Cell cultures

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 other known IBDV isolants . The WA69 clone replicated rapidly in CEF cultures, reaching peak titers at 48 hours postinoculation, and the virus caused only minimal histologic lesions of the bursa when inoculated into 3-week-old chicks from a specific-pathogen-free flock . The growth of IBDV in CEF cultures with plaque formation may provide a simple in vitro system for virological and serological studies of IBDV.

Oncology, 1979, 36(2), 55 - 62
Herpes virus infection as a cofactor in carcinogenesis: supernatants of herpes virus type 1- and type 2-infected cell cultures contain a cell growth-stimulating factor; Reiss-Gutfreund RJ et al.; Some cell cultures synthesize a mitogenic factor (DNASF) following their lytic infection with either HSV-1 or HSV-2 which is shed into the medium . Of six cell lines permissive to HSV infection tested, three produce DNASF (CV1, HF, MCA) and a significantly higher (3H)-TdR incorporation was obtained with indicator cells growing in supernatants of virus-infected cells (SupV+) than in the corresponding supernatants of sham-treated cells (SupV-) . Sometimes the values obtained with SupV+ exceed those obtained with cell controls, which demonstrates that DNASF is not simply a nutritional factor . Other cell lines do not produce DNASF (HeLa, Wistar and probably REF) and SupV+ frequently inhibit cell growth . DNASF is genetically nonspecific and all indicator cells tested were stimulated by supernatants which contain the mitogen, including the nonpermissive DC-3F cells . The quantity of DNASF induced is directly proportional to the number of cells in the culture and its production peaks when the lysis of the cells is complete . It is not accumulated inside the cells.

Morphol Igazsagugyi Orv Sz, 1979 Jan, 19(1), 48 - 53
{Similarities between cultured human fetal glia cells and cell types from gliomas; cell culture studies}; Gazso L et al.; Authors carried out a comparative study of cell-cultures of human fetal brain tissue and gliomas of various histological structures . In 180-days long cultures of fetal brain tissue four types of cells could be distinguished: 1 . large, polygonal cells, 2 . small, round, immature glia-cells, 3 . bipolar spongioblasts, 4 . gliant astrocytes . These types of cells could not be identified with the cell types of adult human brain culture, but similar types of cells were found in cultures prepared of gliomas of different degree of malignancy . There is some evidence to suggest, that among these types of cells the most important are immature glial cells, since they seem to be multipotent and may play a part in the gliogenesis and in the formation of gliomas as well.

Zh Mikrobiol Epidemiol Immunobiol, 1979 Jan, (1), 79 - 83
{Effect of small doses of diphtheria exotoxin on cell cultures}; Sovetova GP et al.; High diphtheria exotoxin concentrations induced irreversible injuries to all the cultures under study (L, HeLa, spcv pzM) . However, its final titres in the mentioned cells differed . HeLa and pzM cells, being highly sensitive, can be recommended for titration of dipheria exotoxin, instead of the expensive guinea pig tests . Low (subtoxic) doses produced cytoproliferative action and caused changes of the cell properties.

Blood Vessels, 1979, 16(1), 35 - 42
Platelet adherence in endothelial cell cultures; Wechezak AR et al.; Platelet adherence in bovine endothelial cultures was studied by scanning and transmission electron microscopy . Following incubation with platelet-rich plasma (PRP), platelet adherence to endothelial cell surfaces was rare as compared to similarly-tested fibroblasts which displayed numerous adherent platelets . When endothelial cells were induced to retract from their substrate by exposure to cold or versene and then incubated with PRP, platelets were observed adhering to endothelial cell processes and to an extracellular microfilamentous network, located beneath the cell . Platelets were attached singly, retained their discoidal shape, and showed no evidence of granule release . In contrast, microfilaments and adherent platelets were conspicuously absent in endothelial cultures which were retracted with trypsin or collagenase and incubated with PRP . These preliminary results suggest that the observed interaction between platelets and the subcellular surface of cultured endothelial cells is specific for an extracellular network of microfilaments produced by the cells.

Z Naturforsch {C}, 1979 Jan-Feb, 34(1-2), 46 - 50
Evidence for the existence of meta and para directing O-methyltransferases in tobacco cell cultures; Tsang YF et al.; The O-methyltransferase of tobacco cell culture was resolved to its meta and para directing forms by chromatography on DEAE-cellulose . Despite similarities in molecular weights and pI values of the two forms, however, evidence from pH optima, SH-group inhibitors, methylation ratios, SDS-acrylamide gels and mixed substrate experiments indicates the existence of two discrete enzymes acting at the meta and para positions of caffeic acid and quercetin, respectively; though the latter enzyme was less substrate specific than its meta counterpart.

Cytobios, 1979, 26(101), 37 - 43
Growth, plaque assay and immunofluorescent studies on Tataguine virus in cell culture; Fagbami AH; The growth characteristics of Tataguine virus were studied in Cercopithecus monkey kidney (Vero); rhesus monkey kidney (LLC-MK2), baby hamster kidney (BHK-21); porcine kidney (PK-15), mouse fibroblasts (L-929) and Aedes albopictus cell monolayers . The virus replicated without producing any cytopathology in Vero, BHK-21 and Aedes albopictus: but not in the other three cell culture systems . Two or three subsequent serial blind passages in those cultures supporting the growth of the virus did not produce any appreciable increase in virus titre . Immunofluorescent staining of inoculated Vero cells demonstrated the presence of Tataguine virus antigen in the cytoplasm of infected cells . Plaques 1--1.5 mm in diameter were produced only in Vero cell culture . In neutralization tests performed on Tataguine virus, immune mouse and hamster sera, higher antibody titres were obtained by plaque reduction than mouse protection tests.

Genetika, 1979, 15(10), 1841 - 6
{Thiophosphamide induction of sister chromatid exchanges at various phases in the cell cycle of a Chinese hamster cell culture}; Chebotarev AN et al.; Influence of three concentrations of thiophosphamide (thioTEPA) on the formation of sister chromatid exchanges (SCE) has been studied at different phases during 2 cell cycles in cultured Chinese hamster cells . It is shown that the frequency of SCE does not differ from the control level under the effect of the mutagen on cells in the G2 phase of the first cell cycle from the moment of harvesting . Thiophosphamide induces the same number of SCE at S, G1 stages of the first cell cycle and G2 of the second one till the moment of harvesting . The number of SCE correlates in a direct proportion with a concentration of thiophosphamide . A scheme of forming SCE is proposed.

Arch Virol, 1979, 59(3), 281 - 4
A novel plaque method for attenuated rubella virus in Vero cell cultures . Brief report; Sato H et al.; Under defined plaquing conditions, three attenuated strains of rubella virus showed different plaque morphology and plaque size when tested in Vero cell cultures . The Cendehill strain of rubella virus formed distinct, ring-shaped plaques, while strains HPV77 and RA27/3 produced clear plaques that could be distinguished by their different size . These distinguishing characteristics remained preserved even after the vaccine strains were passaged five consecutive times in Vero cell cultures.

J Supramol Struct, 1979, 11(2), 269 - 81
Fibronectin associated with the glial component of embryonic brain cell cultures; Kavinsky CJ et al.; In the basic approach to investigations of neuronal--glial interactions during both normal brain development and its pathogenesis, embryonic brain cell populations were fractionated into purified neuronal and glial components . Using separation procedures based on differential adhesion and cytotoxicity, the isolated neuronal and glial phenotypes could be identified by distinct morphological and biochemical characteristics, including the visualization of glial fibrillary acid protein (GFA) within glial cells in immunohistochemical assays with monospecific anti-GFA serum . When unfractionated cerebrum cells dissociated from 10-day chick or 14-day mouse embryos were plated as monolayers and cultured for 1--14 days, monospecific antiserum against fibronectin (LETS glycoprotein) was found to react with many, but not all, of the cells as revealed by indirect immunofluorescence microscopy . The isolated neuronal and glial components of these populations were used to determine whether the appearance of membrane-associated fibronectin was characteristic of one cell type or the other, or both, and if neuronal--glial cell interaction was required for its expression . It was found that the surfaces of glial cells, completely isolated from neurons, showed an intense fluorescent reaction to the anti-fibronectin serum . In contrast, the purified neuronal cultures showed no fluorescence with either the anti-GFA or anti-fibronectin sera . These results demonstrate fibronectin as a cell surface protein associated primarily with glial cells and independent of neuronal--glial cell interaction for its expression . Furthermore, the results indicate that the fibronectin observed on glial cell surfaces in these cultures is produced endogenously and is not due to the preferential binding of fibronectin present in the culture medium . The role of fibronectin as an adhesive molecule in neuronal--glial interactions is discussed.

Arch Virol, 1979, 61(1-2), 13 - 21
Isolation and cell culture propagation of rotaviruses from turkeys and chickens; McNulty MS et al.; Rotaviruses were detected by electron microscopy in the faeces of turkey poults and broiler chickens with diarrhoea . Apparently symptomless infection was also observed in broilers . The avian rotaviruses could not be isolated in cell cultures by conventional techniques, but were adapted to serial growth in chick cell cultures following trypsin treatment of the virus and the cells . Immunofluorescence studies showed that the avian and mammalian rotaviruses are antigenically related . Antibodies to rotavirus were widespread in sera collected from turkeys, chickens and ducks.

Infection, 1979, 7(3), 150 - 3
Optical demonstration of Chlamydiae in cell cultures by means of fluorochrome 33,258 H; Rolly H et al.; Fluorochrome 33,258 H, a bisbenzimidazole, was employed for demonstrating Chlamydiae in cell cultures, and proved to be particularly suitable for illustrating the unique intracellular reproduction processes of these organisms . The staining procedure is simple and permits a selective differentiation of chlamydial inclusions and their developmental processes in the cell . Contrary to other staining methods, all stages of the chlamydial reproduction cycle can be illustrated thus permitting the early demonstration of Chlamydiae in the cell . The procedure is suitable not only in experimental investigations on Chlamydiae but also in clinical diagnostics.

Vopr Onkol, 1979, 25(2), 42 - 4
{Oncornavirus activation and accumulation in cell cultures under the influence of hormones}; Kuznetsov OK et al.; Sex hormones (testosterone, estradiol) and thyroxine would activate irregularly the production of the specific group antigen (GS-antigen) of avian ribodesoxyviruses in the culture of "normal" chick embryonal cells (CEC, phenotype C/O, GS-) . The mentioned hormones as well as hydrocortisone and insulin would not prevent the Rous sarcoma virus (RSV) infecting of CEC, render no essential action on the accumulation of RSV in the infected CEC culture, and failed to activate the formation of mature RSV in virogenic cultures of rat (XC, R--B77) and mice cells (DBA--B77).

Cytogenet Cell Genet, 1979, 23(1-2), 39 - 43
Induction of high frequencies of endoreduplication in mammalian cell cultures with 33258 Hoechst and rubidazone; Kusyk CJ et al.; Cells of the mouse L strain and the Chinese hamster CHO line were treated with 33258 Hoechst, rubidazone, and a combination of these . Recovering cell populations following the drug removal exhibited a high frequency (20--50%) of metaphases with diplochromosomes (endoreduplication), especially in the combination treatment series (up to more than 70% in the L strain) . Such a procedure should be useful in probing the mechanisms of the endoreduplication process.

J Virol, 1979 Jan, 29(1), 51 - 60
Novel antiviral activity found in the media of Sindbis virus-persistently infected mosquito (Aedes albopictus) cell cultures; Riedel B et al.; Aedes albopictus (mosquito) cells persistently infected with Sindbis virus for a period of 6 months release into the medium a low-molecular-weight material capable of specifically reducing the yields of Sindbis virus during the "acute phase" of infection in mosquito cells . The antiviral activity was produced in detectable levels at 3 days after infection, and its concentration in the extracellular medium increased thereafter . The antiviral activity was inactivated by treatment with the enzyme protease K and heat . It was not activated by treatment with antibody prepared against extracts of Sindbis virus-infected BHK-21 cells . The antiviral activity differs from interferon produced by vertebrate cells in that it is virus specific as well as cell specific.

Hum Genet, 1978 Dec 18, 45(2), 199 - 202
Demonstration of replication patterns corresponding to G- and R-type banding of chromosomes after partial synchronization of cell cultures with BrdU or dT surplus; Schempp W et al.; A standard protocol is reported for the highly efficient demonstration of replication patterns corresponding to R-type and G-type banding.

Acta Pathol Microbiol Scand {B}, 1978 Dec, 86B(6), 355 - 9
Persistent infections with "runde" virus in cell cultures and suckling mice; Traavik T; A morphologically intact, persistently infected BHK 21/c13 cell culture was established by serial trypsinization and reseeding of cells infected with approximately one baby mouse LD50/cell . The extracellular virus infectivity dropped more than 3 log10 units from the 1st to the 4th passage, and was then unaltered up to passage 20 . In 2-week-old mice but not in baby mice, a chronic disease with virus persistence up to 150 days was produced after intracerebral infection with moderate virus doses . The humoral immune response of the animals seemed to be adequate by the methods employed . Development of defective interfering virus particles was indicated by the von Magnus phenomenon in BHK 21/c13 cultures infected with serially passed, undiluted virus samples . Intracerebral infection of baby mice with such samples resulted in transient paresis and motion disturbances instead of the usually fatal encephalitis . Specific virus antigens but no infectious virus could be recovered from such animals.

J Natl Cancer Inst, 1978 Dec, 61(6), 1415 - 22
Surface structure of fetal rat brain cells during neoplastic transformation in cell culture; Haugen A et al.; The surface microstructure of fetal rat brain cells undergoing neoplastic transformation in long-term cell culture after a single transplacental pulse of 75 microgram N-ethyl-N-nitrosourea/g body weight to the fetal (18th day of gestation) BD IX rat was investigated by scanning electron microscopy . After about 3 weeks of culture, N-ethyl-N-nitrosourea-pretreated fetal rat brain cells showed focal proliferation of neural cells on an underlayer of flat, epithelioid cells . The neural cells exhibited varying forms of numerous dorsal ruffles and an increased number of other surface microprojections . Between the 40th and the 100th day, nodules of bipolar and multipolar neural cells were observed with a complex surface microstructure including many blebs and ruffles and an increased number of microvilli . After 100-210 days, more rapidly proliferating, morphologically altered cells formed "piled-up" foci, which resulted in a homogeneous population of cells with numerous long microvilli, large ruffles, and blebs over the whole surface . The cells retained the same altered surface structure until tumorigenicity after reimplantation into the syngeneic host was first observed (approximately 273 days) . Surface alterations characteristic of the neoplastic cells were thus observable more than 100 days before the cells became tumorigenic.

J Gen Virol, 1978 Dec, 41(3), 479 - 91
Effect of herpes simplex virus type 1 infection on the cellular DNA polymerase activities of mouse cell cultures; Radsak K; Thymidine kinase-deficient mouse cell cultures infected with herpes simplex virus type 1 exhibited a maximum of virus DNA synthesis around 8 h post-infection as determined by pulse labelling with 3H-thymidine . Cellular DNA synthesis was progressively inhibited, but still appreciable until 8 h post-infection and not completely abolished at any time during the infectious cycle . Phosphonoacetic acid was found to be a potent and selective inhibitor of virus DNA synthesis only when added to infected cultures before the onset of virus DNA synthesis . During the interval of increasing virus DNA synthesis the activity of cellular alpha polymerase decreased rapidly, whereas the beta polymerase activity increased significantly; a slight increase was observed for the gamma polymerase activity . When infected cells were kept in the presence of phosphonoacetic acid following virus adsorption the effect on cellular DNA polymerases was less pronounced.

Arch Dermatol Res, 1978 Dec 1, 263(3), 283 - 95
Mouse epidermal and skin extracts tested for cytostatic activity ("chalones") . Effects on organ and cell cultures; Gradwohl PR; Crude and fractionated epidermal extracts have been shown to decrease the growth and viability of epidermal cells (mouse ear organ cultures) as well as of murine mastocytoma cells, fibroblasts (L cells) and kidney cells (primary cultures) . This cytotoxicity has been demonstrated to be due to the extracts and not to parasitic toxins . Furthermore, extracts prepared from dermis, mammary glands, and liver were likewise cytotoxic . These results do not confirm the presence of tissue-specific growth inhibitors (chalones) which have been claimed by others to be present in epidermal extracts.

Proc Natl Acad Sci U S A, 1978 Dec, 75(12), 6102 - 6
beta-Galactosidase is induced by hormone in Drosophila melanogaster cell cultures; Best-Belpomme M et al.; Drosophila melanogaster cell lines Kc and Ca and clones FC and RF6, cultured in vitro, have no detectable beta-galactosidase (beta-galactoside galactohydrolase, EC 3.2.1.23) activity (as measured by hydrolysis of o-nitrophenyl-beta-D-galoctoside) . Ecdysterone, a hormonal steroid of critical importance in insect physiology, clearly induces beta-galactosidase activity in D . melanogaster cells cultured in vitro . Induction occurs in cell lines or clones known to be sensitive to ecdysterone (K, Ca, and Fc) and does not occur in clones known to be resistant to the hormone (RF6) . Some properties of the hormone-induced beta-galactosidase activity were studied . The Km for o-nitrophenyl galactoside is 0.35 mM and the Ki for lactose is 12 mM (similar to those of Escherichia coli beta-galactosidase); the activity can be recovered after sodium dodecyl sulfate treatment; the enzyme is a tetramer (Mr of the monomer is 64,000).

