White matter tract signatures of the progressive aphasias

The primary progressive aphasias (PPA) are a heterogeneous group of language-led neurodegenerative diseases resulting from large-scale brain network degeneration. White matter (WM) pathways bind networks together, and might therefore hold information about PPA pathogenesis. Here we used diffusion tensor imaging and tract-based spatial statistics to compare WM tract changes between PPA syndromes and with respect to Alzheimer's disease and healthy controls in 33 patients with PPA (13 nonfluent/agrammatic PPA); 10 logopenic variant PPA; and 10 semantic variant PPA. Nonfluent/agrammatic PPA was associated with predominantly left-sided and anterior tract alterations including uncinate fasciculus (UF) and subcortical projections; semantic variant PPA with bilateral alterations in inferior longitudinal fasciculus and UF; and logopenic variant PPA with bilateral but predominantly left-sided alterations in inferior longitudinal fasciculus, UF, superior longitudinal fasciculus, and subcortical projections. Tract alterations were more extensive than gray matter alterations, and the extent of alteration across tracts and PPA syndromes varied between diffusivity metrics. These WM signatures of PPA syndromes illustrate the selective vulnerability of brain language networks in these diseases and might have some pathologic specificity.     

Primordium of an artificial Bruch’s membrane made of nanofibers for engineering of retinal pigment epithelium cell monolayers

Transplanted retinal pigment epithelium (RPE) cells hold promise for treatment of age-related macular degeneration (AMD) and Stargardt disease (SD), but it is conceivable that the degenerated host Bruch’s membrane (BM) as a natural substrate for RPE might not optimally support transplanted cell survival with correct cellular organization. We fabricated novel ultrathin three-dimensional (3-D) nanofibrous membranes from collagen type I and poly(lactic-co-glycolic acid) (PLGA) by an advanced clinical-grade needle-free electrospinning process. The nanofibrillar 3-D networks closely mimicked the fibrillar architecture of the native inner collagenous layer of human BM. Human RPE cells grown on our nanofibrous membranes bore a striking resemblance to native human RPE. They exhibited a correctly orientated monolayer with a polygonal cell shape and abundant sheet-like microvilli on their apical surfaces. RPE cells built tight junctions and expressed RPE65 protein. Flat 2-D PLGA film and cover glass as controls delivered inferior RPE layers. Our nanofibrous membranes may imitate the natural BM to such extent that they allow for the engineering of an in vivo-like human RPE monolayer that maintains the natural biofunctional characteristics. Such ultrathin membranes may provide a promising vehicle for a functional RPE cell monolayer implantation in the subretinal space in patients with AMD or SD.     

Luminescent Copolymer‐Rhenium(I) Hybrid Materials via Picolylamine‐Modified Poly(pentafluorophenyl acrylate)

The synthesis and photophysical properties of well‐defined polymer‐rhenium(I) hybrid materials is described. Reversible addition‐fragmentation chain transfer polymerization of pentafluorophenyl acrylate yields a parent homopolymer that serves as a reactive scaffold for the preparation of a series of new statistical copolymers containing pendent pyridyl functional groups in conjunction with various other repeat unit species. Attachment of [Re(CO)₃(phen)]⁺ fragments via coordination through the pendent pyridyl groups yields the hybrid metal‐copolymer materials. Photophysical studies confirm successful rhenium coordination as judged from the absorption and emission profiles of the hybrid materials and further verify that the polymeric scaffold has no discernable effect on the luminescent properties of the coordinated rhenium species.     

Meta-analysis of determinants for pet ownership in 12 European birth cohorts on asthma and allergies: a GA2LEN initiative

Background: Studies on pet ownership as a risk or protective factor for asthma and allergy show inconsistent results. This may be on account of insufficient adjustment of confounding factors. Aim: The objective of this study was to describe determinants of cat and dog ownership in European families with and without allergies. Methods: Within the EU‐funded network of excellence GA²LEN, we performed meta‐analyses with data from 12 ongoing European birth cohort studies on asthma and allergy. Each of the birth cohort studies enrolled between 485 and 4089 children. Pet ownership, allergic status (asthma, allergic rhinitis, eczema) of parents and siblings, parental education, access to ground floor, and number of people living at home were assessed by questionnaires. Results: Among the 25 056 families from seven European countries cats (14.9%) were more common than dogs (12.0%). Allergic family history significantly reduced the odds to own a cat (adjusted combined random‐effect OR 0.91; 95% CI 0.85–0.99), or dog (0.90; 0.86–0.94). A higher parental educational level had even more pronounced effects on cat (0.84; 0.71–0.98), and dog ownership (0.61; 0.54–0.70). Elder siblings reduced the odds to own cats, but not dogs. Convenient ground access significantly increased the odds, whereas crowding at home was not associated with cat or dog ownership. Conclusions: The chances to own a cat or dog were significantly reduced in allergic families, in parents with a higher educational level, and in homes without convenient ground access. In addition to parental allergies, social and housing factors should be considered as potential confounders in studies on pet exposure and allergic diseases.     

