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2.
Cardiol Young ; 32(7): 1112-1120, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34521491

RESUMO

BACKGROUND: Diagnosis of sinus venosus defects, not infrequently associated with complex anomalous pulmonary venous drainage, may be delayed requiring multimodality imaging. METHODS: Retrospective review of all patients from February 2008 to January 2019. RESULTS: Thirty-seven children were diagnosed at a median age of 4.2 years (range 0.5-15.5 years). In 32 of 37 (86%) patients, diagnosis was achieved on transthoracic echocardiography, but five patients (14%) had complex variants (four had high insertion of anomalous vein into the superior caval vein and three had multiple anomalous veins draining to different sites, two of whom had drainage of one vein into the high superior caval vein). In these five patients, the final diagnosis was achieved by multimodality imaging and intra-operative findings. The median age at surgery was 5.2 years (range 1.6-15.8 years). Thirty-one patients underwent double patch repair, four patients a Warden repair, and two patients a single-patch repair. Of the four Warden repairs, two patients had a high insertion of right-sided anomalous pulmonary vein into the superior caval vein, one patient had bilateral superior caval veins, and one patient had right lower pulmonary vein insertion into the right atrium/superior caval vein junction. There was no post-operative mortality, reoperation, residual shunt or pulmonary venous obstruction. One patient developed superior caval vein obstruction and one patient developed atrial flutter. CONCLUSION: Complementary cardiac imaging modalities improve diagnosis of complex sinus venosus defects associated with a wide variation in the pattern of anomalous pulmonary venous connection. Nonetheless, surgical treatment is associated with excellent outcomes.


Assuntos
Comunicação Interatrial , Veias Pulmonares , Síndrome de Cimitarra , Malformações Vasculares , Adolescente , Criança , Pré-Escolar , Comunicação Interatrial/diagnóstico por imagem , Comunicação Interatrial/cirurgia , Humanos , Lactente , Veias Pulmonares/anormalidades , Veias Pulmonares/diagnóstico por imagem , Veias Pulmonares/cirurgia , Síndrome de Cimitarra/diagnóstico por imagem , Síndrome de Cimitarra/cirurgia , Resultado do Tratamento , Veia Cava Superior/anormalidades , Veia Cava Superior/diagnóstico por imagem , Veia Cava Superior/cirurgia
3.
For Policy Econ ; 111: 102032, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32140044

RESUMO

The quantification of forests available for wood supply (FAWS) is essential for decision-making with regard to the maintenance and enhancement of forest resources and their contribution to the global carbon cycle. The provision of harmonized forest statistics is necessary for the development of forest associated policies and to support decision-making. Based on the National Forest Inventory (NFI) data from 13 European countries, we quantify and compare the areas and aboveground dry biomass (AGB) of FAWS and forest not available for wood supply (FNAWS) according to national and reference definitions by determining the restrictions and associated thresholds considered at country level to classify forests as FAWS or FNAWS. FAWS represent between 75 and 95 % of forest area and AGB for most of the countries in this study. Economic restrictions are the main factor limiting the availability of forests for wood supply, accounting for 67 % of the total FNAWS area and 56 % of the total FNAWS AGB, followed by environmental restrictions. Profitability, slope and accessibility as economic restrictions, and protected areas as environmental restrictions are the factors most frequently considered to distinguish between FAWS and FNAWS. With respect to the area of FNAWS associated with each type of restriction, an overlap among the restrictions of 13.7 % was identified. For most countries, the differences in the FNAWS areas and AGB estimates between national and reference definitions ranged from 0 to 5 %. These results highlight the applicability and reliability of a FAWS reference definition for most of the European countries studied, thereby facilitating a consistent approach to assess forests available for supply for the purpose of international reporting.

