Cell cultures

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 cell cultures were carried out . A cultivation system yielding influenza virus with high infectivity, based on the use of roller cultures of bovine embryo kidney cells, of virus strains adapted to this culture, and of a maintenance medium of improved composition, was developed.

J Biol Chem, 1977 Apr 25, 252(8), 2726 - 33
Lipoprotein regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in rat liver cell cultures; Breslow JL et al.; A primary cell culture technique was used to study the effects of lipoproteins on rat hepatocyte 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity . In this system, lipoproteins prepared from normocholesterolemic rat and human plasma, including low density lipoproteins, did not inhibit hepatocyte HMG-CoA reductase activity whereas very low density lipoproteins and high density lipoproteins isolated from the same sources were stimulatory . A lipoprotein was isolated from the plasma of cholesterol-fed rats that did inhibit hepatocyte HMG-CoA reductase activity . An extensive chemical characterization of the inhibitory lipoprotein revealed that it was mainly d less than 1.019 g/ml and had beta mobility on lipoprotein electrophoresis . The lipoprotein was compared to the comparable density fraction in the normocholesterolemic rat plasma and there was no size difference appreciable by negatively stained electron micrographs . However, two important differences in chemical composition were evident: in the inhibitory lipoproteins the per cent of total apoprotein which was in the region of Mr = 35,000 was increased 1.5- to 2-fold, and there was a marked increase in cholesterol ester content . These chemical characteristics may be required for lipoproteins to regulate hepatocyte cholesterol synthesis . Primary cell culture of rat hepatocytes appears to be a useful system in which to study cholesterol metabolism in the liver.

Biochem J, 1977 Apr 15, 164(1), 273 - 5
Effects of dolichol monophosphate on galactose incorporation into glycoconjugates of cell cultures; McEvoy FA et al.; Cultured-cell homogenates catalysed the incorporation of galactose from UDP-galactose into protein and sphingolipid acceptors . Dolichol monophosphate stimulated the incorporation of galactose into glycoproteins, but it did not affect the rate of glycosylation of either exogenous or endogenous glycosphingolipids . It is proposed that, under certain conditions, galactose may be incorporated into glycoproteins via polyisoprenol intermediates, as is the case with N-acetylglucosamine and mannose.

Ann Microbiol (Paris), 1977 Apr, 128A(3), 339 - 48
{Irradiated cell cultures applied to group A "chlamydiae" isolation (author's transl)}; Catalan F et al.; The irradiated Mc Coy cell cultures method modified by Darougar et al . has been used to investigate the frequency of Chlamydiae in non-specific genital tract disease, in Reiter's disease and in patients suffering from conjonctivits associated with non-specific urethritis . Isolates were obtained from 104 men of the 660 suffering from acute urethritis, and from 18 men of the 67 suffering from conjonctivitis associated with urethritis . Fourteen female sexual contacts of these men were tested: Chlamydiae was isolated from 9 . Seven patients suffering from acute Reiter's disease were tested: Chlamydiae was isolated from 4 . These patients were tested by complement fixation and titers of 1/8 or more were only obtained in the 4 isolated positive cases, the three other cases remaining negative . Isolates of Chlamydiae were obtained from 10 women of the 67 women suffering from exocervicitis . No isolate was obtained, from 27 control patients.

Can J Comp Med, 1977 Apr, 41(2), 226 - 9
Propagation of the rotavirus of neonatal calf diarrhea in fetal intestinal cell cultures; Mohammed KA et al.; Bovine fetal intestinal cells were successfully propagated in monolayer cultures for up to 21 passages . Infection of these cells with the rotavirus of neonatal calf diarrhea resulted in a cytopathic effect that was more obvious than in infected bovine fetal kidney cells.

Br J Dermatol, 1977 Apr, 96(4), 421 - 6
Induction of basal lamina formation in epidermal cell cultures in vitro; Mann PR et al.; Guinea-pig epidermal cells were grown on 2 types of rat collagen substrate . The cells showed the same sort of differentiation as occurs in cells growing on rigid plastic . In addition, basal lamina formed patchily at the interface with collagen . If the collagen was eroded away the basal lamina also disappeared.

Biull Eksp Biol Med, 1977 Apr, 83(4), 467 - 70
{Study of a trophoblast cell culture in vitro}; Trunova LA et al.; The authors obtained trophoblast culture from an early chorion of human embryo . Trophoblastic cells of the main 4 types described were: giant cells, with processes, fibro-blast-like, and round . All the cells were rich in RNA, glycoproteins, had a set of enzymes of the Krebs pentose cycle, but low activity of succinic dehydrogenase . A marked cytooxic effect of lymphocytes from healthy pregnant woman on the allogenous cells of the trophoblast culature and the absence of any interaction between the neoatal lymphocytes with the latter was revealed.

Ann Rheum Dis, 1977 Apr, 36(2), 130 - 8
Lysosomal activation by neutral saccharides in cell cultures of synovium; Marshall JL et al.; On exposure to sucrose or neutral polysaccharides, cell cultures from human synovium showed cytoplasmic vacuolation, increased numbers of lysosomes, and ultrastructural changes simulating those described in rheumatoid synovial intima and similarly treated embryonic caritlage and bone . These changes were accompanied by raised intracellular lysosomal enzyme activity without corresponding increases in the extracellular level of these enzymes . Structural changes and enzymic responses were less intense during exposure to the neutral polysaccharides . The secretion of large polymers of hyaluronic acid was consistently decreased during sucrose treatment . Evidence of heightened hyaluronidase-like activity was found in cellular extracts of sucrose-treated cultures, but not in the culture medium.

Clin Genet, 1977 Apr, 11(4), 243 - 8
Chromosome polymorphisms in karyotypes from amniotic fluid cell cultures; Barker PE et al.; Frequencies of 12 fluorescent chromosome polymorphisms were scored from Q-banded karyotypes derived from 108 midtrimester diagnostic amniotic fluid cell cultures . The most frequent variants were the bright fluorescent short arm of chromosome 13 (P = 0.458) and the bright fluorescent marker close to the centromere on chromosome 3 (P = 0.426).The polymorphism pattern was found to be different between the maternal (blood culture) and fetal (amniotic fluid cell culture) karyotypes in each of the 25 paired cases studied . This technique is valuable in prenatal diagnosis to exclude possible maternal cell contamination and outgrowth in cases where the amniotic fluid cell cultures reveal a female karyotype.

Cancer Res, 1977 Apr, 37(4), 1227 - 31
Nucleic acid content and nuclear chromatin structure of human bladder cell culture lines as studied by flow cytofluorometry; Melamed MR et al.; Two human bladder cell lines, T-24 and HCV-29, are studied with flow cytofluorometry and acridine orange staining to determine relative DNA and RNA content per cell and to measure resistance to thermal denaturation of DNA in situ . The RNA/DNA ratio for HCV-29 is over twofold higher than that for T-24, a difference that is consistent with the differences in cytological morphology and staining characteristics of these two cell lines and is sufficient to distinguish them completely, although measurements of DNA or RNA alone may not . In addition, the two cell lines show differences in DNA "melting" curves that indicate structural or conformational differences in nuclear chromatin . It is evident that the features are related to nuclear and cellular morphology, and they may be of value as additional parameters for characterizing tissue culture cell lines.

Am J Clin Pathol, 1977 Apr, 67(4), 397 - 400
Comparative sensitivities of viruses to cell cultures and transport media; Rutala WA et al.; The relative sensitivities and temporal permissivenesses of human embryonic kidney, baboon kidney, and human fibroblast (WI-38) cells for primary isolation of viruses were compared . Of 405 viruses isolated, 83% (335) were cultivated in human embryonic kidney cells, and 49% (198) in baboon kidney cells . WI-38 cells supported the growth of 34% of 199 viral agents . Of the 405 isolates, 70% manifested a cytopathic effect first in human embryonic kidney cells . Daily cumulative rates for primary virus isolation from 1960 to 1974 were examined . Of 558 virus isolates, 58% showed cytopathic effects within seven days after inoculation of the specimen . Comparison of two transport media demonstrated that the total number of isolates from tryptic soy broth approximated twice the number detected with charcoal viral transport medium.

Xenobiotica, 1977 Apr, 7(4), 221 - 33
Metabolism and cytotoxicity of 7,12-dimethylbenz{a}anthracene by hamster, rat and rabbit embryo cell cultures; Gentil A et al.; 1 . The metabolism of 7,12-dimethylbenz{a}anthracene (DMBA) by rat, hamster and rabbit fibroblasts has been studied and compared with the metabolism of the hydrocarbon by liver homogenates . The metabolsim of DMBA by cell cultures and by liver homogenates was very similar . The ethyl acetate-soluble metabolites identified included dihydrodiols, phenols and hydroxymethyl derivatives . Other more polar metabolites and unidentified water-soluble metabolites were also formed . 2 . High yields of phenols and other more polar metabolites, which may be tetrahydrotetrols, were produced by rabbit fibroblasts . 3 . Kinetic studies showed that the metabolic activity of rabbit fibroblasts was high but that the conversion of DMBA into water-soluble metabolites was lower than with hamster and rat fibroblasts . 4 . 7,12-Dimethylbenz{a}anthracene-induced cytotoxicity was inversely related to the conversion of metabolized DMBA to water-soluble derivatives.

Virologie, 1977 Apr-Jun, 28(2), 103 - 9
Activity of lactate dehydrogenase, acid and alkaline phosphatases in measles virus-infected monkey kidney cell cultures; Esanu V et al.; The influence of wild (Co-69) and attenuated (L-16) measles virus infection on the activity and activation energy of lactate dehydrogenase (LDH), acid and alkaline phosphatases (P-ase) was tested in R9CA monkey kidney cells at various time intervals after inoculation . With both virus strains significant changes in enzymatic activity occurred especially within the first 24 hours post inoculation . The two stains have a different influence on alkaline P-ase activity variation, which might therefore be used as a differentiation marker . Variations in LDH activation energy might be an early indicator of virus infection . LDH activity is significantly higher in cellular homogenates diluted 1:10, the dilution effect being more obvious in infected cells after a longer time interval post inoculation.

Biomedicine, 1977 Apr, 27(3), 116 - 9
In vitro synthesis of alpha-1-antitrypsin in long term monolayer human liver cell cultures; Gautier M et al.; Explants for long term monolayer liver cell cultures were taken from individuals having PiM or PiZ phenotypes . Radioactive labelling, using I125 and an original method, permitted the quantitative measurement of AAT in vitro and more important, allowed Pi phenotype determination.

Science, 1977 Mar 25, 195(4284), 1345 - 8
Enzyme polymorphisms as genetic signatures in human cell cultures; O'Brien SU et al.; The electrophoretic resolution of seven relatively polymorphic human gene-enzyme systems expressed in tissue culture cells can be used as a sensitive genetic monitor for intraspecific cell contamination . An identical genotype at each of the same allozyme loci provides a 95% (or greater) confindence estimate of the identity of two cultured lines, on the basis of the allelic frequencies of the seven enzyme loci in natural populations and in populations of independently derived cultured cells . Of 27 commonly used human cell lines examined, only one of 351 pairwise comparisons proved genetically indistinguishable.

Science, 1977 Mar 25, 195(4284), 1343 - 4
Inter- and intraspecies contamination of human breast tumor cell lines HBC and BrCa5 and other cell cultures; Nelson-Rees WA et al.; It is shown that the two most recently reported cell lines derived from malignant human breast tissue, HBC and BrCa5 are, respectively, rat and HeLa cell contaminants . The incidence of inter- and intraspecies contamination among 279 cell cultures from 45 laboratories in an 18-month survey is also presented.

Eur J Biochem, 1977 Mar 15, 74(1), 7 - 12
Prostaglandin production by normal and transformed 3T3 fibroblasts in cell culture; Hammarstrom S; Prostaglandin E2 and prostaglandin F2alpha were quantitatively determined in culture media from Balb/c 3T3 fibroblasts and two virus-transformed derivatives of these cells . Regular and (simian virus 40)-transformed 3T3 cells produced low and almost identical prostaglandin E2 concentrations . The levels were maximal (10 ng/ml) 24 h after planting and decreased during the next 96 h to 2.5 ng/ml . In contrast, polyoma-virus-transformed 3T3 cells produced prostaglandin E2 continuously for 120 h, giving a final concentration of 270 ng/ml . Fresh medium supplemented with calf serum reinitiated prostaglandin production in confluent 3T3 cells . Maximal prostaglandin E2 concentrations were obtained between 6 and 18 h after medium change and were proportional to the serum concentration of the medium . Indomethacin (10(-6) M) completely inhibited prostaglandin E2 production but not prostaglandin F2alpha production by these cells.

Cancer Treat Rep, 1977 Mar-Apr, 61(2), 147 - 51
Characteristics of human prostatic cell cultures; Kaighn ME; In preliminary experiments, the respective requirements of prostate-derived epithelial cells were compared with those of human lung fibroblast line (WI38) . Optimal levels for cysteine and glutamine were similar but not identical . The response of these two cell types to the macromolecular fraction of serum (dialyzed) was reciprocal . These results suggest that serum contains a dialyzable factor or factors necessary for the growth of prostatic epithelial cells.

Chem Biol Interact, 1977 Mar, 16(3), 251 - 64
Retinyl acetate modulation of cell growth kinetics and carcinogen--cellular interaction in mouse epidermal cell cultures; Yuspa SH et al.; Exposure of mouse epidermal cell cultures to beta-retinyl acetate (RA) affects a number of parameters presumed to be important in chemical carcinogenesis . (1) RA alters the course of differentiation of the epidermal cells in culture resulting in a reduced rate of cell death which normally follows cellular maturation during the first two weeks in culture . The extended life span of the cultures appeared due to prolonged survival of cells and not to increased growth rate since RA inhibited the rate of cellular proliferation . This inhibition took place only after completion of a full cell cycle in the presence of RA . (2) DNA repair in response to physical and chemical agents was quantitatively unaffected in the presence of RA . (3) The activity of constitutive aryl hydrocarbon hydroxylase (AHH) was slightly decreased after exposure to RA but the level of enzyme induced by benz{a}anthracene was strongly reduced to 20% of the controls . (4) In the presence of RA, binding of 7,12-dimethylbenz{a}anthracene to epidermal cell DNA was markedly decreased . In contrast, binding to cellular protein was significantly increased by the retinoid.

J Natl Cancer Inst, 1977 Mar, 58(3), 771 - 5
The Gardner syndrome: a family study in cell culture; Danes BS et al.; The occurrence of tetraploidy was studied in skin cultures containing both epitheloid and fibroblastic cells derived from 137 members (28 clinically affected, 50 normals at risk and 59 normals not at risk) of 6 families with the Gardner syndrome (3 classical, 3 variant) . The cultures from all 28 affected members showed increased tetraploidy . Among the 50 normal members at risk for inheriting the Gardner gene, the cultures from 19 had increased tetraploidy and those from 31 did not . Cultures from 56 of the 59 family members not at risk did not show increased tetraploidy . Although the families were divided into subgroups (classical and variant) on clinical phenotypes, no such subdivision could be made on the basis of increased tetraploidy in skin cultures.

Somatic Cell Genet, 1977 Mar, 3(2), 149 - 55
Microcarrier cell culture: new methods for research-scale application; Levine DW et al.; A positive-charge-carrying, dextran microsphere has been developed which serves as an excellent surface for the attachment and growth of anchorage-dependent cells in microcarrier culture . With standard cell culture media, saturation cell concentrations in excess of 4 X 10(6) cells/ml are routinely obtained for secondary chicken embryo fibroblasts or normal diploid human fibroblasts . The use of microcarriers reduces the time, expense, and apparatus complexity required for the routine propagation of anchorage-dependent cells.

Tsitologiia, 1977 Mar, 19(3), 338 - 44
{Dynamics of 3H-thymidine and 3H-deoxycytidine incorporation into the nuclei of a rabbit kidney cell culture during the S period}; Gunderina LI; Using a combined cytophotometric-autoradiographic method a study was made of 3H-thymidine and 3H-deoxycytidine incorporation rates into the interphase nuclei of rabbit kidney cell culture during the S-period . The rate of 3H-deoxycytidine (10(-4) M--10(-6) M) incorporation into nuclei increases throughout the first part of the S-period and decreases from its middle to the end . The patterns of variations of 3H-thymidine and 3H-deoxycytidine incorporation rates into the nuclei of cultured rabbit kidney cells during the S-period were identical.

J Pharm Sci, 1977 Mar, 66(3), 386 - 8
Potency of synthetic luteinizing hormone releasing hormone preparations in rat anterior pituitary cell cultures; Dermody WC et al.; Selected synthetic luteinizing hormone releasing hormone preparations were assayed, and their potencies were determined relative to one sample utilizing primary cultures of enzymatically dispersed rat anterior pituitary cells . Preliminary cell culture experiments indicated that luteinizing hormone releasing hormone had to be in constant contact with cells for continued luteinizing hormone secretion . Luteinizing hormone levels in media reached a maximum concentration after 4 hr of continuous luteinizing hormone releasing hormone exposure . Cell culture bioassay was selected over the bioassay employing chronically ovariectomized steroid-blocked rats due to greater sensitivity and economy . The assay of each luteinizing hormone releasing hormone preparation was replicated four to seven times . Preparations from several companies were less potent (p less than 0.05) than the reference product . Contaminants were disclosed by TLC in preparations with potencies lower than the reference product.

