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Methodische Herausforderungen und Möglichkeiten bei
gesundheitsbezogenen (Forschungs-)Projekten für Menschen mit
Migrationshintergrund. DAS GESUNDHEITSWESEN 2022. [DOI: 10.1055/s-0042-1753908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Wissen Mitglieder von Selbsthilfegruppen mehr über Krebs als
Nicht-Mitglieder? Ergebnisse einer bundesweiten Querschnittsstudie mit 1.121
Krebspatient:innen. DAS GESUNDHEITSWESEN 2022. [DOI: 10.1055/s-0042-1753643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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3
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Evaluation eines Versorgungsangebotes für Schwangere ohne
Papiere – AnDOCken. DAS GESUNDHEITSWESEN 2022. [DOI: 10.1055/s-0042-1753911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Development and psychometric properties of a brief generic cancer knowledge scale for patients (BCKS-10). Cancer Causes Control 2022; 33:1173-1179. [PMID: 35829829 PMCID: PMC9277979 DOI: 10.1007/s10552-022-01601-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 06/21/2022] [Indexed: 11/27/2022]
Abstract
Purpose This study aims to introduce the development and psychometric properties of a brief generic cancer knowledge scale for patients (BCKS-10) that includes different elements of knowledge and skills (terminology, diagnosis, treatment, prevention, and numeracy). Although cancer knowledge is a central dimension of cancer literacy, most previous studies either investigated cancer knowledge among the general population, or among patients with a specific cancer diagnosis. Methods Qualitative interviews (n = 11) and a quantitative survey (n = 267) among peer support group leaders were conducted to further develop the BCKS-10 after literature screening. n = 500 patients with cancer were recruited across Germany between October 2020 and February 2021. Construct validity, item discrimination and reliability were tested. Results ANOVA revealed no significant differences of the knowledge score between various cancer sites, a significant positive association with education, and a negative association with migration background by trend supporting construct validity. In terms of item discrimination, the corrected item-total correlation of 8 out of 10 items were above the threshold of 0.3. Cronbach’s alpha of about 0.68 revealed an acceptable internal consistency as the tool is brief and consists of different dimensions. Conclusion Overall, the findings show that the BCKS-10 is a suitable tool to briefly assess cancer knowledge among patients independent of cancer site. However, further surveys have to be conducted to validate the psychometric properties and enhance the BCKS-10. Supplementary Information The online version contains supplementary material available at 10.1007/s10552-022-01601-x.
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Endomyocardial Biopsy - A Source of Heartache. J Heart Lung Transplant 2018. [DOI: 10.1016/j.healun.2018.01.997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Function-structure connectivity in patients with severe brain injury as measured by MRI-DWI and FDG-PET. Hum Brain Mapp 2018; 37:3707-3720. [PMID: 27273334 DOI: 10.1002/hbm.23269] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/12/2016] [Accepted: 05/16/2016] [Indexed: 02/05/2023] Open
Abstract
A vast body of literature exists showing functional and structural dysfunction within the brains of patients with disorders of consciousness. However, the function (fluorodeoxyglucose FDG-PET metabolism)-structure (MRI-diffusion-weighted images; DWI) relationship and how it is affected in severely brain injured patients remains ill-defined. FDG-PET and MRI-DWI in 25 severely brain injured patients (19 Disorders of Consciousness of which 7 unresponsive wakefulness syndrome, 12 minimally conscious; 6 emergence from minimally conscious state) and 25 healthy control subjects were acquired here. Default mode network (DMN) function-structure connectivity was assessed by fractional anisotropy (FA) and metabolic standardized uptake value (SUV). As expected, a profound decline in regional metabolism and white matter integrity was found in patients as compared with healthy subjects. Furthermore, a function-structure relationship was present in brain-damaged patients between functional metabolism of inferior-parietal, precuneus, and frontal regions and structural integrity of the frontal-inferiorparietal, precuneus-inferiorparietal, thalamo-inferioparietal, and thalamofrontal tracts. When focusing on patients, a stronger relationship between structural integrity of thalamo-inferiorparietal tracts and thalamic metabolism in patients who have emerged from the minimally conscious state as compared with patients with disorders of consciousness was found. The latter finding was in line with the mesocircuit hypothesis for the emergence of consciousness. The findings showed a positive function-structure relationship within most regions of the DMN. Hum Brain Mapp 37:3707-3720, 2016. © 2016 Wiley Periodicals, Inc.
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Vergleich EMT-spezifischer Genexpressionmuster einer neuen „aggressiven“ MCF-7 Zelllinie mit der Wildtyp MCF-7 Zelllinie. Geburtshilfe Frauenheilkd 2014. [DOI: 10.1055/s-0034-1388376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Asymmetric grazing incidence small angle x-ray scattering and anisotropic domain wall motion in obliquely grown nanocrystalline Co films. NANOTECHNOLOGY 2014; 25:335704. [PMID: 25074483 DOI: 10.1088/0957-4484/25/33/335704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Strong asymmetries have been observed in grazing incidence small angle x-ray scattering (GISAXS) in situ patterns obtained from 30 nm-thick nanocrystalline Co films prepared by oblique sputtering (15°-75° off-sample normal). These asymmetries have been qualitatively simulated by a simple model consisting of an ensemble of 8 nm-wide inclined Co nanocolumns. It is found that narrow inclined features appear in the diffuse background resembling those characteristic of faceted systems, which can be used to obtain straightforward non-destructive estimations of buried nanocolumnar grains inclination, even for oblique angles below 45°, when the stronger and broader asymmetric features of the pattern are not yet fully formed. Furthermore, using magneto-optical microscopy, a marked change in the magnetic domain's nucleation and growth process has been observed in the sample prepared at 75°, with the stronger GISAXS asymmetries. Easy axis magnetization reversal starts by a random and homogeneous nucleation of small (∼μm) elongated domains aligned with the nanocolumn's long axis and proceeds through the preferred propagation of head-to-head domain walls (DWs) along the applied field direction. This peculiar magnetic behavior indicates that the strongly anisotropic nanostructuring created by the oblique growth process is equivalent, from a magnetic point of view, to an array of self-assembled buried nanowires. These results show how GISAXS and magneto-optical microscopy can be combined as a powerful tool for correlating the morphology and magnetism of thin nanostructured systems.
