Observation of the Exotic 0_{2}^{+} Cluster State in ^{8}He

We report here the first observation of the 0_{2}^{+} state of ^{8}He, which has been predicted to feature the condensatelike α+^{2}n+^{2}n cluster structure. We show that this state is characterized by a spin parity of 0^{+}, a large isoscalar monopole transition strength, and the emission of a strongly correlated neutron pair, in line with theoretical predictions. Our finding is further supported by the state-of-the-art microscopic α+4n model calculations. The present results may lead to new insights into clustering in neutron-rich nuclear systems and the pair correlation and condensation in quantum many-body systems under strong interactions.

First observation of 28O

Subjecting a physical system to extreme conditions is one of the means often used to obtain a better understanding and deeper insight into its organization and structure. In the case of the atomic nucleus, one such approach is to investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich isotopes exhibit the most asymmetric N/Z ratios and those lying beyond the limits of binding, which undergo spontaneous neutron emission and exist only as very short-lived resonances (about 10-21 s), provide the most stringent tests of modern nuclear-structure theories. Here we report on the first observation of 28O and 27O through their decay into 24O and four and three neutrons, respectively. The 28O nucleus is of particular interest as, with the Z = 8 and N = 20 magic numbers1,2, it is expected in the standard shell-model picture of nuclear structure to be one of a relatively small number of so-called 'doubly magic' nuclei. Both 27O and 28O were found to exist as narrow, low-lying resonances and their decay energies are compared here to the results of sophisticated theoretical modelling, including a large-scale shell-model calculation and a newly developed statistical approach. In both cases, the underlying nuclear interactions were derived from effective field theories of quantum chromodynamics. Finally, it is shown that the cross-section for the production of 28O from a 29F beam is consistent with it not exhibiting a closed N = 20 shell structure.

STMO-4 INITIAL EXPERIENCE WITH BRAIN TUMOR SURGERY USING STEALTH AUTOGUIDE

Tissue sampling of brain tumors is generally performed by biopsy with large or small craniotomy and stereotaxic brain biopsy. Recently, Stealth Autoguide, a robotic system for stereotactic deep electrode implantation and brain tumor biopsy in epilepsy, has become available. We report the initial experience of brain tumor surgery using stealth Autoguide in our hospital.Case: A man in his 70s. Left paralysis occurred during chemotherapy for esophageal cancer. Magnetic resonance imaging (MRI) revealed a ring-enhanced lesion from the right basal ganglia to the coronal radiatum. Because he was under steroid administration, he was diagnosed with metastatic brain tumor, malignant lymphoma, malignant glioma, or demyelinating disease. Since paralysis was progressing and MRS was suspected to be a malignant tumor, a stereotactic biopsy using a stealth autoguide was performed. Biopsies were performed with skin incisions of 1 cm or less from two locations that were automatically positioned based on the preoperative planning, and a sufficient amount of tissue was collected from the lesions. No complications such as bleeding were observed. Since the histological diagnosis was glioblastoma, chemotherapy with temozolomide and radiotherapy were promptly started.Brain tumor biopsy using stealth Autoguide allows accurate tissue sampling in a short period of time, and is a very useful tool for brain tumor diagnosis in the future.

STMO-12 Efforts for safe malignant brain tumor surgery at our hospital

Although maximal safe resection is the current standard for glioblastoma surgery, its safety and removal rate conflict with each other. Electrophysiological monitoring, such as motor evoked potential monitoring and awake craniotomy, can be utilized as safety measures; not all facilities can perform them. Herein, we present a representative case report on our efforts for a safe malignant brain tumor surgery.

Case: A 77-year-old woman with glioblastoma in the premotor cortex presented with seizure of the upper left lower limb. Her pyramidal tract ran from the medial bottom to the posterior of the tumor. We performed excision from the site using the lowest gamma entropy. We then removed all parts of the tumor, with the exception of the pyramidal tract infiltration, and no paralysis was observed. She was definitively diagnosed with glioblastoma and is currently on maintenance chemotherapy.

As a preoperative examination, we performed cerebrovascular angiography. We then performed various other tests to ascertain the patient’s condition. Considering lesions that affect language, Wada tests were performed regardless of laterality. For all patients with epilepsy onset, preoperative 256-channel electroencephalogram measurement and intraoperative the gamma entropy analysis were performed to confirm epileptogenicity. Considering lesions that affect eloquence, subdural electrodes were placed and brain function mapping was performed the next day. Based on the results, the safest cortical incision site and excision range were determined, and excision was performed on the following day.

Of the 14 operated glioblastoma cases after November 2018, more than 85% of the contrast-enhanced lesions were completely removed in 7 cases, partially removed in 5 cases, and underwent biopsy in 2 cases. Postoperative Karnofsky performance status scores remained unchanged in 11 cases, improved in 1 case, and deteriorated in 2 cases.

Our efforts have resulted in safe and sufficient removal of malignant brain tumors during surgery.

