Toru Hosokawa

Neurobehavioral effects of prenatal exposure to methylmercury and PCBs, and seafood intake: Neonatal behavioral assessment scale results of Tohoku study of child development

As factors affecting neonatal neurodevelopment, methylmercury, polychlorinated biphenyls (PCBs), and maternal seafood intake reflecting n-3 polyunsaturated fatty acids (PUFAs) are believed to have adverse or beneficial effects, but there are a few reports addressing such factors simultaneously. We carried out a birth cohort study to clarify the effects of these three factors on the Neonatal Behavioral Assessment Scale (NBAS), administered 3 days after birth. In a total of 498 mother-neonate pairs, the total mercury level (median, 1.96microg/g) in maternal hair at parturition and the summation operatorPCB level (45.5ng/g-lipid) in cord blood were analyzed, and maternal seafood intake was estimated using a semi-quantitative food frequency questionnaire. A negative relationship between the hair mercury level and the motor cluster of NBAS was observed, even after adjusting for PCBs, maternal seafood intake, and possible confounders such as maternal age, birth weight, and parity. The summation operatorPCB level was negatively correlated with the motor cluster, but this association was attenuated after adjusting for mercury and the confounders. There was seen to be a positive association between maternal seafood intake and the motor cluster when considering the effects of mercury and PCBs. In conclusion, our data suggest that prenatal exposure to methylmercury adversely affects neonatal neurobehavioral function; in contrast, maternal seafood intake appears to be beneficial. The neurobehavioral effect of prenatal exposure to PCBs remains unclear in our study. Further research is necessary to elucidate interactive effects of methylmercury, PCBs, and n-3 PUFAs, originating from fish, on child neurodevelopment.

RELIABILITY AND VALIDITY OF A JAPANESE VERSION OF THE SHORT-FORM EYSENCK PERSONALITY QUESTIONNAIRE-REVISED

The reliability and the validity of a Japanese version of the short-form Eysenck Personality Questionnaire—Revised were examined for 329 college students and 253 adults. Coefficient alpha reliabilities for the four scales (Psychoticism, Extraversion/Introversion, Neuroticism, and Lie) were greater than 0.71 except for Psychoticism. Test-retest reliability of the four scales over 6 months ranged from 0.70 to 0.85, indicating a substantial stability. A confirmatory factor analysis supported the original theoretical structure of the four personality dimensions as proposed by Eysenck, Eysenck, and Barrett in 1985. Concurrent validity of the revised short-form was evaluated through the comparison of the four scores with the scores on the Maudsley Personality Inventory and the Sixteen Personality Factor Questionnaire. Over-all, the Japanese version of the revised short-form appears to be comparable to the original English version and would be useful for measuring personality in a wide range of settings.

Self-face recognition in children with autism spectrum disorders : A near-infrared spectroscopy study

It is assumed that children with autism spectrum disorders (ASD) have specificities for self-face recognition, which is known to be a basic cognitive ability for social development. In the present study, we investigated neurological substrates and potentially influential factors for self-face recognition of ASD patients using near-infrared spectroscopy (NIRS). The subjects were 11 healthy adult men, 13 normally developing boys, and 10 boys with ASD. Their hemodynamic activities in the frontal area and their scanning strategies (eye-movement) were examined during self-face recognition. Other factors such as ASD severities and self-consciousness were also evaluated by parents and patients, respectively. Oxygenated hemoglobin levels were higher in the regions corresponding to the right inferior frontal gyrus than in those corresponding to the left inferior frontal gyrus. In two groups of children these activities reflected ASD severities, such that the more serious ASD characteristics corresponded with lower activity levels. Moreover, higher levels of public self-consciousness intensified the activities, which were not influenced by the scanning strategies. These findings suggest that dysfunction in the right inferior frontal gyrus areas responsible for self-face recognition is one of the crucial neural substrates underlying ASD characteristics, which could potentially be used to evaluate psychological aspects such as public self-consciousness.

