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Corcoran RC, Bailey LB, Brown AN, Buchheit KM, Bensko JC, Laidlaw TM. Utilization of protocols to lower daily aspirin dose before surgical procedures for patients with aspirin-exacerbated respiratory disease. J Allergy Clin Immunol Pract 2024:S2213-2198(24)00285-X. [PMID: 38508337 DOI: 10.1016/j.jaip.2024.03.022] [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] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/08/2024] [Accepted: 03/11/2024] [Indexed: 03/22/2024]
Affiliation(s)
- Rose C Corcoran
- Division of Allergy and Clinical Immunology, and the Jeff and Penny Vinik Center, Brigham and Women's Hospital, Boston, Mass
| | - Laura B Bailey
- Division of Allergy and Clinical Immunology, and the Jeff and Penny Vinik Center, Brigham and Women's Hospital, Boston, Mass
| | - Alyson N Brown
- Division of Allergy and Clinical Immunology, and the Jeff and Penny Vinik Center, Brigham and Women's Hospital, Boston, Mass
| | - Kathleen M Buchheit
- Division of Allergy and Clinical Immunology, and the Jeff and Penny Vinik Center, Brigham and Women's Hospital, Boston, Mass; Department of Medicine, Harvard Medical School, Boston, Mass
| | - Jillian C Bensko
- Division of Allergy and Clinical Immunology, and the Jeff and Penny Vinik Center, Brigham and Women's Hospital, Boston, Mass
| | - Tanya M Laidlaw
- Division of Allergy and Clinical Immunology, and the Jeff and Penny Vinik Center, Brigham and Women's Hospital, Boston, Mass; Department of Medicine, Harvard Medical School, Boston, Mass.
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Brown AN, Laidlaw TM, Buchheit KM, Bensko JC, Corcoran RC, Bailey LB. Efficacy of various dosing frequencies of dupilumab in patients with aspirin-exacerbated respiratory disease. J Allergy Clin Immunol Pract 2024:S2213-2198(24)00272-1. [PMID: 38484871 DOI: 10.1016/j.jaip.2024.03.011] [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] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 04/02/2024]
Affiliation(s)
- Alyson N Brown
- Division of Allergy and Clinical Immunology, Jeff and Penny Vinik Center, Brigham and Women's Hospital, Boston, Mass
| | - Tanya M Laidlaw
- Division of Allergy and Clinical Immunology, Jeff and Penny Vinik Center, Brigham and Women's Hospital, Boston, Mass; Department of Medicine, Harvard Medical School, Boston, Mass.
| | - Kathleen M Buchheit
- Division of Allergy and Clinical Immunology, Jeff and Penny Vinik Center, Brigham and Women's Hospital, Boston, Mass; Department of Medicine, Harvard Medical School, Boston, Mass
| | - Jillian C Bensko
- Division of Allergy and Clinical Immunology, Jeff and Penny Vinik Center, Brigham and Women's Hospital, Boston, Mass
| | - Rose C Corcoran
- Division of Allergy and Clinical Immunology, Jeff and Penny Vinik Center, Brigham and Women's Hospital, Boston, Mass
| | - Laura B Bailey
- Division of Allergy and Clinical Immunology, Jeff and Penny Vinik Center, Brigham and Women's Hospital, Boston, Mass
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Bailey LB, Brown AN, Corcoran RC, Bensko JC, Buchheit KM, Laidlaw TM. Consequences of NSAID allergy on pain control options for patients with aspirin-exacerbated respiratory disease. J Allergy Clin Immunol Pract 2024:S2213-2198(24)00199-5. [PMID: 38423289 DOI: 10.1016/j.jaip.2024.02.025] [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] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 02/14/2024] [Accepted: 02/16/2024] [Indexed: 03/02/2024]
Affiliation(s)
- Laura B Bailey
- Division of Allergy and Clinical Immunology, Brigham and Women's Hospital, Boston, Mass
| | - Alyson N Brown
- Division of Allergy and Clinical Immunology, Brigham and Women's Hospital, Boston, Mass
| | - Rose C Corcoran
- Division of Allergy and Clinical Immunology, Brigham and Women's Hospital, Boston, Mass
| | - Jillian C Bensko
- Division of Allergy and Clinical Immunology, Brigham and Women's Hospital, Boston, Mass
| | - Kathleen M Buchheit
- Division of Allergy and Clinical Immunology, Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, and the Jeff and Penny Vinik Center, Boston, Mass
| | - Tanya M Laidlaw
- Division of Allergy and Clinical Immunology, Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, and the Jeff and Penny Vinik Center, Boston, Mass.
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Munro MG, Brown AN, Saadat S, Gomez NA, Howard DL, Kahn BS, Stockwell EL, Volker W, Thayn K. 2663 Essentials in Minimally Invasive Gynecology (Emig) Manual Skills Pilot Validation Trial. J Minim Invasive Gynecol 2019. [DOI: 10.1016/j.jmig.2019.09.233] [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: 11/26/2022]
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Brown AN, Ferreira G, Teets CL, Thomason WE, Teutsch CD. Nutritional composition and in vitro digestibility of grass and legume winter (cover) crops. J Dairy Sci 2017; 101:2037-2047. [PMID: 29274974 DOI: 10.3168/jds.2017-13260] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 11/05/2017] [Indexed: 11/19/2022]
Abstract
In dairy farming systems, growing winter crops for forage is frequently limited to annual grasses grown in monoculture. The objectives of this study were to determine how cropping grasses alone or in mixtures with legumes affects the yield, nutritional composition, and in vitro digestibility of fresh and ensiled winter crops and the yield, nutritional composition, and in vitro digestibility of the subsequent summer crops. Experimental plots were planted with 15 different winter crops at 3 locations in Virginia. At each site, 4 plots of each treatment were planted in a randomized complete block design. The 15 treatments included 5 winter annual grasses [barley (BA), ryegrass (RG), rye (RY), triticale (TR), and wheat (WT)] in monoculture [i.e., no legumes (NO)] or with 1 of 2 winter annual legumes [crimson clover (CC) and hairy vetch (HV)]. After harvesting the winter crops, corn and forage sorghum were planted within the same plots perpendicular to the winter crop plantings. The nutritional composition and the in vitro digestibility of winter and summer crops were determined for fresh and ensiled samples. Growing grasses in mixtures with CC increased forage dry matter (DM) yield (2.84 Mg/ha), but the yield of mixtures with HV (2.47 Mg/ha) was similar to that of grasses grown in monoculture (2.40 Mg/ha). Growing grasses in mixtures with legumes increased the crude protein concentration of the fresh forage from 13.0% to 15.5% for CC and to 17.3% for HV. For neutral detergent fiber (NDF) concentrations, the interaction between grasses and legumes was significant for both fresh and ensiled forages. Growing BA, RY, and TR in mixtures with legumes decreased NDF concentrations, whereas growing RG and WT with legumes did not affect the NDF concentrations of either the fresh or the ensiled forages. Growing grasses in mixtures with legumes decreased the concentration of sugars of fresh forages relative to grasses grown in monoculture. Primarily, this decrease can be attributed to low concentrations of sugars of mixtures with HV (10.5%). Growing grasses in mixtures with legumes reduced the fiber digestibility of both winter crops (75.7% to 72.8% NDF). Growing grasses in mixtures with legumes did not affect estimated DM yield, nutritional composition, or digestibility of the succeeding summer crops. In conclusion, growing grasses in mixtures with legumes as winter forage crops can increase forage estimated DM yields and its nutritional quality in dairy farming sytems.
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Affiliation(s)
- A N Brown
- Department of Dairy Science, Soil Environmental Sciences, Virginia Tech, Blacksburg 24061
| | - G Ferreira
- Department of Dairy Science, Soil Environmental Sciences, Virginia Tech, Blacksburg 24061.
| | - C L Teets
- Department of Dairy Science, Soil Environmental Sciences, Virginia Tech, Blacksburg 24061
| | - W E Thomason
- Department of Crop and Soil Environmental Sciences, Virginia Tech, Blacksburg 24061
| | - C D Teutsch
- Southern Piedmont Agricultural Research and Extension Center, Virginia Tech, Blackstone 23824
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Abstract
Mantle-cell lymphoma is an uncommon lymphoid malignancy of B-cells. It is often aggressive and prognosis is poor. A 69-year-old gentleman with a history of ischaemic heart disease was referred from primary care with a painless right floor of mouth swelling that had been present for 1 month. He otherwise completely asymptomatic. Incisional biopsy of the lesion was undertaken and marker studies demonstrated mantle cell lymphoma. Positron emission tomography-computed tomography and bone marrow biopsy showed widespread but low volume involvement. The patient was referred to the haematology multidisciplinary team for further assessment and treatment.
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Affiliation(s)
| | - A M Power
- Leeds Dental Institute, Leeds General Infirmary , Leeds , UK
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Parmar JD, Hunjan PS, Brown AN, Telfer MR. Honey dressing use for the management of split thickness skin graft donor sites: a technical note. Br J Oral Maxillofac Surg 2012; 51:e40-1. [PMID: 22677213 DOI: 10.1016/j.bjoms.2012.01.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 01/31/2012] [Indexed: 11/28/2022]
Affiliation(s)
- J D Parmar
- Oral and Maxillofacial Surgery Unit, York Teaching Hospital NHS Foundation Trust, The York Hospital, Wigginton Road, York YO31 8HE, United Kingdom.
