J Hyg Epidemiol Microbiol Immunol, 1978, 22(3), 375 - 81 {Demonstration of the oncogenic activity of cell cultures using antithymocytic serum}; Abel C et al.; The authors examined 10 cell strains of different origin as to their effect on mice by means of antithymocytic (ATC) serum . In dependence on the strain used the tumors developed in different number and with different growth tendency . In control animals not treated by the ATC serum, small ganglions developed in some cases which, however, disappeared in 2--3 days . Both strains of diploide cells WI 38 and LEP and primary cultures of chicken fibroblast from embryos of SPF chickens did not develop any tumors . The antithymocytic serums from calfs were found to be less toxic for mice than the rabbit sera. Folia Biol (Praha), 1978, 24(1), 68 - 77 A contribution to the technique of mouse bone marrow cell culture in semisolid agar; Ponka P et al.; A method of cultivation of mouse bone marrow cells in semisolid agar is described . Colony-stimulating factor was provided either by a "feeder layer" containing kidney cells (from 8-day-old mice) or by the addition of "lung conditioned medium" or post-endotoxin serum . The effect of various factors and media on the formation of colonies was tested . The best growth of colonies was observed in medium RPMI 1640 or in Eagle's minimal essential medium containing 0.2% bactotryptose supplemented with 20% foetal calf serum . Both the morphology of cells found in the colonies and the proliferative state of the cells that give rise to colonies indicate that CFU-C represent the committed progenitor for myelopoiesis. Arch Toxicol Suppl, 1978, (1), 319 - 22 Toxicology of triethyllead, methylmercury and cadmium, determined in chick embryo brain cell cultures; Ammitzboll T et al.; The toxicology of water soluble chemical compounds may be investigated in tissue culture systems . The toxicology of triethyllead chloride, methylmercury chloride and cadmium acetate was studied in chick embryo brain cell cutlures . Tetraethyllead is added to petrol as an anti-knock agent . When tetraethyllead is absorbed by the organism, it is converted to triethyllead which cause the symptoms of tetraethyllead poisoning . Chick embryo brain cell cultures derived from cerebrum of 11-day-old chick embryos developed both neurons and glial cells . The neurons formed nerve processes and synapsis in the cultures . The effect of triethyllead chloride was investigated by addition of triethyllead chloride to the nutrient medium . The median tissue culture lethal dose, TCLD50 = 1.9 mg/l, was determined as the concentration of triethyllead chloride at which the confluent layer of glial cells was destroyed in 50% of the cultures . The neurons lost their processes at even lower concentration, TCED50 = 0.57 mg/l . Electron microscopy revealed cells with swollen Golgi apparatus and dilated endoplasmic reticulum in chick embryo brain cell cultures which were treated with triethyllead chloride, 1.0 mg/l . Studies with radioactive labelled precursors revealed that triethyllead chloride inhibited the synthesis of DNA, sulfatides and cerebrosides without hydroxyfatty acids. Dtsch Zahnarztl Z, 1978 Jan, 33(1), 29 - 32 {Cell culture of human gingival epithelium}; Heidemann D et al.; Gingival explants were taken from 8 volunteers in order to find a method to grow gingival epithelial cells . We succeeded in what we regarded as optimal conditions in achieving a monolayer cell thickness in the culture by means of BHK medium and foetal calf serum. Arch Inst Pasteur Alger, 1978-79, 53, 262 - 73 {Modification of the strain Flury HEP after its adaptation to cell culture . Development of experimental vaccine for veterinary use}; Benmansour A; The rabies strain Flury HEP, adapted in our laboratory to BHK21 cells, shows, after 20 passages on this cell, an important modification of its pathogenic characteristics on adult mice, guinea pigs and hamsters . An experimental vaccine made with this adapted strain gives a good sero-conversion rate when injected by the intramuscular route to a group of dogs. Ann Rech Vet, 1978, 9(4), 729 - 34 An infectivity assay for the bovine leukemia virus based on the induction of the major internal virion antigen in susceptible cell cultures; Jerabek L et al.; This report described the development of a 7-day infectivity assay for the bovine leukemia virus (BLV) which is based on the induction of the major internal virion antigen (p25) in susceptible indicator monolayer cell cultures . In this assay the antigen is detected in the indicator cells by the immunoperoxidase antibody technique using a monospecific anti-BLV serum . The immunoperoxidase infectivity assay (IPIA) is specific, quantitative, reproducible and more sensitive than the previously developed syncytia induction assay . The IPIA can be applied for the detection of BLV-infected cells and provides a reliable method for the direct diagnosis of BLV infection in cattle. Ann Rech Vet, 1978, 9(4), 609 - 12 Studies on specific antigen content in different fractions of preparations from BLV-producing cell cultures; Grundboeck-Jusko J et al.; Different protein fractions of BLV-antigens were examined with serological and chemical methods . The fractions of ether resistant and dual antigens were obtained by means of QAE-50A Sephadex chromatography and the fractions of gp-antigen were collected in the course of the affinity chromatography on Concanavalin A-Sepharose . All protein fractions examined by means of polyacrylamide gels electrophoresis occurred to be heterogenous . Some of them showed positive RID or GID reactions with sera of cattle or sheep affected with leukosis . By means of thinlayer chromatography on Sephadex, there were estimated following molecular weights of proteins in the serologically positive fractions: 12.500, 67.000, 70.000 and 150.000. Arch Virol, 1978, 58(3), 193 - 202 Synthesis of coreless, probably defective virus particles in cell cultures infected with rotaviruses; McNulty MS et al.; PK-15 cells infected with pig and lamb rotavirus strains which were not adapted to serial growth in cell cultures were examined by electron microscopy . A major difference between virus morphogenesis in the initial passage in PK-15 cells and in intestinal epithelial cells was the generation of large numbers of coreless virus particles in PK-15 cells . The numbers of coreless particles increased with increasing multiplicity of infection . Infectious virus was synthesized in PK-15 cells, but a variable decrease in infectivity titre occurred between 12 and 24 hours after infection . It is suggested that synthesis of defective interfering particles or an inhibitory substance such as interferon might account for this decrease. Adv Exp Med Biol, 1978, 110, 37 - 53 Production of interferon in human cell cultures by a new, potent viral inducer; Jameson P et al.; A new discovered double-stranded RNA inducer of interferon, bluetongue virus (BTV), stimulates the production of large amounts of interferon in animals as well as in many types of mammalian cell cultures, including human leukocytes, and continuous cell lines . The exceptional pH lability of BTV and its lack of pathogenicity for man further recommend its use as an interferon inducer . Among several human cell lines tested, the most efficient producer of interferon was a continuous cell line designated HT-1376, derived from a bladder carcinoma . With infectious BTV as the inducer, the HT-1376 line produced more interferon per cell than did leukocytes; interferon yields ranged from 10,000 to 60,000 units per ml of crude, unconcentrated supernatant fluid . Noninfectious BTV, inactivated by ultraviolet irradiation, was as effective as infectious virions . The interferon produced in HT-1376 cells has physicochemical and antigenic properties resembling those of fibroblast interferon produced in diploid cells. J Med Virol, 1978, 2(2), 127 - 36 Enhanced parainfluenza I (6/94) virus detection in latently infected human brain cell cultures by treatment with cytochalasin D and dimethyl sulfoxide; Wroblewska Z et al.; The ability of cytochalasin D (CD) and dimethyl sulfoxide (DMSO) to enhance parainfluenza I (6/94) virus replication was studied in various cell culture systems . Treatment of CV1 cells with CD (1 microgram/ml) dissolved in DMSO prior to primary 6/94 virus exposure at 10(0)--10(5) multiplicities of infection did not substantially enhance virus replication . However, there was a transient increase in cell associated virus one day after infection of DMSO-treated cultures . CD treatment of cultures of human brain cells latently infected with 6/94 virus (LIHB cells) did not enhance 6/94 virus detection . Cocultivation of CV1 cells with CD-treated LIHB cell cultures, and cocultivation of LIHB cell cultures with CD-treated CV1 cells, resulted in the production of both cell-associated and cell-free 6/94 virus three and five days after cocultivation . No virus was detected after similar cocultivation of untreated LIHB cell cultures with untreated CV1 cells . The usefulness of CD-DMSO treatment in the rescue of virus from 6/94 LIHB cell cultures appears limited to a cocultivation system . The use of these techniques to enhance virus rescue from human tissues suspected of harboring latent viral genomes is discussed. Intervirology, 1978, 10(2), 115 - 9 Association of cytomegalovirus (CMV) infection with cervical cancer: isolation of CMV from cell cultures derived from cervical biopsy; Melnick JL et al.; Cytomegalovirus (CMV) was isolated from cell cultures derived from 2 of 10 cervical cancer biopsies from patients in an advanced stage of the disease . Five serial passages were necessary before extensive cytopathic changes characteristic of CMV infection appeared . All patients tested had complement-fixing antibodies to both isolates in higher titers than to the prototype AD169 strain . 6 of 8 patients tested also had herpesvirus type 2 antibodies. Avian Dis, 1978 Jan-Mar, 22(1), 170 - 6 An improved method for extracting cell-free herpesviruses of Marek's disease and turkeys from infected cell cultures; Cho BR; Sonic extraction of cell-free Marek's disease herpesvirus (MDHV) and turkey herpesvirus (HVT) from infected cell cultures was improved by incorporating sorbitol in the suspending media . Yields of cell-free virus of virulent MDHV were significantly increased with 10% sorbitol added to SPGA-EDTA buffer . Avirulent strains of MDHV and HVT were respectively readily extracted with SPGA-EDTA and SPGA as the suspending medium, and extraction of their cell-free viruses was moderately improved by adding sorbitol to the suspending medium. Vopr Virusol, 1978 Jan-Feb, (1), 118 - 20 {Use of collalytine for preparation of monolayer primary cell cultures}; Babikova RA; Collalytine, a national preparation of collagenase effect, may be used for dispersion of different organs of cattle and human fetuses . Depending on the concentration and time of treatment, this preparation permits to produce monolayer cultures of histotypic or cytotypic nature. J Natl Cancer Inst, 1978 Jan, 60(1), 213 - 7 Isolation of a precipitating glycoprotein antigen from cell cultures persistently infected with bovine leukemia virus; Phillips M et al.; A procedure was developed to isolate a glycoprotein with precipitating antigen activity from fluids from fetal lamb kidney cell cultures persistently infected with bovine leukemia virus (BLV) . The antigen was precipitated by ammonium sulfate and subjected to affinity chromatography on concanavalin A Sepharose . The glycoprotein was eluted with alpha-methyl-D-mannoside and was further purified by gel filtration over Sephadex G-100 . Antigen activity was determined by agar gel immunodiffusion (AGID) reactions with serum from cattle infected with the virus . The major portion of the AGID activity was eluted from the Sephadex G-100 in the 60,000-dalton elution region . In some experiments, identical AGID activity was also found in the 18,000-dalton elution region . The larger protein was discovered to have a molecular weight of 58,000 daltons by sodium dodecyl sulfate-polyacrylamide gel electrophoresis . Its designation as a glycoprotein was confirmed by carbohydrate-positive staining . The isolated BLV glycoprotein antigen did not contain ovine or bovine proteins as indicated by gel immunodiffusion. Intervirology, 1978, 9(1), 56 - 9 A simple method for concentration of enteroviruses and rotaviruses from cell culture harvests using membrane filters; Farrah SR et al.; Organic compounds in cell culture harvests known as membrane-coating components (MCC) prevent virus adsorption to membrane filters . Blending cell culture harvests with fluorocarbon removed the MCC and permitted adsorption of virus in acidified harvests to epoxy-fiberglass filters . Subsequent elution with high pH buffer resulted in recovery of greater than 90% of the virus with concentrations of up to 100-fold. C R Seances Soc Biol Fil, 1978, 172(3), 459 - 64 {Enhancement of growth of rat liver cell cultures by lithocholic acid}; Jeannin JF et al.; Lithocholic acid enhances the growth of 4 independent lines of liver cells, but is toxic to colon cancer cells and fibroblasts in culture . Cholic acid does not affect the growth of liver cells, deoxycholic and chenodexoycholic acids are highly toxic to them. Acta Med Iran, 1978, 21(2), 129 - 40 {Comparative sensitivity of 4 different cell cultures in the isolation and identification of mumps virus}; Kiai FM; Three different continuous cell lines (Am 57, Hela, Vero) and primary cell culture of human embryo kidney are compared with regard to their susceptibility for isolation of mumps virus from saliva and cerebrospinal fluid . For this purpose the Vero