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Melching-Kollmuss S, Botham P, Charlton A, Guignard D, Ghaffari R, Jacobi S, Marty S, Marxfeld HA, Sauer U, Urbisch D. P21-21 Tiered testing and assessment to identify thyroid (hormone) disruptors. Toxicol Lett 2022. [DOI: 10.1016/j.toxlet.2022.07.701] [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: 11/29/2022]
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Hannas B, Asiimwe A, A. Botham P, Charlton A, Guignard D, Hallmark N, Jacobi S, Marty S, Melching-Kollmuss S, Sauer U, Schneider S, Strauss V, van Ravenzwaay B. Rodent thyroid toxicity and potential child neurodevelopmental impairment. Toxicol Lett 2021. [DOI: 10.1016/s0378-4274(21)00567-1] [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: 11/24/2022]
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3
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Van Deun K, Hatch H, Jacobi S, Köhl W. Lithium carbonate: Updated reproductive and developmental toxicity assessment using scientific literature and guideline compliant studies. Toxicology 2021; 461:152907. [PMID: 34454986 DOI: 10.1016/j.tox.2021.152907] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 07/18/2021] [Revised: 08/13/2021] [Accepted: 08/22/2021] [Indexed: 10/20/2022]
Abstract
The current publication describes most recent so far unpublished (key) guideline and GLP compliant reproductive and developmental toxicity studies of lithium carbonate in rats, including their interpretation and conclusions in terms of human hazard assessment when compared to existing literature. Particular attention was paid to the target organs and dose response of lithium ion related effects to differentiate between a primary (pharmacokinetic/pharmacodynamic) action and secondary effects as a result of systemic and target organ toxicity. In the key two-generation reproduction toxicity (OECD TG 416) study in rats, doses of 5, 15 and 45 mg/kg bw/d (0.95, 2.9 and 8.6 mg Li+/kg bw/d) were given by oral gavage, resulting in clear NOAELs of 15 mg/kg bw/d (2.9 mg Li+/kg bw/d) for systemic parental toxicity and 45 mg/kg bw/d (8.6 mg Li+/kg bw/d) for reproductive toxicity and fetal toxicity. Target organ changes were consistently observed in liver (cytoplasmic rarefaction) and kidney (dilated tubuli). In the key developmental toxicity (OECD TG 414) study in rats, doses given by oral gavage were 10, 30 and 90 mg/kg bw/d (1.9, 5.7 and 17.1 mg Li+/kg bw/d) was investigated resulting in NO(A)ELs of 30 mg/kg bw/d (5.7 mg Li+/kg bw/d) (maternal toxicity) and 90 mg/kg bw/d (17 mg Li+/kg bw/d) (fetal toxicity and teratogenicity). The highest dose of 90 mg/kg bw/day resulted in clear signs of toxicity and peak plasma concentrations at the toxic range (>1.0 mEq lithium/L). Toxic effects of lithium carbonate were not seen in the reproductive and developmental organs. No adverse effects on sperm (total motility, progressive motility and morphology of testicular and cauda epididymal sperm) were observed in the two-generation rat reproduction toxicity study. There was also no impact on fertility indices or on litter sizes in this study, nor were there any fetal effects in the two-generation reproduction toxicity and developmental toxicity study at doses causing already systemic toxicity in the dams. Secondary effects such as decreased weight (gain) and food consumption were reported in the developmental toxicity study. The absence of any reproductive/developmental findings at dose levels causing clear systemic toxicity in the test animals in these key mammalian studies, does not suggest an immediate concern for possible human reproductive or developmental toxicity effects from exposure to lithium during drug use.
