bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphogenesis of Regenerating Fragments of Dugesia schubarti (Turbellaria tricladia)
Authors: Hauser Josef , Friedrich Sirlai M.G.
Published: October 2008

An extensive study of regeneration processes from the point of view of the axial gradient theory and its corollary, the possibility of forming two heads from one fragment (the Janus head problem) was undertaken on the South American species Dugesia schubarti. Altogether 330 specimens were used, cut into 2,640 pieces and the regeneration of each of them was followed to the end result. Concerning the role of an axial gradient in the regeneration processes the results were not supportive. Anterior fragments often regenerated less completely (eyes and auricles without complete heads) than more posterior ones, although the differences were not sharp, due to individual variations of physiological nature. The Janus head regeneration, one of the postulates of the axial gradient theory, was analyzed both on preauricular (parts A) and postauricular fragments (parts B). The regeneration of parts A was less perfect than that of parts B. Although a considerable number of the part A fragments regenerated normally, the majority of the cases remained incomplete for a long time and eventually disintegrated without completing the regeneration process. The regeneration of parts B proceeded more evenly and the death rate was also much lower. The only irregularity observed was a great number of cyclopic regenerates, i.e. heads with one single eye in the midline. Some of these cyclopic heads remained permanently in this condition but most of them later separated in two eyes but with a pigment bridge between them, and in others the cyclopic eye separated in two normal eyes at the end of the regeneration. The Janus head phenomenon was never observed.
Influence of Vitamins C and B12 on the Survival Rate of Mice Bearing Ascites Tumor
Authors: Poydock Eymard , Reikert D. , Rice J.
Published: October 2008

The survival rate of mice bearing P388 leukemia and Ehrlich carcinoma was increased after treatment with a mixture of vitamins C and B12. All the mice receiving the vitamins outlived the control group. At the termination of the experiment, 30 days later, 50% of the treated mice appeared normal and healthy, whereas the remainder showed signs of tumor distention.
Primary Culture of Chondrocytes Embedded in Collagen Gels
Authors: Yasui Natsuo , Osawa Suguru , Ochi Takahiro , Nakashima Hiroshi , Ono Keiro
Published: October 2008

Chondrocytes isolated from sternal cartilage of 13-day embryonic chicks were dispersively embedded inside the collagen gels in Ham’s F-12 medium containing fetal calf serum. Viability, three-dimensional growth and deposition of extracellular matrix in the living cultures were evidenced by increased cell number, morphology and autoradiographic observations, respectively. The cells increased 2- to 3-fold in 1 week and occupied ‘chondrocytic lacunae’ surrounded by ‘territorial matrix’. A more extensive development of the tissuelike structure was produced by high density cultures. Exogenous collagen seemed to be incorporated or rearranged into the newly formed matrix. This new culture method may provide suitable conditions for differentiated chondrocytes to accumulate metachromatic matrix in vitro.
Studies on the Toxicity and Binding Kinetics of Abrin in Normal and Epstein-Barr Virus-Transformed Lymphocyte Culture-I
Authors: Witten Matthew , Glassman Armand B. , Bennett Carol E.
Published: October 2008

The effects of treatment with varying doses of abrin, a Z > -galactose binding lectin, on DNA and protein synthesis of normal and Epstein-Barr virus (EBV)-transformed lymphocytes have been previously investigated. Using data on EBV-transformed lymphocyte cell density as a function of both time and dose of abrin, the authors introduced the concept of self- and cross-coupling metabolic variables as a means of understanding how abrin affected DNA and protein uptake. In this paper, the self-coupling constant is studied in more detail and the relationship between DNA and protein synthesis is further expanded. We find that there is a significant linear relationship between DNA and protein synthesis in normal lymphocyte culture as measured by abrin interaction in the culture. We further find that there is a much stronger relationship between these variables in EBV-transformed lymphocyte culture. This relationship is further examined, and possible analytic equations are expressed.
Tumor-Promoting Phorbol Esters Induce Macrophage Differentiation from Bone Marrow Precursors
Authors: Keller R. , Keist R.
Published: October 2008

The tumor-promoting phorbol diester, 12-0-tetradecanoyl-phorbol-13-acetate (TPA), induces in liquid cultures of rat and mouse bone marrow cells a sequence of events strikingly similar to those initiated by colony-stimulating activity known to regulate growth. Changes include stimulation of DNA synthesis and induction of cell proliferation, enhancement of adherence to the substratum, increase in lysozyme secretion, the expression of plasma membrane receptors for the Fc portion of IgG and the capability of manifesting lymphokine-induced, immunologically nonspecific long-term cytotoxicity. These findings indicate that TPA selectively stimulates precursors of the mononuclear phagocyte lineage to proliferate and to differentiate into macrophages, thus mimicking the effects of macrophage colony-stimulating activity.
Polyadenylated mRNAs from Various Developmental Stages of Xenopus laevis
Authors: De Bernardi Fiorenza
Published: October 2008

