Katanin, the microtubule-severing ATPase, is concentrated at centrosomes

The assembly and function of the mitotic spindle involve specific changes in the dynamic properties of microtubules. One such change results in the poleward flux of tubulin in which spindle microtubules polymerize at their kinetochore-attached plus ends while they shorten at their centrosome-attached minus ends. Since free microtubule minus ends do not depolymerize in vivo, the poleward flux of tubulin suggests that spindle microtubules are actively disassembled at or near their centrosomal attachment points. The microtubule-severing ATPase, katanin, has the ability actively to sever and disassemble microtubules and is thus a candidate for the role of a protein mediating the poleward flux of tubulin. Here we determine the subcellular localization of katanin by immunofluorescence as a preliminary step in determining whether katanin mediates the poleward flux of tubulin. We find that katanin is highly concentrated at centrosomes throughout the cell cycle. Katanin's localization is different from that of gamma-tubulin in that microtubules are required to maintain the centrosomal localization of katanin. Direct comparison of the localization of katanin and gamma-tubulin reveals that katanin is localized in a region surrounding the gamma-tubulin-containing pericentriolar region in detergent-extracted mitotic spindles. The centrosomal localization of katanin is consistent with the hypothesis that katanin mediates the disassembly of microtubule minus ends during poleward flux.

Identification of a putative target for Rho as the serine-threonine kinase protein kinase N

Rho, a Ras-like small guanosine triphosphatase, has been implicated in cytoskeletal responses to extracellular signals such as lysophosphatidic acid (LPA) to form stress fibers and focal contacts. The form of RhoA bound to guanosine triphosphate directly bound to and activated a serine-threonine kinase, protein kinase N (PKN). Activated RhoA formed a complex with PKN and activated it in COS-7 cells. PKN was phosphorylated in Swiss 3T3 cells stimulated with LPA, and this phosphorylation was blocked by treatment of cells with botulinum C3 exoenzyme. Activation of Rho may be linked directly to a serine-threonine kinase pathway.

Changes in urinary nitrate and nitrite during treatment of ulcerative colitis

The urinary excretion rates of nitrate (NO3) and nitrite (NO2) were monitored in 14 patients with active ulcerative colitis during treatment using hydrocortisone and sulfasalazine. During the active phase of the disease, the NO3 excretion was significantly higher in the patients than in healthy controls (n = 6, p < 0.05), although it varied considerably among the patients. During the healing phase, the NO3 excretion decreased concurrently with improvement of symptoms and colorectal ulceration, but the NO2 excretion increased. During the inactive phase of the disease, the NO3 and NO2 excretions were significantly lower than during the active phase, and the NO2/NO3 ratio resembled that in the healthy controls. In contrast, a patient who failed to respond to treatment showed continuously high NO3 and NO2 excretion rates. These results indicate that urinary NO3 and NO2 excretions vary with the disease state in ulcerative colitis.

Perinatal development of action potential propagation in cat rubrospinal axons

1. The development of action potential conduction was studied by intracellular recording of antidromic spikes in cat rubrospinal cells. 2. The distance between the C1 and L1 spinal segments increased linearly from 5.6 cm at embryonic day (E) 59 to 9.8 cm at postnatal day (P) 30. 3. The conduction time from the C1 segment to the rubrospinal neuron soma, estimated from antidromic spike latency evoked by stimulation of the C1 segment, decreased rapidly prior to birth and then slowly thereafter. This coincided with a reduction in conduction time variation between cells. 4. The conduction time from the red nucleus to the L1 segment followed a similar time course during development. The conduction time reached the adult value by P30, at which time the spinal cord is only half the adult length. 5. The conduction velocity between the C1 and L1 segments increased monotonically between E59 and P30, from a low of 1 m s-1 to a maximum of 34 m s-1. 6. The rise time of rubrospinal neuron somadendritic spikes followed a developmental time course similar to that for conduction time. 7. Myelination of rubrospinal axons, as judged by the presence of myelinated segment spikes, began to occur prior to E59. 8. These findings suggest that development of action potential propagation in rubrospinal cells can be divided into an early and a late stage: conduction time reaches the adult value during the early stage, i.e. by the first postnatal month, and is maintained during the late stage. We propose that myelination, axon diameter increase and maturation of membrane properties act to reduce conduction time to adult values during the early stage, while a proportional increase in fibre diameter with axonal length results in a constant conduction time during the late stage.

