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Biomedical subjects

K Okajima

Publications and source records attributed to K Okajima.

At least 37 records · Page 2Linked to original sources

Recombinant tissue factor pathway inhibitor prevents lipopolysaccharide-induced systemic hypotension in rats by inhibiting excessive production of nitric oxide.

Excessive production of nitric oxide (NO) by the inducible form of NO synthase (iNOS) plays a key role in the development of endotoxin shock. Tumor necrosis factor-alpha (TNF-alpha) induces iNOS, thereby contributing to the development of shock. We recently reported that recombinant tissue factor pathway inhibitor (r-TFPI), an important inhibitor of the extrinsic pathway of the coagulation system, inhibits TNF-alpha production by monocytes. In this study, we investigated whether r-TFPI could ameliorate hypotension by inhibiting excessive production of NO in rats given lipopolysaccharide (LPS). Pretreatment of animals with r-TFPI prevented LPS-induced hypotension. Recombinant TFPI significantly inhibited the increases in both the plasma levels of NO2-/NO3- and lung iNOS activity 3 h after LPS administration. Expression of iNOS mRNA in the lung was also inhibited by intravenous administration of r-TFPI. However, neither DX-9065a, a selective inhibitor of factor Xa, nor an inactive derivative of factor VIIa (DEGR-F.Vlla) that selectively inhibits factor VIIa activity, had any effect on LPS-induced hypotension despite their potent anticoagulant effects. Moreover, neither the plasma levels of NO2-/NO3- nor lung iNOS activity were affected by administration of DX-9065a and DEGR-F.VIIa. These results suggested that r-TFPI ameliorates LPS-induced hypotension by reducing excessive production of NO in rats given LPS and this effect was not attributable to its anticoagulant effects, but to the inhibition of TNF-alpha production.

Animals↗

[Delayed paraparesis after osteoporotic vertebral fracture--with special reference between mechanism of symptoms, fracture level, age and operative methods].

We examined the operated 53 cases with delayed paraparesis after osteoporotic vertebral fracture. The causes of the symptoms were complicated and the analysis indicated that the anterior approach should be the first choice, however the posterior approach could be indicated for the following cases ; the main causes are posterior elements, multiple involvement, at middle and lower lumbar level, with severe osteoporosis, with systemic complication, over 80 years old. For high aged and osteoporotic patients, careful analysis of factors causing symptoms and less invasive operation as possible are needed.

English Abstract↗

Activated protein C reduces ischemia/reperfusion-induced renal injury in rats by inhibiting leukocyte activation.

We examined whether activated protein C (APC) reduces ischemia/reperfusion (I/R)-induced renal injury by inhibiting leukocyte activation. In a rat model, intravenous administration of APC markedly reduced I/R-induced renal dysfunction and histological changes, whereas intravenous administration of dansyl glutamylglycylarginyl chloromethyl ketone-treated factor Xa (DEGR-FXa; active-site-blocked factor Xa), heparin or diisopropyl fluorophosphate-treated APC (DIP-APC; inactive derivative of ARC) had no effect. Furthermore, APC significantly inhibited the I/R-induced decrease in renal tissue blood flow and the increase in the vascular permeability, whereas neither DEGR-FXa, heparin, nor DIP-APC produced such effects. Renal I/R-induced increases in plasma levels of fibrin degradation products were significantly inhibited by APC, DEGR-FXa, and heparin. These observations suggest that APC reduces I/R-induced renal injury independently of its anticoagulant effects but in a manner dependent on its serine protease activity. Renal levels of tumor necrosis factor-alpha (TNF-alpha), rat interleukin-8, and myeloperoxidase were significantly increased after renal I/R. These increases were significantly inhibited by APC but not by DEGR-FXa, heparin, or DIP-APC. Leukocytopenia produced effects similar to those of APC. These findings strongly suggest that APC protects against I/R-induced renal injury not by inhibiting coagulation abnormalities but by inhibiting activation of leukocytes that play an important role in I/R-induced renal injury. Inhibition of leukocyte activation by APC could be explained by the inhibitory activity of TNF-alpha. (Blood. 2000;95:3781-3787)

Amino Acid Chloromethyl Ketones↗

Simple and simultaneous analysis of fenfluramine, amphetamine and methamphetamine in whole blood by gas chromatography-mass spectrometry after headspace-solid phase microextraction and derivatization.