J Exp Med, 1977 Mar 1, 145(3), 693 - 708
Generation of T-helper cells in vitro . II . Analysis of supernates derived from T-helper cell cultures; McDougal JS et al.; Supernates derived from in vitro generated T-helper cells have been analyzed for their capacity to substitute for T-cell carrier reactivity . T-helper cell supernates stimulate both a carrier-specific and nonspecific anti-DNP-PFC response to DNP-carrier conjugates in cultures of hapten-primed spleen cells . The carrier-specific and nonspecific activity can be distinguished by dosage optimum, antigen requirements, binding specificity for carrier, and in the requirement for additional splenic adherent accessory cell involvement . The active factors produced in this system are heat labile and sensitive to trypsin and periodate . They are removed by absorption with alloantisera directed toward the strain from which the supernate was derived but not by a variety of anti-immunoglobulin sera.

Chem Biol Interact, 1977 Mar, 16(3), 309 - 14
Comparison of the photochemical and enzymic generation of excited states of oxygen on the induction of benzo(alpha)pyrene mono-oxygenase in liver cell cultures; Paine AJ; The photochemical generation of excited states of oxygen such as the superoxide ion(O-2) and singlet oxygen (1o2) by the mild illumination of culture medium containing riboflavin induces benzo(alpha)pyrene mono-oxygenase in 3 different cell lines derived from rat liver . Similar rates of O-2 generation can be produced by the action of xanthine oxidase on xanthine yet this system does not induce the mono-oxygenase . This result confirms that the mono-oxygenase induction is not mediated by O-2 is not mediated by O-2 and that 1O2 is the most likely candidate for stimulating the mono-oxygenase activity.

J Cell Physiol, 1977 Mar, 90(3), 387 - 405
Comparative studies of glucose-fed and glucose-starved hamster cell cultures: responses in galactose metabolism; Christopher CW et al.; The metabolic flow of trace amounts of D-{14C}-galactose was followed in cultures of transformed and untransformed hamster cells over a period ranging from five minutes to two hours . The results of chromatographic and enzymatic analyses of the soluble pools are described . Non-glycolytic cells(previously deprived of sugar periods of up to 24 hours) convert D-galactose to galactose-1-phosphate and uridine diphosphoglucuronic acid in 10 to 20 minutes . In the same short assay time, glycolytic cells which have been maintained for 24 hours in media containing glucose or galactose convert D-galactose to uridine diphsphogalactose and uridine diphosphoglucose (ratio 1.4:1) . Long term diprivation of sugar also results in 3- to 4-fold increases in the uptake of galactose . In addition, the incorporation of galactose label into chloroformethanol soluble material appears to be influenced by the culture conditions of the untransformed cells while incorporation in the transformed cells appears unaffected . When cycloheximide is included in the maintenance medium for extended periods, the non-glycolytic cells also show increases in galactose uptake rates but the glucose-fed, glycolytic cells llose uptake ability . UDPhexose is the main galactose metabolic peak in the soluble pools of the cycloheximide-treated, glycolytic and the cycloheximide-treated, non-glycolytic cells . The results of these experiments suggests that uptake of galactose and its subsequent metabolism are under separate control.

Biull Eksp Biol Med, 1977 Mar, 83(3), 350 - 3
{Cell cultures obtained using collalytin from the pancreases of cattle fetuses}; Babikova RA et al.; The authors present morphological characteristics of primary monolayer cultures prepared from the pancreas of bovine fetuses . Combined treatment with trypsin and collalytine solutions (a preparation with collagenase activity) was used for dispersion of the tissue of the pancreas . Numerous epithelial cells corresponding by morphofunctional characteristics to beta-cells of the islets of Langerhans were contained in be cultures obtained; an aldehyde-fuchsin-positive granularity was revealed in the cytoplasm of these cells . Degranulation of these cells occurred under the effect of an increased glucose concentration in the nutrient medium.

Blut, 1977 Mar, 34(3), 227 - 36
Establishment of peripheral lymphoid cell cultures from patients with Hodgkin's disease depending on Epstein-Barr-Virus-reactivity and cellular immunity; Diehl V et al.; Peripheral blood lymphocytes from 43 patients with Hodgkin's disease were studied for spontaneous growth in longterm cultures in vitro . The rate of culture establishment in Hodgkin's patients was dependant on a positive Epstein-Barr-Virus (EBV)-seroreactivity and intact delayed hypersensitivity reaction to tuberculin . Localized and inactive disease, as well as the absence of atypical mononuclear cells in the peripheral blood had a favourable influence on the longterm in vitro growth . The overall establishment rate in Hodgkin patients was 18 out of 60 attempts (30%), 16 out of 34 (47%) in patients without treatment, only 2 out of 26 (7.7%) attempts during treatment . These results were compared with culture attempts of peripheral blood cells from healthy individuals and umbilical cord blood lymphocytes . Only 12 out of 60 attempts in healthy donors (18.2%) and 0 out of 49 attempts with umbilical cord blood lymphocytes were successful.

Cancer Lett, 1977 Mar, 2(4-5), 285 - 9
Comparison of the biological activity of the tumor promotor phorbol myristate acetate and a metabolite, phorbolol myristate acetate, in the cell culture; Sivak A; Phorbolol myristate acetate, a metabolite of the tumor promotor phorbol muristate acetate in mouse skin, has one-fiftieth the potency of the parent molecule for the induction of cell division in stationary cultures of BALB/c-3T3 mouse embryo cells . Similarly, in a mixed cell culture assay devised for detection of tumor-promoting agents, phorbolol myristate acetate exhibited only a small fraction of the activity of unmetabolized phorbol ester . The results indicate that the biological activity of phorbol esters either does not require metabolic conversion or is converted by the cells used in this system and that phorbolol myristate acetate would be a tumor promotor of low potency for mouse skin compared to phorbol myristate acetate.

Acta Virol, 1977 Mar, 21(2), 161 - 4
Biological characteristic of Nigerian strains of West Nile virus in mice and cell cultures; Odelola HA et al.; The biological characteristic in mice and cell cultures of 7 strains of West Nile (WN) virus isolated in Nigeria were studied . The pattern of virus development in most organs of mice infected with two of the seven strains tested was identical, while it varied with the remaining five strains . All 7 strains of WN virus multiplied with a cytopathic effect (CPE) in the four cell cultures examined.

Biochim Biophys Acta, 1977 Feb 28, 496(2), 384 - 400
Plasminogen activator from human embryonic kidney cell cultures . Evidence for a proactivator; Nolan C et al.; The nature of the trypsin-activatable plasminogen activator produced by kidney cell cultures (Bernik, M.B (1973), J . Clin . Invest . 52, 823-834) was investigated using human embryonic kidney (HEK) cell cultures in serum-free medium . Plaminogen activator activity ratios (trypsin-activated/ untreated controls) in HEK cell-conditioned media were maximal (up to 3) during the first week of culture and remained nearly constant at approximatley 2 for the next 3-5 weeks, while the total plasminogen activator titer increased in a nearly linear manner . Therefore, coincident with progressive cell degeneration and death, the ratios decreased to near unity due to "spontaneous" activation of the enzyme, which was inhibited in cell-free conditioned media by the pancreatic trypsin inhibitor Kunitz and benzamidine . Since the activator is not inhibited by the trypsin inhibitor, it is concluded that a protease other than the plasminogen activator is responsible for the activation . Increases in the plasminogen activator titers (about 2-fold) were similarly obtained by culturing the cells in medium containing low concentrations (0.05-0.10 mug/ml) of trypsin for up to about 6 weeks . The presence of the trypsin inhibitor in HEK cells cultures decreased the rate of activation, resulting in higher activity ratios (up to 6), and the total plasminogen activator activity was reduced only minimally (less than 20%), if at all, by the highest concentration of the trypsin inhibitor (100 mug/ml) tested . Affinity chromatography of conditioned media with activity ratios of 1.6--2 separated the plasminogen activator into an active fraction and a fraction which was activated a minimum of 200-fold by trypsin and contained no measurable activity prior to activation . Gel filtration of crude conditioned media or partially purified activator separated the plasminogen activator into two peaks; both were trypsin-activatable, and their relative proportions varied with the isolated conditions . The results indicate the occurrence of a proenzyme form of the plasminogen activator in the culture media.

J Protozool, 1977 Feb, 24(1), 172 - 6
Eimeria dispersa and Eimeria gallopavonis: infectivity, survival, and development in primary chicken and turkey kidney cell cultures; Doran DJ et al.; Eimeria dispersa (turkey strain) and Eimeria gallopavonis sporozoites were inoculated into primary cultures of chicken kidney (CK) and turkey kidney (TK) cells . Eimeria dispersa sporozoites were more infective in either cell type than those of E . gallopavonis: at 4 hr, the percentage of infection was 67-98 for E . dispersa but only 23-56 for E . gallopavonis . E . dispersa also survived better in culture: at 2 days, losses of E . dispersa in both cell types were only 4-19%, whereas losses of E . gallopavonis were 35-47% IN TK cells and 60-95% CK cells . However, E . gallopavonis developed further than E . dispersa . Location and increase in numbers of intracellular stages at 4 days indicated that E . dispersa proceeded through 2 schizogonic generations before development stopped.

Clin Genet, 1977 Feb, 11(2), 83 - 90
Cystic fibrosis: Evidence for a genetic compound from a family study in cell culture; Danes BS et al.; Although the majority of patients with cystic fibrosis (CF) show a typical clinical course, a minority with the same clinical phenotype at the time of initial diagnosis have an atypical (mild) course . Skin fibroblast cultures were established from 49 members of the family of one such atypical CF adult patient, previously identified (Danes et al . 1976) as CF Class II (ametachromatic and no metabolic cooperation with CF Class I fibroblasts), the offspring of Class I (metachromatic, metabolic cooperation with normal fibroblasts)/Class II mating . The culture phenotype for Class I was traced on the maternal side and for Class II on the paternal side through consecutive generations and the culture phenotype of each class segregated . This family study added experimental evidence to support the hypothesis that the atypical (mild) clinical features and course of this adult CF patient were due to two different CF genes combining to produce a genetic compound expressing a mild form of CF.

Cell, 1977 Feb, 10(2), 265 - 73
Messenger RNA for myosin polypeptides: isolation from single myogenic cell cultures; Strohman RC et al.; Messenger RNA which stimilates the synthesis of myosin heavy chain in a reticulocyte lysate has been isolated from single myogenic cell cultures . Specific myosin polypeptides have been identified by immunoprecipitation with an antibody made to purified adult chicken skeletal muscle myosin . This mRNA binds to oligo(dT)-cellulose, and an active fraction from sucrose gradients migrates as 26S on formamide-polyacrylamide gels . The relative amount of this RNA increases dramatically at the time of terminal differentiation.

Cancer Res, 1977 Feb, 37(2), 585 - 94
Combined growth-inhibitory responses and ultrastructural alterations produced by 1,3-bis(2-chloroethyl)-1-nitrosourea and dexamethasone in rat glioma cell cultures; Grasso RJ et al.; The effect of 0.0001 to 10 muM 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and 1 muM dexamethasone on cell proliferation was studied by measuring cell densities in control and drug-treated rat glioma (strain C6) monolayer cultures . When C6 cultures were exposed to 0.01 to 10 muM BCNU, the growth rates decreased for 2 days as control cell populations continued to proliferate at log phase rates . These growth-inhibitory responses were dose dependent and ranged from 20 to 80%, relative to control growth . Subsequently, the growth rates increased and the inhibitory responses ranged from 0 to 12% 4 days later . Cell densities in C6 cultures exposed to 1 muM dexamethasone for 1 day did not differ significantly from controls . Then cell proliferation ceased and the inhibitory response remained at 50% relative to controls in stationary phase . When 0.03 muM BCNU and 1 muM dexamethasone were supplied simultaneously to C6 cultures, a 35% inhibitory response occurred after 1 day . This response did not differ significantly from that observed with 0.03 muM BCNU alone . After 4 days, the inhibitory response did not decrease in cultures containing both drugs, but did decrease to 13% in the 0.03 muM BCNU-treated cultures . In 1 muM BCNU-treated cultures, the response was 66% after 1 day, which decreased to 21% 5 days later . When 1 muM BCNU was supplied to C6 cultures that were pretreated for 1 day with 1 muM dexamethasone, the response was 91% the following day, and this decreased to only 54% 5 days later . Dose-response curves showed that the inhibitory responses after 1 day in these pretreated cultures exposed to 0.001 to 10 muM BCNU increased up to 22% relative to the responses produced by either drug alone . After 5 days, the responses in the pretreated cultures exposed to 0.001 to 1 muM BCNU was 50%, which was similar to the response produced by 1 muM dexamethasone alone . Ultrastructural studies revealed that control and 1 muM BCNU-treated C6 cells contained 18 mitochondria, but the treated cells were 10% smaller after 1 day . Cells exposed to 1 muM dexamethasone for 1 day conount of granular endoplasmic reticulum increased greater than 80% in cells treated with BCNU for 1 day or dexamethasone for 2 days . C6 cells pretreated with dexamethasone and exposed to BCNU for an additional day (a) contained 23 mitochondria, (b) did not decrease in size, and (c) exhibited a greater than 250% increase in the amount of granular endoplasmic reticulum . These results demonstrate that combined growth-inhibitory responses and ultrastructural alterations occur when C6 cells are treated sequentially with 1 muM dexamethasone and BCNU.

J Med Microbiol, 1977 Feb, 10(1), 121 - 5
Diagnosis of rotavirus infection by cell culture; Bryden AS et al.; Rotaviruses were detected by electronmicroscopy in 35 of 84 specimens of faeces from infants with diarrhoea, and in 31 by fluorescent staining of tissue cultures infected with help of centrifugation . LLC-MK2 cells were found to be the most sensitive, although primary and secondary human-embryo-kidney and primary calf-kidney cells could also be used . A micromodification of the tissue-culture method provides a relatively simple technique for the diagnosis of rotavirus infection, for the titration of virus infectivity and for estimating neutralising antibodies in serum.

J Clin Microbiol, 1977 Feb, 5(2), 202 - 7
Demonstration of dual rhinovirus infection in humans by isolation of different serotypes in human heteroploid (HeLa) and human diploid fibroblast cell cultures; Cooney MK et al.; The ability to isolate rhinoviruses in human heteroploid cell cultures was investigated by inoculating HeLa cells (HeLa M) with specimens previously shown to be positive in human diploid cell cultures . The 135 positive specimens selected were representative of 22 different rhinovirus types, and 4 to 9 specimens were available for each serotype . Specimens were inoculated into human diploid fetal tonsil fibroblasts (FT), HeLa cells with 30 mM Mg2+, and HeLa cells without increased Mg2+ . One hundred twelve rhinovirus strains (83%) were reisolated in FT cells, whereas 76 rhinovirus strains (56%) were recovered in HeLa cells with 30 mM Mg2+ . All strains recovered in FT were the same serotype as that originally recovered in diploid cells, but five of the HeLa cell isolates (3.7% of total specimens) were different serotypes, indicating dual rhinovirus infections . Four rhinovirus serotypes, (3, 42, 48, and 70) were recovered in HeLa but not in diploid cells; these serotypes were rare in our previous studies . Isolation of rhinovirus in FT cells was usually accomplished at first passage, whereas rhinovirus cytopathic effects in HeLa cells were not observed at first passage, but required one, two, or (rarely) three blind passages . Only 28 rhinoviruses (21%) were recovered in HeLa cells without increased Mg2+; however, three serotypes, types 16, 36, and 58, were recovered as effectively in HeLa cells, with or without added Mg2+, as they were in FT cells . In general, rhinoviruses were less efficiently recovered in HeLa cells; however, certain serotypes may be detected better by HeLa cells.

Eur J Pediatr, 1977 Jan 26, 124(2), 101 - 11
Progeria: a cell culture study and clinical report of familial incidence; Rautenstrauch T et al.; This report relates the case histories of two sisters who demonstrated the typical symptoms of progeria at birth . One of these children had died previous to this study . The familial occurrence underlines the thesis that progeria is an autosomal-recessive disorder . The examination of the cultured skin fibroblasts from the younger child showed a clear decrease in cell growth . On the other hand, the immunfluorescent examination of skin biopsies and cultured skin fibroblasts revealed no atypical distribution of collagen types.

J Biol Chem, 1977 Jan 10, 252(1), 219 - 23
Cobalt regulation of heme synthesis and degradation in avian embryo liver cell culture; Maines MD et al.; Inorganic cobalt was found to induce heme oxygenase activity in primary cultures of embryonic chick liver cells and to inhibit the induction of delta-aminolevulinate synthetase by the porphyrinogenic compounds allylisopropylacetamide, dicarbethoxy-1,4-dihydrocollidine, etiocholanolone, phenobarbital, Aroclor (R)1254, and secobarbital . Much smaller concentrations of Co2+ (5 muM) were required to inhibit delta-aminolevulinate synthetase than to induce heme oxygenase activity (50 muM) . These effects of Co2+ on heme synthesis and heme degradation were potentiated by depletion of cellular glutathione content as a result of treatment with diethyl maleate . Cobalt inhibition of the induction of delta-aminolevulinate synthetase was of the same magnitude and probably involved the same mechanism as that produced by cobalt heme dimethyl ester and iron heme . The induction of heme oxygenase by cobalt could be blocked by cycloheximide . Plasma protein synthesis was not inhibited in the presence of concentrations of Co2+ which produced inhibition of delta-aminolevulinate synthetase or induction of heme oxygenase . Other metals such as Cd2+ and Cu2+ also inhibited the induction of delta-aminolevulinate synthetase by allylisopropylacetamide . These findings indicate that Co2+ can regulate heme metabolism directly in liver cells without intermediate actions on extrahepatic tissues . It is suggested that regulation of production of delta-aminolevulinate synthetase and heme oxygenase is mediated through the action of the metal ion rather than the metal in the form of a tetrapyrrole chelate.

