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Biomedical subjects

J Perron

Publications and source records attributed to J Perron.

At least 19 recordsLinked to original sources
PubMed2006

Expression of bone-regulatory proteins in human valve allografts.

OBJECTIVE: To test the hypothesis that valve allograft (VA) calcification results from an ossification process in which bone-regulatory proteins are expressed. METHODS: 15 VA that were explanted at the time of surgery for dysfunction were studied. VA were analysed and compared with normal aortic valves (n = 20). RESULTS: All the VA (5 aortic, 10 pulmonary) exhibited heavy calcification and important fibrosis. Immunohistochemistry studies showed that the bone-specific transcription factor Cbfa-1 was expressed by stromal cells. Bone alkaline phosphatase was expressed in calcified regions. Immunostaining for alpha smooth muscle (alpha-SM) actin was increased in VA compared with normal valves and in 6 of the 15 valves formed cellular clusters close to the calcified nodules. In VA osteopontin and osteonectin were expressed by stromal cells, whereas osteocalcin was closely associated with the calcified regions. Furthermore, analysis of the bone-regulatory proteins that control bone resorption showed that receptor activator of nuclear factor kappaB ligand (RANKL), receptor activator of nuclear factor kappaB (RANK) and osteoprotegerin (OPG) were differentially expressed in calcified VA and normal valves. Normal valve leaflets expressed OPG, whereas OPG expression was absent or faint in calcified VA. RANKL and RANK were not detected in normal valves, whereas calcified VA expressed RANKL and RANK. CONCLUSION: These data suggest that calcification of VA results from an ossification process, which relies on tight control of bone-regulatory protein expression. The expression pattern of the RANKL/RANK/OPG system suggests that it may have a regulatory role not only in osteoclastogenesis but also in the calcification of human VA.

Actins↗
PubMed2005

Which biologic valve should we select for the 45- to 65-year-old age group requiring aortic valve replacement?

OBJECTIVE: The diversity of biologic valves available to replace the aortic valve renders selection difficult for the 45- to 65-year-old patient. To evaluate and compare the results of biologic valves in the 45- to 65-year-old patient, we reviewed our experience (1991-2004). METHODS: Three hundred thirty-two patients between 45 and 65 years old with isolated aortic valve disease had a biologic valve implanted: Freestyle valve in 140 patients, a homograft in 54 patients, a stented Mosaic or Perimount valve (stented xenograft) in 62 patients, and a Ross procedure in 76 patients. RESULTS: Perioperative mortality was comparable for all groups (Freestyle, 2.1%; homograft, 3.7%; stented xenograft, 3.2%; Ross procedure, 1.3%; P = .8). Echocardiographically determined valve performance at discharge was significantly enhanced in the Ross procedure and homograft groups (indexed effective orifice area: Freestyle, 0.9 +/- 0.3 cm 2 /m 2 ; homograft, 1.3 +/- 0.3 cm 2 /m 2 ; stented xenograft, 0.8 +/- 0.2 cm 2 /m 2 ; Ross procedure, 1.4 +/- 0.4; P < .0001; mean gradient: Freestyle, 12.0 +/- 6.6 mm Hg; homograft, 7.4 +/- 4.0 mm Hg; stented xenograft, 15.4 +/- 5.4 mm Hg; Ross procedure, 4.6 +/- 3.2 mm Hg; P < .0001). For all yearly follow-up, freedom from New York Heart Association class III or IV was comparable and greater than 95% for all groups. At 7 years, cardiac survival (homograft, 96.3% +/- 3.7%; Ross procedure, 90.6% +/- 6.3%; stented xenograft, 86.0% +/- 10.3%; Freestyle, 89.2% +/- 10.8%; P = .7) and freedom from reoperation (Ross procedure, 98.5% +/- 1.4%; homograft, 90.6% +/- 5.7%; Freestyle, 88.0% +/- 4.9%; stented xenograft, 90.0% +/- 8.0%; P = .4) were comparable. Freedoms from significant bleeding events, valve-related neurologic events, or endocarditis were comparable and greater than 95% for all groups. CONCLUSION: Type of aortic biologic valve for the 45- to 65-year-old patient does not affect midterm survival or valve-related morbidity. Thus the choice of biologic valve for the 45- to 65-year-old patient should be dictated by patient-surgeon preference, ease of implantation, and reoperation until longer comparative studies are available.

Age Factors↗
PubMed2004

[Infectious cellulitis and Shewanella alga septicemia in an immunocompetent patient].

