bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthese und Strukturaufklärung einiger unsymmetrisch substituierter 2.4‐Bis‐imino‐1.3‐diazetidine
Authors: Burkhardt Jürgen , Hamann Karl
Published: June 2007

Phenylisocyanid‐dichlorid (3) kondensiert mit primären Alkylendiaminen zu 2.4‐Bis‐imino‐1.3‐diazetidinen 5. Der Strukturbeweis wird an Hand der IR‐ und NMR‐Spektren geführt.
Metallkomplexe der Phosphinsäuren, V. Über Dithiophosphinatokomplexe von Kupfer, Silber, Gold und Thallium
Authors: Kuchen Wilhelm , Mayatepek Hakki
Published: June 2007

Tetramere CuI‐Komplexe [R2P(S)SCu]4 (R  C2H5, C3H7, C2H5O) und dimere AuI‐Komplexe [R2P(S)SAu]2 (R  C2H5, C3H7) von Dithiophosphinsäuren R2P(S)SH bzw. Diäthyldithiophosphat (C2H5O)2P(S)SH wurden u. a. in einer Redoxreaktion neben Polysulfanen nach Gl. (4) bzw. (6) erhalten. Die Molekülgrößen der entsprechenden Phenylverbindungen [(C6H5)2P(S)SM]n (M  CuI AuI) sind jedoch noch unbekannt. – Über die Eigenschaften und einige Reaktionen dieser Komplexe, für die Strukturvorschläge gemacht werden, wird berichtet. – Dithiophosphinat R2P(S)S− (R  C2H5, C3H7, C4H9) gibt mit AgI die vermutlich polymeren Komplexe [R2P(S)SAg]n und mit TlIII, wiederum in einer Redoxreaktion, die Disulfane R2P(S)S2P(S)R2 neben den Thallium(I)‐Komplexen R2P(S)STl (R  C2H5, C6H5). Letztere sind in Chloroform und Benzol konzentrationsabhängig assoziiert.
Über Imidoyl‐isothiocyanate, II
Authors: Goerdeler Joachim , Weber Dieter
Published: June 2007

Synthese, Charakterisierung und Umsetzungen der Imidoyl‐isothiocyanate werden beschrieben; insbesondere die Isomerisierung zu Chinazolthionen (3), 1.4‐Cycloadditionen zu Pyrimidin‐thionen und Triazin‐thionen (hierzu zählt auch die charakteristische Dimerisierung) sowie Reaktionen mit 1.3‐dipolaren Verbindungen zu Thiadiazolen.
Über 1.4‐Diaza‐fulvene
Authors: Rohr Wolfgang , Swoboda Robert , Staab Heinz A.
Published: June 2007

Darstellung und Eigenschaften von 1.4‐Diaza‐fulvenen (4a – c) werden beschrieben. Für 4 ist die Leichtigkeit nucleophiler Reaktionen an C‐6 typisch: Hydratation führt zu 2, Methanol‐Addition zu 8, Hydrierung mit Natriumborhydrid zu 9. Cycloadditionen von Ketenen, Isocyanaten und ähnlichen Verbindungen ergeben bicyclische Systeme (z. B. 10, 11, 13, 15 und 16).
Über eine neue Synthese von Tetraaryl‐imidazolen und Pentaaryl‐imidazolium‐Salzen
Authors: Heinze Jürgen , Baumgärtel Helmut , Zimmermann Herbert
Published: June 2007

Aus Derivaten des ms‐[N‐Acyl‐anilino]‐desoxybenzoins 3 entstehen durch Einwirkung von Phosphorpentachlorid substituierte ms‐[N‐(α‐Chlor‐aryliden)‐anilinio]‐desoxybenzoin‐chloride 4. Bei der Umsetzung mit überschüssigem Ammoniak gehen diese in 1.2.4.5‐tetraaryl‐substituierte Imidazole 5 über. Setzt man 4 mit primären Aminen um, so bilden sich Derivate der N‐Desyl‐amidinium‐chloride 6, die bei Einwirkung von Thionylchlorid Wasser abspalten und unter Ringschluß in 1.2.3.4.5‐pentaaryl‐substituierte Imidazolium‐Salze 7 übergehen. Eine größere Zahl neuer Imidazolderivate war auf dem beschriebenen Weg in guten Ausbeuten zugänglich.
Über die Reaktionen von einigen konjugiert ungesättigten Kohlenwasserstoffen mit Diazomethan und Diazoäthan
Authors: Paul Heinz , Kausmann Axel
Published: June 2007

Die Cycloadditionen des Diazomethans und Diazoäthans an Butadien‐(1.3), 2.3‐Dimethylbutadien‐(1.3), Vinylacetylen und Diacetylen werden geklärt, die Konstitutionen der entstehenden Pyrazoline bzw. Pyrazole gesichert.
Synthesen mit naszierenden Chinonen, IV. Basenkatalysierte Alkoholaddition an in situ erzeugte o‐Chinone
Authors: Wanzlick Hans‐Werner , Jahnke Ulrich
Published: June 2007

Durch Dehydrierung von Brenzcatechin und 4‐Methyl‐brenzcatechin in Methanol (Äthanol) werden die Alkoxy‐o‐chinone 1, 2 und 3 erhalten. Einige Reaktionen des 4.5‐Dimethoxy‐o‐benzochinons (1) werden beschrieben.
Über Metalltrifluorphosphin‐Komplexe, XXIII. Darstellung und Reaktionen der Tetrakis(trifluorphosphin)‐metallhydride von Kobalt, Rhodium und Iridium
Authors: Kruck Thomas , Lang Winfried , Derner Norbert , Stadler Martin
Published: June 2007

Tetrakis(trifluorphosphin)‐metallhydride, HM(PF3)4, von Kobalt und seinen Homologen entstehen in hohen Ausbeuten bei Druckumsetzungen von PF3/H2‐Gemischen mit einem Gemenge aus Metallsalz und Kupferpulver bei erhöhter Temperatur. Sie bilden sich auch quantitativ beim Ansäuren ihrer Tetrakis(trifluorphosphin)‐metallate(—I) mit Mineralsäuren. Die Kobaltverbindung ist außerdem durch Direktsynthese aus den Elementen und PF3 zugänglich.

