Biomedical subjects

A Peydro-Olaya

Publications and source records attributed to A Peydro-Olaya.

24 records · Page 2Linked to original sources

PubMed1980

Presence of ganglion cells in Wilm's tumours: a review of the possible neuroepithelial origin of nephroblastoma.

Twenty-seven cases of Wilms' tumour were reviewed in order to confirm the presence of nervous tissue which could imply a 'neuroepithelial' origin for these neoplasms. For this purpose a double-silver impregnation technique was used. Groups of ganglion cells with neurofibrils and non-myelinated axon-like processes appeared associated with a fine neurofibrillar network with neuromuscular junctions. Nervous tissue in nephroblastoma is mature and should not be confused with primary ganglioneuroblastoma of the kidney in which neuroblasts in rosette-like groupings are very numerous. A case report of such a lesion is discussed for purposes of comparison.

Axons↗

PubMed1978

Ultrastructural study of 28 cases of Ewing's sarcoma: typical and atypical forms.

The characteristics of 35 round cell sarcomas of bones are analyzed by optical and electron microscopical means, 28 cases of Ewing's sarcoma and 7 cases of malignant lymphomas (reticulum cell sarcoma) being distinguished. The existence of a morphological diversity within the Ewing's sarcoma group allows the authors to differentiate a conventional form of Ewing's sarcoma (21 cases) consisting of principal blastemic cells and secondary degenerative ones (dark cells) from an atypical variant (7 cases of atypical Ewin's sarcoma) whose structure adopts either an immature mesenchymal or histiocytic appearance. The ultrastructure of the atypical Ewing's cells demonstrates variability in size and in the nucleus, which is grooved and possesses prominent nucleoli. In the cytoplasm, in addition to the existence of a variable amount of glycogen, more highly differentiated structures appear when a comparison is made with the principal cells of the conventional Ewing's sarcoma. There exist filaments and mitochondria complexes, desmosomic-like junctions and profiles of endoplasmic reticulum. No transitional forms between the conventional and the atypical variants of Ewing's sarcoma have been observed. According to this analysis, when compared to other bone malignancies, the presence of glycogen as a means for identifying Ewing's sarcoma seems to be of restricted value. No clinical or anatomical differences could be established between either variant of Ewing's sarcoma.

Adolescent↗

PubMed1975

[Histochemistry and electron microscopy of the embryonal development of the golden hamster kidney: study of the interstitial cells].

The structure and the origin of the interstitial cells in the kidney of the golden Hamster during its embryonic development was studied. For this purpose kidneys from 11, 13, 15 and 17 day-old embryos were used. The histochemical observations as well as the electron microscopy demonstrated that the interstitial cells have a metanephric origin and are embryonically similar to the cellular elements that differentiate the primordial renal vesicles and later organise the epithelial portion of the nephrons. These cells seem to take part in the formation of the basal membranes during tubular genesis.

Acid Phosphatase↗

PubMedDate not supplied

Nasal glioma or nasal glial heterotopia? Morphological, immunohistochemical and ultrastructural study of two cases.

The term nasal glioma has been used to describe a congenital benign tumor of the nasal region containing neural tissue. The nature of these lesions remains open to controversy, because of the different locations of the heterotopic neural tissue involved, the deficient development of the bony structures and the persistence or not of the structural relations with the central nervous system. More recent terms define these lesions as ectopic nervous tissue. A clinical, morphological, ultrastructural and immunohistochemical study is made of two cases of nasal glioma, one associated with agenesis of the corpus callosum. In this case, the mother had been treated with clomiphene. In such cases, morphological and immunohistochemical findings support that "nasal glioma" remain valid as a descriptive term defining a congenital benign tumor composed of heterotopic neural tissue within the nasal region and covered by skin, that may recur following incomplete surgical resection.

Abnormalities, Multiple↗

PubMedDate not supplied

Synovial sarcoma (SS): new perspectives supported by modern technology.

Based upon the experience of 256 cases of synovial sarcoma (SS), the present review analyzes structural, biological and molecular pathology of this poorly known sarcoma. The histology displays a multiphenotype with two major components: biphasic and monophasic SS. In addition, a number of variants have been described: undifferentiated Ewing's like, myoxid and predominantly epithelial (monophasic epithelial sarcoma). Microcalcifications and squamous metaplasia are often seen in the tumor. Immunohistochemistry with EMA and cytokeratin in the epithelial or epithelioid component is diagnostic for SS together with vimentin positivity in the spindle cells. Several other epitopes are also expressed (CD99, CD56, C-MET, HGF/SF, CD44). The ultrastructure confirms the variegated pattern of the neoplasm demonstrating the epithelial component and the epithelioid or spindle cell type closely associated with each other. Transition of epithelial cells to epithelioid and spindle-like mesenchymal component is seen. Nude-mice xenografts and cell lines after in vitro culture confirm heterogeneity of this sarcoma. Molecular histology of the SS has provided high utility not only for their differential diagnosis due to a specific chromosomal translocation: t(X;18)(p11.2;q11.2) but also after cloning these breakpoints resulting in the fusion of two genes: SYT at 18q11 and SSX at Xp11. Further observations have lead to distinguish the existence of two related genes: SSX1 and SSX2, that provide a highly specific and sensitive diagnostic marker for SS. Moreover, clinical correlations have demonstrated that SYT-SSX1 leads to a poor clinical outcome while the fusion SYT-SSX2 provides survival advantages to the patients.

Animals↗

PubMedDate not supplied

[Biopathology of Ewing's sarcoma].

The paper presents the history of Ewing's sarcoma studies; the results of light- and electron microscopy, immunohistochemistry of its variants; criteria of prognosis and differential diagnosis with osteosarcoma, undifferentiated bone sarcoma, malignant ectomesenchymoma, lymphoma, neuroblastoma and rhabdomyosarcoma metastases.

Bone Neoplasms↗