Masayoshi Johno

Role of neutrophils in spinal cord injury in the rat

Activated neutrophils are thought to be involved in tissue injury through the release of various inflammatory mediators. To understand the role of neutrophils in spinal cord injury, the effects of nitrogen mustard-induced leukocyte depletion and the administration of an anti-P-selectin monoclonal antibody on motor disturbances observed following spinal cord compression were examined in rats. Spinal cord injury was induced by applying a 20-g weight for 20 min at the level of the 12th thoracic vertebra, resulting in motor disturbances of the hindlimbs 24 h postcompression. Motor disturbances, evaluated using Tarlovs index, an inclined-plane test and climbing ability, were markedly attenuated in rats with nitrogen mustard-induced leukocytopenia. Administration of the anti-P-selectin monoclonal antibody, by which adhesion of activated neutrophils to endothelial cells may be inhibited, also attenuated motor disturbances. Histological examination revealed that intramedullary hemorrhages observed 24 h after compression at the 12th thoracic vertebra of the spinal cord were significantly attenuated in leukocytopenic animals and those which received the anti-P-selectin monoclonal antibody. The accumulation of neutrophils at the site of compression, as evaluated by measuring the tissue myeloperoxidase activity, significantly increased with time following the compression, peaking at 3 h postcompression. Spinal cord myeloperoxidase activity did not increase in sham-operated animals. Leukocyte depletion and administration of the anti-P-selectin monoclonal antibody both reduced the accumulation of neutrophils in the damaged spinal cord segment 3 h postcompression. These observations strongly suggest that activated neutrophils play an important role in compression-induced thoracic spinal cord injury and that a P-selectin-mediated interaction between activated neutrophils and endothelial cells may be a critical step in endothelial cell injury leading to spinal cord injury.

Role of neutrophil elastase in compression-induced spinal cord injury in rats.

We have previously demonstrated the importance of activated neutrophils in compression-induced spinal cord injury (SCI) in rats. In the present study, we investigate the action of neutrophil elastase in posttraumatic SCI, using two neutrophil elastase inhibitors (Eglin C and L658,758). SCI was induced by applying a 20-g weight to the spinal cord for 20 min at the level of T12, resulting in hindlimbs motor disturbances, which, when evaluated using a inclined-plane test, were significantly attenuated by Eglin C or L658,758. Histologic examination revealed that intramedullary hemorrhages observed 24 h after trauma were markedly attenuated in these agents. These inhibitors also significantly decreased neutrophil accumulation as shown by myeloperoxidase activity in the damaged spinal cord segment. Induction of leukocytopenia had the same effects as Eglin C or L658,758. These findings implicated neutrophil elastase in SCI. The enzyme may induce vascular damage leading to spinal cord ischemia.

Rebamipide Attenuates Indomethacin-Induced Gastric Mucosal Lesion Formation by Inhibiting Activation of Leukocytes in Rats

Granulocyte elastase released from activatedleukocytes plays an important role in leukocyteinfiltration. Since activated leukocytes have been shownto be involved in the pathogenesis of gastric mucosal lesion formation induced by nonsteroidalantiinflammatory drugs, inhibition of granulocyteelastase release from activated leukocytes may be usefulin the prevention of these lesions. Rebamipide, a novel antiulcer agent, inhibited granulocyte elastaserelease from activated neutrophils in vitro. Rebamipideand ONO-5046, a granulocyte elastase inhibitor, markedlyinhibited gastric mucosal lesion formation in rats. Gastric myeloperoxidase activity wassignificantly increased 3 hr after indomethacinadministration. This increase was significantlyinhibited by rebamipide and ONO-5046. Cimetidine did notinhibit granulocyte elastase release from activatedneutrophils. Although cimetidine markedly prevented theindomethacin-induced gastric mucosal lesion formation,it did not reduce the gastric myeloperoxidase activity. Therefore, unlike cimetidine, rebamipide mayprevent indomethacin-induced gastric mucosal lesionformation by inhibiting neutrophil activation.