Early weight bearing versus delayed weight bearing in medial opening wedge high tibial osteotomy: a randomized controlled trial

Purpose

The need for a period of non-weight bearing after medial opening wedge high tibial osteotomy remains controversial. It is hypothesized that immediate weight bearing after medial opening wedge high tibial osteotomy would have no difference in functional scores at one year compared to delayed weight bearing.

Methods

Fifty patients, median age 54 years (range 40–65), with medial compartment osteoarthritis, underwent a medial opening wedge high tibial osteotomy utilizing a locking plate without bone grafting. Patients were randomized into an Immediate or a Delayed (2 months) weight bearing group. All patients were assessed at one-year follow-up and the two groups compared. The primary outcome measure was the IKS score. Secondary outcome measures included the IKDC score, the VAS pain score and rate of complications.

Results

The functional scores significantly improved in both groups. The IKS score increased from 142 ± 31 to 171 ± 26 in the Immediate group (p < 0.001) and from 148 ± 22 to 178 ± 23 in the Delayed group (p < 0.001). The IKDC score increased from 49 ± 17 pre-operatively to 68 ± 14 one-year post-operatively in the Immediate group (p < 0.0001) and from 44 ± 16 to 69 ± 19 in the Delayed group (p < 0.001). The average VAS for pain 2 months after surgery was 3 ± 3 in the Immediate group and 3 ± 2 in the Delayed (n.s.). There was no significant difference between the two groups in any of the outcome measures. The mean mechanical femorotibial angle changed from 6° of varus (0°–15° of varus, SD = 3°) to 4° of valgus (5°–11° of valgus, SD = 3°) in the Immediate group and from 5° of varus (0°–10° of varus, SD = 3°) to 3° of valgus (2° of varus to 8° of valgus, SD = 3°) in the Delayed group. No difference was seen between groups, and no loss of correction was observed in any patient. Two cases of non-union occurred, one in each group. One infection and one deep vein thrombosis occurred in the Immediate group.

Conclusion

Immediate weight bearing after medial opening wedge high tibial osteotomy had no effect on functional scores at 1 year follow-up and did not significantly increase the complication rate. Immediate weight bearing after medial opening wedge high tibial osteotomy appears to be safe and can allow some patients a quicker return to activities of daily living and a decreased convalescence period.

Level of evidence

II.

     

Effect of adhesion boosters on indirect bracket bonding

Objective:To determine the influence of two adhesion boosters on shear bond strength and on the bond failure location of indirectly bonded brackets.Materials and Methods:Sixty bovine incisors were randomly divided into three groups (n  =  20), and their buccal faces were etched using 37% phosphoric acid. In group 1 (control), brackets were indirectly bonded using only Sondhi adhesive. In groups 2 and 3, the adhesion boosters Enhance Adhesion Booster and Assure Universal Bonding Resin, respectively, were applied before bonding with Sondhi. Maximum bond strength was measured with a universal testing machine, and the location of bond failure was evaluated using the Adhesive Remnant Index (ARI). One-way analysis of variance followed by the Tukey test (P < .05) was used to compare the shear bond strength among groups, and the differences in ARI scores were evaluated using the Kruskal-Wallis test (P < .05). The Pearson correlation coefficient was calculated to determine whether there was any correlation between bond strength and ARI scores.Results:The mean shear bond strength in group 3 was significantly higher (P < .01) than in the other groups. Evaluation of the locations of bond failure revealed differences (P < .05) among the three groups. There was a moderate correlation between bond strength and ARI scores within group 3 (r  =  0.5860, P < .01).Conclusion:In vitro shear bond strength was acceptable in all groups. The use of the Assure adhesion booster significantly increased both the shear bond strength of indirectly bonded brackets and the amount of adhesive that remained on the enamel after bracket debonding.