Tomoe Hayashi

Selective inducible nitric oxide synthase inhibition attenuates organ dysfunction and elevated endothelin levels in LPS-induced DIC model rats

Summary.  We examined the role of nitric oxide (NO) produced by an inducible isoform of NO synthase (iNOS) using N[6]‐(iminoethyl)‐lysine (L‐NIL), a selective iNOS inhibitor, in the rat model of lipopolysaccharide (LPS)‐induced disseminated intravascular coagulation (DIC) and investigated changes in organ function, plasma levels of NOX (metabolites of NO) and endothelin. We induced experimental DIC by the sustained infusion of 30 mg kg−1 LPS for 4 h via the tail vein. We then investigated the effect of L‐NIL (6 mg kg−1, from − 0.5 to 4 h) on LPS‐induced DIC. Blood was withdrawn at 4 and 8 h, and all four groups (LPS with or without L‐NIL at 4 and 8 h) consisted of eight rats. Three of the animals in the 8‐h LPS group died, and we examined blood samples from five rats in this group. None of the other rats died. The LPS‐induced elevation of creatinine, alanine aminotransferase, glomerular fibrin deposition and plasminogen activator inhibitor was significantly suppressed by L‐NIL coadministration, although L‐NIL did not affect the platelet count, fibrinogen concentration or the level of thrombin–antithrombin complex. Moreover, plasma levels of the D‐dimer that reflect the lysis of cross‐linked fibrin were significantly increased by L‐NIL coadministration in the LPS‐induced DIC model. Plasma levels of NOX and endothelin were obviously increased by LPS infusion. However, both levels were significantly suppressed in the LPS + L‐NIL group, when compared with the LPS group. Although mean arterial pressure (MAP) was significantly decreased between 2 and 8 h compared with the control in the LPS group, this depression was significantly attenuated in the LPS + L‐NIL group. Our results suggest that NO induced by iNOS contributes to hypotension (depressed MAP), the progression of hepatic and renal dysfunction, microthrombus deposition and elevated endothelin levels in the rat model of LPS‐induced DIC.

Treatment of primary central nervous system lymphoma with induction of complement-dependent cytotoxicity by intraventricular administration of autologous-serum-supplemented rituximab

We describe an immunocompetent 19‐year‐old man with CD20‐positive primary central nervous system (CNS) lymphoma refractory to chemotherapy and irradiation. After intraventricular administration of rituximab, a chimeric anti‐CD20 monoclonal antibody, supplemented with autologous serum, a remarkable response developed to the CNS parenchymal lymphoma. Cytotoxicity assays showed that untreated patients serum with rituximab, but not that of heat‐inactivated patients serum with rituximab or rituximab alone, induced potent rituximab‐mediated cytotoxicity against tumor cells in the patients cerebrospinal fluid, suggesting induction of complement‐dependent cytotoxicity against CNS lymphoma. (Cancer Sci 2006; 97: 80 –83)

Successful treatment of Trichosporon fungemia in a patient with refractory acute myeloid leukemia using voriconazole combined with liposomal amphotericin B

Trichosporon fungemia is a rare and fatal fungal infection that occurs in patients with prolonged neutropenia associated with hematologic malignancies. A 21‐year‐old male developed Trichosporon fungemia during remission induction therapy for acute myeloid leukemia (AML). Although two courses of induction therapy failed to induce a remission of AML, combination therapy with voriconazole and liposomal amphotericin B (L‐AmB) followed by monocyte colony‐stimulating factor ameliorated the Trichosporon fungemia and enabled the patient to receive reduced‐intensity bone marrow transplantation (BMT) from his human leukocyte antigen‐A one‐locus mismatched mother. The patient achieved a durable remission after BMT without exacerbation of Trichosporon fungemia. The combination therapy with voriconazole and L‐AmB may therefore be useful in controlling Trichosporon fungemia associated with prolonged neutropenia after remission induction therapy for AML.

