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.     

Radioprotective effect of a protein free parathyroid extract on the mitotic index of rat bone marrow cells.

The protective efficacy of an orally administered bovine protein-free parathyroid extract (PF-PTE) was studied on rat bone marrow cells in vivo with the mitotic index after 850 R irradiation. A remarkable decrease was found in the mitotic activity of bone marrow cells after irradiation in the non-protected animals. However, in the animals treated with PF-PTE after irradiation, a significantly smaller decrease and a faster recovery were found in the mitotic activity of the bone marrow cells.     

Radioprotective effect of a protein free parathyroid extract on the mitotic index of rat bone marrow cells

Summary The protective efficacy of an orally administered bovine protein-free parathyroid extract (PF-PTE) was studied on rat bone marrow cells in vivo with the mitotic index after 850 R irradiation. A remarkable decrease was found in the mitotic activity of bone marrow cells after irradiation in the non-protected animals. However, in the animals treated with PF-PTE after irradiation, a significantly smaller decrease and a faster recovery were found in the mitotic activity of the bone marrow cells.     

The diet and gut microflora influence the distribution of enteroendocrine cells in the rat intestine

Several functions of the gut are locally influenced by peptides and biogenic amines released from enteroendocrine cells. The aim of the present study was to assess whether the luminal stimulus of diet or microbial flora or diet-microbial interactions have an influence on the distribution of enteroendocrine cells along the crypt-surface axes of the small and large intestine. The effects of diet and indigenous flora were investigated by comparing the numbers of argyrophil and serotonin immunoreactive cells in the jejunum and colon of germ free and conventional rats fed either a purified diet containing fine ingredients or a commercial diet containing crude fibre of cereal origin. The effects of human flora were analysed in germ-free rats inoculated with human faecal organisms. 1. Feeding the commercial diet reduced the number of argyrophil endocrine cells in the jejunum and serotonin immunoreactive cells in the colon of gern-free animals but increased the serotonin immunoreactive cells in the colon of conventional animals. 2. The rat flora increased the serotonin immunoreactive cells in the colon of animals fed a commercial diet and decreased in those fed a purified diet. 3. Inculation of human flora increased the numbers of serotonin immunoreactive cells both in the jejunum and colon. The results provide evidence that the dietary changes and diet-microbial interactions can affect the regional number of enteroendocrine cells.     

The peroxisomes of Triturus cristatus (amphibian, urodele) adrenal cortex cells: peroxisome number as a function of steroidogenic activity]

Peroxisomes are scarce in the poorly active interrenal cells of hypophysectomized animals; their number increases drastically in cells which are stimulated by corticotrophic factors. A precise correlation appears thus to exist between the steroidogenic activity of the interrenal cells and the number of peroxisomes in these cells.     

Structural characteristics and distribution of satellite cells along crayfish muscle fibers.

The distribution of satellite cells (sc) in long-sarcomere muscle fibers from the carpopod extensor muscle of the crayfish (Astacus fluviatilis) has been studied electron-microscopically. The sc are spindle-shaped and are oriented parallel to the long axis of a fiber. The mean lengths of sc nuclei (17.00 microns) and that of myonuclei (18.35 microns) differ non-significantly. In older animals, the mean ratio of the number of sc nuclei to the total number of nuclei (sc nuclei + myonuclei) is 0.0716, 0.0848, and 0.034 for the tendon, central and shell segments, respectively. The corresponding values for younger animals are 0.158, 0.166, and 0.081. The mean numbers of sc nuclei per mm of a fiber are 94, 117, and 47 (older animals), and 164, 117, and 94 (younger animals) for the tendon, central and shell segments, respectively. The high incidence of sc per unit fiber length in crayfish may be related to the fact that crayfish muscle fibers have a much larger diameter than vertebrate muscle cells.     

Chronic overcrowding decreases cytoplasmic free calcium levels in T lymphocytes of aged CBA/CA mice

Intracellular calcium concentration is a sensitive marker of the homeostasis of living cells, and its increase is an essential step of T lymphocyte activation. Changes in the environment provoke an adaptive stress-response of the organism. In our present work we have investigated the effect of chronic overcrowding on resting and lectin-stimulated cytoplasmic free calcium concentration of splenic T lymphocytes from young and aged CBA/CA mice (50 animals total). The animals were kept under ‘normal’ (68 cm²/animal) or ‘overcrowded’ (22 cm²/animal) conditions for 3 months. Young animals showed no change in resting and stimulated calcium after overcrowding. T cells from aged mice, however, displayed significantly smaller levels of both resting and lectin-stimulated intracellular calcium concentration (p<0.01 each), as compared to those of the non-stressed, aged animals. This inadequate adaptation in the calcium metabolism of T lymphocytes may significantly contribute to the diminished immune response of the aged in stress.     

Recently discovered functions of glucosylceramides in plants and fungi

Glycosphingolipids are ubiquitous membrane lipids of eukaryotic organisms and a few bacteria. Whereas inositol-containing glycosphingolipids are restricted to plants and fungi, galactosylceramide occurs only in fungi and animals. In contrast, glucosylceramide is the unique glycosphingolipid which plants, fungi and animals have in common. However, there are specific differences in the structure of the ceramide backbone of glucosylceramides from these organisms. A comparison of the structural features and the biosynthesis of glucosylceramides from plants, fungi and animals will contribute to our understanding of their functions, which so far have been analysed mainly in animals. The availability of nearly all genes involved in the biosynthesis of glucosylceramides enables the specific manipulation of glycosphingolipid metabolism by techniques of forward and reverse genetics. Application of this approach to unicellular organisms like yeasts, multicellular filamentous fungi, as well as to complex organisms like plants will reveal common and different glucosylceramide functions in these organisms. These glycolipids play a role both in intracellular processes and in cell-to-cell interactions. These interactions may occur between cells of a multicellular organism or between cells of different species, as in host-pathogen interactions.     

