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J Hassoun

Publications and source records attributed to J Hassoun.

At least 127 records · Page 7Linked to original sources
PubMed1984

Paired twisted filaments: a new ultrastructural marker of human pinealomas?

Paired twisted filaments (PTF) forming helices are described in tumor cells of three human pinealomas. Each filament was 8.11 +/- 1.55 nm wide. The maximal width of the helix was 16.62 +/- 2.62 nm. The periodicity of the constrictions was 26.63 +/- 4.49 nm. These characteristics appeared original, suggesting protein filaments possibly specific of pinealocytes. The similarities and discrepancies between PTF and Alzheimer's paired helical filaments (PHF) are discussed.

Adult↗
PubMed1984

Biochemical characterization of 17 beta-hydroxysteroid dehydrogenase in human meningioma.

17 beta-Hydroxysteroid dehydrogenase (E2-DH) activity was characterized on a semipurified microsomal preparation of human meningioma tissue (mean Km of 2 microM and Vmax of 500 pmol/mg protein/10 min) and then assayed in 49 meningioma specimens with high progesterone receptor and low estrogen receptor levels. Of these 49 tumors, 36% contained an E2-DH activity greater than 1,000 pmol/mg protein/10 min and similar to that of uterine myometrium. In this limited series of tumors, no correlation between E2-DH activity and progesterone receptor levels was noted.

17-Hydroxysteroid Dehydrogenases↗
PubMed1984

A human pituitary adenoma secreting thyrotropin and prolactin: immunohistochemical, biochemical, and cell culture studies.

A 43-yr-old woman, who had previously had a subtotal thyroidectomy, presented with hyperthyroidism and amenorrhea-galactorrhea due to a pituitary adenoma secreting TSH, TSH-alpha, and PRL. Her serum T4 concentration was 14 micrograms/dl; T3, 5.7 ng/ml, and TSH, 19-33 microU/ml. Serum TSH was not altered by TRH stimulation or T3 suppression. Basal plasma PRL levels were 19-27 ng/ml and plasma PRL doubled after TRH stimulation. A 900-mg pituitary tumor, removed by transphenoidal surgery, was studied in cell culture. After dispersion, tumor cells were maintained on an extracellular matrix produced by bovine corneal endothelial cells in a defined serum-free medium. The hormones released in the culture medium were analyzed by high pressure gel chromatography. Three fractions of tumor TSH were found, with respective apparent mol wts of 45,000 (11%), 28,000 (70%), and 20,000 (19%). Tumoral PRL eluted as a single peak of apparent mol wt of 24,000. Pharmacological studies of TSH, TSH-alpha, and PRL release using thyroid hormones (T3), dopamine agonist (bromocriptine), TRH, and cholera toxin yielded the following results: 1) T3 after 3 days of incubation produced a dose-dependent inhibition of TSH, TSH-alpha, and PRL release. Maximal inhibition (81%) was obtained at 10(-9) M and half-maximal inhibition at 4-6 X 10(-11) M. 2) Bromocriptine produced rapid and partial inhibition of hormone release. Maximal inhibition (51%) was obtained at 10(-8) M and half-maximal inhibition at 5 X 10(-10) M. 3) TRH at 10(-8) M concentration significantly stimulated PRL release but it had no effect on TSH release. 4) Adenylate cyclase activation by 10(-11) M cholera toxin increased TSH (152%), TSH-alpha (150%), and PRL (220%). Immunohistochemical analysis of serial 2 micron sections of the tumor showed that: 1) TSH-alpha immunoreactive cells were the most numerous, 2) TSH-beta positive cells were always positive for TSH-alpha, 3) PRL immunoreactivity was found either uniquely in some cells and colocalized with TSH-alpha immunoreactivity in other cells. However, by electron microscopy, the tumor cells were thyrotrophs. These data indicate that in this patient's tumor: 1) cells secreting TSH were responsive in vitro to near physiological concentrations of thyroid hormones. 2) The colocalization of PRL and TSH-alpha immunoreactivities in some cells raises the possibility either of fusion of differentiated pituitary cells synthesizing distinct hormones or of transformation of less differentiated multipotential pituitary cells.

