Head and Cervical Spine Posture in Behaving Rats: Implications for Modeling Human Conditions Involving the Head and Cervical Spine

The aim of this study was to define the temporal and spatial (postural) characteristics of the head and cervical vertebral column (spine) of behaving rats in order to better understand their suitability as a model to study human conditions involving the head and neck. Time spent in each of four behavioral postures was determined from video tape recordings of rats (n = 10) in the absence and presence of an intruder rat. Plain film radiographic examination of a subset of these rats (n = 5) in each of these postures allowed measurement of head and cervical vertebral column positions adopted by the rats. When single they were quadruped or crouched most (～80%) of the time and bipedal either supported or free standing for only ～10% of the time. The introduction of an intruder significantly (P < 0.0001) reduced the proportion of time rats spent quadruped (median, from 71% to 47%) and bipedal free standing (median, from 2.9% to 0.4%). The cervical spine was orientated (median, 25–75 percentile) near vertical (18.8°, 4.2°–30.9°) when quadruped, crouched (15.4°, 7.6°–69.3°) and bipedal supported (10.5°, 4.8°–22.6°) but tended to be less vertical oriented when bipedal free standing (25.9°, 7.7°–39.3°). The range of head positions relative to the cervical spine was largest when crouched (73.4°) and smallest when erect free standing (17.7°). This study indicates that, like humans, rats have near vertical orientated cervical vertebral columns but, in contrast to humans, they displace their head in space by movements at both the cervico‐thoracic junction and the cranio‐cervical regions. Anat Rec, 298:455–462, 2015. © 2014 Wiley Periodicals, Inc.     

术前体位训练对甲状腺手术体位综合征的影响

目的 探讨术前体位训练对甲状腺手术体位综合征的影响.方法 随机将485例甲状腺手术患者分为两组,A组200例,术前不进行体位训练.B组285,术前进行体位训练,直至能坚持体位到手术所需要的时间.然后对2组患者术中及术后48h内出现头痛、呕吐进行观察,记录头痛、呕吐发生数,进行统计学分析.结果 B组头痛发生率明显少于A组(P<0.01),呕吐发生率明显少于A组(P<0.01).结论 术前体位训练可有效地预防甲状腺手术体住综合征的发生,有利于患者的康复,值得临床推广应用.     

Osteometric Dimensions of the Laminas of the Spine

The present study was undertaken to evaluate the dimensions of the laminas from C2 to L5 by using adult human spine specimens for the objective of providing a set of quantitative data for the laminas from C2 to L5 vertebrae.There exists enormous amount of Anatomic data based on facet and pedicle parameters by different research workers, but it seems that the detailed studies based on measurements of laminar parameters from cervical to lumbar spines are almost nil.Forty spines (920 vertebrae) were considered for the present study. Anatomic evaluation of the laminas'included the laminar height, width, thickness, width angle & slope angle.The greatest laminar height was observed at T11 for males & females ( 22.8 ± 2.1 mm, 23.0 + 1.8mm) respectively. There was a marked change in pattern at L5 where there was a decrease in laminar height from that of preceding lumbar levels.The greatest laminar width was at-L5 for males & females (12.1 ± 2.4mm 11.5 ± 2.1 mm ) respectively. The laminar thickness was maximum at T3 for males and females (5:2 ± 0.7mm & 5.1 ± 0.2mm ) respectively. The maximum width angle was at T9 for males (99.2 ± 9.7mm) & at L4for females (100.6 ± 12.3mm). The-slope angle was maximum at L5 for males and females (113.5 ± 4.8mm & 118.0 ± 1.4mm) respectively.Thus, for the proper, understanding of the weight transmission through the spine and it related hypothesis the Anatomic parameters of the laminas provided by the present study are very important and also they provide an adequate database necessary for the surgical placement of sublaminar instruments in spine related surgeries.     

