J Natl Cancer Inst, 1979 Aug, 63(2), 455 - 64 Transmission electron microscopy of fetal rat brain cells during neoplastic transformation in cell culture; Haugen A et al.; Fetal rat brain cells were investigated by transmission electron microscopy during neoplastic transformation in long-term cell culture . Before transfer of the cells to culture, BD IX rat fetuses were treated with a single transplacental pulse of N-ethyl-N-nitrosourea (75 micrograms/g body wt) on the 18th day of gestation . During the early stages (3--4 mo), both glia-like and neuron-like cells were present in the culture, and after 2 months they formed complex aggregates ("nodules") . In contrast, corresponding secondary control cultures consisted of flat, epithelioid neural cells without neuron or astrocyte differentiation . After 3 months, cells with neuron morphology gradually disappeared . Some of the remaining cells contained many autophagosomes . After 5 months, rapid proliferation of rather homogeneous, glia-like populations was accompanied by reduction of microfilament bundles and microtubules, as well as atypical nuclei . Ability to form tumors upon sc implantation into syngeneic hosts was not observed until about 3 months later. J Natl Cancer Inst, 1979 Aug, 63(2), 337 - 9 Induction of retrovirus particles in human testicular tumor (Tera-1) cell cultures: an electron microscopic study; Bronson DL et al.; The Tera-1 and Tera-2 cell lines, established from germ-cell tumors of the human testis, were examined by electron microscopy for particles with the morphology of retroviruses . Extracellular and budding particles were observed at low frequencies only in cultures of Tera-1 cells that had been treated with 5-iodo-2'-deoxyuridine and dexamethasone . No particles were detected in untreated cultures of Tera-1 cells or in any preparations of Tera-2 cells. J Gen Virol, 1979 Aug, 44(2), 457 - 69 Characterization of infection and replication of Mason-Pfizer monkey virus in human cell cultures; Fine DL et al.; Human cells derived from both normal and neoplastic tissues can be infected by Mason-Pfizer monkey virus (MPMV) without accompanying cytopathology . Infection of cell cultures such as human rhabdomyosarcoma (A204) results in a persistenly infected cell line which can be subcultured over 30 sequential culture passages without significant change in phenotype properties according to reverse, transcriptase (RT), MPMV p27 antigen content, virus particle count and infectivity titre . Productive virus infections were established at relatively low virus particle (VP) input multiplicities (p.i.m.; about 0.06 VP/cell) In A204 cell cultures . At higher p.i.m . (about 600 to 6000 VP/cell) newly synthesized virus was detected within 4 days post infection . Although virus production was cumulative following primary infection, after subculture of infected cultures MPVM production was greater during active cell division . Using synchronization techniques, MPMV replication in persistently infected cultures was found to be cell cycle-dependent . The major internal antigen, p27, was synthesized in G2 and newly synthesized virus particles were released predominantly during mitosis and early G1 . Colcemid arrest of cells during mitosis inhibited subsequent MPMV release . Consequently, production of extracellular virus depends upon the progression of cells through the mitotic stage . These data, which provided a basic understanding of the virus-host relationship that occurs in primate cells productively infected with MPMV, were used as a guideline for isolating MPMV-like viruses from experimentally and naturally infected Rhesus monkey. J Clin Microbiol, 1979 Aug, 10(2), 235 - 9 Effects of cell culture and laboratory conditions on type 2 dengue virus infectivity; Manning JS et al.; The stability of type 2 dengue virus to exposure to a variety of laboratory conditions was determined . Suckling mouse brain passage virus was adapted for growth in BHK-21 cells, and plaque assays were performed using a tragacanth gum overlay . A three- to fourfold increase in plaque size could be obtained if monolayers were subconfluent at time of inoculation . Incubation of virus for 24 h at 37 degrees C, pH 6.5, or in buffer containing 1 mM ethylenediaminetetraacetate considerably reduced virus infectivity as compared with virus incubated for the same period at 4 degrees C, pH 8.0, or in buffer with or without 1 mM CaCl2 and 1 mM MgCl2 . Multiple freezing and thawing of virus tissue culture medium containing 10% fetal calf serum did not reduce virus infectivity. Hum Genet, 1979 Jul 18, 49(3), 327 - 32 Chromosome lesions in amniotic fluid cell cultures; Simoni G et al.; The frequencies of chromosome lesions were determined on 3537 mitoses in samples of varying sizes from cultures of 25 amniotic fluid specimens taken from patients at cytogenetic risk . The average percentage values of aberrant cells, including and excluding gaps, were 12.5 and 4.9, respectively . The corresponding values for fibroblasts and peripheral blood lymphocytes from normal adult donors, calculated under the same laboratory conditions, were 5.0 (including gaps) and 2.4 (excluding gaps) and 2.4 (including gaps) and 1.0 (excluding gaps), respectively . The hypothesis of a correlation between the increased incidence of chromosome lesions and the occurrence of abnormal karyotypes in amniotic fluid cell cultures is discussed. Histochemistry, 1979 Jul 11, 61(3), 263 - 70 Development of neurons containing acetylcholinesterase and cholinacetyltransferase in dispersed cell culture of rat cerebellum; Kasa P et al.; Cells from one-day-old cerebellum were grown for up to 30 days in dispersed cell culture . The characteristic neurons (deep cerebellar, Golgi and Purkinje cells) maintained their properties . It was found histochemically that some of the large cells display strong AChE activities in the perikaryon and in some processes, while biochemically the specific activities of the marker enzymes of the acetylcholine system, AChE (EC 3.1.1.7) and ChAc (EC 2.3.1.6), were increased and unchanged, respectively . During cultivation, the number of AChE-positive neurons increased . It can be inferred from these studies that, besides the AChE-positive (cholinoceptive) cells, ChAc-active (cholinergic) neurons (possibly Golgi II . type cells and some neurons in the deep cerebellar nuclei) are present in the cerebellum of the rat. Neurosci Lett, 1979 Jul, 13(2), 157 - 61 Na-dependent Li-transport in primary nerve cell cultures; Szentistvanyi I et al.; Primary cultures from chick embryonic brain were used to study the steady state distribution of lithium . The intra/extracellular Li+ ratio decreased by enhancing the external Na+ concentration . Ouabain did not influence this unequality . A phloretin-sensitive component was revealed in the Li uptake at low Na+ concentration . The findings might suggest the existence of a Na+-dependent Li+ countertransport system in these brain cell cultures. J Biochem (Tokyo), 1979 Jul, 86(1), 111 - 9 Modulation of glycosaminoglycan synthesis during cell growth as observed in an embryonic chick tendon cell culture; Ninomiya Y et al.; Glycosaminoglycan synthesis during cell growth has been studied in terms of unit cell numbers, using 16-day-old embryonic chick tendon cell cultures . Hyaluronic acid production was found to be inversely proportional to the cell density, while the levels of sulfated-glycosaminoglycan synthesis remained constant . On the other hand, hyaluronic acid production remained constant during cell proliferation, though chondroitin sulfate synthesis increased rapidly during an actively growing phase of the cultured cells, and dermatan sulfate and heparan sulfate syntheses increased gradually. In Vitro, 1979 Jul, 15(7), 537 - 44 Cell cultures derived from embryos and melanoma of poeciliid fish; Kuhn C et al.; In poeciliid fish, melanoma of different degrees of malignancy can be produced by crossing specific genotypes . For a detailed investigation of the processes leading to proliferation or differentiation of the melanoma cells, it is necessary to establish cell cultures . The aim of the present study was to find out the optimal conditions for initiating and culturing poeciliid fish cells for the purpose of establishing cell cultures of melanoma . The optimal method was developed by using small pieces of late embryos as starting material and includes: (a) dispersion of tissue by mild stepwise treatment with a trypsin-EDTA mixture at low temperature; (b) culture of cells in the complex medium 199; (c) supplementation of medium with high percentage (20%) of fetal bovine serum; and (d) stabilization of pH by buffering the medium with HEPES . Under these conditions, primary and secondary cultures of embryonic cells have been initiated . An epithelial-like cell line has been subcultured for more than 80 passages . The method developed for embryonic tissues was used to start cell cultures from melanoma of platyfish-swordtail hybrids . Until now, only cells of rapidly growing malignant albino melanoma could be maintained in primary cultures . Secondary cultures could not be initiated since the melanoma cells tended to differentiate and stopped growing before a confluent monolayer was formed. In Vitro, 1979 Jul, 15(7), 522 - 30 Studies of alpha-protein in human cell cultures; Holmes R et al.; alpha-Protein growth fraction (AGF) eliminates the 60- to 90-day adaptive phase required to establish actively growing cultures of HeLa (Gey), human heart (Girardi), KB (Eagle) and other established cell lines in serum-free chemically defined medium A3 . AGF is effective at less than 0.4 microgram per ml . By using the procedures described in the text, it is possible to culture HeLa cells in very simple media such as Eagle's basal medium . The properties of AGF are such that it may be adsorbed on glass or plastic flasks . Glass flasks treated with AGF retain full activity after washing with acetone, and treatment with ethyl ether and chemically defined medium . Adsorbed AGF is destroyed by trypsin . AGF can detoxify protamines, polylysines or histones . It will reverse the aggregation response induced by adding complexes composed of carboxymethylcellulose (CMC) and basic proteins . The results support the contention that highly adsorptive AGF functions at the cell surface and is capable of modifying the response of the cell to its environment. In Vitro, 1979 Jul, 15(7), 503 - 6 Lactoperoxidase-catalyzed iodination of cell cultures infected with mycoplasma; Lanks KW et al.; Hamster BHK cells or secondary cultures of mouse embryo fibroblasts are not iodinated by lactoperoxidase in the absence of hydrogen peroxide . When such cell cultures are infected with a noncultivable strain of M . hyorhinis, endogenous peroxide generation is sufficient to permit nearly maximal iodination . The SDS-polyacrylamide gel pattern of iodinated cell surface polypeptides is essentially the same regardless of the source of peroxide and whether or not the cultures are infected with mycoplasma. Vopr Virusol, 1979 Jul-Aug, (4), 409 - 14 {Virus-specific RNA synthesis in a cell culture in acute and chronic infection with the tick-borne encephalitis virus}; Andzhaparidze OG et al.; Virus particles produced in acute and chronic infection of cell cultures with tick-borne encephalitis virus (TBE) and examined by centrifugation in sucrose density gradient had the buoyant density of 1.19 g/ml and sedimentation constant 290 S . Studies of the synthesis of virus-specific RNAs in the cytoplasm of TBE virus chronically infected cells revealed synthesis of all RNA classes typical of TBE virus reproduction in acutely infected cells . The difference was in the high percentage of polyadenylation of intracellular virion RNA in chronic infection (30%) as compared with polyadenylation of virion RNA in acute infection (8%) . This fact may be one of the causes of a low infectious virus yield in chronically infected cultures where the level of virus-specific antigen synthesis is high. Cell Biol Int Rep, 1979 Jul, 3(4), 359 - 71 Effect of hormones on primary cell cultures from pregnancy-dependent mouse mammary tumors; Aidells BD; No hormone combination was successful in maintaining long term primary cultures of pregnancy-dependent mammary tumors . Insulin provided the most consistent dose dependent stimulatory effect on short term proliferation as measured by 3H-TdR incorporation into DNA . Insulin in combination with corticosterone and prolactin produced the greatest stimulatory effect in most tumors . Both insulin at 5 microgram/ml and insulin, prolactin and hydrocortisone induced a partially synchronous wave of DNA synthesis in restimulated cultures . The time course of the wave of DNA synthesis was different for different hormone treatments . Insulin as 5 microgram/ml caused an earlier wave of DNA synthesis than insulin, prolactin plus corticosterone. Cell Biol Int Rep, 1979 Jul, 3(4), 345 - 57 Growth in short term primary cell cultures derived from pregnancy-dependent mammary tumors; Aidells BD et al.; The behavior of cells in primary cultures derived from autonomous and pregnancy-dependent mouse mammary tumors was studied . Despite initial growth both dependent and autonomous mammary tumors produced only short-term primary cultures . Initial plating density had a marked effect on growth with only cultures plated at greater than or equal to 2 X 10(5) cells/cm2 showing any short-termed growth . Time lapse analysis showed that the lack of growth was due to failures of cytokinesis and increased death rate and intermitotic time in cultures plated at less than 2 X 10(5) cells/cm2 . Using continuous label autoradiographic techniques, a partial synchronous wave of DNA synthesis was observed with