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J Angel

Publications and source records attributed to J Angel.

At least 19 recordsLinked to original sources
PubMed2003

Intravascular ultrasound of the elastic pulmonary arteries: a new approach for the evaluation of primary pulmonary hypertension.

OBJECTIVE: To assess the structural and functional characteristics of pulmonary arteries by intravascular ultrasound (IVUS) in the setting of primary pulmonary hypertension, and to correlate the ultrasound findings with haemodynamic variables and mortality at follow up. DESIGN: Prospective observational study. SETTING: University hospital (tertiary referral centre). PATIENTS: 20 consecutive patients with primary pulmonary hypertension (16 female; mean (SD) age, 39 (14) years). METHODS: Cardiac catheterisation and simultaneous IVUS of pulmonary artery branches at baseline and after infusion of epoprostenol. RESULTS: 33 pulmonary arteries with a mean diameter of 3.91 (0.80) mm were imaged, and wall thickening was observed in all cases, 64% being eccentric. Mean wall thickness was 0.37 (0.13) mm, percentage wall area 31.0 (9.3)%, pulsatility 14.6 (4.8)%, and pulmonary/elastic strain index 449 (174) mm Hg. No correlation was observed between IVUS findings and haemodynamic variables. Epoprostenol infusion increased pulsatility by 53% and decreased the pulmonary/elastic strain index by 41% (p = 0.0001), irrespective of haemodynamic changes. At 18 (12) months follow up, nine patients had died. A reduced pulsatility and an increased pulmonary/elastic strain index were associated with increased mortality at follow up (12.0 (4.4)% v 16.4 (4.4)%, p = 0.03; 369 (67) v 546 (216) mm Hg, p = 0.02). CONCLUSIONS: IVUS demonstrated pulmonary artery wall abnormalities in all patients with primary pulmonary hypertension, mostly eccentric. The severity of the changes did not correlate with haemodynamic variables, and epoprostenol improved pulmonary vessel stiffness. There was an association between impaired pulmonary artery functional state as determined by IVUS and mortality at follow up.

Adolescent↗
PubMed2002

Spectral characteristics of B-waves and other low-frequency activity.

Low frequency oscillations of intracranial pressure (ICP) between 0.5 to 2.0 cycles/min have been termed B-waves. While such low frequency activity may be generated by cerebral vasomotor activity, activity in the B-wave band may also be related to other causes. The objective of this study is to: 1) describe the low frequency characteristics of ICP and arterial blood pressure (ABP) recordings with a mathematical model based on ventilator-induced intrathoracic pressure (ITP) modulation of arterial blood pressure; and 2) use the model to eliminate low frequency activity within the B-wave range unrelated to vasomotor activity. The model describes the frequency locations of spectra associated with ventilation about both the principal and first harmonic cardiac frequency to within 1% error. Spectra within the B-wave range harmonically related to the ventilator frequency were classified as caused by patient-ventilator interaction. Of 11 patients with severe head-injury, 64% (7/11) demonstrated B-wave activity, and 4 patients demonstrated the activity solely in the ICP recording. Variation of heart rate did not correspond to the occurrence of B-waves. The proposed model describes the low frequency spectra found within ABP and ICP recordings and can be used to eliminate spectra with the B-wave range related to ventilation.

Adolescent↗
PubMed2001

Frequency and clinical significance of myocardial ischemia detected early after coronary stent implantation.