Halo Structure of the Neutron-Dripline Nucleus ^{19}B

The heaviest bound isotope of boron ^{19}B has been investigated using exclusive measurements of its Coulomb dissociation, into ^{17}B and two neutrons, in collisions with Pb at 220  MeV/nucleon. Enhanced electric dipole (E1) strength is observed just above the two-neutron decay threshold with an integrated E1 strength of B(E1)=1.64±0.06(stat)±0.12(sys)  e^{2} fm^{2} for relative energies below 6 MeV. This feature, known as a soft E1 excitation, provides the first firm evidence that ^{19}B has a prominent two-neutron halo. Three-body calculations that reproduce the energy spectrum indicate that the valence neutrons have a significant s-wave configuration and exhibit a dineutronlike correlation.

Extending the Southern Shore of the Island of Inversion to ^{28}F

Detailed spectroscopy of the neutron-unbound nucleus ^{28}F has been performed for the first time following proton/neutron removal from ^{29}Ne/^{29}F beams at energies around 230  MeV/nucleon. The invariant-mass spectra were reconstructed for both the ^{27}F^{(*)}+n and ^{26}F^{(*)}+2n coincidences and revealed a series of well-defined resonances. A near-threshold state was observed in both reactions and is identified as the ^{28}F ground state, with S_{n}(^{28}F)=-199(6)  keV, while analysis of the 2n decay channel allowed a considerably improved S_{n}(^{27}F)=1620(60)  keV to be deduced. Comparison with shell-model predictions and eikonal-model reaction calculations have allowed spin-parity assignments to be proposed for some of the lower-lying levels of ^{28}F. Importantly, in the case of the ground state, the reconstructed ^{27}F+n momentum distribution following neutron removal from ^{29}F indicates that it arises mainly from the 1p_{3/2} neutron intruder configuration. This demonstrates that the island of inversion around N=20 includes ^{28}F, and most probably ^{29}F, and suggests that ^{28}O is not doubly magic.

COT-18 TWO CASES OF GLIOBLASTOMA WITH ASYMPTOMATIC PULMONARY ARTERY EMBOLISM AND DEEP VEIN THROMBOSIS FROM ADMISSION TO HOSPITAL

Patients with malignant tumors are susceptible to concurrent venous thromboembolism. We report two cases of glioblastomas that showed asymptomatic pulmonary embolism and deep vein thrombosis on admission. The first case was a 77-year-old male. He was referred to our clinic for a tumor found in the left temporal lobe on computed tomography scan performed when he suffered pneumonia. On admission,he had a Karnofsky performance status (KPS) score of 50 and an elevated D-dimer level (16.46 μg/ml). Pulmonary embolism and deep vein thrombosis were noted on detailed examination. Direct oral anticoagulant (DOAC) therapy resulted in the disappearance of pulmonary embolism. On biopsy,the tumor was diagnosed as glioblastoma. The patient underwent radiation therapy in combination with chemotherapy. The second case was a 71-year-old female. She developed a disorder of consciousness and was admitted to a clinic. Brain magnetic resonance imaging (MRI) revealed a high T2 signal area in the left temporal lobe. The patient was initially diagnosed with encephalitis. Though the consciousness disorder improved quickly,she was referred to our clinic after a hyperintense area was observed on MRI. On admission,she had a KPS score of 100,and an elevated D-dimer level (7.59μg/ml),revealing pulmonary embolism and deep vein thrombosis. She was started on a DOAC and underwent surgical removal of the tumor via craniotomy. She was diagnosed with glioblastoma and underwent radiation therapy in combination with chemotherapy. Approximately 20% of the patients with glioblastomas suffer concurrent symptomatic venous thromboembolism. The incidence of venous thromboembolism is further elevated in patients with a poor KPS score or elderly people. Many patients with glioblastomas suffer asymptomatic venous thromboembolism. In this report,asymptomatic venous thromboembolism was noted in patients with a good KPS score. In glioblastoma patients,it is necessary to test for venous thromboembolism by measuring D-dimer levels before surgery.

First Observation of ^{20}B and ^{21}B

The most neutron-rich boron isotopes ^{20}B and ^{21}B have been observed for the first time following proton removal from ^{22}N and ^{22}C at energies around 230  MeV/nucleon. Both nuclei were found to exist as resonances which were detected through their decay into ^{19}B and one or two neutrons. Two-proton removal from ^{22}N populated a prominent resonancelike structure in ^{20}B at around 2.5 MeV above the one-neutron decay threshold, which is interpreted as arising from the closely spaced 1^{-},2^{-} ground-state doublet predicted by the shell model. In the case of proton removal from ^{22}C, the ^{19}B plus one- and two-neutron channels were consistent with the population of a resonance in ^{21}B 2.47±0.19  MeV above the two-neutron decay threshold, which is found to exhibit direct two-neutron decay. The ground-state mass excesses determined for ^{20,21}B are found to be in agreement with mass surface extrapolations derived within the latest atomic-mass evaluations.

Nucleus ^{26}O: A Barely Unbound System beyond the Drip Line

The unbound nucleus ^{26}O has been investigated using invariant-mass spectroscopy following one-proton removal reaction from a ^{27}F beam at 201  MeV/nucleon. The decay products, ^{24}O and two neutrons, were detected in coincidence using the newly commissioned SAMURAI spectrometer at the RIKEN Radioactive Isotope Beam Factory. The ^{26}O ground-state resonance was found to lie only 18±3(stat)±4(syst)  keV above threshold. In addition, a higher lying level, which is most likely the first 2^{+} state, was observed for the first time at 1.28_{-0.08}^{+0.11}  MeV above threshold. Comparison with theoretical predictions suggests that three-nucleon forces, pf-shell intruder configurations, and the continuum are key elements to understanding the structure of the most neutron-rich oxygen isotopes beyond the drip line.

