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Biomedical subjects

C Boutin

Publications and source records attributed to C Boutin.

At least 73 records · Page 4Linked to original sources
PubMed1997

Fetal echocardiographic screening of diabetic pregnancies for congenital heart disease.

This study sought to assess pregnant diabetic women for the presence of fetal cardiac anomalies and to determine whether better diabetic control was associated with a reduced risk to the fetus. Between 1988 and 1995, pregnant type I and II diabetic women routinely underwent fetal echocardiography. Hemoglobin A1c values were used as an indicator of maternal diabetic control and any relation between congenital heart disease in the fetus and maternal hemoglobin A1c levels was sought. Cardiac defects were identified in 7 of 328 pregnancies assessed, for an incidence of congenital heart disease of 2.1% (95% confidence interval: 0.6-3.6%). A review of the postnatal cardiac database did not reveal any undetected major malformations. The mean hemoglobin A1c level was 7.6% +/- 2.0% obtained at a mean gestational age of 12 +/- 7 weeks. Hemoglobin A1c levels of mothers carrying a fetus with congenital heart disease did not significantly differ from those with a normal fetus: 8.1% +/- 3.4% versus 7.6% +/- 1.9% (p = 0.48). Mothers with an affected fetus demonstrated a wide range of HbA1c levels (4.1 to 13.7%). Thus, the incidence of significant fetal cardiac abnormalities is low and not significantly related to maternal diabetic control.

Adult↗
PubMed1997

Evolution of fetal ventricular aneurysms and diverticula of the heart: an echocardiographic study.

Due to the rarity of congenital ventricular diverticula and aneurysms, their natural history remains unclear. An excellent prognosis has been suggested for those cases diagnosed during fetal life: From October 1992 to January 1996 seven fetuses were diagnosed with ventricular diverticula or aneurysms. Gestational age ranged from 18 to 36 weeks. The indications for fetal echocardiogram were cardiomegaly, abnormal four-chamber view, a large pericardial effusion, and hydrothorax. Echocardiography revealed a moderate sized apical left ventricular aneurysm (2), a small subvalvular right ventricular diverticulum (1), small apical right ventricular diverticulum (2), a large submitral left ventricular aneurysm (1), and a large diverticulum arising from the lateral free wall of the left ventricle (1). Decreased left ventricular function was detected in three fetuses with left ventricular aneurysms. Two fetuses with large lesions, developed hydrops and died in utero. Postnatal echocardiograms confirmed prenatal findings in all survivors. All infants remained asymptomatic, with age on follow-up from 8 to 24 months. An accurate diagnosis of ventricular diverticula and aneurysms is feasible prenatally. Outcome depends on the size and progression of the lesion. The presence of a large pericardial effusion in three cases with a diverticula was noted.

Diagnosis, Differential↗
PubMed1997

Differential responsiveness of human and rat mesothelioma cell lines to recombinant interferon-gamma.

Recombinant human interferon-gamma (r-hu-IFN-gamma) has been found to exert an antitumor action in vivo in early stages of human malignant mesothelioma, and an antiproliferative effect in vitro. In order to study the mechanisms of cytostasis in mesothelioma cells, we examined two IFN-gamma-controlled metabolic pathways known to mediate growth arrest in various cell types, measuring production of the antiproliferative compound nitric oxide (NO) and degradation of tryptophan in nine human mesothelioma cell lines (HMCLs) displaying different sensitivities to the antiproliferative effect of r-hu-IFN-gamma. Two rat mesothelioma cell lines were also studied. IFN-gamma receptor was present and functional in HMCLs, regardless of their sensitivity to the growth-inhibitory effect of r-hu-IFN-gamma. However, no NO synthase activity or the resulting antiproliferative molecule NO were induced in HMCLs treated either with r-hu-IFN-gamma alone or with a combination of r-hu-IFN-gamma and other cytokines, and/or with lipopolysaccharide (LPS). In responsive HMCLs, r-hu-IFN-gamma induced strong indoleamine-2,3-dioxygenase (IDO) activity, which causes rapid degradation of tryptophan; however, the correlation between r-hu-IFN-gamma-mediated growth arrest and IDO induction was not absolute. In rat mesothelioma cells, NO synthase was induced in response to murine IFN-gamma + interleukin-1beta (IL-1beta) treatment, and played a role in the cytokine-mediated antiproliferative activity. However, NO production did not seem to be the unique antiproliferative mechanism induced by cytokines in these cells. Our results indicate that two classical pathways accounting for some of the cytostatic effects of IFN-gamma in rodent cells are not efficient in human mesothelioma cells, and suggest that cytokine-induced growth inhibition is mediated by a different pathway in HMCLs.

