93 research outputs found

    Resonant inelastic x-ray scattering (RIXS) spectra of magnesium diboride

    Full text link
    Using the tight-binding linear muffin-tin orbitals method, the soft x-ray fluorescence K-emission spectra of boron in MgB_2, excited close to the absorption edge, are estimated. In the calculations the angle of incidence between the direction of the incoming photon and the hexagonal axis of the specimen is 60 degrees and 75 degrees. Comparison with experiment is possible in the former case where good agreement is found. Furthermore, another resonant feature below the Fermi energy is predicted for the larger angle. This feature can be related to the excitations to the antibonding B pi-band in the neighbourhood of the L-H line in the Brillouin zone.Comment: 4 pages with 4 figure

    Stereospecific modulation of GABA(A) receptor function by urocanic acid isomers

    Get PDF
    A deamination product of histidine, urocanic acid, accumulates in the skin of mammals as trans-urocanic acid. Ultraviolet (UV) irradition converts it to the cis-isomer that is an important mediator in UV-induced immunosuppression. We have recently shown that urocanic acid interferes with the agonist binding to GABAA receptors. We now report that the effects of urocanic acid on binding of a convulsant ligand (t-butylbicyclo[35S]phosphorothionate) to GABAA receptors in brain membrane homogenates are dependent on pH of the incubation medium, the agonistic actions being enhanced at the normal pH of the skin (5.5). Using Xenopus laevis oocytes expressing recombinant rat alpha1beta1gamma2S GABAA receptors, the low pH potentiated the direct agonistic action of trans-urocanic acid under two-electrode voltage-clamp, whereas cis-urocanic acid retained its low efficacy both at pH 5.5 and 7.4. The results thus indicate clear differences between urocanic acid isomers in functional activity at one putative receptor site of immunosuppression, the GABAA receptor, the presence of which in the skin remains to be demonstrated.</p

    Thyroid function test variability and cardiovascular morbidity in hyperthyroidism

    Get PDF
    Objective: The variability of thyroid function tests (TFTs) during antithyroid drug (ATD) therapy and its association with adverse health outcomes have not been previously studied. The aim of this study was to evaluate the association of TFT variability and cardiovascular morbidity during ATD therapy. Design: Retrospective cohort study. Patients and Measurements: Hyperthyroid patients (n = 394) treated with ATD therapy at Tampere University Hospital between March 2016 and December 2018 were followed up for a median time of 1.5 years (interquartile range 0.8–2.0). The coefficients of variation (CVs) of the follow-up thyroid-stimulating hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3) measurements were determined. The associations of TFT variability and baseline clinical factors with cardiovascular disease (CVD) -associated hospital visits were assessed with logistic regression analyses. Results: In the multivariable analyses, age (odds ratio [OR]: 1.06, 95% confidence interval [CI]: 1.03–1.09), male gender (OR: 2.33, 95% CI: 1.03–5.28) and fT4-CV (OR: 1.02, 95% CI: 1.01–1.04) were independent risk factors for cardiovascular morbidity, whereas baseline positive thyrotropin receptor antibodies (TRAbs) were associated with lower cardiovascular morbidity (OR: 0.29, 95% CI: 0.14–0.61). When the patients with baseline TRAb positivity were studied separately, fT4-CV was associated with cardiovascular morbidity (OR: 1.03, 95% CI: 1.00–1.05). Conclusions: During ATD therapy, fT4 variability is associated with an increased cardiovascular morbidity. Although positive TRAbs are associated with a lower cardiovascular morbidity compared with hyperthyroidism with negative autoantibodies, the variability of fT4 is associated with cardiovascular morbidity also in patients with positive TRAbs.Peer reviewe

    Molecular targets for the protodynamic action of cis-urocanic acid in human bladder carcinoma cells

