Hepatic parasympathetic nerve dysfunction involved in the deregulation of postprandial whole-body insulin sensitivity:a road to diabetes and associated pathologies

FCM: UC Fisiologia - Teses de Doutoramento

A quest for the right word enhancing reflexivity and technology in terminology training

INTED2010, the 4th International Technology, Education and Development Conference was held in Valencia (Spain), on March 8, 9 and 10, 2010.

Pathology of periportal fibrosis involution in human schistosomiasis

Optical and electron microscopical evidences of focal matrix degradation were frequently seen in liver sections of periportal fibrosis caused by schistosomiasis mansoni in man. The material came from 14 wedge hepatic biopsies taken from patients with chronic advanced hepatosplenic disease and undergoing operations for the relief of portal hypertension. Besides the presence of focal areas of rarefaction, fragmentation and dispersion of collagen fibers, the enlarged portal spaces also showed hyperplasia of elastic tissue and disarray of smooth muscle fibers following destruction of portal vein branches. Eggs were scanty in the tissue sections, and matrix degradation probably represented involuting changes related to the progressive diminution of parasite-related aggression, which occurs spontaneously with age or after cure by chemotherapy. The changes indicative of matrix degradation now described are probably the basic morphological counterpart of periportal fibrosis involution currently being documented by ultrasonography in hepatosplenic patients submitted to curative chemotherapy.

Caracterização mineralógica da sequência sedimentar Ha7 do Cretácico Inferior do Guincho (Bacia Lusitaniana) (*)

Mineralogical assemblages, specially clay mineral assemblages, have been widely used in multidisciplinary stratigraphical studies. This paper presents the results obtained in the study of a Lower Cretaceous depositional sequence from the Lusitanian Basin (Portugal). The Upper Hauterivian – Lower Barremian section at Guincho Fort pertains mostly to the Ha7 3rd order depositional sequence defined by J. REY & al. (2003) and has been studied in a detailed bed-by-bed sampling corresponding to a total of 85 samples. The analysis of the obtained clay mineral assemblages has contributed to the paleoenvironmental and paleogeographical reconstruction of the studied interval and has improved the sequence stratigraphic interpretation and positioning of sequence boundaries and other sequential surfaces (transgressive and flooding surfaces).

Mediterranean spotted fever and identification of new agents of rickettsioses in Portugal : epidemiological determinants, host and microbial features in portuguese patients

