Morphogenesis of structural elements of the cervical spine in the white rat in prenatal ontogeny

Embryonal development of the spinal column cervical part has been studied in 100 series of sagittal, transversal, frontal sections; time of the main structural elements anlagen (vertebral bodies, arches, joints, ligaments) is noted. The prenatal development of the spinal column cervical part is divided into 3 stages--mesenchymal, cartilagenous, osseous. The first stage lasts up to 16 days of development; during this period anlagen of vertebral bodies, arches, joints, ligaments are formed. The second stage--cartilagenous; mesenchyma is substituted for cartilagenous tissue, cartilagenous cells are differentiated. This stage lasts from the 16th up to the 18th day of embryogenesis. The third stage--osseous--lasts from the 18th up to the 21st day of embryogenesis. During this period structures of the spinal column cervical part acquire a definitive form, the cartilagenous tissue is substituted for the osseous one.     

Teratogenic potentially of single dose of thalidomide in JW-NIBS rabbits

A single dose (500 mg/kg) of thalidomide was administered orally to pregnant JW-NIBS rabbits in various stages of organogenesis. Head anomalies in fetuses (anencephaly, holoprosencephaly and hydrocephaly) were induced at a high frequency by the maternal administration of thalidomide on day 7, and also in a few fetuses on day 8. These fetuses included those with an abnormal skull such as hypoplasia of cerebral and facial skull. Microphthalmia in fetuses was observed with a single administration from day 7 to 12 of gestation. Contracture of forearms and club foot in fetuses resulted from the maternal administration of thalidomide on day 8 or 9 of gestation, respectively. With a single administration on day 8 or 9 of gestation, kinky tail in fetuses resulted, and brachyury was observed with a high frequency from day 8 to 11 of gestation. Skeletal anomalies such as fusion or displacement of coccygeal vertebral bodies were observed at a high frequency with a single treatment from day 8 to 10 of gestation. Among the internal anomalies observed was abnormal lobation of the lung, resulting from a single treatment from day 6 to 15 of gestation (except for day 13), and abnormal lobation of the liver, induced from day 7 to 10. The cardiovascular anomalies were induced at a high frequency with a single treatment from day 7 to 9 of gestation. In the present experiment, the critical period for each anomaly produced by thalidomide in JW-NIBS rabbits was determined.     

人脊髓创伤后神经元病变的神经丝免疫组织化学研究

本文用神经丝（ＮＦ）免疫组织化学方法在１５例人体尸检材料中研究了脊髓创伤后生存２ｈ～９Ｗ的脊髓神经元胞体和轴突的病理学改变。结果表明：脊髓创伤后２ｈ,神经丝免疫组织化学反应即可显示ＮＦ阳性反应产物在轴突内聚集。创伤后第４天,病变的前角运动神经元胞体内神经丝反应异常地增强。以上结果表明：神经丝免疫组织化学方法比常规显示轴突的染色方法能更早更清晰地显示脊髓内轴突的病变,并进一步证实了创伤后细胞骨架紊乱在神经元的病理发病机理中起重要作用。     

Musculoskeletal deformities following treatment of Wilms' tumour.

Wilms'' tumour is one of the most common neoplasms of infancy and childhood. Current treatment regimens result in a cure rate of about 80% for localized tumours but may also cause musculoskeletal deformities. Assessment of 21 patients previously treated for Wilms'' tumour showed that all had flank atrophy on the treated side. Radiologic abnormalities included asymmetry of vertebral bodies, vertebral end-plate irregularities, scoliosis, kyphosis, platyspondyly and hypoplasia of the ilium. Although the vertebral changes following radiotherapy for Wilms'' tumour are present from an early age and the potential is great for an increase in spinal deformity with growth, few spinal curves progress past 20 degree. Since one cannot predict which curves will progress, all such patients need careful orthopedic follow-up until skeletal maturity is achieved.     

Effect of pamidronate treatment on vertebral deformity in children with primary osteoporosis. A pilot study using radiographic morphometry

OBJECTIVE: Bisphosphonates are effectively used in treatment for primary osteoporosis in children. In the present study, we quantitatively evaluated the effect of pamidronate treatment on lumbar vertebrae in children with primary osteoporosis using radiographic morphometry. METHODS: Paired lateral radiographs of the lumbar spine were obtained before and after pamidronate treatment in 5 children with primary osteoporosis. To characterize vertebral deformities, specific morphometrical ratios were calculated for vertebral bodies L1-L4. RESULTS: Significant reshape of lumbar vertebrae was observed: the concavity index (middle-anterior ratio) decreased from 55 to 36% (p = 0.006), and the anterior-posterior ratio (used as a surrogate of wedge deformity) decreased from 25 to 11% (p = 0.001). CONCLUSIONS: Pamidronate treatment significantly influences the restoration of vertebral fractures in children with primary osteoporosis. The present study demonstrates that radiographic morphometry is a suitable tool for quantitative assessment of the vertebral deformities in childhood.     

