Leukozytenemigrationsfördernde Wirkung von Crotonöl

Summary Various croton oil fractions were studied with regard to theirin vitro effect on leucocytes and their irritative action. It was discovered that there exist fractions exerting a stimulating effect on leucytic migration and an irritative action and other fractions having a leucocytic stimulating effect without pronounced irritative action. The co-carcinogenic fractions ofDanneel have no promotory effect on the migration of leucocytes.     

Effect of acetylcholine on melanophores ofRana tigrina

Summary Acetylcholine produced melanin aggregation and blanching of skin colour inRana tigrina, the common Indian frog. The effects were more prolonged in frogs pretreated with an anticholinesterase agent. Acetylcholine effects were not antagonized by eitherm-cholinolytic (atropine) orn-cholinolytic (pentolinium) agents, but were markedly inhibited by procaine. The results have been discussed in the light of the well-known membrane-stabilizing effect of procaine.     

Effect of hormones on adenyl cyclase activity of rabbit mammary gland in vitro

Summary Ovarian hormones namely-estradiol and progesterone were observed to stimulate the activity of adenyl cyclase of the mammary gland from pregnant rabbit in vitro, unlike the lactating tissue where it was inhibited. On the other hand, non-ovarian hormones like hydrocortisone, prolactin and insulin did not have a similar effect on this enzyme.Acknowledgement. We are indebted to Dr D. Sundaresan, for his kind encouragement in this study.     

Effects of plant lectins on cellular defense reactions of ascidian hemocytes

The effects of plant lectins on the three cellular defense reactions of hemocytes of the solitary ascidian,Halocynthia roretzi (hemocyte aggregation, phagocytosis, and an allogenic reaction), were investigated. Concanavalin A inhibited aggregation, while wheat germ agglutinin and ricin inhibited the allogenic reaction. Neither of the lectins showed inhibitory effects on phagocytosis, but ricin promoted phagocytosis. These effects of the lectins were diminished by the addition of sugars specific for the respective lectins. These results strongly suggest that different surface carbohydrates are involved in the recognition mechanisms of threeH. roretzi cellular defense reactions.     

Necrosin und die Leukozytenphagozytose

Summary The euglobulin fraction necrosin, prepared according toMenkin from pleural exudates of dogs, strongly inhibitsin vitro bacterium phagocytosis by leucocytes obtained from the abdominal cavity of rats. Depending on the concentration, the average effect amounts to 18–35%. Necrosin has a similar effect (21–38%) on the circulating leucocytes of the dog. The euglobulin fraction prepared by the same method from the serum of untreated dogs has but a slight inhibitory effect on leucocyte activity.     

Die Wirkung der Lipoid- und Polysaccharid-Komponente endotoxischer Lipopolysaccharide gram-negativer Bakterien auf die Leukozytenkultur

Summary Highly purified lipopolysaccharides derived from gramnegative bacteria (endotoxins) stimulate the migration of leucocytes from cultures of chick leucocytes. This effect, as well as many endotoxic manifestations of the preparationsin vivo (pyrogenicity, toxicity, etc.), is induced by their lipid fraction (lipid A), while the respective species-specific polysaccharide functions as lyophilizing carrier which, fundamentally, can be substituted by other inert carriers (e.g. protein).     

Hemmung der durch Proteuslipopolysaccharide gesteigerten Leukozytenemigration in vitro durch antiinflammatorische Corticosteroide

Summary The migration of leucocytes from the buffy coat of chicken blood is slightly but irregulatly inhibited by cortison. If migration of leucocytes is increased by proteus lipopolysaccharide, cortison in concentrations of 10^–4–10^–6, and other anti-inflammatory steroids, produce a pronounced and constant inhibition of leucocytic migration.     

Production of the lymphokine,macrophage aggregating factor,is not inhibited by histamine

Summary Unlike the previously reported inhibitory effect of histamine on the production of the lymphokine, migration inhibitory factor, histamine did not inhibit the production of macrophage aggregating factor (MAgF). By contrast, both prostaglandin E₂ and hydrocortisone inhibited MAgF production, in a dose-dependant manner.     

Die Wirkung von Demecolceinamiden an Zellenin vitro

Summary A series of demecolceinamids was examinedin vitro on chicken fibroblasts, leucocytes, and different bacteria. It was found that with increasing length of the side chain on ring C the antimitotic activity is decreasing while the antibacterial effect is increasing.     

Avoidance of competition by spruce bark beetles,Ips typographus andPityogenes chalcographus

Bark beetles,Ips typographus andPityogenes chalcographus, attracted by synthetic or natural pheromone to Norway spruce logs,Picea abies, preferred to colonize uninfested logs rather than logs occupied by these beetles, probably as a means of avoiding intra-and interspecific competition. The aggregation pheromone components ofP. chalcographus, chalcogran and methyl (E, Z)-2,4-decadienoate, inhibited the attraction response ofI. typographus to its pheromone components (methyl butenol andcis-verbenol), while the converse was not true. However, verbenone released from colonized bark inhibited pheromonal response ofP. chalcographus.     