4.
Ir J Med Sci ; 188(2): 475-479, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-29943216

RESUMO

BACKGROUND: We describe the long-term results of partial atrioventricular septal defect (AVSD) repair in a single centre encompassing a 22-year period. Described are rates of survival, reoperation and complications. METHODS: We performed a retrospective review of 556 patients undergoing AVSD repair to identify the 51 patients who underwent partial AVSD repair in Our Lady's Children's Hospital, Crumlin, Ireland, between 1993 and 2015 with long-term follow-up where available. RESULTS: A total of 29 (56.8%) of patients were male and mean age at operation was 3.32 years. Mean weight was 13.2 kg. Trisomy 21 was present in 29 (56.8%). Five patients (9.6%) had undergone prior surgery. Mean cardiopulmonary bypass time was 89 ± 36 min and mean aortic cross-clamp time was 57 ± 28 min. One patient underwent partial AVSD repair and concomitant tracheal resection and extracorporeal membrane oxygenation decannulation. One patient was managed with suture atrial septal defect (ASD) closure, the remainder with patch repair of ASD and mitral cleft closure. The length of hospital stay was 9 ± 5 days. Median follow-up was 6.06 years (IQR, 1.65-10.2 years). There were no early mortalities. One patient died 1 year following surgery (1.9%). One patient required reoperation at an interval of 2 years for severe mitral regurgitation (1.9%). CONCLUSIONS: Short- and long-term survival following partial AVSD repair in Ireland revealed excellent results compared with other published series. Reoperation incidence also compared excellently with other reports published in the literature.


Assuntos
Procedimentos Cirúrgicos Cardíacos/métodos , Comunicação Interventricular/cirurgia , Defeitos dos Septos Cardíacos/cirurgia , Adolescente , Criança , Pré-Escolar , Feminino , Defeitos dos Septos Cardíacos/patologia , Comunicação Interventricular/patologia , Humanos , Lactente , Irlanda , Masculino , Complicações Pós-Operatórias , Estudos Retrospectivos , Resultado do Tratamento
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 5998-6001, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30441703

RESUMO

Early detection and discrimination of cardiac arrhythmia, atrial fibrillation (AF) in particular, is essential for timely intervention to improve patient outcomes. In this work, an algorithm was developed to classify ECG records as normal, AF, other arrhythmia, or too noisy to classify. This algorithm, which was an entry for the PhysioNet Computing in Cardiology Challenge 2017 (the Challenge), is described. Artifact masking and QRS detection were applied to lead-I equivalent ECG records and 17 features were extracted which captured the irregularity of the RR intervals, the PQRST morphology, and artifact/noise. An ensemble of ten neural networks (NN) was trained on the features from a training set of 5,970 records. A final classification was taken by majority vote over the 10 classifiers. The trained NN models were validated on a further 2,558 ECG records and then tested on a blind out-of-sample test set of 3,658 records. A mean $F_{1}$ score across the four classes of 0.78 for the training/validation sets and 0.80 for the testing set was achieved. A higher $F_{1}$ score for the testing set indicates that overtraining did not occur, unlike most entries to the Challenge (winner mean $F_{1}$ score of 0.89 for training/validation set, and 0.83 for testing set). Performance of the Challenge winner was not ideal and there is evidence of overtraining, indicating the difficulty of classifying AF from single-lead ECG. The features and method described here performed comparably and overtraining did not occur (high likelihood of generalization) indicating a good starting point for future work.


Assuntos
Algoritmos , Fibrilação Atrial/diagnóstico , Eletrocardiografia , Redes Neurais de Computação , Artefatos , Humanos
6.
Ir J Med Sci ; 187(2): 521-524, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-28929309
7.
Ir Med J ; 109(5): 409, 2016 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-27685880

RESUMO

Traditionally, the modified Duke's criteria, based primarily on positive blood cultures, is used to diagnose Infective Endocarditis (IE). However, reports demonstrate that 31% of cases are diagnosed as Culture Negative Infective Endocarditis (CNIE)1. Consequently, empiric broad-spectrum antibiotics are prescribed to cover unidentified organisms and, as a result, antibiotic therapy may be compromised. Molecular diagnostic techniques aid with identifying causative organisms in cases of CNIE and we question if the increasing use of such technologies will change the local epidemiology of CNIE. We present the first case of Tropheryma whipplei Infective Endocarditis (TWIE) reported in Ireland.

