Catalase-deficient mouse strains was initially established by Feinstein et al. through a large scale screening of the progeny of irradiated C3H mice in 1966. Later, Feinstein provided the mice of catalase mutant strain C3H/AnlCs^aCs^a (wild-type), C3H/AnlCs^bCs^b and C3H/AnlCs^cCs ^c to Okayama University Medical School in Japan. It is known that a point mutation at amino acid 11 (from glutamine to histidine) of acatalasemic mouse catalase and a point mutation at amino acid 439 (from asparagine to serine) of hypocatalasemic mouse catalase are responsible for the catalase deficiency of acatalasemic and hypocatalasemic mice, respectively. Recently, a liver cell line from an acatalasemic mouse and Escherichia coli (E. coli) strains with murine normal, hypocatalasemic, or acatalasemic catalase have been established. The construction of these new systems would be useful for studying the effects of oxidative stress at the cellular level. In this review, we give a brief overview of recent findings of studies in utilizing the catalase-deficient mice and evaluate the possibility of these mouse strains as a candidate animal model for oxidative stress research.

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Objectives: The purpose of this study was to quantitatively and qualitatively examine a gender difference of subjective symptoms of fatigue (SSF) in healthy students.
Methods: The subjective fatigue scale for young adults (SFS-Y) consisted of the following 6 subscales: concentration thinking difficulty, languor, reduced activation, reduced motivation, drowsiness and feeling of physical disintegration. The SFS-Y was administered to 5,435 students aged 15 to 20 yr.
Student's t test was used to examine quantitative gender differences for items and factor scores. The qualitative gender difference was examined by comparing factor structures obtained from confirmatory factor analysis.
A similarity in the factor structure was evaluated from: 1) interpreted factor names, 2) factor loadings, 3) degree of fit, and 4) congruence coefficient.
Results: A complaint of SSF shows gender differences, but the difference is not remarkable. The factor structure of SSF in males and females is suggested to be the same, because six factors with the same name were interpreted in both groups and the similarity of factor structure was very high.
Conclusion: There are some qualitative gender differences in SFS, but no qualitative gender differences in factor structure.

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Objectives: The epigallocatechin-3-gallate (EGCg) that is present in human diet originates mainly from tea leaves. Catechins have a number of possible application as medicines, however, there is no consistent evidence showing their influence on the gastrointestinal tract. Thus, the aim of the present study was to investigate the effect of EGCg on the motility of the murine isolated intestine.
Methods: Segments of jejunum submerged in Krebs buffer were exposed to EGCg and the response was recorded under isometric conditions.
Results: EGCg induced a dose-dependent inhibition of spontaneous activity in the jejunum. EGCg induced a decrease in the amplitude and frequency of jejunal contractions. Moreover, the rythmicity of spontaneous activity was altered in the presence of EGCg. A significant effect of EGCg was observed in the presence of 10⁻⁴ M. The effect of EGCg was in part inhibited by pretreatment with methylene blue (guanylate cyclase inhibitor), while tetrodotoxin, (sodium channel blocker), L-nitro arginine methyl ester (nitric oxide synthase inhibitor), and N-ethylmaleimide (adenylate cyclase inhibitor) showed no effect.
Conclusions: The results of the present study suggest that EGCg inhibits the motility of the jejunum by direct action on smooth muscle cells where a guanylate cyclase-dependent mechanism may be partly involved.

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Object: The purposes of this study were to investigate the actual status in subjective symptoms of fatigue (SSF) and lifestyles of young male students living in two different life spheres of the Tokyo metropolitan area and a rural area, and to find regional differences in these characteristics and relations between SSF and lifestyles in school life.
Methods: A questionnaire regarding SSF and lifestyle was administered to 412 healthy male students (16-18 yr) attending the two National Colleges of Technology located in the Tokyo metropolitan area (MA) and a local city (LC). Statistical techniques such as a chi-square test and Hayashi’s Quantification Theory I analysis were used to examine relations between SSF and lifestyles.
Results and conclusion: A significant difference was found only in “feeling of physical disintegration,” and the MA group was higher than the LC group. The MA students showed shorter sleeping hours and earlier awaken time compared with LC students. In the relations between SSF and lifestyles, sleeping habit was an important factor significantly relating to SSF in both groups. Paying attention to good sleeping habits is an important countermeasure for preventing SSF in the male students.

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Objectives: To clarify whether di (2-ethylhexyl) phthalate (DEHP) has immunotoxic effects on both the expression of surface molecules (CD3, CD4, CD8 and CD28) on T cells of the thymus and spleen in male C57BL/6 mice.
Methods: Animals were orally administered a 0.1% or 0.2% DEHP-containing diet for 10 or 20 days. Dietary corn oil was used as the vehicle for DEHP in preparing the diet.
Results: Significant hepatic hypertrophy was clearly observed in the DEHP-exposed groups, while no atrophy was seen in the thymus or spleen in any treatment groups. In the thymus and spleen, no variation in the proportions of both T cells expressing CD3, CD4 and CD8 was shown with cytometry analysis. The surface expression of CD3, CD4, CD8 and CD28 on both T cells was also invariable in all analyzed stages of thymic differentiation and in the spleen. No effect of DEHP on mitogenesis was shown in the splenic T cells with an in vitro [³H]-thymidine-incorporation technique.
Conclusions: DEHP is probably not an immunosuppressor, particularly for T cells.

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Objectives: Welders are exposed to intense heat, toxic metals and their oxides and toxic gases during welding, and some of these substances reported to have adverse effects on reproductive organs. Thus, the present study was planned to investigate the sperm quality as well as reproductive hormones among welders exposed to a complex mixture of pollutants.
Methods: Seventeen welders aged 43.8±12.0 (mean±SD) years with welding exposure of 1 to 10 years or more participated in this study. They were performing arc and gas welding in a workshop. Blood (5-6 ml) and semen samples by masturbation were collected from them. Serum was separated and analyzed for reproductive hormones by RIA techniques. Semen was processed for microscopic examination.
Results: The results of this study indicated that sperm concentration was in the normal range (³20 million/ml) in all seventeen welders, however, motility, morphology as well as Hypo Osmotic Swelling test (HOS) demonstrated impairment in few welders, indicating deterioration in sperm quality compared to the reported normal reference value. Compared with the normal value of hormones provided in diagnostic kits brochure, follicle stimulating hormone (FSH), leutinizing hormone (LH) and testosterone levels were in the normal range, except in two subjects who showed higher FSH and LH levels and one who showed a lower value of testosterone.
Conclusions: This study suggests that welding might have had some adverse effects on sperm motility, morphology and physiologic function even though sperm concentration was in the normal range. Hormonal changes did not show any definite pattern, indicating a need for further study.

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