Modified Antia-Buch repair for full-thickness upper pole auricular defects

Various reconstructive techniques have been described for repair of full-thickness upper pole auricular defects. The wedge excision commonly used for treatment of upper pole tumors allows excision and reconstruction in a single stage. However, this technique suffers from major deficiencies. We apply the concept of crescentic scaphal excision and the Antia-Buch advancement-rotation flap principle to repair various full-thickness upper pole auricular defects resulting from excision of skin lesions in eight consecutive patients. The technique achieves a natural auricular shape in three dimensions with minimal disruption of the anatomic landmarks and avoids conspicuous scars. It has several advantages over the original Antia-Buch repair and other techniques used for reconstruction of full-thickness upper pole auricular defects.     

Changes in orientation of actin during contraction of muscle

It is well documented that muscle contraction results from cyclic rotations of actin-bound myosin cross-bridges. The role of actin is hypothesized to be limited to accelerating phosphate release from myosin and to serving as a rigid substrate for cross-bridge rotations. To test this hypothesis, we have measured actin rotations during contraction of a skeletal muscle. Actin filaments of rabbit psoas fiber were labeled with rhodamine-phalloidin. Muscle contraction was induced by a pulse of ATP photogenerated from caged precursor. ATP induced a single turnover of cross-bridges. The rotations were measured by anisotropy of fluorescence originating from a small volume defined by a narrow aperture of a confocal microscope. The anisotropy of phalloidin-actin changed rapidly at first and was followed by a slow relaxation to a steady-state value. The kinetics of orientation changes of actin and myosin were the same. Extracting myosin abolished anisotropy changes. To test whether the rotation of actin was imposed by cross-bridges or whether it reflected hydrolytic activity of actin itself, we labeled actin with fluorescent ADP. The time-course of anisotropy change of fluorescent nucleotide was similar to that of phalloidin-actin. These results suggest that orientation changes of actin are caused by dissociation and rebinding of myosin cross-bridges, and that during contraction, nucleotide does not dissociate from actin.     

A single muscle's multifunctional control potential of body dynamics for postural control and running

A neuromechanical approach to control requires understanding how mechanics alters the potential of neural feedback to control body dynamics. Here, we rewrite activation of individual motor units of a behaving animal to mimic the effects of neural feedback without concomitant changes in other muscles. We target a putative control muscle in the cockroach, Blaberus discoidalis (L.), and simultaneously capture limb and body dynamics through high-speed videography and a micro-accelerometer backpack. We test four neuromechanical control hypotheses. We supported the hypothesis that mechanics linearly translates neural feedback into accelerations and rotations during static postural control. However, during running, the same neural feedback produced a nonlinear acceleration control potential restricted to the vertical plane. Using this, we reject the hypothesis from previous work that this muscle acts primarily to absorb energy from the body. The conversion of the control potential is paralleled by nonlinear changes in limb kinematics, supporting the hypothesis that significant mechanical feedback filters the graded neural feedback for running control. Finally, we insert the same neural feedback signal but at different phases in the dynamics. In this context, mechanical feedback enables turning by changing the timing and direction of the accelerations produced by the graded neural feedback.     

Effect of auricular electroacupuncture on the motor manifestations of nociceptive reactions

The effect of low frequency auricular electroacupuncture (EAP) on electromyographic responses (EMGR) of the anterior belly of the digastruc muscle, elicited by stimulation of tooth pulp was studied in cat experiments. It was shown that observed augmentation of the EMGR amplitude produced by EAP depended on tonic activation of gamma-motoneurons of the muscle. This activation directly correlated with EAP intensity. At the same time the latent period of EMGR increased by one-two synapses on account of inhibiting shorter pathways in the afferent part of the reflex arch with intensive EAP. The inhibition of EAP-induced augmentation of EMGR can be achieved by administration of small doses of barbiturates that potentiate the analgetic action of EAP.     

Changes in the ovarian structure and fertility of the rat after various ovarian neurectomies