Mutat Res, 1978 Nov, 52(2), 255 - 64
Induction of 6-thioguanine- and ouabain-resistant mutations in synchronized Syrian hamster cell cultures during different periods of the S phase; Tsutsui T et al.; Cells of a transformed Syrian hamster line, BP6T, were synchronized by a period of growth in low serum with a subsequent blockage of the cells at the G1/S boundary by hydroxyurea . This method provided cells with nearly 100% synchrony, although approximately 20% of the cells were non-cycling . The cells were then treated with 10(-5) M 5-bromodeoxyuridine for 1 of 5 1-h periods during the S phase and subsequently irradiated with near-ultraviolet light for 5 min . The BrdU plus irradiation treatment induced 6-thioguanine- and ouabain-resistant mutants while BrdU alone or irradiation alone was not mutagenic . 6-Thioguanine-resistant mutants were induced only during early S phase by BrdU plus irradiation treatment . Ouabain-resistant mutants, however, were induced in a biphasic pattern, during early S phase and also during late S phase . The induction of ouabain-resistant mutants at two distinct periods of S phase suggests the presence of two loci for the gene(s) of Na+/K+ ATPase.

Res Vet Sci, 1978 Nov, 25(3), 350 - 5
Detection of Border disease antigen in tissues of affected sheep and in cell cultures by immunofluorescence; Terpstra C; An account is presented of the distribution of fluorescence in cryostat sections of tissues from eight lambs with Border disease (BD) . In young lambs fluorescence was observed in almost every organ, indicating a generalised infection with BD virus . Fluorescence was most prominent in the secretory glands of the alimentary and respiratory tracts, the basal cell layers of the epidermis and mucous membranes, and in the medullary rays of the kidneys . Abomasum, pancreas, kidneys, testicles and thyroid were most consistently affected . Although the number of fluorescing tissues decreased with age, viral antigen could still be detected in two sheep of 22 and 52 weeks old . Border disease viral antigen was demonstrated in cell cultures derived from the brain, kidney and testicle of six out of seven lambs despite the presence of neutralising antibody against bovine virus diarrhoea virus in three of them . The presence of the virus in the skin, the vascular walls and the endocrine system is discussed in relation to the aberrant development of fetal hair follicles, periarteritis and growth retardation respectively.

J Clin Pathol, 1978 Nov, 31(11), 1073 - 7
Sensitivity of immunoperoxidase and immunofluorescence staining for detecting chlamydia in conjunctival scrapings and in cell culture; Woodland RM et al.; The sensitivities of Giemsa, immunofluorescence, and immunoperoxidase staining for the detection of Chlamydia psittaci inclusions in conjunctival scrapings and in irradiated McCoy cell monolayers were compared . Conjunctival specimens were obtained from a cat colony in which a trachoma-like disease, feline chlamydial keratoconjunctivitis, was endemic . The two immunochemical techniques were found to be of equal sensitivity and 50% to 100% more sensitive than Giemsa stain . Permanent preparations of immunoperoxidase stained material can be made and can be read using a simple light microscope . These features make the technique more useful than immunofluorescence staining, which gives temporary preparations that must be examined with a specialised fluorescence microscope.

Dtsch Zahnarztl Z, 1978 Nov, 33(11), 777 - 80
{Aging in human gingival fibroblasts in cell culture . A contribution to the understanding of proliferating inflammations}; Mittermayer C et al.; Proliferation of gingival fibroblasts was studied in cell cultures under controlled conditions . Biopsies taken from 12 patients of different ages were analyzed in regard to the length of the generation cycle and the ability to produce subcultures . Cultures from elderly individuals showed progressive, longer generation cycles than cultures from younger patients . The ability of the gingival cultures from elderly patients to produce subcultures is considerably less than those from young individuals . Apparently gingival fibroblasts are subject to aging processes in the patient himself and in the cell population within the cell culture . The growth characteristics differed depending on the location on the gingiva; the interdental papilla grow better cultures than do free and attached gingiva.

Acta Cytol, 1978 Nov-Dec, 22(6), 546 - 9
Circulating mitotic cells in the newborn infant . The preparation of karyotypes without prior cell culture; Clement GM et al.; A method is described which permits the rapid chromosome analysis, without prior culturing, of newborn infants suspected of having chromosomal abnormalities . This was accomplished by the direct preparation of karyotypable slides from in vivo circulating mitotic cells taken from placental cord blood immediately after delivery.

Vopr Virusol, 1978 Nov-Dec, (6), 699 - 703
{Effect of host cells on the course of chronic rabies virus infection in cell cultures}; Andzhaparidze OG et al.; Different patterns of rabies virus infection were observed in BHK-21/13S and HEp-2 cell cultures at late stages of persistent infections . The infection of BHK-21/13S cells was characterized by periodical increases and declines in the portion of the antigen-containing cells (from 100% to less than 1%) and low infectivity titers which did not correspond to fluctuations in the antigen production and occasional resistance to challenge with vesicular stomatitis virus . In contrast, persistently infected HEp-2 cell culture exhibited a more constant course of antigen production which never reached extreme points; the infectivity titers generally correlated with the portion of the antigen-containing cells . Cultivation in the presence of antirabies serum did not "cure" either of the cultures.

J Gen Virol, 1978 Nov, 41(2), 421 - 6
Effect of interferon on transcription and translation of vesicular stomatitis virus in human and simian cell cultures; Thacore HR; The effect of interferons on vesicular stomatitis virus (VSV) primary transcription, amplified RNA synthesis {i.e . the sum of primary transcription RNA replication (leading to { - } RNA) and secondary transcription (leading to { + } RNA) and virus protein synthesis were studied . In a human cell line, both human and simian interferons inhibited the initiation of primary transcription and amplified RNA synthesis . In contrast, in a simian cell line tested similarly, the initiation of these activities was not affected, though they decreased as the infection progressed . Nevertheless, virus protein synthesis was completely inhibited . These results demonstrate that the action of interferon on virus transcription and/or translation may depend more on the host cell than on the particular interferon used.

J Exp Med, 1978 Nov 1, 148(5), 1378 - 87
Recessive dystrophic epidermolysis bullosa . Evidence for increased collagenase as a genetic characteristic in cell culture; Bauer EA et al.; Fibroblast cultures from patients with recessive dystrophic epidermolysis bullosa (RDEB) demonstrated an increased capacity to synthesize and secrete collagenase . This phenotypic trait appeared to distinguish RDEB from other genetically distinct forms of epidermolysis bullosa . The finding of increased collagenase may be a specific manifestation of these cells in that prototypic lysosomal and cytoplasmic enzymes were present in approximately normal concentrations . In addition, this trait persisted through many cell passages, suggesting that the property was genetically determined . The elevated concentrations of immunoreactive collagenase in fibroblast cultures of patients with RDEB reflected those previously observed in vivo (4) and support the concept of a pathogenetic role for the enzyme in the blistering phenomenon . In three of the cell lines, the increase in enzyme protein occurred in association with a structurally defective enzyme . The data suggest that this may be a characteristic of all RDEB cells.

J Clin Invest, 1978 Nov, 62(5), 987 - 92
Activation in vitro of rheumatoid synovial collagenase from cell cultures; Vater CA et al.; Rheumatoid synovial cells dissociated from matrix and adherent to culture dishes released a latent form of collagenase into culture medium . Previous studies have shown that the latent enzyme does not complex with alpha2-macroglobulin and binds to fibrillar substrate . We now show that serum-free culture medium of the synovial cells contains an inhibitor of collagenase as well as latent enzyme; the two were separated on a column of acrylamide/agarose . Latent collagenase (estimated mol wt 45,000-49,000) was transformed by trypsin to active collagenase of approximately equal to mol wt 33,000 . When mixed with inhibitor the active enzyme formed an inactive complex again with approximately equal to mol wt 45,000-49,000 . The inhibitor(s) itself was found in one major peak of mol wt 33,000-35,000 and several minor peaks eluting with lower apparent molecular weight . Mersalyl, an organic mercurial compound, effectively activated latent collagenase producing an active enzyme with approximately equal to mol wt 33,000 . Bacterial collagenase did not activate latent enzyme . We suggest that latent rheumatoid synovial collagenase, as it is harvested from synovial cells in culture, is an enzyme-inhibitor complex.

Zentralbl Bakteriol {B}, 1978 Nov, 167(4), 296 - 305
{Analysis of the biological effect of city smog extract IV . Growth inhibition of kidney cell cultures (cercopithecus aethiops) under the influence of a city smog extract and its polyaromatic fractions (author's transl)}; Seemayer N et al.; The cell growth of exponentially growing kidney cell cultures of Cercopithecus aethiops was determined by estimation of protein content . The effect of city smog extracts and its polyaromatic fractions on cell growth was examined . Based on the benzo(a)pyren-content the crude extract of city smog exerted the strongest inhibition of cell growth, followed by non purified and purified fraction of polyaromates . The inhibition of cell growth was dose dependent . Results indicate, that for cell growth inhibition are of importance concentrations of toxic substances and exposition time.

J Reprod Fertil, 1978 Nov, 54(2), 215 - 20
A stimulatory effect of the fluid from preimplantation rabbit blastocysts upon luteinization of monkey granulosa cell cultures; Channing CP et al.; Blastocyst fluid was aspirated from Day 6 1/2--7 rabbit blastocysts and was added to cultures of granulosa cells obtained from preovulatory follicles of untreated rhesus monkeys or from follicles of monkeys or from follicles of monkeys treated with PMSG . The stimulation of progesterone secretion was measured and equated with that produced by hCG . The hCG-like activity was also measured in a radioreceptor assay using 125I-labelled hCG and porcine granulosa cells . In 8 out of 10 experiments with cultured cells from untreated monkeys, addition of 20% blastocyst fluid from Days 6--9 of culture stimulated progesterone secretion by 2- to 6-fold . Similar findings were obtained in 5 experiments with cultures from PMSG-treated monkeys except that the blastocyst fluid was added from Days 0 to 6 of culture . The granulosa cells in such cultures underwent morphological luteinization . Compared to a standard of purified hCG the blastocyst fluid contained about 0.76--2.5 ng hCG-like activity/ml which was non-dialysable . The radioreceptor assay indicated the presence of 0.5--2.5 ng hCG-like material/ml.

J Histochem Cytochem, 1978 Nov, 26(11), 921 - 33
Rapid hypotonic method for flow cytofluorometry of monolayer cell cultures . Some pitfalls in staining and data analysis; Fried J et al.; The rapid hypotonic staining procedure developed by Krishan for DNA determinations by flow cytofluorometry has been proven accurate for in vivo cell samples and for cell lines growing in suspension culture . We show that the unmodified procedure may produce distorted DNA histograms when used for staining cells growing in monolayer cultures, however . To eliminate these distortions, it was necessary to avoid the use of trypsin by staining the attached cells directly, using a hypotonic fluorochrome solution to which nonionic detergent was added . Two sublines of HeLa S3 cells are shown to exhibit major differences in their staining characteristics . By using our revised staining procedure, the two sublines appear to produce very satisfactory DNA histograms . However, in only one subline does the S phase fraction calculated from the histograms agree with the autoradiographical labeling index . Mitotic cells remain intact under these staining conditions, and the principal observed effect of nonionic detergents in this case is to decrease the coefficient of variation of fluorescence intensity.

Neurochem Res, 1978 Oct, 3(5), 633 - 9
Superoxide dismutase activity in nerve cell culture; Fried R et al.; Superoxide dismutase (EC 1.15.1.1) activity was assayed in preparations obtained from several clonal lines of nerve cell culture, by enzymatic and nonenzymatic assays . The enzyme was found in dialyzed homogenates of washed cells and in partially purified fractions . The enzyme was also found in cells which had been grown in media containing 5-bromodeoxyuridine, where cell differentiation was observed.

J Med Genet, 1978 Oct, 15(5), 346 - 51
The Gardner syndrome: a cell culture study on kindred 109; Danes BS et al.; In vitro studies on skin cultures established from 49 members from Kindred 109, in whom the Gardner syndrome was first delineated, showed that increased in vitro tetraploidy occurred only in those cultures derived from branches with the full expression of the Gardner gene (colorectal polyps with multiple extracolorectal benign tumours) and not in those derived from branches showing only extracolorectal lesions . Increased in vitro tetraploidy appeared to identify only those family members at risk who had, or would ultimately be expected to show, full expression of the Gardner gene including colorectal polyps which become malignant.

Environ Health Perspect, 1978 Oct, 26, 125 - 33
Neuronal cell cultures as toxicologic test systems; Nelson PG; Neuronal cell cultures now represent well-characterized systems with which acute and chronic toxicologic effects of a variety of agents can be evaluated . Extensive synapse formation occurs over a period of days and weeks in these cell cultures and can be assayed semiquantitatively by morphological and electrophysiological means . Detailed morphophysiologic correlations can be made using a technique for injecting an intracellular marker protein, horseradish peroxidase . A variety of neurochemical indices of development, such as transmitter-related enzyme levels, can also be conveniently determined . The developing neuron and its synaptic connections are important objects of investigation since they may be particularly vulnerable to pathogenic materials . Examples of the effects of acute (opiate) and chronic (inhibitory aminoacid) treatments on synaptic function are given.

J Wildl Dis, 1978 Oct, 14(4), 465 - 9
Rapid identification of infectious pancreatic necrosis virus in infected cell cultures by immunoperoxidase techniques; Nicholson BL et al.; Direct and indirect immunoperoxidase (IP) techniques were evaluated for their potential in identifying infectious pancreatic necrosis (IPN) virus . Both techniques were shown to offer a relatively simple, rapid and efficient means for the specific identification of IPN virus in infected cells . The direct IP method resulted in less nonspecific staining; however, the indirect method was clearly specific and utilized commercially available reagents.

J Gen Virol, 1978 Oct, 41(1), 87 - 95
Prostanglandins enhance spread of herpes simplex virus in cell cultures; Harbour DA et al.; Stimuli such as u.v . light or trauma which induce recurrence of herpes simplex may act by affecting virus replication in the skin . Such stimuli release pharmacologically active agents in the skin, including prostaglandins (PGs) such as PGE2 . These agents, and other compounds which alter levels of adenosine cyclic monophosphate (cyclic AMP), were tested for their effect on the replication of herpes simplex virus (HSV) in Vero cells . Prostanglandin E2 (PGE2) and prostaglandin F2alpha both increase the size of HSV plaques; PGE2 also increases the yield of virus inoculated at low m.o.i . Moreover, inhibitors of prostanglandin synthesis decrease plaque size and inhibit the growth of virus inoculated at low m.o.i.; such inhibition can be partially overcome by adding PGE2 . Analysis of the results suggest that prostaglandins can enhance cell-to-cell spread of HSV, but that cyclic AMP is probably not involved in this effect.

Ann Microbiol (Paris), 1978 Oct, 129 B(3), 313 - 37
Morphological and cytochemical study of Chlamydia with EDTA regressive technique and Gautier staining in ultrathin frozen sections of infected cell cultures: a comparison with embedded material; Popov V et al.; The cryo-ultramicrotomy technique was applied to study the ultrastructure of Chlamydia using two strains: one of C . psittaci and one of C . trachomatis . It clearly appeared that in both strains reticulate bodies show a high degree of plasticity, contrasting with the rigid spherical appearance of elementary bodies . Ultrastructural cytochemical study shows DNA fibrils dispersed throughout the cytoplasm in reticulate bodies whereas DNA is condensed in a nucleoid in elementary and intermediate bodies . The EDTA regressive technique reveals ribonucleoproteins in reticulate and elementary bodies of both studied strains.

Cancer Res, 1978 Oct, 38(10), 3432 - 7
Formation of glucuronic acid conjugates of 7,12-dimethylbenz(a)anthracene phenols in 7,12-dimethylbenz(a)anthracene-treated hamster embryo cell cultures; Baird WM et al.; Secondary cultures of hamster embryo cells exposed to 0.5 nmol {G-3H}7,12-dimethylbenz(a)anthracene (DMBA) per ml medium metabolized more than 90% of the DMBA within 48 hr . Samples of medium were extracted with chloroform, methanol, and water . The chloroform phases contained about one-third of the DMBA metabolites; the major chloroform-extractable metabolite was 8,9-dihydro-8,9-dihydroxy-7,12-dimethylbenz(a)anthracene . Beta-glucuronidase treatment of the aqueous methanol-soluble metabolites converted almost one-half of them to chloroform-soluble metabolites, of which more than 80% were identified as phenolic derivatives of DMBA . Similar metabolite profiles were obtained by treating the medium with beta-glucuronidase before chloroform extraction . Separation of the methyl group-hydroxylated derivatives of DMBA from the phenolic derivatives was accomplished by high-pressure liquid chromatography . Small amounts of hydroxymethyl derivatives were detected only in the chloroform-extractable material, whereas DMBA phenols were the major component of the beta-glucuronidase-released mateirla . These results indicate that the major pathway of DMBA metabolism in hamster embryo cells is oxidation of the aromatic rings and not oxidation of the methyl groups.

