192 research outputs found
Challenging complications of treatment â human herpes virus 6 encephalitis and pneumonitis in a patient undergoing autologous stem cell transplantation for relapsed Hodgkin's disease: a case report
<p>Abstract</p> <p>Background</p> <p>Reactivation of human herpesvirus 6 (HHV-6) occurs frequently in patients after allogeneic stem cell transplantation and is associated with bone-marrow suppression, enteritis, pneumonitis, pericarditis and also encephalitis. After autologous stem cell transplantation or intensive polychemotherapy HHV-6 reactivation is rarely reported.</p> <p>Case report</p> <p>This case demonstrates a severe symptomatic HHV-6 infection with encephalitis and pneumonitis after autologous stem cell transplantation of a patient with relapsed Hodgkin's disease.</p> <p>Conclusion</p> <p>Careful diagnostic work up in patients with severe complications after autologous stem cell transplantation is mandatory to identify uncommon infections.</p
Structural insights into the light-driven auto-assembly process of the water- oxidizing Mn4CaO5-cluster in photosystem II
In plants, algae and cyanobacteria, Photosystem II (PSII) catalyzes the light-
driven splitting of water at a protein-bound Mn4CaO5-cluster, the water-
oxidizing complex (WOC). In the photosynthetic organisms, the light-driven
formation of the WOC from dissolved metal ions is a key process because it is
essential in both initial activation and continuous repair of PSII. Structural
information is required for understanding of this chaperone-free metal-cluster
assembly. For the first time, we obtained a structure of PSII from
Thermosynechococcus elongatus without the Mn4CaO5-cluster. Surprisingly,
cluster-removal leaves the positions of all coordinating amino acid residues
and most nearby water molecules largely unaffected, resulting in a pre-
organized ligand shell for kinetically competent and error-free photo-assembly
of the Mn4CaO5-cluster. First experiments initiating (i) partial disassembly
and (ii) partial re-assembly after complete depletion of the Mn4CaO5-cluster
agree with a specific bi-manganese cluster, likely a di-”-oxo bridged pair of
Mn(III) ions, as an assembly intermediate
Protein crystallization and initial neutron diffraction studies of the photosystem II subunit PsbO
The PsbO protein of photosystem II stabilizes the active-site manganese cluster and is thought to act as a proton antenna. To enable neutron diffraction studies, crystals of the ÎČ-barrel core of PsbO were grown in capillaries. The crystals were optimized by screening additives in a counter-diffusion setup in which the protein and reservoir solutions were separated by a 1% agarose plug. Crystals were cross-linked with glutaraldehyde. Initial neutron diffraction data were collected from a 0.25â
mm3 crystal at room temperature using the MaNDi single-crystal diffractometer at the Spallation Neutron Source, Oak Ridge National Laboratory
Sum rules for isospin centroids in pick-up reactions on general multishell target states
Sum Rules equations for pick-up reactions are presented for the first time
for the energy centroids of states both for the isospin T_< (\equiv T_0 - 1
\over 2) and T_> (\equiv T_0 + {1 \over 2}) of the final nucleus when a nucleon
is picked up from a general multishell target state with isospin T_0. These
equations contain two-body correlation terms, , which, at the present
moment, are difficult to handle analytically. These terms are managed by
combining these equations with the known stripping reactions equations. Sample
applications of these equations to experimental data are presented.Comment: 11 pages, LaTe
pHâdependent protonation of surface carboxylate groups in PsbO enables local buffering and triggers structural changes
Photosystemâ
II (PSII) catalyzes the splitting of water, releasing protons and dioxygen. Its highly conserved subunit PsbO extends from the oxygenâevolving center (OEC) into the thylakoid lumen and stabilizes the catalytic Mn4CaO5 cluster. The high degree of conservation of accessible negatively charged surface residues in PsbO suggests additional functions, as local pH buffer or by affecting the flow of protons. For this discussion, we provide an experimental basis, through the determination of pKa values of waterâaccessible aspartate and glutamate sideâchain carboxylate groups by means of NMR. Their distribution is strikingly uneven, with high pKa values around 4.9 clustered on the luminal PsbO side and values below 3.5 on the side facing PSII. pHâdependent changes in backbone chemical shifts in the area of the lumenâexposed loops are observed, indicating conformational changes. In conclusion, we present a siteâspecific analysis of carboxylate group proton affinities in PsbO, providing a basis for further understanding of proton transport in photosynthesis
Comparisons among the five ground-motion models developed using RESORCE for the prediction of response spectral accelerations due to earthquakes in Europe and the Middle East
