Ankle kinematics describing gait agility: Considerations in the design of an agile ankle-foot prosthesis

The designs of available lower extremity powered prostheses are focused on a single degree of freedom (DOF) in sagittal plane, allowing the control of their ankle joints in dorsiflexion and plantarflexion. The human gait however, shows that the ankle movements in both sagittal and frontal planes are significant even during walking on a straight path. Additionally, there is a significant change in the ankle movements during straight walking compared to turning and cutting, especially in frontal plane. A better understanding of the ankle characteristics in both sagittal and frontal planes may result in the design of significantly more effective lower extremity prostheses that mimic the ankle function and improve the agility of gait. In this paper, the ankle rotations are estimated during step turn and cutting to provide evidence for necessity of a multi-axis design while providing the preliminary design parameters for a prototype multi-axis powered ankle-foot prosthesis. It is shown that the proposed cable-driven prototype is capable of closely mimicking the ankle movements in both sagittal and frontal planes during turning and walking on a straight path

Malnutrition Is Associated with Diabetic Retinopathy in Patients with Type 2 Diabetes

Background. The relationship between malnutrition and diabetic retinopathy (DR) is still unclear. The purpose of this study is to investigate the relationship between malnutrition and DR in type 2 diabetic patients. Methods. A cross-sectional study was conducted on 612 patients with type 2 diabetes mellitus. Four malnutrition assessment tools: Global Leadership Initiative on Malnutrition (GLIM) criteria, controlling nutritional status (CONUT), nutritional risk index (NRI), and prognostic nutritional index (PNI), were applied to assess the nutritional status of the study population. The association between malnutrition and DR was examined using multivariable logistic regression and ordered logistic regression. Results. The proportion of malnutrition varied from 10.0% to 34.3% in total patients and from 16.3% to 45.1% in DR patients across the assessment tools. DR patients were more likely to be malnourished than patients without DR. The adjusted odds ratios (aOR) and 95% confidence interval (CI) for DR of malnutrition defined by different tools were 1.86 (1.01-3.14) for GLIM criteria, 1.67 (1.04-2.70) for NRI, and 2.24 (1.07-4.69) for PNI. The aOR and 95% CI for the severity of DR of malnutrition defined by different tools were 1.99 (1.12-3.51) for GLIM criteria, 1.65 (1.06-2.58) for NRI, and 2.51 (1.31-4.79) for PNI. Conclusions. Malnutrition was common in DR patients, and it was closely linked to the presence and severity of DR. Diabetic patients with DR should undergo nutritional assessment and early treatment of malnutrition to prevent the onset or progression of DR

Mutation Spectrum of Common Deafness-Causing Genes in Patients with Non-Syndromic Deafness in the Xiamen Area, China

<div><p>In China, approximately 30,000 babies are born with hearing impairment each year. However, the molecular factors causing congenital hearing impairment in the Xiamen area of Fujian province have not been evaluated. To provide accurate genetic testing and counseling in the Xiamen area, we investigated the molecular etiology of non-syndromic deafness in a deaf population from Xiamen. Unrelated students with hearing impairment (<i>n</i> = 155) who attended Xiamen Special Education School in Fujian Province were recruited for this study. Three common deafness-related genes, <i>GJB2</i>, <i>SLC26A4</i>, and <i>mtDNA12SrRNA</i>, were analyzed using all-exon sequencing. <i>GJB2</i> mutations were detected in 27.1% (42/155) of the entire cohort. The non-syndromic hearing loss (NSHL) hotspot mutations c.109G>A (p.V37I) and c.235delC were found in this population, whereas the Caucasian hotspot mutation c.35delG was not. The allelic frequency of the c.109G>A mutation was 9.03% (28/310), slightly higher than that of c.235delC (8.39%, 26/310), which is the most common <i>GJB2</i> mutation in most areas of China. The allelic frequency of the c.109G>A mutation was significantly higher in this Xiamen’s deaf population than that in previously reported cohorts (P = 0.00). The <i>SLC26A4</i> mutations were found in 16.77% (26/155) of this cohort. The most common pathogenic allele was c.IVS7-2A>G (6.13%, 19/310), and the second most common was the c.1079C>T (p.A360V) mutation (1.94%, 6/310) which has rarely been reported as a hotspot mutation in other studies. The mutation rate of <i>mtDNA12SrRNA</i> in this group was 3.87% (6/155), all being the m.A1555G mutation. These findings show the specificity of the common deaf gene-mutation spectrum in this area. According to this study, there were specific hotspot mutations in Xiamen deaf patients. Comprehensive sequencing analysis of the three common deaf genes can help portray the mutation spectrum and develop optimal testing strategies for deaf patients in this area.</p></div

<i>GJB2</i> genotypes of deaf patients from Xiamen special education school.

<p><i>GJB2</i> genotypes of deaf patients from Xiamen special education school.</p

Protein alignment showing conservation of residues GJB2 V670 across six species.

<p>An alignment of the SLC26A4 amino acid sequence of six species suggested the evolutionary conservation of c.2009T>C (p.V670A).</p

<i>SLC26A4</i> genotypes of deaf patients from Xiamen special education school.

<p>Note:</p><p>*: stop codon</p><p><i>SLC26A4</i> genotypes of deaf patients from Xiamen special education school.</p

MiR-155 Enhances Insulin Sensitivity by Coordinated Regulation of Multiple Genes in Mice

<div><p>miR-155 plays critical roles in numerous physiological and pathological processes, however, its function in the regulation of blood glucose homeostasis and insulin sensitivity and underlying mechanisms remain unknown. Here, we reveal that miR-155 levels are downregulated in serum from type 2 diabetes (T2D) patients, suggesting that miR-155 might be involved in blood glucose control and diabetes. Gain-of-function and loss-of-function studies in mice demonstrate that miR-155 has no effects on the pancreatic β-cell proliferation and function. Global transgenic overexpression of miR-155 in mice leads to hypoglycaemia, improved glucose tolerance and insulin sensitivity. Conversely, miR-155 deficiency in mice causes hyperglycemia, impaired glucose tolerance and insulin resistance. In addition, consistent with a positive regulatory role of miR-155 in glucose metabolism, miR-155 positively modulates glucose uptake in all cell types examined, while mice overexpressing miR-155 transgene show enhanced glycolysis, and insulin-stimulated AKT and IRS-1 phosphorylation in liver, adipose tissue or skeletal muscle. Furthermore, we reveal these aforementioned phenomena occur, at least partially, through miR-155-mediated repression of important negative regulators (i.e. C/EBPβ, HDAC4 and SOCS1) of insulin signaling. Taken together, these findings demonstrate, for the first time, that miR-155 is a positive regulator of insulin sensitivity with potential applications for diabetes treatment.</p></div