747 research outputs found
Functional Blockade of E-Selectin in Tumor-Associated Vessels Enhances Anti-Tumor Effect of Doxorubicin in Breast Cancer
Chemotherapy is a mainstay of treatment for solid tumors. However, little is known about how therapy-induced immune cell infiltration may affect therapy response. We found substantial CD45+ immune cell density adjacent to E-selectin expressing inflamed vessels in doxorubicin (DOX)-treated residual human breast tumors. While CD45 level was significantly elevated in DOX-treated wildtype mice, it remained unchanged in DOX-treated tumors from E-selectin null mice. Similarly, intravenous administration of anti-E-selectin aptamer (ESTA) resulted in a significant reduction in CD45+ immune cell density in DOX-treated residual tumors, which coincided with a delay in tumor growth and lung metastasis in MMTV-pyMT mice. Additionally, both tumor infiltrating T-lymphocytes and tumor associated-macrophages were skewed towards TH2 in DOX-treated residual breast tumors; however, ESTA suppressed these changes. This study suggests that DOX treatment instigates de novo intratumoral infiltration of immune cells through E-selectin, and functional blockade of E-selectin may reduce residual tumor burden as well as metastasis through suppression of TH2 shift
Anti-TNF-α antibody allows healing of joint damage in polyarthritic transgenic mice
Anti-tumor-necrosis-factor-α (TNF-α) monoclonal antibody was used to treat Tg197 transgenic mice, which constitutively produce human TNF-α (hTNF-α) and develop a progressive polyarthritic disease. Treatment of both young (7- or 8-week-old) and aged (27- or 28-week-old) mice commenced when at least two limbs showed signs of moderate to severe arthritis. The therapeutic efficacy of anti-TNF-α antibody was assessed using various pathological indicators of disease progression. The clinical severity of arthritis in Tg197 mice was significantly reduced after anti-TNF-α treatment in comparison with saline-treated mice and in comparison with baseline assessments in both young and aged mice. The treatment with anti-TNF-α prevented loss of body weight. Inflammatory pathways as reflected by elevated circulating hTNF-α and local expression of various proinflammatory mediators were all diminished by anti-TNF-α treatment, confirming a critical role of hTNF-α in this model of progressive polyarthritis. More importantly, the amelioration of the disease was associated with reversal of existing structural damage, including synovitis and periosteal bone erosions evident on histology. Repair of cartilage was age dependent: reversal of cartilage degradation after anti-TNF-α treatment was observed in young mice but not in aged mice
Cross-hemispheric transport of Central African biomass burning pollutants: implications for downwind ozone production
Pollutant plumes with enhanced concentrations of trace gases and aerosols were observed over the southern coast of West Africa during August 2006 as part of the AMMA wet season field campaign. Plumes were observed both in the mid and upper troposphere. In this study we examined the origin of these pollutant plumes, and their potential to photochemically produce ozone (O3) downwind over the Atlantic Ocean. Their possible contribution to the Atlantic O3 maximum is also discussed. Runs using the BOLAM mesoscale model including biomass burning carbon monoxide (CO) tracers were used to confirm an origin from central African biomass burning fires. The plumes measured in the mid troposphere (MT) had significantly higher pollutant concentrations over West Africa compared to the upper tropospheric (UT) plume. The mesoscale model reproduces these differences and the two different pathways for the plumes at different altitudes: transport to the north-east of the fire region, moist convective uplift and transport to West Africa for the upper tropospheric plume versus north-west transport over the Gulf of Guinea for the mid-tropospheric plume. Lower concentrations in the upper troposphere are mainly due to enhanced mixing during upward transport. Model simulations suggest that MT and UT plumes are 16 and 14 days old respectively when measured over West Africa. The ratio of tracer concentrations at 600 hPa and 250 hPa was estimated for 14â15 August in the region of the observed plumes and compares well with the same ratio derived from observed carbon dioxide (CO2) enhancements in both plumes. It is estimated that, for the period 1â15 August, the ratio of Biomass Burning (BB) tracer concentration transported in the UT to the ones transported in the MT is 0.6 over West Africa and the equatorial South Atlantic.
