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Geyer J, Barschkett M, Haan P, Hammerschmid A. The effects of an increase in the retirement age on health care costs: evidence from administrative data. Eur J Health Econ 2023; 24:1101-1120. [PMID: 36274115 PMCID: PMC10406678 DOI: 10.1007/s10198-022-01535-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
In this paper, we use unique health record data that cover outpatient care and the associated costs to quantify the health care costs of a sizable increase in the retirement age in Germany. For the identification, we exploit a sizable cohort-specific pension reform which abolished an early retirement program for all women born after 1951. Our results show that health care costs significantly increase by about 2.9% in the age group directly affected by the increase in the retirement age (women aged 60-62). We further show that the cost increase is mainly driven by the following specialist groups: Ophthalmologists, general practitioners (GPs), neurology, orthopedics, and radiology. While the effects are significant and meaningful on the individual level, we show that the increase in health care costs is modest relative to the positive fiscal effects of the pension reform. Specifically, we estimate an aggregate increase in the health costs of about 7.7 million euro for women born in 1952 aged 60-62 which amounts to less than 2% of the overall positive fiscal effects of the pension reform.
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Affiliation(s)
- Johannes Geyer
- Department of Public Economics, DIW Berlin, Mohrenstr. 58, 10117 Berlin, Germany
| | - Mara Barschkett
- Department of Public Economics, DIW Berlin, Mohrenstr. 58, 10117 Berlin, Germany
- Berlin School of Economics, Berlin, Germany
| | - Peter Haan
- Department of Public Economics, DIW Berlin, Mohrenstr. 58, 10117 Berlin, Germany
- School of Business and Economics, FU Berlin, 14195 Berlin, Germany
| | - Anna Hammerschmid
- Department of Public Economics, DIW Berlin, Mohrenstr. 58, 10117 Berlin, Germany
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Harris Z, Geyer J, Sun Y, Hu B, Stanley G, Rajagopalan G, Robinson J, Koff J. 514: Novel zinc porphyrin antibiotic shows activity against Pseudomonas in vivo. J Cyst Fibros 2021. [DOI: 10.1016/s1569-1993(21)01938-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Geyer J. Notes About Comparing Long-term Care Expenditures Across Countries Comment on "Financing Long-term Care: Lessons From Japan". Int J Health Policy Manag 2019; 9:80-82. [PMID: 32124592 PMCID: PMC7054649 DOI: 10.15171/ijhpm.2019.87] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 10/07/2019] [Indexed: 11/09/2022] Open
Abstract
The comparison of long-term care (LTC) expenditures is a difficult task. National LTC systems differ widely in terms of eligibility criteria, level of benefits, institutional variety and regional heterogeneity. In this commentary I will first give some general remarks on cross country comparisons. Then I discuss the role of the informal sector which is the most important pillar of all LTC systems. I conclude with some background on current developments in Germany. Different from Japan Germany is extending its LTC insurance instead of containing costs.
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Zeitz JO, Weber A, Most E, Windisch W, Bolduan C, Geyer J, Romberg FJ, Koch C, Eder K. Effects of supplementing rumen-protected niacin on fiber composition and metabolism of skeletal muscle in dairy cows during early lactation. J Dairy Sci 2018; 101:8004-8020. [PMID: 29960772 DOI: 10.3168/jds.2018-14490] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/13/2018] [Indexed: 01/01/2023]
Abstract
Nicotinic acid (NA) has been shown to induce muscle fiber switching toward oxidative type I fibers and a muscle metabolic phenotype that favors fatty acid (FA) utilization in growing rats, pigs, and lambs. The hypothesis of the present study was that supplementation of NA in cows during the periparturient phase also induces muscle fiber switching from type II to type I fibers in skeletal muscle and increases the capacity of the muscle to use free FA, which may help to reduce nonesterified fatty acid (NEFA) flow to the liver, liver triglyceride (TG) accumulation, and ketogenesis. Thirty multiparous Holstein dairy cows were allocated to 2 groups and fed a total mixed ration without (control group) or with ∼55 g of rumen-protected NA per cow per day (NA group) from 21 d before expected calving until 3 wk postpartum (p.p.). Blood samples were collected on d -21, -14, -7, 7, 14, 21, 35, and 63 relative to parturition for analysis of TG, NEFA, and β-hydroxybutyrate. Muscle and liver biopsies were collected on d 7 and 21 for gene expression analysis and to determine muscle fiber composition in the musculus semitendinosus, semimembranosus, and longissimus lumborum by immunohistochemistry, and liver TG concentrations. Supplementation of NA did not affect the proportions of type I (oxidative) or the type II:type I ratio in the 3 muscles considered. A slight shift from glycolytic IIx fibers toward oxidative-glycolytic fast-twitch IIa fibers was found in the semitendinosus, and a tendency in the longissimus lumborum, but not in the semimembranosus. The transcript levels of the genes encoding the muscle fiber type isoforms and involved in FA uptake and oxidation, carnitine transport, tricarboxylic acid cycle, oxidative phosphorylation, and glucose utilization were largely unaffected by NA supplementation in all 3 muscles. Supplementation of NA had no effect on plasma TG and NEFA concentrations, liver TG concentrations, and hepatic expression of genes involved in hepatic FA utilization and lipogenesis. However, it reduced plasma β-hydroxybutyrate concentrations in wk 2 and 3 p.p. by 18 and 26% and reduced hepatic gene expression of fibroblast growth factor 21, a stress hormone involved in the regulation of ketogenesis, by 74 and 56%. In conclusion, a high dosage of rumen-protected NA reduced plasma β-hydroxybutyrate concentrations in cows during early lactation, but failed to cause an alteration in muscle fiber composition and muscle metabolic phenotype.
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Affiliation(s)
- J O Zeitz
- Institute of Animal Nutrition and Nutritional Physiology, University of Giessen, Heinrich-Buff-Ring 26-32 (IFZ), 35392 Giessen, Germany.
| | - A Weber
- Institute of Animal Nutrition and Nutritional Physiology, University of Giessen, Heinrich-Buff-Ring 26-32 (IFZ), 35392 Giessen, Germany
| | - E Most
- Institute of Animal Nutrition and Nutritional Physiology, University of Giessen, Heinrich-Buff-Ring 26-32 (IFZ), 35392 Giessen, Germany
| | - W Windisch
- Chair of Animal Nutrition, Technische Universität München, Liesel-Beckmann-Strasse 2, 85354 Freising, Germany
| | - C Bolduan
- Chair of Animal Nutrition, Technische Universität München, Liesel-Beckmann-Strasse 2, 85354 Freising, Germany
| | - J Geyer
- Institute of Pharmacology and Toxicology, University of Giessen, Schubertstraße 81 (BFS), 35392 Giessen, Germany
| | - F-J Romberg
- Educational and Research Centre for Animal Husbandry, Hofgut Neumuehle, 67728 Muenchweiler an der Alsenz, Germany
| | - C Koch
- Educational and Research Centre for Animal Husbandry, Hofgut Neumuehle, 67728 Muenchweiler an der Alsenz, Germany
| | - K Eder
- Institute of Animal Nutrition and Nutritional Physiology, University of Giessen, Heinrich-Buff-Ring 26-32 (IFZ), 35392 Giessen, Germany
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Geyer J, Korfhage T. Labor supply effects of long-term care reform in Germany. Health Econ 2018; 27:1328-1339. [PMID: 29700888 DOI: 10.1002/hec.3663] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 03/20/2018] [Accepted: 03/23/2018] [Indexed: 06/08/2023]
Abstract
Many informal caregivers are of working age, facing the double burden of providing care and working. Negative labor supply effects can severely reduce the comparative cost advantage of informal over formal care arrangements. When designing long-term care (LTC) policies, it is crucial to understand the effects not only on health outcomes but also on labor supply behavior of informal caregivers. We evaluate labor supply reactions to the introduction of the German long-term care insurance in 1995 using a difference-in-differences approach. The long-term care insurance changes the caregivers' trade-off between labor supply and care provision. The aim of the reform was to strengthen informal care arrangements. We find a strong negative labor supply effect for men but not for women. We argue that the LTC benefits increased incentives for older men to leave the labor market. The results reveal a trade-off for policy makers that is important for future reforms-in particular for countries that mainly base their LTC system on informal care.
