31 results on '"Patzelt C"'
Search Results
2. Inhibition by ethanol of excitatory amino acid receptors and nicotinic acetylcholine receptors at rat locus coeruleus neurons
- Author
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Fröhlich, R., Patzelt, C., and Illes, P.
- Published
- 1994
- Full Text
- View/download PDF
3. Der präventive Hausbesuch als zugehende Präventionsmaßnahme im Alter – Effektivität und Kosteneffektivität von Zugangswegen
- Author
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Patzelt, C, Deitermann, B, Heim, S, Lupp, K, Stahmeyer, J, Krauth, C, Theile, G, Hummers-Pradier, E, Walter, U, University of Zurich, and Patzelt, C
- Subjects
610 Medicine & health ,2739 Public Health, Environmental and Occupational Health ,10044 Clinic for Radiation Oncology - Published
- 2015
4. Antibodies directed against the pancreatic islet cell plasma membrane detection and specificity
- Author
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Lernmark, Å., Kanatsuna, T., Patzelt, C., Diakoumis, K., Carroll, R., Rubenstein, A. H., and Steiner, D. F.
- Published
- 1980
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5. Differential inhibitory action of cationic amino acids on protein synthesis in pancreatic rat islets
- Author
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Patzelt, C.
- Published
- 1988
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6. The effect of glucagon on the state of lysosomal enzymes in isolated perfused rat liver
- Author
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Guder, W., Fröhlich, J., Patzelt, C., and Wieland, O.
- Published
- 1970
- Full Text
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7. The elicitation of patient and physician preferences for calculating consumer-based composite measures on hospital report cards: results of two discrete choice experiments.
- Author
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Emmert M, Rohrbacher S, Meier F, Heppe L, Drach C, Schindler A, Sander U, Patzelt C, Frömke C, Schöffski O, and Lauerer M
- Subjects
- Humans, Middle Aged, Male, Female, Aged, Adult, Hospitals, Quality Indicators, Health Care, Patient Preference, Choice Behavior, Physicians psychology, Physicians statistics & numerical data
- Abstract
Purpose: The calculation of aggregated composite measures is a widely used strategy to reduce the amount of data on hospital report cards. Therefore, this study aims to elicit and compare preferences of both patients as well as referring physicians regarding publicly available hospital quality information METHODS: Based on systematic literature reviews as well as qualitative analysis, two discrete choice experiments (DCEs) were applied to elicit patients' and referring physicians' preferences. The DCEs were conducted using a fractional factorial design. Statistical data analysis was performed using multinomial logit models RESULTS: Apart from five identical attributes, one specific attribute was identified for each study group, respectively. Overall, 322 patients (mean age 68.99) and 187 referring physicians (mean age 53.60) were included. Our models displayed significant coefficients for all attributes (p < 0.001 each). Among patients, "Postoperative complication rate" (20.6%; level range of 1.164) was rated highest, followed by "Mobility at hospital discharge" (19.9%; level range of 1.127), and ''The number of cases treated" (18.5%; level range of 1.045). In contrast, referring physicians valued most the ''One-year revision surgery rate'' (30.4%; level range of 1.989), followed by "The number of cases treated" (21.0%; level range of 1.372), and "Postoperative complication rate" (17.2%; level range of 1.123) CONCLUSION: We determined considerable differences between both study groups when calculating the relative value of publicly available hospital quality information. This may have an impact when calculating aggregated composite measures based on consumer-based weighting., (© 2023. The Author(s).)
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- 2024
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8. Oxidative Stress Reaction to Hypobaric-Hyperoxic Civilian Flight Conditions.
