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Cundy T, Kanis JA, Fraher L, Clemens TL, O'Riordan JL. The use of metabolites and analogues of vitamin D in prospective renal transplant recipients. Clin Nephrol 1981; 15:240-5. [PMID: 7018772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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77
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Compston JE, Vedi S, Merrett AL, Clemens TL, O'Riordan JL, Woodhead JS. Privational and malabsorption metabolic bone disease: plasma vitamin D metabolite concentrations and their relationship to quantitative bone histology. METABOLIC BONE DISEASE & RELATED RESEARCH 1981; 3:165-70. [PMID: 6897097 DOI: 10.1016/0221-8747(81)90003-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Plasma 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and 25-hydroxyvitamin D (25OHD) concentrations were measured in twenty patients with metabolic bone disease due either to privational causes (10 patients) or malabsorption (10 patients). Abnormally low plasma 1,25(OH)2D3 levels were found in eleven patients, six with privational and five with malabsorption bone disease. Normal plasma 1,25(OH)2D3 concentrations were found in the remaining nine patients; of these, five were either receiving anticonvulsant therapy or had been hospitalised prior to investigation. In the absence of either of these factors, normal plasma 1,25(OH)2D3 levels were only found in patients with malabsorption-associated bone disease. Plasma 25OHD levels were below normal in eleven patients; six had malabsorption and five had privational bone disease. In the fifteen patients not receiving anticonvulsants there were significant inverse correlations between plasma 1,25(OH)2D3 levels and the osteoid volume, surface and seam thickness index. This study indicates that plasma 1,25(OH)2D3 concentrations are low in privational osteomalacia in the absence of anticonvulsant therapy or hospitalisation, although normal levels may occur in malabsorption metabolic bone disease uncomplicated by these factors. The plasma 1,25(OH)2D3 concentration appears to be inversely related to the histological severity of bone disease in patients not receiving anticonvulsant therapy.
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78
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Fraher LJ, Clemens TL, Papapoulos SE, Redel J, O'Riordan JL. Determination of circulating 25,26-dihydroxycholecalciferol in man by radioimmunoassay. Clin Sci (Lond) 1980; 59:257-63. [PMID: 7428293 DOI: 10.1042/cs0590257] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
1. A radioimmunoassay of 25,26-dihydroxycholecalciferol has been developed with an antiserum raised in a sheep, tritiated 1,25-dihydroxycholecalciferol as tracer and synthetic 25,26-dihydroxycholecalciferol as standard. The metabolite was purified from serum extracts by Sephadex LH 20 and high-pressure liquid chromatography; recovery was monitored with biologically generated, tritiated 25,26-dihydroxycholecalciferol. 2. The mean +/- SEM concentration of 25,26-dihydroxycholecalciferol in serum from 18 healthy subjects was 587 +/- 65 pmol/l. Seven Asian patients with osteomalacia due to vitamin D deficiency had very low or undetectable (< 96--231 pmol/l) circulating 25,26-dihydroxycholecalciferol concentrations. 3. The metabolite was detectable in the sera from seven anephric patients (mean 262 +/- 43 pmol/l), indicating that extrarenal sites for the 26-hydroxylation of 25-hydroxycholecalciferol exist in man. 4. A strong positive correlation between the concentrations of 25-hydroxycholecalciferol and those of 25,26-dihydroxycholecalciferol in serum was obtained. Thus it appears that in man the production of this dihydroxy metabolite of vitamin D depends on the concentration of its precursor, 25-hydroxycholecalciferol.
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79
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Papapoulos SE, Clemens TL, Fraher LJ, Gleed J, O'Riordan JL. Metabolites of vitamin D in human vitamin-D deficiency: effect of vitamin D3 or 1,25-dihydroxycholecalciferol. Lancet 1980; 2:612-5. [PMID: 6107407 DOI: 10.1016/s0140-6736(80)90283-4] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Circulating concentrations of hydroxylated metabolites of vitamin D were measured in seven Asian patients with histologically proven osteomalacia before and during treatment with either cholecalciferol (vitamin D3) or 1,25-dihydroxycholecalciferol. All patients showed an excellent clinical and biochemical response to treatment irrespective of type of vitamin D administered. Circulating concentrations of 25-hydroxycholecalciferol and 24,25, 25,26, and 1,25 dihydroxycholecalciferols were abnormally low in the untreated patients. In five patients treated with small doses of cholecalciferol (3000 units, 75 micrograms daily) the concentration of 1,25-dihydroxycholecalciferol rose rapidly to normal and reached supra-normal levels within 72 h. Raised concentrations (up to 200 pg/ml) were sustained for several months and then started falling to normal. Serum 24,25 and 25,26 dihydroxycholecalciferols rose only gradually, after circulating 25-hydroxycholecalciferol concentration had increased to normal. In contrast, in the two patients who received 1,25-dihydroxycholecalciferol (1 microgram daily) serum concentrations of this metabolite rose to normal and only occasionally exceeded the upper limit of normal. The highest concentration observed was 80 pg/ml. Healing of osteomalacia occurred, however, in these two patients in the absence of any measurable increases in 25-hydroxycholecalciferol and 24,25 or 25,26 dihydroxycholecalciferols which all remained abnormally low. Thus, it seems that 1,25-dihydroxycholecalciferol is the most important factor for the healing of vitamin D-deficient osteomalacia and that other hydroxy metabolites are unimportant.