cell line appeared to be more suitable among the studied cell systems regarding the following reasons: it allows the highest percentage of mumps virus isolation . The cytopathic effect caused by mumps virus occurs comparatively rapidly in this cell culture . This cytopathic effect is typical enough to allow for a preliminary diagnosis of mumps virus. Anim Blood Groups Biochem Genet, 1978, 9(3), 175 - 9 Isozyme characterization of cattle (Bos taurus) and American buffalo (Bison bison) cell cultures; Carleer J et al.; Four Bovidae cell lines (BEK-1, MDBK, Bu and EBTr) were characterized by means of enzymatic biochemical markers . Out of 15 enzymatic systems, 3--adenosine deaminase (Ada), phosphoglucomutase (Pgm) and nucleoside phosphorylase (Np)--were found to be polymorphic and quite suitable for biochemical identification of each cell line . The Bu cell line has shown a Np phenotypic pattern which could be distinctive of the Bison bison species. Dev Biol Stand, 1978, 40, 147 - 53 Pre-immunization and post-exposure treatment with inactivated rabies vaccine of chick embryo cell culture origin (CEC); Kondo A; Routine laboratory assay revealed that the potency of concentrated rabies vaccine of chick embryo cell culture (CEC) origin was in the same level compared with suckling mouse brain (SMB) vaccine . Over one hundred persons received two doses of CEC vaccine at an interval of one week and produced high level of neutralizing antibody against rabies virus . The monkeys experimentally infected with street rabies virus were satisfactorily protected by subcutaneous inoculation with CEC vaccine one hour after exposure . Eight persons bitten by dogs known to have rabies or suspected of it, survived after post-exposure treatment with CEC vaccine. Arch Toxicol Suppl, 1978, (1), 277 - 9 Induction of arylhydrocarbon hydroxylase and UDP glucuronosyl transferase by PCB in hepatic cell cultures; Ahotupa M et al.; The purpose of the investigation was to derive a hepatic cell line to be used in induction studies of drug metabolizing enzymes . Two pure cell lines were isolated from primary liver cell cultures, one with an epithelial-like appearance, the other with a fibroblast-like appearance . The specific activities of arylhydrocarbon hydroxylase (AHH) and UDP glucuronosyl transferase (UDPGT) were greater in hepatocyte cultures than in primary cultures or in fibroblast cultures . PCB enhanced the activity of AHH and UDPGT in hepatocyte cultures . These results indicate that cultured hepatocytes can be used to study the effect of PCB on drug metabolizing enzymes. Cytobios, 1978, 23(91-92), 149 - 67 The differentiation and calcification of chondrocytes in primary cell cultures; Lewis NJ et al.; The cartilage from a non-immobilized fracture undergoes a series of morphological and biochemical changes resembling the in vivo differentiation and calcification in the epiphyseal plate . The studies reported here demonstrate that a homogeneous population of chondrocytes isolated from fracture callus fibrocartilage undergoes the same changes in vitro . Chondrocyte primary cultures were grown for 28 days during which time the morphological, histological and histochemical properties of the cultures were studied . Demonstrated by various histological procedures, chondrocytes synthesized the characteristic cartilage matrix, and progressively calcified with increased culture age . This system can be used to elucidate the cellular and molecular mechanisms of calcification. Cytogenet Cell Genet, 1978, 21(1-2), 86 - 98 Induced Robertsonian fusions and tandem translocations in mammalian cell cultures; Hsu TC et al.; Cultures of a cattle cell line and a Peromyscus eremicus cell line recovering from a pulse-treatment with mitomycin C, actinomycin D, 33258 Hoechst, and nitrosoguanidine exhibited translocations between chromosomes at the centromeric regions (Robertsonian fusions) as well as between centromere and telomere and between telomeres (tandem translocations) . The frequency of Robertsonian fusions was found to be dose-dependent and duration-dependent with the mitomycin treatment . Biarmed chromosomes resulting from fusions may be monocentric or dicentric . Analyses of clones isolated from treated cells suggested that fused chromosomes may perpetuate in the cell populations. Acta Derm Venereol, 1978, 58(1), 1 - 7 Studies on guinea pig skin cell cultures . VII . Statistical analysis of growth and maturation; Delescluse C et al.; Thymidine uptake; incorporation of amino acids into perchloric acid extract and HCl extract (corresponding grossly to poorly and highly organized proteins respectively); cell fraction DNA and cell fraction protein contents have all been measured daily from day 1 to day 8 in primary cultures of epidermal keratinocytes (EK) and dermal fibroblasts (DF) . Correlations between these five biochemical parameters (or variables) have been sought when using the statistical method of principal component analysis . The analysis of whole data of EK and DF populations taken together revealed that DNA content is a major distinguishing factor between these two cell types . The analysis of variables of each cell type taken independently showed that DF are essentially characterizable by their tendency to synthesize both poorly and highly organized proteins, whereas EK are more prone to DNA and highly organized protein synthesis . Thus, EK and DF in culture can be readily distinguished statistically by analysing their growth and maturation characteristics . It is even likely that time study of thymidine and amino acid incorporation would suffice to characterize these two cell types in vitro. Med Microbiol Immunol (Berl), 1978, 164(4), 267 - 75 The susceptibility of Vero cell cultures for human adenoviruses; Hasler P et al.; Human adenoviruses 1 to 28 were shown to produce a cytopathic effect in Vero cell cultures . Viruses of subgroups III and IV (Ad 1, 2, 5, 6, 12, and 18) were readily passaged in Vero cell cultures and were produced in high amounts . This was also found for Ad 11, 16, and 21, while Ad 3, 4, and 7 showed a lower degree of multiplication and Ad 14 could not be passed serially . For Ad 8, 26, 27, 20, 25, and 28, a multiplication in Vero cells could not be proved, while the remaining serotypes of subgroup II showed a moderate degree of multiplication . The sensitivity of Vero cells to small amounts of virus was lower than that of HeLa cells . No adaption of adenoviruses to Vero cells after 5 Vero passages was observed . Attempts to enhance virus multiplication by coinfection with SV40 failed. Microbiol Immunol, 1978, 22(7), 377 - 90 Physico-chemical properties of mouse hepatitis virus (MHV-2) grown on DBT cell culture; Hirano N et al.; Some properties of a strain of mouse hepatitis virus, MHV-2, grown on DBT cells were determined using a plaque assay on the cells . Viral growth was not inhibited by the presence of actinomycin D or 5-iodo-2-deoxyuridine . MHV-2 was completely inactivated by ether, chloroform, sodium deoxycholate or beta-propiolactone, but showed a moderate resistance to trypsin . Heating at 56 C for 30 min did not completely abolish the virus infectivity . The virus was stable after heating at 50 C for 15 min in 1M-MgCl2 or 1M-MgSO4 as well as at 37 C for 60 min at pH 3.0 to 9.0 . Infectivity was decreased to 1/100 and 1/400 after storing at 4 C for 30 days and 37 C for 24 hr, respectively . The virus passed through a 200-nm but not a 50-nm Sartorius membrane filter . The buoyant density of MHV-2 was 1.183 g/cm3 in sucrose gradient, and the fraction contained coronavirus-like particles measuring 70 to 130 nm in diameter . Survival rate was 10% after exposure to ultraviolet at 150 ergs/mm2 . Freezing and thawing or sonication at 20 kc for 3 min did not affect the virus titer . No hemagglutinin was demonstrable with red blood cells of the chicken, Japanese quail, mouse, rat, hamster, guinea pig, sheep, bovine or human. Cancer Res, 1977 Dec, 37(12), 4523 - 8 Relationship between effects on nucleic acid synthesis in cell cultures and cytotoxicity of 4-demethoxy derivatives of daunorubicin and adriamycin; Supino R et al.; Four new derivatives of daunorubicin and two new derivatives of Adriamycin characterized by the absence of the methoxyl groups at the C-4 position have been studied in cell cultures in vitro to establish structure-activity relationships . 4-Demethoxydaunorubicin was 27 to 100 times more active than was daunorubicin when inhibiting the cloning efficiency of exponential-phase HeLa cells and, like daunorubicin, was slightly active on early plateau-phase cells . DNA synthesis in mouse embryo fibroblasts stimulated by fetal calf serum was inhibited equally by the two compounds, although 4-Demethoxydaunorubicin was slightly more active than was daunorubicin when inhibiting RNA synthesis . The beta anomer of 4-demethoxydaunorubicin showed a reduced activity on HeLa cells compared to its alpha anomer, but it was equally active on DNA synthesis . The stereoisomers of 4-demethoxydaunorubicin bearing the inverted configuration in positions 7 and 9 were devoid of significant cytotoxic activity and were only slightly active on DNA synthesis at the doses tested . 4-demethoxyadriamycin and 4-demethoxy-4'-epi-adriamycin were 65 to 500 times more active than was Adriamycin on HeLa cell cloning efficiency and about 10 times more active on DNA synthesis in mouse embryo fibroblasts . Cell uptake in mouse embryo fibroblasts was also investigated for all the new derivatives tested. J Clin Microbiol, 1977 Dec, 6(6), 618 - 26 La Crosse virus soluble cell culture antigen; Lindsey HS et al.; A virus-free soluble antigen, obtained by ammonium sulfate precipitation of the supernatant fluids of La Crosse virus-infected BHK-21 cell cultures, was more reactive and more specific than infected suckling mouse brain antigen when compared by immunodiffusion and counterelectrophoresis tests . By complement fixation tests, the antigen was cross-reactive with heterologous California group arbovirus hyperimmune mouse ascitic fluids, but to a lesser degree than was the standard sucrose-acetone-extracted infected suckling mouse brain antigen . The major virion nucleocapsid protein of La Crosse virus was found by polyacrylamide gel electrophoresis to be the soluble antigen protein responsible for precipitation in immunodiffusion and counterelectrophoresis tests. J Immunol, 1977 Dec, 119(6), 1933 - 7 Generation of T helper cells in vitro . III . Helper cell culture-derived factors are related to alloantigens coded for the I region of the H-2 major histocompatibility complex; McDougal JS et al.; Thymocyte-macrophage cultures primed with carrier protein release an alloantigen-related factor that enhances the anti-hapten plaque-forming cell response of hapten-primed spleen cells in vitro . Use of immunoadsorbant columns made with a variety of alloantisera indicates that the relevant antigens in this system are coded for the the H-2 major histocompatibility locus in mice . The data indicate that in H-2d and H-2k strains the important genetic regions are in the I region between the K region and the I-C subregion and suggest, based on current understanding of Ia specificities, that the I-A subregion codes for these antigens. J Virol, 1977 Dec, 24(3), 875 - 82 Properties of influenza C virus grown in cell culture; O'Callaghan RJ et al.; Influenza C virus was propagated successfully in primary chicken embryo lung (CEL) and fibroblast cells and in Madin-Darby canine kidney (MDCK) cells . In other cell lines, either no virus or only noninfectious hemagglutinin (HA) was produced . In productively infected cells (CEL), HA and infectious virus appeared by 24 h and reached a maximum by 36 to 48 h, cell-associated virus remaining at a constant low level . Infected Vero cells produced noninfective HA by 24 h which also remained predominantly cell associated until 60 to 72 h, when the cells disintegrated . Viral antigen was demonstrable on membranes of both CEL- and Vero-infected cells at 24 h; Vero cells yielded membrane vesicles containing HA, but none of the spherical or filamentous viral particles synthesized in CEL cells . Influenza C virus produced in cell culture or in eggs differed in several important respects from A and B viruses and from Newcastle diseases virus . All influenza C preparations, regardless of infectivity or source, lacked detectable neuraminidase activity, yet retained the ability specifically to inactivate receptors only for influenza C . Influenza C HA was not inhibited by soluble glycoproteins highly active against HA of A virus . A rat serum glycoprotein uniquely inhibited influenza C by binding to the surface components of virious. Res Commun Chem Pathol Pharmacol, 1977 Nov, 18(3), 507 - 17 Stimulation of phospholipase activity and prostaglandin biosynthesis by melittin in cell culture and in vivo; Hassid A et al.; Melittin, a membrane-active peptide of bee venom, as well as synthetic melittin, stimulated the biosynthesis of prostaglandins by mouse transformed fibroblasts (MC5-5), human fibroblasts (D550), rabbit aorta endothelial cells (CLO), rat lung type II alveolar pneumocytes (L-2) and rabbit smooth muscle cells (R-I) . The melittin peptides also stimulated the release of arachidonic acid from the cellular phospholipids of MC5-5 cells . The stimulated prostaglandin biosynthesis by MC5-5 cells was inhibited by indomethacin and dexamethasone . Dexamethasone inhibited also the release of arachidonic acid by MC5-5 cells . In mice, intraperitoneal inoculation of melittin increased 13,14-dihydro-15-keto-PGE2 levels in peripheral blood . Prior injections of the mice with indomethacin prevented the melittin-induced increase in this PGE2 