Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
1.
Nature ; 629(8012): 688-696, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38658752

RESUMO

Although cancer initiation and progression are generally associated with the accumulation of somatic mutations1,2, substantial epigenomic alterations underlie many aspects of tumorigenesis and cancer susceptibility3-6, suggesting that genetic mechanisms might not be the only drivers of malignant transformation7. However, whether purely non-genetic mechanisms are sufficient to initiate tumorigenesis irrespective of mutations has been unknown. Here, we show that a transient perturbation of transcriptional silencing mediated by Polycomb group proteins is sufficient to induce an irreversible switch to a cancer cell fate in Drosophila. This is linked to the irreversible derepression of genes that can drive tumorigenesis, including members of the JAK-STAT signalling pathway and zfh1, the fly homologue of the ZEB1 oncogene, whose aberrant activation is required for Polycomb perturbation-induced tumorigenesis. These data show that a reversible depletion of Polycomb proteins can induce cancer in the absence of driver mutations, suggesting that tumours can emerge through epigenetic dysregulation leading to inheritance of altered cell fates.


Assuntos
Transformação Celular Neoplásica , Proteínas de Drosophila , Drosophila melanogaster , Epigênese Genética , Neoplasias , Proteínas do Grupo Polycomb , Animais , Feminino , Masculino , Transformação Celular Neoplásica/genética , Drosophila melanogaster/citologia , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Janus Quinases/genética , Janus Quinases/metabolismo , Neoplasias/genética , Neoplasias/patologia , Proteínas do Grupo Polycomb/deficiência , Proteínas do Grupo Polycomb/genética , Proteínas do Grupo Polycomb/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transdução de Sinais/genética , Fatores de Transcrição STAT/genética , Fatores de Transcrição STAT/metabolismo
3.
Scand J Rheumatol ; 44(4): 309-14, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25656459

RESUMO

OBJECTIVES: To describe the efficacy and safety of different biological agents in a large cohort of 20 patients with adult-onset Still's disease (AOSD). METHOD: We retrospectively evaluated 20 patients with severe or refractory AOSD treated with at least one biological agent (anakinra, etanercept, tocilizumab, and adalimumab), followed up for at least 12 months at our Institution. We collected and analysed data on the disease course, treatment outcome, and adverse effects, and compared our data with other published series. RESULTS: The median duration of follow-up was 5 years. In 12 patients a single biological drug induced a clinical response. In eight patients the biological agent that was first administered proved ineffective, and a switch to a different biologic was necessary. In three patients a third biologic was necessary to achieve disease control. The biologics eventually determined a clinical response in all patients. Patients with systemic disease showed better responses than patients with chronic articular disease (p < 0.05). Biological agents allowed either the withdrawal or the tapering of corticosteroid therapy (p < 0.0001) and of disease-modifying anti-rheumatic agents (DMARDs; p < 0.05). Three patients experienced herpes zoster reactivation. CONCLUSIONS: This is the longest follow-up of a cohort of AOSD patients treated with biological agents. Our data show that biologics are safe and generally effective in the long-term management of AOSD, particularly in cases with systemic disease, and suggest that a clinical response can be obtained in almost all AOSD patients, although a switch to drugs with a different mechanism of action may be necessary.


Assuntos
Fatores Biológicos/efeitos adversos , Fatores Biológicos/uso terapêutico , Doença de Still de Início Tardio/tratamento farmacológico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adalimumab , Adolescente , Adulto , Idoso , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/uso terapêutico , Estudos de Coortes , Etanercepte , Feminino , Seguimentos , Humanos , Imunoglobulina G/efeitos adversos , Imunoglobulina G/uso terapêutico , Proteína Antagonista do Receptor de Interleucina 1/efeitos adversos , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Receptores do Fator de Necrose Tumoral/uso terapêutico , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
4.
J Gerontol A Biol Sci Med Sci ; 55(9): M516-21, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10995049