The changes undergone by the ovary 30 days after different unilateral neurectomies were investigated in 45 rats. Fertility modification was observed in a second group of 40 rats that, after the same neurectomies, were placed with a male for a period of 20 days. The only significant change in the ovarian sympathectomized rats was a decrease in the nuclear area of the luteal cells. In the rats with an additional ovariectomy a significant compensatory hypertrophy appeared in the luteal cells. Vagotomy provoked a significant nuclear hypertrophy in the interstitial and luteal cells, as well as in the corpora lutea. In the cases with contralateral ovariectomy this hypertrophy was considerably reduced. Section of the pelvic splanchnic nerve only produced a decrease of the nuclear size in the luteal cells. Subsequent contralateral ovariectomy was followed by an additional atrophy of the luteal cells and corpora lutea. These results indicate that the parasympathetic system, in normal conditions, plays an inhibitory role, while the sympathetic has a light stimulatory effect, principally on the luteal cells. In relation to fertility, 50% of the neurectomized rats, 75% of the control ones and 100% of the neurectomized and contralaterally ovariectomized rats were found pregnant. The average of the embryos implanted in the uterine horn of the neurectomized ovary was significantly smaller than in the control side. On the contrary, in the ovariectomized rats, especially in the case of sympathectomy, the average of the embryos implanted in the uterine horn of the ovariectomized side was significantly higher than in the control animals.     

Growth Factor Stimulation Improves the Structure and Properties of Scaffold-Free Engineered Auricular Cartilage Constructs

The reconstruction of the external ear to correct congenital deformities or repair following trauma remains a significant challenge in reconstructive surgery. Previously, we have developed a novel approach to create scaffold-free, tissue engineering elastic cartilage constructs directly from a small population of donor cells. Although the developed constructs appeared to adopt the structural appearance of native auricular cartilage, the constructs displayed limited expression and poor localization of elastin. In the present study, the effect of growth factor supplementation (insulin, IGF-1, or TGF-β1) was investigated to stimulate elastogenesis as well as to improve overall tissue formation. Using rabbit auricular chondrocytes, bioreactor-cultivated constructs supplemented with either insulin or IGF-1 displayed increased deposition of cartilaginous ECM, improved mechanical properties, and thicknesses comparable to native auricular cartilage after 4 weeks of growth. Similarly, growth factor supplementation resulted in increased expression and improved localization of elastin, primarily restricted within the cartilaginous region of the tissue construct. Additional studies were conducted to determine whether scaffold-free engineered auricular cartilage constructs could be developed in the 3D shape of the external ear. Isolated auricular chondrocytes were grown in rapid-prototyped tissue culture molds with additional insulin or IGF-1 supplementation during bioreactor cultivation. Using this approach, the developed tissue constructs were flexible and had a 3D shape in very good agreement to the culture mold (average error <400 µm). While scaffold-free, engineered auricular cartilage constructs can be created with both the appropriate tissue structure and 3D shape of the external ear, future studies will be aimed assessing potential changes in construct shape and properties after subcutaneous implantation.     

耳后头皮推进瓣急诊即刻修复创伤性耳郭部分缺损的临床效果观察

目的:探讨耳后头皮瓣急诊即刻修复耳郭部分缺损的可行性与临床效果。方法:对2013年1-12月来我院急诊的7例外伤后耳郭部分缺损的患者(均为男性,年龄22-50岁;其中右耳4例,左耳3例)采用耳后头皮推进瓣即刻修复,以耳郭缺损耳后皮肤及头皮皮肤做推进瓣,将断离的耳郭去皮保留软骨与耳郭断端软骨缝合形成软骨支架,推进皮瓣部分卷曲缝合形成耳轮结构修复耳郭缺损。结果:7例耳郭部分缺损均在急诊环境下即刻修复,耳郭大小和形态满意,颅耳角略变小,随访3~6月耳郭形态稳定。结论:耳后头皮推进瓣卷曲缝合可在急诊条件下即刻修复耳郭部分缺损,具有治疗周期短,一次达到较满意外形的优点,对于无条件行二期手术的患者具有较大意义,其远期效果尚有待进一步随访。     

组织透明化三维显示全包埋耳皮肤神经血管网（英文）

目的 结合组织学染色技术和组织透明化策略研究耳部皮肤中神经纤维和血管的空间对应关系。方法 将耳廓前面和后面的皮肤从其中间软骨仔细剥离，然后直接分别用蛋白基因产物9.5 (PGP 9.5)和鬼笔环肽对耳部皮肤的神经纤维和血管进行免疫荧光染色并进行组织透明化处理。随后，以全包埋方式将耳皮肤组织裱贴在载玻片上用于荧光显微镜和共聚焦显微镜观察。结果 本研究显示PGP 9.5阳性神经纤维伴随鬼笔环肽标记的血管一道从耳廓的基部走行到其外围区域形成耳廓的神经血管网。在传统的免疫荧光染色技术基础上，后续的组织透明化技术可以更好地展示耳部皮肤中神经纤维和血管的形态学细节。结论 从方法学的角度来看，组织透明化技术增进了耳部皮肤中免疫荧光标记的可视性，它可能成为有效的技术手段用于解析正常和病理状态下耳部神经血管网的空间结构。     

