469 research outputs found
Kufor-Rakeb syndrome, pallido-pyramidal degeneration with supranuclear upgaze paresis and dementia, maps to 1p36
Kufor-Rakeb syndrome is an autosomal
recessive nigro-striatal-pallidal-pyramidal
neurodegeneration. The onset is in the
teenage years with clinical features of Parkinson’s
disease plus spasticity, supranuclear
upgaze paresis, and dementia. Brain
scans show atrophy of the globus pallidus
and pyramids and, later, widespread cerebral
atrophy. We report linkage in Kufor-
Rakeb syndrome to a 9 cM region of
chromosome 1p36 delineated by the markers
D1S436 and D1S2843, with a maximum
multipoint lod score of 3.6.
(J Med Genet 2001;38:680–682
Recommendations to the Musculoskeletal Health Network, Health Department of Western Australia related to the Spinal Pain Model of Care made on behalf of the Chiropractors Association of Australia (Western Australian Branch)
The 2009 Spinal Model of Care published by the Western Australian Health Department via the Musculoskeletal Health Network would benefit from an update. Best-evidence synthesis and cost-risks-benefits estimations suggest that such guidelines should provide: (1) the early assessment of patients with non-malignant spinal pain (particularly low back) by a musculoskeletal clinician, be it a chiropractor, musculoskeletal physician, osteopath or musculoskeletal physiotherapist with referral within the early stages of the disorder; and (2) the provision of manipulative therapy, where indicated, as a first-line treatment while also providing rehabilitation, health promotion, and contemporary wellness/wellbeing management with the intention of avoiding chronicity. Emerging workforce capacity suggests that early assessment and evidence-based management of non-malignant spinal pain is feasible, leading to better patient outcomes. The authors and the association are hopeful that providing this submission in open access may prove useful for advocates of the chiropractic profession in other jurisdictions
Pre-analytical practices for routine coagulation tests in European laboratories. A collaborative study from the European Organisation for External Quality Assurance Providers in Laboratory Medicine (EQALM)
Background: Correct handling and storage of blood samples for coagulation tests are important to assure correct diagnosis and monitoring. The aim of this study was to assess the pre-analytical practices for routine coagulation testing in European laboratories. Methods: In 2013–2014, European laboratories were invited to fill in a questionnaire addressing pre-analytical requirements regarding tube fill volume, citrate concentration, sample stability, centrifugation and storage conditions for routine coagulation testing (activated partial thromboplastin time [APTT], prothrombin time in seconds [PT-sec] and as international normalised ratio [PT-INR] and fibrinogen). Results: A total of 662 laboratories from 28 different countries responded. The recommended 3.2% (105–109 mmol/L) citrate tubes are used by 74% of the laboratories. Tube fill volumes ≥90% were required by 73%–76% of the laboratories, depending upon the coagulation test and tube size. The variation in centrifugation force and duration was large (median 2500 g [10- and 90-percentiles 1500 and 4000] and 10 min [5 and 15], respectively). Large variations were also seen in the accepted storage time for different tests and sample materials, for example, for citrated blood at room temperature the accepted storage time ranged from 0.5–72 h and 0.5–189 h for PT-INR and fibrinogen, respectively. If the storage time or the tube fill requirements are not fulfilled, 72% and 84% of the respondents, respectively, would reject the samples. Conclusions: There was a large variation in pre-analytical practices for routine coagulation testing in European laboratories, especially for centrifugation conditions and storage time requirements.publishedVersio
Emergence of Anti-Cancer Drug Resistance: Exploring the Importance of the Microenvironmental Niche via a Spatial Model
Practically, all chemotherapeutic agents lead to drug resistance. Clinically,
it is a challenge to determine whether resistance arises prior to, or as a
result of, cancer therapy. Further, a number of different intracellular and
microenvironmental factors have been correlated with the emergence of drug
resistance. With the goal of better understanding drug resistance and its
connection with the tumor microenvironment, we have developed a hybrid
discrete-continuous mathematical model. In this model, cancer cells described
through a particle-spring approach respond to dynamically changing oxygen and
DNA damaging drug concentrations described through partial differential
equations. We thoroughly explored the behavior of our self-calibrated model
under the following common conditions: a fixed layout of the vasculature, an
identical initial configuration of cancer cells, the same mechanism of drug
action, and one mechanism of cellular response to the drug. We considered one
set of simulations in which drug resistance existed prior to the start of
treatment, and another set in which drug resistance is acquired in response to
treatment. This allows us to compare how both kinds of resistance influence the
spatial and temporal dynamics of the developing tumor, and its clonal
diversity. We show that both pre-existing and acquired resistance can give rise
to three biologically distinct parameter regimes: successful tumor eradication,
reduced effectiveness of drug during the course of treatment (resistance), and
complete treatment failure
High frequency oscillations during magnetar flares
The recent discovery of high frequency oscillations during giant flares from
the Soft Gamma Repeaters SGR 1806-20 and SGR 1900+14 may be the first direct
detection of vibrations in a neutron star crust. If this interpretation is
correct it offers a novel means of testing the neutron star equation of state,
crustal breaking strain, and magnetic field configuration. We review the
observational data on the magnetar oscillations, including new timing analysis
of the SGR 1806-20 giant flare using data from the Ramaty High Energy Solar
Spectroscopic Imager (RHESSI) and the Rossi X-ray Timing Explorer (RXTE). We
discuss the implications for the study of neutron star structure and crust
thickness, and outline areas for future investigation.Comment: 5 pages, 1 figure, to appear in the proceedings of the conference
"Isolated Neutron Stars: from the Interior to the Surface" (April 2006,
London), eds. D. Page, R. Turolla, & S. Zane, Astrophysics & Space Science in
pres
Anisotropic Superparamagnetism of Monodispersive Cobalt-Platinum Nanocrystals
Based on the high-temperature organometallic route (Sun et al. Science 287,
1989 (2000)), we have synthesized powders containing CoPt_3 single crystals
with mean diameters of 3.3(2) nm and 6.0(2) nm and small log-normal widths
sigma=0.15(1). In the entire temperature range from 5 K to 400 K, the
zero-field cooled susceptibility chi(T) displays significant deviations from
ideal superparamagnetism. Approaching the Curie temperature of 450(10) K, the
deviations arise from the (mean-field) type reduction of the ferromagnetic
moments, while below the blocking temperature T_b, chi(T) is suppressed by the
presence of energy barriers, the distributions of which scale with the particle
volumes obtained from transmission electron microscopy (TEM). This indication
for volume anisotropy is supported by scaling analyses of the shape of the
magnetic absorption chi''(T,omega) which reveal distribution functions for the
barriers being also consistent with the volume distributions observed by TEM.
