[Evaluation with chest CT scan of CPAP as a treatment for tracheobronchomalacia in the frame of a Mounier-Kuhn syndrome]. / Évaluation par tomodensitométrie thoracique d'un traitement de la trachéobronchomalacie par pression positive continue dans le cadre d'un syndrome de Mounier­Kuhn.

INTRODUCTION: Tracheobronchomegaly disease is often associated with a tracheobronchomalacia which is responsible for recurrent lower respiratory tract infections. Currently there is no evidence to support any specific treatment for the condition. CASE REPORT: We report the case of a 79 years old patient presenting with tracheobronchomegaly in the context of Mounier-Kuhn syndrome complicated by a tracheobronchomalacia responsible for her symptomatology. The diagnosis of tracheobronchomalacia had been confirmed by high-resolution chest computed tomography (CT) with expiratory slices and virtual bronchoscopy. Treatment with continuous positive airway pressure (CPAP) was proposed, and we confirmed its efficacy using high-resolution chest CT, which showed a decrease in tracheobronchial collapse and a reduction in air trapping. CONCLUSIONS: Three-dimensional virtual bronchoscopy is an interesting tool and a noninvasive method to diagnose tracheobronchomegaly for patients who are at a high anesthetic risk. It is also possible to use it demonstrate the effect of CPAP in tracheobronchomalacia.

[Pre- and postoperative imaging of type B aortic dissection]. / Imagerie de la dissection aortique de type B : ce que veut savoir le chirurgien avant et après l'intervention.

Type B aortic dissections are serious diseases with a 60 to 80 % 5-year survival rate. Although typically managed with a medical treatment, surgery may be necessary in the acute/subacute or the chronic phase if significant complications are encountered. For these patients, CT angiography is the first-line imaging modality, used for indicating and preparing the surgical procedure as well as for follow-up. Physicians in charge of these patients should be familiar with the key reading points. Visceral malperfusion is the most common acute complication, while aneurysmal dilatation of the false lumen is the most common chronic complication, with surgical management generally indicated when the axial diameter of the aorta exceeds 55mm. Endovascular treatment tends to replace open surgery: it requires precise measurements and identification of the entry tear (contribution of 4D-MRA).

Human thymus medullary epithelial cells promote regulatory T-cell generation by stimulating interleukin-2 production via ICOS ligand.

Natural thymic T regulatory (tTreg) cells maintain tolerance to self-antigen. These cells are generated in the thymus, but how this generation occurs is still controversial. Furthermore, the contribution of thymus epithelial cells to this process is still unclear, especially in humans. Using an exceptional panel of human thymic samples, we demonstrated that medullary thymus epithelial cells (mTECs) promote the generation of tTreg cells and favor their function. These effects were mediated through soluble factors and were mTEC specific since other cell types had no such effect. By evaluating the effects of mTECs on the absolute number of Treg cells and their state of proliferation or cell death, we conclude that mTECs promote the proliferation of newly generated CD25+ cells from CD4+CD25- cells and protect Treg cells from cell death. This observation implicates Bcl-2 and mitochondrial membrane potential changes, indicating that the intrinsic cell death pathway is involved in Treg protection by mTECs. Interestingly, when the mTECs were cultured directly with purified Treg cells, they were able to promote their phenotype but not their expansion, suggesting that CD4+CD25- cells have a role in the expansion process. To explore the mechanisms involved, several neutralizing antibodies were tested. The effects of mTECs on Treg cells were essentially due to interleukin (IL)-2 overproduction by thymus CD4+ T cells. We then searched for a soluble factor produced by mTECs able to increase IL-2 production by CD4+ cells and could identify the inducible T-cell costimulator ligand (ICOSL). Our data strongly suggest a « ménage à trois ¼: mTEC cells (via ICOSL) induce overproduction of IL-2 by CD25- T cells leading to the expansion of tTreg cells. Altogether, these results demonstrate for the first time a role of mTECs in promoting Treg cell expansion in the human thymus and implicate IL-2 and ICOSL in this process.

Acute and chronic thoracic aortic disease: surgical considerations.