Animals↗
PubMed1997

The use of confocal microscopy in the investigation of cell structure and function in the heart, vascular endothelium and smooth muscle cells.

In recent years, fluorescence microscopy imaging has become an important tool for studying cell structure and function. This non invasive technique permits characterization, localisation and qualitative quantification of free ions, messengers, pH, voltage and a pleiad of other molecules constituting living cells. In this paper, we present results using various commercially available fluorescent probes as well as some developed in our laboratory and discuss the advantages and limitations of these probes in confocal microscopy studies of the cardiovascular system.

Animals↗
PubMed1997

Researching nurses as educators.

This study uses a survey to investigate the nurse educator's perceptions of their work and goals. Respondents were educators selected from a national list of nurses with doctorates. The survey used a combination of objective and open-ended questions. The purpose was to seek a correlation between the interests of the faculty and the expectations of their hiring institutions. Suggestions are made on ways educators, clinicians, and administrators can collaborate and consult for their mutual benefit.

Efficiency↗
PubMed1997

[An experimental model of pleural cancer. Value of orthotopic implantation of human tumor tissue in nude mice].

Pleural cancers are tumours which are frequently refractory to all treatment. Faithful animal models (experimentally reproducing the human disease) are necessary to study the natural history of this disease and to test standard or experimental treatments. The athymic bald mouse is currently used for the construction of experimental models because it avoids immunological rejection. Initially murine models were constructed following subcutaneous injection of cloned cells then implantation of tumour fragments. The tumours obtained are not superimposable on the human disease in terms of local, regional or metastatic development and the results from these studies, using such models, are difficult to transpose to humans. It is possible to implant fragments of histologically intact human tumour into the pleura of bald mice. This orthoptic (site for site) transplantation enables one to obtain in the mouse a tumour which tends to conserve the biological characteristics of the original tumour and to develop locally, regionally and at distance in a fashion which is similar to the human disease. In spite of the inherent limits of immunotolerance of the host and thus difficulties of extrapolation to man, this review attempts to point out the place for these models and for an understanding of the therapy of pleural cancers.

Adenocarcinoma↗
PubMed1996

Morphologic and hemodynamic consequences after percutaneous balloon valvotomy for neonatal pulmonary stenosis: medium-term follow-up.

OBJECTIVES: This study sought to evaluate ventricular and valvular morphologic changes, hemodynamic consequences and clinical outcomes of pulmonary balloon valvotomy performed in the neonatal period. BACKGROUND: Previous studies support percutaneous balloon valvotomy as the management option of choice for infants and children with valvular pulmonary stenosis. Less information is available to define the impact of valvotomy on the clinical course when performed in the neonatal period. METHODS: Patient records, catheterization data, cineangiograms and selected echocardiograms (initial and most recent studies) of 37 consecutive neonates undergoing attempted balloon dilation were reviewed. RESULTS: Dilation was accomplished in 35 (94%) of 37 attempts. Immediately after dilation, the transvalvular peak to peak systolic gradient decreased from 60 +/- 22 mm Hg (mean +/- SD, range 20 to 100) to 11 +/- 10 mm Hg (range 0 to 45) (p < 0.0001), and the right ventricular/aortic systolic pressure ratio decreased from 1.25 +/- 0.43 (range 0.5 to 2.6) to 0.66 +/- 0.22 (range 0.2 to 1) (p < 0.0001). Oxygen saturation measured by percutaneous oximetry increased from 80 +/- 7% to 92 +/- 4% (p < 0.0001). Three patients died (8%), and two required repeat balloon dilation. At the follow-up visit (median 31 months, range 6 months to 8 years), the estimated peak instantaneous Doppler gradient was 15 +/- 9 mm Hg (range 6 to 36). Thickening of valve leaflets, initially present in 93% of patients, was found in only 4%, and leaflet mobility improved in all. Hypoplasia of the right ventricle, initially present in 31%, was found in only 4% at the latest evaluation. Pulmonary annulus diameter Z score increased from -3 +/- 1.0 to 0 +/- 0.1 (p < 0.0001). Freedom from reintervention was 90%, 84% and 84% at 1, 2 and 8 years, respectively. CONCLUSIONS: These data support the application of balloon valvotomy as the initial intervention in the treatment algorithm for neonates with critical pulmonary valve stenosis. Medium-term follow-up observations demonstrate sustained hemodynamic relief and support maturation of the right ventricle and pulmonary valve annulus, with the expectation of a good long-term outcome.

