99mTc-pyrophosphate imaging in acute pericarditis: a clinical and experimental study.

Fifteen patients with clinical and electrocardiographic features of acute pericarditis underwent myocardial scintigraphy using 99mTc-pyrophosphate. All had normal images. In 5 additional patients with acute pericarditis and evidence of ischemic heart disease, 99mTc-pyrophosphate images showed focal abnormalities in 2 patients and equivocal findings in 2. Serial myocardial radionuclide images were obtained 2 to 18 days after induction of pericarditis in 8 dogs; all images were normal. No stainable tissue calcium was demonstrated histochemically in the pericardium or myocardium of these dogs. Our results suggest that 99mTc-PYP myocardial radionuclide images are normal in acute pericarditis in the absence of ischemic heart disease.     

EVALUATION OF THE "LONG CHAIN REACTION" AS A MEANS FOR DETECTING TYPE-SPECIFIC ANTIBODY TO GROUP A STREPTOCOCCI IN HUMAN SERA

Certain strains of Group A streptococci showed striking increase in chain length when grown in liquid media to which was added human sera that contained antibody to M protein of homologous type. This "long chain reaction" was shown to be a highly specific and sensitive biological test for human type-specific antibody and correlated closely with the classical bactericidal test. Patients infected with Type 12 or Type 3 Group A streptococci showed the appearance of anti-M antibody in their sera by both methods at similar intervals during convalescence. Of 217 sera studied in these patients the two tests showed agreement in all but 11 specimens. Of 99 patients who were bled serially following Type 12 or Type 3 infections, and whose sera were tested by both methods, there was close agreement, the bactericidal test being only slightly more sensitive. The advantages and limitations of this new biological test for human type-specific immunity are discussed.     

Kalium-Fluxe und Membranpotential am Froschvorhof in Abh?ngigkeit von der Kalium-Au?enkonzentration

Zusammenfassung 1. Um die Bedeutung der K-Ionen für das Ruhepotential näher zu untersuchen, wurde am Froschvorhof bei einer Variation des extracellulären K zwischen 0 und 108 mMol/l in neun Stufen jeweils die intracelluläre K- und Na-Konzentration, das Membranpotential V, das K-Gleichgewichtspotential E _K sowie der K-Efflux und -Influx an der Zellmembran bestimmt.2. Im allgemeinen ist das Membranpotential V vom Gleichgewichtspotential E _K verschieden. Für K-Außenkonzentrationen unterhalb 30 mMol/l ist V (im Absolutbetrag) kleiner, oberhalb davon größer als E _K. Im ersten Fall ist die treibende Kraft (V-E _K) auswärts, im zweiten Fall einwärts gerichtet.3. K-Efflux und -Influx nehmen monoton mit wachsender K-Außenkonzentration zu, mit sinkender Konzentration ab. Bei höheren Konzentrationen übersteigt der Influx den Efflux beträchtlich.4. Um den Anteil des aktiven Transports in den Fluxen zu eliminieren, wurde das Stoffwechselgift Dinitrophenol verwandt. DNP reduziert den K-Influx um rund 30% im gesamten Variationsbereich der K-Außenkonzentration, erhöht dagegen den K-Efflux um 40–100%. Das Membranpotential zeigt unter DNP eine Depolarisation um 2–3 mV. Alle diese Effekte treten mit einer Latenz von 1–2 min auf und sind mit der gleichen Latenz reversibel, falls die Applikation von DNP nicht länger als etwa 10 min dauert.5. Der unbeeinflußte K-Efflux einerseits und der durch DNP reduzierte Influx andererseits werden als die passiven Ionenbewegungen unter Normalbedingungen betrachtet. Die Differenz dieser beiden Fluxe entspricht dann dem passiven K-Nettostrom J _K. Der so bestimmte Nettostrom J _K korrespondiert mit der treibenden Kraft (V-E _K): Für K-Außenkonzentrationen unterhalb 30 mMol/l ist J _K auswärts, oberhalb davon einwärts gerichtet.6. Aus den Zahlenwerten von V, E _K und J _K läßt sich die K-Leitfähigkeit g _K = J _K/(V-E _K) errechnen. Die Leitfähigkeit, aufgefaßt als Funktion von (V-E _K), steigt auf hohe Werte an, wenn die treibende Kraft einwärts gerichtet ist, und sinkt in der entgegengesetzten Richtung auf niedrige Werte ab.7. Eine Bestimmung der K-Permeabilität P _K (im Sinn der Theorie von Goldman) führt zu dem Resultat, daß die Permeabilität — anders als die Leitfähigkeit — über dem gesamten Bereich der K-Außenkonzentration nahezu konstant ist.8. Eine Abschätzung der Na- und der Cl-Permeabilität ergibt, daß P _Na und P _Cl nur wenige Prozent von P _K ausmachen.9. Das Problem einer Wechselwirkung zwischen passivem Efflux und Influx wird an Hand der von Ussing und Teorell bzw. von Hodgkin u. Keynes angegebenen Fluxrelation untersucht. Der numerische Fluxvergleich macht es wahrscheinlich, daß eine geringfügige gegenseitige Behinderung der K-Fluxe besteht.10. Es wird gezeigt, daß die Fluxrelation von Hodgkin u. Keynes, die von den Autoren zunächst am Beispiel des single-file-Mechanismus abgeleitet worden ist, auch aus der Theorie von Goldman hergeleitet werden kann.