newly plated and restimulated cultures . DNA synthesis reached a peak 24-48 hrs . after plating or restimulation and then dropped to low values for the next few days . Attempts to maintain the initial high rate of DNA synthesis or to induce another round of DNA synthesis by enriched media, increased serum concentrations, or other types of serum and plasma were at best only partially successful . Important hormones necessary for growth of mammary tissue in vivo may be necessary for sustained growth in vitro. J Clin Invest, 1979 Jul, 64(1), 32 - 9 Increased glycosaminoglycan accumulation as a genetic characteristic in cell cultures of one variety of dominant dystrophic epidermolysis bullosa; Bauer EA et al.; Fibroblast cultures from patients with dominant dystrophic epidermolysis bullosa of the albopapuloid variety display deranged glycosaminoglycan metabolism . These cells accumulate increased amounts of sulfated glycosaminoglycans . The mechanism for the greater content of glycosaminoglycans appears to be related to increased synthesis . During the first 6-12 h, intracellular labeled glycosaminoglycans accumulated in the dominant dystrophic epidermolysis bullosa cells at about twice the rate as that of control fibroblasts . In addition, secretion of sulfated glycosaminoglycans was two- to threefold greater than in control cultures . In contrast, both pulse-chase and cross-correction experiments failed to show any evidence for defective degradation of the material . The biochemical trait is genetically specific for albopapuloid dominant dystrophic epidermolysis bullosa, since fibroblasts from patients with other varieties of epidermolysis bullosa did not accumulate increased glycosaminoglycans . The data suggest that in vitro abnormality in glycosaminoglycan metabolism could serve as an important marker for this variety of epidermolysis bullosa and be of genetic and prognostic value in the sporadic patient with epidermolysis bullosa . Although the precise relationship of the defect to the disease has not yet been defined, it is possible that excessive tissue accumulation of glycosaminoglycans may alter collagen fibril deposition, thus, impairing the structural integrity of the skin and leading to posttraumatic blisters and erosions that characterize the disease. Endocrinology, 1979 Jul, 105(1), 80 - 5 Depletion of L-3,5,3'-triiodothyronine and L-thyroxine in euthyroid calf serum for use in cell culture studies of the action of thyroid hormone; Samuels HH et al.; GH1 cells are a clonal strain of rat pituitary tumor cells which synthesize GH and PRL . We have previously demonstrated that these cells respond to physiological concentrations of L-T3 and L-T4 when cultured with medium supplemented with thyroidectomized calf serum to achieve a thyroid hormone-depleted state under cell culture conditions . In this study, we describe a method to deplete euthyroid calf serum of L-T3 and L-T4 using an anion exchange resin . We demonstrate that the procedure only minimally alters the low molecular weight anion components of the serum and does not change the total protein content or the electrophoretic pattern of serum proteins . Moreover, we show that euthyroid calf serum depleted of L-T3 and L-T4 by this procedure yields serum which, when used as a medium supplement, results in biological responses identical to those obtained with media supplemented with thyroidectomized calf serum . In addition, resin treatment does not alter the growth-promoting properties of the serum if the thyroid hormone concentration is restored . This procedure should be useful in preparing thyroid hormone-depleted serum for cell culture studies in situations where thyroidectomy is not feasible or would require surgical procedures on a large number of small animals. In Vitro, 1979 Jul, 15(7), 507 - 21 Endocrine pancreatic cells of postnatal "diabetes" (db) mice in cell culture; Leiter EH et al.; Ultrastructural characteristics as well as secretory and biosynthetic behavior of monolayer pancreatic cell cultures established from 4-day-old C57BL/KsJ misty diabetic (m db/m db) mice have been studied in comparison to normal littermate controls . Hypersecretion of glucagon by alpha-cells from BL/Ks misty diabetic mice after 2 days in vitro was found to precede any hyperfunction of the insulin-secreting beta-cells . The increased level of glucagon-release in BL/Ks cell cultures from diabetic mice was accompanied by a greatly enhanced level of incorporation of {3H}tryptophan into glucagon-like molecules whose specific radioactivity was up to 15-fold higher than that observed in cultures from genetic controls . The finding of an alpha-cell dysfunction in cultures established from preweaning diabetic BL/Ks mice suggests that glucagon could play an early role in shaping the events that culminate in the expression of frank diabetes in this inbred strain. Exp Hematol, 1979 Jul, 7(6), 315 - 23 Friend virus production and heme synthesis in primary mouse spleen cell cultures; Menna JH et al.; A cell culture method has been developed in which spleen cells from Friend virus (FV) infected mice can be studied for virus production as well as erythroid differentiation . Primary spleen cell cultures from plethoric Balb/c mice were initiated at 24, 48 or 73 h after FV infection . These cells manifested a well-defined wave of heme synthesis at approximately 64, 48, or 23 h, respectively, of cell culture . Assays for spleen focus-forming virus (SFFV) and helper murine leukemia virus (MuLV-F) production in these cultures revealed that the peak rates of production of both viruses occurred at essentially the same time as the peaks of heme synthesis . The time at which the peaks of virus production and heme synthesis occurred in vitro was related to the time interval after infection (80-105 h) rather than the time at which the cells were placed in cell culture or the number of hours of cell culture . Medium change experiments suggested that the temporal relation between heme synthesis and virus production was an intrinsic feature of FVP infected cells in this in vitro system. Vopr Virusol, 1979 Jul-Aug, (4), 389 - 92 {Human rotavirus in cell culture: its isolation and passage}; Drozdov SG et al.; Rotavirus was isolated from feces of patients and passaged in green monkey kidney cell subculture using the factors affecting the initiation of infection of tissue culture cells with human rotavirus . The effective factors were found to include the presence of low concentrations of trypsin in the infected culture and virus centrifugation of a cell layer which agreed with the data by Almeida et al . (1978) and Shoub and Bertran (1978) obtained in other cell systems . Immune electron microscopy was used to detect the virus in cell cultures and to prove its specificity. Vopr Virusol, 1979 Jul-Aug, (4), 358 - 62 {Relationship of the characteristics of the chromosome set in human cell cultures to the production and antiviral action of interferon}; Khesin IaE et al.; The role of chromosomes 2, 5, 16, and 21 in production and effect of human interferon was checked in human diploid cells, human heteroploid cells J-96 and clone J-41 thereof . The J-41 cells were found to have a lower number of chromosomes 2 as compared to the other cells under study; J-41 cells produce less interferon than the other cells . Most J-41 cells lack chromosome 21 . Unlike the other two cell cultures, these cells do not produce antivirus state after treatment with interferon . The number of chromosomes 16 is larger in J-96 cells than in diploid ones, and they are less sensitive to interferon than diploid cells . The experimental results confirm the importance of chromosome 2 for coding for interferon production, other chromosomes taking part in the regulation of this process . The gene of sensitivity to interferon is localized in chromosome 21, the regulator gene coding the production of repressor of sensitivity to interferon is in chromosome 16. Endocrinology, 1979 Jul, 105(1), 156 - 62 Production of long term steroid-producing granulosa cell cultures by cell hybridization; Zeleznik AJ et al.; Primary cultures of rat ovarian granulosa cells have been used extensively to study hormonal regulation of cellular function . To date, no long term cultures of ovarian cells which retain their differentiated functions have been developed . Hypoxanthine guanine phosphoribosyl transferase-deficient simian virus 40-transformed rat ovarian granulosa cells were fused with freshly prepared rat granulosa cells using inactivated Sendai virus . Putative hybrid cell strains obtained after selection in medium containing hypoxanthine, aminopterin, and thymidine were analyzed for progesterone synthesis . Neither the original simian virus 40-transformed granulosa cell nor its hypoxanthine guanine phosphoribosyl transferase-deficient derivative produced progesterone, but three of the hybrid strains produced progesterone at basal levels and in response to dibutyryl cAMP . One of these strains produced progesterone in a dose-responsive fashion when exposed to prostaglandin E2, cholera toxin, dibutyryl cAMP, and 2-chloroadenosine . Cell strains obtained by hybridization were remarkably similar to primary cultures of granulosa cells with respect to both the magnitude and temporal aspects of progesterone production in response to dibutyryl cAMP. Virologie, 1979 Jul-Sep, 30(3), 185 - 8 Computer-operated scanning analysis of FITC-labelled measles virus in cell cultures; Korting HJ et al.; FITC-labelled measles virus antigen in infected cells was analysed by computer-operated scanning fluorometry, printed out by a mosaic printer according to a predetermined classification, and by a coordinate-recorder as a perspective image . The three-dimensional print-out of the topographic distribution of antigen accumulations in the cells can be optimized by a variation of the angle of view. J Assoc Off Anal Chem, 1979 Jul, 62(4), 904 - 16 Induction of enzyme activity in cell culture: a rapid screen for detection of planar polychlorinated organic compounds; Bradlaw JA et al.; Induction of aryl hydrocarbon hydroxylase (AHH) activity in rat hepatoma cell line serves as a simple and rapid method to detect minute (pg) amounts of certain classes of compounds, e.g., dibenzo-p-dioxins, dibenzofurans, and biphenyls . This method may provide a quick screen for such substances in extracts from foods prior to chemical identification . AHH activity is measured by conversion of benzo{a}pyrene (BP) to 3-hydroxy BP in homogenized cell extracts from control and treated cultures and is reported as pmol product formed/mg protein/min . Substances screened by this method include polyhalogenated analogs of dibenzo-p-dioxin (24 compounds), dibenzofuran (11 compounds), biphenyl (7 compounds), and extracts from several food sources . Response of the most reactive compound, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was used to prepare a standard curve, and the AHH activity induced by mole doses of test substance is reported as an ED50 response (the estimated dose needed to produce 50% maximum enzyme induction) . The AHH activity induced by food extracts is equated to the standard curve and reported as TCDD equivalents . A potent ED50 response in cell culture appears to correlate well with known toxic responses in other mammalian and avian systems for certain test substances . This correlation suggests that the cell culture enzyme induction method is a useful model for screening food extracts that are suspected to be contaminated with polychlorinated planar substances . A collaborative study would demonstrate the reproducibility of the method. Vopr Virusol, 1979 Jul-Aug, (4), 346 - 52 {Isolation and study of influenza A viruses in different cell cultures}; Demidova SA et al.; The usefulness of some cells cultures (BSC-I, VERO, MDSK) for isolation and study of reproduction of influenza A viruses was explored . Out of 50 clinical specimens examined, in 16 cases the virus was isolated both in chick embryos and in MDSK cell cultures . MDSK cultures were found to be highly sensitive to influenza A viruses, which produced cytopathic effect and hemagglutinin accumulation . The plaques formed by freshly isolated strains under an agar overlay containing trypsin were markedly polymorphous . MDSK cells may be recommended for use in virus isolation studies . Examinations of virion morphology revealed their diversity both in size and shape. Arch Dermatol Res, 1979 Jun 25, 265(2), 181 - 7 Pure melanocyte cultures: differential serum requirements of guinea pig keratinocytes and melanocytes in primary epidermal cell cultures; Fritsch P et al.; Contrary to melanocytes guinea pig keratinocytes do not attach and grow in primary epidermal cell cultures if plated in media containing guinea pig serum . This phenomenon is based on the low content or lack of guinea pig serum of a factor(s) promoting keratinocyte attachment . This factor, which is contained in fetal calf serum, binds to the keratinocyte cell surface and can be removed by trypsin . Guinea pig epidermal cell cultures plated in medium containing guinea pig serum therefore lead to pure or almost pure melanocyte cultures. Biochim Biophys Acta, 1979 Jun 2, 553(3), 424 - 37 Translocation and turnover of phospholipid analogs in plasma membrane-derived vesicles from cell cultures; Yavin E et al.; The time-dependent accumulation of phosphatidyldimethylethanolamine in formaldehyde-induced vesicles obtained from a somatic cell hybrid line was investigated . From a number of considerations including a two-fold enrichment of cholesterol and sphingomyelin it was concluded that these vesicles were derived from the cell plasma membrane . A progressive depletion of phosphatidylcholine, the major vesicle