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Stroope S, Walton R, Mochel JP, Yuan L, Enders B. Retrospective Evaluation of Clinical Bleeding in Dogs With Anticoagulant Rodenticide Toxicity—A Multi-Center Evaluation of 62 Cases (2010–2020). Front Vet Sci 2022; 9:879179. [PMID: 35677932 PMCID: PMC9168750 DOI: 10.3389/fvets.2022.879179] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/15/2022] [Indexed: 11/22/2022] Open
Abstract
Objective To evaluate the most common locations of hemorrhage in dogs diagnosed with anticoagulant rodenticide intoxication. Animals Dogs presenting with hemorrhage secondary to anticoagulant rodenticide intoxication between at two university veterinary teaching hospitals. Procedures Medical records were searched from the years 2010 through 2020 and all records from dogs treated for hemorrhage secondary to anticoagulant rodenticide intoxication were reviewed. Dogs were diagnosed with anticoagulant rodenticide intoxication based on the combination of known exposure and prolonged coagulation testing, including prothrombin and activated thromboplastin time, or based on gas chromatography-mass spectrometry (GCMS). The diagnosis of hemorrhage was made based on physical exam findings, point-of-care ultrasound findings or radiography. Results Sixty-two dogs met the inclusion criteria and were included in the study. The most common sites of hemorrhage included: pleural space (hemothorax 37%), pulmonary parenchyma (24%), abdomen (24%), skin/subcutaneous (21%), gastrointestinal tract (18%), pericardium (13%), oral cavity (13%), nasal cavity (11%), ocular (8%), and urinary tract (7%). Overall, forty-five dogs (73%) had evidence of cutaneous or mucosal hemorrhage while thirty-three (53%) of dogs had evidence of cavitary hemorrhage. Forty-five percent of dogs had hemorrhage noted at only one site, while 55% experienced hemorrhage at more than one site. The location of hemorrhage and total number of hemorrhagic sites was not associated with survival or transfusion requirement. Conclusions and Clinical Relevance In conclusion, this study highlights that dogs with anticoagulant rodenticide intoxication present with diverse locations of hemorrhage and the majority of dogs had non-cavitary hemorrhage noted.
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Affiliation(s)
- Sarah Stroope
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Rebecca Walton
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
- *Correspondence: Rebecca Walton
| | - Jonathan Paul Mochel
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Lingnan Yuan
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Brittany Enders
- College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
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Cole AL, Croce A, Harvey JB, Enders B, Perry K, Hedgespeth BA, Terumi Negrão Watanabe T. Pathology in Practice. J Am Vet Med Assoc 2022; 259:1-4. [PMID: 35587905 DOI: 10.2460/javma.21.07.0352] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In collaboration with the American College of Veterinary Pathologists.
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Affiliation(s)
- Allysa L Cole
- College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL
| | - Andelience Croce
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - Janice B Harvey
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - Brittany Enders
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - Kayla Perry
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - Barry A Hedgespeth
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - Tatiane Terumi Negrão Watanabe
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
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3
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Enders B, Olby N, Mariani CL. Use of posaconazole for treatment of disseminated protothecosis in a dog. Vet rec case rep 2017. [DOI: 10.1136/vetreccr-2016-000350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Brittany Enders
- Department of Clinical SciencesNCSU College of Veterinary MedicineRaleighNorth CarolinaUSA
| | - Natasha Olby
- Department of Clinical SciencesNCSU College of Veterinary MedicineRaleighNorth CarolinaUSA
| | - Christopher L Mariani
- Department of Clinical SciencesNCSU College of Veterinary MedicineRaleighNorth CarolinaUSA
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Abstract
Ptychography is now a well-established X-ray microscopy tool for synchrotron end-stations equipped with a scanning stage and a pixelated detector. Ptychographic phasing algorithms use information from coherent diffraction to deliver quantitative images of the specimen at a resolution higher than the scanning resolution. These algorithms have traditionally been implemented in software on a per-instrument basis in various degrees of user-friendliness and sophistication. Here, we present Ptypy, a ptychography software written with the intention to serve as a framework across the diverse sets of available instruments and usage cases. A distinctive feature of the software is its formalism, which provides a convenient abstraction of the physical model, thus allowing for concise algorithmic implementations and portability across set-up geometries. We give an overview of the supported usage cases, explain the abstraction layer and design principles, and provide a step-by-step guide describing how an algorithm may be realized in a concise and readable manner. The software capabilities are illustrated with reconstructions from visible light and X-ray data.
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Affiliation(s)
- B Enders
- Department of Physics & Institute of Medical Engineering, Technical University of Munich, 85747 Garching, Germany; Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley 94720, CA, USA
| | - P Thibault
- School of Physics and Astronomy , University of Southampton, Southampton SO17 1BJ , , UK
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5
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Zanette I, Enders B, Dierolf M, Thibault P, Gradl R, Diaz A, Guizar-Sicairos M, Menzel A, Pfeiffer F, Zaslansky P. Ptychographic X-ray nanotomography quantifies mineral distributions in human dentine. Sci Rep 2015; 5:9210. [PMID: 25790969 PMCID: PMC4366856 DOI: 10.1038/srep09210] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [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: 10/12/2014] [Accepted: 01/28/2015] [Indexed: 11/25/2022] Open
Abstract
Bones are bio-composites with biologically tunable mechanical properties, where a polymer matrix of nanofibrillar collagen is reinforced by apatite mineral crystals. Some bones, such as antler, form and change rapidly, while other bone tissues, such as human tooth dentine, develop slowly and maintain constant composition and architecture for entire lifetimes. When studying apatite mineral microarchitecture, mineral distributions or mineralization activity of bone-forming cells, representative samples of tissue are best studied at submicrometre resolution while minimizing sample-preparation damage. Here, we demonstrate the power of ptychographic X-ray tomography to map variations in the mineral content distribution in three dimensions and at the nanometre scale. Using this non-destructive method, we observe nanostructures surrounding hollow tracts that exist in human dentine forming dentinal tubules. We reveal unprecedented quantitative details of the ultrastructure clearly revealing the spatially varying mineralization density. Such information is essential for understanding a variety of natural and therapeutic effects for example in bone tissue healing and ageing.
