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Biomedical subjects

X Marchandise

Publications and source records attributed to X Marchandise.

At least 73 records · Page 4Linked to original sources

Iodine-123-labelled serum amyloid P component scintigraphy in amyloidosis.

This study describes the results of scintigraphy with iodine-123-labelled serum amyloid P component (SAP) as a means of establishing the distribution of organ involvement in amyloidosis. The significance of 123I-SAP scans obtained in 15 patients with biopsy-proven AA or AL amyloidosis is discussed. Biopsy-proven amyloidosis was typically confirmed by scintigraphy, though such confirmation was not obtained in the kidneys in six patients with histological proof of extensive renal amyloid deposition. This lack of uptake may have been due to the accumulation of a major part of the 123I-SAP in the spleen and/or liver. Twenty-four hour whole-body retention of 123I-SAP was higher in patients with amyloidosis than in controls. Twenty-four hour tracer accumulation of the radioactivity in the extravascular compartment was notably greater in patients than in controls and appeared to be a good diagnostic criterion. We conclude that 123I-SAP scintigraphy may be helpful for the evaluation of organ involvement not only in patients with biopsy-proven amyloidosis but also when a biopsy cannot be performed or when a strong suspicion of amyloidosis exists in spite of repeated negative biopsies.

Amyloidosis↗

Bone mineral and fat measurement with a novel dual photon absorptiometer.

The authors have produced an original dual-photon absorptiometer, with specific algorithms, permitting real-time automatic bone recognition, to reduce examination time (to 5 min). It permits the simultaneous measurement of the mineral density of an area of bone (BMD), the fat percentage of the soft tissues (PFST) that surround it, and the variation in this percentage. It visually represents, on one and the same picture, freely defined in terms of dimension and definition, bone mineral distribution and fat mass distribution. The performances are analysed, using phantoms and taking ten control subjects, in the region of the femoral neck. The variations in PFST in the control subjects are compared with the measurements carried out in MRI in the same region. In all these control subjects, there is a regular decrease in PFST in this region along an upper external/lower internal axis. This decrease has been likened to a regression line, the slope of which, representing between -0.16 per cent of fat per cm and -1.7 per cent per cm, has a mean value of -0.81 per cent per cm. The BMD is thus reduced by 0-2.5 per cent, depending on the subjects.

Absorptiometry, Photon↗

Frameless method of stereotaxic localization with DSA.

PURPOSE: To improve a method of stereotaxic localization with digital subtraction angiography that does not require use of a localization frame fixed to the patient's skull during examination. MATERIALS AND METHODS: An independent, low-cost, stereotaxic computing system was devised. Software programs used magnetic resonance images, computed tomographic scans, and digitized radiographs of plastic bone implants with head landmarks to establish reference trihedrons in each imaging system, transpose target coordinates from one system to another, adjust surgical instruments, help plan radiation surgery, and compute and display isodose curves. RESULTS: The geometric distortions of the image intensifier were corrected. Distortion problems of the conic projection were solved, and three-dimensional localization was achieved with only two associated front and lateral views. Accuracy to within 1 mm was achieved for the three coordinates. CONCLUSION: This frameless stereotaxic localization technique is highly accurate and reliable. The system allows maximum automation of examination procedures.

Angiography, Digital Subtraction↗

Accessory spleen in recurrent chronic immune thrombocytopenic purpura.

From 1969 to 1985 we discovered accessory spleens in 8 patients with chronic immune thrombocytopenic purpura (ITP) who relapsed or failed after splenectomy. Imaging of accessory spleen used a liver spleen scintigraphy with heat-treated RBC labeled with Tc-99m. Platelet kinetic studies with 51Cr or 111In, including sequestration index, were performed. Five patients had accessory splenectomy. Disappearance of bleeding symptoms was achieved in the 5 splenectomized patients but with only partial response of platelet counts. These results are discussed in the context of diagnosis and therapeutic management of accessory spleens in patients with chronic immune thrombocytopenic purpura who relapsed or failed after splenectomy.

Adolescent↗

Solid-state 31P NMR spectroscopy of bone and bone substitutes.

Using magic angle sample spinning 31P NMR spectroscopy, we studied NMR parameters of hydroxyapatite, calcium-deficient hydroxyapatite, and beta-tricalcium phosphate. These data were compared to rabbit bone parameters. Rabbit bone spectrum is similar to deficient hydroxyapatite spectrum but high-power proton decoupling did not modify its linewidth. Moreover, both bone T1 and deficient hydroxyapatite T1 were much longer than pure hydroxyapatite T1 and beta-tricalcium phosphate T1. We used these results to develop quantitative analysis of newly deposited bone inside beta-tricalcium phosphate implants in rabbit. This method made it possible to demonstrate the effect of porosity on osteoinduction of biomaterials.

