Imaging assessment of photosensitizer emission induced by radionuclide-derived Cherenkov radiation using charge-coupled device optical imaging and long-pass filters

BACKGROUND

Radionuclides produce Cherenkov radiation (CR), which can potentially activate photosensitizers (PSs) in phototherapy. Several groups have studied Cherenkov energy transfer to PSs using optical imaging; however, cost-effectively identifying whether PSs are excited by radionuclide-derived CR and detecting fluorescence emission from excited PSs remain a challenge. Many laboratories face the need for expensive dedicated equipment.

AIM

To cost-effectively confirm whether PSs are excited by radionuclide-derived CR and distinguish fluorescence emission from excited PSs.

METHODS

The absorbance and fluorescence spectra of PSs were measured using a microplate reader and fluorescence spectrometer to examine the photo-physical properties of PSs. To mitigate the need for expensive dedicated equipment and achieve the aim of the study, we developed a method that utilizes a charge-coupled device optical imaging system and appropriate long-pass filters of different wavelengths (manual sequential application of long-pass filters of 515, 580, 645, 700, 750, and 800 nm). Tetrakis (4-carboxyphenyl) porphyrin (TCPP) was utilized as a model PS. Different doses of copper-64 (64CuCl2) (4, 2, and 1 mCi) were used as CR-producing radionuclides. Imaging and data acquisition were performed 0.5 h after sample preparation. Differential image analysis was conducted by using ImageJ software (National Institutes of Health) to visually evaluate TCPP fluorescence.

RESULTS

The maximum absorbance of TCPP was at 390-430 nm, and the emission peak was at 670 nm. The CR and CR-induced TCPP emissions were observed using the optical imaging system and the high-transmittance long-pass filters described above. The emission spectra of TCPP with a peak in the 645-700 nm window were obtained by calculation and subtraction based on the serial signal intensity (total flux) difference between 64CuCl2 + TCPP and 64CuCl2. Moreover, the differential fluorescence images of TCPP were obtained by subtracting the 64CuCl2 image from the 64CuCl2 + TCPP image. The experimental results considering different 64CuCl2 doses showed a dose-dependent trend. These results demonstrate that a bioluminescence imaging device coupled with different long-pass filters and subtraction image processing can confirm the emission spectra and differential fluorescence images of CR-induced TCPP.

CONCLUSION

This simple method identifies the PS fluorescence emission generated by radionuclide-derived CR and can contribute to accelerating the development of Cherenkov energy transfer imaging and the discovery of new PSs.

Response of personal dosemeters on various age-specific anthropometric phantoms under external irradiation applied to areas affected by the 2011 Fukushima Daiichi nuclear accident

We experimentally obtained the responses of two personal dosemeters (PDs, D-shuttle and Dose-i) attached on five age-specific phantoms under rotational irradiation geometry, which simulated an environment that was radiologically affected by the 2011 Fukushima nuclear accident using of a 137Cs source. Although the PD responses showed an angular phase shift by the PD position on the phantoms, the angular dependence was small when the contamination was widely distributed. The PD responses decreased as much as ~10% with the increase in the phantoms' body size. Although there were ~17% variations in the PD/ADE (ambient dose equivalent) ratio depending on the different PDs, this variation was due to the fact that D-shuttle was calibrated with the inclusion of a safety margin. The PD/ADE ratios were similar to the effective dose to ADE ratios for corresponding age-specific phantoms. Our results suggest that these two PDs can provide reasonable estimates for age-dependent effective doses.

Search for the Majorana Nature of Neutrinos in the Inverted Mass Ordering Region with KamLAND-Zen

The KamLAND-Zen experiment has provided stringent constraints on the neutrinoless double-beta (0νββ) decay half-life in ^{136}Xe using a xenon-loaded liquid scintillator. We report an improved search using an upgraded detector with almost double the amount of xenon and an ultralow radioactivity container, corresponding to an exposure of 970 kg yr of ^{136}Xe. These new data provide valuable insight into backgrounds, especially from cosmic muon spallation of xenon, and have required the use of novel background rejection techniques. We obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>2.3×10^{26}  yr at 90% C.L., corresponding to upper limits on the effective Majorana neutrino mass of 36-156 meV using commonly adopted nuclear matrix element calculations.

Impact of small-airway disease on exercise intolerance and long-term outcomes in patients with heart failure and reduced or preserved ejection fraction

Introduction

Exercise intolerance in patients with heart failure (HF) is a strong indicator of a poor prognosis. As the respiratory impairment in HF patients, the small airway is reportedly more susceptible than central airways, which results in increased airway resistance and may cause poor outcomes. However, the impact of small-airway disease (SAD) on exercise intolerance and prognosis in patients with HF is still unclear.

Purpose

We investigated the associations between SAD and exercise intolerance in patients with HF, and the clinical significance of SAD for long-term clinical events with a reduced or preserved ejection fraction.