8.
Ir J Med Sci ; 185(4): 881-886, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26679189

RESUMO

BACKGROUND: Nystagmus in patients with multiple sclerosis (MS) is generally attributed to brainstem disease. Lesions in other regions may result in nystagmus. The identification of these other sites is enhanced by using 3-Tesla magnetic resonance imaging (3TMRI) due to increased signal-to-noise ratio. OBJECTIVE: We sought to evaluate the distribution of structural lesions and disruption of tracts in patients with horizontal nystagmus secondary to MS using 3TMRI. METHODS: Twenty-four patients (20 women, 4 men; age range 26-55 years) with horizontal nystagmus secondary to MS underwent 3TMRI brain scans; and 18 patients had diffusion tensor imaging (DTI) for tractography. RESULTS: Nystagmus was bidirectional in 11, right-sided in 6 and left-sided in 7. We identified 194 lesions in 20 regions within the neural integrator circuit in 24 patients; 140 were within the cortex and 54 were within the brainstem. Only two patients had no lesions in the cortex, and 9 had no lesions in the brainstem. There was no relationship between side of lesion and direction of nystagmus. Thirteen of 18 (72 %) had tract disruption with fractional anisotropy (FA) values below 0.2. FA was significantly lower in bidirectional compared to unidirectional nystagmus (p = 0.006). CONCLUSION: In MS patients with horizontal nystagmus, lesions in all cortical eye fields and their descending connections were evident. Technical improvements in tractography may help identify the specific site(s) resulting in nystagmus in MS.


Assuntos
Imagem de Tensor de Difusão/métodos , Imageamento por Ressonância Magnética/métodos , Esclerose Múltipla/diagnóstico por imagem , Nistagmo Patológico/diagnóstico por imagem , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
Osteoporos Int ; 26(3): 1125-35, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25311107

RESUMO

UNLABELLED: Ethnic differences in renal calcium and phosphate excretion exist, which may depend on differences in their dietary intakes and regulatory factors. We report highly significant differences in urinary calcium and phosphate excretion between white British and Gambian adults after statistical adjustment for mineral intakes, indicating an independent effect of ethnicity. INTRODUCTION: Populations vary in their risk of age-related osteoporosis. There are racial or ethnic differences in the metabolism of the bone-forming minerals calcium (Ca) and phosphate (P), with a lower renal Ca and P excretion in African-Americans compared to white counterparts, even at similar intakes and rates of absorption. Also, Africans in The Gambia have a lower Ca excretion compared to white British subjects, groups known to differ in their dietary Ca intake. Here, we report on differences in urinary Ca and P excretion between Gambian and white British adults while allowing for known predictors, including dietary intakes. METHODS: Participants were healthy white British (n = 60) and Gambian (n = 61) men and women aged 60-75 years. Fasting blood and 2-h urine samples were collected. Markers of Ca and P metabolism were analysed. Dietary intake was assessed with country-specific methods. RESULTS: White British older adults had higher creatinine-corrected urinary Ca and P excretion (uCa/uCr, uP/uCr) and lower tubular maximum of Ca and P compared to Gambian counterparts. The predictors of urinary Ca and P differed between groups. Multiple regression analysis showed that dietary Ca and Ca/P were predictors of uCa/uCr and uP/uCr, respectively. Ethnicity remained a significant predictor of uCa/uCr and uP/uCr after adjustment for diet and other factors. CONCLUSIONS: Gambian older adults have higher renal Ca conservation than British counterparts. Dietary mineral intakes were predictors of the differences in urinary Ca and P excretion, but ethnicity remained a highly significant predictor after statistical adjustment. This suggests that ethnicity has an independent effect on renal Ca and P handling.


Assuntos
Cálcio/urina , Dieta/etnologia , Alimentos , Fosfatos/urina , Idoso , Estudos Transversais , Feminino , Gâmbia/etnologia , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Reino Unido/etnologia
10.
Ann Thorac Surg ; 98(2): 756-64, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24980602

RESUMO

Cardiac surgical patients often have associated comorbidities that can impede normal wound healing; however, statin therapy has the potential to improve this process through augmentation of the normal inflammatory response. Outcomes included a 30% earlier rate of wound epithelialization and an 80% greater wound-breaking strength combined with faster wound healing rates (13.0 days vs 18.7 days, p<0.0001). Inhibition of farnesyl pyrophosphate may hold a key role in the mediation of such advantageous effects. This systematic review suggests that there is sufficient evidence to warrant completion of a human trial to assess the effects of statins on wound healing.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Cicatrização/efeitos dos fármacos , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia
11.
Proc Nutr Soc ; 73(2): 340-51, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24621477