Psychometric Equivalence of the Hasegawa Dementia Scale—Revised with the Mini-Mental State Examination in Stroke Patients

Responses to the Hasegawa Dementia Scale—Revised and the Mini-Mental State Examination were examined for 49 stroke patients to investigate the psychometric equivalence between the two tests. Pearson product-moment correlation and Spearman rank-order correlation between the two tests were 0.87 and 0.78. Each tests scores significantly correlated with the Full Scale IQs on the Wechsler Adult Intelligence Scale—Revised: 0.61 for Hasegawas Dementia Scale and 0.69 for the Mini-Mental State Examination. These values indicate that the two tests are judged comparable measures for screening cognitive impairment in stroke patients.

Day-to-Day Variability in Home Blood Pressure Is Associated With Cognitive Decline The Ohasama Study

Although an association between high blood pressure and cognitive decline has been reported, no studies have investigated the association between home blood pressure and cognitive decline. Home blood pressure measurements can also provide day-to-day blood pressure variability calculated as the within-participant SD. The objectives of this prospective study were to clarify whether home blood pressure has a stronger predictive power for cognitive decline than conventional blood pressure and to compare the predictive power of the averaged home blood pressure with day-to-day home blood pressure variability for cognitive decline. Of 485 participants (mean age, 63 years) who did not have cognitive decline (defined as Mini-Mental State Examination score, <24) initially, 46 developed cognitive decline after a median follow-up of 7.8 years. Each 1-SD increase in the home systolic blood pressure value showed a significant association with cognitive decline (odds ratio, 1.48; P=0.03). However, conventional systolic blood pressure was not significantly associated with cognitive decline (odds ratio, 1.24; P=0.2). The day-to-day variability in systolic blood pressure was significantly associated with cognitive decline after including home systolic blood pressure in the same model (odds ratio, 1.51; P=0.02), whereas the odds ratio of home systolic blood pressure remained positive, but it was not significant. Home blood pressure measurements can be useful for predicting future cognitive decline because they can provide information not only on blood pressure values but also on day-to-day blood pressure variability.

Impacts of prenatal exposures to polychlorinated biphenyls, methylmercury, and lead on intellectual ability of 42-month-old children in Japan.

BACKGROUND The age-specific impacts of perinatal exposures to polychlorinated biphenyls (PCB), methylmercury (MeHg), and lead on child neurodevelopment remain controversial. Since we have already reported the prenatal effects of these chemicals on neurodevelopment in 3-day-old and 30-month-old children of a birth cohort, the following effects were analyzed in the 42-month-old children in the same cohort. METHODS The Kaufman Assessment Battery for Children (K-ABC), comprised of four scales, was used to assess their intelligence and achievement. The relationships between the chemicals and K-ABC scores were analyzed using multivariate analyses. RESULTS The median values of chemicals in cord blood of 387 children were 46.5 (5th and 95th percentiles, 16.7-115.7)ng/g-lipid for total PCB, 10.1 (4.3-22.2)ng/g for total mercury (THg), and 1.0 (0.5-1.8) μg/dL for lead. Of the highly chlorinated PCB homologs, 9 CBs was negatively correlated with the sequential and mental processing score of the K-ABC (p<0.05). There were no significant correlations between any K-ABC score and either THg or lead. The negative effect of 9 CBs remained even after adjusting for THg, lead, and other confounders. The K-ABC scores were significantly lower in the boys than in the girls, and the standardized β of 9 CBs for the sequential and mental processing scores in multiple regression analysis was statistically significant in boys. CONCLUSIONS These findings suggest that intellectual ability in the developmental stage may be impaired by prenatal exposures to highly chlorinated PCB homologs, especially in Japanese boys.