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Zur Chemie der Ketene / Chemistry of Ketenes. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES 2014. [DOI: 10.1515/znb-1972-0509] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Phenylmalonylchloride reacts with sodium acetate in boiling benzene if possible via a dimeric phenylketenecarboxylic acid to give 4-acetoxy-3,6,7-triphenyl-3,6-cycloheptadiene-1,2,5-trion. The structure of this compound is deduced by mass spectrometry. Analogous compounds are obtained with the sodium salts of other carboxylic acids. A reaction mechanism is proposed.
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Abstract
The reaction of thiourea with C3O2 yields a pyrimidothiazine derivative as a 1:2 adduct. An isomeric pyronopyrimidine is obtained by the action of C3O2 on thiobarbituric acid. The structure of the reaction products of thioamides and C3O2 has been reinvestigated.
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Kinetik der Reaktion von katalytisch aktiven Imidazol-SH-Verbindungen mit Bromacetamid. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/znb-1970-1220] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Die Geschwindigkeitskonstanten zweiter Ordnung für die Reaktion einfacher SH-Verbindungen sowie Imidazol-SH-Verbindungen mit Bromacetamid bei pH 7 und verschiedenen Temperaturen wurden bestimmt und daraus die Aktivierungsenergien sowie mit Hilfe der pKSH-Werte die pH-unabhängigen Geschwindigkeitskonstanten ermittelt. Die Ergebnisse zeigen, daß die nucleophile Reaktivität von SH-Gruppen durch ideal benachbarte Imidazolreste erhöht werden kann. Der Mechanismus dieser Aktivierung wird kurz diskutiert. - Eine nähere Untersuchung der Reaktivität von 4-Brom-5-nitroimidazol, das in der Literatur als Alkylierungsmittel vorgeschlagen wurde, zeigte, daß diese Verbindung unter den gewählten Bedingungen nicht mit SH-Gruppen reagiert
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Abstract
A tunable two-color multilayer Bragg coating capable of simultaneously reflecting the fundamental and the third harmonic of an x-ray free-electron laser at the same angle and with high reflectance R>0.70 is presented. The novel coating will enable two-color x-ray pump/x-ray probe experiments. This mirror consists of a Si substrate that is coated with two different types of multilayer systems, Mo/B4C layers with a periodicity of d=3. nm directly on the substrate and Ni/B4C layers with a periodicity of d=11.85 nm on top. Fundamental radiation with photon energies between 3 and 9 keV is reflected by a Ni/B4C multilayer system while the third harmonic (9 keV<hν<27 keV) passes this system and is reflected by the Mo/B4C multilayers. The principle has successfully been proven at the beamline BM05 at ESRF.
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Evolution of surface morphology at the early stage of Al2O3 film growth on a rough substrate. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:345003. [PMID: 21403247 DOI: 10.1088/0953-8984/22/34/345003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We present an experimental study of the evolution of the surface of a growing film as a function of the statistical parameters of the virgin substrate roughness. The growth of sputter-deposited Al(2)O(3) films onto Si substrates was followed in situ using an x-ray scattering technique. Despite the use of substrates presenting different roughness correlation length and crystallographic orientation, the evolution of the film roughness is demonstrated to obey the same scaling law, i.e., with the same static and dynamic exponents. Approaches to accurately determine the scaling exponents from x-ray scattering data are discussed.
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Comparative study of multilayers used in monochromators for synchrotron-based coherent hard X-ray imaging. JOURNAL OF SYNCHROTRON RADIATION 2010; 17:496-510. [PMID: 20567082 DOI: 10.1107/s0909049510011623] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Accepted: 03/26/2010] [Indexed: 05/29/2023]
Abstract
A systematic study is presented in which multilayers of different composition (W/Si, Mo/Si, Pd/B(4)C), periodicity (from 2.5 to 5.5 nm) and number of layers have been characterized. In particular, the intrinsic quality (roughness and reflectivity) as well as the performance (homogeneity and coherence of the outgoing beam) as a monochromator for synchrotron radiation hard X-ray micro-imaging are investigated. The results indicate that the material composition is the dominating factor for the performance. By helping scientists and engineers specify the design parameters of multilayer monochromators, these results can contribute to a better exploitation of the advantages of multilayer monochromators over crystal-based devices; i.e. larger spectral bandwidth and high photon flux density, which are particularly useful for synchrotron-based micro-radiography and -tomography.
