Environmental radiation at Izu-Oshima after the Fukushima Daiichi nuclear power plant accident

Environmental radiation at Izu-Oshima Island was observed 6 months after the accident at the Fukushima Daiichi Nuclear Power Plant (F1-NPP). A car-borne survey of the dose rate in air was conducted over the entire island and the results were compared with measurements performed in 2005 (i.e. before the accident). The activity concentrations of (134)Cs and (137)Cs were also measured using a germanium detector. The dose rate in air was found to be 2.9 ± 1.2 times higher than that in 2005 and (134)Cs was detected on Izu-Oshima Island. These results are attributed to the accident at the F1-NPP.

Functional-characterization of developing tumor vascular system and drug delivery (review)

This review summarizes our recent experiments on the process of tumor vascularization and character of tumor vessels. By vitalscopic observation with transparent chambers in rats, we found that the sites where tumor vessels originated were usually terminal portions of terminal arterioles and that an intricate tumor vascular network was constructed from incorporated preexisting vessels and newly formed vessels by three different modes, i.e., sprouting, cross-connecting and splitting. Observation and hydrogen clearance studies showed that tumor blood flow changed remarkably during the development of the tumor vascular network. At an early stage of tumor growth, there were some regions of high flow in the tumor. At an advanced stage, however, there was a rapid increase in low-flow or no-flow areas which were resistant to access of anticancer drugs and oxygen. Angiotensin II-induced hypertension produced a several-fold increase in tumor blood flow without increasing tissue blood flow of normal tissues. These good conditions for drug delivery to tumor tissue are able to enhance therapeutic effects of chemotherapy, irradiation, antibody and photodynamic therapy.

Impact of lingual plates on the interocclusal free way space: a pilot study

Palatal augmentation prostheses are commonly used in the treatment for dysphagia. By lowering the palatal contours, the tongue contact is increased and thus the bolus propulsion facilitated. However, the unfavourable weight of such appliances may be avoided when using lingual plates. Hence, the aim of this study is to investigate the effect of two different types of lingual plates on the vertical dimension in rest position. Eleven healthy dentate subjects with an average age of 35.5 years (26-60 years) volunteered in this pilot study. The vertical overbites were measured on plaster models. Two different designs of the experimental lingual plates were tested in this pilot study (P-type & D-type). The inter-occlusal freeway space was measured using the electromagnetic K7 jaw-tracking system (Myotronics, U.S.A.), while the subjects were seated in an upright position. They were asked to close from rest position into maximum intercuspation for about 2 s. Recordings were performed without the plates and subsequently with each of the two plate designs in situ. All recordings were performed three times and the second closing movement of each recording was used for the analysis. After averaging the repetitions without experimental lingual plates, with P-type and D-type plates, the differences were analysed using a Kruskall-Wallis test. The results showed no significantly increased freeway space while using both types of lingual plates. Hence, it can be concluded that any altered tongue pressure during swallowing with lingual plates is not related to an increase in vertical dimension.

Onset Patterns and Initial Symptoms of Dementia with Lewy Bodies: Possible Pathophysiological Diversities Deduced from a SPECT Study

Background/Aims

The aim of this study was to investigate onset patterns and initial symptoms in patients with dementia with Lewy bodies (DLB) and their association with SPECT findings.

Methods

We studied 29 probable and 12 possible DLB patients. Onset was defined as ‘acute’ when symptoms (in various combinations) present within a few weeks or ‘chronic’ when a few symptoms present and progress during a longer period of time. Initial symptoms were dichotomized into ‘cognitive’ and ‘non-cognitive’. We conducted voxel-to-voxel statistical analyses of SPECT, and uptake deviations from age-matched controls were depicted with Z-scores.

Results

In acute patients, decreases were more apparent in the bilateral frontal and temporal lobes, whereas chronic patients showed decreases in the bilateral occipital, posterior cingulate and precuneal regions. Differences in the left frontal and left posterior cingulate were significant and those in the left temporal region showed a tendency toward significance. Patients with cognitive symptoms demonstrated more marked decreases in the bilateral temporal, parietal, occipital, cingulate and precuneal regions. Differences in the left parietal area reached significance and the total decreases were larger in patients with cognitive than non-cognitive symptoms, with a trend toward significance.

