Association Between Interdialytic Weight Gain, Perception About Dry Weight, and Dietary and Fluid Behaviors Based on Body Mass Index Among Patients on Hemodialysis.

OBJECTIVE: This study aimed to identify dietary and fluid behaviors associated with relative interdialytic weight gain (RIDWG) (divided by the respective dry weight [DW]) by stratifying the patients according to body mass index (BMI). DESIGN AND METHODS: This was a cross-sectional, multicenter investigation. Between July 2016 and March 2017, data were collected from 4 Japanese dialysis centers in 3 cities. The patients (n = 577) were asked to reply to a self-completed questionnaire, including questions on perception about DW and dietary and fluid behaviors. The differences in perception about DW and dietary and fluid behaviors were compared between RIDWG nonadherence (average RIDWG ≥5％ a month) and adherence subgroups. RESULTS: The 360 participants were stratified into thin (<20; 28.6%), normal low (≥20 and <22; 22.5%), normal high (≥22 and <25; 31.7%), and overweight (≥25; 17.2%) groups on the basis of BMI. In the thin and normal low BMI groups, the RIDWG nonadherent patients were more likely to identify their DW as "looking to increase." Although the difference was less prominent between the adherence subgroups in the thin BMI group, the RIDWG nonadherent patients in normal low BMI group seemed to generally take less care to intentionally regulate their behaviors as a representative of sodium-intake/fluid management. Although patients with a larger body size (overweight and normal high BMI groups) were not associated with this perception about DW, they were associated with some demographic characteristics; regarding the normal high BMI group, a higher proportion of RIDWG nonadherent patients worked full-time, and they more frequently reported an irregular eating pattern. CONCLUSION: Dietary and fluid behaviors associated with RIDWG differed according to the BMI group. Assessing more specific types of patient behaviors, focusing on the underlying factors associated with dietary and fluid behaviors, and taking BMI into consideration are required.

Change in albumin measurement method affects diagnosis of nephrotic syndrome.

BACKGROUND: Although serum albumin levels (sALB) have been quantified by the dye-binding method with bro- mocresol green (BCG) or bromocresol purple (BCP) on a routine basis, accurate measurement of sALB with these methods is difficult. The modified BCP method is highly specific to albumin without being affected by sample preservation to enable stable and accurate quantification of albumin concentrations. A change in the albumin measurement method may alter the diagnosis of nephrotic syndrome. METHODS: sALB was measured in 295 patients including 98 patients with chronic renal disease by the modified BCP method, BCG method, and immunonephelometry as the gold standard. RESULTS: sALB measured by the modified BCP method was well correlated with levels measured by immunonephelometry. sALB obtained by the BCG method was significantly higher than the levels measured by the modified BCP method (p < 0.001, Student's t-test). This tendency was more evident in patients with chronic renal disease than other patients. When the threshold value of sALB for the diagnosis criteria of nephrotic syndrome (≤ 25 g/L) and a high risk of thrombosis (≤ 20 g/L) in nephrotic syndrome was based on the BCG method, the revised criteria in the modified BCP method would be ≤ 20.5 and ≤ 14.9 g/L, respectively. CONCLUSIONS: Overestimation of sALB by the BCG method affected diagnosis of nephrotic syndrome. The method by which sALB is measured should be specified in both clinical and research settings in nephrology.

Associations between patterns of participation in community activities and social support, self-efficacy, self-rated health among community-dwelling older adults.

Certain types of community-based social activities improve the health issues of older adults; however, the present patterns of participation in community activities remain unknown. This study aims 1) to identify community-dwelling older adults' patterns of participation in community-based activities and 2) to evaluate the relationships between social support, self-efficacy, self-rated health, and the patterns of participation in community activities. This cross-sectional study used data collected from 146 older adults aged ≥65 years who participated in community events in Japan in 2018. Cluster analysis was used to identify subjects' patterns of participation in community activities. In the multinomial logistic regression model, the participation pattern (dependent variable), and social support and self-efficacy (independent variables), were included, adjusting for age, sex, and years of residency. Three participation pattern clusters were identified: diverse activities (58%), municipal events (30%), and senior citizen club (12%). The proportion of participants reported themselves healthy were 93%, 88%, and 78% for diverse activities, municipal events, and senior citizen club clusters, respectively. Compared to those in the senior citizen club cluster, older adults in the diverse activities cluster were more likely to have self-efficacy (adjusted odds ratio (aOR): 1.19, p = .041) and social support (aOR: 2.35, p = .018), while participants in the municipal events cluster were associated with only social support (aOR: 3.29, p = .022). Increasing social support and self-efficacy may promote seniors' participation in diverse community activities, which would be beneficial for their healthy aging. Further studies are needed to evaluate the causal relationships.

