PubMed Health⌕ Search

Biomedical subjects

D Denis

Publications and source records attributed to D Denis.

At least 91 records · Page 5Linked to original sources

Biological and clinical assessment of a new bisphosphonate, (chloro-4 phenyl) thiomethylene bisphosphonate, in the treatment of Paget's disease of bone.

Several Biophosphonates have been used as therapeutic agents for Paget's bone disease. (Chloro-4 phenyl)thiomethylene-bisphosphonate (CIPsMBP) has recently been shown to have significant antiosteoclastic activity while an affect of CIPsMBP on mineralization was only observed at high doses. We tested this drug for 6 months in 23 pagetic patients distributed in three groups. Gr 1 (n = 5) receiving 200 mg/day showed a decrease of serum alkaline phosphatase (SAP) to 42 +/- 4% (p less than 0.01) of initial value (100%) while hydroxyprolinuria/creatinuria ratio (OH/Cr) dropped to 69 +/- 8% of baseline. In 4 patients receiving 400 mg/day, SAP improved to 48 +/- 9% of initial value (p less than 0.01) and OH/Cr to 40 +/- 3% (p less than 0.01). In the last group (n = 14) receiving 200 mg/day for 3 months, and 400 mg/day thereafter up to the 6th month SAP decreased to 53 +/- 4% and OH/Cr to 62 +/- 6% of initial value (p less than 0.01). Clinical improvement was significant from the first month of treatment. No resistance (mean decrease of SAP lower than 30%) was recorded and no radiological or clinical evidence of mineralization defect appeared. The clinical and biological tolerance was excellent throughout the study.

Aged↗

Antigen-induced contraction of guinea-pig isolated trachea: studies with novel inhibitors and antagonists of arachidonic acid metabolites.

1. Responses of antigen-challenged isolated trachea from sensitized guinea-pigs were pharmacologically characterized by use of some novel inhibitors and antagonists of arachidonic acid metabolites. 2. The cyclo-oxygenase inhibitor, indomethacin, prolonged without altering the maximum response to antigen in the absence of the anti-muscarinic agent, atropine, and/or the H1-receptor blocker, mepyramine. In the presence of mepyramine, indomethacin both prolonged and increased the magnitude of the response. The selective (SQ-29548) and non-selective (L-640,035) thromboxane A2 (TXA2) antagonist and the TXA2 synthetase inhibitor, OKY-046, were essentially inactive. 3. Two novel inhibitors of 5-lipoxygenase product formation, AA-861 and L-651,896 produced complete inhibition of the response to antigen on tissues treated with atropine and mepyramine, with or without indomethacin. 4. Equimolar concentrations of the leukotriene D4 (LTD4) receptor antagonists LY-171883 greater than L-649,923 greater than or equal to L-648,051 greater than or equal to FPL-55712 blocked part of the response to antigen on tissues treated with atropine, mepyramine and indomethacin. All compounds tended to block a larger component of the response in the absence of indomethacin. A similar tendency was observed with the potent phosphodiesterase inhibitor, isobutylmethylxanthine (IBMX) but not the less potent phosphodiesterase inhibitor theophylline. 5. These results are consistent with the hypothesis that 5-lipoxygenase products acting on LTD4 receptors play only a minor role in the mediation of the contraction of guinea-pig trachea to antigen challenge. The nature of the residual contractile mediator is unknown; however, it can be completely blocked by the 5-lipoxygenase inhibitors AA-861 and L-651,896 and non-selectively blocked by the phosphodiesterase inhibitor, IBMX and non-selective LTD4 receptor antagonists, such as LY-171883.

1-Methyl-3-isobutylxanthine↗

Leukotriene and anti-IgE induced contractions of human isolated trachea: studies with leukotriene receptor antagonists and a novel 5-lipoxygenase inhibitor.

