Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/epidemiología , Atención a la Salud/normas , Transmisión de Enfermedad Infecciosa/prevención & control , Pandemias , Neumonía Viral/epidemiología , Procedimientos Quirúrgicos Operativos/normas , COVID-19 , Infecciones por Coronavirus/transmisión , Humanos , Neumonía Viral/transmisión , SARS-CoV-2RESUMEN
Advantages of neoadjuvant chemoradiotherapy for locally advanced carcinoma of the middle and the lower third of the rectum are downstaging and downsizing of the tumor. Results of pathologic results are affected by post-treatment tissue changes and may influence the choice of surgical procedure. Forty-three consecutive patients (27 male, 16 female; mean age 64 years) were operated after receiving a long-term chemoradiotherapy during a period of 16 months. The data of initial staging procedure (high resolution magnetic resonance imaging) and results of pathological examination of the surgical specimens were analyzed. Regression of tumor was assessed by the absence of vital tumor cells and the post-treatment fibrotic tissue alterations. Regression of tumor size was seen in 42/43 patients leading to an improved T-stage in 27 patients. R0-resection was possible in all cases, although there was a perirectal tumor infiltration to less than 2 mm to circumference of the surgical specimen in 2 cases and unexpected small liver metastasis in 5 cases. Complete remission rate was 23.3% (10 cases). Detecting small amounts of vital tumor cells in altered tissue after chemoradiotherapy is a major problem of pathological examination procedure and should be taken into consideration by the surgeons. The choice of operation (resection vs. abdominoperineal extirpation vs. local excision) should be committed to the initial imaging procedure and not to any restaging procedure after neoadjuvant chemoradiotherapy.
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Adenocarcinoma/patología , Adenocarcinoma/terapia , Neoplasias del Recto/patología , Neoplasias del Recto/terapia , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/radioterapia , Terapia Combinada , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Cuidados Preoperatorios , Neoplasias del Recto/tratamiento farmacológico , Neoplasias del Recto/radioterapia , Inducción de Remisión , Factores de TiempoRESUMEN
Cholangiocarcinoma (CC) is the second most common type of primary liver cancer after hepatocellular carcinoma. Surgical resection is considered the only curative treatment for CC. In general, laparoscopic liver surgery (LLS) is associated with improved short-term outcomes without compromising the long-term oncological outcome. However, the role of LLS in the treatment of CC is not yet well established. In addition, CC may arise in any tract of the biliary tree, thus requiring different types of treatment, including pancreatectomies and extrahepatic bile duct resections. This review presents and discusses the state of the art in the laparoscopic and robotic surgical treatment of all types of CC. An electronic search was performed to identify all studies dealing with laparoscopic or robotic surgery and cholangiocarcinoma. Laparoscopic resection in patients with intrahepatic CC (ICC) is feasible and safe. Regarding oncologic adequacy, as R0 resections, depth of margins, and long-term overall and disease-free survival, laparoscopy is comparable to open procedures for ICC. An adequate patient selection is required to obtain optimal results. Use of laparoscopy in perihilar CC (PHC) has not gained popularity. Further studies are still needed to confirm the benefit of this approach over conventional surgery for PHC. Laparoscopic pancreaticoduodenectomy for distal CC (DCC) represents one of the most advanced abdominal operations owing to the necessity of a complex dissection and reconstruction and has also had small widespread so far. Minimally invasive surgery seems feasible and safe especially for ICC. Laparoscopy for PHC is technically challenging notably for the caudate lobectomy. Not least as for the LLR, the robotic approach for DCC appears technically achievable in selected patients.
