296 research outputs found
Resection of oesophageal and oesophagogastric junction cancer liver metastases — a summary of current evidence
Purpose
Metastatic oesophageal cancer is commonly considered as a palliative situation with a poor prognosis. However, there is increasing evidence that well-selected patients with a limited number of liver metastases (ECLM) may benefit from a multimodal approach including surgery.
Methods
A systematic review of the current literature for randomized trials, retrospective studies, and case series with patients undergoing hepatectomies for oesophageal and oesophagogastric junction cancer liver metastases was conducted up to the 31st of August 2021 using the MEDLINE (PubMed) and Cochrane Library databases.
Results
A total of 661 articles were identified. After removal of duplicates, 483 articles were screened, of which 11 met the inclusion criteria. The available literature suggests that ECLM resection in patients with liver oligometastatic disease may lead to improved survival and even long-term survival in some cases. The response to concomitant chemotherapy and liver resection seems to be of significance. Furthermore, a long disease-free interval in metachronous disease, low number of liver metastases, young age, and good overall performance status have been described as potential predictive markers of outcome for the resection of liver metastases.
Conclusion
Surgery may be offered to carefully selected patients to potentially improve survival rates compared to palliative treatment approaches. Studies with standardized patient selection criteria and treatment protocols are required to further define the role for surgery in ECLM. In this context, particular consideration should be given to neoadjuvant treatment concepts including immunotherapies in stage IVB oesophageal and oesophagogastric junction cancer
BRITE-Constellation reveals evidence for pulsations in the enigmatic binary Carinae
Car is a massive, eccentric binary with a rich observational history.
We obtained the first high-cadence, high-precision light curves with the
BRITE-Constellation nanosatellites over 6 months in 2016 and 6 months in 2017.
The light curve is contaminated by several sources including the Homunculus
nebula and neighboring stars, including the eclipsing binary
CPD592628. However, we found two coherent oscillations in the light
curve. These may represent pulsations that are not yet understood but we
postulate that they are related to tidally excited oscillations of Car's
primary star, and would be similar to those detected in lower-mass eccentric
binaries. In particular, one frequency was previously detected by van Genderen
et al. and Sterken et al. through the time period of 1974 to 1995 through
timing measurements of photometric maxima. Thus, this frequency seems to have
been detected for nearly four decades, indicating that it has been stable in
frequency over this time span. These pulsations could help provide the first
direct constraints on the fundamental parameters of the primary star if
confirmed and refined with future observations.Comment: 8 pages, 4 figures, accepted to MNRA
Risk Factors for Hypoxia and Tachypnea Among Adolescents With Vertically-acquired HIV in Nairobi
Background: Chronic lung diseases are increasingly recognized complications of vertically-acquired HIV among adolescents in sub-Saharan Africa and may manifest with hypoxia or tachypnea. We sought to determine the prevalence of and risk factors for hypoxia and tachypnea among adolescents with vertically-acquired HIV in Nairobi, Kenya. Methods: We performed a cross-sectional analysis of 258 adolescents with vertically-acquired HIV who were initiating care at the Coptic Hope Center for Infectious Diseases. Adolescents with documented pneumonia were excluded. Hypoxia was defined as resting oxygen saturation ≤92%, and tachypnea was based on the 99th percentile of age-appropriate respiratory rates. Logistic regression models adjusted for demographics, and HIV severity estimated odds ratios for risk of hypoxia and tachypnea associated with potential risk factors. Results: Overall, 11% of adolescents had hypoxia and 55% had tachypnea. Advanced HIV [adjusted odds ratio (aOR): 2.41] and low CD4 (aOR: 1.74) were associated with greater hypoxia risk, but confidence intervals (CIs) were wide and included the null (95% CI: 0.93–6.23 and 0.69–4.39, respectively). Low CD4 (aOR: 2.45, 95% CI: 1.39–4.32), current antiretroviral therapy use (aOR: 0.48, 95% CI: 0.27–0.86) and stunted growth (aOR: 3.46, 95% CI: 1.94–6.18) were associated with altered tachypnea risk. Conclusions: Hypoxia and tachypnea are common among adolescents with vertically-acquired HIV. There was a suggestion that advanced HIV and low CD4 were associated with greater hypoxia risk. Low CD4, lack of antiretroviral therapy use and stunted growth are risk factors for tachypnea. Our findings highlight the chronic lung disease burden in this population and may inform diagnostic algorithms
Absence of an association of human polyomavirus and papillomavirus infection with lung cancer in China: a nested case–control study
Abstract Background Studies of human polyomavirus (HPyV) infection and lung cancer are limited and those regarding the association of human papillomavirus (HPV) infection and lung cancer have produced inconsistent results. Methods We conducted a nested case–control study to assess the association between incident lung cancer of various histologies and evidence of prior infection with HPyVs and HPVs. We selected serum from 183 cases and 217 frequency matched controls from the Yunnan Tin Miner’s Cohort study, which was designed to identify biomarkers for early detection of lung cancer. Using multiplex liquid bead microarray (LBMA) antibody assays, we tested for antibodies to the VP1 structural protein and small T antigen (ST-Ag) of Merkel cell, KI, and WU HPyVs. We also tested for antibodies against HPV L1 structural proteins (high-risk types 16, 18, 31, 33, 52, and 58 and low-risk types 6 and 11) and E6 and E7 oncoproteins (high risk types 16 and 18). Measures of antibody reactivity were log transformed and analyzed using logistic regression. Results We found no association between KIV, WUV, and MCV antibody levels and incident lung cancer (P-corrected for multiple comparisons >0.10 for all trend tests). We also found no association with HPV-16, 18, 31, 33, 52, and 58 seropositivity (P-corrected for multiple comparisons >0.05 for all). Conclusions Future studies of infectious etiologies of lung cancer should look beyond HPyVs and HPVs as candidate infectious agents
