89 results on '"Bossart M"'
Search Results
2. Biomarker-based early detection of epithelial ovarian cancer based on a five-protein signature in patient’s plasma – a prospective trial
- Author
-
Hasenburg, A., Eichkorn, D., Vosshagen, F., Obermayr, E., Geroldinger, A., Zeillinger, R., and Bossart, M.
- Published
- 2021
- Full Text
- View/download PDF
3. Video-assisted thoracic surgery (VATS) evaluation of intrathoracic disease in patients with FIGO III and IV stage ovarian cancer
- Author
-
Klar, M., Farthmann, J., Bossart, M., Stremmel, C., Gitsch, G., Passlick, B., Pache, G., Woll, J., and Hasenburg, A.
- Published
- 2012
- Full Text
- View/download PDF
4. Sentinel lymph node detection in patients with vulvar carcinoma; Feasibility of intra-operative mapping with technetium-99m-labeled nanocolloid
- Author
-
Klar, M., Bossart, M., Stickeler, E., Brink, I., Orlowska-Volk, M., and Denschlag, D.
- Published
- 2011
- Full Text
- View/download PDF
5. A pilot study of an HbA1c chairside screening protocol for diabetes in patients with chronic periodontitis: the dental hygienistʼs role
- Author
-
Bossart, M, Calley, KH, Gurenlian, JR, Mason, B, Ferguson, RE, and Peterson, T
- Published
- 2016
- Full Text
- View/download PDF
6. The need for accredited training in gynaecological oncology: a report from the European Network of Young Gynaecological Oncologists (ENYGO)
- Author
-
Manchanda, R., Godfrey, M., Wong-Taylor, L. A., Halaska, M. J., Burnell, M., Grabowski, J. P., Gultekin, M., Haidopoulos, D., Zapardiel, I., Vranes, B., Kesic, V., Zola, P., Colombo, N., Verheijen, R., Bossart, M., and Piek, J.
- Published
- 2013
- Full Text
- View/download PDF
7. First-in-class positron emission tomography tracer for the glucagon receptor
- Author
-
Velikyan, I., Haack, T., Bossart, M., Evers, A., Laitinen, I., Larsen, P., Plettenburg, O., Johansson, L., Pierrou, S., Wagner, M., and Eriksson, O.
- Subjects
gallium 68 ,positron emission tomography ,Dual agonist ,Ga DO3A S02 GCG ,GLP-1 receptor ,autoradiography ,cAMP assay ,binding affinity ,rat ,receptor occupancy ,Ga DO3A S01 GCG ,isotope labeling ,phosphorus ,radiochemistry ,cysteine ,Original Research ,liver tissue ,dosimetry ,effective dose (radiation) ,adult ,Type 2 diabetes ,tracer ,peptide ,unclassified drug ,radiopharmaceutical agent ,female ,priority journal ,receptor affinity ,HEK293 cell line ,radioactivity ,retention time ,Radiology, Nuclear Medicine and Medical Imaging ,lcsh:Medical physics. Medical radiology. Nuclear medicine ,high performance liquid chromatography ,gene overexpression ,lcsh:R895-920 ,body weight ,male ,controlled study ,ddc:610 ,human ,radioisotope ,quality control ,glucagon like peptide 1 receptor agonist ,liver biopsy ,carboxy terminal sequence ,nonhuman ,gadoteridol ,exendin 4 ,animal model ,human cell ,GCG ,antidiabetic agent ,glucagon receptor ,Glucagon ,body weight loss ,human tissue ,internalization ,glucagon receptor agonist ,Radiologi och bildbehandling ,Dewey Decimal Classification::600 | Technik::610 | Medizin, Gesundheit ,Gcg ,Glp-1 Receptor ,Dual Agonist ,Type 2 Diabetes ,glucagon like peptide 1 - Abstract
The glucagon receptor (GCGR) is emerging as an important target in anti-diabetic therapy, especially as part of the pharmacology of dual glucagon-like peptide-1/glucagon (GLP-1/GCG) receptor agonists. However, currently, there are no suitable biomarkers that reliably demonstrate GCG receptor target engagement. Methods Two potent GCG receptor peptide agonists, S01-GCG and S02-GCG, were labeled with positron emission tomography (PET) radionuclide gallium-68. The GCG receptor binding affinity and specificity of the resulting radiopharmaceuticals [68Ga]Ga-DO3A-S01-GCG and [68Ga]Ga-DO3A-S02-GCG were evaluated in HEK-293 cells overexpressing the human GCG receptor and on frozen hepatic sections from human, non-human primate, and rat. In in vivo biodistribution, binding specificity and dosimetry were assessed in rat. Results [68Ga]Ga-DO3A-S01-GCG in particular demonstrated GCG receptor-mediated binding in cells and liver tissue with affinity in the nanomolar range required for imaging. [68Ga]Ga-DO3A-S01-GCG binding was not blocked by co-incubation of a GLP-1 agonist. In vivo binding in rat liver was GCG receptor specific with low non-specific binding throughout the body. Moreover, the extrapolated human effective doses, predicted from rat biodistribution data, allow for repeated PET imaging potentially also in combination with GLP-1R radiopharmaceuticals. Conclusion [68Ga]Ga-DO3A-S01-GCG thus constitutes a first-in-class PET tracer targeting the GCG receptor, with suitable properties for clinical development. This tool has potential to provide direct quantitative evidence of GCG receptor occupancy in humans. Electronic supplementary material The online version of this article (10.1186/s13550-019-0482-0) contains supplementary material, which is available to authorized users.
- Published
- 2019
8. 876P The effect of surgical techniques on sexuality and global quality of life (Qol) in women with ovarian germ cell (OGCT) and sex cord stromal tumours (SCST): An analysis of the AGO-CORSETT database
- Author
-
Hasenburg, A., Plett, H., Krämer, B., Braicu, E., Czogalla, B., Bossart, M., Singer, S., Mayr, D., Staebler, A., du Bois, A., Kommoss, S., Link, T., Burges, A., Heitz, F., Keul, J., Trillsch, F., Harter, P., Wimberger, P., Buderath, P., and Klar, M.
- Published
- 2020
- Full Text
- View/download PDF
9. MULTIPOTENTIAL CELLS IN THE CIRCULATING BLOOD: ULTRASTRUCTURAL EVIDENCE IN THE CALF
- Author
-
Bossart, M. I., Turner, S. A., Milam, J. D., Connor, D. J., Urrutia, C. O., and Frazier, O. H.
- Published
- 1982
10. HUMAN PSEUDONEOINTIMAL (PNI) ACCRETION KINETICS DURING ABDOMINAL LEFT VENTRICULAR ASSIST DEVICE (ALVAD) UTILIZATION IN MAN: A REPLICATING SEQUENCE
- Author
-
Trono, R., Holub, D. A., McGee, M. G., Fuhrman, T. M., Hibbs, C. W., Fuqua, J. M., Edmonds, C. H., Sturm, J. T., Bossart, M. I., Milam, J. D., and Norman, J. C.
- Published
- 1979
11. 443 The German Cohort of the TEAM Trial: Does Prior Chemotherapy Affect the Efficacy of Endocrine Therapy?
- Author
-
Bossart, M., Hadji, P., Kieback, D., and Hasenburg, A.
- Published
- 2012
- Full Text
- View/download PDF
12. Anastomosis of bypass grafts using a low-powered CO2 laser.
- Author
-
Frazier, O. H., Shehab, S. Anne, Zirl, Robert, Radovancevic, Branislav, Nakatani, Takeshi, Bossart, Mattie I., Parnis, Steven M., Shehab, S A, Zirl, R, Radovancevic, B, Nakatani, T, Bossart, M I, and Parnis, S M
- Published
- 1989
- Full Text
- View/download PDF
13. ULTRASTRUCTURAL ANALYSES OF STONE HEART SYNDROME AT ONSET AND SIX DAYS LATER FOLLOWING TOTAL SUPPORT OF THE CIRCULATION WITH A PARTIAL ARTIFICIAL HEART OR LEFT VENTRICULAR ASSIST DEVICE (ALVAD)
- Author
-
Sturm, J. T., Bossart, M. I., Holub, D. A., Milam, J. D., and Norman, J. C.
- Subjects
cardiovascular system ,Articles - Abstract
Ischemic myocardial contracture developed in a 21-year-old man following aortic and mitral valve replacement. The patient's circulation was supported totally for 6 days with an abdominal left ventricular assist device (ALVAD). Cardiac allografting was then undertaken. Samples of myocardium taken at the original operation and 6 days later at transplantation were analyzed ultrastructurally. At the onset of ischemic cortracture, left ventricular abnormalities included hypercontraction of myofibrils, loss of normal A-band and Z-band patterns, mitochondrial swelling with fusion of cristae, interfibrillar edema and glycogen depletion. Capillaries demonstrated swelling of endothelial cells and basement membrane disruption. Six days later, ultrastructural morphology showed further degeneration. The myofibrils remained hypercontracted, but were more fragmented. Degenerative changes in mitochondria were more advanced and calcium deposition in cristae was present. No glycogen was seen. The right ventricular myocardium exhibited significantly fewer ultrastructural abnormalities. The principal right ventricular changes were endothelial swelling and basement membrane disruption. Glycogen granules were present. Ischemic contracture affects the left ventricle more than the right, and the morphology becomes more abnormal with time. To our knowledge, this is the first instance wherein morphologic progressions of the ultrastructural alterations of ischemic contracture have been documented.
- Published
- 1979
14. Algebraic soft decoding of multilevel codes with inner convolutional code.
- Author
-
Schnug, W., Griatler, H., Schmidt, G., and Bossart, M.
- Published
- 2001
- Full Text
- View/download PDF
15. ChemInform Abstract: Stereoselective Phenyl Migration from Silicon to Carbon.
- Author
-
STUDER, A., BOSSART, M., and STEEN, H.
- Published
- 1999
- Full Text
- View/download PDF
16. ChemInform Abstract: Stereoselective Radical Aryl Migrations from Sulfur to Carbon.
- Author
-
STUDER, A. and BOSSART, M.