Prog Clin Biol Res, 1977, 15, 251 - 7
Factors influencing monolayer cell culture morphology and survival of cerebellar granule cells from wild-type and mutant mice; Messer A; A distinction must be made between genetic factors intrinsic and extrinsic to a specific degenerating cell type if neurological mutants that show such effects are to be used to assess cause-and-effect correlations of neural development . When the growth of granule cells from cerebella of staggerer mutant mice is investigated in monolayer cell cultures using modified Hams F12 medium plus fetal calf serum, cells from the mutant are found to clump less and survive longer than their wild-type counterparts . Thus, the degeneration of granule cells observed in these mutants in vivo cannot be a function of irreversibly programmed cell death before postnatal day 7, the age at which cells are dissociated . The possibility that the increased survival is simply a function of initial cell-cell interactions is examined by comparing normal cells grown on glass, plastic, or polylysine-coated glass to each other, and then comparing the behavior of staggerer vs control cells under the same conditions . Although the polylysine coating both reduces the amount of initial clumping and increases the survival of normal cells, it does not completely eliminate the difference between mutant and control . Mutant and control cultures exhibit the same behavior only when culture conditions are changed to include supplementation with horse serum instead of fetal calf serum in addition to the substrate coating.

Exp Pathol (Jena), 1977, 13(4-5), 275 - 9
Scanning electron microscopic studies on untreated and transformed mouse embryo fibroblast cell cultures; Ferencz G et al.; Cultures of CBA T6T6 mouse embryo cells were transformed by 20-methylcholanthrene (MC) treatment in vitro . Untreated and MC treated cells and reexplanted cells of tumours originating from MC treated cells were compared by scanning electron microscopy (SEM) . The 3 cultures showed considerable differences in the situation of the cells compared to each other, as well as in the number and shape of the surface formations.

Arch Virol, 1977, 54(3), 177 - 87
The kinetics of adenovirus infection and spread in cell cultures infected with low multiplicity; Wigand R et al.; The cause for the long "incubation period" required till the appearance of the CPE in cell cultures inoculated with small amounts of adenovirus was investigated with adenovirus type 5 in HeLa cell cultures . The spread of virus in a culture from cell to cell is minimal, as shown in cultures with antiserum in the medium . The spread by spontaneously released virus via the medium is more important . It can be accelerated by repeated subcultivation after freezing and thawing the cells in 2 or 3 days' intervals . The quantity of virus produced by one infected HeLa cell was found to be 200 TCID50 within 48 hours, independent of the MOI . The growth cycle too is largely independent of the virus dose . The data suggest that the long duration of the "incubation period" is fully explained by a burst size of 200, a cycle length of 40 to 48 hours and the assumption of a slow and steadily working process of spontaneous release of virus into the medium . Some other possible causes, like impurities in the inoculum or slow and asynchronous early stages of infection, have been ruled out by appropriate experiments.

Adv Exp Med Biol, 1977, 79, 397 - 412
The biosynthesis of elastin by an aortic medial cell culture; Abraham PA et al.; A long term culture of aortic medial cells, derived from newborn pig aorta, has been established . The ability of these cells to synthesize soluble elastin has been demonstrated by isolation and characterization of the radioactively labeled protein, using soluble elastin of copper-deficient pig aorta as the carrier . The synthesis of corsslinked elastin was shown by the isolation and identification of the lysine-derived crosslinks after incubating the cultures with {14C}-labeled lysine . The precursor relationship of soluble to insoluble elastin was demonstrated by incubating the {3H}-labeled soluble elastin from copper-deficient pig aorta with the culture and isolating labeled crosslinks from the insoluble elastin residue.

Gerontology, 1977, 23(4), 245 - 55
The establishment of criteria for "quiescence" in ageing human embryo cell cultures and their response to a proliferative stimulus; Hill BT; Experimental observations have shown that late passage cultured cells have a different growth pattern from early passage cells . For a meaningful comparison of the response of "quiescent" ageing cells to a proliferative stimulus it was, therefore, necessary to use cells in comparable states of "quiescence" . Criteria have been established for defining quiescence in ageing cells which include alterations in cell number, ability to transport non-metabolizable substrates and inability to incorporate 3H-thymidine . Using cells of different ages in comparable quiescent states, it has been shown that a smaller proportion of older cells reacted to a proliferative stimulus, and the time taken to respond was longer.

Ann Anat Pathol (Paris), 1977, 22(4), 349 - 59
{Neuroblastoma: contribution of biochemistry and cell culture to the diagnosis of an undifferentiated form}; Scheiner MC et al.; An apparently anaplastic retroperitoneal tumour was studied by a cell culture method, The patient was a young man . The method used revealed the morphological features and secretory potential of the lesion, which could thus be diagnosed as an immature neuroblastoma.

Biol Neonate, 1977, 32(5-6), 310 - 8
Effects of testosterone and estradiol on ratios of adult to fetal hemoglobin in cell cultures of human fetal liver; Congote LF et al.; The effects of testosterone and 17beta-estradiol on the synthesis of fetal and adult hemoglobins have been studied using a short-term primary cell culture system of human fetal liver at midgestation . There was a significant 23% increase in incorporation of 59Fe into adult hemoglobin relative to the total after the addition of 5 X 10(-8)M testosterone . 17beta-Estradiol (10(-6)M) lowered the incorporation of 59Fe by 21% . beta-Globin chain synthesis, measured as 3H- or 14C-leucine incorporation into globin chains, was identical in control and testosterone-treated cells and only slightly lower when 17beta-estradiol was added . For this reason the observed changes in adult hemoglobin resulting from the action of testosterone and 17beta-estradiol are caused by an indirect effect either in the final hemoglobin assembly or by small changes in the gamma/alpha-chain ratio which may be undetected by the methodology used.

In Vitro, 1977, 13(12), 809 - 17
Rat hepatocyte primary cell cultures . III . Improved dissociation and attachment techniques and the enhancement of survival by culture medium; Williams GM et al.; The conditions for obtaining representative, adult rat hepatocyte primary cell cultures were improved such that viable yields of 50% of the liver were produced which gave rise to cultures representing 30% of the liver . The survival of these cultures in various media was compared revealing that in complex media, particularly containing galactose, survival was improved.

Arzneimittelforschung, 1977, 27(8), 1534 - 46
{Effect of a benzopyrone compound on embryonic tissue and cell cultures (author's transl)}; Lipp R; Embryonic tissues and cells of the chicken were treated with a coumarin-rutin derivative preparation (Venalot) . A total of 3000 cultures from embryonic epithelia, skeletal muscle tissue, and connective tissues were tested . At high dosages, never administered in the therapy, the preparation inhibited the cell proliferation strongly . With the diminution to therapeutical concentrations no longer inhibitory but stimulatory effects, viz . to mitosis, were revealed . High cell partition rates in the connective tissue (fibroblasts), in the epithelial cells and in the bony tissue of the embryonic os frontale (osteoblasts) are an indication of the mechanism of the known wound-healing accelerating action of the preparation . The effect of stimulating the proteolytic action in mesenchymal cells, observed on isolated peritoneal macrophages has been confirmed for the mesenchymal cell of the embryonic chicken.

Biull Eksp Biol Med, 1977 Jan, 83(1), 88 - 91
{Comparative characteristics of endometrial and endometriosis cell cultures}; Strizhakov AN et al.; The authors studied comparatively the endometrium and endometrosis cell cultures of 35 women before and (in part of the group) after the synthetic progestin treatment . Methods for cultivating the endometrium and endometriosis cells were developed . A normal endometrium cell culture was found to be made up by epithelioid cells, while the cell culture from the endometriosis focus exhibited mostly a mixed cell population . The analysis of the internal endometriosis cell cultures before and after the infecundin treatment failed to show any clear distinction in respect to the cell growth and morphology . Endometriosis cells were found to possess low mitotic activity which made the kariotype studies difficult . the data obtained are the result of the first effort to cultivate endometriosis cells.

Tsitologiia, 1977, 19(12), 1384 - 6
{Controlled cell culture . I . A modified perfusion chamber}; Lezhnev EI et al.; The construction of a modified perfusion chamber is presented, which can be used for a prolonged cultivation of mammalian cells and tissues, for observation of the behavior of living cells as well as for the study of different effects on these cells . The chamber is made as non-demountable of optical glass, with a diffusive barrier separating the pericellular zone from that with a perfusion medium . The scheme of the equipment for cultivation of cells and tissues in this diffusion chamber on controlling the composition of nutrient medium and gas phase is given.

Ontogenez, 1977, 8(4), 383 - 8
{In vitro cell culture of the Ararat cochineal insect, Porphyrophora hamelii Brandt}; Magakian IuA et al.; The possibility of cultivating the Ararat cochineal cells in the nutrient media developed for cell cultures of the other insect species was investigated . The initial cochineal cell culture was obtained in suspension . The cell culture on the substrate (glass) dies within 7 days . 2 peaks of proliferative activity was observed in the suspension culture . The increase of cell ploidy and their death were found between these two peaks . The small cells survived and kept their capacity for proliferation . The hemolymph did not stimulate cell proliferation but enabled their better attachment to the substrate . The use of different media did not reveal marked differences in cell behaviour . The pigment granules disappeared during the first week of cultivation.

Nucleic Acids Res, 1977, 4(5), 1267 - 71
Detection of a contaminant cell culture line by restriction endonuclease cleavage patterns of mitochondrial DNA; Grossman LI et al.; A putative HeLa cell culture line was discovered to be contaminated with mouse cells by examination of agarose gel profiles of restriction endonuclease digests of mitochondrial DNA . The contamination was confirmed by karyotypic analysis, and by observation of the mouse satellite band in an analytical buoyant density centrifugation of total cellular DNA . Restriction endonuclease analysis of mitochondrial DNA is suggested as a useful method for monitoring the species of cells in culture.

Acta Cytol, 1977 Jan-Feb, 21(1), 162 - 7
Cerebrospinal fluid cytology in patients with brain tumors; a simple method using the cell culture technique; Kajikawa H et al.; A simplified cytologic method using the cell culture technique was employed in 71 cases with brain tumor . Neoplasitc cells were demonstrated in 17 cases (24%), that is in 11 out of 30 cases of glioma, four out of ten cases of metastatic brain tumor, and two out of 17 cases of meningioma . None of 14 other miscellaneous tumors proved positive . Identification of glioma cells could be easily made because they usually showed characteristic morphology and good proliferation in vitro . However, for other types of tumor, conventional methods were considered to be superior to the culture method because their exfoliated cells usually underwent rapid degeneration without showing characteristic morphology during the culture . Some of the illustrative cases were presented.

C R Seances Soc Biol Fil, 1977, 171(5), 1116 - 21
{Effect of differentiation of GABA levels in various cell cultures}; Simler S et al.; The effect of factors inducing somatic differentiation on cellular GABA level has been investigated . C6 glial cells from a rat astrocytoma present a significantly higher GABA level than the other glial or neuronal cells studied . A significant decrease in GABA levels in most cases parallels the somatic differentiation induced either by withdrawal of fetal serum, or by addition of dibutyryl cyclic AMP to the culture medium.

Gegenbaurs Morphol Jahrb, 1977, 123(2), 275 - 86
Enzyme histochemistry of cultured ovarian cells . III . Histochemical characteristics of bovine granulosa and theca interna cells grown separately in cell culture; Stadnicka A; Granulosa and theca interna cells were isolated from bovine preovulatory ovarian follicles . They were cultured separately but in the same conditions of cell culture . Both cell types, grown as monolayers, were investigated histochemically with special regard to the activity of several hydroxysteroid dehydrogenases: delta53betaOH-SDH, 17betaOH-SDH, 20alphaOH-SDH and G6P-DH . Bovine granulosa and theca interna cells during in vitro culture showed high activity of delta53betaOH-SDH and G6P-DH, the enzymes essential to progesterone biosynthesis . Enzyme pattern of cultured cells indicated continuation in vitro of luteinization, which in the normal preovulatory follicle of the bovine ovary begins prior to ovulation . There was investigated as well the influence of single doses of gonadotrophic hormones and estradiol on growth, lipid contents and enzymic activity of cultured in vitro bovine granulosa and theca interna cells.

J Immunol Methods, 1977, 17(1-2), 31 - 8
A rapid microassay for detecting antibodies against poliovirus based on {14C}thymidine uptake of treated cell cultures; Hilfenhaus J et al.; DNA synthesis of mammalian cells propagated in microplates can easily be measured if cell cultures incubated with {14C}thymidine are harvested on the glass fibre filters by a semiautomatic harvesting technique . Soon after infection with poliovirus, {14C}thymidine uptake of U cells (established, human amniotic cell line) is inhibited . This inhibition can be prevented by previous virus neutralization with antibody . Based on this effect a rapid, precise assay method was set up to determine neutralizing antibody titres against poliovirus . There was a good correlation between titres obtained by this assay and those obtained by 50% end point titrations in cytopathogenic effect inhibition assays.

Intervirology, 1977, 8(3), 129 - 44
Isolation of Aleutian disease virus of mink in cell culture; Porter DD et al.; Aleutian disease virus, the causative agent of a persistent infection in mink, was isolated in a continuous line of feline renal cells when the cultures were maintained at reduced temperature (31.8 degrees) . After serial in vitro passage of the virus at this temperature it had an optimum replication temperature of 37 degrees . An immunofluorescence focus assay was found to be suitable for virus quantitation . The cultured virus reproduced Aleutian disease in mink, and the virus could be reisolated from the mink 10--180 days after inoculation . The properties of the virus suggest that it is a member of the parvovirus group.

Prostaglandins, 1977 Jan, 13(1), 41 - 53
Elevation of prostaglandin and cyclic AMP levels by arachidonic acid in primary epithelial cell cultures of C3H mouse mammary tumors; Burstein S et al.; Arachidonic acid causes a sharp transient increase in cyclic AMP levels in primary epithelial cell cultures obtained from C3H mouse mammary tumors . The effect is evident within two minutes and is enhanced by theophylline or 3-isobutyl-1-methylxanthine . Maximum increase in cyclic AMP levels are observed with a dose of 100 mug/ml of arachidonic acid (AA) . At higher dose levels the increase in cyclic AMP levels is reduced . Naproxen, an inhibitor of prostaglandin synthesis in this system markedly reduces the stimulation of cyclic AMP by arachidonic acid but it does not affect the increase in cyclic AMP levels observed after the addition of prostaglandin E's, epinephrine or cholera enterotoxin . Arachidonic acid, under the same conditions, also causes a significant elevation of PGE and PGF media levels which is slower and more sustained than the cAMP response . The data strongly suggest that a metabolic of arachidonic acid is responsible for the cyclic rise, however, it is not certain whether this is due to PGE2 or some other product.

J Neurobiol, 1977 Jan, 8(1), 57 - 65
Neurotrophic control of cyclic nucleotide levels during muscle differentiation in cell culture; Festoff BW; The effects of chick brain-spinal cord extract on morphological development and cyclic nucleotide levels of cultured chick embryo skeletal muscle cells were determined . It had previously been shown that the extract stimulated morphological differentiation, protein synthesis, and choliniesterase activity of muscle cells . Myoblasts fused earlier and an increase in number as well as diameter of myotubes were seen in the extract treated cultures . Cyclic nucleotides levels were higher (almost twice the controls for both adenosine 3',5'-cyclic monophosphate and guanosine 3',5'-cyclic monophosphate) and preceded their occurrence in the control cultures . It was suggested that factor(s) in the extract interact with membrane receptor(s) to alter nucleotide levels which, in turn, allow the effects to be expressed.

Infect Immun, 1977 Jan, 15(1), 204 - 11
Expression of Aleutian mink disease antigen in cell culture; Hahn EC et al.; Infection of CRFK feline kidney cells with Aleutian disease vurus leads to production of virus-induced antigen(s) in the nucleus which could be demonstrated by the fluorescent-antibody technique . The number of fluorescent nuclei was lineraly dependent on the dilution of the inoculum, but rarely exceeded 20% of the cells . Aleutian disease nuclear antigen was only transiently detectable . The virus-induced antigen was detected after infection of cells of several divergent species; however, the CRFK line of feline kidney cells was the most susceptible . Inhibitor studies indicated that deoxyribonucleic acid synthesis, ribonucleic acid synthesis, and protein synthesis were required for viral antigen production . Cell growth was also a requirement for synthesis of viral antigen, An in situ radioimmune assay was used to measure binding of 125I-labeled mink anti-Aleutian disease virus to infected cells and competition with unlabeled sera . The system is suitable for quantitation of infectivity.

Zahn Mund Kieferheilkd Zentralbl, 1977, 65(8), 863 - 6
{A new method for the determination of tissue sensitivity to dental materials in cell cultures}; Puza VV et al.; This paper discribes a method that enables a qualitative analysis of the biological effects of stomatological materials upon living cells cultivated in vitro to be made . This method allows to make photographic records, at regular intervals of time, of those cells which are originally in a state of suspension, then start to adhere to the bottom of the vessel used for purposes of cultivation, when they become flat and wider . This method takes of the capability of cytoplasmic membranes to respond to any kind of chemical or physical noxa . Quick-motion pictures taken at regular intervals of time using cine film provide for a quantitative differentiation and determination of the ratio of dilated to nondilated cells, which can be analyzed statistically.

