Brain Res, 1976 Jun 11, 109(2), 335 - 54 Biochemical differentiation of mechanically dissociated mammalian brain in aggregating cell culture; Honegger P et al.; Mouse and rat brain cells were dissociated by a simple mechanical sieving technique and studied in culture for the formation of aggregates and the activities of choline acetyltransferase, acetylcholinesterase, glutamic acid decarboxylase, tyrosine 3-monooxygenase, aromatic L-amino acid decarboxylase, catechol methyltransferase, and monoamine oxidase . Cells from fetal and neonatal tissue formed aggregates but not cells from tissue older than two days after birth . The pattern of development of enzyme activities in these aggregates varied with the age of starting tissue . The highest levels of specific activity for the neuron-specific enzymes were found after 3-4 weeks in culture for aggregates of cells derived from relatively undeveloped brains. Mycopathologia, 1976 Jun 4, 58(1), 9 - 12 Effect of acetone on production of aflatoxins and versicolorin pigments by resting cell cultures of Aspergillus parasiticus; Bennett JW et al.; Resting cell cultures of Aspergillus parasiticus were grown in medium containing four different concentrations of glucose, with and without acetone . In addition, the effect of different equimolar concentrations of acetone, acetic acid, ethanol, and sodium acetate was compared at two glucose levels . Aflatoxin and versicolorin pigment production increased in resting cell medium containing increasing concentrations of glucose . In the presence of glucose high concentrations of acetone (1.0 and 0.25 M) inhibited secondary biosynthesis and low concentrations of acetone (0.1, 0.025 and 0.01 M) stimulated secondary biosynthesis of aflatoxins and versicolorin pigments. Cancer Res, 1976 Jun, 36(6), 2065 - 9 Tumorigenicity in vivo and induction of malignant transformation and mutagenesis in cell cultures by adriamycin and daunomycin; Marquardt H et al.; The two anthracycline antitumor antibiotics, adriamycin and daunomycin, have been tested for tumorigenic activity, and the results confirm previous findings that they can induce mammary tumors in female rats receiving single i.v . doses . Both substances are highly potent in producing malignant transformation and mutation in mammalian cell systems in vitro . Their transformming activity is comparable to that of the potent carcinogen, N-methyl-N'-nitro-N-nitro-soguanidine . Actinomycin D, although similar to the anthracyclines in having high binding affinity for DNA, is only minimally effective in the same in vitro systems and its direct carcinogenic activity in vivo is moot . These results suggest that satisfactory correlations may be obtainable between tests for tumorigenicity in vivo, and assays for transformation and mutagenesis in vitro, and that adriamycin, and daunomycin may have carcinogenic potential in man. Chem Biol Interact, 1976 Jun, 13(3-4), 307 - 15 Effect of amino acids and inducers on the activity of the microsomal mono-oxygenase system in rat liver cell culture; Paine AJ; In rat liver cell culture both benzanthracene and phenobarbitone induce the activity of benzypyrene hydrxylase while only phenobarbitone increases NADPH cytochrome c reductase activity . Benzpyrene hydroxylase but not NADPH cytochrome c reductase activity is dependent on the amino acid concentration of the culture medium in a similar manner to the regulation of the hepatic hydroxylase activity by dietary protein intake in the whole animal . Of all the amino acids present in the culture medium, only tryptophan induced benzpyrene hydroxylase when added singly to the medium . However, tryptophan also induced the activity of the reductase suggesting that its inducing effect is unrelated to raising the concentration of all the amino acids of the culture medium . It is proposed that tryptophan may only be an inducer because the cells have low levels of tryptophan pyrrolase activity. J Nucl Med, 1976 Jun, 17(6), 503 - 7 Simple radiometric techniques for rapid detection of herpes simplex virus type 1 in WI-38 cell culture; D'Antonio N et al.; Two radiometric techniques were developed for detecting the presence of herpes simplex virus type 1 in stationary monolayers of the diploid cell line WI-38 . The time of detection was compared to that obtained from visual examination for cytopathic effects in the same cell line . Oxidation of 14C-1-glucose in infected and uninfected cells was determined by 14CO2 production, measured by an ionization chamber, and DNA synthesis was determined by 3H-thymidine incorporation, measured by scintillation counting . Compared to uninfected cells, infected cells showed a 23-26% reduction in 14C-1-glucose oxidation and a 355-498% increase in DNA synthesis 4-6 hr after infection . These changes in cellular metabolism were observed 14 hr before visible signs of cytopathic effects . The increase in DNA synthesis was completely inhibited by viral neutralization with herpes simplex antiserum . Increased DNA synthesis was observed 5 hr after infection with 10,000-3,200,000 TCID50 units of virus . These radiometric methods for the detection of viral effect on cellular metabolism are simple, fast, and objective. Acta Virol, 1976 Jun, 20(3), 253 - 6 Respiratory syncytial virus-specific RNA synthesis in primary monkey kidney cell cultures; Pal SR et al.; Primary rhesus monkey kidney (MK) cell cultures were inoculated with respiratory syncytial virus and treated or untreated with actinomycin D before pulse labeling with uridine-5-3H . The virus-specific RNA synthesis was noted at its peak in the nucleoplasm and possibly less so in the cytoplasm of infected cells . At 48 and 72 hours post-inoculation (p.i.), small fractions of available cells were synthesising virus-specific RNA with labeling index of 15% and 18% respectively . By 48 hours p.i . syncytia started appearing and a higher grain count in the cytoplasm of actinomycin D-treated infected cells was noted. Infect Immun, 1976 Jun, 13(6), 1642 - 6 In vitro differentiation and pH sensitivity of field and cell culture-attentuated strains of transmissible gastroenteritis virus; Hess RG et al.; Characteristics of four transmissible gastroenteritis (TGE) virus field strains (Miller, Purdue, Bl, and V203) and four cell culture-attenuated strains (Purdue, SH, CKp, and Bl) were studied to find methods of differentiation between the two groups of viruses . TGE field virus strains did not replicate as well as attenuated strains at 37 C and could not be passaged serially for more than four to six passages at 33 C . There were clear differences in plaque size when the strains were compared . Field strains had average plaque sizes ranging from 3.59 to 3.15 mm, whereas attenuated strains induced plaques that were larger than 4.2 mm . Variations were observed in stability of strains at pH 3.0 . Field strains and cell culture-attenuated strains CKp-270 and SH-114 were reduced in titer by about 1 log10 . A reduction of about 3 log10, however, was obtained with cell culture strains B1-300 and Purdue-113. Recent Adv Stud Cardiac Struct Metab, 1976 May 26-29, 12, 705 - 6 Experimental studies on cardiac arrhythmias with special reference to fibrillation in heart cell culture; Yoneda S et al.; Fibrillation-like beating of cardiac muscle cells in culture was induced by altering the concentrations of various ions . Fine structural changes of cell membrane and intercellular alteration of cardiac muscle cells appeared to be more prominent in cells with fibrilliation-like beating than in others . From the results of the present study, it may be concluded that fibrillation-like beating may occur in the presence of altered concentrations of certain ions, accompanied by fine structural changes in the cells. Recent Adv Stud Cardiac Struct Metab, 1976 May 26-29, 12, 683 - 8 Pleiotropic effect of serum on beating rat heart cell cultures and their modulation by hormones; Frelin C et al.; The multiple effects of serum on metabolic activities and macromolecular syntheses of heart cell cultures are discussed in this chapter . This pleiotropic response, which is linearly related to the amount of serum used, allowed us to quantitatively test the growth-promoting activity of different hormones . In addition, the possible mediation of the serum effects by cyclic nucleotides is considered. Acta Neuropathol (Berl), 1976 May 18, 35(1), 77 - 80 Inclusion bodies in brain cell cultures from Creutzfeldt-Jakob disease; Griffith JF et al.; Brain cell cultures were established from 20 patients with various forms of dementia and studied for evidence of virus induced alterations . Changes were detected in the cultured cells from 1 patient (L.C.) with the clinical and pathological diagnosis of Creutzfeldt-Jakob disease . These changes were present in the early passages of the brain tissue and were not seen in the cultures from the other cases. Am J Vet Res, 1976 May, 37(5), 567 - 72 Morphologic and physical characteristics of feline infectious peritonitis virus and its growth in autochthonous peritoneal cell cultures; Pedersen NC; Characteristic viral-type particles were seen in liver of kittens experimentally infected with the feline infectious peritonitis (FIP) agent . The particles were from 70 to 75 nm in diameter, with a central doughnut-shaped nucleoid 50 to 55 nm in diameter; numerous spikelike projections extended from their envelopes . Similar particles were seen by electron microscopy in peritoneal cell cultures derived from the peritoneal exudate of experimentally infected kittens, and viral antigens were identified in these cells by immunofluorescence . Cells and supernatant fluids from cultures containing these particles produced FIP when injected into the peritoneal cavity of kittens . The FIP agent is heat sensitive, ether labile, and relatively phenol resistant and is inactivated within 24 hours at room temperature . The FIP agent is inactivated by recommended viricidal concentrations of chlorhexidine and benzlkonium chloride. Clin Genet, 1976 May, 9(5), 527 - 32 Cystic fibrosis: a cell culture study on an adult patient population; Danes BS et al.; Skin fibroblast cultures from an adult population of cystic fibrosis (CF) patients have been studied to determine any possible genetic or clinical significance of the two classes described for cultured CF skin fibroblasts (Danes 1973) . On the basis of clinical course, the 46 adult patients from 43 unrelated families studied were divided into two groups (40 typical, 6 atypical) . The cultured fibroblasts from 37 of the 40 patients with typical CF were Class I (metachromatic, cystic fibrosis factor activity (CFFA) in the culture medium, and metabolic cooperation with normal fibroblasts), and the cultures from the remaining three patients were Class II (ametachromatic, no CFFA in the culture medium and no metabolic cooperation with metachromatic CF fibroblasts) . During the 4-year research period one of the 37 patients from Class I and all three Class II patients with typical CF succumbed . The cultured skin fibroblasts from two of the six patients who had an atypical course for CF were Class I and four were Class II . When the parents of three of these atypical CF Class II patients were studied, the cultured fibroblasts from one parent in each family in each family were Class I and the other Class II . The affected offspring from such Class I-II matings may represent genetic compounds. Shika Rikogaku Zasshi, 1976 May, 17(38), 145 - 61 {Studies on the cytotoxicity of silver alloys be means of cell culture (author's transl)}; Mizutani H; In order to investigate biocompatibility of silver alloys, which is widely used in Japan, L strain cells were brough contact with the alloys . Results were assessed by cell multiplication rate calculated from counting cell nuclei number per milliter of medium and morphological observation . The materials used were two from of silver-tin-zinc alloys, one form of silver-tin-zinc-cadmiumalloy and two forms of silver-copper alloys . Copper-zine alloy, which is reported to be highly cytotoxic, was alsoutilized as a positive control . Following results were obtained: 1) Ingot specimen of these alloys showed cytotoxicity, Silver-tin-zinc alloy, silver-tin-zinc-cadmium alloy and silver-copper alloy containing 10% or less of copper showed intense cytotoxicity initially, with diminishing cytotoxic action with time . On the otherhand, silver-copper alloy containing 20% or more of copper showed persistent cytotoxicity . Copper-zinc alloy showed intense cytotoxicity . 2) Cast specimen of these alloys showed increasing cytotoxicity with time campared to their ingot specimen . The results are seemed to owe much to inclusion of toxic substances from the alloy and investment material or alteration of surface characteristics of the alloys due to casting procedure . 