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1.
Med Klin Intensivmed Notfmed ; 108(3): 223-33, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23455443

RESUMO

INTRODUCTION: The optimal nutritional strategy remains controversial, particularly in severely septic patients. Our aim was to analyze the effect of three nutritional strategies--enteral (EN), parenteral (PN), and combined nutrition (EN+PN)--on the outcome of patients with severe sepsis or septic shock. PATIENTS AND METHODS: This secondary analysis of the prospective, randomized-controlled, multicenter "Intensive Insulin Therapy and Pentastarch Resuscitation in Severe Sepsis (VISEP)" trial only included patients with a length of stay in the intensive care unit (ICU) of more than 7 days. Besides patient characteristics, data on nutrition therapy were collected daily for up to 21 days. Morbidity as measured by the mean Sequential Organ Failure Assessment (SOFA) score, incidence of secondary infections, renal replacement therapy, ventilator-free days and severe hypoglycemia, length of ICU stay, and mortality at 90 days were compared between the three nutritional strategies. RESULTS: In all, 353 patients were included in the analysis with the majority (68.5 %) receiving EN+PN, 24.4 % receiving EN, and only 7.1 % receiving PN. Median caloric intake was 918 kcal/day (EN), 1,210 kcal/day (PN), and 1,343 kcal/day (EN+PN; p < 0.001). In the latter group, calories were predominantly administered via the parenteral route within the first week. The rate of death at 90 days was lower with EN than with EN+PN (26.7 % vs. 41.3 %, p = 0.048), as was the rate of secondary infections, renal replacement therapy, and duration of mechanical ventilation. In the adjusted Cox regression analysis, the effect on mortality [hazard ratio (HR)= 1.86, 95 % confidence interval (CI): 1.16-2.98, p = 0.010] and the rate of secondary infections (HR= 1.89, 95 % CI: 1.27-2.81, p = 0.002) remained different between EN and EN+PN. CONCLUSION: In patients with severe sepsis or septic shock and prolonged ICU stay, EN alone was associated with improved clinical outcome compared to EN+PN. This hypothesis-generating result has to be confirmed by a randomized-controlled trial in this specific patient population.


Assuntos
Cuidados Críticos , Nutrição Enteral , Derivados de Hidroxietil Amido/uso terapêutico , Insulina/uso terapêutico , Unidades de Terapia Intensiva , Nutrição Parenteral Total , Substitutos do Plasma , Sepse/terapia , Choque Séptico/terapia , APACHE , Abdome/cirurgia , Idoso , Terapia Combinada , Ingestão de Energia , Feminino , Gastroenteropatias/cirurgia , Alemanha , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/terapia , Modelos de Riscos Proporcionais , Estudos Prospectivos , Terapia de Substituição Renal , Respiração Artificial , Sepse/mortalidade , Choque Séptico/mortalidade , Taxa de Sobrevida
2.
Neurology ; 75(24): 2229-35, 2010 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-21172846

RESUMO

OBJECTIVE: Despite novel multimodal therapeutic approaches, the vast majority of glial tumors are not curable. Patients may search for complementary therapies in order to contribute to the fight against their disease or to relieve symptoms induced by their brain tumor. The extent of the use of complementary or alternative therapies, the patients' rationale behind it, and the cost of complementary therapy for gliomas are not known. We used a questionnaire and the database of the German Glioma Network to evaluate these questions. METHODS: A total of 621 questionnaires were available for evaluation from patients with glial tumors of WHO grades II to grade IV. The patients were recruited from 6 neuro-oncologic centers in Germany. Complementary therapy was defined as methods or compounds not used in routine clinical practice and not scientifically evaluated. RESULTS: Forty percent of the responding patients reported the use of complementary therapies. Significant differences between the group of complementary therapy users and nonusers were seen with respect to age (younger > older), gender (female > male), and education (high education level > low education level). The motivation for complementary therapy use was not driven by unsatisfactory clinical care by the neuro-oncologists, but by the wish to add something beneficial to the standard of care. CONCLUSIONS: In clinical practice, patients' use of complementary therapies may be largely overseen and underestimated. The major motivation is not distrust in conventional therapies. Neuro-oncologists should be aware of this phenomenon and encourage an open but critical dialogue with their patients.


