BACKGROUND Numerous studies have found that patients experiencing sudden sensorineural hearing loss(SSHL),with or without accompanying vertigo,often show impaired vestibular function.However,there is a dearth of studi...BACKGROUND Numerous studies have found that patients experiencing sudden sensorineural hearing loss(SSHL),with or without accompanying vertigo,often show impaired vestibular function.However,there is a dearth of studies analyzing vestibularevoked myogenic potentials(VEMPs)in SSHL patients across various age groups.AIM To investigate vestibular condition in SSHL patients across various age demographics.METHODS Clinical data of 84 SSHL patients were investigated retrospectively.Audiometry,cervical vestibular evoked myogenic potentials(c-VEMPs),and ocular vestibular evoked myogenic potentials(o-VEMPs)were conducted on these patients.Parameters assessed included the latencies of P1 and N1 waves,as well as the amplitudes of P1–N1 waves.Moreover,the study evaluated the influence of factors such as sex,affected side,configuration of hearing loss,and presence of accompanying vertigo.RESULTS Among the 84 SSHL patients,no significant differences were observed among the three groups in terms of gender,affected side,and the presence or absence of vertigo.Group II(aged 41–60 years)had the highest number of SSHL cases.The rates of absent o-VEMPs in the affected ears were 20.83%,31.58%,and 22.72%for the three age groups,respectively,with no statistically significant difference among them.The rates of absent c-VEMPs in the affected ears were 8.3%,34.21%,and 18.18%for the three age groups,respectively,with significant differences.In the unaffected ears,there were differences observed in the extraction rates of o-VEMPs in the unaffected ears among the age groups.In the three age groups,no significant differences were noted in the three age groups in the latencies of P1 and N1 waves or in the amplitude of N1–P1 waves for c-VEMPs and o-VEMPs,either on the affected side or on the unaffected side,across the three age groups.CONCLUSION The extraction rate of VEMPs is more valuable than parameters.Regardless of the presence of vertigo,vestibular organs are involved in SSHL.Notably,SSHL patients aged 41–60 appear more susceptible to damage to the inferior vestibular nerve and saccule.展开更多
Purpose: This review article provides the readers with an in-depth insight in understanding and interpreting various research literatures on the masseter vestibular evoked myogenic potentials(mVEMP). The article also ...Purpose: This review article provides the readers with an in-depth insight in understanding and interpreting various research literatures on the masseter vestibular evoked myogenic potentials(mVEMP). The article also reviews the contemporary researches involving the clinical applications of the mVEMP. Conclusions: Masseter VEMP is an evolving yet clinically promising neuro-otology test tool that has recently gained more research interest and is considered an additional tool to diagnose various vestibular disorders. Masseter VEMP assesses the functional integrity of the acoustic-masseteric and vestibulo-masseteric reflex pathways. The mVEMP could be used as a complementary test to evaluate the same peripheral generator as the cervical VEMP but a different central pathway i.e., vestibulo-trigeminal pathway. Various research studies that have experimented on parameters such as the effect of different electrode montages(zygomatic vs mandibular configurations), stimulation rates, filter settings and stimuli used to evoke mVEMP have been discussed in this article that could assist in the optimization of a comprehensive clinical protocol. The latency and the amplitude of mVEMP waveforms serve as significant parameters in differentiating normals from those of the clinical populations. Along with the cVEMPs and oVEMPs, mVEMP might help diagnose brainstem lesions in REM Sleep behaviour disorders, Multiple Sclerosis and Parkinson's disease. However, further studies are required to probe in this area of research.展开更多
Objective:To investigate the effects of conductive hearing loss (CHL) on vestibular evoked myogenic potentials (VEMPs) using a simulated CHL model, and to provide the basis for future studies. Methods:Twenty-one healt...Objective:To investigate the effects of conductive hearing loss (CHL) on vestibular evoked myogenic potentials (VEMPs) using a simulated CHL model, and to provide the basis for future studies. Methods:Twenty-one healthy subjects were recruited in this study. We measured ocular VEMPs (oVEMPs) and cervical VEMPs (cVEMPs) in these subjects by air-conduction sound (ACS) stimulation. CHL was simulated later by blocking the right external auditory canal with a soundproof earplug to evaluate its impacts on VEMPs. Subjects' responses before simulated CHL served as the control, and were compared to their responses following simulated CHL. Results: oVEMPs following simulated CHL showed decreased response rate, elevated thresholds, attenuated amplitudes and prolonged N1 latencies compared with those before simulated CHL, and the differences were statistically significant. Similarly, cVEMPs following simulated CHL also showed decreased response rate, elevated thresholds and attenuated amplitudes, with prolonged P1 latencies compared with those before simulated CHL, although only differences in response rate, threshold and amplitude were significant. Conclusions:Conductive hearing loss affects the response rate and other response parameters in oVEMPs and cVEMPs.展开更多
Objective:To report detection of vestibular-evoked myogenic potentials (VEMPs) in the miniature pig. Methods:Potentials evoked by 1000 Hz tone bursts were recorded from neck extensor muscles and the masseter muscles i...Objective:To report detection of vestibular-evoked myogenic potentials (VEMPs) in the miniature pig. Methods:Potentials evoked by 1000 Hz tone bursts were recorded from neck extensor muscles and the masseter muscles in normal adult Bama miniature pigs anesthetized with 3%pentobarbital sodium and Carbachol II. Results:The latency of the first positive wave P from neck extensor muscles was 7.65 ± 0.64 ms, with an amplitude of 1.66 ± 0.34 uv and a rate of successful induction of 75%at 80 dB SPL. The latency of potentials evoked from the masseter muscles was 7.60 ± 0.78 ms, with an amplitude of 1.31 ± 0.28 uv and a rate successful induction of 66%at 80 dB SPL. Conclusion:The latencies and thresholds of VEMPs recorded from the neck extensor muscle and the masseter muscle appear to be comparable in normal adult Bama miniature pigs, although the amplitude recorded from the neck extensor muscle seems to be higher than that from the masseter muscle. However, because of their usually relatively superficial and easily accessible location, as well as their large volume and strong contractions, masseter muscles may be better target muscles for recording myogenic potentials.展开更多
Adipose-derived stem cells have been shown to promote peripheral nerve regeneration through the paracrine secretion of neurotrophic factors. However, it is unclear whether these cells can promote myogenic differentiat...Adipose-derived stem cells have been shown to promote peripheral nerve regeneration through the paracrine secretion of neurotrophic factors. However, it is unclear whether these cells can promote myogenic differentiation in muscular dystrophy. Adipose-derived stem cells （6 × 106） were injected into the gastrocnemius muscle of mdx mice at various sites. Dystrophin expression was found in the muscle fibers. Phosphorylation levels of Akt, mammalian target of rapamycin （mTOR）, eIF-4E binding protein 1 and $6 kinase 1 were increased, and the Akt/mTOR pathway was activated. Simultaneously, myogenin levels were increased, whereas cleaved caspase 3 and vimentin levels were decreased. Necrosis and fibrosis were reduced in the muscle fibers. These findings suggest that adipose-derived stem cells promote the re- generation and survival of muscle cells by inhibiting apoptosis and fibrosis, thereby alleviating muscle damage in muscular dystrophy.展开更多
