Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q86TM3 (cage)
 29,987 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of this work was the 3D-simulation of a dielectric resonator for high-field-MRI. A 12-rod-bird-cage-resonator was simulated in a first step, in order to verify the capability of the commercial simulation software MAFIA to simulate homogeneous, transversal B-fields in resonators. The second step was the simulation of frequency-independent dielectric ceramic resonators for static magnetic field strengths of 7 T and 12 T (294 MHz and 504 MHz respectively). The results were compared to the measured results of a manufactured TiO2- and a Al2O3-resonator. Only minor deviations showed up. These results led to the conclusion that dielectric resonators for high field MRI can be optimised using numerical field calculation software.
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PMID:Simulation of a birdcage and a ceramic cavity HF-resonator for high magnetic fields in magnetic resonance imaging. 1246 94

It was early shown that the macrocyclic Ln(DOTA) complexes (DOTA = 1,4,7,10-tetra-azacyclododecane-N,N',N' ',N' "-tetraacetic acid) exists in solution as a mixture of two enantiomeric pairs of diastereoisomers differing in the ligand conformation, namely, square antiprismatic (SA) and twisted square antiprismatic (TSA) geometries, respectively. Later, extensive (1)H NMR investigations suggested that a coordination change may be superimposed on this conformational equilibrium involving two additional structures in which the metal ion possesses a coordination number of eight (CN 8). It was predicted that these two species, lacking the apical coordinated water molecule, would maintain the SA and TSA coordination geometries, and therefore, they have been labeled as SA' and TSA', respectively. In this work we report the X-ray solid-state crystal structure determination of six Ln(DOTA) complexes representative of all four coordination geometry typologies deduced from NMR solution studies. A distinctive structural feature that discriminates SA (and SA') and TSA (and TSA') structures is represented by the twist angle between the two square planes of the antiprism, the basal four nitrogen, and the apical four oxygen planes. [Ce(DOTA)(H(2)O)](-) displays a TSA structural typology with a twist angle of 25 degrees and a Ce-O(water) distance of 2.59 A. The SA-type structure has been found in the case of complexes with Pr(III), Nd(III), and Dy(III), where the twist angle is 39, 39, and 38 degrees, respectively, and the metal-water oxygen distance varies significantly (Pr-O(w) 2.529 A; Nd-O(w) 2.508 A; and Dy-O(w) 2.474 A). [Tm(DOTA)](-) displays a TSA'-type structure with a twist angle of 24 degrees. As compared with the TSA structure of the corresponding Ce(III) complex, the Tm(III) complex shows an overall marked shrinkage of all metal-nitrogen and metal-oxygen distances (ca. 0.2 A), which reflects the contraction of the metal ionic radius across the series but also the effect associated with the decrease of the CN from 9 to 8. In [Sc(DOTA)](-), the even smaller ionic radius of Sc(III) shifts the geometry of the coordination cage to the more compact SA' typology with a twist angle of 41 degrees, a value very similar to that found in the SA structures of lanthanide(III) ions with CN 9. Finally, an investigation was made into the hydration spheres of the complexes with SA and TSA geometries to account for the experimental evidence of a markedly different rate of water exchange for the two isomeric structures. This is of fundamental importance to the understanding of the corresponding Gd(III) complexes as MRI contrast agents.
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PMID:Structural variations across the lanthanide series of macrocyclic DOTA complexes: insights into the design of contrast agents for magnetic resonance imaging. 1251 89

We experienced perioperative management for excision of a huge sternal chondrosarcoma squeezing the heart. A 46-year-old woman could not sleep due to dyspnea for 6 months. Dyspnea increased in the right decubitus and disappeared in the left decubitus. This suggested that the heart was squeezing the tumor. MRI and echocardiography revealed no invasion to the heart. Surgical removal was proposed. Anesthesia was induced with propofol and fentanyl. As this tumor composed of bone-like tissue and was tightly connected with thoracic cage, we thought that the use of muscle relaxant at the induction of anesthesia would not cause cardiovascular collapse and ventilation insufficiency even if the tumor was huge. Vecuronium was administered to facilitate endotracheal intubation. Hemodynamic variables were stable and mask ventilation was uneventful. Anesthesia was maintained with propofol, sevoflurane, supplemental dose of fentanyl and epidural anesthesia. The tumor had invaded the myocardium and was successfully flaked off from the myocardium without using any assisted devices. The tumor was excised including thoracic wall (sternum and parts of 3rd to 12th ribs, 20 cm in diameter). Thoracoplasty was performed using Marlex Mesh. Muscle relaxant was reversed after the end of the operation. Respiration was stable without flail chest. Endotracheal tube was successfully removed in the operation room. The postoperative course was uneventful.
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PMID:[Anesthetic management of a patient with squeezed heart by huge sternal tumor]. 1291 Sep 79

