Neutrophilic myeloid-derived suppressor cells in cord blood modulate innate and adaptive immune responses

Neonates show an impaired anti-microbial host defence, but the underlying immune mechanisms are not understood fully. Myeloid-derived suppressor cells (MDSCs) represent an innate immune cell subset characterized by their capacity to suppress T cell immunity. In this study we demonstrate that a distinct MDSC subset with a neutrophilic/granulocytic phenotype (Gr-MDSCs) is highly increased in cord blood compared to peripheral blood of children and adults. Functionally, cord blood isolated Gr-MDSCs suppressed T cell proliferation efficiently as well as T helper type 1 (Th1), Th2 and Th17 cytokine secretion. Beyond T cells, cord blood Gr-MDSCs controlled natural killer (NK) cell cytotoxicity in a cell contact-dependent manner. These studies establish neutrophilic Gr-MDSCs as a novel immunosuppressive cell subset that controls innate (NK) and adaptive (T cell) immune responses in neonates. Increased MDSC activity in cord blood might serve as key fetomaternal immunosuppressive mechanism impairing neonatal host defence. Gr-MDSCs in cord blood might therefore represent a therapeutic target in neonatal infections.

Evidence of resonant surface-wave excitation in the relativistic regime through measurements of proton acceleration from grating targets

The interaction of laser pulses with thin grating targets, having a periodic groove at the irradiated surface, is experimentally investigated. Ultrahigh contrast (~10(12)) pulses allow us to demonstrate an enhanced laser-target coupling for the first time in the relativistic regime of ultrahigh intensity >10(19) W/cm(2). A maximum increase by a factor of 2.5 of the cutoff energy of protons produced by target normal sheath acceleration is observed with respect to plane targets, around the incidence angle expected for the resonant excitation of surface waves. A significant enhancement is also observed for small angles of incidence, out of resonance.

Fast intraoperative testosterone assay confirms the location of an ovarian virilizing tumor in a young girl

The detection of testosterone-producing ovarian tumors in childhood and adolescence by imaging techniques only can be difficult because of the tumors' radiological structure and sometimes diminutive size. We describe an 11.5-year-old girl with a 9-month history of voice deepening, mild hirsutism, minor acne, increased growth velocity, weight gain, and clitoromegaly. Laboratory investigation revealed an extremely elevated serum testosterone level without any additional endocrine abnormalities. Abdominal ultrasound and MRI showed a sparsely noticeable solid mass in the center of the right ovary. At laparotomy, blood was selectively drawn from the right and the left ovarian veins. Rapid testosterone measurement revealed a 70-fold higher testosterone concentration in the right ovarian vein within 45 min. Based on this finding, a right salpingo-oophorectomy was performed. The patient's postoperative testosterone level declined within 24 h. The histopathological diagnosis was Leydig cell tumor. In conclusion, the implementation of a fast intraoperative testosterone assay enabled the localization and curative therapy of a Leydig cell tumor. This technique seems to be a good alternative to preoperative selective venous blood sampling when body imaging does not unveil the tumor's site.

Amplification of ultrashort laser pulses by brillouin backscattering in plasmas

Plasma media, by exciting Raman (electron) or Brillouin (ion) waves, have been used to transfer energy from moderately long, high-energy light pulses to short ones. Using multidimensional kinetic simulations, we define here the optimum window in which a Brillouin scheme can be exploited for amplification and compression of short laser pulses over short distances to very high power. We also show that shaping the plasma allows for increasing the efficiency of the process while minimizing other unwanted plasma processes. Moreover, we show that, contrary to what was traditionally thought (i.e., using Brillouin in gases for nanosecond pulse compression), this scheme is able to amplify pulses of extremely short duration.