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Netzer NC, Jaekel H, Popp R, Gostner JM, Decker M, Eisendle F, Turner R, Netzer P, Patzelt C, Steurer C, Cavalli M, Forstner F, and Pramsohler S
- Subjects
- Humans, Male, Female, Adult, COVID-19, Hyperoxia blood, Aircraft, Hyperbaric Oxygenation, Oxidative Stress, Altitude, Oxygen metabolism
- Abstract
Background: In military flight operations, during flights, fighter pilots constantly work under hyperoxic breathing conditions with supplemental oxygen in varying hypobaric environments. These conditions are suspected to cause oxidative stress to neuronal organ tissues. For civilian flight operations, the Federal Aviation Administration (FAA) also recommends supplemental oxygen for flying under hypobaric conditions equivalent to higher than 3048 m altitude, and has made it mandatory for conditions equivalent to more than 3657 m altitude., Aim: We hypothesized that hypobaric-hyperoxic civilian commercial and private flight conditions with supplemental oxygen in a flight simulation in a hypobaric chamber at 2500 m and 4500 m equivalent altitude would cause significant oxidative stress in healthy individuals., Methods: Twelve healthy, COVID-19-vaccinated (third portion of vaccination 15 months before study onset) subjects (six male, six female, mean age 35.7 years) from a larger cohort were selected to perform a 3 h flight simulation in a hypobaric chamber with increasing supplemental oxygen levels (35%, 50%, 60%, and 100% fraction of inspired oxygen, FiO
2 , via venturi valve-equipped face mask), switching back and forth between simulated altitudes of 2500 m and 4500 m. Arterial blood pressure and oxygen saturation were constantly measured via radial catheter and blood samples for blood gases taken from the catheter at each altitude and oxygen level. Additional blood samples from the arterial catheter at baseline and 60% oxygen at both altitudes were centrifuged inside the chamber and the serum was frozen instantly at -21 °C for later analysis of the oxidative stress markers malondialdehyde low-density lipoprotein (M-LDL) and glutathione-peroxidase 1 (GPX1) via the ELISA test., Results: Eleven subjects finished the study without adverse events. Whereas the partial pressure of oxygen (PO2 ) levels increased in the mean with increasing oxygen levels from baseline 96.2 mm mercury (mmHg) to 160.9 mmHg at 2500 m altitude and 60% FiO2 and 113.2 mmHg at 4500 m altitude and 60% FiO2 , there was no significant increase in both oxidative markers from baseline to 60% FiO2 at these simulated altitudes. Some individuals had a slight increase, whereas some showed no increase at all or even a slight decrease. A moderate correlation (Pearson correlation coefficient 0.55) existed between subject age and glutathione peroxidase levels at 60% FiO2 at 4500 m altitude., Conclusion: Supplemental oxygen of 60% FiO2 in a flight simulation, compared to flying in cabin pressure levels equivalent to 2500 m-4500 m altitude, does not lead to a significant increase or decrease in the oxidative stress markers M-LDL and GPX1 in the serum of arterial blood.- Published
- 2024
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9. Referring physicians' intention to use hospital report cards for hospital referral purposes in the presence or absence of patient-reported outcomes: a randomized trial.
- Author
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Emmert M, Schindler A, Heppe L, Sander U, Patzelt C, Lauerer M, Nagel E, Frömke C, Schöffski O, and Drach C
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- Humans, Middle Aged, Surveys and Questionnaires, Referral and Consultation, Hospitals, Randomized Controlled Trials as Topic, Intention, Physicians
- Abstract
Purpose: This study aims to determine the intention to use hospital report cards (HRCs) for hospital referral purposes in the presence or absence of patient-reported outcomes (PROs) as well as to explore the relevance of publicly available hospital performance information from the perspective of referring physicians., Methods: We identified the most relevant information for hospital referral purposes based on a literature review and qualitative research. Primary survey data were collected (May-June 2021) on a sample of 591 referring orthopedists in Germany and analyzed using structural equation modeling. Participating orthopedists were recruited using a sequential mixed-mode strategy and randomly allocated to work with HRCs in the presence (intervention) or absence (control) of PROs., Results: Overall, 420 orthopedists (mean age 53.48, SD 8.04) were included in the analysis. The presence of PROs on HRCs was not associated with an increased intention to use HRCs (p = 0.316). Performance expectancy was shown to be the most important determinant for using HRCs (path coefficient: 0.387, p < .001). However, referring physicians have doubts as to whether HRCs can help them. We identified "complication rate" and "the number of cases treated" as most important for the hospital referral decision making; PROs were rated slightly less important., Conclusions: This study underpins the purpose of HRCs, namely to support referring physicians in searching for a hospital. Nevertheless, only a minority would support the use of HRCs for the next hospital search in its current form. We showed that presenting relevant information on HRCs did not increase their use intention., (© 2023. The Author(s).)
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- 2024
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10. The use intention of hospital report cards among patients in the presence or absence of patient-reported outcomes.
- Author
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Emmert M, Schindler A, Drach C, Sander U, Patzelt C, Stahmeyer J, Kühnel E, Lauerer M, Nagel E, Frömke C, Schöffski O, and Heppe L
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- Aged, Health Policy, Hospitals, Humans, Surveys and Questionnaires, Intention, Patient Reported Outcome Measures
- Abstract
Background: So far, the adoption of hospital report cards (HRCs) falls short of expectations. One promising strategy is to modify the content of HRCs by presenting patient-reported outcomes (PROs)., Objective: To identify the key determinants influencing patients to use HRCs for hospital decision making and determine the effect of presenting PROs on HRCs on their use intention., Methods: Primary survey data were collected (5/6-2021) on a sample of 2000 randomly selected insurees from a German statutory health insurance who have undergone elective hip arthroplasty surgery., Results: Overall, 447 participants (mean age 66.56) completed the survey and were included in the analysis. Respondents rated "PROs" as most important for the hospital choice followed by "Mobility at hospital discharge" and "Confirmed diagnosis rate". Patients generally perceive HRCs to be a good idea that makes searching for a hospital more interesting. We identified attitude and social influence as the most important determinants for using HRCs (p<.001 each). The presence of PROs on HRCs was not associated with an increased intention to use HRCs neither in our descriptive analysis (p=.593), nor in our research model (p=.763)., Conclusions: Patients value PROs to be an important information for choosing a hospital. Nevertheless, health policy makers should note that presenting PROs on HRCs as a single approach is not likely to increase the use of HRCs., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2022
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11. Antibody-driven capture of synaptic vesicle proteins on the plasma membrane enables the analysis of their interactions with other synaptic proteins.
