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C Valat

Publications and source records attributed to C Valat.

35 records · Page 2Linked to original sources
PubMed1994

Imaging of pulmonary disease in scleroderma with J001X scintigraphy.

BACKGROUND: J001X is an acylated poly-galactoside isolated from the membrane of Klebsiella and able to interact with macrophages, mainly in their activated state. The aim of the present study was to determine the ability of 99m-labelled technetium (99mTc)-J001X scintigraphy to image pulmonary disease, defined by high resolution computed tomographic scanning and pulmonary function tests, in patients suffering from scleroderma. METHODS: Patients were considered to have pulmonary disease when they had at least two positive signs on high resolution computed tomography, or a decrease in lung volume and single breath carbon monoxide transfer, or both, with no disease process other than scleroderma in their medical history. Positive J001X scintigraphic imaging was defined by symmetrical bilateral pulmonary fixation three and five hours after inhalation of 99mTc-J001X. J001X scintigraphic results were compared with disease activity as indicated by bronchoalveolar lavage (BAL) fluid lymphocytosis. RESULTS: Seventeen patients were studied, in 12 of whom J001X scintigraphy was positive. There was no correlation between BAL lymphocytosis and J001X scintigraphic findings, nor between BAL and pulmonary scleroderma. This was not surprising because of the high specificity of macrophage targeting by J001X. CONCLUSIONS: Follow up of a larger population over a longer period is needed to establish whether there is a prognostic value for positive J001X scintigraphic findings in scleroderma.

Adult↗
PubMed1993

Changes in parathyroid hormone during haemodialysis sessions with two different dialysis membranes: specific adsorption of intact parathyroid hormone.

In patients dialysed with two different membranes (cuprophan and high-flux polysulphone) and using three radioimmunoassays recognizing either intact molecule (iPTH), C terminal (cPTH) or median fragments (mPTH), we compared parathyroid hormone levels at the beginning of and during dialysis. At the beginning of dialysis, cPTH and mPTH levels were always increased but iPTH levels were sometimes within the normal range; during dialysis only iPTH distinctly decreased whichever membrane was used. The behaviour of iPTH cannot be explained by crossing through the membrane because its molecular weight is too high; it cannot be explained by the variation of calcium and phosphate parameters during the session because no correlation exists between the variations in plasma levels of iPTH and the variations in phosphorous and calcium levels. In vitro experimentation with radiolabelled intact iPTH was performed to confirm the specific behaviour of iPTH: these experimental data agree with our in vivo results and suggest an adhesion to the dialysis membrane. Our study shows a specific singular property of iPTH during dialysis and demonstrates the necessity of considering the time of sampling during dialysis and the moiety of parathyroid hormone being measured in patients undergoing dialysis in order to assess osteodystrophy.

Adsorption↗
PubMed1992

Multicentre evaluation of a two-step automated enzyme immunoassay of free thyroxine.

The two-step enzymatic immunoassay of free thyroxine (IMx FT4, Abbott Laboratories, Chicago, IL) was studied in three centres. The assay involved a fluorimetric measurement and took 45 minutes using a completely automated procedure. The results were compared with those from the free thyroxine two-step radioimmunoassay and with the "calculation" of free thyroxine. The analytical precision was found to be excellent if the analyser was correctly set. The IMx FT4 assay seemed unaffected by increased concentrations of albumin and of non-esterified fatty acids (oleic acid) up to 5 mmol/l. The euthyroid reference interval, defined as that including 95% of 194 control subjects, was 12-21 pmol/l. A limited overlap existed between euthyroid and hyperthyroid patients, but a larger one was seen between the euthyroid and hypothyroid population, the latter including subclinical hypothyroidism. IMx FT4 results agreed well when compared with those from two-step radioimmunoassays. The IMx FT4 technique gave rise to a low percentage of elevated results in patients being treated with heparin, but was undisturbed by autoantibodies to thyroxine and triiodothyronine which were present in one hypothyroid patient.

