RESUMEN
A continuous-action CO2 laser of 15-20 W was used in 358 females on the treatment of largely benign or precancerous conditions of the cervix and external genitalia. The procedure is painless and produces no side-effects. There is no associated edema, bleeding or leukorrhea. The healing is fairly rapid and not accompanied by the development of secondary scars; menstrual and reproductive functions are not affected, so the method can be used in nulliparous women. Pre- and post-treatment control was made by means of colposcopic, cytologic, bacterioscopic, bacteriologic and histologic methods.
Asunto(s)
Enfermedades de los Genitales Femeninos/cirugía , Terapia por Láser/instrumentación , Instrumentos Quirúrgicos , Adolescente , Adulto , Anciano , Dióxido de Carbono , Femenino , Humanos , Persona de Mediana Edad , Cicatrización de HeridasRESUMEN
The nuclei of cells from regenerating rat liver were incubated with benzo(a)pyrene and the concentrations of the metabolites that covalently bound to DNA of different nuclear fractions were compared. It appeared that DNA associated with nuclear matrix (containing replicating DNA) is modified most intensively. The synchronized mouse embryo cells were incubated with benzo(a)pyrene during S phase and the levels of modifications in short and long single-stranded DNA fragments were compared. It has been observed that replicating DNA is represented in short fragments. These short DNA fragments were found to be modified by benzo(a)pyrene 4-9 times more intensively than total DNA. The possible mechanisms of both the increase in the number of DNA modifications in proliferating cells and the reason for the enhancement of carcinogenic effect on dividing cells are being discussed.
Asunto(s)
Benzo(a)pireno/farmacología , Daño del ADN , Replicación del ADN/efectos de los fármacos , ADN/efectos de los fármacos , Animales , Benzo(a)pireno/farmacocinética , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Células Cultivadas , ADN/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Regeneración Hepática/efectos de los fármacos , Ratones , Ratones Endogámicos C3H , RatasRESUMEN
Glucocorticoids induce tyrosine aminotransferase synthesis in 7777 Morris hepatoma but fail to do so in Zajdela hepatoma. This internal property indicates the resistance to the hormone. However, both hepatoma cell lines do respond to the triamcinolone acetonide in a similar way, as judged by some other criteria, e. g. interaction with the immobilized hormone on the inert carrier, adhesion to glass and kinetic parameters of alkaline phosphodiesterase I activity. Moreover, both cell types respond to glucocorticoids by modification of synthesis of some proteins, as revealed previously by two-dimensional electrophoresis. The results show that in case of tumour cells which retain their specific receptor apparatus but do not respond to glucocorticoids by usual criteria, the conclusion whether tumour cells are hormone-sensitive or not has to be drawn from the analysis of their multiple response judging by several assays.
Asunto(s)
Glucocorticoides/farmacología , Neoplasias Hepáticas Experimentales/patología , Neoplasias Hormono-Dependientes , Animales , Línea Celular , Inducción Enzimática/efectos de los fármacos , Técnicas In Vitro , Neoplasias Hepáticas Experimentales/enzimología , Tirosina Transaminasa/metabolismoRESUMEN
The mechanisms of reversible decrease of hormone-dependent induction of tyrosine aminotransferase (TAT) by rat liver cells after prolonged administration of the glucocorticoid was studied. It was shown that the main links of the glucocorticoid action mechanism (i.e., the formation of a cytoplasmic hormone-receptor complex and the hormone accumulation in the nuclei) do not change under these conditions. It was found also that one of the necessary prerequisites for the decrease of the hormone-dependent induction of TAT is the constant production by liver cells of large amounts of TAT irrespective of whether this process is induced by the glucocorticoid or by a non-hormonal inducer, e.g., tryptophan. Using the dot-hybridization technique, it was demonstrated that the inhibition of hormone-dependent induction of TAT is correlated with the reduction of mRNA TAT. It was supposed that the main links in the mechanism of inhibition of the hormone-dependent induction are the formation of a large excess of the inducible protein--TAT--in the cells as well as the accumulation of end products of the TAT-catalyzed transamination reaction which cause a feed-back repression of the de novo synthesis of TAT. Studies with cell cultures of Morris hepatoma which is known to be sensitive to glucocorticoids revealed the ability of glucose, the end product of gluconeogenesis reactions, to provide for selective inhibition of the hormone-induced accumulation of mRNA TAT in hepatoma cells.