The purpose of this study was to evaluate the results of treatment of symptomatic cervical disc herniation using interbody cages and anterior plate fixation. Fifteen patients were studied retrospectively. An MRI study of the cervical spine was performed preoperatively in all patients. The levels involved were C5-C6 in 9 cases, C6-C7 in 4 and C3-C4 in 1, while 1 patient had disc disease at the C5-C6, C6-C7 levels, Surgical treatment included anterior approach of the cervical spine, removal of the degenerative disc, excision of osteophytes and insertion of an interbody cage which was filled in with bovine allograft and demineralised bone matrix. The spinal unit was stabilized with an anterior plate and screws. No cervical splint was used postoperatively. The patients were followed up for 7 years on average after surgery. No failure or migration of the implants was noted, while bone fusion was achieved radiologically within 6 months postoperatively in all cases. The benefits of this surgical technique are the maintenance of cervical lordosis and disc space height, the high fusion rate, as well as avoidance of cervical orthoses.
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PMID:Combined interbody cage and anterior plating in the surgical treatment of cervical disc disease. 1558 35

A 45-year-old woman presented with recent onset of left-sided chest pain. On clinical examination, these symptoms seemed to be strictly localized to a region that was marked by a long-standing cutaneous erythematous lesion. Laboratory results showed no gross abnormalities. Radiological imaging including conventional X-ray, MRI scans, and 3D CT reconstruction of the rib cage revealed circumscript destruction of the left lateral ribs 9-11. Histological analysis of a rib biopsy showed angiomatous hypervascularization and intracortical fibrosis. In keeping with these findings, the patient's condition was diagnosed as Gorham-Stout disease, a rare condition with localized, often unilateral, bone destruction. Monotherapy with bisphosphonates (pamidronate 30 mg i.v. every 3 months) was initiated, leading to rapid disappearance of local pain. Follow-up over 24 months documented a stable clinical and radiological picture without evidence of progressive bone destruction.
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PMID:Gorham-Stout disease--stabilization during bisphosphonate treatment. 1564 29

The objective of this study was to compare respiratory motions of the chest wall in the healthy elder subjects (N = 5; mean age, 71 years old) with those in healthy young subjects (n = 9; mean age, 29 years old). Thirty sequential images (scanning time, 0.4s per image) of dynamic MRI on sagittal and coronal planes were obtained while the subjects were deeply breathing. Lung volume change was simultaneously measured with pneumotachometer. In the elder subjects, dimensions of the middle and posterior parts of the diaphragm were linearly related to instantaneous lung volume. There were poor correlation between motion of the anterior diaphragm and transverse motions of the upper rib-cage and lower rib-cage. The contribution of individual part of the chest wall motion to a unit lung volume change, assessed by slope of the linear regression line, in elder subjects were not significantly different from those in young subjects. Either in the elder or young subjects, the middle and posterior parts of the diaphragm moved coordinately. We conclude that chest wall motion in the healthy elder subjects is not different from that in healthy young people and that middle and posterior parts of the diaphragm act as one functional unit during deep breathing.
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PMID:An analysis of the chest wall motions using the dynamic MRI in healthy elder subjects. 1595 94

Arthrodesis using interbody cages has demonstrated high fusion rates. However, permanent cages are exposed to stress-shielding, corrosion, and may require explanation when necessary. Polylactic acid (PLA) bioresorbable cages are developed for avoiding these problems, but significant tissue reaction has been reported with 70/30 PLDLLA in some preclinical animal studies. The objective was to evaluate 96/4 PLDLLA cages in a sheep model over 3 years. Sixteen sheeps underwent one level anterior lumbar interbody fusion using 96/4 PLDLLA cages, filled and surrounded with cancellous bone graft from the iliac crest. Six groups of three animals were killed after 3, 6, 9, 12, 24, and 36 months. Harvested lumbar spine had radiographic, MRI, and CT evaluation and histological analysis. Histological results: cage swelling and slight signs of fragmentation associated to fibrocartilaginous tissue apposition at 3 months; bone remodeling around the cage with direct apposition of the mineralization front at 6 months; active cage degradation and complete fusion around the cage at 9 months; cage fragmentation and partial replacement by bone tissue at 12 months; bone bridges in and around the cage at 24 months; full resorption and intervertebral fusion at 36 months. Radiological results: partial arthrodesis at 3 months; definite peripheral arthrodesis at 6 months; similar aspect at 9 months; significant cage resorption at 12 months; definite inner and outer fusion at 24 months; complete cage resorption and calcification at the location of the cage at 36 months confirmed histological observations. Radiographic, CT scan, MRI, and histological data were consistent for showing progressive resorption of 96/4 PLDLLA, interbody fusion, and bone remodeling, with no significant signs of local intolerance reaction. These results are promising and suggest further development of 96/4 PLDLLA cages.
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PMID:Evaluation of the 96/4 PLDLLA polymer resorbable lumbar interbody cage in a long term animal model. 1673 99