metabolite. Cancer Res, 1977 Nov, 37(11), 3895 - 900 Ornithine decarboxylase induction and DNA synthesis in hamster embryo cell cultures treated with tumor-promoting phorbol diesters; O'Brien TG et al.; The effects of tumor-promoting phorbol diesters on ornithine decarboxyalse (ODC) activity and DNA synthesis in normal and chemically transformed hamster embryo fibroblasts (HEF) in culture were studied . Only those phorbol diesters with promoting activity in mouse skin induced ODC in HEF . ODC was induced in both cell types by 12-O-tetradecanoyl-phorbol-13-acetate (TPA); maximal induction occurred 4 to 6 hr after the addition of the promoter to the medium of confluent cultures and was greater in transformed cells than in normal cells . The extent of induction in transformed cells treated with 0.016 to 1.6 micron TPA was dose dependent . The cellular concentrations of the polyamines, particularly putrescine, also increased after TPA treatment . The addition of TPA to confluent cultures of either normal or transformed HEF did not produce an increase in cell number or the percentage of {3H}thymidine- labeled nuclei and did not stimulate the incorporation of {3H}thymidine . ODC also was induced by adding fresh medium to the cultures . When both fresh medium and TPA were added, the effect of the medium was markedly potentiated in transformed, but not in normal, cells . These experiments demonstrate that tumor promoters specifically induce ODC in HEF without increasing the rate of DNA synthesis and that normal and transformed HEF differ in the levels of ODC activity attained after exposure to promoters. Microbiol Immunol, 1977 Nov, 21(11), 639 - 47 The effect of the DNA-suppressing factor (DSF) on host DNA synthesis in synchronized cell cultures; Minagawa T et al.; Purified host DNA-suppressing factor (DSF) produced into culture fluid of HeLa C-9 cells infected with measles virus inhibited cellular DNA synthesis in HeLa cells . When purified DSF was added into cultures of synchronous HeLa cells at the early G1-phase, cellular DNA synthesis was irreversibly inhibited . However, DSF did not affect the stability of native double-stranded DNA nor the chain-elongation of single-stranded DNA in cells of the S-phase. Exp Hematol, 1977 Nov, 5(6), 546 - 50 Oxymetholone and erythropoiesis: failure to detect an effect in fetal mouse liver cell cultures; Dunn CD et al.; Oxymetholone, a steroid of proven clinical value in the treatment of refractory anemia, was without effect on endogenous or erythropoietin-mediated heme synthesis in fetal mouse liver cell cultures . This conclusion applied both when the cells were exposed to oxymetholone prior to culturing with erythropoietin and when the steroid was present in the cultures simultaneously with erythropoietin . Unlike those steroids having a direct effect on erythroid cells, oxymetholone also failed to increase the proportion of erythropoietin responsive cells in DNA synthesis . The relevance of these observations to the therapeutic benefit of oxymetholone is discussed . While the possibility that oxymetholone has to be metabolized to an active form cannot be excluded, the results suggest that oxymetholone does not seem to be erythropoietically active by a direct effect on erythroid cells . The fact that it is a successful therapeutic agent in some patients with aplastic anemia may be due to its proven ability to increase endogenous erythropoietin levels or to reduce ineffective erythropoiesis. Ann Microbiol (Paris), 1977 Nov-Dec, 128B(4), 541 - 5 {Long-term infection of a cell culture from newborn mouse brain with the FNV strain of yellow fever virus (author's transl)}; Fleury H et al.; A cell culture from brains of one day old mice was infected with a high multiplicity of the French neurotropic strain of yellow fever virus (FNV); the infected cell culture produced and released infectious FNV for more than 180 days post-inoculation with titres between 10(0.6) and 10(6.4) PFU/ml . The cell sheet exhibited some rare plaques of round cells with a slow centrifugal extension; the destruction of the cell sheet was not complete before 200 days post-inoculation. Endocrinology, 1977 Nov, 101(5), 1455 - 60 Estrogen action in vitro: regulation of thyroid stimulating and other pituitary hormones in cell cultures; Miller WL et al.; Primary cell cultures of ovine pituitaries can maintain production of thyroid stimulating hormone (TSH) for as long as 24 days . These cultures responded in a normal fashion to thyroxine by decreasing TSH secretion . Addition of thyrotropin releasing hormone increased TSH secretion . Physiologic levels of estradiol-17 beta (10(-11)-10(-9)M) produced a five-fold increase in secretion of TSH and a two-fold increase in intracellular TSH concentration in cell cultures . Common estrogens, but not common progestins, androgens and glucocorticoids affected TSH production . Markedly different effects of estrogen in the pituitary on follicle stimulating, luteinizing and thyroid stimulating hormones and prolactin are discussed in terms of current models of estrogen action. Proc Natl Acad Sci U S A, 1977 Nov, 74(11), 5046 - 50 Density-dependent regulation of growth of BSC-1 cells in cell culture: control of growth by serum factors; Holley RW et al.; BSC-1 cells grow slowly, to high cell density, in medium with 0.1% calf serum . An increase in the serum concentration increases both the growth rate of the cells and the final cell density . The serum can be replaced to some extent by epidermal growth factor (EGF) . Initiation of DNA synthesis in BSC-1 cells that have spread into a "wound" in a crowded cell layer requires the addition of a trace of serum or EGF, if the cells have previously been deprived of serum . The binding of 125I-labeled EGF to low-density and high-density BSC-1 cells has been studied . Binding is faster to low-density cells . Cells at low cell density also bind much more EGF per cell than cells at high cell density . The fraction of bound 125I-labeled EGF that is present on the cell surface as intact EGF is larger at low than at high cell density . The results indicate that the number of available EGF receptors per cell decreases drastically as the cell density increases . It is suggested that a decrease in the number of available EGF receptor sites per cell, and the accompanying decrease in sensitivity of the cells to EGF, contributes to density-dependent regulation of growth of these cells. Am J Vet Res, 1977 Nov, 38(11), 1765 - 8 Cell culture propagation of porcine rotavirus (reovirus-like agent); Theil KW et al.; Two isolates of porcine rotavirus (reovirus-like agent) were isolated and passaged in primary procine kidney cell cultures . Viral infectivity for cells was monitored by immunofluorescence because viral cytopathic effect was moderate . Successful passage of virus in cell culture required that viral suspensions obtained from infected cell cultures be treated with pancreatin prior to inoculation onto cell monolayers . Porcine rotavirus passage in cell culture also was accomplished, using trypsin treatments in lieu of pancreatin treatments . Porcine rotavirus passaged 10 times in cell culture infected gnotobiotic pigs and caused diarrhea . Gnotobiotic pigs that recovered from this infection were resistant to challenge exposure with porcine rotavirus but were susceptible to challenge exposure with transmissible gastroenteritis virus . As determined by immunofluorescent cross reactions, porcine rotavirus was found to be antigenically related to the human and bovine rotaviruses but not to reovirus type 3 or to transmissible gastroenteritis virus. Acta Virol, 1977 Nov, 21(6), 485 - 9 Induction of interferon in mice and cell cultures by Mycoplasma pneumoniae; Sokhey J et al.; Inoculation of mice and L and human embryonic lung (HEL) cell cultures with Mycoplasma pneumoniae failed to induce the production of interferon . M . pneumoniae multiplied in these cell cultures without a marked cytopathic effect . M . pneumoniae induced interferon in human peripheral blood leukocytes with maximum titres of 32 units/ml at 48 hours after infection. Biochem Genet, 1977 Oct, 15(9-10), 877 - 83 Isozyme and allozyme patterns in embryonic Drosophila cell culture lines; Alahiotis S et al.; Two independently derived embryonic Drosophila cell culture lines were examined for 19 gene-enzyme systems . At two loci, alpha-glycerophosphate dehydrogenase on chromosome 2, and isocitrate dehydrogenase on chromosome 3, allelic variation was detected . These can now serve as genetic markers to identify hybrid cell clones . Quantitative differences between cell lines were found for five enzymes. Am J Vet Res, 1977 Oct, 38(10), 1491 - 5 Comparison of intestinal (Illinois strain) and cell culture-adapted (M-HP strain) viral populations of transmissible gastroenteritis of swine; Morilla A et al.; Intestinal and cell culture-adapted viral populations of transmissible gastroenteritis (TGE) of swine were compared by means of sucrose gradient centrifugation, immunnofluorescence, electron microscopy, immune electron microscopy, statistical analysis of the number of plaque-forming units, and ultraviolet sensitivity . Results indicated that the size range and general coronavirus morphologic characteristics were shared by both viral populations . Marked morphologic variations existed among particles from both populations . Unlike the cell culture-adapted virus, the Illinois virus of intestinal origin was infractions representing 2 bands of infectivity which were isolated by the sucrose gradient centrifugation method . The intestinal and cell culture-adapted TGE viruses were similar in antigenicity and in sensitivity to ultraviolet irradiation . There was no indication of a 2nd virus in addition to the coronavirus described as the cause of TGE. Can J Comp Med, 1977 Oct, 41(4), 357 - 63 Transmissible gastroenteritis: demonstration of the virus from field specimens by means of cell culture and pig inoculation; Dulac GC et al.; Isolation of transmissible gastroenteritis virus was attempted from segments of jejunum collected from piglets submitted for diagnosis of transmissible gastroenteritis . The virus was isolated more frequently in susceptible piglets than in pig kidney or pig thyroid cells . Practically, both cell systems were equally capable of demonstrating the virus when the tissue suspensions were sonicated . The pig thyroid cells prepared with glands collected from minimal disease pigs were preferred to the pig kidney cells for initial virus isolation because of their ability to respond to transmissible gastroenteritis virus with a progressive cytopathic effect . However, the pig thyroid cells, prepared from pool of glands collected in abattoirs, were often contaminated with parvoviruses and could not be used for diagnostic work . Controlled ultrasound treatments of the inoculum increased the frequency of virus isolation in both cell systems. Mol Gen Genet, 1977 Sep 21, 155(1), 35 - 40 The ribosomes of Drosophila . Normal and defective ribosome biosynthesis in Drosophila cell cultures; Berger E; The assembly of proteins and RNA into mature ribosomal subunits has been studied in Drosophila cell cultures by pulse-chase experiments . Pulse labeled rRNA has a transit time of 3 h, while the transfer of ribosomal protein occurs completely within 30 min . Inhibition of protein synthesis by cycloheximide results in an almost immediate cessation of ribosome assembly, a result which indicates that no large pool of free ribosomal proteins exists in the cell . Substituting pre-ribosomal RNA with the analogue 5-fluorouridine (5-FU) results in a cessation of ribosome muturation . Under these conditions at least three large subunit proteins continue to accumulate on pre-existing cytoplasmic subunits, indicating an exchange . A portion of ribosomal subunit proteins synthesized in the presence of 5-FU can be recovered in cytoplasmic subunits once the effect of 5-FU has been reversed . This is most easily interpreted in terms of their stabilization on substituted pre-rRNA within the nucleolus, and subsequent utilization on unsubstituted RNA. Brain Res, 1977 Sep 16, 133(2), 329 - 39 Biochemical differentiation of aggregating cell cultures of different fetal rat brain regions; Honegger P et al.; Rotation-mediated aggregating cell cultures of mechanically dissociated fetal rat brains divided into three (telencephalon, mesencephalon-diencephalon and rhombencephalon), or two (telencephalon and mesencephalon-diencephalon plus rhombencephalon) parts were examined for their biochemical differentiation by measuring the specific activities of choline acetyltransferase, acetylcholinesterase, glutamic acid decarboxylase, tyrosine 3-monooxygenase, aromatic L-amino acid decarboxylase, catechol methyltransferase and monoamine oxidase . The results showed that such parts yielded cultures that were relatively enriched for acetylcholine-synthesizing (telencephalon) or catecholamine-synthesizing (mesencephalon-diencephalon and mesencephalon-diencephalon plus rhombencephalon) enzymes . For cultures which were derived from two brain divisions, the sum of the total activity for each enzyme in the parts after 30 days equalled that in whole brain cultures derived from the same group of embryos, suggesting that development of these enzymes was unaffected by division of the brain in two . In experiments to determine the effects of culture conditions on this development, chronic administration of certain drugs was found to selectively influence the specific activity of certain neurotransmitter metabolizing enzymes . Thus, in cultures of whole brain, ascorbic acid (0.2 mM) decreased tyrosine 3-monooxygenase and aromatic L-amino acid decarboxylase while other