7 results on '"Drewes B"'
Search Results
2. Variation in prenatal surveillance and management of anti-SSA/Ro autoantibody positive pregnancies.
- Author
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Howley LW, Eyerly-Webb SA, Killen SAS, Paul E, Krishnan A, Gropler MRF, Drewes B, Dion E, Lund A, Buyon JP, and Cuneo BF
- Subjects
- Child, Female, Pregnancy, Humans, Autoantibodies, Fetal Heart, Health Facilities, Prenatal Care, Vitamins, Atrioventricular Block
- Abstract
Objective: To describe international surveillance and treatment strategies for managing anti-SSA/Ro autoantibody positive pregnancies., Study Design: An electronic REDCap questionnaire was distributed to Fetal Heart Society and North American Fetal Therapy Network members which queried institution-based risk stratification, surveillance methods/frequency, conduction abnormality treatments, and postnatal anti-SSA/Ro pregnancy assessment., Results: 101 responses from 59 centers (59% US, 17% international) were collected. Most (79%) do not risk stratify pregnancies by anti-SSA/Ro titer; those that do use varied cutoff values. Many pregnant rheumatology patients are monitored for cardiac abnormalities regardless of maternal anti-SSA/Ro status. Surveillance strategies were based on maternal factors (anti-SSA/Ro status 85%, titer 25%, prior affected child 79%) and monitoring durations varied. Most respondents treat 2° and 3° fetal atrioventricular block, commonly with dexamethasone and/or IVIG., Conclusions: Wide variation exists in current fetal cardiac surveillance and treatment for anti-SSA/Ro autoantibody positive pregnancies, highlighting the need for evidence-based protocols to optimize care.
- Published
- 2024
- Full Text
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3. Observed protection against SARS-CoV-2 reinfection following a primary infection: A Danish cohort study among unvaccinated using two years of nationwide PCR-test data.
- Author
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Michlmayr D, Hansen CH, Gubbels SM, Valentiner-Branth P, Bager P, Obel N, Drewes B, Møller CH, Møller FT, Legarth R, Mølbak K, and Ethelberg S
- Abstract
Background: The level of protection after a SARS-CoV-2 infection against reinfection and COVID-19 disease remains important with much of the world still unvaccinated., Methods: Analysing nationwide, individually referable, Danish register data including RT-PCR-test results, we conducted a cohort study using Cox regression to compare SARS-CoV-2 infection rates before and after a primary infection among still unvaccinated individuals, adjusting for sex, age, comorbidity and residency region. Estimates of protection against infection were calculated as 1 minus the hazard ratio. Estimates of protection against symptomatic infections and infections leading to hospitalisation were also calculated. The prevalence of infections classified as symptomatic or asymptomatic was compared for primary infections and reinfections. The study also assessed protection against each of the main viral variants after a primary infection with an earlier variant by restricting follow-up time to distinct, mutually exclusive periods during which each variant dominated., Findings: Until 1 July 2021 the estimated protection against reinfection was 83.4% (95%CI: 82.2-84.6%); but lower for the 65+ year-olds (72.2%; 95%CI: 53.2-81.0%). Moderately higher estimates were found for protection against symptomatic disease, 88.3% overall (95%CI: 85.9-90.3%). First-time cases who reported no symptoms were more likely to experience a reinfection (odds ratio: 1.48; 95%CI: 1.35-1.62). By autumn 2021, when infections were almost exclusively caused by the Delta variant, the estimated protection following a recent first infection was 91.3% (95%CI: 89.7-92.7%) compared to 71.4% (95%CI: 66.9-75.3%) after a first infection over a year earlier. With Omicron, a first infection with an earlier variant in the past 3-6 months gave an estimated 51.0% (95%CI: 50.1-52.0%) protection, whereas a first infection longer than 12 months earlier provided only 19.0% (95%CI: 17.2-20.5%) protection. Protection by an earlier variant-infection against hospitalisation due to a new infection was estimated at: 86.6% (95%CI: 46.3-96.7%) for Alpha, 97.2% (95%CI: 89.0-99.3%) for Delta, and 69.8% (95%CI: 51.5-81.2%) for the Omicron variant., Interpretation: SARS-CoV-2 infection offered a high level of sustained protection against reinfection, comparable with that offered by vaccines, but decreased with the introduction of new main virus variants; dramatically so when Omicron appeared. Protection was lower among the elderly but appeared more pronounced following symptomatic compared to asymptomatic infections. The level of estimated protection against serious disease was somewhat higher than that against infection and possibly longer lasting. Decreases in protection against reinfection, seemed primarily to be driven by viral evolution., Funding: None., Competing Interests: All authors declare no competing interests., (© 2022 The Authors.)
