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Biomedical subjects

J F Nunes

Publications and source records attributed to J F Nunes.

27 records · Page 2Linked to original sources

Ultrastructural study of African swine fever virus replication in cultures of swine bone marrow cells.

Cultures from pig bone marrow cells were infected with ASFV and the replication cycle was studied. In the cytoplasmic replication areas there are a differentiation of membrane segments. Some of them are polygonal, which give rise to virus particles. An over production of viral coded materials, including non-polygonal membranes seems to be an important feature of the replicative cycle of ASFV in this cell system. Viruses are released enveloped with a cellular membrane. Paracrystalline arrays of viruses are seldom seen in the cytoplasm. At no time did we see viruses in the nucleus. Infected cells showed marked cytopathic effect, beginning at early times post infection.

African Swine Fever Virus↗

Giant mitochondria and intramitochondrial inclusions in benign thyroid lesions.

Enlarged mitochondria and intramitochondrial dense structures have been reported to occur in a great variety of animal and human cells under normal, pathologic, and experimental conditions. Three cases of benign thyroid lesions are described in which large cytoplasmic inclusions were seen on light microscopy. These inclusions were stained with toluidine blue but not with Sudan black B, as was seen in consecutive sections. Ultrastructural observation showed that they corresponded to giant mitochondria. Bundles of dense filaments and round, electron-dense bodies were observed in the matrix of the enlarged mitochondria. Incubation of ultrathin sections with proteolytic enzymes (pepsin, trypsin, and type XVI-protease) led to a striking decrease in the electron density of both types of intramitochondrial matrical structures. These observations demonstrate that a major proteic component exists in intramitochondrial filamentous bundles and in dense bodies.

Adult↗

Mitochondria-rough endoplasmic reticulum complexes in a malignant fibrous histiocytoma.

Mitochondria-rough endoplasmic reticulum complexes identical to the ones usually found in chordoma were frequently observed in tumors cells of a malignant fibrous histiocytoma arising in the left thigh of a 48-year-old woman. Although the significance of these structures is unknown, this finding is consistent with the known transformation of chordoma into malignant fibrous histiocytoma.

Chordoma↗

Helioid inclusions in dedifferentiated acinic cell carcinoma of the parotid gland.

Helioid bodies are exceedingly rare, intranuclear, rounded inclusions with peripheral radiating filaments. These structures, which were formerly observed in only three cases of proliferative breast epithelial lesions, appeared in 0.5-1% of the neoplastic cells of a case of dedifferentiated acinic cell carcinoma of the parotid gland. Helioid bodies are related to rough endoplasmic reticulum cisternae, which suggests that they are the result of the condensation and partial crystallization of their contents when sequestrated into the nuclear compartment of the cell. The presence of helioid bodies may be related to secretory dysfunction of the tumor cells associated with the process of neoplastic dedifferentiation.

Carcinoma, Acinar Cell↗

[Ceroid-lipofuscinosis: ultrastructural study of 8 cases].

The authors studied the clinical and ultrastructural features of 8 cases of Neuronal Ceroid-Lipofuscinosis (NCL). Five cases of the late-infantile type and 3 cases of the juvenile type. The clinical diagnosis of all cases was confirmed by the electron microscopy analysis of the peripheral blood lymphocytes and biopsy material from the skin, palpebral conjunctiva, skeletal muscle and rectal mucosa. Our observations agree with previous reports concerning the predominance of curvilinear bodies in the cells of the late infantile type, and fingerprint-like structures in those of the juvenile type. The finding of parallel tubular arrays and NCL inclusions associated in the same lymphocyte (frequently in the same vacuole) suggests that those structures could be related to the metabolic error of NCL. Ultrastructural examination of microbuffycoats of peripheric blood lymphocytes is a simple, time-saving and reliable method that allows specific confirmation of a clinical diagnosis of Neuronal Ceroid-Lipofuscinosis.

Adolescent↗