J Biol Regul Homeost Agents, 1989 Jul-Sep, 3(3), 112 - 7 Differential induction of 2',5'-oligoadenylate synthetase by IFN-beta ser and IFN-alpha 2 in serum-supplemented and serum-free HL-60 leukemic cell cultures; Fraioli M et al.; The influence of cell culture conditions on the induction of 2',5'-oligoadenylate (2-5A) synthetase by recombinant interferons IFN-beta ser and IFN-alpha 2 has been investigated in human HL-60 leukemic cells . Cells maintained either in the fetal bovine serum-supplemented medium (FBS-SM) or in a serum-free, chemically defined Nutridoma-supplemented medium (SFN-SM) are treated with different concentrations of the two types of IFN and the extent of 2-5A synthetase induction compared . While cells in FBS-SM show a substantially greater increase in 2-5A synthetase by IFN-beta ser than cells in SFN-SM, the latter culture condition is significantly more effective in elevating synthetase activity with the addition of IFN-alpha 2 . These data suggest that there are growth modulators and other "factors" in the fetal bovine serum which may interact specifically with each type of IFN to coordinate the optimal expression of the 2-5A synthetase protein. J Pharm Belg, 1989 Jul-Aug, 44(4), 261 - 9 {The effect of cross-linked protein microcapsules on cell cultures}; Desoize B et al.; Microcapsules (diameter range: 5 to 100 microns) prepared through interfacial cross-linking of proteins with terephthaloylchloride exhibited a cytotoxic effect on L 1210 cell cultures . IC50 was: 0.86 mg/ml +/- 0.24 for microcapsules prepared from human serum albumin (AT microcapsules) and 0.63 mg/ml +/- 0.05 for those obtained from egg white lysozyme (LT microcapsules) . With K 562 cells IC50 were 0.42 +/- 0.11 mg/ml (AT microcapsules), 0.06 mg/ml (LT microcapsules) . An increase in the cytotoxicity was observed when reducing the size of the microcapsules and when increasing the reaction pH or the terephthaloylchloride concentration, or the relative concentration of microcapsules vs cells . On the contrary, the cytotoxic effect decreased, when prolonging the cross-linking time . The activity was not affected when the microcapsules were washed with toluene or with an alkaline solute . The cytotoxic effect, which appears for relatively high doses, apparently involves a contact between the microcapsules and the cells and seems to be related with the degree of cross-linking of the constitutive protein. ASAIO Trans, 1989 Jul-Sep, 35(3), 677 - 9 Development of a novel artificial matrix with cell adhesion peptides for cell culture and artificial and hybrid organs; Matsuda T et al.; The authors present a novel artificial matrix with high cell adhesion and growth rate that was produced by chemical fixation of an RGD-containing peptide (Arg-Gly-Asp) on a polyvinyl alcohol (PVA) surface . The logical sequence behind the molecular design of an artificial matrix that mimics natural adhesive proteins, such as fibronectin, is based on the fact that an RGD tripeptidyl amino sequence is the minimal common adhesion site of adhesive proteins . Activation of surface hydroxyl groups by carbonyl diimidazole successfully incorporated GRGDSP (Gly-Arg-Gly-Asp-Ser-Pro) onto PVA films . The resultant film surface was found to be bioactive, molecularly recognizing the adhesive receptor of bovine endothelial cells . Thus, the artificial matrix mimics active adhesion sites and serves as a novel artificial matrix that may be useful for cell culture, tissue-compatible implants, and hybrid artificial organs. Vopr Virusol, 1989 Jul-Aug, 34(4), 466 - 74 {Effectiveness of Soviet derivatives of phosphonic acid and their combination with interferon inducers in cell cultures and in a model of herpetic meningoencephalitis in mice}; Samoilovich EO et al.; Nationally synthesized chemopreparations: phosphonoacetic (PAA), phosphonoformic (PFA) acids and acycloguanosine (Acg) exhibit a marked antiherpetic effect in cell cultures and marked protective effect in herpes meningoencephalitis in mice induced by intraperitoneal inoculation of herpes simplex virus type 1 (HSV-1) (43% PFA, 33% PAA, 25% Acg) . Both in vitro and in vivo (mouse meningoencephalitis), PFA (its trisodium salt) on the whole proved to be less toxic than PAA but exerted a higher or similar antiherpetic effect . The combined use of pyrophosphate analogues (PAA, PFA) with Acg is more effective that their use separately both in vitro and in herpes meningoencephalitis in mice an produces an additive effect or one similar to it . Systemic inoculation of interferon inducers, lafarine or ridostine, is effective in herpes meningoencephalitis in mice induced by intraperitoneal inoculation of HSV-1 (the protective effect 33% and 26%, respectively) . The combined use of ridostine and PAA in herpes meningoencephalitis in mice led to synergistic effect. Biull Eksp Biol Med, 1989 Jul, 108(7), 93 - 5 {Retinoic acid modification of cell culture used for reproduction of enteropathogenic viruses}; Tatskaia VN et al.; The 0.001-0.005% retinoic acid injection into the growth cultural medium of prime and continue cell cultures 12-24h before inoculation considerably raised the cell sensitivity to animal entero- and coronaviruses . The entero- and coronaviruses concentrations in cultural medium increased by 10(1.58) and 10(1.68)TCID 50/1.0 respectively . The optimized parameters of the cell culture processing for the enteropathogenic viruses reproduction improvement are proposed. Mol Cell Endocrinol, 1989 Jul, 64(2), 161 - 7 Catechol estrogen formation in MCF-7 cell culture and effects of bromoestrogen inhibitors; Brueggemeier RW et al.; Agonist and antagonist activities have been reported for several catechol estrogens given exogenously . Since the metabolic clearance rate for catechol estrogens in the body is very rapid, catechol estrogens produced at other tissues will have minimal effect on breast tissue . Information of the extent of catechol estrogen formation within cells is critical in assessing the overall importance of these estrogen metabolites . Investigations of the conversion of estrogens to catechol estrogens were performed in the MCF-7 human mammary carcinoma cell culture system . Reverse-phase high-performance liquid chromatography (HPLC) analysis demonstrated that very little metabolism of estradiol occurs after 48 h, with only small amounts of estrone, 2-hydroxyestradiol, 2-hydroxyestrone, and estriol being observed . The total amount of 2-hydroxyestrogen products formed from 1 microM estradiol was 406.2 pmol (SD = 60.9) per 3 x 10(7) cells in 48 h . Similar results were obtained using the simpler radiometric assay for estrogen 2-hydroxylase, which measures the release of 3H2O from {2(-3)H}estradiol . The effects of inhibitors of estrogen 2-hydroxylase were also examined in MCF-7 cells . 2-Bromoestradiol, 4-bromoestradiol, and 2,4-dibromoestradiol effectively block estrogen 2-hydroxylase in a dose-dependent manner in MCF-7 cultures, with ED50 of approximately 1 microM for each inhibitor . Furthermore, these bromoestrogens bind poorly to estrogen receptors in MCF-7 cells and do not alter cell growth . Thus, in MCF-7 mammary cell cultures, metabolism of estradiol occurs to only a minor degree, and it is unlikely that the levels of catechol estrogens would reach physiologically relevant concentrations in the intact breast cancer cells.(ABSTRACT TRUNCATED AT 250 WORDS) Avian Dis, 1989 Jul-Sep, 33(3), 578 - 81 Propagation of avian rotavirus in primary chick kidney cell and MA104 cell cultures; Myers TJ et al.; The Ch2 strain of avian rotavirus was propagated in primary chick kidney cell (CKC) and MA104 cell cultures in the presence of trypsin . Cultures were evaluated for the presence of rotavirus by an indirect fluorescent antibody (IFA) assay and by an indirect enzyme-linked immunosorbent assay (ELISA) . After two passages, the viral titer was significantly higher in CKC than MA104 cell cultures . Also, the IFA assay was more sensitive than the indirect ELISA for detecting rotavirus-positive cultures. Virus Res, 1989 Jul, 13(3), 207 - 12 Altered hepatitis A VP1 protein resulting from cell culture propagation of virus; Robertson BH et al.; The published sequence of hepatitis A virus (HAV), strain HAS-15, after 20-30 cell culture passages contains an 18 nucleotide deletion (Ovchinnikov et al., 1985) within the VP1 genome region . This results in a significant amino acid difference of the VP1 protein when this strain of HAV is compared with other published HAV sequences . Comparison of the polyacrylamide gel electrophoretic migration of HAS-15 HAV and two other strains of HAV revealed that the HAS-15 VP1 molecule migrated faster than the VP1 molecule of the other two strains . Enzymatic amplification of viral RNA derived from the original stool suspension and cell culture adapted HAS-15 using the polymerase chain reaction followed by hybridization analyses with selected synthetic oligonucleotide probes revealed that the original wild type virus did not contain the deletion . These results confirm that cell culture adapted HAS-15 contains an eighteen nucleotide deletion which apparently was selected during cell culture adaptation. J Clin Microbiol, 1989 Jul, 27(7), 1659 - 60 Enhanced infectivity of bluetongue virus in cell culture by centrifugation; Sundin DR et al.; The effects of centrifugation of the infection of cell culture with bluetongue virus (BTV) were investigated . Baby hamster kidney cells were infected with BTV with or without centrifugation . Viral antigen was detected by immunofluorescence at 24 h in both centrifuged and noncentrifuged cultures . However, after 24 h of infection, the production of PFU in centrifuged cell cultures was 10- to 20-fold greater than that seen in cultures not centrifuged . In addition, centrifugation enhanced the direct detection of PFU from blood samples collected from a sheep experimentally infected with BTV. J Clin Microbiol, 1989 Jul, 27(7), 1554 - 9 Comparison of in situ hybridization and monoclonal antibodies for early detection of cytomegalovirus in cell culture; McClintock JT et al.; The abilities of each of four diagnostic tests--direct fluorescent monoclonal antibody (direct FA) staining, indirect fluorescent monoclonal antibody (indirect FA) staining, in situ hybridization with biotinylated DNA probes, and in situ hybridization with DNA probes directly linked to enzymatically active horseradish peroxidase-to detect cytomegalovirus soon after culture were compared . Only the indirect FA test and the in situ hybridization method with directly linked HRP-DNA probes provided consistent and reliable cytomegalovirus detection as early as 15 h postinfection. Histol Histopathol, 1989 Jul, 4(3), 367 - 74 Early human trophoblast cell cultures . A morphological and immunocytochemical study; Logothetou-Rella H et al.; Rapidly growing cytotrophoblasts were isolated from early human chorionic villi and the Papanicolaou method was used to characterize their cytology and transformation into syncytiotrophoblasts . Cytotrophoblasts fused and formed binucleated cells or mononucleated intermediate cells . Syncytial cells were formed by fusion of small cytotrophoblasts or intermediate cells and cytotrophoblasts . Glycosaminoglycans were produced in cytotrophoblasts and released extracellularly . Here they were accumulated and/or diffused into a continuous layer covering the cells . Glycosaminoglycans in syncytial cells were contained in well defined membranous sacs . Cytotrophoblasts only grown beyond confluence differentiated into villi with a villus-like histology. J Cell Physiol, 1989 Jul, 140(1), 119 - 30 Down-regulation of proteolytic activity in 12-O-tetradecanoyl-phorbol-13-acetate-induced K562 leukemia cell cultures: depletion of active urokinase by excess type 1 plasminogen activator inhibitor; Alitalo R et al.; The human chronic myeloid leukemia cell line K562 acquires several megakaryoblastoid features when cultured in the presence of the tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA) . We observed strongly increased secretion of several proteins into the culture media of K562 cells within a few hours of TPA treatment . Two of the major secreted polypeptides were identified by immunoprecipitation from media of metabolically labeled cultures as the tissue inhibitor of metalloproteinases (TIMP) and the type 1 plasminogen activator inhibitor (PAI-1) . Maximal amounts of PAI-1 mRNA and secretion of PAI-1 polypeptides were observed after 24 hr of TPA treatment and PAI-1 persisted at elevated levels for several days . The induction of PAI-1 mRNA was dependent on de novo protein synthesis . Uninduced and induced cells secreted urokinase plasminogen activator in its single-chain proenzyme form (pro-u-PA), which was cleaved extracellularly to the active two-chain form as shown by pulse-chase labeling experiments . Upon TPA induction, the secretion of u-PA polypeptides increased severalfold, and there was a transient accumulation of pro-u-PA in the culture medium . However, this did not lead to increased u-PA activity in the cultures, since active u-PA was removed by complex formation with the large excess of coinduced PAI-1 . Induction of u-PA mRNA was biphasic: The first peak of about tenfold increase in steady-state u-PA mRNA at 3 hr was followed by a steep decline to the baseline level at 12 hr, and a second, slower accumulation of u-PA mRNA occurred over the next few days . The biphasic accumulation of u-PA mRNA was also reflected in u-PA protein synthesis . We conclude that concerted changes in favor of a nonproteolytic extracellular environment occur in TPA-induced K562 cultures undergoing megakaryoblastoid differentiation . These changes include excessive secretion of TIMP and inhibition of the induced u-PA by the simultaneous accumulation of PAI-1. J Virol