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Laurent EMN, Ducrocq C, Cren PY, Boutaa K, Crie D, Penel N. Why do second-cycle medical students choose oncology? A literature overview. Bull Cancer 2024; 111:505-512. [PMID: 38553287 DOI: 10.1016/j.bulcan.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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] [Received: 12/04/2023] [Revised: 01/24/2024] [Accepted: 02/01/2024] [Indexed: 05/13/2024]
Abstract
INTRODUCTION Given the current global cancer epidemic across the world, the need for healthcare professionals in this field is crucial. Little is known about the factors that drive medical students toward oncology. METHOD We conducted a systematic review of the literature (from 1980 to the present), using several search equations and selecting original articles written in English based on qualitative or quantitative surveys, to understand what motivates medical students to choose oncology. RESULTS We identified only seven articles that reported quantitative surveys; no qualitative surveys were found. These seven surveys are composed of closed-ended questions and are pragmatic questionnaires based on field knowledge, but without an underlying theory. These studies most often interrogate students already oriented towards oncology. The following five concepts associated with the choice of oncology had the highest recurrence among these seven surveys, which had been conducted in different countries and at various times: interest in cancer management, initiation of the specialty during the 2nd cycle, job opportunities, low working hours, and quality of life. DISCUSSION The literature on this topic is particularly scarce. No qualitative studies have been published in the English language. The limited data in the literature do not allow us to fully comprehend the problem.
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Affiliation(s)
- Estelle M N Laurent
- Lille University, University School of Management (IAE), ULR 4999, Lille University Management Lab., Lille, France
| | - Christophe Ducrocq
- CIREL - Education and Training Sciences, Interuniversity Center for Research in Education of Lille, Faculty of Psychology, Lille University, Villeneuve d'Ascq, France
| | - Pierre-Yves Cren
- Department of Medical Oncology, Centre Oscar-Lambret, Lille, France; ULR 2694 - Metrics: Evaluation des technologies de santé et des pratiques médicales, CHU of Lille, University of Lille, Lille, France
| | - Khaled Boutaa
- Lille University, University School of Management (IAE), ULR 4999, Lille University Management Lab., Lille, France
| | - Dominique Crie
- Lille University, University School of Management (IAE), ULR 4999, Lille University Management Lab., Lille, France
| | - Nicolas Penel
- Lille University, University School of Management (IAE), ULR 4999, Lille University Management Lab., Lille, France; Department of Medical Oncology, Centre Oscar-Lambret, Lille, France; ULR 2694 - Metrics: Evaluation des technologies de santé et des pratiques médicales, CHU of Lille, University of Lille, Lille, France.
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Penel N, Mailliez A, Pannier D, Ducrocq C. [Should we take into account the informational stress of the medical oncologist?]. Bull Cancer 2024; 111:222-227. [PMID: 38199834 DOI: 10.1016/j.bulcan.2023.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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] [Received: 11/09/2023] [Accepted: 11/17/2023] [Indexed: 01/12/2024]
Abstract
Information overload, informational stress and its deleterious consequences constitute a subject of growing interest in the way of work. This is quite well documented among anesthesiologists. Studies have also been carried out on cancer patients or on the general public in terms of cancer prevention. After having defined the concepts and the consequences, we hypothesize the presence of informational stress among medical oncologists. We illustrate this hypothesis regarding adjuvant treatment of breast cancer. Specific studies (qualitative and quantitative ones) would be particularly interesting in oncology.
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Affiliation(s)
- Nicolas Penel
- Department of Medical Oncology, Centre Oscar-Lambret, Lille, France; ULR 2694 - Metrics : évaluation des technologies de santé et des pratiques médicales, CHU de Lille, University of Lille, Lille, France.
| | - Audrey Mailliez
- Department of Medical Oncology, Centre Oscar-Lambret, Lille, France
| | - Diane Pannier
- Department of Medical Oncology, Centre Oscar-Lambret, Lille, France
| | - Christophe Ducrocq
- Faculty of Psychology, CIREL - Education and Training Sciences, Interuniversity Center for Research in Education of Lille, Lille University, Villeneuve d'Ascq, France
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Ducrocq C, Chaton V, Wallaert B, Rémy-Jardin M. Une pneumopathie interstitielle particulière. Rev Mal Respir 2019; 36:369-371. [DOI: 10.1016/j.rmr.2019.01.006] [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] [Received: 10/16/2018] [Accepted: 01/03/2019] [Indexed: 10/27/2022]
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Abstract
Melatonin (N-acetyl-5-methoxytryptamin), the main hormone secreted by the pineal gland in mammals, is nitrosated by nitrite at acidic pH and by NO in the presence of oxygen under neutral conditions. Melatonin is also partly converted to 1-nitrosomelatonin by oxoperoxonitrate (ONOO-, peroxynitrite) in phosphate-buffered solutions at pH 7-10 [Blanchard, B., et al. (2000) Journal of Pineal Research 29, 184-192]. In the present report, we show that 1-nitrosomelatonin in turn behaves as an NO-donor regenerating melatonin. NO-release is evidenced by the formation of nitrite in phosphate-buffered solutions and oxidation of HbO2. No peroxynitrite was formed during that decomposition because serotonin used as a probe was converted only to 4-nitroso-serotonin as expected for a true NO-donor [Blanchard, B., et al. (2001) Free Radical Research, 34, 177-188]. The spontaneous decay of 1-nitrosomelatonin is not affected by GSH and metallic ions but its decomposition is accelerated in acidic pH or in the presence of NADH or ascorbate. Furthermore, melatonin is partially or entirely recovered in the absence or presence of ascorbate, respectively. A homolytic cleavage of 1-nitrosomelatonin is strongly suggested and discussed. Formation of 1-nitrosomelatonin from melatonin and reactive nitrogen species (RNS) followed by its decay into NO demonstrates that melatonin could reduce these RNS to NO.