- Published
- 1999
- Full Text
- View/download PDF
17. The work place educational: climate in gynecological oncology fellowships across Europe: the impact of accreditation
- Author
-
Jurgen M.J. Piek, Vesna Kesic, René H.M. Verheijen, Jacek P. Grabowski, Michael J. Halaska, Michaela Bossart, Klarke Boor, Ignacio Zapardiel, Dimitrios Haidopoulos, Nicoletta Colombo, David Cibula, Ranjit Manchanda, Piek, J, Bossart, M, Boor, K, Halaska, M, Haidopoulos, D, Zapardiel, I, Grabowski, J, Kesic, V, Cibula, D, Colombo, N, Verheijen, R, and Manchanda, R
- Subjects
Adult ,Male ,medicine.medical_specialty ,Medical psychology ,Students, Medical ,media_common.quotation_subject ,education ,Medical Oncology ,Coaching ,Likert scale ,Accreditation ,Cronbach's alpha ,Surveys and Questionnaires ,medicine ,Journal Article ,Humans ,gynecological oncology fellowships european network of young gynecological oncologists training education ,Fellowships and Scholarships ,TUTOR ,Workplace ,computer.programming_language ,media_common ,Medical education ,Teamwork ,business.industry ,Obstetrics and Gynecology ,Internship and Residency ,Test (assessment) ,Europe ,Oncology ,Gynecology ,Family medicine ,Education, Medical, Continuing ,Female ,business ,computer ,Follow-Up Studies - Abstract
BackgroundA good educational climate/environment in the workplace is essential for developing high-quality medical (sub)specialists. These data are lacking for gynecological oncology training.ObjectiveThis study aims to evaluate the educational climate in gynecological oncology training throughout Europe and the factors affecting it.MethodsA Web-based anonymous survey sent to ENYGO (European Network of Young Gynecological Oncologists) members/trainees to assess gynecological oncology training. This included sociodemographic information, details regarding training posts, and a 50-item validated Dutch Residency Educational Climate Test (D-RECT) questionnaire with 11 subscales (1–5 Likert scale) to assess the educational climate. The χ2 test was used for evaluating categorical variables, and the Mann-Whitney U (nonparametric) test was used for continuous variables between 2 independent groups. Cronbach α assessed the questionnaire reliability. Multivariable linear regression assessed the effect of variables on D-RECT outcome subscales.ResultsOne hundred nineteen gynecological oncological fellows responded. The D-RECT questionnaire was extremely reliable for assessing the educational environment in gynecological oncology (subscales’ Cronbach α, 0.82–0.96). Overall, trainees do not seem to receive adequate/effective constructive feedback during training. The overall educational climate (supervision, coaching/assessment, feedback, teamwork, interconsultant relationships, formal education, role of the tutor, patient handover, and overall consultant’s attitude) was significantly better (P = 0.001) in centers providing accredited training in comparison with centers without such accreditation. Multivariable regression indicated the main factors independently associated with a better educational climate were presence of an accredited training post and total years of training.ConclusionsThis study emphasizes the need for better feedback mechanisms and the importance of accreditation of centers for training in gynecological oncology to ensure training within higher quality clinical learning climates.
- Published
- 2015
18. Introduction of a fatty acid chain modification to prolong circulatory half-life of a radioligand towards glucose-dependent insulinotropic polypeptide receptor.
- Author
-
Khalil A, Hakhverdyan S, Cheung P, Bossart M, Wagner M, Eriksson O, and Velikyan I
- Subjects
- Rats, Humans, Animals, Swine, HEK293 Cells, Ligands, Half-Life, Albumins, Amino Acids, Gallium Radioisotopes chemistry, Peptides chemistry, Receptors, Gastrointestinal Hormone
- Abstract
Background: The beneficial role of glucose-dependent insulinotropic polypeptide receptor (GIPR) in weight control and maintaining glucose levels has led to the development of several multi-agonistic peptide drug candidates, targeting GIPR and glucagon like peptide 1 receptor (GLP1R) and/or the glucagon receptor (GCGR). The in vivo quantification of target occupancy by these drugs would accelerate the development of new drug candidates. The aim of this study was to evaluate a novel peptide (GIP1234), based on previously reported ligand DOTA-GIP-C803, modified with a fatty acid moiety to prolong its blood circulation. It would allow higher target tissue exposure and consequently improved peptide uptake as well as in vivo PET imaging and quantification of GIPR occupancy by novel drugs of interest., Method: A 40 amino acid residue peptide (GIP1234) was synthesized based on DOTA-GIP-C803, in turn based on the sequences of endogenous GIP and Exendin-4 with specific amino acid modifications to obtain GIPR selectivity. A palmitoyl fatty acid chain was furthermore added at Lys14 via a glutamic acid linker to prolong its blood circulation time by the interaction with albumin. GIP1234 was conjugated with a DOTA chelator at the C-terminal cysteine residue to achieve
68 Ga radiolabeling. The resulting PET probe, [68 Ga]Ga-DOTA-GIP1234 was evaluated for receptor binding specificity and selectivity using HEK293 cells transfected with human GIPR, GLP1R, or GCGR. Blocking experiments with tirzepatide (2 μM) were conducted using huGIPR HEK293 cells to investigate binding specificity. Ex vivo and in vivo organ distribution of [68 Ga]Ga-DOTA-GIP1234 was studied in rats and a pig in comparison to [68 Ga]Ga-DOTA-C803-GIP. Binding of [68 Ga]Ga-DOTA-GIP1234 to albumin was assessed in situ using polyacrylamide gel electrophoresis (PAGE). The stability was tested in formulation buffer and rat blood plasma., Results: [68 Ga]Ga-DOTA-GIP1234 was synthesized with non-decay corrected radiochemical yield of 88 ± 3.7 % and radiochemical purity of 97.8 ± 0.8 %. The molar activity for the radiotracer was 8.1 ± 1.1 MBq/nmol. [68 Ga]Ga-DOTA-GIP1234 was stable and maintained affinity to huGIPR HEK293 cells (dissociation constant (Kd ) = 40 ± 12.5 nM). The binding of [68 Ga]Ga-DOTA-GIP1234 to huGCGR and huGLP1R cells was insignificant. Pre-incubation of huGIPR HEK293 cell sections with tirzepatide resulted in the decrease of [68 Ga]Ga-DOTA-GIP1234 binding by close to 90 %. [68 Ga]Ga-DOTA-GIP1234 displayed slow blood clearance in pigs with SUV = 3.5 after 60 min. Blood retention of the tracer in rat was 2-fold higher than that of [68 Ga]Ga-DOTA-C803-GIP. [68 Ga]Ga-DOTA-GIP1234 also demonstrated strong liver uptake in both pig and rat combined with decreased renal excretion. The concentration dependent binding of [68 Ga]Ga-DOTA-GIP1234 to albumin was confirmed in situ by PAGE., Conclusion: [68 Ga]Ga-DOTA-GIP1234 demonstrated nanomolar affinity and selectivity for huGIPR in vitro. Addition of a fatty acid moiety prolonged blood circulation time and tissue exposure in both rat and pig in vivo. However, the liver uptake was also increased which may make PET imaging of abdominal tissues such as pancreas challenging. The investigation of the influence of fatty acid moiety on the biological performance of the peptide ligand paved the way for further rational design of GIPR ligand analogues with improved characteristics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Martin Bossart is an employee of Sanofi Germany. Michael Wagner is an employee of Dewpoint Therapeutics. Olof Eriksson is an employee of Antaros Medical AB and a shareholder of Antaros Tracer AB. No other potential conflicts of interest relevant to this article exist., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2024
- Full Text
- View/download PDF
19. European Medicinal Chemistry Leaders in Industry (EMCL) - On the Status and Future of Medicinal Chemistry Research in Europe.
- Author
-
Ali A, Bauser M, Bertrand S, Blackaby W, Boss C, Bossart M, Hall A, Binch H, Czechtizky W, Gijsen H, Haning H, Hartung IV, Kilburn P, Lassalle G, Lücking U, Mack J, Missbach M, Otsomaa L, Torrens A, Wagner M, Walter M, Weinstabl H, van Hijfte L, and von Nussbaum F
- Subjects
- Ecosystem, Europe, Chemistry, Pharmaceutical, Drug Industry
- Abstract
The status of industrial Medicinal Chemistry was discussed with European Medicinal Chemistry Leaders from large to mid-sized pharma and CRO companies as well as biotechs. The chemical modality space has expanded recently from small molecules to address new challenging targets. Besides the classical SAR/SPR optimization of drug molecules also their 'greenness' has increasing importance. The entire pharma discovery ecosystem has developed significantly. Beyond pharma and academia new key players such as Biotech and integrated CROs as well as Digital companies have appeared and are now to a large extend fueled by VC money. Digitalization is happening everywhere but surprisingly did not change speed and success rates of projects so far. Future Medicinal Chemists will still have to be excellent synthetic chemists but in addition they must be knowledgeable in new computational areas such as data sciences. Their ability to collaborate and to work in teams is key., (© 2023 Wiley-VCH GmbH.)
- Published
- 2023
- Full Text
- View/download PDF
20. Treatment and survival of patients with malignant ovarian sex cord-stromal cell tumours: An analysis of the Arbeitsgemeinschaft für Gynäkologische Onkologie (AGO) study group CORSETT database.
- Author
-
Klar M, Plett H, Harter P, Heitz F, Kommoss S, Hartkopf AD, Grube M, Roser E, Sehouli J, Braicu I, Czogalla B, Burges A, Bossart M, Hasanov MF, Link T, Staebler A, Mayr D, Buderath P, and Hasenburg A
- Subjects
- Female, Humans, Prospective Studies, Lymph Nodes pathology, Ovarian Neoplasms pathology, Granulosa Cell Tumor pathology, Granulosa Cell Tumor therapy, Sex Cord-Gonadal Stromal Tumors surgery, Soft Tissue Neoplasms pathology
- Abstract
Background: Malignant sex cord-stromal cell tumours (SCST) account for only 7% of ovarian malignancies. The Arbeitsgemeinschaft fuer Gynaekologische Onkologie (AGO) study group has established a clinicopathological database to provide an overview of the current treatment strategies and survival of SCST patients and to identify research needs., Methods: Twenty centres provided mixed retro- and prospective data of patients with tumour specimens and second-opinion pathology review treated between 2000 and 2014. Descriptive analyses of treatment strategies, Kaplan-Meier curves and cox regression analyses were conducted., Results: Two hundred and sixty-two SCST patients were included. One hundred and ninety-one Granulosa-cell tumour (GCT) and 17 Sertoli-Leydig cell tumour (SLCT) patients were stage I disease (>80%). Forty four GCT (18.7%) and two (8.3%) SLCT patients received adjuvant systemic treatment. After a median observation time of 78.2 months, 46% of all SCST patients experienced disease recurrence, treated predominantly with secondary debulking surgery (> 90%). Advanced FIGO stage, lymph node involvement and intra-operative capsule rupture were associated with disease recurrence on univariate analysis (all p < 0.05). Median OS time was not reached., Discussion: In this analysis of SCST patients, adjuvant chemotherapy was unable to prevent disease recurrence. Despite high recurrence rates, overall survival rates were excellent., (© 2023 The Authors. Journal of Surgical Oncology published by Wiley Periodicals LLC.)
- Published
- 2023
- Full Text
- View/download PDF
21. Prognostic factors and survival of patients with uterine sarcoma: a German unicenter analysis.
- Author
-
Huss A, Klar M, Hasanov MF, Juhasz-Böss I, and Bossart M
- Subjects
- Female, Humans, Adolescent, Young Adult, Adult, Middle Aged, Aged, Aged, 80 and over, Prognosis, Retrospective Studies, Receptors, Progesterone, Neoplasm Recurrence, Local pathology, Survival Rate, Sarcoma pathology, Uterine Neoplasms pathology, Leiomyosarcoma surgery, Endometrial Stromal Tumors, Pelvic Neoplasms, Sarcoma, Endometrial Stromal pathology, Endometrial Neoplasms pathology
- Abstract
Purpose: Uterine sarcoma (US) as a histologically heterogeneous group of tumors is rare and associated with poor prognosis. Prognostic factors based on systematic data collection need to be identified to optimize patients' treatment., Methods: This unicenter, retrospective cohort study includes 57 patients treated at the University Hospital Freiburg, Germany between 1999 and 2017. Progression-free survival (PFS) and overall survival (OS) were calculated and visualized in Kaplan-Meier curves. Prognostic factors were identified using log-rank test and Cox regression., Results: 44 Leiomyosarcoma (LMS), 7 low-grade endometrial stromal sarcoma (LG-ESS), 4 high-grade ESS and 2 undifferentiated US patients were identified. The median age at time of diagnosis was 51.0 years (range 18-83). The median follow-up time was 35 months. PFS for the total cohort was 14.0 (95%-Confidence-Interval (CI) 9.7-18.3) and OS 36.0 months (95%-CI 22.1-49.9). Tumor pathology was prognostically significant for OS with LG-ESS being the most favorable (mean OS 150.3 months). In the multivariate analysis, patients over 52 years showed a four times higher risk for tumor recurrence (hazard ratio (HR) 4.4; 95%-CI 1.5-12.9). Progesterone receptor negativity was associated with a two times higher risk for death (HR 2.8; 95%-CI 1.0-7.5). For LMS patients age ≥ 52 years (p = 0.04), clear surgical margins (p = 0.01), FIGO stage (p = 0.01) and no application of chemotherapy (p = 0.02) were statistically significant factors for OS., Conclusion: Tumor histology, age at time of diagnosis and progesterone receptor status were prognostic factors for US. Unfavorable OS in LMS patients was associated with advanced FIGO stage, suboptimal cytoreduction and application of chemotherapy., (© 2022. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
22. Imaging of the Glucose-Dependent Insulinotropic Polypeptide Receptor Using a Novel Radiolabeled Peptide Rationally Designed Based on Endogenous GIP and Synthetic Exendin-4 Sequences.
