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Biomedical subjects

F Richard

Publications and source records attributed to F Richard.

At least 199 records · Page 11Linked to original sources

[Lymphography and x-ray computed tomography in the evaluation of lymph node invasiveness in cancer of the bladder. Comparison of their diagnostic value].

The diagnostic value of lymphography and computed tomography (CT) in the assessment of lymph node invasion by bladder cancers has been compared on the basis of 30 observations. Although computed tomography apparently yields better results (reliability: 93%) than lymphography (reliability: 87%), these findings have no statistical significance. The study of literature shows that the statistical exploitation of the results was seldom carried out. The combination of both exploration techniques seems to improve predictive values, but this improvement was not statistically significant in our study.

Adult↗

[Cystine lithiasis and extracorporeal lithotripsy].

ESWL using the HM3 Dornier lithotriptor is a new therapeutic method for cystine stone disease, particularly in patients who have undergone several surgical procedures with or without adjuvant dissolving drugs. We report 3 cases, demonstrating satisfactory fragmentation results. However the rate of stone-free patients was much lower. This situation might be improved by the adjuvant use of dissolving drugs. The preliminary results (Feb 1988) of the European multicenter study (61 cases in 10 centers), confirm our own experience with a 90% fragmentation rate and only 30% stone-free rate for kidney stones and 77% for ureteral stones.

Adult↗

Neutron therapy of soft tissue sarcoma at Louvain-la-Neuve (interim results 1987).

The results of fast neutron therapy of soft tissue sarcoma at the cyclotron of Louvain-la-Neuve are reviewed. 75 patients were analysed, the follow-up ranged from six to 102 months (mean: 30.7 months). 47 patients were treated after radical surgery. A local control rate of 91.5% (43/47) was achieved, and 70% of the patients are alive. 28 patients were irradiated with gross tumour present at the time of neutron therapy (recurrence, incomplete resection, inoperable): a local control was achieved in 5/28 cases (18%), and 68% of the patients are alive. A complication rate of 16% was recorded which was directly related to the treatment volume.

Combined Modality Therapy↗

[Comparative study of MRI and CT x-ray in evaluating the extension of kidney cancer in adults].

The assessment of the extent of kidney cancers with MRI and CT is compared in 40 patients. The appearance of the tumor with MRI is very variable but always heterogeneous. Specific MRI features (tumoral pseudocapsule) provide a higher overall reliability (OR) than with CT for the detection of expansion beyond the capsule and into the kidney: 80% for 60%. Although the overall reliability of MRI is similar to that of CT (92% for 86%), MRI has proved its superiority for the assessment of the limits of endovenous tumoral expansion because of natural flow/thrombus contrast and of the multiple incidences of exploration. There is no significant difference between MRI (OR = 91%) and CT (OR = 88%) or the detection of lymph node involvement. Invasion of neighboring organs is better assessed with multi-incidence MRI. According to Robson's classification, the OR of MRI (77%) is not significantly higher than that of CT (65%). MRI is still a time-consuming and expensive technique, which should be reserved for cases in which iodine is contraindicated and used as a second-intention technique after CT to confirm the invasion of the capsule if partial nephrectomy is indicated, or the better delineate venous or regional invasion which CT could not assess properly.

Adrenal Gland Neoplasms↗

[Nifedipine therapy in uncomplicated essential hypertension and hypertensive problem cases].

In altogether 54 patients with high blood pressure of the clinical degrees of severity I-IV the blood pressure-reducing effectiveness of the calcium antagonist nifedipine was investigated both in the framework of an oral long-term therapy and especially in problematic situations of high blood pressure. According to the results of own treatment nifedipine is particularly suited for the antihypertensive combination therapy with beta-receptor blockers. Monotherapeutically favourable possibilities of application exist in hypokinetic types of the regulation of circulation as well as in elderly hypertensives. Therapy-resistant as well as crisis-like developments of high blood pressure react with excessive, well tolerable and persisting reductions of blood pressure. Above all with regard to this still little considered indication in the meantime nifedipine represents an unavoidable enrichment in the therapeutic basis spectre of the hypertonus.

Adult↗

Modulation of tyrosine hydroxylase gene expression in rat brain and adrenals by exposure to cold.