enzymes were slightly increased; and in cultures of telencephalon and mesencephalon-diencephalon plus rhombencephalon, N6, O2'-dibutyryladenosine 3',5'-cyclic phosphate (0.2 mM) decreased the specific activities of choline acetyltransferase acetylcholinesterase, glutamic acid decarboxylase and monoamine oxidase . These results demonstrate the feasibility of growing these cultures for pharmacological studies in developmental neurobiology. Cell Tissue Kinet, 1977 Sep, 10(5), 469 - 75 Comparison of growth characteristics of experimental tumours and derived cell cultures; Barendsen GW et al.; Cells from seven different rat tumours and a mouse sarcoma have been transplanted in syngeneic animals and were cultured in vitro . Tumours produced by inoculation of cultured cells in animals have been compared with the primary tumours . For the transplanted tumours, volume doubling times, T d, have been compared with doubling times, T d(cult), of cell numbers in cultures . Volume doubling times of the transplanted tumours generally decrease with increasing volume . At volumes of about 0-5 cm3, T d values range from 2-2 days to 10 days, while T d(cult) values ranged from 11 to 24 hr . A systematic correlation between T d and T d(cult) could not be established . During sequential transplantation of the tumours for many generations, as well as during continuous propagation of derived cell cultures, significant changes occurred which resulted in a decrease in the expression of differentiation characteristics in tumours. J Neuropathol Exp Neurol, 1977 Sep-Oct, 36(5), 842 - 5 Replication of measles virus in a cell culture from a glioblastoma of human origin; Fleury H et al.; A cell culture from a glioblastoma of human origin infected with the Edmonston strain of measles virus produced and released infectious measles virus . All cellular types seemed to be involved in the process of virus replication . Staining with hematin-eosin revealed the presence of eosinophilic intracytoplasmic and intranuclear inclusions . Examination with the electron microscope revealed viral nucleocapsids in the cytoplasm and, rarely, in the nuclei of infected cells. Tsitol Genet, 1977 Sep-Oct, 11(5), 409 - 18 {Action of cycloheximide on the ultrastructure and metabolic processes in a swine embryo kidney cell culture . I}; Struve ME et al.; Cycloheximide treatment (for 24 hrs, concentrations 1 and 10 microgram/ml) strongly inhibits the intensity of protein and DNA synthesis and the mitotic activity in cells of a pig embryo kidney culture, to a lesser extent inhibits the RNA synthesis in nuclei and nucleoli, reduces the activity of succinate-, lactate- and alpha-glycerophosphate dehydrogenases . There is a condensation of chromatin, a distortion of the granular endoplasmic reticulum integrity, a partial release of its membranes from the ribosomes, changes in the structure of the Golgi complex, morphology and ultrastructure of mitochondria . All these changes are secondary ones and are connected with the suppression of protein synthesis in cells. Vopr Virusol, 1977 Sep-Oct, (5), 565 - 8 {Survival of tick-borne encephalitis complex viruses in a brain cell culture from suckling mice}; Ladyzhenskaia IP et al.; The evidence of long-term survival of the tick-borne encephalitis complex viruses in primarily trypsinized brain cells of suckling mice inoculated in vivo is presented . The viability of the brain cell cultures from suckling mice inoculated with an attenuated strain was shown to be higher than that of a similar culture of the brain cells from suckling mice infected with a virulent strain . The infectious virus could be recovered for over 200 days of the existence of these cultures . The experimental results appear to be another confirmation of the capacity of viruses of the tick-borne encephalitis complex, particularly of the attenuated strains, for persistence. Am J Hum Genet, 1977 Sep, 29(5), 448 - 54 X-linked Hunter syndrome: the heterozygous phenotype in cell culture; Migeon BR et al.; Fibroblast cultures derived from the skin of three Hunter heterozygotes have been examined for iduronate sulfatase deficiency primarily by measurement of {35S}-mucopolysaccharide accumulation in the presence and absence of Hunter corrective factor . For each heterozygote, two populations of clones were observed: normal and enzyme deficient, as predicted by the Lyon hypothesis . However, the phenotype of the uncloned cultures was usually normal, presumably because of cross-correction, even after storage in liquid N2 . Mixing experiments indicate that the presence of a majority of cells with the Hunter phenotype may be obscured as the result of correction by the minority population of normal cells in the mixture . Variability in the ability to cross-correct was also demonstrated . The unpredictable behavior of uncloned cultures make them unsuitable for diagnosing the Hunter carrier state. Vopr Virusol, 1977 Sep-Oct, (5), 561 - 5 {Chronic cell culture infection with the rabies virus}; Bogomolova NN et al.; Three cell cultures chronically infected with fixed rabies virus, strain MNIIVP-74, have been obtained: HEp-2/2, BHK/13S, and RK-13 . In the former two cultures, the infectious virus titers were 2.0 to 5.25 Ig LD50/ml . In RK-13 cells, traces of the infectious virus were found . In the chronically infected HEp-2/2 culture the maximum amount of the antigen-containing cells determined by the fluorescent antibody procedure was 60% and in BHK/13S 80% . Chronically infected cultures had a reduced growth rate and were as sensitive as the controls of superinfection with vesicular stomatitis virus . The virus recovered from chronically infected culture produced a disease in mice at later intervals than the original virus used in the same doses. J Neurophysiol, 1977 Sep, 40(5), 1132 - 50 Mouse spinal cord in cell culture . I . Morphology and intrinsic neuronal electrophysiologic properties; Ransom BR et al.; 1 . Reliable methods for establishing fetal mouse spinal cord (SC) and dorsal root ganglion (DRG) cells in long term (greater than 1 mo) dissociated cell cultures are described . These cells have been studied by morphologic and intracellular electrophysiologic techniques . 2 . Cells studied electrophysiologically can be relocated after preparation for electron microscopy and examined in thin sections . The electron microscope shows that the surface membranes of these cells were directly accessible to the culture medium . The surfaces of SC cells were studded with synaptic boutons, whereas the DRG cell surfaces generally had none . 3 . Current-voltage relationships and linear electrotonic properties of the neurons are described . Delayed and anomalous rectification were seen in both cell types . The length of SC cell dendrites was about one characteristic electrotonic length, while little or no contribution of the relatively sparse DRG cell processes was seen in the transient responses of the DRG cells . 4 . Postspike and posttetanic hyperpolarizations in DRG cells were due to a surface membrane conductance increase; this was probably primarily an increase in K+ conductance . Post-activation hyperpolarization in SC cells was primarily due to activation of an electrogenic Na+ pump. Onderstepoort J Vet Res, 1977 Sep, 44(3), 139 - 42 Sheep erythrocyte and bluetongue virus antibody responses of spleen cell cultures from mice; Oellermann RA et al.; The optimum conditions for the culture of cells from dissociated spleens were determined . Routinely, 10(7) cells were seeded per ml of RPMI 1640 medium supplemented with 20% pre-tested foetal calf serum . For the assay of the immune response, cultures were supplemented with 30 muMolar mercaptoethanol . The immune responses to sheep erythrocyte and bluetongue virus antigens were determined by the haemolytic plaque-forming cell assays described by Oellermann (1974) and Oellermann, Carter & Marx (1976a) . The optimum sheep erythrocyte antigen concentration was 2 X 10(6) erythrocytes per 10(7) spleen cells and maximum IgM plaque-forming cells were detected after 4 days in culture . Successful stimulation of the immune response to bluetongue virus was achieved in spleen cell cultures from mice previously primed with bluetongue virus . The optimum antigen concentration was 30-40 ng bluetongue virus per 10(7) spleen cells and the maximum plaque-forming cell response was observed after 4 days in culture. J Gen Virol, 1977 Sep, 36(3), 377 - 84 Replication of enterovirus 70 in non-primate cell cultures; Yoshii T et al.; Replication of the strain J 670/71 of enterovirus 70 (EV70) in non-primate cell cultures at 33 degrees C was studied using strain L (mouse), BHK21 (hamster), RK13 (rabbit), RK17 (rabbit), PK15 (porcine), IB-RS-2 (porcine), ESK (porcine), MDBK (bovine), and BK1 (primary bovine) together with that of the LSc, 2ab strain of poliovrus type 1 (PV1) as a control . All the cells tested adsorbed from 54 to 90% of EV70 . The replication with complete c.p.e . was evident in RK13, RK17 and BK1 cells; replication without c.p.e . was shown in L, BHK21, IB-RS-2 and ESK; but PK15 and MDBK were non-permissive despite a high virus adsorption rate . On the contrary, none of these non-primate cells allowed the adsorption and growth of PV1 . One-step growth of EV70 in RK13 was almost identical with that in the primate cells . Two other strains of EV70 were found having similar host range in vitro . Therefore, it is concluded that EV70 has a wider host range in vitro than ordinary human enteroviruses, and its implication is discussed. J Neurophysiol, 1977 Sep, 40(5), 1151 - 62 Mouse spinal cord in cell culture . II . Synaptic activity and circuit behavior; Ransom BR et al.; 1 . Neurons in cell cultures of fetal mouse spinal cord (SC) and dorsal root ganglia (DRG) develop extensive synaptic interconnections . 2 . No spontaneous synaptic activity was detectable in the presence of tetrodotoxin or an elevated magnsium ion concentration, but statistical analysis of evoked excitatory postsynaptic potentials (EPSPs) indicates that the quantal size was 200-250 muV, which was below the noise level of the recording system used . 3 . In a sample of eight RDG-SC and seven SC-SC cell pairs linked by EPSPs, the quantal content of the SC-SC EPSPs was about 3.5-fold larger than for the DRG-SC EPSPs . 4 . The extrapolated equilibrium potential for the SC-SC EPSP was about 20 mV positive . The IPSP reversed at a membrane potential of 60-80 mV negative . 5 . Some examples of the types of synaptic circuits commonly encountered are given . Only one case of electrical coupling between neurons was found. J Neurobiol, 1977 Sep, 8(5), 417 - 27 Adult mouse dorsal root ganglia neurons in cell culture; Scott BS; A method has been developed for the long-term culture of dissociated adult mouse dorsal root ganglia (DRG) . Of critical importance to the success of this technique was a three-hour incubation in collagenase which softened the DRG and permitted gentle dissociation . The morphological and electrophysiological features of the dissociated adult DRG were similar to those observed in previous studies of immature (i.e., embryonic and newborn) DRG in culture and also to those of adult DRG in situ . With regard to electrophysiological work, the adult DRG neurons are superior to embryonic and newborn neurons because of their larger size and greatly increased survival in culture (no degeneration for first six days, and thereafter a relatively slow decrease) . The adult neurons regenerated nerve fibers to an extent comparable to that of immature neurons . Therefore, the adult DRG cultures might be useful to study factors influencing regeneration in the adult mammalian nervous system . The adult cultures might also be useful to investigated factors influencing the aging process. Scand J Dent Res, 1977 Sep, 85(6), 471 - 9 Toxicity of some dental cements in a cell culture system; Leirskar J et al.; A cell culture method has been used to study the effect of zinc phosphate cement (De Trey's Zinc Zement Improved), zinc silicophosphate cement (Fluoro-Thin) and polycarboxylate cement (Durelon) on animal cells . Disks (20 x 1 mm) of the materials were placed in the center of plastic Petri dishes and subsequently incubated with human epithelial cells . Cell multiplication, medium pH and the release of cement constituents were measured . All three cements exhibited a cytotoxic effect, which was most pronounced in the cultures with zinc silicophosphate cement and polycarboxylate cement . The results also indicated that cell growth on the surface of the disks is a more sensitive indicator of cytotoxicity than cell growth around the disks . pH of the medium was only slightly affected in cultures with polycarboxylate cement, whereas a decrease was found in cultures with zinc phosphate cement and especially with zinc silicophosphate cement . A rapid release of phosphate was found in cultures with zinc silicophosphate cement . Zinc was released into the medium from disks of zinc phosphate cement, zinc silicophosphate cement and polycarboxylate cement--exceeding the toxicity level for the present cell line after 24 h . In cultures with zinc silicophosphate cement and polycarboxylate cement the release of fluoride reached toxic levels within the same time interval. J Neurophysiol, 1977 Sep, 40(5), 1163 - 77 Mouse spinal cord in cell culture . III . Neuronal chemosensitivity and its relationship to synaptic activity; Ransom BR et al.; 1 . Mouse spinal cord (SC) cells in dissociated cell cultures showed strong electrophysiologic responses to glutamate, gamma-aminobutyric acid (GABA), and glycine when these were iontophoretically applied to the neurons . 