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At least 19 recordsLinked to original sources
PubMed1979

N,N-dimethylformamide-induced alteration of cell culture characteristics and loss of tumorigenicity in cultured human colon carcinoma cells.

Human colon carcinoma cell lines established in this laboratory were treated in vitro with N,N-dimethylformamide. This polar solvent caused morphological changes in the cells as well as alterations in their growth properties. Untreated cells had cloning efficiencies of up to 77% in soft agar; treatment with N,N-dimethylformamide resulted in a complete loss of clonogenicity in semisolid medium. Growth in the presence of the polar solvent also effected a marked reduction in the tumorigenicity of the cells. Ten of ten nude mice that received a s.c. inoculum of 1 X 10(6) untreated cells developed tumors histologically similar to colonic adenocarcinomas in 10 to 14 days, whereas nine of ten nude mice inoculated with 1 X 10(6) treated cells have shown no sign of tumor 3 to 6 months postinjection. Removal of the polar solvent from the culture medium was accompanied by the reappearance of tumorigenicity and the original cell culture characteristics. Therefore, it appears that N,N-dimethylformamide can reversibly effect the reversion of cultured human colon carcinoma cells to less malignant cell types.

Animals↗
PubMed1977

Stepwise selection of efficient rhizobial cultures through cultural characteristics.

Nodulation and shoot nitrogen of two varieties of soybean (Glycine max) were studied with twenty strains of Rhizobium japonicum. A number of cultural characteristics of the strains in isolation to the symbiotic system were also studied. A stepwise selection method was employed for detecting efficient cultures through the cultural characteristics which showed association with the steps in the symbiotic system. Nodulation of one variety was found to be associated with the dehydrogenase activity and the growth of microbes in the medium containing soil extract, whereas the nodulation of another variety showed association with the growth in the media containing asparagine and tryptophane. The shoot nitrogen of one nodulated cultivar correlated with the microbial growth in Elkan's medium in the medium containing serine and glucose, whereas the shoot nitrogen of the other nodulating variety correlated with the growth of the cultures in the medium containing aspartic acid. The validity of this approach to the problem for detecting efficient strains through cultural characteristics was discussed.

India↗
PubMed1979

Cultural characteristics of Yersinia enterocolitica and Yersinia pseudotuberculosis on differential media.

A study was made of the cultural characteristics of 43 strains of Yersinia enterocolitica and 49 strains of Yersinia pseudotuberculosis on media commonly used for the isolation and differentiation of enteric bacteria. Best growth of the yersinia occurred on MacConkey agar, followed by growth on SS agar; none of the strains of either species developed colonies on brilliant green agar. The Y. pseudotuberculosis strains developed only one type of colony on MacConkey, SS, EMB, Hektoen, and XLD media whereas Y. enterocolitica exhibited more than one type of colony on all of the media except MacConkey and SS agar. The 'lactose-positive' colonies of Y. enterocolitica were especially distinctive on EMB. These were quite dark, with or without a metallic sheen, and closely resembled the colonies of lactose fermenting Escherichia coli on EMB agar. Strains of both Y. enterocolitica and Y. pseudotuberculosis grew better on the differential media at 35 degrees C than at 22 degrees C but the growth of Y. pseudotuberculosis was considerably slower than that of the other species.

Agar↗
PubMed1979

Bovine granulocyte/macrophage and erythroid colony culture: characteristics of the colonies and the assay systems.

Bovine bone marrow granulocyte/macrophage colonies were cultured in vitro in methyl cellulose and in plasma clots using bovine endotoxin-stimulated serum as a source of colony stimulating activity. The endotoxin-stimulated serum was four times as potent as the control serum in the methyl cellulose cultures. No significant increase in the number of colony forming units was observed when bovine marrow cells were maintained in suspension cultures for various periods prior to plating in methyl cellulose. The percentage of glass/plastic adherent cells in bovine marrow cells was observed to be 43% +/- 12 (SD). Benzidine positive erythroid colonies appeared in plasma clot cultures on day 4 and disappeared by day 9. No second population of erythroid colonies appeared either as a function of time or as a function of erythropoietin concentration. The optimum erythropoietin concentration for bovine erythroid cultures was found to be 1.0 unit/mL. A significant difference was observed between animals in their marrow capacity to produce erythroid colonies in culture but no significant difference was observed within individual animals over a period of three months.

Animals↗
PubMed1977

Cultural characteristics of mesoblastic nephromas.

