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Koch KM, Meier TB, Karr R, Nencka AS, Muftuler LT, McCrea M. Quantitative Susceptibility Mapping after Sports-Related Concussion. AJNR Am J Neuroradiol 2018; 39:1215-1221. [PMID: 29880474 DOI: 10.3174/ajnr.a5692] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 04/08/2018] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Quantitative susceptibility mapping using MR imaging can assess changes in brain tissue structure and composition. This report presents preliminary results demonstrating changes in tissue magnetic susceptibility after sports-related concussion. MATERIALS AND METHODS Longitudinal quantitative susceptibility mapping metrics were produced from imaging data acquired from cohorts of concussed and control football athletes. One hundred thirty-six quantitative susceptibility mapping datasets were analyzed across 3 separate visits (24 hours after injury, 8 days postinjury, and 6 months postinjury). Longitudinal quantitative susceptibility mapping group analyses were performed on stability-thresholded brain tissue compartments and selected subregions. Clinical concussion metrics were also measured longitudinally in both cohorts and compared with the measured quantitative susceptibility mapping. RESULTS Statistically significant increases in white matter susceptibility were identified in the concussed athlete group during the acute (24 hour) and subacute (day 8) period. These effects were most prominent at the 8-day visit but recovered and showed no significant difference from controls at the 6-month visit. The subcortical gray matter showed no statistically significant group differences. Observed susceptibility changes after concussion appeared to outlast self-reported clinical recovery metrics at a group level. At an individual subject level, susceptibility increases within the white matter showed statistically significant correlations with return-to-play durations. CONCLUSIONS The results of this preliminary investigation suggest that sports-related concussion can induce physiologic changes to brain tissue that can be detected using MR imaging-based magnetic susceptibility estimates. In group analyses, the observed tissue changes appear to persist beyond those detected on clinical outcome assessments and were associated with return-to-play duration after sports-related concussion.
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Affiliation(s)
- K M Koch
- From the Departments of Radiology (K.M.K., R.K., A.S.N.)
| | - T B Meier
- Neurosurgery (T.B.M., L.T.M., M.M.), Medical College of Wisconsin, Milwaukee, Wisconsin
| | - R Karr
- From the Departments of Radiology (K.M.K., R.K., A.S.N.)
| | - A S Nencka
- From the Departments of Radiology (K.M.K., R.K., A.S.N.)
| | - L T Muftuler
- Neurosurgery (T.B.M., L.T.M., M.M.), Medical College of Wisconsin, Milwaukee, Wisconsin
| | - M McCrea
- Neurosurgery (T.B.M., L.T.M., M.M.), Medical College of Wisconsin, Milwaukee, Wisconsin
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Gwinner W, Menne J, Lonnemann G, Bahlmann F, Koch KM, Haller H. Life-Threatening Complications of Extracorporeal Treatment in Patients with Severe Eosinophilia. Int J Artif Organs 2018; 28:1224-7. [PMID: 16404698 DOI: 10.1177/039139880502801205] [Citation(s) in RCA: 5] [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: 11/17/2022]
Abstract
We report three patients with massive eosinophilia of different etiology who developed bronchoconstriction, hypotension, and shock shortly after dialysis or leukapheresis had been begun. In two cases, ethylene oxide-free materials had been used ruling out an allergic reaction related to this compound. Degranulation of eosinophils with release of eosinophil peroxidase may have caused the observed adverse reactions, as suggested by in vitro experiments with blood from the three patients. Our observations draw attention to the fact that extracorporeal therapies may initiate life-threatening complications in patients with severe eosinophilia.
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Affiliation(s)
- W Gwinner
- Division of Nephrology, Department of Internal Medicine, Medical School Hannover, Hannover, Germany.
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Affiliation(s)
- S Shaldon
- Department of Nephrology, University Hospital, Nîmes, France
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Dinarello CA, Lonnemann G, Bingel M, Koch KM, Shaldon S. Biological consequences of monocyte activation during hemodialysis. Contrib Nephrol 2015; 59:1-9. [PMID: 3127115 DOI: 10.1159/000414608] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- C A Dinarello
- Department of Medicine, Tufts University School of Medicine, Boston, Mass
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Frei U, Nonnast-Daniel B, Schäffer J, Koch KM. Adverse cardiovascular effects of partial correction of renal anemia by recombinant human erythropoietin. Contrib Nephrol 2015; 82:72-8. [PMID: 2093530 DOI: 10.1159/000418720] [Citation(s) in RCA: 2] [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] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The analysis of the hemodynamic parameters involved in the regulation of blood pressure during correction of anemia shows - although peripheral resistance and cardiac output behave qualitatively as in the nonuremic patient - that the extent of change may be inadequate resulting in an increased blood pressure. The underlying mechanisms are not yet fully understood but to a greater part may be related to preexisting pathology due to a history of long-lasting hypertension. To avoid cardiovascular complications under rhEPO therapy the following should be considered: patients with a history of hypertension, even if they are normotensive in the anemic state, are at a higher risk for developing hypertension under rhEPO. Hypertensive complications may be rare events when anemia is corrected slowly. Further studies will demonstrate whether in addition to the benefit of a very low maintenance dose of rhEPO subcutaneous administration will also contribute to the reduction of the incidence of hypertension.
