Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
2.
Int J Cardiol ; 376: 165-171, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36738845

RESUMO

BACKGROUND: Myocarditis and inflammatory bowel diseases (IBD) are rare conditions, but may coexist. Myocarditis in IBD may be infective, immune-mediated, or due to mesalamine toxicity. A gap of knowledge exists on the clinical features of patients that present myocarditis in association with IBD, especially for endomyocardial biopsy-proven cases. Our aims are: 1) to describe the clinical characteristics of patients with an associated diagnosis of myocarditis and IBD in a single-center hospital, 2) to perform a systematic review of the literature of analogous cases. METHODS: We retrospectively analyzed data of patients followed up at the outpatient Cardio-immunology and Gastroenterology Clinic of Padua University Hospital, to identify those with an associated diagnosis of myocarditis and IBD. In addition, a systematic review of the literature was conducted. We performed a qualitative analysis of the overall study population. RESULTS: The study included 104 patients (21 from our single center cohort, 83 from the literature review). Myocarditis in IBD more frequently affects young (median age 31 years) males (72%), predominantly with infarct-like presentation (58%), within an acute phase of the IBD (67%) and with an overall benign clinical course (87%). Nevertheless, a not negligible quote of patients may present giant cell myocarditis, deserve immunosuppression and have a chronic, or even fatal course. Histological evidence of mesalamine hypersensitivity is scarce and its incidence may be overestimated. CONCLUSIONS: Our study shows that myocarditis in association with IBD, if correctly managed, may have a spontaneous benign course, but predictors of worse prognosis must be promptly recognized.


Assuntos
Doenças Inflamatórias Intestinais , Miocardite , Masculino , Humanos , Adulto , Miocardite/diagnóstico , Mesalamina , Estudos Retrospectivos , Doenças Inflamatórias Intestinais/complicações , Prognóstico
3.
Int J Cardiol ; 324: 221-226, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-32941866

RESUMO

AIMS: Left bundle branch block (LBBB) is usually associated with structural myocardial diseases progressively leading to left ventricular (LV) dysfunction. We sought to determine the mechanical implications of LBBB (as defined based on Strauss' criteria) by Cardiovascular Magnetic Resonance (CMR). METHOD AND RESULTS: We included consecutive patients referred to CMR to assess the structural cause of LBBB. CMR scans consisted of cine, stress perfusion, and late gadolinium enhancement (LGE) sequences. Myocardial deformation was assessed by tissue tracking analysis; LGE was quantified using the full width at half maximum method. We included 86 patients [63% male, 70 years (60-72)] with mean QRS duration 150 ± 13 msec. A structural disease was identified on CMR in 53% of patients (ischemic heart disease, IHD, 31%; non-ischemic heart disease, NIHD, 22%), while LBBB-related septal dyssynchrony (SD) was the only abnormality in 47%. LGE was found in 42% of patients. LVEF and myocardial deformation were impaired. Despite similar ECG characteristics, myocardial strain differed significantly between IHD, NIHD and SD patients, and patients with SD showed less impaired myocardial deformation. Indexed LV end-systolic volume and LGE extent were independently associated with impaired strain. CONCLUSIONS: Patients with LBBB show different structural and mechanical properties, and LGE extent has an unfavourable effect on myocardial mechanics.


Assuntos
Bloqueio de Ramo , Disfunção Ventricular Esquerda , Bloqueio de Ramo/diagnóstico por imagem , Meios de Contraste , Feminino , Gadolínio , Humanos , Imagem Cinética por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Masculino , Miocárdio , Volume Sistólico , Função Ventricular Esquerda
4.
J Endocrinol Invest ; 42(9): 1099-1107, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30847862

