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Biomedical subjects

T M Davidson

Publications and source records attributed to T M Davidson.

At least 55 records · Page 3Linked to original sources
PubMed1994

Endoscopic resection of a sphenoethmoid osteoma: a case report.

Osteomas are slow-growing neoplasms of the paranasal sinuses. The previously used management of symptomatic osteomas has consisted of open excision utilizing one of several approaches. Endoscopic sinus surgery offers a convenient, safe and effective alternative to open procedures and can be safely performed in well-selected cases of ethmoid osteoma. The reduced morbidity, length of stay and superior cosmetic result are distinct advantages of this technique.

Adult↗
PubMed1994

Rattlesnake bites. Guidelines for aggressive treatment.

Significant envenomation from a rattlesnake bite can result in tremendous local tissue destruction, and severe envenomation can cause death. To avoid these outcomes, we recommend the aggressive infusion of antivenin (Crotalidae) polyvalent; 15 to 20 vials are required on average. Management considerations discussed in this article include hypersensitivity to horse serum, hematologic abnormalities, symptoms of envenomation, care of the bite site, and care of patients with severe symptoms.

Animals↗
PubMed1991

Scar revision.

Different scar revision techniques are compared on similar scars, all on the same patient. Comparison of the final results is unique and interesting and provides insight into choosing the "optimal" technique for these procedures. Historical perspective is provided.

Adult↗
PubMed1991

Envenomation by the colubrid snake Atractaspis bibronii: a case report.

A reptile caretaker was bitten and envenomated by Atractaspis bibronii while handling a box of "non-venomous" colubrid feeder snakes. The patient was bitten on a finger by a single fang. Pain and swelling were noted within 10 min and dissipated over the ensuing 3 days. This case report adds to the limited number of bites by A. bibronii already found in the literature and reviews what is currently known about the species.

Animals↗
PubMed1991

Selective hypnotic amnesia: is it a successful attempt to forget or an unsuccessful attempt to remember?

Subjects in 2 experiments (ns = 72 and 50) learned a 16-item, 4-category word list and were then administered hypnotic suggestions to be amnesic for all the words in 1 of the categories. Even when selective amnesia was completely successful, subjects in both experiments revealed a high level of recall for words not targeted for amnesia; moreover, these words were recalled in a highly organized, category-by-category fashion. Evidently, attention to relevant retrieval (i.e., organizational) cues does not oblige recall of words targeted for amnesia. Forgetting in the presence of such powerful mnemonic cues seems to characterize hypnotic amnesia and some spontaneous forms of forgetting as well. We argue that mnemonic lapses of this kind represent a failed attempt to remember rather than a successful attempt to forget.

Amnesia↗
PubMed1991

Preservation of facial contour during parotidectomy.

Parotid surgery often leaves a facial contour deformity. Free abdominal dermal-fat grafts were used to preserve the facial contour of nine patients undergoing parotid surgery. This procedure is simple to perform and provides an improved cosmetic result without significantly increasing operative time or lengthening hospitalization. No troublesome fat absorption occurred postoperatively. The dermal-fat graft also serves as a barrier to regenerating neurons, thereby preventing postoperative gustatory sweating.

Abdomen↗
PubMed1991

The rhinologic evaluation of Alzheimer's disease.

Olfactory dysfunction is currently not listed among the NINCDS-ADRDA clinical criteria for the diagnosis of Alzheimer's disease. There is a large amount of psychophysical and neuropathologic evidence to suggest that patients with Alzheimer's type dementia have olfactory system abnormalities. The rhinologic status of this group has not been characterized. The authors examined 21 Alzheimer's patients and 21 age-matched controls to determine whether 1. the Alzheimer's group, in fact, had a diminished sense of smell, and whether 2. rhinologic factors were responsible for this nasal dysfunction. The findings support a neurologically mediated phenomenon as the cause for significant impairment in olfactory function in patients with probable Alzheimer's disease.