Teleosts as models for human vertebral stability and deformity

Vertebral development is a dynamic and complicated process, and defects can be caused by a variety of influences. Spinal curvature with no known cause (idiopathic scoliosis) affects 2-3% of the human population. In order to understand the etiology and pathogenesis of complex human skeletal defects such as idiopathic scoliosis, multiple models must be used to study all of the factors affecting vertebral stability and deformity. Although fish and humans have many of the same types of offenses to vertebral integrity, they have been overlooked as a resource for study. The most common morphological deformity reported for fish are those that occur during the development of the spinal system, and as with humans, curvature is a common morphological consequence. Here we review spinal curvature in teleosts and suggest that they are an unexploited resource for understanding the basic elements of vertebral stability, deformity, development and genetics. Fish can be a value to vertebral research because they are tractable, have a diversity of non-induced vertebral deformities, and substantial genomic resources. Current animal models lack non-induced deformities and the experimental tractability necessary for genetic studies. The fact that fish are free of an appendicular skeleton should allow for analysis of basic spinal integrity without the biomechanical constraints observed in quadrupedal and bipedal models. To illustrate the point we review human idiopathic scoliosis and the potential contribution teleosts can make for the identification of causes, risk factors, and treatment options.     

Prevention of polydactyly manifestation in Polydactyly Nagoya (Pdn) mice by administration of cytosine arabinoside during pregnancy

Male mice heterozygous for the dominant polydactyly gene Pdn (Polydactyly Nagoya) were crossed with normal or heterozygous females of the same strain. Pregnant females were treated with 5 mg/kg of cytosine arabinoside (Ara-C) on day 12 of gestation. The offspring were removed on day 18 of gestation and examined for external malformations, and the fore- and hindlimbs were examined by means of bone- and cartilage-stained cleared specimens. In +/+ x Pdn/+ matings, Pdn/+ fetuses, bearing preaxial polydactyly of the distal phalangeal type in the hindlimb and deformity of the 1st digit in the forelimb, were obtained in about 50% of the nontreated group. In treated fetuses, however, the incidence of polydactyly and deformity of the 1st digit decreased to 1.4 and 10.1%, respectively. Nontreated Pdn/Pdn fetuses exhibited preaxial polydactyly of the duplicated or triplicated metacarpal/metatarsal type both in the fore- and hindlimbs. In the treated Pdn/Pdn fetuses, the number of preaxial extra digits decreased in both limbs. Some hindlimbs of the treated Pdn/Pdn fetuses exhibited five metatarsals, normally. In the vitally stained specimens at 6 and 24 hours after injection of Ara-C, preaxial marginal necrotic zones (fMI) were observed in almost all of the treated embryos from +/+ x Pdn/+ matings. However, approximately half of the embryos did not exhibit fMI in the nontreated control group at the same stage. Those embryos deficient in fMI were regarded as Pdn/+. These findings indicated that a subteratogenic dose of Ara-C prevented the genetic expression of polydactyly in almost all Pdn/+ and some cases of Pdn/Pdn mice.(ABSTRACT TRUNCATED AT 250 WORDS)     

Biomechanical implications of lumbar spinal ligament transection

Many lumbar spine surgeries either intentionally or inadvertently damage or transect spinal ligaments. The purpose of this work was to quantify the previously unknown biomechanical consequences of isolated spinal ligament transection on the remaining spinal ligaments (stress transfer), vertebrae (bone remodelling stimulus) and intervertebral discs (disc pressure) of the lumbar spine. A finite element model of the full lumbar spine was developed and validated against experimental data and tested in the primary modes of spinal motion in the intact condition. Once a ligament was removed, stress increased in the remaining spinal ligaments and changes occurred in vertebral strain energy, but disc pressure remained similar. All major biomechanical changes occurred at the same spinal level as the transected ligament, with minor changes at adjacent levels. This work demonstrates that iatrogenic damage to spinal ligaments disturbs the load sharing within the spinal ligament network and may induce significant clinically relevant changes in the spinal motion segment.     

Treatment of osteoporosis with human parathyroid peptide and observations on effect of sodium fluoride.