RESUMO

BACKGROUND: Bone loss in elderly men is associated with changes in body composition and reduced secretion of endogenous anabolizing hormones. The independent influences of body composition and endocrine factors on male bone metabolism, however, are unclear. METHODS: Bone mass density (BMD) (bone mass content [BMC, g]/projected bone area [BA, cm2]) at different skeletal sites, skeletal muscle, and body fat mass were measured by dual-energy X-ray absorptiometry in 129 men aged 20 to 95 years. Free testosterone, 17-beta-estradiol, dehydroepiandrosterone-sulfate, and insulin-like growth factor 1 (IGF-1) serum concentrations were measured. Because BMD may fail to control for differences in skeletal size, the associations of bone mass with body composition and hormones were studied by comparing BMD regression models incorporating age and knee height only with BMC regression models also incorporating BA. RESULTS: Skeletal muscle had close associations (p at least < .01) with BMD and BMC at almost all skeletal sites, but the strength of these associations was generally reduced in BMC with respect to BMD models. Weak associations (p < .05) were found in both models for fatness with femoral bone and for 17-beta-estradiol with total body and femoral bone. The association of 17-beta-estradiol with spinal bone was significant (p < .05) in the BMD but not in the BMC model. No association of BMC or BMD with androgens and IGF-1 reached significancy. CONCLUSIONS: Skeletal muscle may be more important than fatness and anabolizing hormones in preserving bone mass in elderly men. In contrast to traditional belief, estrogens may be more important than androgens and IGF-1 in male bone metabolism.


Assuntos
Envelhecimento/fisiologia , Androgênios/sangue , Composição Corporal/fisiologia , Densidade Óssea/fisiologia , Estrogênios/sangue , Fator de Crescimento Insulin-Like I/análise , Absorciometria de Fóton , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/sangue , Anabolizantes/sangue , Índice de Massa Corporal , Sulfato de Desidroepiandrosterona/sangue , Estradiol/sangue , Fêmur/anatomia & histologia , Humanos , Articulação do Joelho/anatomia & histologia , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/anatomia & histologia , Análise de Regressão , Coluna Vertebral/anatomia & histologia , Testosterona/sangue
7.
AJR Am J Roentgenol ; 165(4): 863-6, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7676982

RESUMO

OBJECTIVE: Our study assessed the feasibility of detecting and measuring by sonography the diameter of the thoracic duct in healthy subjects and in patients with cirrhosis and portal hypertension. We also evaluated the relationship of thoracic duct size with age and with clinical, endoscopic, and sonographic signs of portal hypertension. SUBJECTS AND METHODS: The left supraclavicular area of 24 patients with cirrhosis and 23 healthy subjects was examined with high-frequency probes using transverse and oblique scans to visualize the distal end of the thoracic duct. All patients with cirrhosis, diagnosed by liver biopsy or clinical and biochemical data, had endoscopic or sonographic signs of portal hypertension. The severity of the liver disease was determined by Child-Pugh's criteria; the diameter of portal vessels and the size of esophageal varices were also considered. RESULTS: The thoracic duct was visualized in 19 of 24 patients with cirrhosis and in 18 of 23 control subjects (percent of visualization was 79% and 78%, respectively). The diameter of the duct was larger in patients with cirrhosis than in healthy subjects (3.1 +/- 1.2 mm versus 1.9 +/- 0.5 mm; p < .0001), but no relationship was found among clinical, endoscopic, and sonographic signs of portal hypertension. A direct relationship between age and the size of the thoracic duct was found only among healthy subjects. CONCLUSION: This is the first report of the sonographic visualization of the distal end of the thoracic duct. Its diameter is small in healthy young subjects, whereas in patients with cirrhosis its increased diameter seems to be associated only with the presence of portal hypertension and not with its severity.


Assuntos
Hipertensão Portal/diagnóstico por imagem , Ducto Torácico/diagnóstico por imagem , Humanos , Hipertensão Portal/etiologia , Cirrose Hepática/complicações , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Ultrassonografia
8.
Neurology ; 45(9): 1678-83, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7675226

RESUMO

The methylation and transsulfuration pathways are intimately linked and have been implicated in the progression of neurologic damage and immune cell depletion caused by human immunodeficiency virus (HIV) infection. We studied the following metabolites related to these pathways: S-adenosylmethionine (SAMe), homocysteine, cysteine, cysteinyl-glycine, and glutathione (GSH) in blood and CSF of 16 HIV-infected patients with neurologic complications and 20 HIV-negative control patients undergoing lumbar punctures for other medical reasons. We confirmed recent studies of decreased CSF SAMe concentrations in HIV infection and demonstrated that diastereomers of SAMe are present in CSF but not in plasma or erythrocytes from both HIV-infected and HIV-negative patients. In HIV-infected patients, CSF GSH and cysteinyl-glycine, but not homocysteine or cysteine, were significantly reduced. This is the first report of decreased CSF GSH induced by HIV infection. GSH has a regulatory effect on the synthesis of SAMe in hepatic tissue, and the same mechanism may also apply in the CNS. Administration of SAMe-butanedisulphonate, 800 mg/d intravenously for 14 days, was associated with significant increases in CSF SAMe and GSH. These findings have potentially important therapeutic implications for the use of SAMe in protecting against SAMe and GSH deficiency in the CNS of HIV-infected patients.


