Contributo dos músculos respiratórios para a fisiopatologia da hipercápnia na doença pulmonar crónica estabilizada : parte 3 = The role of the respiratory muscles in the pathophisiology of chronic hypercapnia in clinically stable chronic obstructive pulmonary diseases: part 3

Rev Port Pneumol. VII(2): 234-250, 2001

Contributo dos músculos respiratórios para a fisiopatologia da hipercápnia na doença pulmonar crónica estabilizada : parte 4 = The role of the respiratory muscles in the pathophisiology of chronic hypercapnia in clinically stable chronic obstructive pulmonary diseases: part 4

Rev Port Pneumol. VII(2): 251-263, 2001

Ocorrência de ouro nos depósitos pliocénicos da região de Cruz de Pau (Seixal)

Recently had been discovery, in the area of the construction of the Carla Sacramento Athletics Stadium at Cruz de Pau (Seixal), a set of stopes and wells with characteristics of ancient Roman mining activities. The old mining works are incised in pliocene sandy formations with conglomeratic facies, where four preliminary samples were collected in a coarser level with subrounded pebbles. The heavy minerais of those samples were studied in accordance with the Heavy Mineral Concentrate Laboratory of the IGM. The previously mentioned facies has interesting gold percentages and the presence of grey (nodular) and classic monazite, xenotime, cassiterite, spinels s.l., ilmenite and rutile. The morphology of the gold grains as well as the heavy minerals shows two phases of transport; an initial fluvial phase and a secondary aeolian phase influenced their concentracion. The high percentage of toroid grains showing evidence of wind ablation, suggests that this was the main factor for reconcentration of the gold. The amount of gold particles obtained in the concentrates is considerable and in one sample, a grade of 3.2 ppm was calculated. The samples also have been analysed for Au + 34 elements by INAA and ICP-MS, the results of which show similar grades as previously obtained.

Glass in Cultural Heritage – An Introduction

Proceedings of the Chemistry and Conservation Science

Effects of Acute Autonomic Modulation on Atrial Conduction Delay and Local Electrograms Duration in Paroxysmal Atrial Fibrillation

Slowed atrial conduction may contribute to reentry circuits and vulnerability for atrial fibrillation (AF). The autonomic nervous system (ANS) has modulating effects on electrophysiological properties. However, complex interactions of the ANS with the arrhythmogenic substrate make it difficult to understand the mechanisms underlying induction and maintenance of AF. AIM: To determine the effect of acute ANS modulation in atrial activation times in patients (P) with paroxysmal AF (PAF). METHODS AND RESULTS: 16P (9 men; 59±14years) with PAF, who underwent electrophysiological study before AF ablation, and 15P (7 men; 58±11years) with atrioventricular nodal reentry tachycardia, without documentation or induction of AF (control group). Each group included 7P with arterial hypertension but without underlying structural heart disease. The study was performed while off drugs. Multipolar catheters were placed at the high right atrium (HRA), right atrial appendage (RAA), coronary sinus (CS) and His bundle area (His). At baseline and with HRA pacing (600ms, shortest propagated S2) we measured: i) intra-atrial conduction time (IACT, between RAA and atrial deflection in the distal His), ii) inter-atrial conduction time (interACT, between RAA and distal CS), iii) left atrial activation time (LAAT, between atrial deflection in the distal His and distal CS), iv) bipolar electrogram duration at four atrial sites (RAA, His, proximal and distal CS). In the PAF group, measurements were also determined during handgrip and carotid sinus massage (CSM), and after pharmacological blockade of the ANS (ANSB). AF was induced by HRA programmed stimulation in 56% (self-limited - 6; sustained - 3), 68.8% (self-limited - 6; sustained - 5), and 50% (self-limited - 5; sustained - 3) of the P, in basal, during ANS maneuvers, and after ANSB, respectively (p=NS). IACT, interACT and LAAT significantly lengthened during HRA pacing in both groups (600ms, S2). P with PAF have longer IACT (p<0.05), a higher increase in both IACT, interACT (p<0.01) and electrograms duration (p<0.05) with S2, and more fragmented activity, compared with the control group. Atrial conduction times and electrograms duration were not significantly changed during ANS stimulation. Nevertheless, ANS maneuvers increased heterogeneity of the local electrograms duration. Also, P with sustained AF showed longer interACT and LAAT during CSM. CONCLUSION: Atrial conduction times, electrograms duration and fractionated activity are increased in PAF, suggesting a role for conduction delays in the arrhythmogenic substrate. Acute vagal stimulation is associated with prolonged interACT and LAAT in P with inducible sustained AF and ANS modulation may influence the heterogeneity of atrial electrograms duration.