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Affiliation(s)
- B Blanchard-Fillion
- Institut de Chimie des Substances Naturelles, CNRS SCUPR 2301, Gif-sur-Yvette, France
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Guermonprez L, Ducrocq C, Gaudry-Talarmain YM. Inhibition of acetylcholine synthesis and tyrosine nitration induced by peroxynitrite are differentially prevented by antioxidants. Mol Pharmacol 2001; 60:838-46. [PMID: 11562447] [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: 02/21/2023] Open
Abstract
Evidence of an overload of reactive oxygen species and peroxynitrite, a derivative of nitric oxide, in sporadic amyotrophic lateral sclerosis suggests that peroxynitrite could impair cholinergic functions. Because of the impossibility of obtaining synaptosomes from vertebrate neuromuscular junctions, we used cholinergic synaptosomes purified from Torpedo marmorata electroneurons to characterize the defects triggered by peroxynitrite in more detail. Addition of peroxynitrite or its donor 3-morpholinosydnonimine abolished high-affinity choline uptake and synthesis of acetylcholine from acetate. T. marmorata choline acetyltransferase (ChAT) was impaired to the same extent as bovine brain ChAT. A hallmark of peroxynitrite action is the nitration of tyrosine residues in proteins. Peroxynitrite induced a concentration-dependent appearance of nitrotyrosines in several neuronal proteins from synaptosomes and, more readily, from synaptic vesicles. Peroxynitrite also triggered tyrosine nitrations in purified ChAT. Peroxynitrite-dependent nitrations were impaired when synaptosomes were pretreated with thioreductants (glutathione, N-acetyl cysteine, dithiothreitol) or antioxidants (uric acid, melatonin, bovine serum albumin, desferrioxamine). Deleterious effects of peroxynitrite on choline transport and ChAT activity were prevented by the thioreductants but only partially by the antioxidants, suggesting a mechanism other than tyrosine nitration, which may involve cysteine oxidation. Further development of protective agents acting on choline transport and on ChAT activity may offer interesting therapeutic possibilities with respect to cholinergic dysfunction occurring in neurodegenerative diseases.
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Affiliation(s)
- L Guermonprez
- Laboratoire de Neurobiologie Cellulaire et Moléculaire, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France
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6
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Abstract
The aim of this work was to assess the capacities of some .NO-donors to release .NO, and consequently NOx in aerobic medium, or to give peroxynitrite. The method was based on the differential reactivity of serotonin (5-HT) with either NO(x) or peroxynitrite, leading in phosphate-buffered solutions to 4-nitroso- and 4-nitro-5-HT formation, respectively. Yields and formation rates of 5-HT derivatives with .NO-donor were compared to those obtained with authentic .NO or peroxynitrite in similar conditions. Aside from the capacity of diazenium diolates (SPER/NO and DEA/NO) to release .NO spontaneously, converting 5-HT exclusively to 4-nitroso-5-HT, all other .NO donors must undergo redox reactions to produce .NO. S-nitrosoglutathione (GSNO) and sodium nitroprusside (SNP) modified 5-HT only in the presence of Cu2+, GSNO yielding 6 times more 4-nitroso-5-HT than SNP. Furthermore, in the presence of Cu+, the yield of .NO-release from GSNO was 45%. The molsidomine metabolite (SIN-1), which was presumed to release both .NO and O2(7-) at pH 7.4, reacted with 5-HT differently, depending on the presence of reductant or oxidant. Under aerobic conditions, SIN-1 acted predominantly as a 5-HT oxidant and also as a poor .NO and peroxynitrite donor (15% yield of .NO-release and 14 % yield of peroxynitrite formation). The strong oxidant Cu2+, even in the presence of air oxygen, accelerated oxidation and increased .NO release from SIN-1 up to 86%. Only a small part of SIN-1 gave simultaneously .NO and O2(7-) able to link together to give peroxynitrite, but other oxidants could enhance .NO release from SIN-1.
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Affiliation(s)
- B Blanchard
- Institut de Chimie des Substances Naturelles, C.N.R.S., Avenue de la Terrasse, F-91198 Gif sur Yvette (France)
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Ducrocq C, Servy C, Cudic M, Blanchard EB. [Intervention by nitric oxide, NO, and its oxide derivatives particularly in mammals]. Can J Physiol Pharmacol 2001; 79:95-102. [PMID: 11235675] [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: 02/19/2023]
Abstract
Nitric oxide (NO) is a natural and stable free radical produced in soil and water by the bacteriological reduction of nitrites and nitrates and in animals by the enzyme oxidation of L-arginine. NO is biosynthesised by finely regulated enzymatic systems called NO-synthases and readily diffuses through tissues. It reacts rapidly with hemoproteins and iron-sulphur centers to form nitrosylated compounds. It oxidises more slowly to form nitrogen oxides that nitrosate thiols into thionitrite. NO is transported in these various forms and released spontaneously or through yet unclear mechanisms into most cells; it also regulates oxygen consumption at the mitochondrial respiratory chain level through interaction with cytochrome oxidase. In the cardiovascular system, NO lowers blood pressure by activating a hemoprotein, the guanylate cyclase present in muscle cells; through such interaction it acts also as a neuromediator and neuromodulator in the nervous system. However, many of NO's roles result from rapid coupling to other radicals; for example, it reacts with the superoxide anion (O2-) to form oxoperoxinitrate (ONOO-, also known as peroxynitrite). This strong oxidant of metallic centers, thiols, and antioxidants is also able to convert tyrosine to 3-nitrotyrosine and to act upon tyrosine residues contained in proteins. The biological aspects of the roles of NO are presented with particular respect to the rapid interactions of NO with hemoproteins' iron and other radicals. Concurrently, NO oxidation enables nitrosation reactions primarily of thiols but ultimately of nucleic bases. The thionitrite function (R-S-NO) thus formed and the dimerisation and nitration of tyrosine residues are protein post-translational modifications that are being investigated in animals.
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Affiliation(s)
- C Ducrocq
- Institut de Chimie des Substances Naturelles, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.