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Spate LD, Redel BK, Brown AN, Murphy CN, Prather RS. Replacement of bovine serum albumin with N-methyl-D-aspartic acid and homocysteine improves development, but not live birth. Mol Reprod Dev 2012; 79:310. [PMID: 22407887 DOI: 10.1002/mrd.22032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 02/23/2012] [Indexed: 11/06/2022]
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Gore JE, Brown AN. Scleroderma renal crisis sine scleroderma in pregnancy: a case report. Clin Exp Rheumatol 2006; 24:87-8. [PMID: 16539825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Scleroderma renal crisis has been documented as the presenting manifestation of systemic sclerosis sine scleroderma in pregnancy only once in the literature. Unfortunately, since scleroderma renal crisis in sine scleroderma pregnant patients is so rare, that patient expired. We present a case of a sine scleroderma pregnant patient with an initial manifestation of scleroderma renal crisis surviving due to successful diagnosis and treatment.
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Affiliation(s)
- J E Gore
- Rheumatology-Immunology Department, Medical University of South Carolina, Charleston, 29425, USA
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Brown AN, Bolster MB. Scleroderma renal crisis in pregnancy associated with massive proteinuria. Clin Exp Rheumatol 2003; 21:114-6. [PMID: 12673902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Scleroderma renal crisis is a well-recognized complication of systemic sclerosis (SSc) usually occurring early in the course of the disease in patients with diffuse skin involvement. We report the diagnostic challenge of a case of scleroderma renal crisis associated with massive proteinuria at approximately 20 weeks gestation in a pregnant patient with diffuse cutaneous systemic sclerosis.
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Affiliation(s)
- A N Brown
- Department of Medicine, Division of Rheumatology and Immunology, Medical University of South Carolina, 96 Jonathan Lucas Street, Suite 912, Charleston, South Carolina 29425, USA.
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Abstract
Our previous studies have demonstrated that peritoneal macrophages obtained from endotoxin-tolerant rats exhibit altered cellular activation by endotoxin, possibly involving changes in guanine nucleotide regulatory (G) protein-coupled signal transduction pathways. Endotoxin-tolerant rats also exhibit cross tolerance and altered hemodynamic responses to thromboxane (Tx)A2 mimetics, suggesting potential changes in vascular responsiveness. We tested the hypothesis that endotoxin tolerance results in vascular hyporesponsiveness to a TxA2 mimetic via alterations in the TxA2 receptor, G protein function, and/or second messenger production. Rats were rendered endotoxin tolerant by increasing sublethal consecutive doses of Salmonella enteritidis endotoxin (100 to 5000 micrograms/kg, i.p.) for 4 days. The animals were sacrificed 2 days after the final dose of endotoxin for removal of aortas. Contractile responses of aortic rings to U46619, a TxA2 agonist, were assessed in control and tolerant rats. The EC50 values for U46619 were 14.8 +/- 6.6 nM and 32.3 +/- 3.1 nM (n = 5-7), (P < 0.05) for control and tolerant rats, respectively. Crude membranes were prepared from aortas of control and tolerant rats, and binding of I-BOP TxA2/PGH2 receptor agonist, [1S-(1 alpha, 2 beta (5Z), 3 alpha (1E, 3S*), 4 alpha)]-7-[3-(3-hydroxy-4-(4'-iodophenoxy)-1-butenyl)-7- oxabicyclo-[2.2.1]heptan-2-yl]-5-heptenoic acid (I-BOP), a TxA2 agonist, was assessed by Scatchard analysis. I-BOP binding to the TxA2 receptor was saturable and revealed a single class of TxA2 receptors for both groups. There was no significant difference in control (n = 7) compared with tolerant (n = 5) Kd values (2.1 +/- 0.2 vs. 2.4 +/- 0.9 nM, respectively), or Bmax (31 +/- 6 vs. 28 +/- 12 fmol/mg protein, respectively). To assess potential changes in G protein function, aortic membrane GTpase activity was determined. GTPase activity in tolerant membranes was significantly reduced (P < 0.05) compared with control membranes (309 +/- 23 (n = 5) vs. 440 +/- 32 (n = 7) pmol/mg/protein/min, respectively). However, U46619-stimulated phosphoinositide production was similar in vascular tissue from control and tolerant rats. These observations suggest that the decreased contractile response to TxA2 mimetics in endotoxin tolerance does not result from a change in receptor number, affinity of TxA2 receptors, or changes in phosphatidylinositol metabolism but is associated with decreased vascular G protein function.
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Affiliation(s)
- G E Tempel
- Department of Physiology, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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Johnston SC, Fung LH, Gillum LA, Smith WS, Brass LM, Lichtman JH, Brown AN. Utilization of intravenous tissue-type plasminogen activator for ischemic stroke at academic medical centers: the influence of ethnicity. Stroke 2001; 32:1061-8. [PMID: 11340210 DOI: 10.1161/01.str.32.5.1061] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.5] [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: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE We sought to measure the overall rate of usage of tissue-type plasminogen activator (tPA) for ischemic stroke at academic medical centers, and to determine whether ethnicity was associated with usage. METHODS Between June and December 1999, 42 academic medical centers in the United States each identified 30 consecutive ischemic stroke cases. Medical records were reviewed and information on demographics, medical history, and treatment were abstracted. Rates of tPA use were compared for African Americans and whites in univariate analysis and after adjustment for age, gender, stroke severity, and type of medical insurance with multivariable logistic regression. RESULTS Complete information was available for 1195 ischemic stroke patients; 788 were whites and 285 were African Americans: Overall, 49 patients (4.1%) received tPA. In the subgroup of 189 patients without a documented contraindication to therapy, 39 (20.6%) received tPA. Ten (20%) of those receiving tPA had documented contraindication. African Americans were one fifth as likely to receive tPA as whites (1.1% African Americans versus 5.3%; P=0.001), and the difference persisted after adjustment (OR 0.21, 95% CI 0.06 to 0.68; P=0.01). When comparison was restricted to those without a documented contraindication to tPA, the difference remained significant (OR 0.24, 95% CI 0.06 to 0.93; P=0.04). Medical insurance type was independently associated with tPA treatment. After adjustment for ethnicity and other demographic characteristics, those with Medicaid or no insurance were one ninth as likely to receive tPA as those with private medical insurance (OR 0.11, 95% CI 0.02 to 0.17; P=0.003). CONCLUSIONS tPA is used infrequently for ischemic stroke at US academic medical centers, even among qualifying candidates. African Americans are significantly less likely to receive tPA for ischemic stroke. Contraindications to treatment do not appear to account for the difference.
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Affiliation(s)
- S C Johnston
- Neurovascular Service, Department of Neurology, University of California, San Francisco, CA 94143-0114, USA.
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Abstract
Engineering new tissues using cell transplantation may provide a valuable tool for reconstructive surgery applications. Chondrocyte transplantation in particular has been successfully used to engineer new tissue masses due to the low metabolic requirements of these cells. However, the engineered cartilaginous tissue is too rigid for many soft tissue applications. We propose that hybrid tissue engineered from chondrocytes and smooth muscle cells could reflect mechanical properties intermediate between these two cell types. In this study, rat aortic smooth muscle cells and pig auricular chondrocytes were co-cultured on polyglycolic acid fiber-based matrices to address this hypothesis. Mixed cell suspensions were seeded by agitating the polymer matrices and a cell suspension with an orbital shaker. After seeding, cell-polymer constructs were cultured in stirred bioreactors for 8 weeks. The cell density and extracellular matrix (collagen, elastin, and glycosaminoglycan) content of the engineered tissues were determined biochemically. After 8 weeks in culture, the hybrid tissue had a high cell density (5.8 x 108 cells/cm(3)), and elastin (519 microg/g wet tissue sample), collagen (272 microg/g wet tissue sample), and glycosaminoglycan (GAG; 10 microg/g wet tissue sample) content. Mechanical testing indicated the compressive modulus of the hybrid tissues after 8 weeks to be 40.8 +/- 4.1 kPa and the equilibrium compressive modulus to be 8.4 +/- 0.8 kPa. Thus, these hybrid tissues exhibited intermediate stiffness; they were less stiff than native cartilage but stiffer than native smooth muscle tissue. This tissue engineering approach may be useful to engineer tissues for a variety of reconstructive surgery applications.
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Affiliation(s)
- A N Brown
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan, USA
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Abstract
We evaluate the ability of a microcomputer program (Automatch) to link patient records in our hospital's database (N = 253,836) with mortality files from California (N = 1,312,779) and the U.S. Social Security Administration (N = 13,341,581). We linked 96.5% of 3,448 in-hospital deaths, 99.3% for patients with social security numbers. None of 14,073 patients known to be alive (because they were subsequently admitted) was linked with California deaths, and only 6 (0.1%) of 6,444 were falsely identified as dead in the United States file. For patients with unknown vital status but items in the database likely to be associated with high 3-year mortality rates, we identified death records of 88% of 494 patients with cancer metastatic to the liver, 84% of 164 patients with pancreatic cancer, and 91% of 126 patients with CD4 counts of less than 50. Hospital data can be accurately linked with state and national vital statistics using commercial record linkage software.
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Affiliation(s)
- T B Newman
- Department of Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco 94143, USA.