Upper Eyelid Reconstruction With a Horizontal V-Y Myotarsocutaneous Advancement Flap

Upper eyelid tumours, particularly basal cell carcinomas, are relatively frequent. Surgical ablation of these lesions creates defects of variable complexity. Although several options are available for lower eyelid reconstruction, fewer surgical alternatives exist for upper eyelid reconstruction. Large defects of this region are usually reconstructed with two-step procedures. In 1997, Okada et al. described a horizontal V-Y myotarsocutaneous advancement flap for reconstruction of a large upper eyelid defect in a single operative time. However, no further studies were published regarding the use of this particular flap in upper eyelid reconstruction. In addition, this flap is not described in most plastic surgery textbooks. The authors report here their experience of 16 cases of horizontal V-Y myotarsocutaneous advancement flaps used to reconstruct full-thickness defects of the upper eyelid after tumour excision. The tumour histological types were as follows: 12 basal cell carcinomas, 2 cases of squamous cell carcinomas, 1 case of sebaceous cell carcinoma and 1 of malignant melanoma. This technique allowed closure of defects of up to 60% of the eyelid width. None of the flaps suffered necrosis. The mean operative time was 30 min. No additional procedures were necessary as good functional and cosmetic results were achieved in all cases. No recurrences were noted. In this series, the horizontal V-Y myotarsocutaneous advancement flap proved to be a technically simple, reliable and expeditious option for reconstruction of full-thickness upper eyelid defects (as wide as 60% of the eyelid width) in a single operative procedure. In the future this technique may become the preferential option for such defects.

Regulação integrada do metabolismo da glucose no estado pós-prandial : fisiologia e reversão de processos patológicos

