Yuki Matsui

Secondary neutron ambient dose equivalents per the treatment absorbed dose in passive carbon-ion and proton radiotherapies were measured using a rem meter, WENDI-II at two carbon-ion radiotherapy facilities and four proton radiotherapy facilities in Japan. Our measured results showed that (1) neutron ambient dose equivalent in carbon-ion radiotherapy is lower than that in proton radiotherapy, and (2) the difference to the measured neutron ambient dose equivalents among the facilities is within a factor of 3 depending on the operational beam setting used at the facility and the arrangement of the beam line, regardless of the method for making a laterally uniform irradiation field: the double scattering method or the single-ring wobbling method. The reoptimization of the beam line in passive particle radiotherapy is an effective way to reduce the risk of secondary cancer because installing an adjustable precollimator and designing the beam line devices with consideration of their material, thickness and location, etc., can significantly reduce the neutron exposure. It was also found that the neutron ambient dose equivalent in passive particle radiotherapy is equal to or less than that in the photon radiotherapy. This result means that not only scanning particle radiotherapy but also passive particle radiotherapy can provide reduced exposure to normal tissues around the target volume without an accompanied increase in total body dose.

In order to undertake a quantitative evaluation of balance occlusal load, the use of the Dental Prescale System was investigated. The method uses a test sheet that undergoes a colour-developing chemical reaction, for detecting contact area, and a computerized analysis system, for evaluating the balance of occlusal load. Twenty natural dentate subjects and 10 hemimaxillectomy patients participated in the study. Each subject bit a test sheet as hard as possible for 3 s. The balance of occlusal load was expressed as a percentage of the load on the side with the lesser occlusive load (%OLR). The %OLR ranged from 39.7% to 49.4% in the natural dentate subjects, and from 0% to 31.3% in the hemimaxillectomy patients at their resection site. The patients' low %OLRs were attributed to loss of sustaining structure and subjective occlusal adjustment by clinicians. Combining technical simplicity, relatively high reproducibility, and diverse analysis capability, this system is useful for quantitative evaluation of balance of occlusal load in clinical situations.

Background: The M-type phospholipase A2 receptor (PLA2R) and thrombospondin type-1 domain-containing 7A (THSD7A) were identified as intrinsic antigens in primary membranous nephropathy (MN). Complement activation via the lectin pathway in intrinsic antigen-related MN is still unclear. Methods: We retrospectively enrolled 60 primary Japanese MN patients and detected activated complement pathways by staining complement proteins in glomerular deposition. According to the findings of PLA2R and THSD7A staining in glomeruli, they were classified into intrinsic antigen-related or -unrelated MN. We evaluated clinicopathological characteristics and predictors of clinical outcomes in intrinsic antigen-related MN. Results: Thirty-nine (65%) patients had PLA2R in glomerular deposits and two (3.3%) patients had THSD7A. One of them had both PLA2R and THSD7A (double positive). Forty patients were classified into the intrinsic antigen-related group. The other 20 patients were negative for both antigens (unrelated group). The prevalence and staining intensity of mannose-binding lectin (MBL) deposits were much higher in the intrinsic antigen-related group [55% versus 20%, P < 0.010, 1.0 (interquartile range 1.0-2.0) versus 1.0 (0.0-1.0), P = 0.01, respectively]. The staining intensity of MBL in glomeruli also correlated with the IgG4 staining intensity. In intrinsic antigen-related MN, MBL staining intensity was an unfavorable predictor for remission of proteinuria [hazard ratio (HR) 0.40, P < 0.01] and renal dysfunction (HR 3.81, P = 0.01) in Cox proportional hazards analysis. Moreover, the glomerular MBL-positive group showed more severe interstitial fibrosis and worse clinical outcomes. Conclusions: Intrinsic antigen-related MN was more strongly associated with complement activation by the lectin pathway, which may contribute to a less favorable clinical outcome.

BACKGROUND: Discontinuation of antipsychotics predisposes patients with remitted/stable first-episode psychosis (FEP) to a higher risk of relapse, but it remains unclear how long discontinuation increases the relapse rate in these patients compared with maintenance. METHODS: This meta-analysis of randomized controlled trials (RCTs) compared relapse rates in FEP patients between antipsychotic treatment discontinuation and maintenance groups at 1, 2, 3, 6, 9, 12 (primary), and 18-24 months. The risk ratio (RR) and numbers needed to treat/harm (NNT/NNH) were calculated using a random-effects model. RESULTS: Ten RCTs were identified (n = 776; mean study duration, 18.6 ± 6.0 months). The antipsychotics were discontinued abruptly in four RCTs (which reported data only at 12 months) and after tapering off gradually over several months (mean length, 3 months) in six RCTs. Compared with the discontinuation group, the maintenance group experienced significantly fewer relapses at all time points except 1 month [RR (NNT): 2 months, 0.49 (13); 3 months, 0.46 (9); 6 months, 0.55 (6); 9 months, 0.48 (3); 12 months, 0.47 (3); and 18-24 months, 0.57 (4)]. The maintenance group was associated with higher discontinuation due to adverse events (RR, 2.61; NNH, not significant). CONCLUSIONS: Maintaining antipsychotic treatment prevented relapse for up to 24 months in FEP patients. Discontinuation of antipsychotics for ⩾2 months significantly increased the risk of relapse. However, 45.7% of patients who discontinued antipsychotics for 12 months (39.4% after 18-24 months) did not experience a relapse.