X-ray structure analysis
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X-ray structure analysis results have been widely used in the pharmaceutical research, development and control, especially for mapping polymorphism, to determine the chirality of active substances, in the pharmaceutical documentation and patent policy for many years. The greatest progress in X-ray diffraction techniques has been made in improving the quality of the poor material for successful data collection (magnetically oriented microcrystal arrays, serial snapshot crystallography). Prospects of the pharmaceutical application of X-ray crystallography lie in the acceleration of data collection, time-resolved structural studies obtained from the material of pharmaceutical batches without modification, and, in addition to that, in solving structures of semi-solid and amorphous phases and monitoring structural changes in drug formulations.
- MeSH
- difrakce rentgenového záření MeSH
- duševní vlastnictví MeSH
- farmaceutická technologie MeSH
- krystalografie rentgenová * metody přístrojové vybavení využití MeSH
- léčivé přípravky * analýza MeSH
- spektrální analýza metody přístrojové vybavení využití MeSH
- stereoizomerie MeSH
- Publikační typ
- práce podpořená grantem MeSH
A mononuclear cadmium(II) complex of formula [Cd(5,5'-dmbipy)2(OAc)2]·2H2O (5,5'-dmbipy = 5,5'-dimethyl-2,2'-bipyridine and OAc = acetato ligand) has been synthesized and characterized by FT-IR, UV-Vis, 1H-NMR, elemental analysis and single-crystal X-ray structure analysis. The molecular structure of the complex shows a distorted tetragonal antiprism CdN4O4 coordination geometry around the cadmium atom, resulting in coordination by four nitrogen atoms from two 5,5'-dmbipy ligands and four oxygen atoms from two acetate anions. The interaction of this complex to FS-DNA (fish sperm DNA) has also been studied by electronic absorption, fluorescence and gel electrophoresis techniques. Binding constant (Kb), Stern-Volmer constant (Ksv), number of binding sites (n) and bimolecular quenching rate constant (kq) have been calculated from these spectroscopic data. These results have revealed that the metal complex can bind effectively to FS-DNA via groove binding. The calculated thermodynamic parameters (ΔH°, ΔS° and ΔG°) show that hydrogen bonding and van der Waals forces have an important function in the Cd(II) complex-DNA interaction. The antibacterial effects of the synthesized cadmium complex have also been examined in vitro against standard bacterial strains: one Gram-positive (Staphylococcus aureus, ATCC 25923) and one Gram-negative (Escherichia coli, ATCC 25922) bacteria, using disk diffusion and macro-dilution broth methods. The obtained results show that the Cd(II) complex exhibits a marked antibacterial activity which is significantly better than those observed for its free ligand and metal salt for both Gram-positive and Gram-negative bacteria. However, this metal complex is a more potent antibacterial agent against the Gram-positive than that of the Gram-negative bacteria.Communicated by Ramaswamy H. Sarma.
- MeSH
- algoritmy MeSH
- antibakteriální látky chemie farmakologie MeSH
- Bacteria účinky léků MeSH
- DNA chemie MeSH
- kadmium chemie MeSH
- krystalografie rentgenová MeSH
- ligandy MeSH
- magnetická rezonanční spektroskopie MeSH
- mikrobiální testy citlivosti MeSH
- molekulární modely * MeSH
- molekulární struktura MeSH
- pyridiny chemická syntéza chemie farmakologie MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- techniky syntetické chemie MeSH
- termodynamika MeSH
- vodíková vazba MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
One of the greatest enigmas of modern biology is how the geometry of muscular and skeletal structures are created and how their development is controlled during growth and regeneration. Scaling and shaping of vertebrate muscles and skeletal elements has always been enigmatic and required an advanced technical level in order to analyse the cell distribution in 3D. In this work, synchrotron X-ray computed microtomography (µCT) and chemical contrasting has been exploited for a quantitative analysis of the 3D-cell distribution in tissues of a developing salamander (Pleurodeles waltl) limb - a key model organism for vertebrate regeneration studies. We mapped the limb muscles, their size and shape as well as the number and density of cells within the extracellular matrix of the developing cartilage. By using tomographic approach, we explored the polarity of the cells in 3D, in relation to the structure of developing joints. We found that the polarity of chondrocytes correlates with the planes in joint surfaces and also changes along the length of the cartilaginous elements. Our approach generates data for the precise computer simulations of muscle-skeletal regeneration using cell dynamics models, which is necessary for the understanding how anisotropic growth results in the precise shapes of skeletal structures.