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Affiliation(s)
- Koen Van Deun
- Reflector Consulting BV, Gasthuisstraat 26, 2400, Mol, Belgium; GNS Consult AG, Konstanzerstrasse 19, 8274, Tägerwilen, Switzerland.
| | - H Hatch
- Livent Commercial Road, CH62 3NL, Bromborough, Wirral, United Kingdom
| | - S Jacobi
- Albemarle Europe SRLRue du Bosquet 9, 1348, Louvain-La-Neuve, Belgium
| | - W Köhl
- KoehlConsult, Wassergasse 6, 67685, Erzenhausen, Germany
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Lewetag R, Hornyik T, Jacobi S, Moss R, Pilia N, Menza M, Perez-Feliz S, Bode C, Seemann G, Odening KE. Electro-mechanical and mechano-electrical interactions in healthy and drug-induced LQTS rabbit hearts. Europace 2021. [DOI: 10.1093/europace/euab116.578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): German Research Foundation
Background
Electrical and mechanical heterogeneities and their interactions (electro-mechanical and mechano-electrical coupling; EMC / MEC) are essential for normal cardiac function. Alterations in these can result in increased arrhythmia formation.
Purpose
With this study, we aim to investigate EMC and MEC under physiological and pathological conditions to better understand their roles in arrhythmia development.
Methods
Multi-channel ECG and TPM-MRI were used to measure regional differences in EMC in healthy ("control") and IKr-blocker E-4031 induced acute LQTS ("E-4031") rabbit hearts in vivo. MEC was studied in both groups by acutely changing mechanical function (increased preload by 6 ml/kg BW bolus of NaCl).
Results
In acute LQTS hearts (E-4031 10µg/kg bolus + 1µg/(kg*min) iv), cardiac repolarization was markedly prolonged compared to healthy controls, (p < 0.0001; n = 13), with increased QT-dispersion (Max-Min), a marker for regional heterogeneity of repolarization (p < 0.01; n = 13).
Changing electrical function by E-4031 resulted in changes of mechanical features (EMC): in acute LQTS hearts, diastolic longitudinal velocity (Vz) was reduced in all basal (p = 0.003; n = 19) and 4/6 mid segments (p = 0.006; n = 19). Longitudinal diastolic TTP was prolonged significantly in 5/6 basal and 4/6 mid segments by E-4031. These alterations led to an increased apicobasal heterogeneity of longitudinal contraction duration (basal-apical Vz_dia_TTP [ms] 2.9 ± 10.6 vs. 21.1 ± 21.3; p = 0.01; n = 9).
Increased preload acutely prolonged QTc in both "control" and "E-4031" hearts (‘control’ 156.6 ± 11.6 to 198.3 ± 20.3; p < 0.0001 vs. ‘E-4031’ 193.9 ± 19.6 to 256.0 ± 37.5; p < 0.0001; n = 13) (MEC). This effect was more pronounced in "E-4031" acute LQTS hearts than in healthy hearts (Figure 1; delta QTc [ms] ‘control’ 41.6 ± 14.9 vs. ‘E4031’ 62.1 ± 32.1; p < 0.006, n = 13). QT-dispersion (Max-Min) was increased significantly upon mechanical change only in "E-4031" (‘E-4031’ 25.8 ± 5.5 to 32.7 ± 12.3; p < 0.03, n = 13).
Conclusion
E-4031-induced changes in electrical function resulted in marked alterations in mechanical features via EMC. Similarly, acute changes in mechanical function (increased preload) resulted in electrical changes via MEC. Importantly, QT-prolonging effects of acutely increased preload, as well as its effects on regional heterogeneity of repolarization, were more pronounced in E-4031-induced acute LQTS hearts, indicating that cardiac repolarization in LQTS may be more susceptible to acute MEC effects than in healthy hearts. Acute MEC effects may thus play an additional role in LQT-related arrhythmogenesis. Abstract Figure.