Assuntos
Glutationa/líquido cefalorraquidiano , Infecções por HIV/líquido cefalorraquidiano , S-Adenosilmetionina/líquido cefalorraquidiano , Adulto , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Infusões Parenterais , Masculino , Pessoa de Meia-Idade , S-Adenosilmetionina/administração & dosagem
9.
J Hepatol ; 22(6): 633-41, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7560857

RESUMO

The epidemiological and clinical characteristics of peptic ulcer were studied in 324 of 368 consecutive patients with cirrhosis of the liver during a mean period of 1.2 (+/- 0.61) years. Peptic ulcer prevalence rates in patients with cirrhosis were as follows: point prevalence 11.7%, period prevalence 15.1%, and life-time prevalence 24.2%. The annual incidence rate observed in 140 patients with cirrhosis undergoing endoscopic follow up was 4.3%. Ulcers were asymptomatic in more than 70% of patients. The peptic ulcer complication rate at entry was 20% in the whole group and 40% in those who had not a previous diagnosis of peptic ulcer when admitted to the study. Peptic ulcer was more frequent among HBsAg+ cirrhotics (p = 0.05). Patients with more severely decompensated cirrhosis also had a higher frequency of asymptomatic ulcers (p = 0.04), gastric ulcers (p = 0.01) and asymptomatic gastric ulcers (p = 0.005). After diagnosis, during endoscopic follow up, gastric ulcer in patients with cirrhosis tended to heal slowly and recurred with higher frequency than in controls without cirrhosis (p = 0.04). Seventy-nine per cent of peptic ulcer recurrences were asymptomatic in patients with cirrhosis. There were no complications during the follow-up period: this could be due to the regular timing of endoscopy, which permitted early detection and treatment of the recurrences, thus preventing further complications.


Assuntos
Cirrose Hepática/complicações , Úlcera Péptica/complicações , Endoscopia do Sistema Digestório , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Úlcera Péptica/epidemiologia , Prevalência , Prognóstico , Estudos Prospectivos , Recidiva
10.
G Ital Cardiol ; 24(11): 1371-8, 1994 Nov.
Artigo em Italiano | MEDLINE | ID: mdl-7828790

RESUMO

BACKGROUND: The evaluation of mitral valve area (MVA) in patients with mitral stenosis represents the main purpose of any diagnostic method, provided that MVA is a key parameter to indicate the need for valve surgery. The aim of this study was to assess whether the presence of aortic regurgitation associated with mitral stenosis affects the MVA measurement by left atrial pressure half time (PHT). METHODS: Eighty-nine patients with mitral valve stenosis (68 females and 21 males, mean age 53.6 +/- 12.1 years), were studied. Fourty-eight patients (36 females and 12 males) had a concomitant aortic regurgitation (AR group), whereas 41 patients (32 females and 9 males) did not reflect any aortic valve involvement (no-AR group). Aortic regurgitation was graded on the basis of color flow analysis. The majority of patients had a slight to moderate regurgitation. MVA determination was carried out using both Hatle formula (220/PHT) and planimetric measurement in parasternal short axis view. RESULTS: Statistical analysis demonstrated a good correlation between the 2 MVA measurement in both groups (IA group: r = 0.9, p < 0.0001, SSE = 0.21 cm2, y = 0.91x + 0.05; no-IA group r = 0.92, p < 0.0001, SSE = 0.22 cm2, y = 0.92x + 0.04). The concomitant aortic valve disease did not affect in any way the MVA measurement by means of the PHT method. CONCLUSIONS: The Doppler derived method appears to be reliable for estimating the mitral valve area in patients with mitral stenosis even in the presence of aortic regurgitation.