A simple and sensitive method for the simultaneous analysis of fenfluramine, amphetamine and methamphetamine in whole blood was developed using a headspace-solid phase microextraction (SPME) and derivatization. A 0.5 g whole blood sample, 5 microl d(5)-methamphetamine (50 micrig/ml) as an internal standard, and 0.5 ml sodium hydroxide (1 M) were placed into a 12 ml vial, and sealed rapidly with a silicone septum and an aluminum cap. Immediately after the vial was heated to 70 degrees C in an aluminium block heater, the needle of the SPME device was inserted through the septum of the vial, and the extraction fiber was exposed in the headspace for 15 min. First, heptafluorobutyric anhydride was injected into the injection port of the GC-MS, and the compounds extracted by the fiber were then desorbed and derivatized simultaneously by exposing the fiber in the injection port. The calibration curves, using an internal standard method, demonstrated good linearity throughout the concentration range from 0.01 to 1.0 microg/g. The detection limits of this method were 5.0 ng/g for fenfluramine and methamphetamine, and 10 ng/g for amphetamine. No interferences were found, and the time for analysis was about 30 min for one sample. This method was applied to a suicide case in which the victim ingested fenfluramine. Fenfluramine was detected in the blood sample collected from the victim at the concentration of 7.7 microg/g.

Adult↗

Heterogeneity in the incidence and clinical manifestations of disseminated intravascular coagulation: a study of 204 cases.

The incidence and clinical manifestations of disseminated intravascular coagulation (DIC) were examined in patients with a range of underlying disorders. Out of 1,882 patients suspected as having DIC, 204 cases were diagnosed as suffering from DIC and included in this study. The underlying disorders experienced by the patients were solid tumors (33.8%), hematologic malignancies (12.7%), aortic aneurysm (10.8%), infections (6.4%), post-operative complications (4.4%), liver disease (2.9%), obstetric disorders (2.5%), and miscellaneous diseases (26.5%). The incidence of DIC was 10.8% out of all patients suspected of having DIC, and the etiologies were 10.9% in solid tumors, 10.1% in hematological malignancies, 20.4% in aortic aneurysm, 12.7% in infections, 15.5% in post-operative complications, 15.8% in liver disease, 3.7% in obstetric disorders, and 9.8% in miscellaneous diseases. The clinical manifestations of DIC patients were varying dependent on their etiologies. Most DIC patients with aortic aneurysm (95.5%) and post-operative complications (88.9%) did not reveal any clinical manifestations. Although all of the patients with obstetric disorders had bleeding, only 20.0% of the patients had organ failure. In contrast, although only 15.4% of the patients with infections had bleeding, 76.9% of these patients had organ failure. Bleeding was observed in 31.9-50.0% of DIC patients with liver disease, hematologic malignancies, and solid tumors. Organ failure was observed in 21.7-33.3% of DIC patients with liver disease, hematological malignancies, and solid tumors. Analysis by measurement of plasma levels of antiplasmin and plasmin-antiplasmin complex suggested that excessive fibrinolysis might contribute to the development of bleeding in these DIC patients. Differences in plasma levels of thrombin-antithrombin complex and cross-linked fibrin degradation products could not account for the differences in the incidence of organ failure in the patients. These findings suggest that the clinical manifestation of DIC varies and might not only be a reflection of microthrombus formation but also a reflection of the other underlying pathomechanisms.

Antifibrinolytic Agents↗

Identification of a larger than 3 Mb deletion including JAG1 in an Alagille syndrome patient with a translocation t(3;20)(q13.3;p12.2).

Alagille syndrome (AGS) is an autosomal dominant, developmental disorder affecting multiple organ systems including liver, heart, vertebrae, eye and face. Recurrent deletions of the 20p12 region led to the localization, and ultimately to the identification of mutations in the Jagged1 gene (JAG1) in AGS patients. A translocation t(3;20)(q13.3;p12.2) in an AGS patient was characterized using fluorescent in situ hybridization (FISH). The involvement of 3q and 20p in this translocation was demonstrated using probes for 3q and 20p. Three overlapping YAC clones, 940D11, 953A2, and 675G11 extending to nearly 4 Mb including the JAG1 were used as probes for FISH analysis to define the translocation breakpoint. The translocated chromosome was found to have a deletion of more than 3 Mb including the entire JAG1 gene. The observation of an accompanying large deletion, revealed by molecular characterization of the t(3;20) translocation, is similar to the only other translocation reported in an AGS patient; a t(2;20) translocation was also found to have a large deletion of the JAG1 region at 20p12.