Seven infants and children with renal tumors underwent nephrectomy and the tumors were cultured to investigate the behavior of their cells. In four children over 1 year of age with histologically typical nephroblastoma in the tumor cells were bizarre and disorderly. In one patient 3 months of age where the histology suggested malignancy the tumor culture showed an orderly growth pattern of spindle cells akin to normal kidney and the patient has had no recurrence for 18 months. In one infant seven months of age the histology was consistent with malignancy and this was confirmed on culture showing bizarre cells similar to those of nephroblastoma. The third infant under 1 year of age had a teratoma on histology and an unusual growth pattern on culture characterised by polyhedral cells with long processes and much overlapping. It is suggested that in infants with kidney tumors, tissue culture be used to help in assessing the malignant potential of the tumor and deciding on adjuvant therapy.

Child↗
PubMed1979

Actinobacillus seminis infection in sheep in the Republic of South Africa. III. Growth and cultural characteristics of A. seminis.

Bacteriological tests were done on a large number of different strains of Actinobacillus seminis and also, repeatedly, on the same culture or on different cultures taken periodically from the same donor animal. These tests were also applied to strains of A. seminis representing different serological types, which in turn were compared with strains of Brucella ovis. The tests as applied proved that A. seminis strains have defined, morphological, staining, cultural and biochemical properties, although they can generally be regarded as biochemically inactive. Growth was greatly enhanced on media enriched with blood or serum and also more luxuriant when incubated in a carboxophilic atmosphere. Nitrate reduction was found to be a variable characteristic, as it was more often negative, while weakly positive and negative reactions for hydrogen sulphide production were encountered with equal frequency. On the basis of their bacteriological properties, the strains representing the different serological types can be divided into 2 groups. Strains belonging to the first of these groups conform to the earlier description of A. seminis by Baynes & Simmons (1960) and are usually catalase positive and oxidase negative, while those in the second group more closely resemble Histophilus ovis described by Roberts (1956), and produce variable reactions on the catalase and oxidase tests. Although growth did occur aerobically and was more luxuriant in a carboxyophilic atmosphere in all strains, it was always much slower for strains resembling H. ovis. Similarly, the growth produced by these strains was poorer and more irregular on ordinary nutrient media and, although greatly enhanced and more regular in all strains on enriched media, it was again much slower for these strains. In all stages of development, the colonies of strains similar to H. ovis were always slower and more transparent in appearance, and tended to remain low convex and undifferentiated. Packed organisms of these strains were light yellow (lemon) in colour in contrast to strains resembling A. seminis, which had a greyish-white appearance. A. seminis and B. ovis can clearly be distinguished on their morphology, Stamp staining reaction on both semen and culture smears, colonial morphology, the delayed colony development of B. ovis and sensitivity to dyes and antibiotics.

Actinobacillus↗
PubMed1976

Culture characteristics of cells derived from type II pneumocyte enriched fractions from rabbit and rat.

Type II cell enriched fractions were isolated from rabbit and rat lungs using density gradient centrifugation. Cultures established from these fractions contained predominantly cells similar in most morphological respects to type II pneumocytes. These were in continuous replicating culture for 1 year and still exhibited contact inhibition. Membrane-bound structures reminiscent of, but no longer strictly identical to, type II cell lamellar cytosomes were seen in cells from these long-term cultures although their numbers were reduced in comparison to lamellar bodies in freshly isolated cells. Mitochondrial numbers and sizes, determined morphometrically, were reduced after culture in comparison to freshly isolated type II cells and those in situ. Phosphatidylcholine was synthesized by these cells and released into the extracellular medium. Application of laser activated electronic sizing data, confirmed by direct micrometry, demonstrated a significant increase in cell size as a function of culture. This sizing data, after prior confirmation by electron microscopy, was used as an aid in identifying type II cells and macrophages in dispersion, especially with those cells derived from rabbit lungs.

Animals↗
PubMedDate not supplied

[Biochemical, enzymatic and cultural characteristics and criteria of pathogenicity of staphylocci (study of strains isolated in a hospital environment)].

The Authors have examined the coagulase activity, mannitol fermentation, DNase and phosphatase activity, and production of haemolisins and pigment on 200 strains of Staphylococcus isolated from hospitalized patients affected by various diseases. On the basis of results obtained, they conclude that the evaluation of the pathogenic power of Stah. aureus should be always founded upon a "pattern" of biochemical, enzymatic, cultural and toxinogenetic tests.

Coagulase↗
PubMed1977

Fish cell culture characteristics of a cell line from the silver perch Bairdiella chrysura.

A cell designated SP-1 was established from tissue of the silver perch, Bairdiella chrysura. Cells were fibroblast-like and grew best at 26 degrees C in Leibovitz medium (L-15) containing 15% fetal bovine serum and 0.150 M sodium chloride. Passage 1 to passage 9 SP-1 cells contained a chromosome number of 48; at passages 27 and 50 the modal numbers were 51 and 54, respectively. Confirmation of the origin of SP-1 cells was made by the cytotoxic antibody dye-exclusion test. This cell line supported the growth of lymphocystis virus from the silver perch but was not found to replicate various other fish and mammalian viruses.

