Expression of non-muscle type myosin heavy polypeptide 9 (MYH9) in mammalian cells

Myosin is a functional protein associated with cellular movement, cell division, muscle contraction and other functions. Members of the myosin super-family are distinguished from the myosin heavy chains that play crucial roles in cellular processes. Although there are many studies of myosin heavy chains in this family, there are fewer on non-muscle myosin heavy chains than of muscle myosin heavy chains. Myosin is classified as type I (myosin I) or type II (myosin II). Myosin I, called unconventional myosin or mini-myosin, has one head, while myosin II, called conventional myosin, has two heads. We transfected myosin heavy polypeptide 9 (MYH9) into HeLa cells as a fusion protein with enhanced green fluorescent protein (EGFP) and analyzed the localization and distribution of MYH9 in parallel with those of actin and tubulin. The results indicate that MYH9 colocalizes with actin stress fibers. Since it has recently been shown by genetic analysis that autosomal dominant giant platelet syndromes are MYH9-related disorders, our development of transfected EGFP-MYH9 might be useful for predicting the associations between the function of actin polymerization, the MYH9 motor domain, and these disorders.

Insufficient membrane fusion in dysferlin-deficient muscle fibers after heavy-ion irradiation

Recently, SJL/J mice have been used as an animal model in studies of dysferlinopathy, a spectrum of muscle diseases caused by defects in dysferlin protein. In this study we irradiated muscle fibers isolated from skeletal muscle of SJL/J mice with heavy-ion microbeam, and the ultrastructural changes were observed by electron microscopy. The plasma membrane of heavy-ion beam irradiated areas showed irregular protrusions and invaginations. Disruption of sarcomeric structures and the enhancement of autophagy were also observed. In addition, many vesicles of varying size and shape were seen to be accumulated just beneath the plasma membrane. This finding further supports the recent hypothesis that dysferlin functions as a membrane fusion protein in the wound healing system of plasma membrane, and that the defect in dysferlin causes insufficient membrane fusion resulting in accumulation of vesicles.

First measurement of the neutron beta asymmetry with ultracold neutrons

We report the first measurement of an angular correlation parameter in neutron beta decay using polarized ultracold neutrons (UCN). We utilize UCN with energies below about 200 neV, which we guide and store for approximately 30 s in a Cu decay volume. The interaction of the neutron magnetic dipole moment with a static 7 T field external to the decay volume provides a 420 neV potential energy barrier to the spin state parallel to the field, polarizing the UCN before they pass through an adiabatic fast passage spin flipper and enter a decay volume, situated within a 1 T field in a 2x2pi solenoidal spectrometer. We determine a value for the beta-asymmetry parameter A_{0}=-0.1138+/-0.0046+/-0.0021.

Long-term efficacy of Helicobacter pylori eradication in patients with idiopathic thrombocytopenic purpura: 7-year follow-up prospective study

Helicobacter pylori eradication is useful for improvement of a half of patients with idiopathic thrombocytopenic purpura (ITP), but its long-term therapeutic efficacy has not been elucidated. We investigated the long-term efficacy of H. pylori eradication in 30 cases with ITP that were included in our previous study regarding the association between H. pylori infection and ITP. Twenty-one cases were positive and nine cases were negative for H. pylori infection. H. pylori eradication therapy including secondary regimen was successful in 20 cases, half (responder) of whom showed ITP remission 1 month later. Nine responders could be followed up for a long time and did not show re-infection of H. pylori. Eight of nine needed no medication except for eradication therapy. Another case remained in remission for 1 year but thereafter needed a steroid therapy due to the recurrence. Eight nonresponders could be followed up for a long time. All these cases showed a bad clinical course even though they received the other post-treatments including steroid therapy. Three of nine H. pylori-negative cases underwent eradication therapy after obtaining the written informed consent, but none of them showed improvement. Of these three cases, two cases could be followed up. Only one case remained a remission although receiving corticosteroid as a post-treatment. Conditions of H. pylori-negative ITP cases were usually unstable for a long time. H. pylori eradication has a short-term efficacy for about half of H. pylori-positive ITP patients, and the responders to the eradication therapy may receive a long-term clinical benefit without other therapies.

Calcium channel blockers suppress cytokine-induced activation of human neutrophils

BACKGROUND

Neutrophils, in concert with proinflammatory cytokines, play an important role in the progression of atherosclerosis. Calcium channel blockers are commonly used in the treatment of hypertension, and their pleiotropic effects, other than the lowering of blood pressure, have been recently recognized.

METHODS

We studied the effects of various calcium channel blockers (amlodipine, nicardipine, cilnidipine, benidipine, efonidipine, nifedipine, azelnidipine, verapamil, and diltiazem; each being used at 5 and 10 micromol/l) on superoxide (O(2)(-)) release, migration, and signaling pathways in human neutrophils stimulated by granulocyte-macrophage colony-stimulating factor (GM-CSF) or tumor necrosis factor-alpha (TNF-alpha).