Alagille Syndrome↗

Reproducibility of geometric distortion in magnetic resonance imaging based on phantom studies.

BACKGROUND AND PURPOSE: Image distortion is one of the major drawbacks of magnetic resonance (MR) imaging for use in radiotherapy treatment planning (RTTP). In this study, the reproducibility of MR imaging distortion was evaluated by repeated phantom measurements. MATERIALS AND METHODS: A grid-pattern acrylic phantom was scanned with a 0.2-Tesla permanent magnetic unit. We repeated a series of scans three times to evaluate the reproducibility of the distortion. In each series, co-ordinates at 432 intersections of the grid were measured for both T1- and T2-weighted spin-echo (SE) pulse sequences. Positional displacements and their variations at the intersections were calculated. RESULTS: Averages of the displacements were distributed between 1.58 and 1.74 mm, and maximum values (MAX) between 12.6 and 15.0 mm. Within 120 mm of the image center, the average values ranged from 0.73 to 0.80 mm, and from 3.4 to 5.0 mm for MAX. The absolute values of the positional variations among three series were distributed between 0.41 and 0.88 mm for average values, and between 1.4 and 4.5 mm for MAX. CONCLUSIONS: The positional variations were mostly within 3 pixels, and most of the positional displacements within the radius of 120 mm of the image center were 2 mm or less. Therefore, it will be possible to use this MR system in RTTP under limited situations, although careful applications are required for RTTP of the body. The development of a computer program to correct image distortion is expected.

Artifacts↗

Neoadjuvant chemotherapy by transcatheter arterial infusion method for uterine cervical cancer.

PURPOSE: The effects of transcatheter intraarterial infusion of anticancer drugs on the prognosis of cervical cancer were retrospectively studied. MATERIALS AND METHODS: Two or three sessions of transcatheter arterial infusion therapy were performed in 97 patients with primary uterine cervical cancer. The number of patients in stage I, II, III, or IV were 15, 37, 34, and 11, respectively. The drugs infused were cisplatin (60-70 mg/m2), doxorubicin hydrochloride (30-40 mg/m2), mitomycin (15 mg/m2), and 5-fluorouracil (500 mg/body). They were infused via the bilateral internal iliac arteries. Seventy-five patients of the 97 (78%) underwent radical hysterectomy after arterial infusion: stage I (14 of 15), stage II (31 of 37), stage III (25 of 34), and stage IV (5 of 11). Three stage II and nine stage III patients received radical radiation therapy. The other 10 patients (one with stage I, three with stage II, and six with stage IV) did not receive an operation and radiation therapy after arterial infusion because of their distant metastases at the time of operation. Thirty-eight patients of 75 (51%) received postoperative radiation therapy. RESULTS: The complete histologic response rates (no active cancer cells) after arterial infusion were four of 14, four of 31, six of 25, and one of five for stages I, II, III, and IV. The histologic response rates, which showed no parametrial invasion after arterial infusion, were 12 of 14, 24 of 31, and 15 of 25 for stages I, II, and III. The histologic response rates, which demonstrated no lymph node metastases after arterial infusion, were 12 of 14, 24 of 31, and 19 of 25 for stages I, II, and III. The overall 5-year survival rates of the patients with stages I, II, and III were 93.3%, 58.7%, and 69.7%, respectively. The 5-year survival rates of the operated patients with stages I, II, and III were 100%, 60.5%, and 63.6%, respectively. The 5-year survival rates of the irradiated patients with stage III was 87.5%. Leukocytopenia and thrombocytopenia occurred as an acute complication in 75% and 79% of the patients, respectively. As a late complication, ileus occurred in 7%. CONCLUSION: Arterial infusion may improve the prognosis of patients with cervical cancer without increasing the incidence of late complications.

Adenocarcinoma↗

Activated neutrophils impair gastric cytoprotection role of neutrophil elastase.