Methods

We reviewed 1015 patients with HF (mean age, 66.9±14.6 years; male, 64.5%) admitted for medical treatment. Patients with a prior history of chronic respiratory disease or an obstructive lung pattern – defined as the forced expiratory volume (%) in 1 s relative to <70% forced vital capacity using spirometry – were excluded. Characteristics including HF aetiology, comorbidities conditions, medications, blood parameters, and echocardiographic variables were obtained from clinical records. All patients underwent spirometry at hospital discharge, and SAD was defined as the maximum mid-expiratory flow (%) relative to a <60% predicted value. At hospital discharge, we measured 6-min walk distance (6MWD), and <300 m was considered as exercise intolerance. The primary endpoint was a composite clinical event of all-cause death and/or unplanned readmission for HF. Multivariate logistic regression analysis was used to assess the association between SAD and exercise intolerance. The multivariate Cox proportional hazard model was used to clarify whether SAD was an independent predictor for the incidence of clinical events. We also performed subgroup analyses in each multivariate analysis based on a left ventricular ejection fraction (LVEF) of 40%.

Result

SAD was observed in 479 (47.2%) patients. LVEF subgroups included 458 (45.1%) and 518 (51.0%) patients with LVEF <40% and ≥40%, respectively. After adjusting for clinical characteristics, SAD was independently associated with 6MWD <300 m (Figure 1). Moreover, this association was consistently observed in the LVEF <40% and ≥40% (Figure 1). During the median follow-up period of 1.5 years, all-cause death/readmission occurred in 431 patients (42.5%), and the incidence rate was 17.5/100 person-years. In the multivariate Cox proportional hazard model, SAD was independently associated with lower event-free survival rates in all patients and the LVEF <40% subgroup, but not LVEF ≥40% subgroup (Figure 2A, B, and C, respectively).

Conclusion

This study is the first to reveal that SAD is associated with exercise intolerance in patients with HF regardless of LVEF. Moreover, SAD may have a predictive significance for long-term outcomes in patients with HF and subgroups with reduced, but not preserved ejection fraction.

Funding Acknowledgement

Type of funding sources: None.

Radiotheranostic Agent 64Cu-cyclam-RAFT-c(-RGDfK-)4 for Management of Peritoneal Metastasis in Ovarian Cancer

PURPOSE

Ovarian cancer peritoneal metastases (OCPMs) are a pathophysiologically heterogeneous group of tumors that are rarely curable. α_Vβ₃ integrin (α_Vβ₃) is overexpressed on tumoral neovessels and frequently on ovarian cancer cells. Here, using two clinically relevant α_Vβ₃-positive OCPM mouse models, we studied the theranostic potential of an α_Vβ₃-specific radiopeptide, ⁶⁴Cu-cyclam-RAFT-c(-RGDfK-)₄ (⁶⁴Cu-RaftRGD), and its intra- and intertumoral distribution in relation to the tumor microenvironment.

EXPERIMENTAL DESIGN

α_Vβ₃-expressing peritoneal and subcutaneous models of ovarian carcinoma (IGR-OV1 and NIH:OVCAR-3) were established in nude mice. ⁶⁴Cu-RaftRGD was administered either intravenously or intraperitoneally. We performed intratumoral distribution (ITD) studies, PET/CT imaging and quantification, biodistribution assay and radiation dosimetry, and therapeutic efficacy and toxicity studies.

RESULTS

Intraperitoneal administration was an efficient route for targeting ⁶⁴Cu-RaftRGD to OCPMs with excellent tumor penetration. Using the fluorescence surrogate, Cy5.5-RaftRGD, in our unique high-resolution multifluorescence analysis, we found that the ITD of ⁶⁴Cu-RaftRGD was spatially distinct from, but complementary to, that of hypoxia. ⁶⁴Cu-RaftRGD-based PET enabled clear visualization of multiple OCPM deposits and ascites and biodistribution analysis demonstrated an inverse correlation between tumor uptake and tumor size (1.2-17.2 mm). ⁶⁴Cu-RaftRGD at a radiotherapeutic dose (148 MBq/0.357 nmol) showed antitumor activities by inhibiting tumor cell proliferation and inducing apoptosis, with negligible toxicity.

CONCLUSIONS

Collectively, these results demonstrate the all-in-one potential of ⁶⁴Cu-RaftRGD for imaging guided radiotherapy of OCPM by targeting both tumoral neovessels and cancerous cells. On the basis of the ITD finding, we propose that pairing α_Vβ₃- and hypoxia-targeted radiotherapies could improve therapeutic efficacy by overcoming the heterogeneity of ITD encountered with single-agent treatments.