Assuntos
Insuficiência da Valva Aórtica/complicações , Ecocardiografia Doppler , Estenose da Valva Mitral/diagnóstico por imagem , Valva Mitral/diagnóstico por imagem , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador
11.
Hepatology ; 20(1 Pt 1): 66-73, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8020906

RESUMO

We followed 87 cirrhotic patients with esophageal varices and without previous hemorrhage for a mean period of 24 mo to prospectively evaluate the occurrence of variceal bleeding within (early) or after (late) 6 mo from entry and the contribution of portal Doppler ultrasound parameters to the prediction of early and late hemorrhage. Clinical, biochemical, endoscopic and portal Doppler ultrasound parameters were recorded at entry. Variceal bleeding occurred in 22 patients (25.3%). Nine (40.9%) bled within the first 6 mo. Cox regression analysis identified variceal size, cherry-red spots, serum bilirubin and congestion index of the portal vein (the ratio of portal vein [cross-sectional area] and portal blood flow velocity) as the only independent predictors of first variceal hemorrhage. Discriminant analysis was used to find the prognostic index cut off points to identify patients who bled within 6 mo (prognostic group 1) or after 6 mo (prognostic group 2) or remained free of bleeding (prognostic group 3). The cumulative proportion of patients correctly classified was 73% in prognostic group 1, 47% in prognostic group 2 and more than 80% in prognostic group 3. The addition of Doppler ultrasound flowmetry to clinical, biochemical and endoscopic parameter only improved the classification of patients with early bleeding.


Assuntos
Varizes Esofágicas e Gástricas/diagnóstico , Hemorragia Gastrointestinal/diagnóstico , Cirrose Hepática/complicações , Adulto , Idoso , Análise de Variância , Bilirrubina/sangue , Análise Discriminante , Varizes Esofágicas e Gástricas/diagnóstico por imagem , Varizes Esofágicas e Gástricas/etiologia , Esofagoscopia , Feminino , Seguimentos , Hemorragia Gastrointestinal/diagnóstico por imagem , Hemorragia Gastrointestinal/etiologia , Gastroscopia , Humanos , Cirrose Hepática/sangue , Cirrose Hepática/fisiopatologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Veia Porta/diagnóstico por imagem , Veia Porta/fisiopatologia , Prognóstico , Estudos Prospectivos , Análise de Regressão , Reologia , Fatores de Tempo , Ultrassonografia
12.
J Hepatol ; 20(1): 11-8, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8201210

RESUMO

The relationship of the endoscopic aspect of esophageal varices, portal quantitative Doppler ultrasound parameters and clinical and biochemical findings was assessed in 149 patients with cirrhosis stratified according to the presence of esophageal varices (n = 115) and the absence of previous bleeding (n = 96). In this series of patients the presence of esophageal varices and red signs proved to be significantly correlated with the severity of cirrhosis. However, in the group of patients with varices, no correlation was found between variceal size and the degree of liver failure. Portal blood flow velocity was significantly different in the endoscopic subgroups, but not in the clinical and biochemical subgroups. Furthermore, portal blood flow velocity was found to correlate only with the presence and size of esophageal varices. The Congestion Index of the portal vein (derived from the ratio between the cross-sectional area of the portal vein and the mean velocity of portal flow) was significantly different in most clinical, biochemical and endoscopic subgroups and was correlated with liver function, presence and size of varices, and presence and degree of red signs. We conclude that the Congestion Index of the portal vein, the clinical status and the endoscopic aspect of varices are not independent features in patients with cirrhosis. As for liver function and endoscopic findings, portal Doppler ultrasound parameters, in particular the Congestion Index, may contribute to a better clinical assessment in patients with cirrhosis.