[Effect of inhaled steroid on bone metabolism in the treatment of bronchial asthma]

In order to clarify the effects of longterm inhaled steroid therapy on bone metabolism, we examined 72 patients with bronchial asthma treated mainly with BDP (beclomethasone dipropionate). Multiple scanning X-ray photodensitometry was used to evaluate the degree of bone mineral loss. Osteocalcin, alkaline phosphatase (total and type III) was measured as a marker of bone synthesis and urinary pyridinoline, and deoxy-pyridinoline was measured as a marker of bone resorption. There was age related bone mineral loss. Urinary pyridinoline increased with aging. Treatment related bone mineral loss was not observed either in cases treated with BDP or in cases treated with continual oral steroids. Urinary pyridinoline and deoxy-pyridinoline decreased in patients treated with larger doses of for longer periods with BDP. Serum osteocalcin levels were lower in patients on continual oral corticosteroids. We conclude that inhaled steroid do not deteriorate bone metabolism in patients with bronchial asthma, when used appropriately.

Phenotypic differences of CD34-positive stem cells harvested from peripheral blood and bone marrow obtained before and after peripheral blood stem cell collection

Using two-color flow cytometry, we analyzed the subpopulations of CD34+ stem and progenitor cells in the blood and bone marrow from 10 patients with hematological malignancies. Peripheral blood mononuclear cells (PBMNC) harvested after chemotherapy (high-dose Ara C and VP-16) and rhG-CSF, and BM mononuclear cells, which were obtained before chemotherapy (BMMNCbefore) and after the stem cell collection (BMMNCafter) were isolated by Ficoll-Hypaque centrifugation. The purified cells were stained with FITC-conjugated anti-CD34 antibody and one of the following PE-conjugated antibodies: anti-CD7, CD10, CD11b, CD11c, CD13, CD19, CD33, CD38, CD45RO, CD56, and HLA-DR. CD34+ PBMNC harvested and the CD34+ BMMNCafter expressed CD13 and CD33 more frequently than CD34+ BMMNCbefore but expressed CD10 and CD19 less frequently than CD34+ BMMNCbefore. These data suggested that harvested PBMNC contain more myeloid lineage committed progenitors than BMMNCbefore, which might contribute to the rapid recovery of neutrophils after peripheral blood stem cell transplantation. No significant phenotypic differences of CD34+ cells between harvested PBMNC and BMMNCafter were observed except for the expression of CD11c. CD34+ PBMNC harvested coexpressed CD11c more frequently than both CD34+ BMMNCbefore and CD34+ BMMNCafter, which expression might be associated with commitment to the monocyte lineage.

Reconstitution of lymphocyte subsets after peripheral blood stem cell transplantation: two-color flow cytometric analysis

The reconstitution of lymphocyte subsets after high-dose chemotherapy followed by peripheral blood stem cell transplantation (PBSCT) was studied using two-color flow cytometry in 14 patients with acute leukemia (four AML and two ALL) and malignant lymphoma (six NHL and two HD). The CD3+HLA-DR+ lymphocytes (activated T cells) and CD8+ lymphocytes increased markedly by 4 weeks after PBSCT. Most of the increased CD8+ lymphocytes were CD11b-, S6F1+ cells and CD8+CD11b+ cells remained low throughout the follow-up period. The CD4+ lymphocytes remained below the normal range up to 34 weeks after PBSCT. The ratio of CD4+ to CD8+ lymphocytes (CD4/CD8 ratio) transiently increased and then decreased below 1.0 at 2 weeks after PBSCT. The CD19+ lymphocytes and the CD3-CD16+CD56+ lymphocytes returned to normal levels in the early period. The CD4+CD45RA+ lymphocytes (suppressor-inducer) decreased to below the normal range, while the CD4+CD45RO+ lymphocytes (helper-inducer) increased more rapidly than the CD4+CD45RA+ lymphocytes. This study shows that an immunosuppressed state exists after PBSCT as is seen after bone marrow transplantation (BMT) and that B cell reconstitution is more rapid in PBSCT than in BMT.

[Aggressive myeloma with subcutaneous tumor and pericardial involvement]

A 67-year-old male was admitted to our hospital because of anemia, thrombocytopenia, and renal failure. On admission he showed splenomegaly and elevated serum LDH level. Bone marrow showed hypercellularity with massive infiltration of lymphoblastoid cells. He was diagnosed as having multiple myeloma (BJ-kappa, stage IIIB). He transiently responded to intensive chemotherapy (VAD, MP, IFN alpha) but relapsed with multiple subcutaneous tumors and pericardial effusion. This is a rare case that the myeloma cell invasion to pericardial space was diagnosed before his death. The level of interleukin 6 (IL-6) in pericardial effusion was 16382 pg/ml, and the myeloma cells obtained from the pericardial effusion responded to IL-6, which suggested that high level of IL-6 closely related to the proliferation of myeloma cells in this case.

