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Biomedical subjects

T S Davis

Publications and source records attributed to T S Davis.

At least 19 recordsLinked to original sources

Murder and assault arrests of White House cases: clinical and demographic correlates of violence subsequent to civil commitment.

The authors studied arrest records and clinical data on 217 persons formerly hospitalized as "White House Cases" because they were psychotically preoccupied with prominent political figures. Prior arrest for violent crime was the variable most strongly associated with arrest for violent crime after hospital discharge. Male gender and a history of weapons possession were also correlated with future violence. For those with prior violent crime arrests, hospital incidents requiring seclusion were also associated with later violence. For those without prior arrests, subsequent violence was associated with threats, living outside Washington, and command hallucinations. For those previously arrested for nonviolent crimes, only persecutory delusions were associated with later violence.

Commitment of Persons with Psychiatric Disorders

Marked heterogeneity of aromatase activity in human malignant melanoma tissue.

The prognosis from human malignant melanoma varies according to sex and to multiple histologic, biologic and cell kinetic parameters. Thus melanomas exhibit a major degree of heterogeneity in their biologic properties and further characterization of their biochemical heterogeneity should yield important information. The present study sought to demonstrate the activity of a biochemical marker of estrogen synthesis, the aromatase enzyme, in melanoma tissue and to determine its range of activity. Initially, we validated a highly sensitive radiometric assay for aromatase by comparing it with a direct product isolation method. We detected production of 417 pmol/g protein/h of estrone and 37.3 pmol/g protein/h of estradiol by direct product isolation in a human melanoma and 398 pmol estrone/g protein/h by the radiometric assay. The activity present was blocked by similar amounts of the aromatase inhibitor, aminoglutethimide, as were necessary to block placental, breast cancer, and rat brain aromatase activity. We then assayed aromatase radiometrically in 19 human melanomas and found measurable activity ranging from 9 to 398 pmol estrone/g protein/h in 15 tissues. No relationship with the patient's age or sex was demonstrated. The activity exceeded by 2-fold that previously detected in 49/61 human breast cancers. This study identified a marker enzyme in melanoma tissue which varied by 40-fold among human tumors. Correlation of aromatase activity with prognosis and response to various types of therapy is now necessary to establish the biologic relevance of this finding.

Adult

Soft-tissue expansion in the lower extremities.

Soft-tissue expansion enjoys ever-wider use, but to date an experience using this technique in the lower extremity has never been presented. We reviewed our first 16 patients to describe the indications and contraindications for the use of tissue expansion in the lower extremity. Guidelines evolved from study of the data. Soft-tissue expansion merits consideration for coverage of problem wounds, in preparation for removal of large benign lesions, and for the repair of contour defects. The operator should know that an open wound below the knee predicts a complication if soft-tissue expansion is attempted in that location. In the thigh, incisions can be confidently placed at the edge of the defect. In every location, large expanders should be chosen so that they are as long as or longer than the adjacent defect. The increase in circumference of the limb should be followed. Simple designs for advancement flaps usually work well. As our experience has grown, reconstruction using soft-tissue expansion in the lower extremity has become safer and the results more predictable through better patient selection and diligent monitoring of intraluminal pressures, even if only by ensuring that the patient is always comfortable. Soft-tissue expansion has a role in reconstruction of the lower extremity.

Adolescent

Multiple trichogenic adnexal tumors.

A young girl developed multiple generalized subcutaneous nodules and two polypoid ear lesions between birth and 8 years of age. There was no family history or evidence of systemic disease. The subcutaneous nodules were trichogenic myxomas, consisting of vascular myxoid connective tissue, sometimes with islands of stratified squamous epithelium, keratinous cysts of epidermal type, or dermoid cysts with follicular and/or sebaceous differentiation. The polypoid lesions were trichofolliculomas, with areas similar to trichogenic myxomas. Our patient thus has multiple trichogenic tumors, the majority being pure hamartomas of the dermal papilla (trichogenic myxomas), others being a combined trichogenic myxoma and hamartoma of hair germ (trichofolliculoma).