Animals↗

Use of pertechnetate 99mTc for abdominal scanning in localising an ileal duplication cyst: case report and review of the literature.

A 10-year-old boy presented with periumbilical postprandial pain and some melena. Physical examination was normal. All investigations were negative except a pertechnetate 99mTc abdominal scan which showed a very large and horn-shaped focus of high activity in the right flank. An ileal duplication was resected. It was lined by antral gastric mucosa with a large ulcer. The patient was treated successfully. The abdominal pertechnetate scan is discussed.

Child↗

Increased pulmonary and intestinal permeability in Crohn's disease.

We tested the hypothesis that an increased epithelial permeability may affect sites other than the intestine in patients with Crohn's disease by simultaneously evaluating their pulmonary and intestinal permeability. Pulmonary and intestinal permeability were measured by clearance of inhaled technetium-99m diethylene triamine pentacetate (99mTc-DTPA) and by urinary recovery of chromium-51 ethylene diamine tetracetate respectively in 22 patients with Crohn's disease. The half time clearance of 99mTc-DTPA from lung to blood (t1/2LB) was decreased--that is pulmonary permeability increased--in the whole group of patients with Crohn's disease as compared with 13 controls (median 45.5 minutes (8-160) v 85 minutes (34-130) (p less than 0.003)). When analysed separately only patients with active Crohn's disease (n = 15) had a decreased t1/2 lung to blood v controls (42 minutes (8-160) v 85 minutes (34-130) (p less than 0.0025)). Among patients with active Crohn's disease, six were studied again when their disease was quiescent and their t1/2 lung to blood did not differ significantly. The intestinal permeability was increased in the whole group of Crohn's disease patients as compared with 15 controls (5.25% (1.2-24) v 1.7% (0.65-5.75) (p less than 0.0002)). When analysed separately both patients with active and inactive Crohn's disease had increased intestinal permeability v controls (8.1% (1.6-24) and 3.5% (1.2.9.2) v 1.7% (0.65-5.75)) (p less than 0.0001, p = 0.05 respectively). Six patients with active Crohn's disease were studied again when their disease was quiescent and their intestinal permeability decreased significantly p less than 0.04). Pulmonary permeability was increased in patients with Crohn's disease but was not greatly influenced by Crohn's disease activity as opposed to intestinal permeability. The mechanism of this increase is unknown, but may be related in some patients to the presence of an alveolitis.

Adolescent↗

Increased intestinal permeability in active pulmonary sarcoidosis.

Altered permeability of the gut is a well-described feature in Crohn's disease. Because of pathologic similarities between Crohn's disease and sarcoidosis, we initiated this study to evaluate the permeability of the gut mucosal lining in patients with pulmonary sarcoidosis. A group of 18 patients with biopsy-proven pulmonary sarcoidosis (active n = 8, inactive n = 10) were included in the study. Control groups included 22 patients with Crohn's disease (active n = 12, inactive n = 10), nine untreated patients with recent pulmonary tuberculosis, six patients with coal worker's pneumoconiosis (CWP), eight patients with idiopathic pulmonary fibrosis (IPF), and 16 healthy subjects. All were nonsmokers. The 24-h urinary excretion of 100 microCi 51Cr-ethylenediaminetetraacetic acid (51Cr-EDTA) was used to test the intestinal permeability (IP). As previously demonstrated, patients with active Crohn's disease demonstrated a dramatic increase in IP (7.7 +/- 1.4%) that was clearly reduced in inactive CD (2.34 +/- 0.54%). Patients with active pulmonary sarcoidosis exhibited a marked increased IP to 51Cr-EDTA (4 +/- 0.54%), which was not found in patients with inactive sarcoidosis (1.6 +/- 0.17%). IP was normal in patients with pulmonary tuberculosis (1.03 +/- 0.25%), CWP (2.1 +/- 0.54%), and IPF (1.9 +/- 0.33%) and did not differ from the control group (1.76 +/- 0.23%). In addition, in 6 patients with active pulmonary sarcoidosis, the concentrations of albumin and hyaluronan were measured in jejunal perfusion fluid and compared with those obtained from 10 patients with active Crohn's disease and 16 control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗

[The exact costs of studies in a hospital nuclear medicine department].