Methods, 1989 Jul, 25(1), 63 - 70 Growth of a murine coronavirus in a microcarrier cell culture system; Talbot PJ et al.; The growth of the murine coronavirus MHV-A59 on murine DBT cells adapted to dextran-made Cytodex 1 microcarriers was studied in comparison with cells grown on plastic dishes . With a microcarrier concentration of 5 g/l in spinner flasks, a density of 3 x 10(6) cells/ml was reached in 7 days . Under these conditions, cells supported virus growth to the same extent as when they were grown on the plastic substratum . This was shown by a similar development of virus-induced syncytia, the release of an equivalent number of infectious progeny virions per cell, similar recoveries observed after concentration and purification and an identical appearance of the purified virus under the electron microscope . On the other hand, the technical convenience of microcarriers and the ease of scale-up emphasize their potential for the growth of coronaviruses. Zentralbl Bakteriol, 1989 Jul, 271(2), 237 - 43 Competition binding assay in cell culture for identification of epitopes on enveloped and naked viruses; Oosterlaken TA et al.; Virus infected monolayers, in wells of 96-well plates, could be used as antigen in competition binding assays to identify epitopes on respectively Semliki Forest virus, encephalomyocarditis virus and mumps virus. Biochem Biophys Res Commun, 1989 Jun 30, 161(3), 1013 - 9 Bromoconduritol treatment delays intracellular transport of secretory glycoproteins in human hepatoma cell cultures; Yeo KT et al.; Previous studies in our laboratory have shown that specific glycan structures are required for the normal secretion of some glycoproteins . Bromoconduritol is known to inhibit the removal of the innermost glucose moiety from the Glc3Man9(GlcNAc)2 precursor of N-linked glycoproteins . We have used this inhibitor to investigate the possible role of glycan structure in the intracellular transport of secretory glycoproteins of Hep G2 cultures . Cells were pretreated with 1mM bromoconduritol for 1h, pulsed with {35S}-methionine for 10min and chased for varying intervals . Specific glycoproteins and albumin were immunoprecipitated from the cell lysate and medium . We found that bromoconduritol-treatment inhibited the secretion of alpha 1-protease inhibitor, ceruloplasmin, alpha 2-macroglobulin, transferrin, and alpha-fetoprotein . Apparently, the glucosylated high-mannose intermediate is not secreted, since glycoproteins in the medium are of complex form . We conclude that the removal of the innermost glucose residue from secretory glycoprotein represents an important regulatory step in the intracellular transport pathway. Biochemistry, 1989 Jun 27, 28(13), 5688 - 93 Changes in chromatin structure during the aging of cell cultures as revealed by differential scanning calorimetry; Almagor M et al.; Nuclei from cultured human cells were examined by differential scanning calorimetry . Their melting profiles revealed four structural transitions at 60, 76, 88, and 105 degrees C (transitions I-IV, respectively) . In immortalized (i.e., tumor) cell cultures and in normal cell cultures of low passage number, melting profiles were dominated by the 105 degrees C transition (transition IV), but in vitro aging of normal and Werner syndrome cells was associated with a marked decrease in transition IV followed by an increase in transition III at the expense of transition IV . At intermediate times in the aging process, much DNA melted at a temperature range (95-102 degrees C) intermediate between transitions III and IV, and this is consistent with the notion that aging of cell cultures is accompanied by an increase in single-strand character of the DNA . Calorimetric changes were observed in the melting profile of nuclei from UV-irradiated tumor cells that resembled the age-induced intermediate melting of chromatin . It is suggested that aging is accompanied by an increase in single-stranded character of the DNA in chromatin, which lowers its melting temperature, followed by strand breaks in the DNA that destroy its supercoiling potential. J Biol Chem, 1989 Jun 25, 264(18), 10384 - 7 Bile acid synthesis in cell culture; Javitt NB et al.; Confluent cultures of Hep G2 cells were found to synthesize chenodeoxycholic and cholic acids continually . Chenodeoxycholic acid was synthesized at the rate of 58 +/- 8.6 micrograms/96 h, a rate more than 7-fold greater than that for cholic acid . Addition of 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha-triol but not the -3 alpha, 7 alpha-diol was followed by an increase in cholic acid synthesis, thus indicating a relatively low 12 alpha-hydroxylase activity . Endogenous synthesis of monohydroxy bile acid ester sulfates was found, with maximum rates of 135 and 74 micrograms/96 h for lithocholic and 3 alpha-hydroxy-5-cholenoic acids, respectively . Incubation of Hep G2 cells in medium containing 25% D2O permitted a comparison of the precursor/product relationship of cholesterol with 3 beta-hydroxy-5-cholenoic acid . The pattern of incorporation of deuterium was in accordance with that expected, thus allowing the conclusion that this monohydroxy bile acid is derived from cholesterol and should be considered together with chenodeoxycholic and cholic acids as a primary bile acid. Brain Res, 1989 Jun 19, 490(1), 110 - 25 Development and selective neurodegeneration in cell cultures from different hippocampal regions; Mattson MP et al.; Previous studies have shown that pyramidal neurons in hippocampal regions CA1 and CA3 are selectively vulnerable in several neurodegenerative disorders and that a subpopulation of pyramidal neurons in cell cultures of embryonic hippocampus are sensitive to glutamate neurotoxicity . In order to determine whether the patterns of cell loss seen in situ correlate with intrinsic differences in neuronal sensitivities to glutamate-induced degeneration acquired during development, we characterized cultures established from different regions of postnatal rat hippocampus and then examined neuronal sensitivity to glutamate . Tissue corresponding to the dentate gyrus (DG) and regions CA1, CA2 and CA3 of Ammon's horn was removed by microdissection from transverse hippocampal slices and was used to establish cultures of dissociated cells . Cultures from all 4 regions contained 3 major morphological classes of neurons; pyramidal-like, bipolar and stellate . Pyramidal-like neurons comprised the majority of neurons in all cultures; these neurons extended one long and branching axon, and one or more short dendrites . Immunocytochemistry showed that all neurons possessed high levels of glutamate-like and gamma-aminobutyric acid (GABA)-like immunoreactivity when grown in isolation . In contrast, when bipolar and pyramidal neurons were cultured in contact with glial cells, glutamate and GABA immunoreactivity were selectively reduced in the bipolar and pyramidal cells, respectively, suggesting that cell interactions influence neurotransmitter phenotype . Subpopulations of hippocampal neurons from each hippocampal region were vulnerable to glutamate-induced neurotoxicity . Bipolar and stellate cells were resistant to glutamate, while pyramidal-like neurons showed varying degrees of sensitivity to glutamate depending upon which region they were taken from . Experiments with specific glutamate receptor agonists and antagonists demonstrated that both non N-methyl-D-aspartic acid (NMDA) receptors and NMDA receptors mediated glutamate-induced degeneration . There were clear differences in the vulnerability of the pyramidal-like neuron populations in cultures from the different hippocampal regions . The rank order of the vulnerability of pyramidal-like neurons to glutamate-induced neurodegeneration between regions in culture was: DG less than CA2 less than CA3 less than CA1 . This pattern of selective vulnerability in cell culture corresponds directly to the pattern of selective cell loss seen in situ in Alzheimer's disease, epilepsy, and stroke suggesting that intrinsic neuronal differences in glutamate sensitivity may be involved in these disorders. Tsitologiia, 1989 Jun, 31(6), 685 - 9 {The protein-synthesizing apparatus of a BHK-21 (C-13) cell culture and of its large-cell clone C-9}; Iamshchikova GV et al.; Cell line BHK-21 (C-13) and its large cell clone C-9 differ in morphology, karyotype and cultural properties . Clone C-9 is polyploid . It has been shown that C-9 clone cells display 2.5-3-fold excess in the nucleolus organizer region (NOR) in chromosomes, and 2-3 times higher intensity of protein synthesis and of ribosomal material content compared to the original line . Data of sedimentation analysis and of protein synthesis activity of the total ribosomal material in the cell-free translational system from rabbit reticulocytes allow to conclude that the quantity and size of polyribosomes in C-9 cells are higher than in cells of the original line . Apparently, the quantity of NOR-chromosomes reflect the activity of protein translation system of investigated cells. Scanning Microsc, 1989 Jun, 3(2), 681 - 91; discussion 691-3 Morphological effects of lonidamine on two human-tumor cell culture lines; Szekely JG et al.; Lonidamine, 1-(2-4-dichlorobenzyl)-1-H-indazol-3-carboxylic acid, is an anticancer drug that has its primary action on cellular metabolism rather than cell division . Since lonidamine is not effective in all tumor cells, we have tested it in two human-tumor cell culture lines: MOLT-4, a T-leukemia and U-87 MG, a glioma . Lonidamine exposure of MOLT-4 cells at 50 micrograms/mL and pH 6.7 disrupted the mitochondria within 1 h of treatment . The mitochondria were swollen and the cristae were disrupted . When the treated cells were re-incubated in fresh medium at pH 7.4 the mitochondria rapidly returned to their normal morphology . The U-87 MG glioma cells did not show ultrastructural disruption after 1-h treatment with lonidamine at concentrations up to 200 micrograms/mL at pH 6.7 . In the concentration range of 25 micrograms/mL to 200 micrograms/mL, lonidamine did not produce any cell killing in MOLT-4 after a 1-h exposure at pH 7.4, although the drug had some limited effectiveness at pH 6.7 . Compared to sham-treated controls, long exposures to 100 micrograms/mL of lonidamine at pH 6.7 reduced survival in MOLT-4 to 92% and 53% after 6-h and 24-h exposures, respectively . Survival of U-87 MG glioma cells was also strongly pH dependent, a 2-h exposure to 50 micrograms/mL lonidamine at pH 7.4 did not cause cell death; however, survival dropped to 84% of the control at pH 6.65. J Lipid Res, 1989 Jun, 30(6), 899 - 905 Metabolism of 25-hydroxycholesterol in mammalian cell cultures . Side-chain scission to pregnenolone in mouse L929 fibroblasts; Taylor FR et al.; Three mammalian cell lines were examined for their ability to metabolize the regulatory oxysterol, 25-hydroxycholesterol, and derepress 3-hydroxy-3-methylglutaryl CoA reductase . In mouse L cell fibroblasts reductase activity was restored with the concomitant metabolism of 25-hydroxycholesterol via side-chain hydroxylation and scission of the C20-C22 bond . Chinese hamster lung cells did not appear to derepress the reductase and these cells and Chinese hamster ovary cells did not metabolize 25-hydroxycholesterol to a significant extent . Only 5-10% of the oxysterol became esterified with a fatty acid in any of the cell lines when grown in the described culture conditions. Kokubyo Gakkai Zasshi, 1989 Jun, 56(2), 244 - 62 {Application of renal epithelial cell culture in study of organ toxicity of heavy metals}; Morisue H; To elucidate the possible toxicity of heavy metals in a renal tubular epithelial cell line derived from a normal cynomolgus female monkey (JTC-12, P3 (F}, the effects of HgCl2, Na2CrO4 and NiCl2 on the dome formation and the release of intrinsic enzymes from the cells were studied . The results were as follows: 1 . The JTC-12 . P3(F) cells showed an evident dome formation when an inducer of differentiation (hexamethylene bisacetamide or N, N-dimethylformamide) was added to the medium . 2 . Ouabain inhibited the dome formation of the JTC-12 . P3(F) cells, suggesting that the dome formation is dependent on the active transepithelial transport of Na+ . 3 . The addition of 40 microM HgCl2, 10 microM Na2CrO4 or 20 microM NiCl2 inhibited the dome formation . 40 microM HgCl2, 10 microM Na2CrO4 or 150 microM NiCl2 caused significant cell death . 4 . The addition of 5 microM HgCl2, 1 microM Na2CrO4 or 20 microM NiCl2 resulted in an increased release of lactate dehydrogenase into the medium for 6 hours . 