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Affiliation(s)
- U Frei
- Abteilung für Nephrologie, Medizinische Hochschule Hannover, FRG
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Affiliation(s)
- J Schäffer
- Nephrology Division, Medical School, Hannover, Germany
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Affiliation(s)
- S Shaldon
- Department of Nephrology, University Hospital, Nîmes, France
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Pollok M, Bommer J, Gurland HJ, Koch KM, Schoeppe W, Scigalla P, Baldamus CA. Effects of recombinant human erythropoietin treatment in end-stage renal failure patients. Results of a multicenter phase II/III study. Contrib Nephrol 2015; 76:201-11; discussion 212-8. [PMID: 2684523 DOI: 10.1159/000417896] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- M Pollok
- Department of Nephrology, University Hospital, Cologne, FRG
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Bommer J, Samtleben W, Koch KM, Baldamus CA, Grützmacher P, Scigalla P. Variations of recombinant human erythropoietin application in hemodialysis patients. Contrib Nephrol 2015; 76:149-56; discussion 156-8. [PMID: 2684517 DOI: 10.1159/000417891] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- J Bommer
- Nephrology Division, I. Medizinische Universitätsklinik, Heidelberg, FRG
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Schindler R, Lonnemann G, Shaldon S, Koch KM, Dinarello CA. Induction of interleukin-1 and tumor necrosis factor during in vitro hemodialysis with different membranes. Contrib Nephrol 2015; 74:58-65. [PMID: 2702147 DOI: 10.1159/000417471] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- R Schindler
- Tufts University School of Medicine, Boston, Mass
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Bahlmann J, Schöter KH, Scigalla P, Gurland HJ, Hilfenhaus M, Koch KM, Muthny FA, Neumayer HH, Pommer W, Quelhorst E. Morbidity and mortality in hemodialysis patients with and without erythropoietin treatment: a controlled study. Contrib Nephrol 2015; 88:90-106. [PMID: 2040200 DOI: 10.1159/000419519] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- J Bahlmann
- Abteilung Nephrologie, Medizinische Hochschule, Hannover, FRG
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Brunkhorst R, Nonnast-Daniel B, Koch KM, Frei U. Hypertension as a possible complication of recombinant human erythropoietin therapy. Contrib Nephrol 2015; 88:118-25; discussion 126. [PMID: 2040173 DOI: 10.1159/000419521] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The analysis of the hemodynamics accompanying correction of renal anemia by rhEPO shows that--although they behave qualitatively as in nonuremic anemic patients--cardiac output and peripheral resistance may change inadequately and thereby cause a rise of blood pressure. The underlying mechanisms are not yet fully understood but to a great part may be related to preexisting pathology due to a history of longlasting hypertension. In some patients the development of hypertension may only represent a temporary phenomenon of hemodynamic dysregulation. To avoid cardiovascular complications the following should be considered: Patients with a history of hypertension, even if they are normotensive in the anemic state, are at a higher risk of developing hypertension during therapy with rhEPO. Hypertensive complications may be rare events when anemia is corrected slowly. In case of the development or aggravation of hypertension a reduction of the target hematocrit is indicated.
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Affiliation(s)
- R Brunkhorst
- Abteilung Nephrologie, Medizinische Hochschule Hannover, FRG
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Granolleras C, Branger B, Shaldon S, Nonnast-Daniel B, Koch KM, Pollok M, Baldamus CA. Subcutaneous erythropoietin: a comparison of daily and thrice weekly administration. Contrib Nephrol 2015; 88:144-8; discussion 149-51. [PMID: 2040176 DOI: 10.1159/000419524] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- C Granolleras
- Department of Nephrology, University Hospital, Nîmes, France
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Baldamus CA, Mantz P, Kachel HG, Koch KM, Schoeppe W. Baroreflex in patients undergoing hemodialysis and hemofiltration. Contrib Nephrol 2015; 41:409-14. [PMID: 6525864 DOI: 10.1159/000429319] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Floege J, Wilks MF, Granolleras C, Shaldon S, Koch KM. Beta-2-microglobulin and dialysis-related amyloidosis. Recent developments. Contrib Nephrol 2015; 74:120-6. [PMID: 2702128 DOI: 10.1159/000417480] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- J Floege
- Department of Nephrology, Medizinische Hochschule Hannover, FRG
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Hilfenhaus M, Koch KM, Bechstein PB, Schmidt H, Fassbinder W, Baldamus CA. Therapy and monitoring of hypersiderosis in chronic renal insufficiency. Contrib Nephrol 2015; 38:167-74. [PMID: 6713893 DOI: 10.1159/000408082] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In RDT hemosiderosis appears to be an inevitable complication only in the small number of patients in need of frequent transfusions. To prevent clinical consequences (e.g. cardiomyopathy) known from polytransfused patients without renal disease, transplantation should be considered in RDT patients in need of frequent transfusions. Iron substitution - preferably oral - to replace dialysis-related iron loss does not cause clinically significant hemosiderosis provided iron stores are monitored adequately. A sufficient method of controlling iron stores in RDT patients under iron substitution or regular transfusion therapy is a twice annual determination of serum ferritin concentration. The treatment of choice for hemosiderosis in nontransfused RDT patients is discontinuation of iron substitution. When polytransfused RDT patients with severe hemosiderosis cannot be transplanted and submitted consecutively to phlebotomy, DFO treatment is indicated. Quantitative data regarding optimal dosage and application of DFO in RDT patients are not yet available. Constant infusion of DFO during hemodialysis may be superior to bolus application.