Neutrophil elastase decreases production of PGI2 by cultured endothelial cells. Thus, neutrophil elastase may play an important role in gastric mucosal injury by decreasing the tissue level of PGI2, an important gastric cytoprotective substance. We examined whether activated neutrophils inhibit gastric PGI2 production in rats subjected to water-immersion restraint stress. Gastric 6-keto-PGF1alpha levels were determined by enzyme immunoassay. Gastric mucosal blood flow was determined by laser-Doppler flowmeter. Gastric microvascular permeability was determined by Evans blue leakage. Gastric levels of 6-keto-PGF1alpha were transiently increased 0.5 hr after the stress, followed by a decrease to below baseline at 6 hr, when mucosal blood flow fell to 60% of baseline. Gastric levels of 6-keto-PGF1alpha were significantly higher in animals with nitrogen mustard-induced leukocytopenia than in controls 1 and 6 hr after the stress. In leukocytopenic animals, levels 6 hr after stress were not lower than those preceding stress. Leukocytopenia markedly limited both the decrease in mucosal blood flow and the increase in gastric microvascular permeability. The level of gastric mucosal injury observed 6 hr after the stress was markedly attenuated by leukocytopenia. Pretreatment with neutrophil elastase inhibitors (ONO-5046 and Eglin C) or an anti-P-selectin monoclonal antibody produced effects similar to leukocytopenia. Neutrophil elastase is involved in the stress-induced gastric mucosal injury by decreasing gastric production of PGI2. Thus, pharmacologic inhibition of neutrophil elastase should help to prevent stress-induced gastric mucosal injury.

6-Ketoprostaglandin F1 alpha↗

Role of leukocytes in spinal cord injury in rats.

Spinal cord injury (SCI) is a serious condition that produces life-long disabilities. Only limited therapeutic measures are currently available for its treatment. This review describes the role of leukocytes in pathologic mechanisms of trauma-induced SCI in rats, which contributes to new understanding of the pathologic process involved in SCI and could lead to the development of new therapeutic strategies by which leukocyte activation can be regulated. SCI induced by trauma is a consequence of an initial physical insult that is followed by a progressive injury process which involves various pathochemical events that lead to tissue destruction. Therapeutic intervention in SCI should therefore be directed at reducing or alleviating this secondary process. Although the mechanisms are not fully understood, progressive vascular events, especially activated neutrophil-induced endothelial cell damage, have been shown to be implicated. We have found that some therapeutic agents, which inhibit leukocyte activation directly or indirectly, alleviate the motor disturbances observed in a rat model of SCI. Methylprednisolone (MPS) and GM1 ganglioside, which are the only two pharmacological agents currently clinically available for treatment of acute SCI, do not inhibit neutrophil activation in this rat model. Taken together, these observations raise a possibility that pharmacological agents that inhibit leukocyte activation used in conjunction with MPS or GM1 may have a synergistic effect in the clinical treatment of traumatic SCI in humans.

Animals↗

Activated protein C reduces the ischemia/reperfusion-induced spinal cord injury in rats by inhibiting neutrophil activation.

OBJECTIVE: To examine whether activated protein C (APC) reduces spinal cord injury in rats by inhibiting neutrophil activation after the transient ischemia. SUMMARY BACKGROUND DATA: Ischemic spinal cord injury is an important pathologic mechanism leading to the paraplegia observed after surgery to repair aortic aneurysms. Activated neutrophils play a pivotal role in the development of ischemia/reperfusion-induced tissue injury. Recently, the authors have reported that APC, a physiologic anticoagulant, prevents lipopolysaccharide-induced pulmonary vascular injury by inhibiting neutrophil activation. These observations strongly suggest that APC reduces ischemia/reperfusion-induced spinal cord injury by inhibiting neutrophil activation. METHODS: In rats, spinal cord ischemia was induced by using a balloon catheter placed into the aorta. After the transient ischemia, survival and motor function were evaluated, and histologic examination of the spinal cord was performed by using both hematoxylin-and-eosin staining and 2,3,5, -triphenyltetrazolium chloride (TTC) staining 24 hours after the ischemia. Tissue levels of myeloperoxidase and cytokines, including tumor necrosis factor-alpha (TNF-alpha) and rat interleukin-8, were measured in six experimental groups: sham-operated, control, APC (100 microg/kg, intravenous), dansyl glutamyl-glycyl-arginyl chloromethyl ketone-treated activated factor X (DEGR-F.Xa), a selective inhibitor of thrombin generation (1 mg/kg, intravenous), nitrogen mustard-induced leukocytopenia, and diisopropyl fluorophosphate-treated APC (DIP-APC), active site-blocked APC (100 microg/kg, intravenous). APC, DEGR-F.Xa, and DIP-APC were administered intravenously 30 minutes before aortic occlusion. Control and leukocytopenic rats received saline instead of other drugs. RESULTS: Pretreatment with APC significantly reduced motor disturbances compared with those in control animals. In contrast, neither DEGR-F.Xa nor DIP-APC had any effect. Microinfarctions, evidenced by the absence of TTC staining and histologic change, were markedly reduced in animals given APC. The increases in the tissue levels of TNF-alpha, rat interleukin-8, and myeloperoxidase in the ischemic part of the spinal cord were significantly reduced in animals that received APC. These levels were not reduced in rats given DEGR-F.Xa or DIP-APC. Leukocytopenia produced effects similar to those of APC. CONCLUSIONS: APC reduced the ischemia/reperfusion-induced spinal cord injury by inhibiting neutrophil activation. The therapeutic mechanisms of APC might depend on its inhibitory effect on the production of TNF-alpha, which is a potent activator of neutrophils. Although the anticoagulant effects of APC might not be related to its ability to inhibit TNF-alpha production, its serine protease activity appears to be essential in the therapeutic mechanism. APC appears to have potential as a therapeutic agent for prevention of spinal cord injury in patients undergoing aortic aneurysm repair.