Zahn Mund Kieferheilkd Zentralbl, 1977, 65(8), 859 - 62
{Methods for the biological testing of dental materials on cell cultures}; Novak L et al.; This paper discusses some of the methods used by for making basic biological tests of stomatological materials . Although we do not dispense with the use of methods based upon the observation of fixed and, possibly, stained cells and allowing the states assumed by cells in a certain period of time to be noted, yet we believe that far better results may be obtained from tests enabling the development of changes of living cells cultivated in vitro to be followed . The results of the experiments conducted by the authors indicate that it is possible for the final effect to be modified in dependence upon the type of material used, its concentration, or the time allowed to elapse from the preparation of the particular material and that an observation of living cells procides much more information about the character of alterations and, more specifically about the time course of changes . If necessary, this method may be supplemented by an electronmicroscopical analysis of the changes produced.

Acta Derm Venereol, 1977, 57(6), 469 - 75
Studies on guinea pig skin cell cultures . VI . Growth kinetics of epidermal keratinocytes and dermal fibroblasts; Delescluse C et al.; The growth kinetics of epidermal keratinocytes (EK) and dermal fibroblasts (DF) have been determined by four different methods: incorporation of 3H-thymidine into DNA (3H-microgram DNA ratio); 3H-thymidine/14C amino acid incorporation ratio (3H:14C ratio); 3H-thymidine labelled nuclei, and colchicine-blocked metaphase counts . The growth curve of EK was no different when plotted with the 3H:14C ratio than with the 3H-microgram DNA ratio . However, this was not true for DF . The replacement of sodium bicarbonate with Hepes buffer in the culture medium did not greatly affect the shape of the EK growth curve, whereas the DF growth curve became diphasic instead of monophasic . The elimination of mature (differentiated) keratinocytes from the very onset of EK culture had a profound effect on the EK growth curve . DNA synthesis peaked at day 1 in cultures without, instead of day 9 in cultures with differentiated cells . Furthermore, mitotic activity did not show up before day 6 . This suggests that (i) EK in culture are sensitive to the G1 inhibitor released by differentiated epidermal cells, and (ii) they remain in G2 for about 5 days . Thus, EK in culture seem to continue to be susceptible, as in vivo, to homeostatic regulation through the action of G1-G2 inhibitors.

Arch Virol, 1977, 54(3), 201 - 9
Cell culture studies with a cytopathic bovine rotavirus; McNulty MS et al.; The growth characteristics in MDBK cells of a calf rotavirus isolated in Northern Ireland are described . Of a range of cell cultures tested, the virus grew in secondary bovine kidney and MDBK cells, but consistently produced a CPE only in MDBK cells . The CPE consisted of cytoplasmic vacuolation, development of eosinophilic intracytoplasmic inclusions, and degeneration and detachment of cells from the monolayer . The onset of CPE was more rapid and its effects more severe in rolled cultures than stationary cultures . Immunofluorescent staining showed that the rotavirus was antigenically unrelated to avian and mammalian reoviruses . There was no significant difference in virus growth over the pH range 6.5 to 8.4.

Am J Trop Med Hyg, 1977 Jan, 26(1), 47 - 57
Comparison of cell culture with epimastigote antigens of Trypanosoma cruzi; Gam AA et al.; Various epimastigote antigens of Trypanosoma cruzi were compared with an amastigote-trypomastigote antigen from infected cell cultures by complement fixation (CF) and gel diffusion (Ouchterlony) . CF results with human Chagasic sera showed that the amastigote-trypomastigote antigen was usually more sensitive than epimastigote antigens tested . In addition, cross-reactions with normal and other sera were no greater and perhaps less frequent than with crude epimastigote antigens . Specificity of the amastigote-trypomastigote antigen, however, was less than with a protein extract of epimastigotes . Gel diffusion results with human Chagasic and hyper-immunized rabbit sera indicated differences between epimastigote and amastigote-trypomastigote antigens whereas differences by CF with the same sera were equivocal.

Am J Trop Med Hyg, 1977 Jan, 26(1), 37 - 46
A complement-fixing antigen from Trypanosoma cruzi grown in cell cultures; Neva FA et al.; A complement-fixing (CF) antigen was prepared from amastigotes and trypomastigotes of Trypanosoma cruzi (Ernestina strain) grown in beef embryo cell cultures . Multiple lots of the antigen, which consisted of a supernate of washed and disrupted organisms, required material from 10(6) to 10(7) total organism per ml for optimum CF activity . Antibody at dilutions up to 1:256 was demonstrable in various sera from infected animals or patients . Contaminating beef cells from infected cultures were shown to be partly responsible for crossreactions of the antigen by CF with sera from cases of cutaneous leishmaniasis in whom concomitant infection with T . cruzi could be excluded . There were no cross-reactions with syphilitic sera and the frequency of positive reactions with normal sera was very low . Some characterisitics of the antigen included stability to storage at -20 degrees C and -70 degrees C for months, inactivation at 60 degrees C and by lyophilization, and an estimated molecular size of between 50,000 and 100,000 on the basis of membrane filtration.

J Biol Chem, 1976 Dec 25, 251(24), 7733 - 8
Assembly of the sarcoplasmic reticulum . Biosynthesis of calsequestrin in rat skeletal muscle cell cultures; Zubrzycka E et al.; Temporal patterns of biosynthesis of the sarcoplasmic reticulum protein, calsequestrin, were analyzed and compared with rates of ATPase synthesis in primary cultures of rat skeletal muscle cells . Rates of synthesis were measured by the incorporation of radioactive leucine into the isolated proteins . Cells at various stages of differentiation were incubated for 2 h with tritium-labeled leucine and extracted with detergent . The extracts were incubated with antibodies specific against calsequestrin or the ATPase and immunoprecipitates were separated by disc gel electrophoresis . Incorporation of radioactivity into bands identified as calsequestrin or the ATPase was analyzed by counting of gel slices . In Dulbecco's modified Eagles medium (DME medium) containing 0.1 volume of horse serum and 0.005 volume of chick embryo extract, the cells began to fuse after about 50 h in culture, forming multinucleated myotubes . Calsequestrin synthesis was barely detectable after 24 h in culture . After 44 h, before fusion of myoblasts began, the rate of calsequestrin synthesis increased severalfold . The rate of synthesis continued to increase until about 72 h and then diminished . If cells were transferred at 44 h to DME medium containing 0.2 volume of fetal calf serum and 0.08 volume of chick embryo extract, fusion was delayed by about 20 h . In this medium the rate of calsequestrin synthesis diminished after a peak at 44 h but, by contrast, the rate of synthesis of the ATPase increased dramatically following fusion at about 80 h . If cells were transferred at about 40 h to DME medium containing 0.1 volume of horse serum and only 60 muM Ca2+ the cells did not fuse and, again, the rate of calsequestrin synthesis was diminished after a peak at about 40 h . By contrast the rate of ATPase synthesis increased sharply in spite of the lack of fusion . Both proteins were degraded with a half-life of about 20 h . These studies show that the synthesis of calsequestrin, an extrinsic membrane protein, and the ATPase, an intrinsic protein of the same membrane, are synthesized under separate control.

Biochemistry, 1976 Dec 14, 15(25), 5458 - 66
On the inhibitory activity of 4-vinyl analogues of pyridoxal: enzyme and cell culture studies; Korytnyk W et al.; Analogues of pyridoxal and of pyridoxal phosphate in which the 4-CHO group is replaced with CH = CH2 were synthesized and were found to be potent inhibitors of pyridoxal kinase and pyridoxine phosphate oxidase of rat liver . They also inhibited the growth of mouse Sarcoma 180 and mammary adenocarcinoma TA3 in cell culture . Saturation of the vinyl double bond, replacement of the 5-CH2OH with methyl, methylation of the phenolic hydroxyl, or conversion to the N-oxide resulted in diminution or loss of all these activities . Similarly, the introduction of a beta-methyl group into the vinyl analogues of pyridoxal reduced all these inhibitory activities . The 4-vinyl anatogue of pyridoxal was shown to be a substrate of pyridoxal kinase and the product a potent inhibitor of pyridoxine oxidase, competing with pyridoxal phosphate . The affinity of this phosphorylated pyridoxal analogue to some apoenzymes varied greatly, indicating striking differences among the cofactor binding sites of these enzymes . The growth inhibitory effects of these analogues on cells in culture correlated well with their effects on pyridoxal kinase and pyridoxine phosphate oxidase in cell-free systems.

Dev Biol Stand, 1976 Dec 13-15, 37, 273 - 86
Post-exposure use of human diploid cell culture rabies vaccine; Kuwert EK et al.; 880 individuals, 120 of which were exposed to rabid animals, were immunized pre- or post-exposure with 2 different BPL-inactivated and concentrated rabies vaccines prepared in HDC strains WI-38 and MRC-5 . The vaccines were well tolerated and no major side effects were observed after primary immunization with 3-10 doses or 1 booster vaccination . The dynamics of neutralizing, antibody formation and persistence of antibodies in 4 different groups of vaccinees are described . The groups were vaccinated pre-exposure (I) on days 0, 28 and 56; (II) on days 0, 7 and 14; (III) on days 0, 3, 7 and 21; and (IV) post-exposure on days 0, 3, 7, 14, 30 and 90 . High antibody levels--persisting for at least 30 months--were obtained in all patients . The CFT, using a concentrated and purified virion antigen, was highly specific for rabies virus antibody demonstration . Since in some 50 patients under severe risk, after having been bitten and/or scratched by proven rabid animals, not a single breakthough of immunity was observed during an observation time between 1/2 and 3 years, the protective effect of the HDCS-rabies vaccines seems to be excellent . With regard to their high immunogenicity and extremely low reactogenicity, the new HDCS-vaccines can be recommended for prophylactic and post-exposure immunization of man without any reserve . Data on simultaneous application of homologous anti-rabies gammaglobulin from man (20 I.E./kg body-weight) and HDCS-vaccines are also presented and discussed.

Dev Biol Stand, 1976 Dec 13-15, 37, 91 - 5
Use of polyethyleneglycol-treated serum for animal cell cultures; Barteling SJ; Although many proteins will be removed from sera by precipitation with 10% polyethyleneglycol (PEG) the growth-promoting properties of such PEG-treated sera for many cell lines and cell strains are hardly reduced . Among the precipitated proteins are the macroglobulins which are difficult to remove from cell cultures and which may cause allergic reactions if incorporated into vaccines . The gammaglobulins are removed in this way as well . If the sera are contaminated with viruses or phages the titres will be reduced by approximately 4 logs and thus the incidence of virus contamination will be reduced by the PEG-treatment . For foot-and-mouth Disease (FMD) vaccine production PEG-treated sera from vaccinated cattle were applied for cell and virus cultivation . The virus obtained was subsequently precipitated with PEG and collected by filter-aid filtration . A concentrated virus product was obtained, which was practically devoid of serum proteins.

Biochim Biophys Acta, 1976 Dec 13, 454(3), 493 - 503
Altered leucyl-transfer RNA synthetase from a mammalian cell culture mutant; Haars L et al.; Altered leucyl-tRNA synthetase from a mammalian cell culture temperature-sensitive mutant, tsHl, was compared with enzyme from normal wild type Chinese hamster ovary cells . The mutant enzyme had a Km for leucine four times larger than that of wild type and enzyme levels 3-10% that of wild type . The presence of tRNA was necessary during in vitro heating of the mutant enzyme to allow expression of thermolability while the presence of tRNA protected wild type enzyme against thermal inactivation . The tsHl enzyme was stable when heated alone or in the presence of tRNA, leucine, and ATP simultaneously . The mutant's enzymes aminoacylated tRNALeu, tRNAVal, and tRNAIle with fidelity in vitro as determined by cochromatography of the amino-acyl-tRNA isoacceptors on RPC-5 reversed phase chromatography . The mutant failed to show any defect other than the direct formation of leucyl tRNALeu by leucyl-tRNA synthetase.

Brain Res, 1976 Dec 3, 117(3), 461 - 85
Synaptic transmission between rat superior cervical ganglion neurons in dissociated cell cultures; Ko CP et al.; The principal neurons of the rat superior cervical ganglion (SCGN) when established as dissociated cells in tissue culture form synapses among themselves . In the present study we have examined this synaptic interaction when these neurons are co-cultured with several other types of tissues . Dissociated SCGN were prepared from perinatal rats and studied, after 3-4 weeks maturation, with intracellular recording techniques . Synaptic interactions between sympathetic neurons were demonstrated when these cells were: (a) grown with explants from newborn rat thoracic spinal cord, (b) when the SCGN had survived for several weeks subsequent to removal of the spinal cord explants, and (c) when the SCGN were grown in the presence of an adrenergic target (interscapular brown fat cells) . Unidirectional, reciprocal, recurrent and complex chemical synaptic networks, consisting of convergence and divergence, characterized connections between SCGN . All synaptic responses were cholinergic since they were reversibly blocked by hexamethonium or mecamylamine but were not sensitive to 10(-5) M phenoxybenzamine . Removal of the spinal cord explants did not significantly alter the proportion of chemical synaptic interactions between SCGN (more than 25%) from matched cultures . Anatomical observations established that in cultures with brown fat, innervating neurites appeared on the fat cells; these neurites frequently expanded to form varicosities that resembled the adrenergic terminals normally seen on brown fat in the animal . Synaptic profiles also occurred on the neurons in these cultures and some of these were shown to be cholinergic . The proportion of neuronal interactions in the combined SCGN + fat cultures was low, however, suggesting that co-culture with target tissue might influence the frequency of interconnections developed between SCGN in culture . Other factors, such as the presence of non-neuronal cells, degree of dissociation, cellular density, culture age and the survival of certain types of SCGN in culture are discussed as variables related to the formation of synapses between SCGN . Non-rectified electrical coupling between SCGN was also observed in 17 out of 679 pairs (2.5%) of neurons . Attenuation factor for electrically coupled action potentials ranged between 1 and 43.5.

In Vitro, 1976 Dec, 12(12), 821 - 32
Conditions affecting primary cell cultures of functional adult rat hepatocytes . II . Dexamethasone enhanced longevity and maintenance of morphology; Laishes BA et al.; Primary monolayer cell cultures of adult rat hepatocytes underwent change in morphology and substantial cell loss between 1 and 3 days postinoculation . Dexamethasone-supplementation (1 micronM) of the culture medium maintained the polygonal epithelial morphology of the hepatocytes and increased longevity such that over 80% of the cells survived for 3 days and at least 30% for 8 or 9 days . This enhancement of survival was obtained up to 48 hr postinoculation, but the earlier the time of dexamethason supplementation the greater the effect . Removal of dexamethasone resulted in a decrease in longevity . The positive effect of dexamethasone on longevity was observed following dexamethasone replacement of insulin in supplemented cultures, but the combination of insulin and dexamethasone resulted in poorer survival than with dexamethasone alone . The results are interpreted to indicate that dexamethasone provided a requirement of the in vitro environment for survival and suggest that elaboration of a complex medium is required to maintain hepatocytes in culture.

Arch Biol Med Exp (Santiago), 1976 Dec, 10(1-3), 120 - 1
The replacement of serum by hormones in cell culture media; Sato G et al.; The replacement of serum by hormones in cell culture media . (Reemplazo del suero por hormonas en el medio de cultivo de celulas) . Arch . Biol . Med . Exper . 10: 120-121, 1976 . The serum used in cell culture media can be replaced by a mixture of hormones and some accesory blood factors . The pituitary cell line GH3 can be grown in a medium in which serum is replaced by triiodothyronine, transferrin, parathormone, tyrotrophin releasing hormone and somatomedins . Hela and BHK cell strains can also be grown in serum free medium supplemented with hormones . Each cell type appears to have different hormonal requirements yet it may found that some hormones are required for most cell types.

Cell, 1976 Dec, 9(4 Pt 1), 511 - 21
Differentiation of the epidermal keratinocyte in cell culture: formation of the cornified envelope; Sun TT et al.; Human epidermal keratinocytes grow from single cells into stratified colonies . Cells in the upper layers of the colonies lose their ability to divide and begin terminal differentiation . In this process, there develops a cornified cell envelope that remains insoluble after heating in solutions of sodium dodecylsulfate and beta-mercaptoethanol . The insolubility of the cornified envelope depends upon proteins, since after treatment with proteolytic enzymes, the envelope becomes soluble in the detergent . Cells with cornified envelopes can be identified under the light microscope either in living colonies or following fixation and silver nitrate staining . Keratinocytes of the basal layer move in a characteristic way, but cornified cells do not move at all and form an immobile upper layer in the colonies . Keratinocytes disaggregated from growing colonies are of differing size and density, and can be separated on isopycnic gradients of Ficoll . The DNA-synthesizing cells are small (mean diameter 14 mum) . The nonmultiplying cells are large and have a protein content proportionate to their size . Their final diameter may exceed 30 microns (volume increase greater than 10 fold) . Cornified envelopes are found in some of the large cells but in none of the small . In growing colonies, usually 5-10% of the cells have cornified envelopes . The fraction is reduced in colonies growing in the presence of epidermal growth factor . Strain XB, an established keratinocyte line of mouse teratomal origin, also forms cornified envelopes, but the kinetics of the process are different, indicating that the program of terminal differentiation is not initiated at corresponding times in the two cell types.

Blood, 1976 Dec, 48(6), 923 - 9
The effect of chelating agents on iron mobilization in Chang cell cultures; White GP et al.; The investigation of chelating agents with potential therapeutic value in patients with transfusional iron overload has been facilitated by the use of Chang cell cultures . These cells have been incubated with {59Fe}transferrin for 22 hr, following which most of the intracellular radioiron is found in the cytosol, distributed between a ferritin and a nonferritin form . Iron release from the cells depends on transferrin saturation in the medium, but when transferrin is 100% saturated, which normally does not allow iron release, desferrioxamine, 2,3-dihydroxybenzoic acid, rhodotorulic acid, cholythydroxamic acid, and tropolone all promote the mobilization of ferritin iron and its release from cells . They are effective to an approximately equal degree . The incubation of {59Fe}transferrin with tropolone in vitro at a molar ratio of 1:500 results in the transfer of most of the labeled iron to the chelator, reflecting the exceptionally high binding constant of this compound . How far these phenomena relate to therapeutic potentially remains to be seen.

