24 research outputs found
Inherited epithelial transporter disorders—an overview
Summary: In the late 1990s, the identification of transporters and transporter-associated genes progressed substantially due to the development of new cloning approaches such as expression cloning and, subsequently, to the implementation of the human genome project. Since then, the role of many transporter genes in human diseases has been elucidated. In this overview, we focus on inherited disorders of epithelial transporters. In particular, we review genetic defects of the genes encoding glucose transporters (SLC2 and SLC5 families) and amino acid transporters (SLC1, SLC3, SLC6 and SLC7 families
Synthetic X-ray and radio maps for two different models of Stephan's Quintet
We present simulations of the compact galaxy group Stephan's Quintet (SQ)
including magnetic fields, performed with the N-body/smoothed particle
hydrodynamics (SPH) code \textsc{Gadget}. The simulations include radiative
cooling, star formation and supernova feedback. Magnetohydrodynamics (MHD) is
implemented using the standard smoothed particle magnetohydrodynamics (SPMHD)
method. We adapt two different initial models for SQ based on Renaud et al. and
Hwang et al., both including four galaxies (NGC 7319, NGC 7320c, NGC 7318a and
NGC 7318b). Additionally, the galaxies are embedded in a magnetized, low
density intergalactic medium (IGM). The ambient IGM has an initial magnetic
field of G and the four progenitor discs have initial magnetic fields
of G. We investigate the morphology, regions of star
formation, temperature, X-ray emission, magnetic field structure and radio
emission within the two different SQ models. In general, the enhancement and
propagation of the studied gaseous properties (temperature, X-ray emission,
magnetic field strength and synchrotron intensity) is more efficient for the SQ
model based on Renaud et al., whose galaxies are more massive, whereas the less
massive SQ model based on Hwang et al. shows generally similar effects but with
smaller efficiency. We show that the large shock found in observations of SQ is
most likely the result of a collision of the galaxy NGC 7318b with the IGM.
This large group-wide shock is clearly visible in the X-ray emission and
synchrotron intensity within the simulations of both SQ models. The order of
magnitude of the observed synchrotron emission within the shock front is
slightly better reproduced by the SQ model based on Renaud et al., whereas the
distribution and structure of the synchrotron emission is better reproduced by
the SQ model based on Hwang et al..Comment: 20 pages, 15 figures, accepted to MNRA
A model for the compressible, viscoelastic behavior of human amnion addressing tissue variability through a single parameter
A viscoelastic, compressible model is proposed to rationalize the recently reported response of human amnion in multiaxial relaxation and creep experiments. The theory includes two viscoelastic contributions responsible for the short- and long-term time- dependent response of the material. These two contributions can be related to physical processes: water flow through the tissue and dissipative characteristics of the collagen fibers, respectively. An accurate agreement of the model with the mean tension and kinematic response of amnion in uniaxial relaxation tests was achieved. By variation of a single linear factor that accounts for the variability among tissue samples, the model provides very sound predictions not only of the uniaxial relaxation but also of the uniaxial creep and strip-biaxial relaxation behavior of individual samples. This suggests that a wide range of viscoelastic behaviors due to patient-specific variations in tissue composition
Differential expression and activity of 11beta-hydroxysteroid dehydrogenase in human placenta and fetal membranes from pregnancies with intrauterine growth restriction
