J Cell Biol, 1982 Apr, 93(1), 1 - 4 Epidermal growth factor inhibits growth of A431 human epidermoid carcinoma in serum-free cell culture; Barnes DW; A medium consisting of a rich basal nutrient mixture supplemented with bovine insulin (10 micrograms/ml), human transferrin (10 micrograms/ml), human cold-insoluble globulin (5 micrograms/ml), and ethanolamine (0.5 mM) supported the growth of the A431 human epidermoid cell line in the absence of serum with a generation time equal to that of cells in serum-containing medium . Addition of epidermal growth factor (EGF) to this culture medium at concentration mitogenic for other cell types resulted in a marked inhibition of A431 cell growth . Inhibitory effects of EGF were observed at 1 ng/ml and near-maximal effects were observed at 10 ng/ml . The inhibitory effect of EGF could be reversed by the omission of EGF in subsequent medium changes and could be prevented by the addition of anti-EGF antibody to the culture medium . Inhibition of A431 cell growth by EGF also could be demonstrated in serum-containing medium. In Vitro, 1982 Apr, 18(4), 377 - 81 Monoclonal antibodies specific for cell culture mycoplasmas; Buck DW et al.; Mycoplasma infection of cell cultures is still a major problem in some laboratories . Although several methods can be used for their detection, identification is normally by serological procedures . As no commercial source for the necessary antibodies is available we have prepared monoclonal antibodies to the five mycoplasma species that account for the majority of cell culture infections . These antibodies have been characterized by the growth inhibition test (GIT), immunofluorescence, and enzyme linked immunosorbent assay (ELISA) and have shown perfect correlation in all tests when compared to conventional antisera raised in rabbits or donkeys . In addition, a monoclonal antibody to Mycoplasma pneumoniae was produced . M . pneumoniae is an infrequent cell culture contaminant but is a human pathogen, and the monoclonal antibody described here could be useful in the clinical diagnosis of M . pneumoniae infection in man. Eur J Clin Invest, 1982 Apr, 12(2), 145 - 9 Alkaline phosphatase and acid lysosomal hydrolases in pancreatic juice and fibroblast cell cultures of patients with chronic calcifying pancreatitis; Figarella C et al.; Nine lysosomal enzymes and alkaline phosphatase have been assayed in human pancreatic juice from controls and patients with chronic calcifying pancreatitis . Specific activities were evaluated by a nonparametric test (Wilcoxon) with a probability of 2 P less than or equal to 0.5 . The values of acid phosphatase, alpha-glucosidase, beta-glucosidase and alpha-galactosidase are significantly higher in pathological juices; the values of alpha-mannosidase and beta-glucuronidase are also increased in the same patients but at the limit of significance . Alkaline phosphatase, beta-hexosaminidase and alpha-fucosidase follows the same trend but the values are not statistically significant between the two groups of patients . Studies on skin cultures of four patients with chronic calcifying pancreatitis demonstrate that the increased specific activities of lysosomal enzymes in the pathological juices do not correspond to a leakage of these enzymes into the extracellular space as described for cystic fibrosis. Can J Comp Med, 1982 Apr, 46(2), 186 - 9 Sensitivity of seven different types of cell cultures to three serotypes of foot-and-mouth disease virus; House JA et al.; The ability of bovine tongue origin foot-and-mouth disease virus serotypes A, O and C to replicate in seven different types of cell cultures was studied . Primary and secondary calf thyroid cells were equivalent in susceptibility to bovine kidney cell cultures passaged up to five times . Calf thyroid cells lost their susceptibility after two passages . Cryopreserved bovine kidney cell cultures passaged three and four times were equivalent in susceptibility to sensitive calf thyroid and bovine kidney cells . Susceptibility to foot-and-mouth disease virus serotype C was most variable among the cells tested . Lamb testicle and porcine kidney cells were susceptible to foot-and-mouth disease virus while goat and calf testicle and calf lung cells were refractory. Mol Cell Endocrinol, 1982 Apr, 26(1-2), 151 - 64 Gonadal steroid modulation of LHRH-stimulated LH secretion by pituitary cell cultures; Kamel F et al.; Enzymatically dispersed rat pituitary cells were grown in primary culture, and LHRH-stimulated LH secretion was measured . Testosterone (T) decreased and 17 beta-estradiol (E) increased pituitary responsiveness to LHRH . The effect of E on LH secretion was partly due to an increase in LH content . There was a latent period of 12 h for E and 18 h for T between the onset of steroid treatment and the manifestation of steroid action . Neither steroid was required to be continuously present in order to exert its effects . After steroid withdrawal, the effect of T persisted for 72 h and that of E for more than 96 h . The actions of both steroids were blocked by protein-synthesis inhibitors . These results are consistent with the hypothesis that steroid effects rely on a mechanism involving alterations in protein synthesis; the affected proteins may be involved in the process of LHRH action. Am J Vet Res, 1982 Apr, 43(4), 708 - 10 Comparison of a direct radioimmunoassay with virus isolation in cell culture for detection of pseudorabies virus in tissues of infected swine; Neill JD et al.; A direct radioimmunoassay (DRIA) was developed for detection of pseudorabies virus (PRV) in tissues of pigs with clinical disease . Homogenates of tissues prepared from 289 swine were tested for PRV with the DRIA and virus-isolation technique (VIT) . The virus was detected in 53 (18%) of the homogenates by both DRIA and VIT . Fifteen (5%) others were positive for PRV by VIT, but negative by DRIA . There were no samples negative by VIT and positive by DRIA . A total of 221 (77%) pigs with clinical PRV infection were negative in both DRIA and VIT . Although the VIT is more sensitive than DRIA, the DRIA possesses certain advantages which include reduced requirement for aseptic procedures and cell cultures, rapidity, and increased objectivity . Moreover, high levels of confidence could be attributed to DRIA-positive results, since DRIA-positive/VIT-negative results were not obtained. Antimicrob Agents Chemother, 1982 Apr, 21(4), 634 - 40 Alpha interferon and acyclovir treatment of herpes simplex virus in lymphoid cell cultures; Hammer SM et al.; The T-lymphoblastoid cell line CEM, persistently infected with herpes simplex virus type 1, has been used to examine the antiviral efficacy of human alpha interferon and acyclovir, both alone and in combination . Acyclovir and interferon each produced dose-dependent decreases in virus titer at concentration ranges of 1 to 100 microM (approximately 0.225 to 22.5 micrograms/ml) and 10 to 10,000 U/Ml, respectively . Mean reductions in titer of 1.9 and 4.2 log10 PFU/ml were observed with 100 microM acyclovir and 10,000 U of interferon per ml, respectively, on day 10 of treatment . The combination of 100 microM acyclovir and 10,000 U of interferon per ml produced the most rapid fall in virus titer of all regimens examined and elimination of infections virus by day 7 . Prolonged treatment (greater than 10 days) with acyclovir or alpha interferon was accompanied by a gradual return of virus titer to control levels despite the continuous presence of drug . Virus preparations isolated from such cultures were tested for antiviral agent sensitivity by a plaque reduction method . Acyclovir-exposed isolates were found to be acyclovir resistant, with 50% inhibitory doses of greater than 200 microM, and to be thymidine kinase deficient . Alpha interferon-exposed isolates were not interferon resistant . These results suggest that, in persistently herpes simplex virus-infected CEM cells: (i) combination treatment with 100 microM acyclovir and 10,000 U of alpha interferon per ml is more effective in reducing virus titer than either agent alone; (ii) prolonged exposure to drug may result in development of resistance by either the virus strain or the host cell system; and (iii) development of acyclovir resistance by herpes simplex virus in lymphoid cells is mediated by thymidine kinase. Life Sci, 1982 Mar 8, 30(10), 849 - 58 Cerebral endothelial cell culture . I . The presence of beta 2 and alpha 2-adrenergic receptors linked to adenylate cyclase activity; Karnushina IL et al.; Cultured endothelial cells derived from cerebral microvessels separated from 2-day-old rat brain contain a specific beta 2 and alpha 2-adrenergic sensitive adenylate cyclase (AC) . Among the various tested hormones, PGE1 and PGE2 were found to be the most potent activators, while adenosine, angiotensin I and II, gamma-aminobutyric acid and vasoactive intestinal peptide inhibited the enzyme activity . However, acetylcholine, histamine, serotonin, glycine, glutamine, bradykinin, neurotensin and vasopressin (Lysine and Arginine) had no effect on the adenylate cyclase activity in this model . The susceptibility of the cerebrovascular endothelial AC system to the vasoactive substances as well as presence of beta 2 and alpha 2-type adrenergic receptors in the cultured endothelium provides additional support for the proposed endothelial involvement in the regulation of cerebrovascular permeability and blood flow. Neurochem Res, 1982 Mar, 7(3), 301 - 16 Possible role of sialocompounds in the uptake of choline into synaptosomes and nerve cell cultures; Massarelli R et al.; Incubation of primary nerve cell cultures and of crude synaptosomal preparations with neuraminidase released sialic acid from both gangliosides and sialoglycoproteins . After this treatment, the pattern of ganglioside distribution was severely modified with a decrease of polysialogangliosides (GD1b, GT1b, Gt1L, GQ1) and a dramatic increase in monosialoganglioside GM1 . The choline influx into neuraminidase treated cells and organelles was reduced by 30--50% but the efflux was unmodified . In particular the high affinity mechanism of choline uptake disappeared and the low affinity mechanism was modified in both cases . The disappearance of the high affinity uptake mechanism was not followed by a decreased acetylcholine synthesis as it should be if the current theories on choline uptake and acetylcholine synthesis are correct . Our present data thus confirm our previous hypothesis that choline metabolism regulates choline uptake rather than the other way round as is suggested by the theories most widely accepted at present . Choline uptake was unaffected by pretreatment of cells and organelles with tetanus toxin suggesting that the effect of neuraminidase on the choline uptake were either mediated through glycoproteins or through gangliosides other than those which bind to tetanus toxin (GD1b and GT1b) . Several speculative models for explaining the effect of neuraminidase on choline uptake are proposed. J Physiol, 1982 Mar, 324, 441 - 51 Influences on the expression of acetylcholine receptors on rat nodose neurones in cell culture; Baccaglini PI et al.; 1 . Nodose neurones dissociated from new-born rats were grown in culture in the absence or presence of cells from neonatal skeletal muscle or heart . 2 . In cultures devoid of non-neuronal cells cholinergic interactions between the neurones were common . In the presence of non-neuronal cells such interactions were rare . 3 . A decrease in the proportion of neurones responsive to ACh was primarily responsible for the reduced incidence of synaptic interactions . Non-neuronal cells influenced the expression of ACh receptors in developing nodose neurones in culture . 4 . Most neurones appeared susceptible to the non-neuronal influence during the first week in culture . 