Resumo: a febre botonosa, também conhecida por febre escaro-nodular (FEN) é uma doença endémica nos Países da bacia do Mediterrâneo, África, Médio Oriente, Índia e Paquistão. O agente etiológico responsável por esta patologia é a bactéria Rickettsia conorii. Contudo, em alguns países, como Portugal e Itália, esta patologia é causada por duas estirpes diferentes: R conorii Malish e R conorii Israeli spotted fever strain. O principal vector e reservatório é o ixodídeo Rhipicephalus sanguineus. Mesmo com uma elevada taxa de subnotificação detectada no nosso País, a taxa incidência da FEN é de 8.4/105 habitantes (1989-2005), uma das mais altas quando comparada coom a de outros países da bacia do Mediterrâneo. De todos os distritos portugueses, Bragança e Beja são aqueles que apresentam as taxas de incidência mais elevadas, 56,8/105 habitantes e 47,4 / 105 habitantes respectivamente. Em Portugal, as alterações climáticas verificadas na última década, nomeadamente a subida das temperaturas médias anuais, parecem ter influenciado o ciclo de vida do vector e a sua dinâmica sazonal, permitindo ao R. sanguineus completar mais de um ciclo de vida por ano. Este facto, e a possibilidade deste vector se manter activo noutros meses do ano, nomeadamente nos meses de inverno, tem influenciado consequentemente o padrão de distribuição anual dos casos de FEN. A febre escaro-nodular caracteriza-se clinicamente como uma doença exantemática, com um processo de vasculite generalizado. Apesar de na generalidade ser considerada uma doença benigna (quando tratada atempadamente e com terapêutica adequada e específica)e de estarem descritos casos graves em cerca de 5-6% dos doentes, em Portugal essa percentagem aumentou e consequentemente levou a um aumento de casos fatais. Este facto tornou-se mais evidente em 1997, no Hospital Distrital de Beja e no Hospital Garcia de Orta, onde a taxa de letalidade atingiu os 32% e 18% respectivamente.Para além dos factores de co-morbilidade encontrados nos doentes mais graves, como diabetes mellitus, ou o atraso na instituição da terapêutica específica, foi colocada de que a estirpe R. conorii Israel spotted fever strain pudesse ser mais virulenta ou então estivesse associada a diferentes manifestações clínicas que dificultassem o diagnóstico clínico e a instituição atempada da terapêutica. Houve ainda a necessidade de avaliar alguns parâmetros imunológicos dos doentes e tentar identificar que factores, nomeadamente que citoquinas, poderiam estar envolvidos na resposta a uma infecção por R.conorii.Face a estas questões foi avaliada e comparada a epidemiologia, manifestações clínicas e laboratoriais de 140 doentes (71 infectados com R. conorii Malish e 69 infectados com R. conorii Israel spotted fever strain). Concluiu-se que existe uma sobreposição de manifestações clinicas entre os dois grupos de doentes, mas que a percentagem da escara de inoculação é significativamente inferior em doentes infectados com R. conorii Israel spotted fever strain. Dos resultados mais importantes encontrados neste estudo concluiu-se que a estirpe R. conorii Malish e é demonstrado, pela primeira vez, estatisticamente que o alcoolismo é um factor de risco para a morte de doentes com FEN. Associadas a factores de um mau prognósitco da doença, estão as manifestações gastrointestinais, que poderão ser ou não reflexo de alterações do sistema nervoso central, e ainda a alteração de parâmetros laboratoriais como a presença de hiperbilirubinemia e aumento dos valores da ureia.A maior parte dos estudos realizados sobre os mecanismos da resposta imunitária à infecção por R. conorii e as interacções hospedeiro - agente etiológico têm sido elucidados com base em modelos animais. Poucos estudos têm sido efectuados em doentes e nenhum estudo prévio tinha sido realizado no sentido de avaliar localmente (escara/pele) quais os mediadores ou outras moléculas envolvidas na resposta imunitária às rickettsioses. Foi avaliado o nível de expressão génica de RNA mensageiro (RNAm)de diferentes citoquinas em amostras de pele de doentes com FEN pela técnica de PCR em tempo real.Os resultados deste estudo mostraram que, quando comparado com o grupo controlo, os 23 doentes analisados apresentavam níveis estatisticamente significativos, mais elevados de expressão génica de interferão (IFN-γ, Tumor necrosis factor (TFN-α, interleucina 10 (IL-10, RANTES (regulated by activation, normal T-cell-expressed and secreted chemokine)e indolamina 2-3 desoxigenase (IDO),uma enzima envolvida no controlo e limitação do crescimento intracelular das rickettsias, através da degradação do triptofano. Seis dos 23 doentes apresentaram ainda niveis de expressão elevados de óxido nítrico indutível (iNOS)que actua como microbicida. Encontrou-se uma correlação positiva entre a expressão de RNAm de TNF-α, γ, iNOS e IDO e os casos menos graves de FEN sugerindo um tipo de resposta imunitária tipo Th1, i.e. com papel protector na resposta à infecção.Verificou-se também que os valores de expressão genética do RNAm de IL-10, estavam inversamente correlacionados com a expressão do RNAm de TNF-α e IFN-γ. Os casos menos graves de FEN parecem assim envolver um balanço entre a resposta pró-inflamatória e anti-inflamatória. Já os níveis de expressão génica do RNAm de IL-10 estavam inversamente correlacionados com a expressão RNAm de TNF-α e IFN-γ. Os casos menos graves de FEN parecem assim envolver um balanço entre uma resposta pró-inflamatória e anti-inflamatória. Já os níveis de expressão RNAm da quimoquina RANTES foram estatisticamente mais elevados em doentes graves.Nesta dissertação é ainda