Diese komplexen Metallhydride zeichnen sich durch hohe thermische Stabilität und geringe Luftempfindlichkeit aus. Die Siedepunkte der gelbstichigen (Co) bzw. farblosen (Rh, Ir) Flüssigkeiten liegen unter 100°. Das chemische Verhalten wird im wesentlichen durch ihren stark sauren Charakter bestimmt. In wäßriger Lösung fallen mit großvolumigen Kationen die Komplexsalze der Tetrakis(trifluorphosphin)‐metallate(—I) aus. Die Alkalisalze dieser Anionen, z. B. K[M(PF3)4], entstehen durch Umsetzung der Hydride mit Alkalimetallamalgamen. Das Kobalthydrid liefert in Äther mit Diazomethan das Oxoniumsalz [(C2H5)2OCH3][Co(PF3)4], mit Triphenylphosphin zunächst das Phosphoniumsalz [(C6H5)3PH][Co(PF3)4], das sich oberhalb 140° in das substituierte Hydrid HCo(PF3)3P(C6H5)3 umwandelt; mit Triphenylarsin und ‐stibin entstehen sofort die Monosubstitutionsprodukte HCo(PF3)3L. Mit Jodoform reagiert HCo(PF3)4 unter H/J‐Austausch zu CH2J2 und JCo(PF3)4.
Über Phosphazene, XX. Organosubstituierte Diphospha‐s‐triazine, Darstellungswege, Eigenschaften und Kernresonanzspektren
Authors: Schmidpeter Alfred , Ebeling Joachim
Published: June 2007

Am Phosphor symmetrisch und unsymmetrisch phenyl‐ und methylsubstituierte Diphospha‐s‐triazine 1 können auf folgenden Wegen dargestellt werden: aus einem Diphosphornitridtrichlorid und überschüssigem Amidin (Guanidin) in Lösung bei Raumtemperatur, über ihre beim Verschmelzen von Diphosphornitrid‐trichloriden und Amidiniumchloriden im Vakuum erhältlichen Hydrochloride 6, aus einem Aminodiphosphazen und N.N′‐Diphenyl‐form‐amidin durch thermisches Abspalten von Anilin (6‐H‐Verbindungen) und durch thermische Isomerisierung eines Cyan‐aminodiphosphazens (6‐NH2‐Verbindungen). —1H‐und 31P‐NMR‐Spektren belegen die Struktur der Produkte. Darin fallen die hohen Kopplungen zwischen den Protonen der 6‐Substituenten und dem Ringphosphor auf. In den Hydrochloriden 6 wird das Proton rasch zwischen den Positionen 1 und 5 ausgetauscht, im 2.2.6‐Trimethyl‐4.4‐diphenyl‐diphospha‐s‐triazin steht es bevorzugt in 1‐Position. Die Abhängigkeit der 31P‐Verschiebungen wird diskutiert.
Benzolazoketone und Tetrahydroindazole aus Phenylhydrazonen cyclischer β‐Dicarbonylverbindungen
Authors: Teuber Hans‐J. , Worbs Ernst , Cornelius Dieter
Published: June 2007

Die als vinyloge Carbonsäure‐phenylhydrazide anzusprechenden Monophenylhydrazone substituierter Cyclohexandione‐(1.3) 2a—k und 4—6 sowie das Monophenylhydrazon 15 des 2.4‐Diphenyl‐cyclopentandions‐(1.3) werden dehydriert und hydriert. Bei der Dehydrierung mit Sauerstoff, salpetriger Säure oder Dichromat/Eisessig entstehen die roten bis braunen Benzolazo‐cyclohexenone 3a—c, g, j—m bzw. das Benzolazo‐cyclopentenon 18. Diese vinylogen α‐Carbonyl‐Azoverbindungen können mit Phenylhydrazin zu den entsprechenden Phenylhydrazonen 1a, f, h, n, o weiterreagieren, die die Eigenschaften von Cyaninfarbstoffen besitzen. Aus dem Benzolazoketon des unsubstituierten Cyclohexandions‐(1.3) (3a) kann dabei über die Stufe 1a hinaus das sauerstoffhaltige «Cyanin»19 entstehen. Die Neigung zur Bildung der Verbindungen 3 und 1 erklärt die z.Tl. geringen Ausbeuten bei der Darstellung der Phenylhydrazone 2.

Weitere Reaktionen einzelner Vertreter mit Eisessig, mit Halogenwasserstoffen, mit aromatischen Aldehyden sowie mit Boranat werden studiert. Das spektroskopische Verhalten der Phenylhydrazone, ihrer Dehydrierungs‐ und Hydrierungsprodukte wird verglichen.
Beiträge zur Chemie des Bors, XLIII. Dimethylcarbamoyloxy‐ und Dimethylthiocarbamoylmercaptodiborane(4)
Authors: Abeler Gerd , Nöth Heinrich , Schick Hannes
Published: June 2007

Durch Einschiebung von CO2 bzw. CS2 in B–N‐Bindungen von Dimethylamino‐diboran(4)‐Verbindungen resultieren Dimethylcarbamoyloxy‐ bzw. Dimethylthiocarbamoylmercapto‐Derivate. Die im Vergleich zu R2B2(OR)2 und R2B2(SR)2 beträchtliche Stabilität von R2B2[OC(O)N(CH3)2]2 (3) und R2B2[SC(S)N(CH3)2]2 (2) wird auf das Vorliegen von Bor der Koordinationszahl 4 zurückgeführt.
Ketenderivate, XIV. Stabile p‐Chinodimethane, II: Reaktionen
Authors: Gompper Rudolf , Wagner Hans‐Ulrich , Kutter Eberhard
Published: June 2007