Air Sacs↗
PubMed1979

Culture characteristics of human granulocyte-macrophage progenitor cells and their regulation in the context of bone marrow transplantation.

Aspects of the granulocyte-macrophage progenitor cell (CFU-GM) assay not previously used in the content of bone marrow transplantation were discussed in terms of the additional information which could be derived. This focused on the characteristics and responsiveness of the progenitor cells to regulatory activities and other agents. In addition, Ia-like antigenic determinants were demonstrated on human "pre-CFU-GM", an assay which can be used to assess what appears to be a more immature progenitor cell.

Bone Marrow Cells↗
PubMed1978

Cell characteristics of cultured glomeruli from different animal species.

A modified sieving technique has been developed to isolate pure glomeruli from monkey, sheep, dog, rabbit and rat kidney. Glomeruli from all these species have been grown in tissue culture and the glomerular cell outgrowth studied by light microscopy and time-lapse cinemicroscopy. The pattern of growth was the same for all the species studied. In all species, three cell populations have been identified with the features of epithelial cells, mesangial cells and macrophages, although the latter population is only rarely observed. The morphology and culture characteristics of each cell type in all species were similar, including the relative numbers present and rates of division.

Animals↗
PubMedDate not supplied

Paradoxical sleep characteristics and cultural environment. Preliminary results.

The Temiars are a tribe of negroid pygmies of basically Proto-Malaysian affinities. Field-work in the Malaysian jungle provided some observations on the sleep-wakefulness cycle of two young Temiar adults. This cycle was monophasic circumstances permitting. Their rest-activity cycle at night was similar in the jungle and in the laboratory. Polygraphic total night-sleep recordings were made with both of them in the EEG laboratory in the Hospital Besar in Kuala Lumpur. The eye-movement frequencies of PS were compared with those from young adults of the West. Although the differences were not statistically significant, the Rem-densities of the Temiars were constantly at the low side. The significance of the results are being discussed.

Adult↗
PubMed1978

Membrane characteristics of cultured endothelial cells: identification of gap junction.

Membrane characteristics of cultured endothelial cells derived from the superior vena cava of the rabbit were studied in freeze-fracture replicas. Gap junctions were identified, but tight junctions were not seen. In addition to pinocytic vesicles, fenestrations of plasma membrane which are not normally seen in the endothelium of vena cava in situ were found. This finding may be explained by the absence of platelets in the culture medium and is consistent with the current concept of endothelial-platelet interaction.

Animals↗
PubMed1977

Adult rat hepatocytes in primary monolayer culture. Ultrastructural characteristics of intercellular contacts and cell membrane differentiations.

Primary monolayer cultures were obtained in 60-mm petri dishes by incubating 3 X 10(6) isolated hepatocytes at 37 degrees C in Dulbecco's medium supplemented with 17% fetal calf serum. The ultrastructure of monolayer cells was examined after various incubation periods. Within 4 h of plating, the isolated spherical cells adhere to the plastic surface, establish their first contacts by numerous intertwined microvilli, and form new hemidesmosomes. After 12 h of culture, wide branched trabeculae of flattened polyhedral cells extend in all directions. Finally, after 24 h of culture, bile canaliculi are reconstituted, and a biliary polarity is recovered: the Golgi elements, which are scattered throughout the cytoplasm in the isolated cells, are reassembled in front of the newly formed bile canalculi, symmetrically in the adjacent cells; lysosomes are concentrated in that region, and microtubules reappear. Concomitantly, plasma membrane differentiations, namely desmosomes and tight junctions, develop. Tight junctions sealing the bile ducts constitute a barrier to the passage of ruthenium red and horseradish peroxidase. De novo formation of these junctions was studied by the freeze-etching technique: 10-nm particles compose a network of anastomosed linear arrays in the vicinity of the bile canaliculi; in the next step of differentiation, the particles fuse, form short ridge segments and finally continuous branched smooth strands, characteristic of the mature tight junction.

Cell Adhesion↗
PubMed1977

Bovine peripheral blood monocyte cultures: growth characteristics and cellular receptors for immunoglobulin G and complement.

Bovine peripheral blood monocytes were cultured in vitro for as long as 60 days. Although mitotic figures were not observed, the amount of cytoplasm was observed to increase; most cultures developed multinucleated cells, some containing as many as 200 nuclei. In multinucleated cells, the nuclei were peripherally distributed around a cytoplasmic matrix and surrounded by an undulating membrane. Receptors on macrophages were identified with erythrocytes sensitized with various immunoglobulins and complement (C'). A receptor for immunoglobulin G, but not immunoglobulin M, was detected. By the use of freshly prepared equine serum, a C' receptor was detected; however, by the use of freshly prepared bovine serum, C' receptor was not detected.

Animals↗