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2.
Med Radiol (Mosk) ; 35(2): 20-2, 1990 Feb.
Artigo em Russo | MEDLINE | ID: mdl-2314199

RESUMO

Thermography of the breast with pharmacological GTT was performed in 260 women; cancer was diagnosed in 150 of them, benign breast diseases in 110. A significant increase in temperature asymmetry after GTT was shown in breast cancer patients as compared to patients with benign diseases. Data on the sensitivity of the mammographic and thermographic methods to identify risk groups were presented.


Assuntos
Neoplasias da Mama/diagnóstico , Teste de Tolerância a Glucose , Glucose , Termografia/métodos , Adulto , Idoso , Doenças Mamárias/diagnóstico , Neoplasias da Mama/epidemiologia , Diagnóstico Diferencial , Feminino , Humanos , Mamografia , Pessoa de Meia-Idade , Fatores de Risco , Termografia/instrumentação
3.
Biokhimiia ; 54(11): 1857-65, 1989 Nov.
Artigo em Russo | MEDLINE | ID: mdl-2627554

RESUMO

Using reverse phase ion pair high performance liquid chromatography, the levels of free adenosine, inosine, adenine, xanthine, hypoxanthine, guanine and deoxycytidine in thymocytes and splenic T- and B-lymphocytes of C3HA mice, were studied under normal conditions and at different times (5 hrs, 1, 2, 3, 4, 5, 8 and 20 days) after transplantation of solid hepatoma 22a. The adenosine and inosine levels in thymus and spleen lymphocytes were 5 to 10 times as low as that of purine bases. Inosine was totally absent in T-and B-lymphocytes. The absolute content of adenine and guanine in thymus and spleen lymphocytes was higher compared to purine bases. It was shown that in all cases studied the decrease in hypoxanthine, xanthine and guanine levels in T- and B-lymphocytes during maximal tumour growth, i.e., on the 5th and 8th post-inoculation days as well as at the terminal period (20th day), was correlated with the decrease in the adenosine deaminase and functional activities of these cells. The level of free adenine in thymocytes and spleen T-lymphocytes during tumour growth showed a 2-4-fold increase in comparison with normal values. A dramatic decrease of intracellular concentration of deoxycytidine was observed in thymocytes and spleen T- and B-lymphocytes beginning with the 5th hour and over the whole subsequent period. The key role of the deoxycytidine decline during tumour growth as a possible cause of simultaneous impairment of DNA synthesis and purine deoxyribonucleoside phosphorylation in lymphocytes is discussed.


Assuntos
Neoplasias Hepáticas Experimentais/metabolismo , Nucleosídeos de Purina/metabolismo , Nucleosídeos de Pirimidina/metabolismo , Baço/metabolismo , Timo/metabolismo , Adenina/metabolismo , Adenosina/metabolismo , Animais , Linfócitos B/metabolismo , DNA de Neoplasias/biossíntese , Desoxicitidina/metabolismo , Guanina/metabolismo , Hipoxantina , Hipoxantinas/metabolismo , Inosina/metabolismo , Camundongos , Camundongos Endogâmicos C3H , Linfócitos T/metabolismo , Fatores de Tempo , Xantina , Xantinas/metabolismo
4.
Biokhimiia ; 54(10): 1673-80, 1989 Oct.
Artigo em Russo | MEDLINE | ID: mdl-2481507

RESUMO

The changes in the biochemical parameters of peritoneal macrophages and their coupling to the secretory and phagocytic functions in CH3A mice during the growth of the reinoculated solid hepatoma 22a were studied. The DNA and RNA synthesis during the active tumour growth was more intense than that in resident macrophages. The activity of uridine kinase increased up to 156.0 +/- 12.0 nmol/hour/10(8) but was absent in resident macrophages. This was accompanied by a 7.2-fold increase of interleukin-1 synthesis as determined by the [3H]thymidine incorporation into thymocyte DNA in response to concanavalin A administration to C3H mice. Similar changes were observed in peptone-stimulated macrophages. A specific feature of macrophages from tumour-bearing mice was the impairment of activity of purine exchange enzymes and the efficiency of phagocytosis that were unobserved in peptone-stimulated macrophages. The activity of adenosine deaminase and purine nucleoside phosphorylase was inhibited as a result of their preincubation with zymosan, a phagocytosis-stimulating agent. This was accompanied by a significant decrease of the first chemiluminescence peak resulting from disturbances in Fc-reception. Macrophages of tumour-bearing animals possessed an increased 2.2-fold activity of membrane-bound AMP 5'-nucleotidase concomitant with the lack or decrease of the amplitude of the second chemiluminescence peak reflecting the disturbances in digestion resulting from phagocytosis.


