Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Vertebrates”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources

Relevance of bone mineral density, bone quality and falls in reduction of vertebral and non-vertebral fractures.

All epidemiological studies conclude that without prompt, concerted and well-designed prevention programs, the increasing cost related to osteoporotic fractures will become an unbearable burden for the community within the next fifteen years. However, the most effective way of setting up such preventive strategies is not yet unequivocally defined. Low bone mass and microarchitectural damage of bone tissue may account for a large part of the epidemiology of vertebral fractures. Extraskeletal determinants, including low muscle strength, poor balance and gait, all resulting in an increased propensity to fall, also play a major role in the occurrence of hip fracture. Depending on the localization of the fractures, the relative importance of skeletal and extraskeletal risk factors can significantly differ. For prevention of vertebral fractures, drugs affecting bone mass and skeletal architecture may provide a substantial benefit while hip fracture prevention will be more successfully targeted by multi-faceted strategies concentrating not only on the skeletal dimension of the fracture but also aiming, either pharmacologically or through multi-intervention programs, at a reduction in the incidence and in the consequences of falls in the elderly.

Journal Article↗

Current status of percutaneous vertebral augmentation techniques for vertebral compression fractures.

Vertebral compression fracture (VCF) is a common and debilitating problem that occurs in patients with osteoporosis and osteolytic tumors. Standard conservative management with narcotic analgesics, bracing, and immobilization is often ineffective, and major reconstructive surgery is poorly tolerated by this frail patient population. The limitations of conventional treatments stimulated the development of minimally invasive, percutaneous vertebral augmentation techniques, including vertebroplasty and kyphoplasty, which have become established as safe and effective treatments for VCF. This report reviews the current status of vertebroplasty and kyphoplasty in the management of acute VCF.

Fracture Fixation, Internal↗

Left-right upper arm length asymmetry associated with apical vertebral rotation in subjects with thoracic scoliosis: anomaly of bilateral symmetry affecting vertebral, costal and upper arm physes?

Left-right skeletal length asymmetries in upper limbs related to curve side and severity have been detected with adolescent idiopathic scoliosis (AIS). This paper reports upper arm length asymmetry in thoracic scoliosis related significantly to apical vertebral rotation in school screening referrals. The reason(s) for the association of upper arm length asymmetry with apical vertebral rotation is unknown and three factors are considered: (1) neuromuscular mechanisms from primary or secondary causes, (2) relative concave neurocentral synchondrosis overgrowth, and (3) relative concave periapical rib length overgrowth, A putative anomaly of growth plates (physes) of ribs, neurocentral synchondroses and upper arms, would account for the findings. A solution to this dilemma may emerge from the results of surgery should concave periapical rib resections become evaluated further for right thoracic AIS in girls.

Adolescent↗

[State of the vertebral canal in vertebral and spinal cord injuries].

The results of the analysis of 128 patients who had died after trauma of the spine and spinal cord are discussed. Total disturbance of the anatomical intactness of the vertebral canal walls was demonstrated on all specimens. In 85% of patients there were fractures with or without displacement of the injured vertebra; 15% of patients had suffered injury only to the ligamentous-capsular apparatus, the disk included, with no displacement--dislocation of the vertebra. The shape of the vertebral canal was distorted only in cases with displacement of the vertebra. The area of the canal was reduced to almost half the size demonstrated on the radiograms.

Fractures, Bone↗

[Gas dissection of the vertebral body or the vertebral intrasomatic space phenomenon. Physiopathological arguments].

Some features concerning the ischemic origin of the gaseous dissection of the vertebral body and the physiopathology of the necrose, are considered in the adult: --in the way, the anterior topography of vaccum phenomenon is on the model of the arterial distribution in the vertebral body, implying ischemic origin of gaseous dissection; --further, two cases of intravertebral vaccum cleft, noticed after minor trauma, suggest the major role of fractures at the origin of ischemia.

Aged↗

Treatment of vertebral artery aneurysms with transposition of the posterior inferior cerebellar artery to the vertebral artery combined with parent artery occlusion. Technical note.

