1,973 research outputs found
Influence of Adrenergic Drugs Upon Vital Organ Perfusion During CPR
To determine whether adrenergic drugs administered during cardiopulmonary resuscitation (CPR) alter the distribution of artificial card:l.ac output, we measu red regional blood flow and cardiac output using radioactive microspheres in 12 dogs. Ventricular fibrillation was induced electrically and CPR was immediately begun with a mechanical chest compressor and ventilator (Thurn per ( R) ) at 60 compressions/min, with a ventilation:compression ratio of 1:5, a compression duration of 0.5 sec, and a ventilation pressure of 20 em H 2 o. Compression force was sufficient to develop 40-50 mmHg peak intraesophageal pressure. After 30 sec of CPR, either 0.9% saline vehicle or 50 ug/kg of epinephrine, phenylephrine, or isoproterenol was administered through a central venous catheter. One minute later, microspheres were injected into the left ventricle. After 250 sec of CPR the ventricles were defibrillated electrically. Twenty minute recovery periods were interposed between each drug injection. accord:l.ng Each dog recei.ved to predetermlned all three drugs and saline sequence. Following saline, epinephrine, phenylephrine, and isoproterenol treatment respectively, cardiac output averaged 392, 319, 255, and 475 ml/min; bratn blood flow averaged 37, 54, 2 9 \u27 and 28 ml/min; heart blood flow averaged 25, 79, 26, and IS ml/min; and kidney blood flow averaged 44, 4, 16, and 29 ml/min. Epinephrine improved blood flow t6 the brain, probably because of its alpha adrenergic activity. Epinephrine improved blood flow to the heart during CPR much more than the other agents, probably because of its combined alpha and beta adrenergic activity. This effect may explain its superiority in restoring circulation after prolonged arrest and resuscitation. Isoproterenol should not be used in CPR because it shunts blood away from vital organs
Influence of interposed ventilation pressure upon artificial cardiac output during cardiopulmonary resuscitation in dogs
This study was conducted to determine the effects of high pressure interposed ventilations during cardiopulmonary resuscitation (CPR). Cardiac output was measured by a modified indicator dilution technique in eight anesthetized, intubated mongrel dogs. Positive pressure ventilations (12/min, 80% O2) were interposed after every five chest compressions (performed at 62/min) by a mechanical chest compressor (Thumper®). On repeated trials in the same animal, ventilation pressures from 10-50 cm of H2O were tested in randomized sequence, while the technique of chest compression was held constant. Arterial blood gases immediately after resuscitation were monitored. Increasing ventilation pressure had surprisingly little effect on cardiac output during CPR, although blood gases were profoundly altered. For ventilation pressures of 10, 20, 30, 40, and 50 cm of H2O, producing mean tidal volumes 23, 38, 61, 83, and 94 ml/kg; cardiac output remained nearly constant, averaging 21, 25, 23, 26, and 24 ml/min/kg. Corresponding mean post-resuscitation pH was 7.24, 7.41, 7.51, 7.56, and 7.53; PCO2 was 41, 26, 18, 16, and 15 torr. The post-resuscitation arterial oxygen tension was greater than 100 torr at all ventilation pressures except 10 cm of H2O. Interposed ventilations of pressure and volume more than adequate to prevent acidosis during CPR did not impair artificial cardiac output. If anything, cardiac output was slightly improved by more forceful ventilation
Relationship of blood pressure and flow during CPR to chest compression amplitude: Evidence for an effective compression threshold
This study was conducted to investigate the importance of the depth of chest compression in producing effective cardiopulmonary resuscitation (CPR) in animals, as indicated by cardiac output and mean arterial blood pressure. Cardiac output was measured by a modified indicator dilution technique in 8 anesthetized dogs, 6 to 12 kg body weight, during repeated 2-minute episodes of electrically induced ventricular fibrillation and CPR provided by a mechanical chest compressor and ventilator (Thumper®). Chest compression exceeding a threshold value (x0) between 1.5 and 3.0 cm was required in each animal to produce measurable cardiac output. In particular, cardiac output (CO) was linearly related to chest compression depth (x) by an expression of the form CO = a(x-x0) for x \u3e x0, and CO = 0 for x £ x0. The mean value of x0 was 2.3 cm. A similar threshold for measurable blood pressure was observed in 7 of the 8 dogs, with a mean value of 1.8 cm. For chest compression of 2.5 cm or greater, relatively modest increases in chest compression depth caused relatively large changes in cardiac output
Tracing the Mixing and Movement of Groundwater into Florida Bay with Four Naturally Occurring Radium Isotopes