Does chromoendoscopy improve the colonoscopic adenoma detection rate?

BACKGROUND/AIMS: It is not clear whether chromoendoscopy with indigo carmine improves the rate of detection of colorectal polyps compared to: detection via standard colonoscopy. The aim of our study was to determine whether chromoendoscopy with indigo carmine significantly improves the detection of adenomas in the distal colon and rectum. METHODOLOGY: Using back-to-back sigmoidoscopies in each study patient, we prospectively evaluated whether chromoendoscopy with indigo carmine picked up more adenomatous polyps than standard colonoscopy. In all patients, standard high-resolution complete colonoscopy without indigo carmine was performed at the first examination. The second examination was restricted to colonoscopy distal to the splenic flexure of the colon. For the second examination, patients were randomized to chromoendoscopy with indigo carmine or colonoscopy without indigo carmine application. The second examination's detection rate was compared between the two groups. RESULTS: In the 60 patients in the chromoendoscopy with indigo carmine group, 38 adenomas were found in the first examination and 14 adenomas in the second examination. In the 70 patients in the standard colonoscopy group, 66 adenomas were found in the first examination and 32 adenomas in the second examination. The detection rates in the two groups were 26.9% and 32.7%, re spectively, which were not significantly different (p = 0.47). CONCLUSION: Chromoendoscopy did not detect more adenomatous polyps in comparison to standard colonoscopy.

Differences in characteristics of raters who use the visual estimation method in hospitals based on their training experiences.

BACKGROUND & AIMS: Despite a clinical need, only a few studies have provided information concerning visual estimation training for raters to improve the validity of their evaluations. This study aims to describe the differences in the characteristics of raters who evaluated patients' dietary intake in hospitals using the visual estimation method based on their training experiences. METHODS: We collected data from three hospitals in Tokyo from August to September 2016. The participants were 199 nursing staff members, and they completed a self-administered questionnaire on demographic data; working career; training in the visual estimation method; knowledge, attitude, and practice associated with nutritional care; and self-evaluation of method validity of and skills of visual estimation. We classified participants into two groups, experienced and inexperienced, based on whether they had received training. Square test, Mann-Whitney U test, and univariable and multivariable logistic regression analysis were used to describe the differences between these two groups in terms of their characteristics; knowledge, attitude, and practice associated with nutritional care; and self-evaluation of method validity and tips used in the visual estimation method. RESULTS: Of the 158 staff members (79.4%) (118 nurses and 40 nursing assistants) who agreed to participate in the analysis, thirty-three participants (20.9%) were trained in the visual estimation method. Participants who had received training had better knowledge (2.70 ± 0.81, score range was 1-5) than those who had not received any training (2.34 ± 0.74, p = 0.03). Score of self-evaluation of method validity of the visual estimation method was higher in the experienced group (3.78 ± 0.61, score range was 1-5) than the inexperienced group (3.40 ± 0.66, p < 0.01). Mean total scores of using tips in the visual estimation method in the experienced and inexperienced groups were 19.6 ± 1.76 and 17.9 ± 2.28, respectively (score range was 6-24), differing significantly between the two groups (p < 0.01). Multivariable logistic regression revealed that participants who had been trained had adequate knowledge (OR: 2.78, 95% CI: 1.05-7.35) and frequently used tips in visual estimation (OR: 1.85, 95% CI: 1.26-2.73). CONCLUSION: Trained participants had more required knowledge and they used visual estimation tips more frequently than participants who had not been trained in the visual estimation method. This study provides new evidence for the importance of training clinical staff members to use the visual estimation method appropriately and makes suggestions to improve the validity of the visual estimation method.

Differences in the validity of a visual estimation method for determining patients' meal intake between various meal types and supplied food items.

