Medial longitudinal arch development of school children : The College of Podiatry Annual Conference 2015: meeting abstracts

Background Foot structure is often classified into flat foot, neutral and high arch type based on the variability of the Medial Longitudinal Arch (MLA). To date, the literature provided contrasting evidence on the age when MLA development stabilises in children. The influence of footwear on MLA development is also unknown. Aim This study aims to (i) clarify whether the MLA is still changing in children from age 7 to 9 years old and (ii) explore the relationship between footwear usage and MLA development, using a longitudinal approach. Methods We evaluated the MLA of 111 healthy school children [age = 6.9 (0.3) years] using three parameters [arch index (AI), midfoot peak pressure (PP) and maximum force (MF: % of body weight)] extracted from dynamic foot loading measurements at baseline, 10-month and 22-month follow-up. Information on the type of footwear worn was collected using survey question. Linear mixed modelling was used to test for differences in the MLA over time. Results Insignificant changes in all MLA parameters were observed over time [AI: P = .15; PP: P = .84; MF: P = .91]. When gender was considered, the AI of boys decreased with age [P = .02]. Boys also displayed a flatter MLA than girls at age 6.9 years [AI: mean difference = 0.02 (0.01, 0.04); P = .02]. At baseline, subjects who wore close-toe shoes displayed the lowest MLA overall [AI/PP/MF: P < .05]. Subjects who used slippers when commencing footwear use experienced higher PP than those who wore sandals [mean difference = 31.60 (1.44, 61.75) kPa; post-hoc P = .04]. Discussion and conclusion Our findings suggested that the MLA of children remained stable from 7 to 9 years old, while gender and the type of footwear worn during childhood may influence MLA development. Clinicians may choose to commence therapy when a child presents with painful flexible flat foot at age 7 years, and may discourage younger children from wearing slippers when they commence using footwear

Thymic Atrophy and Apoptosis of CD4+CD8+ Thymocytes in the Cuprizone Model of Multiple Sclerosis.

Previous studies on the degenerative animal model of multiple sclerosis suggested that the copper-chelator cuprizone might directly suppress T-cell functions. Peripheral T-cell function in the cuprizone model has already been explored; therefore, in the present study, we investigated, for the first time, how cuprizone feeding affects the thymus, the organ of T-cell maturation and selection. We found that even one week of cuprizone treatment induced significant thymic atrophy, affecting the cortex over the medulla. Fluorescent microscopy and flow-cytometric analyses of thymi from cuprizone- and vehicle-treated mice indicated that eradication of the cluster of the differentiation-4 (CD4)-CD8 double-positive T-cell subset was behind the substantial cell loss. This result was confirmed with CD3-CD4-CD8 triple-staining experiments. Ultrastructurally, we observed degraded as well as enlarged mitochondria, myelin-bodies, large lipid droplets, and large lysosomes in the thymi of cuprizone-treated mice. Some of these features were similar to those in physiological and steroid-induced accelerated aging. According to our results, apoptosis was mainly of mitochondrial origin mediated by both caspase-3- and apoptosis inducing factor-mediated mechanisms. Additionally, mitogen activated protein kinase activation and increased pro-apoptotic B cell lymphoma-2 family protein expression were the major underlying processes. Our results do not indicate a functional relationship between cuprizone-induced thymus involution and the absence of inflammatory responses or the selective demyelination observed in the cuprizone model. On the other hand, due to the reversible nature of cuprizone's deleterious effects, the cuprizone model could be valuable in studying thymus regeneration as well as remyelination processes

Characterisation of cuprizone-induced cell death.

<p>Four week-old male mice were treated with cuprizone for one week. Type of cell death was determined using flow cytometry following double staining with FITC-labelled AnnexinV and propidium iodide thymus suspensions of untreated (Control, grey bars) and cuprizone-treated (CPZ, black bars) mice. Results are presented as representative dot-plots (A) and bar diagrams (B), mean + SEM (n≥9). Significant difference from control; **p<0.01, *** p<0.001. DN: live cells (lower left quadrant); AnnexinV: early apoptotic cells (lower right quadrant); PI: necrotic cells (upper left quadrant); DP: late apoptotic cells (upper right quadrant).</p

Effect of cuprizone on thymic epithelial cells.

<p>Four week-old male mice were treated with cuprizone for one week, then immune-staining (A) with FITC-labelled anti-EpCAM1 (green) and PE-labelled anti-Ly-51 (red) antibodies was performed on thymic sections of untreated (Control) and cuprizone-treated (CPZ) mice. Representative images (A) are presented of the green channel (top panels), the red channel (middle panels) and the merged channels (bottom panels) of three independent experiments, including at least three animals in each group for each experiment. Fluorescent photographs were taken using a 10x objective. The scale bar indicates 200 μm. In a parallel experiment, thymic MHC II and AIRE mRNA expression (B) was determined by using qPCR analysis in untreated (grey bars) and cuprizone-treated (black bars) mice. Results are presented as fold change, mean + SEM (n≥9). Significant difference from control; *p<0.05.</p

Macroscopic changes of the thymi upon cuprizone treatment.

<p>Four week-old male mice were treated with cuprizone for one week. Representative photographs (A) of the open chest of a control (Cont.) and a cuprizone-treated (CPZ) animal are demonstrated. Arrows point to the thymi of the mice. The scale bar indicates 5 mm. Thymus mass (B), body mass (C) and relative thymus mass (thymus tissue mass/ body mass) (E) of control (grey bars) and cuprizone-treated (black bars) animals are presented as bar diagrams, mean + SEM (n≥9). * denotes a significant difference from control p<0.05.</p

Effect of cuprizone treatment on death pathway and signalling proteins in the thymus.

<p>Four week-old male mice were treated with cuprizone for three days. Steady-state cytoplasmic levels of cytochrome C (Cyt C) (A), caspase 3 (casp 3) (A), cleaved caspase 3 (cleav. casp 3) (A) and nuclear apoptosis inducing factor (AIF) content (A), as well as cellular levels of Bad (B), BimEL (B), BimL (B) and Bax (B) were assessed in the thymi of untreated (Cont., grey bars) and cuprizone-treated (CPZ, black bars) mice by using specific primary antibodies and immunoblotting. The activation state of Bad (p-Bad) (B), JNK (p-JNK) (C), ERK (p-ERK) (C) and p38 MAPK (p-p38) (C) was also determined by using phosphorylation-specific primary antibodies and immunoblotting. GAPDH (A-C) and histone H1 (His H1) (A) were used as loading controls for cytoplasmic/cellular and nuclear fractions, respectively. Results are presented as representative immunoblots and bar diagrams, mean + SEM (n≥9). Significant difference from control; *p<0.05. Please note that the y-axis in B is broken to accommodate the very high Bax value.</p

Effect of cuprizone treatment on subcellular morphology.

<p>Four week-old male mice were treated with cuprizone for one week. Subcellular morphology was assessed in ultrathin thymic sections of control (A) and cuprizone-treated (B-E) mice. Representative images are presented of three independent experiments including at least three animals in each group for each experiment. Arrows indicate normal (A) and enlarged (B) mitochondria, a large lipid droplet (D), and large lysosomes packed with darkly stained material (E). Horizontal thin and vertical thick arrows in (C) point to myelin body and a degraded mitochondrion, respectively. Scale bars indicate 200 nm.</p