3) Morphological observation did not differ from the results of cell nuclei counting . It is expected that the present results could give a clue on animal experiments or clinical use from the view point of biocompatibility of silver alloys. J Microsc, 1976 May, 107(1), 79 - 83 An improved culture flask for photographic and visual observation of living cell cultures; Fox CH et al.; A new type of culture vessel is described, identical in shape to the classic T15 vessel but with the advantage of optical surfaces that allow photography at medium resolution (with numerical apertures of 0-60-1-0) . Details of flask manufacture are given. Vopr Virusol, 1976 May-Jun, (3), 371 - 9 {Several methodologic problems in the control of cell cultures}; Demidova SA et al.; Some human and animal continuous cell lines as well as primary cell cultures were examined by karyological, electron microscopial, virological and molecular biological methods and also by the electrophoretic motility of glucose-6-phosphate dehydrogenase (G-6-PDG) in polyacrylamide gel . All human and animal continuous cell lines were shown to contain mycoplasma, 17-to contain intracytoplasmic particles of type A oncornaviruses, 5 -- type B oncornaviruses similar to Mason-Pfizer virus, 8 -- paramyxoviruses, 2 --oncornaviruses type C . A high molecular RNA with sedimentation constant 64--70 S was found in oncornaviruses isolated from cell cultures . Intracellular virus or subviral structures were detected by association of the reverse transcriptase activity with high molecular RNA . The presence in the cell cultures of marker chromosomes of HeLa cells, the absence in these cultures of Y chromosomes, the presence of the G-6-PDG enzyme with type A motility indicate the possibility of contamination of human continuous cell lines with HeLa cells. J Lipid Res, 1976 May, 17(3), 285 - 8 Rapid screening of lipid metabolism in monolayer cell cultures; Dosado EA et al.; Monolayer cell cultures grown on coverslips in the presence of radioactive lipid precursors were embedded in silica gel layers for extraction and resolution of the labelled products directly by thin-layer chromatography . The method permits rapid screening of lipid metabolism in tissue cultures with a small number of cells. Trop Anim Health Prod, 1976 May, 8(2), 97 - 101 Application of the indirect fluorescent antibody test for diagnosis of Theileria hirci infection of sheep: using cell culture schizont antigen; Hawa N et al.; The indirect fluorescent antibody test was applied for detection of circulating antibodies in sheep as a result of Theileria hirci infections . A schizont antigen was prepared from an in vitro culture suspension of lymphoid cells infected with T . hirci macroschizonts . The peak antibody titre of 1/8, 192 was reached 24 days after the initial antibody rise in the sheep experimentally infected by means of Hyalomma anatolicum anatolicum ticks. In Vitro, 1976 May, 12(5), 352 - 62 Growth and characterization of human skin epithelial cell cultures; Freeman AE et al.; In 129 of 140 attempts, human skin cells were successfully cultured on the dermal collagen bed of sterile, dead pigskin . Diploid epithelial cells grew selectively on the collagen bed; fibroblasts grew on the glass surfaces of the culture dishes . The cultures could be subdivided physically up to six times at a 1:2 split ratio, but at least 24 to 48 cell generations were produced over the months the cells could be carried . Much of the cell multiplication resulted in maturation into distinct basal, squamous, granular, and keratinized cell layers . The cultured cells were considered epithelial because of their shape, possession of intercellular bridges, desmosomes and tonofibrils, and because they formed maturating epithelium in vitro and upon transplantation back to the original human donor . As the cells grew they digested the pigskin collagen, thus producing clear zones that could be used to monitor and quantitate cell growth . Multiplication of epilthelial cells, rather than migration, was indicated by mitotic figures in colchicine-treated cultures and by DNA synthesis. Biull Eksp Biol Med, 1976 May, 81(5), 550 - 2 {Hexokinase activity in the soluble fraction of the nucleus and cytoplasm in cell cultures infected with human adenoviruses types 6 and 12}; Ageenko AI et al.; A study was made of the activity of hexokinase in the soluble fraction of the nucleus and cytoplasm of fibroblasts of rat embryos (primary cultures) during contact with infectious (A6) and oncogenic (A12) human adenoviruses . A high activity of the enzyme was seen in the cytoplasmic fraction in comparison with the nuclear one both in the infectious adrenovirus of type 6 this value differed from the normal and in the experimental samples . With the action of the normal but insignificantly . Marked changes in the enzyme activity were observed in case of cell contact with the oncovirus . They occurred both in the nucleus and in the cytoplasm the first days of the virus inculcation, increasing gradually with the lapse of tiay; these disturbances were much greatert in the cytoplasm than in the nucleus . It is supposed that the changes revealed possibly associated with the impossibility to regulate the cell proliferation process. Rev Asoc Argent Microbiol, 1976 May-Aug, 8(2), 45 - 53 {Interference associated with cell cultures chronical by infected with the Junin virus}; Help GI et al.; Supernatants from Vero cells persistently infected with Junin virus interfered with cytolitic and lethal activities of standard virus . Two Vero cell sublines, chronically infected with Junin virus named VRJ1 and VRJ3, were obtained after prolonged cultivation of cells which survived primary infection . VFJ1 was maintained over a period of 48 days, by biweekly serial transfers while VRJ3, similarly treated, was cultivated for 385 days . One of the characteristics of these cell lines was resistance against superinfection with homologous virus that ordinaily produced CPE and plaques in normal Vero cells; the cells were then considered chronically infected . Supernatants taken at different cell passage level were tested for its interference activity after centrifugation to eliminate floating cells and debris . The degree of CPE intensity caused by inoculation of Vero cells with 10(4), 10(5) or 10(6) TCID 50 of standard virus was markdely deppressed (Figure 1) by coinfection with supernatant from passage 3 of VRJ3 (VRJ1p1), VRJ1p1 supernatant also had interference activity as shown by coinfection with standard virus and expressed by plaque forming inhibition(Table 1) . The plaque production of standard virus was inhibited by coinfection with VRJ1p1 supernatant which did not originate plaques when inoculated alone . The interference capacity of VRJ1p6 supernatant was reduced (Table 1) coincidentally with the formation of 55 PFU/ml . Interference activity was neutralized by Junin specific antiserum and inhibited by chloroform treatment . When Vero cells infected with VRJ1p6 supernatant were challenged with standard virus 72 hs later, an inhibition of 98% was achieved (Table 2) in contrast with value of 35% showed in Table 1. Osterr Z Onkol, 1976 May, 3(1-2), 3 - 8 Studies on kinetics of DNA synthesis in CV-1 cell cultures infected with different multiplicities (MOI) of Herpes simplex virus type 2 (HSV-2); Dostal V et al.; Infection of CV-1 cell cultures with HSV-2 at MOI 5 respectively 1PFU/cell resulted in markedly different patterns of DNA-synthesis . Isolation and separation of cellular and viral DNA on CsCl equilibrium density gradients during the "late" phase after infection with 5PFU/cell revealed a rapid increase in synthesis of virus-specific DNA (which banded at density q25 = 1.729 g/ccm) while synthesis of host cell DNA (banding at 1.705 g/ccm) was constantly inhibited . 15 hours after infection and incubation with labelled medium, around infection and incubation with labelled medium, around 75% of total isolated DNA was virus-specific . On lowering the MOI to 1 PFU/cell, however, synthesis of host cell DNA continued and was even partially stimulated during the late phase whereas synthesis of virus-specific DNA advanced only slowly . 16 hours after infection, approximately 25% of the total assayed after infection, approximately 25% of the total assayed DNA was virus-specific and the amount of host cell DNA approached values of uninfected control cells . 24 hours after infection and incubation, virus specific DNA rose to approximately 45% of overall DNA assayed, and synthesis of host cell DNA was completely inhibited . However, infectivity rose constantly and reached 106.8 TCD 50/ml at 22 hours p.i . These findings were independent of passage number of CV-cell culture, and there were no alterations in karyotype and morphological behaviour of the cells. Cell, 1976 May, 8(1), 87 - 93 High frequency variation in mammary tumor virus expression in cell culture; Parks WP et al.; Clonal derivatives of C3HMT murine mammary cell lines in culture demonstrate conversion of mammary tumor virus (MMTV) expression at a rate of appriximately 6 per 100 clones . This alteration is largely unidirectional from a relatively high level (MMTV(H)) to a 10 fold lower level (MMTV(L)) . This high rate of MMTV(L) variant conversion is in apparent contrast to the presumably mutational rate (approximately 3 per million cells) that governs development of resistance to 6-thioguanine (TG) in the same mammary cells . In somatic cell hybrids between different MMTV TGr clones and mouse or hamster TK- cells, expression of constitutive levels of MMTV and responsiveness to dexamethasone induction is dominant . Thus MMTV expression is regulated by at least two levels of positive control, constitutive expression and glucocorticoid stimulation, but the former is subject to a high rate of variant formation. Am J Med Technol, 1976 May, 42(5), 158 - 65 Selection of cell culture systems for virus isolation; Cooney MK; A survey of cell culture systems for virus isolation is presented . Because there is not single cell culture system which will support the many viruses that may be encountered in clinical specimens, the characteristics and susceptibility of primary, diploid, and continuous cell cultures are reviewed . The primary cell culture system should be susceptible to infection with myxoviruses, paramyxoviruses, adenoviruses, and Coxsackie B viruses, since these are not consistently recognized in diploid cell cultures . Conversely, rhinoviruses, cytomegalovirus and varicella-zoster virus may be isolated only in diploid cell cultures . Upon consideration of expected viruses, and cell cultures available for isolation of these, one can choose a combination of a primary and a diploid cell system for virus isolation which will assure detection of most human virus groups known . The usefulness of continuous cell culture systems is generally limited to a very few specific viruses. Proc Soc Exp Biol Med, 1976 May, 152(1), 61 - 3 Early events in the lytic infection of primary mouse kidney cell culture with polyoma virus . The effect of various input multiplicities; Brown A et al.; Early polyoma (Py) virus-specific RNA synthesis was examined in cells infected with different concentrations of Py-virus . The effect of various multiplicities of infection (m.o.i.) on the rate of Py-RNA synthesis is different at 30 hr as compared to 65 hr . Thirty hours after infection at 27degrees, in the presence of 5-fluoro-2-deoxyuridine (FdU), an increase in input multiplicity was not associated with a quantitatively commensurate increase in the amount of virus-specific RNA synthesized . At 65 hr, the amount of viral RNA synthesized was roughly proportional to the number of infecting virus particles. Biochim Biophys Acta, 1976 Apr 23, 428(2), 456 - 65 The appearance of an ornithine decarboxylase inhibitory protein upon the addition of putrescine to cell cultures; Fong WF et al.; Quiescent, contact inhibited H-35 rat hepatoma cell cultures maintained in minimal essential medium contain a very low level of ornithine decarboxylase activity . However, 2 h after the addition of 10% fetal calf serum to the culture medium, the enzyme activity increases by approx . 100-fold . This increase can be completely inhibited by the simultaneous addition of 10(-2) M putrescine . The presence of putrescine elicits the appearance of an intracellular inhibitor of ornithine decarboxylase . This inhibitor of ornithine decarboxylase has a molecular weight of 26500, is sensitive to the action of chymotrypsin and is noncompetitive with respect to ornithine . The intracellular appearance of this inhibitor is sensitive to cycloheximide but is only partially inhibited by actinomycin D. J Biol Chem, 1976 Apr 10, 251(7), 2030 - 6 Assembly of the sarcoplasmic reticulum . Biosynthesis of the adenosine triphosphatase in rat skeletal muscle cell culture; Holland PC et al.; Temporal patterns of biosynthesis of the Ca2+ + Mg2+-dependent adenosine triphosphatase of sarcomplasmic reticulum were obtained from studies with primary cultures of rat skeletal muscle cells . Rates of synthesis at various stages of differentiation were estimated from the incorporation of tritium-labeled leucine into the ATPase . Cells were solubilized with detergent, and newly synthesized ATPase was isolated from cells by antibody precipitation in the presence of carrier ATPase . Radioactivity incorporated into the ATPase was determined after gel electrophoresis of the precipitates and counting of gel slices containing the ATPase band . In Dulbecco's modified Eagle's medium containing 10% horse serum and 0.5% chick embryo extract, mononucleated myoblast cells began to form multinucleated myotubes after about 50 hours in culture . Prior to fusion little ATPase synthesis was detectable; during fusion the ATPase was synthesized at an accelerating rate for a period of about 30 hours . The rate of synthesis levelled off after about 90 hours coincident with termination of fusion . In Dulbecco's modified Eagle's medium containing 20% fetal calf serum and 8% embryo extract, the onset of fusion was delayed for 30 to 40 hours . In this medium biosynthesis of the ATPase was also delayed so that biosynthesis of the ATPase appeared to be correlated with fusion of muscle cells . Cells cultured in Culbecco's modified Eagle's medium containgin 10% horse