The activation of immune cells by targeting checkpoint inhibitors showed promising results with increased patient survival in distinct primary cancers. Since only limited data exist for human brain metastases, we aimed at characterizing... more
The activation of immune cells by targeting checkpoint inhibitors showed promising results with increased patient survival in distinct primary cancers. Since only limited data exist for human brain metastases, we aimed at characterizing tumor infiltrating lymphocytes (TILs) and expression of immune checkpoints in the respective tumors. Two brain metastases cohorts, a mixed entity cohort (n = 252) and a breast carcinoma validation cohort (n = 96) were analyzed for CD3+, CD8+, FOXP3+, PD-1+ lymphocytes and PD-L1+ tumor cells by immunohistochemistry. Analyses for association with clinico-epidemiological and neuroradiological parameters such as patient survival or tumor size were performed. TILs infiltrated brain metastases in three different patterns (stromal, peritumoral, diffuse). While carcinomas often show a strong stromal infiltration, TILs in melanomas often diffusely infiltrate the tumors. Highest levels of CD3+ and CD8+ lymphocytes were seen in renal cell carcinomas (RCC) and s...
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Angiogenesis and inflammation are two highly linked processes. In the last decade, several factors with dual function in both of these major pathways have been identified. This review focuses on angiopoietin-2 (Ang-2), an important... more
Angiogenesis and inflammation are two highly linked processes. In the last decade, several factors with dual function in both of these major pathways have been identified. This review focuses on angiopoietin-2 (Ang-2), an important proangiogenic factor that has more recently been implicated in mediating inflammatory processes as well. Ang-2 is upregulated in multiple inflammatory diseases and has been implicated in the direct control of inflammation-related signaling pathways. As a consequence of its multiple roles, designs for therapeutic targeting of Ang-2 should consider the dual function of this factor in regulating angiogenesis and inflammation.
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Today, the generation of magnetic fields in solar-type stars and its relation to activity and rotation can coherently be explained, although it is certainly not understood in its entirety. Rotation facilitates the generation of magnetic... more
Today, the generation of magnetic fields in solar-type stars and its relation to activity and rotation can coherently be explained, although it is certainly not understood in its entirety. Rotation facilitates the generation of magnetic flux that couples to the stellar wind, slowing down the star. There are still many open questions, particularly at early phases (young age), and at
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Characterizing multiplicity in the very low mass (VLM) domain is a topic of much current interest and fundamental importance. Here we report on a near-infrared adaptive optics imaging survey of 28 young brown dwarfs and VLM stars, 26 of... more
Characterizing multiplicity in the very low mass (VLM) domain is a topic of much current interest and fundamental importance. Here we report on a near-infrared adaptive optics imaging survey of 28 young brown dwarfs and VLM stars, 26 of which are in the Chamaeleon I star-forming region, using the ESO Very Large Telescope. Our findings in Cha I -- the
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We report the findings of a comprehensive study of disk accretion and related phenomena in four of the nearest young stellar associations spanning 6-30 million years in age, an epoch that may coincide with the late stages of planet... more
We report the findings of a comprehensive study of disk accretion and related phenomena in four of the nearest young stellar associations spanning 6-30 million years in age, an epoch that may coincide with the late stages of planet formation. We have obtained ~650 multiepoch high-resolution optical spectra of 100 low-mass stars that are likely members of the eta Chamaeleontis
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SONYC is a comprehensive project to establish the census of brown dwarfs and planetary-mass objects in nearby star forming regions. Our goal is to identify all young substellar objects down to a few Jupiter masses (~ 0.005 M_&sun;), i.e.,... more
SONYC is a comprehensive project to establish the census of brown dwarfs and planetary-mass objects in nearby star forming regions. Our goal is to identify all young substellar objects down to a few Jupiter masses (~ 0.005 M_&sun;), i.e., the opacity limit for fragmentation. In our first survey region NGC1333 we see evidence for environmental effects in this mass regime
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Various structure-function relationships regarding drought-induced cavitation resistance of secondary xylem have been postulated. These hypotheses were tested on wood of 10 Prunus species showing a range in P50 (i.e., the pressure... more
Various structure-function relationships regarding drought-induced cavitation resistance of secondary xylem have been postulated. These hypotheses were tested on wood of 10 Prunus species showing a range in P50 (i.e., the pressure corresponding to 50% loss of hydraulic conductivity) from -3.54 to -6.27 MPa. Hydraulically relevant wood characters were quantified using light and electron microscopy. A phylogenetic tree was constructed to investigate evolutionary correlations using a phylogenetically independent contrast (PIC) analysis. Vessel-grouping characters were found to be most informative in explaining interspecific variation in P50, with cavitation-resistant species showing more solitary vessels than less resistant species. Co-evolution between vessel-grouping indices and P50 was reported. P50 was weakly correlated with the shape of the intervessel pit aperture, but not with the total intervessel pit membrane area per vessel. A negative correlation was found between P50 and intervessel pit membrane thickness, but this relationship was not supported by the PIC analysis. Cavitation resistance has co-evolved with vessel grouping within Prunus and was mainly influenced by the spatial distribution of the vessel network.
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Isolated planetary-mass objects (IPMOs) have masses close to or below the deuterium-burning mass limit (~ 15 M Jup)at the bottom of the stellar initial mass function. We present an exploratory survey for disks in this mass regime, based... more
Isolated planetary-mass objects (IPMOs) have masses close to or below the deuterium-burning mass limit (~ 15 M Jup)at the bottom of the stellar initial mass function. We present an exploratory survey for disks in this mass regime, based on a dedicated observing ...