Runs using a photochemical trajectory model, CiTTyCAT, initialized with the observations, were used to estimate in-situ net photochemical O3 production rates in these plumes during transport downwind of West Africa. The mid-troposphere plume spreads over altitude between 1.5 and 6 km over the Atlantic Ocean. Even though the plume was old, it was still very photochemically active (mean net O3 production rates over 10 days of 2.6 ppbv/day and up to 7 ppbv/day during the first days) above 3 km especially during the first few days of transport westward. It is also shown that the impact of high aerosol loads in the MT plume on photolysis rates serves to delay the peak in modelled O3 concentrations. These results suggest that a significant fraction of enhanced O3 in mid-troposphere over the Atlantic comes from BB sources during the summer monsoon period. According to simulated occurrence of such transport, BB may be the main source for O3 enhancement in the equatorial south Atlantic MT, at least in August 2006. The upper tropospheric plume was also still photochemically active, although mean net O3 production rates were slower (1.3 ppbv/day). The results suggest that, whilst the transport of BB pollutants to the UT is variable (as shown by the mesoscale model simulations), pollution from biomass burning can make an important contribution to additional photochemical production of O3 in addition to other important sources such as nitrogen oxides (NOx) from lightning
Luminosities and mass-loss rates of SMC and LMC AGB stars and Red Supergiants
(Abridged) Dust radiative transfer models are presented for 101 carbon stars
and 86 oxygen-rich evolved stars in the Magellanic Clouds for which 5-35 \mum\
{\it Spitzer} IRS spectra are available. The spectra are complemented with
available optical and infrared photometry to construct the spectral energy
distribution. A minimisation procedure is used to fit luminosity, mass-loss
rate and dust temperature at the inner radius. Different effective temperatures
and dust content are also considered. Periods from the literature and from new
OGLE-III data are compiled and derived. The O-rich stars are classified in
foreground objects, AGB stars and Red Super Giants.
For the O-rich stars silicates based on laboratory optical constants are
compared to "astronomical silicates". Overall, the grain type by Volk & Kwok
(1988) fit the data best. However, the fit based on laboratory optical
constants for the grains can be improved by abandoning the small-particle
limit. The influence of grain size, core-mantle grains and porosity are
explored.
Relations between mass-loss rates and luminosity and pulsation period are
presented and compared to the predictions of evolutionary models, those by
Vassiliadis & Wood (1993) and their adopted mass-loss recipe, and those based
on a Reimers mass-loss law with a scaling of a factor of five. The Vassiliadis
& Wood models describe the data better, although there are also some
deficiencies, in particular to the maximum adopted mass-loss rate.
The OGLE-III data reveal an O-rich star in the SMC with a period of 1749
days. Its absolute magnitude of makes it a good candidate
for a super-AGB star.Comment: A&A accepte
The Role of Parvalbumin-positive Interneurons in Auditory Steady-State Response Deficits in Schizophrenia
© The Author(s) 2019. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the articleâs Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the articleâs Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Despite an increasing body of evidence demonstrating subcellular alterations in parvalbumin-positive (PV+) interneurons in schizophrenia, their functional consequences remain elusive. Since PV+ interneurons are involved in the generation of fast cortical rhythms, these changes have been hypothesized to contribute to well-established alterations of beta and gamma range oscillations in patients suffering from schizophrenia. However, the precise role of these alterations and the role of different subtypes of PV+ interneurons is still unclear. Here we used a computational model of auditory steady-state response (ASSR) deficits in schizophrenia. We investigated the differential effects of decelerated synaptic dynamics, caused by subcellular alterations at two subtypes of PV+ interneurons: basket cells and chandelier cells. Our simulations suggest that subcellular alterations at basket cell synapses rather than chandelier cell synapses are the main contributor to these deficits. Particularly, basket cells might serve as target for innovative therapeutic interventions aiming at reversing the oscillatory deficits.Peer reviewe
Antiepileptic drugsâ tolerability and safety â a systematic review and meta-analysis of adverse effects in dogs
<p>Various anti-epileptic drugs (AEDs) are used for the management of idiopathic epilepsy (IE) in dogs. Their safety profile is an important consideration for regulatory bodies, owners and prescribing clinicians. However, information on their adverse effects still remains limited with most of it derived from non-blinded non-randomized uncontrolled trials and case reports.</p><p><span>This poster won third place, which was presented at the Veterinary Evidence Today conference, Edinburgh November 1-3, 2016. </span></p><br /> <img src="https://www.veterinaryevidence.org/rcvskmod/icons/oa-icon.jpg" alt="Open Access" /
