The use of autologous sural nerve grafts is still the current gold standard for the repair of peripheral nerve injuries with wide substance losses, but with a poor rate of functional recovery after repair of mixed and motor nerves, a limited donor nerve supply, and morbidity of donor site. At present, tubulization through the muscle vein combined graft, is a viable alternative to the nerve autografts and certainly is a matter of tissue engineering still open to continuous development, although this technique is currently limited to a critical gap of 3 cm with less favorable results for motor function recovery. In this report, we present a completely new tubulization method, the amnion muscle combined graft (AMCG) technique, that consists in the combination of the human amniotic membrane hollow conduit with autologous skeletal muscle fragments for repairing the substance loss of peripheral nerves and recover both sensory and motor functions. In a series of five patients with loss of substance of the median nerve ranging 3–5 cm at the wrist, excellent results graded as S4 in two cases, S3+ in two cases, and S3 in one case; M4 in four cases and M3 in one case were achieved. No iatrogenic damage due to withdrawal of a healthy nerve from donor site was observed. This technique allows to repair extensive loss of substance up to 5 cm with a good sensory and motor recovery. The AMCG thus may be considered a reasonable alternative to traditional nerve autograft in selected clinical conditions. © 2014 Wiley Periodicals, Inc. Microsurgery 34:616–622, 2014.
We present a mathematical model describing the auxetic‐austenitic phase transition phenomenon by a second order shape memory phase transition. The typical properties of auxetic materials, as the negative Poisson ratio ν , are described by a function of the phase ϕ , called order parameter, which relates the phase transition with a change of the internal order structure of the material. In our model, the auxetic phase is represented by an order parameter ϕ = 1, which provides a negative Poisson's ratio, while the austenitic phase will be denoted by ϕ = 0. Copyright © 2013 John Wiley & Sons, Ltd.
Few empirical formulae produced to represent the complex dielectric constant in the frequency domain are discussed here from the view point of the possibility of their representation in the time domain. Because a generic function of the frequency does not necessarily admit an inverse Fourier transform, it is not always possible to obtain the corresponding time domain representation of the constant defined in the time frequency. With the use of the fractional derivatives, we introduce a tentative model of the dielectric constant including a linear term, the complex dielectric constant with its loss, and the loss of the direct current electrical conductivity. With appropriate values of the parameters, the system reproduces in the frequency domain the K. Cole and R. Cole model, without the contribution of the loss of the direct current electrical conductivity, which is studied by an autonomous constitutive equation. Copyright © 2014 John Wiley & Sons, Ltd.
Scope Pterostilbene (Pt) is emerging as an important health‐promoting natural compound. Pharmacokinetic studies so far have focused on plasma levels, while Pt distribution in tissues is most relevant for biological action. This study determined tissue distribution of Pt and its major metabolite, pterostilbene‐4′‐sulfate (Pt‐S), in rats after oral administration. Methods and results Upon intravenous (iv) administration (88 μmol/kg), Pt was cleared from blood with a half‐life of 1.8 ± 0.3 h. Oral administration (same dose) resulted in moderate Pt bioavailability (∼35%) and in an increased abundance of Pt‐S in blood (AUC Pt /AUC Pt‐S ∼0.75 and ∼0.05 after iv or oral administration, respectively). Pt‐S was the major species in all organs except the brain, where intact Pt was predominant (AUC Pt /AUC Pt‐S ∼5). Both Pt and Pt‐S peaked in all tissues at approximately 2 h. The highest levels (∼200 nmoles/g for Pt‐S and 40 nmoles/g for Pt) were measured in the liver, the lowest (≤7 nmol/g) in skeletal muscles and testes. Conclusion AUC Pt was ∼2‐ to ∼25‐fold higher in tissues than in blood; this may explain its bioactivity despite barely detectable blood levels. Of particular interest is the high fraction of nonmetabolized Pt in the brain, given the reports of its activity at the level of the central nervous system.
