The relation between intervertebral disc bulging and annular fiber associated strains for simple and complex loading

Mechanical failure of the annulus fibrosus is mostly indicated by tears, fissures, protrusions or disc prolapses. Some of these annulus failures can be caused by a high intradiscal pressure. This has an effect on disc bulging. However, it is not fully understood how disc bulging is related to disc loading. Therefore, the aim of this study was to investigate the annular fiber strains and disc bulging under simple and complex spinal loads. A novel laser scanner was used to image surfaces of six L2-3 segments. Specimens were loaded with 500 N or 7.5 Nm in a spine tester while acquiring surface maps. Loading was applied in the three principal main directions and four combined directions. Disc bulging and tissue surface strains in annulus collagen fiber directions were computed. Two conditions were measured; intact and defect (vertebral body-disc-body units). Axial compression resulted in 2.7% fiber associated strains in intact segments and the defect increased strains up to 6.7%. Disc bulging increased from 0.7 mm to 0.87 mm. Flexion produced 7.2% fiber associated strains and 1.63 mm bulge going up to 17.5% and 2.21 mm after the defect. Highest fiber associated strains were found for the combination of axial rotation plus lateral bending with 24.6% and with a maximal bulging of 1.14 mm. It was found that there is no tight relationship between fiber associated strains and disc bulging. This was especially seen for the load combinations. Highest fiber associated strains were found to be located in small posterolateral regions. Fiber associated strains had a much higher magnitude than previously reported fiber associated strains. The results showed that combined loading is most likely to produce higher associated fiber strains compared to single axis loading.     

Measurement of in vivo lumbar intervertebral disc pressure during spinal manipulation: a feasibility study

This paper presents the first reported measurements of lumbar intervertebral disc pressure in vivo during spinal manipulation. A pressure transducer was inserted into the nucleus pulposus of one normal-appearing lumbar disc in an asymptomatic adult volunteer. Pressures were recorded during several body positions and maneuvers, then during spinal manipulation, and lastly during a repetition of the preintervention body positions. Baseline pressures in the prone and side-lying positions measured 110 kPa and 150 kPa, respectively. During the manipulation, pressure rose to a peak of 890 kPa over 250 ms. Immediately following, pressures in the prone and side-lying positions measured 150 kPa and 165 kPa, respectively. These data do not support the hypotheses that manipulation can reduce a herniation by decreasing intradiscal pressure, or cause a herniation by raising pressure to failure levels. Further work may lead to a better understanding of this treatment method.     

Morphological and mechanical aspects of fission in Ophiocomella ophiactoides (Echinodermata,Ophiuroida)

Summary During fission the ophiuroid Ophiocomella ophiactoides splits across the disc into two halves each of which regenerates to form a complete individual. This paper describes the gross anatomy of the fission plane and the histology, ultrastructure, and mechanical properties of key structures transected during fission.Rupture of the disc integrument appears not to be facilitated by a pre-determined plane of weakness. Comparison of naturally split and artificially split animals showed that at fission a mechanism operates which restricts breakage to the interradial plane of two jaws. The interradial plane is subtended mainly by collagenous ligaments and by muscles linked to the skeletal components by basal lamina-like tendinous fibres. No fission-related adaptations could be identified in the oesophagus, circumoral nerve ring, or circumoral water vascular canal.On the basis of creep tests on isolated preparations of the disc integrument and jaw-frame and the responses of these preparations to ionic manipulation, it is suggested that their behaviour is dominated by collagenous elements that can undergo actively controlled changes in their mechanical properties. A hypothesis is presented which proposes a role for such a mechanism in the initiation and facilitation of fission.Contribution 318 of the Discovery Bay Marine Laboratory, University of the West Indies     

Transient nature of Toxoplasma gondii-induced behavioral changes in mice

Many parasites induce specific changes in host behavior that promote the transmission of their infective stages between hosts. Toxoplasmosis in rodents is known to be accompanied by specific behavioral changes (shift in activity level, learning capacity, and novelty discrimination) that can theoretically increase the chance of infected animals being eaten by the definitive host, the cat. However, toxoplasmosis is also accompanied by many pathological symptoms. It is not known whether the behavioral changes are products of manipulation activity of the parasite or only nonspecific by-products of pathological symptoms of toxoplasmosis. Here, we compared the dynamics of development of behavioral and pathological changes in Toxoplasma gondii-infected mice. The results showed that the maximum reduction of mouse activity corresponded with the peak of pathological symptoms, and also that maximum increase of reaction times corresponded with the peak of development of tissue cysts in the brains of infected mice. Behavioral changes were only transient and disappeared before the 12th wk postinoculation. The results suggest that the behavioral changes in infected mice reported by many authors and observed in our experiments could be nonspecific by-products of pathological symptoms of toxoplasmosis rather than specific products of manipulation activity by the parasite.     

