Waves in planetary dynamos

This Special Topic focuses on magnetohydrodynamic (MHD) processes in the deep interiors of planets, in which their fluid dynamos are in operation. The dynamo-generated, global, magnetic fields provide a background for our solar-terrestrial environment. Probing the processes within the dynamos is a significant theoretical and computational challenge and any window into interior dynamics greatly increases our understanding. Such a window is provided by exploring rapid dynamics, particularly MHD waves about the dynamo-defined basic state. This field is the subject of current attention as geophysical observations and numerical modellings advance. We here pay particular attention to torsional Alfvén waves/oscillations and magnetic Rossby waves, which may be regarded as typical axisymmetric and nonaxisymmetric modes, respectively, amongst a wide variety of wave classes of rapidly rotating MHD fluids. The excitation of those waves has been evidenced for the Earth - whilst their presence has also been suggested for Jupiter. We shall overview their dynamics, summarise our current understanding, and give open questions for future perspectives.

Masticatory Behavior Change with a Wearable Chewing Counter: A Randomized Controlled Trial

Because a relationship has been reported between masticatory behavior, obesity, and postprandial blood glucose, it is recommended to chew well and take a longer time to eat. The purpose of this study was to examine the possibility of changing masticatory behavior using a small ear-hung wearable chewing counter, which can monitor masticatory behavior without disturbing daily meals. In total, 235 healthy volunteers participated in a 4-wk randomized controlled trial and were divided into 3 groups. All participants were instructed about the importance of mastication at the first visit. During the intervention, group B used the chewing counter without an algorithm during each meal (notification of the number of chews after meal), and group C used the chewing counter with a masticatory behavior change algorithm (setting a target value and displaying the number of chews in real time). Group A was set as the control group. The number of chews and the meal time when consuming 1 rice ball (100 g) were measured before and after the intervention using the chewing counter, and the rate of change in these values was evaluated. Participants also provided a subjective evaluation of their changes in masticatory behavior. The number of chews and the meal time of 1 rice ball increased significantly in groups B and C compared with before the intervention, and the rate of change was significantly higher in group C than in group A and group B. In addition, the subjective evaluation of the change in the number of chews was highest in group C. Self-monitoring of masticatory behavior by providing a target value and the degree of achievement for the number of chews using a wearable chewing counter with a behavioral change algorithm could promote effective change in masticatory behavior and lead to an increased number of chews. (Trial ID: UMIN000034476).

Comprehensive Analyses of the Bacterial Population in Non-Healing Claw Lesions of Dairy Cattle

Non-healing claw lesions (NHCLs) are a newly characterized disorder affecting the deep dermis of the hoof in dairy cattle. Although NHCLs are thought to be associated with bovine digital dermatitis (BDD), their precise etiology is not yet understood. To investigate the bacterial populations present in each type of NHCL (toe necrosis: TN, non-healing white line disease: nhWLD, and a non-healing sole ulcer: nhSU), and the newly added entity non-healing verrucous-like lesions (nhVLL), 16S rRNA-based metagenomic analysis with next-generation sequencing (NGS) was employed. Twelve cases of NHCLs (3 TN, 3 nhWLD, 4 nhSU, and 2 nhVLL) were collected from five dairy farms in two prefectures in Japan. Three samples of healthy hoof dermis collected from two farms and a slaughterhouse were used as controls. Furthermore, culture-dependent and -independent approaches were conducted for detecting Treponema species and Fusobacterium necrophorum. As reported in BDD, Treponema species and F. necrophorum were detected frequently from NHCLs by PCR and immunohistochemistry, but NGS showed that these bacterial genera were not predominant in NHCLs. The predominant bacterial genera in NHCLs differed among the lesions examined, suggesting that Treponema species present predominantly in BDD were not predominant in NHCLs and that the bacterial population in NHCLs may vary among individual cattle and/or farms.

