Search PubMed⌕ Search

Biomedical subjects

F Leclercq

Publications and source records attributed to F Leclercq.

At least 73 records · Page 4Linked to original sources
PubMed1993

Heart transplantation for terminal congestive heart failure in an acromegalic patient.

Dilated hypokinetic cardiomyopathy in an acromegalic patient is an uncommon event. Specific hormonal therapy with octreotide (a somatostatin analogue) is now recognized as able to improve cardiac failure. A case of worsening of cardiac function under such a therapy is described in this report. Octreotide was finally discontinued and a cardiac transplantation performed. Soon after surgery, treatment with octreotide was started again and no other adverse reaction was noticed. Furthermore, no deleterious or synergistic interaction between the somatostatin analogue and cyclosporine A was detected. A pharmacological hypothesis is given to explain the inability of octreotide to counteract cardiac failure. The patient died 6 months after surgery probably because of an acute episode of arrhythmia.

Acromegaly↗
PubMed1993

[Ventricular tachycardia in children].

Ventricular tachycardia (VT) in children is different to that observed in the adult because ischemic heart disease is exceptionally rare in this age group. The arrhythmia sometimes presents with cardiac failure or loss of consciousness. VT complicates the outcome of operated Tetralogy of Fallot, arrhythmogenic right ventricular dysplasia and some cardiac tumours. Cardiomyopathies are also a cause of VT but it must be noted that ventricular dysfunction may be the result of a prolonged arrhythmia and will disappear after return to sinus rhythm. Many cases of childhood VT occur without any patent cardiac disease even after extensive investigations. Some are benign with a good prognosis, such as salvoes of VT or sustained attacks of so-called ventricular Bouveret. Others carry a more reserved prognosis and require active treatment. Incessant tachycardia of the newborn is difficult to stop may be cured without sequellae. Torsades de pointes is sometimes iatrogenic complicating congenitally long QT syndromes with or without deafness or familial nature, and which may be likened to adrenergic VT. Amiodarone and betablockers are the best antiarrhythmic agents. Investigations with a diagnostic or therapeutic objective are easier in older children but these techniques, whilst not being systematic, do not exclude the very young children. Ablation techniques progress and the limited indications of surgery and implantable defibrillators have to be considered case by case.

Adolescent↗
PubMed1993

Doppler echocardiographic evaluation of the Omnicarbon cardiac valve prostheses.

Comprehensive 2 D/Doppler examination of 98 patients (mean age 56), implanted between September 1984 and February 1991, with normally functioning aortic (n = 49) and mitral (n = 49) Omnicarbon valves (OC) were analyzed in order to characterize the normal hemodynamic profiles of the OC valves. The mean time from implantation was 36.4 months (range 6 to 78). The following parameters were assessed (average of 5 measurements): peak transvalvular velocity (peak V), peak instantaneous gradient (peak G), mean transvalvular gradient (mean G), effective aortic valve area (ef Va), modified aortic valve area (m Va), aortic permeability index (PI), mitral valve area (Mit Va). Doppler data were correlated to prosthetic sizes (ranging from 21-29 mm for aortic OC and from 23-31 mm for mitral OC). The study establishes normal Doppler hemodynamics for each size (especially in aortic position) of OC valves and shows excellent performance. Significant correlations between peak G, mean G, Pl, and prosthetic aortic valve size (AS) were moderate. By contrast there were strong relationships between AS and ef Va (r = 0.56, p < 0.001) or mVa (r = 0.55, p < 0.001). These data should be helpful to identify OC prosthetic dysfunction.

Adolescent↗
PubMed1993

[Dilated cardiomyopathy in acromegaly worsening under octreotide treatment. Apropos of a case].

