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Biomedical subjects

G Hébert

Publications and source records attributed to G Hébert.

18 recordsLinked to original sources
PubMed1991

Diffuse metastatic involvement of the breast.

Metastases to the breast are not very common and, according to the recent literature, usually present as nodules, most often single but sometimes multiple, generally without retraction or thickening of the skin. The authors reviewed 21 such cases from the last 15 years. In six patients the metastatic infiltration presented as diffuse thickening of the skin and increased density of the breast, as can be seen in inflammatory diseases or after radiotherapy. In five of these six women lymphangitic spread of the carcinoma was demonstrated by microscopy.

Adult↗
PubMed1990

Developmental changes in the half-life of acetylcholine receptors in the myotomal muscle of Xenopus laevis.

1. Tail preparations, containing myotomal muscle and associated spinal cord, were isolated from embryos and tadpoles of Xenopus laevis between stages 25 and 49 (1.15-12 days) and were pulse-labelled with 125I-alpha-bungarotoxin (125I alpha BT) so that the half-life (T1/2) of their acetylcholine receptors (AChRs) could be estimated in organ culture. 2. For the entire population of AChRs, estimates of T1/2 based on a single exponential decline in radioactivity (but see item 4 below) increased from 53-55 h at stages 25-31 (1.15-1.56 days) to approximately 135 h at stage 47 (5.5 days). Beyond stage 47 T1/2 increased only slightly. 3. Radioautographic estimates of the T1/2 of extrajunctional AChRs at stages 47-48 (5.5-7.5 days) were 41-50 h. It follows that the developmental change in the T1/2 of the entire population of AChRs was due to the junctional AChRs. 4. At stages 47-49 (5.5-12 days) the decline in radioactivity for the entire population of AChRs was fitted well by a double exponential. Assuming a T1/2 of 50 h for the extrajunctional AChRs and 210 h for the junctional AChRs, the correlation coefficient (r) was 0.9947 +/- 0.0014 (mean +/- S.E.M.; n = 14) and junctional AChRs were estimated to comprise 80 +/- 3% of the entire population. Similar analysis, as well as experiments in which the degradation of junctional AChRs was assessed by pulse-labelling with fluorescent alpha-bungarotoxin, suggested that at earlier stages of development the junctional AChRs have a shorter T1/2 and comprise a smaller fraction of the entire population. 5. The developmental increase in T1/2 occurred even when animals were raised in the anaesthetic tricaine or in tetrodotoxin, conditions which abolished all motor activity. 6. Developmental increases in T1/2 also occurred in culture but were smaller than those in vivo. The increases in culture did not occur amongst those AChRs which were pre-labelled with 125I alpha BT. 7. It is concluded that in Xenopus myotomal muscle the T1/2 of junctional AChRs begins to increase within a day after the onset of innervation and that the increase does not require nerve or muscle impulse activity. We suggest, among other possibilities, that it may depend upon incorporation of a different molecular species of AChR into the postsynaptic membrane.

Aminobenzoates↗
PubMed1990

Language learning efficiency, dreams and REM sleep.

As a follow-up from a previous study, four subjects taking a 6-week French language immersion program maintained a dream diary starting 2 weeks before until 2 weeks after the course. They also slept in the laboratory during four series of nights: one before the course, two during the course and one after the course. Confirming previous observations, it was observed that those subjects who made significant progress in French learning, experienced French incorporations into dreams earlier and had more verbal communication in their dreams during the language training than those who made little progress. Combining these results with those of the earlier study revealed significant positive correlations between language learning efficiency and both increases in REM sleep percentages, and verbal communication in dreams, as well as a negative correlation with latency to the first French incorporation in dreams. These results support the notion that REM sleep and dreaming are related to waking cognitive processes.

Adult↗
PubMed1988

Thickening of the renal collecting system: a nonspecific finding at US.