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Zhang H, Zhu B, Park S, Doerr C, Aydinlik M, Geyer J, Pfau T, Pendock G, Aroca R, Liu F, Rasmussen C, Mikkelsen B, Borel PI, Geisler T, Jensen R, Peckham DW, Lingle R, Vaidya D, Yan MF, Wisk PW, DiGiovanni DJ. Real-time transmission of 16 Tb/s over 1020km using 200Gb/s CFP2-DCO. Opt Express 2018; 26:6943-6948. [PMID: 29609380 DOI: 10.1364/oe.26.006943] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 03/01/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate real-time transmission of 16 Tb/s (80x200Gb/s) over 1020km TeraWave ULL fiber with 170km span length using the world's first 200Gb/s CFP2-DCO module with a record low power consumption less than 0.1W/Gbps.
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Fietz D, Markmann M, Lang D, Konrad L, Geyer J, Kliesch S, Chakraborty T, Hossain H, Bergmann M. Transfection of Sertoli cells with androgen receptor alters gene expression without androgen stimulation. BMC Mol Biol 2015; 16:23. [PMID: 26715186 PMCID: PMC4696255 DOI: 10.1186/s12867-015-0051-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 12/09/2015] [Indexed: 12/14/2022] Open
Abstract
Background Androgens play an important role for the development of male fertility and gained interest as growth and survival factors for certain types of cancer. Androgens act via the androgen receptor (AR/Ar), which is involved in various cell biological processes such as sex differentiation. To study the functional mechanisms of androgen action, cell culture systems and AR-transfected cell lines are needed. Transfection of AR into cell lines and subsequent gene expression analysis after androgen treatment is well established to investigate the molecular biology of target cells. However, it remains unclear how the transfection with AR itself can modulate the gene expression even without androgen stimulation. Therefore, we transfected Ar-deficient rat Sertoli cells 93RS2 by electroporation using a full length human AR. Results Transfection success was confirmed by Western Blotting, immunofluorescence and RT-PCR. AR transfection-related gene expression alterations were detected with microarray-based genome-wide expression profiling of transfected and non-transfected 93RS2 cells without androgen stimulation. Microarray analysis revealed 672 differentially regulated genes with 200 up- and 472 down-regulated genes. These genes could be assigned to four major biological categories (development, hormone response, immune response and metabolism). Microarray results were confirmed by quantitative RT-PCR analysis for 22 candidate genes. Conclusion We conclude from our data, that the transfection of Ar-deficient Sertoli cells with AR has a measurable effect on gene expression even without androgen stimulation and cause Sertoli cell damage. Studies using AR-transfected cells, subsequently stimulated, should consider alterations in AR-dependent gene expression as off-target effects of the AR transfection itself. Electronic supplementary material The online version of this article (doi:10.1186/s12867-015-0051-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- D Fietz
- Institute of Veterinary Anatomy, Histology and Embryology, Justus Liebig University, Frankfurter Straße 98, 35392, Giessen, Germany.
| | - M Markmann
- Institute of Medical Microbiology, Justus Liebig University, Giessen, Germany.
| | - D Lang
- Institute of Veterinary Anatomy, Histology and Embryology, Justus Liebig University, Frankfurter Straße 98, 35392, Giessen, Germany.
| | - L Konrad
- Department of Gynecology and Obstetrics, Justus Liebig University, Giessen, Germany.
| | - J Geyer
- Institute of Veterinary Anatomy, Histology and Embryology, Justus Liebig University, Frankfurter Straße 98, 35392, Giessen, Germany.
| | - S Kliesch
- Department of Clinical Andrology, Centre for Reproductive Medicine and Andrology, University Clinic Münster, Münster, Germany.
| | - T Chakraborty
- Institute of Medical Microbiology, Justus Liebig University, Giessen, Germany.
| | - H Hossain
- Institute of Medical Microbiology, Justus Liebig University, Giessen, Germany.
| | - M Bergmann
- Institute of Veterinary Anatomy, Histology and Embryology, Justus Liebig University, Frankfurter Straße 98, 35392, Giessen, Germany.
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Geyer J, Korfhage T. Long-term Care Insurance and Carers' Labor Supply - A Structural Model. Health Econ 2015; 24:1178-1191. [PMID: 26033403 DOI: 10.1002/hec.3200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 04/13/2015] [Accepted: 04/24/2015] [Indexed: 06/04/2023]
Abstract
In Germany, individuals in need of long-term care receive support through benefits of the long-term care insurance. A central goal of the insurance is to support informal care provided by family members. Care recipients can choose between benefits in kind (formal home care services) and benefits in cash. From a budgetary perspective, family care is often considered a cost-saving alternative to formal home care and to stationary nursing care. However, the opportunity costs resulting from reduced labor supply of the carer are often overlooked. We focus on the labor supply decision of family carers and the incentives set by the long-term care insurance. We estimate a structural model of labor supply and the choice of benefits of family carers. We find that benefits in kind have small positive effects on labor supply. Labor supply elasticities of cash benefits are larger and negative. If both types of benefits increase, negative labor supply effects are offset to a large extent. However, the average effect is significantly negative.
