Bone marrow-derived NGFR+ cells regulate arterial remodeling and those poor mobilizations in peripheral blood in acute coronary syndrome predicts plaque progression at the non-targeted lesion

Background

In our previous 5-year cohort study, we demonstrated that low gene expression of nerve growth factor receptor (NGFR) in peripheral leucocytes in acute coronary syndrome (ACS) predicted repetitive coronary interventions at the de novo lesions. An NGFR-positive cell has been demonstrated to reside in bone marrow (BM) stromal fraction and to be increased in peripheral blood mononuclear cell (MNCs) fraction in patients with ischemic heart disease.

Purpose

To investigate whether the BM-NGFR+ cell is associated with arterial remodeling and the relationship between the levels of peripheral NGFR+ cells after ACS and coronary plaque progression in an experimental and prospective clinical study.

Methods and results

In an experimental study, 8-week-old C57B6/J wild type male mice were subjected to irradiation with 9.6 Gy and transplantation with BM (BMT) isolated from GFP-transgenic NGFR wild type (WT) or knock-out (KO) mice at day 1. Four weeks after BMT, the right carotid artery was ligated for 4 weeks. Induced neointimal area was increased (p<0.05), where cells under apoptosis were decreased (p<0.05) in NGFR-KO-BMT group compared to WT-BMT group (n=4). NGFR+ cells were not detected in wild type sham-operated artery, whereas in the ligated artery in WT-BMT group NGFR+ cells assembled in the developed neointima and exclusively presented double positive with GFP, but absent in NGFR-KO-BMT group (p<0.05, n=4). In a clinical study, thirty patients with ACS who underwent primary percutaneous coronary intervention (PCI) were enrolled. The peripheral blood sample was collected on days 0, 3 and 7, and 9 months follow-up and the number of NGFR+MNCs were measured by flowcytometric analysis. The plaque volume at non-targeted coronary lesion (non-TL:>5 mm proximal or distal to the implanted stents) were quantitatively analysed using gray-scale intravascular ultrasound (IVUS) and Q-IVUS™ software at the acute phase and 9 months follow-up. The number of NGFR+MNCs in peripheral blood was 1.5-fold increased at day 3 (0.064±0.056%) compared to day 0 (0.042±0.030%) (p<0.05). The change in normalized total plaque volume (TAVN) at non-TL at 9 months was negatively correlated with the number of NGFR+MNCs at day 0 (r=−0.51), day 3 (r=−0.51) and 9 months (r=−0.59) after ACS (p<0.05). Multiple regression analysis showed that NGFR+MNCs at day 0 (β=−0.48, p=0.01) and CRP (β=−0.53, P<0.01) are independent factors associating with TAVN change at non-TL at 9 months, regardless of LDL-cholesterol control level. ROC analysis revealed that NGFR+MNCs <0.049 at day 0 predicted the increase of TAVN with AUC 0.78; sensitivity 0.82 and specificity 0.67.

Conclusions

Bone marrow-derived peripheral NGFR+ cells negatively regulate arterial remodeling through appropriate apoptosis of neointimal cells and the peripheral level of NGFR+ cells in ACS predicts plaque progression at the non-targeted lesion.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): KAKENHI

The surface composition of asteroid 162173 Ryugu from Hayabusa2 near-infrared spectroscopy

The near-Earth asteroid 162173 Ryugu, the target of the Hayabusa2 sample-return mission, is thought to be a primitive carbonaceous object. We report reflectance spectra of Ryugu's surface acquired with the Near-Infrared Spectrometer (NIRS3) on Hayabusa2, to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micrometers was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, which is consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.

