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C Dubois

Publications and source records attributed to C Dubois.

At least 37 records · Page 2Linked to original sources
PubMed2001

The lipase C-terminal domain. A novel unusual inhibitor of pancreatic lipase activity.

In vertebrates, dietary fat digestion mainly results from the combined effect of pancreatic lipase, colipase, and bile. It has been proposed that in vivo lipase adsorption on oil-water emulsion is mediated by a preformed lipase-colipase-mixed micelle complex. The main lipase-colipase binding site is located on the C-terminal domain of the enzyme. We report here that in vitro the isolated C-terminal domain behaves as a potent noncovalent inhibitor of lipase and that the inhibitory effect is triggered by the presence of micelles. Lipase inhibition results from the formation of a nonproductive C-terminal domain-colipase-micelle ternary complex, which competes for colipase with the active lipase-colipase-micelle ternary complex, thus diverting colipase from its lipase-anchoring function. The formation of such a complex has been evidenced by molecular sieving experiments. This nonproductive complex lowers the amount of active lipase thus reducing lipolysis. Preliminary experiments performed in rats show that the C-terminal domain also behaves as an inhibitor in vivo and thus could be considered a potential new tool for specifically reducing intestinal lipolysis.

Animals↗
PubMed2001

Repair of anterior leaflet prolapse by papillary muscle repositioning: a new surgical option.

BACKGROUND: Although mitral valve repair is considered the gold standard for treating mitral regurgitation, anterior leaflet prolapse may still remain a challenging problem. This challenge is even greater for posterior commissural prolapse. We have used papillary muscle repositioning to treat anterior leaflet prolapse and suggest it as an alternative technique for all other methods previously described. METHODS: From 1989 to 1999 we performed 253 mitral valve repairs, among which 132 involved anterior leaflet prolapse. In this population there were two groups: group I (n = 92) treated with papillary muscle repositioning and group II (n = 40) treated with chordal shortening. There was no statistical difference between the two groups concerning age, functional class, and left ventricular function. Etiology was similar in both groups, a degenerative process being predominant. At echocardiography, regurgitation was graded 3.4/4 in both groups. There was no statistical difference concerning preoperative ejection fraction, end-systolic and end-diastolic left ventricular diameter. RESULTS: There were one in-hospital death in group I and two deaths in group II not related to mitral valve repair. Mean follow up is 36.4 +/- 29.2 months in group I and 70.5 +/- 9.5 months in group II. No patient was lost to follow-up. Mean regurgitation at follow-up was 0.75 +/- 0.67 in group I and 0.8 +/- 0.8 in group II (p = not significant). There was no statistical difference between the two groups concerning postoperative ejection fraction, end-systolic and end-diastolic left ventricular diameter. There was no late cardiac death in either group and there were no thromboembolic events. Actuarial survival rate is 98.9% and 96.3% in group I and 92.5% and 88.1% in group II at 3 and 8 years, respectively. CONCLUSIONS: Therefore, we conclude that papillary muscle repositioning is a safe technique that provides excellent results at mid-term follow-up and facilitates treatment of anterior leaflet prolapse.

Aged↗
PubMed2001

[Professional outcome of reflex sympathetic dystrophy].

OBJECTIVE: In spite of physical medicine and rehabilitation care, post-traumatic reflex sympathetic dystrophy can be at the origin of articular deficiency, which decrease the capacity to return to work. The aim of this study is to know the professional future of patients who present post-traumatic reflex sympathetic dystrophy. MATERIAL AND METHOD: Eighteen months prospective study, carried out from patients in age to work, hospitalized in physical medicine and rehabilitation unit for ostéo-articular traumatism complicated by reflex sympathetic dystrophy. Description of the population and comorbidity factors preventing professional resumption. Determination of the duration of medical certificate and the modalities of professional resumption. RESULTS: From 16 patients in age to work, only 12 were able to resume a full time profession with an average period of 10.5 months +/- 5. The importance of the, the distale articular location of reflex sympathetic dystrophy (wrist - hand, ankle - foot), the association with a comorbidity such as chronic alcoholism represent pejorative factors of working resumption. Organizations of workstation are often necessary in six cases over eight, if the job is not sedentary. In the most complicated cases, inaptitudes in the work are pronounced with demand of professional reclassifying. CONCLUSION: Post-traumatic reflex sympathetic dystrophy represents a real challenge for the rehabilitation team, to minimize deficiencies and to help the patient to become again a worker.

