50 research outputs found
Cervical spine surgery for tandem spinal stenosis: The impact on low back pain
Objective
Tandem spinal stenosis (TSS) can present similarly to cervical myelopathy, but often has a worse prognosis. Few studies have investigated outcomes and compared treatment approaches for patients with TSS. We sought to determine the impact of cervical spine surgery on cervical and lumbar spine symptoms in patients with symptomatic tandem spinal stenosis.
Patients Methods
84 patients with TSS were identified over 5 years. 48 underwent cervical spine surgery alone, 20 underwent both cervical and lumbar spine surgery, and 16 received conservative treatment alone (conservative cohort). Quality of life (QOL) measures included the Visual Analogue Scale (VAS) for arm, neck, and back pain, and EuroQOL-5 Dimensions (EQ-5D). QOL data were acquired at baseline (pre-operative) and 1 year postoperatively via an institutional prospectively collected database.
Results
Both surgical cohorts showed significant (p < 0.01) pre- to postoperative improvement for VAS neck and arm scores at 1-year post-op and significantly (p < 0.01) greater improvements than the conservative cohort. In addition, the cohort undergoing cervical spine surgery alone experienced significant improvement in the EQ-5D score whereas those undergoing both cervical and lumbar spine surgery did not.
Conclusions
Cervical spine surgery with or without follow-up lumbar spine surgery significantly improves neck pain in patients with TSS. In contrast, cervical spine surgery in these patients does not improve lumbar symptoms. Lumbar surgery also did not improve low back pain or quality of life. Future prospective studies are necessary to examine the impact of lumbar decompression alone on cervical spine symptoms in patients with TSS
Quality of life changes after lumbar decompression in patients with tandem spinal stenosis
Objective
Tandem spinal stenosis (TSS) is a degenerative spinal condition characterized by spinal canal narrowing at 2 or more distinct spinal levels. It is an aging-related condition that is likely to increase as the population ages, but which remains poorly described in the literature. Here we sought to determine the impact of primary lumbar decompression on quality-of-life (QOL) outcomes in patients with symptomatic TSS.
Patients and methods
We retrospectively reviewed 803 patients with clinical and radiographic evidence of TSS treated between 2008 and 2014 with a minimum 2-year follow-up. The records of patients with clinical and radiographic evidence of concurrent cervical and lumbar stenosis were reviewed. Prospectively gathered QOL data, including the Pain Disability Questionnaire (PDQ), Patient Health Questionnaire-9 (PHQ-9), EuroQOL-5 Dimensions (EQ-5D), and Visual Analogue Scale (VAS) for low back pain, were assessed at the 6-month, 1-year, and 2-year follow-ups.
Results
Of 803 identified patients (mean age 66.2 years; 46.9% male), 19.6% underwent lumbar decompression only, 14.1% underwent cervical + lumbar decompression, and 66.4% underwent conservative management only. Baseline VAS scores were similar across all groups, but patients undergoing conservative management had better baseline QOL scores on all other measures. Both surgical cohorts experienced significant improvements in the VAS, PDQ, and EQ-5D at all time points; patients in the cervical + lumbar cohort also had significant improvement in the PHQ-9. Conservatively managed patients showed no significant improvement in QOL scores at any follow-up interval.
