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1.
Actas urol. esp ; 43(7): 364-370, sept. 2019. tab
Artigo em Espanhol | IBECS | ID: ibc-192173

RESUMO

Introducción y objetivo: Nivolumab es un agente inmunoterapéutico aprobado para el tratamiento de pacientes con carcinoma de células renales (CCR) avanzado tratados previamente. La experiencia en práctica clínica real, especialmente en lo referente a la aparición de reacciones adversas inmunorrelacionadas, es escasa. Presentamos la experiencia acerca de la seguridad de nivolumab en pacientes con CCR metastásico (CCRm) tratados en 9 hospitales de España. Material y métodos: Estudio retrospectivo, multicéntrico en pacientes con CCRm tratados con nivolumab entre 2016 y 2018. Se recogieron datos sociodemográficos y clínicos basales y las reacciones adversas relacionadas con el fármaco. Resultados: Los 26 pacientes incluidos presentaron una edad de 63,7 ± 11,5 años. El 96% presentaba ECOG 0-1 y el 78% un riesgo MKSCC favorable/intermedio. El 73% presentaba subtipo histológico de células claras y el 30%, metástasis de inicio. La mediana de seguimiento fue de 9 meses (rango: 1-14). El 100% de los pacientes presentó una reacción adversa de cualquier grado; las más frecuentes fueron la fatiga, la fiebre y la anemia (27%). El 23% presentó una reacción adversa de grado 3. Las reacciones adversas llevaron a la suspensión del tratamiento en 3 pacientes (11%). Conclusión: En la práctica clínica real, nivolumab presenta un perfil de seguridad favorable y manejable, similar al descrito en otros estudios


Introduction and objectives: Nivolumab is an immunotherapy agent that has been an approved treatment for previously treated patients with advanced renal cell carcinoma (RCC). Experience in real-life settings, especially regarding immune- related adverse events, is scarce. We present our experience with reference to the safety of nivolumab in patients with metastatic RCC (mRCC) treated in 9 hospitals in Spain. Material and methods: Retrospective, multicentre study of patients with mRCC treated with nivolumab between 2016 and 2018. Data on baseline socio-demographic and clinical characteristics and drug-related adverse events were collected. Results: The mean age of the 26 patients included was 63.7 ± 11.5 years; 96% were ECOG 0-1 and 78% had favourable or intermediate MSKCC risk scores; 73% had the clear cell histological subtype and 30% metastatic disease. Median follow-up was 9 months (range 1-14). All patients experienced an adverse event at different grades, with fatigue, fever and anaemia being the most common (27%). Grade 3 adverse events occurred in 23% of patients. Adverse reactions led to treatment suspension in 3 patients (11%). Conclusion: In the real-life clinical setting, nivolumab shows favourable outcomes, similar to those reported by other studies


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Nivolumabe/uso terapêutico , Antineoplásicos Imunológicos/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Neoplasias Renais/tratamento farmacológico , Metástase Neoplásica , Antineoplásicos Imunológicos/efeitos adversos , Estadiamento de Neoplasias , Fatores Socioeconômicos , Estudos Retrospectivos , Seguimentos , Nivolumabe/efeitos adversos
2.
Actas Urol Esp (Engl Ed) ; 43(7): 364-370, 2019 Sep.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31097211

RESUMO

INTRODUCTION AND OBJECTIVES: Nivolumab is an immunotherapy agent that has been an approved treatment for previously treated patients with advanced renal cell carcinoma (RCC). Experience in real-life settings, especially regarding immune- related adverse events, is scarce. We present our experience with reference to the safety of nivolumab in patients with metastatic RCC (mRCC) treated in 9 hospitals in Spain. MATERIAL AND METHODS: Retrospective, multicentre study of patients with mRCC treated with nivolumab between 2016 and 2018. Data on baseline socio-demographic and clinical characteristics and drug-related adverse events were collected. RESULTS: The mean age of the 26 patients included was 63.7±11.5 years; 96% were ECOG 0-1 and 78% had favourable or intermediate MSKCC risk scores; 73% had the clear cell histological subtype and 30% metastatic disease. Median follow-up was 9 months (range 1-14). All patients experienced an adverse event at different grades, with fatigue, fever and anaemia being the most common (27%). Grade 3 adverse events occurred in 23% of patients. Adverse reactions led to treatment suspension in 3 patients (11%). CONCLUSION: In the real-life clinical setting, nivolumab shows favourable outcomes, similar to those reported by other studies.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Neoplasias Renais/tratamento farmacológico , Nivolumabe/uso terapêutico , Adulto , Idoso , Antineoplásicos Imunológicos/efeitos adversos , Carcinoma de Células Renais/secundário , Feminino , Humanos , Neoplasias Renais/patologia , Masculino , Pessoa de Meia-Idade , Nivolumabe/efeitos adversos , Estudos Retrospectivos , Espanha
4.
Urol Case Rep ; 13: 48-50, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28443242