Regulation of imaginal disc cell size, cell number and organ size by Drosophila class I(A) phosphoinositide 3-kinase and its adaptor.

BACKGROUND: Class I(A) phosphoinositide 3-kinases (PI 3-kinases) have been implicated in the regulation of several cellular processes including cell division, cell survival and protein synthesis. The size of Drosophila imaginal discs (epithelial structures that give rise to adult organs) is maintained by factors that can compensate for experimentally induced changes in these PI 3-kinase-regulated processes. Overexpression of the gene encoding the Drosophila class I(A) PI 3-kinase, Dp110, in imaginal discs, however, results in enlarged adult organs. These observations have led us to investigate the role of Dp100 and its adaptor, p60, in the control of imaginal disc cell size, cell number and organ size. RESULTS: Null mutations in Dp110 and p60 were generated and used to demonstrate that they are essential genes that are autonomously required for imaginal disc cells to achieve their normal adult size. In addition, modulating Dp110 activity increases or reduces cell size in the developing imaginal disc, and does so throughout the cell cycle. The inhibition of Dp110 activity reduces the rate of increase in cell number in the imaginal discs, suggesting that Dp110 normally promotes cell division and/or cell survival. Unlike direct manipulation of cell-cycle progression, manipulation of Dp110 activity in one compartment of the disc influences the size of that compartment and the size of the disc as a whole. CONCLUSIONS: We conclude that during imaginal disc development, Dp110 and p60 regulate cell size, cell number and organ size. Our results indicate that Dp110 and p60 signalling can affect growth in multiple ways, which has important implications for the function of signalling through class I(A) PI 3-kinases.     

Stained Ground Sections of Teeth and Bone

Formalin-fixed rat hemimandibles were ground to approximately 80μ with the aid of a diamond disc attached to a dental handpiece. A 1/10-hp motor attached to the handpiece by a pulley powered the disc to speeds up to 4000 rev/min. Contact between the hemimandible, which was placed on water-moistened cork, and the diamond disc was made possible through manipulation of the handpiece. The ground sections obtained by this procedure were stained with hematoxylin and eosin and periodic acid-Schiff for microscopic study. The fine structure of mineralized tissues (teeth and bones) as well as related soft structures, e.g., blood vessels, endosteum, pulp, etc., were demonstrated. The procedure did not require the embedding of the tissue nor were complicated grinding devices necessary.     

The Dentition and Feeding Mechanism in Adults of the Southern Hemisphere Lamprey Geotria australis Gray

Scanning electron micrographs of the teeth and sections and dissections of the head have been used to describe the functional interrelationships between the dentition and associated cartilages, muscles and ligaments in adults of the southern hemisphere lamprey Geotria australis. These studies, together with manipulation of the piston and oral disc in living specimens, elucidated the probable feeding mechanism in this species. The main cutting action appears to result from a scissoring movement brought about by the rapid interlocking of the three sharp and stout cusps of the transverse lingual lamina with large grooves on the rear face of the supraoral lamina. The movement of excised flesh back through the oral passage to the pharynx would be facilitated by the action of the pair of strongly cuspid longitudinal lingual laminae. The unique oral disc teeth of G. australis are apparently adapted to allow the disc to slide forward over the host and yet restrict any tendency to slip backwards.     

Breeding of a tomato genotype readily accessible to genetic manipulation

A tomato genotype, superior in regenerating plants from cell cultures, was obtained by transferring regeneration capacity from Lycopersicon peruvianum into L. esculentum by classical breeding. This genotype, MsK93, greatly facilitates genetic manipulation of tomato, as was demonstrated by successful leaf disc transformation using Agrobacterium tumefaciens and by direct gene transer to protoplasts derived from callus.     

Controlled trial of mobilisation and manipulation for low back pain: hospital patients.

Ninety-four patients with non-specific lumbar pain referred to hospital rheumatology and orthopaedic clinics participated in a double-blind controlled trial comparing mobilisation and manipulation with placebo physiotherapy. Results were assessed immediately after the tratment course, two months later, and at one year. Many patients showed improvement, but in contrast to a study on general-practitioner patients with nonspecific back pain no definite advantage could be associated with mobilisation and manipulation. The benefits of mobilisation and manipulation for low back pain are probably restricted to hastening recovery in patients likely rapidly to improve spontaneously. Hence patients whose severity and duration of symptoms warrant specialist referral are less likely to benefit from the technique.     

