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2.
Rev Esp Enferm Dig ; 101(11): 787-99, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20001156

RESUMO

Both the prognosis and potential treatment of chronic liver disease greatly depend on the progression of liver fibrosis, which is the ultimate outcome of chronic liver damage. Historically, liver biopsy has been instrumental in adequately assessing patients with chronic liver disease. Histological assessment allows clinicians both to obtain diagnostic information and initiate adequate therapy. However, the technique is not exempt of deleterious effects. Multiple diagnostic tests have been developed for the staging of fibrosis using noninvasive methods, most of them in the setting of chronic hepatitis C. The goal of this paper is to review available data on the staging and assessment of liver fibrosis with two methods: serum markers and transient elastography (FibroScan).


Assuntos
Técnicas de Imagem por Elasticidade , Cirrose Hepática/sangue , Cirrose Hepática/diagnóstico , Biomarcadores/sangue , Humanos
3.
Rev Esp Enferm Dig ; 101(6): 413-23, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19630465

RESUMO

Primary biliary cirrhosis (PBC) would develop when the immune system comes across a microorganism with proteins similar to those in the piruvate dehydrogenase complex E2 (PDC-E2), or a neoantigen resulting from a xenobiotic-modified autoantigen. This would lead to an innate immune response where TLRs would play a pivotal mediating role, which would give rise to a local microenvironment favoring an adaptive immune response. Such response would be particularly strong in individuals with selected genetic characteristics. The genetic characteristics underlying this predisposition remain unknown, but they likely entail small numbers of scarcely-active regulatory T cells. The AE2 anion exchanger, which is deficient in patients with PBC, may reduce the number and activity of regulatory T cells. NK cells are also pivotal in the preparation of an adaptive response, as they release a number of cytokines and chemokines that favor and recruit antigen-presenting cells to activate B and T cells - CD4+ Th1 and CD8+. An activation of the former would increase the production of IgM and anti-mitochondrial IgG and IgA antibodies against PDC-E2. An activation of CD8+ cells, also sensitive to PDC-2 as aberrantly expressed on the surface of BECs and SECs, would result in apoptosis for these epithelial cells, and in small bile-duct destruction. Immune response is likely inadequately suppressed because of the small numbers of scarcely-active regulatory T cells, the latter resulting from low genetic expression and activity of the AE2 transporter.


Assuntos
Cirrose Hepática Biliar/etiologia , Formação de Anticorpos , Meio Ambiente , Humanos , Imunidade Celular , Imunidade Inata , Cirrose Hepática Biliar/imunologia
4.
Rev Esp Enferm Dig ; 101(5): 336-42, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19527079

RESUMO

Chronic intestinal pseudoobstruction (CIPO) is a rare entity characterized by recurrent clinical episodes of intestinal obstruction in which no mechanical cause is identified. There are multiple causes for this syndrome but two main groups can be distinguished: a) secondary to a systemic non-gastrointestinal disease; and b) primary or idiopathic originated from alterations in the components of the intestinal wall. The latter forms are the most uncommon and their diagnosis is generally difficult. In the present article, we describe nine patients with CIPO that were diagnosed in our center over the last six years. Four of them were diagnosed with primary or idiopathic form of CIPO and another four were clearly secondary to a systemic disease. The ninth case, which was initially diagnosed as secondary, is probably also a primary form of the disease. The number of patients diagnosed in our center, even thought small, makes us to hypothesize that the prevalence of CIPO is probably greater than is generally believed and that the reasons of its rarity are the incomplete understanding of its physiopathology and the difficulties to achieve a correct diagnosis.


Assuntos
Pseudo-Obstrução Intestinal/diagnóstico , Músculo Liso/fisiopatologia , Doenças Neuromusculares/complicações , Actinas/deficiência , Adulto , Doença Crônica , Colectomia , Constipação Intestinal/etiologia , Feminino , Trânsito Gastrointestinal , Humanos , Ileostomia , Pseudo-Obstrução Intestinal/epidemiologia , Pseudo-Obstrução Intestinal/etiologia , Pseudo-Obstrução Intestinal/fisiopatologia , Pseudo-Obstrução Intestinal/cirurgia , Laparoscopia , Manometria , Pessoa de Meia-Idade , Doenças Musculares/complicações , Doenças Musculares/diagnóstico , Transtornos Puerperais/etiologia , Escleroderma Sistêmico/complicações
5.
Dig Liver Dis ; 40(3): 200-5, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18261709

