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Biomedical subjects

P W Benoit

Publications and source records attributed to P W Benoit.

13 recordsLinked to original sources
PubMed1982

Mechanism of epinephrine enhancement of lidocaine-induced skeletal muscle necrosis.

Epinephrine significantly increases lidocaine-induced skeletal muscle necrosis, even in low concentrations that elicit no damage by themselves. Inasmuch as isoproterenol had no influence on lidocaine myotoxicity, a direct effect of epinephrine on muscle fibers is unlikely. Two vasoconstrictors with dissimilar mechanisms of action, phenylephrine and felypressin, duplicated the potentiating effect of epinephrine on fiber destruction in direct relation to their ability to retard lidocaine absorption from the tissue. It is concluded that the augmentation of muscle necrosis caused by epinephrine is largely due to its ability to increase exposure of skeletal muscle to the local anesthetic.

Animals↗
PubMed1981

Glomus tumor (golomangioma) of the tongue. A light and electron microscopic study.

A rare case of an intraoral glomus tumor on the ventral surface on the tongue was studied by light and electron microscopy. With light microscopy, the tumor was composed of dilated vascular channels surrounded by "epithelioid" glomus cells exhibiting large round nuclei and abundant eosinophilic cytoplasm. Bodian stains showed significant staining for nerve fibers among the tumor cells. Electron microscopic study demonstrated that the tumor cells had ultrastructural features which were similar to both smooth muscle cells and endothelial cells, suggesting that a "transitional" cell may give rise to glomus tumor. The literature on oral glomus tumors is briefly reviewed.

Female↗
PubMed1981

Comparison of myotoxic effects of lidocaine with epinephrine in rats and humans.

Myotoxic effects of 2% lidocaine with 1:100,000 epinephrine were evaluated in rats and humans. Sprague-Dawley rats were give injections in the left gastrocnemius muscle of 0.5 ml of the lidocaine preparation or a control vehicle; they were killed in groups of four at 0, 8, 24, and 48 hours. Blood samples were taken for serum enzyme determinations, and muscle specimens were removed and processed for histologic evaluation. In eight patients undergoing radical neck dissection, 1.8 ml of lidocaine with epinephrine or its control was injected into the sternocleidomastoid muscle approximately 18 hours before surgery. Patients' muscle specimens obtained at surgery were handled similarly to those of the rat. Serum creatine kinase, aspartate aminotransferase, and alanine aminotransferase activities were markedly elevated in the rat at 8 hours in the experimental group, but not in the control group. Histologically, control injections elicited no damage in the rat other than a mild inflammatory reaction along the presumptive needle track. Lidocaine with epinephrine, however, destroyed most of the muscle in which it was injected. Myonecrosis was qualitatively similar in humans. The rat provides a good model for the study of local anesthetic-induced myonecrosis.

Alanine Transaminase↗
PubMed1978

Microscarring in skeletal muscle after repeated exposures to lidocaine with epinephrine.

To assess the effect of repeated exposures to clinically used local anesthetic, rat thighs were given up to five supramuscular injections of 2% lidocaine with epinephrine, 1:50,000. Substantial damage to muscles followed by rapid regeneration occurred; however, in some areas evidence of retarded regeneration of muscles and microscarring was observed.

Anesthetics, Local↗
PubMed1976

Evaluation of a microcrystalline collagen preparation in extraction wounds.

The microcrystalline collagen preparation evaluated in this study appeared to create a slightly denser and longer lasting inflammation and to delay slightly the early phase of bone repair in this wound model. However, beneficial effects of more rapid achievement of hemostatis were also noted. On the basis of these findings, it would be of interest to compare this material with other more widely used materials, such as gelatin foam, in this wound model.

Animals↗
PubMed1976

Comparison of a microcrystalline collagen preparation and gelatin foam in extraction wounds.

A microcrystalline collagen preparation and a gelatin foam were compared relative to their effects on hemostasis and healing in molar extraction sockets in cats. The agents were essentially equivalent in both hemostasis and the inflammatory response that accompanied healing. Healing was slightly retarded in comparison to that seen in untreated control sockets in a previous study. It appears likely that the inflammatory response was caused by oral contamination, which is unavoidable in this type of procedure, rather than by the agents themselves.

Alveolar Process↗