phospholipid, was observed in cells supplemented for various time periods with dimethylethanolamine . This depletion was accompanied by a concomitant increase in the amount of lipid analog . The time-dependent alteration of the phospholipid polar head group in intact cells was almost identical to that observed in isolated plasma membrane vesicles, suggesting a rapid equilibration of the de novo synthesized phospholipid with the cell surface compartment . From the initial velocity rate, the time required for the phosphatidylcholine pool to double was about 12 h . Agarose-linked phospholipase A2 was used to measure the relative composition of choline- and dimethylethanolamine-phosphoglycerides in the outer surface of vesicles prepared from cells with different degrees of polar head group substitution . The gradual appearance of lysodimethylethanolamine lipid analog in vesicles treated with phospholipase A2 suggested an asymmetric distribution of the phospholipid between the interior and the exterior part of the vesicle . This asymmetry was maximal up to about 4 h following the addition of dimethylethanolamine to the culture medium and was of a transient nature as the lipid analog accumulated on both sides of the plasma membrane . Based on these measurements a fast followed by a slow translocation component could be distinguished with apparent doubling times of 7 and 43 h for the lipid analog, respectively . As the analog becomes the predominant cellular phospholipid a significant increase in the vesicle lipid fluidity was measured. Cardiovasc Res, 1979 Jun, 13(6), 345 - 53 Release of alpha hydroxybutyrate from neonatal rat heart cell cultures exposed to anoxia and reoxygenation: comparison with impairment of structure and function of damaged cardiac cells; Van Der Laarse A et al.; Spontaneously beating monolayer cultures of neonatal rat heart cells first exposed to depletion of oxygen and metabolic substrates for 1 to 7 h (anoxia) . Subsequently the cultures were resupplied with oxygen and substrates (reoxygenation) . The release of alpha-hydroxybutyrate dehydrogenase (HBDH) from the cells, the extent of necrosis, and the changes in spontaneous contractile activity were measured . HBDH release was observed to start after 1 h of anoxia and to increase to 84% of intracellular HBDH activity after 7 h of anoxia . Reoxygenation of anoxic heart cells is associated with accelerated HBDH release (oxygen paradox) . The activity of HBDH released by cardiac cells, the number of necrotic cells and the impairment of beating capacity of the cells depend on the duration of the anoxic period in a similar way . This study demonstrates that cardiac cell death can be assessed quantitatively and reliably by the measurement of the activity of HBDH released by the cells. J Cell Physiol, 1979 Jun, 99(3), 451 - 60 Membrane effects of tumor promoters: stimulation of sugar uptake in mammalian cell cultures; Lee LS et al.; Phorbol esters stimulate 2-deoxy-D-glucose (DG) uptake in rodent and human cell cultures . The potent tumor promoting agent, 12-0-tetradecanoyl phorbol-13 acetate (TPA), induces a 12-fold stimulation in confluent 3T3 cells and 2.5-fold stimulation in HeLa cells . When a series of macrocyclic deterpenes are assayed, their relative potencies in stimulating DG uptake in 3T3 cells correlate with other known biologic effects of these compounds . On a molar basis, TPA is a much more potent stimulator of DG transport than insulin or epidermal growth factor . In HeLa cells, the ED50 value of the TPA effect is 0.2 nM . The increase in DG uptake occurs immediately after the addition of TPA, reaches a maximum at 90 minutes, persists for at least three hours after removal of TPA from the medium, and is temperature dependent . The stimulation is not inhibited by cycloheximide or actinomycin D . As in control cells, DG uptake in TPA treated cells is inhibited by p-hydroxymercuribenzoate, phyloridzin, cytochalasin B, and dexamethasone . Although the precise mechanism is not known, evidence is presented that the TPA stimulation of DG uptake is due to enhanced transport of the sugar rather than to effects on intracellular metabolism . The enhanced transport may be secondary to a more generalized change in membrane structure. Neurosci Lett, 1979 Jun, 13(1), 35 - 40 Immunofluorescent localization of microfilaments in neuronal and glial primary cell cultures with antibody against adrenal medullary myosin; Aunis D et al.; The localization of myosin was studied in rat neuronal and glial cell maintained in primary culture, using the double antibody immunofluorescent method . Antibodies were raised against myosin purified from bovine adrenal medulla . Myosin-specific immunoreactivity was found in the cell body and neurites of neuronal cells and in the cytoplasm of glial cells . In the former no typical substructure was observable, whilst in the latter myosin-rich filaments were found forming either a cage entrapping the nucleus or as long cables in cellular morphogenic expansions. J Clin Microbiol, 1979 Jun, 9(6), 731 - 3 Collagenase in equine cell culture preparation; Lang G; Equine kidney cells disaggregated by treatment with 0.01% collagenase were used in the preparation of primary monolayer cell cultures . The primary cells could be stored for long periods in liquid nitrogen and subsequently subcultivated . These techniques provided a long-term supply of equine kidney cells, free of apparent contamination, from the kidneys of a single fetus. Invest Ophthalmol Vis Sci, 1979 Jun, 18(6), 588 - 601 Collagenase from corneal cell cultures and its modulation by phagocytosis; Berman M et al.; The uptake of latex by fibroblasts in confluent primary culture results in the secretion of collagenase at a linear rate for a prolonged period . Phagocytosis might therefore constitute an important level of collagenase regulation in corneal ulceration . The collagenase in cell cultures is present in a latent form (40,000 MW) like that obtained from organ cultures of ulcerating corneas and can be activated proteolytically . Production of the latent collagenase in cell culture depends upon the presence of serum and diminishes greatly when serum is removed from the medium . Collagenase activity can be demonstrated after the latent collagenase has been separated from serum antiproteases in the media . Alternatively, careful titration of the crude media with trypsin to saturate serum antiproteases, to release collagenase from the complex with alpha 2-macroglobulin, and to activate latent collagenase also results in measurable collagenase activity . The collagenase that is secreted cleaves fibrillar type I collagen and cleaves soluble type I collagen into the typical 3/4 and 1/4 length fragments, as demonstrated by SDS-gel electrophoresis and electron microscopy. Experientia, 1979 May 15, 35(5), 601 - 2 Tick-borne encephalitis virus-specified sequences in persistently infected cell culture revealed by DNA-DNA hybridization; Andzhaparidze OG et al.; Hybridization of DNA probe, obtained through DNA polymerase-mediated in vitro transcription of tick-borne encephalitis virus (TBEV) RNA, with DNA isolated from persistently infected with TBEV cell culture revealed 5.4 copies of viral genome per haploid set. Med Microbiol Immunol (Berl), 1979 May 15, 167(2), 117 - 26 Normal and pseudorabies virus infected primary nerve cell cultures in scanning electron microscopy; Bijok U et al.; Primary cell cultures from the central nervous system of the embryonic rat were inoculated with pseudorabies virus . Their morphological changes were studied by phase contrast microscopy and by scanning as well as by transmission electron microscopy . Uninfected cultures display two distinct cell layers in scanning electron microscopy: a flat continuous monolayer supports a heterogeneous population of individual, presumably neural cells, which emit processes of different number and size . The latter cells form contacts by a dense network of fibres . Infectious virus is propagated in these nerve cell cultures with similar effectivity as in other cultures . The infectoin leads to fusion and death of the cells . By the time the cytopathic effect is visible, nearly all cells, including those of neuronal and those of nonneuronal appearance, are studded with ample amounts of virus-sized particles . The particles represent viruses as demonstrated by transmission electron microscopy or by treatment with a hyperimmune serum directed against pseudorabies virus structural components . Hyperimmune serum leads to clustering of the particles at the cell surface . The amount of virus particles per surface unit was about 10 times higher on neural cells as compared to primary rabbit kidney cells . The concentration of infectious particles in the supernatant, however was approximately the same . The system described appears to be useful for the study of acute virus effects on neural tissue under strictly controlled conditions. J Histochem Cytochem, 1979 May, 27(5), 939 - 41 Immunohistochemical characterization of monolayer cell cultures of embryonic chicken pancreas and measurement of somatostatin release; Barden N et al.; Monolayer cell cultures of embryonic chicken pancreas contain functionally active insulin, glucagon and somatostatin-containing cells as evidenced by immunohistochemical and radioimmunoassay techniques . Hormone release is in relation to the number of each cell type present and responds to known specific secretory stimuli . The relatively high numbers of D-cells and amounts of immunoreactive somatostatin released by this preparation makes this system a suitable model for studies of somatostatin function and secretion. In Vitro, 1979 May, 15(5), 374 - 82 Normal human endometrium in cell culture . II . A microspectrophotometric study of polyploid nuclei in short-term primary epithelial cultures; Kirk D et al.; The growth of short-term primary cultures of endometrial epithelium has been studied using Feulgen microspectrophotometry . A gradual increase in the number of polyploid nuclei up to 64C has been observed and is associated with a decline in the growth capacity of the cultures . The specific mechanism(s) of this polyploidization is not known. Cancer Lett, 1979 May, 6(6), 351 - 5 Lack of oestradiol-DNA binding in mouse embryo cell cultures or following rat-liver microsomal metabolism; Duncan SJ et al.; Oestradiol-17beta was compared to benzo{a}pyrene (BP) for its ability to bind to the DNA of mouse embryo cells in culture or to DNA added to a rat liver microsomal incubation mixture . No significant binding was found in embryo cells (at least 100-fold less than for BP) . Microsomal incubation resulted in apparent oestradiol binding to a reisolated DNA-containing complex, but most of this was lost when the DNA was freed of RNA and protein. Clin Genet, 1979 May, 15(5), 441 - 3 Trisomy 20 mosaicism in amniotic fluid cell culture; Nevin NC et al.; Chromosomal mosaicism in cultured amniotic fluid cells presents one of the most difficult problems in prenatal diagnosis in predicting the foetal phenotype . We present a case in which trisomy 20 mosaicism was diagnosed prenatally but not confirmed in the aborted foetus. Immunology, 1979 May, 37(1), 45 - 52 The use of the enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of specific antibody from cell cultures; Kelly BS et al.; The solid phase enzyme linked immunosorbent assay (ELISA) has been used to quantify anti-keyhole limpet haemocyanin (anti-KLH) antibody in the serum of KLH-immune C57Bl/6 mice . When spleen cells from immune mice were cultured overnight in ELISA microtitre wells to which KLH had been adsorbed it was found that easily quantifiable amounts of anti-KLH antibody were synthesized and were detectable . It was found further that spleen cells from KLH-primed mice, when cultured in vitro in the presence of KLH, transferred to KLH-labelled ELISA plates, and cultured overnight, also produced detectable levels of antibody . Levels of antibody were detectable only after 4 and 5 days of in vitro stimulation . A comparison was made between detectable numbers of plaque forming cells to sheep red blood cells (SRBC) in SRBC primed CBA mice and levels of antibody detected by the ELISA procedure . It was found that the sensitivities of the two tests were comparable . The applications of this technique to the study of in vitro antibody synthesis using soluble antigens are discussed. Vopr Virusol, 1979 May-Jun, (3), 283 - 5 {Morphological data on the reproductive characteristics of the LEIV-108A and LEIV-3306 Uz strains of the Baku virus in chick fibroblast cell culture}; Gushchina EA et al.; Electron microscopic examinations of chick fibroblast cells 24 hours after inoculation with LEIV-108A and LEIV-3306 Uz strains of Baku virus revealed the following: in the nuclei of the cells infected with the LEIV-108A strain fine granular matrices were found and virus particles were forming at the periphery of the nucleus; in the LEIV-3306Uz-infected cells virus particles were found budding from the plasma membrane of the cell. In Vitro, 1979 May, 15(5), 329 - 41 Long-term in vitro cell culture of Sinclair swine melanoma; Kovacs SH et al.; The melanoma of Sinclair swine exhibits several characteristics similar to human melanoma but demonstrates an unusually high incidence of spontaneous regression . A total of 66 finite cell lines derived from 21 swine melanotic lesions, both cutaneous and visceral, were studied in vitro over their life spans of up to 14 months . The growth characteristics of the cultures varied with the age of the swine from which the tumors were obtained . Cell cultures of tumors obtained from swine aged less than 2 months grew steadily in cluture with a population-doubling time of 120 