Adenoma↗
PubMed1984

Immunohistochemical study of pheochromocytomas. An investigation of methionine-enkephalin, vasoactive intestinal peptide, somatostatin, corticotropin, beta-endorphin, and calcitonin in 16 tumors.

Immunohistochemical investigations were carried out on 16 pheochromocytomas for a study of their immunoreactivity to methionine-enkephalin, vasoactive intestinal peptide, somatostatin, corticotropin, beta-endorphin, and calcitonin on serial semithin araldite sections. All antiserums except anti-beta-endorphin, selectively stained a variable number of distinct tumor cells. Methionine-enkephalin-immunoreactive cells were the most frequent. The neuropeptide content of pheochromocytomas appears highly diverse and unpredictable. These findings are supportive of the concept of multisecretory APUD cells of neural crest origin and rule out any of these neuropeptides as reliable immunohistochemical markers for tumor chromaffin cells.

Adolescent↗
PubMed1984

[Meningeal fibrosarcomas].

The authors present 4 operated cases of primary fibro sarcomas of the dura mater. Only, a few number of cases had been described in the literature. In Zulch's classification (1957) of 6000 brain tumors, there were 162 cases of sarcoma (i.e. 2,7%) and among sarcoma, 30 cases of fibrosarcoma of the dura mater. In according with the WHO classification of brain tumors (Zulch, 1979), the primary fibrosarcoma of the dura mater takes place in the group of meningeal sarcomas with the polymorphic cell sarcoma and the primary meningeal sarcomatosis. The pre-operative diagnosis is difficult, because neither clinical data, neither neuroradiological findings are characteristics. The prognosis of the patients with this tumor is poor, however some examples are known to have had a long post-operative survival. The association: complete surgical extirpation--post-operative radiation appears like to best treatment. Pathological examination showed in our four tumours, the features of fibroblastic sarcomas with haemorrhagic zones and foci of osteoid metaplasia. The ultra-structural study in 2 cases, confirmed the specificity of tumoral cells which did not display any histological similarity to the arachnoïdal cells. In one case, a myofibroblastic differentiation was evident, and thus, confirmed the plasticity of tumoral fibroblastic cells. The immuno-histochemical reaction of GFAP revealed reactive astrocytic areas in one case inside the immuno-histochemical sarcomatous tissue.

Aged↗
PubMed1984

[Alexander's disease in an adult].

A 34-year-old man developed cerebellar symptoms, palatal myoclonus and spastic paraparesis progressing over several months. During this period, acute respiratory failure occurred in two instances with evidence of central chronic hypoventilation. CT scan showed enlargement of the frontal horns and posterior fossa cisterns. Post mortem examination revealed the following features: 1) Rosenthal's fibers widespread throughout the CNS but especially in subependymal regions; 2) bilateral white matter cavitations involving the frontal lobes, hilum of dentate nuclei and bulbar pyramids; 3) microscopic pseudogliomatous foci present in several sites, especially in the fornix and midbrain tegmentum; 4) the medulla and high cervical spinal cord showed "peripheral type" myelin fibers along with Schwann cell proliferation in aberrant intra-parenchymal situation. The relationship of this case--as well as the few previous adult reports--to the well-defined infantile Alexander's disease is discussed. The possible hamartomatous nature of both glial changes and aberrant myelin production is emphasized. These various lesions, including Rosenthal fiber formation, are assumed to result from a similar--probably dysontogenetic--pathophysiological mechanism. It is suggested that Alexander's disease, in this case, should be classified among phakomatoses rather than enzymopathic leukodystrophies.

Adult↗
PubMed1983

[Contribution of electron microscopy to the diagnosis of cerebral tumors].

The authors comment on the role of electron microscopy in the diagnosis of brain tumors. This kind of morphological investigation is essential for the differential diagnosis of undifferentiated or round cell tumors, especially on small biopsies. In addition, electron microscopy clarifies the nosology of numerous entities, such as germinomas, lymphomas, astrocytic gliomas, neuronal tumors, medulloblastomas and pinealomas. Finally numerous ultrastructural details are provided, widening our knowledge of the complex pattern of brain tumors.

Brain Neoplasms↗
PubMed1983

Specific ultrastructural markers of human pinealomas. A study of four cases.