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Bauer DC, Brown AN. Sensitive thyrotropin and free thyroxine testing in outpatients. Are both necessary? Arch Intern Med 1996; 156:2333-7. [PMID: 8911240] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND The appropriate use of specific thyroid function tests to detect thyroid dysfunction remains controversial; some experts recommend both a sensitive thyrotropin (sTSH) test and a free thyroxine (FT4) test, while others recommend an sTSH test alone. OBJECTIVE To determine how often sTSH and FT4 tests are ordered simultaneously, how often the results are discordant, and under what circumstances a single test of thyroid function may be sufficient to rule out thyroid dysfunction. METHODS Retrospective descriptive study of all sTSH and FT4 tests performed on adult outpatients during a 6-month period. If both sTSH and FT4 tests were performed on a single serum specimen, the results were classified as concordant (both tests indicating hypothyroidism, hyperthyroidism, or euthyroidism) or discordant. Chart review was performed on patients with normal sTSH results and abnormal FT4 results. RESULTS A total of 6551 sTSH and 3518 FT4 tests were performed during the study period. Both sTSH and FT4 tests were ordered together on 3143 specimens (48% and 89% of the total number of sTSH and FT4 tests ordered, respectively) from 2629 patients. Of the sTSH results, 69.8% were within the normal range, and 92.7% of the FT4 results were normal. The concordance between sTSH and FT4 results was 74.3%. Among the 1835 specimens with normal sTSH results, FT4 level was low in 11 patients (0.6%; 95% confidence interval, 0.3%-0.9%) and high in 24 (1.3%; 95% confidence interval, 0.8%-1.8%). Chart review did not disclose any instances when an abnormal FT4 results contributed to the treatment of an individual with a normal sTSH result. CONCLUSIONS The sTSH test alone, and not the combination of sTSH and FT4 tests, should be ordered in most outpatients. An FT4 test should not be routinely ordered if the sTSH result is normal; at our institution this approach would obviate the need for at least half of the FT4 tests performed each year.
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Affiliation(s)
- D C Bauer
- Department of Medicine, University of California, San Francisco, USA
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Mozes B, Easterling MJ, Sheiner LB, Melmon KL, Kline R, Goldman ES, Brown AN. Case-mix adjustment using objective measures of severity: the case for laboratory data. Health Serv Res 1994; 28:689-712. [PMID: 8113053 PMCID: PMC1069976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
OBJECTIVE We evaluate the use of routinely gathered laboratory data to subclassify surgical and nonsurgical major diagnostic categories into groups homogeneous with respect to length of stay (LOS). DATA SOURCES AND STUDY SETTING The source of data is the Combined Patient Experience database (COPE), created by merging data from computerized sources at the University of California San Francisco (UCSF) Medical Center and Stanford University Medical Center for a total sample size of 73,117 patient admissions. STUDY DESIGN The study is cross-sectional and retrospective. All data were extracted from COPE consecutive admissions; the unit of analysis is an admission. The outcome variable LOS proxies hospital resource utilization for an inpatient stay. Nine (candidate) predictor variables were derived from seven lab tests (WBC, Na, K, C02, BUN, ALB, HCT) by recording the whole-stay minimum or maximum test result. DATA COLLECTION/EXTRACTION METHODS Patient groups were formed by first assigning to major diagnostic categories (MDCs) all 73,117 admissions. Each MDC was then partitioned into medical and surgical subgroups (sub-MDCs). The 13 sub-MDCs selected for study define a study population of 32,599 patients that represents approximately 45 percent of inpatients. Within each of the 13 sub-MDCs, patients were randomly assigned to one of two data sets in a ratio of 2:1. The first set was used to create, the second to validate, three different LOS predictors. Predictive accuracies of individual DRG classes were compared with those of two alternative classification schemes, one formed by recursive partitioning (the sub-MDC) using only lab test results, the other by partitioning with both lab test results and individual DRGs. PRINCIPAL FINDINGS For the eight largest sub-MDCs (81 percent of study population), individual DRGs explained 23 percent of the within sub-MDC variance in LOS, laboratory data classes explained 31 percent, and classes derived by considering individual DRGs and laboratory data explained 37 percent. (Each result is a weighted average R2. The average number of LOS classes into which the eight largest sub-MDCs were partitioned were 20, 10, and 10, respectively. Within six of the eight, partitioning on the basis of laboratory data alone explained more within sub-MDC variance than did partitioning into individual DRGs. CONCLUSIONS Routine lab test data improve the accuracy of LOS prediction over that possible using DRG classes. We note that the improvements do not result from overfitting the data, since the numbers of LOS classes we use to predict LOS are considerably fewer than the numbers of individual DRGs.
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Affiliation(s)
- B Mozes
- Department of Laboratory Medicine, University of California San Francisco (UCSF) School of Medicine 94143-0626
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Kapp DS, Brown AN, Cox W, Cox RS. Temperature differentials between treatment and pretreatment temperatures correlate with local control following radiotherapy and hyperthermia. Int J Radiat Oncol Biol Phys 1993; 27:331-44. [PMID: 8407408 DOI: 10.1016/0360-3016(93)90245-q] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
PURPOSE To evaluate the influence of pretreatment tumor temperatures and the temperature differential between treatment and pretreatment temperatures on local tumor control in patients who underwent combined radiation therapy and hyperthermia. METHODS AND MATERIALS Mapped intratumoral temperatures were measured immediately prior to and during hyperthermia in 138 hyperthermia fields among 59 patients with nodular (60 fields) or diffuse (78 fields) superficially-located tumors. In the nodular subgroup there were 40 fields with adenocarcinomas (31 breast, two prostate, seven other primary sites), six melanomas, nine squamous cell carcinomas, and five other histologies. The fields with diffuse tumor involvement consisted of 77 adenocarcinomas (67 breast, 10 other) and one melanoma. The maximum, minimum, and average temperatures were determined for both the pretreatment (pTmax, pTmin, pTave) and treatment (Tmax, Tmin, Tave) distributions and the differences, Dm = Tmin-pTmax, and Da = Tmin-pTave, computed. These quantities were averaged over treatments to produce the corresponding mean quantities for each hyperthermia field. Univariate and multivariate analyses were performed to determine treatment and pretreatment parameters which best correlated with the duration of local control. RESULTS Pretreatment tumor temperatures were significantly lower than the oral temperatures with mean pTmax, mean pTmin, and mean pTave of 36.2 degrees C, 34.2 degrees C, and 35.4 degrees C, respectively. For the adenocarcinomas with diffuse involvement within the hyperthermia field, the covariates best correlating with local control duration on univariate analysis were concurrent radiation dose (p = 0.0026), Dm (p = 0.009), pTmax (p = 0.012) and Da (p = 0.036). Lower pTmax and larger Dm and Da were predictive for longer local control. In multivariate analyses, all thermal parameters lost power, however, the best model included Dm which was significant at the p = 0.040 level. For the nodular subgroup, nonthermal parameters and dichotomized thermal parameters were of prognostic significance for local control. CONCLUSION For fields diffusely involved with adenocarcinoma significant correlations with duration of local control have been demonstrated both for a) low pretreatment temperatures and b) large differentials between treatment and pretreatment intratumoral temperatures. These correlations were also found in a dichotomized description for fields with nodular tumors. The results support the concept that pretreatment hypothermic conditions can lead to an increase in thermal sensitization and may help explain the excellent clinical results noted in the treatment of superficial tumors with radiation and hyperthermia. Further exploitation of this approach by planned cooling of superficially-located recurrent tumors prior to hyperthermia treatment warrants investigation.
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Affiliation(s)
- D S Kapp
- Department of Radiation Oncology, Stanford University School of Medicine, CA 94305
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Hurd WW, Randolph JF, Ansbacher R, Menge AC, Ohl DA, Brown AN. Comparison of intracervical, intrauterine, and intratubal techniques for donor insemination. Fertil Steril 1993; 59:339-42. [PMID: 8425628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE To compare the efficacy of intracervical insemination (ICI), intrauterine insemination (IUI), and a combination of intratubal and intrauterine insemination (ITI/IUI) for donor insemination. DESIGN Prospective randomized clinical trial. SETTING The University of Michigan donor insemination program. PATIENTS, PARTICIPANTS Forty-one women undergoing donor insemination with cryopreserved sperm for either isolated male factor or male factor plus ovulatory dysfunction corrected by clomiphene citrate. INTERVENTION Each patient was randomly assigned to receive each of the three insemination techniques in consecutive cycles until pregnancy occurred or the patient dropped from the study. MAIN OUTCOME MEASURES Cycle fecundity rates were compared using the chi 2 test, and cumulative pregnancy rates (PRs) determined by life table analysis were compared using a log-rank test. RESULTS Cycle fecundity rate was significantly higher for IUI (18.3%) than for ICI (3.9%) or ITI/IUI (7.3%). By life table analysis, the cumulative PR for IUI was significantly higher than for ICI, but the PR for ITI/IUI was not. CONCLUSION For donor insemination with cryopreserved sperm, IUI increases cycle fecundity compared with ICI. The addition of ITI to IUI, however, interferes with the apparent beneficial effect of IUI alone.
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Affiliation(s)
- W W Hurd
- Department of Obstetrics and Gynecology, University of Michigan Medical Center, Ann Arbor 48109-0718
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19
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Brown AN, Sheiner LB, Cohen SN. Evaluation of bilirubin in a liver screening panel. JAMA 1992; 268:1542. [PMID: 1518108] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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20
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Brown AN, Willcox HN. Greatly improved recovery of in vitro B-memory cell function after enzymic dispersion of immunized mouse spleens. Immunology 1991; 74:600-5. [PMID: 1783419 PMCID: PMC1384767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We have used the protease dispase to disperse the fine clumps that persist after mechanical disruption of spleens from immunized mice. After 4-8 days in culture, the resulting 'D/C' cells spontaneously generated many more IgG plaque-forming cells (PFC) against sheep erythrocytes (SRBC) than did conventional (CONV) suspensions. The difference averaged 12-fold and was consistently high after a wide range of immunization protocols. The major difference between the two cell preparations proved to be in the B-cell lineage rather than in antigen-presenting cells or T cells and, indeed, the response was largely T-cell independent. Antigen-driven culture responses to SRBC were also more than 10-fold higher with D/C than with CONV suspensions, and again there was apparently an improved recovery of B-memory cells. However, when fresh cell preparations were assayed immediately for PFC, there was no D/C:CONV difference--just as we have previously reported for memory responses on cell transfer to irradiated recipients. One simple interpretation is that germinal centres tend to remain as fine clumps on mechanical disruption, and their constituent B-memory cells are enriched by our procedure. If so, their responses are much more evident in vitro than after cell transfer.