RESUMO

The prevalence of osteoporosis and the incidence of age-related fragility fracture vary by ethnicity. There is greater than 10-fold variation in fracture probabilities between countries across the world. Mineral and bone metabolism are intimately interlinked, and both are known to exhibit patterns of daily variation, known as the diurnal rhythm (DR). Ethnic differences are described for Ca and P metabolism. The importance of these differences is described in detail between select ethnic groups, within the USA between African-Americans and White-Americans, between the Gambia and the UK and between China and the UK. Dietary Ca intake is higher in White-Americans compared with African-Americans, and is higher in White-British compared with Gambian and Chinese adults. Differences are observed also for plasma 25-hydroxy vitamin D, related to lifestyle differences, skin pigmentation and skin exposure to UVB-containing sunshine. Higher plasma 1,25-dihydroxy vitamin D and parathyroid hormone are observed in African-American compared with White-American adults. Plasma parathyroid hormone is also higher in Gambian adults and, in winter, in Chinese compared with White-British adults. There may be ethnic differences in the bone resorptive effects of parathyroid hormone, with a relative skeletal resistance to parathyroid hormone observed in some, but not all ethnic groups. Renal mineral excretion is also influenced by ethnicity; urinary Ca (uCa) and urinary P (uP) excretions are lower in African-Americans compared with White-Americans, and in Gambians compared with their White-British counterparts. Little is known about ethnic differences in the DR of Ca and P metabolism, but differences may be expected due to known differences in lifestyle factors, such as dietary intake and sleep/wake pattern. The ethnic-specific DR of Ca and P metabolism may influence the net balance of Ca and P conservation and bone remodelling. These ethnic differences in Ca, P and the bone metabolism may be important factors in the variation in skeletal health.


Assuntos
Osso e Ossos/metabolismo , Cálcio/metabolismo , Fraturas Ósseas/etnologia , Osteoporose/etnologia , Fosfatos/metabolismo , Fósforo/metabolismo , Grupos Raciais , Densidade Óssea , Etnicidade , Fraturas Ósseas/metabolismo , Humanos , Osteoporose/metabolismo , Hormônio Paratireóideo/sangue , Vitamina D/análogos & derivados , Vitamina D/sangue
12.
Ir J Med Sci ; 182(1): 29-32, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22484845

RESUMO

BACKGROUND: The effect of immunomodulator therapy (IMT) for multiple sclerosis (MS) on bone turnover is unknown. AIM: The aim of this study was to assess bone turnover in MS patients on IMT. METHODS: MS patients (n = 29) on maintenance IMT had repeat measurement of bone mineral density (BMD) after a 4.0 ± 0.4 years; bone turnover markers (BTM) were measured at the time of repeat BMD. RESULTS: BMD was unchanged at the spine but declined at the hip. BTMs, both resorption and formation, were reduced compared to normative range that may indicate an anti-resorptive action of IMT. Significant negative correlations were noted between BTMs and changes in BMD at spine but not hip. CONCLUSION: These observations suggest that IMT may have a beneficial effect on spinal bone by an antiresorptive action. A prospective study of the effect of IMT on BMD and bone turnover is warranted.


Assuntos
Conservadores da Densidade Óssea/farmacologia , Reabsorção Óssea/tratamento farmacológico , Fatores Imunológicos/farmacologia , Esclerose Múltipla/tratamento farmacológico , Doenças da Coluna Vertebral/tratamento farmacológico , Adulto , Densidade Óssea/efeitos dos fármacos , Reabsorção Óssea/complicações , Estudos de Coortes , Feminino , Cabeça do Fêmur , Quadril , Humanos , Vértebras Lombares , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/complicações , Estudos Prospectivos , Doenças da Coluna Vertebral/complicações , Coluna Vertebral/efeitos dos fármacos , Adulto Jovem
13.
Pediatr Pulmonol ; 48(8): 838-40, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22997173

RESUMO

We present the case of a 6-year-old child who presented with an episode of life threatening hemoptysis. Investigations revealed multiple areas of endobronchial varices and abnormal pleural vessels as well as severe left pulmonary vein stenosis and an atrial septal defect (ASD). After extensive work up and consultation he underwent repair of the left pulmonary vein using a sutureless technique and ASD closure. This resulted in a marked improvement in the appearances of the left lung. The bronchial varices in the right lung remain unchanged. No further hemoptysis has occurred and the child continues to be monitored.