BACKGROUND & AIMS: The aim of this study was to examine differences in the validity of a visual estimation method for determining patients' meal intake between various meal types and supplied food items in hospitals and to find factors influencing the validity of a visual estimation method. METHODS: There are two procedures by which we obtained the information on dietary intake of the patients in these hospitals. These are both by visual assessment from the meal trays at the time of their clearing, by the attending nursing staff and by weighing conducted by researchers. The following criteria are set for the target trays: A) standard or therapeutic meals, which are monitored by a doctor, for energy and/or protein and/or sodium; B) regular, bite-sized, minced and pureed meal texture, and C) half-portion meals. Visual assessment results were tested for their validity by comparing with the corresponding results of weighing. Differences between these two methods indicated the estimated and absolute values of nutrient intake. RESULTS: A total of 255 (76.1%) trays were included in the analysis out of the 335 possible trays and the results indicated that the energy consumption estimates by visual or weighing procedures are not significantly different (412 ± 173 kcal, p = 0.15). However, the mean protein consumption was significantly different (16.3 ± 6.7 g/tray, p < 0.01) between the two procedures. Compared with standard meals (38 ± 45 kcal, 1.9 ± 2.5 g/tray), raters significantly misestimated the energy and protein intake of half-portion meals (78 ± 65 kcal, 2.8 ± 2.2 g/tray, p = 0.01) but accurately estimated the protein intake of protein controlled meals (0.5 ± 0.6 g/tray, p = 0.03). Trays adding supplied food items were significantly misestimated for energy intake (66 ± 58 kcal/tray) compared to trays with no additions (32 ± 39 kcal/tray, p < 0.01). Moreover, the results of multivariable analysis demonstrated that supplied food items were significantly associated with increased odds of a difference between the two methods (OR: 3.84; 95% confidence interval [CI]: 1.07-13.85). CONCLUSIONS: There were high correlations between the visual estimation method and the weighing method measuring patients' dietary intake for various meal types and textures, except for meals with added supplied food items. Nursing staff need to be attentive to supplied food items.

[Ciliated hepatic foregut cyst: report of a case and a summary of the 24 cases reported in Japan].

We report a 52-year-old patient with a small hepatic mass which was ultrasonographically anechoic with scattered high echoic spots, and appearing slightly hyperattenuating relative to the surrounding parenchyma on unenhanced CT scans. Laparotomy revealed that the lesion was a unilocular cyst containing a mucinous fluid. The histologic diagnosis was ciliated hepatic foregut cyst (CHFC). The CHFC is a rare congenital cystic tumor which derives from the embryologic foregut. Up to 2006, only 24 cases, including our case, had been reported in Japan. The patients were 13 men and 11 women, aged between 41 years and 79 years. All of the lesions were solitary and unilocular. In 22 cases, the CHFC was located in the medial segment of the left lobe, mostly just beneath the hepatic surface. In all 24 Japanese cases, the cystic wall was benign histologically. However, reports of 3 malignant cases overseas indicates we should treat this disease cautiously.

Birbeck granules, worm-like bodies and "lupus erythematosus virus".

The origin of worm-like bodies and their relationship with Birbeck granules is poorly understood. To clarify the origin of worm-like bodies and their relationship with Birbeck granules. Over 800 electron micrographs of histiocytic disorders and several appendage tumours were reviewed in order to check for worm-like bodies and Birbeck granules. Worm-like bodies were most often encountered in mildly- to moderately-proliferative histiocytic tumours. Birbeck granules were observed in more malignant conditions. Narrow endoplasmic reticulum (Nrer), which resembles worm-like bodies, was abundant in worm-like body-rich cells and coexisted with Birbeck rods. Nrer is thought to be one of the candidates that gives rise to worm-like bodies. An ultrastructural similarity exists between worm-like bodies (and octopus body formation) and the so-called "lupus erythematosus virus". The presence of Nrer is often concomitant with other organelle markers, and could be a candidate for the origin of worm-like bodies.

Gold-Catalyzed Anti-Markovnikov Selective Hydrothiolation of Unactivated Alkenes.

Despite the widespread use of transition-metal catalysts in organic synthesis, transition-metal-catalyzed reactions of organosulfur compounds, which are known as catalyst poisons, have been difficult. In particular, the transition-metal-catalyzed addition of organosulfur compounds to unactivated alkenes remains a challenge. A novel gold-catalyzed hydrothiolation of unactivated alkenes is presented, which proceeds effectively to give the anti-Markovnikov-selective adducts in good yields and in a regioselective manner.

