110 research outputs found
Cost-effectiveness of the SEN-concept: Specialized Emergency Nurses (SEN) treating ankle/foot injuries
<p>Abstract</p> <p>Background</p> <p>Emergency Departments (EDs) are confronted with progressive overcrowding. As a consequence, the workload for ED physicians increases and waiting times go up with the risk of unnecessary complications and patient dissatisfaction. To cope with these problems, Specialized Emergency Nurses (SENs), regular ED-nurses receiving a short, injury-specific course, were trained to assess and treat minor injuries according to a specific protocol.</p> <p>Methods</p> <p>An economic evaluation was conducted alongside a randomized controlled trial comparing House Officers (HOs) and SENs in their assessment of ankle and foot injuries. Cost prices were established for all parts of healthcare utilization involved. Total costs of health care utilization were computed per patient in both groups. Cost-effectiveness was investigated by comparing the difference in total cost between groups with the difference in sensitivity and specificity between groups in diagnosing fractures and severe sprains. Finally, cost-effectiveness ratios were calculated and presented on a cost-effectiveness plane.</p> <p>Results</p> <p>No significant differences were seen between treatment groups for any of the health care resources assessed. However, the waiting times for both first assessment by a treatment officer and time spent waiting between hearing the diagnosis and final treatment were significantly longer in the HO group. There was no statistically significant difference in costs between groups. The total costs were € 186 (SD € 623) for patients in the SEN group and € 153 (SD € 529) for patients in the HO group. The difference in total costs was € 33 (95% CI: – € 84 to € 155). The incremental cost-effectiveness ratio was € 27 for a reduction of one missed diagnosis and € 18 for a reduction of one false negative.</p> <p>Conclusion</p> <p>Considering the benefits of the SEN-concept in terms of decreased workload for the ED physicians, increased patient satisfaction and decreased waiting times, SENs appear to be a useful solution to the problem of ED crowding.</p
Successful Thrombectomy via a Surgically Reopened Umbilical Vein for Extended Portal Vein Thrombosis Caused by Portal Vein Embolization prior to Extended Liver Resection
Selective portal vein embolization (PVE) before extended liver surgery is an accepted method to stimulate growth of the future liver remnant. Portal vein thrombosis (PVT) of the main stem and the non-targeted branches to the future liver remnant is a rare but major complication of PVE, requiring immediate revascularization. Without revascularization, curative liver surgery is not possible, resulting in a potentially life-threatening situation. We here present a new surgical technique to revascularize the portal vein after PVT by combining a surgical thrombectomy with catheter-based thrombolysis via the surgically reopened umbilical vein. This technique was successfully applied in a patient who developed thrombosis of the portal vein main stem, as well as the left portal vein and its branches to the left lateral segments after selective right-sided PVE in preparation for an extended right hemihepatectomy. The advantage of this technique is the avoidance of an exploration of hepatoduodenal ligament and a venotomy of the portal vein. The minimal surgical trauma facilitates additional intravascular thrombolytic therapy as well as the future right extended hemihepatectomy. We recommend this technique in patients with extensive PVT in which percutaneous less invasive therapies have been proven unsuccessful
Validation of a Length-Adjusted Abdominal Arterial Calcium Score Method for Contrast-Enhanced CT Scans
BACKGROUND: The Agatston score on noncontrast computed tomography (CT) scans is the gold standard for calcium load determination. However, contrast-enhanced CT is commonly used for patients with atherosclerotic cardiovascular diseases (ASCVDs), such as peripheral arterial occlusive disease (PAOD) and abdominal aortic aneurysm (AAA). Currently, there is no validated method to determine calcium load in the aorta and peripheral arteries with a contrast-enhanced CT. This study validated a length-adjusted calcium score (LACS) method for contrast-enhanced CT scans.METHOD: The LACS (calcium volume in mm 3/arterial length in cm) in the abdominal aorta was calculated using four-phase liver CT scans of 30 patients treated between 2017 and 2021 at the University Medical Center Groningen (UMCG) with no aortic disease. Noncontrast CT scans were segmented with a 130 Hounsfield units (HU) threshold, and a patient-specific threshold was used for contrast-enhanced CTs. The LACS was calculated and compared from both segmentations. Secondly, the interobserver variability and the influence of slice thickness (0.75 mm vs. 2.0 mm) was determined. RESULTS: There was a high correlation between the LACS from contrast-enhanced CT scans and the LACS of noncontrast CTs ( R 2 = 0.98). A correction factor of 1.9 was established to convert the LACS derived from contrast-enhanced CT to noncontrast CT scans. LACS interobserver agreement on contrast-enhanced CT was excellent (1.0, 95% confidence interval = 1.0-1.0). The 0.75 mm CT threshold was 541 (459-625) HU compared with 500 (419-568) HU on 2 mm CTs ( p = 0.15). LACS calculated with both thresholds was not significantly different ( p = 0.63). CONCLUSION: The LACS seems to be a robust method for scoring calcium load on contrast-enhanced CT scans in arterial segments with various lengths.</p
p120-catenin prevents multinucleation through control of MKLP1-dependent RhoA activity during cytokinesis.