Newly detected ozone-depleting substances in the atmosphere
Ozone-depleting substances emitted through human activitiescause large-scale damage to the stratospheric ozone layer, and influence global climate. Consequently, the production of many of these substances has been phased out; prominent examples are the chlorofluorocarbons (CFCs), and their intermediate replacements, the hydrochlorofluorocarbons (HCFCs). So far,
seven types of CFC and six types of HCFC have been shown to contribute to stratospheric ozone destruction 1,2. Here, we report the detection and quantification of a further three CFCs and one HCFC. We analysed the composition of unpolluted air samples collected in Tasmania between 1978 and 2012, and extracted from deep firn snow in Greenland in 2008, using gas
chromatography with mass spectrometric detection. Using the firn data, we show that all four compounds started to emerge in the atmosphere in the 1960s. Two of the compounds continue to accumulate in the atmosphere. We estimate that, before 2012, emissions of all four compounds combined amounted to more than 74,000 tonnes. This is small compared with peak
emissions of other CFCs in the 1980s of more than one million tonnes each year 2. However, the reported emissions are clearly contrary to the intentions behind the Montreal Protocol, and raise questions about the sources of these gases
Applying strategies from libertarian paternalism to decision making for prostate specific antigen (PSA) screening
<p>Abstract</p> <p>Background</p> <p>Despite the recent publication of results from two randomized clinical trials, prostate specific antigen (PSA) screening for prostate cancer remains a controversial issue. There is lack of agreement across studies that PSA screening significantly reduces prostate cancer mortality. In spite of these facts, the widespread use of PSA testing in the United States leads to overdetection and overtreatment of clinically indolent prostate cancer, and its associated harms of incontinence and impotence.</p> <p>Discussion</p> <p>Given the inconclusive results from clinical trials and incongruent PSA screening guidelines, the decision to screen for prostate cancer with PSA testing is an uncertain one for patients and health care providers. Screening guidelines from some health organizations recommend an informed decision making (IDM) or shared decision making (SDM) approach for deciding on PSA screening. These approaches aim to empower patients to choose among the available options by making them active participants in the decision making process. By increasing involvement of patients in the clinical decision-making process, IDM/SDM places more of the responsibility for a complex decision on the patient. Research suggests, however, that patients are not well-informed of the harms and benefits associated with prostate cancer screening and are also subject to an assortment of biases, emotion, fears, and irrational thought that interferes with making an informed decision. In response, the IDM/SDM approaches can be augmented with strategies from the philosophy of libertarian paternalism (LP) to improve decision making. LP uses the insights of behavioural economics to help people better make better choices. Some of the main strategies of LP applicable to PSA decision making are a default decision rule, framing of decision aids, and timing of the decision. In this paper, we propose that applying strategies from libertarian paternalism can help with PSA screening decision-making.</p> <p>Summary</p> <p>Our proposal to augment IDM and SDM approaches with libertarian paternalism strategies is intended to guide patients toward a better decision about testing while maintaining personal freedom of choice. While PSA screening remains controversial and evidence conflicting, a libertarian-paternalism influenced approach to decision making can help prevent the overdiagnosis and overtreatment of prostate cancer.</p
Measurement of Angular Distributions and R= sigma_L/sigma_T in Diffractive Electroproduction of rho^0 Mesons
Production and decay angular distributions were extracted from measurements
of exclusive electroproduction of the rho^0(770) meson over a range in the
virtual photon negative four-momentum squared 0.5< Q^2 <4 GeV^2 and the
photon-nucleon invariant mass range 3.8< W <6.5 GeV. The experiment was
performed with the HERMES spectrometer, using a longitudinally polarized
positron beam and a ^3He gas target internal to the HERA e^{+-} storage ring.
The event sample combines rho^0 mesons produced incoherently off individual
nucleons and coherently off the nucleus as a whole. The distributions in one
production angle and two angles describing the rho^0 -> pi+ pi- decay yielded
measurements of eight elements of the spin-density matrix, including one that
had not been measured before. The results are consistent with the dominance of
helicity-conserving amplitudes and natural parity exchange. The improved
precision achieved at 47 GeV,
reveals evidence for an energy dependence in the ratio R of the longitudinal to
transverse cross sections at constant Q^2.Comment: 15 pages, 15 embedded figures, LaTeX for SVJour(epj) document class
Revision: Fig. 15 corrected, recent data added to Figs. 10,12,14,15; minor
changes to tex
- âŠ