Objectives: The aim of our study is to examine vestibular-evoked myogenic potentials(VEMPs) elicited by the galvanic vestibular stimulation in the sternocleidomastoid muscle(SCM) in healthy subjects for clinical appli...Objectives: The aim of our study is to examine vestibular-evoked myogenic potentials(VEMPs) elicited by the galvanic vestibular stimulation in the sternocleidomastoid muscle(SCM) in healthy subjects for clinical applications of auditory neuropathy or vestibular neuropathy in the future.Methods: We enrolled sixteen healthy subjects to record the average responses of SCM to galvanic vestibular stimulation(GVS) [current 3 mA;duration 1 ms] by electromyography(EMG). SPSS 18.0 software was used to analyze the obtained data for mean and standard deviation.Results: In all healthy subjects mastoid-forehead galvanic vestibular stimulation produced a positive-negative biphasic EMG responses on SCM ipsilateral to the cathodal electrode. The latency of p13 was 11.7 ± 3.0 ms. The latency of n23 was 17.8 ± 3.4 ms. The amplitude of p13-n23 was147.0 ± 69.0 μV. The interaural asymmetry ratio(AR) of p13, n23 latency and the amplitude was respectively 0.12 ± 0.09, 0.08 ± 0.08 and0.16 ± 0.10.Discussions: Galvanic vestibular stimulation could elicit biphasic EMG responses from SCM via the vestibular nerve but not from the otolith organs. Galvanic stimulation together with air conducted sound(ACS) or bone conducted vibration(BCV) can elicit VEMPs and may enable the differentiation of retrolabyrinthine lesions from labyrinthine lesions in vestibular system.展开更多
Objective:To report vestibular evoked myogenic potentials from different recording sites(neck extensor or masseter muscles) in miniature pigs and rats.Methods:Potentials were recorded using 1000 Hz tone bursts from th...Objective:To report vestibular evoked myogenic potentials from different recording sites(neck extensor or masseter muscles) in miniature pigs and rats.Methods:Potentials were recorded using 1000 Hz tone bursts from the neck extensor muscle or masseter muscle in normal adult Bama miniature pigs and rats anesthetized with 3%pentobarbital sodium and Sumianxin Ⅱ.Results:At 80 dB SPL,the first positive wave(P wave) of VEMPs was recognizable in 58%of rats with a latency of 6.45±0.23 ms and an amplitude of 1.45±0.49 μV when recorded from the neck extensor muscle,and in 50%of rats with a latency of 6.38±0.34 ms and an amplitude of 1.57±0.35 μV when recorded from the masseter muscle.In miniature pigs,at the same stimulus intensity,P wave was recognizable in 58%of the animals with a latency of 7.65±0.64 ms and an amplitude of 1.66±0.34 μV when recorded from the neck extensor muscle,and in 50%of the animals with a latency of 7.65±0.64 ms and an amplitude of 0.31±0.28 μV when recorded from the masseter muscle.Conclusion:VEMP can be induced from both neck extensor and masseter muscles in the miniature pig and rat.For a given species,the site of recording affects P wave induction rate and amplitude but not latency.Consistency and repeatability analysis suggests that the masseter muscle is a better recording site in miniature pigs while the cervical extensor is a better recording site in rats.For a given recording site,both latency and amplitude of the P wave are slightly greater in miniature pigs than in rats.展开更多
Although the exact mechanism and most involved region of the vestibular system have not yet been fully clarified, vestibular dysfunction has been demonstrated in patients with diabetes mellitus (DM). Vestibular evoked...Although the exact mechanism and most involved region of the vestibular system have not yet been fully clarified, vestibular dysfunction has been demonstrated in patients with diabetes mellitus (DM). Vestibular evoked myogenic potential (VEMP) is a short latency electromyographic response to sound or vibration stimuli that may reflect otolith organ or related reflex functions. Since its first description in 1992, VEMP has become a significant part of the vestibular test battery as an objective measurement tool. In diabetic patients, VEMP responses have been studied in order to determine any otolith organ or related reflex dysfunctions. Here, we review the literature with regard to VEMP findings representing any peripheral vestibular end-organ dysfunction in patients with DM. Distinctive vestibular end-organ impairments seem to be demonstrated in patients with DM either with or without DNP via objective vestibular testing tools including VEMP recordings according to relevant studies. However, further studies with larger sample sizes are required to reveal the more definitive findings of VEMP recordings regarding the vestibular pathologies in patients with DM.展开更多
MyoD, Myf5, and myogenin are myogenic regulatory factors that play important roles during myogenesis. It is thought that MyoD and Myf5 are required for myogenic determination, while myogenin is important for terminal ...MyoD, Myf5, and myogenin are myogenic regulatory factors that play important roles during myogenesis. It is thought that MyoD and Myf5 are required for myogenic determination, while myogenin is important for terminal differentiation and lineage maintenance. To better understand the function of myogenic regulatory factors in muscle development of flounder, an important economic fish in Asia, real-time quantitative RT-PCR was used to characterize the expression patterns of MyoD, Myf5, and myogenin at early stages of embryo development, and in different tissues of the adult flounder. The results show that, MyJ5 is the first gene to be expressed during the early stages of flounder development, followed by MyoD and myogenin. The expressions ofMyf5, MyoD, and myogenin at the early stages have a common characteristic： expression gradually increased to a peak level, and then gradually decreased to an extremely low level. In the adult flounder, the expression of the three genes in muscle is much higher than that in other tissues, indicating that they are important for muscle growth and maintenance of grown fish. During embryonic stages, the expression level of MyoD might serve an important role in the balance between muscle cell differentiation and proliferation. When the MyoD expression is over 30% of its highest level, the muscle cells enter the differentiation stage.展开更多
Background:Cytosolic Ca^(2+)plays vital roles in myogenesis and muscle development.As a major Ca^(2+)release channel of endoplasmic reticulum(ER),ryanodine receptor 1(RyR1)key mutations are main causes of severe conge...Background:Cytosolic Ca^(2+)plays vital roles in myogenesis and muscle development.As a major Ca^(2+)release channel of endoplasmic reticulum(ER),ryanodine receptor 1(RyR1)key mutations are main causes of severe congenital myopathies.The role of RyR1 in myogenic differentiation has attracted intense research interest but remains unclear.Results:In the present study,both RyR1-knockdown myoblasts and CRISPR/Cas9-based RyR1-knockout myoblasts were employed to explore the role of RyR1 in myogenic differentiation,myotube formation as well as the potential mechanism of RyR1-related myopathies.We observed that RyR1 expression was dramatically increased during the late stage of myogenic differentiation,accompanied by significantly elevated cytoplasmic Ca^(2+)concentration.Inhibition of RyR1 by siRNA-mediated knockdown or chemical inhibitor,dantrolene,significantly reduced cytosolic Ca^(2+)and blocked multinucleated myotube formation.The elevation of cytoplasmic Ca^(2+)concentration can effectively relieve myogenic differentiation stagnation by RyR1 inhibition,demonstrating that RyR1 modulates myogenic differentiation via regulation of Ca^(2+)release channel.However,RyR1-knockout-induced Ca^(2+)leakage led to the severe ER stress and excessive unfolded protein response,and drove myoblasts into apoptosis.Conclusions:Therefore,we concluded that Ca^(2+)release mediated by dramatic increase in RyR1 expression is required for the late stage of myogenic differentiation and fusion.This study contributes to a novel understanding of the role of RyR1 in myogenic differentiation and related congenital myopathies,and provides a potential target for regulation of muscle characteristics and meat quality.展开更多