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80
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Pavlovitch H, Clemens TL, Laouari D, O'Riordan JL, Balsan S. Lack of effect on ovariectomy on the metabolism of vitamin D and intestinal calcium-binding protein in female rats. J Endocrinol 1980; 86:419-24. [PMID: 7430901 DOI: 10.1677/joe.0.0860419] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The metabolism of 25-hydroxycholecalciferol (25-(OH)D3), plasma concentration of 1,25-dihydroxycholecalciferol (1,25-(OH)2D3) and the amount of calcium-binding protein (CaBP) in duodenal mucosa were determined in ovariectomized rats and were compared with data observed in normal age-matched cyclic rats. Sephadex LH-20 and high-pressure liquid chromatography were used for the study of the metabolism of 25-(OH)D3. The concentration of 1,25-(OH)2D3 in plasma and prolactin in serum were measured by radioimmunoassay. Calcium-binding protein in duodenal mucosa was determined immunologically using electroimmunodiffusion. The results showed that the lack of ovarian hormones and low prolactin levels observed in ovariectomized rats did not promote a significant change in the metabolism of 25-(OH)D3, in the levels of 1,25-(OH)2D3 in the circulation or in the amount of CaBP in duodenal mucosa. It is possible that the regulation of 25-(OH)D3 by sex hormones is restricted to the state of calcium stress such as during egg-laying in birds or pregnancy and lactation in mammals.
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81
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Liberman UA, Samuel R, Halabe A, Kauli R, Edelstein S, Weisman Y, Papapoulos SE, Clemens TL, Fraher LJ, O'Riordan JL. End-organ resistance to 1,25-dihydroxycholecalciferol. Lancet 1980; 1:504-6. [PMID: 6102232 DOI: 10.1016/s0140-6736(80)92763-4] [Citation(s) in RCA: 108] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A 13-year-old girl with total alopecia who in infancy had rickets unresponsive to large doses of vitamin D2 is described. She had profound hypocalcaemia which was resistant to treatment with high doses of dihydrotachysterol, 1 alpha-hydroxycholecalciferol, and 1,25-dihydroxycholecalciferol. Serum concentrations of 25-hydroxyvitamin D were normal but those of 1,25-dihydroxycholecalciferol were markedly raised (674 and 745 pg/ml). In addition, 24,25-dihydroxyvitamin D was undetectable in serum. Administration of synthetic 24,25-dihydroxycholecalciferol was followed by normocalcaemia which persisted long after treatment was stopped. Her sister, who died at the age of 10 months, also had had total alopecia, rickets, and hypocalcaemia resistant to vitamin-D2 therapy. In this familial syndrome there seems to be end-organ resistance to the action of 1,25-dihydroxycholecalciferol, possibly as a result of changes at the receptor sites.
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82
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Clemens TL, Hill RN, Bullock LP, Johnson WD, Sultatos LG, Vesell ES. Chloroform toxicity in the mouse: role of genetic factors and steroids. Toxicol Appl Pharmacol 1979; 48:117-30. [PMID: 452035 DOI: 10.1016/s0041-008x(79)80014-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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83
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Papapoulos SE, Clemens TL, Fraher LJ, Lewin IG, Sandler LM, O'Riordan JL. 1, 25-dihydroxycholecalciferol in the pathogenesis of the hypercalcaemia of sarcoidosis. Lancet 1979; 1:627-30. [PMID: 85869 DOI: 10.1016/s0140-6736(79)91076-6] [Citation(s) in RCA: 173] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A 36-year-old man with sarcoidosis had four episodes of hypercalcaemia in seven years, all of them during the summer months. Measurement over three years showed that hypercalcaemia was associated with small seasonal increases in serum-25-hydroxycholecalciferol within the normal range. These changes could be mimicked by the administration of 3000 units of vitamin D3 daily. Serum 1, 25-dihydroxycholecalciferol concentrations ranged between 26--62 pg/ml when serum calcium was normal, but were strikingly high, up to 137 pg/ml, when the patient was hypercalcaemic. These studies show for the first time that hypercalcaemia in sarcoidosis is associated with abnormally high circulating concentrations of 1, 25-dihydroxycholecalciferol, probably as a result of overproduction of this, the hormonal form of vitamin D.