Efficacy of fosfomycin in the prevention of postoperative infection following transurethral resection of bladder tumor during periods of limited cefazolin, cefotiam, and cefmetazole supply

INTRODUCTION

In March 2019, cefazolin availability was limited owing to the contamination of the drug substance. In addition, there was a difficulty in supplying drugs alternative to cefazolin, such as cefotiam and cefmetazole. In our Department of Nephro-urology, we used fosfomycin-based drugs to substitute cefazolin as perioperative preventive antibacterial drugs. In this study, we aimed to evaluate the usage status of perioperative prophylactic antibacterial drugs before and after the period of limited cefazolin supply and to investigate the efficacy and safety of fosfomycin sodium in preventing infections following transurethral resection of bladder tumor.

METHODS

We enrolled 346 patients who underwent transurethral resection of bladder tumor in our department from April 2018 to August 2020. The patients received the following perioperative antibacterial agents: cefotiam (n = 146), fosfomycin (n = 166), and other antibacterial agents (n = 34). There was no significant difference in the median age or surgery time.

RESULTS

The median length of hospital stay was 6, 5, and 5 days in the cefotiam, fosfomycin, and other antibacterial groups, respectively, with significant difference. The median maximum postoperative temperature was 37.1 °C in all groups, with no significant difference. There were no differences in C-reactive protein, aspartate aminotransferase, and alanine aminotransferase levels determined by postoperative blood tests; preoperative and postoperative urinary white blood cell counts; preoperative urine bacterial counts; and surgery-related infection requiring additional antibiotic treatments among the groups.

CONCLUSIONS

The use of fosfomycin-based agents helped overcome the limited supply of cefazolin without worsening clinical outcomes.

Automatic detection of early gastric cancer in endoscopic images using a transferring convolutional neural network

Endoscopic image diagnosis assisted by machine learning is useful for reducing misdetection and interobserver variability. Although many results have been reported, few effective methods are available to automatically detect early gastric cancer. Early gastric cancer have poor morphological features, which implies that automatic detection methods can be extremely difficult to construct. In this study, we proposed a convolutional neural network-based automatic detection scheme to assist the diagnosis of early gastric cancer in endoscopic images. We performed transfer learning using two classes (cancer and normal) of image datasets that have detailed texture information on lesions derived from a small number of annotated images. The accuracy of our trained network was 87.6%, and the sensitivity and specificity were well balanced, which is important for future practical use. We also succeeded in presenting a candidate region of early gastric cancer as a heat map of unknown images. The detection accuracy was 82.8%. This means that our proposed scheme may offer substantial assistance to endoscopists in decision making.

Basic study of random sampling for compressed sensing using MRI simulator

INTRODUCTION

Magnetic resonance imaging (MRI) is a tomography technology that enables the depiction of anatomical structures with information about various features. Compressed sensing (CS) technology has recently been used for magnetic resonance image reconstruction from sparse information. Random sampling methods based on the various probability density function (PDF) are being developed to allow the efficient application of CS technology. Accurate numerical simulation is obviously important for the evaluation of the sampling method that are developed. In this study, the simulation method with MRI simulator and actual MRI scanner was carried out. Moreover, the difference between the result acquired from our simulation and basic one was revealed.

METHODS

We first examined a basic method using a 2D Shepp-Logan phantom. This method was only conducted with k-space data obtained from the 2D Fourier transform of the original image. Our method of numerical simulation was applied with the MRI simulator (Bloch Solver, MRI simulations Inc.), an actual MRI system (Vantage Titan 3T, Canon Medical Systems) and a phantom (CAGN-3.0T phantom, Kato Medience). The real and imaginary part of the k-space were acquired with the MRI simulator using a phase map that was imaged by the actual MRI scanner. Random sampling was performed with two types of PDF and image reconstruction was processed by projection onto convex sets (POCS). Hermitian symmetry is a point-symmetry respect to origin and each point located on the opposite side maintains a relation of complex conjugate. Thus, there is no need to acquire data that formed in point-symmetry with the data that had already been acquired. We used the gaussian random sampling method (GA) and a method that considered Hermitian symmetry (GH). The image quality was evaluated using the normalized root mean squared error (NRMSE).