descrita uma nova rickettsiose presente em Portugal, causada pela bactéria R. sibirica mongolitimonae, que foi identificada laboratorialmente por isolamento do agente, e por detecção do DNA em biopsia de pele. A presença deste agente foi ainda corroborada pela detecção em paralelo do mesmo agente no ixodídeos como R. africae like e em pulgas como R. felis e R.typhi alertam para a possibilidade de existência de outras rickettsioses que possam estar diagnosticadas em Portugal. Abstract: Mediterranean spotted fever (MSF), a tick-borne disease caused by Rickettsia conorii, is widley distributed in the Old World, being endemic in the southern Europe, Africa, Middle East, India and Pakistan. In Portugal two strains cause disease: R.conorii Malish and R.conorii Israeli spotted fever.Rhipicephalus sanguineus, the brown dog tick, is considered the main vector and reservoir. MSF is characterized by seasonality, and most of cases are encountered in late spring and summer, peaking in July and August. However, CEVDI/INSA laboratory has observed that the incidence of MSF cases has changed during winter season.The increasing annual averages of air temperatures and warmer and drier winters might have influenced the dynamics of the life cycle and activity of R. sanguineus, and indirectley the number MSF cases during the so called MSF off-season.In the period of 1989-2005, the incidence rate of MSF was 8.4/105 inhabitants, one of the highest rates compared with other endemic countries. In the Portugal during the same period, the highest incidence rates were reported in the districts of Bragança, with 56.8/105 inhabitants, and Beja, with 47.4/105 inhabitants. Severe cases of MSF are reported in 6% of the patients, but it seems that this pattern of disease in Portugal has been changing.This factor became more evident in 1997, with a reported case fatality rate of 32% and 18% in patients with MSF admited at Beja and Garcia Orta Hospitals, respectively. Although it was found that diabetes mellitus and delay in therapy have been implicated as a risk factor for death, the hypothesis was considered, that the new ISF strain isolated from Portugueses patients in the same year (1997)causes different or atypical clinical conorii Malish strain. The local (skin biopsies) immune response to R. conorii infection was also evaluated.A prospective study was performed to characterized epidemiological, clinical, laboratory features and determined risk factors for a fatal outcome. One hundred forty patients (51% patients were infected with Rickettsia conorii Malish stain and 49% with Israeli spotted fever strain)with diagnosis documented with identification of the causative rickettsial strain were admitted to 13 Portugueses Hospitals during 1994-2006.Comparison of the clinical manifestations of MSF caused by Malish and ISF strains revealed tremendous overlap that would not permit clinical recognition of the strain envolved, but an eschar was observed in a significantly higher percentage of patients with Malish than ISF strain.A fatal outcome was significantly more likely for patients with ISF strain infection meaning that ISF strain was more virulent than Malish strain, and also alcoholism was a host risk factor for a fatal outcome.The pathophysiology of a fatal outcome involved significantly greater incidence of petechial rash, gastrointestinal symptoms, confusion/obtundation, dehydration, tachypnea, hepatomegaly, leukocytosis, coagulopathy, azotemia, hyperbilirubinemia, and elevated hepatic enzymes and creatine kinase. Multivariate analysis revealed that acute renal failure and hyperbilirubinemia were most strong associated with a fatal oucome of infections with both strains.The immune response to R. conorii infection determined with both strains. The immune response to R. conorii infection determined by the expression levels of inflammatory and immune mediators in skin biopsies collected from untreated patients with Mediterranean spotted fever reveal that intralesional expression of mRNA of TNF-α, IFN-γ, IL-10, RANTES, and indoleamine-2, 3-dioxygenase (IDO)an enzyme involved in limiting rickettsial growth by tryptophan degradation, were elevated in skin of MSF patients compared to controls. Six patients had elevated levels of inducible nitric oxide synthase (NOS2, a source microbicidal nitric oxide.Positive correlations among TNF-α, IFN-γ, NOS2,IDO and mild-to-moderate disease suggested that type 1 polarization plays a protective role. Significantly high levels of intralesional IL-10 were inversely correlated with IFN-γ and TNF-α. The chemokine RANTES was significantly higher in patients with several MSF. It seems that MSF patients with mild-to-moderate disease have a strong and balanced intralesional pro-inflammatory and anti-inflammatory response, while severe disease is associated with higher chemokine expression.Whether these findings are simply a correlate of mild and severe disease or contribute to anti-rickettsial immunity and pathogenesis remains to be determined.In this dissertation is also described a new rickettsiois present in Portugal caused by R.sibirica mongolitimonae strain, identified based on agent isolation and DNA detection by PCR technique in a skin biopsy.The presence of this agent corroborated by its detection also in Rhipicephalus pusillus tick. Also, pathogenic tick and flea-borne rickettsial agents such as R. africae strain detected in Rhipicephalus bursa tick, and R.felis and R.typhi detected in different fleas species raise the alert for the possible existence of other rickettsioses in Portugal that might be underdiagnosed.