Activities of Daily Living↗
PubMed2001

Respiratory function in adult mice lacking the mu-opioid receptor: role of delta-receptors.

Mice lacking the mu-opioid receptor (MOR) provide a unique model to determine whether opioid receptors are functionally interactive. Recent results have shown that respiratory depression produced by delta-opioid receptor agonists is suppressed in mice lacking the mu-opioid receptor. Here we investigated the involvement of mu- and delta-opioid receptors in the control of ventilation and mu/delta receptor interactions in brainstem rhythm-generating structures. Unrestrained MOR-/- and wild-type mice showed similar ventilatory patterns at rest and similar chemosensory responses to hyperoxia (100% O2), hypoxia (10% O2) or hypercapnia (5%CO2-95%O2). Blockade of delta-opioid receptors with naltrindole affected neither the ventilatory patterns nor the ventilatory responses to hypoxia in MOR-/- and wild-type mice. In-vitro, respiratory neurons were recorded in the pre-Bötzinger complex of thick brainstem slices of MOR-/- and wild-type young adult mice. Respiratory frequency was not significantly different between these two groups. The delta2 receptor agonist deltorphin II (0.1-1.0 microM) decreased respiratory frequency in both groups whereas doses of the delta1 receptor agonist enkephalin[D-Pen2,5] (0.1-1.0 microM) which were ineffective in wild-type mice significantly decreased respiratory frequency in MOR-/- mice. We conclude that deletion of the mu-opioid receptor gene has no significant effect on ensuing respiratory rhythm generation, ventilatory pattern, or chemosensory control. In MOR-/- mice, the loss of respiratory-depressant effects of delta2-opioid receptor agonists previously observed in vivo does not result from a blunted response of delta receptors in brainstem rhythm-generating structures. These structures show an unaltered response to delta2-receptor agonists and an augmented response to delta1-receptor agonists.

Analgesics, Opioid↗
PubMed2001

Dietary cholesterol is secreted in intestinally derived chylomicrons during several subsequent postprandial phases in healthy humans.

BACKGROUND: The process of intestinal absorption and chylomicron resecretion of dietary cholesterol in humans is poorly understood. OBJECTIVE: The present study aimed to test the hypothesis that dietary cholesterol ingested during a given meal is resecreted into chylomicrons (and plasma) during several subsequent postprandial periods. DESIGN: Seven healthy subjects ingested 3 comparable mixed test meals (at 0, 8, and 24 h) containing a given amount of fat (49 g) and cholesterol (157 mg); blood samples were taken 3 and 6 h after each test meal and 48 and 72 h after the beginning of the experiment. Heptadeuterated dietary cholesterol was present in the first test meal only, enabling its specific determination with use of gas chromatography-mass spectrometry. Chylomicrons, LDL, and HDL were isolated and lipids were quantified. RESULTS: In apolipoprotein B-48-containing chylomicrons, deuterated cholesterol concentrations were moderate after the first meal (1.3 x 10(-4) mmol/L), reached a maximum after the second meal (2.4 x 10(-4) mmol/L), and were still elevated after the third meal (1.7 x 10(-4) mmol/L). In plasma, LDL and HDL cholesterol enrichment in deuterated cholesterol was lower than in chylomicrons and plateaued after 24--48 h. Estimates of newly secreted exogenous deuterated cholesterol in chylomicrons indicate that 30.7%, 55.2%, and 14.1% of the total was secreted after the first, second, and third meals, respectively. CONCLUSION: Ingested dietary cholesterol is secreted by the small intestine in chylomicrons into the circulation during > or =3 subsequent postprandial periods in healthy humans. This likely results from a complex multistep intestinal processing of cholesterol with dietary fat as a driving force.