Assuntos
5'-Nucleotidase/metabolismo , Adenosina Desaminase/metabolismo , DNA/biossíntese , Neoplasias Hepáticas Experimentais/enzimologia , Macrófagos/enzimologia , Nucleosídeo Desaminases/metabolismo , Pentosiltransferases/metabolismo , Purina-Núcleosídeo Fosforilase/metabolismo , RNA/biossíntese , Animais , Membrana Celular/metabolismo , Neoplasias Hepáticas Experimentais/metabolismo , Neoplasias Hepáticas Experimentais/patologia , Medições Luminescentes , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C3H , Fagocitose , Uridina Quinase/metabolismo
5.
Biull Eksp Biol Med ; 108(7): 81-3, 1989 Jul.
Artigo em Russo | MEDLINE | ID: mdl-2478211

RESUMO

Expression of some genes in the brain of ascitic hepatoma of Zajdela bearing rats was compared with that of control animals using Northern blot hybridization technique. The differences revealed were: an increased expression of actin gene and decreased expression of hsp70 gene in the brain of tumor-bearing animals.


Assuntos
Encéfalo , Expressão Gênica , Neoplasias Hepáticas Experimentais/genética , Actinas/genética , Animais , Northern Blotting , Masculino , Hibridização de Ácido Nucleico , RNA , Ratos
6.
Biull Eksp Biol Med ; 106(8): 217-20, 1988 Aug.
Artigo em Russo | MEDLINE | ID: mdl-3416058

RESUMO

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.


Assuntos
Benzo(a)pireno/farmacologia , Dano ao DNA , Replicação do DNA/efeitos dos fármacos , DNA/efeitos dos fármacos , Animais , Benzo(a)pireno/farmacocinética , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Células Cultivadas , DNA/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Regeneração Hepática/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C3H , Ratos
7.
Mol Biol (Mosk) ; 22(4): 1119-27, 1988.
Artigo em Russo | MEDLINE | ID: mdl-3185532

RESUMO

The two types of DNA-matrix complexes (the weak and tight ones, or type I and type II, respectively) identified in our previous work were studied with respect to their involvement in DNA replication. Nuclei isolated from human fibrosarcoma HT1080 cell line were treated with either restriction endonucleases or ultrasonic desintegrator and afterwards subjected to the triple-gradient Nucleoprotein--Celite chromatography. This permitted fractionation of nuclear DNA into fragments not attached, weakly attached, and tightly attached to the nuclear matrix (DNA 0, DNA I, and DNA II, respectively). It was shown that pulse labelled RNA migrates from DNA II fraction where it resides initially to DNA 0 and further to DNA I during the 2 h chase period. This finding allowed us to consider the tight DNA-matrix complex as the replicative one. The experiments aiming to follow the movements of specific DNA sequences (histone genes) in relation to the DNA-matrix attachment sites were conducted on synchronous HT1080 cells progressing through S phase. The histone sequences appeared to undergo similar movements during the first 30 min of S phase. They reside initially in DNA 0 and DNA I fractions, but as soon as DNA synthesis was restored they migrate consequently to DNA II and DNA 0 fractions. This approach can appear to be a useful tool for studying the schedule of replication of specific genes during S phase.


