Expression of factors involved in dental pulp physiopathological processes by nemotic human pulpal fibroblasts.

AIM: To investigate in human dental pulp fibroblasts (HDPF) the expression of factors involved in dental pulp physiopathological processes and in an experimental model of cell activation called nemosis, and to compare the behaviour of pulp cell activation with sound lung fibroblast MRC5, employed as a reference model for nemosis. METHODOLOGY: Nemotic response was induced in three-dimensional cultures of HDPF and lung fibroblasts. The expressions of molecules involved in physiological (alkaline phosphatase, type I collagen) and in inflammatory processes (IL-6, CXCL8, CCL20, COX-2) were studied using real-time PCR. Concentrations of IL-6 and CXCL8 were analysed during 4 days with ELISA. Nonparametric tests were used to determine statistical differences between groups. RESULTS: A significant decrease (P < 0.001) in type I collagen and alkaline phosphatase was observed in MRC5 and HDPF nemotic responses. Although the amounts of mRNA differed between these cell types, there was an increase in CCL20, CXCL8 and COX-2 expression (P < 0.001). Unlike HDPF, MRC5 spheroids displayed significant amounts of IL-6 concentrations and mRNA expression. Notably, increased concentrations of CXCL8 were recorded in all three-dimensional cultures compared with monolayers as a function of time (P < 0.05). CONCLUSION: Although the nemotic responses observed were not identical in the pulpal and lung fibroblasts, similarities occurred in the expression of chemokines and cyclooxygenase-2. Nemotic reactions and inflammatory processes in pulp diseases share similarities in terms of the expression of factors. Thus, this in vitro model could constitute a powerful tool to study intercellular relations within the dental pulp and to develop new local treatments to counteract the inflammatory reaction that occurs during pulpitis.

Characterization of a programmed necrosis process in 3-dimensional cultures of dental pulp fibroblasts.

AIM: To analyse and compare the expression of necrosis markers in human lung and dental pulp fibroblasts and to determine whether this process differs by the type of mesenchymal cell. METHODS: Human dental pulp fibroblasts were obtained from unerupted third molars. Sound lung and pulpal fibroblasts were cultured in vitro as spheroids to determine the expression of the necrosis hallmark cyclooxygenase-2 (COX-2) mRNA using RT-PCR and the concentrations of vascular endothelial growth factor (VEGF) and hepatocyte growth factor/scatter factor (HGF/SF) proteins using an ELISA test. Cell viability within spheroids was also compared with spheroid diameters over time. RESULTS: Increased expression of COX-2 and VEGF was found in all spheroids compared with corresponding monolayers. Although HGF/SF was highly expressed in MRC5 cells, dental pulp fibroblasts aggregates maintained only a basal level compared with monolayer cultures. Further, the observed progressive loss of viable cells explained the decreased diameters of spheroids over time. The results demonstrate that necrosis occurs in sound lung and pulpal fibroblasts. This cell death also displays differences between these two different cell types, as they do not produce the same growth factors quantity release. CONCLUSIONS: The necrosis process occurred in human dental pulp fibroblasts and is different between the two cell types studied. This in vitro experimental necrosis model could become an interesting inflammatory tool. More investigations are needed to compare necrosis process in dental pulp fibroblast and inflammation during pulpitis.

[The heart surgery department]. / Le Service de Chirurgie Cardiaque.

The initial development of cardiac surgery at Erasme Hospital was closely related to the achievements in thoracic organ transplantation, with numerous synergies between other clinical and research units of the Faculty of Medicine. New advances in biology and biotechnology have met the challenges of modern cardiology, in the fields of advanced heart failure, refractory angina, rhythm disturbances or minimally invasive surgery. Fundamental aspects of clinical practice have been the subject of laboratory investigations, resulting in fruitful interactions and promising scientific outlooks.

Conversion from ministernotomy to full sternotomy in aortic valve replacement.

Conversion (C) from ministernotomy (M.S.) to full sternotomy was necessary in 5% of the cases in a series of 100 patients consecutively operated for Aortic Valve Replacement (A.V.R.) Analysis of the demographics and surgical techniques indicate older age, aortic fragility, diffuse coronary disease, chronic renal failure and left vent insertion as contributing factors. Despite increased operative blood losses, extra-corporeal circulation (E.C.C.) times, intensive care unit (I.C.U.) stay and hospital stay, no mortality was observed in the conversion group, as compared to 4.2% mortality in the total ministernotomy (MS) population. Preoperative patients selection, avoidance of technical pitfalls, and knowledge of alternative surgical measures are suggested to further decrease the incidence of conversions.

[Minimally invasive valvular surgery]. / Chirurgie valvulaire moins invasive.