Production of large volume, strongly magnetized laser-produced plasmas by use of pulsed external magnetic fields

The production of strongly magnetized laser plasmas, of interest for laboratory astrophysics and inertial confinement fusion studies, is presented. This is achieved by coupling a 16 kV pulse-power system. This is achieved by coupling a 16 kV pulse-power system, which generates a magnetic field by means of a split coil, with the ELFIE laser facility at Ecole Polytechnique. In order to influence the plasma dynamics in a significant manner, the system can generate, repetitively and without debris, high amplitude magnetic fields (40 T) in a manner compatible with a high-energy laser environment. A description of the system and preliminary results demonstrating the possibility to magnetically collimate plasma jets are given.

Charge equilibrium of a laser-generated carbon-ion beam in warm dense matter

Using ion carbon beams generated by high intensity short pulse lasers we perform measurements of single shot mean charge equilibration in cold or isochorically heated solid density aluminum matter. We demonstrate that plasma effects in such matter heated up to 1 eV do not significantly impact the equilibration of carbon ions with energies 0.045-0.5  MeV/nucleon. Furthermore, these measurements allow for a first evaluation of semiempirical formulas or ab initio models that are being used to predict the mean of the equilibrium charge state distribution for light ions passing through warm dense matter.

Generation of laser-driven higher harmonics from grating targets

The first experimental evidence of the higher-order harmonic radiation generated by periodically modulated targets (gratings) irradiated by relativistic, ultrashort (<30 fs), high intensity [Iλ(2)=10(20) (W/cm(2)) μm(2)] laser pulse is presented. The interference effects on the grating surface lead to the emission of high harmonics up to 45th order along the target surface when the laser beam is focused onto a grating target close to normal incidence (5°). By means of numerical simulations we demonstrate the possibility of controlling the composition of the higher harmonic spectrum and we prove the influence of the laser pulse parameters in the interaction area (laser focusing and wavefront curvature) on the emission angle of a certain high harmonic order.

Astrophysics of magnetically collimated jets generated from laser-produced plasmas

The generation of astrophysically relevant jets, from magnetically collimated, laser-produced plasmas, is investigated through three-dimensional, magnetohydrodynamic simulations. We show that for laser intensities I∼10(12)-10(14) W cm(-2), a magnetic field in excess of ∼0.1  MG, can collimate the plasma plume into a prolate cavity bounded by a shock envelope with a standing conical shock at its tip, which recollimates the flow into a supermagnetosonic jet beam. This mechanism is equivalent to astrophysical models of hydrodynamic inertial collimation, where an isotropic wind is focused into a jet by a confining circumstellar toruslike envelope. The results suggest an alternative mechanism for a large-scale magnetic field to produce jets from wide-angle winds.

Effect of sorafenib combined with cytostatic agents on hepatoblastoma cell lines and xenografts

BACKGROUND

Sorafenib has recently been shown to reduce tumour growth in hepatoblastoma (HB) xenografts. The effect of a combined administration with cytostatic agents was now investigated.

METHODS

Cell viability after treatment with sorafenib and different cytostatic agents was evaluated in two HB cell lines (HUH6 and HepT1) using MTT assay. ERK signalling was investigated by western blot, NOXA expression by rt-PCR, and formation of DNA adducts using immunocytology. NMRI mice bearing subcutaneous HUH6-derived tumours were treated with sorafenib alone or in combination with cisplatin. Tumour progression, viability, apoptosis, and vascularisation were monitored by tumour volume, AFP levels, TUNEL assay, and CD31 immunostaining, respectively.

RESULTS

The combination of sorafenib and cisplatin led to a remarkable decrease in cell viability. The cisplatin-induced enhanced ERK1/2 activation, but not NOXA expression and the formation of DNA adducts was partly abrogated by sorafenib. In HB xenografts, both, sorafenib and alternated application of sorafenib and cisplatin significantly reduced tumour growth (P<0.05). Levels of AFP were lower in both treated groups (P=0.08). Relative apoptotic areas were increased (P=0.003). Mean vascular density was the lowest in the sorafenib/CDDP group (P=0.02).

CONCLUSION

The combination of sorafenib with cisplatin might be a promising treatment option for high risk or recurrent HB.

