Neurodevelopmental associations of prenatal and postnatal methylmercury exposure among first-grade children in the Kinan region, Japan

The most severe effects of methylmercury (MeHg) exposure during child development are thought to result from exposure during fetal life and childhood. However, comparing the neurodevelopmental effects of prenatal and postnatal MeHg exposure (PreMeHg and PostMeHg, respectively) remains unclear. We aimed to investigate the associations between neurodevelopmental indicators and PreMeHg or PostMeHg. The participants were 134 children in the first grade of elementary schools aged 7-8 years from the Kinan region, an area with high consumption of MeHg-rich whales and tunas in Japan. We measured MeHg levels in preserved umbilical cord tissues and total mercury (T-Hg) levels in children's hair to estimate PreMeHg and PostMeHg levels, respectively. Neuropsychological (intelligence quotient testing and Boston Naming Test) and neurophysiological (brainstem auditory evoked potential [BAEP], visual evoked potential [VEP], and color vision tests) studies were performed to evaluate the neurodevelopmental status. Multiple regression analyses were conducted according to sex. The geometric mean MeHg levels in preserved umbilical cord tissues and T-Hg levels in children's hair were 0.11 μg/g and 2.94 μg/g, respectively. Neither PreMeHg nor PostMeHg was related to neuropsychological indicators. Some associations between MeHg exposure and neurophysiological results were observed only in boys. N145 latency in VEPs was significantly prolonged with increasing PreMeHg (β: 12.01, 95% confidence interval [CI]: 0.648, 23.38). The III-V interpeak intervals in BAEP were significantly prolonged with increasing PreMeHg or PostMeHg (β [95% CI]: 0.142 [0.041, 0.243] and 0.159 [0.052, 0.265], respectively). After adjusting for PreMeHg, the association between PostMeHg and BAEP latencies disappeared. In conclusion, the latency in the auditory and visual pathways was significantly prolonged with increasing PreMeHg in boys. These findings suggest that male fetuses may be more susceptible to MeHg exposure.

Epstein-Barr virus-associated inflammatory pseudotumor variant of follicular dendritic cell sarcoma of the liver: a case report and review of the literature

BACKGROUND

Follicular dendritic cell sarcoma is a rare stromal tumor with no standard treatment. However, some reports have revealed that follicular dendritic cell sarcoma has an inflammatory pseudotumor variant associated with Epstein-Barr virus infection that has a relatively good prognosis. In this report, we present a case of a resected inflammatory pseudotumor variant of follicular dendritic cell sarcoma of the liver, and have reviewed the literature on the clinicopathological, molecular, and genomic features of this tumor.

CASE PRESENTATION

The inflammatory pseudotumor variant of follicular dendritic cell sarcoma originates only in the liver or spleen, causes no symptoms, and is more common in middle-aged Asian women. It has no characteristic imaging features, which partially explains why the inflammatory pseudotumor variant of follicular dendritic cell sarcoma is difficult to diagnose. Pathologically, the inflammatory pseudotumor variant of follicular dendritic cell sarcoma has spindle cells mixed with inflammatory cells and is variably positive for follicular dendritic cell markers (CD21, CD23, and CD35) and Epstein-Barr virus-encoded RNA. On genetic analysis, patients with this tumor high levels of latent membrane protein 1 gene expression and extremely low levels of host C-X-C Chemokine Receptor type 7 gene expression, indicating that the inflammatory pseudotumor variant of follicular dendritic cell sarcoma has a latent Epstein-Barr virus type 2 infection.

CONCLUSIONS

The inflammatory pseudotumor variant of follicular dendritic cell sarcoma is an Epstein-Barr virus-associated tumor and a favorable prognosis by surgical resection, similar to Epstein-Barr virus-associated gastric cancer.

Ku-band multichannel frequency comb Doppler reflectometer on the GAMMA 10/potential control and divertor simulating experiment (PDX) tandem mirror

A Ku-band (12-18 GHz) multichannel Doppler reflectometer (DR) has been developed in the GAMMA 10/potential control and divertor simulating experiment (PDX) tandem mirror device to improve the applicability of DR measurement for simultaneous monitoring of velocity of electron density turbulence at different locations. Our previous single-channel DR circuit has been replaced by the multichannel microwave system using a nonlinear transmission line based comb generator with heterodyne technique. The multichannel DR system has been installed in the central cell of GAMMA 10/PDX. Initial results of application to GAMMA 10/PDX plasma are presented, showing Doppler frequency shifts during an additional ion cyclotron resonance frequency heating and gas-puffing experiment.

POS0390 GENES OF “DEFENSE RESPONSE TO VIRUS” IN PERIPHERAL BLOOD OF ANTI-MDA5 POSITIVE DERMATOMYOSITIS WERE UPREGULATED AS COMPARE WITH OTHER FORMS OF DERMATOMYOSITIS. ~SUPPRESSING RIG-I LIKE RECEPTOR SIGNALING OR TYPE 1/2 INTERFERON SIGNALING WERE THE KEYS FOR SURVIVAL

Background

Anti-melanoma differentiation-associated gene 5–positive dermatomyositis (MDA5 DM) is a rare but distinct subtype of idiopathic inflammatory myopathy (IIM) that is characterized by high mortality due to rapid progressive interstitial lung disease (ILD). MDA5 is a cytosolic protein and a family of retinoic-acid inducible gene-I (RIG-I) like receptor, which functions as a virus RNA sensor and induces the production of type I interferons (IFN-I) and proinflammatory cytokines. This leads to the death of infected cells and the activation of the antigen-specific antiviral immune response. Although the pathogenesis of MDA5 DM is largely unknown, a hypothesis that pathogenic involvement of anti-MDA5 antibodies has been proposed. Recently, similarities have been noted between multifaceted features of COVID-19 and MDA5 DM, which suggests shared underlying autoinflammatory mechanisms.

Objectives

To detect the critical actors in the pathogenesis of MDA5 DM by gene expression analysis of peripheral blood.

Methods

Total of 31 DM cases were investigated, including anti-aminoacyl-tRNA synthetase positive (ARS) DM (n=12), MDA5 DM (n=7, survivor=3) and others (n=12). Peripheral blood was drawn at baseline and 2 to 3 months after treatments. Total RNAs were then extracted with using PAXgene miRNA kit. After quantifying the expressions of transcripts by multiplex sequencing. And then, hierarchical clustering analysis, enrichment analysis using gene ontology (GO) terms, single sample gene set enrichment analysis (ssGSEA) and weighted gene co-expression network analysis (WGCNA) were performed.

Results

The hierarchical clustering with expression profiles of peripheral blood at baseline showed major 3 clusters. Interestingly, ARS DM cases were segregated into right side of the 3rd cluster while MDA5 DM cases fell into 1st and 2nd clusters. ARS and MDA5 DM were clearly discriminated if differentially expressed genes (DEGs) between these subtypes of DM were analyzed. By GO enrichment analysis, the terms, such as related to “defense response to virus” including “type1 interferon signaling pathway” were found in the DEGs. In the MDA5 DM cases, ssGSEA revealed that genes of “Fcγ receptor mediated phagocytosis pathway” or “complement and coagulation cascade” were significantly enriched and WGCNA showed that pathways of “T-cell antigen receptor signaling” or “lung fibrosis” were significantly upregulated. Next, we also investigated the DEGs of peripheral blood at 2-3 months after treatment between survival and fatal cases in MDA5 DM. We found that suppressing RIG-I like receptor and type 1 and type 2 interferon (IFN) signaling were the keys for survival.