Conclusions

The multiplicity of onset patterns and initial symptoms may possibly be based on pathophysiological diversities in DLB.

Transfer Function Analysis of Cerebral Autoregulation Dynamics during Jaw Movements

Mastication as a mild but life-long exercise has been examined as a possibility for maintaining brain function in the elderly. Little is known, however, about the cerebral circulatory response during masticatory movement. The aim of this study was to develop a monitoring system for circulation dynamics during masticatory movement and to apply this system to the study of cerebral autoregulation. Cerebral blood flow, heart rate, and arterial blood pressure were simultaneously recorded, and changes in these circulatory systems were quantitatively evaluated in 38 young healthy volunteers. Transfer function analysis was also performed on blood pressure and cerebral blood flow for investigation of cerebral autoregulation during gum chewing. Although increases in cerebral blood flow, mean blood pressure, and heart rate suggested the activation of cerebral and systemic circulation during gum chewing, increased cerebral circulation was independent of systemic circulation. Our results suggest that cerebral autoregulation is well maintained during jaw movements.

Diffuse gliomas in an adolescent with multiple enchondromatosis (Ollier's disease)

Ollier's disease is characterized by the hamartomatous proliferation of cartilage cells, producing masses termed chondromas. A patient presented with Ollier's disease which was found to be associated with diffuse gliomas. Investigating this disease is crucial as there is a high risk of sarcomatous transformation of the skeletal lesions as well as an increased risk of developing extra-osseous malignancies.

Structure and chemical synthesis of a biologically active form of renilla (sea pansy) luciferin

The structure of a biologically active form of Renilla (sea pansy) luciferin has been elucidated; this structure, confirmed by total chemical synthesis, is 3,7-dihydro-2-methyl-6-(p-hydroxyphenyl)-8-benzylimidazo [1,2-a] pyrazin-3-one. In the natural compound the methyl group at the 2 position is replaced by an unknown, more complex group. For this reason the synthetic compound is 10% as active as the natural compound in producing light with Renilla luciferase. However, the spectral properties of the two compounds are identical. In addition the rates of the luminescent reaction with both compounds are similar, and the color of the light produced is identical in each case.A compound isolated from the calcium-triggered photoprotein aequorin has been identified by Shimomura and Johnson [(1972) Biochemistry 11, 1602] to be 2-amino-3-benzyl-5-(p-hydroxyphenyl)pyrazine. This compound forms an integral part of the structure of Renilla luciferin. This, and other evidence, suggests that the structure elucidated for Renilla luciferin is a more general one associated with the luciferins of most, if not all, bioluminescent coelenterates.

Structure of native Renilla reinformis luciferin

The structure of native luciferin from the bioluminescent coelenterate Renilla reniformis is shown to be 3,7-dihydro-2-(p-hydroxybenzyl)-6-(p-hydroxyphenyl)-8-benzylimidazo[1,2-a]pyrazin-3-one by mass spectral analysis of synthetic luciferin and the luciferin derived from a protein directly involved in the bioluminescent system. A previous report of the molecular weight of luciferin is shown to be incorrect by reexamination of the spectral data and by synthesis of two derivatives. Detailed analysis of kinetic, emission, and quantum yield data for the isolated and synthetic luciferins confirms this structure. Confirmation of this structure in a number of species from different phyla suggests a common substrate for a variety of bioluminescent marine organisms.

Age-related Changes in Tongue Pressure during Swallowing

Although swallowing movement is known to change with aging, age-related differences in the tongue pressure for propelling a bolus from the oral cavity into the pharynx have yet to be investigated in a physiological condition. We hypothesized that tongue pressure during swallowing changed with aging and, using a 0.1-mm-thick sensor sheet with 5 measuring points, measured it while a 15-mL quantity of water was swallowed by young and elderly dentate individuals. Both groups showed a similar order of tongue pressure production at each point. However, the elderly group showed longer duration at each point, lower maximal magnitude in the anterio-median part of the hard palate, and higher magnitude in the circumferential parts of the hard palate than the young group. These results provide the first quantitative evidence of the age-related changes in tongue movement during natural swallowing, which could be attributed to muscle weakening and morphological changes in the oropharynx.