2 . The extrapolated reversal potential for the glutamate response was 20-30 mV negative in contrast to the positive extrapolated reversal potential for the SC-SC excitatory postsynaptic potential . The data are interpreted as indicating different ionic mechanisms for the glutamate response and the EPSP . 3 . The reversal potentials for the glycine and GABA responses were similar to one another and to the IPSP reversal potential . The time course of the glycine and GABA responses were quite different from each other, however . 4 . While some SC cells showed a relatively uniform sensitivity over their surfaces to iontophoretically applied glutamate, discrete regions of higher sensitivity occurred on most cells . 5 . Release of excitatory and inhibitory transmitter could be elicited by focal application of glutamate and, in favorable instances, this could be shown to be due to the sensitivity of presynaptic terminals to the applied glutamate . Considerable spatial resolution of regions from which transmitter release could be elicited was achieved by this technique . Some correspondence between glutamate "hot spots" and such release sites was found. Z Parasitenkd, 1977 Aug 25, 53(1), 23 - 9 Development in cell cultures of Eimeria vermiformis Ernst, Chobotar and Hammond, 1971; Kelley GL et al.; Development of Eimeria vermiformis from sporozoite to mature first-generation schizonts in cultured bovine kidney cells, Madin-Darby bovine kidney cells, and primary cultures of whole mouse embryos is described . Intracellular sporozoites were seen at 5 min, and for as long as 120 h after inoculation . Sporozoites were observed penetrating cells, with uninucleate trophozoites and immature schizonts with 2--6 nuclei first appearing 24 h after inoculation . Schizonts with 6 or more nuclei, as well as mature schizonts containing first-generation merozoites, were first seen between 36 and 48 h after inoculation of all 3 cell types used . The first indication of merozoite formation was determined by the appearance of small protuberances of cytoplasm at the periphery of schizonts . Merozoites began development at the periphery of schizonts and were later observed radiating from a central body of cytoplasm, 14--20 merozoites being formed . Some mature schizonts retained a small spherical residual body after merozoite formation was completed . After the rupture of schizonts, intracellular merozoites, which contained anterior and posterior refractile granules, were seen at 48, 72 and 96 h postinoculation . Merozoites were not seen entering or leaving cells . No further development was observed. Arch Dermatol Res, 1977 Aug 22, 259(2), 125 - 34 Effects of glucocorticosteroids on primary human skin fibroblasts . II . Effects on total protein and collagen biosynthesis by confluent cell cultures; Ponec M et al.; Confluent cultures of normal primary human skin fibroblasts were incubated with various glucocorticosteroids which are in current use clinically for the treatment of various skin disorders . For all steroids concentrations were found at which collagen hydroxyproline formation was inhibited, while total protein synthesis was little affected . The concentration effective for inhibition was highest for hydrocortisone and lowest for clobetasol-17-propionate . All other steroids (hydrocortisone-17-butyrate, triamcinolone acetonide and betamethasone-17-valerate) showed medium effectiveness . Fluorination as such was not a factor in the degree of inhibition . The inhibition observed was shown to be independent of concomitant specific effects on cell proliferation or cell turnover . The possible implications of these findings on the therapeutic effects in psoriasis and the frequently occurring atrophic side-effects of these steroids are discussed. Mol Cell Endocrinol, 1977 Aug, 8(2), 95 - 103 Response to prolactin and ovarian steroids of normal mammary epithelial cell cultures; Ceriani RL et al.; Mouse mammary epithelial cells in confluent primary monolayer cultures retain responsiveness to the specific hormones that induce mammary growth in vivo . Simultaneous stimulation by prolactin, progesterone and estrogen, in the presence of 5 percent fetal calf serum, is required to induce an increase in both thymidine uptake into DNA and in cell replication (as judged by mitotic indexes) over the hormone-free control . This increase in mitogenic response could not be elicited in either mouse fibroblasts or in mouse mammary tumor cells, the latter known to be hormone insensitive. J Pathol, 1977 Aug, 122(4), 191 - 200 The ultrastructure of a porcine hereditary lymphoma with some observations on cell cultures and enzyme cytochemistry; Campbell JG; Ultrastructural studies have been made on affected tissues and cell cultures established from an hereditary lymphosarcoma of Large White pigs . Certain hydrolytic and lysosomal enzymes have been investigated at light microscope level in tumour cells and in cells established in culture . Morphological, behavioural and enzymatic characteristics indicate that two types of surface-adherent cells persist in primary cultures established from the marrow of affected pigs, namely macrophages and myeloid cells . The latter show an initial tendency to colonial growth which disappears in subsequent passages . In nearly all cases the tumour is considered to be a poorly differentiated lymphocytic lymphosarcoma . There is, however, considerable variation in cellular components and tumour-cell differentiation, and on purely morphological grounds one case might be considered to be an histiocytic i.e . macrophage lymphoma . Intra-nuclear bodies were observed in one case and occasional cytoplasmic virus-like particles were seen in both fresh tissues and cultured cells . In older pigs tumorous lymph nodes often show a cellular depletion associated with an increase of fibroreticular stroma. J Pharmacol Exp Ther, 1977 Aug, 202(2), 446 - 54 Antiproliferative activity of anti-inflammatory drugs in two mammalian cell culture lines; Hial V et al.; The nonsteroid anti-inflammatory drugs inhibited cell proliferation when added to rat hepatoma and human fibroblast cultures . The inhibition was reversible; normal growth resumed when the cultures were washed free of drug . Protein and nucleic acid synthesis, as measured by isotope incorporation was also reduced, although this reduction was probably a reflection of the decrease in cell numbers . An exception was that, in low concentration, the salicylate drugs, salicylamide, salicylic acid and aspirin, stimulated protein and nucleic acid synthesis, but in high concentrations (greater than 1 mM) they inhibited culture growth as well as protein and nucleic acid synthesis . Pharmacologically inactive derivatives, such as m-hydroxybenzoic acid and gentisic acid, were not inhibitory in concentrations up to 5 mM . The order of potency in inhibiting culture growth, meclofenamate greater than indomethacin greater than salicylamide greater than phenylbutazone greater than phenacetin greater than aspirin = salicylic acid, was similar to that reported for their anti-inflammator activity and their ability to inhibit prostaglandin synthesis . The antiproliferative activity of these drugs may, in part, account for their anti-inflammatory and toxic actions in vivo. Am J Clin Pathol, 1977 Aug, 68(2), 276 - 8 Comparison of primary rhesus and cynomolgus monkey kidney cell cultures for viral isolation from clinical specimens; Hollick GE et al.; Rhesus monkey kidney and cynomolgus monkey kidney cell cultures were compared for viral isolation by using clinical specimens that yielded 203 viral isolates . Cynomolgus and rhesus monkey kidney cells were comparable for the isolation of 22 adenoviruses, 12 coxsackieviruses, and one poliovirus . Four of 50 echoviruses and seven of ten herpesviruses were detected only in cynomolgus monkey kidney cells . Influenza virus was isolated in 84 instances, of which eight were detected only in rhesus and four only in cynomolgus monkey kidney cells . Rhesus monkey kidney cells yielded six more parainfluenza virus isolates . Except possibly for parainfluenza virus, cynomolgus monkey kidney cells appear to be as sensitive as rhesus monkey kidney cells for viral isolation from clinical specimens. J Protozool, 1977 Aug, 24(3), 416 - 9 Toxoplasma gondii-vertebrate cell interactions . I . The influence of bicarbonate ion, CO2, pH and host cell culture age on the invasion of vertebrate cells in vitro; Dvorak JA et al.; A controlled-environment culture system was used to show that both physical and biologic parameters can influence the penetration of vertebrate cells by Toxoplasma gondii . The optimum bicarbonate ion concentration for the penetration of bovine embryo skeletal muscle (BESM) cells is 36.25 mM . Higher or lower bicarbonate ion concentrations are increasingly inhibitory to penetration . As CO2 increases in the range from 0.5-3.7 mM, penetration is progressively inhibited . No relationship was found between penetration and pH in the pH range of 6.949-7.765 . The culture age of the BESM cells directly influenced the ability of the parasites to penetrate the cells . Older BESM cells were more refractory to penetration than younger cells. Biomedicine, 1977 Jul, 27(5), 185 - 7 The influence of alpha thioglycerol on erythropoiesis in fetal mouse liver cell cultures; Dunn CD et al.; alpha-Thioglycerol has been shown to increase hemoglobin synthesis in suspension cultures of fetal mouse liver cells . The mechanism of this effect is unknown but appears to be directly on S-phase cells increasing their sensitivity to erythropoietin . alpha-Thioglycerol inhibits heme synthesis when S-phase cells have been removed by prior treatment with hydroxyurea . The stimulatory or inhibitory effects of thiols depending on the proportion of cells in S-phase suggests that extreme caution should be used when interpreting cell kinetic studies of cultured cells if thiols are present in the cultures. In Vitro, 1977 Jul, 13(7), 417 - 22 Effects of bacterial agarase on agarose gel in cell culture; Carlsson J et al.; Bacterial agarase, concentrated and purified from culture filtrate of agar-degrading bacteria, has been used to clean cells cultured in soft agarose from gel residues . The enzyme also has been used to liquefy the gel directly in the dishes to facilitate the removal of cells . The sufaces of glioma cells from agarase-treated colonies could not be distinguished in the scanning electron microscope from surfaces of cells which had never been in contact with agarose or agarase . This implies that most agarose residues had been removed, and also that the treatment did not seriously alter the cell surfaces . The influence of the agarase treatment also was tested by comparison of the mitotic index and the incorporation of {3H}thymidine in agarase-treated and untreated cells . No effects of the treatment could be seen in these tests. Scand J Haematol, 1977 Jul, 19(1), 39 - 46 Cell culture studies in 19 cases of refractory aneamia: comparison of clinical data with in vivo erythrokinetic studies; Faille A et al.; A total of 19 cases of chronic refractory anaemia underwent simultaneous in vivo erythrokinetic study and in vitro bone marrow culture . They were followed up clinically for at least 2 years . Good correlation has been found between erythrokinetic data (simultaneous quantitative and qualitative disorders of erythroblastic proliferation in preleukaemic states; pure qualitative disorders in primary sideroblastic anaemia) and the results of culture of granulocyte precursors in the bone marrow (small number of colonies, reduced size of colonies in preleukaemic states; normal number and growth in non malignant refractory anaemia) . It would seem thus that both examinations are of practical interest in clinical haematology, making it possible to foresee the malignant evolution of some refractory anaemias. Exp Pathol (Jena), 1977 Jul-Aug, 14(1-2), 9 - 15 Human cell cultures infected by tumor-inducing and non-tumor-inducing viruses, an electron microscopic study; Sun CN et al.; This study is dealing with the infection patterns of adenovirus type 2 and type 12 on human fibroblast cell lines, KB, WI and MAF . With the exception of Ad -12 leads to WI, many intranuclear viral particles were present . None of these second passages (Ad-2 WI-WI, Ad-12 WI-WI, Ad-2 MAF-MAF, Ad-12 MAF-MAF) was found to have viral production . This indicates that the injections on both WI and MAF cells caused by both Ad-2 and Ad-12 cannot be serially transmitted . However, when these infected cells were used to expose KB cells, significant viral yields were obtained . This shows that the infected cells might still carry the viral specific antigens although no visible virions were observed. J Microsc, 1977 Jul, 110(2), 143 - 8 A specimen carrier, storage disc system for scanning electron microscopy (SEM): evaluation of stainless steel as a substratum for cell culture in vitro; Yeger H et al.; A method of sample preparation for scanning electron microscopy (SEM) studies based on the use of stainless steel discs as a cell culture substratum is described in detail . A number of different cell lines were grown on stainless steel, and the growth patterns and biocompatibility of cells cultured on stainless steel were compared to identical cells cultured on aluminium, glass and plastic substrata . Stainless steel provides cells with an excellent growth surface which allows these cells to retain their normal growth characteristics and appearance . The non-toxic stainless steel discs can be manipulated through any combination of fixatives and organic solvents . The discs have been incorporated into a versatile system of sample preparation for SEM. In Vitro, 1977 Jul, 13(7), 429 - 33 Uracil phosphoribosyl transferase activity of mycoplasma and infected cell cultures; Long CW et al.; Human H.Ep-2 and mouse 3T6 cells infected by Mycoplasma hyorhinis showed an increase in {3H}uracil uptake and a more than 20-fold increase in the activity of uracil phosphoribosyltransferase (UraPRT) . Uninfected cell cultures gave background levels of this enzyme activity . A survey of 16 strains of mycoplasma showed 13 to possess UraPRT activity . Rabbit kidney cells (RK13) were infected with eight different strains of four mycoplasma species known to be common cell culture contaminants . Seven of the eight cell cultures showed elevated UraPRT activities four days after infection . This enzyme activity may be of value in monitoring cell cultures for mycoplasma and aid in classification. Shika Rikogaku Zasshi, 1977 Jul, 18(43), 173 - 93 {Studies on the cytotoxic action of various silicone rubber impression materials by means of cell culture (author's transl)}; Watanabe H; Biological test of the silicone rubber impression materials was done by utilizing tissue cultures of L strain cells . Criteria for cytotoxicity were based upon response index in agar diffusion method which was determined by zone index and lysis index, and morphological observations of the cells . The materials used were chosen among those which were commercially available . Base material, catalyst, unset and set mixes of both materials were tested respectively . X-ray fluorescence analysis of the material was also performed . Following results were obtained . 