Adult↗
PubMed2001

[Prognosis and risk evaluation of postoperative coronary patients (PERISCOP). Methodology and study population characteristics].

The aim of the PERISCOP study was to evaluate the predictive value of cardiological investigations performed after recent coronary bypass surgery with regards to cardiac event and mortality at one year. The treatment of lipid abnormalities was also analysed. This first article describes the methodology and patient characteristics at inclusion. This prospective national multicenter trial included 2065 patients (86% men) with an average age of 63.1 +/- 9.9 years. The number of diseased vessels was 2.6 +/- 0.6. Preoperative left ventricular function was normal (ejection fraction 60 +/- 13%). Revascularisation was complete in 73% of cases (22% of arterial grafts). The cardiological investigations were performed at Day 20 +/- 10 after surgery. The duration of exercise on stress testing was 429 +/- 170 seconds. It was positive or doubtful in 9% of cases. Ventricular arrhythmias were observed in 6.5% of cases. The blood pressure response was abnormal in 6% of cases. Holter monitoring showed a median number of ventricular extrasystoles over 24 hours of 44. Three per cent of patients had one episode of ventricular tachycardia and 7% had ischaemic episodes. The echocardiographic index of segmental contractility was on average 1.75 (ejection fraction: 52.6%). The lipid analysis performed at one month, under lipid therapy in 34% of cases, showed a total cholesterol level at 1.91 +/- 0.10 g/l, an LDL-cholesterol of 1.27 +/- 0.08 g/l. The therapeutic target (LDL-cholesterol < 1 g/l) was attained in 46% of cases with treatment and in 18% of cases without treatment.

Aged↗
PubMed2000

Supralesional and sublesional bone mineral density in spinal cord-injured patients.

This study was performed to evaluate supra- and sublesional bone mineral density (BMD) in spinal cord-injured (SCI) patients after 1 year postinjury, and to correlate the BMD to the neurological level; to correlate the sublesional demineralization to functional parameters (duration postinjury, duration of the initial bedrest); and to assess the role of classic methods of prevention such as walking or standing. Thirty-one SCI patients, all male, were studied vs. 31 controls (age matched). The mean age of the population was 36 years (range 18-60 years). Eleven were tetraplegic and 20 were paraplegic. Twenty-six patients dysplayed a complete motor lesion. The BMD was measured by dual-photon absorptiometry on the lumbar spine and on the femoral neck, and the bone mineral content (BMC) on whole-body scans. Particular attention was paid to the distal femur and proximal tibia upper third. Blood samples and urine samples included phosphocalcic parameters, with determination of urinary hydroxyproline and deoxypyridinoline. SCI patients showed a decrease of sublesional BMD of 41% in comparison with controls. This loss of bone mass is higher at the distal femur (-52%) and proximal tibia (-70%), which are the most common sites of fracture. The degree of demineralization for the lumbar spine, the pelvis, and the lower limbs is independent of the neurological level. The duration of acute posttraumatic immobilization (mean 43.3 days) and the time postinjury increase the loss of bone mass for lower limbs (p = 0.04) and particularly for the proximal tibia (p = 0.02). The study of biomechanical stress (i.e., standing, walking, sitting) does not influence the sublesional BMC. This study underlines the major role of the neurological lesion on the decrease of sublesional BMC in SCI patients and the absence of influence of biomechanical stress.

Absorptiometry, Photon↗
PubMed2000

Recurrent coronary stent thrombosis.

