Search PubMed⌕ Search

Biomedical subjects

D Metz

Publications and source records attributed to D Metz.

At least 55 records · Page 3Linked to original sources
PubMed1997

Characterisation of the normal conjunctival leukocyte population.

Lymphoid cells are present in normal mucosal tissue as scattered cells or organised into MALT. Knowledge of the non-pathological conjunctival lymphoid tissue is a vital basis for the further study of ocular surface inflammatory disorders. Therefore, we used immunohistochemistry to examine the leukocyte population of tarsal and bulbar conjunctiva from normal patients with no ocular or systemic inflammatory disease. CD3+ T cells were the most frequently occurring, and macrophages the second most frequently occurring, conjunctival cell type and were seen in the epithelium and substantia propria. There were greater numbers of leukocytes in the bulbar than in the tarsal area and this reached statistical significance for CD3+ T cells and CD57+ NK cells. In both bulbar and tarsal conjunctiva, B cells and neutrophils were seen in the epithelium and substantia propria, but plasma cells, NK cells and mast cells were present only in the substantia propria. No eosinophils were seen. CD8+ cells outnumbered CD4+ cells in the epithelium (CD4:CD8 0.3) but this was reversed in the substantia propria (CD4:CD8.1.3 tarsal, 2.0 bulbar). Most epithelial T cells and half the stromal T cells were CD45Ro+. IL-2R (CD25) staining was infrequent in the tarsal but not the bulbar area. The greater number and activation of T cells in the bulbar region may relate to greater antigen exposure. HLA-DR+ cells were mainly macrophages, but also included dendritic cells in the epithelium and a few epithelial cells. The conjunctival lymphocytes do have certain features of MALT cells, apart from mucosal recirculation, homing and promotion of sIgA production. Conjunctival IEL, like gut IEL, are predominantly CD8+, are found in the basal epithelium, are HML-1+, and have very high expression of CD45Ro. Substantia propria lymphocytes have more equal CD4 and CD8 numbers and frequently express CD45Ro. We found only one example of organised conjunctival lymphoid tissue in our study and suggest that the presence of CALT in humans is not universal.

Adolescent↗
PubMed1997

Comparison of 6F with 7F and 8F guiding catheters for elective coronary angioplasty: results of a prospective, multicenter, randomized trial.

A group of 460 patients was considered in our prospective study of assessment of the efficiency and safety of 6F (internal diameter 0.062 inches) guiding catheters to perform elective percutaneous coronary angioplasty by the femoral approach by using conventional balloon systems. The patients were randomly assigned either a 6F guiding catheter (first group, n = 231; 247 coronary lesions), or a 7F or 8F guiding catheter (second group, n = 229; 252 coronary lesions). The exclusion criteria were the ongoing myocardial infarction, the marked reduction of left ventricular function, and the decision to treat the lesion with a device not fitting the 6F guiding catheter. The angioplasty success rates (87% in the 6F group vs 88% in the 7F or 8F group) and the stent implantation rates (21% vs 25%) were similar in both groups. The ischemic complication rates (death, 2 vs 1 ) were also similar. The incidence of the femoral complications was significantly less important in the 6F group than in the 7/8F group (13.8% vs 23.5%; p < 0.01). Significant differences also were noted for the procedural time (36 +/- 22 vs 41 +/- 28 min; p < 0.01), the fluoroscopy time (11 +/- 10 vs 14 +/- 4 min; p < 0.05), the volume of contrast injected (136 +/- 68 ml vs 168 +/- 95 ml; p < 0.0001), and the time of femoral compression after the introducer sheath removal (11.7 +/- 9 vs 14.1 +/- 12 min; p < 0.01). Our data suggest that 6F guiding catheters for elective coronary angioplasty are more effective than are the larger diameter catheters. Besides a significant decrease of vascular complications, angioplasty with a 6F guiding catheter reduces the procedural time and the amount of contrast.

Angioplasty, Balloon, Coronary↗
PubMed1997

[Transthoracic echocardiography and diagnosis of acute pulmonary embolism. Change in the diagnostic valve with respect to thresholds of classification].