A new high-pressure strontium germanate, SrGe2O5.

The Sr-Ge-O system has an earth-scientific importance as a potentially good low-pressure analog of the Ca-Si-O system, one of the major components in the constituent minerals of the Earth's crust and mantle. However, it is one of the germanate systems that has not yet been fully examined in the phase relations and structural properties. The recent findings that the SrGeO3 high-pressure perovskite phase is the first Ge-based transparent electronic conductor make the Sr-Ge-O system interesting in the field of materials science. In the present study, we have revealed the existence of a new high-pressure strontium germanate, SrGe2O5. Single crystals of this compound crystallized as a co-existent phase with SrGeO3 perovskite single crystals in the sample recovered in the compression experiment of SrGeO3 pseudowollastonite conducted at 6 GPa and 1223 K. The crystal structure consists of germanium-oxygen framework layers stacked along [001], with Sr atoms located at the 12-coordinated cuboctahedral site; the layers are formed by the corner linkages between GeO6 octahedra and between GeO6 octahedra and GeO4 tetrahedra. The present SrGe2O5 is thus isostructural with the high-pressure phases of SrSi2O5 and BaGe2O5. Comparison of these three compounds leads to the conclusion that the structural responses of the GeO6 and GeO4 polyhedra to cation substitution at the Sr site are much less than that of the SrO12 cuboctahedron to cation substitution at the Ge sites. Such a difference in the structural response is closely related to the bonding nature.

Criterion validity of the visual estimation method for determining patients' meal intake in a community hospital.

BACKGROUND & AIMS: The accuracy of the visual estimation method is unknown, even though it is commonly used in hospitals to measure the dietary intake of patients. We aimed to compare the difference in the validity of visual estimation according to the raters' job categories and tray divisions, and to demonstrate associations between meal characteristics and validity of visual estimation in a usual clinical setting in a community hospital. METHODS: We collected patients' dietary intake data in usual clinical settings for each tray in 3 ways: visual estimation by nursing assistants, visual estimation by dietitians, and weighing by researchers (reference method). Dietitians estimated the dietary intake using 2 divisions, namely, whole tray and food items. Then we compared the weights and visual estimation data to evaluate the validity of the visual estimation method. RESULTS: Mean nutrient consumption of target trays was significantly different when using the visual estimation of target trays than when using the weighed method (visual estimation by nursing assistants [589 ± 168 kcal, 24.3 ± 7.0 g/tray, p < 0.01], dietitians' whole trays [561 ± 171 kcal, 23.0 ± 6.9 g/tray, p < 0.05], food items [562 ± 171 kcal/tray, p < 0.05], and dietitians' food items [23.4 ± 7.3 g/tray, p = 0.63]). Spearman's correlations for both methods were very high for energy (ρ = 0.91-0.98, p < 0.01) and protein intakes (ρ = 0.88-0.96, p < 0.01), respectively. The limits of agreement in the Bland-Altman plot for both dietary intake categories were -121 kcal to 147 kcal/tray and -6.4 g to 7.0 g/tray (nursing assistants, whole division), -122 kcal-106 kcal/tray and -6.7 g to 5.5 g/tray (dietitians, whole divisions), and -82 kcal to 66 kcal/tray and -4.3 g to 3.9 g/tray (dietitians, food items divisions). High intake rate of grains was significantly associated with decreased odds of a difference between two methods based on the nursing assistant's whole tray evaluation (odds ratio [OR]: 0.85; 95% confidence interval [CI]: 0.76-0.94) and the dietitians' whole tray (OR: 0.80; 95% CI: 0.72-0.89) and food items evaluations (OR: 0.64; 95% CI: 0.56-0.73), respectively. In addition, minced meals were also associated with a difference between two methods, for the nursing assistants' whole tray (OR: 3.53; 95% CI: 1.66-7.51) and dietitians' food items (OR: 2.92; 95% CI: 1.37-6.22). CONCLUSIONS: Visual estimation by nursing assistants and dietitians correlated highly with the weighing method although the limits of agreement were wide. Nursing assistants and dietitians should pay attention to low consumption and modified texture meals when evaluating dietary intake using the visual estimation method.

[Tuberculosis and human rights].