Conclusion

MDA5 is a key sensor of several RNA viruses including coronavirus families and then activate antiviral gene transcription such as type 1 IFN genes, leading to establish an antiviral host response. As the pulmonary damage of COVID-19 is known to be difficult to distinguish from the ILD associated with anti-MDA5 DM, the life-threating ILD of MDA5 DM may be caused by the over-activation of RIG-I like receptor signaling via MDA5. The hypothesis is supported by our findings that the defining features of MDA5 DM are activation of “type 1 IFN pathways” and antigen-specific antiviral immune responses including “Fcγ receptor mediated phagocytosis pathway” or “T-cell antigen receptor signaling”. As the levels of anti-MDA5 antibodies reported to be important prognostic parameter, it may be involved in pathogenesis of MDA5 DM. As we found that suppression of type 1 and type 2 IFN signaling were the keys for survival, it seems to be reasonable to use inhibitors of Janus Kinases (JAK) for treatment of MDA5 DM.

Disclosure of Interests

Yoshinobu Koyama Speakers bureau: Abbvie, Asahikasei, Ayumi, BMS, Eli-Lilly, Mitsubishi Tanabe, Grant/research support from: Abbvie, GSK, Yoshiharu Sato: None declared, Moe Sakamoto: None declared

Breast milk contribution to tissue mercury levels in rat pups examined by cross-fostering at birth

The developing perinatal brain is vulnerable to methylmercury (MeHg) exposure. The contribution of breast milk to tissue MeHg levels in offspring is a significant public health concern because breast milk contains a certain amount of MeHg. Here, the contribution of MeHg transferred via breast milk to the Hg levels in the tissues of pups (Wistar rats) was investigated. Mated maternal rats were fed a MeHg (2 ppm)-supplemented or a control diet during pregnancy. Following parturition, male neonates from each group were cross-fostered between exposed or control dams, and they were further raised by dams fed a MeHg-supplemented diet or a control diet during lactation. Consequently, we evaluated three pup groups, which were raised by dams exposed to MeHg during pregnancy (P pups), lactation (L pups), or pregnancy and lactation (PL pups). Total mercury (THg) concentrations in the tissues of the offspring were measured at birth (postnatal day 0 [PD0]), during lactation (PD6, PD12, and PD19), and after weaning (PD29 and PD36). Blood and brain THg levels in the P and PL pups declined dramatically during lactation, however, there were no considerable differences between the two groups at PD6 and PD12. In contrast, blood and brain THg levels in the L pups increased slightly during lactation. The increase in the THg levels in the blood and brain of L pups at PD12 were approximately 3.3% and 1.5%, respectively, compared to the corresponding THg levels in the neonates in the P and PL groups. Our results suggest that if the MeHg exposure level during pregnancy is not high enough to cause neuronal development defects in the fetus, the exposure via breast milk is not a significant concern.

Organ-specific accumulation of selenium and mercury in Indo-Pacific bottlenose dolphins (Tursiops aduncus)

Delphinids are top ocean predators and accumulate high concentrations of mercury (Hg) through the food chain, particularly in organs such as liver and kidney, although the proportion of methylmercury (MeHg) is relatively low due to the demethylation process. Total mercury (T-Hg) levels in marine mammals have been shown to correlate with selenium (Se) concentrations, and ingested MeHg that is demethylated may be present in tissues as mercury selenide (HgSe). In this study, we determined T-Hg, MeHg and Se concentrations of three Indo-Pacific bottlenose dolphins (Tursiops aduncus), and we used the individual with the highest Hg concentration for electron probe microanalysis to assess the co-localization of Hg and Se in the tissues. By electron probe microanalysis, we found that Hg and Se were co-localized in large granules in hepatic Kupffer cells and in small granules in hepatocytes. The analysis suggested that MeHg was demethylated in hepatocytes and then phagocytosed by Kupffer cells. In the kidney, Hg and Se were co-localized in the glomerular capillary wall and in interstitial blood vessel walls. Hg and Se were also co-localized in the cytoplasm of large neurons and in glial cells in the cerebrum. Divalent Hg and HgSe cannot cross the blood-brain barrier, suggesting that MeHg is demethylated in the dolphin brain and that binding to Se suppresses Hg toxicity.

Changes in immune system and intestinal bacteria of cows during the transition period

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Transitional high-energy diets reduce peripheral blood lymphocytes in dairy cows.

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High-energy diets upregulate IL-1β and IL-2 and downregulate IL-10 expression.

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Functional lactobacillus plantarum LP1 restores normal levels of lymphocytes subset.

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Lactobacillus plantarum LP1-added diets reduce inflammatory cytokine expression.

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LP1 mitigates immune response imbalances caused by transitional high energy diets.

High-yield dairy cows need high energy feed during periods of increased milk production. The transitional feeding to high energy feed increases the risk of developing a variety of metabolic disorders. Here, five Holstein cows were fed a four-stage feeding protocol (3 weeks for each stage) ranging from 54.9 to 73.7% total digestive nutrients (TDN). The purpose of the study was to investigate the effect of lactic acid bacteria on high-energy-fed cows associated with transitional feeding, and to evaluate the effects of probiotics on intestinal bacterial changes and inflammatory responses. Three feed transition periods were established for five cows, and Lactobacillus plantarum RGU-LP1 (LP1) was fed as a probiotic during the high-energy feeding period. The number of lymphocyte subsets such as CD3-, CD4-, and CD8 positive cells decreased in response to the high energy feed. Lipopolysaccharide (LPS)-induced cytokine (IL-1β and IL-2) gene expression in peripheral blood mononuclear cells (PBMCs) was shown to increase in those animals receiving the high energy feed. However, supplementation with LP1 resulted in an increase in the number of lymphocyte subsets and the expression of IL-1β and IL-2 were returned to the level at low energy diet. These results suggest that high energy diets induce inflammatory cytokine responses following LPS stimulation, and that the addition of LP1 mitigates these results by regulating the LPS-induced inflammatory reaction. Therefore, the functional lactic acid bacteria LP1 is expected to regulate inflammation resulting from high energy feeding, and this probiotic could be applied to support inflammatory regulation in high-yield dairy cows.

Prognostic grade for resecting hepatocellular carcinoma: multicentre retrospective study

BACKGROUND

Surgical treatment for hepatocellular carcinoma (HCC) is advancing, but a robust prediction model for survival after resection is not available. The aim of this study was to propose a prognostic grading system for resection of HCC.

METHODS

This was a retrospective, multicentre study of patients who underwent first resection of HCC with curative intent between 2000 and 2007. Patients were divided randomly by a cross-validation method into training and validation sets. Prognostic factors were identified using a Cox proportional hazards model. The predictive model was built by decision-tree analysis to define the resection grades, and subsequently validated.

RESULTS

A total of 16 931 patients from 795 hospitals were included. In the training set (8465 patients), four surgical grades were classified based on prognosis: grade A1 (1236 patients, 14.6 per cent; single tumour 3 cm or smaller and anatomical R0 resection); grade A2 (3614, 42.7 per cent; single tumour larger than 3 cm, or non-anatomical R0 resection); grade B (2277, 26.9 per cent; multiple tumours, or vascular invasion, and R0 resection); and grade C (1338, 15.8 per cent; multiple tumours with vascular invasion and R0 resection, or R1 resection). Five-year survival rates were 73.9 per cent (hazard ratio (HR) 1.00), 64.7 per cent (HR 1.51, 95 per cent c.i. 1.29 to 1.78), 50.6 per cent (HR 2.53, 2.15 to 2.98), and 34.8 per cent (HR 4.60, 3.90 to 5.42) for grades A1, A2, B, and C respectively. In the validation set (8466 patients), the grades had equivalent reproducibility for both overall and recurrence-free survival (all P < 0.001).

CONCLUSION

This grade is used to predict prognosis of patients undergoing resection of HCC.

