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This paper presents an open prospective investigation of the efficacy of balloon kyphoplasty in the treatment of intravertebral pseudarthrosis. Several described intravertebral radiolucent lines—the so-called vacuum phenomenon—originated from degenerative diseases. Pain arose from intravertebral dynamic mobility and local kyphosis.

During recent years, the benefits of balloon kyphoplasty and vertebroplasty have been frequently discussed for the treatment of osteoporotic vertebral compression fractures. Because of the lack of comparative studies, we performed an investigation to describe the mechanical effects and the impact on life quality during a follow-up period of 2 years.

Osteosarcoma is the most frequent malignant bone tumor, mainly occurring in the second and third decade of life. Diagnosis is limited to clinical symptoms, radiology and histology, but so far no diagnostic laboratory tests are available. Heat shock proteins (hsp ), highly conserved proteins performing vital intracellular chaperoning functions and preventing cells from death, have been shown to be involved in tumor immunity.

We wished to determine the preservation of contractile function of human saphenous veins during long-term storage (36 and 96 h) at low temperatures in different solutions. Two crystalloid solutions (Krebs-Henseleit and Bretschneider's cardioplegic solution), as well as heparinized blood and albumin solution as used in cardiac surgery were compared. Contractile function of human saphenous vein ring segments was tested in a vessel myograph. Potassium chloride (KCl 80 mM) was used to achieve receptor-independent maximal contraction; contractility to norepinephrine (NE) was tested in a concentration-dependent manner (10-8-10-6M). Nitroglycerin (NTG) was used to test vascular relaxation. Thirty-six hours of storage in 5% human albumin abolished responses to KCl and to NE. At this time, contraction of vein ring segments stored in heparinized blood was decreased to 24% in response to KCl and to 16% in response to NE. After 36-h storage in Bretschneider's cardioplegic solution, contractile function was not significantly decreased. The contraction was still 82% after KCl and was unchanged after NE. After 96 h, the contractile response was markedly impaired in all vein ring segments, and no relevant differences were evident between the solutions. In all experiments, NTG caused complete relaxation. Because Bretschneider's cardioplegic solution preserved vascular contractile function for 36 h, the implementation of this solution might enable long-term storage of human vessels for transplantation, bypass grafts, and in vitro experiments.

The effects of diltiazem were tested in chronically instrumented dogs in a model of exercise-induced myocardial dysfunction. Since various bradycardic agents have beneficial effects on myocardial function during ischemia, it was of interest to find out how a decrease in afterload, possibly combined with a decrease in myocardial oxygen demand, influences dysfunction. Therefore, diltiazem (1 mg/kg i.v.) was tested during critical stenosis of the circumflex branch of the left coronary artery, which led to exercise-induced myocardial dysfunction. At rest, diltiazem causes a reflex increase in heart rate. During exercise, a decrease in heart rate and hence in myocardial oxygen demand was neutralized by a decrease in arterial blood pressure and hence a lowered myocardial perfusion pressure. Therefore, systolic shortening in the ischemic area improved neither at rest nor during exercise after diltiazem.

Summary The antiischemic effects of tedisamil were investigated in chronically instrumented conscious dogs. Heart rate, arterial blood pressure, left ventricular dP/dtmax, left ventricular end-diastolic pressure, and regional myocardial shortening in the ischemic and normal myocardium, assessed by sonomicrometry, were measured. Reversible regional myocardial dysfunction was achieved by graded treadmill exercise in the presence of a critical coronary stenosis, which was produced by partial inflation of a hydraulic occluder. Regional myocardial dysfunction, which was observed befere the intravenous drug administration, was almost completely abolished by tedisamil (180 μg/kg/5min). The antiischemic effect of tedisamil is due to a reduction in heart rate, which leads to a decrease in left ventricular dP/dtmax and myocardial oxygen demand in the presence of a prolongation of diastole and thus coronary perfusion time. Clinical evaluation will test the value of this drug for the treatment of stress-induced symptomatic and asymptomatic angina pectoris in humans.

The β-blocking activity of flestolol was established during increasing isoprenaline infusions and during graded physical exercise in conscious, chronically instrumented dogs. After a control cycle, flestolol was infused at three doses (1, 2.67, and 10 μg/kg/min). Flestolol has an extremely short half-life, demonstrated by an 83 loss of effect within 25 min. Thus, flestolol allows easy titration of the effect, which might be a valuable property for its use in the treatment of critically ill patients. Due to the difference between pure β-adrenergic stimulation and the much more complex regulation of circulation during exercise, the hemodynamic response to flestolol elicited marked differences between both set ups. Flestolol shifted the dose-response curves of isoprenaline-induced changes in heart rate, positive left ventricular dp/dtmaxand diastolic arterial pressure dose dependently to the right, while its main effect during exercise was a decrease in positive left ventricular dp/dtmax. Thus, testing of β-adrenoceptor blockers using isoprenaline-induced tachycardia leads to an overestimation of potency and therefore is not appropriate to predict the clinical efficacy of these drugs to prevent stress- or exercise-induced in-creases in heart rate and hence myocardial oxygen-demand.

Stimulation of 5-HT1A receptors is known to decrease the arterial blood pressure in anaesthetized rats, cats and dogs. We investigated the hypotensive activity of flesinoxan (0.1 + 0.2 + 0.7 µmol/kg), a 5-HT1A-receptor agonist, in dogs anaesthetized with either morphine and pentobarbital or enflurane and also in the conscious state. Flesinoxan led to a decrease in arterial blood pressure in anaesthetized, but not in conscious dogs. In the conscious state the marked increase in heart rate, which can be taken as an indicator of sympathetic tone, may have masked the consequences of vasodilatation. These different haemodynamic responses to flesinoxan may be dependent on side effects of the drug in the conscious dogs, in particular hyperventilation and salivation combined with anxiety, and on the magnitude of the decrease in baroreceptor reflex activity during anaesthesia with morphine and pentobarbital on the one hand and enflurane on the other hand.