Surgery for cardiac valvular pathology is one of the great success of the 20th century. Until recently the surgical techniques were centered on median sternotomy and cardiopulmonary bypass with aortic and atrial cannulation. The changes in cardiac surgical technique for minimally invasive valve surgery include: a different and smaller incision to minimize trauma to the body, a new technique of connecting the patient to the cardiopulmonary bypass, a different technique for myocardial perfusion and aortic occlusion.

Left ventricular outflow tract obstruction after mitral valve replacement.

We describe a patient with left ventricular outflow tract obstruction after mitral valve replacement preserving the anterior subvalvular apparatus. Postoperative transesophageal echocardiography demonstrated systolic narrowing of the left ventricular outflow tract by a bulging septum and systolic anterior motion of the preserved anterior mitral leaflet. Septal myectomy and transaortic mitral apparatus resection enabled us to relieve the left ventricular outflow tract obstruction. This suggests that septal hypertrophy might be a relative contraindication to the preservation of the anterior mitral subvalvular apparatus in mitral replacement.

Results of mitral valve reconstruction. Experience of Hôpital Erasme, ULB, Brussels.

BACKGROUND: Reconstructive surgery of the mitral valve has been an alternative to mitral valve replacement in patients with mitral regurgitation. In order to evaluate the early results of mitral valve reconstruction, 38 consecutive cases were analyzed. METHODS: Between January 1985 and May 1993, 38 patients with mitral valve incompetence were treated with a system of reconstructive techniques. Nineteen (52%) of the patients were in NYHA functional class II and seventeen (45%) in class III or IV preoperatively. The cause of the mitral disease was degenerative in 25 (66%), rheumatic in 6 (15%) and ischaemic in 5 (13%) patients. Isolated mitral valve repair was performed in 25 patients (66%); the remainder underwent associated procedures that included a myocardial revascularization in 9 patients (23.6%). Thirty-eight patients (100%) underwent a ring annuloplasty. Resection of the posterior leaflet was performed in 24 patients (63%). RESULTS: There was one operative death (2.6%) and two late deaths (5.3%). Postoperatively, four patients sustained embolic events (incidence 10.5%). Six patients (15.8%) were precociously reoperated within the following month; two patients required valve replacement, one had mediastinitis and three other ones needed a pericardial drainage. Patients routinely received acenocoumarol anticoagulation for two months. Mean follow-up was 33 months (range 6 to 104) and one patient was lost to follow-up. Two years actuarial survival was 91.4%. There were no thromboembolic complications in the follow-up period. No patient was reoperated for valvular insufficiency beyond this time limit. One patient had late endocarditis and has been reoperated for mitral replacement (2.6%). After surgery, 34 survivors (89.5%) were in the NYHA functional class I or II. CONCLUSIONS: These results demonstrate that mitral valvuloplasty is associated with lower operative mortality rates. Preservation of the mitral valve mechanism raised the performance of the left ventricle after reconstructive surgery. The incidence of reoperation and thromboembolism was low.

Relation between oxygen consumption and oxygen delivery in patients after cardiac surgery.

The relative contributions of oxygen delivery (DO2) and oxygen extraction (O2ER) to the increase in cellular oxygen uptake (VO2) after cardiopulmonary bypass were studied prospectively in 36 patients after coronary artery bypass grafting (n = 18), valve replacement (n = 17), and removal of a left atrial tumor (n = 1). VO2 was calculated from the Fick equation and DO2 from thermodilution cardiac output and arterial oxygen content. During the first 24 h after cardiac surgery, there was a strong relation between VO2 and DO2 (VO2 = 28 + 0.27 x DO2, r = 0.79, P < 0.0001) but not between VO2 and oxygen extraction. Mixed venous oxygen saturation (SVO2) was usually reduced when cardiac index was below 2.0 L.min-1.m-2. Patients with a prolonged intensive care unit course (> 24 h) had lower cardiac index and lower SVO2 than the other patients. Therefore, the progressive increase in VO2 after cardiac surgery is accomplished primarily by an increase in cardiac output and DO2. It is usually when cardiac function is compromised that O2ER increases and SVO2 decreases.

Acute myocardial infarction immediately after heart transplantation.

Myocardial infarction is one of the rarer events causing acute graft failure during the postoperative period after transplantation and is usually caused by preexisting coronary artery disease of the donor heart. We discuss the case of a 56-year-old man in whom cardiogenic shock developed after heart transplantation, which was refractory to all medical treatment. He was put on emergency code and underwent retransplantation 30 hours later. Pathologic examination of the explanted donor heart showed massive recent inferior and posterior wall infarction, with normal coronary arteries; the right coronary artery was dominant and completely occluded by an embolus of fatty material surrounded by fibrin, which we suggest could have originated from the suture line of the left atrium.