to 180 hr until growth and division ceased after a maximum of 25 to 35 population doublings (6 to 8 passages) . Cell cultures of tumors obtained from swine aged 3 months or older showed a biphasic growth pattern with an early slow growth rate (population-doubling time 120 to 160 hr), which shifted after 3 to 6 passages to a faster rate (80 to 110 hr population-doubling time) until termination of growth and division after a maximum of 75 to 85 population doublings (18 to 20 passages) . The cultures were morphologically heterogeneous including cuboidal, spindle and dendritic cell types . Electron microscopy showed classic melanosomes only in the primary and passage 1 cultures although vesicular inclusions were numerous in later-passage cells . However, continued melanin synthesis was indicated by the spectroscopic characteristics of material obtained from medium of passage 8 cultures and by DOPA staining of cultures as advanced as passage 18. Acta Virol, 1979 May, 23(3), 203 - 9 Antiviral activity of benzothiazole and benzothiazolinethione derivatives in cell cultures; Rada B et al.; The virus inhibitory activity of benzothiazole, benzothiazolinethione and naphthothiazole derivatives was tested with vaccinia virus, Newcastle disease virus (NDV) and western equine encephalomyelitis (WEE) virus in the agar-diffusion plaque-inhibition test . Among 58 compounds examined, 5 showed medium activity and selectivity with vaccinia virus . The highest selective effect was found with 3-(2-ethylthio-6-benzothiazolylaminomethyl)-2-benzothiazolinethione . A much lower inhibitory effect was observed with several derivatives against WEE virus . One derivative (2-mercaptobenzothiazole) showed a low inhibitory effect against NDV. Biochim Biophys Acta, 1979 Apr 26, 562(2), 292 - 301 Partial base-methylation and other structural differences in the 17 S ribosomal RNA of sycamore cells during growth in cell culture; Miassod R et al.; Sycamore (Acer pseudoplatanus L.) cytoplasmic rRNA was investigated in rapidly dividing cells, cells starting mitosis after the lag phase of growth (4 days) induced by deconditioning of the culture medium and also in growth-arrested cells from 10 day-old cultures deprived of exogenous auxin (i.e . exponential, early exponential and 2,4-dichlorophenoxyacetic acid (2,4-D)-deprived cultures) . rRNA was extracted and purified from mixed 14C-labelled exponential cultures and 3H-labelled early exponential cultures . A 14C-labelled exponential culture and a 3H-labelled 2,4-D-deprived culture were analyzed in the same way . The 17 S rRNA molecules from both early exponential and 2,4-D-deprived cultures displayed a lower electrophoretic mobility on polyacrylamide gels than those from exponential cultures . Alkaline and acid hydrolysates of purified 17 S rRNA labelled on the phosphate groups or the methyl groups were analyzed on ion-exchange resins . There was no change in the extent of ribose methylation of the molecule from the three different cultures . However, the base methylation of the 17 S rRNA was decreased in early exponential cultures and in 2,4-D-deprived cultures . Part of the molecules synthesized in early exponential cultures specifically lacked 7-methylguanine, N6-methyladenine and N6,N6-dimethyladenine . The possible significance of these changes in the 17 S rRNA were discussed. Science, 1979 Apr 13, 204(4389), 176 - 7 Dexamethasone stimulation of metallothionein synthesis in HeLa cell cultures; Karin M et al.; HeLa cells in culture synthesize metallothionein . To investigate the effects of glucocorticoids on metallothionein synthesis we adapted HeLa cells to growth in a defined medium lacking hydrocortisone . In this defined medium, containing 1.5 x 10(-6)M Zn2+, dexamethasone (10(-6)M) caused a five- to sixfold increase in the synthesis of metallothionein . Progesterone (10(-5)M), a known antagonist of glucocorticoids, inhibited this response by 50 percent. J Neurocytol, 1979 Apr, 8(2), 239 - 59 Development of synaptic ultrastructure at neuromuscular contacts in an amphibian cell culture system; Weldon PR et al.; Cultures of dissociated myotomal muscle and spinal cord derived from embryos of Xenopus laevis were grown in the presence of curare in order to abolish neuromuscular activity and were examined by electron microscopy . In one-day-old cultures a few of the neuromuscular contacts already displayed several synaptic specializations including 500 A vesicles clustered against the axolemma, increased axolemmal densities, basal lamina in the cleft, an increased sarcolemmal density and subsarcolemmal filamentous material . Contacts with these specializations were observed more frequently in two and three-day-old cultures . Throughout the three-day culture period nerve fibres and neuromuscular contacts were devoid of Schwann cells . Isolated patches of basal lamina were relatively scarce and were usually accompanied by an increase in sarcolemmal density and subsarcolemmal filamentous material even in cultures in which spinal cord cells were not included . These observations indicate that the myotomal neuromuscular synapse differentiates in culture in much the same way as it does in vivo, that muscle contractions are not required for its differentiation, and that apparent postsynaptic specializations can develop in the absence of innervation. J Neurocytol, 1979 Apr, 8(2), 229 - 38 The formation of gap and tight junctions between retinal pigment cells in cell cultures; Meller K; The reformation of the junctional complex of retinal pigment cells was studied after trypsin disaggregation and in vitro reaggregation . Control specimens show a zonula occludens (tight junction) with integrated gap junctions and very large macular gap junctions . Isolation after trypsination results in disaggregation of the large gap junctions and fragmentation of the tight junctions with disaggregation of their integrated gap junctions . After two to four days of incubation the restoration of the zonula occludens is complete . After approximately five days of incubation, large gap junctions are found with a patchy arrangement of particles similar to that seen in vivo. J Endocrinol, 1979 Apr, 81(1), 49 - 60 A bioassay for inhibin using pituitary cell cultures; Eddie LW et al.; A bioassay for inhibin based on the suppression of gonadotrophin releasing hormone (Gn-RH)-stimulated secretion of FSH by primary monolayer cultures of rat anterior pituitary cells is described . The cultures were exposed to standard or test materials for 3 days . The levels of FSH in the media were measured by radioimmunoassay after exposure for 6 h to a maximally stimulating concentration of Gn-RH (10 nmol/l) . The standard was prepared from ovine testicular lymph . Several preparations of proteins from gonadal tissues or secretions suppressed the levels of FSH in parallel with the standard . The levels of LH were also reduced but higher doses of active material were required . Non-specificity from cell damage and inactivation of Gn-RH have been excluded . The secretion of gonadotrophins by the pituitary cells was also inhibited by androgens, but not in parallel with the standard and secretion of LH was affected more than that of FSH . Control lymph protein preparations from castrated sheep had no detectable activity . The assay was sensitive and had adequate precision and practicability . It has proved useful for monitoring preliminary steps in the purification of inhibin. J Clin Microbiol, 1979 Apr, 9(4), 488 - 92 Enhancement of antigen incorporation and infectivity of cell cultures by human rotavirus; Schoub BD et al.; Infection of cell cultures with human rotavirus preparations was attempted and the effects of trypsin and low-speed centrifugation on antigen incorporation, as demonstrated by immunofluorescence and radioimmunoassay, were determined . In addition, the effect of viral aggregation on antigen incorporation was investigated by filtering viral preparations . Four strains of human rotavirus were employed, and the results were compared to those obtained with two tissue culture-adapted animal rotaviruses . Centrifugation and trypsin appeared to have little or no effect on infectivity of the tissue culture-adapted (simian rotavirus) or -adaptable (Nebraska calf diarrhea virus) strains, whereas centrifugation and viral aggregation appeared to be essential for the human viruses . In addition, trypsin enhanced antigen incorporation of the human strains to some extent . Infectivity for cell cultures and in vitro human rotavirus protein formation was demonstrated by {35S}methionine incorporation, and the specificity of this human viral protein was established by radio-immunoprecipitation. Antibiotiki, 1979 Apr, 24(4), 291 - 4 {Effect of dibasol and ascorbic acid on the antiviral activity of human interferon in cell culture}; Povolotskii IaL et al.; The antiviral effect of human lymphocytic interferon was studied in the primary culture of human embryonic fibroblasts in the presence of dibazol and ascorbic acid . It was found that dibazol and ascorbic acid in concentrations of 5 and 10 gamma/ml respectively were capable of increasing the antiviral effect of human interferon in homological cells . The assays of 13 lots of interferon showed that its average titer in the experiments with ascorbic acid was 2.5 times higher than that in the control . The assays of 21 lots of interferon showed that its average titer in the experiments with dibazol was 3 times higher than that in the control . It is suggested that an increase in the protective properties of interferon in the presence of dibazol and ascorbic acid is connected with their capacity for stimulating the intracellular production of DNA and protein . The data obtained indicate that dibazol and ascorbic acid may be recommended in the complex of therapy and prophylaxis of antiviral infections. Acta Med Okayama, 1979 Apr, 33(2), 81 - 90 Specificity of cultured anterior pituitary cells in detecting corticotropin releasing factor(s): the effect of biologically active peptides and neurotransmitter substances on ACTH release in pituitary cell cultures; Hashimoto K et al.; Biologically active peptides and neurotransmitter substances were added to anterior pituitary cell cultures to examine the presence of corticotropin releasing factor (CRF)-like activity . Hypothalamic extract (HE) induced significant dose-related increase of ACTH, and the lowest effective dose was 0.01 HE/ml . Other tested substances including luteinizing hormone-releasing hormone, thyrotropin releasing hormone, melanocyte stimulating hormone release inhibiting factor, somatostatin, substance P, neurotensin, beta-endorphin . leu-enkephalin, met-enkephalin, bradykinin, norepinephrine, dopamine, serotonin, acetylcholine, histamine, gamma-amino butyric acid or gamma-hydroxy butyric acid showed no CRF-like activity . Relatively high doses of lysine vasopressin, arginine vasopressin and angiotensin II increased the release of ACTH in pituitary cell cultures, but the maximal ACTH response was markedly less than with HE . These results indicate that cultured anterior pituitary cells are sensitive and fairly specific in detecting CRF(s) comparing with other detecting procedures. Arch Dermatol Res, 1979 Mar 31, 264(2), 243 - 7 Recent advances in epidermal cell cultures; Prunieras M; Among the many skin culture systems, three have been selected in this short review because of their specific potentials in dermatological research . H . Green cultures newborn human forsekin keratinocytes on a mouse 3T3 feeder layer . Keratinocytes grow and keratinize . The feeder cells release factor(a) which allows serial propagation of keratinocytes to be achieved . The cell yield is further increased by adding epidermal grohth factor . This system has already proved to be a potent tool for the study of keratinization at the molecular level . A . Freeman has described a system in which explants of adult human skin are cultured on the dermal aspect of dead split-thickness pig skin . Keratinocytes can be passaged several times . Their differentiation is remarkable: it includes the production of keratohyaline, membrane coating granules, pemphigus as well as pemphigoid antigens . This system is interesting in the study of epidermal morphogenesis and may be applicable to the treatment of burns . The culture of epidermal cells from adult guinea pig ear in comparison with that of dermal fibroblasts is being used to study the specificity of action of pharmacological compounds on growth and keratinization of epidermal cells . Furthermore, the isolation (and culture) of pure populations of basal cells appears as a promising approach to the study of the mechanisms which moderate epidermal cell proliferation. Biochim Biophys Acta, 1979 Mar 29, 572(3), 541 - 56 Inactive 3-hydroxy-3-methylglutaryl-coenzyme A reductase in broken cell preparations of various mammalian tissues and cell cultures; Saucier SE et al.; Preincubation of broken cell preparations from a variety of tissues and cell cultures resulted in an apparent increase in the level of 3-hydroxy-3-methylglutaryl-CoA reductase activity . However, apparent activation of the reductase in mouse liver, hepatomas and primary liver cell cultures was attributed largely to the loss, during the preincubation period, of an interfering enzyme, 3-hydroxy-3-methylglutaryl-CoA lyase . Among non hepatic cells and tissues (which did not contain appreciable lyase activity) the proportion of latent reductase was high in sonicates of fetal brain and in L cells and was independent of the level of total enzyme activity present . Activation of the reductase was blocked by hydroxymethylglutaryl-CoA and NADPH as well as by KF so that activation did not occur under the conditions of the enzyme