serum, but only 60 muM Ca2+, proliferated but did not fuse . Under these conditions, synthesis of the ATPase was measurable at 50 to 60 hours, and the rate of synthesis accelerated until 120 hours when it declined . Under all conditions degradation of the ATPase occurred with a half-life of 20 hours whereas the half-life of total protein degradation was 40 hours . Synthesis of the sarcoplasmic reticulum ATPase, like that of a number of other muscle-specific proteins, is greatly accelerated as myoblasts fuse and differentiate into myotubes . Fusion is not essential for this phenomenon, however, although it is normally concomitant with it. Proc Natl Acad Sci U S A, 1976 Apr, 73(4), 1212 - 6 Transepithelial transport in cell culture; Misfeldt DS et al.; In cell culture a kidney epithelial cell line MDCK, forms a continuous sheet of identically oriented asymmetrical cells joined by circumferential occluding junctions . The reconstructed epithelial membrane has transport and permeability qualities of in vivo transporting epithelia . The cell layer can be readily manipulated when cultured on a freely permeable membrane filter and, when placed in an Ussing chamber, electrophysiological measurements can be taken . In the absence of a chemical gradient, the cell layer generates an electrical potential of 1.42 mV, the apical surface negative . It is an effective permeability barrier and lacks significant shunting at the clamped edge, as indicated by a resistance of 84 ohms-cm2, which increased when bulk flow from basolateral to apical was induced by an osmotic gradient or electroosmosis . The MDCK cell layer is cation selective with a relative permeability ratio, PNa/PCl, of 1.7 . Net water flux, apical to basolateral, was 7.3 mul cm-2 hr-1 in the absence of a chemical gradient . The morphological and functional qualities of a transporting epithelium are stable in cell culture, and the potential use of a homogeneous cell population in cell culture would enhance studies of epithelial transport at the cellular and subcellular levels. Mutat Res, 1976 Apr, 40(2), 125 - 30 Chromosome analyses in cell cultures of the Chinese hamster after application of cadmiumsulphate; Rohr G et al.; Cell cultures of a Chinese hamster cell line were treated with CdSO4 in concentrations of between 10(-4) and 10(-8) mol/l for different time periods . After a treatment of 16 h the mitotic index was reduced . Strong stickiness and pycnosis of chromosomes occurred at the highest concentrations . A treatment period of 3 h with concentrations of 10(-5) and 10(-4) mol/l without additional application of Colcemid and hypotonic solution yielded a stathmokinetic effect . The mitotic index increased, mitoses were blocked in metaphase stage and "initial C-mitoses'' and "C-mitoses'' were present . Structural chromosome aberrations were present in the recovery period of more than 12 h following a treatment of 1 h with 10(-4) mol/l CdSO4 . The observed aberrations were mainly of the chromatid type. Mutat Res, 1976 Apr, 40(2), 107 - 18 The effect of insecticides on Chinese hamster cell cultures; Mahr U et al.; The effect of p,p'-isomers of DDT and its derivatives DDD, DDE and DDA on Chinese hamster cells in culture was studied . At different concentrations and various times of treatment the proliferation rate was inhibited most strongly by DDD and DDT, whereas DDE exhibited a markedly weaker influence . DDA was the least toxic compound of the four . The cytogenetic effects were also different . Again, DDA induced the least damage . Only enhanced gap rates but no chromosome breaks were observed . DDE was more active, and higher break rates occurred . DDD and DDT were by far the most damaging compounds, and they raised the gap and break rates markedly . However, no induction of configuration anomalies was found in any experiment . Chronic treatment of the cells for 3 months with DDT at 8 ppm did not alter the proliferation rate, the sensitivity to acute treatment with higher DDT concentrations or the chromosomal aberration rates . The results are discussed in relation to the relevance of differential pesticide effectivity in organs of higher animals and man. J Exp Zool, 1976 Apr, 196(1), 1 - 12 Hormone induction of specific protein synthesis in midpregnant mouse mammary cell culture; Ceriani RL; Monolayer primary cell cultures of midpregnant mouse mammary cells were subjected to hormone stimulation under strictly defined conditions . Hormonal response was measured in terms of increase in rate of synthesis of mouse casein, using a double antibody precipitation technique . Cells stimulated by insulin plus prolactin plus cortisol plus estradiol plus progesterone showed a marked increase in rate of mouse casein synthesis over the controls . This specific product synthesis, which remains inducible in these cells for at least ten days, was detected either by labelled phosphoric acid or labelled amino acid incorporation . The mouse casein synthesized was identical, as judged by the identification techniques used, to that of mouse milk . Mouse midpregnant mammary explants in organ culture require insulin plus prolactin plus cortisol to express their full lactogenic capabilities . Nevertheless, when the same cells are dispersed and grown in monolayers they require ovarian steroids to elicit a lactogenic response as shown in this study . Ovarian steroids, therefore, are necessary in lactogenesis, although the fundamental nature of their action remains to be established. Br J Exp Pathol, 1976 Apr, 57(2), 211 - 6 Evidence for the multiplication of hepatitis B virus in "oval cell" culture originated from human embryonic liver; Watanabe M et al.; Growth conditions fof human oval cells (immature hepatocytes),evidence of hepatitis B (HB) antigen synthesis in oval cells as revealed by immunofluorescent staining and successful passage of such an agent in the culture fluid up to the 4th passage are described . The results have been proved to be readily reproducible with different inocula . The oval cells used in these experiments were defined as small round cells, with scant cytoplasm, vesicular nuclei and small nucleoli, vitally stained with indocyanine green and synthesizing alpha-foetoprotein but no albumin. Jpn J Med Sci Biol, 1976 Apr, 29(2), 77 - 90 Studies on the interaction between coxsackievirus A9 and HeLa cells . II . Mode of growth of coxsackievirus A9 in HeLa cell cultures and the effect of sulfated polysaccharide on plaque formation; Matsumoto M et al.; For the purpose of clarifying the mechanism of plaque formation in HeLa cell cultures by coxsackievirus A9, which does not show definite CPE in fluid cultures, we investigated the growth pattern of the virus in HeLa cells, comparing plaque (HeLA)-forming and non-plaque (HeLa)-forming viruses . It was revealed that the yield of both viruses per cell was nearly the same, but non- plaque (HeLa)-forming virus was far less efficient in infecting HeLa cells . Dextran sulfate was effective in releasing more virus from cells, when HeLa cell cultures were infected with plaque (HeLa)-forming virus, but not in cultures infected with non-plaque (HeLa)-forming virus . From these experimental results, the mechanism by which plaques are formed in HeLa cell cultures by coxsackievirus A9 was discussed. Jpn J Med Sci Biol, 1976 Apr, 29(2), 67 - 76 Studies on the interaction between coxsackievirus A9 and HeLa cells . I . Plaque-forming ability of coxsackievirus A9 in HeLa cell cultures; Matsumoto M et al.; Most of the coxsackievirus A9 (CA 9 virus) including the prototype strain formed plaques in HeLa cell monolayers under agar overlay, although they showed little or no cytopathogenicity under fluid medium . These viruses were isolated or passaged in primary cynomolgus monkey kidney (MK) cell cultures, and the infectivity of any strain in terms of plaque-forming units was much higher in MK cells than in HeLa cells, even after plaque purification of the virus in HeLa cell cultures . CA 9 virus contained in the original throat swabs as well as some clones obtained by plaque purification in MK cells failed to form plaques in HeLa cells, but virus preparations obtained after several undiluted passages through MK cells included plaque-formers in HeLa cells, suggesting that such plaque (HeLa)-forming viruses may have developed at a certain rate during multiplication of the original non-plaque (HeLa)-forming virus population in MK cells . Out of four lines of HeLa cells examined, two, including a clonal line S3, failed to support plaque formation by CA 9 virus. Biochim Biophys Acta, 1976 Mar 25, 428(1), 233 - 9 Endogenous cyclic AMP in thyroid cell culture . Effect of thyroid-stimulating hormone and dibutyryl cyclic AMP; Verrier B et al.; We have studied the variations of endogenous cyclic AMP levels in thyroid cells cultured over a period of 7 days in several conditions: in the presence of thyroid-stimulating hormone or dibutyryl cyclic AMP which both promote the aggregation of isolated cells into follicles, and in their absence when cells develop as a typical monolayer . In follicle-forming cells, the cyclic AMP level was found to rise during the first day of culture, then to fall rapidly . In monolayer-forming cells, the cyclic AMP content slightly increases attaining the same level as found in other cells at the fourth day, which remains stable till the seventh day . We have investigated the response of these cells cultured in the presence of dibutyryl cyclic AMP retain the capability of increasing their cyclic AMP concentration whereas monolayer-forming cells do not preserve this quality of thyroid cells. Biotechnol Bioeng, 1976 Mar, 18(3), 363 - 82 Autoclavable low cost serum-free cell culture media: the growth of established cell lines and production of viruses; Keay L; Five cell lines (BSC-1, CHO, Balb/c 3T3, HeLa, and KB) have been grown in serum-free media for several months with regular schedules of media changing and subculturing . The medium found to be successful in all cases was MEM-alpha (without the ribosides and deoxyribosides) supplemented with 1% bacteropeptone, although simple MEM (minimum essental medium (Eagle) with bacteropeptone (BP) gave fairly good growth in the case of BSC-1 and 3T3 cells . The addition of insulin was necessary for CHO, 3T3, HeLa, and KB cells . Only the BSC-1 cells grew exclusively as a stationary suspensions and the 3T3 cells growing as a combination of monalayer and suspension depending on the age of the culture and the nature of the growth surface . SV40 was produced in BSC-1 cells grown and infected in the MEM-alpha, bactopeptone medium and adenovirus-2 was produced in spinners of HeLa and KB cells grown in MEM-alpha, bactopeptone, PVP-360, and insulin . The yield of virus and infectivity of the viruses produced were about the same as those produced in conventional serum-containing systems. Kosm Biol Aviakosm Med, 1976 Mar-Apr, 10(2), 58 - 63 {Results of mammalian cell culture exposure on artificial earth satellites}; Sushkov FV et al.; The paper presents the results of an exposure of cells of the Syrian hamster strain VNK-21 to space flight effects . In contrast to the cell culture kept in a thermostat at 29 degrees C, the cell culture that was maintained in thermally uncontrolled conditions developed noticeable structural and physiological changes induced by suboptimal temperatures . It was concluded that a 6-day exposure to weightlessness exerted no adverse effect on mammalian cells in vitro and produced no stable structural or physiological changes . Some changes that were detected in the cell culture--faster ageing, stable tendency to an increase of the number of cells with enlarged nuclei, an increase of the mitotic index at an early stage of cultivation--need further investigation. J Natl Cancer Inst, 1976 Mar, 56(3), 561 - 70 Invasive behavior between sarcoma and fibroblast populations in cell culture; Abercrombie M et al.; The mutual invasion in culture of a population of standard fibroblasts (chick embryo) and a population of cells from a transplantable mouse sarcoma (MC)M, BAS/56, or 311) or of neontal mouse fibroblasts has been estimated quantitatively . We arranged the confrontation of the pairs of populations by placing primary explants near each other . After fixation, the distance the cells had migrated from each explant was sampled in the space between the explants where they met and at the sides of the explants where they migrated freely . Measurements of nuclear overlap and orientation were also made . In the sarcoma as in the fibroblast population, homologous contact inhibition of movement probably produced an oriented migration from the explants before the populations met . Abot 12-24 hours after, mutual invasion was considerably greater in the sarcoma versus fibroblast than in the fibroblast versus fibroblast experiments . It is proposed that this difference was due to a difference of heterologous contact inhibition in the two types of experiment. Cancer Res, 1976 Mar, 36(3), 1074 - 6 Isonucleolinosis in cell cultures of human meningiomas; Zankl H et al.; In cell cultures of 13 human meningiomas the internal structure of the nucleolus was stained by the toluidine blue-molybdate method and compared with the karyotype of the tumors . Although some of the meningiomas had lost or gained one or more chromosomes and had undergone structural aberrations, all of them showed isonucleolinosis, which is normally found only in cells with normal karotype . It seems possible that the occurrence of iso- or anisonucleolinosis is not a specific sign of euploidy or aneuploidy, but