Frequency and features of myasthenia gravis developing after thymectomy.

BACKGROUND AND PURPOSE: Thymectomy is an effective treatment for myasthenia gravis (MG) with anti-acetylcholine receptor (AChR) antibodies. We rarely encounter patients who develop MG after surgery for thymic tumors. This study aimed to investigate the characteristics and frequency of post-thymectomy onset (PostTx) MG. METHODS: We reviewed the clinical information of thymoma-associated MG in 158 patients. Of these, 18 (11%) patients with PostTx MG were identified. RESULTS: The presence of anti-AChR antibodies (82%) and electrophysiological abnormalities (50%) was confirmed before thymectomy in patients with PostTx MG. The clinical characteristics of PostTx MG were similar to those of pre-thymectomy onset (PreTx) MG. In PostTx MG, the duration between thymectomy and MG onset were distributed as < 6 months (early-onset PostTx MG) and ≥ 6 months (late-onset PostTx MG). Notably, some patients with late-onset PostTx MG were associated with thymoma relapse. CONCLUSION: Our results suggest that approximately 11% of patients with thymoma-associated MG were PostTx MG and pre-surgical assessment of anti-AChR antibody titer or electrophysiological testing may predict PostTx MG development. However, no difference in clinical manifestation and prognosis was observed between PreTx MG and PostTx MG.

Safety of tapering tacrolimus dose in patients with well-controlled anti-acetylcholine receptor antibody-positive myasthenia gravis.

BACKGROUND AND PURPOSE: Tapering immunosuppressants is desirable in patients with well-controlled myasthenia gravis (MG). However, the association between tapering of calcineurin inhibitor dosage and reduction-associated exacerbation is not known. The aim of this study was to clarify the frequency of reduction-associated exacerbation when tacrolimus is tapered in stable patients with anti-acetylcholine receptor antibody-positive MG, and to determine the factors that predict exacerbations. METHODS: We retrospectively analyzed 115 patients in whom tacrolimus dosage was tapered. The reduction-associated exacerbation was defined as the appearance or worsening of one or more MG symptoms <3 months after the reduction. RESULTS: Tacrolimus dosage was successfully tapered in 110 patients (96%) without any exacerbation. Five patients (4%) experienced an exacerbation, but symptoms were reversed in all patients when the tacrolimus dose was increased to the previous maintenance level. No patient developed an MG crisis. The age at onset was significantly earlier (30 vs. 56 years, P = 0.025) and the reduction in dosage was significantly larger (2.0 vs. 1.0 mg/day, P = 0.002) in patients with reduction-associated exacerbation than in those without exacerbation. The cut-off values determined in a receiver-operating characteristic curve analysis were 52 years (sensitivity, 57%; specificity, 100%) for the age at onset and 1.5 mg (sensitivity, 80%; specificity, 100%) for the dose reduction. CONCLUSION: Tapering of tacrolimus was possible in most patients with well-controlled anti-acetylcholine receptor antibody-positive MG. Early age at onset and a large reduction from maintenance dosage were associated with exacerbation. Reductions ≤1.5 mg/day from the maintenance dosage should be considered for patients with late-onset disease.

First report of hepatobiliary Mycobacterium avium infection developing obstructive jaundice in a patient with neutralizing anti-interferon-gamma autoantibodies.

This study describes a patient who experienced hepatobiliary Mycobacterium avium infection associated with neutralizing anti-interferon gamma (IFN-γ) autoantibodies during treatment for disseminated M. avium disease. Hepatobiliary M. avium infection should be considered in jaundiced patients with neutralizing anti-IFN-γ autoantibodies, including those receiving antimycobacterial therapy for disseminated M. avium disease.

Significance of measurement of serum trough level and anti-drug antibody of adalimumab as personalised pharmacokinetics in patients with Crohn's disease: a subanalysis of the DIAMOND trial.