Abdominal muscle activation changes if the purpose is to control pelvis motion or thorax motion

The aim of this study was to compare trunk muscular recruitment and lumbar spine kinematics when motion was constrained to either the thorax or the pelvis. Nine healthy women performed four upright standing planar movements (rotations, anterior–posterior translations, medial–lateral translations, and horizontal circles) while constraining pelvis motion and moving the thorax or moving the pelvis while minimizing thorax motion, and four isometric trunk exercises (conventional curl-up, reverse curl-up, cross curl-up, and reverse cross curl-up). Surface EMG (upper and lower rectus abdominis, lateral and medial aspects of external oblique, internal oblique, and latissimus dorsi) and 3D lumbar displacements were recorded. Pelvis movements produced higher EMG amplitudes of the oblique abdominals than thorax motions in most trials, and larger lumbar displacements in the medial–lateral translations and horizontal circles. Conversely, thorax movements produced larger rotational lumbar displacement than pelvis motions during rotations and higher EMG amplitudes for latissimus dorsi during rotations and anterior–posterior translations and for lower rectus abdominis during the crossed curl-ups. Thus, different neuromuscular compartments appear when the objective changes from pelvis to thorax motion. This would suggest that both movement patterns should be considered when planning spine stabilization programs, to optimize exercises for the movement and muscle activations desired.     

In Vivo Muscle Electroporation Threshold Determination: Realistic Numerical Models and In Vivo Experiments

In vivo electroporation is used as an effective technique for delivery of therapeutic agents such as chemotherapeutic drugs or DNA into target tissue cells for different biomedical purposes. In order to successfully electroporate a target tissue, it is essential to know the local electric field distribution produced by an application of electroporation voltage pulses. In this study three-dimensional finite element models were built in order to analyze local electric field distribution and corresponding tissue conductivity changes in rat muscle electroporated either transcutaneously or directly (i.e., two-plate electrodes were placed either on the skin or directly on the skeletal muscle after removing the skin). Numerical calculations of electroporation thresholds and conductivity changes in skin and muscle were validated with in vivo measurements. Our model of muscle with skin also confirms the in vivo findings of previous studies that electroporation “breaks” the skin barrier when the applied voltage is above 50?V.     

Effects of postural changes and vestibular lesions on genioglossal muscle activity in conscious cats.

Previous studies in humans showed that genioglossal muscle activity is higher when individuals are supine than when they are upright, and prior experiments in anesthetized or decerebrate animals suggested that vestibular inputs might participate in triggering these alterations in muscle firing. The present study determined the effects of whole body tilts in the pitch (nose-up) plane on genioglossal activity in a conscious feline model and compared these responses with those generated by roll (ear-down) tilts. We also ascertained the effects of a bilateral vestibular neurectomy on the alterations in genioglossal activity elicited by changes in body position. Both pitch and roll body tilts produced modifications in muscle firing that were dependent on the amplitude of the rotation; however, the relative effects of ear-down and nose-up tilts on genioglossal activity were variable from animal to animal. The response variability observed might reflect the fact that genioglossus has a complex organization and participates in a variety of tongue movements; in each animal, electromyographic recordings presumably sampled the firing of different proportions of fibers in the various compartments and subcompartments of the muscle. Furthermore, removal of labyrinthine inputs resulted in alterations in genioglossal responses to postural changes that persisted until recordings were discontinued approximately 1 mo later, demonstrating that the vestibular system participates in regulating the muscle's activity. Peripheral vestibular lesions were subsequently demonstrated to be complete through the postmortem inspection of temporal bone sections or by observing that vestibular nucleus neurons did not respond to rotations in vertical planes.     

Exercise‐stimulated interleukin‐15 is controlled by AMPK and regulates skin metabolism and aging

Aging is commonly associated with a structural deterioration of skin that compromises its barrier function, healing, and susceptibility to disease. Several lines of evidence show that these changes are driven largely by impaired tissue mitochondrial metabolism. While exercise is associated with numerous health benefits, there is no evidence that it affects skin tissue or that endocrine muscle‐to‐skin signaling occurs. We demonstrate that endurance exercise attenuates age‐associated changes to skin in humans and mice and identify exercise‐induced IL‐15 as a novel regulator of mitochondrial function in aging skin. We show that exercise controls IL‐15 expression in part through skeletal muscle AMP‐activated protein kinase (AMPK), a central regulator of metabolism, and that the elimination of muscle AMPK causes a deterioration of skin structure. Finally, we establish that daily IL‐15 therapy mimics some of the anti‐aging effects of exercise on muscle and skin in mice. Thus, we elucidate a mechanism by which exercise confers health benefits to skin and suggest that low‐dose IL‐15 therapy may prove to be a beneficial strategy to attenuate skin aging.     

