Pulmonary malformation in transgenic mice expressing human keratinocyte growth factor in the lung.

Expression of human keratinocyte growth factor (KGF/FGF-7) was directed to epithelial cells of the developing embryonic lung of transgenic mice disrupting normal pulmonary morphogenesis during the pseudoglandular stage of development. By embryonic day 15.5(E15.5), lungs of transgenic surfactant protein C (SP-C)-KGF mice resembled those of humans with pulmonary cystadenoma. Lungs were cystic, filling the thoracic cavity, and were composed of numerous dilated saccules lined with glycogen-containing columnar epithelial cells. The normal distribution of SP-C proprotein in the distal regions of respiratory tubules was disrupted. Columnar epithelial cells lining the papillary structures stained variably and weakly for this distal respiratory cell marker. Mesenchymal components were preserved in the transgenic mouse lungs, yet the architectural relationship of the epithelium to the mesenchyme was altered. SP-C-KGF transgenic mice failed to survive gestation to term, dying before E17.5. Culturing mouse fetal lung explants in the presence of recombinant human KGF also disrupted branching morphogenesis and resulted in similar cystic malformation of the lung. Thus, it appears that precise temporal and spatial expression of KGF is likely to play a crucial role in the control of branching morphogenesis during fetal lung development.

Mapping a gene causing cerebral cavernous malformation to 7q11.2-q21.

Cerebral cavernous malformation is a common disease of the brain vasculature of unknown cause characterized by dilated thin-walled sinusoidal vessels (caverns); these lesions cause varying clinical presentations which include headache, seizure, and hemorrhagic stroke. This disorder is frequently familial, with autosomal dominant inheritance. Using a general linkage approach in two extended cavernous malformation kindreds, we have identified linkage of this trait to chromosome 7q11.2-q21. Multipoint linkage analysis yields a peak logarithm of odds (lod) score of 6.88 with zero recombination with locus D7S669 and localizes the gene to a 7-cM region in the interval between loci ELN and D7S802.

Modulation of Sarco/Endoplasmic Reticulum Ca2+-ATPase 2 (SERCA2) function by acetylation following the treatment with histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA)

Background: Acetylation and deacetylation at specific lysine (K) residues is mediated by histone acetylases (HATs) and deacetylases (HDACs), respectively. HATs and HDACs act on both histone and non-histone proteins, regulating various processes, including cardiac impulse propagation. Aim of the present work was to establish whether the function of the Ca2+ ATPase SERCA2, one of the major players in Ca2+ reuptake during excitation-contraction coupling in cardiac myocytes (CMs), could be modulated by direct K acetylation. Materials and methods: HL-1 atrial mouse cells (donated by Prof. Claycomb), zebrafish and Streptozotocin-induced diabetic rat CMs were treated with the pan-inhibitor of class I and II HDACs suberanilohydroxamic acid (SAHA) for 1.5 hour. Evaluation of SERCA2 acetylation was analyzed by co-immunoprecipitation. SERCA2 activity was measured on microsomes by pyruvate/NADH coupled reaction assay. SERCA2 mutants were obtained after cloning wild-type and mutated sequences into the pCDNA3 vector and transfected into HEK cells. Ca2+ transients in CMs (loading with Fluo3-AM, field stimulation, 0.5 Hz) and in transfected HEK cells (loading with FLUO-4, caffeine pulse) were recorded. Results: Co-Immunoprecipitation experiments performed on HL-1 cells demonstrated a significant increase in the acetylation of SERCA2 after SAHA-treatment (2.5 µM, n=3). This was associated with an increase in SERCA2 activity in microsomes obtained from HL-1 cells, after SAHA exposure (n=5). Accordingly, SAHA-treatment significantly shortened the Ca2+ reuptake time of adult zebrafish CMs. Further, SAHA 2.5 nM restored to control values the recovery time of Ca2+ transients decay in diabetic rat CMs. HDAC inhibition also improved contraction parameters, such as fraction of shortening, and increased pump activity in microsomes isolated from diabetic CMs (n=4). Notably, the K464, identified by bioinformatic tools as the most probable acetylation site on human SERCA2a, was mutated into Glutamine (Q) or Arginine (R) mimicking acetylation and deacetylation respectively. Measurements of Ca2+ transients in HEK cells revealed that the substitution of K464 with R significantly delayed the transient recovery time, thus indicating that deacetylation has a negative impact on SERCA2 function. Conclusions: Our results indicate that SERCA2 function can be improved by pro-acetylation interventions and that this mechanism of regulation is conserved among species. Therefore, the present work provides the basis to open the search for novel pharmacological tools able to specifically improve SERCA2 activity in diseases where its expression and/or function is impaired, such as diabetic cardiomyopathy.