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8
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Abstract
Peroxynitrite (ONOO-) is an endogenous molecule, formed by rapid coupling between *NO and O2*-. ONOO- is known to be a strong oxidant of thiols and metalloorganic compounds and also a nitrating agent of aromatic compounds such as tyrosine. However, its chemistry is not yet well elucidated under physiological conditions. Melatonin, which is an indole-amine produced by the pineal gland and other organs, has antioxidant properties. We show that melatonin reacts with ONOO- in phosphate-buffered solutions. We provide evidence of nitrosation and oxidation at the pyrrole nitrogen leading to 1-nitrosomelatonin and 1-hydroxymelatonin, these being the major reactions in aqueous phosphate-buffered solutions besides other aromatic hydroxylations and nitration. 4-Nitromelatonin is formed, but in small amounts. The kinetics of all transformations were strictly dependent on ONOO- decay, whereas yields varied with pH and the presence of CO2. The N-oxidation became competitive with nitrosation at pH 7.4, in medium containing a sufficient amount of CO2. A proposed mechanism involves the transient formation of melatonyl radical and ONOO* radical derived from ONOO- decay.
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Affiliation(s)
- B Blanchard
- Institut de Chimie des Substances Naturelles, CNRS, Gif-sur-Yvette, France
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9
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Blanchard B, Dendane M, Gallard JF, Houée-Levin C, Karim A, Payen D, Launay JM, Ducrocq C. Oxidation, nitrosation, and nitration of serotonin by nitric oxide-derived nitrogen oxides: biological implications in the rat vascular system. Nitric Oxide 2000; 1:442-52. [PMID: 9466949 DOI: 10.1006/niox.1997.0147] [Citation(s) in RCA: 28] [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: 02/06/2023]
Abstract
Because NO is not very reactive in an oxygen-free buffer, a significant part of serotonin (5-HT) is transformed by NO in nondeaerated phosphate buffer, at pH 7.4, into (4-serotonyl)-4-serotonin, 4-nitrososerotonin, and 4-nitroserotonin. Dimerization and above all nitrosation occur through the HNO2 reaction in the pH 4-6 range, possibly via radical mechanism involving N2O3. 5-HT is readily a substrate for nitrosation by HNO2 or N2O3, whereas tyrosine was described as not very reactive under the same conditions. Peroxynitrite converts 5-HT to the (4-serotonyl)-4-serotonin and to the 4-nitro derivative. In order to evaluate whether such structural modifications could modulate the biological properties of 5-HT, arterial pressure was measured after i.v. bolus injection of these derivatives to anesthetized rats. Injections of the 4-nitroso- and 4-nitro-5-HT resulted in first a brief hypotensive response and did not give the subsequent hypertensive and hypotensive phases observed with 5-HT. Finally, when tested on some cloned rat 5-HT receptors stably transfected into LMTK- cells, both 4-nitroso and 4-nitro derivatives behaved as agonists and antagonists toward 5-HT1B and 5-HT2B receptors, respectively.
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Affiliation(s)
- B Blanchard
- Institut de Chimie des Substances Naturelles, CNRS, Gif sur Yvette, France
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10
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Abstract
To investigate the protective effect of the anesthetic 2, 6-diisopropylphenol, or propofol, in oxidative processes in which (*)NO and peroxynitrite are involved, direct interactions were explored. The reactions of the highly lipophilic propofol with (*)NO in methanolic or aqueous buffered solutions under air were shown to produce the same compounds as those detected with peroxynitrite, but with very low yields and slow rates. In aqueous neutral medium, peroxynitrite (ONOO(-), ONOOCO(-)(2), ONOOH) was able to nitrate and oxidize propofol: In addition to oxidation products, quinone and quinone dimer, the formation of the 4-nitropropofol derivative was detected, increasing with peroxynitrite or CO(2) concentrations. Nitration reached 20% after the addition of 25 mM bicarbonate to an equimolecular mixture of peroxynitrite and propofol in methanol/phosphate-buffered solution (1/4,v/v) at pH 7.4. However, peroxynitrite either in methanol or in alkaline-buffered mixture (optimum pH 10-12) resulted in the rapid and almost complete transformation of propofol to an intermediate compound 1, which further decomposed to 4-nitrosopropofol. The transient compound 1 was obtained from either peroxynitrite or (*)NO in the presence of oxygen. From mass spectrometry determination of compound 1 we propose the involvement of the nitrosodioxyl radical ONOO(*), forming an adduct with the propofoxyl radical, to yield 4-nitrosodioxypropofol and finally 4-nitrosopropofol.
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Affiliation(s)
- M Cudic
- Institut de Chimie des Substances Naturelles, CNRS, Avenue de la Terrasse, Gif sur Yvette, F-91198, France
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11
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Cudic M, Dendane M, Houé-Levin C, Ducrocq C. Nitration of angiotensin II by .NO2 radicals and peroxynitrite. .NO protects against .NO2 radical reaction. Eur J Biochem 1999; 265:967-71. [PMID: 10518791 DOI: 10.1046/j.1432-1327.1999.00798.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To react with peptides, nitric oxide.NO has to be activated by oxidation, or by coupling with superoxide (O.-2) thereby producing peroxynitrite. In the course of.NO oxidation,.NO2 free radicals and N2O3 may be formed. Using gamma-irradiation methods, we characterized the products formed by these nitrogen oxides with angiotensin II. Angiotensin II is specifically nitrated at its tyrosinyl residue by.NO2 or peroxynitrite. Equimolecular amounts of each reagent in K+/Pi solutions at pH 7.4 led to 56% and 5% nitration yields, respectively. Nitrogen oxides produced by autoxidation of.NO, as well as.NO2 under.NO, reacted only with the arginine residue, giving a mixture of peptides containing citrulline, a N-(hydroxylamino-cyanamido-) instead of guanido group, and a conjugated diene derived from an arginine side-chain. However, nitrosation reactions by N2O3 occurred only when the initial concentration of.NO2 was 10 times that able to react with angiotensin II. Thus, in this case.NO appears to protect against.NO2 action.
