Biomedical subjects

J Shani

Publications and source records attributed to J Shani.

173 records · Page 10Linked to original sources

PubMedDate not supplied

The ability of ethanolic extract of propolis (EEP) to protect mice against gamma irradiation.

Ethanolic extract of propolis (EEP) was tested as a protective agent against gamma irradiation in mice. The mice were exposed to 6 Gy gamma irradiation from a 60Co source, and were treated intraperitoneally with EEP, administered before and after their irradiation. While the non-treated mice expired within 12 weeks, the mice that received a series of EEP treatments survived the irradiation, and their leucocyte count as well as their spleens' plaque-forming activity returned to normal. It is suggested that an antioxidant and a free radical scavenger in the EEP are responsible for the radiation protective effect of the extract of this natural product.

Animals↗

PubMedDate not supplied

Antitumoral property of ethanolic extract of propolis in mice-bearing Ehrlich carcinoma, as compared to bleomycin.

Antitumoral effect of ethanolic extract of propolis (EEP) was demonstrated in mature mice-bearing Ehrlich carcinoma. Survival rate after EEP treatment was compared to that of bleomycin, given alone or in combination every two days for 36 days and followed up for 14 additional days. The survival rate at 50 days was 55% after EEP and 40% after bleomycin, while all the mice-treated with EEP + bleomycin combination demonstrated shorter survival than the controls. It is concluded that while the in vivo activity of bleomycin is reduced in the presence of cytochrome-C-reductase inhibitors (like some of the EEP components are), the antitumoral property of EEP in the tumored animal model studied is significant and lasting.

Animals↗

PubMedDate not supplied

Modulating luminol-dependent chemiluminescence of neutrophils by flavones.

The effect of 14 flavones on luminol-dependent chemiluminescence of neutrophils was studied in vitro. Chemiluminescence was used in this study as an indicator for the production of a reactive oxygen species by neutrophils, stimulated by phorbol myristate acetate. While flavone-8-acetic acid, and most of the compounds tested, inhibited chemiluminescence, flavone and its 5-hydroxy-7-methoxy derivatives enhanced it by up to 150%. The most active inhibitors of photon emission were the glycosides. These results indicate that lipophilicity and some structural determinants modulate the chemiluminescent capacity of neutrophils.

Animals↗

PubMedDate not supplied

Effect of cinnamic and acrylic acids' derivatives on luminol-enhanced chemiluminescence of neutrophils.

Fourteen derivatives of cinnamic and acrylic acids were evaluated for their ability to modulate chemiluminescence, evoked by neutrophils that had been exposed to luminol and phorbol-myristate-acetate. Compounds with one or two hydroxyl groups on the phenyl ring demonstrated significant inhibition of the chemiluminescence, but this inhibition was diminished by methoxylation. Saturation of the double bond in the aliphatic chain of cinnamic acid at C6-enhanced the chemiluminescence to a small degree. All three acrylic acid derivatives demonstrated a marked inhibition of the luminol chemiluminescence, indicating that characteristics of the heterocyclic ring is of utmost importance in this activity.

Acrylates↗

PubMedDate not supplied

Antitumoral effect of bleomycin+dolomite combination treatment, in mice bearing Ehrlich ascites carcinoma.

Dolomite, a mineral composed of magnesium and calcium carbonates, potentiates the antitumoral activity of bleomycin: While 40 days after inoculation, no mice survived the Ehrlich ascites tumor burden, 44% of them survived it after bleomycin treatment, and 63% after a simultaneous treatment of bleomycin and dolomite. The beneficial antitumor effect of dolomite is probably related to its high content (12.8%) of magnesium.

Animals↗

PubMedDate not supplied

Modulation of cell-mediated immunity by lithium chloride.

Immunomodulation of cell-mediated immunity was studied in mice treated with either lithium chloride (LiCl), anti-CD8 monoclonal antibody or their combination. While 6-day LiCl treatment decreased the ability of their splenocytes to induce a local graft-versus-host reaction--anti-CD8 abolished this effect. The proliferative response of spleen cells from those three groups of mice to concanavalin A stimulation in vitro was significantly increased. The natural killer (NK) cell toxicity of the mice was decreased by over 43% after the 6-day LiCl treatment, but was x 2.5 higher then the control value after a longer 21-d treatment. These results indicate that the immunomodulatory capacity of lithium is dependent on the type of cell population studied, and on the schedule of administration.

Animals↗

PubMedDate not supplied

Correlation between virulence of various strains of mycobacteria and their susceptibility to ethanolic extract of propolis (EEP).

Ethanol extract of propolis (EEP) has antibacterial, antiviral, antiprotozoal and antifungal properties, in addition to many biological effects. Our laboratory has demonstrated a synergistic effect of EEP and antibiotics on the growth of Staphylococcus aureus, and suggested that the bactericidal effect of EEP was expressed mainly on virulent mycobacteria rather than on non-virulent (attenuated) ones. The present study was designed to reconfirm the latter finding, by subjecting 17 different mycobacteria strains to EEP, and evaluating whether there is a correlation between the virulence of the mycobacteria strains studied and their susceptibility to EEP. Our findings demonstrate that while the four non-virulent strains studied are not susceptible to EEP, out of the 13 virulent strains studied seven are susceptible and six are resistant to it. These results suggest that while there is no full correlation between virulence of the mycobacteria tested and their susceptibility to EEP, the few strains that were resistant to EEP were non-virulent.

