Grid Approach to Path Integral Monte Carlo Calculations

Approach taken for the gridification of the developed Monte Carlo code for calculation of path integrals is described. Brief introduction to path integrals and Grids is given, and details on the implementation of SPEEDUP in the Grid environment are described. The numerical results obtained by the gridified version of the application are shortly presented, demonstrating its usefulness in the research in physics and related areas

Stereospecific Synthesis of Substituted Sulfamidates as Privileged Morpholine Building Blocks

Morpholine is a heterocyclic moiety that is widely used in medicinal chemistry as a building block. It has unique physicochemical properties, as it can improve both pharmacokinetic and pharmacodynamic properties of active pharmaceutical ingredients. However, the efficient synthesis of enantiomerically pure morpholine building blocks remains challenging. Herein, we report the synthesis of optically pure 3-hydroxymethylmorpholine building blocks, as well as their sulfamidates, exploiting a stereospecific strategy from chiral pool material

Untreated PKU patients without intellectual disability: What do they teach us?

Phenylketonuria (PKU) management is aimed at preventing neurocognitive and psychosocial dysfunction by keeping plasma phenylalanine concentrations within the recommended target range. It can be questioned, however, whether universal plasma phenylalanine target levels would result in optimal neurocognitive outcomes for all patients, as similar plasma phenylalanine concentrations do not seem to have the same consequences to the brain for each PKU individual. To better understand the inter-individual differences in brain vulnerability to high plasma phenylalanine concentrations, we aimed to identify untreated and/or late-diagnosed PKU patients with near-normal outcome, despite high plasma phenylalanine concentrations, who are still alive. In total, we identified 16 such cases. While intellectual functioning in these patients was relatively unaffected, they often did present other neurological, psychological, and behavioral problems. Thereby, these “unusual” PKU patients show that the classical symptomatology of untreated or late-treated PKU may have to be rewritten. Moreover, these cases show that a lack of intellectual dysfunction despite high plasma phenylalanine concentrations does not necessarily imply that these high phenylalanine concentrations have not been toxic to the brain. Also, these cases may suggest that different mechanisms are involved in PKU pathophysiology, of which the relative importance seems to differ between patients and possibly also with increasing age. Further research should aim to better distinguish PKU patients with respect to their cerebral effects to high plasma phenylalanine concentrations

Untreated PKU patients without intellectual disability: what do they teach us?

Phenylketonuria (PKU) management is aimed at preventing neurocognitive and psychosocial dysfunction by keeping plasma phenylalanine concentrations within the recommended target range. It can be questioned, however, whether universal plasma phenylalanine target levels would result in optimal neurocognitive outcomes for all patients, as similar plasma phenylalanine concentrations do not seem to have the same consequences to the brain for each PKU individual. To better understand the inter-individual differences in brain vulnerability to high plasma phenylalanine concentrations, we aimed to identify untreated and/or late-diagnosed PKU patients with near-normal outcome, despite high plasma phenylalanine concentrations, who are still alive. In total, we identified 16 such cases. While intellectual functioning in these patients was relatively unaffected, they often did present other neurological, psychological, and behavioral problems. Thereby, these "unusual" PKU patients show that the classical symptomatology of untreated or late-treated PKU may have to be rewritten. Moreover, these cases show that a lack of intellectual dysfunction despite high plasma phenylalanine concentrations does not necessarily imply that these high phenylalanine concentrations have not been toxic to the brain. Also, these cases may suggest that different mechanisms are involved in PKU pathophysiology, of which the relative importance seems to differ between patients and possibly also with increasing age. Further research should aim to better distinguish PKU patients with respect to their cerebral effects to high plasma phenylalanine concentrations

Optimization of breast cancer excision by intraoperative ultrasound and marking needle - technique description and feasibility