Introduction:The masseter vestibular evoked myogenic potential(mVEMP)is a bilaterally generated,electromyographically(EMG)-mediated response innervated by the trigeminal nerve.The purpose of the present investigation ...Introduction:The masseter vestibular evoked myogenic potential(mVEMP)is a bilaterally generated,electromyographically(EMG)-mediated response innervated by the trigeminal nerve.The purpose of the present investigation was to 1)determine whether subjects could accurately achieve and maintain a range of EMG target levels,2)to examine the effects of varied EMG levels on the latencies and amplitudes of the mVEMP,and 3)to investigate the degree of side-to-side asymmetry and any effects of EMG activation.Methods:Subjects were nine neurologically and otologically normal young adults.A high-intensity tone burst was presented monaurally while subjects were seated upright and asked to match a range of EMG target levels by clenching their teeth.Recordings were made from the ipsilateral and contralateral masseter muscles referenced to the ear being monaurally stimulated.Results:We found that the tonic EMG target had no effect on mVEMP latency.Additionally,although mVEMP amplitudes“scaled”to the EMG target,there was a tendency for the subjects’EMG level to“undershoot”the EMG target levels greater than 50 mV.While some individuals did generate differences in EMG activation between sides,there were no significant differences on average EMG activation between sides.Further,while average corrected amplitude asymmetry was similar across EMG targets,some individuals demonstrated large,corrected amplitude asymmetry ratios.Conclusions:The results of this investigation suggest that,as with cVEMP recordings,the underlying EMG activation may vary between subjects and could impact mVEMP amplitudes,yet could be mitigated by amplitude correction techniques.Further it is important to be aware that even young normal subjects have difficulty maintaining large,tonic EMG activity during the mVEMP recording.展开更多
Vestibular evoked myogenic potential （VEMP）, is an electromyographic response of vestibular origin evoked by sound, vibration or electrical stimulation. VEMP is widely used as a clinical test of the otolith organs. ...Vestibular evoked myogenic potential （VEMP）, is an electromyographic response of vestibular origin evoked by sound, vibration or electrical stimulation. VEMP is widely used as a clinical test of the otolith organs. Now-adays, two kinds of VEMP, cervical VEMP （cVEMP） and ocular VEMP （oVEMP） are clinically used. cVEMP is a test of sacculo-collic refex while oVEMP is a test of utri-culo-ocular refex. Absence of responses, large interau-ral asymmetry of amplitudes, prolonged peak latencies, and abnormal thresholds of responses are regarded as abnormal responses. Clinical application to various diseases of the vestibular system was performed. Using VEMP, a new type of vestibular neuritis, inferior ves-tibular neuritis was established. A prominent feature of VEMP in Meniere’s disease is a shift of a preferred fre-quency in cVEMP. The whole aspects of VEMP fndings in patients with benign paroxysmal positional vertigo are not clarifed yet. Sensitivity of cVEMP to vestibular schwannoma was 80.0%, while specifcity was 52.7%. Concerning diagnosis of superior canal dehiscence syn-drome （SCDS）, oVEMP to air-conducted sound is the most helpful. Augmentation of oVEMP responses is a prominent feature in SCDS. I also presented “idiopathic otolithic vertigo”, which I proposed as a new clinical en-tity based on VEMP fndings. Some patients complained of lateral tilting sensation in the roll plane, or tilting or translational sensation in the pitch plane without rota-tory vertigo. Majority of patients with these symptoms had absent or decreased responses of oVEMP and/or cVEMP. I proposed that these patients could be diag-nosed as having “idiopathic otolithic vertigo”.展开更多
Background： The growth rate often varies among individual broilers of the same breed under a common management condition. To investigate whether a variation in the growth rate is associated with a difference in hormo...Background： The growth rate often varies among individual broilers of the same breed under a common management condition. To investigate whether a variation in the growth rate is associated with a difference in hormone levels and myogenic gene expression profile in broilers, a feeding trial was conducted with 10,000 newly hatched Ross 308 chicks in a commercial production facility under standard management. At 38 d of age,30 fast-, 30 medium-, and 30 slow-growing broilers were selected among 600 healthy male individuals. The levels of insulin-like growth factor-1（IGF-1）, triiodothyronine（T3）, thyroxine（T4）, and growth hormone in the serum or breast muscle were assayed by ELISA or RIA kits, and the expression levels of several representative pro-and anti-myogenic genes in the breast muscle were also measured by real-time PCR.Results： Results showed that both absolute and relative weights of the breast muscle were in linear positive correlations with the body weight of broilers（P 〈 0.001）. Fast-growing broilers had higher concentrations of IGF-1 than slow-growing broilers（P 〈 0.05） in both the serum and breast muscle. The serum concentration of T3 was significantly higher in fast-growing birds than in slow-growing birds（P 〈 0.05）. However, no difference was observed in growth hormone or T4 concentration among three groups of birds. Additionally, a decreased expression of an anti-myogenic gene（myostatin） and increased expressions of pro-myogenic genes such as myogenic differentiation factor 1, myogenin, muscle regulatory factor 4, myogenic factor 5, IGF-1, and myocyte enhancer factor 2B, C, and D were observed in fast-growing broilers（P 〈 0.05）, relative to slow-growing broilers.Conclusions： Collectively, these findings suggested that the growth rate is linked to the hormone and myogenic gene expression levels in broiler chickens. Some of these parameters such as serum concentrations of IGF-1 and T3 could be employed to breed for enhanced growth.展开更多
Skeletal muscle regeneration mainly depends on muscle satellite cells;however,these cells are not sufficient for supporting repair and regeneration in volumetric muscle loss(VML),Duchenne muscular dystrophy,and other ...Skeletal muscle regeneration mainly depends on muscle satellite cells;however,these cells are not sufficient for supporting repair and regeneration in volumetric muscle loss(VML),Duchenne muscular dystrophy,and other muscle injuries or muscle diseases.As such,much work has been conducted in recent years to search for myogenic stem cells.Adipose-derived stem cells(ADSCs)have a wide range of sources,rapid growth,and multi-directional differentiation potential,and have become vital candidates for muscle regeneration.Multiple factors influence the myogenic differentiation capacity of ADSCs.This paper reviews the regulatory aspects and possible factors that have been identified in recent years to affect myogenic differentiation of ADSCs.Based on these factors,gene editing,and perfusion concepts,a method was proposed to achieve maximal differentiation efficiency of ADSCs.This study focused on the application of ADSCs in muscle regeneration and disease.Based on the importance of myogenic differentiation of ADSCs for the repair and regeneration of muscle damage,this study provides a basis for future research surrounding the efficient induction of myogenic differentiation of ADSCs in vitro.展开更多
Objective Auditory neuropathy(AN)is a unique pattern of hearing loss with preservation of hair cell function.The condition is characterized by the presence of otoacoustic emissions(OAE)or cochlear microphonic(CM)respo...Objective Auditory neuropathy(AN)is a unique pattern of hearing loss with preservation of hair cell function.The condition is characterized by the presence of otoacoustic emissions(OAE)or cochlear microphonic(CM)responses with severe abnormalities of the auditory brainstem response(ABR).The vestibular branches of the VIII cranial nerve and the structures innervated by it can also be affected.However,the precise lesion sites in the vestibular system are not well characterized in patients with AN.Methods The air-conducted sound(ACS)vestibular-evoked myogenic potentials(VEMPs)and galvanic vestibular stimuli(GVS)-VEMPs were examined in 14 patients with AN.Results On examination of VEMPs(n=14,28 ears),the absent rates of ACS-cervical VEMP(cVEMP),ACS-ocular VEMP(oVEMP),GVS-cVEMP,GVS-oVEMP and caloric test were 92.9%(26/28),85.7%(24/28),67.9%(19/28),53.6%(15/28),and 61.5%(8/13),respectively.Impaired functions of the saccule,inferior vestibular nerve,utricle,superior vestibular nerve,and horizontal semicircular canal were found in 25.0%(7/28),67.9%(19/28),32.1%(9/28),53.6%(15/28)and 61.5%(8/13)patients,respectively.On comparing the elicited VEMPs parameters of AN patients with those of normal controls,both ACS-VEMPs and GVS-VEMPs showed abnormal results in AN patients(such as,lower presence rates,elevated thresholds,prolonged latencies,and decreased amplitudes).Conclusion The study suggested that patients with AN often have concomitant vestibular disorders.Retro-labyrinthine lesions were more frequently observed in this study.GVS-VEMPs combined with ACS-VEMPs may help identify the lesion sites and facilitate detection of areas of vestibular dysfunction in these patients.展开更多