Preparation of a novel antiserum to aromatase with high affinity and specificity: Its clinicopathological significance on breast cancer tissue

Aromatase inhibitors have been widely used for the endocrine treatment of estrogen-dependent breast cancer in postmenopausal patients. However, clinicopathological studies of aromatase have been limited due to unsatisfactory specificity and/or restricted availability of anti-aromatase antibodies. Here, we have generated a polyclonal antiserum with high affinity and specificity for human aromatase using a monoclonal antibody tagged immunoaffinity chromatography on an industrial production scale. Our preliminary immunohistochemical analysis of 221 invasive breast cancer cases indicated that 87.3% (193/221) had at least 5% aromatase positive cells. The histoscore for aromatase was inversely correlated with pT (p = 0.019), pN (p = 0.001), stage (p < 0.001), histologic grade (p = 0.003), lymphatic infiltration (p < 0.001), venous infiltration (p < 0.001), and Ki-67 index (p < 0.001). However, cancer aromatase expression was independent of estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor 2 statuses. This antiserum will be applicable to clinicopathological examination of aromatase in addition to ER and PgR for an appropriate use of aromatase inhibitor on the treatment of breast cancer. Further studies on the relationship between Aromatase inhibitors have been widely used for the endocrine treatment of estrogen-dependent breast cancer in postmenopausal patients. However, clinicopathological studies of aromatase have been limited due to unsatisfactory specificity and/or restricted availability of anti-aromatase antibodies. Here, we have generated a polyclonal antiserum with high affinity and specificity for human aromatase using a monoclonal antibody tagged immunoaffinity chromatography on an industrial production scale. Our preliminary immunohistochemical analysis of 221 invasive breast cancer cases indicated that 87.3% (193/221) had at least 5% aromatase positive cells. The histoscore for aromatase was inversely correlated with pT (p = 0.019), pN (p = 0.001), stage (p < 0.001), histologic grade (p = 0.003), lymphatic infiltration (p < 0.001), venous infiltration (p < 0.001), and Ki-67 index (p < 0.001). However, cancer aromatase expression was independent of estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor 2 statuses. This antiserum will be applicable to clinicopathological examination of aromatase in addition to ER and PgR for an appropriate use of aromatase inhibitor on the treatment of breast cancer. Further studies on the relationship between aromatase expression and aromatase inhibitors are warranted.

The role of the extracellular matrix in primary myelofibrosis

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm that arises from clonal proliferation of hematopoietic stem cells and leads to progressive bone marrow (BM) fibrosis. While cellular mutations involved in the development of PMF have been heavily investigated, noteworthy is the important role the extracellular matrix (ECM) plays in the progression of BM fibrosis. This review surveys ECM proteins contributors of PMF, and highlights how better understanding of the control of the ECM within the BM niche may lead to combined therapeutic options in PMF.

Restoration of MYC-repressed targets mediates the negative effects of GM-CSF on RUNX1-ETO leukemogenicity

GM-CSF signaling regulates hematopoiesis and immune responses. CSF2RA, the gene encoding the α subunit for GM-CSF, is significantly downregulated in t(8;21) (RUNX1-ETO or RE) leukemia patients, suggesting that it may serve as a tumor suppressor. We previously reported that GM-CSF signaling is inhibitory to RE leukemogenesis. Here we conducted gene expression profiling of primary RE hematopoietic stem/progenitor cells (HSPCs) treated with GM-CSF to elucidate the mechanisms mediating the negative effects of GM on RE leukemogenicity. We observed that GM treatment of RE HSPCs resulted in a unique gene expression profile that resembles primary human cells undergoing myelopoiesis, which was not observed in control HSPCs. Additionally we discovered that GM-CSF signaling attenuates MYC-associated gene signatures in RE HSPCs. In agreement with this, a functional screen of a subset of GM-CSF-responsive genes demonstrated that a MYC inhibitor, MXI1, reduced the leukemic potential of RE HSPCs and t(8;21) AML cells. Furthermore, MYC knockdown and treatment with the BET inhibitor JQ1 reduced the leukemic potential of t(8;21) cell lines. Altogether, we discovered a novel molecular mechanism mediating the GM-CSF-induced reduction in leukemic potential of RE cells, and our findings support MYC inhibition as an effective strategy for reducing the leukemogenicity of t(8;21) AML.