Aus ω.ω‐Bis‐alkylmercapto‐ω′.ω′‐dicyan(und verwandten)‐p‐chinodimethanen entstehen in starken Säuren Dicyanmethylaryl‐Carboniumionen, die sich durch ihre NMR‐Spektren nachweisen lassen. – Mit primären und sekundären Aminen reagiert das Äthylendimercaptochinodimethan 2 unter Abspaltung von Dithioglykol zu Bis‐alkylamino‐chinodimethanen. Mit Perhydrol in Eisessig lassen sich Bis‐alkylmercapto‐chinodimethane zu Bis‐alkansulfon‐chinodimethanen oxydieren.
Zur Kenntnis des Jodtrifluorids
Authors: Schmeißer Martin , Ludovici Werner , Naumann Dieter , Sartori Peter , Scharf Emil
Published: June 2007

Durch Einwirkung von F2 auf in CCl3F suspendiertes J2 bei −45° wurde Jod(III)‐fluorid als gelbe, bis −28° stabile Substanz erhalten. Durch Umsetzung von JF3 mit schweren Alkalifluoriden in CH3CN gelingt die Darstellung von Alkalitetrafluorojodaten(III). NOF und JF3 in CCl3F bilden NOJF4, mit AsF5 bzw. SbF5 entstehen JF2AsF6 und das 19F‐NMR‐spektroskopisch charakterisierte JF2SbF6. Mit aromatischen Stickstoffbasen bildet JF3 stabile 1 : 1‐ Addukte, die sich IR‐ und UV‐spektroskopisch deutlich von Addukten der JF5/J2‐ bzw. JF5/JF‐Gemische unterscheiden.
Darstellung von α.ω‐Bis‐[1.2.4‐triazolyl‐(3)]‐alkanen
Authors: Spassov Alexander , Demirov Georgi
Published: June 2007

Aus N3‐Phenyl‐benzamidrazon und Dicarbonsäure‐dichloriden entstehen in guter Ausbeute α.ω‐Bis‐[4.5‐diphenyl‐1.2.4‐triazolyl‐(3)]‐alkane.
Barriers to effective drug addiction treatment for women involved in street‐level prostitution: a qualitative investigation
Authors: Smith Frances M. , Marshall Lisa A.
Published: June 2007

Objectives To examine barriers to effective drug addiction treatment for women involved in street‐level prostitution.

Methods A qualitative approach was selected to enable a detailed exploration, in an informal and unthreatening manner, of the barriers to drug addiction treatment from the women's perspective. Nine in‐depth interviews were conducted with women who were involved in street‐level prostitution. Transcripts of one‐to‐one interviews were analysed for recurrent themes using Interpretative Phenomenological Analysis.

Results Barriers to effective addiction treatment are present at psychological, interpersonal, and wider societal levels. Themes identified included: an impoverished sense of self‐worth, a lack of trust and consistency in treatment, and the absence of a comprehensive treatment package.

Conclusion Current services could be improved by the provision of a structured treatment programme designed to target the specific physical and psychological requirements of this population. Also, efforts to correct the fictitious, negative portrayals of women involved in prostitution are required, if treatment efficacy is to be improved. Copyright © 2007 John Wiley & Sons, Ltd.
Structural and Spectroscopic Studies of Halocuprate(I) and Haloargentate(I) Complexes [M2XnX′4‐n]2‐.
Authors: Bowmaker Graham A. , Bruce Michael I. , Skelton Brian W. , Somers Neil , White Allan H.
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Pyrazole and Isoxazole in Triethanolamine Medium.
Authors: Agrawal Nitin N. , Soni P. A.
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Convenient Synthetic Route to Enantiopure N‐Tosylazetidines from α‐Amino Acids.
Authors: Ghorai Manas K. , Das Kalpataru , Kumar Amit
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Catalytic Enantio‐ and Diastereoselective Formation of β‐Sultones: Ring‐Strained Precursors for Enantioenriched β‐Hydroxysulfonyl Derivatives.
Authors: Koch Florian M. , Peters Rene
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Regioselective Microwave‐Assisted Synthesis of Substituted Pyrazoles from Ethynyl Ketones.
Authors: Bagley Mark C. , Lubinu M. Caterina , Mason Christopher
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Design, Synthesis and Biological Evaluation of New Oxazines with Potential Antiparasitic Activity.
Authors: Gamenara Daniela , Heinzen Horacio , Moyna Patrick
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of CL‐20 (IV) by Oxidative Debenzylation with Cerium(IV) Ammonium Nitrate (CAN)
Authors: Gore G. M. , Sivabalan R. , Nair U. R. , Saikia A. , Venugopalan S. , Gandhe B. R.
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chemical Constituents of Evolvulus nummularius.
Authors: Dinda Biswanath , Ghosh Biplab , Arima Shiho , Sato Nariko , Harigaya Yoshihiro
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Recent Studies on Reaction Pathways and Applications of Sugar Orthoesters in the Synthesis of Oligosaccharides
Authors: Kong Fanzuo
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Application of Ring Closing Metathesis in Efficient Syntheses of Macrocyclic Crown Compounds
Authors: Ibrahim Yehia A.
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Trifluoromethylation of Metal Enolates and Theoretical Guideline
Authors: Mikami Koichi , Itoh Yoshimitsu
Published: June 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enantioseparation using urea‐ and imide‐bearing chitosan phenylcarbamate derivatives as chiral stationary phases for high‐performance liquid chromatography
Authors: Yamamoto Chiyo , Fujisawa Mari , Kamigaito Masami , Okamoto Yoshio
Published: June 2007