RESULTS

GM-CSF-induced O(2)(-) release was suppressed by amlodipine, nicardipine, and cilnidipine, whereas TNF-alpha-induced O(2)(-) release was suppressed by amlodipine, nicardipine, cilnidipine, benidipine, efonidipine, nifedipine, and azelnidipine. TNF-alpha-induced phosphorylation of extracellular signal-regulated kinase (ERK) and Akt, but not p38 mitogen-activated protein kinase (MAPK), was attenuated by nicardipine, cilnidipine, benidipine, efonidipine, and azelnidipine. By contrast, GM-CSF-induced phosphorylation of ERK, p38, and Akt was affected by none of the blockers. GM-CSF-induced neutrophil migration was also suppressed by amlodipine and nicardipine, but not by azelnidipine, when these blockers were assessed for their effect on neutrophil migration.

CONCLUSIONS

These findings suggest that (i) some calcium channel blockers can suppress cytokine-induced neutrophil activation, leading to possible prevention of the progression of atherosclerosis; and (ii) that activation of the ERK and phosphatidylinositol 3-kinase (PI3K)/Akt pathways, induced by TNF-alpha but not by GM-CSF, is selectively affected by some blockers.

Prophylactic fresh frozen plasma may prevent development of hepatic VOD after stem cell transplantation via ADAMTS13-mediated restoration of von Willebrand factor plasma levels

We initially conducted a multicenter, randomized trial (n=43), and subsequently a questionnaire study (n=209) of participating hospitals, to evaluate whether infused fresh frozen plasma (FFP) could prevent the occurrence of hepatic veno-occlusive disease (VOD) after stem cell transplantation (SCT). Forty-three patients were divided into two groups: 23 receiving FFP infusions and 20 not receiving it. VOD developed in three patients not receiving FFP. Plasma von Willebrand factor (VWF) antigen levels were lower at days 0, 7 and 28 after SCT in patients receiving FFP than in those not receiving it, whereas plasma ADAMTS13 activity (ADAMTS13:AC) did not differ between them. Plasma VWF multimer (VWFM) was demonstrated to be defective in the high approximately intermediate VWFM during the early post-SCT phase, but there was a significant increase in high VWFM just before VOD onset. This suggests that a relative enzyme-to-substrate (ADAMTS13/high-VWFM) imbalance is involved in the pathogenesis of VOD. To strengthen this hypothesis, the incidence of VOD was apparently lower in patients receiving FFP infusions than in those not receiving it (0/23 vs 3/20) in the randomized trial. Further, the results combined with the subsequent questionnaire study (0/36 vs 11/173) clearly showed the incidence to be statistically significant (0/59 vs 14/193, P=0.033).

Heavy ion microbeam irradiation induces ultrastructural changes in isolated single fibers of skeletal muscle

The effects of heavy ion microbeams on muscle fibers isolated from mouse skeletal muscles were examined by electron microscopy. The plasma membranes of heavy ion beam-irradiated areas of muscle fibers showed irregular protrusions and invaginations. In the cytoplasm, an irregular distribution of microfilaments was found near the plasma membrane. Sarcoplasmic reticula in the irradiated regions showed a distended appearance with flocculent material within the lumen. These changes were seen as early as 2 min after irradiation, and persisted until as late as 22 min after irradiation. Many autophagic vacuoles could be seen at 7 min after irradiation. At 22 min, the vacuoles became more prominent and showed more variety. These observations suggest that heavy ion beam irradiation causes disruption of the cellular architecture and the autophagy is involved in removal of this disruption.

Mast cells in diffuse large B-cell lymphoma; their role in fibrosis

AIMS

Mast cells (MCs) are associated with fibrosis in various diseases. MCs comprise two phenotypes: the MC(TC) phenotype contains tryptase and chymase, whereas the MC(T) phenotype contains tryptase. Interleukin (IL)-4 promotes the development of MC(TC) from the MC(T) phenotype. The aim of this study was to determine the relationship between MC phenotypes and fibrosis in diffuse large B-cell lymphoma (DLBCL).

METHODS AND RESULTS

We examined the distribution and density of MCs in 50 DLBCL and 20 reactive lymph nodes, and evaluated MC phenotypes and IL-4-expressing cells. To detect MCs, immunohistochemistry for tryptase and chymase was performed. The 50 DLBCLs were histologically divided into three groups: no fibrosis (32 cases), reticular type (eight cases) showing reticular fibrosis, and bundle type (10 cases) showing collagenous bundles. The density of tryptase-positive MCs was higher than that of chymase-positive MCs. The densities of tryptase-positive and chymase-positive MCs in fibrotic areas were significantly higher than those in the cellular areas in the reticular and bundle groups. Double immunostaining revealed that MCs in DLBCL comprised MC(T) and MC(TC) phenotypes. Chymase-positive MCs and T lymphocytes expressed IL-4. Although there were few chymase-positive MCs in reactive lymph nodes, the density of tryptase-positive MCs was not different from that in the 'no fibrosis' group.

