Stereoselectivity of actions of the calcium sensitizer [+]-EMD 60263 and its enantiomer [-]-EMD 60264

The thiadiazinone derivative [+]-EMD 60263 ((+)-5-(1-(α-ethylimino-3,4-dimethoxybenzyl)-1,2,3,4- tetrahydroquinoline-6-yl)-6-methyl-3,6-dihydro-2H-1,3,4 -thiadiazine-2-on) is a Ca²⁺-sensitizing agent with only minor phosphodiesterase inhibitory activity. Our aim was to characterize the inotropic and electrophysiological effects of [+]-EMD 60263 and its enantiomer [-]-EMD 60264 in several cardiac muscle preparations. The Ca²⁺-sensitizing activity resided in the [+]-enantiomer only. [+]-EMD 60263 (3 μM) shifted the EC₅₀ of Ca²⁺ for contractile activation of skinned fibers of pig heart from 2.41 μM to 0.73 μM, whereas [-]-EMD 60264 (30 μM) was ineffective. In Langendorff-perfused guinea pig hearts, [+]-EMD 60263 and [-]-EMD 60264 induced concentration-dependent positive and negative inotropic effects, respectively; both enantiomers reduced spontaneous heart rate but did not influence perfusion pressure. The maximum increase in force of human atrial trabeculae was 35 % of pre-drug control with [+]-EMD 60263 in comparison to 113 % with forskolin. In guinea-pig papillary muscles, [+]-EMD 60263 and [-]-EMD 60264 had opposite inotropic responses, however, both agents similarly prolonged action potential duration. Both enantiomers concentration-dependently blocked the rapidly activating component I_Kr of the delayed rectifier in guinea-pig myocytes. The block saturated at potentials positive to +30 mV, closely resembling the effects of the antiarrhythmic agent E-4031 which had been originally used to define I_Kr. It is concluded, that the positive inotropic action of [+]-EMD 60263 can be explained by prevalence of the Ca²⁺-sensitizing effect. The accompanying prolongation in action potential duration is caused by block of the I_Kr component of the delayed rectifier. While the inotropic effects are stereoselective, most of the electrophysiological actions are clearly independent of sterical configuration. The combination of Ca²⁺-sensitizing with class-III antiarrhythmic action may provide an interesting pharmacological profile of potential therapeutic use. Received: 7 January 1997 / Accepted: 25 February 1997     

Über die Bedeutung der Hauterscheinungen beim akuten Gelenkrheumatismus

Zusammenfassung Die Auffassung des akuten Gelenksrheumatismus als allergische Krankheit bedingt auch die Deutung der diese Erkrankung begleitenden Hauterscheinungen als allergische Phänomene. Das Erythema annulare und die Urticaria rheumatica werden im Sinne toxisch-allergischer Effloreszenzen erklärt, und der Rheumatismus nodosus diesen beiden Hautveränderungen als periphere hyperergische Entzündung bei einer bestimmten Reaktionslage des sensibilisierten Organismus symptomatologisch und prognostisch nahegestellt. An Hand mehrerer Fälle werden Beobachtungen gebracht, daß die erwähnten peripheren Erscheinungen klinisch ähnliches Geschehen begleiten und somit ihre engere innere Verwandtschaft als wahrscheinlich angenommen. Erythema annulare, Urticaria rheumatica und Rheumatismus nodosus begleiten eine Generalisation der rheumatischen Infektion und treten meist dann auf, wenn die Herzklappen, das Nervensystem oder die serösen Häute ergriffen werden. Alle drei Phänomene haben auch gemeinsame Beziehungen zu Allergieschwankungen im Organismus. In diesem Sinne werden die erwähnten Erscheinungen als Symptome eines allergischen Sekundärstadiums der akuten Polyarthritis aufgefaßt (ähnlich den sekundären Hauteffloreszenzen bei der Tuberkulose) und ihnen als Indikatoren der Generalisation der rheumatischen Noxe, besondere prognostische Bedeutung zugemessen.     

Complement component C5a predicts restenosis after superficial femoral artery balloon angioplasty.

PURPOSE: To investigate whether balloon angioplasty of the superficial femoral artery (SFA) increases serum levels of C5a and whether C5a predicts risk of restenosis. METHODS: C5a antigen was measured at baseline and 8 hours after intervention in 131 consecutive patients (76 women; median age 72 years) with intermittent claudication who underwent successful primary SFA balloon angioplasty. Patients were followed for a median 10 months [interquartile range (IQR) 6 to 14] for the occurrence of >50% restenosis by duplex ultrasound. RESULTS: Median C5a levels increased significantly from 39.7 ng/mL (IQR 27.8 to 55.0) at baseline to 53.8 ng/mL (IQR 35.6 to 85.1, p<0.001) 8 hours post intervention. During the follow-up period, 70 (53%) patients developed restenosis. Increasing levels of C5a (quartiles) at baseline were significantly associated with an increased risk for restenosis (p=0.0092). Adjusted hazard ratios (95% confidence intervals) for restenosis with increasing quartiles of baseline serum C5a levels were 1.24 (0.60 to 2.58), 1.93 (0.95 to 3.93), and 2.08 (1.02 to 4.21), respectively, compared to the lowest quartile. This effect was independent of nonspecific inflammation as reflected by plasma levels of C-reactive protein. CONCLUSION: Inflammatory mechanisms play a major role in the development of restenosis after angioplasty. The complement component C5a exerts strong chemotactic and proinflammatory effects. Enhanced complement activation prior to PTA, as measured by higher levels of C5a, was significantly associated with restenosis after SFA balloon angioplasty. Pathways of complement inhibition thus may be worth investigating with respect to improving patency rates.     

Über Familiäre Tieflandstruma mit Untersuchungen Über den Deuterium-Oxydgehalt Eines „Kropfbrunnens“

Ohne ZusammenfassungDie Arbeit wurde vom Gesundheitsdepartement des Landesamtes für die Slovakei (Reg.-RatDr. Kohut undDoz. Dr. Tománek) subventioniert, wofür auch an dieser Stelle ergebenst gedankt sei.     

Odontogenic myxoma: review of the literature and report of 30 cases from South Africa.

OBJECTIVE: The purpose of the study was to analyze the clinical and radiographic features of central odontogenic myxomas (OM) of the jaws diagnosed over 23 years in a black South African patient sample. STUDY DESIGN: Records of 30 cases of OMs with radiographs of diagnostic quality were retrieved from 52 cases of histopathologically verified OMs from the archives of the Oral Health Center at the University of Limpopo, South Africa. The age, sex, size, location, and radiographic features were compared with the literature. RESULTS: The study consisted of 21 females and 9 males. The correlation between age and size of the tumor was found to be statistically significant (P = .004). Septa were shown to be either reorientated cortical bone or sheets of dense fibrous connective tissue. Indistinct borders mimicked malignancy. The most common radiographic feature was the tennis-racket appearance. CONCLUSIONS: Variations in radiographic presentation make a radiological differential interpretation of OM challenging because the radiographic features overlap with those of other benign and malignant neoplasms.     

Einzelreferate und Buchbesprechungen

Ohne Zusammenfassung     

Das Elektrokardiogramm des gesunden Frühgeborenen,Neugeborenen und Säuglings

Ohne ZusammenfassungMit 5 Textabbildungen.