Completely deacetylated chitosan was prepared by the treatment of commercial chitosan with 50% aqueous NaOH, and then derivatized into several new chitosan phenylcarbamate derivatives having a urea and an imide moiety at the 2‐position of the glucosamine ring by the reaction with isocyanate and phthalic anhydride/isocyanate, respectively. The chitosan derivatives were coated on macroporous silica gel and evaluated as chiral stationary phases (CSPs) for high‐performance liquid chromatography. The chiral recognition ability of the chitosan derivative was improved using the completely deacetylated chitosan. Among the novel chitosan derivatives, the 3,5‐dimethyl‐, 3,5‐dichloro‐, and 3,4‐dichlorophenylcarbamate derivatives were found to possess relatively high chiral resolution abilities. The CSPs based on the chitosan phenylcarbamate‐urea and ‐imide derivatives were stable in the presence of chloroform and ethyl acetate as a component of the eluents, and some racemates were better resolved by such eluents. The dichlorophenylcarbamate‐imide derivatives showed a high chiral recognition for metal acetylacetonate complexes. The enantiomerization of Al(acac)3 was performed on the chitosan 3,5‐dichlorophenylcarbamate‐imide derivative CSP and the resulting chromatogram showed a 26% (+)‐isomer enrichment. Chirality, 2008. © 2007 Wiley‐Liss, Inc.
Intrinsic asymmetries of amino acid enantiomers and their peptides: A possible role in the origin of biochirality
Authors: Deamer David W. , Dick Reay , Thiemann Wolfram , Shinitzky Meir
Published: June 2007

L‐amino acids and D‐carbohydrates were incorporated into the first forms of life over 3.5 billion years ago, presumably from racemic mixtures of organic solutes produced by abiotic synthetic pathways. The process by which this choice occurred has not been established, but a consensus view is that it was a chance event, such that life could equally well have used D‐amino acids and L sugars. In this review we will explore a second, less plausible alternative that minute differences in the physical properties of certain enantiomers made it more likely that L‐amino acids and D‐carbohydrates would be incorporated into early life. By all classical criteria, chiral isomers are perfect mirror image structures and, therefore, are expected to be identical in their macroscopic properties. However, scattered reports in the literature suggest that there may be slight differences in the physical properties of L‐ and D‐amino acids and their polymers, which could lead to a preferred incorporation of L‐amino acids into primitive forms of life. Here we present a literature survey of this issue and discuss its possible role in the origin of biochirality. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Trends in long‐term management of survivors of acute myocardial infarction by cardiologists in a government university‐affiliated teaching hospital
Authors: Mitra S. , Findley K. , Frohnapple D. , Mehta J. L.
Published: June 2007

Background: Despite prospective randomized control trials showing that beta blockers, aspirin, angiotensin‐converting enzyme (ACE) inhibitors, and lipid‐lowering agents improve survival rates after myocardial infarction (MI), these agents are routinely underutilized.

Hypothesis: Our aim was to determine the frequency with which cardiologists at a government, university‐affiliated teaching hospital prescribe aspirin, beta blockers, ACE inhibitors, calcium‐channel blocking agents (CCBs), and lipid‐lowering agents in patients post MI. The patients were followed by their primary care physicians in this hospital after discharge. We evaluated changes in patients' medical management at an average of 24 months after discharge from the acute event.

Methods: Clinical data relative to long‐term use of life‐saving drugs in 156 survivors of definite MI (WHO criteria) at a government, university‐affiliated teaching hospital were analyzed over a 24‐month follow‐up period.

Results: Over 90% of patients with acute MI were given aspirin and beta blockers at discharge. About 50% of these patients were given ACE inhibitors, only 25% were prescribed CCBs, and 21% were given lipid‐lowering agents. At 24 months of follow‐up, the percentage of patients receiving aspirin, beta blockers, and ACE inhibitors had fallen to 88% (p = 0.0408), 71% (p < 0.0001), and 43% (p = 0.1122), respectively, whereas use of lipid‐lowering agents slightly increased (p = 0.4277). Use of CCBs had also fallen (p = 0.0001). Nonetheless, the use of aspirin, beta blockers, and ACE inhibitors was higher than that in the National Registry of similar patients at discharge (p < 0.0001).

Conclusions: Patients at a government, university‐affiliated teaching hospital are likely to receive life‐saving therapy at discharge, in accordance with the American College of Cardiology/American Heart Association (ACC/AHA) guidelines. There is a modest decrease in intake of these life‐saving drugs during the follow‐up period. As documented earlier, cardiologists in a teaching institution are more likely to prescribe established life‐saving drugs than do primary care physicians. However, full‐time primary care physicians at a university‐affiliated teaching hospital continue to use these therapies at a higher rate than do those outside academic medicine.
Smoking cessation, but not smoking reduction, reduces plasma homocysteine levels
Authors: Stein James H. , Bushara Magda , Bushara Khalaf , McBride Patrick E. , Jorenby Douglas E. , Fiore Michael C.
Published: June 2007

Background: Cigarette smoking has been associated with increased plasma homocysteine levels. Although hyperhomocysteinemia may mediate some of the adverse cardiovascular consequences of smoking cigarettes, the effects of smoking cessation and smoking reduction on homocysteine levels have not been evaluated previously.

Hypothesis: The purpose of this study was to determine the effects of smoking cessation and smoking reduction on plasma homocysteine levels.

Methods: Fifty‐one healthy subjects who smoked 35.9 ± 6.4 cigarettes daily were randomized to continue smoking, reduce smoking to 4‐8 cigarettes daily, or to stop smoking. A nicotine inhaler and individualized counseling were provided as aids to smoking cessation.

Results: In subjects who quit smoking, homocysteine levels decreased by 11.6%, from 8.58 ± 2.31 to 7.53 ± 2.26 μmol/l (p = 0.013). Significant changes in homocysteine levels were not observed in subjects who reduced smoking or continued to smoke.