assay . The enzyme was activated slowly at 4 degrees C, so that partial activation of the latent form occurred during isolation of the microsomal fraction by differential centrifugation . The reductase present in sonicates of cells with either a high or low proportion of the latent enzyme was inactivated by incubation with ATP and Mg2+ . Suppression of reductase activity in L cell cultures by treatment with 25-hydroxycholesterol and an age-related decline in brain enzyme activity did not involve reversible conversion of the reductase to an inactive form. Boll Soc Ital Biol Sper, 1979 Mar 15, 55(5), 427 - 33 {Effect of different oxygen pressure levels on the transport of alpha-aminoisobutyric acid in myocardial cell cultures}; Clo C et al.; The activity of aminoacid transport, as measured by alpha-aminoisobutyrate uptake, has been studied in confluent myocardial cell cultures exposed to different oxygen tensions . The results obtained indicate that the rate of cellular uptake and accumulation of the inert aminoacid increase with time as the fraction of oxygen is reduced . When alpha-aminoisobutyrate was added in presence of all other aminoacids of the medium, the effect of oxygen was also evident, suggesting a mechanism which overcomes the competitive action of the other aminoacids assigned to the same transport system of alpha-aminoisobutyrate (A system) . The modulation of aminoacid transport activity may represent one of the possible mechanisms by which environmental oxygen affect the rate of cellular protein synthesis. S Afr Med J, 1979 Mar 3, 55(9), 340 - 1 A new method for producing virus plaques in cell cultures; Whitcutt JM; Human oesophageal carcinoma cells can be grown on one side of a microporous gelatin membrane and fed from the other side . When they are infected with human herpesvirus type I at high dilutions, they produce plaques of virus-infected cells which can be detected by ordinary staining methods . This procedure may be suitable for the determination of the numbers of infectious particles in preparations of other viruses which are difficult to assay by conventional plaque assay techniques. Neurosci Lett, 1979 Mar, 11(3), 275 - 8 The lipid composition of rat brain aggregating cell cultures during development; Bourre JM et al.; The lipid and fatty acid composition of rat brain was studied during its development both in vivo and in an aggregating cell culture system . Although the amount of lipid present in the cultures was very low, the increase in glycolipid content corresponded closely to the period of intense myelin formation . Very long chain fatty acids (hydroxylated and unsubstituted) were present in 41-day cultures . In comparison to the in vivo situation, myelination was delayed in vitro and, after 40 days in culture, cholesterol esters were 5-fold higher than in vivo, indicating that demyelination was occurring. Asian J Infect Dis, 1979 Mar, 3(1), 19 - 26 Some characteristics of persistent rabies virus infection in cell cultures; Suzuki M et al.; Fixed rabies virus strain M512 was shown to propagate in BHK cell cultures without interfering with cell growth . Virus specific antigen was detected in the cytoplasm of cells by immunofluorescence technique . A small amount of virus was detected in the supernatant fluid throughout a series of subcultures . The infectivity of the intracellular virus was not affected by the addition of antirabies serum in culture fluid through the extracellular spread of virus was inhibited at the 40th transfer of the infected BHK Cells suggesting the establishment of the persistent M512 infection . Ninety five percent or more cells after cloning from persistently infected cells possessed viral antigen . Based on cytopathic effect, BHK-M512 cells were resistant to superinfection with the homologous virus but were susceptible to the heterologous virus . Interferon was not detected in BHK-M512 cell cultures . The serially passaged BHK-M512 virus gradually decreased the virulence for mice after 40th subculture. J Cell Biol, 1979 Mar, 80(3), 651 - 61 Uptake and release of {3H}gamma-aminobutyric acid by embryonic spinal cord neurons in dissociated cell culture; Farb DH et al.; We have investigated the uptake and release of {3H}gamma-aminobutyric acid (GABA) by embryonic chick spinal cord cells maintained in culture . Cells dissociated from 4- or 7-d-old embryos were studied between 1 and 3 wk after plating . At 3 degrees C, {3H}GABA was accumulated by a high affinity (Km approximately equal to 4 microM) and a low affinity (Km approximately equal to 100 microM) mechanism . The high affinity transport was markedly inhibited in low Na+ media, by ouabain, at 0 degrees C, and by 2,4-diaminobutyric acid . Autoradiography, after incubation in 0.1 microM {3H}GABA, showed that approximately 50% (range = 30-70%) of the multipolar cells were labeled . These cells were neurons rather than glia; action potentials and/or synaptic potentials were recorded in cells subsequently found to be labeled . Non-neuronal, fibroblast-like cells and co-cultured myotubes were not labeled under the same conditions . The fact that not all of the neurons were labeled is consistent with the suggestion, based on studies of intact adult tissue, that high affinity transport of {3H}GABA may be unique to neurons that use GABA as a neurotransmitter . Our finding that none of fifteen physiologically identified cholinergic neurons, i.e., cells that innervated nearby myotubes, were heavily labeled after incubation in 0.1 microM {3H}GABA is significant in this regard . The newly taken up {3H}GABA was not metabolized in the short run . It was stored in a form that could be released when the neurons were depolarized in a high K+ (100 mM) medium . As expected for a neurotransmitter, the K+-evoked release was reversibly inhibited by reducing the extracellular Ca++/Mg++ ratio. Am J Hum Genet, 1979 Mar, 31(2), 149 - 55 Chromosomal mosaicism in amniotic fluid cell cultures; Peakman DC et al.; Over the past 6 years, using in situ processing methods, we have identified 32 cases of mosaicism in amniotic fluid cell cultures prepared from 1,100 samples . Two of these (45,X/46,XX and 46,XX/47,XX, + 21) were called true mosaics because multiple colonies demonstrated the same abnormal chromosome complement, and on subsequent evaluation of the newborn blood or fetal tissues, mosaicism was confirmed . Of the remaining cases, 29 were designated as pseudomosaics because only single or partial colonies exhibited an aberrant chromosome complement, 12 having a trisomy 2 line . In the final case, a double trisomy was demonstrated in only one of eight colonies in the first culture, but in the culture from a repeat sample an additional two colonies showed the same double trisomy . Since no abnormal cells were observed in infant blood, it was postulated that the mosaicism may only have been present in the extraembryonic tissues . It is our conviction that the use of these cloning methods should diminish the danger of misdiagnosis in genetic amniocentesis. Vopr Med Khim, 1979 Mar-Apr, 25(2), 214 - 8 {Activity of glycosidases in amniotic fluid cell cultures}; Tsvetkova IV et al.; Deficiency of glycosidases is a fundamental feature of the hereditary diseases of glycoconjugate accumulation . The data obtained on activity of glycosidases in cell culture of normal amnionic fluid might be used as standards in prenatal diagnostics of hereditary glycolipidoses and glycoproteinoses . Use of cell culture of amnionic fluid for prenatal diagnosis of Tay-Sachs disease is described. J Cell Physiol, 1979 Mar, 98(3), 613 - 8 Induction of human choriogonadotropin and follitropin in HeLa cell cultures by hyperosmolality; Fallon RJ et al.; The growth of cervical carcinoma cell (HeLa) cultures in a hyperosmolar environment stimulates increased production of the onco-developmental peptides human choriogonadotropin (hCG) and follitropin (FSH) . This effect was observed in two sublines examined in this study, HeLa65 and HeLa71 . hCG and FSH were measured by radioimmunoassay using antiserum against the beta-subunit of the hormone dimer, thus insuring immunochemical specificity, The amounts of hCG and FSH produced by HeLa65 and HeLa71 cells cultured in hyperosmolar medium were 2- to 50-fold higher than corresponding hormone levels in basal cultures . Synthesis of gonadotropins depended on concentration and duration of exposure to hyperosmolar medium . Levels of culture medium osmolality effective in inducing hormone production also inhibit the incorporation of 14C-thymidine into acid-insoluble macromolecules . Hyperosmolality thus stimulates the ectopic production of gonadotropic hormones while retarding cellular growth and nucleic acid synthesis. J Biomed Mater Res, 1979 Mar, 13(2), 207 - 16 In vitro evaluation of hemolytic and cell culture toxicity potential of residual ethylene oxide in selected medical materials; Jones AB; The hemolytic potential of pure ethylene oxide in solution was evaluated as a function of initial ethylene oxide concentration in three test systems, diluted whole blood in isotonic saline, erythrocytes washed and resuspended in isotonic saline, and erythrocytes washed and resuspended in isotonic phosphate buffer . Concentrations of 2 mg/ml (2000 ppm) were necessary before cell lysis was observed in either of the isotonic saline systems . This value increased to 10 mg/ml 10,000 ppm) in the isotonic buffer system . Efforts have been made to correlate the hemolysis and cell culture toxicity of residual ethylene oxide in five medical materials to the toxicity of pure ethylene oxide . Only materials exhibiting a low order of inherent toxicity showed any correlation . In poly(vinyl chloride) tubing containing 1.8 and 2.1 mg ethylene oxide per gram of material, a small amount of toxicity was seen in the cell culture system but toxicity was absent in the hemolysis test. Cancer Res, 1979 Mar, 39(3), 1026 - 34 A survey of growth in soft agar and cell surface properties as markers for transformation in adult rat liver epithelial-like cell cultures; San RH et al.; Continuous epithelial-like cell lines derived from normal adult rat liver and hepatocarcinomas were evaluated for their growth in soft agar and five properties of the cell membrane as markers for neoplastic transformation . A correlation of these properties was made to the tumorigenicity of the lines in nude mice . Growth in soft agar was a specific and sensitive marker, whereas the data on uptake of 2-deoxy-D-glucose were consistent, with high uptake being a specific but clearly not a sensitive marker . Agglutination and hemadsorption mediated by concanavalin A, multinucleation in the presence of cytochalasin B, and the cell membrane activity of adenosine triphosphatase did not correlate with tumorigenicity of the other markers for transformation . In addition, it is shown that Mycoplasma infection does not alter any of these properties but that infection can be eliminated by passage of cells through nude mice. Cancer Res, 1979 Mar, 39(3), 1020 - 5 N,N-dimethylformamide-induced alteration of cell culture characteristics and loss of tumorigenicity in cultured human colon carcinoma cells; Dexter DL et al.; Human colon carcinoma cell lines established in this laboratory were treated in vitro with N,N-dimethylformamide . This polar solvent caused morphological changes in the cells as well as alterations in their growth properties . Untreated cells had cloning efficiencies of up to 77% in soft agar; treatment with N,N-dimethylformamide resulted in a complete loss of clonogenicity in semisolid medium . Growth in the presence of the polar solvent also effected a marked reduction in the tumorigenicity of the cells . Ten of ten nude mice that received a s.c . inoculum of 1 X 10(6) untreated cells developed tumors histologically similar to colonic adenocarcinomas in 10 to 14 days, whereas nine of ten nude mice inoculated with 1 X 10(6) treated cells have shown no sign of tumor 3 to 6 months postinjection . Removal of the polar solvent from the culture medium was accompanied by the reappearance of tumorigenicity and the original cell culture characteristics . Therefore, it appears that N,N-dimethylformamide can reversibly effect the reversion of cultured human colon carcinoma cells to less malignant cell types. Clin Genet, 1979 Mar, 15(3), 215 - 20 Amniotic fluid cell culture II . Evaluation of a red blood cell lysis procedure for culture of cells from blood-contaminated amniotic fluid; Felix JS et al.; Second trimester amniotic fluid samples obtained transabdominally for genetic analysis not infrequently are contaminated with blood . There has been disagreement as to whether blood contamination interferes with the efficiency of culture of amniotic fluid cells for genetic diagnosis . A procedure using ammonium chloride to lyse contaminating red blood cells has been recommended to increase culture success . In this report we document that cultures derived from blood-contaminated amniotic fluids form fewer cell colonies than cultures from clear amniotic fluids . We also show that a recommended procedure using ammonium chloride to lyse red blood cells is ineffectual in improving the efficiency of cell culture, and may be detrimental to successful culturing of cells from bloody amniotic fluids . A hypothesis concerning the mechanism of interference with culture of amniotic fluid cells by contaminating blood is presented and a means of preventing this complication is suggested. Proc Natl Acad Sci U S A, 1979 Mar, 76(3), 1318 - 22 Intact microtubules are required for rapid turnover of carboxyl-terminal tyrosine of alpha-tubulin in cell cultures; Thompson WC et al.; In cultured muscle cells the carboxyl-terminal tyrosine of alpha-tubulin was shown