Secondary abnormality of carnitine biosynthesis results from carnitine reabsorptional system defect in juvenile visceral steatosis mice

We characterized the L-carnitine transport system which is defective in the kidney of juvenile visceral steatosis (JVS) mice by using kidney slices and carnitine-related compounds, and evaluated the influence of the transport defect on the biosynthetic pathway of carnitine. The JVS mouse transport system defect, calculated as the difference in the transport activity between control and JVS mice, was simulated in control by gamma-butyrobetaine (gamma-BB) and acetyl L-carnitine. gamma-BB hydroxylase activity in the liver of JVS mice was double that of control mice, but the hepatic level of gamma-BB in JVS mice was lower than in control mice, suggesting that the conversion of gamma-BB to carnitine is not activated in the liver of JVS mice. JVS mice showed higher fractional excretions not only of L-carnitine but also of gamma-BB and acetyl L-carnitine than control mice, indicating disturbed reabsorption of gamma-BB and acetyl L-carnitine. The disturbed reabsorption of gamma-BB in JVS mice is consistent with the fact that the amount of urinary gamma-BB in JVS mice was four times that of control. The sum of the concentrations of L-carnitine, acetyl L-carnitine and gamma-BB in the urine of JVS mice was not significantly different from that of the control, suggesting no remarkable increase of biosynthesis of gamma-BB and carnitine in JVS mice. All these findings suggest that the carnitine transport system plays a role in the transport of gamma-BB and that carnitine deficiency is aggravated by the disturbed reabsorption of gamma-BB in the kidney.     

Effect of measuring bone mineral density on calcium intake

The diet in Japan has improved, but calcium intake has not increased for the past ten years, and it remains insufficient. To prevent osteoporosis, instruction in nutrition is directed at increasing calcium intake. We studied the effect of measuring bone mineral density on calcium intake in people receiving nutrition education. Intake of other nutrients was also measured. The subjects were 87 healthy women living in an agricultural region (Yamanashi Prefecture). They were members of a group formed to improve the diet of people in their area. For three days in October 1992 and in August 1994 food-weight records were obtained. A total of 76 of the 87 women chose to have their bone mineral density measured. The measurements before the first nutrition assessment in 1992. The intake of almost all nutrients tended to be greater in 1994 than in 1992. Calcium intake exceeded the minimum daily requirement (600mg). Calcium intake increased between 1992 and 1994 only in the subjects whose bone mineral density had been measured. Calcium intake decreased in the other subjects. Therefore, nutrition education programs aimed at preventing osteoporosis may be more effective if bone mineral density is measured. In addition, an appropriate balance of other nutrients can be maintained as the intake of calcium is increased.     

Structure of a novel phytoecdysteroid,vitexirone, and efficient isolation of phytoecdysteroids fromVitex fisherii

A novel phytoecdysteroid, vitexirone, has been isolated from a MeOH extract of the root bark of the East African medicinal plantVitex fisherii by recycling high-performance liquid chromatography on a semipreparative scale. In addition, three known phytoecdysteroids, 20-hydroxyecdysone, ajugasterone C, and turkesterone, also were isolated. The structure of vitexirone has been established spectroscopically. The position and stereochemistry of the 11--hydroxy group of ajugasterone C and vitexirone were confirmed by the¹H-¹H homonuclear COSY NMR data. These phytoecdysteroids disrupt the molting process of the pink bollwormPectinophora gossypiella.     

Characterization and Sintering Behavior of Alkoxide-Derived Aluminosilicate Powders

Submicrometer SiO₂-Al₂O₃ powders with compositions of 46.5 to 76.6 wt% Al₂O₃ were prepared by hydrolysis of mixed alkoxides. Phase change, mullite composition, and particle size of powders with heating were analyzed by DTA, XRD, IR, BET, and TEM. As-produced amorphous powders partially transformed to mullite and Al-Si spinel at around 980°C. The compositions of mullite produced at 1400° and 1550°C were richer in Al₂O₃ than the compositions of stable mullite solid solutions predicted from the phase diagram of the SiO₂-Al₂O₃ system. Particle size decreased with increasing Al₂O₃ content. The sintered densities depended upon the amount of SiO₂-rich glassy phase formed during sintering and the green density expressed as a function of particle size.     

