Clara's birth.

Advocacy for homebirth is based on the strong assumption that birthing is a physiological process and does not require medical interventions unless things turn "wrong." Let us assume that something might always go wrong, for instance during Clara's birth when the placenta was still retained after three hours. What needs to be done? The moment the midwife entered the house she was endowed with a responsibility for any problem caused by her failure to give proper guidance.

Studies on the mechanism of positive inotropic activity of Ro 13-6438, a structurally novel cardiotonic agent with vasodilating properties.

We investigated the possible mechanisms involved in the positive inotropic activity of Ro 13-6438 (R-6-chloro-1,5-dihydro-3- methylimidazo -[2,1-b] quinazolin -2[ 3H]-one), a structurally novel cardiotonic agent with vasodilating properties. The positive inotropic response to Ro 13-6438 of the isolated guinea pig papillary muscle was accompanied by inhibition of myocardial phosphodiesterase (PDE) activity and elevation of intracellular cyclic AMP (cAMP) levels Ro 13-6438 had no effect on Na+,K+-stimulated or Ca2+-stimulated ATPase activity and did not influence the rate of 45Ca uptake in cardiac membrane vesicles. Ro 13-6438 caused a concentration-dependent increase in the upstroke velocity, overshoot, and duration of slow action potentials evoked in partially depolarized papillary muscles.

Does [3H]nifedipine label the calcium channel in rabbit myocardium?

The ionic and drug specificities of the [3H]nifedipine binding site in rabbit cardiac homogenates were investigated. Divalent cations inhibited specific [3H]nifedipine binding in the potency order: Ni+2 greater than Ca+2 greater than or equal to Mg+2. Monovalent cations did not affect binding.

Characterization of [3H]nifedipine binding sites in rabbit myocardium.

A specific, high affinity (KD 1.8 nM) binding site for the calcium entry blocking drug [3H]nifedipine was identified in homogenates of rabbit myocardium. [3H]Nifedipine binding was rapid (t1/2 3 min) and reversible (t1/2 11 min).

Ca2+-dependent phosphorylation and Ca2+ uptake in membrane fractions of the mesenteric artery.

Ca2+-dependent phosphorylation of endogenous substrate proteins (mol. wt 30 800, 35 500, 38 600 and 53 200) is found in a membrane subcellular fraction from rabbit mesenteric arteries. Characteristics of 32P incorporation are suggestive of a phosphoester-type phosphorylation produced by a Ca2+-dependent protein kinase.