Dilated cardiomyopathy associated with acromegaly is rare, but may improve with octreotide, a somatostatin analogue. The authors give the first description here of paradoxical worsening in cardiac function during such treatment, with the onset of episodes of acute decompensation following each attempt at starting treatment. Thus worsening was confirmed objectively by a challenge test with octreotide: increased dyspnea, fall in shortening fraction and in echocardiographic cardiac output (of 17 to 14% and 4 to 3 l/min respectively), a decrease in isotopic ejection fraction from 15 to 6% and this in parallel with efficacy regarding hormone levels of GH and IGF1 and a reduction in tumour size by CT scan. No further episode of decompensation occurred after treatment was stopped permanently. The patient underwent a transplant 3 months later. Suppression of the positive inotropic effect of GH by octreotide, associated with an increase in peripheral resistance is suggested. A negative inotropic effect of this hormonal analogue on too advanced a case of heart disease is also a possibility.

Acromegaly↗
PubMed1993

Cardiac-specific immunoenzymometric assay of troponin I in the early phase of acute myocardial infarction.

The screening by immunoenzymometric assay (IEMA) of 784 monoclonal antibody (MAb) combinations resulted in the selection of an optimal pair of MAbs for measuring human cardiac troponin I (TnI). Using a one-step IEMA described here, we were able to detect TnI within the range of 0.2-20 micrograms/L in 30 min at room temperature. No cross-reactivity was observed with the skeletal isoforms of troponin up to a concentration of 500 micrograms/L. This assay was used to measure cardiac TnI in the plasma of 43 patients with acute myocardial infarction (AMI). TnI was detected relatively early after the onset of chest pain (4.3 +/- 2.1 h, mean +/- SD); the peak occurred after 12.2 +/- 4.6 h in a population that had undergone fibrinolysis. TnI disappearance was generally observed between 5 and 9 days after the onset of chest pain. No cardiac TnI could be detected in 145 healthy donors or in a control group of 6 patients (with skeletal damage or rhabdomyolysis). This assay allows a specific diagnosis of AMI in its early acute phase, with a high diagnostic specificity and sensitivity.

Adult↗
PubMed1992

Magnetic resonance imaging of the saccular otolithic mass.

The frog's inner ear was studied in vivo by high spatial resolution magnetic resonance imaging at 7 Tesla. The vestibule, the internal acoustic meatus, and the auditory tube have been identified. The large otolithic mass contained in the vestibule showed a virtual absence of magnetic resonance signal probably due to its composition of closely packed otoconia.

Animals↗
PubMed1992

[Electrocardiography of atrioventricular block].

A functional physiological block protects the ventricles from the risks of excessively rapid atrial rhythms. Pathological AVB is classified in three degrees according to whether the ventricular excitation is delayed, intermittent or absent. The site of AVB can be accurately determined by endocavitary electrophysiological studies but can also be estimated from the surface electrocardiographic recordings. fundamental research has questioned the sle responsibility of conduction defects in Wenckebach and paroxysmal blocks: they suggest the presence of abnormalities of excitability in pathological zones.

Bradycardia↗
PubMed1992

Magnetic resonance imaging of semicircular canals.

The present paper reports the results of the first investigation of the semicircular canals in a living, small animal by means of high spatial resolution magnetic resonance imaging. This procedure is noninvasive and allows identification of the endolymphatic and perilymphatic spaces yielding a morphology quite consistent with direct anatomical examination.

Animals↗
PubMed1991

[Traumatic atlanto-occipital dislocation].

Traumatic atloido-occipital dislocation is usually fatal with immediate cardio-respiratory arrest. The authors report 3 cases of children who survived such a spine injury despite neurological impairment. Clinical and radiological data including Magnetic Resonance Imaging are compared with 18 other cases reported in the literature.

Atlanto-Occipital Joint↗
PubMed1991

The correlation between magnetic resonance imaging and ultrastructural patterns of brown adipose tissue.