Precision Analysis of the ^{136}Xe Two-Neutrino ββ Spectrum in KamLAND-Zen and Its Impact on the Quenching of Nuclear Matrix Elements

We present a precision analysis of the ^{136}Xe two-neutrino ββ electron spectrum above 0.8 MeV, based on high-statistics data obtained with the KamLAND-Zen experiment. An improved formalism for the two-neutrino ββ rate allows us to measure the ratio of the leading and subleading 2νββ nuclear matrix elements (NMEs), ξ_{31}^{2ν}=-0.26_{-0.25}^{+0.31}. Theoretical predictions from the nuclear shell model and the majority of the quasiparticle random-phase approximation (QRPA) calculations are consistent with the experimental limit. However, part of the ξ_{31}^{2ν} range allowed by the QRPA is excluded by the present measurement at the 90% confidence level. Our analysis reveals that predicted ξ_{31}^{2ν} values are sensitive to the quenching of NMEs and the competing contributions from low- and high-energy states in the intermediate nucleus. Because these aspects are also at play in neutrinoless ββ decay, ξ_{31}^{2ν} provides new insights toward reliable neutrinoless ββ NMEs.

VALIDATION OF MONTE CARLO DOSE CALCULATION FOR PAEDIATRIC CT EXAMINATIONS USING TUBE CURRENT MODULATION BASED ON IN-PHANTOM DOSIMETRY

The aim of this study is to estimate tube current modulation (TCM) profiles in paediatric computed tomography (CT) examinations with a TCM scheme (Volume-EC) and evaluate the estimation accuracy of TCM profiles. Another aim is to validate organ doses calculated using Monte Carlo-based CT dosimetry software and estimated TCM profiles by comparing them with those measured using 5-year-old and 10-year-old anthropomorphic phantoms and radio-photoluminescence glass dosemeters. Dose calculations were performed by inputting detailed descriptions of a CT scanner, scan parameters and CT images of the phantoms into the software. Organ doses were evaluated from the calculated dose distribution images. Average relative differences (RDs) between the estimated and actual TCM profiles ranged from -3.6 to 5.6%. RDs between the calculated and measured organ doses ranged from -4.2 to 13.0% and -18.1 to 4.9% for 5-year-old and 10-year-old phantoms, respectively. These results validate dose calculations for paediatric CT scans using TCM.

Organ Dose Evaluations Based on Monte Carlo Simulation for CT Examinations Using Tube Current Modulation

The aims of this study were to estimate tube current values for each X-ray projection angle used in adult chest computed tomography (CT) and abdomen-pelvis CT examinations with tube current modulation (TCM) and to validate organ doses determined using Monte Carlo (MC) simulations through comparisons with the doses measured using in-phantom dosimetry. For dose simulations, dose distribution images were obtained by inputting the geometry of a CT scanner, scan parameters including estimated TCM curves and CT images of an adult anthropomorphic phantom into MC simulation software. Organ doses were then determined from the dose distribution images. For dose measurements, organ doses were evaluated using radio-photoluminescence glass dosemeters located at various organ positions within the phantom. Relative differences between the simulated and measured organ doses were -2.5 to 11.0% and -1.5 to 10.5% for organs in chest and abdomen-pelvis CT scan ranges, respectively. Thus, the simulated and measured doses agreed well.

DEVELOPMENT OF AGE-SPECIFIC JAPANESE PHYSICAL PHANTOMS FOR DOSE EVALUATION IN INFANT CT EXAMINATIONS

Secondary to the previous development of age-specific Japanese head phantoms, the authors designed Japanese torso phantoms for dose assessment in infant computed tomography (CT) examinations and completed a Japanese 3-y-old head-torso phantom. For design of age-specific torso phantoms (0, 0.5, 1 and 3 y old), anatomical structures were measured from CT images of Japanese infant patients. From the CT morphometry, it was found that rib cages of Japanese infants were smaller than those in Europeans and Americans. Radiophotoluminescence glass dosemeters were used for dose measurement of a 3-y-old head-torso phantom. To examine the validity of the developed phantom, organ and effective doses by the in-phantom dosimetry system were compared with simulation values in a web-based CT dose calculation system (WAZA-ARI). The differences in doses between the two systems were <20 % at the doses of organs within scan regions and effective doses in head, chest and abdominopelvic CT examinations.

Publisher's Note: Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen [Phys. Rev. Lett. 117, 082503 (2016)]

This corrects the article DOI: 10.1103/PhysRevLett.117.082503.

Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen

We present an improved search for neutrinoless double-beta (0νββ) decay of ^{136}Xe in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the ^{110m}Ag contaminant identified in previous searches. Combining the results from the first and second phase, we obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>1.07×10^{26}  yr at 90% C.L., an almost sixfold improvement over previous limits. Using commonly adopted nuclear matrix element calculations, the corresponding upper limits on the effective Majorana neutrino mass are in the range 61-165 meV. For the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region.

Estimation of organ doses and effective doses in image-guided respiration-gated radiotherapy

Dose conformity in thoracic and abdominal ion-beam radiotherapy is degraded by respiratory motion. To improve conformity, an image-guided respiration-gated system can be used in the treatment room. The purpose of this study was to estimate the organ doses and effective doses to patients from an image-guided respiration-gated system. Glass dosemeters were inserted into an adult anthropomorphic phantom and were attached to the surface on the phantom. The phantom was placed on the treatment couch, and the imaging dose from fluoroscopy was evaluated. In addition to the organ doses, the effective doses were also estimated according to the ICRP Publication 103. The irradiation time is over 3-5 min per beam angle. When image acquisition conditions were assumed for thoracic treatment, the effective doses and maximal skin doses were 0.48-0.79 mSv and 5.9-9.9 mGy, respectively. The estimated doses can be the base data for considering radiological protection in the radiotherapy.

