Thermoesthesia and algesthesia in the dermatomes of the cauda equina roots in patients with lumbar spinal osteochondrosis

Disorders of thermoesthesia and algesthesia are characteristic of the dermatomes of the cauda equina roots in patients with lumbar spine osteochondrosis. The negative changes in sensitivity are manifested in (1) an increase of the threshold by 2?C8 degrees; (2) a decrease of the threshold by 3?C6 degrees; (3) the absence of thermal sensitivity. In the presence of reflex syndromes (lumbalgia and lumbar ischialgia), the most severe disorders were in L ₄, L ₅, and S ₁ dermatomes. In patients with radicular syndromes, abnormal thermoesthesia and algesthesia were more pronounced than in patients with the reflex syndromes. Combined conservative therapy resulted in improvement of thermoesthesia and algesthesia mostly in the L ₅ dermatome of patients with lumbalgia and lumbar ischialgia. Treatment of patients with radicular syndrome did not lead to any significant improvement of the thermal or pain sensitivity of the limb with radiculopathy or in dermatome of the root compressed. More pronounced changes were observed in the contralateral limb.     

Pathobiomechanical impairments of the vertebral column in intervertebral disk protrusion and herniation

Magnetic resonance imaging of patients with intervertebral disk herniation was used to study the stages of degenerative and dystrophic processes in the spinal structures in the presence of intervertebral disk protrusion and herniation. Differences were found in the pathobiomechanical mechanisms in the spinal motor segments of herniation and protrusion in the area of their localization and in the adjacent spinal motor segments. Among the symptoms traditionally analyzed, joint facet joint arthritis and arthrosoarthritis classified as spondyloarthritis by radiodiagnosis were examined for their impact on the rate of herniation and protrusion.     

MRI and computerized tomography in the evaluation of lumbar spine after herniated disk surgery]

The authors analyze the results of comprehensive radio-diagnosis in 44 patients previously operated on for lumbar hernias. All the findings of magnetic resonance tomography and computer-aided tomography were divided into 3 groups: (1) natural consequences of a surgical intervention without clinical manifestations; (2) complications after a surgical intervention; (3) recurrent hernias or hernias on an adjacent level. The most intricate problem was the differential diagnosis between a recurrent hernia and a postoperative epidural cicatrix. Criteria to distinguish between these two conditions are suggested. The authors emphasize that the optimal variant for examination of the patients operated on is a combination of magnetic resonance tomography and computer-aided tomography.     

The viscoelastic standard nonlinear solid model: predicting the response of the lumbar intervertebral disk to low-frequency vibrations

Due to the mathematical complexity of current musculoskeletal spine models, there is a need for computationally efficient models of the intervertebral disk (IVD). The aim of this study is to develop a mathematical model that will adequately describe the motion of the IVD under axial cyclic loading as well as maintain computational efficiency for use in future musculoskeletal spine models. Several studies have successfully modeled the creep characteristics of the IVD using the three-parameter viscoelastic standard linear solid (SLS) model. However, when the SLS model is subjected to cyclic loading, it underestimates the load relaxation, the cyclic modulus, and the hysteresis of the human lumbar IVD. A viscoelastic standard nonlinear solid (SNS) model was used to predict the response of the human lumbar IVD subjected to low-frequency vibration. Nonlinear behavior of the SNS model was simulated by a strain-dependent elastic modulus on the SLS model. Parameters of the SNS model were estimated from experimental load deformation and stress-relaxation curves obtained from the literature. The SNS model was able to predict the cyclic modulus of the IVD at frequencies of 0.01 Hz, 0.1 Hz, and 1 Hz. Furthermore, the SNS model was able to quantitatively predict the load relaxation at a frequency of 0.01 Hz. However, model performance was unsatisfactory when predicting load relaxation and hysteresis at higher frequencies (0.1 Hz and 1 Hz). The SLS model of the lumbar IVD may require strain-dependent elastic and viscous behavior to represent the dynamic response to compressive strain.     