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Affiliation(s)
- Johannes Geyer
- German Institute for Economic Research (DIW), Berlin, Germany
| | - Thorben Korfhage
- Rheinisch-Westfälisches Institut für Wirtschaftsforschung (RWI), Berlin, Germany
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Neunzig J, Sánchez-Guijo A, Mosa A, Hartmann MF, Geyer J, Wudy SA, Bernhardt R. A steroidogenic pathway for sulfonated steroids: the metabolism of pregnenolone sulfate. J Steroid Biochem Mol Biol 2014; 144 Pt B:324-33. [PMID: 25038322 DOI: 10.1016/j.jsbmb.2014.07.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 07/11/2014] [Accepted: 07/14/2014] [Indexed: 10/25/2022]
Abstract
In many tissues sulfonated steroids exceed the concentration of free steroids and recently they were also shown to fulfill important physiological functions. While it was previously demonstrated that cholesterol sulfate (CS) is converted by CYP11A1 to pregnenolone sulfate (PregS), further conversion of PregS has not been studied in detail. To investigate whether a steroidogenic pathway for sulfonated steroids exists similar to the one described for free steroids, we examined the interaction of PregS with CYP17A1 in a reconstituted in-vitro system. Difference spectroscopy revealed a Kd-value of 74.8±4.2μM for the CYP17A1-PregS complex, which is 2.5-fold higher compared to the CYP17A1-pregnenolone (Preg) complex. Mass spectrometry experiments proved for the first time that PregS is hydroxylated by CYP17A1 at position C17, identically to pregnenolone. A higher Km- and a lower kcat-value for CYP17A1 using PregS compared with Preg were observed, indicating a 40% reduced catalytic efficiency when using the sulfonated steroid. Furthermore, we analyzed whether the presence of cytochrome b5 (b5) has an influence on the CYP17A1 dependent conversion of PregS, as was demonstrated for Preg. Interestingly, with 17OH-PregS no scission of the 17,20-carbon-carbon bond occurs, when b5 is added to the reconstituted in-vitro system, while b5 promotes the formation of DHEA from 17OH-Preg. When using human SOAT-HEK293 cells expressing CYP17A1 and CPR, we could confirm that PregS is metabolized to 17OH-PregS, strengthening the potential physiological meaning of a pathway for sulfonated steroids.
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Affiliation(s)
- J Neunzig
- Department of Biochemistry, Faculty of Technical and Natural Sciences III, Saarland University, 66123 Saarbrücken, Germany
| | - A Sánchez-Guijo
- Steroid Research & Mass Spectrometry Unit, Division of Pediatric Endocrinology & Diabetology, Center of Child and Adolescent Medicine, Justus-Liebig University, 35392 Giessen, Germany
| | - A Mosa
- Department of Biochemistry, Faculty of Technical and Natural Sciences III, Saarland University, 66123 Saarbrücken, Germany
| | - M F Hartmann
- Steroid Research & Mass Spectrometry Unit, Division of Pediatric Endocrinology & Diabetology, Center of Child and Adolescent Medicine, Justus-Liebig University, 35392 Giessen, Germany
| | - J Geyer
- Institute of Pharmacology and Toxicology, Justus-Liebig University of Giessen, 35392 Giessen, Germany
| | - S A Wudy
- Steroid Research & Mass Spectrometry Unit, Division of Pediatric Endocrinology & Diabetology, Center of Child and Adolescent Medicine, Justus-Liebig University, 35392 Giessen, Germany
| | - R Bernhardt
- Department of Biochemistry, Faculty of Technical and Natural Sciences III, Saarland University, 66123 Saarbrücken, Germany.
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Schweigmann H, Sánchez-Guijo A, Ugele B, Hartmann K, Hartmann MF, Bergmann M, Pfarrer C, Döring B, Wudy SA, Petzinger E, Geyer J, Grosser G. Transport of the placental estriol precursor 16α-hydroxy-dehydroepiandrosterone sulfate (16α-OH-DHEAS) by stably transfected OAT4-, SOAT-, and NTCP-HEK293 cells. J Steroid Biochem Mol Biol 2014; 143:259-65. [PMID: 24717977 DOI: 10.1016/j.jsbmb.2014.03.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 03/24/2014] [Accepted: 03/31/2014] [Indexed: 11/25/2022]
Abstract
16α-Hydroxy-dehydroepiandrosterone sulfate (16α-OH-DHEAS) mainly originates from the fetus and serves as precursor for placental estriol biosynthesis. For conversion of 16α-OH-DHEAS to estriol several intracellular enzymes are required. However, prior to enzymatic conversion, 16α-OH-DHEAS must enter the cells by carrier mediated transport. To identify these carriers, uptake of 16α-OH-DHEAS by the candidate carriers organic anion transporter OAT4, sodium-dependent organic anion transporter SOAT, Na(+)-taurocholate cotransporting polypeptide NTCP, and organic anion transporting polypeptide OATP2B1 was measured in stably transfected HEK293 cells by LC-MS-MS. Furthermore, the study aimed to localize SOAT in the human placenta. Stably transfected OAT4-HEK293 cells revealed a partly sodium-dependent transport for 16α-OH-DHEAS with an apparent Km of 23.1 ± 5.1 μM and Vmax of 485.0 ± 39.1 pmol/mg protein/min, while stably transfected SOAT- and NTCP-HEK293 cells showed uptake only under sodium conditions with Km of 319.0 ± 59.5 μM and Vmax of 1465.8 ± 118.8 pmol/mg protein/min for SOAT and Km of 51.4 ± 9.9 μM and Vmax of 1423.3 ± 109.6 pmol/mg protein/min for NTCP. In contrast, stably transfected OATP2B1-HEK293 cells did not transport 16α-OH-DHEAS at all. Immunohistochemical studies and in situ hybridization of formalin fixed and paraffin embedded sections of human late term placenta showed expression of SOAT in syncytiotrophoblasts, predominantly at the apical membrane as well as in the vessel endothelium. In conclusion, OAT4, SOAT, and NTCP were identified as carriers for the estriol precursor 16α-OH-DHEAS. At least SOAT and OAT4 seem to play a functional role for the placental estriol synthesis as both are expressed in the syncytiotrophoblast of human placenta.
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Affiliation(s)
- H Schweigmann
- Institute of Pharmacology and Toxicology, Justus Liebig University of Giessen, 35392 Giessen, Germany
| | - A Sánchez-Guijo
- Steroid Research & Mass Spectrometry Unit, Division of Pediatric Endocrinology and Diabetology, Center of Child and Adolescent Medicine, Justus Liebig University of Giessen, 35392 Giessen, Germany
| | - B Ugele
- University Hospital, Ludwig Maximilians University of Munich, 80337 Munich, Germany
| | - K Hartmann
- Institute of Veterinary Anatomy, Histology and Embryology, Justus Liebig University of Giessen, 35392 Giessen, Germany
| | - M F Hartmann
- Steroid Research & Mass Spectrometry Unit, Division of Pediatric Endocrinology and Diabetology, Center of Child and Adolescent Medicine, Justus Liebig University of Giessen, 35392 Giessen, Germany
| | - M Bergmann
- Institute of Veterinary Anatomy, Histology and Embryology, Justus Liebig University of Giessen, 35392 Giessen, Germany
| | - C Pfarrer
- Department of Anatomy, University of Veterinary Medicine, 30173 Hannover, Germany
| | - B Döring
- Institute of Pharmacology and Toxicology, Justus Liebig University of Giessen, 35392 Giessen, Germany
| | - S A Wudy
- Steroid Research & Mass Spectrometry Unit, Division of Pediatric Endocrinology and Diabetology, Center of Child and Adolescent Medicine, Justus Liebig University of Giessen, 35392 Giessen, Germany
| | - E Petzinger
- Institute of Pharmacology and Toxicology, Justus Liebig University of Giessen, 35392 Giessen, Germany
| | - J Geyer
- Institute of Pharmacology and Toxicology, Justus Liebig University of Giessen, 35392 Giessen, Germany
| | - G Grosser
- Institute of Pharmacology and Toxicology, Justus Liebig University of Giessen, 35392 Giessen, Germany.