BACKGROUND: Shewanella alga is a Gram-negative bacilla often found in water or soil. Clinical infections in humans are rare, with serious infections described generally in immunocompromised hosts. CASE REPORT: A 66 year-old man with a heel wound had developed, after numerous sea baths in the Atlantic ocean (Oleron island, France), an infectious cellulitis of the leg with Shewanella alga septicemia. Despite the absence of immunodeficiency in this patient, infectious cellulitis and septicemia occurred via a wound to the skin and contact with sea water. Healing was seen after treatment with cefotaxime, ciprofoxacin and gentamicin IV, relayed with ciprofloxacin and erythromycin. Shewanella alga was also susceptible to ticarcillin, piperacillin and ceftazidime but was resistant to ampicillin, amoxicilline-clavulanate, colistin, cyclines, fosfomycin and cefsulodin. No immunological anomaly was found. DISCUSSION: We report a case of infectious cellulitis with Shewanella alga septicemia. This has not previously been described in an immunocompetent patient. Antibiotic therapy must be longer than usual treatment for streptococcal erysipelas and first-line antibiotherapy with ampicillin alone may not be sufficient.

Acute Disease↗
PubMed2003

Does moderate mitral regurgitation impact early or mid-term clinical outcome in patients undergoing isolated aortic valve replacement for aortic stenosis?

OBJECTIVE: The early and mid-term impact of functional mitral regurgitation (MR) in patients undergoing isolated aortic valve replacement (AVR) for aortic stenosis remains unresolved. METHOD: Through our institutional databank, using a case-match study, we identified 58 patients with MR grades 0-1 and 58 patients with MR grades 2-3 (patients matched for sex, age, ejection fraction (EF), NYHA, diabetes, and CVA). Data were collected prospectively (mean duration of follow-up: 3.2 +/- 2.4 years). RESULTS: Perioperative morbidity (re-operation for bleeding, low cardiac output, CVA, renal failure) was comparable among groups. Difference in mortality between the two groups was non-significant (7.0 vs. 3.5%, P = 0.67 in groups MR 2-3 vs. 0-1, respectively). At early echocardiographic follow-up, 7/58 patients (12.1%) within group MR grades 0-1 increased their MR to grades 2-3; among which only two remained with MR grades 2-3 at mid-term follow-up. Within MR group 2-3, 18/58 (31.0%) remained with MR grades 2-3 among which 7/18 (38.9%) decreased of at least one grade at follow-up. Eight year actuarial survival was comparable in both groups: MR grades 0-1 = 60.9% vs. MR grades 2-3 = 55.0%; P = 0.1. Actuarial survival of patients with MR grades 2-3 postoperatively was similar to patients with MR grades 0-1 (MR grades 0-1 = 59.0%, MR grades 2-3 = 58.9%, P = NS). CONCLUSIONS: Presence of preoperative moderate functional MR (grades 2-3) in patients undergoing isolated AVR for aortic stenosis regresses in the majority of patients postoperatively and has no significant impact on perioperative morbidity or mortality, nor mid-term survival. Thus, moderate functional MR should be treated conservatively in the majority of patients especially in the elderly subjected to isolated AVR for aortic stenosis.

Aged↗
PubMed2001

Incidence and predictors of ARDS after cardiac surgery.

BACKGROUND: Severe pulmonary injury with the development of ARDS is a potential complication of cardiac surgery and cardiopulmonary bypass (CPB). STUDY OBJECTIVES: This retrospective, case-control study was designed to determine the incidence and mortality of ARDS after cardiac surgery and CPB, as well as to identify preoperative and perioperative predisposing factors of this complication. METHODS: Of 3,278 patients who underwent cardiac surgery and CPB between January 1995 and December 1998, 13 patients developed ARDS during the postoperative period. Each patient was matched with four or five control subjects who had the same type of surgery on the same day but did not develop postoperative respiratory complications. RESULTS: The incidence of ARDS was 0.4%, with an ARDS mortality of 15%. In the ARDS group, 38% had previous cardiac surgery, as compared to 3.5% in the control group (p < 0.002). During the postoperative period, ARDS patients received more blood products (4 +/- 5 vs 2 +/- 3; p < 0.01) and developed shock more frequently (31% vs 5%; p < 0.02) than patients in the control group. Multivariate regression analysis identified previous cardiac surgery, shock, and the number of transfused blood products as significant independent predictors for ARDS, with odds ratios of 31.5 (p = 0.015), 10.8 (p = 0.03), and 1.6 (p = 0.03), respectively. CONCLUSIONS: ARDS following cardiac surgery and CPB was a rare complication that carried a 15% mortality rate. Previous cardiac surgery, shock, and number of blood products received are important predicting factors for this complication.