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Affiliation(s)
- R Lewetag
- University Heart Center Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - T Hornyik
- Bern University Hospital, Inselspital, Department of Cardiology and Department of Physiology, Bern, Switzerland
| | - S Jacobi
- University Heart Center Freiburg, Department of Pediatric Cardiology, Freiburg, Germany
| | - R Moss
- University Heart Center Freiburg, Institute for Experimental Cardiovascular Medicine, Freiburg, Germany
| | - N Pilia
- Karlsruhe Institute of Technology (KIT), Institute of Biomedical Engineering, Karlsruhe, Germany
| | - M Menza
- University Hospital of Freiburg, Department of Radiology, Freiburg, Germany
| | - S Perez-Feliz
- University Heart Center Freiburg, Institute for Experimental Cardiovascular Medicine, Freiburg, Germany
| | - C Bode
- University Heart Center Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - G Seemann
- University Heart Center Freiburg, Institute for Experimental Cardiovascular Medicine, Freiburg, Germany
| | - KE Odening
- Bern University Hospital, Inselspital, Department of Cardiology and Department of Physiology, Bern, Switzerland
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Schanze N, Jacobi S, Höfig C, Mittag J, Köhrle J. Effects of repeated 3-T1AM treatment on thyrocytes in mice. Exp Clin Endocrinol Diabetes 2015. [DOI: 10.1055/s-0035-1547744] [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: 10/23/2022]
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6
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Dinter J, Mühlhaus J, Jacobi S, Wienchol CL, Cöster M, Meister J, Höfig C, Müller A, Köhrle J, Grüters A, Krude H, Mittag J, Schöneberg T, Kleinau G, Biebermann H. New G protein coupled receptor targets for 3-iodotyronamine. Exp Clin Endocrinol Diabetes 2015. [DOI: 10.1055/s-0035-1547778] [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: 10/23/2022]
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Thielscher C, Antoni B, Driedger J, Jacobi S, Krol B. Geringe Korrelation von Krankenhausführern kann zu verwirrenden Ergebnissen führen. Gesundh ökon Qual manag 2013. [DOI: 10.1055/s-0033-1335362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
| | | | | | | | - B. Krol
- FOM Hochschule für Oekonomie und Management, Essen
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Herfel T, Jacobi S, Lin X, van Heugten E, Fellner V, Odle J. Stabilized rice bran improves weaning pig performance via a prebiotic mechanism. J Anim Sci 2013; 91:907-13. [PMID: 23307853 DOI: 10.2527/jas.2012-5287] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Stabilized rice bran (SRB) is classified as a "functional food" because of its prebiotic characteristics. With increasing grain prices and the pressure to remove antibiotics from swine diets because of concern over antibiotic resistance, SRB was investigated as a nursery diet ingredient with and without the addition of antibiotics (ANT). Two hundred pigs were weaned at 21 d of age, blocked by BW, and allotted to diets containing 0 or 10% SRB ± ANT according to a 2 × 2 factorial arrangement of treatments. Five animals were housed per pen throughout a 28-d growth period. At the end of the trial, 1 pig from each pen was euthanized for measurement of intestinal morphology. Antibiotic supplementation improved ADG by 6.4% during Phase 2 (d 14 to 28; P = 0.02), but other production variables were unaffected by ANT. During Phase 2 and cumulatively (d 0 to 28), the supplementation of SRB improved G:F by 10% in ANT-free pigs but not in pigs fed ANT (ANT × SRB, P < 0.03). Ileal histology revealed an increase in crypt depth of pigs fed the diet containing ANT plus SRB and corresponding decreases in villi:crypt associated with both ANT and SRB supplementation (P < 0.05). Intraepithelial lymphocytes were increased by 15% in pigs fed SRB without ANT, but were unaffected by SRB in pigs fed ANT (ANT x SRB, P = 0.003). Colonic bifidobacteria tended to increase with SRB supplementation (P < 0.10). Differences in ileal and cecal digesta short-chain fatty acid concentrations were not detected. In summary, SRB improved the efficiency of nutrient utilization in nursery diets lacking antibiotics and tended to increase intestinal bifidobacteria concentrations, indicating that SRB may exert beneficial prebiotic effects in weanling pigs.