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Elmshäuser S, Straehle LC, Kranz J, Krebber R, Geyer J. Brain penetration of emodepside is increased in P-glycoprotein-deficient mice and leads to neurotoxicosis. J Vet Pharmacol Ther 2014; 38:74-9. [PMID: 25131706 DOI: 10.1111/jvp.12149] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 06/05/2014] [Indexed: 11/28/2022]
Abstract
The antiparasitic drug emodepside (EMO) is a substrate of the P-glycoprotein multidrug efflux carrier (P-gp; syn. MDR1, ABCB1), which has an important function in protecting the brain from potentially toxic compounds by functional drug efflux at the blood-brain barrier (BBB). Many dogs of the Collie breed and even dogs of many other breeds have a loss-of-function 4-bp deletion mutation in the MDR1 gene. In these dogs, brain penetration of many P-gp-transported drugs is increased and so their therapeutic usage is restricted. To elucidate the role of P-gp at the BBB for the brain penetration of EMO, we applied EMO at 1 mg/kg to mdr1-deficient (PGP(mut) ) and mdr1-intact (PGP(WT) ) CF1 mice. Whereas in the brain of the PGP(WT) mice, EMO was below the detection level of 10 ng/g, its concentration was at 43.7 ng/g in the PGP(mut) mice. Furthermore, appearance of neurological toxicity was analyzed in these mice after application of 1 mg/kg EMO using a rotarod setup. In all PGP(mut) mice, but not in the PGP(WT) mice, the walking performance on the rotarod was impaired by EMO with clear differences in the degree and duration of neurological toxicity. Some of the mice were completely unable to walk on the rotarod already at 2 h after drug application and showed long-lasting ataxia over >24 h. Others even showed significantly reduced walking performance, but completely recovered within 1 day. In conclusion, P-gp restricts brain penetration of EMO and prevents neurological toxicity of this drug in mice.
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Affiliation(s)
- S Elmshäuser
- Institute of Pharmacology and Toxicology, Justus Liebig University of Giessen, Giessen, Germany
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Dreyfuss J, Geyer J, Stamper MA, Baldessari A, Lewbart GA. Zinc toxicosis in a brook trout, Salvelinus fontinalis Mitchill. J Fish Dis 2014; 37:397-399. [PMID: 23763438 DOI: 10.1111/jfd.12130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 04/20/2013] [Indexed: 06/02/2023]
Affiliation(s)
- J Dreyfuss
- College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
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Fietz D, Bakhaus K, Wapelhorst B, Hartmann K, Sánchez-Guijo A, Hartmann MF, Wudy SA, Kliesch S, Weidner W, Bergmann M, Geyer J. SOAT – a steroid sulfate carrier relevant for male reproduction? (subproject 2, DFG research group 1369 “Sulfated Steroids in Reproduction). Exp Clin Endocrinol Diabetes 2014. [DOI: 10.1055/s-0034-1371991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Gramer I, Kessler M, Geyer J. Determination of MDR1 gene expression for prediction of chemotherapy tolerance and treatment outcome in dogs with lymphoma. Vet Comp Oncol 2013; 13:363-72. [PMID: 23834200 DOI: 10.1111/vco.12051] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 05/29/2013] [Indexed: 11/28/2022]
Abstract
The multidrug resistance gene 1(MDR1) expression levels were analysed in 27 dogs with different types of malignant lymphomas receiving a standard chemotherapy protocol. Blood samples were used for MDR1 real-time PCR expression analysis. Treatment tolerance and outcome were evaluated on a regular basis by clinical examination and client questioning. Dogs developing severe adverse effects under treatment showed significantly lower basal MDR1 gene expression levels when compared with those who tolerated the drugs well. In the longitudinal MDR1 gene expression analysis during treatment, four dogs showed a greater than two-fold MDR1 up-regulation, compared to baseline expression. All four of these dogs, but none of the others, showed disease progression. In conclusion, basal and follow-up MDR1 gene expression levels could be of predictive value for the occurrence of severe adverse drug reactions and/or the development of MDR during chemotherapy for lymphoma in dogs.
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Affiliation(s)
- I Gramer
- Institute of Pharmacology and Toxicology, Justus Liebig University of Giessen, Giessen, Germany.,Hofheim Animal Hospital, Hofheim am Taunus, Germany
| | - M Kessler
- Hofheim Animal Hospital, Hofheim am Taunus, Germany
| | - J Geyer
- Institute of Pharmacology and Toxicology, Justus Liebig University of Giessen, Giessen, Germany
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Burger S, Döring B, Hardt M, Beuerlein K, Gerstberger R, Geyer J. Corrigendum to “Co-expression studies of the orphan carrier protein SLC10A4 and the vesicular carriers VAChT and VMAT2 in the rat central and peripheral nervous system” [Neuroscience 193 (2011) 109–121]. Neuroscience 2012. [DOI: 10.1016/j.neuroscience.2012.04.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Hessel S, Gavrilova O, John A, Seidel A, Geyer J, Lampen A. The important role of BCRP for in vivo disposition of benzo[a]pyrene conjugates in the liver and intestine. Toxicol Lett 2011. [DOI: 10.1016/j.toxlet.2011.05.656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Maynard M, Geyer J, Aris J, Shifrin R, Bolch W. SU-E-I-50: The UF Family of Hybrid Phantoms of the Developing Human Fetus for Computational Radiation Dosimetry. Med Phys 2011. [DOI: 10.1118/1.3611623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Maynard M, Geyer J, Aris J, Shifrin R, Bolch W. SU-GG-I-51: Hybrid Computational Phantoms of the Developing Human Fetus. Med Phys 2010. [DOI: 10.1118/1.3468084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Geyer J, Gavrilova O, Petzinger E. Brain penetration of ivermectin and selamectin in mdr1a,b P-glycoprotein- and bcrp- deficient knockout mice. J Vet Pharmacol Ther 2009; 32:87-96. [PMID: 19161460 DOI: 10.1111/j.1365-2885.2008.01007.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
P-glycoprotein, which is encoded by the multi-drug resistance gene (MDR1), highly restricts the entry of ivermectin into the brain by an ATP-driven efflux mechanism at the blood-brain barrier. In dogs with a homozygous MDR1 mutation though, ivermectin accumulates in the brain and provokes severe signs of neurotoxicosis and even death. In contrast to ivermectin, selamectin is safer in the treatment of MDR1 mutant dogs, suggesting that selamectin is transported differently by P-glycoprotein across the blood-brain barrier. To test this, we applied selamectin to mdr1-deficient mdr1a,b(-/-) knockout mice and wild-type mice. Brain penetration, organ distribution, and plasma kinetics were analyzed after intravenous, oral, and dermal spot-on application in comparison with ivermectin. We found that in vivo both macrocyclic lactone compounds are substrates of P-glycoprotein and that these strongly accumulate in the brain of mdr1a,b(-/-) knockout mice compared with wild-type mice at therapeutic doses of 12 mg/kg selamectin and 0.2 mg/kg ivermectin. However, selamectin accumulates to a much lesser degree (5-10 times) than ivermectin (36-60 times) in the absence of P-glycoprotein. This could explain the broader margin of safety of selamectin in MDR1 mutant dogs. In liver, kidney, and testes, ivermectin and selamectin accumulated less than four times as much in mdr1a,b mutant mice as in wild-type mice. Breast cancer resistance protein (Bcrp)-deficient bcrp(-/-) knockout mice were also included in the application studies, but showed no differences in brain concentrations or organ distribution of either ivermectin or selamectin compared with wild-type mice. This indicates that Bcrp is not a relevant efflux carrier for these macrocyclic lactone compounds in vivo at the blood-brain barrier.