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Affiliation(s)
- I Zanette
- 1] Physik-Department &Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany [2] Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, United Kingdom
| | - B Enders
- Physik-Department &Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany
| | - M Dierolf
- Physik-Department &Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany
| | - P Thibault
- 1] Physik-Department &Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany [2] Department of Physics &Astronomy, University College London, WC1E 6BT London, United Kingdom
| | - R Gradl
- Physik-Department &Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany
| | - A Diaz
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | | | - A Menzel
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - F Pfeiffer
- 1] Physik-Department &Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany [2] Institut für diagnostische und interventionelle Radiologie, Klinikum rechts der Isar, Technische Universität München, 81675 München, Germany
| | - P Zaslansky
- Julius Wolff Institute and Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, 13353 Berlin, Germany
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6
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Kocken CH, Hundt E, Knapp B, Brazel D, Enders B, Narum DL, Wubben JA, Thomas AW. Immunization of Aotus monkeys with recombinant Plasmodium falciparum hybrid proteins does not reproducibly result in protection from malaria infection. Infect Immun 1998; 66:373-5. [PMID: 9423884 PMCID: PMC107908 DOI: 10.1128/iai.66.1.373-375.1998] [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: 02/05/2023] Open
Abstract
Plasmodium falciparum antigens SERP, HRPII, MSAI, and 41-3 have shown promise as vaccine components. This study aimed at reproducing and extending previous results using three hybrid molecules. Antibody responses were reproduced in Aotus monkeys, but solid protection from a P. falciparum blood-stage challenge that showed an unintendedly enhanced pathogenicity was not observed.
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Affiliation(s)
- C H Kocken
- Biomedical Primate Research Centre, Department of Parasitology, Rijswijk, The Netherlands.
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7
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Enssle K, Enders B, Kurrle R, Lauffer L, Schorlemmer HU, Dickneite G, Kanzy EJ, Seiler FR. Biology of natural and recombinant soluble interleukin-4 receptor. Behring Inst Mitt 1995:103-17. [PMID: 7575346] [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] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- K Enssle
- Research Laboratories of Behringwerke AG, Marburg, Germany
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8
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Sinoway LI, Smith MB, Enders B, Leuenberger U, Dzwonczyk T, Gray K, Whisler S, Moore RL. Role of diprotonated phosphate in evoking muscle reflex responses in cats and humans. Am J Physiol 1994; 267:H770-8. [PMID: 8067433 DOI: 10.1152/ajpheart.1994.267.2.h770] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.8] [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] [Indexed: 01/28/2023]
Abstract
Lactic acid and H+ evoke muscle reflexes that raise sympathetic nerve activity. Whether these substances are direct afferent stimulants or markers for the acidification of other substances is unknown. Diprotonated phosphate (H2PO4-), a possible mediator of fatigue, increases as the cell acidifies and phosphate is produced. Its role in evoking muscle reflexes is unknown. We used 31P-nuclear magnetic resonance to measure forearm muscle H+ and H2PO4- and microneurography to measure muscle sympathetic nerve activity (MSNA, peroneal nerve) during a handgrip protocol designed to dissociate H+ from H2PO4-. Ischemic handgrip (50% maximal voluntary contraction x 2 min) was followed by a 1-min rest period during which the muscle was freely perfused. This was followed by a second bout of ischemic handgrip and a 5-min recovery. In seven of eight subjects, MSNA correlated with H2PO4-, whereas it correlated with pH in only one subject. To determine whether muscle reflex responses are evoked by H+, lactic acid, monoprotonated phosphate (HPO4(2-), or H2PO4-, we injected H+, lactate, H2PO4- [all 50 mM in 10 mM N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) buffered to pH 6], and HPO4(2-) (50 mM, pH 7.5 in 10 mM HEPES) into the arterial supply of the triceps surae of the cat (n = 9) as we measured mean arterial blood pressure (MAP). H2PO4- increased MAP more than HPO4(2-), H+, or lactate (27.1 +/- 3.7 vs. 5.0 +/- 1.3, 4.6 +/- 3.1, and 7.7 +/- 3.2 rise in mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- L I Sinoway
- Department of Medicine, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033
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9
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McClain J, Hardy C, Enders B, Smith M, Sinoway L. Limb congestion and sympathoexcitation during exercise. Implications for congestive heart failure. J Clin Invest 1993; 92:2353-9. [PMID: 8227351 PMCID: PMC288417 DOI: 10.1172/jci116840] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.5] [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: 01/29/2023] Open
Abstract
During static exercise, heart failure (HF) subjects activate the sympathetic nervous system differently than normal controls. HF causes metaboreceptor desensitization with either enhanced mechanoreceptor activity or central command. In this report, we examined whether increased muscle interstitial pressure, as seen in HF, augments other neural systems. We measured muscle sympathetic nerve activity (MSNA; peroneal nerve) in 10 normals during static exercise (40% maximal voluntary grip) and posthandgrip circulatory arrest (PHG-CA). This was repeated after venous congestion (VC; cuff inflation to 90 mmHg). VC increased forearm volume (plethysmography) by 4.7%. MSNA responses to exercise were greater after VC (150.5 +/- 41.8 vs. 317.3 +/- 69.9 arbitrary units; P < 0.01). However, MSNA responses during PHG-CA were not affected by VC, and 31P nuclear magnetic resonance (n = 5) demonstrated no effect of VC on pH or H2PO4-. Similar effects of VC on MSNA were noted after ischemic exercise (n = 7), excluding flow alterations as the explantation. VC probably sensitized mechanically sensitive afferents since MSNA during involuntary biceps contractions increased after VC (n = 6), and skin sympathetic nerve responses during handgrip, an index of central command, were not increased by VC (n = 6).