Assuntos
Núcleo Celular/metabolismo , Replicação do DNA , DNA/genética , Nucleoproteínas/genética , Ciclo Celular , Núcleo Celular/ultraestrutura , DNA/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Hibridização de Ácido Nucleico , Nucleoproteínas/metabolismo , Plasmídeos , Células Tumorais Cultivadas
8.
Biull Eksp Biol Med ; 104(12): 720-2, 1987 Dec.
Artigo em Russo | MEDLINE | ID: mdl-3689968

RESUMO

Glycogen content in the brain, liver and skeletal muscles of rats bearing ascite Zajdela hepatoma (AZH) and solid 27 hepatoma (27-H) has been studied. Serum glucose levels directly correlated with liver glycogen reserves. In the terminal stage of tumor growth depletion of liver glycogen was observed, while the stores of muscle glycogen did not diminish. Within 1-4 days (AZH) and 15-30 days (27-H) after implantation the stores even exceeded those of control healthy rats. In the terminal stage, in spite of hypoglycaemia development, the content of brain glycogen was significantly elevated in both groups of animals.


Assuntos
Glicogênio/metabolismo , Neoplasias Hepáticas Experimentais/metabolismo , Estresse Fisiológico/metabolismo , Animais , Glicemia/metabolismo , Química Encefálica , Glicogênio Hepático/metabolismo , Neoplasias Hepáticas Experimentais/sangue , Masculino , Músculos/metabolismo , Ratos , Estresse Fisiológico/sangue
9.
Biull Eksp Biol Med ; 104(11): 615-8, 1987 Nov.
Artigo em Russo | MEDLINE | ID: mdl-2890387

RESUMO

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.


Assuntos
Glucocorticoides/farmacologia , Neoplasias Hepáticas Experimentais/patologia , Neoplasias Hormônio-Dependentes , Animais , Linhagem Celular , Indução Enzimática/efeitos dos fármacos , Técnicas In Vitro , Neoplasias Hepáticas Experimentais/enzimologia , Tirosina Transaminase/metabolismo
10.
Biokhimiia ; 52(11): 1838-46, 1987 Nov.
Artigo em Russo | MEDLINE | ID: mdl-2894228

RESUMO

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.


Assuntos
Hidrocortisona/farmacologia , Fígado/efeitos dos fármacos , Tirosina Transaminase/biossíntese , Adrenalectomia , Animais , Indução Enzimática , Hidrocortisona/metabolismo , Fígado/enzimologia , Neoplasias Hepáticas Experimentais/enzimologia , Masculino , Ratos , Ratos Endogâmicos , Receptores de Glucocorticoides/efeitos dos fármacos , Receptores de Glucocorticoides/metabolismo , Fatores de Tempo , Triptofano/farmacologia
11.
Radiobiologiia ; 27(6): 732-7, 1987.
Artigo em Russo | MEDLINE | ID: mdl-3423224

RESUMO

The growth of djungarian hamster fibroblasts 4/21 is inhibited by 3H-thymidine present in a culture medium in concentrations from 18.5 to 740 KBq/ml. As judged from the gradient elution of DNA from isolated nuclei (the nucleoprotein-celite chromatography), DNA fragmentation increases together with the increase in 3H-thymidine concentration and the decrease in the cell growth rate. DNA fragmentation does not activate the family of heat shock genes (hsp70). On the contrary, the hsp70 gene transcription is somewhat inhibited in both heat shock and non-heat shock conditions even at a concentration of 3H-thymidine of as low as 37 KBq/ml. Hence the 3H labelling of radiosensitive cultured cells can lead to some deviations in cellular processes under study.


Assuntos
Cromatina/efeitos da radiação , DNA/efeitos da radiação , Genes/efeitos da radiação , Marcação por Isótopo , Trítio , Animais , Cricetinae , Fibroblastos/efeitos da radiação , Radiogenética
12.
Biokhimiia ; 52(9): 1501-11, 1987 Sep.
Artigo em Russo | MEDLINE | ID: mdl-3676360

RESUMO

In order to elucidate the peculiarities of brain metabolism in tumour-bearing organisms, the arterio-venous (A-V) content of glucose, acetoacetate (Ac-Ac), beta-hydroxybutyrate (beta-HB) and non-esterified fatty acids (NEFA) in growing Zajdela ascite hepatoma (ZAH) and solid hepatoma 27 (H-27) was compared. Analysis of metabolic patterns of healthy, starving and fed recipients (ZAH and H-27) revealed the inadequacy of the concepts on anorexia as being the cause of carbohydrate-lipid metabolic disturbances. In tumour-bearing organisms lipolysis and ketogenesis reflect the tumour-induced chronic stress. Absorption of beta-HB and release of Ac-Ac by brain were observed at all stages of malignant growth. This is probably due to a partial switch-over of brain metabolism to non-carbohydrate energy sources. Besides, certain stages of tumour growth are associated with active assimilation of NEFA by brain. A correlation between the A-V difference with respect to glucose and Ac-Ac as well as between the glucose and NEFA contents was established. It was assumed that the A-V difference in glucose is the main regulator of ketone body metabolism.


