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Solé F, Lesport JF, Heitz A, Mennecart B. A new gigantic carnivore (Carnivora, Amphicyonidae) from the late middle Miocene of France. PeerJ 2022; 10:e13457. [PMID: 35726261 PMCID: PMC9206431 DOI: 10.7717/peerj.13457] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 04/27/2022] [Indexed: 01/14/2023] Open
Abstract
Serravallian terrestrial vertebrates are very uncommon in the northern margin of the Pyrenean Mountains. A mandible of a new large sized amphicyonid (ca. 200 kg) is here described from the marine deposits of Sallepisse (12.8-12.0 Mya). Despite that this new taxon is close in size to some European amphicyonids from the Miocene (e.g., Amphicyon, Megamphicyon, and Magericyon), the unique morphology of its p4, unknown in this clade, allows the erection of the new genus Tartarocyon cazanavei nov. gen. & sp. This taxon may be derived from a Cynelos-type amphicyonine. The description of this new taxon highlights the erosion of the ecological and morphological diversity of the Amphicyonidae in response to well-known Miocene events (i.e., Proboscidean Datum Event, Middle Miocene Climatic Transition, Vallesian Crisis).
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Affiliation(s)
- Floréal Solé
- Royal Belgian Institute of Natural Sciences, Brussels, Belgium
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Moling S, Heitz A, Ruyer J. Reliability of deep branch of ulnar nerve identification in interosseous-to-ulnar motor nerve transfer: A cadaver study of 20 wrists. Hand Surg Rehabil 2021; 41:103-106. [PMID: 34856362 DOI: 10.1016/j.hansur.2021.11.006] [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] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 11/02/2021] [Accepted: 11/04/2021] [Indexed: 11/19/2022]
Abstract
Reinnervation of the intrinsic hand muscles after proximal ulnar nerve repair is often unsatisfactory. Promising results have nevertheless been reported recently for supercharged end-to-side anterior interosseous to deep branch of the ulnar nerve (DBUN) transfer. The aim of this study was to determine whether the DBUN can be reliably identified without retrograde intraneural dissection from Guyon's canal. Twenty cadaveric wrists were dissected. In a first stage, nerve transfer was performed through a limited 4 cm incision without releasing Guyon's canal. In a second stage, correct identification of the DBUN was assessed by retrograde intraneural dissection from its point of exit from Guyon's canal. The DBUN was correctly identified in 18 of the 20 wrists (90%). Although anatomical landmarks provide valuable clues, identifying the DBUN by neurolysis is technically challenging. All the elements required for nerve transfer can be exposed through a 4 cm incision, but the DBUN was nevertheless incorrectly identified in 10% of cases. Guyon canal release seems advisable to guarantee correct DBUN identification.
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Affiliation(s)
- S Moling
- Faculté de Médecine Lyon Est (Université Claude Bernard Lyon 1), 8 Avenue Rockefeller, 69003 Lyon, France
| | - A Heitz
- Service de Chirurgie du Membre Supérieur - SOS Main, Hôpital Edouard Herriot, 5 Place d'Arsonval, 69003 Lyon, France.
| | - J Ruyer
- Centre de la Main, Clinique de la Sauvegarde (Lyon-Ortho-Clinic), 29b Avenue des Sources, 69009 Lyon, France
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Vinee F, Grobnicu O, Errera C, Gomart G, Tuzin N, Heitz A, Liverneaux P, Bourcier T. Assessment of Tactile Sensitivity Threshold Using Cochet-Bonnet Esthesiometer and Semmes-Weinstein Monofilaments and Their Use in Corneal Neurotization. Ophthalmic Plast Reconstr Surg 2021; 37:S39-S43. [PMID: 32773513 DOI: 10.1097/iop.0000000000001788] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Although the Cochet-Bonnet esthesiometer (CBE) measures corneal sensitivity, it has heretofore only been tested on the index pulp. Tactile skin sensitivity thresholds are measured with Semmes-Weinstein monofilaments (SWM). This study measured skin sensitivity thresholds in healthy individuals using CBE and SWM, and compared both instruments in territories involved in corneal neurotization. METHODS Overall, 27 healthy individuals were tested by a single examiner at 9 territories on the face, neck, forearm, and leg, using 20-thread SWM and CBE with a diameter of 0.12 mm. Both sides were tested. Thresholds were compared for both instruments and between the different territories using Bayesian methods. RESULTS Mean sensitivity levels for SWM ranged from 0.010 to 1.128 g, while mean sensitivity levels for CBE ranged from 0.006 to 0.122 g. Thresholds measured with SWM were significantly higher than with CBE. Both instruments demonstrated higher thresholds in the leg territory than the forearm. However, the forearm presented higher thresholds than the head territories. No significant differences were found between the head territories themselves. Overall, right-side territories exhibited lower thresholds than left-side territories. CONCLUSIONS We have reported the first mapping of skin sensitivity thresholds using CBE. Thresholds measured with CBE and SWM were coherent. The use of CBE on the skin is particularly relevant to the field of corneal neurotization.
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Affiliation(s)
- Frédéric Vinee
- Ophthalmology Department, Strasbourg University Hospital, FMTS
| | - Oana Grobnicu
- Hand Surgery Department, Strasbourg University Hospital, FMTS
| | | | | | - Nicolas Tuzin
- Biostatistics Department, Strasbourg University Hospital, FMTS, Strasbourg, France
| | - Antoine Heitz
- Ophthalmology Department, Strasbourg University Hospital, FMTS
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Tan J, Allard S, Gruchlik Y, McDonald S, Joll CA, Heitz A. Impact of bromide on halogen incorporation into organic moieties in chlorinated drinking water treatment and distribution systems. Sci Total Environ 2016; 541:1572-1580. [PMID: 26490534 DOI: 10.1016/j.scitotenv.2015.10.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 10/08/2015] [Accepted: 10/08/2015] [Indexed: 06/05/2023]
Abstract
The impact of elevated bromide concentrations (399 to 750 μg/L) on the formation of halogenated disinfection by-products (DBPs), namely trihalomethanes, haloacetic acids, haloacetonitriles, and adsorbable organic halogen (AOX), in two drinking water systems was investigated. Bromine was the main halogen incorporated into all of the DBP classes and into organic carbon, even though chlorine was present in large excess to maintain a disinfectant residual. Due to the higher reactivity of bromine compared to chlorine, brominated DBPs were rapidly formed, followed by a slower increase in chlorinated DBPs. Higher bromine substitution and incorporation factors for individual DBP classes were observed for the chlorinated water from the groundwater source (lower concentration of dissolved organic carbon (DOC)), which contained a higher concentration of bromide, than for the surface water source (higher DOC). The molar distribution of adsorbable organic bromine to chlorine (AOBr/AOCl) for AOX in the groundwater distribution system was 1.5:1 and almost 1:1 for the surface water system. The measured (regulated) DBPs only accounted for 16 to 33% of the total organic halogen, demonstrating that AOX measurements are essential to provide a full understanding of the formation of halogenated DBPs in drinking waters. In addition, the study demonstrated that a significant proportion (up to 94%) of the bromide in source waters can be converted AOBr. An evaluation of AOBr and AOCl through a second groundwater treatment plant that uses conventional treatment processes for DOC removal produced 70% of AOX as AOBr, with 69% of the initial source water bromide converted to AOBr. Exposure to organobromine compounds is suspected to result in greater adverse health consequences than their chlorinated analogues. Therefore, this study highlights the need for improved methods to selectively reduce the bromide content in source waters.
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Affiliation(s)
- J Tan
- Curtin Water Quality Research Centre, Department of Chemistry, Curtin University, GPO Box U1987, Perth, WA 6845, Australia
| | - S Allard
- Curtin Water Quality Research Centre, Department of Chemistry, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
| | - Y Gruchlik
- Curtin Water Quality Research Centre, Department of Chemistry, Curtin University, GPO Box U1987, Perth, WA 6845, Australia
| | - S McDonald
- Curtin Water Quality Research Centre, Department of Chemistry, Curtin University, GPO Box U1987, Perth, WA 6845, Australia
| | - C A Joll
- Curtin Water Quality Research Centre, Department of Chemistry, Curtin University, GPO Box U1987, Perth, WA 6845, Australia
| | - A Heitz
- Department of Civil Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia
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Affiliation(s)
- Jeremy Danan
- Department of Ophthalmology, Strasbourg University Hospital, Fédération de Médecine Translationnelle de Strasbourg, University of Strasbourg, Strasbourg, France
| | - Antoine Heitz
- Department of Ophthalmology, Strasbourg University Hospital, Fédération de Médecine Translationnelle de Strasbourg, University of Strasbourg, Strasbourg, France
| | - Tristan Bourcier
- Department of Ophthalmology, Strasbourg University Hospital, Fédération de Médecine Translationnelle de Strasbourg, University of Strasbourg, Strasbourg, France
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Heitz A, Sauer A. [Ankyloblepharon filiforme adnatum]. J Fr Ophtalmol 2015; 38:174. [PMID: 25596775 DOI: 10.1016/j.jfo.2014.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 05/02/2014] [Indexed: 11/25/2022]
Affiliation(s)
- A Heitz
- Service d'ophtalmologie, nouvel hôpital civil, hôpitaux universitaires de Strasbourg, BP 426, 67091 Strasbourg, France
| | - A Sauer
- Service d'ophtalmologie, nouvel hôpital civil, hôpitaux universitaires de Strasbourg, BP 426, 67091 Strasbourg, France.