Novel QTLs for photoperiodic flowering revealed by using reciprocal backcross inbred lines from crosses between japonica rice cultivars

The rice japonica cultivars Nipponbare and Koshihikari differ in heading date and response of heading to photoperiod (photoperiod sensitivity). Using simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers, we conducted quantitative trait locus (QTL) analyses for heading date in a set of reciprocal backcross inbred lines (BILs) from crosses between Nipponbare and Koshihikari. Under natural-day conditions, transgressive segregation in days to heading (DTH) toward both early and late heading was observed in both BIL populations. QTL analyses revealed that two QTLs--on chromosomes 3 and 6--were involved in the difference in heading date between the parental cultivars. The Nipponbare allele at the QTLs on chromosomes 3 and 6 showed, respectively, increasing and decreasing effects on DTH in both BIL populations. The transgressive segregation observed in the BILs could be accounted for mainly by the complementary action of a set of alleles with opposing effects. Both QTLs were finely mapped as single Mendelian factors in secondary mapping populations (BC2F2 plants/BC2F3 lines). The QTL on chromosome 3 was mapped in the 1,140-kb interval between 94O03-4 (SSR) and OJ21G19-4 (SNP) and was designated Hd16. The QTL on chromosome 6 was mapped in the 328-kb interval between P548D347 (SSR) and 0007O20 (SSR) and was designated Hd17. Both Hd16 and Hd17 were involved in photoperiod sensitivity, as revealed by observation of the DTH of nearly isogenic lines of Nipponbare under short- and long-day conditions, suggesting that allelic differences in both Hd16 and Hd17 account for most of the difference in photoperiod sensitivity between the parental cultivars.

Interobserver agreement in endoscopic evaluation of reflux esophagitis using a modified Los Angeles classification incorporating grades N and M: a validation study in a cohort of Japanese endoscopists

The Los Angeles classification system is the most widely employed criteria associated with the greatest interobserver agreement among endoscopists. In Japan, the Los Angeles classification system has been modified (modified LA system) to include minimal changes as a distinct grade of reflux esophagitis, rather than as auxiliary findings. This adds a further grading M defined as minimal changes to the mucosa, such as erythema and/or whitish turbidity. The modified LA system has come to be used widely in Japan. However, there have been few reports to date that have evaluated the interobserver agreement in diagnosis when using the modified LA classification system incorporating these minimal changes as an additional grade. A total of 100 endoscopists from university hospitals and community hospitals, as well as private practices in the Osaka-Kobe area participated in the study. A total of 30 video clips of 30-40 seconds duration, mostly showing the esophagocardiac junction, were created and shown to 100 endoscopists using a video projector. The participating endoscopists completed a questionnaire regarding their clinical experience and rated the reflux esophagitis as shown in the video clips using the modified LA classification system. Agreement was assessed employing kappa (kappa) statistics for multiple raters. The kappa-value for all 91 endoscopists was 0.094, with a standard error of 0.002, indicating poor interobserver agreement. The endoscopists showed the best agreement on diagnosing grade A esophagitis (0.167), and the poorest agreement when diagnosing grade M esophagitis (0.033). The kappa-values for the diagnoses of grades N, M, and A esophagitis on identical video pairs were 0.275-0.315, with a standard error of 0.083-0.091, indicating fair intraobserver reproducibility among the endoscopists. The study results consistently indicate poor agreement regarding diagnoses as well as fair reproducibility of these diagnoses by endoscopists using the modified LA classification system, regardless of age, type of practice, past endoscopic experience, or current workload. However, grade M reflux esophagitis may not necessarily be irrelevant, as it may suggest an early form of reflux disease or an entirely new form of reflux esophagitis. Further research is required to elucidate the pathophysiological basis of minimal change esophagitis.