Blood Transfusion↗
PubMed2001

A single center experience with the freestyle bioprosthesis: midterm results at the Québec Heart Institute.

Stentless bioprostheses show excellent early hemodynamic performance. However, longevity still remains unknown. This study reports midterm follow-up in 419 patients in which a Freestyle bioprosthesis (Medtronic Heart Valves, Minneapolis, MN) was inserted between January 1993 and January 2000 at the Quebec Heart Institute (Ste-Foy, Québec, Canada). Mean age at implantation was 68.0 +/- 8.2 years. Implantation was subcoronary in 81.9% of the patients, as a root replacement in 16.5%, and as a root inclusion in 1.7%. Mortality at 30 days was 6.2% for the whole cohort (2.8% for isolated subcoronary aortic valve replacement). Female gender, root implantation, valve sizes 19 to 21 mm, previous surgery, a history of stroke and diabetes were identified as predictors of 30-day mortality. Actuarial freedom from all death causes was 81.5% at 7 years; freedom from valve-related deaths 97.0%, and freedom from cardiac deaths 92.7%. Freedom from thromboembolic events was 86.1% at 7 years (55.1% of events were < 30 days). Freedom from endocarditis and hemorrhagic complications were respectively 98.5% and 95.6% at 7 years. Six patients required reoperations for valve explantation: 2 for endocarditis, 2 for structural dysfunction, and 2 for nonstructural dysfunction. Incidence of moderate or severe valve insufficiency at annual echocardiographic follow-up was: discharge: 0.6%; year 1: 0.7%; year 2: 1.3%; year 3: 3.3%; year 4: 3.7%; year 5: 2.6%; year 6: 0%. At 6 years after implantation, mean transvalvular gradient and effective valve orifice area were comparable to the year 1 values. This single center experience with the Medtronic Freestyle prosthesis shows preserved hemodynamic performance and low valve-related complications at midterm.

Actuarial Analysis↗
PubMed2000

6-Aminonicotinamide inhibition of the pentose phosphate pathway in rat neocortex.

6-Aminonicotinamide (6-AN) is thought to inhibit the pentose phosphate pathway (PPP) since large increases in 6-phosphogluconate are observed following its administration. Immediately following 45 min i.v. infusion of [2-(13)C]glucose to controls and 6-AN-treated (50 mg/kg i.p. given 4 h previously) Sprague-Dawley rats (n = 5 for both groups), metabolism was arrested using freeze-funnel fixation. Chloroform-methanol-water neocortical extracts from animals administered with 6-AN demonstrated elevated levels of 6-phosphogluconate and 6-phosphoglucono-delta-lactone, both of which demonstrated labeling through metabolism of [2-(13)C]glucose. Comparison of the C-2 and C-3 lactate positions using 1H NMR spectroscopy showed that the fraction of glucose metabolized through the PPP is unchanged by 6-AN (14+/-0.6% vs 14+/-0.3% in control animals). It is hypothesized that as the PPP is inhibited by metabolites of 6-AN in the neocortex, glycolysis is inhibited in a proportionate manner through an inhibitory effect on phosphoglucose isomerase by 6-phosphogluconate and/or 6-phosphoglucono-delta-lactone.

6-Aminonicotinamide↗
PubMed1999

Valved homograft conduit repair of the right heart in early infancy.

BACKGROUND: Valved homograft conduit repair in neonates and young infants creates a physiologically normal biventricular circulation, and unlike shunts, avoids surgery on the branch pulmonary. METHODS: Retrospective chart review was used for 84 patients operated on between 1990 and 1995 (mean age 26+/-28 days, mean weight 3.3+/-0.8 kg) undergoing homograft conduit repair in the first 3 months of life. Cases were divided into simple and complex, eg, absent pulmonary valve syndrome or associated interrupted arch. Mean homograft size was 9.0+/-2 mm. RESULTS: Early mortality was 4.7% (simple) and 30% (complex). Mean hospital stay was 18 days. Mean follow-up was 34 months. Thirty-seven (47%) patients underwent conduit replacement. Median time to reoperation was 3.1 years. Mean size of replacement homograft was 17+/-2 mm. There were no deaths at reoperation. Mean hospital stay at conduit change was 6.3 days. Probability of survival at 5 years is 75%. CONCLUSIONS: Biventricular repair employing a conduit can be performed safely in noncomplex anomalies in the first 3 months of life. Time interval until repeat surgery is relatively short but equal or greater than that with most palliative procedures.