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>cis-urocanic acid (cis-UCA) is an endogenous amino acid metabolite capable of transporting protons from the mildly acidic extracellular medium into the cell cytosol. The resulting intracellular acidification suppresses many cellular activities. The current study was aimed at characterizing the molecular mechanisms underlying cis-UCA-mediated cytotoxicity in cultured cancer cells.</p> <p>Methods</p> <p>5367 bladder carcinoma cells were left untreated or treated with cis-UCA. Cell death was assessed by measuring caspase-3 activity, mitochondrial membrane polarization, formation and release of cytoplasmic histone-associated DNA fragments, and cellular permeabilization. Cell viability and metabolic activity were monitored by colorimetric assays. Nuclear labelling was used to quantify the effects of cis-UCA on cell cycle. The activity of the ERK and JNK signalling pathways was studied by immunoblotting with specific antibodies. Phosphatase activity in cis-UCA-treated cells was determined by assay kits measuring absorbance resulting from the dephosphorylation of an artificial substrate. All statistical analyses were performed using the two-way Student's t-test (p < 0.05).</p> <p>Results</p> <p>Here we report that treatment of the 5637 human bladder carcinoma cells with 2% cis-UCA induces both apoptotic and necrotic cell death. In addition, metabolic activity of the 5637 cells is rapidly impaired, and the cells arrest in cell cycle in response to cis-UCA. Importantly, we show that cis-UCA promotes the ERK and JNK signalling pathways by efficiently inhibiting the activity of serine/threonine and tyrosine phosphatases.</p> <p>Conclusions</p> <p>Our studies elucidate how cis-UCA modulates several cellular processes, thereby inhibiting the proliferation and survival of bladder carcinoma cells. These anti-cancer effects make cis-UCA a potential candidate for the treatment of non-muscle invasive bladder carcinoma.</p

    Three Randomised Phase I/IIa Trials of 5% Cis-urocanic Acid Emulsion Cream in Healthy Adult Subjects and in Patients with Atopic Dermatitis

    Get PDF
    New treatment modalities are needed in atopic dermatitis. We evaluated the pharmacokinetics, safety, tolerability, and efficacy of topical cis-urocanic acid (cis-UCA) cream in randomised vehicle-controlled double-blinded clinical trials. The subjects received 5% cis-UCA emulsion cream and control vehicle on volar forearms after right–left randomisation. Study 1: 16 healthy subjects received one dose on the skin and, a week later, on DMSO-irritated skin. Study 2: 16 healthy subjects received 2 daily doses for 10 days. Study 3: 13 patients with mild to moderate disease were treated on selected skin lesions twice daily for 28 days. Study treatments were well tolerated. cis-UCA remained close to endogenous levels in plasma and urine. cis-UCA reduced transepidermal water loss (TEWL) both in healthy subjects and in the patients. Eczema area severity index and physician’s global assessment improved from baseline with both treatments. cis-UCA cream improved skin barrier function and suppressed inflammation in the human skin

    Effects of a sea buckthorn oil spray emulsion on dry eye

    Get PDF
    PurposeTo investigate the effects of a sea buckthorn oil and sodium hyaluronate-containing eyelid spray emulsion (SB spray) on dry eye.MethodsA randomized controlled study was carried out. Adults (25–70 years) with Ocular Surface Disease Index (OSDI) ≥20 and moderate or severe dryness, burning or grittiness of the eyes were included. In study part one (n = 2), SB spray was used on both closed eyelids four times in one day. In part two (n = 10), SB spray was used on one randomized eyelid, and a commercial reference spray on the other for nine days. In part three (n = 40), eyes were randomized to one eye receiving SB spray and an untreated control for 1.5 months. Dry eye tests were carried out at baseline, during, and at the end of each study section. Symptoms were recorded in questionnaires and daily logs.ResultsIn part one, the SB spray was well tolerated. In part two, OSDI decreased significantly (P = 0.022) in the SB spray eye compared to the reference spray, indicating a beneficial effect on symptoms. In part three, OSDI in the SB spray eye decreased significantly compared to the untreated control (P = 0.0007). The scores for dryness at the study end were lower in the SB spray eye compared to control (P = 0.0070). Symptom sums and frequencies of dryness (sum P = 0.0046, frequency P = 0.0016) and watering (sum P = 0.0003, frequency P = 0.013) in the daily logs were lower in the eye treated with SB spray.ConclusionsSB spray on closed eyelids relieved the symptoms of dry eye.</p
    • …
    corecore