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Nonnast-Daniel B, Creutzig A, Kühn K, Bahlmann J, Reimers E, Brunkhorst R, Caspary L, Koch KM. Effect of treatment with recombinant human erythropoietin on peripheral hemodynamics and oxygenation. Contrib Nephrol 2015; 66:185-94. [PMID: 3292147 DOI: 10.1159/000416017] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Slow progressive improvement of renal anemia from 21 up to 33% hematocrit by rhEPO treatment results in an increase of tissue oxygenation as indicated by a rise of the transcutaneous oxygen pressure. In normotensive patients this was accompanied by an increase in MAP (delta 6 mm Hg) within the normal range and a significant fall of the regional blood flow. These hemodynamic changes are caused by increases of the regional and presumably also of the total peripheral vascular resistance. Most likely the increase in total peripheral vascular resistance represents an autoregulatory event triggered by the rising tissue oxygenation. From the present data it is difficult to estimate to what extent the observed rise in hematocrit affects peripheral vascular resistance also via an increase of blood viscosity.
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Affiliation(s)
- B Nonnast-Daniel
- Department Innere Medizin und Dermatologie, Medizinische Hochschule Hannover, FRG
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Affiliation(s)
- J Flöge
- Department of Nephrology, Medizinische Hochschule Hannover, FRG
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Gwinner W, Frei U, Matthies C, Koch KM, Stolte H. Glomerular barrier function for serum proteins in experimental heart failure. Contrib Nephrol 2015; 83:144-50. [PMID: 2100705 DOI: 10.1159/000418790] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- W Gwinner
- Division of Nephrology, Medical School, Hannover, FRG
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Affiliation(s)
- S Shaldon
- Department of Nephrology, University Hospital, Nîmes, France
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Lonnemann G, Floege J, Shaldon S, Koch KM. Blood-dialyzer interactions: their role in long-term complications of hemodialysis. Contrib Nephrol 2015; 100:155-71. [PMID: 1458901 DOI: 10.1159/000421458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- G Lonnemann
- Department of Nephrology, Medizinische Hochschule, Hannover, FRG
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Kachel HG, Altmeyer P, Baldamus CA, Koch KM. Deposition of an amyloid-like substance as a possible complication of regular dialysis treatment. Contrib Nephrol 2015; 36:127-32. [PMID: 6839769 DOI: 10.1159/000407589] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Koch KM, Baldamus CA, Frei U, Ernst W. Hemofiltration, future aspects in relation to other treatment modalities of uremia. Contrib Nephrol 2015; 32:165-9. [PMID: 7128153 DOI: 10.1159/000406919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Ritz E, Bosch J, Henderson LW, Kishimoto T, Koch KM, Pierides A, Shaldon S, Streicher E. Hemofiltration and vascular stability. Contrib Nephrol 2015; 32:200-17. [PMID: 6751687 DOI: 10.1159/000406925] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Fassbinder W, Koch KM. A specific immunohaemolytic anaemia induced by formaldehyde sterilisation of dialysers. Contrib Nephrol 2015; 36:51-67. [PMID: 6839775 DOI: 10.1159/000407581] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Crown J, Kennedy MJ, Tresca P, Marty M, Espie M, Burris HA, DeSilvio M, Lau MR, Kothari D, Koch KM, Diéras V. Optimally tolerated dose of lapatinib in combination with docetaxel plus trastuzumab in first-line treatment of HER2-positive metastatic breast cancer. Ann Oncol 2014; 24:2005-11. [PMID: 23878115 DOI: 10.1093/annonc/mdt222] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND This phase IB, open-label, dose-escalation study evaluated the safety, tolerability, and optimally tolerated regimen (OTR) of lapatinib in combination with docetaxel and trastuzumab in patients with previously untreated stage IV metastatic breast cancer (MBC) tumors overexpressing human epidermal growth factor receptor 2 (HER2). PATIENTS AND METHODS Evaluated dose regimens included lapatinib (500-1500 mg/day), docetaxel (triweekly; 60-100 mg/m²), and trastuzumab (weekly; 2 mg/kg fixed dose); prophylactic granulocyte colony-stimulating factor was included with regimens with ≥750 mg/day lapatinib. End points included OTR and safety/tolerability (primary), overall response rate (ORR), and pharmacokinetics (secondary). RESULTS None of the patients (N = 53) experienced dose-limiting toxic effects (DLTs) at the highest dose level; thus, the OTR of lapatinib with 100 mg/m(2) docetaxel was not determined. Common adverse events included diarrhea, nausea, alopecia, fatigue, and rash; grade 3/4 (≥2 patients) were neutropenia, diarrhea, leukopenia, peripheral neuropathy, and rash. Seven patients had DLTs (cycle 1). In 45 patients with measurable disease confirmed by bone scan, investigator-assessed ORR was 31%; without bone scan, confirmation was 64%; 8 patients without measurable disease were evaluated as stable. Lapatinib/docetaxel plasma concentrations were positively associated with complete response. CONCLUSIONS Lapatinib/docetaxel/trastuzumab is a feasible and well-tolerated treatment of untreated HER2-positive stage IV MBC. Two lapatinib/docetaxel OTR doses were recommended (1250 mg/75 mg/m²; 1000 mg/100 mg/m²). CLINICAL TRIAL NUMBER NCT00251433.
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Affiliation(s)
- J Crown
- All Ireland Cooperative Oncology Research Group, Dublin, Ireland.
