PubMed Health⌕ Search

Biomedical subjects

G K Potter

Publications and source records attributed to G K Potter.

34 records · Page 2Linked to original sources
PubMed1985

Action of 1,25-(OH)2D3 in nude mice bearing transplantable human myelogenous leukemic cell lines.

After cyclophosphamide priming, subcutaneously (s.c.) transplanted cells from established human leukemia cell lines U937, K562, or HL-60 consistently yielded single, nonmetastatic tumors. Tumorigenesis with KG-1 cells was inconstant. Within each cell line, cytologic, electron-microscopic, cytogenetic, isoenzyme, immunochemical, and enzyme cytochemical studies confirmed identity of cultured and tumor cells. Adenosine triphosphatase reactivity was limited to leukemic cells in vivo. Isoenzyme electrophoretic patterns, distinct for each cell line, provided a reliable criterion to establish clonality and to verify tumor cell origin. Antitumor activity of the active vitamin-D3 metabolite 1,25-(OH)2D3 was assessed in vivo against U937, K562, and HL-60 cells by cell transplantation and concurrent s.c. contralateral implantation of miniosmotic pumps containing the 1,25-(OH)2D3 in a propylene glycol vehicle. Tumors developed in all treated U937 mice, 50% with K562 and 25% bearing HL-60 transplants. All transplants proliferated in mice either with pumps containing only vehicle or no pumps. Coincidence of tumor and vehicle decreased survival time. No differences in cytoreactivities or morphology were apparent between cultured cells and tumor cells in treated or untreated mice. This nude mouse system is useful for in vivo studies of human myelogenous leukemia cells. Implanted miniosmotic pumps provide controlled delivery of antineoplastic agents and their vehicles for in vivo studies. 1,25-(OH)2D3 may be a valuable adjunctive therapeutic for control of human myelogenous leukemias.

Animals↗
PubMed1984

Nude mice as models for human leukemia studies.

Human leukemic promyelocytes of the HL-60 line were grown as tumors in nude mice and studied. A single nonmetastatic granulocytic sarcoma developed after subcutaneous inoculation with HL-60 cells. Some exceeded 5 cm in size. Almost all mice developed tumors after initial priming with cyclophosphamide. Older sarcomas showed viable tumor islands in necrotic and fibrotic tissue. Some tumors appeared greenish. Histologic and electron-microscopic analysis demonstrated large, vaguely outlined cells in poorly vascularized sheets. The cells displayed high nucleocytoplasmic ratios, basophilic granular cytoplasms lacking Auer rods, and enzymes characteristic of cultured HL-60 promyelocytes. Some tumor cells also demonstrated monocyte/macrophage enzymes, such as butyrate esterase. Induced HL-60 tumors also corresponded morphologically to a human subcutaneous promyelocytic tumor specimen. Comparative cytologic studies of induced HL-60 tumors in nude mice and cultured HL-60 cells revealed virtual identity, suggesting the nude mouse tumor as a useful model for in vivo studies of human leukemic cells.

Animals↗
PubMed1982

Chondroid syringoma in a toe.

The second case of chondroid syringoma in a toe is presented. The diagnosis was confirmed microscopically, and histochemical studies suggested the presence of heavily sulfated stromal acid mucopolysaccharides. Glycogen was present only in some tumor cells. Keratin-containing tumor cells and nests were seen with polarization. This tumor should be considered in the differential diagnosis of painless, slow-growing, pedal tumors.

Diagnosis, Differential↗
PubMed1979

Keratoacanthoma: case presentation and discussion.

Keratoacanthomas are rather common, rapid growing skin tumors, in which may occur as solitary lesions or in the form of multiple lesions. Multiple forms involve the palms of soles, and their source is unclear. On area where hair grows, these lesions originate from the infundibular areas. Many environmental and traumatic influences are implicated as potential etiologic factors. Keratoacanthomas should be differentiated clinically and histologically from squamous cell carcinomas, prurigo nodularis, and chronic paronychia. Treatment varies according to the type of lesions, but solitary lesions should be excised in toto.

Diagnosis, Differential↗
PubMedDate not supplied

Dermatofibrosarcoma protuberans: 4 years after local trauma.

Dermatofibrosarcoma protuberans (DFSP) is a low grade, fibrohistiocytic malignant soft tissue tumor that arises infrequently in the foot and ankle region. It most frequently demonstrates a "storiform" histologic pattern, and if incompletely excised, may be recurrent, more anaplastic and metastatic. Soft tissue plain film radiography, as well as magnetic resonance imaging (MRI) help outline the tumor and involved tissues, which is beneficial in staging, determining surgical approach and evaluation of therapy. Definitive diagnosis is made by biopsy. A dermatofibrosarcoma protuberans is reported in the foot of a 14-year-old female patient, 4 years after trauma to the site.

Adolescent↗
PubMedDate not supplied

Delayed appearance of metastatic renal cell carcinoma subcutaneously in the left fifth toe after ipsilateral nephrectomy.

Pedal metastases from visceral cancers, while rare, constitute a consideration in the presence of an otherwise unexplained mass in the skin, subcutis, or bones of the foot. Metastatic lesions may be presenting signs of visceral malignant tumors, or may remain occult for years after extirpation of the primary visceral lesion. The presented case depicts sudden activation and growth of an occult renal cell carcinoma metastasis in the subcutaneous tissue of a 69-year-old man's left fifth toe, 10 years after ipsilateral nephrectomy. Cytogenetic studies correlate with tumor histologic patterns and help to predict heritability, uni- or bilaterality, and local and systemic biologic behavior of renal cell carcinoma, thereby aiding in prognosis and treatment planning.

Aged↗
PubMedDate not supplied

Silicone elastomer microshards in fluid from a painful metatarsophalangeal implant site. A case report.

Histopathologic studies have demonstrated microshards from silicone elastomer metatarsophalangeal joint implants in adjacent tissues in a setting of chronic inflammation and in inguinal lymph nodes. Cytologic smears of synovial fluid from symptomatic implanted joints should show these refractile, nonpolarizing microshards in the reactive inflammatory context. Nonspecific enzymatic inflammatory activity contributes to further destabilization of the implants, eventuating in symptoms and signs requiring prosthesis removal. Cytopathologic examination of aspirated fluid from the vicinity of a symptomatic implanted joint demonstrates foreign body reaction to silicone elastomer, predicting a need for intervention before the local damage is severe and disabling.

Female↗
PubMedDate not supplied

Malignant eccrine neoplasms of the foot.

Eccrine cancers are uncommon, but potentially recurrent, metastatic and fatal. Rarely, they are primary foot lesions. The literature records 46 foot cases, with age and sex given for 41. Various eccrine cancer types (most on the sole), affected all races, males predominating. Average age at diagnosis was approximately 55. A podiatric facility recorded eight cases among approximately 30,000 skin biopsies, during 15 years. Seven arose in women. Five arose in the great toe area. Three are porocarcinomas. Five are "adenocarcinomas" varying in degree of differentiation. None of the eight patients presented recurrence or metastasis during follow-up 0.5-13.4 years. Of the combined 49 literature and podiatric cases, 28 (57.1%) arose in men, mostly between ages 41 and 70. Most were slow growing, long standing, and mildly symptomatic. No clinical features distinguished eccrine cancers from other pedal tumors.

Acrospiroma↗