Can J Physiol Pharmacol, 1976 Dec, 54(6), 814 - 21
Dispersed cell cultures of the rat pineal: growth and morphological differentiation; Wilkinson M; A method is described for the preparation and growth of rat pineal monolayer cultures derived from both mature and immature animals . The cultures were observed to undergo profound but reversible morphological differentiations by addition of dibutyryl-cAMP, monobutyryl-cAMP, papaverine, prostaglandins, and adenosine, and by removal of serum . Sodium butyrate and theophylline had no effect . Time-lapse photography indicated that this reversible transformation took place via a contraction-relaxation mechanism . Both colcemid and cytochalasin B inhibited the transformation . These results demonstrate that this type of morphological transformation, previously demonstrated in tumour and embryonic cell cultures, can also occur in nonembryonic, non-neoplastic tissue, and may be related to a general dedifferentiative process occurring in monolayer cultures.

Acta Virol, 1976 Dec, 20(6), 506 - 11
Persistent SV5 virus infection in continuous cell cultures; Zakstelskaya LY et al.; A continuous line of guinea pig kidney cells (CGPK/H) and a continuous line of mouse fibroblasts (L/H) spontaneously infected with parainfluenza virus SV5 were found . These cultures showed no enhanced cell degeneration or symplast formation, nor was haemagglutinin accumulation or infectious virus demonstrated in them . However, regular reproduction of ribonucleoprotein (RNP) characteristic of parainfluenza viruses, morphologically complete virions and antigens producing antibody to SV5 virus were found in the cells . Focal haemadsorption neutralized by antiserum to SV5 virus was also demonstrated . The infection persisted in the cell populations for over 2 years (the observation period) under standard conditions of cell dispersion and subcultivation.

J Exp Med, 1976 Nov 2, 144(5), 1243 - 53
Antibodies in human sera to oncorna virus-like proteins from normal or leukemia marrow cell cultures; Louie S et al.; Some human marrows in culture release particles with oncornavirus-like properties . This study was designed to examine the immunological properties of similar particles in human marrow culture supernates . Leukemic and nonleukemic marrows were cultured for 5-7 days in the presence of {14C}uridine and {3H}leucine or {3H}glucosamine . Labeled supernatant components banding in sucrose gradient densities of 1.20-1.24 g/ml were used as antigen in a double antibody immunoprecipitation assay . The assay was validated by end point titrations and competition with unlabeled antigen; purified myeloma proteins were used as negative controls . Cross-reactivity with mammalian oncornaviruses, as judged by competitive inhibition of precipitation by these viruses, was slight and at the border of the sensitivity of the method . Precipitated antigens analyzed by SDS polyacrylamide gel electrophoresis contained three distinct polypeptides of about 70,000, 45,000 and 30,000 mol wt; these comigrated with the gp 70, pg 45, and p 30 of a murine leukemia virus . Similar polypeptides were obtained from both leukemic and nonleukemic marrow culture supernates . As determined by the radioimmunoprecipitation assay, 32 of 45 leukemic sera (71%), 36 of 45 normal sera (80%), 15 of 19 sera from family contacts of leukemic patients (79%), 14 of 21 cord blood specimens (67%), and 21 of 23 sera (91%) from patients with systemic lupus erythematosus had detectable antibody activity.

J Immunol, 1976 Nov, 117(5 Pt.2), 1817 - 23
Induction or suppression of B cell proliferation and differentiation by phytohemagglutinin or concanavalin A in mouse spleen cell cultures; Piguet PF et al.; Cultures of mouse spleen cells or various mixtures of mouse T and B cells were stimulated with PHA or Con A, and the T, B, or plasmablast nature of the transformed cells, was determined by immunofluorescence 2 to 4 days later . The lectins enhanced B cell proliferation and plasmablast differentiation ("helper" effect) provided one of the following conditions was fultilled: a) suboptimal doses of lectin were used, b) cultures were performed at low cell concentration, c) cultures were made of spleen cells containing a small percentage of T cells, d) the cultures contained a mixture of T-depleted spleen cells and T cells rendered unable to proliferate by irradiation . In contrast, cultures performed with 1.5 10(6) or more spleen cells/ml and optimal doses of lectin contained almost exclusively T blasts, as did cultures stimulated in the same conditions with both PHA and LPS . This last observation idicates the existence of a lectin-induced "suppressor" effect, since LPS, a B cell mitogen, induces, in the absence of PHA, a marked B cell proliferation and differentiation into plasmablasts . These helper and suppressor effects were entirely mediated by T cells, since they were not observed in spleen cell cultures depleted in T cells by anti-thets + C . Analysis of the cultures by immunofluorescence and radioautography after pulses of 3H-thymidine showed that these antagonistic effects could be related to the number of T blasts present in the culture and to their proliferative behavior . Heoper effect is observed in cultures containing a relatively low number of T blasts (or none in cultures made with irradiated T cells), whereas suppressive effect is observed in cultures containing a high number of T blasts, a large proportion of them having left the proliferative cell cycle . It is proposed that when a critical concentration of T blasts is reached ("saturation density"), further proliferation and differentiation is prevented, resulting in a suppressive effect on the generation of plasmablasts . The helper effect of lectin-activated T cells seems to be exerted on a subpopulation of B cells which was, at least in part, already proliferating in vivo, and to result in a polyclonal IgM plasmablast differentiation.

Acta Cytol, 1976 Nov-Dec, 20(6), 577 - 81
Monolayer cell cultures as target cells for the study of lymphocyte cytotoxicity in cancer patients; Serrou B et al.; Lymphocytotoxicity using S3-Hela target cells has been studied in 20 cancer patients treated with ionizing radiation (head and neck, lung and breast cancers) . Monolayer cultures of Hela cells were marked with radioactive 51 Chromium and cultured with non stimulated or phytohemagglutinin (PHA) stimulated lymphocytes . This study shows a spontaneous decrease of lymphocytotoxicity in cancer patients as compared with normal subjects and an immunodepressive effect of radiotherapy . We observe a significant decrease of lymphocytotoxicity for either stimulated or non-stimulated lymphocytes at the end of radiation treatment . Moreover one month after completion of radiotherapy a possible repair of a lymphocytoxicity seems to be related with a short-term (6 months) good prognosis.

Biokhimiia, 1976 Nov, 41(11), 1983 - 6
{Identification of RNAase-sensitive 20S RNA in a cell culture infected with Sindbis virus}; Petkevich AS et al.; RNAse-sensitive 20S RNA component with molecular weight of 0.7-10(6) is found when analysing virus-specific RNAs isolated from cultured chicken embryo fibroblasts infected with Sindbis virus by means of gradient centrifugation and polyacrylamide gel electrophoresis.

J Dairy Sci, 1976 Nov, 59(11), 1881 - 9
Comparative production of beta-lactoglobulin and orotic acid with lactose in bovine mammary cell cultures: effects of cell density and constituent inhibition; Larson BL; Abilities to accumulate beta-lactoglobulin and ortic acid were compared to lactose in dispersed cell cultures of lactating bovine mammary tissue . The inverse of the amount accumulated of each milk constituent at a given time in the culture medium was a linear function of the inverse of the cell density . The amount of lactose had no effect on its own subsequent accumulation, but added orotic acid and beta-lactoglobulin inhibited their own production . The accumulation of certain milk constituents in the culture medium is a factor in the expression and loss of normal function in the in vitro cultures which may be related to the observed effects of milk accumulation in vivo on the rate of milk synthesis and mammary involution.

Prostaglandins, 1976 Nov, 12(5), 871 - 80
The simultaneous use of two prostaglandin radioimmunoassays employing two antisera of differing specificity . II . Relative stability of prostaglandins E1, E2 and F1alpha in cell cultures of BALB/c 3T3 and SV3T3 mouse fibroblasts; Ritzi EM et al.; The relative stability of Prostaglandins (PGs) E1, E2 and F1alpha in cultures of BALB/c 3T3 and SV3T3 cells has been evaluated using 3 different approaches . First, total recovery of tritium in the ethyl acetate phase following incubation and extraction of PGF1alpha and PGE1 demonstrated greater stability for PGF1alpha (88.8%) than PGE1 (65.9%) . Second, analysis of incubated, extracted, tritiated PGs by thin layer chromatography revealed decreases of up to 23% in the PGE zone following incubation of 3H-PGE1 . With increasing time of incubation, decreases in the PGE zone were accompanied by increase in PGA-like compounds . 3H-PGF1alpha demonstrated greater stability, having greater than 90% recovery of the tritium in the PGF zone . A third approach to the assessment of PG stability in culture was the comparison of the production of individual PGs by radioimmunoassay (RIA) . The data obtained by RIA indicated a lag in the increase of PGA and PGB, until an initial rise in PGE was noted, suggesting that PGA and PGB may be secondary products arising from PGE which exhibits only partial stability in culture . By employing two RIAs, one for total PGE and one for PGA and PGB, the composite determination PG {E + (A + B)} can be used to provide a more meaningful determination of PG production because of the instability of the PGs . On the other hand, individual determinations are helpful in assessing the stability of PGEs in cell cultures.

Cancer Res, 1976 Nov, 36(11 Pt 1), 4062 - 8
Stimulated DNA synthesis in mouse epidermal cell cultures treated with 12-O-tetradecanoyl-phorbol-13-acetate; Yuspa SH et al.; Exposure of mouse epidermal cells in culture to 12-O-tetradecanoyl-phorobol-13-acetate (TPA) results in an initial inhibition of DNA synthesis for 24 hr followed by a 5- to 10-fold stimulation at 72 to 96 hr . A corresponding increase in mitotic rate also occurs at 72 to 96 hr . These responses occur when TPA is continuously present in the medium or if the exposure is as short as 1 hr, but the degree of stimulation was dependent on dose and duration of exposure . Sensitivity to TPA varied with the length of time the cells were in culture prior to treatment . TPA treatment also produced an alteration in morphology from clearly epithelial to a more fibroblastic type . These biochemical and morphological effects did not occur after treatment of epidermal cells with either phorbol-13,20-diacetate or phorbol . Primary dermal fibroblasts in culture did not respond to TPA in this manner, but a line of cultured liver epithelial cells was slightly stimulated by the promoter . This system appears to be a sensitive in vitro model for detecting the hyperplasia-inducing effects of phorbol esters and should be used for mechanistic studies and bioassay.

Ann Microbiol (Paris), 1976 Nov-Dec, 127B(4), 573 - 6
{A rapid assay of Sindbis virus infectivity by counting immunofluorescence foci in "Aedes albopictus" cell culture (author's transl)}; Digoutte JP et al.; The Aedes albopictus cell line is susceptible to numerous arboviruses but the appearance of cytopathic effect is observed mostly with flavivirus . A method of rapid titration of Sindbis virus by counting immunofluorescent foci is described, using this cell line.

J Immunol, 1976 Nov, 117(5 Pt.2), 1753 - 6
Replication of herpes simplex virus in mouse spleen cell cultures stimulated by lipopolysaccharide; Kirchner H et al.; Replication of HSV was demonstrated in spleen cell cultures of D2 and several other strains of mice after prestimulation with mitogenic doses of LPS for 2 days . No viral replication occurred in unstimulated cultures or in cultures prestimulated with PHA and Con A, whereas there was some viral replication in spleen cell cultures of D2 mice after prestimulation with Poly I-C . Spleen cells of B6 mice did not support replication of HSV under any of the conditions we have tested thus far . The reasons for this defect are not clear, but it was obviously not caused by a defective lymphoproliferative response to LPS or by an active anti-viral principle elaborated by B6 spleen cells . F1 hybrids between B6 and D2 mice were capable of HSV replication to the same extent as were spleen cells of D2 mice . Several strains of both HSV-1 and HSV-2 could be replicated in D2 spleen cells cultures . Nylon column treatment of D2 spleen cells removed the ability to replicate HSV, whereas macrophage removal from the spleens by plastic adherence was without effect . Purified peritoneal exudate cells from D2 mice did not support replication of HSV . Together these data suggest that B cells activated by LPS represent the target cell of HSV replication in mouse spleen cell cultures.

Cancer Res, 1976 Nov, 36(11 Pt 1), 4152 - 9
In vitro transmission and propagation of the bovine leukemia virus in monolayer cell cultures; Graves DC et al.; This study demonstrates that the bovine leukemia virus (BLV) can infect in vitro cells of human, simian, bovine, canine, caprine, ovine, and bat origin . Cultures of these cells, cocultivated with BLV-infected cells or inoculated with cell-free BLV preparations, continuoously showed the presence of cells with the internal BLV antigen as well as BLV-induced syncytia . Virus replication was abundant and increased with passage in bat lung cells and was moderate but constant in fetal canine thymus cells . The amounts of virus released by the simian DBS-FRhL-1 and caprine S-743 cultures were low to moderate during the first 4 to 8 weeks and decreased thereafter . In the infected fetal lamb spleen cell cultures, virus production was low and declined further with passage . Bovine embryonic spleen and human diploid embryonic lung WI-38 cell cultures produced very small amounts of virus only during the first two passages after inoculation despite the fact that they remained infected, as determined by the continuous presence of cell BLV antigen and syncytia . Morphologically and antigenically, the virus particles released by the monolayer cell cultures were indistinguishable from those found in short-term and long-term cultures of BLV-infected bovine lymphoid cells . Repeated electron microscopic examinations and serological tests showed that all the BLV-infected cultures, including those from which the infecting inocula were obtained, were free of the foamy-like bovine syncytial virus, parainfluenza 3 virus, infectious bovine rhinotracheitis virus, bovine viral diarrhea virus, and the maedi-like bovine R-29 virus.

Cancer Res, 1976 Oct, 36(10), 3784 - 8
Radiation-induced murine leukemia ERLD in cell culture; Albrecht AM et al.; The lymphoblastic leukemia ERLD, induced by radiation in a C57BL/6 mouse, was established in culture . Three cell lines, ERLD/Y3, ERLD/T ERLD/Two, have been in culture for nearly three years . Their isolation and growth depended upon the presence of 2-mercaptoethanol, glutamine, and asparagine in the medium . The cell lines, except ERLD/T, possess the TL antigen, a characteristic of ERLD and of other murine leukemia cells in vivo and of normal thymus cells of certain mouse strains, but not of C57BL/6 . A distinctive submetacentric marker chromosome is also common to ERLD and the derived cell lines . The successful establishment of ERLD in culture provides a malignant thymocyte-related cell system for studies in nutrition and immunobiology.

Dev Biol Stand, 1976 Oct, 36, 305 - 6
The production and use of rinderpest cell culture vaccine; Kalunda M; Description of preparation, safety and efficacy testing of a rinderpest cell culture vaccine which is observed in lyophilized form and should be used within two hours following its reconstitution . Excellent results have been obtained with this vaccine in Kenya, Uganda and Tanzania.

Atherosclerosis, 1976 Oct, 25(1), 111 - 23
Light- and electron-microscopic characteristics of artrial smooth muscle cell cultures subjected to hypoxia or carbon monoxide; Paule WJ et al.; Smooth muscle cells from the tunica media of piglet aortae grown under hypoxic conditions undergo the following changes: First, they become modified by partial loss of myofilaments and proliferation of organelles, which are characteristics of young primitive cells . Second, an increase in number of pinocytotic vesicles at and below the cell surface, indicating increased extracellular uptake of material, can be detected . This is followed by accumulation of Oil Red O positive intracytoplasmic granules and vacuoles as well as the subsequent formation of mount-like protrusions . The latter consist of a core of extracellular material and necrotic debris covered with a cap of viable cells . A third feature of the cells subjected to hypoxia is a conspicuous rise in the number of lysosomes . This is considered to be a manifestation of a defense mechanism of the cells to remove undesirable material from cytoplasm . Cells exposed to an atmosphere rich in carbon monoxide exhibit basically the same alterations as those grown under hypoxic conditions; however, formation of mound-like aggregates is less prominent, while the rise in the number of lysosomes is more evident than in the hypoxic cells . The above alterations are similar to changes observed in smooth muscle cells of rabbit with experimental atherosclerosis . It is suggested that whereever the arterial smooth muscle cell is subjected to adverse conditions basically the same mechanism, consisting of dedifferentiation, increased permeability and lysosomal defense reaction, takes place.

Parasitology, 1976 Oct, 73(2), 137 - 48
Drug screening in cell culture for the detection of anticoccidial activity; Ryley JF et al.; Methods for screening compounds against Eimeria tenella in cell culture and in the chicken are described . An analysis for incidence of anticoccidial activity and host cell toxicity has been made of 11550 compounds screened in vitro, and some correlation of activity in vitro and in vivo has been attempted . The results show that screening compounds in tissue (cell) culture is not a satisfactory or reliable alternative to screening in chickens, although in vitro studies undoubtedly have a part to play in the evaluation of an active drug.

Br J Cancer, 1976 Oct, 34(4), 374 - 80
Allogeneic grafts of spontaneous canine melanomas and their cell culture strains in neonatal immunosuppressed dogs; Betton GR et al.; Canine melanoma has been transplanted to allogeneic neonatal recipients receiving continuous immunosuppression with anti-lymphocyte serum . One spontaneous melanoma was directly transplanted into 8 recipients, 6 of which developed tumours . 5/5 melanoma cell cultures were transplantable, with 19 tumour takes in 31 allogeneic recipients . Serial passage was performed in the case of two melanomas . Tumour development required continuous immunosuppression and the site was dependent upon the route of inoculation and other factors . Transplanted cell cultures were all amelanotic in vitro and in vivo, except in the case of one melanoma which reverted to a melanotic morphology after in vivo growth.