5 . Many nodose ganglion neurones, whether grown in the presence or absence of non-neuronal cells, were sensitive to gamma-aminobutyric acid and serotonin but were insensitive to glutamate, glycine and L-epinephrine. Scand J Haematol, 1982 Mar, 28(3), 227 - 32 Cellular proliferation and susceptibility to iron toxicity in iron loaded cell cultures; Williams A et al.; Chang cells from human liver, grown in a medium supplemented with 161 mumol/l ferric nitrilotriacetate become iron loaded with an increase in their ferritin content and total iron content . Their viability is not impaired and they survive indefinitely in this state when subcultured at regular intervals . When the cells are grown in a confluent culture their mitotic index is reduced from 12% to less than 1% . In this state they survive normally in unsupplemented medium but when iron is added at 161 mumol/l concentration the cells die within 6 weeks . The toxic lesion appears to be induced within three weeks and is irreversible unless the cells are transferred to an iron-poor medium . Cultural conditions, particularly proliferative rate, appear to be important in determining susceptibility of the cells to iron toxicity . Cell age, hypopoxia and lysosomal enzyme have been assessed as factors that may affect susceptibility. Cardiovasc Res, 1982 Mar, 16(3), 138 - 43 Anoxia-induced changes in composition and permeability of sarcolemmal membranes in rat heart cell cultures; Altona JC et al.; The effects of energy-deprivation on composition and permeability of the sarcolemmal membrane of cardiac cells was studied using monolayer cultures of neonatal rat heart cells incubated in the absence of oxygen and metabolic substrates for 0 to 10 h at 37 degrees C . In the course of anoxia the cells were analysed for cholesterol content, a sarcolemmal sterol, and L-leucyl-naphthylamidase (LNA) activity, a sarcolemmal protein . In addition, sarcolemmal permeability was studied by measuring the efflux of alpha-hydroxybutyrate dehydrogenase (HBDH) activity from the incubated cells . To test whether cholesterol and LNA are indeed markers of sarcolemmal membrane of the heart cells used, sarcolemmal preparations were obtained using an isolation method with cation-coated beads . The results of this study indicate that during anoxia and substrate depletion, changes in sarcolemmal cholesterol content precede sarcolemmal LNA liberation and cytoplasmic HBDH release . It is concluded that energy-deprivation in cardiac cells destroys sarcolemmal structure and function, secondary to the loss of cholesterol. Infect Immun, 1982 Mar, 35(3), 1139 - 41 Cytopathogenicity of Naegleria gruberi for rat neuroblastoma cell cultures; Marciano-Cabral FM et al.; Amoebae of Naegleria gruberi were cytopathic for cultures of rat neuroblastoma (B-103) cells . N . gruberi grew and destroyed B-103 cells at 30 degrees C . As few as one amoeba inoculated per million B-103 cells resulted in cytopathogenicity after extensive growth of N . gruberi. Cancer Res, 1982 Mar, 42(3), 1008 - 14 Quantitative dose-response relations for the cytotoxic activity of chloroethylnitrosoureas in cell culture; Weinkam RJ et al.; A dose-response relation for the cytotoxic activity of chloroethylnitrosourea cancer chemotherapeutic agents in cell culture has been developed . Data for the activity of 1,3-bis(2-chloroethyl)-1-nitrosourea, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea, 1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea, and 1-(2-chloroethyl)-3-(piperidine-3,6-dion-3-yl)-1-nitrosourea against 9L rat brain tumor cells are presented . Cytotoxicity resulting from treatment schedules at different initial drug concentrations, exposure periods, and preincubation periods are correlated using a proposed dose function . Equations are presented that incorporate drug concentration, duration of exposure of cells, and the rate constant for conversion of the drug from an active intermediate into a single dose function . When compared in this way, all cell treatment schedules used were found to be equally effective in killing cells in culture . The cytotoxic activity of the four different chloroethyl-nitrosourea analogs were also found to be the same . These data demonstrate the application of quantitative dose-response relations to the activity of chloroethylnitrosoureas in cell culture and provide new insight into the mechanism of action and structure-activity relationships of these compounds. J Urol, 1982 Mar, 127(3), 585 - 8 Cell culture of Peyronie's disease plaque and normal penile tissue; Somers KD et al.; Cell cultures derived from Peyronie's disease plaque and normal penile tissue were characterized morphologically and examined by immunofluorescence for actin cable formation, and their growth properties were compared . Relative to normal penile cell cultures which grew as contact inhibited, poorly refractile fibroblast-like cells, plaque derived cell cultures consisted of round and spindle shaped cells that were more refractile and exhibited random crisscross growth patterns . Scanning electron microscopy of plaque derived cell cultures revealed changes in cell surface topography characterized by the appearance of surface membrane blebs amd microvilli . Transmission electron microscopy demonstrated cells containing organized cytoplasmic microfilament bundles and nuclear indentations which resembled myofibroblasts . Such alterations were less extensive or absent in normal penile cell cultures . The amount and extent of actin cable formation was increased in plaque derived compared to normal penile cell cultures . Plaque derived cells also exhibited differences in growth properties and grew to higher saturation densities than their normal counterparts . These results demonstrate that cells derived from Peyronie's disease plaque can be grown in vitro and that these cells are morphologically altered and have an enhanced proliferative capacity . The availability of these cell cultures will permit studies directed at understanding the etiology and pathogenesis of Peyronie's disease. Histochem J, 1982 Mar, 14(2), 221 - 37 Stimulated murine peritoneal macrophages in suspension and cell culture: enzyme determinations by biochemical and histochemical means; Wachsmuth ED et al.; Peritoneal exudate cells of mice were studied up to 4 days after i.p . injection of thioglycollate broth medium by means of conventional enzyme determinations and quantitative histochemical measurements of individual cells . Cells from the peritoneal cavity were either investigated immediately after harvesting or after culturing periods of up to six days for enzymic activities of aminopeptidase, esterase, lactate dehydrogenase and beta-galactosidase . A fairly good correlation exists between biochemical determinations of aminopeptidase and esterase activity and the mean of histochemical data . Following a sharp increase in the number of cells after stimulation, aminopeptidase, esterase and lactate dehydrogenase activities per cell were found to be increased . Moreover, the cells taken three or five days after simulation synthesized large amounts of aminopeptidase and esterase as shown by culturing experiments . This capacity of the cells was subsequently lost in cells harvested seven days after stimulation but beta-galactosidase increased and lactae dehydrogenase was more readily released into culture supernatants . The increase in aminopeptidase and esterase was dependent on protein synthesis since it was abolished by cycloheximide . Thioglycollate broth medium provokes immigration of cells into the peritoneal cavity where cells apparently differentiate by increasing their aminopeptidase and esterase concentrations, and by raising their intracellular catabolism rates, which leads eventually to the decay of the cells . The different enzymic phenotypes and the large heterogeneity at any time point after stimulation presumably also reflect different functional properties during the inflammatory process. J Physiol, 1982 Mar, 324, 429 - 39 Electrophysiological studies of new-born rat nodose neurones in cell culture; Baccaglini PI et al.; 1 . Neurones of the nodose ganglion of the vagus nerve were dissociated from new-born rats and grown in the virtual absence of non-neuronal cells and in the presence of nerve growth factor . 2 . The resting potentials of the neurones ranged from -40 to -80 mV . Action potentials were of short duration, with no inflexion on the falling phase; others were of longer duration with a hump on the falling phase . 3 . The inward current of the action potential was carried either predominantly by Na+ or by Na+ and Ca2+ . 4 . Tetrodotoxin (1 microM) blocked the Na+ channels of some neurones but in other neurones the Na+ channels were partially or completely resistant to tetrodotoxin (1-10 microM) . 5 . Many neurones formed excitatory synapses on neighbouring neurones which were blocked or greatly reduced by conventional ganglionic nicotinic antagonists . This indicates that these neurones secreted ACh and expressed ACh receptors at these synapses . 6 . The accompanying paper (Baccaglini & Cooper, 1981) reports the effect of co-culturing nodose neurones with non-neuronal cells on the expression of functional nicotinic receptors. Vopr Virusol, 1982 Mar-Apr, 27(2), 199 - 203 {Use of a cocultivation method for detecting cytomegalovirus contamination of cell cultures of simian origin}; Karetnyi IuV et al.; At present, nonanthropoid primates are widely used as sources of cell cultures for manufacture of live viral vaccines . Simian cell cultures, particularly kidney cell cultures are also known to be frequently contaminated with cytomegaloviruses . The isolation of the latter is rather difficult due to the late appearance of the cytopathic effect in cell cultures of natural hosts . In the present study, the sensitivity of 4 methods virus isolation from the test cells was compared: the method of long-term cultivation of cells; the method of long-term cultivation with one subpassage of the cells; the method of cocultivation of the test cells by mixing with sensitive cells; and the method of co-cultivation by overlaying the test cells on an incomplete monolayer of sensitive cells . The latter method shortened the observation period and yielded a higher percentage of isolation of contaminating viruses from African green monkey kidney cell cultures . This method is supposed to be used in future for the detection of viral contamination of African group monkey kidney cell cultures utilized in manufacture of live viral vaccines. Vet Parasitol, 1982 Mar, 10(1), 29 - 40 Antigenic and immunogenic studies on cell culture-derived Babesia canis; Molinar E et al.; Babesia canis antigens derived from cell culture reacted specifically with immune serum from dogs convalescing from babesiosis . The antigens were heterogenous as compared to antigens elaborated in vivo . The major antigenic moiety from cell culture eluted in the first peak of Sephadex G-200 is indicative of a molecular weight around 900 000 . In contrast, in vivo-derived antigen coeluted with albumin and hemoglobin suggesting a molecular weight of 67 000 . The major antigenic mass is proteinacious and contains disulfide bonds as indicated by thermolability and sensitivity to 2-mercaptoethanol . Both particulate and soluble B . canis antigens were immunogenic, particularly when emulsified in Saponin as an adjuvant . Such antigens conferred a considerable degree of protection in Saponin as an adjuvant . Such antigens conferred a considerable degree of protection in susceptible dogs and it suggested that immunoprophylaxis to B . canis may be feasible. Vopr Virusol, 1982 Mar-Apr, 27(2), 228 - 30 {Sensitivity of a continuous cell culture of human ovarian carcinoma to interferon preparations of different origins}; Timofeev IV et al.; A comparative study of homologous (human) and heterologous (porcine and bovine) leukocyte interferon preparations showed them to have antiviral and antiproliferative effects on CaOv tumor cells culture derived from human ovary carcinoma . These effects were lower in heterologous than in homologous interferon preparations. Mol Cell Biochem, 1982 Feb 19, 42(3), 155 - 60 Influence of estradiol on the total uptake and incorporation of thymidine in human breast cancer (MCF-7) in long-term cell culture . Comparison of autoradiographic and biochemical methods; Coosen R et al.; The total uptake and incorporation into DNA of 3H-thymidine in MCF-7 cells is stimulated by estradiol after an incubation period of 24 h . Prolonged incubations show a decreased rate of both uptake and incorporation of 3H-thymidine, but the labeling index remains elevated up to 48 h . It appears that this is the only exception to the observed good relationship between labeling index and total uptake of 3H-thymidine . This correlation may be of use in comparing autoradiographic and biochemical data on DNA synthesis in the case of culturing both primary mammary tumors and mammary cancer cell lines. Tsitologiia, 1982 Feb, 24(2), 137 - 43 {Fibrillar centers in the nucleoli of a PEK cell culture after administration of actinomycin D}; Chelidze PV; A study was made of the fine structure of the light zone (fibrillar centres) that appear in the interphase nucleoli of PEK cell culture after the action of actinomycin D . The fibrillar centres contain densely packed homogeneous fibrils whose diameter ranged between 7-10 nm . Analysis of serial sections suggests that fibrillar centres may represent spherical zones within the nucleolus, displaying structural continuity with the intra- or perinucleolar chromatin and the perinucleolar nucleoplasm . The origin and some properties of fibrillar centres are discussed. Brain Res, 1982 Feb, 255(2), 229 - 38 Nerve growth factor (NGF) stimulation of cholinergic telencephalic neurons in aggregating cell cultures; Honegger P et al.; The addition of nerve growth factor (2.5S NGF) to serum-free aggregating cell cultures of fetal rat telencephalon greatly stimulated the developmental increase in choline acetyltransferase activity . Two other neuronal enzymes, acetylcholinesterase and glutamic acid decarboxylase, showed only slightly increased activities after NGF treatment whereas the total protein content of the cultures and the activity of 2',3'- cyclic nucleotide phosphodiesterase remained unchanged . The stimulation of choline acetyltransferase was dependent on the NGF media concentrations, showing a 50% maximum effect (120% increase) at approximately 3 ng/ml (10-10 M 2.5S NGF) . NGF treatments during different culture periods showed that the cholinergic neurons remained responsive for at least 19 days . The continued treatment was the most effective; however, an initial treatment for only 5 days still caused a significant stimulation of choline acetyltransferase on day 19 . The observed stimulation appeared to be specific to NGF . Univalent antibody fragments (Fab) against 2.5S NGF completely abolished the NGF-dependent increase in choline acetyltransferase activity, whereas Fab fragments of control IgG were ineffective . Furthermore, angiotensin II, added in high amounts to the cultures, showed no stimulatory effect . The present results suggest that certain populations of rat brain neurons are responsive to nerve growth factor. J Protozool, 1982 Feb, 29(1), 109 - 13 Separation of individual stages of Trypanosoma cruzi grown in cell culture by continuous free-flow electrophoresis; Murray PK et al.; The separation of extracellular protozoan parasites from host cells based on a difference in surface charge has been described . However, with Trypanosoma cruzi no method exists for