The authors describe transposition of the posterior inferior cerebellar artery (PICA) to the vertebral artery (VA) combined with parent artery occlusion for the treatment of VA aneurysms in cases in which a clip could not be applied because of the origin of the ipsilateral PICA. The aneurysm is trapped through a lower lateral suboccipital craniectomy. The PICA is then cut just distal to the aneurysm, and the PICA and VA proximal to the aneurysm are anastomosed in an end-to-end or end-to-side fashion. The surgical procedure was successfully performed in two patients, each of whom had hypoplastic occipital arteries (OAs). The PICA contralateral to the lesion was hypoplastic in one patient and distant to the ipsilateral PICA in the other patient. Mild transient dysphagia developed postoperatively in one patient due to glossopharyngeal and vagus nerve palsy, and the other patient had an uneventful postoperative course. In both patients, postoperative cerebral angiography demonstrated good patency of the transposed PICA. These results show that transposition of the PICA to the VA is a useful procedure for the reconstruction of the PICA when parent artery occlusion is necessary to exclude a VA aneurysm involving the origin of the PICA and when OA-PICA anastomosis or PICA-PICA anastomosis cannot be performed.

Adult↗

Tempo and mode of mitochondrial DNA evolution in vertebrates at the amino acid sequence level: rapid evolution in warm-blooded vertebrates.

By using complete sequence data of mitochondrial DNAs, three Markov models (Dayhoff, Proportional, and Poisson models) for amino acid substitutions during evolution were applied in maximum likelihood analyses of mitochondrially encoded proteins to estimate a phylogenetic tree depicting human, cow, whale, and murids (mouse and rat), with chicken, frog, and carp as outgroups. A cow/whale clade was confirmed with a more than 99.8% confidence level by any of the three models, but the branching order among human, murids, and the cow/whale clade remained uncertain. It turned out that the Dayhoff model is by far the most appropriate model among the alternatives in approximating the amino acid substitutions of mitochondrially encoded proteins, which is consistent with a previous analysis of a more limited data set. It was shown that the substitution rate of mitochondrially encoded proteins has increased in the order of fishes, amphibians, birds, and mammals and that the rate in mammals is at least six times, probably an order of magnitude, higher than that in fishes. The higher evolutionary rate in birds and mammals than in amphibians and fishes was attributed to relaxation of selective constraints operating on proteins in warm-blooded vertebrates and to high mutation rate of bird and mammalian mitochondrial DNAs.

Amino Acid Sequence↗

Distal ligation and revascularization from external carotid to vertebral artery with radial artery graft for treatment of extracranial vertebral artery dissection. Report of a case.

We present a case of dissection of the extracranial vertebral artery with prominent occipital pain and elements of the lateral medullary syndrome. Arteriography showed a string and pearl sign. Magnetic resonance imaging allowed visualization of an intramural thrombus associated with a narrow vascular lumen. The distal portion of the diseased artery was ligated and vascular reconstruction using an interposed radial artery graft was performed. Pathological studies confirmed the diagnosis. The diagnostic roles of angiography and magnetic resonance imaging, and therapeutic strategies are discussed.

Adult↗

Development of a dissecting aneurysm on the vertebral artery immediately after occlusion of the contralateral vertebral artery: a case report.

A 49 year old female presented with subarachnoid hemorrhage due to a ruptured dissecting aneurysm on the left vertebral artery (VA). Following an occlusion test, we performed proximal occlusion of the left VA with detachable balloons. However, a dissecting aneurysm on the right VA developed three weeks later. After an occlusion test had showed no change in cerebral blood flow, auditory brain stem response, or neurological status, proximal occlusion of the right VA was performed. The patient has returned to normal life without neurological deficits. Bilateral dissecting aneurysms of the VA are quite common, but de novo VA dissecting aneurysms or enlargement of such aneurysms after occlusion of contralateral VA are rare. This case suggests that hemodynamics stress may be a causal factor in the development of VA dissecting aneurysms. Careful pre- and post-operative neuroradiological examination of the contralateral VA are required in patients undergoing VA occlusion for dissecting aneurysms.

Aortic Dissection↗

Ischemic symptoms induced by occlusion of the unilateral vertebral artery with head rotation together with contralateral vertebral artery dissection--case report.

We report a 45-year-old woman whose unilateral vertebral artery (VA) was potentially occluded with head rotation at the C1-C2 level and her ischemic symptoms suddenly appeared because of contralateral VA dissection. She noticed first pain around the posterior part of her neck on the right side, and then dizziness when turning the head to the right side. The dizziness disappeared immediately after her head returned to the natural position. Digital subtraction angiography (DSA) showed a string sign of the right VA. DSA and computed tomography angiography (CTA) showed high grade extrinsic compression of the left VA at the C1-C2 level with head rotation more than 90 degrees to the right. Three-dimensional (3D) CTA also showed clearly kinking of the left VA at the C2 neuroforamina. Her symptoms disappeared completely with conservative therapy, and recanalization of the right VA was also confirmed by 3D-CTA. 3D-CTA was thought to be valuable to diagnose and manage the rotational compression of the artery. VA dissection must be remembered to differentially diagnose the etiology of transient attacks of posterior circulation ischemia due to rotational contralateral VA occlusion.

