A central paradigm in radiation biology has been that only cells ‘hit’ by a track of radiation would be affected to induce radiobiological consequences, and cells ‘not hit’ should not be. This is the basis of the current system for risk estimation of radiobiological effects. However, it has recently been challenged by so-called non-targeted effects, such as bystander effect, and such radiation-induced cellular responses may have important implications for risk evaluation of low-dose-rate radiations as well as in tumor radiotherapy. Our group has been studying radiation-quality bystander cellular effects using the microbeams with different radiation sources.
It is essentially important for evaluating risk such a low-dose-rate exposure as the accident of Fukushima Daiichi Nuclear Power Plants to examine bystander effects induced by low-LET electromagnetic radiations, such as X or gamma rays. We have been studying the cellular responses in normal human fibroblasts by targeted cell nucleus irradiations with monochromatic X-ray microbeams (5.35 keV) produced by Photon Factory in High Energy Accelerator Research Organization. The results indicated that the bystander effect in cell- killing effect was observed in the targeted cell nucleus irradiation, not in the random irradiation containing both cell nucleus and cytoplasm by Poisson distribution. The results suggest that energy deposition in cytoplasm is an important role of inducing bystander effects in case of low-LET radiations.
We have also been investigating high-LET-radiation induced bystander effects using the heavy-ion microbeams at Takasaki Ion Accelerators for Advanced Radiation Application in Japan Atomic Energy Agency. Only 0.04% of the total numbers of normal human fibroblasts were irradiated with C-ion (220 MeV), Ne-ion (260 MeV) and Ar-ion (460 MeV) microbeams collimated at 20 μm in diameter. Cell-killing effect and gene mutation at HPRT locus in the cells irradiated with C ions were higher beyond our expectations and returned the estimated values that only 0.04% of the total cells were irradiated when using the specific inhibitor of gap junctions. On the other hand, no induced biological effects were observed in Ne and Ar ions whether the inhibitor was applied or not. The result suggested that the C-ion microbeam was capable of inducing bystander cellular effects via gap junction-mediated cell-cell communication. There is clear evidence that bystander cellular effects are dependent on radiation quality.
It is also important for highly developed heavy-ion radiotherapy to identify bystander effects induced by spatially low-fluence irradiations with heavy-ion beams. We have been investigating the biological effects using human tumor cell lines. The results clearly showed that bystander effects were observed in the carbon-ion irradiation but not in other ions as well as the effects in normal fibroblasts. Furthermore, the bystander cell-killing effect in tumor cell lines was strongly induced in the cells harboring wild-type P53 not in mutated-type P53 cells. The results provide the important implication for a tailor-made therapy using carbon ions.
Bystander effect; Microbeam; Gap junction, P53, HPRT
Brain lesions originating from metastasis of colorectal cancer represent 3–5% of all brain metastases and are relatively rare. Of all distant metastases of colorectal cancer, those to the liver are detected in 22–29% of cases, while those to the lungs are detected in 8–18% of cases. In contrast, brain metastasis is quite rare, with a reported incidence ranging from 0.4 to 1.8%. Treatments for metastatic brain tumors include surgery, radiotherapy, chemotherapy and supportive care with steroids, etc. Untreated patients exhibit a median survival of only approximately 1 month. The choice of treatment for brain metastasis depends on the number of lesions, the patient's general condition, nerve findings and presence of other metastatic lesions. We herein report the case of a 78-year-old male who presented with brain metastases originating from rectal carcinoma. He suffered from nausea, vomiting, anorexia and vertigo during body movement. He received antiemetics, glycerol and whole brain radiation therapy; however, these treatments proved ineffective. Olanzapine therapy was started at a dose of 1.25 mg every night. The persistent nausea disappeared the next day, and the frequency of vomiting subsequently decreased. The patient was able to consume solid food. Olanzapine is an antipsychotic that has recently been used as palliative therapy for refractory nausea and vomiting in patients receiving chemotherapy. We consider that olanzapine was helpful as a means of supportive care for the treatment of nausea and vomiting due to brain metastasis.