Above 200 K, the magnetization isotherms M(H,T) display Langevin behavior
providing 2.5(1) mu_B per CoPt_3 in agreement with reports on bulk and thin
film CoPt_3. The non-Langevin shape of the magnetization curves at lower
temperatures is for the first time interpreted as anisotropic
superparamagnetism by taking into account an anisotropy energy of the
nanoparticles E_A(T). Using the magnitude and temperature variation of E_A(T),
the mean energy barriers and 'unphysical' small switching times of the
particles obtained from the analyses of chi''(T,omega) are explained. Below T_b
hysteresis loops appear and are quantitatively described by a blocking model,
which also ignores particle interactions, but takes the size distributions from
TEM and the conventional field dependence of E_A into account.Comment: 12 pages with 10 figures and 1 table. Version accepted for
publication in Phys. Rev. B . Two-column layou
A novel system to map protein interactions reveals evolutionarily conserved immune evasion pathways on transmissible cancers
Around 40% of humans and Tasmanian devils (Sarcophilus harrisii) develop cancer in their lifetime, compared to less than 10% for most species. In addition, devils are affected by two of the three known transmissible cancers in mammals. Immune checkpoint immunotherapy has transformed human medicine, but a lack of species-specific reagents has limited checkpoint immunology in most species. We developed a cut-and-paste reagent development system and used the fluorescent fusion protein system to show that immune checkpoint interactions are conserved across 160,000,000 years of evolution, CD200 is highly expressed on transmissible tumor cells, and coexpression of CD200R1 can block CD200 surface expression. The system’s versatility across species was demonstrated by fusing a fluorescent reporter to a camelid-derived nanobody that binds human programmed death ligand 1. The evolutionarily conserved pathways suggest that naturally occurring cancers in devils and other species can be used to advance our understanding of cancer and immunological tolerance.</p
The composition of the protosolar disk and the formation conditions for comets
Conditions in the protosolar nebula have left their mark in the composition
of cometary volatiles, thought to be some of the most pristine material in the
solar system. Cometary compositions represent the end point of processing that
began in the parent molecular cloud core and continued through the collapse of
that core to form the protosun and the solar nebula, and finally during the
evolution of the solar nebula itself as the cometary bodies were accreting.
Disentangling the effects of the various epochs on the final composition of a
comet is complicated. But comets are not the only source of information about
the solar nebula. Protostellar disks around young stars similar to the protosun
provide a way of investigating the evolution of disks similar to the solar
nebula while they are in the process of evolving to form their own solar
systems. In this way we can learn about the physical and chemical conditions
under which comets formed, and about the types of dynamical processing that
shaped the solar system we see today.
This paper summarizes some recent contributions to our understanding of both
cometary volatiles and the composition, structure and evolution of protostellar
disks.Comment: To appear in Space Science Reviews. The final publication is
available at Springer via http://dx.doi.org/10.1007/s11214-015-0167-
Frequency spectrum of toroidal Alfv\'en mode in a neutron star with Ferraro's form of nonhomogeneous poloidal magnetic field
Using the energy variational method of magneto-solid-mechanical theory of a
perfectly conducting elastic medium threaded by magnetic field, the frequency
spectrum of Lorentz-force-driven global torsional nodeless vibrations of a
neutron star with Ferraro's form of axisymmetric poloidal nonhomogeneous
internal and dipole-like external magnetic field is obtained and compared with
that for this toroidal Alfv\'en mode in a neutron star with homogeneous
internal and dipolar external magnetic field. The relevance of considered
asteroseismic models to quasi-periodic oscillations of the X-ray flux during
the ultra powerful outbursts of SGR 1806-20 and SGR 1900+14 is discussed.Comment: Accepted for publication in Astrophysics & Space Scienc
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