Increase of nerve growth factor levels in the human herniated intervertebral disc: can annular rupture trigger discogenic back pain?

Introduction

Nerve growth factor (NGF) has an important role in the generation of discogenic pain. We hypothesized that annular rupture is a trigger for discogenic pain through the action of NGF. In this study, the protein levels of NGF in discs from patients with disc herniation were examined and compared with those from discs of patients with other lumbar degenerative disc diseases.

Methods

Patients (n = 55) with lumbar degenerative disc disease treated by surgery were included. Nucleus pulposus tissue (or herniated disc tissue) was surgically removed and homogenized; protein levels were quantified using an enzyme-linked immunosorbent assay (ELISA) for NGF. Levels of NGF in the discs were compared between 1) patients with herniated discs (herniated group) and those with other lumbar degenerative disc diseases (non-herniated group), and 2) low-grade and high-grade degenerated discs. Patient’s symptoms were assessed using a visual analog scale (VAS) and the Oswestry disability index (ODI); the influence of NGF levels on pre- and post-operative symptoms was examined.

Results

Mean levels of NGF in discs of patients were significantly higher in herniated discs (83.4 pg/mg total protein) than those in non-herniated discs (68.4 pg/mg).No significant differences in levels of NGF were found between low-grade and high-grade degenerated discs. Multivariate analysis, adjusted for age and sex, also showed significant correlation between the presence of disc herniation and NGF levels, though no significant correlation was found between disc degeneration and NGF levels. In both herniated and non-herniated groups, pre-operative symptoms were not related to NGF levels. In the herniated group, post-operative lower extremity pain and low back pain (LBP) in motion were greater in patients with low levels of NGF; no significant differences were found in the non-herniated group.

Conclusions

This study reports that NGF increased in herniated discs, and may play an important role in the generation of discogenic pain. Analysis of patient symptoms revealed that pre-operative NGF levels were related to post-operative residual lower extremity pain and LBP in motion. The results suggest that NGF in the disc is related to pain generation, however, the impact of NGF on generation of LBP varies in individual patients.

Electronic supplementary material

The online version of this article (doi:10.1186/ar4674) contains supplementary material, which is available to authorized users.     

The Use of Chymopapain in Degenerative Disc Disease: A Preliminary Report

On the basis of the early results of the use of intradiscal injection of chymopapain in 15 patients with degenerative lumbar disc disease, the following statements are warranted: The injection can be beneficial in selected patients with lumbar disc disease. The relief of leg symptoms seems to be more striking than that of the accompanying low back symptoms although both are apparent. The exact mechanism by which pain is relieved is still obscure, but helpful information has been obtained from the early results of this investigation. The failure of chymopapain in carefully selected patients has resulted in only a brief time delay in operative intervention.     

HERNIATION OF INTERVERTEBRAL DISCS—An Evaluation of the “Indirect Signs”

The incidence of so-called indirect signs of posterior herniation of an intervertebral disc in a series of working men who had no symptoms referable to the back was compared with the incidence of those signs in a group of cases in which herniation of a disc was proved at operation. There was no significant difference in incidence. In the cases in which herniation was proved at operation, it occurred no more often at a level where there was a thin disc than at a level where the disc was of normal thickness.     

针刺联合红外线照射治疗腰椎间盘突出症的随机对照研究

目的：评价针刺联合红外线照射治疗腰椎间盘突出症的临床疗效。方法：选择2010 年9 月～2012 年1 月我院收治的90 例 腰椎间盘突出症患者为研究对象,并将其随机分为对照组和治疗组,每组45 例。对照组患者给予药物治疗,而治疗组患者给予针 刺联合红外线照射治疗,治疗后评价和比较两组患者的临床疗效及腰腿痛的改善情况。结果：针刺联合红外线照射治疗腰椎间盘 突出症显效率为62.2%,药物组显效率为26.7%,两组有显著性差异(Ｐ<0.05)。治疗后,治疗组患者腰腿痛疼痛评分明显低于对照 组,差异有统计学意义(P<0.01)。结论：以针刺联合红外线照射治疗腰椎间盘突出症的临床疗效肯定,值得临床推广。     

Herniation of intervertebral discs; an evaluation of the indirect signs

The incidence of so-called indirect signs of posterior herniation of an intervertebral disc in a series of working men who had no symptoms referable to the back was compared with the incidence of those signs in a group of cases in which herniation of a disc was proved at operation. There was no significant difference in incidence. In the cases in which herniation was proved at operation, it occurred no more often at a level where there was a thin disc than at a level where the disc was of normal thickness.     