Molecular cytogenetics (FISH, GISH) of Coccinia grandis : a ca. 3 myr-old species of cucurbitaceae with the largest Y/autosome divergence in flowering plants

The independent evolution of heteromorphic sex chromosomes in 19 species from 4 families of flowering plants permits studying X/Y divergence after the initial recombination suppression. Here, we document autosome/Y divergence in the tropical Cucurbitaceae Coccinia grandis, which is ca. 3 myr old. Karyotyping and C-value measurements show that the C. grandis Y chromosome has twice the size of any of the other chromosomes, with a male/female C-value difference of 0.094 pg or 10% of the total genome. FISH staining revealed 5S and 45S rDNA sites on autosomes but not on the Y chromosome, making it unlikely that rDNA contributed to the elongation of the Y chromosome; recent end-to-end fusion also seems unlikely given the lack of interstitial telomeric signals. GISH with different concentrations of female blocking DNA detected a possible pseudo-autosomal region on the Y chromosome, and C-banding suggests that the entire Y chromosome in C. grandis is heterochromatic. During meiosis, there is an end-to-end connection between the X and the Y chromosome, but the X does not otherwise differ from the remaining chromosomes. These findings and a review of plants with heteromorphic sex chromosomes reveal no relationship between species age and degree of sex chromosome dimorphism. Its relatively small genome size (0.943 pg/2C in males), large Y chromosome, and phylogenetic proximity to the fully sequenced Cucumis sativus make C. grandis a promising model to study sex chromosome evolution.

Dynamics of self-generated, large amplitude magnetic fields following high-intensity laser matter interaction

The dynamics of magnetic fields with an amplitude of several tens of megagauss, generated at both sides of a solid target irradiated with a high-intensity (~10(19) W/cm(2)) picosecond laser pulse, has been spatially and temporally resolved using a proton imaging technique. The amplitude of the magnetic fields is sufficiently large to have a constraining effect on the radial expansion of the plasma sheath at the target surfaces. These results, supported by numerical simulations and simple analytical modeling, may have implications for ion acceleration driven by the plasma sheath at the rear side of the target as well as for the laboratory study of self-collimated high-energy plasma jets.

Alteration of basic chromosome number by fusion-fission cycles

A complete chromosomal fusion-fission cycle is described for the first time. In the field bean, Vicia faba, this cycle probably started with a reversible fusion of two telocentrics giving rise to the standard metacentric chromosome I. The next step was a recent fission of this chromosome into two stable telocentrics eventually followed by a new fusion reconstituting the metacentric chromosome.

Primary lung metastases in pediatric malignant non-Wilms renal tumors: data from SIOP 93-01/GPOH and SIOP 2001/GPOH

Malignant non-Wilms renal tumors (NWRT) are a small but relevant subgroup of renal neoplasms in children. In this study we analyzed corresponding data from the trials SIOP 93-01/GPOH and SIOP 2001/GPOH of the Society of Pediatric Oncology and Hematology.Data of 22 patients with NWRT and primary lung metastases were retrospectively reviewed. Analyses included epidemiology, tumor characteristics, chemotherapy, local treatment, and outcome.The following diagnoses were registered: Malignant Rhabdoid tumor of the kidney (MRTK, n=15), Renal-cell carcinoma (RCC, n=3), Clear-cell sarcoma of the kidney (CCSK, n=3), and primitive neuro ectodermal tumor (PNET, n=1). Median age of patients at diagnosis was 14 months. Overall survival was 36.36% (8/22). Of the 15 children with MRTK 3 survived, 3/3 patients with RCC, 1/3 patients with CCSK, and 1/1 patient with PNET survived. Lung metastases disappeared in 6 patients after initial chemotherapy, 6/8 patients undergoing local treatment of lung metastases (surgery, irradiation, or both) achieved complete remission. Only patients with complete clearance of lung lesions, either through neoadjuvant chemotherapy or subsequent local treatment, survived. Mean Follow up was 31 months (1-137).Survival of patients with stage IV NWRT is dismal. Complete removal of lung metastases seems mandatory for survival. An aggressive diagnostic and therapeutic approach seems justified in affected children.