RESUMO

PURPOSE: In patients with type 1 diabetes (T1D), the prevalence of non-alcoholic fatty liver disease (NAFLD) ranges from 10 to 53% and contrasting evidence suggests that vitamin D deficiency may favor liver fat accumulation. Here, we investigated the association between vitamin D status and NAFLD in adults with T1D. METHODS: 220 consecutive adult T1D patients on multiple daily injections or continuous subcutaneous insulin infusion and not taking calcium or vitamin D supplements were included. Patient characteristics, 25(OH)D serum levels, and metabolic parameters were analyzed. Vitamin D status was defined as sufficiency ( ≥ 75 nmol/L; 30 ng/ml), insufficiency (50-75 nmol/L; 20-30 ng/ml), or deficiency ( < 50 nmol/L; 20 ng/ml). NAFLD was diagnosed at ultrasound examination and graded 0-3. RESULTS: NAFLD was present in 57 patients (29.5%): 51 grade 1, 5 grade 2, and 1 grade 3. Median 25(OH)D levels were 53 nmol/L (IQR 38-70) in patients with NAFLD and 50 nmol/L (34-69) in patients without (p = 0.46). At multivariable analysis, NAFLD was not associated with 25(OH)D levels (p = 0.42) or vitamin D deficiency (p = 0.55), while BMI (OR 1.16, 95% CI 1.07-1.27) and serum triglycerides (OR 1.02, 95% CI 1.01-1.03) were independently associated with NAFLD. CONCLUSIONS: Vitamin D status appears to have no link with low-grade NAFLD in patients with type 1 diabetes.


Assuntos
Biomarcadores/sangue , Diabetes Mellitus Tipo 1/fisiopatologia , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Deficiência de Vitamina D/complicações , Vitamina D/sangue , Vitaminas/sangue , Adolescente , Adulto , Estudos Transversais , Feminino , Seguimentos , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/etiologia , Prevalência , Prognóstico , Estudos Prospectivos , Adulto Jovem
5.
Clin Radiol ; 74(3): 228-234, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30685060

RESUMO

AIM: To assess the role of cardiovascular magnetic resonance imaging (CMRI) in patients referred for suspected arrhythmogenic right ventricular cardiomyopathy (ARVC), its ability to identify ARVC mimics, and subsequent clinical impact. MATERIALS AND METHODS: The CMRI registry of the year 2014 was analysed to identify all consecutive patients referred for suspected ARVC. A comprehensive CMRI protocol that included anatomy, bi-ventricular function modules, and late gadolinium enhancement (LGE) was performed in all patients. RESULTS: Out of 2,481 CMRI performed, 124 patients (5%) were referred for suspected ARVC. A pathological substrate was identified at CMRI in 36 patients (29%): five patients (4%) had ischaemic heart disease (IHD) and 10 (8%) non-IHD; five patients (4%) met CMRI criteria for ARVC and 16 (13%) were ARVC mimics. right ventricular end-diastolic volume (RVEDV) and right ventricular stroke volume (RVSV) were significantly higher in patients with ARVC mimics (RVEDV p=0.007, RVSV p=0.012) and ARVC (RVEDV p=0.013, RVSV p=0.013), as compared to those with structurally normal hearts. CMRI was superior to echocardiography in the identification of ARVC mimics (13% versus 1%, p=0.01). CONCLUSIONS: CMRI was able to identify 16 (13%) ARVC mimics, from congenital abnormalities to acquired heart disease. CMRI was superior in identifying ARVC mimics compared to echocardiography, and overall provided a change in diagnosis in 22% of patients.


Assuntos
Displasia Arritmogênica Ventricular Direita/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Meios de Contraste , Diagnóstico Diferencial , Ecocardiografia , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Organometálicos , Sistema de Registros , Estudos Retrospectivos
6.
Int J Cardiovasc Imaging ; 34(1): 67-80, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28315985

RESUMO

Cardiovascular magnetic resonance (CMR) is a multi-parametric, multi-planar, non-invasive imaging technique, which allows accurate determination of biventricular function and precise myocardial tissue characterization in a one-stop-shop technique, free from the use of ionizing radiations. Though CMR has been increasingly applied over the last two decades in every-day clinical practice, its widest application has been in the assessment of ischemic cardiomyopathy.