The records of 22 patients in whom wall thickening of the renal collecting system was seen at ultrasound (US) were retrospectively reviewed. Wall thickening was found in 15 patients with renal transplants and seven with native kidneys. Severe thickening occurred with transplant rejection, but thickening also occurred with urinary tract infection, reflux, or chronic obstruction in both transplanted and native kidneys. As such, thickening of the renal collecting system seen at US is a nonspecific finding that must be correlated with the clinical and laboratory findings.

Adult↗
PubMed1987

Differentiation of radiation-induced fibrosis from recurrent pulmonary neoplasm by CT.

We describe and compare the computed tomographic (CT) manifestations of radiation fibrosis and recurrent neoplasm and consider the potential application of CT in the follow-up of patients after radiotherapy for bronchogenic carcinoma. Thirty-one patients were evaluated in this retrospective study. The CT findings in 20 patients with radiation fibrosis were compared with those in 11 patients with recurrent tumor. In 19 of the 20 patients with radiation fibrosis, CT allowed demonstration of consolidation, with a straight lateral margin and containing ectatic air-containing bronchi. In 9 of the 11 patients with recurrent tumor, CT showed a soft tissue mass with a convex lateral border and without air-containing bronchi. Twenty of the 31 patients had a suspected recurrence on plain chest radiographs. CT permitted accurate differentiation between radiation fibrosis and recurrent tumor in all patients, with the exception of two who had large pleural effusions. Because of its great specificity, CT appears useful in complementing chest radiographs in the follow-up of patients after radiotherapy.

Carcinoma, Bronchogenic↗
PubMed1985

Computed tomography used to exclude pneumothorax in bullous lung disease.

We report two patients with bullous lung disease and suspected pneumothorax on plain chest radiographs. Chest tubes were inserted in both patients, but no clinical or radiological improvement occurred. Computed tomographic (CT) scans were then performed and showed bullous lesions without any pneumothorax. This permitted the removal of unnecessary chest tubes. In selected patients with severe bullous disease, CT may be useful, either on admission or later, when the diagnosis of pneumothorax by conventional radiographs is doubtful.

Adult↗
PubMed1978

Scanning electron microscope study on flat type membrane oxygenator after prolonged extracorporeal circulation.

Despite adequate anticoagulation, thrombi may develop onto any foreign surface subjected to circulating blood. Although the efficiency of membrane oxygenators can decrease, distal embolization can be more critical and dangerous. Scanning electron microscope observations carried out on the Travenol Modulung oxygenator used both on dogs and on patients for prolonged partial cardiopulmonary by-pass pointed out the following observations. Caution must be observed when translating the results from dogs to human beings. Heparin management can be delicate and critical. The problem of blood transfusion can be extremely important and must be extensively investigated.

Adult↗
PubMed1977

Radiology of breast tumors in the male.

Radiologic investigation of the male breast has given us a better knowledge of its physiopathology. We have reviewed more than 100 cases of breast tumors in male patients. We wish to describe the radiologic presentation of these lesions, the commonest of which is gynecomastia, to distinguish between cancer and gynecomastia, and to compare male breast cancer with female breast cancer. Examination of the breast in man is important. In the adolescent with an enlarged breast, examination may reveal a testicular tumor, whereas in the adult, where a malignant tumor of the breast must excluded, mammography is particularly helpful.

Adolescent↗
PubMed1975

Hepatic echography.

There are 2 kinds of echographic investigations: those which are only complementary and those which are specific by themselves. To improve this latter category, we would like to emphasize two useful echographic signs. First, the attenuation sign, which indicates the fibrotic nature, therefore practically speaking, the cirrhotic nature of a diffuse echogenic pattern. Secondly, the posterior echo accumulation sign, which indicates the liquid nature, and therefore in general the cystic nature of a localized sonolucent pattern.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Warfarin-induced complete bilateral breast necrosis.

Plastic surgeons are routinely consulted about the care of extended cutaneous necrosis. We present an unusual case of complete bilateral breast necrosis and review of the literature of warfarin-induced necrosis to inform plastic surgeons of new advances in the physiopathology of this entity. Warfarin-induced necrosis seems to be produced by an imbalance between circulating clotting factors and blood anticoagulation factors.

Blood Coagulation↗