Quantum-state control in optical lattices
We study the means to prepare and coherently manipulate atomic wave packets
in optical lattices, with particular emphasis on alkali atoms in the
far-detuned limit. We derive a general, basis independent expression for the
lattice operator, and show that its off-diagonal elements can be tailored to
couple the vibrational manifolds of separate magnetic sublevels. Using these
couplings one can evolve the state of a trapped atom in a quantum coherent
fashion, and prepare pure quantum states by resolved-sideband Raman cooling. We
explore the use of atoms bound in optical lattices to study quantum tunneling
and the generation of macroscopic superposition states in a double-well
potential. Far-off-resonance optical potentials lend themselves particularly
well to reservoir engineering via well controlled fluctuations in the
potential, making the atom/lattice system attractive for the study of
decoherence and the connection between classical and quantum physics.Comment: 35 pages including 8 figures. To appear in Phys. Rev. A. March 199
Glutathione as a Biomarker in Parkinson’s Disease: Associations with Aging and Disease Severity
Objectives. Oxidative stress contributes to Parkinson’s disease (PD) pathophysiology and progression. The objective was to describe central and peripheral metabolites of redox metabolism and to describe correlations between glutathione (Glu) status, age, and disease severity. Methods. 58 otherwise healthy individuals with PD were examined during a single study visit. Descriptive statistics and scatterplots were used to evaluate normality and distribution of this cross-sectional sample. Blood tests and magnetic resonance spectroscopy (MRS) were used to collect biologic data. Spearman’s rank-order correlation coefficients were used to evaluate the strength and direction of the association. The Unified PD Rating Scale (UPDRS) and the Patient-Reported Outcomes in PD (PRO-PD) were used to rate disease severity using regression analysis. Results. Blood measures of Glu decreased with age, although there was no age-related decline in MRS Glu. The lower the blood Glu concentration, the more severe the UPDRS (P=0.02, 95% CI: −13.96, −1.14) and the PRO-PD (P=0.01, 95% CI: −0.83, −0.11) scores. Discussion. These data suggest whole blood Glu may have utility as a biomarker in PD. Future studies should evaluate whether it is a modifiable risk factor for PD progression and whether Glu fortification improves PD outcomes
Spectroscopy, MOST Photometry, and Interferometry of MWC 314: Is it an LBV or an interacting binary?
MWC 314 is a bright candidate luminous blue variable that resides in a fairly
close binary system, with an orbital period of 60.7530.003 d. We observed
MWC 314 with a combination of optical spectroscopy, broad-band ground- and
space-based photometry, as well as with long baseline, near-infrared
interferometry. We have revised the single-lined spectroscopic orbit and
explored the photometric variability. The orbital light curve displays two
minima each orbit that can be partially explained in terms of the tidal
distortion of the primary that occurs around the time of periastron. The
emission lines in the system are often double-peaked and stationary in their
kinematics, indicative of a circumbinary disc. We find that the stellar wind or
circumbinary disc is partially resolved in the K\prime-band with the longest
baselines of the CHARA Array. From this analysis, we provide a simple,
qualitative model in an attempt to explain the observations. From the
assumption of Roche Lobe overflow and tidal synchronisation at periastron, we
estimate the component masses to be M1 M and M2
M, which indicates a mass of the LBV that is extremely low. In addition
to the orbital modulation, we discovered two pulsational modes with the MOST
satellite. These modes are easily supported by a low-mass hydrogen-poor star,
but cannot be easily supported by a star with the parameters of an LBV. The
combination of these results provides evidence that the primary star was likely
never a normal LBV, but rather is the product of binary interactions. As such,
this system presents opportunities for studying mass-transfer and binary
evolution with many observational techniques.Comment: 26 pages, 7 figures, 5 tables, 2 appendices with 7 additional tables
and 2 additional figures. Accepted for publication in MNRA
MOST detects corotating bright spots on the mid-O type giant {\xi} Persei
We have used the MOST (Microvariability and Oscillations of STars)
microsatellite to obtain four weeks of contiguous high-precision broadband
visual photometry of the O7.5III(n)((f)) star {\xi} Persei in November 2011.
This star is well known from previous work to show prominent DACs (Discrete
Absorption Components) on time-scales of about 2 d from UV spectroscopy and NRP
(Non Radial Pulsation) with one (l = 3) p-mode oscillation with a period of 3.5
h from optical spectroscopy. Our MOST-orbit (101.4 min) binned photometry fails
to reveal any periodic light variations above the 0.1 mmag 3-sigma noise level
for periods of hours, while several prominent Fourier peaks emerge at the 1
mmag level in the two-day period range. These longer-period variations are
unlikely due to pulsations, including gravity modes. From our simulations based
upon a simple spot model, we deduce that we are seeing the photometric
modulation of several co-rotating bright spots on the stellar surface. In our
model, the starting times (random) and lifetimes (up to several rotations) vary
from one spot to another yet all spots rotate at the same period of 4.18 d, the
best-estimated rotation period of the star. This is the first convincing
reported case of co-rotating bright spots on an O star, with important
implications for drivers of the DACs (resulting from CIRs - Corotating
Interaction Regions) with possible bright-spot generation via a breakout at the
surface of a global magnetic field generated by a subsurface convection zone.Comment: 9 pages, 4 figures, 2 tables, MNRAS in pres
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