Spatiotemporal activation of RhoA and actomyosin contraction underpins cellular adhesion and division. Loss of cell-cell adhesion and chromosomal instability are cardinal events that drive tumour progression. Here, we show that p120-catenin (p120) not only controls cell-cell adhesion, but also acts as a critical regulator of cytokinesis. We find that p120 regulates actomyosin contractility through concomitant binding to RhoA and the centralspindlin component MKLP1, independent of cadherin association. In anaphase, p120 is enriched at the cleavage furrow where it binds MKLP1 to spatially control RhoA GTPase cycling. Binding of p120 to MKLP1 during cytokinesis depends on the N-terminal coiled-coil domain of p120 isoform 1A. Importantly, clinical data show that loss of p120 expression is a common event in breast cancer that strongly correlates with multinucleation and adverse patient survival. In summary, our study identifies p120 loss as a driver event of chromosomal instability in cancer
The geometry of Brauer graph algebras and cluster mutations.
In this paper we establish a connection between ribbon graphs and Brauer graphs. As a result, we show that a compact oriented surface with marked points gives rise to a unique Brauer graph algebra up to derived equivalence. In the case of a disc with marked points we show that a dual construction in terms of dual graphs exists. The rotation of a diagonal in an m-angulation gives rise to a Whitehead move in the dual graph, and we explicitly construct a tilting complex on the related Brauer graph algebras reflecting this geometrical move
On positivity of Ehrhart polynomials
Ehrhart discovered that the function that counts the number of lattice points
in dilations of an integral polytope is a polynomial. We call the coefficients
of this polynomial Ehrhart coefficients, and say a polytope is Ehrhart positive
if all Ehrhart coefficients are positive (which is not true for all integral
polytopes). The main purpose of this article is to survey interesting families
of polytopes that are known to be Ehrhart positive and discuss the reasons from
which their Ehrhart positivity follows. We also include examples of polytopes
that have negative Ehrhart coefficients and polytopes that are conjectured to
be Ehrhart positive, as well as pose a few relevant questions.Comment: 40 pages, 7 figures. To appear in in Recent Trends in Algebraic
Combinatorics, a volume of the Association for Women in Mathematics Series,
Springer International Publishin
Cluster mutation-periodic quivers and associated Laurent sequences
We consider quivers/skew-symmetric matrices under the action of mutation (in
the cluster algebra sense). We classify those which are isomorphic to their own
mutation via a cycle permuting all the vertices, and give families of quivers
which have higher periodicity. The periodicity means that sequences given by
recurrence relations arise in a natural way from the associated cluster
algebras. We present a number of interesting new families of non-linear
recurrences, necessarily with the Laurent property, of both the real line and
the plane, containing integrable maps as special cases. In particular, we show
that some of these recurrences can be linearised and, with certain initial
conditions, give integer sequences which contain all solutions of some
particular Pell equations. We extend our construction to include recurrences
with parameters, giving an explanation of some observations made by Gale.
Finally, we point out a connection between quivers which arise in our
classification and those arising in the context of quiver gauge theories.Comment: The final publication is available at www.springerlink.com. 42 pages,
35 figure
Denominators in cluster algebras of affine type
The Fomin-Zelevinsky Laurent phenomenon states that every cluster variable in
a cluster algebra can be expressed as a Laurent polynomial in the variables
lying in an arbitrary initial cluster. We give representation-theoretic
formulas for the denominators of cluster variables in cluster algebras of
affine type. The formulas are in terms of the dimensions of spaces of
homomorphisms in the corresponding cluster category, and hold for any choice of
initial cluster.Comment: 22 pages, no figures. Correction to Defn 1.2. Minor correction
Receptor-Mediated Enhancement of Beta Adrenergic Drug Activity by Ascorbate In Vitro and In Vivo
RATIONALE: Previous in vitro research demonstrated that ascorbate enhances potency and duration of activity of agonists binding to alpha 1 adrenergic and histamine receptors. OBJECTIVES: Extending this work to beta 2 adrenergic systems in vitro and in vivo. METHODS: Ultraviolet spectroscopy was used to study ascorbate binding to adrenergic receptor preparations and peptides. Force transduction studies on acetylcholine-contracted trachealis preparations from pigs and guinea pigs measured the effect of ascorbate on relaxation due to submaximal doses of beta adrenergic agonists. The effect of inhaled albuterol with and without ascorbate was tested on horses with heaves and sheep with carbachol-induced bronchoconstriction. MEASUREMENTS: Binding constants for ascorbate binding to beta adrenergic receptor were derived from concentration-dependent spectral shifts. Dose- dependence curves were obtained for the relaxation of pre-contracted trachealis preparations due to beta agonists in the presence and absence of varied ascorbate. Tachyphylaxis and fade were also measured. Dose response curves were determined for the effect of albuterol plus-and-minus ascorbate on airway resistance in horses and sheep. MAIN RESULTS: Ascorbate binds to the beta 2 adrenergic receptor at physiological concentrations. The receptor recycles dehydroascorbate. Physiological and supra-physiological concentrations of ascorbate enhance submaximal epinephrine and isoproterenol relaxation of trachealis, producing a 3-10-fold increase in sensitivity, preventing tachyphylaxis, and reversing fade. In vivo, ascorbate improves albuterol's effect on heaves and produces a 10-fold enhancement of albuterol activity in "asthmatic" sheep. CONCLUSIONS: Ascorbate enhances beta-adrenergic activity via a novel receptor-mediated mechanism; increases potency and duration of beta adrenergic agonists effective in asthma and COPD; prevents tachyphylaxis; and reverses fade. These novel effects are probably caused by a novel mechanism involving phosphorylation of aminergic receptors and have clinical and drug-development applications
The state of the Martian climate
60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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