POS0881 DETECTION OF THE GENE EXPRESSIONS IN PERIPHERAL BLOOD INVOLVED IN THE PROGRESSION OF PULMONARY VESSEL DISEASE AT THE SUBCLINICAL STAGE OF PULMONARY HYPERTENSION ASSOCIATED WITH SYSTEMIC SCLEROSIS

Background:

Pulmonary hypertension (PH) is prominent as a vascular involvement of systemic sclerosis (SSc), which remains a leading cause of death in spite of current best treatments. Recently, hemodynamic definition of PH was updated from mPAP≥25mmHg to mPAP>20mmHg and PVR≥3WU. Although new definition may improve the prognosis of PH associated with SSc by giving a chance to start management early, it may be insufficient as more than 2/3 of the pulmonary circulation is already impaired by the time of meeting the definition. Therefore, the ideal therapeutic intervention should be started at the subclinical stage of PH in SSc patients, but little is known about underlying pathological mechanisms at the stage. In this study, we investigate progression to exercise-induced PH (exPH)1), which is considered subclinical PH, in the prospective registry of high-risk population for developing PH associated with SSc.

Objectives:

To detect the gene expressions in peripheral blood involved in the progression of pulmonary vessel disease (PVD) at the subclinical stage of PH associated with SSc.

Methods:

Total of 180 patients who had not met PH criteria with Raynaud phenomenon, skin sclerosis or SSc-related autoantibody was registered. To detect the early PVD, exercise Doppler echocardiography (exDE) was carried out every 6 or 12 months for up to 6 years. The definition of exPH was maximum sPAP>40mmHg or increase in sPAP>20mmHg estimated by exDE during exercise. For gene expression analysis, total RNAs from whole peripheral blood cells were extracted by PAXgene system, and then multiplex sequencing was done. To identify candidate genes involved in the progression to exPH, random forest machine learning method was employed. Volcano plots, a scatter plots to visualize fold-changes and p-values of differentially expressed genes (DEGs) between exPH and others (exN), were also used for seeking the important genes for disease progression.

Results:

At the time of registration, 34.4% of patients met exPH criteria, and 15.6% of patients developed exPH during follow-up period (35.0±18.1 months). Expression of TNF gene was selected as the most useful genes to predict progression to exPH by random forest, and the accuracy of the model was about 87%. Volcano plots indicated that expressions of TMEM176A and TMEM176B were prominent (fold-change >2.4 and -log10 p-value >3.5) in exPH patients. The accuracy was improved to 90% if the expression of TNF and TMEMA/B were used for the prediction of progression to exPH. We found that statistically significant increase in the expression of TNF was eliminated at the time of fulfilling the exPH criteria, while increase in expressions of TMEM A/B were still kept.

Conclusion:

It was reported that TNFα drives pulmonary arterial hypertension by suppressing the BMP type-II receptor and altering NOTCH signalling2). Our findings suggest that TNFα plays important role only in the period of pre-exPH. On the other hand, increase in expressions of TMEM A/B were observed through the period of pre-exPH to post-exPH. It suggests that there are multiple phases before developing PH associated with SSc. It is very important to understand the phases for the precise treatment to arrest the progression of PVD.

References:

[1]R. Naeije et al., Am J resp and critical care med 187, 576-583 (2013). 2) LA. Hurst et al., Nat Commun. 13;8:14079 (2017).

Disclosure of Interests:

Yoshinobu Koyama Speakers bureau: Asahikasei, Ayumi, BMS, Mitsubishi Tanabe, Shin-nihon, Paid instructor for: Asahikasei, Asteras, BMS, Grant/research support from: Eli-Lilly, Yoshiharu Sato: None declared, Tatsuma Shoji: None declared, Soichiro Fuke: None declared, Takatsune Umayahara: None declared, Moe Sakamoto: None declared

Plasma and red blood cells distribution of total mercury, inorganic mercury, and selenium in maternal and cord blood from a group of Japanese women

Fetuses are a high-risk group for methylmercury (MeHg) exposure. The main objective of this study was to compare the characteristic profiles of total mercury (THg), inorganic mercury (IHg), MeHg, and selenium in plasma and red blood cells (RBCs) between maternal and cord blood at parturition collected from a group of Japanese women. Furthermore, correlations of THg in RBCs, which is a biomarker of MeHg, and THg in plasma, which is an IHg exposure biomarker, were examined in maternal and cord blood. Fifty-five pairs of maternal and cord blood samples obtained at parturition were collected from pregnant women in Fukuoka, Japan. THg in RBCs and plasma were significant correlated between maternal and cord blood. THg in RBCs was 13.9 ng/mL for cord and 9.16 ng/mL for maternal blood, with a cord:maternal RBCs ratio for THg of 1.58, suggesting that MeHg is actively transferred from the mother to the fetus via the placenta. THg in plasma showed a positive correlation with THg in RBCs for maternal and cord blood. This result suggests that measuring THg in plasma can overestimate the exposure level to IHg in fish-eating populations. The percentages of IHg in cord plasma and RBCs were 31% and 1.7%, respectively, and those in maternal plasma and RBCs were 46% and 5.9%, respectively. These results suggest that cord blood is rich in MeHg and can easily transfer to the fetal brain. Selenium in cord plasma was 67 ng/mL and that in maternal plasma was 97 ng/mL, with a cord:maternal plasma ratio for Se of 0.69, suggesting that the protective effects of Se against MeHg toxicity in fetuses may be weaker than those expected in adult mothers.

Measurement of axial phase difference of density fluctuations owing to spontaneously excited waves by using microwave reflectometer on GAMMA 10/PDX

In the GAMMA 10/PDX tandem mirror, plasma with strong ion-temperature anisotropy is produced by using the ion cyclotron range of frequency waves. This anisotropy of ion temperature causes several Alfvén-Ion-Cyclotron (AIC) waves to spontaneously excite in the frequency range just below the ion cyclotron frequency. In addition, difference-frequency (DF) waves are excited in the radial inner region of the plasma by wave-wave coupling among the AIC waves. The radial density profiles were measured at multi-axial positions using a frequency-modulation reflectometer with an axial array of microwave antennas, and an axial variation of the density was found to be significant. In addition, a relative phase difference of the DF wave between axially separated two points was first obtained by finely choosing the probing frequency of the reflectometers with a maximum coherence used as a measure, indicating that the DF wave is a propagating wave, while the pump AIC waves are standing waves in the axial region of measurement.

Improvement in multipass Thomson scattering system comprising laser amplification system developed in GAMMA 10/PDX

The multipass Thomson scattering (MPTS) technique is one of the most useful methods for measuring low-electron-density plasmas. The MPTS system increases Thomson scattering (TS) signal intensities by integrating all multipass (MP) signals and improving the TS time resolution by analyzing each pass signal. The fully coaxial MPTS system developed in GAMMA 10/potential-control and diverter-simulator experiments has a polarization-based configuration with image-relaying optics. The MPTS system can enhance Thomson scattered signals for improving the measurement accuracy and megahertz-order time resolution. In this study, we develop a new MPTS system comprising a laser amplification system to obtain continuous MP signals. The laser amplification system can improve degraded laser power and return an amplified laser to the MP system. We obtain continuous MP signals from the laser amplification system by improving the laser beam profile adjuster in gas scattering experiments. Moreover, we demonstrate that more MP signals and stronger amplified MP signals can be achieved via multiple laser injections to the laser amplification system in the developed MP system comprising a laser amplification system.

Mercury and Selenium Localization in the Cerebrum, Cerebellum, Liver, and Kidney of a Minamata Disease Case

Minamata disease is a methylmercury poisoning caused by consumption of marine food contaminated by man-made methylmercury environmental pollution, and its most prominent feature is marked pathological changes in the central nervous system. Morphological alterations are less pronounced in the liver and the kidney, although their mercury levels are higher than those of the brain. In marine mammals, methylmercury is known to be easily converted to inorganic mercury and it combines with selenium forming mercury selenide, which may counteract the toxicity of mercury. However, little is known about the formation of mercury and selenium complex in human organs. In the present study, we examined the cerebrum, cerebellum, liver, and kidney of a Minamata disease case to study the mercury and selenium localization using electron probe microanalysis. Our results indicated the mercury and selenium localization in the specified tissue of the brain, liver, and kidney such as glial cells, Kupffer cells, and renal tubules.