Olanzapine; Nausea; Vomiting; Brain tumor
To detect the radiosensitivity of intratumour quiescent (Q) cells unlabelled with pimonidazole to accelerated carbon ion beams and the boron neutron capture reaction (BNCR).
EL4 tumour-bearing C57BL/J mice received 5-bromo-29-deoxyuridine (BrdU) continuously to label all intratumour proliferating (P) cells. After the administration of pimonidazole, tumours were irradiated with c-rays, accelerated carbon ion beams or reactor neutron beams with the prior administration of a 10B-carrier. Responses of intratumour Q and total (P+Q) cell populations were assessed based on frequencies of micronucleation and apoptosis using immunofluorescence staining for BrdU. The response of pimonidazole-unlabelled tumour cells was assessed by means of apoptosis frequency using immunofluorescence staining for pimonidazole.
Following c-ray irradiation, the pimonidazole-unlabelled tumour cell fraction showed significantly enhanced radiosensitivity compared with the whole tumour cell fraction, more remarkably in the Q than total cell populations. However, a significantly greater decrease in radiosensitivity in the pimonidazole-unlabelled cell fraction, evaluated using a delayed assay or a decrease in radiation dose rate, was more clearly observed among the Q than total cells. These changes in radiosensitivity were suppressed following carbon ion beam and neutron beam-only irradiaton. In the BNCR, the use of a 10B-carrier, especially L-para-boronophenylalanine-10B, enhanced the sensitivity of the pimonidazole-unlabelled cells more clearly in the Q than total cells.
The radiosensitivity of the pimonidazole-unlabelled cell fraction depends on the quality of radiation delivered and characteristics of the 10B-carrier used in the BNCR.
Advances in knowledge
The pimonidazole-unlabelled subfraction of Q tumour cells may be a critical target in tumour control.
Meningiomas are often embolized before their surgical resection to reduce blood loss during surgery. Polyvinyl alcohol (PVA) particles have been the most frequently used material for embolization of meningiomas. We have used n-butyl cyanoacrylate (NBCA) as the first-choice material since 2001. Thirty-one meningiomas were embolized with NBCA. We report the result of embolization of meningiomas with NBCA in comparison with PVA particles.
meningioma, preoperative embolization, n-butyl cyanoacrylate
To evaluate the effects of employing a 10B-carrier and manipulating intratumour hypoxia on local tumour response and lung metastatic potential in boron neutron capture therapy (BNCT) by measuring the response of intratumour quiescent (Q) cells.
B16-BL6 melanoma tumour-bearing C57BL/6 mice were continuously given 5-bromo-2′-deoxyuridine (BrdU) to label all proliferating (P) cells. The tumours received reactor thermal neutron beam irradiation following the administration of a 10B-carrier [L-para-boronophenylalanine-10B (BPA) or sodium mercaptoundecahydrododecaborate-10B (BSH)] in combination with an acute hypoxia-releasing agent (nicotinamide) or mild temperature hyperthermia (MTH). Immediately after the irradiation, cells from some tumours were isolated and incubated with a cytokinesis blocker. The responses of the Q and total (P+Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumour-bearing mice, macroscopic lung metastases were enumerated 17 days after irradiation.
BPA-BNCT increased the sensitivity of the total tumour cell population more than BSH-BNCT. However, the sensitivity of Q cells treated with BPA was lower than that of BSH-treated Q cells. With or without a 10B–carrier, MTH enhanced the sensitivity of the Q cell population. Without irradiation, nicotinamide treatment decreased the number of lung metastases. With irradiation, BPA-BNCT, especially in combination with nicotinamide treatment, showed the potential to reduce the number of metastases more than BSH-BNCT.
BSH-BNCT in combination with MTH improves local tumour control, while BPA-BNCT in combination with nicotinamide may reduce the number of lung metastases.
The aim was to evaluate the influence of bevacizumab on intratumour oxygenation status and lung metastasis following radiotherapy, with specific reference to the response of quiescent (Q) cell populations within irradiated tumours.