An ultrastructural study of four pinealomas was carried out to precise eventual specific markers. Dark and clear cells joined with zonulae adherents, extensive and pleiomorphous processes, a complex vacuolar system, and characteristic organelles (lysosome-like structures, clear and dense-core vesicles, vesicle-crowned rodlets and related structures, microtubular sheaves and centriolar derivatives, membranous whorls, fibrous bodies, microtubules, heterogeneous cytoplasmic inclusions) offered a typical pattern. No correlation could be made between the histological and ultrastructural features. The authors stress the ultrastructural similarities between the human tumor cells and the mammalian pineal cells. Pinealomas appeared as a morphological entity distinct from neuronal and astrocytic tumors.

Adolescent↗
PubMed1982

Calcitonin, somatostatin and ACTH immunoreactive cells in a case of familial bilateral thyroid medullary carcinoma.

Bilateral medullary carcinoma of the thyroid (MCT) was discovered in a symptomless patient of a high-risk MCT family. Raised serum calcitonin responding abnormally to pentagastrin led to a thyroidectomy. Grossly, the thyroid showed one nodule in the upper third of each lobe. Light microscopy revealed typical MCT with amyloid deposits. Nontumoral thyroid tissue showed C cell parafollicular hyperplasia. Electron microscopy detected intracellular secretory granules (mean diameter, 150 nm) and typical amyloid fibrills. Immunochemistry revealed numerous calcitonin immunoreactive cells in the nodules, in normal para and intrafollicular C-cells and hyperplastic C-cells. Somatostatin and ACTH were detected in certain tumor cells, but not in normal and hyperplastic C-cells. MCT hormonal production potential is discussed.

Adrenocorticotropic Hormone↗
PubMed1982

[Advances in diagnosis and treatment of oligodendrogliomas of the brain. Eighty-four surgical patients (author's transl)].

The authors report their experience of 84 patients with oligodendroglioma seen over a 34 year period. The low incidence of these brain tumors is underlined. Oligodendroglioma is the most epileptogenic of brain tumors. The clinical picture may resemble "essential" epilepsy. Normal EEG should be considered suspect in confirmed epileptic children and adolescents since oligodendroglioma is the most common of all tumors which induce long-standing epilepsy. Emphasis is put on the importance of computerized tomography and radionuclide scanning for early detection of these tumors. Both procedures are very helpful for deciding on the best operative approach and for determining whether the lesion is malignant or not. The authors advise tumorectomy, which should be as complete as possible, followed by systematic radiotherapy, even if histopathological criteria indicate a benign tumor. With this therapeutic regimen mean survival rates are significantly higher than those published previously.

Adolescent↗
PubMed1982

Complex cerebral tumor with evidence of neuronal, glial and Schwann cell differentiation: a histologic, immunocytochemical and ultrastructural study.

An unusual cerebral tumor is reported in a ten-month-old boy. The tumor was large (10 cm x 6 cm), firm and included several cysts. Light and electron microscopy showed a striking cellular pleomorphism. Typical neurosecretory ganglion cells were observed, always surrounded by Schwann cells. Amyelinic neurites, clusters of Schwann cells, fibroblasts and numerous foci of GFA positive astrocytes composed the tumor. These features were compared with the rare previous electron microscopic reports of cerebral neuronal tumor of the central nervous system. A dysembryoplastic origin from the neural plate was retained to explain the growth of such a complex tumor.

Brain Neoplasms↗
PubMed1982

Corticolipotropin immunoreactivity in silent chromophobe adenomas: a light and electron microscopic study.

Twenty silent human pituitary adenomas were morphologically studied. Immunoperoxidase methods showed numerous adrenocorticotropic hormone-immunoreactive tumor cells in 14 cases by light microscopy and in one additional case by electron microscopy. Three of these cases were positive for beta-endorphin and one for beta-lipotropin by electron microscopy. These immunoreactions were found in undifferentiated tumors as well as in oncocytic adenomas, and could not be related to the presence of basophils by light microscopy. The peptides so detected in silent adenomas may have no biological activity and may correspond to common precursor molecule subunits.

Adenoma, Chromophobe↗