Asunto(s)
Hidrocortisona/farmacología , Hígado/efectos de los fármacos , Tirosina Transaminasa/biosíntesis , Adrenalectomía , Animales , Inducción Enzimática , Hidrocortisona/metabolismo , Hígado/enzimología , Neoplasias Hepáticas Experimentales/enzimología , Masculino , Ratas , Ratas Endogámicas , Receptores de Glucocorticoides/efectos de los fármacos , Receptores de Glucocorticoides/metabolismo , Factores de Tiempo , Triptófano/farmacologíaRESUMEN
In thymocytes of C3HA mice carrying the transplantable and ortoaminoazotoluene induced hepatomas at the time of their intense growth a drastic decrease in adenosine deaminase activity set in and 3-4-fold augmentation of intracellular concentration of dATP and dGTP, potential inhibitors of ribonucleoside diphosphate reductase was observed, leading to the reduction of the DNA synthesis. The latter event was evidenced by a suppressed 14C-thymidine incorporation into thymocytes DNA in vitro, decreased thymidine kinase activity, intracellular dTTP and depletion of dCTP pools. Only in the terminal period of hepatocarcinogenesis (12 months) a 4-fold increase in the corticosterone serum concentration was observed. As for the mice carrying transplantable 22a hepatoma, serum hormone levels augmented 4-fold as early as 24 h after tumor implantation and thereafter kept increased two fold. An elevated activity of terminal deoxynucleotidyl transferase in mouse thymocytes has been shown to be characteristic of the late periods of tumor growth reflecting the arrest of the immature cortical thymocyte differentiation. By the time hepatomas emerged in the course of hepatocarcinogenesis in spleen T and B lymphocytes a significant drop in the activity of adenosine deaminase (3-4-fold) and purine nucleoside phosphorylase (2-8-fold) was noted--the events directly correlated with the weakening of cell immune functions. The disorders described were accompanied by the accumulation of dGTP in spleen T lymphocytes, dATP in B lymphocytes and inhibition of DNA synthesis, predominantly in T lymphocytes. In the latter instance the pool of dCTP was found to be depleted. In spleen T and B lymphocytes of mice carrying solid 22a hepatoma when the peak of its growth was reached (day 5) the rate of DNA synthesis dropped. Later on (from day 8 to the animal death), however, in spite of the suppression of immune function and the decrease in adenosine deaminase activity a drastic stimulation of DNA synthesis in spleen T and B lymphocytes was observed. The increase in spleen T suppressor activity in the course of intense growth of the both types of hepatomas coincided in the time with the stimulation of the CTP-dependent thymidine kinase isoenzyme activity in total T lymphocyte population of the same organ.
Asunto(s)
Linfocitos B/metabolismo , Neoplasias Hepáticas Experimentales/sangre , Linfocitos T/metabolismo , Adenosina Desaminasa/sangre , Animales , Formación de Anticuerpos , Linfocitos B/inmunología , Corticosterona/sangre , ADN de Neoplasias/biosíntesis , Desoxirribonucleótidos/sangre , Eritrocitos/inmunología , Neoplasias Hepáticas Experimentales/inmunología , Masculino , Ratones , Ratones Endogámicos C3H , Ovinos , Linfocitos T/inmunología , Timidina Quinasa/sangreRESUMEN
Biochemical impairments in spleen immunocompetent cells (T- and B-lymphocytes) were revealed in host (C3HA mice) of transplantable and ortoaminoazotoluol-induced hepatomas in the course of their growth. As soon as hepatoma emerged (chemical carcinogenesis), the activity of adenosine deaminase and purine nucleoside phosphorylase in T- and B-lymphocytes were found to be reduced 2-6 and 7-10-fold, respectively in parallel with the impairment of their immune system. These alterations were accompanied by the increase in concentrations of dGTP in T-lymphocytes (5.4-fold) and of dATP in B-lymphocytes (4-fold) as well as with the inhibition of DNA synthesis, predominantly in T-lymphocytes. In both T- and B-lymphocytes, the dCTP pool was decreased. In the spleen, T- and B-lymphocytes of mice carrying transplantable 22 hepatoma 22 by the moment of its maximal growth (5th day), the DNA synthesis was inhibited as revealed by the reduction of (a) thymidine kinase activity, (b) rate of the labeled thymidine incorporation into DNA, and (c) intracellular dTTP and dCTP concentrations. In latter periods (from 8th day up to the moment of death), drastic stimulation of DNA synthesis in spleen T- and B-lymphocytes was observed irrespective of the impairments in the immune function and the decrease of the adenosine deaminase activity. In the course of growth of both transplantable and induced solid hepatomas in host spleen T- lymphocytes, the activity of the CTP-dependent thymidine kinase isoenzyme increased, coinciding in time with the activation of antigen-specific T-suppressors in the same organ.
