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Biomedical subjects

D Lallemand

Publications and source records attributed to D Lallemand.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Imaging of joints in children].

Magnetic resonance imaging (MRI) has became the technique of choice for noninvasive imaging of the joint in the child, owing to its high tissular contrast. Through injection of paramagnetic contrast media, MRI allows a precise analysis of the synovial inflammation, of the cartilage and of the joint effusion. It offers a precise evaluation of the local activity of the disease. It guides and provides monitoring of local treatment in juvenile chronic arthritis and haemophilic arthropathy. The technique is very sensitive but lacks specificity. Its use is complementary to clinical examination and standard radiography techniques, which remain the initial investigations.

Adolescent↗
PubMed1994

Mouse JunD negatively regulates fibroblast growth and antagonizes transformation by ras.

As NIH 3T3 fibroblasts become quiescent, the level of c-Jun protein decreases while JunD accumulates. When resting cells are stimulated with fresh serum, nuclear-localized JunD is rapidly degraded, followed by resynthesis of both c-Jun and JunD later in G1. Overexpression of JunD results in slower growth and an increase in the percentage of cells in G0/G1 while c-Jun overexpression produces larger S/G2 and M phase populations. In addition, JunD partially suppresses transformation by an activated ras gene whereas c-Jun cooperates with ras to transform cells. These data indicate that two closely related transcription factors can function in an opposing manner.

Amino Acid Sequence↗
PubMed1994

Gadolinium-DOTA enhanced MRI of painful osseous crises in children with sickle cell anemia.

In order to evaluate the role of gadolinium-DOTA enhanced MRI in the management of painful osseous crises in children with sickle cell anemia (SCA), nine children with SCA underwent MRI, bone scans and ultrasonographic studies during 11 osseous crises. Imaging findings were compared with the final diagnosis: three acute osteomyelitis (AO) and 16 acute infarcts (AI). MRI could not differentiate AO from AI. The appearance of severe AI was very misleading and was similar to the usual appearance of AO, including soft tissue changes, periosteal reaction and patterns of enhancement. Gadolinium-DOTA enhanced MRI was useful for determining the anatomic site and extent of AO or AI and for distinguishing between necrotic material, fluid collection and vascularized inflammatory tissue. It can also help to guide the aspiration of intraosseous, subperiosteal and soft tissue fluid collections.

Acute Disease↗
PubMed1994

Bronchopulmonary dysplasia: value of CT in identifying pulmonary sequelae.

OBJECTIVE: Pulmonary dysfunction is common in children who survive bronchopulmonary dysplasia. Chest radiographs are not satisfactory for the identification of the sequelae of bronchopulmonary dysplasia because, although they often show abnormalities, the abnormalities are usually minor and sometimes absent. We therefore assessed the value of CT for identifying the sequelae of bronchopulmonary dysplasia. MATERIALS AND METHODS: Twenty-three children (mean age, 4 years) who had survived neonatal bronchopulmonary dysplasia and had signs of chronic pulmonary dysfunction (recurrent episodes of coughing, wheezing, dyspnea, pneumonia, respiratory insufficiency) were examined with chest radiographs and high-resolution CT scans of the chest. Two reviewers qualitatively analyzed the chest radiographic and CT findings by describing the most consistently found lesions and their frequencies. RESULTS: The chest radiographs showed hyperexpansion in 17, hyperlucent areas in 11, and linear opacities in 10 of the 23 children. Pleural thickening was not observed, and four children had normal findings on chest radiographs. All 23 CT scans showed abnormalities, including multifocal areas of hyperaeration, well-defined linear opacities, and triangular subpleural opacities with an external base and an internal apex. In 20 of 23 children, all three abnormalities were present. For the three other children, two of these three abnormalities were found. No bronchiectasis was observed in any of the cases. CONCLUSION: Lesions in survivors of bronchopulmonary dysplasia with chronic pulmonary dysfunction are visualized better on CT scans than on chest radiographs. Importantly, CT findings of multifocal areas of hyperaeration, numerous linear opacities facing triangular subpleural opacities visible on several consecutive sections, and no bronchiectasis should suggest the presence of sequelae of bronchopulmonary dysplasia.

Bronchopulmonary Dysplasia↗
PubMed1993

Pediatric spinal bone marrow: assessment of normal age-related changes in the MRI appearance.