Hemodynamic evaluation of bisoprolol after coronary artery surgery in patients with altered left ventricular function.

Bisoprolol is a new cardioselective beta1 adrenergic blocking agent without intrinsic sympathomimetic activity but with minimal effects on myocardial contractility. Bisoprolol was compared to propranolol in 24 patients after cardiac surgery for coronary artery bypass graft (CABG). Each patient had been treated preoperatively with beta-blocking agents and had a cineangiographic left ventricular ejection fraction between 35% and 55%. Patients were randomized to receive orally either 10 mg of propranolol three times a day or 5 mg of bisoprolol once a day. Both drugs resulted in a significant and similar decrease in heart rate. This was associated with significant decreases in cardiac index, stroke index, and thermodilution right ventricular ejection fraction 6 hours after administration of propranolol, but not after bisoprolol. Systolic function measured by Doppler techniques significantly increased in the 10 postoperative days in patients under bisoprolol but not significantly after propranolol. Each drug was well tolerated during the 10 postoperative days, and the recovery was uneventful in each patient. These results indicate that in patients with altered systolic function after CABG, bisoprolol is susceptible to reduce heart rate with less cardiovascular alteration than propranolol.

Echocardiographic signs of cardiac rejection during the first week after cardiac transplantation.

The early recognition of acute rejection after heart transplantation remains an important clinical problem. In this study we explored the value of echo-Doppler techniques to identify the rejection during the first week after cardiac transplantation. The study included 22 patients with an average age of 48 +/- 9 years. Ultrasonic measurements were obtained by 2-dimensional 84 degrees phased array sector scanner with pulsed Doppler incorporated. The stroke index (SI), the peak outflow blood velocity pulsed (POBVP), the peak outflow blood acceleration pulsed (POBAP), the peak flow velocity in early diastole (PFVE), the peak flow velocity during atrial systole (PFVA), the PFVA/PFVE ratio, the mitral valve pressure half-time (PHT) and the fractional shortening (FS) were calculated. On the seventh day after transplantation, a percutaneous right ventricular endomyocardial biopsy was systematically performed. For the entire group, the SI, PHT and the FS relation were not significantly influenced during the week of evaluation. The POBVP and the POBAP transiently decreased but returned to baseline on the seventh day. An increment in the PFVA/PFVE ratio was observed in 4 patients, and acute allograft rejection was documented in 3 of them. On day 7 after transplantation, PFVA and PFVA/PFVE were significantly higher in patients with rejection. No patient with normal PFVA/PFVE ratio had allograft rejection. No patient with rejection showed signs of altered systolic function as measured by SI, POBVP, POBAP and FS. These data therefore indicate that the assessment of the diastolic function using Doppler techniques (PFVA/PFVE) can be helpful to detect signs of acute allograft rejection occurring early after heart transplant.

The role of colour as a monocular depth cue.

Does colour information play a role in the perception of depth? Its input to stereopsis is weak, and it has been suggested that depth from monocular cues, such as texture gradients, is also abolished at isoluminance (colour contrast with no luminance contrast). We first investigated whether depth from texture gradients disappears at isoluminance. The percept remained unaltered. Further experiments revealed that certain colour gradients (at isoluminance) markedly affected the perceived depth. A gradient in saturation (e.g. red-to-grey) was particularly effective, whereas a red-green hue gradient had no effect on perceived slant. We concluded that colour information can be used by the visual system to encode depth, especially in situations where the visual environments is rich in cues which could be used to signal depth in this way.

A survey of nine years heart transplantation at Erasme Hospital, University of Brussels.

Between March 1982 and March 1991, 225 heart transplantations (HTx) have been performed in 220 patients suffering end stage cardiac disease. Thirteen percent were females and 87% were males. Age range was from 5 to 68 years. The underlying cardiac disease was ischemic cardiopathy in 51.5%, congestive dilated cardiomyopathy in 42%, valvular cardiomyopathy in 3.5%, toxic myocarditis (post-adriamycin) in 1.5% and chronic rejection in 2.5% (retransplantation). Selection of the recipients was done following the currently well established criteria also taking into account the absolute major contraindications for HTx. Due to the still increasing demand of donor organs, currently donor age has been extended up to 50 years for male and 55 years for female donors. One quarter of the grafts were harvested on site in our institution, two other quarters were harvested somewhere else in Belgium and the last quarter provided by other countries cooperating with Eurotransplant. All patients have undergone orthotopic cardiac transplantation using the standard Lower and Shumway technique. Immunosuppression protocols have changed four times throughout the years. Nevertheless all were based on the use of Ciclosporine variously combined with other current immunosuppressive drugs. Rejection monitoring relied on routine endocardiac biopsy and was diagnosed according to the Billingham criteria. The in-hospital mortality is currently 11%. Infection, early right heart graft failure and acute rejection were the leading causes of death. The major causes of early morbidity were several curable infections, reversible rejection episodes, transient acute renal failure and controllable arterial hypertension. Among the survivors followed for at least one month up to nine years, half of late mortality was caused by chronic rejection followed by infection, sudden death, metabolic disorders, stroke and malignancy. Late morbidity involves cases of mild coronary graft diseases, biological renal insufficiency, some degree of arterial hypertension, dislipidemia. Current actuarial survival rate is 87% at one year, 76% at 5 years up to 9 years. Our experience confirms that HTx represents today and effective therapy for selected patients suffering end stage cardiac disease.

