Biomedical subjects

D E Wolfman

Publications and source records attributed to D E Wolfman.

4 recordsLinked to original sources

PubMed1993

Systemic osteoclast activation by localized pressure.

It has been demonstrated that positive air pressure applied to the bulla of the Mongolian gerbil results in significant osteoclastic activation and bone resorption. In this study, continuous positive air pressure of 15 mm Hg was applied to the right bulla for 1 week. A significant increase in osteoclast number and surface were noted in the contralateral, unpressurized bulla as well as in a distant site, the upper extremity (radius). Possible mechanisms are discussed by which a local stimulus (pressure) may cause distant osteoclast activation.

Air Pressure↗

PubMed1986

Osteoclast stimulation by positive middle-ear air pressure.

The mechanism of pathologic bone resorption associated with cholesteatoma is controversial. It is now evident that transmitted pressure is a significant factor in the activation of osteoclasts. Previous studies on the effect of pressure have been confounded by the possible foreign body effect of materials placed into the middle ear to induce the pressure. Positive air pressures were maintained in the middle ear of Mongolian gerbils via implanted Silastic catheters. Histologic evaluation of the ventral bulla wall was performed after pressure had been applied for two weeks. A significant increase in the number density, area density, and size of osteoclasts present in the pressurized bullae was noted at pressures of 4, 6, 10, and 20 mm Hg, but not at 2 mm Hg. We conclude that minute increases in pressure, in the absence of foreign objects, stimulate osteoclastic bone resorption in the middle ear of the gerbil.

Animals↗

PubMed1986

Typhus-induced facial necrosis.

A patient with open wounds on his hands developed a severe case of typhus following exposure to a wild rabbit. Typhus resulted in extensive necrosis of the mid-face, including the nasal alae, pinna, and lips. The patient also sustained extensive extremity necrosis. A brief review of the epidemiology, pathophysiology, and treatment of this cause of facial necrosis is presented, as well as a discussion of dopamine gangrene. While this uncommon entity probably played a large part in the necrosis of this patient's extremities, these peripheral lesions are also compatible with typhus.

Adult↗

PubMedDate not supplied

Experimental retraction pocket cholesteatoma.

An animal model for retraction pocket (primary acquired) cholesteatoma is presented. Bilateral eustachian tube obstruction by electrocauterization of the nasopharyngeal portion was performed in 16 Mongolian gerbils. Animals were killed at 2, 4, 8, and 16 weeks. At 2 weeks all animals had bilateral serous effusions and retracted tympanic membranes. At 4 weeks, four of eight ears had middle ear fluid, retractions, and cholesteatomas. After 8 weeks, five of eight ears had middle ear effusions, and four of these had cholesteatomas; one ear had total atelectasis with a cholesteatoma filling the bulla. By 16 weeks, six of eight ears had developed cholesteatomas. Some animals did not develop effusion or retraction because of failure or recanalization of eustachian tube obstruction. This study provides experimental evidence that aural cholesteatomas may arise by retraction of the tympanic membrane.

Animals↗