Proton-exchange mechanism of specific Cs+ adsorption via lattice defect sites of Prussian blue filled with coordination and crystallization water molecules.

We have revealed the fundamental mechanism of specific Cs(+) adsorption into Prussian blue (PB) in order to develop high-performance PB-based Cs(+) adsorbents in the wake of the Fukushima nuclear accident. We compared two types of PB nanoparticles with formulae of Fe(III)4[Fe(II)(CN)6]3·xH2O (x = 10-15) (PB-1) and (NH4)0.70Fe(III)1.10[Fe(II)(CN)6]·1.7H2O (PB-2) with respect to the Cs(+) adsorption ability. The synthesised PB-1, by a common stoichiometric aqueous reaction between 4Fe(3+) and 3[Fe(II)(CN)6](4-), showed much more efficient Cs(+) adsorption ability than did the commercially available PB-2. A high value of the number of waters of crystallization, x, of PB-1 was caused by a lot of defect sites (vacant sites) of [Fe(II)(CN)6](4-) moieties that were filled with coordination and crystallization water molecules. Hydrated Cs(+) ions were preferably adsorbed via the hydrophilic defect sites and accompanied by proton-elimination from the coordination water. The low number of hydrophilic sites of PB-2 was responsible for its insufficient Cs(+) adsorption ability.

Empirical method for prediction of the coordination environment of Eu(III) by time-resolved laser-induced fluorescence spectroscopy.

The number of water molecules in the inner-sphere (N(H2O)) was determined for Eu(III) and the strength of ligand field (R(E/M)) was evaluated for a variety of coordination environments from the luminescence lifetime and the relative intensity at 615 nm and at 592 nm, by time-resolved laser-induced fluorescence spectroscopy. When R(E/M) and deltaN(H2O) for Eu(III) with a known coordination environment were plotted clear regularity was apparent between the location of the R(E/M)-deltaN(H2O) plot and the coordination environment of Eu(III). Here, deltaN(H2O) was calculated by use of the equation, deltaN(H2O)=9-N(H2O). Unknown coordination environments of Eu(III) can, in turn, be characterized, including both the inner- and the outer-sphere, simply by plotting R(E/M) and deltaN(H2O) for Eu(III) on the diagram. This empirical method is effective for prediction of the coordination environment of hydrated and complexed Eu(III) in solutions and that of the adsorbed Eu(III) on ion-exchange resins and by microorganisms.

Hyponatremia in central partial diabetes insipidus due to postoperative hypothalamic tumor.

We report the case of a 4-year-old boy with a postoperative hypothalamic tumor, who exhibited unusual water and electrolyte disturbance. This developed as a late manifestation during the course of central diabetes insipidus (DI), which started when the patient was 2 years old. Clinically, hyponatremia and DI appeared alternately within 1 day. The hyponatremia (lowest value Na+ 115 mmol/I) was associated with afebrile convulsions. Assessment of fluid status revealed that the patient had a reduced capacity for arginine vasopressin(AVP) secretion (partial DI), which was not physiologically regulated and which was not concomitantly sufficient to produce maximally concentrated urine and allow the production of maximally diluted urine. This defective osmoreceptor function in association with the previously existing reduced capacity for AVP release seemed to be responsible for the fluid disturbance in the patient. The administration of nasal 1-desamino-8D-arginine vasopressin (DDAVP) only when urine output was increased, instead of regular administration at a fixed time, prevented both worsening of hyponatremia and development of DI.

Effect of testosterone on bone density and bone metabolism in adolescent male hypogonadism.

To assess the influence of gonadal steroid testosterone (T) on bone mineral status in males during puberty, we observed the response of cortical bone density and serum biochemical parameters of bone metabolism to T treatment in 12 adolescent patients with hypogonadotropic hypogonadism (11 with both gonadotropin and growth hormone deficiency and one with isolated gonadotropin deficiency). The 12 patients aged 15 to 21 years (Tanner stage I to II) were divided into two groups: group 1 (n = 6) given T treatment for 2 consecutive years, and group 2 (n = 6) without T treatment for the first year and then with T treatment for the second year. Cortical bone density measured in the radius was less than the age-matched mean value for normal subjects in all 12 patients (groups 1 and 2) at the start of the study. Bone density in group 1 increased significantly during the 2-year T treatment period, but did not increase in group 2 during the first year without T treatment, although an increase was observed during the subsequent year with T treatment. Among circulating biochemical factors such as osteocalcin, parathyroid hormone (PTH), 25-hydroxyvitamin D (25-OHD), and 1,25-dihydroxyvitamin D [1,25-(OH)2D], only osteocalcin showed an increase in response to T treatment in both groups. Levels of insulin-like growth factor-I (IGF-I) remained consistently low and did not change in any patients except one with isolated gonadotropin deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Central diabetes insipidus in hypoxic brain damage.

We describe two children who after cardiopulmonary arrest developed hypernatremia at the terminal stage. Urinary antidiuretic hormone concentration was very low, indicating central diabetes insipidus. These cases illustrate the necessity of alertness to the development of central diabetes insipidus in patients with severe hypoxic brain damage.

Fatty acid and prostaglandin metabolism in children with diabetes mellitus. II. The effect of evening primrose oil supplementation on serum fatty acid and plasma prostaglandin levels.

Our previous study demonstrated that levels of dihomo-gamma-linolenic acid (DGLA) and arachidonic acid in serum total lipids decreased in association with increased plasma levels of prostaglandins E2 (PGE2) and F2 alpha (PGF2 alpha) in patients with insulin-dependent diabetes mellitus. In this study, 11 children with insulin-dependent diabetes mellitus completed a double-blind, placebo-controlled study to assess the effect of dietary supplementation with gamma-linolenic acid (GLA) on serum essential fatty acid and plasma PGE2 and PGF2 alpha levels. GLA was given as the seed oil from the evening primrose (EPO) and all patients received either EPO capsules (containing 45 mg of GLA and 360 mg of linoleic acid) or indistinguishable placebo capsules for 8 months. Initially patients took 2 capsules daily for 4 months then 4 capsules daily for a further 4 months. All patients were assessed at the start of the study, after 4 months and at the end of the study, by measuring serum essential fatty acid and plasma PGE2 and PGF2 alpha levels. After administration of 4 capsules daily the DGLA levels increased and PGE2 levels decreased significantly (p less than 0.01) in the EPO compared with the placebo group. Neither fatty acid nor PGE2 and PGF2 alpha levels were altered by administration of 2 EPO capsules daily. This suggests that the altered essential fatty acid and PG metabolism in diabetes may be reversed by direct GLA supplementation.