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Abstract
The oxidation of dissolved manganese(II) (Mn(II)) during chlorination is a relatively slow process which may lead to residual Mn(II) in treated drinking waters. Chemical Mn(II) oxidation is autocatalytic and consists of a homogeneous and a heterogeneous process; the oxidation of Mn(II) is mainly driven by the latter process. This study demonstrates that Mn(II) oxidation during chlorination is enhanced in bromide-containing waters by the formation of reactive bromine species (e.g., HOBr, BrCl, Br2O) from the oxidation of bromide by chlorine. During oxidation of Mn(II) by chlorine in bromide-containing waters, bromide is recycled and acts as a catalyst. For a chlorine dose of 1 mg/L and a bromide level as low as 10 μg/L, the oxidation of Mn(II) by reactive bromine species becomes the main pathway. It was demonstrated that the kinetics of the reaction are dominated by the adsorbed Mn(OH)2 species for both chlorine and bromine at circumneutral pH. Reactive bromine species such as Br2O and BrCl significantly influence the rate of manganese oxidation and may even outweigh the reactivity of HOBr. Reaction orders in [HOBr]tot were found to be 1.33 (±0.15) at pH 7.8 and increased to 1.97 (±0.17) at pH 8.2 consistent with an important contribution of Br2O which is second order in [HOBr]tot. These findings highlight the need to take bromide, and the subsequent reactive bromine species formed upon chlorination, into account to assess Mn(II) removal during water treatment with chlorine.
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Affiliation(s)
- S Allard
- Curtin Water Quality Research Centre, Department of Chemistry, Curtin University , GPO Box U1987, Perth WA 6845, Australia
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Saleh M, Heitz A, Bourcier T, Speeg C, Delbosc B, Montard M, Gaucher D. Sutureless intrascleral intraocular lens implantation after ocular trauma. J Cataract Refract Surg 2013; 39:81-86. [PMID: 23245361 DOI: 10.1016/j.jcrs.2012.08.063] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 07/25/2012] [Accepted: 08/13/2012] [Indexed: 11/24/2022]
Abstract
PURPOSE To report the results and safety of sutureless intrascleral haptic fixation in traumatized eyes and to compare this procedure with retropupillary iris-claw intraocular lens (IOL) fixation. SETTING University Hospital of Strasbourg, Strasbourg, France. DESIGN Interventional case series. METHODS Patients with traumatic cataract and severely damaged capsular bags were divided into 2 groups (Group 1: intrascleral IOLs [Acrysof MN60 AC]; Group 2: retropupillary iris-claw IOLs [Verisyse]). The main outcome was the final visual acuity. The surgically induced astigmatism (SIA) was calculated by the vectorial method. RESULTS Twenty-six eyes of 23 patients were studied, 8 eyes in Group 1 and 18 eyes in Group 2. The mean follow-up was 14 months. There was no difference in corrected distance visual acuity (CDVA) at the time of the surgery (P>.05). The mean CDVA (logMAR) was 1.68 ± 1.15 (SD) preoperatively and 0.55 ± 0.9 postoperatively in Group 1 (P = .03) and 1.11 ± 1.13 and 0.32 ± 0.47, respectively, in Group 2 (P = .003). The final CDVA was not different between groups (P>.05). The mean SIA was 1.91 ± 1.66 diopters (D) in Group 1 and 2.74 ± 1.92 D in Group 2 (P>.05). No intraoperative complications occurred in Group 2; a haptic broke in Group 1. Macular edema occurred in both groups. CONCLUSIONS Sutureless intrascleral IOLs corrected posttraumatic aphakia. The SIA was comparable between groups. This procedure should be considered after trauma when other implantation techniques are not possible.
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Affiliation(s)
- Maher Saleh
- From the Department of Ophthalmology (Saleh, Heitz, Bourcier, Speeg, Gaucher), Nouvel Hopital Civil, University Hospital of Strasbourg, Strasbourg, and the University Hospital of Besançon (Saleh, Delbosc, Montard), University of Franche-Comté, Besancon, France.
| | - Antoine Heitz
- From the Department of Ophthalmology (Saleh, Heitz, Bourcier, Speeg, Gaucher), Nouvel Hopital Civil, University Hospital of Strasbourg, Strasbourg, and the University Hospital of Besançon (Saleh, Delbosc, Montard), University of Franche-Comté, Besancon, France
| | - Tristan Bourcier
- From the Department of Ophthalmology (Saleh, Heitz, Bourcier, Speeg, Gaucher), Nouvel Hopital Civil, University Hospital of Strasbourg, Strasbourg, and the University Hospital of Besançon (Saleh, Delbosc, Montard), University of Franche-Comté, Besancon, France
| | - Claude Speeg
- From the Department of Ophthalmology (Saleh, Heitz, Bourcier, Speeg, Gaucher), Nouvel Hopital Civil, University Hospital of Strasbourg, Strasbourg, and the University Hospital of Besançon (Saleh, Delbosc, Montard), University of Franche-Comté, Besancon, France
| | - Bernard Delbosc
- From the Department of Ophthalmology (Saleh, Heitz, Bourcier, Speeg, Gaucher), Nouvel Hopital Civil, University Hospital of Strasbourg, Strasbourg, and the University Hospital of Besançon (Saleh, Delbosc, Montard), University of Franche-Comté, Besancon, France
| | - Michel Montard
- From the Department of Ophthalmology (Saleh, Heitz, Bourcier, Speeg, Gaucher), Nouvel Hopital Civil, University Hospital of Strasbourg, Strasbourg, and the University Hospital of Besançon (Saleh, Delbosc, Montard), University of Franche-Comté, Besancon, France
| | - David Gaucher
- From the Department of Ophthalmology (Saleh, Heitz, Bourcier, Speeg, Gaucher), Nouvel Hopital Civil, University Hospital of Strasbourg, Strasbourg, and the University Hospital of Besançon (Saleh, Delbosc, Montard), University of Franche-Comté, Besancon, France
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McDonald S, Lethorn A, Loi C, Joll C, Driessen H, Heitz A. Determination of odour threshold concentration ranges for some disinfectants and disinfection by-products for an Australian panel. Water Sci Technol 2009; 60:2493-2506. [PMID: 19923754 DOI: 10.2166/wst.2009.662] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Taste-and-odour complaints are a leading cause of consumer dissatisfaction with drinking water. The aim of this study was to determine odour threshold concentration ranges and descriptors, using a Western Australian odour panel, for chlorine, bromine, chlorine added to bromide ions, the four major regulated trihalomethanes (THMs), and combined THMs. An odour panel was established and trained to determine odour threshold concentration ranges for odorous compounds typically found in drinking water at 25 degrees C, using modified flavour profile analysis (FPA) techniques. Bromine and chlorine had the same odour threshold concentration ranges and were both described as having a chlorinous odour by a majority of panellists, but the odour threshold concentration range of bromine expressed in free chlorine equivalents was lower that that of chlorine. It is likely that the free chlorine equivalent residuals measured in many parts of distribution systems in Western Australia are comprised of some portion of bromine and that bromine has the potential to cause chlorinous odours at a lower free chlorine equivalent concentration than chlorine itself. In fact, bromine is the likely cause of any chlorinous odours in Western Australian distributed waters when the free chlorine equivalent concentration is between 0.04 and 0.1 mg L(-1). Odour threshold concentrations for the four individual THMs ranged from 0.06-0.16 mg L(-1), and the odour threshold concentration range was 0.10 + or - 0.09 mg L(-1) when the four THMs were combined (in equal mass concentrations). These concentrations are below the maximum guideline value for total THM concentration in Australia so odours from these compounds may possibly be observed in distributed waters. However, while the presence of THMs may contribute to any sweet/fragrant/floral and chemical/hydrocarbon odours in local drinking waters, the THMs are unlikely to contribute to chlorinous odours.
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Affiliation(s)
- S McDonald
- Curtin Water Quality Research Centre (CWQRC), Department of Applied Chemistry, Curtin University of Technology, GPO Box U1987, Perth, WA 6845, Australia.