Resumo: Os mecanismos que regulam a homeostase da glucose no pós-prandial são distintos dos mecanismos desencadeados em situações de jejum. Desta forma o fígado parece desempenhar um papel fundamental na acção periférica da insulina após a refeição através de um mecanismo que envolve os nervos parassimpáticos hepáticos e o óxido nítrico (NO). Esta dissertação procura evidenciar a importância de ambos na fi siologia de manutenção da glicémia pós-prandial e na fi siopatologia da resistência à insulina. Dos resultados obtidos observou-se que após a administração de uma refeição mista o perfi l glicémico foi distinto em animais com ou sem ablação dos nervos parassimpáticos hepáticos. A desnervação parassimpática hepática aumentou as excursões de glucose imediatamente após a refeição. Estas diferenças nas excursões de glucose dependentes do parassimpático ocorreram devido a uma diminuição da clearance de glucose, sem que fosse afectada a taxa de aparecimento de glucose no sangue, a produção endógena de glucose e secreção de insulina ou péptido-C. Este aumento das excursões de glucose revelou-se ser devida à diminuição da clearance de glucose pós-prandial exclusivamente no músculo-esquelético, coração e o rim. Concluiu-se que o fígado teria uma função endócrina nestes três órgãos. Surgiu assim a hipótese dos S-nitrosotiois (RSNOs) poderem mimetizar essa resposta endócrina. Testou-se o seu efeito in vivo na sensibilidade à insulina. Para níveis baixos de sensibilidade à insulina, como jejum, desnervação no estado pós-prandial e resistência à insulina os RSNOs potenciaram a sensibilidade à insulina para valores semelhantes ao pós-prandial indicando-os como potenciais fármacos no tratamento da resistência à insulina. O NO e seus derivados ganharam assim uma evidência cada vez maior na acção periférica da insulina e portanto fez-se uma caracterização dos seus níveis desde a fi siologia à fi siopatologia. Os resultados obtidos nesta dissertação permitiram correlacionar a sintetase de óxido nítrico (NOS), enzima responsável pela síntese de NO como um possível marcador da resistência à insulina. Os resultados obtidos contribuíram substancialmente para compreender os mecanismos fi siológicos e fi siopatológicos de manutenção da glicémia após a refeição, colocando o fígado como órgão primordial na regulação periférica (extra-hepática) da captação de glucose.-------- ABSTRACT: The mechanisms responsible for the postprandial response are different from the ones in the fasted state. Therefore the liver seems to play a fundamental role in postprandial insulin action through a mechanism that evolves the hepatic parasympathetic nerves (HPN) and nitric oxide (NO). This work focused on the importance of both, HPN and NO, on postprandial glycemic control and on the pathophysiology of insulin resistance. We observed that after administration of a mixed meal the glycemic profi les with or without the parasympathetic nerves were distinct, increasing glucose excursions after ablation of HPN.This increase in glucose excursions was due to a decrease on the rate of glucose disappearance in extra-hepatic tissues. Glucose appearance rate, endogenous glucose production and insulin secretion were not related to this mechanism. The increase on glucose excursions after the ablation of hepatic parasympathetic system was due to a decrease on glucose clearance on extra-hepatic tissues, namely skeletal-muscle, heart and kidney. We concluded that the liver has an endocrine function on those tissues increasing their glucose uptake.This mechanism led to propose the hypothesis that S-nitrosothiols (RSNOs) could mimic this mechanism. Therefore RSNOs effects on insulin sensitivity were tested. For low insulin sensitivity levels, i.e. fasted state, ablation of the HPN or insulin resistance state induced by a high sucrose diet RSNOs increased insulin sensitivity to levels normally observed in the postprandial state. These results indicated these drugs as potential pharmacological tools in the treatment of insulin resistance. NO and their derivates emerged as fundamental parts of insulin action. A characterization of nitric oxide and nitric oxide synthase (NOS), the enzyme responsible for NO synthesis was part of the work performed. We concluded that NO could be used as a biomarker for insulin resistance states. This work contributed for understanding the mechanism underlying postprandial glycemic control indicating the liver as a key organ in the regulation of peripheral (extra-hepatic) insulin action.

Analysis of Synaptic Proteins in the Cerebrospinal Fluid as a New Tool in the Study of Inborn Errors of Neurotransmission

Abstract In a few rare diseases, specialised studies in cerebrospinal fluid (CSF) are required to identify the underlying metabolic disorder. We aimed to explore the possibility of detecting key synaptic proteins in the CSF, in particular dopaminergic and gabaergic, as new procedures that could be useful for both pathophysiological and diagnostic purposes in investigation of inherited disorders of neurotransmission. Dopamine receptor type 2 (D2R), dopamine transporter (DAT) and vesicular monoamine transporter type 2 (VMAT2) were analysed in CSF samplesfrom 30 healthy controls (11 days to 17 years) by western blot analysis. Because VMAT2 was the only protein with intracellular localisation, and in order to compare results, GABA vesicular transporter, which is another intracellular protein, was also studied. Spearman’s correlation and Student’s t tests were applied to compare optical density signals between different proteins. All these synaptic proteins could be easily detected and quantified in the CSF. DAT, D2R and GABA VT expression decrease with age, particularly in the first months of life, reflecting the expected intense synaptic activity and neuronal circuitry formation. A statistically significant relationship was found between D2R and DAT expression, reinforcing the previous evidence of DAT regulation by D2R. To our knowledge, there are no previous studies on human CSF reporting a reliable analysis of these proteins. These kinds of studies could help elucidate new causes of disturbed dopaminergic and gabaergic transmission as well as understanding different responses to L-dopa in inherited disorders affecting dopamine metabolism. Moreover, this approach to synaptic activity in vivo can be extended to different groups of proteins and diseases.