Assuntos
Neoplasias Encefálicas/terapia , Encéfalo/patologia , Terapias Complementares/estatística & dados numéricos , Glioma/terapia , Fatores Etários , Idoso , Neoplasias Encefálicas/patologia , Terapias Complementares/métodos , Feminino , Alemanha/epidemiologia , Glioma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Observação , Índice de Gravidade de Doença , Fatores Sexuais , Inquéritos e Questionários , Resultado do Tratamento
3.
Int J Obes (Lond) ; 31(6): 1004-13, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17130847

RESUMO

OBJECTIVE: Obesity is associated with reduced insulin sensitivity and extensive reorganization of adipose tissue. As polyunsaturated fatty acids (PUFA) appear to inhibit diabetes development, we investigated PUFA effects on markers of matrix remodeling in white adipose tissue. METHODS AND PROCEDURE: Male obese diabetic (db/db) mice were treated with either a low-fat standard diet (LF), or high-fat diets rich in saturated and monounsaturated fatty acids (HF/S), n-6 PUFA (HF/6) or the latter including marine n-3 PUFA (HF/3). White adipose tissue was analyzed for gene expression, fatty acid composition and by immunofluorescence. RESULTS: HF/S treatment increased adipose tissue expression of a number of genes involved in matrix degradation including matrix metalloproteinase (MMP)-12, -14 and cathepsin K, L and S compared with LF. MMP-12 gene was expressed in macrophages and adipocytes, and MMP-12 protein colocalized with both cell types. In addition, mean adipocyte area increased by 1.6-fold in HF/S-treated mice. Genes essential for collagen production, such as procollagen I, III, VI, tenascin C and biglycan were upregulated in HF/S-treated animals as well. N-3 PUFA supplementation resulted in enrichment of these fatty acids in adipose tissue. Moreover, n-3 PUFA inhibited the HF/S-induced upregulation of genes involved in matrix degradation and production I restored mean adipocyte area and prevented MMP-12 expression in macrophages and adipocytes. CONCLUSION: N-3 PUFA prevent high-fat diet-induced matrix remodeling and adipocyte enlargement in adipose tissue of obese diabetic mice. Such changes could contribute to diabetes prevention by n-3 PUFA in obese patients.


Assuntos
Tecido Adiposo Branco/fisiopatologia , Diabetes Mellitus Experimental/fisiopatologia , Gorduras na Dieta/administração & dosagem , Obesidade/fisiopatologia , Adipócitos/fisiologia , Tecido Adiposo Branco/metabolismo , Animais , Biomarcadores/análise , Catepsinas/genética , Tamanho Celular , Colagenases/genética , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/fisiopatologia , Ácidos Graxos/administração & dosagem , Ácidos Graxos/análise , Ácidos Graxos Ômega-3/administração & dosagem , Regulação da Expressão Gênica/fisiologia , Gônadas/metabolismo , Gônadas/fisiopatologia , Fígado/metabolismo , Masculino , Metaloproteinase 12 da Matriz/análise , Camundongos , Camundongos Endogâmicos C3H , Obesidade/complicações , Obesidade/genética , Inibidores Teciduais de Metaloproteinases/genética , Triglicerídeos/análise
4.
Diabetologia ; 49(9): 2109-19, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16783472