RESUMO

We hereby present the case of a 55 years old patient with clinical diagnosis of high-risk prostate cancer T2bN1Mo Gleason 9 (4 + 5) treated with androgen deprivation therapy and external beam radiotherapy. Despite treatment, castration levels were not achieved and clinical progression was evidenced by the appearance of bone metastases and progression of PSA. After several hormonal treatments without any PSA or testosterone response, surgical castration was performed by bilateral orchiectomy. The pathology results showed an incidental Leydig cell tumor in the right testicle.

5.
Rev. esp. investig. quir ; 15(1): 25-26, ene.-mar. 2012. ilus
Artigo em Espanhol | IBECS | ID: ibc-99590

RESUMO

Presentamos un caso de ileo biliar colónico secundario a fístula colecistocolónica en una mujer de 76 años con clínica de obstrucción intestinal. Se denomina íleo biliar a la obstrucción mecánica del intestino delgado o del colon como consecuencia del paso de una o más litiasis a través de una fístula biliodigestiva. Únicamente entre 1-15 % de estas fístulas producen cuadro de obstrucción intestinal siendo la más frecuente la colecistoduodenal (65-77%) (AU)


We report a case of colonic gallstone ileus secondary a cholecystocolonic fistula. An 76-years-old woman was admitted to the hospital because she had been symptoms of intestinal obstruction. Colonic gallstone ileus is a rare cause of mechanical large bowel obstruction. It occurs most commonly of a passage of one or more stones through biliodigestive fistula. Only between 1-15% of these fistulas pruduce bowel obstruction. The most frequent fistula is cholecystoduodenal (65-77%) (AU)


Assuntos
Humanos , Feminino , Idoso , Íleus/etiologia , Fístula Intestinal/complicações , Obstrução Intestinal/complicações , Colestase/complicações
6.
Transplant Proc ; 43(3): 742-4, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21486588

RESUMO

BACKGROUND: Incisional hernia is a frequent problem after liver transplantation. It is related to immunosuppression, use of steroids, obesity, as well as the type of incision. Laparoscopic repair shows a lower rate of complications in terms of infection and recurrence, as well as reduced postoperative pain and faster recovery. METHODS: We reviewed our experience with laparoscopic incisional hernia repair (LIHR) in patients after liver transplantation, using the BARD Composix mesh which is composed of two layers of polypropylene and polytetrafluoroethylene (PTFE) and fixed with metal ProTack. RESULTS: Between March 2002 and April 2010, we performed 20 LIHR in 17 male and three female subjects of overall mean age of 58.3 years, and body mass Index of 31.05 kg/m(2). The mean size of the defects was 215.25 cm(2). All patients had undergone bilateral subcostal incisions with a midline extension, and seven had additional operations after the transplantation for various reasons. There were no differences in immunosuppression. Three patients had needed steroid boluses for acute graft rejection episodes. There was no conversion of therapy. The size of mesh was 18 × 23 cm in seven cases and 20 × 25 in 12 cases. The mean postoperative hospital stay was 2.1 days. Oral feeding was initiated a few hours after surgery, and routine immunosuppression was not discontinued. There were no major early complications. During follow-up, we identified one patient with a mesh infection (5%) and one with a recurrence (5%). CONCLUSION: LIHR is safe and feasible even for major hernias after liver transplantation with few complications.


