123 research outputs found
Novel nontoxic mitochondrial probe for confocal fluorescence microscopy.
We propose a 2,5-Bis[1-(4-N-methylpyridinium)ethen-2-yl)]-N-methylpyrrole ditriflate (PEPEP) as a novel nontoxic, nonpotentiometric mitochondrial probe for confocal fluorescence microscopy. PEPEP is a representative chromophore of a large family of heterocyclic fluorescent dyes that show fluorescence emission in aqueous media and great DNA affinity. We check its cytotoxicity and intracellular localization in mammalian and yeast cell cultures. We demonstrate that PEPEP is a very efficient dye for fluorescence confocal microscopy and a valuable alternative to the most frequently used mitochondrial stains. © 2006 Society of Photo-Optical Instrumentation Engineers
Water in Star-Forming Regions with the Herschel Space Observatory (WISH): Overview of key program and first results
`Water In Star-forming regions with Herschel' (WISH) is a key program on the
Herschel Space Observatory designed to probe the physical and chemical
structure of young stellar objects using water and related molecules and to
follow the water abundance from collapsing clouds to planet-forming disks.
About 80 sources are targeted covering a wide range of luminosities and
evolutionary stages, from cold pre-stellar cores to warm protostellar envelopes
and outflows to disks around young stars. Both the HIFI and PACS instruments
are used to observe a variety of lines of H2O, H218O and chemically related
species. An overview of the scientific motivation and observational strategy of
the program is given together with the modeling approach and analysis tools
that have been developed. Initial science results are presented. These include
a lack of water in cold gas at abundances that are lower than most predictions,
strong water emission from shocks in protostellar environments, the importance
of UV radiation in heating the gas along outflow walls across the full range of
luminosities, and surprisingly widespread detection of the chemically related
hydrides OH+ and H2O+ in outflows and foreground gas. Quantitative estimates of
the energy budget indicate that H2O is generally not the dominant coolant in
the warm dense gas associated with protostars. Very deep limits on the cold
gaseous water reservoir in the outer regions of protoplanetary disks are
obtained which have profound implications for our understanding of grain growth
and mixing in disks.Comment: 71 pages, 10 figures, PASP, in pres
Herschel-HIFI detections of hydrides towards AFGL 2591 (Envelope emission versus tenuous cloud absorption)
The Heterodyne Instrument for the Far Infrared (HIFI) onboard the Herschel
Space Observatory allows the first observations of light diatomic molecules at
high spectral resolution and in multiple transitions. Here, we report deep
integrations using HIFI in different lines of hydrides towards the high-mass
star forming region AFGL 2591. Detected are CH, CH+, NH, OH+, H2O+, while NH+
and SH+ have not been detected. All molecules except for CH and CH+ are seen in
absorption with low excitation temperatures and at velocities different from
the systemic velocity of the protostellar envelope. Surprisingly, the CH(JF,P =
3/2_2,- - 1/2_1,+) and CH+(J = 1 - 0, J = 2 - 1) lines are detected in emission
at the systemic velocity. We can assign the absorption features to a foreground
cloud and an outflow lobe, while the CH and CH+ emission stems from the
envelope. The observed abundance and excitation of CH and CH+ can be explained
in the scenario of FUV irradiated outflow walls, where a cavity etched out by
the outflow allows protostellar FUV photons to irradiate and heat the envelope
at larger distances driving the chemical reactions that produce these
molecules.Comment: Accepted for publication in Astronomy and Astrophysics (HIFI first
results issue
Detection of interstellar oxidaniumyl: abundant H2O+ towards the star-forming regions DR21, Sgr B2, and NGC6334
We identify a prominent absorption feature at 1115 GHz, detected in first
HIFI spectra towards high-mass star-forming regions, and interpret its
astrophysical origin. The characteristic hyperfine pattern of the H2O+
ground-state rotational transition, and the lack of other known low-energy
transitions in this frequency range, identifies the feature as H2O+ absorption
against the dust continuum background and allows us to derive the velocity
profile of the absorbing gas. By comparing this velocity profile with velocity
profiles of other tracers in the DR21 star-forming region, we constrain the
frequency of the transition and the conditions for its formation. In DR21, the
velocity distribution of H2O+ matches that of the [CII] line at 158\mu\m and of
OH cm-wave absorption, both stemming from the hot and dense clump surfaces
facing the HII-region and dynamically affected by the blister outflow. Diffuse
foreground gas dominates the absorption towards Sgr B2. The integrated
intensity of the absorption line allows us to derive lower limits to the H2O+
column density of 7.2e12 cm^-2 in NGC 6334, 2.3e13 cm^-2 in DR21, and 1.1e15
cm^-2 in Sgr B2.Comment: Accepted for publication in A&
Pentosan Polysulfate Inhibits Attachment and Infection by SARS-CoV-2 In Vitro: Insights into Structural Requirements for Binding
