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.

SourceResearch connectionFrom yearThrough year

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

At least 91 records · Page 5Linked to original sources

PubMed1975

Contribution to the clinical anatomy of the vertebral column. Considerations on the stability and the instability at the height of the "vertebral units".

Based on the findings with human cadaver material and the literature data, the concept of "vertebral unit" is discussed as a basic morphofunctional and pathogenic unit of the vertebral column. The vertebral structures collaborating to the stabilization of the vertebral units are described and a review is made of the possibilities of installation of a vertebral instability. An attempt is made to define the vertebral stability and instability.

Biomechanical Phenomena↗

PubMed1997

Spatial distribution of postotic crest cells defines the head/trunk interface of the vertebrate body: embryological interpretation of peripheral nerve morphology and evolution of the vertebrate head.

The migration pathways and spatial distribution of neural crest cells largely depend on the embryonic architecture. At the preotic level in the chick embryo, cephalic crest adhere to even-numbered rhombomeres proximally, and populate each pharyngeal arch distally, thus prefiguring the morphology of the branchiomeric nerves. This distribution pattern is possible because of the absence of somites in the head. In the postotic region, however, somites and pharyngeal arches coexist at the same axial level. The caudalmost cephalic crest cell population, the circumpharyngeal crest cells, are derived from the postotic crest and their distribution covers the entire innervation areas of cranial nerves IX and X. In their proximal migration pathway, circumpharyngeal crest cells can exist along the dorsolateral pathway only where somites are absent. They divert around the occipital somites rostrally, making an arc that represents the caudal limit of the dorsolateral pathway of cephalic crest cells, or the head/trunk interface at the paraxial level. Ventrally, the circumpharyngeal crest cells localize in postotic pharyngeal arches as well as in an arc-shaped ridge, called the circumpharyngeal ridge. Since the circumpharyngeal ridge represents the caudal limit of the pharynx, it indicates the head/trunk interface at the level of the lateral body wall. These two interfaces of reverse orientation make an S-shaped, head/trunk interface together. Several structures unique to this region develop in this interface. Since the rhombomeric compartmentalization is distinct only in higher vertebrates, the rhombomere-dependent segregation of cephalic crest cells is more likely to be a secondary feature of the vertebrate head. The topographical configuration of the vertebrate crest cell distribution pattern does not support the idea that the vertebrate head evolved as a specialized trunk. but rather supports the idea that two distinct methods of segmental patterning have evolved in rostral and caudal parts of the vertebrate body, which resulted in the head and trunk, respectively. Postotic crest is located at the intermediate level between the trunk and the head, giving rise to both the cephalic and trunk crest cells. Its cephalic components circumpharyngeal crest cells, are distributed only rostral to the S-shaped interface.

Animals↗

PubMed1997

Vertebral artery occlusion after subarachnoid hemorrhage from a dissecting aneurysm of the vertebral artery: case report.

BACKGROUND: Generally speaking, occlusion of the vertebral artery is a finding of a dissecting aneurysm associated with completed stroke. We present a case of a vertebral dissecting aneurysm that produced subarachnoid hemorrhage (SAH). Angiography on the day of hemorrhage, however, demonstrated complete occlusion of the vertebral artery. CASE PRESENTATION: A 44-year-old hypertensive woman suffered a sudden onset of headache and vomiting followed by loss of consciousness due to SAH. Angiography on the day of hemorrhage revealed a complete occlusion of the right vertebral artery just distal to the dissecting aneurysm. This is the first report of such a case. The patient was still considered to be at significant risk of rerupture. Craniotomy and clip occlusion of the right vertebral artery and the origin of the right posterior inferior cerebellar artery were carried out to trap the thin-walled sac. At discharge, the patient had recovered completely except for some left limb ataxia, which subsequently disappeared. CONCLUSIONS: Two options are available for the treatment of such a case: surgical or medical treatment. We employed surgery. Which is the preferred approach, however, is a difficult judgment to make at this juncture.