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Summary 1. In frog atria the K and Na content of the cells, the membrane potential V, the equilibrium potential E _K, and the K efflux and influx of resting preparations were determined as a function of external concentration [K]₀ between 0 and 108 mMol/l.2. For [K]₀ smaller than 30 mMol/l the membrane potential V (absolute value) was lower than the equilibrium potential E _K; for [K]₀ above 30 mMol/l V exceeded E _K.3. Both K efflux and influx were increased (decreased) by a rise (fall) of [K]₀. At higher K concentrations the influx exceeded the efflux considerably.4. 2-4-Dinitrophenole (DNP) as a metabolic inhibitor decreased the K influx by about 30% at all K concentrations but increased the K efflux by 40 to 100%. The membrane potential depolarized by 2–3 mV. These effects were reversible if DNP was applied for less than 10 minutes.5. The normal K efflux and the influx reduced by DNP were taken as the passive ion movements. The difference between these fluxes was regarded as the passive K net flux J _K.6. From the data of V, E _K, and J _K the potassium conductance g _K=J _K/(V-E _K) was calculated. The conductance reached high values when the driving force (V-E _K) was directed inwards but fell to very small values in the opposite case.7. The potassium permeability P _K as defined by the constant field theory of Goldman was nearly constant over the range of 0 to 108 mMol K/1.8. The permeabilities P _Na and P _Cl were estimated to be only a few percent of P _K.9. The problem of interdependence of K efflux and influx was studied using the flux relations of Ussing and Teorell and of Hodgkin and Keynes. A small interaction between efflux and influx was found.10. It is shown that the flux relation of Hodgkin and Keynes can be deduced from the constant field theory of Goldman if suitable assumptions are made.

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Ausgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft und des Bundesministeriums für wissenschaftliche Forschung.     

Studies on tryptophan accumulation in brain during methiothepin-induced enhancement of 5-hydroxyindole synthesis

Summary The elevation of brain tryptophan, 5-hydroxytryptophan and 5-hydroxyindoles (serotonin + 5-hydroxyindole acetic acid) that results from a tryptophan load is potentiated by prior administration of methiothepin, a serotonin receptor antagonist. Coadministration of valine with tryptophan attenuates these effects even in animals receiving methiothepin pretreatment. Administration of methiothepin and tryptophan to rats with widespread reduction of brain 5-hydroxyindole levels resulting from raphe lesions or 5,7-dihydroxytryptamine pretreatment still enabled brain tryptophan levels to rise considerably above the sum of increases found in animals receiving one or the other. Following transection of the spinal cord, the cranial portion still exhibited enhanced uptake of tryptophan and 5-hydroxyindole synthesis following methiothepin plus tryptophan treatment, however, both these events were absent in the caudal segment. Apparently, enhanced tryptophan uptake can proceed in the presence of minimal neuronal activity; however, when nerve impulse flow is eliminated, both 5-hydroxyindole synthesis and tryptophan uptake is impaired.Present address: City University of New York, Bronx Community College, Bronx, New York 10453, USASupported by National Institute of Neurological, Communicative Disease and Stroke, Grant No. 12876. The statistical assistance of Ms. Jean Chou is greatly appreciated.     

Localized Regressive Articular Cartilage Changes in the Hip Joint of the Rabbit following an Induced Synovitis

A talcum induced synovitis in the hip joint of the rabbit, which is known to cause articular cartilage hyperplasia followed by femoral head protrusion and joint incongruency, has in the present experiment also been shown to lead to localized regressive articular cartilage changes. The articular cartilage of the hip joints in 40 rabbits was examined histologically, at intervals, following induction of such a talcum synovitis. Regressive changes in the form of loss of surface chondrocytes and glycosaminoglycans sometimes accompanied by fibrillation, were found in the area of the femoral head articular cartilage which had become flattened following the head protrusion. Chondrocyte cloning facilitated subsequent cartilage repair. The biomechanical disturbance in the joint following the induced synovitis is felt to have caused the regressive changes. The experiment is considered to have some significance in connection with Legg-Calve-Perthes' Syndrome (L.C.P.S.) in children.