Assuntos
Cardiomiopatias/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Isquemia Miocárdica/diagnóstico por imagem , Imagem de Perfusão/métodos , Doença Aguda , Cardiomiopatias/patologia , Cardiomiopatias/fisiopatologia , Doença Crônica , Humanos , Isquemia Miocárdica/patologia , Isquemia Miocárdica/fisiopatologia , Miocárdio/patologia , Valor Preditivo dos Testes , Prognóstico , Fatores de Risco , Sobrevivência de Tecidos , Função Ventricular Esquerda , Função Ventricular Direita , Remodelação Ventricular
7.
Int J Cardiol ; 244: 335-339, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28676244

RESUMO

BACKGROUND: Atrio-ventricular block (AVB) is a rare finding in young or middle-aged adults, often leading to pacemaker implantation (PM) without further investigation. We sought to assess the diagnostic role of cardiovascular magnetic resonance (CMR) in young and middle-aged adults with high-grade AVB. METHODS: We consecutively enrolled young-middle aged (18-65years) patients with high grade AVB referred to CMR after standard clinical assessment (history, electrocardiogram and cardiac rhythm monitoring) prior to PM implantation. Cine and post-contrast imaging were performed in a 1.5T scanner. RESULTS: 34 patients (59% male, mean age 42±12years) with high grade AVB were referred to CMR for suspected ischemic heart disease (IHD)(n=4) and non-ischemic heart disease (NIHD)(n=20); no clear cause was found in 9 patients prior to CMR and 1 patient had suspected lung disease. A pathologic substrate was found on CMR in 15 patients (44%), while a structurally normal heart was reported in 18 (53%). Non-specific findings were reported in 1 patient (3%). There was a fair agreement between CMR and echocardiographic findings (Cohen's kappa 0.243), and CMR provided an entirely new diagnosis in 34% of patients. As compared to the standard clinical assessment, CMR had an additional role in 65% of patients and guided further testing (genetic testing, extra-cardiac imaging) in 9%. CONCLUSIONS: CMR found a pathologic substrate in 44% of patients, mainly NIHD (32%). Half of the patients (53%) had a structurally normal heart. When added to the standard clinical assessment, CMR had an incremental diagnostic role in two thirds of patients.


Assuntos
Bloqueio Atrioventricular/diagnóstico por imagem , Bloqueio Atrioventricular/fisiopatologia , Imagem Cinética por Ressonância Magnética/métodos , Adulto , Fatores Etários , Eletrocardiografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
8.
Heart Fail Rev ; 22(4): 465-476, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28620745

RESUMO

The objective assessments of left ventricular (LV) and right ventricular (RV) ejection fractions (EFs) are the main important tasks of routine cardiovascular magnetic resonance (CMR). Over the years, CMR has emerged as the reference standard for the evaluation of biventricular morphology and function. However, changes in EF may occur in the late stages of the majority of cardiac diseases, and being a measure of global function, it has limited sensitivity for identifying regional myocardial impairment. On the other hand, current wall motion evaluation is done on a subjective basis and subjective, qualitative analysis has a substantial error rate. In an attempt to better quantify global and regional LV function; several techniques, to assess myocardial deformation, have been developed, over the past years. The aim of this review is to provide a comprehensive compendium of all the CMR techniques to assess myocardial deformation parameters as well as the application in different clinical scenarios.


Assuntos
Cardiopatias/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Miocárdio/patologia , Coração/diagnóstico por imagem , Cardiopatias/patologia , Cardiopatias/fisiopatologia , Humanos , Volume Sistólico , Função Ventricular
9.
Resuscitation ; 116: 91-97, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28373095