Conclusion: A “harm reduction” strategy of reducing cigarette use may not be sufficient for reducing the vascular risk associated with smoking cigarettes.
Sarpogrelate, a specific 5ht2‐receptor antagonist, improves the coronary microcirculation in coronary artery disease
Authors: Satomura Kimio , Takase Bonpei , Hamabe Akira , Ashida Kazuhiro , Hosaka Haruhiko , Ohsuzu Fumitaka , Kurita Akira
Published: June 2007

Background: Serotonin (5‐hydroxytryptamine: 5‐HT) reduces the coronary blood flow (CBF) as a product of aggregating platelets. Sarpogrelate, a specific 5HT2‐receptor antagonist, has been reported to increase the coronary collateral flow in humans; however, its effect on the microcirculation is still not fully understood.

Hypothesis: This study was undertaken to determine whether sarpogrelate might improve the microcirculation in coronary artery disease (CAD).

Methods: To investigate the effect of sarpogrelate on the microcirculation in CAD, we measured CBF in 15 patients with CAD but no significant stenosis in the left anterior descending artery (LAD). The patients were randomly allocated to two groups, including those receiving oral administration of 200 mg of sarpogrelate (SPG, 8 patients, age 61 ± 6 years) and those receiving no medication (controls, 7 patients, age 57 ± 8 years). Prior to and 1 h after the administration of sarpogrelate, or in controls at 1‐h intervals, the average peak velocity (APV) at baseline and hyperemia was measured by an intracoronary Doppler guidewire. Systemic blood pressure (SBP) and cardiac output (CO) were also measured.

Results: In the patients receiving SPG, the medication significantly increased the baseline (18 ± 9 to 19 ± 10 cm/s, p < 0.05) and maximal APV (55 ± 9 to 64 ± 31 cm/s, p < 0.05). However, no significant changes were observed in SBP and CO after the administration of SPG. In the control group, there were no significant differences in baseline and hyperemic APV.

Conclusion: Sarpogrelate increased both baseline and maximal CBF without changing the systemic hemodynamics. These findings thus support that SPG improves the microcirculation by antagonizing the vasoconstrictive products of the aggregating platelets in CAD.
Gender differences in arrhythmias
Authors: Wolbrette Deborah , Naccarelli Gerald , Curtis Anne , Lehmann Michael , Kadish Alan
Published: June 2007

Electrocardiographic and electrophysiologic differences between men and women have long been noted. Women have a higher intrinsic heart rate than men, along with a longer corrected QT interval and a shorter sinus nodal recovery time. The incidence of and risk factors for a variety of arrhythmias differ between men and women. Atrioventricular nodal reentry tachycardia has a 2:1 female‐to‐male predominance, while accessory pathways are twice as frequent in men. Although atrial fibrillation is more prevalent in men of all age groups, the absolute numbers of men and women with atrial fibrillation are equal, and the associated morbidity and mortality experienced by women with atrial fibrillation appear to be worse. Women have a lower incidence of sudden cardiac death, and female survivors of sudden cardiac death have a lower frequency of spontaneous or inducible ventricular tachycardia. On the other hand, drug‐induced torsade de pointes and symptomatic long QT syndrome have a female predominance. Therefore, greater caution should be used when prescribing QT‐prolonging drugs in women. The incidence of arrhythmias is increased during pregnancy, and management of pregnant patients poses a significant challenge. The mechanisms of these gender differences are unclear but may be related to hormonal effects and the shorter QT interval in adult males. Pharmacologic and nonpharmacologic therapies are usually equally efficacious, but the risks of pharmacologic therapy are different in men and women. Atrial fibrillation may be more difficult to treat in women.
Investigation of the predictors of transition to persistent atrial fibrillation in patients with paroxysmal atrial fibrillation
Authors: Koide Yasushi , Yotsukura Masayuki , Sakata Konomi , Yoshino Hideaki , Ishikawa Kyozo
Published: June 2007

Background: Until now, no clinically useful indicators have existed that predict the transition from paroxysmal to persistent atrial fibrillation (AF).

Hypothesis: The current prospective study was conducted for identifying predictors of progression to persistent AF over the long term.

Methods: We studied 102 consecutive patients (mean age: 55 ± 10 years; 75 men and 27 women) diagnosed with paroxysmal AF. Standard 12‐lead electrocardiography, echocardiography, and P‐wave‐triggered signal‐averaged electrocardiography (P‐SAECG) were performed on all patients at the time of their entry into the study.

Results: The mean follow‐up period was 61 ± 13 months. Group 1 (n = 66) comprised patients in whom paroxysmal AF did not progress to persistent AF, and Group 2 (n = 36) comprised those who developed persistent AF. In Group 2 the patients were significantly older, and P‐wave dispersion, filtered P‐wave duration (FPD), and left atrial dimension were significantly higher than in Group 1 (p < 0.05). The root mean square voltage for the last 30 ms of the filtered P‐wave was also significantly lower in Group 2 (p < 0.05). Multivariate logistic regression analysis using these five factors identified left atrial dimension (odds ratio [OR] 2.29; 95% confidence interval [CI] 1.16‐4.54; p = 0.02) and FPD (OR 2.71; 95% CI 1.78‐ 4.13; p< 0.01) as independent predictors of transition to persistent AF. Left atrial dimension ≤ 40 mm predicted progression to persistent AF with a sensitivity of 64%, specificity of 76%, positive predictive value of 59%, negative predictive value of 79%, and an accuracy of 71%. An FPD ≤ 150 ms predicted persistent AF with a sensitivity of 81%, specificity of 91%, positive predictive value of 88%, negative predictive value of 90%, and an accuracy of 87%. Filtered P‐wave duration was a significantly more sensitive and specific predictor than left atrial dimension (p < 0.05).

Conclusion: We conclude that FPD is a clinically useful predictor of progression from paroxysmal to persistent AF over the long term.
Vitamin C preserves endothelial function in patients with coronary heart disease after a high‐fat meal
Authors: Liu Ling , Zhao Shui‐Ping , Gao Mei , Zhou Qi‐Chang , Li Yu‐Ling , Xia Bing
Published: June 2007

Background: It has been suggested that an oxidative mechanism is involved with the impaired endothelium‐dependent vasodilatation that occurs after a high‐fat meal.