Die lokale Leukozytenreaktion bei der intraperitonealen Infektion der Maus mitE. coli

Summary Intraperitoneal aggregation of leucocytes is produced in an identical manner by intraperitoneal application of different amounts of living and dead bacteria and bacterial products. The maximum accumulation occurs with medium dosages of bacteria or their products, with high dosages no leucocytic accumulation is produced. Pretreatment with selected LPS of bacteria enhances the intraperitoneal accumulation of leucocytes also with the high amounts of bacteria, whereas the reaction in not pretreated with LPS is suppressed. Parallel to the increase of the intraperitoneal leucocytic accumulation the animals are protected against the infection with high amounts of bacteria, to which they succumb if not pretreated with LPS.     

Studies on the activity of phorbol myrystate acetate on the human polymorphonuclear leukocytes.

Phorbol myrystate acetate (PMA) activates nitroblue tetrazolium reduction in human polymorphs. The activation is inhibited by dibutyryl cyclic AMP, theophylline and phenylbutazone, but is not influenced by hydrocortisone in vitro, nor is it inhibited by leukocytes from patients treated with prednisone. Peptide analogues of Tuftsin also had no effect on this stimulatory activity. We conclude that the action of PMA on the nitroblue tetrazolium reduction is mediated through cyclic nucleotides.     

Studies on the activity of phorbol myrystate acetate on the human polymorphonuclear leukocytes

Summary Phorbol myrystate acetate (PMA) activates nitroblue tetrazolium reduction in human polymorphs. The activation is inhibited by dibutyryl cyclic AMP, theophylline and phenylbutazone, but is not influenced by hydrocortisone in vitro, nor is it inhibited by leukocytes from patients treated with prednisone. Peptide analogues of Tuftsin also had no effect on this stimulatory activity. We conclude that the action of PMA on the nitroblue tetrazolium reduction is mediated through cyclic nucleotides.     

Der Einbau von35S in die Kostalknorpel von Meerschweinchen unter Einfluss verschiedener Glucocorticoide

Summary The uptake of³⁵S, in the chondroitin sulfate of the costal cartilage of guinea pigs, is inhibited by cortisone, methyl-prednisolon, triamcinolon, and dexamethason. No inhibition could be seen under the influence of the natural adrenal hormone hydrocortisone and its nearest relation, prednisolon.     

Die Wirkung der Nukleinsäuren auf die Bakterienphagozytose der Leukozyten

Summary Sodium ribonucleinate and sodium desoxyribonucleinate increasesin vitro the phagocytosis of surviving rat's leucocytes. The average figure for the effect is greater than the limits of error, even in dilutions of 1:100,000. In dilutions of 1:10,000, the action is more striking, the results being 33% and 29% respectively above the control value.     

Die Beeinflussung der Leukozytenphagozytose mit Phlorrhizin

Summary In the rat the intraperitoneally administered phlorrhizin significantly reduces the phagocytosis of bacteria by leucocytes, as determined by thePlatonow-Ludány-Vajda method, with the mean decrease being — 33.5%. The effect is reversible. The phenomenon appears to be due to an alteration of carbohydrate metabolism in the leucocytes. The experiments supply new evidence supporting the view that alongside biophysical factors (surface effects) also cellular metabolic processes may play important roles in the phagocytotic activity of leucocytes.     

Platelet aggregation and stimulation of leucocyte procoagulant activity by rickettsial lipopolysaccharides in rabbits and in man

Summary The effects in vitro of 4 purified lipopolysaccharide (LPS) preparations from Rickettsiae on platelets and leucocytes were studied in rabbits and in man. All LPS induced aggregation in rabbit platelet-rich plasma but to differing degrees. This activity was abolished by inactivation of complement. None of the preparations induced aggregation of human platelets. Both rabbit and human leucocytes, when incubated with each of the rickettsial LPS preparations, generated a potent procoagulant activity (tissue factor). These findings add further support to the concept that rickettsial LPS behave as typical LPS from gram-negative bacteria and may be relevant to the understanding of the mechanism(s) responsible for triggering intravascular coagulation in rickettsial diseases.     

Inhibited hormonal induction of hepatic phosphoenolpyruvate carboxykinase in poly I∶C treated mice,an endotoxin-like glucocorticoid antagonism

Summary Corticosteroid induction of mouse hepatic phosphoenolpyruvate carboxykinase was inhibited by prior injection of poly IC. Mice challenged with a lethal dose of endotoxin 4 h after administration of poly IC could not be protected by a concurrent injection of hydrocortisone.This investigation was supported by U. S. Public Health Service research grant No. AI-10087 from the National Institute of Allergy and Infectious Diseases.     

Der Hyaluronsäuregehalt und die «Hyaluronidase»-Aktivität der Leukozyten

Summary The hyaluronic acid content of leucocytes from the peritoneum of rats shows a significant concentration when measured either turbidimetrically or oxydimetrically, the average value calculated for wet weight being 0.7–0.8%. The hyaluronic acid break down capacity of the leucocytes is not a specific enzyme action but can be attributed to their high ascorbic acid content. The phenomenon has no well defined pH or temperature optimum and can be inhibited by oxine and by semicarbazide.     

Hydrolysis of human leucocyte phospholipids by snake venoms

Résumé Les phospholipases A des venins du serpentVipera palestinae et duNaja naja ne clivent pas des phospholipides de leucocytes intacts, sauf en présence d'un facteur lytique se trouvant dans le venin deNaja naja. L'activité des phospholipases des deux venins sur les leucocytes endommagés n'est pas la même.