Asunto(s)
Neoplasias de los Conductos Biliares/cirugía , Conductos Biliares Intrahepáticos , Colangiocarcinoma/cirugía , Laparoscopía , Supervivencia sin Enfermedad , Hepatectomía/métodos , Humanos , Laparoscopía/efectos adversos , Márgenes de Escisión , Neoplasia Residual , Pancreaticoduodenectomía/métodos , Procedimientos Quirúrgicos Robotizados/efectos adversos , Tasa de SupervivenciaRESUMEN
BACKGROUND: Clinical practice requires an accurate psychological assessment of subjects with clinical history of alcohol abuse and/or substance abuse (abuse history [AH]) for therapeutic choice. This study aims to identify significant correlations between the Minnesota Multiphasic Personality Inventory (MMPI)-2 scales in patients awaiting liver transplantation. METHODS: We evaluated a personality questionnaire containing MMPI-2 scales in the sample of 308 patients (81.8% males and 18.2% females) awaiting liver transplantation. The AH group composed 44.49% of patients and in the abuse free (AF) group, 55.51%. Scales were compared using Shapiro-Wilk test and Mann-Whitney U test. Interrelationships were examined using Spearman's correlation. RESULTS: This analysis found 27 scales of the MMPI-2 that were statistically different between 2 groups (AF and AH). In the AH group, we found a significant correlation between the following pairs of scales: Schizophrenia Scale (Sc) with the Addictions Potential Scale, Social Introversion scale (Si) with the Psychopathic Deviate scale (Pd), and Social Discomfort scale with Pd; the ES scale was negatively correlated with the Sc and Si scales. This interim study showed that the understanding of these indicators is crucial both for the assessment accuracy and for a prediction of the degree of therapy compliance after the transplantation. CONCLUSIONS: The scales of the MMPI-2 indicated a marked tendency to emotional rigidity, a lack of self-esteem and susceptibility judgment. Social introversion and social discomfort trends lead to impulsive behavior and deviant actions that combine poorly with good compliance with treatment.
Asunto(s)
Alcoholismo/psicología , Trasplante de Hígado , Cooperación del Paciente/psicología , Personalidad , Alcoholismo/terapia , Femenino , Humanos , MMPI , Masculino , Persona de Mediana Edad , Trastornos Relacionados con Sustancias/psicología , Trastornos Relacionados con Sustancias/terapia , Encuestas y Cuestionarios , Listas de EsperaRESUMEN
Nitric oxide (NO) releasing drugs (e.g., glyceryl trinitrate) were successfully used in the treatment of cutaneous leishmaniasis in man. In the present study, the effect of NO donors on the catalytic activity of the cysteine proteinase from promastigotes of Leishmania infantum, an agent of Old World visceral and cutaneous leishmaniases, is reported. In particular, one equivalent of NO, released by the NO donors S-nitrosoglutathione, glyceryl trinitrate, (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide, 3-morpholinosydnonimine, S-nitrosoacetylpenicillamine and sodium nitroprusside, inhibited one equivalent of the parasite cysteine proteinase. As expected, NO-deprived compounds did not affect the catalytic activity of the parasite cysteine proteinase. Furthermore, the absorption spectrum of the (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide-treated inactive L. infantum enzyme displayed a maximum in the 330-350 nm wavelength range. The reducing agents dithiothreitol and L-ascorbic acid completely prevented parasite cysteine proteinase inhibition by NO, fully restored the catalytic activity, and reversed the NO-induced absorption spectrum of the inactive enzyme. Moreover, S-nitrosoacetylpenicillamine displayed a leishmanicidal effect, inhibiting the cysteine proteinase activity in vivo. As expected, the NO-deprived compound N-acetylpenicillamine did not affect significantly the parasite viability and the enzyme activity in vivo. These data suggest that the L. infantum cysteine proteinase undergoes NO-mediated S-nitrosylation, thereby representing a possible mechanism of antiparasitic host defence.
Asunto(s)
Cisteína Endopeptidasas/metabolismo , Inhibidores de Cisteína Proteinasa/farmacología , Glutatión/análogos & derivados , Leishmania infantum/efectos de los fármacos , Donantes de Óxido Nítrico/farmacología , Óxido Nítrico/fisiología , Penicilamina/análogos & derivados , Proteínas Protozoarias/antagonistas & inhibidores , Animales , Ácido Ascórbico/farmacología , Ditiotreitol/farmacología , Glutatión/farmacología , Cinética , Leupeptinas/farmacología , Molsidomina/análogos & derivados , Molsidomina/farmacología , Nitrocompuestos/farmacología , Nitroglicerina/farmacología , Nitroprusiato/farmacología , Compuestos Nitrosos/farmacología , Penicilamina/farmacología , S-NitrosoglutatiónRESUMEN
In the body, nitric oxide (NO) is an important physiological regulator of functions such as vasodilatation and neurotransmission. Under pathological conditions, high concentrations of NO can be either beneficial(e.g. anti-bacterial, anti-parasitic and anti-viral) or detrimental; NO can therefore be considered a double-edged sword. When manipulating NO levels clinically, attention should be paid to minimize the negative effects and maximize the beneficial effects of NO. This article highlights recent evidence that supports the complexity of the regulatory mechanisms that lead to sophisticated endogenous NO production.
