Accelerated preprocessing of large numbers of brain images by parallel computing on supercomputers.

"Preprocessing" is the first step required in brain image analysis that improves the overall quality and reliability of the results. However, it is computationally demanding and time-consuming, particularly to handle and parcellate complicatedly folded cortical ribbons of the human brain. In this study, we aimed to shorten the analysis time for data preprocessing of 1410 brain images simultaneously on one of the world's highest-performing supercomputers, "Fugaku.

Use of organic solvents in large research institutions in Japan.

Objectives: Laboratories in research institutions use organic solvents in research and development. Nevertheless, the types of solvents in use have been seldom reported. This study was initiated to elucidate types of organic solvents used in large research institutions in Japan, with a focus on possible different use among research fields.

Performance tests of three types of air-sampling bags on organic solvent vapor retention.

Performance of two new air sampling bags [the transparent bag (TP bag) and the semi-transparent bag (ST bag)] was examined as possible surrogates for the traditional PVF bag (the Ref bag). Solvent vapor mixture of butyl acetate, chloroform, ethyl acetate, isopropyl alcohol and toluene at administrative control levels were introduced to each bag (n=5 for each of the three types), and the decay in the concentrations (by%) was followed by use of a gas auto-sampler - FID-GC system. A trend of time-dependent decay was noted for all types including the Ref bag.

Variation in benchmark dose (BMD) and the 95% lower confidence limit of benchmark dose (BMDL) among general Japanese populations with no anthropogenic exposure to cadmium.

Background: The use of benchmark dose (BMD) and the 95% lower confidence limit of benchmark dose (BMDL) have been gaining popularity not only in experimental studies but also in epidemiological studies including those on toxicology of cadmium (Cd), a ubiquitous hazardous element in the environment. However, the reproducibility of BMD and BMDL values has seldom been examined.

Objectives: This study was initiated to determine whether consistent BMD and BMDL values are obtained for similar non-exposed populations, i.

Comparative evaluation of GFAAS and ICP-MS for analyses of cadmium in blood.

Cadmium in blood (Cd-B) is an important indicator, next to Cd in urine, in biological monitoring of exposure to Cd. The present study was initiated to examine compatibility in results of analysis for Cd-B between graphite furnace atomic absorption spectrophotometry (GFAAS) and inductively-coupled plasma mass-spectrometry (ICP-MS). For this purpose, 1,159 blood samples were collected from adult women (with no occupational exposure to Cd) in eight prefectures nation-widely in Japan.

Cadmium, chromium, lead, manganese and nickel concentrations in blood of women in non-polluted areas in Japan, as determined by inductively coupled plasma-sector field-mass spectrometry.

Background: Background levels of metals of toxicological or industrial importance have been reported for several populations in the world. The information on the levels of metals of industrial, occupational or clinical importance in blood of general Japanese populations is however still scarce.

Objectives: The objectives of the study were to establish background levels of Cd, Cr, Mn, Ni and Pb in blood of Japanese population using inductively coupled plasma-sector field mass spectrometry (ICP-SF-MS), which was expected to be sensitive enough to measure low-level Pb in blood of general populations.

Estimation of dietary Pb and Cd intake from Pb and Cd in blood or urine.

Successful trials were made to estimate the dietary daily intake of lead (Pb) and cadmium (Cd) via foods from the levels of the metals in blood or urine. In practice, 14 and 15 reports were available for Pb and Cd in blood (Pb-B and Cd-B), urine (Pb-U and Cd-U) and 24-h diet duplicates (Pb-D and Cd-D), respectively, from which 68 pairs each of Pb or Cd in blood and food duplicates [each being geometric mean (GM) values for the survey sites] were obtained. Regression analysis revealed that there was a significant correlation between Pb-B and Pb-D, and also between Cd-B and Cd-D, suggesting that it should be possible to estimate both Pb-D and Cd-D from Pb-B and Cd-B, respectively.

Closer correlation of cadmium in urine than that of cadmium in blood with tubular dysfunction markers in urine among general women populations in Japan.