- Published
- 2022
- Full Text
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4. Preparation of a First 18 F-Labeled Agonist for M 1 Muscarinic Acetylcholine Receptors.
- Author
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Zlatopolskiy BD, Neumaier F, Rüngeler T, Drewes B, Kolks N, and Neumaier B
- Subjects
- Chromatography, High Pressure Liquid, Glycols chemistry, Halogenation, Ligands, Muscarinic Agonists chemistry, Radiopharmaceuticals chemistry, Reference Standards, Fluorine Radioisotopes chemistry, Muscarinic Agonists chemical synthesis, Receptors, Muscarinic metabolism
- Abstract
M
1 muscarinic acetylcholine receptors (mAChRs) are abundant in postsynaptic nerve terminals of all forebrain regions and have been implicated in the cognitive decline associated with Alzheimer's disease and other CNS pathologies. Consequently, major efforts have been spent in the development of subtype-selective positron emission tomography (PET) tracers for mAChRs resulting in the development of several11 C-labeled probes. However, protocols for the preparation of18 F-labeled mAChR-ligands have not been published so far. Here, we describe a straightforward procedure for the preparation of an18 F-labeled M1 mAChR agonist and its corresponding pinacol boronate radiolabeling precursor and the non-radioactive reference compound. The target compounds were prepared from commercially available aryl fluorides and Boc protected 4-aminopiperidine using a convergent reaction protocol. The radiolabeling precursor was prepared by a modification of the Miyaura reaction and labeled via the alcohol-enhanced Cu-mediated radiofluorination. The developed procedure afforded the radiotracer in a non-decay-corrected radiochemical yield of 17 ± 3% ( n = 3) and in excellent radiochemical purity (>99%) on a preparative scale. Taken together, we developed a straightforward protocol for the preparation of an18 F-labeled M1 mAChR agonist that is amenable for automation and thus provides an important step towards the routine production of a18 F-labeled M1 selective PET tracer for experimental and diagnostic applications.- Published
- 2020
- Full Text
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5. Mucosubstances in the porcine gastrointestinal tract: Fixation, staining and quantification.
- Author
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Rieger J, Drewes B, Hünigen H, and Plendl J
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- Animals, Cytoplasmic Vesicles chemistry, Gastrointestinal Tract cytology, Goblet Cells chemistry, Goblet Cells cytology, Mucins chemistry, Mucins classification, Swine, Gastrointestinal Tract chemistry, Histocytochemistry methods, Mucins analysis, Staining and Labeling methods
- Abstract
Mucins are of great interest in intestinal research and histochemical methods are often employed to identify them. Since it is in the nature of mucins that they are "hard to hold onto" once they come into contact with water, a frequently used medium in histochemistry, there are a number of challenges that may decrease diagnostic accuracy. As the outcome of methods published for microscopic detection of mucosubstances proved to be unsatisfactory in our hands, the aim was the establishment of a reliable and reproducible protocol. Tissue samples were available from pig feeding experiments. In the present study, we focus on a fixation / staining procedure without making comparisons between differently fed pigs. Several fixation and staining procedures were evaluated for their use in semiautomatic quantification and quality assessment of different mucus fractions simultaneous on one tissue section. Cryostat sectioning, subsequent fixation steps with heat, ethanol and modified Bouin's solution, followed by triple staining with high iron diamine, alcian blue and periodic acid-Schiff turned out to be the best method to identify sulfomucin, sialomucin and neutral mucin simultaneous on one tissue section. This methodology resulted in very good morphology of goblet cells with intact mucin containing vesicles within the cells, which was comparable to ultrastructural electron microscopical observations. Semiautomatic quantification of different mucins was possible. In conclusion, reliable mucus quantification and assessment of mucus quality requires strictly tested procedures. According to our experience, the most important aim after cryosectioning is fast fixation of the mucosubstances, which requires a combination of different fixation steps.