20 microM HgCl2, 1 microM Na2CrO4 or 20 microM NiCl2 increased the medium gamma-glutamyl transpeptidase concentration for 6 hours, but 40 microM HgCl2, 5 microM Na2CrO4 or 100 microM NiCl2 did not cause a significant increase in the medium alkaline phosphatase concentration . The results suggest that the JTC-12 . P3(F) cells possess, at least in part, functional characteristics similar to the other kidney proximal tubular cells and that the inhibition of dome formation and enzyme release from the cells may be the early indicators that predict metal toxicity to the cells. Cell Biol Toxicol, 1989 Jun, 5(2), 217 - 26 Use of cell cultures for predicting the biological effects of mycotoxins; Robbana-Barnat S et al.; The risk presented by mycotoxins is a toxicological problem . As the data given by physico-chemical analysis may be difficult to translate in terms of toxicity, however, especially when considering multiple contamination, we have developed a system for toxicological analysis of mycotoxins using cell cultures of different origins . The response of several cell types to a number of well defined mycotoxins was obtained in three days . This approach allowed us to: demonstrate and quantify a toxic effect, define some organ specificity related to the preferential action on a particular cell type, and detect an immunosuppressive effect . The results indicate that the system can be used for toxicological screening and that it has a predictive value for the pathological effects of tested products. Am J Pathol, 1989 Jun, 134(6), 1227 - 32 Purification of murine endothelial cell cultures by flow cytometry using fluorescein-labeled griffonia simplicifolia agglutinin; Sahagun G et al.; Griffonia simplicifolia agglutinin (GSA) is a valuable histochemical tool in the identification of endothelium . In this study GSA labeled with fluorescein isothiocyanate (GSA-FITC) was used to purify cultures of murine cerebral microvascular endothelium . Cultures were stained with GSA-FITC, then sorted using a fluorescence-activated cell sorter (FACS) . GSA-positive endothelial cells were collected, re-cultured, and subsequently re-analyzed by FACS using GSA-FITC . Cultures that initially contained 80 +/- 3 to 89 +/- 3% (X +/- SE) GSA-positive cells were purified to 98 +/- 1% positivity . Immunohistochemistry with an anti-muscle-action antibody confirmed that FACS sorting of GSA-FITC-stained cells effectively removed contaminating smooth muscle cells from endothelial cell cultures . Viability, proliferation, and prostaglandin production of the cells was unaltered by lectin staining and FACS sorting . Thus, GSA-FITC can be used in conjunction with flow cytometry to enhance the purity of murine endothelial cell cultures without adversely affecting cell viability, growth, or metabolism. J Clin Microbiol, 1989 Jun, 27(6), 1399 - 400 Comparison of HeLa 229 and McCoy cell cultures for detection of Chlamydia trachomatis in clinical specimens; Thewessen EA et al.; Consecutive clinical specimens of Chlamydia trachomatis (1,048) were inoculated in parallel on DEAE-dextran- and cycloheximide-treated HeLa 229 cells and cycloheximide-treated McCoy cells . HeLa 229 cell culture detected 113 positive specimens, and McCoy cell culture detected 103 positive specimens . This difference is not significant . However, HeLa 229 cell culture yielded significantly more inclusions than McCoy cell culture in the 95 specimens positive in both cell types (P = 0.042) . For routine diagnostic purposes, a choice for one of the cell types may be determined by local preferences. Ecotoxicol Environ Saf, 1989 Jun, 17(3), 297 - 307 Effect of methylazoxymethanol acetate on bluegill sunfish cell cultures in vitro; Borenfreund E et al.; An epithelioid cell line derived from fin tissue of bluegill sunfish (designated BG/F) exhibited early indications of cell transformation upon exposure to methylazoxymethanol acetate (MAM acetate) . Such changes included the induction of polyploidy, increased colony-forming efficiency, loss of contact inhibition, and formation of transformed foci . Unlike later transformation characteristics observed with mammalian cells, the MAM acetate-treated BG/F cells could not be propagated under conditions of anchorage independence in soft agar . Incubation of BG/F cells with N-methyl-N'-nitro-N-nitrosoguanidine, followed by exposure to 12-O-tetradecanoylphorbol-13-acetate, was not observed to cause cell transformation under the experimental conditions . The controls of a fibroblastic cell culture derived from gill tissue of bluegill sunfish showed spontaneous transformation after 6 months of passage, similar to the transformation observed in the experimental MAM acetate treated gill cultures. Blut, 1989 Jun, 58(6), 295 - 8 Long-term survival of murine erythroid progenitors in long-term bone marrow culture and stromal cell culture: differentiation in peritoneal diffusion chamber culture; Ben-Ishay Z et al.; Bone marrow cells of normal and cytosine-arabinoside (Ara-C) treated C57B1 mice were cultured in primary long-term culture (LTBMC) for a period of eight weeks . Non-adherent cells collected at weekly culture feedings consisted of neutrophils, macrophages and megakaryocytes . These were transferred into a) secondary peritoneal diffusion chamber cultures (DC) and b) secondary stromal cell cultures (SCC) first, and then into tertiary DC cultures . While in LTBMC and SCC there was no evidence of erythropoiesis, many erythroid colonies developed in DC cultures . It appears that undifferentiated erythroid progenitors may have a long survival in LTBMC and SCC devoid of erythropoietin and then differentiate in vivo in DC cultures in host mice without specific erythropoietic stimuli . Terminal differentiation and maturation of erythroid progenitors occurs to a limited extent in conventional DC cultures . The large number of erythroid colonies in DC observed in the present study could be due to increased sensitivity of undifferentiated erythroid progenitors from LTBMC to physiological levels of Epo in host mice of DC. Am J Physiol, 1989 Jun, 256(6 Pt 2), R1184 - 91 Mechanism of ion transport by avian salt gland primary cell cultures; Lowy RJ et al.; Confluent sheets formed from primary culture of avian salt gland secretory cells exhibit a short-circuit current (Isc) in response to cholinergic and beta-adrenergic stimulation {Lowy, R . J., D . C . Dawson, and S . A . Ernst . Am J . Physiol . 249 (Cell Physiol . 18): C41-C47, 1985} . To establish the ionic basis for the Isc, transmural fluxes of 22Na and 36Cl were measured . Under short-circuit conditions there was little net flux of either ion in the absence of agonists . Addition of carbachol elevated net serosal-to-mucosal Cl flux to 1.71 mu eq.h-1.cm-2, whereas a smaller increase to 0.85 mu eq.h-1.cm-2 occurred with isoproterenol . Neither agonist altered net Na flux . The stimulated Isc accounted for 70% of the net Cl flux induced by carbachol and nearly 100% of that induced by isoproterenol . Replacement of Cl by gluconate or Na by choline abolished (carbachol) or greatly reduced (isoproterenol) the Isc, which could be restored in a dose-dependent fashion by ion restitution . Active ion transport was preferentially inhibited by basal (vs . apical) addition of ouabain, furosemide, or barium . The results provide evidence that cholinergic and beta-adrenergic agonists elicit active transmural Cl secretion . They further suggest that transport is dependent on the Na+-K+-adenosine-triphosphatase, a Na-Cl cotransport process, and a basal K conductance, all features of a secondary active Cl secretory mechanism. J Surg Oncol, 1989 Jun, 41(2), 134 - 8 Isolated soluble fractions from spleen cell culture supernatants induce tumor enhancement; Eijan AM et al.; Supernatants of spleen cell culture from small-tumor-bearing mice, large-tumor-bearing mice, and large-tumor resected mice were fractionated by Sephadex G-100 . The biological activity on tumor growth of all fractions was tested in vivo . It was found that only one fraction (MW: 220-250 kD) from spleen cell supernatants of small-tumor-bearing mice or large-tumor resected mice enhanced tumor growth . In spleen cell supernatants from large-tumor-bearing mice, two fractions had enhancing activity (MW: 220-250 and 100-10 kD) . Thus, the surgical resection of large tumor induced disappearance of enhancing activity from the fraction of lower molecular weight. J Clin Pathol, 1989 Jun, 42(6), 658 - 60 Enzyme immunoassay compared with cell culture and immunofluorescence for detecting genital chlamydia; Mumtaz G et al.; A novel enzyme immunoassay test (Pharmacia EIA) was evaluated against cell culture for the detection of chlamydial genital infection . Specimens were obtained from 525 patients (257 men and 268 women) . Sensitivity, specificity, predictive value of positive (PVP) and predictive value of negative (PVN) for the new test were, respectively, 83.6, 98.5, 94.4 and 95.1% for men and 86, 97.2, 87.8 and 96.8% for women . Discrepancies were further evaluated by repeating the EIA, and by direct immunofluorescence on the EIA transport buffer . The sensitivity, specificity, PVP and PVN of the EIA against the combination of cell culture and direct immunofluorescence were, respectively 85.9, 100, 100, and 95.5% for men, and 90.5, 98.1, 92.3 and 97.7% for women . Overall agreement between the EIA and the combination of cell culture and direct immunofluorescence was 97% . The Pharmacia EIA is rapid and simple to perform and does not require elaborate equipment. Zhongguo Yi Xue Ke Xue Yuan Xue Bao, 1989 Jun, 11(3), 195 - 9 {Studies on mechanism of carcinogenesis in cell culture . III . Butyric acid-induced phenotypic reversion of malignant transformed Syrian hamster lung cells (BHLB4)}; Xu K; The MNNG transformed Syrian hamster lung fibroblast cell line (BHLB4) established in our laboratory was treated with 2.0 mmol/L butyric acid . We obtained a butyric acid-dependent partially reversed cell line (ButB4) similar to normal cells in morphology, membrane properties, proliferation rate, colony-forming ability on solid agar culture, etc . However, when transplanted into nude mice, this cell line's tumorigenicity remained intact . Detection of cAMP levels in the cytoplasm showed much higher levels in ButB4 cells than in transformed cells . Butyric acid activity is evidently associated with changes of cAMP . In addition to phenotypical analysis, the karyotypes of ButB4 and BHLB4 were analyzed in detail . It was found that the disomy rate of C15 was significantly increased in ButB4 cells (73%) as compared with BHLB4 cells (33%) . These results show that butyric acid not only induces phenotypic reversion in BHLB4 cells directly, but can also selectively kill C15 monosomy cell clones, allowing rapid growth of C15 disomy cell clones . Butyric acid may also influence maintenance of the reversion phenotype. Brain Res Bull, 1989 Jun, 22(6), 1049 - 52 Further studies on the identification of microglia in mixed brain cell cultures; Glenn JA et al.; The investigation of brain microglia in primary cultures of dissociated cerebral cortical cells has been continued here utilizing a histochemical procedure for thiamine pyrophosphatase, which selectively stains microglia in whole tissue . This procedure also selectively stained a subpopulation of cells in the cortical cultures . The stained cells were small and exhibited quite variable morphology; from these features, a corresponding cell population could be identified in viable cultures . The stained cells, which were distinct from previously identified macrophage forms, were also distinguished from similar appearing cell types--small neurons and oligodendrocytes . Based on their staining properties, morphology, and distinction from other cell types, the identified cells are proposed as equivalents of ramified microglia. Vet Microbiol, 1989 Jun, 20(2), 99 - 109 Evaluation of techniques to demonstrate foot-and-mouth disease virus in bovine tongue epithelium: comparison of the sensitivity of cattle, mice, primary cell cultures, cryopreserved cell cultures and established cell lines; House C et al.; Tongue epithelia infected with each of the 7 serotypes of foot-and-mouth disease virus (FMDV) were used to evaluate in vivo and in vitro systems for the detection of FMDV . Cattle inoculated by the intradermal route in the tongue (IDL) and suckling mice inoculated intraperitoneally were compared for susceptibility to FMDV with freshly prepared bovine thyroid cell cultures; cultures from cryopreserved bovine thyroid, bone marrow, mammary gland, myocardium, tongue, ovary and kidney cells; cultures from cryopreserved embryonic ovine kidney, newborn ovine kidney, ovine testicle, bone marrow, and chloroid plexus cells; and the continuous porcine kidney cell lines MVPK-1 and S6 . The mean titers determined for each serotype in each system were statistically compared . The FMDV titers obtained in freshly prepared bovine thyroid cell cultures and by cattle IDL inoculation were the highest and were statistically indistinguishable . The titers obtained by suckling mouse inoculation were significantly lower than the titers obtained in thyroid cultures for serotypes A, C, Asia 1, and SAT 3 . The cattle IDL assay was significantly more sensitive than the mouse assay for serotype A . The cell cultures from the cryopreserved newborn ovine kidney and embryonic ovine kidney were significantly less susceptible to serotype Asia 1 when compared with the fresh bovine thyroid cultures, but not significantly different when compared with the cattle assay for all serotypes . Cryopreservation of bovine thyroid cells directly after trypsinization resulted in the loss of susceptibility to FMDV serotype SAT 2 . The other cryopreserved cell culture systems exhibited no or minimal susceptibility to all 7 serotypes, or exhibited considerable inconsistency . The established cell lines MVPK-1 and S6 were not susceptible to serotype A, and were less sensitive to serotype C than other culture systems . Quality control of cell cultures used to evaluate field specimens for FMDV was critical . The cell cultures of cryopreserved ovine kidney cells provided the most practical diagnostic system. Vet Microbiol, 1989 Jun, 20(2), 131 - 42 Quantitation, biological and physicochemical properties of cell culture-adapted porcine epidemic diarrhea coronavirus (PEDV); Hofmann M et al.; The porcine epidemic coronavirus (PEDV), tentatively classified as a coronavirus, was adapted to Vero cells and a plaque test developed for infectivity titration, allowing us to test the biological and biophysical properties of the virus . Growth kinetics showed peak titers of 10(5.5) plaque-forming units ml-1 15 h after infection . Filtration experiments and electron microscopy revealed a particle diameter between 100 and 200 nm . The buoyant density of the virus was 1.18 . The particle lost its infectivity on treatment with lipid solvents . Virus replication could not be inhibited by 