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Biomedical subjects

M W Lingen

Publications and source records attributed to M W Lingen.

25 records · Page 2Linked to original sources
PubMed1996

Retinoic acid induces cells cultured from oral squamous cell carcinomas to become anti-angiogenic.

Retinoids have shown great promise as chemopreventive against the development of squamous cell carcinomas of the upper aerodigestive tract. However, the exact mechanism by which they block new tumors from arising is unknown. Here, we report that 13-cis- and all-trans-retinoic acid, used at clinically achievable doses of 10(-6) mol/L or less, can directly and specifically affect cell lines cultured from oral squamous cell carcinomas, inducing them to switch from an angiogenic to an anti-angiogenic phenotype. Although retinoic-acid-treated and untreated tumor cells make the same amount of interleukin-8, the major inducer of neovascularization produced by such tumor lines, they vary in production of inhibitory activity. Only the retinoic-acid-treated cells produce a potent angio-inhibitory activity that is able to block in vitro migration of endothelial cells toward tumor cell conditioned media and to halt neovascularization induced by such media in the rat cornea. Anti-angiogenic activity is induced in the tumor cells by low doses of retinoids in the absence of toxicity with a kinetics that suggest that it could be contributing to the effectiveness of the retinoids as chemopreventive agents.

Animals↗
PubMed1996

Inhibition of squamous cell carcinoma angiogenesis by direct interaction of retinoic acid with endothelial cells.

Retinoic acid (RA) is a multifunctional drug that is particularly effective at preventing the development of multiple primary oral squamous cell carcinomas. A portion of this activity is due to the inhibition of tumor angiogenesis. It has been thought that RA influences tumor angiogenesis only via its interactions with the tumor cells themselves. Here, we test the hypothesis that the drug can also block neovascularization by directly inhibiting the angiogenic activity of normal endothelial cells. Clinically achievable doses of RA rapidly caused large- and small-vessel endothelial cells to become refractory to stimulation of migration either by tumor-conditioned media or purified angiogenic factors (a-fibroblast growth factor (aFGF), bFGF, vascular endothelial GF, platelet-derived GF, TGF beta-1, and IL-8). However, RA had little effect on their proliferation. Inhibition of migration was complete within 3 hours and was reversed 36 hours after drug removal. The migration of human oral keratinocytes was not sensitive to RA, whereas the migration of fibroblasts and vascular smooth muscle cells was inhibited. To determine if systemic RA affected neovascularization, rats were given 1 mg/kg/day of all-trans RA and their angiogenic potential was tested by implanting pellets of tumor-conditioned media into their avascular corneas. This treatment rendered the rats unable to mount a neovascular response in their corneas. These data demonstrate that RA directly affects endothelial cells, rapidly and reversibly inhibiting their ability to migrate toward a variety of stimuli in vitro and halting the formation of new vessels in vivo. These direct effects on vascular cells seem likely to contribute to the success of RA as a chemopreventive agent for oral squamous cell carcinoma.

Animals↗
PubMed1995

Myofibromas of the oral cavity.

Solitary infantile myofibromatosis or myofibroma of the oral cavity is an uncommon condition with only 32 reported cases in the English-language literature. This article presents four additional cases of these solitary myofibroblastic lesions. In addition, the clinical and histologic features of this uncommon spindle cell neoplasm have been reviewed. The similarity in both the clinical and histopathologic features of the "adult" and "infantile" lesions support the proposal that myofibroma is a more accurate and acceptable term for these solitary myofibroblastic lesions of the oral cavity.

Actins↗
PubMed1993

Unusual presentation of a chondromyxoid fibroma of the mandible. Report of a case and review of the literature.

Chondromyxoid fibromas are uncommon central bone tumors that are most often found at the proximal metaphyses of long bones. Chrondromyxoid fibromas of the jaws are very rare with only 18 reported cases in the literature. This article reports on a recurrent chondromyxoid fibromas of the mandible in a 10-year-old boy. In addition, a literature review of the clinical and histologic features, as well as the diagnostic pitfalls and recommended modalities of treatment are presented.

Child↗
PubMedDate not supplied

Primary ectopic meningioma of the maxillary sinus: case report and review of the literature.

METHODS: A case of a primary ectopic meningioma, arising within the right maxillary sinus, is presented. A review of English literature was also undertaken to determine the prevalence of these lesions in this specific anatomic location. RESULTS: A total maxillectomy was performed without complications and the surgical defect was covered with an immediate obturator. The patient is well and without evidence of disease 3 1/2 years postoperatively. A review of the English literature revealed four additional reports of primary ectopic meningiomas that were limited to the maxillary sinus. CONCLUSIONS: Primary ectopic meningiomas of the maxillary sinus are uncommon lesions which have a good prognosis when a complete resection of the neoplasm can be performed.

Adolescent↗