Prenatal exposures to environmental chemicals and birth order as risk factors for child behavior problems

OBJECTIVES To assess whether polychlorinated biphenyls (PCBs), methylmercury, lead, or parental child-rearing attitudes was most crucial for maladaptive behavior problems, we examined Japanese 30-month-old children followed up from pregnancy. METHODS The Child Behavior Checklist (CBCL) was used to assess the behavior problems in 306 children. The associations of cord-blood total PCBs (ΣPCB), total mercury (THg), and lead with each CBCL subscale were examined by multivariate analyses. RESULTS The median values in cord blood of the 306 children were 48.3 (5 and 95 percentiles, 18.6-116.3) ng/g-lipid for ΣPCB, 10.2 (4.1-24.5)ng/g for THg, and 1.0 (0.5-1.7)μg/dl for lead. The internalizing score of the CBCL was significantly correlated with ΣPCB (r=0.113) in the children, though no significant correlation was seen between any CBCL score and either THg or lead. The significant correlation disappeared when conducting multiple regression analysis with possible confounders; at that time, the birth order, home environment, and maternal intelligence quotient were significantly related to the internalizing score. Three CBCL scores and ΣPCB levels were significantly higher in the first-born children than in the second-born or following children, and the partial correlation coefficient with the adjustment for all confounders except birth order was significant between the internalizing score and ΣPCB in the latter children (r=0.175). CONCLUSIONS Internalizing behavior appears to be affected by prenatal exposure to PCBs at low levels. Under lower-level exposures, however, behavior problems may be more strongly associated with parental child-rearing attitudes involved in birth order, than with such hazardous chemicals.

Personality and cancer survival: the Miyagi cohort study.

We tested the hypothesis that personality plays a role in cancer outcome in a population-based prospective cohort study in Japan. In July 1990, 41 442 residents of Japan completed a short form of the Eysenck Personality Questionnaire-Revised and a questionnaire on various health habits, and between January 1993 and December 1997, 890 incident cases of cancer were identified among them. These 890 cases were followed up until March 2001, and a total of 356 deaths from all causes was identified among them. Cox proportional-hazards regression was used to estimate the hazard ratio (HR) of death according to four score levels on each of four personality subscales (extraversion, neuroticism, psychoticism, and lie), with adjustment for potential confounding factors. Multivariable HRs of deaths from all causes for individuals in the highest score level on each personality subscale compared with those at the lowest level were 1.0 for extraversion (95% CI=0.8–1.4; Trend P=0.73), 1.1 for neuroticism (0.8–1.6; Trend P=0.24), 1.2 for psychoticism (0.9–1.6; Trend P=0.29), and 1.0 for lie (0.7–1.5; Trend P=0.90). The data obtained in this population-based prospective cohort study in Japan do not support the hypothesis that personality is associated with cancer survival.

ACCURACY OF SELF-REPORT FOR STOMACH CANCER SCREENING

Limited evidence is available regarding the accuracy of recall for cancer screenings. We compared the self-report of stomach cancer screening with medical records in 337 residents of a rural town in northeastern Japan, who were eligible for annual screening offered by the town. Frequencies of attendance within the last 5 years were asked in a self-administered questionnaire, and determined from the records of the organization conducting the screening. When the frequencies were dichotomized as ever/never screened within 5 years, the self-report agreed substantially with medical records, but tended to overestimate the actual attendance (kappa = 0.68, sensitivity = 100%, specificity = 75.6%). Past history of gastroduodenal diseases and family history of stomach cancer were associated with the overreport. Although the population studied was highly selective (rural Japanese volunteers), review of the previous studies on mammography and Pap smear also showed that self-reports tended to be exaggerated. Self-report of cancer screening should be regarded as an overestimated indicator of its true prevalence.

I Cannot Remember, But I Know my Past Events: Remembering and Knowing in a Patient With Amnesic Syndrome

Case Y.K. has severe anterograde amnesia and a selective loss of specific personal episodes in his remote memories (Hirano & Noguchi, 1998). In this paper, we attempted to analyze remembering (R) and knowing (K) responses, that is, the relationship between autobiographical remembering and remembering accompanied by subjective experience. Although the rate of R responses was significantly higher than that of K responses in control subjects, Y.K.s R responses were rare in all subtypes of remote memories. Based on these results, we conclude that Y.K.s memories on autobiographical incident task were not based on episodic memory but rather on semantic memory. Thus, the autobiographical incidents he could recall were not episodic memory, and his semantic memory made him recall information as fact rather than episode.