The diagnostic value of transthoracic echocardiography in acute pulmonary embolism is not well established. Although many parameters are abnormal, the thresholds used vary according to the authors, limiting the contribution of the investigation to the diagnosis. In a prospective study of 70 patients with suspected acute pulmonary embolism without previous cardio-respiratory disease, the authors tried to determine the diagnostic thresholds using discriminating linear analysis and ROC curves. Parameters easily recorded in an emergency were analysed: end diastolic ventricular dimensions, ratio of these diameters and maximal velocity of tricuspid regurgitant flow. Thirty-one patients had pulmonary embolism quantified by the Miller index (average: 16 +/- 7, range 2 to 28). Measurements of left ventricular dimension were disappointing (sensitivity: 0.52, specificity: 0.73 for a threshold value of 45 mm). The right ventricular dimension was a better predictive parameter (sensitivity: 0.70, specificity: 0.86 for a threshold value of 25 mm). However, the ratio of right to left ventricular dimension had a better diagnostic value (sensitivity: 0.85, specificity: 0.78 for a threshold value of 0.5). The best diagnostic parameter was the maximal velocity of tricuspid regurgitation (sensitivity: 0.93, specificity: 0.82 for a threshold value of 2.5 m/s). The authors conclude that the maximal velocity of tricuspid regurgitation with a threshold of 2.5 m/s and the ratio of the ventricular dimensions with a threshold value of 0.5 are valuable diagnostic indicators for acute pulmonary embolism.

Acute Disease↗
PubMed1997

Silent myocardial ischaemia and left ventricle hypertrophy in diabetic patients.

The purpose of this study was to evaluate the ability of three noninvasive techniques to detect silent myocardial ischaemia and analyse the factors associated with this condition, particularly left ventricular hypertrophy, in diabetic patients. An ECG stress test, a thallium-201 myocardial scintigraphy with dipyridamole intravenous infusion, ambulatory 48 h ECG monitoring and an echocardiographic study were performed in 92 diabetic patients without cardiac symptoms but with > or = 2 additional cardiovascular risk factors. At least one of these tests was positive in 28 patients (30.4%), suggesting silent myocardial ischaemia. Twenty-four of these patients had a coronary angiography which showed significant coronary stenosis in only 9 cases. An accurate echocardiographic tracing was obtained in 79 patients, particularly in 7 of the 9 with coronary stenosis. Left ventricular hypertrophy was detected in 34 patients, 6 of whom had coronary stenosis. In patients with left ventricular hypertrophy, the positive predictive values of myocardial scintigraphy and the ECG stress test were respectively 50% and 100%, as compared to only 33% and 11% in those without hypertrophy. In summary, coronary stenoses were found in < 10% of asymptomatic diabetic patients with > or = 2 cardiovascular risk factors, but more frequently in individuals with left ventricular hypertrophy. Thus, silent myocardial ischaemia should be searched for first in diabetic patients with hypertrophy, for which the stress test was the most accurate detection method in this study.

Adult↗
PubMed1996

Use of transthoracic Doppler echocardiography combined with clinical and electrocardiographic data to predict acute pulmonary embolism.

Transthoracic echocardiography and continuous wave Doppler were prospectively performed in 132 out-patients with suspicion of pulmonary embolism, and who had no previous history of severe cardiac or pulmonary disease. Bedside echocardiography determined diagnosis other than pulmonary embolism in 55 patients. Further study was completed in 70 patients; pulmonary embolism was found in 31 and excluded in 39. Significant differences were found as regards right ventricular diameter (27 +/- 8 vs 22 +/- 5 mm, P < 0.001), left ventricular diameter (41 +/- 9 vs 49 +/- 7 mm, P < 0.001), right over left ventricular diameter ratio (0.67 +/- 0.23 vs 0.43 +/- 0.15, P < 0.0001), tricuspid regurgitant flow peak velocity (2.9 +/- 0.4 vs 2.4 +/- 0.7 m.s-1, P < 0.0001), and abnormal septum motion (12 vs 4, P < 0.01). Multivariate analysis of echocardiographic data included a tricuspid regurgitant flow peak velocity greater than 2.5 m.s-1 and a right over left ventricular diameter ratio greater than 0.5 in a logistic model (sensitivity 93%, specificity 81%). The combination of echocardiographic and non-echocardiographic data included the two previous echocardiographic variables, together with signs of deep vein thrombosis, a deep S wave in lead D1, and a Q wave in lead D3 on the electrocardiogram in a logistic model (sensitivity 96%, specificity 83%). It can be concluded that emergency echocardiography, alone or combined with clinical examination and electrocardiogram, satisfactorily predicts acute pulmonary embolism.

