Site-selective XAFS spectroscopy tuned to surface active sites of Cu/ZnO and Cr/SiO2 catalysts.

XAFS (X-ray absorption fine structure) spectra were measured by using the fluorescence spectrometer for the emitted X-ray from sample. The chemical shifts between Cu0 and Cu1 and between CrIII and CrVI were evaluated. Tuning the fluorescence spectrometer to each energy, the Cu0 and CuI site-selective XANES for Cu/ZnO catalyst were measured. The first one was similar to the XANES of Cu metal and the second one was the 5 : 5 average of XANES for CuI sites + Cu metal. The population ratio of copper site of the Cu/ZnO catalyst was found to be Cu metal: Cu2O : CuI atomically dispersed on surface = 70(+/-23) : 22(+/-14) : 8(+/-5). Site-selective XANES for CrIII site of Cr/SiO2 catalyst was also studied.

Identification and antioxidant activity of several pigments from the residual green tea (Camellia sinensis) after hot water extraction.

Antioxidant activity of green tea extract or tea-derived polyphenols has been extensively studied. However, antioxidant activity in the non-polyphenolic fraction of green tea has been poorly analyzed. In the present study, we analyzed the antioxidant activity of the non-polyphenolic fraction of the residual green tea (Camellia sinensis) after hot water extraction using the aluminum chloride method. The non-polyphenolic fraction of residual green tea caused a significant suppression against hydroperoxide generation from oxidized linoleic acid in a dose-dependent manner. When the concentrate of the non-polyphenolic fraction was applied to a silica gel TLC plate and developed, six color spots were observed, which were considered to be chlorophylls a and b, pheophytins a and b, carotenoids, such as beta-carotene and lutein according to their specific colors, Rf values of silica gel TLC and spectrophotometric properties. Among these pigments, pheophytins a and b showed relatively abundant amounts, and the second major group of the pigment was chlorophylls a and b, and carotenoids such as beta-carotene and lutein indicated lower concentrations. Although all these pigments exhibited significant antioxidant activities, the ranks of suppressive activity against hydroperoxide generation were chlorophyll a > lutein > pheophytin a > chlorophyll b > beta-carotene > pheophytin b. These results suggest that the non-polyphenolic fraction of residual green tea has a potent suppressive activity against hydroperoxide generation from oxidized linoleic acid, which is derived from the antioxidant activities of chlorophylls a and b, pheophytins a and b, beta-carotene and lutein. This finding also implies that the combined intake of polyphenols in water-soluble fraction and antioxidative pigments in the non-polyphenolic fraction of green tea will be more efficient to prevent life style-related chronic diseases.

Sleeping environments as risk factors of sudden infant death syndrome in Japan.

For the purpose of assessing the risk factors of the sleeping environment in SIDS, we performed a population-based, case-control study. Index cases comprised 56 SIDS cases which were diagnosed on the basis of autopsies during a period of 11 years at the Department of Legal Medicine, Faculty of Medicine, University of the Ryukyus. Control cases comprised infants who were examined at regional health centers for Infant Health Screening. The incidence of SIDS obtained was 0.25 per 1000 live births, which was comparable to that obtained in other districts having the established medical examiner's system. The proportion of prone sleeping was 81.0% and 38.3% in the SIDS and control groups, respectively, and an odds ratio was calculated as 10.4 (99% confidence interval, 3.9 to 37.6). This indicates that prone sleeping is a risk factor of SIDS, in Japan, as reported in various countries. Various kinds of bedclothes were used in this country, and our survey of bedclothes in the control revealed their improper use for infants to sleep, particularly with the prone position. In addition, the co-sleeping habit, which was not uncommon in Japan, seems to contribute to certain deaths of infants whose causes of death were controversial. In the investigation of SIDS, therefore, the sleeping environments, such as bedclothes and the co-sleeping habit, as well as the sleeping position should be taken into consideration as risk factors.

Regulation of melanophore responsiveness in the background-adapted medaka, Oryzias latipes: change in the intracellular signaling system.