the isolation of pure parasite stages from heterogeneous mixtures . Studies on the electrophoresis of mixed stage populations confirm significant surface charge density differences exist among epimastigotes, trypomastigotes, and amastigotes . In ascending order of electronegativity, amastigotes have the lowest charge density, trypomastigotes next, followed by epimastigotes . A technique has been developed for the separation of purified populations of parasites based on these charge differences using a continuous free-flow electrophoresis apparatus . The separated populations are morphologically intact and maintain their infectivity to mice . This separation method is applicable for preparative and analytical isolation of pure stages of T . cruzi for biochemical and immunological studies. Can J Physiol Pharmacol, 1982 Feb, 60(2), 212 - 5 Inhibition of ferrochelatase by N-methylprotoporphyrin IX is not accompanied by delta-aminolevulinic acid synthetase induction in chick embryo liver cell culture; Cole SP et al.; N-Methylprotoporphyrin has been shown to markedly inhibit ferrochelatase activity in chick embryo liver cell culture without inducing delta-aminolevulinic acid (ALA) synthetase activity . This result supports the idea that the effects of 3,5-diethoxycarbonyl-1,4-dihydro-2,4,6-trimethylpyridine (DDC) on ALA synthetase activity and ferrochelatase activity are dissociated and that inhibition of ferrochelatase alone is not sufficient to cause induction of ALA synthetase . We conclude that the porphyrinogenic activity of DDC can be explained only in part by the actions of N-methylprotoporphyrin. Arch Androl, 1982 Feb, 8(1), 29 - 35 Effect of neonatal androgenization on the LHRH response of dispersed pituitary cell cultures; O'Conner JL et al.; To determine if neonatal androgenization affects pituitary luteinizing hormone releasing hormone (LHRH) response, female rats were androgenized 24-48 hr following birth . Intact male and female litter mates were maintained for comparison . At 83 days of age, randomly selected males and androgenized females were gonadectomized . At 90 days of age, pituitary cell cultures were begun . On day 3 the cells were challenged with LHRH . Gonadotropin response was determined by radioimmunoassay (RIA) . Basal gonadotropin release from androgenized female cells was similar to male cells, while the pattern and magnitude of the LHRH response was similar to intact female cells . After castration, the pattern and magnitude of the LHRH response of the androgenized female pituitary was most like the male . Androgenized female cells exhibited mixed male and female LHRH response. Immunology, 1982 Feb, 45(2), 381 - 5 Immunization of mouse spleen cell cultures in the absence of serum and its proteins using SiO2 and 2-mercaptoethanol; Burger M; High recoveries of plaque-forming cells were obtained in a serum-free medium using 2-mercaptoethanol and SiO2 . Under such conditions an increase in the number of plaque-forming cells occurred between the fourth and fifth day of incubation, as compared with cultures with foetal calf serum . The addition of glutathione to the medium had a stimulating effect, it was however not absolutely necessary for a positive response . The recovery of plaque-forming cells was strongly influenced by an interdependence of cell density and amount of SiO2 gel particles. J Neurosci, 1982 Feb, 2(2), 169 - 77 Substance P-like immunoreactivity in neurons in dissociated cell cultures of mammalian spinal cord and dorsal root ganglia; Neale EA et al.; Dissociated cell cultures prepared from fetal mouse spinal cords and dorsal root ganglia were stained for endogenous substance P using the peroxidase-antiperoxidase technique . Substance P-like immunoreactivity was localized within a small percentage of rounded or multipolar neuronal somata and in varicose processes . The substance P-positive multipolar neurons were derived from spinal cord, while the small rounded neurons were possibly of spinal cord and/or sensory ganglion origin . Large dorsal root ganglion neurons were unreactive . These results are consistent with in vivo findings and indicate the feasibility of electrophysiologic studies in culture to analyze the synaptic connections between substance P neurons and their target cells. Biochem Pharmacol, 1982 Jan 15, 31(2), 189 - 93 Dissociation between ornithine decarboxylase activity and aryl hydrocarbon hydroxylase induction in cell cultures treated with benz{a}anthracene and inhibitors of ornithine decarboxylase; Raunio H et al.; The induction of aryl hydrocarbon and ornithine decarboxylase by benz{a}-anthracene in the presence or absence of ornithine decarboxylase inhibitors was studied in three different cell culture systems . An almost complete abolishment of ornithine decarboxylase activity by 1,3-diamino-2-propanol or alpha-difluoremethyl ornithine before the addition of the inducer did not affect appreciably the induction of aryl hydrocarbon hydroxylase by benz{a}anthracene in human embryo, HeLa and Rueber H-II-4-E cells in culture . These results suggest that the induction of aryl hydrocarbon hydroxylase does not require ornithine decarboxylase activity per se and can be expressed in the absence of continuous polyamine synthesis. J Biol Chem, 1982 Jan 10, 257(1), 253 - 9 Effect of p-nitrophenyl-beta-D-xyloside on proteoglycan and glycosaminoglycan biosynthesis in rat serosal mast cell cultures; Stevens RL et al.; Rat serosal mast cells cultured in the presence of heat-inactivated fetal calf serum incorporated (35S) sulfate into heparin proteoglycan of approximately Mr = 750,000 after a 3-h pulse and a 2-h chase . beta-D-Xyloside (0.1 mM) treatments of cultures of rat mast cells resulted in an insignificant increase in total (35S) sulfate incorporation and the appearance of free glycosaminoglycans without a change in proteoglycan size . At higher beta-D-xyloside concentrations, total (35S)sulfate incorporation was inhibited and an increase in the relative glycosaminoglycan content was observed concomitant with a reduction in proteoglycan amount and size . As assessed by susceptibility to digestion by chondroitinase ABC, hydrolysis by nitrous acid, {3H}hexosamine content, and electrophoretic mobility, only heparin chains were polymerized onto the proteoglycan core in all cultures . In contrast, individual glycosaminoglycans which appeared only after beta-D-xyloside treatment were predominantly chondroitin sulfate rather than heparin, indicating that the beta-D-xyloside acceptor supported polymerization of chondroitin sulfate but not of heparin glycosaminoglycan . Thus, the peptide core is an important determinant for the synthesis of heparin glycosaminoglycan by rat peritoneal mast cells. EMBO J, 1982, 1(7), 805 - 10 Shape and assembly of type IV procollagen obtained from cell culture; Oberbaumer I et al.; Type IV procollagen was isolated from the culture medium of the teratocarcinoma cell line PYS-2 by affinity chromatography on heparin-Sepharose . Immunological studies showed that type IV procollagen is composed of pro-alpha 1(IV) and pro-alpha 2(IV) chains and contains two potential cross-linking sites which are located in the short triple-helical 7S domain and the globular domain NC1 . The 7S domain was also identified as the heparin binding site . Rotary shadowing visualized type IV procollagen as a single triple-helical rod (length 388 nm) with a globule at one end . Some of the procollagen in the medium, however, had formed aggregates by alignment of 2-4 molecules along their 7S domains . After deposition in the cell matrix, non-reducible cross-links between the 7S domains are formed while the globules of two procollagen molecules connect to each other . The latter may require a slight proteolytic processing of the globular domains NC1 . The shape of type IV procollagen and the initial steps in its assembly are compatible with a recently proposed network of type IV collagen molecules in basement membranes . Since both type IV collagen and laminin bind to heparin, the formation of higher ordered structures by interaction of both proteins with heparan-sulfate proteoglycan may occur in situ. J Membr Biol, 1982, 70(3), 191 - 8 Transepithelial transport in cell culture: stoichiometry of Na/phlorizin binding and Na/D-glucose cotransport . A two-step, two sodium model of binding and translocation; Misfeldt DS et al.; The renal cell line LLC-PK1 cultured on a membrane filter forms a functional epithelial tissue . This homogeneous cell population exhibits rheogenic Na-dependent D-glucose coupled transport . The short-circuit current (Isc) was accounted for by net apical-to-basolateral D-glucose coupled Na flux, which was 0.53 +/- 0.09(8) mueq cm-2hr-1, and Isc, 0.50 +/- 0.50(8) mueq cm-2hr-1 . A linear plot of concurrent net Na vs . net D-glucose apical-to-basolateral fluxes a gave a regression coefficient of 2.08 . As support for a 2:1 transepithelial stoichiometry, sodium was added in the presence of D-glucose and the response of Isc analyzed by a Hill plot . A slope of 2.08 +/- 0.06(5) was obtained confirming a requirement of 2 Na for 1 D-glucose coupled transport . A Hill plot of Isc increase to added D-glucose in the presence of Na gave a slope of 1.02 +/- 0.02(5) . A direct determination of the initial rates of Na and D-glucose translocation across the apical membrane using phlorizin, a nontransported glycoside competitive inhibitor to identify the specific coupled uptake, gave a stoichiometry of 2.2 . A coupling ratio of 2 for Na, D-glucose uptake, doubles the potential energy available for Na-gradient coupled D-glucose transport . In contrast to coupled uptake, the stoichiometry for Na-dependent-phlorizin binding was 1.1 +/- 0.1(8) from Hill plot analyses of Na-dependent-phlorizin binding as a function of {Na}.(ABSTRACT TRUNCATED AT 250 WORDS) Haematologia (Budap), 1982, 15(3), 303 - 10 Stimulatory effect of blood platelet factor(s) on glycolysis in cell cultures; Tomasiak A et al.; The addition of bovine blood platelet homogenate to confluent cultures of three established mouse cell lines (L-929, Balb c/3T3 and SC) brings about a rapid increase of lactic acid formation . Homogenates prepared from quiescent cells previously treated with platelet breakdown products show an increased rate of glycolysis as compared with homogenates of nonstimulated cell cultures . Activities of hexokinase, pyruvate kinase and lactate dehydrogenase remained unaltered but the activity of phosphofructokinase increased by about 60 per cent . Transport of 2-deoxy-D-glucose into the cells was slightly stimulated . It is concluded that the transport of glucose was not a limiting factor in confluent 3T3 cells . The findings suggest that the increase of phosphofructokinase activity may have accounted for the changes in glycolysis seen in intact cells and cell-free homogenates prepared from cultures exposed to some unknown factor(s) present in platelet homogenate. Acta Microbiol Acad Sci Hung, 1982, 29(3), 201 - 8 Lymphocytic choriomeningitis (LCM) virus carrier cell cultures in Hungarian laboratories; Simon M et al.; One of the HEp-2 sublines maintained in the authors' laboratory was found to carry LCM virus . The virus proved to be identical with the prototype strain LCM-Am except that its multiplication rate in cell cultures and its mouse pathogenicity were limited . Forty-six cell cultures maintained in 10 Hungarian laboratories were examined for LCM carriership . Sixteen cultures including 11 HEp-2 sublines, all originating from a culture brought into Hungary in 1959, proved to carry the virus . Three FL sublines maintained in two laboratories and two sublines, viz . an RK-13 and a HeLa, maintained in a third one, were also contaminated by LCM virus . In these cases, the carrier HEp-2 subline was the probable source of infection and virus transmission is thought to have occurred in the course of manipulation with cell cultures . The necessity of introducing strict preventive measures in tissue culture laboratories is emphasized in the interest of the laboratory workers and for obtaining reliable laboratory results. Vet Med Nauki, 1982, 19(8), 3 - 11 {Karyological study of a long-term cell culture of calf kidney}; Ignatova M et al.; Studied was the karyologic type of a long-term calf kidney cell culture . The optimal conditions were found for the preparation of good metaphase plaques of such cell culture, with clearly visible chromosomes . The changes in the chromosomes, setting in at the level of the 1st, 10th, 20th, and 27th passage were followed up . While the chromosomes in the first passage did not show any visible changes (with the exception of the 3rd chromosome where the presence of satelites was found), these underwent structural changes that started in the tenth passage, reached their peak in the twentieth passage, and receded later on . The most frequently encountered structural changes were the isochromosome gaps, dicentric configurations, acentric fragments, and polyploidy that appeared at the level of the 27th passage in four out of the twenty metaphase plaques . Discussed is the importance of the structural changes found. Zentralbl Gynakol, 1982, 104(23), 1503 - 13 {Ultrastructural studies on trophoblast structure using cell culture--a new theory}; Skrzypulec ZA; A new theory is presented in this paper on the morphological capacity of human trophoblasts . A specific method of cell culturing was used to find out that what is called the syncytium of the trophoblast was formed by two types of epithelial cells, those with small and others with big nuclei . The so called syncytial nuclei and nodes, on the other hand, were found to be alien cell colonies originating from Hofbauer cells and with secondary location in villous