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Increased Mycophenolic Acid Exposure in Stable Kidney Transplant Recipients on Tacrolimus as Compared With Those on Sirolimus: Implications for Pharmacokinetics. Clin Pharmacol Ther 2009; 86:411-5. [DOI: 10.1038/clpt.2009.129] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Enhancement of antiferromagnetic coupling in magnetic multilayers by low energy ion beam substrate nanopatterning. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:224024. [PMID: 21715762 DOI: 10.1088/0953-8984/21/22/224024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Ion beam irradiation has been shown to be an interesting tool for tailoring the magnetic properties of thin films and multilayers. The modified properties include magnetic anisotropy, interlayer exchange coupling, exchange bias, magnetic domain structure and magnetization reversal. In this work, new results are shown concerning the enhancement, by one order of magnitude, of the antiferromagnetic coupling strength in amorphous CoSi/Si multilayers by irradiating Si(100) substrates with 1 keV Ar(+) ions. The ion beam exposure induces an increase of the substrate roughness, from 0.07 to 0.88 nm, which enhances antiferromagnetic coupling in the magnetic multilayers grown on top. One possible mechanism governing this enhancement is discussed, related to the formation of magnetic/non-magnetic regions where dipolar interactions could stabilize the antiferromagnetic alignment. The presence of non-magnetic regions is suggested by the observed trend to superparamagnetism, and is expected since the Curie temperature of the amorphous CoSi alloy used is slightly above but very close to room temperature. Accordingly, small fluctuations in the local composition, leading to an enrichment of Si, would produce non-magnetic regions enabling dipolar interactions to take place. Furthermore, the ion beam induced increase of roughness makes surface diffusion of the atoms arriving at the sample difficult, favoring the formation of local non-magnetic inhomogeneities. Finally, the role of other possible mechanisms to enhance antiferromagnetic coupling is also briefly discussed.
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X-ray structure analysis of free-standing lipid membranes facilitated by micromachined apertures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:4952-4958. [PMID: 18370435 DOI: 10.1021/la703704x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Silicon and Teflon substrates have been structured by wet etching and a focused ion beam (FIB) to obtain very defined, clean apertures. Planar, free-standing lipid membranes (black lipid membranes (BLM)) with enhanced long-term stability have been prepared on these apertures by the methods of Montal and Müller(1,2) as well as Müller and Rudin.(3) The stability and geometric control enables the use of X-ray analysis of free-standing single bilayers. With the presented setup, simultaneous structural and electrophysiological measurements will become feasible.
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Abstract
Kidney transplantation is the best option for all patients with terminal renal failure. Kidney transplantation is not only associated with an improved quality of life in comparison to all other renal replacement therapies, this method also offers a significantly extended lifespan. Therefore, the option for transplantation has to be verified for every patient with renal failure. Graft and patient survival is best when transplantation is carried out just before starting dialysis treatment. Realistically, only living donor transplantation offers the option of sparing the recipient a long waiting period on dialysis. Although transplantation from living donors is superior to cadaveric kidney transplantation, a small risk remains for the donor. Kidney transplantation and the immunosuppressive therapy are associated with an increased risk for certain types of infection, an increased tumour risk and an increased risk for cardiovascular complications. To address these problems, specific recommendations for patient surveillance have been provided by different transplantation societies.
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Wide-Band KB Optics for Spectro-Microscopy Imaging Applications in the 6–13 keV X-ray Energy Range. ACTA ACUST UNITED AC 2007. [DOI: 10.1063/1.2436314] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Temporospatial coupling of networked synaptic activation of AMPA-type glutamate receptor channels and calcium transients in cultured motoneurons. Neuroscience 2006; 142:1019-29. [PMID: 16949760 DOI: 10.1016/j.neuroscience.2006.07.034] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2005] [Revised: 07/05/2006] [Accepted: 07/11/2006] [Indexed: 11/16/2022]
Abstract
AMPA-type glutamate receptor (GluR) channels provide fast excitatory synaptic transmission in the CNS, but mediate also cytotoxic insults. It could be shown that AMPA-type GluR channel-mediated chronic excitotoxicity leads to an increased intracellular calcium concentration and plays an important role in neurodegenerative diseases like for example amyotrophic lateral sclerosis (ALS). As calcium is an important mediator of various processes in the cell and calcium signals have to be very precise in the temporospatial resolution, excessive intracellular calcium increases can seriously impair cell function. It is still unclear if AMPA-type receptors can directly interact with the intracellular calcium homeostasis or if other mechanisms are involved in this process. The objective of this study was therefore to investigate the calcium homeostasis in rat motoneurons under physiological stimulation of AMPA-type GluR channels using calcium imaging techniques and patch-clamp recordings simultaneously. It was found that spontaneous excitatory postsynaptic currents of cultured motoneurons did not elicit significant intracellular calcium transients. Large intracellular calcium transients occurred only when preceding fast sodium currents were observed. Pharmacological experiments showed that activation of AMPA-type GluR channels during synaptic transmission has a great functional impact on the calcium homeostasis in motoneurons as all kinds of activity was completely blocked by application of the selective kainate- and AMPA-type GluR channel blocker 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). Furthermore we suggest from our experiments that calcium transients of several hundred milliseconds' duration result from release of calcium from the endoplasmic reticulum via activation of ryanodine receptors (calcium-induced calcium release, CICR). Our results help to understand the regulatory function of AMPA-type GluR channels in the intracellular calcium homeostasis which is known to be disturbed in neurodegenerative diseases.