Observation of a p-wave one-neutron halo configuration in (37)Mg

Cross sections of 1n-removal reactions from the neutron-rich nucleus (37)Mg on C and Pb targets and the parallel momentum distributions of the (37)Mg residues from the C target have been measured at 240  MeV/nucleon. A combined analysis of these distinct nuclear- and Coulomb-dominated reaction data shows that the (37)Mg ground state has a small 1n separation energy of 0.22(-0.09)(+0.12)  MeV and an appreciable p-wave neutron single-particle strength. These results confirm that (37)Mg lies near the edge of the "island of inversion" and has a sizable p-wave neutron halo component, the heaviest such system identified to date.

Deformation-driven p-wave halos at the drip line: 31Ne

The halo structure of 31Ne is studied using 1n-removal reactions on C and Pb targets at 230  MeV/nucleon. A combined analysis of the cross sections of these nuclear and Coulomb dominated reactions that feed directly the 30Ne ground-state reveals 31Ne to have a small neutron separation energy, 0.15(-0.10)(+0.16)  MeV, and spin-parity 3/2-. Consistency of the data with reaction and large-scale shell-model calculations identifies 31Ne as deformed and having a significant p-wave halo component, suggesting that halos are more frequent occurrences at the neutron drip line.

The Activities of the Muscles around the Ankle Joint during Foot-gripping are Affected by the Angle of the Ankle

[Purpose] The purpose of this study was to determine the activities of the muscles around the ankle joint during foot gripping. [Subjects] The subjects of this study were 17 healthy females. [Methods] We measured the maximum voluntary contraction (MVC) activities of the soleus muscle, the medial head of the gastrocnemius muscle, and the tibialis anterior muscle, and calculated %IEMG during foot gripping in 3 different ankle joint positions: 10° of plantar flexion, 0°, and 10° of dorsiflexion. [Results] The maximal force of foot gripping achived by the crural muscles in any ankle position was 30–50% IMEG of the MVC. Repeated analysis of variance showed that the %IEMG was significantly lower in 10°of dorsiflexion than in the other 2 positions for all muscles. [Conclusion] These results suggested that the crural muscles help the ankle joint by co-contracting during foot gripping.

N = 16 spherical shell closure in 24O

The unbound excited states of the neutron drip-line isotope 24O have been investigated via the 24O(p,p')23O + n reaction in inverse kinematics at a beam energy of 62  MeV/nucleon. The decay energy spectrum of 24O* was reconstructed from the momenta of 23O and the neutron. The spin parity of the first excited state, observed at E(x) = 4.65±0.14  MeV, was determined to be J(π) = 2+ from the angular distribution of the cross section. Higher-lying states were also observed. The quadrupole transition parameter β2 of the 2(1)+ state was deduced, for the first time, to be 0.15±0.04. The relatively high excitation energy and small β2 value are indicative of the N = 16 shell closure in 24O.

Hindered proton collectivity in 16(28)S12: possible magic number at Z=16

The reduced transition probability B(E2;0(gs)(+)→2(1)(+)) for (28)S was obtained experimentally using Coulomb excitation at 53 MeV/nucleon. The resultant B(E2) value 181(31) e(2)fm(4) is smaller than the expectation based on empirical B(E2) systematics. The double ratio |M(n)/M(p)|/(N/Z) of the 0(gs)(+)→2(1)(+) transition in (28)S was determined to be 1.9(2) by evaluating the M(n) value from the known B(E2) value of the mirror nucleus (28)Mg, showing the hindrance of proton collectivity relative to that of neutrons. These results indicate the emergence of the magic number Z=16 in the |T(z)|=2 nucleus (28)S.

Halo structure of the island of inversion nucleus 31Ne

The cross sections for single-neutron removal from the very neutron-rich nucleus 31Ne on Pb and C targets have been measured at 230 MeV/nucleon using the RIBF facility at RIKEN. The deduced large Coulomb breakup cross section of 540(70) mb is indicative of a soft E1 excitation. Comparison with direct-breakup model calculations suggests that the valence neutron of 31Ne occupies a low-l orbital (most probably 2p(3/2)) with a small separation energy (S(n) approximately < 0.8 MeV), instead of being predominantly in the 1f(7/2) orbital as expected from the conventional shell ordering. These findings suggest that 31Ne is the heaviest halo system known.

[Open stent-grafting for the distal arch aneurysm using a new delivery system]

Recently, open stent-grafting has been employed for distal arch aneurysm. However, several complications have been reported. We have used a new delivery system (CLATE) in 8 patients who underwent open stent-grafting. The advantage of CLATE is that it is flexible, and can freely change its shape. Using this delivery system, stent graft is hard to dislocate, and can be delivered at the target site accurately. Therefore, CLATE is considerd to be able to prevent aortic wall injury, peripheral embolic complication and paraplegia.