Aged↗
PubMed1988

The lung volume at which shunting occurs with inhalation anesthesia.

The relationship between functional residual capacity (FRC) and shunt development with halothane anesthesia in 18 nonobese surgical patients (age, 21-34 yr) was studied. FRC was measured by helium dilution, and intrapulmonary shunt was distinguished from ventilation-perfusion inequality by multiple tracer inert gas elimination analysis. Awake supine FRC was 34.6 +/- 6.6% (mean +/- SD) of total lung capacity (TLC), and closing capacity (CC) was 29.8 +/- 5.3% of TLC. Anesthesia, muscle paralysis, tracheal intubation, and mechanical ventilation produced an average 14.6 +/- 13.3% FRC reduction to an average anesthesia FRC 29.8% of TLC (P = 0.002). Shunt increased from 1.2% +/- 1.5% awake to 8.6 +/- 8.3% during anesthesia (P = 0.005). A nonlinear relationship was found between shunt and FRC/TLC so that anesthetized subjects with an FRC less than awake CC had an average 11.4 +/- 8.3% shunt, whereas subjects with an FRC greater than CC had a 2.4 +/- 2.8% shunt (P = 0.025). Nonsmokers developed shunt only if FRC was less than CC. Smokers showed a significantly higher shunt for a given (FRC-CC)/TLC compared to nonsmokers (P less than 0.001). The slope of the regression of shunt on BMI (body mass index = weight/height2) showed a significant increase during anesthesia (P = 0.005), and smokers had a significantly higher slope compared to nonsmokers (P = 0.001). These findings suggest a gravity-dependent mechanism for intrapulmonary shunting during anesthesia. Therefore, shunting was due to dependent regional lung volume reduction associated with an FRC decrease to less than closing capacity. The enhanced intrapulmonary shunting in smokers may have been related to the increased dependent regional residual volume associated with smoking.

Adult↗
PubMed1988

MOHS for head and neck mucosal cancer: report on 111 patients.

Microscopically Oriented Histologic Surgery (MOHS) has been applied to primary epidermoid cancers of the mucosal tissues of the head and neck since 1979. In that time we have treated 170 patients and maintained excellent records, losing no patients to follow-up. One hundred three patients have been followed for 2 years. Of this group, only nine patients have developed local recurrences; three were salvaged, six were not. This presentation reviews the concept of MOHS and its application to head and neck mucosal lesions. The results are analyzed, and conclusions are drawn regarding what we have learned about the biologic behavior of head and neck tumors and the role of MOHS in treating these neoplasms.

Carcinoma, Squamous Cell↗
PubMed1988

Intravenous rattlesnake envenomation.

Intravenous envenomation by North American rattlesnakes is an uncommon occurrence, but a true emergency. In three documented, successfully resuscitated cases, the mainstay of treatment was the immediate intravenous administration of antivenin.

Adult↗
PubMed1987

Microscopically oriented histologic surgery for head and neck mucosal cancer.

Frozen section directed surgery, called MOHS, has been successfully utilized in the resection of primary epidermoid tumors of the head and neck. For the 93 cases reviewed in this study, 70% had microscopically identified tumor 1 cm away from clinically evident disease. Tumor spread was along planes of least resistance, most commonly in the submucosa. Microscopically directed excisions were able to trace and remove these tumor extensions. Local control in 93 patients with 2-year follow-up was 91% and, with salvage of recurrences, was 95%. The authors' observations suggest three important concepts. First, epidermoid cancer of the head and neck grows as a continuous neoplasm. Second, this work casts serious doubt on the concept of "field cancerization" or multiple primaries as a cause of local recurrence. Third, conventional frozen section analysis of surgical margins is highly unlikely to discover microscopic extensions because many tumor extensions are thin, finger-like projections which require examination of the entire surgical margin to detect.

Carcinoma, Squamous Cell↗