Optimised paediatric CT dose at a tertiary children's hospital in Japan: a 4-y single-centre analysis

Since diagnostic reference levels (DRLs) for children are not currently established in Japan, the authors determined local DRLs for the full range of paediatric CT examinations in a single tertiary care children's hospital. A retrospective review of 4801 CT performance records for paediatric patients (<15 y old) who had undergone CT examinations from 2008 to 2011 was conducted. The most frequent examinations were of the head (52 %), followed by cardiac (15 %), temporal bone (9 %), abdomen (7 %), chest (6 %) and others (11 %). Approximately one-third of children received two or more CT scans. The authors' investigation showed that mean CTDIvol and DLP for head, chest and abdomen increased as a function of age. Benchmarking of the results showed that CTDIvol, DLP and effective dose for chest and abdomen examinations in this hospital were below average, whereas those for the head tended to be at or slightly above average of established DRL values from five countries. The results suggest that CT examinations as performed in a tertiary children's hospital in Japan are well optimised.

Evaluation of organ doses in adult and paediatric CT examinations based on Monte Carlo simulations and in-phantom dosimetry

The aim of this study was to validate the computed tomography dose index (CTDI) and organ doses evaluated by Monte Carlo simulations through comparisons with doses evaluated by in-phantom dosimetry. Organ doses were measured with radio-photoluminescence glass dosemeter (RGD) set at various organ positions within adult and 1-y-old anthropomorphic phantoms. For the dose simulations, the X-ray spectrum and bow-tie filter shape of a CT scanner were estimated and 3D voxelised data of the CTDI and anthropomorphic phantoms from the acquired CT images were derived. Organ dose simulations and measurements were performed with chest and abdomen-pelvis CT examination scan parameters. Relative differences between the simulated and measured doses were within 5 % for the volume CTDI and 13 % for organ doses for organs within the scan range in adult and paediatric CT examinations. The simulation results were considered to be in good agreement with the measured doses.

Estimation of absorbed radiation dose rates in wild rodents inhabiting a site severely contaminated by the Fukushima Dai-ichi nuclear power plant accident

The dose rates of radiation absorbed by wild rodents inhabiting a site severely contaminated by the Fukushima Dai-ichi Nuclear Power Plant accident were estimated. The large Japanese field mouse (Apodemus speciosus), also called the wood mouse, was the major rodent species captured in the sampling area, although other species of rodents, such as small field mice (Apodemus argenteus) and Japanese grass voles (Microtus montebelli), were also collected. The external exposure of rodents calculated from the activity concentrations of radiocesium ((134)Cs and (137)Cs) in litter and soil samples using the ERICA (Environmental Risk from Ionizing Contaminants: Assessment and Management) tool under the assumption that radionuclides existed as the infinite plane isotropic source was almost the same as those measured directly with glass dosimeters embedded in rodent abdomens. Our findings suggest that the ERICA tool is useful for estimating external dose rates to small animals inhabiting forest floors; however, the estimated dose rates showed large standard deviations. This could be an indication of the inhomogeneous distribution of radionuclides in the sampled litter and soil. There was a 50-fold difference between minimum and maximum whole-body activity concentrations measured in rodents at the time of capture. The radionuclides retained in rodents after capture decreased exponentially over time. Regression equations indicated that the biological half-life of radiocesium after capture was 3.31 d. At the time of capture, the lowest activity concentration was measured in the lung and was approximately half of the highest concentration measured in the mixture of muscle and bone. The average internal absorbed dose rate was markedly smaller than the average external dose rate (<10% of the total absorbed dose rate). The average total absorbed dose rate to wild rodents inhabiting the sampling area was estimated to be approximately 52 μGy h(-1) (1.2 mGy d(-1)), even 3 years after the accident. This dose rate exceeds 0.1-1 mGy d(-1) derived consideration reference level for Reference rat proposed by the International Commission on Radiological Protection (ICRP).

Development of age-specific Japanese head phantoms for dose evaluation in paediatric head CT examinations

In this study, the authors developed age-specific physical head phantoms simulating the physique of Japanese children for dose evaluation in paediatric head computed tomography (CT) examinations. Anatomical structures at 99 places in 0-, 0.5-, 1- and 3-y-old Japanese patients were measured using DICOM viewer software from CT images, and the head phantom of each age was designed. For trial manufacture, a 3-y-old head phantom consisting of acrylic resin and gypsum was produced by machine processing. Radiation doses for the head phantom were measured with radiophotoluminescence glass dosemeters and Si-pin photodiode dosemeters. To investigate whether the phantom shape was suitable for dose evaluation, organ doses in the same scan protocol were compared between the 3-y-old head and commercially available anthropomorphic phantoms having approximately the same head size. The doses of organs in both phantoms were equivalent. The authors' designed paediatric head phantom will be useful for dose evaluation in paediatric head CT examinations.