Spectroscopy of 32Ne and the "Island of Inversion"

We report on the first spectroscopic study of the N=22 nucleus 32Ne at the newly completed RIKEN Radioactive Ion Beam Factory. A single gamma-ray line with an energy of 722(9) keV was observed in both inelastic scattering of a 226 MeV/u 32Ne beam on a carbon target and proton removal from 33Na at 245 MeV/u. This transition is assigned to the deexcitation of the first Jpi=2+ state in 32Ne to the 0+ ground state. Interpreted through comparison with state-of-the-art shell-model calculations, the low excitation energy demonstrates that the "island of inversion" extends to at least N=22 for the Ne isotopes.

Randomized phase II/III study of docetaxel/S-1 (DS-1) versus CDDP/5FU (FUP) in advanced or recurrent gastric cancer: Updated phase II results

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Background: Our previous single arm phase II trial demonstrated that the combination of DS-1 was one of the most powerful candidates to become a standard regimen for metastatic gastric cancer (K. Yoshida, et al: Clin Cancer Res 2006). This trial evaluated DS-1 and FUP in advanced or recurrent gastric cancer, and the primary objective of the phase II part was to evaluate activity and safety of the 2 regimens. Methods: Patients with advanced or recurrent gastric cancer, who had not received any chemotherapy except one regimen (not including taxanes), were eligible for this trial. Patients were randomized to either: DS-1, intravenous administration of 40 mg/m2 docetaxel on Day1 and oral administration of 80–120 mg/m2/day S-1 on Days 1 to 14 every 3 weeks, or FUP, intravenous continuous administration of 800 mg/m2/day 5-FU on Day 1 to 5 and intravenous administration of 80 mg/m2/day CDDP on Day 2 every 4 weeks. Results: Between June 2005 and August 2008, forty-nine of 54 patients (ECOG PS 0–2) were randomized to DS-1 (n=24) or FUP (n=25). Response rates (CR+PR) assessed by RECIST were 88.3% (CI;62.6–95.3) vs 52.0% (CI; 31.3–72.2, P=0.032), median times to treatment failure (TTF) were 122 days (CI; 75.2–168.8) vs 85 days (CI;67.9–102.1, P=0.003), median progression free survivals (PFS) were 198 days (CI;117.8–278.4) vs 105 days (CI;90.3–119.7, P=0.066). Median overall survival times (MSTs) were 369 days (CI; 359.6–378.4) vs 371 days (CI; 297.2- 444.8, P=0.281), but as of today, 14 pts (8 in DS-1 and 6 in FUP) are still alive. Grade 3/4 adverse events assessed by CTCAE v3.0 occurring in ≥20% patients, were neutropenia (58.3% vs 28.0%), nausea (4.2% vs 20.0%), leucopenia (33.0% vs 4.0%), fatigue (0% vs 20.0%) and anorexia (8.3% vs 32.0%). All treatment-related adverse events were resolved and no toxic death was reported. Conclusions: DS-1 significantly improved the RR and TTF in advanced or recurrent gastric cancer patients. To clarify the survival benefit, a phase III continuation of the study is in preparation.

No significant financial relationships to disclose.

Factors influencing 3D-MRI diagnosis in preoperative breast cancer patients

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Background: We presented 3D-MRI will be the useful breast imaging tool in diagnosing intraductal spread and tumor size in breast cancer patients. (ASCO 2008).To do breast conserving surgery, careful management was needed in cases with widely ductal spreading and multifocal lesion. This study was to evaluate factors influencing false negative diagnosis and multifocal types of 3D-MRI, retrospectively. Methods: From July 2000, pre-operative 3D-MRI was underwent 488 cases and images were obtained 479 cases (98%). These patients could be divided into three groups according to 3D-MRI images: pattern 1) localized type (273 cases), 2) widely enhanced type (106 cases) and 3) multi-focal type (100 cases). From April 2005, resected specimen was serially step cut and total specimens were microscopically evaluated. Tumor size in 3D-MRI was 1cm over smaller than resected specimens were defined false negative cases. Investigated factors influencing 3D-MRI were age, patterns of 3D-MRI images, presence of pre-operative chemotherapy, histological type, histological grade, microscopical invasive tumor size (mm) and presence of ductal spreading. Results: The rate of histological confirmed intraductal spread were seen in 58% (158/273cases), 89% (94/106 cases) of patients with 3D-MRI pattern 1) and 2), respectively. Tumor size was correlated between MRI and specimens, significantly (n = 162, r = 06706, p < 0.001). Factors influencing false negative diagnosis of 3D-MRI were presence of pre-operative chemotherapy (p < 0.05), presence of ductal spreading (p < 0.001) and patterns of 3D-MRI images (p < 0.05). In the cases with multi-focal 3D- images, there were only 11(11/41, 26%) cases with true multifocal lesions by total specimens examination. Selection for breast conserving surgery and margin width were based by 3D-MRI images. The proportion of breast-conserved surgery were obtained 90% (437/488 cases) and local failure seen only 6 cases (local failure rate 1.4%) in 3D-MRI guided surgery. (median follow up 52 months). Conclusions: These results suggest that MRI will be the useful breast imaging tool, but caution will be needed in cases with pre-operative systemic therapy, cases expected intraductal spread by imaging tools and cases with multi-focal 3D- images.

No significant financial relationships to disclose.