BACKGROUND: Significance of monitoring adalimumab trough levels and anti-adalimumab antibodies (AAA) for disease outcome in Crohn's disease (CD) patients remained unclear. AIM: To evaluate the association of adalimumab trough levels and AAA at week 26 with clinical remission at week 52, the effect of azathiopurine on AAA and factors influencing trough levels in CD patients in the DIAMOND trial. METHODS: We performed this study using adalimumab trough levels, AAA at week 26 and 6-thioguanine nucleotide (TGN) in red blood cells at week 12. A multiple regression model and receiver operating analysis was performed to identify factors influencing adalimumab trough levels and AAA, and adalimumab thresholds for predicting disease activity. RESULTS: There was a significant difference of adalimumab trough level at week 26 between patients with disease remission and without at week 52 (7.7 ± 3.3 µg/mL vs 5.4 ± 4.3 µg/mL: P <.001). Adalimumab trough level of 5.0 µg/mL yielded optimal sensitivity and specificity for remission prediction (80.2% and 55.6%, respectively). AAA development at week 26 significantly affected remission at week 52 (P = .021), which was strongly associated with adalimumab trough levels. Female gender and increasing body weight were independently associated with low adalimumab trough levels, and female gender was associated with AAA development. A cut-off 6TGN level of >222.5 p mol/8 ×108 RBCs yielded sensitivity (100%) and specificity (60.6%) for AAA negativity. CONCLUSION: Adalimumab trough levels and AAA occurrence were significantly associated with clinical remission. Higher 6TGN affected AAA negativity. The combination therapy is beneficial in some relevant aspects for CD patients. (UMIN Registration No. 000005146).

Fluence correction factor for graphite calorimetry in a clinical high-energy carbon-ion beam.

The aim of this work is to develop and adapt a formalism to determine absorbed dose to water from graphite calorimetry measurements in carbon-ion beams. Fluence correction factors, [Formula: see text], needed when using a graphite calorimeter to derive dose to water, were determined in a clinical high-energy carbon-ion beam. Measurements were performed in a 290 MeV/n carbon-ion beam with a field size of 11 × 11 cm2, without modulation. In order to sample the beam, a plane-parallel Roos ionization chamber was chosen for its small collecting volume in comparison with the field size. Experimental information on fluence corrections was obtained from depth-dose measurements in water. This procedure was repeated with graphite plates in front of the water phantom. Fluence corrections were also obtained with Monte Carlo simulations through the implementation of three methods based on (i) the fluence distributions differential in energy, (ii) a ratio of calculated doses in water and graphite at equivalent depths and (iii) simulations of the experimental setup. The [Formula: see text] term increased in depth from 1.00 at the entrance toward 1.02 at a depth near the Bragg peak, and the average difference between experimental and numerical simulations was about 0.13%. Compared to proton beams, there was no reduction of the [Formula: see text] due to alpha particles because the secondary particle spectrum is dominated by projectile fragmentation. By developing a practical dose conversion technique, this work contributes to improving the determination of absolute dose to water from graphite calorimetry in carbon-ion beams.

Adequate tacrolimus concentration for myasthenia gravis treatment.