Análise exômica em pacientes portadores de cardiomiopatia hipertrófica

A cardiomiopatia hipertrófica (CMH) é uma doença geneticamente determinada, caracterizada por hipertrofia ventricular primária, com prevalência estimada de 0.2% na população geral. Qualquer portador tem 50% de chance de transmitir esta doença para seus filhos, o que torna cada vez mais relevante a importância do estudo genético dos indivíduos acometidos e de seus familiares. Já foram descritas diversas mutações genéticas causadoras de CMH, a maioria em genes que codificam proteínas do sarcômero, e algumas mutações mais raras em genes não sarcoméricos. O objetivo desse estudo é sequenciar as regiões exônicas de genes candidatos, incluindo os principais envolvidos na hipertrofia miocárdica, utilizando o sequenciamento de nova geração (Generation Sequencing); testar a aplicabilidade e viabilidade deste sistema para identificar mutações já confirmadas e propor as prováveis novas mutações causadoras de CMH. Métodos e resultados: 66 pacientes não aparentados portadores de CMH foram estudados e submetidos à coleta de sangue para obtenção do DNA para analisar as regiões exômicas de 82 genes candidatos, utilizando a plataforma MiSeq (Illumina). Identificou-se 99 mutações provavelmente patogênicas em 54 pacientes incluídos no estudo (81,8%) relacionadas ou não a CMH, e distribuídas em 42 genes diferentes. Destas mutações 27 já haviam sido publicadas, sendo que 17 delas descritas como causadoras de CMH. Em 28 pacientes (42,4%) identificou-se mutação nos três principais genes sarcoméricos relacionados à CMH (MYH7, MYBPC3, TNNT2). Encontrou-se também um grande número de variantes não sonôminas de efeito clínico incerto e algumas mutações relacionadas a outras enfermidades. Conclusão: a análise da sequencia dos exônos de genes candidatos, demonstrou ser uma técnica promissora para o diagnóstico genético de CMH de forma mais rápida e sensível. A quantidade de dados gerados é o um fator limitante até o momento, principalmente em doenças geneticamente complexas com envolvimento de diversos genes e com sistema de bioinformática limitado.

Technologies for Anatomical and Geometric Characterization of the Corneal Structure and Anterior Segment: A Review

Corneal and anterior segment imaging techniques have become a crucial tool in the clinical practice of ophthalmology, with a great variety of applications, such as corneal curvature and pachymetric analysis, detection of ectatic corneal conditions, anatomical study of the anterior segment prior to phakic intraocular lens implantation, or densitometric analysis of the crystalline lens. From the Placido-based systems that allow only a characterization of the geometry of the anterior corneal surface to the Scheimpflug photography-based systems that provide a characterization of the cornea, anterior chamber, and crystalline lens, there is a great variety of devices with the capability of analyzing different anatomical parameters with very high precision. To date, Scheimpflug photography-based systems are the devices providing the more complete analysis of the anterior segment in a non-invasive way. More developments are required in anterior segment imaging technologies in order to improve the analysis of the crystalline lens structure as well as the ocular structures behind the iris in a non-invasive way when the pupil is not dilated.

Renovascular hypertension in a 12 month old boy: what can the radiologist do?