- Author
-
Velikyan I, Bossart M, Haack T, Laitinen I, Estrada S, Johansson L, Pierrou S, Wagner M, and Eriksson O
- Abstract
Imaging and radiotherapy targeting the glucose-dependent insulinotropic polypeptide receptor (GIPR) could potentially benefit the management of neuroendocrine neoplasms (NENs), complementing clinically established radiopharmaceuticals. The aim of this study was to evaluate a GIPR-targeting positron emission tomography (PET) radioligand with receptor-specific binding, fast blood clearance, and low liver background uptake. The peptide DOTA-bioconjugate, C803-GIP, was developed based on the sequence of the endogenous GIP(1-30) and synthetic exendin-4 peptides with selective amino acid mutations to combine their specificity for the GIPR and in vivo stability, respectively. The
68 Ga-labeled bioconjugate was evaluated in vitro in terms of binding affinity, specificity, and internalization in HEK293 cells transfected with the human GIPR, GLP1, or GCG receptors and in sections of human insulinoma and NENs. In vivo binding specificity, biodistribution, and tissue background were investigated in mice bearing huGIPR-HEK293 xenografts and in a pig. Ex vivo organ distribution, pharmacokinetics, and dosimetry were studied in normal rats. [68 Ga]Ga-C803-GIP was stable and demonstrated a high affinity to the huGIPR-HEK293 cells. Binding specificity was demonstrated in vitro in frozen sections of NENs and huGIPR-HEK293 cells. No specific uptake was observed in the negative controls of huGLP1R and huGCGR cells. A novel rationally designed PET radioligand, [68 Ga]Ga-C803-GIP, demonstrated promising binding characteristics and specificity towards the GIPR.- Published
- 2022
- Full Text
- View/download PDF
23. Gender-related differences in career development among gynecologic oncology surgeons in Europe. European Network of Young Gynecologic Oncologists' Survey based data.
- Author
-
Nikolova T, Bossart M, Kacperczyk-Bartnik J, Razumova Z, Strojna A, Bizzarri N, Pletnev A, Gómez-Hidalgo NR, Theofanakis C, Lanner M, Selcuk I, Shushkevich A, Anca CR, Nikolova N, Concin N, and Zalewski K
- Abstract
Introduction: Gender-related differences in career development are well known issues in various professions. An international survey on gender-related differences was performed among young gynecologic oncology surgeons in Europe to identify potential gender inequalities in career development., Material and Methods: A survey on demographics, clinical and academic working environment, family/parenting, career development, salary and leadership was sent to all members of the European Network of Young Gynecologic Oncologists (ENYGO), which is a network within the European Society of Gynecologic Oncology (ESGO). Gynecologic oncology surgeons and obstetricians/gynecologists who actively work in this field in Europe were included in the study., Results: Responses were analyzed from 192 gynecologic oncology surgeons of whom 65.1% (125/192) were female (median age 37, IQR: 34 - 42) and 34.9% (67/192) were male (median age 38, IQR: 36 - 41). Male reported to perform a median of 15 and female a median of 10 operations per month (p = . 007). Among female, 24.8% had a leadership position vs. 44.8% among male, crude OR = 2.46, 95% CI 1.31-4.62, p< .01. When stratifying for age under 41 and having children, 36.7% of male and 5.6% of female had a leadership position, adjusted OR 10.8, 95% CI 3.28-35.64, p <.001. A significantly higher proportion of female compared to male believed they earned less than their gender counterparts at the same clinical position and with same qualifications (30.4% vs. 2.5%, p< .001). There was not a statistically significant gender difference in the academic qualification PhD degree or professorship ( p = .92 and p = .64, respectively). In the previous year, male published more peer-reviewed articles than female (median 3 vs. median 2; p = .017)., Conclusion: This first comprehensive survey on gender-differences in gynecologic oncology in Europe revealed that there are gender gaps concerning several aspects during the critical time of career development in the young generation of gynecologic oncology surgeons. These gender gaps are particularly reflected by a lower rate of female leadership positions. ENYGO and ESGO are dedicated to work on solution to overcome the identified obstacles and to support closing gender gaps., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Nikolova, Bossart, Kacperczyk-Bartnik, Razumova, Strojna, Bizzarri, Pletnev, Gómez-Hidalgo, Theofanakis, Lanner, Selcuk, Shushkevich, Anca, Nikolova, Concin and Zalewski.)
- Published
- 2022
- Full Text
- View/download PDF
24. Glucagonlike Peptide-1 Receptor Imaging in Individuals with Type 2 Diabetes.
- Author
-
Eriksson O, Velikyan I, Haack T, Bossart M, Laitinen I, Larsen PJ, Berglund JE, Antoni G, Johansson L, Pierrou S, Tillner J, and Wagner M
- Subjects
- Gallium Radioisotopes, Humans, Peptides chemistry, Positron Emission Tomography Computed Tomography, Positron-Emission Tomography methods, Reproducibility of Results, Diabetes Mellitus, Type 2 diagnostic imaging, Glucagon-Like Peptide-1 Receptor metabolism
- Abstract
The glucagonlike peptide-1 receptor (GLP1R) is a gut hormone receptor, intricately linked to regulation of blood glucose homeostasis via several mechanisms. It is an established and emergent drug target in metabolic disease. The PET radioligand
68 Ga-DO3A-VS-exendin4 (68 Ga-exendin4) has the potential to enable longitudinal studies of GLP1R in the human pancreas. Methods:68 Ga-exendin4 PET/CT examinations were performed on overweight-to-obese individuals with type 2 diabetes ( n = 13) as part of a larger target engagement study (NCT03350191). A scanning protocol was developed to optimize reproducibility (target amount of 0.5 MBq/kg [corresponding to peptide amount of <0.2 µg/kg], blood sampling, and tracer stability assessment). The pancreas and abdominal organs were segmented, and binding was correlated with clinical parameters. Results: Uptake of68 Ga-exendin4 in the pancreas, but not in other abdominal tissues, was high but variable between individuals. There was no evidence of self-blocking of GLP1R by the tracer in this protocol, despite the high potency of exendin4. The results showed that a full dynamic scan can be simplified to a short static scan, potentially increasing throughput and reducing patient discomfort. The68 Ga-exendin4 concentration in the pancreas (i.e., GLP1R density) correlated inversely with the age of the individual and tended to correlate positively with body mass index. However, the total GLP1R content in the pancreas did not. Conclusion: In summary, we present an optimized and simplified68 Ga-exendin4 scanning protocol to enable reproducible imaging of GLP1R in the pancreas.68 Ga-exendin4 PET may enable quantification of longitudinal changes in pancreatic GLP1R during the development of type 2 diabetes, as well as target engagement studies of novel glucagonlike peptide-1 agonists., (© 2022 by the Society of Nuclear Medicine and Molecular Imaging.)- Published
- 2022
- Full Text
- View/download PDF
25. New England Nursing Informatics Consortium and CIN: Computers, Informatics, Nursing Partner to Offer a Virtual Journal Club With Continuing Education!
- Author
-
Kennedy MK, Vrana-Bossart M, Henry A, Goldsmith DM, and Phillips A
- Subjects
- Computers, Education, Nursing, Continuing, Humans, New England, Education, Nursing, Nursing Informatics
- Published
- 2022
- Full Text
- View/download PDF
26. Effects on weight loss and glycemic control with SAR441255, a potent unimolecular peptide GLP-1/GIP/GCG receptor triagonist.
- Author
-
Bossart M, Wagner M, Elvert R, Evers A, Hübschle T, Kloeckener T, Lorenz K, Moessinger C, Eriksson O, Velikyan I, Pierrou S, Johansson L, Dietert G, Dietz-Baum Y, Kissner T, Nowotny I, Einig C, Jan C, Rharbaoui F, Gassenhuber J, Prochnow HP, Agueusop I, Porksen N, Smith WB, Nitsche A, and Konkar A
- Subjects
- Animals, Gastric Inhibitory Polypeptide, Glucagon-Like Peptide 1, Humans, Peptides pharmacology, Glucagon-Like Peptide-1 Receptor agonists, Glycemic Control, Incretins pharmacology, Receptors, Gastrointestinal Hormone agonists, Receptors, Glucagon agonists, Weight Loss drug effects
- Abstract
Unimolecular triple incretins, combining the activity of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon (GCG), have demonstrated reduction in body weight and improved glucose control in rodent models. We developed SAR441255, a synthetic peptide agonist of the GLP-1, GCG, and GIP receptors, structurally based on the exendin-4 sequence. SAR441255 displays high potency with balanced activation of all three target receptors. In animal models, metabolic outcomes were superior to results with a dual GLP-1/GCG receptor agonist. Preclinical in vivo positron emission tomography imaging demonstrated SAR441255 binding to GLP-1 and GCG receptors. In healthy subjects, SAR441255 improved glycemic control during a mixed-meal tolerance test and impacted biomarkers for GCG and GIP receptor activation. Single doses of SAR441255 were well tolerated. The results demonstrate that integrating GIP activity into dual GLP-1 and GCG receptor agonism provides improved effects on weight loss and glycemic control while buffering the diabetogenic risk of chronic GCG receptor agonism., Competing Interests: Declaration of interests M.B., M.W., R.E., A.E., T.H., T. Kloeckener, K.L., C.M., G.D., Y.D.-B., T. Kissner, I.N., C.E., C.J., F.R., J.G., H.-P.P., I.A., N.P., A.N., and A.K. were employees of Sanofi when the studies were conducted and may hold shares and/or stock options in the company. M.B., M.W., A.E., and K.L. are inventors on the patent application WO2018100135 containing SAR441255. O.E. and S.P. are employees of Antaros Medical AB, which received payment for the practical conduct of the PET study. Otherwise, they declare no competing interests. L.J. is co-founder, co-owner, and employee of Antaros Medical AB, which received payment for the practical conduct of the PET study. Otherwise, L.J. declares no competing interests. I.V. is an employee of Uppsala University Hospital, which received payment for the practical conduct of the PET study. I.V. declares no competing interests. W.B.S. was the principal investigator of the study conducted at the MDNOCCR Alliance for Multispecialty Research (AMR)/DBA NOCCR (New Orleans Center for Clinical Research), Knoxville, Tennessee, and received payment for the practical conduct of the study. No payment was received for the preparation of this manuscript. No other potential conflicts of interest relevant to this article were reported., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
27. The effect of fertility-sparing surgery on sexuality and global quality of life in women with malignant ovarian germ cell and sex cord stromal tumors: an analysis of the CORSETT database of the AGO study group.
