Growth and Treatment in Congenital Adrenal Hyperplasia: An Observational Study from Diagnosis to Final Height.

Introduction Congenital adrenal hyperplasia (CAH) due to 21α-hydroxylase deficiency results in inadequate cortisol and aldosterone synthesis and concomitant overproduction of adrenal androgens. Despite adequate replacement, impaired growth and overweight remains a clinical challenge. The main objective was to investigate the differences in growth, final height (FH), and body mass index (BMI) between different CYP21A2 genotype groups and glucocorticoid treatment strategies during the different phases of growth. Methods This is a population based observational cohort study from diagnosis to final height (FH). A total of 86 subjects were diagnosed with CAH in Sweden during 1989-1994. Eighty subjects were followed until FH. There were no intervention apart from the clinical standard of care treatment for CAH. The main outcome measure was the corrected FH standard deviation score (cFH SDS) and its correlation with genotype, accumulated total glucocorticoid dose, and treatment strategy. In addition, BMI and growth trajectories during infancy, childhood, and adolescence were studied. Results FH was shorter in patients with the more severe CYP21A2 genotypes. Treatment doses of glucocorticoid were within the international treatment recommendations (10-15 mg/m2). Patients with the null and I2 splice genotypes lost approximately 1 SD in final height whereas patients with the milder genotypes (I172N, P30L and V281L) were within 0.5 to 0 SDS from target height. cFH SDS was negatively affected by the use of prednisolone but did not correlate with overall glucocorticoid treatment dose calculated as hydrocortisone equivalents. BMI at 18 years was higher in patients treated with prednisolone but did not correlate with genotype. Conclusions Corrected final height was more affected in patients with severe CYP21A2 genotypes. The addition of a low dose of prednisolone to the hydrocortisone treatment, despite an equivalent total dose of glucocorticoids, was associated with shorter FH and higher BMI in growing subjects with CAH.

Synthesis of polycaprolactone-grafted microfibrillated cellulose for use in novel bionanocomposites--influence of the graft length on the mechanical properties.

In the present work, microfibrillated cellulose (MFC) made from bleached sulfite softwood dissolving pulp was utilized to reinforce a poly(ε-caprolactone) (PCL) biopolymer matrix. To improve the dispersibility of the hydrophilic MFC in the nonpolar matrix and the interfacial adhesion in the composite material, we covalently grafted the MFC with PCL via ring-opening polymerization (ROP) of ε-caprolactone (ε-CL). To be able to investigate the effect of the PCL graft length on the mechanical properties of the composite material, we performed ROP to different molecular weights of the grafts. Bionanocomposites containing 0, 3, and 10 wt % MFC were prepared via hot pressing using both unmodified and PCL grafted MFC (MFC-g-PCL) as reinforcement. PCL grafting resulted in improved dispersion of the MFC in a nonpolar solvent and in the PCL matrix. The mechanical testing of the biocomposites showed an improvement in the mechanical properties for the PCL grafted MFC in comparison to ungrafted MFC. It was also shown that there was an impact on the mechanical properties with respect to the PCL graft lengths, and the strongest biocomposites were obtained after reinforcement with MFC grafted with the longest PCL graft length.

Adhesion dynamics for cellulose nanocomposites.

The efficiency of poly(ε-caprolactone) (PCL) as a matrix polymer for cellulose nanocomposites has been investigated at the macromolecular contact level using atomic force microscopy in a colloidal probe configuration. Model cellulose microspheres grafted with PCL were prepared via ring-opening polymerization. Force measurements between the functionalized particles revealed the adhesion to be highly dependent on the contact time because of a diffusion-controlled mechanism. Moreover, an increase of the temperature to 60 degrees C (close to T(m) for the PCL graft) greatly enhanced the adhesion at the polymer-polymer interface, demonstrating the importance of entanglements in the annealing of composite materials.

Grafting of cellulose fibers with poly(epsilon-caprolactone) and poly(L-lactic acid) via ring-opening polymerization.

In this study, ring-opening polymerization (ROP) of epsilon-caprolactone (epsilon-CL) and L-lactide (L-LA) has been performed from cellulose fibers. The hydroxyl groups on cellulose act as initiators in the polymerization, and the polymers are covalently bonded to the cellulose fiber. As an attempt to introduce more available hydroxyl groups on the surface, and thereby obtain higher grafting efficiency in the ROP of epsilon-CL and L-LA, unmodified paper was modified with xyloglucan-bis(methylol)-2-methylpropanamide (XG-bis-MPA) and 2,2-bis(methylol)propionic acid (bis-MPA), respectively. The grafted substrates were characterized via Fourier transform infrared spectroscopy (FTIR), contact angle measurement, atomic force microscopy, and enzymatic degradation. The results showed a successful grafting of poly(epsilon-caprolactone) (PCL) and poly(L-lactic acid) (PLLA) from the cellulose fiber surfaces. Furthermore, the results showed an improved grafting efficiency after activation of the cellulose surface with bis-MPA, and showed that the amount of grafted polymer could be controlled by the ratio of added free initiator to monomer.