A 63-year-old woman with an acute anterior myocardial infarction was treated with primary stent implantation. The absence of coronary artery stenosis and an haematocrit of 58 were indicative of a myeloproliferative disorder and the diagnosis of polycythaemia vera (Vaquez' disease) was confirmed by bone marrow aspiration. The patient had a re-infarction 8 days later. A rescue percutaneous angioplasty was performed for stent thrombosis after unsuccessful thrombolysis. A few hours after sheath removal, a femoral artery thrombosis at the puncture side needed urgent thrombectomy. Finally, a second re-infarction occurred, followed by an irreversible cardiac arrest. Stent thrombosis is a difficult-to-treat complication in patients with polycythaemia vera. If this haematologic disorder is known, primary stent implantation for acute myocardial infarction may not be the first choice in these patients.

Angioplasty, Balloon, Coronary↗
PubMed2000

Role and expression of CD40 on human retinal pigment epithelial cells.

PURPOSE: To examine the CD40 costimulatory molecule expression on normal resting or activated adult human retinal pigment epithelium (hRPE) cells and to evaluate its role as an activation molecule considering the potential antigen presentation functions of hRPE cells. METHODS: Expression of HLA-DR and costimulatory (CD40, B7.1, B7.2, CD54, and CD58) molecules on hRPE cells was analyzed by flow cytometry. CD40 triggering was performed using soluble CD40L or cocultures with CD40L transfected fibroblasts. Interleukin (IL)-6, -8, -10, and -12 secretions were measured by enzyme-linked immunosorbent assay. Antigen presentation function of hRPE cells was assessed by coculturing hRPE cells with allogeneic T cells. T-cell proliferation was measured by [(3)H]-thymidine incorporation, and T-cell apoptosis by measurement of caspase-3 activity. RESULTS: Interferon (IFN)gamma-activated hRPE cells expressed CD40, but not B7.1 or B7.2. Although interferongamma enhanced IL-6 and IL-8 production, CD40 triggering of IFNgamma-activated hRPE cells did not induce IL-12 secretion. hRPE cells did not stimulate allogeneic resting T cells and downregulated phytohemagglutinin-activated allogeneic T cells via a cell-to-cell contact-dependent mechanism. Some induction of apoptosis was detected. CONCLUSIONS: CD40 is expressed on IFNgamma-activated hRPE cells. Its ligation leads to an increased production of IL-6 and IL-8 but fails to induce B7.1 or B7. 2 expression, or to induce IL-12 secretion. Accordingly, hRPE cells do not activate allogenic T cells but inhibit T-cell proliferation, partly through induction of apoptosis. These results suggest that hRPE cells could be implicated more in a deviant antigen presentation. If the exact molecular mechanisms are unclear, it is likely that CD40-CD40L interaction could play a role in this process.

Animals↗
PubMed2000

Surgery of acute type A dissection: what have we learned during the past 25 years?