- Author
-
Hasenburg A, Plett H, Krämer B, Braicu E, Czogalla B, Bossart M, Singer S, Mayr D, Staebler A, du Bois A, Kommoss S, Link T, Burges A, Heitz F, Keul J, Trillsch F, Harter P, Wimberger P, Buderath P, and Klar M
- Subjects
- Female, Germ Cells pathology, Humans, Neoplasm Staging, Prospective Studies, Quality of Life, Retrospective Studies, Sexual Behavior, Sexuality, Fertility Preservation, Ovarian Neoplasms pathology, Ovarian Neoplasms surgery, Sex Cord-Gonadal Stromal Tumors pathology, Sex Cord-Gonadal Stromal Tumors surgery
- Abstract
Purpose: Malignant ovarian germ cell (MOGCT) and sex cord stromal tumors (SCST) are ovarian neoplasms that affect disproportionally young women. Little is known about the impact of surgical and adjuvant management of these patient's sexual life. This study investigated the effect of fertility-sparing surgery on sexual activity and global quality of life (gQoL) in women with MOGCT and SCST., Methods: CORSETT was an observational, multicenter, mixed retrospective/prospective cohort study of the AGO study group. Women of any age who had been diagnosed with MOGCTs and SCSTs between 2001 and 2011 were asked to complete the Sexual Activity Questionnaire (SAQ) and the EORTC QLQ-C30., Results: In total, 355 patients were included. Of these, 152 patients with confirmed histological diagnosis had completed the questionnaires. A total of 106 patients were diagnosed with SCST and 46 with MOGCT. Totally, 83 women (55%) were sexually active. After fertility-sparing surgery, patients had a 2.6 fold higher probability for being sexually active than after non-fertility-conserving treatment (unadjusted odds ratio (OR) 2.6, p = 0.01). After adjustment for age, time since diagnosis, FIGO stage, histology and phase of disease, the OR dropped to 1.8 (p = 0.22). Of the sexually active patients, 35 (42%) reported high levels of discomfort during intercourse; 38% after fertility-sparing; and 58% after non-fertility-sparing surgery (adjusted OR 2.8, p = 0.18). Women with fertility-conserving treatment reported a significantly better global QoL (F
adj 2.1, 6.2 points difference, p = 0.03) but not more pleasure during intercourse than women without fertility-sparing surgery (Fadj 0.4, p = 0.52)., Conclusion: Fertility preserving approaches should be offered to every patient, when oncologically acceptable., (© 2021. The Author(s).)- Published
- 2021
- Full Text
- View/download PDF
28. Imaging of the Glucagon Receptor in Subjects with Type 2 Diabetes.
- Author
-
Eriksson O, Velikyan I, Haack T, Bossart M, Laitinen I, Larsen PJ, Berglund JE, Antoni G, Johansson L, Pierrou S, Tillner J, and Wagner M
- Subjects
- Adult, Body Weight, Female, Gallium Radioisotopes, Humans, Kidney metabolism, Male, Positron Emission Tomography Computed Tomography, Radiometry, Tissue Distribution, Diabetes Mellitus, Type 2 diagnostic imaging, Diabetes Mellitus, Type 2 metabolism, Receptors, Glucagon metabolism
- Abstract
Despite the importance of the glucagon receptor (GCGR) in disease and in pharmaceutical drug development, there is a lack of specific and sensitive biomarkers of its activation in humans. The PET radioligand
68 Ga-DO3A-VS-Tuna-2 (68 Ga-Tuna-2) was developed to yield a noninvasive imaging marker for GCGR target distribution and drug target engagement in humans. Methods: The biodistribution and dosimetry of68 Ga-Tuna-2 was assessed by PET/CT in 13 individuals with type 2 diabetes as part of a clinical study assessing the occupancy of the dual GCGR/glucagon like peptide-1 receptor agonist SAR425899. Binding of68 Ga-Tuna-2 in liver and reference tissues was evaluated and correlated to biometrics (e.g., weight or body mass index) or other biomarkers (e.g., plasma glucagon levels). Results:68 Ga-Tuna-2 binding was seen primarily in the liver, which is in line with the strong expression of GCGR on hepatocytes. The kidneys demonstrated high excretion-related retention, whereas all other tissue demonstrated rapid washout. The SUV55 min (SUV during the last 10-min time frame, 50-60 min after administration) uptake endpoint was sensitive to endogenous levels of glucagon.68 Ga-Tuna-2 exhibited a safe dosimetry profile and no adverse events after intravenous administration. Conclusion:68 Ga-Tuna-2 can be used for safe and accurate assessment of the GCGR in human. It may serve as an important tool in understanding the in vivo pharmacology of novel drugs engaging the GCGR., (© 2021 by the Society of Nuclear Medicine and Molecular Imaging.)- Published
- 2021
- Full Text
- View/download PDF
29. Drug Occupancy Assessment at the Glucose-Dependent Insulinotropic Polypeptide Receptor by Positron Emission Tomography.
- Author
-
Eriksson O, Velikyan I, Haack T, Bossart M, Evers A, Lorenz K, Laitinen I, Larsen PJ, Plettenburg O, Johansson L, Pierrou S, and Wagner M
- Subjects
- Animals, Female, Humans, Hypoglycemic Agents, Male, Radiochemistry, Rats, Signal Transduction physiology, Gastric Inhibitory Polypeptide metabolism, Glucose metabolism, Positron-Emission Tomography methods, Receptors, Gastrointestinal Hormone metabolism
- Abstract
Targeting of the glucose-dependent insulinotropic polypeptide receptor (GIPR) is an emerging strategy in antidiabetic drug development. The aim of this study was to develop a positron emission tomography (PET) radioligand for the GIPR to enable the assessment of target distribution and drug target engagement in vivo. The GIPR-selective peptide S02-GIP was radiolabeled with
68 Ga. The resulting PET tracer [68 Ga]S02-GIP-T4 was evaluated for affinity and specificity to human GIPR (huGIPR). The in vivo GIPR binding of [68 Ga]S02-GIP-T4 as well as the occupancy of a drug candidate with GIPR activity were assessed in nonhuman primates (NHPs) by PET. [68 Ga]S02-GIP-T4 bound with nanomolar affinity and high selectivity to huGIPR in overexpressing cells. In vivo, pancreatic binding in NHPs could be dose-dependently inhibited by coinjection of unlabeled S02-GIP-T4. Finally, subcutaneous pretreatment with a high dose of a drug candidate with GIPR activity led to a decreased pancreatic binding of [68 Ga]S02-GIP-T4, corresponding to a GIPR drug occupancy of almost 90%. [68 Ga]S02-GIP-T4 demonstrated a safe dosimetric profile, allowing for repeated studies in humans. In conclusion, [68 Ga]S02-GIP-T4 is a novel PET biomarker for safe, noninvasive, and quantitative assessment of GIPR target distribution and drug occupancy., (© 2021 by the American Diabetes Association.)- Published
- 2021
- Full Text
- View/download PDF
30. Revised FIGO Staging for Cervical Cancer - A New Role for MRI.
- Author
-
Merz J, Bossart M, Bamberg F, and Eisenblaetter M
- Subjects
- Cervix Uteri pathology, Female, Humans, Neoplasm Recurrence, Local pathology, Prognosis, Sensitivity and Specificity, Magnetic Resonance Imaging methods, Neoplasm Staging methods, Uterine Cervical Neoplasms pathology
- Abstract
Cervical cancer is still the fourth most common malignancy in women worldwide and has a high mortality rate. The prognosis as well as the therapy depends largely on the extent of the tumor at the time of initial diagnosis. This shows the importance of correct staging of cervical cancer. In order to promote a globally uniform approach, staging of cervical cancer in the past was based on widespread examinations such as exam under anesthesia, histology from cervical conization or biopsy, systematic lymphadenectomy, cystoscopy, proctoscopy, i. v.-pyelogram and chest X-ray. However, as the primary tumor stage was often underestimated, the 2018 revised FIGO classification now permits cross-sectional imaging techniques and pathological findings to be incorporated into disease staging or an already existing stage to be adapted based on radiological findings. Thanks to its excellent soft tissue contrast, magnetic resonance imaging (MRI) is the method of choice for local-regional staging of cervical cancer, evaluating the response to treatment, detecting tumor recurrence and for follow-up examinations. It is important that radiologists interpreting pelvic MRI in case of suspected cervical cancer are familiar with the current FIGO staging system. This is the only way to determine the tumor stage as precisely as possible and thus lay the foundation for the success of therapy for patients. The aim of this review is to present the changes of the revised FIGO classification as well as to show the importance of MRI as the method of choice for local-regional tumor staging as a complement to clinical examination. KEY POINTS:: · Cervical cancer is still the world's fourth most common female cancer and has a high mortality rate.. · The FIGO classification for staging cervical cancer in the past was based on clinical and widespread examinations.. · The primary tumor stage has often been underestimated with the FIGO staging system since 2018.. · Since 2018, cross-sectional imaging techniques have been incorporated into disease staging.. · MRI is the method of choice for local-regional tumor staging, evaluation of the response to treatment, detection of tumor recurrence and possible complications.. CITATION FORMAT: · Merz J, Bossart M, Bamberg F et al. Revised FIGO Staging for Cervical Cancer - A New Role for MRI. Fortschr Röntgenstr 2020; 192: 937 - 944., Competing Interests: The authors declare that they have no conflict of interest., (© Georg Thieme Verlag KG Stuttgart · New York.)
- Published
- 2020
- Full Text
- View/download PDF
31. LION-PAW (lymphadenectomy in ovarian neoplasm) sexual function assessment: a prospective sub-study of the LION trial.