National Registry on Cardiac Electrophysiology (2012)

Based on a survey sent to Portuguese centers that perform diagnostic and interventional electrophysiology and/or implantable cardioverter-defibrillator (ICD) implantations, the authors analyze the number and type of procedures performed during 2012 and compare these data with previous years. In 2012, a total of 2561 diagnostic electrophysiologic studies were performed, which were followed by ablation in 2017 cases, representing a steady situation compared with the previous year. There was a 12% increase in the number of ablation procedures for atrial fibrillation, making it for the first time the most frequent indication for ablation, overtaking atrioventricular nodal reentrant tachycardia. The total number of first ICD implantations was 1048 (around 100 per million population), of which 375 were cardiac resynchronization devices (BiV ICDs). This represents a slight decrease (3.3%) in the total number of new implants, with an increase of 10% in the number of BiV ICDs compared to the previous year. However, there was a considerable increase in the number of ICD generator replacements, resulting in an overall increase of 3.5% in implantations performed in 2012. Some comments are made regarding developments in this activity and its current status, and on some factors that may influence the dynamics of this area of interventional cardiology.

Short QT Syndrome Presenting As Syncope: How Short Is Too Short?

We report the case of a 52-year-old man who presented to our emergency department (ED) after three episodes of syncope in the seven hours before admission. During his stay in the ED he had recurrent ventricular tachycardia (VT) requiring external electrical cardioversion. A 12-lead electrocardiogram (ECG) showed a short QT (SQT) interval (270 ms, QTc 327 ms), with frequent R-on-T extrasystoles triggering sustained polymorphic VT. After exclusion of other precipitating causes, the patient was diagnosed as having SQT syndrome (SQTS) according to the Gollob criteria. To our knowledge, this is the first known documentation of an SQT-caused arrhythmic episode on a 12-lead ECG, as well as the first reported case of SQTS in Portugal. The patient received an implantable cardioverter-defibrillator and was discharged. At a follow-up assessment 14 months later he was symptom-free, interrogation of the device showed no arrhythmic events, and the ECG showed a QT interval of 320 ms (QTc 347 ms).

The Proarrhythmic Effect of Cardiac Resynchronization Therapy: an Issue that Should Be Borne in Mind

The demonstrated benefits of cardiac resynchronization therapy (CRT) in reducing mortality and hospitalizations for heart failure, improving NYHA functional class and inducing reverse remodeling have led to its increasing use in clinical practice. However, its potential contribution to complex ventricular arrhythmias is controversial.We present the case of a female patient with valvular heart failure and severe systolic dysfunction, in NYHA class III and under optimal medical therapy, without previous documented ventricular arrhythmias. After implantation of a CRT defibrillator, she suffered an arrhythmic storm with multiple episodes of monomorphic ventricular tachycardia (VT), requiring 12 shocks. Subsequently, a pattern of ventricular bigeminy was observed, as well as reproducible VT runs induced by biventricular pacing. Since no other vein of the coronary sinus system was accessible, it was decided to implant an epicardial lead to stimulate the left ventricle, positioned in the left ventricular mid-lateral wall. No arrhythmias were detected in the following six months. This case highlights the possible proarrhythmic effect of biventricular pacing with a left ventricular lead positioned in the coronary sinus venous system.

Transístores de efeito de campo de silício cristalino obtidos pelo método de pré-deposição de dopante a baixa temperatura

Dissertação para obtenção do Grau de Mestre em Engenharia de Materiais

Role of sympathetic innervation in obesity

Part of the results presented in this thesis were published in the following reference (DOI 10.1016/j.cell.2015.08.055): Wenwen Zeng*, Roksana M. Pirzgalska*, Mafalda M.A. Pereira, Nadiya Kubasova, Andreia Barateiro, Elsa Seixas, Yi-Hsueh Lu, Albina Kozlova, Henning Voss, Gabriel G. Martins, Jeffrey M. Friedman and Ana I. Domingos. Sympathetic Neuro-adipose Connections Mediate Leptin-Driven Lipolysis. Cell 163, 84-94 (2015). The work was also presented through poster presentations at iMED Conference 6.0 (Lisbon, 2014), Sociedade Portuguesa de Bioquímica Meeting (Coimbra, 2014) and Sociedade Portuguesa de Neurociências Meeting (Póvoa de Varzim, 2015).