In situ TEM study on changes in structure and electrical conductance of carbon nanotube-gold contact induced by local joule heating

Electrical conductance of multi-walled carbon nanotubes (MWCNTs) with closed and open tips contacting with a gold (Au) electrode was studied by in situ transmission electron microscopy. When a current density through the contact region reached a threshold value of 2.6 × 10⁸ A/cm², the MWCNT tip was embedded into the Au surface by local melting of Au, and the total resistance was reduced with the increase of the contact area. Conductance per unit area at the contact between the MWCNT and Au electrode for the open-ended MWCNT is four times larger than that for the close-ended one, which is due to the direct connection of inner walls of the open-ended MWCNT with the Au surface.     

Molecular Hydrogen Enhances Proliferation of Cancer Cells That Exhibit Potent Mitochondrial Unfolded Protein Response

Molecular hydrogen ameliorates pathological states in a variety of human diseases, animal models, and cell models, but the effects of hydrogen on cancer have been rarely reported. In addition, the molecular mechanisms underlying the effects of hydrogen remain mostly unelucidated. We found that hydrogen enhances proliferation of four out of seven human cancer cell lines (the responders). The proliferation-promoting effects were not correlated with basal levels of cellular reactive oxygen species. Expression profiling of the seven cells showed that the responders have higher gene expression of mitochondrial electron transport chain (ETC) molecules than the non-responders. In addition, the responders have higher mitochondrial mass, higher mitochondrial superoxide, higher mitochondrial membrane potential, and higher mitochondrial spare respiratory capacity than the non-responders. In the responders, hydrogen provoked mitochondrial unfolded protein response (mtUPR). Suppression of cell proliferation by rotenone, an inhibitor of mitochondrial ETC complex I, was rescued by hydrogen in the responders. Hydrogen triggers mtUPR and induces cell proliferation in cancer cells that have high basal and spare mitochondrial ETC activities.     

Analysis of specific IgE antibodies to staphylococcal enterotoxins,total serum IgE and hemogramme in carriers of Staphylococcus aureus

In order to evaluate the relationship between nasal carriers of S. aureus and their history of allergic diseases, the total serum IgE titer, the hemogramme pattern, and the titers of specific IgE antibody to Staphylococcal enterotoxins A and B (SEA and SEB) and of specific IgG antibody to SEB were investigated in 98 trade school students. Fifteen (15.3%) of the 98 students were sensitized to SEA and/or SEB (40.0% to SEA and 93.3% to SEB). In this group, 11 subjects were S. aureus carriers (73.0%) and 12 had a history of allergic diseases (80.0%). Low levels of specific IgG antibody to SEB were identified from both S. aureus carriers and non-carriers. The S. aureus carriers had significantly higher levels of total IgE titer than the non-carriers and the individuals with a history of allergic diseases had significantly higher total IgE titer levels than those having no history of allergic diseases (p < 0.01). In the hemogramme patterns of S. aureus carriers, a significant positive correlation was observed between the total IgE antibodies and the eosinophil rate (p < 0.05), and a negative correlation (p < 0.001) was recognized between the neutrophil and the lymphocyte rates.     

HRTEM study of new series of oxycarbonitrate superconductors (Cu,C,N)Sr2Ca(n - 1)Cu(n)O(y) (n = 1-6)

Arrangements of Cu and anion groups (CO3 and NO3) in the charge-reservoir (CR) blocks of a series of new oxycarbonitrate superconductors (Cu,C,N)Sr2Ca(n - 1)Cu(n)O(y) (n = 1-6) were examined by means of electron diffraction and high-resolution transmission electron microscopy (HRTEM). The first three members with n = 1-3 [Tc = 33 K (n = 1), 91 K (n = 2), 90 K (n = 3)] show the 4a0-type superstructures with periodic arrangements, [-Cu-X-X-X-Cu-X-X-X-Cu-] (X = CO3, NO3), in the CR blocks. The third member (n = 3) partly contains the 2a0-type of superstructure with [-Cu-X-Cu-X-Cu] in the CR blocks. The fourth member with n = 4 (Tc = 113 K) contains only the 2a0-type of superstructure. The higher members, with n = 5 (Tc = 65 K) and n = 6 (Tc = 52 K), show no evidence of ordering in the CR blocks, suggesting random arrangements of Cu and anion groups.