In Xenopus laevís embryos, the 26 S polyadenylated mRNA, coding for the myosin heavy chain, shows a maximum relative concentration as measured by the 3H-poly(U)-hybridization technique, at the neural-plate stage (st. 12.5 of Nieuwkoop and Faber, [NF]) only in the dorsal (ectodermal and mesodermal) region, i.e. shortly before the morphological appearance of the somites. On the contrary, myosin-heavy-chain mRNA cannot be observed in the ventral region with the same technique. This 26 S mRNA begins to be hybridizable at the gastrula stage (st. 10 NF). Polyadenylated mRNAs from postgastrula stages were translated in a cell-free system of rabbit reticulocytes, and the translation products were analyzed by polyacrylamide-gel electrophoresis and immunoprecipitation. It was found that protein recognizable as the heavy chain of the muscle myosin had been translated. Its possible role on the induction of somites is discussed.
Effects of Ouabain and Valinomycin on in vitro Erythroid Colony Formation (CFU-e and BFU-e)
Authors: Gallicchio Vincent S. , Della Puca Richard Delia , Murphy, Jr Martin J.
Published: October 2008

Ouabain enhances the number of clonally derived erythroid stem cell colonies (CFU-e and BFU-e) from normal murine bone marrow. Ouabain is known to inhibit lymphocyte proliferation by blocking the Na+/K+ pump. To further explore these Na+/K+ ATPase-associated interrelationships, valinomycin, an inhibitor of Na+/K+ ATPase was employed. The addition of valinomycin (10-11 to 10-15M) in the presence of ouabain and erythropoietin (Ep) did not alter the erythroid colony-forming stimulation which was characteristic of cultures in which only ouabain (10-15M) and Ep were added. Valinomycin did effectively block both CFU-e and BFU-e formation when it was added in the range of 10-3 to 10-9M. The mechanism of this valinomycin-induced inhibition and ouabain stimulation is discussed.
Lectin-Defined Cell Surface Glycoconjugates of Pancreatic Cancer Cells and Their Nonmalignant Counterparts
Authors: Raedler A. , Schmiegel W.H. , Raedler E. , Arndt R. , Thiele H.-G.
Published: October 2008

Alterations of cell surface carbohydrates of human pancreatic cancer cells from long-term cultures (COLO 357, RPMI 7451, PC 103, PC 107) were assessed ultrastructurally by use of an array of lectin-enzyme conjugates, and compared with lectin-defined changes of glycoconjugates on human pancreatic tissue sections of normal and various pathological conditions. Ulex europeus and, to a lesser degree, Lotus tetragonolobus lectin binding indicate that L-fucose-containing glycoconjugates are expressed predominantly on pancreatic cancer cell surfaces, but not, or restricted to intracytoplasmatic structures, on nonmalignant pancreas cells. A comparable binding pattern to pancreatic carcinoma cells is found for Phaseolus vulgaris lectin. This is in contrast to the results with soy bean lectin, the reactivity of which was not restricted to cancer cell surfaces, and with Helix pomatia lectin, which did not bind to pancreatic cancer cells at all, although the latter three lectins possess similar sugar specificities. Between the long-term-cultured malignant pancreas cells differences were observed concerning the binding of wheat germ and pokeweed lectin. Besides, qualitative assets of lectin-binding absorption analyses elaborated quantitative differences in the expression of lectin-defined glycoconjugates on pancreatic cancer cell surfaces.
Biological Activity of Synthetic Subunits of Streptococcus Peptidoglycan
Authors: Rotta J. , Zaoral M. , Rýc M. , Straka R. , Ježek J.
Published: October 2008

A series of synthetic subunits and analogues of streptococcal peptidoglycan was prepared and used in fever and tolerance experiments on rabbits. The lengthening of the chain of the peptide moiety of peptidoglycan did not result in pyrogenic activity, except for hexa-peptide. Attachment of the muramyl residue rendered the peptides pyrogenic. The activity of such materials varied in degree and was rather in an indirect relation to peptide chain length. A change in the configuration of C4-OH or C3-OR in the muramyl residue resulted in a profound decrease in pyrogenicity. No inhibitory effect of N-acetylmuramyl-.D-alanyl- D-iso-glutamine on muramyldipeptide (MDP) pyrogenicity could be demonstrated. Repeated administration of MDP resulted in the induction of tolerance to the pyrogenicity of this substance in rabbits. These animals were not tolerant to the pyrogenicity of peptidoglycan. Nontolerance was also observed in reciprocal experiments with these materials as well as in trials with hexapeptide and peptidoglycan given in either order. The data are consistent with the assumption that peptidoglycan contains more than one biologically active subunit. There is a structure-to-function relationship. The knowledge of the biological effects of the synthetic analogues is essential for the prospect of their use under model or human conditions.
Histopathologic Evaluation of Response to Treatment of Human Tumors Grown in the Nude Mouse
Authors: Kyriazis Aikaterini A. , Kyriazis Andreas P. , Kereiakes James G. , Soloway Mark S. , McCombs William B.
Published: October 2008

The histopathologic changes following chemotherapy treatment of a number of human tumors grown in nude mice were evaluated. On the basis of the histopathologic profile, three response levels were recognized – a mild response, a moderate response and a severe response. Severe response was characterized by arrest of cell division and profound nuclear-cytoplasmic degenerative changes. Regrowth of effectively treated tumors originated in clusters of cells most probably representing resistant tumor cell clones. Histopathologic changes represent a sensitive indicator of the response of nude mouse grown human tumors to anti-cancer agents. Availability and correct interpretation of the post-treatment histopathologic picture is of importance in selecting the proper combination treatment which would maximize tumor response.
The Effect of Oral Contraceptives on Sister Chromatid Exchange, Blast Transformation, Mitotic Index and Micronuclei Formation
Authors: Dutkowski Regina T. , Kevin Monica J. , Jenkins Edmund C.
Published: October 2008