Cancer Res, 1976 Oct, 36(10), 3742 - 7
Growth rates of normal and abnormal human mammary epithelia in cell culture; Buehring GC et al.; The in vitro growth rates of different classifications of human mammary epithelium were compared . Samples included 4 established breast cell lines and excised tissue or breast fluid cells originating WOMEN FOR 40 DIFFERENT AND comprising 3 classifications: normal, nonmalignant atypical, and malignant . Growth was quantitated in situ and expressed as population-doubling time . Principal findings were: (a) malignant cells divided at a slower mean rate than normal cells; (b) population-doubling time values of malignant cells were more heterogenous than those of normal cells; (c) cultures from nonmalignant atypias showed population-doubling time means and standard deviations between those of normal and malignant cells; and (d) long-term mammary tumor cell lines divided more slowly than did normal cells . Discussion includes implications of data for the preneoplastic state and cell culture of mammary epithelium.

Biull Eksp Biol Med, 1976 Oct, 82(10), 1270 - 1
{Origin of stromal mechanocytes in the bone marrow cell cultures}; Ivanov-Smolenskii AA et al.; The method of indirect immunofluorescence with the use of the isolinear antiserum was applied to the study of the linear reference of fibroblasts growing in the monolayer bone marrow cultures from the semisyngenous heterotropic transplants and radiochimerae . As shown, fibroblasts from the bone marrow of complete radiochimerae were of the recipient origin, whereas the histiocytes-macrophages (in the same cultures) - of donor origin . All the fibroblasts in the bone marrow cultures of the heterotropic transplant belonged to the initial donor, whereas 80% of the histiocytes were recipent's . This is a direct proof of the fact that stromal mechanocytes and hemopoietic cells, and also macrophages belonged to different cell lins.

J Clin Microbiol, 1976 Oct, 4(4), 360 - 71
Examination of various cell culture techniques for co-incubation of virulent Treponema pallidum (Nichols I strain) under anaerobic conditions; Sandok PL et al.; Treponema pallidum (Nichols virulent) was incubated with and without cells in cell culture medium reduced to -275 mV Ecal, pH 7.3, under deoxygenated conditions . Five to ten percent of the treponemes attached to cells and remained motile for at least 120 h in cell-treponeme systems of co-incubation . Virulent treponemes could be detected after 120 to 144 h in the supernatant fluids of cell-treponeme co-incubation cultures and in cell-free tubes containing medium harvested from aerobically cultivated mammalian cells . Medium supplemented with ox serum ultrafiltrate, pyruvate, and sodium thioglycolate and gas mixtures containing H2 and CO2 enhanced treponemal survival . Increases in treponemal numbers were observed using dark-field microscopy but were not substantiated using the rabbit lesion test . Continuous passage of the treponeme was not achieved in vitro.

J Invest Dermatol, 1976 Oct, 67(4), 541 - 7
Transfer mechanism of melanosomes in epidermal cell culture; Okazaki K et al.; The mode of melanosome transfer from melanocytes to keratinocytes in epidermal cell cultures has been examined with time-lapse cinematography and electron microscopy . A tip of a melanocyte dendrite containing melanosomes became enfolded by a recipient keratinocyte . It was then pinched off to form a cluster of melanosomes which initially seemed to be surrounded by two layers of membranes . The phagocytized dendrite was gradually decomposed and became an aggregate of melanosomes surrounded by a single membrane of the keratinocyte . The individual melanosomes were dispersed from the aggregate into the keratinocyte cytoplasm, depending on the size of melanosomes . The larger ones were single and smaller ones were complex . The mechanism of melanosome transfer in vitro is a type of cytophagocytosis . The entire process consists of two steps: the first is a cytophagic process and the second a melanosome dispersion process . The process is influenced by various exogenous factors.

J Infect Dis, 1976 Oct, 134(4), 324 - 7
Effect of neutral red and light on Herpesvirus hominis type 1 in cell culture; Fife T et al.; Various concentrations of neutral red were added to monolayers of muscle-skin fibroblasts after adsorption of Herpesvirus hominis type 1 . The concentration necessary to reduce plaque counts was found to be 10(-5.5) M . At the same time, the minimal toxic concentration of neutral red for muscle-skin fibroblasts was determined by the concentration that reduced the plaques of a challenge virus, vesicular stomatitis virus, that was applied after treatment with neutral red and light . The minimal toxic concentration was found to be 10(-5) M . Thus, the effective concentration of neutral red for H . hominis in tissue culture appears to be only slightly less than the minimal toxic concentration . The concentrations used for clinical trials in humans have been 10(3)-10(4) times this amount . Any observed efficacy of such treatment may be a reflection of cell toxicity.

Cell Differ, 1976 Oct, 5(3), 161 - 70
Surface glycosaminoglycans as a differentiation cofactor in neuroblastoma cell cultures; Augusti-Tocco G et al.; The possible role of surface glycosaminoglycans (GAGs) in neuronal maturation occuring in neuroblastoma cultures has been investigated . GAGs of neuroblastoma cells, grown in suspension and monolayer, were labelled with 3H-glucosamine and 35S-sulfate . Neuron maturation, following cell adhesion to culture dishes, is accompanied by an increased ability of the cells to retain heparan sulfate (HS) on their surface, which is otherwise lost into the culture medium . The role of surface HS as a cofactor of cellular differentiation is discussed.

C R Seances Soc Biol Fil, 1976 Oct, 170(3), 661 - 5
{Attempt to obtain in vitro pre-erythrocyte forms of Plasmodium vivax in human liver cell cultures inoculated with sporozoites}; Doby JM et al.; Using sporozoites of a strain of Plasmodium vivax of North Korean origin maintained in human subjects and in Anopheles atroparvus, the authors inoculated human liver cell cultures (primary cultures and Ist subcultures) . The appearance of some rare intracytoplasmic forms is described, which are thought to be very likely connected with the pre-erythrocytic cycle of P . vivax . Further attempts are nevertheless necessary to confirm, or invalidate, the obtained results.

In Vitro, 1976 Oct, 12(10), 693 - 701
Cell culture factors influencing in vitro expression of mouse mammary tumor virus; Fine DL et al.; Several cell culture factors were found to influence in vitro expression of mouse mammary tumor virus (MMTV) in the mouse adenocarcinoma cell line Mm5mt/c1 . Cells were propagated in a variety of commercially available cell culture media to which dexamethasone (DXM) was added as a stimulator of MMTV production . Culture seeding density, culture medium type, and glucose concentration each influenced MMTV production when expressed on a per cell basis . Maximum cell growth occurred in cultures grown in RPMI-1640 medium containing insulin . Those media which provided good cell growth were not necessarily optimal for virus expression . Addition of insulin did not stimulate MMTV synthesis although dexamethasone alone was stimulatory in all media used; however, maximum MMTV expression was obtained when dexamethasone and insulin were used in concert . Equivalent levels of MMTV-specific cell membrane antigen, MMTV-specific protein, and virus particles were produced at incubation temperatures of 32 degrees, 34 degrees or 37 degrees C; however, higher levels of virus-related RNA-dependent DNA polymerase (RDDP) activity were recovered from cultures incubated at 32 degrees and 34 degrees C than at 37 degrees C . Decreased levels of RDDP were attributed to enzyme thermolability at 37 degrees C incubation.

Gann, 1976 Oct, 67(5), 755 - 62
Detection of oncornavirus-like particles in normal and tumorigenic rat liver cell cultures; Narayan KS et al.; Six epithelial cell cultures established from adult Wistar rat liver were examined by electron microscopy for oncornavirus-like particles . Two heteroploid and tumorigenic cultures demonstrated many cells with virus-like particles of type-A and type-C morphology . The remaining four, composed of diploid nontumorigenic cells, demonstrated similar virus-like particles but in few cells and only after bromodeoxyuridine treatment . The virus-like particles in the tumorigenic cultures were identified as a rat type-C virus by serological assays.

In Vitro, 1976 Oct, 12(10), 687 - 92
Atmospheric stability in cell culture vessels; Balin AK et al.; We have investigated that atmospheric stability in polystyrene and glass cell culture vessels by measuring the dissolved O2 and CO2 in the media of both seeded and unseeded culture vessels incubated at 37 degrees C . There was no diffusion of either O2 or CO2 through glass vessels . At low partial pressures of oxygen (PO2), oxygen diffused into the polystyrene flasks at a rate of 1 to 2 mmHg per 24 hr, and at high PO2, oxygen diffused slowly out of polystyrene flasks . CO2 diffused out of polystyrene flasks with a half-time of 260 hr resulting in a considerable elevation in pH . In seeded polystyrene flasks with the PO2 less than or equal to room air, cellular oxygen consumption was masked by the inward diffusion of oxygen . In addition, the fall in pH due to metabolic CO2 and organic acid production during cell growth in polystyrene flasks was buffered by the diffusion of CO2 out of the vessels.

Science, 1976 Sep 17, 193(4258), 1152 - 4
Myosin synthesis increased by electrical stimulation of skeletal muscle cell cultures; Brevet A et al.; When cultures of skeletal muscle cells of the chick embryo are subjected to repetitive, electrical stimulation, the contractions increase the amount of protein produced by these cells . The increase is greater for contractile proteins such as myosin heavy chain than for total cellular protein . This demonstrates that in a culture system of skeletal muscle cells that have differentiated in the absence of innervation, one can elicit the protein synthetic response associated with skeletal muscle hypertrophy in vivo.

In Vitro, 1976 Sep, 12(9), 649 - 53
Proliferative capacity of cell cultures derived from the human placenta; Vincent RA Jr et al.; The placenta consists largely of fetal tissue, yet at term it displays histological signs of deterioration not apparent in the fetus . To determine whether the apparent degeneration of the placenta is genetically determined, the life-spans of placental cell cultures and the proportion of placental cells capable of incorporating {3H}thymidine for replicative DNA synthesis in vitro were measured . Under the culture conditions employed, the placental cells were removed from the influence of many extrinsic factors thought to play a role in the degeneration of the placenta in vivo . Cultures of fibroblast-like cells derived from the placenta exhibited a reduced life-span and correspondingly reduced proportion of cells able to incorporate {3H}thymidine for DNA synthesis in comparison to cultures derived from the fetal skin and the maternal decidua . These results suggest that intrinsic cellular processes may be involved in the apparent degeneration of the placenta.

Immunology, 1976 Sep, 31(3), 433 - 41
Differentiation of lymphoid cells: the non-mitogenic induction of immunoglobulin production by thymus cell extract and thymus cell culture filtrate; Shinohara N et al.; The cell-free medium in which thymocytes have been cultured (filtrate) as well as sonic lysates of thymocytes (extract) enhance immunoglobulin production when added to spleen cells during tissue culture . In spite of the requirement for foetal calf serum in the culture medium, production of the enhancing factor in thymocyte culture filtrates occurred even in the presence of a variety of metabolic inhibitors including NaN3, puromycin and hydroxyurea . Although DNA synthesis is required as a prelude to the induction of immunoglobulin production, two lines of evidence indicate that the enhancement produced in response to filtrate and extract occurs via a non-mitogenic process . First, neither cell-free agent was mitogenic toward spleen cells . Secondly, the enhancement of immunoglobulin production due to filtrate or extract was observed even in the presence of inhibitors of DNA synthesis . Multiple functions for thymocytes in the induction of immunoglobulin production are indicated by the findings that thymocytes restore immunoglobulin production of anti-thymocyte serum-treated spleen cells, whereas filtrate and extract, alone or in combination, do not have this capability . Furthermore, filtrate and extract failed to enhance the induction of DNP-group-specific antibody production by cells incubated with DNP-protein, but filtrate and extract could partially restore anti-DNP antibody production of such anti-thymocyte serum-treated cells . The role of thymocytes, filtrate and extract in the antigen-independent and the antigen-dependent induction of immunoglobulin production is discussed.

Tsitologiia, 1976 Sep, 18(9), 1079 - 84
{Protein SH-group concentration and RNA synthesis during the process of induction of proliferation in the stationary phase of cell culture growth}; Terskikh VV et al.; The dynamics of intracellular protein SH-group (PSH) content was studied cytochemically in the course of stimulation of cell proliferation in stationary cultures of an established Chinese hamster cell line and of human diploid embryo fibroblasts . The results were compared with the pattern of RNA synthesis during the prereplicative period . In Chinese hamster cells immediately after medium changing in stationary cultures there is an augmentation of PSH content in parallel withe the increase in RNA synthesis rate . Later on, the rate of RNA synthesis and PSH content are seen decreasing followed by a new increase in the rate of RNA synthesis correlated with the second rise in PSH content . In stationary cultures of human diploid fibroblasts, there is also an increase in the rate of RNA synthesis and in the content of SH after medium changing, but the second wave of RNA synthesis and the second rise in PSH content are not pronounced . The variation in PSH content reflects the shift in the cell metabolism during the prereplicative period and is not attributed to changes in cell protein content.

In Vitro, 1976 Sep, 12(9), 643 - 8
Spread and control of mycoplasmal infection of cell cultures; McGarrity GJ; Environmental sampling was performed during trypsinization and passage of 3T-6 cell cultures that contained a mean of 4.3 X 10(7) colony forming units (CFU) per ml supernatant of A . laidlawii . The lip of the culture flask and the outside of the used pipet were always heavily contaminated . The outside of the culture flask (3/7), the work surface (8/12) and the outside of a pan of disinfectant (4/5) were regularly contaminated with mycoplasmas . Airborne mycoplasmas were detected eight of 32 times (25%) by settling plates; simultaneous forced-air samplers by two different methods were always negative . The technician's hands were contaminated two of 15 samples . When hands were contaminated, more contamination was detected in the environment . Droplets of A . laidlawii and M . orale inoculated onto work surfaces survived drying for a minimum of 3 days, even in laminar airflow cabinets . Twenty-five of 31 (80.6%) cell culture technicians carried M . salivarium in their throats; only two carried M . orale . It is concluded that mycoplasma-infected clltures are the most common source of further infection . Recommendations for prevention and control of mycoplasmal infection are listed.

Vopr Virusol, 1976 Sep-Oct, (5), 545 - 50
{Comparative study of antigens specific for hepatitis B in transfected cell cultures}; Anan'eva VA et al.; A comparative study of antigens detected in the livers of patients with hepatitis B . in the mesonephros of the human tissue--chick embryo system infected with the agents isolated from the blood of hepatitis patients, as well as antigens detectable in cell cultures transfected by the DNA isolated from these tissues was carried out . The results are in favour of the hypothesis on the integrational nature of serum hepatitis.

Cancer Treat Rep, 1976 Sep, 60(9), 1317 - 24
Studies with 2,5-piperazinedione, 3,6-bis(5-chloro-2-piperidyl)-,dihydrochloride . II . Effects on macromolecular synthesis in cell culture and evidence for alkylating activity; Brockman RW et al.; 2,5-Piperazinedione, 3,6-bis(5-chloro-2-piperidyl)-,dihydrochloride (NSC-135758) inhibited DNA synthesis but not RNA and protein synthesis in Adenocarcinoma 755 cells in culture . The expression of such inhibition was delayed in time; it was necessary to expose tumor cells to NSC-135758 for 10-12 hours before measuring the macromolecular synthesis in order to demonstrate selective inhibition of DNA synthesis . Inhibition of DNA synthesis was demonstrated to be irreversible in human epidermoid carcinoma cells in culture . Exposure of cells in suspension culture to NSC-135758 or to melphalan for 1-4 hours, and then incubation of cells in the absence of an inhibitor for 20 hours, resulted in preferential inhibition of DNA synthesis; inhibition of RNA synthesis was observed under these conditions but was less pronounced . Chemical evidence for alkylating activity of NSC-135758 and of the bis-aziridine derived from it (NSC-201424) was obtained by demonstrating their reaction with 4-(p-nitrobenzyl)pyridine . NSC-135758 was more potent as a cytotoxic agent than was its derivative, a result which suggests that NSC-135758 is the active alkylating agent . Reaction of NSC-135758 with diethylamine was examined; the product obtained upon alkylation of diethylamine by NSC-135758 was identified from its proton magnetic resonance spectrum and by field desorption mass spectral analysis . These results support the view that NSC-135758 acts as an alkylating agent in inhibiting DNA synthesis and cell proliferation of tumor cells in culture.

In Vitro, 1976 Sep, 12(9), 639 - 42
Karyology of primary human fetal cell cultures; Earley EM et al.; Cell cultures were established from the biopsies of lung, skin and kidney from each of nine human fetuses, and chromosome analyses were performed on material through the fifth subculture . Kidney cell cultures generally showed a higher level of polyploidy than lung or skin . The frequencies of hyperdiploid cells and those with structural abnormalities were consistent with the low levels found in cultures of human lymphocytes . The data provide a normal cytogenetic baseline for human fetal material which may be useful in a variety of studies.

Vopr Virusol, 1976 Sep-Oct, (5), 610 - 3
{Cytopathology of cell cultures infected with adenovirus and with a biologically active preparation of its DNA}; Arkhangel'skii DS et al.; Comparative characteristics of cytopathic changes in the cell cultures infected with adenovirus and with a biologically active preparation of adenovirus DNA are presented . The pathological process in the cells infected with the infectious DNA differs from that after virus infection by a shortened time of DNA penetration into the cell and a shortened latent period of infection development . The development of the pathological process in the cell cultures was accompanied by a complex of cytological changes with predominant affection of the nuclei and formation of intranuclear inclusions staining green with acridine orange . The distinctive feature of these changes was the time of their appearance: in cultures infected with the virus inclusions were formed within 12-48 hours, in those infected with DNA within 9-18 hours . The fluorescent antibdoy procedure revealed a virus antigen in these cultures induced by DNA preparationand by the virus, at different stages of its accumulation . The nucleoplasm was the site of specific antigens synthesis . The distribution of the virus antigen in the infected cells corresponds to the morphological pictures of intranuclear inclusions at later stages of infection which confirms the viral nature of the latter . The dynamics of the development of cytological changes and intranuclear inclusions in the infected cells as well as synthesis of a specific antigen in them are directly related to the quantitative accumulation of the virus.

