Marc Radermecker

Thiamine status in humans and content of phosphorylated thiamine derivatives in biopsies and cultured cells.

Background Thiamine (vitamin B1) is an essential molecule for all life forms because thiamine diphosphate (ThDP) is an indispensable cofactor for oxidative energy metabolism. The less abundant thiamine monophosphate (ThMP), thiamine triphosphate (ThTP) and adenosine thiamine triphosphate (AThTP), present in many organisms, may have still unidentified physiological functions. Diseases linked to thiamine deficiency (polyneuritis, Wernicke-Korsakoff syndrome) remain frequent among alcohol abusers and other risk populations. This is the first comprehensive study on the distribution of thiamine derivatives in human biopsies, body fluids and cell lines. Methodology and Principal Findings Thiamine derivatives were determined by HPLC. In human tissues, the total thiamine content is lower than in other animal species. ThDP is the major thiamine compound and tissue levels decrease at high age. In semen, ThDP content correlates with the concentration of spermatozoa but not with their motility. The proportion of ThTP is higher in humans than in rodents, probably because of a lower 25-kDa ThTPase activity. The expression and activity of this enzyme seems to correlate with the degree of cell differentiation. ThTP was present in nearly all brain and muscle samples and in ∼60% of other tissue samples, in particular fetal tissue and cultured cells. A low ([ThTP]+[ThMP])/([Thiamine]+[ThMP]) ratio was found in cardiovascular tissues of patients with cardiac insufficiency. AThTP was detected only sporadically in adult tissues but was found more consistently in fetal tissues and cell lines. Conclusions and Significance The high sensitivity of humans to thiamine deficiency is probably linked to low circulating thiamine concentrations and low ThDP tissue contents. ThTP levels are relatively high in many human tissues, as a result of low expression of the 25-kDa ThTPase. Another novel finding is the presence of ThTP and AThTP in poorly differentiated fast-growing cells, suggesting a hitherto unsuspected link between these compounds and cell division or differentiation.

Effect of celecoxib combined with thoracic epidural analgesia on pain after thoracotomy

BACKGROUND Thoracotomy results in severe postoperative pain potentially leading to chronic pain. We investigated the potential benefits of oral celecoxib on postoperative analgesia combined with thoracic epidural analgesia (TEA). METHODS Forty patients undergoing thoracotomy were included in this prospective, randomized, double-blind, placebo-controlled study. General anaesthesia was standardized. Patient-controlled epidural analgesia (T4-T5) was used during 48 h after surgery (ropivacaine 2 mg ml(-1) with sufentanil 0.5 microg ml(-1)). Patients were allocated to receive oral celecoxib or placebo from the evening before surgery until 48 h after operation. Postoperative pain scores, respiratory function, and morbidity were compared between the two groups. RESULTS Postoperative pain scores at rest (P=0.026) and during coughing (P=0.021) were lower and patient satisfaction was greater (P=0.0033) in the celecoxib group. Consumption of the local anaesthetic solution was comparable between groups. Postoperative restrictive pulmonary syndrome and morbidity were comparable between groups. CONCLUSIONS Celecoxib improves postoperative analgesia provided by TEA after thoracotomy.

Association of abdominal aortic aneurysm, horseshoe kidneys, and left-sided inferior vena cava: Report of two cases

Surgery for abdominal aortic aneurysm may be challenging when rare renal or venous anomalies are present. This article reports two similar cases of aortic abdominal aneurysm associated with horseshoe kidney and left-sided inferior vena cava treated with a transperitoneal approach. Preoperative knowledge of the anatomic situation enabled appropriate aneurysm repair. Operative strategy is discussed. This report describes an uncommon venous vascular malformation complex and stresses the importance of computed tomography imaging not only in assessing the characteristics of the aneurysmal disease but also in detecting variations in pertinent vascular or parenchymal anatomy.

Subacute Transcatheter CoreValve Thrombotic Obstruction

An 86-year-old man with severe symptomatic aortic stenosis (additive Euroscore 7) underwent a transcatheter aortic valve implantation with a CoreValve bioprosthesis (26 mm, CoreValve Revalving Technology, Medtronic, Inc., Minneapolis, MN). The patient was discharged on aspirin and clopidogrel and advised to stop the clopidogrel after 3 months. This first 6-month follow-up was uneventful. Repeated echocardiograms obtained during this period revealed a slight increase in mean transprosthetic aortic pressure gradient without significant concomitant aortic regurgitation. At the last visit, 1 year later, the patient became symptomatic (New York Heart Association class II–III). He had no fever. Between the 6th and 12th month of follow-up, there was a documented increase in transprosthetic aortic peak velocity (4.11 m/s) and mean gradient (41 mm Hg) and a significant reduction in aortic effective orifice area (0.69 cm2), which indicated severe prosthetic valve stenosis. To evaluate the shape of the CoreValve, both transesophageal echocardiogram and cardiac computed tomography were performed. Although computed tomography revealed no change in prosthesis position (when compared with pre–transcatheter aortic valve implantation computed tomography) and the absence of significant deformation of the stent by any calcifications (Figure 1A–1D), transesophageal echocardiogram evidenced thickened …