1) Base material of all the materials showed zone index of a range between 11.8 mm and 18.6 mm . On the otherhand, lysis index was relatively small and minimum response index was 11.8 mm/8.6 mm . The cells appeared normal after cultivation with the base materials, though tissue culture medium became opaque due to dissolution of the base materials . It is revealed that the above results mean little cytotoxicity to the cells . 2) Catalyst, on the otherhand, yielded intense cytotoxicity . Minimum response index for the catalyst was 13.4 mm/14.8 mm . Morphological observation was parallel to the results of agar diffusion method . 3) Unset mixes also yielded intense to moderate cytotoxicity . 4) Set mixes showed a similar in level of cytotoxicity to the unset mixes . 5) X-ray fluorescence analysis of the materials revealed existence of such elements as Si, Sr, Sn, S, Cu and Fe . Moreover, Zn was found in materials A, B, C, D and E; P in materials A and B, and Pb in materials E and F . However, it was unable to show what compound was formed by these elements . It is expected that the present results could give a clue on animal experiments or clinical use from the view point of biocompatibility of silicone rubber impression materials. J Natl Cancer Inst, 1977 Jul, 59(1), 267 - 71 Lymphoproliferative diseases of fowl: JM-V leukemic lymphoblasts in cell culture; Hahn EC et al.; JM-V leukemic lymphoblasts were established in cell culture . The cultured cells (JM-VLC cells) were transplantable in young chicks and produced a disease indistinguishable from JM-V lymphoblastic leukemia as initiated by whole-blood inoculation . JM-VLC cells maintained a normal female karyotype through 13 passages in Rhode Island Red cockerels . With the use of JM-V antisera and antisera from birds with naturally occurring Marek's disease (MD), specific antigens were detected on the surfaces of living cells . Intracellular antigens were detected with anti-MD virus sera after cultivation for at least 1 day at 37 degrees C . In spite of the expression of MD antigens, the presence of herpesvirus particles associated with the cultured cells, and the occurrence of foci of multinucleated cells in kidney cultures from chicks inoculated with cellfree preparations of JM-VLC cells, the pathologic potential of the cultured cells was that of JM-V leukemia. Acta Virol, 1977 Jul, 21(4), 288 - 95 Investigation on the mechanisms of the failure of human influenza virus to replicate in chick embryo cell cultures; Mikheeva AV et al.; Thirteen strains of human influenza virus producing in chick embryo cell (CEC) cultures either virions with low infectivity or no virions were studied . In CEC, most of the strains induced synthesis of viral RNA, polypeptides, and ribonucleoprotein and produced functionaly active haemagglutinin, neuraminidase and virions lower infectivity . The low infectivity of virions produced by strains of this functional group was due to disturbed cleavage of a polypeptide, haemagglutinin precursor, formed in CEC, into a heavy a light haemagglutinin chain . Two strains belonging to another functional group induced no synthesis of virus-specific macromolecules in CEC, but were able to adsorb onto the cells . With one of these viruses, no transcription of parental RNA could be detected in CEC . There was no relationship between the grouping of the studied strains into a certain functional group with their antigenic characteristics, the year of isolation, the passage history in chick embryos and human pathogenicity. Experientia, 1977 Jun 15, 33(6), 755 - 6 Effects of carmine and carminic acid on embryonic tissue cell cultures; Marzona L et al.; The biological reaction to carmine and carminic acid at cellular level on 'in vitro' cultures was tested and significant variables were controlled . Results suggested that proliferation and metabolism of these cultures were not affected by the 2 stains. Biochem J, 1977 Jun 15, 164(3), 635 - 43 Effects of 5-bromo-2'-deoxyuridine on beating heart cell cultures from neonatal hamsters; Coetzee GA et al.; 1 . Primary heart cell cultures from neonatal hamsters yielded a heterogeneous cell population, containing muscle cells undergoing progressive differentiation, as well as non-muscle cells . 2 . Addition of 5-bromo-2'-deoxyuridine, at an early stage, to such cultures enhanced the formation of beating sheets of differentiated muscle cells . Accumulation of myosin heavy chains and creatine kinase also occurred in the presence of the analogue . 3 . To obtain these effects, the analogue had to be added during the initial rapid growth phase of the cells . Division of the treated cells then ceased when the cell numbers had approximately doubled . 4 . Similar results were obtained with other inhibitors of DNA synthesis . Thus improved muscle cell cultures can be obtained by preventing non-muscle cells from overgrowing the cultures . 5 . One effect caused only by 5-bromo-2'-deoxyuridine was a large increase in the Ca2+-stimulated ATPase (adenosine triphosphatase) activity which sedimented at low ionic strength . This increase was not due to a greater content of myofibrillar myosin, or to myosin isoenzyme changes, because purified myosin prepared from treated and untreated cultures did not exhibit the increased Ca2+-stimulated ATPase activity. Can Med Assoc J, 1977 Jun 4, 116(11), 1274 - 5 Male pseudohermaphroditism: diagnosis in cell culture; Pinsky L et al.; Testicular feminization is a classic form of complete male pseudohermaphroditism . The individuals have a normal XY karyotype but unambiguously female external genitalia . They have congenital complete insensitivity to androgen due to an X-linked mutation . In four patients (from tow families with several affected members) with the typical phenotype of testicular feminization, a severe deficit of specific androgen-binding activity was detected in cultured fibroblasts from labium majus skin . Measurement of this activity in genital skin fibroblasts improves the differential diagnosis in patients with complete or imcomplete male pseudohermaphroditism before puberty. Int Dent J, 1977 Jun 2, 27(2), 124 - 9 Biologic evaluation of filling materials . A comparison of results using cell culture techniques, implantation tests and pulp studies; Mjor IA et al.; The paper presents a comparison of results from cell culture studies, implantation tests and pulp studies using silicate cement, composite material and zinc oxide/eugenol cement . The three techniques allow differentiation between reactions produced by the materials, but a poor correlation exists between the results from the different techniques . This information is considered important for a selection of techniques for biologic testing of dental materials. Growth, 1977 Jun, 41(2), 147 - 58 Concanavalin A induced inhibition of cell migration in African green monkey kidney cell cultures; Simpson WA Jr et al.; The effect of concanavalin A (con A) on the mobility of Vero cells into cell free gaps is examined . The movement of cells into these wounds is inhibited by a 30 minute exposure of con A at a concentration of 12.5 ug/ml . The effects of con A on the mobility are dependent on the concentration of the lectin used for treatment as well as the total amount of time the cells are exposed to a given concentration . The con A inhibition is abrogated by alpha-methyl-mannose . The competitive effects of con A inhibition and serum migration stimulation factors are examined . Treatment of the monolayer prior to wounding inhibits as effectively as treatment after wounding, indicating that residual con A on the bed of the wound which the cells cross is not responsible for the demonstrated inhibition. Acta Pathol Microbiol Scand {B}, 1977 Jun, 85(3), 189 - 94 Interferon induction in human cell cultures by small molecular inducers (tilorone and acridines); Degre M et al.; Attempts were made to stimulate interferon production in human cell cultures by two related acridin drugs, mepacrine and Acranil . Tilorone was included for comparison . In human embryo lung fibroblasts and in normal human leukocytes only tilorone stimulated some interferon production . All three drugs stimulated modest interferon production in two lymphoblastoid cell lines . All three drugs enhanced the Sendai virus-induced interferon production in lymphoblastoid cells. J Med Genet, 1977 Jun, 14(3), 157 - 62 Differentiation in human amniotic fluid cell cultures: I: Collagen production; Priest RE et al.; The collagen produced by differentiated cells cultured from human amniotic fluid was characterized in two ways . By chain composition and by 4-hydroxyproline:3-hydroxyproline isomer ratio, the collagen synthesized by F-type (fibroblast) cells was indistinguishable from that made by cultured fetal dermal fibroblasts . The predominant cells in young amniotic fluid cultures, termed AF-type, produced collagen with a lower isomer ratio, resembling that of basement membrane collage . The chain composition, as determined by chromatography on carboxymethyl cellulose, varied for different cultures of the AF-type, but the major pattern was consistent with that of basement membrane collagen . On the basis of these characteristics, F cells are of fibroblast origin, whereas most AF cells are of a different origin either endothelial or epithelial . Other evidence (Megaw et al., 1977) suggests an epithelial origin for AF cells. Eur J Biochem, 1977 Jun 1, 76(1), 119 - 28 Characterization of a protein factor stimulating RNA synthesis by DNA-dependent RNA polymerase II from plant cell cultures; Link G et al.; During purification of DNA-dependent RNA polymerase II (or B) from cell cultures of parsley a protein fraction was separated by phosphocellulose chromatography which enhanced RNA synthesis in the presence of native homologous DNA . This 'stimulatory factor' was characterized in respect to some effects on the reaction catalyzed by RNA polymerase II . In the presence of the factor the metal ion requirements as well as the ionic strength for optimal RNA synthesis were markedly changed; addition of the factor to RNA polymerase II purified by cellulose chromatography restored those enzyme properties which had apparently changed upon this purification step . The chain length of the RNA product synthesized is favouring the view that the factor acts mainly by stabilizing the elongation step during transcription . The stimulatory factor was further purified by several steps of column chromatography . As derived from the results of gel electrophoresis under denaturing conditions the factor consists of several small polypeptides . Those of Mr = 26000, 25000 and 14000 apparently have counterparts among the smaller subunits of highly purified RNA polymerase II from parsley cells . Another polypeptide of the factor, with Mr = 30000, was only found in those preparations of RNA polymerase II which had not been subjected to phosphocellulose chromatography. Endocrinology, 1977 Jun, 100(6), 1539 - 49 Androgenic stimulation of progesterone production by granulosa cells from preantral ovarian follicles: further in vitro studies using replicate cell cultures; Hillier SG et al.; The influence of testosterone (T) on progesterone (P) production by isolated rat ovarian granulosa cells was studied in vitro using a new replicate culture technique . Preantral granulosa cells from ovaries of estrogen-primed hypophysectomized immature female rats were cultured in the presence of graded concentrations of T, diethylstilbestrol (DES), cyproterone acetate (CPA), flutamide and the hydroxylated derivative of flutamide, Sch 16423 . The accumulation of P in medium collected from granulosa cell cultures was measured by specific radioimmunoassay . Maximal P production by cultured granulosa cells was attained during the second day of culture and declined markedly thereafter . The presence of 10(-9), 10(-8) or 10(-7)M T elicited increases in P production 2.4, 8 and 11 times that of controls, respectively, during the initial 48 h of culture . Each concentration of T elicited enhanced P production within the first 24 h of culture . Granulosa cells cultured in control medium for 2 days did not respond to 10(-7)M T during the subsequent 3 days . DES at a high concentration in the medium (10(-5)M) markedly suppressed the response to 10(-9) and 10(-8)M T . At a lower concentration (10(-9)M) DES significantly enhanced the stimulatory effect of 10(-9)M T but did not alter the response to higher concentrations of T . Neither high nor low concentrations of DES influenced P production in response to 10(-7) M T . The stimulatory effects of T on P production were suppressed in the presence of a 100-fold molar excess of the anti-androgens, CPA or Sch 16423 . The present data indicate that androgenic stimulation of P production by preantral granulosa cells is a specific receptor mediated event which is modulated by the presence of estrogen in vitro . It is suggested that androgen-responsive P production is a functional capacity which granulosa cells acquire at a very early stage of hormonal differentiation and may be of physiological consequence in the intraovarian control of follicular maturation in vivo. Cancer Res, 1977 Jun, 37(6), 1611 - 7 DNA excision repair in ultraviolet-irradiated normal and malignantly transformed mouse epidermal cell cultures; Bowden GT et al.; Pyrimidine dimer production and excision was studied in ultraviolet light (UV)-irradiated primary cultures of epidermal cells derived from perinatal mouse skin and in an in vitro malignantly transformed epidermal cell line . Dimer production increased linearly with UV dose level for both cell types . However, at any given UV dose level, there were 20% fewer thymine-containing dimers induced in the primary cultures compared to the transformed cell line . The reduced dimer yield in the primary cultures was attributed to the multilayer (three cell layers) of these cultures . The primary cultures were found to exicse no more than 10% of the original dimers in a 24-hr period, while the malignantly transformed cells excised 34% . Nonsemiconservative DNA repair synthesis was also studied as a function of dimer yields in the first 3 hr after irradiation . When the levels of repair replication in both cell types were compared at equal yields of UV-induced dimers, the malignantly transformed cells exhibited a higher level of repair than did the primary epidermal cells . There was no difference in the kinetics of repair replication between the two cell types at a UV dose level of 10 J/sq m over the first 6 hr after irradiation. Biken J, 1977 Jun, 20(2), 57 - 67 Ultrastructural study of cell cultures infected with swinepox and orf viruses; Kim UH et al.; Monolayer cells of a porcine kidney cell line were infected with the PP-1 strain of swinepox virus, while secondary or third subcultured monolayer cells of African green monkey kidney were inoculated with the Iwate BT-9 strain of orf virus . Those infected cells were fixed when CPE became remarkable in the monolayers and examined by electron microscope . In the cytoplasm of cells infected with both viruses, various immature forms of viral particles in different developmental stages were observed . Micells were detected very close to the opening of immature particles . Mature particles asssociated with a double membrane were frequently observed . From those observations it was suggested that the developmental sequence of both viruses is essentially the same as that of vaccinia (Dales, 1973) . Besides various virus forms as well as factories, the following ultrastructural changes were noted in swinepox infected cells, i.e . 1) intranuclear inclusions which consist of very fine filaments, 2) fibrillar structures with cross striations located in the nuclear inclusions, and 3) similar striated fibrillar structures in or just adjacent to virus factories (B type inclusions) in the cytoplasm . Those observations made with in vitro cells are in good accordance with the descriptions by previous investigators on in vivo materials . Accordingly those ultrastructural changes characterize the swinepox infection. J Med Genet, 1977 Jun, 14(3), 163 - 7 Differentiation in human amniotic fluid cell cultures: II: Secretion of an epithelial basement membrane glycoprotein; Megaw JM et al.; Cells obtained by amniocentesis for prenatal diagnosis were grown in vitro and examined for the presence of a glycoprotein component epithelial basement membrane . Isolated colonies or clones of amniotic fluid-type cells secrete the glycoprotein, which was identified in association with the cells using indirect immunofluorescent antibody techniques . In addition, the glycoprotein was isolated from tissue culture medium and identified as a component of epithelial basement membranes by passive haemagglutination (PHA) and immunodiffusion assays . Fibroblast-type cells do not secrete the glycoprotein . These results correlate well with the synthesis of type IV collagen by amniotic fluid cells reported in the accompanying paper (Priest et al., 1977) and indicate that amniotic fluid cells are epithelial in origin. In Vitro, 1977 Jun, 13(6), 389 - 97 Fish cell culture characteristics of a cell line from the silver perch Bairdiella chrysura; Wharton JH et al.; A cell designated SP-1 was established from tissue of the silver perch, Bairdiella chrysura . Cells were fibroblast-like and grew best at 26 degrees C in Leibovitz medium (L-15) containing 15% fetal bovine serum and 0.150 M sodium chloride . Passage 1 to passage 9 SP-1 cells contained a chromosome number of 48; at passages 27 and 50 the modal numbers were 51 and 54, respectively . Confirmation of the origin of SP-1 cells was made by the cytotoxic antibody dye-exclusion test . This cell line supported the growth of lymphocystis virus from the silver perch but was not found to replicate various other fish and mammalian viruses. Cancer Res, 1977 Jun, 37(6), 1845 - 51 Detection of chemical carcinogens by unscheduled DNA synthesis in rat liver primary cell cultures; Williams GM; Unscheduled DNA synthesis was observed in primary rat liver cell cultures treated with members of five different classes of chemical procarcinogens requiring enzymatic activation as well as with a direct-acting carcinogen . In total, ten carcinogens and one related analog not commonly accepted as carcinogenic were active, while one weak carcinogen and four noncarcinogens were inactive . The production of unscheduled DNA synthesis by this spectrum of chemical carcinogens indicates that these cultures have substantially retained the metabolic capability of liver for activating diverse procarcinogens . Thus, such cultures may be useful for detecting the ability of chemicals to interact with DNA and, thereby, assigning them priority for consideration as potential cancer-causing agents. J Microw Power, 1977 Jun, 12(2), 125 - 32 Rat lymphocytes in cell culture exposed to 2450 MHz (CW) microwave radiation; Hamrick PE et al.; Rat lymphocytes were exposed to continuous wave microwave radiation at a frequency of 2450 MHz at intensities of 5, 10 and 20 mW/cm2 . The corresponding rates of absorption of energy were determined to be 0.7, 1.4 and 2.8 mW/g . The lymphocytes were exposed for 4, 24 or 44 h either with or without the addition of a mitogen (phytohemagglutinin) . The transformation of lymphocytes into lyphoblasts was monitored by the addition of tritiated thymidine . No significant differences (P less than .05) were found in the uptake of tritiated thymidine between exposed and control cultures. In Vitro, 1977 Jun, 13(6), 357 - 65 Mycoplasma in African green monkey kidney cell cultures: biochemical detection and effects in virus-infected cells; Van Roy F et al.; Among a number of techniques for the detection of mycoplasmal contamination in African green monkey kidney (AGMK) cell lines, the assay of uridine phosphorylase activity is unsuitable because of the presence of high levels of endogenous enzymatic activity . A thymidine phosphorylase test, however, based on the chromatographic analysis of radiolabeled thymidine breakdown, turned out to be a simple and sensitive mycoplasma detection method . We found, using the latter technique, that 0.22-micrometer-filtered virus inocula could still transfer mycoplasma unless treated with diethyl ether . The effect of mycoplasmal contamination on the synthesis of simian virus 40 and adenovirus in AGMK cells was negligible under the conditions used (no depletion of arginine) . Incorporation of radioactive thymidine in viral macromolecules, however, was inhibited severely by the presence of mycoplasma. Cancer Res, 1977 Jun, 37(6), 1709 - 14 DNA transfection of ecotropic murine leukemia viruses in mouse cell cultures; Hsu IC et al.; DNA's were isolated from cells chronically infected with N-, B-, or NB-tropic murine leukemia viruses and tested for infectious activity in various mouse cell cultures . Early detection of the DNA transfection is facilitated by growing the DNA-recipient cells in medium containing 10(-6) M hydrocortisone . Appropriate shearing of the DNA preparations may increase the efficiency of the transfection . With these procedures virus production of the transfected cells can be detected by XC plaque assay as early as 4 days after DNA inoculation in NIH 3T3 cells . Susceptibility of the mouse cell cultures to DNA transfection does not parallel their susceptibility to virion infection . Progeny viruses derived from the transfection show the same N- or B-tropic host range property as do the parent viruses. Calcif Tissue Res, 1977 May 31, 23(1), 61 - 6 Species differences in cell culture of mammalian articular chondrocytes; Webber RJ et al.; Articular chondrocytes from eight mammalian species (rabbit, opossum, woodchuck, cat, dog, sheep, rhesus and cebus monkeys) were grown in monolayer culture using a single regimen . The animals were immature or young adults . Ham's F12 medium supplemented with 10% fetal bovine serum was employed for the primary cultures and Dulbecco-Vogt medium, for the secondary . Marked species differences were found with respect to cell morphology, growth in primary and secondary cultures, incorporation of radiosulfate into macromolecules, adhesion to the flask surface, response to vitamin C, and chondroid expression in spinner bottles . Under these particular conditions, rabbit chondrocytes grew most rapidly and incorporated several times more sulfate than did the others . Additional experiments carried out with other media on four of the species indicate that optimal conditions for culturing mammalian chondrocytes must be determined for each species individually. Brain Res, 1977 May 13, 126(3), 397 - 42 Rat hippocampal neurons in dispersed cell culture; Banker GA et al.; An in vitro system has been developed for the study of isolated hippocampal neurons from 18- or 19-day rat fetuses . Following trypsinization the cells are plated out at low density on polylysine-treated coverslips in an enriched medium . The isolated neurons rapidly attach to the substrate and initiate process extension . Little reaggregation occurs and the number of non-neuronal cells present is minimal . Unless co-cultured with tissue explants the neurons survive for only a few days; in the presence of hippocampal explants the initial growth of the isolated cells is improved and their survival in culture is extended to about two weeks . Some of the cells in such cultures develop a characteristic branching pattern closely resembling that of maturing hippocampal pyramidal cells in vivo . There is a clear relationship between the stage of the cells' development and their growth in culture . Cells which had completed DNA synthesis about 48 h before dissociation, and which were in the process of migration to the cortical plate, survived best in our cultures . Early post-mitotic cells which were still within the ventricular zone and cells which had already reached the cortical plate grew poorly . This system should permit the study not only of process formation by these cells, but also of their capacity to form specific synapses in vitro and of the biochemical constituents of their surfaces. J Neuropathol Exp Neurol, 1977 May, 36(3), 576 - 85 Differential radiosensitivity of mouse embryonic neurons and glia in cell culture; Dambergs R et al.; The responses of neurons and glial cells to ultraviolet and gamma-radiation were studied in cell cultures of embryonic mouse brains . A decrease in the ratio of glia to neurons occurred after both forms of irradiation . {3H}thymidine labelling followed by autoradiography revealed that all glia were capable of replication wereas 70% of neurons were non-replicating under the conditions of the study . Ultraviolet radiation caused a decrease in the proportion of replicating neurons but did not affect the proportion of replicating glia, whereas gamma-radiation caused a decrease in DNA replication in both cell types . Levels of ultraviolet radiation-induced unscheduled DNA synthesis were lower in neurons than in glia . It is concluded that sensitivity to both ionizing and ultraviolet radiation of neurons and glial cells in embryonic brain cultures is determined primarily by the capacity for and state of DNA replication . Neurons which have already reached the stage of ternimal differentiation are more resistant than replicating neurons of glial cells. J Natl Cancer Inst, 1977 May, 58(5), 1377 - 82 Morphologic character of transforming renal cell cultures derived from Wistar rats given dimethylnitrosamine; Hard GC et al.; The morphologic character of kidney cells during serial subculture following isolation from Wistar rats treated several hours to 1 week previously with a carcinogenic dose of dimethylnitrosamine (DMN; 60 mg/kg body weight following protein deprivation) was compared with the appearance of cultures derived from normal control rats . Apart from early signs of cell toxicity, cultures from DMN-treated rats