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Bonnefoi H, Zaman K, Debled M, Fiche M, Fournier M, Nobahar M, Pierga JY, Koch KM, Bartlett J, Zimmer A, Marreaud S, Bogaerts J, Cameron D. An European Organisation for Research and Treatment of Cancer phase I study of lapatinib and docetaxel as neoadjuvant treatment for human epidermal growth factor receptor 2 (HER2) positive locally-advanced/inflammatory or large operable breast cancer. Eur J Cancer 2012; 49:281-9. [PMID: 22999386 DOI: 10.1016/j.ejca.2012.08.006] [Citation(s) in RCA: 5] [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] [Received: 04/17/2012] [Revised: 08/03/2012] [Accepted: 08/06/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND Lapatinib is an effective anti-HER2 therapy in advanced breast cancer and docetaxel is one of the most active agents in breast cancer. Combining these agents in pre-treated patients with metastatic disease had previously proved challenging, so the primary objective of this study aimed to determine the maximum tolerated dose (MTD) in treatment-naive patients, by identifying acute dose-limiting toxicities (DLT) during cycle 1 in the first part of a phases 1-2 neoadjuvant European Organisation for Research and Treatment of Cancer (EORTC) trial. PATIENTS AND METHODS Patients with large operable or locally-advanced HER2 positive breast cancer were treated with continuous lapatinib, and docetaxel every 21days for 4 cycles. Dose levels (DLs) were: 1000/75, 1250/75, 1000/85, 1250/85, 1000/100 and 1250/100 (mg/day)/(mg/m(2)). RESULTS Twenty-one patients were included. Two DLTs occurred at dose level 5 (1000/100); one grade 4 neutropenia ≥ 7days and one febrile neutropenia. A further 3 patients were therefore treated at the same dose with prophylactic granulocyte-colony stimulating factor (G-CSF), and 3 patients at dose level 6. No further DLTs were observed. CONCLUSIONS Our recommended dose for phase II is lapatinib 1000mg/day and docetaxel 100mg/m(2) with G-CSF in HER2 positive non-metastatic breast cancer. The dose of lapatinib should have been 1250mg/day but we were mindful of the high rate of treatment discontinuation in GeparQuinto with lapatinib 1250mg/day combined with docetaxel. No grade 3-4 diarrhoea was observed. Pharmacodynamics analysis suggests that concomitant medications altering P-glycoprotein activity (in addition to lapatinib) can modify toxicity, including non-haematological toxicities. This needs verification in larger trials, where it may contribute to understanding the sources of variability in clinical toxicity and treatment discontinuation.
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Affiliation(s)
- H Bonnefoi
- Institut Bergonié, INSERM U916, Bordeaux, France.
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Koch KM, Brau AC, Chen W, Gold GE, Hargreaves BA, Koff M, McKinnon GC, Potter HG, King KF. Imaging near metal with a MAVRIC-SEMAC hybrid. Magn Reson Med 2011; 65:71-82. [PMID: 20981709 DOI: 10.1002/mrm.22523] [Citation(s) in RCA: 159] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The recently developed multi-acquisition with variable resonance image combination (MAVRIC) and slice-encoding metal artifact correction (SEMAC) techniques can significantly reduce image artifacts commonly encountered near embedded metal hardware. These artifact reductions are enabled by applying alternative spectral and spatial-encoding schemes to conventional spin-echo imaging techniques. Here, the MAVRIC and SEMAC concepts are connected and discussed. The development of a hybrid technique that utilizes strengths of both methods is then introduced. The presented technique is shown capable of producing minimal artifact, high-resolution images near total joint replacements in a clinical setting.
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Affiliation(s)
- K M Koch
- Applied Science Laboratory, GE Healthcare, Waukesha, Wisconsin 53188, USA.
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Abstract
The desire to apply magnetic resonance imaging (MRI) techniques in the vicinity of embedded metallic hardware is increasing. The soft-tissue contrast available with MR techniques is advantageous in diagnosing complications near an increasing variety of MR-safe metallic hardware. Near such hardware, the spatial encoding mechanisms utilized in conventional MRI methods are often severely compromised. Mitigating these encoding difficulties has been the focus of numerous research investigations over the past two decades. Such approaches include view-angle tilting, short echo-time projection reconstruction acquisitions, single-point imaging, prepolarized MRI, and postprocessing image correction. Various technical advances have also enabled the recent development of two alternative approaches that have shown promising clinical potential. Here, the physical principals and proposed solutions to the problem of MRI near embedded metal are discussed.
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Affiliation(s)
- K M Koch
- Applied Science Laboratory, GE Healthcare, Waukesha, Wisconsin 53188, USA.
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Midgley RS, Kerr DJ, Flaherty KT, Stevenson JP, Pratap SE, Koch KM, Smith DA, Versola M, Fleming RA, Ward C, O'Dwyer PJ, Middleton MR. A phase I and pharmacokinetic study of lapatinib in combination with infusional 5-fluorouracil, leucovorin and irinotecan. Ann Oncol 2007; 18:2025-9. [PMID: 17846021 DOI: 10.1093/annonc/mdm366] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [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: 11/13/2022] Open
Abstract
BACKGROUND This study determined the optimally tolerated regimen (OTR) of oral lapatinib administered in combination with infusional 5-fluorouracil (5-FU), leucovorin and irinotecan (FOLFIRI) and assessed the safety, tolerability and pharmacokinetics of the combination. PATIENTS AND METHODS Twenty-five patients were enrolled; 12 patients were treated at three dose levels to determine OTR; then 13 patients were treated at OTR to evaluate the pharmacokinetics of the combination. RESULTS The 2-weekly OTR comprised lapatinib 1250 mg/day with irinotecan 108 mg/m(2) (day 1) and leucovorin 200 mg/m(2), 5-FU bolus 240 mg/m(2) and 5-FU infusion 360 mg/m(2) (days 1 and 2); doses of 5-FU and irinotecan represent a 40% reduction in dose compared to conventional FOLFIRI. Dose-limiting toxicities were grade 3 diarrhoea and grade 4 neutropenia. Co-administration of lapatinib increased the area under the plasma concentration-time curve of SN-38, the active metabolite of irinotecan, by an average of 41%; no other pharmacokinetic interactions were observed. Of 19 patients evaluable for disease response assessment, four patients had partial response and nine patients had stable disease. CONCLUSION The combination of lapatinib and FOLFIRI is safe and demonstrates clinical activity; the documented PK interaction can effectively be compensated by lowering the doses of 5-FU and irinotecan. This regime may be further tested in a phase II trial.