Every acute dissection involving the ascending aorta (Stanford type A) must undergo emergency surgical repair. However, the surgical techniques must vary according to the clinical presentation of the patients or the anatomical patterns observed. Furthermore, surgery is generally difficult because of the poor condition of the aortic tissues. To reduce those difficulties many technical artifacts have been described. In 1977, we proposed the use of gelatin-resorcin-formalin (GRF) biological glue to reinforce the suture areas. From January 1977 to July 1999, 212 patients (pts) (152 males and 60 females) aged from 15 to 80 years (mean age: 54 +/- 11 years) underwent an emergency operation for type A aortic dissection. One-hundred-seventy-eight pts (84%) were operated on within 4 hours after being referred to the hospital. Twenty-eight pts (13.2%) had Marfan's syndrome. In 44 patients (20.7%), the aortic valve was replaced either independently (6 cases--2.8%) or by means of a composite graft (38 cases--17.9%). Because of the location of the intimal tear, the aortic replacement was extended to the transverse arch in 61 pts (28.7%). Hospital mortality amounts to 21.6% (46 pts), 25% in pts with arch replacement and 19.4% in pts without arch replacement (n.s). Analysis of hospital mortality demonstrates that the main causes of death were cardiac tamponade, neurologic disorders and visceral malperfusion. One-hundred-sixty-six pts were discharged and surveyed from 5 months to 22 years postoperatively (mean follow-up: 85 +/- 66 months). During this period of time, 25 pts (15%) had to be reoperated for a total of 33 reoperations. Seven pts (28%) died at reoperation. Using univariate analysis, the presence of Marfan's syndrome (p < 0.05) and absence of arch replacement (p < 0.02) were determinant risk factors for reoperation. Emergency (p < 0.01) and thoraco-abdominal replacement (p < 0.04) were determinant riskfactors for death at reoperation. The freedom from reoperation (Kaplan-Meier, CI: 95%) is 96% (90-98), 87% (79-92), 80% (70-88), 66% (51-78) at 1, 5, 10 and 15 years respectively. A total of 39 pts (24.3%) died during follow-up. The presence of Marfan's syndrome (p < 0.01), reoperation (p < 0.02), stroke (p < 0.05), and cardiac failure (p < 0.05) were determinant risk factors of late mortality. The late survival rate (K-M. C.I.: 95%), including hospital mortality, is 71% (64-77), 66% (58-73), 56% (47-64), 46% (36-56), 37% (28-44) at 1, 10, 15 and 20 years, respectively. From our experience extending over more than 23 years, GRF glue has proved to be extremely useful, making the procedure much easier and safer. Nevertheless, many factors are of importance in the pre-, intra- and postoperative management of the patients. Cardiac tamponade and visceral malperfusion must be properly diagnosed and treated. During aortic repair, the main intimal tear must be resected. The transverse arch must be checked and replaced whenever necessary. The aortic valve should be preserved whenever possible. During CPB, perfusing the aorta in the regular antegrade manner seems to dramatically reduce the rate of malperfusion. The quality of the first emergency operation seems to have a major influence on the late results, especially concerning the rate of late reoperations and aortic ruptures. However, those late results depend also on the patient's basic condition, particularly in Marfan patients.

Acute Disease↗
PubMed1999

Antegrade cerebral perfusion with cold blood: a 13-year experience.

BACKGROUND: In 1986 we introduced the technique of antegrade selective perfusion of the brain with cold blood during surgery of the aortic arch. METHODS: Between January 1984 and March 1998, 171 patients (118 males and 53 females) aged 25 to 83 years (mean 56.5 +/- 17), underwent replacement of the transverse aortic arch with the aid of cold blood antegrade selective perfusion. One hundred twenty two patients (71.3%) with chronic lesions were operated on electively; 49 patients (28.6%) were operated on urgently for acute aortic dissection (42 patients) or for a ruptured chronic aneurysm (7 patients). Fifty-one patients (29.8%) had previously undergone a surgical procedure on the thoracic aorta. Mean duration of cardiopulmonary bypass was 121 minutes (range: 65-248); mean duration of cerebral perfusion was 60 minutes (range: 15-90), and mean duration of systemic circulatory arrest circuit was 32 minutes (range: 10-57). The electroencephalogram, routinely recorded, showed disappearance of electrical activity in a mean of 9 minutes (range: 3-16) initial return of electrical activity after a mean of 12 minutes (range: 1-35) and normalization in a mean time of 66 minutes. RESULTS: All patients but 7 (4%) showed signs of normal awakening within 8 hours postoperatively. Six patients (3.5%) had fatal neurologic complications, and 16 patients (9.3%) had a non-fatal neurologic complications. Twenty-nine patients (16.9%) died during the postoperative hospital course. There was a significant difference between patients aged less than 60 years (9%) and patients older than 60 years (mortality rate 26.4%, p < 0.02). There was also a significant difference between patients undergoing an isolated replacement of the arch, and those in whom the replacement was extended to the descending aorta in whom mortality was 36.4% (chi2, p < 0.02). Lesion and gender had no significant influence on the outcome of the patients, nor had the duration of cardiopulmonary bypass, circulatory arrest, and cerebral perfusion. In particular, no correlation could be established between the duration of cerebral perfusion and the occurrence of neurologic complications. CONCLUSION: The clinical results obtained throughout this experience have demonstrated that selective antegrade cerebral perfusion with cold blood provides excellent protection during surgery of the transverse aortic arch. In addition, it avoids the use of deep hypothermia and prolonged cardiopulmonary bypass and does not limit the time allowed to perform the aortic repair. In our opinion it is the technique of choice, especially in frail patients or those requiring a long and difficult procedure.