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Busetti F, Heitz A, Cuomo M, Badoer S, Traverso P. Determination of sixteen polycyclic aromatic hydrocarbons in aqueous and solid samples from an Italian wastewater treatment plant. J Chromatogr A 2005; 1102:104-15. [PMID: 16256127 DOI: 10.1016/j.chroma.2005.10.013] [Citation(s) in RCA: 174] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2005] [Revised: 09/26/2005] [Accepted: 10/11/2005] [Indexed: 11/26/2022]
Abstract
A robust procedure for the determination of 16 US EPA PAHs in both aqueous (e.g. wastewaters, industrial discharges, treated effluents) and solid samples (e.g. suspended solids and sludge) from a wastewater treatment plant (WWTP) is presented. Recovery experiments using different percentages of organic modifier, sorbents and eluting solvent mixtures were carried out in Milli-Q water (1000 mL) spiked with a mixture of the PAH analytes (100 ng/L of each analyte). The solid phase extraction (SPE) procedures applied to spiked waste water samples (1000 mL; 100 ng/L spiking level) permitted simultaneous recovery of all the 16PAHs with yields >70% (6-13% RSD). SPE clean up procedures applied to sewage and stabilized sludge extracts, showed percent recoveries in the range 73-92% (7-13% RSD) and 71-89% (7-12% RSD), respectively. The methods were used for the determination of PAHs in aqueous and solid samples from the WWTP of Fusina (Venice, Italy). Mean concentrations, as the sum of the 16PAHs in aqueous and suspended solid samples, were found to be approx. in the 1.12-4.62 microg/L range. Sewage and stabilized sludge samples contained mean PAH concentrations, as sum of 16 compounds, in the concentration range of 1.44-1.26 mg/kg, respectively. Extraction and clean up procedures for sludge samples were validated using EPA certified reference material IRM-104 (CRM No. 912). Instrumental analyses were performed by coupling HPLC with UV-diode array detection (UV-DAD) and fluorescence detection (FLD).
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Affiliation(s)
- F Busetti
- Department of Applied Chemistry, Curtin University, GPO Box U1987 Perth, Western Australia 6845, Australia.
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Aleil B, Ravanat C, Cazenave JP, Rochoux G, Heitz A, Gachet C. Flow cytometric analysis of intraplatelet VASP phosphorylation for the detection of clopidogrel resistance in patients with ischemic cardiovascular diseases. J Thromb Haemost 2005; 3:85-92. [PMID: 15634270 DOI: 10.1111/j.1538-7836.2004.01063.x] [Citation(s) in RCA: 296] [Impact Index Per Article: 15.6] [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: 12/22/2022]
Abstract
Interindividual variability of the inhibitory effect of clopidogrel on platelet functions leading to clopidogrel resistance has been described in some patients with ischemic cardiovascular disease. A reliable laboratory test is therefore needed to identify patients insufficiently protected by this antiplatelet treatment. The phosphorylation of vasodilator-stimulated phosphoprotein (VASP), an intraplatelet actin regulatory protein, is dependent on the level of activation of the platelet P2Y12 receptor, which is targeted by clopidogrel. The aim of this study was to use a flow cytometric VASP phosphorylation assay to evaluate the efficacy of clopidogrel therapy. The platelet reactivity index (PRI), expressed as a percentage, is the difference in VASP fluorescence intensity between resting (+PGE1) and activated (+ADP) platelets. In vitro, the PRI was strongly correlated with the inhibition of platelet aggregation induced by specific blockade of the P2Y12 receptor by the competitive antagonist AR-C69931MX (R = 0.72, P < 0.0001). Ex vivo, the PRI was 78.3 +/- 4.6% in 47 healthy donors, 79.0 +/- 4.1% in 34 patients not receiving clopidogrel and 61.1 +/- 17.0% in 33 patients treated with clopidogrel (P < 0.0001). In the clopidogrel group, the PRI values were widely dispersed (from 6.6 to 85.8%) and more than 30% of these patients had a PRI equivalent of values in patients not receiving clopidogrel. The flow cytometric analysis of VASP phosphorylation seems to be a suitable test to evaluate the efficacy of clopidogrel treatment. This assay demonstrated a wide interindividual variability of the inhibitory response of platelets to clopidogrel and showed that one-third of the patients treated appeared to be 'unprotected' by this therapy.
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Affiliation(s)
- B Aleil
- Institut National de la Santé et de la Recherche Médicale U.311, Etablissement Français du Sang, Alsace, Strasbourg, France
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Todd JA, Jackson JBC, Johnson KG, Fortunato HM, Heitz A, Alvarez M, Jung P. The ecology of extinction: molluscan feeding and faunal turnover in the Caribbean Neogene. Proc Biol Sci 2002; 269:571-7. [PMID: 11916472 PMCID: PMC1690932 DOI: 10.1098/rspb.2001.1923] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Molluscan faunal turnover in the Plio-Pleistocene of the tropical western Atlantic has been attributed to drops in temperature or primary productivity, but these competing hypotheses have not been assessed ecologically. To test these alternatives, we compiled data on changing molluscan life habits and trophic composition over 12 million years derived from 463 newly made collections from the southwestern Caribbean. Shelf ecosystems have altered markedly in trophic structure since the Late Pliocene. Predatory gastropods and suspension-feeding bivalves declined significantly in abundance, but not in diversity, and reef-dwellers became common. By contrast, all other ecological life habits remained remarkably stable. Food-web changes strongly support the hypothesis that declining regional nutrient supply had an increasing impact on regional macroecology, culminating in a faunal turnover.
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Affiliation(s)
- J A Todd
- Department of Palaeontology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK.
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Heitz A, Hernandez JF, Gagnon J, Hong TT, Pham TT, Nguyen TM, Le-Nguyen D, Chiche L. Solution structure of the squash trypsin inhibitor MCoTI-II. A new family for cyclic knottins. Biochemistry 2001; 40:7973-83. [PMID: 11434766 DOI: 10.1021/bi0106639] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The "knottin" fold is a stable cysteine-rich scaffold, in which one disulfide crosses the macrocycle made by two other disulfides and the connecting backbone segments. This scaffold is found in several protein families with no evolutionary relationships. In the past few years, several homologous peptides from the Rubiaceae and Violaceae families were shown to define a new structural family based on macrocyclic knottin fold. We recently isolated from Momordica cochinchinensis seeds the first known macrocyclic squash trypsin inhibitors. These compounds are the first members of a new family of cyclic knottins. In this paper, we present NMR structural studies of one of them, MCoTI-II, and of a beta-Asp rearranged form, MCoTI-IIb. Both compounds display similar and well-defined conformations. These cyclic squash inhibitors share a similar conformation with noncyclic squash inhibitors such as CPTI-II, and it is postulated that the main effect of the cyclization is a reduced sensitivity to exo-proteases. On the contrary, clear differences were detected with the three-dimensional structures of other known cyclic knottins, i.e., kalata B1 or circulin A. The two-disulfide cystine-stabilized beta-sheet motif [Heitz et al. (1999) Biochemistry 38, 10615-10625] is conserved in the two families, whereas in the C-to-N linker, one disulfide bridge and one loop are differently located. The molecular surface of MCoTI-II is almost entirely charged in contrast to circulin A that displays a well-marked amphiphilic character. These differences might explain why the isolated macrocyclic squash inhibitors from M. cochinchinensis display no significant antibacterial activity, whereas circulins and kalata B1 do.
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Affiliation(s)
- A Heitz
- Centre de Biochimie Structurale, UMR5048 CNRS-Université Montpellier I, UMR554 INSERM-Université Montpellier I, Faculté de pharmacie, 15 avenue Charles Flahault, 34060 Montpellier, France
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Franzmann PD, Heitz A, Zappia LR, Wajon JE, Xanthis K. The formation of malodorous dimethyl oligosulphides in treated groundwater: the role of biofilms and potential precursors. Water Res 2001; 35:1730-1738. [PMID: 11329675 DOI: 10.1016/s0043-1354(00)00425-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Water distributed from the Wanneroo Groundwater Treatment Plant intermittently contains dimethyl trisulphide (DMTS). The compound is responsible for a "swampy odour" in the water. DMTS production from potential precursors was insignificant in the absence of biofilms when compared with DMTS production from precursors in the presence of biofilms in a biofilm reactor. Greatest dimethyl disulphide (DMDS) and DMTS production (> 3000 ng L-1 DMTS) occurred in the reactors when supplied with methane thio-containing compounds, such as methionine, S-methyl cysteine and methyl-3-(methylmercapto)-propionate. Abiotic DMTS production from oligosulphides also occurred through the addition of the methylating agents, methyl iodide or methyl-p-toluene sulphonate. Significant DMTS production also occurred with Wanneroo water that contained added omega-thio-containing compounds such as cysteine (1400 ng L-1 DMTS), and 3-mercaptopropionate (210 ng L-1). Biomethylation, a ubiquitous response by microorganisms for the detoxification of toxic compounds, generated DMDS/TS from biofilm oligosulphides. Biofilms exposed to the toxic compounds selenate or 2,4,6-trichlorophenol methylated oligosulphides in addition to the toxins. Sodium sulphide also stimulated DMTS production. Easily Biodegradable Dissolved Organic Carbon (BDOC) probably contributed indirectly to DMTS production by the biofilms, although whether this was a result of its stimulation of greater microbial activity or consumption of oxygen, or both, remains unresolved. Stagnation of water in the biofilm reactors also increased DMTS production, which was concomitant with depletion of oxygen concentrations in the bulk water. Many processes, such as degradation of methane thio-containing compounds, methylation of sulphides and oligosulphides, and changes in contributions of different metabolic pathways upon depletion of oxygen concentrations upon water stagnation, probably contribute simultaneously to "swampy odour" production in the distribution system.