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Affiliation(s)
- T Herfel
- Laboratory of Developmental Nutrition, North Carolina State University, Raleigh, NC 27695, USA
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Campbell J, Jacobi S, Liu Y, Robertson KH, Drayton J, Medina I, Polo J, Crenshaw J, Odle J. Evaluation of immunoglobulin G absorption from colostrum supplements gavaged to newborn piglets. J Anim Sci 2012; 90 Suppl 4:299-301. [DOI: 10.2527/jas.51544] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - S. Jacobi
- Laboratory of Developmental Nutrition, North Carolina State University, Raleigh, NC, 27695
| | - Y. Liu
- Laboratory of Developmental Nutrition, North Carolina State University, Raleigh, NC, 27695
| | | | - J. Drayton
- Laboratory of Developmental Nutrition, North Carolina State University, Raleigh, NC, 27695
| | - I. Medina
- Laboratory of Developmental Nutrition, North Carolina State University, Raleigh, NC, 27695
| | - J. Polo
- APC, Inc., Ankeny, IA, 50021
| | | | - J. Odle
- Laboratory of Developmental Nutrition, North Carolina State University, Raleigh, NC, 27695
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Abstract
Intraocular lenses (IOLs) have been implanted in adult equine eyes after cataract surgery. Foals and weanlings comprise a large proportion of those horses undergoing cataract surgery. Due to potential differences in the size and corneal curvature of the juvenile eye, it is not currently known whether implantation of adult IOLs is appropriate in foals and weanlings. The objective of the study was to measure the anterior chamber depth (ACD), central lens thickness (CLT), vitreous chamber depth (VCD), axial globe length (AGL) and corneal curvature of horses less than one year of age. The axial dimensions from one eye of 10 foals were measured using simultaneous A and B scan ultrasonography. The corneal curvature from one eye of 7 weanlings was determined using a modified photokeratometer. Ultrasonography revealed a mean ACD of 4.94 mm, mean CLT of 9.38 mm, mean VCD of 18.96 mm and mean AGL of 33.32 mm for the foals. The mean corneal curvature was 15.4 diopters (D). The mean ACD, CLT, VCD and AGL of the foals were less than the measurements reported in the literature for adult horses. The mean corneal curvature was similar to the values reported by some authors for adult horses. Due to the differences in axial dimensions between adult and juvenile eyes, an IOL that corrects vision in an adult horse might not adequately correct vision in a horse less than one year of age.
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Affiliation(s)
- W M Townsend
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
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11
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Affiliation(s)
- W M Townsend
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, MI, USA.
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Jacobi S, Soriano J, Moses E. BDNF and NT-3 Increase Velocity of Activity Front Propagation in Unidimensional Hippocampal Cultures. J Neurophysiol 2010; 104:2932-9. [DOI: 10.1152/jn.00002.2010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neurotrophins are known to promote synapse development as well as to regulate the efficacy of mature synapses. We have previously reported that in two-dimensional rat hippocampal cultures, brain-derived neurotrophic factor (BDNF) and neurotrophin-3 significantly increase the number of excitatory input connections. Here we measure the effect of these neurotrophic agents on propagating fronts that arise spontaneously in quasi-one-dimensional rat hippocampal cultures. We observe that chronic treatment with BDNF increased the velocity of the propagation front by about 30%. This change is attributed to an increase in the excitatory input connectivity. We analyze the experiment using the Feinerman–Golomb/Ermentrout–Jacobi/Moses–Osan model for the propagation of fronts in a one-dimensional neuronal network with synaptic delay and introduce the synaptic connection probability between adjacent neurons as a new parameter of the model. We conclude that BDNF increases the number of excitatory connections by favoring the probability to form connections between neurons, but without significantly modifying the range of the connections (connectivity footprint).
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Affiliation(s)
- Shimshon Jacobi
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel; and
| | - Jordi Soriano
- Departament Estructura i Constituents de la Matería, Facultat de Física, Universitat de Barcelona, Barcelona, Spain
| | - Elisha Moses
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel; and
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13
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Abstract
The neurotrophic factors brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) have been shown to promote excitatory and inhibitory synapse development. However, a quantitative analysis of their influence on connectivity has proven in general difficult to achieve. In this work we use a novel experimental approach based on percolation concepts that provides a quantification of the average number of connections per neuron. In combination with electrophysiological measurements, we characterize the changes in network connectivity induced by BDNF and NT-3 in rat hippocampal cultures. We show that, on the one hand, BDNF and NT-3 accelerate the maturation of connectivity in the network by about 17 h. On the other hand, BDNF and NT-3 increase the number of excitatory input connections by a factor of about two, but without modifying the number of inhibitory input connections. This scenario of a dominant effect on the excitation is supported by the analysis of spontaneous population bursts in cultures treated with either BDNF or NT-3, which show burst amplitudes that are insensitive to the blockade of inhibition. A leaky integrate-and-fire model reproduces the experimental results well.