Assuntos
Encéfalo/metabolismo , Corpos Cetônicos/biossíntese , Lipólise , Neoplasias Hepáticas Experimentais/metabolismo , Estresse Fisiológico/metabolismo , Acetoacetatos/sangue , Animais , Glicemia/metabolismo , Doença Crônica , Jejum , Ácidos Graxos não Esterificados/sangue , Hidroxibutiratos/sangue , Neoplasias Hepáticas Experimentais/complicações , Masculino , Ratos , Estresse Fisiológico/etiologia
13.
Biokhimiia ; 52(5): 794-805, 1987 May.
Artigo em Russo | MEDLINE | ID: mdl-3474032

RESUMO

Nuclear RNAs release from nucleoproteins of isolated nuclei absorbed on a celite column in a wide range of dissociating conditions (from 1 M LiCl--2 M urea at 2 degrees C to 4 M LiCl--8 M urea at 70-80 degrees C) was demonstrated. Such a high "adhesive" heterogeneity of nuclear RNAs (i.e., variations in the tightness of RNA-protein bonds) appears to be due to the association of nuclear matrix proteins. A direct correlation was found to exist between the metabolic turnover of RNA and the tightness of its association with the nuclear matrix. Actually, the pulse label which rapidly incorporates into the RNAt greater than 50 degrees, the RNA fraction being most tenaciously bound to the matrix, could be chased later into RNAs weakly bound to it. As the RNA-matrix binding weakens, the metabolic and structural properties of a given RNA change, e.g., sedimentation coefficients decrease, while the poly(A)+-RNA content and stability increase. The "adhesive" heterogeneity was found to be inherent in not only nuclear RNAs but also in cytoplasmic non-ribosomal RNAs, showing the same correlation, i.e., the tighter the RNA--protein complex, the higher the rate of RNA turnover. Cytoplasmic RNAs which differ in their adhesiveness may fulfil various intracellular functions, since polyribosomal mRNPs and informosomal mRNPs appear to be enriched in tightly and weakly bound RNA fractions, respectively. The interrelationships between nuclear and cytoplasmic RNAs are discussed.


Assuntos
Proteínas/isolamento & purificação , RNA Nuclear Heterogêneo/isolamento & purificação , RNA Mensageiro/isolamento & purificação , Adesividade , Animais , Células Cultivadas , Vírus da Leucemia Murina de Friend , Cinética , Leucemia Eritroblástica Aguda/metabolismo , Neoplasias Hepáticas Experimentais/metabolismo , Substâncias Macromoleculares , Peso Molecular , Poli A/análise , Proteínas/metabolismo , RNA Nuclear Heterogêneo/metabolismo , RNA Mensageiro/metabolismo , RNA Neoplásico/isolamento & purificação , Ribonucleoproteínas , Moldes Genéticos
14.
Biokhimiia ; 52(4): 615-24, 1987 Apr.
Artigo em Russo | MEDLINE | ID: mdl-3593792

RESUMO

The protein content in four nuclear fractions was compared. The nuclear fraction of rat liver deficient in active genes was characterized by a very low content of non-histone proteins whose mobility is less than that of histone H1.. The predominant protein of this fraction is an acid-soluble protein (Mr = 41 +/- 1 kD) designated as 41K. This protein was detected in acid nuclear extracts of rat lungs, kidney and spleen but was absent (or practically absent) in four murine and rat hepatomas under study. The decreased content of protein 41K was correlated with the diminution of the content of histone H1(0) fraction. It was shown that proteins HMG 14 and 17 are readily washed off during fractionation of nuclei and they bind to DNA fragments passing into solution irrespective of whether they contain active or inactive genes. The nuclear matrix fraction rich in active genes was heterogeneous according to its protein composition. Differences in the intensity of staining and in electrophoretic mobility of some polypeptides of this nuclear fraction in normal and hepatoma cells were revealed.