Adult↗

PubMed2002

Functional equivalency of amphioxus and vertebrate Pax258 transcription factors suggests that the activation of mid-hindbrain specific genes in vertebrates occurs via the recruitment of Pax regulatory elements.

Pax genes encode transcription factors that control key developmental decisions in various animal phyla. The Pax2/5/8 subfamily plays a key role in specification and/or maintenance of vertebrate mid-hindbrain boundary (MHB) region by directly regulating expression of other genes, most notably En2. In the invertebrate chordate amphioxus, expression of AmphiPax2/5/8 is found in many sites that are homologous to the regions of the vertebrate embryo expressing orthologous genes Pax2, Pax5 or Pax8. However, no co-expression of AmphiPax2/5/8 and AmphiEn is detected in the region of the neural tube that might correspond to the vertebrate MHB. Based on this observation and the absence of AmphiWnt expression in this region it appears that amphioxus does not have a MHB. Here we investigated the possibility that the AmphiPax2/5/8, as a key component of MHB development, has lost some of the properties of its vertebrate counterparts. We have analyzed both the DNA-binding and transactivation properties of AmphiPax2/5/8 as well as its ability to interact with the groucho co-repressor. In all these assays AmphiPax2/5/8 is indistinguishable from the human Pax5. In addition, we found two alternatively spliced AmphiPax2/5/8 isoforms that function similarly to the alternatively spliced isoforms of human Pax8. Analysis of the AmphiEn regulatory region provided no evidence for AmphiPax2/5/8 binding and transactivation. Therefore, in amphioxus, AmphiPax2/5/8, although capable of performing all the necessary functions has not been recruited for a developmental mechanism which usually sets up MHB development in vertebrates.

3T3 Cells↗

PubMed1999

Evidence that a plant virus switched hosts to infect a vertebrate and then recombined with a vertebrate-infecting virus.

There are several similarities between the small, circular, single-stranded-DNA genomes of circoviruses that infect vertebrates and the nanoviruses that infect plants. We analyzed circovirus and nanovirus replication initiator protein (Rep) sequences and confirmed that an N-terminal region in circovirus Reps is similar to an equivalent region in nanovirus Reps. However, we found that the remaining C-terminal region is related to an RNA-binding protein (protein 2C), encoded by picorna-like viruses, and we concluded that the sequence encoding this region of Rep was acquired from one of these single-stranded RNA viruses, probably a calicivirus, by recombination. This is clear evidence that a DNA virus has incorporated a gene from an RNA virus, and the fact that none of these viruses code for a reverse transcriptase suggests that another agent with this capacity was involved. Circoviruses were thought to be a sister-group of nanoviruses, but our phylogenetic analyses, which take account of the recombination, indicate that circoviruses evolved from a nanovirus. A nanovirus DNA was transferred from a plant to a vertebrate. This transferred DNA included the viral origin of replication; the sequence conservation clearly indicates that it maintained the ability to replicate. In view of these properties, we conclude that the transferred DNA was a kind of virus and the transfer was a host-switch. We speculate that this host-switch occurred when a vertebrate was exposed to sap from an infected plant. All characterized caliciviruses infect vertebrates, suggesting that the host-switch happened first and that the recombination took place in a vertebrate.

Amino Acid Sequence↗

PubMed1995

Anterolateral decompression of the atlantoaxial vertebral artery for symptomatic positional occlusion of the vertebral artery. Case report.

A case of repeated vertebrobasilar ischemic attacks related to head rotation (bow hunter's stroke) is reported. With head rotation of 45 degrees or more to the right, the patient would become lightheaded and feel as if she were going to lose consciousness. Angiography performed when head rotation was to the right revealed mechanical compression of the left vertebral artery at the foramen transversarium of the axis and an occluded right vertebral artery. Untethering of the vertebral artery as it passed through the foramen transversarium of the atlas in this case completely relieved the patient's symptoms. The authors conclude that contralateral vertebral artery occlusion predisposed this patient to symptomatic vertebrobasilar insufficiency secondary to ipsilateral vertebral artery mechanical stenosis induced by head turning.