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Affiliation(s)
- A N Brown
- Department of Neurological Science, Royal Free Hospital School of Medicine, London
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21
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Wiseman MN, Elstob JE, Francis RJ, Brown AN, Rajaguru S, Steiner J, Dymond DS. Initial and steady state pharmacokinetics of cilazapril in congestive cardiac failure. J Pharm Pharmacol 1991; 43:406-10. [PMID: 1681053 DOI: 10.1111/j.2042-7158.1991.tb03498.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Twenty one patients with NYHA class II-III congestive heart failure received single ascending doses of 0.5, 1.25 and 2.5 mg cilazapril daily followed by the minimum effective dose for six weeks. Fifteen patients completed the study, but the data from only 11 were sufficiently complete for kinetic evaluation. The pharmacokinetics of the metabolite, cilazaprilat, after a single dose of 0.5 mg cilazapril were similar to previous observations in healthy volunteers at identical dosage. Repeat administration, however, led to greater accumulation than previously observed in volunteers at the higher dosages of 1.25 or 5 mg given for 8 days. Seven patients experienced adverse events. Four were severe, leading to withdrawal of the patients from the study, but only one event was related to cilazapril. Of the other three, one suffered a myocardial infarction and subsequently died due to worsening congestive heart failure. One other patient was withdrawn with two adverse events probably related to cilazapril. No other deaths occurred amongst the study population, and there were no significant abnormalities in haematology or blood chemistry.
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22
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O'Hare M, Brown AN, Hussain K, Gebhardt A, Watson G, Roberts LM, Vitetta ES, Thorpe PE, Lord JM. Cytotoxicity of a recombinant ricin-A-chain fusion protein containing a proteolytically-cleavable spacer sequence. FEBS Lett 1990; 273:200-4. [PMID: 2121540 DOI: 10.1016/0014-5793(90)81084-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Chimeric proteins composed of ricin toxin A chain (RTA) and staphylococcal protein A (PA) have been produced in E. coli. Constructs consisting of N-terminal RTA and C-terminal PA (RTA-PA) or N-terminal PA and C-terminal (PA-RTA) were capable of binding to immunoglobulin G (via PA) and of specifically depurinating 28 S ribosomal RNA (via RTA). However, neither fusion protein was cytotoxic to antigen-bearing target cells in the presence of an appropriate monoclonal antibody presumably because the RTA could not be released from the PA within the cytosol where the ribosomal substrate of RTA is located. The overcome this, a short amino acid sequence from diphtheria toxin was engineered between the RTA and PA to produce a disulfide-linked loop containing a trypsin sensitive cleavage site. Cleavage of this fusion protein with trypsin converted the RTA-DT-PA to the two chain form consisting of RTA linked by a disulfide bond to PA. The cleaved fusion protein was highly toxic to Daudi cells coated with anti-immunoglobulin antibody suggesting that the RTA could be released from the PA by reduction within the cytosol.
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Affiliation(s)
- M O'Hare
- Department of Biological Sciences, University of Warwick, Coventry, UK
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23
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Williams PE, Brown AN, Rajaguru S, Francis RJ, Bell AJ, Dewland PM. Pharmacokinetics of cilazapril during repeated oral dosing in healthy young volunteers. Eur J Drug Metab Pharmacokinet 1990; 15:63-7. [PMID: 2166672 DOI: 10.1007/bf03190129] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The pharmacokinetics of cilazapril and its active metabolite cilazaprilat in plasma were investigated in an open study of 13 healthy male volunteers, aged 18 to 43 years. One capsule containing 2.5 mg cilazapril was administered to each volunteer daily for 8 days. Plasma samples were obtained after the first and eighth doses. Concentrations of cilazapril, cilazaprilat and activities of angiotensin converting enzyme (ACE) were measured by radioenzymatic methods. For cilazapril, the values of apparent plasma clearance (about 15 l/h) and volume of distribution (around 28 l) were sufficiently high to suggest that significant pre-systemic hydrolysis to cilazaprilat occurred. There were no significant changes in these values after repeated dosing. There were small, but statistically significant, increases in mean peak concentrations, mean areas under concentration-time curves and mean trough concentrations from the first to the eighth dose. A steady state was achieved after eight doses with an accumulation of 20-30%. The mean effective half-life was approximately 9 h. Despite the accumulation of cilazaprilat in plasma, there were no significant differences in plasma ACE inhibition from the first to the eighth dose.
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Affiliation(s)
- P E Williams
- Roche Products Ltd, Welwyn Garden City, Herts, UK
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24
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Willcox N, Schluep M, Sommer N, Campana D, Janossy G, Brown AN, Newsom-Davis J. Variable corticosteroid sensitivity of thymic cortex and medullary peripheral-type lymphoid tissue in myasthenia gravis patients: structural and functional effects. Q J Med 1989; 73:1071-87. [PMID: 2623139] [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: 01/01/2023]
Abstract
The thymus has been studied in myasthenia gravis patients to assess the effects of previous immunosuppression on total yields of cell suspension, immunohistology and culture responses. The reduction in cell yields by pretreatment with corticosteroid was very variable. In 16 of 32 cases, cortical, medullary and total cell numbers were all greatly reduced ('depleted cases'), whereas in the others, they were within or near the typical range for untreated myasthenics. Cortical thymocytes were even more depleted than precursor thymic blasts. Thus the interpatient differences in sensitivity to corticosteroid recently described for mature T cells also affected immature cortical thymocytes and their differentiating medullary progeny. In the medulla, mature (CD3+) T lymphocytes and germinal centres were enriched by the loss of cortex and appeared relatively healthy, but somewhat depopulated. Concomitantly, in-vitro T-cell responses to acetylcholine receptor (AChR) and production of anti-AChR antibody and total IgG by thymic cells were usually well within the typical range (assessed per 10(6) cells). Moreover, the total productivity of the entire thymus was reduced almost entirely by the cellular depopulation rather than by decreased function per surviving cell. Thus the main actions of this alternate day therapy with corticosteroids were apparently on total peripheral cell numbers, and perhaps on activated cells and effector mechanisms too, and its thymic effects were inessential.
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Affiliation(s)
- N Willcox
- Department of Neurological Science, Royal Free Hospital School of Medicine, London
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25
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Abstract
1. Cilazaprilat is an inhibitor of angiotensin converting enzyme (ACE) and is the active metabolite of cilazapril. The pharmacokinetics of cilazaprilat, and the inhibition of plasma ACE were investigated in 12 elderly and 12 young healthy volunteers. 2. Single oral 1 mg doses of cilazapril were given to the elderly (age range 65-83 years) and the young (age range 18-31 years) in an open study. Plasma and urinary cilazaprilat concentrations, and plasma ACE activities were measured up to 72 h after dosing by radioenzymatic methods. 3. Cilazapril was well tolerated in both young and elderly subjects. Small falls in blood pressure were observed up to 8-24 h after dosing. 4. The mean peak plasma cilazaprilat concentration in the elderly (11.5 ng ml-1) was significantly greater (P less than 0.02) than the corresponding value in the young (8.3 ng ml-1). Total and renal clearances were significantly lower (both P less than 0.05) in the elderly (12.8 and 5.11 h-1) than in the young (16.0 and 7.21 h-1). Total urinary recovery of cilazaprilat was similar for the two groups at about 43% of dose. 5. Plasma ACE inhibition was slightly greater in the elderly but the mean inhibition in the two groups did not differ by more than 10% at any time-point from 1-72 h. 6. The plasma concentrations of cilazaprilat required for 90% ACE inhibition were similar at 4.7 and 4.8 ng ml-1 in the elderly and young respectively. 7. It is concluded that the age-related changes in cilazaprilat kinetics and in the degree of ACE inhibition are small.(ABSTRACT TRUNCATED AT 250 WORDS)
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Rosenthal E, Francis RJ, Brown AN, Rajaguru S, Williams PE, Steiner J, Curry PV. A pharmacokinetic study of cilazapril in patients with congestive heart failure. Br J Clin Pharmacol 1989; 27 Suppl 2:267S-273S. [PMID: 2548554 PMCID: PMC1379757 DOI: 10.1111/j.1365-2125.1989.tb03491.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
1. The pharmacokinetics of cilazapril and the inhibition of angiotensin converting enzyme (ACE) were investigated in 10 patients with congestive heart failure, NYHA class II-III, receiving diuretics with or without digoxin. 2. Patients received 0.5 mg and 1 mg cilazapril on the first 2 days, followed by 0.5 mg or 1 mg daily for the next 8 weeks, in a single-blind study. Plasma cilazaprilat concentrations and plasma ACE activities were measured by radioenzymatic methods up to 24 h after the first and last doses. 3. After the initial 0.5 mg dose of cilazapril, a mean maximum plasma concentration of cilazaprilat of 6.8 ng ml-1 was observed at 2.3 h. Concentrations declined up to 8 h with a mean half-life of 5.8 h, followed by slower decrease to 24 h. Total clearance, based on data to 24 h, was estimated at 8.5 l h-1, with three-fold inter-individual variation. Mean maximum plasma ACE inhibition was 87%, decreasing to 65% at 24 h. 4. In the multiple dose phase of the study, four patients received cilazapril 0.5 mg daily, and six patients 1 mg daily. Cilazapril accumulation for the 0.5 mg group averaged 77%, but steady state concentrations for the 1 mg group were less than double those of the 0.5 mg group. ACE inhibition profiles at steady state were similar for both groups, and they differed from first dose data only in a somewhat lower inhibition at 24 h. 5. Historical comparison of the first-dose data with those for healthy young volunteers at identical dosage revealed only minor differences in kinetic parameters.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- E Rosenthal