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Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico/metabolismo , Animales , Humanos , Óxido Nítrico/uso terapéutico , Óxido Nítrico Sintasa de Tipo I , Óxido Nítrico Sintasa de Tipo II , Óxido Nítrico Sintasa de Tipo IIIRESUMEN
Cysteine proteases represent a broad class of proteolytic enzymes widely distributed among living organisms. Although well known as typical lysosomal enzymes, cysteine proteases are actually recognized as multi-function enzymes, being involved in antigen processing and presentation, in membrane-bound protein cleavage, as well as in degradation of the cellular matrix and in processes of tissue remodeling. Very recently, it has been shown that the NO(-donor)-mediated chemical modification of the Cys catalytic residue of cysteine proteases, including Coxsackievirus and Rhinovirus cysteine proteases, cruzain, Leishmania infantum cysteine protease, falcipain, papain, as well as mammalian caspases, cathepsins and calpain, blocks the enzyme activity in vitro and in vivo. Here, inhibition of representative cysteine proteases by NO(-donors) is reviewed.
Asunto(s)
Inhibidores de Cisteína Proteinasa/farmacología , Donantes de Óxido Nítrico/farmacología , Animales , Calpaína/química , Calpaína/efectos de los fármacos , Caspasas/química , Caspasas/efectos de los fármacos , Dominio Catalítico , Catepsinas/química , Catepsinas/efectos de los fármacos , Cisteína Endopeptidasas/química , Cisteína Endopeptidasas/efectos de los fármacos , Humanos , Técnicas In Vitro , Mamíferos , Modelos Químicos , Modelos Moleculares , Papaína/química , Papaína/efectos de los fármacos , Parásitos/enzimología , Plantas/enzimología , Proteínas Protozoarias/química , Proteínas Protozoarias/efectos de los fármacos , Virus/enzimologíaRESUMEN
Nitric oxide (NO) is considered an important signaling molecule implied in different physiological processes, including nervous transmission, vascular regulation, immune defense, and in the pathogenesis of several diseases. The presence of NO is well demonstrated in all vertebrates. The recent data on the presence and roles of NO in the main invertebrate groups are reviewed here, showing the widespread diffusion of this signaling molecule throughout the animal kingdom, from higher invertebrates down to coelenterates and even to prokaryotic cells. In invertebrates, the main functional roles described for mammals have been demonstrated, whereas experimental evidence suggests the presence of new NOS isoforms different from those known for higher organisms. Noteworthy is the early appearance of NO throughout evolution and striking is the role played by the nitrergic pathway in the sensorial functions, from coelenterates up to mammals, mainly in olfactory-like systems. All literature data here reported suggest that future research on the biological roles of early signaling molecules in lower living forms could be important for the understanding of the nervous-system evolution.
Asunto(s)
Invertebrados/fisiología , Fenómenos Fisiológicos del Sistema Nervioso , Óxido Nítrico/fisiología , Animales , Evolución Biológica , Óxido Nítrico Sintasa/metabolismo , Transducción de SeñalRESUMEN
An established human astrocytoma cell line (T67) was shown to constitutively produce the proteinase inhibitor alpha 2 macroglobulin (alpha 2M). Interferon gamma (IFN gamma), a potent immunoregulatory lymphokine, was able to increase the synthesis of alpha 2M by these cells, as measured by ELISA on cell supernatants. The alpha 2M induction was also observed in other human glioma cell lines (T70 and ADF) and in human fetal astrocyte cultures following IFN gamma treatment. In T67 cells this effect was dose-dependent and the maximum (2.7-fold increase) was obtained with 2000 U/ml of IFN gamma. A corresponding enhanced alpha 2M mRNA accumulation was demonstrated by PCR and Northern blot techniques. Our results suggest an important role of alpha 2M during inflammatory and immune processes in the CNS. An increased release of alpha 2M following IFN gamma stimulation may allow the removal of the bulk of proteases released at the site of inflammation, strengthening at the same time the antigen presentation processes.