Assuntos
Varizes Esofágicas e Gástricas/diagnóstico , Hemorragia Gastrointestinal/diagnóstico , Cirrose Hepática/complicações , Sistema Porta/fisiopatologia , Endoscopia do Sistema Digestório , Feminino , Humanos , Hipertensão Portal/diagnóstico , Cirrose Hepática/diagnóstico , Cirrose Hepática/fisiopatologia , Masculino , Pessoa de Meia-Idade , Reologia , Ultrassom
13.
Am J Nephrol ; 13(4): 244-8, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8267020

RESUMO

Serum levels of soluble interleukin-2 receptors (IL2R) and of beta 2-microglobulin (beta 2M) were studied with the immunoenzymatic technique in 38 patients with primary glomerulonephritis (GN), in 10 patients with essential hypertension (EH) and in 30 healthy subjects. IL2R correlated with beta 2M (p < 0.05). IL2R and beta 2M were higher in patients with GN (p < 0.003, p < 0.001, respectively) and in patients with EH (p < 0.003, p < 0.01, respectively) than in healthy subjects. IL2R and beta 2M correlated with serum creatinine, but not with proteinuria. Our data would suggest the existence of lymphocyte activation in patients with GN. Only speculations can be advanced with regard to the observed increase in these parameters in EH patients.


Assuntos
Glomerulonefrite/sangue , Receptores de Interleucina-2/análise , Microglobulina beta-2/análise , Adulto , Feminino , Humanos , Hipertensão/sangue , Masculino , Solubilidade , Fator de Necrose Tumoral alfa/análise
15.
Ann Ital Med Int ; 7(3): 141-7, 1992.
Artigo em Italiano | MEDLINE | ID: mdl-1457253

RESUMO

We used color-Doppler echocardiography in an investigation of cardiac morphology and function to verify the cardiac anatomic and functional changes in acromegalic patients with or without hypertension and hyperlipemic states. Fifteen patients with growth hormone-secreting pituitary adenoma (mean age: 47.9 years) and 15 healthy control subjects were studied. We measured serum growth hormone (GH), somatomedin-C, cholesterol, triglyceride levels and carried out echocardiographic studies of the following cardiac morpho-functional parameters: left ventricular diameter, volume, mass and wall systolic stress. Serum GH and somatomedin-C levels were significantly higher in acromegalic patients than in controls (p < 0.001 and p < 0.001 respectively). Echocardiography evidenced increased left ventricular mass (60% of the acromegalic patients; p < 0.05) and increased wall systolic stress (53.3%; p < 0.05). Color-Doppler analysis evidenced abnormal diastolic function in 8 acromegalic patients (p < 0.001). We thus conclude that the most characteristic feature of acromegalic heart disease is left ventricular involvement, diastolic dysfunction, increased left ventricular mass or wall systolic stress. The pathogenesis is most probably multifactorial: essential hypertension, associated with slow and progressive evolution of heart disease, appears to be a determining factor.


Assuntos
Acromegalia/diagnóstico por imagem , Cardiomiopatias/diagnóstico por imagem , Ecocardiografia Doppler , Acromegalia/sangue , Acromegalia/fisiopatologia , Adulto , Cardiomiopatias/sangue , Cardiomiopatias/fisiopatologia , Doença Crônica , Ecocardiografia Doppler/estatística & dados numéricos , Feminino , Hormônio do Crescimento/sangue , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Fator de Crescimento Insulin-Like I/análise , Masculino , Pessoa de Meia-Idade
16.
Artif Organs ; 16(2): 131-40, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10078234

RESUMO

Tumor necrosis factor (TNF) was detected, before and after dialysis, in sera from 69 patients and, at various times during dialysis, in 28 patients carefully selected for the absence of intercurrent illness. Blood samples were also sequentially collected for separation of monocytes, and cells were sonicated to detect intracellular TNF. Compared with serum levels obtained from 41 healthy subjects, basal TNF values of the unselected group of 69 patients were significantly higher (p < 0.01), independent of the dialyzer membrane. A significant increase in TNF levels by the end of dialysis was found only with Cuprophan (p < 0.01). In the selected group of 28 patients, no significant changes in TNF values were observed in sequential samples. However, a significant increase of intramonocyte TNF levels was found in Cuprophan patients (p < 0.025). Soluble interleukin-2 receptor (IL-2R) levels, measured in parallel in sera from unselected and selected patients, were found to be very much higher than healthy controls without significant changes during the dialysis procedure. While the diverse profiles of TNF obtained from differently selected patients suggest that mechanisms other than membrane biocompatibility play a role in the appearance of these low cytokine levels, the possible nature of uremic toxin for soluble IL-2R can be envisaged by detection in dialysis patients.