Acute Disease↗
PubMed1996

Function and expression of endothelin receptor subtypes in the kidneys of spontaneously hypertensive rats.

OBJECTIVE: The renal endothelin system has been implicated in the development and maintenance of hypertension in spontaneously hypertensive rats (SHR). However, little is known about the function and cellular distribution of endothelin receptor subtypes in the kidneys of SHR. METHODS: We analyzed the expression of endothelin receptor subtypes in the kidneys of 16-week-old SHR using Scatchard analysis, receptor autoradiography, Northern blot analysis and in situ hybridization. Wistar-Kyoto rats (WKY) served as controls. Furthermore, we investigated the effects of the mixed (A/B) endothelin receptor antagonist bosentan and the ETA receptor antagonist BQ 123 on mean arterial blood pressure (MAP), renal blood flow (RBF) and glomerular filtration rate (GFR) in conscious chronically instrumented rats. RESULTS: In SHR, we found by receptor autoradiography an overexpression of the endothelin A receptor (ETA) in the glomeruli (2.2 +/- 0.4-fold; P < 0.05) and smooth muscle cells of intrarenal arteries (1.9 +/- 0.2-fold; P < 0.05) compared to age-matched WKY. In addition, our study revealed a pronounced upregulation of endothelin B receptor (ETB) in the glomeruli of SHR (5.6 +/- 0.8-fold; P < 0.01). Blockade of endothelin receptors in SHR with bosentan (A and B receptor blockade) as well as with BQ 123 (A receptor blockade) led to a significant decrease in MAP (-18.6 +/- 2.1 and -19 +/- 1.3 mmHg, respectively; P < 0.05 in both cases) and a significant increase in RBF (+2.8 +/- 0.5 and +3.1 +/- 0.37 ml/min, respectively; P < 0.05 in both cases). The blockade of both ETA and ETB by bosentan had no further effect on MAP reduction or RBF increase in SHR compared to the ETA blockade by BQ 123. The ETA antagonist BQ 123 had no effect on GFR either in SHR or in WKY, whereas the combined blockade of ETA and ETB by bosentan significantly decreased GFR in SHR by about 50% but not in WKY. CONCLUSIONS: Our data demonstrated a correlation between the overexpression of vascular ETA receptors and the pronounced upregulation of glomerular ETB receptors in the kidneys of SHR and their impact on the regulation of renal blood flow, glomerular filtration rate and blood pressure in these animals.

Animals↗
PubMed1996

[Value of transesophageal echocardiography in post-infarction septal ruptures].

The role of transoesophageal echocardiography in the diagnosis of ventricular septal defect in the acute stage of myocardial infarction, was evaluated in 15 consecutive patients (10 men and 5 women) with a mean age of 72 years in the period between June 1991 and April 1995. The patients had 11 anterior infarcts and 4 inferior infarcts with extension to the right ventricle. One patient was in Killips class I,7 patients in class II, 2 in class III and 5 in class IV. Only 8 of the 15 septal ruptures could be visualised directly by conventional transthoracic echocardiography, though all 15 were suspected from continuous Doppler and colour Doppler analysis. Transoesophageal echocardiography was successfully performed in 14 of the 15 patients with a monoplane probe in 11 cases and a multiplane probe in 3 cases. The average duration of the procedure was 12 minutes and clinical and haemodynamic tolerance was good. Ventricular septal defect was directly visualised in all cases in the short axis transgastric view and in 7 cases in transoesophageal views. Transoesophageal echocardiography was concordant with peroperative findings with regards to the site of ventricular septal defect (8 apical, 5 postero-basal and 1 median), their type (6 punched-out defects, 5 fissures, and 3 perforated aneurysms), their size (average 9.3 mm), their number with 5 multiple defects, and associated lesions (4 right ventricular extensions, 4 hemopericardiums and 1 free wall fissure). Transoesophageal echocardiography completes traditional transthoracic echocardiographic examination in the diagnosis of post-infarction ventricular septal defect. It is well tolerated and, in the authors' experience, allows limitation of invasive procedures to coronary angiography alone.