Toxicokinetics of methylmercury in diabetic KK-Ay mice and C57BL/6 mice

We compared the toxicokinetics of methylmercury (MeHg) in KK-Ay type 2 diabetic mice and C57BL/6J mice to evaluate how metabolic changes associated with diabetes affect MeHg toxicokinetics. A single dose of MeHg (0.2, 1, or 5 mg mercury/kg) was administered orally to 12-week-old KK-Ay and C57BL/6J male mice. Total mercury concentrations in plasma, blood cells, whole blood, and tissues (brain, kidneys, liver, and pancreas) were measured after 4, 7, 11, and 14 days. The volume of distribution/bioavailability and the elimination rate constant per day were higher in KK-Ay mice, while the terminal elimination half-life was lower in almost all samples of KK-Ay mice. The area under the curve was lower in all blood and almost all tissue samples from KK-Ay mice. Total clearance/bioavailability was lower in all blood and tissue samples of KK-Ay mice at all MeHg doses. These results indicate that MeHg is more rapidly absorbed by, and eliminated from, the blood cells, brain, liver, kidney, and pancreas of KK-Ay mice under the experimental conditions. Different patterns of tissue-to-plasma and tissue-to-whole blood partition coefficients suggest that notable differences in MeHg transfer between plasma and blood cells affect its distribution in tissues of the two mouse strains. These findings are useful to understand the selective distribution of MeHg to target organs and the sensitivity to MeHg in pathological states.

Prenatal and postnatal lead exposures and intellectual development among 12-year-old Japanese children

BACKGROUND

Low-level lead exposure during childhood is associated with deficit in child IQ. However, the association between prenatal lead exposure and child IQ remains inconsistent. The objective of our study was to examine the association between prenatal/postnatal lead exposure and child IQ at the age of 12.

METHODS

We obtained data pertaining to cord-blood and child-blood lead levels and IQ for 286 children from a prospective birth cohort study (Tohoku Study of Child Development). IQ was assessed using the Wechsler Intelligence Scale for Children-Fourth Edition. Simultaneously, the Boston Naming Test (BNT) was used to assess the children's language ability.

RESULTS

The median lead level in the cord blood was 0.8 μg/dL (5th-95th percentiles, 0.4-1.4 μg/dL), and that in the blood of 12-year-old children was 0.7 μg/dL (0.4-1.1 μg/dL). IQ and BNT scores were significantly lower in boys than in girls; therefore, multiple regression analysis was conducted separately for boys and girls. Among boys, IQ was associated with child-blood lead (B = -16.362, p = 0.033) but not cord-blood lead (B = -6.844, p = 0.309). When boys were divided into four groups according to the child-blood lead levels, there was a significant decreasing trend for IQ. The score with cues of the BNT was associated with both cord-blood (B = -5.893, p = 0.025) and child-blood (B = -7.108, p = 0.022) lead concentrations in boys. Among girls, there was no significant association of the outcomes with cord-blood or child-blood lead level.

CONCLUSIONS

These findings suggest that postnatal lead exposure adversely affects the intellectual ability in boys. Furthermore, the language ability is sensitive to prenatal/postnatal lead exposure in boys.

Extracorporeal high-pressure therapy (EHPT) for malignant melanoma consisting of simultaneous tumor eradication and autologous dermal substitute preparation

Surgical resection of skin tumors leads to large defects in surrounding normal tissues, which should be reconstructed thereafter using the patient's own tissues taken from the other site. Our challenge is to solve this problem in dermal malignant melanoma (MM) by a novel process, named extracorporeal high pressure therapy (EHPT), in which the tissue containing tumor is resected and pressurized, and the treated tissue is re-transplant back to the same position as a tumor-free autologous dermal substitute. The key points are complete tumor death and preservation of native extra cellular matrix (ECM) by the hydrostatic pressure. We found that high hydrostatic pressure at 200 MPa for 10 min at room temperature is completely cytocidal against MM cells in suspension form, in monolayer form, and even in the solid tumor form. MM tumor-bearing nude mice were established by injected human MM cells intradermally and treated by EHTP. The denaturation of the dermal extra cellular matrices was so mild that the pressurized skin was well engrafted as tumor free autologous dermal tissues, resulting in the complete eradication of the MM without any unnecessary skin reconstruction surgery. This very simple and short pressing treatment was proved to make the tumor tissue to the transplantable and tumor-free autologous dermal substitute, which can be applicable to the other temporally resectable tissues.

Methylmercury exposure during the vulnerable window of the cerebrum in postnatal developing rats

The developing brain is known to be sensitive to the toxic effects of methylmercury (MeHg). The effects of toxic levels of MeHg exposure during the most seemingly vulnerable window of the cerebrum are not well studied. In this study, we aimed to examine the specific effects of toxic levels of MeHg on neurobehavior, neurodegeneration, and selenoenzyme activity in the cerebrum of infant rats. Male Wistar rats (n = 8/group) were orally treated with MeHg at an acute toxic dose (8 mg Hg/kg/day) for 10 consecutive days starting on postnatal day 14 (P14). The MeHg-exposed rats showed a significant reduction in body weight after day 8 and severe neurological symptoms similar to dystonia on day 12 (P25). Motor coordination deficits determined using the rotarod performance test and short-term memory impairment determined using the Y-maze task were observed in the MeHg-exposed rats on day 11 (P24). The MeHg-exposed rats sacrificed on day 12 showed severe cerebral neuronal degeneration, reactive astrocytosis, and TUNEL-positive apoptotic nuclei, with the cerebral Hg concentration of 15.0 ± 1.6 μg/g. Furthermore, the activities of glutathione peroxidase and thioredoxin reductase in the cerebrum in MeHg-exposed rats were lower than those in control. These results indicate that MeHg exposure to infant rats will be useful to predict the effects of MeHg at the cerebral growth spurt in humans.

Anatomic characterisation of the parietal branches arising from the internal iliac artery in the foetal pig (Sus scrofa domestica)

BACKGROUND

It is critical for surgeons to have a full understanding of the complex courses and ramifications of the human internal iliac artery and its parietal branches. Although numerous anatomical studies have been performed, not all variations at this site are currently understood. Therefore, we characterised these blood vessels in foetal pigs to provide additional insight from a comparative anatomical perspective.

MATERIALS AND METHODS

Eighteen half-pelvis specimens from foetal pigs were dissected and examined on macroscopic scale.

RESULTS

Among our findings, we identified the internal iliac artery as a descending branch of the abdominal aorta. A very thick umbilical artery arose from the internal iliac artery. The superior gluteal, inferior gluteal, and internal pudendal arteries formed the common arterial trunk. Although the superior gluteal artery emerged from the common trunk from inside the pelvis, the inferior gluteal and internal pudendal arteries bifurcated at deep layer within the gluteus muscles after leaving pelvic cavity. We were unable to detect an typical obturator artery emerging from the internal iliac artery. A branch supplying the hip adductors was identified as arising from the inferior epigastric artery which itself was derived from the distal end of the external iliac artery.

CONCLUSIONS

We identified the anatomic characteristics of the internal iliac artery and its parietal branches in the foetal pig. Our findings provide new insight into the comparative anatomy of the internal iliac artery and will promote understanding of related morphogenetic processes.