Proceedings of the 1999 Georgia Water Resources Conference, March 30 and 31, Athens, Georgia.Four naturally occurring isotopes of radium (²²³, ²²⁴, ²²⁶, ²²⁸Ra) have a range in half-life that extends from a few days to over 1,600 years. Unique geochemical attributes make these radium isotopes ideal to examine sediment/water interface exchange processes in coastal waters. Here we present initial radium isotopic data of Florida Bay, a heavily impacted coastal system in south Florida. Florida Bay is a shallow, brackish, semi-enclosed water body that receives most of its limited freshwater supply from the Everglades, principally by surficial water runoff through Trout Creek/Taylor River. Because the entire region is underlain by highly porous Key Largo limestone and due to other hydrologic constraints, there is the possibility that ground water exchange may be significant in Florida Bay. To evaluate the extent of such a subsurface contribution, radium isotopes are being determined in shallow wells, seepage meter sites, and a series of water column samples across the Everglades National Park-Florida Bay boundary. All four radium isotopes were at least an order of magnitude greater in the two shallow well samples than in the water column samples. For example, ²²⁶Ra ranged from about 0.50 dpm L⁻¹ at a salinity of 5 to over 13 dpm L⁻¹ in Well B (salinity = 47.2). Isotopic radium ratios reveal that the well waters (i.e., marine ground water) are geochemically distinct from surficial waters and are regenerated on a time-scale of several days (i.e., ²²⁴Ra/²²³Ra). Results indicate that this radium quartet can be used effectively in Florida Bay to examine the exchange of surficial water and ground water.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202 with partial funding provided by the U.S. Department of Interior, geological Survey, through the Georgia Water Research Insttitute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-397). The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of the University of Georgia or the U.S. Geological Survey or the conference sponsors
Antiangiogenic Effects and Therapeutic Targets of Azadirachta indica Leaf Extract in Endothelial Cells
Azadirachta indica (common name: neem) leaves have been found to possess immunomodulatory, anti-inflammatory and anti-carcinogenic properties. The present study evaluates anti-angiogenic potential of ethanol extract of neem leaves (EENL) in human umbilical vein endothelial cells (HUVECs). Treatment of HUVECs with EENL inhibited VEGF induced angiogenic response in vitro and in vivo. The in vitro proliferation, invasion and migration of HUVECs were suppressed with EENL. Nuclear fragmentation and abnormally small mitochondria with dilated cristae were observed in EENL treated HUVECs by transmission electron microscopy. Genome-wide mRNA expression profiling after treatment with EENL revealed differentially regulated genes. Expression changes of the genes were validated by quantitative real-time polymerase chain reaction. Additionally, increase in the expression of HMOX1, ATF3 and EGR1 proteins were determined by immunoblotting. Analysis of the compounds in the EENL by mass spectrometry suggests the presence of nimbolide, 2′,3′-dehydrosalannol, 6-desacetyl nimbinene and nimolinone. We further confirmed antiproliferative activity of nimbolide and 2′,3′-dehydrosalannol in HUVECs. Our results suggest that EENL by regulating the genes involved in cellular development and cell death functions could control cell proliferation, attenuate the stimulatory effects of VEGF and exert antiangiogenic effects. EENL treatment could have a potential therapeutic role during cancer progression
Dust Morphology and Composition in FU Orionis Systems
FU Orionis stars are a small group of pre–main-sequence stars known for large-amplitude optical variability. These objects also exhibit multiwavelength phenomena suggestive of active accretion from a circumstellar disk. We present high spatial resolution mid-IR imaging and spectroscopy, submillimeter photometry, and 3–4 μm photometry of four FU Ori–class objects, RNO 1B and C, Z CMa, and Par 21, and one object classified as a pre–FU Ori star, V380 Ori. We resolve multiple IR sources and extended emission in the RNO 1B/C system, and we discuss in detail their association with disk activity and the source of the Infrared Astronomical Satellite far-IR and radio maser emission in this field. We derive dust temperatures and masses for all sources and discuss how dust composition and morphology is related to the evolutionary stage of these objects
Redefining and revisiting cost estimates of routine ART care in Zambia: An analysis of ten clinics
INTRODUCTION: Accurate costing is key for programme planning and policy implementation. Since 2011, there have been major changes in eligibility criteria and treatment regimens with price reductions in ART drugs, programmatic changes resulting in clinical task-shifting and decentralization of ART delivery to peripheral health centres making existing evidence on ART care costs in Zambia out-of-date. As decision makers consider further changes in ART service delivery, it is important to understand the current drivers of costs for ART care. This study provides updates on costs of ART services for HIV-positive patients in Zambia.