We report a clinical case of renovascular disease, probably linked to fibromuscular dysplasia, in a 12 months old boy with severe arterial hypertension with target-organ damage, highlighting the radiological approach. Initial investigation included renal ultrasound that showed normal sized kidneys, with normal cortical echogenicity on the right and focally increased echogenicity of the posterior aspect of the left kidney, forming a mass-like lesion. Magnetic resonance imaging excluded renal tumor, which was confirmed by ultrasound guided biopsy. A doppler ultrasonography was also performed suggesting a right renal artery stenosis and decreased flow to the posterior aspect of the left kidney. Angiography with diagnostic and therapeutic intention was performed: right renal artery stenosis was detected and transluminal ballon dilation was performed; the left renal artery bifurcated precociously and the branch that irrigated the posterior part of the kidney had a stenosis which was also successfully dilated. After the intervention good blood pressure control with antihypertensive drugs was achieved, which was not possible before the angiographic procedure. The authors underline various methods of imaging used to accurately diagnose renovascular disease and the usefulness of interventional radiology treatment for this disease in very young children.

Miocardiopatia arritmogénica do ventrículo direito : uma doença rara e um doente peculiar

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Miocardiopatia peripartum

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Miocardiopatia arritmogénica do ventrículo direito : caso clínico

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Alterações cardíacas fisiológicas em atletas : o limiar entre patológico e fisiológico

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Frequency of MELAS main mutation in a phenotype-targeted young ischemic stroke patient population

Mitochondrial diseases, predominantly mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), may occasionally underlie or coincide with ischemic stroke (IS) in young and middle-aged individuals. We searched for undiagnosed patients with MELAS in a target subpopulation of unselected young IS patients enrolled in the Stroke in Young Fabry Patients study (sifap1). Among the 3291 IS patients aged 18-55 years recruited to the sifap1 study at 47 centers across 14 European countries, we identified potential MELAS patients with the following phenotypic features: (a) diagnosed cardiomyopathy or (b) presence of two of the three following findings: migraine, short stature (≤165 cm for males; ≤155 cm for females), and diabetes. Identified patients' blood samples underwent analysis of the common MELAS mutation, m.3243A>G in the MTTL1 gene of mitochondrial DNA. Clinical and cerebral MRI features of the mutation carriers were reviewed. We analyzed blood samples of 238 patients (177 with cardiomyopathy) leading to identification of four previously unrecognized MELAS main mutation carrier-patients. Their clinical and MRI characteristics were within the expectation for common IS patients except for severe hearing loss in one patient and hyperintensity of the pulvinar thalami on T1-weighted MRI in another one. Genetic testing for the m.3243A>G MELAS mutation in young patients with IS based on phenotypes suggestive of mitochondrial disease identifies previously unrecognized carriers of MELAS main mutation, but does not prove MELAS as the putative cause.

Retrospective study on structural neuroimaging in first-episode psychosis

Background. No consensus between guidelines exists regarding neuroimaging in firstepisode psychosis. The purpose of this study is to assess anomalies found in structural neuroimaging exams (brain computed tomography (CT) and magnetic resonance imaging (MRI)) in the initial medical work-up of patients presenting first-episode psychosis. Methods. The study subjects were 32 patients aged 18–48 years (mean age: 29.6 years), consecutively admitted with first-episode psychosis diagnosis. Socio-demographic and clinical data and neuroimaging exams (CT and MRI) were retrospectively studied. Diagnostic assessments were made using the Operational Criteria Checklist +. Neuroimaging images (CT and MRI) and respective reports were analysed by an experienced consultant psychiatrist. Results. None of the patients had abnormalities in neuroimaging exams responsible for psychotic symptoms. Thirty-seven percent of patients had incidental brain findings not causally related to the psychosis (brain atrophy, arachnoid cyst, asymmetric lateral ventricles, dilated lateral ventricles, plagiocephaly and falx cerebri calcification). No further medical referral was needed for any of these patients. No significant differences regarding gender, age, diagnosis, duration of untreated psychosis, in-stay and cannabis use were found between patients who had neuroimaging abnormalities versus those without. Discussion. This study suggests that structural neuroimaging exams reveal scarce abnormalities in young patients with first-episode psychosis. Structural neuroimaging is especially useful in first-episode psychosis patients with neurological symptoms, atypical clinical picture and old age.