RESUMO

BACKGROUND: Non-traumatic out of hospital cardiac arrest (OHCA) is the leading cause of death worldwide, mainly due to acute coronary syndromes. Urgent coronary angiography with view to revascularisation is recommended in patients with suspected acute coronary syndrome. Diagnosis and management of patients with inconclusive coronary angiogram (unobstructed coronaries or unidentified culprit lesion) is challenging. We sought to assess the role of Cardiovascular Magnetic Resonance (CMR) in the diagnosis and management of OHCA survivors with an inconclusive coronary angiogram. METHODS AND RESULTS: This is a retrospective multicentre CMR registry analysis of OHCA survivors with an inconclusive angiogram. Clinical, ECG and multi-modality imaging data were analysed. Clinical impact of CMR was defined as a change in diagnosis or management. Out of 174 OHCA survivors referred for CMR, 110 patients (63%, 84 male, median age 58) had an inconclusive angiogram. CMR identified a pathologic substrate in 76/110 patients (69%): ischemic heart disease was found in 45 (41%) and non-ischemic heart disease in 31 (28%). A structurally normal heart was found in 25 patients (23%) and non-specific findings in 9 (8%). As compared to trans-thoracic echocardiogram, CMR proved to be superior in identifying a pathologic substrate (69% vs 54%, p=0.018). The CMR study carried a clinical impact in 70% of patients, determining a change in diagnosis in 25%, in management in 29% and a change in both in 16%. CONCLUSIONS: CMR showed a promising role in the diagnostic work-up of OHCA survivors with inconclusive angiogram and its wider use should be considered.


Assuntos
Síndrome Coronariana Aguda/diagnóstico , Eletrocardiografia , Cardiopatias/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Parada Cardíaca Extra-Hospitalar/terapia , Doença Aguda , Idoso , Angiografia Coronária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sobreviventes/estatística & dados numéricos
11.
Diabet Med ; 25(3): 326-32, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18307459

RESUMO

AIMS: The superiority of continuous subcutaneous insulin infusion (CSII) over multiple daily injections (MDI) with glargine is uncertain. In this randomized cross-over study, we compared CSII and MDI with glargine in patients with Type 1 diabetes well controlled with CSII. The primary end-point was glucose variability. METHODS: Thirty-nine patients [38.1 +/- 9.3 years old (mean +/- sd), diabetes duration 16.6 +/- 8.2 years, glycated haemoglobin (HbA(1c)) 7.6 +/- 0.8%], already on CSII for at least 6 months, were randomly assigned to CSII with lispro or MDI with lispro and glargine. After 4 months they were switched to the alternative treatment. During the last month of each treatment blood glucose variability was analysed using glucose standard deviation, mean amplitude of glycaemic excursions (MAGE), lability index and average daily risk range (ADRR). As secondary end-points we analysed blood glucose profile, HbA(1c), number of episodes of hypo- and hyperglycaemia, lipid profile, free fatty acids (FFA), growth hormone and treatment satisfaction. RESULTS: During CSII, glucose variability was 5-12% lower than during MDI with glargine. The difference was significant only before breakfast considering glucose standard deviation (P = 0.011), significant overall using MAGE (P = 0.016) and lability index (P = 0.005) and not significant using ADRR. Although HbA(1c) was similar during both treatments, during CSII blood glucose levels were significantly lower, hyperglycaemic episodes were fewer, daily insulin dose was less, FFA were lower and treatment satisfaction was greater than during MDI with glargine. The frequency of hypoglycaemic episodes was similar during both treatments. CONCLUSIONS: During CSII, glucose variability is lower, glycaemic control better and treatment satisfaction higher than during MDI with glargine.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 1/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Insulina/análogos & derivados , Diabetes Mellitus Tipo 1/sangue , Relação Dose-Resposta a Droga , Humanos , Injeções , Insulina/administração & dosagem , Insulina Glargina , Sistemas de Infusão de Insulina , Insulina de Ação Prolongada , Satisfação do Paciente , Estatística como Assunto
12.
Diabetes Metab ; 32(3): 256-61, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16799403