Effect of granulocyte colony-stimulating factor on hematopoietic recovery after peripheral blood progenitor cell transplantation

To examine the effect of granulocyte colony-stimulating factor (G-CSF) on hematopoietic recovery after high-dose chemotherapy and peripheral blood progenitor cell transplantation (PBPCT), 20 patients with hematologic malignancies were divided into two groups. One group was given G-CSF at a daily dose of 50 micrograms/m2 subcutaneously, the other received no G-CSF. Neutrophil recovery was accelerated in the G-CSF treated patients and exceeded 0.5 x 10(9)/l at a median of 10 days post-PBPCT compared with 14 days in the control group (p < 0.01). This reduction led to a decrease in antibiotic use and a trend toward fewer febrile days in the G-CSF treated group.

Multifunctional effects of anticomplementary agent K-76 on carrageenan-induced colitis in the rabbit

In this study the effect of K-76, a sesquiterpene compound with anticomplementary activity isolated from a fungus culture, on carrageenan-induced colitis was studied from biochemical, histological and immunohistopathological aspects. K-76 suppressed epithelial cell loss, crypt abscess formation, inflammatory cell infiltration, mucosal atrophy, and ulceration. Immunohistochemical examination of the colonic mucosa showed that the number of IgG- and IgM-positive plasma cells and the staining intensity for IgG and C3 were increased in carrageenan-induced colitis, but these changes were inhibited by K-76. Besides, serum mucoprotein concentrations and CH50 levels were lower in the animals treated with carrageenan alone. K-76 exerted multifunctional activity, although its mechanisms of action remain obscure.

Autoimmune thrombocytopenia following peripheral blood stem cell autografting

A 22-year-old woman diagnosed as AML (M3) received myeloablative chemotherapy followed by autologous peripheral stem cell transplantation (PBSCT). Rapid hematopoietic reconstitution occurred. By day 10, the neutrophil count was > 0.5 x 10(9)/l and the platelet count > 50 x 10(9)/l. The platelet count was 145 x 10(9)/l on day 20. Purpura developed on the anterior chest and legs on day 50, at which time the platelet count fell to 17 x 10(9)/l. The BM was hypocellular with an increase in megakaryocytes. Platelet-associated IgG (PAIgG) was 88.1 ng/10(7) platelets (normal range 9-25 ng/10(7)); a diagnosis of idiopathic thrombocytopenic purpura (ITP) was made. Prednisolone administration led to an increase in the platelet count and a decrease in PAIgG. Analysis of lymphocyte subsets revealed an increased number of CD3+ gamma/delta T cells. It is postulated that the thrombocytopenia in this case was due to an autoimmune mechanism such as ITP.

[Acute basophilic leukemia: a case report]

A 56-year-old woman was admitted to our hospital in January, 1990 because of fever and petechiae. Leukocyte count of peripheral blood showed 41,000/microliters with 89% immature cells, and bone marrow was normocellular with 96.2% immature cells. They were medium to large in size, positive for peroxidase staining, CD-13 and CD-33. Half of them contained azurophilic granules. They showed metachromasia by toluidine blue, contained basophilic granules in electron microscopic examination and reacted to G-CSF, G-CSF and IL-3. She was diagnosed as acute basophilic leukemia and treated with BHAC-DMP and B triple-V regimen, but remission was not attained. She died of peritonitis due to gastrointestinal tract perforation and pneumonia in March, 1990. This is the fifteenth case of acute basophilic leukemia reported in Japan, and the hematological examinations performed in this patient were demonstrated.

Trilineage response in severe aplastic anemia following long-term therapy with recombinant human granulocyte colony-stimulating factor

We investigated the effects of long-term therapy with recombinant human granulocyte colony-stimulating factor (rhG-CSF) in a 69-year-old man with severe aplastic anemia (SAA). The patient was too old to receive a bone marrow transplantation, and high-dose methylprednisolone and antilymphocyte globulin were ineffective. We administered rhG-CSF in combination with metenolone acetate. Trilineage blood cell components were recovered 6 months later. These findings suggest that long-term G-CSF therapy may be beneficial in patients with SAA who are not candidates for bone marrow transplantation.

Developing corticorubral axons of the cat form synapses on filopodial dendritic protrusions

Developing neurons transiently grow numerous spine- or filopodium-like dendritic protrusions (SLDPs). Electron microscopy on identified input and intracellular staining of postsynaptic cells were performed to gain insight into their significance. Newborn kitten-corticorubral axons, labelled with biocytin, commonly made synapses on SLDP, often multiply invaginated by the SLDPs. Correspondingly, intracellularly labelled kitten rubrospinal cells had numerous SLDPs. Taking into account that corticorubral synapses are largely formed on dendritic shafts in adult cats, it is likely that the SLDPs play some important role in the development of corticorubral synapses. We hypothesize that rubrospinal cells elongate SLDPs searching for corticorubral axons to form synapses.

