Inhibition of sensitized leukocyte's in vitro reactivity by circulating immune complexes in prostate cancer

Summary Circulating immune complexes in the sera of patients with confirmed histological diagnosis of carcinoma of the prostate, were found to interfere in the sensitized leukocyte's in vitro reactivity to prostate cancer associated antigen as evaluated by tube leukocyte adherence inhibition assay, thereby suggesting an inhibitory role of such serum factors in host's anti tumor cell mediated immune responses.4 November 1986     

Inhibition by testosterone of immune reactivity and of lymphoid regeneration in irradiated and marrow reconstituted mice

Zusammenfassung Nachweis, dass die Behandlung letal bestrahlter und mit isologem Knochenmark regenerierter Mäuse mit Testosteron zu starker Herabsetzung der immunologischen Reaktivität und zu eindeutiger Reduktion des lymphatischen Gewebes führt.

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Acknowledgements: This investigation was supported by a grant from the Scientific Research from the Japanese Ministry of Education.     

Chemotaxis of rabbit macrophages in vitro: Inhibition by drugs

Summary Chemotaxis of rabbit macrophages was inhibited in vitro by phenylbutazone and sodium salicylate, but not by other antiinflammatory agents. Other inhibitory compounds were colchicine, vincristine, PHA, Con A, iodoacetic acid, cytochalasin B, and EDTA. Some of these in vitro results contrast apparently with in vivo effects.     

Immunogenicity of agarose-immobilized immune complexes

Summary A novel method is described for production of heterologous antisera to a specific tumor-associated murine antigen by immunization with agarose-trapped immune complexes.     

Cross-presentation of IgG-containing immune complexes

IgG is a molecule that functionally combines facets of both innate and adaptive immunity and therefore bridges both arms of the immune system. On the one hand, IgG is created by adaptive immune cells, but can be generated by B cells independently of T cell help. On the other hand, once secreted, IgG can rapidly deliver antigens into intracellular processing pathways, which enable efficient priming of T cell responses towards epitopes from the cognate antigen initially bound by the IgG. While this process has long been known to participate in CD4⁺ T cell activation, IgG-mediated delivery of exogenous antigens into a major histocompatibility complex (MHC) class I processing pathway has received less attention. The coordinated engagement of IgG with IgG receptors expressed on the cell-surface (FcγR) and within the endolysosomal system (FcRn) is a highly potent means to deliver antigen into processing pathways that promote cross-presentation of MHC class I and presentation of MHC class II-restricted epitopes within the same dendritic cell. This review focuses on the mechanisms by which IgG-containing immune complexes mediate such cross-presentation and the implications that this understanding has for manipulation of immune-mediated diseases that depend upon or are due to the activities of CD8⁺ T cells.     

Effects of antigen on in vitro cultures of sensitized peritoneal cells

Résumé On a ajouté des antigènes aux cultures in vitro des cellules mononucléaires obtenues du péritoine des 3 groupes de cobayes, le premier étant normal, le deuxième présentant une sensibilité immédiate et le troisième une hypersensibilité retardée à la tuberculine ou à l'ovalbumine. L'addition de l'antigène spécifique aux cultures des cellules obtenues des cobayes avec hypersensibilité retardée a provoqué la formation de cellules avec 2 ou plusieurs noyaux. Ceci suggère une relation étroite entre l'hypersensibilité retardée et la formation de cellules multinucléaires.     

Cerebrospinal fluid immune complexes in multiple sclerosis

Summary Using a C 1q binding test, immune complexes have been detected in one half of cerebrospinal fluid samples from patients with multiple sclerosis. These results provide additional evidence for the participation of an immune reaction in the disease process.     

Inhibition of the growth of cariogenic bacteria in vitro by plant falvanones

Phytoalexins, defensive compounds produced by plants against microbial infections, were purified fromSophora exigua (Leguminosae) and their growth inhibitory effects on oral cariogenic bacteria were determined in vitro. Among three isolated compounds, 5,7,2,4-tetrahydroxy-8-lavandulylflavanone completely inhibited the growth of oral bacteria including primary cariogenic mutans streptococci, other oral streptococci, actinomycetes, and lactobacilli, at concentrations of 1.56 to 6.25 g/ml.     

Inhibition of in vitro RNA synthesis by hycanthone,oxamniquine and praziquantel

Summary The schistosomicides, hycanthone, oxamniquine and praziquantel, were found to inhibit the in vitro RNA synthesis using isolated hamster liver nuclei. Preincubation of the nuclei with these drugs revealed that the inhibitory effect of oxamniquine was irreversible and progressed with time, whereas that of hycanthone and parziquantel was reversible. On the other hand, hycanthone and praziquantel have a high affinity for DNA but oxamniquine does not. The data indicate that the mechanism of inhibition by oxamniquine is different from that of hycanthone and praziquantel.     

Cerebrospinal fluid immune complexes in multiple sclerosis.

Using a C1q binding test, immune complexes have been detected in one half of cerebrospinal fluid samples from patients with multiple sclerosis. These results provide additional evidence for the participation of an immune reaction in the disease process.     

