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Abstract The electromagnetic compatibility analysis of RF circuitry is essential due to the adverse effects on sensitive components. Two metamaterial unit cells with slow‐wave properties are presented for cross‐talk reduction in transmission lines. The analytical expressions for computing equivalent lumped elements of the lines are then provided. The dispersion diagram is obtained from the parameters extracted from the measurement. A microstrip as the generator line and five identical CRLH unit cells as the receptor line are then used and a significant reduction in cross‐talk is observed in comparison to conventional lines. A non‐uniform transmission line with two different CRLH unit cells as the receptor line is then employed and found effective in further cross‐talk reduction between the lines. The lengths of the lines and numbers of cells are kept the same in all lines for comparison. The simulated results are validated by measurements.

Abstract Objective ACTN2, encoding alpha‐actinin‐2, is essential for cardiac and skeletal muscle sarcomeric function. ACTN2 variants are a known cause of cardiomyopathy without skeletal muscle involvement. Recently, specific dominant monoallelic variants were reported as a rare cause of core myopathy of variable clinical onset, although the pathomechanism remains to be elucidated. The possibility of a recessively inherited ACTN2‐myopathy has also been proposed in a single series. Methods We provide clinical, imaging, and histological characterization of a series of patients with a novel biallelic ACTN2 variant. Results We report seven patients from five families with a recurring biallelic variant in ACTN2: c.1516A>G (p.Arg506Gly), all manifesting with a consistent phenotype of asymmetric, progressive, proximal, and distal lower extremity predominant muscle weakness. None of the patients have cardiomyopathy or respiratory insufficiency. Notably, all patients report Palestinian ethnicity, suggesting a possible founder ACTN2 variant, which was confirmed through haplotype analysis in two families. Muscle biopsies reveal an underlying myopathic process with disruption of the intermyofibrillar architecture, Type I fiber predominance and atrophy. MRI of the lower extremities demonstrate a distinct pattern of asymmetric muscle involvement with selective involvement of the hamstrings and adductors in the thigh, and anterior tibial group and soleus in the lower leg. Using an in vitro splicing assay, we show that c.1516A>G ACTN2 does not impair normal splicing. Interpretation This series further establishes ACTN2 as a muscle disease gene, now also including variants with a recessive inheritance mode, and expands the clinical spectrum of actinopathies to adult‐onset progressive muscle disease.

Abstract A technique for wireless power transfer (WPT) efficiency improvement by a proper design of the excitation waveform is presented. This improvement is obtained on the one hand by a combined‐harmonics excitation, and on the other hand by exploiting multiple‐resonance coupled resonators. In contrast to wireless communications, there is no constraint on the linearity of the transmitter and receiver in a WPT system. Therefore, the impact of the excitation waveform on the power transfer efficiency with the help of an analytical model is investigated. An optimum excitation waveform is determined to maximise the power transfer efficiency. Thereafter, the authors concentrate on designing a multiple‐resonance coupled resonator system that is consistent with the determined excitation waveform. This work introduces a non‐uniform spiral resonator for controlling the self‐resonant frequencies, which is consistent with the required excitation waveform. The performance of the designed coupled resonators is then evaluated using a 3D finite‐element method and experiments. The numerical simulation and experimental results are in good agreement, verifying the validity of our design.

Abstract Objective FHL1‐related reducing body myopathy is an ultra‐rare, X‐linked dominant myopathy. In this cross‐sectional study, we characterize skeletal muscle ultrasound, muscle MRI, and cardiac MRI findings in FHL1‐related reducing body myopathy patients. Methods Seventeen patients (11 male, mean age 35.4, range 12–76 years) from nine independent families with FHL1‐related reducing body myopathy underwent clinical evaluation, muscle ultrasound (n = 11/17), and lower extremity muscle MRI (n = 14/17), including Dixon MRI (n = 6/17). Muscle ultrasound echogenicity was graded using a modified Heckmatt scale. T1 and STIR axial images of the lower extremity muscles were evaluated for pattern and distribution of abnormalities. Quantitative analysis of intramuscular fat fraction was performed using the Dixon MRI images. Cardiac studies included electrocardiogram (n = 15/17), echocardiogram (n = 17/17), and cardiac MRI (n = 6/17). Cardiac muscle function, T1 maps, T2‐weighted black blood images, and late gadolinium enhancement patterns were analyzed. Results Muscle ultrasound showed a distinct pattern of increased echointensity in skeletal muscles with a nonuniform, multifocal, and “geographical” distribution, selectively involving the deeper fascicles of muscles such as biceps and tibialis anterior. Lower extremity muscle MRI showed relative sparing of gluteus maximus, rectus femoris, gracilis, and lateral gastrocnemius muscles and an asymmetric and multifocal, “geographical” pattern of T1 hyperintensity within affected muscles. Cardiac studies revealed mild and nonspecific abnormalities on electrocardiogram and echocardiogram with unremarkable cardiac MRI studies. Interpretation Skeletal muscle ultrasound and muscle MRI reflect the multifocal aggregate formation in muscle in FHL1‐related reducing body myopathy and are practical and informative tools that can aid in diagnosis and monitoring of disease progression.