of benignity or malignancy of the examined tissue. J Cell Biol, 1976 Mar, 68(3), 411 - 9 The smooth muscle cell . III . Elastin synthesis in arterial smooth muscle cell culture; Narayanan AS et al.; Primate arterial smooth muscle cells and skin fibroblasts were examined for their ability to synthesize elastin in culture . In the presence of the lathyrogen beta-aminopropionitrile, the smooth muscle cells incorporate {3H}lysine into a lysyl oxidase substrate that was present in the medium and associated with the cell layer . A component having a mol wt of 72,000 and an electrophoretic mobility similar to that of authentic tropoelastin was isolated from the labeled smooth muscle cells by coacervation and fractionation with organic solvents . In the absence of beta-aminopropionitrile, long-term cultures of smooth muscle cells incorporated {14C}lysine into desmosine and isodesmosine, the cross-link amino acids unique to elastin . In contrast, no desmosine formation occurred in the fibroblast cultures . These characteristics demonstrate that arterial smooth muscle cells are capable of synthesizing both soluble and cross-lined elastin in culture. Vopr Virusol, 1976 Mar-Apr, (2), 211 - 6 {Detection of cell culture tumorigenic activity by heterotransplantation into hamster cheek pouch tissue using immunodepressants}; Avakova AN et al.; Different strains of diploid cells were studied experimentally in Syrian hamsters by heterotransplantation into cheek pouch tissue for detection of their tumorigenic activity . Cortisone and antilymphocyte serum were used as immunodepressors . The results showed that the use of antilymphocyte serum increased considerably the sensitivity of the method of determination of cell culture tumorigenic activity. Cancer Res, 1976 Mar, 36(3), 947 - 51 Dimethyl sulfoxide-induced enhancement of 7,12-dimethylbenz(a)anthracene metabolism and DNA binding in differentiating mouse epidermal cell cultures; Yuspa SH et al.; Mouse epidermal cells in primary culture differentiate rapidly over a 2-week period leading to keratinization and sloughing of most of the plated cells . Cell replication was partially synchronized in these cultures with peaks of DNA synthesis at the 2nd and 8th day . The ability of epidermal cells to metabolize 7,12-dimethylbenz{a}anthracene and the subsequent binding of activated products to epidermal DNA was a function of the culture time . Constitutive and induced levels of aryl hydrocarbon hydroxylase in cells cultured for 10 days were half of those in cells grown for 3 days . Likewise, 7,12-dimethylbenz{a}anthracene binding to epidermal DNA was two- to fourfold lower in 10-day than 3-day cultures . This decrease in metabolism and binding between 3-day and 10-day cultures could be eliminated by the inclusion of 1.25% dimethyl sulfoxide in the culture medium during the entire culture period. Cancer Lett, 1976 Mar, 1(4), 231 - 5 Carcinogen-induced DNA repair in primary rat liver cell cultures; a possible screen for chemical carcinogens; Williams GM; Primary rat liver cell cultures were exposed to a direct acting carcinogen, methyl methanesulfonate, and procarcinogens requiring metabolic activation, aflatoxin B1 and B2 . DNA damage by these agents was evidenced by the induction of DNA repair, measured as unscheduled DNA synthesis . The sensitivity of these cultures to the potent porcarcinogen aflatoxin B1 indicates that this system may be adapted for screening suspected chemical procarcinogens, and for investigating the relationship between metabolic activation of procarcinogens, DNA damage, DNA repair, and carcinogenicity. Vopr Virusol, 1976 Mar-Apr, (2), 199 - 203 {Effect of 2-deoxy-d-glucose on enterovirus reproduction in HEp-2 cell cultures}; Shirobokov VP; The influence of 2-deoxy-d-glucose (2DG) on reproduction of some enteroviruses was studied . When 2DG was added to carbohydrate-free medium . It exerted a marked inhibiting effect on reproduction of poliovirus type I (virulent and attenuated variants) and Coxsackie B1, B2, B3, B5 and B6 viruses . The agent was inactive for virulent and attenuated poliomyelitis type II viruses . Poliomyelitis type III and Coxsackie B4 viruses were shown to be incable of multiplication in carbohydrate-free medium when the maintenance medium in cell cultures was lactalbumin hydrolysate in Hank's solution without-glucose . The inhibiting effect of 2DG on sensitive enteroviruses was irreversible and manifest at a concentration as low as 0.1 mg/ml . The effect of the agent was directed to the active stages of intracellular enterovirus synthesis . The possible mechanism of inhibition of enterovirus reproduction in the presence of 2DG is discussed. Mol Cell Endocrinol, 1976 Mar, 4(4), 263 - 70 Steroidogenesis and extracellular cAMP accumulation in adrenal tumor cell cultures; Schimmer BP et al.; ACTH stimulated steroidogenesis and cAMP (adenosine 3',5'-monophosphate) accumulation in an adrenocortical mouse tumor cell line (clone Y1) with Kd values which differed by more than one order of magnitude (5.2 X 10(-11) M and 7 X 10(-10) M, respectively) . All of the cAMP formed in response to added ACTH appeared extracellularly in 5- or 30-min incubations . ACTH, at 5 and 10 muU/ml, stimulated steroidogenesis to 25% and 40% of maximum activity; and increased the extracellular accumulation of cAMP 1.4-fold and 2.3-fold, respectively . The effects of ACTH appeared to be via an action on intracellular ATP, specific for cAMP and dependent on an ACTH-sensitive adenylate cyclase system . These observations indicate that ACTH increases cAMP accumulation in Y1 cells at virtually all steroidogenic concentrations and suggest that cAMP is an essential component of ACTH-stimulated steroidogenesis. Br J Cancer, 1976 Mar, 33(3), 299 - 306 Human preleukaemia cell culture studies in sideroblastic anaemia; Senn JS et al.; Cell structure abnormalties are found in acute leukaemia and preleukaemic states . Studies on bone marrow cells and peripheral leucocytes of 4 patients with idiopathic acquired sideroblastic anaemia showed patterns in cell culture similar to those reported in acute leukaemia: 2 of these patients later developed leukaemia . Other patients with idiopathic, secondary or congenital sideroblastosis showed no such cell culture abnormalities, and none developed leukaemia . Studies such as this suggest that cell culture methods detect altered cellular function preceding overt leukaemia and that these abnormal findings may be helpful in the evaluation of patient groups with an increased incidence of leukaemia. Biull Eksp Biol Med, 1976 Feb, 81(2), 237 - 9 {Changes in the mitotic regime of a cell culture under the influence of sensitins}; Iakimenko LN; A study of the effect of three types of lyophilized sensitin preparations on cell culture of human amnion showed an increase in the amount of pathological mitoses, arrest of division at the metaphase and the appearance of chromosome adhesions absent in the control culture . These changes pointed to destructive action of the preparations under consideration on chromosomes and achromatine spindle, and from the author's point of view, characterized toxic properties of sensitin. Antibiotiki, 1976 Feb, 21(2), 174 - 7 {Primary cell cultures of leukosis P-388 as a possible model for the screening of antitumor substances}; Ivanitskaia LP et al.; A substrain of the ascitic leucosis P-388 was obtained as a result of interchanging passages of P-388 leucosis cells in the primary cultures and abdominal cavity of mice . The tumor cells of the ascitic leucosis P-388 multiplied in the primary suspended culutres as well as in vivo . The substrain lost its hemorrhagic properties . The content of DNA and RNA in the primary cultures of P-388 doubled every 16-18 hours and the number of the cells doubled every 24-26 hours . The cells of the adapted substrain of P-388 grew also in the semiliquid agarized medium forming compact colonies by the 4th-5th day of cultivation . The primary suspended cultures of P-388 were highly sensitive to cytostatics and in particular to vinblastin and kolchamine (alkaloids) . In this connection they were recommended for prescreening antitumor compounds. J Med Genet, 1976 Feb, 13(1), 34 - 7 Behaviour of cell cultures from human amniotic fluid; Hasholt L; The growth pattern of cell cultures originating from 11 amniotic fluid specimens have been observed . From each specimen 2 to 12 primary cultures were set up . In most cases growth started simultaneously in the primary cultures originating from one sample . The primary cultures lasted from 7 to 30 days . A variation was found both between cultures from different pregnancies as well as among cultures obtained from single amniotic fluids . The growth period from setting up the cultures until harvest of the cell lines for biochemical analysis ranged from 20 to 54 days . No connexion was noticed between the time spent in primary culture and the behaviour of the cell line before harvest . The effects of two types of serum (fetal calf serum and pooled human serum) on the behaviour of the cultures were compared . The cells grown in human serum were harvested a few days before those grown in fetal calf serum . The influence of different batches of medium was also examined; no significant effect of the growth pattern was found . The appearance of epithelial-like and fibroblast-like cells in cultures from 6 specimens was observed concurrently . At the time of harvest the cell lines originating from the same amniotic specimen contained the cell types in different proportions. J Protozool, 1976 Feb, 23(1), 109 - 15 Fine-structural aspects of microgametogenesis of Eimeria magna in rabbits and in kidney cell cultures; Speer CA et al.; The fine-structural aspects of development of microgamonts of Eimeria magna were studied in kidney cell cultures and in experimentally infected rabbits . Spheroidal masses of gamont-like cytoplasm containing ribosomes, polyribosomes, and amylopectin granules were found within the parasitophorus vacuole; these bodies were apparently pinched off the surface of the gamont . Nucleoli were present in the early stages of nuclear division but disappeared as development proceeded. J Clin Microbiol, 1976 Feb, 3(2), 96 - 101 Prophylactic immunization of humans against rabies by intradermal inoculation of human diploid cell culture vaccine; Cox JH et al.; The antirabies human diploid cell vaccine produced by 1'Institute Merieux, Lyon, France, was administered intradermally to 35 high-risk volunteers using 0.2-ml amounts and various immunization schedules . Three groups never before vaccinated against rabies developed virus-neutralizing antibodies, the titer of which was dose dependent . A single injection stimulated the formation of antibodies . Four inoculations induced the highest antibody levels and the longest persistence of antibody . The administration of a single intradermal booster inoculation was sufficient, even in the case of low-persisting antibody, to elicit a rapid increase of antibodies to high levels . A primary inoculation course of two injections induced a sufficient antibody level which, in case of exposure, could apparently be rapidly elevated by a 0.2-ml intradermal booster inoculation . Adverse side reactions were observed in 7 of 14 individuals after a 1- or 1.5-year intradermal booster inoculation . We therefore suggest that the intramuscular and subcutaneous routes continue to be used for primary vaccinations and that the highly effective intradermal route be restricted to booster inoculations . This is the first long term study of this vaccine and should be a guideline for the pre-exposure treatment of high-risk personnel. Mutat Res, 1976 Feb, 34(2), 291 - 8 The cytogenetic effect of an X-ray contrast medium in Chinese hamster cell cultures; Schmid E et al.; Chinese hamster cell cultures were treated with different concentrations of Joduron, a water-soluble iodized X-ray contrast medium . The cytogenetic effect was analysed for a treatment period of 2 or 16 h . Jorudron primarily acts on the mitotic apparatus of the cell . The type of damage ranges from different forms of initial "C-mitosis" to unpolarized stathmokinesis . Additionally, structural chromosome damage, mainly of the chromatid type, was observed, especially after a Joduron treatment for 2 h. J Dairy Sci, 1976 Feb, 59(2), 216 - 23 Response to labeled precursor amino acids, varying cell density, and graded amino acid complement for protein synthesis in mammary cell culture; Park CS et al.; Effect of labeled precursor amino acids, varying cell densities, graded quantities of amino acid complement, and incubation environment on milk protein synthesis were studied with cultures of mammary cells isolated from Sprague Dawley rats . The essential amino acid complement of Eagle's minimal essential medium was used as base . Protein synthesis, measured by incorporation of labeled lysine, leucine, and phenylalanine, was affected by source of label for the "beta-lactoglobulin fraction" and beta-casein but not alpha-lactalbumin . Cell numbers between 6 X 106 and 6 X 107 per 5 ml of culture medium did not significantly alter rates of synthesis . Increasing amounts of amino acid concentration from one to three-fold increased synthesis of "beta-lactoglobulin fraction" and alpha-lactalbumin regardless of cell population . Response to addition of essential amino acid for "beta-lactoglobulin fraction" synthesis was linear over one to five-fold with 30.9 mug/flask per fold addition (linear regression coefficient; squared correlation = .91) . Results were similar for