OBJECTIVE--To evaluate the need for a randomised study of treatment of spinal osteoporosis with human parathyroid peptide in the secondary prevention of crush fractures; to study the effect of human parathyroid hormone peptide 1-34 plus sex hormones on vertebral body cancellous bone; and, separately, to determine the effect of relatively low doses of sodium fluoride plus calcium on spinal bone mineral density. DESIGN--Open study of patients with primary or postmenopausal osteoporosis. All patients had serial bone densitometry of the spine by quantitative computed tomography and dual photon absorptiometry as well as serial densitometry of the radial midshaft (cortical) and radial distal (trabecular) bone by quantitative computed tomography. Changes in the spinal bone not forming the spongiosa of the vertebral bodies ("cortical" bone) were determined from the difference between the two axial measurements, after correction to the same units of measurement. SETTING--Northwick Park Hospital and Medical Research Council Clinical Research Centre. PATIENTS--24 Patients who fulfilled the conventional criteria for type 1 (vertebral) osteoporosis not secondary to recognised causes other than sex hormone deficiency and with at least one crush or wedge vertebral fracture and a spinal bone density (quantitative computed tomography) less than 80 mg/cm3 or two or more fractures. Twelve patients received human parathyroid peptide and 12 sodium fluoride; they were not randomised. MAIN OUTCOME MEASURES--Trends in axial and peripheral bone mass values determined by linear, time dependent regression analyses. RESULTS--The patients receiving the peptide showed a substantial increase in vertebral spongiosa (mean 25.6 mg/cm2 two years after the start of treatment). No significant changes were seen in spinal cortical or radial bone density. The patients receiving sodium fluoride showed roughly equal increases in cancellous and cortical bone over the same period (mean increase in vertebral spongiosa 16.1 mg/cm3). No significant changes were seen in radial bone. CONCLUSIONS--Treatment of postmenopausal women with human parathyroid peptide selectively increases spinal cancellous bone density by amounts that may prove useful in secondary prevention. Peptide treatment should now be tested in a randomised study in which the important end point is prevention of fractures as the usefulness of sodium fluoride in this context is doubtful.     

The morphogenesis of myeloschisis in the rat

Pregnant Sprague-Dawley rats were utilized in this study. They were separated into two groups. In the control group, a single intragastric dose of distilled water was given on the 11th day of gestation. In the test group, a single intragastric dose of ethylenethiourea (ETU), 240 mg/kg was given on the same day of gestation. Embryos were recovered 12, 24, 36, and 48 hours after ETU and distilled water administration, and were prepared for scanning electron microscopy and light microscopy. The posterior neuropore of rat fetuses in the control group closed completely on gestation day 12.5. However, the closure of posterior neuropore in ETU-induced fetuses is shown to have been disrupted 12 hours after ETU administration. Marked neural tissue overgrowth in the posterior neuropore resulted in neural fold eversion and finally produced a picture of lumbosacral myeloschisis on day 13 of gestation. Our observation implies that myeloschisis is induced by non-closure of the neural fold, not by reopening after its proper closure.     

脊柱跳跃型骨折的临床研究进展

脊柱跳跃型骨折指多节段非相邻的椎体骨折(multiple-level noncontiguous spinal fractures,MNSF)。对于非高龄患者,此类骨折通常为暴力性高能量损伤。由于MNSF受伤机制的复杂性,患者的临床表现不尽相同,导致其常发生漏诊或延迟诊断。目前,临床上对于MNSF发病率和损伤原因有很多报道,特别是其致伤机制,也存在很多理论。脊柱跳跃性骨折的治疗需全面考虑,如脊柱的不稳定性、畸形和骨折节段之间正常的椎体数目甚至患者想要减少住院时间的要求等。治疗时应按照各自损伤部位的情况决定治疗方案,强调个体化治疗。需要手术治疗的患者应依据其损伤特点选择相应术式,重建脊柱稳定性。本文主要就近年来MNSF的临床研究进展了进行总结,旨在为MNSF的临床诊疗提供参考。     

Ovarian follicular cell hyperplasia in fetal mice treated transplacentally with ethinyl estradiol

The occurrence of follicular cell hyperplasia was studied by light and electron microscopy in fetal mouse ovaries exposed to ethinyl estradiol (EE) from day 11 through day 17 of pregnancy. Pregnant mice were given EE in olive oil (0.02, or 0.2 mg/kg of body weight) and were sacrificed on day 18. The female fetuses were examined for ovarian histogenesis. Follicular cell hyperplasia was detected in both of the experimental groups, but the incidence was statistically significant only in fetuses exposed to 0.2 mg/kg of EE. Light and electron microscopic observations of the ovaries showed that the hyperplasia was located in the medullary region, and the follicular cells showed pleomorphism. Accumulation of abundant lipid droplets, enlarged rough endoplasmic reticulum with granular material, dense bodies, and vague masses of fibrous structures were seen in the cytoplasm. These morphological observations indicate that hyperplasia of follicular cells in fetal mouse ovaries at term can be induced by prenatal treatment with EE.     