Hepatic fascioliasis: case report and review

A well documented case of hepatic fascioliasis (HF), successfully treated with triclabendazole, is reported. Predominant clinical manifestations were fever, marked eosinophilia and abdominal pain. Triclabendazole was given as two single oral doses of 10 mg/kg each. Neither side effects nor clinical or parasitological relapses were seen after three months of follow up Based on this experience and few other similar reports in the literature, triclabendazole might be a valid therapeutical alternative in the treatment of human fascioliasis.

PREVALENCE OF HEPATITIS B AND HEPATITIS C MARKERS IN ALCOHOLICS WITH AND WITHOUT CLINICALLY EVIDENT HEPATIC CIRRHOSIS

We assessed the frequency of serological markers of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in 365 alcoholics by determining, by ELISA, the presence of HBsAg, anti-HBc, anti-HBs and anti-HCV. Fifty patients were cirrhotics and 315 had no evidence of hepatic cirrhosis; of the latter HBsAg was assessed in all, anti-HBc and anti-HBs in 130, and anti-HCV in 210. Among the alcoholics the frequencies of HBsAg (1.9%), anti-HBc (28.3%) and anti-HCV (3.8%) were higher (p<0.001) than among the controls (N=17,059), 0.4%, 4.0% and 0.4% respectively. The frequency of positive HBsAg was higher (p<0.001) in the cirrhotic patients (8.0%) than in alcoholics without cirrhosis (0.95%) and in controls (0.4%), and similar between the latter; of anti-HBc in alcoholics without cirrhosis (28.5%) was similar in cirrhotics patients (28.0%) and higher (p<0.001) than in the controls (4.0%); of anti-HBs in alcoholics without cirrhosis (20.8%) was similar to that of the cirrhotic patients (10.0%), and the anti-HCV was similar between alcoholics with (6.0%) and without cirrhosis (3.3%) and higher (p<0.001) than in controls (0.4%). We concluded that: a) alcoholics with or without cirrhosis have similar frequencies of infection with HBV and HCV between them, and higher than in nonalcoholics; b) alcoholics without cirrhosis had a frequency of HBV active infection (HBsAg+) which was similar to the controls, whereas among those who progressed to cirrhosis this frequency was significantly higher, what suggests that HBV may be implicated in the pathogenesis of cirrhosis in a few alcoholic individuals.

Projecto e concepção de um dispositivo experimental para medição e caracterização dos esforços aplicados no finca-pés de um caiaque de pista: Investigação, desenho e desenvolvimento

Após o enquadramento da canoagem, como modalidade Olímpica, verificou-se um aumento significativo de estudos e pesquisas acerca da biomecânica da modalidade, o que contribuiu para uma diminuição dos tempos na competição. Contudo poucos foram os que se focaram nas forças desenvolvidas e aplicadas ao caiaque através do finca-pés, criado assim oportunidade de desenvolvimento de dispositivos para a medição das mesmas. Assim, o objectivo primordial é desenvolver um sistema experimental capaz de quantificar as forças geradas em cada um dos lados do finca-pés (esquerdo e direito). Este, deverá não só ser passível de se utilizar em caiaque ergómetro como também num caiaque de pista, permitido avaliar as forças aplicadas durante o ciclo de pagaiada, tanto em compressão como em tracção. A sua concepção baseou-se num modelo de finca-pés já existente, tornando-o compatível com os caiaques de competição mais comercializados, e permitindo que no futuro se possa utilizar na água, bastando para isso apenas possuir um caiaque e embarcar o sistema de medição. Este sistema experimental foi testado em caiaque ergómetro por 7 (sete) sujeitos com níveis distintos: seis homens (um atleta olímpico medalhado e cinco de nível nacional) e uma mulher (de nível de selecção Portuguesa) que, entre outros, realizaram um plano definido por 60s a uma frequência de 75 pagaiadas por minuto, seguido de uma intensa mudança de ritmo e força (Sprint). Após análise dos dados obtidos em cada um dos diferentes sujeitos, conseguimos identificar algumas das suas características, tais como: esforço assimétrico dos membros inferiores; utilização de forma heterogénea da fita do finca-pés; diferença de forças máximas aplicadas entre atletas (Ex.: para um atleta olímpico as forças medidas (Min; Max): Pé Esquerdo (- 444; 1087) N e Pé Direito (- 476; 1068) N); etc. Os resultados não só são bastante promissores como também são motivantes e congruentes com estudos anteriores, nomeadamente Begon et al. 2008 e Sturm 2010 e 2012. Finalmente, consegue-se afirmar, com segurança, que foram alcançados os objectivos propostos com a concepção deste dispositivo de medição de forças. Este permite caracterizar os esforços desenvolvidos no finca-pés por cada membro inferior, com ou sem a fita de suporte, possibilitando aos treinadores e atletas uma visão, para muitos desconhecida, das forças transmitidas e das suas assimetrias. No final, este conhecimento permitirá aos atletas melhorar o seu desempenho desportivo bem como facilitar a gestão desportiva, com base nos principais princípios mecânicos inerentes ao movimento dos atletas desde desporto Olímpico.