Lymphocytes from 5 individuals were cultured to study the effect of mestranol and norethindrone on sister chromatid exchange (SCE), blast transformation, mitotic index and micronuclei formation. Four combinations of the drugs were compared to water and ethanol controls. Some steroid combinations increased the SCE frequency compared to ethanol controls. There was no uniform effect on blast transformation or mitotic index. In 3 individuals, micronuclei formation was reduced in treated cultures. In conclusion, contraceptive steroids may be mutagenic in some individuals.
Mechanisms of Lysosomal Enzyme Secretion by Human U-937 Monocytes
Authors: Leoni Patricia , Dean Roger T.
Published: October 2008

Lysosomal enzyme secretion was studied in U-937, a mononuclear phagocyte cell line. The secretion of the marker enzyme, β -N-acetyl-D-glucosaminidase, was low when the cells were challenged with phagocytosable stimuli (asbestos, zymosan, opsonised zymosan). Ammonium cloride and cytochalasin B induced secretion over 24 h of incubation. Phorbol myristate acetate and F-methyl-leucyl-phenylalanine, did not have any effect on secretion. It is suggested that U-937 cells may provide a useful model for the study of mononuclear phagocyte secretory pathways.
Discrimination between Macrophage- and NK-Type Tumoricidal Activities via Anti-Asialo GM1 Antibody
Authors: Keller R. , Bächi T. , Okumura K.
Published: October 2008

The usefulness of asialo GM1 a glycolipid surface marker, to define the effector cell types involved in tumor resistance in vitro and in vivo was assessed. Pretreatment of rat effector cells with anti-asialo GM1 antibody plus complement in vitro either abrogated or markedly diminished NK activity; in contrast, macrophage-type cytocidal activity was not diminished by such pretreatment. Similarly, systemic inoculation of anti-asialo GM1 antibody selectively eliminated NK activity, leaving macrophage-type tumoricidal reactivity intact. Finally, such pretreatment did not diminish host resistance in an in vivo tumor model in which the available evidence suggests a critical role for macrophages. The asialo GM1 marker may thus be useful in delimitating the tumoricidal capacity of cells exhibiting NK activity from that mediated by other cell types.
Macrophage-Mediated Inhibition of Melanoma Cell Growth in Nude Mice
Authors: Adelman Daniel C. , Erickson Kent L. , Gershwin Eric
Published: October 2008

The effects of macrophages or sera from tumor-transplanted or control syngeneic and allogeneic mice on the latency and growth rate of P51 murine melanoma cells were determined after transplantation into congenitally athymic (nude) mice (tumor neutralization test). Syngeneic macrophages from tumor-bearing mice (TBM) inhibited melanoma growth in the nude mouse more than control macrophages, additionally macrophages from sensitized allogeneic mice inhibited melanoma growth to a greater degree than did allogeneic control macrophages. Sera from TBM inhibited melanoma growth as compared to control cells alone. Macrophages obtained after 14 days were also cytolytic towards the melanoma target in vitro. Despite the growth of large local masses, no evidence of distant metastases was found. The nude mouse thus provides an appropriate model for this tumor to portray in vivo immunotherapy.
Light Microscopy Investigation of the Action of the Unsaponifiable Residue of Vegetable Oils on Rat Periodontal Disease Induced by a High Carbohydrate Diet
Authors: Mattout P. , Rachlin G. , Maupu H.
Published: October 2008

Rats, submitted to a sucrose diet for 12 months, were normally fed for another 6 months either with or without addition of the unsaponifiable residue of vegetable oils. It appears that unsaponifiable substances reinforce the collagen fiber network of the periodontium. The presence of a dense supracristal barrier accounts for the lack of an infraosseous pocket and for the limitation of bone resorption despite the high level of the sucrose diet.
Resistance and Susceptibility to Pulmonary Metastasis of Lewis Lung Carcinoma in Different Mouse Strains
Authors: Hergueux Josiane , Bischoff Pierre , Donner Mireille
Published: October 2008

The ability of the highly metastatic 3LL tumor of C57B1/6 (H-2b) origin to form pulmonary metastases after an intramuscular transplantation was investigated in various allogeneic mouse strains. Metastatic proliferation was observed in all tested strains of B10 genetic background. In mice of A genetic background, metastases formation was reduced and a strong resistance to metastatic progression seemed to require the association of the A genetic background with the H-2f haplotype (A.CA strain). Determination of 3H-TdR uptake in the lungs of C57B1/6 and A.CA mice bearing large local tumors confirmed these results. The development of lung tumor nodules following an intravenous injection of 3LL tumor cells was also different in these two strains. Thus, A.CA strain appears as a useful model system for studies of mechanisms involved in metastases formation.
Effect of the Inhibition of Nucleic Acids and Protein Synthesis upon the Development of Melanotic Tumors in Drosophila
Authors: Ghelelovitch S.
Published: October 2008

Ethidium bromide and chloramphenicol which inhibit the synthesis of DNA and of proteins in mitochondria, respectively, are devoid of any important effect on the development of melanotic tumors in Drosophila. Mitomycin C, added to the food of larvae carrying the tu48amutant gene, increases the number and the size of tumors. It is effective only if the treatment is begun long before the appearance of the tumors and acts probably by weakening the defence reactions of the host. Actinomycin D, an inhibitor of RNA synthesis, increases the number of tumors most effectively if administered at the time of tumor gene activity. Cycloheximide, which is known to inhibit protein synthesis on cytoplasmic ribosomes, is effective during the entire larval life and increases the number of tumors. The results suggest that the melanotic tumor development in Drosophila is linked to the loss of cellular functions rather than to the acquisition of new ones.
Induction of Somites by Myosin mRNA
Authors: Bolzern A.M. , Leonardi Cigada , De Bernardi F. , Fascio U. , Maci R. , Ranzi S. , Sotgia C.
Published: October 2008

