Effects of CPAP on oxidative stress and nitrate efficiency in sleep apnoea: a randomised trial.

Background: Previous studies have presented contradictory data concerning obstructive sleep apnoea syndrome (OSAS), lipid oxidation and nitric oxide (NO) bioavailability. This study was undertaken to (1) compare the concentration of 8-isoprostane and total nitrate and nitrite (NOx) in plasma of middle-aged men with OSAS and no other known co-morbidity and healthy controls of the same age, gender and body mass index; and (2) test the hypothesis that nasal continuous positive airway pressure (CPAP) therapy attenuates oxidative stress and nitrate deficiency. Methods: A prospective, randomised, placebo controlled, double-blind, crossover study was performed in 31 consecutive middle-aged men with newly diagnosed OSAS and 15 healthy control subjects. Patients with OSAS were randomised to receive sham CPAP or effective CPAP for 12 weeks. Blood pressure, urinary catecholamine levels and plasma 8-isoprostane and NOx concentrations were obtained before and after both treatment modalities. Results: Patients with OSAS had significantly higher 8-isoprostane levels (median (IQR) 42.5 (29.2-78.2) vs 20.0 (12.5-52.5) pg/ml, p = 0.041, Mann-Whitney test) and lower NOx levels (264 (165-650) vs 590 (251- 1465) mmol/l, p = 0.022) than healthy subjects. Body mass index, blood pressure and urinary catecholamines were unchanged by CPAP therapy, but 8-isoprostane concentrations decreased (38.5 (24.2-58.7) pg/ml at baseline vs 22.5 (16.2-35.3) pg/ml on CPAP, p = 0.0001) and NOx levels increased (280 (177-707) vs 1373 (981-1517) mmol/l, p = 0.0001) after CPAP. Conclusions: OSAS is associated with an increase in oxidative stress and a decrease in NOx that is normalised

Unification of Emission Measurements in Paper and Pulp Mills

Tässä diplomityössä tavoitteena on selvittää käytännöt ja menetelmät, joilla UPM-Kymmenen sellu-, paperi- ja vaneritehtaat ympäri maailman mittaavat ja laskevat ilmapäästönsä. Tämä tehdään kyselylomakkeella, joka lähetetään tehtaiden ympäristöpäälliköille. Kaikki tärkeimmät seikat ilmapäästöihin liittyen, kuten vaaditut jatkuvatoimiset mittaukset, jaksottaiset mittaukset, raportointikäytäntö, kalibrointi jne. kysytään lomakkeessa. Kyselylomakkeessa painotetaan mittauskäytäntöä sellutehtaissa sekä energiantuotannossa. Saatujen tulosten perusteella annetaan ehdotuksia sekä ohjeita tulevaisuutta varten, jotta mittaustulosten kokoaminen helpottuisi ja vertailukelpoisuus paranisi. Työn kirjallisuusosuudessa selvitetään yleisimmät päästölähteet sekä päästökomponentit paperi –ja selluteollisuudessa. Näiden ei toivottujen yhdisteiden syntymekanismit sekä menetelmät niiden poistamiseksi savukaasuista on myös lyhyesti kuvailtu. Myös erilaiset analysointi- ja näytteenottomenetelmät on kerrottu. Erot tehtaiden ympäristöluvissa käydään läpi, jakaen tehtaat kolmeen maantieteelliseen ryhmään. Lupakäytäntöjen osalta Suomen osuutta on painotettu, sillä UPM-Kymmene on varsin Suomikeskeinen yhtiö tehtaiden lukumääriin ja sijainteihin katsottuna. Viranomaismääräykset sekä päästörajat muutamista tehtaista on esitetty havainnollistaakseen alueellisia eroja.