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Affiliation(s)
- Shimshon Jacobi
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, 76100 Israel
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14
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Jacobi S, Moses E. Variability and corresponding amplitude-velocity relation of activity propagating in one-dimensional neural cultures. J Neurophysiol 2007; 97:3597-606. [PMID: 17344374 DOI: 10.1152/jn.00608.2006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [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: 11/22/2022] Open
Abstract
We investigate the propagation of neural activity along one-dimensional rat hippocampal cultures patterned in lines over multielectrode arrays. Activity occurs spontaneously or is evoked by local electrical or chemical stimuli, with different resulting propagation velocities and firing rate amplitudes. A variability of an order of magnitude in velocity and amplitude is observed in spontaneous activity. A linear relation between velocity and amplitude is identified. We define a measure for neuron activation synchrony and find that it correlates with front velocity and is higher for electrically evoked fronts. We present a model that explains the linear relation between amplitude and velocity, which highlights the role of synchrony. The relation to current models for signal propagation in neural media is discussed.
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Affiliation(s)
- Shimshon Jacobi
- Department of Physics of Complex Systems, The Weizmann Institute of Science, P.O. Box 26, Rehovot 76100, Israel.
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Bitsch A, Jacobi S, Melber C, Wahnschaffe U, Simetska N, Mangelsdorf I. REPDOSE: A database on repeated dose toxicity studies of commercial chemicals—A multifunctional tool. Regul Toxicol Pharmacol 2006; 46:202-10. [PMID: 16935401 DOI: 10.1016/j.yrtph.2006.05.013] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [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: 08/03/2004] [Indexed: 10/24/2022]
Abstract
A database for repeated dose toxicity data has been developed. Studies were selected by data quality. Review documents or risk assessments were used to get a pre-screened selection of available valid data. The structure of the chemicals should be rather simple for well defined chemical categories. The database consists of three core data sets for each chemical: (1) structural features and physico-chemical data, (2) data on study design, (3) study results. To allow consistent queries, a high degree of standardization categories and glossaries were developed for relevant parameters. At present, the database consists of 364 chemicals investigated in 1018 studies which resulted in a total of 6002 specific effects. Standard queries have been developed, which allow analyzing the influence of structural features or PC data on LOELs, target organs and effects. Furthermore, it can be used as an expert system. First queries have shown that the database is a very valuable tool.
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Affiliation(s)
- A Bitsch
- Fraunhofer Institute of Toxicology and Experimental Medicine, Department Chemical Risk Assessment, Nikolai-Fuchs-Str. 1, D-30625 Hannover, Germany.
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Bitsch A, Jacobi S, Melber C, Wahnschaffe U, Simetska N, Mangelsdorf I. REPDOSE: A database on repeated dose toxicity studies of commercial chemicals. Toxicol Lett 2006. [DOI: 10.1016/j.toxlet.2006.07.129] [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: 10/24/2022]
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Overs M, Jacobi S, Chi L, Fix M, Fuchs H, Galla H, Schäfer H. Assembly of new dioxygenated alkyl alkanoates at the air–water interface. Colloids Surf A Physicochem Eng Asp 2002. [DOI: 10.1016/s0927-7757(01)00964-5] [Citation(s) in RCA: 6] [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] [Indexed: 10/18/2022]
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Taylor SE, Desbat B, Blaudez D, Jacobi S, Chi LF, Fuchs H, Schwarz G. Structure of a fusion peptide analogue at the air-water interface, determined from surface activity, infrared spectroscopy and scanning force microscopy. Biophys Chem 2000; 87:63-72. [PMID: 11036970 DOI: 10.1016/s0301-4622(00)00182-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [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: 11/21/2022]
Abstract
We have investigated a point mutant of the HIV-1 fusion peptide in a compressed monolayer at the air-water interface. A variety of surface sensitive techniques were applied to study structural features under conditions mimicking the hydrophobic/hydrophilic environment of a biomembrane. Possible partitioning into the aqueous bulk phase and molecular areas were examined by surface activity based mass conservation plots. This shows that the peptide is practically fully accumulated in the interface. Secondary structure and orientation was analyzed by means of polarized infrared reflectivity. Brewster angle microscopy and scanning force microscopy contributed nanostructural images. At low surface pressures the molecules form anti-parallel beta-sheets lying flat on the interface. Upon a moderate increase of the lateral pressure a flat beta-turn structure appears with inter- and intramolecular H-bonds. We also observed aggregates forming fingerprint-like structures with a diameter of approximately double the hydrophobic length of a beta-turn conformation. Beyond approximately 18 mN m(-1) the beta-turns straighten up. The lowest measured tilt angle was 45 degrees at 36 mN m(-1).