METHODS: We evaluated costs, assessed from the health systems perspective and expressed in 2016 USD, based on an activity-based costing framework using both top-down and bottom-up methods with an assessment of process and capacity. We collected primary site-level costs and resource utilization data from government documents, patient chart reviews and time-and-motion studies conducted in 10 purposively selected ART clinics.
RESULTS: The cost of providing ART varied considerably among the ten clinics. The average per-patient annual cost of ART service was 59.38 to 130.32 (range: 162.64) using a top-down method. ART drug costs were the main cost driver (67% to 7% of all costs) and are highly sensitive to the types of patient included in the analysis (long-term vs. all ART patients, including those recently initiated) and the data sources used (facility vs. patient level). Missing capacity costs made up 57% of the total difference between the top-down and bottom-up estimates. Variability in cost across the ten clinics was associated with operational characteristics.
CONCLUSIONS: Real-world costs of current routine ART services in Zambia are considerably lower than previously reported estimates and sensitive to operational factors and methods used. We recommend collection and monitoring of resource use and capacity data to periodically update cost estimates
Bostonia: The Boston University Alumni Magazine. Volume 9
Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs
SeaWiFS technical report series. Volume 23: SeaWiFS prelaunch radiometric calibration and spectral characterization
Based on the operating characteristics of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), calibration equations have been developed that allow conversion of the counts from the radiometer into Earth-existing radiances. These radiances are the geophysical properties the instrument has been designed to measure. SeaWiFS uses bilinear gains to allow high sensitivity measurements of ocean-leaving radiances and low sensitivity measurements of radiances from clouds, which are much brighter than the ocean. The calculation of these bilinear gains is central to the calibration equations. Several other factors within these equations are also included. Among these are the spectral responses of the eight SeaWiFS bands. A band's spectral response includes the ability of the band to isolate a portion of the electromagnetic spectrum and the amount of light that lies outside of that region. The latter is termed out-of-band response. In the calibration procedure, some of the counts from the instrument are produced by radiance in the out-of-band region. The number of those counts for each band is a function of the spectral shape of the source. For the SeaWiFS calibration equations, the out-of-band responses are converted from those for the laboratory source into those for a source with the spectral shape of solar flux. The solar flux, unlike the laboratory calibration, approximates the spectral shape of the Earth-existing radiance from the oceans. This conversion modifies the results from the laboratory radiometric calibration by 1-4 percent, depending on the band. These and other factors in the SeaWiFS calibration equations are presented here, both for users of the SeaWiFS data set and for researchers making ground-based radiance measurements in support of Sea WiFS
A controlled study to assess the effects of a Fast Track (FT) service delivery model among stable HIV patients in Lusaka Zambia
Fast Track models—in which patients coming to facility to pick up medications minimize waiting times through foregoing clinical review and collecting pre-packaged medications—present a potential strategy to reduce the burden of treatment. We examine effects of a Fast Track model (FT) in a real-world clinical HIV treatment program on retention to care comparing two clinics initiating FT care to five similar (in size and health care level), standard of care clinics in Zambia. Within each clinic, we selected a systematic sample of patients meeting FT eligibility to follow prospectively for retention using both electronic medical records as well as targeted chart review. We used a variety of methods including Kaplan Meier (KM) stratified by FT, to compare time to first late pick up, exploring late thresholds at >7, >14 and >28 days, Cox proportional hazards to describe associations between FT and late pick up, and linear mixed effects regression to assess the association of FT with medication possession ratio. A total of 905 participants were enrolled with a median age of 40 years (interquartile range [IQR]: 34–46 years), 67.1% were female, median CD4 count was 499 cells/mm3 (IQR: 354–691), and median time on ART was 5 years (IQR: 3–7). During the one-year follow-up period FT participants had a significantly reduced cumulative incidence of being >7 days late for ART pick-up (0.36, 95% confidence interval [CI]: 0.31–0.41) compared to control participants (0.66; 95% CI: 0.57–0.65). This trend held for >28 days late for ART pick-up appointments, at 23% (95% CI: 18%-28%) among intervention participants and 54% (95% CI: 47%-61%) among control participants. FT models significantly improved timely ART pick up among study participants. The apparent synergistic relationship between refill time and other elements of the FT suggest that FT may enhance the effects of extending visit spacing/multi-month scripting alone. ClinicalTrials.gov Identifier: NCT02776254 https://clinicaltrials.gov/ct2/show/NCT02776254
- …