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Affiliation(s)
- M Cudic
- Institut de Chimie des Substances Naturelles, Gif-sur-Yvette, France
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Fossier P, Blanchard B, Ducrocq C, Leprince C, Tauc L, Baux G. Nitric oxide transforms serotonin into an inactive form and this affects neuromodulation. Neuroscience 1999; 93:597-603. [PMID: 10465443 DOI: 10.1016/s0306-4522(99)00165-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nitric oxide is a highly reactive molecule, diffusible and therefore ubiquitous in the central nervous system. Consequently, nitric oxide or nitric oxide-derived nitrogen oxides must enter into contact with neuromodulators and they can modify these molecules, especially monoamines, and thus change their regulatory action on synaptic transmission. We tested this possibility on a well-known, identified cholinergic synapse of Aplysia buccal ganglion, in which we have found that evoked acetylcholine release was decreased by extracellularly applied serotonin. We show that this modulatory effect of serotonin was largely reduced not only in the presence of 3-morpholinosydnonimine, a nitric oxide donor, but also when endogenous nitric oxide synthase was activated. We have shown that this decrease in the serotonin effect is due to the formation of chemical derivatives of serotonin, mainly a symmetric serotonin dimer, 4-nitroso-serotonin and 4-nitro-serotonin, which are ineffective in reproducing the modulatory effect of serotonin. Serotonin is involved in the regulation of several central functions, such as sleep-wake activity or mood. The consequences of chemical modifications of serotonin by nitric oxide must be taken into account in physiological as well as pathological situations. In addition, our results highlight the importance of the physiological implications of interactions between free radicals and neuromediators in the nervous system.
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Affiliation(s)
- P Fossier
- Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS, Gif sur Yvette, France
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13
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Abstract
Peroxynitrite, the reaction product between nitric oxide (.NO) and superoxide, has been presumed to be a mediator of cellular and tissue injury in various pathological situations. It is formed at the convergence of two independent radical-generating metabolic pathways. Its biological effects are due to its reactivity towards a large range of molecules including amino acids such as cysteine, methionine, tyrosine and tryptophan, nucleic bases and antioxidants (e.g. phenolics, selenium- and metal-containing compounds, ascorbate and urate). Peroxynitrite reactions involve oxidation and nitration. The chemical properties depend on the presence of CO2 and metallic compounds as well as the concentrations of reagents and kinetic laws. This complex chemistry can be explained by the formation of several structural forms and active intermediates released from peroxynitrite.
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Affiliation(s)
- C Ducrocq
- Institut de Chimie des Substances Naturelles, CNRS, Gif-sur-Yvette, France
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Ducrocq C, Dendane M, Laprévote O, Serani L, Das BC, Bouchemal-Chibani N, Doan BT, Gillet B, Karim A, Carayon A, Payen D. Chemical modifications of the vasoconstrictor peptide angiotensin II by nitrogen oxides (NO, HNO2, HOONO)--evaluation by mass spectrometry. Eur J Biochem 1998; 253:146-53. [PMID: 9578472 DOI: 10.1046/j.1432-1327.1998.2530146.x] [Citation(s) in RCA: 30] [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] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nitric oxide (NO) and angiotensin II are natural regulators of blood pressure. Under aerobic conditions, NO is transformed into its higher oxides (N2O4, NO2, NO/NO2 or N2O3) and oxoperoxonitrate (currently named peroxynitrite) by coupling with superoxide. Previous studies have shown that these reactive nitrogen species should be involved in vivo in the transformation of cysteine and tyrosine into the corresponding nitrosothiol and 3-nitrotyrosine. In the present study, attention has been focused on the relative reactivities of HNO2, peroxynitrite, and NO in the presence of dioxygen, towards the arginine and tyrosine residues of the peptide angiotensin II. Nitration of the tyrosine residue is clearly the main reaction with peroxynitrite. By contrast, besides 20% of nitration of the tyrosine residue, NO in the presence of dioxygen leads to nitrosation reactions with the arginine residue similar to those observed with HNO2 at pH 5, possibly through the intermediate N2O3 reactive species. Angiotensin II is converted for the most part to peptides having lost either a terminal amine function or the whole guanido group, leading respectively to citrulline-containing angiotensin II or to a diene derivative. Identification established mainly by tandem mass spectrometry of peptidic by-products allows us to propose a cascade of nitrosations of all the amine functions of the arginine residue. Further in vivo studies show that transformations of the arginine residue in angiotensin II do not alter its vasoconstrictive properties, whereas nitration of the tyrosine residue totally inhibits them.
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Affiliation(s)
- C Ducrocq
- Institut de Chimie des Substances Naturelles, CNRS, Gif-sur-Yvette, France.
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Morot Gaudry-Talarmain Y, Moulian N, Meunier FA, Blanchard B, Angaut-Petit D, Faille L, Ducrocq C. Nitric oxide and peroxynitrite affect differently acetylcholine release, choline acetyltransferase activity, synthesis, and compartmentation of newly formed acetylcholine in Torpedo marmorata synaptosomes. Nitric Oxide 1997; 1:330-45. [PMID: 9441905 DOI: 10.1006/niox.1997.0141] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [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: 02/05/2023]
Abstract
Recent reports proposed that nitric oxide was a modulator of cholinergic transmission. Here, we examined the role of NO on cholinergic metabolism in a model of the peripheral cholinergic nervous synapse: synaptosomes from Torpedo electric organ. The presence of NO synthase was immunodetected in the cell bodies, in the nerve ending area of nerve-electroplate tissue and in the electroplates. Exogenous source of NO was provided from SIN1, a donor of NO and O2-., and an end-derivative peroxynitrite (ONOO-). SIN1 increased calcium-dependent acetylcholine (ACh) release induced by KCl depolarization or a calcium ionophore A23187. The formation of ONOO- was continuously followed by a new chemiluminescent assay. The addition of superoxide dismutase, that decreases the formation of ONOO-, did not impair the stimulation of ACh release, suggesting that NO itself was the main stimulating agent. When the endogenous source of NO was blocked by proadifen, an inhibitor of cytochrome P450 activity of NO synthase, both KCl- and A23187-induced ACh release were abolished; nevertheless, the inhibitor Ng-monomethyl-L-arginine did not modify ACh release when applied in a short time duration of action. Both NO synthase inhibitors reduced the synthesis of ACh from the radioactive precursor acetate and its incorporation into synaptic vesicles as did ONOO- chemically synthesized or formed from SIN1. In addition, choline acetyltransferase activity was strongly inhibited by ONOO- and SIN1 but not by the NO donors SNAP and SNP or, by NO synthase inhibitors. Altogether these results indicate that NO and ONOO modulate presynaptic cholinergic metabolism in the micromolar range, NO (up to 100 microM) being a stimulating agent of ACh release and ONOO- being an inhibitor of ACh synthesis and choline acetyltransferase activity.
