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Biomedical subjects

N Levine

Publications and source records attributed to N Levine.

At least 181 records · Page 10Linked to original sources
PubMed1984

Oral isotretinoin therapy. Use in a patient with multiple cutaneous squamous cell carcinomas and keratoacanthomas.

An 83-year-old woman with multiple squamous cell carcinomas and keratoacanthomas of the legs was treated with orally administered isotretinoin (13 cis-retinoic acid). Complete regression of the tumors was noted during the initial six-month treatment period. In the subsequent 36 months, four new cutaneous tumors were excised. There have been no recurrences of lesions that regressed while the patient was receiving retinoid therapy.

Administration, Oral↗
PubMed1983

High pressure liquid chromatographic detection of intracellular retinoid binding proteins from cultured cell and tumor cytosols.

We report the first application of high pressure liquid chromatography (HPLC) in the rapid detection of cellular retinoic acid binding protein (CRABP) and cellular retinol binding protein (CRBP). Cytosols from cultured cells (3T6 and MCF-7) or from tumors (melanoma and ovarian) were labeled with [3H]retinoic acid (30 Ci/mmol) and [3H]retinol (43 Ci/mmol) and analyzed via HPLC employing a 60 cm TSK 3000 sw column. In each case CRABP and CRBP were readily detectable at an elution volume of 22.5 ml, consistent with their molecular weights of 14,600. Identity of the binding protein peaks was established by saturability, specificity, and selective inhibition of binding by an organomercurial. Thus, this method, which resolves CRABP and CRBP in crude mixtures from the majority of cytosolic proteins, should be a valuable tool in the evaluation of vitamin A-binding protein interactions and their biological significance.

Animals↗
PubMed1983

Treatment of cutaneous T-cell lymphoma (mycosis fungoides) with 13-cis-retinoic acid.

Four patients with refractory cutaneous T-cell lymphoma (mycosis fungoides) were treated with 13-cis-retinoic acid. Near complete clearing of extensive tumours and plaques was seen in one patient, who remains in partial remission with continued improvement after fifteen months. Two patients showed improvement in pruritus and 50% reduction in plaques by four and six weeks, respectively. The fourth patient had improvement in pruritus and clearing of plaques, but dryness and scaling necessitated reduction and eventually withdrawal of the treatment.

Adult↗
PubMed1983

Detection of melanomas. Approach with radiolabeled false precursors of melanin synthesis.

Thiouracil is a thiol-containing pyrimidine that is selectively incorporated into cells that synthesize melanin. In an effort to delineate further the specificity and dynamics of uptake, we injected thiouracil labeled with radioactive carbon into S91 melanoma-bearing mice; biopsy specimens were taken of the tumors and organs at various time intervals thereafter. The data showed a substantial uptake of thiouracil by the melanomas, with peak uptake occurring at 24 hours. All other organs examined showed only minor amounts of radioactivity, which probably reflected the presence of thiouracil in the blood perfusing these tissues. Because of its incorporation into melanomas, the use of radioactive thiouracil has potential as a marker for tumor growth, as a diagnostic tracer compound, and as a carrier for chemotherapeutic agents.

Animals↗
PubMed1983

Hyperthermic treatment of cutaneous malignancies.

Malignant cells are susceptible to high temperatures, and recent technical advances have allowed heat to be concentrated at the site of the neoplasm in vivo. The mechanism(s) of hyperthermic cytotoxicity is(are) unclear but may involve cellular accumulation of nuclear proteins, plasma membrane damage, and/or lysosomal effects. Three methods of localized hyperthermia delivery have been described: ultrasound, radiofrequency, and microwave. All involve production of high-energy save forms which are produced by passing electrical energy through an oscillator that produces heat of sufficient magnitude to cause tumor necrosis. Temperatures of at least 42 degrees C are necessary, but other factors, such as tissue pH, metabolic depletion, tissue hypoxia, and tumor vascularity, also influence cell killing. Hyperthermic treatment of cutaneous neoplasms may have great potential usefulness. Animal studies show high cure rates for squamous cell carcinoma with the use of radiofrequency hyperthermia. Human trials are needed before this technic can be considered suitable for clinical use.

Animals↗
PubMed1982

Animal model of intracutaneous melanoma.

An animal model which allows for the implantation and development of intracutaneous melanoma is described. Intradermal vesicles are created by a negative pressure apparatus in DBA/2J mice. S91 melanoma cells are injected into the blister cavities. Tumor growth occurs within 7 days and the yield approaches 100%. This model is a rapid, efficient, and applicable system for the study of melanoma growth dynamics and of the effects of systemic and topical anti-tumor agents on melanoma proliferation.

Animals↗
PubMed1982

Cutaneous granulomatosis in Crohn's disease.

A 36-old-man who had Crohn's disease of the distal part of the colon developed widespread cutaneous lesions that, on histologic examination, showed the same type of granuloma formation found in the affected bowel. Other skin manifestations of Crohn's disease are reviewed.

Adult↗
PubMed1981

Atypical familial benign chronic pemphigus.

Two patients with atypical features of familial benign chronic pemphigus (FBCP) are presented herein. One patient had lesions limited to the anterior chest and the other had lesions localized to the lateral arms. Neither patient had prominent intertriginous involvement. These cases illustrate the protean manifestations of this disease.

Adult↗
PubMed1980

Topical vitamin-A-acid therapy for cutaneous metastatic melanoma.

Two patients with cutaneous metastatic melanoma were treated with a topical retinoid, beta-all-trans-retinoic acid. Complete regression of the treated lesions was noted in one patient and a partial response was seen in the other patient. The mechanism of anti-tumour action of the retinoids is not completely known but binding to intracytoplasmic receptors with promotion of cellular differentiation, alteration of membranes, and immunological adjuvant effects may be involved.

Administration, Topical↗
PubMed1980

Dermatologic aspects of sports medicine.

The skin lies at the interface of the athlete and the sports milieu and is subjected to many sports-related dermatoses. Direct traumatic injuries, such as friction blisters, black heel, piezogenic papules, and traumatic subungual hematomas, occur regularly. Environmental insults such as sunburn, cold-induced injury, and contact dermatitis plague the sportsman. Cutaneous infections such as "athlete's foot," otitis externa, herpes simplex, and warts occur because of a favorable microenvironment, occurring with sweating and occlusion as well as close interpersonal contact. Sports participation may uncover or exacerbate latent dermatoses such as occurs in acne mechanica and exercise-induced anaphylaxis. The sportsman is best served if the physician considers him as an athlete-patient.

Athletic Injuries↗
PubMed1980

Control of reabsorption of water and electrolytes by guinea-pig seminal vesicle in vivo.

Guinea-pig seminal vesicles reabsorbed Na+ and K+ in vivo from a standard bicarbonate buffer against both electrical and chemical gradients. Water was reabsorbed with the ions. Concentrations of Na+ and K+ in the reabsorbate were greater than in plasma or the initial buffer perfusate. Guinea-pigs castrated for 6 days did not reabsorb water or electrolytes, but daily administration of testosterone or 5 alpha-dihydrotestosterone restored normal reabsorption rates. Addition of prostaglandin E-2 to the perfusate inhibited water and Na+ reabsorption. Section of the hypogastric nerve did not affect reabsorption rates measured 10 days later. We suggest that the guinea-pig seminal vesicle maintains a basal reabsorptive capacity to remove electrolytes and water that diffuse or are secreted into the lumen and that the reabsorptive pump may be coupled to a secretory one activated intermittently and perhaps partly modulated by prostaglandins.

Absorption↗