Advances in structure elucidation of small molecules using mass spectrometry

The structural elucidation of small molecules using mass spectrometry plays an important role in modern life sciences and bioanalytical approaches. This review covers different soft and hard ionization techniques and figures of merit for modern mass spectrometers, such as mass resolving power, mass accuracy, isotopic abundance accuracy, accurate mass multiple-stage MS(n) capability, as well as hybrid mass spectrometric and orthogonal chromatographic approaches. The latter part discusses mass spectral data handling strategies, which includes background and noise subtraction, adduct formation and detection, charge state determination, accurate mass measurements, elemental composition determinations, and complex data-dependent setups with ion maps and ion trees. The importance of mass spectral library search algorithms for tandem mass spectra and multiple-stage MS(n) mass spectra as well as mass spectral tree libraries that combine multiple-stage mass spectra are outlined. The successive chapter discusses mass spectral fragmentation pathways, biotransformation reactions and drug metabolism studies, the mass spectral simulation and generation of in silico mass spectra, expert systems for mass spectral interpretation, and the use of computational chemistry to explain gas-phase phenomena. A single chapter discusses data handling for hyphenated approaches including mass spectral deconvolution for clean mass spectra, cheminformatics approaches and structure retention relationships, and retention index predictions for gas and liquid chromatography. The last section reviews the current state of electronic data sharing of mass spectra and discusses the importance of software development for the advancement of structure elucidation of small molecules

Prognostic relevance of glomerular filtration rate estimation obtained through different equations in hospitalized elderly patients.

The estimated glomerular filtration rate (eGFR) is a predictor of important outcomes and its reduction has been associated with the risk of all-cause mortality in both general population and elderly patients. However while reduced renal function is common in older people, the best method for estimating GFR remains unclear, especially in an acute care setting. Most studies analyzing the accuracy of eGFR in the elderly were carried out in different heterogeneous settings. In this study, we compare the prognostic value of different formulas estimating GFR in predicting the risk of in-hospital morbidity and mortality within 3 months from discharge in elderly hospitalized patients. Data were extracted from "Registro Politerapia Società Italiana di Medicina Interna (REPOSI)". Patients with available creatinine values at hospital admission were selected and eGFR was calculated according to the different formulas: Cockcroft-Gault, Modification of Diet in Renal Disease equation, Chronic Kidney Disease Epidemiology Collaboration, Berlin Initiative Study and Full Age Spectrum. 4621 patients were included in the analysis. Among these, 4.2% and 14.2% died during hospitalization and within 3 months from discharge, respectively. eGFR > 60 ml/min/1.73 m2 at admission was associated with a very low risk of mortality during the hospital stay and within 90 days from discharge, while an eGFR < 60 ml/min/1.73 m2 was associated with unfavorable outcomes, although with a poor level of accuracy (AUC 0.60-0.66). No difference in predictive power between different equations was found. Physicians should be aware of the prognostic role of eGFR in a comprehensive assessment of elderly in-patients