The effects of the messenger for myosin heavy chain (26S mRNA) on postnodal explants of chick embryo blastoderm were studied. Somites do not differentiate in the post-nodal explants of chick embryo cultivated by New’s method. They are induced when postnodal pieces are cultivated in the presence of a 26S mRNA extracted from chick leg muscles or in the presence of myosin. 26S mRNA plus actinomycin D induces small somites. 26S mRNA of duck, rabbit, or trout induce somite structures often built up of cells separated by large spaces and joined around a large myocele. Crayfish 26S mRNA or chick myosin light chain induce columnar cells connected around a cavity. Liver or kidney mRNA do not induce. The induction process can be summarized as follows: 26S mRNA codes for myosin (heavy chain) and the myosin (heavy chain) induces the somites. Induction of somites by mRNA can occur in the presence of actinomycin D but not when there is mRNA plus puromycin. It does occur when myosin acts in the presence of puromycin. Myosin and its heavy chain are present in chick blastoderm before the appearance of somites. Induced somites are able to induce neural plates. We conclude that in normal development somites are induced by myosin.
Distribution of Surface Anionic Sites on Mouse Hybrid Myelomas
Authors: Marikovsky Yehuda , Wang Lynn , Inbar Michael
Published: October 2008

The surface anionic site distribution on membranes of a monoclonal antibody-producing hybridoma cell line, and its two parental cells: normal spleen cells of immunized BALB/c mice and cells from a mouse myeloma line (NS-1), were investigated with the aid of the cationized ferritin (CF) labelling method, following glutaraldehyde/formaldenyde fixation of cells. The patch-like CF distribution on the hybridoma cells is similar to that of the NS-1 myeloma cells, but distinct from the even and continuous CF distribution of the immunized and nonimmunized normal spleen lymphocytes. The similarity in the formation of patch-like CF heaps, both on myeloma and hybrid cells is discussed in respect to the surface charge characteristic determined by cell fusion.
Role of Prostaglandins in Metastatic Dissemination of Cancer
Authors: Tisdale Michael J.
Published: October 2008

Prostaglandins are secreted by a variety of animal and human tumours. A higher prostaglandin production is sometimes associated with a decreased tendency to metastasis, though there are features of the metastatic cascade where prostaglandins might be expected to facilitate dissemination. Prostaglandins may aid metastases through the mediation of proteolytic enzyme production, by prostaglandin-induced neovasculanzation or by subversion of the immune response. Inhibitors of platelet aggregation such as prostacyclin on thromboxane A2 synthetase inhibitors may be useful in the prevention of metastatic spread of cancer.
Differentiation of Mononuclear Cells into Multinucleated Osteoclast-Like Cells
Authors: Severson Aden R.
Published: October 2008

Experimental evidence accumulated in recent years suggests that the osteoclast is derived from the fusion of mononuclear precursors which are of hematopoietic origin. Mononuclear cells were isolated from the spleen and bone marrow of young rats in order to examine osteoclast formation. The isolated cells were placed in diffusion chambers containing devitalized bone fragments freed of soft tissue, and the chambers sealed and placed in the peritoneal cavity of host rats. The host animals were killed after 4 days, and the bone removed from the chambers for examination. Light-microscopic examination demonstrated two types of cells adjacent to the bone surface, one a flattened and elongated mononuclear cell, and the other a larger and frequently multinucleated cell which had the morphological appearance of an osteoclast. Scanning electron microscopy demonstrated numerous flattened and elongated cells adjacent to the bone surface, as well as a second cell type which had dorsal membrane specializations and numerous lateral microprojections attaching to the bone surface. The second cell type was thought to correspond to the osteoclast-like cells seen with light microscopy. The observations suggest that osteoclast-like cells differentiate from mononuclear precursor cells of hematopoietic tissue.
Erythroid Stem Cells in Rauscher Viral Erythroleukemia
Authors: Gallicchio Vincent S. , Murphy, Jr. Martin J.
Published: October 2008

Results reported herein describe the expansion of erythroid stem cells (CFU-e and BFU-e) from marrow and spleen cells from mice infected with Rauscher leukemia virus (RLV). Maximum colony numbers were seen by 5 weeks after viral inoculation. The increase in splenic CFU-e and BFU-e was related to development of splenomegaly, the latter being a characteristic feature of murine oncornavirus infection. Both splenic and marrow RLV-derived CFU-e were erythropoietin (Ep) dependent. However, splenic and marrow RLV-derived BFU-e proliferation occurred at Ep levels considered suboptimal for normal colony formation. This increased erythroid stem cell proliferation may be due in part to the increased demand on erythropoiesis as a result of the profound fatal anemia which occurs in RLV-induced erythroleukemia. These studies suggest that factors operating at the level of BFU-e may enhance erythropoiesis, and hence may be a direct result of murine oncornavirus infection.
Effect of Hydrocortisone on the Proliferation of Cultured Skin Fibroblasts from Normal Individuals and Individuals at High Risk of Colon Cancer
Authors: Kopelovich Levy
Published: October 2008