Analysis of individual differences in radiosensitivity using genome editing

Current standards for radiological protection of the public have been uniformly established. However, individual differences in radiosensitivity are suggested to exist in human populations, which could be caused by nucleotide variants of DNA repair genes. In order to verify if such genetic variants are responsible for individual differences in radiosensitivity, they could be introduced into cultured human cells for evaluation. This strategy would make it possible to analyse the effect of candidate nucleotide variants on individual radiosensitivity, independent of the diverse genetic background. However, efficient gene targeting in cultured human cells is difficult due to the low frequency of homologous recombination (HR) repair. The development of artificial nucleases has enabled efficient HR-mediated genome editing to be performed in cultured human cells. A novel genome editing strategy, 'transcription activator-like effector nuclease (TALEN)-mediated two-step single base pair editing', has been developed, and this was used to introduce a nucleotide variant associated with a chromosomal instability syndrome bi-allelically into cultured human cells to demonstrate that it is the causative mutation. It is proposed that this editing technique will be useful to investigate individual radiosensitivity.

Serum ferritin level is prognostic of patient outcome in extranodal NK/T cell lymphoma, nasal type

The objective of the current study was to assess the prognostic factors in patients with extranodal natural killer (NK)/T cell lymphoma, nasal type (ENKL). We retrospectively analyzed 35 patients who were diagnosed with ENKL between 1998 and 2011. The median patient age was 63 years, and the male/female ratio was 22:13; twenty patients had localized ENKL, and 26 had a good Eastern Cooperative Oncology Group performance status (score 0 or 1). B symptoms were present in 17 patients. Twenty-five patients presented with nasal or paranasal lesions, or both. With a median follow-up duration among patients still alive at their last follow-up of 47 months (range 8-93 months), the 3-year overall survival (OS) rate was 44.5 %. Multivariate analysis revealed that advanced disease stage (P = 0.002), the presence of extranasal disease (P = 0.013), and serum ferritin levels greater than 300 ng/ml (P < 0.001) were significant and independent (negative) prognostic factors. High serum ferritin levels were associated with the presence of B symptoms, elevated lactate dehydrogenase levels, and high soluble interleukin-2 receptor levels, but not with clinical stage. Patients with high ferritin levels had a remarkably low remission rate (23 %) and a short OS time (median: 4 months). Serum ferritin level at the time of diagnosis of ENKL was a useful prognostic factor.

The 3q27 and 18q21 translocations for follicular lymphoma and diffuse large B-cell lymphoma in the rituximab era

The 3q27 and 18q21 chromosomal translocations are major hallmarks in B-cell lymphoma. We aimed to determine the frequencies of these translocations in follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) and to evaluate their prognostic impact in the rituximab era. This study included 98 FL and 93 DLBCL patients whose abnormal karyotypes had been detected using G-banding. Patients uniformly underwent R-CHOP therapy : doxorubicin, cyclophosphamide, vincristine, prednisolone, and rituximab ; survivors were followed up for 29 months (median). The 3q27 and 18q21 translocations were detected in 14 and 77 FL patients and 14 and 22 DLBCL patients, respectively. Overall survival (OS) and progression-free survival (PFS) did not differ significantly between the groups with 3q27, 18q21, concurrent 3q27 and 18q21 translocations, and other chromosomal abnormalities for FL and DLBCL. There were no significant differences in OS and PFS between patients with 3q27 translocation-positive FL and those with 3q27 translocation-positive DLBCL or between the patients with 18q21 translocation-positive FL and those with 18q21 translocation-positive DLBCL. The presence of 3q27 and 18q21 translocations did not correlate with the clinical outcomes of FL or DLBCL patients following R-CHOP treatment.

Absolute monocyte count in follicular lymphoma patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone

Elevated absolute monocyte counts (AMCs) have been reported to indicate poor prognosis for patients with lymphoproliferative disease, including those with follicular lymphoma (FL) receiving various treatments. We evaluated the prognostic impact of AMC in 150 consecutive FL patients who received rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) therapy. Progression-free survival (PFS) did not differ significantly according to the AMC level. Univariate and multivariate analyses did not indicate a prognostic significance of AMC for PFS. Thus, the AMC is not a prognostic factor for FL patients treated with R-CHOP. However, immunochemotherapy might influence the prognostic impact of AMC.

