238 research outputs found
A test of positive suggestions about side effects as a way of enhancing the analgesic response to NSAIDs
Side effects are frequent in pharmacological pain management, potentially preceding analgesia and limiting drug tolerability. Discussing side effects is part of informed consent, yet can favor nocebo effects. This study aimed to test whether a positive suggestion regarding side effects, which could act as reminders of the medication having been absorbed, might favor analgesia in a clinical interaction model. Sixty-six healthy males participated in a study “to validate pupillometry as an objective measure of analgesia”. Participants were unknowingly randomized double-blind to positive vs control information about side effects embedded in a video regarding the study drugs. Sequences of moderately painful heat stimuli applied before and after treatment with diclofenac and atropine served to evaluate analgesia. Atropine was deceptively presented as a co-analgesic, but used to induce side effects. Adverse events (AE) were collected with the General Assessment of Side Effects (GASE) questionnaire prior to the second induced pain sequence. Debriefing fully informed participants regarding the purpose of the study and showed them the two videos.The combination of medication led to significant analgesia, without a between-group difference. Positive information about side effects increased the attribution of AE to the treatment compared to the control information. The total GASE score was correlated with analgesia, i.e., the more AEs reported, the stronger the analgesia. Interestingly, there was a significant between-groups difference on this correlation: the GASE score and analgesia correlated only in the positive information group. This provides evidence for a selective link between AEs and pain relief in the group who received the suggestion that AEs could be taken as a sign “that help was on the way”. During debriefing, 65% of participants said they would prefer to receive the positive message in a clinical context. Although the present results cannot be translated immediately to clinical pain conditions, they do indicate the importance of testing this type of modulation in a clinical context
Gonadal Malformations in Whitefish from Lake Thun: Defining the Case and Evaluating the Role of EDCs
The objectives of this project were to evaluate i) whether the gonad alterations of whitefish (Coregonus lavaretus spp.) in Lake Thun represent abnormal morphological variations specific to this lake, and, if so, ii) whether the malformations are related to chemical exposure,
in particular to exposure to endocrine-disrupting compounds (EDCs). Large-scale monitoring data revealed that, although whitefish in other lakes display some background variation of gonad morphology, the situation in Lake Thun, is unique because of the significantly higher prevalence of gonad
malformations. The abnormal variations of whitefish gonad morphology include aplasias, compartmentations, fusions, and intersex. In the search for the factor(s) causing the gonad malformations, coregonids were exposed from fertilization up to maturity to Lake Thun water and plankton or to
contaminants possibly being present in the lake, including trinitrotoluenes, and naphtalene sulfonates. Since these experiments are still ongoing, a conclusive answer cannot be given yet, but initial observations point to a role of the lake plankton. The possible presence of EDCs in Lake Thun
was assessed using bioanalytics and biomarkers. The bioanalytical studies found estrogenic activities in concentrated plankton extracts of Lake Thun, however, estrogenic activities occurred also in plankton extracts of reference lakes. Bioassay-directed fractionation of the plankton samples
points to degradation products of natural substances as a cause of the estrogenic activity. Examination of Lake Thun whitefish for EDC biomarkers such as vitellogenin, sex steroid levels or intersex frequency yielded no indications of exposure to EDCs, neither in fish with normal nor in fish
with abnormal gonad morphology. Long-term laboratory exposure of developing coregonids to the prototype estrogenic compound, 17?-estradiol, resulted in an increased frequency of intersex gonads, but did not induce the other gonad malformations typical for Lake Thun coregonids. In summing
up, the currently available evidence does not support an EDC or chemical etiology of the gonad malformations, however, this preliminary conclusion needs to be substantiated in the ongoing investigations. The project also highlights the need for more detailed knowledge of natural variation
in wildlife populations to be able to recognize anthropogenically caused variation
Large A-fiber activity is required for microglial proliferation and p38 MAPK activation in the spinal cord: different effects of resiniferatoxin and bupivacaine on spinal microglial changes after spared nerve injury
BACKGROUND: After peripheral nerve injury, spontaneous ectopic activity arising from the peripheral axons plays an important role in inducing central sensitization and neuropathic pain. Recent evidence indicates that activation of spinal cord microglia also contributes to the development of neuropathic pain. In particular, activation of p38 mitogen-activated protein kinase (MAPK) in spinal microglia is required for the development of mechanical allodynia. However, activity-dependent activation of microglia after nerve injury has not been fully addressed. To determine whether spontaneous activity from C- or A-fibers is required for microglial activation, we used resiniferatoxin (RTX) to block the conduction of transient receptor potential vanilloid subtype 1 (TRPV1) positive fibers (mostly C- and Adelta-fibers) and bupivacaine microspheres to block all fibers of the sciatic nerve in rats before spared nerve injury (SNI), and observed spinal microglial changes 2 days later. RESULTS: SNI induced robust mechanical allodynia and p38 activation in spinal microglia. SNI also induced marked cell proliferation in the spinal cord, and all the proliferating cells (BrdU+) were microglia (Iba1+). Bupivacaine induced a complete sensory and motor blockade and also significantly inhibited p38 activation and microglial proliferation in the spinal cord. In contrast, and although it produced an efficient nociceptive block, RTX failed to inhibit p38 activation and microglial proliferation in the spinal cord. CONCLUSION: (1) Blocking peripheral input in TRPV1-positive fibers (presumably C-fibers) is not enough to prevent nerve injury-induced spinal microglial activation. (2) Peripheral input from large myelinated fibers is important for microglial activation. (3) Microglial activation is associated with mechanical allodynia