BACKGROUND AND PURPOSE: A single, oral dose of 3 mg/day tacrolimus, approved for myasthenia gravis (MG) treatment in Japan, was shown to reduce steroid dose and anti-acetylcholine receptor (AChR) antibody titers as well as to improve MG symptoms. However, no studies have investigated the association between tacrolimus concentration and its clinical efficacy in MG. In this study, we aimed to determine the optimal tacrolimus concentration for MG treatment. METHODS: The trough tacrolimus concentration in 51 patients with MG (positive for anti-AChR antibody, n = 48; negative for anti-AChR and anti-muscle-specific tyrosine kinase antibodies, n = 3) who received 3 mg/day tacrolimus for more than 1 year was measured using a chemiluminescent enzyme immunoassay. The clinical characteristics of patients with MG as well as the dose of prednisolone used before and after tacrolimus treatment were evaluated retrospectively. RESULTS: The median trough tacrolimus concentration was 5.4 (range, 2.9-7.6) ng/mL, which was correlated with 'minimal manifestation or better status' (P = 0.0190, r = 0.3273) and the reduction in anti-AChR antibody 1 year after tacrolimus initiation (P = 0.0170, r = 0.3465). When the cut-off value for tacrolimus was defined as 4.8 ng/mL using a receiver operating characteristic curve, patients with adequate tacrolimus concentration (≥4.8 ng/mL) showed more reduction in anti-AChR antibody titers and more improvement in MG-related activities in daily life scores. More patients with adequate tacrolimus concentration achieved 'minimal manifestation or better status' compared with those with low tacrolimus concentration. CONCLUSIONS: An adequate tacrolimus concentration is required for better MG prognosis.

Theoretical and experimental characterization of novel water-equivalent plastics in clinical high-energy carbon-ion beams.

Water-equivalent plastics are frequently used in dosimetry for experimental simplicity. This work evaluates the water-equivalence of novel water-equivalent plastics specifically designed for light-ion beams, as well as commercially available plastics in a clinical high-energy carbon-ion beam. A plastic- to-water conversion factor [Formula: see text] was established to derive absorbed dose to water in a water phantom from ionization chamber readings performed in a plastic phantom. Three trial plastic materials with varying atomic compositions were produced and experimentally characterized in a high-energy carbon-ion beam. Measurements were performed with a Roos ionization chamber, using a broad un-modulated beam of 11 × 11 cm2, to measure the plastic-to-water conversion factor for the novel materials. The experimental results were compared with Monte Carlo simulations. Commercially available plastics were also simulated for comparison with the plastics tested experimentally, with particular attention to the influence of nuclear interaction cross sections. The measured [Formula: see text] correction increased gradually from 0% at the surface to 0.7% at a depth near the Bragg peak for one of the plastics prepared in this work, while for the other two plastics a maximum correction of 0.8%-1.3% was found. Average differences between experimental and numerical simulations were 0.2%. Monte Carlo results showed that for polyethylene, polystyrene, Rando phantom soft tissue and A-150, the correction increased from 0% to 2.5%-4.0% with depth, while for PMMA it increased to 2%. Water-equivalent plastics such as, Plastic Water, RMI-457, Gammex 457-CTG, WT1 and Virtual Water, gave similar results where maximum corrections were of the order of 2%. Considering the results from Monte Carlo simulations, one of the novel plastics was found to be superior in comparison with the plastic materials currently used in dosimetry, demonstrating that it is feasible to tailor plastic materials to be water-equivalent for carbon ions specifically.

An Effective New Cryopreservation Procedure for Pancreatic Islets Using Hollow Fiber Vitrification.

The present study aimed at establishing a new cryopreservation method for mouse pancreatic islets by vitrification using hollow fibers as a container. A unique feature of the hollow fiber vitrification (HFV) method is that this method achieves stable vitrification using a minimum volume of cryoprotectant (CPA) solution, thereby ensuring high viability of the islets. The cytotoxicity, optimum composition, and concentration of the CPAs for vitrifying islets were examined. The viability, functional-integrity of vitrified islets were evaluated in comparison with those vitrified by conventional methods. Insulin secretion was measured in vitro by a static incubation assay and the metabolic functions was tested after transplantation into Streptozotocin-induced diabetic mice. The combination of 15% dimethyl sulfoxide+15% ethylene glycol resulted in the best CPA solution for the HFV of islets. HFV showed the highest viability in comparison to 2 vitrification methods, open pulled straws and vitrification with EDT324 solution. The vitrified islets stably expressed ß-cells markers NeuroD, Pancreatic and duodenal homeobox-1, and MafA. Transplantation of the vitrified islets achieved euglycemia of the host diabetic mice and response to an intraperitoneal glucose tolerance test to a similar extent as non-vitrified transplanted islets. The HFV method allows for efficient long-term cryopreservation of islets.