RESUMO

BACKGROUND: Dyslipidaemia and insulin resistance are two important risk factors for non-alcoholic fatty liver disease. Both factors can improve with fenofibrate. AIMS: To evaluate the effect of fenofibrate on the clinical, analytical and histological evolution of patients with non-alcoholic fatty liver disease. SUBJECTS AND METHODS: Sixteen consecutive patients with biopsy-confirmed non-alcoholic fatty liver disease were treated with 200mg/day of fenofibrate for 48 weeks. A clinical and biochemical follow-up was done every 3 months. A new liver biopsy was performed in all patients at the end of therapy. RESULTS: All patients completed 48 weeks of therapy with fenofibrate, without adverse events. At the end of the study, a significant decrease in triglyceride, glucose, alkaline phosphatase and gamma-glutamyl transpeptidase and an increase of apolipoprotein A1 levels were found. Insulin levels and insulin resistance showed a trend to decrease. Moreover, a reduction in the proportion of patients with abnormal aminotransferase levels (>45IU/L) was observed (alanine aminotransferase: 93.7% vs. 62.5%, p=0.02; aspartate aminotransferase: 50% vs. 18.7%, p=0.02). The body mass index did not show any significant change, but the proportion of patients with metabolic syndrome decreased significantly (43.7% vs. 18.7%, p=0.04). A control biopsy after treatment revealed a decrease in the grade of hepatocellular ballooning degeneration (p=0.03), but the grade of steatosis, lobular inflammation, fibrosis or non-alcoholic fatty liver disease activity score did not change significantly. CONCLUSIONS: In patients with non-alcoholic fatty liver disease, treatment with fenofibrate is safe and improves metabolic syndrome, glucose and liver tests. However, its effects on liver histology are minimal.


Assuntos
Fígado Gorduroso/tratamento farmacológico , Fenofibrato/uso terapêutico , Hipolipemiantes/uso terapêutico , Adulto , Fosfatase Alcalina/sangue , Apolipoproteína A-I/sangue , Biópsia por Agulha , Relação Dose-Resposta a Droga , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Feminino , Seguimentos , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Projetos Piloto , Estudos Retrospectivos , Transaminases/sangue , Resultado do Tratamento , Triglicerídeos/sangue , gama-Glutamiltransferase/sangue
6.
Rev Esp Enferm Dig ; 100(1): 17-23, 2008 Jan.
Artigo em Espanhol | MEDLINE | ID: mdl-18358056

RESUMO

OBJECTIVES: To compare subjective tolerance and secondary adverse events to bowel cleansing prior to colonoscopy with polyethylene glycol (PEG) and sodium phosphate (NaP) in adult patients and in those 65 or more years old. MATERIAL AND METHODS: Retrospective matched study, choosing 140 patients among all of those who underwent colonoscopy from March 2004 to May 2005. We investigated the presence of the next adverse events during bowel preparation: Fever, low digestive bleeding, abdominal pain, perianal pain, nausea, vomiting, thirst, somnolence, agitation, tremor and convulsions. We considered bad objective tolerance if the patient presented any one of these events. We also asked patients about subjective tolerance to preparation. RESULTS: Seventy patients prepared with PEG and seventy with NaP were included (69 women and 71 men, mean age 60.6 +/- 14.8 years). There was no relationship between subjective tolerance or the presence of adverse events and bowel cleansing with any of the products in general population or in elderly patients (p = 0.09 and p = 0.45 in the elderly). However, patients prepared with NaP showed more nausea than those who employed PEG (p < 0.009), overall women of 65 or more years old. There were no severe adverse events in patients prepared with NaP. Elderly showed better tolerance than younger patients, and women worst tolerance than men, irrespective of the lavage preparation employed. Patients prepared with PEG unfinished bowel cleansing more frequently than those with NaP. Cleanliness achieved with NaP was significantly better than that obtained with PEG. CONCLUSIONS: Bowel cleansing prior to colonoscopy with NaP is as well tolerated, safe and effective as with PEG, even in elderly healthy patients, although it causes more nausea. Cleanliness with NaP is better than that achieved with PEG.