Axis, Cervical Vertebra↗

PubMed2004

Three-dimensional color-coded duplex sonography for assessment of the vertebral artery origin and vertebral artery stenoses.

OBJECTIVE: The aim of the study was to assess the potential of 3-dimensional (3D) color-coded duplex sonography (CDS) for evaluation of the vertebral artery origin and stenoses in this location. METHODS: To compare 2-dimensional (2D) and 3D CDS, both techniques were performed in 25 healthy volunteers and in 18 patients with 21 stenoses of the vertebral artery origin. Stenoses were graded in line with hemodynamic criteria on 2D CDS and according to North American Symptomatic Carotid Endarterectomy Trial criteria on 3D CDS. In 6 patients, digital subtraction angiography (DSA) was performed additionally. Stenoses were graded according to North American Symptomatic Carotid Endarterectomy Trial criteria and compared with 2D and 3D sonographic data. RESULTS: Overall correlation of both sonographic techniques concerning the grading of the stenoses was good (r = 0.69; P < .01). The interobserver correlation for assessment of stenoses by means of 3D CDS was high (r = 0.94; P < .01). Three-dimensional CDS correlated excellently with DSA in 3 of 6 patients but showed only intermediate or no correlation in the remaining 3 patients. In contrast, spatial information on the stenotic morphologic characteristics was always very comparable with the results obtained by DSA. CONCLUSIONS: Three-dimensional CDS represents a valuable tool for assessment of the origin of the vertebral artery, allowing important morphologic information on stenoses in this location. For grading of stenoses of the vertebral artery origin, 3D information should be combined with hemodynamic criteria obtained by spectral Doppler imaging in 2D CDS. Three-dimensional CDS could be a valuable tool before interventional procedures of the proximal vertebral artery, saving time and avoiding iodinated contrast agents.

Adult↗

PubMed2000

Tortuosity of the vertebral artery resulting in vertebral erosion.

OBJECTIVE: To discuss the case of a patient with unilateral vertebral artery tortuosity and dilatation resulting in vertebral body and transverse foramen erosion. An emphasis is placed on diagnostic imaging. CLINICAL FEATURES: A 45-year-old man had a frozen shoulder and headaches. Previous arm pain, numbness, and a cold extremity were the result of occlusion of the subclavian artery and had been treated with a subclavian-carotid bypass procedure. INTERVENTION AND OUTCOME: As a result of the angiographic detection of the left vertebral artery dilatation and tortuosity and the concomitant hypoplastic right vertebral artery, high-velocity, low-amplitude manipulation of the cervical spine was contraindicated. However, the patient's symptoms were not related to these findings. Alternatively, low-force manipulation of the cervical spine, shoulder range of motion and muscle techniques were used, and the patient's symptoms diminished significantly with improved shoulder range of motion. CONCLUSION: Clinicians need to be alert to clinical presentations and appropriate imaging protocols in cases of suggested vertebral artery anomaly.

Cervical Vertebrae↗

PubMed1984

Therapeutic occlusion of the vertebral artery for unclippable vertebral aneurysm: relationship between site of occlusion and clinical outcome.

Six cases of unclippable vertebral aneurysms were treated by therapeutic occlusion of the proximal vertebral artery. In three cases, the vertebral artery was clipped proximal to the posterior inferior cerebellar artery (PICA), and all of these patients had a postoperative embolic complication or a fatal subarachnoid hemorrhage. In two cases, the vertebral artery was clipped distal to the PICA and in one case the PICA was absent and the vertebral artery was clipped proximal to the aneurysm. All three of these patients did well without any neurological deficit. Possible mechanisms of the complications are discussed, and the importance of not clipping the PICA is stressed.

Adult↗

PubMed2000

Randomized trial of the effects of risedronate on vertebral fractures in women with established postmenopausal osteoporosis. Vertebral Efficacy with Risedronate Therapy (VERT) Study Group.