Machine-learning assessed abdominal aortic calcification is associated with long-term fall and fracture risk in community-dwelling older Australian women
Abdominal aortic calcification (AAC), a recognized measure of advanced vascular disease, is associated with higher cardiovascular risk and poorer long-term prognosis. AAC can be assessed on dual-energy X-ray absorptiometry (DXA)-derived lateral spine images used for vertebral fracture assessment at the time of bone density screening using a validated 24-point scoring method (AAC-24). Previous studies have identified robust associations between AAC-24 score, incident falls, and fractures. However, a major limitation of manual AAC assessment is that it requires a trained expert. Hence, we have developed an automated machine-learning algorithm for assessing AAC-24 scores (ML-AAC24). In this prospective study, we evaluated the association between ML-AAC24 and long-term incident falls and fractures in 1023 community-dwelling older women (mean age, 75 ± 3 years) from the Perth Longitudinal Study of Ageing Women. Over 10 years of follow-up, 253 (24.7%) women experienced a clinical fracture identified via self-report every 4–6 months and verified by X-ray, and 169 (16.5%) women had a fracture hospitalization identified from linked hospital discharge data. Over 14.5 years, 393 (38.4%) women experienced an injurious fall requiring hospitalization identified from linked hospital discharge data. After adjusting for baseline fracture risk, women with moderate to extensive AAC (ML-AAC24 ≥ 2) had a greater risk of clinical fractures (hazard ratio [HR] 1.42; 95% confidence interval [CI], 1.10–1.85) and fall-related hospitalization (HR 1.35; 95% CI, 1.09–1.66), compared to those with low AAC (ML-AAC24 ≤ 1). Similar to manually assessed AAC-24, ML-AAC24 was not associated with fracture hospitalizations. The relative hazard estimates obtained using machine learning were similar to those using manually assessed AAC-24 scores. In conclusion, this novel automated method for assessing AAC, that can be easily and seamlessly captured at the time of bone density testing, has robust associations with long-term incident clinical fractures and injurious falls. However, the performance of the ML-AAC24 algorithm needs to be verified in independent cohorts. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR)
Search for a Higgs Boson Decaying into Two Photons at LEP
A Higgs particle produced in association with a Z boson and decaying into two
photons is searched for in the data collected by the L3 experiment at LEP. All
possible decay modes of the Z boson are investigated. No signal is observed in
447.5 pb^-1 of data recorded at centre-of-mass energies up to 209 GeV. Limits
on the branching fraction of the Higgs boson decay into two photons as a
function of the Higgs mass are derived. A lower limit on the mass of a
fermiophobic Higgs boson is set at 105.4 GeV at 95% confidence level
Formation of the in Two-Photon Collisions at LEP
The two-photon width of the meson has been
measured with the L3 detector at LEP. The is studied in the decay
modes , KK, KK,
KK, , , and
using an integrated luminosity of 140 pb at GeV and
of 52 pb at GeV. The result is
(BR) keV. The dependence of the cross section is studied for
GeV. It is found to be better described by a Vector Meson
Dominance model form factor with a J-pole than with a -pole. In addition,
a signal of events is observed at the mass. Upper limits
for the two-photon widths of the , , and are also
given
K0s K0s Final State in Two-Photon Collisions and Implications for Glueballs
The K0s K0s final state in two-photon collisions is studied with the L3
detector at LEP. The mass spectrum is dominated by the formation of the
f_2'(1525) tensor meson in the helicity-two state with a two-photon width times
the branching ratio into K Kbar of 76 +- 6 +- 11 eV. A clear signal for the
formation of the f_J(1710) is observed and it is found to be dominated by the
spin-two helicity-two state. No resonance is observed in the mass region around
2.2 GeV and an upper limit of 1.4 eV at 95% C.L. is derived for the two-photon
width times the branching ratio into K0s K0s for the glueball candidate
xi(2230)
Study of Z Boson Pair Production in e+e- Collisions at LEP at \sqrt{s}=189 GeV
The pair production of Z bosons is studied using the data collected by the L3
detector at LEP in 1998 in e+e- collisions at a centre-of-mass energy of 189
GeV. All the visible final states are considered and the cross section of this
process is measured to be 0.74 +0.15 -0.14 (stat.) +/- 0.04 (syst.) pb. Final
states containing b quarks are enhanced by a dedicated selection and their
production cross section is found to be 0.18 +0.09 -0.07 (stat.) +/- 0.02
(syst.) pb. Both results are in agreement with the Standard Model predictions.
Limits on anomalous couplings between neutral gauge bosons are derived from
these measurements
Study of Z Boson Pair Production in e^+e^- Interactions at \sqrt{s}=192 - 202 GeV
The cross section for the production of Z boson pairs is measured using the
data collected by the L3 detector at LEP in 1999 in e^+e^- collisions at
centre-of-mass energies ranging from 192 GeV up to 202 GeV. Events in all the
visible final states are selected, measuring the cross section of this process.
The special case of final states containing b quarks is also investigated. All
results are in agreement with the Standard Model predictions
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