Assuntos
Brônquios/irrigação sanguínea , Hemoptise/etiologia , Hemostasia Cirúrgica/métodos , Veias Pulmonares/cirurgia , Pneumopatia Veno-Oclusiva/complicações , Varizes/complicações , Angiografia , Biópsia , Broncoscopia , Criança , Diagnóstico Diferencial , Hemoptise/diagnóstico , Hemoptise/cirurgia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pneumopatia Veno-Oclusiva/diagnóstico , Pneumopatia Veno-Oclusiva/cirurgia , Técnicas de Sutura , Tomografia Computadorizada por Raios X , Varizes/diagnóstico , Varizes/cirurgia
14.
Ir Med J ; 105(7): 244-5, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23008886

RESUMO

A retrospective chart review was carried out at the HIV clinic in St. James's Hospital, Dublin to examine the rate of cognitive impairment through the use of surrogate markers for cognitive impairment. 500 consecutive hospital charts were reviewed. There were 306 men and 194 women. Median age was 37. The most common mode of transmission was heterosexual. 45% had a nadir CD4 < 200. 78.6% were on antiretroviral therapy and 72.26% were virally suppressed. 69/500 patients (13.8%) had one or more positive surrogate markers for cognitive impairment. The surrogate markers used were subjective complaints, a new onset of a psychiatric diagnosis post diagnosis with HIV, neurological complications and radiological evidence of atrophy. Multivariate analysis using logistic regression showed significant relationships only with gender and year of diagnosis. This figure is lower than reported international prevalence rates of cognitive impairment and demonstrates that surrogate markers are no match for structured cognitive screening. We have since commenced structured prospective screening to obtain a true prevalence of cognitive impairment in this population.


Assuntos
Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/psicologia , Infecções por HIV/psicologia , Programas de Rastreamento/métodos , Adolescente , Adulto , Idoso , Encéfalo/diagnóstico por imagem , Transtornos Cognitivos/etiologia , Feminino , Infecções por HIV/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/etiologia , Radiografia , Adulto Jovem
15.
Ir Med J ; 105(6): 183-4, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22973658

RESUMO

Lambert-Eaton myasthenic syndrome (LEMS) is a rare autoimmune disorder of neuromuscular transmission (NMJ) that shares many clinical features with myasthenia gravis (MG). We report a 73 year-old lady who presented 10 years previously with stiffness of both calves, dry mouth, fatigue, proximal weakness and areflexia in lower limbs. Neurophysiological studies were consistent with LEMS. Her work up for an underlying neoplasm was negative. She recently developed unilateral ptosis and diplopia which dramatically improved with pyridostigmine suggesting concomitant MG.


Assuntos
Síndrome Miastênica de Lambert-Eaton/epidemiologia , Miastenia Gravis/epidemiologia , Potenciais de Ação , Idoso , Inibidores da Colinesterase/uso terapêutico , Comorbidade , Feminino , Humanos , Síndrome Miastênica de Lambert-Eaton/fisiopatologia , Miastenia Gravis/tratamento farmacológico , Brometo de Piridostigmina/uso terapêutico
16.
Surgeon ; 10(4): 206-10, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22818278

RESUMO

BACKGROUND: Management of patients with severe concomitant carotid and coronary disease remains controversial. We report our experience of combined carotid endarterectomy (CEA) and coronary artery bypass surgery (CABG) over a fifteen year period using strict patient selection criteria. METHODS: From 1st January 1995 to December 31st 2009 165 patients underwent combined CABG/CEA procedures at the Mater Hospital. Mean age was 68.2 years (range 43-88) and 127 (77%) were male. Fifty-three (32%) had symptomatic carotid disease. Indications for combined procedures were the presence of symptomatic >70% or asymptomatic >80% internal carotid artery stenosis in a patient requiring urgent CABG because of either unstable angina, recent MI, severe triple vessel disease or severe Left Anterior Descending or Left Main Stem stenosis. RESULTS: Thirty-day stroke and death rate was 3%. All neurological events were in the hemisphere contralateral to the carotid surgery and symptoms had completely resolved prior to discharge from hospital. One patient required evacuation of a cervical haematoma and there were two transient XII nerve palsies. CONCLUSION: Combined CEA/CABG can be performed safely with acceptable morbidity and mortality in patients selected in accordance with strict criteria in a centre with a large experience of both cardiac and carotid surgery.