RESUMO

AIMS/HYPOTHESIS: Inflammatory alterations in white adipose tissue appear to underlie complications of obesity including diabetes mellitus. Polyunsaturated fatty acids (PUFA), particularly those of the n-3 series, modulate immune responses and may ameliorate insulin sensitivity. In this study, we investigated how PUFA affect white adipose tissue inflammation and gene expression in obese diabetic animals. MATERIALS AND METHODS: We treated db/db mice as well as lean non-diabetic mice (db/+) with either low-fat standard diet (LF) or high-fat diets rich in (1) saturated/monounsaturated fatty acids (HF/S), (2) n-6 PUFA (HF/6) and (3) the latter including purified marine n-3 PUFA (HF/3). RESULTS: Many genes involved in inflammatory alterations were upregulated in db/db mice on HF/S compared with LF in parallel with phosphorylation of c-Jun N-terminal kinase (JNK). In parallel, adipose tissue infiltration with macrophages was markedly enhanced by HF/S. When compared with HF/S, HF/6 showed only marginal effects on adipose tissue inflammation. However, inclusion of n-3 PUFA in the diet (HF/3) completely prevented macrophage infiltration induced by high-fat diet and changes in inflammatory gene expression, also tending to reduce JNK phosphorylation (p<0.1) in diabetic mice despite unreduced body weight. Moreover, high-fat diets (HF/S, HF/6) downregulated expression and reduced serum concentrations of adiponectin, but this was not the case with n-3 PUFA. CONCLUSIONS/INTERPRETATION: n-3 PUFA prevent adipose tissue inflammation induced by high-fat diet in obese diabetic mice, thereby dissecting obesity from adipose tissue inflammation. These data suggest that beneficial effects of n-3 PUFA on diabetes development could be mediated by their effect on adipose tissue inflammation.


Assuntos
Tecido Adiposo Branco/patologia , Ácidos Graxos Ômega-3/administração & dosagem , Inflamação/prevenção & controle , Obesidade/prevenção & controle , Adiponectina/metabolismo , Tecido Adiposo Branco/imunologia , Tecido Adiposo Branco/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus/imunologia , Diabetes Mellitus/metabolismo , Diabetes Mellitus/prevenção & controle , Gorduras na Dieta/administração & dosagem , Imunofluorescência , Perfilação da Expressão Gênica/métodos , Immunoblotting , Inflamação/etiologia , Inflamação/genética , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Obesos , Obesidade/etiologia , Obesidade/genética , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
5.
Gesundheitswesen ; 65(7): 438-42, 2003 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-12891475

RESUMO

Since September 1998 exists a project of cooperation and consultation between the AOK Hesse and the Medical Advisory and Expertising Service Hesse with the aim to identify occupational diseases and to survey decisions of the Employer's Liability Insurance Association. The procedure is based on a computer-added recognition-system, a profound preparation of the single cases by the employees of the health-insurance and a very intensively carried out deliberation by Medical Doctors of occupational medicine. In a period of four and a half year 8391 cases have been reviewed of which 4859 have already been determined. An approval as occupational disease by the Employer's Liability Insurance Association has been determined in 1954 cases, in 2905 cases the acknowledgement has not been determined. Regarding the determined cases a recourse of 10,078,922.27 EUR has been realized. In regard to the invested small resources of personnel the procedure has proved itself as highly effective to discover and to assert recourses. Beside the economical aspects for the public health-insurance, other results of the project were the assurance of the entitlement to benefits of people coming down with occupational diseases or their relatives. New insights about the actual development of occupational diseases in Germany als well as their prevention can be proceeded.


Assuntos
Acidentes de Trabalho , Planos de Assistência de Saúde para Empregados , Seguro Saúde , Doenças Profissionais , Acidentes de Trabalho/legislação & jurisprudência , Aconselhamento , Avaliação da Deficiência , Prova Pericial/legislação & jurisprudência , Alemanha , Planos de Assistência de Saúde para Empregados/economia , Planos de Assistência de Saúde para Empregados/legislação & jurisprudência , Humanos , Seguro de Acidentes/legislação & jurisprudência , Seguro Saúde/economia , Seguro Saúde/legislação & jurisprudência , Seguro de Responsabilidade Civil , Programas Nacionais de Saúde/economia , Doenças Profissionais/induzido quimicamente , Doenças Profissionais/diagnóstico , Doenças Profissionais/economia , Doenças Profissionais/etiologia
6.
Ultraschall Med ; 22(2): 81-6, 2001 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-11398505