appeared similar to those from untreated rats for the first four passages . Control cells underwent senescence usually by subculture 4, whereas the test cultures survived to express morphologic transformation (usually at subculture 5) as dense macroscopic colonies of piled up cells . In 18 of the 20 test cultures, the cell populations that persisted in continuous culture following expression of morphologic transformation were exclusively mesenchymal, closely resembling DMN-induced renal mesenchymal tumor cells in continuous culture . In the remaining 2 test cultures from DMN-treated rats, a persisting population of abnormal epithelium was present in addition to morphologically transformed mesenchymal cells . The occurrence of populations of altered mesenchymal and epithelial cells characterized by prolonged survival in vitro following isolation from rats shortly after treatment with a carcinogenic dose of DMN was believed to be related to the long-term induction in the rat kidney of a high incidence of mesenchymal tumors and a lower incidence of cortical epithelial tumors by the same dose schedule. Endocrinology, 1977 May, 100(5), 1306 - 16 Estrogen regulation of follicle stimulating hormone in cell cultures of sheep pituitaries; Miller WL et al.; Cell cultures of ovine pituitaries were maintained for up to 3 weeks . A specific double antibody radioimmunoassay was used to measure FSH in the media and cells . The rate of FSH synthesis increased in the cultures during the first 4-6 days to a level of approximately 50 ng/day/106 cells, generally remained constant for 2 weeks and then decreased . The FSH produced in vitro migrated similarly to highly purified ovine FSH on P-60 polyacrylamide gel filtration columns and had a biological potency essentially identical to that of the highly purified FSH standard . Addition of 17beta-estradiol (E2) at 10-9M on days 2 or 6 incubation decreased FSH synthesis greater than 95% within 30 h . Time-course analysis revealed that the effect of E2 can be observed as early as 6 h after treatment . FSH synthesis resumed after removal of E2 and reached control levels within 6 days . The lowest effective dose of E2 was 10-11M; E2 at 5 X 10-11M maintained FSH production at approximately 50% of the control levels . Diethylstilbestrol was as active estriol was 1/10th as active and 17alpha-estradiol was 1/100th as active as E2 . Progesterone (P), 5alpha-pregnane-3,20-dione (5alphaDHP), 20alpha-hydroxy-pregn-4-en-3-one(20alpha-OHP), testosterone, 5alpha-dihydrotestosterone and corticosterone had no effect on FSH levels . These findings suggest that estrogen is capable of playing a major role in FSH synthesis and release by action directly at the pituitary level. Vopr Virusol, 1977 May-Jun, (3), 274 - 9 {Persistent infection of pig embryo kidney cell cultures caused by a variant of tick-borne encephalitis virus}; Gavrilov VI et al.; The results of modelling and study of persistent infection of pig embryo kidney cell cultures (PEK) with MF variant of tick-borne encephalitis (TBE) virus are presented . In the life of chronically infected cultures periods of formation and stabilization were observed which were characterized by different types of relationships between the persisting virus and the cells . By the characters under study the persisting virus did not differ significantly from the initial MF variant . Inoculation of PEK and BHK-21 cell monolayers with samples of DNA from chronically infected cultures permitted to isolate transfected agents . Their identification by the neutralization tests and the indirect immunofluorescence procedure confirmed that they belonged to TBE virus . It is suggested that the mechanism of TBE virus persistence in PEK-MF system is based on the integration of TBE virus genome with DNA of chronically infected PEK cells. J Physiol, 1977 May, 267(2), 281 - 98 The action potential of chick dorsal root ganglion neurones maintained in cell culture; Dichter MA et al.; 1 . The directly evoked action potential of dissociated, embryonic, chick, dorsal root ganglion (DRG) neurones maintained in cell culture is prolonged compared to spinal cord cell spikes and the re-polarization phase is marked by a plateau . 2 . Evidence was obtained that both Ca2+ and Na+ carry inward current across the active soma membrane . Ca2+ because: overshooting spikes persist in tetrodotoxin (TTX) or Na+-free media; in the presence of TTX (or absence of Na+) spike size varies directly with extracellular Ca2+ and spikes are eliminated by Co2+ . Na+ because: spikes persist in the presence of Co2+ or Ca2+-free media; in the presence of Co2+ (or absence of Ca2+) spike varies directly with extracellular Na+ and spikes are blocked by TTX . 3 . On the other hand, Ca2+ plays less if any role in action potentials conducted along sensory nerve cell processes . Conducted spikes could not be evoked in TTX containing or Na+-free media . 4 . A long-lasting depolarization follows the action potential in some neurones . This depolarization is associated with an increase in membrane conductance and appears to drive the membrane potential to ca . -30mV . It persists when conducted impulses are blocked so it is probably not a recurrent synaptic potential . 5 . It is suggested that combined Ca2+-Na+ spikes observed in isolated sensory neurones in vitro reflect the action potential of adult sensory cells but the possibility that they represent an early stage in development is also discussed. Can J Microbiol, 1977 May, 23(5), 624 - 6 The use of cell cultures from the chorioallantoic membrane of chick embryos for studies of chlamydiae; Kordova N et al.; Cells of the chorioallantoic membrane of chick embryos were processed into monolayer cell cultures by a recently described technique of Cursiefen and Brecht . The cultures provided a sensitive substrate for the quantification of infectivity of C . psittaci strain 6BC and meningo-pneumonitis. Scand J Dent Res, 1977 May, 85(4), 291 - 6 Evaluation of biologic effects of dental materials using four different cell culture techniques; Hensten-Pettersen A et al.; The cytotoxicity of fresh and 1-day-old silicate cement, composite restorative material and zinc oxide-eugenol cement (ZOE) was tested using human epithelial cells (NCTC 2544) in four different cell culture systems: (1) 51Cr-release from prelabeled cells after incubation for 4 and 24 h in the presence of the materials . (2) Implanting the materials on an agar everlay and visualizing any cytotoxic effects after 24 h by neutral red vital stain . (3) Cell growth during 5 d in the presence of the materials . (4) Colony-forming ability after exposure of the cells for 30 min to medium previously incubated with the materials for 24 h . Freshly prepared and 1-day-old ZOE exhibited a prominent cytotoxic effect in all four systems . A less marked effect was found for the composite material in systems 2, 3, and 4, while silicate cement appeared to be the least toxic material in these three systems . Neither silicate cement nor composite showed any cytotoxic effect in system 1 based on 51Cr-release . It is concluded that the effects obtained by the cell culture techniques did not mimic the reactions obtained when the materials are tested under conditions which reflect their clinical use. Infect Immun, 1977 May, 16(2), 480 - 5 Human nasal epithelial cell culture system: evaluation of response to human interferons; Harmon MW et al.; This report describes the response of human nasal epithelial cells to exogenously applied human interferon (IF) . To measure the response, a system developed to study human nasal epithelial cells in vitro was used . Nasal epithelial cells responded equally to both leukocyte and fibroblast IF, with development of resistance to virus replication that was time and dose dependent . Cells required contact with 1,000 U of IF (400 69/19 reference units) for 4 h to produce consistently a significant reduction in virus yield . This in vitro cell cultured system may be useful in predicting the in vivo response of human IF in respiratory viral infections. J Natl Cancer Inst, 1977 May, 58(5), 1239 - 45 A solid-phase radioimmunoassay for Epstein-Barr virus-associated membrane antigen prepared from B95-8 cell culture supernatants; Dolken G et al.; Epstein-Barr virus(EBV)-associated membrane antigen (MA) was concentrated from B95-8 cell culture media by precipitation with polyethylene glycol followed by chromatography on Bio-Gel A-50m . In a RAJI cell-binding assay, MA-positive material could only be found in the void volume of the column . After ultracentrifugation all antigenic activity appeared in the pellet, which suggested that MA was present in aggregates, presumably fragments of cellular membranes and/or virus envelopes . The MA-containing preparation was photopolymerized in polyacrylamide gel . The homogenized gel was used in a solidphase radioimmunoassay with 125l-labeled IgG from an Anti-MA positive reference serum and an anti-MA negative control serum . The specificity of the reaction was confirmed in blocking tests with anti-EBV positive and negative sera . A good correlation was found between the results obtained in the radioimmunoassay and the results obtained in direct immunofluorescence tests for the detection of MA . The existence of at least two subspecificities of the MA complex could be confirmed by this radioimmunoassay. Can J Biochem, 1977 May, 55(5), 571 - 5 alpha-Fetoprotein production and erythropoiesis in cell cultures of human fetal liver; Congote LF et al.; alpha-Fetoprotein and the synthesis of heme associated with hemoglobin were measured simultaneously in short-term cultures of human fetal liver cells to correlate the relationship of alpha-fetoprotein to erythroid cell function . Both synthetic processes decreased exponentially during the first 5 days of culture . The use of media supplemented with different batches of fetal calf serum and porcine portal vein serum indicated that the optimal conditions for the production of alpha-fetoprotein were different from those required for the synthesis of heme associated with hemoglobin . Moreover, the alpha-fetoprotein-producing cells could be separated from erythroid cells after velocity sedimentation in Ficoll gradients . Although it is well known that erythropoiesis and alpha-fetoprotein production occur simultaneously during ontogenesis, alpha-fetoprotein itself (0.01-100 micron g/ml) did not stimulate heme synthesis in liver erythroid cells . Erythropoietin did not stimulate alpha-fetoprotein production . It is concluded that there is no cause-effect relationship between alpha-fetoprotein production and erythroid cell fuction in human fetal liver cells and that the two processes occur independently in different cell types. Am J Vet Res, 1977 May, 38(5), 591 - 5 Isolation of a herpesvirus from the cell culture of a malignant melanoma of a ground squirrel (Spermophilus tridecemlineatus); Dutta SK et al.; A subcutaneous neoplastic mass in a 13-lined ground squirrel which metastasized to regional lymph nodes and lung was studied . Histopathologically, the tumor architecture and cellular morphology were compatible with that of a malignant amelanotic melanoma . Ultrastructurally, the neoplastic tissue was composed of oval cells, spindle-shaped cells, and spindle-shaped cells with electron-dense cytoplasmic granules . Virus particles were not seen in these cells . Cell cultures from neoplastic tissue grew in complete monolayers and on initial passages contained a few herpesvirus particles . Secondary monolayer cell culture, when exposed to 5-iodo-2'-deoxyuridine or made into several serial subculture passages, caused the appearance of cytopathic effect and the demonstration of many virus particles . The ground squirrel agent, because it contained DNA, was sensitive to chloroform treated and had herpesvirus characteristics on electron microscopy, was considered a herpesvirus . The buoyant density of the virus was 1.298 g/cm3 and the diameter of the enveloped virus particles was 146 nm . This ground squirrel herpesvirus was antigenically distinct from other known herpesviruses. Acta Virol, 1977 May, 21(3), 268 - 70 Scanning and transmission electron microscopy of Rickettsia rickettsii propagated in cell culture; Pedersen CE Jr et al.; Scanning electron microscopy utilizing critical-point drying and transmission electron microscopy employing air-dried agar pseudoreplicas and critical-point dried carbon replicas were used to study the surface of Rickettsia rickettsii propagated in cell culture. Acta Virol, 1977 May, 21(3), 241 - 5 Improved methods of influenza virus propagation . II . Characteristics of cell culture and allantoic virus preparations; Sominina AA et al.; Regular reproduction of influenza A virus with infectious titres of 7.4--8.5 log EID50/0.2 ml was observed in roller bovine embryo kidney cell cultures . The haemagglutinating activity of the cell culture preparations was 8-33-fold lower than that of the allantoic preparations, the infectivity being similar . Cell culture preparations of influenza A/Victoria/35/72 and A /Leningrad/538/74 viruses were markedly immunogenic in laboratory animals and antigenically active in complement fixation (CF) test . The CF activity of liquid and lyophilized preparations remained unchanged for 12--13 months (the period of observation) . The stability of infectivity of lyophilized cell culture virus preparations was similar to that of allantoic virus preparations. Acta Virol, 1977 May, 21(3), 234 - 40 Improved methods of influenza virus propagation . I . Enhancement of virus reproduction in cell cultures; Lisok TP et al.; Comparative studies on the reproduction of a set of influenza A and B virus strains in different