beta-casein synthesis; 25.9 mug/flask and squared correlation = .91 . No culturing effects between carbon dioxide and conventional incubators were significant. J Protozool, 1976 Feb, 23(1), 147 - 50 Strain-dependent thermosensitivity influencing intracellular differentiation of Trypanosoma cruzi in cell culture; Brener Z et al.; Temperature strongly influenced morphogenesis of intracellular trypomastigotes in cell culture infected with 2 different strains of T . cruzi . With the Gilmar strain the amastigote-to-trypomastigote differentiation readily occurred at 33 and 37 C, whereas the CL strain differentiation took place at 33C but was inhibited at 37 C . The possiblity of this selective thermosensitivity resulting from mutational adaptation of the parasite is discussed. J Clin Microbiol, 1976 Feb, 3(2), 149 - 56 Comparison of a microneutralization test in cell culture and virus neutralization test in embryonated eggs for determining infectious bronchitis virus antibodies; Wooley RE et al.; A microneutralization test (MNT) system utilizing cytopathic effect end points was effective in determing neutralization indexes for infectious bronchitis virus antibodies . The system is reproducible within 1 index unit at the 95% level of probability . Comparison of the MNT to tests in eggs resulted in a positive correlation (B =0.81), which was significant (P greater than 0.01) . The quantitative dose-response relationship of the MNT is linear (P greater than 0.005), with the 95% prediction limits fitting between one 10-fold dilution. In Vitro, 1976 Feb, 12(2), 141 - 6 The dissociation of insect embryos for cell culture; Kurtti TJ et al.; Procedures and solutions were developed for dissociating embryos of Blattella germanica in preparation for primary cell culture . Trypsin solutions were maximally effective at 0.01% for germ bands but higher concentrations, 0.05 to 0.1% were needed for embryos in later stages. Folia Biol (Praha), 1976, 22(2), 101 - 7 The blocking effect of conditioned media from tumour cell cultures on the lysis of target cells by immune lymphocytes and macrophages; Lavrovsky VA et al.; Conditioned media prepared from tumour cell cultures of three mouse strains and man blocked the lytic reaction of target cells by allogeneic immune lymphocytes and macrophages . No effect was exerted on this reaction; when conditioned media prepared from non-tumour cell cultures were utilized . The lytic reaction was even enhanced in some cases . It is suggested that tumour cells cultured in vitro release into culture media substances which may inhibit the lysis of target cells by lymphocytes and macrophages. Vopr Onkol, 1976, 22(2), 51 - 5 {Mitotic cycle in cell cultures infected with oncogenic type-12 adenoviruses}; Ageenko AI et al.; Oncogenic adenovirus of type 12 in the culture of rat embryo fibroblasts, in which it induces an abortive infection, and in HEp-2 culture, whereas it shows reproduction and causes lytic infection, in the early stationary phase causes shortening of the mitotic cycle and its separate periods . Reduction of the mitotic cycle duration occurs on account of shortening of the presynthetic stage and DNA synthesis stage . This property of the virus is in agreement with its capacity to stimulate proliferation of infected cells and is likely to be one of the necessary conditions for development of malignant transformation. Vopr Onkol, 1976, 22(1), 43 - 7 {Activity of hexokinase isoenzymes in the nuclei of cell cultures infected with oncogenic type-12 adenovirus}; Ageenko AI et al.; The isoenzymic spectrum of a glycolytic enzyme-hexokinase (HK . 2,7.1.1) in the globuline fraction of cell nuclei of rat embryo fibroblasts (REF), infected with human adenovirus of type 12, was studied at 3, 5, 8, 18, 24 days of cultivation . Control studies revealed 3 hexokinase isoenzymes, the third one showing the highest activity and electromobility . In cultures under experiment the first enzyme was found to be lost at 5, 8, 18 days of infection and its activity to be enhanced on the 24th day . The activity of enzymes II and III increased yet on the 3d day of the culture infection . These alterations were especially pronounced to the start of morphological transformation (18th day) and at the 24th day, when the culture was entirely transformed. Vopr Virusol, 1976 Jan-Feb, (1), 75 - 83 {Analysis of the long-term results of contact of human cell cultures with influenza virus}; Medvedeva MN et al.; Influenza A/Hong Kong/1/68 and A/Victoria/35/72 viruses may produce in primarily trypsinized human embryo kidney (HEK) cell culture a chronic form of persistence accompanied by periodic emergence of cytopathic changes arrested by additional medium change . This persistence causes morphological changes in HEK culture manifested in the substitution of epithelial elements by fibroblasts and prolongs the "life" of culture by over 100 days as compared to the controls . The chronic form of persistence of these viruses in human embryo lung diploid cell culture (HELDC) was accompanied by a cytoproliferogenic effect but did not lead to histomorphological changes and did not exert "oncogenic-lide" changes in cell membranes . Inapparent infection with A/Hong Kong/1/68 virus in HELDC did not cause any histomorphological and cytokaryological abnormalities and was accompanied by complete elimination of the virus from the culture . No oncornavirus contamination was found in HELDC cluture either in intact state or after inoculation with influenza virus. Endocrinology, 1976 Jan, 98(1), 25 - 32 Maintenance of separated rat pituitary mammotrophs in cell culture; Snyder J et al.; Dispersed female rat anterior pituitary cells were cultured in Medium 199 containing 20% fetal calf serum for 30 days . Prolactin levels in the culture medium remained relatively constant during this time, ranging from 30-40 ng/10,000 cells seeded/day . The total quantity of prolactin released into the medium was 10-15 times that originally contained in the cells . Morphological integrity of the mammotrophs was maintained . Using velocity sedimentation at unit gravity, cells from untreated, overiectomized or estrogen-primed animals were separted into several fractions, and subsequently cultured for 14 days . Not all mammotrophs secreted the same quantity of hormone during this time . The data suggest that the pituitary of the female rat is composed of a heterogeneous population of mammotrophs, and that their capacity to secrete prolactin in vitro may, in part, be reflected by the previous physiological status of the animal. J Gen Virol, 1976 Jan, 30(1), 123 - 30 Comparative studies of some African arboviruses in cell culture and in mice; Way JH et al.; Twenty African arboviruses, five alphaviruses, nine flaviviruses, three Bunyamwera Group viruses, two Bwamba Group viruses and one ungrouped virus were titrated in parallel in 11 cell systems in suckling mice and adult mice . The relative sensitivities of the in vitro and in vivo systems have been compared . The highest infectivities were obtained in suckling mice . Vero and LLC-MK2 cells produced plaques with the greatest number of viruses and Semliki Forest virus grew most readily . Ntaya virus and Dengue 1 virus were difficult to culture in vitro and Zika virus yielded better in cell culture than in adult or suckling mice . In vitro and in vivo neutralization tests were made on human sera in groups of 50 . Each group of sera was tested against one of five viruses, representative of three of the arbovirus groups titrated . Good agreement was obtained between the two test systems with West Nile, O'nyong-nyong and Wesselsbron viruses but there were significant differences in results obtained with Germiston and Pongola viruses. Biomater Med Devices Artif Organs, 1976, 4(3-4), 235 - 61 Quantitative cell culture biocompatibility testing of medical devices and correlation to animal tests; Wilsnack RE; The biocompatibility of a wide variety of biomaterials was quantitatively assessed, in a physiologically normal environment" as to cytotoxicity induced in WI-38 cells by cell culture medium extracts . Materials tested included PVC plastic, rubber, silicone rubber, polyethylene, polypropylene, acetal, polyurethane, Teflon, nylon, epoxy, and polystyrene . Cell culture test results were correlated to U.S.P . animal tests . Potential test artifacts, lead, barium, cadmium, and endotoxin were tested for cytotoxicity in WI-38 cells . Cell culture methods yielded more positive tests, particularly rubber, PVC plastic and silicone rubber compounds, than observed in U.S.P . animal tests . Positivity in animal tests did not correlate quantitatively to cytotoxic titers in cell culture . Discrepancies between cell cultures tests and animal tests, specifically rubber compounds, were attributable, in some instances, to differentials in elution efficiency between saline, cottonseed oil, and complete MEM cell culture medium . In other instances, particularly PVC plastics, differences between cell culture and animal test results were due to an inherent difference in the two indicator systems to respond to specific toxic moieties. Acta Biol, 1976, 27(2-3), 191 - 7 3H-GABA uptake and acetylcholinesterase activity in dissociated cell cultures of the medial hypothalamus; Makara GB et al.; Medial hypothalamic tissue of 1 to 4 days old rats was dissociated and cultured in vitro for 8--10 days . Neuronal perikarya were demonstrated by supravital methylene blue staining and electron microscopy . Synapses with typical vesicles and subsynaptic thickening were also observed . 3H-GABA was taken up into a small percentage of the cells in the cultures . Neuron-like perikarya and long processes accumulated the label while many neurons contained much less activity . Some astroglial and oligodendroglial cells and processes also accumulated GABA . A few neurons in these cultures contained acetylcholinesterase . It is concluded that neurons concentrating GABA and containing acetylcholinesterase are present in the hypothalamus of rats of 1 to 4 days of age and can be maintained in dissociated cell culture. Ann Rech Vet, 1976, 7(3), 223 - 30 Reproduction of the cycle of coccidia Eimeria acervulina (Tyzzer, 1929) in cell cultures of chicken kidneys; Naciri-Bontemps M; The cycle of Eimeria acervulina was grown in primary culture of cells of three-week-old-chicken kidneys . EHT medium (Eagle, Hydrolysate of Lactalbumine, Bacto-Tryptose phosphate) allowed the development of this coccidium . 44 hours after infestation of the cells with sporozoites, the first schizonts appeared . The merozoites of first generation were released after 54 hours . They invaded the neighbouring cells and developed in them into schizonts of second generation mature after 68 hours . After 72 and 93 hours, a third and a fourth generation of schizonts were noticed . Merozoites IV create the Gamogony . To obtain the gamogony in vitro, we inoculated the cultures with merozoites IV recovered from axenic animals . The oocysts were released into the medium 45 hours after inoculation. Tsitologiia, 1976, 18(6), 755 - 9 {Cytogenetic study of continuous pig kidney cell cultures chronically infected with the Kilham virus}; Mikhailova GR et al.; A persistent infection of the continuous embryonal pig kidney cell cultures induced by a rat parvovirus (the Kilhem virus) did not alter morphological or karyological characteristics of the cultures, and caused no transformation of these . The data obtained suggests the resistance of the pig karyotype to the virus under investigation. Prog Clin Biol Res, 1976, 9, 41 - 7 Regulation of transport in mammalian cell culture; Oxender DL et al.; The regulation of amino acid transport has been investigated in Balb/3T3 cells . Transport for neutral amino acids in animal tissues is carried out by two distinct systems . The transport activity of the A system (alanine preferring) is inhibited by high internal of substrate amino acids, a process termed trans-inhibition . In contrast, the L system transport activity is greatly stimulated by high internal levels of substrate, a phenomenon termed trans-stimulation . Regulation of amino acid transport in animal cells occurs by a repression-derepression mechanism or by a feedback inhibition or feedback stimulation process . The level of endogenous amino acids is shown to be important in the regulation of transport activity . Cells which are slow growing or quiescent have increased levels of endogenous amino acids, which in turn effect the transport activity . The A system transport activity is decreased in quiescent cells, whereas L system transport activity increases . Conditions which effect endogenous amino acid levels have an effect on transport activity . Feedback regulation of transport activity through the amino acid pool levels is another way animal cells can regulate transport activity. Ateneo Parmense Acta Biomed, 1976 Jan-Feb, 47(1), 59 - 67 {Regulation of amino acid transport in avian fibroblasts from growing and quiescent cell cultures (author's transl)}; Tramacere M et al.; The regulation of amino acid transport across the cell membrane by adaptive mechanisms has been studied in chick embryo fibroblasts obtained from growing and quiescent cell cultures . Changes in transport activity as a function of time under various in vitro conditions (amino acid dependence, active and inhibited protein synthesis) have been evaluated by measurements of initial entry rates with representative amino acids. Nouv Rev Fr Hematol Blood Cells, 1976, 17(1-2), 161 - 6 An approach to human preleukemia using cell culture studies; Senn JS