J Biol Chem, 1978 Sep 25, 253(18), 6529 - 35
Detection and relative quantitation of mRNA for creatine kinase isoenzymes in mRNA from myogenic cell cultures and embryonic chicken tissues; Perriard JC et al.; The presence of mRNA coding for creatine kinase M (Mck) and creatine kinase B (B-CK) in RNA from myogenic and fibrogenic cell cultures, embryonic muscle, and embryonic brain tissue was demonstrated by "in vitro" translation in a heterologous cell-free protein-synthesizing system from rabbit reticulocytes . The products were isolated by sensitive immunochemical methods and their identity with isolated M-CK and B-CK was shown by the following criteria: (a) the in vitro synthesized creatine kinases react with the specific antibody against these antigens; (b) the labeled peptides co-migrate with purified creatine kinase on sodium dodecyl sulfate gels in single bands; (c) the labeled peptides form homo- and heterodimers with isolated enzymatically active creatine kinase, thus behaving like authentic creatine kinases . The assay was shown to be reproducible and gave a linear response with increasing amounts of RNA, allowing relative quantitation of mRNA in polysomal RNA for the creatine kinases M and B . MRNA for M-CK was detected in polusomal RAN and total cellular RNA from myogenic cells . It is also present in polysomal RNA from enbryonic muscle and the fraction binding to oligo(dT)-cellulose . mRNA for B-CK could be found in RNA extracted from young myogenic cultures and the fraction of polysomal embryonic brain RNA binding to oligo(dT)-cellulose.

Science, 1978 Sep 22, 201(4361), 1141 - 2
Enhancement of oncogenesis in C3H/10T1/2 mouse embryo cell cultures by saccharin; Mondal S et al.; Impure and pure samples of saccharin (2 milligrams per milliliter) did not produce oncogenic transformation of C3H/10T1/2, clone 8, mouse embryo fibroblasts . However, after treatment of the cells with a nontransforming initiating dose (0.1 microgram per milliliter) of 3-methylcholanthrene, continuous treatment with either sample of saccharin (100 micrograms per milliliter) led to significant transformation . It is concluded that in this system saccharin is a cocarginogen, probably functioning as a promoting agent that is 1000-fold less active than the tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate.

Clin Chim Acta, 1978 Sep 15, 88(3), 495 - 507
Cell culture studies of Menkes kinky hair disease; Chan WY et al.; The dose response as well as kinetics of uptake and retention of copper and cadmium of normal and Menkes kinky hair disease (MKHD) cultured fibroblasts are described . In basal culture medium, intracellular copper concentration in MKHD fibroblasts was approximately 3 times that of control cultures . The intracellular copper concentration of MKHD cells was significantly higher than that of normal fibroblasts at medium copper concentrations below 20 microgram/ml . Death of MKHD cells occurred at medium copper concentrations between 15 and 20 microgram/ml with an intracellular copper level 3 times that at basal medium . Normal cells died at medium copper concentration above 30 microgram/ml with an intracellular copper concentration 19 times that at basal medium . These observations suggested the existence of a regulatory mechanism for maintenance and control of intracellular copper in normal fibroblasts which is effective at medium copper concentrations below 30 microgram/ml . This system is defective in MKHD fibroblasts . In basal medium MKHD and normal fibroblasts had similar intracellular cadmium concentrations; however, at higher medium cadmium concentrations MKHD cells had increased intracellular cadmium levels . The uptake of both 64Cu and 109Cd was significantly higher in MKHD cells than in normal cells, indicating that the uptake of 64Cu and 109Cd is not impaired in MKHD cells . A higher retention of 64Cu was observed in MKHD cells at both 37 degrees C and 4 degrees C . No obvious trend, however, was observed in the difference of retention of 109Cd between MKHD and normal cells . An impairment of egress of copper in MKHD cells is implicated by these results.

Br J Haematol, 1978 Sep, 40(1), 105 - 9
Ways of expressing results of human bone marrow progenitor cell culture; Parmentier C et al.; In human bone marrow culture studies the number of granulocyte progenitor cells (CFUc) is expressed as the number of colonies per 10(5) incubated, nucleated cells . However, this provides little information on cell proliferation kinetics of granulopoiesis . The ratio of progenitors (CFUc) to end cells (metamyelocytes or granulocytes) is related to the effectiveness of granulopoiesis and this allows an estimate to be made of an amplification factor within the maturing and proliferating compartments . We measured an index equal to the number of CFUc per 10(5) falls when a large number of granulocytes is produced by each progenitor cell . This was observed in many patients with a neutropenia . An estimation of the total number of metamyelocytes is based on the ratio of the number of metamyelocytes to the number of blood granulocytes . This allows an estimate of the total number of CFUcs, which is of clinical interest.

Am J Vet Res, 1978 Sep, 39(9), 1422 - 7
Pathogenicity of equine herpesvirus: in vivo persistence in equine tissue macrophages of herpesviuus type 2 detected in monolayer macrophage cell culture; Dutta SK et al.; Equine macrophages from the mammary glands of a yearling filly and an 18-year-old barren nonlactatind mare formed cell monolayers in continuous cultures . There was absence of viral cytopathic effect (CPE) in early cell culture passages . The cells from the early cell culture passages having no CPE failed to show evidence of virus or viral antigen by electron microscopic and immunofluorescence studies . Foci of CPE first appeared in the monolayer cell cultures from the filly and the mare in the 3rd and the 4th serial passages respectively, and the CPE increased on subsequent serial passages . Equine herpesvirus type 2 (EHV 2) cultures showing CPE . The macrophage monolayer culture established from the mare produced CPE foci more consistently than did the culture from the filly, and they were more numerous . Conversely, the peripheral blood mononuclear cells from the filly on cocultivation with an equine embryo kidney monolayer cell culture produced more EHV 2 CPE foci than did those from the mare . This study indicated that tissue macrophages may be a site for latent and persistent herpesvirus infections in horses.

Science, 1978 Sep 1, 201(4358), 817 - 9
Estrogen-binding sites in endothelial cell cultures; Colburn P et al.; The cytosol extracted from a vascular endothelial cell line binds {3H}estradiol with high affinity and a high degree of specificity . In contrast, in experiments performed with cytosol labeled in the intact cell, progesterone and, to a smaller extent, testosterone gave an apparent inhibition of estradiol binding . These data support the concept that ovarian hormones may influence the role of the endothelium in various physiological and pathophysiological conditions.

In Vitro, 1978 Sep, 14(9), 734 - 9
Endogenous HPRT activity in mycoplasmas isolated from cell cultures; Van Diggelen OP et al.; Five mycoplasma species most frequently isolated from cell cultures were tested for the presence of endogenous hypoxanthine phosphoribosyl-transferase (HPRT) activity . All of the five, cultured in cell-free medium, contained variable but significant levels of HPRT . Two strains of M . hyorhinis exhibited a 13-fold difference in their specific HPRT activity . When infected with any of these mycoplasma species, HPRT-deficient mouse cell mutants rapidly acquired a cell-associated HPRT activity; however, the cells remained sensitive to HAT medium and resistant to 6-thioguanine . On the other hand, normal HPRT-positive cells deliberately infected with the mycoplasmas uniformly became sensitive to HAT medium . The apparent transfer of mycoplasma-specific HPRT activity to HPRT-deficient cells may be used as a sensitive measure of cell infection by these mycoplasma strains . The HPRT activities of mycoplasmas share several common properties so that they can be distinguished easily from the mammalian HPRT isozymes . Compared to the animal cell enzymes, the mycoplasmal HPRT activities are less heat stable, more strongly inhibited by 6-thioguanine, and in general migrate more slowly in electrophoresis at a neutral pH.

Stain Technol, 1978 Sep, 53(5), 273 - 8
Transmission and scanning electron microscope preparations of the same cell culture; Johnson JE Jr; A technique has been developed which allows transmission electron microscopy and scanning electron microscopy to be performed on the same cell culture sample . The technique uses the Costar 3,393 Leighton Tube containing a plastic insert, which does not stick to epoxy, for transmission electron microscopy . A cut piece of the plastic insert can be critical point dried, sputter coated and viewed under high vacuum with the scanning electron microscope.

Int J Radiat Biol Relat Stud Phys Chem Med, 1978 Sep, 34(3), 245 - 52
Interaction of ascorbate with the radioprotective effect of mercaptoethylamin . An exploratory study in mice, whole animals and cell cultures; Forsberg J et al.; The injection of ascrobate together with cysteamine (beta-mercaptoethylamin or MEA) was shown to cause a partial reversion of the radioprotective action of MEA in mice, and simultaneously of the suppressive action of MEA on RNA synthesis in bone marrow cells . In mouse spleen lymphocytes stimulated by concanavalin A in vitro, MEA and ascorbate exhibited a strong antagonism, neutralizing each other's inhibitory action on RNA synthesis . The latter effect failed to appear after chelation of trace metals, and it is indicated that the ability of ascorbate to counteract the effects of MEA on radiosensitivity and metabolism requires the formation of oxidized products, probably monodehydroascorbate, in agreement with previous observations on bacteria.

Int J Radiat Biol Relat Stud Phys Chem Med, 1978 Sep, 34(3), 201 - 12
The r.b.e . of different-energy neutrons as determined by human bone-marrow cell-culture techniques; Boyum A et al.; The effect of X-rays and different-energy neutrons on human bone-marrow cells was studied using two different cell-culture techniques--diffusion chamber (DC) growth and colony formation in vitro (CFU-C) . Based on the survival of proliferative granulocytes in DC on day 13, the D0 value was 80 rad with X-rays, and 117 rad as measured by the CFU-C assay . The D0 values for neutrons depended on the radiation source and the energy level . The r.b.e . values, which dropped with increasing energy levels of mono-energetic neutrons, were (i) 0.44 MeV; DC 3.7, CFU-C 4.1; (ii) 6 MeV; DC 1.8, CFU-C 2.0; (iii) 15 MeV; DC 1.6, CFU-C 1.6; (iv) fission neutrons; DC 2.6, CFU-C 2.4.

Tsitologiia, 1978 Sep, 20(9), 1065 - 9
{Formation of heterosymplasts in human reticular cell cultures}; Khesin IaE et al.; The cell fusion has been studied in human reticular cell cultures J-96 and J-41 treated with the Sendai virus or with polyethylene glycol 1000 and 6000 . The J-96 cells have a high alkaline phosphatase activity, in J-41 cells the enzyme is not detectable . No heterogenous alkaline phosphatase activity was seen in the protoplasm of symplasts 18 hours after virus cell fusion . It has been shown with polyethylene glycol treatment that during the fusion of cells J-96 and J-41 the enzyme activity was spreading over the symplast protoplasm.

Ann Clin Lab Sci, 1978 Sep-Oct, 8(5), 419 - 24
MIF-like activity in non-stimulated and virus infected cell cultures; Brown EW et al.; Macrophage-migration inhibition factor (MIF) is a lymphocyte-derived substance which plays an important role in cell mediated immunity . Soluble factors containing MIF-like activity and produced by non-stimulated and virus-infected non-lymphoid cell cultures have also been reported . In the present study, a MIF-like factor was repeatedly detected in Buffalo green monkey kidney cells infected with mumps and herpes simplex virus type 1 (HSV-1) indicating that this substance is reproducible and can be stimulated by two viruses of widely varying groups . Wistar-38 (WI-38) cell cultures also increased production of this substance in response to mumps but not HSV-1 infection, indicating that the production of this factor is not necessarily induced by all viruses . A factor which stimulated the spread of macrophages was also found to be induced in WI-38 cells by both viruses, suggesting yet another substance produced by non-lymphoid cells in response to viral infection . The ability of non-stimulated WI-38 cells to produce MIF-like activity was also confirmed, and this factor could be further stimulated or opposed by viral infection.

Science, 1978 Sep 1, 201(4358), 821 - 4
Generation of new mouse sarcoma viruses in cell culture; Rapp UR et al.; Endogenous nontumor-producing type C viruses from C3H mice were used to generate rapid, solid tumor-inducing variants in cell culture . The new mouse sarcoma viruses induce undifferentiated sarcomas with a short latency period upon inoculation into newborn NIH Swiss mice . Transforming viruses appear only transiently, at a time when the virus-infected cells show morphologic alterations; both before and after this time, transforming viruses cannot be detected . These results show that variants of endogenous type C virus which contain transforming genes (oncogenes) can arise during spread of the endogenous virus in fibroblast lines in vitro as well as in susceptible tissues in vivo.

Afr J Med Med Sci, 1978 Sep, 7(3), 129 - 36
Metabolic consequences of mycoplasmal contamination of cell cultures; Williams BA et al.; KB cells originally derived from epitheloid carcinoma of the nasopharynx were found to be contaminated with mycoplasma . The contaminated cells showed significantly higher glycolytic (EMP) and respiratory (TCA) rates when compared with non-contaminated or 'cured' cells . The activity of the hexose monophosphate (HMP) shunt, an alternative pathway of glucose metabolism, was shown to be reasonably higher than normal KB cell levels . Treatment involving combination of heat (41 degrees C) and kanamycin (350 microgram/cm3) for 21 hours was found to adequately and selectively inactivate the mycoplasmal population . Following cure, the metabolism of the cells fell well within normal ranges . The treatment showed no deleterious effects on the KB cell population . The possibility and the significance of an independent hexose monophosphate shunt activity in the mycoplasma population in addition to the already established partial TCA and EMP activities, and the overall significance of detection of carbohydrate metabolism in these organisms, are discussed.

Eur J Biochem, 1978 Aug 15, 89(1), 3 - 9
Changes of mitochondrial DNA polymerase-gamma activity in synchronized mouse cell cultures; Radsak K et al.; Following synchronization by a double hydroxyurea block, mouse cell cultures exhibited a period of accelerated precursor incorporation into mitochondrial DNA during the late nuclear S phase . Peak activity of mitochondrial DNA polymerase-gamma occurred concurrent to the interval of accelerated organelle DNA synthesis . Mixing experiments suggested that the variations in mitochondrial DNA polymerase activity during the cell cycle were not due to free inhibitors in the enzyme preparations examined.

Science, 1978 Aug 4, 201(4354), 467 - 9
Enkephalin-containing neurons visualized in spinal cord cell cultures; Neale JH et al.; Neuronal cells, axons, and terminals containing immunoreactive enkephalin have been visualized in cultures of dissociated fetal spinal cord . These cultures may provide a valuable system in which to explore the effects of chronic drug treatment on the physiology of enkephalin-containing cells and their interactions with other cells.

J Protozool, 1978 Aug, 25(3 Pt 2), 388 - 94
Continuous cultivation of Trypanosoma theileri at 37 C in bovine cell culture; McHolland-Raymond LE et al.; Trypanosoma theileri was cultivated at 37 C in bovine bone marrow cell culture through 50 consecutive subcultures . Medium 199, supplemented with Bacto-peptone, vitamin B12, and fetal bovine serum, was utilized both for primary and continuous cultivation . The number of trypanosomes produced in culture averaged 8 x 10(6) (1-26 x 10(6)) trypanosomes/ml . In each subculture the organisms divided as epimastigotes and transformed into trypomastigotes; a round from was observed during the stationary and declining phase of growth . Gradual changes such as increased generation time, size reduction, and decreased trypomastigote production were observed as subculturing progressed . Cultured trypanosomes were infective for the bovine through the 48th serial transfer and could be cultivated at 26 degrees C.

J Gen Virol, 1978 Aug, 40(2), 455 - 8
A semi-continuous system for the production of human interferon in lymphoblastoid cell cultures; De Ley M et al.; The simultaneous occurrence of virus replication and of interferon production in Namalva lymphoblastoid cell cultures infected with measles virus has allowed the development of a semi-continuous production system yielding about 10(4) units of interferon for each 10(6) cells.

In Vitro, 1978 Aug, 14(8), 651 - 62
Normal human endometrium in cell culture . I . Separation and characterization of epithelial and stromal components in vitro; Kirk D et al.; Separation of human endometrium into its epithelial and stromal components has been achieved through collagenase digestion and has permitted a study of these two cell populations under specific experimental culture conditions . The stromal cell populations showed a progesterone response, were easily handled in culture, and displayed a limited in vitro life span typical of human diploid fibroblasts . In contrast, epithelium only survived in short-term primary culture and showed no clear hormone response . High-density epithelial cultures remained viable for longer periods in culture . Comparisons between resurfacing endometrial epithelial cells in vivo and epithelial cells migrating from explants in vitro suggested that this initial epithelial migration in vitro was the counterpart of the repair response in vivo.