- Author
-
Hasenburg A, Sehouli J, Lampe B, Reuss A, Schmalfeld B, Belau AK, Bossart M, Mahner S, Hillemanns P, Petry U, du Bois A, Herwig U, Hilpert F, Gropp-Meier M, Hanf V, Greimel E, Wagner U, and Harter P
- Subjects
- Adult, Aged, Female, Humans, Middle Aged, Prospective Studies, Sexual Behavior statistics & numerical data, Surveys and Questionnaires, Time Factors, Dyspareunia etiology, Lymph Node Excision adverse effects, Ovarian Neoplasms surgery
- Abstract
Background: There is limited information about the impact of radical surgery including pelvic and para-aortic lymphadenectomy and subsequent platinum-based chemotherapy on sexuality in patients with advanced ovarian cancer., Objective: To evaluate the impact of radical surgery including pelvic and para-aortic lymphadenectomy and subsequent platinum-based chemotherapy on sexuality in patients with advanced ovarian cancer as a sub-protocol of the prospectively randomized LION trial., Methods: The Sexual Activity Questionnaire was applied to assess sexual function according to its sub-scales activity, pleasure, and discomfort. The 'orgasm' sub-scale from the Female Sexual Function Index was also added. The questionnaire was administered in combination with the EORTC QLQ-C30 questionnaire at baseline prior surgery, after 6, 12, and 24 months. The primary endpoint was changes in sexual function., Results: Overall, 495 patients received the questionnaires. 254 (51%) responded at baseline. Of these, 55 (22%) patients were sexually active, 182 (72%) were sexually inactive, and for 17 (7%) patients' data were not available. There was a total of 55/495 (11%) patients at 6 months, 139 (28%) patients at 12 months, and 81 (16%) patients at 24 months. Median age was 60.5 years (range 21.4-75.8). At baseline, sexually active responders were significantly younger (median age 51.5 years,) than sexually inactive responders (median age 61.8 years) and tended to have a better performance status. Discomfort evaluated as dryness of the vagina and pain during sexual intercourse was significantly worse at 12 months than at baseline (p<0.001); however, the surgical variable, lymphadenectomy, did not have any impact on this. The orgasm sub-scale showed diverging results with a deterioration from baseline to 12 months in the lymphadenectomy group compared with the no-lymphadenectomy group (p=0.02)., Conclusion: The majority of patients were sexually inactive; however, in those who were sexually active, pain during intercourse was worse at 12 months. In addition, the orgasm sub-scale demonstrated worse results in patients who underwent complete lymphadenectomy. The study suggests that surgery in the retroperitoneal space may influence sexual function., Competing Interests: Competing interests: AH reports personal fees from Astra Zeneca, personal fees from MedConcept, personal fees from MedUpdate, personal fees from Pfizer, personal fees from Roche, personal fees from Streamedup!GmbH, personal fees from Pharma Mar, personal fees from Tesaro, outside the submitted work; BS reports grants and personal fees from Roche, grants and personal fees from AstraZeneca, grants and personal fees from Tesaro, personal fees from Clovis, personal fees from MSD, personal fees from Ethicon, outside the submitted work; SM reports personal fees from AbbVie, grants and personal fees from AstraZeneca, personal fees from Clovis, personal fees from GSK, grants and personal fees from Medac, personal fees from MSD, personal fees from Novartis, personal fees from OLYMPUS Europa, grants and personal fees from PharmaMar, grants and personal fees from Roche, personal fees from Sensor Kinesis, grants and personal fees from Tesaro, personal fees from Teva, outside the submitted work; AdB reports personal fees from Roche, personal fees from Clovis, personal fees from Astra Zeneca/MSD, personal fees from GSK/Tesaro, personal fees from BIOCAD, personal fees from Genmab/seattle genetics, personal fees from Pfizer, outside the submitted work; PH reports grants and personal fees from Astra Zeneca, grants and personal fees from Roche, personal fees from Sotio, grants and personal fees from Tesaro, personal fees from Stryker, personal fees from Zai Lab, personal fees from MSD, grants and personal fees from public funding (ASCO, DKH, DFG), personal fees from Clovis, personal fees from Immunogen, grants from GSK, grants from Boehringer Ingelheim, grants from Medac, grants from Genmab, outside the submitted work., (© IGCS and ESGO 2020. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2020
- Full Text
- View/download PDF
32. Incretin combination therapy for the treatment of non-alcoholic steatohepatitis.
- Author
-
Kannt A, Madsen AN, Kammermeier C, Elvert R, Klöckener T, Bossart M, Haack T, Evers A, Lorenz K, Hennerici W, Rocher C, Böcskei Z, Guillemot JC, Mikol V, Pattou F, Staels B, and Wagner M
- Subjects
- Animals, Glucagon-Like Peptide-1 Receptor, Mice, Mice, Inbred C57BL, Receptors, Glucagon, Incretins therapeutic use, Non-alcoholic Fatty Liver Disease drug therapy
- Abstract
Aims: To test specific mono-agonists to the glucagon-like peptide-1 receptor (GLP-1R), glucagon receptor (GCGR) and glucose-dependent insulinotropic peptide receptor (GIPR), individually and in combination, in a mouse model of diet-induced non-alcoholic steatohepatitis (NASH) and fibrosis in order to decipher the contribution of their activities and potential additive effects to improving systemic and hepatic metabolism., Materials and Methods: We induced NASH by pre-feeding C57BL/6J mice a diet rich in fat, fructose and cholesterol for 36 weeks. This was followed by 8 weeks of treatment with the receptor-specific agonists 1-GCG (20 μg/kg twice daily), 2-GLP1 (3 μg/kg twice daily) or 3-GIP (30 μg/kg twice daily), or the dual (1 + 2) or triple (1 + 2 + 3) combinations thereof. A dual GLP-1R/GCGR agonistic peptide, 4-dual-GLP1/GCGR (30 μg/kg twice daily), and liraglutide (100 μg/kg twice daily) were included as references., Results: Whereas low-dose 1-GCG or 3-GIP alone did not influence body weight, liver lipids and histology, their combination with 2-GLP1 provided additional weight loss, reduction in liver triglycerides and improvement in histological disease activity score. Notably, 4-dual-GLP-1R/GCGR and the triple combination of selective mono-agonists led to a significantly stronger reduction in the histological non-alcoholic fatty liver disease activity score compared to high-dose liraglutide, at the same extent of body weight loss., Conclusions: GCGR and GIPR agonism provide additional, body weight-independent improvements on top of GLP-1R agonism in a murine model of manifest NASH with fibrosis., (© 2020 John Wiley & Sons Ltd.)
- Published
- 2020
- Full Text
- View/download PDF
33. Automated GMP-Compliant Production of [ 68 Ga]Ga-DO3A-Tuna-2 for PET Microdosing Studies of the Glucagon Receptor in Humans.
- Author
-
Wagner M, Doverfjord JG, Tillner J, Antoni G, Haack T, Bossart M, Laitinen I, Johansson L, Pierrou S, Eriksson O, and Velikyan I
- Abstract
Introduction : [
68 Ga]Ga-DO3A-VS-Cys40 -Tuna-2 (previously published as [68 Ga]Ga-DO3A-VS-Cys40 -S01-GCG) has shown high-affinity specific binding to the glucagon receptor (GCGR) in vitro and in vivo in rats and non-human primates in our previous studies, confirming the suitability of the tracer for drug development applications in humans. The manufacturing process of [68 Ga]Ga-DO3A-VS-Cys40 -Tuna-2 was automated for clinical use to meet the radiation safety and good manufacturing practice (GMP) requirements. Methods: The automated synthesis platform (Modular-Lab PharmTrace, Eckert & Ziegler, Eurotope, Germany), disposable cassettes for68 Ga-labeling, and pharmaceutical-grade68 Ge/68 Ga generator (GalliaPharm® ) used in the study were purchased from Eckert & Ziegler. The parameters such as time, temperature, precursor concentration, radical scavenger, buffer concentration, and pH, as well as product purification step, were investigated and optimized. Process optimization was conducted with regard to product quality and quantity, as well as process reproducibility. The active pharmaceutical ingredient starting material DO3A-VS-Cys40 -Tuna-2 (GMP-grade) was provided by Sanofi Aventis. Results: The reproducible and GMP-compliant automated production of [68 Ga]Ga-DO3A-VS-Cys40 -Tuna-2 with on-line documentation was developed. The non-decay-corrected radiochemical yield was 45.2 ± 2.5% ( n = 3, process validation) at the end of the synthesis with a labeling synthesis duration of 38 min and a quality controlincluding release procedure of 20 min. The radiochemical purity of the product was 98.9 ± 0.6% ( n = 17) with the total amount of the peptide in the preparation of 48 ± 2 µg ( n = 3, process validation). Radionuclidic purity, sterility, endotoxin content, residual solvent content, and sterile filter integrity tests met the acceptance criteria. The product was stable at ambient temperature for at least 2 h. Conclusion: The fully automated GMP-compliant manufacturing process was developed and thoroughly validated. The resulting [68 Ga]Ga-DO3A-VS-Cys40 -Tuna-2 was used in a clinical study for accurate quantification of GCGR occupancy by a dual anti-diabetic drug in vivo in humans.- Published
- 2020
- Full Text
- View/download PDF
34. Assessment of glucagon receptor occupancy by Positron Emission Tomography in non-human primates.
- Author
-
Eriksson O, Velikyan I, Haack T, Bossart M, Evers A, Laitinen I, Larsen PJ, Plettenburg O, Takano A, Halldin C, Antoni G, Johansson L, Pierrou S, and Wagner M
- Subjects
- Animals, Female, Glucagon-Like Peptide-1 Receptor metabolism, Humans, Ligands, Liver diagnostic imaging, Liver metabolism, Macaca fascicularis, Male, Peptides metabolism, Positron Emission Tomography Computed Tomography, Protein Binding, Radiometry, Rats, Rats, Sprague-Dawley, Reproducibility of Results, Spleen diagnostic imaging, Biomarkers metabolism, Receptors, Glucagon metabolism
- Abstract
The glucagon receptor (GCGR) is an emerging target in anti-diabetic therapy. Reliable biomarkers for in vivo activity on the GCGR, in the setting of dual glucagon-like peptide 1/glucagon (GLP-1/GCG) receptor agonism, are currently unavailable. Here, we investigated [
68 Ga]Ga-DO3A-S01-GCG as a biomarker for GCGR occupancy in liver, the tissue with highest GCGR expression, in non-human primates (NHP) by PET. [68 Ga]Ga-DO3A-S01-GCG was evaluated by dynamic PET in NHPs by a dose escalation study design, where up to 67 µg/kg DO3A-S01-GCG peptide mass was co-injected. The test-retest reproducibility of [68 Ga]Ga-DO3A-S01-GCG binding in liver was evaluated. Furthermore, we investigated the effect of pre-treatment with acylated glucagon agonist 1-GCG on [68 Ga]Ga-DO3A-S01-GCG binding in liver. [68 Ga]Ga-DO3A-S01-GCG bound to liver in vivo in a dose-dependent manner. Negligible peptide mass effect was observed for DO3A-S01-GCG doses <0.2 µg/kg. In vivo Kd for [68 Ga]Ga-DO3A-S01-GCG corresponded to 0.7 µg/kg, which indicates high potency. The test-retest reproducibility for [68 Ga]Ga-DO3A-S01-GCG binding in liver was 5.7 ± 7.9%. Pre-treatment with 1-GCG, an acylated glucagon agonist, resulted in a GCGR occupancy of 61.5 ± 9.1% in liver. Predicted human radiation dosimetry would allow for repeated annual [68 Ga]Ga-DO3A-S01-GCG PET examinations. In summary, PET radioligand [68 Ga]Ga-DO3A-S01-GCG is a quantitative biomarker of in vivo GCGR occupancy.- Published