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Abstract
BACKGROUND The long-term reliability of cochlear implants over time is an important issue for patients and cochlear implant teams. The calculation of cumulative survival rates including all hard failures of cochlear implants is suitable to report objectively about cochlear implant reliability. METHODS This is a report of 192 cochlear implants from different manufacturers in adults (n = 58) and children (n = 134). RESULTS The overall cumulative implant survival rate was 91.7% for a period of 11 years. The main reasons for hard failures were design errors of the products and direct or indirect trauma to the cochlea implant site (especially in children) with consecutive breaks of the implant body or electrodes. CONCLUSIONS To improve our knowledge about reliability of cochlear implants more studies on cumulative long time survival of cochlear implants are needed, where functional failures and complications for whatever reason (design, mechanical, electronic, medical) are included. Cochlear implant reliability data should be considered during the choice of an implant for each individual patient.
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Prevalence of measles susceptibility among health care workers in a UK hospital. Does the UK need to introduce a measles policy for its health care workers? Occup Med (Lond) 2003; 53:398-402. [PMID: 14514907 DOI: 10.1093/occmed/kqg077] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES First, to determine the prevalence of measles non-immunity in a group of health care workers (HCW), and secondly, to investigate what pre-employment screening for measles is carried out by NHS occupational health departments. METHODS Two hundred and eighteen HCWs with patient contact on the medical wards at Addenbrooke's hospital provided an oral fluid sample and answered a questionnaire. A postal survey of Association of National Health Occupational Physicians Society (ANHOPS) members was conducted to assess whether UK NHS Trusts identify measles non-immune individuals. RESULTS Of the HCWs tested, 3.3% of were found to be non-immune to measles (both oral fluid and confirmatory serum sample were measles IgG negative). Less than one third of a sample of 80 NHS occupational health departments enquired about measles immunity. CONCLUSION The prevalence of measles non-immune health care workers is low, but with a fall in uptake of MMR immunization and increased likelihood of measles outbreaks, it is important to identify these at-risk individuals. Serum testing is the most reliable method to use. Oral fluid testing and history of measles disease or vaccination are unreliable methods of identifying non-immune individuals. To achieve complete immunity, it is cost-effective to screen and then offer immunization. NHS trusts vary greatly in their measles policies for health care workers.
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Abstract
The aim of our hGH application study with non-competitive athletes was the investigation of selected serum parameters from different processes affected by hGH. Fifteen athletes (age 21-33, mean 24) were treated with 0.06 IU hGH/kg BW per day or placebo (10 hGH, 5 placebo) respectively for 14 days. Blood samples were taken prior to, during and until 10 weeks after treatment. The concentrations of the following markers were determined in relevant serum samples: IGF-I, IGFBP-3, ALS, PIIINP, PINP, osteocalcin, and leptin. The IGF-I concentration increased rapidly within the hGH treatment group and showed significantly higher levels compared to baseline even 3 days after application. The response of the IGFBP-3 to the hGH applications was lower in comparison to IGF-I. The hGH group showed an increasing IGFBP-3 compared to baseline from day 4 till day 15. The response of PIIINP to hGH is clearly delayed compared to the IGF-I axis, but the PIIINP concentration remains on an increased level for a longer period (from day 4 until day 21). The time course and the extent of response varied strongly interindividually. PINP and osteocalcin showed only a small response to hGH applications. These parameters are characterised by a strong scattering of base values compared with the small response. In the hGH treatment group very different leptin concentrations were found at the beginning of the study, but after treatment decreasing leptin levels were observed in all cases. The determination of only one parameter will not be sufficient for detection of hGH abuse. A combination of markers by mathematical methods can be helpful to distinguish between placebo and hGH-treated athletes. By using the suggested discriminant function the data sets of hGH and placebo-treated athletes could be separated without false positive results.
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15. Mainzer Allergie-Workshop 2003. ALLERGO JOURNAL 2003. [DOI: 10.1007/bf03361093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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[A Swiss physician's perspective of public health care in the south of Germany, autumn 1946]. MEDIZIN, GESELLSCHAFT, UND GESCHICHTE : JAHRBUCH DES INSTITUTS FUR GESCHICHTE DER MEDIZIN DER ROBERT BOSCH STIFTUNG 2002; 20:137-77. [PMID: 12322723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
In the autumn of 1946, a committee of Swiss physicians toured southern Germany to examine German measures for air-raid protection and to evaluate the country's wartime public health care. One of the participants, the St. Gallen physician Hans Richard von Fels, complemented the committee's official report with a personal diary of the journey. This document includes von Fels' personal observations of the physical, psychic and political state of the German population, the wartime destruction of the cities, and local public health services. This text is an important historical document, partly because it is one of the few "ego-documents" relating to the public health sector in post-war Germany.
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Abstract
AIMS To investigate the potential exposure to cytotoxic drugs of staff on two oncology wards in a large district, UK hospital under normal working conditions. METHODS Cytotoxic drug exposure was monitored in urine samples, surface wipes, and on disposable gloves by using a number of commonly used marker drugs, namely cyclophosphamide, ifosfamide, methotrexate, and the platino coordinated drugs. Questionnaire data on their work practices, potential exposure, use of protective personal equipment, and relevant training were collected from nursing, domestic, and clerical staff on two oncology wards. RESULTS The majority of staff were female with a mean age of 31 years. Roughly half of the staff studied were specifically trained nurses with an average of 3.5 years experience of administering cytotoxic drugs. No cytotoxic drug preparation or reconstitution was carried out on the wards. Disposable gloves, plastic armlets and aprons, but not eye protection, were invariably worn where there was potential exposure to cytotoxics. No cytotoxic drug was detected in any of the staff's urine samples. Isolated disposable latex gloves from nurses administering drugs showed some contamination, as did some surfaces within the wards' sluice rooms, but not in the ward areas where the drugs were stored and checked prior to administration. CONCLUSIONS The risk management strategies in place, including use of personal protective equipment, staff training, and other organisational measures, have ensured that internal exposure is lower than the detection limits for the current biological monitoring methods. Levels of contamination appear significantly lower than earlier, non-UK published studies where different risk management strategies were in place and, in particular, ward staff may have been involved in some degree of cytotoxic drug reconstitution.