BACKGROUND: We present a surgical technique and the preliminary results of breast cancer excision after insertion of a specially constructed marking needle into the tumor, controlled by intraoperative ultrasound. Resection margins were projected in six directions by ultrasound measurements, determined in relation to the needle, and resection was done in accordance with those measurements. The main objective was to obtain resection margins similar (equal) to those projected by intraoperative ultrasound (10 mm). METHODS: Detailed description of the technique is given. Thirty-two female patients undergoing breast-conserving surgery, up to 30 mm in diameter, for palpable and non-palpable invasive breast cancer, were operated on using this technique. Its feasibility was tested by analyzing the success (rate) of needle placement in the tumor, the measurements executed, and the performance of the excision. RESULTS: All stages of the technique were successfully performed to completion on all 32 patients. The procedure of needle placement and ultrasound measurement of distances took 11 min on average (between 6 and 20 min). The average distance of the tumor margin from the resection margin was 12.9 mm (2 to 30 mm, 95% confidence interval [11.9, 14.06]). There was one patient with a positive resection margin (3%). CONCLUSIONS: The technique of excising palpable and non-palpable breast cancer by intraoperative ultrasound and an especially constructed marking needle is feasible and comfortable to perform. Preliminary results imply that resection volume can be rationalized, with the same or better oncological safety

Engineered Protein Nano-Compartments for Targeted Enzyme Localization

Compartmentalized co-localization of enzymes and their substrates represents an attractive approach for multi-enzymatic synthesis in engineered cells and biocatalysis. Sequestration of enzymes and substrates would greatly increase reaction efficiency while also protecting engineered host cells from potentially toxic reaction intermediates. Several bacteria form protein-based polyhedral microcompartments which sequester functionally related enzymes and regulate their access to substrates and other small metabolites. Such bacterial microcompartments may be engineered into protein-based nano-bioreactors, provided that they can be assembled in a non-native host cell, and that heterologous enzymes and substrates can be targeted into the engineered compartments. Here, we report that recombinant expression of Salmonella enterica ethanolamine utilization (eut) bacterial microcompartment shell proteins in E. coli results in the formation of polyhedral protein shells. Purified recombinant shells are morphologically similar to the native Eut microcompartments purified from S. enterica. Surprisingly, recombinant expression of only one of the shell proteins (EutS) is sufficient and necessary for creating properly delimited compartments. Co-expression with EutS also facilitates the encapsulation of EGFP fused with a putative Eut shell-targeting signal sequence. We also demonstrate the functional localization of a heterologous enzyme (β-galactosidase) targeted to the recombinant shells. Together our results provide proof-of-concept for the engineering of protein nano-compartments for biosynthesis and biocatalysis

Heme Degrading Protein HemS Is Involved in Oxidative Stress Response of Bartonella henselae

Bartonellae are hemotropic bacteria, agents of emerging zoonoses. These bacteria are heme auxotroph Alphaproteobacteria which must import heme for supporting their growth, as they cannot synthesize it. Therefore, Bartonella genome encodes for a complete heme uptake system allowing the transportation of this compound across the outer membrane, the periplasm and the inner membranes. Heme has been proposed to be used as an iron source for Bartonella since these bacteria do not synthesize a complete system required for iron Fe3+uptake. Similarly to other bacteria which use heme as an iron source, Bartonellae must transport this compound into the cytoplasm and degrade it to allow the release of iron from the tetrapyrrole ring. For Bartonella, the gene cluster devoted to the synthesis of the complete heme uptake system also contains a gene encoding for a polypeptide that shares homologies with heme trafficking or degrading enzymes. Using complementation of an E. coli mutant strain impaired in heme degradation, we demonstrated that HemS from Bartonella henselae expressed in E. coli allows the release of iron from heme. Purified HemS from B. henselae binds heme and can degrade it in the presence of a suitable electron donor, ascorbate or NADPH-cytochrome P450 reductase. Knocking down the expression of HemS in B. henselae reduces its ability to face H2O2 induced oxidative stress