Induced radioactive nuclides of 10-MeV radiotherapy accelerators detected by using a portable HP-Ge survey meter

The radioactivation of linear accelerator components for radiation therapy is interest for radiation protection in general, and particularly, when decommissioning these structures. The energy spectra of gamma rays emitted from the heads of two accelerator models, EXL-15SP and Clinac iX, after 10-MeV X-ray irradiation, were measured using a high-purity germanium semiconductor survey meter. After spectrum analyses, activities of (24)Na, (28)Al, (54)Mn, (56)Mn, (57)Ni, (58)Co, (60)Co, (64)Cu, (65)Zn, (122)Sb, (124)Sb, (181)W, (187)W, (196)Au, and (198)Au were detected. One centimetre deep dose-equivalent rate of the heads of the linear accelerator was measured using the survey meter. The dose rate decreased to ∼10 % of its initial rate after 1 week. Long-term activations were few, the radioactivity level was low, and a cooling time of several days was effective for reducing dose rate to an acceptable level for decommissioning.

Photoexcitation of K-shell and L-shell hollow beryllium

We have observed K-shell and L-shell hollow beryllium atoms (2s(2)2p3s and 1s3s(2)3p) created by photoexcitation using synchrotron radiation. Resonance shapes were fitted to the Fano profile and the parameters were deduced. A Dirac-Fock calculation was performed to identify the configuration of the peaks and to predict other hollow atomic peaks. The results of the calculation were in good agreement with the experimental data. The comparison of the transition strength has revealed that the three-electron photoexcitation to the 1s3s(2)3p configuration is stronger than the two-electron photoexcitation to the 2s(2)2p3s configuration. This is attributed to the large overlap between the 2s orbital of the ground state (1s(2)2s(2)) with the orbital of the L-shell hollow state (1s3s(2)3p).

Monitoring of T-cell repertoire was useful for predicting graft-versus-host disease prognosis in a patient with chronic myelogeneous leukemia after allogeneic bone marrow transplantation

We analyzed 24 T-cell receptor (TCR)beta chain subfamilies (Vbeta) and the chimerism of a patient with chronic myelogeneous leukemia who underwent allogeneic bone marrow transplantation (allo-BMT). The patient developed liver dysfunction at day 19 leading to worsening of his condition. He died on day 91 of hepatic failure. Complete donor chimerism was observed after day 19. The average complexity score of TCR-Vbeta, which was low on day 19 (5.50), because much lower on day 82 (3.77). The average value of normal volunteers is 7.69. Neither immunosuppressive therapy nor antiviral therapy was effective to treat his hepatic dysfunction. A liver specimen at autopsy showed necrotic tissue with invasion of lymphocytes under the endothelial cells of the bile ducts. These findings suggest that the liver dysfunction was due to graft-versus-host disease (GVHD). Careful monitoring of chimerism and TCR-Vbeta complexity may help to predict the prognosis of GVHD after allogeneic BMT.

Successful non-T-cell-depleted nonmyeloablative hematopoietic stem cell transplantation (NST) from an HLA-haploidentical 2-loci-mismatched sibling in a heavily transfused patient with severe aplastic anemia based on the fetomaternal microchimerism

A 37-year-old Japanese man with systemic hemochromatosis due to multiple transfusions was referred to us for the treatment of severe aplastic anemia (SAA), from which he had been suffering for 24 years. The patient had diabetes arising from the hemochromatosis, chronic anal fissures, and a kidney abscess due to neutropenia. He was treated with a nonmyeloablative preconditioning regimen followed by non-T-cell-depleted (non-TCD) allogeneic peripheral blood stem cell transplantation (PBSCT) from his human leukocyte antigen (HLA)-haploidentical 2-loci-mismatched sibling. Prompt engraftment of granulocytes and platelets was observed, and graft-versus-host disease was easy to control. Noninherited maternal antigens in the donor were confirmed prior to PBSCT, and they were also detected in small quantities in the recipient. This report describes the first successful nonmyeloablative hematopoietic stem cell transplant in a heavily transfused SAA patient from an HLA-haploidentical 2-loci-mismatched sibling donor. The result suggests that a long-term fetomaternal microchimerism-positive sibling can be a second-line donor if an alternative HLA-identical donor is not available.

Possible efficacy of lamivudine treatment to prevent hepatitis B virus reactivation due to rituximab therapy in a patient with non-Hodgkin's lymphoma

We used regimens containing rituximab in the treatment of five hepatitis B virus surface antibody (HBsAb)-positive patients with non-Hodgkin's lymphoma (NHL). Serum levels of HBsAb were obtained and analyzed in four of these patients. Two patients were HBs antigen (HBsAg) positive. One of these HBsAg-positive patients was treated with lamivudine because the patient developed fulminant hepatitis from hepatitis B virus (HBV) infection prior to chemotherapy. However, none of the other patients were administered lamivudine. An HBsAg-positive patient who did not receive lamivudine treatment later developed fulminant hepatitis. Another HBsAg-positive patient receiving lamivudine prophylaxis did not develop severe hepatitis arising from HBV. In the three patients not receiving lamivudine treatment, serum HBsAb titers decreased soon after the administration of rituximab. These results suggest that rituximab reduced the antibody titer for HBV, thus inducing an immunological environment leading to easy reactivation of HBV. Lamivudine prophylaxis was effective, at least when rituximab was given to an HBsAg-positive patient with non-Hodgkin's lymphoma.