SAT0119 PARADOXICAL NEUTROPHIL ACTIVATION BY ANTI-IL6 THERAPY: TRANSCRIPTOME ANALYSIS SHOWS A RATIONALE FOR DERMATOLOGICAL ADVERSE REACTIONS AND DECREASED NEUTROPHIL COUNTS AFTER TOCILIZUMAB TREATMENT

Background:

Skin rashes as a side effect of Tocilizumab therapy (TCZ- Tx) has not been paid much attention, because the incidence was only 1~2% in the drug information sheets. However, we experienced several RA cases with development of various skin rashes associated with neutrophil activation after TCZ-Tx. On the other hand, it is well known that the neutrophil counts in peripheral blood decreases after TCZ-Tx, whereas it does not affect the rate of serious infections. The detailed mechanism is still unclear.

Objectives:

To detect the characteristics of the changes in gene expressions of peripheral blood associated with TCZ-Tx and the development of skin rashes as its side effect.

Methods:

Total of 14 RA patients with TCZ-Tx were included. Among them, 4 patients developed TCZ-related rashes (group S) and 10 patients did not show any side effects (group C). Peripheral whole blood at just before (pre) and 3 months after (post) TCZ-Tx from each patient were subjected to the analysis. Total RNAs were extracted with PAXgene miRNA kit and analyzed with next-generation sequencing. First, group C was investigated for the normal response to TCZ-Tx. Differentially expressed genes (DEGs) were selected by paired comparison (post vs. pre). And then, enrichment analysis using gene ontology (GO) terms were performed. Second, to explore the characteristics of group S, all expressed genes in 14 cases at just before TCZ-Tx were subjected to a hierarchical clustering analysis. The DEGs (group S vs. C and post vs. pre) were also investigated with weighted gene co-expression network analysis (WGCNA) and GO analysis. Meanwhile, the total eigengene expressions of the important modules identified by WGCNA in each cases were also calculated.

Results:

Surprisingly, 8 out of the top 10 enriched GO terms in the up-regulated genes were relevant to leukocyte activation such as ‘neutrophil migration” by the analysis of DEGs (post vs. pre) in group C. The cluster analysis of ‘pre’ genes confirmed that the patterns of gene expression between group S and C was different. WGCNA analysis of DEGs (group S vs. C) revealed that genes related to acute inflammation such as ‘leukocyte mediated immunity’ were activated in group S. Interestingly, it was not correlated with disease activity score (DAS) of RA. By the analysis of DEGs (post vs. pre) of upregulated genes, we found that the total eigengene expressions of the module enriched with genes related to ‘cell adhesion’ or ‘leukocyte migration’ were significantly increased in all cases of group S.

Conclusion:

This is the first evidence that the genes associated with neutrophil migration is significantly activated after TCZ-Tx. It is noteworthy that the gene activation was observed in cases without any side effects. The decreased neutrophil counts in peripheral blood have been known after initiation of TCZ-Tx, which did not affect the rate of serious infections. Recently, It was reported that TCZ affects neutrophil trafficking to the bone marrow1). Our findings will provide a rationale for its cause. On the other hand, we experienced several RA cases with development of various skin rashes associated with neutrophil activation after TCZ-Tx. However, majority of patients do not develop the side effect, even though genes related to ‘neutrophil migration’ are activated. In group S, our findings indicate that the genes related to ‘leukocyte mediated immunity’ was already activated at the initiation of treatment without correlating to DAS of RA, furthermore, the gene upregulation related to ‘leukocyte migration’ was more prominent after TCZ-Tx. Although it is difficult to predict the patients developing skin rashes before TCZ-Tx, we do not recommend to use TCZ for the patients with neutrophilic dermatosis which is often associated with RA.

References: :

[1]Lok LSCet al.,Eur J Clin Invest. 47(10):736-745 (2017).

Disclosure of Interests: :

Moe Sakamoto: None declared, Akemi Senoh: None declared, Yoshiharu Sato: None declared, Hiroshi Iijima: None declared, Mari Yamaguchi: None declared, Toshie Higuchi: None declared, Yoshinobu Koyama Grant/research support from: Eli-Lilly and Mochida., Speakers bureau: BMS, Ayumi, Chugai, Ono, Mitsubishi Tanabe, Abbvie and Eisai.

THU0208 AFFECTING COMMON BIOLOGICAL PROCESSES OR DISPARATE?: COMPARISON OF GENE-EXPRESSION MODIFICATION PROFILES AMONG TARGETING IL-6 AND TARGETING SPECIFIC JAK TREATMENTS

Background:

After accumulation of evidences, it is recognized that inhibition of IL-6 signaling is one of the most established strategies for rheumatoid arthritis (RA) treatment. Tocilizumab (TCZ), an anti-IL6 receptor monoclonal antibody, is the pioneer which blocks IL-6 signaling by preventing IL-6 from binding to both membrane-bound and soluble receptors. Tofacitinib (TOF) inhibits Janus kinase (JAK) 1, JAK3 and, to a lesser extent, JAK2. Recently, Baricitinib (BAR), JAK 1 and JAK2 selective kinase inhibitor, were also approved to treat RA. These JAK inhibitors are known to inhibit cytokine signaling including interleukin (IL)-6. It is very important for clinicians to know whether these treatments affect common biological processes or disparate, because it will provide a rationale for switching each other if one of these treatments resulted in lack of efficacy.

Objectives:

To compare the gene-expression modification profiles among TOF, BAR and TCZ treatments.

Methods:

Total of 38 RA cases were analyzed, including TOF (n=15: 6-20mg/d), BAR (n=10: 2-4mg/d) and TCZ (n=13: 8mg/kg/4w or 163mg/2w) treatment groups. Peripheral blood was drawn at just before (pre) and 3 months after (post) these treatments. Total RNAs were then extracted with using PAXgene miRNA kit. After constructing single-stranded, strand-specific libraries, multiplex sequencing was done. After quantifying the expressions of transcripts, differentially expressed genes (DEGs) were selected by paired comparison (post vs. pre), setting thresholds at 2-fold change up/down and less than P=0.05 in paired T-test. And then, hierarchical clustering analysis and enrichment analysis using gene ontology (GO) terms were performed.

Results:

From the comparison of post- vs. pre-treatment of TOF, BAR and TCZ, the 120 (up-regulated=25/down-regulated=95), 62 (up=20/down=42) and 193 (up=54/ down=139) genes were selected as DEGs respectively. It seems to be discrete depending on the treatment, because overlapped genes were only 1.0% in up-regulated and 5.7% in down-regulated genes. The hierarchical clustering with expression profiles of these DEGs showed major 4 clusters. 92.3% of TCZ and 70% of BAR cases were segregated into 1stand 3rdclusters respectively, while those of TOF cases fell into 2ndand 4thclusters. Disparate GO terms were enriched in each DEGs group. For example, genes relevant to viral defense including ‘response to type I interferon (IFN)’ were suppressed in TOF group. Meanwhile, down regulation of genes involved in phosphorylation process including ‘IL-7 signaling’ seemed to be significant in BAR group. It is noteworthy that terms related to wound healing such as ‘platelet activation’ were enriched in the down-regulated genes of TCZ group.

Conclusion:

It is speculated that the downstream biological cascade for TOF, BAR and TCZ treatment might be shared, as IL-6 signaling is mediated by JAK1/JAK2/TYK2 activation. However, the influence of these treatments over the transcriptome in the peripheral blood seems to be disparate. Enrichment analysis using GO terms also indicated that different biological processes were involved in the effect of each treatment. Our findings will support a rationale for switching each other if one of these treatments resulted in lack of efficacy. An increased risk of herpes zoster by a treatment with JAK inhibitors has been well recognized. It makes sense because IFN signaling is also mediated by JAK/STAT pathway. On the other hand, we have experienced a case with exacerbation of skin ulcer during TCZ treatment despite the activity of RA was absolutely under control. It is accounted for by the suppression of genes involved in wound healing after TCZ treatment.