Cancer Lett, 1978 Aug, 5(2), 81 - 9
Comparison of the metabolic profiles of benzo{alpha}pyrene obtained from primary cell cultures and subcellular fractions derived from normal and methylcholanthrene-induced rat liver; Schmeltz I et al.; Hepatocyte primary cell (HPC) cultures derived from either (a) non-induced (normal) or (b) methylcholanthrene (MC)-induced rat liver actively metabolized the carcinogen benzol{alpha}pyrene (BaP) over a 24-h period . In both cases, the BaP metabolites generated were qualitatively similar to those seen in the metabolism of BaP by isolated rat liver microsomal fractions; in addition, unidentified compounds were evident in the chromatographic profile generated by the cultured cells . In cells derived from (a), levels of known metabolites (phenols and diols) increased over the time period studied . On the other hand, in cells derived from (b), levels of diols decreased markedly after 8 h . These results suggest that induction with MC enhances both activation and, to a greater extent, conjugative-detoxification pathways of BaP, so that in cells obtained from (b) the formation of water-soluble metabolites is enhanced and levels of organic soluble metabolites are lower than in cells obtained from (a) . Metabolism of BaP in primary cell culture derived from rat liver is thus seen to be similar to in vivo metabolism of the carcinogen, but somewhat in contrast to the in vitro microsomal (subcellular) metabolism of BaP where conjugative-detoxification pathways are virtually inoperative.

J Invest Dermatol, 1978 Aug, 71(2), 157 - 62
Isolation and growth of adult human epidermal keratinocytes in cell culture; Liu SC et al.; Human epidermal keratinocytes may be isolated in high yield from 0.1 mm keratotome sections of adult skin by short-term trypsin release . When plated on a collagen-coated plastic surface or on a collagen gel, keratinocytes attach with high efficiencies (greater than 70%) and form confluent, stratified cultures . Cell populations of predominantly basal cells produce proliferative primary cell cultures while populations of basal cells and malpighian cells result in nonproliferative primary cultures . Both nonproliferative and proliferative primary cultures may be subcultured on collagen gels following dispersion by trypsin and EDTA . Methotrexate strongly inhibits proliferative keratinocytes at low concentrations (0.1 microgram/ml) but has no cytotoxic effect on non-proliferative cells . L-serine and dexamethasone increase the multiplication rate of both primary and subcultured human keratinocytes.

Proc Natl Acad Sci U S A, 1978 Aug, 75(8), 3836 - 40
Neoplastic transformation of rat mammary cells exposed to 7,12-dimethylbenz{alpha}anthracene or N-nitrosomethylurea in cell culture; Richards J et al.; Primary cultures of mammary cells from virgin Lewis rats were seeded at 5 X 10(5) cells per cm2 in medium 199 supplemented with 10% fetal calf serum, insulin (5 microgram/ml), prolactin (5 microgram/ml), estradiol (5 ng/ml), progesterone (0.5 microgram/ml), and hydrocortisone (0.5 microgram/ml) . On the second or third day of culture, cells were exposed to either 7,12-dimethylbenz{alpha}anthracene (0.1 microgram/ml for 24 hr) or N-nitrosomethylurea (80 microgram/ml for 2 hr) . The cells were later assayed for transformation by transplanting 10(6) or 10(5) cells into gland-free mammary fat pads of 3-week-old female hosts . Untreated cells produced only normal mammary outgrowths when transplanted . Cells treated with 7,12-dimethylbenz{alpha}anthracene or N-nitrosomethylurea produced abnormal outgrowths in 11% of the transplants . These abnormal outgrowths ranged from rapidly growing adenocarcinoma to alveolar and ductal hyperplastic lesions . The results indicate that rat mammary epithelial cells can be transformed by exposure to chemical carcinogens in culture and thus represent a potential in vitro model for epithelial cell transformation.

Ann Microbiol (Paris), 1978 Aug-Sep, 129B(2), 245 - 65
{Problems in detection of mycoplasma contamination in cell cultures (author's transl)}; Bonissol C et al.; A total of 135 cell lines was examined for mycoplasma contamination using two techniques: isolation and specific DNA-staining with DAPI or "Hoechst 33258" . The two techniques showed similar results in 64% of the cases of cell contamination while the remainder was detected only by one or the other techniques: 12,82% by the staining technique and 23% by the isolation technique, which shows that the 2 techniques are complementary . The staining technique is very quick, easy to execute, very sensitive, and should be the method of choice to detect contamination when the mycoplasma do not grow in acellular media.

In Vitro, 1978 Aug, 14(8), 675 - 85
Histochemical demonstration of collagen fibers in ascorbic-acid-fed cell cultures; Berman J et al.; Nine cultures of fibroblast cell types and 13 epithelial-like cell types were maintained for 1 week in media supplemented with L-asborbic acid (50 microgram per ml) . All fibroblast-like cultures produced extracellular fibers that stained positively by a silver-impregnation reticulin stain . Nine of the 13 epithelial-like cultures produced fibers that stained positively for reticulin . Nearly all cultures not supplemented with ascorbic acid showed no fiber staining . Those few lines that stained positively for reticulin in the absence of ascorbic-acid supplementation demonstrated only slight reticulin formation . Reticulin from one fibroblast culture and one epithelial culture was examined by electron microscopy, and the silver-impregnated fibrils were morphologically identical to collagen . The reticulin was digestible with collagenase, providing further evidence that the silver-impregnation reticulin stain identifies collagen in culture . The demonstartion of collagen can be performed easily in histology laboratories using Formalin-fixed cells, and provides a means of assaying a functional property of cells in culture which is characteristic of connective tissue fibroblasts in general as well as certain specialized epithelia.

Brain Res, 1978 Jul 28, 151(1), 1 - 17
Electron microscopic autoradiography of the uptake of {3H}GABA in dispersed cell cultures of rat cerebellums . I . The morphology of the GABAergic synapse; Burry RW et al.; Dispersed cell cultures of rat cerebellums 21 days in vitro were incubated in saline containing 0.5 micrometer {3H}GABA for 5 min, fixed and prepared for electron microscopic autoradiography . Quantitative methods for analyzing the resulting autoradiographs were developed to distinguish lightly labeled neurons from heavily labeled (i.e . GABAergic) neurons . After a 3 week exposure, 2% of the presynaptic elements were found to be GABAergic . A longer incubation time of 15 min resulted in a greatly increased grain density over lightly labeled neurons, making it more difficult to distinguish them from the GABAergic neurons . When the concentration of {3H}GABA was increased to 1.0 micrometer, the grain densities over both GABAergic and other neurons increased to a similar extent . The morphology of the GABAergic synapses differed from that of the total population synapses . The GABAergic synapses had larger cross-sectional areas, lower densities of vesicles, greater numbers of vesicles, and thinner postsynaptic densities . Both the GABAergic and total population had similar lengths of the postsynaptic densities, cleft widths, vesicle sizes and types of postsynaptic elements . The morphology of the GABAergic synapse reported here is similar to that described for basket and stellate presynaptic elements in vivo.

Aust Vet J, 1978 Jul, 54(7), 323 - 8
A cell culture vaccine against bovine ephemeral fever; Tzipori S et al.; A vaccine was prepared from cell culture fluids harvested from the twelfth passage of the 919 strain of bovine ephemeral fever (BEF) virus in Vero cell cultures . Cattle were vaccinated subcutaneously with various combinations of strain 919 virus and adjuvants . Neutralising antibodies were assayed at various times after vaccination and some cattle were challenged by intravenous inoculation with the virulent 417WBC strain of BEF virus . Strain 919 virus of the third and twelfth passage levels in Vero cells produced neither fever, clinical illness nor detectable viraemia in 5 calves inoculated intravenously . Nor could viraemia be detected in 5 heifers receiving vaccine subcutaneously . When the vaccine was administered mixed with aluminium hydroxide adjuvant, the production of neutralising antibodies increased with an increase in the volume of vaccine from 2.5 ml to 10 ml and the response to 2 injections was significantly better than the response to a single injection . The neutralising antibody response was decreased when vaccine was diluted in phosphate buffered saline . The neutralising antibody response following 2 subcutaneous vaccinations with strain 919 virus mixed with aluminium hydroxide adjuvant was higher than that following intravenous inoculation with virulent virus . The vaccine-induced antibodies persisted for at least 12 months, and revaccination at this time led to an increase in the titre of neutralising antibody . Antibodies induced by a single subcutaneous administration of strain 919 virus mixed with Freund's complete adjuvant persisted for at least 40 weeks; those induced by vaccine containing Freund's incomplete adjuvant had virtually disappeared within 16 weeks . All these calves responded to vaccination with aluminium hydroxide-containing vaccine with increases in levels of neutralising antibodies . Of 26 vaccinated calves challenged with virulent BEF virus, 24 remained clinically normal . Two developed brief periods of pyrexia on the seventh day after challenge, but no other clinical signs . One of these calves had a viraemia that was demonstrated only by intravenous inoculation of a susceptible calf . The remaining calf had no detectable viraemia . All of 7 unvaccinated calves developed severe clinical BEF within 5 days of challenge . No disease attributable to the 919 virus occurred in 24 vaccinated pregnant heifers or their newborn calves.

Diabetes, 1978 Jul, 27(7), 778 - 81
Virus-induced diabetes mellitus . XI . Replication of coxsackie B3 virus in human pancreatic beta cell cultures; Yoon JW et al.; The capacity of Coxsackie B3 virus to infect insulin-containing beta cells was studied in human pancreatic cell cultures . Antibody to Coxsackie B3 virus was labeled with fluorescein isothiocyanate, and antibody to insulin was labeled with rhodamine . By use of a double-label antibody technique, three populations of cells were identified: uninfected insulin-containing beta cells, which stained only with rhodamine-labeled anti-insulin antibody; Coxsackie-infected (noninsulin-containing) cells, which stained only with fluorescein-labeled anti-Coxsackie antibody; and Coxsackie-infected insulin-containing beta cells, which stained with both antibodies . Radioimmunoassay showed that intracellular immunoreactive insulin decreased rapidly beginning at 24 hours after infection, and the decrease in insulin roughly paralleled the increase in viral titer . It is concluded that, under in vitro conditions, human beta cells are susceptible to Coxsackie B3 virus.

Biomedicine, 1978 Jul, 29(5), 162 - 3
Stimulation of platelet production in vivo by a factor in cell culture conditioned medium; Krizsa F et al.; Injection of medium conditioned by a murine myelomonocytic leukaemic cell-line (WEHI-CM) stimulates platelet production in irradiated, bone marrow reconstituted mice . Media conditioned by the growth of normal bone marrow cells (BM-CM) or by a lymphoid leukaemia cell line had no effect on platelet production . However, the effect of WEHI-CM on platelet production was further enhanced when injected along with BM-CM, indicating that more than one factor may play a role in the regulation of megakaryocytopoiesis.

Shika Rikogaku Zasshi, 1978 Jul, 19(47), 186 - 99
{Cytotoxicity of some dental cements in a cell culture system (author's transl)}; Imanishi Y; Four dental cements of zinc phosphate cement, polycarboxylate cement, zinc oxide-eugenol cement and epoxy resin cement have been tested by means of cell culture method using L strain cell . The cells were cultured with a test piece of the cements in the incubator of 37 degrees C . The test pieces of powder, liquid, un-set cement and set cement were prepared . Cell multiplication, medium pH and zone index in agar diffusion method were measured and also cell morphological changes were observed around the test piece . Test pieces of the four un-set cements showed cytotoxic action at 2 hours administration, although the cytotoxicity of their cements decreased after setting . pH 7.2 of the normal medium was changed to 4.6 with un-set zinc phosphate cement . The other cements affected slightly comparing with zinc phosphate cement . The largest zone index which indicates degree of cytotoxicity, were observed around the test piece of the liquid of zinc phosphate cement . In this study, a biocompatibility of four dental cements was investigated and the following results were obtained . 1 . Zinc phosphate cement showed strong cytotoxic action under the un-set condition, and the cytotoxicity almost disappeared after setting . 2 . Polycarboxylate cement showed weaker cytotoxic action than zinc phosphate cement . However the cytotoxicity did not disappear after setting . 3 . Zinc oxide-eugenol cement showed cytotoxic action which was similar to polycarboxylate cement, but it was slightly stronger than that of polycarboxylate cement . 4 . Epoxy resin cement showed the weakest cytotoxic action than other three cements under the un-set condition . The cytotoxicity of set epoxy resin cement was strong, followed by zinc oxide-eugenol cement.

Steroids, 1978 Jul-Aug, 32(1), 37 - 44
Estrogen synthetase in choriocarcinoma cell culture . Stimulation by dibutyryl cyclic adenosine monophosphate and theophylline; Bellino FL et al.; The stimulation of estrogen biosynthesis by N6,O2'--dibutyryl adenosine 3':5'-cyclic monophosphate and theophylline dbT) in cultures of the JAr line of choriocarcinoma cells was investigated by measuring the specific activity and kinetic constants of estrogen synthetase (aromatase) in the various subcellular fractions after differential centrifugation of homogenized cells in isotonic sucrose . The low speed (900xg) pellet, from cells grown with or without dbT and homogenized in isotonic sucrose, contains the majority of the aromatase activity and the highest aromatase specific activity . The aromatase specific activity in the homogenate of cells grown with dbT and in the various subcellular fractions is 4- to 10-fold higher than in cells grown without dbT . The Vmax of androstenedione (4-androstene-3,17-dione) aromatization in homogenates from dbT-stimulated cells (6.9 pmol estrogen/min per mg protein) is significantly increased over that measured in the absence of dbT (1.5 pmol estrogen/min per mg protein); the Km values, however, are not significantly different (average of 43.8nM in dbT-stimulated fractions; 53.2nM in control fractions) . These results suggest that the increased aromatase specific activity in dbT-stimulated cells results from an increase in amount of active enzyme, rather than from an increase in affinity of the enzyme for its substrate.

Nord Vet Med, 1978 Jul-Aug, 30(7-8), 333 - 6
Fused rocket and rocket immunoelectrophoresis adapted for demonstration and quantitation of the A antigen of Marek's disease virus-infected cell cultures; Singh G et al.; Preliminary results have shown that the rocket immunoelectrophoresis technique can be used as a method for quantitation of the A antigen of Marek's Disease virus-infected cell cultures.

In Vitro, 1978 Jul, 14(7), 631 - 8
Isolation of function human trophoblast cells and their partial characterization in primary cell culture; Stromberg K et al.; Human trophoblast isolation and cell culture procedures were examined to identify variables that enhance secretion of chorionic gonadotropin (HCG) in primary culture . Brief exposure of unminced first-trimester placental specimens to a solution of trypsin-EDTA-DNAse, and isolation of the dispersed cells after Ficoll-hypaque centrifugation yielded primary cultures that were high in HCG secretion and content of epithelial-like cells . The gradual decline in HCG level with time in monolayer culture in these presumptive trophoblast cells was retarded by treatment with theophylline and cyclic adenosine monophosphate . Exposure to methotrexate (MTX) did not increase HCG secretion in normal trophoblast cells, in contrast to a 5-fold stimulation by MTX in the JAR line of choriocarcinoma cells . Clusters of polygonal cells in primary culture progressively lost their capacity to secrete HCG and their epithelial-like morphology . However, they could be maintained as cell strains through approximately 15 passages over a period of 13 to 16 weeks.

J Biomed Mater Res, 1978 Jul, 12(4), 517 - 24
Endothelial cell culture on dacron fabrics of different configurations; Eskin SG et al.; The growth of tissue-cultured aortic endothelial cells from the calf using 12 different configurations of Dacron polyester (U.S . Catheter and Instrument Co.) as substrates was studied . Scanning electron microscopy showed maximum cell coverage on tightly knit configurations, whereas loose knits and velours did not support cell growth.

Brain Res, 1978 Jun 30, 149(2), 279 - 93
Rat cortical neurons in cell culture: culture methods, cell morphology, electrophysiology, and synapse formation; Dichter MA; Rat cortical neurons from 15 day embryos are grown in dissociated cell culture and maintained in vitro for 8--12 weeks . The neurons develop into forms which resemble mature cortical neurons in situ, stain with silver and exhibit passive and active electrophysiological properties similar to those of cortical neurons . Extensive chemical excitatory and inhibitory synapses develop de novo . These cultures can provide a model for future studies of mammalian CNS neuronal physiology, transmitter pharmacology, pathophysiology and mechanisms of drug action.

J Biol Chem, 1978 Jun 10, 253(11), 3877 - 81
A cell culture assay for follicle-stimulating hormone; Beers WH et al.; Cultured rat ovarian granulosa cells respond to follicle-stimulating hormone (FSH) by synthesizing and secreting plasminogen activator . The specificity of the response for FSH prompted us to explore the use of this system as an in vitro bioassay for FSH . The release of FSH by pituitary cell cultures has been examined by this method, as have been preparations of FSH of known biological activity . The results indicate that the granulosa cell system allows accurate, rapid, and convenient determinations of FSH activity . Furthermore, the method obviates metabolic clearance problems associated with whole animal assays and it is extremely sensitive: as little as 10(-15) mol (approximately 100 micronIU) of FSH can be detected.

Can J Microbiol, 1978 Jun, 24(6), 689 - 92
Detection of Mycoplasma hominis and Mycoplasma orale in cell cultures by immunofluorescence; Payment P et al.; Mycoplasma contaminants of animal and human cell cultures were rapidly detected and identified by an indirect immunofluorescent technique . Cells suspected of being contaminated by mycoplasmas were grown as monolayers on chamber slides in a culture medium selected to promote mycoplasmal growth . Before fixation by acetone, the monolayers were subjected to a hypotonic treatment to cause swelling of the mycoplasmas . Detection and identification were then performed by indirect immunofluorescence using rabbit antisera to various mycoplasma species . The correlation between results obtained by the standard isolation procedure and those obtained by this method was very close.