[POEMS syndrome treated with lenalidomide plus high-dose dexamethasone as a pre-transplant induction therapy]

A 60-year-old male with POEMS syndrome received lenalidomide and high-dose dexamethasone combination therapy as an initial treatment, with no severe adverse events occurring during the treatment. Two cycles of the therapy led to significantly decreased serum VEGF level, and IgA-λ type M-protein was not detected by immunofixation electrophoresis. We next performed autologous stem cell transplantation, without severe complications such as engraftment syndrome. He improved enough to walk independently and now is being followed up without treatment. This case suggests that lenalidomide-dexamethasone therapy is highly effective and can be a good option for pre-transplant treatment for POEMS syndrome.

Effect of (6R)- and (6S)-tetrahydrobiopterin on L-3,4-dihydroxyphenylalanine (DOPA) formation in NRK fibroblasts transfected with human tyrosine hydroxylase type 2 cDNA

l-erythro-5,6,7,8-Tetrahydrobiopterin (BH(4)), which is the cofactor of aromatic amino acid hydroxylases, plays an important role in the biosyntheses of monoamine neurotransmitters. BH(4) exists as natural (6R)- and unnatural (6S)-isomers. In our previous reports, only (6R)-isomer significantly stimulated cofactor activity for tyrosine, tryptophan and phenylalanine hydroxylases (TH, TPH, PAH) in whole animals or in tissue slices. In this study we have compared the in situ cofactor activity on TH between natural (6R)- and unnatural (6S)-isomers in clonal cells. We have transfected human TH type 2 cDNA into the normal rat kidney (NRK) fibroblasts. These cells expressed TH protein, but had neither DOPA decarboxylase (DDC) nor BH(4). Thus, TH activity was observed only in the presence of exogenous BH(4). We compared the difference in in situ DOPA formation by TH activity in the presence of (6R)- or (6S)-BH(4) in the human TH-transfected cells. The effect of exogenous BH(4) was also compared between (6R)- and (6S)-isomers in rat pheochromocytoma PC12h cells, which contained approximately 100 ?M endogenous (6R)-BH(4). The rate of uptake of both BH(4) isomers into these cells increased in proportion to the pterin cofactor concentrations in the incubation medium up to 400 ?M but was nearly saturated at 1 mM BH(4). TH-transfected NRK fibroblasts formed DOPA only in the presence of exogenously added (6R)- or (6S)-BH(4) dose-dependently and released DOPA into the medium. At a saturating concentration of 1 mM, (6R)-BH(4) was approximately three times as active as (6S)-BH(4). In contrast, in PC12h cells which contained endogenous (6R)-BH(4) (approximately 100 ?M), exogenous (6R)-BH(4) activated DOPA formation maximally at 500 ?M about 10-fold, while (6S)-BH(4) activated it only slightly, about 2.5-fold. These results suggest that (6S)-isomer has lower cofactor activity with TH in the cells than (6R)-isomer. This TH transfected fibroblasts should be useful to assess cofactor activities of tetrahydropteridines in the cell.

Clinical features of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue

We newly diagnosed 131 patients with extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue lymphoma between 1998 and 2010. We retrospectively studied 124 patients for whom complete clinical data were available at presentation and who had minimally undergone tumour staging by physical examination, computed tomography (CT), bone marrow aspiration, and biopsy. A slight female predominance (men, 58; women, 66) was observed in the study population; the median age was 67 years. The primary locations at presentation were the stomach (38%), orbita (20%), lung (12%), intestinal tract (8%), thyroid gland (6%), others (14%), and unknown (2%). Seventy per cent of patients had localized disease. Of the 124 patients, 14 (11%) had lymph node involvement, and 5 (4%) had bone marrow involvement. Five (4%) patients had both lung and gastric involvement. The 5-year overall survival rate for the 124 patients was 96.1%. The overall vital prognosis was excellent. Moreover, gastro-intestinal fiberscopic examination is essential, especially in cases with lung involvement at presentation.

Histopathological safety evaluation of newly-developed MgO sealer

We aimed to evaluate the subcutaneous tissue reaction to a newly-developed MgO Sealer for root canals. We injected the experimental material and three existing control materials into the dorsal area of 43 male ddY mice. One week and 12 weeks after embedding, the tissue surrounding the embedding sites was removed and histopathological examination was performed. The results demonstrate that the basic histopathological reaction is the formation of fibrous capsules consisting of granulation tissue around the experimental and control embedded materials. Based on our results, we believe that the newly-developed MgO Sealer is as safe as the existing control materials and can be considered for dental use as a root canal sealer.