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Affiliation(s)
- J Geyer
- Institute of Pharmacology and Toxicology, Justus Liebig University of Giessen, Giessen, Germany.
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Cavalcanti M, Rizgalla M, Geyer J, Failing K, Litzke LF, Bergmann M. Expression of histone 1 (H1) and testis-specific histone 1 (H1t) genes during stallion spermatogenesis. Anim Reprod Sci 2009; 111:220-34. [DOI: 10.1016/j.anireprosci.2008.03.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2007] [Revised: 03/02/2008] [Accepted: 03/13/2008] [Indexed: 11/16/2022]
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Geyer J, Klintzsch S, Meerkamp K, Wöhlke A, Distl O, Moritz A, Petzinger E. Detection of the nt230(del4) MDR1 mutation in White Swiss Shepherd dogs: case reports of doramectin toxicosis, breed predisposition, and microsatellite analysis. J Vet Pharmacol Ther 2007; 30:482-5. [PMID: 17803743 DOI: 10.1111/j.1365-2885.2007.00885.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- J Geyer
- Institute of Pharmacology and Toxicology, College of Veterinary Medicine, Justus-Liebig-University of Giessen, Giessen, Germany.
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Greven H, Kowalewski MP, Hoffmann B, Geyer J, Rex-Haffner M, Ugele B, Schuler G. Bovine Placental Steroid Sulphatase: Molecular Cloning and Expression Pattern in Placentomes during Gestation and at Parturition. Placenta 2007; 28:889-97. [PMID: 17350090 DOI: 10.1016/j.placenta.2007.01.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2006] [Revised: 01/08/2007] [Accepted: 01/12/2007] [Indexed: 10/23/2022]
Abstract
Apart from during the prepartal period, the main oestrogen produced by the bovine trophoblast is oestrone sulphate (E1S) which does not bind to nuclear oestrogen receptors (ER). High steroid sulphatase (StS) activities previously detected in the maternal part of bovine placentomes (caruncles) suggest the local activation of E1S ("sulphatase pathway"). Consequently, the expression pattern of StS in bovine placentomes was investigated by immunohistochemistry using an antiserum against human placental StS. Cross-reactivity for bovine StS was confirmed by Western blot yielding a single band of 62 kDa in both bovine and human placenta. Immunostaining for StS was detected in caruncular epithelial cells (CEC), which was clearly related to gestational age. In animals pregnant between 100 and 284 days (n=17), signals were restricted to CEC adjacent to the chorionic plate and basal primary and secondary chorionic villi. After the onset of prepartal luteolysis (days 273-282; n=3) and during active labour (n=5) overall staining intensity had increased substantially and signals occurred ubiquitously in the flattened and partially dismantled caruncular epithelium. A 2204 bp full-length mRNA transcript of the bovine StS exhibiting 74% and 77% sequence identity to human StS on the mRNA and protein levels, respectively, was cloned by RACE-PCR. Real-time RT-PCR detected a 2.5-fold increase of StS-mRNA in prepartal placentomes, which, however, was not statistically significant. The co-localisation of ERalpha and StS in CEC is consistent with a role of placental oestrogens as regulators of caruncular growth and differentiation, and the up-regulation of carunclar StS may be involved in the marked prepartal increase of free oestrogens.
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Affiliation(s)
- H Greven
- Clinic for Obstetrics, Gynecology and Andrology of Large and Small Animals, Faculty of Veterinary Medicine, Justus-Liebig-University, Frankfurter Strasse 106, D-35392 Giessen, Germany
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Geyer J, Wilke T, Petzinger E. The solute carrier family SLC10: more than a family of bile acid transporters regarding function and phylogenetic relationships. Naunyn Schmiedebergs Arch Pharmacol 2006; 372:413-31. [PMID: 16541252 DOI: 10.1007/s00210-006-0043-8] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2005] [Accepted: 01/31/2006] [Indexed: 12/18/2022]
Abstract
The solute carrier family 10 (SLC10) comprises two sodium-dependent bile acid transporters, i.e. the Na(+)/taurocholate cotransporting polypeptide (NTCP; SLC10A1) and the apical sodium-dependent bile acid transporter (ASBT; SLC10A2). These carriers are essentially involved in the maintenance of the enterohepatic circulation of bile acids mediating the first step of active bile acid transport through the membrane barriers in the liver (NTCP) and intestine (ASBT). Recently, four new members of the SLC10 family were described and referred to as P3 (SLC10A3), P4 (SLC10A4), P5 (SLC10A5) and sodium-dependent organic anion transporter (SOAT; SLC10A6). Experimental data supporting carrier function of P3, P4, and P5 is currently not available. However, as demonstrated for SOAT, not all members of the SLC10 family are bile acid transporters. SOAT specifically transports steroid sulfates such as oestrone-3-sulfate and dehydroepiandrosterone sulfate in a sodium-dependent manner, and is considered to play an important role for the cellular delivery of these prohormones in testes, placenta, adrenal gland and probably other peripheral tissues. ASBT and SOAT are the most homologous members of the SLC10 family, with high sequence similarity ( approximately 70%) and almost identical gene structures. Phylogenetic analyses of the SLC10 family revealed that ASBT and SOAT genes emerged from a common ancestor gene. Structure-activity relationships of NTCP, ASBT and SOAT are discussed at the amino acid sequence level. Based on the high structural homology between ASBT and SOAT, pharmacological inhibitors of the ASBT, which are currently being tested in clinical trials for cholesterol-lowering therapy, should be evaluated for their cross-reactivity with SOAT.
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Affiliation(s)
- J Geyer
- Institut für Pharmakologie und Toxikologie, Justus-Liebig-Universität Giessen, Frankfurter Strasse 107, 35392, Giessen, Germany.