Disclosure of Interests: :

Yoshinobu Koyama Grant/research support from: Eli-Lilly and Mochida., Speakers bureau: BMS, Ayumi, Chugai, Ono, Mitsubishi Tanabe, Abbvie and Eisai., Yoshiharu Sato: None declared, Moe Sakamoto: None declared, Hiroshi Iijima: None declared, Toshie Higuchi: None declared

Development of Human Hair Reference Material Supporting the Biomonitoring of Methylmercury

A certified reference material, NIMD-01, was developed for the analysis of mercury speciation in human hair. We collected the hair of Vietnamese males from a barbershop in Hanoi in 2016 and prepared 1200 bottles containing 3 g of sieved and blended hair powder. The certified value was given on a dry-mass basis, with the moisture content obtained by drying at 85°C for 4 h. Certified values with the expanded uncertainties (coverage factor, k = 2) were as follows: methylmercury, 0.634 ± 0.071 mg kg^-1 as mercury; total mercury, 0.794 ± 0.050 mg kg^-1; copper, 12.8 ± 1.4 mg kg^-1; zinc, 234 ± 29 mg kg^-1; selenium, 1.52 ± 0.29 mg kg^-1. An indicative arsenic concentration of 0.17 ± 0.03 mg kg^-1 was measured. Extended uncertainties were estimated by sample homogeneity, long- and short-term stabilities, and a characterization from measurements made by collaborating laboratories.

Mercury speciation in preserved historical sludge: Potential risk from sludge contained within reclaimed land of Minamata Bay, Japan

In the latter half of the 1950s, a large amount of methylmercury (MeHg) was discharged directly into Minamata Bay, Japan by a chemical factory, resulting in the contamination of the fish and shellfish. Ultimately, an outbreak of MeHg intoxication, called Minamata disease, occurred. From 1977 to 1988, the Kumamoto Prefectural Government dredged and transferred sediments exceeding 25 μg/g of total mercury (THg, dry basis) into a strictly segregated area of the bay near the wastewater outlet, then this area was landfilled. We conducted analyses of the mercury speciation in preserved Minamata Bay sludge samples (collected from inside of the bay prior to the termination of the remediation project; n=4) and recent Minamata Bay sediments (collected outside the dredging area of the bay; n=5) to evaluate the potential risk of the sludge/sediment leakage from the reclaimed land to the Minamata Bay. Median THg (dry basis) concentrations were 241 μg/g for the preserved sludge, 6.1 μg/g for the recent Minamata Bay sediments, and 0.18 μg/g for a single control sample; median MeHg concentrations (percentage of MeHg in THg) were 108 ng/g (0.031%), 3.7 ng/g (0.12%), and 0.71 ng/g (0.41%), respectively. In all the samples, the MeHg% decreased exponentially with increasing THg concentration. The extractability of THg from each sample into seawater was shown to be much lower than that of MeHg. The extracted MeHg was 0.86% for the preserved sludge, 4.57% for the recent Minamata Bay sediments, and 7.89% for the control. The predominant chemical form of mercury in the preserved sludge containing the highest THg concentration was found to be stable β-mercury sulfide (HgS) based on transmission electron microscopy linked with energy-dispersive X-ray spectroscopy (TEM-EDX) and X-ray absorption fine structure (XAFS) analyses.

P6332Prevalence and prognostic impact of sarcopenia identified according to Asia Working Group for Sarcopenia definition in non-dependent elderly patients with heart failure

Background

Sarcopenia is a geriatric syndrome characterized by loss of muscle mass and muscle function. As the population ages, there is a growing worldwide interest in the intersection of sarcopenia and heart failure (HF). However, estimates of the prevalence of sarcopenia in HF vary widely because of difference in diagnostic criteria. Although the Asian Working Group of Sarcopenia (AWGS) has announced a consensus on the diagnostic criteria of sarcopenia in Asian people, the prevalence and prognostic impact of sarcopenia based on AWGS criteria in patients with HF remains unclear.

Purpose

The aim of this study was to investigate the prevalence and predictive value of sarcopenia identified according to AWGS definition in non-dependent elderly patients with HF.

Methods

This study was a prospective, single-center cohort study in Japan. We consecutively enrolled 274 patients, aged 65 years or older, hospitalized due to acute HF or acute exacerbation of chronic HF and who were able to walk at least 20 m at discharge. Patients with severe cognitive or psychiatric disorders were excluded. Patients with implantable cardiac pacemaker or cardioverter defibrillator were also excluded because skeletal muscle mass was estimated by using bioimpedance analysis. At hospital discharge, we collected data on age, gender, left ventricular ejection fraction, brain natriuretic peptide, estimate glomerular filtration rate, body mass index and sarcopenia. Sarcopenia was diagnosed according to the AWGS criteria: low skeletal muscle index (<7.0 kg/m2 in men, <5.7 kg/m2 in women) and either slow usual walking speed (<0.8 m/s) or low handgrip strength (<26 kg in men, <17 kg in women). Study outcome was rehospitalization for worsening HF within 180 days after discharge. We assessed the independent association between sarcopenia and HF rehospitalization by using multivariate Cox proportional hazards regression analysis.

Results

In this study, a total of 199 patents (43.4%) fulfilled sarcopenia criteria at discharge. During follow-up, 57 patients (20.8%) readmitted for HF. Kaplan-Meier survival curves showed that patients with sarcopenia had significantly lower event-free survival than those without sarcopenia (Figure). After adjusting for other prognostic factors, sarcopenia was independently associated with HF rehospitalization (hazard ratio: 2.31, 95% confidence interval: 1.20–4.53).

Conclusion

Based on AWGS criteria, sarcopenia is highly prevalent even among non-dependent elderly HF patients, and is an independent strong predictor of rehospitalization for worsening HF. AWGS criteria for sarcopenia may be useful for risk prediction in HF.

Efficacy, Immunogenicity, and Safety of a 9-Valent Human Papillomavirus Vaccine: Subgroup Analysis of Participants From Asian Countries

Background

A 9-valent human papillomavirus-6/11/16/18/31/33/45/52/58 (9vHPV) vaccine extends coverage to 5 next most common oncogenic types (31/33/45/52/58) in cervical cancer versus quadrivalent HPV (qHPV) vaccine. We describe efficacy, immunogenicity, and safety in Asian participants (India, Hong Kong, South Korea, Japan, Taiwan, and Thailand) from 2 international studies: a randomized, double-blinded, qHPV vaccine-controlled efficacy study (young women aged 16–26 years; NCT00543543; Study 001); and an immunogenicity study (girls and boys aged 9–15 years; NCT00943722; Study 002).

Methods

Participants (N = 2519) were vaccinated at day 1 and months 2 and 6. Gynecological samples (Study 001 only) and serum were collected for HPV DNA and antibody assessments, respectively. Injection-site and systemic adverse events (AEs) were monitored. Data were analyzed by country and vaccination group.

Results

9vHPV vaccine prevented HPV-31/33/45/52/58–related persistent infection with 90.4%–100% efficacy across included countries. At month 7, ≥97.9% of participants seroconverted for each HPV type. Injection-site AEs occurred in 77.7%–83.1% and 81.9%–87.5% of qHPV and 9vHPV vaccine recipients in Study 001, respectively, and 62.4%–85.7% of girls/boys in Study 002; most were mild to moderate.

Conclusions

The 9vHPV vaccine is efficacious, immunogenic, and well tolerated in Asian participants. Data support 9vHPV vaccination programs in Asia.

Clinical Trials Registration

NCT00543543; NCT00943722.

Associations of environmental exposures to methylmercury and selenium with female infertility: A case-control study

BACKGROUND

Methylmercury exposure is a common health risk resulting from daily fish intake. However, studies addressing the link between methylmercury and infertility are limited and also inconsistent. In addition, no previous epidemiological studies have accounted for the interaction between methylmercury and selenium. We aimed to investigate the association between environmental exposures to metals and female fertility.