Comparative examination of subcutaneous tissue reaction to high molecular materials in medical use

Polypropylene (PP), Polyethylene (PE) and polytetrafluoroethylene (FE) are high molecular materials in medical use. They are also used as the negative control materials for ISO 10993-6 international standard biological evaluation of medical devices. We examined tissue reactions to these materials embedded subcutaneously in the dorsal area of male ddY mice. One week and 12 weeks after embedding, the tissue surrounding the embedding site was removed and then histopathological examination was performed. Our results demonstrate that the basic histopathological reaction is the formation of fibrous capsule consisting of granulation tissue around the embedded materials. Based on our results, we believe that the high molecular materials such as, PP, PE and FE, can be considered for medical use as a biomaterials within the body.

Histopathological examination of newly-developed adhesive silicone denture relining material

We aimed to evaluate the subcutaneous tissue reaction to a newly developed adhesive silicone denture relining material, SG, (Neo Dental Chemical Products Co., Ltd. Tokyo, Japan). We embedded the experimental material SG and another existing control material, Roeko Seal (RS), in the dorsal area of 22 male ddY mice. One week and 12 weeks after the embedding, the tissues surrounding the embedded materials were removed and a histopathological examination was performed. The results demonstrate that the basic histopathological aspects are the formation of granulation tissue and the change of the tissue to fibrous capsule over time. The results suggests that the newly-developed SG is safe as compared with the control RS, whose composition is similar.

[POEMS syndrome diagnosed by detection of M-protein on immunofixation and increased level of vascular endothelial growth factor]

A 48-year-old male with Castleman disease developed symptoms typical of POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal-protein and skin changes) but M-protein was not detected by immunoelec-trophoresis. He was diagnosed as having POEMS syndrome based on IgA-λ detected by immunofixation electrophoresis and an increased level (3,170 pg/ml) of vascular endothelial growth factor (VEGF). After diagnosis, the patient underwent autologous peripheral blood stem cell transplantation safely and remained relapse-free and in good condition for 15 months. This case suggests that immunofixation electrophoresis and detection of elevated serum VEGF level are useful methods for earlier diagnosis of POEMS syndrome.

PKCgamma in Vc and C1/C2 is involved in trigeminal neuropathic pain

The aim of the present study was to clarify the involvement of protein kinase Cγ (PKCγ) in the facial neuropathic pain following infraorbital nerve injury. We analyzed the change in PKCγ expression in the trigeminal spinal subnucleus caudalis (Vc) and upper cervical spinal cord (C1/C2) following chronic constriction injury of the infraorbital nerve (ION-CCI). We also studied ION-CCI-mediated mechanical nocifensive behavior in rats. The mechanical head-withdrawal threshold significantly decreased 1 to 14 days after ION-CCI compared with that before ION-CCI and in sham rats. The expression of PKCγ was significantly larger in the ipsilateral Vc compared with the contralateral side in ION-CCI rats 3, 7, and 14 days after ION-CCI. Intrathecal (i.t.) administration of the PKCγ inhibitor chelerythrine prevented an increase in the PKCγ expression in the ipsilateral Vc. Moreover, i.t. administration of chelerythrine annulled ION-CCI-mediated reduction in the head-withdrawal threshold. Taken together, these findings suggest that PKCγ expression in the Vc played an important role in the mechanism of orofacial static mechanical allodynia following trigeminal nerve injury.

BubR1 localizes to centrosomes and suppresses centrosome amplification via regulating Plk1 activity in interphase cells

BubR1 is a critical component of the mitotic checkpoint that delays the onset of anaphase until all chromosomes have established bipolar attachment to the microtubules. We previously reported that mutations of the BUB1B gene (encoding BubR1) caused premature chromatid separation (PCS) syndrome, a condition characterized by constitutional aneuploidy and a high risk of childhood cancer. We here report that the cells from PCS syndrome patients have loss of regulation of the centrosome duplication machinery, resulting in centrosome amplification and multipolar mitosis. PCS syndrome cells show increased activity of Polo-like kinase 1 (Plk1), whose knockdown suppresses centrosome amplification. BubR1 localizes to centrosomes, physically interacts with Plk1 and inhibits Plk1 phosphorylation and its kinase activity during interphase. These results unravel a crucial role of BubR1 in preventing centrosome reduplication through negative regulation of Plk1 in interphase cells.