5-iodo-2'-deoxyuridine . PEDV was moderately stable at 50 degrees C, but heat sensitivity was not altered by divalent cations . At 4 degrees C, the virus was stable between pH 5.0 and 9.0, but at 37 degrees C stability was restricted to the pH range 6.5-7.5 . Viral infectivity was not impaired by ultrasonication or by multiple freezing and thawing . PEDV was not neutralized by transmissible gastroenteritis virus antiserum . On the basis of the tests carried out, PEDV is a pleomorphic, enveloped RNA virus with a particle diameter of approximately 150 nm and a buoyant density of 1.18 . Infectivity depends on the presence of trypsin, and infected cells show a tendency to fuse and to form syncytia . All of these properties, as well as its physicochemical characteristics, allow PEDV to be classified as a coronavirus. J Neurosci Res, 1989 Jun, 23(2), 234 - 9 Induction of protooncogene fos by extracellular signals in primary glial cell cultures; Condorelli DF et al.; In the present study various extracellular factors, acting through different second messenger systems, were examined for their capacity to increase the level of c-fos mRNA in primary glial cell cultures . In particular EGF, 12-O-tetradecanoylphorbol 13-acetate, the beta-adrenergic agonist isoproterenol, and the glutamate agonists, ibotenic and quisqualic acid, were studied . All the extracellular stimuli tested induced a rapid and transient increase in c-fos mRNA level in glial cell cultures regardless of the signal transduction pathway and the final effect on cell proliferation. J Clin Microbiol, 1989 Jun, 27(6), 1159 - 62 Clinical experience with cytomegalovirus isolation using conventional cell cultures and early antigen detection in centrifugation-enhanced shell vial cultures; Leland DS et al.; A total of 1,915 clinical samples was inoculated by low-speed centrifugation into shell vials (Bartels Immunodiagnostics, Bellvue, Wash.) containing cover slip monolayers of MRC-5 fibroblasts . At 1 and 2 days postinoculation, one cover slip was stained by an indirect immunofluorescence technique using a monoclonal antibody (Biotech Research Laboratories for Dupont, Billerica, Mass.) to cytomegalovirus (CMV) early antigen (EA) . Clinical samples were also inoculated into three MRC-5 or MRHF cell cultures which were observed for 30 days for the appearance of a cytopathic effect (CPE) . Of 157 CMV-positive samples, 92 (59%) were identified by centrifugation-enhanced EA (CE-EA) and 131 (83%) produced a CPE . CE-EA was less sensitive than CPE for all types of samples, although 17% of CMV-positive samples were detected by CE-EA alone . Evaluation of the CMV status of patients with CE-EA-positive-CPE-negative samples indicated that these samples likely represented true CMV-positive results . The average elapsed time between culture inoculation and identification of CMV decreased as follows when both CE-EA and CPE, rather than CPE alone, were used: urines, 15 to 7 days; buffy coats, 18 to 9 days; lung samples, 13 to 8 days; throat samples, 18 to 7 days . Although CE-EA was less sensitive than 30-day cell culture, both CE-EA and CPE were identified as valuable in CMV detection, and neither could be discontinued without a decrease in the CMV isolation rate or an increase in the turnaround time. Toxicol Lett, 1989 Jun, 47(3), 249 - 57 The effects of 1,3-dinitrobenzene and mono-(2-ethylhexyl)phthalate on hormonally stimulated lactate and pyruvate production by rat Sertoli cell cultures; Williams J et al.; Lactate and pyruvate production by rat Sertoli cell cultures was measured after treatment with two toxicants (1,3-dinitrobenzene, DNB; mono-(2-ethylhexyl)phthalate, MEHP) in the presence or absence of follicle-stimulating hormone (FSH) or dibutyryl-cAMP (dbcAMP) . 1,3-DNB together with FSH or dbcAMP produced increases in media lactate and pyruvate concentrations significantly greater than those induced by individual treatments . MEHP in conjunction with either hormone also produced greater increases in lactate concentrations compared with separate additions . However, MEHP produced a significant diminution in the hormonal stimulation of pyruvate secretion . Thus, 1,3-DNB appears to act independently of these hormones in stimulating the secretion of both metabolic products, whereas MEHP interferes with the hormonal stimulation of pyruvate (but not lactate) production. Endocrinology, 1989 Jun, 124(6), 2791 - 8 The synergistic effects of His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 on growth hormone (GH)-releasing factor-stimulated GH release and intracellular adenosine 3',5'-monophosphate accumulation in rat primary pituitary cell culture; Cheng K et al.; His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (GHRP-6) stimulated GH release from rat primary pituitary cells in a time- and dose-dependent manner . Stimulation was observed after a 15-min, but not a 4-h, incubation . The concentrations of GHRP-6 required for half-maximal and maximal stimulation were 7 x 10(-9) and 10(-7) M, respectively . GH release induced by GHRP-6 was not affected by the addition of either naloxone or the GRF antagonist {N-Ac-Tyr1,D-Arg2}GRF-(1-29)-NH2 . The latter inhibited GRF-stimulated GH release by shifting the dose-response curve to the right . His-D-Trp-D-Lys-Trp-D-Phe-Lys-NH2, an analog of GHRP-6, inhibited GH release stimulated by GHRP-6 without affecting that induced by GRF . When present together at maximal concentrations, GHRP-6 and GRF produced a synergistic effect on GH release . GHRP-6 had no effect on intracellular cAMP levels, whereas GRF increased intracellular cAMP concentrations by 3-fold . Combined treatment of pituitary cells with GRF and GHRP-6 resulted in a potentiation of the GRF-induced increase in cAMP levels . Basal GH release was reduced by 30% after pretreatment with GHRP-6 (10(-7) M) for 1 h . Pretreatment with GHRP-6 also decreased the subsequent response to GHRP-6, but not GRF . In contrast, pretreatment with GRF for 1 h had no effect on the subsequent action of GHRP-6 or GRF on GH release . The desensitization induced by GHRP-6 was completely reversed within 1 h after removal of the peptide . Results from this study indicate that GHRP-6 and GRF stimulated GH release from somatotrophs via different receptors and through discrete mechanisms. In Vitro Cell Dev Biol, 1989 Jun, 25(6), 564 - 70 Observation of production of immunoactive prolactin by normal human connective tissue in cell culture; Chapitis J et al.; Data from our in vitro studies indicate a new source of prolactin (PRL)-like activity, normal human connective tissue . Fascial cells from primary culture and subsequent passages produced an extracellular antigen which specifically reacted in a radioimmunoassay RIA developed to detect human pituitary PRL . An initial peak or first surge of fascial PRL-like activity occurred between 4 and 15 d in primary culture . Ibuprofen, cytotoxic levels of 0.01% azide, or 7.5 mM EDTA and medium lacking serum {fetal bovine serum (FBS)} significantly (P less than or equal to 0.05) reduced PRL-like activity levels, whereas female steroids, 257 to 342 milliosmolarity, 1 to 3.6 mg/ml glucose, 2 to 20% FBS, and dialyzed FBS (MWCO approximately 1 kDa) were without effect . Optimum production of PRL-like activity occurred at pH 7.3 . A second surge began after 18 d and continued until passage indicating that perhaps two populations of cells produced PRL-like activity in primary culture . Production of PRL-like activity by cells from early passages (1 and 2) became detectable at confluence, was serum-dependent, showed two patterns (tonic, rising to plateau), and averaged 3.2 fg.cell-1.3 d-1 feed interval . Cells from late passages showed morphologic damage from repetitive trypsinization, aging, and reduced production of PRL-like activity with aberrant production pattern . Production of PRL-like activity was maintained in an unusual long-term culture . These in vitro studies demonstrate the most recently recognized and ubiquitous source of human extrapituitary PRL or PRL-like activity, normal connective tissue (fascia). Endocrinology, 1989 Jun, 124(6), 2914 - 9 Stimulation of beta-endorphin secretion by corticotropin-releasing factor in primary rat Leydig cell cultures; Eskeland NL et al.; CRF, a hypothalamic peptide, is a potent stimulator of POMC synthesis and secretion in the pituitary . POMC biosynthesis has been documented in the testis, specifically in Leydig cells, and recent studies suggest that CRF is synthesized locally in the testis . A reverse hemolytic plaque assay and immunocytochemistry with Leydig cell-specific antibodies were used to study the effect of CRF on secretion of the POMC peptide beta-endorphin (beta EP) from normal rat primary Leydig cell cultures . In enriched Leydig cell preparations incubated with beta EP antiserum (diluted 1:50) then with complement (diluted 1:25), approximately 15% of immunocytochemically identified Leydig cells formed plaques . Preabsorption of the antiserum with beta EP (2 micrograms/microliters antiserum) overnight at 4 C abolished the formation of plaques . Increasing concentrations of CRF (from 10(-1) to 10(-7) M) resulted in an approximately 80% increase in both the percentage of plaque-forming cells and the mean plaque size . When the CRF antagonist CRF-(9-41) (10(-6) M) was added in the presence of CRF, the increases in plaque number and average size did not occur . These results demonstrate that Leydig cells have functional CRF receptors and that beta EP secretion from these cells is stimulated by CRF. Cell Immunol, 1989 Jun, 121(1), 88 - 98 The role of suppressor factors in the regulation of immune responses by ultraviolet radiation-induced suppressor T lymphocytes . II . Activity of suppressor cell culture sonicates; Yee GK et al.; The purpose of this study was to determine whether multiple types of suppressor factors play a role in the regulation of immune responses by ultraviolet radiation-induced suppressor T lymphocytes (UV Ts) . The UV Ts were induced by applying contact allergens to the ventral, unirradiated skin of mice exposed 5 days earlier to UVB radiation . Previous studies indicated that supernatants from cultures containing UV Ts, normal lymphocytes, and hapten-modified cells suppressed contact hypersensitivity (CHS) in vivo and cytotoxic T lymphocyte (CTL) generation in vitro in a hapten-specific manner . In this report, cell-free lysates from sonically disrupted UV Ts were examined for their ability to suppress these responses . When lysates were injected into normal animals at the time of sensitization, they inhibited CHS in a hapten-nonspecific manner . In addition, the lysates suppressed not only the induction but also the elicitation of CHS, and they suppressed the generation of CTL . Lysates prepared from spleen cells obtained from non-UV-irradiated mice or UV-irradiated, unsensitized mice failed to inhibit either response . Moreover, in contrast to the lysates, the hapten-specific UV Ts culture supernatants inhibited the induction but not the elicitation of CHS . These results suggest that both hapten-specific and nonspecific inhibitory factors may participate in the regulation of immune responses by UV Ts. Cell Immunol, 1989 Jun, 121(1), 74 - 87 The role of suppressor factors in the regulation of immune responses by ultraviolet radiation-induced suppressor T lymphocytes . I . Activity of suppressor cell culture supernatants; Yee GK et al.; The purpose of this study was to determine whether soluble suppressor factors are involved in the regulation of immune responses by ultraviolet radiation-induced suppressor T lymphocytes (UV Ts) . The UV Ts were induced by applying contact allergens to the ventral, unirradiated skin of mice that had been exposed 5 days earlier to UVB radiation . Supernatants from cultures that contained a mixture of UV Ts, normal responder lymphocytes, and hapten-modified stimulator cells were injected iv into normal recipients at the time of sensitization; they inhibited the induction of contact hypersensitivity (CHS) in vivo in an hapten-specific manner . The supernatants similarly suppressed the generation of specific cytotoxic T lymphocytes (CTL) in vitro . Moreover, supernatants from cultures that contained either UV Ts alone or UV Ts in combination with either the responder or the stimulator cells failed to suppress the CHS and CTL responses . These results suggest that hapten-specific inhibitory factors may participate in the regulation of immune responses by suppressor cells generated by epicutaneous sensitization of UV-irradiated mice. Agents Actions, 1989 Jun, 27(3-4), 448 - 50 PMN stimulation by factors from IL-1-treated human synovial cell cultures; Watson ML et al.; Following exposure of cultured human synovial cells to human recombinant interleukin 1 alpha (IL-1 alpha), we demonstrate the appearance of factors in the supernatant which stimulate human polymorphonuclear leukocyte (PMN) locomotion and elevate intracellular free calcium ({Ca++}i) . The production of these factors can be abolished by actinomycin D or dexamethasone but not by cyclo-oxygenase or lipoxygenase inhibitors . In vivo, the supernatant induces a rapid accumulation of PMNs in rabbit skin following intradermal injection . These activities were not due to IL-1 itself, tumour necrosis factor (TNF alpha) or granulocyte-macrophage colony-stimulating factor (GM-CSF) . Such factors may play an important role in inflammatory responses involving IL-1. Kisaengchunghak Chapchi, 1989 Jun, 27(2), 87 - 100 {Development of Eimeria tenella in MDBK cell culture with a note on enhancing effect of preincubation with chicken spleen cells}; Chai JY et al.; Eimeria tenella, an intracellular protozoan parasite infecting the epithelial cells of the ceca of chickens, causes severe diarrhea and bleeding that can