The present paper reports on magnetic resonance imaging (MRI) at high spatial resolution of the brown adipose tissue (BAT) in laboratory rodents, in comparison with light and electron microscopy findings. Our aim was to assess whether MRI correlates with the expected ultrastructural differences between newborn and adult BAT. The study was performed on the cervical and the interscapular BAT deposits by means of a nuclear magnetic resonance (NMR)-spectrometer equipped with a high resolution imaging system. Ultrastructural examination of BAT at different ages showed three different patterns of adipocyte ultrastructure in BAT which were associated with different MRI patterns. In BAT, MRI identifies the prevalent type of adipocyte in the tissue providing information consistent with ultrastructural results. Results presented here show that MRI represents a precise and reliable tool to investigate the morphology of tissues in living animals. The safe, non-invasive MRI technique represents a very useful tool in morphological research.

Adipose Tissue, Brown↗
PubMed1991

Age-related modification in the thymus of rats and mice: an in vivo study by magnetic resonance. MR imaging of the thymus.

Techniques of magnetic resonance were used to investigate in vivo the normal thymus and its age-related modifications in small rodents. The data were compared with anatomical preparations and histological sections of the animals. The possibility to visualize modifications of the thymus in living organisms open new perspectives for the follow up of experimental manipulations on laboratory animals.

Age Factors↗
PubMed1989

Morphological identification of brown adipose tissue by magnetic resonance imaging in the rat.

Morphological distinction between brown and white adipose tissue was obtained in the rat by MRI at 7 Tesla. Both superficial (subcutaneous) and deep (mediastinal) brown fat was visualized; the level of resolution was less than 1 mm. These results show that MRI is a potentially useful tool for studying the biology of brown adipose tissue in the experimental animal and, prospectively, in man.

Adipose Tissue↗
PubMed1988

[Doppler color echocardiography in the diagnosis of 4 septal perforations complicating anterior myocardial infarction].

The 4 cases reported here are meant to illustrate the value of colour doppler-echocardiography in the diagnosis of ventricular septal rupture consecutive to an anterior myocardial infarction. With this method, the examination begins with colour doppler ultrasound superimposed on two-dimensional echocardiographic images and is completed by pulsed and continuous wave doppler velocimetry. In all 4 patients an abnormal colour doppler flow was visualized from the outset; it started in the left ventricule and crossed the ventricular septum to enter the right ventricule, thus confirming the diagnosis and locating the septal defect. This abnormal flow was easy to recognize. On the apical "4 cavity" projection it followed a semi-circular anti-clockwise course which occurred at each cardiac cycle. The flow was red at first in presystole at the apex of the left ventricule; it became blue in pre- and middle-systole while traversing the septum, then mosaic-like in middle- or end-systole around the septal defect on the right ventricular side, and finally blue again in pre-diastole within the right ventricle. The blue trans-septal flow persisted at least up to pre-diastole. The diagnosis of septal rupture was confirmed at surgery in 3 cases and at right heart catheterization in 1 case. Colour doppler-echocardiography is a simple, efficient and rapid method, superior to contrast echocardiography or pulsed doppler alone, for direct real-time visualization of the shunt. It makes the septal defect easy to locate, and it avoids invasive exploratory manoeuvres in cases where surgery is contra-indicated and/or when coronary angiography is not mandatory.

Aged↗
PubMed1986

Effect of omega-trifluorination on the microsomal metabolism of ethyl and pent-1-yl p-nitrophenyl ether.

p-Nitrophenyl pent-1-yl ether was metabolized (65-70%) in the presence of liver microsomes from phenobarbital-treated rats to give the 4-(major), 3-(minor), and 2-hydroxypent-1-yl (minor) derivatives which were characterized by g.l.c.-mass spectrometry; O-dealkylation (reflecting 1-hydroxylation) and 5-hydroxylation did not occur to a significant extent. 5,5,5-Trifluorination of the pent-1-yl group markedly reduced the extent of metabolism (to approximately 10%). p-Nitrophenyl 2,2,2-trifluoroethyl ether was virtually completely resistant to microsomal metabolism under conditions where the ethyl analogue was extensively O-dealkylated.

Animals↗