Sulfur dioxide (SO2) from MIPAS in the upper troposphere and lower stratosphere 2002–2012

Vertically resolved distributions of sulfur dioxide (SO2) with global coverage in the height region from the upper troposphere to ~20 km altitude have been derived from observations by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on Envisat for the period July 2002 to April 2012. Retrieved volume mixing ratio profiles representing single measurements are characterized by typical errors in the range of 70–100 pptv and by a vertical resolution ranging from 3 to 5 km. Comparison with observations by the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) revealed a slightly varying bias with altitude of −20 to 50 pptv for the MIPAS data set in case of volcanically enhanced concentrations. For background concentrations the comparison showed a systematic difference between the two major MIPAS observation periods. After debiasing, the difference could be reduced to biases within −10 to 20 pptv in the altitude range of 10–20 km with respect to ACE-FTS. Further comparisons of the debiased MIPAS data set with in situ measurements from various aircraft campaigns showed no obvious inconsistencies within a range of around ±50 pptv. The SO2 emissions of more than 30 volcanic eruptions could be identified in the upper troposphere and lower stratosphere (UTLS). Emitted SO2 masses and lifetimes within different altitude ranges in the UTLS have been derived for a large part of these eruptions. Masses are in most cases within estimations derived from other instruments. From three of the major eruptions within the MIPAS measurement period – Kasatochi in August 2008, Sarychev in June 2009 and Nabro in June 2011 – derived lifetimes of SO2 for the altitude ranges 10–14, 14–18 and 18–22 km are 13.3 ± 2.1, 23.6 ± 1.2 and 32.3 ± 5.5 days respectively. By omitting periods with obvious volcanic influence we have derived background mixing ratio distributions of SO2. At 10 km altitude these indicate an annual cycle at northern mid- and high latitudes with maximum values in summer and an amplitude of about 30 pptv. At higher altitudes of about 16–18 km, enhanced mixing ratios of SO2 can be found in the regions of the Asian and the North American monsoons in summer – a possible connection to an aerosol layer discovered by Vernier et al. (2011b) in that region

Sulfur dioxide (SO₂) from MIPAS in the upper troposphere and lower stratosphere 2002-2012

Vertically resolved distributions of sulfur dioxide (SO2) with global coverage in the height region from the upper troposphere to ~ 20 km altitude have been derived from observations by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on Envisat for the period July 2002 to April 2012. Retrieved volume mixing ratio profiles representing single measurements are characterized by typical errors in the range of 70-100 pptv and by a vertical resolution ranging from 3-5 km. Comparison with ACE-FTS observations revealed a slightly varying bias with altitude of -20 to 50 pptv for the MIPAS dataset in case of volcanically enhanced concentrations. For background concentrations the comparison showed a systematic difference between the two major MIPAS observation periods. After debiasing, the difference could be reduced to biases within -10 to 20 pptv in the altitude range of 10-20 km with respect to ACE-FTS. Further comparisons of the debiased MIPAS dataset with in-situ measurements from various aircraft campaigns showed no obvious inconsistencies within a range of around ±50 pptv. The SO2 emissions of more than thirty volcanic eruptions could be identified in the upper troposphere and lower stratosphere (UTLS). Emitted SO2 masses and lifetimes within different altitude ranges in the UTLS have been derived for a large part of these eruptions. Masses are in most cases within estimations derived from other instruments. From three of the major eruptions within the MIPAS measurement period - Kasatochi in August 2008, Sarychev in June 2009 and Nabro in June 2011 - derived lifetimes of SO2 for the altitude ranges 10-14, 14-18, and 18-22 km are 13.3±2.1, 23.6±1.2, and 32.3±5.5 d, respectively. By omitting periods with obvious volcanic influence we have derived background mixing ratio distributions of SO2. At 10 km altitude these indicate an annual cycle at northern mid- and high latitudes with maximum values in summer and an amplitude of about 30 pptv. At higher altitudes of about 16-18 km enhanced mixing ratios of SO2 can be found in the region of the Asian and the North-American monsoon in summer - a possible connection to an aerosol layer discovered by Vernier et al. (2011b) in that region

Expression of the embryonic stem cell marker SOX2 in early-stage breast carcinoma