A case of acquired FXIII deficiency with severe bleeding symptoms

Summary.  Acquired factor XIII (FXIII) deficiency due to an autoantibody against FXIII is a very rare, yet potentially life‐threatening bleeding disorder. As the standard coagulation tests (prothrombin time and activated partial thromboplastin time) are normal, the specialized tests are required to make an accurate diagnosis. Here, we report a case of acquired FXIII deficiency with severe bleeding symptoms. A 75‐year‐old man was referred to our hospital because of severe bleeding tendency after a tooth extraction. Laboratory findings showed that routine coagulation studies were normal, but factor XIII (FXIII) activity was low (3%). The presence of FXIII inhibitor was detected with dot blotting studies. Although the bleeding tendency was very severe, it was successfully controlled by infusion of FXIII concentrates combined with immunosuppressive treatment (oral prednisolone). Fibrin cross‐linking study showed the significant delay of the γ‐chain dimer and α‐chain polymer formation. Western blotting revealed the marked decrease in FXIII‐A level. The mixing study of FXIII activity measured using amine‐incorporation assay showed the incomplete inhibition pattern. There seems to be little agreement as to the treatment strategy of acquired FXIII deficiency. In this patient, the use of FXIII concentrates was very useful in the initial treatment of bleeding symptom. The use of steroids was also effective in increasing FXIII activity without any serious complications.

Expression of annexin II in experimental abdominal aortic aneurysms

Annexin II is a receptor of tissue-type plasminogen activator (t-PA). We have previously identified annexin II by immunolocalization in human atherosclerotic abdominal aortic aneurysms (AAAs). To investigate possible interactions between annexin II and AAA development, we examined annexin II mRNA and protein expression in a rat model of experimental AAA. AAAs were induced in rats by transient aortic infusion of elastase. The rats were divided into three groups: a saline-treated control group, a group with 15-min elastase infusion, and a group with 30-min elastase infusion. The 15-min elastase-infused group had smaller aneurysms and more preserved media than the 30-min elastase-infused group. Immunohistochemistry showed that annexin II expression was increased in the thickened intima and media of AAA rats as compared with the media of control rats. Furthermore, annexin II was colocalized with macrophages and smooth muscle cells. Quantitative real-time polymerase chain reaction showed that annexin II mRNA levels were up-regulated only in the smaller aneurysm group compared with the control group. In contrast, t-PA mRNA levels were increased in both the 15- and 30-min elastase-infused groups as compared with the control group. These results demonstrate various levels of annexin II expression within the aortic wall of rats with experimental AAAs. It has been suggested that alteration of fibrinolytic activity regulated by annexin II within the aortic wall may be associated with aneurysm formation.

Expression of annexin II in human atherosclerotic abdominal aortic aneurysms

BACKGROUND Annexin II is a receptor for tissue-type plasminogen activator (t-PA) that converts plasminogen to plasmin. Although the fibrinolytic system is known to play an important role in the pathogenesis of abdominal aortic aneurysms (AAAs), the relationship between annexin II and AAA development is unknown. Therefore, we examined annexin II localization in the wall of human atherosclerotic AAAs. METHODS AND RESULTS Specimens from 13 patients undergoing elective repair of an AAA were taken. Annexin II expression was evaluated by immunohistochemical analysis. Immunostaining results were semiquantitatively analyzed using histology scores and WinROOF software based on staining intensity. The expression of annexin II was increased and the histology score was higher in the shoulder region of the atheromatous plaque than in the atheroma and fibrous plaque regions. Annexin II appeared to have greater expression and the histology score was higher in regions where the media was preserved. Furthermore, there was a significant inverse correlation between AAA size and histology score in the fibrous plaque region. CONCLUSIONS The present work demonstrates various levels of annexin II expression within the aneurysm wall. Therefore, we suggest that alteration of annexin II expression within the aortic wall may be associated with the development of an aneurysm.

Beneficial effects of urokinase on lipopolysaccharide-induced disseminated intravascular coagulation in rats: focus on organ function and endothelin levels.