踝前区与足背部腓深神经的解剖学观察

目的探讨腓深神经在踝前区及足背部的解剖走行情况,为带神经血管蒂的足背复合组织瓣的切取提供解剖学参考。方法解剖17具尸体的双下肢,观察踝前区及足背部腓深神经走行,并观察与足背动脉的位置关系。结果踝前区及足背部的腓深神经在行程中多处与足背动脉出现交叉。结论腓深神经和足背动脉的交叉位置关系出现几率不同,在外科手术和皮瓣制作时要了解此处腓深神经和足背动脉的位置。     

Spindle Cell Neoplasm of the Thoracic Spine

The case is a 56-year-old woman who presented with cord compression from a lesion of the thoracic spine. Histologic analysis confirmed the diagnosis of a spindle cell sarcoma. Ultrastructural analysis showed features characteristic of a leiomyosarcoma. Subsequent discussion with the patient revealed a history of hysterectomy performed for fibroid uterus 5 years before the current presentation. Review of the previous surgical specimen confirmed the presence of a leiomyosarcoma originally interpreted as a large infarcted myoma.     

Activity of Pilomotor Muscles of Single Tactile Hairs in the Cat

Contractions of the pilomotor muscles of individual carpal tactile sinus hairs in the cat were studied by simultaneous recording of the movement of a single hair by means of a capacitance meter, and of the electrical activity during the muscle contraction, as recorded by an external metal microelectrode. Single shock stimulation of the nerve gave rise to a twitch contraction, whereas repetitive stimulation caused summation of contractions at frequencies higher than 0.2/sec and fusion at frequencies of 1/sec or more. The electrical response consisted of a slow potential and a superimposed spike. These components were both shown to be dependent on the stimulus strength and to be facilitated on repetitive stimulation. At stimulus frequencies higher than 3/sec the spike gradually declined in amplitude and was substituted by a rhythmic oscillation at the same rate as the stimulus. Even when no spike was recorded the contraction was sustained. Comparisons are made between the electrical activity elicited in the pilomotor muscles and the junction potentials and spikes recorded in other types of smooth muscle.     

颈椎自锁ZEPHIR钢板在外伤性颈椎失稳治疗中的应用

目的：探讨颈椎前路ZEPHIR钢板内固定在外伤性颈椎失稳中应用的临床效果。方法：对15例外伤性颈椎失稳患者行颈椎前路减压、自体髂骨植骨和ZEPHIR钢板内固定术，并对术后植骨愈合、神经功能恢复进行观察。结果：15例患者术后随访6．24个月，平均11个月，椎间植骨均在术后3个月内临床愈合，所有病例神经功能按Frankel分级，均有1～2个级别恢复。本组无严重并发症。结论：ZEPHIR钢板具备优良的植入物设计和力学性能。颈椎前路减压、自体髂骨植骨和ZEPHIR钢板内固定术后颈椎获得即刻稳定，无需附加牢固的外固定，能显著提高植骨融合率。     

Destabilization of the Upright Posture Through Elevation of the Center of Mass

The inverted pendulum model predicts that the major challenge for neural control of the upright posture is the inherent instability of the body due to the center of mass (COM) being above the base of support (BOS). If so, even slight elevation of the COM may substantially destabilize posture. The destabilizing effect of heavy load positioned above the COM has been demonstrated. We examined sensitivity of posture to light (1–5% of body weight) load by placing weights on the shoulders and assessing functional reach distance in the forward, right, and left directions and postural sway during quiet stance. At each load level, the quiet stance task was tested with and without vision. The 1% of body weight load significantly shortened reach distance in the forward direction. It also increased postural sway. Interestingly, additional weight did not result in further deficits. The results support high sensitivity of postural stability to COM elevation that increases the challenge for neural control of posture and that can potentially be used for early detection of declines in postural stability.     