RESUMO

AIM: Diabetic patients should understand their disease correctly and be sure of what they know, but certainty is rarely considered by educators. Furthermore little is known about how certainty changes with time after an educational intervention. To clarify this, in 38 patients with type 1 diabetes (0.3-36 years duration) we analysed the effect of a course on insulin use by administering a questionnaire before the course, after the course and 1 and 3 years later. METHODS: Answers, accompanied by a subjective estimate of the degree of certainty, were assigned to mastered knowledge (certainty>or=90%, correctness>or=90%), hazardous knowledge (certainty>or=90%, correctnessor=90%) and residual knowledge (total-[mastered+hazardous+uncertain]). Answers were then counted and changes in distribution among areas were analysed by the chi2 test. We also followed the fate of wrong answers. RESULTS: The course increased mastered knowledge, while other types of knowledge decreased. With time mastered knowledge decreased, patients losing both correctness and certainty. The loss affected declarative knowledge, based purely on theory, more than procedural knowledge, which concerns the way things are done. Wrong answers, mostly given with high degree of certainty, were heterogeneous since some became correct after the course, some remained wrong, some became wrong after the course, some became mistaken after having been corrected earlier. CONCLUSIONS: The analysis of certainty helps in evaluating patient's knowledge; programmes tending to improve procedural knowledge are more likely to have long lasting effects; wrong answers need to be considered on a individual basis.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/reabilitação , Conhecimentos, Atitudes e Prática em Saúde , Insulina/uso terapêutico , Educação de Pacientes como Assunto , Avaliação Educacional , Humanos , Ensino/métodos
13.
Protein Expr Purif ; 45(1): 142-9, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16146695

RESUMO

The IgA1 protease of Streptococcus pneumoniae is a Zn-metalloproteinase of 1964 amino acids that specifically cleaves the hinge region of IgA1, the predominant class of immunoglobulin present on mucosal membranes. This protease is associated to the bacterial cell surface via an N-terminal membrane anchor. Following proteolysis it is released in several forms of different molecular weight. Here, we describe the cloning, expression, and characterization of the enzymatic activity and immunogenicity of three fragments of IgA1 protease, including a large one lacking only the 103 N-terminal amino acids that constitute a typical prokaryotic signal sequence. Further, a proteolytically inactive mutant was generated by replacement of the glutamate residue with an alanine residue in the active site motif HExxH (1605-1609). This is the first report of recombinant active forms of S. pneumoniae IgA1 protease, which open the possibility of identifying specific inhibitors that could interfere with the mucosal colonization by pneumococcus. Moreover the inactive mutant could be considered as a candidate vaccine component.


Assuntos
Regulação Enzimológica da Expressão Gênica , Pneumonia Pneumocócica/genética , Serina Endopeptidases , Streptococcus pneumoniae/enzimologia , Clonagem Molecular , Humanos , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Serina Endopeptidases/genética , Serina Endopeptidases/isolamento & purificação , Serina Endopeptidases/metabolismo
14.
Eur Respir J ; 19(6): 1128-35, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12108868

RESUMO

Previous studies have shown that surfactant apoprotein A (SP-A) and natural or synthetic surfactant can modulate the release of pro-inflammatory cytokines from alveolar mononuclear phagocytes. The aim of this study was to assess whether SP-A or Surfactant (Surf) from patients with pulmonary alveolar proteinosis (PAP) can affect the release of two chemokines (interleukin (IL)-8 and monocyte chemtactic peptide (MCP)-1) from human monocytes and rat lung type-II cells. In addition IL-8 and MCP-1 levels were assessed in the brochoalveolar lavage fluid (BALF) of seven patients with PAP and compared with those in a group of control subjects (n=5). SP-A, tested over a wide range of concentrations, significantly increased IL-8 and MCP-1 release from monocytes. SP-A retained its activity after collagenase digestion, but was not active after heat treatment. The release of IL-8 by monocytes was also stimulated by Surf. Finally, median BALF IL-8 and MCP-1 levels in PAP patients were significantly higher than in controls (9.50 and 9.51 pg x mL(-1) in controls versus 151.95 and 563.70 pg x mL(-1) in PAP, respectively) and significantly correlated with SP-A concentrations in BALF. Overall the results of this study support the view that the high content of alveolar surfactant apoprotein A may contribute to the upregulation of chemokine release in pulmonary alveolar proteinosis, thus contributing to airway inflammation.