UNLABELLED: A high number (30%-50%) of reversible defects have been detected early after coronary balloon angioplasty. Inadequate luminal enlargement despite a good angiographic appearance has been suggested as a possible mechanism of these perfusion abnormalities, and some reports have shown better coronary flow reserve after coronary stent implantation than after balloon dilatation. The primary objective of this study was to evaluate the frequency of early ischemic defects detected by maximal exercise (plus dipyridamole) with (99m)Tc-tetrofosmin SPECT after successful coronary angioplasty with stent implantation. A secondary objective was to determine the prognostic value of these early ischemic defects. METHODS: Thirty patients without previous myocardial infarction who successfully underwent 1-vessel coronary angioplasty with stent implantation were studied. Maximal-exercise (99m)Tc-tetrofosmin myocardial SPECT, with simultaneous dipyridamole if exercise was suboptimal, was performed at 6 +/- 1 d (mean +/- SD) after percutaneous transluminal coronary angioplasty. At 8 +/- 3 mo, all patients were followed up clinically, and 77% of them underwent follow-up angiography. RESULTS: The percentage of stenosis decreased from 68.5% +/- 12.6% of luminal diameter to 9.3% +/- 8.8% after stent implantation, and minimal luminal diameter increased from 0.89 +/- 0.36 mm to 2.85 +/- 0.45 mm. Mild-to-moderate reversible myocardial defects in the territory of the dilated artery were detected in 5 patients (17%), with no angiographic or procedural differences occurring between them and patients without ischemic defects. At follow-up, the target lesion revascularization rates depending on the presence or absence of early ischemic defects were 40% and 8%, respectively (P = 0.18). Angiographic restenosis occurred in 3 of 4 patients who had early ischemic defects and underwent follow-up angiography and in 3 of 19 patients who had no early ischemic defects and underwent follow-up angiography (restenosis rate, 75% and 16%, respectively; P < 0.05). CONCLUSION: Coronary angioplasty with stent implantation is associated with a 17% rate of ischemic defects early after the procedure. Patients with early myocardial perfusion defects after coronary stent implantation had a high rate of restenosis.

Angioplasty, Balloon, Coronary↗
PubMed2000

Strategy for optimal aortic regurgitation quantification by Doppler echocardiography: agreement among different methods.

BACKGROUND: Although different Doppler methods have been validated for aortic regurgitation quantification, the benefit of combining information from different methods has not been defined. METHODS: Our study included 2 phases. In the initial phase (60 patients), Doppler parameters (jet width, short-axis jet area, apical jet area, regurgitant fraction from pulmonary and mitral flow, and deceleration slope) were correlated with angiography; range values for each severity grade were defined and intraobserver and interobserver and intermachine variability were studied. In the validation phase (158 patients), defined value ranges were prospectively tested and a strategy based on considering as the definitive severity grade that in which the two best methods agreed was tested. RESULTS: Jet width had the best correlation with angiography (r = 0.91), and its ratio with the left ventricular outflow diameter did not improve the correlation (r = 0.85) and decreased reproducibility. Apical jet area and regurgitant fraction from pulmonary flow permitted acceptable quantification (r = 0.87 and 0.86, respectively) but with worse reproducibility. The other methods were not assessable in 20% to 30% of studies. Concordance with angiography decreased in jet width when the jet was eccentric (90% vs 77%, P <.01), in apical jet area when mitral valve disease was present (84% vs 65%, P <.02), and in short-axis jet area and regurgitant fraction from pulmonary flow with concomitant aortic stenosis (77% vs 44%, P <.002 and 77% vs 53%, P <.02, respectively). Agreement with angiography was very high (94 [95%] of 99) when severity grade coincided in both jet width and apical jet area. In 59 cases without concordance, regurgitant fraction from pulmonary flow was used as a third method. Overall, this strategy permitted concordance with angiography in 146 patients (92%). CONCLUSIONS: Jet width is the best predictor in aortic regurgitation quantification by Doppler echocardiography. However, better results were obtained when a strategy based on concordance between jet width and another Doppler method was established, particularly when the jet was eccentric.

Adult↗
PubMed1999

Long-term follow-up of idiopathic chronic pericardial effusion.

