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David A Sirois

Publications and source records attributed to David A Sirois.

5 recordsLinked to original sources
PubMed2005

Cytotoxicity of liposomal alpha-tocopheryl succinate towards hamster cheek pouch carcinoma (HCPC-1) cells in culture.

There is compelling evidence for the cancer chemopreventive effects of vitamin E and related compounds. Of all the vitamin E derivatives that have been investigated to date, vitamin E acid succinate is the most effective anti-cancer agent. This report describes the preparation and testing of liposomal formulation of mono alpha-tocopheryl ester of succinic acid (alpha-TOS) for cytotoxicity against hamster cheek pouch carcinoma cell line (HCPC-1). Small unilamellar vesicles (SUV) of phosphatidylcholine incorporating 70 microM alpha-TOS were superior to alpha-TOS alone or SUV without incorporated alpha-TOS, as inducers of apoptosis in HCPC-1 cells. Liposomal alpha-TOS perturbed the lipid structure in cells, promoted apoptosis, and decreased cell viability. The mechanism of action of alpha-TOS appears to involve membrane damage and induction of ceramide mediated apoptosis.

Animals↗
PubMed2003

Structural and functional injury in minipig salivary glands following fractionated exposure to 70 Gy of ionizing radiation: an animal model for human radiation-induced salivary gland injury.

This study explored the feasibility of developing an animal model for radiation-induced salivary gland injury with a radiation protocol identical to current clinical practice. Three male Hanford minipigs were subjected to fractionated daily irradiation with a total dose of 70 Gy; structural and functional measures were compared with those of a control group of minipigs. We found that irradiated submandibular and parotid glands were one-third to one-half the gross size of control glands. Whereas no pathologic changes were noted in control glands, irradiated glands consistently demonstrated significant parenchymal loss with extensive acinar atrophy and interstitial fibrosis, enlarged nuclei in remaining acinar cells, and ductal dilatation and proliferation. Stimulated salivary flow was reduced by 81% in irradiated animals compared with preirradiation flow (P <.001); salivary flow in the control group increased by 30% during the same period (P <.001). The observed radiation-induced structural and functional salivary gland changes are comparable in every respect to those observed following irradiation of human salivary glands.

Animals↗
PubMed2002

Multiple intraoral melanoacanthomas: a case report with unusual findings.

Melanoacanthoma is a rare, benign, mucocutaneous pigmented lesion characterized by colonization of acanthotic epithelium by dendritic melanocytes.(1,2) The most common intraoral sites are the buccal(3,4) and masticatory mucosa subject to chronic irritation.(1,5) The pathogenesis of oral melanoacanthoma remains uncertain, although its clinical behavior is suggestive of a reactive cause.(3,4,6,7) The clinical appearance of melanoacanthoma is nondiagnostic, and biopsy is mandatory.(2,3,5,6,8) The lesion, however, requires no treatment(5) and elimination of local irritants as well as periodic observation are the recommended interventions.(1,8) We describe a 39-year-old black patient with a recently reported palatal melanoacanthoma who developed additional lesions in other intraoral sites approximately 3 months after the initial lesion was biopsied. This article also documents the reactive and reversible nature of intraoral melanoacanthoma in a rare case of multiple lesions.

Adult↗
PubMedDate not supplied

Dental care of patients with autoimmune vesiculobullous diseases: case reports and literature review.

Dental management of patients with autoimmune vesiculobullous disorders is complicated because of prominent involvement of oral mucosa, increased risk of oral disease, and difficulty in rendering dental care. Although these diseases are relatively uncommon, dental practitioners should be familiar with the oral sequelae of these conditions and their management. Pemphigus vulgaris, cicatricial pemphigoid, and epidermolysis bullosa represent the most common autoimmune oral vesiculobullous diseases. This case-illustrated review summarizes the pathogenesis, diagnostic features, and natural history of oral vesiculobullous disorders, placing an emphasis on the treatment and prevention of associated oral disease aimed at maintaining a healthy, functional dentition.

Adult↗