Nonaxisymmetric Neutral Modes in Rotating Relativistic Stars

We study nonaxisymmetric perturbations of rotating relativistic stars. modeled as perfect-fluid equilibria. Instability to a mode with angular dependence $\exp(im\phi)$ sets in when the frequency of the mode vanishes. The locations of these zero-frequency modes along sequences of rotating stars are computed in the framework of general relativity. We consider models of uniformly rotating stars with polytropic equations of state, finding that the relativistic models are unstable to nonaxisymmetric modes at significantly smaller values of rotation than in the Newtonian limit. Most strikingly, the m=2 bar mode can become unstable even for soft polytropes of index $N \leq 1.3$, while in Newtonian theory it becomes unstable only for stiff polytropes of index $N \leq 0.808$. If rapidly rotating neutron stars are formed by the accretion-induced collapse of white dwarfs, instability associated with these nonaxisymmetric, gravitational-wave driven modes may set an upper limit on neutron-star rotation. Consideration is restricted to perturbations that correspond to polar perturbations of a spherical star. A study of axial perturbations is in progress.Comment: 57 pages, 9 figure

Hypochloremia and hyponatremia as the initial presentation of cystic fibrosis in three adults

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Most diagnoses of CF are made during infancy or childhood, and are based on respiratory or digestive involvement. Initial extracellular dehydration leading to the diagnosis of CF is usual in infants but has only exceptionally been reported in adults. We describe three new adult cases of CF initially presenting with depletive hyponatremia and hypochloremia following exposure to heat. At first consultation, these patients had no symptoms suggestive of CF. One patient presented with a seizure induced by hyponatremia. The two other patients were siblings carrying a novel c.4434insA mutation in exon 24 of CFTR. Acute dehydration is a very rare initial manifestation of CF but may be life-threatening. The possibility of CF should not be ignored in cases of depletive hyponatremia, hypochloremia or hypokalemic metabolic alkalosis, even in otherwise healthy patients

Circulating microparticles from patients with obstructive sleep apnea enhance vascular contraction: mandatory role of the endothelium

Obstructive sleep apnea (OSA) is characterized by repetitive apnea-hypopnea cycles during sleep associated with oxygen desaturation and sleep disruption. We evaluated the role of circulating microparticles (MPs) from patients with OSA in the regulation of vascular function. MPs from whole blood from patients with OSA or control subjects were injected i.v. into mice. Injection of MPs from patients with OSA induced ex vivo vascular hyperreactivity in aortas with functional endothelium but, in contrast, hyporeactivity in vessels without functional endothelium. Vascular hyperreactivity was blunted in the presence of a nitric oxide synthase inhibitor alone or combined with the cyclooxygenase inhibitor indomethacin. MPs from patients with OSA reduced endothelial nitric oxide synthase activity and nitric oxide production, increased aortic cyclooxygenase-1 and cyclooxygenase-2 expression, and increased thromboxane A(2) and prostacyclin production. Blockade of thromboxane A(2) receptor did not affect the serotonin response in arteries from OSA MP-treated mice. A superoxide dismutase mimetic reduced the vascular hyperreactivity induced by MPs from patients with OSA but had no effect on contraction in vessels from control and non-OSA MP-treated mice. These data provide evidence that circulating MPs from patients with OSA induce ex vivo vascular hyperreactivity with the obligatory role of the endothelium and subtle interactions between the nitric oxide and cyclooxygenase pathways and metabolites. These results highlight the participation of MPs in vascular dysfunction associated with OSA

On micro-structural effects in dielectric mixtures

The paper presents numerical simulations performed on dielectric properties of two-dimensional binary composites on eleven regular space filling tessellations. First, significant contributions of different parameters, which play an important role in the electrical properties of the composite, are introduced both for designing and analyzing material mixtures. Later, influence of structural differences and intrinsic electrical properties of constituents on the composite's over all electrical properties are investigated. The structural differences are resolved by the spectral density representation approach. The numerical technique, without any {\em a-priori} assumptions, for extracting the spectral density function is also presented.Comment: 24 pages, 8 figure and 7 tables. It is submitted to IEEE Transactions on Dielectrics and Electrical Insulatio

Relativistic mechanics of neutron superfluid in (magneto) elastic star crust

At densities below the neutron drip threshold, a purely elastic solid model (including, if necessary, a frozen-in magnetic field) can provide an adequate description of a neutron star crust, but at higher densities it will be necessary to allow for the penetration of the solid lattice by an independently moving current of superfluid neutrons. In order to do this, the previously available category of relativistic elasticity models is combined here with a separately developed category of relativistic superfluidity models in a unified treatment based on the use of an appropriate Lagrangian master function. As well as models of the purely variational kind, in which the vortices flow freely with the fluid, such a master function also provides a corresponding category of non-dissipative models in which the vortices are pinned to the solid structure

Switch of noninvasive ventilation (NIV) to continuous positive airway pressure (CPAP) in patients with obesity hypoventilation syndrome: a pilot study

International audienceObesity is a major worldwide public health issue. The main respiratory complication stemming from obesity is obesity hypoventilation syndrome (OHS). Most of the OHS patients diagnosed during an exacerbation are treated with non invasive ventilation (NIV). Up to date, no prospective study has demonstrated in real life conditions the feasibility of a systematic protocoled switch of NIV to continuous positive airway pressure (CPAP), once stability is achieved

Carcinoma of an unknown primary: are EGF receptor, Her-2/neu, and c-Kit tyrosine kinases potential targets for therapy?