BACKGROUND: A large idiopathic chronic pericardial effusion can be defined as a collection of pericardial fluid that persists for more than three months and has no apparent cause. We conducted a prospective study of the natural history and treatment of this disorder. METHODS: Between 1977 and 1992, we prospectively evaluated and enrolled patients with large idiopathic chronic pericardial effusion. We performed pericardiocentesis in most of the patients. We performed pericardiectomy when large pericardial effusion reappeared after pericardiocentesis. Follow-up ranged from 18 months to 20 years (median, 7 years). RESULTS: During the study period, we evaluated a total of 1108 patients with pericarditis, 461 of whom had large pericardial effusion. Twenty-eight of these patients (age range, 7 to 85 years; median, 61) had large idiopathic chronic effusion and were included in the study. The duration of effusion ranged from 6 months to 15 years (median, 3 years). At the initial evaluation, 13 patients were asymptomatic. Overt tamponade was found in eight patients (29 percent). Therapeutic pericardiocentesis, performed in 24 patients, was followed by the disappearance of or marked reduction in the effusion in 8. Five of the 24 patients underwent early pericardiectomy, and in 11 large pericardial effusion reappeared. Cardiac catheterization, performed in 16 patients, showed elevated intrapericardial pressure (4.75+/-3.79 mm Hg) and reduced transmural pressure (1.0+/-2.50 mm Hg) before pericardiocentesis. Both of these abnormalities in pressure improved significantly after pericardiocentesis. Pericardiectomy, performed in 20 patients, yielded excellent long-term results. At the end of the follow-up period, 10 patients had died, but none had died from pericardial disease. CONCLUSIONS: Large idiopathic chronic pericardial effusion is well tolerated for long periods in most patients, but severe tamponade can develop unexpectedly at any time. Pericardiocentesis alone frequently results in the resolution of large effusions, but recurrence is common and pericardiectomy should be considered whenever a large effusion recurs after pericardiocentesis.

Adolescent↗
PubMed1999

The epithelial cell response to rotavirus infection.

Rotavirus is the most important worldwide cause of severe gastroenteritis in infants and young children. Intestinal epithelial cells are the principal targets of rotavirus infection, but the response of enterocytes to rotavirus infection is largely unknown. We determined that rotavirus infection of HT-29 intestinal epithelial cells results in prompt activation of NF-kappaB (<2 h), STAT1, and ISG F3 (3 h). Genetically inactivated rotavirus and virus-like particles assembled from baculovirus-expressed viral proteins also activated NF-kappaB. Rotavirus infection of HT-29 cells induced mRNA for several C-C and C-X-C chemokines as well as IFNs and GM-CSF. Mice infected with simian rotavirus or murine rotavirus responded similarly with the enhanced expression of a profile of C-C and C-X-C chemokines. The rotavirus-stimulated increase in chemokine mRNA was undiminished in mice lacking mast cells or lymphocytes. Rotavirus induced chemokines only in mice <15 days of age despite documented infection in older mice. Macrophage inflammatory protein-1beta and IFN-stimulated protein 10 mRNA responses occurred, but were reduced in p50-/- mice. Macrophage inflammatory protein-1beta expression during rotavirus infection localized to the intestinal epithelial cell in murine intestine. These results show that the intestinal epithelial cell is an active component of the host response to rotavirus infection.

Aging↗
PubMed1999

Effectiveness of an educational strategy to improve family physicians' detection and management of depression: a randomized controlled trial.