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Affiliation(s)
- P D Franzmann
- CSIRO Land and Water, Floreat Park, WA 6016, Australia.
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15
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Abstract
The primary amphipathic peptide Ac-Met-Gly-Leu-Gly-Leu-Trp-Leu-Leu-Val-Leu10-Ala-Ala-Ala-Leu-Gln-Gly-Ala-Lys-Lys-Lys20-Arg-Lys-Val-NH-CH2-CH2-SH called SPM was able to induce formation of ion channels into planar lipid bilayers with main conductance values of 75 and 950 pS in 1 M KCl. The 75 pS value can be attributed to an aggregate composed of five monomers since the corresponding five-unit bundle (5-SPM) also presented a 70 pS channels under the same conditions. The upper 950 pS level would be generated by a hexameric aggregate. Ion channels induced by both SPM and its pentameric bundle are slightly cation selective but not voltage-dependent. The structural studies showed that the SPM and 5-SPM possess mainly an alpha-helical structure (approximately 40%) and are strongly embedded in the bilayer. This behaviour and the strong hydrophobic interactions occurring between helices in the bundle induce a strong stabilization of 5-SPM in the bilayer and would be responsible for the stepwise current fluctuations observed during the incorporation of 5-SPM into the membrane.
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Affiliation(s)
- E Dé
- UMR 6522 CNRS, IFRMP 23, Faculté des Sciences, Mont-Saint-Aignan, France
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16
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Morris MC, Heitz A, Mery J, Heitz F, Divita G. An essential phosphorylation-site domain of human cdc25C interacts with both 14-3-3 and cyclins. J Biol Chem 2000; 275:28849-57. [PMID: 10864927 DOI: 10.1074/jbc.m002942200] [Citation(s) in RCA: 30] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human cdc25C is a dual-specificity phosphatase involved in the regulation of cell cycle progression in both unperturbed cells and in cells subject to DNA damage or replication checkpoints. In this study, we describe the structure-function relationship of an essential domain of human cdc25C that interacts with 14-3-3 proteins. We show that this domain is a bi-functional interactive motif that interacts with cyclins primarily through their P-box motif in addition to 14-3-3 proteins. Characterization of the structural features of this domain by NMR and circular dichroism reveals two distinct alpha helical moieties interconnected by a loop carrying the 14-3-3 binding site. Moreover, the helical folding is induced upon binding to 14-3-3, suggestive of a conformational regulation of this domain of cdc25C through interactions with partner proteins in vivo. Combining our structural and biochemical data, we propose a detailed model of the molecular mechanism of cdc25C regulation by differential association with 14-3-3 and cdc2-cyclin B.
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Affiliation(s)
- M C Morris
- The Scripps Research Institute, Department of Molecular Biology, La Jolla, California 92037, USA
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17
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Abstract
The two major caffeoylquinic acids, 3,5-di-O-caffeoylquinic acid and 1,5-di-O-caffeoylquinic acid, were new-isolated from the flowering tops of Artemisia vulgaris (yield 2.0% and 0.3% on dry weight, respectively) and characterized by spectroscopic analysis.
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Affiliation(s)
- A Carnat
- Laboratoire de Pharmacognosie et Phytothérapie, Faculté de Pharmacie, Université d'Auvergne, 28 place Henri Dunant, F-63000 Clermont-Ferrand, France
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18
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Abstract
Quercetin 3-O-alpha-L-arabinopyranoside (1) was isolated from the aerial parts of Alchemilla xanthochlora and characterized by spectroscopic analysis.
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Affiliation(s)
- D Fraisse
- Laboratoire de Pharmacognosie et Phytothérapie, Faculté de Pharmacie, Université d'Auvergne, 28 place Henri Dunant, F-63000 Clermont-Ferrand, France
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19
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Cristau M, Devin C, Oiry C, Chaloin O, Amblard M, Bernad N, Heitz A, Fehrentz JA, Martinez J. Synthesis and biological evaluation of bombesin constrained analogues. J Med Chem 2000; 43:2356-61. [PMID: 10882361 DOI: 10.1021/jm990942i] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [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: 11/28/2022]
Abstract
Analogues of bombesin which incorporate dipeptide or turn mimetics have been synthesized. One of them (compound 11) containing a seven-membered lactam ring revealed a good affinity for GRP/BN receptors on rat pancreatic acini (K(i) value of 1.7 +/- 0.4 nM) and on Swiss 3T3 cells (K(i) value of 1.0 +/- 0.2 nM). On the basis of this observation, antagonists containing the same dipeptide mimic were obtained by modification of the C-terminal part of the bombesin analogues. The most potent constrained compounds (15 and 17) were able to antagonize 1 nM bombesin-stimulated amylase secretion from rat pancreatic acini with high potency (K(i) = 21 +/- 3 and 3.3 +/- 1.0 nM, respectively) and 10(-7) M bombesin-stimulated ¿(3)Hthymidine incorporation into Swiss 3T3 cells (K(i) = 7.8 +/- 2. 0 and 0.5 +/- 0.1 nM, respectively).
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Affiliation(s)
- M Cristau
- Laboratoire des Amino-acides, Peptides et Protéines and Centre de Biochimie Structurale, Faculté de Pharmacie, UMR 5810, CNRS-Universités Montpellier I & II, 15 avenue Charles Flahault, 34060 Montpellier, Cédex 2, France
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20
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Hernandez JF, Gagnon J, Chiche L, Nguyen TM, Andrieu JP, Heitz A, Trinh Hong T, Pham TT, Le Nguyen D. Squash trypsin inhibitors from Momordica cochinchinensis exhibit an atypical macrocyclic structure. Biochemistry 2000; 39:5722-30. [PMID: 10801322 DOI: 10.1021/bi9929756] [Citation(s) in RCA: 280] [Impact Index Per Article: 11.7] [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: 11/28/2022]
Abstract
Three trypsin inhibitors (TIs), from the seeds of the squash Momordica cochinchinensis (MCo), have been isolated and purified using gel filtration, ion exchange chromatography, and reverse-phase HPLC. Their sequences could be determined only after proteolytic cleavages. In the case of MCoTI-I and -II, it was shown that their polypeptide backbones are cyclic, a structure that has never been described in squash TIs. They contain 34 amino acid residues with 3 disulfide bridges and measured molecular masses of 3453.0 and 3480.7, respectively. They are the largest known macrocyclic peptides containing disulfide bridges. Their sequences show strong homology to other squash TIs, suggesting a similar three-dimensional structure and an analogous mechanism of action. A model of MCoTI-II was constructed by analogy to the crystal structure of the complex between bovine trypsin and CMTI-I, indicating that the linker connecting the two termini is flexible and does not impose significant geometrical constraints. This flexibility allows an Asp-Gly peptide bond rearrangement to occur in this region, giving rise to two isoforms of MCoTI-II. Although the importance of cyclization is not clear, it might confer increased stability and resistance to proteolysis. A minor species, MCoTI-III, was also characterized as containing 30 amino acid residues with a molecular mass of 3379.6. This component possesses a linear backbone with a blocked N-terminus. MCoTIs represent interesting candidates for drug design, either by changing their specificity of inhibition or by using their structure as natural scaffolds bearing new binding activities.
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Affiliation(s)
- J F Hernandez
- Institut de Biologie Structurale Jean-Pierre Ebel (CEA-CNRS), 41, rue Jules Horowitz, 38027 Grenoble Cedex 1, France
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21
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Abstract
Luteolin 3'-O-beta-D-glucuronide (1) was isolated from the leaves of Melissa officinalis subsp. officinalis and characterized by spectroscopic analysis.
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Affiliation(s)
- A Heitz
- CBS, CNRS INSERM, Faculté de Pharmacie, Université de Montpellier I, 15 avenue Charles Flahault, F-34060, Montpellier, France
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22
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Heitz A, Le-Nguyen D, Chiche L. Min-21 and min-23, the smallest peptides that fold like a cystine-stabilized beta-sheet motif: design, solution structure, and thermal stability. Biochemistry 1999; 38:10615-25. [PMID: 10441159 DOI: 10.1021/bi990821k] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Small disulfide-rich proteins provide examples of simple and stable scaffolds for design purposes. The cystine-stabilized beta-sheet (CSB) motif is one such elementary structural motif and is found in many protein families with no evolutionary relationships. In this paper, we present NMR structural studies and stability measurements of two short peptides of 21 and 23 residues that correspond to the isolated CSB motif taken from a 28-residue squash trypsin inhibitor. The two peptides contain two disulfide bridges instead of three for the parent protein, but were shown to fold in a native-like fashion, indicating that the CSB motif can be considered an autonomous folding unit. The 23-residue peptide was truncated at the N-terminus. It has a well-defined conformation close to that of the parent squash inhibitor, and although less stable than the native protein, it still exhibits a high T(m) of about 100 degrees C. We suggest that this peptide is a very good starting building block for engineering new bioactive molecules by grafting different active or recognition sites onto it. The 21-residue peptide was further shortened by removing two residues in the loop connecting the second and third cysteines. This peptide exhibited a less well-defined conformation and is less stable by about 1 kcal mol(-)(1), but it might be useful if a higher flexibility is desired. The lower stability of the 21-residue peptide is supposed to result from inadequate lengths of segments connecting the first three cysteines, thus providing new insights into the structural determinants of the CSB motif.