Assuntos
Herniorrafia , Laparoscopia/estatística & dados numéricos , Transplante de Fígado/efeitos adversos , Adulto , Estudos de Viabilidade , Feminino , Hérnia/etiologia , Humanos , Laparoscopia/normas , Masculino , Pessoa de Meia-Idade
7.
Biochemistry ; 40(7): 2260-6, 2001 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-11329295

RESUMO

The outer mitochondrial membrane enzyme carnitine palmitoyltransferase I (CPTI) catalyzes the initial and regulatory step in the beta-oxidation of fatty acids. The genes for the two isoforms of CPTI-liver (L-CPTI) and muscle (M-CPTI) have been cloned and expressed, and the genes encode for enzymes with very different kinetic properties and sensitivity to malonyl-CoA inhibition. Pig L-CPTI encodes for a 772 amino acid protein that shares 86 and 62% identity, respectively, with rat L- and M-CPTI. When expressed in Pichia pastoris, the pig L-CPTI enzyme shows kinetic characteristics (carnitine, K(m) = 126 microM; palmitoyl-CoA, K(m) = 35 microM) similar to human or rat L-CPTI. However, the pig enzyme, unlike the rat liver enzyme, shows a much higher sensitivity to malonyl-CoA inhibition (IC(50) = 141 nM) that is characteristic of human or rat M-CPTI enzymes. Therefore, pig L-CPTI behaves like a natural chimera of the L- and M-CPTI isotypes, which makes it a useful model to study the structure--function relationships of the CPTI enzymes.


Assuntos
Carnitina O-Palmitoiltransferase/antagonistas & inibidores , Carnitina O-Palmitoiltransferase/metabolismo , Carnitina/análogos & derivados , Carnitina/metabolismo , Inibidores Enzimáticos/metabolismo , Malonil Coenzima A/metabolismo , Mitocôndrias Hepáticas/enzimologia , Mitocôndrias Musculares/enzimologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Carnitina O-Palmitoiltransferase/biossíntese , Carnitina O-Palmitoiltransferase/genética , Clonagem Molecular , DNA Complementar/isolamento & purificação , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/biossíntese , Isoenzimas/genética , Isoenzimas/metabolismo , Cinética , Camundongos , Dados de Sequência Molecular , Especificidade de Órgãos/genética , Pichia/genética , Ratos , Alinhamento de Sequência , Suínos
8.
Arch Biochem Biophys ; 385(2): 364-71, 2001 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-11368018

RESUMO

The unusually low hepatic ketogenic capacity of piglets has been correlated with lack of expression of the mitochondrial HMG-CoA synthase gene. However, we have shown that starvation of 2-week-old piglets increased the mRNA levels of mitochondrial HMG-CoA synthase to a level similar to that observed in starved rats (S. H. Adams, C. S. Alho, G. Asins, F. G. Hegardt, and P. F. Marrero, 1997, Biochem. J. 324, 65-73). We now report that antibodies against pig mitochondrial HMG-CoA synthase detected the pig enzyme in mitochondria of 2-week-old starved piglets and that the pig mitochondrial HMG-CoA synthase cDNA encodes an active enzyme in the eukaryotic cell line Mev-1, with catalytic behavior similar to that of the rat enzyme when expressed in the same system. We also show that low activity of pig mitochondrial HMG-CoA synthase correlates with low expression of the pig enzyme. The discrepancy in mitochondrial HMG-CoA synthase gene expression between the high levels of mRNA and low levels of enzyme was not associated with differences in transcript maturation, which suggests that an attenuated translation of the pig mRNA is responsible for the diminished ketogenic capacity of pig mitochondria.