Adolescent↗
PubMed1990

[Phosphorus-calcium metabolism in hyperthyroidism].

Because of the bone remodelling it induces, hyperthyroidism modifies the parameters of calcium-phosphorus metabolism. For a better determination of the mechanism involved, we studied 13 patients with Graves' disease compared with 13 controls. We measured the various parameters of calcium-phosphorus metabolism, notably the levels of parathormone, 25-hydroxycholecalciferol, 1-25 dihydroxycholecalciferol and ostocalcin; 8 patients were re-examined in euthyroidism. Total and corrected values of calcaemia (P less than 0.05 and P less than 0.01), phosphoreamie (P less than 0.01), alkaline phosphatase (P less than 0.01), calciuria (P less than 0.01) and hydroxyprolinuria (P less than 0.01) were significantly higher in patients with hyperthyroidism. Osteocalcin also was significantly increased (P less than 0.01) and correlated with thyroid hormone levels, thus confirming its usefulness as marker of bone remodelling in hyperthyroidism. Creatininaemia was significantly lowered (P less than 0.01). The intestinal absorption of calcium after injection of 1 g of calcium was reduced. Parathormone and 25-hydroxycholecalciferol levels were not significantly different in patients and in controls. In patients who were re-examined in euthyroidism, there was a significant increase in parathormone and in 1-25 dihydroxycholecalciferol levels (P less than 0.05). Thus, in situations of hyperthyroidism 2 elements contribute to a deficit in calcium balance: (a) a fall in parathormone level, consecutive to a rise in calcaemia, induces hypercalciuria; and (b) a fall in 1-25 dihydroxycholecalciferol level, consecutive to functional hypoparathyroidism and hyperphosphoraemia, results in a decrease of intestinal calcium absorption.

Adolescent↗
PubMed1988

[Osteocalcin and anomalies of cellular immunity in rheumatoid polyarthritis].

Spinal and peripheral skeletal demineralisation is sometimes observed in rheumatoid arthritis (RA). Numerous studies have shown the role of osteoclasts in its genesis, but few studies have been conducted to demonstrate a functional anomaly of osteoblasts. Synthesized by osteoblasts, osteocalcin enables to approach the osteoblastic activity, through titration of its serum level. In 31 patients suffering from erosive classical RA, we titrated the serum osteocalcin. In 9 cases, we found a definite decrease of the serum osteocalcin levels. There was a statistically significant difference between these 9 patients and the 21 others, in the presence of anomalies of the CD4/CD8 lymphocytic ratio, the presence of extra-articular manifestations, a high level of rheumatoid factors, class IgM, with an immuno-enzymatic technique. On the contrary, there was no difference regarding the mean duration of the RA course, the mean age, calcemia, and alkaline phosphatases level. Thus, in the course of severe clinical and immunological rheumatoid arthritis, an anomaly of cellular immunity was observed associated with abnormal serum osteocalcin levels. The exact mechanism of this decrease remains to be specified. Other prospective studies are necessary to confirm this preliminary research.

1-Carboxyglutamic Acid↗
PubMed1986

Radionuclide study of bronchial aspiration in intensive care newborn children.

Newborn children, fitted with tracheal prosthesis for mechanical ventilation, may present chronic pulmonary complications due to the repetition of silent aspirations following gastroesophageal reflux. We evaluated, in a newborn intensive care population, the frequency of such aspirations and the relationship between the different parameters and pathologies. This particular group of sick neonates cannot be moved, and as the hospital for the newborn is far from the Nuclear Medicine district, the patients cannot be scanned. We used a simple technique: the injection of a solution of 99Tcm-sulphur colloid in their gastric tube, and the measurement of the tracheal aspiration tubes' radioactivity. Thirty one children were tested; thirteen children (42%) had radioactive tracheal tubes. The study of the relationship between several parameters and our results, shows that the examination was generally positive when the maximal insufflation pressure value was low. Our results prove that silent aspirations are very frequent in such a population and that it will be perhaps useful to prevent them in a systematic way in order to save the neonates from developing pulmonary lesions.

