No abstract

Cystathionine ␥-synthase (CGS) catalyzes the first committed step of Met biosynthesis in plants. We have previously shown that expression of the gene for CGS is feedback-regulated at the level of mRNA stability, and that the amino acid sequence encoded by the first exon of the CGS gene itself is responsible for the regulation (Chiba, Y., Ishikawa, M., Kijima, F., Tyson, R. H., Kim, J., Yamamoto, A., Nambara, E., Leustek, T., Wallsgrove, R. M., and Naito, S. (1999) Science 286, 1371-1374). To identify the functional region within CGS exon 1, deletion analysis was performed. The results showed that the 41-amino acid region of exon 1 highly conserved among plants is necessary and sufficient for the regulation. Analyses of in vivo and in vitro generated mutations that abolish the regulation identified the functionally important amino acids as 11-13 residues within this conserved region. The importance of these residues was confirmed by deletion analysis within the conserved region. These studies identified the functional region of CGS exon 1 required for the posttranscriptional autoregulation of the CGS gene as (A)RRNCSNIGVAQ(I), with uncertainty of the first and last residues. This sequence is almost perfectly conserved among CGS sequences of higher plants but cannot be found elsewhere in the public databases.

No abstract

The prediction of moisture transfer within concrete is necessary in order to evaluate its durability, because moisture transfer is related to shrinkage cracks and the transfer of chloride ions. Moisture transfer within concrete during drying has been analysed by many investigators using a non-linear diffusion equation. In the present paper, a comprehensive analytical procedure using a diffusion equation is established by comparing calculated results with experimental data for a wide range of concrete mix proportions. These experiments involved observing the effect of one-face drying and six-face drying on the water content profiles and mass decreases in prismatic specimens. The values of the coefficient required for the analysis are reported for a wide range of water/cement ratios, and the effect of these coefficients on the calculated results is discussed.

A series of aromatic polyamides of high molecular weight was synthesized by the low-temperature solution polycondensation of 2,5-bis[ [(methoxycarbonyl)ethyl]thio]-1,4-phenylenediamine with aromatic diacid chlorides. The aromatic polyamides with pendant [ (methoxycarbonyl)ethyl] thio groups had inherent viscosities in the range of 1.32-2.24 dL-g"1. The introduction of bulky and polar pendant [(methoxycarbonyl)ethyl] thio groups in the polyamides improved the solubility in organic solvents. The soluble precursor polyamides were subjected to thermal cyclization at 360 °C in an inert atmosphere to convert them to the corresponding polybenzothiazoles with high molecular weights. The mechanism of the thermal cyclization is discussed based on the pyrolysis GC-MS analysis of the polyamides. The precursor polyamides were also characterized by X-ray diffraction studies. Dynamic mechanical analysis showed that the polyamide obtained from the diamine and 4,4'-oxydibenzoyl chloride and the corresponding polybenzothiazole had glass transition temperatures of 95 and 340 °C, respectively. The polybenzothiazoles obtained from the precursor polyamides showed excellent thermal properties which were comparable to those of the polybenzothiazoles synthesized by solution polycondensation in polyphosphoric acid.

A test method for uniaxial tension test of concrete to obtain tension softening curves has not been established yet, because there are several difficulties in performing the test. In the past 40 years, many different test conditions, sometimes even completely opposite conditions have been adopted. In order to show which conditions should be selected and why the conditions should be selected, theoretical and experimental investigation was carried out. For the experiment, prismatic specimens with notches and an originally designed gear system preventing secondary flexure were adopted. It was shown that the tension softening curves were successfully monitored by the present procedure with a high success ratio. A practical test procedure of uniaxial tension test of concrete was proposed based on the investigation. I~$UME

The purpose of this study was to determine whether pulmonary hemodynamic abnormalities relate to manifestations of allergic asthma. In 448 patients with congenital heart disease the relationships between asthma and age or pulmonary arterial blood (PA) flow were studied. Asthma (allergic and non‐allergic) was more common in 39 (19%) of 201 patients with high PA flow, compared with the incidence in those with normal PA flow (6/117, 5%; P < 0.001) and reduced PA flow (1/130, 1%; P < 0.05). In the high PA flow group, the frequency of asthma declined significantly (P < 0.01) with age, from 25–26% in the 6 month‐5 year patient group to 5% in the 6–12 year old patients. The frequency of asthma, including allergic type, was significantly (P < 0.01) greater in patients with pulmonary hypertension (15/24, 63%) than in those without (10/77, 13%) at the age of 6 months to 1 year. Asthma in the high PA flow group was associated with other allergic diseases in 30 (77%) of 39 patients, including food allergy in nine (23%), atopic dermatitis in 14 (36%), allergic rhinitis in seven (18%) and abnormally high total IgE levels in 14 (36%). These findings suggest that high pulmonary flow or pulmonary hypertension enhances the manifestation of allergic disease, particularly asthma.

Abstract. This study examines the exacerbating factors of hyeruricaemia in patients with cyanotic congenital heart disease (CCHD). We studied 59 CCHD patients aged 1 month-30 years. The following variables were assessed: serum uric acid levels, red blood cell count, haemoglobin, hematocrit, partial oxygen pressure and arterial oxygen saturation. Uric acid excretion and renal function were also measured in ten patients with serum levels of uric acid greater than 8 mg/dl (hyperuricaemia group). Serum uric acid level correlated significantly with age and severity of polycythaemia. However, it did not correlate with partial oxygen pressure or arterial oxygen saturation. Uric acid excretion was measured in hyperuricaemia group. Urinary uric acid excretion (24 h) was within normal limits in infants but markedly lower in patients over 15 years of age. The aetiology of hyperuricaemia and decreased uric acid fractional excretion and clearance in infants appears to be secondary to diminished excretion of uric acid in concert with uric acid overproduction. Hyperuricaemia in adolescents and adults with CCHD, however, results mainly from age-related impairment of uric acid excretion.