- Author
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Richter KN, Patzelt C, Phan NTN, and Rizzoli SO
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- Animals, Biotinylation, Exocytosis, Membrane Proteins isolation & purification, Rats, Antibodies immunology, Cell Membrane metabolism, Membrane Proteins immunology, Membrane Proteins metabolism, Synaptic Vesicles metabolism
- Abstract
Many organelles from the secretory pathway fuse to the plasma membrane, to exocytose different cargoes. Their proteins are then retrieved from the plasma membrane by endocytosis, and the organelles are re-formed. It is generally unclear whether the organelle proteins colocalize when they are on the plasma membrane, or whether they disperse. To address this, we generated here a new approach, which we tested on synaptic vesicles, organelles that are known to exo- and endocytose frequently. We tagged the synaptotagmin molecules of newly exocytosed vesicles using clusters of primary and secondary antibodies targeted against the luminal domains of these molecules. The antibody clusters are too large for endocytosis, and thus sequestered the synaptotagmin molecules on the plasma membrane. Immunostainings for other synaptic molecules then revealed whether they colocalized with the sequestered synaptotagmin molecules. We suggest that such assays may be in the future extended to other cell types and other organelles.
- Published
- 2019
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12. Do German public reporting websites provide information that office-based physicians consider before referring patients to hospital? A four-step analysis.
- Author
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Kolb B, Emmert M, Sander U, Patzelt C, and Schöffski O
- Subjects
- Germany, Humans, Internet, Physicians standards, Quality of Health Care standards, Referral and Consultation
- Abstract
Background: In recent years, many different performance frameworks and quality assurance systems have been developed to measure health care quality. In Germany, an external quality assurance system for hospitals was introduced in 2005. The data of these systems are often reported by public reporting websites (PRWs) to inform patients and other stakeholders interested in health care systems about health care providers' quality. However, publication is obligatory (at least in Germany) for most of the existing quality assurance measures; some may be reported voluntarily. An important target group for this information is the group of all office-based physicians as they are crucial for patients' hospital choice. However, public reporting initiatives in Germany and other countries have not increased the use of quality reports for hospital choice., Objectives: (1) To summarize the criteria that office-based physicians consider to be of high, medium, and low importance for hospital selection when referring patients and (2) to examine whether German public reporting websites (PRWs) provide these hospital-related criteria., Methods: The analysis comprised four steps: 1) Five databases were systematically searched for peer-reviewed English- and German-language literature. 2) The selection of articles was based on compliance with inclusion criteria, and all the criteria relevant to the referral of patients to hospital were extracted. 3) The criteria were then divided into five main categories: structural quality, process quality, outcome quality, patient experience, and referring physicians' experience. In addition, the criteria were classified into three importance categories (high-, medium-, and low-priority criteria) according to their relevance to the referral decision. 4) We investigated whether German PRWs publicly report high-priority criteria., Results: A total of N=11 articles published in peer-reviewed journals met our inclusion criteria. The studies were published in Germany (n=4), the Netherlands (n=3), Denmark, France, Norway, and the USA (n=1 each). In total, N=86 criteria were identified, most of them relating to structural quality (n=43) and process quality (n=26). We found just n=3 outcome quality criteria, only one of which fell in the high-priority category (breast cancer indicators with clinically relevant differences). In total, n=25 low-, n=40 medium-, and n=34 high-priority criteria could be established, which is due to the fact that some criteria had been investigated in several studies evaluating the importance of some criteria differently. Most of the high-priority criteria were related to process quality. All the high-priority structural quality criteria and high-priority outcome quality criteria were available on German PRWs, whereas just 38.5 % of those relating to process quality could be identified on these portals. We also identified 66.7 % of the high-priority criteria regarding patient experience and 50.0 % concerning the referring physicians' experience. Overall, a larger amount of low- and medium-priority criteria are available on German PRWs than high-priority criteria., Discussion: A substantial amount of hospital information regarding structural quality and outcome quality is available on German PRWs. However, the development of further process quality criteria (which are currently underrepresented) should be considered, for example whether hospital physicians continue the medication initiated by office-based doctors. Also, hospital quality reports should be tailored for specific user groups, for instance for referring gynecologists or referring general practitioners (GPs)., (Copyright © 2018. Published by Elsevier GmbH.)
