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Biomedical subjects

A Brabant

Publications and source records attributed to A Brabant.

13 recordsLinked to original sources
PubMed1989

The role of glucocorticoids in the regulation of thyrotropin.

The potentially inhibitory action of endogenous or exogenous synthetic glucocorticoids on TSH secretion was investigated. Pulsatile and circadian TSH and cortisol rhythms were measured in healthy subjects (12 rhythms), but no correlation between the hormones could be detected. Acute stimulation of endogenous cortisol secretion by CRH tests (1 microgram/kg of ovine CRH) at 20.00 h in 9 healthy volunteers did not significantly alter the nightly increase in TSH. Chronic elevation of endogenous cortisol serum levels in patients with Cushing's disease revealed a heterogeneous pattern. In 2 patients serum TSH and thyroid hormone levels showed a normal 24-h rhythm, whereas the other 2 patients had low TSH serum levels. Acute treatment of 9 healthy volunteers with 0.5, 1 or 2 mg dexamethasone po at 23.00 h resulted in a significant dose-dependent suppression of mean basal TSH levels 9h later. Treatment with 30 mg of prednisone for 1 week in 7 patients with Crohn's disease did not influence basal TSH. The TSH response to TRH was only temporarily suppressed on day 3, but not on day 7 of treatment. The results suggest than under physiological conditions glucocorticoids have no regulatory influence on pulsatile and circadian TSH secretion.

Adult↗
PubMed1989

[Esthetic IMZ implant for a central incisor].

Replacement of a missing incisor with an osseo-integrated implant, presents a difficult prosthetic problem for the practitioner because of the obliqueness of the implant and its diameter smaller than the tooth to be reconstructed. Therefore, a topographic and aesthetic pre-estimation is highly desirable. The patient whose treatment is described hereafter, presents large diastemas permitting to set the missing tooth in several locations. The various options are simulated on a study model and recorded by a silicone or resin index. This index is cut out so that the implant site is clearly defined and it presents a guide rod indicating the direction of the alveolar bone. The optimal site is selected during the surgical procedure with the most favorable index depending on the residual bone. After the implant is released, the location impression, is taken using asymmetric transfer allowing a strict positioning of the implant's replica and its thread. In order to prevent the making of a triangular-shaped crown, a false transfixed core removable is built over the intramobile component of the IMZ as well as pa periodontal ring. The latter is independent and maintained by the intramobile component. It compensates the difference in diameter between the implant and the natural tooth to be reconstructed. Its finely polished but asymmetric internal aspect prevents the rotation of the device. The volume of this device is controlled by a silicone index made on the preestimation model. Both pieces are cast in gold and assembled on the implant with a positioning indes. Parallel proximal grooves increase the friction of the core and a ceramo-metal crown is built in the conventional fashion. It is temporally cemented, and periodically removed and cleansed. The absence of gingical sulcus provides an aesthetic result similar to a bridge component.

Dental Implantation, Endosseous↗
PubMed1987

Circadian and pulsatile thyrotropin secretion in euthyroid man under the influence of thyroid hormone and glucocorticoid administration.

The inhibitory action of thyroid hormones (TH) and glucocorticoids on circadian and pulsatile TSH secretion was investigated in groups of five normal men by sampling blood every 10 min for 24 h (start, 1750 h). Serum TSH was measured by a sensitive immunoradiometric assay. Continuous infusion of 50 micrograms T3 or 250 micrograms T4 for 8 h (1900-0300 h) significantly suppressed serum TSH levels (T3, P less than 0.025; T4, P less than 0.05; by paired t test). Administration of 3 g sodium ipodate 7 h before TH infusion did not alter the TSH response to T3, but T4-dependent suppression was abolished. Pulsatile TSH secretion [basally, 5.8 +/- 1.3 (+/- SD) pulses/24 h, as analyzed by the PULSAR program; 6.8 +/- 1.9 by the Cluster program] was not significantly altered by any of the experimental conditions. The additional finding of blunting of the TSH response to TRH after TH alone or ipodate and T3 suggests a predominantly pituitary feedback action of TH exerted via conversion of T4 to T3. In contrast, bolus injections of 4 mg dexamethasone (dex) at 1900 and 2200 h abolished TSH pulses for at least 6 h (PULSAR, 6.6 +/- 1.6 pulses/24 h basally vs. 3.6 +/- 3.0 under dex; Cluster, 7.0 +/- 2.7 pulses/24 h basally vs. 1.6 +/- 1.6 under dex). Dex administration also resulted in a prompt, sustained, and significant suppression of basal TSH (P less than 0.0005). Together with a normal serum TSH response to TRH (in separate experiments 1, 9, and 19 h after dex administration), these data suggest that glucocorticoid feedback occurs at a suprapituitary level.

Adult↗
PubMed1975

[Treatment of fractures of the humerus by intramedullary fixation].

The Hackethal's technique of intramedullaring wiring for humeral fracture represents the immobilisation procedure particularly convenient for this bone. This procedure can be realised without special instrumentation with Kirschner's wires and image intensifior. To allow the approach of the fracture, the patient's position is choosed upon the topography of the lesion. The intramedullaring wiring is always done from down to up. Indications for this procedure are: humeral shaft fracture, humeral neck fracture, and fractures of the shaft and of the neck. During the reduction of the fracture, the immoderate use of a image intensifior seams to be the major risk. Hackethal's technique for medullary wiring was used in 21 patients, only one pseudarthrosis was noted. The fonctionnal recovery of the arm is usually realised in three months.

Adolescent↗