Bioprosthesis↗
PubMed1998

Factors leading to a strike vote and strategies for reestablishing relationships.

An extremely difficult contract negotiation between a collective bargaining unit and a hospital resulted in a vote to strike by the nursing staff before reaching a final agreement. The authors describe the factors that led up to the strike vote. Realistic yet optimistic strategies for developing a working relationship with the bargaining unit leadership and the nursing staff are described.

Boston↗
PubMed1997

Simultaneous single-lung transplantation and lung volume reduction.

We report our experience with 2 cases of simultaneous single-lung transplantation and lung volume reduction for emphysema. The lung volume reduction was undertaken electively in an attempt to improve overall lung function above that to be expected from single-lung transplantation alone. There were no postoperative problems related to the addition of lung volume reduction. The pulmonary function at 3 months was greater than that seen in a retrospective group of bilateral lung transplants previously reported from our institution.

Female↗
PubMed1995

Experience with repair of congenital heart defects using adjunctive endovascular devices.

The use of endovascular devices as an adjunct to repair of congenital heart anomalies represents a novel but unproven therapeutic approach. Intraoperative implantation of pulmonary arterial stents (5 to 15 mm diameter) was done in 11 patients with pulmonary atresia with ventricular septal defect (n = 4), classic tetralogy of Fallot (n = 2), truncus arteriosus (n = 1), hypoplastic left heart syndrome (stage II [n = 1] and stage III [n = 1] Norwood procedure), and miscellaneous pulmonary arterial stenoses (n = 3), as well as in patients with congenital (n = 1) and postoperative (n = 3) pulmonary venous obstruction and in 1 patient with combined pulmonary arterial and venous obstruction. The stents were effective at achieving immediate patency in all patients. There were two early deaths, one related to acute thrombosis of a small-diameter left pulmonary artery stent. Reintervention because of stent-related pulmonary arterial stenosis was frequently necessary. In five of seven patients who survived more than 1 month after implantation of stent size 8 mm or smaller severe stent-related pulmonary arterial obstruction developed. In four of the five patients with pulmonary vein stent implantation intractable obstruction developed, resulting in death in all three patients who had bilateral pulmonary vein stent implantation. Intraoperative occlusion of apical muscular ventricular septal defect with use of a clamshell device inserted from the right atrial approach was accomplished in four patients. One patient who underwent associated aortic arch reconstruction died as a result of left ventricular hypoplasia. The results in the remaining three patients were favorable on the basis of absence of significant late residual intraventricular shunting, left ventricular dysfunction, or arrhythmia. We conclude that recurrent intraluminal obstruction as a result of neointimal hyperplasia appears to be an eventual certainty in currently designed small-diameter endovascular stents. For this reason, we would recommend standard surgical techniques for repair of obstructive lesions of the pulmonary arterial confluence to maximize growth potential. Device occlusion of muscular ventricular septal defects is feasible but probably only indicated for complex cases of ventricular septal deficiency that otherwise necessitate a left ventriculotomy.

Adolescent↗
PubMed1993

Conservative management of adnexal torsion.

OBJECTIVES: Our purpose was to evaluate morbidity in patients who underwent conservative therapy, ovarian cystectomy, for adnexal torsion compared with those who underwent salpingo-oophorectomy and to determine predictive factors associated with the ability to perform conservative surgery. STUDY DESIGN: A retrospective review of all women < 40 years old with adnexal torsion treated between May 1, 1989, and Dec. 31, 1991, was performed. All potentially viable adnexa were untwisted, and cystectomies were performed unless the adnexa failed to reperfuse. RESULTS: Ninety-four women were studied, and of these 61 (65%) received ovarian cystectomies and 33 (35%) underwent salpingo-oophorectomy. No thromboembolic complications or increase in postoperative morbidity was seen. Patients requiring salpingo-oophorectomy had more preoperative fevers and leukocytosis, larger masses, and higher degrees of torsion. CONCLUSION: Conservative surgery with untwisting of the adnexa followed by cystectomy can be performed in reproductive-age women with adnexal torsion who have potentially viable adnexa.

Adnexal Diseases↗