Objectives: The objectives of the present study are to investigate whether cadmium in blood (Cd-B) and cadmium in urine (Cd-U) correlate with each other irrespective of age among general populations and which one of Cd-B or Cd-U correlates more closely with three renal tubular dysfunction markers in urine of α₁-microglobulin (α₁-MG-U), β₂-microglobulin (β₂-MG-U) and N-acetyl-β-D-glucosaminidase (NAG-U).

Methods: Data on two exposure markers (Cd-B and Cd-U) and three effect markers (α₁-MG-U, β₂-MG-U and NAG-U) were collected for 1,403 adult women in non-polluted areas all over Japan. Possible significance of correlation between the parameters and dependency on age was examined by simple and multiple regression analysis.

Cadmium and tubular dysfunction marker levels in urine of residents in non-polluted areas with natural abundance of cadmium in Japan.

Objectives: Literature survey has suggested that cadmium (Cd) in the general environment is more abundant in the northern part of the coast on the sea of Japan. The present survey was initiated to examine if the exposure to Cd in the area has been higher than other parts of Japan, and if so, the higher exposure has been associated with tubular dysfunction among the local residents.

Methods: In three prefectures of Akita, Yamagata and Ishikawa in the region, adult women (about 700 subjects per prefecture) were invited to participate in the survey.

N-acetyl-beta-D-glucosaminidase (NAG) as the most sensitive marker of tubular dysfunction for monitoring residents in non-polluted areas.

Alpha(1)-microglobulin (alpha(1)-MG), beta(2)-microglobulin (beta(2)-MG) and N-acetyl-beta-D-glucosaminidase (NAG) are tubular dysfunction markers often used in cadmium (Cd) epidemiology. The purpose of the present study was to identify the best maker among the above-referred three that correlates most closely with Cd in urine of residents with no known Cd pollution. Survey was conducted in 2007-2008 in three prefectures in Japan.

Limited validity of o-cresol and benzylmercapturic acid in urine as biomarkers of occupational exposure to toluene at low levels.

This study was initiated to evaluate o-cresol and benzylmercapturic acid in urine in comparison with other biomarkers, as tools to estimate the intensity of occupational exposure to toluene at low levels. In total, 108 solvent exposed workers (engaged in tape production) and 17 non-exposed controls (all men) participated in the study. The surveys were conducted in the second half of working weeks.

Changes in correlation coefficients of exposure markers as a function of intensity of occupational exposure to toluene.

This study was initiated to identify a marker of choice to monitor occupational exposure to toluene through quantitative evaluation of changes in correlation coefficients (CCs), taking advantage of a large database. Six known or proposed exposure markers in end-of-shift blood (B) and urine (U) were studied, i.e.

Biological variations in cadmium, alpha 1-microglobulin, beta 2-microglobulin and N-acetyl-beta-D-glucosaminidase in adult women in a non-polluted area.

Objectives: This study was initiated to investigate the extents of biological variations in cadmium and three common tubular dysfunction marker levels in blood and urine through repeated sampling.

Methods: A 12-month survey and a 10-week survey were conducted in an area with no known cadmium pollution. In the 12-month survey, five adult women offered urine samples once every month and blood samples once in every season, respectively.

Evaluation of biomarkers of occupational exposure to toluene at low levels.

Objectives: The purpose of the present study was to compare validity of various biomarkers of occupational exposure to toluene (Tol) at low levels. The focus was placed on the comparison of un-metabolized toluene in urine (Tol-U) and peripheral blood (Tol-B) with hippuric acid in urine (HA-U).

Methods: Surveys were conducted in 16 workplaces on the second half of working weeks, with participation of male solvent workers.

Comparative evaluation of biomarkers of occupational exposure to toluene.

Objectives: This study was initiated to make comparative evaluation of five proposed urinary markers of occupational exposure to toluene, i.e., benzyl alcohol, benzylmercapturic acid, omicron-cresol, hippuric acid and un-metabolized toluene.

Changes in tubular dysfunction marker levels in parallel with the levels of copper, rather than cadmium, in urine of middle-aged women in non-polluted areas.