In a rat model of lipopolysaccharide (LPS)-induced disseminated intravascular coagulation (DIC), we used urokinase (UK) in an attempt to clarify the role of fibrinolysis and to investigate changes in plasma endothelin levels. Two kinds of experiment were performed. The first one: experimental DIC was induced by sustained infusion of 30 mg/kg LPS for 4 h via the tail vein, and two doses of UK (2.0 or 10.0 IU/g/4.5 h) were administered to rats 30 min before infusion of LPS, after which UK infusion was continued for a further 4 h. The second one: experimental DIC was induced by sustained infusion of 1 mg/kg/10 min LPS for 10 min, and two doses of UK (2.0 or 10.0 IU/g/4 h) were administered to rats at 30 min after LPS infusion. The parameters described below were determined at 4 h in the first experiment, at 4 h and 8 h in the second one. The similar results were observed in both kinds of experiment. There were no significant differences in plasma thrombin-antithrombin complex, fibrinogen or platelet number among the three DIC groups, in both kinds of experiment. Plasma levels of D-dimer were significantly increased in the LPS + higher dose of UK group when compared with the LPS group. The increased plasma plasminogen activator inhibitor (PAI) activity seen in the LPS group was significantly suppressed in the groups receiving UK (especially higher dose of UK). In addition, the increased plasma levels of creatinine and alanine aminotransferase seen in the LPS group were significantly suppressed in the groups receiving UK (especially higher dose of UK). Plasma levels of endothelin, known to be a potent vasoconstrictive agent, were markedly elevated by LPS infusion, and were significantly suppressed in the groups receiving UK of both kinds of experiment, in a dose-dependent fashion compared with LPS group. Glomerular fibrin deposition was significantly suppressed in the groups receiving UK when compared with the LPS group. No manifestations of bleeding were observed in any of the groups. Enhanced fibrinolysis and depressed endothelin induced by UK thus appear to play an important role in preventing the development of organ failure in the LPS-induced DIC model.

Two case reports of inherited antithrombin deficiency: a novel frameshift mutation and a large deletion including all seven exons detected using two methods.

An inherited antithrombin deficiency is an autosomal dominant thrombotic disorder. We identified two pedigrees of inherited type I antithrombin deficiency and two responsible mutations in each. A novel 21–22delAA appeared to have caused a frameshift with a premature termination at amino acid +63 in one patient and a large deletion including all seven exons was identified by multiplex ligation-dependent probe amplification in the other. Some asymptomatic relatives of the second patient had the same mutation. The present findings support the value of using more than one method of gene analysis and of studying the families of probands with inherited thrombotic disorders.

Thrombosis Prediction Based on Reference Ranges of Coagulation-Related Markers in Different Stages of Pregnancy

Introduction: Careful monitoring of the hypercoagulable state is required during pregnancy. However, coagulation and fibrinolysis markers are not fully utilized because there are no reference values reflective of coagulation and fibrinolysis dynamics during pregnancy, which differ from the nonpregnant state. Methods: Changes in antithrombin (AT), fibrinogen (Fbg), prothrombin fragment 1+2 (F1+2), thrombin–antithrombin complex (TAT), soluble fibrin (SF), D-dimer (DD), and protein S (PS) were investigated in healthy pregnant women, and reference ranges in the early, mid, late, and end stages of pregnancy were established. Results: The AT was essentially constant throughout pregnancy. The Fbg, F1+2, TAT, and DD increased significantly as pregnancy progressed. In contrast, SF did not show a significant increase throughout the entire pregnancy period. Total PS antigen and total PS activity showed a corresponding decrease from early gestation. When test data in 3 cases in which deep vein thrombosis or intrauterine fetal death occurred during pregnancy were compared to the established reference ranges, all of the cases had multiple markers with values that exceeded the reference ranges. Conclusion: Establishing reference ranges for each week could potentially make it possible to evaluate abnormalities of the coagulation and fibrinolysis systems during pregnancy. Of note, SF might be a useful marker that reflects thrombus formation during pregnancy. Larger-scale studies will be required to establish reference ranges for every gestational week.

Isolated Hyperkalemia Associated with Cyclosporine Administration in Allogeneic Stem Cell Transplantation for Renal Cell Carcinoma

Two patients with advanced renal cell carcinoma underwent allogeneic hematopoietic stem cell transplantation and received cyclosporine (CSP) as part of their immunosuppressive therapy. Despite adequate renal function, both patients developed hyperkalemia. CSP was the only pharmaceutical agent to which this electrolyte abnormality could be attributed. Evaluation of renal tubule function suggested that CSP-associated isolated hyperkalemia resulted from tubular resistance to aldosterone. We propose that the presence of a single functional kidney may be a risk factor for isolated hyperkalemia due to CSP.