Cíl. Cílem naší retrospektivní práce bylo zhodnotit diagnostický proces pomocí zobrazovacích metod u pacientů se střevní obstrukcí. Materiál a metoda. Retrospektivně jsme posuzovali diagnostický přístup u pacientů hospitalizovaných na Chirurgické klinice pro poruchy pasáže gastrointestinálním traktem (GIT) v období let 2006-2009. Náš soubor obsahoval 374 pacientů (51,2 % žen, průměrný věk 65 let, věkový interval 19-90 let), vyloučeni byli pacienti v časném pooperačním období (3 týdny) a děti do 18 let. Hodnotili jsme indikace a nálezy na prostém rentgenovém snímku břicha (dále RTG), při kontrastním vyšetření pasáže trávicího traktu a CT bez endoluminální přípravy. Jejich výsledky jsme porovnávali s nálezy při endoskopii a operačními nálezy. Výsledky. RTG snímek břicha byl proveden 95,7% pacientům (senzitivita 80,6 %, specificita 49,5 %, NPV 66,7 % a PPV 78,6 %). Pasáž GIT ve vodě rozpustnou kontrastní látkou byla provedena celkem u 39,8 %, v 33,6 % případů byla negativní (7 falešně negativní případy potvrzené operačním nálezem, NPV - 89 %). V 47,6 % s nálezem ileózního stavu, 69 % pacientů s nálezem obstrukce při pasáži bylo operováno a 31 % pak bylo léčeno konzervativně. CT bez endoluminální přípravy bylo provedeno v 125 případech (33,4 %), ve 115 případech byla nalezena příčina obstrukce, z toho 72 nálezů bylo ověřeno operačním nálezem a nález na CT byl potvrzen ve 100 %. Závěr. Radiologické zobrazovací metody jsou nezbytné v diagnostice akutní střevní obstrukce. RTG břicha je vhodné jako vstupní vyšetření a společně s klinickým nálezem a anamnézou lze na jeho základě zvolit další vyšetřovací postup. CT je nejlepší metodou k přesnému určení příčiny obstrukce. Pasáž trávicího trávicího traktu může přispět k obnovení pasáže u pacientů s "low-grade" obstrukcí.
Aim. Aim of our retrospective study was to evaluate diagnostic management of bowel obstruction and to compare it with contemporary literature. Material and methods. We assess retrospectively the diagnostic procedure in patients hospitalized due to the suspected bowel obstruction in period 2006-2009. Our set of contains 374 patients (51,2 % female, average age 65 years, age interval 19-90 years) and children till 18 years and persons in early post-operative period (3 weeks) were excluded. The following findings were checked: plain abdominal radiography (x-ray), bowel follow-through with water-soluble contrast agent (BFT) and multidetector computed tomography (MDCT); results were compared each other and with results of endoscopy and/or laparotomy Results. 95,7% of patients underwent plain x-ray (sensitivity 80,6%, specificity 49,5%, NPV 66,7% a PPV 78,6%). The BFT was performed in 39,8% of patients, 47,6% findings were positive according to the small bowel obstruction, in 33,6% were negative respectively (7 false negative confirmed during laparotomy, NPV - 89%). 69% patients with obstruction underwent surgery and 31% were treated by conservative way. MDCT without endoluminal preparation was performed in 125 patients (33,4%), in 115 cases was found cause of obstruction. 72 patients underwent surgery and MDCT findings were confirmed in 100%. The increasing trend in MDCT indications was found. Conclusion. Plain X-ray is most often used first imaging modality in patients with suspected bowel obstruction with good possibility to triage following patient's examinations and treatment. MDCT is best method to identify cause of obstruction. Bowel follow-through could be helpful in patients with "low-grade" obstruction.