Aged↗
PubMed1996

[Estimation of left ventricular volumes and ejection fraction with acoustic quantification in myocardial infarction. Comparison with echocardiographic, angiographic and scintigraphic data].

The object of this study was to assess the reliability of measurements of left ventricular volumes and ejection fraction by acoustic quantification by the method of summation of discs in acute myocardial infarction. Thirty-two patients with an average age of 55.9 +/- 12 years were studied prospectively on average 6 +/- 2 days after the onset of myocardial infarction. Within 48 hours, the patients underwent TM echocardiography (Teichholz's method) two-dimensional echocardiography (Simpson's method on freeze frames and acoustic quantification) before left ventricular angiography and isotopic ventriculography, considered as the reference methods for comparing left ventricular volumes and ejection fractions. The data displayed in real time by acoustic quantification correlated well with the results of left ventricular angiography (r = 0.77; p = 0.0001) and moderately underestimated (+4.1 +/- 11.9%) the ejection fraction, but were relatively disappointing for estimating volumes. When compared with isotopic ejection fraction, the correlation coefficient was r = 0.71 (p = 0.0004) and the values were overestimated. In this study, acoustic quantification was the most reliable echocardiographic method of assessing the left ventricular ejection fraction with reference to contrast angiography (Teichholz: r = 0.56; p = 0.0014; Simpson: r = 0.76; p = 0.001). The authors conclude that assessing the left ventricular ejection fraction with acoustic quantification is reliable in acute myocardial infarction. However, the method is not very accurate in measuring end systolic and end diastolic volumes.

Acoustics↗
PubMed1996

[Ventricular late potentials and sleep apnea syndromes].

This prospective study in 37 patients evaluated the prevalence of ventricular late potentials in sleep apnea syndrome, a condition associated with an increased risk of ventricular rhythm disorders and sudden death. A comparative analysis was conducted among a group of patients considered free of coronary heart disease and admitted for suspected sleep apnea syndrome based on clinical symptoms and simple blood gas measurements. The prevalence of ventricular late potentials was 56% in the subgroup with and 14% in the subgroup without polygraphy evidence of apnea (F < 0.01). The analysis of clinical, respiratory, and echocardiographic findings in the apneic subgroup failed to detect any factors associated with the presence of ventricular late potentials. Only long-term follow-up studies involving invasive heart rhythm testing could define the prognostic significance of ventricular late potentials in sleep apnea syndrome. However, our data demonstrate that there is an association between ventricular late potentials and sleep apnea syndrome.

Adult↗
PubMed1995

Diagnostic accuracy of echocardiography-Doppler in acute pulmonary embolism.

We studied prospective recording of clinical, electrocardiographic, Doppler and echographic parameters in 32 patients with proven pulmonary embolism, matched with 32 patients with clinically suspected pulmonary embolism and normal perfusion scan or angiography. Thirty-seven per cent of cases and 16% of control subjects had clinical signs of right ventricular overload; S1-Q3-T3 ECG pattern was found in 11 cases and one control. Other clinical and ECG parameters did not reach significant difference. Echographic septum motion was abnormal in 42% of cases and 9% of controls (P < 0.05), end-diastolic right ventricular diameter was > 25 mm in 67% of cases and 11% of controls, ratio of end-diastolic right over left ventricular diameters increased over 0.6 in 67% of cases and 11% of controls, while Doppler examination found tricuspid regurgitant peak flow velocity > 2.5 m/s in 84% of cases vs. 10% of controls. According to these parameters, Doppler-echocardiography was normal in 6% of cases and 87% of control subjects (P < 0.001 for each). In suspected pulmonary embolism, our study shows that Doppler-echocardiography may be both sensitive and specific in emergency conditions and help the decision making for further invasive investigations.

Acute Disease↗
PubMed1995

Randomized evaluation of six French voda-type guiding catheters for left coronary artery balloon angioplasty.