Double photoexcitation of helium in a strong dc electric field

We report the first experimental measurements of the effect of an applied field on the photoexcitation and autoionization of doubly excited states of helium. Ground-state photoionization spectra have been measured in the region below the He+(N=2) threshold with static electric fields of up to 84.4 kV/cm across the interaction region. The results are compared to the theoretical calculations of Chung et al. [J. Phys. B 34, 165 (2001)]], which are the only calculations available in this regime. Transitions to several states in the N=2, n=6 manifold are assigned, and a wealth of new structure is observed. Our data show that many more series are mixed in by the field than those predicted by theory.

Treatment modalities for oral verrucous carcinomas and their outcomes: contribution of radiotherapy and chemotherapy

BACKGROUND

This clinical study focused, firstly, on the results of treatment and, secondly, on the anaplastic transformation, of oral verrucous carcinomas (OVCs) diagnosed and treated from 1981 to 1997 at the Department of Oral and Maxillofacial Surgery at Shimane Medical University Hospital.

METHODS

We analyzed the treatment modalities and outcomes for 15 patients with OVC.

RESULTS

Excluding the results for 4 palliatively treated patients, the disease-free survival rates of the patients after the initial treatments, were 82% at 5 years and 66% at 10 years; for all 15 patients, these rates were 57% and 46%, respectively. Surgery alone and surgery combined with other treatments (such as radiotherapy and chemotherapy) appeared to yield disease-free survival rates to those achieved superior with other treatments whether single or combined; (78% vs 33% for 5-year disease-free survival; 52% vs 33% for 10-year disease-free survival); however, the difference was not significant (P = 0.47). Well differentiated squamous cell carcinomas (W-SCCs) (n = 5) as well as spindle cell carcinoma (n = 1) were found in subsequent operative or biopsy specimens.

CONCLUSION

Surgery was the most reliable treatment method for OVC; however, radiotherapy combined with chemotherapy was the next most preferable treatment when surgery was not undertaken. We also found that highly malignant transformation (anaplastic transformation) occasionally occurred during treatments for OVC.

Anandamide induces apoptosis of PC-12 cells: involvement of superoxide and caspase-3

Anandamide (arachidonoylethanolamide), an endogenous cannabinoid receptor ligand has been suggested to have physiological role in mammalian nervous system. However, little is known about the role of anandamide on neuronal cells. Here, we demonstrate that anandamide causes death of PC-12 cells, showing marked DNA condensation and fragmentation, appearance of cells at sub-G(0)/G(1) and redistribution of phosphatidyl serine, the hallmark features of apoptosis. Anandamide raised intracellular superoxide level and CPP32-like protease activity in PC-12 cells markedly. Furthermore, antioxidant N-acetyl cysteine prevented anandamide-induced superoxide anion formation and cell death, implying that intracellular superoxide is a novel mediator of anandamide-induced apoptosis of PC-12 cells.

The effect of trihexyphenidyl, an anticholinergic agent, on regional cerebral blood flow and oxygen metabolism in patients with Parkinson's disease

Cerebral blood flow and oxygen metabolism were studied in six previously untreated patients with Parkinson's disease (PD) before and after anticholinergic treatment using positron emission tomography (PET) and compared with six controls. The PET study and an assessment of the disability and cognitive impairment were performed before and after administration of 6 mg trihexyphenidyl for 5 to 11 weeks. All PD patients showed improvements in motor symptoms after the trihexyphenidyl treatment. Cognitive function did not significantly differ between before and after trihexyphenidyl treatment. However, after trihexyphenidyl treatment, rCBF and rCMRO2 decreased by 15% in the striatum and by 10% in all cortical areas contralateral to predominantly symptomatic limbs, and by 10% in the ipsilateral striatum and all cortical areas, significantly below the values of controls in most cerebral cortices and striatum. These findings suggest that trihexyphenidyl inhibits the cortical cholinergic system and significantly decreases rCBF and rCMRO2 in the cerebral cortices without cognitive impairment in untreated patients with PD.

Suppression of transforming growth factor beta and vascular endothelial growth factor in diabetic nephropathy in rats by a novel advanced glycation end product inhibitor, OPB-9195

AIMS/HYPOTHESIS

Advanced glycation end products (AGEs) participate in the pathogenesis of diabetic nephropathy. We reported earlier that OPB-9195, a synthetic thiazolidine derivative and novel inhibitor of advanced glycation, prevented progression of diabetic glomerulosclerosis by lowering serum concentrations of advanced glycation end products and reducing their deposition in the glomeruli. Here, we examined their contribution and that of growth factors, such as transforming growth factor-beta (TGF-beta) and vascular endothelial growth factor (VEGF), to the progression of diabetic nephropathy. We also investigated the expression of type IV collagen in the kidneys of Otsuka-Long-Evans-Tokushima-Fatty (OLETF) rats, a Type II (non-insulin-dependent) diabetes mellitus model, after treatment with OPB-9195.