Ethanol↗

PubMedDate not supplied

Synergism between ethanolic extract of propolis (EEP) and anti-tuberculosis drugs on growth of mycobacteria.

Ethanolic extract of propolis exerts a strong anti-bacterial activity, in addition to antifungal, antiviral and antiprotozoal properties. In previous studies from these laboratories we have demonstrated that the intensity of the bactericidal activity of EEP is correlated with the virulence of the mycobacteria tested, and that EEP has a synergistic effect with antibiotics on growth of staphylococcus aureus. In the present study we investigated whether the same synergism and correlation exists between EEP and some anti-tuberculosis drugs on tuberculosis mycobacteria with different degrees of virulence. Six standard strains and 11 wild strains of mycobacteria were exposed for 30 days to EEP, with or without streptomycin, rifamycin, isoniazid or ethambutol. Out of the 17 strains, 8 were resistant to at least two standard antibiotics, and were considered "multi-resistant strains". The rest were either susceptible or resistant to only one of the antimycobacterial drugs. Antagonism was recorded only in one case, when Staphylococcus aureus were treated with a mixture of EEP and ethambutol, suggesting that a chemical bond could have been formed between this anti-tuberculosis antibiotic and one of the active components of the ethanol extract of propolis.

Antitubercular Agents↗

PubMedDate not supplied

Endogenous prolactin maintains its own binding sites in the pigeon crop sac mucosa.

The specific binding of lactoperoxidase-labelled 125I-labelled ovine prolactin was determined in a membrane particulate of the pigeon crop-sac mucosal epithelium. Binding was found to be dependent upon the particulate preparation used, its protein concentration and the length of the incubation at 5 degrees C. Scatchard analysis of the binding to crop-sacs from saline or prolactin-injected (1.9 microgram per pigeon) revealed that prolactin stimulated 7-fold its own receptors by increasing the number of binding sites per mg protein: saline - 392 +/- 75 fmol/mg protein and prolactin 2736 +/- 602 fmol/mg protein (p less than 0.01). This increase did not affect the affinity constant (Ka): saline - 5.28 +/- 0.75 x 10(8) l/mol and prolactin 3.28 +/- 0.40 x 10(8) l/mol (N.S.), in keeping with the stimulatory effect of prolactin in the rat liver and mammary glands. This study further demonstrates the physiological role of endogenous prolactin in maintaining its own binding-sites in the pigeon crop-sac, since the administration of 0.8 ml anti-serum to prolactin resulted in a 63% reduction in the specific binding of labelled hormone in vitro. These results confirm the prolactin binding to the pigeon crop-sac mucosa, quantify the stimulation of this binding by prolactin itself, and demonstrate the role of the endogenous hormone in the maintenance of these receptors.

Animals↗

PubMedDate not supplied

Radon in a self-selected sample of Israeli homes, schools, and workplaces.

Some 1,100 residences and places of work and 400 schoolrooms in Israel were tested for ambient air radon activity concentration in response to requests by the owners, tenants, or local authorities. A polyethylene vial containing activated charcoal was exposed to room air in each of these structures for 7 days, sealed, and transported to the laboratory. Adsorbed radon was extracted with a toluene-based cocktail which was then subjected to liquid scintillation counting. Mean radon activity concentrations were found to vary from city to city by more than an order of magnitude, indicating strong regional differences. The countrywide geometric mean was found to be 38 Bq/m3; the median, 37. The range for these means was 6-77 Bq/m3; for the medians, 11-100 Bq/m3. The highest reading was 9,100 Bq/m3. Our results are basically in line with those from the United States and much of Europe, but apparently higher than those found in the United Kingdom and Japan. It may be fairly said that mass testing for radon (222Rn) inside buildings in the United States began in the wake of the finding of a radon activity concentration in excess of 100,000 Bq/m3 in the home of the Watras family in Boyertown, PA in December 1984. To date, literally millions of American buildings have been tested, and mandatory testing of schoolrooms has begun in some states. In Israel, by contrast, where such a dramatically high measurement has not (yet) occurred, only 5 structures had been checked for radon by 1989.(ABSTRACT TRUNCATED AT 250 WORDS)

Housing↗

PubMedDate not supplied

Effect of prenatal stress on ontogenesis of immunoregulatory cell maturation in mice.

Syngeneically-pregnant CBA mice were stressed by injecting them with saline, sc twice daily, on days 10-18 of their pregnancy. Pups born to these mothers exhibited disturbances in their immuno-regulatory cell development. Splenocytes harvested from these pups, when one day old, failed to suppress xenogeneic Graft-versus-Host reaction and proliferative response of syngeneic mature cells to concanavalin-A, as control splenocytes did. Also, thymocytes of 4-6-day-old mice, born to stressed mothers, did not exert an inhibitory effect on neonatal suppression, as control thymocytes did. These results demonstrate that neonatal stress is an useful physiological model for studying interactions between some regulatory systems of the organism, in its early stages of development.

Animals↗