Two years since the outbreak of the novel coronavirus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic, there remain few clinically effective drugs to complement vaccines. One is the anticoagulant, heparin, which in 2004 was found able to inhibit invasion of SARS-CoV (CoV-1) and which has been employed during the current pandemic to prevent thromboembolic complications and moderate potentially damaging inflammation. Heparin has also been shown experimentally to inhibit SARS-CoV-2 attachment and infection in susceptible cells. At high therapeutic doses however, heparin increases the risk of bleeding and prolonged use can cause heparin-induced thrombocytopenia, a serious side effect. One alternative, with structural similarities to heparin, is the plant-derived, semi-synthetic polysaccharide, pentosan polysulfate (PPS). PPS is an established drug for the oral treatment of interstitial cystitis, is well-tolerated, and exhibits weaker anticoagulant effects than heparin. In an established Vero cell model, PPS and its fractions of varying molecular weights inhibited invasion by SARS-CoV-2. Intact PPS and its size-defined fractions were characterized by molecular weight distribution and chemical structure using nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry, then employed to explore the structural basis of interactions with SARS-CoV-2 spike protein receptor-binding domain (S1 RBD) and the inhibition of Vero cell invasion. PPS was as effective as unfractionated heparin, but more effective in inhibiting cell infection than low-molecular-weight heparin (on a weight/volume basis). Isothermal titration calorimetry and viral plaque-forming assays demonstrated size-dependent binding to S1 RBD and inhibition of Vero cell invasion, suggesting the potential application of PPS as a novel inhibitor of SARS-CoV-2 infection
Acromegaly is associated with increased cancer risk: A survey in Italy
It is debated if acromegalic patients have an increased risk to develop malignancies. The aim of the present study was to assess the standardized incidence ratios (SIRs) of different types of cancer in acromegaly on a large series of acromegalic patients managed in the somatostatin analogs era. It was evaluated the incidence of cancer in an Italian nationwide multicenter cohort study of 1512 acromegalic patients, 624 men and 888 women, mean age at diagnosis 45 \uc2\ub1 13 years, followed up for a mean of 10 years (12573 person-years) in respect to the general Italian population. Cancer was diagnosed in 124 patients, 72 women and 52 men. The SIRs for all cancers was significantly increased compared to the general Italian population (expected: 88, SIR 1.41; 95% CI, 1.18-1.68, P < 0.001). In the whole series, we found a significantly increased incidence of colorectal cancer (SIR 1.67; 95% CI, 1.07-2.58, P = 0.022), kidney cancer (SIR 2.87; 95% CI, 1.55-5.34, P < 0.001) and thyroid cancer (SIR 3.99; 95% CI, 2.32-6.87, P < 0.001). The exclusion of 11 cancers occurring before diagnosis of acromegaly (all in women) did not change remarkably the study outcome. In multivariate analysis, the factors significantly associated with an increased risk of malignancy were age and family history of cancer, with a non-significant trend for the estimated duration of acromegaly before diagnosis. In conclusion, we found evidence that acromegaly in Italy is associated with a moderate increase in cancer risk
Water vapor toward starless cores: the Herschel view
SWAS and Odin provided stringent upper limits on the gas phase water
abundance of dark clouds (x(H2O) < 7x10^-9). We investigate the chemistry of
water vapor in starless cores beyond the previous upper limits using the highly
improved angular resolution and sensitivity of Herschel and measure the
abundance of water vapor during evolutionary stages just preceding star
formation. High spectral resolution observations of the fundamental ortho water
(o-H2O) transition (557 GHz) were carried out with Herschel HIFI toward two
starless cores: B68, a Bok globule, and L1544, a prestellar core embedded in
the Taurus molecular cloud complex. The rms in the brightness temperature
measured for the B68 and L1544 spectra is 2.0 and 2.2 mK, respectively, in a
velocity bin of 0.59 km s^-1. The continuum level is 3.5+/-0.2 mK in B68 and
11.4+/-0.4 mK in L1544. No significant feature is detected in B68 and the 3
sigma upper limit is consistent with a column density of o-H2O N(o-H2O) <
2.5x10^13 cm^-2, or a fractional abundance x(o-H2O) < 1.3x10^-9, more than an
order of magnitude lower than the SWAS upper limit on this source. The L1544
spectrum shows an absorption feature at a 5 sigma level from which we obtain
the first value of the o-H2O column density ever measured in dark clouds:
N(o-H2O) = (8+/-4)x10^12 cm^-2. The corresponding fractional abundance is
x(o-H2O) ~ 5x10^-9 at radii > 7000 AU and ~2x10^-10 toward the center. The
radiative transfer analysis shows that this is consistent with a x(o-H2O)
profile peaking at ~10^-8, 0.1 pc away from the core center, where both
freeze-out and photodissociation are negligible. Herschel has provided the
first measurement of water vapor in dark regions. Prestellar cores such as
L1544 (with their high central densities, strong continuum, and large
envelopes) are very promising tools to finally shed light on the solid/vapor
balance of water in molecular clouds.Comment: Accepted for publication in Astronomy and Astrophysics (HIFI first
results issue
Correction to: Two years later: Is the SARS-CoV-2 pandemic still having an impact on emergency surgery? An international cross-sectional survey among WSES members
Background: The SARS-CoV-2 pandemic is still ongoing and a major challenge for health care services worldwide. In the first WSES COVID-19 emergency surgery survey, a strong negative impact on emergency surgery (ES) had been described already early in the pandemic situation. However, the knowledge is limited about current effects of the pandemic on patient flow through emergency rooms, daily routine and decision making in ES as well as their changes over time during the last two pandemic years. This second WSES COVID-19 emergency surgery survey investigates the impact of the SARS-CoV-2 pandemic on ES during the course of the pandemic.