In the present study we have compared the mitogenic effects of hydrocortisone (HC), both in the cloning efficiency (CE) assay and in semisolid agar, on skin fibroblasts (SF) obtained from individuals with hereditary adenomatosis of the colon and rectum (ACR) and their age-matched controls. The maximum stimulation of both cell types in the CE assay occured at an HC concentration of 500 ng/ml, but normal adult SF (NSF) were more sensitive to the mitogenic effects of HC than were ACR SF. The stimulation of cell proliferation in agar by HC (range 0–20 µg/ml) was apparently maximal at about 5 µg/ml of HC. However, NSF proliferated in agar containing HC considerably better, proportionately, than did ACR cells, whereas no growth of normal cells in agar was seen in the absence of HC. Normal neonatal foreskin fibroblasts (FOS) and colon adenocarcinoma cells (HT-29), in that order, were increasingly more refractory to the proliferative effects of HC in both the CE assay and in semi-solid agar. Charcoal-treated serum (from which steroids were largely removed) supported to a varying degree the growth of colon adenocarcinoma cells, FOS and ACR SF, but not of NSF cells. On the other hand, addition of HC to charcoal-treated serum primarily stimulated the proliferation of NSF cells. The reduced sensitivity of ACR SF to HC may be closely linked to mechanisms associated with initiation and promotion for this form of cancer.
Hydrophobic Affinity Cell Partition Detects Alterations in Surface Properties of Erythrocytes in Rats Bearing a Subcutaneous Leydig Cell Tumour
Authors: Gascoine Paul S. , Dix Clive J. , Fisher Derek
Published: October 2008

The partition of rat erythrocytes in dextran-polyethylene glycol aqueous two-phase systems containing the hydrophobic affinity probe polyethylene glycol-palmitate has been examined. Erythrocytes from rats bearing the subcutaneous Leydig cell tumour F344 showed a significantly reduced top phase partition compared with erythrocytes from non-tumour bearing control rats, indicating a decreased hydrophobicity of the erythrocyte surface that was associated with tumour growth. Cell partition of readily accessible erythrocytes may offer a simple procedure for following the development of certain tumours.
Putative Immunological Influence upon Amphibian Forelimb Regeneration
Authors: Sicard Raymond E. , Laffond William T.
Published: October 2008

The effect on amphibian forelimb regeneration of several substances known to be immunoactive in mammals was examined. Only cobra venom factor and antilymphocyte serum adversely affected the rate of regeneration. Interferon, thymic ‘helper’ (TE-H) and thymic ‘suppressor’ (TE-S) fractions (from calf thymus extracts) increased the frequency of morphologically abnormal regeneration. In addition, TE-S increased while TE-H decreased regenerate volume relative to normal and experimental control regenerates. These data are consistent with the notion that the immune system might be influencing the progress of limb regeneration and that the later stages and events of regeneration might be most sensitive. However, proof that the aberrations produced were the result of actual alterations in immunological activity is not yet available.
The Effect of Methadone and Naloxone on Cultured Rat Liver Cells
Authors: Beverley Cordia L. , Higgins Paul J. , Borenfreund Ellen
Published: October 2008

Opioids modify hepatic function in vivo, however, a direct effect of this class of drugs on liver cells has not been demonstrated. The potential effect of opioids on liver parenchymal-type cells, therefore, was studied using cultured albumin-secreting rat hepatoma cells. Liver cells were incubated with methadone or naloxone individually or in combination. Dose-response analysis indicated that concentrations of either or both drugs in excess of 2.5 × 10-5Mwere clearly cytotoxic to cultured hepatoma cells. At a concentration (2.5 × 10-7M) at which no adverse effect on hepatoma cell viability or growth rate was observed, naloxone, methadone, or naloxone plus methadone produced a 26, 41, and 63% decrease in trichloroacetic acid-precipitable protein (per 106 cells), respectively, when compared to control. The inhibitory effect of naloxone, methadone, or naloxone plus methadone on albumin accumulation in the culture medium was greater than the drug-induced reduction of protein synthesis. These studies demonstrate that opioids have several direct effects on cultured hepatoma cells and, therefore, raise the question of whether clinically significant hepatic dysfunction may be produced by the direct action of opioids on the liver.
Detection of Primary Antimitochondrial Activity of Drugs in Cultured Mammalian Cells Utilizing Glutamine as the Carbon Source
Authors: Patel R. , Hola M. , Riley P.A. , Wilkie D.
Published: October 2008

Growth of guinea-pig keratocytes (GPK) proceeded normally in standard medium in which glutamine (mitochondrial substrate) replaced glucose as the carbon and energy source. Cells in the glucose-free glutamine cultures were much more sensitive to the toxic and growth-inhibiting effects of the antimitochondrial drugs ethidium bromide, chloramphenicol and oligomycin than cells in glucose-containing cultures. In the latter, cells continued to proliferate in the presence of these drugs after 2-3 days incubation, but in the non-fermenting cells growth was arrested within 24 h and there was more than 95% cell death after 2 days. Cycloheximide, a general inhibitor of protein synthesis in eukaryotic cells, showed no selective inhibition of growth and glutamine and glucose cultures were equally affected. The system appears to be useful for the detection of primary antimitochondrial activity of drugs in general.
The Characterisation of Gliomas Using Human Monoclonal Antibodies
Authors: Sikora Karol
Published: October 2008

