Sonographic evaluation of hip joint effusion in osteoarthritis with correlation to radiographic findings.

PURPOSE: Hip joint effusion is expected in rapidly destructive osteoarthritis, a diagnosis often only made retrospectively at the end stage of the disease. This study assesses whether the presence of an effusion identified during routine ultrasound-guided hip injection may suggest a more aggressive process such as rapidly destructive osteoarthritis. METHODS: After the observation of 10 index cases of rapidly destructive osteoarthritis in patients who presented with a joint effusion on ultrasound, we retrospectively reviewed 94 hips from 89 patients who underwent ultrasound-guided hip injection for pain. Preinjection longitudinal ultrasound images of the anterior capsule adjacent to the femoral neck and inferior to the femoral head were reviewed to determine if a joint effusion was present and the size of the effusion if one was there. Comparison of effusion size was then made between those hips that had a clinical and radiographic diagnosis of osteoarthritis and those who had rapidly destructive osteoarthritis by comparing the severity of joint effusion, if one was present. RESULTS: Patients with rapidly destructive osteoarthritis were more likely to have a large joint effusion 60% (3/5) than were those with osteoarthritis 6.7% (6/89) (p = 0.013). CONCLUSIONS: Large joint effusions identified sonographically correlate well with radiographic findings of rapidly destructive osteoarthritis. Given rapid onset and severity of the disease, when a large joint effusion is identified on routine hip intervention, patients should be forewarned of the potential for this disease process.

Transarterial embolization of symptomatic focal nodular hyperplasia.

PURPOSE: To evaluate the effectiveness of small size trisacryl gelatin microsphere embolization as a minimally invasive treatment option for patients with symptomatic focal nodular hyperplasia (FNH). MATERIALS AND METHODS: A retrospective review was performed of experience with transarterial bland embolization of FNH during the period 2006-2011 in 12 patients (10 women and 2 men; age range, 18-61 y) with a total of 17 lesions presenting with symptoms of pain. FNH was pathologically proven in 11 lesions from 10 patients; the remaining lesions exhibited the classic imaging appearance for FNH. All patients underwent superselective embolization with 100-300 µm trisacryl gelatin microspheres. Lesion size and contrast enhancement before and after treatment were compared to determine success of the procedure. Clinical response was determined by review of the electronic medical record. RESULTS: After embolization, seven patients showed complete resolution and five patients showed partial resolution of symptoms. Compared with imaging performed before the procedure, mean decrease in lesion size after embolization was 61% (range, 26%-90%) on cross-sectional imaging obtained 4-10 weeks after embolization and 87% (range, 54%-98%) on subsequent imaging. Diminished contrast enhancement was universally noted, with 5 of 17 lesions showing complete lack of residual enhancement. CONCLUSIONS: Transarterial bland embolization of FNH with trisacryl gelatin microspheres in symptomatic patients is a suitable treatment alternative to surgical resection.

How Does an Amide-N Chemical Shift Tensor Vary in Peptides?

This study addresses a void in the existing literature on the amide-(15)N chemical shift anisotropy (CSA) tensor of peptides: a systematic investigation of how the tensor varies in different peptides. Amide-(15)N CSA tensors for several dipeptides are obtained using quantum chemical calculations, as well as for a series of model Ala-X and X-Ala sequences in both α-helical and ß-sheet conformations (where X is one of the naturally occurring amino acids). The calculated values show a significant variation in both isolated and extended peptide structures. Hydrogen bonding at both the carbonyl group and the N-H bond of the peptide plane is shown to affect the principal values of the tensor. Calculations on model peptides indicate that the amide-(15)N CSA tensor is dependent on atoms located within a distance of five bonds. Consequently, the tensor of a given peptide residue is unaffected by residues other than those adjacent to it, which implies that the amide-(15)N CSA tensor should be considered in the context of tripeptide sequences. This further suggests that the amide-(15)N CSA tensor of the second residue of a given tripeptide sequence may be extrapolated to the same sequence in any other polypeptide or protein, given the same backbone conformation and intermolecular environment. These conclusions will facilitate future NMR structural studies of proteins.

Ab initio study of (13)C(alpha) chemical shift anisotropy tensors in peptides.

This study reports magnitudes and the orientation of the (13)C(alpha) chemical shift anisotropy (CSA) tensors of peptides obtained using quantum chemical calculations. The dependency of the CSA tensor parameters on the energy optimization of hydrogen atom positions and hydrogen bonding effects and the use of zwitterionic peptides in the calculations are examined. Our results indicate that the energy optimization of the hydrogen atom positions in crystal structures is necessary to obtain accurate CSA tensors. The inclusion of intermolecular effects such as hydrogen bonding in the calculations provided better agreement between the calculated and experimental values; however, the use of zwitterionic peptides in calculations, with or without the inclusion of hydrogen bonding, did not improve the results. In addition, our calculated values are in good agreement with tensor values obtained from solid-state NMR experiments on glycine-containing tripeptides. In the case of peptides containing an aromatic residue, calculations on an isolated peptide yielded more accurate isotropic shift values than the calculations on extended structures of the peptide. The calculations also suggested that the presence of an aromatic ring in the extended crystal peptide structure influences the magnitude of the delta(22) which the present level of ab initio calculations are unable to reproduce.