As one member of winged helix domain transcription factors, FoxD5 was reported to be a trunk organizer. Recent study showed that zebrafish foxd5 is expressed in the somites. To further understand the function of FoxD5...As one member of winged helix domain transcription factors, FoxD5 was reported to be a trunk organizer. Recent study showed that zebrafish foxd5 is expressed in the somites. To further understand the function of FoxD5 in fish muscle development, the FoxD5 gene was isolated from flounder. Its expression pattern was analyzed by in situ hybridization, while its function in regulating myogenic regulatory factor, MyoD, was analyzed by ectopic expression. It showed that flounder FoxD5 was firstly expressed in the tailbud, adaxial cells, and neural plate of the head. In flounder embryo, FoxD5 is expressed not only in forebrain but also in somite cells that will form muscle in the future. When flounder FoxD5 was over-expressed in zebrafish by microinjection, the expression of zebrafish MyoD in the somites was reduced, suggesting that FoxD5 is involved in myogenesis by regulating the expression of MyoD.展开更多
[ Objective] The mechanism of antiseptic cream myogenic was revealed from the angle of cytokines to provide theoretical basis for clini- cal application. [ Method] Experiment with Wistar rats were studied, by detectin...[ Objective] The mechanism of antiseptic cream myogenic was revealed from the angle of cytokines to provide theoretical basis for clini- cal application. [ Method] Experiment with Wistar rats were studied, by detecting indicators such as the expression level of VEGF and bFGFmRNA of skin coloboma model rats wound tissue. [ Result] The results showed that： Antiseptic cream myogenic can improve VEGF and bFGFmRNA levels of the wound tissue,[Conclusion] Antiseptic cream myogenic can promote the proliferation and differentiation of vascular endothelial call and fibro- blast, and thus promote wound healing.展开更多
The purpose of this study is 1) to present a biomechanical model for evaluating the myogenic power expended in an arterial segment due to vascular smooth muscle contraction (VSMC) and 2) to assess the total power expe...The purpose of this study is 1) to present a biomechanical model for evaluating the myogenic power expended in an arterial segment due to vascular smooth muscle contraction (VSMC) and 2) to assess the total power expenditure in the entire systemic arterial tree by utilizing the fractal nature of the branching architecture. The model is based on the mechanical equilibrium between the stretch stress exerted by blood pressure inside the vessel lumen and constricting stress elicited by VSMC in the vascular wall. An expression for myogenic power expenditure is formulated for a unit wall mass as a function of the internal vessel radius and extent of strain. This expression was then integrated over selected range of vessel radii, by taking into account of the fractal nature of the branching structure. When the total myogenic power expended in the systemic arterial tree in rat at the moderate strain level is converted to the oxygen consumption rate, it amounts to approximately 18% of the whole body oxygen consumption rate. This suggests that the mechanical power expenditure due to VSMC is a significant factor that should not be ignored in studies of vascular energetics.展开更多
Two commonly used growth promotants in the United States beef industry are <em>β</em>-agonists and anabolic steroid hormones. Each has been shown to increase lean muscle deposition in cattle provided trea...Two commonly used growth promotants in the United States beef industry are <em>β</em>-agonists and anabolic steroid hormones. Each has been shown to increase lean muscle deposition in cattle provided treatments of each growth technology, but much is still unknown of how steroidal implants and <em>β</em>-agonists work in combination. It was our goal to determine the effect of implant strategy and <em>β</em>-agonist administration in beef feedlot heifers (n = 264). A 3 × 2 factorial randomized complete block design was used with 2 levels of OPT and 3 different durations of terminal implant (TI) windows for a total of 6 treatment groups with 9 replications. Terminal implants (20 mg estradiol/200 mg trenbolone acetate implant, Component TE-200) were provided to heifers 140 d from slaughter (TI140), 100 d from slaughter (TI100), or 60 d from slaughter (TI60). Animals receiving the later two TI being first implanted on day 0 (8 mg estradiol/80 mg trenbolone acetate implant, Component TE-IH). The second treatment of the cattle received was the orally active beta adrenergic agonist, ractopamine-hydrochloride (RH) in the form of Optaflexx<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">®</span>(OPT;0 (NO) or 200 (YES) mg/hd<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>d<sup>-1</sup>) over the final 28 days of the trial. Thirty animals were subjected to longissimus muscle (LM) biopsies on d 0, 40, 80, 112, and at slaughter on d 140 to view mRNA levels of myogenic related genes and protein quantities of the <em>β</em>1-adrenergic receptor (<em>β</em>1 AR) and <em>β</em>2-adrenergic receptor (<em>β</em>2 AR). On the same days, blood samples were taken from 108 animals to assess changes in plasma blood urea nitrogen (BUN), non-esterified fatty acids (NEFA) and progesterone due to treatments. Relative mRNA levels of myosin heavy chain IIX (MHC IIX), AMPKα, and IGF-I were increased (<em>P</em> < 0.05) in animals receiving a TI100 over the other two implant dates after OPT was fed to animals. After OPT administration myosin heavy chain IIA (MHC IIA) mRNA levels tended to decrease (<em>P</em> = 0.09) due to OPT. An interaction between TI d and OPT administration caused an increase (<em>P</em> < 0.05) in MHC IIA mRNA level in the TI60/Yes treatment group over all other treatments except the TI100/No treatment group. Protein intensity of the <em>β</em>2 AR was decreased (<em>P</em> < 0.05) by the latest TI d (TI60) during OPT feeding, while<em> β</em>1 AR protein intensity tended to be lower (<em>P</em> < 0.10) in animals fed OPT. Plasma BUN levels were reduced (<em>P</em> < 0.05) after terminal implants and OPT feeding;while progesterone was decreased (<em>P</em> < 0.05) by OPT alone. Neither growth promotant affected NEFA levels in plasma. Collectively, these data indicate that ractopamine hydrochloride and estradiol + trenbolone acetate implants alter myogenic mRNA, <em>β</em>-adrenergic receptors, and blood metabolites in finishing beef heifers.展开更多
BACKGROUND Healthy vestibular system adjusts balance during static and dynamic conditions.This is important for normal development(standing up and walking).Vestipulopathies(central and peripheral)are common complicati...BACKGROUND Healthy vestibular system adjusts balance during static and dynamic conditions.This is important for normal development(standing up and walking).Vestipulopathies(central and peripheral)are common complications of diabetes in adult population.Related studies are scare in children with type 1 diabetes(T1D).AIM To assess saccular function of otolith organ in children with T1D and predictors for its dysfunction.METHODS Cervical vestibular evoked myogenic potential(cVEMP)was used for objective evaluation.RESULTS The study included 40 patients(boys=15;girls=25).Patients had mean age of 13.63±1.50 years,duration of diabetes of 5.62±2.80 years,frequent attacks of diabetic ketoacidosis(55%)and hypoglycemia(30%),hyperlipidemia(20%),hypertension(12.5%)and peripheral neuropathy(40%).Dizziness was found in 10%.Compared to healthy children(n=25),patients had prolonged cVEMP P1 and N1 latencies and reduced P1-N1 amplitude.Bilateral cVEMP abnormalities were found in 60%(vs 25%for unilateral abnormalities).Higher frequencies and severe vestibulopathies were found with chronic diabetes of>5 years,hemoglobin A1c values>7%,frequent diabetic ketoacidosis and hypoglycemic attacks and presence of dizziness.Regression analyses showed that predictors for prolonged P1 latencies and reduced P1-N1 amplitudes were only chronic diabetes(>5 years){odds ratio(OR)=2.80[95%confidence interval(CI):1.80–5.33],P=0.01;OR=3.42(95%CI:2.82–6.81)}and its severity(hemoglobin A1c>7%)[OR=3.05(95%CI:2.55–6.82),P=0.01;OR=4.20(95%CI:3.55–8.50),P=0.001].CONCLUSION Dysfunction or injury of the saccular macula and its pathways is prevalent in children with T1D.Optimum glycemic control is important to prevent diabetes related vestipulopathies.展开更多
基金the Innovative Program of Hebei Provincial Eye Hospital,No.2023ZZ107.