Adenoma

Elimination of lymphangioma circumscriptum by suction-assisted lipectomy.

Lymphangioma circumscriptum presents as cutaneous vesicles or skin tags that drain lymphatic fluid. Deep, sequestered lymphatic cisterns encircled by smooth muscle are thought to be the cause of the skin manifestations, and selective resection of the deep cisterns, not the involved overlying skin, has been suggested as the treatment of choice. We report a successful treatment of lymphangioma circumscriptum using suction-assisted lipectomy to obliterate the deep lymphatic cisterns and their vertical channels communicating to the skin.

Adult

White House Cases: psychiatric patients and the Secret Service.

Delusional visitors to the White House or other government offices (often seeking a personal audience with the President) are interviewed by the Secret Service and then sent to Saint Elizabeths Hospital if they are considered mentally ill and potentially dangerous to themselves or others. A review of the demographic characteristics and diagnoses of 328 of these "White House Cases" treated at the hospital between 1970 and mid-1974 showed that these patients were most commonly unmarried, white, and male, and most had a diagnosis of paranoid schizophrenia. Although 22% of this group have threatened some prominent political figure, to date none of this study's patients has attempted to assassinate any such government official.

Adult

Skin expansion to eliminate large scalp defects.

In three children aged 3 to 8 years with large scalp defects temporary expanders of silicone elastomer were inserted under the scalp above the pericranium and under the galea through an incision at the junction of the defect and the normal scalp. Over the following six to eight weeks, the expanders were inflated weekly or semiweekly with injections of saline. During expansion, hair growth continued. When the scalp flap expansion was completed, the scalp margin was advanced. Two of the 3 patients required additional expansion, so a deflated expander was left under the scalp. The entire defect was covered in each case. This technique has wide application for a variety of reconstructive problems.

Child

Soft-tissue expansion: concepts and complications.

Soft-tissue expansion complements existing reconstructive techniques and provides new vistas for the plastic surgeon. The technique finds use for overcoming a shortage of tissue, for obtaining skin with special desirable qualities, for creation of flaps otherwise not possible because of the resultant donor site or limited vascularity, for creation of flaps with functioning muscle and overlying soft tissue, and for minimizing flap donor-site problems. Careful planning should include patient counseling, optimum incision placement, and time for a leisurely, complete expansion. The surgery can often be performed under local anesthesia and expansion is tolerated well. Patients should be counseled that the incidence of major complications in an unselected series is 1 in 4 patients. Major complications, however, typically result in a delay in reconstruction and not tissue loss.

Adult

Morbid obesity.

Weight loss following surgical intervention for morbid obesity leaves a redundancy of loose, amorphous skin. Contour surgery should be delayed at least one year following stabilization of weight loss to allow maximum skin contracture. If more than one procedure is contemplated, a sequence should be outlined with the patient to maximize the use of operating room time and minimize exposure to general anesthesia.

Abdomen

Wound coverage in the Achilles region.

Skin loss over the distal Achilles region regardless of cause presents a problem in reconstruction. A variety of techniques have been employed. These procedures are critically reviewed and the technique which has proven helpful at our institution is discussed. The latter procedure employs a local random pattern rotation flap which has the advantages of simplicity, brief hospitalization, predictability of success, and coverage with sensate skin that is not bulky.

Achilles Tendon

Efficacy of triamcinolone acetonide following neurorrhaphy-an electroneuromyographic evaluation.

A primate model to test the effects of triamcinolone acetonide on reinnervation after neurorrhaphy was developed. Reinnervation was assessed in triamcinolone- and placebo-treated nerves. Twelve months after neurorrhaphy, nerves treated with triamcinolone had a faster conduction velocity; a greater amplitude in the evoked response; more and larger axons distally on cross-sectional histological examination; and an evoked response wave form closely resembling normal. We conclude that triamcinolone acetonide instilled locally about a neurorrhaphy immediately after the repair is beneficial for the regeneration of motor nerves in primates.

Animals