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Affiliation(s)
- S E Taylor
- Department of Biophysical Chemistry, Biocenter of the University, Basel, Switzerland
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Weiner ML, Freeman C, Trochimowicz H, de Gerlache J, Jacobi S, Malinverno G, Mayr W, Regnier JF. 13-week drinking water toxicity study of hydrogen peroxide with 6-week recovery period in catalase-deficient mice. Food Chem Toxicol 2000; 38:607-15. [PMID: 10942322 DOI: 10.1016/s0278-6915(00)00048-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [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: 10/17/2022]
Abstract
A GLP OECD guideline study was conducted to evaluate the subchronic toxicity of hydrogen peroxide (HP) when administered continuously in the drinking water of catalase-deficient (C57BL/6N) mice and reversibility of toxic effects. Groups of mice (15/sex/group) received solutions of 0, 100, 300, 1000 or 3000 ppm HP in distilled water for 13 weeks; five/sex/group continued on untreated distilled water for an additional 6 weeks. Animals drinking 3000 ppm HP exhibited depressed water and food consumption and body weight. Females drinking 1000 ppm HP had reduced water consumption with intermittent effects on food consumption, but no body weight effects. HP administration did not produce any mortality, clinical signs, hematological effects or organ weight effects on brain, liver, kidneys, adrenals, testes, heart or spleen. Total protein and globulin were depressed among high dose males. Mild to minimal duodenal mucosal hyperplasia was noted in animals receiving 1000 and 3000 ppm HP and one male receiving 300 ppm for 13 weeks. There were no other histopathological findings. All effects noted during the treatment period, including the duodenal hyperplasia, were reversible during the 6-week recovery period. Females dosed with 300-3000 ppm HP during the treatment period showed increased water consumption during the recovery period. The no-observed-effect level (NOEL), based on duodenal mucosal hyperplasia, is 100 ppm in drinking water or 26 and 37 mg/kg/day HP, respectively, for males and females.
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Affiliation(s)
- M L Weiner
- FMC Corporation, Princeton, NJ 08543, USA.
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20
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Greim H, Ahlers J, Bias R, Broecker B, Hollander H, Gelbke HP, Jacobi S, Klimisch HJ, Mangelsdorf I, Mayr W. Assessment of structurally related chemicals: toxicity and ecotoxicity of acrylic acid and acrylic acid alkyl esters (acrylates), methacrylic acid and methacrylic acid alkyl esters (methacrylates). Chemosphere 1995; 31:2637-2659. [PMID: 7663949 DOI: 10.1016/0045-6535(95)00136-v] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
BUA compiled the available data on toxicity and ecotoxicity for several acrylic and methacrylic acid esters and their corresponding acids. A comparison of these data revealed a qualitative similarity in the toxicological and ecotoxicological properties of the compounds considered. The data indicate that methacrylates are less reactive than the corresponding acrylates.