- Published
- 2019
- Full Text
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6. Comparison of different histological protocols for the preservation and quantification of the intestinal mucus layer in pigs.
- Author
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Röhe I, Hüttner FJ, Plendl J, Drewes B, and Zentek J
- Subjects
- Animals, Goblet Cells cytology, Goblet Cells ultrastructure, Histological Techniques classification, Mucus chemistry, Preservation, Biological methods, Swine, Histological Techniques methods, Histological Techniques trends, Intestinal Mucosa ultrastructure, Intestines ultrastructure
- Abstract
The histological characterization of the intestinal mucus layer is important for many scientific experiments investigating the interaction between intestinal microbiota, mucosal immune response and intestinal mucus production. The aim of this study was to examine and compare different fixation protocols for displaying and quantifying the intestinal mucus layer in piglets and to test which histomorphological parameters may correlate with the determined mucus layer thickness. Jejunal and colonal tissue samples of weaned piglets (n=10) were either frozen in liquid nitrogen or chemically fixed using methacarn solution. The frozen tissue samples were cryosectioned and subsequently postfixed using three different postfixatives: paraformaldehyde vapor, neutrally buffered formalin solution and ethanol solution. After dehydration, methacarn fixed tissues were embedded in paraffin wax. Both sections of cryopreserved and methacarn fixed tissue samples were stained with Alcian blue (AB)-PAS followed by the microscopically determination of the mucus layer thickness. Different pH values of the Alcian Blue staining solution and two mucus layer thickness measuring methods were compared. In addition, various histomorphological parameters of methacarn fixed tissue samples were evaluated including the number of goblet cells and the mucin staining area. Cryopreservation in combination with chemical postfixation led to mucus preservation in the colon of piglets allowing mucus thickness measurements. Mucus could be only partly preserved in cryosections of the jejunum impeding any quantitative description of the mucus layer thickness. The application of different postfixations, varying pH values of the AB solution and different mucus layer measuring methods led to comparable results regarding the mucus layer thickness. Methacarn fixation proved to be unsuitable for mucus depiction as only mucus patches were found in the jejunum or a detachment of the mucus layer from the epithelium was observed in the colon. Correlation analyses revealed that the proportion of the mucin staining area per crypt area (relative mucin staining) measured in methacarn fixed tissue samples corresponded to the colonal mucus layer thickness determined in cryopreserved tissue samples. In conclusion, the results showed that cryopreservation using liquid nitrogen followed by chemical postfixation and AB-PAS staining led to a reliable mucus preservation allowing a mucus thickness determination in the colon of pigs. Moreover, the detected relative mucin staining area may serve as a suitable histomorphological parameter for the assessment of the intestinal mucus layer thickness. The findings obtained in this study can be used for the implementation of an improved standard for the histological description of the mucus layer in the colon of pigs.
- Published
- 2018
- Full Text
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7. (2R,3R,4S,5R)-2-(4-Amino-5-iodo-7H-pyrrolo-[2,3-d]pyrimidin-7-yl)-5-methyl-tetra-hydro-furan-3,4-diol.
- Author
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Flörke U and Drewes B
- Abstract
The mol-ecular structure of the title compound, C11H13IN4O3, shows a ribo-furanos-yl-pyrrolo O-C-N-C torsion angle of 59.1 (3)°, with the central C-N bond length being 1.446 (3) Å. The C-I bond length is 2.072 (2) Å. The amino group is coplanar with the attached aromatic ring [C-N-C-N torsion angle = -178.8 (2)°] and forms an intra-molecular N-H⋯I hydrogen bond. In the crystal, O-H⋯N and N-H⋯O hydrogen bonds link the mol-ecules into puckered layers parallel to (001). These layers are bound to each other by secondary I⋯O inter-actions [3.2250 (17) Å], forming a three-dimensional framework.
- Published
- 2013
- Full Text
- View/download PDF
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