Tuberculosis (TB) patients must be hospitalized while the smear of sputum is positive because TB spreads through air. Cooperation of a patient is important in order to complete the treatment of TB. However, a small number of patients are noncooperative for the treatment and may sometimes refuse it. At this symposium, we discussed about whether we could restrict the human rights of noncooperative TB patients. Although the patients' human rights must be protected, we also have to protect the human rights of people who may receive TB infection. The balance of the both people's rights is fully considered in the TB control policy. It is epoch-making that the TB society took up the theme about the human rights' restriction of TB patients. Five speakers presented their papers from each position. There were presentations about the scientific evidence of isolation, the actual cases, the situation of the United States, and the legal view on the human rights' restriction of TB patients. The present situation and the legal problems in Japan became clear at this symposium. We need further discussion about the human rights' restriction of TB patients for the revision of the Tuberculosis Protection Act and have to obtain the national consensus on it. 1. The evidence for isolation: Emiko TOYODA (International Medical Center of Japan) To determine appropriate periods of respiratory isolation, available biological, clinical, and epidemiological issues and data were studied. Although absolute lack of infectiousness requires consecutive culture negative and it takes too long and impractical periods. There seems to be no established evidence for noncontagiousness after 2 to 3 weeks effective treatment. Practically conversion to 3 negative consecutive smear results may used as a surrogate for noninfectiousness, even though a small risk of transmission still be present. Chemical isolation has been more important and administration with DOT should be indicated to keep compliance. 2. Discontinued hospitalization in tuberculosis patient: Yoshiko KAWABE (National Hospital Organization Tokyo National Hospital) We investigated the background of tuberculosis patients who entered our hospital in 11 years from 1993 to 2003 and discontinued hospitalization. Out of 4,126 cases 76 cases (1.8 %) discontinued hospitalization. We classify three groups. One is self discharged group who leaved hospital without permission. Second is obligatory discharged group who were displaced for some trouble. Third is transferred group who were transferred to another hospital including mental hospital that have ward for tuberculosis. Major reasons were drinking during hospitalization, violence, roam because of dementia and major backgrounds were repeatedly noncompliant patients, homeless people, and suffering from senile dementia. We concluded we need some legal intervention for few cases who cannot continue hospitalization. 3. Tuberculosis control policy and human rights in public health center: Keiko FUJIWARA (Infection Diseases Control Division, Public Health Bureau, City of Yokohama) It is required for a success of the tuberculosis control policy to consider human rights. Patients' human rights should be respected, and surrounding people's human rights should also be respected. We sometimes see a tuberculosis patient who cannot continue tuberculosis treatment. A society as a whole has to share the recognition of tuberculosis as a social illness. The completion of tuberculosis treatment is not only the benefit of individual, but also it is very important as social defense. When we revise the tuberculosis control policy, we should think about both protecting a society from tuberculosis and protecting tuberculosis patients' human rights and obtain national consensus. 4. The mandatory TB control policy in the US: Hidenori MASUYAMA (Shibuya Dispensary, Japan Anti-TB Association) The mandatory TB control policy in the US was discussed. If the mandatory health policy would be applied, the following three criteria of human rights must be satisfied. 1. The health of others will be adversely affected without a mandatory program. 2. The mandatory program is the least restrictive alternative. 3. The mandatory program is implemented equitably without purposeful bias. For example, the mandatory DOT could not satisfy these criteria. Before applying the mandatory TB control policy in Japan, the TB patient's autonomy and social cooperation of TB therapy need to be considered. 5. Tuberculosis and guarantee of human rights: Shigeru TAKAHASHI (Graduate School of Law, Hitotsubashi University) In modern administrative Law the relations between Governments and peoples are regarded not as the facing relationships between Governments and the peoples, who submit to the interventions by Government, but as the triangle relationships between Governments, the peoples who submit to the interventions by Governments and the peoples who enjoy benefits from the interventions by Governments. When we make a new design of the Tuberculosis Protection Act, we must at first take considerations of the human rights of the tuberculosis patients from the view points of due Process of Law. And we must also take considerations of the human rights of the peoples who are threatened with the risks of tuberculosis infection.

[Usefulness of QuantiFERON TB-2G in contact investigation of a tuberculosis outbreak in a university].