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VINCENT GEERS1,2, ALEXANDER SCHOLz3, RAY JAYAWARDHANA1,6, EVE LEE1, DAVID LAFRENI`ERE1,4, AND MOTOHIDE TAMURA5 1 Department of Astronomy & Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada; ...
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Diffraction and reflection of a slow metastable neon beam by an evanescent light grating. M CHRIST, A SCHOLZ, M SCHIFFER, R DEUTSCHMANN, W ERTMER Optics communications 107:3-43-4, 211-217, Elsevier Science, 1994. ...
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Diabetes mellitus is a major risk factor for the development of cardiovascular disease and oxidative stress plays an important role in this process. Therefore, we investigated the effects of hyperglycemia on the formation of reactive... more
Diabetes mellitus is a major risk factor for the development of cardiovascular disease and oxidative stress plays an important role in this process. Therefore, we investigated the effects of hyperglycemia on the formation of reactive oxygen species (ROS) and nitric oxide/cGMP signaling in two different endothelial cell cultures. Human umbilical vein endothelial cells (HUVEC) and EA.hy 926 cells showed increased oxidative stress and impaired NO-cGMP signaling in response to hyperglycemia. The major difference between the two different cell types was the dramatic decrease in viability in HUVEC whereas EA.hy cells showed rather increased growth under hyperglycemic conditions. Starvation led to an additional substantial decrease in viability and increased superoxide formation in HUVEC. Both endothelial cell types, HUVEC and EA.hy 926, may be used as models for vascular hyperglycemia. However, high growth medium should be used to avoid starvation-induced oxidative stress and cell death.
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Prophylactic measures are reducing costs of healthcare without lowering its quality. Telemetric Personal Health Monitoring (TPHM) Systems with multi-parametric sensors allow an active integration of a patient into his treatment. A common... more
Prophylactic measures are reducing costs of healthcare without lowering its quality. Telemetric Personal Health Monitoring (TPHM) Systems with multi-parametric sensors allow an active integration of a patient into his treatment. A common problem in such a system is ...
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Research Interests: Cancer, Macrophages, Gene expression, Humans, Mice, and 3 moreAnimals, Monocytes, and Matrix Metalloproteinase
MicroRNAs are endogenously expressed small noncoding RNAs that regulate gene expression on the posttranscriptional level. The miR-17-92 cluster (encoding miR-17, -18a, -19a/b, -20a, and miR-92a) is highly expressed in tumor cells and is... more
MicroRNAs are endogenously expressed small noncoding RNAs that regulate gene expression on the posttranscriptional level. The miR-17-92 cluster (encoding miR-17, -18a, -19a/b, -20a, and miR-92a) is highly expressed in tumor cells and is up-regulated by ischemia. Whereas miR-92a was recently identified as negative regulator of angiogenesis, the specific functions of the other members of the cluster are less clear. Here we demonstrate that overexpression of miR-17, -18a, -19a, and -20a significantly inhibited 3-dimensional spheroid sprouting in vitro, whereas inhibition of miR-17, -18a, and -20a augmented endothelial cell sprout formation. Inhibition of miR-17 and miR-20a in vivo using antagomirs significantly increased the number of perfused vessels in Matrigel plugs, whereas antagomirs that specifically target miR-18a and miR-19a were less effective. However, systemic inhibition of miR-17/20 did not affect tumor angiogenesis. Further mechanistic studies showed that miR-17/20 targets several proangiogenic genes. Specifically, Janus kinase 1 was shown to be a direct target of miR-17. In summary, we show that miR-17/20 exhibit a cell-intrinsic antiangiogenic activity in endothelial cells. Inhibition of miR-17/20 specifically augmented neovascularization of Matrigel plugs but did not affect tumor angiogenesis indicating a context-dependent regulation of angiogenesis by miR-17/20 in vivo.
Research Interests: MicroRNA, Humans, Endothelial Cells, Mice, Animals, and 5 moreBlood, Clinical Sciences, microRNAs, Endothelial cell, and Neoplasms
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A large fraction of stars are members of binary systems. Yet, the formation and early evolution of binary and multiple stars is not well understood theoretically and poorly constrained observationally. We present findings from a... more
A large fraction of stars are members of binary systems. Yet, the formation and early evolution of binary and multiple stars is not well understood theoretically and poorly constrained observationally. We present findings from a comprehensive spectroscopic survey for close binaries among nearly 200 members of the Chamaeleon I and Taurus-Auriga star-forming regions. We find that higher mass stars in
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Title: Magneto-optical preparation of a slow, cold and bright Ne * atomic beam. Authors: Scholz, A.; Christ, M.; Doll, D.; Ludwig, J.; Ertmer, W. Affiliation: Institut für Angewandte Physik, Universität Bonn, D-53115 Bonn, Germany. ...
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A new intelligent mobile lab (IMOLA) for the monitoring of cell physiologic parameters, i.e. extracellular acidification, cellular respiration, cell proliferation and changes in morphology/adhesion is introduced. The device works with... more
A new intelligent mobile lab (IMOLA) for the monitoring of cell physiologic parameters, i.e. extracellular acidification, cellular respiration, cell proliferation and changes in morphology/adhesion is introduced. The device works with multiparametric sensor chips directly grown with cell or tissue cultures.