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Affiliation(s)
- A Heitz
- Centre de Biochimie Structurale, Faculté de pharmacie, UMR9955 CNRS-INSERM-Université Montpellier I, France
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23
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Abstract
We have designed, synthesized and purified a 51 amino acid peptide derived from an essential domain of human cdc25C phosphatase. In vivo, differential phosphorylation of this domain regulates either the induction of mitotic processes, or the checkpoint arrest of eukaryotic cells in response to DNA damage. Peptide synthesis was achieved using the stepwise Fmoc strategy and resulted in an important yield of highly pure peptide. The final peptide was identified by amino acid analysis, electrospray mass spectrometry and nuclear magnetic resonance, which revealed that one of the two methionines within the peptide was oxidized into its sulphoxide derivative We investigated whether this 51 amino acid peptide folded into secondary structures in solution by circular dichroism and observed the formation of alpha helices in TFE. Finally, we verified that this peptide could bind to its biologically relevant 14-3-3 partner in vitro by fluorescence spectroscopy.
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Affiliation(s)
- M C Morris
- CRBM, CNRS-UPR 1086, Montpellier, France
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24
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Abstract
Bombesin pseudo-peptide analogues containing a hydroxamide function on the C-terminal part of the molecule, e.g. H-D-Phe-Gln-Trp-Ala-Val-Gly-His-Leu-NHOBzl 1 and H-D-Phe-Gln-Trp-Ala-Val-Gly-His-Leu-NHOH 2 were synthesized. These compounds were tested for their ability to recognize the bombesin receptor on rat pancreatic acini and on 3T3 cells, to stimulate (i) amylase secretion from rat pancreatic acini and (ii) accumulation of tritiated thymidine in 3T3 cells. Compounds 1 and 2 were able to recognize bombesin receptors on both models with high affinity (Ki = 7 +/- 2 and 5.8 +/- 0.9 nM on rat pancreatic acini, and Ki = 4.1 +/- 1.2 and 7.7 +/- 1.9 nM on 3T3 cells, respectively). Interestingly, compound 1 behaved as a potent agonist in stimulating amylase secretion from rat pancreatic acini and is able to stimulate thymidine accumulation in 3T3 cells, while compound 2 was able to potently antagonize bombesin-stimulated amylase secretion (Ki = 22 +/- 5 nM) in rat pancreatic acini and had no proper effect on 3T3 cells; however, it was able to inhibit bombesin-stimulated thymidine accumulation in 3T3 cells with high potency (Ki = 1.6 +/- 0.6 nM).
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Affiliation(s)
- C Devin
- Laboratoire des Amino-acides, Peptides et Protéines, Faculté de Pharmacie, Montpellier, France
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25
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Vidal P, Chaloin L, Heitz A, Van Mau N, Méry J, Divita G, Heitz F. Interactions of primary amphipathic vector peptides with membranes. Conformational consequences and influence on cellular localization. J Membr Biol 1998; 162:259-64. [PMID: 9543498 DOI: 10.1007/s002329900363] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The conformations of two peptides produced by the combinations of a nuclear localization sequence and a sequence issued from the fusion protein gp41 of HIV 1 have been analyzed both in solution and in membranes or in membrane mimicking environments. Both are shown to be nonordered in water, alpha-helical when incorporated into SDS micelles where the helical domain concerns the hydrophobic part of the peptides. Interactions with lipids induce the formation of beta-sheet and the lipid-peptide interactions are governed by the nature of the lipid polar headgroups. A monolayer study shows that replacement of the sequence separating the two sequences with an arginine favors the lipid-peptide interactions which may contribute to the understanding of the different, nuclear and membrane associated, cellular localizations of the peptides.
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Affiliation(s)
- P Vidal
- CRBM-CNRS (UPR 1086), 1919, Route de Mende, F. 34293 Montpellier Cedex 5, France
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26
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Carnat AP, Carnat A, Fraisse D, Lamaison JL, Heitz A, Wylde R, Teulade JC. Violarvensin, a new flavone di-C-glycoside from Viola arvensis. J Nat Prod 1998; 61:272-274. [PMID: 9548860 DOI: 10.1021/np9701485] [Citation(s) in RCA: 27] [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] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A new flavonoid di-C-glycoside, violarvensin (1), was isolated from the aerial parts of Viola arvensis, together with the known derivative violanthin (2). The structure of 1 was established as apigenin-6-C-beta-D-glucopyranosyl-8-C-beta-D-6-deoxygulopyrano side by spectral analysis.
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Affiliation(s)
- A P Carnat
- Laboratoire de Pharmacognosie et Phytothérapie, Faculté de Pharmacie, Université d'Auvergne, Clermont-Ferrand, France
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27
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Affiliation(s)
- J. A. Fehrentz
- Laboratoire des Amino-acides, Peptides et Protéines (LAPP), ESA 5075, CNRS-Universités Montpellier I & II, Faculté de Pharmacie, 15 av. C. Flahault, 34060 Montpellier, and UMR 9955 CNRS, Faculté de Pharmacie, Montpellier, France
| | - M. Paris
- Laboratoire des Amino-acides, Peptides et Protéines (LAPP), ESA 5075, CNRS-Universités Montpellier I & II, Faculté de Pharmacie, 15 av. C. Flahault, 34060 Montpellier, and UMR 9955 CNRS, Faculté de Pharmacie, Montpellier, France
| | - A. Heitz
- Laboratoire des Amino-acides, Peptides et Protéines (LAPP), ESA 5075, CNRS-Universités Montpellier I & II, Faculté de Pharmacie, 15 av. C. Flahault, 34060 Montpellier, and UMR 9955 CNRS, Faculté de Pharmacie, Montpellier, France
| | - J. Velek
- Laboratoire des Amino-acides, Peptides et Protéines (LAPP), ESA 5075, CNRS-Universités Montpellier I & II, Faculté de Pharmacie, 15 av. C. Flahault, 34060 Montpellier, and UMR 9955 CNRS, Faculté de Pharmacie, Montpellier, France
| | - F. Winternitz
- Laboratoire des Amino-acides, Peptides et Protéines (LAPP), ESA 5075, CNRS-Universités Montpellier I & II, Faculté de Pharmacie, 15 av. C. Flahault, 34060 Montpellier, and UMR 9955 CNRS, Faculté de Pharmacie, Montpellier, France
| | - J. Martinez
- Laboratoire des Amino-acides, Peptides et Protéines (LAPP), ESA 5075, CNRS-Universités Montpellier I & II, Faculté de Pharmacie, 15 av. C. Flahault, 34060 Montpellier, and UMR 9955 CNRS, Faculté de Pharmacie, Montpellier, France
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28
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Chaloin L, Vidal P, Heitz A, Van Mau N, Méry J, Divita G, Heitz F. Conformations of primary amphipathic carrier peptides in membrane mimicking environments. Biochemistry 1997; 36:11179-87. [PMID: 9287160 DOI: 10.1021/bi9708491] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Two peptides designed for drug delivery were generated by the combination of a signal peptide with a nuclear localization sequence and are shown to facilitate the cellular internalization of small molecules which are covalently linked to these peptides. In order to understand the mechanism of internalization, the conformations of the peptides were investigated through different approaches both in solution and in membrane-mimicking environments. These peptides are highly versatile and adopt different conformational states depending on their environment. While in a disordered form in water, they adopt an alpha-helical structure in TFE and in the presence of micelles of SDS or DPC. The structured domain encompasses the hydrophobic part of the peptides, whereas the charged C-termini remain unstructured. In contrast, in the presence of lipids and whatever the nature of the phosphate headgroup, the two peptides mainly adopt an antiparallel beta-sheet form and embed in the lipidic cores. This result suggests that the beta-sheet is responsible for the translocation through the cellular membranes but also questions the conformational state of signal peptides when associated to hydrophilic sequences.
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Affiliation(s)
- L Chaloin
- CRBM-CNRS (ERS 0155), Route de Mende, BP 5051, F. 34033 Montpellier Cedex, France
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29
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Heitz A, Chiche L, Le-Nguyen D, Castro B. Folding of the squash trypsin inhibitor EETI II. Evidence of native and non-native local structural preferences in a linear analogue. Eur J Biochem 1995; 233:837-46. [PMID: 8521849 DOI: 10.1111/j.1432-1033.1995.837_3.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A peptide, corresponding to the entire sequence of the squash trypsin inhibitor EETI II (Ecballium elaterium trypsin inhibitor) in which the six cysteines, engaged in three disulphide bridges in native EETI II, have been replaced by six serines, has been synthesised. CD, Fourier-transform infrared spectroscopy (FTIR) and 1H-NMR studies of this peptide revealed that some secondary structures present in native EETI II are still populated in the absence of disulphide bonds. Native-like secondary structures were observed for segments 10-15 (helix), 16-19 and 22-25 (reverse turns) but no native tertiary interaction was detected. However, a non-native local interaction between the aromatic ring of Phe26 and the amide group of Gly28 was observed. It is hypothesised that the 10-15, 16-19 and 22-25 native-like local conformations could play a major role in the early folding of EETI II.