BACKGROUND: Depression, a common disorder often treated by family physicians, may be both underdiagnosed and undertreated. The objective of this study was to determine whether the diagnosis and treatment of depression by family physicians could be improved through an educational strategy. METHODS: In this study, conducted between July and December 1997, 42 family physicians in Newfoundland were randomly assigned to an intervention group (3-hour case-based educational session on clinical practice guidelines [CPGs] for depression and access to a psychiatrist for consultation) or to a control group (receipt of CPGs without educational session or access to the psychiatrist). Physicians were asked to keep a log of patients with newly diagnosed depression and to record information on severity of depression, medications and referrals to mental health professionals. Patients were asked to complete the Centre for Epidemiologic Studies Depression (CES-D) scale before treatment and after 6 months of follow-up. The primary outcome measure was the "gain" score (difference between first and last CES-D scores). RESULTS: During the study period physicians in the intervention group diagnosed 91 new cases of depression (mean 4.1 per physician) and those in the control group diagnosed 56 (mean 2.8 per physician); the difference was not significant. Most patients (91.2% in the intervention group and 89.3% in the control group received a prescription for an antidepressant on their first visit. Similar proportions (46.2% in the intervention group and 37.5% in the control group) took their medication for the full 6 months; however, significantly more patients in the intervention group were taking an antidepressant at the 6-month follow-up (56% v. 39.3%, p = 0.02). The mean number of visits per patient was similar in the 2 groups (7.7 in the intervention group and 7.6 in the control group). Physicians in the intervention group consulted the psychiatrist 9 times. The overall rate of referrals to psychiatrists and other mental health professionals was 10.9%; however, referrals were significantly higher in the intervention group (15.4% v. 3.5%, p = 0.05). After 6 months of follow-up, a significant difference in gain scores was detected between the intervention and control groups for both the patient's self-rated CES-D scores (mean gain score 19.3 v. 15.5 respectively, p = 0.04) and the physicians' ratings of depression severity before treatment and at 6 months (mean gain 1.1 v. 0.7 respectively, p = 0.02). INTERPRETATION: The educational strategy had a modest beneficial effect on the outcomes of patients with depression, but there are still concerns regarding the low rates of drug treatment and referral to mental health professionals by family physicians.

Adult↗
PubMed1999

Lack of a role for type I and type II interferons in the resolution of rotavirus-induced diarrhea and infection in mice.

Rotavirus infects the intestinal epithelium of most mammalian species and causes diarrhea in infants. Previously, we have shown that both type I and II human interferons (IFNs) have potent and mechanistically discreet antiviral effects in vitro against rotavirus. We have also shown that adult IFN-gamma knockout (-/-) mice have no alteration in clearance of primary rotavirus infection. In the present studies, we wished to determine the importance of both IFN types in modulation of degree and duration of disease and infection in mice. Immunocompetent suckling mice were treated orally (5,000 IU) or parenterally (500 IU) with type I and II murine IFNs before and after challenge with virulent murine rotavirus. Treated animals developed diarrhea indistinguishable from that observed in untreated control mice. In other experiments, type I IFN receptor -/- suckling mice and IFN-gamma-/- suckling mice developed diarrhea of similar characteristics and duration and had comparable quantities of viral antigen in their intestines as did immunocompetent mice. Furthermore, type I IFN receptor -/- adult mice infected with rotavirus shed equivalent quantities of viral antigen and with similar kinetics as the control mice. Thus, IFNs do not seem to be major inhibitors of rotavirus diarrhea or replication in mice.

Animals↗
PubMed1998

[Diagnostic efficacy of myocardial tomographic imaging in the detection of restenosis after coronary angioplasty].

INTRODUCTION AND OBJECTIVES: To analyze the efficacy of single photon emission tomography (SPET) with 99mTc-compounds for the diagnosis of restenosis of previous percutaneous transluminal coronary angioplasty (PTCA). PATIENTS AND METHODS: Seventy-one patients (16 women, median age: 60 years, 35 with multivessel disease, 78 arteries with PTCA) with previous PTCA and with coronary angiography performed after scintigraphy were studied. 99mTc-SPET exercise (53 with MIBI and 18 with tetrofosmin) was performed, for clinical reasons, to all patients between one month and 4 years after PTCA. Intravenous dipyridamole was administered simultaneously to 16 patients who had insufficient exercise. RESULTS: SPET sensitivity, specificity, positive predictive values, negative predictive values and global values were all significantly higher than those obtained with exercise tests (80% vs 63%; p = 0.05; 83% vs 37%; p = 0.001; 91% vs 69%; p = 0.007; 64% vs 31%; p = 0.009, and 81% vs 55%; p = 0.0006, respectively). These results were significantly superior in patients with one vessel disease than in patients with multivessel disease. CONCLUSIONS: SPET exercise with 99mTc-compounds is a test with a high efficacy for the diagnosis of post-PTCA restenosis, mainly in patients with one vessel disease.