This article presents comparisons among the five ground-motion models described in other articles within this special issue, in terms of data selection criteria, characteristics of the models and predicted peak ground and response spectral accelerations. Comparisons are also made with predictions from the Next Generation Attenuation (NGA) models to which the models presented here have similarities (e.g. a common master database has been used) but also differences (e.g. some models in this issue are nonparametric). As a result of the differing data selection criteria and derivation techniques the predicted median ground motions show considerable differences (up to a factor of two for certain scenarios), particularly for magnitudes and distances close to or beyond the range of the available observations. The predicted influence of style-of-faulting shows much variation among models whereas site amplification factors are more similar, with peak amplification at around 1s. These differences are greater than those among predictions from the NGA models. The models for aleatory variability (sigma), however, are similar and suggest that ground-motion variability from this region is slightly higher than that predicted by the NGA models, based primarily on data from California and Taiwan
Insights into energy balance dysregulation from a mouse model of methylmalonic aciduria
Inherited disorders of mitochondrial metabolism, including isolated methylmalonic aciduria, present unique challenges to energetic homeostasis by disrupting energy-producing pathways. To better understand global responses to energy shortage, we investigated a hemizygous mouse model of methylmalonyl-CoA mutase (Mmut)âtype methylmalonic aciduria. We found Mmut mutant mice to have reduced appetite, energy expenditure and body mass compared with littermate controls, along with a relative reduction in lean mass but increase in fat mass. Brown adipose tissue showed a process of whitening, in line with lower body surface temperature and lesser ability to cope with cold challenge. Mutant mice had dysregulated plasma glucose, delayed glucose clearance and a lesser ability to regulate energy sources when switching from the fed to fasted state, while liver investigations indicated metabolite accumulation and altered expression of peroxisome proliferatorâactivated receptor and Fgf21-controlled pathways. Together, these shed light on the mechanisms and adaptations behind energy imbalance in methylmalonic aciduria and provide insight into metabolic responses to chronic energy shortage, which may have important implications for disease understanding and patient management
Growth-factor dependent expression of the translationally controlled tumour protein TCTP is regulated through the PI3-K/Akt/mTORC1 signalling pathway
Advanced transfer printing with in-situ optical monitoring for the integration of micron-scale devices
Transfer printing integration of planar membrane devices on photonic and electronic circuits is becoming a well established technology. Typical systems incorporate a single planar layer printed into full contact with the host substrate. In this work we present an advanced transfer print system that enables printing of optical devices in non-planar geometries and allows in-situ optical monitoring of devices. We show micro-resonators with air-clad whispering gallery modes coupled to on-chip waveguides, inverted device printing and three dimensionally assembled micro-cavities incorporating semiconductor micro-lenses and nanowire lasers. We demonstrate printing onto non-standard substrates including optical chip facets and single-mode fibre ends. The optical fibre printing was carried out with alignment assistance from in-situ optical coupling through the transfer printing system in real-time allowing active alignment of the system
Insights into energy balance dysregulation from a mouse model of methylmalonic aciduria
Inherited disorders of mitochondrial metabolism, including isolated methylmalonic aciduria (MMAuria), present unique challenges to energetic homeostasis by disrupting energy producing pathways. To better understand global responses to energy shortage, we investigated a hemizygous mouse model of methylmalonyl-CoA mutase (Mmut) type MMAuria. We found Mmut mutant mice to have reduced appetite, energy expenditure and body mass compared to littermate controls, along with a relative reduction in lean mass but increase in fat mass. Brown adipose tissue showed a process of whitening, in line with lower body surface temperature and lesser ability to cope with cold challenge. Mutant mice had dysregulated plasma glucose, delayed glucose clearance and a lesser ability to regulate energy sources when switching from the fed to fasted state, while liver investigations indicated metabolite accumulation and altered expression of peroxisome proliferator-activated receptor and Fgf21-controlled pathways. Together, these indicate hypometabolism, energetic inflexibility and increased stores at the expense of active tissue as energy shortage consequences
- âŠ