Relation between stimulus intensity and neutrophil chemotactic response

Summary The effect of chemotactic peptides which lack chemokinetic activity has been investigated. The neutrophil response is proportional to the logarithm of the stimulus intensity, or alternatively a power function with an exponent of 0.3. Equal responses are obtained for equal ratios between the peptide concentration in the lower compartment and the threshold concentration. The significance of Weber-Fechner's law in leucocyte chemotaxis is discussed.We thank Miss B. Zanolari, Mrs M. Marti, Mrs Hauck and Mr Dietz for excellent technical assistance. This work was supported by the Swiss National Foundation for Scientific Research.     

Ribonuclease activity in leucocytes of hyperimmunized rabbits

Résumé Les leucocytes du sang périphérique de lapins hyper-immunisés contreCoxiella burneti ont été comparé avec des leucocytes de lapins normaux. Par la méthode cytochimique on a pu constater chez les animaux hyper-immunisés un accroissement du taux des leucocytes polynucléaires, l'enzyme ayant une activité accrue ce qui s'accorde avec un titre élevé d'anticorps dans le plasma. L'auteur cherche à déterminer la signification de cette augmentation de l'enzyme chez les animaux hyper-immunisés et de son rapport avec la réaction immunogène.     

Colicin E3 enhances the oxidoreductive activity of guinea-pig leucocytes

Summary Colicin E3 increased the capacity of peritoneal exudate leucocytes to reduce iodo-nitro-tetrazolium-chloride to formazane. This effect was directly dependent on its concentration within the range 10³–10⁵ lethal units per cell. In control experiments, dectran C exerted no influence on the rate of this activity and colicin E3 did not convert INT to formazane.     

Effect of menadione on the phagocytic activity of guinea-pig polymorphonuclear leucocytes

Riassunto Menadione in vitro inibisce l'attività fagocitaria di leucociti polinucleati in aerobiosi e in anaerobiosi. Vengono riportate prove sperimentali dalle quali risulta che l'effetto del menadione non è in rapporto con l'inibizione della glicolisi o con l'attività di trasporto di elettroni nella ossidazione dei piridinnucleotidi ridotti tramite una DT diaforasi.     

Collagenolytic activity from circulating polymorphonuclear leucocytes of patients with asbestosis

Summary Levels of collagenolytic activity produced by circulating polymorphonuclear leucocytes (PMN) of patients exposed to asbestos and patients with asbestosis were found to be similar to those of normal controls.Supported by MRC term grant MT-7310 and IRSSTQ. Reprint requests should be addressed to I.L.     

Drumsticks in the leucocytes of primates

Riassunto La frequenza del «drumstick» nei nuclei dei leucociti polimorfonucleati di diverse specie di Primati è stato riscontrato pressochè simile a quella dell'Uomo.

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The technical cooperation of MissP. Monaci and Mr.V. Puel has been very valuable. — The present research was partially carried out under a grant from the Italian National Council of Research (n.7854/F).     

On the concentration of eosinophile leucocytes

Zusammenfassung Eine Methode zur Anreicherung lebender eosinophiler Leukocyten des Pferdes mit Hilfe einer Gegenstromzentrifuge wird ausgearbeitet. In den angereicherten Suspensionen wurde eine Konzentration von 20 bis 50% erreicht.     

Ikaros negatively regulates inducible nitric oxide synthase expression in macrophages: Involvement of Ikaros phosphorylation by casein kinase 2

Ikaros is known as a critical regulator of lymphocyte development. We examined the regulatory role of Ikaros in LPS/IFN-gamma-induced inducible nitric oxide synthase (iNOS) expression by macrophages. Our results showed that IK6 (Ikaros dominant negative isoform) induction increases the iNOS expression. Ikaros DNA binding activity on the iNOS promoter was decreased, and a mutation of the Ikaros-binding site on the iNOS promoter resulted in an increase in LPS/IFN-gamma-induced iNOS expression. LPS/IFN-gamma increased the histone (H3) acetylation on the Ikaros DNA binding site. These results suggest that Ikaros acts as a negative regulator on iNOS expression. Treatment with a casein kinase 2 (CK2) inhibitor reversed LPS/IFN-gamma-induced decrease in Ikaros DNA binding activity. Moreover, overexpression of kinase-inactive CK2 decreased iNOS expression and a significant amount of CK2alpha1 translocated into the nucleus in LPS/IFN-gamma-treated cells. Overall, these data indicate that LPS/IFN-gamma decreases the Ikaros DNA binding activity via the CK2 pathway, resulting in an increase of iNOS expression.     

A simple method for the collection of leucocytes from rat blood

Zusammenfassung Blutleukozyten von Ratten wurden mit menschlichem (normalem) Serum behandelt. Die Viabilität dieser Präparationen konnte dadurch demonstriert werden, dass die Zellen durch Phytohemagglutinin in «blast» Formen umgewandelt wurden.     

Peroxidase activity of neutrophil granules in two cases of congenital myeloperoxidase deficiency]

The neutrophils and monocytes of two patients with hereditary myeloperoxidase deficiency lacked myeloperoxidase activity as determined by light and electron microscopic cytochemical staining. Using Graham-Karnovsky media, azurophils of neutrophils were devoid of peroxidase whereas all eosinophilic and basophilic granules exhibited normal peroxidase activity. After incubation in alkaline diaminobenzidine media which stains the catalase of microperoxisomes, some small granules were seen to be strongly stained in both immature and mature neutrophils. These small granules were distinct from all other neutrophilic granules which lacked a positive reaction. Only, in the presence of cyanide or aminotriazole, peroxidatic activity was also detected in some ellipsoid azurophils. This observation suggests that these substances activated an oxidase whose nature is discussed.     

Action of Corynebacterium parvum on the activity of glycosidases and proteases of peritoneal macrophages in the mice]

Glycosidase and peptidase of non-treated Mouse peritoneal macrophages were characterized. The enzymatic activities of Corynebacterium parvum stimulated Mouse macrophages were compared to those of macrophages obtained from non-treated animals. All the enzymatic activities, but beta-C-galactosidase, were higher in stimulated Mouse macrophages.