Assuntos
Compostos de Boro/farmacologia , Coenzima A Ligases/genética , Coenzima A Ligases/metabolismo , Regulação Enzimológica da Expressão Gênica , Fígado/enzimologia , Mitocôndrias/enzimologia , Biossíntese de Proteínas/genética , Inanição/enzimologia , Animais , Anticorpos/imunologia , Western Blotting , Compostos de Boro/química , Células CHO , Catálise , Coenzima A Ligases/imunologia , Cricetinae , Dosagem de Genes , Fígado/metabolismo , Mitocôndrias/metabolismo , Ensaios de Proteção de Nucleases , Processamento Pós-Transcricional do RNA , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Ribonuclease H/metabolismo , Inanição/genética , Suínos
9.
Insect Biochem Mol Biol ; 31(4-5): 425-33, 2001 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-11222952

RESUMO

Blattella germanica has two cytosolic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase genes, HMG-CoA synthase-1 and -2. HMG-CoA synthase-1 gene shows several features of processed genes (retroposons): it contains no introns but has a short direct-repeat sequence (ATTATTATT) at both ends. An atypical feature is the presence at both ends of the gene of short inverse repeats flanked by direct repeats. There is neither a TATA box nor a CAAT box in the 5' region. Comparative analysis with other species suggests that the HMG-CoA synthase-1 gene derives from HMG-CoA synthase-2. Cultured embryonic B. germanica UM-BGE-1 cells express HMG-CoA synthase-1 but not HMG-CoA synthase-2, suggesting that the intron-less gene is functional. In addition, it can complement MEV-1 cell line, which is auxotrophic for mevalonate. We show that compactin and mevalonate do not significantly affect the mRNA levels of HMG-CoA synthase-1 in UM-BGE-1 cells. Compactin induces a 6.7-fold increase in HMG-CoA reductase activity, which is restored to normal levels by mevalonate. HMG-CoA synthase activity is not modified by either of these effectors, suggesting that the mevalonate pathway in this insect cell line is regulated by post-transcriptional mechanisms affecting HMG-CoA reductase but not HMG-CoA synthase.


Assuntos
Baratas/genética , Genes de Insetos , Proteínas de Insetos/genética , Lovastatina/análogos & derivados , Retroelementos , Animais , Sequência de Bases , Baratas/citologia , Baratas/enzimologia , Regulação Enzimológica da Expressão Gênica , Hidroximetilglutaril-CoA Redutases/biossíntese , Hidroximetilglutaril-CoA Redutases/genética , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Hidroximetilglutaril-CoA Sintase/biossíntese , Hidroximetilglutaril-CoA Sintase/genética , Íntrons , Lovastatina/farmacologia , Ácido Mevalônico/metabolismo , Dados de Sequência Molecular , Especificidade da Espécie
10.
Biochem Biophys Res Commun ; 279(1): 81-8, 2000 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-11112421

RESUMO

L-CPT I isotype is the main locus of control for liver LCFA oxidation. T3 levels have been described as controlling L-CPT I gene expression, and in this paper we demonstrate that rat liver CPT I promoter responds to T3. Using deleted reporter constructs we located the thyroid hormone-responsive element between -2935 and -2918, consisting of a DR4. This response is mediated by the binding of the thyroid to this sequence as a monomer, homodimer, or heterodimer with RXR.


Assuntos
Carnitina O-Palmitoiltransferase/genética , Regulação Enzimológica da Expressão Gênica/fisiologia , Transcrição Gênica/fisiologia , Tri-Iodotironina/fisiologia , Animais , Sequência de Bases , Linhagem Celular , Primers do DNA , Regiões Promotoras Genéticas , Ratos
11.
Biochem J ; 350 Pt 3: 785-90, 2000 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-10970793

RESUMO

Steroidogenic factor 1 (SF-1) is an orphan member of the nuclear receptor family expressed in steroidogenic tissues, where it has an essential role in the regulation of the steroid hormone biosynthesis, adrenal and gonadal development and endocrine responses fundamental for reproduction. Here we show that SF-1 regulates the transcription of cytosolic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase gene, which is essential for the endogenous synthesis of cholesterol. We have identified an element located 365 bp upstream of the gene for cytosolic HMG-CoA synthase; SF-1 binds as a monomer to this element and confers SF-1 responsiveness to homologous and heterologous promoters. It has been shown that in tissues with a high demand for cholesterol to be used in steroid synthesis, there is a lack of correlation between the cholesterol levels and the activity of the limiting enzymes of the mevalonate pathway. In accord with those results, we observed that cholesterol synthesis from acetate and either cytosolic HMG-CoA mRNA expression or transcriptional activity were not changed in response to 25-hydroxycholesterol in the SF-1-expressing steroidogenic Leydig tumour MA-10 cells. Moreover, the overexpression of SF-1 in non-steroidogenic CV-1 cells renders them less sensitive to the regulatory effects of cholesterol. This observation led to the hypothesis that in steroidogenic tissues the expression of SF-1 permits high levels of endogenous synthesis of cholesterol irrespective of the intracellular levels of this metabolite.