The purpose of this randomized, double-masked, placebo-controlled study was to determine the efficacy and safety of risedronate in the prevention of vertebral fractures in postmenopausal women with established osteoporosis. The study was conducted at 80 study centers in Europe and Australia. Postmenopausal women (n = 1226) with two or more prevalent vertebral fractures received risedronate 2.5 or 5 mg/day or placebo; all subjects also received elemental calcium 1000 mg/day, and up to 500 IU/day vitamin D if baseline levels were low. The study duration was 3 years; however, the 2.5 mg group was discontinued by protocol amendment after 2 years. Lateral spinal radiographs were taken annually for assessment of vertebral fractures, and bone mineral density was measured by dual-energy X-ray absorptiometry at 6-month intervals. Risedronate 5 mg reduced the risk of new vertebral fractures by 49% over 3 years compared with control (p<0.001). A significant reduction of 61% was seen within the first year (p = 0.001). The fracture reduction with risedronate 2.5 mg was similar to that in the 5 mg group over 2 years. The risk of nonvertebral fractures was reduced by 33% compared with control over 3 years (p = 0.06). Risedronate significantly increased bone mineral density at the spine and hip within 6 months. The adverse-event profile of risedronate, including gastrointestinal adverse events, was similar to that of control. Risedronate 5 mg provides effective and well-tolerated therapy for severe postmenopausal osteoporosis, reducing the incidence of vertebral fractures and improving bone density in women with established disease.

Absorptiometry, Photon↗

PubMed1998

Health impact associated with vertebral deformities: results from the European Vertebral Osteoporosis Study (EVOS).

To study the association between vertebral deformities and subjective health outcome indicators, including back pain and disability, a cross-sectional survey with spinal radiographs and personal interviews was carried out in 36 study centres in 19 European countries on a total of 15,570 men and women aged 50-79 years (population-based stratified random samples). No interventions were done. The main outcome measures were the presence and intensity of current and previous back pain, functional capacity (ADL questionnaire) and overall subjective health. The presence and intensity of back pain and functional and health impairments varied within wide ranges with no obvious regional pattern. However, the associations between negative health outcomes and vertebral deformity were homogeneous between countries and between centres within countries. In logistic regression analyses weak but significant associations between the presence of vertebral deformities and various health indicators were demonstrated. The magnitude of the associations increased with severity and number of deformities. Compared with subjects without deformities those with low-grade deformities had no or only a weakly elevated risk for back pain, disability and impaired subjective health (odds ratios (OR) 1.2-1.3). The odds ratios increased for individuals with single severe deformities (OR 1.3-2.1) and were highest in those with multiple severe deformities (OR 1.7-4.2). The associations between vertebral deformities and negative health outcomes were stronger in men than in women. In this cross-sectional study radiologically assessed vertebral deformities were therefore weakly associated with both current and previous back pain as well as with functional and health impairments in both women and men. Multiple severe deformities were associated with severe and disabling back pain with stronger effects in men.

Activities of Daily Living↗

PubMed2001

Correlation between vertebral body rotation and two-dimensional vertebral bone density measurement.

The aim of this study was to determine the effect of vertebral rotation, as seen in idiopathic scoliosis, on bone mineral density determination for the lumbar spine. Bone mineral content, biplanar vertebral segment area and calculated bone mineral density of each vertebra from L1 to L4 were obtained for a human cadaveric specimen. The average density for the entire L1-L4 segment was also recorded. This was done with the spine in the midline position as well as in rotation up to a maximum of 60 degrees either side of the midline. The spine was rotated in each direction using 10 degrees increments and two bone density readings were done at each rotation interval. The measured biplanar vertebral segment area increased with increasing rotation from 0 degrees to 50 degrees but decreased after 50 degrees of rotation (r = 0.73, p<0.001). The bone mineral density was significantly negatively correlated with the degree of rotation (r = -0.92, p<0.001). The decrease in measured bone mineral density was nearly 20% when the lumbar spine was rotated from neutral to 60 . This study demonstrates that degree of spinal rotation influences apparent bone mineral density by increasing the apparent vertebral segment area. The measurement change may be as high as 20%. This fact should be considered when investigating scoliotic patients with vertebral segment rotation.