Objective data about the costs of nuclear medicine examinations are scarce and rather conflicting. Authors describe a method quantitating the costs of nuclear medicine investigations. These calculations were applied to a medium-sized nuclear medicine center set up in a teaching hospital. Calculations were as a tarification and followed the rules of monographic studies. They rely on exhaustive evaluation of each expense and precise analysis of their repartition. Average cost of the examination was 1,016 FF but the study reveals that costs varied from 664 to 6,746 FF. It appears that, but the more common investigations, exact costs are poorly related with nomenclature codification and that radiopharmaceutical costs have to be separately dealt with. This method allows to simulate costs-effects of any structure modification before being applied. One of the major feature of such a study is that it depicts a given center at a given time. Although it is to be hoped that the method should be spread, it should be hazardous to generalize its results.

Cost-Benefit Analysis↗

Imaging of systemic Candida albicans infections with a radioiodinated monoclonal antibody: experimental study in the guinea pig.

Guinea pigs intravenously infected with Candida albicans were scanned to evaluate the use of radioiodinated monoclonal antibodies (MAb) to fungal antigens for detecting tissue infection sites. A total of 18 infected and 8 uninfected animals were used. MAb and F(ab')2 fragments directed against cell wall glycoproteins of C. albicans were labeled with 131I. Another MAb directed against a Schistosoma mansoni glycoprotein was labeled with 125I and used as a nonspecific control. Radiolabeled MAbs were injected at a dose of 12.5 micrograms (500 kBq) per animal. Images were acquired 24 h later. Animals were then killed and the dissected organs were separately gamma-counted. The number of C. albicans colony forming units (cfu) per gram was determined in each organ. A clear relationship was found between the anatomic distributions of C. albicans and 131I. The biodistribution of 131I radioactivity associated with anti-Candida MAb was greater in infected animals than in healthy animals and increased with the number of cfu per g in each organ. The distribution was highly specific in animals with Candida endophthalmitis, a pathognomic feature of organ involvement during hematogenous dissemination. In contrast, the distribution of 125I radioactivity associated with the nonspecific MAb was similar in healthy and infected animals. In infected animals, it was totally independent of the intensity of fungal infection.

Animals↗

[Effects on the bone metabolism of long-term treatment with antivitamins K1].

Oral anticoagulants (OC) prevent the activation by carboxylation of coagulation proteins. However this action also affects osteocalcin, or bone Gla-protein, a parameter of bone remodelling. Phosphorus and calcium metabolism, osteocalcin levels and bone mineral content were studied in twelve men aged under 60, and who had been taking OC for more than a year, in comparison with a paired group of nine controls with the same cardiovascular pathology but not taking anticoagulants. Osteocalcin levels were lower in the OC group (3.44 ng/ml) than in the control group (5.88 ng/ml) (p = 0.01). There was no significant difference in other phosphorus/calcium balance parameters nor in bone density between the two groups. No evidence was found of any osteopathy in the OC group, but the decrease in serum osteocalcin could result either from inhibition of its secretion or of its carboxylation, or from an action on the osteoblast.

Anticoagulants↗

[Cerebral magnetic resonance imaging in the neonatal period. Initial results].

The place of neonatal cerebral MRI and its specific contribution compared with conventional imaging techniques were evaluated in 36 patients. The difficulties specific to the patient population studied met during this preliminary period are described, with their local solutions. A preliminary evaluation of the diagnostic and prognostic value of MRI according to the disease state and gestational age is presented. The specific contribution of MRI compared with transfontanellar ultrasonography and CT scan is discussed.

Anesthesia↗

A new, fully versatile surface coil for MRI.

To enable surface coils to be adapted to a wide variety of examinations and anatomical features, the authors present a flexible detector coupled with an auto tuning device. The conductive loop, which is a flexible mercury filled tube, can be used to obtain various shapes, such as a single flat 22-cm diameter loop or an 11-cm diameter two-turn coil. Tuning is carried out at 21 MHz (0.5 T field) by a microprocessor controlled varactor. Studies conducted on a phantom are used to evaluate the signal/noise ratio and the spatial sensitivity of the coil according to different geometrical arrangements (saddle-shaped and two-turn). The results are compared with those obtained with the constructor's spine coil. The studies of patients described show good image resolution, even in the case of short sequences with thin slices and restricted fields of view. The clinical results and those obtained on the phantom demonstrate the feasibility and value of the device, particularly in examining anatomical regions of different forms.

Humans↗