Assuntos
Colonoscopia , Fosfatos/efeitos adversos , Polietilenoglicóis/efeitos adversos , Cuidados Pré-Operatórios , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente/estatística & dados numéricos , Estudos Retrospectivos
7.
Rev Esp Enferm Dig ; 100(2): 104-7, 2008 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-18366271

RESUMO

INTRODUCTION: liver cirrhosis is the main cause of portal thrombosis (PT), while hypercoagulability syndromes are rarely found as the etiology of PT. We report a case of portal and mesenteric thrombosis secondary to protein S deficiency. CASE REPORT: a 74-year-old woman was admitted with melena secondary to upper gastrointestinal bleeding. She reported mild, diffuse abdominal pain in the last 2 weeks. Endoscopy revealed ruptured esophageal varices. Doppler ultrasonography and CT demonstrated a heterogeneous liver, splenomegaly and ascites, and complete non-occlusive PT involving the hilum and portal branches, as well as the superior mesenteric vein, with portosystemic collaterals. At this point a complete study for cirrhosis etiologies was negative, including a liver biopsy that showed nonspecific architectural changes secondary to diminished blood flow, which suggested non-cirrhotic portal hypertension. The search for hypercoagulability states determined a deficiency of S protein, with total pS = 107% and free pS = 56%. The patient was started on anticoagulant treatment and no other thrombotic events occurred. DISCUSSION: PT usually manifests without specific symptoms. The most common presentation is upper gastrointestinal bleeding, as occurred in our patient. Liver cirrhosis is one of the most frequent cause of PT. Up to 65% of these patients present an associated prothrombotic state, including protein S deficiency. Our case reminds us of the importance of a systematic search for hipercoagulability syndromes in patients with TP, even when the etiology can be conferred to liver cirrhosis.


Assuntos
Oclusão Vascular Mesentérica/etiologia , Veia Porta , Deficiência de Proteína S/complicações , Trombose/etiologia , Idoso , Feminino , Humanos , Veias Mesentéricas
8.
Rev Esp Enferm Dig ; 99(2): 100-11, 2007 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-17417923

RESUMO

Chronic intestinal pseudo-obstruction (CIPO) is a syndrome characterized by the presence of recurrent episodes of clinical intestinal obstruction in the absence of obstructive lesions. Although this syndrome is rare, it causes a high morbidity. It is caused by a disturbance of the intestinal motility, that results in a failure of the progression of the intestinal content. Basically, the failure of the intestinal motility is a consequence of muscular disorder, neurological disorder or both. Usually, CIPO is secondary to other systemic disease; however, in the last years, many cases of primary CIPO have been described. The use of new manometric tecniques and specific histological procedures have allowed to clarify the pathogenesis of some of these entities including mitochondrial diseases and paraneoplasic syndromes. Clinical manifestations of CIPO are diverse, depending on the location and extension of the motility disorder. As the diagnosis of this disease is usually not an easy task, patients frecuently undergo unnecesary surgical interventions, are diagnosed of psyquiatric disorders, or the correct diagnosis is delayed several years after the first symptoms arise. The aims of the treatment are to maintain the nutritional condition and to improve symptoms using nutritional measures, drugs or, eventually, endoscopical or surgical procedures.


Assuntos
Pseudo-Obstrução Intestinal , Doença Crônica , Cisaprida/uso terapêutico , Suplementos Nutricionais , Endoscopia , Fármacos Gastrointestinais/uso terapêutico , Humanos , Pseudo-Obstrução Intestinal/classificação , Pseudo-Obstrução Intestinal/diagnóstico , Pseudo-Obstrução Intestinal/diagnóstico por imagem , Pseudo-Obstrução Intestinal/tratamento farmacológico , Pseudo-Obstrução Intestinal/etiologia , Pseudo-Obstrução Intestinal/cirurgia , Pseudo-Obstrução Intestinal/terapia , Estado Nutricional , Octreotida/uso terapêutico , Cuidados Paliativos , Prognóstico , Radiografia Abdominal , Tomografia Computadorizada por Raios X
9.
Rev Esp Enferm Dig ; 99(6): 337-42, 2007 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-17883297