The pharmacological actions of three leukotriene D4 (LTD4) receptor antagonists, FPL-55712, L-648,051, and L-649,923, and a novel inhibitor of leukotriene biosynthesis, L-651,896, have been investigated on isolated human tracheal smooth muscle. In the order of potency L-648,051 greater than FPL-55712 greater than L-649,923, these agents antagonized contractions to LTD4 and produced parallel rightward shifts in the dose-response curves. Mean -log KB values against LTD4 were 6.9 +/- 0.1, 6.5 +/- 0.3, and 6.0 +/- 0.1 for L-648,051, FPL-55712, and L-649,923, respectively. FPL-55712 also antagonized contractions to LTC4 (-log KB value, 6.4 +/- 0.3) and this activity was not decreased by the gamma-glutamyl transpeptidase inhibitor, L-serine borate. In the presence of 1 x 10(-7) M atropine, 7 x 10(-6) M mepyramine, and 1.4 x 10(-6) M indomethacin, L-648,051 at 2 x 10(-5) and 2 x 10(-6) M produced complete and partial blockade, respectively, of the contraction to goat anti-IgE. L-649,923 and FPL-55712 produced partial but significant inhibition at 2 x 10(-5) M, whereas the 5-lipoxygenase inhibitor, L-651,896, produced almost complete inhibition at 3.5 and 35 x 10(-6) M. L-Serine borate (15 mM) did not alter the the activity of FPL-55712 versus anti-IgE. These findings indicate that LTD4 receptors mediate contraction of human trachea to exogenously applied and endogenously (anti-IgE) released leukotrienes. LTD4 antagonists, such as L-648,051, may be useful in assessing the role of leukotrienes in respiratory disease.

Animals↗

Community health effects of a municipal water supply hyperfluoridation accident.

For 12 hours, excess hydrofluorosilicic acid was diverted to a 127-home community water supply. Fluoride levels peaked at 51 parts per million (ppm). Water acidification caused copper to leach from the domestic plumbing; raising copper levels to 25-41 ppm. Fifty-two (33 per cent) of those who drank hyperfluoridated water developed mild gastroenteritis. Vomiting was uncommon and symptom onsets usually occurred greater than 30 minutes after drinking water; suggesting that fluoride, rather than copper, caused illness. Skin contact with hyperfluoridated water caused itching and skin rashes.

Accidents, Occupational↗

[Treatment of a case of retinal detachment in morning glory syndrome].

The association of Morning glory syndrome and retinal detachment has been described several times. The observation of one clinical case has led us to review all the proposed physiopathogenic hypotheses and to deduce an original therapeutic attitude. The possibility of an abnormal communication between the sub retinal and sub arachnoidal spaces has justified the use of acetazolamide to reduce the secretion of spinal fluid and the prevention of its subretinal diffusion by an ocular compression. The reapplication which has been obtained was followed by a wide spread retinopexy on the detached retina. In addition, an intravitreous injection of C3F8 has been used to treat of a retinal hole in the staphylomatous area.

Female↗

1-Year controlled randomised trial of prevention of early postmenopausal bone loss by intranasal calcitonin.

79 women who had been menopausal for less than 36 months and who had not received any form of treatment to prevent bone loss were randomly assigned to a 12-month regimen of calcium 500 mg/day or calcium 500 mg plus intranasal salmon calcitonin 50 IU/day for 5 days per week. After 12 months of treatment bone mineral density had decreased in the calcium-only group by a mean of 3.16 (SEM 0.6)% (p less than 0.01) but had increased in the calcium plus calcitonin group by 1.38 (0.8)% (NS). The difference in response between the two treatment groups was also highly significant (p less than 0.01), as was the difference between values for hydroxyprolinuria/creatininuria (p less than 0.01). Endogenous calcitonin levels rose significantly in the calcium group but remained unchanged in calcitonin-treated patients. Treatment by calcitonin and calcium was not followed by increased secretion of parathyroid hormone. The findings suggest that intranasal calcitonin can counteract early postmenopausal bone loss.

Administration, Intranasal↗

Assessment of the biological effectiveness of nasal synthetic salmon calcitonin (SSCT) by comparison with intramuscular (i.m.) or placebo injection in normal subjects.