Operation status of the electron cyclotron resonance ion source at Gunma University.

An ECR ion source of Gunma University Heavy Ion Medical Center, so-called KeiGM [M. Muramatsu, A. Kitagawa, Y. Sakamoto, S. Sato, Y. Sato, H. Ogawa, S. Yamada, H. Ogawa, Y. Yoshida, and A. G. Drentje, Rev. Sci. Instrum. 76, 113304 (2005)], has been operated for cancer therapy and physical/biological experiment since 2010. KeiGM produces typically 230 µA of 10 keV/u C(4+) ions from CH4 gases. The vacuum pressure is kept between 1.2 × 10(-4) and 1.7 × 10(-4) Pa so as to suppress the pulse-to-pulse current fluctuation within ±10%. The extraction electrode is cleaned every 6-8 months in order to remove deposited carbon, which increases the leak current and discharge. In order to investigate the possibility of long-term operation without such maintenances, oxygen aging for the cleaning of the extraction electrode has been tested in the test bench. The same-designed ion sources at National Institute of Radiological Sciences and SAGA Heavy Ion Medical Accelerator in Tosu (SAGA-HIMAT) are also operated with stable C(4+) current, which are suitable for the continuous operation for cancer therapy.

Serum cytokine and chemokine profiles in patients with myasthenia gravis.

Myasthenia gravis (MG) is an autoimmune-mediated inflammatory disease of the neuromuscular junction. Previous studies of animal MG models have suggested important roles of cytokines in MG pathogenesis, but adequate studies on cytokines in human MG are lacking. Using a multiplex suspension array system, we measured the serum levels of 27 cytokines/chemokines in 47 anti-acetylcholine receptor antibody-positive patients with MG and 20 normal controls (NC) to investigate the contribution of cytokines/chemokines toward MG pathogenesis. Correlations between clinical parameters and cytokine/chemokine levels in patients with MG were also examined. The serum levels of interleukin (IL)-15 (mean ± standard deviation: 6·85 ± 6·97 pg/ml) and vascular endothelial growth factor (VEGF) (96·21 ± 71·60 pg/ml) significantly increased, whereas IL-4 levels (3·57 ± 0·86 pg/ml) decreased in patients with MG compared with NC (IL-15: 4·42 ± 1·55 pg/ml; VEGF: 63·51 ± 32·95 pg/ml; IL-4: 4·15 ± 0·81 pg/ml, P < 0·05). In addition, eight cytokines (IL-4, IL-8, IL-15, eotaxin, macrophage inflammatory protein-1α, macrophage inflammatory protein-1ß, VEGF and IL-1b) were significantly changed among MG patients with thymoma, MG patients without thymoma and NC (P < 0·05). Some cytokines, such as IL-4, IL-15, and VEGF, may play roles in the pathogenesis of MG.

Gastric emptying rate in subjects with malocclusion examined by [(13) C] breath test.

Masticatory function is significantly lower in individuals with malocclusion than in those with normal occlusion. Although several studies suggest that masticatory function influences gastrointestinal digestive function, the relationship between malocclusion and gastrointestinal symptoms has not been studied extensively. We hypothesised that insufficient masticatory function would increase the functional burden of the stomach and have some influence on the gastrointestinal system. The purpose of this study was to investigate masticatory function and gastric emptying rate in subjects with malocclusion. Eleven healthy dentate female volunteers and eleven female patients with maloc-clusion underwent a (13) C-acetate breath test with a liquid meal. Maximum (13) CO2 exhalation time (Tmax ) was compared statistically between both groups. Masticatory function was assessed by colour-changeable chewing gum. In addition, the frequency scale for the symptoms of gastroeso-phageal reflux disease (FSSG) and questionnaires on food intake were given to both groups. The mean Tmax of the malocclusion group was significantly longer than that of the normal occlusion group (P = 0·007). Masticatory performance, measured by colour-changeable gum and questionnaires, was significantly lower in the malocclusion group than in the normal occlusion group (P = 0·023, P = 0·003). There was no significant difference in the FSSG results between the two groups (P = 0·262). This study suggested that there was a correlation between malocclusion and gastric emptying function in women.