Ilmakehan hiukkasmaisten ioniyhdisteiden online-mittaus

Ilmakehän hiukkaset aiheuttavat merkittäviä ympäristö- ja terveyshaittoja, joihin vaikuttaa hiukkasten kemiallinen koostumus. Hiukkasten kemiallisesta koostumuksesta voidaan hankkia tietoa hiukkasmittauksilla. Työn tavoitteena oli rakentaa jatkuvatoiminen mittausjärjestelmä, jolla voidaan mitata ilmakehän aerosolihiukkasten ionipitoisuuksia. Mittausjärjestelmä koostuu virtuaali-impaktorista, denuderputkista, PILS-laitteesta ja ionikromatografista. Näyteilmavirtaus kulkee ensin esierottimena toimivan virtuaali-impaktorm lävitse, joka poistaa aerodynaamiselta halkaisijaltaan 1,3 um:a suuremmat hiukkaset ilmavirtauksesta. Näyte, joka sisältää 1,3 um:a pienemmät hiukkaset kulkee virtuaali-impaktorin jälkeen kahden 1 % KOH-liuoksella käsitellyn denuderputken lävitse, joilla poistetaan hiukkasmääritystä häiritsevät happamat kaasut näytevirtauksesta. Denuderputkien jälkeen ilmavirtaus saapuu PILS-laitteeseen, jossa hiukkaset kasvatetaan vesihöyryn avulla aerosolipisaroiksi, törmäytetään keräyslevyyn ja sekoitetaan sen jälkeen sisäistä standardiainetta (NaBr) sisältavään kuljetusliuokseen. Kuljetusliuoksen ja aerosolipisaroiden seoksesta koostuva näyteliuos johdetaan PILS-laitteesta ionikromatografille analysoitavaksi. Mittausjärjestelmään liitetyllä ionikromatografilla voidaan analysoida neljä näytetta tunnissa. Näytteistä määritettävät anionit olivat sulfaatti, nitraatti ja kloridi. PILS-mittausjärjestelmää testattiin keräämällä hiukkasnäytteitä samanaikaisesti PILS-laitteella sekä virtuaali-impaktorilla tai suodatinkeräimellä ja vertaamalla saatuja aerosolihiukkasten sulfaattipitoisuuksia keskenään. Testeissa kerättiin joko VOAG-laitteella tuotettuja ammoniumsulfaattihiukkasia tai laboratorion huoneilmaa. PILS-mittausjärjestelmällä mitatut sulfaattipitoisuudet olivat 2-20 % pienempia kuin suodatinkeraimella mitatut, kun kerättiin keinotekoisesti tuotettuja ammoniumsulfaattihiukkasia. Huoneilmaa kerättäessä PILS-mittausjärjestelmällä saadut pitoisuudet olivat noin 10 % pienempiä kuin suodatinkeräystulokset. Koetulokset osoittivat, että mittausjärjestelmällä saadaan analysoiduksi luotettavasti hiukkasten sulfaattipitoisuudet.

Identification of Rare High-Avidity, Tumor-Reactive CD8+ T Cells by Monomeric TCR-Ligand Off-Rates Measurements on Living Cells.

The avidity of the T-cell receptor (TCR) for antigenic peptides presented by the peptide-MHC (pMHC) on cells is a key parameter for cell-mediated immunity. Yet a fundamental feature of most tumor antigen-specific CD8(+) T cells is that this avidity is low. In this study, we addressed the need to identify and select tumor-specific CD8(+) T cells of highest avidity, which are of the greatest interest for adoptive cell therapy in patients with cancer. To identify these rare cells, we developed a peptide-MHC multimer technology, which uses reversible Ni(2+)-nitrilotriacetic acid histidine tags (NTAmers). NTAmers are highly stable but upon imidazole addition, they decay rapidly to pMHC monomers, allowing flow-cytometric-based measurements of monomeric TCR-pMHC dissociation rates of living CD8(+) T cells on a wide avidity spectrum. We documented strong correlations between NTAmer kinetic results and those obtained by surface plasmon resonance. Using NTAmers that were deficient for CD8 binding to pMHC, we found that CD8 itself stabilized the TCR-pMHC complex, prolonging the dissociation half-life several fold. Notably, our NTAmer technology accurately predicted the function of large panels of tumor-specific T cells that were isolated prospectively from patients with cancer. Overall, our results demonstrated that NTAmers are effective tools to isolate rare high-avidity cytotoxic T cells from patients for use in adoptive therapies for cancer treatment.

Force Spectroscopy with Dual-Trap Optical Tweezers: Molecular Stiffness Measurements and Coupled Fluctuations Analysis

ABSTRACT Dual-trap optical tweezers are often used in high-resolution measurements in single-molecule biophysics. Such measurements can be hindered by the presence of extraneous noise sources, the most prominent of which is the coupling of fluctuations along different spatial directions, which may affect any optical tweezers setup. In this article, we analyze, both from the theoretical and the experimental points of view, the most common source for these couplings in dual-trap optical-tweezers setups: the misalignment of traps and tether. We give criteria to distinguish different kinds of misalignment, to estimate their quantitative relevance and to include them in the data analysis. The experimental data is obtained in a, to our knowledge, novel dual-trap optical-tweezers setup that directly measures forces. In the case in which misalignment is negligible, we provide a method to measure the stiffness of traps and tether based on variance analysis. This method can be seen as a calibration technique valid beyond the linear trap region. Our analysis is then employed to measure the persistence length of dsDNA tethers of three different lengths spanning two orders of magnitude. The effective persistence length of such tethers is shown to decrease with the contour length, in accordance with previous studies.

Dynamic single cell measurements of kinase activity by synthetic kinase activity relocation sensors.

