Schutzwirkung von polysaccharidartigen Fraktionen bakterieller Herkunft bei einer experimentellen Virusinfektion

Summary A polysaccharide like substance derived from cultivated bacteria is shown to exert a protective effect in mice infected with SK.-Col. Encephalomyelitis. The effect is optimally produced when the substance is applied previous to the infection. Certain changes in sera treated with the substance are observed involving normal virucidal factors of the sera.     

Spezifische Wirkung einiger tierischer und bakterieller Polysaccharide auf Leucocytenin vitro

Summary Different purified polysaccharides, mucopolysaccharides, phosphatides and carbohydrat-sulfonic acids have been investigated for their effect on stimulation of leucocytic migrationin vitro. The bacterial polysaccharides of proteus,S. marcescens, shiga and shiga fullantigen, have been found to be of high specific activity. All other compounds have much less or no activity. Therefore it might be concluded that the type of bacterial polysaccharides which promote leucocytic migration belong to a highly specific group.     

Abhängigkeit der Leukozytenwanderung und ihrer Steigerung durch Proteuslipo-polysaccharide von der Glucosekonzentration des Milieus

Summary The migration of leucocytes from the buffy coat is influenced by the glucose concentration in the medium, stimulation of migration results from concentrations of glucose up to 2%.. Higher concentrations of glucose up to 8%. have no effect. The stimulating effect of a constant concentration PLPS increases considerably over the whole range of glucose concentrations up to 8%.. Optimal stimulation by PLPS depends therefore on the glucose concentration.     

Über eine Strahlenschutzwirkung von Apresolin und C. 5864-Su (2-Octahydro-1-azocynil-äthyl-guanidin)

Summary Mice exposed to a lethal total-body X-irradiation were partly protected by comparatively small doses of 1-hydrazinophthalazine (Apresoline®), and even smaller ones of [2-(octahydro-1-azocinyl)-ethyl]-guanidine (C. 5864-Su, guanethidine), administered prophylactically. On the other hand, only C. 5864-Su and reserpine, but not Apresoline, afforded protection against organic peroxide intoxication.     

Comparaison de l'activité respiratoire d'Esch. coli pendant la bactériolyse due aux bactériophages de la série T1 à T7

Summary The course of bacteriolysis as determinated by the oxygen consumption of the bacteria is different during bacteriolysis produced by the phagesT _1,3,5,7 as compared with that produced by phagesT _2,4,6. With phagesT _1,3,5,7, the bacteriolysis occurs, rapidly, but incompletely after a latent period. With the phagesT _2,4,6 bacteriolysis occurs slowly and the course of the respiration shows a « plateau » but goes to completion. The biochemical mechanism of the bacteriolysis therefore seems to differ in both cases.     

HIV infection is blocked in vitro by recombinant soluble CD4

The T-cell surface glycoprotein, CD4 (T4), acts as the cellular receptor for human immunodeficiency virus, type 1 (HIV-1), the first member of the family of viruses that cause acquired immunodeficiency syndrome. HIV recognition of CD4 is probably mediated through the virus envelope glycoprotein (gp120) as shown by co-immunoprecipitation of CD4 and gp120 (ref.5) and by experiments using recombinant gp120 as a binding probe. Here we demonstrate that recombinant soluble CD4(rsT4) purified from the conditioned medium of a stably transfected Chinese hamster ovary cell line is a potent inhibitor of both virus replication and virus-induced cell fusion (syncytium formation). These results suggest that rsT4 is sufficient to bind HIV, and that it represents a potential anti-viral therapy for HIV infection.     

Studies of the behaviour of isolated cells in an open system

Summary A computer-aided arrangement was used to study the time function of lactate output of isolated intestinal epithelial cells in an open system. The results indicate better viability of the cells than in a closed system.Supported by grant no. 2134 of the Austrian Fonds zur Förderung der wissenschaftlichen Forschung.     

Extracellular vesicles regulate the human osteoclastogenesis: divergent roles in discrete inflammatory arthropathies

Objective

Extracellular vesicles (EVs) are subcellular signalosomes. Although characteristic EV production is associated with numerous physiological and pathological conditions, the effect of blood-derived EVs on bone homeostasis is unknown. Herein we evaluated the role of circulating EVs on human osteoclastogenesis.

Methods

Blood samples from healthy volunteers, rheumatoid arthritis (RA) and psoriatic arthritis (PsA) patients were collected. Size-based EV sub-fractions were isolated by gravity-driven filtration and differential centrifugation. To investigate the properties of EV samples, resistive pulse sensing technique, transmission electron microscopy, flow cytometry and western blot were performed. CD14⁺ monocytes were separated from PBMCs, and stimulated with recombinant human M-CSF, RANKL and blood-derived EV sub-fractions. After 7 days, the cells were fixed and stained for tartrate-resistant acid phosphatase and counted.

Results

EVs isolated by size-based sub-fractions were characterized as either microvesicles or exosomes (EXO). Healthy (n = 11) and RA-derived (n = 12) EXOs profoundly inhibited osteoclast differentiation (70%, p < 0.01; 65%, p < 0.01, respectively). In contrast, PsA-derived (n = 10) EXOs had a stimulatory effect (75%, p < 0.05). In cross-treatment experiments where EXOs and CD14⁺ cells were interchanged between the three groups, only healthy (n = 5) and RA (n = 5)-derived EXOs inhibited (p < 0.01, respectively) the generation of osteoclasts in all groups, whereas PsA (n = 7)-derived EXOs were unable to mediate this effect.

Conclusions

Our data suggest that blood-derived EXOs are novel regulators of the human osteoclastogenesis and may offer discrete effector function in distinct inflammatory arthropathies.

     

Filtered Backprojection Reconstruction with Depth-Dependent Filtering

A direct filtered-backprojection(FBP) reconstruction algorithm is presented for circular cone-beam computed tomography(CB-CT) that allows the filter operation to be applied efficiently with shift-variant band-pass characteristics on the kernel function.Our algorithm is derived from the ramp-filter based FBP method of Feldkamp et al.and obtained by decomposing the ramp filtering into a convolution involving the Hilbert kernel(global operation) and a subsequent differentiation operation(local operation).The d...