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R Noguera

Publications and source records attributed to R Noguera.

At least 37 records · Page 2Linked to original sources
PubMed1993

dbl oncogene expression in childhood tumors and tumor cell lines.

We studied the expression of the dbl oncogene in the total RNA obtained from a wide spectrum of childhood tumors, including Ewing's sarcomas, peripheral neuroectodermal tumors (PNET), esthesioneuroblastomas, neuroblastomas, retinoblastomas, rhabdomyosarcomas, osteosarcomas, and synovial sarcomas. Material was obtained from primary tumors, nude mice xenografts, and tumor cell lines. Following the Northern blot technique, a single band of 2.8 kb was found in each analyzed case. Induction of neural differentiation in Ewing's sarcoma, peripheral PNET, and neuroblastoma cell lines with dibutyryl cyclic AMP did not change the expression of the dbl oncogene. We conclude that the wide expression of the dbl oncogene in these childhood tumors reduces its value as a molecular marker for their differential diagnosis; on the other hand, the dbl oncogene does not appear to be an essential molecular factor in the process of neuroectodermal differentiation of small round cell tumors of childhood.

Animals↗
PubMed1992

Dynamic model of differentiation in Ewing's sarcoma cells. Comparative analysis of morphologic, immunocytochemical, and oncogene expression parameters.

We report the establishment of a model of neural differentiation in four well-characterized Ewing's sarcoma cell lines. This process was induced by serum-depleted medium (1% fetal bovine serum) and agents such as dibutyryl cyclic AMP and retinoic acid. The morphologic changes were characterized predominantly by the presence of neurite-like elongated processes showing varicosities and branching along their course with numerous internal filaments and electron-dense granules. Immunocytochemically, differentiation was accompanied by a considerable increase in reactivity for neural markers of several types: neuroblastic, neuroepithelial, neuroendocrine, Schwannian and even glial. In contrast, the tumor promoter, phorbol 12-myristate 13-acetate inhibited differentiation. Several morphologic changes were observed in phorbol 12-myristate 13-acetate-treated cells: the cells became smaller and rounder, were poorly adherent to substrate, by electron microscopy lacked cytoplasmic organelles, electron-dense granules or neural processes, and showed decreased expression of neural markers. Northern blot analysis was performed to establish whether there was any relationship between neural differentiation and degree of N-myc, c-myc and dbl oncogene expression. There was no N-myc oncogene expression in the mRNA of Ewing's sarcoma cells, even after neural induced differentiation. The degree of c-myc and dbl oncogene expression appeared heterogeneous, and varied with the culture condition. Based on these results, it may be inferred that Ewing's sarcoma cells in vitro display a variable neural phenotype, there being a variety of biologic responses to diverse culture media and various differentiation agents, but with no consistent effect on N-myc, c-myc and dbl oncogene expression.

Bucladesine↗
PubMed1991

Fluoxetine vs. clomipramine in depressed patients: a controlled multicentre trial.

A sample of 120 patients, all of whom met DSM-III criteria for major unipolar depressive disorder, were randomly allocated to two treatment groups. Sixty patients were treated with fluoxetine and 60 with clomipramine during a 6-week period. No significant difference was found in antidepressant efficacy, with improvement occurring on both drugs. Important differences were found in the side-effects profile of each group, their incidence being significantly lower and tending to disappear during the course of treatment in the group of patients treated with fluoxetine.

Adult↗
PubMed1990

Soft tissue Ewing's sarcoma. Characterization in established cultures and xenografts with evidence of a neuroectodermic phenotype.

