The effect of medial only versus medial and lateral hamstring lengthening on transverse gait parameters in cerebral palsy.

Benefits of hamstring lengthening surgery on the sagittal plane in children with cerebral palsy have been previously demonstrated, but there is limited information on its effects on the transverse plane. This study compared the effects of medial hamstring lengthening (MHL) with those of medial and lateral hamstring lengthening (MLHL) procedures in the transverse plane. Children with gross motor function classification system (GMFCS) levels I-III who had MHL or MLHL were included. Baseline, short- (1-2 years), and long-term (3+ years) postoperative three-dimensional gait analysis outcomes were compared using analysis of variance. Children were excluded if they had concurrent osteotomies or tendon transfers. One hundred fifty children (235 limbs) were included, with 110 limbs in the MHL group (age 8.5 ± 4.1 years, GMFCS I-27%, II-52%, and III-21%) and 125 limbs in the MLHL group (age 10.0 ± 4.0 years, GMFCS I-23%, II-41%, and III-37%). Time between surgery and short- and long-term follow-up gait analysis was 1.5 ± 0.6 years and 6.6 ± 2.9 years, respectively. Transmalleolar axis became more external after MHL at both short and long terms ( P < 0.05), whereas there were only significant differences at long term in MLHL ( P < 0.05). Although hamstring lengthening has a positive impact on stance phase knee extension in children with cerebral palsy, intact lateral hamstrings after MHL likely contribute to increased tibial external rotation after surgery. Significant increases in external rotation at the knee in the long term are likely related to a trend present with growth in children with cerebral palsy rather than a direct result of surgical intervention.

Engineering matrix-free laser desorption ionization mass spectrometry using glancing angle deposition films.

RATIONALE: Thin, nanoporous films fabricated using Glancing Angle Deposition (GLAD) technology are demonstrated for solid matrix laser desorption/ionization mass spectrometry (SMALDI-MS). GLAD allows facile engineering of nanoporosity, film thickness, post alignment, and material composition, as demonstrated here by the fabrication of Co-GLAD and Si-GLAD films for SMALDI, and by exploration of the SMALDI performance as a function of thickness, post density, and angle of the post relative to surface normal. METHODS: GLAD films were prepared by electron beam evaporation onto silicon substrates, using steep angles of incidence for the vacuum deposition, with computer controlled substrate rotation. LDI from the GLAD films was evaluated using an MDS-Sciex time-of-flight (TOF) MALDI mass spectrometer. RESULTS: Co-GLAD films give a limit of quantitation of 6 fmol for complex carbohydrate derivatives, and slanted-post Si-GLAD films show up to three times higher sensitivity than vertical post structures. Reproducibility of both Si and Co films is much higher than conventional MALDI methods for m/z below at least 2100 Da. Both reproducibility and detection limits are comparable to or better than other nano-structured materials. Co-GLAD films are significantly better in performance than Co powders or Co thin films on silicon substrates previously evaluated. CONCLUSIONS: The flexibility of GLAD for thin film fabrication of LDI materials is demonstrated by the range of nanoporous materials that can be grown, and the fine control over structural conformation, thickness and porosity. Copyright © 2017 John Wiley & Sons, Ltd.

Effect of interleukin-1ß treatment on co-cultures of human meniscus cells and bone marrow mesenchymal stromal cells.

BACKGROUND: Interleukin-1ß (IL-1ß) is a major mediator of local inflammation present in injured joints. In this study, we aimed at comparing the effect of IL-1ß on engineered tissues from MCs, BMSCs and co-cultured MCs and BMSCs. METHODS: We compared the effect of IL-1ß in 3 groups: (1) MCs, (2) BMSCs and, (3) co-cultures of MCs and BMSCs. We selected 1 to 3 ratio of MCs to BMSCs for the co-cultures. Passage two (P2) human BMSCs were obtained from two donors. Human MCs were isolated from menisci of 4 donors. Mono-cultures of MCs and BMSCs, and co-cultures of MCs and BMSCs were cultured in chondrogenic medium with TGFß3, as cell pellets for 14 days. Thereafter, pellets were cultured for 3 more days in same medium as before with or without IL-1ß (500 pg/ml). Pellets were assessed histologically, biochemically and by RT-PCR for gene expression of aggrecan, sox9, MMP-1, collagens I and II. Statistics was performed using one-way ANOVA with Tukey's post-tests. RESULTS: Co-cultured pellets were the most intensely stained with safranin O and collagen II. Co-cultured pellets had the highest expression of sox9, collagen I and II. IL-1ß treatment slightly reduced the GAG/DNA of co-cultured pellets but still exceeded the sum of the GAG/DNA from the proportion of MCs and BMSCs in the co-cultured pellets. After IL-1ß treatment, the expression of sox9, collagen I and II in co-cultured pellets was higher compared to their expression in pure pellets. IL-1ß induced MMP-1 expression in mono-cultures of MCs but not significantly in mono-cultures of BMSCs or in co-cultured pellets. IL-1ß induced MMP-13 expression in mono-cultured pellets of BMSCs and in co-cultured pellets. CONCLUSIONS: Co-cultures of MCs and BMSCs resulted in a synergistic production of cartilaginous matrix compared to mono-cultures of MCs and BMSCs. IL-1ß did not abrogate the accumulated GAG matrix in co-cultures but mediated a decreased mRNA expression of aggrecan, collagen II and Sox9. These results strengthen the combinatorial use of primary MCs and BMSCs as a cell source for meniscus tissue engineering by demonstrating retention of fibrochondrogenic phenotype after exposure to IL-1ß.