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Abstract
The reactivity of catecholamines with nitrogen oxides formed from NO in aerated solutions, nitrite, and peroxynitrite was evaluated. Dopamine and norepinephrine in aerobic buffer (pH 7.4) were almost completely converted to their 6-nitro-derivatives by nitric oxide (NO) at room temperature, while epinephrine was nitrated and above all oxidized. The products obtained from each catecholamine treated with sodium nitrite at pH 4-7 were compared to those produced by NO at pH 7.4. Peroxynitrite, which can nitrate tyrosinyl residues, did not produce nitro-derivatives, only oxidized ones. The physiological relevance, particularly for the vascular and nervous system, is discussed. Catecholamine oxidation reactions could be relevant to physiological conditions and also explain neurotoxicity in Parkinson's disease and aging. Nitration reactions, requiring such high NO concentrations, do not seem possible to occur directly under normal physiological conditions, but could take place in acidic vesicules where nitrite, catecholamines, and their nitrated products could accumulate. Finally, the ability of dopamine to increase 2',5'-cyclic adenosine monophosphate (cAMP) formation in cultured striatal neurons was blocked by its nitration by NO or its nitrogen oxide derivatives.
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Affiliation(s)
- C Daveu
- INSERM U 114, Collège de France, Paris
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17
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Boitel-Conti M, Gontier E, Laberche JC, Ducrocq C, Sangwan-Norreel BS. Inducer effect of Tween 20 permeabilization treatment used for release of stored tropane alkaloids inDatura innoxia Mill. hairy root cultures. Plant Cell Rep 1996; 16:241-244. [PMID: 24177561 DOI: 10.1007/bf01890876] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/1995] [Revised: 02/08/1996] [Indexed: 06/02/2023]
Abstract
The effects of Tween 20 as permeabilizing agent on tropane alkaloids fromDatura innoxia Mill. hairy root cultures have been studied. The kinetics of the alkaloid release is detailed and shows three different stages: an initial rapid increase of the alkaloid level within the roots and in the culture medium, followed by a slower but higher increase of the alkaloid concentration in the medium. During this phase, the alkaloid concentration within the roots returned to a lower value. Finally, after a longer time, the quantity of hyoscyamine in the medium decreased significantly with a variable rate. According to the total alkaloid content per flask determinations under different conditions, it is clearly demonstrated that Tween treatment permeabilized the roots, but also acted as an inducer.
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Affiliation(s)
- M Boitel-Conti
- Laboratoire Androgenèse et Biotechnologie, Faculté des Sciences, Université de Picardie Jules Verne, 33, rue Saint Len, F-80039, Amiens Cédex 01, France
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Boitel-Conti M, Gontier E, Laberche JC, Ducrocq C, Sangwan-Norreel BS. Permeabilization of Datura innoxia hairy roots for release of stored tropane alkaloids. Planta Med 1995; 61:287-90. [PMID: 17238082 DOI: 10.1055/s-2006-958079] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The effects of tween 20 as permeabilizing agent on tropane alkaloids from Datura innoxia Mill, hairy roots have been studied. For various tween 20 concentrations both hyoscyamine and scopolamine accumulated in the culture medium. Plant material viability could be preserved after a 24 hours-2% tween 20 concentration treatment. The time-course study of alkaloid release showed that the maximum of excretion occurred after a 20 hour contact with tween 20. At that time, a concentration of hyoscyamine superior to 25 mg/l was detected in the medium.
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19
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Abstract
Itaconate biosynthesis was studied in intact cells of high-yield (RC4') and low-yield (CM85J) strains of the fungus Aspergillus terreus by methods (tracers, nuclear magnetic resonance spectroscopy, and mass spectroscopy) that did not interfere with metabolism. Itaconate formation in RC4' required de novo protein biosynthesis. Krebs cycle intermediates increased in both strains during the production of itaconic acid. The Embden-Meyerhof-Parnas pathway and the Krebs cycle were shown to be involved in this biosynthesis by using 14C- and 13C-labelled substrates and nuclear magnetic resonance spectroscopy. A metabolic pathway for itaconate formation from glucose in A. terreus is proposed.
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Affiliation(s)
- P Bonnarme
- Institut de Chimie des Substances Naturelles, Centre National de la Recherche Scientifique, Gif sur Yvette, France
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20
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Ducrocq C, Sangwan RS, Sangwan-Norreel BS. Production of Agrobacterium-mediated transgenic fertile plants by direct somatic embryogenesis from immature zygotic embryos of Datura innoxia. Plant Mol Biol 1994; 25:995-1009. [PMID: 7919219 DOI: 10.1007/bf00014673] [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] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
This work describes a new method to obtain transgenic somatic embryos from Agrobacterium-infected immature zygotic embryos of Datura innoxia. It has several advantages over previous transformation methods such as the absence of a callus phase, an average transformation rate of 76% and a high regeneration frequency. Critical steps for optimal transformation were the embryo stage and a short preculture treatment. The marker gene beta-glucuronidase and light microscopy were used to identify the competent embryogenic cells which, after transformation, passed through the classical stages of embryo development. The transgenes were transmitted to the progeny in a Mendelian fashion. The plants regenerated via direct somatic embryogenesis were cytologically and morphologically uniform. We also observed that: (1) wounding or wound-induced divisions were not required for zygotic embryo transformation; (2) epidermal cells were competent for both transformation and regeneration; and (3) competency for Agrobacterium infection was developmental stage-specific. This new method should facilitate the development of new strategies to routinely transform recalcitrant plant species.