Caspases: evolutionary aspects of their functions in vertebrates

Caspases (cysteine-dependent aspartyl-specific protease) belong to a family of cysteine proteases that mediate proteolytic events indispensable for biological phenomena such as cell death and inflammation. The first caspase was identified as an executioner of apoptotic cell death in the worm Caenorhabditis elegans. Additionally, a large number of caspases have been identified in various animals from sponges to vertebrates. Caspases are thought to play a pivotal role in apoptosis as an evolutionarily conserved function; however, the number of caspases that can be identified is distinct for each species. This indicates that species-specific functions or diversification of physiological roles has been cultivated through caspase evolution. Furthermore, recent studies suggest that caspases are also involved in inflammation and cellular differentiation in mammals. This review highlights vertebrate caspases in their universal and divergent functions and provides insight into the physiological roles of these molecules in animals.

Decay pattern of pygmy states observed in neutron-rich 26Ne

Coulomb excitation of the exotic neutron-rich nucleus (26)Ne on a (208)Pb target was measured at 58 MeV/u in order to search for low-lying E1 strength above the neutron emission threshold. This radioactive beam experiment was carried out at the RIKEN Accelerator Research Facility. Using the invariant mass method in the 25Ne+n channel, we observe a sizable amount of E1 strength between 6 and 10 MeV excitation energy. By performing a multipole decomposition of the differential cross section, a reduced dipole transition probability of B(E1)=0.49+/-0.16e(2) fm(2) is deduced, corresponding to 4.9+/-1.6% of the Thomas-Reiche-Kuhn sum rule. For the first time, the decay pattern of low-lying strength in a neutron-rich nucleus is measured. The extracted decay pattern is not consistent with several mean-field theory descriptions of the pygmy states.

The cell death machinery controlled by Bax and Bcl-XL is evolutionarily conserved in Ciona intestinalis

Bax and Bcl-XL are key regulators of apoptosis in mammals. Here we report the functional characterization of two Bcl-2 homologues, ciBax and ciBcl-XL, in a basal invertebrate-chordate ascidian Ciona intestinalis. CiBax is a Ciona homologue of the BH1-3 pro-apoptotic protein Bax, whereas ciBcl-XL is a Bcl-XL-like anti-apoptotic protein. Molecular modeling analysis showed that ciBax and ciBcl-XL share both sequence and structural similarities to human Bax and Bcl-XL, respectively. Like their human counterparts, ciBax could form a homodimer or oligomers as well as heterodimerize with ciBcl-XL, and overexpression of ciBax caused apoptosis that could be attenuated by ciBcl-XL. Mutagenesis studies showed that the BH3 domain of ciBax is critical for its cell death-inducing function and also for its interaction with ciBcl-XL. In Ciona embryos, ectopic expression of ciBax but not its BH3 deletion mutant resulted in cell dissociation and apoptosis after late gastrula stage of embryonic development. Moreover, not only wild type ciBcl-XL but also a mutant ciBcl-XL(F101V), which is unable to interact with ciBax, could block cell dissociation and developmental deficit in Ciona embryos induced by overexpression of ciBax. Taken together, these findings suggest that functional homologues of both the BH1-3 death effector Bax and the pro-survival Bcl-XL exist in sea squirt Ciona intestinalis, and they control the cell death machinery independent of their heterodimerization.

Spectroscopic study of neutron shell closures via nucleon transfer in the near-dripline nucleus 23O

Neutron single particle energies have been measured in 23O using the 22O(d,p)23O*-->22O+n process. The energies of the resonant states have been deduced to be 4.00(2) MeV and 5.30(4) MeV. The first excited state can be assigned to the nu d3/2 single particle state from a comparison with shell model calculations. The measured 4.0 MeV energy difference between the nu s1/2 and nu d3/2 states gives the size of the N=16 shell gap which is in agreement with the recent USD05 ("universal" sd from 2005) shell model calculation, and is large enough to explain the unbound nature of the oxygen isotopes heavier than A=24. The resonance detected at 5.3 MeV can be assigned to a state out of the sd shell model space. Its energy corresponds to a approximately 1.3 MeV sized N=20 shell gap, therefore, the N=20 shell closure disappears at Z=8 in agreement with Monte Carlo shell model calculations using SDPF-M interaction.

Relationship between the growth pattern of nasopharyngeal cancer and the cervical lymph nodes based on MRI findings: can the cervical radiation field be reduced in patients with nasopharyngeal cancer?

To identify patients with nasopharyngeal cancer in whom the cervical radiation field can be reduced, we classified the growth patterns of nasopharyngeal cancer based on MRI findings into 4 types and performed an evaluation. Based on MRI findings, we classified the growth patterns of primary cancer in 94 patients with nasopharyngeal cancer into Type 1 (superficial type), Type 2 (lateral invasive type), Type 3 (upward invasive type), and Type 4 (anterior extension type), and further classified Type 2, based upon nasopharyngoscopic findings, into Type 2a (unilateral invasive type) and Type 2b (bilateral invasive type). The cervical lymph node metastasis areas were evaluated according to these types. Type 2 showed a significantly higher incidence of cervical lymph node metastasis only on the ipsilateral side than the other types (p = 0.0024). In particular, all patients with Type 2a had cervical lymph node metastasis only on the ipsilateral side (p = 0.0212). This study suggests that the distribution of metastasised cervical lymph nodes depends on the pattern of tumour extent of the primary site.