For patients who require treatment over a period of some years, intranasal administration of synthetic salmon calcitonin (SSCT) obviates the discomfort associated with administration by injection. Moreover, this mode of administration is not associated with the side effects normally encountered when calcitonin is injected intramuscularly or subcutaneously. The aim of this study was to assess, in normal subjects, the biological activity of nasal SSCT by comparing the fluctuations of parameters reflecting calcium-phosphorus metabolism after nasal instillation, injection of SSCT and injection of placebo, respectively. In nine healthy subjects, this instillation of 200 IU of SSCT into the nasal cavity caused a fall in serum calcium, a fall in serum phosphorus and a transient rise in parathyroid hormone levels similar to that observed after the intramuscular (i.m.) injection of 80 IU of SSCT. SSCT whether administered by the nasal route or by injection, does not inhibit endogenous calcitonin secretion. There were no changes in serum beta-endorphin, magnesium or erythrocyte magnesium levels after administration of calcitonin by the intranasal route or by injection.

Administration, Intranasal↗

L-649,923, sodium (beta S*, gamma R*)-4-(3-(4-acetyl-3-hydroxy-2-propylphenoxy)-propylthio)- gamma-hydroxy-beta-methylbenzenebutanoate, a selective, orally active leukotriene receptor antagonist.

L-649,923, Sodium (beta S*, gamma R*)-4-(3-(4-acetyl-3-hydroxy-2-propylphenoxy)propylthio)- gamma- hydroxy-beta-methylbenzenebutanoate is a selective and competitive inhibitor of [3H]leukotriene D4 (Ki value of 400 nM) and to a lesser extent [3H]leukotriene C4 (Ki value of 8.6 microM) binding in guinea-pig lung homogenates. Functionally, it selectively antagonized contractions of guinea pig trachea induced by leukotriene C4, D4, E4, and F4 but not those induced by acetylcholine, histamine, serotonin, prostaglandin F2 alpha, or U-44069 (stable endoperoxide analogue). Schild plot analysis indicated a competitive inhibition of contractions of guinea-pig ileum induced by leukotriene D4 (pA2 8.1) and contractions of guinea-pig trachea induced by leukotrienes E4 and F4 (pA2 7.1 and 6.9, respectively). In contrast, contractions of guinea-pig trachea induced by leukotrienes C4 (pA2 7.2; slope 0.6) and D4 (pA2 7.2; slope 0.7) were inhibited in a noncompetitive fashion. In vivo, intravenously administered L-649,923 selectively blocked bronchoconstriction induced in anesthetized guinea pigs by leukotriene C4 and D4 (ED50 values i.v. 0.38 and 0.26 mg/kg, respectively) but not that induced by histamine, arachidonic acid, serotonin, U-44069, or acetylcholine. Following intraduodenal administration, L-649,923, blocked leukotriene D4 induced bronchoconstriction (5 and 10 mg/kg). The present findings indicate that selective antagonists, such as L-649,923, may be useful for defining the role of leukotrienes in diseases such as bronchial asthma.

Airway Resistance↗

L-648,051, sodium 4-[3-(4-acetyl-3-hydroxy-2-propylphenoxy)- propylsulfonyl]-gamma-oxo-benzenebutanoate: a leukotriene D4 receptor antagonist.

