Prognostic factors in seminomas with special respect to HCG: Results of a prospective multicenter study

Objective: In a prospective multicenter trial, it was our intention to elucidate clinical prognostic factors of seminomas with special reference to the importance of human chorionic gonadotropin (HCG) elevations in histologically pure seminomas. Methods: Together with 96 participating urological departments in Germany, Austria, and Switzerland, we recruited 803 seminoma patients between 1986 and 1991. Out of 726 evaluable cases, 378 had elevated, while 348 had normal HCG values in the cubital vein. Histology was reviewed by two reference pathologists. HCG levels were determined in local laboratories and in a study laboratory. Standard therapy was defined as radiotherapy in stages I (30 Gy) and IIA/B (36 Gy) to the paraaortal and the ispilateral (stage I) and bilateral (stage IIA/B) iliac lymph nodes; higher stages received polychemotherapy and surgery in case of residual tumor masses. Statistics included chi-square tests, linear Cox regression, and log-rank test. Results: The HCG elevation is associated with a larger tumor mass (primary tumor and/or metastases). HCG-positive and HCG-negative seminomas had no different prognostic outcome after standard therapy. The overall relapse rate of 6% and the survival rate of 98% after 36 months (median) indicate an excellent prognosis. The calculation of the relative risk of developing a relapse discovered only stage of the disease and elevation of the lactate dehydrogenase concentration and its prolonged marker decay as independent prognostic factors for seminomas. A more detailed analysis of the prognostic significance of the stage revealed that the high relapse rate in stage IIB seminomas after radiotherapy (24%) is responsible for this result. Conclusions: We conclude that HCG-positive seminomas do not represent a special entity. Provided standard therapy is applied, HCG has no influence on the prognosis. Patients with stage IIB disease should be treated with chemotherapy because of the demonstrated higher relapse rate outside the retroperitoneum. Copyright (C) 1999 S. Karger AG. Basel

A three-dimensional numerical solution for the shape of a rotationally distorted polytrope of index unity

PublishedJournal ArticleWe present a new three-dimensional numerical method for calculating the non-spherical shape and internal structure of a model of a rapidly rotating gaseous body with a polytropic index of unity. The calculation is based on a finite-element method and accounts for the full effects of rotation. After validating the numerical approach against the asymptotic solution of Chandrasekhar that is valid only for a slowly rotating gaseous body, we apply it to models of Jupiter and a rapidly rotating, highly flattened star (α Eridani). In the case of Jupiter, the two-dimensional distributions of density and pressure are determined via a hybrid inverse approach by adjusting an a priori unknown coefficient in the equation of state until the model shape matches the observed shape of Jupiter. After obtaining the two-dimensional distribution of density, we then compute the zonal gravity coefficients and the total mass from the non-spherical model that takes full account of rotation-induced shape change. Our non-spherical model with a polytropic index of unity is able to produce the known mass of Jupiter with about 4% accuracy and the zonal gravitational coefficient J 2 of Jupiter with better than 2% accuracy, a reasonable result considering that there is only one parameter in the model. For α Eridani, we calculate its rotationally distorted shape and internal structure based on the observationally deduced rotation rate and size of the star by using a similar hybrid inverse approach. Our model of the star closely approximates the observed flattening. © 2013. The American Astronomical Society. All rights reserved.

Cell cycle-dependent phosphorylation of Theileria annulata schizont surface proteins

The invasion of Theileria sporozoites into bovine leukocytes is rapidly followed by the destruction of the surrounding host cell membrane, allowing the parasite to establish its niche within the host cell cytoplasm. Theileria infection induces host cell transformation, characterised by increased host cell proliferation and invasiveness, and the activation of anti-apoptotic genes. This process is strictly dependent on the presence of a viable parasite. Several host cell kinases, including PI3-K, JNK, CK2 and Src-family kinases, are constitutively activated in Theileria-infected cells and contribute to the transformed phenotype. Although a number of host cell molecules, including IkB kinase and polo-like kinase 1 (Plk1), are recruited to the schizont surface, very little is known about the schizont molecules involved in host-parasite interactions. In this study we used immunofluorescence to detect phosphorylated threonine (p-Thr), serine (p-Ser) and threonine-proline (p-Thr-Pro) epitopes on the schizont during host cell cycle progression, revealing extensive schizont phosphorylation during host cell interphase. Furthermore, we established a quick protocol to isolate schizonts from infected macrophages following synchronisation in S-phase or mitosis, and used mass spectrometry to detect phosphorylated schizont proteins. In total, 65 phosphorylated Theileria proteins were detected, 15 of which are potentially secreted or expressed on the surface of the schizont and thus may be targets for host cell kinases. In particular, we describe the cell cycle-dependent phosphorylation of two T. annulata surface proteins, TaSP and p104, both of which are highly phosphorylated during host cell S-phase. TaSP and p104 are involved in mediating interactions between the parasite and the host cell cytoskeleton, which is crucial for the persistence of the parasite within the dividing host cell and the maintenance of the transformed state