The long-term changes in tyrosine hydroxylase (TH) activity induced by chronic exposure to cold in brain noradrenergic neurons of the locus coeruleus (LC) were analyzed and compared to those measured in a peripheral tissue such as adrenals. This analysis was made possible at the level of one single tissue corresponding to one animal by the use of sensitive methods that allow assay of TH activity, protein, and mRNA levels in parallel from the same homogenate. The three parameters were measured in brain structures and adrenals of rats maintained at 4 degrees C during 4 days and were compared to those of control animals kept at normal housing temperature (22 degrees C). LC of rats exposed to cold contained 200% more TH mRNA than controls. The amount of TH protein in this area rose to as much as 164% that of controls. Similarly, the activity of the enzyme increased to 140% of the normal value. Thus, these observations show that 1) the increase in TH mRNA was much higher than the increase in protein levels, and that 2) the newly synthesized molecules have about the same activity as that present under normal conditions. In contrast to the LC, no variation of these parameters was observed in the substantia nigra. In the adrenals, the variations in the different parameters were qualitatively similar to that observed in the LC, although they were quantitatively higher: TH mRNA, TH protein, and TH activity levels were respectively 330%, 182%, and 167% that of control adrenals. Altogether, these results demonstrate that exposure to cold induces an alteration in TH synthesis in brain noradrenergic neurons as well as in adrenals.

Adrenal Glands↗

[Results of a 2-year intervention for the modification of atherosclerosis precursors in school children].

801 children aged 10-11 years were examined in 1984, before an allocation in two groups (intervention vs. control). The scope of the intervention was to modify mean values of blood pressure, total cholesterol and smoking through relevant modification of knowledge and behavior. An intermediate assessment, conducted 2 years after the first exam, showed better knowledge regarding cardiovascular diseases and more sport practice in the intervention group, although smoking habits were only slightly modified. Diet, body weight, blood pressure and blood lipid levels did not show any significative differences. The study is now ongoing.

Anthropometry↗

Long-term effects of RU24722 on tyrosine hydroxylase of the rat brain.

The effects of RU24722 (14,15-dihydro-20,21-dinoreburnamine-14-ol) on tyrosine hydroxylase in central catecholaminergic neurons were studied in rats treated with different quantities of the molecule, and a time course was done for the minimal dose that gave the maximal effect. RU24722 induced increases in tyrosine hydroxylase activities and specific protein content in noradrenergic cells of the locus ceruleus and decreased all these parameters in dopaminergic neurons of the substantia nigra and ventral tegmental area. The results pointed out that the specific activity of newly synthesized tyrosine hydroxylase in the loci cerulei was potentially greater but was not expressed "in vivo" except 7 days after injection. The phenotypic specificity and the time course pattern of the action could be considered as a consequence of an induction mechanism. The comparison of long-term change in tyrosine hydroxylase values after piperoxane, RU24722, clonidine, and combined RU24722-clonidine treatment demonstrated that an activation during a few hours did not induce tyrosine hydroxylase in central noradrenergic neurons. Clonidine antagonized the activating effect of RU24722 following its injection but did not affect its long-term induction properties.

Animals↗

Purifications of rat adrenal dopamine-beta-hydroxylase: immunological analysis of its soluble and membrane-bound forms with the use of an antibody raised against the soluble form.

Soluble and membrane-bound dopamine-beta-hydroxylases (sDBH and mDBH, respectively) from rat adrenal glands have been purified through concanavalin A-Sepharose chromatography, gel filtration, and ion-exchange high-performance chromatographies. Both sDBH and mDBH were composed by four subunits of apparent molecular weight of 75,000 and showed a native molecular weight of 300,000. This procedure has not allowed us to obtain a sufficient amount of enzyme to immunize a rabbit. A second, more rapid procedure was designed to isolate sDBH, including concanavalin A-Sepharose chromatography and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A rabbit antiserum was raised against this purified protein. The specificity of the antiserum was demonstrated by neutralization of rat adrenal gland DBH activity, labeling of rat adrenal medulla on histological sections, and, after Western blot, labeling of the 75,000-molecular-weight band in the different fractions associated with DBH activity during purification. The antiserum had a higher affinity for the sDBH denatured by sodium dodecyl sulfate than for the native protein. It had a higher affinity for sDBH than for mDBH. These results strongly suggest the presence of specific hydrophilic epitopes on the sDBH, revealing structural differences between the two hydroxylase forms. Two protein bands were stained on Western blots of crude rat adrenal gland extract. One band had an apparent molecular weight of 75,000, and the other of 82,000. Our results showed that the two proteins contained similar epitopes, an observation suggesting a close structural relationship. The higher-molecular-weight protein could be the 75,000 protein before covalent modifications and cleavage.

Adrenal Glands↗

[Medical conglomerates].

Community hospitals is undergoing rapid consolidation into network of private corporations providing health care services. So, the industrialization of health care lead to mega corporate health care. The multi-nationalization of U.S. multi-health care systems as HCA or Humana, has began at the end of the 70. The impact of this phenomena on the French health care system will be important. In order to protect technological independence and to integrate physicians into medical industrial complex, we have to create european multi-health systems.

Delivery of Health Care↗