Failure of SV40-transformed lizard cells to induce tumors in autogeneic or allogeneic hosts

Summary Lizard cells from the tails of geckos were readily morphologically and antigenically transformed in vitro by SV40 virus. Neither autografts of these cells nor allografts of SV40 transformed gecko embryo cells produced tumors in animals under observation from 1 to 3 years.     

Failure to SV40-transformed lizard cells to induce tumors in autogeneic or allogeneic hosts.

Lizard cells from the tails of geckos were readily morphologically and antigenically transformed in vitro by SV40 virus. Neither autografts of these cells nor allografts of SV40 transformed gecko embryo cells produced tumors in animals under observation for 1 to 3 years.     

Lymphocyte reactivity in Imuran-treated guinea-pigs and in vitro effect of colchicine

Summary Imuran treatment significantly diminished macrophage migration inhibition in immunized guinea-pigs and the percentage of E-rosette forming cells in all treated animals. 10^–6 M colchicine in vitro significantly increased the percentage of E-rosette forming cells in Imuran-treated animals. The results suggest possible alteration of the lymphocyte receptors after treatment with Imuran.This work was supported by the grants of the Republic Research Fund of Serbia.     

Peritoneal exudate, with mononucleated cells, during normal pregnancy in different species]

A peritoneal cell rich fluid, containing mononucleated leukocytes, macrophages, monocytes, mast cells and lymphocytes, was observed during normal pregnancy in animals belonging to various species. These cells might be concerned in a homograft-like, mother-foetus, relationship.     

Toxic effect of cadmium nitrate on the liver of Channa punctatus.

Exposure of a fresh water fish, Channa punctatus, in a medium containing as low as 0.01 ppm of cadmium nitrate, resulted in the necrosis of hepatic cells. A temporary recovery of these cells was however observed when the animals were exposed to lower concentrations.     

Effect of bromocriptine on the "prolactin-like cell" of Nectophrynoides occidentalis (Amphibia, viviparous Anura): optical and electronic microscopical studies]

Bromocriptin has an effect on prolactin-like cells of Nectophryno?des occidentalis. 16 days after delivery, these cells are fully active in normal animals. Retention of secretory granules and myelinic formations have been observed in the prolactin-like cells of females treated by CB 154.     

A gelatin sponge model for studying tumor growth: quantitation of tumor cells and leukocytes in the CHO tumor

A gelatin sponge model system for tumor cell inoculation and retrieval of tumor-associated leukocytes is described. Gelatin sponges pre-implanted in nude mice harboring tumorigenic Chinese hamster ovary cells (line CHO) were examined at 2 and 11 days after injection of tumor cells for tumor cell content and leukocyte accumulation after digesting the sponge matrix in collagenase solution. The data indicate a progressive influx of host cells consisting primarily of macrophages, neutrophils and lymphocytes. The total number of viable tumor cells as well as the fraction of surviving tumor cells with clonogenic potential also increased with tumor age. Blank sponges not harboring tumor cells elicited an inflammatory response in the animals which did not change appreciably with length of sponge residence. However, when the sponges were harboring tumor cells, the accumulation of host leukocytes far exceeded that which occurred in blank sponges. This observation suggests a host response directed toward the tumor which is absent in animals bearing blank sponges. Apart from providing anchorage for injected cells, the gelatin sponge, by virtue of its digestibility in collagenase, makes possible the easy retrieval and precise quantitation of tumor-associated host cells.     

Chromosome aberrations in cattle raised on bracken fern pasture

Thirteen cows maintained on natural bracken fern (Pteridium aquilinum) were analyzed cytogenetically. The frequency of structural chromosome aberrations detected in peripheral blood cells was significantly higher when compared to that detected in animals raised on pasture containing no bracken fern. We discuss the clastogenic action of fern and its synergistic action with infection by type 2 and 4 papilloma virus in the same animals.     

Cyclic AMP level in red blood cells of Plasmodium berghei-infected Mastomys natalensis.

The present report describes the changes in cyclic AMP level which occur upon parasitization of red cells by Plasmodium berghei. Parasitized erythrocytes were separated from the non-parasitized population by percoll density-gradient centrifugation. An increase in the cyclic AMP content of both non-parasitized and parasitized erythrocytes of infected animals compared with that of uninfected animals was observed. The patterns of physiological response to isoproterenol in normal, parasitized and non-parasitized erythrocytes were identical.     

Lymph node metastases of EMT6 tumour in nude mice

Metastatic axillary lymph nodes following the injection of EMT6 tumour cells were observed in athymic nude mice, more often in female animals, and had a rapid growth rate. These metastases did not develop in syngeneic hosts. The latency of their appearance was inversely related to the number of injected cells.     

High levels of free fatty acids and their esters in lymphoid cells resistant to cortisone or cyclophosphamide

Summary The lymphoid cells from thymus, slpeen or mesenteric lymph node of mice treated with hydrocortisone or cyclophosphamide contained the significantly high levels of free fatty acids, triglycerides and cholesterol esters as compared to the corresponding cells from untreated animals.     

Epithelial localization of pyruvate kinase L (ATP pyruvate phosphotransferase EC 2.7.1.40) in rat liver]

Using three methods: histoenzymatic and immunoenzymatic, stained with tetrazolium salt, and immunofluorescence, we have localized PK "L" in hepatocytes. This localization in the cytoplasm of the cells differs widely in intensity with diet or hormone administration. Maximal with animals fed on high carbohydrate diet, still elevated with a subsequent insulin administration, it decreases with a normal diet to become weaker in animals, which have fasted for 48 hrs.