Hypothesis: The study was undertaken to evaluate the effect of a single oral dose of vitamin C (2 g) on postprandially impaired endothelium‐dependent vasodilatation in patients with coronary heart disease (CHD).

Methods: This study included 74 patients with CHD and 50 subjects without CHD with risk factors. The two groups were divided into two subgroups that did or did not receive 2 g of vitamin C (CHD/VitC and CHD/control, n = 37; non‐CHD/VitC and non‐CHD/control, n = 25) after a high‐fat meal (800 calories, 50 g fat). Serum levels of triglyceride, total cholesterol, low‐density lipoprotein cholesterol, and high‐density lipoprotein cholesterol in the fasting state and at 2, 4, 5, and 7 h after the high‐fat meal were measured. Endothelial function was assessed in the brachial artery by high‐resolution ultrasound at baseline and at 4 h postprandially.

Results: The postprandial serum triglyceride concentration increased significantly at 2‐5 h after the high‐fat meal in all groups. The fasting flow‐mediated dilatation (FMD) (p < 0.02) and nitroglycerin‐induced dilatation (NID) (p < 0.05) of patients with CHD were impaired compared with those of non‐CHD subjects. Postprandial FMD was significantly aggravated in the non‐CHD/control group (p<0.01) and the CHD/ control group (p < 0.001), but the postprandial FMD in patients and subjects taking vitamin C showed no significant change, although the CHD/VitC group had a mild tendency toward improvement (p = 0.064) and non‐CHD/VitC group had a mild tendency toward aggravation (p = 0.852). The change of NID after a high‐fat meal did not reach statistical significance in the four groups. The decrement of postprandial FMD correlated positively with the increment of 2‐h serum triglyceride concentration in the patients without vitamin C (n = 62, r = 0.545, p < 0.001).

Conclusions: The postprandial state after a high‐fat meal is critical in atherogenesis, as it induces endothelial dysfunction through an oxidative stress mechanism. Vitamin C treatment has a promising benefit for patients with CHD.
Novel use of a short‐acting intravenous beta blocker in combination with inotropic therapy as a bridge to chronic oral beta blockade in patients with advanced heart failure
Authors: Hauptman Paul J. , Woods Daniel , Pritzker Marc R.
Published: June 2007

The role for beta blockers in advanced heart failure (New York Heart Association class IV) remains undefined because of concerns about tolerability and uncertainty about efficacy. We report the use of a short‐acting intravenous beta blocker in combination with inotropic therapy as a means to bridge five patients with advanced heart failure to chronic oral beta blockade; two of these patients had been chronically managed with intravenous inotrope. At 4 months' follow‐up, all patients remained on beta‐blocker therapy and none was hospitalized for heart failure or had received intravenous diuretics. Given the early separation of survival curves in the randomized clinical trials of beta blockers in heart failure, it is possible that these patients will accrue a survival benefit. We conclude that some patients with advanced heart failure can be offered oral beta‐blocker therapy by bridging with a combination of intravenous inotrope and short‐acting intravenous beta blocker.
T‐peak to T‐end interval may be a better predictor of high‐risk patients with hypertrophic cardiomyopathy associated with a cardiac troponin i mutation than qt dispersion
Authors: Shimizu Masami , Ino Hidekazu , Okeie Kazuyasu , Yamaguchi Masato , Nagata Mitsuru , Hayashi Kenshi , Itoh Hideki , Iwaki Taku , Oe Kotaro , Konno Tetsuo , Mabuchi Hiroshi
Published: June 2007

Background: Patients with hypertrophic cardiomyopathy (HCM) associated with a deletion of lysine 183 (K183del) in the cardiac troponin I (cTnI) gene suffer sudden cardiac death at all ages. However, the correlation between QT variables and sudden cardiac death in these patients remains uncertain.

Hypothesis: We evaluated the correlation between QT variables and sudden cardiac death and/or ventricular tach‐yarrhythmia (SCD/VT) in patients with HCM associated with the cTnI mutation.

Methods: We analyzed 10 probands with HCM associated with the cTnI gene K183del and their family members. The subjects were divided into three groups: Group A (n = 7), mutation carriers with SCD/VT; Group B (n = 16), mutation carriers without SCD/VT; Group C (n = 24), no mutation carriers. QT intervals were corrected using Bazett's formula.

Results: Maximum QTc and corrected QT dispersion were significantly longer in Groups A and B than in Group C. However, there were no differences in either parameter between Groups A and B. On the contrary, the peak‐to‐end interval of T wave/QT interval in V5 (Tpe) in Group A was significantly longer than that in Groups B and C. Logistic regression analysis revealed that Tpe was a good clinical predictor for SCD/VT in patients with HCM in this study.

Conclusions: These results suggest that Tpe rather than QT dispersion may be one of the best predictors for SCD/VT in patients with HCM associated with the K183del mutation in the cTnI gene.
Coronary collaterals during single‐vessel coronary angioplasty: Effects of nitroglycerin
Authors: Eriksen Ulrik Hedegaard , Nielsen Torsten Toftegaard , Egeblad Henrik , Bagger Jens Peder
Published: June 2007

Background: Although the protective role of collaterals in coronary artery disease (CAD) is well known, the influence of drugs on collateral function remains controversial.

Hypothesis: We aimed to investigate prospectively the prevalence of spontaneously visible and recruitable coronary collaterals in consecutive patients with single‐vessel CAD and the effect of systemic administration of nitroglycerin on these types of collaterals during percutaneous transluminal coronary angioplasty (PTCA).

Methods: Ipsi‐ and contralateral coronary artery contrast injections were performed before and during PTCA. Simultaneously with balloon occlusion, we measured coronary artery occlusion pressure via the balloon catheter. All measurements were repeated after administration of 0.5 mg of nitroglycerin intravenously.