- Published
- 2018
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13. Reaching the Elderly: Understanding of health and preventive experiences for a tailored approach - Results of a qualitative study.
- Author
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Patzelt C, Heim S, Deitermann B, Theile G, Krauth C, Hummers-Pradier E, and Walter U
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- Aged, Exercise, Female, Focus Groups, Germany, Humans, Male, Middle Aged, Needs Assessment, Preventive Health Services organization & administration, Preventive Health Services standards, Qualitative Research, Quality Improvement, Aging physiology, Aging psychology, Health Promotion methods, Healthcare Disparities standards, Independent Living psychology, Independent Living statistics & numerical data
- Abstract
Background: Often preventive measures are not accessed by the people who were intended to be reached. Programs for older adults may target men and women, older adults, advanced old age groups and/or chronically ill patients with specific indications. The defined target groups rarely participate in the conception of programs or in the design of information materials, although this would increase accessibility and participation. In the German "Reaching the Elderly" study (2008-2011), an approach to motivating older adults to participate in a preventive home visit (PHV) program was modified with the participatory involvement of the target groups. The study examines how older men and women would prefer to be addressed for health and prevention programs., Methods: Four focus groups (N = 42 participants) and 12 personal interviews were conducted (women and men in 2 age groups: 65-75 years and ≥ 76 years). Participants from two districts of a major German city were selected from a stratified random sample (N = 200) based on routine data from a local health insurance fund. The study focused on the participants' knowledge about health and disease prevention and how they preferred to be approached and addressed. Videos of the focus groups were recorded and analysed using mind mapping techniques. Interviews were digitally recorded, transcribed verbatim and subjected to qualitative content analysis., Results: A gender-specific approach profile was observed. Men were more likely to favor competitive and exercise-oriented activities, and they associated healthy aging with mobility and physical activity. Women, on the other hand, displayed a broader understanding of healthy aging, which included physical activity as only one aspect as well as a healthy diet, relaxation/wellness, memory training and independent living; they preferred holistic and socially oriented services that were not performance-oriented. The "older seniors" (76+) were ambivalent towards certain wordings referring to aging., Conclusions: Our results suggest that gender-specific needs must be considered in order to motivate older adults to participate in preventive services. Age-specific characteristics seem to be less relevant. It is more important to pay attention to factors that vary according to the individual state of health and life situation of the potential participants.
- Published
- 2016
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14. Iodine(III)-Catalyzed Cascade Reactions Enabling a Direct Access to β-Lactams and α-Hydroxy-β-amino Acids.
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Patzelt C, Pöthig A, and Gulder T
- Abstract
In the presented method, a one-pot metal-free access to β-lactams is provided. The developed strategy employs a hypervalent iodine(III)-triggered bromination/rearrangement/cyclization cascade reaction that allows the straightforward synthesis of a broad range of structurally different lactams from cheap and easily available imides. This triple cascade reaction is furthermore extendable by an in situ ring-opening reaction, giving direct access to isoserine derivatives from simple imines in a four-step, one-pot reaction.
- Published
- 2016
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15. Iodine(III)-catalyzed rearrangements of imides: a versatile route to α,α-dialkylated α-hydroxy carboxylamides.
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Ulmer A, Stodulski M, Kohlhepp SV, Patzelt C, Pöthig A, Bettray W, and Gulder T
- Abstract
A tertiary hydroxy group α to a carboxyl moiety comprises a key structural motif in many bioactive substances. With the herein presented metal-free rearrangement of imides triggered by hypervalent λ(3)-iodane, an easy and selective way to gain access to such a compound class, namely α,α-disubstituted-α-hydroxy carboxylamides, was established. Their additional methylene bromide side chain constitutes a useful handle for rapid diversification, as demonstrated by a series of further functionalizations. Moreover, the in situ formation of an iodine(III) species under the reaction conditions was proven. Our findings clearly corroborate that hypervalent λ(3)-benziodoxolones are involved in these organocatalytic reactions., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2015
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16. Uric acid monohydrate--a new urinary calculus phase.
