ABSTRACT
Friedreich's ataxia (FA) is a hereditary disease, which leads to degenerative changes in the spinal cord and cerebellum (incidence 1:50,000). These changes are caused by a defect in the gene that encodes a mitochondrial gene called frataxin and causes muscle weakness, scoliosis, cardiomyopathy and impaired glucose tolerance. Therefore, these patients require special care during anaesthesia. We report the case of a 25-year-old primigravida with a history of FA and dorsal stabilisation of the vertebral column, who was admitted to our hospital for elective caesarean section. Due to increased sensitivity to muscle relaxants, peridural anaesthesia with 8 ml 0.75% ropivacaine and 10 microg sufentanil was used in this case. The perioperative neurological consultation revealed no undue exacerbation of symptoms.
Subject(s)
Amides , Anesthesia, Epidural , Anesthesia, Obstetrical , Anesthetics, Local , Cesarean Section , Friedreich Ataxia/physiopathology , Adult , Anesthetics, Intravenous , Bone Plates , Female , Friedreich Ataxia/complications , Humans , Postoperative Care , Pregnancy , Ropivacaine , Spine/surgery , SufentanilABSTRACT
The diagnosis of osteoporosis is generally based on the assessment of bone mineral content with dual X-ray absorptiometry (DXA) but does not account for the spatial distribution and inherent material properties of the tissue. Peripheral quantitative computed tomography (pQCT) permits one to measure the compartment-specific density and geometry-based parameters of cortical bone. Quantitative ultrasound (QUS) parameters are associated with material properties of cortical bone. The purpose of this study was to test the hypothesis that pQCT and cortical QUS provide additional information to DXA in predicting structural strength of the distal radius. The intact right arm and the isolated left radius were harvested from 70 formalin-fixed cadavers (age 79+/-11 years). The bone mineral content (BMC) was assessed with DXA at the radial metaphysis and shaft. pQCT was also used at the metaphysis and the shaft, while QUS was employed only at the shaft. The failure loads of the radius were assessed by use of a 3-point bending test (isolated radius) and a complex fall simulation (intact arm). The BMC (DXA) displayed a correlation of r=0.96 with the failure moments in 3-point bending ( P<0.001). The correlation between failure load and geometry-based parameters (pQCT) ranged from r=0.85 to r=0.96 and was r=0.64 for the speed of sound (QUS) ( P <0.001). Cortical thickness (pQCT) improved the prediction marginally (r=0.964) in combination with DXA. For the fall simulation, the correlation coefficients were r=0.76 for BMC (DXA) of the shaft, r=0.83 for metaphyseal bone content (pQCT), r=0.55 for QUS, and ranged from r=0.59 to r=0.74 for geometry-based parameters at the shaft (pQCT). pQCT and QUS parameters provided no significant improvement versus DXA alone. Measurement of bone mass by DXA or pQCT thus appears to be sufficient as a surrogate of mechanical strength and fracture risk of the distal radius.
Subject(s)
Osteoporosis/diagnosis , Radius/physiopathology , Absorptiometry, Photon , Aged , Aged, 80 and over , Bone Density , Female , Humans , Male , Middle Aged , Models, Anatomic , Osteoporosis/diagnostic imaging , Radius/diagnostic imaging , Stress, Mechanical , Tomography, X-Ray Computed , UltrasonographyABSTRACT
It is shown that, for an oriented sample, the 13C magnetic shielding tensor of a specific nucleus can be determined from the spinning sideband intensities in a 2D spectrum obtained from a 13C rotor-synchronized 2D CPMAS experiment, originally designed by Harbison and co-workers (G.S. Harbison, V. Vogt and H.W. Spiess, J. Chem. Phys., 86(3) (1987) 1206; G.S. Harbison, H.W. Spiess, Chem. Phys. Lett., 124 (1986) 128). In our fitting procedure, we combined their multilinear regression analysis for the determination of the order parameters with a variation both of the principal values of the magnetic shielding tensor and of the direction of the principal axes relative to the molecule. The magnetic shielding principal elements of the nonprotonated aromatic carbon in poly(ethylene terephthalate) (PET) fibres and of the aromatic carbons in the central ring of an oriented liquid crystalline polymer network are reported. We estimate that the accuracy of the principal values is within 5 ppm.