Assuntos
Colesterol/biossíntese , Proteínas de Ligação a DNA/fisiologia , Fatores de Transcrição/fisiologia , Animais , Sequência de Bases , Sítios de Ligação , Linhagem Celular , Cricetinae , Citosol/enzimologia , Primers do DNA , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição Fushi Tarazu , Proteínas de Homeodomínio , Hidroxicolesteróis/farmacologia , Hidroximetilglutaril-CoA Sintase/genética , Receptores Citoplasmáticos e Nucleares , Fator Esteroidogênico 1 , Fatores de Transcrição/metabolismo , Transcrição Gênica/fisiologia
12.
Biochem J ; 337 ( Pt 2): 329-35, 1999 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-9882632

RESUMO

Low expression of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase gene during development correlates with an unusually low hepatic ketogenic capacity and lack of hyperketonaemia in piglets. Here we report the isolation and characterization of the 5' end of the pig mitochondrial HMG-CoA synthase gene. The 581 bp region proximal to the transcription start site permits transcription of a reporter gene, confirming the function of the promoter. The pig mitochondrial HMG-CoA synthase promoter is trans-activated by the peroxisomal proliferator-activated receptor (PPAR), and a functional response element for PPAR (PPRE) has been localized in the promoter region. Pig PPRE is constituted by an imperfect direct repeat (DR-1) and a downstream sequence, both of which are needed to confer PPAR-sensitivity to a thymidine kinase promoter and to form complexes with PPAR.retinoid X receptor heterodimers. A role of PPAR trans-activation in starvation-associated induction of gene expression is suggested.


Assuntos
Hidroximetilglutaril-CoA Sintase/genética , Proliferadores de Peroxissomos/metabolismo , Regiões Promotoras Genéticas , Elementos de Resposta , Suínos/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Metabolismo dos Lipídeos , Mitocôndrias/enzimologia , Modelos Genéticos , Dados de Sequência Molecular , Ligação Proteica , Receptores do Ácido Retinoico/metabolismo , Receptores X de Retinoides , Especificidade da Espécie , Fatores de Transcrição/metabolismo , Ativação Transcricional
14.
J Biol Chem ; 273(15): 8560-3, 1998 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-9535828

RESUMO

The expression of several genes involved in intra- and extracellular lipid metabolism, notably those involved in peroxisomal and mitochondrial beta-oxidation, is mediated by ligand-activated receptors, collectively referred to as peroxisome proliferator-activated receptors (PPARs). To gain more insight into the control of expression of carnitine palmitoyltransferase (CPT) genes, which are regulated by fatty acids, we have examined the transcriptional regulation of the human MCPT I gene. We have cloned by polymerase chain reaction the 5'-flanking region of this gene and demonstrated its transcriptional activity by transfection experiments with the CAT gene as a reporter. We have also shown that this is a target gene for the action of PPARs, and we have localized a PPAR responsive element upstream of the first exon. These results show that PPAR regulates the entry of fatty acids into the mitochondria, which is a crucial step in their metabolism, especially in tissues like heart, skeletal muscle and brown adipose tissue in which fatty acids are a major source of energy.