RESUMO

AIM: Standard diagnostic tools for vesico-intestinal fistulas are cystoscopy, cystography, colonoscopy, and contrast enema. The aim of our study was to evaluate the efficacy of transrectal 3D-ultrasound with contrast media in these patients. METHOD: From 5/98 to 12/99 we examined 10 patients with symptoms of a vesico-intestinal fistula (pneumaturia, faecaluria). After placement of a transurethral catheter a transabdominal ultrasound examination (Kretz Combison 530) was performed with the bladder half full to evaluate the bladder wall. Then the bladder was filled with diluted ultrasound contrast media (Levovist 40 mg/ml) to visualize the flow from the bladder towards the fistula. To verify a flow through the bladder wall a colour Doppler sonography of the region of interest was added. To evaluate form and extent of the fistula a transrectal ultrasound with 3D-image assessment was performed. RESULTS: Using this technique it was possible to demonstrate a vesico-intestinal fistula in 9 of 10 patients. In all cases these findings were confirmed by the standard diagnostic procedures. The fistulas were caused by: bladder carcinoma (n = 1), carcinoma of the colon (n = 2), Crohn's disease (n = 3) and diverticulitis of the sigma (n = 3). One patient presented with a neovesico-intestinal fistula in an irradiated local recurrence of bladder carcinoma. In one patient with Crohn's disease whose only symptom was pneumaturia all diagnostic tools failed to provide the diagnosis. CONCLUSION: For the first time vesico-intestinal fistulas could be demonstrated by ultrasound with 3D-image assessment using contrast media. This technique might be an effective addition to the standard diagnostics of vesico-intestinal fistulas reducing the exposure to radiation.


Assuntos
Endossonografia , Aumento da Imagem , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Fístula Intestinal/diagnóstico por imagem , Fístula da Bexiga Urinária/diagnóstico por imagem , Meios de Contraste , Humanos , Fístula Intestinal/etiologia , Polissacarídeos , Ultrassonografia Doppler em Cores , Fístula da Bexiga Urinária/etiologia
7.
Eur J Biochem ; 268(6): 1861-8, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11248707

RESUMO

Mammalian dihydroorotate dehydrogenase, the fourth enzyme of pyrimidine de novo synthesis is an integral protein of the inner mitochondrial membrane that faces the intermembrane space and is functionally connected to the respiratory chain via ubiquinone. Here, we describe the first cloning and analyzing of the complete cDNA of mouse dihydroorotate dehydrogenase. Based on our recent functional expression of the full-length rat and human dihydroorotate dehydrogenase, here we expressed N-terminal-truncated C-terminal-histidine-tagged constructs of the mouse, rat and human enzymes in Escherichia coli. These proteins were devoid of the N-terminal bipartite sequence consisting of the mitochondrial targeting sequence and adjacent hydrophobic domain necessary for import and proper location and fixation of the enzyme in the inner mitochondrial membrane. By employing metal-chelate affinity chromatography under native conditions, the enzymes were purified without detergents to a specific activity of more than 100 micromol x min(-1) x mg(-1) at pH optimum of 8.0--8.1. Flavin analyses by UV-visible spectrometry of the native enzymes gave fairly stoichiometric ratios of 0.6--1.2 mol flavin per mol protein. The kinetic constants of the truncated rat enzyme (K(m) = 11 microM dihydroorotate; K(m) = 7 microM ubiquinone) and human enzyme (K(m) = 10 microM dihydroorotate; K(m) = 14 microM ubiquinone) were very close to those recently reported for the full-size enzymes. The constants for the mouse enzyme, K(m) = 26 microM dihydroorotate and K(m) = 62 microM ubiquinone, were slightly elevated in comparison to those of the other species. The three truncated enzymes were tested for their efficacy with five inhibitors of topical clinical relevance against autoimmune disorders and tumors. Whereas the presence of the N-terminus of dihydroorotate dehydrogenase was essentially irrelevant for the efficacy of the malononitrilamides A77-1726, MNA715 and MNA279 with the rat and human enzyme, the N-termini were found to be important for the efficacy of the dianisidine derivative redoxal. Moreover, the complete N-terminal part of the human enzyme seemed to be of crucial importance for the 'slow-binding' features of the cinchoninic acid derivative brequinar, which was suggested to be one of the reasons for the narrow therapeutic window reported from clinical trials on its anti-proliferative and immunosuppressive action.