OBJECTIVES: To study the expression and the function of the 11beta-hydroxysteroid dehydrogenase enzyme 1 (11beta-HSD1) and 2 (11beta-HSD2) in placenta and the fetal membranes from pregnancies with intrauterine growth restriction (IUGR) and from controls. METHODS: Amnion, chorion, decidua and cotyledon were separated from placenta; mRNA was analyzed by TaqMan real-time technology and proteins by Western blot; enzyme activities were measured by the conversion of 3H-cortisol to 3H-cortisone and vice versa. RESULTS: Predominant mRNA expression (p < 0.001) was found for 11beta-HSD1 in chorion and for 11beta-HSD2 in decidua and cotyledon. In pregnancies with IUGR, 11beta-HSD1 was upregulated in chorion (mean DeltaCt 11beta-HSD:18S mRNA 193.5 vs. 103.0 in controls respectively, p < 0.05) and 11beta-HSD2 was downregulated in decidua (mean DeltaCt 11beta-HSD2:18S mRNA 0.18 vs. 15.88 in controls respectively, p < 0.05). 11beta-HSD1 protein levels were reduced in amnion and 11beta-HSD1 and 11beta-HSD2 oxidase activity in decidua and cotyledon were reduced from pregnancies with IUGR. CONCLUSION: Reduced synthesis or activity of 11beta-HSD1 or 2 in cases of IUGR is shown in some but not in all tissues. The local mRNA expression of 11beta-HSD1 in chorion may reflect a mechanism on the post-transcriptional gene regulation to stimulate the formation of cortisone in IUGR. To provoke increasing activity with oxidase stimulators could be a future therapy in cases of IUGR
Inherited epithelial transporter disorders-an overview
In the late 1990s, the identification of transporters and transporter-associated genes progressed substantially due to the development of new cloning approaches such as expression cloning and, subsequently, to the implementation of the human genome project. Since then, the role of many transporter genes in human diseases has been elucidated. In this overview, we focus on inherited disorders of epithelial transporters. In particular, we review genetic defects of the genes encoding glucose transporters (SLC2 and SLC5 families) and amino acid transporters (SLC1, SLC3, SLC6 and SLC7 families)
Zinc transporters in prostate cancer
Prostate cancer is a major health concern as it has the second highest incidence rate among cancers in men. Despite progress in tumor diagnostics and therapeutic approaches, prognosis for men with advanced disease remains poor. In this review we provide insight into the changes of the intermediary metabolism in normal prostate and prostate cancer. In contrast to normal cells, prostate cancer cells are reprogrammed for optimal energy-efficiency with a functional Krebs cycle and minimal apoptosis rates. A key element in this relationship is the uniquely high zinc level of normal prostate epithelial cells. Zinc is transported by the SLC30 and SLC39 families of zinc transporters. However, in prostate cancer the intracellular zinc content is remarkably reduced and expression levels of certain zinc transporters are altered. Here, we summarize the role of different zinc transporters in the development of prostate cancer
Do Himalayan treelines respond to recent climate change? An evaluation of sensitivity indicators
Climate warming is expected to induce treelines to
advance to higher elevations. Empirical studies in diverse mountain ranges,
however, give evidence of both advancing alpine treelines and rather
insignificant responses. The inconsistency of findings suggests distinct
differences in the sensitivity of global treelines to recent climate change.
It is still unclear where Himalayan treeline ecotones are located along the
response gradient from rapid dynamics to apparently complete inertia. This
paper reviews the current state of knowledge regarding sensitivity and
response of Himalayan treelines to climate warming, based on extensive field
observations, published results in the widely scattered literature, and
novel data from ongoing research of the present authors.
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Several sensitivity indicators such as treeline type, treeline form,
seed-based regeneration, and growth patterns are evaluated. Since most
Himalayan treelines are anthropogenically depressed, observed advances are
largely the result of land use change. Near-natural treelines are usually
krummholz treelines, which are relatively unresponsive to climate change. Nevertheless, intense
recruitment of treeline trees suggests a great potential for future treeline
advance. Competitive abilities of seedlings within krummholz thickets and
dwarf scrub heaths will be a major source of variation in treeline dynamics.
Tree growth–climate relationships show mature treeline trees to be
responsive to temperature change, in particular in winter and pre-monsoon
seasons. High pre-monsoon temperature trends will most likely drive tree
growth performance in the western and central Himalaya. Ecological niche modelling
suggests that bioclimatic conditions for a range expansion of treeline trees
will be created during coming decades