lead its host to death . It is of interest that E . tenella first penetrate into the mucosal intraepithelial lymphocytes (IEL) before they parasitize crypt or villous epithelial cells . This in vitro study was undertaken to know whether the penetration of E . tenella into such a lymphoid cell is a beneficial step for the parasite survival and development . Three sequential experiments were performed . First, the in vitro established bovine kidney cell line, MDBK cells, were evaluated for use as host cells for E . tenella, through morphological observation . Second, the degree of parasite development and multiplication in MDBK cells was quantitatively assayed using radioisotope-labelled uracil (3H-uracil) . Third, the E . tenella sporozoites viability was assayed after preincubation of them with chicken spleen cells . E . tenella oocysts obtained from the ceca of the infected chickens were used for the source of the sporozoites . Spleen cells (E) obtained from normal chickens (FP strain) were preincubated with the sporozoites (T) at the E:T ratio of 100:1, 50:1 or 25:1 for 4 or 12 hours, and then the mixture was inoculated into the MDBK cell monolayer . Morphologically the infected MDBK cells revealed active schizogonic cycle of E . tenella in 3-4 days, which was characterized by the appearance of trophozoites, and immature and mature schizonts containing merozoites . The 3H-uracil uptake by E . tenella increased gradually in the MDBK cells, which made a plateau after 48-60 hours, and decreased thereafter . The uptake amount of 3H-uracil depended not only upon the inoculum size of the sporozoites but also on the degree of time delay (preincubation; sporozoites only) from excystation to inoculation into MDBK cells . The 3H-uracil uptake became lower as the preincubation time was prolonged . In comparison, after preincubation of sporozoites with spleen cells for 4 or 12 hours, the 3H-uracil uptake was significantly increased compared with that of control group . From the results, it was inferred that, although the penetration of E . tenella sporozoites into the lymphoid cells such as IEL is not an essential step, it should be at least a beneficial one for the survival and development of sporozoites in the chicken intestine. Hum Cell, 1989 Jun, 2(2), 156 - 64 {Application of neuronal cell culture in human degenerative brain disorders}; Eto Y et al.; Neuronal cell culture system has been used for the study of pathochemical evaluations in human degenerative brain disorders, particularly for Krabbe's disease and neuronal ceroid lipofuscinosis . To understand the pathochemistry of Krabbe's disease, we added psychosine into neuronal cell cultures and psychosine treated cells showed the destruction of cytoskeleton and pathy intracellular changes . Electron microscopic finding showed the swelling of the mitochondria . Oligodendrocytes and Schwann cells were isolated from the brains and sciatic nerve of twitcher mouse as an authentic murine model of globoid cell leukodystrophy . Oligodendroglial cells cultured for 22 days were stained by anti-galactocerebroside antibodies . In twitcher oligodendrocyte processes were wirelike and progressively degenerated and there were few membranous expansion . Schwann cells from twitcher could not elongated their processes . These data suggest that psychosine might be important factor to result in these pathological conditions . Furthermore, we studied the effect of protease inhibitors, E-64 on dissociated primary cultures from fetal rat brain . After treated with E-64 in a concentration from 0.1-50 micrograms/ml, numerous cytoplasmic accumulations appeared in neuronal cells . These morphological pictures resemble with those of neuronal ceroid lipofuscinosis, Batten disease . We will discuss the relationship between the deficiency of catepsin H in Batten disease and inclusion bodies found in E-64. Hum Cell, 1989 Jun, 2(2), 122 - 31 {Recent advances in neural cell culture}; Kim SU; Cells isolated from the avian and mammalian central and peripheral nervous system and cultured in vitro provide an opportunity to study in situ properties of neurons and glial cells under relatively simple and carefully controlled conditions . Since Harrison's success in maintaining in vitro embryonic frog spinal cord 80 years ago, neural tissue culture has developed into an important and versatile discipline of neuroscience . The techniques developed in the past fall into four broad classes: Explant cultures, which are explanted from specific neuroanatomic loci to substrates as small tissue fragments . Dissociated cell cultures, which involve the seeding of enzymatically or mechanically dispersed cells on various attachment substrates . Reaggregate cultures, which require re-association of dissociated cells into small aggregates . Purified cell populations, which are prepared by the isolation of different cell types by gradient centrifugation or other separation techniques . These cultures have been utilized in studying various aspects of brain development and function . In this review several areas of significant and stimulating development in neural cell culture have been documented . They include formulation of serum-free medium, effects of growth factors, utilization of cell type-specific markers, and isolation and culture of purified neuronal/glial cells. Proc Natl Acad Sci U S A, 1989 Jun, 86(11), 4122 - 6 Phospholipids containing polyunsaturated fatty acyl groups are mitogenic for normal mouse mammary epithelial cells in serum-free primary cell culture; Imagawa W et al.; Epithelial cells obtained by collagenase digestion of mammary glands from virgin BALB/c mice were cultured in collagen gels in serum-free basal medium containing insulin (10 micrograms/ml), to which lipids or growth factors were added . Synthetic phospholipids were added as liposomes . Dilinoleoyl phosphatidic acid or phosphatidylserine or epidermal growth factor stimulated multifold growth . The optimum mitogenic effect of the phospholipids was dependent upon the presence of a polyunsaturated fatty acid esterified to the sn-2 position of the glycerol moiety . Dilinoleoyl phosphatidylcholine also stimulated growth but was generally less stimulatory than phosphatidylserine or phosphatidic acid, and phosphatidylethanolamine did not stimulate growth . Studies using phospholipids radiolabeled in either the sn-2 fatty acyl group or the glycerol backbone showed that the relative effect of phospholipids on growth did not correlate directly with the extent of their incorporation into cellular lipid, indicating that phospholipid turnover was the more important determinant for mitogenesis . Analysis of phosphatidic acid-stimulated growth suggested that both cAMP-dependent and cAMP-independent pathways were involved . Thus, mitogenic phospholipids stimulate proliferation by activating (directly or indirectly) multiple growth-regulatory pathways in mammary epithelial cells. J Biol Chem, 1989 May 25, 264(15), 8542 - 8 Isolation and characterization of an unprocessed extracellular myeloperoxidase in HL-60 cell cultures; Hur SJ et al.; Extracellular myeloperoxidase of human myeloid leukemia HL-60 cells was purified to homogeneity from its culture supernatant by ammonium sulfate fractionation, CM-Sepharose column chromatography, and monoclonal antibody-Sepharose affinity column chromatography . The yield of enzyme activity was 38% that of the ammonium sulfate fraction . On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the purified preparation gave a single band of approximately 84 kDa . Analysis of protein blot with antibodies specific for the light and heavy chains of myeloperoxidase indicated that the enzyme contained a light and a heavy chain in a single polypeptide . The amino-terminal amino acid sequence of the enzyme began at amino acid residue 155 of the 745-amino acid sequence predicted from myeloperoxidase cDNA, indicating that the enzyme consisted of 591 amino acids . Sucrose density gradient centrifugation of the enzyme showed that the enzyme was a monomeric form . In pulse-chase experiments on HL-60 cells with {35S}methionine, pulse-labeled myeloperoxidase precursors were shown to be processed to a light chain and a heavy chain of cellular enzyme . During a 3-day chase period, newly formed processed monomeric enzyme was converted to a dimeric form. J Natl Cancer Inst, 1989 May 3, 81(9), 669 - 75 Macrophage activation by the polysaccharide arabinogalactan isolated from plant cell cultures of Echinacea purpurea; Luettig B et al.; In this study, acidic arabinogalactan, a highly purified polysaccharide from plant cell cultures of Echinacea purpurea, with a molecular weight of 75,000, was effective in activating macrophages to cytotoxicity against tumor cells and micro-organisms (Leishmania enriettii) . Furthermore, this polysaccharide induced macrophages to produce tumor necrosis factor (TNF-alpha), interleukin-1 (IL-1), and interferon-beta 2 . Arabinogalactan did not activate B cells and did not induce T cells to produce interleukin-2, interferon-beta 2, or interferon-gamma, but it did induce a slight increase in T-cell proliferation . When injected ip, this agent stimulated macrophages, a finding that may have therapeutic implications in the defense against tumors and infectious diseases. Zhonghua Yi Xue Za Zhi, 1989 May, 69(5), 260 - 3, 18 {Studies on the hepatitis B virus in cell culture: I . Expression of cloned HBV DNA in the HEP G2 cell line}; Wen YM; To study the interactions between HBV and host cells, cloned adr subtype HBV DNA dimer was used to transfect Hep G2 cell line . Five days after transfection, HBeAg could be detected in the supernatant and reached its peak on the 11th day . It was still positive on the 25th day . In contrast, HBsAg was only positive on the 8th day, and gradually increased until the 25th day when the amount of HBsAg was still rising . Supernatant of HBeAg positive samples was collected and after ultracentrifugation, was checked by electron microscopy . HBV like particles of 42 nm in diameter were detected . The prospect of employing this transient cell expression system for studies of HBV replication, inhibitory effects of drugs and immunological factors are discussed. Vopr Virusol, 1989 May-Jun, 34(3), 330 - 3 {The inhibiting effect of anti-viral chemical substances on a suspended cell culture}; Pshenichnov AV et al.; The inhibiting effect of some antiviral drugs on suspension BHK-21 and LECH cell cultures was demonstrated by measuring of the proliferative cytotoxicity and by several changes in cell metabolism . The role of the observed phenomenon in the objective evaluation of the effect of the antiviral drugs in vitro is discussed. J Neurosci, 1989 May, 9(5), 1540 - 54 Studies of nerve-muscle interactions in Xenopus cell culture: fine structure of early functional contacts; Buchanan J et al.; We have studied the fine structure of nerve-muscle contacts during the first few hours of synaptogenesis in embryonic Xenopus cell cultures . The precise timing of contact was achieved by manipulating isolated spherical myocytes (myoballs) into contact with growth cones or neurites of co-cultured spinal neurons . The contacts were shown to be functional by whole-cell voltage-clamp recording of nerve-evoked synaptic currents in the muscle cell . The ultrastructure of these functional contacts was examined by thin-section electron microscopy . In total, 20 nerve-muscle pairs were studied with contact periods ranging from 20 min to 12 hr, during which time a substantial increase in the amplitude of synaptic currents occurred . The structure of noncontacting cells and of nerve-muscle contacts formed between the cells by natural encounters in 1-d-old cultures were also examined in order to identify the features and the time course of morphological differentiation of early functional contacts . Prominent features of the contact area during the first few hours included: close apposition of the nerve and muscle membranes, greater frequency of coated pits and vesicles, and thickening of postsynaptic muscle membrane . Occasionally, clusters of clear vesicles occurred near presynaptic membrane, but no further sign of active zone differentiation was observed . In comparison, definitive active zone structure, well-formed extracellular basal lamina, and widened cleft were seen in natural contacts less than 24 hr old . This study of the identified functional contacts may help us to understand the structural basis for early nerve-muscle interaction and the functional significance of various synaptic specializations. J Neurosci, 1989 May, 9(5), 1523 - 39 Studies of nerve-muscle interactions in Xenopus cell culture: analysis of early synaptic currents; Evers J et al.; We have studied the spontaneous and nerve-evoked synaptic currents during the initial period of nerve-muscle contact in Xenopus cell cultures . The precise timing of the contact was achieved by physically manipulating embryonic muscle cells into contact with co-cultured spinal neurons . Previous studies have shown that physical contact of the muscle membrane induces pulsatile release of acetylcholine (ACh) from the growth cone of these neurons, resulting in spontaneous synaptic currents (SSCs) in the muscle cell within seconds following the contact . In the present work, we first showed that these SSCs at the manipulated nerve-muscle contacts are similar to those observed at naturally occurring synapses . We then examined the possible cellular mechanisms responsible for the marked variation in SSC amplitude and showed that it most likely results from differences in either the amount of ACh contained in each release event or the extent of close membrane apposition near the release sites . During the first 20 min following the nerve-muscle contact, there was an increase in the frequency and mean amplitude of the SSCs . During a similar period, the evoked synaptic currents (ESCs), which were induced by suprathreshold electrical stimulation of the neuronal soma, also showed an increase in the mean amplitude and a reduction in the delay of onset following the stimulus . These postcontact changes in the efficacy of synaptic transmission may be related to an increase in the total area of close membrane apposition between the nerve and muscle cells . This was suggested by the finding that neurite-muscle adhesion increases over a similar postcontact period . The transition from low- to high-efficacy transmission during the early phase of contact may reflect the process of selective adhesion between the cells, and thus signify the formation of specific synapse . Analysis of the fluctuation in the ESC amplitude at the early nerve-muscle contact suggests that evoked release of ACh occurs as multiples of a quantal unit . However, this unit is apparently related to only a small subpopulation of SSCs of relatively high amplitudes.