The aim of the study was to develop and validate models that could predict the growth responses to GH therapy of individual children. Models for prediction of the initial one and 2-y growth response were constructed from a cohort of 269 prepubertal children (Model group) with isolated GH deficiency or idiopathic short stature, using a nonlinear multivariate data fitting technique. Five sets of clinical information were used. The "Basic model" was created using auxological data from the year before the start of GH treatment and parental heights. In addition to Basic model data, the other four models included growth data from the first 2 y of life, or IGF-I, or GH secretion estimated during a provocation test (AITT) or a spontaneous GH secretion profile.The performance of the models was validated by calculating the differences between predicted and observed growth responses in 149 new GH treated children (Validation group) who fulfilled the inclusion criteria used in the original cohort. The SD of these differences (SD res ) in the validation group was compared with the SD res for the model group. For the 1st y, the SD res for the Basic model was 0.28 SDscores. The lowest SD res (0.19 SDscores), giving the most narrow prediction interval, was achieved adding the 24h GH profile and data on growth from the first 2 y of life to the Basic model. The models presented permit estimation of GH responsiveness in children over a broad range in GH secretion, and with an accuracy of the models substantially better than when using maximal GH response during an provocation test. The predicted individual growth response, calculated using a computer program, can serve as a guide for evidence-based decisions when selecting children to GH treatment. Abbreviations GHD, GH deficiency GHI, GH insensitivity ISS, idiopathic short stature IGFBP-3, IGF binding protein 3 AITT, arginin-insulin tolerance test GH max , the estimated maximal GH levelThe diagnosis of severe GH deficiency (GHD) on the one hand or complete GH insensitivity (GHI) on the other, usually is obvious in the short child in whom appropriate studies have excluded other causes for growth failure. Among children forming the continuum between these two extremes, diagnosis is more challenging; that is, children with partial GHD or those considered to have partial GHI, who may be classified as idiopathic short stature (ISS). Despite investigations and discussions aimed at attaining consensus on the diagnostic discrimination between GHD and ISS (1, 2), none of the clinical measures used to date provide a reliable means for categorizing these patients and for predicting the value of GH therapy (3). The effect of the GH axis on statural growth in an individual child depends on the interaction between GH secretion and GH responsiveness. With better understanding of conditions causing GH resistance (4 -7), the need to consider responsiveness to GH, as well as secretion of GH when interpreting the growth of a child has become more apparent.Traditionally, the diagnosis of GHD relies ...

Haem A, a prosthetic group of many respiratory oxidases, is probably synthesized from haem B (protohaem IX) in a pathway in which haem O is an intermediate. Possible roles of the Bacillus subtilis ctaA and ctaB gene products in haem O and haem A synthesis were studied. Escherichia coli does not contain haem A. The ctaA gene on plasmids in E. coli resulted in haem A accumulation in membranes. The presence of ctaB together with ctaA increased the amount of haem A found in E. coli. Haem O was not detected in wild-type B. subtilis strains. A previously isolated B. subtilis ctaA deletion mutant was found to contain haem B and haem O, but not haem A. B. subtilis ctaB deletion mutants were constructed and found to lack both haem A and haem O. The results with E. coli and B. subtilis strongly suggest that the B. subtilis CtaA protein functions in haem A synthesis. It is tentatively suggested that if functions in the oxygenation/oxidation of the methyl side group of carbon 8 of haem O. B. subtilis CtaB, which is homologous to Saccharomyces cerevisiae COX10 and E. coli CyoE, also has a role in haem A synthesis and seems to be required for both cytochrome a and cytochrome o synthesis.

The phase behavior and microstructure at 25 °C in mixtures of the amphiphilic block copolymer Pluronic P104 (with the formula (EO)27(PO)61(EO)27, where EO is ethylene oxide and PO is propylene oxide), D2O, and p-xylene are presented. A rich phase behavior with both normal (“oil-in-water”) and reverse (“water-in-oil”) phases is observed. Two isotropic micellar solutions (normal and reverse micellar solutions) and six lyotropic liquid crystalline phases (normal and reverse micellar cubic, normal and reverse hexagonal, reverse bicontinuous cubic, and lamellar phases) are formed. The structural length scales in the liquid crystalline phases were determined from small-angle X-ray scattering. The interfacial area per PEO block varies in the range 110−155 Å2.