Assuntos
Genes , Neoplasias Hepáticas Experimentais/análise , Fígado/análise , Nucleoproteínas/genética , Animais , Cromatina/análise , Proteínas Cromossômicas não Histona/análise , Cricetinae , Eletroforese em Gel de Poliacrilamida , Proteínas de Grupo de Alta Mobilidade/análise , Humanos , Hidrólise , Camundongos , Camundongos Endogâmicos C3H , Nucleoproteínas/isolamento & purificação , Ratos , Ratos Endogâmicos
15.
Eksp Onkol ; 9(4): 66-71, 1987.
Artigo em Russo | MEDLINE | ID: mdl-3678128

RESUMO

The growth of ascitic Zajdela and solid 27 hepatomas in vivo is accompanied by significant changes in parathyroid hormones, calcitonin and aldosterone blood levels. In periods close to terminal ones, their level decreases presumably as a result of energy deficiency in the endocrine glands. The arising hormonal shifts are a result of a "metabolic stress" caused by the growing tumour.


Assuntos
Neoplasias Hepáticas Experimentais/sangue , Desequilíbrio Hidroeletrolítico/sangue , Aldosterona/sangue , Animais , Proteínas Sanguíneas/metabolismo , Calcitonina/sangue , Corticosterona/sangue , Masculino , Transplante de Neoplasias , Hormônio Paratireóideo/sangue , Ratos
16.
Eksp Onkol ; 9(6): 62-7, 1987.
Artigo em Russo | MEDLINE | ID: mdl-3436292

RESUMO

The levels of growth hormone (GH) in the blood of rats with ascite Zajdela hepatoma and hepatoma 27 (H-27) are shown to increase during the tumour growth. Stimulation of the GH secretion is a result of the hypoglycaemic stress. An increase in the blood GH secretion is also observed in the fasting rats. To reveal the predominance of catabolic GH effects over the anabolic ones in the tumour host determination of the molar insulin/GH ratio in the blood is suggested. A direct correlation is found between reduction of this index, glycaemia and the content of liver glycogen. A short-term induced hyperglycaemia evokes a paradoxical reaction in terms of GH secretion. In contrast to control fasting rats, in tumour-bearing animals no correlation between thyrotropin and thyroxine blood concentration could be observed. Anaemia increasing progressively in the course of the tumour growth may be the cause of the above phenomenon.


Assuntos
Glicemia/metabolismo , Hormônio do Crescimento/sangue , Neoplasias Hepáticas Experimentais/metabolismo , Tireotropina/sangue , Tiroxina/sangue , Animais , Jejum , Hematócrito , Neoplasias Hepáticas Experimentais/sangue , Masculino , Ratos
17.
Neoplasma ; 34(4): 453-67, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3498909

RESUMO

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.


Assuntos
Linfócitos B/metabolismo , Neoplasias Hepáticas Experimentais/sangue , Linfócitos T/metabolismo , Adenosina Desaminase/sangue , Animais , Formação de Anticorpos , Linfócitos B/imunologia , Corticosterona/sangue , DNA de Neoplasias/biossíntese , Desoxirribonucleotídeos/sangue , Eritrócitos/imunologia , Neoplasias Hepáticas Experimentais/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C3H , Ovinos , Linfócitos T/imunologia , Timidina Quinase/sangue
18.
Arkh Patol ; 49(6): 10-8, 1987.
Artigo em Russo | MEDLINE | ID: mdl-3310967

RESUMO

Several physiological, biochemical, and molecular biological approaches to the study of factors determining immunodepression in tumor-bearing animals are considered. Cancer cells release substances of nucleic and peptide nature that suppress the functional activity of macrophages and lymphocytes and stimulate cell proliferation in organs and tissues of the host. Suppressor T cells capable of inhibiting the function of helper T cells and impairing the differentiation of killer T cells are activated. The suppression of T- and B-cell-mediated immunity in the tumor host involves disturbances of nucleic acid metabolism in those cells as well as hypersecretion of glucocorticoids. The impairments of lymphocyte proliferation and differentiation that result in reduced immune responsiveness are attributable to drastic alterations in the metabolism of purine and pyrimidine nucleotides and to the damage sustained by the lymphocyte's DNA.