Algorithms↗
PubMed1996

Short-term effect of monocuspid valves on pulmonary insufficiency and clinical outcome after surgical repair of tetralogy of Fallot.

In the surgical repair of tetralogy of Fallot, monocuspid valves are sometimes inserted within a transannular patch to prevent pulmonary insufficiency. To determine whether this monocuspid valve prevents short-term postoperative pulmonary insufficiency and improves clinical outcome, we reviewed clinical data and preoperative and postoperative echocardiographic variables from 61 patients who underwent one of three different procedures for repair of tetralogy of Fallot between August 1992 and March 1994. We compared features from 24 patients who had undergone transannular patch repair with a monocuspid valve (patch-valve) with those from 17 patients who had undergone patch repair without a monocuspid valve (patch) and 20 patients who had undergone repair without a transannular patch (no patch). We used the ratio of pulmonary valve insufficiency jet width to pulmonary artery diameter, as measured by color-flow Doppler flowmetry, as an index of severity of pulmonary insufficiency. Moderate to severe pulmonary insufficiency was arbitrarily defined as a ratio of at least 0.50. We found no significant differences in ratios among the patch-valve group (0.73 +/- 0.25, mean +/- standard deviation), the patch group (0.79 +/- 0.20), and the no patch group (0.59 +/- 0.23). The percentages of patients with moderate to severe pulmonary insufficiency did not differ among the three groups (patch-valve 80%, patch 90%, no patch 64%). Clinical data (including mortality, number of reoperations, intensive care unit and hospital lengths of stay, and postoperative hemodynamics) were similar in the three groups. We conclude that insertion of a monocuspid valve in repair of tetralogy of Fallot does not prevent short-term postoperative pulmonary insufficiency and does not improve immediate postoperative outcome for these patients.

Echocardiography↗
PubMed1996

Black spots concentrate oncogenic asbestos fibers in the parietal pleura. Thoracoscopic and mineralogic study.

Epidemiologic and pathologic data demonstrate that malignant mesothelioma occurs preferentially after exposure to long amphibole asbestos fibers. However, mineralogic studies have rarely detected such fibers in the parietal pleura. We hypothesized that the distribution of asbestos fibers in the pleura was heterogeneous and that they might concentrate in certain areas, as does coal dust in patients showing anthracotic "black spots" of the parietal pleura during thoracoscopy. We collected thoracoscopic biopsy samples from these black spots and from normal areas of the parietal pleura and lung from 14 subjects (eight with and six without asbestos exposure). Asbestos content was determined by transmission electron microscopy. In exposed subjects, mean fiber concentrations were 12.4 +/- 9.8 x 10(6) fibers/g of dry tissue in lung, 4.1 +/- 1.9 in black spots, and 0.5 +/- 0.2 in normal pleura. In unexposed patients, concentrations were 0, 0.3 +/- 0.1, and 0, respectively. Amphiboles outnumbered chrysotile in all samples. A total of 22.5% of fibers were > or = 5 microns in length in black spots. A histologic similarity of these black spots with milky spots is suggested by conventional and electron microscopy. We conclude that the distribution of asbestos fibers is heterogeneous in the parietal pleura. Indeed, the fibers concentrate in black spots, where they can reach high concentrations. These findings could explain why the parietal pleura is the target organ for mesothelioma and plaques.

