Suppression of intrinsic B-cell function in Dengue-infected mice.

Mice infected with Dengue virus show a depressed immune response to lipopolysaccharide (LPS), a helper T-cell-independent antigen, when LPS was administered on day 0, 6 and 12 post infection. Mice injected with inactivated virus failed to show immunosuppression.     

Enzymatic activity of peritoneal macrophages of Balb C mice after enteral or parenteral stimulation with bacterial extracts]

A study of peritoneal macrophage activation has been conducted by simultaneous investigation in eleven enzymes in Balb/c Mice stimulated with bacterial extracts, by oral and parenteral route. The results showed important changes in Macrophage number and activity. On the other hand this activation depended upon the route of administration, antigen nature, and time interval between stimulation and peritoneal harvesting.     

Effect of lymphokines produced in a grafted system on production of prostaglandins by macrophages]

Mice peritoneal macrophages cultured in vitro release a prostaglandin-like activity as evaluated by a bio-assay using Rat stomach fundus. The prostaglandin release is greatly increased when macrophages are incubated with the supernatant of mixed lymphocyte cultures between recipient and donor of a skin allograft. This phenomenon was found in all strains of Mice tested except C3H/HeJ Mice, a strain already known for its defective responsiveness to bacterial lipopolysaccharide (LPS).     

Effects of diacetoxyscirpenol on experimental candidiasis of mice

A single injection of 4.5 mg/kg of diacetoxyscirpenol (a toxin synthesized by Fusarium) into Mice challenged by C. albicans, increases significantly the development of an experimental candidiasis. Suspensions of homogenized kidneys was spread on Sabouraud dextrose agar plates and the colonies of C. albicans were counted after 24 hrs incubation. The mean values were determined. Comparison of mean values calculated for kidneys from the Mice challenged with C. albicans and those challenged with C. albicans plus toxin gave highly significant results.     

Effect of lead microparticles introduced into the respiratory system of the sensitivity of mice to Pasteurella multocida infection via aerosol]

Lead microparticles, resulting from the pyrolysis of organic lead used as an anti-knock agent in gasoline, were introduced into the lungs of Mice, during a short single exposure. When 6 microgram of lead were retained in the lungs (mean value per Mouse), the phagocytic ability of the pulmonary alveolar macrophages harvested 6 and 18 hrs. later, was significantly reduced. It was observed, in the same conditions, that the resistance of Mice to experimental infection by aerosolized Pasteurella multocida, was significantly reduced. When 3 microgram of lead were retained in the lungs, there was no significant difference between control and intoxicated Mice.     

The effect of continuous exposure to low frequency electric fields on three generations of mice: A pilot study

Summary Mice were allowed to mate, gestate, deliver and rear their offspring for 3 successive generations while being continuously exposed to 60 Hz electric fields. Mice exposed to vertical electric fields exhibited decreased body weights at 35 days postpartum and increased mortality, rates for 3 successive generations. Mice exposed to horizontal electric fields exhibited decreased body weights for 2 successive generations.Supported by grants from National Institute of Health, and the Veterans Administration. Research Service, No. 0865-01.Vibration measurements were performed by Dr.Daniel A. Driscoll, New York State Department of Environmental Conservation.     

The effect of continuous exposure to low frequency electric fields on three generations of mice: a pilot study.

Mice were allowed to mate, gestate, deliver and rear their offspring for 3 successive generations while being continuously exposed to 60 Hz electric fields. Mice exposed to vertical electric fields exhibited decreased body weights at 35 days postpartum and increased mortality rates for 3 successive generations. Mice exposed to horizontal electric fields exhibited decreased body weights for 2 successive generations.     

The effects of a heterologous antibody against a crude lipoprotein lipase fraction in mice]

The antigens contained in a crude lipoprotein-lipase fraction from the Rabbit adipose tissue have no effect on Mice, even after daily injections for several months. But they induce an immune reaction in Sheep, allowing one to produce several immune sera with a high physiological activity, without any specific barrier between Rabbit and Mouse. After total absorption of these immune sera by normal Rabbit serum, the remaining antibodies have an activity against esterasic lipoproteins. Small doses of these antibodies induce in Mice marked hyperplastic and degenerative reactions of the adipose tissue and an extensive lysis of the pancreas. A correlative high lymphocytic activation, producing B and T immunoblasts, is induced.     

Comparison of the production rates of bacteria in the rumen estimated by using labelled live and formaldehyde treated mixed bacterial cells

The bacteria production rates in the rumen have been estimated by injecting 14C- and 35S-labelled mixed rumen bacteria, either live or killed by treatment with formaldehyde, into the rumen and applying isotope dilution technique. The rate of bacteria production when estimated by using either live- or dead-(protected-)labelled bacterial cells were comparable.     

Preparation of specific antiserum against Rana esculenta pre-alpha lens crystallin.

Specific antiserum against Rana esculenta lens pre-alpha crystallin was prepared in a rabbit by injecting antigen-antibody precipitate of this crystallin obtained from immunoelectrophoresis of esculenta total soluble lens proteins against homologous antiserum.     