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Affiliation(s)
- H Greim
- GSF Institut für Toxikologie, Oberschleissheim, Germany
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21
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Molina H, Brenner C, Jacobi S, Gorka J, Carel JC, Kinoshita T, Holers VM. Analysis of Epstein-Barr virus-binding sites on complement receptor 2 (CR2/CD21) using human-mouse chimeras and peptides. At least two distinct sites are necessary for ligand-receptor interaction. J Biol Chem 1991; 266:12173-9. [PMID: 1712014] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The predicted amino acid sequence of human complement receptor 2 (CR2, CD21, C3d,g/Epstein-Barr virus receptor) and its genetic murine homologue are approximately 70% identical. The sequence of each consists of a linear array of 60-70 amino acid repeats designated short consensus repeats (SCRs). Although they share significant sequence identity, a major difference in the activities of these two proteins has been believed to be the ability of human, but not mouse, CR2 to mediate Epstein-Barr virus (EBV) infection of B lymphocytes. In order to formally address this question and to directly compare the activities of the CR2 protein of each species, we have expressed recombinant mouse CR2 (rMCR2) in a human K562 erythroleukemia cell line background. We have found that rMCR2 reacts with two previously described rat anti-MCR2 monoclonal antibodies (mAbs), 7G6 and 7E9, but not mAb 8C12, which recognizes only mouse complement receptor 1. rMCR2 rosettes with erythrocytes bearing mouse and human C3d,g and binds glutaraldehyde cross-linked human C3d,g with a similar Kd as human CR2 (HCR2). rMCR2 does not bind EBV. By using this observation and constructing chimeras bearing portions of MCR2 on a HCR2 background, we have been able to define unique sequences in HCR2 SCRs 1 and 2 important in the interaction with both mAb OKB7, which blocks EBV binding and infection, and with EBV. In addition, by using blocking peptides derived from HCR2 sequence, we have identified a second distinct region in SCR2 important in EBV binding. Therefore, within the first two SCRs of HCR2 are multiple distinct sites of interaction with EBV and with mAb OKB7.
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Affiliation(s)
- H Molina
- Howard Hughes Medical Institute Laboratories, Washington University School of Medicine, St. Louis, Missouri 63110
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Molina H, Brenner C, Jacobi S, Gorka J, Carel J, Kinoshita T, Holers V. Analysis of Epstein-Barr virus-binding sites on complement receptor 2 (CR2/CD21) using human-mouse chimeras and peptides. At least two distinct sites are necessary for ligand-receptor interaction. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)98876-9] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Abstract
The 1H-benzotriazole-carboxylic acid esters under investigation were almost - with the exception of the tert.-butylester - completely hydrolyzed by rat liver microsomes. Some substrates were metabolically oxidized to a very small extent (less than 1%) yielding small amounts of possibly toxic metabolites after inhibition of the esterases with paraoxone.
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Affiliation(s)
- S Jacobi
- Institut für Pharmazeutische Chemie, Johann Wolfgang Goethe-Universität, Frankfurt am Main
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Abstract
The 1H-benzotriazolecarboxylic acids 1 and 2 were stable towards oxidative metabolism as well in vitro as in vivo. In the in vivo studies 2.25% of the ester glucuronide of 1H-benzotriazole-5-carboxylic acid was found in urine.
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Schleisiek K, Aberle J, Jacobi S, Karsten G, Rahn A, Schmidt L, Vanmassenhove G, Verwimp A. Mol 7C experiments on local fault propagation in irradiated LMFBR fuel subassemblies. Nuclear Engineering and Design 1987. [DOI: 10.1016/0029-5493(87)90091-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Jacobi S, Hoffmann G, Klein D, Schmitz G. Core surveillance of liquid metal fast breeder reactors by delayed neutron signals. Nuclear Engineering and Design 1987. [DOI: 10.1016/0029-5493(87)90092-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Hoffmann H, Jacobi S. [Hydrolysis of the antiemetic alizapride]. Arzneimittelforschung 1984; 34:1714-5. [PMID: 6543307] [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: 04/05/2023]
Abstract
First order rate constants of the hydrolysis of N-[(1-allyl-2-pyrrolidinyl)-methyl]-6-methoxy-1H-benzotriazole-5-carboxa mide (alizapride, Vergentan) in acid and alkaline medium were determined. The activation energy observed in alkaline solution was 60.3 kJ X mol-1. The substance was not hydrolized in vitro by esterase, liver homogenate and plasma.
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Cartwright D, Manent G, Chenebault P, Sesuy R, De Nontaignac E, Diggle W, Johnson F, Findlay J, Glauner W, Jacobi S, Feuerstein H, Relic M. Fission-product measurements in the SCARABEE mono and seven-pin loss-of-coolant experiments. Nuclear Engineering and Design 1980. [DOI: 10.1016/0029-5493(80)90201-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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