(ABSTRACT TRUNCATED AT 400 WORDS) Rev Inst Med Trop Sao Paulo, 1989 May-Jun, 31(3), 146 - 50 Differences in the antigenic profile of bloodstream and cell culture derived trypomastigotes of Trypanosoma cruzi; da Silva AM et al.; A comparative study of the antigenic profile of bloodstream and cell culture derived trypomastigotes showed many differences in their components . Using mouse anti-T . cruzi antibodies the differences were located mostly in the 120 kDa band, whereas using chagasic patient sera the differences were located in the 85 and 52 kDa bands . These findings might explain known physiological differences between trypomastigotes obtained from cell culture and from infected blood . A brief report of this work has already been published. Zentralbl Bakteriol, 1989 May, 271(1), 77 - 84 Titration of Coxiella burnetii in Buffalo green monkey (BGM) cell cultures; Schneider W; Titration of Coxiella burnetii, strain Nine Mile, phase I, and strain Frankfurt, phase II, in Buffalo green monkey (BGM) cover slip cell cultures yielded reproducible infectivity titers after centrifugation of infected cell cultures (3000 g, 30 min, 37 degrees C) and a subsequent 4-day incubation at 37 degrees C in Minimal Essential Medium (MEM) . Compared to other titration procedures (plaque assays, titration in embryonated chicken eggs), this technique proved to be fast, less laborious and economical. Basic Res Cardiol, 1989 May-Jun, 84(3), 326 - 31 Selective percutaneous "biopsy" of atheromatous plaque tissue for cell culture; Bauriedel G et al.; The combination of percutaneous atherectomy and angioscopy enabled a selective "biopsy" of protruding atheromatous plaque material from 11 patients with arterial occlusive disease . The removed specimens were cultivated as adhering explants or single cells were obtained by enzymatic disintegration . The vast majority of the cultivated cells resembled fibroblasts, but could be identified as smooth muscle cells by their smooth muscle alpha-actin content . Proliferation rate was slow with 0.1 doublings per day . Endothelial cells were not observed by immunologic criteria . The described biopsy technique and in vitro evaluation of cultured human atheromatous plaque material may be useful for a better understanding of atherogenesis. J Infect, 1989 May, 18(3), 269 - 78 Rapid detection of influenza virus infections in human fetal lung diploid cell cultures; Phipps PH et al.; Haemadsorbing foci were found in human fetal lung (HFL) diploid cell cultures 12 h after inoculation with influenza viruses A and B . The size and number of the foci were maximal after 48 h of incubation, being limited by production of an unidentified inhibitor . By contrast, inoculation with parainfluenza virus type 3 led to haemadsorption which increased during 10 days of incubation . For the detection of influenza viruses A and B maximum sensitivity was achieved by changing the medium, the day before use to one that was serum free . The number of foci at 15.5 h post-infection and infectivity for primary African green monkey kidney (AGMK) cultures were similar . Virus infectivity and production of haemagglutinin in HFL cells were entirely cell-associated; they were not affected by treatment with trypsin . Nevertheless, influenza viruses A and B antigens were identified in the infected cells by means of immunofluorescence at 15.5 h and virus was recovered by passage of frozen and thawed cells in AGMK cultures . For rapid routine diagnosis of viral infections, the early haemadsorption test was shown to have the same sensitivity as immunofluorescence tests on specimens and virus detection by the shell-vial technique but was cheaper and simpler to perform. J Clin Microbiol, 1989 May, 27(5), 826 - 8 Comparison of DNA probe, monoclonal antibody enzyme immunoassay, and cell culture for the detection of Chlamydia trachomatis; LeBar W et al.; A total of 201 endocervical specimens were obtained from patients with a clinical or epidemiological history suggestive of chlamydial infection . These specimens were tested by DNA probe (Gen-Probe, San Diego, Calif.) and the IDEIA III (Boots-Celltech, Berkshire, United Kingdom) monoclonal antibody enzyme immunoassay and compared with cell culture for detection of Chlamydia trachomatis . Discrepancies between cell culture and antigen detection methods were resolved by direct fluorescent-antibody testing . In a population with a 17.4% prevalence, the sensitivities and specificities of these assays were 82.8 and 99.4%, respectively, for the DNA probe assay and 97.1 and 98.1%, respectively, for the IDEIA III. Anat Rec, 1989 May, 224(1), 29 - 42 Primary cell culture and morphological characterization of ventricular myocytes from the adult newt, Notophthalmus viridescens; Tate JM et al.; Previous work has demonstrated that adult newt cardiac myocytes possess a proliferative ability in response to an experimentally induced injury, in vivo . This study describes an in vitro model in which the proliferative events of the adult cardiac myocyte may be studied . Ventricles were minced and then enzymatically dissociated in a Ca++- and MG++-free salt solution containing 0.5% trypsin and 625 U/ml of CLS II collagenase for 8 to 10 hours at 25 degrees C . Enzyme digests were preplated and then cultured on bovine corneal endothelial-derived basement membrane "carpets" in either serum-free or serum-supplemented modified Leibovitz's medium for up to 30 days . Light and transmission electron microscopic characterization demonstrated that a majority of the myocytes underwent an initial period of disorganization characterized by a "rounding up" of the cell and a loss of myofibrillar organization . Once the myocytes had attached to the culture substratum they began to spread out, underwent a reassembly of their contractile elements, resumed spontaneous contractions, and demonstrated ultrastructural evidence of protein synthesis . Mitosis was observed in several myocytes 8 to 15 days following isolation . In 15-day serum-supplemented and serum-free cultures, 6.5% +/- 0.9% and 8.1% +/- 1.4% of the myocytes were binucleated, respectively . These results demonstrate that adult newt ventricular myocytes can be successfully placed into primary culture and are capable of undergoing mitosis . This work may be considered as a foundation for future investigations which will focus on the mechanisms which control cardiac myocyte proliferation. J Cell Sci, 1989 May, 93 ( Pt 1), 133 - 42 Effects of vitamin A on growth and differentiation of human tracheobronchial epithelial cell cultures in serum-free medium; Chopra DP et al.; Differentiating epithelial cell cultures from human tracheobronchial epithelium have been propagated in serum-free medium . The major objective of this study was to examine the trophic effects of vitamin A on cell multiplication and morphology of the tracheal cell cultures . The cellular responses were analyzed in terms of growth kinetics, morphological and ultrastructural alterations and secretion of glycoconjugates . Cell cultures in control medium exhibited characteristics of epithelial cells including microvilli on cell surfaces, desmosomes between cells, and numerous secretory vesicles in the cytoplasm . Vitamin A at 10(-6) M and 10(-7) M inhibited cell replication and enhanced the secretion of {3H}glucosamine-labeled glycoconjugates . Further, vitamin A increased the production of plasma membrane vesicles and acquisition by the cells of a highly secretory ultrastructure . This in vitro model of human epithelial cells will be important in the investigation of various aspects of growth and differentiation. Acta Virol, 1989 May, 33(3), 290 - 6 Detection of swine pox and buffalo pox viruses in cell culture using a protein A-horseradish peroxidase conjugate; Mohanty PK et al.; Buffalo pox virus antigen was detected in Vero cells and swine pox virus antigen in the cytoplasm and nucleus of PK-15 and IB-RS-2 cells as early as 6 hr post infection (p.i.) by indirect immunoperoxidase technique using a Protein A-horseradish peroxidase (HRP) conjugate . The viral antigens localized in the cytoplasm of infected cells were the most prominent after 24 hr p.i. J Gen Virol, 1989 May, 70 ( Pt 5), 1093 - 104 Anatomical basis of Thogoto virus infection in BHK cell culture and in the ixodid tick vector, Rhipicephalus appendiculatus; Booth TF et al.; Infection by Thogoto (THO) virus, a tick-borne virus related to the orthomyxoviruses, has been compared in vertebrate cell culture and in Rhipicephalus appendiculatus ticks using infectivity titrations, immunofluorescence, and immune electron microscopy with colloidal gold markers to detect cell surface and intracellular antigens . Morphogenesis of THO virus in cell culture was similar to that of influenza virus, with polymorphic virus particles budding at the plasma membrane . In the tick, THO viral infection caused no obvious pathology; virions or budding profiles were not observed in electron micrographs, although replication, trans-stadial persistence and transmission to a susceptible host occur . THO virus was not detected in the salivary glands of trans-stadially infected ticks until about 7 days after the commencement of feeding on a host . The synganglion (brain) appears to be the major organ involved in trans-stadial persistence of the virus; viral antigens were detected in the neural cortex (cell bodies) but not in nerve fibres and axons . The detection of THO viral antigen in basement membranes and connective tissue, but its absence from nerve fibres, suggests that dissemination occurs via the haemolymph rather than a neural route. Chem Res Toxicol, 1989 May-Jun, 2(3), 157 - 61 Intracellular activation of cytotoxic agents: kinetic models for methylnitrosoureas and N-methyl-N'-nitro-N-nitrosoguanidine in cell culture; Weinkam RJ et al.; The cytotoxic activity of N-methyl-N-nitrosourea (MNU), streptozotocin, and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was determined in cell culture by using a P388 cell growth rate inhibition assay . These agents appear to have very different activities when inhibition is related to the agent concentration in the culture medium: ED50(C0) = 40 microM for MNNG to 875 microM for streptozotocin . The mechanism of action of these three agents involves conversion to the active methanediazonium ion and subsequent methylation of cellular macromolecules . As a consequence, the rates of conversion of the parent agent to the methylating species in the medium and within the cell are important parameters that also need to be considered to reach a more detailed understanding of the mechanism of action . In order to do this, a kinetic model has been developed to calculate the concentration of drug that is converted to active methylating species within the cell during the assay incubation period . The use of cell culture kinetic models was extended from simple compounds activated through solvolytic reactions (nitrosoureas) to an agent that undergoes selective intracellular activation (MNNG) . By use of measured values for initial drug concentration, incubation time, and cell volume, as well as extracellular and intracellular chemical activation rate constants, the intracellular concentration, {P4}, which represents the cumulative intracellular reaction products formed during the incubation period, was calculated and related to cytotoxicity . All three agents showed an ED50{P4} between 140 and 180 microM, and for MNNG, this ED50 was independent of extracellular sulfhydryl concentration.