The responsiveness of melanophores of the medaka fish (wild type, Oryzias latipes) to a neurotransmitter and hormones is changed differentially after long-term adaptation to a black or white background. In the present study, we further examined whether this phenomenon involved some change in the intracellular signaling system. Using a permeabilized melanophore model, in which pigment granules could be dispersed by exogenously applied cAMP, the requirement of cAMP for pigment-dispersing reaction was revealed to be higher in melanophores of fish adapted to a black background (B cells) than in those of white background-adapted fish (W cells). Specific inhibitors of cAMP-dependent protein kinase (PKA) and cyclic nucleotide phosphodiesterase did not reduce the difference in the pigment dispersion level between B and W cells. A similar result was obtained with the free catalytic subunit of PKA. In contrast, the inhibition of protein phosphatase activity by okadaic acid diminished the difference in the responsiveness between B and W cells. These results suggest that the activity of protein phosphatase in B cell is higher than that in W cells, and that the change in the melanophore responsiveness by long-term chromatic adaptation to a background involves the change in the enzyme activity in the intracellular signaling system.

[Statistical observations on the cases of unnatural deaths examined at our department during the past 10 years].

Medicolegal evaluation of 1495 cases of unnatural death of last 10 years was carried out in our department and the data so obtained were statistically analysed. The cases consisted of 260 inspections, 865 judicial autopsies and 370 administrative autopsies. The most frequent category was death from diseases followed by suicide, homicide, traffic accidents, other accidents and self originated accidents. In homicide cases, sharp objects were mainly used. Six cases of accident of scuba diving were included within the group of 28 cases of drowning of self originated variety. Although Okinawa is subtropical 12 cases of death by accidental hypothermia were found. Gangland fight using rifles cost 7 lives, 2 policemen, a high school student and 4 members of locally originated gangsters during last 18 months. Cardiac insufficiency was the most common of sudden unexpected death cases that complied with the data of Tokyo and Osaka. Death from alimentary disorder in Okinawa was 1.5 times more frequent than that in Tokyo and Osaka and liver disorder accounted for about 41%. The 68 cases of death from suckling contained 10 SIDS cases. Complication of medical treatment was encountered in 9 cases during the past 10 years.

The influence of tetrodotoxin on the toxic effects of aconitine in vivo.

Both aconite toxins (aconitine, mesaconitine, and hypaconitine) and a pufferfish toxin (tetrodotoxin, TTX) were detected in the blood of a legal autopsy case. In order to elucidate the in vivo influence of TTX on the toxic effects of aconitine, a mixture of aconitine and TTX was administered to male ICR mice orally or intraperitoneally. The animal experiments revealed that the time of death due to aconitine was significantly delayed in proportion to the dose of TTX compared with the case for aconitine alone, and that the mortality of aconitine was lowered by TTX when the dose ratio of the two toxins was in a particular range. Accordingly, it is thought that the toxic effects of aconitine are attenuated by TTX in vivo.

Sex determination from human somatic cells.

The method and its reliability for sex determination by examining X-chromatin in the nucleus of hair root cell and buccal mucosa cell are presented: 1) X-chromatin in the nucleus of hair cortex cell was stained by Feulgen reaction after bleaching melanin granules and the frequency of X-chromatin was calculated under a ordinary microscope. An another method, fluorescent Feulgen reaction with acriflavine using a fluorescence microscope, was attempted. The results obtained from both methods indicated significantly higher values in the female samples than those in the male ones. 2) The other hand, the frequency of Y-chromatin was determined after quinacrine staining using a fluorescence microscope, and was also distinguishable between the male and female samples. 3) Using a single specimen, sex determination from the frequency of X- or Y-chromatin was practicable through combined treatment of quinacrine staining and fluorescent Feulgen reaction. 4) These methods were available during 16 to 64 weeks at least regarding samples kept dry. It is concluded that sex determination from frequency of sex chromatin after treatment described above is reliable.

Distribution of Gm allotypes among the three populations of the Miyako Islands in Okinawa.

Serum samples from 738 unrelated individuals of three populations in the Miyako Islands were tested for twelve Gm allotypes to investigate the variability of phenotypes and haplotypes. Nine phenotypes observed in these populations as well as mainland Japanese could be explained by the presence of the four Gm haplotypes, ag, axg, ab3st, and afb1b3. A good agreement was obtained in the samples of each populations between the observed and expected frequencies on the basis of the Hardy-Weinberg equilibrium of phenotypes. These populations showed remarkable heterogeneities with one another on the basis of Gm haplotype frequency analysis. Moreover they exhibited no homogeneities with the Ryukyuans nor with the mainland Japanese. Homogeneity was found between the Ainu and the people in Ueno village but not in the other two locations. However, Gm xg haplotype, only detected in the Ainu, was not found in Ueno. These may imply a racial relationship between the Ainu and the inhabitants in Miyako in the remote past. However, there is no certainty that both of Ainu and the people in Ueno derived from the same origin, or that genetic drift due to endogamy in this village took place. The Gm phenotype and haplotype frequencies observed in Miyako show that they belong to the northern mongoloid group characterized by a high frequency of Gm ag and an extremely low frequency of Gm afb1b3. It is therefore reasonable to assume that they came from northern Asia as well as mainland Japanese.