et al.; Cell culture methods applied to the study of acute leukemia have indicated the presence of many abnormalities . Utilizing this knowledge, we have applied cell culture techniques to the evaluation of a patient population with a recognized risk of developing leukemia . We demonstrate that cultural abnormalities present in some patients with sideroblastic anemia are similar to those seen in acute leukemia, and that these perturbations may be shown before leukemia develops . This study suggests that cell culture abnormalities may reflect mechanisms operative in vivo, and preceding the development of overt leukemia. Acta Microbiol Pol A, 1976, 8(1), 79 - 86 Growth of rubella virus in primary rabbit kidney cell cultures maintained with and without calf serum; Filczak K et al.; Rubella virus growth was tested in primary rabbit kidney cell cultures, maintained with or without calf serum . In fluid phase of the cultures maintained with 1.5% of heat-inactivated calf serum, the infectious virus titers were much higher than in the system without serum . The differences reached 1.5-2.0 log10 TCID50/ml . Virus multiplication curves also ran different courses . In serum-containing system virus titer increased up to the 9th day post infection, while without serum--only up to 4-5 days . The time of appearance and the type of cytopathic effect were not affected by the absence of serum or by its presence in a concentration of 1.5%. Eur Surg Res, 1976, 8(1), 71 - 80 Effect of pulverized implantation materials (plastic and glass ceramic) on growth and metabolism of mammalian cell cultures; Schachtschabel DO et al.; The effect of pulverized plastic and glass-ceramic materials (methylmetacrylate, MNA), which are used as implantation materials in surgical medicine, on cell growth, DNA synthesis rate (adjudged by incorporation of 3H-thymidine into DNA), glucose consumption and lactate production (glycolytic rate) was studied in asynchronous monolayer cultures of rather fast proliferating Ehrlich ascites tumor cells and rather slowly proliferating diploid human fibroblasts . Exposure of Ehrlich ascites cells to high concentrations (2 mg/ml; 10 ml medium per culture) of ceramic or plastic material resulted in a gradual inhibition of cell growth and DNA synthesis rate . Protein synthesis, as measured by the incorporation of 3H-leucine, was somewhat less affected than DNA synthesis . Also, the glycolytic rate of Ehrlich ascites cells was slightly but significantly decreased in the presence of 2 mg/ml ceramics or MMA . Exposure of Ehrlich ascites cells to 0.2 or 0.02 mg/ml over a period of 46 h revealed none or only slight inhibitory effects on growth, DNA synthesis or glycolytic rate . On the other side, growth, DNA synthesis and glycolytic rates of human fibroblasts were nearly not affected by the presence of the same concentrations (up to 2 mg/ml, incubation period: 92 h) of pulverized ceramic or plastic material (MMA) . It is suggested that this differential cellular sensitivity might be related to differences in the binding (to the cell surface) or uptake of these substances and possibly to differential intracellular lysosomal activation. In Vitro, 1976 Jan, 12(1), 44 - 7 The synthesis of cartilage collagen by rabbit and human chondrocytes in primary cell culture; Schindler FH et al.; This report describes a method for preparing primary cell cultures of differentiated rabbit sternal and human vertebral cartilage cells . These cell cultures were shown to synthesize primarily alpha1 chains, which is taken to mean that at least 82% of the collagen produced is cartilage specific collagen (type II). Tissue Cell, 1976, 8(2), 277 - 92 Cellular composition of erythropoietic cell populations and aggregate cell cultures derived from early chick blastodiscs; Dardick I et al.; Light and electron microscopy of suspensions of cells prepared by dispersing chick blastodiscs at primitive-streak and head-fold stages showed the presence of numerous yolk granules, yolk-rich endodermal cells and occasional presumed ecto- and mesodermal cells . Several cell fractions prepared from this suspension by sedimentation through discontinuous Ficoll gradients were of similar composition . No enrichment of any particular cell type which might account for either differential sedimentation or erythropoietic potential of the fractions could be recognized . Two fractions, EP 1, and EP 2, were cultured as cell aggregates on vitelline membranes . EP 1 produced highly organized blood islands containing developing erythrocyte cells, organized endothelium, fibroblasts, thrombocytes and occasional granulocytes . Blood islands derived from EP 2, on the other hand, contained essentially only aggregates of erythroblasts embedded in endoderm . It is tentatively suggested that EP1 contains young multipotential hematopoietic precursors while EP 2 has only older blood-cell precursors committed to erythrocyte development . No cellular basis for the resolution of EP 1 into two complementary subfractions could be recognized. Vopr Onkol, 1976, 22(2), 44 - 51 {Herpes virus in cell cultures of the hematopoietic organs of Hamadrymas baboons with hemoblastosis}; Agrba VZ et al.; Five transplantable suspension lymphblastoid cell cultures from haematopoietic organs of baboons with malignant lymphoma were obtained, designated as KMPG-1, SPG-1, 2, 3, 4 . The cells of these suspension cultures contain HVP virus belonging to herpes-type according to morphological (electron-microscopic) investigation, but differing from infectious viruses of this group and closely related to Epstein-Barr virus as evidenced by its characteristics . In conformity with the preliminary data the isolated HVP virus is oncogenic for M . arctoides monkeys. Arch Virol, 1976, 51(3), 217 - 25 Measles virus: study of induced transfer of biological properties . II . Fluorescence studies on rescue of neurotropic strain in cell culture; Weil ML et al.; HeLa cells are non-permissive for the neurotropic suckling mouse strain of measles virus (MMV), but are permissive for cell-adapted Edmonston strain of measles virus (EDm) . Fluorescence and electron microscopy demonstrated no membrane fluorescence and no membrane associated viral components, as well as characteristic lack of nuclear antigen after MMV infection of HeLa cells . This appearance differs markedly from the membrane, cytoplasmic and nuclear fluorescence after Edm infection of HeLa cells . Fluorescence microscopy demonstrates fusion of the two dissimilar syncytia after mixed infection . This suggests Edm envelopment of MMV nucleocapsids may be the means of MMV rescue in this system. J Clin Microbiol, 1976 Jan, 3(1), 72 - 4 Retention of motility of Treponema pallidum (Nichols virulent strain) in an anaerobic cell culture system and in a cell-free system; Sandok PL et al.; Optimum parameters for retention of motility of Treponema pallidum (Nichols virulent strain) were found by anaerobic co-incubation of the treponeme with rat glial cells and anaerobic incubation in spent medium obtained from glial cells originally grown aerobically. Dev Biol Stand, 1976, 35, 55 - 60 Certain aspects of foot--and--mouth disease . Virus production in growing BHK suspended cell cultures; Barteling SJ; Production of FMDV in growing BHK suspended cell cultures offers several technical advantages: no medium change and no sedimentation of cells prior to infection are needed, thus saving time and medium . However, the final product should be as free of serum proteins as possible . For this purpose polyethylene-glycol-(PEG)-treated serum can be used for the stimulation of cell growth in combination with precipitation of the virus with PEG . With this method virus preparations are obtained in which practically no serum proteins can be estimated . Recently the use of serum-free medium has been reported for a BHK line which had been adapted to this medium . This also offers possibilities of virus cultivation in growing cells . Two of our BHK lines also grow in a cheap serum-free medium in which amino acids are replaced by a combination of lactalbumin hydrolysate and peptic peptone . With BHK cells adapted to this medium high cell yields are obtained . The use of PEG-treated serum will be compared with the use of the low cost serum-free medium with respect to FMDV production. Vet Med Nauki, 1976, 13(10), 60 - 6 {Study of foot-and-mouth disease virus inhibitors in cell cultures and experimental animals}; Tekerlekov P et al.; Studied was the inhibiting action of some synthetic agents conditionally denoted No . 3 (benzamidazol), No . 76, and No . 78 (imidazolins) on the reproduction of the foot-and-mouth disease virus in cell cultures, newborn mice and guinea pigs . It was irrefutably demonstrated that all three agents produce an inhibiting effect on the virus . This effect was enhanced by the combined use of these inhibitors . It was found that best effect on the virus' replication produced the combination of agent No . 3 and some of the other two inhibitors . Discussed is the mechanism of action of these compounds. Bull Pan Am Health Organ, 1976, 10(3), 205 - 11 A perfusion culture system for virus vaccine manufacture in diploid cell cultures; Mann GF et al.; Development of a new perfusion culture system for the production of attenuated poliomyelitis virus in cultures of diploid cells is described . The growth characteristics of the diploid cells (MRC-5) were found to be normal in the perfused system . Procedures for the routine production of cell cultures at twice the cell density of stationary bottle cultures were established . The yield of virus (Lsc 2ab) per cell and per unit of surface growth area were observed to be significantly higher in the perfused system than in parallel stationary bottle culture controls--by factors of three- and five-fold, respectively . The field was confirmed to be within the experimental range when small production-scale vessels were used . Subject to satisfactory results in the testing of the virus product, this system could be highly economic in large-scale vaccine manufacture. Arch Immunol Ther Exp (Warsz), 1976, 24(5), 769 - 75 Production of interferon in human diploid cell cultures; Zielinska-Jenczylik J et al.; Eleven human diploid cell lines were compared for their ability to produce interferon in response to Newcastle Disease Virus . Sensitivity of the cultures of MM, Sindbis VSV and VR viruses was also studied . Human cells derived from various tissue of a single embryo responded variably to interferon inducer . Using selected viruses interferon production was studied in two systems, in cultures of leukocytes and in human embryonic cells. Arch Exp Veterinarmed, 1976, 30(3), 427 - 32 {Cytological and histochemical studies on cell cultures infected with bovine herpesvirus type 2}; Vesselinova A et al.; Cell cultures of embryonic calf kidney which had been infected with bovid herpes virus 2 were examined for cytological and histochemical changes . The morphological changes recorded from cells damaged by virus infection included the formation of gigant syncytial cells and intranuclear inclusions of Cowdry Type A . The cytological changes in the infected cells were accompanied by variation in enzyme activity . Recordable were rise in lactate dehydrogenase and alkaline phosphatase as well as decline in succinate dehydrogenase and acid phosphate activity . These phenomena were found to have resulted from impediment of cell metabolism by virus action. Chemotherapy, 1976, 22(6), 362 - 71 Use of cell cultures with persistent virus infections to test the efficacy of antiviral compounds; Schwobel W et al.; BHK-21 cells persistently infected with either vaccinia or foot and mouth disease virus were used to study the efficacy of antiviral compounds . The results of the persistent infection cell culture (PICC) test were compared with those obtained by the plaque reduction (PR) test . The comparison showed that: (1) the PICC test is more informative than the PR test; (2) stimulative as well as inhibitory activities of compounds are detectable, and (3) since the PICC test can be carried on for several weeks or even months this test is especially well suited to study the problem of drug resistance in cell cultures. Vopr Virusol, 1976 Jan-Feb, (1), 50 - 6 {Identification of a hemadsorbing agent discovered in uninfected mouse L cell cultures and also the same cultures chronically infected with Sindbis virus}; Iakhno MA et al.; Electron microscope examinations of continuous lines of mouse L cells, both uninfected (L-init) and chronically infected with Sindbis virus (L-SV) revealed accumulations of ribonucleoprotein strands and virions corresponding by their parameters to paramyxoviruses in the cytoplasms of the cells . Further studies showed L-init and L-SV cell lines to have a manifest hemadsorption effect which could be completely inhibited by antiserum to parainfluenza SV5 virus . Immunofluorescence procedures detected intensive fluorescence in the cytoplasm of these cells which was observed only after treatment of the cells with antiserum to SV5 virus . In response to inoculation of cell homogenates of continuous L-init and L-SV cultures guinea pigs developed antihemagglutinating antibody to simian parainfluenza SV5 virus . On the basis of these results it may be assumed that virus-specific structures and viruses identical by their parameters to paramyxoviruses observed in electron microscope examinations of continuous mouse L-init and L-SV cells are simian parainfluenza SV5 virus. J Natl Cancer Inst, 1976 Jan, 56(1), 119 - 24 Characterization of mouse mammary