Hepatic regeneration after partial hepatectomy in mice infected with Schistosoma mansoni, at the acute and chronic phases of the disease

Outbred male albino mice normal or infected with 30 cercariae of Schistosoma mansoni (LE strain) were submitted to 65% hepatectomy during the acute (70 days) and chronic phase (160 days) phases of the disease. A group of the infected animals was treated with 400 mg/kg of oxamniquine during the acute phase before hepatectomy. Non-infected, infected and treated but not hepatectomized animals were kept as controls. Hepatic regeneration was evaluated by incorporation of tritiated thymidine, intraperitoneally injected into non-hepatectomized and hepatectomized animals, 24 hours after surgery. The results showed that removal of 65% of the hepatic parenchyma, during the acute phase, led to a statistically significant increase of thymidine incorporation, when compared with the uninfected hepatectomized controls. This phenomenon was not observed at the chronic phase. Treatment with oxamniquine administered during the acute phase led to a decrease in thymidine incorporation rate 160 days after infection (90 days after treatment) and 24 hours after hepatectomy. The data suggest that infection with S. mansoni represents a considerable stimulus for the regenerative capacity of the liver during the acute, but not the chronic phase of disease.

Efeitos imediatos da técnica de mobilização com movimento aplicada na articulação tíbio-peroneal inferior na amplitude de dorsiflexão em indíviduos com história de entorse do tornozelo