Asunto(s)
Astrocitoma/metabolismo , Interferón gamma/farmacología , alfa-Macroglobulinas/biosíntesis , Secuencia de Bases , Humanos , Datos de Secuencia Molecular , ARN Mensajero/análisis , Células Tumorales Cultivadas , Regulación hacia Arriba , alfa-Macroglobulinas/genéticaRESUMEN
1. The role of the L-arginine-nitric oxide (NO) pathway on the formation of prostaglandin E2 (PGE2) by human cultured astroglial cells incubated with interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha) was investigated. 2. Incubation of T 67 astroglial cell line with IL-beta (10 ng ml(-1)) and TNF-alpha (500 u ml(-1)) produced a significant (P<0.05) increase of both nitrite (the breakdown product of NO), cyclic GMP and PGE2 levels in cell supernatants. N omega-nitro-L-arginine methyl ester (L-NAME; 20-300 microM), an inhibitor of NO synthase (NOS), inhibited the increase of cyclic GMP and nitrite levels found in supernatants of cytokine-treated astroglial cells and reduced the release of PGE2. The latter effect showed that the enhanced arachidonic acid (AA) metabolism subsequent to stimulation of astroglial cells with IL-1beta and TNF-alpha was, at least in part, induced by NO. This occurred also when sodium nitroprusside (SNP; 120 microM), an NO donor, was incubated with astroglial cells, an effect antagonized by oxyhaemoglobin (OxyHb; 10 microM). 3. The inhibition elicited by L-NAME on PGE2-release by cytokine-treated astroglial cells was reversed by adding AA (40 microM), showing that the effect of NO on cytokine-dependent PGE2 release occurred at the cyclo-oxygenase (COX) level. Furthermore, the release of PGE2 in cytokine-treated astroglial cells was inhibited by indomethacin (10 microM), a COX inhibitor as well as by preincubating cells with dexamethasone (20 microM), an inhibitor of inducible enzymes, showing that the inducible isoform of COX (COX-2) was involved. 4. On the other hand, pretreating astroglial cells with methylene blue (MB; 10 microM), an inhibitor of NO biological activity acting at the guanylate cyclase level, failed to affect PGE2 release in cytokine-treated astroglial cells, leading to the conclusion that cyclic GMP changes related to NO formation are not involved in the generation of AA metabolites. 5. The present experiments demonstrated that the release of PGE2 by astroglial cells pretreated with IL-1beta and TNF-alpha is due to enhanced COX-2 activity via activation of the L-arginine-NO pathway, and this may be relevant to the understanding of the pathophysiological mechanisms underlying neuroimmune disorders.
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Astrocitos/metabolismo , Dinoprostona/metabolismo , Interleucina-1/metabolismo , Isoenzimas/biosíntesis , Óxido Nítrico/metabolismo , Prostaglandina-Endoperóxido Sintasas/biosíntesis , Factor de Necrosis Tumoral alfa/metabolismo , Astrocitos/citología , Astrocitos/efectos de los fármacos , Astrocitos/enzimología , Línea Celular , GMP Cíclico/metabolismo , Ciclooxigenasa 2 , Inhibidores de la Ciclooxigenasa 2 , Inhibidores de la Ciclooxigenasa/farmacología , Dexametasona/farmacología , Inducción Enzimática , Inhibidores Enzimáticos/farmacología , Humanos , Proteínas de la Membrana , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Nitritos/metabolismo , Nitroprusiato/farmacologíaRESUMEN