Absorptiometry, Photon↗

PubMed2006

Cost-effectiveness of vertebral fracture assessment to detect prevalent vertebral deformity and select postmenopausal women with a femoral neck T-score>-2.5 for alendronate therapy: a modeling study.

Most fractures occur in postmenopausal women who do not have osteoporosis by bone density criteria (T-score>-2.5). Prevalent vertebral deformity is a strong risk factor for incident fractures independent of bone mineral density, yet the majority of these deformities are clinically unapparent. Spine imaging on a dual-energy densitometer, called vertebral fracture assessment (VFA), can accurately detect these deformities. The purpose of this modeling study was to estimate the lifetime societal costs and health benefits of VFA and confirmatory follow-up radiography to detect prevalent vertebral deformity in osteopenic (T-score -1.5, -2.0, or -2.4) postmenopausal women, followed by anti-resorptive drug therapy for those with one or more deformities. We compared three strategies; no initial drug therapy, 5 yr of initial alendronate therapy, or VFA followed by 5 yr of alendronate therapy in those with one or more vertebral deformities confirmed on radiography (VFA strategy). Results for the base-case analyses showed that the cost per quality adjusted life year (QALY) gained for the VFA strategy relative to no initial drug therapy ranged from 18,000 US dollars (for a 60-yr-old with a femoral neck T-score of -2.4) to 77,000 US dollars (for an 80-yr-old with a T-score of -1.5). VFA with selective confirmatory radiography is cost-effective, assuming a societal willingness to pay per QALY gained of 50,000 US dollars, for postmenopausal women aged 60 to 80 yr with femoral neck T-scores between -2.0 and -2.4, and for women age 60 or 70 yr with a T-score of -1.5. Assuming a societal willingness to pay of 100,000 US dollars per QALY gained, VFA is also cost-effective for women age 80 yr with a T-score of -1.5. These conclusions are robust to reasonable changes in fracture rates, assumed fracture disutility, discount rates, relative risk of fracture attributable to vertebral deformity, alendronate cost, and drug adherence.

Absorptiometry, Photon↗

PubMed2001

Inhomogeneity of human vertebral cancellous bone: systematic density and structure patterns inside the vertebral body.

In the spine, cancellous bone quality is usually assessed for the whole vertebral body in a transverse central slice. Correct identification and assessment of the weakest parts of the cancellous bone may lead to better prediction of fracture risk. The density and structural parameters were systematically investigated inside the thoracic (T-9), thoracolumbar (T12-L1), and lumbar (L-4) vertebral bodies of nine subjects. On both sides of the median sagittal plane, anterior and posterior 8.2 mm vertical cores were harvested in the thoracic vertebra. In the thoracolumbar and lumbar vertebrae, external samples were also cored. Peripheral quantitative computed tomographic (pQCT) density analysis of the 136 cores was performed at four different levels, from the lower to the upper endplate. The relatively thin slice thickness (300 microm) and small pixel size (70 microm x 70 microm) was considered sufficient to investigate the structural parameters on the four transverse slices and in the sagittal and coronal planes (total of 816 images). Using a constant threshold a binary image was generated and the morphometric data were extracted. The binary image was further skeletonized and classical strut analysis was performed. Cancellous bone density was 20% higher in the posterior cores than in the anterior and external cores. Moreover, clear vertical inhomogeneity was noted because the lowest half of the vertebral body presented lower density than the upper half (differences ranging from 25% to 15%). All structural parameters were strongly dependent on the location of the measurement. Structural differences between anterior, posterior, and external areas were mild and followed the density patterns. On the other hand, vertical inhomogeneity of the structural parameters was important. For example, in the thoracolumbar and lumbar vertebrae, the numbers of nodes or node-to-node struts were almost twofold higher in the inferior half than in the superior half (p < 0.01), whereas trabecular thickness and number of free-ends presented a center/close-to-endplate structural pattern, with central trabeculae being 15% thicker (p < 0.05) and presenting 30% fewer free-ends (p < 0.01) than the close-to-endplate ones. Variability of density and structural parameters was high and a substantial part of this variability could be explained by the place inside the vertebral body where the measurement was made. The weak part was not in the center of the body but in its upper half where the lower density did not seem to be compensated by a higher structural architecture. Further clinical investigation could enhance fracture prediction by tracking and focusing on the weakest part of the vertebral body.