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84
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Clemens TL, Hendy GN, Papapoulos SE, Fraher LJ, Care AD, O'Riordan JL. Measurement of 1,25-dihydroxycholecalciferol in man by radioimmunoassay. Clin Endocrinol (Oxf) 1979; 11:225-34. [PMID: 487620 DOI: 10.1111/j.1365-2265.1979.tb03068.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
1 alpha, 25-Dihydroxycholecalciferol (1,25-(OH)2D3) has been measured in human serum by radioimmunoassay. The assay uses a high titre antiserum raised in sheep against 1,25-(OH)2D3-25-hemisuccinate, conjugated to bovine serum albumin. The sensitivity of the assay is 10 pg/tube. Other hydroxylated forms of vitamin D3 cross react with the antiserum and are therefore removed from serum extracts by chromatography on Sephadex LH 20 followed by high pressure liquid chromatography. The mean (+/- SEM) serum 1,25-(OH)2D3 concentration for a group of healthy adult subjects was 41 +/- 2.5 pg/ml. None was detected in anephric patients and the concentration was low or undetectable in patients with chronic renal failure.
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85
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Clemens TL, Hendy GN, Graham RF, Baggiolini EG, Uskokovic MR, O'Riordan JL. Production of antibodies to 1alpha,25-dihydroxycholecalciferol-25-hemisuccinate: development of a sensitive radioimmunoassay for 1alpha,25-dihydroxycholecalciferol [proceedings]. J Endocrinol 1978; 77:49P-50P. [PMID: 660067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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86
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Clemens TL, Hendy GN, Graham RF, Baggiolini EG, Uskokovic MR, O'Riordan JL. A radioimmunoassay for 1,25-dihydroxycholecalciferol. CLINICAL SCIENCE AND MOLECULAR MEDICINE 1978; 54:329-32. [PMID: 630809 DOI: 10.1042/cs0540329] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
1. 1alpha,25-Dihydroxy-25-hemisuccinate cholecalciferol has been synthesized and conjugated to bovine serum albumin. 2. This conjugate is immunogenic; when injected into rabbits antibodies of high affinity for 1alpha,25-dihydroxycholecalciferol were obtained. 3. Vitamin D metabolites lacking the 1alpha-hydroxy group were of lower cross-reactivity with the antibodies. 4. By using these antibodies and 1alpha,25-[23,24-3H]dihydroxycholecalciferol as tracer a sensitive radioimmunoassay has been developed capable of detecting 20 pg of 1alpha,25-dihydroxycholecalciferol.
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87
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Vesell ES, Lang CM, White WJ, Passananti GT, Hill RN, Clemens TL, Liu DK, Johnson WD. Environmental and genetic factors affecting the response of laboratory animals to drugs. FEDERATION PROCEEDINGS 1976; 35:1125-32. [PMID: 1261707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Only some of the diverse factors that can affect drug disposition and response in laboratory animals have been identified at the present time. These numerous factors contribute to large day-to-day variations that have become a major problem impeding investigation of drug disposition and response in laboratory animals. Although these variations render many experiments difficult to interpret and produce large discrepancies in the literature, few published investigations using laboratory animals provide sufficient details to permit replication of the studies under similar conditions with respect to these variables. Thus, the importance of these variables in affecting results is apparently insufficiently recognized at present. Two commonly overlooked variables affecting the activity of hepatic microsomal enzymes (HME) in rodents and hence the rate at which rodents eliminate from their bodies many foreign compounds are the bedding under the wire mesh cage and the relative cleanliness of the environment. Numerous chemicals present in relatively low concentrations in the environment of the animal room can significantly alter HME activity. Representative of these chemicals are aromatic hydrocarbons in cedarwood bedding, eucalyptol from aerosol sprays, and chlorinated hydrocarbon insecticides, each of which induces HME activity, whereas ammonia generated from feces and urine accumulated in unchanged pans under cages may inhibit HME activity. Chloroform, identified as an environmental contaminant of the water and air of certain cities, exhibits sex and strain differences with respect to toxicity (LD50) in mice. After intraperitoneal injection, twice as much chloroform accumulated in the kidneys of males from the sensitive strain (DBA/2J) as from the resistant (C57BL/6J) strain. First generation offspring were midway between parental strains both with respect to LD50 and renal accumulation of chloroform.
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Hill RN, Clemens TL, Liu DK, Vesell ES, Johnson WD. Genetic control of chloroform toxicity in mice. Science 1975; 190:159-61. [PMID: 1166306 DOI: 10.1126/science.1166306] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Mouse strain differences suggest intermediate or multifactorial gentic control of chloroform-induced renal toxicity and death. The chloroform dose lethal to 50 percent of animals was four times higher in C57BL/6J males than in DBA/2J males. Twice as much chloroform accumulated in the kidneys of the sensitive as the resistant strain. First generation offspring were midway between parental strains for both parameters.
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Clemens TL, Selesnick ST. Psychological method for evaluating medication by repeated exposure to a stressor film. DISEASES OF THE NERVOUS SYSTEM 1967; 28:98-104. [PMID: 6021594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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90
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Sterman MB, Clemens TL, Wenger MA. AUTONOMIC AND CLINICAL CORRELATES OF DIFFERENTIAL ELECTROENCEPHALOGRAM RESPONSE TO COLD PRESSOR STIMULATION. Psychophysiology 1966. [DOI: 10.1111/j.1469-8986.1966.tb02662.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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91
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