Assuntos
Inibidores Enzimáticos/farmacologia , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Oxirredutases/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar , Di-Hidro-Orotato Desidrogenase , Eletroforese em Gel de Poliacrilamida , Humanos , Cinética , Camundongos , Dados de Sequência Molecular , Mutação , Oxirredutases/antagonistas & inibidores , Oxirredutases/genética , Ratos , Proteínas Recombinantes/antagonistas & inibidores , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos
8.
Protein Expr Purif ; 13(3): 414-22, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9693067

RESUMO

Mitochondrially bound dihydroorotate-ubiquinone oxidoreductase (dihydroorotate dehydrogenase, EC 1.3.99.11) catalyzes the fourth sequential step in the de novo synthesis of uridine monophosphate. Based on the recent functional expression of the complete rat dihydroorotate dehydrogenase by means of the baculovirus expression vector system in Trichoplusia ni cells, a procedure is described that allows the purification of baculovirus expressed enzyme protein fused to a carboxy-terminal tag of eight histidines. Extracts from mitochondria of Spodoptera frugiperda cells infected with the recombinant virus using Triton X-100 were loaded onto Ni2+-nitrilotriacetic acid agarose and histidine-tagged rat protein was selectively eluted with imidazole-containing buffer. In view of our previously published work, the quality of the electrophoretic homogenous rat enzyme was markedly improved; specific activity was 130-150 micromol dihydroorotate/min per milligram; and the stoichiometry of flavin content was 0.8-1.1 mol/mol protein. Efforts to generate mammalian dihydroorotate dehydrogenases with low production costs from bacteria resulted in successful overexpression of the carboxy-terminal-modified rat and human dihydroorotate dehydrogenase in XL-1 Blue cells. By employing the metal chelate affinity chromatography under native conditions, the histidine-tagged human enzyme was purified with a specific activity of 150 micromol/min/mg and the rat enzyme with 83 micromol/min/mg, respectively, at pH 8.0-8.1 optimum. Kinetic constants of the recombinant histidine-tagged rat enzyme from bacteria (dihydroorotate, Km = 14.6 micromol electron acceptor decylubiquinone, Km = 9.5 micromol) were close to those reported for the enzyme from insect cells, with or without the affinity tag. HPLC analyses identified flavin mononucleotide as cofactor of the rat enzyme; UV-vis and fluorometric analyses verified a flavin/protein ratio of 0.8-1.1 mol/mol. By spectral analyses of the functional flavin with the native human enzyme, the interaction of the pharmacological inhibitors Leflunomide and Brequinar with their target could be clarified as interference with the transfer of electrons from the flavin to the quinone. The combination of the bacterial expression system and metal chelate affinity chomatography offers an improved means to purify large quantities of mammalian membrane-bound dihydroorotate dehydrogenases which, by several criteria, possesses the same functional activities as non-histidine-tagged recombinant enzymes.


Assuntos
Histidina/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Oxirredutases/genética , Animais , Baculoviridae/genética , DNA Complementar , Di-Hidro-Orotato Desidrogenase , Eletroforese em Gel de Poliacrilamida , Humanos , Concentração de Íons de Hidrogênio , Cinética , Dados de Sequência Molecular , Oxirredutases/isolamento & purificação , Oxirredutases/metabolismo , Ratos , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Spodoptera
9.
Protein Expr Purif ; 10(1): 89-99, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9179295