Isolation, structural characterization, and bioactivity of a novel neuromedin U analog from the defensive skin secretion of the Australasian tree frog, Litoria caerulea

We report the isolation of a novel bioactive peptide, neuromedin U-23 (NmU-23), from the defensive skin secretion of the Australasian tree frog, Litoria caerulea. The primary structure of the peptide was established by a combination of microsequencing, mass spectroscopy and site-directed antiserum immunoreactivity as SDEEVQVPGGVISNGYFLFRPRN-amide (M(r) 2580.6). A synthetic replicate of frog NmU-23 displaced monoradioiodinated rat NmU-23 from uterine membranes in a dose-dependent fashion indistinguishable from nonisotopically labeled rat NmU-23. In a rat uterine smooth muscle strip preparation, synthetic frog NmU-23 produced dose-dependent contractions identical to porcine NmU-25. However, in a preparation of human urinary bladder muscle strip, the synthetic frog peptide was more potent than porcine NmU-25 in eliciting contraction and produced desensitization of the preparation to the latter peptide. This report demonstrates that the defensive skin secretion of a frog contains a novel peptide exhibiting a high degree of primary structural similarity to the endogenous vertebrate peptide, NmU, and that this frog skin analog displays biological activity in mammalian tissues.     

A model of muscular control of upper airway geometry

Some disorders of the upper airway in humans are marked by decreased cross-sectional area and increased airway wall compliance. Based on our observations from studies performed in the isolated upper airway of dogs, we hypothesized that the size, and perhaps the geometry, of the airway was altered by changes in the relative activation levels of various muscle pairs. This could be accomplished either by altering the intensity of the neuromuscular input, or by activating muscle pairs which have different geometric orientation to the airway. We developed an analytic relationship to allow us to vary the stimulus level driving any one of six muscle pairs, each with a different anatomic orientation, to evaluate the relationship between those parameters and upper airway volume. With data generated from bilateral electrical stimulation of upper airway muscles, we described a shape factor which allowed us to predict the maximum force produced at optimal length. These findings were applied to a length/tension curve common to striated muscle to allow us to examine the muscle behavior at lengths other than optimal. The position of each muscle was described in spherical coordinates relative to an elastic cylinder, which represented the isolated, sealed upper airway. These coordinates defined the direction in which the force generated by each muscle pair would be applied. Three compliance constants determined the change in airway dimensions produced by the muscle force. This system and its variables were used to calculate the change in volume of the sealed upper airway chamber resulting from muscle contraction.(ABSTRACT TRUNCATED AT 250 WORDS)     

The extended pectoralis major myocutaneous flap: uses and indications

The vascular territory of the pectoralis major muscle and overlying skin was studied by selective intraarterial dye injections in fresh cadavers. The area of skin overlying the anterior chest and abdominal wall beyond the limits of the pectoralis major muscle that can be elevated as an extended myocutaneous flap was determined. The cadaver injections were evaluated to determine the size and shape of the skin island used to reconstruct defects of the head, neck, and upper trunk with an extended skin paddle off the pectoralis major muscle. Pectoralis muscle flaps with variously shaped skin paddles, some extending beyond the limits of the muscle, were used in 27 patients to cover large soft-tissue defects of the upper thorax, face, and floor of the mouth and as a skin tube to reconstruct the cervical esophagus. The size of the skin paddle ranged from 5 x 7 cm to 26 x 16 cm. All flaps survived completely, and there were no major donor-site complications.     

A pulmonary artery endothelial factor causes unidirectional alignment of smooth muscle cells

Pulmonary artery and aorta endothelial and smooth muscle cells harvested from near term Rambouillet lambs were cultured. To determine whether cultured endothelial cells produce a factor which alters the shape and alignment of smooth muscle cells, rhodamine phalloidin staining of F-actin filaments was carried out, as well as time-lapse cinematography. We were able to demonstrate, with pulmonary artery but not with aortic cells in culture, an endothelial-derived factor which causes the smooth muscle cells to migrate and align in uniform direction. The effect could not be enhanced by making the endothelial cells hypoxic and was similar to that produced by exposing smooth muscle cells to KCl or directly to hypoxia.     