Malignant gliomas contain large numbers of invading lymphocytes. The function of these lymphocytes is unknown. It is likely that they are involved in host defence against the developing tumour. By isolating these cells and fusing them with a suitable myeloma system, hybrids can be established and their antibody activity analysed. Human monoclonal antibodies reactive to glioma cells have now been isolated and their specificity has been determined by radioimmunoassay, binding assays and immunoprecipitation. Furthermore, such antibodies can be radiolabelled with 131I and administered intravenously to localise tumours in patients. These antibodies have therapeutic potential as selective targeting agents for chemotherapy and other cytotoxic agents.
Influence of Prolonged Life Span on Receptor ‘Memory’ in a Unicellular Organism, Tetrahymena
Authors: Csaba G. , Darvas Zsuzsa , László Valéria , Vargha P.
Published: October 2008

The first interaction of the Tetrahymena with a hormone-like molecule – diiodotyrosine (T2) in the present study – gives rise to hormonal imprinting, the effect of which is being preserved by receptor ‘memory’ over as many as 500 generations. The first interaction with the hormone modifies the growth potential of the cell also without reexposure. In the present study, we followed up the fate of receptor ‘memory’ in Tetrahymena cells maintained without exchange of medium, and thereby inhibited in division, over the period of a year. The cells continued to display increased responsiveness – receptor ‘memory’ – over the first 3 months which normally cover the change of 500 generations, and to a lesser degree over the next 3 months (after 6 months) as well, but they showed loss of ‘memory’ after 9 and 12 months, as judged from the similarity of their growth response to the control. At 9 months, the cells were able to recover their original growth potential within 4 days of return to normal medium, but the ‘memory’ of the behavioral (growth response) modification induced by T2 returned, in a not fully convincing form, only after 48 days. Receptor ‘memory’ returned in 21 days. It follows that receptor ‘memory’ can equally persist by cell-cell transmission or within the same nondividing cell of extremely prolonged life span. Evidence has also been presented that loss of receptor ‘memory’ with ageing is only virtual, because it can be reactivated if the aged cells are ‘rejuvenated’ under appropriate conditions.
Polyamine Metabolism in P388 Leukemia Cells and in Ascites Tumor-Bearing Mice
Authors: Kremmer T. , Selmeci L. , Bardócz Susan , Holczinger L. , Bálint Susan
Published: October 2008

Alterations in ornithine decarboxylase (ODC) activity and in the polyamine and nucleic acid (RNA and DNA) concentrations were studied in P388 leukemia cells and in the host liver at different times after intraperitoneal inoculation of 5 × 106 tumor cells into BDF1 mice. ODC activity of leukemia cells had a maximum at day 5 after tumor transplantation. Cellular spermidine concentration declined significantly during the first 5 to 6 days. The RNA concentration of tumor cells changed parallel to that of spermidine. In the livers of ascites tumor-bearing mice ODC activity was 5- to 20-fold of control and had a maximum at days 5 to 6 after tumor cell inoculation. Spermidine concentration in the host liver increased, whereas spermine decreased gradually with tumor growth.
Effects of Glucocorticoids on Glioma Cells in Culture
Authors: Freshney R.I.
Published: October 2008

In vitro studies have shown that glucocorticoids have a cytostatic effect on glioma cells at high cell densities but enhance cell survival and proliferation at low cell densities. The cytostatic effect is not cytotoxic and may be mediated via a membrane modification altering cell-cell interaction. Cell interaction is also implicated in differentiation in glial cells and the inducing effect of glucocorticoids may be mediated in part by their effect on cell interaction. Induction of differentiation by glucocorticoids is accompanied by a reduction in malignancy-associated properties and the possibility has emerged that glucocorticoids may be an essential component in attempts to modify the malignant behaviour of glioma cells.
Cathepsin B-Like Proteinase as a Marker for Metastatic Tumor Cell Variants
Authors: Köppel P. , Baici A. , Keist R. , Matzku S. , Keller R.
Published: October 2008

Serial transplantation of a spontaneous BDX rat tumor, classified as an anaplastic sarcoma, gives rise to two variants; a rapidly growing nonmetastatic line (AS) and a slowly growing, invasive, and highly metastatic variant (ASML). The availability of two cell lines of the same origin but with markedly differing metastatic potential offers an ideal model for the identification of the cellular properties involved in invasive and/or metastatic behavior. The present work focuses on the pattern of various proteinases in the two tumor cell variants. The findings disclosed one major consistent difference which relates to a cathepsin B-like cysteine proteinase. The metastatic ASML variant manifests exceedingly high intracellular cathepsin B-like activity; in the nonmetastatic AS variant, the activity of this proteinase is significantly lower. Other proteinases, in particular elastase-like, chymotrypsin-like, collagenase-like enzymes and plasminogen activator, showed low, essentially comparable activity patterns. Thus, cathepsin B-like proteinase is a marker enzyme of the metastatic ASML tumor cell variant.
Autoantibody Activity against Evolutionary Conserved Juxtanuclearly Arranged Antigen in Mice with Tumors Induced by a Progressor Moloney Sarcoma Virus Transformant
Authors: Weiland E. , Weiland F. , Thiel H.-J.
Published: October 2008