Collection of peripheral blood stem cells mobilized by high-dose Ara-C plus VP-16 or aclarubicin followed by recombinant human granulocyte-colony stimulating factor

We developed an effective method for harvesting large numbers of peripheral blood stem cells (PBSC) for use in autotransplantation. Twenty patients with hematological malignancies were treated with high doses of Ara-C (12 g/m2) and VP-16/aclarubicin followed by administration of rhG-CSF (50 micrograms/m2). The optimal time for starting PBSC collection was determined by monitoring the CD34-positive stem cells in blood using immunomagnetic beads. PBSC were collected with a CS-3000 blood cell separator. A total blood volume between 7000 and 9000 ml was processed in each apheresis. Under these conditions, a total of 64 apheresis procedures was performed in the 20 patients. The mean numbers of mononuclear cells and of CFU-GM harvested per apheresis were 4.1 x 10(8)/kg and 110 x 10(4)/kg, respectively. A number of CFU-GM sufficient for engraftment (> 30 x 10(4)/kg) could be harvested by a single apheresis in 15 of the 20 patients. So far, 11 patients have been transplanted with PBSC and obtained rapid hematopoietic recovery. The median time to recover neutrophils more than 0.5 x 10(9)/l was 10 days, and that for platelets 50 x 10(9)/l was 11 days. This method for harvesting large numbers of PBSC allows safer autotransplantation in patients with chemoradiosensitive tumors, and is applicable to older patients.

New treatment of ulcerative colitis with K-76

The complement inhibitor K-76 (Otsuka Pharmaceutical Co., Osaka, Japan) was clinically evaluated as a new drug for treatment of active stage ulcerative colitis (UC). As monotherapy, K-76 proved effective in four of five cases. Furthermore, in patients with active stage UC that continued despite administration of corticosteroid hormone and salicylazosulphapyridine (so-called refractory UC), concomitant administration of K-76 was effective in seven of 21 cases. Thus, we believe that the multifunctional agent K-76 will provide clinicians with a new therapeutic approach to inflammatory bowel diseases, including UC and Crohn's disease.

Blue rubber bleb nevus syndrome with disseminated intravascular coagulation and thrombocytopenia: successful treatment with high-dose intravenous gammaglobulin

A 63-year-old woman was diagnosed as having blue rubber bleb nevus syndrome (BRBNS) with disseminated intravascular coagulation (DIC). Hematological data showed typical DIC: PT 13.2 sec, activated PTT 55.3 sec, fibrinogen 20 mg/100 ml, FDP-E 928 ng/ml, D-dimer 3,477 ng/ml, platelet count 25 x 10(3)/microliters. Although hypofibrinogenemia was successfully controlled by the continuous infusion of heparin, 10,000 units/day, thrombocytopenia has continued. Based on shortened platelet life span, high level of platelet associated IgG, and increased number of megakaryocyte in the bone marrow, the thrombocytopenia was thought to be due to antiplatelet antibody. Her platelet count returned to normal after intravenous infusion of high-dose gamma globulin (IVIg, Sandoz) at the dose of 400 mg/kg for 2-5 days, while corticosteroid, Gabexate mesilate, synthetic thrombin inhibitor MD-805, urinastatin and warfarin had no effect. Thus, DIC or thrombocytopenia may become a serious complication in some patients with BRBNS and IVIg may be useful for correcting thrombocytopenia in the patient.

Predictive factors for the response of ulcerative colitis patients during the acute-phase treatment

Twenty-six consecutive admissions of 24 patients with severe ulcerative colitis (UC) hospitalized in our Department at some time between January 1983 and December 1988 were studied to identify factors useful in the prediction of response to medical treatment in the acute inflammatory phase of this disease. Results of laboratory tests (white blood cells, red blood cells, platelet count, hemoglobin, erythrocyte sedimentation rate, total protein, albumin, alpha 2-microglobulin, cholinesterase, total cholesterol, and triglycerides) and of endoscopic findings (extent of disease, progress of the lesions, sparing of the rectum, and presence of geographic ulcers, longitudinal ulcers, and polypoid mucosal tags) were analyzed for any relationship with the effect of medical treatment during the acute phase. The effect of treatment was evaluated in terms of days it took for a severe condition to improve to an intermediate one defined by Truelove and Witts' categories for UC severity. C-Reactive protein, nutritive condition (total protein, albumin, and cholinesterase), extent of the lesions, and existence of polypoid mucosal tags provide predictive factors useful in the management of UC during the acute phase.