RESUMO: A entorse do tornozelo é uma das lesões músculo-esqueléticas mais comuns. A limitação da amplitude de dorsiflexão tem sido demonstrada como uma das consequências desta lesão, bem como um dos factores contribuintes para a recorrência. Vários estudos têm demonstrado que o membro lesado de indivíduos com história de entorse, apresenta uma falha posicional anterior do peróneo. Um estudo realizado em cadáveres revelou que um deslizamento póstero-superior ao nível da articulação tibioperoneal inferior pode contribuir para aumentar a amplitude de dorsiflexão. Está descrita uma técnica de terapia manual que realiza o deslizamento póstero-superior do maléolo lateral associada ao movimento activo de flexão dorsal (MWM). No entanto, não existe, até à data, nenhum estudo que investigue a efectividade desta MWM em indivíduos com limitação da FD e história de entorse unilateral do tornozelo. Desenho de estudo: Ensaio clínico aleatorizado e controlado por placebo, duplamente cego. Objectivos: Avaliar os efeitos imediatos da MWM na articulação tibio-peroneal inferior na amplitude de flexão dorsal e no deslizamento posterior do astrágalo em indivíduos com história de entorse unilateral do tornozelo e limitação da flexão dorsal. O protocolo experimental foi aplicado uma única vez e os seus efeitos comparados com uma intervenção placebo. Metodologia: Uma amostra de 30 indivíduos com história de entorse unilateral e limitação da amplitude de flexão dorsal foi aleatoriamente distribuído por dois grupos: grupo MWM e grupo placebo. Foram avaliados o deslizamento posterior do astrágalo e a avaliação da amplitude de flexão dorsal em carga. As avaliações foram realizadas imediatamente antes e após a intervenção. Resultados: Não foram encontradas diferenças significativas entre os grupos na avaliação inicial (baseline). A realização da one-way ANCOVA revelou que, imediatamente após a intervenção, se verificou um aumento na amplitude de flexão dorsal no grupo MWM (aumento de 1.37 cm (DP, 0.97) significativamente superior ao grupo placebo (diminuição de 0.15cm (DP, 0.63) (P<.001). O deslizamento posterior do astrágalo aumentou 1.51º (DP, 1.77) no grupo MWM, no entanto este aumento não foi significativamente superior ao aumento de 0.76º (DP, 1.26) do grupo placebo (P=.113). Conclusão: Os resultados sugerem que a MWM na articulação tibioperoneal inferior produziram um efeito significativo na amplitude de flexão dorsal embora o mesmo não se tenha verificado no deslizamento posterior do astrágalo. Estes resultados fornecem evidência preliminar para a efectividade da MWM como intervenção em indivíduos com história de entorse unilateral e limitação da amplitude de flexão dorsal.---------------ABSTRACT:Background: Ankle sprains are one of the most common musculo-skeletal injuries. Impaired dorsiflexion range of motion has been shown to be one of the consequences of this injury, as well as one of the contributing factors to recurrence. Several studies have shown the presence of an anterior positional fault of the fibula in injuried ankles. A cadaveric study revealed that a posterosuperior glide of the distal tibiofibular may contribute to improve dorsiflexion. There is a manual therapy technique which provides a posterosuperior glide of the lateral malleolus combined with dorsiflexion active movement (MWM). However, there was no study, until now, that investigated the effectiveness of this MWM in individuals with impaired dorsiflexion and history of unilateral ankle sprain. Design: Double-blind randomized placebo controlled trial. Objectives: To determine the immediate effects of a distal tibiofibular MWM in ankle dorsiflexion and talar posterior glide in patients with history of unilateral ankle sprain and limitation of dorsiflexion. The treatment technique was used as a single treatment against a placebo group. Methods: A sample of 30 subjects with a history of unilateral ankle sprain and limitation of dorsiflexion were randomized into two groups: distal tibiofibular MWM or a placebo group. The outcome measures used in this study were the posterior talar glide and weight-bearing (WB) ankle dorsiflexion range of motion. The measures were taken before and immediately after the intervention. Results: No significant differences were found in baseline measures between groups. A one-way ANCOVA revealed that, immediately after the intervention, there was an improvement in ankle dorsiflexion in the MWM group (increase of 1.37 cm (SD, 0.97) significantly superior to the placebo group (decrease of 0.15cm (SD, 0.63) (P<.001). Posterior talar glide increased by 1.51º (SD, 1.77) for the MWM group, which was more than 0.76º (SD, 1.25) for the placebo intervention although there wasn’t a significant difference between groups (P=.113). Conclusion: This investigation’s findings suggest that an inferior tibio-fibular MWM produced a significant effect on WB dorsiflexion range of motion and posterior talar glide. These results provide preliminary evidence for the efficacy of mobilisations with movement in the management of individuals with history of unilateral ankle sprain and limitation of dorsiflexion.

Molecular aspects of hepatic carcinogenesis

Exogenous agents correlated with hepatocellular carcinoma (HCC) have been identified and well characterized. These agents, including the different viruses that cause chronic hepatitis and cirrhosis, can lead to regenerative nodules and dysplastic nodules/adenomatous hyperplasia. These conditions associated with several molecular alterations of hepatocyte ultimately culminate in hepatocellular carcinoma. Recently, there has been a great progress in the identification of somatic and germinative mutations that may be correlated with the development of HCC, justifying a review on the subject. Hence, the factors involved in the process of hepatic carcinogenesis, such as infection by the hepatitis B and C viruses, with a special focus in the molecular alterations described in recent years are discussed herein, pointing out areas potentially relevant for clinical development.

Numerical calculation of the left and right fractional derivatives

The calculation of fractional derivatives is an important topic in scientific research. While formal definitions are clear from the mathematical point of view, they pose limitations in applied sciences that have not been yet tackled. This paper addresses the problem of obtaining left and right side derivatives when adopting numerical approximations. The results reveal the relationship between the resulting distinct values for different fractional orders and types of signals.