Gann, 1978 Jun, 69(3), 417 - 21
Mixed lymphocyte--tumor cell culture reaction in cancer patients; Ikeda H et al.; To measure immunological reactivity or recognition of tumor antigens, mixed lymphocyte--tumor cell culture reaction (MLTR) was studied using a micromethod . The peripheral lymphocytes of cancer patients were mixed in vitro with autochthonous tumor cells that had been irradiated with 60Co at a dose of 6,000 rad just before use . The lymphocyte blastogenic response was estimated by the incorporation of 3H-thymidine in the acid-insoluble fraction and expressed as counts per minute . The stimulation index equal to or greater than 2.0 was arbitrarily expressed as positive blastogenic response in the present experiment . Positive blastogenic responses to autochthonous tumor cells were observed in 10 of 34 patients with various solid tumors . The intensity of blastogenic response to tumor cells was correlated with that of the non-specific responses to PHA (r=0.4732, P less than 0.01) . These results indicated that non-self tumor-associated antigens, which could induce in vitro blastogenic response of autologous lymphocytes, were present in some part of human tumors.

Rev Can Biol, 1978 Jun, 37(2), 127 - 30
{Relative sensitivity of various cell cultures to the thermostable exotoxin of B . thuringiensis}; Laurent P; The "thermostable" B . thuringiensis exotoxin is active on cell cultures of Mammals "in vitro", except on the KB strain from a human tumor . The primary cultures are the most sensitive: first, with monkey kidney cells, the growth is inhibited by 0.1 mg of toxin per ml; next, the young rabbit kidney cells react to 0.25 mg of toxin per ml . The established lines of cells come last: human diploid cells (Lyon 4) and heteroploid cells (BHK21C13), with the same active dose of 1 mg of toxin per ml . No protection is obtained by adding ATP to monkey kidney cells at the same time as the exotoxin.

Tsitologiia, 1978 Jun, 20(6), 686 - 9
{Pharmacologic analysis of the stimulating effect of serotonin on proliferation in cell cultures}; Gedevanishvili MD et al.; Serotonin (10-7 M) stimulated cell proliferation in the primary cultures of mouse and human embryonic fibroblasts as well as in mouse L-cells and in monkey kidney cells (MA) . The stimulatory effect is completely prevented by pretreatment of cultured cells with serotonin antagonists of tipindole, morphine or cyproheptadine type which do not affect cell proliferation . It is therefore assumed that the stimulatory action of serotonin on these cells is realized via specific serotonin receptors.

J Embryol Exp Morphol, 1978 Jun, 45, 173 - 87
Cell culture of individual Drosophila embryos . II . Culture of X-linked embryonic lethals; Cross DP et al.; Results are reported from the culturing in vitro of cells from individual early gastrulae of the following four groups of X-linked embryonic lethal mutants of Drosophila melanogaster . (1) Notch lethals, Five Notch mutants were studied which have been reported to give similar abnormalities in whole embryos: the nervous system displays a three-fold hypertrophy as part of a shift in the pattern of differentiation within ectodermal derivatives, and mesodermal derivatives do not differentiate . An hypertrophy of nerve was found in cell cultures prepared from embryos of all five mutants . In addition, four of the five alleles consistently gave abnormalities of muscle differentiation: when compared to controls, Notch cultures had a reduced frequency of myotubes, and displayed unusual clusters of myocytes which had either failed to fuse or had fused incompletely . Results from mixed cultures prepared from two embryos were consistent with the autonomous expression of nerve and muscle abnormalities by Notch-8 cells in the presence of wild-type cells . It is argued that the Notch locus has a direct role in the differentiation of both nerve and muscle . (2) white deficiencies . Cells carrying either of two deficiencies gave a clear-cut pattern of abnormalities: initial cellular differentiations were normal, but nerve, muscle and fat-body cells progressively deteriorated during the culture period . Mixed cultures showed that wild-type cells could not 'rescue' mutant muscle and fat-body cells; however, the status of the autonomy of mutant nerve abnormalities in these cultures was unclear . Both white deficiencies remove cytological band 3C1, and this permits a comparison of results with those from cultures of cells from Notch-8 embryos (also deficient for 3C1) . Abnormalities displayed in cultures of the two types of mutant show no overlap . Therefore no consistent cellular abnormality can be attributed to absence of band 3C1 . (3) lethal(1)myospheroid . In contrast to earlier observations on in vitro cell cultures (Donady & Seecof, 1972) muscle was seen to differentiate, though its morphology was extremely abnormal . Observations indicated that all cell types within the cultures had poor properties of adhesion to a glass substrate . It is argued that the observed abnormalities are not consistent with a mutant lesion which is restricted to the basement membrane (contra Wright, 1960), and that all cell types carry a basic defect which may reside in the cell membrane . (4) shibirets alleles . Cultures of two temperature-sensitive lethal shibire alleles (shits1), shits3) were normal at the permissive temperature of 22 degrees C . At the restrictive temperature (29 degrees C) early cell differentiation was normal but subsequent development was blocked . This blockage could be partially reversed by shifting cultures to the permissive temperature after as much as 10 days exposure to the high temperature . It is suggested that shits cells are mutant in a process which is basic to several cell types.

J Embryol Exp Morphol, 1978 Jun, 45, 161 - 72
Cell culture of individual Drosophila embryos . I . Development of wild-type cultures; Cross DP et al.; A new procedure is described for the preparation of in vitro cell cultures from individual early gastrulae of Drosophila melanogaster . In these cultures several identifiable cell types differentiate within 24 h (nerve, muscle, fat-body, haemocyte and chitin-secreting); their initial appearance and continuing development over a period of weeks is described . It is proposed that this technique may be used to analyse abnormalities of cellular development in embryonic lethal mutants . Culture in vitro of cells from lethal embryos is seen to have two broad roles: (1) to test the developmental capacity of individual cell types in a situation where they are relatively free from possible deleterious interactions with other cell types and are liberated from the system of the dying embryo, and (2) through the preparation of mixed cultures from normal and mutant embryos, to determine the influence of the presence of wild-type cells on observed abnormalities of a particular cell type.

Brain Res, 1978 May 19, 147(1), 1 - 15
A quantitative electron microscopic study of synapse formation in dispersed cell cultures of rat cerebellum stained either by Os-UL or by E-PTA; Burry RW et al.; Synapse formation was followed in dispersed cell cultures of rat cerebellums stained either by osmium-uranyl-lead (Os-UL) or by ethanolic phosphotungstic acid (E-PTA) . The numerical densities of synapses stained by Os-UL were always significantly higher than those stained by E-PTA (from 3 to 35 days in vitro) . This difference suggests that some portion of the populations of both immature and mature synapses was not stained by E-PTA . The width of the synaptic cleft (28.4nm) in synapses stained by E-PTA was only 9nm more than that of the cleft in synapses stained by Os-UL (19.4nm), suggesting that some portion of one or both of the synaptic membranes is stained by E-PTA . Analysis of data from 7 other staining procedures utilizing both ethanolic and aqueous solutions demonstrated that the differences in cleft width described above appear to be due to the various affinities of the stains for different portions of synaptic membranes, and do not represent differences due to shrinkage artifact . In examining the parameters of synaptic structure during development of the cultures, a statistically significant increase in both the height and width of the presynaptic dense projections was found . Changes in synaptic morphology during synaptogenesis in this culture system were similar to those reported for the cerebellar cortex in vivo.

C R Acad Sci Hebd Seances Acad Sci D, 1978 May 16, 286(19), 1411 - 6
{Permanent cell culture of a pancreatic carcinoma induced by immunological effect . Comparison of the evolution of secretory specificity and oncogenic power in two homologous strains: in vitro (147-8) and in vivo (7-4)}; Thomas JA et al.; A permanent epithelial cell strain, named 147-8, was established in vitro from a pancreatic carcinoma immunologically induced in a mouse . The cells remain isolated and grow actively in suspension: after more than 3 years of life, the doubling time is 14 hrs . Some cells synthetized insulin during the first two months . Later on, the cells contain low but significant levels of amylase and lipase, even during the second year, thus showing some pancreatic specificity . The oncogenic property of this strain is high during the first two years, and later decreases while their multiplication rate remains high . The evolution of 147-8 strain is compared to that of its in vivo homologous strain 7-4.

Natl Cancer Inst Monogr, 1978 May, (48), 259 - 62
Cell culture for the study of epithelial cells; Green H; Keratinocytes depend on the support of fibroblasts or fibroblast products to grow from single cells into colonies . The essentials of a human stratified squamous epithelium can be constructed from single human epidermal keratinocytes and lethally irradiated fibroblasts . Established lines of mouse keratinocytes obtained from teratomas have many of the same properties . In this way it is possible to study many aspects of this epithelial tissue or organ under essentially cell culture conditions.

In Vitro, 1978 May, 14(5), 476 - 8
Long-term storage of tissue samples for cell culture; Taylor HA et al.; The establishment of cultured cell lines from skin biopsies stored at -196 degrees C for periods up to 1 year has been investigated . Attempts to initiate cell cultures from the frozen tissue samples were uniformly successful . There was no alteration in chromosome constitution, morphological appearance, or specific activities of lysosomal enzymes in cells cultured from the stored samples . This process can safeguard against failure of the initial tissue culture and provide an alternate means of storing viable cells when it is impossible or impractical to initiate a cell culture immediately.

In Vitro, 1978 May, 14(5), 418 - 27
A diploid rat liver cell culture . IV . Malignant transformation by aflatoxin B1; Schaeffer WI et al.; Chronic exposure of a cloned rat hepatocyte culture (RL-PR-C) to a subtoxic, sublethal dose of aflatoxin B1 resulted in malignant transformation . Continuous exposure to aflatoxin B1 caused increasing tumorigenic potential as tested by back injection into isogenic animals . Control cultures exhibited spontaneous transformation, although approximately 20 passages beyond the chemically induced event . Neither aflatoxin-treated nor control cultures exhibited cytopathological morphology, formation of cell foci, growth in soft agar, or irregular fibroblast-like growth patterns that could be specifically related to the onset of tumorigenic potential . In general, those parameters commonly used to monitor fibroblast cultures for transformation in vitro were not applicable for assessing the tumorigenic potential of these epithelial cells . Karyotypic analyses revealed no specific chromosomal aberrations associated with aflatoxin treatment; however, chromosomal instability was a property of the tumorigenic cell populations . Injection of both aflatoxin-treated and control cultures at passage 56 resulted in tumors indicative of both carcinoma and sarcoma indicating to us the multipotency of these epithelial cells transformed in vitro.

Exp Hematol, 1978 May, 6(5), 468 - 72
Serum erythropoietin measurements using the fetal mouse liver cell culture: the importance of reduction of variation in the specific activity of radioiron--transferrin; Radtke HW et al.; Because of varying iron--transferrin concentrations in different serum samples, and varying test serum portions within the culture, variations of the radioiron--transferrin/total iron--transferrin ratio are inevitable, when serum erythropoietin (Ep) concentrations are measured using the fetal mouse liver cell assay . It could be demonstrated that radioiron uptake is directly proportional to the specific activity of radioiron--transferrin, when the latter varies over the range which is inherent to the method . Variations of the ratio of radioiron--transferrin/total iron--transferrin were reduced by preincubating radioiron with human transferrin, and by minimizing the test serum portion of the culture . With this modified in vitro bioassay, serum Ep concentrations of 59 healthy subjects were measured . Mean serum Ep concentration was 136 +/- 66 (s.d.) mU/ml.

Biull Eksp Biol Med, 1978 May, 85(5), 605 - 8
{Characteristics of mitosis pathology in a Chinese hamster cell culture with disorders of the protein-synthesizing system}; Alov IA et al.; Disturbance of protein synthesis with puromycin and transcription of chromosomal and ribosomal RNA with actinomycin D was followed by marked changes in the normal course of mitosis . There was noted an increase in number of colchicin-like mitoses (C-mitoses), and particularly, sometimes, fragmentation of their cytoplasm with the formation of cluster-like structures . It is suggested that development of C-mitosis was connected not only with destruction in the mitotic apparatus formation system, but also with the block of synthesis of one of the chromosomal proteins, stabilizing DNA strands spiralization . Another form of pathological mitosis occurring under conditions of suppression of the metabolic processes ("hollow metaphase plate") was linked not only with the chromosomal alterations . Selective suppression of the ribosomal RNA transcription led to an evident anaphase delay and to coupling of telomere regions of chromosomes . This phenomenon is apparently associated with destruction of the "protective cover" of chromosomes, formed by RNA of the disintegrating nucleoli and RNA of perichromatin granules.

J Pharm Sci, 1978 May, 67(5), 606 - 10
Kinetics of drug transport and concurrent metabolism in human cell cultures I: theory; Ando HY et al.; A method for evaluating the passive permeability and single-step metabolism of drugs in suspension cultures of mammalian cells was formulated assuming linear kinetics . It was assumed that the metabolizing enzymes are driven by endogenous substrates present in steady-state quantities . The presence of the drug in radiolabeled tracer quantities was assumed to cause only a small perturbation from the endogenous steady-state operating point . The time course solutions for the drug and its metabolite are given in terms of macroscopic constants, and their physical interpretations are given in terms of metabolic and transport parameters.

Vopr Virusol, 1978 May-Jun, (3), 337 - 42
{Cytologic and histochemical study of cell cultures chronically infected with fixed rabies virus}; Andzhaparidze OG et al.; Cytoplasmic inclusion bodies corresponding in their tinctorial properties to Negri bodies were detected in TEp-2/2 and BHK-21/13S cell cultures chronically infected with fixed rabies virus . The number of cells containing the inclusions was always than that of the cells producing virus-specific antigen . Histological examinations of chronically infected cultures revealed considerable inhibition of the acid phosphatase activity, some weakening of the reaction to alkaline phosphatase, and a marked decline in the activity of succinate dehydrogenase . The intensity of reaction to RNA in chronically infected cultures was increased, particularly in those zones of the cells where RNA-containing inclusions were detected . The activity of the respiratory enzyme HAD-H2 tetrasolium reductase in HEp-2/2 cells was reduced and in BHK-21/13S cells increased as compared to the control.

In Vitro, 1978 May, 14(5), 443 - 50
Artificial capillary perfusion cell culture: metabolic studies; Ehrlich KC et al.; Glucose, lactic-acid, and oxygen metabolism of BHK and L929 cells on artificial capillary perfusion units have been studied using several different modes of perfusion . After 7 to 10 days, cells planted in the extracapillary compartment of culture units containing 80 to 150 fibers reached populations that used 0.073 +/- 0.025 mumol per min glucose and 0.76 +/- 0.26 microliter per min oxygen and excreted 0.078 +/- 0.038 mumol per min lactic acid . From these data it is estimated that these units contain approximately 2 x 10(7) cells . The metabolic rate of cultures perfused through the capillaries or through the extracapillary compartment was not affected significantly by change in flow rate except at perfusion flow rates less than or equal to 0.05 ml per min . The cell population, as measured by metabolic activity, did not increase significantly when the serum content of the medium was less than or equal to 1% . No major differences were found in glucose utilization rates of equal numbers of cells on artificial capillaries, on short-term suspension culture, or as monolayers in plastic flasks . Artificial capillary perfusion may provide a simple system for studying metabolism of mammalian cells in culture.

Proc Natl Acad Sci U S A, 1978 May, 75(5), 2311 - 4
Interactions between adenovirus, a tumor promoter, and chemical carcinogens in transformation of rat embryo cell cultures; Fisher PB et al.; The tumor-promoting agent 12-O-tetradecanoyl-phorbol-13-acetate (TPA) caused a 2- to 3-fold enhancement of transformation of secondary rat embryo cells that had been injected with a temperature-sensitive mutant of adenovirus type 5(H5ts 125) . In addition, transformed foci appeared earlier and were larger in cultures grown in the presence of TPA . The addition of TPA could be delayed until up to 7 days after viral injection and still enhancement was observed . Exposure of the cells to 7,12-dimethylbenz{a}pyrene prior to H5ts125 infection also resulted in a 2- to 4-fold enhancement of transformation, and this enhancement was further augmented 2- to 3-fold when cells were grown in TPA after virus infection . Whereas TPA did not enhance the cloning efficiency of normal rat embryo cells, it did enhance the cloning efficiency of isolated colonies of adenovirus-transformed cells when these were grown alone or cocultured with a 100-fold excess of normal rat embryo cells . The enhancement of adenovirus transformation by TPA appears to be due to its ability to facilitate expression of the transformed state rather than an effect on virus uptake or integration.