Adult↗
PubMed1999

Surgery for acute type A aortic dissection: the Hopital Foch experience (1977-1998).

BACKGROUND: In 1977, we proposed the use of gelatin-resorcinol-formol (GRF) biological glue during surgery for acute type A aortic dissection. METHODS: From January 1977 to March 1998, 204 patients (146 men and 58 women) aged from 15 to 79 years (mean 54 +/- 11) underwent emergency operation for type A aortic dissection in our institution. One hundred sixty-five patients (84%) were operated on within 48 h after the onset of symptoms. Twenty-eight patients (13.7%) had Marfan's syndrome. In 43 patients (23%), the aortic valve was replaced either independently (6, 3%) or by means of a composite graft (37, 18.1%). Because of the location of the intimal tear, aortic replacement included the transverse arch in 60 patients (29.4%). RESULTS: Hospital mortality was 21% (39 patients): 25% in patients with arch replacement and 19.4% in patients without arch replacement (ns). One hundred sixty-one patients were discharged and followed from 2 months to 21 years postoperatively (mean 85 +/- 66 months). During this interval, 25 patients (15.5%) required reoperation for a total of 33 reoperations. Seven patients (28%) died at reoperation. Upon univariate analysis, presence of Marfan's syndrome (p < 0.05) and absence of arch replacement (p < 0.02) were risk factors for reoperation. Emergency operation (p < 0.01) and thoracoabdominal replacement (p < 0.04) were risk factors for death at reoperation. The actuarial freedom from reoperation (Kaplan-Meier, confidence interval 95%) is 96.1% (90.9%-98.2%) at 1 year, 87.6% (79.8%-92.7%) at 5 years, 80.9% (70.8%-88.1%) at 10 years, and 66.4% (51.1%-78.9%) at 15 years. A total of 39 patients (24.3%) died during follow-up. The presence of Marfan's syndrome (p < 0.01), reoperation (p < 0.02), stroke (p < 0.05), and cardiac failure (p < 0.05) were risk factors for late mortality. The actuarial late survival including hospital mortality is 71.5% (64.3%-77.8%) at 1 year, 66% (58.3%-73%) at 5 years, 56.4% (47.7%-64.7%) at 10 years, and 46.3% (36.4%-56.5%) at 15 years. CONCLUSIONS: The GRF glue has proven extremely useful during emergency initial surgery for acute type A dissection, making the procedure much easier and safer. As a result of this operative improvement, the use of the GRF glue seems to have had a beneficial influence on late results, but these also depend upon the patient's basic condition.

Adolescent↗
PubMed1999

Cardiac metaiodobenzylguanidine uptake in patients with moderate chronic heart failure: relationship with peak oxygen uptake and prognosis.

OBJECTIVES: This prospective study was undertaken to correlate early and late metaiodobenzylguanidine (MIBG) cardiac uptake with cardiac hemodynamics and exercise capacity in patients with heart failure and to compare their prognostic values with that of peak oxygen uptake (VO2). BACKGROUND: The cardiac fixation of MIBG reflects presynaptic uptake and is reduced in heart failure. Whether it is related to exercise capacity and has better prognostic value than peak VO2 is unknown. METHODS: Ninety-three patients with heart failure (ejection fraction <45%) were studied with planar MIBG imaging, cardiopulmonary exercise tests and hemodynamics (n = 44). Early (20 min) and late (4 h) MIBG acquisition, as well as their ratio (washout, WO) were determined. Prognostic value was assessed by survival curves (Kaplan-Meier method) and uni- and multivariate Cox analyses. RESULTS: Late cardiac MIBG uptake was reduced (131+/-20%, normal values 192+/-42%) and correlated with ejection fraction (r = 0.49), cardiac index (r = 0.40) and pulmonary wedge pressure (r = -0.35). There was a significant correlation between peak VO2 and MIBG uptake (r = 0.41, p < 0.0001). With a mean follow-up of 10+/-8 months, both late MIBG uptake (p = 0.04) and peak VO2 (p < 0.0001) were predictive of death or heart transplantation, but only peak VO2 emerged by multivariate analysis. Neither early MIBG uptake nor WO yielded significant insights beyond those provided by late MIBG uptake. CONCLUSIONS: Metaiodobenzylguanidine uptake has prognostic value in patients with wide ranges of heart failure, but peak VO2 remains the most powerful prognostic index.