- 2019
- Full Text
- View/download PDF
35. The preprohormone expression profile of enteroendocrine cells following Roux-en-Y gastric bypass in rats.
- Author
-
Zhang C, Rigbolt K, Petersen SL, Biehl Rudkjær LC, Schwahn U, Fernandez-Cachon ML, Bossart M, Falkenhahn M, Theis S, Hübschle T, Schmidt T, Just Larsen P, Vrang N, and Jelsing J
- Subjects
- Animals, Cholecystokinin genetics, Cholecystokinin metabolism, Computational Biology, Gastric Inhibitory Polypeptide genetics, Gastric Inhibitory Polypeptide metabolism, Immunohistochemistry, In Situ Hybridization, Laser Capture Microdissection, Male, Mice, Obesity surgery, RNA, Messenger genetics, RNA, Messenger metabolism, Rats, Rats, Sprague-Dawley, Sequence Analysis, RNA, Somatostatin genetics, Somatostatin metabolism, Transcriptome genetics, Enteroendocrine Cells metabolism, Gastric Bypass, Obesity genetics, Obesity metabolism, Peptide Hormones genetics, Peptide Hormones metabolism, Protein Precursors genetics, Protein Precursors metabolism
- Abstract
Objective: Roux-en-Y gastric bypass (RYGB) leads to rapid remission of type 2 diabetes (T2D) and sustained body weight loss, but the underlying molecular mechanisms are still not fully understood. To further elucidate these mechanisms and identify potentially novel preprohormone encoding genes with anti-diabetic and/or anti-obesity properties, we performed a comprehensive analysis of gene expression changes in enteroendocrine cells after RYGB in diet-induced obese (DIO) rats., Methods: The mRNA expression profiles of enteroendocrine cell enriched samples were characterized at 9, 22 and 60 days after RYGB surgery in a DIO rat model. Enteroendocrine cells were identified by chromogranin A immunohistochemistry and isolated by laser capture microdissection (LCM) from five regions covering the full rostro-caudal extension of the gastrointestinal (GI) tract. RNA sequencing and bioinformatic analyses were subsequently applied to identify differentially expressed preprohormone encoding genes., Results: From the analysis of enteroendocrine cell mRNA expression profiles, a total of 54 preprohormones encoding genes were found to be differentially regulated at one or more time-points following RYGB. These included well-known RYGB associated preprohormone genes (e.g. Gcg, Cck, Gip, Pyy and Sct) and less characterized genes with putative metabolic effects (e.g. Nmu, Guca2a, Guca2b, Npw and Adm), but also 16 predicted novel preprohormone genes. Among the list of gene transcripts, Npw, Apln and Fam3d were further validated using in situ mRNA hybridization and corresponding peptides were characterized for acute effects on food intake and glucose tolerance in mice., Conclusion: We present a comprehensive mRNA expression profile of chromogranin A positive enteroendocrine cells following RYGB in rats. The data provides a region-specific characterization of all regulated preprohormone encoding genes in the rat GI tract including 16 not hitherto known. The comprehensive catalogue of preprohormone expression changes may support our understanding of hormone mediated effects of RYGB on diabetes remission and body weight reduction., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
36. Peptide Optimization at the Drug Discovery-Development Interface: Tailoring of Physicochemical Properties Toward Specific Formulation Requirements.
- Author
-
Evers A, Pfeiffer-Marek S, Bossart M, Heubel C, Stock U, Tiwari G, Gebauer B, Elshorst B, Pfenninger A, Lukasczyk U, Hessler G, Kamm W, and Wagner M
- Subjects
- Computer Simulation, Drug Stability, Excipients chemistry, Glucagon-Like Peptide 1 agonists, Hydrogen-Ion Concentration, Molecular Dynamics Simulation, Peptides pharmacology, Preservatives, Pharmaceutical chemistry, Receptors, Glucagon agonists, Drug Development methods, Drug Discovery methods, Peptides chemistry
- Abstract
Physicochemical properties of peptides need to be compatible with the manufacturing process and formulation requirements to ensure developability toward the commercial drug product. This aspect is often disregarded and only evaluated late in discovery, imposing a high risk for delays in development, increased costs, and finally for the project in general. Here, we report a case study of early physicochemical peptide characterization and optimization of dual glucagon-like peptide 1/glucagon receptor agonists toward specific formulation requirements. Aggregation issues which were observed at acidic pH in the presence of phenolic preservatives could be eliminated by modification of the peptide sequence, and chemical stability issues were significantly improved by addition of stabilizing formulation excipients. We describe structural, analytical, and biophysical characterization in different compositions to analyze the effect of pH and formulation excipients on physical and chemical stability. Molecular models have been generated to rationalize peptide stability behavior based on computed physicochemical descriptors and interactions with excipients. To conclude these studies, a general roadmap is proposed how to assess and optimize early physicochemical peptide properties in a sophisticated way by combining experimental and in silico profiling to provide stable peptide drugs under relevant formulation conditions at the end of discovery., (Copyright © 2019 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
37. First-in-class positron emission tomography tracer for the glucagon receptor.
- Author
-
Velikyan I, Haack T, Bossart M, Evers A, Laitinen I, Larsen P, Plettenburg O, Johansson L, Pierrou S, Wagner M, and Eriksson O
- Abstract
The glucagon receptor (GCGR) is emerging as an important target in anti-diabetic therapy, especially as part of the pharmacology of dual glucagon-like peptide-1/glucagon (GLP-1/GCG) receptor agonists. However, currently, there are no suitable biomarkers that reliably demonstrate GCG receptor target engagement., Methods: Two potent GCG receptor peptide agonists, S01-GCG and S02-GCG, were labeled with positron emission tomography (PET) radionuclide gallium-68. The GCG receptor binding affinity and specificity of the resulting radiopharmaceuticals [
68 Ga]Ga-DO3A-S01-GCG and [68 Ga]Ga-DO3A-S02-GCG were evaluated in HEK-293 cells overexpressing the human GCG receptor and on frozen hepatic sections from human, non-human primate, and rat. In in vivo biodistribution, binding specificity and dosimetry were assessed in rat., Results: [68 Ga]Ga-DO3A-S01-GCG in particular demonstrated GCG receptor-mediated binding in cells and liver tissue with affinity in the nanomolar range required for imaging. [68 Ga]Ga-DO3A-S01-GCG binding was not blocked by co-incubation of a GLP-1 agonist. In vivo binding in rat liver was GCG receptor specific with low non-specific binding throughout the body. Moreover, the extrapolated human effective doses, predicted from rat biodistribution data, allow for repeated PET imaging potentially also in combination with GLP-1R radiopharmaceuticals., Conclusion: [68 Ga]Ga-DO3A-S01-GCG thus constitutes a first-in-class PET tracer targeting the GCG receptor, with suitable properties for clinical development. This tool has potential to provide direct quantitative evidence of GCG receptor occupancy in humans.- Published
- 2019
- Full Text
- View/download PDF
38. A novel dual glucagon-like peptide and glucagon receptor agonist SAR425899: Results of randomized, placebo-controlled first-in-human and first-in-patient trials.
- Author
-
Tillner J, Posch MG, Wagner F, Teichert L, Hijazi Y, Einig C, Keil S, Haack T, Wagner M, Bossart M, and Larsen PJ
- Subjects
- Adolescent, Adult, Blood Glucose analysis, Blood Glucose drug effects, Body Weight drug effects, Diabetes Mellitus, Type 2 complications, Female, Humans, Lipids blood, Male, Middle Aged, Obesity complications, Placebos, Young Adult, Diabetes Mellitus, Type 2 drug therapy, Glucagon-Like Peptide-1 Receptor agonists, Hypoglycemic Agents adverse effects, Hypoglycemic Agents pharmacology, Hypoglycemic Agents therapeutic use, Receptors, Glucagon agonists
- Abstract
Aims: To evaluate the safety, pharmacokinetics and pharmacodynamics of SAR425899, a novel polypeptide, active as an agonist at both the glucagon-like peptide-1 receptor (GLP-1R) and the glucagon receptor (GCR), in healthy volunteers and in overweight/obese patients with type 2 diabetes (T2D)., Methods: Subcutaneous administrations of SAR425899 were tested in two randomized, placebo-controlled, double-blind clinical trials. In the first trial, healthy overweight volunteers (body mass index [BMI] 25-30 kg/m
2 ; n = 32) received single-ascending doses (0.01-0.1 mg) of SAR425899 or placebo. In the second, a multiple-ascending-dose trial (NCT02411825), healthy normal- to overweight volunteers (BMI 20-30 kg/m2 ; n = 40) and overweight/obese patients with T2D (BMI 28-42 kg/m2 ; n = 36) received daily doses of SAR425899 or placebo over 21 or 28 days, respectively., Results: The most frequently reported adverse events were gastrointestinal; gastrointestinal side effects were less pronounced in patients with T2D compared with healthy volunteers. SAR425899 significantly reduced levels of fasting plasma glucose (P < 0.05 vs. placebo) and glycated haemoglobin (P < 0.001 versus placebo) in patients with T2D. Additionally, SAR425899 led to reductions in body weight, with a maximal reduction of 5.32 kg in healthy volunteers and 5.46 kg in patients with T2D (P < 0.001 vs. placebo) at end of treatment., Conclusions: SAR425899 was well tolerated and led to favourable glycaemic effects in patients with T2D and weight reduction in both healthy volunteers and patients. Whether dual GLP-1R/GCR agonism represents a treatment method that is superior to pure GLP-1R agonists for obesity and diabetes treatment remains to be confirmed., (© 2018 John Wiley & Sons Ltd.)- Published
- 2019
- Full Text
- View/download PDF
39. Sexual activity and quality of life in patients after treatment for breast and ovarian cancer.
- Author
-
Mayer S, Iborra S, Grimm D, Steinsiek L, Mahner S, Bossart M, Woelber L, Voss PJ, Gitsch G, and Hasenburg A
- Subjects
- Adult, Aged, Breast Neoplasms therapy, Child, Preschool, Female, Health Status, Humans, Infant, Middle Aged, Orgasm, Ovarian Neoplasms therapy, Retrospective Studies, Sexual Dysfunction, Physiological etiology, Surveys and Questionnaires, Breast Neoplasms psychology, Cancer Survivors psychology, Ovarian Neoplasms psychology, Quality of Life psychology, Sexual Behavior psychology
- Abstract
Objective: Sexual activity (SA) and functioning (SF) are important factors influencing quality of life (QoL). Anticancer treatment can cause or promote sexual dysfunctions. In this study we analyzed the SA, SF and QoL in patients after completion of treatment for breast cancer (BC) and ovarian cancer (OC)., Methods: In this retrospective multicenter study 396 BC patients and 93 OC patients aged between 18 and 70 years were surveyed at least 24 months after cancer diagnosis and compared to 60 healthy women. Data were collected through validated questionnaires (Sexual Activity Questionnaire, Female Sexual Function Index-d, EORTC Quality of Life Questionnaire-C30)., Results: 45.9% of BC patients and 56.5% of OC patients reported SA. SF and well-being of sexually active BC patients were not influenced by the type and radicality of surgery or the administration of chemotherapy. Patients who received antihormonal therapy at the time of evaluation showed a lower frequency of SA (p = 0.007), less satisfaction (p = 0.003) and more discomfort during SA (p = < 0.001) compared to healthy controls but no differences in experiencing orgasms, health status, QoL and global health status. In contrast, BC patients without antihormonal therapy showed only a higher discomfort score (p = 0.028) than healthy controls and estimated their health status and QoL significantly better than patients who received antihormonal therapy (p = 0006). In general, SA was associated with a better health status (p = 0.007), a better QoL (p = 0.004) and a better global health status (p = 0.004) in BC patients. Sexually active OC patients showed no significant differences in SF, QoL and health status compared to healthy controls., Conclusions: Compared to healthy controls BC patients showed limitations in SF with a lower SA rate and more discomfort. Antihormonal therapy was an important factor influencing SF and well-being. Breast and OC survivors reported good physical and psychical health without differences in QoL and health status compared to controls. This might be explained by a change of perspective on life difficulties and altered priorities through a life threatening disease.