Carcinomas of an unknown primary site (CUP) are heterogeneous tumours with a median survival of only 8 months. Tyrosine kinase inhibitors are promising new drugs. The aim of this study was to determine the expression of EGF-receptor, Her-2/neu, and c-Kit tyrosine kinases in CUP. Paraffin-embedded specimens were obtained from 54 patients with a CUP who were included in the GEFCAPI 01 randomised phase II trial. Immunohistochemistry was performed using the Dako autostainer with antibodies directed against HER-2/neu protein, EGFR protein, and c-Kit protein (CD117). EGFR expression was found in 36 out of 54 samples (66%). In contrast, Her-2/neu overexpression and c-Kit positivity were only detected in 4 and 10% of patients, respectively. No significant association was found between the expression of the tyrosine kinase receptors and prognosis. EGFR expression was significantly associated with response to cisplatin-based chemotherapy: the response rates were 50 and 22% in patients with EGFR-positive tumours and EGFR-negative tumours, respectively (P<0.05). This study shows that EGFR is frequently expressed in CUP. This finding may prompt clinical trials investigating EGFR inhibitors in this setting. In contrast, c-Kit expression and Her-2/neu overexpression occur infrequently in CUP. EGFR expression was correlated to tumour chemosensitivity

Safety and tolerability of long-term treatment with darolutamide in patients with metastatic castration-resistant prostate cancer

Background In patients with metastatic castration-resistant prostate cancer, darolutamide was well tolerated for 25 months, but minimal long-term safety data are available. Methods Treatment-emergent adverse events (TEAEs) for patients receiving darolutamide for a median of 38 months (n = 13) are described in this pooled analysis of individual patient data from phase 1/2 studies. Results All patients reported TEAEs (mostly grade 1/2). The most common TEAEs were diarrhea, abdominal pain, and nausea. Serious TEAEs were reported in six patients (none related to darolutamide). All treatment-related TEAEs (n = 5) were grade 1. Conclusions Long-term darolutamide treatment was well tolerated; no new safety signals observed

‘A phase II study of oral uracil/ftorafur (UFT®) plus leucovorin combined with oxaliplatin (TEGAFOX) as first-line treatment in patients with metastatic colorectal cancer'

This phase II trial was performed to evaluate the efficacy and tolerability of a new combination of Uracil/Ftorafur (UFT®)/leucovorin (LV) and oxaliplatin in patients (pts) with metastatic colorectal cancer (MCRC) who had not received prior chemotherapy for metastatic disease. Between February 2002 and October 2002, 64 patients received UFT® 300 mg m−2 day−1 and LV 90 mg day−1 from day 1 to day 14 combined with oxaliplatin 130 mg m−2 on day 1, every 3 weeks. All patients were evaluable for safety analysis and 58 of 64 patients were eligible for efficacy. Responses were reviewed by an independent review committee. Of the 58 per-protocol defined assessable patients, 1 complete response and 20 partial responses were observed yielding a response rate of 34% (95% CI: 22–47). The median response duration was 8.74 months (range 1.6–14). The median time to progression and the median survival were 5.88 months (95% CI: 4.34–8.21) and 18.2 months (95% CI: 10–20.7), respectively. Diarrhoea and peripheral neuropathy were the most frequent and predictable toxicities. These events were reversible, noncumulative and manageable. Grade 3 diarrhoea occurred in only 11% of the patients. No grade 4 gastrointestinal toxicity was reported in the study. The incidence of grade 3/4 (National Cancer Institute Common Toxicity Criteria 2: NCI-CTC 2) peripheral neuropathy was 15%. Haematological toxicity was of mild to moderate intensity with 10% of the patients with Grade 3/4 neutropenia without any episode of complication. The TEGAFOX regimen, a new combination using UFT®/LV and oxaliplatin every 3 weeks is feasible on an outpatient basis. The combination is safe and active and may offer a promising alternative to the intravenous route. Nevertheless this efficacy results should be confirmed by randomized phase III trials

Rotating Stars in Relativity

Rotating relativistic stars have been studied extensively in recent years, both theoretically and observationally, because of the information one could obtain about the equation of state of matter at extremely high densities and because they are considered to be promising sources of gravitational waves. The latest theoretical understanding of rotating stars in relativity is reviewed in this updated article. The sections on the equilibrium properties and on the nonaxisymmetric instabilities in f-modes and r-modes have been updated and several new sections have been added on analytic solutions for the exterior spacetime, rotating stars in LMXBs, rotating strange stars, and on rotating stars in numerical relativity.Comment: 101 pages, 18 figures. The full online-readable version of this article, including several animations, will be published in Living Reviews in Relativity at http://www.livingreviews.org