- Roche Products Ltd, Welwyn Garden City, Hertfordshire
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27
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Williams PE, Brown AN, Rajaguru S, Francis RJ, Walters GE, McEwen J, Durnin C. The pharmacokinetics and bioavailability of cilazapril in normal man. Br J Clin Pharmacol 1989; 27 Suppl 2:181S-188S. [PMID: 2527531 PMCID: PMC1379746 DOI: 10.1111/j.1365-2125.1989.tb03480.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
1. The pharmacokinetics of cilazapril and its active metabolite, cilazaprilat, were investigated in a three-part crossover study in 12 healthy male volunteers aged 19-38 years, excluding one subject who withdrew from the study. 2. Single 2.5 mg oral doses of cilazapril, and equivalent oral and intravenous doses of cilazaprilat were administered as aqueous solutions to the fasted subjects. There was an interval of 1 week between treatments. Concentrations of cilazapril and cilazaprilat in plasma and urine, and activities of angiotensin converting enzyme (ACE) in plasma were measured by radioenzymatic methods. 3. After 10 min infusion of cilazaprilat, the mean plasma concentration was 194 ng ml-1, and ACE inhibition was almost 100%. The decline in concentrations was polyphasic, with mean half-lives for the periods 1-4 h and 24-168 h of 0.90 and 46 h, respectively. Between 4 and 24 h the decline was non-linear, and ACE inhibition decreased from 91% to 67%. Urinary recovery of cilazaprilat averaged 91% of dose. 4. After oral cilazapril, the parent drug was rapidly absorbed and rapidly eliminated, with a mean maximum plasma concentration of 82 ng ml-1 at 0.83 h and a single elimination half-life of 1.3 h. Cilazaprilat peaked at 36 ng ml-1 about 1.7 h after dosing and the decline in concentrations was biphasic, with half-lives of 1.8 h and 45 h. After oral cilazaprilat, plasma concentrations were considerably lower, and the peak later (2.2 h). 5. Urinary recovery data indicated an absolute bioavailability for cilazaprilat of 57% (range 45-75%) from oral cilazapril, but only 19% (range 8-40%) from oral cilazaprilat.(ABSTRACT TRUNCATED AT 250 WORDS)
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28
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Fillastre JP, Moulin B, Godin M, Williams PE, Brown AN, Francis RJ, Pinta P, Manfredi R. Pharmacokinetics of cilazapril in patients with renal failure. Br J Clin Pharmacol 1989; 27 Suppl 2:275S-282S. [PMID: 2527539 PMCID: PMC1379758 DOI: 10.1111/j.1365-2125.1989.tb03492.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
1. The pharmacokinetics of a single 1 mg dose of cilazapril were determined in six subjects with normal renal function and in 19 uraemic patients with various degrees of renal impairment. 2. Significant decreases in systolic and diastolic blood pressure were noted in all groups of subjects between 2 and 8 h after administration of 1 mg cilazapril. 3. There was a significant correlation between ACE inhibition at 24 h and creatinine clearance (CrCL). 4. For cilazapril, Cmax and tmax were independent of creatinine clearance. AUC(24) was inversely related to CrCL and apparent plasma clearance (CL/F) was directly related to CrCL. 5. For cilazaprilat, Cmax and tmax were related to creatinine clearance. AUC(24) was inversely related to CrCl and apparent plasma clearance (CL/F) was directly related to CrCL. 6. Dialysis clearance was approximately 2 l h-1 for cilazapril and for cilazaprilat. 7. The effects of renal impairment on cilazapril and cilazaprilat kinetics were similar to those observed for other inhibitors of angiotensin-converting enzyme such as captopril, enalapril and lisinopril. 8. It may be necessary to modify doses of cilazapril for the treatment of essential hypertension in uraemic patients. When creatinine clearance was below 15 ml min-1 cilazaprilat concentrations were increased, half-lives were prolonged and ACE inhibition remained above 90% for at least 24 h. A reduced dosage is indicated for these patients. 9. In patients requiring haemodialysis, maintenance doses of 0.5 mg given after each haemodialysis session are sufficient.
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Affiliation(s)
- J P Fillastre
- Department of Nephrology, University of Rouen, France
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Abstract
1. The influence of food on the pharmacokinetics and angiotensin-converting enzyme (ACE) inhibitory effects of oral 5 mg doses of cilazapril was investigated in a two-way crossover study in 16 volunteers. 2. Plasma and urine concentrations of cilazaprilat, the active diacid metabolite of cilazapril, and plasma ACE activity were determined by a radio-enzymatic method. 3. Cmax decreased by 30% (P less than 0.05) with a delay in (t)max of 1 h (P less than 0.05) and area under curve (AUC) was decreased by 14% (P less than 0.05). The elimination rate was unaltered. 4. Onset of ACE inhibition was delayed by approximately 30 min but degree and duration were unaffected. 5. The effect of food on the bioavailability of cilazapril at this dose would not be expected to be clinically significant.
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Shen GL, Li JL, Ghetie MA, Ghetie V, May RD, Till M, Brown AN, Relf M, Knowles P, Uhr JW. Evaluation of four CD22 antibodies as ricin A chain-containing immunotoxins for the in vivo therapy of human B-cell leukemias and lymphomas. Int J Cancer 1988; 42:792-7. [PMID: 3263328 DOI: 10.1002/ijc.2910420527] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [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: 01/05/2023]
Abstract
Ricin A chain-containing immunotoxins (IT-As) specific for the human B-cell antigen, CD22, were prepared from 4 monoclonal antibodies (MAbs) or their Fab' fragments: RFB4, HD6, UV22-I and UV22-2. The ITs were tested for their ability to kill cells from the Burkitt lymphoma line, Daudi, the pre-B-cell leukemia line, NALM-6, and the myeloma cell line, ARH-77. Daudi expresses high levels of CD22, whereas NALM-6 and ARH-77 express low levels of CD22. The IgG-RFB4-A was highly toxic to all 3 cell lines; it killed 50% of the Daudi cells at a concentration of 1.2 x 10(-12) M and 50% of NALM-6 and ARH-77 cells at concentrations of 1.5 to 2.1 x 10(-11) M. IgG-RFB4-A was 10-30 times more toxic to Daudi cells than were the IgG-As constructed from the other 3 CD22 MAbs and 10 times more toxic than ricin itself. IT-As constructed from the Fab' fragments of the 4 CD22 antibodies were 2 to 5 times less toxic to Daudi cells than their IgG-A counterparts. Fab'-RFB4-A was twice as toxic to Daudi cells as ricin, whereas the other Fab'-As were about 7 times less toxic than ricin. Scatchard analyses of the binding of the radio-iodinated antibodies to Daudi cells showed that the intact RFB4 antibody bound 3-10 times more strongly than the other antibodies, whereas the Fab'-RFB4 bound 1.2 to 3.5 times more strongly than the Fab' fragments prepared from the other antibodies. Thus, the potent cytotoxic activity of the RFB4-As appears to derive, in part, from their superior binding affinity. Prior studies have shown that UV22-I and HD6 cross-react with certain normal human tissues lacking cells of B-cell lineage, whereas UV22-2 and RFB4 are B-cell-specific. This fact, together with its superior potency as an IT-A, suggests that RFB4 is the antibody of choice for preparing Fab'-As or IgG-As for in vivo therapy of human B-cell leukemias and lymphomas.
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Affiliation(s)
- G L Shen
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235
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Thorpe PE, Wallace PM, Knowles PP, Relf MG, Brown AN, Watson GJ, Blakey DC, Newell DR. Improved antitumor effects of immunotoxins prepared with deglycosylated ricin A-chain and hindered disulfide linkages. Cancer Res 1988; 48:6396-403. [PMID: 3263186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A monoclonal anti-Thy-1.1 antibody (OX7) was coupled to either native or chemically deglycosylated ricin A-chain (dgA) using one of two different cross-linking agents. One cross-linker, N-succinimidyloxycarbonyl-alpha-methyl-alpha-(2-pyridyldithio)tolu ene (SMPT), generates a sterically hindered disulfide bond which is relatively resistant to reduction, whereas the other, 2-iminothiolane hydrochloride, generates an unhindered disulfide bond with greater lability. A two-compartment pharmacokinetic model was used to analyze the blood levels of each immunotoxin and its breakdown product (free antibody) after i.v. injection into mice. Immunotoxins prepared with SMPT broke down in vivo 6.3-fold more slowly than those prepared with 2-iminothiolane hydrochloride, and immunotoxins containing native A-chain were cleared 2- to 3-fold more rapidly from the bloodstream than those containing dgA. As a result, 24 h after injection, 16% of the OX7-SMPT-dgA remained in the blood as compared with 0.4 to 2.5% of the other immunotoxins. Immunotoxins prepared with dgA were about 3-fold more toxic to mice than those prepared with native A-chain, whereas immunotoxins prepared with SMPT were only slightly more toxic than those prepared with 2-iminothiolane hydrochloride. When equivalent toxic doses of the immunotoxins were administered i.v. to mice which had been given injections of Thy-1.1+ AKR-A/2 lymphoma cells, the OX7-SMPT-dgA gave the best antitumor effect. A dose equivalent to one-seventh of the median lethal dose extended the survival time of the animals by the extent expected if 99.999% of the tumor cells had been eradicated. Furthermore, the tumors that did develop in the mice treated with OX7-SMPT-dgA were mutants which were resistant to all the immunotoxins. Some of the mutants were deficient in Thy-1.1 whereas others were not. In conclusion, both the use of the SMPT cross-linker and deglycosylation of the A-chain significantly improve the therapeutic index of the immunotoxins in AKR-A/2 tumor-bearing mice.