Adult STU mice with tumors induced by a progressor Moloney sarcoma virus transformant developed serum antibodies against juxtanuclearly arranged structures (JNS). 14 days after tumor cell transplantation the antibody activity against JNS could be observed. During repeated tumor transfers anti-JNS development always accompanied tumor proliferation. In indirect immunofluorescence microscopy JNS were recognized by these antibodies not only in cultured cells of murine origin (normal as well as transformed cells), but also in cells of other mammalian species (rat, bat, hamster, dog, goat, cattle, horse) and even in cells of members of two further vertebrate classes: avian embryo fibroblasts and a fish-derived cell line. In the various cell lines tested, the morphology of the JNS differed, but they were always arranged close to the nucleus. The distinct perinuclear and juxtanuclear position is indicative for the Golgi region; the staining pattern after osmium impregnation and immunoelectron microscopy supported the localization of the recognized structures in this cellular compartment. Drugs like monensin or colcemid, which are known to influence Golgi morphology and function, altered the staining pattern of the antibodies drastically. The widespread occurrence of this antigenic determinant(s) in cultured cells from different species suggests that this Golgi component is highly conserved in evolution. According to immunoprecipitation studies four proteins with apparent molecular weights of 250,000, 96,000, 53,000, and 38,000 daltons were recognized by these antisera. It remains to be determined, if these molecules are involved in the described serological reaction.
Acute Effects of Ultraviolet Light B on Morphology and Epidermal Cell Kinetics in Human Skin Transplanted to Nude Mice
Authors: Græm N. , Povlsen C.O.
Published: October 2008

Grafts of human skin on nude mice were irradiated with varying doses of ultraviolet light B and at various intervals were subjected to histological examination and determination of the epidermal 3H-thymidine labelling index. The studies showed that the human skin in the foreign milieu of the nude mouse retained its ability to respond to phototoxic damage. The findings suggest that the nude mouse/human skin model could be a valuable tool in human photodermatological research.
Receptor ‘Memory’ in Tetrahymena: Does It Satisfy the General Criteria of Memory?
Authors: Csaba G. , Németh G. , Vargha P.
Published: October 2008

Diiodotyrosine induced receptor ‘memory’ at a concentration as low as 10-18M. Repeated exposure enhanced cellular responsiveness. Treatment with diiodotyrosine for 1 h, 4 times, induced receptor ‘memory’ more efficiently than a single uninterrupted treatment for 4 h. Immediately after induction, the receptor ‘memory’ is subject to retroactive interference by foreign hormonal stimuli, and can be extinguished completely by combined hormone treatment. Thus, the phenomenon of retroactive interference also takes effect at the unicellular level. The experimental observations indicate that receptor ‘memory’, induced in Tetrahymena by hormonal imprinting, has certain common features with the neuronal memory of higher organisms.
Regional Distribution of Polyadenylated mRNA in Xenopuslaevis Embryos
Authors: De Bernardi Fiorenza
Published: October 2008

Xenopus laevis embryos were dissected into dorsal and ventral regions in post-gastrula stages. Polyadenylated and nonpolyadenylated ribonucleic acids were separated on oligo (dT) cellulose and translated in vitro. The radioactivity incorporated into the translation products directed by polyadenylated and nonpolyadenylated messenger ribonucleic acids shows that in the dorsal region most proteins are synthesized on polyadenylated messenger ribonucleic acid templates in all the stages, while in the ventral region the major templates seem to be, until the neural fold stage, nonpolyadenylated messenger ribonucleic acids. Later the polyadenylated messenger ribonucleic acid activity there too increases.
Amyloidosis Development in LLC Mice
Authors: Chai Chen K. , Lerner Charles
Published: October 2008

Using electron microscopy and the protein A-gold labelling technique we studied amyloidosis in the LLC mice, an inbred strain developing amyloidosis spontaneously. We found that the reticular cells lining around the sinuses in the red pulp of the spleen were converted to amyloid. Evidence suggests that the amyloid originates in the cells themselves. The process of amyloid formation is discussed.
Morphologic Alterations in Cultured Human Synovial Fibroblasts Induced by Blood Mononuclear Cells
Authors: Heino Jyrki , Viander Markku , Kouri Timo
Published: October 2008

Effects of peripheral blood mononuclear cells on cultured synovial fibroblasts were studied. When mononuclear cells from normal or rheumatoid blood were incubated on synovial fibroblast cultures, a part of the cells adhered to the fibroblasts. They were mainly T lymphocytes but also some B lymphocytes and monocytes. After a 10-hour incubation, adhered mononuclear cells induced morphologic alterations to synovial fibroblasts: appearance of stellate cells and thinning and branching of fibroblasts. No changes were seen when the cells were incubated in the presence of indomethacin. Cytotoxicity of peripheral blood mononuclear cells from 8 rheumatoid patients was also tested against three rheumatoid and three normal synovial fibroblast strains. Only 2 out of 48 combinations were cytotoxic. The potentially cytotoxic mononuclear cells were bound equally well to rheumatoid and control synovial fibroblast cultures.
Metabolic Activation of Procarcinogens to Genotoxic Products in Cultured Rat Liver Cells
Authors: Murison G L. , Hall S D. , Lee A M.
Published: October 2008

A recently established rat liver cell line, RL-12, exhibits an unusually high sensitivity to the genotoxic effects of a number of selected procarcinogens. Significant reductions in cell survival (D37%) and induction of sister chromatid exchanges were obtained with 1 × 10–9M benzo[a]pyrene and 2 × 10–8M 7,12-dimethylbenz[a]anthracene. This rat liver epithelial cell line may serve as a useful model system to study the metabolic activation of procarcinogens to their ultimate genotoxic form.
Sulfated Polysaccharides and Cell Differentiation in the Sea Urchin Embryo
Authors: Løvtrup-Rein Huguette , Løvtrup Søren
Published: October 2008