Methods: A web survey had been distributed to medical specialists in ES during a four-week period from January 2022, investigating the impact of the pandemic on patients and septic diseases both requiring ES, structural problems due to the pandemic and time-to-intervention in ES routine.
Results: 367 collaborators from 59 countries responded to the survey. The majority indicated that the pandemic still significantly impacts on treatment and outcome of surgical emergency patients (83.1% and 78.5%, respectively). As reasons, the collaborators reported decreased case load in ES (44.7%), but patients presenting with more prolonged and severe diseases, especially concerning perforated appendicitis (62.1%) and diverticulitis (57.5%). Otherwise, approximately 50% of the participants still observe a delay in time-to-intervention in ES compared with the situation before the pandemic. Relevant causes leading to enlarged time-to-intervention in ES during the pandemic are persistent problems with in-hospital logistics, lacks in medical staff as well as operating room and intensive care capacities during the pandemic. This leads not only to the need for triage or transferring of ES patients to other hospitals, reported by 64.0% and 48.8% of the collaborators, respectively, but also to paradigm shifts in treatment modalities to non-operative approaches reported by 67.3% of the participants, especially in uncomplicated appendicitis, cholecystitis and multiple-recurrent diverticulitis.
Conclusions: The SARS-CoV-2 pandemic still significantly impacts on care and outcome of patients in ES. Well-known problems with in-hospital logistics are not sufficiently resolved by now; however, medical staff shortages and reduced capacities have been dramatically aggravated over last two pandemic years
It is time to define an organizational model for the prevention and management of infections along the surgical pathway : a worldwide cross-sectional survey
Background The objectives of the study were to investigate the organizational characteristics of acute care facilities worldwide in preventing and managing infections in surgery; assess participants' perception regarding infection prevention and control (IPC) measures, antibiotic prescribing practices, and source control; describe awareness about the global burden of antimicrobial resistance (AMR) and IPC measures; and determine the role of the Coronavirus Disease 2019 pandemic on said awareness. Methods A cross-sectional web-based survey was conducted contacting 1432 health care workers (HCWs) belonging to a mailing list provided by the Global Alliance for Infections in Surgery. The self-administered questionnaire was developed by a multidisciplinary team. The survey was open from May 22, 2021, and June 22, 2021. Three reminders were sent, after 7, 14, and 21 days. Results Three hundred four respondents from 72 countries returned a questionnaire, with an overall response rate of 21.2%. Respectively, 90.4% and 68.8% of participants stated their hospital had a multidisciplinary IPC team or a multidisciplinary antimicrobial stewardship team. Local protocols for antimicrobial therapy of surgical infections and protocols for surgical antibiotic prophylaxis were present in 76.6% and 90.8% of hospitals, respectively. In 23.4% and 24.0% of hospitals no surveillance systems for surgical site infections and no monitoring systems of used antimicrobials were implemented. Patient and family involvement in IPC management was considered to be slightly or not important in their hospital by the majority of respondents (65.1%). Awareness of the global burden of AMR among HCWs was considered very important or important by 54.6% of participants. The COVID-19 pandemic was considered by 80.3% of respondents as a very important or important factor in raising HCWs awareness of the IPC programs in their hospital. Based on the survey results, the authors developed 15 statements for several questions regarding the prevention and management of infections in surgery. The statements may be the starting point for designing future evidence-based recommendations. Conclusion Adequacy of prevention and management of infections in acute care facilities depends on HCWs behaviours and on the organizational characteristics of acute health care facilities to support best practices and promote behavioural change. Patient involvement in the implementation of IPC is still little considered. A debate on how operationalising a fundamental change to IPC, from being solely the HCWs responsibility to one that involves a collaborative relationship between HCWs and patients, should be opened.Peer reviewe
- …