Spin correlations of strongly interacting massive fermion pairs as a test of Bell's inequality

We report the results of the first-time test of the local hidden variable theories (Bell-Clauser-Horne-Shimony-Holt) involving strongly interacting pairs of massive spin 1/2 hadrons from the decay of short-lived (tau<10;-21sec) 2He spin-singlet state, populated in the nuclear reaction 2H+;1H-->;2He+n. The novel features of this experiment are (a) the use of an 'event-ready' [corrected] detector of nearly 100% efficiency to prepare an unbiased sample and (b) a focal-plane polarimeter of full 2pi sr acceptance with a random "post selection" of the reference axes. The spin-correlation function is deduced to be S[exp](pi/4)=2.83+/-0.24stat+/-0.07sys. This result is in agreement with nonlocal quantum mechanical prediction and it violates the Bell-CHSH inequality of |S|<or=2 at a confidence level of 99.3%.

Cloning and characterization of an ascidian homolog of the human 8-oxoguanine DNA glycosylase (Ogg1) that is involved in the repair of 8-oxo-7,8-dihydroguanine in DNA in Ciona intestinalis

PURPOSE

It is of interest to perform a systematic comparative analysis of the conserved domains in DNA glycosylases and the evolution of DNA base excision repair systems. Furthermore, it is important to characterize the roles and regulation of base excision repair during the development of organisms. To address these issues, we first identified 8-oxo-7,8-dihydroguanine (8-oxoG)-DNA glycosylase (Ogg1) of the ascidian Ciona intestinalis as a good model system.

MATERIALS AND METHODS

A cDNA clone coding for a peptide with homology to human Ogg1 was identified in the expressed sequence tag (EST) database from the Ciona cDNA resources. We examined whether CiOgg1 has DNA glycosylase/AP (apurinic/apyrimidinic) lyase activities for 8-oxoG-containing oligonucleotide. Furthermore, the expression level of CiOgg1 was compared in various tissues of Ciona intestinalis.

RESULTS

The CiOgg1gene encoded a protein of 351 amino acids, which shows 37% identity of amino acid sequence with human Ogg1. The Helix-hairpin-Helix motif was highly conserved. The ascidian enzyme had functional 8-oxoG-DNA glycosylase/AP lyase activities, which removed 8-oxoG opposite cytosine from DNA. Expression of the CiOgg1 significantly reduced the frequency of spontaneous G:C to T:A transversions in E. coli mutM mutY. The highest expression level was observed in testis in Ciona intestinalis.

CONCLUSIONS

The structure and functions of Ogg1 are well conserved in Ciona intestinalis. CiOgg1 is involved in the repair of 8-oxoG in DNA in Ciona intestinalis.

Proteasome inhibitor, bortezomib, potently inhibits the growth of adult T-cell leukemia cells both in vivo and in vitro

Adult T-cell leukemia (ATL) is a fatal neoplasm derived from CD4-positive T-lymphocytes, and regardless of intensive chemotherapy, its mean survival time is less than 1 year. Nuclear factor-kappaB (NF-kappaB) activation was reported in HTLV-I associated cells, and has been implicated in oncogenesis and resistance to anticancer agents and apoptosis. We studied the effect of a proteasome inhibitor, bortezomib (formerly known as PS-341), on ATL cells in vitro and in vivo. Bortezomib could inhibit the degradation of IkappaBalpha in ATL cells, resulting in suppression of NF-kappaB and induction of cell death in ATL cells in vitro. Susceptibilities to bortezomib were well correlated with NF-kappaB activation, suggesting that suppression of the NF-kappaB pathway was implicated in the cell death induced by bortezomib. Although the majority of the cell death was apoptosis, necrotic cell death was observed in the presence of a caspase inhibitor, z-VAD-fmk. When bortezomib was administered into SCID mice bearing tumors, it suppressed tumor growth in vivo, showing that bortezomib was effective against ATL cells in vivo. These studies revealed that bortezomib is highly effective against ATL cells in vitro and in vivo by induction of apoptosis, and its clinical application might improve the prognosis of patients with this fatal disease.

Further characterization of genes expressed during Ciona intestinalis metamorphosis

Metamorphosis of ascidians is a dynamic event by which a nonfeeding, mobile tadpole larva is transformed into a filter-feeding, fixed juvenile. This process usually begins with the settlement of the larva and is followed by a series of coordinated morphogenetic movements that rearrange organs, tissues, and cells. To identify genes that are involved in the initiation of metamorphosis, we conducted differential screening between mRNAs of swimming larvae and those of juveniles in Ciona intestinalis. This screening permitted the isolation of cDNA clones for genes whose expression is upregulated during metamorphosis, and the characterization of four such genes (Ci-meta3, Ci-meta4, Ci-meta5 and Ci-meta6) is reported here. Ci-meta3 encodes a protein with a domain found in Sp1a and the RYanodine receptor. This gene is not expressed in early swimming larvae but is expressed in the endoderm region and part of the retractile tail region in metamorphosing juveniles. The predicted proteins encoded by Ci-meta4, Ci-meta5 and Ci-meta6 do not contain any known consensus motifs, nor do they show any similarity to known proteins. Ci-meta4 and Ci-meta5 are expressed weakly in mesenchyme cells of the early larva and strongly in the metamorphosing juvenile, while Ci-meta6 is expressed in the mesenchyme in the late larva. In addition, we characterized 53 independent cDNA clones whose expression was downregulated during the period from early swimming larvae to metamorphosing juveniles by taking advantage of the Ciona intestinalis cDNA project database and BLAST searches. The expression patterns of some of these clones were changed during the larval period.