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Affiliation(s)
- P E Thorpe
- Drug Targeting Laboratory, Imperial Cancer Research Fund, London, England
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Stirpe F, Wawrzynczak EJ, Brown AN, Knyba RE, Watson GJ, Barbieri L, Thorpe PE. Selective cytotoxic activity of immunotoxins composed of a monoclonal anti-Thy 1.1 antibody and the ribosome-inactivating proteins bryodin and momordin. Br J Cancer 1988; 58:558-61. [PMID: 3265330 PMCID: PMC2246839 DOI: 10.1038/bjc.1988.258] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The ribosome-inactivating proteins, bryodin, from Bryonia dioica, and momordin, from Momordica charantia, were coupled by a disulphide bond to a monoclonal anti-Thy 1.1 antibody (OX7). Both immunotoxins were specifically cytotoxic to the Thy 1.1-expressing mouse lymphoma cell line AKR-A in vitro. The OX7-bryodin immunotoxins were the more powerfully toxic and reduced protein synthesis in AKR-A cells by 50% at a concentration of 1-4 x 10(-11) M as compared with 1 x 10(-9) M for the OX7-momordin immunotoxins. Neither of the immunotoxins was toxic to mouse lymphoma EL4 cells, which lack the Thy 1.1 antigen, at concentrations up to 3 x 10(-8) M. Further, bryodin and momordin immunotoxins made from an antibody (R10) of irrelevant specificity were without effect on AKR-A cells.
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Affiliation(s)
- F Stirpe
- Dipartimento di Patologia Sperimentale, Universita degli Studi di Bologna, Italy
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Abstract
This paper attempts to quantitate immunohistological changes in the myasthenia gravis (MG) thymus and to correlate them with clinical and culture parameters in 40 untreated young onset patients covering a wide range of durations and serum anti-acetylcholine receptor (AChR) antibody titers. Total cellularities of both the thymic cortex and the medulla declined significantly with age. There was some hyperplasia of subcapsular and of medullary epithelial cells, often at the expense of cortex. A combined index of all hyperplastic changes correlated significantly with serum anti-AChR titre. Otherwise histological indices, e.g. of germinal centres (GC) were largely unrelated to any clinical parameters, especially duration of symptoms. Specific anti-AChR synthesis in culture (very closely related to serum titer) correlated better with the medullary lymph node-type T-cell areas; these were more widely prevalent and MG-specific. In contrast, basal and mitogen-stimulated total IgG productivity followed the GC indices more closely. We propose that the variability of GC is due to their dependence on extraneous immune complexes, and we discuss whether they or the T-cell areas are primary or secondary abnormalities. Finally, we conclude that autosensitization in MG with thymic hyperplasia and neoplasia probably arises through separate mechanisms.
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Affiliation(s)
- M Schluep
- Department of Neurological Science, Royal Free Hospital School of Medicine, London
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34
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Affiliation(s)
- A N Brown
- Department of Neurological Science, Royal Free Hospital School of Medicine, London
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Stirpe F, Derenzini M, Barbieri L, Farabegoli F, Brown AN, Knowles PP, Thorpe PE. Hepatotoxicity of immunotoxins made with saporin, a ribosome-inactivating protein from Saponaria officinalis. Virchows Arch B Cell Pathol Incl Mol Pathol 1987; 53:259-71. [PMID: 2889289 DOI: 10.1007/bf02890252] [Citation(s) in RCA: 28] [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] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Immunotoxins were prepared by conjugating saporin, a ribosome-inactivating protein from Saponaria officinalis, to a monoclonal antibody against the Thy1.1 antigen, or to its F(ab')2 fragment. The immunotoxins were eight- to 16-fold more toxic to mice than free saporin. Injection of the immunotoxins induced necrosis of the liver and spleen, whereas free saporin caused necrosis of the epithelium of the kidney tubules. The cytoplasm of the hepatic parenchymal cells was affected by the immunotoxins, lesions being apparent in the rough endoplasmic reticulum and, later, in the mitochondria. These changes were associated with a reduced capacity to synthesise proteins both in the intact liver and by isolated liver microsomes. Studies of the in vivo distribution showed that 90% of the free saporin was removed from the bloodstream, mainly by the kidneys, within 10 min of injection. By contrast, the immunotoxins persisted in the blood for several hours and the only organ in which they consistently accumulated was the liver. The hepatotoxic effect of the immunotoxins was not due to their binding to liver cells via the antigen-binding sites or the Fc-piece of the antibody moiety, nor was it due to hepatic recognition of carbohydrate in the immunotoxin. It is concluded that free saporin, although capable of entering liver cells, is filtered so rapidly by the kidney that liver damage does not occur to a significant extent. Filtered saporin, however, is reabsorbed by renal tubules, whose epithelial cells are damaged. The antibody-saporin conjugate is too large to filter at the glomerulus and so has greater opportunity to penetrate into and to damage the hepatic parenchymal cell.
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Affiliation(s)
- F Stirpe
- Dipartimento di Patologia sperimentale dell'Università di Bologna, Italy
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Thorpe PE, Wallace PM, Knowles PP, Relf MG, Brown AN, Watson GJ, Knyba RE, Wawrzynczak EJ, Blakey DC. New coupling agents for the synthesis of immunotoxins containing a hindered disulfide bond with improved stability in vivo. Cancer Res 1987; 47:5924-31. [PMID: 3499221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Two new coupling agents were synthesized for making immunotoxins containing disulfide bonds with improved stability in vivo: sodium S-4-succinimidyloxycarbonyl-alpha-methyl benzyl thiosulfate (SMBT) and 4-succinimidyloxycarbonyl-alpha-methyl-alpha(2-pyridyldithio)tolue ne (SMPT). Both reagents generate the same hindered disulfide linkage in which a methyl group and a benzene ring are attached to the carbon atom adjacent to the disulfide bond and protect it from attack by thiolate anions. An immunotoxin consisting of monoclonal anti-Thy-1.1 antibody (OX7) linked by means of the SMPT reagent to chemically deglycosylated ricin A-chain had better stability in vivo than an immunotoxin prepared with 2-iminothiolane hydrochloride (2IT) which generates an unhindered disulfide linkage. About 48 h after i.v. injection into mice, one-half of the SMPT-linked immunotoxin present in the blood was in intact form and one-half as released free antibody, whereas equivalent breakdown of the 2IT-linked immunotoxin was seen at about 8 h after injection. Consequently, the blood levels of the SMPT-linked immunotoxin remained higher than those of the 2IT-linked immunotoxin despite loss of immunotoxin from the blood by other mechanisms. Forty-eight h after injection, 10% of the injected dose of the SMPT-linked immunotoxin remained in the bloodstream as compared with only 1.5% of the 2IT-linked immunotoxin. The ability of immunotoxins prepared with the new reagents to inhibit protein synthesis by Thy-1.1-expressing AKR-A/2 lymphoma cells in vitro was identical to that of immunotoxins prepared with 2IT or N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP). Clonogenic assays showed that fewer than 0.01% of AKR-A/2 cells survived exposure to high concentrations of OX7-abrin A-chain immunotoxins prepared with SMBT, 2IT, or SPDP. Twelve clones of cells which had survived treatment with the SMBT-linked immunotoxin were isolated. None of the clones was selectively resistant to the SMBT-linked immunotoxin when retested in cytotoxicity assays. In conclusion, immunotoxins prepared with the new coupling agents should have improved antitumor activity in vivo because they are longer lived and do not break down so readily to release free antibody which could compete for the target antigens.