CONCLUSIONS

Tryptase-positive and chymase-positive MCs are associated with fibrosis in DLBCL.

Reduced-intensity stem-cell transplantation for adult acute lymphoblastic leukemia: a retrospective study of 33 patients

Efficacy of reduced-intensity stem-cell transplantation (RIST) for acute lymphoblastic leukemia (ALL) was investigated in 33 patients (median age, 55 years). RIST sources comprised 20 HLA-identical related donors, five HLA-mismatched related, and eight unrelated donors. Six patients had undergone previous transplantation. Disease status at RIST was first remission (n=13), second remission (n=6), and induction failure or relapse (n=14). All patients tolerated preparatory regimens and achieved neutrophil engraftment (median, day 12.5). Acute and chronic graft-versus-host disease (GVHD) developed in 45 and 64%, respectively. Six patients received donor lymphocyte infusion (DLI), for prophylaxis (n=1) or treatment of recurrent ALL (n=5). Nine patients died of transplant-related mortality, with six deaths due to GVHD. The median follow-up of surviving patients was 11.6 months (range, 3.5-37.3 months). The 1-year relapse-free and overall survival rates were 29.8 and 39.6%, respectively. Of the 14 patients transplanted in relapse, five remained relapse free for longer than 6 months. Cumulative rates of progression and progression-free mortality at 3 years were 50.9 and 30.4%, respectively. These findings suggest the presence of a graft-versus-leukemia effect for ALL. RIST for ALL is worth considering for further evaluation.

Investigation of Solid D 2 for UCN Sources

Solid deuterium (sD2) will be used for the production of ultra-cold neutrons (UCN) in a new generation of UCN sources. Scattering cross sections of UCN in sD2 determine the source yield but until now have not been investigated. We report first results from transmission and scattering experiments with cold, very cold and ultra-cold neutrons on sD2 along with light transmission and Raman scattering studies showing the influence of the sD2 crystal properties.

Measured total cross sections of slow neutrons scattered by gaseous and liquid 2H(2)

The total scattering cross sections for slow neutrons with energies E in the range 300 neV to 3 meV for gaseous and liquid ortho-2H2 have been measured. The cross sections for 2H2 gas are found to be in excellent agreement with both the Hamermesh and Schwinger and the Young and Koppel models. For liquid 2H(2), we confirm the existing experimental data in the cold neutron range and the discrepancy with the gas models. We find a clear 1 / square root[E'] dependence at low energies for both states. A simple explanation for the liquid 2H2 cross section is offered.

Acute myelogenous leukemia in a donor after granulocyte colony-stimulating factor-primed peripheral blood stem cell harvest

This article describes the first case of acute myeloid leukemia (AML) in a healthy donor at 14 months after granulocyte colony-stimulating factor (G-CSF)-primed peripheral blood stem cell (PBSC) harvest. In September 2001, a healthy 61-year-old female was given G-CSF prior to PBSC harvest for her brother with multiple myeloma. In spite of successful engraftment, the recipient died from a disease relapse. In November 2002, the donor, admitted with high fever and leukocytosis with 98.5% blastoid cells, was diagnosed as having AML (M1). Her leukemia cells were positive for CD13, CD33, and G-CSF receptor without chromosomal abnormality and responded to G-CSF in vitro. During chemotherapy, she died of progressive pneumonia. If our case is truly the first, the incidence of leukemia in donors may not be higher than that of naturally occurring leukemia. However, efforts towards an international long-term study, or at least to report every case similar to ours, would be required to be conclusive.

Protective role of HSP27 against UVC-induced cell death in human cells

It is an intriguing problem whether heat shock proteins (HSPs) play a protective role in UVC-induced cell death in human cells, and the problem has not been solved. To search for the HSPs involved in UVC resistance, gene expression profiles using cDNA array were compared between UVC-sensitive human RSa cells and their UVC-resistant variant AP(r)-1 cells. The expression levels of heat shock protein 27 (HSP27) were lower in RSa cells than in AP(r)-1 cells. RSa cells transfected with sense HSP27 cDNA showed slightly lower sensitivity to UVC-induced cell death than the control cells transfected with a vector alone and much lower sensitivity than RSa cells transfected with the antisense HSP27 cDNA. Furthermore, the removal capacities of the two major types of UVC-damaged DNA (thymine dimers and (6-4)photoproducts) in the cells with the up-regulation of HSP27 were moderately elevated compared with those in the control cells, while those in the cells with down-regulation were remarkably suppressed. These results suggest that HSP27 is involved in the UVC-resistance of human cells, at least those tested, possibly via functioning in nucleotide excision repair.