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Affiliation(s)
- J McClain
- Division of Cardiology, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033
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10
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Brachmann J, Schöls W, Beyer T, Montero M, Enders B, Kübler W. Acute and chronic antiarrhythmic efficacy of d-sotalol in patients with sustained ventricular tachyarrhythmias. Eur Heart J 1993; 14 Suppl H:85-7. [PMID: 8293757 DOI: 10.1093/eurheartj/14.suppl_h.85] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [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: 01/29/2023] Open
Abstract
To evaluate the clinical efficacy of d-sotalol, 84 patients with a history of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF), who had inducible sustained VT/VT at baseline electrophysiologic study (EPS), were investigated after intravenous (IV) d-sotalol (1.5-2.5 mg.kg-1). A total of 29 additional patients received only oral d-sotalol, (400-600 mg.day-1). Acute success of antiarrhythmic therapy was defined as suppression of inducible sustained VT/VF. The overall success rate of IV d-sotalol was 38% (32/84) after a mean of 4.3 drugs failed to suppress inducibility. A 78% success rate (31/40) was demonstrated in patients who were also assessed after oral d-sotalol. Torsade de pointes type VT was seen in one patient. After 1 year, only 16% of patients with a positive EPS had a recurrence compared to 43% of patients with a negative EPS (P < 0.05). Estimated survival rates were 95 and 88% after 1 and 2 years of follow-up, respectively. Only five of 56 patients discontinued d-sotalol therapy because of adverse effects. IV d-sotalol appears to be an effective antiarrhythmic agent. Its long-term efficacy is predictable on the basis of therapy guided by electrophysiologic testing in patients with refractory ventricular tachyarrhythmias. The efficacy of d-sotalol seems comparable to that reported for d,l-sotalol.
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Affiliation(s)
- J Brachmann
- Medical University Hospital, Department of Cardiology, Heidelberg, Germany
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11
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Perraut R, Hundt E, Garraud O, Enders B, Gysin J. Comparison of the effects of adjuvants and adjuvant doses on the quantitative and qualitative antibody response to selected antigens in New World squirrel monkeys Saimiri sciureus. Vaccine 1993; 11:730-6. [PMID: 8393605 DOI: 10.1016/0264-410x(93)90257-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [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: 01/30/2023]
Abstract
The effect of several adjuvants and of adjuvant doses on the quantitative and qualitative antibody response to tetanus toxoid (TT) and a recombinant herpes simplex virus peptide (HSVgD) was evaluated in the New World monkey Saimiri sciureus. All adjuvant formulations were effective in inducing a strong antibody response to these antigens. The qualitative antibody response, as defined by monoclonal antibodies 3A2/G6 and 4G3/B5, was determined. Only 3A2/G6+ antibodies were induced after immunization with HSVgD irrespective of the adjuvant used and after immunization with TT alone. However, both types of antibodies were induced against TT in the presence of the adjuvants tested. These data suggest that both adjuvant and antigens can intervene in driving the quality of the antibody response induced after immunization. Strong antibody response to TT was induced at any adjuvant dose tested, suggesting that lower doses are as effective as higher doses. These findings can have implications on the design of future trials of vaccine candidate constructs in monkeys and eventually in human beings.
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Affiliation(s)
- R Perraut
- Laboratoire d'Immunologie Parasitaire, Institut Pasteur de la Guyane Francaise, Cayenne
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12
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Abstract
On the basis of investigations of the malarial blood-stage antigens SERP, HRPII, and MSAI from Plasmodium falciparum, we chose two Escherichia coli-expressed hybrid proteins containing selected partial sequences of these antigens. Antibodies raised against both hybrid proteins in rabbits and Aotus monkeys recognize the corresponding P. falciparum polypeptides. In two independent trials with 13 animals, immunization of Aotus monkeys with either of the two hybrid proteins administered in a well-tolerated oil-based formulation protected the animals from an experimental P. falciparum infection.
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Affiliation(s)
- B Knapp
- Research Laboratories, Behringwerke AG, Marburg, Germany
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13
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Williams GD, Enders B, Smith MB. Effect of pH and inorganic phosphate on creatine kinase inactivation: an in vitro 31P NMR saturation-transfer study. Biochem Int 1992; 26:35-42. [PMID: 1616495] [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: 12/27/2022]
Abstract
The pseudo-first-order rate constant of rabbit muscle creatine kinase (CK), in the direction of ATP synthesis (kf), was determined by saturation-transfer 31P NMR. When pH was varied between 6.0 and 7.4, kf increased linearly at both 20 degrees C and 37 degrees c. The corresponding flux is very small between pH 6.0 and 6.5, in contrast to previous studies. Up to 50 h exposure of the CK enzyme to high concentrations of inorganic phosphate (Pi), a known inhibitor in certain situations, had negligible effect on enzymatic flux in the physiological pH range. Thus under in vivo conditions, such as in stroke, where pH falls as low as 6.2 and Pi rises to high levels, the rate of the CK reaction may be severely reduced due to pH but not due to high Pi concentrations.
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Affiliation(s)
- G D Williams
- Department of Radiology, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey 17033
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Abstract
Susceptible Aotus monkeys were immunized with Escherichia coli-derived fusion proteins containing partial sequences of the proteins MSAI, SERP, HRPII and with a group of three recombinant antigens isolated by screening with an antiserum raised against the protective 41 kDa protein band. HRPII, the combination of the fusion proteins of the 41 kDa group and a mixture of two sequences of SERP conferred significant protection against a challenge infection with Plasmodium falciparum blood stages. Based on the protective capacity of these recombinant antigens we have expressed two hybrid proteins (MS2/SERP/HRPII and SERP/MSAI/HRPII) in E. coli containing selected partial sequences. In two independent immunization trials it was shown that immunization of Aotus monkeys with either of the two hybrid proteins can protect the animals from an experimental P. falciparum infection.