- Published
- 2019
- Full Text
- View/download PDF
40. Team Players or Opponents: Coadministration of Selective Glucagon and GLP-1 Receptor Agonists in Obese Diabetic Monkeys.
- Author
-
Elvert R, Bossart M, Herling AW, Weiss T, Zhang B, Kannt A, Wagner M, Haack T, Evers A, Dudda A, Keil S, Lorenz M, Lorenz K, Riz M, Hennerici W, and Larsen PJ
- Subjects
- Animals, Bariatric Surgery, Blood Glucose metabolism, Diabetes Mellitus metabolism, Diabetes Mellitus, Type 2 surgery, Drug Therapy, Combination, Energy Metabolism drug effects, Macaca fascicularis, Mice, Obesity surgery, Blood Glucose drug effects, Body Weight drug effects, Diabetes Mellitus, Type 2 metabolism, Eating drug effects, Glucagon-Like Peptide-1 Receptor agonists, Obesity metabolism, Receptors, Glucagon agonists
- Abstract
We assessed the therapeutic contribution of the individual components of glucagon-like peptide-1 receptor (GLP-1R) and glucagon receptor (GCGR) agonists alone and in combination upon energy homeostasis and glycemic control in diet-induced obese, diabetic nonhuman primates. The pharmacological active dose ranges of selective agonists were established through a dose-finding study, followed by a 6-week chronic study. Repeated subcutaneous administration of a selective GCGR agonist (30 µg/kg once daily) did not affect food intake or body weight, whereas the selective GLP-1R agonist (3 µg/kg once daily) alone decreased energy intake by 18% and body weight by 3.8% ± 0.9%. Combination of both agonists reduced significantly cumulative food intake by 27% and body weight by 6.6% ± 0.9%. Fasting plasma glucose (FPG) was improved by GLP-1R agonist (baseline vs end of study, 176.7 ± 34.0 vs 115.9 ± 16.1 mg/dL). In contrast, groups exposed to GCGR agonist experienced nonsignificant elevations of FPG. More accurate assessment of therapeutic interventions on glucose homeostasis was tested by an IV glucose tolerance test. Glucose excursion was significantly elevated by chronic GCGR agonist administration, whereas it was significantly decreased in GLP-1R agonist-treated monkeys. In the combination group, a nonsignificant increase of glucose excursion was seen, concomitantly with significantly increased insulin secretion. We conclude that chronic glucagon agonism does not affect energy homeostasis in nonhuman primates. In combination with GLP-1R agonism, glucagon agonism synergistically enhances negative energy balance with resulting larger body weight loss. However, adding GCGR to GLP-1R agonism diminishes glycemic control in diabetic monkeys. Therefore, long-term therapeutic implications of using GLP-1R/GCGR coagonists for weight management in diabetes warrants further scrutiny.
- Published
- 2018
- Full Text
- View/download PDF
41. Running on mixed fuel-dual agonistic approach of GLP-1 and GCG receptors leads to beneficial impact on body weight and blood glucose control: A comparative study between mice and non-human primates.
- Author
-
Elvert R, Herling AW, Bossart M, Weiss T, Zhang B, Wenski P, Wandschneider J, Kleutsch S, Butty U, Kannt A, Wagner M, Haack T, Evers A, Dudda A, Lorenz M, Keil S, and Larsen PJ
- Subjects
- Animals, Animals, Outbred Strains, Appetite Depressants administration & dosage, Appetite Depressants adverse effects, Body Weight drug effects, Diabetes Mellitus, Type 2 blood, Diabetes Mellitus, Type 2 metabolism, Diet, High-Fat adverse effects, Dose-Response Relationship, Drug, Drug Therapy, Combination adverse effects, Energy Intake drug effects, Energy Metabolism drug effects, Female, Glucagon-Like Peptide-1 Receptor genetics, Glucagon-Like Peptide-1 Receptor metabolism, Hypoglycemic Agents administration & dosage, Hypoglycemic Agents adverse effects, Insulin Secretion drug effects, Macaca fascicularis, Male, Mice, Inbred C57BL, Mice, Knockout, Obesity blood, Obesity etiology, Obesity metabolism, Random Allocation, Receptors, Glucagon metabolism, Appetite Depressants therapeutic use, Diabetes Mellitus, Type 2 drug therapy, Glucagon-Like Peptide-1 Receptor agonists, Hyperglycemia prevention & control, Hypoglycemic Agents therapeutic use, Obesity drug therapy, Receptors, Glucagon agonists
- Abstract
Aim: We performed acute and chronic studies in healthy and diet-induced obese animals using mouse-specific or monkey-specific dual GLP-1R/GCGR agonists to investigate their effects on food intake, body weight, blood glucose control and insulin secretion. The selective GLP-1R agonist liraglutide was used as comparator., Methods: The mouse-specific dual agonist and liraglutide were tested in lean wild type, GLP-1R knockout and diet-induced obese mice at different doses. A chronic study was performed in DIO mice to investigate the effect on body weight, food consumption and total energy expenditure (TEE) in obese and diabetic monkeys with a focus on body weight and energy intake., Results: The mouse-specific dual agonist and liraglutide similarly affected glycaemic control. A higher loss in body weight was measured in dual agonist-treated obese mice. The dual agonist significantly enhanced plasma glucose excursion in overnight fed GLP-1R
-/- mice, probably reflecting a potent GCGR agonist activity. It increased TEE and enhanced fat and carbohydrate oxidation, while liraglutide produced no effect on TEE. In obese and diabetic monkeys, treatment with the monkey-specific dual agonist reduced total energy intake to 60%-70% of baseline TEI during chronic treatment. A decrease in body weight and significant improvement in glucose tolerance was observed., Conclusions: In DIO mice and non-human primates, dual agonists elicited robust glycaemic control, similar to the marketed GLP-1R agonist, while eliciting greater effects on body weight. Results from DIO mice suggest that the increase in TEE is caused not only by increased fat oxidation but also by an increase in carbohydrate oxidation., (© 2018 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.)- Published
- 2018
- Full Text
- View/download PDF
42. Dual Glucagon-like Peptide 1 (GLP-1)/Glucagon Receptor Agonists Specifically Optimized for Multidose Formulations.
- Author
-
Evers A, Bossart M, Pfeiffer-Marek S, Elvert R, Schreuder H, Kurz M, Stengelin S, Lorenz M, Herling A, Konkar A, Lukasczyk U, Pfenninger A, Lorenz K, Haack T, Kadereit D, and Wagner M
- Subjects
- Dose-Response Relationship, Drug, Drug Compounding, Extracellular Space metabolism, Glucagon-Like Peptide-1 Receptor chemistry, HEK293 Cells, Humans, Models, Molecular, Protein Domains, Receptors, Glucagon chemistry, Solubility, Structure-Activity Relationship, Drug Discovery, Glucagon-Like Peptide-1 Receptor agonists, Receptors, Glucagon agonists
- Abstract
Novel peptidic dual agonists of the glucagon-like peptide 1 (GLP-1) and glucagon receptor are reported to have enhanced efficacy over pure GLP-1 receptor agonists with regard to treatment of obesity and diabetes. We describe novel exendin-4 based dual agonists designed with an activity ratio favoring the GLP-1 versus the glucagon receptor. As result of an iterative optimization procedure that included molecular modeling, structural biological studies (X-ray, NMR), peptide design and synthesis, experimental activity, and solubility profiling, a candidate molecule was identified. Novel SAR points are reported that allowed us to fine-tune the desired receptor activity ratio and increased solubility in the presence of antimicrobial preservatives, findings that can be of general applicability for any peptide discovery project. The peptide was evaluated in chronic in vivo studies in obese diabetic monkeys as translational model for the human situation and demonstrated favorable blood glucose and body weight lowering effects.
- Published
- 2018
- Full Text
- View/download PDF
43. Validity Parameters of the Human Papillomavirus Detection Test Hybrid Capture 2 With and Without Cytology After Laser Destruction and Large Loop Excision of the Transformation Zone Treatment of High-Grade Cervical Intraepithelial Neoplasia Lesions.
- Author
-
Hansen J, Waibel J, Timme S, Gitsch G, Bossart M, Oehler MK, and Klar M
- Subjects
- Adult, Female, Follow-Up Studies, Humans, Middle Aged, Predictive Value of Tests, Sensitivity and Specificity, Young Adult, Uterine Cervical Dysplasia surgery, Histocytochemistry methods, Molecular Diagnostic Techniques methods, Papillomaviridae isolation & purification, Uterine Cervical Dysplasia diagnosis, Uterine Cervical Dysplasia pathology
- Abstract
Objective: The aim of this study was to calculate the validity parameters of the Digene Hybrid Capture 2 (HC2) high-risk human papillomavirus DNA test with and without cytology in the follow-up examinations after laser treatment of the transformation zone or large loop excision of the transformation zone (LLETZ) for cervical intraepithelial neoplasia (CIN)., Methods: We performed a standardized follow-up examination in 113 postlaser and 153 post-LLETZ patients in our colposcopy clinic. Routine cytology, HC2 tests, and colposcopically-guided cervical biopsies were performed and sensitivity, specificity, and positive and negative predictive values were calculated using the histological cervical biopsy result as the criterion standard., Results: After a median follow-up time of 25.5 months, the overall posttreatment recurrence/persistence rate of CIN 2 or higher (CIN 2+) was 24% after laser and 12.4% after Post-LLETZ treatment. Hybrid Capture 2 alone had a sensitivity/NPV of 70/88% in post-laser and 70/93% in post-LLETZ patients. Cytology alone had a sensitivity/NPV for CIN 2+ of 48/84% in post-laser and 58/91% in post-LLETZ patients. Combined testing of HC2 with cytology had a sensitivity/NPV of 81/92% in postlaser and 88/95% in post-LLETZ patients., Discussion: In this test of cure study, combined testing of cytology with HC2 resulted in a high sensitivity and NPV. Hybrid Capture 2 and cytology-negative women may safely return to routine recall. Cytology alone is not an adequate follow-up strategy in postlaser patients.
- Published
- 2017
- Full Text
- View/download PDF
44. Correction to Design of Novel Exendin-Based Dual Glucagon-like Peptide 1 (GLP-1)/Glucagon Receptor Agonist.
- Author
-
Evers A, Haack T, Lorenz M, Bossart M, Elvert R, Henkel B, Stengelin S, Kurz M, Glien M, Dudda A, Lorenz K, Kadereit D, and Wagner M
- Published
- 2017
- Full Text
- View/download PDF
45. Design of Novel Exendin-Based Dual Glucagon-like Peptide 1 (GLP-1)/Glucagon Receptor Agonists.
- Author
-
Evers A, Haack T, Lorenz M, Bossart M, Elvert R, Henkel B, Stengelin S, Kurz M, Glien M, Dudda A, Lorenz K, Kadereit D, and Wagner M
- Subjects
- Amino Acid Sequence, Animals, Blood Glucose analysis, Blood Glucose metabolism, Body Weight drug effects, Exenatide, Female, Glucagon metabolism, Glucagon-Like Peptide 1 chemistry, Glucagon-Like Peptide 1 metabolism, Glucagon-Like Peptide-1 Receptor chemistry, Glucagon-Like Peptide-1 Receptor metabolism, Hypoglycemic Agents blood, Hypoglycemic Agents chemistry, Hypoglycemic Agents pharmacology, Mice, Inbred C57BL, Mice, Obese, Molecular Docking Simulation, Obesity drug therapy, Obesity metabolism, Peptides blood, Structure-Activity Relationship, Swine, Venoms blood, Drug Design, Glucagon-Like Peptide 1 agonists, Glucagon-Like Peptide-1 Receptor agonists, Peptides chemistry, Peptides pharmacology, Venoms chemistry, Venoms pharmacology
- Abstract
Dual activation of the glucagon-like peptide 1 (GLP-1) and glucagon receptor has the potential to lead to a novel therapy principle for the treatment of diabesity. Here, we report a series of novel peptides with dual activity on these receptors that were discovered by rational design. On the basis of sequence analysis and structure-based design, structural elements of glucagon were engineered into the selective GLP-1 receptor agonist exendin-4, resulting in hybrid peptides with potent dual GLP-1/glucagon receptor activity. Detailed structure-activity relationship data are shown. Further modifications with unnatural and modified amino acids resulted in novel metabolically stable peptides that demonstrated a significant dose-dependent decrease in blood glucose in chronic studies in diabetic db/db mice and reduced body weight in diet-induced obese (DIO) mice. Structural analysis by NMR spectroscopy confirmed that the peptides maintain an exendin-4-like structure with its characteristic tryptophan-cage fold motif that is responsible for favorable chemical and physical stability.