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Affiliation(s)
- R S Midgley
- Department of Clinical Pharmacology, University of Oxford, Oxford, UK.
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Ismail IM, Andrew PD, Cholerton J, Roberts AD, Dear GJ, Taylor S, Koch KM, Saynor DA. Characterization of the metabolites of alosetron in experimental animals and human. Xenobiotica 2005; 35:131-54. [PMID: 16019944 DOI: 10.1080/00498250400028247] [Citation(s) in RCA: 5] [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: 01/27/2023]
Abstract
The metabolism of radiolabelled alosetron was studied in rat, dog, rabbit, mouse and human. The metabolism in rat and dog was studied at a low and an elevated dose designed to generate sufficient quantities of metabolite for definitive identification. A strategy for the characterization of metabolites in cases of extensive metabolism was developed and demonstrated for alosetron. Semi-preparative high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS), nuclear magnetic resonance (NMR) and liquid chromatography-nuclear magnetic resonance (HPLC-NMR) enabled the isolation and characterization of 28 metabolites of alosetron. The characterization of the metabolites in animal excreta facilitated the identification of human systemic metabolites.
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Affiliation(s)
- I M Ismail
- DMPK, GlaxoSmithKline Research and Development, Ware, UK.
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Koch KM, Corrigan BW, Manzo J, James CD, Scott RJ, Stead AG, Kersey KE. Alosetron repeat dose pharmacokinetics, effects on enzyme activities, and influence of demographic factors. Aliment Pharmacol Ther 2004; 20:223-30. [PMID: 15233703 DOI: 10.1111/j.1365-2036.2004.02031.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [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: 12/21/2022]
Abstract
AIM To assess the pharmacokinetics of alosetron, its effect on in vivo enzyme activities, and influence of demographic factors during repeated dosing. METHODS Thirty healthy men and women received 1 mg oral alosetron twice-daily for 29.5 days and a single oral dose of a metabolic probe cocktail before and on the last day of alosetron dosing. Serum alosetron concentrations were measured on days 1, 8, 15, 22 and 29. Probe-substrate and metabolite concentrations were measured after each cocktail dose. RESULTS Alosetron accumulation in serum was negligible. Exposure to alosetron did not alter probe-metabolite/substrate ratios associated with CYP2C19, 2E1, 2C9, or 3A4 activity, but modestly decreased those associated with CYP1A2 and N-acetyltransferase activity. Systemic exposure to alosetron was higher in women, positively correlated with age and body mass index, and negatively correlated with CYP1A2 activity. Incidence of constipation was higher in women, but not associated with alosetron concentration. CONCLUSIONS Single dose data can reliably predict the pharmacokinetics of alosetron after repeated doses. Alosetron exhibits limited potential for inhibition of cytochrome P450-mediated metabolism. Interindividual differences in alosetron pharmacokinetics associated with demographic factors may be related to strong dependence on metabolism by CYP1A2.
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Affiliation(s)
- K M Koch
- Department of Clinical Pharmacology and Discovery Medicine, GlaxoSmithKline, Research Triangle Park, NC, USA.
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Abstract
AIMS To determine the effects of sex and age on the pharmacokinetics of alosetron. METHODS Single oral and intravenous 2 mg doses of alosetron were administered on separate occasions to 48 healthy, young and elderly, males and females. Serum was sampled for 12 h post-dose to measure alosetron concentrations. RESULTS Serum concentrations of alosetron were higher in females than in males, resulting from a sex difference in clearance by metabolism. Mean clearance values were 504 vs 677 ml min(-1) in young females vs males (mean ratio 0.75), and 461 vs 670 ml min(-1) in elderly females vs males (mean ratio 0.69). The sex difference in alosetron pharmacokinetics achieved statistical significance in the elderly, but not in the young. Irrespective of sex, alosetron clearance was increased by smoking. Serum concentrations tended to be higher in the elderly, although the effect of age was generally not significant. Volume of distribution was smaller in females (approximately 63 l) compared with males (approximately 84 l), regardless of age or the sex difference in body weight. CONCLUSIONS A significant difference in clearance by metabolism of alosetron between the sexes, and possibly between the young and elderly was observed.
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Affiliation(s)
- K M Koch
- Clinical Pharmacology, GlaxoSmithKline, North Carolina, USA
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Abstract
AIMS To examine the potential for alosetron to alter the pharmacokinetics of theophylline by inhibiting its metabolism, as suggested by in vitro and in vivo effects on CYP1A2 activity. METHODS Ten healthy female volunteers received theophylline 200 mg twice daily alone for 8 days and with alosetron 1 mg twice daily for 15 days in this randomized, placebo-controlled, two-way-crossover study. RESULTS Alosetron had no significant effect on theophylline plasma concentrations (Cmax approximately 9 microg ml(-1), AUC approximately 90 microg ml(-1) h) or oral formation clearance of three major metabolites produced via CYP1A2: 3-methylxanthine, 1-methylurate and 1,3-dimethylurate (5, 7 and 16 ml min(-1), respectively). Concomitant administration of alosetron and theophylline was well tolerated. CONCLUSIONS The absence of a clinical drug interaction involving inhibition of theophylline metabolism by alosetron was not predicted by in vitro and in vivo metabolic probe data.