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Geyer J, Döring B, Godoy JR, Leidolf R, Moritz A, Petzinger E. Frequency of the nt230 (del4) MDR1 mutation in Collies and related dog breeds in Germany. J Vet Pharmacol Ther 2005; 28:545-51. [PMID: 16343287 DOI: 10.1111/j.1365-2885.2005.00692.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
MDR1 (ABCB1) P-glycoprotein exerts a protective function in the blood-brain barrier thereby limiting the entry of many drugs and other xenobiotics to the central nervous system. A nonsense mutation has been described for Collies and related dog breeds which abolishes this function and is associated with increased susceptibility to neurotoxic side effects of several drugs including ivermectin, moxidectin and loperamide. In order to evaluate the occurrence and frequency of this nt230 (del4) MDR1 mutation in Germany, we screened 1500 dogs. Frequency of the homozygous mutated genotype was highest for Collies (33.0%), followed by Australian Shepherd (6.9%) and Shetland Sheepdog (5.7%). Thirty-seven percent of the Wäller dogs and 12.5% of the Old English Sheepdogs were heterozygous for the mutant MDR1 (-) allele. Considering the predominant role of MDR1 P-glycoprotein in drug disposition and in particular for blood-brain barrier protection, MDR1 genotype-based breeding programs are recommended for improving the safety of drug therapy in these canine breeds.
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Affiliation(s)
- J Geyer
- Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Justus-Liebig-University of Giessen, Giessen, Germany
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Geyer J, Döring B, Godoy JR, Moritz A, Petzinger E. Development of a PCR-based diagnostic test detecting a nt230(del4) MDR1 mutation in dogs: verification in a moxidectin-sensitive Australian Shepherd. J Vet Pharmacol Ther 2005; 28:95-9. [PMID: 15720521 DOI: 10.1111/j.1365-2885.2004.00625.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A subpopulation of dogs of the Collie and Australian Shepherd breeds show increased sensitivity to central nervous actions of ivermectin, doramectin, loperamide, and probably several other drugs. The molecular background for this greater sensitivity is a nonsense mutation in the MDR1 efflux pump, which is part of the functional blood-brain barrier and normally limits drug penetration into the brain. This report describes a rapid PCR-based method for detection of this nt230(del4) MDR1 mutation using a small amount of genomic DNA from blood cells. Thereby, homozygous intact, homozygous mutated, and heterozygous mutated MDR1 genotypes can be clearly differentiated by high resolution polyacrylamide gel electrophoresis. Using this diagnostic test two Collies and one Australian Shepherd were screened for the nt230(del4) MDR1 mutation. The Collies had no history of altered drug sensitivity and showed homozygous intact and heterozygous mutated MDR1 alleles, respectively. However, the Australian Shepherd developed clear signs of neurotoxicity including ataxia, crawling, acoustic and tactile hyperexcitability, and miosis after a single dose of moxidectin (400 microg/kg). For this dog two mutated MDR1 alleles were detected. This report describes for the first time moxidectin neurotoxicosis in a dog with a homozygous MDR1 mutation.
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Affiliation(s)
- J Geyer
- Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Justus-Liebig-University of Giessen, Giessen, Germany
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Daphnis DD, Delhanty JDA, Jerkovic S, Geyer J, Craft I, Harper JC. Detailed FISH analysis of day 5 human embryos reveals the mechanisms leading to mosaic aneuploidy. Hum Reprod 2005; 20:129-37. [PMID: 15567885 DOI: 10.1093/humrep/deh554] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Fluorescence in situ hybridization (FISH) analysis has shown that human embryos display a high level of chromosomal mosaicism at all preimplantation stages. The aim of this study was to investigate the mechanisms involved by the use of two probes for each of three autosomes at different loci and to determine the true level of aneuploid mosaicism by excluding FISH artefacts. METHODS Embryos were cultured in two different types of medium: group I were cultured in standard cleavage medium for up to day 5 and group II were cultured from day 3 to day 5 in blastocyst medium. Three rounds of FISH were performed. In round 1, the probes used were 1pTel, 11qTel and 18CEP; in round 2, the probes used were 1satII/III, 11CEP and 18qTel; in round 3, the probes used were 18CEP, XCEP and YCEP. RESULTS A total of 21 embryos were analysed in each group. The FISH results revealed one uniformly diploid and 20 mosaic embryos for group I, and two uniformly diploid and 19 mosaic embryos for group II. The predominant type of mosaicism was diploid/aneuploid. The use of two different probes per autosome was able to distinguish FISH artefacts affecting 5% of nuclei from true single cell anomalies. CONCLUSIONS Post-zygotic chromosome loss was the most common mechanism leading to aneuploidy mosaicism for both groups, followed by chromosome gain, with fewer examples of mitotic non-disjunction.
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Affiliation(s)
- D D Daphnis
- UCL Centre for Preimplantation Genetic Diagnosis, Department of Obstetrics and Gynaecology, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK
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Stracke H, Hammes HP, Werkmann D, Mavrakis K, Bitsch I, Netzel M, Geyer J, Köpcke W, Sauerland C, Bretzel RG, Federlin KF. Efficacy of benfotiamine versus thiamine on function and glycation products of peripheral nerves in diabetic rats. Exp Clin Endocrinol Diabetes 2002; 109:330-6. [PMID: 11571671 DOI: 10.1055/s-2001-17399] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In rats with streptozotocin (STZ) induced diabetes the effect of (watersoluble) thiamine nitrate and of (lipidsoluble) benfotiamine on peripheral nerve function (motor nerve conduction velocity) as well as on the formation of advanced glycation end-products in peripheral nerve tissue was studied. In one group of animals drug administration was started immediately after diabetes induction (prevention study) and in another group two months after diabetes induction (treatment study). Motor nerve conduction velocity (NCV) dropped by 10.5% in diabetic animals, carboxymethyl-lysine (CML) rose to a 3.5fold concentration, deoxyglucosone (3DG)-type AGE formation was increased 5.1fold compared with controls. After three months preventive administration of both vitamin B(1) preparations NCV had increased substantially compared with results in diabetic controls. It was nearly normal after six months with benfotiamine, while the administration of thiamine nitrate resulted in no further amelioration. NCV was nearly normalized after six months of benfotiamine application but not with thiamine. Furthermore, benfotiamine induced a major inhibition of neural imidazole-type AGE formation and completely prevented diabetes induced glycoxidation products (CML). Treatment with thiamine did not significantly affect AGE or cmL levels. Unlike treatment with water-soluble thiamine nitrate timely administration of liposoluble prodrug benfotiamine was effective in the prevention of functional damage and of AGE and cmL formation in nerves of diabetic rats.
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Affiliation(s)
- H Stracke
- Center of Internal Medicine, Department of Endocrinology and Metabolism, University of Giessen, Rodthohl 6, D-35385 Giessen, Germany.
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Abstract
BACKGROUND Obtaining informed consent to treatment is an important medical-legal and clinical aspect of neurological practice. REVIEW SUMMARY This review discusses the doctrine of informed consent and its role in neurological practice. We first provide an overview of the informed consent doctrine and discuss its historical origins and current modern form. The three component elements of informed consent--being informed, voluntary, and competent--are presented, with a focus placed on the competency element. The increasingly important role of informed consent in everyday neurological practice is profiled, with particular emphasis on patients with dementia. Recent empirical research is presented on loss of consent capacity (competency) in patients with Alzheimer's disease and Parkinson's disease. Finally, a conceptually based approach to clinical assessment of competency is presented to assist neurologists dealing with these issues. CONCLUSIONS The increasing prevalence of patients with neurodegenerative disorders in neurological practice heightens the importance of obtaining valid informed consent to treatment.