B16-BL6 melanoma tumour-bearing C57BL/6 mice were continuously given 5-bromo-2-deoxyuridine (BrdU) to label all proliferating (P) cells. They received γ-ray irradiation following treatment with the acute hypoxia-releasing agent nicotinamide or local mild temperature hyperthermia (MTH) with or without the administration of bevacizumab under aerobic conditions or totally hypoxic conditions, achieved by clamping the proximal end of the tumours. Immediately after the irradiation, cells from some tumours were isolated and incubated with a cytokinesis blocker. The responses of the Q and total (P + Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In the other tumour-bearing mice, macroscopic lung metastases were enumerated 17 days after irradiation.
3 days after bevacizumab administration, acute hypoxia-rich total cell population in the tumour showed a remarkably enhanced radiosensitivity to γ-rays, and the hypoxic fraction (HF) was reduced, even after MTH treatment. However, the hypoxic fraction was not reduced after nicotinamide treatment. With or without γ-ray irradiation, bevacizumab administration showed some potential to reduce the number of lung metastases as well as nicotinamide treatment.
Bevacizumab has the potential to reduce perfusion-limited acute hypoxia and some potential to cause a decrease in the number of lung metastases as well as nicotinamide.
A 60-year-old man with direct carotid cavernous fistula (CCF) due to a motor vehicle accident underwent internal carotid artery trapping following high-flow external carotid to internal carotid artery bypass (EC-IC bypass). Follow-up angiography revealed ipsilateral complex indirect cavernous arteriovenous fistula. Although the traumatic indirect CCF angioarchitecture differs from cavernous-sinus dural arteriovenous fistula (CS-DAVF), the present indirect fistula was similar to the latter. Complex indirect CCF can occur after treatment of direct CCF caused by severe head injury.
traumatic CCF, dural arteriovenous fistula, endovascular treatment
We describe a case of subarachnoid hemorrhage due to a ruptured right vertebral artery (VA) aneurysm where endovascular therapy via a trans-femoral route was not feasible. Therefore we surgically exposed the VA and directly punctured it at the C4 level, followed by successful coil embolization. Direct access to the vertebral artery using an anterior surgical approach is an alternative in cases where the proximal side of the artery is occluded.
vertebral artery aneurysm, coil embolization, surgical exposure, direct puncture
In this article we report a case of desmoplastic ameloblastoma in which chronological changes in the early development can be observed on dental radiographs. The tumour grew very slowly and did not appear to have a strong potential for local extension like typical ameloblastomas. Radiological findings of our case suggest the tumour arose from the periodontal membrane. However, it was not possible to obtain conclusive histopathological evidence.
desmoplastic ameloblastoma; imaging; diagnosis
The purpose of this study was to evaluate the influence of manipulating intratumour oxygenation status and radiation dose rate on local tumour response and lung metastases following radiotherapy, referring to the response of quiescent cell populations within irradiated tumours. B16-BL6 melanoma tumour-bearing C57BL/6 mice were continuously given 5-bromo-2′-deoxyuridine (BrdU) to label all proliferating (P) cells. They received γ-ray irradiation at high dose rate (HDR) or reduced dose rate (RDR) following treatment with the acute hypoxia-releasing agent nicotinamide or local hyperthermia at mild temperatures (MTH). Immediately after the irradiation, cells from some tumours were isolated and incubated with a cytokinesis blocker. The responses of the quiescent (Q) and total (proliferating + Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumour-bearing mice, 17 days after irradiation, macroscopic lung metastases were enumerated. Following HDR irradiation, nicotinamide and MTH enhanced the sensitivity of the total and Q-cell populations, respectively. The decrease in sensitivity at RDR irradiation compared with HDR irradiation was slightly inhibited by MTH, especially in Q cells. Without γ-ray irradiation, nicotinamide treatment tended to reduce the number of lung metastases. With γ-rays, in combination with nicotinamide or MTH, especially the former, HDR irradiation decreased the number of metastases more remarkably than RDR irradiation. Manipulating both tumour hypoxia and irradiation dose rate have the potential to influence lung metastasis. The combination with the acute hypoxia-releasing agent nicotinamide may be more promising in HDR than RDR irradiation in terms of reducing the number of lung metastases.