3-Iodobenzylguanidine↗
PubMed1999

Long term results of mitral valve repair: posterior papillary muscle repositioning versus chordal shortening.

OBJECTIVE: Mitral valve repair is considered as the gold standard to treat mitral regurgitation. However anterior leaflet prolapse in the posterior paramedial and paracommissural area remains a challenging problem. Indeed several elongated chordae may arise from a single posterior papillary muscle head which does not allow safe separate chordal shortening (CS). We therefore suggest use of papillary muscle repositioning in such cases. METHODS: In a cohort of 180 mitral valve repair performed between 1989 and May 1998, we have retrospectively studied 100 consecutive patients who underwent anterior leaflet repair in the posterior paramedial and paracommissural area. Group I (n = 60) had posterior papillary muscle repositioning (PPMR) and group II (n = 40) had CS. There was no statistical difference between the two groups concerning age, functional class and left ventricular function. Etiology was similar in both groups, degenerative process being predominant. At echocardiogram, regurgitation was graded 3.4/4 in both groups. There was no statistical difference concerning preoperative ejection fraction, end systolic and end diastolic left ventricular diameter. RESULTS: There were no in-hospital deaths in group I and two deaths in group II not related to mitral valve repair. Mean follow up is 26.4 +/- 24.2 months in group I and 46.1 +/- 28.8 months in group II. No patient was lost to follow up. Severe mitral regurgitation was not observed. Mean regurgitation at follow up was 0.8 +/- 0.7 in group I and 0.8 +/- 0.8 in group II (P = n.s.); there was no statistical difference between the two groups concerning postoperative ejection fraction, end systolic and end diastolic left ventricular diameter. There was no late cardiac death in either group and there were no thromboembolic events. Actuarial survival rate is 100% and 94.4% in group I and 92% and 84.4% in group II at 2 and 6 years, respectively. CONCLUSION: This experience shows that PPMR provides as good longterm results as CS to repair anterior leaflet prolapse in posterior paramedial and paracommissural area with lesser morbidity and mortality.

Adult↗
PubMed1998

Engagement of T cell receptor triggers its recruitment to low-density detergent-insoluble membrane domains.

T-cell receptors (TCRs) upon binding to peptide-MHC ligands transduce signals in T lymphocytes. Tyrosine phosphorylations in the cytoplasmic domains of the CD3 (gammadeltaepsilon) and zeta subunits of the TCR complex by Src family kinases initiate the signaling cascades via docking and activation of ZAP-70 kinase and other signaling components. We examined the role of the low-density detergent-insoluble membranes (DIMs) in TCR signaling. Using mouse thymocytes as a model, we characterized the structural organization of DIMs in detail. We then demonstrated that TCR engagement triggered an immediate increase in the amount of TCR/CD3 present in DIMs, which directly involves the engaged receptor complexes. TCR/CD3 recruitment is accompanied by the accumulation of a series of prominent tyrosine-phosphorylated substrates and by an increase of the Lck activity in DIMs. Upon TCR stimulation, the DIM-associated receptor complexes are highly enriched in the hyperphosphorylated p23 zeta chains, contain most of the TCR/CD3-associated, phosphorylation-activated ZAP-70 kinases and seem to integrate into higher order, multiple tyrosine-phosphorylated substrate-containing protein complexes. The TCR/CD3 recruitment was found to depend on the activity of Src family kinases. We thus provide the first demonstration of recuitment of TCR/CD3 to DIMs upon receptor stimulation and propose it as a mechanism whereby TCR engagement is coupled to downstream signaling cascades.