Asunto(s)
Linfocitos B/metabolismo , ADN de Neoplasias/biosíntesis , Glucocorticoides/farmacología , Neoplasias Hepáticas Experimentales/metabolismo , Nucleótidos de Purina/biosíntesis , Bazo/metabolismo , Linfocitos T/metabolismo , Adenosina Desaminasa/metabolismo , Inhibidores de la Adenosina Desaminasa , Animales , Células Productoras de Anticuerpos/inmunología , Linfocitos B/enzimología , Linfocitos B/inmunología , Resistencia a Medicamentos , Neoplasias Hepáticas Experimentales/inducido químicamente , Neoplasias Hepáticas Experimentales/inmunología , Masculino , Ratones , Ratones Endogámicos C3H , Purina-Nucleósido Fosforilasa/antagonistas & inhibidores , Purina-Nucleósido Fosforilasa/metabolismo , Bazo/enzimología , Bazo/inmunología , Linfocitos T/enzimología , Linfocitos T/inmunología , Timidina/metabolismo , Timidina Quinasa/antagonistas & inhibidores , Timidina Quinasa/metabolismo , Factores de TiempoRESUMEN
Some biochemical mechanisms underlying the impairments of cellular immunity were studied in C3Ha mice in the course of growth of transplantable and induced (ortoaminoazotoluol) solid hepatomas. During intensive hepatoma growth, the adenosine deaminase activity in host thymocytes was shown to be drastically (6 times) reduced, resulting in the elevation of dATP and dGTP concentrations (6- and 7-fold, respectively), the potential inhibitors of ribonucleoside diphosphate reductase. Consequently, the rate of DNA synthesis was reduced as can be evidenced by the decrease of (a) thymidine kinase activity, (b) 14C-thymidine incorporation into DNA, and (c) dTTP and dCTP pools. By the terminal period of hepatoma growth (both transplantable and induced one), the serum corticosterone content increased 3- and 8-fold, respectively. At the same time, specific binding of [3H]triamsinolone acetonide by thymocytes was augmented and the activity of terminal deoxynucleotidyl transferase increased the latter alterations, which can be regarded as a reflection (including other parameters mentioned) of the arrest of T-lymphocyte differentiation at the level of immature cortex thymocytes.
Asunto(s)
Corticosterona/sangre , ADN de Neoplasias/biosíntesis , Neoplasias Hepáticas Experimentales/inmunología , Nucleótidos de Purina/metabolismo , Linfocitos T/inmunología , Adenosina Desaminasa/metabolismo , Animales , ADN Nucleotidilexotransferasa/metabolismo , Tolerancia Inmunológica , Inmunidad Celular , Inmunización , Neoplasias Hepáticas Experimentales/inducido químicamente , Neoplasias Hepáticas Experimentales/metabolismo , Ratones , Ratones Endogámicos C3H , Purina-Nucleósido Fosforilasa/metabolismo , Linfocitos T/enzimología , Linfocitos T/metabolismoRESUMEN
The resistance of Morris hepatoma cells strain 8994 to glucocorticoids which lack hormonal induction of tyrosine aminotransferase synthesis was studied. The cells of Morris hepatoma 7777 were used as a sensitive strain by a criterion of the enzyme synthesis. Using two-dimensional polyacrylamide gel electrophoresis, it was demonstrated that, i) in the cells of the "resistant" Morris hepatoma strain 8994 glucocorticoids change the rate of synthesis of at least five proteins, ii) two of these proteins are common for both cell strains, while the other ones are individual for each line, iii) in the cells of Morris hepatoma 8994 tyrosine aminotransferase is not controlled by glucocorticoids, iiii) glucocorticoids may not only control the activated genes but also the genes whose expression is suppressed. It was assumed that in the absence of disturbances in the receptor apparatus the resistance of any cell population to glucocorticoids can only be established by the use of a great variety of experimental approaches. The resistance of a cell population to the hormones cannot be judged upon by an analysis of the intensity of synthesis of one or even several proteins.
Asunto(s)
Glucocorticoides/farmacología , Neoplasias Hepáticas Experimentales/enzimología , Tirosina Transaminasa/genética , Animales , Línea Celular , Resistencia a Medicamentos , Inducción Enzimática , Genes/efectos de los fármacos , Cinética , Neoplasias Hepáticas Experimentales/fisiopatología , RatasRESUMEN
The maximal amount of specifically bound triamsinolone acetonide (TA) penetrates into Morris hepatoma cells at initial steps of hormonal induction. This amount is gradually decreased during incubation of the cells with the hormone. As the incubation time rises, the inhibition of [3H]TA binding to the nuclear fraction induced by an excess of the non-labelled hormone is further decreased, which is paralleled with deceleration of the [3H]TA efflux from the nuclei to a hormone-free medium. After removal of the hormone the cells retain their ability to induce the synthesis of tyrosine aminotransferase for 10 hours, although after 3 hours the amount of the bound hormone falls down to 20-25% of the original level. The rate of further deinduction of tyrosine aminotransferase synthesis depends on the incubation time, i.e. in the cells preincubated with TA for 10 min the deinduction occurs at a slower rate than in the cells preincubated with the hormone for 48 hours. The increase in the amount of specifically bound TA 10 min after hormone addition leads to augmented synthesis of tyrosine aminotransferase which surpasses the synthesis providing for the maintenance of maximal induction. An addition of actinomycin D to a hormone-free medium containing the cells preincubated with TA for 48 hours prevents the deinduction. It is assumed that Morris hepatoma cells contain an actinomycin D-sensitive feed-back mechanism which controls the concentration and distribution of specifically bound intranuclear TA depending on hormonal response.