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First observation of meridional focusing of an X-ray beam using diffraction by a crystal with a transverse groove. JOURNAL OF SYNCHROTRON RADIATION 2001; 8:1203-1206. [PMID: 11679773 DOI: 10.1107/s0909049501015163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2001] [Accepted: 09/04/2001] [Indexed: 05/23/2023]
Abstract
The possibility of concentrating a synchrotron X-ray beam using diffraction by a single crystal with a properly designed transverse groove on its surface, suggested earlier, has been studied experimentally. Here, the first experimental demonstration of this effect is reported, performed on beamline BM5 at the ESRF. The experimental result confirms the theoretical model.
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Wet-etched diffractive lenses for hard X-rays. JOURNAL OF SYNCHROTRON RADIATION 2001; 8:1054-1055. [PMID: 11486414 DOI: 10.1107/s0909049501002746] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2001] [Accepted: 02/08/2001] [Indexed: 05/23/2023]
Abstract
A method for the fabrication of linear transmission Fresnel zone plates for X-rays in the 8-15 keV photon energy range is presented. The diffractive elements are generated by electron-beam lithography and chemical wet etching of (110)-oriented silicon membrane substrates. Diffractive structures with aspect ratios of more than 30 for 300 nm-wide structures were obtained. The diffraction efficiency of such a lens was measured for 13.3 keV radiation to be 20%.
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Abstract
BACKGROUND AND OBJECTIVE Biofeedback is known as a possibility to control physiologic processes like body temperature or heart frequency. Neurofeedback is a form of biofeedback linked to aspects of the electrical activity of the brain such as frequency, location or amplitude of specific EEG activity. It has been successfully used in patients with closed head injury, hyperactivity disorder or epilepsy. PATIENTS/METHODS In this study 40 patients with tinnitus were treated with neurofeedback.They trained to upregulate the amplitude of their alpha-activity and downregulate the amplitude of beta-activity during muscle relaxation and acoustic orientation on sounds or music in order to suppress their tinnitus. RESULTS After 15 sessions of training 24 patients with a duration of their tinnitus for an average of 1 year showed significant increase of alpha-amplitudes while 16 patients with duration of their tinnitus on an average of 7 years showed a decrease of beta-amplitudes without any change in alpha-activity. After the training all patients had a significant reduction of the score in the tin nitusquestionaire of Gobel and Hiller. In a control-group of 15 persons without tinnitus we didn't see any changes of alpha- or beta-amplitudes during the same training. CONCLUSIONS In conclusion neurofeedback is a new therapy for patients with tinnitus. Patients get the possibility of selfcontrol and therefore of influence on their disease.
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Nosocomial transmission of measles to healthcare workers. Time for a national screening and immunization policy for NHS staff? J Hosp Infect 2000; 44:154-5. [PMID: 10662570 DOI: 10.1053/jhin.1999.0667] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Formal cancer support groups are thought to assist women to adapt to the physiological and psychosocial sequelae of breast cancer. To shed some light on this untested clinical assumption, this Roy Adaptation Model of Nursing-based study was designed to explore women's own reports about their adaptation to breast cancer and their participation in support groups. This article reports the results of the quantitative content analysis of structured telephone interviews with 70 women who participated in group social support and education for breast cancer. Almost three-quarters of the women expressed a positive change in attitude towards breast cancer, and all regarded participation in the groups as positive. A majority reported adaptive physiological, self-concept, role function, and interdependence mode effects of breast cancer and group participation. Additional research is needed to show how different types of cancer support groups, including social support and education groups and psychotherapy groups, contribute to women's responses. Research is also needed to separate the effects of group social support and education from other sources of social support that may have contributed to the women's responses, and to further explore feelings of normalization expressed by some women.
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High-frequency X-ray beam chopper based on diffraction by surface acoustic waves. JOURNAL OF SYNCHROTRON RADIATION 1998; 5:1357-62. [PMID: 16687848 DOI: 10.1107/s0909049598008437] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/1998] [Accepted: 06/16/1998] [Indexed: 05/09/2023]
Abstract
The diffraction of an X-ray beam on an ultrasonic wave propagating at the surface of a crystal gives rise to diffraction satellites whose temporal structure is correlated to that of the ultrasonic wave. By matching the temporal structure of the surface acoustic wave with the filling mode of the storage ring, it is possible to select or reject the incident X-ray pulses. A few examples of the performance of this MHz-range chopper for various filling modes are presented.