RESUMO

OBJECTIVE: The aim of this study was to determine the prevalence of celiac disease among the adult population of Madrid by measuring antibodies against tissue transglutaminase as serologic screening method. POPULATION AND METHODS: 2,215 subjects participated voluntarily in this study. All of them completed a clinical questionnaire. We determined the levels of total IgA and antibodies to tissue transglutaminase (tTG). An intestinal biopsy by endoscopy was proposed to all subjects who were tTG-positive. The histologic lesion was classified in accordance to Marsh. RESULTS: Three known CD cases were identified by the questionnaire. Eleven donors with tTG positivity were detected, all of them asymptomatic. Four subjects rejected the intestinal biopsy. Seven out of 11 positive subjects consented to undergo a duodenal biopsy -3 had villous atrophy and 4 had increased intraepithelial lymphocyte counts with normal villi. In our study the number of donors with biopsy-proven CD was 6, and the prevalence was 1/370. If we include the subcategories of gluten sensitive enteropathy (Marsh I), the prevalence would be 1/222. When we considered antibody positivity the prevalence of gluten sensitivity was 1 in 201, and it reached 1 in 158 when the three known CD cases were included. CONCLUSIONS: Data on CD prevalence in this study confirm that CD is a first-line healthcare problem that may warrant universal screening. We detected a high number of lymphocytic enteritis cases, and thus some sort of action is mandatory.


Assuntos
Doadores de Sangue/estatística & dados numéricos , Doença Celíaca/epidemiologia , Adulto , Atrofia , Autoanticorpos/sangue , Autoanticorpos/imunologia , Doença Celíaca/sangue , Doença Celíaca/diagnóstico , Doença Celíaca/dietoterapia , Comorbidade , Diabetes Mellitus Tipo 1/epidemiologia , Duodeno/ultraestrutura , Feminino , Proteínas de Ligação ao GTP , Antígenos HLA/análise , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Masculino , Microvilosidades/ultraestrutura , Prevalência , Proteína 2 Glutamina gama-Glutamiltransferase , Espanha/epidemiologia , Tireoidite Autoimune/epidemiologia , Transglutaminases/imunologia
10.
Rev Esp Enferm Dig ; 98(4): 292-302, 2006 Apr.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-16792457

RESUMO

Chronic intestinal pseudo-obstruction is an uncommon syndrome characterized by relapsing episodes suggesting intestinal obstruction during which no mechanical causes are identified to account for symptoms. Etiologic factors may be manifold. Among them a number of neurologic conditions, gastrointestinal smooth muscle myopathies, endocrino-metabolic and autoimmune diseases, and the use of selected drugs stand out. We report a case of chronic intestinal pseudo-obstruction originating in a sporadic, primary intestinal myopathy that corresponds to no type thus far described. A histological study of the intestinal wall showed disrupted muscle bundles and the presence of interstitial edema. Myocytes had severe degenerative changes, and no alterations were seen in submucosal and myenteric plexus neurons. The activity of enzyme complexes in the mitochondrial respiratory chain, and of thymidine phosphorylase was normal. No mitochondrial DNA changes were seen.


Assuntos
Pseudo-Obstrução Intestinal/patologia , Adulto , Doença Crônica , Feminino , Humanos , Pseudo-Obstrução Intestinal/etiologia
11.
Rev Esp Enferm Dig ; 98(10): 723-39, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17094721

RESUMO

BACKGROUND: short-bowel transplantation has experienced a substantial growth worldwide following improved results from the late 1990's on, and its coverage by Medicare. According to the International Registry (1985-2005), a total of 1,292 intestinal transplants for 1,210 patients in 65 hospitals across 20 countries have been carried out thus far. OBJECTIVE: to know short-term (6 months) results regarding patient and graft survival from the first Spanish series of intestinal transplants in adult recipients. MATERIAL AND METHODS: we present our experience in the assessment of 20 potential candidates to short-bowel transplantation between June 2004 and October 2005. Of these, 10 patients were rejected and 4 were transplanted, which makes up the sample of our study. RESULTS: to this date 5 transplants have been carried out in 4 patients (2 retransplants, 2 desmoid tumors, 1 short bowel syndrome after excision as a result of mesenteric ischemia). Upon study completion and after a mean follow-up of 180 days (range 90-190 days) all recipients are alive, and all grafts but one (75%) are fully operational, with complete digestive autonomy. All patients received induction with alemtuzumab except one, who received thymoglobulin; in all induction was initiated with no steroids. CONCLUSIONS: intestinal transplantation represents a therapeutic option that is applicable in our setting and valid for recipients with an indication who have no other feasible alternative to keep their intestinal failure under control.