BACKGROUND: Mitogen activated protein kinases (MAPK) play an essential role in integrating extra-cellular signals and intra-cellular cues to allow cells to grow, adapt to stresses, or undergo apoptosis. Budding yeast serves as a powerful system to understand the fundamental regulatory mechanisms that allow these pathways to combine multiple signals and deliver an appropriate response. To fully comprehend the variability and dynamics of these signaling cascades, dynamic and quantitative single cell measurements are required. Microscopy is an ideal technique to obtain these data; however, novel assays have to be developed to measure the activity of these cascades. RESULTS: We have generated fluorescent biosensors that allow the real-time measurement of kinase activity at the single cell level. Here, synthetic MAPK substrates were engineered to undergo nuclear-to-cytoplasmic relocation upon phosphorylation of a nuclear localization sequence. Combination of fluorescence microscopy and automated image analysis allows the quantification of the dynamics of kinase activity in hundreds of single cells. A large heterogeneity in the dynamics of MAPK activity between individual cells was measured. The variability in the mating pathway can be accounted for by differences in cell cycle stage, while, in the cell wall integrity pathway, the response to cell wall stress is independent of cell cycle stage. CONCLUSIONS: These synthetic kinase activity relocation sensors allow the quantification of kinase activity in live single cells. The modularity of the architecture of these reporters will allow their application in many other signaling cascades. These measurements will allow to uncover new dynamic behaviour that previously could not be observed in population level measurements.

Editorial: Serial Fecal Calprotectin and Lactoferrin Measurements for Early Diagnosis of Pouchitis After Proctocolectomy for Ulcerative Colitis: Is Pouchoscopy No Longer Needed?

This editorial discusses the role of serial measurements of fecal calprotectin or fecal lactoferrin for the early detection of pouchitis in patients with ulcerative colitis having undergone procto-colectomy with ileo-pouch-anal anastomosis. Furthermore, the role of fecal calprotectin and fecal lactoferrin for the monitoring of pouchitis is highlighted.

Reliability of maximal grip strength measurements and grip strength recovery following a stroke.

STUDY DESIGN: Clinical measurement. PURPOSE: The test-retest reliability of maximal grip strength measurements (MGSM) is examined in subjects for 12 weeks post-stroke together with maximal grip strength recovery and the maximal-grip and upper-extremity strength measurements' relationship with capacity and performance test scores. METHODS: A Jamar dynamometer and the Motricity Index (MI) were used for strength measurements. The Chedoke Arm and Hand Activity Inventory and ABILHAND questionnaire for evaluating capacities and performances. RESULTS: MGSM were reliable (Intraclass Correlation Coefficients = 0.97-0.99, Minimal Detectable Differences = 2.73-4.68 kg). Among the 34 participants, 47% did not have a measurable grip strength one week post-stroke but 50% of these recovered some strength within the first eight weeks. The MGSM and MI scores were correlated with scores of tests of capacity and performance (Spearman's Rank Correlation Coefficients = 0.69-0.94). CONCLUSIONS: MGSM are reliable in the first weeks after a stroke. LEVEL OF EVIDENCE: N/A.

Effect of oral nitrate supplementation on pulmonary hemodynamics during exercise and time trial performance in normoxia and hypoxia: a randomized controlled trial.

BACKGROUND: Hypoxia-induced pulmonary vasoconstriction increases pulmonary arterial pressure (PAP) and may impede right heart function and exercise performance. This study examined the effects of oral nitrate supplementation on right heart function and performance during exercise in normoxia and hypoxia. We tested the hypothesis that nitrate supplementation would attenuate the increase in PAP at rest and during exercise in hypoxia, thereby improving exercise performance. METHODS: Twelve trained male cyclists [age: 31 ± 7 year (mean ± SD)] performed 15 km time-trial cycling (TT) and steady-state submaximal cycling (50, 100, and 150 W) in normoxia and hypoxia (11% inspired O2) following 3-day oral supplementation with either placebo or sodium nitrate (0.1 mmol/kg/day). We measured TT time-to-completion, muscle tissue oxygenation during TT and systolic right ventricle to right atrium pressure gradient (RV-RA gradient: index of PAP) during steady state cycling. RESULTS: During steady state exercise, hypoxia elevated RV-RA gradient (p > 0.05), while oral nitrate supplementation did not alter RV-RA gradient (p > 0.05). During 15 km TT, hypoxia lowered muscle tissue oxygenation (p < 0.05). Nitrate supplementation further decreased muscle tissue oxygenation during 15 km TT in hypoxia (p < 0.05). Hypoxia impaired time-to-completion during TT (p < 0.05), while no improvements were observed with nitrate supplementation in normoxia or hypoxia (p > 0.05). CONCLUSION: Our findings indicate that oral nitrate supplementation does not attenuate acute hypoxic pulmonary vasoconstriction nor improve performance during time trial cycling in normoxia and hypoxia.