Methylprednisolone Reduces Spinal Cord Injury in Rats Without Affecting Tumor Necrosis Factor-α Production

Methylprednisolone (MPS) is the only therapeutic agent currently available for traumatic spinal cord injury (SCI). However, little is known about its therapeutic mechanisms. We have demonstrated that tumor necrosis factor-alpha (TNF-alpha) plays a critical role in posttraumatic SCI in rats. Since MPS has been shown to inhibit TNF-alpha production in vitro, it is possible that MPS can reduce SCI by inhibiting TNF-alpha production. To examine this possibility, we investigated the effect of MPS on TNF-alpha production in injured segments of rat spinal cord. Leukocytopenia and high-dose intravenous administration of MPS markedly reduced the motor disturbances observed following spinal cord trauma. Both treatments also reduced the intramedullary hemorrhages observed histologically 24 hr posttrauma. Leukocytopenia significantly reduced tissue levels of both TNF-alpha mRNA and TNF-alpha, 1 and 4 hr posttrauma, respectively, and it also inhibited the accumulation of leukocytes in the injured segments 3 hr posttrauma, while MPS had no effects. Lipid peroxidation and vascular permeability at the site of spinal cord lesion were both significantly increased over time after the induction of SCI, peaking 3 hr posttrauma. These events were significantly reduced in animals with leukocytopenia and in those given anti-P-selectin monoclonal antibody compared to sham-operated animals. Administration of MPS significantly inhibited both the increase in lipid peroxidation and the vascular permeability. These findings suggested that MPS reduces the severity of SCI, not by inhibiting the production of TNF-alpha at the site of spinal cord trauma, but by inhibiting activated leukocyte induced lipid peroxidation of the endothelial cell membrane. This suggests that MPS may attenuate spinal cord ischemia by inhibiting the increase in endothelial permeability at the site of spinal cord injury.

Gabexate mesilate, a synthetic protease inhibitor, prevents compression-induced spinal cord injury by inhibiting activation of leukocytes in rats.

OBJECTIVE Gabexate mesilate is a synthetic protease inhibitor capable of inhibiting both coagulation and cytokine production by monocytes. To investigate whether gabexate mesilate is useful for the prevention of posttraumatic spinal cord injury, we examined its effect on compression trauma-induced spinal cord injury in rats. DESIGN Prospective, randomized, blinded, controlled study. SETTING Research laboratory at a university medical center. SUBJECTS Male Wistar rats weighing 300 to 350 g. INTERVENTIONS Spinal cord injury was induced by applying a 20-g weight extradurally to the spinal cord at the level of the 12th thoracic vertebra for 20 mins. Spinal cord injury was evaluated by assessing the motor function of the rats 24 hrs posttrauma. The accumulation of leukocytes and histologic changes in the injured spinal cord tissue also were examined. Rats received gabexate mesilate (10 or 20 mg/kg i.p.) 30 mins before or after the compressive trauma. The effects of heparin or an inactive derivative of activated factor X (a selective inhibitor of thrombin generation) on compressive trauma-induced spinal cord injury also were examined. Leukocytopenia was induced by the administration of nitrogen mustard. MEASUREMENTS AND MAIN RESULTS The motor disturbances observed following traumatic spinal cord compression, evaluated by Tarlovs score, and the accumulation of leukocytes in the injured tissue, evaluated by measuring tissue myeloperoxidase activity, were markedly reduced by leukocyte depletion induced by nitrogen mustard and by pre- or posttreatment of animals with gabexate mesilate. Neither heparin nor the inactive derivative of activated factor X prevented the motor disturbances and the accumulation of leukocytes. Histologic examination demonstrated that intramedullary hemorrhages observed 24 hrs after trauma at the 12th thoracic vertebra were significantly attenuated by nitrogen mustard-induced leukocytopenia and the administration of gabexate mesilate. CONCLUSIONS The compression trauma-induced spinal cord injury demonstrated by this model was mainly mediated by leukocytes. Gabexate mesilate prevented spinal cord injury not by inhibiting coagulation, but by inhibiting the activation of leukocytes.

rhs-TM prevents ET-induced increase in pulmonary vascular permeability through protein C activation

