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At least 199 records · Page 11Linked to original sources
PubMed2004

Vertebral forward slippage in immature lumbar spine occurs following epiphyseal separation and its occurrence is unrelated to disc degeneration: is the pediatric spondylolisthesis a physis stress fracture of vertebral body?

STUDY DESIGN: Radiographic and histologic evaluation of a rat model of lumbar spine slippage. OBJECTIVES: To clarify the pathomechanism of slippage in the immature spine. SUMMARY OF BACKGROUND DATA: There are controversial hypotheses regarding the pathogenesis of slippage of the pediatric spine with pars defects. Some studies supported that disc degeneration was its cause, while others indicated the growth plate injury was the cause. METHODS: An immature lumbar spine slippage model in 4-week-old rats was used. Following posterior destabilizing surgery, the lumbar spine was radiographically and histologically examined at 1, 3, 5, and 7 days after surgery. RESULTS: Radiographically, slippage occurred about 7% in the % slip on day 7, and no slippage was observed before day 5. Histologically, epiphyseal separation also appeared on day 7; before day 5, the growth plate showed no abnormalities. Within 7 days after the operation, the anulus fibrosus did not show any sign indicating degeneration. The nucleus pulposus was also normal up to day 7. CONCLUSION: The findings of this study support the hypothesis that vertebral forward slippage of the immature spine occurs following epiphyseal separation and its occurrence is unrelated to disc degeneration.

Animals↗
PubMed1977

Toxoplasma gondii-vertebrate cell interactions. I. The influence of bicarbonate ion, CO2, pH and host cell culture age on the invasion of vertebrate cells in vitro.

A controlled-environment culture system was used to show that both physical and biologic parameters can influence the penetration of vertebrate cells by Toxoplasma gondii. The optimum bicarbonate ion concentration for the penetration of bovine embryo skeletal muscle (BESM) cells is 36.25 mM. Higher or lower bicarbonate ion concentrations are increasingly inhibitory to penetration. As CO2 increases in the range from 0.5-3.7 mM, penetration is progressively inhibited. No relationship was found between penetration and pH in the pH range of 6.949-7.765. The culture age of the BESM cells directly influenced the ability of the parasites to penetrate the cells. Older BESM cells were more refractory to penetration than younger cells.

Animals↗
PubMed1995

tinman, a Drosophila homeobox gene required for heart and visceral mesoderm specification, may be represented by a family of genes in vertebrates: XNkx-2.3, a second vertebrate homologue of tinman.

tinman is a Drosophila Nk-homeobox gene required for heart and visceral mesoderm specification. Mutations in tinman result in lack of formation of the Drosophila heart, the dorsal vessel. We have isolated an Nk-homeobox gene from Xenopus laevis, XNkx-2.3, which appears by sequence homology and expression pattern to be a homologue of tinman. The expression pattern of XNKx-2.3 both during development and in adult tissues partially overlaps with that of another tinman homologue, Csx/NKx-2.5/XNkx-2.5. We have found that embryonic expression of both XNkx-2.3 and XNkx-2.5 is induced at a time when cardiac specification is occurring. XNkx-2.3 is expressed in early cardiac primordia before the expression of a marker of cardiac differentiation. XMLC2, as well as in pharyngeal endoderm. In adult tissues, XNkx-2.3 is expressed in the heart and several visceral organs. As the helix-loop-helix factor Twist is thought to regulate tinman expression in Drosophila, we have compared the expression of XNkx-2.3 and Xtwist during embryonic development in Xenopus. There appears to be no overlap in expression patterns of the two RNAs from the neurulae stages onward, the first time at which the RNAs can be visualized by in situ hybridization. The overlapping expression patterns of XNkx-2.3 and mNkx-2.5/XNkx-2.5 in conjunction with evidence presented here that other Nk-homeodomains are expressed in adult mouse and Xenopus heart suggests that tinman may be represented by a family of genes in vertebrates.

Alleles↗
PubMed2003

[Bisphosphonates in the prevention of vertebral and non-vertebral fractures in postmenopausal women with osteoporosis].

Bisphosphonates (risedronate and alendronate) inhibit bone resorption, increase bone mass and reduce the risk of vertebral and nonvertebral fractures in postmenopausal women as has been shown in a number of clinical trials. The concept of bone quality has recently been actualized with evidence that antiresorptive drugs reduce the occurrence of fractures to a greater extent than would be predicted by the amount of the increase in bone density. Concern about possible negative effect on fracture resistance with prolonged treatment with bisphosphonates has no evidence from clinical studies. Both preclinical and clinical studies, histologically and biomechanically performed, have revealed normal quality of bone formed during treatment with bisphosphonates.

Alendronate↗
PubMed2006

Acute vertebral compression fractures in patients with multiple myeloma: evaluation of vertebral body edema patterns on MR imaging and the implications for vertebroplasty.

The presence of edema on MR imaging is a common finding in acute or subacute vertebral body compression fractures. Compression fractures can present in patients with benign osteoporosis, metastases, multiple myeloma, or hemangiomas. We present 2 patients with multiple myeloma who had symptomatic acute and subacute compression fractures documented on imaging studies without associated edema on MR imaging evaluation.

Bone Cements↗
PubMed1986

The clonal model of vertebral column development: a reinvestigation of vertebral shape using Fourier analysis.

Little work has been done on the skeletal system of allophenic mice (chimaeras). In this paper we re-examine the evidence presented for the clonal theory of vertebral development using quantitative methods which take account of variation. We conclude that the clonal theory is either an overly simplistic approximation of the real situation, or that the evidence so far given in its support is unsubstantiated.

Animals↗
PubMed1983

Sagittal movements of the human lumbar vertebral column: a quantitative study of the role of the posterior vertebral elements.

The influence of the posterior vertebral ligamentous and bony elements on the sagittal range of motion of the lumbar spine has been investigated by observing the effects of sectioning ligaments and pedicles in 17 cadavers of both sexes with an age range from 14 to 78 years. The main investigation showed that the apophyseal joints provide a greater restraint to flexion and extension movements than do the lumbar ligaments. It also showed that the age changes which most severely affect movement in elderly persons occur in the intervertebral discs rather than in the posterior elements.

Adolescent↗