Responsibility and the sense of agency enhance empathy for pain

Being held responsible for our actions strongly determines our moral judgements and decisions. This study examined whether responsibility also influences our affective reaction to others'' emotions. We conducted two experiments in order to assess the effect of responsibility and of a sense of agency (the conscious feeling of controlling an action) on the empathic response to pain. In both experiments, participants were presented with video clips showing an actor''s facial expression of pain of varying intensity. The empathic response was assessed with behavioural (pain intensity estimation from facial expressions and unpleasantness for the observer ratings) and electrophysiological measures (facial electromyography). Experiment 1 showed enhanced empathic response (increased unpleasantness for the observer and facial electromyography responses) as participants'' degree of responsibility for the actor''s pain increased. This effect was mainly accounted for by the decisional component of responsibility (compared with the execution component). In addition, experiment 2 found that participants'' unpleasantness rating also increased when they had a sense of agency over the pain, while controlling for decision and execution processes. The findings suggest that increased empathy induced by responsibility and a sense of agency may play a role in regulating our moral conduct.     

Morphological changes in the apex of pea roots during and after recovery from aluminium treatment

We investigated how the pea (Pisum sativum cv. Harunoka) root, upon return to an Al-free condition, recovers from injury caused by exposure to Al. The growing region of the root during and after treatment with Al was examined by marking the root at intervals with India ink. Al-induced cell death was detected by staining with Evans blue. Root growth in 40 μM Al solution relative to that in Al-free solution (RRG) was approximately 45% from 6 h to12 h after the start of the treatment. However, values of RRG from 12 h to 24 h in Al-free solution for recovery or in the same Al solution were about 75% and 35%, respectively, indicating recovery from Al-induced growth inhibition. Images of the root characterized by zonal staining with Evans blue were observed in the sub-apical region (more than 1 mm from the tip) in Al-stressed roots. However, the interval of the stained zone was widened in the root after recovery from Al-induced growth inhibition, though it was narrower and more densely stained with time in the Al-stressed roots. During the recovery, the root apex may resume elongation in a specified region without Al-induced death or injury in cells detected by Evans blue.     

The influence of body temperature and castration on the protein composition of fluid in the rat cauda epididymidis

Polyacrylamide gel electrophoresis under reducing and non-reducing conditions, and immunoelectrophoretic analysis, revealed that several characteristic proteins disappear from the luminal fluid of the rat cauda epididymidis when it is maintained at body temperature. On SDS-PAGE gels prepared under reducing conditions, one Coomassie-blue staining band of Mr 18,000 disappeared and another of 52,000 was significantly reduced after only 6 days; bands of Mr 23,000, several in the Mr 34-38,000 range, one of Mr 48,000, and others of Mr 100-200,000 were eliminated or markedly reduced after 15 days at body temperature. Some were glycoprotein, as judged by their affinity for FITC-ConA. At 15 days after castration there was a broadly similar but rather more extensive disappearance of macromolecules, and of glycoproteins in particular, from caudal fluid. The fact that several similar proteins are diminished in or disappear from fluid or the cauda epididymidis maintained at body temperature, or after androgen withdrawal, raises the possibility that one or more such proteins play a role in sperm storage there.     

A combined numerical and experimental technique for estimation of the forces and moments in the lumbar intervertebral disc

Evaluation of the loads on lumbar intervertebral discs (IVD) is critically important since it is closely related to spine biomechanics, pathology and prosthesis design. Non-invasive estimation of the loads in the discs remains a challenge. In this study, we proposed a new technique to estimate in vivo loads in the IVD using a subject-specific finite element (FE) model of the disc and the kinematics of the disc endplates as input boundary conditions. The technique was validated by comparing the forces and moments in the discs calculated from the FE analyses to the in vitro experiment measurements of three corresponding lumbar discs. The results showed that the forces and moments could be estimated within an average error of 20%. Therefore, this technique can be a promising tool for non-invasive estimation of the loads in the discs and may be extended to be used on living subjects.     

正常山羊腰椎间盘营养途径的DCE-MRI观察

目的 研究正常山羊腰椎间盘软骨终板营养途径.方法 选取健康24月龄山羊8只,每只山羊观察4个腰椎间盘,共32个腰椎间盘.麻醉后,行磁共振动态增强扫描,观察感兴趣区的信号变化特点.分别测量增强前及增强后0 min、5 min、10 min、30 rain、1 h、1.5 h、2 h,2.5 h、3 h、3.5 h感兴趣区信号强度值,分析时间-信号强度曲线及峰值出现时间.结果 椎体磁共振信号强度在0 min时达到高峰后迅速下降;软骨终板区在30 min时缓慢达到第一高峰后轻度下降,于2 h上升达到第二高峰;髓核在5 min内为负值,之后缓慢上升于2 h达到高峰,随后逐渐下降.结论 正常山羊腰椎椎间盘主要通过软骨终板途径进行营养代谢.     