Assuntos
Carnitina O-Palmitoiltransferase/biossíntese , Carnitina O-Palmitoiltransferase/genética , Músculo Esquelético/enzimologia , Receptores Citoplasmáticos e Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica/fisiologia , Animais , Sequência de Bases , Linhagem Celular , Cloranfenicol O-Acetiltransferase/biossíntese , Sequência Consenso , Éxons , Regulação Enzimológica da Expressão Gênica , Genes Reporter , Humanos , Isoenzimas/biossíntese , Camundongos , Regiões Promotoras Genéticas , Receptores Citoplasmáticos e Nucleares/biossíntese , Proteínas Recombinantes de Fusão/biossíntese , Sequências Reguladoras de Ácido Nucleico , Alinhamento de Sequência , Fatores de Transcrição/biossíntese , Transfecção
15.
Insect Biochem Mol Biol ; 27(6): 499-505, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9304791

RESUMO

Blattella germanica is the first organism in which two cytosolic HMG-CoA synthase genes have been described: HMGS-1 (Martínez-González et al., 1993b) and HMGS-2 (Buesa et al., 1994). The HMGS-1 gene showed special features, which led us to characterize the kinetic properties of the enzyme it encodes. Here we report the expression of recombinant HMGS-1, the protocol of enzyme purification, and the measurement of kinetic parameters. The K(m) for acetyl-CoA is 15.2 microM and the Ki for the other substrate, acetoacetyl-CoA, is 1.26 microM, both similar to that of yeast, ox, and chicken liver enzymes; the Vmax of HMGS-1 measured in this paper is 66 mU, which is the lowest Vmax of the HMG-CoA synthases reported to date.


Assuntos
Baratas/enzimologia , Hidroximetilglutaril-CoA Sintase/metabolismo , Animais , Catálise , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos , Hidroximetilglutaril-CoA Sintase/genética , Hidroximetilglutaril-CoA Sintase/isolamento & purificação , Cinética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/metabolismo
16.
Biochem J ; 324 ( Pt 1): 65-73, 1997 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-9164842

RESUMO

The low ketogenic capacity of pigs correlates with a low activity of mitochondrial 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase. To identify the molecular mechanism controlling such activity, we isolated the pig cDNA encoding this enzyme and analysed changes in mRNA levels and mitochondrial specific activity induced during development and starvation. Pig mitochondrial synthase showed a tissue-specific expression pattern. As with rat and human, the gene is expressed in liver and large intestine; however, the pig differs in that mRNA was not detected in testis, kidney or small intestine. During development, pig mitochondrial HMG-CoA synthase gene expression showed interesting differences from that in the rat: (1) there was a 2-3 week lag in the postnatal induction; (2) the mRNA levels remained relatively abundant through the suckling-weaning transition and at maturity, in contrast with the fall observed in rats at similar stages of development; and (3) the gene expression was highly induced by fasting during the suckling, whereas no such change in mitochondrial HMG-CoA synthase mRNA levels has been observed in rat. The enzyme activity of mitochondrial HMG-CoA synthase increased 27-fold during starvation in piglets, but remained one order of magnitude lower than rats. These results indicate that post-transcriptional mechanism(s) and/or intrinsic differences in the encoded enzyme are responsible for the low activity of pig HMG-CoA synthase observed throughout development or after fasting.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Hidroximetilglutaril-CoA Sintase/biossíntese , Mitocôndrias Hepáticas/enzimologia , Mitocôndrias/enzimologia , Inanição/enzimologia , Envelhecimento/metabolismo , Sequência de Aminoácidos , Animais , Animais Recém-Nascidos , Sequência de Bases , Primers do DNA , DNA Complementar , Feminino , Humanos , Hidroximetilglutaril-CoA Sintase/química , Fígado/crescimento & desenvolvimento , Masculino , Dados de Sequência Molecular , Especificidade de Órgãos , Reação em Cadeia da Polimerase , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Mapeamento por Restrição , Suínos
17.
Insect Biochem Mol Biol ; 26(8-9): 837-43, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9014330

RESUMO

Levels of mRNA for the two 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthases, (HMG-S1 and HMG-S2), and for HMG-CoA reductase (HMG-R) of Blattella germanica were analyzed in the fat body during the first gonadotrophic cycle. HMG-S2 and HMG-R showed the highest mRNA levels on day 0 and decreased thereafter, whereas HMG-S1, showed faint expression. Western blot using specific antibodies for HMG-S1 and HMG-S2 showed no detectable levels for HMG-S1 but a clear pattern for HMG-S2. Both results point to a very limited role for HMG-CoA synthase-1 in B. germanica fat body that the functional enzyme in this organ is HMG-CoA synthase-2. HMG-CoA reductase and synthase proteins shared a cyclic pattern (maximum levels at day 4 and minimum levels on days 0 and 8), which was coincident with the pattern of activity. The delay between gene transcription and protein synthesis suggests a finely regulated translation mechanism. Moreover, the pattern of mevalonate synthesis parallels that of vitellogenin production, suggesting a coordinate mechanism between the mevalonate pathway and the production of vitellogenin.