Clonidine, clinically used in the treatment of hypertension, is a central alpha(2)-adrenergic agonist that reduces blood pressure and slows heart rate by reducing sympathetic stimulation. Considering the structural similarity between clonidine and hydrophobic heterocyclic nitric oxide synthase (NOS) inhibitors, the effect of clonidine on the nitric oxide (NO) pathway was investigated. This was verified by determination of NOS activity in vitro and by analysis of inducible Ca(2+)-independent NOS (NOS-II) mRNA expression and measurement of nitrite levels in rat C6 glioma cells, taken as a cellular model. Clonidine inactivated neuronal Ca(2+)-dependent NOS (NOS-I) competitively without affecting NOS-II and endothelial Ca(2+)-dependent NOS (NOS-III) activity. However, the value of K(i) for clonidine binding to NOS-I depended on tetrahydrobiopterin (BH(4)) concentration, as reported for NOS inhibition by other nitrogen heterocyclic compounds. In particular, the value of K(i) for clonidine binding to NOS-I increased (from [7. 9 +/- 0.4] x 10(-5) M to [8.0 +/- 0.4] x 10(-3) M) as BH(4) concentration was increased (between 3.0 x 10(-7) M and 1.0 x 10(-3) M), at pH 7.5 and 37.0 degrees. In addition, clonidine (1.0 x 10(-4) M) enhanced NOS-II mRNA expression in rat C6 glioma cells, as induced by Escherichia coli lipopolysaccharide (LPS) plus interferon-gamma (IFN-gamma). Finally, clonidine (1.0 x 10(-4) M to 1.0 x 10(-3) M) dose dependently increased the levels of LPS/IFN-gamma-induced nitrites, the breakdown product of NO, in supernatants of rat C6 glioma cells. As reported for other NOS inhibitors, clonidine was also able to regulate NOS-I and NOS-II inversely.
Asunto(s)
Antihipertensivos/farmacología , Clonidina/farmacología , Inhibidores Enzimáticos/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Óxido Nítrico/metabolismo , Animales , Glioma/enzimología , Glioma/patología , Óxido Nítrico Sintasa/genética , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico Sintasa de Tipo I , Óxido Nítrico Sintasa de Tipo II , Nitritos/metabolismo , ARN Mensajero/metabolismo , Ratas , Células Tumorales CultivadasRESUMEN
The aim of this study was to investigate the role of NO-cGMP pathway in NMDA-induced NGF mRNA expression by T67 astrocytoma cells. Levels of nitrite, a breakdown product of NO, in supernatants of NMDA-treated astrocytoma cells were significantly higher compared with control cells, this effect being reversed by the specific NO synthase inhibitor L-NAME. Furthermore, NGF mRNA expression was induced by NMDA treatment, this effect being inhibited by pretreating cells with L-NAME. Moreover, methylene blue, an inhibitor of NO biological activity at guanylate cyclase level, inhibited NMDA-induced NGF mRNA expression and this effect was reversed by dbt2-cGMP. These findings suggest that NO-cGMP pathway mediates the synthesis of NGF mRNA.
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Astrocitoma/metabolismo , N-Metilaspartato/fisiología , Factores de Crecimiento Nervioso/genética , Óxido Nítrico/fisiología , ARN Mensajero/metabolismo , Astrocitoma/patología , Secuencia de Bases , Southern Blotting , Humanos , Sondas Moleculares/genética , Datos de Secuencia Molecular , Nitritos/metabolismo , Reacción en Cadena de la Polimerasa , Células Tumorales CultivadasRESUMEN
In recent literature, lymphokines have been reported to be able to promote both proliferation and maturation of some glial populations. In this paper, we compare the effect of rIL-1 on newborn and adult rat astroglial cells in vitro. In newborn, but not in adult astrocytes, 100 U/ml of rIL-1 beta increase [3H]thymidine incorporation with a maximal response by 3 days as compared to the control untreated culture. In contrast, rIL-1 beta induces an increase of GFAP immunoreactivity both in newborn and in adult astrocytes, as compared to the control untreated cells. These data indicate that, while both newborn and adult astroglial cells are capable of responding to rIL-1 beta, only newborn astrocytes can respond to this lymphokine with proliferation. Thus, it appears likely that different factors, other than rIL-1 beta, are needed by adult astrocytes to proliferate.