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Affiliation(s)
- B Enders
- Research Laboratories of Behringwerke AG, Marburg, Germany
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Abstract
The genus Aotus spp. (owl monkey) is one of the WHO recommended experimental models for Plasmodium falciparum blood stage infection, especially relevant for vaccination studies with asexual blood stage antigens of this parasite. For several immunization trials with purified recombinant merozoite/schizont antigens, the susceptible Aotus karyotypes II, III, IV and VI were immunized with Escherichia coli derived fusion proteins containing partial sequences of the proteins MSAI (merozoite surface antigen I), SERP (serine-stretch protein) and HRPII (histidine alanine rich protein II) as well as with a group of recombinant antigens obtained by an antiserum raised against a protective 41 kD protein band. The subcutaneous application (3x) of the antigen preparations was carried out in intact animals followed by splenectomy prior to challenge, in order to increase the susceptibility of the experimental hosts to the parasite. A partial sequence of HRPII, the combination of three different fusion proteins of the 41 kD group and a mixture of two sequences of SERP in the presence of a modified Al(OH)3 adjuvant conferred significant protection against a challenge infection with P. falciparum blood stages (2-5 x 10(6)) i. RBC). Monkeys immunized with the MS2-fusion protein carrying the N-terminal part of the 195 kD precursor of the major merozoite surface antigens induced only marginal protection showing some correlation between antibody titer and degree of parasitaemia. Based on the protective capacity of these recombinant antigens we have expressed two hybrid proteins (MS2/SERP/HRPII and SERP/MSAI/HRPII) in E. coli containing selected partial sequences of SERP, HRPII and MSAI. Antibodies raised against both hybrid proteins in rabbits and Aotus monkeys recognize the corresponding schizont polypeptides. In two independent immunization trials using 13 animals (age 7 months to 3 years) we could show that immunization of Aotus monkeys with either of the two hybrid proteins administered in an oil-based well tolerated formulation protected the animals from a severe experimental P. falciparum (strain Palo Alto) infection.
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Affiliation(s)
- B Enders
- Behringwerke AG, Research Laboratories, Marburg, Germany
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Abstract
The development of coagulation disorders was studied in murine malaria. Plasmodium vinckei was chosen following an initial experiment because onset and duration of parasitemia were more suitable for hemostasiological studies than in the short-lasting infection, caused by P. berghei. Evaluation of the time courses of hematocrit, platelets, antithrombin (AT) III activity, Factor V activity and parasitemia showed a significant decrease in platelets, hematocrit, Factor V and AT III activity during the course of infection. The obtained data strongly suggest the development of a disseminated intravascular coagulation in mice during the terminal phase of murine malaria.
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17
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Knapp B, Hundt E, Enders B, Küpper HA. A recombinant hybrid protein as antigen for an anti-blood stage malaria vaccine. Behring Inst Mitt 1991:147-56. [PMID: 2049032] [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: 12/30/2022]
Abstract
Based on investigations on several blood stage antigens from Plasmodium falciparum we have expressed a hybrid protein in E. coli containing 262 amino acids of the serine-stretch protein SERP and 189 amino acids of the histidine alanine rich protein HRPII. Antibodies raised against the hybrid protein by immunization of rabbits and Aotus monkeys react with both corresponding schizont polypeptides. Two Aotus monkeys immunized with the SERP/HRPII hybrid protein showed only low parasitemias after challenge infection with P. falciparum, compared to the control group. The result suggests that hybrid proteins of this type may be the basis for the development of a malaria vaccine.
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Affiliation(s)
- B Knapp
- Research Laboratories of Behringwerke AG, Marburg, Germany
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18
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Clemens R, Bock HL, Enders B, Reiner G. Antithrombin III substitution affects survival rate in a murine malaria model. Parasitol Res 1989; 76:36-8. [PMID: 2533685 DOI: 10.1007/bf00931069] [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: 01/01/2023]
Abstract
The effect of AT III substitution on survival time was studied in P. vinkei infected mice. One hundred mice were infected, randomly selected and allocated to two groups of 40 animals each on day 13 after infection. One group was placebo treated, the other group received 3 IU AT III daily on days 13 to 19. Comparison of the survival time in the log rank test showed a prolongation of the median survival time (5 versus 9 days, P less than 0.01). It is concluded that AT III might be beneficial in the treatment of severe malaria cases.
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Affiliation(s)
- R Clemens
- Behringwerke AG, Abteilung Pharmakologie/Toxikologie, Marburg, Federal Republic of Germany
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19
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Raether W, Enders B, Hofmann J, Schwannecke U, Seidenath H, Hänel H, Uphoff M. Antimalarial activity of new floxacrine-related acridinedione derivatives: studies on blood schizontocidal action of potential candidates against P. berghei in mice and P. falciparum in vivo and in vitro. Parasitol Res 1989; 75:619-26. [PMID: 2671988 DOI: 10.1007/bf00930959] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [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: 01/02/2023]
Abstract
Deoxyfloxacrine derivatives (1-hydrazone: S 83 0083; 1-imine: S 84 7277) and floxacrine derivatives (10-methoxy-floxacrine: L 84 7667; 1-imine: L 84 7693) selected from a series of newly synthesized 3-aryl-7-chloro-3,4-dihydro-1,9(2H,10H)-acridinediones were evaluated for blood schizontocidal activities in mice infected with asexual stages of various drug-resistant lines of P. berghei and in New World monkeys infected with blood schizonts of different chloroquine-resistant strains of P. falciparum. All compounds tested showed high activity against drug-resistant lines of P. berghei (ED50: 1.0-4.4 mg/kg x 5, per os) and were distinctly superior in their antimalarial potency to floxacrine. Compounds L 84 7667 and L 84 7693 proved to be highly active against the FCBR strain of P. falciparum in vitro (IC50: 0.73-1.78 nmol); they effected temporary clearance of parasitemias due to the Palo Alto strain of P. falciparum in squirrel monkeys at oral doses of 15 mg/kg given daily for 5 consecutive days. Compounds S 83 0083 and S 84 7277, showing moderate in vitro effects (12.9-24.8 nmol), cleared parasitemias of the FCBR strain of P. falciparum in owl monkeys at oral doses of 20 mg/kg (S 84 7277) given daily for 5 or 7 consecutive days (follow-up period, 17 and 30 days, respectively) or at doses of 20 mg/kg (x 4) (S 83 0083) followed by doses of 40 mg/kg (x 3) within a follow-up period of 30 days. These observations suggest that the range of doses required for the cure of established P. falciparum infections is probably too large to cover infections with strains of the least susceptibility and might evoke toxic reactions by the potential candidates tested.