Objective: This study was initiated to investigate if and to what extent the elevations in urinary alpha(1)- and beta(2)-microglobulins (alpha(1)-MG and beta(2)-MG, respectively) are specific to Cd nephro-toxicity.

Methods: Stored urine samples, collected from 1,000 adult women in 11 prefectures all over Japan, were analysed for eight elements (Ca, Cd, Co, Cu, Mg, Mn, Ni and Zn), alpha(1)-MG, beta(2)-MG, creatinine (CR) and specific gravity (SG); the data were cited from previous publications. The levels of eight elements and two MGs were expressed as observed and after correction for CR or SG (1.

Reference values for cobalt, copper, manganese, and nickel in urine among women of the general population in Japan.

Objective: The present study was initiated to establish the reference levels of Co, Cu, Mn, and Ni in urine of women in the general Japanese population.

Methods: Stored urine samples were subjected to the analysis. The samples were collected from 1,000 adult women all over Japan, who had no occupational exposure to these elements.

Relation of average and highest solvent vapor concentrations in workplaces in small to medium enterprises and large enterprises.

The present study was initiated to examine the relationship between the workplace concentrations and the estimated highest concentrations in solvent workplaces (SWPs), with special references to enterprise size and types of solvent work. Results of survey conducted in 1010 SWPs in 156 enterprises were taken as a database. Workplace air was sampled at > or = 5 crosses in each SWP following a grid sampling strategy.

Field survey on types of organic solvents used in enterprises of various sizes.

Objective: To examine (1) common types of organic solvent work and prevalent types of solvent used, and (2) possible association of high solvent concentration with types of solvent work and with enterprise size.

Methods: The present survey was conducted in Kyoto, Japan, in April 2004 to March 2005. Air samples were collected in 1,010 solvent workplaces (SWPs) (>or=5 samples/SWP) in 156 enterprises of various sizes, and analyzed for 47 legally designated organic solvents by flame-ionization detector-equipped gas-liquid chromatography.

Comparison of colorimetric and HPLC methods for determination of delta-aminolevulinic acid in urine with reference to dose-response relationship in occupational exposure to lead.

Both traditional colorimetry and recently developed HPLC-fluorometry have been in use for determination of delta-aminolevulinic acid in urine (ALA-U), an effect marker of occupational exposure to lead (Pb). The present study was initiated to compare the values by the two methods on an epidemiology basis among workers occupationally exposed to lead (Pb), to estimate quantitatively the colorimetry-associated increment over the values by the HPLC method, to evaluate ALA-U determination in occupational health service for Pb-exposed workers, and to identify a critical Pb-B to induce an elevation in ALA-U. For this purpose, blood and urine samples were collected from three groups of Pb-exposed workers (both men and women in combination, including smokers) and analyzed for Pb in blood (Pb-B; measured in all subjects) and ALA-U (by colorimetry or HPLC), i.

The threshold cadmium level that causes a substantial increase in beta2-microglobulin in urine of general populations.

Cadmium (Cd) is a toxic element ubiquitous in the environment, and general populations have been exposed to this element primarily via foods. Thus, the critical level of non-occupational Cd exposure to cause any health effects among general populations is of public health as well as toxicological concern. The objectives of the present study were to examine the quantitative relationship between cadmium (Cd-U) and beta2-microglobulin in urine (beta2-MG-U) as a marker of exposure to Cd and as a marker of renal tubular dysfunction, respectively, and to identify a threshold Cd-U, if present, in causing a substantial increase in beta2-MG-U.

Lead levels in urine of never-smoking adult women in non-polluted areas in Japan, with references to cadmium levels in urine.

The present study was initiated to assess current level of general population exposure to lead (Pb) in terms of Pb in urine (Pb-U). For this purpose, spot urine samples were collected from 2,332 never-smoking adult women in 10 areas all-over Japan, and were subjected to analysis for Pb-U by graphite furnace atomic absorption (GFAA). Data on cadmium in urine (Cd-U) as measured by GFAA were cited from a previous publication).