789 research outputs found
Validating Hemoglobin Saturation and Dissolved Oxygen in Tumors using the OxyLab Probe and Photoacoustic Imaging
The goal of this experiment is to validate the relationship between hemoglobin saturation (SaO2) and partial pressure of dissolved oxygen (pO2) in breast tumors in mice using photoacoustic computed tomographic (PCT) imaging and OxyLite probe, respectively. In its simplest form, the relationship is described by the dissociation curve, or Hill’s equation, for hemoglobin, and is modeled as a sigmoidal curve that is a function of two parameters – the Hill coefficient, n, and the net association constant of HbO2, K (or pO2 at 50% SaO2). First, a calibration study to validate Hill’s equation in blood was performed by creating a closed circuit phantom to test the SaO2 (co-oximeter) and pO2 (Oxylite probe) relationship (K=23.2mmHg and n=2.26). Next, non-invasive localized measurements of SaO2 in MDA-MD-231 and MCF7 breast tumors using PCT spectroscopic methods were compared to pO2 levels, where pO2 levels were measured in 1mm increments across the central axis of the tumor. The fitted results for MCF7 and MDA-MD-231 were K=17.2mmHg and 20.7mmHg, and n=1.76and 1.63, respectively. The results are consistent with sigmoidal form of Hill’s equation. The lower value of K is indicative of the acidic microenvironment associated with tumors. Ongoing work to correct for photon transport and image artifacts are anticipated to enhance the quality of the results. In conclusion, the results from this study demonstrate photoacoustic can be used to measure tumor oxygenation, and its potential use in investigating the effectiveness of anti-angiogenesis therapy
Ambient particulate matter air pollution exposure and mortality in the NIH-AARP diet and health cohort
BACKGROUND: Outdoor fine particulate matter (≤ 2.5 μm; PM2.5) has been identified as a global health threat, but the number of large U.S. prospective cohort studies with individual participant data remains limited, especially at lower recent exposures. OBJECTIVES: We aimed to test the relationship between long-term exposure PM2.5 and death risk from all nonaccidental causes, cardiovascular (CVD), and respiratory diseases in 517,041 men and women enrolled in the National Institutes of Health-AARP cohort. METHODS: Individual participant data were linked with residence PM2.5 exposure estimates across the continental United States for a 2000–2009 follow-up period when matching census tract–level PM2.5 exposure data were available. Participants enrolled ranged from 50 to 71 years of age, residing in six U.S. states and two cities. Cox proportional hazard models yielded hazard ratio (HR) estimates per 10 μg/m3 of PM2.5 exposure. RESULTS: PM2.5 exposure was significantly associated with total mortality (HR = 1.03; 95% CI: 1.00, 1.05) and CVD mortality (HR = 1.10; 95% CI: 1.05, 1.15), but the association with respiratory mortality was not statistically significant (HR = 1.05; 95% CI: 0.98, 1.13). A significant association was found with respiratory mortality only among never smokers (HR = 1.27; 95% CI: 1.03, 1.56). Associations with 10-μg/m3 PM2.5 exposures in yearly participant residential annual mean, or in metropolitan area-wide mean, were consistent with baseline exposure model results. Associations with PM2.5 were similar when adjusted for ozone exposures. Analyses of California residents alone also yielded statistically significant PM2.5 mortality HRs for total and CVD mortality. CONCLUSIONS: Long-term exposure to PM2.5 air pollution was associated with an increased risk of total and CVD mortality, providing an independent test of the PM2.5–mortality relationship in a new large U.S. prospective cohort experiencing lower post-2000 PM2.5 exposure levels. CITATION: Thurston GD, Ahn J, Cromar KR, Shao Y, Reynolds HR, Jerrett M, Lim CC, Shanley R, Park Y, Hayes RB. 2016. Ambient particulate matter air pollution exposure and mortality in the NIH-AARP Diet and Health cohort. Environ Health Perspect 124:484–490; http://dx.doi.org/10.1289/ehp.150967
The effect of Puerariae radix on lipoprotein metabolism in liver and intestinal cells
