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Biomedical subjects

X Marchandise

Publications and source records attributed to X Marchandise.

At least 127 records · Page 7Linked to original sources
PubMed1975

[Atomic absorption spectrophotometry of rubidium levels in several biological media. Technical problems and preliminary results].

The mean of Rubidium rates in human plasma is found in the range of 0,1 mg/l with poor fluctuations; it is significantly less in woman than in man. There is a good linear correlation between rates in plasma and in red cell, rates which are in the same relation than potassium ones. Mean urinary clearance of rubidium is 16 ml/mm but there are large variations.

Blood Viscosity↗
PubMedDate not supplied

Contribution of scintigraphy to verify the reliability of different preparation processes for enteric coated capsules.

The aim of this work was to use radiopharmaceuticals such as technetium (99mTc) and indium (DTPA-Ca111In) to visualize, with a gamma-camera, the disintegration area and time of 3 types of enteric coated hard gelatin capsules (obtained by 3 different preparation processes) and thus, to verify that they are really resistant in gastric fluids and soluble in intestinal zones. Results are well correlated with those previously obtained in vitro (disintegration, dissolution) and in vivo (profiles of plasmatic concentrations versus time).

Acetaminophen↗
PubMedDate not supplied

Validation of a new method for stereotactic localization using MR imaging.

Magnetic resonance is recognized as potentially the best imaging procedure for localization in stereotactic neurosurgery. However, special difficulties necessitate specific adaptation to localize targets in the stereotactic frame. We developed a new method for stereotactic localization. The MR studies were performed using a 0.5 T imager. Four small boxes filled with CuSO4 solution were inserted into the intracranial holders of a Talairach frame. Using fast sequences, thirty 7-mm thick contiguous sagittal slices and twenty 5-mm thick axial slices enabled us to image the entire brain. The image data were transferred for analysis to an image processing station, including special software to handle stereotactic calculations. The accuracy of the origin of the trihedron and systematic geometrical errors were carefully evaluated using a cubic phantom, and corrective algorithms were applied when needed. Moreover, checks have been designed to detect geometrical distortion due to ferromagnetic artifacts, alterations in gradient calibration, or movements made by the patient. This localization method does not necessitate the use of stereotactic frames and appears to be precise enough for clinical use. Duration of MR examination is not a restricting factor, mainly because the patient can be positioned easily.

Calibration↗
PubMedDate not supplied

Intestinal permeability to [51Cr]EDTA in children with Crohn's disease and celiac disease.

[51Cr]EDTA was used as a probe molecule to assess intestinal permeability in 7 healthy control adults, 11 control children, 17 children with Crohn's disease, and 6 children with untreated celiac disease. After subjects fasted overnight, 75 kBq/kg (= 2 microCi/kg) 51Cr-labeled EDTA was given by mouth; 24-h urinary excretion of [51 Cr]EDTA was measured and expressed as a percentage of the total oral dose. Mean and SD were as follows: control adults 1.47 +/- 0.62, control children 1.59 +/- 0.55, and patients with Crohn's disease or celiac disease 5.35 +/- 1.94. The difference between control children and patients was statistically significant (p less than 0.001). These results show that intestinal permeability to [51Cr]EDTA is increased among children with active or inactive Crohn's disease affecting small bowel only or small bowel and colon, and with untreated celiac disease. The [51Cr]EDTA permeability test could facilitate the decision to perform more extensive investigations in children suspected of small bowel disease who have atypical or poor clinical and biological symptomatology.

Administration, Oral↗
PubMedDate not supplied

Fat suppression in MR imaging: techniques and pitfalls.

Fat suppression is commonly used in magnetic resonance (MR) imaging to suppress the signal from adipose tissue or detect adipose tissue. Fat suppression can be achieved with three methods: fat saturation, inversion-recovery imaging, and opposed-phase imaging. Selection of a fat suppression technique should depend on the purpose of the fat suppression (contrast enhancement vs tissue characterization) and the amount of fat in the tissue being studied. Fat saturation is recommended for suppression of signal from large amounts of fat and reliable acquisition of contrast material-enhanced images. The main drawbacks of this technique are sensitivity to magnetic field nonuniformity, misregistration artifacts, and unreliability when used with low-field-strength magnets. Inversion-recovery imaging allows homogeneous and global fat suppression and can be used with low-field-strength magnets. However, this technique is not specific for fat, and the signal intensity of tissue with a long T1 and tissue with a short T1 may be ambiguous. Opposed-phase imaging is a fast and readily available technique. This method is recommended for demonstration of lesions that contain small amounts of fat. The main drawback of opposed-phase imaging is unreliability in the detection of small tumors embedded in fatty tissue.

Adipose Tissue↗
PubMedDate not supplied

Factors influencing bone loss in rheumatoid arthritis: a longitudinal study.

OBJECTIVES: To assess the occurrence of bone loss in rheumatoid arthritis (RA) and to determine the factors influencing bone loss (particularly the usefulness of bone turnover markers) over an 18-month period. METHODS: A total of 51 patients were studied, 6 men and 45 females (of whom 35 were menopausal). Their mean age was 56 +/- 10 years and the mean RA duration was 12 +/- 10 years. Twenty-eight (55%) were receiving corticosteroids (10 mg/day for a mean duration of 6 +/- 5 years). Several clinical and biological parameters reflecting disease activity or severity were recorded both at the 0 and 18-month investigations. Bone turnover was assessed at baseline by measuring the serum levels of 4 biological markers. Three of them reflected bone formation, i.e., procollagen type I C-terminal propepeptide (PICP), procollagen type I N-terminal propeptide (PINP) and osteocalcin (OC). The fourth, procollagen type I-C terminal telopeptide (ICTP), reflected bone resorption. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry both at the lumbar spine (LS) and femoral neck (FN) at baseline and 18 months later. RESULTS: Bone loss occurred both at the LS: 2.1%, [95% CI: 0.8%-3.4%, P < 0.005] and femoral neck: 3.1%, [95% CI: 1.1%-5.1%, P < 0.005]. Bone loss was markedly increased for postmenopausal women at the FN: 5.3% [95% CI: 2.9%-7.6%, P < 0.005]. Bone loss was not statistically significantly different between users and non-users of steroids. Bone loss at the LS was significantly correlated with both osteocalcin (r = 0.51, P < 0.01) and ICTP levels (r = 0.32, P < 0.05). FN bone loss was correlated with the osteocalcin level only (r = 0.34, P < 0.05). Fast losers (bone loss at the LS above the median) had higher OC (P < 0.01) and ESR (P < 0.05) levels at baseline as compared with slow losers (bone loss at the LS below the median). CONCLUSION: Bone loss occurs in RA particularly at the FN and seems to be influenced by increased bone turnover and high levels of inflammation.

Adrenal Cortex Hormones↗