Sex determination from buccal mucosa and hair root by the combined treatment of quinacrine staining and the fluorescent Feulgen reaction using a single specimen.

In order to determine sex using a single specimen, buccal mucosa and hair roots obtained from male and female individuals were used. The specimens were first stained with quinacrine for the detection of the Y-chromatin, and subsequently were stained by the fluorescent Feulgen reaction using acriflavine for the detection of the X-chromatin. In the male specimens, the frequency of fluorescent spots of quinacrine-positive bodies was high, whereas that of acriflavine-positive spots was low. On the other hand, in the female specimens, the frequency of quinacrine-positive spots was very low, while that of the acriflavine-positive spots was high. These specimens were air-dried and were allowed to stand at room temperature for periodical observations. The result was that sex difference was distinguishable for 4 months by the combined treatment method.

A comparative study on the effects of paraquat and diquat on cultured human cells.

The effects of paraquat on human embryonic somatic cells were compared with those of diquat, which is a bipyridylium compound similar to paraquat. Cell lesions, mainly fatty degeneration, were observed after staining with Sudan Black B. Both herbicides caused fatty degeneration in the cells even at a concentration of 1 ppm; paraquat also caused more vacuolar degeneration at 200 to 400 ppm, than did diquat. Paraquat caused slightly higher lactate dehydrogenase activity than did diquat. The cell mortality was examined by staining with nigrosine and calculating the number of dead and damaged cells. The cell mortality for diquat was higher than that for paraquat at all concentrations but not significantly (p less than 0.05).

Sex determination from plucked human hairs without epithelial root sheath. III. Fluorescent feulgen reaction using acriflavine.

In order to determine sex from plucked human hair roots devoid of epithelial root sheath, the frequency of the X-chromatin was examined in hair cortex nuclei of plucked hairs stained by the fluorescent Feulgen reaction using acriflavine. There was a distinct difference between male and female hairs, the frequency ranging from 27% to 70% (average 45.8%) in female samples and from 0% to 8% (average 2.9%) in male samples. The difference in the frequency between male and female was detected in samples kept in a dried condition for 32 weeks.

Sex determination from plucked human hairs without epithelial root sheath. II. Depigmentation of melanin in the hair cortex before Feulgen reaction.

In hair roots devoid of the epithelial root sheath, an attempt was made to decolorize the melanin granules without affecting the Feulgen reaction for the sex chromatin. The hair samples were treated with 0.25% potassium permanganate for 1 hour, 0.3% hydrogen peroxide for 1 minute and 5% potassium permanganate for 1 hour, 0.3% hydrogen peroxide for 1 minute and 5% oxalic acid for 5 minutes, and then stained with Feulgen. The frequency of sex chromatins ranged from 22% to 47% (average 32%) in female samples and from 0% to 8% (average 5%) in male samples. Thus, the frequency distributions of the male and female samples were completely independent of each other. The sex chromatins in dried female hairs were detectable at a frequency of 16 - 26% several weeks after plucking. The depigmentation procedure almost completely bleached the melanin granules in the hair cortex, and produced no harmful effect on the Feulgen reaction that followed.

The effects of paraquat on cultured human embryonic cells.

The effects of paraquat on human embryonic somatic cells were studied. Monolayer cultured cells, from several different organs, were exposed to various concentrations of paraquat. Then, the cells were stained with nigrosine and Sudan IV to demonstrate dead or damaged cells and fatty granules, respectively. The lowest paraquat concentration that caused morphological changes varied from 1 to 10 ppm, and the lowest concentration that caused fatty degeneration varied from 1 to 5 ppm. In both types of staining, the lowest degenerative concentration was lower as the culture generation was younger, and the degree of degeneration did not differ with the cell origin. The protein content per cell in paraquat-treated cells was not significantly decreased in comparison with control cells.