Adult↗

PubMed2003

Characteristics of a prevalent vertebral deformity predict subsequent vertebral fracture: results from the European Prospective Osteoporosis Study (EPOS).

The presence of a prevalent vertebral deformity increases the risk of a future vertebral fracture. The aim of this study was to determine whether certain characteristics of the prevalent deformity, including its shape and location in the spine, influenced this effect. The 3100 men and 3500 women who took part in this analysis were recruited from population registers for participation in the European Prospective Osteoporosis Study (EPOS). Subjects had lateral thoracic and lumbar spine x-rays at baseline, and again after a mean interval of 3.8 years. Prevalent morphometric vertebral deformities on the baseline film were identified by the McCloskey-Kanis method. Incident fractures were defined as vertebrae that also satisfied the McCloskey-Kanis criterion for prevalent deformities on the follow-up film, and in addition had at least one height (anterior, mid, or posterior) which had reduced by at least 20% between films. Poisson regression was used to assess the association between various characteristics of the prevalent deformity and the risk of an incident vertebral fracture, with generalised estimating equations used to allow for the fact that each subject contributed several vertebrae to the analysis. The risk of an incident fracture increased with the number of prevalent deformities: relative risk (RR) for one prevalent deformity 3.2 (95% confidence interval (CI); 2.1, 4.8); 9.8 (95% CI;6.1, 15.8) for 2; and 23.3 (95% CI;15.3, 35.4) for 3 or more. Relative risks differed significantly according to the shape of the prevalent deformity, ranging from 5.9 (95% CI; 4.1, 8.6) if the anterior and mid heights were reduced to 1.6 (95% CI;0.8, 3.2) if the posterior and mid heights were reduced. Risks varied also according to the severity of the deformity. There were fivefold differences in relative risk of incident fracture depending on the location of the prevalent deformity within the spine. Compared to vertebrae in subjects with no deformities at baseline, the relative risk of an incident fracture within three vertebrae of a prevalent deformity was greater (7.7 (95% CI;5.6, 10.5)) than the risk in more distant vertebrae (4.0 (95% CI;2.6, 6.0)). In summary, the risk of a subsequent vertebral fracture in individuals with preexisting deformities is importantly influenced by the characteristics of these deformities.

Age Factors↗

PubMed1997

The influence of family history of hip fracture on the risk of vertebral deformity in men and women: the European Vertebral Osteoporosis Study.

There are few data exploring clustering of osteoporotic fractures within families. The aim of this study was to determine the influence of maternal and paternal history of hip fracture on the risk of vertebral deformity. 12,816 men and women aged 50 to 75 years were recruited from population based sampling frames across Europe. Subjects were invited to attend by letter of invitation for an interviewer administered questionnaire and lateral spinal radiographs. Vertebral deformity was defined morphometrically using the McCloskey-Kanis method. 6.4% of men and 7.1% of women reported that their mother had suffered a hip fracture, while 1.7% of both men and women reported that their father had suffered a hip fracture. A maternal history of hip fracture was associated with a modest increased risk of vertebral deformity in men [odds ratio (OR) 1.3, 95% confidence interval (CI) 1.0-1.8], the risk being greater among those aged 65 years and over (OR = 1.5; 95% CI 1.0-2.4) and in those from low prevalence areas. There was no increased risk in women. Paternal history of hip fracture was not associated with vertebral deformity in either sex. In conclusion, maternal history of hip fracture appears to be a risk factor for vertebral deformity, particularly in men.

