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Biomedical subjects

A Mazabraud

Publications and source records attributed to A Mazabraud.

At least 91 records · Page 5Linked to original sources
PubMed1977

[Tumors and pseudo-tumoral dysplasias of orbital bones].

The authors review and study, especially from the anatomo-pathological aspect, the different tumours and pseudo-tumoural dysplasias of the orbital bones taken from the collection of the Laboratory of Ocular Pathological Anatomy of the Hotel-Dieu in Paris. They demonstrate the particular frequency of osteomas and fibrous dysplasias and discuss the orbital predisposition of giant cell tumours of bone. Finally they underline the existence of vascular bone tumours and aneurysmal cysts.

Aged↗
PubMed1977

[Electronic microscopic study of a sacral chordoma. Characterization of various development stages of the tumor cells].

The electron microscopic study of a sacral chordoma, the cells of which contain variable amounts of glycogen, allowed to characterize different stages in the evolution of the tumoral cells. The young cells contain almost no glycogen ; progressively it becomes more abundant and fills up almost the whole cytoplasm. At the end of the evolution glycogen disappears while the cell becomes vacuolated. This suggests that enzymatic lysis of this polysaccharide could be the cause of the vacuolation which finally produces the physaliferous cell. Comparison between the cells of the chordoma and those of the normal notochord shows some morphological similarities in the development of these cells. These different data may be useful for a classification of the various types of chordomas.

Adult↗
PubMed1977

[Demonstration of osteoclastic acid phosphatase in the serum of patients with giant cell tumors. Preliminary study].

Starting from the fact that an ultrastructural cytochemical study of the Giant-Cell Tumour demonstrated the presence of a large amount of lysosomic acid phosphatase in the tumour cells, an attempt was made to evidence the presence of this enzyme in the serum of patients bearing such a type of bone tumor. Acrylamide gel electrophoresis of the serum allowed one to separate a number of isoenzyme with acid phosphatase activity and to characterize at least two bands different from those secreted by prostate, blood platelets, liver or spleen. The comparison between zymograms of normal and pathological sera, more particularly in Paget disease, led to consider that these two bands had an osteoclastic origin. Besides, these bands vanish after tumor eradication. Acrylamide gel electrophoresis of serum provides therefore a means to support the preoperative diagnosis of Giant-Cell Tumor and, eventually, to detect an early recurrence of the disease.

Acid Phosphatase↗
PubMed1975

Biochemical research on oogenesis. Nucleotide sequence of initiator tRNA from oocytes and from somatic cells of Xenopus laevis.

The nucleotide sequence of initiator tRNA, tRNAfMet, from vitellogenic oocytes of Xenopus laevis was determined. The sequence was deduced from analysis of all T1 and pancreatic oligonucleotides and comparison with the sequence of initiator tRNA from other animal species. At least 80% of all initiator tRNA molecules from oocytes have the same nucleotide sequence. This means that most and probably all initiator tRNA genes which are active in oocytes are identical to one another. No structural difference was observed between liver and oocyte initiator tRNAs. Initiator tRNA from X. laevis has the same nucleotide sequence as initiator tRNA from several species of mammals. The genes coding for this RNA have therefore remained unchanged in the mammalian and amphibian lines for at least 300000000 years.

Animals↗
PubMed1975

Biochemical research on oogenesis. Comparison between transfer RNAs from somatic cells and from oocytes in Xenopus laevis.

The properties of tRNA from oocytes of Xenopus laevis were compared with those of tRNA from somatic cells of the same species. Both types of tRNAs were found to have the same average length and to contain an equal variety of modified nucleotides. However, tRNA from small oocytes differed from somatic tRNA by its chromatographic behavior on methylated-albumin kieselguhr columns. The elution profiles from reversed-phase chromatography 5 columns of several aminoacyl tRNAs were compared after charging somatic and oocyte tRNSs with 3H or 14C-labelled amino acids. Striking differences in peak position were observed when tRNA from small oocytes was mixed and co-chromatographed with somatic tRNA. The differences were less important when tRNAs from large oocytes and from somatic cells were compared. Mixtures of egg and somatic tRNAs gave completely or almost completely coincident elution profiles. Only one isoacceptor, tNRA1Met (initiator tRNA) had the same position in all reversed-phase chromatography 5 chromatograms. The results are discussed in terms of possible post-transcriptional modifications of tRNA in the course of oogenesis. An alternative explanation resorting to changes in the tRNA population of the growing oocyte is also envisaged.

Animals↗
PubMed1975

[Remote prognosis in esthesioneuromas (apropos of 11 cases)].

Research was carried out into a group of 11 patients with tumours of the olfactory placode or aesthesioneuromas observed and treated by the authors (10 of them unpublished cases). The authors recall the histological characteristics which, theoretically, distinguish aesthesioneuroepithelioma from aesthesioneurocytoma and aesthesioneuroblastoma and the risk of mistaken interpretation due to confusion with other types of tumour. The following conclusions emerged from this research : 1) Aesthesioneuroma is indisputably a radiosensitive tumour as has been proved by the long-term cures obtained either by irradiation alone or by irradiation after incomplete surgery. 2) However it is exceptional for diagnosis to be made merely by intranasal biopsy. In all doubtful cases, surgical investigation is necessary. This requires a broad para-latero nasal approach route which is the only one affording accurate anatomical localisation of the lesions and complete ablation of the tumour including, where necessary, removal of the lamina cribrosa.

Adolescent↗