<p>Abstract</p> <p>Background</p> <p>The SRY-related HMG-box family of transcription factors member <it>SOX2 </it>has been mainly studied in embryonic stem cells as well as early foregut and neural development. More recently, SOX2 was shown to participate in reprogramming of adult somatic cells to a pluripotent stem cell state and implicated in tumorigenesis in various organs. In breast cancer, SOX2 expression was reported as a feature of basal-like tumors. In this study, we assessed SOX2 expression in 95 primary tumors of postmenopausal breast cancer patients.</p> <p>Methods</p> <p>Samples from 95 patients diagnosed and treated at the University of Tuebingen Institute of Pathology and Women's Hospital were analyzed by immunohistochemistry for SOX2 expression in the primary tumor samples and in corresponding lymph node metastasis, where present. Furthermore, SOX2 amplification status was assessed by FISH in representative samples. In addition, eighteen fresh frozen samples were analyzed for <it>SOX2</it>, <it>NANOG </it>and <it>OCT4 </it>gene expression by real-time PCR.</p> <p>Results</p> <p>SOX2 expression was detected in 28% of invasive breast carcinoma as well as in 44% of ductal carcinoma in situ (DCIS) lesions. A score of SOX2 expression (score 0 to 3) was defined in order to distinguish SOX2 negative (score 0) from SOX2 positive samples (score 1-3) and among latter the subgroup of SOX2 high expressors (score 3 > 50% positive cells). Overall, the incidence of SOX2 expression (score 1-3) was higher than previously reported in a cohort of lymph node negative patients (28% versus 16.7%). SOX2 expression was detected across different breast cancer subtypes and did not correlate with tumor grading. However, high SOX2 expression (score 3) was associated with larger tumor size (p = 0.047) and positive lymph node status (0.018). Corresponding metastatic lymph nodes showed higher SOX2 expression and were significantly more often SOX2 positive than primary tumors (p = 0.0432).</p> <p>Conclusions</p> <p>In this report, we show that the embryonic stem cell factor SOX2 is expressed in a variety of early stage postmenopausal breast carcinomas and metastatic lymph nodes. Our data suggest that SOX2 plays an early role in breast carcinogenesis and high expression may promote metastatic potential. Further studies are needed to explore whether SOX2 can predict metastatic potential at an early tumor stage.</p

Partial purification and reconstruction of the Na⁺-D-glucose cotransport protein from pig renal proximal tubules

Brush border membranes from renal proximal tubules were solubilized with deoxycholate, and the proteins were incorporated into liposomes formed from cholesterol and phospatidylserine by a freeze-thaw procedure. In the proteoliposomes Na+-D-glucose cotransport was demonstrated by showing that the D-glucose concentration in the liposomes increased far above the equilibrium value if a Na+ gradient was applied. The initial D-glucose uptake rate, stimulated by an inside directed gradient of 89 mM Na+, was 4 pmol/mg of protein-1 s-1. High affinity phlorizin binding could not be measured. After two precipitation steps with the solubilized membrane proteins, a protein fraction was obtained in which significantly high affinity phlorizin binding was detected. After reconstitution, proteoliposomes were formed in which more than 70% of the protein was represented by two polypeptides with molecular weights of 94,000 and 52,000. An initial Na+ gradient-dependent D-glucose uptake rate of 118 pmol/mg of protein-1 s-1 was obtained. In these liposomes, the D-glucose uptake rate could be inhibited by phlorizin (Ki = 0.3 μM), and 55-pmol phlorizin-binding sites per mg of protein (KD = 0.5 μM) were measured. In different liposomal preparations a correlation between Na+ gradient-dependent D-glucose uptake rate and the amount of 52,000 molecular weight polypeptide was observed

Profiles and treatment patterns of patients with pulmonary arterial hypertension on monotherapy at experienced centres

Abstract Aims Guideline recommendations highlight the critical role of combination therapy for the treatment of pulmonary arterial hypertension (PAH). Conversely, registry data demonstrate that a considerable number of PAH patients remain on monotherapy. The reasons for this discrepancy remain elusive. The aim of this study was to assess the patient profiles, treatment patterns, and disease characteristics of patients diagnosed with PAH who were kept on monotherapy at experienced pulmonary hypertension (PH) centres and to capture potential reasons for monotherapy. Methods and results We analysed the patient profiles of 182 patients on monotherapy with PAH‐targeted drugs, managed at experienced PH expert centres (Cologne, Giessen, Heidelberg, and Dresden). Patients were identified based on their latest follow‐up visit and analysed retrospectively from the time of PAH diagnosis to last follow‐up. Patients were dichotomized by age, and patient characteristics, treatment patterns, response to therapy, change in risk status, and drug tolerability were recorded during the course of their disease. Patients' mean age was 69.1 ± 13.1 years at the most recent follow‐up (Key Time Point 1) and 64.5 ± 14.9 years at the time of diagnosis (Key Time Point 2). The mean time on monotherapy was 60.7 ± 53.8 months; 35.7/64.3% of patients were male/female. The majority (66.5%) had idiopathic PAH, followed by PAH associated with connective tissue disease (17.0%) and portopulmonary PH (8.2%). Among patients on monotherapy, there were five main clusters: (i) patients with failed escalation attempts mostly because of intolerability (26.9%); (ii) low risk on monotherapy, favourable response, and no reason for escalation (24.2%); (iii) patients with mild PAH (36.3%); (iv) elderly patients with PAH and multiple co‐morbidities (38.5%); and (v) patients with associated forms of PAH where the level of evidence for combination therapies is considered low (16.5%). There were substantial differences between patients above or below the median age (68 years). The most frequently used monotherapy for PAH was phosphodiesterase type 5 inhibitors (75.3%). Conclusions A considerable number of PAH patients are on monotherapy at large PH expert centres, characterized by specific reasons that justify this kind of treatment. Nevertheless, as comprehensive treatment strategies have shown improved long‐term outcomes even in mildly symptomatic patients, each case of monotherapy should be justified