Whole-body MRI in patients with Non-bacterial Osteitis: Radiological findings and correlation with clinical data.

OBJECTIVES: To correlate clinical findings of Non-bacterial Osteitis (NBO) with whole-body MRI (WB-MRI) findings and determine a radiologic index for NBO (RINBO) which allows standardized reporting of WB-MRI. METHODS AND MATERIALS: In a prospective study, 40 patients with diagnosis of NBO underwent clinical examination and WB-MRI in which STIR- and T1- weighted images were assessed for NBO-typical lesions. Parameters of interest for RINBO were: number of radiologically active lesions (RAL), size of the patients' maximum RAL presence of extramedullary and spinal involvement. Results were tested for statistical agreement of clinical and MR-based lesion detection. RINBO was tested for correlation with clinical activity. RESULTS: 62/95 clinically/radiologically active lesions were found in 30/33 patients. In 45 % of the cohort, more active lesions were detected by WB-MRI than by clinical examination. RINBO was a significant predictor for the presence of clinically active lesions. CONCLUSION: WB-MRI is a powerful diagnostic tool for patients with NBO which can reveal asymptomatic disease activity. With RINBO a standardized evaluation approach is proposed which helps assessing radiologic disease burden and predicts clinical disease activity. KEY POINTS: • Whole body MRI is a powerful diagnostic tool for patients with non-bacterial Osteitis. • Whole body MRI can reveal asymptomatic disease activity. • The radiologic index RINBO offers a standardized evaluation approach.

Synthesis and properties of isomeric pyridyl-containing chitosan derivatives.

Here we report on the method of synthesis in gel of a new heterocyclic aminopolymer-N-2-(4-pyridyl)ethylchitosan (4-PEC) via direct addition of 4-vinylpyridine to chitosan that yields a derivative with the substitution degree (DS) up to 0.8. The comparison of reactivity, thermal, spectroscopic, and sorption properties of a new derivative and its isomer N-2-(2-pyridyl)ethylchitosan (2-PEC) is presented. 2-PEC has higher sorption capacity and forms more stable chelates with [PdCl4](2-) and [PtCl6](2-) ions than 4-PEC, but the latter shows higher selectivity to noble metals ions in the presence of Cl(-) ions. A gradual increase of the sorption capacities and the affinity coefficient for Cu(2+) and Ni(2+) in the row chitosan<4-PEC<2-PEC was related to the increase of electron donor nitrogen atoms content and chelating properties of 2-PEC. A nearly negligible increase of the 4-PEC sorption capacity for Ag(+), as compared to plain chitosan, was suggested to be dependent on the difference in complexation models for 2-PEC and 4-PEC derivatives. The density functional theory (DFT) calculations have shown that the "pendant" model of the complex with Ag(I) is energetically favorable only for 2-PEC derivative, while in cases of chitosan and 4-PEC only "bridge" complexes can be formed that results in lower sorption capacity.

Detection and identification of Mycobacterium spp. in clinical specimens by combining the Roche Cobas Amplicor Mycobacterium tuberculosis assay with Mycobacterium genus detection and nucleic acid sequencing.

We have recently developed a PCR assay for detection of Mycobacterium spp. at the genus level based on the Cobas Amplicor platform. The sensitivities for smear-positive and smear-negative specimens were found to be 100% and 47.9%, respectively. The specificity was 97.7%, the positive predictive value 84.6%, and the negative predictive value 93.1%. In a follow-up study, we have systematically evaluated the Mycobacterium genus assay in parallel with the Cobas Amplicor Mycobacterium tuberculosis assay on 2,169 clinical specimens, including respiratory and nonrespiratory specimens. Based on the genus assay, nontuberculous mycobacteria were readily detected and identified to the species level by PCR-mediated sequencing. In addition, our data point to a limited specificity of the Cobas Amplicor M. tuberculosis assay.

Laser-induced structures in a polymer blend in the vicinity of the phase boundary.

We have determined the diffusion, thermal diffusion, and Soret coefficients of a poly(dimethyl siloxane)/poly(ethyl-methyl siloxane) (PDMS/PEMS) polymer blend as a function of composition and temperature within the homogeneous phase. The critical slowing down of the diffusion and the corresponding critical divergence of the Soret coefficient are described within the pseudospinodal concept both for critical and off-critical compositions. These data are used to model in detail the channel-like structures that form due to the Soret effect when a focused laser beam is scanned across a polymer film of 100microm thickness. A moderate vertical asymmetry is attributed to solutal convection. Although heat rapidly diffuses away from the laser focus, the composition distribution in the early stage resembles the sharp profile of the laser beam. PDMS accumulates within the center of the structures, whereas a thin PEMS-rich layer is formed that isolates the central core from the windows. Experimentally, the structures are analyzed by means of phase contrast microscopy. Possible applications as rewritable optical waveguides or tunable phase plates are briefly discussed.

Thermal patterning of a critical polymer blend.

Utilizing the Soret effect, we have employed a moderately focused laser beam (30 microm, 20 mW) to write spatial composition patterns into layers of the critical polymer blend poly(dimethyl siloxane)/poly(ethyl-methyl siloxane) (PDMS/PEMS, M(w)=16.4/22.8 kg/mol) both in the one- and in the two-phase region a few degrees above and below the critical temperature T(c)=37.7 degrees C. Because of the critical divergence of the Soret coefficient, moderate temperature gradients are sufficient to induce composition modulations of large amplitude. In the two-phase regime the spinodal demixing pattern can be locally manipulated in a controlled way. 2D simulations based on a modified Cahn-Hilliard equation are able to reproduce the essential spatial and temporal features observed in the experiments.

Metastatic patterns in patients with carcinomas of the lower esophagus and upper rectum.

The frequency of metastatic involvement of eight target organs was examined in people dying as a consequence of squamous cell carcinomas of the lower third of the esophagus or adenocarcinomas of the upper third of the rectum. In both groups, there was a stronger association of metastatic incidence in the target organs with organ blood flow per gram in patients with liver metastases than without. The results suggest that this association, which is consistent with the 'mechanical' hypothesis of metastatic pattern, is only seen in people with advanced disease and that in the others temporal limitations imposed by death or cure prevent full development of the pattern. The data suggest that in accord with the 'cascade' theory, cancer cells must first form metastases in the liver, that cells from these metastases not the primary cancer, then form metastases in the lungs; cancer cells from the lung metastases then subsequently disseminate with a trend towards an arterial pattern. Data from animal experiments suggest that owing to the inefficiency of the metastatic process in terms of cancer cells, this sequential process is slow relative to tumor development and that this time base affects expression of metastatic pattern. This proposed scheme for metastatic pattern development provides evidence in favor of Ewing's 'mechanical' hypothesis for two histologic types of cancer, each growing in one designated primary site. It does not exclude a role for 'seed and soil' effects in these and other cancers.