The advent of massively parallel sequencing (MPS) technology has lead to the development of assays which facilitate the study of epigenomics and genomics at the genome-wide level. However, the computational burden resulting from the need to store and process the gigbytes of data streaming from sequencing machines, in addition to collecting metadata and returning data to users, is becoming a major issue for both sequencing cores and users alike. We present WASP, a LIMS system designed to automate MPS data pre-processing and analysis. WASP integrates a user-friendly MediaWiki front end, a network file system (NFS) and MySQL database for recording experimental data and metadata, plus a multi-node cluster for data processing. The workflow includes capture of sample submission information to the database using web forms on the wiki, recording of core facility operations on samples and linking of samples to flowcells in the database followed by automatic processing of sequence data and running of data analysis pipelines following the sequence run. WASP currently supports MPS using the Illumina GaIIx. For epigenomics applications we provide a pipeline for our novel HpaII-tiny fragment enrichment by ligation-mediated PCR (HELP)-tag method which enables us to quantify the methylation status of ∼1.8 million CpGs located in 70% of the HpaII sites (CCGG) in the human genome. We also provide ChIP-seq analysis using MACS, which is also applicable for methylated DNA immunoprecipitation (MeDIP) assays, in addition to miRNA and mRNA analyses using custom pipelines. Output from the analysis pipelines is automatically linked to a users wiki-space and the data generated can be immediately viewed as tracks in a local mirror of the UCSC genome browser. WASP also provides capabilities for automated billing and keeping track of facility costs. We believe WASP represents a suitable model on which to develop LIMS systems for supporting MPS applications.
Dural arteriovenous fistula (d-AVF) is relatively rare. Some cases of atypical locations are often difficult to distinguish from other vascular disorders or tumors because those d-AVFs show various onsets, such as subcortical bleeding and venous infarctions. We encountered two cases of d-AVF with severe brain edema that took adequate time to distinguish from brain tumors. A 68-year-old man visited his local physician complaining of dizziness. He was diagnosed with a cerebral infarction due to the presence of an abnormal cerebellar signal on magnetic resonance imaging (MRI) and was treated by drip infusion. However, he did not recover and was admitted to our hospital with suspicion of a brain tumor. A 75-year-old woman with an onset of progressive dementia and gait disturbance showed severe edema of the right-front temporal lobe on MRI. Both these cases were examined by single photon emission computed tomography or positron emission tomography and were scheduled for craniotomy and biopsy based on the diagnosis of brain tumor. We performed preoperative angiography and found d-AVFs. We embolized the d-AVFs with liquid material and both patients recovered well.
Brain edema from d-AVF or a tumor can be distinguished by carefully reading the MRI with findings such as the distribution of the edemas, differences on diffusion-weighted images, and contrast-enhanced images. Therefore, it is important to provide initial accurate diagnoses to prevent patient mistrust and irreversible disease conditions.
dural arteriovenous fistula, magnetic resonance imaging, tumor, venous congestion
Cl− channels are widely found anion pores that are regulated by a variety of signals and that play various roles. On the basis of molecular biologic findings, ligand-gated Cl− channels in synapses, cystic fibrosis transmembrane conductors (CFTRs) and ClC channel types have been established, followed by bestrophin and possibly by tweety, which encode Ca2+-activated Cl− channels. The ClC family has been shown to possess a variety of functions, including stabilization of membrane potential, excitation, cellvolume regulation, fluid transport, protein degradation in endosomal vesicles and possibly cell growth. The molecular structure of Cl− channel types varies from 1 to 12 transmembrane segments. By means of computer-based prediction, functional Cl− channels have been synthesized artificially, revealing that many possible ion pores are hidden in channel, transporter or unidentified hydrophobic membrane proteins. Thus, novel Cl−-conducting pores may be occasionally discovered, and evidence from molecular biologic studies will clarify their physiologic and pathophysiologic roles.
ClC; CFTR; bestrophin; tweety; volume regulation; Ca2+ activation; pharmacology; knockout mouse
The prevalence of colon cancer has seen strong demand in screening for colorectal neoplasia, and this has drawn considerable attention to the technological advances in Computed Tomographic Colonography (CTC). With the assistance of an oral contrast agent, an imaging technique known as Electronic Cleansing (EC), can affect virtual cleaning of the computed tomography (CT) images, to remove fecal material that is tagged by the agent. Technical problems can arise with electronic cleansing however, when the air lumen causes distortions to the tagged regions which result in partial volume effects.