epithelium . Hofbauer cells, consequently, should be considered as parent cells . All morphologically important cells of placental villi were cultured in vitro and individually assessed . That was the basis for the authors to find answers to new and very important questions regarding the placenta which had been obscure in the past . The socalled syncytium, too, consists of cytotrophoblast. Toxicology, 1982, 25(1), 41 - 5 The maintenance of cytochrome P-450 in liver cell culture: recent studies on P-450 mediated mechanisms of toxicity; Paine AJ et al.; Rat hepatocytes have been cultured under conditions that result in low and high cytochrome P-450 concentrations and then used as a "screening test" to determine the involvement of cytochrome P-450 in toxicity . The results show that a limitation to the use of cultured hepatocytes in toxicity tests is the lack of extrahepatic release mechanisms of toxic compounds. Vopr Onkol, 1982, 28(11), 53 - 8 {Species and tissue differences of reparative DNA synthesis in embryonic cell cultures treated with carcinogens}; Budunova IV et al.; DNA repair synthesis (RS) was studied in embryonic cell cultures exposed to different carcinogenic factors: UV-light, N-methyl-N-nitro-N-nitrosoguanidine, 4-nitroquinoline-1-oxide, aflatoxin BI and 7,12-dimethylbenz(a)anthracene . DNA RS level was shown to be higher in human liver cells than in murine ones . Tissue-dependent differences in DNA RS of cells damaged by carcinogens were found, too . RS-activity was higher in human, mouse and rat fibroblast cultures than in liver cultures of the same species . RS level in human kidney cultures was similar to that in human fibroblasts . The said differences should be taken into account in the evaluation of the results of testing of chemical agents for carcinogenicity, using their ability to cause DNA repair synthesis. Neuroscience, 1982, 7(8), 1879 - 90 Cerebellar macroneurons in microexplant cell culture: ultrastructural morphology; Neale EA et al.; Microexplant cell cultures of fetal rat cerebellum contain essentially monolayer networks of Purkinje cells, occasional granule cells and neurons from the deep nuclei . The neurons and occasional filament-packed glial cells develop on top of a sheet of flattened, non-neuronal cells . In the absence of extrinsic input to the cerebellum and greatly reduced numbers of granule cells, the Purkinje cells develop a stunted and non-oriented dendritic arbor similar to that observed in agranular cerebella . The Purkinje cell dendritic branches, however, are spine-covered . Although the spines are not enveloped by glia and are only rarely contacted by a presynaptic bouton, most spines display a patch of electron-dense material resembling a postsynaptic membrane specialization . The Purkinje cells develop synaptic interactions among themselves and with granule cells . The ultrastructural morphology of boutons derived from both Purkinje cells and large neurons of the deep nuclei, identified after intracellular injection of horseradish peroxidase, is consistent with that observed in vivo . The present study indicates that cerebellar Purkinje cells survive and differentiate in a culture system in which individual neurons are accessible for electrophysiological and morphological analyses. Jpn J Ophthalmol, 1982, 26(2), 234 - 8 Quantitative cytotoxicity of preservatives evaluated in cell culture with Chang's human conjunctival cells--effect of temperature on cytotoxicity; Takahashi N; Experimental investigations of time-dependent cytotoxicity of preservatives at concentrations commonly used in eyedrops were conducted with Chang's cultured human conjunctival cells exposed to the rest solutions at 4 degrees C, 15 degrees C and 37 degrees C for logarithmic prolonged time in the range of 128 minutes . Cytotoxicity was expressed quantitatively by the exposure time causing 50% cell damage (CDT50) calculated by the Van der Waerden method . Chlorobutanol at 0.2% concentrations showed no cytotoxicity . CDT50 of 0.3% and 0.4% chlorobutanol at 37 degrees C were 30 minutes, 19 seconds and 17 minutes, 47 seconds, respectively, which were more rapid than the estimated CDT50 at 4 degrees C and 15 degrees C . Ethylparaben at 0.05% concentration caused no cell damage . CDT50 of a mixture of 0.2% chlorobutanol and 0.05% ethylparaben was 37 minutes, 38 seconds at 37 degrees C and more rapid than at 4 degrees C and 15 degrees C . CDT50 of 0.007% benzalkonium chloride was 98.9 seconds at 37 degrees C, 94.2 seconds at 15 degrees C and 91 seconds at 4 degrees C. Comp Immunol Microbiol Infect Dis, 1982, 5(1-3), 217 - 26 {Modalities of production and immunity conferred by an inactivated rabies vaccine originating from cell culture}; Precausta P et al.; Further to guidelines advised by the World Health Organization, an inactivated Rabies vaccine was prepared from virus propagated on cell culture . This vaccine is presented either in the freeze-dried form or in the liquid form together with an immunity adjuvant . The specific and nonspecific immunity of the vaccine is excellent . The potency, tested in laboratory animals and in species for which the vaccine is intended, satisfies recommendations published by the W.H.O . The immunity persistence, evaluated by the titration of serum antibodies and by challenge with a pathogenic virus, proves to be excellent 3 years following primovaccination . Finally, the stability of this vaccine is an interesting factor for its application, especially in the form of a combined vaccine. J Cancer Res Clin Oncol, 1982, 103(3), 293 - 304 Ultrastructural, biochemical, and cell-culture studies of a presumed extraskeletal Ewing's sarcoma with special reference to differential diagnosis from neuroblastoma; Berthold F et al.; The history of a 6-year-old girl with a tumor originating from thoracic spine and finally becoming resistant to surgery, radio-, and chemotherapy is reported . Tumor-biopsy material was studied by light and electron microscopy, in cell culture, by acetylcholinesterase ultracytochemistry, and by quantitative catecholamine analysis and this led to the rejection of the initial diagnosis of a neuroblastoma . Light microscopy revealed a uniform population of undifferentiated cells incompletely lobulated by broad fibrovascular septa . Using the electron microscope, cells were characterized by large intracellular pools of glycogen, little cytoplasm with an abundance of free ribosomes and a paucity of organelles . A few cells displayed desmosome-like attachment sites . Staining for specific and unspecific acetylcholinesterase was negative with light and electron microscopy, as were the results of catecholamine histofluorescence using the glyoxylic acid method . The latter result was confirmed by the negative outcome of quantitative analyses of dopamine, noradrenaline, and adrenaline with high pressure liquid chromatography nd electrochemical detection in tissue samples . Tumor cells could easily be maintained in culture for up to 4 weeks . None of a variety of treatments that are known to favor expression of neuronal characteristics in neuroblastoma cells (serum withdrawal, nerve growth factor, dbcAMP, dexamethasone) induced morphological differentiation in cultured tumor cells . On the basis of the clinical history, morphology, and of our experiments with tumor cells, the diagnosis of a so-called extraskeletal Ewing's sarcoma is most likely . Our results strengthen the view that a cell biology approach may be valuable in neuroblastoma differential diagnosis. Environ Mutagen, 1982, 4(4), 421 - 34 Phenotypic expression time of mutagen-induced 6-thioguanine resistance in Chinese hamster ovary cells (CHO/HGPRT system): expression in division-arrested cell cultures; O'Neill JP et al.; The phenotypic expression time of ethyl methanesulfonate (EMS) induced 6-thioguanine-resistant mutants was studied with Chinese hamster ovary cells in culture (CHO/HGPRT system) . After mutagen treatment of exponential phase cultures, the cells were maintained either in the exponential phase through subculture in medium containing 5% dialyzed fetal bovine serum (FBS) or in a nondividing viable state by use of medium containing 0-1% dialyzed FBS . The time course of expression of the 6-thioguanine-resistant phenotype was similar with both exponential phase and division-arrested cultures showing maximum expression by 9 days after mutagen treatment, and both methods of expression also yielded similar mutant frequencies over a range of EMS concentrations . This study shows that once the mutagenic event is fixed, the expression of the mutant phenotype does not require continued cell division since it occurs in division-arrested cultures . These results also suggest that both dilution of pre-existing hypoxanthine-guanine phosphoribosyl transferase (HGPRT) enzyme by cell division and turnover by protein degradation are involved in the phenotypic expression . Both processes occur in exponential cultures, but only protein turnover in arrested cultures . Consistent with this was the demonstration that the rates of total cell protein turnover increased in division-arrested cultures maintained in serum-free medium . These results separate genetic damage and phenotypic expression in a temporal sense, and point out the need to consider the mechanisms responsible for each process involved in the induction and expression of mutations. Vet Med Nauki, 1982, 19(1), 33 - 40 {Comparative study of strains of Newcastle disease virus in cell cultures of chick embryo fibroblast}; Khadzhiev G; Comparative investigations were carried out with local velogenic strains (2 viscerotropic--Haskovo and Bregovo, and neurotropic--Rosa and Toutrakan) and 6 standard strains of the Newcastle disease virus, belonging to various pathogenic groups, in tissue cultures of chick embryo fibroblasts . The four local strains as well as the velogenic one (The . GB) and the mesogenic standard strains (Komarov, Roakin, and Hertfordshire) were reproduced in such cultures, producing a clear cytopathic effect without preliminary adaptation passages . The two strains studied parallel to the others, that were of velogenic pathogenic type (La Sota and Hitchner B1) did not produce cytopathogenic effect, and the cultural liquids did not poses agglutination activity with regard to chicken erythrocytes . The average infection titers in tissue cultures of chick embryo fibroblasts (TCID50) for the particular strains in an experiment varied in a wide range and proved higher with the velogenic (regardless of the fact that they belonged to the viscero- and neurotropic pathogenic type) that with the mesogenic strains . The TCID50/cm3 titer ratio of the strains with regard to their corresponding infection titers in chick embryos (EID50/cm3) also varied in a wide range, but invariably in favour of EID50 . The latter was more strongly expressed for the mesogenic strain than for the velogenic pathotype strain of the Newcastle disease in experimental conditions. Prog Clin Biol Res, 1982, 85 Pt A, 249 - 55 Transdetermination and transdifferentiation of neural retinal cells into lens in cell culture; Okada TS et al.; Two aspects of transdifferentiation of avian neural retina (NR) cells into lens in cell culture were discussed . First, by means of the transfer experiments of NR cells pre-cultivated in spreading cultures (SpC) longer than 10 days into aggregation cultures (AgC), it was shown that NR cells are "transdetermined" into lens direction, before the phenotypic expression of lens in cells at such earlier stages of SpC . In the second part of this article, we showed that NR-cells which have already expressed some neuronal phenotypes can transdifferentiate into lens . This statement is based upon the results of chimeric cultures consisting of neuronal cell fraction separated from 10-day SpC of quail NR and of the epithelial cell fraction of SpC of chick NR . Lens cells formed in such chimeric cultures were mainly of quail origin. J Hyg Epidemiol Microbiol Immunol, 1982, 26(1), 83 - 94 Specific activity of concentrated and purified cell culture rabies vaccine (CPCRV) from the strain Vnukovo -32-107 in an experiment with therapeutical immunization of humans; Selimov M et al.; Reactogenicity and specific activity of three series of concentrated and purified cell culture rabies vaccine (CPCRV) were studied in an experiment of therapeutical immunization of 300 human subjects bitten by domestic animals, category "C" . CPCRV was well tolerated; when administered intramuscularly, it did not provoke local reactions, while general reactions, such as temporary headaches and indisposition, were observed in 4% of cases . Intradermal revaccination with CPCRV was followed by local reactions in 73.6% of cases . Such a reaction can be regarded as a cutaneous allergic test . Coded paired sera of 263 subjects were examined in the neutralization reaction on mice . After primary intramuscular immunization, antibody titres were found to be very low . Relatively high titres of antibodies and 100% seroconversion were recorded after a single intramuscular or intradermal revaccination with CPCRV . Relatively high antibody titres and 100% seroconversion also resulted from treble, and especially quadruple primary intramuscular immunization using a dose of 1.5 ml on days 0, 8, 16, 24 or 0, 8, 16 and 32 . When treating bites of non-dangerous localization, CPCRV can be administered in a dose of 1.5 ml at a time on days 0, 7 15, 30 and 60 (5 injections in total) . The scheme of combined vaccinations using CPCRV and antirabies gamma-globulin requires exploration. Clin Endocrinol (Oxf), 1982 Jan, 16(1), 97 - 100 Histidyl-proline diketopiperazine suppresses prolactin secretion in human pituitary tumour cell cultures; Melmed S