METHODS

This case-control study included 98 infertile women receiving fertility treatment (infertile group) and 43 female workers in their thirties (control group) who provided blood samples and returned a questionnaire on lifestyles and dietary characteristics. Blood levels of mercury, lead, cadmium, arsenic, manganese, zinc, and selenium were compared between the groups. Spearman correlation analyses between anti-Müllerian hormone and the metals were conducted.

RESULTS

The mean selenium level in blood (± SD) and the selenium/mercury molar ratio were significantly lower in the infertile group (189 ± 25 μg/L and 94.6 ± 44.3, respectively) than in the control group (200 ± 25 μg/L and 118.4 ± 70.5). By contrast, blood mercury levels after adjusting for blood selenium and age were significantly higher in the infertile group than in the control group. Multiple logistic regression analyses with the adjustment for the other metals and potential confounders confirmed significant associations of infertility with elevated mercury and reduced selenium levels. No significant correlations were observed between anti-Müllerian hormone and metals.

CONCLUSIONS

Methylmercury and selenium exposures appear to have adverse and protective effects on female fertility, respectively. This is the first report to suggest the antagonistic interaction between methylmercury and selenium in relation to human female fertility.

Self-Feeding Ability as a Predictor of Mortality Japanese Nursing Home Residents: A Two-Year Longitudinal Study

OBJECTIVES

To examine the ability of different elements of the Self-Feeding Assessment Tool for Elderly with Dementia (SFED) to predict mortality risk in nursing home residents.

DESIGN AND SETTING

Data from 387 residents in five nursing homes for the elderly in Japan were obtained using a baseline survey. This measure's ability to predict mortality risk was examined over a two-year observation period. Participants and Measurement: Demographic information (sex, age, height, weight, medical history) on 387 initial participants was gathered. A total of 10 individuals were excluded from the analysis because of the inability to eat by mouth at baseline, while 36 were excluded owing to missing mortality data during the observation period. The resulting 341 residents were divided into a death group or survival group according to whether they were still alive after two-year observation period. In addition to basic information and the SFED, the baseline survey included the Barthel Index (BI), Clinical Dementia Rating (CDR), and Mini Nutritional Assessment-Short Form (MNA®-SF). The ability of SFED to predict time-to-event mortality was examined using Cox proportional hazards regression analysis, including other measures associated with mortality as confounding variables.

RESULTS

In total, 129 participants (37.8%) died during the observation period, and their mean SFED score was significantly lower than that of surviving ones (11.1 ± 6.7 vs. 15.0 ± 5.6, P<0.001). SFED score was significantly associated with two-year mortality in the Cox proportional hazards regression analysis after adjusting for sex, age, medical history, BI, CDR, and MNA®-SF (hazard ratio = 0.941, 95% confidence interval = 0.898-0.985, P = 0.010). Additionally, three SFED categories were significantly associated with mortality risk: movement ("able to eat without dropping food"), concentration ("able to maintain attention to meal"), and safety ("able to swallow without choking, with no change in vocal quality after eating").

CONCLUSIONS

Self-feeding ability as measured by SFED score was associated with long-term mortality in elderly living in nursing homes. Accordingly, adjusting feeding assistance based on regular SFED-based assessments may help maintain self-feeding ability and enhance quality of life in this population, as well as providing evidence for end-of-life care options and greatly improving care quality.

Brain methylmercury uptake in fetal, neonate, weanling, and adult rats

Fetuses and neonates are known to be highly susceptible to methylmercury (MeHg) toxicity, but little is known about the relative uptake of MeHg from blood to the developing brain. We measured time-course changes in mercury (Hg) concentrations in the brain of fetal, neonate, weanling, and adult rats after an injection of 0.08 μg (0.4 nmol) Hg/g MeHg. In the prenatal experiment, MeHg was subcutaneously injected to pregnant dams on embryonic days 17, 18, 18.5, 19, 19.5, or 20, and Hg concentrations in tissues were measured in both mothers and fetuses on embryonic day 21 (1 day before parturition). Brain Hg levels in fetuses peaked 2 days after injection and were approximately 1.5 times higher than in mothers. In the postnatal experiment, the same MeHg dose was injected subcutaneously to male rats on postnatal days 1 (neonates), 35 (weanlings), or 56 (adults). Mercury concentrations in tissues were measured 1, 2, 3, 4, 5, or 6 days after the injection. Brain Hg levels peaked most rapidly in neonates, and were approximately 1.5 times higher than levels in weanlings or adults. Throughout the examined period, peak Hg levels in the brain and the Hg brain/blood ratio 24 h after injection were highest in fetuses, followed by the levels in neonates, and decreased with life stage. These findings suggest that relatively higher brain MeHg uptake is an important factor in the vulnerability of fetuses and neonates to MeHg exposure.

[Mercury as a Global Pollutant and Mercury Exposure Assessment and Health Effects]

Mercury and its compounds are classified into three main groups: metallic mercury (Hg⁰), inorganic mercury (Hg²⁺), and organic mercury (methyl mercury: CH₃Hg⁺, etc.). Metallic mercury is the only metal that is liquid at ambient temperature and normal pressure, which readily forms an amalgam with other metals. Therefore, mercury has long been used for refining various metals, and mercury amalgam has been used for dental treatment. Mercury has also been used in measuring instruments such as thermometers, barometers and blood pressure monitors, as well as electric appliances such as lighting equipment and dry batteries. Large amounts of metallic mercury are still used in other countries as a catalyst in the production of caustic soda by electrolysis. In addition, mercury compounds have been used in various chemicals such as mercurochrome, agricultural chemicals, and mildew-proofing agents. However, the use of mercury has also caused health problems for people. Minamata disease in Japan is a typical example. Also, since mercury is highly volatile, it is discharged as a product of industrial activities or derived from volcanoes, and it has been concluded on the basis of the findings of the United Nations Environment Program (UNEP) that it is circulating globally. Therefore, with the aim of establishing an internationally legally binding treaty for the regulation of mercury use to reduce risk, an intergovernmental negotiating committee was established in 2009. Japan actively contributed to this negotiation owing to its experience with Minamata disease, which led to the Convention on the regulation of mercury use being discharged as the "Minamata Convention on Mercury" and the treaty came into force on August 16, 2017. In this review, we introduce 1) the Global Mercury Assessment by UNEP; 2) mercury kinetics, exposure assessment and toxicity of different chemical forms; 3) large-scale epidemics of methylmercury poisoning; 4) methylmercury exposure assessment and health survey in whale-eating populations; 5) elemental mercury exposure assessment and health survey of mercury mine workers in China.

Development of a laser amplification system for the multi-pass Thomson scattering system for GAMMA 10/PDX

The multi-pass Thomson scattering (MPTS) system is a useful technique for increasing the Thomson scattering (TS) signal intensities and improving the TS diagnostic time resolution. The MPTS system developed in GAMMA 10/PDX has a polarization-based configuration with an image relaying system. The MPTS system has been constructed for enhancing the Thomson scattered signals for the improvement of measurement accuracy and the megahertz sampling time resolution. However, in the normal MPTS system, the MPTS signal intensities decrease with the pass number because of the damping due to the optical components. Subsequently, we have developed a new MPTS system with the laser amplification system. The laser amplification system can improve the degraded laser power after six passes in the multi-pass system to the initial laser power. For the first time worldwide, we successfully obtained the continued multi-pass signals after the laser amplification system in the gas scattering experiments.