Biull Eksp Biol Med, 1976 Sep, 82(9), 1121 - 3
{Effect of thyroxine on the mitotic cycle of cell cultures}; Ivchenko TN et al.; Thyroxin taken in concentration of 10 mug/ml exert a different influence on the mitotic cycle periods of the HeLe-cells in the log and stationary growth phases of the culture . During the log phase of growth thyroxine reduces the tG 2min period (for 2 hours), without influencing the other periods of mitotic cycle . In the stationary growth phase thyroxine reduces the mitotic cycle duration by 3--7 hours, chiefly on account of the accelerated G1 plus 1/2 M (by 4--8 hours) and partially of the G2min periods (by 1 hour) . A conclusion on the hormonal stimulation of the cell entry into the mitotic cycle from the Go periods in the stationary culture was drawn.

Exp Hematol, 1976 Sep, 4(5), 289 - 300
The influence of steroids on erythropoiesis in mouse fetal liver cell cultures: relevance of cell cycle state; Dunn CD et al.; It has been shown that erythropoietin-mediated stimulation of heme synthesis in mouse fetal liver cells in vitro is correlated with hydroxyurea sensitivity . Assuming that OHU is specifically cytotoxic for cells in DNA synthesis this suggests that erythropoietin sensitivity may be related to this phase of the cell cycle . The direct effects of 19-nortestosterone and 3beta-hydroxy-5beta-pregnan-20-one on heme synthesis correlated with the capacity of these steroids to initiate DNA synthesis . It is suggested that the ability of these steroids to increase the proportion of cells in the Ep-sensitive phase of the cell cycle is probably the mechanism responsible for the erythropoietic effects of these agents . 17beta-hydroxy-5alpha-androstan-3-one appears to have a different mode of action since it has only minimal effects on heme synthesis and did not increase hydroxyurea sensitivity.

J Cell Physiol, 1976 Sep, 89(1), 77 - 88
Selective isolation of reversible cold sensitive variants from Chinese hamster ovary cell cultures; Ohlsson-Wilhelm BM et al.; Variants of the Chinese hamster ovary cell line CHO-KI (ATTCCCL61)which grow almost normally at 38.5C but very poorly or not at all at 30C were obtained after treatment with mutagens and application of an indirect selection procedure . Two kinds of variants were recovered . In the first of these, the cold sensitive phenotypw is expressed completely only at low cell densities . At higher cell desity, growth continues at the nonpermissive temperature, but at a reduced rate . In the second class, the cold snesitive phenotype is independent of cell density . Two members of the latter class were studied in detail . In both lines, after shift to the nonpermissive temperature, the rateof H-thymidine incorporation declines markedly; the rates of H-uridine and H-phenylalanine uptake are less drastically reduced . Autoradiographs indicate that the decline in thymidine uptake at the nonpermissive temperature is due to an elongation of part of the cell cycle, so that a smaller proportion of the cells lie in the synthetic (S) phase of the cell cycle with a consequent reduction in the fraction labeled cells . The uridine labeling patterns of the mutants appear to rule out a ribsomal lesion . Low temperature growth inhibition of both cell strains was reversible . In one of the cell lines, an apparent stretching of the cells at the low temperature produces substantial alterations in cell shape.

J Clin Microbiol, 1976 Sep, 4(3), 253 - 7
Effect of vaccination schedule on immune response of Macaca mulatta to cell culture-grown Rocky Mountain spotted fever vaccine; Sammons LS et al.; The effect of vaccination schedule on the immune response of Macaca mulatta to formalin-inactivated chicken embryo cell culture (CEC)-grown Rickettsia rickettsii vaccine was studied . Schedules consisted of inoculation on day 1 only, on days 1 and 15, on days 1 and 30, on days 1, 8, and 15, or on days 1, 15, and 45 . Humoral antibody measured by microagglutination and indirect immunofluorescence and resistance to challenge with 10(4) plaque-forming units of yolk sac-grown R . rickettsii were assessed . Seroconversion was noted in all monkeys after the first dose of vaccine . A second dose administered 8 or 15 days after the primary infection, or a third given 7 or 30 days after the second, produced no long-term effect on antibody titer . Only monkeys given two doses of vaccine at a 30-day interval showed an increase in antibody titer during the period before challenge . Vaccination with one, two, or three doses of CEC vaccine prevented development of rash and rickettsemia after challenge . The two-dose schedules appeared to induce the highest degree of resistance to challenge, as indicated by unaltered hematological parameters and body temperature in monkeys . The one- and three-dose schedules were somewhat less effective, in that some challenged monkeys within each group displayed febrile and leukocyte responses associated with Rocky Mountain spotted fever infection . Our data suggest that administration of two doses of CEC vaccine at 15- or 30-day intervals is the immunization schedule of choice.

Infect Immun, 1976 Sep, 14(3), 811 - 5
Radioimmunofluorescent antibody technique for detection of reovirus antigen in cell culture; McCammon JR; Antibody against reovirus type I must partially purified and conjugated with fluorescein isothiocyanate (FITC) . The FITC-labeled antibody was then conjugated with 125I . A gamma globulin fraction of normal sera was similarly labeled with FITC followed by a 131I label . The FITC + 125I-labeled immune reagent was then mixed on an equal protein basis with the FITC + 131I control reagent . This mixture was used to stain acetone-fixed reovirus-infected cover slips . After staining, the cover slips were examined by fluorescence microscopy . Infected cover slips demonstrated characteristic reovirus immunofluorescence, whereas uninfected cover slips were negative . After visual examination, the cover slips were placed in tubes and counted in a two-channel gamma analyzer . By comparing the quantitative isotope data with the qualtitative information from immunofluorescence on a single preparation, it was possible to correlate antigen production sites with quantitative production values.

In Vitro, 1976 Sep, 12(9), 628 - 34
Spontaneous contractions of dispersed vascular muscle in cell culture; Hermsmeyer K et al.; Dispersed vascular muscle cells from chick omphalomesenteric vessels maintained in primary cell culture contracted spontaneously . Six methods which produced contracting isolated muscle cells are described and compared . The combination of dispersion method and culture conditions to produce contracting muscle cells was more critical for vascular than for heart muscle . These findings of continuing pacemaker function demonstrate that functional integrity of isolated vascular muscle cells is possible to maintain . Further indication of the full functional state of the isolated vascular muscle cells was demonstrated by the sensitivity to norepinephrine at a physiological concentration (0.1 muM) . Spontaneous contraction frequencies were similar to the range found in situ, and spontanious or norepinephrine-induced contractions had time courses corresponding to intact vessel contractions . This is the first report that isolated vascular muscle cells in primary cell culture retain functional characteristics found in situ and are suitable for pharmacological characterization of individual muscle cells.

Surv Ophthalmol, 1976 Sep-Oct, 21(2), 160 - 4
Type 1 and type 2 herpes simplex virus in corneal cell cultures; Oh JO; The pathogenicity of herpes simplex virus (HSV) in primary cultures of epithelia, stromal, and endothelial cells of rabbit corneas was studied at various incubation temperatures (30 degrees, 36 degrees, and 40 degrees C) . We tested three strains each of type 1 (HSV-1) and type 2 (HSV-2) . At all three temperatures, the epithelial cells appeared to be more susceptible to both HSV-1 and HSV-2 than the stromal and endothelial cells . In general, less HSV-1 was requered than HSV-2 to infect the same type of corneal cell at the same incubation temperature . At 40 degrees C, however, there was far less cell destruction by either HSV-1 or HSV-2 than at 30 degrees or 36 degrees C . This inhibition at 40 degrees C was more pronounced in the cells infected with HSV-2 than in those infected with HSV-1, and the inhibition was accompanied consistently by significant suppression of virus multiplication in the cells.

Proc Soc Exp Biol Med, 1976 Sep, 152(4), 651 - 5
Occurrence in human bone marrows of an antigen released from continuous cell cultures derived from human leukemia; Smith CC et al.; Fluorescent antibodies prepared against extracellular particles from a continuous culture of cells derived from a monocytic leukemia stained JIII cells but not cells infected with Rauscher leukemia virus or simian sarcoma virus . These antibodies reacted with 38% of bone marrow preparations from patients with lymphoma, 26% of preparations from patients with nonmalignant blood disorders and 6% of preparations from patients with leukemia . Bone marrow films from patients with lymphoma over the age of 50 stained less frequently than those from patients under 50 . These particles released from JIII cells are not antigenically related to two of the commonly studied oncornaviruses, but may be indicative of the etiology or disease process of lymphoma in young patients.

Proc Soc Exp Biol Med, 1976 Sep, 152(4), 645 - 50
Characterization of extracellular particles released from continuous cell cultures derived from human leukemia; Smith CC et al.; Extracellular particles, with a density of 1.18-1.22 g/cm3 in sucrose, were detected in the culture medium of a continuous cell line (JIII) derived from a patient with monocytic leukemia . These particles contained RNA, DNA, and a DNA polymerase . They synthesized DNA with endogenous templates and primers and also used exogenous DNA but not poly(rC) oligo(dG) as a template . Pretreatment with Nonidet P-40 stimulated DNA polymerase activity while treatment with ribonuclease partially inhibited the enzyme activity . Fluorescent antibodies made to the particles stained both JIII and Z-597 cells derived from human leukemias but not other types of human or nonhuman cultured cells tested . The particles do not appear to be oncornaviruses but may be a particulate antigen associated with malignant cells of hemopoietic and lymphoid origin.

J Gen Virol, 1976 Sep, 32(3), 461 - 70
Morphological observations on the replication of herpesvirus saimiri in monkey kidney cell cultures; Morgan DG et al.; Owl and African green monkey kidney cell cultures have been infected with 1 p.f.u./cell of herpesvirus saimiri and sample cultures have been taken for examination by electron microscopy at 3 to 6 hourly intervals over a period of 7 days; the experiments were repeated several times . The peculiarly slow replication cycle of Herpesvirus saimiri has enabled distinct cytoplasmic and nuclear phases in virus maturation to be clearly distinguished; the overall fine structural features were similar in both cell types . Immature particles were first detected in the nucleus and cytoplasm 63 h after infection . Thereafter, abundant cytoplasmic immature particles matured by budding through cytoplasmic membranes until about 100 h, whereas nuclear immature particles budded through the inner nuclear membrane or intranuclear invaginations of it later, from about 100 h until cytolysis was complete at 160 h . Morphological differences were also observed between particles budding at cytoplasmic membranes and the nuclear envelope . At the former site the membrane overlying the bud showed an electron opaque thickening which imparted to the mature particle an asymmetrical appearance . Such thickenings of the envelope were not observed in mature particles of nuclear origin . Unusual tubular and laminated nuclear structures were seen towards the end of the replicative cycle corresponding with the phase of nuclear virus maturation by budding; the morphology of the latter structures is described.

Am J Vet Res, 1976 Sep, 37(9), 1103 - 5
Development of a cell culture line of bovine fetal endometrial cells; Soto-Belloso ER et al.; Monolayers of bovine fetal endometrial cells were established as primary culture cells within 1 to 2 weeks . After the 2nd passage, these cells were inoculated with bovine viral diarrhea virus . Effects of the virus were observed each day with a light microscope . Specific cytopathic effects consisting of degeneration and sloughing of the cells and a well-defined pattern of cytoplasmic vacuolation were observed at 5 days after inoculation.

Am J Vet Res, 1976 Sep, 37(9), 1011 - 6
Neutralization of a transmissible gastroenteritis virus of swine by colostral antibodies elicited by intestine and cell culture-propagated virus; Morilla A et al.; Cross-protection studies of gilts exposed to 4 transmissible gastroenteritis viruses--Ilinois (field strain), Miller-3, Miller low passage (M-LP), and Miller high passage (M-HP) tissue culture-adapted--indicated that only the gilt vaccinated with Illinois strain was protected, along with its newborn pigs, against challenge exposure with field virus . Similar results were obtained when the 4 viruses were incubated in vitro with colostrum from each of the 4 vaccinated gilts and subsequently used to orally inoculate newborn pigs . However, when the colostrums were used to neutralize M-HP virus in cell cultures, the neutralization titers were similar, indicating that a close antigenic relationship existed among the viruses . Neutralization studies in cell cultures, using immunoglobulin (Ig) fractions derived from colostrums of sows exposed to Illinois and M-HP virus, indicated that Illinois virus elicited more neutralizing activity in IgA than in the IgG fraction and that M-HP virus elicited more IgG than IgA antibody activity . In another study, Illinois virus was treated with these Ig-enriched fractions and then inoculated into the lumen of the jejunum of 3-day-old pigs . Anti-Illinois IgA was the only class of antibody which prevented replication of the Illinois virus in the intestine . Similar intraintestinal inoculations were used to test invasiveness of untreated Illinois and M-HP viruses . It was demonstrated that Illinois virus caused marked effect on the intestine: shortening of the villi, intestinal distension, edema, and presence of accumulated intestinal fluid within 60 hours after inoculation . The M-HP virus grew in the intestinal cells without affecting the length of the villi . The degree of invasiveness of Illinois or M-HP virus may account for the difference in the antibody class elicited in the colostrums.

Endocrinology, 1976 Sep, 99(3), 684 - 91
Gastrin in the perinatal rat pancreas and gastric antrum: immunofluorescence localization of pancreatic gastrin cells and gastrin secretion in monolayer cell cultures; Braaten JT et al.; The presence and development of immunoreactive gastrin (IRGa) in the fetal and neonatal pancreas and pyloric antrum of the rat were studied . IRGa appeared in both organs at least as early as the 16th day of fetal life . Antral IRGa increased rapidly and continuously in the neonatal period, while pancreatic IRGa concentration increased and was maintained at a relatively constant level from days 5 to 35 . Monolayer cell cultures of the neonatal rat pancreas were used to evaluate the role of cyclic AMP mediated release of gastrin . The addition of N6,O2'-dibutyryl cyclic AMP (4 mM) or theophylline (4 mM) to the culture medium induced significant release of gastrin . The stimulation of adenylate cyclase with cholera toxin (10 ng/ml) also resulted in significant gastrin release . Long-term cultures (18-24 days) were shown to release gastrin continuously at a relatively constant rate . The cellular localization of pancreatic gastrin in 7-day-old cultures was performed by immunological techniques, using fluorescein-labeled antibodies to gastrin . The gastrin-containing cells were located at the periphery of most of the endocrine cell clusters . Immunofluorescence techniques for insulin and glucagon also showed that the alpha cells had a similar peripheral distribution, although they were more frequent in number . In contrast, insulin-containing cells were numerous and were present in all areas of the endocrine cell clusters . The studies support the following conclusions: a) Gastrin is present in the rat pancreas, even as early as late fetal life; b) Gastrin-producing cells are present and functionally competent in monolayer cell cultures of the neonatal rat pancreas for prolonged periods of time (24 days); c) Gastrin is released from these cells when intracellular levels of cyclic AMP are increased; d) By immunofluorescence methods, the gastrin-producing cells in pancreatic cell cultures are found to be located at the periphery of the endocrine cell clusters.

Mol Biol (Mosk), 1976 Sep-Oct, 10(5), 987 - 97
{Rate of DNA synthesis and the size of replication units in cell culture of Drosophila melanogaster}; Anan'ev EV et al.; The rate of DNA replication and the size of replication units was examined by means of pulse-labeling with 3H-thymidine and DNA autoradiography in the chromsomes of Drosophila melanogaster synchronized cells culture in vitro . The center-to-center distance between adjacent labeled section of DNA fibers was taken for a size of replication unit, i.e . replicon . DNA synthesis was revealed to start simultaneously in most replicons . The rate of elongation of labeled sections of DNA fibers is about 25 mu per hour (75 kb per hour) . Taking into consideration bidirectinal DNA replication the rate of DNA replication per growing point is 12.5 mu per hour (38 kb per hour) . The mean size of replicon is about 60 mu (130 kb) in cell culture of Drosophila melanogaster and most of these replicons vary from 20 to 80 mu . Calculation suggests that one replicon may consist of six chromomeres each being known to be formed by a segment of DNA molecular 10 mu long on average.

Biochim Biophys Acta, 1976 Aug 24, 444(1), 69 - 74
Inhibition of proteoglycan biosynthesis by hyaluronic acid in chondrocytes in cell culture; Handley CJ et al.; The depression of proteoglycan synthesis in ten-day-old high density chondrocyte cultures was shown to be dependent on both the concentration and time of exposure of the cells to hyaluronic acid . Hyaluronic acid had no effect on the overall protein synthesis by the cultured cells . Using benzyl-beta-D-xyloside an exogenous acceptor, it was shown that glycosaminoglycan biosynthesis by the chondrocytes was not affected by hyaluronic acid . It was concluded that hyaluronic acid was effecting glycosaminoglycan chain initiation, hence proteoglycan biosynthesis, either by specifically depressing the synthesis of the core protein or by repressing the activity of the xylosyltransferase.