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Affiliation(s)
- A Heitz
- Centre de Biochimie Structurale, CNRS-INSERM, Faculté de Pharmacie, Université Montpellier I, Montpellier, France
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30
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Carnat A, Carnat AP, Chavignon O, Heitz A, Wylde R, Lamaison JL. Luteolin 7-diglucuronide, the major flavonoid compound from Aloysia triphylla and Verbena officinalis. Planta Med 1995; 61:490. [PMID: 7480218 DOI: 10.1055/s-2006-958152] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Affiliation(s)
- A Carnat
- Laboratoire de Pharmacognosie et Phytothérapie, Faculté de Pharmacie, Université d'Auvergne, Clermont-Ferrand, France
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31
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Karmann H, Mrosovsky N, Heitz A, Le Maho Y. Protein sparing on very low calorie diets: ground squirrels succeed where obese people fail. Int J Obes Relat Metab Disord 1994; 18:351-353. [PMID: 8061729] [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: 05/22/2023]
Abstract
During seasonal cycles in ground squirrels, as in many other species, there are periods of spontaneous loss of appetite, very low calorie intake and a 30% loss in body mass. Measurements of nitrogen balance during early and later stages of the mass loss phase of the cycle (-1.2 +/- 6.7 and +13.1 +/- 8.8 mg/24 h, respectively) showed a total sparing of protein, indicating a selective use of fat. However, when no food at all was available, nitrogen balance was negative (-45 +/- 5 mg/24 h). Provided that they have access to some food, ground squirrels are therefore able to compensate for any protein utilization, while at the same time selectively losing large amounts of fat. It appears that a factor related to spontaneous reduction in food intake enables these animals to achieve the total sparing of protein that eludes dieting humans on comparably low caloric intakes.
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Affiliation(s)
- H Karmann
- Centre d'Ecologie et Physiologie Energétiques, Centre National de la Recherche Scientifique, Strasburg, France
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32
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Affiliation(s)
- J Koudou
- Laboratoire de Chimie des Substances Naturelles, Faculté des Sciences et Technologie, BP 908, Bangui, République Centre Africaine
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33
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Abstract
Cancer cachexia is among the most dramatic situations of depletion in body energy reserves. To ascertain whether the pattern of body composition alteration during tumour development is influenced by aging as in uncomplicated starvation, we compared the difference of body composition between Yoshida sarcoma bearing rats and young (200 g, 7 weeks) and adult (400 g, 13 weeks) control rats. After the same duration of tumour bearing, mass and composition of tumours were similar in adult and young rats, indicating that they are independent of host age. Food intake decreased to a remarkably similar value in both young and adults. Body water content was elevated in hosts of both ages. The relative deficit of body lipid vs controls was similar for both, the absolute lipid deficit being therefore larger in adult than in young tumour-bearing rats (14.3 +/- 4.4 g vs 6.8 +/- 0.9 g; P < 0.01). In contrast, there was a relatively larger deficit of body protein in young rats. Paradoxically, these rats still maintained a positive nitrogen balance whereas this balance was negative in adult tumour-bearing rats. In conclusion, as previously shown in uncomplicated undernutrition, the anorexia induced by Yoshida sarcoma development is still associated with some protein accretion in young rats whereas cachexia develops in adults.
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Affiliation(s)
- H Oudart
- Centre d'Ecologie et de Physiologie Energétiques, CNRS, Strasbourg, France
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34
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Chiche L, Heitz A, Padilla A, Le-Nguyen D, Castro B. Solution conformation of a synthetic bis-headed inhibitor of trypsin and carboxypeptidase A: new structural alignment between the squash inhibitors and the potato carboxypeptidase inhibitor. Protein Eng 1993; 6:675-82. [PMID: 8248090 DOI: 10.1093/protein/6.7.675] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The trypsin carboxypeptidase peptide inhibitor (TCPI) which inhibits both trypsin and carboxypeptidase A has been chemically engineered by modification of the Ecballium elaterium trypsin inhibitor II (EETI-II). The solution conformation of TCPI, studied by two-dimensional nuclear magnetic resonance, was shown to be very close to those of squash inhibitors. Only limited deviations of the trypsin binding loop compared to its location in the EETI-II/trypsin complex were detected. It was also shown that the position of the C-terminal tail did not significantly change from the position observed in the complex between carboxypeptidase A and the potato carboxypeptidase inhibitor (PCI). The conformation of TCPI was carefully compared with the PCI one and a new structural alignment between the two microproteins is proposed. This alignment points out the very good conservation in the two inhibitors of a subdomain comprising segments 7-15, 19-22 and 25-28. Most importantly, the 2-19 disulfide bridge of TCPI was not structurally conserved in PCI and appeared to be rather unimportant for the early folding process of these molecules. This result agrees with the recent observation that the 2-19 bridge is the last to be formed in the folding of the squash inhibitor EETI-II and suggests that this is also the case during the folding of the potato carboxypeptidase inhibitor.
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Affiliation(s)
- L Chiche
- Centre de Biochimie Structurale, Faculté de Pharmacie, Montpellier, France
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35
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Oyono-Enguelle S, Heitz A, Marbach J, Ott C, Pape A, Freund H. Heat stress does not modify lactate exchange and removal abilities during recovery from short exercise. J Appl Physiol (1985) 1993; 74:1248-55. [PMID: 8482665 DOI: 10.1152/jappl.1993.74.3.1248] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Arterial and femoral venous lactate concentrations were measured before, during, and after short intermittent exercise (55-118% of maximal O2 consumption) in thermoneutral (N, 25 degrees C, 10.5 Torr) and hot (H, 45 degrees C, 17.5 Torr) conditions. The thermal load induced significantly higher heart rate and rectal temperature in H relative to N. All the arterial lactate (La) recovery curves were fitted to an equation containing two exponential time functions of the form La(t) = La(0) + A1a(1 - e-gamma 1at) + A2a(1 - e-gamma 2at) where the velocity constants gamma 1a and gamma 2a are the body's overall ability to exchange and remove lactate after exercise, respectively, and t is time. There was no significant difference in these constants, regardless of thermal conditions. The arterial lactate concentration at the end of exercise, the peak lactate concentration during recovery, the amplitudes A1a and A2a of the biexponential function, and the arteriofemoral venous lactate concentration difference during recovery were not significantly different in H relative to N. However, measured and computed arterial lactate concentrations during recovery, especially at the end of the tests, were higher in H (P < 0.04). The more elevated lactate concentrations in H at rest at the end of recovery denote a higher basal lactate production, and they were not due to muscle hypoxia.
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Affiliation(s)
- S Oyono-Enguelle
- Groupe de Recherche Activités Physiques et Sportives, Strasbourg, France
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36
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Le-Nguyen D, Heitz A, Chiche L, el Hajji M, Castro B. Characterization and 2D NMR study of the stable [9-21, 15-27] 2 disulfide intermediate in the folding of the 3 disulfide trypsin inhibitor EETI II. Protein Sci 1993; 2:165-74. [PMID: 8443596 PMCID: PMC2142350 DOI: 10.1002/pro.5560020205] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [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
The three disulfide Ecballium elaterium trypsin inhibitor II (EETI II) reduction with dithiothreitol (DTT) and reoxidation of the fully reduced derivative have been examined. A common stable intermediate has been observed for both processes. Isolation and sequencing of carboxymethylated material showed that the intermediate lacks the [2-19] bridge. The NMR study showed a very strong structural conservation as compared to the native EETI II, suggesting that the bridges are the [9-21] and [15-27] native ones. The differences occurred in sections 2-7 (containing the free cysteine 2 and the Arg 4-Ile 5 active site) and 19-21 (containing the second free cysteine). Distance geometry calculations and restrained molecular dynamics refinements were also in favor of a [9-21, 15-27] arrangement and resulted in a well-conserved (7-28) segment.