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Affiliation(s)
- C Ducrocq
- Laboratoire Androgenèse et Biotechnologie, Université de Picardie Jules Verne, Amiens, France
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21
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Abstract
Nitric oxide is synthesized in mammalian cells from L-arginine or from pharmaceutical drugs. It forms paramagnetic complexes with some metalloproteins, inhibiting key enzymes in DNA synthesis, mitochondrial respiration, iron metabolism, etc. This article reviews how electron paramagnetic resonance spectroscopy helps to detect unambiguously such specific molecular targets for NO in mammalian whole cells and organelles. EPR has also been used for the detection of spin adducts of free NO by spin-trapping methods.
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Affiliation(s)
- Y Henry
- Institut Curie, INSERM U 350, Orsay, France
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22
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Delaforge M, Servent D, Wirsta P, Ducrocq C, Mansuy D, Lenfant M. Particular ability of cytochrome P-450 CYP3A to reduce glyceryl trinitrate in rat liver microsomes: subsequent formation of nitric oxide. Chem Biol Interact 1993; 86:103-17. [PMID: 8448809 DOI: 10.1016/0009-2797(93)90115-f] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Glyceryl trinitrate was denitrated in rat hepatic subcellular fractions, with formation of glyceryl dinitrates and glyceryl mononitrates. Among differently treated-rat liver microsomes, the highest microsomal activity was obtained under anaerobic conditions with microsomal preparations from dexamethasone-treated rats and NADPH. The reaction was inhibited by O2, CO, miconazole, dihydroergotamine and troleandomycin showing that it was catalyzed by cytochrome P-450 CYP3A isoforms. The formation of a transient cytochrome P-450 Fe(II)-NO complex during this reaction was shown by visible spectroscopy. The cytosolic activity was shown to be dependent on glutathione and glutathione transferase and was not inhibited by dioxygen. In the hepatic 9000 x g supernatant containing both NADPH and cytochrome P-450 and glutathione and glutathione transferase, the cytochrome P-450-dependent reaction accounts for 30-40% of the total denitration activity observed under anaerobic conditions, using 100 microM GTN.
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Affiliation(s)
- M Delaforge
- Université René Descartes URA 400 CNRS, Paris, France
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23
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Servent D, Ducrocq C, Henry Y, Servy C, Lenfant M. Multiple enzymatic pathways involved in the metabolism of glyceryl trinitrate in Phanerochaete chrysosporium. Biotechnol Appl Biochem 1992; 15:257-66. [PMID: 1326993] [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: 12/26/2022]
Abstract
A study of glyceryl trinitrate metabolism by a filamentous fungus, Phanerochaete chrysosporium, carried out with the 14C-labeled substrate, provides evidence for a multienzymatic system leading to di- and mononitrate derivatives. At least two independent enzymatic activities were detected in the cytosolic fraction: an aerobic glutathione S-transferase activity and an anaerobic NADPH-dependent soluble cytochrome P450-like activity. Other hemoproteins with enzymatic activities dependent upon the presence of NADPH or ferrous ions were also detected in the microsomal fraction. Electron paramagnetic resonance spectra characteristic of an interaction between a hemoprotein and nitric oxide appeared in these two subcellular fractions during the anaerobic metabolism of glyceryl trinitrate.
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Affiliation(s)
- D Servent
- Institut de Chimie des Substances Naturelles, CNRS, F 91198 Gif-sur-Yvette, France
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24
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Servent D, Ducrocq C, Henry Y, Guissani A, Lenfant M. Nitroglycerin metabolism by Phanerochaete chrysosporium: evidence for nitric oxide and nitrite formation. Biochim Biophys Acta 1991; 1074:320-5. [PMID: 1648402 DOI: 10.1016/0304-4165(91)90170-l] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have demonstrated that a filamentous fungus Phanerochaete chrysosporium converts glyceryl trinitrate (GTN) into its di- and mononitrate derivatives concurrently with the formation of nitric oxide detected by electron paramagnetic resonance (EPR), and the formation of nitrite. The metabolisms of nitrite and nitrate by the fungus are evaluated and taken into account when considering GTN degradation. Lack of evidence for nitrate formation from GTN suggests that an esterase-type activity is not involved. Furthermore, the kinetics of appearance of the hemoprotein-NO and non-heme protein-NO (FeS-NO) complexes indicate that an enzymatic process producing NO directly from GTN may be involved concurrently with a glutathione transferase-like system.
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Affiliation(s)
- D Servent
- Institut de Chimie des Substances Naturelles, CNRS, Gif/Yvette, France
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25
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Henry Y, Ducrocq C, Drapier JC, Servent D, Pellat C, Guissani A. Nitric oxide, a biological effector. Electron paramagnetic resonance detection of nitrosyl-iron-protein complexes in whole cells. Eur Biophys J 1991; 20:1-15. [PMID: 1657584 DOI: 10.1007/bf00183275] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Nitric oxide has been used for more than 20 years as an electron paramagnetic resonance probe of oxygen binding sites in oxygen-carriers and oxygen-metabolizing metalloenzymes. The high reactivity of NO with oxygen and the superoxide anion and its high affinity for metalloproteins led biochemists to consider NO as a highly toxic compound for a living cell. This assertion has recently been reconsidered following a number of discoveries of great significance: the finding of the activation of guanylate cyclase by NO, the recognition that NO is the precursor of nitrite and nitrate ions released in the activation of macrophages by endotoxin and cytokines, evidence that NO is an Endothelium-Derived Relaxing Factor, and the discovery of NO-biosynthesis from L-arginine, a pathway common in various biological cell-to-cell signalling processes. It is now admitted that NO plays a key bioregulatory role within mammalian cells, between cells of different types and in the host defence response. In the present review we have attempted to give a general picture of what is known of the chemical, physical, biochemical and biophysical properties of NO among the various nitrogen oxides. We have focussed on the structural information that can be obtained by electron paramagnetic resonance spectroscopy of nitrosyl-metalloprotein complexes. Finally we have shown how molecular targets of nitric oxide can be characterized, within whole cells, by electron paramagnetic resonance spectroscopy.