Effects of the myosin inhibitor 2,3-butanedione monoxime (BDM) on cell shape, locomotion and fluid pinocytosis in human polymorphonuclear leucocytes

We investigated the role of myosin in polymorphonuclear leucocyte (PMN) shape changes, locomotion, and fluid pinocytosis using the myosin inhibitor 2,3 butanedione monoxime (BDM). Treatment of resting spherical PMNs with BDM produced spheroid cells showing small continuous shape changes (IC(50)=15.5 m m BDM) and occasionally small blebs. Cell polarity, as induced by the chemotactic peptide fNLPNTL or by colchicine, and locomotion were completely suppressed (IC(50)=8.4 to 10 m m). Suppression of fNLPNTL- or colchicine-induced cell polarity produced spheroid cells, suppression of PMA-induced shape changes and fluid pinocytosis produced non-motile spherical cells (IC(50)=25 to 30 m m BDM). BDM suppressed formation of lamellipodia but not formation of blebs. Suppression of microvilli by BDM as observed in resting spherical cells was partially antagonized by PMA. The results suggest that myosin is involved in stabilizing the shape of resting spherical cells, including microvilli, and that myosin is required for cell polarity, locomotion, fluid pinocytosis and for formation of lamellipodia, but not for formation of blebs.     

Effects of paralysis with pancuronium on chest wall statics in awake humans

The influence of tonic inspiratory muscle activity on the relaxation characteristics of the chest wall, rib cage (RC), and abdominal wall (ABW) has been investigated in four highly trained subjects. Chest wall shape and volume were estimated with magnetometers. Pleural pressure (Pes) and abdominal pressure were measured with esophageal and gastric balloons, respectively. Subjects were seated reclining 30 degrees from upright, and respiratory muscle weakness was produced by pancuronium bromide until RC inspiratory capacity was decreased to 60% of control. Only minor changes were observed for Konno-Mead relaxation characteristics (RC vs. ABW) between control and paralysis. Similarly, although RC relaxation curves (RC vs. Pes) during paralysis were significantly different from control (P less than 0.05), the changes were small and not consistent. The differences between paralysis-induced changes in resting end-expiratory position of the chest wall and helium-dilution functional residual capacity (FRC) suggested changes in volume of blood within the chest wall. We conclude that 1) although tonic inspiratory activity of chest wall muscles exists, it does not significantly affect the chest wall relaxation characteristics in trained subjects; 2) submaximal paralysis produced by pancuronium bromide is likely to modify either spinal attitude or the distribution of blood between extremities and the thorax; these effects may account for the changes in FRC in other studies.     

Laryngeal muscle responses to mechanical displacement of the thyroid cartilage in humans.

Speakers may use laryngeal sensory feedback to adjust vocal fold tension and length before initiating voice. The mechanism for accurately initiating voice at an intended pitch is unknown, given the absence of laryngeal muscle spindles in animals and conflicting findings regarding their existence in humans. Previous reports of rapid changes in voice fundamental frequency following thyroid cartilage displacement suggest that changes in vocal fold length modulate laryngeal muscle contraction in humans. We tested the hypothesis that voice changes resulting from mechanical perturbation are due to rapid responses in the intrinsic laryngeal muscles. Hooked wire electrodes were used to record from the thyroarytenoid, cricothyroid, and sternothyroid muscles along with surface electrodes on the skin overlying the thyroid cartilage in 10 normal adults. Servomotor displacements produced consistent changes in the subjects' vocal fundamental frequency at 70-80 ms, demonstrating changes in vocal fold length and tension. No simultaneous electromyographic responses occurred in the thyroarytenoid or cricothyroid muscles in any subjects. Instead, short-latency responses at 25-40 ms following stimulus onset occurred in the sternothyroid muscles, simultaneous with responses in the surface recordings. The sternothyroid responses may modulate long-latency changes in voice fundamental frequency (approximately 150 ms). The absence of intrinsic laryngeal muscle responses is consistent with a lack of spindles in these muscles. Our results suggest that other sensory receptors, such as mucosal mechanoreceptors, provide feedback for voice control.     

An experimental neurovascular island skin flap for the study of the delay phenomenon.

We present an experimental neurovascular island skin flap. It is a consistent, reproducible model which produces a definite pattern of surviving skin flap area versus skin flap necrosis. There is a constant, anatomically definable nerve and vascular supply to the flap. This model permits independent experimental manipulation of the neural, arterial, and venous supply to the skin. It is useful, therefore, for the study of the vascular mechanisms of the skin microcirculation. We also demonstrated that increased flap survival can be produced by a delay involving denervation alone (leaving the vascular supply intact) or by devascularization alone (leaving the nerve supply intact). We conclude that both the adrenergic denervation and the ischemia contribute to the production of the delay phenomenon. We suggest that sustained vasodilation--vascular smooth muscle relaxation--is the vascular mechanism that accounts for the delay phenomenon.