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37
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Cherel Y, Robin JP, Heitz A, Calgari C, Le Maho Y. Relationships between lipid availability and protein utilization during prolonged fasting. J Comp Physiol B 1992; 162:305-13. [PMID: 1506487 DOI: 10.1007/bf00260757] [Citation(s) in RCA: 106] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Mammals and birds adapt to prolonged fasting by mobilizing fat stores and minimizing protein loss. This strategy ends with an increase in protein utilization associated with behavioural changes promoting food foraging. Using the Zucker rat as a model, we have investigated the effect of severe obesity on this pattern of protein loss during long-term fasting. Two interactions between the initial adiposity and protein utilization were found. First, protein conservation was more effective in obese than in lean rats: fatty rats had a three times lower daily nitrogen excretion and proportion of energy expenditure deriving from proteins, and a lower daily protein loss in various muscles. This phase of protein sparing is moreover nine times longer in the fatty rats. Second, obese animals did not show the late increase in nitrogen excretion that occurred in their lean littermates. Total body protein loss during starvation was larger in fatty rats (57% versus 29%) and, accordingly, total protein loss was greater in their muscles. At the end of the experiment, lean and obese rats had lost 98% and 82%, respectively, of their initial lipid reserves, and fatty rats still had an obese body composition. These results support the hypothesis that in severely obese humans and animals a lethal cumulative protein loss is reached long before the exhaustion of fat stores, while the phase of protein conservation is still continuing. In contrast, in lean rats, survival of fasting seems to depend on the availability of lipid fuels.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- Y Cherel
- Laboratoire d'Etude des Régulations Physiologiques, associé à l'Université Louis Pasteur, Centre National de la Recherche Scientifique, Strasbourg, France
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38
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Rodriguez M, Heitz A, Martinez J. "Carba" peptide bond surrogates. Different approaches to Gly-psi(CH2-CH2)-D,L-Xaa pseudo-dipeptide units. Int J Pept Protein Res 1992; 39:273-7. [PMID: 1399267 DOI: 10.1111/j.1399-3011.1992.tb00800.x] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Racemic "carba" pseudo-dipeptide units such as Gly-psi(CH2-CH2)-D,L-Xaa were obtained either through the Horner-Emmons condensation of N-tert.-butyloxycarbonyl-beta alaninal with the appropriate substituted triethyl phosphonacetate, or from commercially available 3-carbethoxy-2-piperidone.
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Affiliation(s)
- M Rodriguez
- CCIPE, Faculty of Pharmacy, Montpellier, France
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39
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Freund H, Oyono-Enguéllé S, Heitz A, Ott C, Marbach J, Gartner M, Pape A. Comparative lactate kinetics after short and prolonged submaximal exercise. Int J Sports Med 1990; 11:284-8. [PMID: 2228357 DOI: 10.1055/s-2007-1024808] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Arterial blood lactate concentrations were determined in two groups of eleven males before, during and after near 2 W.kg body mass-1 bicycle exercise. One group of subjects cycled for 3 min, whereas the second group exercised for 60 min. All the lactate curves during recovery could be fitted to a bi-exponential time function consisting of a rapidly increasing and a slowly decreasing component. This typical evolution pattern indicates that the two-compartment model which has been proposed to represent the movements of lactate after short exercise applies also to recovery from prolonged exercise. Lengthening exercise duration decreased (respectively 10% and 28%) the value of both velocity constants of the fits to the lactate recovery curves, with the difference (28%) being statistically significant for the velocity constant describing the slowly decreasing part of the curves. This result indicates that extending exercise from 3 to 60 min impairs the ability to remove lactate after the exercise.
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Affiliation(s)
- H Freund
- Laboratoire de Pharmacologie Cellulaire et Moléculaire, Université Louis Pasteur Strasbourg, Illkirch-Graffenstaden, France
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40
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Le Nguyen D, Heitz A, Chiche L, Castro B, Boigegrain RA, Favel A, Coletti-Previero MA. Molecular recognition between serine proteases and new bioactive microproteins with a knotted structure. Biochimie 1990; 72:431-5. [PMID: 2124146 DOI: 10.1016/0300-9084(90)90067-q] [Citation(s) in RCA: 97] [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: 12/30/2022]
Abstract
Microproteins with proteinase inhibitory activity, 28 to 30 amino acids long, with 3 disulfide bridges have been isolated from Ecballium elaterium seeds. A peptide (EETI II) was isolated and behaved as a powerful trypsin inhibitor (Kd = 10(-11) to 10(-12) M). It was sequenced, chemically synthesized and the 3-D structure determined by 2-D 1H NMR. The information gained in the process enabled us to synthesize modified derivatives with inhibitory activity towards pancreatic elastase, chymotrypsin and human leucocyte elastase (Kd = 10(-7) to 10(-9) respectively). The most striking characteristic that appeared during the synthetic approach was the unfailing ability of the 28 amino acid peptides to refold and correctly close the 3 disulfide bridges, giving in each case an active compound. These disulfide bridges are assembled in a particular knotted structure, shared by few other bioactive peptides and called the 'knottin' structure. Molecular modeling of the peptide and a comparison with the other active molecules with similar topology allowed the synthesis of a chimaeric peptide, bearing 1 active site against a seryl-protease (trypsin), and 1 against a metallo-protease (carboxypeptidase A). The bis-headed peptide was able to inhibit both enzymes separately and concomitantly.
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Affiliation(s)
- D Le Nguyen
- Centre CNRS-INSERM de Pharmaco-Endocrinologie, Montpellier, France
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41
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Oyono-Enguelle S, Marbach J, Heitz A, Ott C, Gartner M, Pape A, Vollmer JC, Freund H. Lactate removal ability and graded exercise in humans. J Appl Physiol (1985) 1990; 68:905-11. [PMID: 2341356 DOI: 10.1152/jappl.1990.68.3.905] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Venous lactate concentrations of nine athletes were recorded every 5 s before, during, and after graded exercise beginning at a work rate of 0 W with an increase of 50 W every 4th min. The continuous model proposed by Hughson et al. (J. Appl. Physiol. 62: 1975-1981, 1987) was well fitted with the individual blood lactate concentration vs. work rate curves obtained during exercise. Time courses of lactate concentrations during recovery were accurately described by a sum of two exponential functions. Significant direct linear relationships were found between the velocity constant (gamma 2 nu) of the slowly decreasing exponential term of the recovery curves and the times into the exercise when a lactate concentration of 2.5 mmol/l was reached. There was a significant inverse correlation between gamma 2 nu and the rate of lactate increase during the last step of the exercise. In terms of the functional meaning given to gamma 2 nu, these relationships indicate that the shift to higher work rates of the increase of the blood lactate concentration during graded exercise in fit or trained athletes, when compared with less fit or untrained ones, is associated with a higher ability to remove lactate during the recovery. The results suggest that the lactate removal ability plays an important role in the evolution pattern of blood lactate concentrations during graded exercise.
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Affiliation(s)
- S Oyono-Enguelle
- Laboratoire de Physiologie Appliquée, Groupe de Recherche Activités Physiques et Sportives, Strasbourg, France
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42
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Oyono-Enguelle S, Heitz A, Marbach J, Ott C, Gartner M, Pape A, Vollmer JC, Freund H. Blood lactate during constant-load exercise at aerobic and anaerobic thresholds. Eur J Appl Physiol Occup Physiol 1990; 60:321-30. [PMID: 2369904 DOI: 10.1007/bf00713494] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Venous blood lactate concentrations [1ab] were measured every 30 s in five athletes performing prolonged exercise at three constant intensities: the aerobic threshold (Thaer), the anaerobic threshold (Than) and at a work rate (IWR) intermediate between Thaer and Than. Measurements of oxygen consumption (VO2) and heart rate (HR) were made every min. Most of the subjects maintained constant intensity exercise for 45 min at Thaer and IWR, but at Than none could exercise for more than 30 min. Relationships between variations in [1ab] and concomitant changes in VO2 or HR were not statistically significant. Depending on the exercise intensity (Thaer, IWR, or Than) several different patterns of change in [1ab] have been identified. Subjects did not necessarily show the same pattern at comparable exercise intensities. Averaging [1ab] as a function of relative exercise intensity masked spatial and temporal characteristics of individual curves so that a common pattern could not be discerned at any of the three exercise levels studied. The differences among the subjects are better described on individual [1ab] curves when sampling has been made at time intervals sufficiently small to resolve individual characteristics.
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Affiliation(s)
- S Oyono-Enguelle
- Centre de Recherches Nucléaires, IN2P3-CNRS/Université Louis Pasteur, Strasbourg, France
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43
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Heitz F, Kaddari F, Heitz A, Raniriseheno H, Lazaro R. Conformations, cation binding, and transmembrane ion transfer properties of a cyclooctapeptide built by an alternation of D and L residues. Int J Pept Protein Res 1989; 34:387-93. [PMID: 2482262 DOI: 10.1111/j.1399-3011.1989.tb00707.x] [Citation(s) in RCA: 5] [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: 01/01/2023]
Abstract
The conformations of a cyclic octapeptide built with an alternation of D and L residues are investigated on the basis of 1H n.m.r. and CD data. The cyclooctapeptide can form structures which are specific to the alternating D-L sequence. This peptide can form two types of complexes with cations (peptide 2-cation and peptide-cation complexes) and the binding with monovalent cation is weak. This peptide is able to induce transmembrane ion transfer through both a carrier mechanism and pore formation.