PURPOSE: This study examined the usefulness of QuantiFERON TB-2G (QFT) i.e., a novel technique for detecting tuberculosis infection based on the whole blood interferon-gamma response to specific antigens, in the investigation of a tuberculosis outbreak among university students. SUBJECTS AND METHOD: One university student was diagnosed as smear-positive pulmonary tuberculosis. In order to determine the extent of tuberculosis infection among contact students, tuberculin skin tests and QFT were performed on the close-contact group (220 people), as well as on the non-close-contact group (242 people). RESULTS: Nine students were found to be TB either clinically or on the X-ray screening in the contact investigation. In the close-contact group, the QFT-positive rate was 32.7%. The proportion of those exhibiting tuberculin reactions with erythema diameters of 30 mm or larger was 57.7%. In the non-close-contact group, the QFT-positive rate was only 0.8 %, as expected from the current healthy Japanese youths of this age. In contrast, strong tuberculin reactions with erythema of 30 mm or larger were seen in 18.2% in the latter group, most likely due to the previous history of BCG vaccination. CONCLUSION: QFT was clearly demonstrated to be a useful method for diagnosing tuberculosis infection, especially among subjects who show tuberculin reactivity due to past BCG vaccination. At the same time, the current criteria for the indication of chemoprophylaxis based on the strong tuberculin reaction were considered to be unreliable, causing many subjects with strong reactions to be given unnecessary preventive medications.

Crystal structure of SrGeO3 in the high-pressure perovskite-type phase.

Single crystals of the SrGeO3 (strontium germanium trioxide) high-pressure phase have been synthesized successfully at 6 GPa and 1223 K. The compound crystallizes with the ideal cubic perovskite-type structure (space group Pm-3m), which consists of a network of corner-linked regular GeO6 octa-hedra (point-group symmetry m-3m), with the larger Sr atoms located at the centers of cavities in the form of SrO12 cubocta-hedra (point-group symmetry m-3m) in the network. The degrees of covalencies included in the Sr-O and the Ge-O bonds calculated from bond valences are 20.4 and 48.9%, respectively. Thus, the Ge-O bond of the GeO6 octa-hedron in the SrGeO3 perovskite has a strong covalency, comparable to those of the Si-O bonds of the SiO4 tetra-hedra in silicates with about 50% covalency. The thermal vibrations of the O atoms in the title compound are remarkably suppressed in the directions of the Ge-O bonds. This anisotropy ranks among the largest observed in stoichiometric cubic perovskites.

Crystal structure of post-perovskite-type CaIrO3 reinvestigated: new insights into atomic thermal vibration behaviors.

Single crystals of the title compound, the post-perovskite-type CaIrO3 [calcium iridium(IV) trioxide], have been grown from a CaCl2 flux at atmospheric pressure. The crystal structure consists of an alternate stacking of IrO6 octa-hedral layers and CaO8 hendeca-hedral layers along [010]. Chains formed by edge-sharing of IrO6 octa-hedra (point-group symmetry 2/m..) run along [100] and are inter-connected along [001] by sharing apical O atoms to build up the IrO6 octa-hedral layers. Chains formed by face-sharing of CaO8 hendeca-hedra (point-group symmetry m2m) run along [100] and are inter-connected along [001] by edge-sharing to build up the CaO8 hendeca-hedral layers. The IrO6 octa-hedral layers and CaO8 hendeca-hedral layers are inter-connected by sharing edges. The present structure refinement using a high-power X-ray source confirms the atomic positions determined by Hirai et al. (2009 ▸) [Z. Kristallogr. 224, 345-350], who had revised our previous report [Sugahara et al. (2008 ▸). Am. Mineral. 93, 1148-1152]. However, the displacement ellipsoids of the Ir and Ca atoms based on the present refinement can be approximated as uniaxial ellipsoids elongating along [100], unlike those reported by Hirai et al. (2009 ▸). This suggests that the thermal vibrations of the Ir and Ca atoms are mutually suppressed towards the Ir⋯Ca direction across the shared edge because of the dominant repulsion between the two atoms.

A novel strategy for preparing nanoporous biphasic calcium phosphate of controlled composition via a modified nanoparticle-assembly method.