Miosite Orbitária

Orbital myositis is a subgroup of the nonspecific inflammatory syndrome or orbital pseudotumor and is characterized by a primary inflammation of extraocular muscles. The authors describe a 70-year-old patient with acute proptosis, ocular pain and right ophthalmoplegia, whose orbital computed tomographic scan showed enlargement of the homolateral extraocular muscles. Clinical presentation and complementary tests were compatible with the diagnosis of orbital myositis however, because of the particular aspects, which included retinal central vein occlusion, optic nerve lesion, distension of the superior ophthalmic vein and the homolateral cavernous sinus, the differential diagnosis with cavernous sinus pathology and thyroid ophthalmopathy was considered. The importance of a rapid diagnosis and treatment is stressed.

Impacto da Estimulação Vagal na Indução e Interrupção de Fibrilhação Auricular no Modelo do Coração de Coelho in Vivo

INTRODUCTION: Vagal activity is thought to influence atrial electrophysiological properties and play a role in the initiation and maintenance of atrial fibrillation (AF). In this study, we assessed the effects of acute vagal stimulation (vagus_stim) on atrial conduction times, atrial and pulmonary vein (PV) refractoriness, and vulnerability to induction of AF in the rabbit heart with intact autonomic innervation. METHODS: An open-chest epicardial approach was performed in 11 rabbits (New Zealand; 3.9-5.0 kg), anesthetized and artificially ventilated after neuromuscular blockade. A 3-lead ECG was obtained. Atrial electrograms were recorded along the atria, from right to left (four monopolar electrodes), together with a circular electrode adapted for proximal left PV assessment. Acute vagus nerve stimulation was obtained with bipolar electrodes (20 Hz). Epicardial activation was recorded in sinus rhythm, and the conduction time from right (RA) to left atrium (LA), and from RA to PVs, was measured in basal conditions and during vagus_stim. The atrial effective refractory period (ERP) and dispersion of refractoriness (Disp_A) were analyzed. Vulnerability to AF induction was assessed at the right (RAA) and left (LAA) atrial appendages and the PVs. Atrial stimulation (50 Hz) was performed alone or combined with vagus_stim. Heart rate and blood pressure were monitored. RESULTS: In basal conditions, there was a significant delay in conduction from RA to PVs, not influenced by vagus_stim, and the PV ERPs were shorter than those measured in LA and LAA, but without significant differences compared to RA and RAA. During vagus_stim, conduction times between RA and LA increased from 16+8 ms to 27+6 ms (p < 0.05) and ERPs shortened significantly in RA, LAA and LA (p < 0.05), but not in RAA. There were no significant differences in Disp_A. AF induction was reproducible in 45% of cases at 50 Hz and in 100% at 50 Hz+vagus_stim (p < 0.05). The duration of inducible AF increased from 1.0 +/- 0.2 s to 12.0 +/- 4.5 s with 50 Hz+vagus_stim (p < 0.01). AF lasted >10 s in 45.4% of rabbits during vagus_stim, and ceased after vagus_stim in 4 out of these 5 cases. In 3 animals, PV tachycardia, with fibrillatory conduction, induced with 50 Hz PV pacing during vagus_stim. CONCLUSIONS: Vagus_stim reduces interatrial conduction velocity and significantly shortens atrial ERP, contributing to the induction and duration of AF episodes in the in vivo rabbit heart. This model may be useful for the assessment of autonomic influence on the pathophysiology of AF.

Aneurismas das Artérias Viscerais: Alternativa Terapêutica

The authors report two cases in which stent grafts were used to treat visceral artery aneurysms. Case number 1 was a 42-year old woman with a history of renal colic who was found to have a right renal artery aneurysm. Two 6-mm x 20-mm Wallgraft endoprosthesis (Boston Scientific, Watertown, Mass) were placed across the aneurysm neck. Case number 2 was a 72 year-old woman with a past medical history significant for hepatic angioma and hypothyroidism. She was found to have a superior mesenteric artery aneurysm that was treated with a 6-mm x 17-mm Jostent stent graft (Jomed, GmbH, Ra). In both cases the aneurysm was completely excluded and distal end-organ flow preserved. Stent graft placement is a safe and effective treatment for visceral artery aneurysms. If this approach proves durable and reproducible, it can become the method of choice for the management of visceral artery aneurysms in selected patients.