METHODS

Using northern blots and immunohistochemical techniques, we determined the renal expression of TGF-beta and type IV collagen mRNAs and proteins in OLETF rats. We also examined OPB-9195's effects on renal expression of VEGF mRNA and protein.

RESULTS

Concomitant increases in TGF-beta and type IV collagen expression were observed at each point in time in OLETF rats not given OPB-9195. In contrast, OPB-9195 treatment greatly suppressed the renal expression of TGF-beta, VEGF and type IV collagen mRNAs and proteins to that seen in non-diabetic rats.

CONCLUSION/INTERPRETATION

Since OPB-9195, an AGE-inhibitor, prevented the progression of diabetic nephropathy by blocking type IV collagen production and suppressing overproduction of two growth factors, TGF-beta and VEGF, in diabetic rats, this compound warrants further investigation.

A three-month repeated oral administration study of a low viscosity grade of hydroxypropyl methylcellulose in rats

The toxicity of the lowest viscosity grade of hydroxypropyl methylcellulose (HPMC) that is currently commercially available was investigated by means of a three-month repeated oral administration study in male and female Crj:CD (SD) IGS rats at doses of 505, 1,020 and 2,100 mg/kg/day. Body weights of males and females in the 2,100 mg/kg group were lower than those of the control group on and after day 28 of administration, but the differences were not statistically significant. The degree of suppression of body weight gain in males was higher than that in females. This tendency was similar to the results in other toxicity studies of HPMC that have been reported. Males in the 2,100 mg/kg group showed a tendency (not significant) for decreased food consumption and urine volume. Examinations of general signs, hematology, blood chemistry, ophthalmology, absolute and relative organ weights, autopsy and histopathology revealed only a few, apparently coincidental, statistically significant differences from the control, and no evidence of any dose-dependent changes was found. It was concluded that the lowest viscosity grade of HPMC showed extremely low toxicity under the conditions of this study, as has been found for higher viscosity grades.

Dry coating: an innovative enteric coating method using a cellulose derivative

A novel enteric coating method was developed. This method involves direct feeding of coating polymer powder and simultaneous spraying of plasticizing agent, without either organic solvent or water, using a centrifugal granulator, fluidized bed, or tablet-coating machine. For film formation, a curing step was then necessary; this involved spraying a small amount (3-8% of core weight) of water or hydroxypropyl methylcellulose solution, followed by heating. Hydroxypropyl methylcellulose acetate succinate was used as the enteric coating polymer, and a combination of triethyl citrate and acetylated monoglyceride was used for plasticization. The coated beads and tablets were evaluated for gastric resistance, intestinal disintegration, and stability, in comparison with beads and tablets from a conventional aqueous coating with the same enteric polymer. The new method required a higher coating amount for gastric resistance compared with the conventional coating, but the processing time was dramatically reduced. The results show that this dry coating method is applicable to the preparation of enteric-coated beads and tablets using commercially available lab-scale apparatus.

Application of extremely low viscosity methylcellulose (MC) for pellet film coating

Pellet film coating has very limited applicability compared with tablet film coating, because of the problem of sticking during fluidized bed operation. We have prepared an extremely low viscosity methylcellulose (MC) (4 mPa.s), and examined its solution and film properties and its suitability for pellet film coating. MC lost its adhesiveness at a relatively high moisture content and pellet film coating could be achieved without agglomeration of the pellets within a reasonable operating time. The coated pellets were covered with a continuous film of MC, and drug release from the coated pellets was as rapid as that from the core. These findings suggest that MC (4 mPa.s) is applicable for pellet film coating in an aqueous system.

Skin sensitization and photosensitization studies of hydrophobically modified hydroxypropyl methylcellulose in guinea pigs

Skin sensitization and photosensitization tests of hydrophobically modified hydroxypropyl methylcellulose (HM-HPMC), a new cellulose derivative used as a thickener for topical pharmaceuticals, were conducted using guinea pigs. An aqueous dispersion of HM-HPMC (3 w/v %) was applied in the tests. Skin reaction was not observed in any animal in the HM-HPMC-treated group or control group. In the photosensitization test, no skin reaction was found in any animal in the test-preparation group or the control group. It was concluded that HM-HPMC dispersion does not exhibit skin sensitizing or photosensitizing activity under the condition of this test.