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Affiliation(s)
- K M Koch
- Glaxo Wellcome Inc., Research Triangle Park, North Carolina 27709, USA
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Floege J, Schäffer J, Koch KM. Scintigraphic methods to detect beta2-microglobulin associated amyloidosis (Abeta2-microglobulin amyloidosis). Nephrol Dial Transplant 2001; 16 Suppl 4:12-6. [PMID: 11402091 DOI: 10.1093/ndt/16.suppl_4.12] [Citation(s) in RCA: 10] [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: 11/14/2022] Open
Abstract
beta2-Microglobulin-derived amyloidosis (Abeta2m) represents a major cause or morbidity in patients with end-stage renal disease. Symptoms of Abeta2m amyloid are mainly related to (peri-) articular amyloid deposition. Conventional non-invasive diagnostic techniques, i.e. clinical evaluation, joint ultrasonography or X-ray, computed tomography or magnetic resonance imaging findings, as well as conventional bone scans, suffer from relative non-specificity and/or low sensitivity. Two recent methods, namely scintigraphy with radiolabelled serum amyloid P component (SAP) or with the radiolabelled Abeta2m-precursor protein, beta2-microglobulin (beta2m), yield more specific information. Using (123)I-labelled SAP, Abeta2m deposits have been visualized in several long-term haemodialysis (HD) patients. However, this scan did not show tracer accumulation in other frequently involved sites, such as hips or shoulders, but did frequently label the spleen, which is usually spared from Abeta2m deposits. Scanning with (131)I-labelled beta2m, in contrast, yielded tracer accumulations corresponding to the typical distribution pattern of Abeta2m. Specificity of this method was shown by several methods, and the sensitivity was found to markedly exceed that of combined clinical and radiological investigations. Recently, both the radiation exposure and the optical resolution of this latter scan have been further refined by substituting (131)I with (111)In. In a final step we generated recombinant human beta2m (rhbeta2m). (111)In-rhbeta2m again failed to show significant tracer accumulation over joint regions in patients on short-term HD without evidence of Abeta2m amyloidosis. In contrast, local tracer accumulations similar to those observed with natural, (111)In-labelled beta2m could be demonstrated in long-term HD patients with evidence of Abeta2m amyloidosis. In conclusion, scintigraphy for Abeta2m with (111)In-labelled rhbeta2m provides a homogenous and safe recombinant protein source, and allows for the sensitive and specific non-invasive detection of Abeta2m-amyloid deposits in dialysis patients.
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Affiliation(s)
- J Floege
- Division of Nephrology, Department of Medicine, University of Aachen, Germany
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Lonnemann G, Koch KM. Efficacy of ultra-pure dialysate in the therapy and prevention of haemodialysis-associated amyloidosis. Nephrol Dial Transplant 2001; 16 Suppl 4:17-22. [PMID: 11402092 DOI: 10.1093/ndt/16.suppl_4.17] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- G Lonnemann
- Department of Nephrology, Medizinische Hochschule Hannover, Hannover, Germany
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Kurts C, Klebba I, Davey GM, Koch KM, Miller JF, Heath WR, Floege J. Kidney protection against autoreactive CD8(+) T cells distinct from immunoprivilege and sequestration. Kidney Int 2001; 60:664-71. [PMID: 11473649 DOI: 10.1046/j.1523-1755.2001.060002664.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The kidney tubulointerstitium has been reported to be protected from T-cell--mediated damage by sequestration from the T-cell compartment. We examined the ability of autoreactive T cells to infiltrate the kidney in a transgenic mouse model. METHODS RIP-mOVA transgenic mice express the model autoantigen, membrane-bound ovalbumin (mOVA), in kidney proximal tubular cells and pancreatic beta cells. OVA-specific CD8(+) T cells (OT-I cells) were transferred into these recipient mice and their immune response against pancreas and kidney tissue was compared. RESULTS When OVA-specific CD8(+) T cells (OT-I cells) were injected into RIP-mOVA mice, they were activated in the renal and pancreatic lymph nodes by cross-presentation. These in vivo-activated OT-I cells caused the destruction of pancreatic islets leading to autoimmune diabetes, but did not infiltrate the kidney. Neither CD95--CD95 ligand interactions, which have been proposed to induce apoptosis in T cells infiltrating immunologically privileged sites, nor CD30 signaling was responsible for the lack of kidney infiltration. When OT-I cells were activated in vitro prior to injection, they could infiltrate the kidney and caused acute renal failure when injected in high numbers. CONCLUSIONS A mechanism distinct from previously described organ-specific protective mechanisms such as sequestration of antigen or CD95-mediated immunoprivilege contributes to the protection of the kidney tubulointerstitium from infiltration by autoreactive CD8(+) T cell.
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Affiliation(s)
- C Kurts
- Division of Nephrology and Immunology, University of Aachen, Aachen, Germany.
