Metrological Protocols for Reaching Reliable and SI-Traceable Size Results for Multi-Modal and Complexly Shaped Reference Nanoparticles.

The study described in this paper was conducted in the framework of the European nPSize project (EMPIR program) with the main objective of proposing new reference certified nanomaterials for the market in order to improve the reliability and traceability of nanoparticle size measurements. For this purpose, bimodal populations as well as complexly shaped nanoparticles (bipyramids, cubes, and rods) were synthesized. An inter-laboratory comparison was organized for comparing the size measurements of the selected nanoparticle samples performed with electron microscopy (TEM, SEM, and TSEM), scanning probe microscopy (AFM), or small-angle X-ray scattering (SAXS).

The immunomodulator OM-89 induces ACTH and glucocorticoid secretion in rats through an IL-1 dependent pathway.

The immunomodulator OM-89 (bacterial extract from E. coli), known to act on the immune system by modulating both humoral and cellular responses, significantly increases ACTH and glucocorticoids secretion in normal Wistar rats. A comparative administration of IL-1 displays a similar pattern of release.

Absorption kinetics of a 14C-labelled Escherichia coli extract after oral administration in mice.

The fate of orally administered total 14C-labelled Escherichia coli extract (TEC, OM-89) was compared to that of its major 14C-labeled high molecular weight fractions (HEC, > 30 kD) in mice. High molecular weight substances (> 30 kD) were observed in blood 1 h after oral administration of the products, TEC and HEC. This suggests absorption from the digestive tract of the total E.

In vivo study of the immunomodulating activity of OM-85 using the plaque-forming cells technique (PFC) in mice.

The activity of increasing oral doses of the bacterial extract OM-85 was determined by using the plaque-forming cells assay in mice. The results showed that the oral administration of OM-85 significantly increased the number of splenic antibody-secreting cells against sheep red blood cells (antigen) compared with controls. A maximal response was reached between 400 and 800 mg/kg body weight, and was reproducible with the different batches of OM-85 used.

Action of a mycotoxin (diacetoxyscirpenol) on the immune response of the mouse--interaction with an immunomodulator (OM-89).

The action of diacetoxyscirpenol (DAS)--a mycotoxin that belongs to the family of trichothecenes--on the immune system of the mouse was investigated. Two experimental models were used: 1) bacterial infection with Salmonella typhimurium and 2) the PFC (plaque-forming cells) test on the splenic lymphocytes of the mouse. The results obtained showed that these were dependent on the chronological order of the administration of DAS.

Influence of a bacterial extract on antigen presentation and protection against experimental infections.

Although substances known as immunodulators are usually used to stimulate nonspecific immunity, their mode of action is not well understood. In an effort to clarify this mechanism, we investigated the effect of a lyophilized bacterial extract (Broncho-Vaxom) on experimental infections, on normal or irradiated mice, and on antigen processing.

Studies on the hexose region of the lipopolysaccharide from a low virulence strain of Salmonella typhimurium.

The structure of the hexose region of the lipopolysaccharide from M206 strain, a mutant of Salmonella typhimurium having reduced virulence, was partially determined. Immunological tests indicated cross-reactions of anti-(M206) antiserum with wild-type C5 and Ra mutant strains. Data obtained on chemical composition, periodate oxidation, acetolysis, methylation and analysis by gas chromatography/mass spectrometry show that M206 type lipopolysaccharide contains the common core polysaccharide of Salmonella which was substituted in position 4 of the subterminal glucose unit by a disaccharide: D-glucosyl 1----3 D-galactose.

Immunomodulation in offspring mice after neonatal immunostimulation of mothers or newborn mice.

Mothers of offspring Balb/c mice were stimulated after birth by two substances, a bacterial lysate (LAB) and a chemical, diethyldithiocarbamate (DETC). Anti-sheep red blood cell (SRBC) antibodies were studied after immunization of stimulated mothers or offspring. An increase of anti-SRBC was observed in LAB-stimulated mothers, but these antibodies were decreased in their offspring before weaning.

[Destruction and cutaneous decontamination of diacetoxyscirpenol (mycotoxin from the trichothecene group) by sodium hypochlorite].

Sodium hypochlorite was used to suppress diacetoxyscirpenol cutaneous toxicity; mice skin can be decontaminated with "Eau de Javel" (1 p. 100 free chlorine) if application is performed less than 15 min. after contact with toxin.

Role of the polysaccharide and of the lipopolysaccharide in the immunoprotective capacity of Klebsiella pneumoniae ribosomes.

Ribosomes, ribosomal RNA (r-RNA), capsular polysaccharide (PS-K) and lipopolysaccharide (LPS) were isolated and purified from Klebsiella pneumoniae, type I. The protective capacity of these different fractions was investigated in function of their analytical composition. The results show that ribosomes, and in particular, ribosomal RNA have the greatest protective activity at the lowest concentrations.

Effect of microwave irradiation (2450 MHz) on murine cytotoxic lymphocyte and natural killer (NK) cells.

Male Balb/c mice were exposed in an anechoic chamber to 2450 MHz CW microwaves at 5, 10, 15, and 20 mW/cm2, 4 hours daily for 4 days, under controlled environmental conditions. T-cell cytotoxicity and natural killer (NK) cell activity were compared in exposed and sham animals. A significant decrease (p less than 0.

[Determination of the virucidal activity of antiseptics by a gel filtration method].