Abstract Objective To define the transcriptomic changes responsible for the histologic alterations in skeletal muscle and their progression in collagen VI‐related muscular dystrophy (COL6‐RD). Methods COL6‐RD patient muscle biopsies were stratified into three groups based on the overall level of pathologic severity considering degrees of fibrosis, muscle fiber atrophy, and fatty replacement of muscle tissue. Using microarray and RNA‐Seq, we then performed global gene expression profiling on the same muscle biopsies and compared their transcriptome with age‐ and sex‐matched controls. Results COL6‐RD muscle biopsy transcriptomes as a group revealed prominent upregulation of muscle extracellular matrix component genes and the downregulation of skeletal muscle and mitochondrion‐specific genes. Upregulation of the TGFβ pathway was the most conspicuous change across all biopsies and was fully evident even in the mildest/earliest histological group. There was no difference in the overall transcriptional signature between the different histologic groups but polyserial analysis identified relative changes along with COL6‐RD histological severity. Interpretation Overall, our study establishes the prominent dysregulation of extracellular matrix genes, TGFβ signaling, and its downstream cellular pathways at the transcriptomic level in COL6‐RD muscle.

Abstract Objective To characterize the natural history and clinical features of myopathies caused by mono‐allelic, dominantly acting pathogenic variants in COL12A1. Methods Patients with dominant COL12A1‐related myopathies were characterized by history and clinical examination, muscle imaging, and genetic analysis. Pathogenicity of the variants was assessed by immunostaining patient‐derived dermal fibroblast cultures for collagen XII. Results Four independent families with childhood‐onset weakness due to novel, dominantly acting pathogenic variants in COL12A1 were identified. Adult patients exhibited distal‐predominant weakness. Three families carried dominantly acting glycine missense variants, and one family had a heterozygous, intragenic, in‐frame deletion of exon 52 of COL12A1. All pathogenic variants resulted in increased intracellular retention of collagen XII in patient‐derived fibroblasts as well as loss of extracellular, fibrillar collagen XII deposition. Since haploinsufficiency for COL12A1 is largely clinically asymptomatic, we designed and evaluated small interfering RNAs (siRNAs) that specifically target the mutant allele containing the exon 52 deletion. Immunostaining of the patient fibroblasts treated with the siRNA showed a near complete correction of collagen XII staining patterns. Interpretation This study characterizes a distal myopathy phenotype in adults with dominant COL12A1 pathogenic variants, further defining the phenotypic spectrum and natural history of COL12A1‐related myopathies. This work also provides proof of concept of a precision medicine treatment approach by proposing and validating allele‐specific knockdown using siRNAs specifically designed to target a patient’s dominant COL12A1 disease allele.

Tooth anomalies are rare phenomena that may be reported by patients as chief complaints or may be discovered by dentists in the oral examination. In a few cases, rare anomalies are found together in one mouth. Decision to treat such anomalies depends on whether or not they interfere with function and esthetics and also the patient's preference. In the present case, a 19-year-old male presented with two right maxillary fused central and lateral incisors and a geminated left maxillary central incisor. A talon-like projection was found at the junction site of the fused teeth. His chief complaint was sensitivity to cold at the site of the giant fused tooth. This report describes the process of diagnosis and treatment of the two anomalies according to patient preference and needs.

Objective: Autoantibodies against transcription intermediary factor 1γ (TIF1γ) are found in many patients with dermatomyositis (DM). Although TIF1γ is known to play a role in the differentiation of other tissues, its functional role in muscle regeneration has not been elucidated. This study was undertaken to explore the regulation and functional role of this protein during muscle differentiation and regeneration., Methods: TIF1γ expression was analyzed in human muscle biopsy specimens using immunofluorescence microscopy. Immunofluorescence microscopy and immunoblotting analyses were used to study TIF1γ expression in a mouse model of muscle injury and repair. The effect of premature TIF1γ silencing on muscle differentiation was studied in cultured mouse myoblasts., Results: In muscle biopsy specimens from DM patients, TIF1γ was expressed at low levels in the nuclei of histologically normal muscle cells but at high levels in the centralized nuclei of atrophic, perifascicular myofibers expressing markers of regeneration. TIF1γ levels were also increased in regenerating myonuclei following muscle injury in mice. Premature silencing of TIF1γ in vitro using small interfering RNA did not accelerate the expression of myogenin, a transcription factor that plays a central role in regulating relatively early stages of muscle differentiation. However, premature silencing of TIF1γ did accelerate myotube fusion and the expression of myosin heavy chain (MyHC), a later marker of muscle differentiation., Conclusion: The DM autoantigen TIF1γ is markedly up-regulated during muscle regeneration in human and mouse muscle cells. Premature silencing of this protein in cultured myoblasts accelerates MyHC expression and myoblast fusion. However, TIF1γ may function independently of, or downstream from, myogenin., (© 2015 The Authors. Arthritis & Rheumatology is published by Wiley Periodicals, Inc. on behalf of the American College of Rheumatology.)