Female↗
PubMed1984

Meta-iodobenzylguanidine adrenal medulla localization: autoradiographic and pharmacologic studies.

In order to investigate the mechanism of uptake of meta-iodobenzylguanidine (mIBG) by the adrenal glands, autoradiographic and pharmacologic studies were performed in mice and dogs receiving radioiodinated mIBG. In mice, on macroautoradiography of whole body sections 48 h after 125I-mIBG, most of the radioactivity was focused in the adrenal glands. On microautoradiography, silver grains were exclusively located in the adrenal medulla. Tissue counting after phenoxybenzamine, cocaine, and desipramine treatment resulted in 45%, 35%, and 0% inhibition of mIBG uptake, respectively. Tissue counting and scintigraphic studies demonstrated a more than 50% mIBG release from the adrenal glands after reserpine. These data indicate the high affinity of mIBG for adrenal medulla and suggest that the mIBG and catecholamine uptake mechanisms are only partially the same.

3-Iodobenzylguanidine↗
PubMed1984

Correlation of plasma hormone levels and peripheral circulating lymphocyte subpopulations during human pregnancy.

Using monoclonal antibodies (OKT3, OKT4, OKT8) peripheral blood lymphocyte subsets were determined in 40 normal primiparous pregnant women and compared with those of 31 nonpregnant controls. In pregnant women plasma concentrations of estradiol, progesterone, human placental lactogen (HPL), beta subunit of human chorionic gonadotropin (beta HCG), and alpha-fetoprotein were measured by means of radioimmunoassay. We studied if correlations between peripheral lymphocyte subsets and plasma hormone levels might exist. We observed in pregnant women from 10 to 40 wk of amenorrhea a decrease in the percentage of OKT3 and OKT8 cells, and during the course of pregnancy an increase in the percentage of OKT4 cells. This increase inversely correlated with plasma beta HCG levels and directly correlated with plasma HPL levels.

Adult↗
PubMed1984

[Hypocaloric and high-protein diet in obese patients: changes in the lean mass].

We have followed for 40 days seven hospitalized, young (age, mean SD : 33 +/- 8 yrs), and moderately obese (W/H : 35 +/- 3.92) women. During the first 5 days (DO to D5) they received a diet similar to their customary home-diet; from D6 to D40, their daily caloric intake was adjusted to 3,41 +/- 0.13 MJ (816 +/- 30 kcal). This diet comprised 21 p. 100 of sugars, 35 p. 100 of lipids, 1.57 +/- 0.09 g proteins per kg ideal body weight. Five seven-day periods have been studied. On the first day of each period, we recorded body weight and measured plasma albumin, pre albumin, retinol binding protein, complement (CH50 and C3) C peptide (in the fasting state and after glucagon stimulation), and thyroid hormones (T3 and rT3). On each of the 35 days of this study, total nitrogen was measured (Kjeldahl's method) in food, urine and faeces. On D0 and D41 lean and fat body masses were evaluated through measurements of total water (dilution of tritiated water) and of skin fold thickness respectively. From D0 to D40, the average weight loss was 8.76 +/- 1.86 kg; the cumulated nitrogen balances were negative in 6 patients and positive in one, with variations from one period to another and from one patient to another. Plasma proteins and hormones did not vary significantly. Changes in lean mass were comprised between + 0,7 and -- 1,6 kg in spite of the fact that all patients received the same caloric and protein intake.

Adolescent↗
PubMed1983

[Dexamethasone suppression in the depressed patient. Reflections apropos of an experience].

This work, based on the dexamethasone suppression test (DST) for 28 patients classified according to the Research Diagnostic Criteria (RDC), tries, by examining the literature, to point out the acquired knowledge through this new biological psychiatric instrument. The results confirm those of previous works. The discussion is directed towards a better delimitation between the different categories of primary affective disorder and the possible extensions of DST to other fields not yet enough studied.

Adjustment Disorders↗