BACKGROUND: Animal studies investigating the beneficial effects of Puerariae radix on cardiovascular disease have suggested this plant possesses anti-diabetic and lipid lowering properties. However, the exact mechanism by which Puerariae radix affects lipid metabolism is currently unknown. The aim of this study was to investigate the effect of the water extract of Puerariae radix on the secretion of VLDL and chylomicrons from HepG2 liver cells and CaCo2 cells, respectively, in humans. METHODS: The amount of apoB(100 )(a protein marker for VLDL) and apoB(48 )(a protein marker for chylomicrons) in cells and media were quantified by Western Blotting and enhanced chemiluminescence (ECL). Total, free and esterified cholesterol concentrations were measured by gas liquid chromatography. RESULTS: Treatment of cells with water extract of Puerariae radix significantly decreased apoB(100 )production and secretion from HepG2 cells up to 66% in a dose dependent manner. The intracellular total cholesterol and free cholesterol concentration in HepG2 cells also decreased with increasing concentration of the Puerariae radix. In contrast, water extract of Puerariae radix attenuated apoB(48 )concentrations in cells, but not apoB(48 )secretion from CaCo2 enterocytes. CONCLUSIONS: Collectively, our findings suggest that the water extract of Puerariae radix attenuates the hepatic lipoprotein production and secretion. Our present cell culture findings may explain why circulating VLDL and LDL levels were attenuated in animals supplemented with Puerariae radix. Since decreasing the production and secretion of atherogenic lipoproteins decreases the risk of development of cardiovascular disease, diets supplemented with radix may provide a safe and effective beneficial cardioprotective effects in humans
Psychiatric disorders in individuals born very preterm / very low-birth weight: An individual participant data (IPD) meta-analysis
Background: Data on psychiatric disorders in survivors born very preterm (VP; <32 weeks) or very low birthweight (VLBW; <1500 g) are sparse. We compared rates of psychiatric diagnoses between VP/VLBW and term-born, normal birthweight (term/NBW) control participants. /
Methods: This individual participant data (IPD) meta-analysis pooled data from eligible groups in the Adults born Preterm International Collaboration (APIC). Inclusion criteria included: 1) VP/VLBW group (birth weight 2499 g and/or gestational age ≥37 weeks), and 3) structured measure of psychiatric diagnoses using DSM or ICD criteria. Diagnoses of interest were Attention Deficit Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD), Anxiety Disorder, Mood Disorder, Disruptive Behaviour Disorder (DBD), Eating Disorder, and Psychotic Disorder. A systematic search for eligible studies was conducted (PROSPERO Registration Number 47555). /
Findings: Data were obtained from 10 studies (1385 VP/VLBW participants, 1780 controls), using a range of instruments and approaches to assigning diagnoses. Those born VP/VLBW had ten times higher odds of meeting criteria for ASD (odds ratio [OR] 10·6, 95% confidence interval [CI] 2·50, 44·7), five times higher odds of meeting criteria for ADHD (OR 5·42, 95% CI 3·10, 9·46), twice the odds of meeting criteria for Anxiety Disorder (OR 1·91, 95% CI 1·36, 2·69), and 1·5 times the odds of meeting criteria for Mood Disorder (OR 1·51, 95% CI 1·08, 2·12) than controls. This pattern of findings was consistent within age (<18 years vs. ≥18 years) and sex subgroups. /
Interpretation: Our data suggests that individuals born VP/VLBW might have higher odds of meeting criteria for certain psychiatric disorders through childhood and into adulthood than term/NBW controls. Further research is needed to corroborate our results and identify factors associated with psychiatric disorders in individuals born VP/VLBW. /
Funding: Australia's National Health & Medical Research Council; CAPES (Coordenação de Aperfeiçoamento de Pessoal deNÃvel Superior) - International Cooperation General Program; Canadian Institutes of Health Research Team Grant; National Council for Scientific and Technological Development (CNPq); Academy of Finland; Sigrid Juselius Foundation; Signe and Ane Gyllenberg Foundation; European Union's Horizon 2020 research and innovation programme: Project RECAP-Preterm; European Commission Dynamics of Inequality Across the Life-course: structures and processes (DIAL); Neurologic Foundation of New Zealand; MRC programme grant; Health Research Council of New Zealand; National Institutes of Health, USA; The Research Council of Norway; Joint Research Committee between St. Olavs Hospital and Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU); Liaison Committee between Central Norway Regional Health Authority and NTNU
‘Berrypicking’ in the formation of ideas about problem drinking amongst users of alcohol online support groups