Am J Pathol, 1978 May, 91(2), 277 - 98
Osteogenesis and chondrogenesis in transplants of Dunn and Ridgway osteosarcoma cell cultures; Hanamura H et al.; Dunn osteosarcomas synthesize 2 times more alkaline phosphatase than do Ridgeway osteosarcomas, 3 times more than do HeLa cells, and 4 to 5 times more than do rat or mouse fibroblast cell cultures . Implants of killed freeze-dried Dunn cell cultures into the thigh muscles are resorbed and replaced by normal cartilage, bone, and bone marrow tissue, while implants of freeze-dried Ridgeway cells are resorbed and replaced by fibrous tissue only . Outgrowths of normal muscle septum connective tissue cells onto the stroma of Ridgeway tumors differentiate into fibrous tissue . Cultures of either tumor on a substratum of bone matrix stroma prepared from normal bone proliferate, assume a spherical shape, and perpetuate the transformed osteoblast-like cell without forming attachments or adapting to the contour of the substratum . Outgrwoths of muscle mesenchymal cells on the Dunn tumor stroma differentiate into cartilage . Dunn osteosarcoma cell cultures proliferate on the inside and produce deposits of normal bone (not tumorous bone) on the outside of diffusion chambers . Killed freeze-dried cell cultures produce transfilter deposits of normal bone and bone marrow, but the quantity is significantly lower . On a substratum of cellulose acetate, outgrowths of muscle connective tissue will differentiate into cartilage when cell-free Dunn stroma is present under the organ culture grid . Tumorigenesis and normal cartilage and bone morphodifferentiation are antithetic, but tumor cells transfer a bone morphogen similar to the bone morphogenetic protein (BMP) of normal bone matrix . BMP recruits mesenchymal cells to proliferate and differentiate into cartilage and bone.

Ann Microbiol (Paris), 1978 May-Jun, 129(4), 567 - 70
{Unmasking effect of trypsin on Sendai virions obtained in KB cell cultures (author's transl)}; Guriraud-Simplot A et al.; The infectivity of virus grown in KB cell cultures can be directly activated by trypsin . Thus the fit conditions for seeding are effected from subculture to subculture if the cell inoculum is pretreated by trypsin.

Vet Med (Praha), 1978 May, 23(5), 289 - 304
{Immunofluorescence with the PI-3 virus--study of various working conditions for the detection of viral infection using immunofluorescence on various types of cell cultures}; Zuffa A et al.; We used the fluorescence method for the investigation of the sensitivity of several kinds of cell cultures to the infection with the parainfluenza virus 3 (PI-3) . Cultures from calf kidneys were the most sensitive while we did not determine any differences between primary cultures and cultures of the first and second subpassages and/or freshly cultivated or incubated cultures over seven days at a temperature of 37 degrees C . Equal values of infection titres like on the cultures of calf kidneys were determined by immunofluorescence also on the kidney cells of lambs though the presence of the infection was not accompanied by cytopathic changes . Infection of pig kidney cells appeared only after the inoculation of 10(3) TKID50 and higher doses of the virus, the infection having a very slow course of development without detectable cytopathic changes . Fluorescent findings were identical in different tissues . Antibodies present in the culture medium stopped the spreading of the infection by neutralizing the virus released from the cells, however, not the primary infection . The increase in the content of antibodies in the medium led - by inhibiting the intercellular virus - to the slowing down of the growth of primary fluorescent lesions.

J Histochem Cytochem, 1978 May, 26(5), 391 - 400
Flow microfluorometric analysis of herpesvirus infected BHK-21 and BALB/3T3 cell cultures; Dunn J et al.; The interaction of herpes simplex type 1 with two eukaryotic cell lines (BHK-21 and BALB/3T3) was investigated by flow microfluorometric analysis after cell staining with mithramycin . Uninfected, lytically infected and persistently infected cell populations were examined . Viral replication within an infected cell population could be detected via FMF analysis . The low levels of viral replication occurring within persistently infected cell populations were also detectable . A marked degree of correlation was noted between morphological observations of infected cultures and the FMF profiles obtained . The results deomonstrate the great potential of this technique for the early detection and analysis of viral infection.

J Gen Virol, 1978 May, 39(2), 303 - 10
Regulation of interferon production by dibutyryl cyclic GMP in serum-free human diploid cell cultures; Yoshida I et al.; The mechanism for regulating interferon production was investigated in relation to accentuation of production in serum-free human diploid cells (strain WI-38) treated with N2,O2-dibutyryl guanosine 3',5'-cyclic monophosphate (db-cyclic GMP) . Interferon production in serum-free WI-38 cell cultures in response to Newcastle disease virus (NDV) was greatly reduced . In these cells, there was decreased incorporation of 5-3H-uridine into the acid-insoluble fraction, but unimpaired incorporation of U-14C-L-leucine, as compared with serum-containing cultures . When serum-free cell cultures were treated with 0.2 mM-db-cyclic GMP, incorporation of both 5-3H-uridine and U-14C-L-leucine was increased and there was an 8-fold enhancement in the yield of interferon in response to NDV . Induction of db-cyclic GMP-treated cells by NDV in the presence of cycloheximide and actinomycin D suggests that db-cyclic GMP enhances transcription of the interferon gene, and thereby augments interferon production.

J Gen Virol, 1978 May, 39(2), 205 - 17
Morphogenesis of porcine rotavirus in porcine kidney cell cultures and intestinal epithelial cells; Saif LJ et al.; The morphogenesis of porcine rotavirus was similar in vitro in porcine kidney (PK) cell cultures and in vivo in porcine epithelial cells as examined by electron microscopy . Infected cells contained cytoplasmic, non-membrane-bound viroplasm and accumulations of virus particles within cisternae of the rough endoplasmic reticulum (RER) . Three types of virus particles were noted: double-shelled or complete particles which averaged 77 nm in diam.; single-shelled or naked particles which ranged from 50 to 55 nm in diam.; and electron-dense nucleoids, or cores, 31 to 38 nm in diam . Virus particles acquired outer shells by budding through either matrices of granular, electron-dense viroplasm or membranes of distended RER . Accumulation of numerous single-shelled particles was observed only in PK cell cultures containing a high percentage of infected cells . In these cells, virus release occurred through disruption of the plasma membrane . Tubules, similar in diameter to the single-shelled particles, were observed in the nuclei of a few infected PK cells.

Cancer Res, 1978 May, 38(5), 1317 - 22
Activities of key gluconeogenic enzymes and glycogen synthase in rat and human livers, hepatomas, and hepatoma cell cultures; Hammond KD et al.; The activities of pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK), glucose-6-phosphatase (G6Pase), and glycogen synthetase (GS) were determined in the cancerous and in the apparently uninvolved (host) regions of livers from primary hepatoma patients as well as in normal adult human livers and human fetal livers . The activities of these enzymes were also assayed in a fairly fast-growing, 3'-methyl-4-dimethylaminoazobenzene-induced transplantable rat hepatoma and in hepatoma cell lines derived from both rat and human tumors . In the human hepatoma, as in the rat hepatoma, the activities of PC, PEPCK, and G6Pase were considerably reduced, compared to those in the host liver . The activities of both the a (glucose 6-phosphate-independent) and b (glucose 6-phosphate-dependent) forms of GS were also lower in human and rat hepatomas than in the respective host livers . Activities of PC, PEPCK, and G6Pase in the human hepatomas were often comparable with those of fetal livers . In rat and human hepatoma cells, the activities of PC, PEPCK, and G6Pase were similar to or lower than the activities in the respective hepatomas; the activities of GS a were also similar to those in the hepatoma, whereas the activities of GS b were somewhat higher.

Z Naturforsch {C}, 1978 May-Jun, 33(5-6), 359 - 62
Messenger ribonucleoprotein particles from plant cell cultures; Pfisterer J; Messenger ribonucleoprotein particles were isolated from the polysomes of logarithmically growing plant cell cultures, pulse-labeled with {3H} adenosine for 30 min . More than 80% of the labeled RNP was present in particles sedimenting between 80 S and 30 S on sucrose density gradients, but was not associated with ribosomal subunits . The size distribution differs from those reported for polysomal mRNP particles to date . After fixation with glutaraldehyde the labeled RNP particles had a buoyant density of 1.38 g/cm3 in CsCl gradients . Radioactively labeled RNA extracted from the RNP particles showed a heterodisperse size distribution and contained poly (A) stretches as determined by affinity chromatography and ribonuclease digestion experiments.

J Virol, 1978 May, 26(2), 536 - 9
Production of "rapid-harvest" Moloney murine leukemia virus by continuous cell culture on synthetic capillaries; Ratner PL et al.; Moloney murine leukemia virus was harvested automatically within 60 min of release from chronically infected NIH/3T3 cells (clone 1) cultured on bundles of synthetic capillaries . Production of virus as measured by a determination of reverse transcriptase activity and by the XC syncytia assay demonstrated that highly infectious "rapid-harvest" virus was recovered from NIH/3T3 cells (clone 1) grown for periods of up to 10 days.

Acta Virol, 1978 May, 22(3), 218 - 24
Morphological characteristics of the infection of animals with tick-borne encephalitis virus persisting for a long time in cell cultures; Andzhaparidze OG et al.; The pathogenicity of the Soph-K strain of tick-borne encephalitis (TBE) virus produced by the persistently infected HEp-2-Soph cell culture was investigated in monkeys, white mice and hamsters . The persistent infection of this culture with TBE virus has been maintained for 17 years . The Soph-K strain was shown to retain its pathogenic properties for mice of different ages and hamsters . Morphological examinations of the brains and spinal cords of these animals infected with the Soph-K strain revealed acute and subacute forms of encephalitis . Monkeys inoculated with the Soph-K strain intracerebrally showed an asymptomatic infection with the pathomorphological picture of subacute disseminated meningoencephalitis with a progredient course for 3 months of observation . This chronic TBE infection in monkeys offers an interesting model for investigations on progressive degenerative disease of the nervous system.

J Biol Chem, 1978 Apr 25, 253(8), 2882 - 91
Skeletal muscle acetylcholine receptor . Purification, characterization, and turnover in muscle cell cultures; Merlie JP et al.; Acetylcholine receptor has been purified from embryonic skeletal muscle cells grown and allowed to differentiate in tissue culture . The polypeptide composition of purified receptor has been determined by two-dimensional electrophoresis . The purest preparations are composed of a single Mr = 41,000 class of polypeptide which exhibits some charge heterogeneity . By high resolution two-dimensional electrophoresis a spot corresponding to acetylcholine receptor was localized among total proteins of muscle membrane extracts . Synthesis of this component is shown to be developmentally regulated . Quantitative analysis of receptor synthesis and degradation has led to the conclusion that receptor is one of a class of proteins whose synthesis is tightly regulated during terminal steps of myogenesis.

Clin Genet, 1978 Apr, 13(4), 327 - 34
Cystic fibrosis: cell culture classes in a Danish population; Danes BS et al.; The cystic fibrosis (CF) culture phenotype of dermal fibroblasts (metachromasia, metabolic cooperation) of a group of 131 Danish CF patients and their families were studied to determine the distribution of the two CF culture classes and their prognostic significance . Of these, 62.6% (82) were Class I, 31.3% (41) Class II and 61.1% (8) were proposed to be genetic compounds . The occurrence of Class II was twice that found in a group of patients from New York (13%) and Minnesota (18%) . The prognosis for Class II CF patients was considered to be poorer as: (1) The initial diagnosis was made earlier in Class II than in Class I or the compounds (63% of Class II were diagnosed in the first year of life, as compared to 35% in Class I and 13% of the compounds) . (2) Only 5% of the Class II patients survived over the age of 15 years, both being deceased at the end of the study in 1976, whereas 24% of Class I and 63% of the compounds were over 15 years at the end of the study . This research added further evidence for genetic heterogeneity within the clinical syndrome, cystic fibrosis.

J Med Genet, 1978 Apr, 15(2), 136 - 42
Significance of detection of extra metacentric microchromosome in amniotic cell culture; Bernstein R et al.; A metacentric bisatellited microchromosome was detected in all metaphases from an amniotic culture performed because of maternal age . A wide-ranging survey of the literature failed to disclose any consistent anomaly associated with such a marker, but did reveal that the clinical picture of patients manifesting it could range from complete normality through mental retardation to a variety of deformities . The parents elected for termination, and the only deformity detected in the abortus was fixed talipes equinovarus . The implications of the finding of this marker chromosome on amniocentesis, believed to be reported for the first time here, are discussed particularly in the context of genetic counselling.

J Natl Cancer Inst, 1978 Apr, 60(4), 797 - 801
Replicative epithelial cell cultures from normal human prostate gland; Lechner JF et al.; Epithelial cell cultures of the normal human prostate gland were established . The subculturing of these cultures was accomplished with a novel nonenzymatic technique . These cultures were defined as normal epithelial cells on the basis of ultrastructure, karyotype, and inability to grow in soft agar.

J Cell Biol, 1978 Apr, 77(1), 83 - 98
Enrichment of spinal cord cell cultures with motoneurons; Berg DK et al.; Spinal cord cell cultures contain several types of neurons . Two methods are described for enriching such cultures with motoneurons (defined here simply as cholinergic cells that are capable of innervating muscle) . In the first method, 7-day embryonic chick spinal cord neurons were separated according to size by 1 g velocity sedimentation . It is assumed that cholinergic motoneurons are among the largest cells present at this stage . The spinal cords were dissociated vigorously so that 95-98% of the cells in the initial suspension were isolated from one another . Cells in leading fractions (large cell fractions: LCFs) contain about seven times as much choline acetyltransferase (CAT) activity per unit cytoplasm as do cells in trailing fractions (small cell fractions: SCFs) . Muscle cultures seeded with LCFs develop 10-70 times as much CAT as cultures seeded with SCFs and six times as much CAT as cultures seeded with control (unfractionated) spinal cord cells . More than 20% of the large neurons in LCF-muscle cultures innervate nearby myotubes . In the second method, neurons were gently dissociated from 4-day embryonic spinal cords and maintained in vitro . This approach is based on earlier observations that cholinergic neurons are among the first cells to withdraw form the mitotic cycle in the developing chick embryo (Hamburger, V . 1948 . J . Comp . Neurol . 88:221-283; and Levi-Montalcini, R . 1950 . J . Morphol . 86:253-283) . 4-Day spinal cord-muscle cultures develop three times as much CAT as do 7-day spinal cord-muscle plates, prepared in the same (gentle) manner . More than 50% of the relatively large 4-day neurons innervate nearby myotubes . Thus, both methods are useful first steps toward the complete isolation of motoneurons . Both methods should facilitate study of the development of cholinergic neurons and of nerve-muscle synapse formation.

Cell, 1978 Apr, 13(4), 589 - 98
Myogenesis in primary cell cultures from Drosophila melanogaster: protein synthesis and actin heterogeneity during development; Storti RV et al.; Muscle cell cultures from Drosophila melanogaster were obtained by plating dissociated gastrula stage embryo cells on protamine-treated culture dishes . They myogenic cells in these cultures fuse to form multinucleated pulsating cells by 15 hr after plating . An analysis of protein synthesis during myogenesis in these cultures, as measured by the incorporation of 35S-methionine and analyzed by two-dimensional polyacrylamide gel electrophoresis, showed profound changes in the pattern of protein synthesis . This analysis enabled us to identify three distinct classes of proteins . Class A proteins, the most abundant, are synthesized continuously throughout myogenesis, class B proteins are those proteins whose synthesis is initiated during myogenesis and continued throughout development; class C proteins are those synthesized at specific times during development . In addition, three forms of actin have been identified in these cultures . Actin I, which shows increased synthesis concomitant with the myogenic development in these cultures, is apparently a muscle-specific form of actin . Actin II, the predominant "cytoplasmic" form of actin in the nonmuscle Schneider cell line 2, is also the major form in the gastrula cultures before differentiation begins . Synthesis of this actin continues in the myogenic cultures . Actin III is a rapidly turning over form of actin which does not accumulate in either the Schneider cells or the myogenic cultures.

Infect Immun, 1978 Apr, 20(1), 66 - 8
Propagation of Pneumocystis carinii in Vero cell culture; Pifer LL et al.; Pneumocystis carinii derived from infected murine lung was found to be capable of limited growth in Vero African green monkey kidney cell cultures . The observed increase in the number of cyst forms was influenced by the ratio of cysts to host cells in the inocula, duration of passage, and formulation of the cell culture media . Maximum growth was achieved by inoculating 1.3 X 10(5) cysts per 75-cm2 flask containing about 2 X 10(7) Vero cells (cyst-to-cell ratio=1:154) maintained on minimal essential medium supplemented with 2% fetal bovine serum . Under these conditions of culture, a 10.8-fold increase in cyst forms was observed during a 7-day passage in cell culture utilizing cyst-to-cell ratios ranging from 1:28 to 1:2,778.