Enhancement of peritoneal macrophage activity by bovine gamma globulin in mice

Mice treated with bovine gamma globulins showed an increased resistance to Salmonella typhimurium infection. This phenomenon seems to be bound to an increase of peritoneal macrophage phagocytic activity, as shown by the method of chemiluminescence, in experiments performed on peritoneal macrophages from mice treated with bovine gamma globulin.     

Demonstration of nucleotide pyrophosphatase and phosphohydrolase activities in normal lymphocyte of Balb/c mice and absence of these activities in YC8 tumor cells and in lymphocytes of animals with YC8 lymphoma]

Saline extraction of tumor cells from YC8 lymphoma transplanted in Balb/c Mice, of lymphocytes from animals bearing this tumor and of lymphocytes from control animals, allowed us to show important hydrolytic activities towards UDP-[(14C)]-galactose and galactose-[(14C)]-1-phosphate in normal lymphocytes. These activities disappear in lymphocytes from Mice bearing this tumor and in tumor cells themselves.     

Kinetics of decrease and apparent transformation of fluorescence spectra of benzo(a)pyrene absorbed by living cells: case of lymphocytes and macrophages]

A home made microspectrofluorimeter is used in order to follow the decrease of fluorescence intensity of Benzo(a)Pyrene after its absorption by single living cells. The kinetics look to be a first order one; fluorescent metabolite can be detected when peritoneal macrophages of Mice are used but not with human periferic lymphocytes pretreated with mitogens.     

Activity of the principal alkaloids of Polyalthia oliveri Engler (Annonaceac) on the central nervous system and the cardiovascular system]

Polyalthia oliveri leaf alkaloid, oliveroline, shows in Mice antiparkinsonian properties which decrease or disappear with the alkalo?ds extracted from the bark of the trunk, oliveridine and oliverine. The latter alkaloid has an antihypertensive effect which is not found in oliveridine, only hypotensive by a relaxant close to papaverine action on vascular smooth muscles.     

Cytotoxicity of mouse peritoneal cells after alloimmunization]

CBA Mice were immunized by two intraperitoneal injections of 30 X 10(6) DBA/2 or C57BL/6 spleen cells at days--12 and--2. Peritoneal cell population was obtained at day zero by washing the peritoneal cavity of Mice. Adherent cells were then separated using a 2 hrs. incubation in "Falcon" plates followed by washing. This macrophage-rich peritoneal cell population was found nonspecifically cytotoxic against 51Cr labeled tumoral target cells: P815 X DBA/2 mastocytoma cells, EL4 X C57BL/L lymphoma cells and spontaneous lymphoma AKR cells (same H--2k as CBA). This adherent peritoneal cell cytoxicity was demonstrated after 24 hrs. incubation with the target cells. It was found in nonspecific combination as well as when using target cells syngeneic to the donor. These findings suggest that adherent peritoneal cell cytotoxicity could be at least partly due to macrophages and result from factor (s) released by sensitized lymphocytes in vivo in the same way as has been previously demonstrated in vitro.     

Modifications by Nematoda of the sensitivity of mice to Salmonella abortus ovis administered orally or subcutaneously]

Mice inoculated 6 to 9 days previously with Heligmosomoides polygyrus (=Nematospiroides dubius) become more frequently infected than controls after an oral challenge with a constant dose of Salmonella abortus ovis. But parasitism increases the LD 50 when the subcutaneous route of infection is used, probably by stimulating the immune system of the host.     

Lymphatic metastasis of tumour; persistent transport of cells.

A model of lymphatic metastasis established by injecting Walker rat carcinoma cells into the rat footpad was used to study the output of tumour cells from the footpad. The lymphatic efferent from the footpad was cannulated in a group of rats with advanced neoplasm; it was shown that the output of tumour cells was continuous over periods up to 90 min and ranged from 10(2)-10(5) cells/min.     

Transdermal uptake of a peptide hormone: inhibition by calcitonin eardrops of induced osteolysis in guinea-pig ossicles.

In view of a recent proposal that calcitonin injections may arrest the bony pathology of otosclerosis, we have tested the possibility of obtaining locally effective concentrations by giving salmon calcitonin in eardrops. Osteolysis of guinea-pig ossicles induced by injecting parathyroid hormone shortly before explantation was markedly inhibited by 3 days prior instillation of the calcitonin in an aqueous vehicle or in dimethyl sulphoxide, but not by a solution in propylene carbonate.     

Role of Friend-associated lymphatic leukemia virus in immunization against Friend leukemia complex

Summary Mice inoculated with Friend leukemia complex (FLC) pretreated with concanavalin A are resistant to FLC challenge only when they have become infected with the FLC-associated lymphatic leukemia virus (LLV). In interpreting states of resistance to FLC induced by various immunizing procedures, the possibility that immunity is sustained by an unrecognized LLV infection should always be considered.Supported by a grant from the Italian National Research Council.     

Human specific immunoglobulin protects against infection with common Staphylococcus in mice

Mice infected with non-capsulated Staphylococcus aureus strains highly resistant to methicillin survived after the administration of specific immunoglobulin extracted from pooled human sera by using homologous capsular type strains, but no protective effect was shown with a conventional immunoglobulin preparation and methicillin, even with high doses.