L-648,051, sodium 4-[3-(4-acetyl-3-hydroxy-2-propylphenoxy) propylsulfonyl]-gamma-oxo-benzenebutanoate is a selective and competitive inhibitor of [3H]leukotriene D4 (KB value of 4.0 microM) and to a lesser extent [3H]leukotriene C4 (Ki value of 36.7 microM) binding in guinea pig lung homogenates. Functionally, it selectively antagonized contractions of guinea pig trachea induced by leukotrienes C4, D4, E4, and F4 in concentrations that did not antagonize contractions induced by acetylcholine, histamine, serotonin, prostaglandin F2 alpha, or U-44069 (endoperoxide analogue). Schild plot analysis indicated that L-648,051 competitively antagonized contractions of guinea pig ileum induced by leukotriene D4 (pA2 7.7) and contractions of trachea induced by leukotrienes D4, E4, and F4 (pA2 7.3, 7.4, and 7.5, respectively). Contractions of guinea pig trachea induced by leukotriene C4 were inhibited in a noncompetitive fashion (Schild plot slope, 0.45). Developed contractions of trachea induced by the leukotrienes were rapidly reversed by L-648,051 greater than FPL-55712 greater than L-649,923. Intravenous L-648,051 selectively blocked bronchoconstriction induced in anaesthetized guinea pigs by intravenous leukotrienes C4, D4, and E4 but not that induced by arachidonic acid, serotonin, U-44069, or acetylcholine. The compound displayed poor activity following intraduodenal administration. The profile of activity for L-648,051 indicates that it may be a useful topical agent for studying the role of leukotrienes in diseases such as bronchial asthma.

Animals↗

Study of mechanisms mediating contraction to leukotriene C4, D4 and other bronchoconstrictors on guinea pig trachea.

Contractions of guinea pig trachea in the absence and presence of indomethacin to LTD4 greater than LTC4 greater than K+ greater than histamine greater than acetylcholine were reduced following a 45 minute exposure of the tissues to calcium-free Krebs' solution (Ca2+-free Krebs' solution), were further reduced by a transient exposure to EGTA (1.25 mM) in Ca2+-free Krebs' solution and were virtually abolished when tested in the presence of EGTA (0.125 mM) in Ca2+-free Krebs' solution. In normal Krebs' solution (2.5 mM Ca2+) the Ca2+ entry blockers nifedipine (N) much greater than D-600 greater than verapamil (V) greater than diltiazem (D) almost completely abolished the contractions to K+ but blocked only a component of the maximum response to the other agonists. After exposure to Ca2+-free Krebs' solution for 45 minutes, any residual contractions to LTC4 & LTD4, were reversed by low concentrations of N (0.3 microM) or D-600 (2.1 microM). Leukotrienes appear to mobilize a superficial and a bound store of Ca2+ which gains entry through at least two types of Ca2+ channels (or mechanisms), one of which is blocked by N and D600. K+-induced contractions appear to be dependent on superficial and tightly bound Ca2+ but entry is solely through channels which are blocked by the Ca2+ entry blockers studied. Contraction to histamine and acetylcholine persisted following exposure of the tissues to Ca2+ free Krebs' solution but contractile activity was virtually abolished in Ca2+ free Krebs' solution containing EGTA. Residual contractions to histamine and part of the residual contractions to acetylcholine in Ca2+-free Krebs' solution were blocked by low dose N (0.3 microM) or D600 (2.1 microM). These findings suggest a major role for extracellular Ca2+ during spasmogen-induced contraction in this tissue.

Acetylcholine↗

Pharmacological study of the effects of leukotrienes C4, D4, E4 & F4 on guinea pig trachealis: interaction with FPL-55712.

Leukotrienes D4 greater than C4 greater than E4 greater than F4 produced qualitatively similar contractions of guinea-pig trachealis, which were antagonized by the SRS-antagonist FPL-55712. Schild analyses indicated that FPL-55712 when tested in a low concentration range (0.57 - 5.7 X 10(-6) M) was a competitive antagonist of LTC4, LTE4 and LTF4 (slope not significantly different from one). The interaction of FPL-55712 with LTD4 may be noncompetitive (slope less than 1). Comparison of the calculated dissociation constants (-log KB) indicated that FPL-55712 was more effective at blocking LTE4 and LTF4 compared to LTC4 and LTD4. In the presence of higher concentrations of FPL-55712 (1.9 X 10(-5) M) the antagonism of LTC4 became noncompetitive. These findings indicate that important differences exist in the interaction of FPL-55712 with the various peptido leukotrienes in guinea pig trachealis. Discovery of more selective antagonists will be needed to determine if multiple receptor subtypes are present in this tissue.

Animals↗