Animals↗
PubMed1998

Near fatal respiratory distress following massive ether intravenous injection.

To the best of our knowledge, no case of ether-induced acute respiratory distress syndrome (ARDS) has been published as yet. A 36-year-old female developed pneumonitis which showed all the characteristics of a chemical-associated ARDS due to intravenous self-administration of ether: the hemodynamic investigation demonstrated a normal blood flow pattern with low left-heart filling pressure while the anteroposterior roentgenogram evidenced disseminated bilateral lung edema. Advanced symptomatic respiratory support including inhaled nitric oxide and steroidal anti-inflammatory use was the treatment of choice.

Adult↗
PubMed1998

[Surgical treatment of acute dissection of the ascending aorta (20 years experience)].

PURPOSE: In 1977, the use of gelatine-resorcine-formaline (GRF) biological glue during surgery of acute type A aortic dissection was proposed. The present study retrospectively analyses the late results obtained with this adjunct in an experience extending over a 20-year period. PATIENTS AND METHODS: From January 1977 to July 1997, 193 patients (139 males and 54 females) aged from 15 to 79 years (mean age: 53 +/- 14 years) underwent an emergency operation for type A aortic dissection in our institution. All patients suffering from acute type A dissection and 162 (84%) were operated on within 48 hours after the onset of symptoms. Twenty-eight patients (15.2%) had Marfan's syndrome. In all patients the ascending aorta was replaced and the aortic stumps were reinforced with the GRF glue. In 43 patients (22.2%), the aortic valve was replaced either independently (5 cases-2.5%) or by means of a composite graft (35 cases-19.5%). Recently three patients underwent a complete replacement of the ascending aorta and coronary reimplantation with preservation of the native aortic valve. Because of the location of the intimal tear, the aortic replacement was extended to the transverse arch in 58 patients (30%). RESULTS: Hospital mortality amounted to 21% (40 patients) (22.8% in patients with arch replacement and 20.3% in patients without arch replacement) (ns). The survivors were surveyed from 2 months to 20 years post-operatively (cumulative follow-up: 856 pt/years, mean follow-up: 85 +/- 66 months). During this period of time, 23 patients (15%) had to be reoperated on for a total of 29 procedures. Six of those patients (26%) died at reoperation. At univariate analysis, presence of Marfan's syndrome (P < 0.05) and absence of arch replacement (P < 0.02) were determinant risk factors for reoperation. Emergency (P < 0.01) and thoraco-abdominal replacement (P < 0.04) were determinant risk-factors of death at reoperation. The actuarial freedom from reoperation (Kaplan-Meier, CI: 95%) was: 96.5% (90.9-98.2), 87.6% (79.8-92.7), 80.9% (70.8-88.1), 66.4% (51.1-78.9) at one, 5, 10 and 15 years, respectively. A total of 36 patients (27.7%) died during follow-up. Presence of Marfan's syndrome (P < 0.01), reoperation (P < 0.02), stroke (P < 0.05), cardiac failure (P < 0.05) were determinant risk factors of late mortality. The actuarial late survival rate (Kaplan-Meier. CI: 95%), including hospital mortality, was: 71.5% (64.3-77.8), 66% (58.3-73), 56.4% (47.7-64.7), 46.3% (36.4-56.5) at one, 5, 10 and 15 years. CONCLUSION: The GRF glue has proved to be extremely useful during initial emergency surgery for acute type A dissection, making the procedure much easier and safer. Through this operative improvement, the use of the GRF glue seems to have a beneficial influence on the late results which, however, depend mainly on the patient's basic condition.

Adolescent↗