et al.; Because histidyl-proline diketopiperazine (HPD), a metabolite of TRH, has been shown to suppress prolactin (PRL) release by rat pituitary tumour cells, human pituitary tumour cells were exposed to this compound . Monolayer cell cultures were initiated from pituitary tissue removed by transsphenoidal surgery from two patients with prolactin-secreting microadenomas . Tumour fragments were mechanically dispersed; cells were seeded into multiwell plates and incubated in Ham's F-10 medium enriched with fetal calf serum (20%) . HPD (7.5 ng/ml) suppressed PRL release by both tumour cell cultures . Theophylline reversed the inhibition of PRL release induced by HPD . The data raise the possibility that HPD may act as an endogenous prolactin-inhibiting factor in man. Ophthalmic Res, 1982, 14(1), 63 - 9 Cytotoxicity of mercurial preservatives in cell culture; Takahashi N; The cytotoxicity of two kinds of mercurial preservatives, thimerosal and phenylmercuric acetate, was studied using Chang's human conjunctival epithelia in cell culture . The cultured cells were exposed for 5 s, 2 min and 24 h to each of the two preservatives at various concentrations, obtained by serial dilution . The cytopathic effect and cell desquamation from the wall of culture flask were observed with an inverted microscope and LD50 was calculated by Van der Waerden's method . The LD50 values of thimerosal were 291.6, 47.4 and 2.2 micrograms/ml at exposure times of 5 s, 2 min and 24 h, respectively . Those of phenylmercuric acetate were 1,120.2, 227.5 and 2.6 microgram/ml at exposure times of 5 s, 2 min and 24 h, respectively . Cytotoxicity can be expressed quantitatively and precisely by LD50 . LD50 is lower than the concentrations that are necessary to induce observable morphological changes . The results may help to choose the least toxic concentration of mercurial preservatives for addition to ophthalmic solutions. J Physiol, 1982 Jan, 322, 83 - 93 Mediation of compensatory renal growth in the rat: cell culture demonstration of a serum factor; Hansen PA; 1 . The participation of a circulating growth factor in the mediation of compensatory renal growth has been hypothesized but not proven . Theoretical considerations predict that in vitro methods could be profitably used to resolve this question, since such methods would allow dissociation of the growth effects of the postulated factor from the complex physiological changes which accompany compensatory renal growth in vivo . 2 . A culture system using epithelial cells obtained from the rat kidney is described which is suitable for testing serum from previously unilaterally nephrectomized or sham-operated rats for the presence of a factor mediating compensatory renal growth . The morphology of the cultured cells is compatible with that of proximal tubule epithelium, this being the cell type stimulated to divide in vivo after unilateral nephrectomy . 3 . Treatment with serum from rats unilaterally nephrectomized 48 h previously results in consistent increase in uptake of tritiated thymidine by cultures, when compared with control serum from sham-operated rats . Serum from rats unilaterally nephrectomized 18--36 h previously is not consistently stimulatory . 4 . There are indications that the differential effect of sera from unilaterally nephrectomized and control animals is due to the presence of a stimulatory factor in the former rather than an inhibitor in the latter . 5 . Use of this culture system has confirmed the existence of a serum factor involved in compensatory renal growth. Vopr Onkol, 1982, 28(3), 52 - 6 {Comparison of the results of gestagen therapy of cancer of the corpus uteri with a preliminary study of tumor cell culture sensitivity to the preparations}; Schindler C et al.; The paper deals with a comparative study on the efficacy of adjuvant gestagen therapy of 61 patients with primary endometrial carcinoma . A control group of 219 patients did not receive hormones . In gestagen group, sensitivity to drugs was determined prior to therapy in 67 cell cultures of carcinoma . This provided a basis for a study of the meaning of a test of sensitivity to drugs which was carried out prior to therapy in order to select a suitable gestagen . Survival (2 years) was significantly higher in the group in which tumor sensitivity to chosen gestagen was determined in cell culture prior to treatment . Due to selection of suitable gestagen before therapy by means of tumors sensitivity test, a more pronounced clinical effect is obtained. Zentralbl Gynakol, 1982, 104(3), 156 - 9 {Studies into dependence of sensitivity of cytostatics on overlap index of ovarian cancer in cell cultures (author's transl)}; Schindler C; Overlap index and cytostatic sensitivity pattern were determined from 66 cell cultures of ovarian carcinoma . The average overlap index of all cell cultures tested was 42.2 per cent +/- 20.5 and proved to be equivalent to that of malignant tumours in different locations . The wide scatter was attributed to the biological individuality of ovarian carcinoma . High overlap indices usually are indicators to high sensitivity to cytostatics, whereas low overlap indices may reflect low sensitivity or even resistance to cytostatic agents . Yet, no high-accuracy prediction can be made for the real individual case . The question is raised, if both parameters are separate and independent indicators to characterise a given tumour or parameters with correlations between them. Med Microbiol Immunol (Berl), 1982, 170(3), 201 - 8 Viral tropisms in mouse brain cell cultures; Beranek CF et al.; Fourteen-day-old cultures of dissociated newborn mouse brain cells were infected separately with different strains of vaccinia virus and a strain of measles virus . Using the indirect immunofluorescence technique we found that under the experimental conditions in these cultures both measles and the neurotropic strain of vaccinia infected oligodendrocytes whereas the dermatropic strain of vaccinia did not . Astrocytes were neither infected by vaccinia strains nor by measles virus. Vet Med Nauki, 1982, 19(10), 18 - 25 {Adaptation of ecthyma contagiosum virus to cell culture}; Traikova M; Series of attempts were made to adapt the Phylaxia vaccinal strain (Hungary) to various cell cultures in vitro . The work with twenty-one successive passages of the virus in a culture of lamb testis resulted in the production of an adapted strain that could produce a characteristic cytopathic effect at the 24th--48th hour of the infection, reaching a titer of 10(4.5) ID/cm3 . Cytologic and electron-microscope investigations confirmed the fact that this cell strain belonged to the Parapoxvirus genus . The experimental infection of 4-5-month-old lambs showed that the virus strain retained its capacity to cause typical clinical signs of infectious ectyma . It could be used in the production of a cell-cultural vaccine. In Vitro, 1982 Jan, 18(1), 35 - 42 Establishment of functional human pituitary tumor cell cultures; Melmed S et al.; Five primary human pituitary tumor cell cultures were initiated from adenoma fragments obtained from patients with prolactin-secreting adenomas and acromegaly . Functional cell cultures were maintained and propagated in monolayer or suspension culture for up to 9 months . Optimal cell viability and growth were achieved using Ham's F10 medium enriched with 20% fetal bovine serum, although cells from a patient with acromegaly also grew in serum-free, defined, hormone-containing medium . Bromocriptine (100 ng/ml) did not alter the growth curve of replicating cells derived from a patient with acromegaly . These cells initially secreted 5.5 micrograms human growth hormone/10(6) cells, and hormone production diminished after 6 wk . Prolactin secretion by cells derived from prolactinomas (0.5 to 1.3 micrograms/10(6) cells/24 h) was stimulated by thyrotropin-releasing hormone (10 ng/ml) in two of the cultures . Both dopamine (10 ng/ml) and nickel chloride (1 mM) suppressed PRL secretion . These studies demonstrate that responsive human pituitary tumor cell cultures can be initiated and maintained. Vet Q, 1982, 4(3), 97 - 100 The influence of various bovine sera on the maintenance of Theileria parva lymphoblastoid cell culture; Siddig HA et al.; Theileria parva infected lymphoblastoid bovine cells were grown in a medium based on HEPES-buffered RPMI 1640 with glutamine and antibiotics, supplemented with bovine serum . There were no significant differences in growth rate, viability, and percentage of infected cells when the substrate contained 10 or 20 per cent of either commercially available newborn calf serum of serum prepared from adult non-infected Friesian cattle or of serum prepared from a Friesian calf immunised against East Coast fever and having a high titre of antibodies to T . parva antigen in the indirect fluorescent antibody test . If studies showing that newborn calf serum gives results in the establishment and maintenance of T . parva cell culture similar to those of foetal calf serum are confirmed, this finding could mean an appreciable saving in the cost of in vitro work on this parasite. Int Arch Allergy Appl Immunol, 1982, 69(2), 143 - 7 LPS-induced enhancement of plaque-forming cell response to bromelain-treated syngeneic erythrocytes in mouse peritoneal cell cultures; Garzelli C et al.; The effect of bacterial lipopolysaccharide (LPS) on the development of plaque-forming cells (PFC) against bromelain-treated syngeneic mouse red blood cells (Br-MRBC) was studied in peritoneal cell (PC) cultures . It was found that LPS enhances the development of PFC to Br-MRBC and increases DNA synthesis in PC cultures . The LPS-induced enhancement of PFC to Br-MRBC, however, does not appear to require cell proliferation, since it also occurred in PC cultures pretreated with mitomycin C . In addition, the LPS-induced B lymphocytes blastogenesis is under the control of macrophages, while cell differentiation of precursor B lymphocytes into cells actively producing antibodies against Br-MRBC is regulated by suppressor T lymphocytes. Infect Immun, 1982 Jan, 35(1), 296 - 304 Cultivation and partial characterization of spiroplasmas in cell cultures; Steiner T et al.; Spiroplasmas were propagated in the Drosophila melanogaster cell line Dm-1 . Spiroplasma citri and unidentified strains (corn shunt organism, 277F {tick isolate}, powder puff, BNR-1, honey bee, and OBMG) grew to 10(8) to 10(9) colony-forming units per ml and could be passaged . Cytopathic effect (CPE) varied with the infecting spiroplasma . The honey bee isolate killed Dm-1 within 2 to 4 days and produced CPE in four mammalian cells tested . At 25 degrees C, suckling mouse cataract agent produced no CPE in Dm-1 cells . Dm-1 cells did not support growth of the spiroplasmal sex ratio organism . Spiroplasmas could be detected in the cell cultures by agar inoculation, dark-field microscopy, scanning electron microscopy, and DNA fluorescent staining . The uridine phosphorylase test showed significant levels of conversion of {14C}uridine to {14C}uracil for all but some plant isolates: S . citri, corn shunt organism, lettuce, cactus, and powder puff strains, the first mycoplasmas to lack the enzyme . Primary isolations of corn shunt organism from infected corn plants were made in Dm-1 and I-XII cultures . The course of corn stunt organism infection of Dm-1 was monitored for three passages . The use of agarose and Dienes staining of the colonies improved growth and colony counting of corn stunt organism . The number of viable infected DM-1 cells decreased from 1.2 x 10(7) at passage 1 to 7.0 x 10(6) at passage 2 and 3 x 10(5) at passage 3. Cell Tissue Res, 1982, 225(3), 581 - 94 Surface labelling of oligodendrocytes with anti-myelin serum in cell cultures from the rat brain . Light- and electron-microscopic immunocytochemical studies; Roussel G et al.; Antiserum produced in rabbits against purified myelin contains antibodies that bind to the surface of cells having multiple branched processes in live cultures of cerebral hemispheres of newborn rats . The identity of these cells was determined by double immunolabelling experiments with other specific antigenic markers (W1 Wolfgram protein, myelin basic proteins, glial fibrillary acidic protein) . It was demonstrated that the cells are a subclass of oligodendrocytes which have reached a certain degree of maturation; nearly all of them contain basic proteins . Indeed, a number of oligodendrocytes, that contain the W1 protein, and may or may not have processes, are not surface-labelled in similar conditions . The usefulness of such an anti-myelin serum in the isolation of pure oligodendrocytes is discussed. EMBO J, 1982, 1(10), 1213 - 6 Expression of hepatitis B surface antigen in unselected cell culture transfected with recircularized HBV DNA; Wang Y et al.; Hepatitis B virus (HBV) DNA was isolated from the recombinant plasmid pA01 -HBV and recircularized . Immediately after introduction of this DNA into mouse fibroblasts (NIH 3T3) we observed increasing release of hepatitis B surface antigen (HBsAg) into the culture medium . Later production of HBsAg declined to a lower but constant level . No dominant selective marker and foreign promoter were necessary in this system, which therefore can be used for the study of regulation of HBsAg expression. In Vitro, 1982 Jan, 18(1), 15 - 23 A gelatin-specific protease from hamster lung-derived cell cultures; Blondin J et al.; Gelatin-specific protease activity from hamster lung fibroblasts and their culture media is described . The fibroblasts were derived from hamster lung explant cultures . The gelatin-specific protease activity is latent and seen only after dialysis of either cells or media . The enzyme activity shares