Assuntos
Quimiocina CCL2/biossíntese , Interleucina-8/biossíntese , Proteinose Alveolar Pulmonar/metabolismo , Proteína A Associada a Surfactante Pulmonar/farmacologia , Adulto , Animais , Líquido da Lavagem Broncoalveolar/química , Células Cultivadas , Quimiocina CCL2/análise , Feminino , Humanos , Interleucina-8/análise , Masculino , Pessoa de Meia-Idade , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Proteinose Alveolar Pulmonar/imunologia , Ratos , Mucosa Respiratória/citologia , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/metabolismo
15.
Diabet Med ; 19(8): 628-34, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12147142

RESUMO

AIM: To study the effect of continuous subcutaneous insulin infusion (CSII) on metabolic control and well-being in patients with Type 1 diabetes. METHODS: Efficacy, safety and interference with everyday life associated with CSII were studied retrospectively in 138 diabetic patients from the Veneto region treated for 7.4 +/- 0.4 years. RESULTS: Glycosylated haemoglobin decreased during the first year of CSII from 9.3 +/- 0.2% to 7.9 +/- 0.1% (P < 0.0001), and then remained unchanged. Serious hypoglycaemia decreased from 0.31 +/- 0.07/year to 0.09 +/- 0.02/year (P < 0.003), as did ketoacidosis (from 0.41 +/- 0.12/year to 0.11 +/- 0.03/year, P < 0.013). During the first year of therapy daily insulin requirement decreased from 49 +/- 1 to 42 +/- 2 U/day (P < 0.0001) and did not change thereafter. The number of out-patient consultations and hospital admissions per year also decreased significantly. CSII was associated with a progressive increase of body weight (P < 0.05) and with 0.2 +/- 0.04 infections/patient per year at the infusion site. Infection was rated as mild in 72%, moderate in 18%, severe in 10%. Patients reported that CSII improved metabolic control (71%), sense of well-being (41%), and allowed more freedom (40%). Quality of life, assessed using the DQOL, after 7 years of CSII was rated as good by patients (score of 73.0 +/- 1.8 on a scale from 0 to 100). CONCLUSIONS: This retrospective analysis suggests that CSII improves metabolic control in Type 1 diabetic patients, reduces hypoglycaemic and ketoacidotic events, is well accepted, allows a good quality of life and decreases out-patient consultations and hospital admissions.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Hemoglobinas Glicadas/análogos & derivados , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Administração Cutânea , Adulto , Diabetes Mellitus Tipo 1/metabolismo , Cetoacidose Diabética/etiologia , Cetoacidose Diabética/prevenção & controle , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemia/etiologia , Hipoglicemia/prevenção & controle , Sistemas de Infusão de Insulina , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Estudos Retrospectivos
16.
Am J Physiol Lung Cell Mol Physiol ; 281(5): L1189-99, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11597911

RESUMO

Amiodarone may induce lung damage by direct toxicity or indirectly through inflammation. To clarify the mechanism of direct toxicity, we briefly exposed rabbit alveolar macrophages to amiodarone and analyzed their morphology, synthesis, and degradation of dipalmitoylphosphatidylcholine (DPPC); distribution of lysosomal enzymes; and uptake of diphtheria toxin and surfactant protein (SP) A used as tracers of the endocytic pathway. Furthermore, in newborn rabbits, we studied the clearance of DPPC and SP-A instilled into the trachea together with increasing amounts of amiodarone. We found that in vitro amiodarone decreases the surface density of mitochondria and lysosomes while increasing the surface density of inclusion bodies, increases the incorporation of choline into DPPC, modifies the distribution of lysosomal enzymes, and does not affect the uptake and processing of diphtheria toxin but inhibits the degradation of SP-A. In vivo amiodarone inhibits the degradation of SP-A but not of DPPC. We conclude that the acute exposure to amiodarone perturbs the endocytic pathway acting after the early endosomes, alters the traffic of lysosomal enzymes, and interferes with the turnover of SP-A.