The authors propose a method for determining the virucidal potency of antiseptics, in which separation of antiseptic from virus is achieved by filtration through a gel of Sephadex LH20. The antiseptic is trapped within the gel while the virus passes through. Thus, the cytotoxic effect of the antiseptic, which usually hinders virus titration, is eliminated.

[Vaccination using Salmonella typhimurium Rc in protein-deprived BALB/c mice].

Four-week old BALB/c mice were fed a 4% protein diet for 6 weeks. At the 3rd week of undernourishment, they were orally vaccinated with a live vaccine, Salmonella typhimurium Rc. the mice were challenged 3 weeks after vaccination, and malnutrition was discontinued at that time.

[Effect of temperature on diacetoxyscirpenol production and on sporulation in a liquid culture of Fusarium sambucinum].

F. sambucinum grown for 14 days on peptone supplemented Czapek medium produced higher amount of diacetoxyscirpenol at + 15 degrees C than at + 25 degrees C or at temperature kept successively at + 15 degrees C (day) and + 5 degrees C (night). There was no correlation between the spores number and the toxin level, but toxin synthesis began only with sporification and then continued until the 14th day.

Changes in ecto-5'-nucleotidase activity during early stages of vesicular stomatitis virus infection. Effects of concanavalin A.

Study of ecto-5'-nucleotidase was performed in cultured epithelial cells, infected with vesicular stomatitis virus (VSV). Changes in the enzymatic activity were measured in terms of TCID50 and exposure time. The effects of an enzyme inhibitor, Con A, were also investigated during the interaction between virus and cells.

[Study of the transfer of immunostimulation from the mother to the young mouse using 2 immunostimulants and the PFC test].

Pregnant Mice were stimulated with two substances, an antibronchitic lysate (LAB) and diethyldithiocarbamate (DTC). PFC response was studied in mothers and their offspring for 6 weeks after birth. An increase in PFC response was noted in the immunostimulated adult Mice.

Antiinflammatory and immunostimulant activities of six sulphur compounds--four benzenesulphonates, levamisole, and pyritinol hydrochloride--assayed in mouse cell activation studies.

The effect of a phlogogenic agent and of six sulphur compounds on peritoneal macrophages, spleen B lymphocytes, and von Kupffer cells of the liver has been observed in BALB/C mice. The phlogogenic agent (0.5% carrageenin + 10% peptone) was a potent stimulant of the macrophages (increasing their number, protein content, and acid phosphatase activity), the lymphocytes (increase of haemolytic plaque counts), and the von Kupffer cells (increase of the colloidal carbon clearance rate which measures phagocytic capacity).

[Thymosin-testosterone interaction in spontaneous rosette formation in the baboon monkey (Papio papio)].

Thymosine fraction V was shown to exert a stimulation activity on T lymphocytes from Papio papio, as determined by E. Rosette and active E. Rosette formation.

[Experimental infection of mice by Salmonella typhi inoculated orally: influence of immunosuppressive therapy].

Various immunosuppressive treatments were used in order to induce a Salmonella typhi infection in mouse by oral route. Neither low protein diets nor administration of mucin, iron, streptomycin or silica could modify animal's sensitiveness, but, cyclophosphamide injections enhanced lethal effect of bacteria, while silica increased the number of bacteria in the blood and the spleen.

[Release of hepatitis A virus into the culture medium, during its replication in PLC/PRF/5 cells].

Hepatitis A virus (HAV), obtained from human feces collected 3 days after the onset of jaundice, was propagated in human hepatocarcinoma cells (PLC/PRF/5). In the course of 5 passages, it was released into the supernatant without cytopathic effect. Released HAV was propagated after inoculation into PLC/PRF/5 cells.

Secondary immune response to oral and nasal rough mutant strains of Salmonella typhimurium.

The variations in anti-Salmonella typhimurium antibody levels was measured in BALB/c mice which had been orally and nasally vaccinated with S. typhimurium live mutants of different lipopolysaccharide lengths. Together with the demonstration of immunological memory, the intensity of the secondary response was correlated with the length of the polysaccharide chain at intestinal and serum levels.

An attempt to localize the vaccinating power of Klebsiella pneumoniae ribosomal preparations using saccharose-gradient ultracentrifugation.

The study of the vaccinating power of ribosomal vaccines against Klebsiella pneumoniae led us to define the chemical nature which supports this protective activity. We tried to separate this support and the ribosomes by sucrose gradient ultracentrifugation. We isolated high protective membrane vesicles by this technique applied to salt-washed ribosomal preparations.

[Study of experimental vaccine protection using a statistical method to compare survival curves].

A statistical method using the chi 2 distribution of variable was studied for survival data about experimental disease on S. typhimurium C5S infected mice via oral administration, and about vaccinal protection with S. typhimurium mutants.

Study of the mode of action of ribosomal vaccines from Klebsiella and Streptococcus pneumoniae and their ribonucleic and protein fractions using passive immunization.

The vaccinating potency of ribosomal fractions of Klebsiella pneumoniae and Streptococcus pneumoniae as well as their ribosomal RNA and protein fractions has been studied with respect to their ability to induce cellular or humoral immunity. Experiments with transfer of serum or spleen cells from vaccinated animals have shown that anti-Klebsiella immunity is essentially cellular, while streptococcal immunity is exclusively humoral. Results have been discussed as a function of differential results for the various fractions under study.