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O'Connor-Semmes RL, Kersey K, Williams DH, Lam R, Koch KM. Effect of ranitidine on the pharmacokinetics of triazolam and alpha-hydroxytriazolam in both young (19-60 years) and older (61-78 years) people. Clin Pharmacol Ther 2001; 70:126-31. [PMID: 11503006 DOI: 10.1067/mcp.2001.117120] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE This study evaluated the effect of oral ranitidine (75 mg and 150 mg) on the pharmacokinetics of triazolam (0.25 mg) and its major metabolite, alpha-hydroxytriazolam, in both young and older people. Metabolite data were used to distinguish the mechanism of this interaction. METHOD This was a randomized, open-label, 3-way crossover study. Eighteen young (19-60 years) and 12 older (61-78 years) men and women were randomly assigned to receive evening doses of triazolam 0.25 mg (1) alone, (2) on the third day of dosing ranitidine 75 mg twice daily for 4 days, and (3) on the third day of dosing ranitidine 150 mg twice daily for 4 days. RESULTS In the young group, mean triazolam area under the concentration-time curve from time zero to infinity [AUC(0-infinity)] was 10% and 28% higher after treatment with 75 mg and 150 mg ranitidine, respectively. In the older group, mean triazolam AUC(0-infinity) was 31% and 28% higher after treatment with 75 mg and 150 mg ranitidine, respectively. There was no change in the alpha-hydroxytriazolam/triazolam AUC(0-infinity) ratio in either age group, indicating that neither formation nor elimination of alpha-hydroxytriazolam was affected by ranitidine. There were no changes in the half-life of triazolam or alpha-hydroxytriazolam. CONCLUSION Ranitidine increases oral absorption of triazolam in both young and older people. This effect is likely caused by elevation of gastrointestinal pH, allowing for greater absorption of acid-labile triazolam. The difference in this effect between age groups at the lower 75-mg dose of ranitidine suggests that older people may be more sensitive to the antisecretory effect of ranitidine.
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Abstract
Lotronex (alosetron hydrochloride) is a 5-HT3 receptor antagonist indicated for the treatment of irritable bowel syndrome (IBS) in females whose predominant bowel habit is diarrhea. Alosetron is extensively metabolized by multiple cytochrome P450 (CYP) enzymes, including CYP2C9 and CYP3A4. Fluoxetine is an antidepressant that is administered as a racemic mixture of equipotent R- and S-enantiomers. Fluoxetine metabolism involves CYP2D6 and CYP2C9 in the formation of its major metabolite, norfluoxetine. This metabolite is also present as two enantiomers, of which only the S-enantiomer exhibits comparable antidepressant activity. This study was conducted to assess the potential for an effect of alosetron on the pharmacokinetics of fluoxetine. This was an open-label, two-period, nonrandomized, crossover study in 12 healthy female and male volunteers. The pharmacokinetics for both enantiomers of fluoxetine and norfluoxetine were examined following single oral doses of 20 mg fluoxetine, given alone and in combination with alosetron 1 mg twice daily for 15 days. The results showed small delays in peak concentration but no clinically significant effect of alosetron on the pharmacokinetics of S- and R-fluoxetine or S- and R-norfluoxetine. Coadministration of alosetron and fluoxetine was well tolerated by all subjects.
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Affiliation(s)
- D L D'Souza
- Department of Clinical Pharmacology, Glaxo Wellcome Canada, Mississauga, Ontario
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Abstract
Lotronex (alosetron hydrochloride) is a 5-HT3 receptor antagonist indicated for the treatment of irritable bowel syndrome (IBS) in females whose predominant bowel habit is diarrhea. Alosetron is extensively metabolized by multiple cytochrome P450 (CYP) enzymes, including CYP 2C9 and 3A4. Alprazolam is a short-acting benzodiazepine commonly prescribed for the treatment of anxiety disorders and a potential comedication in patients with IBS. Alprazolam is extensively metabolized by CYP3A4. This clinical study was conducted to assess the potential for a metabolic drug interaction between these two CYP3A4 substrates. This was an open-label, randomized, two-period, crossover study in 12 healthy female and male volunteers to determine the effect of concomitant administration of alosetron at the recommended dose of 1 mg p.o. bid on the pharmacokinetics of alprazolam following a single oral 1 mg dose. The results showed no effect of alosetron on the pharmacokinetics of alprazolam. Mean alprazolam AUC was 210 and 202 ng.h/mL in the absence and the presence of alosetron, respectively. Therefore, alprazolam may be safely coadministered with alosetron without the need for dosage adjustment.
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Affiliation(s)
- D L D'Souza
- Department of Clinical Pharmacology, Glaxo Wellcome Canada, Mississauga, Ontario
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Abstract
beta(2)-microglobulin amyloidosis (A beta(2)M) is a major determinant of morbidity in patients on dialysis treatment. Symptoms of A beta(2)M amyloid are mainly related to (peri-)articular amyloid deposition. Imaging techniques [i.e., joint ultrasonography, X-ray, computed tomography (CT), or magnetic resonance imaging (MRI) findings], as well as conventional bone scans, are helpful in the screening of local lesions but are relatively nonspecific and/or not sensitive enough. Scintigraphic techniques using radiolabeled serum amyloid P component (SAP) or the radiolabeled A beta(2)M precursor protein, beta(2)M, generate more specific results. A beta(2)M deposits have been visualized in several long-term hemodialysis patients by using (123)I-labeled SAP. However, this scan did not show tracer accumulation in some frequently involved sites such as hips or shoulders, and frequently labeled the spleen, which is usually spared from A beta(2)M deposits. Improvements in technical sensitivity and specificity could be achieved by scanning with (131)I-labeled beta(2)M: this technique detected tracer accumulations corresponding to the typical distribution pattern of A beta(2)M. Further, both the radiation exposure and the optical resolution of this latter scan have been refined by substituting (111)In for (131)I. In a final step we generated recombinant human beta(2)M (rh beta(2)M). While (111)In rh beta(2)M again failed to show significant tracer accumulation over joint regions in patients on short-term hemodialysis without evidence of A beta(2)M, local tracer accumulations similar to those observed with natural, (111)In-labeled beta(2)M could be demonstrated in long-term hemodialysis patients with evidence of A beta(2)M. In conclusion, scintigraphy for A beta(2)M with (111)In-labeled rh beta(2)M provides a homogeneous and safe recombinant protein source and represents a suitable detection method of beta(2)M amyloid deposits in dialysis patients.