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Schubert G, Reck G, Jancke H, Kraus W, and Patzelt C
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- Aged, Aged, 80 and over, Crystallization, Female, Humans, Magnetic Resonance Spectroscopy, Male, Middle Aged, Spectrophotometry, Infrared, Urinary Calculi ultrastructure, X-Ray Diffraction, Uric Acid analysis, Urinary Calculi chemistry
- Abstract
In our laboratory more than 100,000 urinary calculi have been analysed since 1972. Amongst this huge sample, 15 specimens originating from a total of eight patients were observed showing similar characteristics but escaping unambiguous identification with any of the substances that have been described so far in urinary concrements. Therefore, the unknown substance was submitted to a more extended analytical regimen. Structural analysis by x-ray crystallography turned out to be most successful, identifying the unknown material as uric acid monohydrate. Uric acid monohydrate crystallizes in the monocline space group P2(1)/c. Within the crystal, uric acid and water molecules form continuous layers by hydrogen bonds. This is in contrast to uric acid in its water free and its dihydrate forms, which both crystallize by forming 3-dimensional networks To the best of our knowledge , the existence of a monohydrate form of uric acid has not been reported so far. Accordingly, this is the first report on uric acid monohydrate as a urinary stone component. The frequency of only 0.015% in our survey indicates that uric acid monohydrate is rarely the main component in concrements, in contrast to uric acid and uric acid dihydrate with frequencies of 10% and 6%, respectively. The infrared spectrum of uric acid monohydrate is very similar to that of the other crystal forms of uric acid. Because of this similarity and its low frequency, uric acid monohydrate may have been overlooked as a component of urinary concrements. X-ray diffraction allows for better differentiation in routine stone analysis. All samples of uric acid monohydrate were found by solid state NMR spectroscopy to be highly contaminated by amorphous material. This material consisted of long aliphatic chains reminiscent of lipids and fatty acids, respectively. Concrements consisting of other forms of uric acid or urate lacked this amorphous component. Therefore, a role of this aliphatic material has to be taken into consideration when discussing the conditions that may favour the rare formation of concrements from uric acid monohydrate. As for as the metabolic situation of the affected patients is concerned, no common peculiarities became evident by a retrospective survey.
- Published
- 2005
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17. Conversion of proglucagon in pancreatic alpha cells: the major endproducts are glucagon and a single peptide, the major proglucagon fragment, that contains two glucagon-like sequences.
- Author
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Patzelt C and Schiltz E
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- Amino Acid Sequence, Animals, Dogs, Electrophoresis, Polyacrylamide Gel, Glucagon isolation & purification, Peptide Fragments isolation & purification, Proglucagon, Protein Biosynthesis, RNA, Messenger genetics, RNA, Messenger isolation & purification, Rats, Glucagon genetics, Islets of Langerhans metabolism, Peptide Fragments genetics, Protein Precursors genetics, Protein Processing, Post-Translational
- Abstract
It has previously been shown by biosynthetic labeling studies that glucagon is synthesized in mammalian islets via an 18-kDa precursor, proglucagon, that during processing gives rise to glucagon and a secreted peptide of 10 kDa (the major proglucagon fragment, MPGF). We have now developed a simple procedure for the isolation of this peptide from rat pancreatic islets and have characterized it more fully. On the basis of its amino acid composition, MPGF is identified as the COOH-terminal portion of proglucagon that contains two glucagon-related sequences. These sequences do not appear to be liberated from MPGF in alpha cells of the islets of Langerhans but MPGF may be processed further elsewhere in the body or in other cells of the gastrointestinal tract that produce glucagon precursors.
- Published
- 1984
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18. Identification of prosomatostatin in pancreatic islets.
- Author
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Patzelt C, Tager HS, Carroll RJ, and Steiner DF
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- Amino Acid Sequence, Islets of Langerhans cytology, Molecular Weight, Peptide Fragments analysis, Growth Hormone-Releasing Hormone metabolism, Islets of Langerhans metabolism, Protein Precursors metabolism
- Abstract
A 12.5-kilodalton protein not related to insulin or glucagon was detected in pulse-chase-labeled rat islets of Langerhans. Although this protein reacted poorly with various somatostatin antisera, analysis of two-dimensional peptide maps showed that it contains all of the tryptic fragments of somatostatin, which is located at its COOH terminus. Proteolytic conversion of the putative prosomatostatin, which took place parallel to the processing of proinsulin and proglucagon in pulse-chase experiments, coincided with the appearance of newly synthesized somatostatin and proceeded without the apparent involvement of major intermediate forms.
- Published
- 1980
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19. Colchicine-binding protein of the liver. Its characterization and relation to microtubules.