Structural properties and anisotropic electronic transport in SrIrO3 films

Perovskite SrIrO3 (SIO) films epitaxially deposited with a thickness of about 60 nm on various substrate materials display nearly strain-relieved state. Films grown on orthorhombic (110) DyScO3 (DSO) are found to display untwinned bulk-like orthorhombic structure. However, film deposition on cubic (001) SrTiO3 induces a twinned growth of SIO. Resistance measurements on the SIO films reveal only weak temperature dependence, where the resistance R increases with decreasing temperature T. Hall measurements show dominant electron-like transport throughout the temperature range from 2 K to 300 K. At 2 K, the electron concentration and resistivity for SIO on STO amount to ne = 1.4*10^20 cm-3 and 1 mohmcm. Interestingly, the film resistance of untwinned SIO on DSO along the [1-10] and the [001] direction differs by up to 25% indicating pronounced anisotropic electronic transport. The anisotropy of the resistance increases with decreasing T and displays a distinct maximum around 86 K. The specific T-dependence is similar to that of the structural anisotropy sqrt(a2+b2)/c of bulk SIO. Therefore, anisotropic electronic transport in SIO is very likely induced by the orthorhombic distortion. Consequently, for twinned SIO films on STO anisotropy vanishes nearly completely. The experimental results show that structural changes are very likely responsible for the observed anisotropic electronic transport. The strong sensitivity of the electronic transport in SIO films may be explained in terms of the narrow electron-like bands in SIO caused by spin-orbit-coupling and orthorhombic distortion

HD DVD substrates for surface enhanced Raman spectroscopy analysis : fabrication, theoretical predictions and practical performance

Commercial HD DVDs provide a characteristic structure of encoding pits which were utilized to fabricate cost efficiently large area SERS substrates for chemical analysis. The study targets the simulation of the plasmonic structure of the substrates and presents an easily accessible fabrication process to obtain highly sensitive SERS active substrates. The theoretical simulation predicted the formation of supermodes under optimized illumination conditions, which were verified experimentally. First tests of the developed SERS substrates demonstrated their excellent potential for detecting vitamin A and pro- vitamin A at low concentration levels

Weak Localization Thickness Measurements of Si:P Delta-Layers

We report on our results for the characterization of Si:P delta-layers grown by low temperature molecular beam epitaxy. Our data shows that the effective thickness of a delta-layer can be obtained through a weak localization analysis of electrical transport measurements performed in perpendicular and parallel magnetic fields. An estimate of the diffusivity of phosphorous in silicon is obtained by applying this method to several samples annealed at 850 Celsius for intervals of zero to 15 minutes. With further refinements, this may prove to be the most precise method of measuring delta-layer widths developed to date, including that of Secondary Ion Mass Spectrometry analysis

Scattering Mechanisms in a High Mobility Low Density Carbon-Doped (100) GaAs Two-Dimensional Hole System

We report on a systematic study of the density dependence of mobility in a low-density Carbon-doped (100) GaAs two-dimensional hole system (2DHS). At T= 50 mK, a mobility of 2.6 x 10^6 cm^2/Vs at a density p=6.2 x 10^10 cm^- was measured. This is the highest mobility reported for a 2DHS to date. Using a back-gated sample geometry, the density dependence of mobility was studied from 2.8 x 10^10 cm^-2 to 1 x 10^11 cm^-2. The mobility vs. density cannot be fit to a power law dependence of the form mu ~ p^alpha using a single exponent alpha. Our data indicate a continuous evolution of the power law with alpha ranging from ~ 0.7 at high density and increasing to ~ 1.7 at the lowest densities measured. Calculations specific to our structure indicate a crossover of the dominant scattering mechanism from uniform background impurity scattering at high density to remote ionized impurity scattering at low densities. This is the first observation of a carrier density-induced transition from background impurity dominated to remote dopant dominated transport in a single sample.Comment: 4 pages, 5 figures, prepared with LaTex2