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Biomedical subjects

A Borges

Publications and source records attributed to A Borges.

71 records · Page 4Linked to original sources
PubMed1983

12-0-Tetradecanoylphorbol-13-acetate-induced amplification of mesenchymal tumorigenesis in the mouse skin.

Skin tumors were induced in 6-week-old female Swiss albino mice by a single subcutaneous (SC) injection of 20-methylcholanthrene (MCA) in the right scapular region and the animals were then divided into four groups. Mice in group I did not receive further treatment. Six weeks after MCA injection, those in groups II and III received twice weekly applications of 0.1 ml acetone and 1.8 nmol 12-0-tetradecanoylphorbol-13-acetate (TPA) in 0.1 ml acetone, respectively, at the site of MCA injection until tumor development. Group IV animals were divided into four subsets and administered two, four, six, or eight TPA applications commencing 6 weeks after carcinogen injection. The effect of TPA pretreatment on MCA-induced tumorigenesis was studied in animals in group V. In mice treated with MCA alone, the most predominant mesenchymal tumor type is fibrosarcoma with induction of some rhabdomyosarcomas. Mixed mesenchymal tumors consisting of fibrosarcoma, rhabdomyosarcoma, or hibernoma were observed in only 12% of the animals. The number of animals bearing mixed mesenchymal tumors such as fibrosarcoma, rhabdomyosarcoma, hibernoma, and/or liposarcoma increased to 46% in mice receiving MCA + TPA until tumor development. Interestingly, liposarcomas were not found at all in animals treated with MCA alone. The data indicates that TPA application to precancerous mouse skin enhances mesenchymal tumorigenesis.

Animals↗
PubMedDate not supplied

Chondroid tumors of the larynx: computed tomography findings.

PURPOSE: Chondromas and chondrosarcomas of the larynx are rare cartilaginous tumors making up less than 1% of all laryngeal tumors. Patients typically present with symptoms of hoarseness, dysphagia, or dyspnea. The most common location in the larynx for these tumors is the cricoid cartilage. Radiographically, these lesions are typically hypodense, well-circumscribed masses containing mottled calcifications with smooth walls centered within the cartilage. MATERIALS AND METHODS: We present 6 cases of chondroid tumors of the larynx. RESULTS: One patient had a chondroma, 4 patients had low-grade chondrosarcomas, and 1 patient had an intermediate-grade chondrosarcoma. Two partial laryngeal resections and 4 total laryngectomies were performed. CONCLUSIONS: In most cases of chondroma or chondrosarcoma of the larynx, conservative surgery should be attempted, but total laryngectomy may be required for large or recurrent lesions.

Adult↗
PubMedDate not supplied

MR-guided procedures using contemporaneous imaging frameless stereotaxis in an open-configuration system.

Frameless MR-guided procedures have had limited application using conventional closed magnets, due largely to the technical difficulties involved. As a result of in-room MR image-monitoring capabilities, new open-design magnets now allow frameless stereotaxis using contemporaneous imaging to guide more invasive procedures. We evaluate our clinical experience with this new technique. An open-design 0.2 T magnet (Siemens OPEN) combined with an in-room monitor was used for 33 frameless MR-guided procedures (aspiration cytology, biopsy, and/or treatment) in a variety of locations in the head, neck, spine, brain, pelvis, and abdomen. Success of the procedure was based on the ability to accurately position the instrument in the target region to allow biopsy and/or treatment. The open-design magnet allowed the physician to directly access the patient for frameless stereotaxis as the procedure was performed. The in-room monitor provided contemporaneous imaging feedback during the procedure for successful placement of the instrument in the target region. Twenty-eight biopsy and five treatment procedures were performed. In all cases the technique resulted in successful placement of the instrument within the target tissue to complete the procedure. MR-guided procedures using contemporaneous imaging frameless stereotaxis are possible in an open-design magnet with in-room image monitoring and offer exciting possibilities for further development.

Adolescent↗
PubMedDate not supplied

Giant fibrovascular polyp of the oropharynx.

We describe a case of a giant fibrovascular polyp arising from the oropharynx and causing vague clinical symptoms. To our knowledge, this is the first description of an oropharyngeal fibrovascular polyp reported in the medical literature. The diagnosis was based on MR imaging findings, which showed the size and configuration of the polyp as well as the site of attachment. The patient underwent surgery, and the diagnosis was confirmed histologically.

Diagnosis, Differential↗
PubMedDate not supplied

Retroperitoneal extraosseous osteosarcoma. A case report and review of literature.

Extraosseous osteogenic sarcoma is a rare and highly malignant neoplasm. A 57 year old male patient presented with a mass in the abdomen involving the left lumber region. The ultrasound and computerized tomography (CT) scan showed a large mass arising from upper pole of the left kidney. Left radical nephrectomy was performed in April 1995. Histopathology report revealed a high grade extraosseous osteogenic sarcoma. Patient was disease free for 23 months. Although the prognosis is grave, aggressive surgical treatment with adjuvant therapy helps in prolonging the survival.

Abdominal Pain↗
PubMedDate not supplied

[Abortion...].

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Abortion, Induced↗