to exchange rapidly with free tyrosine . The rapid turnover of this residue was dependent upon the presence of intact microtubules . Half-life determinations were made by two methods: (i) the cells were pulse-labeled in hypertonic medium, in which the major tyrosine incorporation was post-translational, and then chased with isotonic medium; and (ii) the cells were pulsed and chased in isotonic medium, and the post-translational component of the radioactivity of purified alpha-tubulin was calculated . Both methods yielded a half-life of 37 min or less for the terminal tyrosine residue, whereas the half-life of tubulin itself was shown to be greater than 48 hr. Cancer, 1979 Mar, 43(3), 969 - 79 Cytotoxic drugs and the human adrenal cortex: a cell culture study; Morgan MW et al.; Primary monolayer cultures of nonproliferating adult human adrenocortical cells have been used to screen 18 cytotoxic drugs used in cancer chemotherapy for direct effects on corticosteroidogenesis . None of the drugs tested, with the exception of 5-fluorouracil (5-FU) and its metabolite 5-fluorodeoxyuridine, showed significant activity at levels compatible with cortical cell viability and/or likely to be encountered during therapy . These two antimetabolites, however, resulted in a slow but long-lived reversible suppression of corticosteroidogenesis in both ACTH- and monobutyryl cyclic AMP-stimulated, as well as unstimulated cultures of human cells . Thus 10 micrograms/ml resulted in less than 80% inhibition after seven days treatment without any evidence of overt cytotoxicity . High-pressure liquid chromatography showed a suppression of all UV-absorbing steroids secreted . Examination of the ultrastructure of the treated cells showed significant changes in mitochondrial morphology, suggesting a possible site of action for the antisteroidogenic effects of 5-fluorouracil . These in vitro results suggest the possibility of adrenal suppression in vivo during long-term or high dose infusion 5-FU chemotherapy. J Gen Virol, 1979 Mar, 42(3), 443 - 56 Late transcription and simultaneous replication of simian adenovirus 7 DNA as revealed by spreading lytically infected cell cultures; Matsuguchi M et al.; Miller's technique of spreading DNA was applied to monkey cells productively infected with simian adenovirus 7 . This permitted the visualization of cellular DNA transcription, both nucleolar and non-nucleolar, and of late transcription and replication of virus . Virus double-stranded DNA, thin fibres with very few nucleosome-like particles, were observed carrying either transcription or replication complexes . In addition, both RNP transcripts and replication forks were found on some virus duplex DNA . Virus single-stranded DNA replicative intermediates were identified on the basis of their increased thickness and contrast which results from the presence of a DNA binding protein. Vopr Virusol, 1979 Mar-Apr, (2), 137 - 42 {Comparative analysis of the morphogenesis of the Getah virus in cell cultures of vertebrates and mosquitoes}; Lisak VM et al.; Reproduction of Getah virus (the genus Alphavirus) in piglet kidney (PK) and A . aegypti mosquito cell cultures was studied morphologically . Inoculation of PK cells resulted in the development of a lytic infection . Virus morphogenesis in these cells showed the features known for other alphaviruses . In mosquito cell cultures persistent infection developed which was not accompanied by any marked changes in morphology or proliferative activity of the culture . All the morphological and cytochemical data indicate that a certain role in the establishment and maintenance of virus persistence in A . aegypti cell culture may be played by exo- and endophagocytic processes owing to which a peculiar "self-purification" of the cells from the virus and its components occurs . Incubation of the persistently infected culture of mosquito cells at a suboptimal temperature resulted in a marked reduction in the number of newly formed virions which sharply increased with the shift up to the optimal temperature . The experimental results give some insights into certain aspects of alphavirus ecology. J Cancer Res Clin Oncol, 1979 Feb 19, 93(2), 165 - 72 Karyotypic variations in human meningioma cell cultures under different in vitro conditions; Zankl H et al.; Examined were how changes of the culture medium, cultivating procedure and cultivating time will influence numerical representation of different karyotypes in a total of 27 cell cultures of meningiomas with two or more cytogenetically distinguishable cell lines . It could be shown that in medium I (80% Mc Coy 5 A, 20% fetal calf serum) more cell lines with a higher degree of hypodipoidy occurred than in medium II (50% TC 199, 40% bovine amniotic fluid, 10% calf serum) . The number of cells with normal karyotype was higher in cultures which were grown from trypsinized biopsy material in stationary flasks when compared to particle cultures in roller tubes . Cells with a normal karyotype also increased after 1--6 subcultures . By demonstration of SV 40 tumor antigen it could be shown in two cultures that these normal mitoses derived from tumoral and not from stromal tissue. Brain Res, 1979 Feb 16, 162(1), 89 - 101 Neurotransmitter synthesis, storage and release by aggregating cell cultures of rat brain; Honegger P et al.; Rotation-mediated aggregating cell cultures of mechanically dissociated fetal (15-16 days gestation) rat brains between 25 and 35 days in vitro were examined for their ability to synthesize neurotransmitters and putative neurotransmitters from radioactively labeled precursors added to the culture medium . Cultures derived from whole brain synthesized {3H}acetylcholine from {3H}choline, {3H}gamma-aminobutyric acid from L-{3H}glutamic acid, {3H}dopamine from L-{3H}tyrosine, {3H}dopamine and {3H}norepinephrine from L-{3H}dihydroxyphenylalanine, and {3H}serotonin from L-{3H}tryptophan . Veratridine increased and tetrodotoxin decreased the rate of {3H}-dopamine synthesized by aggregates derived from midbrain plus hindbrain . In chase experiments in which aggregates were incubated for 4 h with radioactively labeled precursors and then for 4 h with non-radioactively labeled precursors, addition of veratridine (50 micronM) during the second 4 h incubation significantly decreased the amounts of radioactively labeled acetylcholine, L-glutamic acid, dopamine and serotonin recovered from aggregates . Tetrodotoxin (5 micronM) present during the chase significantly increased the amounts of {3H}acetylcholine and {3H}dopamine recovered from the aggregates . In addition, reserpine (4 micronM) markedly depleted {3H}dopamine from aggregates in these experiments . These results indicate that these cultured cells synthesized neurotransmitters and in addition suggest that some of these compounds are stored by and released from electrically active cells within the aggregates. Cancer Res, 1979 Feb, 39(2 Pt 1), 487 - 91 Dihydrofolate reductase in primary brain tumors, cell cultures of central nervous system origin, and normal brain during fetal and neonatal growth; Duch DS et al.; Dihydrofolate reductase (DHFR) was measured during the development in rats of brain tumors induced following inoculation with avian sarcoma virus . Increasing activity of this enzyme in brain was correlated with the course of primary brain tumor growth . The specific activities of DHFR in primary human brain tumor tissues were comparable to those found in avian sarcoma virus-induced brain tumors in rats . Specific activities of DHFR in cell cultures derived from human and rat primary intracranial gliomas and sarcomas were up to 6 times those found in adult rat liver . The presence of DHFR in neoplasms of central nervous system origin is relevant to the development of folate antagonists which, unlike methotrexate, can readily cross the blood-brain barrier . In normal developing rat brain, DHFR specific activity was high in embryos at 19 days of gestation and declined thereafter, until at 20 days after birth the activity was very low . The methotrexate titration assay was used to measure enzyme levels in the brains of fetal and newborn rats, and good correlation with the spectrophotometric assay was observed . The pattern was different in liver, showing maximum activity 11 days after birth and retaining high activity in adult liver . Both the cofactor requirement and the sensitivity to methotrexate indicate that the enzyme in the brain is DHFR. In Vitro, 1979 Feb, 15(2), 142 - 7 Differentiation in human amniotic fluid cell cultures: chorionic gonadotropin production; Priest RE et al.; Two of the distinguishable cell classes subcultured from human amniotic fluid were examined for their capability to produce human chorionic gonadotropin (hCG) as determined by radioimmunoassay . The class that predominates in most cultures used for prenatal genetic diagnosis, previously termed AF (for amniotic fluid), secretes hCG into the culture medium . Dermal fibroblasts do not, nor does another type of cultured cell from amniotic fluid, previously termed F because of a resemblance to fibroblasts . Primary AF cultures produce more hCG than do subcultures . Evidence that this hormone is intact hCG is provided by its immunoreactivity with antisera raised against the beta-subunit and against the intact molecule of hCG . Furthermore, a dose-response curve for hormone in culture medium is parallel to that of highly purified intact hCG . It is postulated that AF cultures are derived from fetal membranes and retain properties of trophoblast. Pediatrics, 1979 Feb, 63(2), 219 - 21 Vaccination of children with human cell culture rabies vaccine; Plotkin SA et al.; Three children exposed to the bites of proved or probably rabid animals were immunized with human rabies immune globulin and human diploid cell culture vaccine . There were no significant clinical reactions, and all three developed high levels of rabies antibody . The patients have remained well from four to 18 months. Br J Cancer, 1979 Feb, 39(2), 143 - 51 Establishment and characterization of primary human pancreatic carcinoma in continuous cell culture and in nude mice; Grant AG et al.; Primary human panceratic exocrine adenocarcinoma has been established in tissue culture and as xenografts in immune-deficient nu/nu mice . The cell line has a doubling time of 36 h and grows as a confluent monolayer together with a constant population of free-floating cells . Evidence of tumourigenicity was provided by growth on an early diploid fibroblast monolayer and in soft agar, and as solid tumours in immune-deficient nu/mu mice . Chromosome analysis of the cultured cells confirmed their tumour origin . Xenografts established from the cell line or directly from primary tumour tissue have retained a similar histology to the original tumour on serial transplantation . An electrophoretic study of exportable pancreatic digestive enzymes and a number of intracellular enzymes has shown that the cell line and xenografts maintain a human intracellular enzyme profile, but do not produce pancreatic digestive enzymes. Chem Biol Interact, 1979 Feb, 24(2), 177 - 88 Fate of juvenile hormone in mammalian cell culture; Repetto Y et al.; The metabolism of juvenile hormone (JH) I has been examined in fetal mouse liver cells maintained in culture . Diffusion of the hormone into the cells appears to be passive . The hormone is metabolized essentially to organic-soluble metabolites (diol ester, diol acid and acid) by the action of epoxide hydrase and carboxylesterases . Conjugative reactions play a minor role, less than 3% of the hormone being excreted as conjugates (glucuronides, sulfates and mercapturic acid) . About 0.8% of the cellular radioactivity is bound to macromolecules, mainly those of nuclear and mitochondrial origin . Metyrapone and SKF 525-A inhibit covalent binding of the hormone to cytoplasmic macromolecules, which suggests participation of the cytochrome P-450 system in covalent binding of the hormone. Ann Neurol, 1979 Feb, 5(2), 107 - 10 Stimulatory effects of drugs for protein synthesis on muscle cell cultures in Duchenne dystrophy; Ionasescu V et al.; The influence of the membrane-stabilizing agents diphenylhydantoin (DPH) and orgotein (a drug with superoxide dismutase activity) on protein synthesis was studied in cultured human muscle cells obtained from 7 patients with Duchenne muscular dystrophy (DMD) and 14 controls . The cultures were obtained by dissociation and subsequent plating of cells from biopsied quadriceps muscle . These cultures were then labeled with tritiated leucine in the presence and absence of the membrane-stabilizing drugs . Total protein synthesis (cpm/mg noncollagen protein) in first-passage muscle cell cultures from DMD patients showed a 35% decrease, but myosin synthesis revealed normal values . DPH and orgotein increased total protein synthesis by 35 and 50%, respectively, in dystrophic cultured cells, but only by 7 and 8%, respectively, in control cultured cells. J Cell Physiol, 1979 Feb, 98(2), 377 - 93 Electrophysiological properties of human oviduct smooth muscle cells in dissociated cell culture; Sinback CN et al.; Intracellular recordings were made from human oviduct smooth muscle maintained in cell culture . Solitary cells isolated from one another and cells in contact with one another retained electrical properties of smooth muscle in vivo . Membrane potential of solitary cells and connected cells was -35 mV . Connected cells formed electrotonic junctions which transmitted current from one cell to another . This current spread was responsible for differences in input resistance and time constant in solitary cells, 66 Momega and 96 msec, compared to connected cells, 26 Momega and 56 msec . All cells expressed delayed rectification to depolarizing current pulses . Some cells generated action potentials spontaneously or in response to intracellular current pulses . Action potentials were abolished by cobalt or by EGTA . Slow wave potentials, 5 . 