- Published
- 2017
- Full Text
- View/download PDF
46. Robotic and Advanced Laparoscopic Surgical Training in European Gynecological Oncology Trainees.
- Author
-
Gan C, Bossart M, Piek J, Halaska M, Haidopoulos D, Zapardiel I, Grabowski JP, Kesic V, Kimmig R, Cibula D, Lambaudie E, Verheijen R, and Manchanda R
- Subjects
- Adult, Female, Humans, Male, Prospective Studies, Gynecologic Surgical Procedures education, Laparoscopy education, Robotic Surgical Procedures education, Surgical Oncology education
- Abstract
Introduction: Advanced minimal access surgical training is an important component of training in gynecological oncology (GO). Europe-wide data on this topic are lacking. We present data on availability and trainee experience of advanced laparoscopic surgical (ALS) and robotic surgical (RS) training in GO across Europe., Method: A prospective web-based anonymized survey of European GO trainees was sent to the European Network of Young Gynaecological Oncologists members/trainees. It included sociodemographic information and specific questions pertaining to training experience or satisfaction in laparoscopic and robotic surgery. χ test was used for evaluating categorical variables and Mann-Whitney/Kruskal-Wallis (nonparametric) tests for continuous variables between 2 and more independent groups., Results: A total of 113 GO trainees from 29 countries responded. The mean (standard deviation) age was 35.2 (6.1) years, 59.3% were men, 40.7% were women, and 46% were in accredited training posts. The ALS and RS training was offered in only 43% and 23% of institutes respectively, and 54% and 23% of trainees had undergone some form of formal or informal training in ALS and RS respectively. A total of 62.4% felt that RS should be a formal component of GO training programs. A total of 61% and 35% planned to go outside their institute for ALS or RS training respectively. Trainees rating (1-5 scale) of their open surgery and ALS or RS skills (3.3/2.6/1.9) and training experience (3.5/2.8/2.1), respectively, were higher for open surgery than ALS or RS (P < 0.0005). Accredited posts were more likely than nonaccredited posts to offer ALS training (60%/31%, P = 0.002), formal training schedules (27.9%/4.4%, P = 0.003), and use of logbooks (46%/23%, P = 0.035)., Conclusions: Training and experience in ALS and RS are poorly rated by GO trainees across Europe, and only few centers offer this. There is an urgent need to expand and harmonize training opportunities for ALS and RS. Most trainees want RS included as a formal component of their training.
- Published
- 2017
- Full Text
- View/download PDF
47. The work place educational climate in gynecological oncology fellowships across Europe: the impact of accreditation.
- Author
-
Piek J, Bossart M, Boor K, Halaska M, Haidopoulos D, Zapardiel I, Grabowski J, Kesic V, Cibula D, Colombo N, Verheijen R, and Manchanda R
- Subjects
- Adult, Education, Medical, Continuing, Europe, Female, Follow-Up Studies, Humans, Male, Surveys and Questionnaires, Workplace, Accreditation, Fellowships and Scholarships, Gynecology education, Internship and Residency, Medical Oncology education, Students, Medical psychology
- Abstract
Background: A good educational climate/environment in the workplace is essential for developing high-quality medical (sub)specialists. These data are lacking for gynecological oncology training., Objective: This study aims to evaluate the educational climate in gynecological oncology training throughout Europe and the factors affecting it., Methods: A Web-based anonymous survey sent to ENYGO (European Network of Young Gynecological Oncologists) members/trainees to assess gynecological oncology training. This included sociodemographic information, details regarding training posts, and a 50-item validated Dutch Residency Educational Climate Test (D-RECT) questionnaire with 11 subscales (1-5 Likert scale) to assess the educational climate. The χ test was used for evaluating categorical variables, and the Mann-Whitney U (nonparametric) test was used for continuous variables between 2 independent groups. Cronbach α assessed the questionnaire reliability. Multivariable linear regression assessed the effect of variables on D-RECT outcome subscales., Results: One hundred nineteen gynecological oncological fellows responded. The D-RECT questionnaire was extremely reliable for assessing the educational environment in gynecological oncology (subscales' Cronbach α, 0.82-0.96). Overall, trainees do not seem to receive adequate/effective constructive feedback during training. The overall educational climate (supervision, coaching/assessment, feedback, teamwork, interconsultant relationships, formal education, role of the tutor, patient handover, and overall consultant's attitude) was significantly better (P = 0.001) in centers providing accredited training in comparison with centers without such accreditation. Multivariable regression indicated the main factors independently associated with a better educational climate were presence of an accredited training post and total years of training., Conclusions: This study emphasizes the need for better feedback mechanisms and the importance of accreditation of centers for training in gynecological oncology to ensure training within higher quality clinical learning climates.
- Published
- 2015
- Full Text
- View/download PDF
48. Index-matched IWKB method for the measurement of spatially varying refractive index profiles within thin-film photovoltaics.
- Author
-
Pang YT, Bossart M, and Eisaman MD
- Abstract
In many thin-film photovoltaic devices, the photoactive layer has a spatially varying refractive index in the substrate-normal direction, but measurement of this variation with high spatial resolution is difficult due to the thinness of these layers (typically 200 nm for organic photovoltaics). We demonstrate a new method for reconstructing the depth-dependent refractive-index profile with high spatial resolution (~10 nm at a wavelength of 500 nm) in thin (200 nm) photoactive layers by depositing a relatively thick index-matched layer (1-10 μm) adjacent to the photoactive layer and applying the Inverse Wentzel-Kramers-Brillouin (IWKB) method. This novel technique, which we refer to as index-matched IWKB (IM-IWKB), is applicable to any thin film, including the photoactive layers of a broad range of thin-film photovoltaics.
- Published
- 2014
- Full Text
- View/download PDF
49. Effect of prior chemotherapy regimens on the efficacy of endocrine therapy within a German cohort of the TEAM trial.
- Author
-
Bossart M, Hadji P, Klar M, Kieback DG, and Hasenburg A
- Subjects
- Androstadienes administration & dosage, Breast Neoplasms pathology, Chemotherapy, Adjuvant, Cohort Studies, Disease-Free Survival, Female, Humans, Middle Aged, Neoplasm Grading, Neoplasm Staging, Postmenopause, Retrospective Studies, Survival Rate, Tamoxifen administration & dosage, Androstadienes therapeutic use, Antineoplastic Agents, Hormonal therapeutic use, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Aromatase Inhibitors therapeutic use, Breast Neoplasms drug therapy
- Abstract
Purpose: Prior chemotherapy may affect the efficacy of endocrine therapy., Methods: The tamoxifen exemestane adjuvant multinational (TEAM) trial compared 5 years of adjuvant exemestane with the sequence of tamoxifen followed by exemestane in postmenopausal women with hormone-receptor-positive breast cancer. A total of 1,502 patients were enrolled in Germany (739 received tamoxifen followed by exemestan and 610 exemestan alone). A retrospective analysis of the German cohort of TEAM was conducted to determine whether prior chemotherapy affected clinical outcome of endocrine therapy., Results: Overall survival, disease-free survival and distant recurrence were similar between patients who received sequential therapy and those who received exemestane monotherapy, irrespective of prior chemotherapy. Overall survival was not significantly different between patients who had received prior chemotherapy and those who had not (P = 0.2836). Disease-free survival and distant recurrence were significantly better in patients who had not received prior chemotherapy versus those who had (P = 0.0308 and P = 0.0001). In patients receiving sequential therapy, there were no significant differences in overall survival according to prior chemotherapy use (P = 0.1812). However, disease-free survival and distant recurrence were significantly different dependent on prior chemotherapy (P = 0.0143 and P = 0.0053)., Conclusion: In conclusion, there was no difference in overall survival between breast cancer patients who did receive prior chemotherapy before endocrine therapy and those who had not. Patients who had not received prior chemotherapy had significantly improved disease-free survival and less distant recurrence versus those who had received chemotherapy.
- Published
- 2014
- Full Text
- View/download PDF
50. The need for more workshops in laparoscopic surgery and surgical anatomy for European gynaecological oncology trainees: a survey by the European Network of Young Gynaecological Oncologists.
- Author
-
Manchanda R, Halaska MJ, Piek JM, Grabowski JP, Haidopoulos D, Zapardiel I, Gultekin M, Vranes B, Dallaku K, and Bossart M
- Subjects
- Clinical Competence, Data Collection, Humans, Education, Medical, Continuing, Gynecologic Surgical Procedures education, Gynecology education, Laparoscopy education, Medical Oncology education, Needs Assessment
- Abstract
Objective: The objective of this study was to highlight the relative preference of European gynecologic oncology trainees for workshops that could support and supplement their training needs., Methods: A Web-based survey was sent to 900 trainees on the European Network of Young Gynaecological Oncologists database in November 2011. Respondents were asked to rate a 13-item questionnaire (using a 1- to 5-point Likert scale) on workshop topics they felt would most benefit their training requirements. Free text space for additional topics was also provided. Descriptive analysis was used to describe the mean scores reported for different items. A complete linkage hierarchical cluster analysis with Dendron plot was used to assess any clustering of data, and Cronbach α was used to assess the internal reliability of the questionnaire., Results: One hundred ninety trainees from 37 countries responded to the survey, giving a 21% response rate. The 3 most important topics reported were laparoscopic surgery; surgical anatomy, and imaging techniques in gynecologic oncology. The Dendron plot indicated 4 different clusters of workshops (research related skills, supportive ancillary skills, related nonsurgical subspecialties, and core surgical skills) reflecting different competencies trainees need to meet. There was no significant association between individual country of training and workshop preference. The mean duration of the workshop preferred by 71% of respondents was 2 days. Cronbach α of the 13-item questionnaire was 0.78, which suggests good internal consistency/reliability., Conclusions: This report for the first time highlights the relative importance and significance European trainees attach to some of their training needs in gynecologic oncology. Laparoscopic surgery, surgical anatomy, and imaging appear to be the 3 areas of greatest need. The European Society of Gynaecological Oncology, other national specialist societies, and institutions should direct additional training efforts at these areas.
- Published
- 2013
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.