- Author
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Patzelt C, Singh A, Marchand YL, Orci L, and Jeanrenaud B
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- Animals, Binding Sites, Brain metabolism, Calcium pharmacology, Colchicine analogs & derivatives, Egtazic Acid pharmacology, Kinetics, Mice, Microtubules analysis, Protein Binding, Temperature, Time Factors, Tubulin analysis, Tubulin isolation & purification, Vinblastine pharmacology, Colchicine metabolism, Glycoproteins metabolism, Liver metabolism, Microtubules metabolism, Tubulin metabolism
- Abstract
Colchicine-binding activity of mouse liver high-speed supernate has been investigated. It has been found to be time and temperature dependent. Two binding activities with different affinities for colchicine seem to be present in this high-speed supernate, of which only the high-affinity binding site (half maximal binding at 5 x 10(-6) M colchicine) can be attributed to microtubular protein by comparison with purified tubulin. Vinblastine interacted with this binding activity by precipitating it when used at high concentrations (2 x 10(-3) M), and by stabilizing it at low concentrations (10(-5) M). Lumicolchicine was found not to compete with colchicine. The colchicine-binding activity was purified from liver and compared with that of microtubular protein from brain. The specific binding activity of the resulting preparation, its electrophoretic behavior, and the electron microscope appearance of the paracrystals obtained upon its precipitation with vinblastine permitted its identification as microtubular protein (tubulin). Electrophoretic analysis of the proteins from liver supernate that were precipitated by vinblastine indicated that this drug was not specific for liver tubulin. Preincubation of liver supernate with 5 mM EGTA resulted in a time-dependent decrease of colchicine-binding activity, which was partly reversed by the addition of Ca++. However, an in vitro formation of microtubules upon lowering the Ca++ concentration could not be detected. Finally, a method was developed enabling that portion of microtubular protein which was present as free tubulin to be measured and to be compared with the total amount of this protein in the tissue. This procedure permitted demonstration of the fact that, under normal conditions, only about 40% of the tubulin of the liver was assemled as microtubules. It is suggested that, in the liver, rapid polymerization and depolymerization of microtubules occur and may be an important facet of the functional role of the microtubular system.
- Published
- 1975
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20. Detection and kinetic behavior of preproinsulin in pancreatic islets.
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Patzelt C, Labrecque AD, Duguid JR, Carroll RJ, Keim PS, Heinrikson RL, and Steiner DF
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- Adenoma, Islet Cell metabolism, Amino Acid Sequence, Animals, Glucose pharmacology, Insulin, Kinetics, Neoplasms, Experimental metabolism, Pancreatic Neoplasms metabolism, Peptide Fragments, Rats, Islets of Langerhans metabolism, Proinsulin biosynthesis, Protein Precursors metabolism
- Abstract
Newly synthesized rat islet proteins have been analyzed by polyacrylamide slab gel electrophoresis and fluorography. A minor component having an apparent molecular weight of 11,100 was identified as preproinsulin by the sensitivity of its synthesis to glucose, the pattern of NH2-terminal leucine residues, and the rapidity of its appearance and disappearance during incubation of islets or islet cell tumors. A small amount of labeled peptide material which may represent the excised NH2-terminal extension of preproinsulin or its fragment was also detected. The kinetics of formation and processing of the preproinsulin fraction were complex, consisting of a rapidly turning over component having a half-life of about 1 min and a slower minor fraction that may have bypassed the normal cleavage process. The electrophoretic resolution of the preproinsulin and proinsulin fractions into two bands each is consistent with the presence of two closely related gene products in rat islets rather than intermediate stages in the processing of these peptides.
- Published
- 1978
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21. The major proglucagon fragment: an abundant islet protein and secretory product.
- Author
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Patzelt C and Schug G
- Subjects
- Animals, Arginine pharmacology, Electrophoresis, Polyacrylamide Gel, Islets of Langerhans metabolism, Peptide Fragments isolation & purification, Proglucagon, Rats, Glucagon metabolism, Islets of Langerhans analysis, Peptide Fragments metabolism, Protein Precursors metabolism
- Published
- 1981
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22. Evidence for a role of the microtubular system in the secretion of newly synthesized albumin and other proteins by the liver.
- Author
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Le Marchand Y, Patzelt C, Assimacopoulos-Jeannet F, Loten EG, and Jeanrenaud B
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- Albumins biosynthesis, Amino Acids metabolism, Animals, Carbon Radioisotopes, Cattle, Chromatography, Chromatography, Gel, Colchicine pharmacology, Globulins metabolism, Liver drug effects, Liver metabolism, Male, Mice, Peptides metabolism, Perfusion, Protein Biosynthesis, Vinblastine pharmacology, Vincristine pharmacology, Albumins metabolism, Liver cytology, Microtubules physiology, Proteins metabolism
- Abstract
Livers of normal mice were prefused in situ and the secretion of newly synthesized (i.e. labeled) proteins into the perfusate were measured. In control livers, the secretion of newly synthesized proteins was found to be linear with time. In marked contrast, when livers were perfused with vinblastine, vincristine, or colchicine, drugs known to interfere with the hepatic microtubular system, the release of newly synthesized proteins was either strongly inhibited or completely suppressed although total hepatic protein synthesis (estimated by the incorporation of labeled amino acids into hepatic plus perfusate proteins) remained unaltered. Chromatographic separation of the various secreted proteins showed that the release of albumin, globulins, and small polypeptides was decreased to a similar extent by vincristine or colchicine. In the particular case of albumin, it was further observed that total (i.e. liver plus perfusate) labeled amino acid incorporation into albumin was not altered by either vincristine or colchicine, whereas the incorporation of these amino acids into liver albumin was markedly increased but incorporation into perfusate albumin was decreased, suggesting that the translocation of this particular protein from the liver to the perfusate had been affected by the presence of these drugs. It is proposed that the functional integrity of microtubules is necessary for the intracellular movement and eventual release of albumin and other proteins by the liver, and suggested that microtubules might possibly be a site of regulation of hepatic protein secretion.