Assuntos
Enteropatias/cirurgia , Intestino Delgado/transplante , Adulto , Feminino , Humanos , Enteropatias/patologia , Masculino , Complicações Pós-Operatórias , Espanha , Resultado do Tratamento
13.
Rev Esp Enferm Dig ; 98(11): 844-74, 2006 Nov.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-17198477

RESUMO

Non-alcoholic fatty liver disease represents a set of liver lesions similar to those induced by alcohol that develop in individuals with no alcohol abuse. When lesions consist of fatty and hydropic degeneration, inflammation, and eventually fibrosis, the condition is designated non-alcoholic steatohepatitis (NASH). The pathogenesis of these lesions is not clearly understood, but they are associated with insulin resistance in most cases. As a result, abdominal fat tissue lipolysis and excessive fatty acid uptake by the liver occur. This, together with a disturbance of triglyceride export as VLDL, results in fatty liver development. Both the inflammatory and hepatocellular degenerative components of NASH are attributed to oxidative stress. Mitochondrial respiratory chain loss of activity plays a critical role in the genesis of latter stress. This may be initiated by an increase in the hepatic TNFalpha, iNOS induction, peroxynitrite formation, tyrosine nitration and inactivation of enzymes making up this chain. Consequences of oxidative stress include: lipid peroxidation in cell membranes, stellate cell activation in the liver, liver fibrosis, chronic inflammation, and apoptosis.


Assuntos
Fígado Gorduroso/metabolismo , Resistência à Insulina/fisiologia , Mitocôndrias Hepáticas/metabolismo , Ensaios Clínicos como Assunto , Humanos , Estresse Oxidativo/fisiologia
14.
Rev Esp Enferm Dig ; 98(1): 25-35, 2006 Jan.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-16555930

RESUMO

OBJECTIVES: Propofol is a short-acting, hypnotic agent that is increasingly being used for gastrointestinal endoscopic sedation. There are concerns about the use of propofol by non anesthesiologists due to its potential for respiratory and cardiovascular depression. This report describes our experience concerning effectiveness and safety of propofol administered in endoscopic procedures by the endoscopist and the assistant nurse. METHODS: In this prospective study, a total of 102 consecutive endoscopies (60 colonoscopies and 42 upper endoscopies) performed under sedation with propofol were included. In 27 (26.47%) endoscopies propofol was administered alone and in 75 endoscopies (73.53%) it was combined with benzodiazepines and/or opioids. Seventy-six (74.51%) endoscopies were performed in patients under 65 years of age and 26 (25.49%) in patients over 65 years of age. Ninety-one (89.22%) endoscopies were performed in patients with low surgical risk (ASA I-II) and 11 (10.78%) in patients with high surgical risk. The medication was administered by the endoscopist that performed the procedure and the assistant nurse. RESULTS: The mean dose of propofol used was 72.14 mg for gastroscopies and 71.33 for colonoscopies (p = 0.92). The mean dose of propofol when infused alone was 84.81 mg whereas in combination with benzodiazepines/opioids was 66.93 mg (p = 0.06). The doses of propofol required were lower for those colonoscopies in which midazolam and/or meperidine was combined and in patients over 65 years of age (p = 0.006 y p = 0.001, respectively). Eleven (10.8%) minor complications were reported, and managed by the own endoscopist. Patients had no memories of the procedure. The tolerance rated by the endoscopist was excellent-good, fair, bad-very bad in 83, 5 and 12% of the gastroscopies and in 79, 8 and 13% of the colonoscopies respectively. Nevertheless bad tolerance did not hinder the completion of the procedure in any case. CONCLUSIONS: The administration of propofol by the endoscopist and the assistant nurse, is an effective and safe method of sedation in patients of low and high-risk as well as in elderly patients. The doses of propofol required for an adequate sedation were lower in patients over 65 years of age and for colonoscopies in which medication was combined.


