Investigation of molecular mechanisms of experimental compounds in murine models of chronic allergic airways disease using synchrotron Fourier-transform infrared microspectroscopy

The ovalbumin-induced (OVA) chronic allergic airways murine model is a well-established model for investigating pre-clinical therapies for chronic allergic airways diseases, such as asthma. Here, we examined the effects of several experimental compounds with potential anti-asthmatic effects including resveratrol (RV), relaxin (RLN), L-sulforaphane (LSF), valproic acid (VPA), and trichostatin A (TSA) using both a prevention and reversal model of chronic allergic airways disease. We undertook a novel analytical approach using focal plane array (FPA) and synchrotron Fourier-transform infrared (S-FTIR) microspectroscopic techniques to provide new insights into the mechanisms of action of these experimental compounds. Apart from the typical biological effects, S-FTIR microspectroscopy was able to detect changes in nucleic acids and protein acetylation. Further, we validated the reduction in collagen deposition induced by each experimental compound evaluated. Although this has previously been observed with conventional histological methods, the S-FTIR technique has the advantage of allowing identification of the type of collagen present. More generally, our findings highlight the potential utility of S-FTIR and FPA-FTIR imaging techniques in enabling a better mechanistic understanding of novel asthma therapeutics

Clinical characteristics and predictors of mortality in 67 patients with primary pyomyositis: A study from North India

Primary pyomyositis is infection of the skeletal muscles in the absence of adjacent skin, soft tissue, and bone infection. This study was undertaken to look at the spectrum of clinical presentations, therapeutic interventions, and their outcomes and also to evaluate the association of various risk factors with mortality. This was a retrospective study in which the patients admitted with the diagnosis of primary pyomyositis from January 2000 to June 2007 were included. Their demographic details, clinical and laboratory data, Sequential Organ Failure Assessment (SOFA) score at presentation, treatment instituted, complications encountered, and hospital outcome were recorded. Sixty-seven patients (42 males and 25 females) with a diagnosis of primary pyomyositis were included. Median age at the time of presentation was 37 years (interquartile range = 25-50 years). Common presenting symptoms were myalgias [50 (74.62%)] and fever [49 (73.13%)]. Twenty-six patients had underlying predisposing medical conditions. The commonest muscle group involved was iliopsoas muscles in 31 (46.26%) patients. Methicillin-sensitive Staphylococcus aureus was the commonest organism isolated from the pus. Twenty-eight patients developed sepsis and seven died. On univariate analysis, there was a statistically significant association between higher SOFA score, lower Glasgow coma scale, higher pulse rate, lower blood pressure, raised blood urea, raised serum creatinine, higher serum glutamic pyruvate transaminase, raised total bilirubin at presentation, and development of sepsis during hospital stay with mortality. In our study, the patients were seen almost a decade later than those seen in other studies from the region. Evidence of organ dysfunction at presentation and sepsis was associated with increased mortality

Isolating stem cells in the inter-follicular epidermis employing synchrotron radiation-based Fourier-transform infrared microspectroscopy and focal plane array imaging

Normal function and physiology of the epidermis is maintained by the regenerative capacity of this tissue via adult stem cells (SCs). However, definitive identifying markers for SCs remain elusive. Infrared (IR) spectroscopy exploits the ability of cellular biomolecules to absorb in the mid-IR region (\ensuremathλ = 2.5-25 \ensuremathμm), detecting vibrational transitions of chemical bonds. In this study, we exploited the cell's inherent biochemical composition to discriminate SCs of the inter-follicular skin epidermis based on IR-derived markers. Paraffin-embedded samples of human scalp skin (n = 4) were obtained, and 10-\ensuremathμm thick sections were mounted for IR spectroscopy. Samples were interrogated in transmission mode using synchrotron radiation-based Fourier-transform IR (FTIR) microspectroscopy (15 × 15 \ensuremathμm) and also imaged employing globar-source FTIR focal plane array (FPA) imaging (5.4 × 5.4 \ensuremathμm). Dependent on the location of derived spectra, wavenumber-absorbance/intensity relationships were examined using unsupervised principal component analysis. This approach showed clear separation and spectral differences dependent on cell type. Spectral biomarkers concurrently associated with segregation of SCs, transit-amplifying cells and terminally-differentiated cells of epidermis were primarily PO(2)(-) vibrational modes (1,225 and 1,080 cm(-1)), related to DNA conformational alterations. FPA imaging coupled with hierarchical cluster analysis also indicated the presence of specific basal layer cells potentially originating from the follicular bulge, suggested by co-clustering of spectra. This study highlights PO (2) (-) vibrational modes as potential putative SC markers