Two isothermal (25 °C) phase diagrams with the block copolymer (EO)43(PO)16(EO)43 and the block copolymer (EO)5(PO)68(EO)5, respectively, in water and p-xylene are presented (EO is ethylene oxide and PO is propylene oxide). The copolymers have approximately the same molecular weight, albeit are unbalanced in PEO/PPO block ratio. The amounts and relative proportions of the solvents can modulate the resulting microstructures, although the phase sequence observed depends on the relative PEO/PPO block ratio. The copolymer rich in EO forms predominantly normal (oil-in-water) structures while the copolymer rich in PO forms predominantly reverse (water-in-oil) structures.

Poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide) (PEO−PPO−PEO) block copolymers, commercially available as Poloxamers or Pluronics, are unique in forming ordered cubic phases consisting of reverse (water-in-oil) micelles. We set out to study the microstructure (form and dimension) as the reverse micelles order (from a micellar solution to a cubic lattice) with increasing block copolymer volume fraction and with increasing block copolymer molecular weight. The technique we used was small-angle neutron scattering (SANS) with solvent contrast variation. We selected four block copolymers with known phase behavior in water and p-xylene (Pluronics L44, L64, P84, and P104, all with the same PEO/PPO ratio and molecular formula (EO) x (PO) y (EO) x , where x = 10, 13, 19, 27 and y = 23, 30, 43, 61, respectively) and worked in a dilution line with fixed water to copolymer content (1.2 mol of water per mol of EO). The temperature effect (22 and 45 °C) was also studied. The scattering behavior indicates that the micelles are approximately spherical but polydisperse. We used a two-sphere model where we assumed that all the PEO and the water are in the core of the micelle and that PPO forms a p-xylene-solvated shell. The micellar radius then depends on the molecular weight and the temperature and is approximately constant with concentration. The structure of the reverse micelles is also compared to that of normal (oil-in-water) micelles.

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Heme A is a prosthetic group of many respiratory oxidases. It is synthesized from protoheme IX (heme B) seemingly with heme O as a stable intermediate. The Bacillus subtilis ctaA and ctaB genes are required for heme A and heme O synthesis, respectively (B. Svensson, M. Lübben, and L. Hederstedt, Mol. Microbiol. 10:193-201, 1993). Tentatively, CtaA is involved in the monooxygenation and oxidation of the methyl side group on porphyrin ring D in heme A synthesis from heme B. B. subtilis ctaA and ctaB on plasmids in both B. subtilis and Escherichia coli were found to result in a novel membrane-bound heme-containing protein with the characteristics of a low-spin b-type cytochrome. It can be reduced via the respiratory chain, and in the reduced state it shows light absorption maxima at 428, 528, and 558 nm and the alpha-band is split. Purified cytochrome isolated from both B. subtilis and E. coli membranes contained one polypeptide identified as CtaA by amino acid sequence analysis, about 0.2 mol of heme B per mol of polypeptide, and small amounts of heme A.

Synthesis of heme A from heme B (protoheme IX) most likely occurs in two steps with heme 0 as an intermediate. Bacillus subtilis CtaB, an integral membrane protein, functions in farnesylation of heme B to form heme 0. CtaA, also a membrane protein, is required for heme A synthesis from heme 0 and appears to be a monooxygenase and/or a dehydrogenase. Wild-type ctaA and ctaB expressed together from plasmids in B. subtilis resulted in CtaA containing equimolar amounts of low-spin heme B and heme A; this form of CtaA was named cyt ba-CTA. A mutant ctaB gene was identified and characterised. It encodes a truncated CtaB polypeptide. Wild-type ctaA and the mutant ctaB gene on plasmids resulted in CtaA containing mainly low-spin heme B; this variant was named cyt b-CTA. The heme B component in cyt ba-CTA and cyt b-CTA showed identical properties; a mid-point redox potential of +85 mV, an EPR g, , , signal at 3.7, and a split a-band light absorption peak. The heme A component in cyt ba-CTA showed a mid-point potential of +242 mV, an EPR g, , , signal at 3.5, and the a-band light absorption peak at 585 nm. It is suggested that the CtaA protein contains two heme binding sites, one for heme B and one for substrate heme. The heme B would play a role in electron transfer, i.e. function as a cytochrome, in the monooxygenase andor dehydrogenase reaction catalysed by CtaA whereas heme O/heme A would be substratelproduct.