Assuntos
Receptores de Interleucina-2/sangue , Diálise Renal , Fator de Necrose Tumoral alfa/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Membranas Artificiais , Pessoa de Meia-Idade , Monócitos/metabolismo , Neopterina/sangue
17.
Exp Cell Res ; 197(2): 148-52, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1959552

RESUMO

4-Hydroxynonenal (HNE) is the major diffusible toxic product generated by lipid peroxidation of cellular membranes. The level of lipid peroxidation and, consequently, the concentration of its products are inversely related to the rate of cell proliferation and directly related to the level of cell differentiation. In the present paper the effects of HNE on the proliferation and differentiation of the HL-60 human promyelocytic cell line have been investigated. Repeated treatment at 45-min intervals with HNE (1 microM) was performed to maintain the cells in the presence of the aldehyde for 7 1/2 or 9 h. The effect of HNE on cell proliferation and differentiation was compared with dimethyl sulfoxide (DMSO)-treated cells. HNE causes a strong inhibition of cell growth without affecting cell viability. Moreover, HL-60 cells acquire the capability to produce chemiluminescence after soluble (phorbol myristate acetate) or corpuscolate (zymosan) stimulation. The phagocytic ability has also been calculated by counting the number of cells that phagocytize opsonized zymosan. Values were 43 and 55% after 10 or 12 HNE treatments, respectively, and 88% in DMSO-treated cells. Myeloperoxidase activity, 5 days after treatment, decreased by 85% in either HNE- or DMSO-treated cells while acid phosphatase activity increased with respect to untreated cells. Results obtained indicate that HNE at concentrations close to those found in the normal tissues can induce inhibition of proliferation and induction of differentiation in the HL-60 cell line.


Assuntos
Aldeídos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Peroxidação de Lipídeos , Fosfatase Alcalina/metabolismo , Linhagem Celular , Replicação do DNA/efeitos dos fármacos , Dimetil Sulfóxido/farmacologia , Humanos , Cinética , Leucemia Promielocítica Aguda , Medições Luminescentes , Timidina/metabolismo
19.
Biochem Biophys Res Commun ; 178(3): 1260-5, 1991 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-1872846

RESUMO

Whole cell lipids were extracted from the Lewis lung carcinoma in vitro line C108. The fatty acids were derivatized to methylesters in order to identify endogenous oxidized derivatives by gasmass spectroscopy. The presence of 9-hydroxystearic acid and 10-hydroxystearic acid was thus evidenced for the first time in cultured mammalian cells. Moreover a linear correlation was found between the concentration of these products expressed as percentage of total fatty acid methylesters and the cell density in tissue culture flasks. This finding suggests an involvement of hydroxystearic acid in cellular functions related to the cell density in monolayer cultures.


Assuntos
Peroxidação de Lipídeos , Neoplasias Pulmonares/metabolismo , Ácidos Esteáricos/metabolismo , Animais , Linhagem Celular , Cromatografia Gasosa , Cromatografia em Camada Fina , Cromatografia Gasosa-Espectrometria de Massas , Camundongos , Ácidos Esteáricos/isolamento & purificação
20.
Cell Biochem Funct ; 8(3): 147-55, 1990 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2397562

RESUMO

The lipid peroxidation product 4-hydroxy-2, 3-trans-nonenal (HNE) has a spectrum of biological effects on different cell types depending on the concentrations tested. In particular micromolar HNE concentrations stimulate neutrophil migration and polarization whereas higher doses inhibit. In our experimental conditions, fMet-Leu-Phe (fMLP) increased CL production of both unstimulated and zymosan-stimulated neutrophils, whereas cell stimulation with low HNE concentrations as well as zymosan addition to HNE incubated cells did not enhance light emission. In contrast 10(-4) M HNE reduced CL emission by unstimulated cells nearly to background values, completely depressed CL production by zymosan-stimulated cells and reduced phagocytosis. Cysteine was found to be able to counteract the HNE effect by about 70 per cent. The possibility that this aldehyde could exert its inhibitory effect through the alkylation of NADPH-oxidase SH-groups is postulated. Moreover, our present data on differences observed between fMLP and HNE indicate a different chemotactic mechanism induced by these two classes of compounds and lead to the conclusion that the local functional features of the attracted cells may be different.


Assuntos
Aldeídos/farmacologia , Neutrófilos/metabolismo , Humanos , Medições Luminescentes , Luminol , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/efeitos dos fármacos , Proteínas Opsonizantes , Oxirredução , Fagocitose/fisiologia , Zimosan/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA