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2.
Curr Oncol ; 23(1): 42-51, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26966403

RESUMO

Infections are a major cause of morbidity and mortality in patients with chronic lymphocytic leukemia (cll), who typically have increased susceptibility because of hypogammaglobulinemia (hgg) related to their disease and its treatment. Immunoglobulin replacement therapy (igrt) has been shown to reduce the frequency of bacterial infections and associated hospitalizations in patients with hgg or a history of infection, or both. However, use of igrt in cll is contentious. Studies examining such treatment were conducted largely before the use of newer chemoimmunotherapies, which can extend lifespan, but do not correct the hgg inherent to the disease. Thus, the utility of igrt has to be re-evaluated in the current setting. Here, we discuss the evidence for the use of igrt in cll and provide a practical approach to its use in the prevention and management of infections.

3.
Bone Marrow Transplant ; 51(4): 529-35, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26691426

RESUMO

Despite survival improvement with novel agents and use of autologous hematopoietic stem cell transplantation (HSCT), cure of patients with multiple myeloma (MM) remains anecdotal. Initial observations suggested that chronic GvHD was accompanied by an anti-myeloma effect after myeloablative HSCT, but unfortunately this procedure was hampered by high non-relapse mortality (NRM). To maximize the anti-myeloma effect and minimize NRM, we developed a non-myeloablative (NMA) regimen associated with a high incidence of chronic GvHD and tested its efficacy on patient survival and disease eradication. From 2001 to 2010, 92 patients aged ⩽ 65 years with a compatible sibling donor received autologous HSCT followed by an outpatient NMA allogeneic HSCT using a conditioning of fludarabine and cyclophosphamide. Patient median age was 52 years and 97% presented Durie-Salmon stages II-III disease. After a median follow-up of 8.8 years, probability of 10-year progression free and overall survival were 41% and 62%, respectively. Although the cumulative incidence of extensive chronic GvHD was high (at 79%), the majority of long-term survivors were off immunosuppressive drugs by year 5 and NRM was low (at 10%). Together, our results suggest that potential MM cure can be achieved with NMA transplantation regimens that maximize graft-versus-myeloma effect and minimize NRM.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Mieloma Múltiplo/mortalidade , Mieloma Múltiplo/terapia , Condicionamento Pré-Transplante , Adulto , Aloenxertos , Autoenxertos , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Taxa de Sobrevida
4.
J Dairy Sci ; 98(9): 6085-93, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26162795

RESUMO

Access to pasture has advantages for cows such as reduced lameness and improved udder health, but also may expose cows to stressors such as extreme heat. The objective of this study was to understand how portable shade affected physiological and behavioral responses of pastured dairy cows in a Canadian summer. Over 8wk, a total of 24 lactating Holstein cows were separated into 2 treatments, one with access to shade and a control without access to shade. The cows were pastured in groups of 4, with 3 field sections per treatment. Instantaneous scan sampling of behaviors (drinking, lying, grazing, other) performed in the shade or not were recorded every 5min for 3h/d during the hottest part of the day (peak hours: 1130-1530h) 3d/wk. Ambient temperature, humidity, and vaginal temperature were recorded at 10-min intervals. Daily milk production was also recorded. Differences between treatments by week were analyzed using the generalized linear mixed model with group as random effect and treatment as fixed effect. Cows with shade access were observed at the water trough up to 6.42 times less and lying down up to 1.75 times more. Cows with shade access grazed up to 1.5 times more but only when the temperature-humidity index was above their comfort threshold (≥72) during the hottest part of the day (wk 2). Cows sought shade when it was made available, but spent less than half of their time observed (%) in the shade (40.8±4.67) with the exception of wk 2 when most of the time was spent under the shade (74.3±4.77). Daily lying time was highest during peak hours for cows with shade access. However, no overall difference in total lying time between the 2 treatments was observed. No differences were found in vaginal temperature or milk production between treatments with the exception of wk 1 for daily milk production, which was higher for cows in the control treatment. In conclusion, cows sought shade when it was provided at pasture, whereas cows without access to shade seemed to alter their behavior to cope with heat stress, as seen from the lack of physiological differences between treatments. The results indicate that providing cows with access to pasture under a temperate climate does not seem to have any detrimental physiological or production effects and providing them with shade can potentially decrease production costs and help with water conservation strategies as fewer cows were observed at the water when shade was provided.


Assuntos
Bovinos/fisiologia , Transtornos de Estresse por Calor/veterinária , Animais , Comportamento Animal/fisiologia , Temperatura Corporal , Canadá , Feminino , Transtornos de Estresse por Calor/prevenção & controle , Temperatura Alta/efeitos adversos , Umidade , Lactação/fisiologia , Luz , Água/fisiologia
5.
Curr Oncol ; 21(2): e265-309, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24764712

RESUMO

Adult Philadelphia chromosome-positive (Ph+) or BCR-ABL-positive (BCR-ABL+) acute lymphoblastic leukemia (all) is an acute leukemia previously associated with a high relapse rate, short disease-free survival, and poor overall survival. In adults, allogeneic hematopoietic cell transplant in first remission remains the only proven curative strategy for transplant-eligible patients. The introduction of tyrosine kinase inhibitors (tkis) in the treatment of patients with Ph+ or BCR-ABL+ all has significantly improved the depth and duration of complete remission, allowing more patients to proceed to transplantation. Although tkis are now considered a standard of care in this setting, few randomized trials have examined the optimal use of tkis in patients with Ph+ all. Questions of major importance remain, including the best way to administer these medications, the choice of tki to administer, and the schedule and the duration to use. We present the results of a systematic review of the literature with consensus recommendations based on the available evidence.

6.
Med Vet Entomol ; 28(2): 193-200, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24382265

RESUMO

Plant essential oils (basil, geranium, balsam fir, lavender, lemongrass, peppermint, pine and tea tree), mixed with either sunflower oil or ethyl alcohol, were applied at 5% concentrations to the sides of Holstein cattle. Pastured cattle treated with essential oils diluted in sunflower oil had less flies than the untreated control for a 24-h period. However, the essential oil treatments were not significantly different than the carrier oil alone. Barn-held heifers treated with essential oils and sunflower oil alone had significantly less flies than the untreated control for up to 8 h after treatment. Basil, geranium, lavender, lemongrass and peppermint repelled more flies than sunflower oil alone for a period ranging from 1.5 to 4 h after treatments applied to heifers. All essential oils repelled > 75% of the flies on the treated area for 6 and 8 h on pastured cows and indoor heifers, respectively. Geranium, lemongrass and peppermint stayed effective for a longer duration. Essential oils mixed with ethyl alcohol demonstrated less repellence than when mixed with the carrier oil. Safer's soap, natural pyrethrins without piperonyl butoxide and ethyl alcohol alone were not efficient at repelling flies. Essential oils could be formulated for use as fly repellents in livestock production.


Assuntos
Controle de Insetos , Repelentes de Insetos , Inseticidas , Muscidae , Óleos Voláteis/farmacologia , Animais , Bovinos , Feminino , Repelentes de Insetos/farmacologia , Muscidae/efeitos dos fármacos , Óleos de Plantas , Óleo de Girassol
13.
Hematology ; 11(3): 165-70, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17325956

RESUMO

Early absolute lymphocyte count (ALC) has become an important end point for engraftment in patients undergoing autologous peripheral stem cell transplantation (APSCT). In this retrospective study, we evaluate the prognostic significance of early recovery of ALC ( > or = 0.5 cells x 10(9)/l on or before day 15) following APSCT in predicting transplant outcome in 72 patients with lymphoproliferative disorders, including non-Hodgkin's lymphoma (n = 30), Hodgkin's lymphoma (n = 8) and multiple myeloma (n = 34). The median quantities of CD34+ stem cells and lymphocytes infused were 4.97 x 10(6)/kg (range 0.64-11.7) and 11.3 x 10(7)/kg (range 1.11-110) respectively. After a median follow-up of 18 months (range 2-68), 28 patients had experienced a relapse and 16 had died. Of the 72 patients, 27 (37%) demonstrated early recovery of ALC. Early recovery of ALC was strongly associated with long-term overall and disease-free survival in patients aged less than 50 years (P < 0.001). In both univariate and multivariate survival analyses, a shorter time from diagnosis to APSCT was associated with early recovery of ALC (P = 0.03). These findings indicate that early recovery of ALC may contribute to longer survival in younger patients with lymphoproliferative disorders. A shorter time from diagnosis to APSCT may favor recovery of ALC independent of the infused stem cell or lymphocyte doses.


Assuntos
Contagem de Linfócitos , Transtornos Linfoproliferativos/cirurgia , Transplante de Células-Tronco de Sangue Periférico/estatística & dados numéricos , Adulto , Idoso , Intervalo Livre de Doença , Feminino , Seguimentos , Sobrevivência de Enxerto , Mobilização de Células-Tronco Hematopoéticas , Doença de Hodgkin/mortalidade , Doença de Hodgkin/cirurgia , Humanos , Estimativa de Kaplan-Meier , Linfoma não Hodgkin/mortalidade , Linfoma não Hodgkin/cirurgia , Transtornos Linfoproliferativos/mortalidade , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/mortalidade , Mieloma Múltiplo/cirurgia , Prognóstico , Recidiva , Estudos Retrospectivos , Condicionamento Pré-Transplante , Transplante Autólogo , Resultado do Tratamento
14.
Ann Rheum Dis ; 64(10): 1507-9, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16162903

RESUMO

BACKGROUND: Recent evidence supports an association between systemic lupus erythematosus (SLE) and non-Hodgkin's lymphoma (NHL). OBJECTIVES: To describe demographic factors, subtypes, and survival of patients with SLE who develop NHL. METHODS: A multi-site cohort of 9547 subjects with definite SLE was assembled. Subjects at each centre were linked to regional tumour registries to determine cancer cases occurring after SLE diagnosis. For the NHL cases ascertained, descriptive statistics were calculated, and NHL subtype frequency and median survival time of patients determined. RESULTS: 42 cases of NHL occurred in the patients with SLE during the 76,948 patient-years of observation. The median age of patients at NHL diagnosis was 57 years. Thirty six (86%) of the 42 patients developing NHL were women, reflecting the female predominance of the cohort. In the patients, aggressive histological subtypes appeared to predominate, with the most commonly identified NHL subtype being diffuse large B cell (11 out of 21 cases for which histological subtype was available). Twenty two of the patients had died a median of 1.2 years after lymphoma diagnosis. CONCLUSIONS: These data suggest aggressive disease in patients with SLE who develop NHL. Continuing work should provide further insight into the patterns of presentation, prognosis, and aetiology of NHL in SLE.


Assuntos
Lúpus Eritematoso Sistêmico/complicações , Linfoma não Hodgkin/etiologia , Adulto , Idoso , Feminino , Humanos , Lúpus Eritematoso Sistêmico/epidemiologia , Linfoma Difuso de Grandes Células B/epidemiologia , Linfoma Difuso de Grandes Células B/etiologia , Linfoma Difuso de Grandes Células B/genética , Linfoma não Hodgkin/epidemiologia , Linfoma não Hodgkin/genética , Masculino , Pessoa de Meia-Idade , Prognóstico , Sistema de Registros , Análise de Sobrevida
15.
Transplantation ; 64(8): 1147-52, 1997 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-9355832

RESUMO

BACKGROUND: Acute graft-versus-host disease (aGVHD) is still one of the main causes of morbidity and mortality after allogeneic bone marrow transplantation. Attempts to avoid GVHD are associated with an increased risk of relapse, probably because the graft-versus-leukemia effect is also abrogated. It was recently suggested that a high frequency of host-specific donor helper T cell precursors (HTLp) might be predictive of significant aGVHD (grade > or = II). METHODS: We retrospectively studied the frequency of HTLp by means of simplified limiting-dilution analysis to determine its predictive value for aGVHD and relapse. Pre-bone marrow transplantation, host-specific donor HLTp frequencies were analyzed in 32 patients who had received marrow from HLA-identical siblings for hematological malignancies, in terms of aGVHD and relapse. RESULTS: HTLp frequencies were significantly higher in patients who had aGVHD > or = grade II (n=14) than in those without aGVHD (n=18) (P=0.007). Patients who relapsed (n=13) had significantly lower HTLp frequencies than those who did not relapse (n=19) (P<0.0001). The probabilities of relapse (Kaplan-Meier method) when the HTLp frequency was higher and lower than 1/200,000 were 0% and 88%, respectively (P<0.0001). CONCLUSIONS: The definition of HTLp cut-off values predictive of aGVHD and relapse should contribute to donor selection and could open the way to protocols adapting immunomodulation to the likely risk of aGVHD and relapse.


Assuntos
Transplante de Medula Óssea/imunologia , Antígenos HLA/sangue , Neoplasias Hematológicas/imunologia , Neoplasias Hematológicas/terapia , Células-Tronco/citologia , Linfócitos T Auxiliares-Indutores/citologia , Adolescente , Criança , Feminino , Doença Enxerto-Hospedeiro/prevenção & controle , Humanos , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Condicionamento Pré-Transplante
16.
J Am Soc Nephrol ; 8(7): 1072-9, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9219156

RESUMO

It has been reported previously that the addition of isoproterenol or forskolin stimulates the expression of the angiotensinogen (ANG) gene in opossum kidney (OK) 27 cells, an OK cell line with a fusion gene containing the 5'-flanking regulatory sequence of the rat ANG gene fused with a human growth hormone (hGH) gene as a reporter, pOGH (ANG N-1498/+18), permanently integrated into their genomes. To investigate whether the effect of isoproterenol or forskolin on the expression of the ANG gene is mediated via the nuclear 43-kD cAMP-responsive element binding protein (CREB), OK 27 cells were transiently transfected with an expression plasmid containing the cDNA for the 43-kD CREB (pRSV/CREB). The level of expression of the pOGH (ANG N-1498/+18) in OK 27 cells was estimated by the amount of immunoreactive hGH secreted into the culture medium. Transfection of pRSV/CREB alone stimulated the expression of pOGH (ANG N-1498/+18). The addition of isoproterenol or forskolin further enhanced the stimulatory effect of pRSV/ CREB on the expression of pOGH (ANG N-1498/+18). The enhancing effect of isoproterenol was inhibited by the presence of propranolol (an inhibitor of beta-adrenoceptors) and (R)-p-adenosine 3'5'-cyclic monophospho-orthioate (Rp)-cAMP (an inhibitor of cAMP-dependent protein kinase A I and II). Transfection of pRSV/CREB had no effect on the expression of thymidine kinase growth hormone in OK 13 cells, an OK cell line with a fusion gene containing the promoter/enhancer DNA sequence of the viral thymidine-kinase gene fused with an hGH gene as a reporter, thymidine kinase growth hormone, permanently integrated into their genomes. These studies demonstrate that isoproterenol stimulates the expression of ANG gene via the cAMP-dependent protein kinase A and probably via the interaction of the 43-kD CREB with the 5'-flanking region of the ANG gene. Our data indicate that the nuclear 43-kD CREB may have a modulatory role on the expression of the ANG gene in OK cells.


Assuntos
Angiotensinogênio/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Rim/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Animais , Sequência de Bases , Linhagem Celular , Colforsina/farmacologia , AMP Cíclico/análogos & derivados , AMP Cíclico/farmacologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Primers do DNA/genética , DNA Complementar/genética , Expressão Gênica/efeitos dos fármacos , Genes Reporter , Hormônio do Crescimento Humano/genética , Humanos , Isoproterenol/farmacologia , Rim/efeitos dos fármacos , Gambás , Propranolol/farmacologia , Ratos , Tionucleotídeos/farmacologia , Transfecção
17.
Biochem J ; 321 ( Pt 3): 897-901, 1997 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-9032481

RESUMO

We examined whether NO and H2O2 could interact in inducing DNA fragmentation and cell death. H2O2 and the NO-releasing compounds sodium nitroprusside (SNP) and S-nitroso-N-acetyl-D,L-penicillamine (SNAP) by themselves elicited lysis of YAC-1 murine lymphoma cells in a concentration-dependent manner. Exposure of the cells to a combination of sublytic concentrations of SNP (0.78 mM) plus H2O2 (7.8 microM) or SNAP (0.18 mM) plus H2O2 (7.8 microM) resulted in cell death which is mediated, in part, through apoptosis. Evidence for this direction is provided by fluorescence microscopic evaluation of the cells, which revealed the presence of changes in nuclear morphology characteristic of apoptosis in 30-40% of lymphoma cells and by the specific pattern of internucleosomal DNA fragmentation detected by gel electrophoresis. The cytotoxic effect of SNP plus H2O2 could be effectively inhibited by either oxyhaemoglobin, which binds NO, or catalase, which eliminates H2O2. Partial protection from SNP-plus-H2O2-induced cell lysis was observed with the poly(ADP-ribose) polymerase inhibitors, nicotinamide and 3-aminobenzamide, parallelling their ability to reverse depletion of cellular NAD+ pools. These results indicate an interaction between NO and H2O2 which leads to a markedly enhanced cytotoxic activity, in part, via induction of apoptosis and suggest that poly(ADP-ribosylation) and subsequent NAD+ depletion mediate, at least in part, this cytotoxic activity.