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Affiliation(s)
- Y Henry
- Institut Curie, Unité INSERM 219, Orsay, France
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26
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Sangwan RS, Ducrocq C, Sangwan-Norreel BS. Effect of culture conditions on Agrobacterium-mediated transformation in datura. Plant Cell Rep 1991; 10:90-3. [PMID: 24221401 DOI: 10.1007/bf00236464] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/1990] [Revised: 12/20/1990] [Indexed: 05/09/2023]
Abstract
A two step selection procedure is described for high frequency transformation and regeneration of transgenic plants by coculture of leaf discs of Datura innoxia with Agrobacterium tumefaciens carrying binary vectors. Leaf discs were cocultured with disarmed A. tumefaciens vectors pGS Glucl, pGSTRN943, pGV2260 and pBI121, and subcultured on regeneration media containing kanamycin. Kanamycinresistant, putatively "transformed" callus and vegetative buds were isolated, and subcultured on media containing reduced amounts of growth regulators and kanamycin to induce shooting. Rooted shoots produced normal fertile plants. Transformation frequency was related to duration of preculture, co-culture, and the bacterial strain used. With pGS Glue 1, a 3 day co-culture resulted in 70% of leaf discs being transformed. Transformation was confirmed by histochemical test for GUS activity, by the ability of leaf discs to initiate callus and from NPTII test, and Southern blot analysis. Progeny of the transgenic plants showed Mendelian segregation for kanamycin resistance.
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Affiliation(s)
- R S Sangwan
- Laboratoire Androgenèse et Biotechnologie, Université de Picardie, Faculté des Sciences, 33 rue Saint leu, 80039, Amiens Cédex, France
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27
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Coche G, Gottrand F, Sevenet F, Ducrocq C. [Hepatic steatosis in obesity in children]. J Radiol 1991; 72:235-7. [PMID: 2072341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The fatty liver infiltrations of the children are not uncommon and are often seen in particular diseases, mainly related to intoxication or metabolic diseases. The authors reported a case of heterogeneous fatty liver infiltration due to obesity with a good evolution after a hypocaloric diet.
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Affiliation(s)
- G Coche
- Service de Radiologie, Clinique du Mail, Amiens
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28
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Sevenet F, Coche G, Dupuis JL, Ducrocq C, Descombes P. [Acute pancreatitis and viral hepatitis A. Report of a case]. Ann Gastroenterol Hepatol (Paris) 1990; 26:291-2. [PMID: 2082806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We are reporting the case of a patient with acute pancreatitis associated with viral A hepatitis with satisfactory recovery. To our knowledge, two similar cases have been reported.
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29
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Ducrocq C, Servy C, Lenfant M. Formation of glyceryl 2-mononitrate by regioselective bioconversion of glyceryl trinitrate: efficiency of the filamentous fungus Phanerochaete chrysosporium. Biotechnol Appl Biochem 1990; 12:325-30. [PMID: 2113815] [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: 12/30/2022]
Abstract
Various microorganisms have been evaluated for their ability to hydrolyze glyceryl trinitrate (GTN) to glyceryl dinitrates and mononitrates. Provided that the GTN extracellular concentration was under the lethal dose, metabolite formation and regioselectivity depend on the nature of the strain used. In particular, Phanerochaete chrysosporium at a sublethal dose (3 mM) converts GTN into 1,2-glyceryl dinitrate and 2-glyceryl mononitrate (2-GMN) with a 80% regioselectivity in both steps. This bioconversion, when carried out in fermentors at 28 degrees C, allowed formation of 2-GMN at a rate of 12 mumol/h/g of dried mycelium. Successive batches of 3 mM GTN could be converted into 2-GMN as long as consecutive additions of glycerol or glucose were effected to ensure cell survival and the efficiency of the enzymatic system involved.
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Affiliation(s)
- C Ducrocq
- Institut de Chimie des Substances Naturelles, CNRS, Gif sur Yvette, France
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30
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Abstract
Glyceryl trinitrate (GTN) 2 mM was quantitatively converted into its 1 and 2 mononitrate derivatives by Geotrichum candidum, with consumption of the nitrite ions produced. The conversion proceeded at a rate independent of the addition of either organic carbon or organic nitrogen sources. Eight batches of nitrate ester, which were added every 24 hours, were successfully converted as far as during the bioconversion process GTN concentration did not exceed 2 mM. When those limiting conditions were not observed, dramatic toxicity of GTN was noticed.
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Affiliation(s)
- C Ducrocq
- Institut de Chimie des Substances Naturelles, Centre National de la Recherche Scientifique (C.N.R.S.), Gif sur Yvette, France
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31
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Servent D, Delaforge M, Ducrocq C, Mansuy D, Lenfant M. Nitric oxide formation during microsomal hepatic denitration of glyceryl trinitrate: involvement of cytochrome P-450. Biochem Biophys Res Commun 1989; 163:1210-6. [PMID: 2506859 DOI: 10.1016/0006-291x(89)91106-6] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.6] [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: 01/01/2023]
Abstract
Glyceryl trinitrate was denitrated by rat liver microsomes in the presence of NADPH with formation of a mixture of glyceryl dinitrates and glyceryl mononitrates. The highest activity was obtained under anaerobic conditions and the reaction was inhibited by O2 indicating that it is a reductive denitration. It was also inhibited by CO, metyrapone and miconazole showing that it was catalyzed by cytochrome P-450. Finally the formation of the cytochrome P-450-Fe(II)-NO complex during this reaction was shown by visible spectroscopy. These data demonstrate that microsomal reductive denitration of glyceryl trinitrate is catalyzed by cytochrome P-450 and can be involved in the formation of the endothelium-derived relaxing factor (EDRF = nitric oxide).