RESULTS AND DISCUSSION

In the basic simulation, the average and standard deviation of NRMSE from GH was better than that from GA because consideration of the Hermitian symmetry enables the efficient acquisition of data. However, in our method of numerical simulation, the average and standard deviation of the NRMSE from GH was worse than that from GA. In this simulation method, the phase error was included in the real and imaginary part of the k-space; thus, the Hermitian symmetry cannot hold and the calculation error of reconstruction images from GH stood out.

CONCLUSION

The method of numerical simulation with the MRI simulator using a phase map was close to the actual conditions and was considered to be useful for the validation of new sampling methods. The random sampling method using GH is expected to be useful for the highly efficient acquisition of data under ideal conditions; however, more accurate phase correction is necessary to apply the actual measurement data.

Long-term follow-up of custom cross-pin fixation of 56 tumour endoprosthesis stems: a single-institution experience

AIMS

Aseptic loosening is a major cause of failure in cemented endoprosthetic reconstructions. This paper presents the long-term outcomes of a custom-designed cross-pin fixation construct designed to minimize rotational stress and subsequent aseptic loosening in selected patients. The paper will also examine the long-term survivorship and modes of failure when using this technique.

PATIENTS AND METHODS

A review of 658 consecutive, prospectively collected cemented endoprosthetic reconstructions for oncological diagnoses at a single centre between 1980 and 2017 was performed. A total of 51 patients were identified with 56 endoprosthetic implants with cross-pin fixation, 21 of which were implanted following primary resection of tumour. Locations included distal femoral (n = 36), proximal femoral (n = 7), intercalary (n = 6), proximal humeral (n = 3), proximal tibial (n = 3), and distal humeral (n = 1).

RESULTS

The median follow-up was 132 months (interquartile range (IQR) 44 to 189). In all, 20 stems required revision: eight for infection, five for structural failure, five for aseptic loosening, and two for tumour progression. Mechanical survivorship at five, ten, and 15 years was 84%, 78%, and 78%, respectively. Mechanical failure rate varied by location, with no mechanical failures of proximal femoral constructs and distal femoral survivorship of 82%, 77%, and 77% at five, ten, and 15 years. The survivorship of primary constructs at five years was 74%, with no failure after 40 months, while the survivorship for revision constructs was 89%, 80%, and 80% at five, ten, and 15 years.

CONCLUSION

The rate of mechanical survivorship in our series is similar to those reported for other methods of reconstruction for short diaphyseal segments, such as compressive osseointegration. The mechanical failure rate differed by location, while there was no substantial difference in long-term survival between primary and revision reconstructions. Overall, custom cross-pin fixation is a viable option for endoprosthetic reconstruction of short metaphyseal segments with an acceptable rate of mechanical failure. Cite this article: Bone Joint J 2019;101-B:724-731.

Combustion Study of Different Transitional Metal Oxide based on AN/MgAl Composites Gas Generators

Ammonium nitrate (AN)-based composite gas generator have attracted a considerable amount of attention because of the clean burning nature of AN as an oxidizer. However, ammonium nitrate-based gas generator has several major problems, namely, poor ignitability, a low burning rate, low energy, and high hygroscopicity. The addition of different transitional metal oxides and MgAl mechanical alloyed proved to be effective in improving the burning characteristics of AN-based gas generator. In this research work, combustion study of different transition metal oxide based on AN/MgAl composites gas generators was studied. Gas generators were combusted at the pressure of 1 MPa, 3 MPa and 5 MPa in the combustion chamber and the burning rates were determined. It was stated that the addition of metal oxides into the composition of the gas generators improves ignition at low pressure and increases the burning rate. The use of the mechanical MgAl alloys as a fuel allowed the ignition of the gas generator at a lower temperature. The method of thermogravimetric/differential thermal analyzer (TG/DTA) was used to investigate the effect of metal oxides addition on the AN/MgAl-based gas generators thermal decomposition characteristics.