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Design optimization of a flexural hinge-based bender for X-ray optics. JOURNAL OF SYNCHROTRON RADIATION 1998; 5:804-807. [PMID: 15263659 DOI: 10.1107/s0909049597015288] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/1997] [Accepted: 11/03/1997] [Indexed: 05/24/2023]
Abstract
This paper presents a parameter study and design optimization of a flexural hinge-based bender by use of finite-element modelling and analytical formulation. The relationship between the mirror shape and the driving forces, the so-called bender driving equation, is established. Various parameters are investigated: the material properties, the geometrical parameters, the stress and deformation of the mirror and flexural hinge, the residual slope error of the mirror, and the resolution required for the actuators. Analysis results have been compared with test results for a prototype bender and a silicon mirror (170 x 40 x 10 mm). Both analysis and test results confirm the microradian accuracy of the bent mirror. Finally, a bender design for short-bending-radius applications is also presented.
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Focusing Optics for High-Energy X-ray Diffraction. JOURNAL OF SYNCHROTRON RADIATION 1998; 5:226-231. [PMID: 15263483 DOI: 10.1107/s0909049598001393] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/1997] [Accepted: 01/20/1998] [Indexed: 05/24/2023]
Abstract
Novel focusing optical devices have been developed for synchrotron radiation in the energy range 40-100 keV. Firstly, a narrow-band-pass focusing energy-tuneable fixed-exit monochromator was constructed by combining meridionally bent Laue and Bragg crystals. Dispersion compensation was applied to retain the high momentum resolution despite the beam divergence caused by the focusing. Next, microfocusing was achieved by a bent multilayer arranged behind the crystal monochromator and alternatively by a bent Laue crystal. A 1.2 micro m-high line focus was obtained at 90 keV. The properties of the different set-ups are described and potential applications are discussed. First experiments were performed, investigating with high spatial resolution the residual strain gradients in layered polycrystalline materials. The results underline that focused high-energy synchrotron radiation can provide unique information on the mesoscopic scale to the materials scientist, complementary to existing techniques based on conventional X-ray sources, neutron scattering or electron microscopy.
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40
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X-ray magnetic reflectometry using circularly polarized radiation. JOURNAL OF SYNCHROTRON RADIATION 1998; 5:998-1000. [PMID: 15263724 DOI: 10.1107/s0909049597016099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/1997] [Accepted: 11/10/1997] [Indexed: 05/24/2023]
Abstract
Magnetic reflectometry experiments have been performed in the X-ray range at the L(2,3) edges of rhodium. What makes these experiments original is the insertion of a very compact double-bounce reflectometer upstream of the monochromator. This configuration makes full use of the high polarization rate of the helical undulator source. This advantage is reflected in the high quality of the data obtained after only a few accumulations. It is also shown that, by properly selecting the angle of incidence, one may obtain experimental differential X-ray reflectivity spectra dominated either by the dispersion or the absorption terms.
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elF4G and its proteolytic cleavage products: effect on initiation of protein synthesis from capped, uncapped, and IRES-containing mRNAs. RNA (NEW YORK, N.Y.) 1997; 3:186-196. [PMID: 9042945 PMCID: PMC1369472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Rhinovirus 2A and foot-and-mouth disease virus Lb proteinases stimulate the translation of uncapped messages and those carrying the rhinovirus and enterovirus Internal Ribosome Entry Segments (IRESes) by a mechanism involving the cleavage of host cell proteins. Here, we investigate this mechanism using an artificial dicistronic RNA containing the human rhinovirus IRES as intercistronic spacer. Because both proteinases cleave eukaryotic initiation factor 4G (eIF4G), we examined whether the cleavage products of eIF4G could stimulate uncapped or IRES-driven translation. Addition of intact eIF4F to translation extracts inhibited IRES-driven translation and reduced the translation stimulation observed in reactions pre-treated with Lb proteinase. Prolonged incubation of translation extracts with Lb proteinase removed all endogenous eIF4G and a substantial amount of the primary C- and N-terminal cleavage products. The translation of all mRNAs was reduced in such extracts. Capped mRNA translation was rescued by the addition of intact eIF4F. In contrast, addition of pre-cleaved eIF4F stimulated translation of uncapped or IRES-bearing messages to the levels seen upon proteinase addition. Furthermore, fractions containing the C-terminal, but not N-terminal, cleavage product of eIF4G stimulated translation moderately. These results demonstrate that the Lb and 2A proteinases stimulate translation of uncapped RNAs and those carrying IRESes by the production of cleavage products of eIF4G that enhance translation and by the removal of intact eIF4G that interferes with this stimulation.
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Molecular characterization of a tissue-polypeptide-specific-antigen epitope and its relationship to human cytokeratin 18. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 241:309-14. [PMID: 8917424 DOI: 10.1111/j.1432-1033.1996.00309.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Tissue-polypeptide-specific antigen (TPS) from the human colon adenocarcinoma cell line WiDr was purified using the monoclonal antibody M3 as a probe. Upon SDS/polyacrylamide gradient gel electrophoresis, several TPS-positive bands were detected (corresponding to 13 kDa, 22 kDa and a doublet at 42 kDa). The 13-kDa moiety was purified about 30,000-fold by a 5-step protocol. The electro-phoretically homogeneous component was obtained in a 7% yield of the total TPS activity of the crude extract. N-terminal sequence analysis showed the presence of an N-terminally truncated molecule and identified the 13-kDa TPS component as a fragment of human cytokeratin 18, with a major from starting at position 284 of the parent molecule. Laser-desorption mass spectrometry showed the presence of one major component with a molecular mass corresponding to a C-terminal end close to position 396 (which gives 12776 Da for the form with non-truncated N-terminus). The M3 antibody was also used to screen a human prostate cDNA lambda gt11 library. Four identical phage clones were detected, each producing a fusion protein with beta-galactosidase and the M3-positive component. PCR amplification showed the presence of an approximately 1200-bp insert, and sequence analysis revealed it to contain a 996-nucleotide fragment corresponding to residues 103-429 of human cytokeratin 18 (plus a non-coding human desmin artifact fragment). Smaller fragments, engineered by PCR and expressed as fusion proteins using the pET3xc vector in Escherichia coli, showed that the M3 epitope is localized to cytokeratin 18, residues 322-340. Two other TPS-active monoclonal antibodies were localized to cytokeratin 18 with similar techniques, ascribing an epitope (to M21) to residues 414-429 and another (to M24) to residues 139-297. Combined, the results demonstrate that TPS reactivity is derived from specific epitopes of human cytokeratin 18.
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Immunomodulation in experimental and clinical nephrology using chimeric proteins. Kidney Blood Press Res 1996; 19:201-4. [PMID: 8887261 DOI: 10.1159/000174074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The objective of immunosuppressive therapy in nephrology is to prevent autoimmune diseases and to suppress kidney allograft rejections while sparing other effects. Increased clarification of the underlying immune mechanism has made specific immunodulation possible using chimeric proteins in which the variable domains of an immunoglobulin are replaced by extracellular domains of cell surface molecules or cytokines. The immunosuppressive effects of fusion proteins such as CTLA-4 IgG, CD40 IgG, interleukin (IL)-10 IgG, IL-2 IgG or tumor necrosis factor (TNF)-receptor IgG have been proven in various animal models. Moreover, the application of TNF-receptor IgG successfully limited the OKT3-induced cytokine release syndrome in kidney graft recipients. It seems likely that recombinant proteins with increasingly effective suppression of specific elements of the immune response will become an essential element in clinical protocols.
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HIV gp120-specific cell-mediated immune responses in mice after oral immunization with recombinant Salmonella. JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES AND HUMAN RETROVIROLOGY : OFFICIAL PUBLICATION OF THE INTERNATIONAL RETROVIROLOGY ASSOCIATION 1995; 10:489-495. [PMID: 8548327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Salmonella is of great interest as a potential human immunodeficiency virus vaccine vector because of its ability to elicit potent mucosal and systemic immune responses when administered orally. To determine whether such a vaccine could elicit an immune response in mice, plasmids expressing HIV gp120-LAI were introduced into attenuated S. typhimurium. Three serial doses of 10(10) recombinant organisms were administered orally to BALB/c mice at 2-week intervals. Immunized mice but not control mice demonstrated proliferative T cell responses to gp120-LAI, comparable in magnitude to the proliferative responses to Salmonella antigens. Immunized mice had detectable serum and intestinal Salmonella-specific IgA and serum Salmonella-specific IgG. However, no gp120-specific antibody was detected in either serum or intestinal washes. These results indicate that live recombinant Salmonella-based vaccine constructs can induce HIV-specific cellular immune responses in vivo.
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Picornavirus 2A proteinase-mediated stimulation of internal initiation of translation is dependent on enzymatic activity and the cleavage products of cellular proteins. Virology 1995; 213:549-57. [PMID: 7491779 DOI: 10.1016/s0042-6822(95)90001-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Poliovirus and human rhinovirus 2A proteinases are known to stimulate translation initiation on the cognate viral Internal Ribosome Entry Segments (IRESes). The molecular mechanism of this translational transactivation was investigated in vitro using dicistronic mRNAs containing picornaviral IRESes as the intercistronic spacer and purified human rhinovirus type 2 and coxsackievirus B4 2A proteinases. The stimulation achieved on the HRV2 IRES in the presence of the cognate 2A proteinase at 1 microgram/ml was twofold; the maximum stimulation at 100 micrograms/ml was fivefold. The IRESes and proteinases from rhino- and enteroviruses were interchangeable; however, stimulation of translation initiation on a cardiovirus IRES by these proteinases was minimal. Studies using an inhibitor or a mutant 2A proteinase demonstrated that translation stimulation requires 2A-mediated enzymatic conversion of some cellular component(s). The HRV2 2A proteinase also stimulated translation initiation on full-length viral RNA, suggesting that 2A proteinase-mediated stimulation of IRES-driven translation has a physiological role.