In order to evaluate 6 French (6F) Voda-type guiding catheters for left coronary artery balloon angioplasty, we randomized the choice of the guiding catheter in 100 consecutive patients between a Voda (group 1, n = 50) and a Judkins or Amplatz curve (group 2) guiding catheter. Angioplasty success rate (98% for both), need for guiding catheter crossover exchange (2 in group 1 vs. 1 in group 2), fluoroscopy time, and volume of injected contrast were similar in both groups, but the operator's appreciation of good back-up support was better with the Voda-type guiding catheter (90% vs. 74%, P < 0.05). No complications attributed to the guiding catheter were noted in either group. Efficiency of the Voda-type guiding catheter appeared similar for both left anterior descending (n = 35, success rate 100%) and circumflex (n = 18, success rate 94%) coronary artery angioplasty. Voda-type guiding catheters are an efficient and safe approach to routine left coronary angioplasty. They appear to be as effective as a choice between a Judkins or an Amplatz configuration and could be of particular use when a double angioplasty of the left anterior descending and circumflex arteries is attempted during the same procedure.

Angioplasty, Balloon, Coronary↗
PubMed1995

Coronary angioplasty of bifurcational lesions with the protecting branch technique using 6 French guiding catheter.

The use of 6 French guiding catheters is still usually limited to elective percutaneous transluminal coronary angioplasty. We describe our preliminary experience with this guiding size to perform a double guide wire procedure for angioplasty or coronary bifurcation lesions, to protect (n = 5) and/or to sequentially dilate (n = 9) a major side branch. Technical success was 12/14 (86%), angiographic success 13/14 (93%), and in-hospital outcome was event free in all patients. Thus, 6 French guiding size is both safe and effective for the majority of coronary bifurcation angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1995

[Transesophageal echocardiographic diagnosis of left ventricular parietal rupture, a complication of myocardial infarction].

The authors report the case of postero-lateral myocardial infarction complicated by free wall rupture at the 48th hour. The diagnosis was suspected clinically and transoesophageal echocardiography showed the appearance of pericardial effusion in a patient difficult to examine by conventional echocardiography. Transoesophageal echocardiography was performed and well tolerated. The transgastric view showed a thrombus adjacent to a thinned and lacerated postero-lateral wall. The clinical outcome was favourable after surgical repair.

Echocardiography, Transesophageal↗
PubMed1995

[Evaluation of the systematic use of wide lumen 6 French guiding catheters in conventional coronary angioplasty].

The aim of this study was to evaluate the results of systematic use of 6 French guiding catheters in conventional balloon coronary angioplasty without any restriction of indications apart from coronary lesions necessitating other techniques such as atherectomy. Therefore, after a learning period, 200 consecutive procedures performed between November 1993 and June 1994 for the treatment of 234 lesions were analysed prospectively. Fifty-one patients had stable and 70 unstable angina. In 79 cases, the angioplasty was performed on the culprit lesion of a myocardial infarction. An angiographic success was obtained for 206 lesions or 88% of cases which increased to 95% after exclusion of attempted recanalisation. There were 3 cases of damage to the ostium and 7 patients underwent implantation of a stent with the same catheter for occlusive or threatening dissection. There were 10 ischaemic complications (5%) (7 non-Q wave infarctions, 2 Q wave infarctions, 1 aorto-coronary bypass, no deaths) and 8 local complications at the site of arterial catheterisation during the hospital period. These results demonstrate the feasibility of coronary angioplasty with wide lumen 6 French guiding catheters and show that they amy be used in first intention for all conventional balloon angioplasty procedures.

Adult↗
PubMed1995

Significance of endothelin receptor subtypes in the kidneys of spontaneously hypertensive rats: renal and hemodynamic effects of endothelin receptor antagonists.

The renal endothelin (ET) system has been implicated in the maintenance of hypertension in spontaneously hypertensive rats (SHRs). However, little is known about the expression and cellular distribution of the ET receptor subtypes in the kidney of SHRs. We therefore analyzed the expression of ET receptor subtypes in the kidneys of 16-week-old SHRs. Wistar-Kyoto (WKY) rats served as controls. Furthermore, we investigate the effects of the ETA receptor antagonist BQ 123 and the mixed (ETA/ETB) receptor antagonist bosentan on mean arterial blood pressure (MAP), renal blood flow (RBF), and glomerular filtration rate (GFR) in conscious, chronically instrumented rats. In SHRs we found overexpression of the ETA in the glomeruli and smooth muscle cells of intrarenal arteries compared to age-matched WKY rats. Furthermore, our study revealed a pronounced upregulation of the ETB in the glomeruli of SHRs. Blockade of ETA and ETB receptors in SHR with bosentan as well as with BQ 123 led to a significant decrease in MAP and a significant increase in RBF, indicating that the ETA receptor plays a major role in the maintenance of high blood pressure and the regulation of RBF in SHRs. The blockade of both ETA and ETB receptors by bosentan has no further effect on MAP reduction or increase in RBF in SHRs compared to ETA blockade by BQ 123. In contrast, combined blockade of ETA and ETB receptors by bosentan significantly decreased GFR in SHRs, whereas no effect on GFR was observed in WKY rats, suggesting that the glomerular ETB overexpression in SHRs is of pathophysiologic relevance.