The synthesis of sulfated polysaccharides during the embryonic development of Paracentrotus lividus has been investigated by incorporation of radioactive sulfate, glucose, glucosamine and fucose. The following substances become labelled: fucan sulfate (∼60%), heparan sulfate (∼20%) and dermatan sulfate (∼20%), and possibly a very slight amount of chondroitin sulfate. In animalized and vegetalized embryos, the rate of incorporation is significantly reduced, and furthermore dermatan sulfate is almost absent in animalized embryos. It is concluded that this substance is associated with the differentiation of vegetative cells, possibly the mesenchyme cells.
A Study of the Adhesive, Locomotory and Invasive Behaviour of Walker 256 Carcinosarcoma Cells
Authors: Elvin Paul , Wong Voishim , Evans Clive W.
Published: October 2008

We have succeeded in selecting two variant strains of the Walker 256 carcinosarcoma which display markedly different adhesive properties. Both the high (W256A) and the low (W256S) adhesive variants respond chemotactically towards 10-8M f-met-leu-phe (FMLP) although there is a significant difference in their locomotory ability. Nevertheless, the fact that the essentially non-adherent W256S cells can migrate in vitro argues against any simple relationship between adhesion and locomotion. We suggest that traction is important in locomotion but that it need not arise only from direct adhesive interaction. We have also tested the invasive behaviour of the W256 variants using an in vitro model system in which disruption of a cellular barrier by the invasive cells can be recorded electrophysiologically. Although leucocytes can penetrate such a barrier they do so only under chemotactic stimulation, whereas W256 tumour cells of either variant strain will do so spontaneously. The tumour variants induce cell retraction within the barrier and this may lead ultimately to cell detachment and death. The holes which arise may then be colonized by tumour cells, and in this way the invasive process could be promoted. The molecular mechanisms by which tumour cells achieve destruction of the cellular barrier are not clear, but it is likely that a number of enzymes are involved.
EDTA Separation and Recombination of Epithelium and Connective Tissue of Human Oral Mucosa
Authors: Holmstrup Palle , Dabelsteen Erik , Harder Flemming
Published: October 2008

A possible epithelial-mesenchymal interaction in determining epithelial histologic features of human oral mucosa was examined. The study comprised 74 biopsies of normal buccal mucosa and 54 biopsies of normal palatal mucosa. Epithelium was separated from connective tissue by the use of 1 mM ethylenediamine tetraacetate dihydrate. Self-recombined and cross-recombined epithelial and connective tissues and connective tissue sheets alone were transplanted to subcutaneous sites of nude mice. Histologic examination of cross-recombined palatal epithelium/buccal connective tissue transplants showed a change in keratinization pattern but no major change in number of epithelial cell layers as the result of connective tissue influence. Transplanted sheets of connective tissue after growth for 14 days showed that complete separation of biopsies from buccal mucosa had been obtained. However, palatal mucosa had been incompletely separated as evidenced by re-epithelialization of most of the connective tissue transplants. The consequences of the incomplete palatal epithelium-connective tissue separation are discussed.
Acquisition and Clonal Growth of Human Sternal Bone Marrow Obtained Incidental to Open-Heart Surgery
Authors: Wittberg Kathleen Long , De Wall Richard A. , Murphy, Jr. Martin J.
Published: October 2008

The establishment of a convenient method of acquiring ample human bone marrow and the successful growth of hematopoietic precursor cells in standard methylcellulose assay is described. Human sternal marrow curettings were obtained at open-heart surgery. Growth of colonies derived from CFU-gm, BFU-e, and CFU-e was successful. Comparison of the CFU-gm colony production between this and prior studies indicates a consistent mean and range of growth. These results document this to be an efficient source of normal human marrow.
Changes in Histological Differentiation of Human Tumors Transplanted to Athymic Nude Mice: A Morphometric Study
Authors: Sharkey Francis E. , Spicer John H. , Fogh Jørgen
Published: October 2008

Differing conclusions have been reached regarding the phenotypic stability of human tumors transplanted to athymic nude mice. Since previous conflicting studies of tumor histology have been largely subjective, quantitative methodology was applied to an analysis of 13 human adenocarcinoma tumor lines that were originally derived directly from surgical specimens. Glandular differentiation was quantitated, both in the original human tumor (OHT) and in a minimum of 6 serial passages of the nude mouse-grown tumors (MGT), by means of point counting. A significant change in differentiation was noted in 12 lines, with 9 showing a decrease. Variance from the OHT was most commonly noted in the initial MGT, but additional changes were also noted in 8 lines during subsequent passages. Most of the lines also showed increased necrosis in the MGTs. Since histological differentiation and necrosis are related to tumor aggressiveness, it would appear that the predominant tendency was to evolve toward a more malignant phenotype. These changes may mimic those seen in human tumor metastases.
Chlamydia isopodii sp. n., an Obligate Intracellular Parasite of Porcellio scaber
Authors: Shay Michael T. , Bettica Annemarie , Vernon G.M. , Witkus E.R.
Published: October 2008

In an ultrastructural study of the hepatopancreas of Porcellio scaber, an obligate intracellular parasite, Chlamydia, was noted in the epithelial cells. Although the infection was found to extend the entire length of the hepatopancreas, it was most extensive in the glandular region. Indirect immunofluorescence testing revealed no cross-reactivity with either lymphogranuloma venereum or psittacosis antisera.