Acute thoracic aortic aneurysm is one of the most life-threatening vascular disorders recognized to date. The majority of these aortic ruptures rapidly end in mortality, with 50% of patients suffering death before reaching the hospital. Thus, acute management through surgical intervention is often indicated, especially in cases of ascending aortic rupture. Physical examination is critical in making the diagnosis, as clinical signs and symptoms often vary depending on the location of the dissection. Clinicians should have a low threshold for including thoracic aortic dissection in their differential diagnosis, especially when a patient presents with acute onset chest or back pain. In this report, we discuss the different categories of aortic dissections and the current treatment modalities for each. These include endovascular aortic repair, which has become a viable treatment modality in certain cases of type B dissection. Offering a less invasive approach, the technique known as thoracic endovascular repair currently affords a treatment option to a patient population who would have otherwise been deemed non-surgical candidates. Hybrid thoracic endovascular aortic repair has also become a pertinent surgical technique, and successful outcomes have been demonstrated when it is employed to repair ascending aortic aneurysms. We also describe our Acute Aortic Treatment Center, a rapid multicentric triage system for the management of acute aortic pathologies, which has resulted in significant improvements in patient outcomes.

Computational study of haemodynamic effects of entry- and exit-tear coverage in a DeBakey type III aortic dissection: technical report.

OBJECTIVES: Outcome prediction in DeBakey Type III aortic dissections (ADs) remains challenging. Large variations in AD morphology, physiology and treatment exist. Here, we investigate if computational fluid dynamics (CFD) can provide an initial understanding of pressure changes in an AD computational model when covering entry and exit tears and removing the intra-arterial septum (IS). DESIGN: A computational mesh was constructed from magnetic resonance images from one patient (one entrance and one exit tear) and CFD simulations performed (scenario #1). Additional meshes were derived by virtually (1) covering the exit tear (false lumen (FL) thrombus progression) (scenario #2), (2) covering the entrance tear (thoracic endovascular treatment, TEVAR) (scenario #3) and (3) completely removing the IS (fenestration) (scenario #4). Changes in flow patterns and pressures were quantified relative to the initial mesh. RESULTS: Systolic pressures increased for #2 (300 Pa increase) with largest inter-luminal differences distally (2500 Pa). In #3, false lumen pressure decreased essentially to zero. In #4, systolic pressure in combined lumen reduced from 2400 to 800 Pa. CONCLUSIONS: CFD results from computational models of a DeBakey type III AD representing separate coverage of entrance and exit tears correlated with clinical experience. The reported results present a preliminary look at a complex clinical problem.

Partial recovery of delayed graft function due to cholesterol emboli after renal transplantation.

A 65-year-old man who received a deceased renal allograft in September 2001. The donor of the allograft was a 54-year-old hypertensive man who expired from intracerebral hemorrhage. Atheroma with hard plaques was present in both renal arteries and aortic patches. After vascular anastomosis and clamp release, the allograft recoloration was inadequate, and the patient remained anuric. Computerized tomography scan demonstrated disseminated infarction areas, suggesting cholesterol emboli, which was confirmed later by a graft biopsy. As approximately 50% of the renal parenchyma was perfused, graft nephrectomy was not indicated and dialysis was restarted. Diuresis was over 3000 ml/day and serum creatinine decreased and stabilized at 360 micromol/L by the 32nd postoperative day. The allograft supported the patient for only two years, and he eventually was successfully retransplanted in June 2003. We believe that delayed graft function due to cholesterol emboli disease may be reversible if areas of infarction are not too large.

Expression of pemphigus-autoantigen desmoglein 1 in human thymus.

Desmoglein (Dsg) 1 is a transmembrane glycoprotein of the desmosome allowing cell-cell adhesion between keratinocytes, whose expression is restricted to stratified squamous epithelia-like epidermis. Dsg1 is the target autoantigen of pathogenic autoantibodies produced by pemphigus foliaceus and 50% of pemphigus vulgaris patients in a Dsg1-specific T-cell-dependent pathway. Herewith, we show that mRNA of the DSG1 gene is present in normal human thymus and show by quantitative real-time polymerase chain reaction analysis that the expression of DSG1 transcript increases with age. Although immunoblot analysis on human thymus extracts using different anti-Dsg1 antibodies did not allow to detect the protein, we show by double-immunofluorescence assay that Dsg1 is expressed at protein level by CD19+ CD63+ cells located in the medulla. These data provide another illustration of the thymic expression of a tissue-specific autoantigen involved in an organ-specific autoimmune disease, which may participate in the tolerance acquisition and/or regulation of Dsg1-specific T cells.