It is not always easy to predict the degree of symptomatic improvement to be expected in a patient undergoing surgery for cervical disc herniation and radiculopathy. Here we investigate whether preoperative electromyography (EMG) can help select those most likely to benefit from intervention. We prospectively evaluated 20 patients whose required operative level was unclear after clinical examination and MRI scan alone. The surgical procedures was anterior cervical interbody fusion with the AcroMed carbon fibre cage. Clinical assessment employed using validated scoring systems (Prolo functional and economic scoring system). Patients underwent MRI preoperatively, and were assessed pre and postoperatively with neurophysiological studies (NPS) including nerve conduction studies and concentric needle EMG. Patients with preoperative evidence of cervical nerve root involvement on EMG (group A, n = 8) had better outcome (P = 0.001) following discectomy and anterior fusion than patients who had no evidence of nerve root damage on EMG (group B, n = 12). Prolo mean score +/- SEM for group A was 7.375 +/- 0.3750 and for group B was 5.583 +/- 0.2876. Thus, NPS are a valuable tool in selecting patients in this subgroup for cervical surgery.
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PMID:The value of neurophysiological and imaging studies in predicting outcome in the surgical treatment of cervical radiculopathy. 1694 28

Xenon-129 biosensors offer an attractive alternative to conventional MRI contrast agents due to the chemical shift sensitivity and large nuclear magnetic signal of hyperpolarized (129)Xe. Here, we report the first enzyme-responsive (129)Xe NMR biosensor. This compound was synthesized in 13 steps by attaching the consensus peptide substrate for matrix metalloproteinase-7 (MMP-7), an enzyme that is upregulated in many cancers, to the xenon-binding organic cage, cryptophane-A. The final coupling step was achieved on solid support in 80-92% yield via a copper (I)-catalyzed [3+2] cycloaddition. In vitro enzymatic cleavage assays were monitored by HPLC and fluorescence spectroscopy. The biosensor was determined to be an excellent substrate for MMP-7 (K(M) = 43 microM, V(max) = 1.3 x 10(-)(8) M s(-1), k(cat)/K(M) = 7,200 M(-1) s(-1)). Enzymatic cleavage of the tryptophan-containing peptide led to a dramatic decrease in Trp fluorescence, lambda(max) = 358 nm. Stern-Volmer analysis gave an association constant of 9000 +/- 1,000 M(-1) at 298 K between the cage and Trp-containing hexapeptide under enzymatic assay conditions. Most promisingly, (129)Xe NMR spectroscopy distinguished between the intact and cleaved biosensors with a 0.5 ppm difference in chemical shift. This difference most likely reflected a change in the electrostatic environment of (129)Xe, caused by the cleavage of three positively charged residues from the C-terminus. This work provides guidelines for the design and application of new enzyme-responsive (129)Xe NMR biosensors.
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PMID:Designing 129Xe NMR biosensors for matrix metalloproteinase detection. 1701 9

Intraosseous schwannomas or neurilemomas are rare benign neoplasms that account for less than 0.2% of primary bone tumours. Very rarely they have been observed in lumbar vertebrae. We report a neurilemoma involving the lower thoracic spine and present the clinical, radiological and histological findings with surgical management and 5-year follow-up. An 18-year-old-male presented with back pain and deteriorating locomotor function. Neurological examination revealed wasting of both calves and weakness in plantar flexion and dorsiflexion bilaterally. X-rays showed a D12 vertebral body abnormality with cystic changes and collapse of the body and pedicle. MRI showed a tumor occupying the D12 vertebrae with perivertibral protrusion compressing the thecal sac. Surgical decompression, excision and stabilisation with an extendable cage, bone graft and anterior rod system were achieved through a thoracolumbar approach. Histology results confirmed an intraosseous schwannoma with no remnants of an originating nerve. These tumors are rare but can be successfully treated with surgical excision and maintenance of spinal stability with recovery of neurological and functional change. Recurrence is uncommon.
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PMID:Intraosseous schwannoma of D12 thoracic vertebra: diagnosis and surgical management with 5-year follow-up. 1708 54


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