- Published
- 1974
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23. Studies on the biosynthesis of the other peptide hormones of the rat islets of Langerhans.
- Author
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Patzelt C, Neilsen D, Carroll R, Quinn P, Lernmark A, Tager HS, and Steiner DF
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- Animals, Electrophoresis, Polyacrylamide Gel, Molecular Weight, Rats, Glucagon biosynthesis, Islets of Langerhans metabolism, Pancreatic Polypeptide biosynthesis, Protein Precursors biosynthesis, Somatostatin biosynthesis
- Published
- 1980
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24. Biosynthesis of insulin and glucagon.
- Author
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Tager HS, Steiner DF, and Patzelt C
- Subjects
- Animals, Cytoplasmic Granules metabolism, Endoplasmic Reticulum metabolism, Glucagon metabolism, Golgi Apparatus metabolism, Insulin genetics, Intestines, Microsomes metabolism, Proglucagon, Proinsulin metabolism, Protein Precursors metabolism, Glucagon biosynthesis, Insulin biosynthesis, Islets of Langerhans metabolism
- Published
- 1981
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25. Identification and processing of proglucagon in pancreatic islets.
- Author
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Patzelt C, Tager HS, Carroll RJ, and Steiner DF
- Subjects
- Animals, Glucagon immunology, Kinetics, Molecular Weight, Peptide Fragments metabolism, Protein Precursors immunology, Rats, Glucagon biosynthesis, Islets of Langerhans metabolism, Protein Precursors metabolism
- Abstract
Immunoprecipitation and tryptic peptide analysis of newly synthesized proteins from rat islets have identified an 18,000 molecular weight (MW) protein as proglucagon. Conversion of this precursor was kinetically similar to the conversion of proinsulin and resulted in the formation of both pancreatic glucagon and a 10,000-MW protein lacking this hormonal sequence.
- Published
- 1979
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26. Biosynthesis of islet cell hormones.
- Author
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Tager HS, Patzelt C, Assoian RK, Chan SJ, Duguid JR, and Steiner DF
- Subjects
- Animals, DNA metabolism, Endopeptidases metabolism, Kinetics, Mice, Molecular Weight, Nucleic Acid Hybridization, Peptide Fragments analysis, Proinsulin metabolism, Protein Biosynthesis, RNA, Messenger metabolism, Rats, Transcription, Genetic, Glucagon biosynthesis, Insulin biosynthesis, Islets of Langerhans metabolism, Protein Precursors biosynthesis, Somatostatin biosynthesis
- Published
- 1980
- Full Text
- View/download PDF
27. Early O-glycosidic glycosylation of proglucagon in pancreatic islets: an unusual type of prohormonal modification.
- Author
-
Patzelt C and Weber B
- Subjects
- Animals, Carbon Radioisotopes, Glycoproteins biosynthesis, Glycoproteins genetics, Lectins, Methionine metabolism, Proglucagon, Protein Biosynthesis, Protein Processing, Post-Translational, Rats, Sulfur Radioisotopes, Threonine metabolism, Tritium, Galactosamine metabolism, Glucagon metabolism, Islets of Langerhans metabolism, Plant Lectins, Protein Precursors metabolism, Soybean Proteins
- Abstract
Proglucagon from rat islets is identified as a glycoprotein by its binding to soybean lectin and by the biosynthetic incorporation of [14C]galactosamine. Glycosylation can be demonstrated for both forms of proglucagon, i.e. the primary translation product which is detectable as early as 30 s after incubation of isolated islets with radioactive amino acids (proglucagon a), and its conversion product of slightly higher electrophoretic mobility which is formed after 5-10 min of incubation (proglucagon b). This glycosylation is determined to be of the O-glycosidic type by the following criteria: rat proglucagon has previously been shown to lack an acceptor sequence for N-glycosidic linkage of sugars, the sugar bond in rat proglucagon is labile under mild alkaline conditions, glycosylated serine is demonstrated in proteolytic lysates of both the early and the late form of this prohormone. O-glycosidic linkage of sugars has not been reported for other prohormones. Its early formation and the apparent absence of N-glycosidically bound sugars in proglucagon give evidence for an unusual type of protein glycosylation.