Combustion Characteristics of HAN-based Green Propellant Assisted with Nanoporous Active Carbons

Combustion of hydroxylammonium nitrate (95 wt.% HAN) ‒ water solution in presence of high specific surface area activated carbons is investigated in a constant-pressure bomb within the pressure range of 1‒6 MPa. The linear burning rate increased for the system of HAN admixed with activated carbons compared to those of the HAN alone. Moreover, the thermal decomposition of HAN (95 wt.%) ‒ water solution spiked with activated carbons was assessed by DTA – TG method. In the presence of activated carbons, the ability to trigger the decomposition at a lower temperature (86 °C vs 185 °C) was observed. The volatile products formed in the course of thermal decomposition of HAN, spiked with activated carbons were characterized by electron ionization mass spectrometry analysis. Primary products of HAN decomposition: m/z = 33 (NH2OH) and m/z = 63 (HNO3), which are further responsible for the formation of secondary products such as N2O, NO, HNO2, NO2, O2 etc. Significant reduction of NOx emissions during thermal decomposition of HAN (95 wt.%) ‒ water solution was observed (ca. 30%) in presence of activated carbons.

Detection of the Plasmodium falciparum Kelch-13 gene P553L mutation in sporozoites isolated from mosquito salivary glands in South-Central Vietnam

Background

Plasmodium falciparum has developed resistance against artemisinin in Southeast Asia. Mutations in the P. falciparum Kelch-13 (Pfk13) gene are associated with artemisinin resistance in vitro and in vivo. We investigated the prevalence of mutations in PfK13 from sporozoite-stage parasites isolated from the salivary glands of Anopheles dirus mosquitoes.

Methods

Mosquitoes were caught by human-landing catches at two locations within the Khanh Phu commune, South-Central Vietnam. Identification of Anopheles species was performed based on morphological features and nucleotide sequence analysis. Sporozoite-infected salivary glands were stored on filter paper and at 4–6 °C. A nested-PCR targeting the small subunit ribosomal RNA gene was used for Plasmodium species identification. Pfk13 was amplified by nested PCR, and subjected to nucleotide sequencing.

Results

Five of 33 P. falciparum sporozoite samples carried the P553L mutation at the PfK13 locus. This mutation has been recorded previously in Vietnam, but not in Khanh Hoa province, were surveys of K13 polymorphism have not previously been carried out.

Conclusion

These results demonstrate the utility of mosquito-stage malaria parasite samples for studies on the molecular epidemiology of drug resistance.

Development of a novel algorithm for detecting glucocorticoid-induced diabetes mellitus using a medical information database

WHAT IS KNOWN AND OBJECTIVE

Glucocorticoid-induced diabetes mellitus (GIDM) increases the risk of diabetes mellitus (DM)-related complications but is generally difficult to detect in clinical settings. The criteria for diagnosing GIDM have not been established. Recently, medical information databases (MIDs) have been used in post-marketing surveillance (PMS) studies. We conducted a pharmacoepidemiological study to develop an algorithm for detecting GIDM using MID.

METHODS

We selected 1214 inpatients who were newly prescribed with a typical glucocorticoid, prednisolone, during hospitalization from 2008 to 2014 from an MID of Hamamatsu University Hospital in Japan. GIDM was screened based on fasting blood glucose (FBG) and haemoglobin A1c (HbA1c) levels according to the current Japan Diabetes Society (JDS) DM criteria, and its predictability was evaluated by an expert's review of medical records. We investigated further candidate screening factors using receiver operating characteristics analysis.

RESULTS

Sixty-three inpatients were identified by the JDS DM criteria. Of these, 33 patients were definitely diagnosed as having GIDM by expert's review (positive predictive value = 52·4%). To develop a highly predictive algorithm, we compared the characteristics of inpatients diagnosed with definite GIDM and those diagnosed as non-GIDM. The maximum levels of HbA1c in patients with GIDM were significantly higher than those of patients with non-GIDM (66·9 mmol/mol vs. 58·7 mmol/mol, P < 0·001). The patients with GIDM had significantly higher relative increase in maximum level of HbA1c (RIM-HbA1c) than those with non-GIDM (0·3 vs. 0·03, P < 0·001). However, we did not observe a significant difference in those of fasting blood glucose (FBG) levels. We applied the RIM-HbA1c as a second screening factor to improve the detection of GIDM. It showed that a 13% increase in RIM-HbA1c separated patients with from patients without GIDM.