Aged↗
PubMed1998

Studies of the role for NSP4 in the pathogenesis of homologous murine rotavirus diarrhea.

A rotavirus (RV) nonstructural protein, NSP4, has recently been proposed to function as an enterotoxin in the pathogenesis of RV diarrhea. The role of NSP4 in the pathogenesis of RV diarrhea was examined by infecting cystic fibrosis transmembrane conductance regulator (CFTR) knockout mice with virulent murine RV and by comparing deduced amino acid sequences of RV gene 10 encoding NSP4 from three distinct sets of virulent and tissue culture-adapted avirulent variant RVs. Homozygous CFTR (CFTR-/-) mice, which do not respond to any known intestinal secretagogues, experienced diarrhea comparable to that in normal CFTR+/+ littermates after RV challenge. Comparison of amino acid sequences of NSP4 from virulent and attenuated pairs of RVs failed to show consistent or significant changes. Together, these data suggest that enterotoxigenic properties of RV NSP4 are not critical in the pathogenesis of murine RV diarrhea and that attenuation of murine RVs is not usually mediated by mutations in the gene encoding NSP4.

Animals↗
PubMed1998

Identification of mutations in the rotavirus protein VP4 that alter sialic-acid-dependent infection.

To explore further the role of VP4 as the rotavirus cell attachment protein, VP7 monoreassortants derived from the sialic-acid-dependent simian strain RRV and from the sialic-acid-independent human strains D, DS-1 and ST-3 were tested for susceptibility of infectivity of neuraminidase-treated MA-104 cells. Infectivity of RRV x D VP7 and RRV x ST-3 VP7 monoreassortants decreased when sialic acid was removed from the cell surface. However, of three separate RRV x DS-1 VP7 monoreassortants tested, only one was sialic-acid-dependent. Sequence analysis showed that both sialic-acid-independent strains contained a single amino acid change, Lys to Arg, at position 187. In addition, sialic-acid-independent infectivity was seen in one of 14 RRV VP4 neutralization escape mutants tested, and this strain was found to have a Gly to Glu change at amino acid position 150. These results indicate that positions 150 and 187 of VP4 play an important role in early rotavirus-cell interactions.

Animals↗
PubMed1998

[Quantification of left-to-right shunt in atrial septal defect using oximetry, isotopes, and Doppler echocardiography. Is there a method of reference?].

INTRODUCTION: Determination of pulmonary to systemic blood flow ratio (QP/QS) is considered to be important for the management of patients with atrial septal defect. The QP/QS provides information on shunt severity and is usually determined by three methods: oximetry, first-pass radionuclide angiocardiography and Doppler echocardiography. The aim of the present study was to assess the accuracy and concordance level of these three methods in QP/QS quantification in atrial septal defects. PATIENTS AND METHODS: Sixty-four adult atrial septal defects patients in whom QP/QS was determined by these three methods with a 6 month interval were studied. Nuclear and echocardiographic post-surgical studies were repeated in 36 patients. RESULTS: QP/QS values determined by the three techniques had a low correlation between them: oximetry (r = 0.52; SEE = 0.74); radionuclide angiocardiography (r = 0.40; SEE = 0.79) and Doppler echocardiography (r = 0.72; SEE = 0.57). Radionuclide angiocardiography underestimated QP/QS > 3 (-0.61 +/- 1.21; p < 0.01). Only in 33% of studies there concordance (differences < 0.5) among the three methods and in 58% between two methods. Right ventricular dilatation and tricuspid regurgitation influenced radionuclide accuracy. Nevertheless, the correlation between this technique and echocardiography was satisfactory when the 36 post-surgical were included (r = 0.75); both techniques agreed in the diagnosis of the two cases with residual post-surgical shunt. CONCLUSIONS: Inter-method disparity in QP/QS quantification is high and no method can be used as a gold standard; clinical decisions therefore based on QP/QS quantification by one technique alone are ill-advised.

Adult↗