Brucella endocarditis: the role of combined medical and surgical treatment.

Brucella endocarditis, although a rare complication of brucellosis, is the main cause of death related to this disease. This report describes a case of aortic endocarditis due to Brucella abortus in an elderly farmer with known aortic stenosis. Urgent valve replacement was performed because of progressive heart failure despite appropriate antimicrobial treatment. The infection was cured with trimethoprim-sulfamethoxazole and rifampin given for 3 months after surgery. A review of the literature reports on the 38 other cases of cured brucella endocarditis made clear the need for combined antimicrobial treatment and surgical valve replacement.

[Traumatic rupture of the isthmus of the thoracic aorta (midterm results in a series of 15 cases)]. / Rupture traumatique de l'isthme de l'aorte thoracique (résultats à moyen terme sur une série de quinze cas).

The authors present a series of 15 cases of traumatic disruption of the aortic isthmus. There were 9 cases of acute rupture and 6 of chronic rupture. All the patients have been operated on. Different technics was used to protect the viscera during aortic cross-clamping, partial E.C.C. in 9 cases, clamp-repair technic in 4 cases and a GOTT shunt in 2 cases. 4 patients died in the first thirty days (3 acute and 1 chronic). 2 cases of paraplegia was observed. All the patients have been reviewed after a mean follow-up of 36 months and remain well but one who is still paraplegic. Surgical repair is mandatory in acute and aortic disruption with a great attention to the associated injuries.

Absence of cardio-depressant effects of CGP 17582 B, a new beta-blocking agent, in patients after coronary surgery.

The hemodynamic effects of CGP 17582 B, a new cardio-selective beta-blocking agent with moderate intrinsic sympathomimetic activity and minimal effects on myocardial contractility, were studied in patients after cardiac surgery for coronary artery bypass graft. Each patient had been treated preoperatively with beta-blocking agents and had a cineangiographic left ventricular ejection fraction between 40 and 60%. Fourteen patients were randomized to receive either 10 mg of propranolol or 50 mg of CGP 17582 B orally. Both drugs resulted in a significant and a similar decrease in heart rate. However, this was associated with a significant decrease in stroke volume after propranolol but not after CGP 17582 B, so that cardiac output significantly decreased only after propranolol. Thermodilution right ventricular ejection fraction significantly decreased after propranolol but not after CGP 17582 B. Each drug was well tolerated during the 10 following days and the recovery was uneventful in each patient. These results indicate that CGP 17582 B is a promising beta-blocking agent susceptible to reduce heart rate without altering cardiovascular function after cardiac surgery.

[Functional non-invasive cardio-respiratory evaluation a month and a year after orthotopic heart transplantation]. / Evaluation fonctionnelle cardio-respiratoire non invasive un mois et un an après transplantation cardiaque orthotopique.

Cardio-respiratory stress tests of 14 patients, performed one month and one year after orthotopic heart transplant, are compared in order to demonstrate the functional and metabolic improvements of their adaptation to stress. At maximal stress, we note a 33 p. cent increase of the oxygen consumption (p 0.001), an 11 p. cent increase of the heart rate (p 0.025) and an 18 p. cent increase of the systolic arterial pressure (p 0.005). Respiratory quotients and respiratory equivalent for oxygen are significantly lower (p 0.008) while there was no significant variation of ventilation/minute, respiratory rate, and the normal capacity. At the sub-maximal level, the only significant differences observed are the decrease of the respiratory quotient (p 0.01), the ventilation/minute (p 0.025), the respiratory equivalent for oxygen (p 0.005) and the respiratory rate (p 0.03). The improvement of the physical condition observed in heart transplants seems related to a better peripheral adaptation to stress (lower respiratory quotients, reflection of the decreased demand on anaerobic metabolism) permitting a lesser demand on the ventilatory response to stress.