Asunto(s)
Neoplasias Hepáticas Experimentales/metabolismo , Receptores de Glucocorticoides/metabolismo , Receptores de Esteroides/metabolismo , Triamcinolona Acetonida/metabolismo , Animales , Transporte Biológico , Línea Celular , Dactinomicina/farmacología , Inducción Enzimática , Cinética , Ratas , Triamcinolona Acetonida/farmacología , Tirosina Transaminasa/genéticaRESUMEN
The [3H]hydrocortisone transfer into intact target cells and into non-target cells, e. g. isolated hepatocytes, hormone-sensitive Morris hepatoma 7777 cells, hormone-resistant Zajdela ascite hepatoma cells, was studied. In target cells the glucocorticoid transfer is temperature-dependent, i. e. the curve for hormone binding by the cells at increasing concentrations shows a plateau Phospholipase A2 and neuraminidase decrease the ability of the cells to incorporate the labelled hormone. The experimental data differ significantly from those obtained for target cell cytosol and for intact Zajdela hepatoma cells. It was assumed that in target cells the crucial role in hormone transfer into the cells belongs to plasma membranes, while in non-target cells the hormone penetrates inside the cells by passive diffusion.
Asunto(s)
Hidrocortisona/metabolismo , Neoplasias Hepáticas Experimentales/metabolismo , Animales , Transporte Biológico , Membrana Celular/metabolismo , Cinética , Masculino , RatasRESUMEN
It was found that isolated plasma membranes whose purity was assayed by determinations of marker enzyme activities, specifically bind dexamethasone. The association constant and the number of binding sites were found to be equal to (7,03 +/- 4,05) . 10(9) M-1 and (1,6 +/- 0,18) . 10(-14) mol/mg protein, respectively. It was assumed that lipoprotein components of plasma membranes are involved in this binding.
Asunto(s)
Hígado/metabolismo , Receptores de Glucocorticoides/metabolismo , Receptores de Esteroides/metabolismo , Animales , Membrana Celular/metabolismo , Dexametasona/metabolismo , Cinética , Lipoproteínas/análisis , Masculino , RatasRESUMEN
Temperature-activation of the hormone-receptor complex (HRC) was shown to be necessary to ensure its translocation from cytoplasm to nucleus both in the rat liver and hepatoma. Hepatoma nuclei bind 20 times less HRC derived from homologous hepatoma cytosol (0.15 pmol/mg DNA), but twice as much (5.6 pmol/mg DNA) of HRC from heterologous liver cytosol, as compared with the binding of HRC from normal liver cytosol by liver nuclei (3 pmol/mg DNA), Ka of HRC with the acceptor sites in hepatoma and liver nuclei were found to be practically of the same order of magnitude. The above findings suggest an inhibition of cytosol-nucleus translocation of HRC from the cytosol of hepatoma cells as a possible cause of the nonresponsiveness of the latter to the hormone.
Asunto(s)
Dexametasona/metabolismo , Neoplasias Hepáticas Experimentales/ultraestructura , Hígado/ultraestructura , Receptores de Superficie Celular/metabolismo , Animales , Sitios de Unión , Núcleo Celular/metabolismo , Citosol/análisis , Técnicas In Vitro , Cinética , Hígado/metabolismo , Neoplasias Hepáticas Experimentales/metabolismo , Masculino , Ratas , Receptores de Superficie Celular/aislamiento & purificaciónRESUMEN
Specific dexametasone (D) and cortisol (F) receptors have been found both in liver and Zajdela hepatoma. Rat liver cytosol receptors are characterized by the association constant (Kas) = 3,8 X 10(8) M-1 for D and 0,57 X 10(8) M-1 for F as well as by a number of binding sites (NBS)=4,9 X 10(-13) moles/mg protein and 4,06 X 10(-13) moles/mg protein, respectively. The receptors show stric specificity to glucocorticoids. Cytosol glucocorticoid-receptor complexes from liver and hepatoma sediment at 6-7S, when centrifuged in the buffer of a low ionic strength, and at 3-4S in the buffer of a high ionic strength (0,4 M KCl). The properties of cytosol receptors in the course of in vivo hepatoma growth were found to be gradually altering: Kas for D dropped whereas that for F increased; the NBS is decreased 3-4 fold as compared to normal liver cytosol--which may partially be accounted for by the unresponsiveness of the tumour to the hormones.