Ventricular arrhythmias in Chagas disease

Sudden death is one of the most characteristic phenomena of Chagas disease, and approximately one-third of infected patients develop life-threatening heart disease, including malignant ventricular arrhythmias. Fibrotic lesions secondary to chronic cardiomyopathy produce arrhythmogenic substrates that lead to the appearance and maintenance of ventricular arrhythmias. The objective of this study is to discuss the main clinical and epidemiological aspects of ventricular arrhythmias in Chagas disease, the specific workups and treatments for these abnormalities, and the breakthroughs needed to determine a more effective approach to these arrhythmias. A literature review was performed via a search of the PubMed database from 1965 to May 31, 2014 for studies of patients with Chagas disease. Clinical management of patients with chronic Chagas disease begins with proper clinical stratification and the identification of individuals at a higher risk of sudden cardiac death. Once a patient develops malignant ventricular arrhythmia, the therapeutic approach aims to prevent the recurrence of arrhythmias and sudden cardiac death by the use of implantable cardioverter defibrillators, antiarrhythmic drugs, or both. In select cases, invasive ablation of the reentrant circuit causing tachycardia may be useful. Ventricular arrhythmias are important manifestations of Chagas cardiomyopathy. This review highlights the absence of high-quality evidence regarding the treatment of ventricular arrhythmias in Chagas disease. Recognizing high-risk patients who require specific therapies, especially invasive procedures such as the implantation of cardioverter defibrillators and ablative approaches, is a major challenge in clinical practice.

Conteúdo em Polifenóis totais do vinho em contacto com aparas de madeira e subsequentes características colorimétricas

Neste trabalho fez-se o estudo do conteúdo de polifenóis totais (PT) por reação de Folin-Ciocalteau e das características colorimétricas por espetrofotometria e colorimetria de dois tipos de vinho: branco (Vb) e tinto (Vt) e o estudo evolutivo das mesmas características em soluções hidroalcoólicas (SH), miméticas ao vinho em teor alcoólico e pH. Tanto os vinhos como as soluções estiveram em contacto com vários tipos de espécies botânicas com potencial interesse enológico: Acácia (AC), Cerejeira (CJ), Castanheiro (CT) e Carvalho (CN) em concentrações de 50 g/L, 2 g/L e 6 g/L para as SH, Vb e Vt respetivamente todas elas com quatro graus de queima e duas morfologias: aparas e dominós (apenas SH). As SH-aparas estiveram 11 dias em contacto com as madeiras onde ao final do dia 9 se registou um teor de PT de 1128 (AC), 321 (CJ), 2346 (CT) e 1815 (CN) mg GEA/L para todos com queima ligeira, à exceção de castanheiro, que obteve o máximo na madeira sem queima. Nas SH-dominós o máximo de PT registou-se em carvalho sem queima com 1897 mg GAE/L, quando em contacto com a madeira num período superior a 9 meses. O estudo dos PT nos vinhos mostrou que as madeiras são capazes de os enriquecer com este tipo de compostos registando-se um aumento máximo de 74,44 mg GAE/L e de 979,93 mg GAE/L para os Vb e Vt respetivamente. No estudo colorimétrico por espetrofotometria foram avaliados os parâmetros CIELab de todas as SH e observou-se que L* (luminosidade) tende a diminuir com o grau de queima e com o tempo para todas as madeiras. O parâmetro a* (verde/vermelho) em AC e CJ diminui com os dias e com o grau de queima representando uma diminuição da componente vermelha. O inverso é observado em CT e CN. Por fim, b* (azul/amarelo) tende a aumentar em todas as SH com os dias e a queima tornando a solução mais amarela. Comparando os vinhos com as suas testemunhas, em Vb L* e b* aumentam refletindo-se num aumento da cor amarela e a* é mantido. Nos Vt, L* diminui quando na presença das madeiras e a* e b* aumentam acrescendo a sua componente vermelha. Fez-se a avaliação de alguns voláteis das SH por GC/MS onde foram encontrados compostos com interesses organoléticos como é o caso da lactona do whisky nalgumas graus de queima para as espécies botânicas de cerejeira e carvalho.