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Foot-and-mouth disease virus Lb proteinase can stimulate rhinovirus and enterovirus IRES-driven translation and cleave several proteins of cellular and viral origin. J Virol 1995; 69:3465-74. [PMID: 7745693 PMCID: PMC189059 DOI: 10.1128/jvi.69.6.3465-3474.1995] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Rhinovirus and enterovirus 2A proteinases stimulate translation initiation driven from the cognate internal ribosome entry segment (IRES) (S. J. Hambidge and P. Sarnow, Proc. Natl. Acad. Sci. USA 89:10272-10276, 1992; H.-D. Liebig, E. Ziegler, R. Yan, K. Hartmuth, H. Klump, H. Kowalski, D. Blaas, W. Sommergruber, L. Frasel, B. Lamphear, R. Rhoads, E. Kuechler, and T. Skern, Biochemistry 32:7581-7588, 1993). Given the functional similarities between the foot-and-mouth disease virus (FMDV) L proteinase and these 2A proteinases (autocatalytic excision from the nascent viral polyprotein and cleavage of eIF-4 gamma), we investigated whether the FMDV L proteinase would also be able to stimulate translation initiation. We found that purified recombinant FMDV Lb proteinase could stimulate in vitro translation driven from a rhinovirus or enterovirus IRES by 5- to 10-fold. In contrast, stimulation of translation initiation on a cardiovirus IRES by this proteinase was minimal, and stimulation of translation driven from the cognate FMDV IRES could not be evidenced. Studies using an inhibitor or a mutant Lb proteinase indicated that stimulation of IRES-driven translation is mediated via proteolysis of some cellular component(s). Our studies also demonstrated that the Lb proteinase is capable of stimulating initiation of translation on an uncapped cellular message. Unexpectedly, and in contrast to the 2A proteinases, the Lb proteinase specifically cleaved the products of the two reporter genes used in this study: Xenopus laevis cyclin B2 and influenza virus NS. Therefore, we also set out to investigate the requirements for substrate recognition by the Lb proteinase. Purified recombinant Lb proteinase recognized at least one mengovirus polypeptide and specifically cleaved human cyclin A and poliovirus replicase-related polypeptides. In the latter case, the site(s) of cleavage was located within the N-terminal part of polypeptide 3D. Sequence comparisons revealed no significant primary sequence similarities between the target proteins and the two sites already known to be recognized by the FMDV L proteinase.
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A Double Multilayer Monochromator at an ESRF Undulator for Microbeam Experiments. JOURNAL OF SYNCHROTRON RADIATION 1995; 2:124-31. [PMID: 16714803 DOI: 10.1107/s0909049595001592] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A water-cooled double W/Si-multilayer monochromator has been operated at an ESRF low-beta undulator beam. For a fixed distance of the two multilayers the first-order Bragg reflection was at ~8 keV. The peak power density of the beam at the exit of the multilayers was ~1 W mm(-2) and the flux density of the first order after a 10 mum collimator was 4 x 10(5) photons s(-1) mum(-2) mA(-1.) The performance of the beam in microbeam diffraction has been tested on a 20 mum W wire. The observed pseudo-Laue pattern is discussed with respect to the multilayer spectrum.
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Foot-and-mouth disease virus leader proteinase: purification of the Lb form and determination of its cleavage site on eIF-4 gamma. J Virol 1994; 68:5677-84. [PMID: 8057448 PMCID: PMC236969 DOI: 10.1128/jvi.68.9.5677-5684.1994] [Citation(s) in RCA: 163] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Many picornaviruses cause a dramatic decrease in the translation of cellular mRNAs in the infected cell, without affecting the translation of their own RNA. Specific proteolysis of protein synthesis initiation factor eIF-4 gamma occurs during infection with rhinoviruses, enteroviruses, and aphthoviruses, apparently leading to an inability of the ribosomes to bind capped mRNAs. Cleavage of eIF-4 gamma in human rhinoviruses and enteroviruses is carried out by the viral 2A proteinase; in aphthoviruses (i.e., foot-and-mouth disease viruses), the leader proteinase is responsible for this reaction. We describe here the purification to homogeneity of the Lb form of the leader proteinase expressed in Escherichia coli. The primary cleavage products of eIF-4 gamma obtained in vitro with purified leader or 2A proteinase are electrophoretically indistinguishable from those found during infection in vivo. However, additional proteolysis products of eIF-4 gamma are observed with the leader proteinase and the human rhinovirus type 2 2A proteinase in vitro. The cleavage site of the leader proteinase in eIF-4 gamma from rabbit reticulocyte was determined by sequencing the purified C-terminal cleavage product by automated Edman degradation. The cleavage site is between Gly-479 and Arg-480 and thus differs from that of rhinovirus and enterovirus 2A proteinases, which cleave between Arg-486 and Gly-487.
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Purification of two picornaviral 2A proteinases: interaction with eIF-4 gamma and influence on in vitro translation. Biochemistry 1993; 32:7581-8. [PMID: 8338854 DOI: 10.1021/bi00080a033] [Citation(s) in RCA: 161] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A mammalian cell infected with a human rhinovirus or enterovirus has a much reduced capability to translate capped mRNAs (the host cell shutoff), while still allowing translation of uncapped viral RNA. Biochemical and genetic evidence suggests that the viral proteinase 2A induces cleavage of the eukaryotic initiation factor (eIF) 4 gamma (also known as p220) component of eIF-4 (formerly called eIF-4F). However, neither the mechanism underlying the specific proteolysis of eIF-4 gamma nor the influence of this cleavage on the translation of capped mRNAs has been clarified. Such studies have been hampered by a lack of large quantities of a purified 2A proteinase. Therefore, the mature proteinases 2A of human rhinovirus 2 and coxsackievirus B4 were expressed in soluble form in Escherichia coli. A four-step purification protocol was developed; 1 mg of highly purified 2A proteinase per gram wet weight of E. coli was obtained. Both enzymes cleaved directly eIF-4 gamma as part of the purified eIF-4 complex. Addition of HRV2 2A proteinase to HeLa cell cytoplasmic translation extracts resulted in eIF-4 gamma cleavage and drastically reduced the translation of capped mRNA; addition of purified eIF-4 restored translation to the initial level. However, translation of a reporter gene driven by the 5'-untranslated region of human rhinovirus 2 was translated 2-3-fold more efficiently in the presence of HRV2 2A proteinase.
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50
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A multilayer analyser suitable for linear detection of anomalous small-angle X-ray scattering. J Appl Crystallogr 1992. [DOI: 10.1107/s0021889892007064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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