Adenocarcinoma↗
PubMed1996

Thoracoscopic talc poudrage pleurodesis for malignant effusions. A review of 360 cases.

OBJECTIVE: To assess the efficacy, permanence, and safety of thoracoscopic talc poudrage (TTP) for pleurodesis in malignant effusions. DESIGN: Retrospective. PARTICIPANTS: Patients with lifetime follow-up who received TTP in two related centers in Marseilles, France. RESULTS: Three hundred sixty patients were included in this study: 88 had mesothelioma and 272 had pleural metastases. The mean follow-up time was 12 months (2 to 120). Of the 327 patients whose response could be evaluated, 90.2% had a successful pleurodesis at 1 month, and 82.1% had a life-long pleural symphysis. Adverse effects included 1 death 3 days after the procedure in a patient with end-stage disease, fever (9.8%), empyema (2.5%), pulmonary infection (0.8%), and malignant invasion of the scar (1 patient). CONCLUSIONS: TTP is an effective and safe method of lifelong pleurodesis. It should be performed early on in the history of malignant effusions to avoid the risk of respiratory failure, this being directly linked to the general and respiratory status of the patients at the time of the procedure.

Female↗
PubMed1995

Human malignant mesothelial cells: variability of ultrastructural features in established and nude mice transplanted cell lines.

The aim of this study was to determine, by transmission electron microscopy, the differentiation features of 21 human malignant mesothelioma cell lines (HMCLs) established from 13 specimens of 12 confirmed human malignant mesotheliomas, and of tumours induced in nude mice injected with 16 HMCLs. Fifty per cent of HMCLs showed typical mesothelial differentiation (long and slender microvilli, desmosomes, perinuclear intermediate filaments); 29 per cent did not show differentiation; and the remainder were poorly differentiated. Three human tumour specimens gave several different HMCLs; the cell lines obtained from a given tumour exhibited variable mesothelial differentiation. Eleven HMCLs were compared with the native tumour. Four were similar to the tumour and seven were less well differentiated, in most cases in relation to their microvilli. With six HMCLs, tumours induced in nude mice were less well differentiated than the corresponding cell lines, whereas with four HMCLs, tumours were equally or better differentiated. However, in most nude mice tumours, typical mesothelial microvilli were present. These results show that cell lines established from malignant mesothelioma may exhibit dedifferentiated features. However, while the variability in ultrastructural differentiation may result from the culture microenvironment, it could also be related to the state of differentiation, of the native tumour sample and to tumour cell heterogeneity.

Animals↗
PubMed1995

Should the routine use of atropine before succinylcholine in children be reconsidered?

It is common practice to administer atropine before a first dose of succinylcholine in infants and children. However, the administration of succinylcholine without atropine has not been investigated in children. This study was designed to compare cardiovascular changes after the administration of either atropine with succinylcholine or succinylcholine alone. In 41 ASA I or II patients aged from 1 to 12 yr anaesthesia was induced with thiopentone 5 mg.kg-1. Patients were randomly allocated to receive either atropine 20 micrograms.kg-1 and succinylcholine 1.5 mg.kg-1 (n = 20) or succinylcholine 1.5 mg.kg-1 alone (n = 21). Heart rate and rhythm were recorded continuously from two minutes before induction until two minutes after tracheal intubation. Blood pressure was measured non-invasively before and after induction of anaesthesia and both immediately and two minutes after laryngoscopy. One self-limiting episode of bradycardia was recorded during laryngoscopy in a child who received atropine. Heart rate increased in both groups compared with baseline values (108 +/- 25), with a greater increase in patients who had received atropine (150 +/- 13) than in those who had not (128 +/- 18) (P < 0.05). There was no difference in mean arterial pressure or incidence of arrythmias between the two groups. No recorded arrythmias were judged to be clinically important by a cardiologist. The incidence of bradycardia after succinylcholine in the absence of atropine in children aged from 1 to 12 yr appears to be lower than previously estimated. The use of atropine before a single dose of succinylcholine in children deserves to be reconsidered.

Adjuvants, Anesthesia↗
PubMed1995

Subaortic stenosis in the spectrum of atrioventricular septal defects. Solutions may be complex and palliative.

