Nontargeted Mass Spectrometry of Dried Blood Spots for Interrogation of the Human Circulating Metabolome

Advances in high resolution, nontargeted mass spectrometry allow for the simultaneous measure of thousands of metabolites in a single biosample. Application of these analytical approaches to population-scale human studies has been limited by the need for resource-intensive blood sample collection, preparation, and storage. Dried blood spotting, a technique developed decades ago for newborn screening, may offer a simple approach to overcome barriers in human blood acquisition and storage. In this study, we find that over 4,000 spectral features across diverse chemical classes may be efficiently and reproducibly extracted and relatively quantified from human dried blood spots using nontargeted mass spectrometry-based metabolomics. Moreover, over 80% of metabolites were found to be chemically stable in dried blood spots stored at room temperature for up to a week. In direct relation to plasma samples, dried blood spots exhibited comparable representation of the human circulating metabolome, capturing both known and previously uncharacterized metabolites. Dried blood spot approaches provide an opportunity for rapid and facile human biosampling and storage, and will enable widespread metabolomics study of populations, particularly in resource-limited areas.

Nontargeted Mass Spectrometry of Dried Blood Spots for Interrogation of the Human Circulating Metabolome

Advances in high resolution, nontargeted mass spectrometry allow for the simultaneous measure of thousands of metabolites in a single biosample. Application of these analytical approaches to population-scale human studies has been limited by the need for resource-intensive blood sample collection, preparation, and storage. Dried blood spotting, a technique developed decades ago for newborn screening, may offer a simple approach to overcome barriers in human blood acquisition and storage. In this study, we find that over 4,000 spectral features across diverse chemical classes may be efficiently and reproducibly extracted and relatively quantified from human dried blood spots using nontargeted mass spectrometry-based metabolomics. Moreover, over 80% of metabolites were found to be chemically stable in dried blood spots stored at room temperature for up to a week. In direct relation to plasma samples, dried blood spots exhibited comparable representation of the human circulating metabolome, capturing both known and previously uncharacterized metabolites. Dried blood spot approaches provide an opportunity for rapid and facile human biosampling and storage, and will enable widespread metabolomics study of populations, particularly in resource-limited areas.

New and old roles for narrowband Hα

Until recently, Hα has been seen as the tracer of ionized gas, picking out both star formation and the late stages of stellar evolution. This has been reaffirmed, spectacularly, by the recent WHAM and SHS surveys. But the advent of large-area digital detectors creates a new role for narrowband Hα as a direct, simultaneous, measure of intrinsic stellar colour and reddening when e.g. r'-Hα is combined with a nearby broad band colour e.g. r'- i'. This new capability has been clearly demonstrated by the nearly-complete IPHAS survey.

Parallel Reliability of Lumbar-Flexion Measurements

Context:Research and clinical recordings of lumbar flexion demand practicable and precise methodology for quantifying variations.Objective:To describe and evaluate the parallel reliability of 2 methods of measuring lumbar fexion—perpendicular stick markers (SM) and the distanciometer (DM)—using an electrogoniometer (EGM) as reference.Design:Parallel measurement for reliability.Setting:Laboratory.Participants:25 healthy men.Intervention:Simultaneous measure of lumbar flexion at preestablished positions (0°, 15°, 30°, and 45°).Outcome Measures:Data from SM and DM, recorded simultaneously.Results:High parallel reliability was found when comparing the EGM data with the SM (r= .997; measurement error: 0.6° ± 0.7°; no differences:t-testP= .260) and with the DM (r= .962; measurement error: 2.8° ± 1.9°; no differences:t-testP= .973).Conclusions:Considering the reliability, practicability, and low cost of the described methods, they can be regarded as applicable and useful.

Simultaneous Measure of General Activity and Exploratory Behavior

Housemice of five strains were tested repeatedly in a runway apparatus so arranged that both dimensions of gross activity could be measured. Exploratory performances showed the expected decline both within and among days of testing. On the other hand, general activity did not decrease among days. Moreover, the magnitude of correlation between the two behaviors was minimal except for one strain. These data are construed as definitive in establishing the separateness of the two categories of gross activity: general activity and exploratory behavior. Moreover, these data indicate that maze learning drug response differences reported for these strains cannot be explained by differences in activity variables.