Assuntos
Morte Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Óxido Nítrico/metabolismo , Animais , Apoptose/efeitos dos fármacos , Núcleo Celular/efeitos dos fármacos , Eletroforese em Gel de Ágar , Linfoma/metabolismo , Camundongos , NAD/análise , Neoplasias Experimentais , Nitroprussiato/farmacologia , Nucleossomos/efeitos dos fármacos , Penicilamina/análogos & derivados , Penicilamina/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases , Espécies Reativas de Oxigênio/metabolismo , S-Nitroso-N-Acetilpenicilamina , Células Tumorais Cultivadas
18.
Am J Physiol ; 271(3 Pt 2): R519-27, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8853371

RESUMO

To investigate whether expression of the renal angiotensinogen gene is regulated by dopaminergic receptors, we used opossum kidney (OK 27) cells with a fusion gene containing the 5'- flanking regulatory sequence of the rat angiotensinogen gene fused with a human growth hormone (hGH) gene as a reporter [pOGH, angiotensinogen nucleotide (N) -1498/+18], permanently integrated into their genomes. The level of expression of pOGH (angiotensinogen N-1498/+18) in OK 27 was evaluated by the amount of immunoreactive hGH (ir-hGH) secreted into the culture medium. In the absence of 3-isobutyl-1-methylxanthine (IBMX), addition of dopamine (10(-13) to 10(-5)M) had minimal effect on the expression of the pOGH (angiotensinogen N-1498/+18) in OK 27 cells. In the presence of IBMX, addition of low concentrations (10(-13) and 10(-7) M) of dopamine stimulated the expression of pOGH angiotensinogen N-1498/+18) in OK 27 cells in a dose-dependent manner, whereas high concentrations (i.e., > 10(-7) M) had minimal effect. The stimulatory effect of dopamine on the expression of pOGH (angiotensinogen N-1498/+18) was inhibited by the presence of SCH-23390 (D1-dopaminergic receptor antagonist) and spiperone (D2-dopaminergic receptor antagonist), but not by ketanserin (5 HT2/5HT1c-serotonergic receptor antagonist). Moreover, the stimulatory effect of dopamine was inhibited by the presence of U-73122 (an inhibitor of phospholipase C and phospholipase A2) or staurosporine (an inhibitor of protein kinase C) or (R)-p-adenosine 3',5'-cyclic monophosphorothioate (Rp-cAMP[S]; an inhibitor of cAMP-dependent protein kinase AI and II). Addition of low concentrations (10(-13) to 10(-9)M) of SKF-82958 (D1-dopaminergic receptor agonist) or PPHT (D2-dopaminergic receptor agonist) also stimulated the expression of pOGH (angiotensinogen N-1498/+18). The stimulatory effect of SKF-82958 was inhibited by the presence of SCH-23390 or Rp-cAMP[S], whereas the effect of PPHT was inhibited by the presence of spiperone or staurosporine. These studies demonstrate that the expression of pOGH (angiotensinogen N-1498/+18) in OK 27 cells is modulated by dopaminergic receptor agonists.


Assuntos
Angiotensinogênio/genética , Expressão Gênica , Rim/metabolismo , Rim/fisiologia , Receptores Dopaminérgicos/fisiologia , 1-Metil-3-Isobutilxantina/farmacologia , Angiotensinogênio/metabolismo , Animais , Linhagem Celular , Dopamina/farmacologia , Agonistas de Dopamina/farmacologia , Antagonistas de Dopamina/farmacologia , Expressão Gênica/efeitos dos fármacos , Humanos , Rim/citologia , Gambás , Fragmentos de Peptídeos/metabolismo , Ratos
19.
Blood ; 87(12): 5136-43, 1996 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-8652826