Animals↗

Inhibition of neutrophil activation by ranitidine contributes to prevent stress-induced gastric mucosal injury in rats.

OBJECTIVE: Activated neutrophils play a critical role in stress-induced gastric mucosal injury. We investigated the effect of ranitidine, an H2-receptor antagonist, on neutrophil activation in vitro and in rats with stress-induced gastric mucosal injury. DESIGN: Prospective, randomized, blinded, controlled study. SETTING: Research laboratory at a university medical center. INTERVENTIONS: Effects of ranitidine on neutrophil elastase release, production of O2-, intracellular calcium concentration and expression of adhesion molecules CD11b and CD18 were examined in human neutrophils in vitro. The effect of ranitidine (30 mg/kg iv) on the development of gastric mucosal injury, neutrophil accumulation, and lipid peroxidation was investigated in male Wistar rats subjected to water-immersion restraint stress. MEASUREMENTS AND MAIN RESULTS: Ranitidine inhibited the release of neutrophil elastase as well as the production of O2-, the increase in the concentrations of intracellular calcium, a second messenger of neutrophil activation, and increases in CD11b and CD18 expression, in activated neutrophils. Ranitidine did not affect the expression of E-selectin on endothelial cells in vitro. Ranitidine significantly inhibited gastric accumulation of neutrophils and gastric mucosal lipid peroxidation in rats subjected to stress. Although oral administration of acid reversed the preventive effect of pirenzepine, an anti-cholinergic drug that inhibits gastric acid secretion, it did not affect the preventive effect of ranitidine. Leukocytopenia produced effects similar to those of ranitidine in animals subjected to stress. CONCLUSIONS: Inhibition of neutrophil activation and gastric acid secretion by ranitidine might contribute to reduce stress-induced gastric mucosal injury.

Animals↗

The prevention of lipopolysaccharide-induced pulmonary vascular injury by pretreatment with cepharanthine in rats.

Cepharanthine, a biscoclaurine alkaloid, has been shown to inhibit leukocyte activation in vitro. To determine whether cepharanthine may be of use in the treatment of acute respiratory distress syndrome (ARDS), we investigated its effect on lipopolysaccharide (LPS)-induced pulmonary vascular injury in rats, in which activated leukocytes have been implicated. Intravenous administration of LPS (5 mg/kg) induced pulmonary vascular injury, as indicated by increases in both the pulmonary vascular permeability and the lung wet/dry weight ratio. LPS-induced pulmonary vascular injury was significantly less in animals given cepharanthine (10 mg/kg) intraperitoneally. Cepharanthine significantly inhibited the LPS-induced increases in plasma tumor necrosis factor-alpha (TNF-alpha) concentrations in vivo and significantly inhibited the production of TNF-alpha by LPS-stimulated monocytes in vitro. Cepharanthine also inhibited the functions of activated neutrophils in vitro such as neutrophil elastase release, oxygen radical generation, and neutrophil aggregation, probably by inhibiting a rise in the intracellular free calcium concentration. These findings suggest that cepharanthine prevents LPS-induced pulmonary vascular injury by inhibiting leukocyte activation.

Alkaloids↗

Recombinant tissue factor pathway inhibitor reduces lipopolysaccharide-induced pulmonary vascular injury by inhibiting leukocyte activation.