Cerebral blood flow and oxygen metabolism before and after a stroke-like episode in patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS)

Cerebral blood flow and oxygen metabolism were examined in two patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) using positron emission tomography (PET). Regional cerebral blood flow (rCBF), regional cerebral oxygen metabolic rate (rCMRO2) and regional oxygen extraction fraction (rOEF) were determined with the steady-state technique using oxygen-15-labeled tracers (15O2, C15O2 and C15O). Case 1, a 45-year-old woman, presented with abrupt onset of fluent aphasia. T2-weighted magnetic resonance imaging (MRI) showed a high signal intensity lesion in the left temporoparietal region. The first PET study on day 16 showed increased rCBF and decreased rCMRO2 in the temporal region. In the second PET study, on day 35, rCBF in the temporal region had decreased. Case 2 was a 19-year-old male; the second son of Case 1. He complained of transient blurring of vision, and then generalized tonic-clonic convulsion occurred. A PET study six days before this stroke-like episode demonstrated increased rCBF in both frontal lobes and putamen, where MRI showed lesions after the episode. Focal hyperemia of the lesion antedated and lasted for at least sixteen days after the stroke-like episode in these MELAS patients. These stroke-like episodes appear to be the result of metabolic dysfunction in neural tissue, although the role of an ischemic vascular event cannot be ruled out.

Calcifying epithelioma (pilomatrixoma) of the head and neck: analysis of 37 cases

OBJECTIVE

To review all cases of pilomatrixoma (calcifying epithelioma) of the head and neck published in Japanese dental journals 1977-1994.

DESIGN

Retrospective review.

SETTING

University hospital, Japan.

SUBJECTS

37 Patients with 38 tumours, mean age 23 years, female: male ratio 2.4:1.

INTERVENTIONS

Enucleation alone (n=29, 78%), excision including covering skin (n=7, 19%), or excision including superficial lobe of parotid (n=1, 3%).

MAIN OUTCOME MEASURE

Presentation, site, recurrence, and histological features.

RESULTS

Two patients had multiple tumours (5%). Most of the tumours were firm nodules covered with normal skin varying in size from 5 to 30 mm. The most common site was the preauricular region; 22 (58%) were in the anterior part. The follow up period ranged from 7 to 43 months during which there was only one recurrence. Tumours were encapsulated and solid composed of either shadow and basophilic cells or shadow cells alone, and the stroma contained varying amounts of calcification, ossification, and keratinization.

CONCLUSIONS

The diagnosis should be suspected when the mass is adherent to the skin but not fixed to the underlying tissue. It is difficult to distinguish between benign and malignant tumours by imaging methods alone, so the recommended treatment must be complete excision including adherent skin.

Pharmacological properties of traditional medicines. XXIII. Searching for active compounds in the blood and bile of rats after oral administrations of extracts of sansohnin [symbol: see text]

We made a trial of searching for the bioactive substances from Sansohnin [symbol: see text]. The blood and bile of rats after the oral administration of extracts of Sansohnin were analyzed by three-dimensional high-performance liquid chromatography (3D-HPLC). In blood, spinosin and feruloyl spinosin were found after the oral administration of a butanol extract of Sansohnin. In bile, spinosin and feruloyl spinosin were also identified after the oral administration of a water extract of Sansohnin. Spinosin and feruloyl spinosin induced the prolongation of hexobarbital sleeping time in mice at doses of 50 and 100 mg/kg, respectively. We concluded that spinosin and feruloyl spinosin were the bioactive constituents of Sansohnin. It was assumed that spinosin and feruloyl spinosin circulated through the intestine and liver, therefore, these results will provide support for the sedative and hypnotic use of this crude drug in Oriental medicine.

Development of cellulose derivatives as novel enteric coating agents soluble at pH 3.5-4.5 and higher

Hydroxypropyl methylcellulose (HPMC) was selected as a base polymer to develop novel enteric coating agents for acid protection which can dissolve at pH around 4, and was modified with trimellitic acid or maleic acid at various degrees of substitution. These carboxylic acids have higher dissociation constants and higher solubility in water than the carboxylic acids of existing enteric coating polymers. The synthesized polymers were micronized and dispersed in aqueous medium to determine their pKa values by potentiometric titration. The pH of dissolution and the water vapor permeability of the cast films prepared from organic solutions were also evaluated. Hydroxypropyl methylcellulose trimellitate (HPMCT) showed good acid resistance, and the pH at which it dissolves can be controlled in the range of pH 3.5 to 4.5 by varying the content of trimellityl groups and the methoxyl substitution of the base polymer.

A repeated-dose dermal toxicity study of hydrophobically modified hydroxypropyl methylcellulose in rats

A six-month repeated-dose dermal toxicity study followed by a 30-day recovery test of hydrophobically modified hydroxypropyl methylcellulose (HM-HPMC), a new cellulose derivative used as a thickener for topical pharmaceuticals, was conducted using rats. Aqueous paste of HM-HPMC was applied to the skin of rats once daily at dose levels up to 60 mg/kg/day, which was the highest dose that could be administered. Items checked included general signs, urinalysis, hematology, ophthalmology, and histopathology. One rat died during the administration period owing to a malignant tumor in the hemopoietic system, which was not attributed to the test substance. Statistically significant differences were found in some test results, but those were not dose-dependent and were considered to be incidental or spontaneous. It was concluded that the test substance was not toxic upon chronic dermal administration at dose levels up to 60 mg/kg/day.