文摘BACKGROUND Numerous studies have found that patients experiencing sudden sensorineural hearing loss(SSHL),with or without accompanying vertigo,often show impaired vestibular function.However,there is a dearth of studies analyzing vestibularevoked myogenic potentials(VEMPs)in SSHL patients across various age groups.AIM To investigate vestibular condition in SSHL patients across various age demographics.METHODS Clinical data of 84 SSHL patients were investigated retrospectively.Audiometry,cervical vestibular evoked myogenic potentials(c-VEMPs),and ocular vestibular evoked myogenic potentials(o-VEMPs)were conducted on these patients.Parameters assessed included the latencies of P1 and N1 waves,as well as the amplitudes of P1–N1 waves.Moreover,the study evaluated the influence of factors such as sex,affected side,configuration of hearing loss,and presence of accompanying vertigo.RESULTS Among the 84 SSHL patients,no significant differences were observed among the three groups in terms of gender,affected side,and the presence or absence of vertigo.Group II(aged 41–60 years)had the highest number of SSHL cases.The rates of absent o-VEMPs in the affected ears were 20.83%,31.58%,and 22.72%for the three age groups,respectively,with no statistically significant difference among them.The rates of absent c-VEMPs in the affected ears were 8.3%,34.21%,and 18.18%for the three age groups,respectively,with significant differences.In the unaffected ears,there were differences observed in the extraction rates of o-VEMPs in the unaffected ears among the age groups.In the three age groups,no significant differences were noted in the three age groups in the latencies of P1 and N1 waves or in the amplitude of N1–P1 waves for c-VEMPs and o-VEMPs,either on the affected side or on the unaffected side,across the three age groups.CONCLUSION The extraction rate of VEMPs is more valuable than parameters.Regardless of the presence of vertigo,vestibular organs are involved in SSHL.Notably,SSHL patients aged 41–60 appear more susceptible to damage to the inferior vestibular nerve and saccule.
文摘Purpose: This review article provides the readers with an in-depth insight in understanding and interpreting various research literatures on the masseter vestibular evoked myogenic potentials(mVEMP). The article also reviews the contemporary researches involving the clinical applications of the mVEMP. Conclusions: Masseter VEMP is an evolving yet clinically promising neuro-otology test tool that has recently gained more research interest and is considered an additional tool to diagnose various vestibular disorders. Masseter VEMP assesses the functional integrity of the acoustic-masseteric and vestibulo-masseteric reflex pathways. The mVEMP could be used as a complementary test to evaluate the same peripheral generator as the cervical VEMP but a different central pathway i.e., vestibulo-trigeminal pathway. Various research studies that have experimented on parameters such as the effect of different electrode montages(zygomatic vs mandibular configurations), stimulation rates, filter settings and stimuli used to evoke mVEMP have been discussed in this article that could assist in the optimization of a comprehensive clinical protocol. The latency and the amplitude of mVEMP waveforms serve as significant parameters in differentiating normals from those of the clinical populations. Along with the cVEMPs and oVEMPs, mVEMP might help diagnose brainstem lesions in REM Sleep behaviour disorders, Multiple Sclerosis and Parkinson's disease. However, further studies are required to probe in this area of research.
基金supported by grants from the National Natural Science Foundation of China, China (No. 81670945, 81541040)Fundamental Research Funds for the Central Universities, China (No. 2012jdhz13)+1 种基金Shaanxi Major International Cooperative Project, China (No. 2013KW-28)Key Science and Technology Program of Xi'an, China (No. SF1315(1))
文摘Objective:To investigate the effects of conductive hearing loss (CHL) on vestibular evoked myogenic potentials (VEMPs) using a simulated CHL model, and to provide the basis for future studies. Methods:Twenty-one healthy subjects were recruited in this study. We measured ocular VEMPs (oVEMPs) and cervical VEMPs (cVEMPs) in these subjects by air-conduction sound (ACS) stimulation. CHL was simulated later by blocking the right external auditory canal with a soundproof earplug to evaluate its impacts on VEMPs. Subjects' responses before simulated CHL served as the control, and were compared to their responses following simulated CHL. Results: oVEMPs following simulated CHL showed decreased response rate, elevated thresholds, attenuated amplitudes and prolonged N1 latencies compared with those before simulated CHL, and the differences were statistically significant. Similarly, cVEMPs following simulated CHL also showed decreased response rate, elevated thresholds and attenuated amplitudes, with prolonged P1 latencies compared with those before simulated CHL, although only differences in response rate, threshold and amplitude were significant. Conclusions:Conductive hearing loss affects the response rate and other response parameters in oVEMPs and cVEMPs.
基金supported by grants from the National Basic Research Program of China (973 Program) (#2012CB967900)National Natural Science Foundation of China (31300624, 81470684)+3 种基金Postdoctoral Science Foundation of China(2015M571818)Six Major Categories Talent (2014-WSN043, 2011-WS-074)Innovation and Entrepreneurship Training Program for College Students in Jiangsu Province (201510313003Z, 201510313003, KYLX14-1455)Clinic Medical Special Foundation Of Jiangsu Province (b12014032)
文摘Objective:To report detection of vestibular-evoked myogenic potentials (VEMPs) in the miniature pig. Methods:Potentials evoked by 1000 Hz tone bursts were recorded from neck extensor muscles and the masseter muscles in normal adult Bama miniature pigs anesthetized with 3%pentobarbital sodium and Carbachol II. Results:The latency of the first positive wave P from neck extensor muscles was 7.65 ± 0.64 ms, with an amplitude of 1.66 ± 0.34 uv and a rate of successful induction of 75%at 80 dB SPL. The latency of potentials evoked from the masseter muscles was 7.60 ± 0.78 ms, with an amplitude of 1.31 ± 0.28 uv and a rate successful induction of 66%at 80 dB SPL. Conclusion:The latencies and thresholds of VEMPs recorded from the neck extensor muscle and the masseter muscle appear to be comparable in normal adult Bama miniature pigs, although the amplitude recorded from the neck extensor muscle seems to be higher than that from the masseter muscle. However, because of their usually relatively superficial and easily accessible location, as well as their large volume and strong contractions, masseter muscles may be better target muscles for recording myogenic potentials.
基金supported by the National Natural Science Foundation of China,No.30370510,30870851,81271401the Joint Fund of National Natural Science Foundation of ChinaNatural Science Foundation of Guangdong Province of China,No.U1032004
文摘Adipose-derived stem cells have been shown to promote peripheral nerve regeneration through the paracrine secretion of neurotrophic factors. However, it is unclear whether these cells can promote myogenic differentiation in muscular dystrophy. Adipose-derived stem cells （6 × 106） were injected into the gastrocnemius muscle of mdx mice at various sites. Dystrophin expression was found in the muscle fibers. Phosphorylation levels of Akt, mammalian target of rapamycin （mTOR）, eIF-4E binding protein 1 and $6 kinase 1 were increased, and the Akt/mTOR pathway was activated. Simultaneously, myogenin levels were increased, whereas cleaved caspase 3 and vimentin levels were decreased. Necrosis and fibrosis were reduced in the muscle fibers. These findings suggest that adipose-derived stem cells promote the re- generation and survival of muscle cells by inhibiting apoptosis and fibrosis, thereby alleviating muscle damage in muscular dystrophy.