Assuntos
Baratas/enzimologia , Hidroximetilglutaril-CoA Redutases/metabolismo , Hidroximetilglutaril-CoA Sintase/metabolismo , Vitelogênese/fisiologia , Sequência de Aminoácidos , Animais , Anticorpos , Corpo Adiposo/enzimologia , Feminino , Hidroximetilglutaril-CoA Redutases/genética , Hidroximetilglutaril-CoA Sintase/genética , Hidroximetilglutaril-CoA-Redutases NADP-Dependentes , Dados de Sequência Molecular , RNA Mensageiro , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
18.
J Biol Chem ; 267(30): 21873-8, 1992 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-1400496

RESUMO

Comparison of the farnesyl diphosphate (FPP) synthase amino acid sequences from four species with amino acid sequences from the related enzymes hexaprenyl diphosphate synthase and geranylgeranyl diphosphate synthase show the presence of two aspartate rich highly conserved domains. The aspartate motif ((I, L, or V)XDDXXD) of the second of those domains has homology with at least 9 prenyl transfer enzymes that utilize an allylic prenyl diphosphate as one substrate. In order to investigate the role of this second aspartate-rich domain in rat FPP synthase, we mutated the first or third aspartate to glutamate, expressed the wild-type and mutant enzymes in Escherichia coli, and purified them to apparent homogeneity using a single chromatographic step. Approximately 12 mg of homogeneous protein was isolated from 120 mg of crude bacterial extract. The kinetic parameters of the purified wild-type recombinant FPP synthase containing the DDYLD motif were as follows: Vmax = 0.84 mumol/min/mg; GPP Km = 1.0 microM; isopentenyl diphosphate (IPP) Km = 2.7 microM. Substitution of glutamate for the first aspartate (EDYLD) decreased the Vmax by over 90-fold. The Km for IPP increased, whereas the Km for GPP remained the same in this D243E mutant. Substitution of glutamate for the third aspartate (DDYLE) did not result in altered enzyme kinetics in the D247E mutant. These results suggest that the first aspartate in the second domain is involved in the catalysis by FPP synthase.


Assuntos
Alquil e Aril Transferases , Ácido Aspártico/metabolismo , Transferases/metabolismo , Sequência de Aminoácidos , Animais , Ácido Aspártico/genética , Sequência de Bases , Clonagem Molecular , DNA , Eletroforese em Gel de Poliacrilamida , Escherichia coli , Geraniltranstransferase , Cinética , Fígado/enzimologia , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Ratos , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Transferases/genética , Transferases/isolamento & purificação
20.
Plant Mol Biol ; 17(3): 517-22, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1884004

RESUMO

We report the characterization of a 1388 bp genomic fragment from Arabidopsis thaliana that encompasses the entire transcription unit of the gene encoding the precursor of 10 kDa polypeptide of photosystem II, 495 bp of the 5' flanking region and 73 bp of the 3' boundary of the gene. The deduced protein shows 78% and 73% homology, respectively, with its homologues from potato and spinach. The transcription of the gene seems to be greatly enhanced by light and only transcribed in substantial amounts in leaves and stems. Analysis of the putative 5' regulatory region of the gene shows homology with several cis-elements involved in light regulation of the transcription.


Assuntos
Complexo de Proteínas do Centro de Reação Fotossintética/genética , Sequência de Aminoácidos , Sequência de Bases , DNA , Luz , Dados de Sequência Molecular , Complexo de Proteínas do Centro de Reação Fotossintética/biossíntese , Complexo de Proteína do Fotossistema II , Plantas/genética , Precursores de Proteínas/genética , Mapeamento por Restrição
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