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Three-dimensional printing (3Dp) is being increasingly used in medical education. Although the use of such lifelike models is beneficial, well-powered, randomized studies supporting this statement are scarce. Two spinal fracture simulation models were generated by 3Dp. Altogether, 120 medical students (54.2% females) were randomized into three teaching module groups [two-dimensional computed tomography images (CT), 3D, or 3Dp] and asked to answer 10 key anatomical and 4 evaluative questions. Students in the 3Dp or 3D group performed significantly better than those in the CT group, although males in the 3D group scored higher than females. Students in the 3Dp group were the first to answer all questions, and there were no sex-related differences. Pleasure, assistance, effect, and confidence were more predominant in students in the 3Dp group than in those in the 3D and CT groups. This randomized study revealed that the 3Dp model markedly improved the identification of complex spinal fracture anatomy by medical students and was equally appreciated and comprehended by both sexes. Therefore, the lifelike fracture model made by 3Dp technology should be used as a means of premedical education.

The premelting behavior of Nylon 12 has been investigated by two-dimensional (2D) Fourier-transform (FT) near-infrared (NIR) correlation spectroscopy. FT-NIR spectra of Nylon 12 in a cast film have been measured over a temperature range of 30−150 °C. The 2D NIR correlation analysis reveals that there are at least eight bands in the 6800−6100 cm-1 region where the first overtone of an NH stretching mode of Nylon 12 is expected to appear. They may be ascribed to free- and hydrogen-bonded NH groups in various environments. The asynchronous 2D NIR correlation spectrum in the above region indicates that the amide group with a free carbonyl oxygen (structure C) appears first and then unassociated free amide (structure A) and amide with free NH (structure B) follow as the temperature is increased. In the 6000−5500 cm-1 region of the synchronous spectrum, four dominant autopeaks corresponding to the first overtones of the CH2 stretching modes are observed at 5840, 5770, 5680, and 5640 cm-1, and negative cross peaks are found between the 5770 cm-1 band and the rest. This observation, together with the careful inspection of the dynamic NIR spectra, suggests that the band at 5770 cm-1 is due to the contribution of the CH stretching vibration of an ordered or highly associated form of Nylon 12, which decreases with temperature, while other NIR bands correspond to more disordered forms. The corresponding asynchronous spectrum indicates that the intensity variation of the bands at 5840, 5680, and 5640 cm-1 actually occurs at a lower temperature compared to the onset of the intensity decrease of the 5770 cm-1 band. A substantial amount of disordered or dissociated components corresponding to the above three bands start appearing before the disappearance of more ordered components represented by the 5700 cm-1 band. Probably, they appear as the premelting precursors (or even possibly as the indirect cause) to the precipitous decrease of the ordered components associated with the melting of Nylon 12 occurring at a much higher temperature.

It has been shown that, during the S-phase of the cell cycle, the mouse DNA methyltransferase (DNA MTase) is targeted to sites of DNA replication by an amino acid sequence (aa 207-455) lying in the N-terminal domain of the enzyme [Leonhardt, H., Page, A. W., Weier, H. U. and Bestor, T. H. (1992) Cell , 71, 865-873]. In this paper it is shown, by using enhanced green fluorescent protein (EGFP) fusions, that other peptide sequences of DNA MTase are also involved in this targeting. The work focuses on a sequence, downstream of the reported targeting sequence (TS), which is homologous to the Polybromo-1 protein. This motif (designated as PBHD) is separated from the reported targeting sequence by a zinc-binding motif [Bestor , T. H. (1992) EMBO J , 11, 2611-2617]. Primed in situ extension using centromeric-specific primers was used to show that both the host DNA MTase and EGFP fusion proteins containing the targeting sequences were localized to centromeric, but not telomeric, regions during late S-phase and mitosis. Also found was that, in approximately 10% of the S-phase cells, the EGFP fusions did not co-localize with the centromeric regions. Mutants containing either, or both, of these targeting sequences could act as dominant negative mutants against the host DNA MTase. EGFP fusion proteins, containing the reported TS (aa 207-455), were targeted to centromeric regions throughout the mitotic stage which lead to the discovery of a similar behavior of the endogenous DNA MTase although the host MTase showed much less intense staining than in S-phase cells. The biological role of the centromeric localization of DNA MTase during mitosis is currently unknown.

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Objective Interstitial lung disease (ILD) is a relatively common extraarticular manifestation of rheumatoid arthritis (RA) that contributes significantly to disease burden and excess mortality. The purpose of this study was to identify peripheral blood markers of RA-associated ILD that can facilitate earlier diagnosis and provide insight regarding the pathogenesis of this potentially devastating disease complication. Methods Patients with RA who were enrolled in a well-characterized Chinese identification cohort or a US replication cohort were subclassified as having RA–no ILD, RA–mild ILD, or RA–advanced ILD, based on high-resolution computed tomography scans of the chest. Multiplex enzyme-linked immunosorbent assays (ELISAs) and Luminex xMAP technology were used to assess 36 cytokines/chemokines, matrix metalloproteinases (MMPs), and acute-phase proteins in the identification cohort. Unadjusted and adjusted logistic regression models were used to quantify the strength of association between RA-ILD and biomarkers of interest. Results MMP-7 and interferon-γ–inducible protein 10 (IP-10)/CXCL10 were identified by multiplex ELISA as potential biomarkers for RA-ILD in 133 RA patients comprising the Chinese identification cohort (50 RA–no ILD, 41 RA-ILD, 42 RA–indeterminate ILD). The findings were confirmed by standard solid-phase sandwich ELISA in the Chinese identification cohort as well as an independent cohort of US patients with RA and different stages of ILD (22 RA–no ILD, 49 RA-ILD, 15 RA–indeterminate ILD), with statistically significant associations in both unadjusted and adjusted logistic regression analyses. Conclusion Levels of MMP-7 and IP-10/CXCL10 are elevated in the serum of RA patients with ILD, whether mild or advanced, supporting their value as pathogenically relevant biomarkers that can contribute to noninvasive detection of this extraarticular disease complication.