Assuntos
Estenose das Carótidas/cirurgia , Ponte de Artéria Coronária/métodos , Doença da Artéria Coronariana/cirurgia , Endarterectomia das Carótidas/métodos , Seleção de Pacientes , Adulto , Idoso , Idoso de 80 Anos ou mais , Estenose das Carótidas/complicações , Doença da Artéria Coronariana/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
18.
Int J STD AIDS ; 23(2): 145-6, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22422694

RESUMO

We present the case of a 48-year-old HIV-positive man, who developed acute onset of pain in both upper limbs associated with proximal weakness and distal paraesthesia. Eight weeks prior to this presentation he had had varicella zoster affecting his right S1 dermatome. CD4 count was 355 cells/mm(3) and he was antiretroviral therapy (ART) naive. Power was 0/5 proximally and 4/5 distally in the upper limbs. Reflexes were absent and there was sensory loss in the C5, C6 and T1 dermatomes. Cerebrospinal fluid (CSF) examination showed a lymphocytosis with low glucose; however, CSF Mycobacterium tuberculosis (TB), and herpes simplex virus polymerase chain reaction (HSV PCR) were negative as was syphilis serology. Electromyography showed marked motor axonal loss. Magnetic resonance imaging (MRI) did not show any cervical spinal lesion. Varicella zoster virus (VZV) PCR was positive in the CSF. He was treated with high-dose intravenous aciclovir with good resolution of his syndrome over time and was commenced on ART. We believe this to be the first case report of varicella reactivation causing bilateral neuralgic amyotrophy in an HIV-positive patient.


Assuntos
Neurite do Plexo Braquial/virologia , Varicela/patologia , Infecções por HIV/patologia , Infecções por HIV/virologia , Aciclovir/uso terapêutico , Antivirais/uso terapêutico , Neurite do Plexo Braquial/fisiopatologia , Varicela/tratamento farmacológico , Herpesvirus Humano 3/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Ativação Viral
20.
Circulation ; 124(11 Suppl): S168-73, 2011 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-21911808

RESUMO

BACKGROUND: The sequelae of aortic root dilation are the lethal consequences of Marfan syndrome. The root dilation is attributable to an imbalance between deposition of matrix elements and metalloproteinases in the aortic medial layer as a result of excessive transforming growth factor-beta signaling. This study examined the efficacy and mechanism of statins in attenuating aortic root dilation in Marfan syndrome and compared effects to the other main proposed preventative agent, losartan. METHODS AND RESULTS: Marfan mice heterozygous for a mutant allele encoding a cysteine substitution in fibrillin-1 (C1039G) were treated daily from 6 weeks old with pravastatin 0.5 g/L or losartan 0.6 g/L. The end points of aortic root diameter (n=25), aortic thickness, and architecture (n=10), elastin volume (n=5), dp/dtmax (maximal rate of change of pressure) (cardiac catheter; n=20), and ultrastructural analysis with stereology (electron microscopy; n=5) were examined. The aortic root diameters of untreated Marfan mice were significantly increased in comparison to normal mice (0.161 ± 0.001 cm vs 0.252 ± 0.004 cm; P<0.01). Pravastatin (0.22 ± 0.003 cm; P<0.01) and losartan (0.221 ± 0.004 cm; P<0.01) produced a significant reduction in aortic root dilation. Both drugs also preserved elastin volume within the medial layer (pravastatin 0.23 ± 0.02 and losartan 0.29 ± 0.03 vs untreated Marfan 0.19 ± 0.02; P=0.01; normal mice 0.27 ± 0.02). Ultrastructural analysis showed a reduction of rough endoplasmic reticulum in smooth muscle cells with pravastatin (0.022 ± 0.004) and losartan (0.013 ± 0.001) compared to untreated Marfan mice (0.035 ± 0.004; P<0.01). CONCLUSIONS: Statins are similar to losartan in attenuating aortic root dilation in a mouse model of Marfan syndrome. They appear to act through reducing the excessive protein manufacture by vascular smooth muscle cells, which occurs in the Marfan aorta. As a drug that is relatively well-tolerated for long-term use, it may be useful clinically.


Assuntos
Doenças da Aorta/etiologia , Doenças da Aorta/prevenção & controle , Dilatação Patológica/etiologia , Dilatação Patológica/prevenção & controle , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Síndrome de Marfan/complicações , Pravastatina/uso terapêutico , Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Animais , Aorta/metabolismo , Aorta/patologia , Doenças da Aorta/metabolismo , Dilatação Patológica/metabolismo , Modelos Animais de Doenças , Elastina/metabolismo , Retículo Endoplasmático/ultraestrutura , Losartan/uso terapêutico , Masculino , Camundongos , Camundongos Mutantes , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Músculo Liso Vascular/ultraestrutura , Resultado do Tratamento , Túnica Média/metabolismo , Túnica Média/patologia
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