20 mV in amplitude, occurred continuously once every 15 to 45 seconds in connected cells. Neurochem Res, 1979 Feb, 4(1), 83 - 97 Development and mechanism of barbiturate tolerance in glial cell cultures; Roth-Schechter BF et al.; The effects of exposure of glial cells in primary culture and in continuous line (clone NN) to pentobarbital over various periods of time on cellular respiration and activities of enzymes involved in carbohydrate metabolism were studied . The results obtained in glial cells in primary culture were qualitatively identical to those obtained in glial cells in clonal line (NN) . Both types of glial cells were shown to develop biochemical tolerance to pentobarbital as defined by an attenuated response to the depressant effects of a challenging dose of pentobarbital on cellular respiration in barbiturate-cultivated cells compared to those grown in drug-free medium . The biochemical tolerance was evident in the presence of glucose and succinate but not malate as substrate . This tolerance to pentobarbital was accompanied by increased activities of hexokinase, glucose-6-phosphate dehydrogenase, succinate dehydrogenase, and glutamate dehydrogenase and by a marked increase in the number of glial cell mitochondria as observed in electron micrographs . The results are interpreted to indicate a compensation of glial cells to the continuous presence of PB by an accelerated glucose uptake and metabolism, an accelerated metabolism of succinate, and an increased mitochondrial activity. J Cell Biol, 1979 Feb, 80(2), 248 - 65 Epithelioid cell cultures from rat small intestine . Characterization by morphologic and immunologic criteria; Quaroni A et al.; Rat small intestinal epithelial cell lines have been established in vitro and subcultured serially for periods up to 6 mo . These cells have an epithelioid morphology, grow as monolayers of closely opposed polygonal cells, and during the logarithmic phase of growth have a population doubling time of 19--22 h . Ultrastructural studies revealed the presence of microvilli, tight junctions, an extensive Golgi complex, and the presence of extracellular amorphous material similar in appearance to isolated basement membrane . These cells exhibit a number of features characteristic of normal cells in culture; namely, a normal rat diploid karyotype, strong density inhibition of growth, lack of growth in soft agar, and a low plating efficiency when seeded at low density . They did not produce tumors when injected in syngeneic animals . Immunochemical studies were performed to determine their origin using antisera prepared against rat small intestinal crypt cell plasma membrane, brush border membrane of villus cells and isolated sucrase-isomaltase complex . Antigenic determinants specific for small intestinal epithelial (crypt and villus) cells were demonstrated on the surface of the epithelioid cells, but they lacked immunological determinants specific for differentiated villus cells . An antiserum specifically staining extracellular material surrounding the cells cultured in vitro demonstrated cross-reactivity to basement membrane in rat intestinal frozen sections . It is concluded that the cultured epithelioid cells have features of undifferentiated small intestinal crypt cells. Ann Microbiol (Paris), 1979 Feb-Mar, 130(2), 273 - 6 {Interferon inducing activity of rabies cell culture vaccine in humans}; Atanasiu P et al.; Rabies cell culture vaccines are able to induce circulating interferon in human sera . In 8/15 cases a low peak of interferon appears in the serum about 8 h after the vaccination . The inhibition has been considered as due to interferon because of the resistance to pH 2 and lack of activity on other animal species. Biomedicine, 1979 Feb, 30(1), 52 - 6 Study of some enzymatic activities in human liver cell cultures; Lemonnier F et al.; Some enzymatic activities were studied in long ter cultures of human liver cells : glucose-6-phosphatase, U.D.P . glucuronosyltransferase, phenylalanine 4-hydroxylase and tyrosine aminotransferase . Only weak tyrosine aminotransferase activity has been found in 12 subcultures, and it has not been increased by addition of corticoids . This tyrosine aminotransferase activity has been measured at different passages of the culture . Our results are compared with those found in literature . The different reasons which could explain the absence of liver specific biochemical functions have been discussed. Endocrinol Jpn, 1979 Feb, 26(1), 103 - 9 ACTH release in pituitary cell cultures . Effect of neurogenic peptides and neurotransmitter substances on ACTH release induced by hypothalamic corticotropin releasing factor (CRF); Hashimoto K et al.; The effects of various neurogenic peptides and neurotransmitter substances on the release of ACTH induced by hypothalamic corticotropin releasing factor (HY-CRF) were investigated using monolayer cultured anterior pituitary cells . Test substances were given in combination with 0.05-0.1 hypothalamic extract (HE)/ml, because HE evoked a significant ACTH release and a linear dose response relationship was demonstrated sequentially between 0.0165 HE/ml and 0.5 HE/ml . Relative high doses of lysine-vasopressin showed a slight additive effect on the release of ACTH induced by 0.1 HE/ml . Leu-enkephalin, dopamine, prostaglandin E1 and E2 slightly reduced the release of ACTH induced by HY-CRF, but the inhibitory effect of these substances were not dose-related . Other tested substances including luteinizing hormone releasing hormone, thyrotropin releasing hormone, somatostatin, melanocyte stimulating hormone release inhibiting factor, beta-endorphin, neurotensin, substance P, vasoactive intestinal polypeptide, angiotensin II, norepinephrine, serotonin, acetylcholine, histamine and gamma-amino butyric acid showed neither agonistic nor antagonistic effect on the release of ACTH induced by HY-CRF . These results indicate that the release of ACTH is controlled specifically by HY-CRF and corticosterone, and modified slightly by some other substances such as vasopressin and prostaglandins, and that the effect of most other neurogenic peptides and neurotransmitter substances is negligible or non-physiological at the pituitary level. Brain Res, 1979 Jan 5, 160(1), 117 - 30 Morphological differentiation of mechanically dissociated fetal rat brain in aggregating cell cultures; Trapp BD et al.; Rotation-mediated aggregating cell cultures of mechanically dissociated fetal rat brains (15-16 days) were morphologically characterized at 4, 19, 26 and 40 days in vitro . The dissociated cells coalesced into spherical aggregates which increased in diameter from 340 micrometer at 4 days to 430 micrometer at 40 days . Cells within the aggregates developed from an undifferentiated state at 4 days to a population of morphologically mature neurons, astrocytes and oligodendrocytes (26 days in vitro) before degenerating . Synaptic contacts and myelinated axons appeared as the cells differentiated . Neurons tended to occur in clusters that were located in central regions of the aggregates, whereas astrocytes were more concentrated in the periphery . Synapses and myelinated axons were more abundant in central portions of the aggregates . The amount of myelin formed within the aggregates was less than in organotypic cultures or in vivo . These results show that the morphological differentiation of mechanically dissociated aggregates resembles the development of rat CNS in vitro . The ease with which large amounts of aggregates can be prepared provides an in vitro system which can be analyzed biochemically without the use of micro-methods . This advantage is particularly useful for multidisciplinary investigations in developmental neurobiology. Clin Chim Acta, 1979 Jan 1, 91(1), 47 - 52 Release of hypoxanthine from and enzyme depletion in rat heart cell cultures deprived of oxygen and metabolic substrates; Van der Laarse A et al.; In a monolayer cultures of neonatal rat heart cells deprived of oxygen and metabolic substrates we measured (1) the release of hypoxanthine, a product of ATP catabolism, and (2) enzyme depletion with creatine phosphokinase (CPK) and alpha-hydroxybutyrate dehydrogenase (alpha-HBDH) . Taking samples each hour up to 7 h of anoxia we were able to demonstrate that hypoxanthine release precedes cellular enzyme depletion . The release rate of hypoxanthine is maximal in the second hour of anoxia and the depletion rate of CPK and alpha-HBDH is maximal in the fourth hour . These results suggest that for early diagnosis of damage to heart cells due to deprivation of oxygen and metabolic substrates the measurement of hypoxanthine release is preferred to that of enzyme release. Pol Arch Weter, 1979, 22(1), 71 - 85 {Effect of 5-iodo-2-deoxyuridine (IDU) on Newcastle disease virus replication in cell cultures}; Swiecicka-Grabowska G; In chick embryo fibroblasts and in mouse fibroblasts of established L line, grown in the presence of IDU, the multiplication of Newcastle Disease virus was better and the CPE more distinct than in control cell cultures . In calf kidney cells only the CPE was enhanced . The most pronounced influence of IDU on virus multiplication was found after adding the analogue in maximum tolerated dose to the medium at the moment of cell culture preparation . The growth curve of virus in chick embryo fibroblasts grown in the presence of IDU shows the most distinct influence of this analogue with regard to LaSota strain . Already two days after inoculation with a smaller dose the titer was 2 log higher than in control cultures and the maximum difference of 3 log was found on the 5th day . In reference to Roakin strain the influence of IDU was weaker--maximum difference of 1,2 log on the fifth day after inoculation . Also the difference between the titers of virus in L cells grown in the presence of IDU and in the control ones, inoculated with LaSota strain was greater (about 1,5 lg during 2-8 days) than in the case of Roakin strain . In chick embryos treated with IDU intraallantoically at 24 and 48 hours before the inoculation with LaSota strain (only this was used) the enhancement of virus multiplication was much poorer than in chick embryo fibroblasts. Arch Virol, 1979, 61(1-2), 61 - 8 Properties of rabies virus (MNIIVP-74 strain) adapted to Japanese quail embryo cell culture; Bektemirova MS et al.; The Pasteur strain of fixed rabies virus was adapted to primary cell cultures of Japanese quail embryos and designated as MNIIVP-74 . In the course of adaptation the virus pathogenicity for rabbits by the intracerebral route decreased considerably and the pathogenicity for rabbits and adult white mice by extraneural routes was completely lost . After inoculation of Japanese quail embryo cell cultures, a titer of the virus in the culture fluid at 4 days was 6.25--7.0 lg LD50/ml (by the intracerebral inoculation of adult white mice) . Viral antigen could be detected by immunofluorescence in the cytoplasm of approximately 60 per cent of the cells . Virus multiplication was accompanied by intensive interferon production . In cultures of BHK-21/13S cells the titer of the virus reached was 5.75 lg LD50/ml at 24 hours and about 30 per cent of the cells were affected . The MNIIVP-74 virus showed a high immunogenic activity in rabbits, guinea pigs and mice. Arch Immunol Ther Exp (Warsz), 1979, 27(4), 561 - 9 Production of interferon in human diploid cell cultures . II . Effect of various factors on interferon production in human diploid cell cultures; Sypula A et al.; Interferon was induced in primary human embryonic fibroblast cultures, using the Newcastle disease virus and synthetic polynucleotide poly I : poly C . Kinetics of interferon production were studied in this system, and optimal doses of some chemical factors which enhance interferon production were determined. Cytogenet Cell Genet, 1979, 24(3), 150 - 9 Studies on isolated cloned populations from irradiated human embryonic cell cultures; Lee CL et al.; The recovery of substrains with stable chromosome aberrations from irradiated fibroblast culture are reported . Four human fetal cell strains were exposed to 600 rad of gamma rays at 200 rad/min . The efficiency of recovering viable cloned subpopulations was approximately 87%, and the frequency of clones with abnormal chromosomes was 40/100 colonies . G-band chromosome analyses for 34 abnormal substrains are described . Karyotypes of some of the clones with complex rearrangements are also presented . Analyses of a total of 47 aberrant events in the 34 abnormal substrains revealed at 7:1 and a 9:1 translocation-inversion and translocation-deletion ratios, respectively . Five of the abnormal substrains were continuously cultured; all except one showed signs of sensecence toward the end of 44 +/- 10 doublings . Unusual prolonged proliferation capacity was observed in substrain FFS-1-9 . The significance of this finding is discussed. Dev Biol Stand, 1979, 42, 121 - 6 Communicating vessel systems for mass cell culture of anchorage dependent cells; Skoda R et al.; Simultaneous filling of a number of vessels with identical input dosage is possible through an operation which uses the principle of communicating vessels with or without air pressure equilibration (APE) . Sets of Roux flaska without APE and the NUNC Multitray Unit system with APE are presented . The latter system is used for large scale propagation of human diploid fibroblasts for production of large quantities of interferon. Br J Haematol, 