[An analytical classification of fractures of the distal radius: The "M.E.U." classification]. / Classification analytique des fractures de l'extrémité distale du radius : la classification << M.E.U. >>

INTRODUCTION: Fractures of the distal radius are often complex injuries involving to a varying degree the radial metaphysis (M), radial epiphysis (E) and distal ulna (U). The association of these three parameters varies in a given injury and each fracture is a specific lesion which often defies inclusion in a well-defined group. An analytical classification is proposed. MATERIALS AND METHODS: The classification system analysed the three components of the fracture, assigning to each an index of gravity increasing from 0 to 4 and taking into account the main prognostic factor. Interobserver and intraobserver evaluation was carried out. The system was a posteriori applied to a prospective series of 166 distal radius fractures. RESULTS: Mean interobserver reliability was 0.78 and mean intraobserver reproducibility 0.81. M and E were closely correlated with treatment, M with algodystrophy, E with pain and U with mobility and patient satisfaction at one year. CONCLUSIONS: Inter- and intraobserver reproducibilities were good and the results validated our gravity indexes. This classification, describing all possible combinations of the three components of the fracture, is useful for both prognosis and treatment.

[Sequential protocols with thymoglobuline and delayed introduction of calcineurin: effects on renal function in renal transplant recipients with non immunological risk and low risk of delayed graft function]. / Protocoles séquentiels avec induction par thymoglobulines et introduction retardée des inhibiteurs de la calcineurine: effets sur la fonction du greffon chez le transplanté rénal sans facteur de risque.

Induction therapy with thymoglobuline significantly decreases the risk of acute rejection, particularly in high immunological risk patients, in combined transplantations and in pediatric renal transplantation. After the introduction of cyclosporin in the 1980's and the recognition of its potential nephrotoxicity, induction therapy with delayed introduction of cyclosporin (sequential protocols) have became very popular in many transplant centers and are now used even in low-immunological risk patients. The aim of the present study was to assess the recovery of renal function in low-immunological risk patients receiving a sequential protocol versus those receiving a calcineurin inhibitor at day 1. Among patients receiving their first transplant in our center between January 1999 and June 2000, we selected 72 recipients with no immunological risk and no risk of delayed graft function (DGF). 35 patients (group I) have received a sequential protocol whereas 37 patients (group II) have received a calcineurin inhibitor (Neoral or prograf) at day 1. We analysed creatinine reduction ratio, 24-hour creatinine excretion on post-transplant day 2, and serum creatinine and creatinine clearance at day 15, 30, 45, 60 and 90 post-transplant. There was no difference between groups concerning demographic, immunological or surgical parameters. The percentage of patients with immediate graft function was similar between the two groups (10 versus 9). The number of patients requiring dialysis in the first post-transplant week was also similar (8/35 versus 6/37). The day serum creatinine reached 200 micromol/l was 15 +/- 11 versus 14 +/- 12 in groups I and II respectively. Serum creatinine and creatinine clearance were similar at all time intervals. CMV disease was significantly higher in the group 1 (42% versus 18.5%; p < 0.005). Our data suggest that in patients with low immunological risk and low-risk of DGF, introduction of calcineurin inhibitors as early as the post-transplant day 1 is not deleterious for renal function recovery. These data should be confirmed by a prospective randomised trial.

[Nocardiosis--is it frequently observed after the introduction of new immunosuppressive agents in renal transplantation?]. / La nocardiose est-elle plus fréquemment observée depuis l'introduction des nouveaux immunosuppresseurs en transplantation rénale?

In our series of 1374 renal transplantations performed between February 1970 and December 2002, we observed 6 cases of infection due to Nocardia asteroides. There were 4 males and 2 females, aged 49.8 +/- 12 years (29 to 63 years). One patient received his first transplantation and the 5 others retransplants. Three patients had PRA > 80%, one 28% and one 40%. One patient was diabetic and two had HCV infection. Two of 6 patients experienced acute rejection episodes. Nocardiosis localisation was pulmonary in 5 cases, cerebral in two and mediastinal in one. All patients recovered after reduction of immunosuppression and appropriate antibiotherapy with trimethoprim-sulfamethoxasole (TMP-SMX). When we analyzed the role of immunosuppression, we observed that only two cases were observed in the 933 recipients transplanted between 1985 and 2002 and receiving cyclosporin, contrasting with 4 cases among 174 recipients transplanted between 1996 and 2002 and receiving tacrolimus. Our data suggest that high immunologic risk patients, heavy immunosuppression, and perhaps tacrolimus-based immunosuppression are risk factors of nocardial infection. Early diagnosis of this severe infection, reduction of immunosuppression and appropriate therapy with TMP-SMX resulted in complete recovery in all our patients.