Biphasic calcium phosphate (BCP) consisting of hydroxyapatite (HAp) and ß-tricalcium phosphate is usually prepared by thermal decomposition of calcium-deficient HAp (CDHAp). However, the calcium deficiency and morphology of CDHAp are difficult to manipulate in parallel. In this study, we report a novel strategy for controlling the composition of nanoporous BCP by using only CDHAp nanoparticles with specific properties (Ca/P molar ratio, 1.61; particle size, 50 nm) as a building block and by adjusting the calcium deficiency of the nanoparticle-assembled CDHAp (Ca/P molar ratio, 1.50-1.67; pore size, 8 nm) with the addition of water-soluble Ca(NO3)2 or (NH4)2HPO4. After thermal treatment at 1000 °C, the composition of BCP could be predictably controlled by adjusting the Ca/P ratio of the nanoparticle-assembled CDHAp. Changes in the Ca/P ratio did not significantly affect the surface morphology of BCP, but the grain size (210-300 nm) and pore size (140-170 nm) tended to increase slightly as the Ca/P ratio decreased. The porosity significantly decreased upon the addition of Ca salts (porosity, 20%) or PO4 salts (porosity, 14%) compared with that of the sample without additives (porosity, 53%). In vitro tests demonstrated enhanced cell adhesion on nanoporous BCP compared with densely sintered pure HAp, and cell differentiation was promoted on the nanoporous pure HAp.

Expansion of nanosized pores in low-crystallinity nanoparticle-assembled plates via a thermally induced increase in solid-state density.

We investigated thermally induced changes in a low-crystallinity hydroxyapatite (HAp)-nanoparticle-assembled plate containing nanosized pores. We first prepared an aqueous dispersion of low-crystallinity HAp nanoparticles (particle size, 48 nm) via a wet chemical process and then prepared the nanoparticle-assembled plate by drying the dispersion on an oil substrate to prevent crack formation. Before the plates were subjected to heat treatments, they contained 7.9-nm-sized pores because of the gap between the nanoparticles, and their porosity was 60%. After the heat treatments (600-1100 °C) were performed for 1 h, the solid-state density determined using helium pycnometry increased from 2.85 to 3.21 g/cm(3), and the pore size increased from 7.9 to 250 nm. These results indicate that the pore size expanded because of increases in crystallinity and density, despite the large decrease in the total volume because of thermally induced sintering of the nanoparticles.

Induced radioactivity in the blood of cancer patients following Boron Neutron Capture Therapy.

Since 1990, Boron Neutron Capture Therapy (BNCT) has been used for over 400 cancer patients at the Kyoto University Research Reactor Institute (KURRI). After BNCT, the patients are radioactive and their (24)Na and (38)Cl levels can be detected via a Na-I scintillation counter. This activity is predominantly due to (24)Na, which has a half-life of 14.96 h and thus remains in the body for extended time periods. Radioactive (24)Na is mainly generated from (23)Na in the target tissue that is exposed to the neutron beam in BNCT. The purpose of this study is to evaluate the relationship between the radioactivity of blood (24)Na following BNCT and the absorbed gamma ray dose in the irradiated field. To assess blood (24)Na, 1 ml of peripheral blood was collected from 30 patients immediately after the exposure, and the radioactivity of blood (24)Na was determined using a germanium counter. The activity of (24)Na in the blood correlated with the absorbed gamma ray doses in the irradiated field. For the same absorbed gamma ray dose in the irradiated field, the activity of blood (24)Na was higher in patients with neck or lung tumors than in patients with brain or skin tumors. The reasons for these findings are not readily apparent, but the difference in the blood volume and the ratio of bone to soft tissue in the irradiated field, as well as the dose that leaked through the clinical collimator, may be responsible.

Prediction of groundwater contamination with 137Cs and 131I from the Fukushima nuclear accident in the Kanto district.

We measured the concentrations of (131)I, (134)Cs, and (137)Cs released from the Fukushima nuclear accident in soil and rainwater samples collected March 30-31, 2011, in Ibaraki Prefecture, Kanto district, bordering Fukushima Prefecture to the south. Column experiments revealed that all (131)I in rainwater samples was adsorbed onto an anion-exchange resin. However, 30% of (131)I was not retained by the resin after it passed through a soil layer, suggesting that a portion of (131)I became bound to organic matter from the soil. The (137)Cs migration rate was estimated to be approximately 0.6 mm/y in the Kanto area, which indicates that contamination of groundwater by (137)Cs is not likely to occur in rainwater infiltrating into the surface soil after the Fukushima accident.