Angiography↗

Pathogenesis of uncus deformation and vertebral artery compression: histologic investigations of the uncus and dynamic angiography of the vertebral artery in the cadaveric cervical spine.

Twenty-one cervical spines were collected from fresh cadavers (12 male, nine female), their ages ranging from 10 to 90 years (mean 49.47). After removing muscle debris from the spines, they were mounted and tested on a device to passively reproduce the main movements of the spine. The degree of motion in flexion-extension and lateral bending significantly decreased from group A (ages 10-49 years) to group B (51-90 years) (p < 0.005) and was directly correlated with the amount of cervical spine degenerative alterations. The incidence of these alterations, classified according to Lysell (1969), was highest at C5-6. On the testing machine, dynamic angiography of the vertebral artery showed an impingement with extrinsic compression of the vessels in four of 28 successful injections. The histologic serial sections of the uncus showed a characteristic pattern of ossification-deformation: a newly formed cartilaginous tissue tipping the apex of the uncus, forming a double protruding contour of the apex, rapidly ossifying, and appearing to deform outward together with the disk degeneration and consequently decreasing in height.

Adolescent↗

Treatment of a partially thrombosed giant aneurysm of the vertebral artery by aneurysm trapping and direct vertebral artery-posterior inferior cerebellar artery end-to-end anastomosis: technical case report.

OBJECTIVE: The purpose of this article is to focus for the first time on the operative management of a direct vertebral artery (VA)-posterior inferior cerebellar artery (PICA) end-to-end anastomosis in a partially thrombosed giant VA-PICA-complex aneurysm and to underline its usefulness as an additional treatment option. METHODS: The operative technique of a direct VA-PICA end-to-end anatomosis is described in detail. The VA was entering the large aneurysm sack. Distally, the PICA originated from the aneurysm sack-VA-complex. The donor and recipient vessel were cut close to the aneurysm. Whereas the VA was cut in a straight manner, the PICA was cut at an oblique 45-degree angle to enlarge the vascular end diameter. Vessel ends were flushed with heparinized saline and sutured. The thrombotic material inside the aneurysm sack was removed and the distal VA clipped, leaving the anterior spinal artery and brainstem perforators free. RESULTS: The patient regained consciousness without additional morbidity. Magnetic resonance imaging scans revealed a completely decompressed brainstem without infarction. The postoperative angiograms demonstrated a good filling of the anastomosed PICA. CONCLUSION: Despite the caliber mistmatch of these two vessels the direct VA-PICA end-to-end anastomosis provides an accurate alternative in addition to other anastomoses and bypass techniques, when donor and recipient vessels are suitable and medullary perforators do not have to be disrupted.

Aged↗

Hemifacial spasm due to compression of the facial nerve by vertebral artery-posterior inferior cerebellar artery aneurysm and elongated vertebral artery--case report.

A 62-year-old female presented with rapid aggravation of long-standing facial spasm occurring within a few months. Neuroimaging and angiography demonstrated compression of the root exit zone (REZ) of the facial nerve by an ipsilateral saccular aneurysm at the left vertebral artery (VA)-posterior inferior cerebellar artery bifurcation, in addition to the elongated VA. Neck clipping of the aneurysm and decompression of the REZ from the elongated VA and clipped aneurysm resulted in complete disappearance of the facial spasm. The aneurysm had very thin walls and was apparently about to rupture. Aggravation of long-standing hemifacial spasm may be a warning sign for rapid growth and rupture of a causative aneurysm.

Facial Nerve Diseases↗

Surgical possibilities in the third portion of the vertebral artery (above C2). Anatomical study and report of a case of anastomosis between subclavian artery and vertebral artery at C1-C2 level.