Asunto(s)
Envejecimiento/fisiología , Animales Recién Nacidos/fisiología , Astrocitos/efectos de los fármacos , Interleucina-1/farmacología , Animales , División Celular/efectos de los fármacos , Proteína Ácida Fibrilar de la Glía/biosíntesis , Inmunohistoquímica , Técnicas In Vitro , Ratas , Proteínas Recombinantes/farmacologíaRESUMEN
The present study demonstrates that a NADPH/Ca2+-dependent nitric oxide synthase (NOS) activity is present in the soluble and in the particulate fractions of fish caudal spinal cord homogenates, both activities being inhibited by calmodulin inhibitors (W7 and/or TFP) and by the NOS inhibitor L-NAME. Moreover, Western blot analysis using either anti-NOS I or anti-NOS III antibodies shows that the soluble enzyme corresponds to the brain NOS (NOS-I) of mammals, whereas the particulate one is likely attributable to NOS I and/or NOS III (ecNOS) enzymes. To confirm the nitric oxide (NO) production by the caudal spinal cord homogenates, the NO-mediated conversion of oxyhemoglobin to methemoglobin was monitored spectroscopically. The present results are consistent with a constitutive, Ca2+-calmodulin-dependent, NO production by the caudal neurosecretory system.
Asunto(s)
Óxido Nítrico Sintasa/metabolismo , Médula Espinal/enzimología , Animales , Arginina/metabolismo , Encéfalo/enzimología , Calmodulina/antagonistas & inhibidores , Cinética , NADP/metabolismo , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico Sintasa de Tipo I , Óxido Nítrico Sintasa de Tipo III , Sulfonamidas/farmacología , Tilapia , Trifluoperazina/farmacologíaRESUMEN
This study provides evidence that, within the caudal neurosecretory system of the teleost Oreochromis niloticus, neurons express nitric oxide synthase (NOS)-like molecules. The presence of NOS-like molecules was demonstrated by means of NADPH-diaphorase (NADPHd) staining and NOS immunohistochemistry. In the caudal spinal cord, NOS-positive neurosecretory cell bodies and neurosecretory fibers were observed. In addition, NOS-positive structures were found in the urophysis which correspond to neurosecretory axon terminals. Cellular co-localization of NOS and ovine corticotropin-releasing factor (oCRF) immunoreactivities confirmed that the NOS-positive structures belong to the caudal neurosecretory system. The present results suggest that NO may participate in the caudal neuroendocrine function.
Asunto(s)
Óxido Nítrico Sintasa/metabolismo , Médula Espinal/enzimología , Tilapia/fisiología , Animales , Hormona Liberadora de Corticotropina/análisis , Técnica del Anticuerpo Fluorescente Indirecta , Inmunohistoquímica , NADPH Deshidrogenasa/metabolismo , Neuroglía/enzimología , Terminales Presinápticos/enzimología , Médula Espinal/químicaRESUMEN
The effect of basic fibroblast growth factor (bFGF) on inducible nitric oxide synthase (iNOS) mRNA expression in human cultured ramified microglial cells was investigated. Using RT-PCR and Southern blot analysis, we found that bFGF prevented the iNOS gene expression as induced by LPS/TNF alpha. Also, bFGF dose-dependently inhibited nitrite levels in treated cell supernatants. That the early presence of bFGF during LPS/TNF alpha induction was essential indicates that iNOS gene expression can be transcriptionally regulated.
Asunto(s)
Factor 2 de Crecimiento de Fibroblastos/farmacología , Microglía/metabolismo , Óxido Nítrico Sintasa/antagonistas & inhibidores , ARN Mensajero/biosíntesis , Southern Blotting , Células Cultivadas , Inducción Enzimática/efectos de los fármacos , Humanos , Microglía/efectos de los fármacos , Óxido Nítrico Sintasa/biosíntesis , Reacción en Cadena de la PolimerasaRESUMEN
This study shows that human ramified microglial cells derived from fetal brain primary cultures, are able to produce nitric oxide (NO). In fact, stimulation with Escherichia coli lipopolysaccharide (LPS) (1 microgram ml-1) or tumor necrosis factor alpha (TNF alpha) (500 U ml-1) enhances nitrite release in cell supernatants, as determined by the Griess reaction. A synergistic effect is achieved following treatment with LPS plus TNF alpha, this effect being inhibited by pretreating cells with NOS inhibitor N omega-nitro-L-arginine methyl ester (L-NAME). Using reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis, we also found that LPS/TNF alpha produce an increase of inducible NO synthase (iNOS) mRNA expression.