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Affiliation(s)
- W Raether
- Hoechst AG. Frankfurt/M. Federal Republic of Germany
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Knapp B, Shaw A, Hundt E, Enders B, Küpper HA. A histidin alanine rich recombinant antigen protects Aotus monkeys from P. falciparum infection. Behring Inst Mitt 1988:349-59. [PMID: 3044343] [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: 01/03/2023]
Abstract
We have isolated a cDNA clone coding for 165 amino acids of a histidine alanine rich protein. An extended repeat region of this clone codes for the tripeptide Ala-His-His, which is extremely conserved, and for the tripeptide Ala-Ala-Asp, which shows only slight variability among the repeat units. This antigen exhibits high homology to the HRPII antigen described by Wellems and Howard (1986). The coding region was expressed in E. coli as a MS2-polymerase fusion protein, which was purified and used for immunization of Aotus monkeys. The animals immunized with this fusion protein showed only low parasitemias (less than 2%) after infection with P. falciparum, while animals from the control group or animals immunized with a MS2-fusion protein carrying other malaria specific sequences were not protected. The result suggests that this antigen is a good candidate for a malaria vaccine.
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Affiliation(s)
- B Knapp
- Research Laboratories of Behringwerke AG, Marburg 1, W.-Germany
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Hermentin P, Neunziger G, Enders B, Seiler FR, Wiegandt H. Ganglioside GM1a as inhibitor of Plasmodium falciparum growth in vitro. Blut 1987; 55:127-9. [PMID: 3300819 DOI: 10.1007/bf00631784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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22
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Krauth-Siegel RL, Enders B, Henderson GB, Fairlamb AH, Schirmer RH. Trypanothione reductase from Trypanosoma cruzi. Purification and characterization of the crystalline enzyme. Eur J Biochem 1987; 164:123-8. [PMID: 3549299 DOI: 10.1111/j.1432-1033.1987.tb11002.x] [Citation(s) in RCA: 125] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The structural differences between trypanothione reductase of Trypanosoma cruzi and human glutathione reductase, an enzyme of known three-dimensional structure, offer an opportunity for rational drug design against Chagas' disease. As a first step in the analysis of the parasite enzyme we report its purification and characterization. 2.2 mg trypanothione reductase was extracted from 33 g wet weight of cultured epimastigotes or from 4 g lyophilized cells. The flavoenzyme was purified 2400-fold to homogeneity in three steps with an overall yield of 45%. The enzyme is a dimer with a subunit Mr of 50,000. Using NADPH (Km = 5 microM) and trypanothione disulfide (Km = 45 microM) as substrates, a turnover number of 14,200 min-1 was estimated. Trypanothione reductase, the parasite enzyme, and glutathione reductase, the host enzyme, exhibit mutually exclusive specificities for their respective disulfide substrates. When screening cell cultures or column eluates for the presence of trypanothione reductase, a microassay based on Ellman's reagent as indicator was used. A mixture of regioisomeric glutathionylspermidine disulfides isolated from Escherichia coli served as substrate in this microassay. Experimentally, the catalytic cycle of the enzyme can be subdivided into the half-reactions Eox + NADPH + H+----EH2 + NADP+, and EH2 + trypanothione disulfide----Eox + dihydrotrypanothione. This is also true for the crystallized enzyme in the presence of 2 M (NH4)2SO4. The spectral properties of trypanothione reductase both in the oxidized form (Eox) and in the two-electron-reduced form (EH2) closely resemble those of human glutathione reductase. Both proteins contain a flavin and a redox-active disulfide at the catalytic site. After reduction of Eox to EH2, trypanothione reductase can be inactivated by specifically alkylating one of the nascent active-site thiols.
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Hermentin P, Neunziger G, Enders B, Dahr W. Toxic effect of isolated glycophorin A on the in vitro growth of Plasmodium falciparum. Blut 1987; 54:115-22. [PMID: 3545325 DOI: 10.1007/bf00321041] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We have examined the inhibitory potencies of glycophorin A, a mixture of glycophorins B and C, chymotryptic fragments of GpA, desialylated GpA, alkaliborohydride treated GpA, and the O-linked tetrasaccharide isolated from GpA on the invasion of human red blood cells by synchronous Plasmodium falciparum (strain FCB). 50% inhibition of invasion, as measured by 3H-hypoxanthine incorporation into parasites, was achieved at 14 and 155 microM for GpA and GpA-CH1, respectively. We have noticed, however, that isolated GpA exhibits a toxic effect on the intraerythrocytic growth of the parasite whereas the chymotryptic fragment (amino acid residues 1-64 of GpA) does not. Thus the inhibitory potency of isolated GpA during erythrocyte invasion by the merozoite should be regarded as the result of both an inhibitory and a toxic effect. The inhibitory effect should be attributed to the carbohydrate-rich outer portion of GpA carrying clusters of neuraminic acid. The toxic effect should be attributed to the hydrophobic region of GpA which might be capable of inserting into the membrane of free merozoites and/or erythrocytes. Our data suggest that results previously obtained with glycoprotein inhibitors carrying hydrophobic portions may have to be questioned.
