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Biomedical subjects

W Raslan

Publications and source records attributed to W Raslan.

8 recordsLinked to original sources
PubMed1995

Effect of magnetic resonance imaging on implantable eyelid weights.

Implanted upper eyelid gold weights are used to prevent corneal injury in patients with facial nerve paralysis. Some of these individuals require postoperative radiographic surveillance for recurrent lateral skull base disease. Magnetic resonance imaging (MRI) provides the most accurate radiologic assessment; however, there is concern about the safety of performing MRI in patients with any metallic implant. Potential risks include local tissue heating and implant migration. Gold weights of 0.8 and 1.4 g were placed in an open chamber and were exposed to a magnetic field of 1.5 T. There was no measurable motion or displacement of the weights. The results were similar in 6 rats in which gold weights were subcutaneously implanted. Additionally, histologic examination of the implant sites revealed no adverse tissue effects attributable to MRI-generated heating of the implants. When carbon steel implants in the rat model were subjected to the magnetic field, there was no displacement of the implants and no adverse tissue effects were noted, despite the fact that a carbon steel implant in an open chamber demonstrated significant migration. The absence of motion of the gold weight implants combined with the lack of adverse tissue effects suggests the relative safety of performing MRI in patients with previously placed gold weights as upper eyelid implants.

Animals↗
PubMed1994

Extra-abdominal desmoid fibromatosis.

Desmoid fibromatosis cannot be considered a biologically benign or innocuous lesion. In the head and neck it may be intraosseous (desmoplastic fibroma) or, more often, in soft tissues, with the highest incidence in the supraclavicular region of the neck. High recurrence and persistence rates, 50% or more, accompany intralesional or marginal excision. Keloids and proliferative scars, while stubborn in their resolution and potentially disfiguring, are reactive proliferative disorders of fibroblastic and myofibroblastic tissues.

Bone Neoplasms↗
PubMedDate not supplied

The effect of isotretinoin on propylene glycol-induced cholesteatoma in chinchilla middle ears.

Previous studies have shown that propylene glycol causes inflammatory changes and cholesteatoma when applied to chinchilla middle ears. Vitamin A and synthetic analogues are essential for the normal differentiation of epithelial tissues. The purpose of this study was to determine whether the administration of isotretinoin to chinchillas would prevent propylene glycol exposure from inducing middle ear cholesteatomas. Sixteen chinchillas received 90% propylene glycol to the left middle ear and normal saline to the right. Half the animals were placed in the experimental group and received a daily dose of isotretinoin of 2 mg/kg for 7 days prior to propylene glycol administration and then for 6 weeks until killed. At 6 weeks, cholesteatoma was found in six of eight ears treated with propylene glycol in animals receiving isotretinoin. Two animals in the control group died. Three of the remaining eight had cholesteatoma. No ears treated with saline had cholesteatoma. We conclude that isotretinoin, in our chinchilla model, does not prevent propylene glycol-induced cholesteatoma formation.

Administration, Oral↗
PubMedDate not supplied

Complications in the approach to acoustic tumor surgery.

Earlier diagnosis and cooperation with allied specialists in neurosurgery have lessened complications of acoustic tumor surgery. To date, complications cannot always be prevented. The controversy over which approach is best for acoustic tumor extirpation still continues. While teams must answer this question themselves, our experience favors the transtemporal approach. Of the potential disabilities from this operation, facial paralysis or its sequelae remain the most frequent. The transtemporal approach gives a more accurate anatomical definition of the facial nerve. Efforts to preserve hearing (especially with tumors 2 cm or larger), when matched with the potential sequelae of facial paralysis, may prove futile.

Adult↗