[Thyreotoxic periodic paralysis. A cause of pseudo-paralysing hypokalemia that should not be ignored in Caucasians]. / Paralysie périodique thyréotoxique. Une cause d'hypokaliémie pseudoparalysante à ne pas méconnaître chez le Caucasien.

INTRODUCTION: Despite its rare occurrence in Caucasians, thyreotoxic periodic paralysis should be evoked in young male Caucasians presenting with episodes of pseudo-paralytic hypokalemia. OBSERVATION: A 37 year-old Caucasian was admitted in intensive care for an acute episode of hypotonic tetraplegia and hypokalemia during which laboratory tests revealed hyperthyroidism due to Basedow's disease. The clinical course was rapidly favourable after a small dose of intravenous potassium. Antithyroid treatment avoided any new occurrence of similar episodes. DISCUSSION: In Caucasians, sporadic acute paralysis with hypokalemia requires testing for hyperthyroidism. Though it is well know that hypokalemia results from potassium intracellular shift, the underlying mechanism remains poorly elucidated. Treatment includes potassium administration with caution and/or beta blockers but the specific treatment is that of hyperthyroidism.

Real-time spatial compound imaging improves reproducibility in the evaluation of atherosclerotic carotid plaques.

Compound imaging has the ability of reducing speckle and clutter artifacts demonstrated in in vitro studies compared to conventional, single-angle imaging. We investigated intra- and interobserver agreement of 38 outlines of carotid artery plaque images acquired by these techniques, by measuring the overlapping area after repeated outlines. In general, both techniques showed good agreement. When considering the images with poorest overlap, compound imaging had a significant advantage over conventional imaging regarding both intra- and interobserver agreement. The interobserver variation for the overlapping area after two outlines was 20% for conventional technique and 10% for compound. The interobserver variation of the gray scale median value (GSM) for conventional technique ranged from -32 to +20 and from -6 to +6 for compound. Likewise, the coefficient of repeatability for the GSM value was 13 for conventional imaging and three for compound imaging, and interobserver variation for the GSM value for the overlapping area was 34% and 9% for conventional and compound technique. In conclusion, compound imaging improves intra- and interobserver agreement and reduces interobserver variation in the GSM value in a clinical setting.

Angioplasty for the treatment of buttock claudication caused by internal iliac artery stenoses.

A case of buttock claudication due to isolated internal iliac artery stenoses is presented. Although ankle systolic pressure at rest was within normal limits and distal pulses were palpable, an angiogram demonstrated severe stenoses. A computed tomography scan showed no spinal stenosis. The patient was successfully treated with angioplasty. This diagnosis may be elusive if ankle pressure or distal pulses are normal, thereby directing the clinician's suspicion away from vascular pathology.

The lack of cardiovascular risk factor management in patients with critical limb ischaemia.

AIM: to define the level of management of cardiovascular risk factors in patients treated for critical limb ischaemia in a vascular surgical setting. MATERIALS AND METHODS: retrospective review of all (n =147) patients operated on for critical lower extremity ischaemia in 1998. We included pre- and postoperative cardiac events. RESULTS: only eight (5%) (95% CI; 2-9) were on lipid lowering treatment and 58 (39%) (95% CI; 31-47) using acetylsalicylic acid. CONCLUSIONS: only a minority of patients operated on for CLI were receiving adequate cardiovascular risk factor modification.

[Lipid lowering treatment of patients with atherosclerotic disease of the lower extremities]. / Lipidsaenkende behandling af patienter med aterosklerotisk sygdom i underekstremiteterne.

Patients with critical peripheral ischaemia have a significant mortality rate of up to 50% within 4-5 years of surgical vascular reconstruction. This poor survival rate is due to concomitant coronary and cerebrovascular atherosclerotic disease. Large randomised trials have shown that dyslipidaemia is easily modifiable in patients both with and without established coronary artery disease, with significant reductions in cardiovascular morbidity and mortality. Although none of these trials directly measured peripheral vascular status, there is every indication that conclusions submitted for patients with ischaemic heart disease can be translated to patients with peripheral arterial disease (PAD). The object of this review was therefore to divulge the current evidence available, which supports active treatment of dyslipidaemia in patients with PAD.

Intraluminal calcification of the abdominal aorta.

