Stereospecific binding as a tool in attempts to localize and isolate muscarinic receptors. Part II. Binding of (plus)-benzetimide, (minus)-benzetimide and atropine to a fraction from bovine tracheal smooth muscle and to bovine caudate nucleus

The concentration-dependent binding of (+)-benzetimide-H³ and (?)-benzetimide-H³, the active and inactive enantiomers, respectively of the anticholinergic agent, (±)-benzetimide, and of atropine-³ to a fraction from bovine tracheal smooth muscle was studied by equilibrium dialysis. Analysis of the binding curves revealed the presence of a saturable high affinity binding site for (+)-benzetimide and atropine but not for (?)-benzetimide. The stereospecificity of the binding and the results of competition experiments with cholinergic and non-cholinergic compounds provided evidence, that the high affinity binding sites for (+)-benzetimide and atropine are identical with the muscarinic receptor. Attempts to solubilize the binding sites with detergents, commonly used in this type of work, resulted in complete loss of stereospecificity. Digitonin, a plant glycoside with mild detergent properties, released components to which (+)-benzetimide-H³ and (?)-benzetimide-H³ were still bound differently, strongly suggesting the presence of solubilized muscarinic receptors. The stereoselective binding sites for anticholinergic agents, as observed in the caudate nucleus, could also be solubilized with digitonin but only after hexane extraction of lyophilized homogenates.     

Absorbable polyglycolide screws in internal fixation of femoral osteotomies in rabbits

In 20 rabbits, a transverse distal femoral osteotomy was fixed using a 4.5 by 30-mm absorbable screw made of polyglycolide. No postoperative external support was used. The consolidation of the osteotomy was investigated histologically, morphometrically, and microradiographically in groups of 4 to 6 rabbits that were followed for 3, 6, 12, or 36 weeks. Fourteen osteotomies showed solid bony union; and in 3, several bone trabeculae were seen to bridge a still partially ununited osteotomy. In another 3 rabbits, each with a follow-up time of 12 or 36 weeks, no convincing signs of progressing consolidation could be seen. Only 1 of these rabbits showed displacement of the distal fraament.     

The management of obstructive hydrocephalus by the use of external continuous ventricular drainage

Summary External continuous ventricular drainage (CVD) in patients suffering from obstructive hydrocephalus is being used in many neurosurgical centers as a routine procedure for the temporary relief of intracranial pressure. The results of this treatment have been insufficiently evaluated.In the present study two groups of patients were investigated. In one, CVD was never used. In the other one it was used in all cases. It was found that the use of CVD decreased mortality rate most significantly.It is recommended that CVD should be used as a temporary measure for the treatment of the increased intracranial pressure in patients suffering from obstructive hydrocephalus.     

Off-pump coronary artery bypass grafting in a patient with Child class C liver cirrhosis awaiting liver transplantation

We report the case of a Child class C cirrhotic patient who was diagnosed with coronary artery disease in the course of his pretransplantation evaluation. He underwent off-pump coronary artery bypass grafting (OPCAB), which was complicated with acute renal failure. The morbidity and mortality associated with cardiac operation in patients with cirrhosis is discussed, and the potential advantage of OPCAB in this patient population is emphasized.