Assuntos
Anestésicos Intravenosos/administração & dosagem , Sedação Consciente , Endoscopia , Propofol/administração & dosagem , Adolescente , Adulto , Idoso , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos
15.
Rev Esp Enferm Dig ; 98(3): 204-15, 2006 Mar.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-16737420

RESUMO

Inflammatory bowel disease commonly affects women with child-bearing potential, and clinical activity extent is most relevant at the time of conception. Below, we report on the case of a 19-year-old woman who was admitted for first-trimester metrorrhagia and fever, with various extraintestinal manifestations, mainly including erythema nodosum and episcleritis during the course of disease. The differential diagnosis of these manifestations led to the diagnosis of Crohn's disease, which involved the whole colon.


Assuntos
Doença de Crohn/diagnóstico , Complicações na Gravidez/diagnóstico , Adulto , Doença de Crohn/complicações , Feminino , Febre/etiologia , Humanos , Metrorragia/etiologia , Gravidez , Primeiro Trimestre da Gravidez
16.
Biochim Biophys Acta ; 1210(2): 195-201, 1994 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-8280770

RESUMO

Resident peritoneal macrophages synthesized and released eicosanoids when challenged by zymosan, a phagocytosable particle. Incubation of these cells with ethanol resulted in dose-dependent inhibition of arachidonic acid release and eicosanoid generation in response to zymosan. Ethanol affected the extent but not the ratio of eicosanoids released. When assayed in a cell-free system, endogenous phospholipase A2 activity was neither affected by the presence of ethanol in the incubation medium nor by preincubation of the cells with ethanol. Ethanol also inhibited arachidonic acid release in response to phorbol myristate acetate, a compound that, like zymosan, triggered a pertussis-toxin-sensitive response. When cells that had been previously treated with pertussis toxin were used, no further inhibitory effect of ethanol was seen in response to both zymosan and phorbol myristate acetate. On the other hand, ethanol had no effect on arachidonic acid release stimulated by ionophore A23187 or lipopolysaccharide, two compounds that triggered a pertussis-toxin-insensitive response. Moreover, ethanol was able to nearly abolish arachidonic acid release in response to fluoroaluminate, a direct activator of G-proteins. Altogether, the results of this study suggest that ethanol inhibits zymosan-stimulated eicosanoid production by interacting with a G-protein--or a G-protein-mediated process--that is critically involved in arachidonic acid mobilization.


Assuntos
Ácido Araquidônico/biossíntese , Etanol/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Zimosan/antagonistas & inibidores , Aciltransferases/metabolismo , Animais , Macrófagos Peritoneais/metabolismo , Camundongos , Toxina Pertussis , Fosfolipases A/metabolismo , Fosfolipases A2 , Fatores de Virulência de Bordetella/farmacologia
17.
Biochim Biophys Acta ; 1136(1): 75-82, 1992 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-1643116

RESUMO

Resident peritoneal macrophages release arachidonic acid when challenged by zymosan, a phagocytosable particle. The present study was designed to investigate the pathways for arachidonic acid mobilization in zymosan-stimulated macrophages. Experiments were conducted with [3H]arachidonic acid-labeled macrophages to establish the relative contribution of acyltransferases, phospholipase A2, and diacylglycerol lipase to overall arachidonic acid release. Upon zymosan stimulation, [3H]arachidonic acid incorporation into phospholipids was significantly enhanced. Stimulus-induced activation of arachidonic acid incorporated was not observed immediately, but was found 5 min after cell challenge. On the other hand, the results indicated a rapid accumulation of intracellular free [3H]arachidonic acid that paralleled the appearance of both [3H]glycerol-labeled lysophosphatidylcholine and [3H]glycerol-labeled lysophosphatidylinositol, the by-products of phospholipase A2 action on phosphatidylcholine and phosphatidylinositol, respectively. A transient accumulation of [3H]arachidonate-carrying diacylglycerol was also observed. However, no appreciable alterations in the levels of [3H]monoacylglycerol were found. The phospholipase A2 inhibitor nordihydroguaiaretic acid substantially prevented the zymosan-induced arachidonic acid release. In contrast, RHC 80267, a diacylglycerol lipase inhibitor, though preventing diacylglycerol breakdown, did not have any effect on [3H]arachidonic acid release From these results, it is concluded that: (1) the phospholipase A2 pathway controls arachidonic acid release upon zymosan stimulation; (2) the diacylglycerol lipase pathway appears not to be involved in arachidonic acid release by stimulated cells; (3) the acyltransferases play a remarkable role in controlling free arachidonic acid levels, but they do not participate in the increase of free fatty acid levels observed upon cell stimulation.