Conclusion
Lumbar decompression with or without cervical decompression improves low back pain and QOL outcomes in patients with TSS. The decision to prioritize lumbar decompression is therefore unlikely to adversely affect long-term quality-of-life improvements
Antimicrobial Resistance Markers of Class 1 and Class 2 Integron-bearing Escherichia coli from Irrigation Water and Sediments
Municipal and agricultural pollution affects the Rio Grande, a river that separates the United States from Mexico. Three hundred and twenty-two Escherichia coli isolates were examined for multiple antibiotic resistance phenotypes and the prevalence of class 1 and class 2 integron sequences. Thirty-two (10%) of the isolates were resistant to multiple antibiotics. Four (13%) of these isolates contained class 1–specific integron sequences; one isolate contained class 2 integron–specific sequences. Sequencing showed that the class 1 integron–bearing strain contained two distinct gene cassettes, sat-1 and aadA. Although three of the four class 1 integron–bearing strains harbored the aadA sequence, none of the strains was phenotypically resistant to streptomycin. These results suggest that integron-bearing E. coli strains can be present in contaminated irrigation canals and that these isolates may not express these resistance markers
OGLE-2018-BLG-0532Lb: Cold Neptune With Possible Jovian Sibling
We report the discovery of the planet OGLE-2018-BLG-0532Lb, with very obvious
signatures in the light curve that lead to an estimate of the planet-host mass
ratio . Although there are
no obvious systematic residuals to this double-lens/single-source (2L1S) fit,
we find that can be significantly improved by adding either a third
lens (3L1S, ) or second source (2L2S, ) to
the lens-source geometry. After thorough investigation, we conclude that we
cannot decisively distinguish between these two scenarios and therefore focus
on the robustly-detected planet. However, given the possible presence of a
second planet, we investigate to what degree and with what probability such
additional planets may affect seemingly single-planet light curves. Our best
estimates for the properties of the lens star and the secure planet are: a host
mass , system distance kpc and planet mass
with projected separation au.
However, there is a relatively bright (and also relatively blue) star
projected within mas of the lens, and if future high-resolution images
show that this is coincident with the lens, then it is possible that it is the
lens, in which case, the lens would be both more massive and more distant than
the best-estimated values above.Comment: 48 pages, 9 figures, 7 table
A rotating white dwarf shows different compositions on its opposite faces
White dwarfs, the extremely dense remnants left behind by most stars after
their death, are characterised by a mass comparable to that of the Sun
compressed into the size of an Earth-like planet. In the resulting strong
gravity, heavy elements sink toward the centre and the upper layer of the
atmosphere contains only the lightest element present, usually hydrogen or
helium. Several mechanisms compete with gravitational settling to change a
white dwarf's surface composition as it cools, and the fraction of white dwarfs
with helium atmospheres is known to increase by a factor ~2.5 below a
temperature of about 30,000 K; therefore, some white dwarfs that appear to have
hydrogen-dominated atmospheres above 30,000 K are bound to transition to be
helium-dominated as they cool below it. Here we report observations of ZTF
J203349.8+322901.1, a transitioning white dwarf with two faces: one side of its
atmosphere is dominated by hydrogen and the other one by helium. This peculiar
nature is likely caused by the presence of a small magnetic field, which
creates an inhomogeneity in temperature, pressure or mixing strength over the
surface. ZTF J203349.8+322901.1 might be the most extreme member of a class of
magnetic, transitioning white dwarfs -- together with GD 323, a white dwarf
that shows similar but much more subtle variations. This new class could help
shed light on the physical mechanisms behind white dwarf spectral evolution.Comment: 45 pages, 11 figure
Optical follow-up of the neutron star-black hole mergers S200105ae and S200115j
LIGO and Virgo’s third observing run revealed the first neutron star–black hole (NSBH) merger candidates in gravitational waves. These events are predicted to synthesize r-process elements1,2 creating optical/near-infrared ‘kilonova’ emission. The joint gravitational wave and electromagnetic detection of an NSBH merger could be used to constrain the equation of state of dense nuclear matter3, and independently measure the local expansion rate of the Universe4. Here, we present the optical follow-up and analysis of two of the only three high-significance NSBH merger candidates detected to date, S200105ae and S200115j, with the Zwicky Transient Facility5. The Zwicky Transient Facility observed ~48% of S200105ae and ~22% of S200115j’s localization probabilities, with observations sensitive to kilonovae brighter than −17.5 mag fading at 0.5 mag d−1 in the g- and r-bands; extensive searches and systematic follow-up of candidates did not yield a viable counterpart. We present state-of-the-art kilonova models tailored to NSBH systems that place constraints on the ejecta properties of these NSBH mergers. We show that with observed depths of apparent magnitude ~22 mag, attainable in metre-class, wide-field-of-view survey instruments, strong constraints on ejecta mass are possible, with the potential to rule out low mass ratios, high black hole spins and large neutron star radii
Rhetoric and Relationship in Milton\u27s Paradise Lost
Archival abstract submitte