Background
Measures of oxygenation have not been assessed for prognostic significance in systemic sclerosis-related interstitial lung disease (SSc-ILD).
Methods
83 subjects with SSc-ILD performed a maximal cardiopulmonary exercise test with an arterial line. The agreement between peripheral oxygen saturation (SpO2) and arterial oxygen saturation (SaO2) was examined and survival differences between subgroups of subjects stratified on SpO2 were analysed. Cox proportional hazards analyses were used to examine the prognostic capabilities of SpO2.
Results
At maximal exercise the mean (SD) difference between SpO2 and SaO2 was 2.98 (2.98) and only 15 subjects had a difference of >4 points. The survival of subjects with SSc-ILD whose maximum exercise SpO2 (SpO2max) fell below 89% or whose SpO2max fell >4 points from baseline was worse than subjects in comparator groups (log rank p = 0.01 and 0.01, respectively). The hazard of death during the median 7.1 years of follow-up was 2.4 times greater for subjects whose SpO2max fell below 89% (hazard ratio 2.4, 95% CI 1.1 to 4.9, p = 0.02) or whose SpO2max fell >4 points from baseline (hazard ratio 2.4, 95% CI 1.1 to 5.0, p = 0.02).
Conclusion
In patients with SSc-ILD, SpO2 is an adequate reflection of SaO2 and radial arterial lines need not be inserted during cardiopulmonary exercise tests in these patients. Given the ease of measurement and its prognostic value, SpO2 should be considered as a meaningful clinical and research outcome in patients with SSc-ILD.
PURPOSE. To investigate alterations in the morphologic, compositional, and biomechanical properties of the internal limiting membrane (ILM) in pathologic myopic foveoschisis (MF) eyes. METHODS. ILM specimens were peeled from 61 eyes with MF and 56 eyes with stage III/IV idiopathic macular hole (IMH) as a control. Samples were analyzed for transmission electron microscopy (TEM), scanning electron microscopy, immunofluorescence, Western blotting, and atomic force microscopy. ILM characteristics were compared between the two groups. RESULTS. TEM findings revealed that thickness of the MF ILMs significantly decreased compared with that of IMH ILMs (0.753 6 0.215 vs. 1.894 6 0.247 lm; P < 0.0001). The vitreal side stiffness of the MF ILMs was markedly higher than that of the IMH ILMs (3.520 6 0.803 vs. 0.879 6 0.230 MPa, P < 0.0001). Comparing with the IMH group, collagen IV exhibited decreased concentration and different immunofluorescence distribution in ILMs of MF eyes, so also protein a3 (IV), a4 (IV), and a5 (IV). The immunofluorescence staining results showed that astrocytes were observed in none of the IMH eyes and in 12 of 16 MF eyes (75%, P < 0.0001). CONCLUSIONS. These alterations in the MF ILMs appear to be associated with Müller cell and astrocyte reactive gliosis. The present findings contribute to a more in-depth understanding of the pathogenesis of MF.
Polypyrimidine tract-binding protein (PTB), as a member of the heterogeneous nuclear ribonucleoprotein family, functions by rapidly shuttling between the nucleus and the cytoplasm. PTB is involved in the alternative splicing of pre-messenger RNA (mRNA) and almost all steps of mRNA metabolism. PTB regulation is organ-specific; brain-or muscle-specific microRNAs and long noncoding RNAs partially contribute to regulating PTB, thereby modulating many physiological and pathological processes, such as embryonic development, cell development, spermatogenesis, and neuron growth and differentiation. Previous studies have shown that PTB knockout can inhibit tumorigenesis and development. The knockout of PTB in glial cells can be reprogrammed into functional neurons, which shows great promise in the field of nerve regeneration but is controversial.
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