Aged↗

PubMed2005

[Percutaneous vertebroplasty for osteoporotic vertebral compression fractures: experiences and prospective clinical outcome in 26 consecutive patients with 50 vertebral fractures].

PURPOSE: Prospective evaluation of vertebroplasty for osteoporotic compression fractures concerning pain reduction, demand of analgesics and quality of life. MATERIAL AND METHODS: In 26 consecutive patients, 50 vertebral fractures were treated by percutaneous vertebroplasty under fluoroscopic (n = 44) or combined fluoroscopic/CT guidance (n = 6). Prospective follow-up was performed after 6 (for 50 vertebral fractures) and 12 months (for 27 vertebral fractures). Visual analogue scale (VAS) and numeric rating scale (NRS) was applied for the assessment of pain. Subjective quality of life and analgesics demand was documented semi-quantitatively. RESULTS: Mean interval from the beginning of pain symptoms to therapy was 8.5 weeks. Vertebroplasty was technically successful in all evaluated patients. Pain severity decreased from 10 (defined at baseline as initial pain score) to 2.8 after 6 months and 2.7 after 12 months. Subjective quality of life was reported as very well, well or improved in 92 % (n = 26 after 6 months) or 100 % (n = 13 after 12 months). No need for additional analgesic therapy was observed in 69.3 % (n = 26) after 6 months and 61.5 % (n = 13) after 12 months. Eight newly developed vertebral fractures were observed during follow-up, with 5 fractures directly adjacent to previously treated vertebrae. Leakage of polymethyl methacrylate (PMMA) into the intervertebral space or spinal canal was observed in 22 % and 20 % respectively (n = 50 vertebrae) . No neurologic deterioration or complications requiring surgery were observed. CONCLUSION: Vertebroplasty is a successful therapeutic approach for the treatment of osteoporotic vertebral fractures. Persistent improvement of clinical symptoms was shown at follow-up after 6 and 12 months.

Aged↗

PubMedDate not supplied

Breathing air in air: in what ways might extant amphibious fish biology relate to prevailing concepts about early tetrapods, the evolution of vertebrate air breathing, and the vertebrate land transition?

The air-breathing fishes have heuristic importance as possible models for the Paleozoic evolution of vertebrate air breathing and the transition to land. A recent hypothesis about this transition suggests that the diverse assemblage of marine amphibious fishes occurring primarily in tropical, high intertidal zone habitats are analogs of early tetrapods and that the intertidal zone, not tropical freshwater lowlands, was the springboard habitat for the Devonian land transition by vertebrates. Here we argue that selection pressures imposed by life in the intertidal zone are insufficient to have resulted in the requisite aerial respiratory capacity or the degree of separation from water required for the vertebrate land transition. The extant marine amphibious fishes, which occur mainly on rocky shores or mudflats, have reached the limit of their niche expansion onto land and remain tied to water by respiratory structures that are less efficient in air and more vulnerable to desiccation than lungs. We further argue that evolutionary contingencies actuated by the Devonian origin of the tetrapods marked a critical point of divergence for a way of life in which selection pressures would operate on the physiology, morphology, and natural history of the different vertebrate groups. While chronically hypoxic and shallow water conditions in the habitats of some primitive bony fishes and some amphibians appear similar to the conditions that prevailed in the Devonian, markedly different selection pressures have operated on other amphibians and bony fishes over the 300 million years since the vertebrate land transition. For example, both egg development and larval metamorphosis in extant amphibians are geared mainly toward compensating for the uncertainty of habitat water quality or even the absence of water by minimizing the time required to develop there. In contrast, reproduction by most intertidal (and amphibious) fishes, all of which are teleosts, remains dependent on a planktonic larval phase and is characterized by specializations (brooding) that minimize overdispersal and maximize recruitment back to the littoral habitat.

Adaptation, Physiological↗