Proc Natl Acad Sci U S A, 1978 Apr, 75(4), 1864 - 6
Density-dependent regulation of growth of BSC-1 cells in cell culture: growth inhibitors formed by the cells; Holley RW et al.; Inhibitors formed by a monkey epithelial cell line, BSC-1, play an important role in limiting growth at high cell densities . At least three inhibitors are formed: lactic acid, ammonia, and an unidentified inhibitor that may be an unstable protein . The unidentified inhibitor is destroyed by shaking the conditioned medium, by bubbling gas through the medium, or by heating or storing the medium in the absence of cells . The concentrations of lactic acid and ammonia that accumulate in conditioned medium inhibit growth when added to fresh medium . These results, together with earlier studies, indicate that density-dependent regulation of growth of BSC-1 cells results from the combined effects of (a) inhibitors formed by the cells, (b) decreased availability of receptor sites for serum growth factors as the cells become crowded, and (c) limiting concentrations of low molecular weight nutrients in the medium . In contrast, density-dependent regulation of growth in 3T3 mouse embryo fibroblasts results almost entirely from inactivation of serum factors.

Virologie, 1978 Apr-Jun, 29(2), 117 - 21
Isoenzymes of lactate dehydrogenase, acid phosphatase, alkaline phosphatase and peroxidase in monkey kidney cell cultures inoculated with herpes virus type 1; Esanu V et al.; The variation of lactate dehydrogenase, peroxidase, acid and alkaline phosphatase isoenzymes was studied in VERO cells inoculated with infectant and UV-inactivated herpes simplex virus type 1 (HSV--1) . Infectant HSV--1 induced quantitative and qualitative modifications in isoenzyme patterns within the first 4 hours post inoculation (p.i.) . The modifications caused by the UV-inactivated HSV--1 were similar, but appeared 8 hours p.i . The possibility of using isoenzyme modifications as rapid, sensitive and specific biochemical tests for virus detection and differentiation between infectant and inactivated virus is discussed.

Cell, 1978 Apr, 13(4), 775 - 82
MAC-1, a new genetically transmitted type C virus of primates: "low frequency" activation from stumptail monkey cell cultures; Todaro GJ et al.; A new class of endogenous primate type C virus has been isolated from a continuous tissue culture line of Macaca arctoides cells by co-cultivation with a human cell line . The virus, designated MAC-1, can be transmitted to human and feline cells in tissue culture, and is unrelated, by immunological and nucleic acid hybridization criteria, to previously characterized retroviral isolates of primates . In particular, MAC-1 shows no detectable homology to the baboon type C viruses, even though viral genes related to the latter group are readily detected in M . arctoides cellular DNA . Viral gene sequences related to the MAC-1 genome are present in multiple copies (50-150 per haploid genome) in Old World primates, and are expressed in the cellular RNAs of uninfected and "virus-free" primate cells and tissues . Thus there are at least two distinct sets of genetically transmitted Old World primate type C viral genes, each of which is found in multiple copies in normal primate cellular DNA . With the description of this new retrovirus, there are now a minimum of five distinct genetically transmitted viruses of primates, three type C and type D, each represented in multiple copies in the normal cellular DNA.

Z Gastroenterol, 1978 Apr, 16(4), 251 - 6
{Regulation of hepatocyte 3-hydroxy-3-methylglutaryl coenzyme A reductase in primary cell cultures through low density lipoproteins}; Gaertner U; The regulation of hepatic cholesterol biosynthesis by low density lipoprotein (LDL) was studied by using a new cell culture method of isolated rat hepatocytes . After two days in culture no supressant effect of LDL on 3-hydroxy-3-methylglutaryl coenzyme A reductase activity (HMG-CoA) was detected . The primary culture of rat hepatocytes lead to the growth of a cell monolayer with stable liver specific properties during 4 days of culture . LDL did suppress HMG-CoA-reductase activity of rat hepatocytes in primary culture 5 days after seeding, when dedifferentiation has started.

Science, 1978 Mar 10, 199(4333), 1072 - 5
Rabies viruses increase in virulence when propagated in neuroblastoma cell culture; Clark HF; Several strains of attenuated rabies virus lacking the capacity to kill adult mice acquired a high lethal potential for mice after one to five serial passages in murine or human neuroblastoma cells . The virulence acquired after passage in neuroblastoma cells is a stable genetic trait retained during subsequent passage of viruses in nonneuroblastoma cell systems.

MMW Munch Med Wochenschr, 1978 Mar 3, 120(9), 287 - 8
{A purified rabies vaccine from human diploid cell cultures (author's transl)}; Majer M et al.; In order to improve the tolerance of rabies vaccine from human diploid cell cultures, the rabies virus antigen is purified in the sucrose density gradient by means of a flow ultracentrifuge . The purified virus has a specific infectiosity of 10(9) LD50 and a speicific activity of 250 units "relative activity" per 1 mg protein . The purified vaccine has been shown to be well tolerated, effective and stable.

J Toxicol Environ Health, 1978 Mar-May, 4(2-3), 427 - 48
Replacement of serum in cell culture by hormones: a study of hormonal regulation of cell growth and specific gene expression; Wu R et al.; The hypothesis that the growth of mammalian cells is regulated by hormones is now supported by considerable evidence . Two rat pituitary cell lines, GH3 and GC, a mouse melanoma, M2R (B16), and a human cervical carcinoma cell, HeLa S-3, have been grown indefinitely in serum-free (SF) hormone-supplemented medium . No visible changes of growth characteristics were observed in the cells grown continuously in the SF condition . However, changes in the activity of a plasma membrane enzyme, alkaline phosphatase, and in the relative intensity of surface proteins that are labeled by the {125I} lactoperoxidase technique were found in HeLa cells grown in the SF condition . To study the role of hormones required in the regulation of cell growth, HeLa cells were grown in the absence of one of the required hormones . The following results were obtained . Epidermal growth factor is probably involved in the regulation of the synthesis of macromolecules such as RNA and of the protein content per cell . Transferrin, the accessory factor in the SF condition, supplies iron for cells . The two basic peptides in this SF system, fibroblast growth factor and insulin, are probably involved in the balance of nutrients and energy inside the cell . The replacement of F12 medium with a better-balanced medium, MCDB 105, can mimic the requirements for these two peptides . The steroid hydrocortisone (HC) is probably involved in alteration of the cell surface . This is indicated by the effects of HC on cell morphology, rate of detachment from the dish, and the pattern of {125I} lactoperoxidase labeling of surface proteins . In addition, it is necessary to change the medium more frequently to maintain the culture in the medium without HC . This observation suggests that HC may be involved in the control of homeostatic properties of the cell surface . The production of rat prolactin by GH3 cells was also studied . GH3 cells in the SF condition produce 1.6 microgram prolactin per 10(5) cells in 24 h, while 2.4 microgram is produced in the presence of serum . Prolactin production in the SF condition is enhanced by the presence of thyrotropin-releasing hormone and inhibited by triiodothyronine (T3) . T3 is the major growth factor for these cells . Without it cell growth is severely limited, while prolactin production is elevated . This result suggests that the GH3 cell line in the SF condition may be an ideal system for the study of hormonal regulation of cell growth and specific gene expression.

Invest Ophthalmol Vis Sci, 1978 Mar, 17(3), 264 - 71
Partial characterization of human collagen and procollagen secreted by human corneal stromal fibroblasts in cell culture; Stoesser TR et al.; Human corneal stromal fibroblasts were established into cell culture . Fractions highly enriched for collagen and procollagen were purified from the medium and cell layer . Analysis using polyacrylamide gel electrophoresis and DEAE cellulose chromatography indicated the presence of a heterogeneous population of procollagen molecules ranging in molecular weights from 200,000 to 120,000 daltons along with alpha1 and alpha2 collagen chains . Cyanogen bromide peptides of a corneal peptide fraction migrated concomitantly with type I standard cyanogen bromide peptides.

In Vitro, 1978 Mar, 14(3), 312 - 6
Temperature and species differences in susceptibility of kidney cell cultures to mercury toxicity; Vickrey HM et al.; The effect of temperature on inorganic mercury toxicity was investigated using kidney tissue culture systems . The relative susceptibility of rabbit (homeothermic) kidney to mercury intoxication was compared to that of Coho salmon (poikilothermic) kidney to mercury intoxication was compared to that of Coho salmon (poikilothermic) kidney over temperature ranges consistent with the habitat of each of the two species . It was demonstrated that susceptibility to mercury toxicity is species dependent; that is, the rabbit kidney cells tolerated higher mercury concentrations in the medium than did the fish-derived cells . Within a given species, susceptibility to mercury toxicity was temperature dependent . Decreasing the temperature increased the toxicity of mercury to cultures of rabbit kidney cells, whereas decreasing temperatures decreased the effect of mercury toxicity on the salmon kidney cells . As a consequence, fish taken from arctic waters are liable to be more toxic when introduced into mammalian food chains . Albumin was shown to act as a protective agent in vitro against inorganic mercury toxicity.

J Bacteriol, 1978 Mar, 133(3), 1452 - 6
Positive detection of mycoplasma contamination by the whole-mount preparation of cell cultures for transmission electron microscopy; Maul G; Low-level mycoplasma contamination of cell cultures is difficult to recognize with presently available techniques . This report describes the adaptation of the whole-mount technique, usually used for scanning microscopy, for transmission electron microscopy . The differentiation between microvilli and the equal-sized filamentous mycoplasma is based on the differential density obtained by the use of the method described . This method allows positive identification of mycoplasma and reduces the preparation time and the time necessary for scanning the preparation.

Arthritis Rheum, 1978 Mar, 21(2), 249 - 55
Immunopathologic studies of rheumatoid arthritis . I . Absence of complement-dependent cytotoxicity of rheumatoid sera for rheumatoid synovial cell cultures; Paget SA et al.; A sensitive complement-dependent chromium release cytotoxicity assay was used to determine whether sera from rheumatoid arthritis (RA) patients contain antibody specific for an antigen on rheumatoid synovial cell cultures . Two hundred eight RA sera-RA synovial culture combinations were studied employing 21 sera and 16 synovial membranes; control combinations were derived from 5 normal sera and 10 degenerative joint disease synovial membranes . Anticomplementary activity of some rheumatoid sera was overcome using an increased complement concentration . The percent cytotoxicity of RA serum-RA culture combinations, both homologous and autologous, was not significantly greater than that of RA serum-control culture combinations . No correlation between duration of disease or duration of cell culture and percent cytotoxicity was found . Thus a unique antigen on cultured rheumatoid synovial cells was not recognized by rheumatoid serum antibody by use of this cytotoxicity assay.

Vopr Virusol, 1978 Mar-Apr, (2), 192 - 5
{Properties of the tick-borne encephalitis virus persisting for a long time in a chronically infected cell culture}; Andzhaparidze OG et al.; The biological properties of tick-borne encephalitis virus (Sof K) produced by chronically infected HEp-2-Sof cells at late stages of the cultivation were studied . The Sof K virus was infective for mice of different ages upon intracerebral and subcutaneous inoculation, had high immunogenicity and was completely neutralized by antiserum to the parental strain . The Sof K virus had the small-plaque phenotype and replicated with similar intensity in pig embryo cell cultures (SPEC) at 36 degrees, 42 degrees and 31 degrees C.

Vopr Virusol, 1978 Mar-Apr, (2), 165 - 9
{Chronic infection caused by the simian Mason-Pfizer virus in primate cell cultures}; Nosik NN et al.; Cell cultures of monkey prepuce (Rhfs) and African green monkey kidney (BSC-1) were infected once with simian Mason-Pfizer virus (MPV) and virus expression in the course of establishment of chronic infection was studied . The productive infection was characterized by changes in the cell metabolism (DNA synthesis increased 2-3-fold as early as the "zero" passage), the appearance of gs-antigen, formation of virions of type D and high activity of RNA-dependent DNA-polymerase . Multinuclear giant cells appeared only in the infected Rhfs cell culture most sensitive to MPV . In human embryo kidney culture (HEK) productive infection was also established however, HEK cultures did not survive after 3-4 passages . No signs of transformation could be found in any of the cultures studied.

J Protozool, 1978 Feb, 25(1), 82 - 6
Development of Eimeria meleagrimitis Tyzzer from sporozoites and merozoites in turkey kidney cell cultures; Augustine PC et al.; Sporozoites and 1st-, 2nd-, and 3rd-generation merozoites of Eimeria meleagrimitis were inoculated into primary cultures of turkey kidney cells . In vitro-excysted sporozoites developed into mature macrogamonts in 8 days; in vivo-excysted sporozoites developed into 2nd- or 3rd-generation schizonts within 5 to 7 days . First-generation merozoites obtained from infected turkeys produced mature 2nd-generation schizonts within 24 h . Second-generation merozoites from turkeys produced mature macrogamonts and oocysts within 72 h, whereas 3rd-generation merozoites produced these stages within 48 h . The oocysts that developed from 3rd-generation merozoites sporulated at 25 C and were infective for turkeys . The timing of the early stages and the intervals between schizogonic generations in cultures were comparable with those in turkeys . Morphologic parameters, however, indicated that some differences existed between in vitro and in vivo development . Second- and 3rd-generation schizonts and gamonts that developed after inoculation of cultures with merozoites were similar to stages in turkeys . Oocysts, however, were significantly smaller (P less than 0.05) in cultures . All stages that developed after inoculation of cultures with sporozoites were smaller (P less than 0.05) than their in vivo counter parts.

Cancer Lett, 1978 Feb, 4(2), 77 - 84
The identification of a cell culture inhibitor in a tumour extract; Dewey DL; An extract of Harding-Passey mouse melanoma was found to inhibit the proliferation of the same cell line grown in culture when measured by both thymidine incorporation and by the increase in cell number . The active ingredient was purified by ultrafiltration, column chromatography and preparative electrophoresis . The purified material was identified by mass spectrometry and by gas chromatography as spermidine . The partially purified material reversed the methylglyoxal Bis-guanyl hydrazone (Methyl-GAG) inhibition of cultured cells to the same extent as spermidine . Very low concentrations of Methyl-GAG were found to suppress the spermidine inhibition of thymidine incorporation into cells . The inhibitor extracted from melanoma tumours behaved in the same way as spermidine at all Methyl-GAG concentrations . Thus, it is unlikely that the active ingredient in the biological extract is anything other than spermidine.

Am J Vet Res, 1978 Feb, 39(2), 323 - 4
Elimination of porcine parvovirus from infected cell cultures by inclusion of homologous antiserum in the nutrient medium; Mengeling WL; Cell cultures of porcine fetal kidney and porcine adult thyroid gland were freed of infection with porcine parvovirus by adding homologous viral antiserum to their nutrient medium . The use of antiserum appeared practical and effective for eliminating the virus from contaminated cell lines.

J Natl Cancer Inst, 1978 Feb, 60(2), 303 - 6
Continuous production of carcinoembryonic antigen in hollow fiber cell culture units: brief communication; David GS et al.; A line of cultured cells derived from a primary human adenocarcinoma of the colon was grown in the extracapillary spaces of hollow fiber tissue culture units in the absence of serum components of high molecular weight (greater than 10,000) . The cells were capable of producing more than 30 microgram of carcinoembryonic antigen (CEA) per day, provided that the extracapillary fluid was changed frequently . The concanavalin-A binding and molecular sieve chromatography properties of the tissue culture-derived CEA were similar to those of CEA isolated from metastatic colon cancer tissue.

Gastroenterology, 1978 Feb, 74(2 Pt 1), 205 - 8
Hepatotoxicity of salicylates in monolayer cell cultures; Tolman KG et al.; The influence of graded doses of sodium salicylate on rat liver cells cultured in monolayers was assessed by measuring lactic dehydrogenase activity in a culture media after incubation . Morphological alterations were studied by electron microscopy . The influence of different albumin concentrations in the media on toxicity was also evaluated . Lactic dehydrogenase concentrations rose with increasing doses of salicylate up to 40 mg per dl . High concentrations of albumin were associated with reduced salicylate toxicity . These findings suggest that salicylate-induced hepatic injury is dose related and my be influenced by serum albumin levels

J Protozool, 1978 Feb, 25(1), 1 - 14
Acanthamoeba royreba sp . n . from a human tumor cell culture; Willaert E et al.; A new species of Acanthamoeba was isolated from a culture of an established line of human choriocarcinoma cells . The identification of this strain, originally called the Oak Ridge strain, and the establishment of a new species for it were based on morphologic, serologic, and immunochemical studies . In general, the structure of the trophozoite did not differ significantly from that of other species of Acanthamoeba, except that a body which more closely resembled a centriole than material described previously as centriolar satellites was observed in trophozoites examined with the electron microscope . The dimensions of the trophozoite were the smallest among the species of Acanthamoeba . The cyst was typical of the genus, but differed from those of other species by its smaller size and the presence of numerous ostioles . Studies of the Oak Ridge strain by immunofluorescence using antisera developed against the isolate and Acanthamoeba culbertsoni, A . castellanii, A . polyphaga, A . rhysodes, A . astronyxis, and A . palestinensis revealed the antigenic uniqueness of the Oak Ridge strain . It was demonstrated by immunoelectrophoretic analyses of the soluble proteins of the Oak Ridge strain that shared approximately 1/2 of its antigenic structure with A . castellanii and A . culbertsoni . The antigenic differences of the isolate from other species of Acanthamoeba were deduced from comparison of the antigenic constitution of these species and the Oak Ridge strain with A . culbertsoni and A . castellanii . Although the strain was initially recognized by its cytopathogenicity for cultures, it did not produce acute infections in mice after intranasal inoculation of 1 X 10(4) ameba/mouse . The foregoing results constituted the basis for the establishment of the Oak Ridge strain as a new species, A . royreba sp . n., in the genus Acanthamoeba.