Assuntos
Amiodarona/toxicidade , Pulmão/efeitos dos fármacos , Lisossomos/enzimologia , Macrófagos Alveolares/efeitos dos fármacos , Proteolipídeos/metabolismo , Surfactantes Pulmonares/metabolismo , 1,2-Dipalmitoilfosfatidilcolina/metabolismo , 1,2-Dipalmitoilfosfatidilcolina/farmacologia , Animais , Líquido da Lavagem Broncoalveolar/química , Tamanho Celular , Sobrevivência Celular , Células Cultivadas , Colina/metabolismo , Toxina Diftérica/farmacologia , Endocitose/fisiologia , Pulmão/metabolismo , Lisossomos/metabolismo , Macrófagos Alveolares/fisiologia , Macrófagos Alveolares/ultraestrutura , Proteína A Associada a Surfactante Pulmonar , Proteínas Associadas a Surfactantes Pulmonares , Coelhos , Radioisótopos/metabolismo , beta-N-Acetil-Hexosaminidases/metabolismo
17.
Am J Physiol Lung Cell Mol Physiol ; 279(1): L91-9, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10893207

RESUMO

Alveolar macrophages degrade surfactant protein (SP) A and saturated phosphatidycholine [dipalmitoylphosphatidylcholine (DPPC)]. To clarify this process, using rabbit alveolar macrophages, we analyzed the effect of drugs known to affect phagocytosis, pinocytosis, clathrin-mediated uptake, caveolae, the cytoskeleton, lysosomal pH, protein kinase C, and phosphatidylinositol 3-kinase (PI3K) on the degradation of SP-A and DPPC. We found the following: 1) SP-A binds to the plasma membrane, is rapidly internalized, and then moves toward degradative compartments. Uptake could be clathrin mediated, whereas phagocytosis, pinocytosis, or the use of caveolae are less likely. An intact cytoskeleton and an acidic milieu are necessary for the degradation of SP-A. 2) Stimulation of protein kinase C increases the degradation of SP-A. 3) PI3K influences the degradation of SP-A by regulating both the speed of internalization and subsequent intracellular steps, but its inhibition does not prevent SP-A from reaching the lysosomal compartment. 4) The degradation of DPPC is unaffected by most of the treatments able to influence the degradation of SP-A. Thus it appears that DPPC is degraded by alveolar macrophages through mechanisms very different from those utilized for the degradation of SP-A.


Assuntos
Macrófagos Alveolares/metabolismo , Fosfatidilcolinas/metabolismo , Proteolipídeos/metabolismo , Surfactantes Pulmonares/metabolismo , 1,2-Dipalmitoilfosfatidilcolina/metabolismo , Animais , Citoesqueleto/fisiologia , Lisossomos/metabolismo , Macrófagos Alveolares/ultraestrutura , Fosfatidilinositol 3-Quinases/fisiologia , Proteína Quinase C/metabolismo , Proteína A Associada a Surfactante Pulmonar , Proteínas Associadas a Surfactantes Pulmonares , Coelhos
18.
Eur Respir J ; 12(2): 294-300, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9727777

RESUMO

This paper examines the removal from the airways of Curosurf, a commercial surfactant derived from porcine lungs, administered at pharmacological concentrations to newborn or adult animals. Curosurf was labelled by the addition of radioactive dipalmitoyl phosphatidylcholine (DPPC) and administered intratracheally to newborn and adult rabbits at a dose of 200 mg x kg(-1) body weight. The disappearance of DPPC from the airways and its appearance in alveolar macrophages, lung parenchyma, lamellar bodies, serum, liver, kidneys and brain was then studied for 24-48 h. The in vitro degradation of Curosurf DPPC by alveolar macrophages was also studied. During the first 3 h after instillation, large amounts of Curosurf left the airways and became associated with tissue, indicating that it mixed rapidly with the endogenous pools of surfactant. A fraction of administered DPPC became associated with the lamellar bodies, suggesting that Curosurf can be recycled. Curosurf administration did not stop the secretion of endogenous surfactant. Very little intact radioactive DPPC could be recovered at any time in alveolar macrophages, however, macrophages have the ability, in vitro, to degrade Curosurf. Newborn rabbits lose Curosurf from the lungs at a slower rate than adult rabbits. One and two days after instillation, organic extracts from the liver, kidney, brain and serum contained small but measurable amounts of radioactivity. These results indicate that Curosurf rapidly enters the pathways of surfactant metabolism and that alveolar macrophages may play an important role in the catabolism of Curosurf.