Isovector quadrupole resonance observed in the 60Ni(13C,13N)60Co reaction at E/A=100 MeV

The charge-exchange reaction 60Ni(13C,13N)60Co at E/A=100 MeV has been studied to locate isovector (deltaT=1) non-spin-flip (deltaS=0) giant resonances. Besides the giant dipole resonance at E(x)=8.7 MeV, another resonance has been observed at E(x)=20 MeV with a width of 9 MeV. Distorted-wave Born approximation analysis on the angular distribution clearly indicated the L=2 multipolarity, attributing the E(x)=20 MeV state to the giant isovector quadrupole resonance.

Profiles of maternally expressed genes in fertilized eggs of Ciona intestinalis

A set of 1,378 expressed sequence tags (ESTs), both the 5'-most and 3'-most ends, derived from Ciona intestinalis fertilized eggs was categorized into 1,003 independent clusters. When compared with sequences in databases, 452 of the clusters showed significant matches with reported proteins, while 190 showed matches with putative proteins for which there is not enough information to categorize their function, and 361 had no significant similarities to known proteins. Sequence similarity analyses of the 452 clusters in relation to the biological function as well as the structure of the message population at this stage demonstrated that 362 of them have functions that many kinds of cells use, 65 are associated with cell-cell communication, including a candidate cDNA for sonic hedgehog, and 25 are transcription factors. Sequence prevalence distribution analysis demonstrated that the great majority (78%) of the mRNAs are rare mRNAs or are represented by a single clone/cluster. All of the 1,003 clusters were subjected to whole-mount in situ hybridization to analyze the distribution of the maternal mRNAs in fertilized eggs, and a total of 329 genes showed localized distribution of the mRNAs: 16 showed cortical localization, 12 showed mitochondrial-like distribution, 99 crescent-like distribution, 63 partial localization, and 139 weak localization. When the distribution pattern of all the maternally expressed mRNAs was examined in the 8-cell stage embryos, it became evident that 248 genes which have localized mRNA patterns at the fertilized egg stage lose their localized distribution by the 8-cell stage. In contrast, 13 genes newly gain a localized pattern by the 8-cell stage. In addition, a total of 39 genes showed distinct in situ signals in the nucleus of blastomeres of the 8-cell stage embryo, suggesting early zygotic expression of these genes by this stage. These results suggest that complicated cytoplasmic movements are associated with the characteristic distribution of maternal mRNAs, which in turn support proper embryonic axis formation and establishment of the genetic network for embryonic cell specification.

Ci-opsin1, a vertebrate-type opsin gene, expressed in the larval ocellus of the ascidian Ciona intestinalis

A novel gene encoding visual pigment, Ci-opsin1, was identified in a primitive chordate, the ascidian, Ciona intestinalis. Molecular phylogenetic analysis and the exon-intron organization suggest that Ci-opsin1 is closely related to the retinal and pineal opsins of vertebrates. During embryogenesis, Ci-opsin1 transcripts were first detected in part of the brain of mid tailbud embryos; its expression was confined to photoreceptor cells of the ocellus (eye spot) in the larval brain as development proceeded. These results suggest a common descent of the ascidian ocellus and the vertebrate eyes. The ocellus of ascidian larvae may represent an ancestral state of the vertebrate eye.

Early embryonic expression of a LIM-homeobox geneCs-lhx3is downstream of β-catenin and responsible for the endoderm differentiation inCiona savignyiembryos

In early Ciona embryos, nuclear accumulation of β-catenin is most probably the first step of endodermal cell specification. If β-catenin is mis- and/or overexpressed, presumptive notochord cells and epidermal cells change their fates into endodermal cells, whereas if β-catenin nuclear localization is downregulated by the overexpression of cadherin, the endoderm differentiation is suppressed, accompanied with the differentiation of extra epidermal cells (Imai, K., Takada, N., Satoh, N. and Satou, Y. (2000) Development127, 3009-3020). Subtractive hybridization screens of mRNAs between β-catenin overexpressed embryos and cadherin overexpressed embryos were conducted to identify potential β-catenin target genes that are responsible for endoderm differentiation in Ciona savignyi embryos. We found that a LIM-homeobox gene (Cs-lhx3), an otx homolog (Cs-otx) and an NK-2 class gene (Cs-ttf1) were among β-catenin downstream genes. In situ hybridization signals for early zygotic expression of Cs-lhx3 were evident only in the presumptive endodermal cells as early as the 32-cell stage, those of Cs-otx in the mesoendodermal cells at the 32-cell stage and those of Cs-ttf1 in the endodermal cells at the 64-cell stage. Later, Cs-lhx3 was expressed again in a set of neuronal cells in the tailbud embryo, while Cs-otx was expressed in the anterior nervous system of the embryo. Expression of all three genes was upregulated in β-catenin overexpressed embryos and downregulated in cadherin overexpressed embryos. Injection of morpholino oligonucleotides against Cs-otx did not affect the embryonic endoderm differentiation, although the formation of the central nervous system was suppressed. Injection of Cs-ttf1 morpholino oligonucleotides also failed to suppress the endoderm differentiation, although injection of its synthetic mRNAs resulted in ectopic development of endoderm differentiation marker alkaline phosphatase. By contrast, injection of Cs-lhx3 morpholino oligo suppressed the endodermal cell differentiation and this suppression was rescued by injection of Cs-lhx3 mRNA into eggs. In addition, although injection of delE-Ci-cadherin mRNA into eggs resulted in the suppression of alkaline phosphatase development, injection of delE-Ci-cadherin mRNA with Cs-lhx3 mRNA rescued the alkaline phosphatase development. These results strongly suggest that a LIM-homeobox gene Cs-lhx3 is one of the β-catenin downstream genes and that its early expression in embryonic endodermal cells is responsible for their differentiation.