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24
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Diehl H, Zahner H, Schweinsberg H, Enders B. Intermediate host (Biomphalaria alexandrina) antigens partly protect against subcutaneous infections with cercariae of Schistosoma mansoni but are ineffective in infections by percutaneous invasion. Parasitol Res 1987; 73:538-40. [PMID: 3122204 DOI: 10.1007/bf00535330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 01/04/2023]
Abstract
Mice were immunized against hepatopancreas homogenate of Biomphalaria alexandrina, using Al(OH)3 as adjuvant, and challenged by subcutaneous (s.c.) injection of Schistosoma mansoni cercariae, percutaneous invasion of cercariae and intravenous (i.v.) injection of mechanically prepared schistosomula of different ages. Significantly reduced (about 50%) numbers of adult S. mansoni were found 42 days after challenge in immunized animals infected by s.c. injection of cercariae. Protective effects were detectable as early as 4 days after infection when the numbers of schistosomules in the lungs were reduced in immunized animals. However, immunized animals lacked protective immunity against S. mansoni when infected via the percutaneous route with cercariae or by i.v. injection of schistosomules of different ages. Experiments show that immunization of hosts against intermediate host antigens does not protect against S. mansoni infection via the natural route.
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Affiliation(s)
- H Diehl
- Institut für Parasitology, Justus-Liebig-Universität Giessen, Federal Republic of Germany
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25
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Hermentin P, Neunziger G, Paulsen H, Kolar C, Seiler FR, Dahr W, Enders B. Toxicity of "hydrophobic groupings" and the role of carbohydrates in Plasmodium falciparum infection. Behring Inst Mitt 1986:64-73. [PMID: 3530236] [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: 01/06/2023]
Abstract
We have tested various carbohydrate structures and neoglycoproteins (carbohydrate haptens attached to BSA) as inhibitors of the invasion of human red blood cells by Plasmodium falciparum merozoites (strain FCB) in synchronous in vitro cultures, using 3H-hypoxanthine incorporation into intraerythrocytic parasites as analytical tool, and have got the following results: The inhibition rate of N-acetyl-D-glucosamine glycosides is increased with increasing lipophilicity of the aglycon or spacer: CH3 less than (CH2)2NHCO(CH2)2COOCH3 less than (CH2)8COOCH3; p-Nitrophenyl glycosides proved to exhibit a toxic effect; The inhibition rate of synthetic disaccharide glycosides increased in the order beta DGal(1----4) beta DGlcNAcOCH3 less than beta DGlcNAc(1----4) beta DGlcNAcOCH3 less than beta DGlcNAc(1----4) alpha DManOCH3 less than beta DGlcNAc(1----4) beta DManO(CH2)8COOCH3; The O-linked tetrasaccharide alpha NeuAc(2----3) beta DGal(1----3) [alpha NeuAc(2----6)] alpha DGalNAcol, isolated from glycophorin A, was the best carbohydrate inhibitor tested so far; The inhibition rate of carbohydrates attached to BSA by an aliphatic spacer [-(CH2)8COOCH3] was not enhanced compared to the haptens; [DNP]33-BSA proved to be an extraordinary inhibitor of invasion which, however, most likely has to be attributed to a toxic effect; Observed toxicities appear to be attributable to hydrophobic interactions between the inhibitors and the RBC and merozoite membranes, which hampers both, intraerythrocytic growth of the parasite and its capability of RBC invasion.
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26
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Feh�r F, Baier H, Enders B, Krancher M, Laakmann J, Ocklenburg FJ, Skrodski D. Beitr�ge zur Chemie des Siliciums und des Germaniums. XXXVII. Weitere Untersuchungen zur Darstellung eines Silangemisches. Z Anorg Allg Chem 1985. [DOI: 10.1002/zaac.19855301123] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Abstract
Monosaccharides, disaccharides, and trisaccharides were tested as inhibitors of the in vitro growth of Plasmodium falciparum (strain FCB). While certain monosaccharides (N-acetyl-D-glucosamine, D-mannose, and 3-O-methyl-D-glucose) proved to exhibit a toxic or reversibly retarding effect on the intraerythrocytic development of the parasite, the corresponding alpha- or beta-methylglycosides did not. Several methylglycosides, synthetic di- and tri-saccharides, and artificial blood group antigens were further tested for inhibitory effects on invasion of host red blood cells in vitro. The synthetic disaccharides beta DGlcNAc(1----4) alpha DManOMe and beta DGlcNAc(1----4) DGlcNAc (chitobiose) were good inhibitors of invasion at 10 mM concentration, whereas beta DGal(1----4)beta DGlcNAcOMe was negligibly inhibitory. The inhibition rate of N-acetyl-D-glucosamine, beta-glycosidically linked to bovine serum albumin (BSA) by an alipathic spacer, -(CH2)8CO-, was not enhanced, compared to the corresponding hapten, beta DGlcNAcO(CH2)8COOCH3. The inhibition rates of blood group A- and B-trisaccharide haptens, which were inhibitors of invasion, were also not significantly enhanced when coupled to BSA by way of the corresponding amide spacer, -(CH2)2NHCO(CH2)7CO-. A remarkable enhancement of the inhibition rate was, however, observed when beta DGal(1----3) alpha DGalNAcO(CH2)2NHCO(CH2)7COOCH3 (T-hapten) was coupled to BSA. A clear-cut decrease in the inhibition rates of different beta-glycosides of N-acetyl-D-glucosamine, beta DGlcNAcOR, was observed, depending on the nature of the aglycon R(p-nitrophenyl greater than -(CH2)8COOCH3 greater than -(CH2)2NHCO(CH2)2COOCH3 greater than -CH3). Also, p-nitrophenyl-alpha-D-glucopyranoside was a much better inhibitor of invasion than the corresponding methyl glycoside, alpha DGlcOMe, which was not inhibitory. The properties of the aglycon spacer, used for the covalent attachment of the carbohydrate to the carrier protein, may thus be crucial for the outcome of the inhibition rate.