Prevalence of vertebral compression fractures due to osteoporosis in ankylosing spondylitis.

OBJECTIVE--To determine the prevalence of vertebral compression fractures due to osteoporosis in patients with ankylosing spondylitis. DESIGN--Prospective study of 111 consecutive patients; patients with vertebral compression fractures were entered into a case-control study. SETTING--Outpatient clinic at the centre for rheumatic diseases, Glasgow. PATIENTS--111 Consecutive patients with ankylosing spondylitis. Patients with compression fractures were matched for age and sex with two controls selected from the rest of the group. Patients with biconcave vertebral fractures were also studied. MAIN OUTCOME MEASURES--Assessments of spinal deformity and mobility and analysis of lateral radiographs of spines for presence of syndesmophytes. RESULTS--Fifteen patients with compression fractures and five with biconcave fractures were studied. Compared with the controls the patients with compression fractures had increased formation of syndesmophytes in the lumbar spine, whereas those with biconcave fractures had increased formation throughout the spine. Patients with compression fractures also had a greater degree of spinal deformity (distance from wall to tragus 24.5 cm v 12.7 cm in controls), less spinal mobility (20 v 45.6 degrees of flexion), and reduced chest expansion (2 cm v 3cm). CONCLUSION--Vertebral compression fractures due to osteoporosis are a common but frequently unrecognised complication of ankylosing spondylitis and may contribute to the pathogenesis of spinal deformity and back pain.     

Role of the wheelchair in the management of the muscular dystrophy patient.

During the postambulatory period, patients with pseudohypertrophic muscular dystrophy depend entirely on their wheelchairs for comfort and spinal support. Without the comfort they are unable to enjoy and participate in every waking activity; without the spinal support they are destined to accept a bedbound life, not so much by the actual weakness as by the progression of spinal deformity. Present-day wheelchairs are not comfortable and they do not provide adequate spinal support. A novel spinal support system (brace) has been prescribed for 50 patients during the last 24 months. It consists of a contoured seat, mounted on a modified wheelchair frame, with integral armrests, footrests and headrest. All patients are clearly more comfortable and spend between 9 and 14 hours a day in their special wheelchairs, compared with 2 to 3 hours at a time in standard wheelchairs. Parents, teachers and therapists have reported a definite improvement in the attitudes of these patients. Although we have measured no progression in spinal deformity and have recorded regression in a few patients, we cannot yet assess the final value of this promising method of support in preventing spinal collapse.     

Ontogeny of substance P in the digestive tract, spinal cord and hypothalamus of the human fetus

The time of appearance and tissue concentrations of substance P-like immunoreactivity (SP-LI) were studied in 53 human fetuses aged 8-21 weeks. Detectable amounts were present at 8 weeks of gestation in available fragments of spinal cord and intestine. Thereafter, the tissue concentrations were highest in spinal cord, intermediate in hypothalamus and lowest in digestive tract. Except for a significant increase in the intestinal wall, the concentrations did not vary from the 8-14 to the 15-21 week period. At chromatography, SP-LI in extracts of spinal cord and intestine was essentially eluted in the volume of the synthetic undecapeptide. Using the indirect immunofluorescence technique, the localization of SP-LI positive structures in the digestive tract was studied in 5 fetuses aged 12-18 weeks. Scarce cell bodies were observed in the myenteric plexus. Nerve fibers were recognized in the muscular layer, in the myenteric plexus and in connective tissue of pancreas. The present results demonstrate the early appearance of SP-LI positive structures both in central nervous system and in the enteric nervous system in the human fetus. In the age range tested, SP-LI concentrations were noticeably higher in spinal cord and hypothalamus than in the digestive tract.     