RESUMO

Mammalian dihydroorotate dehydrogenase (EC 1.3.99.11), the fourth enzyme of pyrimidine de novo synthesis is located in the mitochondrial inner membrane with functional connection to the respiratory chain. From the cDNA of rat liver dihydroorotate dehydrogenase cloned in our laboratory the first complete sequence of a mammalian enzyme was deduced. Two hydrophobic stretches centered around residues 20 and 357, respectively, and a short N-terminal mitochondrial targeting sequence of 10 amino acids was proposed. A recombinant baculovirus containing the rat liver cDNA for dihydroorotate dehydrogenase was constructed and used for virus infection and protein expression in Trichoplusia ni cells. The targeting of the recombinant protein to mitochondria of the insect cells was monitored by activity determination of dihydroorotate dehydrogenase in subcellular compartments in comparison to succinate dehydrogenase activity (EC 1.3.5.1), which is a specific marker enzyme of the inner mitochondrial membrane. The results of subcellular distribution were verified by Western blotting with anti-dihydroorotate dehydrogenase immunoglobulins. The activity of the recombinant enzyme in the mitochondria of infected insect cells was found to be about 570-fold above the level of dihydroorotate dehydrogenase in rat liver mitochondria. By cation exchange chromatography of the Triton X-114 solubilisate of mitochondria, dihydroorotate dehydrogenase was purified to give a specific activity of 15 U/mg at pH 8.0. This was a marked progress over the six-step purification procedure of the enzyme from rat liver which resulted in a specific activity of 0.7 U/mg at pH 8.0. The characteristic flavin absorption spectrum obtained with the recombinant enzyme gave strong evidence that the rodent enzyme is a flavoprotein. By enzyme kinetic studies K(m) values for dihydroorotate and ubiquinone were 6.4 and 9.9 microM with the recombinant enzyme, and were 5.0 and 19.7 microM, respectively, with the rat liver enzyme. After expression of only truncated forms of human dihydroorotate dehydrogenase, the present successful generation of the complete rodent enzyme using insect cells and the efficient procedure will promote structure and function studies of the eukaryotic dihydroorotate dehydrogenases in comparison to the microbial enzyme.


Assuntos
Mitocôndrias/química , Mariposas/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Oxirredutases/genética , Ratos/genética , Sequência de Aminoácidos , Animais , Western Blotting , Linhagem Celular , Cromatografia por Troca Iônica , DNA Complementar/genética , Di-Hidro-Orotato Desidrogenase , Vetores Genéticos/genética , Humanos , Cinética , Fígado/química , Dados de Sequência Molecular , Mariposas/citologia , Nucleopoliedrovírus/genética , Ácido Orótico/análogos & derivados , Ácido Orótico/metabolismo , Oxirredutases/biossíntese , Oxirredutases/isolamento & purificação , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/isolamento & purificação , Spodoptera/citologia , Spodoptera/metabolismo , Especificidade por Substrato , Ubiquinona/metabolismo
11.
Exp Cell Res ; 157(1): 195-206, 1985 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3972010

RESUMO

The effect of 1 microM antimycin on the proliferative properties, metabolism and basic cell composition of Ehrlich ascites tumour cells cultured in the second in vitro passage was studied. Continuous drug exposure of asynchronous cells caused rapid cessation of cell growth, characterized by the cell number and DNA, RNA and protein content of cultures. Cells cease to consume oxygen and enhance their glycolytic activity. Uptake of labelled thymidine into acid-insoluble material was far below that of the controls, whereas incorporation of labelled uridine exceeded that of controls, as was also observed with other inhibitors of the respiratory chain (sodium cyanide, 2-thenoyltrifluoroacetone, or anaerobiosis). The influence of antimycin on cells at different stages of the cell cycle was tested using cells enriched in either G1, S or G2 phase by centrifugal elutriation. DNA histograms (flow cytometry) and pulse-labelling index curves gave detailed insight into cell-cycle progression of antimycin-treated cells: G1 and early S cells remained stationary; G2 cells still passed from G2 into mitosis to remain subsequently in a non-growing state in G1; S cells were either slowed or halted. Supplementation of antimycin-containing cultures with exogenous pyrimidine nucleosides stimulated reprogression of G1 cells without changing their ATP content. The results of the current experiments are interpreted as supporting the concept that growth cessation of G1 cells under respiratory insufficiency is not predominantly caused by impairment of respiratory phosphorylation but may be the consequence of a lack of precursors for DNA and RNA synthesis.