WHAT IS NEW AND CONCLUSIONS

Patients with GIDM had significantly higher RIM-HbA1c than patients with non-GIDM. There was a 13% increase in RIM-HbA1c in patients with GIDM compared to the others. Our detection algorithm for GIDM using an MID achieved high sensitivity and specificity, and was superior to one based only on the current JDS DM criteria. Our results suggest that monitoring changes in HbA1c levels is important for detecting GIDM and adds to current diagnostic criteria for type 2 DM.

Influence of Human Jaw Movement on Cerebral Blood Flow

Temporal changes in cerebral blood flow induced by jaw movement have yet to be investigated. To assess the influence of pattern and intensity of muscle contraction during jaw movement on task-induced change in cerebral blood flow, we performed bilateral transcranial Doppler ultrasound examination during clenching, gum chewing, and tooth tapping in healthy volunteers. A random-effects model analysis revealed a significant increase in middle cerebral artery blood flow velocity during clenching (high muscle activity) and gum chewing (moderate muscle activity), compared with the preceding rest period; however, such an increase was not detected during tooth tapping (low muscle activity). Cerebral blood flow was greater on the working side during the intensive isometric contraction of the masseter muscle in clenching. These results suggest that task-induced change in cerebral blood flow during jaw movement is influenced by the change in peripheral circulation evoked by muscle contraction.

Coordination of Tongue Pressure and Jaw Movement in Mastication

The tongue plays an important role in mastication and swallowing by its contact with the hard palate. Using an experimental palatal plate with 7 pressure sensors, and recording jaw movement using mandibular kinesiography, we assessed, in healthy subjects, the coordination of tongue and jaw movements during the entire masticatory sequence of solids, by measuring tongue pressure against the hard palate. Tongue pressure appeared during the occlusal phase, reached a peak near the start of opening, and disappeared during opening. Specific patterns in order, duration, and magnitude of tongue pressure were seen at the 7 pressure sensors in each chewing stroke. Magnitude and duration were significantly larger in the late stage of chewing (8 strokes before initial swallowing) than in the early stage (until 8 strokes after starting mastication). The normal pattern of tongue contact against the hard palate, control of tongue activity, and coordination with jaw movement during mastication is described.

Validation of the distress and impact thermometer and the changes of mood during the first 6 months of treatment in gynecological cancer patients: a Kansai Clinical Oncology Group (KCOG)-G1103 prospective study

PURPOSE

To verify distress and impact thermometer (DIT) for screening emotional distress in gynecological cancer patients by Hospital Anxiety and Depression Scale total (HADS-T) as gold standard and to assess emotional changes by DIT and HADS-T.

METHODS

A prospective study was conducted in newly diagnosed gynecological cancer patients during the peri-treatment period after the cancer diagnosis followed by 6-month. We defined a HADS-T score of ≥11 as being indicative of emotional distress.

RESULTS

117 patients were enrolled between May 1, 2011 and March 31, 2012, and 95 were eligible. The median age was 54 years (range 31-77). (1) From the baseline to 3-month, distress (DIT-D) ≥4 with Impact (DIT-I) ≥2 exhibited sensitivity, specificity, positive predictive value (PPV), and negative predictive values (NPV) of 0.776 [95 % confidential interval (CI) 0.688, 0.850], 0.889 (95 % CI 0.824, 0.954), 0.868 (95 % CI 0.792, 0.949), and 0.808 (95 % CI 0.731, 0.886), respectively. (2) At 6-month, DIT-D ≥2 with DIT-I ≥1 exhibited sensitivity, specificity, PPV and NPV of 0.893 (95 % CI 0.778, 1), 0.825 (95 % CI 0.707, 0.942), 0.781 (95 % CI 0.638, 0.928), and 0.917 (95 % CI 0.826, 1). (3) At 6-month, the HADS-T, DIT-D, and DIT-I scores in individual patients were significantly reduced by a mean of 4.57 (p < 0.0001), 2.34 (p < 0.0001), and 1.10 (p = 0.0031), respectively, compared with those scores of baseline (Student's paired t test), but still remained high.