(ABSTRACT TRUNCATED AT 250 WORDS) G Chir, 1989 May, 10(5), 273 - 6 {Diagnostic use of the cell culture technique in a case of postoperative saccate lymphorrhea}; Modesti M et al.; The Authors demonstrated the presence of tumour cells by an in vitro culture of the cells from the pellet of a postoperative saccate effusion, when no tumor cells were evident by the cytologic examination of the effusion . The ultrastructural features and the immunocytochemical characteristics of the cell line were analyzed and these data confirmed its malignant nature . It allowed a firm diagnosis, a correct therapy and prognosis. Arch Exp Veterinarmed, 1989 May, 43(3), 345 - 50 {The use of embryonic chicken liver cell culture for the diagnosis of virus infections in hens}; Pfirschke CD; Embryonic chicken liver cell culture has proved to be an appropriate and sensitive substrate for propagation of virus of infectious laryngotracheitis, infectious bronchitis, infectious bursitis, egg-drop syndrome, and CELO virus of fowl . Microtest plates, too, were suitable for preparation of embryonic chicken liver cell culture as primary culture. Probl Endokrinol (Mosk), 1989 May-Jun, 35(3), 26 - 9 {Features of lipid peroxidation in patients with diabetes mellitus before and after therapy by a method of transplantation of human fetal islet cell cultures}; Pavlovskii MP et al.; The authors discussed the results of changes in the intensity of lipid peroxidation and antioxidant activity in 70 patients with type I diabetes mellitus (severe forms) before and in 32 patients after the transplantation of human fetal pancreatic islet cell cultures . Lipid peroxidation, antioxidant activity, indices of glycolysis and carbohydrate metabolism were investigated . In some cases metabolic derangement was noted against a background of a decrease in the end products of lipid peroxidation but in a majority of diabetic patients an increase in LPO intensity was noted against a background of raised antioxidant activity, high activity of glycolytic reactions and inhibition of Krebs' cycle . The greatest effect of transplantation was noted in a group of patients who had demonstrated high levels of lactate and the lactate-pyruvate ratio before transplantation . Therefore LPO indices can serve as a criterion of the selection of patients with insulin dependent diabetes mellitus for pancreatic endocrine tissue transplantation. Taiwan Yi Xue Hui Za Zhi, 1989 May, 88(5), 456 - 61 Effects of estrogen on progesterone receptor synthesis during endometrial cell culture; Chen TJ et al.; Endometrial cells from the hamster's uterus were grown as a monolayer during primary cell cultures and the progesterone receptor synthesis in the cultured cells was determined . The cells were found to be estrogen responsive . Production of the progesterone receptor in the cultured cells was enhanced by the presence of 17 beta-estradiol at physiological concentrations . A significant increase in specific binding of (3H) R5020 was observed after 24h of culture; by 48 h, a 2- to 3-fold augmentation in binding was noted . The increase in the progesterone receptor depended on the concentration of estradiol, with maximal response at about 1 nM . The progesterone receptor response was specific for estrogen . Testosterone or cortisol induced small or no response on the production of progesterone receptors . The progesterone receptor synthesis was inhibited by cycloheximide (10 micrograms/ml) or actinomycin D (10 micrograms/ml) . These results demonstrate that endometrial cell cultures can serve as a good in vitro system for the study of hormonal effects on progesterone receptor synthesis or other biochemical responses . We conclude that the progesterone receptor formation in the cultured endometrial cells is mediated via RNA and protein synthesis. Mol Biol (Mosk), 1989 May-Jun, 23(3), 772 - 82 {The effect of 5-azacytidine on the cell cycle and chromosome structure in cell cultures of swine embryonal kidney tissue}; Zatsepina OV et al.; Incubation of pig kidney cells (PK-cells) in the presence of 5-azacytidine (5-azaC), a DNA enzymatic methylation inhibitor, at concentration of 20 microM for 6 or 24 h results in a dramatic decrease in the DNA methylation level (5mC/C + m5.100) - from 3.0 in control to 1.0 in experiment . This is accompanied by a virtually complete arrest of mitosis and a decrease in the ratio of labeled interphase cells upon simultaneous introduction of 3H-deoxycytidine . The incubation with 5-azaC block PK-cells mainly in the G2-period . The inhibitory action is reversible, for the cells enter into mitosis after removal of the inhibitor . Metaphase chromosomes, whose DNA was replicated in the presence of the 5-azaC, exhibit certain ultrastructural differences from normal ones . The results are being discussed in connection with the earlier data on the anomalous structure of interphase chromatin formed in the course undermethylated DNA replication. Probl Endokrinol (Mosk), 1989 May-Jun, 35(3), 54 - 8 {Hormonal regulation of total RNA and protein biosynthesis in liver cell cultures of rats in the pre- and postnatal period of development}; Fedotov V et al.; The effects of several hormones on total RNA and protein biosynthesis were examined in primary cultures of liver cells obtained from rat fetuses on 21-22 days of gestation and from 3 week-old weanling rats . The intensity of biosynthesis processes was estimated by the incorporation of labeled precursors in macromolecules . Insulin, cortisol, triiodothyronine (T3) stimulated RNA and protein biosynthesis in both types of cultures . These hormones enhanced total protein biosynthesis in fetal rat liver cells more efficiently than in hepatocytes of weanling rats . Somatotropin (growth hormone--GH) did not change total protein biosynthesis but notably increased RNA synthesis and the production of immunoreactive serum albumin . Experiments on fetal rat liver cell cultures showed that stimulating action of cortisol on RNA synthesis was synergistic in relation to the effects of insulin and GH . It has been concluded that fetal rat liver cell at the end gestation are able to respond adequately to anabolic action of the hormones. FEBS Lett, 1989 Apr 24, 247(2), 349 - 52 Inhibition of HIV replication in cell culture by the specific aspartic protease inhibitor pepstatin A; von der Helm K et al.; After incubation of H9 cells infected with human immunodeficiency virus (HIV) with pepstatin A at 10(-4) M for 2, 4, or 11 days, the culture medium contained significantly less HIV core antigen (p24) than controls without pepstatin A and no or only borderline activity of reverse transcriptase was detected . In addition, after pepstatin A treatment no infectious HIV at 2 or 4 days and only minimal amounts at 11 days were detectable in the culture medium. Neurosci Lett, 1989 Apr 10, 98(3), 291 - 6 Quisqualate receptor-mediated rhythmic bursting of rat hypothalamic neurons in dissociated cell culture; Misgeld U et al.; Dissociated hypothalamic neurons from embryonic rat brain exhibit a level of spontaneous synaptic activity after 21 days in culture . When GABA-mediated responses are blocked by picrotoxin or bicuculline (20 microM), the neurons burst rhythmically . Rhythmic burst activity is generated in most cells by postsynaptic excitatory currents (EPSCs) through non-specific cationic channels rather than by intrinsic pacemaker currents . We present evidence that EPSCs are mediated by an excitatory amino acid and a quisqualate receptor type. J Neurochem, 1989 Apr, 52(4), 1253 - 9 Characterization of cellular transport, subcellular distribution, and secretion of the neurotoxicant 1-methyl-4-phenylpyridinium in bovine adrenomedullary cell cultures; Reinhard JF Jr et al.; Cultures of bovine adrenomedullary chromaffin cells accumulated 1-{methyl-3H}methyl-4-phenylpyridinium ({3H}MPP+) in a time- and concentration-dependent manner with an apparent Km of 0.7 microM and a Vmax of 3 pmol/min/10(6) cells . The uptake was sodium dependent and sensitive to inhibitors of the cell-surface catecholamine transporter . At low concentrations of MPP+, the subcellular distribution was identical to that of endogenous catecholamines in the catecholamine-containing chromaffin vesicles . However, at a higher concentration of MPP+, a larger proportion of the toxicant was recovered in the cytosolic fraction, with less in the chromaffin vesicle fractions . When cells were prelabeled with {3H}MPP+, at 1 and 300 microM, and then permeabilized with digitonin in the absence of Ca2+, there was a proportionally greater release of MPP+ from the cells labeled at the higher concentration of the toxicant . In the presence of Ca2+, cell permeabilization induced a time-dependent secretion of catecholamines and a parallel secretion of MPP+ . Under these conditions, the secretion of endogenous catecholamines was unaffected by the presence of MPP+ . When the permeabilization studies were carried out in the presence of tetrabenazine, a massive release of MPP+ was observed in the absence of Ca2+ and was not further increased by Ca2+ . In intact cells prelabeled with 300 microM {3H}MPP+, the secretagogues nicotine and veratridine elicited a Ca2+ -dependent secretion of catecholamines and MPP+ from the cells in similar proportions to their cellular contents . Barium-induced release of both species was independent of external Ca2+.(ABSTRACT TRUNCATED AT 250 WORDS) Hear Res, 1989 Apr, 38(3), 277 - 87 Establishment of inner ear epithelial cell culture: isolation, growth and characterization; Rarey KE et al.; Select epithelial regions of the bovine inner ear were established and maintained in cell culture . Marginal cells from the stria vascularis and dark cells from the posterior wall of the utricle were isolated, dissociated and placed in culture medium . Within 24 h, cellular islands of hexagonal-shaped, epithelial-like cells from both the stria vascularis and posterior utricular wall were readily identifiable by inverted light microscopy . Ultrastructural examination of both the cultured stria marginal cells and utricular dark cells revealed that both cell types had numerous microvilli on their apical surfaces and interdigitating infoldings of their basolateral surfaces . Apical tight junctional complexes were present between apposing cells . These findings demonstrate that inner ear bovine epithelial cells can be successfully isolated and maintained in culture, and that such cells retain certain of their in vivo morphological characteristics. Indian J Exp Biol, 1989 Apr, 27(4), 350 - 5 Immune response induced by Vero cell culture adapted buffalo pox virus in rabbits and buffaloes; Mohanty PK et al.; The Vero cell culture adapted buffalo pox virus was found to be completely attenuated at 40th passage for rabbits as well as buffaloes since it did not produce any thermal reaction or skin lesions . It induced high level of humoral and cell mediated immune response in rabbits as well as buffaloes . The antibody titres obtained were 80-160 for SN antibody, 32 for complement fixing and 640-1280 for enzyme immunoassay antibodies . The percent migration inhibition (MI) of leukocytes was 65.3% in rabbits and 69.50% in buffaloes, MI of macrophages was 62.15% in rabbits and 63.02% in buffaloes with a high skin reactive factor value . In protection tests conducted in rabbits and buffaloes, all the vaccinated animals were immune as compared to controls which showed severe disease. Clin Exp Immunol, 1989 Apr, 76(1), 126 - 31 Unresponsiveness to Con A in spleen cell cultures of M . lepraemurium-infected mice is dependent on a defective expression of high-affinity IL-2 receptors rather than on a lack of IL-2 production; Turcotte R et al.; The production of interleukin-2 (IL-2) by Con A-activated spleen cells (SC) progressively declined and reached negligible values during the course of infection of C57BL/6 mice with Mycobacterium lepraemurium . In addition, the capacity of cultured SC to utilize IL-2 was highly reduced, as demonstrated by the accumulation of IL-2 activity in culture supernatants at 48 and 72 h after Con A activation . The depressed IL-2 utilization started to be observed about 1 to 2 weeks prior to the onset of the depressed IL-2 production and was not reversed by the addition of exogenous IL-2; thus implying that a lack of IL-2 utilization rather than a lack of IL-2 production could be directly responsible for the inhibition of T-cell proliferative responses to Con A in SC cultures of infected mice . The utilization of IL-2 was found to be down-regulated, at least in part, by splenic suppressor cells since, in mixed-culture experiments, SC from infected mice actively depressed the capacity of normal splenocytes to consume IL-2 . Finally, the depressed IL-2 utilization would result from a 2- to 3-fold reduction of either or both the density of high-affinity IL-2 receptors and their affinity for IL-2. Gan To Kagaku Ryoho, 1989 Apr, 16(4 Pt 2-3), 1893 - 8 {A new high-yield continuous cell culture system and its clinical application in adoptive immunotherapy with LAK cells}; Noto T et al.; We developed a high-yield culture system, consisting of a culture bag on a rotator . The culture bag has two compartments, an inner compartment separated from an outer compartment by a semipermeable membrane . Cells in an appropriate culture medium are placed in the inner compartment, and medium without serum is placed in the outer compartment . The bag is rotated at an angle of 45 degrees between 0.5 and 5 rpm in a 37 degrees C incubator . The medium is changed in the outer compartment at intervals when needed . The outer compartment acts as the feeder as well as allows catabolites to diffuse through the culture . In addition, since the system is a closed-system, sterile conditions can easily be maintained . Using this system, we demonstrated that up to 20 X 10(6) cells/ml of PBMC could be cultured in IL-2 with sufficient recovery rate and cytotoxicity. Eur J Haematol, 1989 Apr, 42(4), 321 - 6 Endogenous megakaryocyte colonies from peripheral blood in precursor cell cultures of patients with myeloproliferative disorders; Battegay EJ et al.; Megakaryocyte colony formation, as identified by conventional techniques, was observed in precursor cell cultures from peripheral blood in 8 of 20 consecutive patients with diagnosis of myeloproliferative disease (4/11 patients with polycythemia vera, 3/5 with essential thrombocythemia, 1/2 with primary osteomyelofibrosis and 2 with a myeloproliferative syndrome not further assessable), but not in 50 healthy controls (p less than 0.0001) . 