基金supported by Japan China Sasakawa Medical Fellowship 2016(YL)
文摘Objectives: The aim of our study is to examine vestibular-evoked myogenic potentials(VEMPs) elicited by the galvanic vestibular stimulation in the sternocleidomastoid muscle(SCM) in healthy subjects for clinical applications of auditory neuropathy or vestibular neuropathy in the future.Methods: We enrolled sixteen healthy subjects to record the average responses of SCM to galvanic vestibular stimulation(GVS) [current 3 mA;duration 1 ms] by electromyography(EMG). SPSS 18.0 software was used to analyze the obtained data for mean and standard deviation.Results: In all healthy subjects mastoid-forehead galvanic vestibular stimulation produced a positive-negative biphasic EMG responses on SCM ipsilateral to the cathodal electrode. The latency of p13 was 11.7 ± 3.0 ms. The latency of n23 was 17.8 ± 3.4 ms. The amplitude of p13-n23 was147.0 ± 69.0 μV. The interaural asymmetry ratio(AR) of p13, n23 latency and the amplitude was respectively 0.12 ± 0.09, 0.08 ± 0.08 and0.16 ± 0.10.Discussions: Galvanic vestibular stimulation could elicit biphasic EMG responses from SCM via the vestibular nerve but not from the otolith organs. Galvanic stimulation together with air conducted sound(ACS) or bone conducted vibration(BCV) can elicit VEMPs and may enable the differentiation of retrolabyrinthine lesions from labyrinthine lesions in vestibular system.
基金supported by grants from the National Basic Research Program of China (973 Program)(#2012CB967900)National Natural Science Foundation of China (31300624,81470684)+3 种基金Postdoctoral Science Foundation of China (2015M571818)Six Major Categories of Talent (2014-WSN043,2011-WS-074)Innovation and Entrepreneurship Training Program for College Students in Jiangsu Province(201510313003Z,201510313003,KYLX14-1455)Clinic Medical Special Foundation of Jiangsu Province (b12014032)
文摘Objective:To report vestibular evoked myogenic potentials from different recording sites(neck extensor or masseter muscles) in miniature pigs and rats.Methods:Potentials were recorded using 1000 Hz tone bursts from the neck extensor muscle or masseter muscle in normal adult Bama miniature pigs and rats anesthetized with 3%pentobarbital sodium and Sumianxin Ⅱ.Results:At 80 dB SPL,the first positive wave(P wave) of VEMPs was recognizable in 58%of rats with a latency of 6.45±0.23 ms and an amplitude of 1.45±0.49 μV when recorded from the neck extensor muscle,and in 50%of rats with a latency of 6.38±0.34 ms and an amplitude of 1.57±0.35 μV when recorded from the masseter muscle.In miniature pigs,at the same stimulus intensity,P wave was recognizable in 58%of the animals with a latency of 7.65±0.64 ms and an amplitude of 1.66±0.34 μV when recorded from the neck extensor muscle,and in 50%of the animals with a latency of 7.65±0.64 ms and an amplitude of 0.31±0.28 μV when recorded from the masseter muscle.Conclusion:VEMP can be induced from both neck extensor and masseter muscles in the miniature pig and rat.For a given species,the site of recording affects P wave induction rate and amplitude but not latency.Consistency and repeatability analysis suggests that the masseter muscle is a better recording site in miniature pigs while the cervical extensor is a better recording site in rats.For a given recording site,both latency and amplitude of the P wave are slightly greater in miniature pigs than in rats.
文摘Although the exact mechanism and most involved region of the vestibular system have not yet been fully clarified, vestibular dysfunction has been demonstrated in patients with diabetes mellitus (DM). Vestibular evoked myogenic potential (VEMP) is a short latency electromyographic response to sound or vibration stimuli that may reflect otolith organ or related reflex functions. Since its first description in 1992, VEMP has become a significant part of the vestibular test battery as an objective measurement tool. In diabetic patients, VEMP responses have been studied in order to determine any otolith organ or related reflex dysfunctions. Here, we review the literature with regard to VEMP findings representing any peripheral vestibular end-organ dysfunction in patients with DM. Distinctive vestibular end-organ impairments seem to be demonstrated in patients with DM either with or without DNP via objective vestibular testing tools including VEMP recordings according to relevant studies. However, further studies with larger sample sizes are required to reveal the more definitive findings of VEMP recordings regarding the vestibular pathologies in patients with DM.
基金Supported by the Key Laboratory of Experimental Marine Biology,Academia Sinica,Qingdao,Chinathe National High Technology Research and Development Program of China(863 Program)(No.2006AA10AA402)+1 种基金the National Basic Research Program of China(973Program)(Nos.2004CB117402,2010CB126304)the National Natural Science Foundation of China(No.30871929)
文摘MyoD, Myf5, and myogenin are myogenic regulatory factors that play important roles during myogenesis. It is thought that MyoD and Myf5 are required for myogenic determination, while myogenin is important for terminal differentiation and lineage maintenance. To better understand the function of myogenic regulatory factors in muscle development of flounder, an important economic fish in Asia, real-time quantitative RT-PCR was used to characterize the expression patterns of MyoD, Myf5, and myogenin at early stages of embryo development, and in different tissues of the adult flounder. The results show that, MyJ5 is the first gene to be expressed during the early stages of flounder development, followed by MyoD and myogenin. The expressions ofMyf5, MyoD, and myogenin at the early stages have a common characteristic： expression gradually increased to a peak level, and then gradually decreased to an extremely low level. In the adult flounder, the expression of the three genes in muscle is much higher than that in other tissues, indicating that they are important for muscle growth and maintenance of grown fish. During embryonic stages, the expression level of MyoD might serve an important role in the balance between muscle cell differentiation and proliferation. When the MyoD expression is over 30% of its highest level, the muscle cells enter the differentiation stage.
基金financially supported by the National Natural Science Foundation of China (Grant No. 31790412)National key research and development program of China (Grant No. 2018YFD0500402)the National Natural Science Foundation of China (Grant No. 31672431)
文摘Background:Cytosolic Ca^(2+)plays vital roles in myogenesis and muscle development.As a major Ca^(2+)release channel of endoplasmic reticulum(ER),ryanodine receptor 1(RyR1)key mutations are main causes of severe congenital myopathies.The role of RyR1 in myogenic differentiation has attracted intense research interest but remains unclear.Results:In the present study,both RyR1-knockdown myoblasts and CRISPR/Cas9-based RyR1-knockout myoblasts were employed to explore the role of RyR1 in myogenic differentiation,myotube formation as well as the potential mechanism of RyR1-related myopathies.We observed that RyR1 expression was dramatically increased during the late stage of myogenic differentiation,accompanied by significantly elevated cytoplasmic Ca^(2+)concentration.Inhibition of RyR1 by siRNA-mediated knockdown or chemical inhibitor,dantrolene,significantly reduced cytosolic Ca^(2+)and blocked multinucleated myotube formation.The elevation of cytoplasmic Ca^(2+)concentration can effectively relieve myogenic differentiation stagnation by RyR1 inhibition,demonstrating that RyR1 modulates myogenic differentiation via regulation of Ca^(2+)release channel.However,RyR1-knockout-induced Ca^(2+)leakage led to the severe ER stress and excessive unfolded protein response,and drove myoblasts into apoptosis.Conclusions:Therefore,we concluded that Ca^(2+)release mediated by dramatic increase in RyR1 expression is required for the late stage of myogenic differentiation and fusion.This study contributes to a novel understanding of the role of RyR1 in myogenic differentiation and related congenital myopathies,and provides a potential target for regulation of muscle characteristics and meat quality.