We report numerical and experimental results concerning fully printed loop antennas for WLAN communications based on composite right‐/left‐handed transmission lines. In this work, we describe a different approach and methodology with respect to other omnidirectional loop antennas that have already been presented in the literature. Indeed, we exploit the possibility of using only printed elements for loading the loop, and we show that this solution offers new degrees of freedom for fine tuning of the operating frequency and for a deep optimization of the omnidirectional radiation pattern. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1405–1408, 2014
SUMMARY Cytokines are key regulators of ovarian physiology, particularly in relation to folliculogenesis and ovulation, where they contribute to creating an environment supporting follicle selection and growth. Their manifold functions include regulating cellular proliferation/differentiation, follicular survival/atresia, and oocyte maturation. Several cytokines, such as TGF‐β‐superfamily members, are involved at all stages of folliculogenesis while the production of others is stage‐dependent. This review draws upon evidence from both human and animal models to highlight the species‐specific roles at each milestone of follicular development. Given these pivotal roles and their ease of detection in follicular fluid, cytokines have been considered as attractive biomarkers of oocyte maturational status and of successful assisted reproductive outcome. Despite this, our understanding of cytokines and their interactions remains incomplete, and is still frequently limited to overly simplistic descriptions of their interrelationships. Given our increased appreciation of cytokine activity in complex and highly regulated networks, we put forward the case for using Bayesian modelling approaches to describe their hierarchical relationships in order to predict causal physiological interactions in vivo. Mol. Reprod. Dev . 81: 284–314, 2014. © 2013 Wiley Periodicals, Inc.
SUMMARY Fetal adnexa are a non‐controversial source of mesenchymal stem cells (MSCs) that have high plasticity, a high proliferation rate, and the ability to differentiate towards multiple lineages. MSC populations have been characterized for their stemness and differentiation capabilities; more recent work has focused on MSC selection and on establishing predictable elements to discriminate the cells with the most potential for regenerative medicine. In this study, we cytogenetically and molecularly characterized and followed the in vitro proliferation and differentiation potential of early‐passage canine amniotic membrane MSCs (AM‐MSCs) and umbilical cord matrix MSCs (UCM‐MSCs) isolated from fetuses at early (35–40 days) and late (45–55 days) gestational ages. We found that cells from both fetal gestational ages showed similar features. In all examined cell lines, the morphology of proliferating cells typically appeared fibroblast‐like. Population doublings, passaged up to 10 times, increased significantly with passage number. In both cell types, cell viability and chromosomal number and structure were not affected by gestational age at early passages. Passage‐3 AM‐ and UCM‐MSCs from both gestational phases also expressed embryonic ( POU5F1 ) and mesenchymal ( CD29 , CD44 ) stemness markers, whereas hematopoietic and histocompatibility markers were never found in any sample. Passage‐3 cell populations of each cell type were also multipotential as they could differentiate into neurocytes and osteocytes, based on cell morphology, specific stains, and molecular analysis. These results indicated that MSCs retrieved from the UCM and AM in the early and late fetal phases of gestation could be used for canine regenerative medicine. Mol. Reprod. Dev. 81: 539–551, 2014. © 2014 Wiley Periodicals, Inc .
ABSTRACT Introduction : We describe the innervation zone (IZ) location in 43 muscles to provide information for appropriate positioning of bipolar electrodes for clinical and research applications. Methods : The IZ was studied in 40 subjects (20 men and 20 women) using multichannel surface electromyography (sEMG). Signal quality was checked visually to identify motor unit action potentials and estimate muscle fiber conduction velocity. Results : Results in 33 muscles were classified as excellent or good, because it was possible to identify an area which is favorable for appropriate positioning of an electrode pair without the need to previously determine the IZ location. Conclusions : Knowledge of IZ location will increase standardization and repeatability of sEMG measures. Muscle Nerve 49 :413–421, 2014
: The purpose of this study was to measure and analyze motor unit number estimation (MUNE) values longitudinally in spinal muscular atrophy (SMA). Methods : Sixty‐two children with SMA types 2 and 3 were observed prospectively for up to 42 months. Longitudinal electrophysiological data were collected, including compound motor action potential (CMAP), single motor unit action potential (SMUP), and MUNE. Results : Significant motor neuron loss and compensatory collateral reinnervation were noted at baseline. Over time, there was a significant mean increase in MUNE (4.92 units/year, P = 0.009), a mean decrease in SMUP amplitude (−6.32 μV/year, P = 0.10), and stable CMAP amplitude. Conclusions : The unexpected longitudinal results differ from findings in amyotrophic lateral sclerosis studies, perhaps indicating that compensatory processes in SMA involve new motor unit development. A better understanding of the mechanisms of motor unit decline and compensation in SMA is important for assessing novel therapeutic strategies and for providing key insights into disease pathophysiology. Muscle Nerve 49 : 636–644, 2014