Effect of genetic polymorphisms of azathioprine-metabolizing enzymes on response to rheumatoid arthritis treatment

Azathioprine (AZA) is increasingly being prescribed to rheumatoid arthritis (RA) patients. Following oral administration, AZA is converted into its active form. Inflammatory bowel disease (IBD) and systemic lupus erythematosus (SLE) patients with low thiopurine (S)-methyltransferase (TPMT) activity tend to respond well to AZA therapy. In a previous study of Japanese SLE patients under low-dose AZA therapy, the group with the 94C>A mutation in inosine triphosphatase (ITPA) showed greater improvement in their disease activity index. However, it is not yet clear how genotypes relate to responsiveness to RA treatment. The genotypes ITPA 94C>A, TPMT*3C, NUDT15 595C>T, GST-M1, GST-T1 and MRP4/ABCC4 2269G>A of Japanese patients with RA were determined. The relationship between these genotypes and response to AZA therapy was evaluated using the Disease Activity Score 28 (DAS28) and various medical data. Of the 22 patients 15 had the ITPA 94C/C genotype, 7 had the ITPA 94C/A genotype, none had the TPMT*3C mutation, 4 had the NUDT15 595C>T mutation, 8 had the GST-M1 and T1 null genotypes and 9 had the MRP4/ABCC4 2269G>A mutation. Changes in DAS28 at 6 months after baseline were similar in both ITPA genotype groups. However, the maintenance dose of AZA was significantly lower in the C/A group than in the C/C group (0.85±0.30 mg/kg/day vs. 1.2±0.46 mg/kg/day, respectively; p = 0.043). The ITPA 94C/A group showed the same response to RA treatment as the C/C group, but at a lower dose. This demonstrates that RA patients with the ITPA 94C>A mutation are more responsive to AZA.

Methylmercury Exposure and Developmental Outcomes in Tohoku Study of Child Development at 18 Months of Age

Seafood is an important component in a healthy diet and may contain methylmercury or other contaminants. It is important to recognize the risks and benefits of consuming seafood. A longitudinal prospective birth cohort study has been conducted to clarify the effects of neurotoxicants on child development—the Tohoku Study of Child Development (TSCD) in Japan. TSCD comprises two cohorts; a polychlorinated biphenyls (PCB) cohort (urban area) and a methylmercury cohort (coastal area). Our previous results from the coastal area showed prenatal methylmercury exposure affected psychomotor development in 18-month-olds, and boys appear to be more vulnerable to the exposure than girls. In this report, we have added the urban area cohort and we reanalyzed the impact of prenatal exposure to methylmercury, which gave the same results as before. These findings suggest prenatal exposure to low levels methylmercury may have adverse effects on child development, especially in boys.

Patient Registration and Treatment Allocation in Multicenter Clinical Trials Using a FAX-OCR System

This article describes the design and results of implementation of an automated patient registration and freatment allocation system (RETAS) used in multicenter clinical trials. RETAS was developed using a FAX-OCR system by which handwritten Japanese and English characters, as well as numericals and forms with check boxes, are sent from participating institutions by Fax, processed using an optical character reader, and then transmitted to a host computer at a statistical center. Based on the facsimile data, RETAS can automatically review eligibility, collect patient identification data and provide a randomized treatment allocation. RETAS permits uninterrupted, unattended operation at a statistical center, 24 hours a day, 7 days a week. Therefore, it drastically decreases the workload of personnel at the statistical center needed to support central telephone registration coverage. Consequently, staff members are free to focus on patient registration, treatment allocation, and follow-up of patients. The treatment allocation procedure in this system is based on Pocock and Simon’s minimization method combined with Zelen’s method for institution balancing. By this system it was possible to balance treatment numbers for each level of various prognostic factors over an entire trial and, at the same time, balance the allocation of treatments within an institution. The system currently supports the protocol of a clinical trial for Adjuvant Chemo-Endocrine Therapy for Breast Cancer in West Japan.

Placental transfer and levels of mercury, selenium, vitamin E, and docosahexaenoic acid in maternal and umbilical cord blood

Methylmercury (MeHg) is a neurotoxicant known to affect the developing fetal brain as a sensitive target organ. As most mercury (Hg) in blood is MeHg, total mercury (THg) levels in blood are used to estimate the body burden of MeHg. The nutrients selenium (Se), vitamin E, and docosahexaenoic acid (DHA) are protective against MeHg toxicity. We compared maternal and cord blood concentrations of biochemical substances, THg and Se, vitamin E, DHA, and other elements, fatty acids, and amino acids in 54 Japanese mother-newborn pairs to elucidate the fetal risk of MeHg toxicity. Cord blood had higher hematocrit and amino acid values and lower concentrations of lipid components, including fatty acids compared with maternal blood. THg levels in cord blood (7.26ng/g) were 1.9 times higher than levels in maternal blood (3.79ng/g). Se concentrations in cord blood (176ng/g) were slightly higher than concentrations in maternal blood (156ng/g). Levels of vitamin E (0.31mg/dL) and DHA (58.8μg/mL) in cord blood were much lower than levels in maternal blood (1.38mg/dL and 147μg/mL, respectively). The ratios of Se/THg, vitamin E/THg, and DHA/THg in cord blood were lower than ratios in maternal blood. These results suggest that fetuses are at higher risk to MeHg toxicity.

Aqueous and Vitreous Penetration of Levofloxacin after Topical and/or Oral Administration

PURPOSE

To investigate the aqueous and vitreous penetration of levofloxacin, the drug was administered topically and/or orally to patients undergoing vitrectomy.

METHODS

Thirty-six patients undergoing initial vitrectomy with phacoemulsification and aspiration (PEA) were enrolled, and were divided randomly into three groups. Group 1 was treated with topical application of levofloxacin (three times on the day before surgery and seven times on the day of surgery), Group 2 received oral administration of levofloxacin (200 mg twice on the day before surgery and 200 mg at 3 hours before surgery), and Group 3 received both topical and oral levofloxacin according to the above schedules. The concentration of levofloxacin was measured in aqueous humor and vitreous fluid samples obtained during surgery.

RESULTS

In Groups 1, 2, and 3, the mean levofloxacin concentration in aqueous humor was 0.765+/-0.624 micro g/mL, 1.279+/-0.440 micro g/mL, and 1.823+/-0.490 micro g/mL, respectively, while the mean levofloxacin concentration in vitreous fluid was <0.02 micro g/mL, 1.455+/-0.445 micro g/mL, and 1.369+/-0.530 micro g/mL, respectively.

CONCLUSIONS

Oral administration of levofloxacin at a dose of 400 mg/day was sufficient for the prophylaxis of ocular infections, because the drug concentrations in both aqueous humor and vitreous fluid were higher than the MIC90 values for major ocular pathogens. Topical application of levofloxacin achieved adequate drug levels in aqueous humor, but not in vitreous fluid, while combined topical and oral administration had an additive effect on the drug concentration in aqueous humor.

Work-sharing and male employees' mental health during an economic recession

Background

One approach to reducing occupational stress during an economic recession is to share work amongst employees. This may include reducing employees' working hours to avoid redundancies.

Aims

To examine whether work-sharing influenced the psychosocial work environment and depressive symptoms encountered by Japanese employees, and to determine which psychosocial factors predict employees' mental health during an economic recession.

Methods

A survey was performed in a Japanese manufacturing company at the beginning (T1) and end (T2) of a 6-month period during the 2008 economic recession using the validated Job Content Questionnaire (JCQ) and Self-Rating Depression Scale (SDS).

Results

Three hundred and thirty-six male employees completed the questionnaire. Twenty-four per cent of participants showed depressive symptoms at T1. Despite reductions in employees' working hours and job strain (P < 0.001), SDS scores showed no change after 6 months. Logistic regression analyses showed that low social support between the two surveys was associated with depressive symptoms at T2 after adjusting for demographic, lifestyle, workplace factors, scheduled working hours and depressive symptoms at T1.

Conclusions

Reductions in job strain did not affect employees' depressive symptoms. Employees with low social support during the study had a significantly higher risk of having depressive symptoms. These findings indicate that social and emotional support within the workplace is important during the work-sharing period.