文摘Introduction:The masseter vestibular evoked myogenic potential(mVEMP)is a bilaterally generated,electromyographically(EMG)-mediated response innervated by the trigeminal nerve.The purpose of the present investigation was to 1)determine whether subjects could accurately achieve and maintain a range of EMG target levels,2)to examine the effects of varied EMG levels on the latencies and amplitudes of the mVEMP,and 3)to investigate the degree of side-to-side asymmetry and any effects of EMG activation.Methods:Subjects were nine neurologically and otologically normal young adults.A high-intensity tone burst was presented monaurally while subjects were seated upright and asked to match a range of EMG target levels by clenching their teeth.Recordings were made from the ipsilateral and contralateral masseter muscles referenced to the ear being monaurally stimulated.Results:We found that the tonic EMG target had no effect on mVEMP latency.Additionally,although mVEMP amplitudes“scaled”to the EMG target,there was a tendency for the subjects’EMG level to“undershoot”the EMG target levels greater than 50 mV.While some individuals did generate differences in EMG activation between sides,there were no significant differences on average EMG activation between sides.Further,while average corrected amplitude asymmetry was similar across EMG targets,some individuals demonstrated large,corrected amplitude asymmetry ratios.Conclusions:The results of this investigation suggest that,as with cVEMP recordings,the underlying EMG activation may vary between subjects and could impact mVEMP amplitudes,yet could be mitigated by amplitude correction techniques.Further it is important to be aware that even young normal subjects have difficulty maintaining large,tonic EMG activity during the mVEMP recording.
文摘Vestibular evoked myogenic potential （VEMP）, is an electromyographic response of vestibular origin evoked by sound, vibration or electrical stimulation. VEMP is widely used as a clinical test of the otolith organs. Now-adays, two kinds of VEMP, cervical VEMP （cVEMP） and ocular VEMP （oVEMP） are clinically used. cVEMP is a test of sacculo-collic refex while oVEMP is a test of utri-culo-ocular refex. Absence of responses, large interau-ral asymmetry of amplitudes, prolonged peak latencies, and abnormal thresholds of responses are regarded as abnormal responses. Clinical application to various diseases of the vestibular system was performed. Using VEMP, a new type of vestibular neuritis, inferior ves-tibular neuritis was established. A prominent feature of VEMP in Meniere’s disease is a shift of a preferred fre-quency in cVEMP. The whole aspects of VEMP fndings in patients with benign paroxysmal positional vertigo are not clarifed yet. Sensitivity of cVEMP to vestibular schwannoma was 80.0%, while specifcity was 52.7%. Concerning diagnosis of superior canal dehiscence syn-drome （SCDS）, oVEMP to air-conducted sound is the most helpful. Augmentation of oVEMP responses is a prominent feature in SCDS. I also presented “idiopathic otolithic vertigo”, which I proposed as a new clinical en-tity based on VEMP fndings. Some patients complained of lateral tilting sensation in the roll plane, or tilting or translational sensation in the pitch plane without rota-tory vertigo. Majority of patients with these symptoms had absent or decreased responses of oVEMP and/or cVEMP. I proposed that these patients could be diag-nosed as having “idiopathic otolithic vertigo”.
基金supported by the Special Fund for Public Projects of Zhejiang Province(2016C32073)International Cooperation Program of Zhejiang Academy of Agricultural Sciences
文摘Background： The growth rate often varies among individual broilers of the same breed under a common management condition. To investigate whether a variation in the growth rate is associated with a difference in hormone levels and myogenic gene expression profile in broilers, a feeding trial was conducted with 10,000 newly hatched Ross 308 chicks in a commercial production facility under standard management. At 38 d of age,30 fast-, 30 medium-, and 30 slow-growing broilers were selected among 600 healthy male individuals. The levels of insulin-like growth factor-1（IGF-1）, triiodothyronine（T3）, thyroxine（T4）, and growth hormone in the serum or breast muscle were assayed by ELISA or RIA kits, and the expression levels of several representative pro-and anti-myogenic genes in the breast muscle were also measured by real-time PCR.Results： Results showed that both absolute and relative weights of the breast muscle were in linear positive correlations with the body weight of broilers（P 〈 0.001）. Fast-growing broilers had higher concentrations of IGF-1 than slow-growing broilers（P 〈 0.05） in both the serum and breast muscle. The serum concentration of T3 was significantly higher in fast-growing birds than in slow-growing birds（P 〈 0.05）. However, no difference was observed in growth hormone or T4 concentration among three groups of birds. Additionally, a decreased expression of an anti-myogenic gene（myostatin） and increased expressions of pro-myogenic genes such as myogenic differentiation factor 1, myogenin, muscle regulatory factor 4, myogenic factor 5, IGF-1, and myocyte enhancer factor 2B, C, and D were observed in fast-growing broilers（P 〈 0.05）, relative to slow-growing broilers.Conclusions： Collectively, these findings suggested that the growth rate is linked to the hormone and myogenic gene expression levels in broiler chickens. Some of these parameters such as serum concentrations of IGF-1 and T3 could be employed to breed for enhanced growth.
基金supported by the National Nature Science Foundation of China(grant nos.81873939 and 31970374)the Scientific Research Staring Foundation for the Returned Overseas Chinese Scholars of Peking University Third Hospital(grant no.BYSYLXHG2019001).
文摘Skeletal muscle regeneration mainly depends on muscle satellite cells;however,these cells are not sufficient for supporting repair and regeneration in volumetric muscle loss(VML),Duchenne muscular dystrophy,and other muscle injuries or muscle diseases.As such,much work has been conducted in recent years to search for myogenic stem cells.Adipose-derived stem cells(ADSCs)have a wide range of sources,rapid growth,and multi-directional differentiation potential,and have become vital candidates for muscle regeneration.Multiple factors influence the myogenic differentiation capacity of ADSCs.This paper reviews the regulatory aspects and possible factors that have been identified in recent years to affect myogenic differentiation of ADSCs.Based on these factors,gene editing,and perfusion concepts,a method was proposed to achieve maximal differentiation efficiency of ADSCs.This study focused on the application of ADSCs in muscle regeneration and disease.Based on the importance of myogenic differentiation of ADSCs for the repair and regeneration of muscle damage,this study provides a basis for future research surrounding the efficient induction of myogenic differentiation of ADSCs in vitro.
基金supported by grants from the National Natural Science Foundation of China(No.81670945,No.81970891,No.81600809,No.81700915)the Shaanxi Major International Cooperative Project of China(No.2020KWZ-019)the Key R&D Projects in Shaanxi Province,China(No.2018SF-189).
文摘Objective Auditory neuropathy(AN)is a unique pattern of hearing loss with preservation of hair cell function.The condition is characterized by the presence of otoacoustic emissions(OAE)or cochlear microphonic(CM)responses with severe abnormalities of the auditory brainstem response(ABR).The vestibular branches of the VIII cranial nerve and the structures innervated by it can also be affected.However,the precise lesion sites in the vestibular system are not well characterized in patients with AN.Methods The air-conducted sound(ACS)vestibular-evoked myogenic potentials(VEMPs)and galvanic vestibular stimuli(GVS)-VEMPs were examined in 14 patients with AN.Results On examination of VEMPs(n=14,28 ears),the absent rates of ACS-cervical VEMP(cVEMP),ACS-ocular VEMP(oVEMP),GVS-cVEMP,GVS-oVEMP and caloric test were 92.9%(26/28),85.7%(24/28),67.9%(19/28),53.6%(15/28),and 61.5%(8/13),respectively.Impaired functions of the saccule,inferior vestibular nerve,utricle,superior vestibular nerve,and horizontal semicircular canal were found in 25.0%(7/28),67.9%(19/28),32.1%(9/28),53.6%(15/28)and 61.5%(8/13)patients,respectively.On comparing the elicited VEMPs parameters of AN patients with those of normal controls,both ACS-VEMPs and GVS-VEMPs showed abnormal results in AN patients(such as,lower presence rates,elevated thresholds,prolonged latencies,and decreased amplitudes).Conclusion The study suggested that patients with AN often have concomitant vestibular disorders.Retro-labyrinthine lesions were more frequently observed in this study.GVS-VEMPs combined with ACS-VEMPs may help identify the lesion sites and facilitate detection of areas of vestibular dysfunction in these patients.
