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Biomedical subjects

F Llanes

Publications and source records attributed to F Llanes.

12 recordsLinked to original sources
PubMed2000

Magnetic nanostructured composites using alginates of different M/G ratios as polymeric matrix.

Alginate extracted from Sargassum fluitans and Macrocystis pyrifera with different molecular weights and mannuronic/guluronic ratios, M/G, were used as gel matrixes in order to obtain magnetic nanostructured composites. Magnetic nanocrystalline particles of iron oxides were formed inside the alginate matrix by in situ alkaline oxidation of ferrous ions. The magnetic materials obtained were subjected to several oxidative cycles and the increment in iron content was determined after each cycle. X-ray diffraction, magnetometry and Mössbauer spectroscopy were used to examine the materials. The high magnetic response, the absence of hysteresis, and the centered paramagnetic doublet in the Mössbauer spectra indicate the presence of nanocrystalline particles with a superparamagnetic behavior. X-ray diffractograms show peaks that correspond to maghemite. After the first cycle, Sargassum had four times the magnetic response of Macrocystis, which had more than twice the M/G ratio.

Alginates↗
PubMed1997

Triton tumor of the parotid area. Case report.

A 27-year-old woman with a Malignant Triton Tumor (MTT), or malignant schwannoma with rhabdomyoblastic differentiation, located in the parotid cell and infiltrating the nasal sinuses and the left orbit is described. The initially resected tumor showed three recurrences within a 2 years follow-up period. During successive recurrences an increase in cellular density, number of mitoses and necrosis was noticed. Immunohistochemical analysis showed that the tumor was composed of a mixed population of cells. Some of them showed positivity for actin, desmin and myoglobin, while others were positive for S-100 protein, glial fibrillary acid protein, and IV-collagen. Cytokeratin stainings were negative. Up to now, 8 benign triton tumors and another 45 cases of MTT have been described. None of them was primarily located in the parotid gland, and infiltration to the orbital cavity has not been previously described.

Actins↗
PubMed1996

Hepatocellular carcinomas diagnosed following metastasis to the oral cavity. Report of 2 cases.

Oral metastases from hepatocellular carcinomas are rare. Case 1 was a 66-year-old male without previous history of liver disease who presented with metastasis to the gingival jaw mucosae on the lingual side. Case 2 was a 71-year-old male, with a previous history of diabetes, hepatitis, and cirrhosis who presented with metastasis to the right palatine tonsil. Oral metastases were the first manifestation of the hepatocellular carcinoma in both cases. A review of the literature disclosed 20 cases of hepatocellular carcinoma metastasizing to the oral cavity, 7 affecting the gingival mucosae and none of them affecting the palatine tonsil.

Aged↗
PubMed1995

Metastatic lung carcinoma involving the periodontium. Report of a case.

A case of metastatic bronchogenic carcinoma to the gingiva in a 47-year-old male is reported. The gingival lesion developed as a quickly growing mass and appeared 2 months after surgical excision and radiotherapy of the lung carcinoma were completed. The gingival tumor was histopathologically diagnosed as a poorly differentiated squamous carcinoma. Comparative cytologic studies showed similarities between the gingival metastasis and the previous lung cancer.

Antigens, Neoplasm↗
PubMed1989

[Oral lymphomas in AIDS].

We present two cases of AIDS in drug-addicts, with mouth lymphoma. The diagnosis was established by a gum biopsy which gave high-grade non-Hodgkin lymphoma lymphoblastic "B" type. It is very rare that the oral mucous is affected by lymphomas, but in AIDS and immunodeficiencies it is more common.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Plexiform structures in malignant schwannomas after prenatal exposure to ethylnitrosourea.

75 Schwann cell tumors were induced in the offspring of Wistar rats which had been treated intraperitoneally with 15 mg/kg b.w. ethylnitrosourea on the 15th day of pregnancy. Plexiform structures characterized by poorly-developed, distorted and bizarre bundles of nerves were seen in 2 of 33 benign tumors, and in 17 of 42 malignant schwannomas. Since when seen in man similar findings are distinctive of neurofibromatosis, it is suggested that this experiment may offer a model for studying non-inherited forms of neurofibromatosis and, more particularly, the malignant changes often associated with this disease.

Animals↗
PubMed1979

[Retroperitoneal malignant xanthogranuloma. 1 case and a literature review].

A case is reported, the 33rd to be published in the literature, of malignant retroperitoneal xanthogranuloma. The tumor involved 2 cm of the right ureter at the junction between the middle and upper thirds. The middle third of the ureter was removed and ureteral continuity established by end to end ureteral anastomosis. The patient died fourteen months later probably from metastases, though the presence of these was not confirmed.

Diagnosis, Differential↗