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Affiliation(s)
- P E Thorpe
- Drug Targeting Laboratory, Imperial Cancer Research Fund, London, England
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Thorpe PE, Blakey DC, Brown AN, Knowles PP, Knyba RE, Wallace PM, Watson GJ, Wawrzynczak EJ. Comparison of two anti-Thy 1.1-abrin A-chain immunotoxins prepared with different cross-linking agents: antitumor effects, in vivo fate, and tumor cell mutants. J Natl Cancer Inst 1987; 79:1101-12. [PMID: 2890786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The A-chain of the plant toxin abrin was covalently linked to monoclonal anti-Thy 1.1 antibody (OX7) with the use of either N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP) or 2-iminothiolane hydrochloride (2IT). The SPDP reagent generates a linkage containing a disulfide bond and an amide bond, whereas the 2IT reagent generates a linkage containing a disulfide bond and an amidinium bond. The two immunotoxins were powerfully and specifically toxic to Thy 1.1-expressing murine AKR-A lymphoma cells in vitro. Both reduced the rate of protein synthesis of the cells by 50% at a concentration of 10(-11) M. However, clonogenic assays revealed that about 1% of the AKR-A cells survived treatment with high concentrations of OX7-SPDP-abrin A, whereas only about 0.1% survived treatment with similar concentrations of OX7-2IT-abrin A. Several clones of the surviving cells were isolated. Of 11 clones of cells that had survived exposure to OX7-SPDP-abrin A, 10 were resistant to further treatment with OX7-SPDP-abrin A but had normal sensitivity to OX7-2IT-abrin A. These clones expressed moderate to high levels of the Thy 1.1 antigen and were fully sensitive to abrin. In contrast, all 10 clones of cells that had survived exposure to OX7-2IT-abrin A were substantially or entirely resistant to both immunotoxins. They expressed low to high levels of the Thy 1.1 antigen and were fully sensitive to abrin. The 2IT-linked immunotoxin was much more effective than the SPDP-linked immunotoxin at protecting nu/nu mice against the growth of AKR-A lymphoma cells in the peritoneal site. A single iv injection of 0.3 nmol OX7-2IT-abrin A eradicated at least 99.99% of the tumor cells, as judged from the extension in the median survival time of the animals, whereas OX7-SPDP-abrin A eradicated only about 99% of the cells. The tumors that developed in the animals that received OX7-2IT-abrin A were Thy 1.1-negative, whereas those in the recipients of OX7-SPDP-abrin A generally expressed normal levels of the Thy 1.1 antigen. The difference in antitumor activity of the immunotoxins was not due to differences in their in vivo fate, inasmuch as they were cleared from the bloodstream at an identical rate and broke down at the same rate to release free antibody.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- P E Thorpe
- Drug Targeting Laboratory, Imperial Cancer Research Fund, London England
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Foxwell BM, Blakey DC, Brown AN, Donovan TA, Thorpe PE. The preparation of deglycosylated ricin by recombination of glycosidase-treated A- and B-chains: effects of deglycosylation on toxicity and in vivo distribution. Biochim Biophys Acta 1987; 923:59-65. [PMID: 3099852 DOI: 10.1016/0304-4165(87)90126-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Deglycosylation of ricin may be necessary to prevent the entrapment of antibody-ricin conjugates in vivo by cells of the reticuloendothelial system which have receptors that recognise the oligosaccharide side chains on the A- and B-chains of the toxin. Carbohydrate-deficient ricin was therefore prepared by recombining the A-chain, which had been treated with alpha-mannosidase, with the B-chain, which had been treated with endoglycosidase H or alpha-mannosidase or both. By recombining treated and untreated chains, a series of ricin preparations was made having different carbohydrate moieties. The removal of carbohydrate from the B-chain did not affect the ability of the toxin to agglutinate erythrocytes, and alpha-mannosidase treatment of the A-chain did not affect its ability to inactivate ribosomes. The toxicity of ricin to cells in culture was only reduced in those preparations containing B-chain that had been treated with alpha-mannosidase, when a 75% decrease in toxicity was observed. The toxicity of the combined ricin preparation to mice varied from double to half that of native ricin, depending on the chain(s) treated and the enzymes used. Removal of carbohydrate greatly reduced the hepatic clearance of the toxin and the levels of toxin in the blood were correspondingly higher. These results suggest that antibody-ricin conjugates prepared from deglycosylated ricin would be cleared more slowly by the liver, inflict less liver damage, and have greater opportunity to reach their target.
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Francis RJ, Brown AN, Kler L, Fasanella d'Amore T, Nussberger J, Waeber B, Brunner HR. Pharmacokinetics of the converting enzyme inhibitor cilazapril in normal volunteers and the relationship to enzyme inhibition: development of a mathematical model. J Cardiovasc Pharmacol 1987; 9:32-8. [PMID: 2434791] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The pharmacokinetics of the new converting enzyme inhibitor cilazapril were investigated in 12 healthy male volunteers. Single oral doses of 1.25, 2.5, 5, and 10 mg of cilazapril were tested in groups of six subjects, each of whom received two different doses. A 2-week interval was allowed between treatments. Plasma levels of cilazaprilat, the active form of cilazapril, were measured for up to 3 days after drug administration. Peak plasma levels and 24-h areas under the curve (AUCs) were almost directly proportional to dose, and the elimination half-life (t1/2) during the first 8 h after dosing was 1.5 h. From 24 h on, there was a prolonged terminal phase with a t1/2 of approximately 50 h, and there was only slight dose-dependency during this phase. These data suggest that the pharmacokinetics of cilazapril are nonlinear. A physiologically realistic model based on saturable binding to converting enzyme was developed to account both for the drug kinetics and for the relationship of the kinetics to the dynamics of plasma converting enzyme inhibition. A number of conclusions relevant to the therapeutic application of cilazapril in hypertension are drawn from the data and from the pharmacokinetic-pharmacodynamic model.
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Nussberger J, Fasanella d'Amore T, Porchet M, Waeber B, Brunner DB, Brunner HR, Kler L, Brown AN, Francis RJ. Repeated administration of the converting enzyme inhibitor cilazapril to normal volunteers. J Cardiovasc Pharmacol 1987; 9:39-44. [PMID: 2434792] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cilazapril 1.25 and 5.0 mg p.o. q.d. was administered in double-blind fashion to two groups of six normal volunteers on 8 consecutive days. Blood pressure, heart rate, and plasma converting enzyme activity were measured each day prior to drug administration and up to 72 h after the last dose. Plasma renin activity, blood angiotensin I, plasma angiotensin II, and aldosterone as well as plasma cilazaprilat levels were determined on the first and the last day of active treatment at times 0, 4, and 24 h. The drug was very well tolerated by all volunteers. At 4 h postdrug, plasma converting enzyme activity was reduced in dose-dependent fashion on the first and the eighth day; plasma cilazaprilat levels were also clearly dose dependent. Nevertheless, 24 h postdrug cilazaprilat levels were similar on the first and last day of drug administration, and plasma converting enzyme activity was also stable throughout the 8 days. The various components of the renin-angiotensin system responded in the usual fashion. These results provide strong evidence that cilazapril is a very potent and highly effective converting enzyme inhibitor. Doses well below 5 mg/day will probably suffice for therapeutic efficacy. These data also confirm the hypothesis formulated in the preceding article, i.e., that there is no accumulation of the drug with repeated administration despite its long pharmacological half-life (t1/2).
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Stirpe F, Barbieri L, Abbondanza A, Falasca AI, Brown AN, Sandvig K, Olsnes S, Pihl A. Properties of volkensin, a toxic lectin from Adenia volkensii. J Biol Chem 1985; 260:14589-95. [PMID: 3932357] [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: 01/08/2023] Open
Abstract
Volkensin, a highly toxic protein from the roots of Adenia volkensii (kilyambiti, kinoria), was purified by affinity chromatography on acid-treated Sepharose 6B. The toxin is a glycoprotein (Mr 62,000, neutral sugar content 5.74%) consisting of an A subunit (Mr 29,000) and of a B subunit (Mr 36,000) linked by disulfide and noncovalent bond(s). The amino acid, amino sugar, and neutral sugar composition of the protein were determined. Volkensin is a galactose-specific lectin and is a potent inhibitor of eukaryotic protein synthesis in whole cells as well as in a cell-free system (a rabbit reticulocyte lysate). The inhibitory and the lectin activities are functions of the A and B subunits, respectively. Volkensin can be included amongst the ricin-like toxins and resembles most closely modeccin, the toxin of Adenia digitata.
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Thorpe PE, Brown AN, Bremner JA, Foxwell BM, Stirpe F. An immunotoxin composed of monoclonal anti-Thy 1.1 antibody and a ribosome-inactivating protein from Saponaria officinalis: potent antitumor effects in vitro and in vivo. J Natl Cancer Inst 1985; 75:151-9. [PMID: 3859688] [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: 01/07/2023] Open
Abstract
The ribosome-inactivating protein saporin, from Saponaria officinalis, was coupled by a disulfide bond to monoclonal anti-Thy 1.1 antibody (OX7) and to its F(ab')2 fragment. The immunotoxins were at least as toxic as the plant toxin ricin to the Thy 1.1-expressing cell lines AKR-A and BW5147 in tissue culture. They reduced the rate at which the cells incorporated [3H]leucine into protein by 50% at cell concentrations of 1.5-3 X 10(-11) and 3 X 10(-12) M, respectively. The toxic effect was specific. No toxicity was seen when the immunotoxins were applied to Thy 1.2-expressing EL 4 lymphoma cells at 3 X 10(-8) M, and a control immunotoxin made from an antibody (R10) of irrelevant specificity was without effect on AKA-A cells. Further, the treatment of spleen cells from AKR mice with OX7-saporin at 10(-8) M abolished their response to the T-lymphocyte mitogen concanavalin A, without impairing their response to the B-lymphocyte mitogen lipopolysaccharide. A single iv injection of OX7-saporin into nu/nu randombred mice bearing peritoneal AKR-A lymphoma cells prolonged the survival time of the animals by an extent corresponding to that expected if 99.999% of the tumor cells had been eradicated by the immunotoxin. None of the control materials (unconjugated OX7, unconjugated saporin, OX7 plus saporin, or R10-saporin) delayed tumor growth. The OX7 F(ab')2-saporin conjugate was also highly effective as an antitumor agent, although significantly less so than the conjugate made with intact OX7. Unexpectedly, the acute toxicity of saporin to mice (median lethal dose = 6.8 mg/kg) was elevated eightfold to sixteenfold by conjugation to OX7, R10, or OX7 F(ab')2. Histologic examination of recipients of the immunotoxin revealed gross damage to hepatic parenchymal cells and to the white pulp of the spleen, neither of which was caused by unconjugated saporin. Ricin A-chain coupled to OX7 antibody was one hundredfold to one thousandfold less effective than OX7-saporin as an antitumor agent in vivo, although the two immunotoxins were equally cytotoxic to AKR-A cells in vitro.