Brain Res, 1976 Aug 6, 112(1), 103 - 12
Cholinesterase activity and choline uptake in intact nerve cell cultures; Massarelli R et al.; Choline uptake and ecto-cholinesterase activities have been measured in intact astroblast and neuroblast cultures . The data show that choline uptake is dependent upon the ionic composition of the culture medium and is sensitive to metabolic inhibitors . However, the high concentrations of the inhibitors necessary for the inhibition of the uptake and some thermodynamic properties qould suggest a facilitated transport rather than an active uphill process . Preincubation of the cultures with various inhibitors of cholinesterases shows no direct parallelism between inhibition of choline high affinity uptake (apparent Km approximately equal to 10-6 M) and inhibition of ecto-acetylcholinesterase (EC 3.1.1.7).

In Vitro, 1976 Aug, 12(8), 571 - 9
The measurement of spatial precursor distributions in cell culture; Carlsson J et al.; The distribution of incorporated radioactive precursors, for both DNA and protein synthesis, has been measured with a resolution of about 1 mm in cell cultures, using a scanning technique . Either gamma radiation and X-rays or beta radiation (electrons) were detected by scintillation detectors . Spectrophotometer measurements with a resolution of 1 mm gave good estimates of cell density changes . Glioma cell colonies were used to compare this technique with autoradiography . Variables such as the density of labelled cells and percentage of labelled cells could be estimated rather accurately . For example, an increased cell density was correlated to a local decrease in DNA synthesis.

In Vitro, 1976 Aug, 12(8), 554 - 7
Preparation of delipidized serum protein for use in cell culture systems; Rothblat GH et al.; A rapid procedure for the preparation of delipidized serum protein is described . The delipidized protein can be used for the maintenance and growth of tissue culture cells in a lipid-free environment . The extraction procedure greatly reduces all serum lipid classes and the delipidized protein supports the growth of a variety of cells in culture.

Zh Mikrobiol Epidemiol Immunobiol, 1976 Aug, (8), 41 - 3
{Adsorption of different cell cultures on colonies of M . hominis}; Neustroeva VV et al.; A study was made of sorption of 6 continuous lines of cells on the colonies of 55 M . hominis strains isolated from patients with inflammatory diseases of the urogenital tract . M . hominis proved to be capable of sorbing various cell cultures on the colonies . The sorption depended on the type of the culture . The greatest sorption capacity was possessed by the cells of human origin --FL and HeLa . M . hominis strains under study differed by their capacity to cell sorbtion . The method of cell sorption on the colonies can be suggested for the determination of heterogeneity of the population and of the intrastrain differences in M . hominis.

Biull Eksp Biol Med, 1976 Aug, 82(8), 995 - 8
{Isolation and characteristics of a continuous human splenic cell culture}; Sovetova GP et al.; A continuous cell line of human spleen has been obtained . The methods of seeding large numbers of cells and prolonged cultivation of the culture played an important role in isolation of this cell line; both methods have contributed to the creation of conditions for gradual reconstruction of the cellular metabolism in the absence of which the cells wound not be able to get adapted to contiuous cultivation . As the authors failed to obtain a contiuous cell line from a single cell colony the method of "shaking" was applied . The culture was obtained only in case of a 1% PHA solution was added to the nutrient medium.

Appl Environ Microbiol, 1976 Aug, 32(2), 209 - 12
Effect of disinfectants on variola virus in cell culture; Tanabe I et al.; Twenty kinds of disinfectants were examined for ability to inactivate variola virus . Cytopathic effect and plaque formation on monolayer cultures of an established monkey kidney cell line were used as indicators of virus inactivation . A micromethod using microplate cultures, and not requiring a CO2 incubator, was adopted . The procedures were straightforward, showing good reproducibility . Among the compounds tested, several were found to be superior because of the minimum concentrations required for complete inactivation of virus . The purified viruses were shown to be more sensitive to the compounds than were the crude samples . The virus inactivation kinetics curves were determined by plaque counting . The usefulness of this method for quantitative analysis of disinfecting effect is suggested.

Endocrinology, 1976 Aug, 99(2), 516 - 25
Changes in (125I) labeled human chorionic gonadotropin (hCG) binding to porcine granulosa cells during follicle development and cell culture; Stouffer RL et al.; The specific binding of (125I)iodo human chorionic gonadotropin to porcine granulosa cells isolated at two stages of follicle maturation was quantitated immediately after harvest and following 6-7 days of culture . Both porcine LH (pLH, LER 786-3) and hCG inhibited (125I)iodo hCG binding, while pFSH (ler-1132) did not compete for hCG with granulosa cells for 24-48 hours at 37 C did not alter its subsequent ability to bind to fresh cells . The binding of (125I)iodo hCG was a rapid process which was not readily reversible . Scatchard analysis of the equilibrium binding data resulted in linear plots showing the hCG binding capacity of highly differentiated (HD) cells, harvested from large preovulatory follicles, to be significantly greater than that of moderately differentiated (MD) cells isolated from smaller luteal phase follicles, both before (794 vs 93 pmoles/g; P less than 0.001) and after (157 vs 5 pmoles/g; P less than 0.001) culture . A decline in binding capacity occurred in both cell groups during culture and was associated with a significant decrease in progestin production . In contrast, the hCG binding affinity of the granulosa cell was equivalent at both stages of follicle development and remained unchanged after 6 days of culture (mean apparent Kd = 2.9 x 10-10M; n=27 . These data indicate that porcine granulosa cells contain a homogeneous class of LH receptors whose number, but not affinity, increases during follicle maturation in vivo . The loss of receptors in vitro suggests the absence of some factors(s), as yet unidentified, critical to the maintenance and development of the receptor population.

J Protozool, 1976 Aug, 23(3), 397 - 402
Effect of fixation on demonstration of phosphatases of Eimeria tenella grown in chick kidney cell cultures; Vetterling JM et al.; The effects of fixation with various concentrations of glutaraldehyde or formaldehyde, acetone or ethanol, and freeze-drying on 5 phosphatases of Eimeria tenella and chick kidney cell cultures were demonstrated in situ . Gultaraldehyde inactivated the phosphatases more than did the formaldehyde, but the effect of the combination of the 2 (Karnovsky's fixative) was greater than that of either glutaraldehyde or formaldehyde alone . The higher the concentration of aldehyde and the longer the duration of exposure, the greater the inactivation . The order of sensitivity to aldehyde fixation of the enzymes tested was glucose-6-phosphatase greater than thiamine pyrophosphatase greater than 5'-nucleotidase greater than adenosine triphosphatase greater than acid phosphatase . Cytologic detail was preserved more efficiently with glutaraldehyde than with formaldehyde . Optimal preservation of enzyme activity for cytochemistry was with 2% glutaraldehyde for 30 min or 2% formaldehyde for 1 hr for G-6-Pase, TPPase, and 5'-nucleotidase, and with 2% glutaraldehyde or 2% formaldehyde for 2 hr with ATPase and AcPase . Quenching with subsequent fixation in cold acetone or ethanol resulted in complete inactivation of G-6-Pase, TPPase, and 5'-nucleotidase; although cells fixed in this manner yielded large amounts of reaction product for ATPase and AcPase, the distribution was diffuse, and some of it appeared to be artifactual . Quenching with subsequent freeze-drying was unsatisfactory because nearly all of the cell layers rolled off the cover glasses.

J Virol, 1976 Aug, 19(2), 382 - 8
Some biological and physical properties of molluscum contagiosum virus propagated in cell culture; Francis RD et al.; Molluscum contagiosum virus propagated in FL cells of human amnion origin has a one-step growth cycle time of 12 to 14 h . The appearance and exponential increase of intracellular virus preceded the release of extracellular virus by approximately 2 h . Demonstration of comparable titers of extracellular and intracellular virus at the end of the replication cycle indicated that a substantial amount of virus remained associated with cells exhibiting cytopathogenic changes . Mean buoyant density values of virus in sucrose ranged from 1.275 to 1.278 g/cm3, but in CsCl the virus banded at densities at 1.325 to 1.340 and 1.261 to 1.281 g/cm3 . Although virus infectivity was not affected by high concentrations of CsCl, it was found by polyacrylamide gel electrophoresis that the salt removed several nonglycosylated polypeptides with estimated molecular weights of 15,000 to 60,000 . This suggested that the high-density band (1.325 to 1.340) may reflect the loss of these structural components . The half-life of virus infectivity was approximately 26.5 h at 26 degrees C and 11.2 h at 37 degrees C . Although the virus was rapidly inactivated at 50 degrees C, it could be stabilized at this temperature by the presence of 1.0 M MgCl2 . Virus did not agglutinate newborn chick, adult chicken, or type "0" human erythrocytes . Virus infectivity was found to be sensitive to acid pH but resistant to treatment with diethyl ether or chloroform . The replication of molluscum virus in FL cells was not inhibited by 5-iodo-2'-deoxyuridine, 5-bromo-2'-deoxyuridine, or cytosine arabinonucleoside in noncytotoxic concentrations of 200 to 400 mug/ml, but greater than 99% reduction in the yield of herpes simplex virus or vaccinia virus in FL cells was obtained with 200 mug of these compounds per ml . Guanidinium chloride in concentrations of 100 to 200 mug/ml reduced molluscum virus yields by more than 99.9%.

Biochem J, 1976 Jul 15, 158(1), 109 - 17
Induction of benzo{a}pyrene Mono-oxygenase in liver cell culture by the photochemical generation of active oxygen species . Evidence for the involvement of singlet oxygen and the formation of a stable inducing intermediate; Paine AJ; 1 . The photochemical generation of excited states of oxygen in liver cell culture by the mild ilumination of culture medium containing riboflavin, results in stimulation of benzo{a}pyrene 3-mono-oxygenase, a cytochrome P-450-linked mono-oxygenase . 2 . The same large increase in mono-oxygenase activity was found when medium containing riboflavin was illuminated in the absence of cells and then stored in the dark for 24h before contact with the cells . From this it may be inferred that stimulation is due to the formation of a stable inducer in the culture medium . Further experiments indicate that the stable inducer is due to the photo-oxidation of an amino acid . 3 . Evidence that singlet oxygen is responsible for initiating the stimulation of the mono-oxygenase is based on the use of molecules that scavenge particular active oxygen species . Of all the scavengers tested, only those that scavenge single oxygen inhibited the stimulation . 4 . A hypothesis is developed to relate the stimulation of the mono-oxygenase by singlet oxygen in cultured cells to the regulation of the cytochrome P-450 enzyme system in vivo . It is suggested that single oxygen generation within cells may be a common factor linking the many structurally diverse inducers of the enzyme system.

Cell Tissue Kinet, 1976 Jul, 9(4), 395 - 9
The 'transition probability model' and the regulation of proliferation of human diploid cell cultures during aging; Grove GL et al.; Genealogies derived from time-lapse cinemicrophotographic studies of aging human diploid cell cultures were analysed in terms of the 'transition probability' model . It was found that the distribution of intermitotic times obtained from middle passage cells deviated only slightly from that predicted by the model . In contrast, the plot for late passage cultures did not fit the predicted pattern and appeared to be composed of multiple curves . These changes are discussed in reference to cellular senescence as expressed by normal human diploid cells in vitro.

Vopr Virusol, 1976 Jul-Aug, (4), 468 - 73
{Determination of the biosynthetic chemotherapeutic index of antiviral agents in cell culture}; Novokhatskii AS et al.; An experimental substantiation of an improved approach to testing antiviral chemotherapeutic agents in tissue culture was done on the model of Venezuelan equine encephalomyelitis virus and primarily trypsinized chick embryo fibroblasts using some biologically active agents such as actinomycin D, RNA-ase, gentamycin, poly (rI) . poly (rC) . The approach is based on combined use of stationary cultivation of cells and virlses, a method for determination of radioactivity of the cells grown directly in vials for scintillation counting as well as methods for determination of virus-specific and cell syntheses by incorporation of labeled precursors . The features of the mechanism of action of the agents under study is discussed in terms of their influence on cell metabolism.

Zentralbl Bakteriol {Orig B}, 1976 Jul, 162(1-2), 77 - 84
{Heavy metal toxicity in mammalian cell cultures (author's transl)}; Fischer AB; Static suspension cultures of L-A cells, a subline of L 929 mouse fibroblasts, were exposed to inorganic metal salts (chlorides) . There was an increasing cytotoxicity from lead over mercury to cadmium as determined by reduction of viability and inhibition of proliferation . After 7 days' exposure the LD50 of lead was approximately 3 X 10(-4) M, of mercury 5 X 10(-5) M, and of cadmium 1.3 X 10 (-5) M . The doses causing a 50% inhibition of increase in cell number (ID50) after 7 days' application were determined as follows: 4 X 10(-5) M for lead, 1.3 X 10(-5) M for mercury, and 7.5 X 10(-6) M for cadmium . The biological effects of lead during chronic exposure were studied in more detail . Under continuous presence of the heavy metal the cells developed lead resistance, even to concentrations approaching the LD50 . However, the proliferation rates of cells tolerating 1.4 X 10(-4) M were slightly, and of those tolerating 2 X 10(-4) M were clearly reduced as compared to the non-resistant (parent) cells . Cultivation of the resistant cells over 46 days (maximally 60 generations) in lead-free medium lead to a considerable loss of tolerance; this finding indicates that the induced lead resistance is caused by adaptation rather than by mutation and selection.

In Vitro, 1976 Jul, 12(7), 521 - 32
Conditions affecting primary cell cultures of functional adult rat hepatocytes . 1 . The effect of insulin; Laishes BA et al.; The conditions for obtaining representative, primary adult rat hepatocyte cultures were explored . The methods applied included enzymatic liver perfusion which was nondestructive to hepatocytes, the prevention of aggregation of dissociated cells and the selective attachment of viable cells . These procedures yielded a recovery of 50% of the liver cells which gave rise to cultures representing 14% of the total liver cells . The cultures were composed of homogeneous epithelial-like cells cytologically similar to hepatocytes and possessed a number of liver-specific enzymes . There was virtually no cell division initially and most cells died between 24 and 48 hr . Insulin enhanced the attachment of the liver cells, altered their morphology, but did not prolong cell survival.

Vopr Virusol, 1976 Jul-Aug, (4), 456 - 61
{Production of J-96 cell culture chronically infected with herpes simplex virus and study of some of its properties}; Sovetova GP et al.; Comparative effectiveness of various methods for production of chronic infection with herpes simplex virus (HSV) in J-96 cell culture: inclusion into the culture fluid of the infected cultures of immune serum to herpes virus, immune serum to HSV-infected J-96 cells and frequent changes of the medium, is described . The advantage of the second method has been found . The chronically infected culture was resistant to superinfection with the homologous virus . In passages, when the chronically infected culture produced no active infectious virus, the portion of cells containing the virus antigen was 0.8% . In this culture interferon was found in a low titer . Morphological and histochemical studies also indicated some changes in chronically infected cultures as compared with the controls, namely, an increase in the number of spindle-shaped elements, thickening of the nuclear membrane, an increase in the DNA concentration . The culture has been designated JH and is in the 220th passage now.

Vopr Virusol, 1976 Jul-Aug, (4), 445 - 9
{Study of LPV oncornavirus reproduction in mixed cell culture}; Andzhaparidze AG et al.; Electron microscopy and mathematical analysis were used to determine the intensity of LPV oncornavirus production by a single cell in co-cultivated human diploid cells and cells of the continuous T-9 line . Maximum production of intracytoplasmic particles of A type was observed at 48 hours of cultivation, and extracellular virions at 96 hours . Mature virions of B type were more numerous than mature virions of C type in the mixed culture . On the whole the amolnt of mature virions was greater than that of immature ones, and the amount of intracytoplasmic A type particles was considerably greater than that of extracellular particles . By the total amount of production of all virus-specific structures and the two-wave pattern of virus production this mixed culture passaged at a ratio of HDC to T-9 cells 2000 : 1 resembled a culture of T-9 line . Thus, this study indicates that the infected HDC culture at later intervals of cultivation (96 hours) is a more active "producer" of LPV oncornavirus than the main line of T-9 cells or mixed HDC--T-9 culture.

Infect Immun, 1976 Jul, 14(1), 311 - 4
Rescue of vesicular stomatitis virus from homologous and heterologous interferon-induced resistance in human cell cultures by poxviruses; Thacore HR; In human cell cultures the ability of poxviruses to rescue vesicular stomatitis virus from human interferon-induced resistance was significantly more efficient than the ability to rescue it from simian interferon-induced resistance . The sensitivity of the poxvirus to interferon was not related to its ability to rescue vesicular stomatitis virus.

Vopr Virusol, 1976 Jul-Aug, (4), 453 - 6
{Antigenic characteristics of oncovirus persisting in continuous Syrian hamster cell culture}; Voevodin AF et al.; The antigenic properties of an oncornavirus persisting in a continuous Syrian hamster cell culture (X-100) were studied . By the mutual immunodiffusion test it was shown that virions and virion-producing cells contained a protein antigenically identical to the main structural protein of oncornaviruses type C of Syrian hamsters . The materials tested contained no "GS-1" antigens (species-specific antigenic determinants of the main structural protein of mammalian oncornaviruses type C) of murine, feline, simian viruses or group-specific antigens of Bitner and Mason-Pfiser viruses.

Cancer, 1976 Jul, 38(1), 157 - 65
An approach to the serodiagnosis of human lung cancer . Cell culture lines reactive as antigens with tumor patients' sera; Smith KO et al.; A solid-phase radioimmunoassay technique was used to quantitate antigen-antibody reactions between various human cell lines and lung cancer patients' sera . Four human fetal lung cell lines and four human tumor cell lines were more or less reactive as antigens . Failure to obtain exact correspondence between reactions with these cell lines indicates that more than one antigen may be required for detecting specific antibodies to the various lung tumor types . These results suggest that serum antibody detection might be a feasible approach to the immunodiagnosis of lung cancer at stages when the tumor masses are relatively small.

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