儿童不典型黄癣1例报告及文献复习

报告1例由许兰毛癣菌(Trichophyton schoenleinii)引起的儿童不典型黄癣,患儿临床症状轻微,缺乏蜡黄色、碟形黄癣痂和特殊的鼠臭味等典型临床症状.病发真菌直接镜检见大量不规则菌丝,间生膨大,大小不等、形态不规则的孢子,真菌培养为许兰毛癣菌生长,经分子生物学测序鉴定证实.E-test药敏结果显示伊曲康唑、两性霉素B、卡泊芬净及伏立康唑均敏感.经口服伊曲康唑胶囊及外用2％舍他康唑乳膏治疗基本痊愈.     

Stretching of the sciatic nerve; a means of relieving postoperative pain following removal of ruptured lumbar intervertebral discs

Stretching the sciatic nerve for the relief of "sciatica" was frequently employed before 1900 and was subsequently abandoned, probably because it was done without sufficient scrutiny of the indications. The procedure has recently been employed in cases in which "sciatica" remains following the operative removal of ruptured intervertebral discs, and it has been instrumental in relieving postoperative "sciatica" when the cause was the formation of adhesions about the lumbar nerve roots. If the nerve root is compressed by recurrent disc protrusion or by adjacent bone, the manipulation usually increases the pain, a phenomenon that has been helpful from a diagnostic standpoint.     

Detection of genetically altered copper levels in Drosophila tissues by synchrotron x-ray fluorescence microscopy

Tissue-specific manipulation of known copper transport genes in Drosophila tissues results in phenotypes that are presumably due to an alteration in copper levels in the targeted cells. However direct confirmation of this has to date been technically challenging. Measures of cellular copper content such as expression levels of copper-responsive genes or cuproenzyme activity levels, while useful, are indirect. First-generation copper-sensitive fluorophores show promise but currently lack the sensitivity required to detect subtle changes in copper levels. Moreover such techniques do not provide information regarding other relevant biometals such as zinc or iron. Traditional techniques for measuring elemental composition such as inductively coupled plasma mass spectroscopy are not sensitive enough for use with the small tissue amounts available in Drosophila research. Here we present synchrotron x-ray fluorescence microscopy analysis of two different Drosophila tissues, the larval wing imaginal disc, and sectioned adult fly heads and show that this technique can be used to detect changes in tissue copper levels caused by targeted manipulation of known copper homeostasis genes.     

Preimplantation mammalian aggregation and injection chimeras

The preimplantation embryo is highly resilient to experimental manipulations. A specific manipulation that has revealed many clues to the developmental process is chimera production. Chimeras have been used to describe the importance of developmental characteristics of embryonic cells and how these characteristics are involved with developmental fate. These characteristics have been monopolized in the production of interspecific chimeras and the production of transgenic animals. This review attempts to discuss the major factors affecting preimplantation mammalian embryo chimera production.     

Epilimnetic and hypolimnetic symptoms of eutrophication in Great Mazurian Lakes, Poland

SUMMARY. An increase in the trophic state and productivity of a lake is not necessarily accompanied by a decrease in epilimnetic Secchi disc transparency. In smaller lakes with sharp thermoclines the symptoms of eutrophication may be more evident as a decrease in transparency in the epilimnion but, in larger lakes with poorly defined thermoclines, symptoms of eutrophication may be more evident in the hypolimnion as shown by an increase in the rate of hypolimnetic oxygen consumption.     

Cell-autonomous regulation of cell and organ growth in Drosophila by Akt/PKB

Organismal size is determined by a tightly regulated mechanism that coordinates cell growth, cell proliferation and cell death. The Drosophila insulin receptor/Chico/Dp110 pathway regulates cell and organismal size. Here we show that genetic manipulation of the phosphoinositide-3-OH-kinase-dependent serine/threonine protein kinase Akt (protein kinase B) during development of the Drosophila imaginal disc affects cell and organ size in an autonomous manner. Ectopic expression of Akt does not affect cell-fate determination, apoptosis or proliferation rates in imaginal discs. Thus, Akt appears to stimulate intracellular pathways that specifically regulate cell and compartment size independently of cell proliferation in vivo.