[Tracheostenosis caused by blunt thoracic trauma]

Blunt thoracic trauma rarely implicate retropharyngeal hematoma obstructing trachea. 85-year-old woman being struck on her cheek and anterior chest, visited our emergency room. She was nearly suffocated following stridor and dyspnea. Tracheal intubation relieved her dyspnea Chest computed tomography (CT) showed retropharyngeal hematoma obstructing trachea. 5 days conservative management reduced the hematoma and tracheal tube was extubated through an uneventful course.

NBS1 prevents chromatid-type aberrations through ATM-dependent interactions with SMC1

Nijmegen breakage syndrome shares several common cellular features with ataxia telangiectasia, including chromosomal instability and aberrant S- and G2-phase checkpoint regulation. We show here that after irradiation, NBS1 interacts physically with both BRCA1 and SMC1, a component of the cohesin complex, and that their interactions are completely abolished in AT cells. It is noted that BRCA1 is required for the interaction of NBS1 with SMC1, whereas the reverse is not the case, since BRCA1 is able to bind to NBS1 in the absence of an NBS1/SMC1 interaction as observed in MRE11- or RAD50-deficient cells. This indicates that ATM and BRCA1 are upstream of the NBS1/SMC1 interaction. Furthermore, the interaction of NBS1 with SMC1 requires both conserved domains of NBS in the N-terminus and the C-terminus, since they are indispensable for binding of NBS1 to BRCA1 and to MRE11/ATM, respectively. The interaction of NBS1 with SMC1 and the resulting phosphorylation are compromised in the clones lacking either the N- or C-terminus of NBS1, and as a consequence, chromatid-type aberrations are enhanced after irradiation. Our results reveal that ATM plays a fundamental role in promoting the radiation-induced interaction of NBS1 with SMC1 in the presence of BRCA1, leading to the maintenance of chromosomal integrity.

Centrosome amplification induced by survivin suppression enhances both chromosome instability and radiosensitivity in glioma cells

Glioblastoma is characterised by invasive growth and a high degree of radioresistance. Survivin, a regulator of chromosome segregation, is highly expressed and known to induce radioresistance in human gliomas. In this study, we examined the effect of survivin suppression on radiosensitivity in malignant glioma cells, while focusing on centrosome aberration and chromosome instability (CIN). We suppressed survivin by small interfering RNA transfection, and examined the radiosensitivity using a clonogenic assay and a trypan blue exclusion assay in U251MG (p53 mutant) and D54MG (p53 wild type) cells. To assess the CIN status, we determined the number of centrosomes using an immunofluorescence analysis, and the centromeric copy number by fluorescence in situ hybridisation. As a result, the radiosensitisation differed regarding the p53 status as U251MG cells quickly developed extreme centrosome amplification (=CIN) and enhanced the radiosensitivity, while centrosome amplification and radiosensitivity increased more gradually in D54MG cells. TUNEL assay showed that survivin inhibition did not lead to apoptosis after irradiation. This cell death was accompanied by an increased degree of aneuploidy, suggesting mitotic cell death. Therefore, survivin inhibition may be an attractive therapeutic target to overcome the radioresistance while, in addition, proper attention to CIN (centrosome number) is considered important for improving radiosensitivity in human glioma.