Assuntos
Antimicina A/análogos & derivados , Ciclo Celular/efeitos dos fármacos , Oxigênio/fisiologia , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Antimicina A/farmacologia , Carcinoma de Ehrlich/metabolismo , Carcinoma de Ehrlich/patologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , DNA de Neoplasias/metabolismo , Feminino , Citometria de Fluxo , Interfase/efeitos dos fármacos , Camundongos , Proteínas de Neoplasias/metabolismo , Nucleosídeos de Pirimidina/metabolismo , RNA Neoplásico/metabolismo
12.
Z Naturforsch C Biosci ; 35(1-2): 124-8, 1980.
Artigo em Inglês | MEDLINE | ID: mdl-7405357

RESUMO

Total lipids of Ehrlich ascites tumor cells grown in nutrient medium supplemented with 1% bovine serum albumin instead of 15% native horse serum and rate of incorporation of [3H] acetate into total lipids are reduced, while the cholesterol content of the cells is higher than of controls grown in normal medium. The lower lipid content of cells cultured in albumin supplemented medium is explained by a lack of exogenous lipids, which are normally taken up from the serum containing nutrient medium. A several fold increase of incorporation of labelled choline and ethanolamine into the phospholipids of the cells grown in the modified medium is observed. We suggest, that the observed stimulation of the incorporation of phospholipid precursors reflects changes in the dynamic state of the membranes produced by serum depletion.


Assuntos
Carcinoma de Ehrlich/metabolismo , Metabolismo dos Lipídeos , Soroalbumina Bovina , Animais , Transporte Biológico , Divisão Celular , Colesterol/metabolismo , Colina/metabolismo , Meios de Cultura , Camundongos , Fosfolipídeos/metabolismo
13.
J Cancer Res Clin Oncol ; 95(2): 115-22, 1979 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-521449

RESUMO

Anaerobic culture conditions (95% argon/5% CO2) caused a slightly greater increase in total lipids of Ehrlich ascites tumor cells than a gas phase of 20% O2, 75% N2, 5% CO2. Whereas the rate of [U-14C]acetate incorporation into total lipids and lipid-subclasses rose markedly in the absence of oxygen, a drastic decrease of [U-14C]pyruvate and [1-14C]octanoate incorporation as well as a 30% reduction of 3H incorporation into lipids from tritiated water were observed under these conditions. Since profound changes in the metabolic state of cells cause alterations in the specific activity of the acetyl-CoA pool but do not alter the specific activity of intracellular water, this precursor is considered to be an adequate monitor for lipogenesis under aerobic and anaerobic culture conditions. Therefore, it is concluded that Ehrlich ascites tumor cells are not able to reoxidize NADH/NADPH in the absence of oxygen by a stimulation of biosynthesis of fatty acids as is discussed to be the case in normal cells. The slight increase in total lipids of anaerobically cultured cells seems to be the result of an imbalance between normal uptake and impaired utilization of lipids from serum-supplemented culture medium.


Assuntos
Anaerobiose , Carcinoma de Ehrlich/metabolismo , Lipídeos/biossíntese , Metabolismo , Animais , Células Cultivadas , Ácidos Graxos/biossíntese , Feminino , Hipóxia , Camundongos , Oxigênio
14.
Z Naturforsch C Biosci ; 34(9-10): 805-10, 1979.
Artigo em Inglês | MEDLINE | ID: mdl-160704

RESUMO

Cell proliferation, viability, DNA-, RNA-, protein synthesis, amino acid transport, repiration and lactate/glucose quotient of Ehrlich ascites tumor cells grown in suspension culture in serum free medium supplemented with albumin charges of different origin were studied. Optimal cell growth was obtained in nutrient medium supplemented with 1% bovine serum albumin (Cohn-fraction V, Serva). Cell proliferation under these culture conditions was delayed to 50% as compared to controls in normal medium; the rate of synthesis of macromolecules was reduced; energy metabolism was not significantly imparied. The trend of the cells in albumin medium to attach to glass was independent from the pH of the cultures between 7.2 and 8.0; it was enhanced by fatty acid deprivation of the albumin.


Assuntos
Carcinoma de Ehrlich/fisiopatologia , Albumina Sérica , Aminoácidos/metabolismo , Ácidos Aminoisobutíricos/metabolismo , Animais , Transporte Biológico , Carcinoma de Ehrlich/metabolismo , Divisão Celular , Sobrevivência Celular , Meios de Cultura , DNA de Neoplasias/biossíntese , Feminino , Glucose/metabolismo , Cavalos , Humanos , Lactatos/metabolismo , Camundongos , Proteínas de Neoplasias/biossíntese , RNA Neoplásico/biossíntese
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