The effectiveness of the one tube method of osmotic fragility with three buffered solutions (0.32% saline, 0.36% saline, and tyrode) as a screening test for beta-thalassaemia trait was evaluated in several groups of subjects from Greece, Yugoslavia, and Thailand. The results clearly demonstrated that 0.36% saline is the most sensitive and effective solution since it could detect 96 to 100% of h...

1. Effects of caffeine on tension in the dog papillary muscle were investigated using a voltage clamp with the double sucrose-gap method. 2. An S-shaped relationship between membrane potential and developed tension was obtained in Tyrode solution. An increase of the external calcium concentration produced an upward shift of the relationship and a decrease of calcium, a downward shift. 3. Caffei...

OBJECTIVE We determined, via a bioassay, if inotropic factors are released in the coronary circulation of the rat heart and if changes in cardiac perfusion change papillary muscle inotropy. METHODS An isolated isometrically contracting rat papillary muscle (n = 5, acceptor) was superfused with Tyrode or with reoxygenated coronary venous effluent from an isolated isovolumically beating rat hea...

We have used immunogold staining to locate thrombospondin (TSP) on thrombin-activated human platelets, and have compared its distribution with that of fibrinogen (or fibrin) on thrombin- and ADP-stimulated platelets. To do this, isolated platelets were incubated with monospecific antibodies to TSP or fibrinogen (fib) and the bound IgG located with a second antibody adsorbed to gold particles. T...

Pacemaker activity was induced in trabecular muscle fibers of canine hearts using oxygenated Tyrode solution with added barium chloride. Following exposure to barium (0.2 to 5 HIM) the resting potential decreased toward zero from 10 to 60%, depending on the concentration. Simultaneously, the duration of the action potential increased and early diastolic hyperpolarization appeared with diastolic...

• In previous papers from this laboratory,' it has been shown that isolated guinea pig and cat hearts perfused with Tyrode solution without substrates undergo a decrease in rate, a decrease in amplitude of the R wave, a lengthening of the P-R interval, ventricular premature contractions, A-V dissociation, and, finally, ventricular fibrillation. The ventricular fibrillation, induced by the lack ...

Immune mechanisms active against Brucella were studied under conditions of oxygen deficiency. B. melitensis grew in rabbit serum-Tyrode medium flooded with N(2) and CO(2) gas mixtures. Immune sera from rabbits injected with B. melitensis strain Rev I possessed growth-inhibitory activity that operated in anaerobic environments against Rev I and virulent strain 6015. When mixed with macrophages, ...

The aim of the present study was to evaluate invitro and invivo antiasthmatic activity of ethanolic bark extract of Symplocos racemosa. For invitro study, isolated guinea pig ileum was used and dose response curve of histamine in plain Tyrode solution and in Tyrode solution containing 25 μg/ml ethanolic barks extract of Symplocos racemosa were performed. For invivo study histamine induced bronc...

• In previous papers from this laboratory,' it has been shown that isolated guinea pig and cat hearts perfused with Tyrode solution without substrates undergo a decrease in rate, a decrease in amplitude of the R wave, a lengthening of the P-R interval, ventricular premature contractions, A-V dissociation, and, finally, ventricular fibrillation. The ventricular fibrillation, induced by the lack ...