Policy for controlling pain after surgery: effect of sequential changes in management.

OBJECTIVE--To observe the effects of introducing an acute pain service to the general surgical wards of a large teaching hospital. DESIGN--A study in seven stages: (1) an audit of current hospital practice succeeded by the sequential introduction to the general surgical wards of (2) pain assessment charts; (3) an algorithm to allow more frequent use of intramuscular analgesia; (4) increased use of local anaesthetic techniques of wound infiltration and nerve blocks; (5) an information sheet for patients about postoperative pain; (6) the introduction of patient controlled analgesia; (7) a repeat audit of hospital practice. Data were collected on each patient 24 hours after operation. SETTING--University Hospital of Wales, which has both district general and tertiary referral functions. PATIENTS--2035 patients over nine months from all surgical specialties (excluding cardiac) at the hospital. General surgical operations were studied in detail and separated into major, intermediate, and minor for data collection. MAIN OUTCOME MEASURES--A change in the median visual analogue pain scores 24 hours after surgery for pain during relaxation, pain on movement, and pain on deep inspiration at each stage of the study. RESULTS--There was a reduction in median visual analogue scores during the study. The median (95% confidence interval) scores for pain during relaxation decreased from 45 (34 to 53) in stage 1 to 16 (10 to 20) in stage 7 for major surgical procedures. Pain on movement decreased from 78 (66 to 80) to 46 (38 to 48), and pain on deep inspiration decreased from 64 (48 to 78) to 36 (31 to 38). The reductions in median scores for intermediate and minor operative procedures showed similar patterns. CONCLUSIONS--The introduction of an acute pain service to the general surgical wards led to considerable improvement in the level of postoperative pain as assessed by visual analogue scores. Simple techniques of regular pain assessment and the more frequent use of intramuscular analgesia as a result of using an algorithm were particularly effective.     

Effect of microgravity on the biomechanical properties of lumbar and caudal intervertebral discs in mice

Prolonged exposure to microgravity has shown to have deleterious effects on the human spine, indicated by low back pain during spaceflight and increased incidence of post-spaceflight herniated nucleus pulposus. We examined the effect of microgravity on biomechanical properties of lumbar and caudal discs from mice having been on 15-day shuttle mission STS-131. Sixteen C57BL/C mice (spaceflight group, n=8; ground-based control group, n=8) were sacrificed immediately after spaceflight. Physiological disc height (PDH) was measured in situ, and compressive creep tests were performed to parameterize biomechanical properties into endplate permeability (k), nuclear swelling pressure strain dependence (D), and annular viscoelasticity (G). For caudal discs, the spaceflight group exhibited 32% lower PDH, 70% lower D and crept more compared to the control mice (p=0.03). For lumbar discs, neither PDH nor D was significantly different between murine groups. Initial modulus, osmotic pressure, k and G for lumbar and caudal discs did not appear influenced by microgravity (p>0.05). Decreases in both PDH and D suggest prolonged microgravity effectively diminished biomechanical properties of caudal discs. By contrast, differences were not noted for lumbar discs. This potentially deleterious interaction between prolonged weightlessness and differential ranges of motion along the spine may underlie the increased cervical versus lumbar disc herniation rates observed among astronauts.     

Hyperosmotically induced volume change and calcium signaling in intervertebral disk cells: the role of the actin cytoskeleton

Loading of the spine alters the osmotic environment in the intervertebral disk (IVD) as interstitial water is expressed from the tissue. Cells from the three zones of the IVD, the anulus fibrosus (AF), transition zone (TZ), and nucleus pulposus (NP), respond to osmotic stress with altered biosynthesis through a pathway that may involve calcium (Ca(2+)) as a second messenger. We examined the hypothesis that IVD cells respond to hyperosmotic stress by increasing the concentration of intracellular calcium ([Ca(2+)](i)) through a mechanism involving F-actin. In response to hyperosmotic stress, control cells from all zones decreased in volume and cells from the AF and TZ exhibited [Ca(2+)](i) transients, while cells from the NP did not. Extracellular Ca(2+) was necessary to initiate [Ca(2+)](i) transients. Stabilization of F-actin with phalloidin prevented the Ca(2+) response in AF and TZ cells and decreased the rate of volume change in cells from all zones, coupled with an increase in the elastic moduli and apparent viscosity. Conversely, actin breakdown with cytochalasin D facilitated Ca(2+) signaling while decreasing the elastic moduli and apparent viscosity for NP cells. These results suggest that hyperosmotic stress induces volume change in IVD cells and may initiate [Ca(2+)](i) transients through an actin-dependent mechanism.     