Assuntos
Produtos Biológicos , Macrófagos Alveolares/metabolismo , Fosfolipídeos , Surfactantes Pulmonares/farmacocinética , 1,2-Dipalmitoilfosfatidilcolina , Animais , Animais Recém-Nascidos , Radioisótopos de Carbono , Feminino , Instilação de Medicamentos , Intubação Intratraqueal , Pulmão/metabolismo , Surfactantes Pulmonares/administração & dosagem , Coelhos , Fatores de Tempo , Distribuição Tecidual
19.
Am J Physiol ; 274(5): L737-49, 1998 05.
Artigo em Inglês | MEDLINE | ID: mdl-9612289

RESUMO

Serum lipoproteins may enter the airways and appear in sputum (chyloptysis) when the lymphatic circulation is impaired by inflammation, neoplasia, or an abnormal proliferation of smooth muscle cells. While analyzing the bronchoalveolar lavage fluid of a patient with chyloptysis, we noticed that surfactant could not be separated from contaminating serum lipoproteins and speculated that lipoproteins might interact with surfactant components. To clarify this point we immobilized surfactant protein (SP) A on microtiter wells and incubated it with 125I-labeled very low density lipoproteins (VLDLs), low-density lipoproteins, and high-density lipoproteins. We found that SP-A binds lipoproteins. Studying in greater detail the interaction of SP-A with VLDLs, we found that the binding is time and concentration dependent; is inhibited by unlabeled lipoproteins, phospholipids, and antibodies to SP-A; is increased by Ca2+; and is unaffected by methyl alpha-D-mannopyranoside. Whole surfactant is a potent inhibitor of binding. Furthermore, we found that SP-A increases the degradation of VLDLs by alveolar macrophages and favors the association of VLDLs with alveolar surfactant. We conclude that SP-A influences the disposal of serum lipoproteins entering the airways and speculate that binding to alveolar surfactant might represent an important step in the interaction between exogenous substances and the lung.


Assuntos
Quilotórax/fisiopatologia , Lipoproteínas/sangue , Lipoproteínas/metabolismo , Pulmão/metabolismo , Proteolipídeos/fisiologia , Surfactantes Pulmonares/fisiologia , Líquido da Lavagem Broncoalveolar/química , Feminino , Humanos , Lipoproteínas VLDL/metabolismo , Macrófagos Alveolares/metabolismo , Microscopia Eletrônica , Pessoa de Meia-Idade , Proteína A Associada a Surfactante Pulmonar , Proteínas Associadas a Surfactantes Pulmonares
20.
Am J Respir Crit Care Med ; 154(3 Pt 1): 817-20, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8810625

RESUMO

In patients with idiopathic alveolar proteinosis, the alveoli are filled with materials rich in surfactant components, especially surfactant protein A (SP-A). The anomaly could be caused by either increased secretion, decreased clearance, or both. To clarify this point, we studied five patients who underwent therapeutic lavage and then were ventilated mechanically for 24 h. During the first 8 h of mechanical ventilation, a surfactant-depleted lung was lavaged at selected intervals, and the bronchoalveolar lavage fluid was analyzed. We observed that, after lavage, various surfactant components accumulated in the airways with different time courses. We also observed that SP-A increased until the second hour and then dropped rapidly, suggesting the existence of an efficient mechanism of removal. These findings suggest that idiopathic alveolar proteinosis might be caused by a primary defect in a slow mechanism of removal or by the presence of factor(s) that interfere with the clearance of surfactant and that can be removed by lavage. It seems clear, however, that an increased secretion rate is unlikely to be the major cause of idiopathic alveolar proteinosis.


Assuntos
Líquido da Lavagem Broncoalveolar/química , Proteolipídeos/metabolismo , Proteinose Alveolar Pulmonar/metabolismo , Surfactantes Pulmonares/metabolismo , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fosfolipídeos/análise , Proteolipídeos/análise , Proteinose Alveolar Pulmonar/terapia , Proteína A Associada a Surfactante Pulmonar , Proteínas Associadas a Surfactantes Pulmonares , Surfactantes Pulmonares/análise , Respiração Artificial , Irrigação Terapêutica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...