We have previously demonstrated that recombinant human soluble (rhs) thrombomodulin (TM) inhibits the endotoxin (ET)-induced increase in pulmonary vascular permeability by inhibiting leukocyte activation. In the present study, we examined whether rhs-TM could inhibit the ET-induced increase in pulmonary vascular permeability in rats by activating protein C. rhs-TM did not inhibit ET-induced increases in pulmonary vascular permeability when its protein C activation ability was selectively inhibited by a monoclonal antibody (MAb) against rhs-TM (MAb R5G12). Histological examination revealed that neutrophil infiltration in lung tissues after ET administration was significantly reduced by rhs-TM, but infiltration was not reduced by MAb R5G12-pretreated rhs-TM. ET-induced intravascular coagulation was prevented by rhs-TM and by MAb R5G12-pretreated rhs-TM. However, ET-induced coagulation was not prevented by rhs-TM that had been treated with MAb F2H5, which cannot bind thrombin or activate protein C. These observations strongly suggest that rhs-TM prevents ET-induced pulmonary vascular injury by inhibiting pulmonary accumulation of leukocytes through thrombin binding and the subsequent protein C activation and may prevent ET-induced intravascular coagulation through thrombin binding.We have previously demonstrated that recombinant human soluble (rhs) thrombomodulin (TM) inhibits the endotoxin (ET)-induced increase in pulmonary vascular permeability by inhibiting leukocyte activation. In the present study, we examined whether rhs-TM could inhibit the ET-induced increase in pulmonary vascular permeability in rats by activating protein C. rhs-TM did not inhibit ET-induced increases in pulmonary vascular permeability when its protein C activation ability was selectively inhibited by a monoclonal antibody (MAb) against rhs-TM (MAb R5G12). Histological examination revealed that neutrophil infiltration in lung tissues after ET administration was significantly reduced by rhs-TM, but infiltration was not reduced by MAb R5G12-pretreated rhs-TM. ET-induced intravascular coagulation was prevented by rhs-TM and by MAb R5G12-pretreated rhs-TM. However, ET-induced coagulation was not prevented by rhs-TM that had been treated with MAb F2H5, which cannot bind thrombin or activate protein C. These observations strongly suggest that rhs-TM prevents ET-induced pulmonary vascular injury by inhibiting pulmonary accumulation of leukocytes through thrombin binding and the subsequent protein C activation and may prevent ET-induced intravascular coagulation through thrombin binding.

Langerhans Cell Histiocytosis Presenting as a Varicelliform Eruption over the Entire Skin

A boy with skin eruptions resembling varicella and specific for Langerhans cell histiocytosis (LCH) is reported. At his initial visit when he was four months old, vesiculopustular lesions were present over the entire body; these had first appeared on the third day post partus. Histopathological, immunohistochemical, and electron microscopical examination confirmed the Langerhans cell phenotype and Birbeck granules in the responsible cells. He also had hydronephrosis, recurrent fever, and cutaneous bacterial infections. His parents refused further medical treatment and he died of diarrhea with cachexia about two years later. LCH may present diagnostic difficulties by manifesting as a skin eruption which resembles varicella.

Giant Basal Cell Carcinoma Associated with Systemic Amyloidosis

A large basal cell carcinoma, 39 times 26 cm in size, is presented as second in size only to the largest basal cell carcinoma documented (40 times 30 cm), reported by Beck and co‐workers (1). A 61‐year‐old Japanese male visited our clinic with a huge ulcerating tumor on the back. He had hidden the tumor for the previous 30 years. The tumor was histologically confirmed as basal cell carcinoma. The condition was associated with anemia, hypoproteinemia, and dyspnea, and with systemic amyloidosis in the skin, in the lymph nodes, and in the intestinal canal. On admission, the tumor had metastasized to the regional lymph nodes, and, about two years after the first operation, there were metastases to bone and lung, leading to death due to respiratory failure.

Hereditary perioral pigmented follicular atrophoderma associated with milia and epidermoid cysts.

Eight members of a single family all presented the characteristic changes of facial, especially perioral, pigmented follicular atrophoderma, with numerous milia and epidermoid cysts. For this condition, diagnosis at a glance may be possible because of the perioral cutaneous manifestations. Histopathological examination of follicular atrophoderma revealed proliferation of basaloid cells continuous with the epidermis and coarse collagen fibres, with a decreased density of elastic fibres around the basaloid cells. Two of the eight individuals also showed generalized hypohidrosis. The eight affected persons were the proband, her son, mother, uncle, two younger sisters, cousin and nephew; an autosomal dominant mode of transmission was suggested from this family tree. The patients’ symptoms resembled those of Bazex–Dupre´–Christol syndrome, except for the different distribution of the follicular atrophoderma and the absence of basal cell carcinoma and hypotrichosis. This disease may be an entirely new syndrome characterized by perioral pigmented follicular atrophoderma associated with milia and epidermoid cysts.

Serum levels of interleukin 6 in patients with pustulosis palmaris et plantaris.

Serum interleukin 6 (IL‐6) was measured in patients with pustulosis palmaris et plantaris by a fluorescent sandwich enzyme‐linked immunosorbent assay (ELISA) method. Increased production of IL‐6 was observed in 8 cases out of 10 showing numerous pustules in their active stage. Six cases were measured before and after tonsillectomy, and statistically significant reduction in the levels of IL‐6 paralleled an improvement in the disease activity. It is suggested that IL‐6 may be one of the mediators which link tonsillectomy to the activity of pustulosis palmaris et plantaris.