Functional recovery following manipulation of muscles and sense organs in the stick insect leg

We studied functional recovery of leg posture and walking behaviour in the femur-tibia joint control system of stick insects. Leg extensions in resting animals and during walking are produced by different parts of a single extensor muscle. (a) Ablation of the muscle part responsible for fast movements prevented leg extension during the swing phase. Resting posture remained unaffected. Within a few post-operative days, extension movements recovered, provided that sensory feedback was available. Extension movements were now driven by the muscle part which in intact animals controls the resting posture only. (b) Selective ablation of this (slow) muscle part affected the resting posture, while walking was unaffected. The resting posture partly recovered during subsequent days. To test the range of functional recovery and underlying mechanisms, we additionally transected muscle motor innervation, or we inverted or ablated sensory feedback. We found that recovery was based on both muscular and neuronal mechanisms. The latter required appropriate sensory feedback for the process of recovery, but not for the maintenance of the recovered state. Our results thus indicate the existence of a sensory template that guides recovery. Recovery was limited to a behavioural range that occurs naturally in intact animals, though in different behavioural contexts.     

Times for recovery from cold-torpor in the Queensland fruit fly Dacus tryoni: the relation to temperature during and after chilling

Recovery time after experience of a given minimum temperature below torpor threshold is related to the value of that minimum, the length of time spent at that minimum, and the temperature prevailing during the recovery period above torpor threshold. A model can predict recovery time for flies experiencing a given temperature fluctuation if the length of time spent at the minimum is expressed as a proportion of LE₅₀ at that minimum.The model has applications in defining the optimal protocol for chilling insects for use in the Sterile Insect Release Method. The model was confirmed by experiments showing that it is likely that flies will recover from non-lethal frosts before ant predators become active.

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Résumé Le temps de récupération après avoir subi une température minimal située au-dessous du seuil d'engourdissement dépend de la valeur de ce minimum, du temps passé à ce minimum, et de la température au-dessus du seuil d'engourdissement pendant la période de récupération. Un modèle mathématique permet d'estimer le temps de récupération après avoir subi une chute de température déterminée, en fonction du temps passé au minimum thermique exprimé comme une fraction du LE₅₀ (temps nécessaire pour tuer 50% des mouches) à ce minimum.Ce modèle s'est trouvé étayé par des observations montrant qu'il est probable que les mouches se remettent des gelées sublétales avant la reprise d'activité des fourmis prédatrices. Ce modèle peut être utilisé pour définir les conditions optimales de refroidissement des insectes utilisés lors de la libération d'individus stériles.

     

The effect of different temperature regimens in reperfusion on the recovery of myocardial contractile function after hypothermic cardiac ischemia]

The changes of the contractile function of the heart and cAMP content in myocardium depending on the temperature conditions of reperfusion (28 degrees C, 32 degrees C, 37 degrees C) after 90 minutes of hypothermal ischemia have been investigated on isolated hearts of rats. The comparative analysis of the investigation results has shown that, after cooling a cardial muscle to 8-12 degrees C, reperfusion with initial temperature of perfusate of 32 degrees C promotes fast restoration of independent cardiac activity, does not cause formation of reperfusion contracture, normalizes processes of synthesis and cAMP utilization in cardiomyocytes.     

The influence of the storage temperature and cryopreservation conditions on the extent of human sperm DNA fragmentation

We explored the influence of different storage temperature conditions, including different methods of cryopreservation, on the structure of DNA organization in human sperm using a direct labeling procedure for detecting DNA fragmentation. Nineteen sperm samples that were obtained from healthy men with normozoospermia (according to the criteria of the World Health Organization) were used for the investigation. A significant increase in human sperm DNA fragmentation was observed 8 h after the incubation at +39°C (by 76.7%) and at +37°C (by 68.9%). It was found that cooling the sperm with a cryoprotectant immediately after thawing did not produce a significant difference in the extent of DNA fragmentation; however, the samples that contained cryoprotectants showed a sharp increase in the DNA fragmentation 24 h after the incubation, which could suggest cryoprotectant cytotoxicity.