serum concentrations of aminotransferases were significantly inhibited by ONO-5046. CONCLUSION: Granulocyte elastase derived from activated leukocytes may play a critical role in hepatic dysfunction and the subsequent hepatic injury induced by ischemia/reperfusion.

Animals↗

Distribution and anti-inflammatory effect of mesalazine on carrageenan-induced colitis in the rabbit.

1. A controlled-release preparation of mesalazine microgranules (PentasaR; Ferring AS, Vanlose, Denmark) releases the active ingredient over a wide area from the small intestine to the rectum and is consequently expected to bring about therapeutic benefits to patients with ulcerative colitis and Crohn's disease. 2. Mesalazine microgranules (50 or 150 mg/kg per day) were administered orally to each rabbit with carrageenan-induced colitis for six weeks. Its inhibitory effect on colonic mucosal damage was assessed in terms of the microscopic damage scores, leukotriene B4 concentrations and concentrations of mesalazine derivatives. 3. At the end of the experiment, the mesalazine 150 mg group had gained a significantly greater bodyweight than the control group. Microscopic damage was significantly lower in the 150 mg group than in the untreated control group. Tissue concentrations of 5-aminosalicylic acid and acetyl-5-amino-salicylic acid in the small and large intestine were higher in the 150 mg group than in the 50 mg group. Mucosal leukotriene B4 levels tended to be lower in rabbits receiving the larger dose of mesalazine. 4. The present study indicates that slow release 5-amino-salicylic acid at the larger dose reaches the large bowel in sufficiently high concentrations following oral administration and significantly reduces carrageenan-induced colitis in the rabbit.

Aminosalicylic Acids↗