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Affiliation(s)
- D Marson
- Department of Neurology, UAB Alzheimer's Disease Research Center, and UAB Center for Aging, University of Alabama at Birmingham, Birmingham, Alabama 35233-7243, USA.
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Geyer J, Netzel M, Bitsch I, Frank T, Bitsch R, Krämer K, Hoppe PP. Bioavailability of water- and lipid-soluble thiamin compounds in broiler chickens. INT J VITAM NUTR RES 2000; 70:311-6. [PMID: 11214357 DOI: 10.1024/0300-9831.70.6.311] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The bioavailability of thiamin mononitrate, thiamin chloride-hydrochloride and benfotiamin was compared in broiler chickens. A thiamin-deficient diet was supplemented with either 1.8 and 1.5 mg/kg thiamin equivalent as water-soluble salts, or with 1.5 and 1.2 mg/kg thiamin equivalent as benfotiamin, respectively, and fed to 3 replicate groups/treatment for 21 days. Weight gain, feed consumption and feed conversion rate were not significantly affected by solubility or dietary level of thiamin. Likewise, using biochemical indices of thiamin status (erythrocyte transketolase activation coefficient, and thiamin concentrations in blood and liver), no differences were found between the water-soluble thiamin salts, indicating that they have identical potency. In contrast, biochemical indices of thiamin status showed a significantly higher bioavailability for benfotiamin than for the water-soluble sources.
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Affiliation(s)
- J Geyer
- Institute of Nutritional Sciences, University of Giessen, Wilhelmstr. 20, D-35392 Giessen
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Abstract
PURPOSE To determine whether differences in clinical manifestations of psychogenic nonepileptic events are associated with differences in outcome and whether the length of illness before diagnosis correlates with outcome. METHODS We reviewed ictal videotapes and EEGs in 85 patients diagnosed with exclusively nonepileptic psychogenic seizures during inpatient CCTV-EEG monitoring at the University of Michigan between June 1994 and December 1996. They were classified into groups of similar ictal behaviors. Fifty-seven of these patients were available to respond to a follow-up telephone survey about their condition 2-4 years after discharge. We examined demographics, baseline EEG abnormalities, and outcome of treatment interventions. We also evaluated whether interventions were more likely to succeed if patients were diagnosed early in the course of the illness. RESULTS We found that the largest groups consisted of patients with motionless unresponsiveness ("catatonic," n = 19) and asynchronous motor movements with impaired responsiveness ("thrashing," n = 19). Infrequent signs included tremor, automatisms, subjective events with amnesia, and intermittent behaviors. There was a higher incidence of baseline EEG abnormalities in the thrashing group (31%) than in the catatonic group (0%). There was a higher incidence of complete remission of spells in the catatonic group (53%) than in the thrashing group (21%). Patients who had a more recent onset of seizures (most often within 1 year) were much more likely to have remission of spells after diagnosis. CONCLUSIONS Classification of nonepileptic seizures is useful in predicting outcome and may be valuable in further investigation of this complex set of disorders.
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Affiliation(s)
- L M Selwa
- University of Michigan Department of Neurology, Ann Arbor, USA.
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Abstract
When a pig is deprived of drinking water, a deficit of body water develops that is corrected when the pig drinks to satiation. If food is available during the deprivation, the stimulus to drinking is plasma hyperosmolality. Because of the delay in correction of plasma hyperosmolality as ingested water is slowly absorbed, it has been thought that a rapid inhibitory signal from the digestive tract is necessary to prevent overdrinking. This concept was tested by measuring changes in plasma osmolality before and during drinking after such deprivation and also after infusion of hypertonic saline. As drinking began, there was a rapid fall of plasma osmolality to levels insufficient to drive drinking by the time drinking ended. This fall of plasma hyperosmolality to subthreshold levels while the pig is drinking seems to make a rapid inhibitory control signal from the digestive tract unnecessary to terminate the drinking bout under these conditions.
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Affiliation(s)
- T R Houpt
- Department of Physiology, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853-6401, USA.
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ManWarren T, Gagliardo L, Geyer J, McVay C, Pearce-Kelling S, Appleton J. Invasion of intestinal epithelia in vitro by the parasitic nematode Trichinella spiralis. Infect Immun 1997; 65:4806-12. [PMID: 9353069 PMCID: PMC175690 DOI: 10.1128/iai.65.11.4806-4812.1997] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Studies of nematode establishment in intestinal niches has been hindered by the lack of a readily manipulated in vitro assay. In this report, experiments are described wherein the larval stage of the parasitic nematode Trichinella spiralis was shown to invade epithelial cell monolayers in vitro. Larvae penetrated cells and migrated through them, leaving trails of dead cells in their wake. Cells derived from five different species were susceptible to invasion, reflecting the broad host range of T. spiralis in vivo. Epithelial cells derived from large and small intestines and kidneys were susceptible. Fibroblast and muscle cells were resistant. Larvae deposited glycoprotein antigens in the cells they invaded. Although the function of these antigens is unknown, they are targeted by rat antibodies that cause T. spiralis to be expelled from the intestine. The model system described provides the means to further investigate this process as well as the mechanisms by which this parasitic nematode establishes its intestinal niche.
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Affiliation(s)
- T ManWarren
- James A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
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Bell EH, Geyer J, Jones L. A structured intervention improves breastfeeding success for ill or preterm infants. MCN Am J Matern Child Nurs 1995; 20:309-14. [PMID: 8551932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- E H Bell
- University of Iowa Hospitals and Clinics, Iowa City, USA
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Herrmann P, Ritz E, Schmidt-Gayk H, Schäfer I, Geyer J, Nonnast-Daniel B, Koch KM, Weber U, Hörl W, Haas-Wörle A. Comparison of intermittent and continuous oral administration of calcitriol in dialysis patients: a randomized prospective trial. Nephron Clin Pract 1994; 67:48-53. [PMID: 8052367 DOI: 10.1159/000187887] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Intermittent bolus administration of calcitriol--i.e., 1,25-dihydroxycholecalciferol or 1,25-(OH)2D3--is highly efficacious in dialysis patients. In experimental studies, intermittent administration of calcitriol is superior to continuous administration in suppressing preproparathyroid hormone (PTH) mRNA and circulating PTH concentrations. In a randomized, prospective, open multicenter trial 45 dialysis patients with elevated 1,84-iPTH (> or = 20 pmol/l, normal 1-6 pmol/l) levels were randomly allocated to daily administration of 0.75 microgram calcitriol (continuous) or twice weekly administration (intermittent); the two protocols provided an identical total weekly doses of 5.25 micrograms calcitriol. Patients were dialyzed with a dialysate Ca concentration of 1.75 mmol/l and had oral CaCO3 or Ca acetate. 1,84-iPTH (immunoradiometric assay) and serum Ca and Pi levels were measured weekly. At the beginning of the study, the median 1,84-iPTH value was 37 pmol/l (range 20-115) in the intermittent versus 36 pmol/l (range 21-72) in the continuous calcitriol group. After 2 weeks, the median 1,84-iPTH level was 18.5 pmol/l (range 1.4-106) versus 18 pmol/l (range 1.2-48). After 12 weeks, 11 of 21 of the patients in the intermittent and 18 of 24 patients in the continuous group had reached the treatment goal, i.e., 1,84-iPTH < or = 10 pmol/l without hypercalcemia or hyperphosphatemia. There were seven episodes of hypercalcemia (> 2.7 mmol/l) in the intermittent versus two in the continuous group; the mean peak Ca level was 2.8 mmol/l (range 2.76-3.0) versus 2.9 mmol/l (range 2.74-3.06). There were 21 versus 17 episodes, respectively, of hyperphosphatemia (> 2.2 mmol/l).