Tissue factor pathway inhibitor (TFPI) is an important physiologic inhibitor of the extrinsic pathway of the coagulation system. We investigated whether recombinant TFPI (rTFPI) could reduce pulmonary vascular injury by inhibiting leukocyte activation in rats given lipopolysaccharide (LPS). Pre- or posttreatment of animals with rTFPI significantly inhibited LPS-induced pulmonary vascular injury, as well as coagulation abnormalities. rTFPI significantly inhibited increases in lung tissue levels of tumor necrosis factor (TNF)-alpha, cytokine-induced neutrophil chemoattractant, and myeloperoxidase. Expression of TNF-alpha messenger RNA in the lung after LPS administration was significantly reduced by rTFPI administration. However, neither DX-9065a, a selective inhibitor of Factor Xa, nor recombinant Factor VIIa treated with dansyl-glutamylglycylarginyl-chloromethyl ketone, a selective inhibitor of Factor VIIa, had any effects on LPS-induced pulmonary vascular injury despite their potent anticoagulant effects. rTFPI significantly inhibited TNF-alpha production by LPS-stimulated monocytes in vitro. rTFPI also significantly inhibited several formyl-Met-Leu-Phe-induced neutrophil functions, as well as increases in the expression of CD11b and CD18 on the neutrophil cell surface in vitro. Additionally, rTFPI inhibited increases in levels of intracellular calcium, a second messenger of neutrophil activation, in formyl-Met-Leu-Phe-stimulated neutrophils in vitro. These results strongly suggested that rTFPI reduces pulmonary vascular injury by inhibiting leukocyte activation, as well as coagulation abnormalities in rats given LPS.

Animals↗

Purification and characterization of factor VII inhibitor found in a patient with life threatening bleeding.

We recently observed a patient with acquired inhibitor-induced F.VII deficiency whose plasma level of F.VII was < 1.0%. However, the biochemical nature of the inhibitor has not yet been clarified. In the present study, we purified the F.VII inhibitor from the patient's plasma by using activated F.VII (F.VIIa)-conjugated gel and characterized the inhibitor. The results showed that the inhibitor comprised two kinds of antibodies: one was eluted with EDTA (antibody 1) and the other with glycine-HCl buffer (pH 2.3) (antibody 2) from the F.VIIa affinity gel. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting analysis of these inhibitors demonstrated that both antibodies had features of immunoglobulin G1 (IgG1) with kappa and lambda-light chains. Antibody 1 bound to the immobilized F.VIIa with a high affinity in the presence of calcium ion, while antibody 2 bound to the F.VIIa very weakly and the binding was independent of calcium ion. Immunoblotting analysis demonstrated that antibody 1 bound to the light chain of F.VIIa after reduction with 2-mercaptoethanol, while it did not react with either the gamma-carboxyglutamic acid (Gla)-domainless light chain of F.VIIa or the heavy chain with the protease domain. Antibody 1 markedly inhibited the activity of tissue factor-F.VIIa complex. Based on these observations, it is suggested that F.VIIa autoantibody (antibody 1) recognizes the calcium-dependent conformation within or near the Gla domain and inhibits F.VIIa activity by interacting with the light chain.

Antibodies↗

Neuroprotection by recombinant thrombomodulin.

We examined whether recombinant human soluble thrombomodulin (rhs-TM) reduces compression trauma-induced spinal cord injury through protein C activation in rats. Administration of rhs-TM, either before or after the induction of spinal cord injury (SCI), markedly reduced the resulting motor disturbances. However, neither rhs-TM pretreated with an anti-rhs-TM monoclonal antibody (MAb) F2H5, which inhibits thrombin binding to rhs-TM, nor those pretreated with MAb R5G12, which selectively inhibits protein C activation by rhs-TM, prevented the motor disturbances. Intramedullary hemorrhages, observed 24 h after trauma, were significantly reduced in animals given rhs-TM. The increase in the tissue levels of tumor necrosis factor-alpha (TNF-alpha), TNF-alpha mRNA expression, and the accumulation of leukocytes in the damaged segment of the spinal cord were significantly inhibited in animals receiving rhs-TM, but these effects were not observed following administration of rhs-TM pretreated with MAb R5G12 or MAb F2H5. Leukocytopenia and activated protein C all produced effects similar to those of rhs-TM. These findings suggest that rhs-TM prevents compression trauma-induced SCI by inhibiting leukocyte accumulation by reducing the expression of TNF-alpha mRNA and such therapeutic effects of rhs-TM could be dependent on its protein C activation capacity. Findings further suggest that thrombomodulin can be implicated not only in the coagulation system but in regulation of the inflammatory response.

Animals↗