Clinical studies of gas exchange during ventilatory support--a method using the Siemens-Elema CO2 analyzer.

We describe a new portable infra-red analyses for use with the Siemens-Elema Servo ventilator. The sensor head constitutes a Y-piece connecting the patient to the ventilator tubing, and gives instant carbon dioxide determination. It is based upon simple principles that can be realized with modern techniques, offering for instance freedom from interference by anaesthetic gases, and eliminating the need for calibration.

Spontaneous reversion from long-lasting atrial fibrillation to sinus rhythm.

We have collected 23 cases with atrial fibrillation (AF) of 3-29 years' duration with spontaneous reversion to sinus rhythm (SR). We have also identified 22 similar cases in the literature. Several of our patients spent several years with different atrial arrhythmias before a stable SR was established.

Total hip replacement by the Müller-Charnley prosthesis. A follow-up study of 238 operations after 2 to 7 years.

A prospective study of 238 total hip replacements, with the Müller prosthesis, is presented. The complications in the total material and the results in 216 hips with follow-up times from 2 to 7 years are described. Eighty-four per cent of the hips were free from significant pain and 64 per cent had a total range of motion exceeding 160 degrees.

Effect of mexiletine on conduction of premature ventricular beats in man: a study using monophasic action potential recordings from the right ventricle.

Ventricular conduction intervals between a stimulating pacemaker electrode at the right ventricular apex and an impulse detecting monophasic action potential electrode at the right ventricular septum were measured in nine subjects. The right ventricle was paced at a constant rate and programmed premature ventricular stimuli were introduced after every eighth paced beat beginning at the refractory period. The ventricular conduction intervals were measured from the pacemaker artefact to the onset of depolarisation of the MAP recording.

Effect of mexiletine on monophasic action potentials recorded from the right ventricle in man.

The effect of mexiletine, a new antiarrhythmic agent, on ventricular refractoriness and monophasic action potentials recorded from the right ventricle was studied in nine subjects. The effective refractory period of the right ventricle was determined by the extra stimulus technique using a pacing electrode situated at the right ventricular apex. Following this determination the right ventricular apex was paced at a constant cycle length and premature stimuli were introduced starting at a coupling interval of 2 ms greater than the ventricular refractory period and then at progressively increasing coupling intervals of 5 ms increments.

Canine hip dysplasia: study of heritability in 401 litters of German Shepherd dogs.

Heritability of hip dysplasia was estimated to be about 0.4 to 0.5 when based on the radiographic evaluations of the hip joints of 2,404 German Shepherd Dogs born at The Armed Forces Dog Training Center in Sweden.

Verapamil-induced ventricular regularity in atrial fibrillation. Effects of exercise, isoproterenol, atropine and conversion to sinus rhythm.

The effects of physical exercise, isoproterenol and atropine upon the ventricular rate and regularity were studied in 12 patients with atrial fibrillation (AF) during verapamil-induced regular ventricular rhythm. Physical exercise, isoproterenol and atropine all caused a gradual loss of ventricular regularity during AF. Verapamil caused a reduction of exercise heart rate during AF and, to a minor extent, even during sinus rhythm.

A double-blind comparison of the clinical tolerance of bacampicillin and pivampicillin. A preliminary report.

In this double-blind study, the clinical tolerance of high doses of bacampicillin hydrochloride (800 mg t. i. d.

Effects of metoprolol on heart rate in patients with digitalis treated chronic atrial fibrillation.

Adequate control of ventricular rate in patients with chronic atrial fibrillation (AF) may not be achieved with digitalis alone. In the present study the additional effect of two different doses (50 mg and 50 +/- 50 mg) of oral metoprolol, a new selective beta-blocking agent, on ventricular rate in patients with longstanding AF has been studied. A decrease in the mean ventricular rate during rest and during exercise at various work loads was observed after both doses.

Long-term fate of [14C]nicotine in the mouse: retention in the bronchi, melanin-containing tissues and urinary bladder wall.

N-methyl-14C and 2'-14C-labelled nicotine were used for whole-body autoradiographic distribution studies on C57BL- and NMRI-mice. Radioactivity was retained in the melanin-containing tissues, in the bronchial walls, and in the urinary bladder wall, up to 1 month after administration. The activity levels in the bronchi decreased faster if [2'(14)C] nicotine was used.

Comparison of the electrophysiological effects of two neuroleptics, melperone and thioridazine, on isolated rat atria.

The effects of the two neuroleptics, melperone (a butyrophenone) and thioridazine (a phenothiazine), were compared on the electrical and mechanical activity of isolated rat atria. Both electrically stimulated and spontaneously beating atria were used. Melperone was found to prolong the effective refractory period while the threshold for electrical stimulation i.

Articular-cartilage proteoglycans in aging and osteoarthritis.

The composition of macroscopically normal hip articular cartilage obtained from dogs of various ages was studied. Pieces of cartilage with signs of degeneration were studied separately. In normal aging, the extraction yield of proteoglycans decreased; the keratan sulphate content of extracted proteoglycans increased and the chondroitin sulphate content decreased.