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Affiliation(s)
- D Servent
- Institut de Chimie des Substances Naturelles CNRS, France
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32
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Abstract
31P High resolution nuclear magnetic resonance studies have been carried out on the P388D1 tumoral cell line and the BCG elicited alveolar rabbit macrophages both in sedimented cells and in perfused agarose-embedded cells. When the cells were sufficiently oxygenated, the phosphorylated sugars and ATP concentrations attained high levels. The intensity of the peak representing phosphorylated sugars varied inversely with ATP level when macrophagic cells were treated by NaF. The identities of the phosphorylated sugars were revealed by 1H and 31P NMR studies of the P 388D1 cells perchloric extracts.
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Decottignies-Le Maréchal P, Ducrocq C, Marquet A, Azerad R. The stereochemistry of hydrogen abstraction in vitamin K-dependent carboxylation. J Biol Chem 1984; 259:15010-2. [PMID: 6150930] [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: 01/18/2023] Open
Abstract
The stereochemistry of the hydrogen abstraction in the vitamin K-dependent carboxylation of synthetic peptides has been investigated; the carboxylation rates of various peptidic substrates containing a stereospecifically 4-monodeuterated glutamic acid residue have been compared to that of nondeuterated peptides. A significant isotope effect was found only with the substrates containing (4S)-4-deuterated glutamic acid. These data reveal that the rat liver microsomal vitamin K-dependent carboxylase acts stereospecifically in abstracting the 4-pro-S hydrogen of the glutamyl residue. The low values of the measured isotope effects indicate that the hydrogen abstraction does not constitute a limiting step in the carboxylation mechanism.
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35
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Ducrocq C, Fraisse D, Tabet JC, Azerad R. An enzymatic method for the determination of enantiomeric composition and absolute configuration of deuterated or tritiated succinic acid. Anal Biochem 1984; 141:418-22. [PMID: 6149705 DOI: 10.1016/0003-2697(84)90064-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The distribution of hydrogen isotope between pro-R and pro-S positions of succinic acid has been determined by comparison of its isotopic content before and after incubation with isocitrate lyase. This enzyme, in the presence of glyoxylate, exchanges exclusively the pro-S protons of succinate with water (M. Sprecher, R. Berger, and D. B. Sprinson (1964) J. Biol. Chem. 239, 4268-4271). With [1-14C,2(R,S)-3H]succinate as substrate, the exchange was easily followed by the decrease of 3H/14C ratio (dried aliquots), which accounted for the high isotopic effect of this reaction. The final ratio was within +/- 5% of the theoretical one. The evolution of the exchange of deuterated succinate added with [1-14C,2(R,S)-3H]succinate acid was again followed by 3H/14C ratio. The deuterium content of [2,3-2H2]succinic acid, [2-2H2]succinic acid (derived from L-[4-2H2]glutamic acid by oxidation) and of the corresponding succinates isolated after incubation with isocitrate lyase was determined by gas chromatography-mass spectroscopy of their dimethylester under NH4+ chemical ionization. This method provides the basis for a quantitative measurement of the distribution of hydrogen isotopes in unsymmetrically 2-labeled succinate or 4-labeled glutamate.
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36
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Ducrocq C. [Nursing records. An experience at the Hospital of Dunkirk]. Soins 1983:31-3. [PMID: 6552038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
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37
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Ducrocq C, Wendling F, Tourbez-Perrin M, Rivalle C, Tambourin P, Pochon F, Bisagni E, Chermann JC. Structure-activity relationships in a series of newly synthesized 1-amino-substituted ellipticine derivatives. J Med Chem 1980; 23:1212-6. [PMID: 7452670 DOI: 10.1021/jm00185a012] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The synthesis of a series of 1-amino-substituted pyrido[4,3-b]carbazole derivatives, based on the substitution of corresponding 1-chloroellipticines, is reported. The cytotoxic properties on tumor cells grown in vitro, the in vivo acute toxicity of the most potent in vitro cytotoxic compounds, and the antitumor properties toward the L1210 leukemia system are described. No correlation between the apparent association constant to DNA and the in vitro cytotoxicity or the in vito antitumor efficiency could be observed in this series. 9-Hydroxylated derivatives were more cytotoxic in vitro than the corresponding 9-methoxylated compounds. However, their antitumor efficiencies on the in vivo experimental systems do not confirm the advantage of demethylation. The presence of a [(dialkylamino)alkyl]amino side chain at the 1 position of ellipticines increases the antitumor potency: 1-[[3-(diethylamino)propyl]amino]-5,11-dimethyl-6H-pyrido[4,3-b]carbazole (5) is a very potent antitumor compound (% ILS of 134 on the L1210 leukemia system).
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38
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Chermann JC, Gruest J, Montagnier L, Wendling F, Tambourin P, Perrin M, Pochon F, Ducrocq C, Rivalle C, Bisagni E. [Cytotoxic and antitumor activity of a new series of heterocyclic compounds: dipyrido (4,3-b) (3,4-f) indoles]. C R Acad Hebd Seances Acad Sci D 1977; 285:945-8. [PMID: 410562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Among newly synthesized compounds derived from the dipyrido [4,3-b] [3,4-f] indole nucleus, two have proved to be particularly active in vitro and in vivo. Their cytotoxic effects on cultured cells have been determined. At non toxic doses, they displayed a pronounced inhibitory effect on experimental L1210 Leukemia. These compounds have a strong affinity for DNA molecules.
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39
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40
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