tumor viruses from primary tumor cell cultures . II . Biochemical and biophysical studies; Kimball PC et al.; Primary mammary tumor cultures of RIII, GR, DD, BALB/c, and BALB/cfC3H mice were examined for mouse mammary tumor virus (MuMTV) production . Levels of production of 12-32 mug virus protein/day/75-cm2 culture flask could be maintained for 30-50 days with daily virus harvests . The viruses from tumor cell cultures of these mouse strains contained DNA polymerase with a strong preference for Mg++ over Mn++ as the divalent cation, a characteristic of DNA polymerase of MuMTV from mouse milk . These viruses from tumor cell cultures were excellent sources of MuMTV 3H-complementary DNA (complexed to 60-70S RNA) and radioactive 60-70S RNA, sufficiently free of contaminating murine leukemia virus nucleic acids, that can be used in molecular hybridization experiments . The effects of several culture parameters on MuMTV production were also studied. J Natl Cancer Inst, 1976 Jan, 56(1), 111 - 7 Characterization of mouse mammary tumor viruses from primary tumor cell cultures.I . Immunologic and structural studies; Kimball PC et al.; Primary cell cultures of mammary tumors from Rill, GR, DD, BALB/cfC3H, and BALB/c mice were prepared by trypsin-EDTA dissociation of tumors . Cultures from these strains contained predominantly cells of epithelial morphology which formed three-dimensional domelike structures . Cultures from Rill, GR, DD, and BALB/cfC3H tumors produced extra-cellular type-B mouse mammary tumor virus(es) (MuMTV), either in the absence of detectable type-C virus or with less than 1% contamination with type-C virus . This was determined by radioimmunoassays for MuMTV and murine leukemia virus (MuLV) antigens . Only BALB/c cultures produced MuMTV with as much as 3% contaminating MuLV . High levels of MuMTV surface antigen were also found in soluble form in culture supernatants . Virus polypeptide analyses by electrophoresis on polyacrylamide gels showed that the Rill BALB/cfC3H, DD, and BALB/c viruses all contained polypeptides characteristic of MuMTV . Primary cultures of mammary tumor cells make available a source of purified MuMTV antigens, structural proteins, and nucleic acids for comparative studies of MuMTV from various mouse strains. Johns Hopkins Med J, 1976 Jan, 138(1), 1 - 5 Monolayer cell culture of human pancreatic beta cell tumor: effect of glucose and somatostatin on insulin release; Fujimoto WY et al.; A human pancreatic beta cell tumor was maintained in monolayer cell culture for 80 days . The culture was terminated because of bacterial infection . Probably because extensive trypsin-collagenase dissociation was unnecessary, the dissociated cells attached much more quickly to the surface of the culture flask than do rat pancreatic cells obtained by enzymatic dissociation . Insulin release not only oscillated widely during the first 40 days of culture but also showed a decline from 380 mU the first week to about 50 mU/week the seventh week . For some unknown reason fibroblast overgrowth was not a major problem . Reduction of the medium glucose concentration from 16.5 mM to 5.5 mM did not alter insulin release rate . At glucose concentration of 16.5 mM, somatostatin 1.0 mug/ml reduced insulin release by 40% . From our previously reported studies on the effect of somatostatin on insulin release by monolayer cell cultures of rat endocrine pancreas, we conclude that the constant release of insulin by the tumor cells is relatively nonstimulated . We have confirmed that monolayer cultures of human pancreatic beta cell tumor do not represent a good model for normal human beta cell function because of the major shortcoming of an apparent inability to recognize glucose as a secretogogue. C R Seances Soc Biol Fil, 1976, 170(2), 345 - 9 {Influence of a lathyric agent and of hypercholesterolemic serum on cell cultures of fetal rabbit aorta}; Desgranges C et al.; Cell cultures of foetal rabbit aorta are cultivated with a lathyric agent (beta-amino-propio-nitrile) or with an hypercholesterolemic serum; if morphological features, in these two cases, correspond with modifications observed, in vivo, when adult rabbits are respectively submitted to the same treatment, enzymatic activities of collagen metabolism vary in opposite way . Therefore, the influence of different parameters to be studied on vascular cell functions become easier. Gerontology, 1976, 22(6), 461 - 72 Age dependence of the biosynthesis of intercellular matrix macromolecules of rabbit aorta in organ culture and cell culture; Moczar M et al.; The age dependence of the relative rate of biosynthesis of intercellular matrix macromolecules was studied in organ culture and cell culture obtained from aortas of newborn, young and adult rabbits . In organ culture there was a strong decrease with age of the rate of incorporation of (14C)-lysine and (3H)-glucosamine in all macromolecular fractions . Neosynthesis of elastin could be demonstrated by the isolation of labelled demosine at all ages . In cell cultures derived from newborn and adult aortas, no decrease in total incorporation was noticed . The pattern of synthesis and secretion of glycosaminoglycans and glycoproteins did however change with age . These results suggest the existence of matrix-dependent and of a matrix-independent regulation of the relative rate of synthesis of matrix macromolecules. Dev Biol Stand, 1976, 35, 91 - 6 {Several criteria of evaluation of foot-and-mouth disease virus reproduced in cell cultures in suspension}; Girard HC; The study of the plaques produced by viruses Asia and O1 reveals different properties which may depend on the virus or on the cell or its method of culture . Antigenic differences and subsequent immunological differences correspond to differences in plaques . On the other hand, the cell line in suspension evolves both in its morphology and its receptivity during the passages . All these variations imply the observations of quantitative and qualitative criteria of evaluation in order to prepare vaccines from viruses similar to viruses specific to a given epizooty. Vet Med Nauki, 1976, 13(8), 18 - 22 {Demonstration of the Bovid herpesvirus 2 in cell cultures with the aid of fluorescent antibodies}; Dilovski M et al.; Used was the immunofluorescence method employing fluorescinisothiocyanate-labeled antibodies against Bovid herpesvirus 2 . The localisation and the dynamics of the virus antigen were followed up in cell cultures of calf kidney epithelium . Results showed that there was a specific cytoplastic-nuclear fluorescence in the infected cells . The dynamics of the virus multiplication revealed the presence of a specific antigen by about the 6th hour following the infection of the cells . Discussed is the problem of using the immunofluorescence technique in the differentiation of herpes mammillitis from the rest vesicular diseases of the cow's udder that are similar to one another by clinical picture. Scand J Dent Res, 1976 Jan, 84(1), 37 - 45 pH and the cytotoxicity of fluoride in an animal cell culture system; Helgeland K et al.; To investigate the mechanism for the toxicity of silicate cement as observed in a cell culture system, the effects of pH and fluoride were tested on human epithelial cells (NCTC 2544) . At pH 7.3, fluoride concentrations from 15 to 25 mug/ml (0.79 to 1.3 mM) had a growth inhibitory effect . When pH of the incubation medium was lowered in the range 7.0 to 6.4, an enhanced cytoxic effect of fluoride was found, and even at 5 to 10 mug/ml growth inhibition occurred . Concomitant with the enhanced cytotoxicity of fluoride at low pH, there was an increased utilization of glucose and formation of lactate . Upon lowering the pH of the incubation medium from 7.4 to 6.7 a twofold increase in the intracellular concentration of fluoride was found. Humangenetik, 1975 Dec 23, 30(4), 325 - 30 A technique for in situ karyotyping of primary amniotic fluid cell cultures; Schmid W; A time proven technique is described for growing amniotic fluid cell cultures on cover glasses in Leighton tubes and for processing the mitotic cells in situ . Karyotyping the clones in situ eliminates most of the problems caused by somatic chromosome mutations in vitro and by maternal cell growth. Experientia, 1975 Dec 15, 31(12), 1473 - 4 A cell culture substrate obtained from heat-fused collagen; Stephenson EM; Coverslips coated with rat-tail collagen dried at 37 degrees C were placed in a hot-air sterilizing oven at 160 degrees C for 2 h . The resulting transparent sterile film was found to be a useful multipurpose substrate for cell culture and for subsequent histological sectioning. Biull Eksp Biol Med, 1975 Dec, 80(12), 81 - 4 {Temperature limits of mitosis in mammalian cell cultures}; Sushkov FV et al.; Mammalian cells of different origin (11 strains) were cultivated at the temperature of 25--41 degrees to measure the temperature limits of mitosis . Different strains of the cells reacted to the increase or decrease in the cultivation temperature in a dissimilar way . The difference between the upper temperature limit and the optimum one was not over 5 degrees . Cell division did not end with the temperature fall by over 10 degrees . Various cell strains responded to the temperature decrease in a different way . Most cellular population had three cell types . The majority of the cells were capable of dividing at the threshold temperature; some cells could enter mitosis without completing it and stop at the metaphase . The temperature limits of mitosis were not related to the species and tissue origin of the cells. Can J Physiol Pharmacol, 1975 Dec, 53(6), 1037 - 41 Effects of cortisol on serially propogated fibroblast cell cultures derived from the rabbit retal lung and skin; Smith BT et al.; Cortisol affects the growth of serially propogated, fibroblast cell cultures derived from the rabbit fetal lung in a manner which is dependent upon the gestational age of the material used: early in gestation (20 days), the hormone (10(-7)-10(-5) M) stimulates {6-3H}thymidine incorporation into DNA, while in late gestation (28 days), cortisol (10(-7) and 10(-6) M) inhibits this process . Cultures derived from the rabbit fetal skin are inhibited by cortisol (10(-5) M) at both gestational ages . Fibroblasts derived from lung, but not from skin, efficiently convert cortisone to cortisol and this activity increases with advancing gestation . Cortisol does not affect the incorporation of {3H}choline into lecithin by confluent cultures of any of the fibroblast types studied. Cancer, 1975 Dec, 36(6 Suppl), 2327 - 33 The gardner syndrome . A study in cell culture; Danes BS; Tetraploidy was increased in skin fibroblast cultures derived from three probands with the Gardner syndrome and nine affected members of one family as compared to that occurring in cultures from five unaffected family members as well as from six relatives by marriage and 15 normals grown in the laboratory at the same time under the same conditions . Tetraploidy was present at the first subculture (2 weeks after the initial biopsy was cultured) and for each line studied the percentage of dividing cells showing tetraploidy remained constant . Increased occurrence of tetraploidy was not observed in skin fibroblast cultures from patients with the genetic disorders familial polyposis coli, familial osteomas, and familial fibromatosis (neurofibromatosis), each of which show one of the four abnormal tissue growths observed in the Gardner syndrome . The relationship of the observed tetraploidy to the increased risk of such patients to develop abnormal growths and cancer has not been established . The increased tetraploidy should be of value in identifying the presence of the gene for the Gardner syndrome in high risk families. Cancer Res, 1975 Dec, 35(12), 3623 - 7 Replication of an avian myxovirus in tumor cell cultures obtained from effusions of mammary carcinoma patients; Illiger HJ et al.; In view of the possible use of viruses for the immunotherapy of breast cancer, the replication of a strain of fowl plaque virus was studied in the tumor cells of 11 mammary carcinoma patients with malignant effusions . The tumor cells were obtained by centrifugation on iodamide solutions, then cultured in vitro, and infected by a fowl plaque virus previously adapted to grow in a mammary carcinoma cell line . Virus multiplication was observed in all cases, a prerequisite for the use of autologous viral oncolysates for immunotherapy in mammary carcinoma patients. Proc Soc Exp Biol Med, 1975 Dec, 150(3), 636 - 40 Origin of antibody-dependent, lymphoid-cell-independent hemolytic plaques in rabbit spleen cell cultures; Lambert WC et al.; This report describes a phenomenon that may be a significant source of error in the data acquired from hemolytic plaque assays of lymphocyte cultures . The data show that background antibody in the normal-serum supplement of the culture medium does not actually support initiation of a vigorous primary-type plaque-forming cell (PFC) response to sheep erythrocytes (SE) . Instead, the background antibody causes the development of numerous spurious lymphoid-cell-independent plaques (LCIP) . In general agreement with the literature, primary-type rabbit spleen cell responses in vitro were low in culture media supplemented with fetal bovine serum, a serum which does not contain background antibodies to SE. Clin Exp Immunol, 1975 Dec, 22(3), 486 - 92 In vitro stimulation of murine lymphoid cell cultures by levamisole; Merluzzi VJ et al.; Levamisole has been reported to act as an immunological