Sub-two-cycle, carrier-envelope phase-stable, intense optical pulses at 1.6 µm from a BiB3O6 optical parametric chirped-pulse amplifier.

We report on the generation of 9.0 fs, 550 µJ, carrier-envelope phase (CEP)-stabilized optical pulses around 1.6 µm at 1 kHz. Few-cycle IR pulses are obtained from a BiB(3)O(6) optical parametric chirped-pulse amplifier. The amplification of nearly octave-spanning ultrabroad pulses without spectral broadening results in good stability in output energy (0.85% rms) and CEP (160 mrad rms). We observed high harmonics in the water window from a neon cell that corresponds to a laser intensity of 4.1×10(14) W/cm(2).

Design of ridge filters for spread-out Bragg peaks with Monte Carlo simulation in carbon ion therapy.

Spread-out Bragg peaks made by ridge filters or wheel range modulators are used in charged particle therapy with passive methods to achieve uniform biological responses in irradiated tumors. Following the biological responses needed to design the ridge filters, which were developed at the National Institute of Radiological Sciences in Japan, new ridge filters were designed using recent developments in heavy-ion reactions and dosimetry. The Monte Carlo code of Geant4 was used to calculate the qualities of carbon ion beams in a water phantom. The results obtained from the simulation were corrected so that they agreed with the measurements of depth dose distributions. The calculations of biological responses to fragments other than carbon ions were assumed to be for helium ions. The measured dose distributions with the designed ridge filters were compared to the calculated distributions. A beam modifying system using this adaptable method was successively applied to carbon ion therapy at Gunma University.

RORγt-dependent IL-17A-producing cells in the pathogenesis of intestinal inflammation.

The hypothesis of helper T (T(h))1/T(h)2 cytokine balance proposed by Mosmann and Coffman is often invoked to explain the development of inflammatory diseases, including inflammatory bowel diseases (IBD). Recently, however, a newly identified class of T(h) cells-T(h)17 cells, which produce T(h)17 family cytokines-has been recognized as an essential subpopulation in the development of almost all kinds of human and animal inflammatory diseases, rather than T(h)1 and T(h)2 cells. A representative T(h)17 family cytokine, interleukin (IL)-17A, is produced by not only T(h)17 cells, but also by other types of cells, such as T-cell receptor γδ T cells, natural killer (NK) T cells, NK cells, myeloid cells, and innate lymphoid cells, which may also be critically involved in the initiation and persistence of IBD. Here we review recent advances in the study of such IL-17A-producing cells in the pathogenesis of IBD.

Intracellular bacteria recognition contributes to maximal interleukin (IL)-12 production by IL-10-deficient macrophages.