CONCLUSIONS

(1) On acute phase within 3-month setting, DIT; DIT-D ≥4 with DIT-I ≥2, is a reliable cut-off to screen emotional distress among gynecological cancer patients. (2) The patients' moods had improved, but not completely recovered at 6-month after the diagnosis.

Gynandroblastoma of postmenopausal women: a case report

Gynandroblastoma, an extremely rare ovarian tumour that usually consists of both Sertoli stromal cell and granulosa cell tumours, often produces both androgenic and estrogenic effects. The authors herein report a case of gynandroblastoma with the longest disease-free period reported to date. A 66-year-old woman without metrorrhagia or hirsutism presented with abdominal pain and slightly elevated serum estradiol levels. Her uterus was enlarged, and endometrial curettage performed to reduce endometrial thickness prior to laparotomy led to a diagnosis of atypical endometrial hyperplasia. She was diagnosed of ovarian tumour. The pathology report revealed that the right ovarian tumour was a "gynandroblastoma". Such lesions are classified as borderline malignant. Postoperative adjuvant therapy was not administered in this case because only a few recurrent or fatal cases have been reported. The lesion was classified as pTlaN0M0 according to Union for International Cancer Control (UICC). The patient is alive and has been disease-free for 77 months post-surgery.

Proton pump inhibitor after endoscopic resection for esophageal squamous cell cancer: multicenter prospective randomized controlled trial

BACKGROUND

Whether proton pump inhibitors (PPIs) relieve heartburn or precordial pain after endoscopic resection (ER) for esophageal squamous cell carcinoma (ESCC) remains unclear. The aim of this study was to investigate the efficacy of PPI therapy for these symptoms after ER for ESCC.

METHODS

We conducted a multicenter prospective randomized controlled trial among 15 hospitals in Japan. In total, 229 patients with cT1a ESCC were randomly assigned to receive PPI therapy for 5 weeks after ER (the PPI group, n = 115) or follow-up without PPI therapy (the non-PPI group, n = 114). The primary end point was the incidence of gastroesophageal reflux disease (GERD)-like symptoms after ER from a self-reported questionnaire (Frequency Scale for Symptoms of GERD). Secondary end points were ulcer healing rate at 5 weeks, incidence of pain, improvement rate of symptoms in those who started PPI therapy because of GERD-like symptoms in the non-PPI group, and adverse events.

RESULTS

No significant difference was observed in the incidence of GERD-like symptoms after ER between the non-PPI and PPI groups (30 % vs 34 %, respectively). No significant differences were observed in the ulcer healing rate at 5 weeks (84 % vs 85 %) and incidence of pain within 1 week (36 % vs 45 %). In nine of ten patients (90 %) who started PPI therapy because of GERD-like symptoms in the non-PPI group, PPI administration relieved GERD-like symptoms. No adverse events related to PPI administration were observed.

CONCLUSION

PPI therapy is not efficacious in reducing symptoms and did not promote healing of ulcers in patients undergoing ER for ESCC.

Tongue pressure production during swallowing in patients with mandibular prognathism

Abnormalities of swallowing in patients with mandibular prognathism have not been evaluated quantitatively. The aim of this study was to compare tongue pressure production for bolus transfer between volunteers with normal occlusion and patients with mandibular prognathism. The control group had 10 female volunteers with normal occlusion, and the patient group had 10 women with mandibular prognathism. Tongue pressure was measured by a palatal sensor sheet at five sites on swallowing 4 mL of a tasteless and odourless jelly.

RESULTS

The tongue pressure waveform differed between the control and patient groups. The incidence of a double-peak tongue pressure waveform was more frequent in the patient group. In both groups, the exertion of tongue pressure began at the anterior point of the sensor sheet, followed by the peripheral parts. Although the order of expression of tongue pressure was the same for the two groups, maximum tongue pressure at all parts of the sensor sheet was lower in the patient group than in the control group. Furthermore, swallowing time was longer in the patient group than in the control group at the peripheral parts of the palate. These results clearly show the difference in tongue pressure production during swallowing between patients with mandibular prognathism and volunteers with normal occlusion. The current findings suggest that maxillofacial morphology may affect tongue movement during swallowing.

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.