Beliefs held by individuals about the illnesses or problems that affect them have been shown to impact upon the health and other outcomes that they achieve. Online support groups (OSGs) are one source of information used by those with health problems which may influence or determine what they think about their particular issue and how to resolve it. Problem drinking remains a major source of significant costs to society. This article explores whether the discussion forums of alcohol OSGs that do not follow the 12-step philosophy of Alcoholics Anonymous influence the formation of these beliefs, reporting on the outcome of thematic analysis of interviews with 25 users from five groups. It argues that Bates’ ‘Berrypicking’ model of information searching is helpful in illuminating group members’ information seeking activities. It looks at the four key aspects of berrypicking identified by Bates – the nature of the search query, the information ‘domains’ drawn on, the information retrieved and the search techniques used. The study finds that users are typically berrypickers, selecting information from different sources and forming their own interpretations
A survey of emergency department use in patients with cyclic vomiting syndrome
<p>Abstract</p> <p>Background</p> <p>Cyclic vomiting syndrome (CVS), a chronic disorder characterized by recurrent episodes of vomiting, is frequently unrecognized and is associated with high utilization of emergency department (ED) services.</p> <p>Methods</p> <p>A web-based survey was posted on the Cyclic Vomiting Syndrome Association (CVSA) website to assess utilization of ED services in patients with CVS.</p> <p>Results</p> <p>Of 251 respondents, 104 (41.4%) were adult CVS patients and 147 (58.6%) were caregivers of pediatric and adult patients. In the adult group, the median number of ED visits for CVS symptoms was 15(range 1 - 200), with a median of 7 ED visits prior to a diagnosis of CVS (range 0 - 150). In the caregiver group, the median number of ED visits was 10 (range 1 - 175) and the median number of ED visits prior to a diagnosis of CVS was 5 (range 0 - 65). CVS was not diagnosed in the ED in 89/104 (93%) adults and 119/147 (93%) patients in the caregiver group. CVS was not recognized in the ED in 84/95 (88%) of adults and 97/122 (80%) of patients in the caregiver group, despite an established diagnosis of CVS.</p> <p>Conclusion</p> <p>There is a sub-group of adult and pediatric CVS patients who are high utilizers of ED services and CVS is not recognized in the ED in the majority of patients. Improved efforts to educate ED physicians are indicated to optimize treatment of patients with CVS and to decrease potential overuse of ED services.</p
Detection of Gamma-Ray Emission from the Starburst Galaxies M82 and NGC 253 with the Large Area Telescope on Fermi
We report the detection of high-energy gamma-ray emission from two starburst
galaxies using data obtained with the Large Area Telescope on board the Fermi
Gamma-ray Space Telescope. Steady point-like emission above 200 MeV has been
detected at significance levels of 6.8 sigma and 4.8 sigma respectively, from
sources positionally coincident with locations of the starburst galaxies M82
and NGC 253. The total fluxes of the sources are consistent with gamma-ray
emission originating from the interaction of cosmic rays with local
interstellar gas and radiation fields and constitute evidence for a link
between massive star formation and gamma-ray emission in star-forming galaxies.Comment: Submitted to ApJ Letter
Fermi Gamma-ray Imaging of a Radio Galaxy
The Fermi Gamma-ray Space Telescope has detected the gamma-ray glow emanating
from the giant radio lobes of the radio galaxy Centaurus A. The resolved
gamma-ray image shows the lobes clearly separated from the central active
source. In contrast to all other active galaxies detected so far in high-energy
gamma-rays, the lobe flux constitutes a considerable portion (>1/2) of the
total source emission. The gamma-ray emission from the lobes is interpreted as
inverse Compton scattered relic radiation from the cosmic microwave background
(CMB), with additional contribution at higher energies from the
infrared-to-optical extragalactic background light (EBL). These measurements
provide gamma-ray constraints on the magnetic field and particle energy content
in radio galaxy lobes, and a promising method to probe the cosmic relic photon
fields.Comment: 27 pages, includes Supplementary Online Material; corresponding
authors: C.C. Cheung, Y. Fukazawa, J. Knodlseder, L. Stawar
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