Glycerinated catch apparatus of sea urchin spines: the effects of cations on its mechanical properties and ultrastructure

Sea urchin spinal ligaments (the catch apparatus) were extracted with glycerin, and electron microscopic observations comfirmed that no cell membranes remained intact after glycerination. We studied the effects of cations (Na(+), K(+), Ca(2+), Mg(2+)) on the mechanical properties of the glycerinated ligaments. Monovalent cations decreased whereas divalent cations increased the viscosity of the ligaments. The ion dependencies were similar to previous results with detergent-extracted holothurian dermis, which suggests that the echinoid ligament shares a similar mechanism for changes in mechanical properties with other catch connective tissues. This provides evidence against the hypothesis of that muscles in the catch apparatus are responsible for the changes in mechanical properties of the ligament. Fine projections cross-bridging collagen fibrils were observed in the glycerin-extracted ligaments as well as in the intact ligaments. They were found in all the ionic conditions studied.     

The arterial supply of the cervical vertebral body in newborns

The cervical vertebral column is mainly supplied by both vertebral arteries. A regular ladder pattern of arteries is on the dorsal plane as well as on the ventral plane of the cervical vertebral bodies, opposite to the thoracal and the lumbar area of the vertebral column with only a dorsal ladder pattern of arteries. The cervical arterial anastomoses are built by the segmental arteries of the vertebral arteries, in the back of the cervical vertebral bodies by the arteriae canalis vertebralis anteriores and in the front by the rami anteriores (corporum vertebrarum). The thyrocervical and the costocervical trunks are an additional blood supply especially to the ventral anastomoses. A loss of a segmental artery may have no effect because of the good anastomoses. Some decades of aa. nutriciae come in the vertebral body from all sides, but only 2 up to 4 rr. centrales anteriores and 2 rr. centrales posteriores join in the middle of the vertebral body. There are parallels to the arterial blood supply of the thoracal and the lumbar vertebral bodies. The longitudinal ligaments are supplied by both ladder patterns of arteries.     

The relationship of whole human vertebral body creep to geometric,microstructural, and material properties

Creep, the time dependent deformation of a structure under load, is an important viscoelastic property of bone and may play a role in the development of permanent deformity of the vertebrae in vivo leading to clinically observable spinal fractures. To date, creep properties and their relationship to geometric, microstructural, and material properties have not been described in isolated human vertebral bodies. In this study, a range of image-based measures of vertebral bone geometry, bone mass, microarchitecture and mineralization were examined in multiple regression models in an effort to understand their contribution to creep behavior. Several variables, such as measures of mineralization heterogeneity, average bone density, and connectivity density persistently appeared as significant effects in multiple regression models (adjusted r²: 0.17–0.56). Although further work is needed to identify additional tissue properties to fully describe the portion of variability not explained by these models, these data are expected to help understand mechanisms underlying creep and improve prediction of vertebral deformities that eventually progress to a clinically observable fracture.     

Comparative development of thoracic intervertebral discs and intra-articular ligaments in the human, monkey, mouse, and cat

Developmental features of thoracic intervertrebral discs and their association in the adult with other vertebral structures were investigated in four species. The human anulus fibrosus, nucleus pulposus, and intra-articular ligaments were compared to those of the fetal rhesus monkey, mouse, and kitten. Photomicrographs of transverse sections of intervertebral discs document the presence of intra-articular ligaments in fetuses of these four species. Both transverse and sagittal sections of kittens were used to identify the intercapital ligament as it differentiated from the dorsal part of the intra-articular ligament. Relatively frequent dorsal herniation of the thoracic nucleus pulposus in humans may be due to the vestigial nature of the human intra-articular ligament. Quadrupeds have well-developed intra-articular ligaments, which explains anatomically the paucity of dorsal protrusions of the nucleus pulposus into the vertebral canal in the thoracic region of the cat and mouse when compared to the human. The intra-articular ligament was closely associated with the developing prenatal mammalian intervertebral disc in the four species studied, and this relationship and its surgical importance are described.     

棉铃虫幼虫小网膜细胞对光暗的反应

用透射电镜观察了棉铃虫Heliothis armigers(Hübnner)5龄幼虫小网膜细胞内一些细胞器的昼夜变化.其中色素颗粒,内质网,多泡体和多片层体变化特别显著.天亮3小时后,细胞内出现大量多泡体,多片层体和形态介于两者之间的细胞器.它们的数量随光照时间的延长而下降.天亮10小时后,大部分在细胞内消失.从天黑后2小时至天亮前2小时的细胞内含有大量的由滑而内质网构成的髓样体.天亮后它们在细胞内消失.昼夜交替还导致细胞内屏蔽色素颗粒周期性的水平和垂直移动.结合现有资料,我们对上述现象的意义进行了探讨.