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Affiliation(s)
- F Heitz
- Laboratory of Polyphasic System Physiochemistry, UA 330, Montpellier, France
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44
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Aumelas A, Audousset-Puech MP, Heitz A, Bataille D, Martinez J. 1H n.m.r. conformational studies on the C-terminal octapeptide of oxyntomodulin, a beta-turn locked by a salt bridge. Int J Pept Protein Res 1989; 34:268-76. [PMID: 2599765 DOI: 10.1111/j.1399-3011.1989.tb01574.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The octapeptide Lys-Arg-Asn-Lys-Asn-Asn-Ile-Ala (Arg4 in the human sequence) is the C-terminal part of porcine oxyntomodulin, an endogeneous peptide which is a potent inhibitor of stimulated acid secretion. This octapeptide exhibits the whole range of biological activities of the parent hormone. In the present work we report an 1H n.m.r. investigation of the conformational properties of the octapeptides of pig and human sequences in dimethylsulfoxide-d6 (DMSO) solution. The various resonances were assigned on the basis of two-dimensional COSY and NOESY experiments. Other experiments such as (i) temperature and concentration dependence of the amide proton chemical shifts, (ii) effects of ionic strength, (iii) comparison of the spectra with different analogues, were performed. We showed that in DMSO, the conformation of the octapeptide is directly related to the ionisation state of the C-terminus carboxyl group of alanine. In carboxylic state, the peptide adopts an extended conformation, while in the carboxylate state the four last residues (Asn-Asn-Ile-Ala) are involved in a type II beta-turn structure probably locked by a salt bridge between the carboxyl group of Ala8 and the epsilon ammonium group of Lys4 (or the guanidinium group of Arg4). These observations provide an insight into the possible conformational tendencies of this peptide in biological media.
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Affiliation(s)
- A Aumelas
- Centre CNRS-INSERM of Pharmacology-Endocrinology, Montpellie, France
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45
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Heitz A, Chiche L, Le-Nguyen D, Castro B. 1H 2D NMR and distance geometry study of the folding of Ecballium elaterium trypsin inhibitor, a member of the squash inhibitors family. Biochemistry 1989; 28:2392-8. [PMID: 2730872 DOI: 10.1021/bi00432a009] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.2] [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: 01/02/2023]
Abstract
The solution conformation of synthetic Ecballium elaterium trypsin inhibitor II, a 28-residue peptide with 3 disulfide bridges, has been studied by 1H 2D NMR measurements. Secondary structure elements were determined: a miniantiparallel beta-sheet Met 7-Cys 9 and Gly 25-Cys 27, a beta-hairpin 20-28 with beta-turn 22-25, and two tight turns Asp 12-Cys 15 and Leu 16-Cys 19. A set of interproton distance restraints deduced from two-dimensional nuclear Overhauser enhancement spectra and 13 phi backbone torsion angles restraints were used as the basis of three-dimensional structure computations including disulfide bridges arrangement by using distance geometry calculations. Computations for the 15 possible S-S linkage combinations lead to the proposal of the array 2-19, 9-21, 15-27 as the most probable structure for EETI II.
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Affiliation(s)
- A Heitz
- Centre CNRS-INSERM de Pharmacologie-Endocrinologie, Montpellier, France
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46
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Freund H, Oyono-Enguelle S, Heitz A, Marbach J, Ott C, Gartner M. Effect of exercise duration on lactate kinetics after short muscular exercise. Eur J Appl Physiol Occup Physiol 1989; 58:534-42. [PMID: 2759080 DOI: 10.1007/bf02330709] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Arterial blood lactate concentrations were measured in six normal males before, during and after 3- and 6-min bicycle exercises performed at three different work rates. The lactate recovery curves were fitted to a bi-exponential time function consisting of a rapidly increasing and a slowly decreasing component, which supplied an accurate representation of the changes in lactate concentration. Variations in the parameters of this mathematical model have been studied as a function of the duration of exercise and of the work rate, showing a clear dependence on exercise duration such that increasing exercise length decreases the velocity constants of the fitted curves. In terms of the functional meaning which can be given to these constants, this result indicates that extending exercise duration from 3 to 6 min reduces the ability of the whole body to exchange and remove lactate. This effect did not qualitatively modify the one already described, which is due to increased work rates, but it shifted the ability to exchange and remove lactate towards lower values. The main conclusion of the study is that lactate kinetic data vary as a function of time during exercise. This inference must be accounted for in the interpretation of lactate data obtained during muscular exercise.
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Affiliation(s)
- H Freund
- Laboratoire de Physiologie Appliquée, Groupe de Recherche Activités Physiques et Sportives, Strasbourg, France
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47
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Oyono-Enguelle S, Gartner M, Marbach J, Heitz A, Ott C, Freund H. Comparison of arterial and venous blood lactate kinetics after short exercise. Int J Sports Med 1989; 10:16-24. [PMID: 2703280 DOI: 10.1055/s-2007-1024867] [Citation(s) in RCA: 21] [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: 01/02/2023]
Abstract
Seventeen healthy male volunteers participated in this study designed to compare arterial with both arterialized venous and venous lactate kinetics after short exercise. Blood samples drawn before, during, and after bicycle exercise were analyzed continuously for lactate. A mathematical function incorporating two exponential terms was fitted to the arterial, arterialized venous, and venous lactate recovery curves, and the parameters of the mathematical function were compared using a linear regression. All parameters measured on or fitted to the arterialized venous curves correlated well with the respective arterial data (correlation coefficient R = 0.82 to 0.99, P less than 0.001). Among the parameters obtained from the fit to the venous curves, only those describing lactate removal correlated closely with the arterial results. It is concluded that for lactate kinetic studies during recovery following short-term muscular exercise, the information obtained from arterialized venous blood is comparable to arterial blood, whereas the use of venous blood, from the sampling site in this study, appears suitable for determining only the parameters for lactate disappearance. These conclusions are illustrated by the comparison between arterial, arterialized venous, and venous parameters as a function of the work rate of the previously performed exercise.
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48
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Chiche L, Gaboriaud C, Heitz A, Mornon JP, Castro B, Kollman PA. Use of restrained molecular dynamics in water to determine three-dimensional protein structure: prediction of the three-dimensional structure of Ecballium elaterium trypsin inhibitor II. Proteins 1989; 6:405-17. [PMID: 2622910 DOI: 10.1002/prot.340060407] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Refinement of distance geometry (DG) structures of EETI-II (Heitz et al.: Biochemistry 28:2392-2398, 1989), a member of the squash family trypsin inhibitor, have been carried out by restrained molecular dynamics (RMD) in water. The resulting models show better side chain apolar/polar surface ratio and estimated solvation free energy than structures refined "in vacuo." The consistent lower values of residual NMR constraint violations, apolar/polar surface ratio, and solvation free energy for one of these refined structures allowed prediction of the 3D folding and disulfide connectivity of EETI-II. Except for the few first residues for which no NMR constraints were available, this computer model fully agreed with X-ray structures of CMTI-I (Bode et al.: FEBS Lett. 242:285-292, 1989) and EETI-II complexed with trypsin that appeared after the RMD simulation was completed. Restrained molecular dynamics in water is thus proved to be highly valuable for refinement of DG structures. Also, the successful use of apolar/polar surface ratio and of solvation free energy reinforce the analysis of Novotny et al. (Proteins 4:19-30, 1988) and shows that these criteria are useful indicators of correct versus misfolded models.
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Affiliation(s)
- L Chiche
- Department of Pharmaceutical Chemistry, University of California San Francisco 94143-0446
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49
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Banaigs B, Jeanty G, Francisco C, Jouin P, Poncet J, Heitz A, Cave A, Prome J, Wahl M, Lafargue F. Didemnin B : comparative study and conpormational approach in solution. Tetrahedron 1989. [DOI: 10.1016/0040-4020(89)80045-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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50
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Fricker JP, Vergnes Y, Schach R, Heitz A, Eber M, Grunebaum L, Wiesel ML, Kher A, Barbier P, Cazenave JP. Low dose heparin versus low molecular weight heparin (Kabi 2165, Fragmin) in the prophylaxis of thromboembolic complications of abdominal oncological surgery. Eur J Clin Invest 1988; 18:561-7. [PMID: 2852111 DOI: 10.1111/j.1365-2362.1988.tb01268.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Eighty patients undergoing pelvic or abdominal surgery for cancer were randomized in two groups for prevention of postoperative thromboembolism: 40 patients received a 15,000 IU day-1 Calciparine prophylaxis and 40 patients a 5000 anti-Xa U/d Fragmin prophylaxis for 10 days. In the Calciparine group, two patients (5%) developed postoperative pulmonary embolism but none developed it in the Fragmin group. Two patients in the Fragmin group (5%) developed isotopic DVT, which was not confirmed by phlebography. There was no deep vein thrombosis of the lower limbs in the two groups. Important postoperative bleeding (one patient in the Calciparine group and two patients in the Fragmin group) was similar in both groups. Moderate and minor bleeding were significantly lower in the Fragmin group. Haemoglobin and haematocrit changes, total blood loss and transfusion requirements were not different in both groups. It is concluded that, over a 10-day period, one daily 5000 U Fragmin prophylaxis was as effective and safe as three daily 5000 IU Calciparine injections.
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Affiliation(s)
- J P Fricker
- Centre Régional de Lutte contre le Cancer Paul Strauss, Strasbourg, France
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