Asunto(s)
Escherichia coli , Lipopolisacáridos/farmacología , Microglía/enzimología , Óxido Nítrico/biosíntesis , Factor de Necrosis Tumoral alfa/farmacología , Secuencia de Bases , Células Cultivadas/efectos de los fármacos , Células Cultivadas/metabolismo , Escherichia coli/química , Regulación Enzimológica de la Expresión Génica/fisiología , Humanos , Microglía/efectos de los fármacos , Datos de Secuencia Molecular , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa/efectos de los fármacos , Óxido Nítrico Sintasa/genética , Reacción en Cadena de la Polimerasa , ARN Mensajero/análisisRESUMEN
Nitric oxide (NO) has been reported to regulate NF-kappaB, one of the best-characterized transcription factors playing important roles in many cellular responses to a large variety of stimuli. NO has been suggested to induce or inhibit the activation of NF-kappaB, its effect depending, among others, on the cell type considered. In this review, the inhibitory effect of NO on NF-kappaB (and subsequent suppression of NF-kappaB-dependent gene expression) in glial cells is reported. In particular, exogenous and endogenous NO has been observed to keep NF-kappaB suppressed, thus preventing the expression of NF-kappaB-induced genes, such as inducible NO synthase itself or HIV-1 long terminal repeat. Furthermore, the possible molecular mechanisms of NO-mediated NF-kappaB inhibition are discussed. More specifically, NO has been reported to suppress NF-kappaB activation inducing and stabilizing the NF-kappaB inhibitor, IkappaB-alpha. On the other hand, NO may inhibit NF-kappaB DNA binding through S-nitrosylation of cysteine residue (i. e., Cys62) of the p50 subunit. As a whole, a novel concept that the balance of intracellular NO levels may control the induction of NF-kappaB in glial cells has been hypothesized.
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FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , Neuroglía/metabolismo , Óxido Nítrico/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Factores de Transcripción/metabolismo , Animales , Humanos , FN-kappa B/genética , Factor de Transcripción ReIBRESUMEN
In infected human cells, nitric oxide (NO) has been shown to inhibit the replication of the human immunodeficiency virus-1 (HIV-1), the etiological agent of AIDS. Evidence suggests that NO may regulate HIV-1 replication by affecting the sulphydryl redox state. In this respect, it has been very recently demonstrated that NO-donors inactivate the HIV-1-encoded protease and reverse transcriptase in vitro. Further viral and host NO targets may be envisaged. Although no data are available on the anti-HIV-1 effect of NO in vivo, NO-releasing drugs, clinically used in the treatment of cardiovascular disorders, may represent a novel class of molecules for decreasing virus replication. Here, the possible molecular bases for the anti-HIV-1 effect of NO are discussed.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/virología , VIH-1/fisiología , Óxido Nítrico/fisiología , Replicación Viral/fisiología , Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Integrasa de VIH/química , Integrasa de VIH/fisiología , Proteasa del VIH/química , Proteasa del VIH/fisiología , Transcriptasa Inversa del VIH/química , Transcriptasa Inversa del VIH/fisiología , VIH-1/química , VIH-1/efectos de los fármacos , Humanos , Óxido Nítrico/química , Donantes de Óxido Nítrico/farmacología , Donantes de Óxido Nítrico/uso terapéutico , Replicación Viral/efectos de los fármacosRESUMEN
Gabexate mesylate (GM; commercialized under the brand name FOY) is a nonantigenic synthetic inhibitor of plasmatic and pancreatic serine proteinases that is used therapeutically in the treatment of pancreatitis and disseminated intravascular coagulation and as a regional anticoagulant for hemodialysis. The inhibitory effect of GM on nitric oxide synthase as well as serine proteinases and swine kidney copper amine oxidase, all acting on cationic substrates, has been investigated. On the basis of the available X-ray crystal structures of the enzymes considered, the possible binding mode(s) of GM has(have) been analyzed. The enzyme cross-inhibition by GM suggests that the use of this drug should be under careful control. With the aim to improve the scarce plasma stability of GM, the positively charged drug has been complexed to the surface of preformed anionic liposomes. The liposome-complexed GM half-life increases about five-fold, indicating the protective effect of liposomes on GM degradation. Moreover, the GM complexation with liposomes does not alter its inhibitory activity on NOS-I and porcine pancreatic trypsin.