Animals↗
PubMed1995

[Pulmonary embolism and thrombi of the right heart].

In general, there are two types of right heart thrombi diagnosed by echocardiography: mobile and non-mobile thrombi, more often located in the atrium than in the ventricle and a potential source of pulmonary embolism. However, they differ in several points: clinical context, clinical and echocardiographic presentations, embolic potential, prognosis and treatment. The result of peripheral venous thrombosis, mobile thrombus it is usually diagnosed during echocardiographic investigation of pulmonary embolism. The appearances are often that of serpentine thrombus floating in the right heart chambers associated with signs of acute cor pulmonale. It is a marker of imminent and often fatal embolism as it completes a previous and usually severe pulmonary embolism; the mortality is over 40%. It is a contra-indication for pulmonary angiography because of the risk of embolism and a therapeutic emergency. Some groups advocate surgical embolectomy and others thrombolysis. Its precise frequency in the acute stage of pulmonary embolism and its treatment remain to be determined by a prospective, multicentre clinical trial. The adherent non-mobile thrombus is usually implanted on the free wall of the right atrium or the interatrial septum. Its formation, in situ, is due to stasis secondary to decompensated congenital or acquired cardiac disease or to the presence of an intracardiac foreign body such as a pacing wire. It is less likely to cause pulmonary embolism. It decreases or disappears with anticoagulant therapy and the outcome is usually good. The differential diagnosis between a mobile thrombus and a Chiari network, or between an adherent thrombus and a vegetation on a intracardiac pacing wire may be difficult and requires transoesophageal echocardiography. The investigation of pulmonary embolism requires systematic echocardiography, one of the objectives of which is to search for right sided thrombi.

Anticoagulants↗
PubMed1994

[Cardiac anomalies in disseminated lupus erythematosus diagnosed by Doppler ultrasonography. Prevalence and association with antiphospholipid syndrome].

OBJECTIVES: Antiphospholipid antibodies in patients with systemic lupus erythematosus (SLE) are widely associated with thrombosis, recurrent abortions and a thrombocytopenia. The purpose of this study was first to evaluate the prevalence of cardiac abnormalities in patients with SLE and secondly to establish the relationship between the findings and the presence of an antiphospholipid syndrome. SUBJECTS AND METHODS: First of all, a total of 52 consecutive patients with SLE and 52 healthy sex-and-age-matched control subjects were evaluated in a cross sectional study. All underwent M mode and two dimensional echocardiography, color flow imaging, pulsed and continuous wave Doppler. Secondly, in the SLE group, subjects exposed to antiphospholipid syndrome (n = 20) were compared to the control subjects. RESULTS: Compared with the control group, patients with SLE had significantly more pericardial abnormalities [(p = 0.0006) RR [3.36-infinity], mitral regurgitation [(p = 0.032) RR 2.48 [1.25-5.6]], tricuspid regurgitation [(p = 0.0016) RR 2.41 [1.58-8.85]. There was no significant difference between both groups for the left ventricular mass (p = 0.07), posterior wall (p = 0.25) and interventricular septum dimension (p = 0.16), and mitral valve thickness (p = 0.66). The antiphospholipid syndrome was significantly associated with increased left ventricular mass (p = 0.0054), posterior wall (p = 0.022) and interventricular septum dimension (p = 0.026). The relative risk increased for tricuspid and pulmonary regurgitation in SLE patients who had the antiphospholipid syndrome. CONCLUSION: The prevalence of left ventricular hypertrophy and right heart valvular regurgitation is significantly raised in SLE patients who have the antiphospholipid syndrome. However, antiphospholipid syndrome does not modify the prevalence of pericardial abnormalities which seems to be due to SLE alone.

Adult↗