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O'Connor PC, Arnold JM, Brown AN, Francis RJ, Finch MB, Galloway DB, Harron DW, McDevitt DG, Shanks RG. Human pharmacokinetic and pharmacodynamic studies on Ro31-1118, a new beta-adrenoceptor antagonist. Br J Clin Pharmacol 1985; 19:319-27. [PMID: 2859047 PMCID: PMC1463730 DOI: 10.1111/j.1365-2125.1985.tb02650.x] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The pharmacokinetic and pharmacodynamic effects of Ro31-1118 were examined in groups of healthy volunteers. In three subjects given 10 mg of [14C]-Ro31-1118 orally, peak levels of radioactivity (84 +/- 5 ng/ml) were 16 times those of the parent drug (approximately 5 ng/ml). Very little parent drug was recovered in the urine, although recovery of total radioactivity was nearly 80% in the urine by day 5. In five subjects studied after both oral and intravenous administration of 20 mg Ro31-1118 the average bioavailability was 57% (range 41-73%). Following intravenous infusion the apparent volume of distribution for the five subjects averaged 590 1 (range 510-700 1). The elimination half-life averaged 18 h (range 17-26 h). In eight subjects who received 40, 80, 160 and 320 mg of Ro31-1118 orally there was a linear relationship between dose and plasma concentration (r = 0.999) and between dose and AUC (r = 0.996). Ro31-1118 had no effect on resting heart rate whereas atenolol reduced resting heart rate up to 6 h after all doses. The maximum reduction of an exercise tachycardia after Ro31-1118 (320 mg) was 23.13 +/- 0.7% and compared with atenolol (100 mg) was 28.2 +/- 1.25%. At 24 h the percentage reduction after Ro31-1118 was 21.5 +/- 1.7%, while after atenolol the percentage inhibition had decreased to 11.1 +/- 1.6%. In three subjects Ro31-1118 (160 mg) orally had no effect on resting heart rate, forearm blood flow and systolic blood pressure, while atenolol (50 mg) reduced all three parameters.(ABSTRACT TRUNCATED AT 250 WORDS)
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Thorpe PE, Detre SI, Foxwell BM, Brown AN, Skilleter DN, Wilson G, Forrester JA, Stirpe F. Modification of the carbohydrate in ricin with metaperiodate-cyanoborohydride mixtures. Effects on toxicity and in vivo distribution. Eur J Biochem 1985; 147:197-206. [PMID: 2982609 DOI: 10.1111/j.1432-1033.1985.tb08737.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Attempts to target antibody-ricin conjugates (immunotoxins) to designated cell types in vivo may be thwarted by their rapid clearance by hepatic reticuloendothelial cells which have receptors that recognise oligosaccharide side chains on the toxin. The B-chain of ricin contains high mannose type oligosaccharides and the A-chain contains a complex unit (GlcNAc)2-Fuc-Xyl-(Man)4-6, all of which potentially could be recognised by the reticuloendothelial system. Treatment of ricin with a mixture of sodium metaperiodate and sodium cyanoborohydride at pH 3.5 resulted in oxidative cleavage of the carbohydrates and reduction of the aldehyde groups thus formed to primary alcohols. By conducting the modification procedure at acidic pH, both the possibility of Schiff's base formation between the aldehyde groups and amino groups in the protein and the possibility of non-specific oxidation of amino acids were minimised. The extent of the carbohydrate modification depended on the duration of treatment, resulting maximally in the destruction of 13 of the 18 mannose residues and of all xylose and fucose. The toxicity of the modified toxin to cells in culture declined by up to 90% as the carbohydrate was destroyed. This was not due to a reduced ability of the B-chain to bind to cells or of the A-chain to inactivate ribosomes. In contrast to the in vitro results, the toxicity of the modified toxin to mice and rats was elevated by up to fourfold. The modification greatly reduced the clearance of the toxin by non-parenchymal cells in the liver and prevented the damage to hepatic Kupffer and sinusoidal cells and to the red pulp of the spleen that is inflicted by the native toxin. The elevated toxicity to animals appears to be because the modified toxin evades the reticuloendothelial system and persists in the bloodstream for longer periods, thus resulting in lethal damage to vital tissues in the animal at lower dosage. The results suggest that immunotoxins prepared from modified ricin would not be readily cleared by the reticuloendothelial system and so be more effective at killing their target cells.
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Thorpe PE, Ross WC, Brown AN, Myers CD, Cumber AJ, Foxwell BM, Forrester JT. Blockade of the galactose-binding sites of ricin by its linkage to antibody. Specific cytotoxic effects of the conjugates. Eur J Biochem 1984; 140:63-71. [PMID: 6608447 DOI: 10.1111/j.1432-1033.1984.tb08067.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.0] [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
A method is described for preparing specific cytotoxic agents by linking intact ricin to antibodies in a manner that produces obstruction of the galactose-binding sites on the B chain of the toxin and so diminishes the capacity of the conjugate to bind non-specifically to cells. The conjugates were synthesised by reacting iodoacetylated ricin with thiolated immunoglobulin and the components of conjugate with reduced galactose-binding capacity were separated by affinity chromatography on Sepharose (a beta-galactosyl matrix) and asialofetuin-Sepharose. Fluorescence-activated cell sorter (FACS) analyses revealed that the fraction of a monoclonal anti-Thy1.1-ricin conjugate that passed through a Sepharose column had markedly diminished capacity to bind non-specifically to Thy1.2-expressing CBA thymocytes and EL4 lymphoma cells. The fraction of conjugate that passed through an asialofetuin-Sepharose column displayed no detectable non-specific binding. Both fractions of conjugate were potent cytotoxic agents for Thy1.1-expressing AKR-A lymphoma cells in tissue culture. They reduced the [3H]leucine incorporation of the cells by 50% at a concentration of 2-5 pM. Comparable inhibition of EL4 cells was only achieved with 3000-7500-fold greater concentrations of conjugate. By contrast, the fraction of anti-Thy1.1-ricin that retained Sepharose-binding capacity showed marked non-specific binding and toxicity to EL4 cells. A conjugate with diminished galactose-binding capacity was also prepared from the W3/25 monoclonal antibody which recognises an antigen upon helper T-lymphocytes in the rat. It elicited powerful and specific toxic effects upon W3/25 antigen-expressing rat T-leukaemia cells. This finding is of particular importance because isolated ricin A-chain disulphide-linked to W3/25 antibody is not cytotoxic. The property of the B-chain in intact ricin conjugates that facilitates delivery of the A-chain to the cytosol thus appears to be independent of galactose recognition. It is concluded that the 'blocked' ricin conjugates combine the advantages of high potency, which is often lacking in antibody-A-chain conjugates, with high specificity, which previously was lacking in intact ricin conjugates.
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Thorpe PE, Mason DW, Brown AN, Simmonds SJ, Ross WC, Cumber AJ, Forrester JA. Selective killing of malignant cells in a leukaemic rat bone marrow using an antibody-ricin conjugate. Nature 1982; 297:594-6. [PMID: 7088145 DOI: 10.1038/297594a0] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Thorpe PE, Brown AN, Ross WC, Cumber AJ, Detre SI, Edwards DC, Davies AJ, Stirpe F. Cytotoxicity acquired by conjugation of an anti-Thy1.1 monoclonal antibody and the ribosome-inactivating protein, gelonin. Eur J Biochem 1981; 116:447-54. [PMID: 6790277 DOI: 10.1111/j.1432-1033.1981.tb05356.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 2.4] [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
Gelonin, a plant protein which can powerfully reduce the protein-synthetic capacity of ribosome preparations, was covalently coupled to anti-Thy1.2 antibody. The conjugate was prepared using N-succinimidyl-3-(2-pyridyldithio)propionate which generates a disulphide linkage between the component molecules. Two conjugate fractions were obtained with Mr of 180 000 and greater than 200 000. After its linkage of the antibody, gelonin suppressed those Thy1.1-bearing T lymphocytes from AKR mice which will respond to phytohaemagglutinin and concanavalin A in tissue culture. The [3H]leucine incorporation with the T-cell mitogens was inhibited by 50% with the 180 000-Mr fraction at a concentration of 0.4 nM and with the greater than 200 000-Mr fraction of pM. Unconjugated gelonin induced comparable reductions in T-cell responsiveness but at concentrations of 30 nM. The conjugates exerted little or no effect upon B lymphocytes or T lymphocytes from CBA mice (Thy1.2 + ve). Thy1.1-expressing AKR lymphoma cell lines, AKR-A and BW5147, were found to be sensitive to the conjugates, albeit much less so than the normal T lymphocytes. The conjugates injected in vivo significantly prolonged the life of CBA mice bearing in an AKR-A lymphoma allograft. It is concluded that gelonin can, by its linkage to an antibody, be rendered cytotoxic with a potency to match or exceed those of the toxins abrin and ricin.
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Abstract
1. The metabolism of debrisoquine sulphate in the dog has been studied and is similar to that in rat and man. 2. Two acidic urinary metabolites, shown to be present in rat, dog and man, have been isolated from rat urine. After derivatization they were characterized by n.m.r. and mass spectroscopy as methyl 2-[2-(4,6-dimethylpyrimidylamino)-methyl]-phenylacetate and 2-[2-(4,6-dimethylpyrimidylamino)-ethyl]benzoate.
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Wyndham CH, Morrison JF, Williams CG, Heyns A, Margo E, Brown AN, Astrup J. The relationship between energy expenditure and performance index in the task of shovelling sand. Ergonomics 1966; 9:371-378. [PMID: 5976535 DOI: 10.1080/00140136608964398] [Citation(s) in RCA: 9] [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: 05/21/2023]
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