Results: Of 101 consecutive patients, 24% had spontaneously visible and 30% had recruitable collaterals. Contra‐lateral collaterals were five times more frequent than ipsilateral collaterals. Presence of collaterals was highly associated with the degree of coronary stenosis. Coronary occlusion pressure was higher in patients with than in those without collaterals. Collaterals prevented pain and ischemia during PTCA, and in this respect spontaneously visible collaterals were more effective than recruitable collaterals. There was no effect of systemic administration of nitroglycerin on appearance or occlusion pressure of coronary collaterals.

Conclusion: Coronary collaterals were found in more than half of patients with single‐vessel CAD, as the prevalence of recruitable collaterals was slightly higher than that of spontaneously visible collaterals. Nitroglycerin did neither recruit nor augment coronary collaterals.
Ventricular dyssynchrony in dilated cardiomyopathy: The role of biventricular pacing in the treatment of congestive heart failure
Authors: Aranda Juan M. , Schofield Richard S. , Leach Dana , Conti Jamie B. , Hill James A. , Curtis Anne B.
Published: June 2007

Despite advances in pharmacologic therapy, the prognosis of patients with advanced congestive heart failure (CHF) remains poor. Many of these patients have cardiac conduction abnormalities, such as left bundle‐branch block or interventricular conduction delays, that can lead to ventricular dyssynchrony (abnormal ventricular activation that results in decreased ventricular filling and abnormal ventricular wall motion). Biventricular pacing is an alternative, Nonpharmacologic therapy under active investigation for the treatment of CHF. Resynchronization devices with transvenous leads in the right atrium, right ventricle, and left ventricle (via the coronary sinus) have been implanted in patients to provide atrial triggered biventricular pacing. The use of such devices has been associated with improvement in ejection fraction, dP/dt, stroke work, and functional class. The proposed mechanisms involved in improving ventricular function with biventricular pacing include improved septal contribution to ventricular ejection, increased diastolic filling times, and reduced mitral regurgitation. This article reviews the pathophysiology of ventricular dyssynchrony and examine insights from clinical trials that are evaluating cardiac resynchronization therapy for CHF.
Persistent st‐segment elevation after primary stenting for acute myocardial infarction: Its relation to left ventricular recovery
Authors: Lee Sang‐Gon , Cheong Jong‐Pil , Shin Je‐Kyoun , Kim Jin‐Woo , Park Jae‐Hoo
Published: June 2007

Background: Early restoration of coronary artery patency in acute myocardial infarction (AMI) has been linked to improvement in survival. However, early recanalization of an occluded epicardial coronary artery by either thrombolytic agents or percutaneous transluminal coronary angioplasty (PTCA) does Not Necessarily lead to left ventricular (LV) function recovery.

Hypothesis: The aim of this study was to evaluate the relation between persistent ST elevation shortly after primary stenting for acute myocardial infarction (AMI) and LV recovery.

Methods: Thirty‐one patients with primary stenting for AMI were prospectively enrolled. To evaluate the extent of microvascular injury, serial ST‐segment analysis on a 12‐lead electrocardiogram recording just before and at the end of the coronary intervention was performed. Persistent ST‐segment elevation (Persistent Group, N = 11) was defined as ≥50% of peak ST elevation and resolution (Resolution Group, N = 20) was defined as < 50% of peak ST elevation. Echocardiography was performed on Day 1 and 3 months after primary stenting.

Results: At 3 months, infarct zone wall‐motion score index (WMSI, 2.1 ± 0.6 vs. 2.7 ± 0.3, p < 0.05) was smaller in the Resolution Group than in the Persistent Group, whereas wall motion recovery index (RI, 0.4 ± 0.3 vs. 0.1 ± 0.2, p < 0.05) and ejection fraction (58 ± 5 vs. 43 ± 10%, p < 0.05) were larger in the Resolution Group than in the Persistent Group. The extent of persistent ST elevation (% ST) shortly after successful recanalization of the infarct‐related artery was significantly related to RI at 3 months (r = −0.4, p < 0.05). However, time to reperfusion was Not related to RI at 3 months. There was also significant correlation between corrected TIMI frame count and %ST (r = 0.4, p < 0.05).

Conclusions: Persistent ST‐segment elevation shortly after successful recanalization (≥ 50% of the peak value), as a marker of impaired microvascular reperfusion, predicts poor LV recovery 3 months after primary stenting for AMI.
Catheter ablation of atrial fibrillation
Authors: Ng Fu Siong , Camm Ajohn
Published: June 2007

Following the advent of the surgical maze procedure, several catheter techniques have been developed to provide permanent prophylaxis against atrial fibrillation. These Noninvasive techniques work by compartmentalizing the atria, by ablating the arrhythmogenic foci, or by isolating the atria from these foci. Although still at an early stage of development, preliminary results using focal ablation and circumferential ablation show extreme promise.
Quadricuspid aortic valves
Authors: Timperley Jonathan , Milner Robert , Marshall Andrew J. , Gilbert Timothy J.
Published: June 2007

Quadricuspid aortic valves (QAV) are a rare but well recognized cause of significant aortic regurgitation. The first case was found reported in 1862. Since then there have been 110 reported cases of QAV and we report 4 more. Previously, these were diagnosed at the time of surgery or postmortem examination. With advances in echocardiography, including harmonic imaging, and also the advent of trans‐esophageal echocardiography, more cases are being diagnosed prior to surgery. We describe four more cases, three diagnosed preoperatively and one at the time of surgery, and then review the previously reported cases. Of the 114 cases reported, 46 had the aortic valve replaced, most commonly in the 5th and 6th decade of life. Hurwitz and Roberts classified quadricuspid valves according to the size of the leaflets. It has previously been believed that QAVs with four equal sized leaflets were less likely to develop significant aortic regurgitation; however, on review of the available cases, this would not appear to be the case. The preoperative diagnosis of QAVs is important as they can be associated with abnormally placed coronary ostium. Of the 114 cases reported, there are 10 reports of abnormally placed ostia. There has been at least one reported case of death occurring because of obstruction of an abnormally placed right coronary ostium by a prosthetic aortic valve.
QT‐interval dispersion in acute myocardial infarction is only shortened by thrombolysis in myocardial infarction grade 2/3 reperfusion
Authors: Nikiforos Savas , Hatzisavvas John , Pavlides Gregory , Voudris Vassilis , Vassilikos Vassilis P. , Manginas Athanassios , Hatzeioakim George , Foussas Stefanos , Iliodromitis Efstathios K. , Hatseras Demetrios , Kremastinos Demetrios T. , Cokkinos Dennis V.
Published: June 2007

Background: Increased QT interval dispersion (QTd) has been found in patients with acute myocardial infarction (AMI). In previous studies this has been shown to decrease with thrombolysis.