7 cultures showed spontaneous erythroid colonies, but were negative for megakaryocyte colonies . Megakaryocyte colony formation was independent of added erythropoietin, plasma or human leukocyte-conditioned medium, but was dependent on the presence of accessory cells . The cells in megakaryocyte colonies had the characteristic morphology of megakaryocytes and stained positively with the IIIa/IIb monoclonal anti-platelet antibody . Thus, megakaryocyte colony formation by precursor cells from peripheral blood in the absence of exogenous stimulating factors seems to be a phenomenon specific for myeloproliferative disease . Differential diagnosis of thrombocythemia may be facilitated by demonstration of endogenous megakaryocyte colony formation, which does not occur in secondary disease. Dtsch Tierarztl Wochenschr, 1989 Apr, 96(4), 213 - 5 {Reaggregating brain cell cultures: methodical aspects, morphological and biochemical characteristics, possible applications}; Hewicker M; A survey is given of the characteristics of the culture system of rotation-mediated reaggregating brain cell cultures . Aggregates of dissociated fetal brain cells of different species undergo morphological and biochemical differentiation in vitro, which resembles normal brain development in vivo . The usefulness of this system, e.g . for virological investigations in veterinary medical research is discussed. Dtsch Tierarztl Wochenschr, 1989 Apr, 96(4), 180 - 2 Morbillivirus in seals: isolation and some growth characteristics in cell cultures; Liess B et al.; The procedure used for the cultural isolation of morbillivirus from seals as well as some growth characteristics of isolates is described briefly . Emphasis was laid upon cytopathic changes typical for morbillivirus and observed in seal kidney cell culture subsequent to inoculation of organ tissue suspensions or buffy coat leucocytes . The modalities which resulted in the identification of 21 morbillivirus isolates from 16 seals by using direct fluorescent antibody (FA) or peroxidase linked antibody (PLA) techniques are outlined and illustrated. J Virol, 1989 Apr, 63(4), 1704 - 14 Effects of cell differentiation on replication of A/WS/33, WSN, and A/PR/8/34 influenza viruses in mouse brain cell cultures: biological and immunological characterization of products; Bradshaw GL et al.; The responses of mouse embryo brain (MEB) cell cultures and of Madin-Darby canine kidney cells and chicken embryo fibroblasts to infection with A/PR/8/34 (PR8), A/WS/33 (WS), or the neurovirulent WSN variant were compared in terms of (i) single-cycle yields of hemagglutinating and associated neuraminidase (NA) activities and plaque-forming particles, the latter with or without trypsin activation {PFU(TR++) or PFU(TR--), respectively}, and (ii) expression of nucleoprotein (NP), M1, and NS1 protein, determined for specific cell types by immunostaining, for whole culture lysates by Western blot analysis of NP and M1 . Primary MEB cultures grown in serum-enriched medium were infected after 6 days (young), when none of the cells reacted specifically and exclusively with any of the nerve cell marker antibodies used, or after greater than or equal to 21 days (aged), when astrocytes (the predominant cell type), neurons, and oligodendrocytes were morphologically and immunologically mature . Secondary astrocyte-enriched cultures were used when they contained 90 to 99% of their cells as astrocytes at an early stage of differentiation . By all criteria, young MEB cultures were only marginally less permissive for each of the three viruses than were chicken embryo fibroblasts or Madin-Darby canine kidney cells . Aged MEB cultures, by comparison, produced undiminished NP, hemagglutinin, and neuraminidase, but yields of PFU(TR++) and expression of M1 protein (relative to NP) were reduced for all three viruses, most for PR8 and least for WSN; relative reduction of NS1 protein was demonstrable only in PR8-infected aged cultures . Immunostaining revealed low levels of M1 and NS1 expression only in astrocytes, not in oligodendrocytes and neurons . In PR8-infected mature astrocytes, NP accumulated in the nucleus; it persisted in some cells for at least 8 weeks after infection . The presence of NP did not seem to interfere with cell division . Secondary MEB cultures containing 90 to 99% immature astrocytes were less restricted than were aged primary cultures . Thus, it appears that reduced permissivity of nerve cell cultures, as measured in this study, is most closely correlated with advancing differentiation and maturity of astroglial cells . Assembled virions, including those that score as PFU(TR++) in restricted cultures (e.g., PR8-infected aged MEB), may be mainly products of mature oligodendrocytes and neurons. Rev Saude Publica, 1989 Apr, 23(2), 162 - 9 {Biochemical characterization of calf sera used in the maintenance of cell cultures used in virology}; Tenorio EC et al.; Eight lots of the calf sera employed to supplement culture media for the cultivation of animal cells, of widespread use in virology obtained from calves above and below six months of age were rated as good or as poor cell growth promoters according to their growth promoting capacity (GPC) . Parameters related to macronutrients contained in these serum lots were then evaluated with the purpose of establishing their biochemical profiles . The results obtained can be considered as normal values for apparently healthy animal donors . Fluctuations found between the data of this investigation and those mentioned in the literature for certain biochemical parameters are probably due to the methodology employed, the breed and age of the animals, or even to regional diet . Student's "t" test was applied for the statistical analysis of the results and demonstrated that, as far as serum fractions were concerned, no significant differences occurred between sera rated as good and poor cell growth promoters, taking tc = 2.45 . For calf sera from animals above and below six months of age, two tests relating to alfa and beta fractions were significant (t = 2.68 and 2.61 respectively) . It was demonstrated that the evaluation of the biochemical parameters mentioned "per se" neither leads to the identification of calf sera presenting good or poor GPC, nor of sera harvested from calves younger or older than six months. J Neurochem, 1989 Apr, 52(4), 1300 - 10 Glutamate stimulation of {3H}dopamine release from dissociated cell cultures of rat ventral mesencephalon; Mount H et al.; In dissociated cell cultures of fetal rat ventral mesencephalon preloaded with {3H}dopamine, glutamate (10(-5)-10(-3) M) stimulated the release of {3H}dopamine . Glutamate stimulation of {3H}dopamine release was Ca2+ dependent and was blocked by the glutamate antagonist, cis-2,3-piperidine dicarboxylic acid . Glutamate stimulation of {3H}dopamine release was not due to glutamate neurotoxicity because (1) glutamate did not cause release of a cytosolic marker, lactate dehydrogenase, and (2) preincubation of cultures with glutamate did not impair subsequent ability of the cells to take up or release {3H}dopamine . Thus, these dissociated cell cultures appear to provide a good model system to characterize glutamate stimulation of dopamine release . Release of {3H}dopamine from these cultures was stimulated by veratridine, an activator of voltage-sensitive Na+ channels, and this stimulation was blocked by tetrodotoxin . However, glutamate-stimulated {3H}dopamine release was not blocked by tetrodotoxin or Zn2+ . Substitution of NaCl in the extracellular medium by sucrose, LiCl, or Na2SO4 had no effect on glutamate stimulation of {3H}dopamine release; however, release was inhibited when NaCl was replaced by choline chloride or N-methyl-D-glucamine HCl . Glutamate-stimulated {3H}-dopamine release was well maintained (60-82% of control) in the presence of Co2+, which blocks Ca2+ action potentials, and was unaffected by the local anesthetic, lidocaine . These results are discussed in terms of the receptor and ionic mechanisms involved in the stimulation of dopamine release by excitatory amino acids. Biokhimiia, 1989 Apr, 54(4), 694 - 701 {Estimation of a direct regulatory effect of estrogens on hepatocytes, evaluated according to the change in the level of free estrogen-binding protein in primary cell culture}; Vishniakova TG et al.; Male rat hepatocyte cultures have been obtained . The culturing hepatocytes had a stable level of some morphological and functional properties . A high level of estrogen receptors (ER) and E2-sensitive unusual estrogen-binding protein (UEBP) was found . A direct dose-dependent inhibiting effect of physiological (10(-10)-10(-7) M) concentrations of E2 on UEBP content was established in cell cultures incubated with the hormone for 3 days . Hexestrol (but not cholesterol) was found to exert a direct inhibiting effect . The inhibiting effect of E2 (10(-9) M) was observed after a 24 hour incubation of hepatocytes with the hormone but was less pronounced . In this case a significant increase in UEBP concentration in hepatocytes was noted 72 hours after the removal of E2 . It is concluded that physiological concentrations of E2 can exert a direct regulatory influence on certain functions of culturing hepatocytes acting via hepatocyte ER. Virus Res, 1989 Apr, 12(4), 383 - 92 Flaviviruses can mediate fusion from without in Aedes albopictus mosquito cell cultures; Summers PL et al.; Flavivirus-induced polykaryocytes were detected in monolayers of Aedes albopictus (clone C6/36) mosquito cells as early as 20 min after adsorbing virus to these cells . A high multiplicity of infection with dengue (DEN)-1, 2, 3, 4, Japanese encephalitis, and yellow fever viruses was required to demonstrate fusion from without (FFWO) with these flaviviruses . Optimal conditions for FFWO included exposure of adsorbed virus to pH 6.0 and an incubation temperature of 39 degrees C . DEN-2 monoclonal antibodies to the envelope E glycoprotein inhibited cell fusion, whereas monoclonal antibodies to the prM and NS1 proteins did not inhibit cell fusion . These results indicate that flaviviruses cause FFWO soon after adsorption to C6/36 mosquito cells and the process is most likely mediated by the virion envelope E glycoprotein. Biotechnol Appl Biochem, 1989 Apr, 11(2), 209 - 16 Free gp70 from FeLV: enrichment from cell culture fluid by ferric oxide-agarose chromatography; Zelikman I et al.; A new chromatographic material based on beads of macroporous crosslinked agarose containing ferric oxide particles was used for enrichment of gp70--the envelope glycoprotein of feline leukemia virus (FeLV) . Free gp70 was purified from cell culture fluid in one step with a recovery of 50 to 60% and a purification of about 60 times . The described procedure is a suitable first step for the purification of gp70 from large volumes of cell culture fluid. J Virol, 1989 Apr, 63(4), 1839 - 43 A conserved open reading frame that overlaps the herpes simplex virus thymidine kinase gene is important for viral growth in cell culture; Jacobson JG et al.; Of 18 mutants containing clustered point mutations within UL24 (an open reading frame that overlaps the herpes simplex virus thymidine kinase gene on the opposite strand), 15 formed small plaques and were substantially impaired for virus growth in cell culture . Mutations conferring the small plaque phenotype disrupt regions of UL24 that share considerable sequence similarity with open reading frames common to herpesviruses of mammals and birds . We infer that UL24 is expressed and important for virus growth in cell culture and suggest that possible effects on UL24 should be considered in studies of thymidine kinase-deficient mutants. Proc Soc Exp Biol Med, 1989 Apr, 190(4), 320 - 3 Ether as an anesthetic for decapitation in the rat: gonadotropin secretion by subsequently established anterior pituitary cell cultures; O'Conner JL et al.; Historically, for the establishment of dispersed anterior pituitary cell cultures, rodents have been killed by decapitation without anesthesia . Because decapitation fails to induce immediate unconsciousness, the American Veterinary Medical Association Panel on Euthanasia has recently recommended that rodents should not be decapitated without previous anesthesia or sedation . Investigators are therefore confronted with the dilemma of wishing to euthanize rodents humanely yet not wishing to potentially compromise experimental data through the use of anesthetics . We present our observations on the effects of diethyl ether anesthesia administered prior to decapitation on the gonadotropin secretory characteristics exhibited in vitro by cultured rat anterior pituitary cells . Neither light nor complete (surgical level) ether anesthesia had any statistically significant effect on either luteinizing hormone or follicle-stimulating hormone responsiveness or cell content of luteinizing hormone and follicle-stimulating hormone or DNA content . The data indicate that ether anesthesia would appear to be acceptable for those studies involving subsequent in vitro luteinizing hormone and follicle-stimulating hormone secretion. Agents Actions, 1989 Apr, 27(1-2), 46 - 8 Histamine-releasing activity of mouse spleen cell culture supernatants; Wyczolkowska J et al.; Histamine releasing factor (HRF) generated in vitro by spleen cells of immunized mice activates homologous peritoneal mast cells (both normal and sensitized) for small but consistent, dose-dependent histamine and 5-hydroxytryptamine release . Both the time-course of this release and its susceptibility to the enhancing effect of D2O were similar to those observed in IgE-induced release; however, simultaneous challenge of sensitized mast cells with HRF and specific antigen or anti-IgE showed an additive effect, suggesting that mediator release by HRF and by the IgE system are independent of one another. Br J Pharmacol, 1989 Apr, 96(4), 940 - 8 Caesium ions: a glycine-activated channel agonist in rat spinal cord neurones grown in cell culture; Smith SM et al.; 1 . The chloride (Cl-) currents activated by caesium ions (Cs+), glycine and gamma-aminobutyric acid (GABA) were compared following their application to rat neurones that had been grown in cell culture . Recordings