Doppelwahrnehmungen

Ohne Zusammenfassung     

THE EFFECT OF HYPERTENSIVE EPISODES AND CARDIAC HYPERTROPHY ON THE CANINE CARDIAC BAROREFLEX

1. Left ventricular (LV) hypertrophy has been implicated in the reduction of baroreflex sensitivity present in hypertension. The aim of the current study was to investigate the mean arterial pressure-heart rate reflex (MAP-HR) in a model which induced left ventricular hypertrophy but no sustained blood pressure elevation. 2. Five mongrel dogs were exposed to transient blood pressure elevation of between 20 and 30 mmHg, through hindlimb compression using a pneumatic pressure suit, for 7 h per day, 6 days per week for 6 weeks. Resting blood pressure was not altered by the 6 week hindlimb compression intervention. 3. Echocardiographically determined LV mass (mean ± s.e.m.) was 116.0 ± 7.4 g prior to hindlimb compression (baseline) and elevated to 125.4 ± 8.1 g (P= 0.003) after 6 weeks of compression. A reduction in the early (E) to late (A) transmitral diastolic flow ratio (E/A) from 1.80 ± 0.06 at baseline to 1.54 ± 0.09 (P = 0.037) after the 6 week intervention suggested that cardiac compliance was reduced. 4. The maximum gain of the MAP-HR reflex, studied using the ‘steady-state’ drug technique, when blood pressure was normal, showed a trend for reduction from 3.85 ± 0.43 beats/min per mmHg at baseline to 3.10 ± 0.45 beats/min per mmHg (P= 0.067) after 6 weeks of compression. This gain reduction became significant after β-adrenoceptor blockade with propranolol (3.13 ± 0.55 vs 2.32 ± 0.25 beats/min per mmHg; P= 0.039). Covariant analysis showed a significant inverse correlation between LV mass and maximum gain (r= 0.96; P<0.001) during the 6 week compression period. 5. The MAP-HR reflex changes in this model mimic those present in hypertension and implicate cardiac hypertrophy as one possible mediator.     

Beitrag zur Kenntnis der Flöhe von Brit.-Kolumbien

Ohne Zusammenfassung     

Ueber die Abhängigkeit phthisischer Lungenerkrankung von primären Kehlkopfaffectionen

Ohne ZusammenfassungHierzu Tafel IX.     

Influence of indenyl ligand substitution pattern on metallocene-catalyzed propene copolymerization with 1-octene

Copolymerization of propene with 1-octene (1 mol/1 mol) was performed in toluene at 40°C in the presence of homogeneous methylaluminoxane (MAO)-activated ansa-metallocenes in order to study the role of benzannelation and 2-methyl-substitution of the silylene-bridged bisindenyl ligand on comonomer incoporation, molecular mass, molecular mass distribution, and end groups. While 2-methyl-substitution promoted higher degree of polymerization without affecting copolymerization parameters, benzannelation improved markedly 1-octene incorporation. Only with MAO-activated rac-Me₂Si(2-MeBenz[e]Ind)₂ZrCl₂ catalysts vinylidene end groups were formed exclusively. Molecular weight distribution remains narrow in all experiments.     

Malignant hyperthermia in a 41-year-old woman

Malignant hyperthermia is one of the most devastating crises encountered in anaesthesia and it frequently occurs unexpectedly. Although malignant hyperthermia develops in young individuals (mean age approximately 22 years), older people can also be affected. The case of a 41-year-old woman with a history of several previously uneventful general anaesthetics is described. She developed the complete symptomatology of malignant hyperthermia triggered by halothane anaesthesia, with tachycardia, cardiac arrhythmia, cyanosis, combined respiratory and metabolic acidosis and hyperpyrexia. Because treatment with dantrolene and hyperventilation with 100% O2 was started immediately, the symptoms of malignant hyperthermia were stopped within a short time. It should always be remembered, that the life threatening crises which can be caused by malignant hyperthermia can occur at any age and even after several uneventful anaesthetics.