右肺动脉叶间干的应用解剖学

在30例成尸标本上对右肺门角顶点的位置和右肺动脉叶间干进行了观测。右肺门角顶点位于右中叶动脉起始部者占67%,位于起始部以上者占23%,位于右肺动脉叶间干末端者占10%。右肺动脉叶间干长约21.3mm,上、中1/3段交界处:中、下1/3段交界处及末端的外径分别是11.7mm、11.1mm 和8.9mm。     

Tactile input of the hand and the control of reaching to grasp movements

Phosphorus magnetic resonance spectroscopy (³¹P MRS) was used to determined whether focal cerebral injury caused by unilateral carotid artery occlusion and graded hypoxia in developing rats led to a delayed impairment of cerebral energy metabolism and whether the impairment was related to the magnitude of cerebral infarction. Forty-two 14-day-old Wistar rats were subjected to right carotid artery ligation, followed by 8% oxygen for 90 min. Using a 7T MRS system,³¹P brain spectra were collected during the period from before until 48 h after hypoxia-ischaemia. Twenty-eight control animals were studied similarly. In controls, the ratio of the concentration of phosphocreatine ([PCr]) to inorganic orthophosphate ([Pi]) was 1.75 (SD 0.34) and nucleotide triphosphate (NTP) to total exchangeable phosphate pool (EPP) was 0.20 (SD 0.04): both remained constant. In animals subjected to hypoxia-ischaemia, [PCr] to [Pi] and [NTP] to [EPP] were lower in the 0- to 3-h period immediately following the insult: 0.87 (0.48) and 0.13 (0.04), respectively. Values then returned to baseline level, but subsequently declined again: [PCr] to [Pi] at −0.02 h⁻¹ (P<0.0001). [PCr] to [Pi] attained a minimum of 1.00 (0.33) and [NTP] to [EPP] a minimum of 0.14 (0.05) at 30–40 h. Both ratios returned towards baseline between 40 and 48 h. The late declines in high-energy phosphates were not associated with a fall in pH_i. There was a significant relation between the extent of the delayed impairment of energy metabolism and the magnitude of the cerebral infarction (P<0.001). Transient focal hypoxia-ischaemia in the 14-day-old rat thus leads to a biphasic disruption of cerebral energy metabolism, with a period of recovery after the insult being followed by a secondary impaiment some hours later.     

Perceptual constancy and the perceived magnitude of muscle forces

The present study used a force-matching task to measure how accurately subjects could match a force using different muscle groups. Forces ranging in magnitude from 2 to 10 N were produced and matched by three muscle groups: the elbow flexors, the forearm and hand muscles involved in the palmar prehensile grasp, and the index finger flexors. The ability to match forces was considered in terms of precision, that is, how closely the matching forces approximated the reference force produced on the contralateral side, and accuracy, which is the reproducibility of the matching force estimates. The results indicated that the perceived magnitude of forces varied as a function of the muscle group generating the force. Forces produced by the index finger flexors were consistently overestimated in magnitude when matched by elbow flexion forces, and elbow forces were underestimated when matched by flexing the index finger. When evaluated in terms of constant and absolute errors, the index finger flexors were the most precise matching muscle group and the elbow flexors the least precise. These results suggest that forces are perceived relatively, and are scaled with reference to the operating range of the muscles. They also indicate that there is little perceptual constancy in the perceived magnitude of forces generated by different muscle groups.     

Perceptual distortions in the neural representation of visual space

 The visual mechanism by which human observers determine the separation between objects has long been of interest. This study examines the extent to which separation in visual space can be misperceived in foveal and extrafoveal vision. Foveally, vertical separations were consistently overestimated relative to horizontal separations, a result which is consistent with the well-documented horizontal-vertical illusion (HVI). Extrafoveally, much larger misrepresentations of visual space were perceived. In addition, separations tangential to fixation were consistently perceived as being greater than separations in a radial direction. These marked misperceptions of visual space which occur in extrafoveal vision take the form of a radial/tangential anisotropy combined with an overestimation of vertical distance. The results have important implications for meridional anisotropies which have previously been documented in a number of visual performance tasks. Received: 17 July 1998 / Accepted: 14 October 1998