Survival of docetaxel-resistant prostate cancer cells in vitro depends on phenotype alterations and continuity of drug exposure

We evaluated in vitro the effect of paclitaxel and docetaxel on PC-3 and DU-145 prostate cancer cell lines to understand better the downstream events in drug-induced tumor cell death. Taxane treatments of DU-145 cells induced rapid cell death by apoptosis, but in PC-3 cells, treatments achieved growth arrest, followed by extensive karyokinesis resulting in multinucleation, giant-cell formation and delayed cell death. To determine if the giant multinucleated cells were able to produce proliferating and drug-resistant survivors, we first delineated the kinetics of drug activity and cytotoxic dose range. Analysis of both lines by colorimetric and cell viability assays demonstrated improved cytotoxicity of taxanes applied continuously. Selected doses and schedules of docetaxel were used to induce giant multinucleated cells that gave rise to docetaxel-resistant survivors, which remained sensitive to paclitaxel and other chemotherapeutics. Growth and morphology of the recovered clones was similar to parental cells. The resistant phenotype of these clones determined by immunofluorescence and immunoblot was associated with transient expression of the β-tubulin IV isoform and was independent of P-glycoprotein, bcl-2 and bcl-xL. Resistant clones will be useful to model progression of resistance to taxanes and to identify unknown and clinically important molecular mechanisms of cell death and resistance. Received 15 March 2002; received after revision 25 April 2002; accepted 27 May 2002     

Inhibition of in vitro RNA synthesis by hycanthone, oxamniquine and praziquantel.

The schistosomicides, hycanthone, oxamniquine and praziquantel, were found to inhibit the in vitro RNA synthesis using isolated hamster liver nuclei. Preincubation of the nuclei with these drugs revealed that the inhibitory effect of oxamniquine was irreversible and progressed with time, whereas that of hycanthone and praziquantel was reversible. On the other hand, hycanthone and praziquantel have a high affinity for DNA but oxamniquine does not. The data indicate that the mechanism of inhibition by oxamniquine is different from that of hycanthone and praziquantel.     

Lymphocyte reactivity in Imuran-treated guinea-pigs and in vitro effect of colchicine

Summary Imuran treatment significantly diminished macrophage migration inhibition in immunized guinea-pigs and the percentage of E-rosette forming cells in all treated animals. 10^–6 M colchicine in vitro significantly increased the percentage of E-rosette forming cells in Imuran-treated animals. The results suggest possible alteration of the lymphocyte receptors after treatment with Imuran.This work was supported by the grants of the Republic Research Fund of Serbia.     

Inhibition of phosphodiesteras by dihydroergotamine and hydergine in various organs of the cat in vitro

Zusammenfassung Die Hemmung der cAMP-Phosphodiesterase in verschiedenen Organen der Katze durch Hydergin und DHE wurde in vitro bestimmt. In Konzentrationen von 10^–4 M bis 10^–6 M wurde ein Hemmeffekt nur im Gehirn beobachtet. Diese Wirkung wird besonders deutlich, wenn man das infolge der Enzymhemmung nicht umgesetzte cAMP berechnet.     

Inhibition by syngenic erythrocytes of in vitro growth of colonics from murine bone marrow cells

Summary The growth of colonies from murine bone marrow cells in soft agar cultures was found to be inhibited by 0.1 ml or more 50% washed syngenic erythrocyte suspension per 1.2 ml culture volume.     

Sonic Hedgehog signaling in advanced prostate cancer

The Hedgehog family of growth factors activate a highly conserved signaling system for cell-cell communication that regulates cell proliferation and differentiation during development. Abnormal activation of the Hedgehog pathway has been demonstrated in a variety of human tumors, including those of the skin, brain, lung and digestive tract. Hedgehog pathway activity in these tumors is required for cancer cell proliferation and tumor growth. Recent studies have uncovered the role for Hedgehog signaling in advanced prostate cancer and demonstrated that autocrine signaling by tumor cells is required for proliferation, viability, and invasive behavior. The level of Hedgehog activity correlates with the severity of the tumor and is both necessary and sufficient for metastatic behavior. Blockade of Hedgehog signaling leads to tumor shrinkage and remission in preclinical tumor xenograft models. Thus, Hedgehog signaling represents a novel pathway in prostate cancer that offers opportunities for prognostic biomarker development, drug targeting and therapeutic response monitoring. Received 18 August 2005; received after revision 30 September 2005; accepted 1 November 2005     

Inhibition of aldosterone synthesis induced by flow-stop in the Mongolian gerbil adrenal gland superfused in vitro

Stopping of superfusion flow for short periods resulted in a significant accumulation of aldosterone within the Mongolian gerbil adrenal gland superfused in vitro. Aldosterone amounts in the first 2-min samples after the re-starting of superfusion were positively correlated with the length of flow-stop; however, they were significantly lower than calculated amounts: 5-min stop: 37 +/- 1% inhibition, 10-min stop: 51 +/- 1% inhibition. In addition, aldosterone secretion was significantly suppressed during prolonged incubation. The results suggest that aldosterone and glucocorticosteroid amounts in adrenal tissue may modulate basal corticosteroidogenesis and that self-suppression forms an important part of the control mechanisms involved in corticosteroidogenesis.     

Inhibition of endotoxin-induced platelet agglutination,histamine and serotonine releasein vitro by thiol-compounds

Zusammenfassung Es wird festgestellt, dass gewisse Thiolverbindungen wie Cystein, Mercaptoethanol, Thioglycolsäure und AET die von Endotoxin ausgelöste Thrombocyten-Agglutination, die Freisetzung von Histamin und Serotonin im Kaninchen-Thrombocytenplasma hemmen.