Pulmonary hypoplasia and anasarca syndrome in Cika cattle

BACKGROUND: Hydrops foetalis is defined as excessive fluid accumulation within the foetal extravascular compartments and body cavities. It has been described in human and veterinary medicine, but despite several descriptive studies its aetiology is still not fully clarified. Pulmonary hypoplasia and anasarca (PHA) syndrome is a rare congenital abnormality in cattle that is characterised by hydrops foetalis including extreme subcutaneous oedema (anasarca) and undeveloped or poorly formed lungs (pulmonary hypoplasia). Until now, sporadic cases of PHA were reported in cattle breeds like Australian Dexter, Belted Galloway, Maine-Anjou, and Shorthorn. This report describes the first known cases of PHA syndrome in Slovenian Cika cattle. CASE PRESENTATION: A 13-year-old cow aborted a male calf in the seventh month of pregnancy, while a male calf was delivered by caesarean section on the due date from a 14-year-old cow. The pedigree analysis showed that the calves were sired by the same bull, the dams were paternal half-sisters and the second calf was the product of a dam-son mating. Gross lesions were similar in both cases and characterized by severe anasarca, hydrothorax, hydropericardium, ascites, hypoplastic lungs, absence of lymph nodes, and an enlarged heart. The first calf was also athymic. Histopathology of the second affected calf confirmed severe oedema of the subcutis and interstitium of the organs, and pulmonary hypoplasia. The lymph vessels in the subcutis and other organs were severely dilated. Histopathology of the second calf revealed also lack of bronchus associated lymphoid tissue and adrenal gland hypoplasia. CONCLUSIONS: The findings were consistent with known forms of the bovine PHA syndrome. This is the first report of the PHA syndrome occurring in the local endangered breed of Cika cattle. Observed inbreeding practice supports that this lethal defect most likely follows an autosomal recessive mode of inheritance. In the light of the disease phenotype it is assumed that a mutation causing an impaired development of lymph vessels is responsible for the hydrops foetalis associated malformations in bovine PHA.

Surgical cryoablation for ventricular tachyarrhythmia arising from the left ventricular outflow tract region.

BACKGROUND Ventricular arrhythmias (VAs) from the left ventricular outflow tract (LVOT) region can be inaccessible for ablation because of epicardial fat or overlying coronary arteries. OBJECTIVE We describe surgical cryoablation of this type of VA. METHODS From March 2009 to 2014, 190 consecutive patients with VAs originating from the LVOT underwent ablation at our institution. Four patients (2%) underwent surgical cryoablation for highly symptomatic VAs after failing catheter ablation. RESULTS In all patients, endocardial or percutaneous epicardial mapping was consistent with origin in the LVOT. In 2 patients, the points of earliest activation during VAs were marked with a bipolar pacing lead in the overlying cardiac vein for guidance during surgery. Surgical cryoablation was successful in 3 of the 4 patients. The fourth patient subsequently had successful endocardial catheter ablation. During a mean follow-up of 22 ± 16 months (range 4-42 months), all patients showed abolition of or marked reduction in symptomatic VA. However, 1 patient subsequently required percutaneous intervention to the left anterior descending coronary artery; another developed progressive left ventricular systolic dysfunction caused by nonischemic cardiomyopathy; and a third patient underwent permanent pacemaker implantation because of complete atrioventricular block after concomitant aortic valve replacement. CONCLUSION Surgical cryoablation is an option for highly symptomatic drug-resistant VAs emanating from the LVOT region. Despite extensive preoperative mapping, the procedure is not effective for all patients, and coronary injury is a risk.

Ablation of ischemic ventricular tachycardia: evidence, techniques, results, and future directions

PURPOSE OF REVIEW This article summarizes current understanding of the arrhythmia substrate and effect of catheter ablation for infarct-related ventricular tachycardia, focusing on recent findings. RECENT FINDINGS Clinical studies support the use of catheter ablation earlier in the course of ischemic disease with moderate success in reducing arrhythmia recurrence and shocks from implantable defibrillators, although mortality remains unchanged. Ablation can be lifesaving for patients presenting with electrical storm. Advanced mapping systems with image integration facilitate identification of potential substrate, and several different approaches to manage hemodynamically unstable ventricular tachycardia have emerged. Novel ablation techniques that allow deeper lesion formation are in development. SUMMARY Catheter ablation is an important therapeutic option for preventing or reducing episodes of ventricular tachycardia in patients with ischemic cardiomyopathy. Present technologies allow successful ablation in the majority of patients, even when the arrhythmia is hemodynamically unstable. Failure of the procedure is often because of anatomic challenges that will hopefully be addressed with technological progress.