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Hermentin P, Enders B. Erythrocyte invasion by malaria (Plasmodium falciparum) merozoites: recent advances in the evaluation of receptor sites. Behring Inst Mitt 1984:121-41. [PMID: 6395849] [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: 01/20/2023]
Abstract
Recent advances in the understanding of the cellular, biochemical and molecular aspects of the highly specific interactions between P. falciparum merozoites and human red blood cells are summarized. Special attention is given to glycophorins A, B and C as receptors of invasion and to the role of carbohydrates and internal domains of glycophorin A, such as the Wrb antigen, as receptor site. Video pictures displaying the liberation of merozoites from schizont-infected red blood cells and the invasion of human erythrocytes by P. falciparum merozoites are also provided.
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Hermentin P, Enders B, Neunziger G, Dahr W, Wilkinson S, Miller LH, Pasvol G. Wr(a+b-)red blood cells are fully susceptible to invasion by Plasmodium falciparum. Lancet 1984; 2:466. [PMID: 6147533 DOI: 10.1016/s0140-6736(84)92942-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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30
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Herrmann F, Sieber G, Chen Z, Enders B, Komischke B, Rühl H. Further evidence for T cell abnormalities in chronic lymphocytic leukaemia of the B cell type. Clin Exp Immunol 1983; 53:109-14. [PMID: 6347474 PMCID: PMC1535548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Functional properties were studied in the purified T cell fraction of patients with chronic lymphocytic leukaemia of the B cell type (B-CLL). This analysis included the evaluation of T suppressor activity when investigated patients' T cells were co-cultured together with allogenic normal B and OKT4 enriched T cells in the presence of pokeweed mitogen (PWM). The Ig secreting cells (ISC) were assessed in a reverse haemolytic plaque assay (RHPA). Antibody-dependent cytotoxicity (ADCC) and natural killer activity (NK) were determined in a 51Cr release assay. Furthermore, purified T cells reactive with the monoclonal antibody HNK1, known to recognize most effector cells in ADCC and NK, were enumerated using an indirect immunofluorescence. Our results revealed increased T suppressor cell activity and markedly deficient NK activity in peripheral blood lymphocytes (PBL), T cell and T gamma cell fractions from B-CLL patients, whereas ADCC potential was only increased in T cells and T gamma cells. Accordingly, T cells were recognized by HNK1 in greater numbers in B-CLL patients than in healthy subjects. Our data suggest that there may be a link between our findings and the hypogammaglobulinaemia as well as the increased incidence of second neoplasias reported in CLL.
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Abstract
Macrophage- and T-cell-depleted mononuclear cells from 36 patients with B cell lymphoma and 12 healthy individuals were investigated by indirect immunofluorescence with the monoclonal antibodies NEI-011 (7.2) and NEI-015 (10.2). The monoclonal antibody NEI-011 (7.2) recognized the Ia antigen and identified almost all B cells in the peripheral blood of healthy individuals. Furthermore, neoplastic B cells from all patients except those with plasma cell proliferation were found to react with this antibody. NEI-015 (10.2), a monoclonal antibody known to react with both T cells and B-CLL cells, did not react with normal circulating B cells. However, this antibody did identify neoplastic B cells except in cases of plasma cell proliferation and lymphoblastic lymphoma.
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Abstract
Using a reverse hemolytic protein A plaque assay, spontaneous and pokeweed mitogen (PWM)-induced immunoglobulin (Ig) secretion was determined in peripheral blood from 22 patients with B1-chronic lymphocytic leukemia (CLL), one patient with B2-CLL, and one patient with suppressor T-CLL. Diagnoses were established by cytological and histological criteria as well as several marker analyses. Lymphocytes from B1- and B2-CLL patients were unable to secrete Ig either spontaneously or after PWM stimulation. In T-CLL lymphocytes, spontaneous Ig secretion was suppressed very probably by the OKT-8-positive leukemic population, since, after cultivation with PWM, a normal Ig secretion could be demonstrated which was paralleled by a decrease in the OKT-8-positive cells. Cocultivation experiments with freshly isolated, unseparated lymphocytes from normal subjects and lymphocytes from patients were of no informational value, since isolated normal B-cells alone already showed a high rate of Ig secretion. However, coculture experiments with separated subpopulations after PWM stimulation revealed an intrinsic B-cell defect in lymphocytes from B1-CLL patients, whereas their T-lymphocytes were found to be normal helper cells.
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Sieber G, Enders B, Rühl H. PWM-induced generation of immunoglobulin-secreting cells in patients with multiple myeloma. Klin Wochenschr 1981; 59:1101-8. [PMID: 7047886 DOI: 10.1007/bf01746197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The pokeweed-mitogen-induced transformation of B-lymphocytes into immunoglobulin-secreting cells was studied in vitro in 25 patients with multiple myeloma using a reverse hemolytic plaque assay. Fifteen patients showed a good response in generating immunoglobulin-secreting cells, whereas 10 patients showed a decreased B cell reactivity which was not due to intermittent melphalan/steroid therapy administered to 15 patients. Experiments with lymphocyte subpopulations demonstrated that the inability of some multiple-myeloma patients to generate immunoglobulin-secreting cells was always based on a defect in the B-cell subset. Co-culture experiments with lymphocytes from normal individuals and patients revealed a cell-mediated suppression in one case, whereas humoral suppressive factors in the patients' serum could not be observed using the reverse hemolytic plaque assay. Patients were classified into three groups: (a) patients with a normal B-cell function, (b) patients with a reversible, tumor-dependent suppression of B-cell reactivity and (c) patients in whom the normal B-cell population was replaced by non-reactive cells.