Hypothesis: The aim of this study was to compare the effects of reperfusion by primary percutaneous transluminal coronary angioplasty (PTCA) and by thrombolysis on QTd and correlate these results with the degree of reperfusion.

Methods: We studied 60 patients with a first AMI. The study cohort included 40 consecutive patients who had received thrombolysis (streptokinase or rt‐PA); 20 additional consecutive patients with successful primary PTCA, all with preselected Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow by predefined selection criteria (12 stents); and 20 controls. A 12‐lead ECG for QTd calculation was recorded before thrombolysis or PTCA and immediately after the procedure. All values were corrected according to Bazett's formula (QTcd). QTd and QTcd values before and after each procedure in three groups and the respective percent changes of ΔQTd and ΔQTcd were compared separately.

Results: QTd and QTcd were significantly increased before thrombolysis/PTCA versus normals. An angiogram performed after thrombolysis showed adequate reperfusion (TIMI grade 2/3) in 20 patients, while in the other 20 only TIMI 0/1 reperfusion was achieved. Thrombolysis‐TIMI flow 2/3 and PTCA significantly reduced QTd (from 68 ± 10 to 35 ± 8 ms, p < 0.001, ΔQTd = 48 ± 11%, in the Thr‐TIMI flow 2/3 group, and from 79 ± 11 to 38 ± 9 ms, p < 0.001, ΔQTd = 52 ± 9%, in the PTCA group), while in the Thr‐TIMI flow 0/1 group no significant changes were recorded. A percent QTd decrease > 30 s had 96% sensitivity, 85% specificity, and 93% positive and 94% negative predictive value, respectively, for TIMI 2/3 flow.

Conclusions: A significant decrease in QT dispersion may provide an additional electrocardiographic index for successful (TIMI 2/3) reperfusion.
Oral platelet glycoprotein IIb/IIIa receptor inhibitors—part I
Authors: Cannon Christopher P.
Published: June 2007

With the central importance of antiplatelet therapy in patients with coronary artery disease and the numerous positive trials with glycoprotein (GP) IIb/IIIa inhibitors given intravenously, it was hoped that one could extend the benefit of IIb/IIIa inhibition to long‐term treatment. Although the hypothesis that prolonged oral IIb/IIIa inhibition was appealing, many issues have been identified in the initial Phase II trials that would limit the usefulness of these compounds. Variability of the level of platelet inhibition was one major culprit that distinguished the oral compounds from intravenous ones. The problems that arose were that increased bleeding has been seen when levels of platelet inhibition are high (e.g., > 90%) and that, conversely, efficacy would likely be limited when levels of platelet inhibition were low. If further development of this class of drugs is undertaken, formal dosing studies would have to establish an oral dosing strategy that achieves appropriately high (80–95% inhibition) and steady levels of inhibition.
Myocardial bridging increases the risk of coronary spasm
Authors: Teragawa Hiroki , Fukuda Yukihiro , Matsuda Keiji , Hirao Hidekazu , Higashi Yukihito , Yamagata Togo , Oshima Tetsuya , Matsuura Hideo , Chayama Kazuaki
Published: June 2007

Background: Myocardial bridging (MB) has been associated with cardiac events. Whether coronary spasm is one factor contributing to those events is unknown.

Hypothesis: This study investigated whether the likelihood of coronary spasm is increased in patients with MB.

Methods: A spasm‐provocation test was performed by infusing acetylcholine into the left coronary artery in 114 Japanese patients with chest pain. The test result was defined as positive when the diameter of the coronary artery was reduced by > 50% and ST‐segment changes were documented. Myocardial bridging was defined as a > 15% reduction in coronary arterial diameter during systole after intracoronary injection of nitroglycerin.

Results: Myocardial bridging was identified in 41 patients (36%) and was located in the mid‐segment of the left anterior descending coronary artery (LAD) in all patients. Patients with MB experienced coronary spasm more frequently than patients without MB (MB+: 73%; MB —: 40%, p = 0.0006). Furthermore, among patients with a positive spasm‐provocation test, coronary spasm occurred more frequently in the midsegment of the LAD in patients with MB than in those without MB (MB+: 73%; MB — : 45%, p = 0.0259). Multivariate regression analysis demonstrated that MB was a predictor of coronary spasm (odds ratio: 3.478, p = 0.0088).

Conclusions: These results suggest that MB increases the risk of coronary spasm and that coronary spasm may be the proximate etiology of cardiac events associated with MB.
Exercise electrocardiography after acute coronary syndromes: Still the first testing modality?
Authors: Hurst J. Willis , Bigi Riccardo , Cortigiani Lauro , Desideri Alessandro
Published: June 2007

Recent diagnostic and therapeutic advances have been questioning the role of exercise electrocardiography (ECG) for risk stratification of patients recovering from an acute coronary syndrome. The aim of this review was to verify whether evidence still exists supporting the use of exercise ECG as first choice stress testing modality in this clinical setting in the light of the most recent prognostic data and of cost effectiveness considerations. It was concluded that a large body of evidence supports the use of exercise ECG as a cost‐effective tool for prognostic purposes and for quality of life assessment following acute coronary syndromes.