- Published
- 1986
- Full Text
- View/download PDF
28. Inhibitory effect of colchicine on amylase secretion by rat parotid glands. Possible localization in the Golgi area.
- Author
-
Patzelt C, Brown D, and Jeanrenaud B
- Subjects
- Amylases biosynthesis, Animals, Binding Sites, Colchicine metabolism, Culture Techniques, Cytoplasmic Granules ultrastructure, Depression, Chemical, Golgi Apparatus drug effects, Golgi Apparatus ultrastructure, Isoproterenol pharmacology, Male, Microtubules metabolism, Parotid Gland drug effects, Parotid Gland ultrastructure, Rats, Tubulin metabolism, Amylases metabolism, Colchicine pharmacology, Golgi Apparatus enzymology, Parotid Gland enzymology
- Abstract
Colchicine inhibited amylase secretion by isolated rat parotid glands only 6 h after administration of the drug in vivo. This delayed effect was not the result of the inability of the drug to reach its reaction site. When parotid glands were emptied of their secretory granules by isoproterenol treatment, the subsequent replenishment of cells with granules was inhibited by colchicines. Colchicine concomitantly produced alterations of the Golgi complexes, the cisternae of which were reduced in size and surrounded by clusters of microvesicles. Incubation of parotid glands with colchicines for prolonged durations failed to alter stored amylase secretion as stimulated by isoproterenol, but it inhibited the release of de novo synthesized enzyme. Another colchicines-binding activity, firmly bound to the particular fraction of homogenates, was found, of which a part may represent membrane located microtubular protein. An assembly-disassembly cycle of microtubules appears to exist in the parotid gland, as in the liver. However, only 14 percent of tubulin was found to be polymerized as microtubules in parotid glands as opposed to 40 percent in the liver. The present data suggest that colchicine primarily inhibits the transfer of secretory material towards or away from the Golgi complexes but not the hormone-stimulated secretion of stored amylase.
- Published
- 1977
- Full Text
- View/download PDF
29. Active and inactive forms of pyruvate dehydrogenase in rat liver. Effect of starvation and refeeding and of insulin treatment on pyruvate-dehydrogenase interconversion.
- Author
-
Wieland OH, Patzelt C, and Löffler G
- Subjects
- Animal Nutritional Physiological Phenomena, Animals, Coenzyme A metabolism, Dietary Carbohydrates, Enzyme Activation, Fatty Acids blood, Fatty Acids pharmacology, Feedback, Glucose pharmacology, Kidney enzymology, Male, Myocardium enzymology, Nicotinic Acids pharmacology, Oleic Acids pharmacology, Rats, Starvation, Insulin pharmacology, Liver enzymology, Oxidoreductases metabolism, Pyruvates
- Published
- 1972
- Full Text
- View/download PDF
30. Interconversion of pyruvate dehydrogenase in the isolated perfused rat liver.
- Author
-
Patzelt C, Löffler G, and Wieland OH
- Subjects
- Animals, Carnitine pharmacology, Enzyme Activation, Enzyme Induction, Fatty Acids physiology, Fructose pharmacology, Glucose pharmacology, In Vitro Techniques, Lactates pharmacology, Liver drug effects, Oleic Acids pharmacology, Perfusion, Pyruvate Dehydrogenase Complex metabolism, Pyruvates pharmacology, Pyruvates physiology, Rats, Starvation, Stimulation, Chemical, Liver enzymology, Multienzyme Complexes metabolism
- Published
- 1973
- Full Text
- View/download PDF
31. Regulation of the mammalian pyruvate dehydrogenase complex by covalent modification.
- Author
-
Wieland OH, Siess EA, Weiss L, Löffler G, Patzelt C, Portenhauser R, Hartmann U, and Schirmann A
- Subjects
- Adenosine Triphosphate, Adipose Tissue enzymology, Animals, Brain enzymology, Calcium, Carnitine, DNA analysis, Enzyme Activation, Fatty Acids, Nonesterified blood, In Vitro Techniques, Insulin, Kidney enzymology, Liver enzymology, Magnesium, Mice, Mice, Inbred Strains, Mitochondria, Liver metabolism, Myocardium enzymology, Neurospora crassa, Obesity, Oleic Acids, Palmitic Acids, Phosphorus Radioisotopes, Pyruvates, Rats, Swine, Pyruvate Dehydrogenase Complex metabolism
- Published
- 1973
Catalog
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