many properties of previously reported gelatinases . The activity is inhibited by EDTA, cysteine, and dithioerythritol, whereas it is not inhibited by p-chloromecuribenzoate, N-ethyl maleimide, or phenylmethylsulfonyl fluoride . Of all substrates tested, activity was observed only against gelatin and not against other substrates tested . It was inactive toward collagen, elastin, and methemoglobin . This enzyme may have a role in the digestion of collagen that has been previously cleaved by mammalian collagenase. Vet Med Nauki, 1982, 19(8), 33 - 9 {Kinetic study of the multiplication of the mucosal disease--viral diarrhea virus in homologous cell cultures}; Petkova K; Comparative studies were carried out on two local cytopathic strains of the virus of mucous disease-viral diarrhoea in primary cell cultures of fetal calf kidney and cell cultures of normal calf kidney in order to ascertain the yield of the virus and the development of a cytopathic effect . It was found that the amount of virus of the strain with strongly manifested cytopathic effect was directly proportional to its activity in the cell cultures of fetal calf kidney . Highest titers of the virus were obtained at the time of full cytopathic effect . In the same cultures the yield of the virus strain with less strongly manifested cytopathic effect was highest prior to the time of its fullest . The kinetics of propagation of the two viruses when culturing in such media proved to be similar to that when normal calf kidney cultures were used, however, the titers of the virus were lower by 1-2 logarithms . Both freezing and thawing of viral suspensions were found to contribute to the release of the virus from the incompletely destroyed cells . The yield of the virus in such cases rose only with the strain with a weak cytopathic effect if the procedure was carried out prior to its full manifestation. Vet Med Nauki, 1982, 19(6), 39 - 48 {Cytological and cytochemical studies of cell cultures infected with the avirulent viral mutant MK 35 of the pseudorabies virus}; Tatarov G et al.; Cytological and cytochemical studies were carried out of cell cultures of chick embryo fibroblasts infected with the vaccinal mutant strain MK 35 (4.8 X 10(7) PFU) of the Pseudorabies virus . It was found that the first cytologic changes in the infected cultures presented definite focal character . In the first hours of infection several rounded cells were included only, while later on an increasing number of cells were involved, and the foci grew in size . The cytoplasma of the infected cells contained inclusions which were small, spherical, basophilic, and Foelgen positive; six hours later the cytoplasmatic inclusions became larger, oval, acidophilic, surrounded by a brighter area, and were Folgen-negative . Parallel to the cytologic changes in the infected cell cultures there set in metabolic disturbances and changes in the enzymatic activity . The infected cells showed enhanced lactate dehydrogenase, diphosphopyridin-nucleotide diaphorase, thiamine pyrophosphatase, and alkaline phosphatase activity and suppressed succinate dehydrogenase and acid phosphatase activity . These studies were said to reveal new biologic properties of the vaccinal mutant virus. Intervirology, 1982, 17(4), 215 - 21 Influence of cell culture conditions on the inhibition of herpes simplex virus type 1 replication by acyclovir; Harmenberg J et al.; Inhibition of herpes simplex virus type 1 (HSV-1) replication, as measured by plaque reduction by acyclovir (ACV), was studied with different cell cultures and under varying conditions . Human lung fibroblasts (HL) required much lower concentrations of ACV for inhibition of virus replication than green monkey kidney (GMK) cells . In both cell types, ACV had to be added within 7 h after infection to cause a full antiviral effect . Pretreatment of cells with ACV before infection did not increase the antiviral activity . ACV caused a stronger inhibition in HL cells which had been confluent for 4 or 7 days as compared with cells just reaching confluence . Addition of ACV and its subsequent removal caused an irreversible plaque reduction in our experiments . ACV gave a pronounced inhibition of thymidine kinase (TK)-positive HSV-1 strains . A relatively small inhibitory effect was seen with a TK-negative HSV-1 strain in HL cells, and no measurable inhibition was seen in GMK cells . Inhibition of HSV-1 replication by ACV was concluded to depend on the type of virus, the cell type used, and the condition of the cells. Acta Radiol Oncol, 1982, 21(2), 133 - 7 Radiation-dose dependence of the formation of micronuclei in misonidazole treated cell cultures; Midander J; The effect of misonidazole at different concentrations on the anoxic radiation sensitivity of Chinese hamster cells was investigated using the frequency of radiation induced micronuclei as criterion . The result indicates that, in a high radiation dose region, sensitization with a dose modifying factor of about 1.9 and 1.3 occurs after treatment with the substance at a concentration of 8 and 0.2 mmol/l, respectively . In a low dose region the corresponding values were 1.7 and 0.8 . It was concluded that high concentration of the substance in combination with high radiation doses are most beneficial. Carcinogenesis, 1982, 3(6), 635 - 9 Benzo{a}pyrene metabolites: formation in rat liver cell-culture lines, binding to macromolecules, and mutagenesis in V79 hamster cells; Selkirk JK et al.; Benzo(a}pyrene was metabolized in liver cell lines derived from BC-IV and BD-IV rats which included several chemically-transformed lines (IAR-6-1; IAR-19; IAR-28), one spontaneous transformant (IAR-27) as well as one non-malignant line (IAR-20) . Cultures were treated with tritiated benzo{a}pyrene over a 5-day period . The cells and medium were extracted with ethyl acetate and the distribution between organic-soluble and water-soluble metabolites determined . Organic-soluble metabolites consisting of dihydrodiols, phenols and quinones were determined by high-pressure liquid chromatography, and macromolecular binding of BP to each cell line was measured over a 24-h period . Comparisons between binding and overall metabolism were not directly proportional in these liver cell lines . However, there was a positive correlation for benzo{a}pyrene mutagenesis in the V-79 hamster cell assay with 8-azaguanine as a marker when the cell lines with the highest (IAR-20) and lowest (IAR-27) metabolic competence were used as activating cell layers. Vet Med Nauki, 1982, 19(1), 21 - 5 {Safety of foot-and-mouth disease vaccines in cell cultures}; Tekerlekov P et al.; Experiments were carried out to test imported and home-produced production and experimental series of foot- and-mouth vaccines in cell cultures . It was found that the primary cell cultures of swine kidney were most appropriate to study the innocuity of the F . M . D . vaccines, which, in terms of sensitivity proved of superior quality as compared to the primary cell cultures of calf kidney and the BHK 21 cells . Comparative investigations have revealed that the most promising method for testing the innocuity of the F . M . D . vaccines is the elution of the antigen from the aluminium hydroxide after Dannacher and coll . The problem is discussed of using cell cultures to check the innocuity of F . M . D . vaccines prior to their release. J Neurochem, 1982 Jan, 38(1), 101 - 11 Development of ion metabolism in reaggregated brain cell cultures; Marks MJ et al.; Mouse brain cell reaggregates have been used to study changes in sodium- and potassium-dependent ouabain-sensitive adenosine phosphohydrolase (Na+, K+-ATPase) activity and in 86Rb+ uptake and exit during development . Na+, K+-ATPase activity in these cultures has two ouabain-inhibitable components, both of which increased severalfold between day 3 and day 17 in culture . This increase, however, was less than that in developing brain . Little change in either total or extracellular water or in the equilibrium levels of Na+ and K+ occurred during development . The uptake of 86Rb+ measured a 10-min incubation showed only a modest increase during culture, whereas the exit of 86Rb+ from reaggregates preloaded with the tracer increased approximately fourfold . The exit consisted of both K+-independent and K+-stimulated components and the K+-stimulated fraction contributed most of the developmental change . When uptake rates were corrected for the contribution of the developmental changes in exit, these rates were found to increase as well . The 86Rb+ uptake correlated closely with the activity of the Na+,K+-ATPase during development . The pattern of developmental changes in enzyme activity and 86Rb+ uptake and exit suggest that, while little change in the steady-state levels of the ions occurred, the rates of ion movement increase markedly. Arch Virol, 1982, 71(3), 267 - 71 Isolation of lapine rotavirus in cell cultures . Brief report; Sato K et al.; Two cytopathic rotavirus strains were isolated in MA 104 cells from diarrheal rabbits . The isolates showed marked cross reactions with strain Lincoln of bovine rotavirus in immunofluorescence, but no cross reaction in neutralization. J Neurosci Res, 1982, 7(2), 111 - 7 Effects of methadone on ornithine decarboxylase and cyclic nucleotide phosphohydrolase in neuronal and glial cell cultures; Vernadakis A et al.; Mixed neuronal and nonneuronal cell cultures were obtained from 8-day-old chick embryos cerebral hemispheres and glial-enriched cultures were obtained from fifteen-day-old chick embryo cerebral hemispheres . Cultures were exposed to methadone, a narcotic drug, from days four to six . The activity of ornithine decarboxylase (ODC) was determined at day eight and the activity of cyclic nucleotide phosphohydrolase (CNP) was determined at day fifteen . Both ODC and CNP activity were higher in mixed neuronal-nonneuronal cell cultures treated with methadone as compared to control . No effect was observed in the neuronal-enriched or glial-enriched cultures . These findings are interpreted to reflect that neuronal-glial interaction is important in the response of primary neural cells to methadone. Avian Dis, 1982 Jan-Mar, 26(1), 182 - 5 A simple technique for preparation of chicken-embryo-skin cell cultures; Silim A et al.; A simple, rapid technique was developed for preparing chicken-embryo-skin cell cultures utilizing trypsinization of the skin of intact 12-day-old chicken embryos . When cell cultures were inoculated with fowl pox virus, those that consisted of at least 80% epithelial cells yielded a higher virus titer than fibroblast cell cultures. J Med Virol, 1982, 9(2), 93 - 100 Early replicative block prevents the efficient growth of fastidious diarrhea- associated adenoviruses in cell culture; Takiff HE et al.; Fastidious enteral adenoviruses (EAds) recovered from infants with diarrhea were studied to determine the basis for their inability to propagate efficiently in conventional cell lines . By immunofluorescence microscopy, only rare EAd-infected KB and HeLa cells were shown to synthesize detectable levels of virion proteins . Sedimentation of Hirt-extracted DNAs in sucrose gradients and DNA hybridization analyses demonstrated that EAd DNA synthesis is highly restricted in HeLa cells . Some early gene functions seem to be expressed, however, because Eads can help adenovirus-associated viruses (AAV) . Thus, EAd replication in conventional cell lines is blocked at an early step in its growth cycle. Arch Virol, 1982, 71(1), 57 - 74 Electron microscopic studies of bovine viral diarrhea virus in tissues of diseased calves and in cell cultures; Bielefeldt Ohmann H et al.; Pathomorphological studies by electron microscopy (EM) were carried out on the intestines and lymphoid tissues, the buffy coat cells and cultured lymphocytes from calves suffering from mucosal disease (MD) . This led to the detection of particles, 45--55 nm in diameter, within characteristic vesicular structures . As these findings coincided with the isolation of bovine viral diarrhea virus (BVDV) from the same tissues and demonstration of BVDV-antigen by immunocytochemical techniques in corresponding samples, the particles were tentatively identified as the BVDV . A detailed study of in vitro infected bovine cell cultures corroborated this supposition and contributed to a conjectural evaluation of the viral morphogenesis . It revealed a difference from the morphogenesis of most other togaviruses, as the presumed virions were assembled within smooth-membraned vesicles, formed during the infection . Thus, in the material examined, a budding process was not involved in the development of BVDV. J Neurosurg, 1982 Jan, 56(1), 62 - 72 Immunological, biochemical, ultrastructural, and electrophysiological characteristics of a human glioblastoma-derived cell culture line; Black PM et al.; This report presents the results of a study using multiple techniques of the established human cell line, LM, which has been developed in culture medium from a patient with a right temporoparietal glioblastoma . This cell line has human subtetraploid karyotype and has several features of a transformed line in culture . These include continuous propagation for 10 years, ability to form tumor nodules when transplanted into immunologically suppressed hamsters, and pleomorphic appearance . Ultrastructurally, it is characterized by multiple nuclei, few actin cables, and numerous surface-membrane microvilli, as well as abundant 9- to 10-nm cytoplasmic filaments . By its immunological reactivity, the line can be shown to contain glial fibrillary acidic protein at low levels, consistent with its glial origin and continued nature . Dibutyryl cyclic adenosine monophosphate (db-cAMP) induces