Pulmonary veno-occlusive disease in myeloproliferative disorder

The present study reports a case of biopsy-proven pulmonary veno-occlusive disease as a cause of severe pulmonary hypertension in a patient suffering from a chronic myeloproliferative disorder. The pulmonary disease evolved favourably under treatment with defibrotide, a pro-fibrinolytic medication used in hepatic veno-occlusive disease.

Cardiac paraganglioma: diagnostic work up and review of the literature.

Abstract Paraganglioma of the heart are potentially invasive, highly vascularized tumors for which complete resection may be curative. Derived from the cardiac wall in most instances, resectability can be assessed after integration of the data provided by MRI in T2 sequence, and coronarography. A fully documented case of a large cardiac pheochromocy-toma of the left atrium and AV groove is reported and the pertinent literature on the subject is here presented.

Cyclic Appearance of Left Ventricular Outflow Tract Dynamic Obstruction During Mechanical Ventilation: Evidence for a Preload Dependent Phenomenon

The cyclic appearance of dynamic left ventricular outflow tract obstruction during mechanical ventilation, according to the phasic changes in preload, is described in this article. Hemodialysis-induced fluid removal resulted in preload dependence as evidenced by the pulse pressure variation in a 56-year-old critically ill patient. The clinical picture was suggestive of myocardial failure. Transthoracic echocardiography disclosed dynamic left ventricular outflow tract obstruction associated with systolic anterior motion of the mitral valve. Progressive fluid restitution resulted in a parallel decrease in both the degree of dynamic obstruction and pulse pressure variation. During fluid loading, dynamic obstruction disappeared at first during the inspiratory phase of intermittent positive pressure ventilation corresponding to the phasic increase in left ventricular preload. Further fluid loading resulted in the disappearance of dynamic obstruction during both inspiratory and expiratory phase of intermittent positive pressure ventilation. This is the first reported case clearly relating left ventricular outflow tract dynamic obstruction to preload dependence during mechanical ventilation in a critically ill patient without predisposing anatomical factor.

Transapical beating-heart chordae implantation in mitral regurgitation: a new horizon for repairing mitral valve prolapse

Mitral regurgitation (MR) is increasingly prevalent in western countries despite reduced incidence of rheumatic disease (1,2). MR results from several heterogeneous conditions, including disorders of the valve leaflets, mitral annulus, chordae tendineae, papillary muscles and left ventricle (LV). MR causes are roughly classified as primary (i.e. organic/structural) or secondary (i.e. functional/non-structural) (3).

Management of Asymptomatic Severe Degenerative Mitral Regurgitation

ABSTRACT The decision for surgery in the management of asymptomatic severe degenerative mitral regurgitation (MR) is about doing the right thing at the right time and place. European and American guidelines have provided us with guidance on surgical indications, albeit with different levels of recommendations. However, the timing for surgery especially in asymptomatic patients not meeting Class I indications for intervention, i.e. no evidence of left ventricular dysfunction is still avidly debated. In this review, we will present the literature on the indications and timing of surgical intervention in asymptomatic severe MR, covering guidelines from both societies. We will also touch on the emerging role of other imaging techniques, biomarkers and exercise stress testing. Finally, we will present arguments for and against both management strategies, i.e. early surgery and watchful waiting. To summarize, the management of patients with asymptomatic severe degenerative MR should be a joint decision between all members of the Heart Team and tailored according to the availability of surgical expertise, patient’s surgical risk and patient’s wishes.

Surgical treatment of cardiovascular complications in patients with Marfan syndrome: a report of two cases and literature review.

Abstract Cardiovascular disease is the main cause of morbidity and mortality in patients with Marfan syndrome. The most life threatening complication is aortic root aneurysms leading to aortic dissection or rupture. It can be prevented by regular aortic follow-up and prophylactic aortic surgery. Modern aortic surgery has led to a substantial increase in the life expectancy of these patients. We report two cases of Marfan syndrome with cardiovascular complications. Their management is discussed according to the most recent literature.