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Affiliation(s)
- M Ketteler
- Division of Nephrology, University Hospital of Aachen Technical University, Aachen, Germany
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Radermacher J, Chavan A, Bleck J, Vitzthum A, Stoess B, Gebel MJ, Galanski M, Koch KM, Haller H. Use of Doppler ultrasonography to predict the outcome of therapy for renal-artery stenosis. N Engl J Med 2001; 344:410-7. [PMID: 11172177 DOI: 10.1056/nejm200102083440603] [Citation(s) in RCA: 590] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Prospectively identifying patients whose renal function or blood pressure will improve after the correction of renal-artery stenosis has not been possible. We evaluated whether a high level of resistance to flow in the segmental arteries of both kidneys (indicated by resistance-index values of at least 80) can be used prospectively to select appropriate patients for treatment. METHODS We evaluated 5950 patients with hypertension for renal-artery stenosis using color Doppler ultrasonography, and we measured the resistance index ([1 - end-diastolic velocity divided by maximal systolic velocity] x 100). Among 138 patients who had unilateral or bilateral renal-artery stenosis of more than 50 percent of the luminal diameter and who underwent renal angioplasty or surgery, the procedure was technically successful in 131 (95 percent). Creatinine clearance and 24-hour ambulatory blood pressure were measured before renal-artery stenosis was corrected; 3, 6, and 12 months after the procedure; and yearly thereafter. The mean (+/-SD) duration of follow-up was 32+/-21 months. RESULTS Among the 35 patients (27 percent) who had resistance-index values of at least 80 before revascularization, the mean arterial pressure did not decrease by 10 mm Hg or more after revascularization in 34 (97 percent). Renal function declined (defined by a decrease in the creatinine clearance; of at least 10 percent) in 28 (80 percent); 16 (46 percent) became dependent on dialysis and 10 (29 percent) died during follow-up. Among the 96 patients (73 percent) with a resistance-index value of less than 80, the mean arterial pressure decreased by at least 10 percent in all but 6 patients (6 percent) after revascularization; renal function worsened in only 3 (3 percent), all of whom became dependent on dialysis; and 3 (3 percent) died (P<0.001 for the comparison with patients with a resistance-index value of at least 80). CONCLUSIONS A renal resistance-index value of at least 80 reliably identifies patients with renal-artery stenosis in whom angioplasty or surgery will not improve renal function, blood pressure, or kidney survival.
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Affiliation(s)
- J Radermacher
- Department of Nephrology, Medizinische Hochschule Hannover, Germany.
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Lonnemann G, Floege J, Kliem V, Brunkhorst R, Koch KM. Extended daily veno-venous high-flux haemodialysis in patients with acute renal failure and multiple organ dysfunction syndrome using a single path batch dialysis system. Nephrol Dial Transplant 2000; 15:1189-93. [PMID: 10910443 DOI: 10.1093/ndt/15.8.1189] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND In the treatment of acute renal failure in patients with multiple organ dysfunction syndrome (MODS), continuous renal replacement therapies (CRRT) are increasingly used because of excellent volume control in the presence of improved cardiovascular stability. Patients with MODS, however, are frequently catabolic and have a high urea generation rate requiring either cost-intensive high-volume CRRT or additional intermittent haemodialysis to provide adequate clearance of small-molecular waste products. We tested the closed-loop batch haemodialysis system (called Genius((R))) for the treatment of acute renal failure in patients with MODS in the intensive care unit. METHODS Blood flow and countercurrent dialysate flow were reduced to 70 ml/min. Thus the 75 l dialysate tank of the Genius((R)) system lasts for 18 h of extended single-path high-flux haemodialysis (18 h-HFD) using polysulphous F60 S((R)) dialysers. Blood pressure, body temperature, and venous blood temperature in the extracorporeal circuit (no heating of the dialysate), ultrafiltration rate, serum urea levels, dialyser urea clearance, and total urea removal were monitored. In addition we tested the bacteriological quality of the spent dialysate at the end of 18-h treatments. RESULTS Twenty patients with acute renal failure and MODS were investigated. Averaged dialyser urea clearance was 59.8 ml/min (equal to 3.6 l/h or 64.8 l/day). Total removal of urea was 14.1+/-6.5 g/day keeping serum levels of urea below 13 mmol/l. Mean arterial pressure remained stable during the 18-h treatments with a mean ultrafiltration rate of 120 ml/h. The temperature in the venous blood tubing dropped by 5+/-0.5 degrees C during the 18-h treatment (0.28 degrees C/h) in the presence of unchanged core temperature in the patients. There was no bacterial growth in 2.5 l of spent dialysate (<0.0004 colony forming units/ml). CONCLUSIONS Extended high-flux dialysis using the Genius((R)) system combines the benefits of CRRT (good cardiovascular stability, sterile dialysate) with the advantages of intermittent dialysis (high urea clearance, low treatment costs). High efficiency, simplicity and flexibility of the system offers the unique opportunity to use the same dialysis machine for extended time periods (18 h) as well as for shorter intermittent renal replacement therapy in critically ill patients.
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Affiliation(s)
- G Lonnemann
- Medizinische Hochschule Hannover, Abteilung Nephrologie, Germany
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