formation of long astrocytic-like processes as well . Its membrane electrical characteristics include a low resting membrane potential and short time constant . Used in a microtiter antiglioma antibody cytotoxicity assay, LM yields a positive reaction to antibodies in the sera of 80% of patients with astrocytomas and only 9% of normal blood-bank donors, suggesting that it shares common antigens with other astrocytic tumor lines . The varied characteristics of this glioblastoma-derived line emphasize the "multiforme" nature on the neoplasm and suggest that for characterization of any such line, multiple parameters are necessary to allow comparison with other long-term glioblastoma lines in the literature . The usefulness of the LM line in in vitro cell biological, immunological, chemotherapeutic, and radiobiological studies of gliomas makes such efforts very worthwhile. J Interferon Res, 1982, 2(1), 31 - 6 Induction of interferon by mycoplasmas in mouse spleen cell cultures; Beck J et al.; Interferon production in cocultures between lymphoma cells and lymphocytes was previously found to be caused by mycoplasma contamination of the tumor cells . Here we have shown that M . arginini caused interferon production in spleen cells of C57BL/6 mice . The producer cell in spleen cell cultures was insensitive to treatment with anti-theta serum plus complement and it was present in spleen cell cultures of homozygous nude mice . Macrophage depletion did not adversely affect interferon production whereas interferon production was abolished in cultures of cells obtained after passage through nylon wool columns . Collectively, these data suggest, but cannot definitively prove that interferon is produced by B cells . By the use of specific antisera it was found that by all probability the interferon produced represented interferon alpha. Oncology, 1982, 39(2), 101 - 3 Genetic damage caused by methylazoxymethanol acetate, the aglycone of cycasin . Analysis of sister-chromatid exchange frequency under in vivo conditions and in cell cultures; Gloser H; To extend the information on the mutagenic effect of methylazoxymethanol (MAM) acetate, which has been established as a potent carcinogen, the frequency of sister-chromatid exchange (SCE) was determined in bone marrow cells of Sprague Dawley rats and in cultured rat lymphocytes . To get differentially stained chromatids under in vivo conditions, the rats received 5-bromodeoxyuridine adsorbed on activated charcoal intraperitoneally . Chromosomes were stained with fluorescence plus Giemsa . In this study a significant increase of SCE frequency after the application of various concentrations of MAM acetate could be observed both in vivo and in vivo. Teratog Carcinog Mutagen, 1982, 2(3-4), 333 - 41 Use of Drosophila embryo cell cultures as an in vitro teratogen assay; Bournias-Vardiabasis N et al.; An in vitro assay has been developed for detecting teratogens by adding them to primary cultures of embryonic Drosophila cells and analyzing the degree of change in cell differentiation and tissue formation . Cultures are scored by an automated image analysis system that counts the number of myotubes and ganglia in culture . A decrease in their number compared to controls is taken as an indication of teratogenicity . In the group of 100 drugs and chemicals examined thus far in this assay, a high correlation with known teratogenic activity has been obtained with few false-positives or false-negatives . Procedures also have been developed for testing metabolic products of ingested compounds for teratogenicity . Mice and rats are fed the particular agent to be tested, and their serum is then added to the differentiating culture . Preliminary trials with human serum from patients receiving chemotherapy have also been performed . With further testing, validation, and incorporation of a metabolic activation system, it is hoped that this assay can be used, along with a battery of other in vitro assays, as a screen for the large number of agents awaiting comprehensive testing of their teratogenic potential . We also see the use of this assay as means to gain further information on the basic biochemical and developmental aspects of teratogenesis. Brain Res, 1981 Dec 14, 229(1), 163 - 81 Non-neuronal cell cultures from dorsal root ganglia of the adult cat: production of Schwann-like cell lines; Wrathall JR et al.; There are several methods available for the production of Schwann cell cultures from fetal and neonatal peripheral nervous tissue . We have investigated methods for producing Schwann cell-rich cultures from adult tissue . Dorsal root ganglia from normal adult cats were used to initiate explant cultures or subjected to primary dissociation . The resulting cultures were compared in terms of growth, the proportions of fibroblastic and Schwann-like cells in primary cultures and the effects of subculture on the relative frequency of these cell types . We found that excision and transfer of explanted ganglion pieces after 14 days in culture produced a secondary outgrowth rich in small, bipolar, spindle-shaped Schwann-like cells . Subculture of this outgrowth produced secondary cultures of predominantly Schwann-like cells with typical spindle-shaped morphology . The use of antimitotic agents in the media to inhibit fibroblast growth was not observed to be necessary or beneficial with this adult tissue . Primary dissociation of ganglia with enzymes (trypsin or collagenase) and mechanical agitation was even more effective in producing secondary cultures and cell lines that were, by morphological criteria, predominantly or exclusively Schwann-like cells . One of these Schwann-like cell lines, designated GSA, has been carried over 24 subcultures while retaining characteristic Schwann cell morphology . Cells of this line have been examined by scanning and transmission electron microscopy . Karyotype analysis indicates a chromosome complement consistent with the species of origin, a normal cat. Southeast Asian J Trop Med Public Health, 1981 Dec, 12(4), 544 - 8 Comparative sensitivity of mosquito inoculation and mammalian cell culture for isolation of some arboviruses in Indonesia; Tan R et al.; The sensitivity of parenteral inoculation of colony reared male Aedes aegypti and mammalian cell cultures for isolation of Japanese encephalitis virus and dengue virus were compared . The mosquito inoculation technique proved to be more sensitive for the isolation of dengue virus from the sera of febrile patients than did the mammalian cell cultures (Vero and BHK21) employed in these studies . Mosquito inoculation proved to be no more sensitive that the mammalian system for the isolation of Japanese encephalitis virus from field caught female mosquitoes. J Pharmacol Exp Ther, 1981 Dec, 219(3), 752 - 9 Inhibition of the expression of the "A" system of amino acid transport by anti-inflammatory drugs during cell culture growth and mitogenic stimulation of thymus lymphocytes; Bayer BM et al.; alpha-Methylaminoisobutyric acid uptake is mediated by two components in a variety of cell culture lines as well as in freshly isolated thymus lymphocytes . In all cell types, one component of uptake had characteristics similar to that of the "A" system and was selectively inhibited by the nonsteroidal anti-inflammatory drugs . Detailed studies with indomethacin showed that, in the presence of drug, a marked decrease in Vmax occurred with no impairment in the apparent affinity (Km) of the uptake system for either the amino acid or Na+ ion . Upon removal of drug, the capacity (Vmax) of the cell lines to take up amino acid recovered over the course of 6 hr . It is postulated that this time course may be related to a change in the number of functional carriers in the cell membrane . Marked increases in the rate of alpha-methylaminoisobutyric acid uptake by the Na+-dependent component were observed during exponential growth of cell cultures and in thymus lymphocytes stimulated by concanavalin A or amino acid deprivation . Irrespective of the cell type or mechanism of stimulation, indomethacin either blocked or partially suppressed this increase . Suppression of the Na+-dependent component of alpha-methylaminoisobutyric acid uptake was also evident in lymphocytes from indomethacin-treated rats . Selective inhibition of the A system before DNA synthesis may be one mechanism by which the anti-inflammatory drugs exert their in vitro cytostatic and in vivo immunosuppressive action Biomedicine, 1981 Dec, 35(7-8), 218 - 20 Tricyclic antidepressants induce sphingomyelinase deficiency in fibroblast and neuroblastoma cell cultures; Albouz S et al.; Tricyclic antidepressants (imipramine and desipramine) gave rise to an important decrease of sphingomyelinase activity in murine neuroblastoma and human fibroblast cell cultures . It occurred within 1 to 2 hours at a final concentration of 1 or 2 X 10(-5) M in cell culture medium . Other lysosomal enzymes such as acid lipase, arylsulfatases A and B and hexosaminidases were not modified . Low level of sphingomyelinase activity may be related to the amphiphilic characteristics of the drugs: iminodibenzyle which has the same tricyclic core but is devoid of the side chain necessary for amphiphilic properties had no effect . As iminodibenzyle has no therapeutic action, amphiphilic may be requisite to antidepressant properties of tricyclic drugs. J Natl Cancer Inst, 1981 Dec, 67(6), 1353 - 62 Cytotoxic effects and metabolism of benzo{a}pyrene and 7,12-dimethylbenz{a}anthracene in duodenal and ileal epithelial cell cultures; Quaroni A et al.; Two epithelial cell lines have been established from the duodenum (IEC-17) and the ileum (IEC-18) of outbred germfree Crl:CD(SD)GN rats . They have a very similar morphology and ultrastructure, a normal rat diploid karyotype, comparable growth rates, and a similar set of surface antigens as detected with monoclonal antibodies specific for intestinal epithelial cell surface proteins in vivo . Both cell lines do not grow in soft agar and when injected into syngeneic animals do not form tumors . The toxic effects of benzo{a}pyrene (BP) and 7,12-dimethylbenz{a}anthracene (DMBA) were studied in these two cell lines . The IEC-18 cells were found to be much more sensitive to both chemicals than the IEC-17 cells . In particular, at concentrations greater than 1 microgram/ml, DMBA completely and irreversibly inhibited cell proliferation in the IEC-18 cells, whereas it produced a less marked and reversible inhibition in the IEC-17 cells . The metabolism of BP and DMBA to water-soluble products was studied; BP was apparently metabolized at similar rates in the two cell lines, whereas a striking difference was observed with DMBA, which was metabolized at a rate 10-15 times greater in the IEC-18 cells than that in the IEC-17 cells . These results suggest that cultured cell lines derived from different portions of the intestinal tract have similar properties in vitro, but they may have very different responses to chemical carcinogens. Invest Ophthalmol Vis Sci, 1981 Dec, 21(6), 826 - 32 Evaluation of the antiherpetic activity of 2'-fluoro-5-iodo-ara-C in rabbit eyes and cell cultures; Trousdale MD et al.; 2-Fluoro-5-iodo-ara-C (FIAC), a new and potent drug, was tested for antiviral activity against several strains of herpes simplex virus (HSV), types 1 and 2 . Effective dose-50% (ED-50) determinations for FIAC ranged from 0.023 to 0.51 muM for HSV-2 . FIAC-treated cells did not exhibit any toxicity until the drug concentration was increased 2000-fold above the ED-50 level . Ocular herpetic keratitis in New Zealand white rabbits was treated with 1.0%, 0.1%, 0.01% FIAC beginning 3 days after inoculation wit HSV-1 (McKrae strain) . Topical chemotherapy was administered five times per day for 7 consecutive days . After 4 days of treatment, corneal epithelial involvement, conjunctivitis, iritis, and clouding were not detectable in eyes receiving 1.0% FIAC . Toxic reactions were not observed in rabbit eyes treated with FIAC drug . HSV was not prevented from spreading into the central nervous system when topical FIAC therapy was initiated on day 3 after inoculation. Endocrinology, 1981 Dec, 109(6), 2110 - 6 Inhibition of beta-adrenergic responsiveness in muscle cell cultures by dexamethasone; Smith TJ et al.; Cultures of two myogenic cell lines, L6E9 and L8, were grown in the absence or presence of dexamethasone . Dexamethasone (1 microM) completely inhibited the formation of myotubes . Partial inhibition (20-40%) was obtained at a concentration as low as 1 nM . Dexamethasone also inhibited beta-adrenergic responsiveness, as noted by decreases in isoproterenol-stimulated adenylate cyclase activity and cAMP accumulation . These effects were both dose and time dependent . In the presence of dexamethasone, the number of beta-adrenergic receptors, as assessed by {125I}iodohydroxybenzylpindolol binding, decreased coordinately with the decrease in cAMP . A high affinity, limited capacity cytosolic binding site for {3H}triamcinolone acetonide observed under control conditions (Kd = 0.7 nM; maximum binding, 2.7 pmol/mg protein) increased in number as a function of developmental state . These data indicate that glucocorticoids inhibit myogenesis and beta-adrenergic responsiveness in vitro. Brain Res, 1981 Nov 30, 225(2), 425 - 30 Oligodendrocytes of jimpy mice express galactosylceramide: an immunofluorescence study on brain sections and dissociated brain cell cultures; Bologa-Sandru L et al.; Brain sections and dissociated brain cell cultures of jimpy mouse (jp) were investigated for the presence of galactosylceramide (GC) by indirect immunofluorescence . Optic nerve and corpus callosum sections of 26-day-old jp exhibited many GC-positive cells . The GC staining pattern was similar in jp and normal cultures of the same age . These data suggest that the previously observed decreased amount of GC in jp brain is due to the inability of jp oligodendroglia to properly deposit GC in the myelin, while its synthesis is possible. Neurosci Lett, 1981 Nov 4, 26(3), 335 - 9 Relative changes in the amount of galactocerebroside during development as observed in mouse brain cell cultures; Bologa L et al.; Relative changes in the amount of galactocerebroside (GC) during development were measured in mouse brain cell cultures at different stages of development . For this purpose we used an 125I-labelled protein A indirect assay modified in the respect that the total amount of cellular proteins was evaluated before counting the radioactivity . The amount of GC greatly increased between the 10th and the 14th day of culture, then a steady state was reached between the 14th and the 20th day of culture . This change correlates well with the dynamics of the number of oligodendrocytes we observed earlier . These data suggests that the increase of the GC amount in culture during development corresponds to the increase in the number of GC-positive oligodendrocytes rather than to the increase in the number of GC molecules per cell. Vopr Med Khim, 1981 Nov-Dec, 27(6), 820 - 3 {Effect of remantadine, ribavirin and their combinations on the protein synthesis of influenza virus A in a cell culture}; L'vov ND et al.; Simultaneous use of ribavirin (I-beta-D-ribofuranosyl-1,2,4-triazol-3-carboxamide and rimantadine (alpha-methyl-I-adamantane methylamine HCL) was shown to effect most distinctly on protein synthesis in influenza virus A in the system studied as compared with the separate action of each of the drugs . Ribavirine inhibited the protein synthesis in rimantadine-resistant strain of influenza virus A. Tsitologiia, 1981 Nov, 23(11), 1324 - 7 {Growth of continuous and primary cell cultures on a liquid surface}; Gavriliuk BK et al.; A possibility to culture reinoculated BHK-21 cells and primary human embryo fibroblasts on the surface of liquid fluorocarbon is shown . Two types of growth of BHK cells on liquid surface can be distinguished: with the spreading of cells on the surface and formation of a monolayer, and with growth without cell spreading and with accumulation of cells in the form of clusters and small groups . Adhesion of cells to the liquid fluorocarbon surface is found to be weaker compared to the reproduction on the solid surface. Nippon Sanka Fujinka Gakkai Zasshi, 1981 Nov, 33(11), 1934 - 42 {Human ovarian myosarcoma and its cell culture (author's transl)}; Tsukazaki K; One case of a very rare myosarcoma of ovarium origin was observed and establishment of its cell lines from the fluid obtained by paracentitis was accomplished . This report is on the determination of the tumor and the biological characteristics of its cultured cells . (Determination of the tumor) (1) This tumor was diagnosed as a malignant of the right ovary, using bimanual examination, selective angiography of the uterine artery, ultrasonic tomography, and abdominal ascitic cell examination . (2) The morphological type of tumor was based findings of hematoxylin eosin . Silver, Mallory and phosphotungstic acid hematoxylin stainings . The tumor was diagnosed as an ovarian sarcoma and probably myogenic . However, a clear cross strain could not be demonstrated . (Cell biological characteristics) (1) Morphological characteristics of cultured cells: a) Phase-contrast microscopy and Papanicolaou staining revealed round or short and spindle shaped cells, with markedly enlarged nucleoli . These proliferated without exhibiting any tendency of contact inhibition . Also frequently recognized were giant cells, multinuclear cells, an some bizarre such as a starfish-shaped cell . b) Electron microscopy revealed that bundles of fibrils regarded as myofibrils existed in the cytoplasma, with dense patches within them, but a cross strain could not be demonstrated . (2) Morphological characteristics of the tumor cells grown in a nude mouse: a) The tumor cells demonstrated similarities to the original tissues by of H.E., Silver, and Mallary stainings . b) A number of fibrils recognized by the electron microscopic observation were 100 A in width and were arranged in a concentric circles . In addition to the light microscopic findings, the above findings indicated that this cell line originated from myogenic sarcoma . (3) Biological characteristics of the cultured cells: a) The number of chromosomes varied widely and spread aneuploidically, the highest chromosome number was 76 . b) Doubling time, Saturation density, and plating efficiency was 31.2 hr, 1.2 x 10(5)/cm2 and 43.9% respectively . c) These cells had a high sensitivity for trypsin and started morphological change rapidly. Vopr Virusol, 1981 Nov-Dec, (6), 677 - 87 {Cleavage of influenza virus hemagglutinin as affected by serum plasmin in cell culture and in vivo}; Zhirnov OP et al.; The effect of chicken, canine, and porcine plasm containing plasmin proenzyme, plasminogen, on influenza virus hemagglutinin produced in homologous and heterologous tissue cells was studied . The cells incubated with the homologous plasm were found to produce virions containing both cleaved and uncleaved hemagglutinin whereas the cells incubated without plasm or with heterologous plasm produced virions with uncleaved hemagglutinin . The infectious activity of the virus produced by cells with the homologous plasm was much higher than that of the virus grown without the latter or with heterologous plasm . The addition to the culture medium of plasminogen inhibitors together with plasm eliminated the proteolytic effect of the plasm on virion hemagglutinins resulting in the production of virions with uncleaved hemagglutinin and low infectious activity . In vivo, in experimental influenza infection of mice and chickens, highly infectious virus with cleaved hemagglutinin was isolated from the organs of the animals . The organs of the animals inoculated with inhibitors of proteolytic enzymes yielded virus of low infectivity with uncleaved hemagglutinin . Administration of proteases inhibitors to the infected animals prevented the spread of virus infection in animals and had a therapeutic effect . The experimental data suggest that activation of virions with proteolytic enzymes of the host, in particular, plasmin by means of hemagglutinin cleavage is the key mechanism in the development and spread of influenza infection in the host. Vopr Virusol, 1981 Nov-Dec, (6), 731 - 5 {Modelling of a chronic infection in a cell culture of the brain of suckling Syrian hamsters due to viruses of the tick-borne encephalitis complex}; Lebedeva GA et al.; The capacity of 3 members of the tick-borne encephalitis virus complex (Langat Tp-21, Sophyin, Elantsev) differing in their biological properties to induce chronic infection in primary cultures of suckling Syrian hamster brain cells (SHB) was studied . Three types of the infectious process were observed in these cells . Langat Tp-21 virus showed cytoproliferative activity in chronically infected SHB cell cultures; formation of cell colonies and alternation of phases of destruction and repopulation were observed with persisting Sophyin strain . The Elantsev strain in these cells produced infection with unestablished virus-cell equilibrium . The persisting viruses were shown to undergo changes in their biological properties consisting in the loss of the hemagglutinating activity and reduced pathogenicity for the susceptible animals. J Gen Virol, 1981 Nov, 57(Pt 1), 233 - 7 Comparison of the antiviral activities of various cloned human interferon-alpha subtypes in mammalian cell cultures; Weck PK et al.; Five human interferon-alpha (leukocyte) subtypes derived from genes cloned in Escherichia coli have been compared for their ability to induce antiviral activity against vesicular stomatitis virus infection of various mammalian cell cultures . These interferons, designated LeIF-A (IFN-alpha 2), -B, -C, -D (IFN-alpha 1) and LeIF-F, show different relative activities when assayed on human, bovine, hamster, mouse, rabbit and monkey cell lines . As with a natural human buffy-coat interferon-alpha preparation, three subtypes (LeIF-B, -C and -D) showed considerable activity on RK-13 rabbit cells, but two (LeIF-D and -F) also showed some activity on mouse L-929 cells . Of the five interferon subtypes examined, LeIF-F demonstrated the highest degree of species specificity. Acta Endocrinol (Copenh), 1981 Nov, 98(3), 345 - 51 Growth hormone and prolactin secretion by dispersed cell cultures of a normal human pituitary: effects of thyrotrophin releasing hormone, theophylline, somatostatin, and 2-bromo-alpha-ergocryptine; Adams EF et al.; Growth hormone (GH) and prolactin (Prl) secretion by a normal human pituitary in dispersed cell culture has been investigated . Prl secretion was significantly stimulated after 0.5, 1, 2 and 4 h exposure to 1, 10, 100 and 1000 ng/ml thyrotrophin releasing hormone (TRH) . Maximal effects were obtained with 10 ng/ml TRH at 2 h, higher doses being less effective . GH secretion was unchanged with the exception that 1 ng/ml TRH produced a small decrease at 4 h . GH and Prl secretion was significantly inhibited by incubation with 0.01, 0.1, 1 or 10 micrograms/ml 2-bromo-alpha-ergocryptine (bromocriptine) . The inhibition persisted for a further 24 h after removal of bromocriptine . Theophylline (10(-2) M) significantly increased GH and Prl secretion during a 4 h incubation and this effect was blocked by co-incubation with 10 ng/ml somatostatin (SRIF) . SRIF also inhibited basal GH and Prl secretion during 4 h and removal of SRIF and incubation for at further 4 h led to a rebound in GH and Prl secretion to levels greater than control . It is concluded that cell culture techniques previously applied to the study of hormone secretion by pituitary adenomas can be equally applied to the normal human pituitary. Biochim Biophys Acta, 1981 Oct 12, 677(2), 318 - 25 Incorporation of {3H}glucosamine into glycosaminoglycans in different cell culture conditions by rabbit aortic smooth muscle cells; Pietila K; This study sought to elucidate the optimal cell culture conditions for studies concerned with the incorporation of {3H}glucosamine into glycosaminoglycans by rabbit aortic smooth muscle cells . The incorporation of radioactivity into extracellular sulphated glycosaminoglycans was linear for at least 72 h and that into pericellular sulphated glycosaminoglycans for up to 24 h . The incorporation of radiolabel into hyaluronic acid was linear only up to 12 h . In the exponential growth phase the incorporation of {3H}glucosamine into sulphated glycosaminoglycans and hyaluronic acid proved to be less marked than in the stationary growth phase, but the highest values were nevertheless obtained immediately after trypsinisation . When studied in the stationary growth phase, cell density and incorporation of {3H}glucosamine were positively correlated in the case of hyaluronic acid, but in the case of sulphated glycosaminoglycans there was a negative correlation . The serum concentration of the incubation medium and the incorporation of radioactivity into hyaluronic acid were positively related . With sulphated glycosaminoglycans this was the case only after a 7-day preincubation in the different serum concentrations . When incorporation was studied without preincubation, the incorporation of radioactivity into sulphated glycosaminoglycans proved to be negatively associated with the serum concentration of the medium . The environmental pH of the cells was associated with the incorporation of radioactivity into hyaluronic acid and sulphated glycosaminoglycans in that between pH values 6.8 and 7.9 the incorporation of radioactivity increased when the pH of the medium was raised. Clin Chim Acta, 1981 Oct 8, 116(1), 1 - 7 Variation in argininosuccinate synthetase activity in amniotic fluid cell cultures: implications for prenatal diagnosis of citrullinemia; Jacoby LB et al.; Argininosuccinate synthetase activity was measured in amniotic fluid cells cultured from 25 normal fetuses and from 2 fetuses at risk for citrullinemia . Among the 25 control lines, argininosuccinate synthetase was low in epithelial-like cultures and high in more fibroblast-like cultures . The radioactivity incorporated from 14C-citrulline into protein was proportional to argininosuccinate synthetase activity . The activity of argininosuccinate lyase, the next enzyme in the urea cycle, was unaffected by a predominance of one or the other cell type . Argininosuccinate synthetase was low but detectable in cells from the two fetuses at risk for citrullinemia . The pregnancies were continued and both resulted in clinically normal females . Thus factors such as predominant cell type may affect area cycle enzyme activity in cultured amniotic fluid cells and should be taken into consideration in attempts to diagnose citrullinemia prenatally. Biochem Genet, 1981 Oct, 19(9-10), 871 - 80 High-resolution protein mapping of human fibroblasts and hair root cells: a standardized reproducible procedure considering the effect of cell culture parameters; Singh S et al.; The effect of different cell culture parameters on two-dimensional polypeptide maps of human fibroblasts is considered . Improved culture methods are introduced to get better resolution and reproducibility . Based on these investigations, highly standardized techniques for the protein mapping of this tissue and also of hair root cell lysates are presented . These methods seem to be quite suitable for analysis of cellular synthesized proteins and study of variability in normal subjects and in