adjuvant . Experiments reported here on the effect of this agent on a variety of murine lymphoid culture systems were designed to gain an insight into its mechanism of action . We have found levamisole to be a weak mitogen for mouse spleen cells producing a dose related response which peaks at 48 hr in culture . The drug acted to augment the response of spleen cells to sub-optimal concentrations of concanavalin A, but had no unusual effect on the lipopolysaccharide stimulation of B-cell DNA synthesis in vitro . Levamisole was directly stimulatory on enriched T-cell populations and was found to have two actions: (1) to stimulate a subpopulation of T cells and (2) to augment the response of suboptimal mitogen concentrations of concanavalin A . In addition, we have found that murine thymocytes stimulated by concanavalin A were greatly potentiated in the presence of levamisole, but this population of cells could not be stimulated directly by the drug. Infect Immun, 1975 Dec, 12(6), 1457 - 63 Evaluation ofprimary blood monocyte and bone marrow cell culture for the isolation of Rickettsia rickettsii; Buhles WC et al.; Rickettsia rickettsii was isolated from experimentally infected guinea pigs by culture of blood monocytes and bone marrow cells, and from experimentally infected rhesus monkeys by blood monocyte culture . Rickettsiae were identified in monocyte-macrophage monolayers stained by Gimenez or flourescent antibody techniques . A total of 78 culture attempts were made from 20 guinea pigs and 16 monkeys . The success of isolation of R . rickettsii in culture was positively correlated with the numbers of rickettsiae present in the blood and bone marrow . in cultures derived from infected guinea pigs, rickettsiae were usually observed after 5 to 7 days of culture, and in monkeys monocyte cultures they were usually observed within 3 to 5 days . Positive cultures were derived from guinea pigs and monkeys as early as the first day of fever and 1 to 3 days before the appearance of other clinical signs . Monocyte cultures became negative with the resolution of rickettsemia and concomitantly with the appearance of serum antibody . Monocyte culture isolation of R . rickettsii may be as sensitive for the detection of rickettsiae in blood and marrow as the intraperitoneal inoculation of guinea pigs or the plaque assay technique . Because of the simplicity of the method and because rickettsiae were often identified within 3 to 5 days after initiation, the monocyte culture technique may be useful in the early diagnois of human rickettsial disease. Cancer Res, 1975 Dec, 35(12), 3636 - 41 Functional properties of mitochondria isolated from murine L5178 lymphoblasts grown in cell culture; Carpentieri U et al.; Mitochondria were isolated from lymphoblasts grown for 5 days in cell culture . Measurement of mitochondrial respiratory activity revealed poor response to adenosine 5'-diphosphate with reduced nicotinamide adenine dinucleotide-linked substrates but well-coupled active respiration with succinate as substrate . These mitochondria also exhibited rapid initial rates of respiration-supported calcium uptake as measured by dual-beam spectrophotometry . H+/2e- and Ca2+/2e- ratios were in normal limits for the lymphoblast mitochondria during calcium uptake in the presence of phosphate . In the absence of phosphate no calcium uptake, H+ ejection, or stimulation of oxygen consumption was observed . However, the lack of discharge of the accumulated calcium from the lymphoblast mitochondria upon inhibition of respiration suggests possible different mechanisms of cation transport compared to mitochondria from normal, mammalian cell types . Electron microscopy of freshly prepared mitochondrial suspensions revealed preparations with intact outer membranes and abundant cristae and that were relatively free of other cellular structures . These studies demonstrate the feasibility of obtaining intact respiring mitochondria from cultured lymphoid cells and indicate that active ion transport in these mitochondria may be significantly different from "normal" cell mitochondria. C R Acad Sci Hebd Seances Acad Sci D, 1975 Nov 10, 281(19), 1435 - 8 {Infectious pancreatic necrosis virus: acquired susceptibility to trout serum neutralizing factor after repeated passage in cell culture}; Dorson M et al.; It has been shown previously that in normal sera from IPN free Rainbow Trout a "6 S molecule" neutralized Sp type IPN Viruses routinely used in European fish diseases laboratories . These viruses were unable to reproduce the disease under experimental conditions . After a survey of trout farms, a Sp type pathogenic virus was isolated (isolate 31/75) . After one passage on RTG2 cells this virus was fed to 7 weeks old fry and led to a 70% mortality . In contrast, a routinely passed and cloned virus (27/70) gave no noticeable mortality . This freshly isolated virus produced only small plaques on RTG2 cells (27/70 produced small and large plaques) and was not neutralized at all by the "natural" 6 S neutralizing molecule from serum . After repeated RTG2 cell culture passages of 31/75 virus, large plaques appeared at the 7th passage, and a large plaque was cloned . The virus thus cloned (8th passage) was fully neutralized by 1/200 normal trout serum . This acquired susceptibility can account for the loss of pathogenicity of cell cultured IPN viruses, and could be a "marker" of non pathogenic IPN viruses which have been recorded in trout farms. J Neurobiol, 1975 Nov, 6(6), 597 - 608 Uptake of GABA by neuronal and nonneuronal cells in dispersed cell cultures of postnatal rat cerebellum; Lasher RS; A study was made of the time course and kinetics of {3H}GABA uptake by dispersed cell cultures of postnatal rat cerebellum with and without neuronal cells . The properties of GABA neurons were calculated from the biochemical difference between the two types of cultures . It was found that for any given concentration of {3H}GABA, or any time up to 20 min, GABA neurons in cultures 21 days in vitro had an average velocity of uptake several orders of magnitude greater than that of nonneuronal cells . In addition, the apparent Kmvalues for GABA neurons for high and low affinity uptake were 0.33 X 10(-6) M and 41.8 X 10(-4) M, respectively . For nonneuronal cells, the apparent Km for high affinity uptake was 0.29 X 10(-6) M . The apparent Vmax values for GABA neurons for high and low affinity uptake were 28.7 X 10(-6) mol/g DNA/min and 151.5 mmol/g DNA/min, respectively . For nonneuronal cells, the apparent Vmax for high affinity uptake was 0.06 X 10(-6) mol/g DNA/min . No low affinity uptake system for nonneuronal cells could be detected after correcting the data for binding and diffusion . By substituting the apparent kinetic constants in the Michaelis-Menten equation, it was determined that for GABA concentrations of 5 X 10(-9) M to 1 mM or higher over 99% of the GABA should be accumulated by GABA neurons, given equal access of all cells to the label . In addition, high affinity uptake of {3H}GABA by GABA neurons was completely blocked by treatment with 0.2 mM ouabain, whereas that by noneuronal cells was only slightly decreased . Most (75-85%) of the {3H}GABA (4.4 X 10(-6) M) uptake by both GABA neurons and nonneuronal cells was sodium and temperature dependent. Vopr Virusol, 1975 Nov-Dec, (6), 693 - 8 {Study of measles virus (strain L-16) in J-96 cell culture by electron microscopy and immunofluorescence}; Dorofeeva LV et al.; The vaccine L-16 strain of measles virus was studied in a continuous line of J-96 cells (clone L-41) by the electron microscope and fluorescent antibody techniques . Cytological studies revealed a direct correlation between the intensity of symplast formation and the infective virus dose . The fluorescent antibody technique established cytoplasmic localization of the specific virus antigen . The results of electron microscope examinations of ultrathin sections of J-97 culture revealed in the cell cytoplasm and intercellular space some structures morphologically similar to virus-like particles previously described. J Toxicol Environ Health, 1975 Nov, 1(2), 323 - 7 Transformation of cell cultures as a parameter for detecting the potential carcinogenicity of antischistosomal drugs; Hetrick FM et al.; Several antischistosomal drugs and their metabolites were found to transform rat embryo cell cultures persistently infected with the Rauscher leukemia virus . The transformed cells produced fibrosarcomas when implanted into newborn rats . Cell cultures treated with either virus or chemical alone were not transformed nor were they invasive in rats . The advantages of early screening of developmental drugs in cell culture systems are discussed. J Natl Cancer Inst, 1975 Nov, 55(5), 1243 - 6 Attenuation of herpesvirus saimiri for marmosets after successive passage in cell culture at 39 degrees C; Schaffer PA et al.; A variant of Herpesvirus saimiri (HVS) stably attenuated for marmosets was isolated after serial passage of wild-type HVS in cell culture at 39 degrees C . Marmosets previously inoculated with attenuated virus experienced a significant delay in the development of lymphoma when challenged with wild-type HVS. J Clin Microbiol, 1975 Nov, 2(5), 419 - 24 Responses of isolator-derived Japanese quail and quail cell cultures to selected animal viruses; Farrow WM et al.; Thirteen oncogenic and necrotizing animal viruses were assayed in LIFE Sciences, Inc . (LSI)-specific pathogen-free Japanese quail and LSI-specific pathogen-free chicken embryo cell cultures . Nine viruses produced similar titers in the quail and chicken cell systems, whereas four viruses showed significantly higher titers in chickens . Young Japanese quail and chickens were inoculated with five selected avain viruses and maintained in stainless-steel isolators . Comparable responses were noted in quail and chickens injected with Newcastle disease virus and avain leukosis virus, but quail were significantly more resistant than chickens to fowl pox virus, laryngotracheitis virus, and Marek's disease herpesvirus . Although no overt symptoms of disease were observed in Japanese quail inoculated with most avain viruses, neutralizing antibody or virus was detected, indicating presence of an inapparent infection . In one experiment, neutralizing antibody was detected in a comparable number of quail and chickens after inoculation with avian leukosis virus . Avian leukosis virus viremia was observed at 12 and 70 days postinoculation, with the COFAL (complement fixation for avian leukosis) titers similar for quail and chickens . Most quail infected with Marek's disease herpesvirus produced neutralizing antibody within 70 days but showed no classical symptoms of Marek's disease even when held for 5 months . In contrast, all chickens inoculated with Marek's disease herpesvirus died within 20 days . The utility of quail embryo cell cultured in the preparation of vaccines and biological reagents is discussed. In Vitro, 1975 Nov-Dec, 11(6), 400 - 3 Detection of bovine viruses in fetal bovine serum used in cell culture; Kniazeff AJ et al.; This investigation employed a viral screening method detect endogenous bovine virus contaminants in commercially supplied fetal bovine serum . Fifty-one lots of fetal bovine serum from 14 suppliers were examined . Over 30% of the lots tested were found to contain bovine viruses; they included bovine virus diarrhea virus, parainfluenza type3-like virus, bovine herpesvirus-1, bovine enterovirus type 4, and an unidentified cytopathogenic agent . Of the 51 lots, 20 had been pretested by the suppliers and were considered to be free of known viral contaminants . Our viral screening methods revealed that five of these pretested lots, or 25%, contained endogenous bovine viruses. In Vitro, 1975 Nov-Dec, 11(6), 369 - 78 Insect cell culture: improved media and methods for initiating attached cell lines from the Lepidoptera; Goodwin RH; Several cell lines from the pupae of the noctuid moth species Spodoptera frugiperda, Heliothis zea, and Trichoplusia ni were isolated on a synthetic medium containing insect hemolymph and turkey serum . These lines were progressively adapted to improved media free of insect hemolymph but containing one or more of the following sera: turkey, chicken, and fetal calf . Primary culture tissue disruption was improved by substituting collagenase for trypsin . Primary culture survival was improved by controlling the total tissue volume per unit medium volum, and by the addition of glutathione to prevent melanization and to improve cell adherence to the substrate . Culture servival was also improved by heat treatment of sera, control of medium osmolality, and changes in the basal medium and serum supplementation . Some of these changes also resulted in improved growth giving higher maximal cell counts . Comparative cell growth on the various media was graphed and generation times given. Acta Virol, 1975 Nov, 19(6), 481 - 5 Enhancement of the antigenic activity and virulence of the vaccine strain E of Rickettsia prow azeki by passages in cell culture; Ignatovich VF; Changes in the biological properties of the vaccine strain E of Rickettsia prowazeki occurred upon cultivation of A1 (human amnion) cells infected with this strain . In the course of passages of these cells the antigenic activity and virulence of the rickettsia increased . The changes were observed in 10 out of 22 cell cultures examined: in 6 cultures there was an increase in the antigenic activity and in 4 both in the antigenic activity and in virulence . The time of the occ