Yoshikatsu Mochizuki

Fetal growth and the timing of exposure to maternal smoking

Background : Maternal smoking during the third trimester reduces the birthweight of the full‐term neonate. We assessed the relationship between the timing of exposure to maternal smoking, gestational period, weight and body length for both full‐term and preterm neonates.

Post-traumatic stress disorder in pre-school aged children after a gas explosion.

Abstract. To evaluate the sensitivity of diagnostic criteria for post-traumatic stress disorder (PTSD) in pre-school aged children involved in a gas explosion, post-traumatic symptoms of the children were investigated four times after the accident, immediately, 10 days, 6 months, and 1 year later. Using symptoms at 6 months after the accident, sensitivity of diagnostic criteria was assessed by comparing the fourth edition of the American Psychiatric Associations Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), and the alternative criteria for infants and young children [10]. In addition, the published Child Post-Traumatic Stress Disorder Reaction Index (CPTSD-RI) and its modified version proposed by us were also evaluated their sensitivity to rate the symptoms. Girls had a tendency to show more post-traumatic symptoms than boys. Although no children met DMS-IV criteria for PTSD, 8 children out of 32 were diagnosed as having PTSD with alternative criteria. With our modified CPTSD-RI, all eight children were decidedly more statistically distinguishable from those without PTSD than with original index. Conclusion: our data indicate that the sensitivity of the American Psychiatric Associations Diagnostic and Statistical Manual of Mental Disorders (4th edition) and the Child Post-Traumatic Stress Disorder Reaction Index in rating symptoms of pre-school aged children is not sufficient. The alternative criteria of the former and modified version of the latter would be the better choice in this age group.

Separation and characterization of metallothionein in two species of seals by high performance liquid chromatography-atomic absorption spectrophotometry

Metallothionein (MT) was separated from the livers of two species of seals, ribbon seal (Histriophoca fasciata) and harbour seal (Phoca vitulina), by high performance liquid chromatography--atomic absorption spectrophotometry (HPLC-AAS). Both gel permeation and anion-exchange HPLC demonstrated that MT was present as a mixture of at least two isoforms in the livers of both species of seals.

In vitro effects of mercury-selenium compounds on enzymes

In vitro effects of mercury-selenium compounds, as compared with mercurials, against glucose-6-phosphate dehydrogenase (G6PD), catalase and trypsin were studied. Inhibitory potencies of two mercury-selenium (Hg-Se) compounds, bis(methylmercuric) selenide (BMS), and a reaction product of HgCl2, Na2SeO3 and glutathione (GSH), were markedly weaker than those of their original mercurials, methylmercury and mercuric mercury, respectively.

Comparison of cytotoxicity of mercury-selenium and mercury compounds on cultured cells

In vitro effects of mercury-selenium (Hg-Se) compounds, as compared with their original mercury compounds, against growth and viability of HeLa cells were studied. A water-soluble, ethanol-insoluble black complex (GX) formed from HgCl2, Na2SeO3 and GSH was less toxic than HgCl2, but the cytotoxicity of bis(methylmercuric) selenide (BMS) seemed to be similar to that of methylmercury. This may be due to the instability of BMS; i.e., there is a possibility that BMS decomposed to methylmercury and selenium under our culture conditions.

The male/female ratio of spontaneous fetal deaths and low birthweight in Japan.

© 2008 Japan Pediatric Society The male/female ratio of births has been observed to be decreasing during the past few decades both in Europe and the USA, and in Japan. 1,2 This decrease is considered to be the result of the increased sex ratio of fetal deaths. 3 Exposure to toxic agents, such as dioxin and methylmercury, stress and parental periconceptional smoking, have been suggested as causes of the declining sex ratio of births. 4 These agents might cause deterioration of the intrauterine environment and thus make the relatively vulnerable male fetus more likely to die. At the same time, an increase in term low-birthweight neonates due to intrauterine growth retardation has been reported in Japan. 5 Maternal smoking and excessive dieting were proposed as the major factors involved in this trend. These factors might also aggravate the intrauterine environment for fetal growth. In order to determine what was happening in the uterus, we studied vital statistics with the specifi c purpose of ascertaining the timing of male fetal death and the relationship between growth retardation and sex.

Catalytic coefficient as a parameter for substrate specificity of enzymes

1. 1. Catalytic coefficient (Ccat) was tested in 33 species with respect to glucose-6-phosphate dehydrogenase (G6PD) in order to evaluate its validity as a parameter for substrate specificity. 2. 2. By comparing the Ccat values for G6P analogs, the difference between G6PD and hexose-6-phosphate dehydrogenase (H6PD) was emphasized. 3. 3. Comparison of the Ccat values for NAD showed that H6PD should be classified into the G6PD with dual nucleotide specificity according to Levys classification.