A reappraisal of surgical possibilities in the third portion of the vertebral artery (VA) above C2, has been done from an anatomical study on twenty autopsy specimens. A route passing between the internal jugular vein and the Sterno-cleido-mastoid muscle allows a simple approach to the transverse process of C1. After division of two muscles attached to this process, 1.5 cm of the VA can be exposed. For larger exposure of the artery, the foramen transversarium of C1 must be unroofed and the artery dissected in the guttering of the posterior arch of the atlas. This surgical route was used in a case of aneurysmal dysplasia at the C3 level. An anastomosis between the subclavian artery and VA at the C1-C2 level was performed with an autologous saphenous vein graft. The key points are the highest possible freeing of the XI nerve and the head position. Rotation and extension move the transverse process and the posterior arch of the atlas superficially and anteriorly.

Cerebral Revascularization↗

New X-ray diffraction observations on vertebrate muscle: organisation of C-protein (MyBP-C) and troponin and evidence for unknown structures in the vertebrate A-band.

Previous low-angle X-ray diffraction studies of various vertebrate skeletal muscles have shown the presence of two rich layer-line patterns, one from the myosin heads and based on a 429 A axial repeat, and one from actin filaments and based on a repeat of about 360-370 A. In addition, meridional intensities have been seen from C-protein (MyBP-C; at about 440 A and its higher orders) and troponin (at about 385 A and its orders). Using preparations of intact, relaxed, bony fish fin muscles and the ID-02 low-angle X-ray camera at the ESRF with a 10 m camera length we have now seen numerous, hitherto unreported, sampled, X-ray layer-lines many of which do not fit onto the previously observed repeats and which require interpretation. The new reflections all fall on the normal ("vertical") hexagonal lattice row-lines in the highly sampled, almost "crystalline", low-angle diffraction X-ray patterns from bony fish muscle, indicating that they all arise from the muscle A-band. However, they do not fall on a single axial repeat. In direct confirmation of our previous analysis, some of these new reflections are explained by the interaction in resting muscle between the N-terminal ends of myosin-bound C-protein molecules with adjacent actin filaments, possibly through the Pro-Ala-rich region. Other newly observed reflections lie on a much longer repeat, but they are most easily interpreted in terms of the arrangement of troponin on the actin filaments. If this is so, then the implication is that the actin filaments and their troponin complexes are systematically arranged in the fish muscle A-band lattice relative to the myosin head positions, and that these newly observed X-ray reflections, when fully analysed, will report on the shape and distribution of troponin molecules in the resting muscle A-band. The less certain contributions of titin and nebulin to these new reflections have also been tested and are described. Many of the new reflections do not appear to come from these known structures. There must be structural features of the A-band that have not yet been described.

Animals↗

[Color-coded duplex ultrasound of the vertebral artery: normal findings and pathologic findings in obstruction of the vertebral artery and remaining cerebral arteries].

AIM: The aim of this study was to determine normal values of flow velocities in the extracranial vertebral artery (VA) with regard to diameter of the VA, blood pressure and age. Hemodynamic changes in the VA in occlusive disease of the brain supplying arteries were also to be investigated. Based on the findings the clinical value of CCDS for the investigation of the VA were to be assessed. METHOD: The evaluation was carried out by a CCDS-scanner with a 7.5 MHz transducer in 85 normal individuals and in 166 patients with occlusive disease of the cerebral arteries. RESULTS: The average maximal systolic flow velocity was 59 +/- 17, time averaged maximal velocity 31 +/- 10 and enddiastolic velocity 19 +/- 8 cm/sec. Significantly reduced flow velocities were found in severely stenosed and in occluded VA increased flow velocities in VA serving as collateral pathway in higher grade obstructions of contralateral VA, ICA, and SCA. CONCLUSION: CCDS of the VA is a valuable tool in diagnosis of severe obstructions of the VA, but also for demonstration of collateral flow. Furthermore, cervical collateral pathways in severe obstruction of the VA-origin can be detected. Diagnosis of moderate stenosis of the ostium of the VA remains difficult.

Adolescent↗

Smoking and the human vertebral column: a review of the impact of cigarette use on vertebral bone metabolism and spinal fusion.

Chronic cigarette consumption has significant adverse effects on the human spinal column. Multiple mechanisms induced by tobacco use lead to less strong, less healthy, mineral-deficient vertebrae with reduced bone blood supply and fewer and less functional bone-forming cells among chronic smokers. Compared to nonsmokers, chronic smokers develop advanced bony degradation, are more likely to suffer from spinal column degenerative disease, and seem more susceptible to traumatic vertebral injury. Spinal fusion procedures in chronic smokers are less often clinically and radiographically successful, compared to similar procedures performed among nonsmokers for definitive biological, physiological, and mechanical reasons.

Animals↗