Assuntos
Ácido Araquidônico/metabolismo , Macrófagos/metabolismo , Zimosan/farmacologia , Aciltransferases/metabolismo , Animais , Células Cultivadas , Cicloexanonas/farmacologia , Relação Dose-Resposta a Droga , Ativação Enzimática , Lipase Lipoproteica/antagonistas & inibidores , Lipase Lipoproteica/metabolismo , Ativação de Macrófagos , Macrófagos/efeitos dos fármacos , Masoprocol/farmacologia , Camundongos , Peritônio , Fosfolipases A/antagonistas & inibidores , Fosfolipases A/metabolismo , Fosfolipases A2 , Soroalbumina Bovina/farmacologia
18.
Biochim Biophys Acta ; 1362(2-3): 135-44, 1997 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-9540844

RESUMO

To study the fibrogenic action of ethanol in vitro we used a co-culture system of freshly isolated hepatocytes and a liver stellate cell line (CFSC-2G) developed in our laboratory. Our results show that in this co-culture system ethanol induces the expression of alpha 1(I) procollagen mRNA in a dose- and time-dependent manner. This effect of ethanol was due to its metabolism by alcohol dehydrogenase since 4-methylpyrazole prevented the ethanol-mediated increase in alpha 1(I) procollagen mRNA. Ethanol was more efficient than acetaldehyde in inducing alpha 1(I) procollagen mRNA expression and its effect was protein synthesis-independent. Transfection of either hepatocytes or liver stellate cells with a reporter gene, chloramphenicol acetyl transferase (CAT), driven by 3700 bp of the mouse alpha 1(I) procollagen promoter demonstrated that only LSC expressed significant CAT activity and that this activity was enhanced by ethanol. Overall, our results suggest that this co-culture system is a useful model to study alcohol-induced fibrogenesis in vitro and that mechanisms other than acetaldehyde formation may also play an important role in alcohol-induced fibrogenesis.


Assuntos
Etanol/farmacologia , Fígado/efeitos dos fármacos , Pró-Colágeno/genética , Acetaldeído/farmacologia , Animais , Células Cultivadas , Fibronectinas/genética , Fomepizol , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Fígado/citologia , Fígado/metabolismo , Masculino , Pirazóis/farmacologia , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Transcrição Gênica/efeitos dos fármacos
20.
Cell Signal ; 10(3): 173-83, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9607140

RESUMO

We analyse the role of the G proteins in regulating collagen gene expression by measuring collagen alpha 1(I) mRNA levels in cultured hepatic stellate cells in basal conditions and after stimulating or inhibiting the major intracellular signalling pathways. Stimulation of Gs protein and adenylyl cyclase or the addition of 8Br-cAMP to the cells led to a decrease in collagen alpha 1(I) mRNA levels, while blocking protein kinase A abolished this effect. Blocking Gi protein, phospholipase A2 and C, calcium channels and calmodulin resulted in a significant increase in collagen mRNA levels. PKC stimulation led to a marked decrease in these levels. These results suggest that collagen gene expression is inhibited by a number of intracellular pathways. A Gs and a pertussis toxin-sensitive G protein seem to initiate cellular response. Transcription factors, acting in these pathways, must be identified. However, it seems that they do not need to be synthesised.


Assuntos
Adipócitos/metabolismo , Colágeno/genética , Proteínas de Ligação ao GTP/fisiologia , Regulação da Expressão Gênica/fisiologia , Fígado/metabolismo , Adenilil Ciclases/metabolismo , Animais , Cálcio/análise , Células Cultivadas , Toxina da Cólera/farmacologia , AMP Cíclico/análise , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Inibidores Enzimáticos/farmacologia , Fosfatos de Inositol/análise , Fígado/citologia , Cirrose Hepática Experimental , Fosfolipases A/metabolismo , Fosfolipases A2 , RNA Mensageiro/análise , Ratos , Transdução de Sinais/fisiologia , Fosfolipases Tipo C/metabolismo
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