This study characterizes the histogenesis of soft tissue Ewing's sarcoma (StEs) based upon an analysis of three tumors. Long-term cultured cell lines and nude mice xenografts were established from original neoplasms or from their metastases. Histologically they revealed a small round cell pattern without signs of differentiation. Several ultrastructural features of neural type were found; the same were also seen on culture cell lines. Moreover, immunohistochemical study for neural markers revealed the presence of HNK-1, NSE, LIRC-LON 36, S-100 protein, glial fibrillary acidic protein, neurofilaments (70 kilodaltons), and chromogranin; some of these markers were present only in the transplants. Cytokeratin was also seen. The translocation t(11;22)(q24;q12) was found in all three neoplasms together with other chromosomal abnormalities. N-myc RNA gave negative results whereas c-myc RNA was expressed. Therefore it may be postulated that StEs displays neuroectodermal features somewhat similar to those seen in peripheral neuroepithelioma as well as in atypical Ewing's sarcoma of bone.

Adolescent↗
PubMed1989

Giant-cell tumor of bone, stage II, displaying translocation t(12;19)(q13;q13).

A new case of giant-cell tumour (GCT) of bone with benign histological features, clinical stage II, has been reviewed with immunohistochemistry and electron microscopy. After short-term tissue culture the karyotype, using G-banding techniques, presented a consistent translocation t(12;19)(q13;q13). Nude mice xenografts of the tumour were unsuccessful after 6 months of follow-up. Presence of such chromosomal rearrangement may be related to locally aggressive, histologically benign giant-cell tumors of bone.

Adult↗
PubMed1989

Pigmented esthesioneuroblastoma showing dual differentiation following transplantation in nude mice. An immunohistochemical, electron microscopical, and cytogenetic analysis.

Esthesioneuroblastoma (ESTH) is a neuroepithelial-cell-derived neoplasm of the olfactory mucosa composed of homogeneous small round cells which contain neurosecretory granules. Melanin has been detected in such tumours only occasionally. Here we describe a new case of ESTH with divergent differentiation. The primary neoplasm was found in a 67 year-old female, involving the left nasal and maxillary sinus; she died of cerebral metastasis ten months after diagnosis. Histologically only small round cells were seen, with S-100 and NSE positivity. Electron microscopy revealed neurosecretory granules and filaments, as well as the occasional presence of melanosomes. A nude mice xenograft line has been established, and is presently in its ninth transfer. Two cell types are present: small round-to-spindle shaped cells with neural features, and large epithelial-like ones. Both immunohistochemistry and electron microscopy confirm this dual differentiation, with the presence of membrane-bound dense-core neural secretion, as well as melanosomes of neuroectodermal origin. Additionally, an in vitro cell line has been established. Cytogenetic analysis confirmed the presence of both malignant human melanoma patterns; non-random abnormalities in chromosomes 1 and 6, extra copies of chromosome 7. Duplication of the long arm of chromosome 14, as seen in olfactory neuroblastoma, is also seen.

Aged↗
PubMed1988

Mercury content of some marine fish from the southern Caribbean Sea.

The mercury concentration in muscle and liver of 63 specimens, comprising 17 species of edible fish from coastal waters of the Caribbean Sea near Cumaná, was determined by cold vapour atomic absorption spectrophotometry. The Hg content of edible muscle tissue, expressed on a fresh weight basis, varied from 0.048 microgram g-1 in lisa (Mugil curema) to 0.190 microgram g-1 in tajali (Trichiurus lepturus), with an average value of 0.096 +/- 0.042 microgram g-1. The corresponding values for liver varied from 0.135 microgram g-1 in lebranche (Mugil brasiliensis) to 0.361 micrograms g-1 in tajali (Trichiurus lepturus), with an average value of 0.269 +/- 0.059 microgram g-1. Of the 17 species analysed, seven had a mercury concentration greater than 0.10 microgram g-1 and the remainder contained less than 0.08 microgram g-1 in edible muscle tissue.

Animals↗
PubMed1971

Cortisol in the cerebrospinal fluid of patients suffering from affective disorders.

Cortisol concentration was estimated by a competitive protein-binding method in the lumbar cerebrospinal fluid (CSF) of patients suffering from depression or from mania, and compared with the CSF cortisol concentration of neurological control patients not suffering from an affective disorder. There were no significant differences between the groups.

Affective Symptoms↗