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Rühl H, Enders B, Bur M, Sieber G. Impaired B-lymphocyte reactivity in patients with Hodgkin's disease and non-Hodgkin-lymphomas. Blut 1981; 42:271-81. [PMID: 7016220 DOI: 10.1007/bf00996844] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The generation of immunoglobulin-secreting cells upon stimulation with pokeweed mitogen was studied in patients with Hodgkin's Disease (HD) and non-Hodgkin lymphomas (NHL) using a reverse hemolytic plaque assay. The experiments revealed that the majority of the patients in both groups had greatly diminished responses of their peripheral B-lymphocytes. Whereas in NHL patients an intrinsic B-cell defect is the most likely explanation for the impaired B-cell reactivity, the situation in HD appears to be more complex. In some patients with an active stage of the disease, suppressor cells were found to cause the unresponsiveness: in other patients, an intrinsic B-cell defect as well as a defect of the T helper cells were responsible for the diminished responses. The results further suggest that the immune defect in patients with HD is reversible and can be corrected by therapy.
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Sieber G, Bochert G, Enders B, Rühl H. Characteristics of immunoglobulin secretion in man evaluated by a reverse hemolytic plaque assay. Blut 1980; 41:81-92. [PMID: 7002234 DOI: 10.1007/bf01039652] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The kinetics of Pokeweed mitogen-induced transformation of human B-lymphocytes into immunoglobulin-secreting cells were examined in a reverse hemolytic plaque assay using protein A-coated sheep red blood cells as indicator cells. Peak responses occurred consistently after 6-8 days of incubation. After determination of the optimal experimental conditions the RHPA was found to be a reliable tool to estimate ISC in vitro; the technique was also found to be applicable for experiments surveying the B-cell response of an individual over a period of months. The PWM-induced transformation of B cells was absolutely T-cell-dependent. Other substances known as typical T-cell mitogens were also tested for polyclonal B-cell activation and some of them showed significant responses. Further experiments have shown that co-cultivation of non-HLA identical cells did not increase the number of plaques in unstimulated cultures whereas the addition of PWM leads to the generation of ISC within the expected range. These findings open a wide field of application of the RHPA in experimental and clinical immunology.
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Enders B, Brauns F, Zwisler O. Biochemical and technical considerations regarding the mass production of certain parasitic protozoa. Bull World Health Organ 1977; 55:393-402. [PMID: 22407 PMCID: PMC2366750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
This article summarizes the most relevant biochemical knowledge about growth factors as specific essential components of culture media, and calls attention to their significance with respect to the mass cultivation of some parasitic protozoa-e.g., Trypanosoma and Leishmania spp. and amoebae. Details of recent developments and techniques of parasite fermentation are reviewed.
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Ring J, Enders B, Seiler F, Seifert J, Steininger J, Brendel W. Use of indirect microhemagglutination test with stable sensitized red cells in the detection of horse protein allergy. Int Arch Allergy Appl Immunol 1976; 50:103-10. [PMID: 810439 DOI: 10.1159/000231486] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Sheep red blood cells were stabilized with sulfosalicylic acid and sensitized with purified horse-IgG by the action of glutardialdehyde. The cells were used in an indirect microhemmagglutination test with serum samples from 12 rabbits immunized with horse-IgG and complete Freund's adjuvant as well as from 10 control animals. 32 human serum samples were examined, 6 of them from patients with established horse protein allergy. The results were compared to those of a standard method of indirect hemagglutination using fresh human erythrocytes (group O Rh-), an active hemagglutination test against horse erythrocytes, Ouchterlony's immunodiffusion and skin tests with horse-IgG. The method proved to be very sensitive. The results correlated well with those of the other immunological techniques. The stable sensitized cells did not lose sensitivity after 1 year of storage at 4 degrees C.
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Enders B, Hungerer KD, Zwisler O. Survey on experiences with latex-Chagas-test in various countries. Tropenmed Parasitol 1975; 26:252-60. [PMID: 808885] [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: 12/24/2022]
Abstract
The principle of the latex agglutination technique was applied on the serodiagnosis of Chagas' disease. The latex particles coated with antigen from Trypanosoma cruzi are agglutinated by antibodies against T. cruzi in the serum of patients suffering thereof. In 11600 comparative determinations worked out mainly in a number of South American laboratories, the sensitivity of this test was compared with xenodiagnosis, CF, IFT and IHA. The latex Chagas test shows a mean coincidence of 90% with xenodiagnosis, 88% with CF, 75% with IFT, and 83% with IHA. The results indicate that the test is a useful new tool for the serodiagnosis of Chagas' disease. Also the data from CF, IFT and IHA were compared with each other. The latex Chagas test is sensitive even in the early stage of the disease. Also the specificity of the test was evaluated in other parasitic, bacterial and general diseases.
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Enders B, Lammers LC, Youssef G, Zaher AS, Zwisler O. [Arvicanthus niloticus (Nile rat)--a suitable host for experimental Schistosomiasis mansoni (author's transl)]. Tropenmed Parasitol 1974; 25:395-400. [PMID: 4446065] [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: 01/10/2023]
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40
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Enders B, Economy D, Hungerer KD, Zwisler O. Evaluation of a purified Schistosoma-skin test-antigen for the diagnosis of human bilharzia infection. Report of field trials in Ethiopia, Rhodesia, Sierra Leone and Brasil. Rev Inst Med Trop Sao Paulo 1974; 16:305-16. [PMID: 4456534] [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: 01/10/2023] Open
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Hungerer KD, Enders B. Lebendvaccinierung von M�usen gegen eine Trypanosoma cruzi-Infektion. Parasitol Res 1972. [DOI: 10.1007/bf00329243] [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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42
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Zahner H, Schütze HR, Lämmler G, Enders B. [The albumin-globulin ratio in the serum of Mastomys natalensis (Smith, 1834) in the coruse of infection with Litomosoides carinii]. Z Parasitenkd 1970; 33:267-81. [PMID: 5436819 DOI: 10.1007/bf00331466] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Zahner H, Herzog H, Saupe E, Enders B. [Precipitating antibodies in the serum of Mastomys natalensis in the course of Litomosoides carinii infection]. Z Parasitenkd 1970; 34:128-40. [PMID: 4993040 DOI: 10.1007/bf00260384] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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44
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