J Nucl Med, 1978 Feb, 19(2), 191 - 4
Effect of cytomegalovirus infection on metabolism of WI-38 cell cultures: concise communication; Hurlburt EM et al.; The effect of cytomegalovirus on the metabolism in monolayers of human embryonic lung fibroblasts (WI-38 cells) was studied . Effects of viral infection were examined by comparing {3H} thymidine incorporation in infected cells with that in uninfected cells . The time for detecting changes in cellular metabolism using the radiometric method was compared with that for observing cytopathic effects in infected cells . Compared with uninfected cells, cells infected with 10(4) TCID50 of virus showed nearly 400% increased in {3H} thymidine uptake 48 hr after infection . The radiometric method was able to detect 10(3) TCID50 of virus, with about 250% stimulation, 24--48 hr before visible signs of cytopathic effects . Our results suggest that with further development, radiometric measurement of metabolism in cytomegalovirus-infected cell cultures might provide a means of detecting viral presence in clinical assays . The radiometric method has the advantage of objectivity and potential for automation.

J Clin Microbiol, 1978 Feb, 7(2), 214 - 8
Contamination of primary embryonic bovine kidney cell cultures with parainfluenza type 2 simian virus 5 and infectious bovine rhinotracheitis virus; Crandell RA et al.; Two different viruses were isolated from bovine embryonic cell cultures after two subcultures from the primary cells . One virus was identified as parainfluenza type 2 simian virus 5 (SV-5), and the other was identified as infectious bovine rhinotracheitis virus . Six months later, stock cultures of pig kidney (PK-15) cells were found to be contaminated with SV-5 virus . We believe that the source of the SV-5 virus in the bovine cells was a cross-contamination from monkey kidneys during preparation of the cell cultures . The infectious bovine rhinotracheitis contamination was probably of endogenous origin . The bovine embryonic cell cultures were the probable source of contamination of the PK-15 cells with SV-5 virus.

J Gen Virol, 1978 Feb, 38(2), 375 - 81
Infection of human cell cultures with bovine visna virus; Georgiades JA et al.; Fibroblastoid cell cultures derived from leukaemic bone marrow were successfully infected with BVV . After 2 months of subcultivation the cultures showed the appearance of foci of altered cells, suggestive of malignant transformation . Such foci were absent in non-inoculated cultures . Both control and inoculated cultures had a limited life span, i.e . neither of them could be developed into continuous transformed cell lines . The presence of at least some BVV genome functions in the inoculated cells was demonstrated (i) by immunofluorescence using a reference BVV serum, (ii) by detection in the supernatant culture fluid of sedimentable particles bearing RNA-dependent DNA polymerase activity with preference for Mg2+ ions, and (iii) by electron microscopic detection of scarce cell-associated virus particles in one of the infected cultures . Infectious BVV could not be rescued . In contrast to leukaemic bone marrow cultures, diploid human embryonic fibroblasts of various origin could not be infected with BVV.

J Med Virol, 1978, 2(4), 305 - 17
Subacute encephalitis and hydrocephalus in hamsters caused by measles virus from persistently infected cell cultures; Norrby E et al.; Newborn hamsters were inoculated intracerebrally with measles virus materials from Lu 106 and Vero carrier cell lines . Extracellular and cell-associated materials from cultures incubated at 37 degrees C and at 33 degrees C were used . The lower temperature allows accentuated virus replication . No animals contracted acute encephalitis, but 8 animals developed advanced neurological disease (unsteady gait, serial myoclonic jerks, hypoactivity) 79 to 212 days after injection . Seven out of these 8 animals belonged to a group of 50 animals, which had been inoculated with cell-associated material from cultures incubated at 33 degrees C . Viral antigen and nucleocapsids were found in neurons and glial cells from diseased animals, which showed degenerative changes and inflammation, particularly in the mesencephalon . Some of these animals also had hydrocephalus, which, however, also occurred in many apparently healthy animals . Also this pathological alteration occurred most frequently (5 out of 11 animals examined 9--10 months after inoculation) in hamsters receiving cell-associated material from carrier cutlures incubated at 33 degrees C . Possible mechanisms for the appearance of hydrocephalus are discussed.

Bull Cancer, 1978, 65(3), 281 - 2
Mutagenicity and carcinogenicity of 8-MOP/UVA in cell cultures; Burger PM et al.; HGPRT-deficient mutants of chinese hamster cells and human skin fibroblasts are selected with 6-thioguanine after treatment with the combination 8-MOP and UVA . Calculation based on this study indicate that 1.7 X 10(-5) mutants will be induced in the epidermis per session of PUVA therapy . Induction of cell-transformation was observed in C3H and 3T3 mouse cells.

Vopr Onkol, 1978, 24(9), 30 - 2
{Type-C viral particles in cell cultures of chemically induced glioma in Sprague-Dawley rats}; Anzil AP et al.; Long-term cultures of a glioma induced in a Sprague-Dawley rat exposed to methylnitrosourea were examined by thin-section electron microscopy . Budding and extracellular lying C-type virus particles were numerous in several samples of the highpassage cultures . This is the first report of a chemically induced rat glioma associated with C-type virus particles . Studies with an aim to characterize this rat glioma associated virus are in progress.

Neoplasma, 1978, 25(3), 309 - 15
The suitability of different quantitative methods for determination of the cytotoxic activity of agents in cell cultures; Horakova K et al.; Studies related to the measurement of growth inhibition of HeLa cells by 6-Thioguanine (TG) and Vermiculine (V) have been described . Control and treated cell populations were enumerated as uniform suspensions of whole cells, prepared by standard treatment with trypsin . Determination of cell number, measurements of protein, DNA and RNA as well as of glucose consumption from the culture medium were made throughout the treatment with the studied drugs . It was apparent that the total cell number in control cultures was directly proportional to the total cell protein or nucleic acids . However, in both treated cultures the relationship between these parameters was disturbed as consequences to unbalanced growth which was an integral part of the cytotoxic reaction of the studied agents . From the results presented it followed that only the direct cell enumeration was suitable for the detection of agents' cytotoxicity.

Neoplasma, 1978, 25(3), 285 - 90
Effects of tumor cell culture supernatants on macrophages; Moldoveanu R et al.; It is proved that supernatants of various tumor cell cultures, as well as cell-free ascitic fluid and sera from tumor bearing animals induce the detachment of macrophages from glass, the loss of their ability to form pseudopodia, the inhibition of their migration and the permeability alteration of their membranes . The cytotoxic effect is not produced by normal tissues, excepting placenta . The effect of tumor cell culture supernatants depends on the characteristic evolution time of each tumor; irradiation diminishes this effect . The involvement of macrophages in immune surveillance and response makes the results interesting for the tumor-host immune relation.

Ontogenez, 1978, 9(3), 253 - 61
{Change in the concentration and intensity of synthesis of RNA in cell cultures of Chironomus thummi during metamorphosis}; Zakharenko LP et al.; The content and intensity of incorporation of 3H-uridine in RNA of chromosomes, nucleoli and cytoplasm isolated by microsurgery from the salivary glands of larvae and prepupae of Chironomus thummi were studied following the incubation of salivary glands in the Cannon's medium with 3H-uridine . It was shown that during metamorphosis the content of RNA and intensity of 3H-uridine incorporation decrease in the nucleolus and cytoplasm in a prepupa, as compared with a larva, and suffer no changes in chromosomes in spite of much larger size of many puffs in a prepupa . The patterns of RNA synthesis in the salivary glands of larvae during metamorphosis are discussed.

Vopr Med Khim, 1978 Jan-Feb, 24(1), 84 - 7
{Effect of 1-D-ribofuranosyl-1,2,4-triazol-3-carboxamide on the synthesis of cellular macromolecules in cell culture}; Pushkarskaia NL et al.; Ribovirine (I-D-ribofuranosyl-1,2,4-triazol-3-carboxamide) possesses the distinct antiviral action against many strains of RNA- and DNA-containing viruses . Data on the effect of ribovirine on the synthesis of cellular macromolecules are presented . After treatment with ribovirine the synthesis of cellular RNA was inhibited by 80-85% . The synthesis of DNA and proteins was decreased less distinctly . The experiments were carried out using the primary tryptic-treated culture of fibroblasts from chicken embryos.

Arch Virol, 1978, 57(1), 63 - 75
In vitro studies on Borna virus . I . The use of cell cultures for the demonstration, titration and production of Borna virus; Danner K et al.; Borna virus produces non-lytic infections in a wide spectrum of primary cell cultures and cell lines . The sensitivity and virus yields vary with the different cell systems . Accurate virus titrations can be performed in the RK 13 cell line by counting immunoflourescent microfoci between the 5th and 10th day after infection . Since the virus is not released from the cells and does not spread via the culture medium, the use of a semisolid overlay in unnecessary in virus titrations . The cell line most productive for Borna virus is the CV 1 line . The conditions for optimum virus production include a prolonged cultivation period of at least two weeks with regular changes of medium, and an incubation temperature of 35 degrees C . Harvest of the virus requires thorough disruption of the infected cells, preferably by ultrasonication, since Borna virus seems to be closely associated with cellular structures.

Tsitologiia, 1978, 20(1), 66 - 73
{Effect of mitomycin C on SPEV cell cultures}; Struve ME et al.; Mitomycin C (in doses of 0.5-1.5 mkg/ml during 24-72 hours) significantly changes the ultrastructure and morphology of porcine embryo kidney cells (condensation of chromatin and the mitochondrial matrix, expansion of small channels in the endoplasmatic reticulum, total hypertrophy of the nuclei and cells) . In the given case, mytomycin C sharply inhibits DNA synthesis and mitotic activity, considerably more weakly reduces RNA and protein synthesis, raises the activity of lactate and alpha-glycerophosphate-dehydrogenases . The disbalance of syntheses leads to protein accumulation in the cells, and general enlargement of nuclei and cells . As the action of the antibiotics increases, the ultrastructural changes progress and lead to the destruction of a considerable part of cells in the culture.

Arch Virol, 1978, 56(1-2), 181 - 7
Persistent infection of primary human cell cultures with rubella variant carrying DNA Polymerase activity; Sato Mmaeda N et al.; Infection of primary human cells with a rubella variant carrying DNA polymerase activity resulted in persistent infection; infection with wild type virus caused death of the infected cells and a cytopathic effect.

Kosm Biol Aviakosm Med, 1978 Jan-Feb, 12(1), 47 - 52
{Mammalian cell culture reaction to the action of a constant magnetic field of 1000 and 3000 Oe intensity}; Vnukova ZE; The effect of a constant magnetic field of 1000 and 3000 oersted on mammalian cell cultures was examined . The effect of prolonged (12 days with three successive subcultures) and short-term intermittent action (repeated 6 times 60 min exposures with a 60 min interval) was studied . The magnetic effect was evaluated with respect to variations in the cell population density, mitotic activity and cytogenetic parameters . The experimental findings indicated that the magnetic fields of the above strength did not change significantly the rate of cell division and cell morphology neither did alter the genetic apparatus at the chromosomal level.

Z Allg Mikrobiol, 1978, 18(7), 501 - 10
{Electronoptical studies of the effect of 1-{p-(methylnitrosamino)-benzylidenamino}-adamantane on the fowl plague virus (FPV) in cell culture}; Zopel P et al.; The adamantanamine derivative 1-{p-(methylnitrosamino)-benzylidenamino}-adamantane (MBAA) at a concentration of 40 microgram/ml demonstrated no effect on adsorption of fowl plague virus (FPV) on chick embryonal cells . The penetration of the virions took place by means of pinocytosis . In the final stages of penetration the virions became gradually disintegrated . Under the influence of MBAA, after break-down of the membrane of pinocytic vesicles a swollen part of the virus core remained in cytoplasm . The morphologically visible replication stages were completely blocked by MBAA . From these results it was concluded that the antiviral action of MBAA most probably depends on a block of virus replication between the final stages of the penetration process and the beginning of production of virus specific structural antigens.

J Med Virol, 1978, 3(2), 157 - 64
Biological activity of hepatitis B antigens in cell culture; Brumpt I et al.; Direct interference by purified hepatitis B surface antigen or virus particles was not demonstrated in tissue culture . Significant levels of interferon were not induced . The surface antigen did not block the adsorption of other viruses.

Am J Med Genet, 1978, 2(3), 253 - 66
Mosaicism in amniotic fluid cell cultures: classification and significance; Hoehn H et al.; The last decade has witnessed increasing application of human cytogenetic technology to prenatal chromosome analysis . However, unlike the rather uniform peripheral blood T-lymphocyte system which has provided most of our experience in human cytogenetics, long-term amniotic-fluid cell cultures display extreme cellular heterogeneity and disproportionate growth of certain cell types as a consequence of clonal amplification . When they enter cell culture, many of these cells are approaching the terminal stages of their respective, life spans and may have accumulated chromosomal aberrations . Concern about the possibility of true fetal mosaicism seems warranted chiefly in situations were multiple colonies display potentially viable aberrations . Clonal analysis, preferably of multiple clonal types, and attention to details of clonal morphology are likely to minimize diagnostic errors and undue apprehension resulting from mosaicism in amniotic-fluid cell cultures.

Urol Int, 1978, 33(4), 205 - 12
{Cell cultures as vitality test for preservation of kidneys by deep freezing (author's transl)}; Kraushaar J et al.; Cytologic examinations of kidneys, which were frozen for preservation in a nitrogen atmosphere below 3 ata, show a considerable damage of the cells . This does not only occur by significant reduction in the amount of isolated cells, but also in the loss of the ability to form cell colonies . DNA measurements show, however, that after 3--4 days the DNA amounts in surviving cells are intact . In one of the cultures we even found DNA values, which stand for a DNA synthesis . Experiments with mechanical perfusion alone show that this procedure results in a severe damage of the cells, only about one-third of these cells being able to form colonies.

Intervirology, 1978, 9(6), 359 - 61
Isolation of field rabies virus strains in CER and murine neuroblastoma cell cultures; Smith AL et al.; Infection of CER and murine neuroblastoma (clone N18) cell cultures by inoculation of brain tissue from rabid skunks, dogs, equines, foxes, bats and cows was detected by immunofluorescence 2--5 days after inoculation.

J Clin Pathol, 1978 Jan, 31(1), 1 - 11
Use of cell cultures as an indicator of pathogenicity of free-living amoebae; Cursons RT et al.; Results comparing the time needed for the development of cytopathic effects in cell cultures with that needed to cause death in mice using inocula of Naegleria and Acanthamoeba are presented . The significance of the source and concentration of the inocula is demonstrated . The use of cell cultures as an indicator of the pathogenicity of free-living amoebae is discussed.

Immunology, 1978 Jan, 34(1), 137 - 47
Isolation and partial characterization of an antibody enhancing factor from leukaemic owl monkey cell cultures; MacDonald AB et al.; Herpesvirus saimiri inoculated into owl monkeys (Aotus trivirgatus) causes leukaemia and lymphoma . Peripheral lymphocytes from leukaemic monkeys grown in culture are predominantly T lymphocytes . The supernatants from these cultures contain a factor which enhances the antibody response of murine B cells to sheep red blood cells (SRBC) . The factor has been partially characterized by ammonium sulphate precipitation, DEAE-chromatography, gel filtration over Sephadex G-150 and disc-gel electrophoresis . The enhancing factor is a protein with a molecular weight of approximately 40,000.

Antibiotiki, 1978 Jan, 23(1), 43 - 5
{Biological properties of L-asparaginase preparations from E . coli in cell cultures}; Kondrat'eva NA et al.; Non-specific cytotoxicity and specific antitumor activity of 5 preparations of L-asparaginase from E . coli were studied . Two cell line, i.e . the asparagine-dependent (Berkitt lymphoma cells) and asparagin-independent (human ovary cancer cells) were used as the test-system . Incorporation of 3H-thimidine into DNA was the criterion of the preparation effect on the cells . Preparation I with the specific activity of 60-90 IU per 1 mg of protein obtained at the first stages of purification had high non-specific cytotoxicity . Preparation II obtained after further purification of preparation I, as well as preparation II without any stabilizer with the specific activity of 200 IU/mg were not inferior to the "Bayer" preparation by their biological properties . Addition of L-asparaginase to the preparation as a stabilizer of excessive glycine (preparation IV) increased its non-specific cytotoxicity and interfered with the study of its properties in the cell systems . Mannitol (preparation V) had no effect on the biological activity of L-asparaginase preparation.

Exp Cell Biol, 1978, 46(1-2), 1 - 10
Determination of thymidine in serum used for cell culture media; Schaer JC et al.; Thymidine concentrations in serum used for cell culture media were determined with an assay based on isotope dilution . In this assay, incorporation of (3H)-thymidine into DNA of cultured cells was measured in the presence of 5 and 20% serum as a function of the concentration of unlabeled thymidine added to the medium . In three batches of horse serum, thymidine concentrations were 0--0.17 micron, while in fetal calf serum values of 0.75--2.1 micron were obtained . Dialysis of serum resulted in a reduction of thymidine levels by factors of at least 10.

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