1979 Jan, 41(1), 69 - 76 The effect of desferrioxamine on fibroblasts and collagen formation in cell cultures; Hunt J et al.; Iron is essential for the activity of proline hydroxylase and is an important co-factor in collagen synthesis . Fibroblast cultures exposed to desferrioxamine show impairment of DNA synthesis and reduced collagen formation, as measured by hydroxyproline synthesis and the deposition of hydroxyproline in the cell mat . In patients with transfusional iron overload long-term treatment with desferrioxamine is said to result in the inhibition of hepatic fibrosis . It is suggested that this may be a direct effect on collagen synthesis rather than an effect of reduced iron stores. Vopr Virusol, 1979 Jan-Feb, (1), 58 - 64 {Effect of the tick-borne encephalitis virus on the chromosomes and cell division in different cell cultures}; Gordeeva NI et al.; The mutagenic effect of tick-borne encephalitis virus (the Pan strain) was studied in chick embryo cells, Syrian hamster kidney cells and pig embryo kidney (SPEV) cell cultures showing different sensitivities to this virus . The dynamics of formation and types of chromosome damages were shown to be different in latent, subacute and acute forms of infection . Virus-induced chromosome aberrations appeared in the period of termination of the virus reproduction cycle . Differences in the effect of tick-borne encephalitis virus on the synthesis of nuclear DNA in chick embryo and SPEV cells were demonstrated . The experimental results suggest that a temporary increase of the mitotic activity observed in the inoculated cultures was due both to a delay of cells in one of the stages of the mitotic cycle (chick embryo and SPEV cells) and to a temporary stimulation of DNA synthesis (SPEV cells). J Supramol Struct, 1979, 12(2), 195 - 208 Action of phorbol esters in cell culture: mimicry of transformation, altered differentiation, and effects on cell membranes; Weinstein IB et al.; The carcinogenic process is usually multifactor in its causation and multistep in its evolution . It is likely that entirely different molecular mechanisms underlie the many steps in this process . In contrast to initiating carcinogens, the action of the tumor-promoting phorbol esters does not appear to involve covalent binding to cellular DNA and they are not mutagenic . Recent studies in cell culture have revealed two interesting biologic effects of the phorbol esters and related macrocyclic plant diterpenes . The first is that at nanomolar concentrations they induce several changes that resemble those seen in cells transformed by chemical carcinogens or tumor viruses . These include altered morphology and increased saturation density, altered cell surface fucose-glycopeptides, decrease in the LETS protein, increased transport of deoxyglucose, and increased levels of plasminogen activator and ornithine decarboxylase . In transformed cells exposed to phorbol esters the expression of these features is further accentuated . Phorbol esters do not induce normal cells to grow in agar but they do enhance the growth in agar of certain transformed cells . The second effect of the phorbol esters is inhibition of terminal differentiation . This effect extends to a variety of programs of differentiation and is reversible when the agent is removed . With certain cell culture systems induction of differentiation, rather than inhibition, is observed . Both the transformation mimetic and the differentiation effects are exerted by plant diterpenes that have tumor-promoting activity but not by congeners that lack such activity . The primary target of phorbol esters appears to be the cell membrane . Early membrane-related effects include enhanced uptake of 2-deoxyglucose and other nutrients, altered cell adhesion, induction of arachidonic acid release and prostaglandin synthesis, inhibition of the binding of epidermal growth factor to cell surface receptors, altered lipid metabolism, and modifications in the activities of other cell surface receptors . A model of "two stage" carcinogenesis encompassing the known molecular and cellular effects of initiating carcinogens and tumor promoters is presented . According to this model, initiating carcinogens induce stable alterations in the cellular genome but these are not manifested until tumor promoters modulate programs of gene expression and induce the clonal outgrowth of the initiated cell. Pathol Biol (Paris), 1979 Jan, 27(1), 5 - 12 {Action of erucic and palmitic acids on rat cardiac myoblasts in primary cell culture . An ultrastructural study (author's transl)}; Charbonne F et al.; Primary cultures of beating myocardial cells of neonatal rat are taken in order to observe the ultrastructural modifications caused by certain long chain fatty acids (erucic acid C22 : 1 and palmitic acid C16 : 0) . Reference cultures are established and observed at the same time as the others . The eurcic acid create an intense steatosis, on the opposite palmitic acid does not . On the contrary the transormations of certain cellular organites such as mitochondria, dictyosomes, rough endoplasmic reticulum and ribosomes are observed in both cases. Pathol Biol (Paris), 1979 Jan, 27(1), 13 - 9 Myocardial electrophysiology: intracellular studies on heart cell cultures from newborn rats; Athias P et al.; Electrical properties of cultured newborn rat heart cells are investigated by the use of microelectrophysiological methods . Amplitudes of resting and action potentials appear close to those of in situ heart cells . Elevated spike rate of rise reveals functional fast sodium channels . An inconstant ratio of cells exhibit pacemaker-like activity but no relationship can be established between this automaticity and the tissular origin of the cultured cells . The pulsation rate appears to be linked to the action potential duration and to the pace-maker potential slope . Spontaneous arrhythmias may occur; they are mainly caused by anomalous conduction and (or) erratic pacemaker driving . Thus heart cell cultures may be considered as a precious tool in the field of the cardiac electrophysiologal and physiopathological studies. Genetika, 1979, 15(5), 855 - 61 {Effect of ftorafur and 5-fluorouracil on the chromosomes of human tumor cell cultures}; Sokova OI et al.; The effect of two antitumour drugs, ftorafur (Ft) and 5-fluorouracil (5-FU) on chromosomes of human tumour cells (strain CA-1) was studied in vitro . Since no data on the karyotype of this tumour strain had been published, the chromosome set of the model was investigated at first . Significant quantitative and structural divergence from the normal human male karyotype were observed . Steam line cells contained 47-49 chromosomes, including 9 permanent markers . No Y-chromosome was revealed . Ft and 5-FU hardly injured the chromosomes of CA-1 cells; the level of aberrant metaphases reached 94% . Chromatid deletions and gaps formed the major part of drug-induced cytogenetic abnormalities. Arzneimittelforschung, 1979, 29(1), 124 - 9 {Prolongation of the mitotic life span of diploid human glia cells in a quantitative cell culture system by centrophenoxine (author's transl)}; Rodemann HP et al.; The accumulation of lipofuscin in postmitotic and reversible postmitotic cells of animals and man is an age correlated process . The mechanism of the lipofuscin accumulation and the function of lipofuscin in the aging cell is not fully understood . The accumulation of lipofuscin in vivo and in vitro can be slowed down by the action of centrophenoxine (Helfergin) . Diploid cells are the only reversible postmitotic cells of man that have a genetically determined limited cell division capacity and accumulate lipofuscin in the process of the cellular aging in a quantitative cell culture system in vitro . The treatment of diploid human glia cells with centrophenoxine results in increasing the cell division capacity by 30--40% in vitro . The data demonstrate that the centrophenoxine induced inhibition of lipofuscin accumulation has a positive influence on the cell metabolism and the mitotic division capacity and causes a delay of the cellular aging of the human glia cells in vitro. J Reprod Fertil Suppl, 1979, (26), 47 - 59 Effects of factors from ovarian follicular fluid and Sertoli cell culture medium on in-vivo and in-vitro release of pituitary gonadotrophins in the rat: an evaluation of systems for the assay of inhibin; de Jong FH et al.; Inhibin-like activity is present both in testicular and ovarian fluids . Various methods can be used for the detection of this activity . Indirect methods, using organ weights as an endpoint, lack the specificity required for reliable estimation of inhibin-like activity . With in-vivo bioassay systems, using estimation of circulating concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in intact or gonadectomized, immature or adult, male or female rats, a suppression of FSH concentrations only is usually observed after injection of inhibin-like material . The largest suppression of FSH concentrations can be obtained in short-term gonadectomized adult female or 35-day-old male rats . Addition of inhibin-like activity to cultured pituitary cells specifically suppresses the spontaneous release of FSH from the cells . After stimulation of cultured pituitary cells with LH-releasing hormone (LH-RH), the release of both FSH and LH are suppressed when inhibin-like activity is present . From dialysis experiments it appears that the molecular weight of the inhibin-like material in follicular fluid is greater than 10 000 . However, acid ethanol extracts of this fluid contain a factor with a molecular weight smaller than 10 000, which does not suppress the spontaneous release of FSH from cultured pituitary cells, but diminishes the LH-RH-stimulated release of both LH and FSH . Furthermore, both follicular fluid and Sertoli cell culture medium can stimulate the release of FSH and LH from pituitary cells when these are cultured without addition of fetal calf serum . These results suggest that gonadal fluids contain several non-steroidal factors which can influence the release of gonadotrophins from pituitary cells. Vet Med Nauki, 1979, 16(10), 96 - 102 {Experiments to obtain and test a cell-culture rotavirus-precipitating antigen}; Mitov B; The location of the rotaviral precipitating antigen and the possibility for its production from cattle rotaviral strains adapted on cell cultures of calf kidney were investigated . Highest titer antigen was produced by concentration with ammonium sulfate simultaneously from the maintaining medium and from the cell monolayer . Comparative studies on the antigenic and physico-chemical properties of the cell-cultural and the faeces rotaviral precipitating antigen were made . The identity of both antigens was proven by the immunodiffuse reaction and by their resistance to ether and tripsine . A considerably higher temperature sensitivity was established of the cell-cultural precipitating antigen as compared to that from faeces . The precipitating antigen was used for confirming the presence of antirotaviral antibodies in the serums of cattle, man and sheep. J Supramol Struct, 1979, 12(2), 259 - 72 Regulation of dome formation in differentiated epithelial cell cultures; Lever JE; Rat mammary (Rama 25) and dog kidney (MDCK) epithelial cell cultures formed 'domes' of cells due to fluid accumulation in focal regions between the culture dish and the cell monolayer . Addition of ouabain caused collapse of domes, suggesting that transport functions were required for maintenance of domes . Dome formation in both epithelial cell lines was stimulated by a broad spectrum of known inducers of erythroid differentiation in Fried erythroleukemia cells . Among these inducers were: 1) polar solvents such as dimethyl-sulfoxide, dimethylformamide, and hexamethylene bisacetamide; 2) purines such as hypoxanthine, inosine, and adenosine; 3) low-molecular-weight fatty acids such as n-butyrate; and 4) conditions expected to elevate levels of cyclic AMP . In the latter group were activators of adenylate cyclase such as cholera toxin and prostaglandin E 1; cyclic AMP phosphodiesterase inhibitors such as theophylline and 1-methyl-3-isobutylxanthine; and analogs of cyclic AMP . Induction of domes occurred 15--30 h after addition of inducer to the culture medium . Induction by chemicals was serum-dependent and required protein synthesis but not DNA synthesis . Induced dome formation was reversible after removal of inducer, requiring the continuous presence of inducer . Reversal was also observed after either either removal of serum or addition of inhibitors of protein synthesis . These results suggest that hypothesis that domes arise in these epithelial cultures by a process that is similar to cell differentiation and is influenced by cyclic AMP. Intervirology, 1979, 12(2), 84 - 8 Cytomegalovirus isolations from cell cultures of human adenocarcinomas of the colon; Hashiro GM et al.; Cytomegalovirus was isolated from cell cultures derived from 3 of 16 surgical specimens of adenocarcinomas of the colon . Virus identification was accomplished through electron microscopical, cytochemical, and immunofluorescent procedures. Avian Dis, 1979 Jan-Mar, 23(1), 209 - 18 Growth of infectious bursal disease virus with plaque formation in chick embryo fibroblast cell culture; Cho BR et al.; The WA69 isolant of infectious bursal disease virus (IBDV) induced cytopathic effects and plaque formation in chick embryo fibroblast (CEF) cultures after serial passages in embryonated eggs and then in CEF cultures . The plaque-forming agent was cloned (designated WA69 clone) and identified as IBDV on the basis of serologic response in inoculated birds and its antigenic relationship to othe