- Klíčová slova
- MDCT, pasáž trávicím traktem,
- MeSH
- akutní bolest břicha diagnóza etiologie MeSH
- anamnéza MeSH
- chirurgie trávicího traktu metody využití MeSH
- endoskopie trávicího systému metody využití MeSH
- financování organizované MeSH
- fyzikální vyšetření MeSH
- lidé MeSH
- počítačová rentgenová tomografie MeSH
- radiografie MeSH
- retrospektivní studie MeSH
- senzitivita a specificita MeSH
- statistika jako téma MeSH
- střevní obstrukce diagnóza etiologie MeSH
- výsledky a postupy - zhodnocení (zdravotní péče) MeSH
- Check Tag
- lidé MeSH
Raman microscopy permits structural analysis of protein crystals in situ in hanging drops, allowing for comparison with Raman measurements in solution. Nevertheless, the two methods sometimes reveal subtle differences in structure that are often ascribed to the water layer surrounding the protein. The novel method of drop-coating deposition Raman spectropscopy (DCDR) exploits an intermediate phase that, although nominally "dry," has been shown to preserve protein structural features present in solution. The potential of this new approach to bridge the structural gap between proteins in solution and in crystals is explored here with extrinsic protein PsbP of photosystem II from Spinacia oleracea. In the high-resolution (1.98 Å) x-ray crystal structure of PsbP reported here, several segments of the protein chain are present but unresolved. Analysis of the three kinds of Raman spectra of PsbP suggests that most of the subtle differences can indeed be attributed to the water envelope, which is shown here to have a similar Raman intensity in glassy and crystal states. Using molecular dynamics simulations cross-validated by Raman solution data, two unresolved segments of the PsbP crystal structure were modeled as loops, and the amino terminus was inferred to contain an additional beta segment. The complete PsbP structure was compared with that of the PsbP-like protein CyanoP, which plays a more peripheral role in photosystem II function. The comparison suggests possible interaction surfaces of PsbP with higher-plant photosystem II. This work provides the first complete structural picture of this key protein, and it represents the first systematic comparison of Raman data from solution, glassy, and crystalline states of a protein.
- MeSH
- aminokyselinové motivy MeSH
- fotosystém II (proteinový komplex) chemie MeSH
- krystalografie rentgenová MeSH
- molekulární modely MeSH
- molekulární sekvence - údaje MeSH
- Ramanova spektroskopie MeSH
- rostlinné proteiny chemie MeSH
- sekundární struktura proteinů MeSH
- sekvence aminokyselin MeSH
- Spinacia oleracea chemie MeSH
- terciární struktura proteinů MeSH
- vodíková vazba MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
β-Mannosidase (EC 3.2.1.25) is an important exoglycosidase specific for the hydrolysis of terminal β-linked mannoside in various oligomeric saccharide structures. β-Mannosidase from Aspergillus niger was expressed in Pichia pastoris and purified to clear homogeneity. β-Mannosidase was crystallized in the presence of D-mannose and the crystal diffracted to 2.41 Å resolution. The crystal belonged to space group P1, with unit-cell parameters a=62.37, b=69.73, c=69.90 Å, α=108.20, β=101.51, γ=103.20°. The parameters derived from the data collection indicate the presence of one molecule in the asymmetric unit.
- MeSH
- Aspergillus niger chemie enzymologie MeSH
- beta-mannosidasa chemie genetika MeSH
- fungální proteiny chemie genetika MeSH
- krystalizace MeSH
- krystalografie rentgenová MeSH
- mannosa chemie MeSH
- Pichia chemie genetika MeSH
- rekombinantní proteiny chemie genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Haloalkane dehalogenases make up an important class of hydrolytic enzymes which catalyse the cleavage of carbon-halogen bonds in halogenated aliphatic compounds. There is growing interest in these enzymes owing to their potential use in environmental and industrial applications. The haloalkane dehalogenase DhaA from Rhodococcus rhodochrous NCIMB 13064 can slowly detoxify the industrial pollutant 1,2,3-trichloropropane (TCP). Structural analysis of this enzyme complexed with target ligands was conducted in order to obtain detailed information about the structural limitations of its catalytic properties. In this study, the crystallization and preliminary X-ray analysis of complexes of wild-type DhaA with 2-propanol and with TCP and of complexes of the catalytically inactive variant DhaA13 with the dye coumarin and with TCP are described. The crystals of wild-type DhaA were plate-shaped and belonged to the triclinic space group P1, while the variant DhaA13 can form prism-shaped crystals belonging to the orthorhombic space group P2(1)2(1)2(1) as well as plate-shaped crystals belonging to the triclinic space group P1. Diffraction data for crystals of wild-type DhaA grown from crystallization solutions with different concentrations of 2-propanol were collected to 1.70 and 1.26 Å resolution, respectively. A prism-shaped crystal of DhaA13 complexed with TCP and a plate-shaped crystal of the same variant complexed with the dye coumarin diffracted X-rays to 1.60 and 1.33 Å resolution, respectively. A crystal of wild-type DhaA and a plate-shaped crystal of DhaA13, both complexed with TCP, diffracted to atomic resolutions of 1.04 and 0.97 Å, respectively.
- MeSH
- 2-propanol MeSH
- bakteriální proteiny chemie MeSH
- difrakce rentgenového záření MeSH
- hydrolasy chemie genetika metabolismus MeSH
- hydrolýza MeSH
- izoenzymy chemie genetika MeSH
- katalýza MeSH
- krystalizace MeSH
- krystalografie rentgenová metody MeSH
- ligandy MeSH
- propan analogy a deriváty MeSH
- Rhodococcus enzymologie genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