A retrospective study of 100 children (0-15 years) without known bone marrow abnormality, was performed to elucidate the spectrum of the MRI appearance of spinal bone marrow with age on T1-weighted images at 0.5 T. Fatty marrow distribution and vertebral signal intensity (SI) relative to disk SI were noted in each subject, and allowed the identification of distinctive patterns. The spinal marrow patterns and their relative frequency for different age groups were consistent with the known physiologic conversion from cellular to fatty marrow with age. Between the ages of 0 and 1 year, SI of corporeal ossification centers was similar or lower than SI of adjacent cartilage and disk in 87% of cases. Between the ages of 5 and 15 years, vertebral SI was higher than SI of adjacent disks in 90% of cases. A central or basivertebral zone of high SI consistent with focal fatty marrow was found in 16% and 31% of cases respectively. In conclusion, knowledge of these conversion patterns should serve as a practical aid in the interpretation of MRI examinations of the spine in children.

Adolescent↗
PubMed1993

Computed tomography with normal chest radiograph in tuberculous infection.

Children with primary tuberculosis infection without disease must be identified and treated preventively to avoid an increase in the incidence of tuberculosis in children. However, the recognition of infected cases without disease is often difficult. In particular, minimal active disease may be present in many cases but unrecognised on chest radiography. Computed tomography was therefore performed in 15 children with tuberculous infection and a normal chest radiograph to measure the size of their mediastinal lymph nodes. Ten control children without tuberculosis were also evaluated. When compared with controls it was found that nine of 15 (60%) infected children had enlarged lymph nodes. Adenopathies were more frequent in infected children less than 4 years old than in those over 8 years old. The demonstration of unrecognised active disease in many infected children raises the question of the adequate treatment for these children. It is proposed that a two drug regimen would be more appropriate than isoniazid alone in these cases.

Adolescent↗
PubMed1993

Old renal transplants examined by Doppler ultrasonography.

Twenty-four ultrasonography (US) studies of 21 renal transplants that had been in place for 1 to 19 (median 3) years were evaluated. The absolute resistive indices (RIs) determined during Doppler US at various arterial levels and the differences in RI between the levels did not correlate with the clinical diagnosis of chronic rejection. This study suggests that measuring RI values with Doppler US in people who received renal grafts as children does not currently contribute additional information for diagnosis or management.

Adolescent↗
PubMed1993

[Contribution of imaging techniques in acute neonatal renal pathology].

Ultrasound is the first imaging modality used to evaluate acute renal disease in neonates. Normal findings and abnormalities seen in venous or arterial thrombosis, hemodynamic shock, or sepsis are reviewed. Transient changes due to intoxications, tubular disorders, or congenital nephrotic syndrome are considerably less common.

Acute Disease↗
PubMed1993

Doppler ultrasonography in the early postoperative evaluation of renal transplants in children.

The renal ultrasonography (US) scans of 23 children who had recently undergone kidney transplantation were reviewed; the studies included Doppler US scanning of the arterial vessels at several levels. There were 43 studies for children whose postoperative course was normal; 16 studies were obtained during episodes of acute tubular necrosis and 21 during episodes of acute rejection. The upper limit of normal for the resistive index (RI) at the arcuate artery is higher (up to 0.79) for a pediatric renal transplant patient than for adults with normal kidneys, regardless of the age of the kidney donor. Therefore, elevation of the RI to 0.80 or higher or complete loss of diastolic flow always indicates a complication of transplantation. Abnormally high RI values were seen in patients with both acute tubular necrosis and acute rejection; however, the RI value as determined by US did not distinguish these two entities. In addition, in 7 cases of acute tubular necrosis and 12 of acute rejection the RI was normal (0.58 to 0.79).

Adolescent↗
PubMed1992

[Magnetic resonance imaging of the normal and the pathological knee in the child].

The results of magnetic resonance imaging (MRI) studies performed on the knee region of 60 children including 20 normally growing subjects are reported. In healthy children, MRI permitted to study the normal maturation of bone marrow and cartilaginous structures. The patients studied had bone tumors (11 patients), rheumatoid arthritis (8 patients), lesions of traumatic origin (7 patients), osteochondritis (4 patients), vascular and tissular dysplasia (3 patients), osteomyelitis (3 patients) and soft-tissue tumors (3 patients). In all patients, MRI showed clinically relevant abnormalities that were not detected by conventional X-rays or physical examination. MRI offers the ability to study disorders of bone, bone marrow, cartilage, menisci and ligaments in a noninvasive way. MRI has replaced arthrography of the knee and is the examination of choice in pediatric patients.

Adolescent↗
PubMed1991

The value of flexible bronchoscopy in childhood pulmonary tuberculosis.