RESUMO

Although it has been recognized for sometime that target cells destroyed by natural killer (NK) cells die largely by apoptosis, the underlying mechanisms are not fully understood. The aim of the present study was to examine the role of nitric oxide (NO) in mediating murine NK-cell-induced killing of YAC-1 lymphoma cells. NK calls induced extensive release of 125I-DNA and 51Cr from YAC-1 cells. The target killing ability of NK cells was associated with an increased production of NO as measured by concentrations of nitrite in the culture medium. That YAC-1 killing resulted, in part, from the production of NO was confirmed by the significant protection of cell lysis in L-arginine-depleted medium and by approximately 30 % attenuation of cell lysis and DNA fragmentation by an inhibitor of NO synthase, NG-nitro-L-arginine methyl ester (L-NAME) in a culture medium containing 1 mmol/L L-arginine. Fluorescence microscopic examination of YAC-1 cells showed the presence of changes in nuclear morphology characteristic for apoptosis. The percentage of apoptotic cells was markedly decreased by L-NAME. Further evidence for apoptosis is provided by the specific pattern of internucleosomal DNA fragmentation both in the absence and presence of L-NAME. During target-cell killing, an increased oxidation of intracellularly trapped dichlorofluorescein was observed in cells labeled with an antimouse NK-cell monoclonal antibody, as measured by flow cytometry. These increases were effectively prevented by L-NAME, but not W-13, an inhibitor of calmodulin. The ability of NO to induce cell lysis and DNA fragmentation in YAC-1 cells was further demonstrated by exposing tumor cells to chemically generated NO. Taken together, these observations suggest a role for NO as one of the mediators of NK-cell-mediated DNA fragmentation and cell lysis.


Assuntos
Apoptose/fisiologia , Citotoxicidade Imunológica/fisiologia , Dano ao DNA , Células Matadoras Naturais/imunologia , Óxido Nítrico/fisiologia , Animais , Arginina/análogos & derivados , Arginina/farmacologia , Calmodulina/antagonistas & inibidores , DNA de Neoplasias/análise , Inibidores Enzimáticos/farmacologia , Linfoma/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NG-Nitroarginina Metil Éster , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase/antagonistas & inibidores , Nitroprussiato/farmacologia , Sulfonamidas/farmacologia , Células Tumorais Cultivadas
20.
Kidney Int ; 48(1): 139-45, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7564070

RESUMO

To investigate whether alpha (alpha)-adrenoceptor agonists have a stimulatory effect on the expression of the angiotensinogen (Ang) gene in opossum kidney (OK) cells, we used OK 27 cells with a fusion gene containing the 5'-flanking regulatory sequence of the rat angiotensinogen gene fused with a human growth hormone (hGH) gene as a reporter, pOGH (Ang N-1498/+18), permanently integrated into their genomes. The level of expression of the pOGH (Ang N-1498/+18) was quantitated by the amount of immunoreactive-human growth hormone (IR-hGH) secreted into the medium. The addition of iodoclonidine (alpha 2-adrenoceptor agonist, 10(-13) to 10(-9) M) and phorbol 12-myristate 13-acetate (PMA, 10(-13) to 10(-5) M) stimulated the expression of pOGH (Ang N-1498/+18) in a dose-dependent manner, whereas the addition of phenylephrine (alpha 1-adrenoceptor agonist, 10(-13) to 10(-5) M) had no effect. The stimulatory effect of iodoclonidine was blocked by the presence of yohimbine (alpha 2-adrenoceptor antagonist) and staurosporine (an inhibitor of protein kinase C) but not blocked by the presence of prazosin (alpha 1-adrenoceptor antagonist) or Rp-cAMP (an inhibitor of cAMP-dependent protein kinase A). The addition of iodoclonidine, phenylephrine or PMA had no effect on the expression of pTKGH in OK 13 cells, an OK cell line, into which had been stably integrated a fusion gene, pTKGH containing the promoter/enhancer DNA sequence of the viral thymidine-kinase (TK) gene fused with a human growth hormone gene as a reporter.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Agonistas alfa-Adrenérgicos/farmacologia , Angiotensinogênio/biossíntese , Túbulos Renais/metabolismo , Receptores Adrenérgicos alfa/biossíntese , Marcadores de Afinidade , Alcaloides/farmacologia , Angiotensinogênio/efeitos dos fármacos , Angiotensinogênio/genética , Animais , Células Cultivadas , Clonidina/análogos & derivados , Clonidina/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Regulação da Expressão Gênica/efeitos dos fármacos , Túbulos Renais/citologia , Túbulos Renais/efeitos dos fármacos , Gambás , Fenilefrina/farmacologia , Prazosina/farmacologia , Proteína Quinase C/antagonistas & inibidores , Receptores Adrenérgicos alfa/efeitos dos fármacos , Receptores Adrenérgicos alfa/genética , Estaurosporina , Acetato de Tetradecanoilforbol/farmacologia , Ioimbina/farmacologia
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