First Report of Chrysanthemum stem necrosis virus on Chrysanthemums in Japan

The chrysanthemum (Dendranthema grandiflorum), whose planted area comprises more than 6,000 ha in Japan, is one of the most important ornamental cut flower crops. In August 2006, necrotic streaks on stems, chlorotic and necrotic spots and rings on leaves, and leaf distortions were observed on chrysanthemum cvs. Jimba and Seinotama, with a disease incidence of more than 70% (approximately 30,000 plants), which represents approximately 1,000 m² of greenhouses of one grower in Hiroshima Prefecture, western Japan. Symptoms were similar to those caused by Tomato spotted wilt virus (TSWV) (genus Tospovirus, family Bunyaviridae). Frankliniella occidentalis was the major thrips species observed on symptomatic plants, followed by F. intonsa. Tospovirus-like spherical particles that were 80 to 100 nm in diameter were found in the infected leaves. After mechanical inoculation, a single lesion isolate reproduced the original symptoms observed in nature on healthy chrysanthemum plants (cv. Jimba). As determined by mechanical inoculation, host range and symptomatology of the isolate were similar to those described previously for Chrysanthemum stem necrosis virus (CSNV), including necrotic spots on Petunia hybrida (1). The isolate caused stunting, severe necrotic lesions on stems, necrotic spots, rings, and vein necrosis on systemically infected leaves of Lycopersicon esculentum (cv. House-momotaro). This virus reacted strongly with CSNV antiserum (DSMZ, Braunschweig, Germany) by indirect dot immuno-binding assay, and cross-reacted weakly with a monoclonal antibody to N protein of TSWV (3) using double-antibody sandwich-ELISA. Reverse transcription (RT)-PCR was conducted to verify virus infection. No amplification was observed from extracts of symptomatic plants (n = 10) by multiplex RT-PCR using TSWV and Impatiens necrotic spot virus specific primer sets (4), indicating that the diseased chrysanthemums were not doubly infected with these viruses. However, a DNA fragment of approximately 450 bp was amplified in samples by RT-PCR using tospovirus universal primers, BR60/65 (2). The nucleotide sequence of the amplified fragment had 98.1% identity with the corresponding region of the CSNV nucleocapsid protein gene (GenBank Accession No. AF067068). The above results indicate that the virus associated with a stem necrosis disease of chrysanthemums in Hiroshima is an isolate of CSNV. To our knowledge, this is the first report of CSNV in Japan. References: (1) I. C. Bezerra et al. Phytopathology 89:823, 1999. (2) M. Eiras et al. Fitopatol. Bras. 26:170, 2001. (3) S. Tsuda et al. Ann. Phytopathol. Soc. Jpn. 60:216, 1994. (4) H. Uga and S. Tsuda. Phytopathology 95:166, 2005.

Homologous recombination repair is regulated by domains at the N- and C-terminus of NBS1 and is dissociated with ATM functions

The proteins responsible for radiation sensitive disorders, NBS1, kinase ataxia-telangiectasia-(A-T)-mutated (ATM) and MRE11, interact through the C-terminus of NBS1 in response to the generation of DNA double-strand breaks (DSBs) and are all implicated in checkpoint regulation and DSB repair, such as homologous recombination (HR). We measured the ability of several NBS1 mutant clones and A-T cells to regulate HR repair using the DR-GFP or SCneo systems. ATM deficiency did not reduce the HR repair frequency of an induced DSB, and it was confirmed by findings that HR frequencies are only slightly affected by deletion of ATM-binding site at the extreme C-terminus of NBS1. In contrast, The HR-regulating ability is dramatically reduced by deletion of the MRE11-binding domain at the C-terminus of NBS1 and markedly inhibited by mutations in the FHA/BRCT domains at the N-terminus. This impaired capability in HR is consistent with a failure to observe MRE11 foci formation. Furthermore, normal HR using sister chromatid was completely inhibited by the absence of FHA/BRCT domains. These results suggested that the N- and C-terminal domains of NBS1 are the major regulatory domains for HR pathways, very likely through the recruitment and retention of the MRE11 nuclease to DSB sites in an ATM-independent fashion.

Orotate phosphoribosyltransferase levels measured by a newly established enzyme-linked immunosorbent assay in gastric carcinoma

A number of enzymes have been shown to be involved in the process of activation and/or degradation of 5-fluorouracil (5-FU), and are potential candidates for predicting chemosensitivity to 5-FU. Among these, orotate phosphoribosyltransferase (OPRT EC 2.4.2.10) is a key enzyme related to the first-step activation process of 5-FU and has been shown to be an important enzyme that helps to predict sensitivity to 5-FU and its related derivatives. We developed a new enzyme-linked immunosorbent assay (ELISA) to accurately assess intratumoral activity of OPRT. A new sandwich ELISA was established using anti-OPRT polyclonal antibodies obtained from the rabbit immunized with the recombinant human peptides of the OPRT molecule. OPRT levels were measured in eight human cancer xenografts and in 75 gastric cancer tissues using both a newly established ELISA and a conventional enzyme assay, using radiolabeled 5-FU as a substrate. There was a significant correlation between OPRT levels measured by this ELISA and OPRT enzyme activity the in eight human cancer xenografts (r2 = 0.782) and gastric carcinoma tissue (r2 = 0.617). The ELISA system for OPRT requires a minimal amount of carcinoma tissue, making it an easy-to-use assay system to predict sensitivity to 5-FU and its derivatives in gastric carcinoma. There was a significant correlation between tumor growth inhibition rates against the oral administration of oral-uracil/tegafur (UFT) and OPRT enzyme activity in the human cancer xenografts (r2 = 0.574). These results suggest that this newly developed sandwich ELISA system for the quantification of OPRT levels is technically simple, feasible and a useful tool to predict sensitivity to fluoropyrimidine-based anticancer chemotherapy in patients with gastric carcinoma and other cancers.

New rapid detection test with a combination of polymerase chain reaction and immunochromatographic assay for Mycobacterium tuberculosis complex

Recently, we had developed a polymerase chain reaction (PCR)-immunochromatographic assay (ICA) method for Mycobacterium tuberculosis and examined its clinical utility among 138 sputa of patients under suspicion of pulmonary tuberculosis. According to the results of fluorochrome staining of acid-fast bacillus, which were confirmed by Ziehl-Neelsen staining, these were 83 specimens (-), 7 specimens (+/-), 30 specimens (1+), 8 specimens (2+), and 10 specimens (3+). These specimens included 4 groups: group 1, 41 specimens of smear (+/-) approximately (3+) with culture-positive M. tuberculosis; group 2, 11 specimens of smear (-) with culture-positive M. tuberculosis; group 3, 12 specimens of smear (+/-) approximately (1+) with culture-positive nontuberculosis mycobacterium (NTM); and group 4, 9 specimens of smear (-) with culture-positive NTM. The positive results of PCR-ICA test and Amplicor M. tuberculosis (Amplicor MTB) test for M. tuberculosis are as follows: group 1, 40 positive by PCR-ICA and 39 positive by Amplicor MTB from 41 specimens; group 2, 1 positive by PCR-ICA and 5 positive by Amplicor MTB from 11 specimens; group 3, 0 positive by both tests from 12 specimens; and group 4, 0 positive by both tests from 9 specimens. None of NTM-positive specimens from groups 3 and 4 reacted on the PCR-ICA test for M. tuberculosis.

Nijmegen breakage syndrome and functions of the responsible protein, NBS1

Nijmegen breakage syndrome (NBS) is a rare recessive genetic disorder, characterized by bird-like facial appearance, early growth retardation, congenital microcephaly, immunodeficiency and high frequency of malignancies. NBS belongs to the so-called chromosome instability syndromes; in fact, NBS cells display spontaneous chromosomal aberrations and are hypersensitive to DNA double-strand break-inducing agents, such as ionizing radiations. NBS1, the gene underlying the disease, is located on human chromosome 8q21. The disease appears to be prevalent in the Eastern and Central European population where more than 90% of patients are homozygous for the founder mutation 657del5 leading to a truncated variant of the protein. NBS1 forms a multimeric complex with MRE11/RAD50 nuclease at the C-terminus and retains or recruits them at the vicinity of sites of DNA damage by direct binding to histone H2AX, which is phosphorylated by PI3-kinase family, such as ATM, in response to DNA damage. Thereafter, the NBS1-complex proceeds to rejoin double-strand breaks predominantly by homologous recombination repair in vertebrates. NBS cells also show to be defective in the activation of intra-S phase checkpoint. We review here some cellular and molecular aspects of NBS, which might contribute to the clinical symptoms of the disease.