Interleukin (IL)-12 is a key factor that induces T helper cell type 1-mediated immunity and inflammatory diseases. In some colitis models, such as IL-10 knock-out (KO) mice, IL-12 triggers intestinal inflammation. An abundant amount of IL-12 is produced by intestinal macrophages in response to stimulation by commensal bacteria in IL-10 KO mice. Intact bacteria are more potent inducers of macrophage IL-12 production than cell surface components in this model. This suggested that cell surface receptor signalling and intracellular pathogen recognition mechanisms are important for the induction of IL-12. We addressed the importance of intracellular recognition mechanisms and demonstrated that signal transducers and activator of transcription 1 (STAT1) signalling activated bacterial phagocytosis and was involved in the induction of abnormal IL-12 production. In IL-10 KO mouse bone marrow-derived (BM) macrophages, Escherichia coli stimulation induced increased IL-12p70 production compared to lipopolysaccharide combined with interferon (IFN)-γ treatment. Significant repression of IL-12 production was achieved by inhibition of phagocytosis with cytochalasin D, and inhibition of de novo protein synthesis with cycloheximide. Induction of IFN regulatory factors-1 and -8, downstream molecules of STAT1 and the key transcription factors for IK-12 transcription, following E. coli stimulation, were mediated by phagocytosis. Interestingly, STAT1 was activated after stimulation with E. coli in IL-10 KO BM macrophages, although IFN-γ could not be detected. These data suggest that molecules other than IFN-γ are involved in hyper-production mechanisms of IL-12 induced by E. coli stimulation. In conclusion, enteric bacteria stimulate excessive IL-12p70 production in IL-10 KO BM macrophages via phagocytosis-dependent signalling.

Characteristics of paediatric patients with 2009 pandemic influenza A(H1N1) and severe, oxygen-requiring pneumonia in the Tokyo region, 1 September-31 October 2009.

Few reports describe the features of 2009 pandemic influenza A(H1N1) pneumonia in children. We retrospectively reviewed 21 consecutive children admitted to hospital from September to October 2009 in the Tokyo region. The diagnosis of 2009 pandemic influenza A(H1N1) virus infection was based on positive results of real-time RT-PCR or rapid influenza antigen test. All patients were hospitalised for pneumonia with respiratory failure and severe hypoxia. The median interval from onset of influenza symptoms to admission was 14 hours (range: 5-72 hours) and the median interval from the onset of fever (≥38 degrees C) to hospitalisation was 8.5 hours (range: 0-36 hours). All patients required oxygen inhalation. Four patients required mechanical ventilation. Chest radiography revealed patchy infiltration or atelectasis in all patients. Antiviral agents and antibiotics were administrated to all patients. Antiviral agents were administered to 20 patients within 48 hours of influenza symptom onset. No deaths occurred during the study period. Paediatric patients with this pneumonia showed rapid aggravation of dyspnoea and hypoxia after the onset of influenza symptoms.

1.2 mJ sub-4-fs source at 1 kHz from an ionizing gas.

We demonstrate a 1.2 mJ, 3.8 fs, carrier-envelope phase-controlled laser source by novel energy-scalable spectral broadening in an ionizing gas medium, which is widely applicable to sub-10-fs multimillijoule laser systems to obtain sub-2-cycle (<4 fs) multi-millijoule pulses.

The compact electron cyclotron resonance ion source KeiGM for the carbon ion therapy facility at Gunma University.

A high-energy carbon-ion radiotherapy facility is under construction at Gunma University Heavy Ion Medical Centre (GHMC). Its design was based on a study of the heavy ion radiotherapy at the National Institute of Radiological Sciences (NIRS) in order to reduce the size and construction cost of the facility. A compact electron cyclotron resonance ion source (ECRIS) for Gunma University, called KeiGM, was installed in 2008. It is almost a copy of the prototype ECRIS Kei2 which was developed by NIRS; meanwhile this prototype produced over 1 e mA of C(4+) using C(2)H(2) gas (660 W and 40 kV). The beam intensity of C(4+) was 600 e microA with CH(4) gas (250 W and 30 kV). The beam intensity satisfies the required value of 300 e microA.

Carbon-ion radiotherapy: clinical aspects and related dosimetry.

The features of relativistic carbon-ion beams are attractive from the viewpoint of radiotherapy. They exhibit not only a superior physical dose distribution but also an increase in biological efficiency with depth, because energy loss of the beams increases as they penetrate the body. This paper reviews clinical aspects of carbon-beam radiotherapy using the experience at the National Institute of Radiological Sciences. The paper also outlines the dosimetry related to carbon-beam radiotherapy, including absolute dosimetry of the carbon beam, neutron measurements and radiation protection measurements.