Stimulatory effect of Propionibacterium granulosum KP-45, glucan and pyran copolymer on the activity of natural killer (NK) cells in murine lungs.

Propionibacterium granulosum KP-45, glucan and pyran copolymer stimulated the elimination of 75Selenomethionine-labelled 3LL tumor cells from murine lungs, as measured 4 hr after intravenous injection of these cells into 16- to 25-week-old B6DF1 mice. This effect was most pronounced 4 to 6 days following intravenous administration of the above biological response modifiers and disappeared 6 to 8 days later. Intraperitoneal injection of all three agents produced only insignificant stimulation results. Spontaneous clearance of 3LL cells from lungs of 8-week-old B6DF1 mice was significantly more effective than in animals over 16 weeks old. Cyclophosphamide suppressed the elimination of tumor cells from lungs in both young and older mice and neutralized the stimulatory effect of P. granulosum KP-45 and glucan. The results suggest that the effector cells responsible for the clearance of radiolabelled 3LL cells from lungs of B6DF1 mice are at least similar to natural killer (NK) lymphocytes.

The kinetics of immunologic and hematologic recovery in mice after lethal total body irradiation and reconstitution with syngeneic bone marrow cells treated or untreated with mafosfamide (ASTA Z 7654).

The immunohematopoietic reconstitution of mice lethally irradiated (TBI) and reconstituted with syngeneic bone marrow cells untreated or treated with mafosfamide (ASTA Z 7654) [TBI + SBMT or TBI + SBMT-Maf mice, respectively] was examined. The number of CFU-S was greatly reduced in TBI + SBMT-Maf mice compared with those in TBI + SBMT mice. The recovery of blood parameters (hematocrit, reticulocytes, erythrocytes, white blood cells, granulocytes, platelets) and of bone marrow and spleen cells, but not of peritoneal exudate cells, was slightly delayed in TBI + SBMT-Maf mice compared with those in TBI + SBMT mice. The time for immune system regeneration was, however, considerably longer in TBI + SBMT-Maf than in TBI + SBMT mice, as measured by the incidence of Ig+, Thy-1.2+, L3T4+, Lyt-2+, and IL-2R+ cells in the spleens. The appearance of Mac-1+ and asialo-GM 1+ cells was only slightly prolonged or unchanged, respectively.

[Method of experimental inhalation-induced respiratory tract contamination]. / Metoda doswiadczalnego wywolywania skazen inhalacyjnych.

The problems of inhalation of radioactive or toxic materials in the respiratory tract are difficult to assess. Good stimulation of physiological conditions is provided by apparatus PIANO-4. The authors describe the function and the possibility of measuring the parameters characterizing aerosol in the respiratory tract. The possibilities of modifying PIANO-4-set are discussed.

Injury and regeneration in rat small intestine cells after exposure to neutrons.

The degree of damage to intestinal crypt epithelium and the process of its regeneration was studied after exposure to neutrons in rats. The aim of the study was an evaluation of the degree of impairment of proliferation of the stem cells in the intestinal crypts following exposure to one dose of 4 Gy, to two doses of 2 Gy each with an interval of 24 hours between them, and to one dose of 4 Gy administered together with a stimulator of leucopoiesis--Leukogen. The animals were administered 3H-thymidine and the per cent of its incorporation was determined. It was found that administration of the divided dose or of one total dose but together with the regeneration-stimulating agent prevented profound epithelial changes. The rate of return to normal incorporation was similar in the rats given the divided dose and in those receiving Leukogen.

Regeneration in small intestine following exposure to X-radiation and neutron beam as estimated in the light of changes in alkaline phosphatase activity and degree of 3H-thymidine incorporation into cells in intestinal crypts.

Swiss mice were irradiated with X-rays (5, 7 and 9 Gy) and neutrons (3 and 5 Gy) determining the degree of 3H-thymidine incorporation into the cells in the intestinal crypts, alkaline phosphatase activity in intestinal homogenate and serum, and radiation-induced leucopenia. It was shown that damage to the cells in intestinal crypts depends on the dose and type of radiation. More radiation-resistant cells covering the intestinal villi showed a significant inhibition of alkaline phosphatase activity at high radiation doses. Changes in intestinal alkaline phosphatase activity were reflected also by changes in its level in the serum where its dependence on the dose of radiation was evident also.

Leucogen effect on postradiation injury of intestinal crypts.

Leucogen effect on the regeneration of cells in intestinal crypts was examined after a sublethal dose of 600R of gamma radiation. The animals were given 3H-thymidine and the per cent of its incorporation was determined. A stimulating effect of Leucogen was observed on the regeneration of cells in the intestinal crypts.

The effect of X-radiation on the process of lung clearance after inhalation of bacteria labelled with 3H-thymidine.

The respiratory tract is cleared very effectively from the inhaled particles by the ciliated bronchial epithelium, secretion of secretory cells, and specialized phagocytic cells. Within 4 hours about 80% of the inhaled microorganisms are destroyed in the respiratory tract. The rate of removal of the micro-organisms from the lungs and their destruction may play a very important role in preventing infection development. The aim of the present experiment was to study the adverse effect of ionizing radiation on the mechanisms involved in cleaning the lungs. Wistar rats were used for this purpose. They received a dose of 500 cGy. The irradiated animals and the control non-irradiated ones inhaled in a PIANO IV apparatus Staphylococcus epidermidis labelled with tritiated thymidine. Determining the clearance of the bacteria from the bronchial tree and pulmonary tissue an impairment of the mechanisms clearing the lungs in the irradiated group was demonstrated. The effect of radiation may be related to a damage to the alveolar macrophages which are principally responsible for destroying bacteria at the level of pulmonary alveoli. The relatively radiation-resistant ciliated epithelial bronchial cells may have their efficiency reduced owing to disturbances in mucus secretion by the secretory cells.

Cytochemical characterization of mouse L1210 leukemia.

Mouse lymphatic leukemia L1210 cells were characterized with polyclonal and monoclonal antibodies and lectins. The cells were found to have the phenotype IgG-, Thy-1.2-, Lyt-1-, Lyt-2-, asialo-GM1-, TL-, I-Ad-, IL-2R+, peanut agglutinin+, and Helix pomatia lectin +/-. They retained expression of H-2Kd and H-2Dd. Thus, these cells resemble "null" cells.