Assuntos
DNA/metabolismo , Tolerância Imunológica , Tecido Linfoide/imunologia , Síndromes Paraneoplásicas/imunologia , Animais , Linfócitos B/imunologia , Linfócitos B/metabolismo , Homeostase , Humanos , Imunidade Celular , Tecido Linfoide/metabolismo , Síndromes Paraneoplásicas/metabolismo , Peptídeos/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo
19.
Vopr Med Khim ; 32(4): 117-22, 1986.
Artigo em Russo | MEDLINE | ID: mdl-3020791

RESUMO

Activities of key enzymes of purine metabolism [adenosine deaminase (AD); purine nucleoside phosphorylase (PNP); 5'-nucleotidase] were studied; changes in DNA content, nucleus ploidity in thymocytes, T- and B-lymphocytes in the C3HA mouse spleen during solid 22 hepatoma growth and after the immunization were monitored. Immunological properties of lymphocytes were also investigated measuring antibody formation and the reaction of blasttransformation in response to phytohemagglutinin, concanavalin A and lipopolysaccharide. Within the first 48 hrs after the tumor implantation and immunization certain nonspecific biochemical mechanisms of lymphocytes activation (elevated AD activity, decreased activity of 5'-nucleotidase, augmented intracellular DNA levels, polyploidity) were revealed. As the solid 22 hepatoma reached the maximum growth rate specific alterations in the activities of the purine metabolism key enzymes were observed reflecting the response of thymus and spleen lymphocytes to the presence of the malignant tumor.


Assuntos
Imunização , Neoplasias Hepáticas Experimentais/metabolismo , Linfócitos/metabolismo , Baço/metabolismo , Timo/metabolismo , 5'-Nucleotidase , Adenosina Desaminase/metabolismo , Animais , Células Produtoras de Anticorpos/imunologia , DNA/análise , DNA de Neoplasias/análise , Eritrócitos/imunologia , Neoplasias Hepáticas Experimentais/enzimologia , Neoplasias Hepáticas Experimentais/imunologia , Ativação Linfocitária , Linfócitos/enzimologia , Linfócitos/imunologia , Camundongos , Camundongos Endogâmicos C3H , Nucleotidases/metabolismo , Ploidias , Purina-Núcleosídeo Fosforilase/metabolismo , Ovinos , Baço/enzimologia , Baço/imunologia , Timo/enzimologia , Timo/imunologia
20.
Biokhimiia ; 51(6): 931-6, 1986 Jun.
Artigo em Russo | MEDLINE | ID: mdl-3015263

RESUMO

The entering of T-lymphocytes into the DNA-synthesizing phase was marked by three consecutive signals, i.e., antigenic influence, interleukin-2, a specific T-lymphocyte cell growth factor, and non-specific serum growth-promoting factors, in the first place, transferrin. This system was used for the study of effects of virus SV40 T-antigen on cell mitotic cycle. Purified T-antigen was injected consecutively into T-lymphocytes, using erythrocyte ghost vesicles instead of one of control signals. It was shown that T-antigen cannot simulate the antigenic response but simulates the effect of interleukin-2, a specific growth-promoting factor. However, both normally proliferating T-lymphocytes and T-antigen-induced lymphocytes showed an absolute requirement for transferrin and, apparently, for other nonspecific growth-promoting factors. It was assumed that the polymorphism of tumours induced by papovaviruses is determined by the ability of their "early" proteins to imitate the effects of their specific growth-promoting factors on the cells.


Assuntos
Antígenos Virais de Tumores/imunologia , Interleucina-2/imunologia , Vírus 40 dos Símios/imunologia , Linfócitos T/imunologia , Linhagem Celular , Humanos , Técnicas In Vitro , Ativação Linfocitária
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