The value of 121 flexible bronchoscopy (FB) procedures was evaluated in 54 children, aged three months to 14 years, suspected of having pulmonary tuberculosis. Specimens from FB were culture-positive for Mycobacterium tuberculosis in seven of the 13 bacteriologically confirmed cases. Bronchial abnormalities consistent with the diagnosis were found in 31 of 54 cases. Separate or coexistent findings at initial FB included airway compression (20 cases), granulation tissue (ten cases), and obstructive caseum (four cases). Chest roentgenograms underestimated bronchial involvement in 14 children. Further FB monitoring documented disease evolution. The FB was important in the management of patients, as it (1) guided the use of prednisone therapy, especially in the children with a chest roentgenogram not suggestive of bronchial involvement; (2) indicated a need for resection of granulation tissue by rigid bronchoscopy (three cases); and (3) guided the surgical decision (two children with persistent bronchial obstruction). Thus, FB is a safe and valuable procedure in the management of childhood pulmonary tuberculosis.

Adolescent↗
PubMed1990

Splenosis simulating an abdominal lymphoma.

Splenosis, an autograft of splenic tissue, may occur after a traumatic spleen rupture or splenectomy. Usually asymptomatic, this pathology may uncommonly produce symptoms which justify radiologic investigations. We are presenting the case of a young boy with a Wiskott Aldrich syndrome and who developed splenosis simulating an abdominal lymphoma.

Abdominal Muscles↗
PubMed1990

Metastatic pulmonary calcifications after cardiac surgery in children.

Six children in whom pulmonary calcifications developed after open heart surgery are described. Asymptomatic alveolar lesions appeared within the first 3 weeks after surgery, during or after intensive care. They were first diagnosed as possible infection or edema and secondarily identified as calcifications in the lungs. In five patients, the pulmonary calcifications partially decreased or disappeared, and the prognosis did not seem to be altered. In one patient, the pulmonary calcifications were associated with cardiac calcifications leading to death. The mechanism of these pulmonary calcifications is thought to be predominantly or exclusively metastatic and partially iatrogenic. Data indicated two major causative factors: therapy with massive doses of calcium and postsurgical acute renal failure. Radiographic findings of persistent alveolar lesions of increasing density in patients undergoing antibiotic therapy after open heart surgery are suggestive of the diagnosis of metastatic pulmonary calcifications. Scintigraphy with bone agents or computed tomography is recommended for early confirmation and prevention of therapeutic errors, especially after cardiac transplantation.

Acute Kidney Injury↗
PubMed1990

[Radiologic aspects of pulmonary aspergillosis in chronic septic granulomatosis in children. Apropos of 17 cases].

The authors describe the radiological aspects of pulmonary aspergillosis in chronic granulomatous disease in children. The radiological anomalies reveal the aspergillosis in 35% of the cases. Association of alveolar opacities, chronic peripheral, sometimes bilateral, with localized pleural thickening must raise the diagnosis. CT scan allows an early diagnosis of parietal and mediastinal involvement and can show invisible lesions on standard chest film.

Adolescent↗
PubMed1989

Pancreatic venous samplings in infants and children with primary hyperinsulinism.

The authors present 19 cases of hyperinsulinism in children worked up with selective pancreatic venous samplings (PVS). Focal lesions were found in 7, diffuse secretion in 8 and normal insulin levels in 4. In three patients with focal hypersecretion less extensive surgery could be performed and confirmed the presence of focal lesions in two. These preliminary results are encouraging and PVS seems to be a valuable technic for detection of focal lesions in the pancreas of children with hyperinsulinism.

Adenoma, Islet Cell↗
PubMed1989

MRI study of lumbosacral lipoma in children.

The authors report 16 cases of lumbosacral lipoma in children studied by MRI. The exact position of the cord and its relationship to the lipoma were well demonstrated in all cases but one. There was as high incidence (25%) of syringomyelia in the terminal conus. Arnold Chiari malformation was never associated, which differentiates lumbosacral lipomas from myelomeningoceles. However, the nerve roots and their relationship to the lipoma were rarely visualized. Despite these drawbacks, MRI is the examination of choice if lumbosacral lipoma is suspected in children.

Adolescent↗
PubMed1989

MR imaging of the posterior hypophysis in children.

The posterior lobe of the pituitary gland was studied by MR imaging in 30 children without pituitary gland disease and compared with studies from a group of 13 children with central diabetes insipidus, including eight cases of primary diabetes insipidus and five cases of diabetes insipidus secondary to suprasellar tumors (four proved germinomas, one still unknown tumor). Two components in the sella turcica were identified in all 30 children without pituitary gland disease, and the posterior lobe was identified as a high-intensity structure on T1-weighted images. In all 13 patients with diabetes insipidus, the normal hyperintense signal of the posterior hypophysis was absent on T1-weighted images. Three patients with suprasellar tumors presented with a progressively enlarging pituitary stalk on follow-up. Our findings show that absence of the normal hyperintense signal of the posterior lobe is closely related to a loss of function of the neurohypophysis. Size or signal modification of the pituitary stalk should suggest the development of a suprasellar tumor.

Adolescent↗