Microchannels filled with diverse micro- and nanostructures fabricated by glancing angle deposition.

The integration of porous structures into microchannels is known to enable unique and useful separations both in electrophoresis and chromatography. Etched pillars and other nanostructures have received considerable interest in recent years as a platform for creating microchannels with pores tailored to specific applications. We present a versatile method for integration of three-dimensionally sculptured nano- and micro-structures into PDMS microchannels. Glancing angle deposition was used to fabricate nanostructures that were subsequently embedded in PDMS microchannels using a sacrificial resist process. With this technique, an assortment of structures made from a wide selection of materials can be integrated in PDMS microchannels; some examples of this versatility, including chiral and chevron nanostructures, are demonstrated. We also present a working device made using this process, separating 6/10/20 kbp and 10/48 kbp DNA mixtures in a DNA fractionator containing GLAD-deposited SiO(2) vertical posts as the separating medium. The separation mechanism was verified to resemble that found in prior fractionation devices, using total internal reflection fluorescence microscopy. GLAD fabrication enables insertion of three-dimensional structures into microchannels that cannot be fabricated with any existing techniques, and this versatility in structural design could facilitate new developments in on-chip separations.

Matrix-free laser desorption/ionization mass spectrometry using silicon glancing angle deposition (GLAD) films.

Glancing angle deposition (GLAD) was used to fabricate nanostructured silicon (Si) thin films with highly controlled morphology for use in laser desorption/ionization mass spectrometry (DIOS-MS). Peptides, drugs and metabolites in the mass range of 150-2500 Da were readily analyzed. The best performance was obtained with 500 nm thick films deposited at a deposition angle of 85 degrees . Low background mass spectra and attomole detection limits were observed with DIOS-MS for various peptides. Films used after three months of dry storage in ambient conditions produced mass spectra with negligible low-mass noise following a 15 min UV-ozone treatment. The performance of the Si GLAD films was as good as or better than that reported for electrochemically etched porous silicon and related materials, and was superior to matrix-assisted laser desorption/ionization (MALDI)-MS for analysis of mixtures of small molecules between 150-2500 Da in terms of background chemical noise, detection limits and spot-to-spot reproducibility. The spot-to-spot reproducibility of signal intensities (100 shots/spectrum) from 21 different Si GLAD film targets was +/-13% relative standard deviation (RSD). The single shot-to-shot reproducibility of signals on a single target was +/-19% RSD (n = 7), with no indication of sweet spots or mute spots.

Miniaturized planar chromatography using office peripherals.

High-performance thin-layer chromatography is a separation technique commonly used to identify and quantify components in chemical mixtures. Sophisticated analytical tools are required to extract the full analytical power from this technique and especially for miniaturized planar chromatography its utility has not been harnessed. A new approach uses an elegant, simplified system assembled from ordinary consumer printers and scanners to perform separations on monolithic and nanostructured ultrathin-layer phases. This system is shown to outperform existing planar chromatographic tools for analysis on miniaturized plates. Analysis can be completed in a manner of minutes, running numerous samples in parallel at a reduced cost, with very low sample and reagent volumes, all using a familiar computer interface with common office peripherals.

Ultrathin layer chromatography on nanostructured thin films.

Ultrathin layer chromatography (UTLC) is a relatively new variant of thin layer chromatography, with a 10mum thick monolithic silica sorbent layer that gives faster separations with lower limits of detection and reduced analyte and solvent volumes. We have produced UTLC plates with controllable nanostructure and thickness, and show that the layer separation characteristics depends on the film nanostructure. We also show that layers made with in-plane anisotropic nanostructures will exhibit a decoupling effect, where the analyte spots do not develop in the same direction as the solvent front movement. The added layer morphology and material selection adds a degree of freedom to UTLC, and may have applications in multi-dimensional TLC.