Combining the simple image arithmetic of an electronic cleansing algorithm, with a vertical motion filter at the fluid level of the bowel, artifacts such as those caused by an air lumen are eliminated. Essentially, the filter becomes a vector for that carries the measurement of vertical motion to neutralise the artifact that is causing partial volume effects. Results demonstrate that despite its simplicity, this technique offers accuracy and is able to successfully maintain the normal intra-colonic structure, while supporting digital leaning of tagged residual material appearing on the colon wall.
Electronic cleansing; CT colonography
We describe a 24-year-old woman who presented with twice previously unverified subarachnoid hemorrhages from the conus me-dullaris spinal arteriovenous malformation with Parkes-Weber-syndrome.
Spinal MRI examination is considered to be necessary for the diagnosis of Klippel-Trenaunay-Weber syndro-me. For diagnosis of the spinal cord arteriovenous malformation, it is indispensable to search carefully for the presence of accompanying lesions. Transarterial glue embolization is effective for the management of the spinal vascular lesion.
spinal arteriovenous malformation, Klippel-Trenaunay-Weber, pseudoaneurysm, embolization
The expression and activity of the epidermal growth factor receptor (EGFR) are determinants of radiosensitivity in several tumour types, including non-small cell lung cancer (NSCLC). However, little is known of whether genetic alterations of EGFR in NSCLC cells affect the therapeutic response to monoclonal antibodies (mAbs) to EGFR in combination with radiation. We examined the effects of nimotuzumab, a humanised mAb to EGFR, in combination with ionising radiation on human NSCLC cell lines of differing EGFR status. Flow cytometry revealed that H292 and Ma-1 cells expressed high and moderate levels of EGFR on the cell surface, respectively, whereas H460, H1299, and H1975 cells showed a low level of surface EGFR expression. Immunoblot analysis revealed that EGFR phosphorylation was inhibited by nimotuzumab in H292 and Ma-1 cells but not in H460, H1299, or H1975 cells. Nimotuzumab augmented the cytotoxic effect of radiation in H292 and Ma-1 cells in a clonogenic assay in vitro, with a dose enhancement factor of 1.5 and 1.3, respectively. It also enhanced the antitumor effect of radiation on H292 and Ma-1 cell xenografts in nude mice, with an enhancement factor of 1.3 and 4.0, respectively. Nimotuzumab did not affect the radioresponse of H460 cells in vitro or in vivo. Nimotuzumab enhanced the antitumor efficacy of radiation in certain human NSCLC cell lines in vitro and in vivo. This effect may be related to the level of EGFR expression on the cell surface rather than to EGFR mutation.
epidermal growth factor receptor; non-small cell lung cancer; nimotuzumab; monoclonal antibody; genetic alteration; radiosensitisation
We describe the treatment and follow-up clinical symptoms and angiographic results in patients with dural arteriovenous fistula of the cavernous sinus treated by transvenous embolization (TVE). We have treated eight cases of dural arteriovenous fistula of the cavernous sinus by multi-staged TVE in two cases and TVE with sinus packing in six and three of six cases were treated with a combination of transarterial embolization. Multi-staged TVE was performed by occlusion from dangerous drainage veins to the cavernous sinus on several occasions.
Angiographical results showed disappearance or reduction of the arteriovenous shunt in all cases. Six patients presented with ophthalmic symptoms and two had tinnitus. Six cases had complete disappearance of clinical symptoms after treatment. There was a deterioration of ocular movement in one patient treated by TVE with sinus packing. Multi-staged TVE was performed to reduce the coil volume for the packing of the cavernous sinus in two cases without cranial nerve palsy. Embolization, especially multi-staged TVE, was considered a good treatment to occlude arteriovenous shunts at the cavernous sinus without cranial nerve complications.
arteriovenous shunt, cavernous sinus, multi-staged embolization