基金Supported by the Natural Science Foundation of Shandong Province,China(No.Y2008E12)the National Basic Research Program of China(973Program)(No.2010CB126304)
文摘As one member of winged helix domain transcription factors, FoxD5 was reported to be a trunk organizer. Recent study showed that zebrafish foxd5 is expressed in the somites. To further understand the function of FoxD5 in fish muscle development, the FoxD5 gene was isolated from flounder. Its expression pattern was analyzed by in situ hybridization, while its function in regulating myogenic regulatory factor, MyoD, was analyzed by ectopic expression. It showed that flounder FoxD5 was firstly expressed in the tailbud, adaxial cells, and neural plate of the head. In flounder embryo, FoxD5 is expressed not only in forebrain but also in somite cells that will form muscle in the future. When flounder FoxD5 was over-expressed in zebrafish by microinjection, the expression of zebrafish MyoD in the somites was reduced, suggesting that FoxD5 is involved in myogenesis by regulating the expression of MyoD.
基金funded by the Northeast Agricultural University Talent Fund
文摘[ Objective] The mechanism of antiseptic cream myogenic was revealed from the angle of cytokines to provide theoretical basis for clini- cal application. [ Method] Experiment with Wistar rats were studied, by detecting indicators such as the expression level of VEGF and bFGFmRNA of skin coloboma model rats wound tissue. [ Result] The results showed that： Antiseptic cream myogenic can improve VEGF and bFGFmRNA levels of the wound tissue,[Conclusion] Antiseptic cream myogenic can promote the proliferation and differentiation of vascular endothelial call and fibro- blast, and thus promote wound healing.
文摘The purpose of this study is 1) to present a biomechanical model for evaluating the myogenic power expended in an arterial segment due to vascular smooth muscle contraction (VSMC) and 2) to assess the total power expenditure in the entire systemic arterial tree by utilizing the fractal nature of the branching architecture. The model is based on the mechanical equilibrium between the stretch stress exerted by blood pressure inside the vessel lumen and constricting stress elicited by VSMC in the vascular wall. An expression for myogenic power expenditure is formulated for a unit wall mass as a function of the internal vessel radius and extent of strain. This expression was then integrated over selected range of vessel radii, by taking into account of the fractal nature of the branching structure. When the total myogenic power expended in the systemic arterial tree in rat at the moderate strain level is converted to the oxygen consumption rate, it amounts to approximately 18% of the whole body oxygen consumption rate. This suggests that the mechanical power expenditure due to VSMC is a significant factor that should not be ignored in studies of vascular energetics.
文摘Two commonly used growth promotants in the United States beef industry are <em>β</em>-agonists and anabolic steroid hormones. Each has been shown to increase lean muscle deposition in cattle provided treatments of each growth technology, but much is still unknown of how steroidal implants and <em>β</em>-agonists work in combination. It was our goal to determine the effect of implant strategy and <em>β</em>-agonist administration in beef feedlot heifers (n = 264). A 3 × 2 factorial randomized complete block design was used with 2 levels of OPT and 3 different durations of terminal implant (TI) windows for a total of 6 treatment groups with 9 replications. Terminal implants (20 mg estradiol/200 mg trenbolone acetate implant, Component TE-200) were provided to heifers 140 d from slaughter (TI140), 100 d from slaughter (TI100), or 60 d from slaughter (TI60). Animals receiving the later two TI being first implanted on day 0 (8 mg estradiol/80 mg trenbolone acetate implant, Component TE-IH). The second treatment of the cattle received was the orally active beta adrenergic agonist, ractopamine-hydrochloride (RH) in the form of Optaflexx<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">®</span>(OPT;0 (NO) or 200 (YES) mg/hd<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">·</span>d<sup>-1</sup>) over the final 28 days of the trial. Thirty animals were subjected to longissimus muscle (LM) biopsies on d 0, 40, 80, 112, and at slaughter on d 140 to view mRNA levels of myogenic related genes and protein quantities of the <em>β</em>1-adrenergic receptor (<em>β</em>1 AR) and <em>β</em>2-adrenergic receptor (<em>β</em>2 AR). On the same days, blood samples were taken from 108 animals to assess changes in plasma blood urea nitrogen (BUN), non-esterified fatty acids (NEFA) and progesterone due to treatments. Relative mRNA levels of myosin heavy chain IIX (MHC IIX), AMPKα, and IGF-I were increased (<em>P</em> < 0.05) in animals receiving a TI100 over the other two implant dates after OPT was fed to animals. After OPT administration myosin heavy chain IIA (MHC IIA) mRNA levels tended to decrease (<em>P</em> = 0.09) due to OPT. An interaction between TI d and OPT administration caused an increase (<em>P</em> < 0.05) in MHC IIA mRNA level in the TI60/Yes treatment group over all other treatments except the TI100/No treatment group. Protein intensity of the <em>β</em>2 AR was decreased (<em>P</em> < 0.05) by the latest TI d (TI60) during OPT feeding, while<em> β</em>1 AR protein intensity tended to be lower (<em>P</em> < 0.10) in animals fed OPT. Plasma BUN levels were reduced (<em>P</em> < 0.05) after terminal implants and OPT feeding;while progesterone was decreased (<em>P</em> < 0.05) by OPT alone. Neither growth promotant affected NEFA levels in plasma. Collectively, these data indicate that ractopamine hydrochloride and estradiol + trenbolone acetate implants alter myogenic mRNA, <em>β</em>-adrenergic receptors, and blood metabolites in finishing beef heifers.
文摘BACKGROUND Healthy vestibular system adjusts balance during static and dynamic conditions.This is important for normal development(standing up and walking).Vestipulopathies(central and peripheral)are common complications of diabetes in adult population.Related studies are scare in children with type 1 diabetes(T1D).AIM To assess saccular function of otolith organ in children with T1D and predictors for its dysfunction.METHODS Cervical vestibular evoked myogenic potential(cVEMP)was used for objective evaluation.RESULTS The study included 40 patients(boys=15;girls=25).Patients had mean age of 13.63±1.50 years,duration of diabetes of 5.62±2.80 years,frequent attacks of diabetic ketoacidosis(55%)and hypoglycemia(30%),hyperlipidemia(20%),hypertension(12.5%)and peripheral neuropathy(40%).Dizziness was found in 10%.Compared to healthy children(n=25),patients had prolonged cVEMP P1 and N1 latencies and reduced P1-N1 amplitude.Bilateral cVEMP abnormalities were found in 60%(vs 25%for unilateral abnormalities).Higher frequencies and severe vestibulopathies were found with chronic diabetes of>5 years,hemoglobin A1c values>7%,frequent diabetic ketoacidosis and hypoglycemic attacks and presence of dizziness.Regression analyses showed that predictors for prolonged P1 latencies and reduced P1-N1 amplitudes were only chronic diabetes(>5 years){odds ratio(OR)=2.80[95%confidence interval(CI):1.80–5.33],P=0.01;OR=3.42(95%CI:2.82–6.81)}and its severity(hemoglobin A1c>7%)[OR=3.05(95%CI:2.55–6.82),P=0.01;OR=4.20(95%CI:3.55–8.50),P=0.001].CONCLUSION Dysfunction or injury of the saccular macula and its pathways is prevalent in children with T1D.Optimum glycemic control is important to prevent diabetes related vestipulopathies.