UNLABELLED: From July 1982 through September 1994, 19 children had operative treatment of subaortic stenosis associated with an atrioventricular septal defect. Specific diagnosis were septum primum defects in 7, Rastelli type A defects in 6, transitional defects in 4, inlet ventricular septal defect with malattached chordae in 1, and tetralogy of Fallot with Rastelli type C defect in 1. Twenty-seven operations for subaortic stenosis were performed. Surgical treatment of the outlet lesion was performed at initial atrioventricular septal defect repair in 3 children and in the remaining 16 from 1.2 to 13.1 years (mean 4.9 years, median 3.9 years) after repair. Eighteen of the 19 children had fibrous resection and myectomy for relief of obstruction. Seven children had an associated left atrioventricular valve procedure. One child received an apicoaortic conduit. Seven children (36.8%) required 8 reoperations for previously treated subaortic stenosis. Time to the second procedure was 2.8 to 7.4 years (mean 4.9 years). Follow-up is 0.4 to 14.0 years (median 5.6 years). Six-year actuarial freedom from reoperation is 66% +/- 15%. The angle between the plane of the outlet septum and the plane of the septal crest was measured in 10 normal hearts (86.4 +/- 13.7) and 10 hearts with atrioventricular septal defects (22.2 +/- 26.0; p < 0.01). The outflow tract can be effectively shortened, widened, and the angle increased toward normal by augmenting the left side of the superior bridging leaflet and performing a fibromyectomy. CONCLUSION: Standard fibromyectomy for subaortic stenosis in children with atrioventricular septal defects leads to a high rate of reoperation. Leaflet augmentation and fibromyectomy may decrease the likelihood of reoperation.

Adolescent↗
PubMed1995

Status of the left ventricle after arterial switch operation for transposition of the great arteries. Hemodynamic and echocardiographic evaluation.

BACKGROUND: The potential for improved preservation of systemic ventricular function represents an important reason for the increasing popularity of the arterial switch operation. In support of this expectation, prior studies in patients early after arterial switch operation have found normal ventricular contractility and function. This study was conducted to extend those observations to up to 10 years of follow-up and to directly examine the effects of a coexisting ventricular septal defect or short-term preparatory banding of the pulmonary artery before the arterial switch operation. METHODS: Patients operated on from 1983 through 1991 were included. Echocardiographic and catheterization data were collected as part of a prospective evaluation of outcome in all patients who undergo the arterial switch operation at Boston Children's Hospital, with inclusion of data from the most recent catheterization only. Echocardiograms performed at least 6 months after the operation were included, with assessment of both the most recent status as well as serial trends. Whenever possible, echocardiographic evaluation included data necessary to perform analysis of ventricular mechanics including indices of afterload, preload, and contractility. Comparison was made to normal values and between subgroups defined on the basis of an arterial switch operation with or without ventricular septal defect and those who had a rapid two-stage arterial switch operation. RESULTS: Invasive measures of left and right ventricular filling pressures, cardiac index, and pulmonary vascular resistance did not differ among the three groups. Overall, echocardiographic left ventricular end-diastolic dimension, wall thickness, mass, afterload (end-systolic wall stress), function (fractional shortening and rate-corrected velocity of fiber shortening), contractility (stress-velocity and stress-shortening relations), and preload were normal, and none of these variables was different between the groups with and without a ventricular septal defect. Serial evaluation indicated a slight but significant trend toward ventricular dilatation, perhaps related to a relatively high incidence of at least mild aortic regurgitation (30%). In contrast, in the rapid two-stage group the echocardiographic indices of left ventricular function (fractional shortening and velocity of fiber shortening) and contractility (stress-velocity and stress-shortening relations) were found to be mildly but significantly reduced compared with normal subjects and with the other arterial switch operation groups. Over the duration of follow-up encompassed by this study, no tendency toward progressive depression of function was seen. CONCLUSIONS: As the length of observation after the arterial switch operation continues to increase, left ventricular size, mass, functional status, and contractility continues to be normal, with no evidence of time-related deterioration of function. As previously reported, the rapid two-stage arterial switch operation does represent a higher risk for mild impairment of myocardial mechanics.

Aortic Valve Insufficiency↗