A patient who had no evidence of atherosclerotic disease and had never been hypertensive, presented with symptoms usually associated with gallstone disease. A large intraluminal calcification in the juxtarenal aorta was found to be the probable cause of these symptoms. The aorta was otherwise free of atherosclerotic changes. Although it could not be identified with certainty, this calcification could have developed secondary to a single ulcerated atheroma.

Intracarpal ligamentous lesions associated with fractures of the distal radius: outcome at one year. A prospective study of 95 cases.

Intracarpal ligamentous lesions associated with fractures of the distal radius (FDR) are frequent. The prevalence of these lesions has been assessed either by arthrography or by arthroscopy, but their outcome remains unknown. We carried out a radiographic study to assess the incidence of intracarpal ligamentous lesions with scapholunate (SL) and/or lunotriquetral (LT) dissociation and their outcome at one year. These lesions were termed "dissociative ligamentous lesions" (DLL). This prospective series consisted of 102 consecutive FDR's. The initial x-rays, immediate postoperative x-rays and x-rays at 1 year were studied. We studied the relationships of the bones of the first carpal row, abnormal joint space widening, Gilula's lines and the values of the intracarpal angles. The evolution of the carpal height ratio between day 0 and one year was studied. Complete xrays were available for 95 patients. There were 9 epiphyseal, 45 metaphyseal and 41 mixed fractures. DLL's were diagnosed in the early stages in 40 patients. There were 29 isolated SL lesions, 2 isolated LT lesions and 9 cases of associated SL and LT lesions. At 1 year, the diagnosis was confirmed in all these cases but a further case of SL dissociation was diagnosed. At 1 year, 61% of DLL's showed significant loss of carpal height and were considered as progressive. There was an association between the type of fracture and the presence or absence of DLL (p = 0.02). This study, based on radiographic analysis alone, showed 43% DLL's. The majority could be identified immediately. These findings are similar to those in recent arthrographic or arthroscopic studies, but the interest of plain radiographic study is to diagnose only those lesions having a definite effect on the carpus ("static instability"). At 1 year, 61% of lesions diagnosed have significantly affected carpal height.

Effects of adrenal steroid hormones on mitochondrial maturation during the late fetal period.

In the present work, we described the perinatal changes in mitochondrial maturation that contribute to metabolic development in the rat kidney. We focused on cytochrome-c oxidase activity and gene expression from the last three days of gestation to one day after birth. The role of adrenal steroids in the development of cytochrome-c oxidase expression and of mitochondrial DNA content was also investigated by studying the effects of fetal adrenalectomy. During the perinatal period, the developmental pattern of the cytochrome-c oxidase enzymatic complex exhibited parallel increases in transcript levels, protein content and enzyme activity, suggesting a transcriptional regulation of this enzyme. Adrenalectomy led to a decrease in fetal kidney cytochrome-c oxidase messengers and mtDNA content while administration of dexamethasone restored normal levels. In contrast, mtDNA content was unchanged in liver and heart after adrenalectomy whereas levels of cytochrome-c oxidase transcripts were controlled by adrenal steroids in liver but not in heart. These results indicate that adrenal steroid hormones contribute to the regulation of perinatal maturation of mitochondria in rat kidney and that these hormones are involved in the fetal mitochondrial biogenesis in a tissue-specific manner.

Effect of hyperglycemia on the polyol pathway in rat kidney during the perinatal period.

The activity of the polyol pathway was studied in developing rat kidney. For this purpose, sorbitol content, aldose-reductase activity and sorbitol-dehydrogenase activity were determined in papilla from fetuses and 24-h-old neonates. After birth, no significant difference was observed in sorbitol content, whereas sorbitol-dehydrogenase activity decreased and aldose-reductase activity doubled. Changes in aldose-reductase activity were due to an increased number of enzymatic sites but not with a change in affinity. Low levels of sorbitol were found in fetal and neonatal medulla together with low levels of urine osmolarity. In neonates, sorbitol contents were tenfold lower than in the adult, probably as a result of a lower affinity and a lower number of enzymatic aldose-reductase sites. Attempts to increase the activity of polyol pathway in fetal kidney were made by means of hyperglycemic animals; this approach resulted in an increase of aldose-reductase activity without any change in sorbitol content. Our results indicate that, in fetal and neonatal kidneys, aldose-reductase activity is probably not the limiting factor for sorbitol synthesis; another parameter, such as the availability of NADPH, might explain the low efficiency of the polyol pathway during the perinatal period.