Success or failure of open heart surgery is closely related to the effect of myocardial protection, and at present there is no unanimity of opinion as to the ideal protecting method. In this paper we compared the effects of myocardial protection on isolated rabbit heart afforded by the cold (4°C) oxygen-carrying perfluorotripropylamine (FTPA) cardioplegic solution (group A) and those afforded by the cold (4°C) St. Thomas cardioplegic solution (group B). We studied lactate dehydrogenase (LDH) in the effluent fluid of coronary sinus and ultrastructure of myocardial cells. No statistically significant difference in LDH release activity was observed between group A and group B during heart arrest perfusion, but it was evidently higher in group B than in group A during rewarming at 5, 10, 30, 45 min. Ultrastructure destructive changes of myocardium went alongside with the increase of release of the enzyme. After 45 min of rewarming perfusion, group A hearts showed essentially normal ultrastructure, but those in group B showed evident swelling of mitochondria, vesiculation and fatty changes of cytoplasm, dissolution and fragmentation of myofibrils, etc. The experimental results indicate that FTPA cardioplegic solution offers better myocardial protection than does St. Thomas cardioplegic solution.
The aim of this study is to carry out enzymatic digestion of cell wall polysaccharides using β-(1–3)-glucanase to prepare antigen extracts of cell wall and cytoplasma of Candida albicans. These antigens were used to measure in vitro lymphocyte transformation and in vivo skin test responses in rabbits following inoculation with living C. albicans. The results of this study show that both cell-wall and cytoplasmic antigens of C. albicans in both the yeast and mycelial phases induce high levels of transformation in the infected host. The in vivo skin test, which gave indurated reactions typical of delayed type hypersensitivity, confirmed the in vitro findings. In addition, the in vitro cellular responses were not influenced in any major way by the presence of immune serum. Whole blood and purified leukocyte microculture techniques were established to test cellular reactivity in vitro. Although no report was found in the literature previously on the use of the whole blood leukocyte (WBL) assay system for the measurement of cellular mediated immune (CMI) responses to Candida antigens, the correlation between the WBL and peripheral blood leukocyte assay system indicates that its use is a valid way to measure CMI in vitro. The nature of the cells involved in the in vitro response of immunized rabbits was further characterized. Leukocyte cultures depleted of T-cells, B-cells or monocytes showed that T-cells and monocytes were essential for the production of the transformation response in vitro.
The effect of hyperthermia induced by environmental heat stress on the vascular interoceptor reflexes was studied in rabbits under urethane anesthesia (l g/kg). The pressor reflex was elicited by occlusion of the common carotid artery, and the depressor reflex by stimulation of the depressor nerve. The arterial blood pressure and the rectal temperature were recorded continuously. Besides, the firing rate of the depressor nerve was recorded by means of an X-Y recorder through a bioelectric impulse analyzer made in our department. The nerve discharges were amplified by a preamplifier and monitored on an oscilloscope. The arterial blood pressure was maintained at a relatively stable level in most cases until the rectal temperature rose to 41°-42 °C, and then fell significantly above this temperature. The decrease of pressor reflex began at 40°-41 °C, and was more marked at a higher rectal temperature, whereas the decrease of the depressor reflex occurred only when the temperature rose to 42 °C and was not so significant as that of the pressor reflex. The firing rate of the depressor nerve showed no decrease in all the seven cases, however it increased significantly in two. The mechanism for the reduction of the vascular interoceptor reflexes under heat stress-induced hyperthermia was analysed experimentally. The results suggested that the reduction of the vascular interoceptor reflexes was not due to impaired responsiveness of the effectors, i.e. heart and vascular smooth muscle, nor due to that of the arterial baroreceptor, but due to weakening of the regulatory function of the cardiovascular centers.
Anisodamine (654-2) administered intra-enterically for 30-min without reaching the systemic circulation before hemorrhage significantly prevented the accumulation of the lysosomal hydrolase cathepsin D in the plasma during hemorrhagic hypotension and postoligemic period and at the same time significantly attenuated the progression of hemorrhagic shock in cats. Since plasma cathepsin D is derived chiefly from liver and small intestine during hemorrhagic shock, the above results implicate that anisodamine exerts protective effects on intestinal mucosal cells, most probably, through stabilization of its lysosomes from releasing enzymes during splanchnic ischemia.
Five h after administration of35S-malathion (30 μCi) to rats, the amount of total radioactivity and that bound to macromolecules in various tissues were determined. It was found that the amount of bound radioactivity was distributed in the liver > spleen > kidney > lung > brain, while the amount of total radioactivity in the spleen > kidney > liver > lung > brain respectively. In the subcellular fraction, bound radioactivity was predominantly distributed in microsome, and less frequently in nuclei, cell debris, and mitochondria. Small amount was found in supernatant. After rats had been pretreated with phenobarbital, the amount of bound radioactivity in microsome increased significantly.
The results in vitro studies suggested that the amount of bound radioactivity varies with the reaction time and the concentration of microsomal protein in the incubation mixture. The amount of bound radioactivity decreased when NADPH was absent or microsomes were preheated (at 90°Ctot 10 min) or high concentration of unlabelled malathion was added to the incubation mixture.
From the above it can be seen that the binding of malathion to tissue macromolecules is mediated by a cytochrome P-450 linked MFO system. It is likely that the MFO converts malathion into chemically activated material(s) which subsequently binds to tissue macromolecules.
In 10 von 126 Leberbiopsieproben wurde mittels direkter Immunenzym-Methode Delta-Antigen nachgewiesen. Das beweist, daß die Delta-Agens-Infektion in China tatsächlich vorkommt. Die Delta-Antigen-positiven Patienten gehörten alle zu der Gruppe der chronischen Virus-B-Hepatitiden, sie zeigten aber keine Geschichte von Drogensucht. Delta-Antigen war negativ im Lebergewebe von 14 Patienten mit akuter Hepatitis und 15 Patienten mit HBsAgnegativen Leberkranken. Die Häufigkeit der Delta-Agens-Infektion war 10 % bei 96 Patienten mit chronischer Virus-B-Hepatitis.
Die Synthese der HBV-Antigene wird durch Superinfektion mit Delta-Agens gehemmt. HBcAg im Lebergewebe wurde bei uns nur bei 8 von 10 Delta-Antigen-positiven Fällen gefunden.
Obwohl die Häufigkeit der Delta-Agens-Infektion in China den beschränkten Daten nach nicht sehr hoch ist, dürfte man sie nicht übersehen, da nach Superinfektion mit Delta-Agens die durch HBV verursachte Leberschädigung progressiv weiterschreitet.