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Affiliation(s)
- P Herrmann
- Kuratorium für Heimdialyse, Medizinische Hochschule Hannover, BRD
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Stevens K, Cherlow J, Zeltzer P, Boyett J, Ayers D, Shurin S, Albright A, Allen J, Finlay J, Geyer J, McGuire P, Milstein J, Rorke L, Stanley P, Stehbens J, Wisoff J. The effect of pre-irradiation chemotherapy on the delivery of radiation therapy for medullobiastoma and supratentorial pnet. results of the ccg #921 randomized protocol. Int J Radiat Oncol Biol Phys 1993. [DOI: 10.1016/0360-3016(93)90639-d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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38
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Geyer J, Quadt C, Perlick E, Starke K, Stier G, Tanneberger S. Conventional radiograms for assessment of salm-calcitonin therapy for bone metastases from breast carcinoma. Eur J Radiol 1991; 12:124-6. [PMID: 2036999 DOI: 10.1016/0720-048x(91)90111-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The effects of salm-calcitonin on breast cancer osteolytic skeletal metastases have been studied on conventional radiographs. Radiographic criteria for positive response have been defined. It is concluded that radiographs are inadequate for assessing the effects of salm-calcitonin.
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Affiliation(s)
- J Geyer
- Central Institute for Cancer Research, Academy of Sciences, Berlin-Buch, F.R.G
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Loan C, Chase L, Asher W, Geyer J, Scholz DA, Tobin S. Pediatric emergency review: a "hands-on" approach. Pediatr Nurs 1990; 16:463-6. [PMID: 2216570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A "hands-on" approach to pediatric emergency review was developed to improve retention of psychomotor skills and instill critical thinking for pediatric nurses in anticipation of pediatric emergency situations.
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Quadt C, Geyer J, Wiener N, Stier G, Perlick E, Gürtler R, Marquardt J, Tanneberger S. Effects of salm-calcitonin on bone metastases in breast cancer patients. Eur J Pharmacol 1990. [DOI: 10.1016/0014-2999(90)92001-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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41
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Lenk H, Tanneberger S, Wiener N, Giesske H, Gärtner S, Geyer J, Rotte KH. Phase II study of pirarubicin (THP-adriamycin) in metastatic breast cancer patients. Oncology 1990; 47:97-100. [PMID: 2314831 DOI: 10.1159/000226796] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Fourteen patients with metastatic breast cancer previously treated with one chemotherapy regimen received Pirarubicin at a dose of 70 mg/m2 at 3-week intervals. In 7 patients the dose had to be reduced, in 1 patient to 40 mg/m2 and in 6 patients to 50-60 mg/m2. There were 1 complete and 2 partial remissions. These objective responses were observed in soft tissue, lung and pleural areas and lasted 1+; 4+ and 5+ months. Grade 3 and 4 leukopenia was found in 42%, grade 3 thrombocytopenia in 2%, grade 3 nausea/vomiting in 29% of the cycles. Grade 1 and 2 alopecia occurred in 64% of the patients, the remaining 36% of the patients did not suffer from any alopecia. No cardiotoxic side effects were observed in 13 patients. In 1 patient with severe coronary heart disease extrasystoles and reduction in left ventricular ejection fraction occurred. Pirarubicin has antitumor activity in previously treated metastatic breast cancer patients.
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Affiliation(s)
- H Lenk
- Central Institute for Cancer Research, Academy of Sciences, GDR, Berlin
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42
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Geyer J. Response to letter on i.v. infusions of gentamicin and ampicillin. Pediatr Nurs 1989; 15:514-5. [PMID: 2587110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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43
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Höffler D, Niemeyer R, Geyer J, Demers HG. [Sepsis due to Propionibacterium acnes?]. Dtsch Med Wochenschr 1989; 114:442. [PMID: 2707126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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44
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Rotte KH, Kriedemann E, Geyer J, Kunde D, Melcher J, Perlick E, Schmidt-Peter P. [The value of computed tomography in monitoring the preoperative chemotherapy of osteosarcoma]. ROFO-FORTSCHR RONTG 1989; 150:8-12. [PMID: 2536502 DOI: 10.1055/s-2008-1046965] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Computed tomography was performed in 45 patients with osteosarcomas before and after preoperative chemotherapy. Changes of bone alterations, intramedullary tumour spread and the size of soft tissue masses are computer tomographic criteria for tumour response after chemotherapy. The computed tomography decision of responder or non-responder was correct in 37/45 patients. In comparison with conventional x-rays CT was superior. CT is a reliable method for preoperative extension diagnosis and for the decision-marking for limb-saving operations.
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Affiliation(s)
- K H Rotte
- Zentralinstitut für Krebsforschung, Akademie der Wissenschaften der DDR
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45
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Geyer J, Höffler D, Koeppe P. Pharmacokinetics of aspoxicillin in subjects with normal and impaired renal function. Arzneimittelforschung 1988; 38:1635-9. [PMID: 3214450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The pharmacokinetics of aspoxicillin [2S,5R,6R)-6-[(2R)-2-[(2R)-2-amino-3-(methylcarbamoyl)propionam ido]-2- (p-hydroxyphenyl)acetamido]penicillanic acid) in 10 subjects with normal kidney function and in 20 patients suffering from impaired renal function were examined after an i.v. short-term infusion of 4 g for a period of 20 min. In contrast to available semi-synthetic penicillins, aspoxicillin shows a slightly longer half-life elimination. As the substance is mainly excreted renally, the areas under the curve (AUC) are larger in cases of impaired renal function. Mathematical correlations can be established between the AUC and the renal function parameters creatinine and glomerular filtration rate. Dosage reduction factors are then derived which allow appropriate dosages to be established for the substances under examination. Dosages for differing degrees of impaired renal function are given in tables. Since sufficiently high and long-lasting urine levels are achieved, it is reasonable to use aspoxicillin as treatment of urinary tract infections in patients suffering from end-stage renal failure.
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Affiliation(s)
- J Geyer
- Städtische Kliniken Darmstadt, Medizinische Klinik III, Fed. Rep. of Germany
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Geyer J, Murphey L, Oswald C. Person power: the power you have to be in charge of your life (how to reclaim it and make it work for you). Pediatr Nurs 1978; 4:17-9. [PMID: 246195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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48
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Horvath B, Geyer J, Krauss HL. �ber Oberfl�chenverbindungen von �bergangsmetallen. XIV. Koordinative unges�ttigte Oberfl�chenverbindungen von Vanadium(III) auf Silicagel. Z Anorg Allg Chem 1976. [DOI: 10.1002/zaac.19764260202] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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49
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