Condylar bony change and self-reported parafunctional habits in prospective orthognathic surgery patients with temporomandibular disorders

OBJECTIVE

The purpose of this study was to investigate the relationship between self-reported parafunctional habits and condylar bony change and disk displacement in orthognathic surgery patients with signs and symptoms of temporomandibular joint disorders.

STUDY DESIGN

This is a cross-sectional retrospective study of pretreatment helical computed tomography scans and questionnaires of 94 female orthognathic surgery patients.

RESULTS

Condylar bony change, unilaterally or bilaterally, was found in 56.4% of the subjects, or 43.6% of the joints. Disk displacement, unilaterally or bilaterally, was seen in 59.6% of the subjects, or 45.7% of the joints. Bruxism and clenching was significantly associated with condylar bony change and disk displacement. Subjects with 3 or more parafunctional habits showed a significantly higher rate of bilateral condylar bony change.

CONCLUSION

Our results suggest that bruxism and clenching might be related to deterioration of the temporomandibular joint and that the greater the number of parafunctional habits a subject has, the higher the risk of condylar bony change.

Gene expression profiles in Ciona intestinalis tailbud embryos

A set of 3423 expressed sequence tags derived from the Ciona intestinalis tailbud embryos was categorized into 1213 independent clusters. When compared with DNA Data Bank of Japan database, 502 clusters of them showed significant matches to reported proteins with distinct function, whereas 184 lacked sufficient information to be categorized (including reported proteins with undefined function) and 527 had no significant similarities to known proteins. Sequence similarity analyses of the 502 clusters in relation to the biosynthetic function, as well as the structure of the message population at this stage, demonstrated that 390 of them were associated with functions that many kinds of cells use, 85 with cell-cell communication and 27 with transcription factors and other gene regulatory proteins. All of the 1213 clusters were subjected to whole-mount in situ hybridization to analyze the gene expression profiles at this stage. A total of 387 clusters showed expression specific to a certain tissue or organ; 149 showed epidermis-specific expression; 34 were specific to the nervous system; 29 to endoderm; 112 to mesenchyme; 32 to notochord; and 31 to muscle. Many genes were also specifically expressed in multiple tissues. The study also highlighted characteristic gene expression profiles dependent on the tissues. In addition, several genes showed intriguing expression patterns that have not been reported previously; for example, four genes were expressed specifically in the nerve cord cells and one gene was expressed only in the posterior part of muscle cells.

This study provides molecular markers for each of the tissues and/or organs that constitutes the Ciona tailbud embryo. The sequence information will also be used for further genome scientific approach to explore molecular mechanisms involved in the formation of one of the most primitive chordate body plans.

Action of morpholinos in Ciona embryos

First, using morpholino against lacZ, we demonstrate that the morpholino specifically suppresses the translation of the gene introduced exogenously into Ciona eggs. Second, using morpholino against an alkaline phosphatase gene, we show that the morpholino suppresses the translation of the endogenous gene as well. Third, using morpholino against beta-catenin gene, we confirm that the suppression by the morpholino can be rescued by injection of beta-catenin mRNA. All of these results indicate that morpholino act in Ciona embryos to specifically block the function of endogenous genes as well as exogenously introduced genes. genesis 30: 103--106, 2001.

Brachyury (T) gene expression and notochord development in Oikopleura longicauda (Appendicularia, Urochordata)

Appendicularia (Larvacea) is a subgroup of Urochordata (Tunicata) comprised of holoplanktonic organisms that retain their tailed architecture throughout their life history, while other tunicates, including ascidians and doliolids, resorb the tail after metamorphosis. In order to investigate the characteristics of the appendicularian unresorbed notochord, we isolated a partial genomic clone and a full-length cDNA sequence homologous to the mouse Brachyury (T) gene from the appendicularian Oikopleura longicauda. Brachyury is known to be predominantly expressed in the notochord cells and plays an important role in their differentiation in other chordates. While phylogenetic analysis robustly supports the orthology of the isolated Brachyury gene, the exon-intron organization found in the genomic clone was distinct from that well-conserved among other T-box genes. In addition to a detailed observation of notochord development in living specimens, whole-mount double in situ hybridization was carried out using a Brachyury probe along with a muscle actin probe. The Brachyury transcripts were found in the notochord of the tailbud embryos and persisted into later stages. The present study highlights characteristics of notochord development in the appendicularian. Furthermore, these results provide basic knowledge for comprehensive understanding of the cellular- and molecular-based mechanisms needed to build the characteristic cytoarchitecture of notochord that varies among tunicate species.