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Biomedical subjects

G K Potter

Publications and source records attributed to G K Potter.

At least 19 recordsLinked to original sources
PubMed2000

Progressive pedal macrodactyly surgical history with 15 year follow-up.

Macrodactyly can affect the fingers and/or toes1. Histopathologic examination will distinguish macrodactylia fibrolipomatosis or neural fibrolipoma with macrodactyly, from macrodactylia as a part of neurofibromatosis. Surgical repair is aimed at decreasing the size of the affected foot so it is as near in size and shape to the normal foot as possible. Surgical approaches have included reconstructive surgery (usually staged debulking procedures), epiphyseal plate arrest and amputation. Repeated reconstructive surgical procedures, as illustrated in this report covering patient care over a 15 year period, are usually necessary due to recurring soft tissue and boney enlargement.

Adult↗
PubMed1998

Review and consideration of coagulopathies.

Blood components bring nutrients to the tissues, remove wastes, provide defenses against microorganisms and foreign bodies, and retain sufficient fluidity to keep the system functioning properly. Coagulation factors are also present in the blood as part of a sensitive system that stems the flow of blood from a wound and maintains homeostasis. These factors include anuclear platelets that originate from megakaryocytes in the bone marrow, as well as soluble factors in precursor form, and calcium ion. Faults in single or multiple parts of this system, which can be determined in the patient's history, may result in bleeding problems that may be clinically relevant. Clarification of coagulation defects requires cooperation with a hematologist before medication that affects the coagulation system is prescribed or before any procedures that may result in bleeding are undertaken.

Blood Coagulation Disorders↗
PubMed1998

Considerations in the treatment of patients with renal disease.

Renal function includes maintenance of fluid pH, electrolyte and fluid balance, influence on blood pressure, excretion of fluid and metabolic soluble wastes after filtration or reabsorption, and production of erythrocyte stimulating factor and the active form of vitamin D. These processes involve sensory mechanisms in the kidney, as well as the ability to respond to sensed changes, to maintain body homeostasis. Decrease in or failure of renal function induces abnormalities in many other systems, requiring a modified approach that is individual to each patient, and includes alteration of medications used and a re-evaluation of their doses. Some patients may require a regimen of dialysis or eventual renal transplantation, each with attendant advantages and risks. Careful evaluation and consultation with a nephrologist is required when local or systemic treatment is contemplated.

Diuretics↗
PubMed1996

Metastatic endometrial adenocarcinoma to the skin of a toe.

A 55-year-old woman had a history of prolonged vaginal bleeding. Dilatation and curettage confirmed poorly differentiated endometrial adenocarcinoma. After hysterectomy, salpingo-oophorectomy, and 5,040 cGy of postoperative irradiation, lung metastases developed, which temporarily responded to chemotherapy that included adriamycin and cisplatin. Metastatic lesions developed later in the left acetabulum and the hallux. The latter, clinically reminiscent of pyogenic granuloma, affected only skin. The poorly differentiated toe metastasis duplicated areas of the primary endometrial adenocarcinoma and was immunohistochemically similar to it. While appearing quite rarely, and generally late in the disease, pedal skin lesions may represent metastases from known or occult visceral cancers.

Adenocarcinoma↗
PubMed1996

Primary and metastatic malignant tumors in soft tissue of skin. Diagnostic, surgical, and prognostic considerations for the foot.

Benign and malignant soft-tissue tumors are those that arise from mesenchymal (and some neuroectodermal) nonosteogenic and nonchondrogenic cells. The various primary malignant tumors are sarcomas with invasive and metastatic potential and are the same types that arise in the deeper tissues. In addition to sarcomas that arise directly in the dermis or subcutis, these tissue areas may be invaded by sarcomas from the deeper structures and by carcinomas and sarcomas metastatic to the skin. Dermal or subcutaneous cancers may appear clinically nondescript but are nonetheless dangerous, requiring an appropriately considered biopsy for identification and subsequent planning of patient care.

Carcinoma↗
PubMed1995

Neoplasia in the toes and toenail areas.

Benign and malignant tumors as well as pseudotumors occur in the toes. The toenail areas may also be involved primarily or secondarily. All tissues in the toes can give rise to tumors. Occasionally, metastatic tumors from the viscera manifest in the toes. New or recurrent masses should be subjected to biopsy, as should lesions that do not respond to treatment based on an initial clinical impression.

Bone Neoplasms↗
PubMed1994

Intraosseous chondroid syringoma of the hallux.

A 25-year-old black woman had a deformed right great toe. X-ray examination revealed extensive lytic change in the distal phalanx, to which technetium uptake was limited. The amputation specimen revealed a benign chondroid syringoma in the subungual tissue that penetrated and permeated the bone. Chondroid syringoma is rare in the foot, and we present what we believe is the first such immunohistochemically confirmed case involving bone.

Adenoma, Pleomorphic↗
PubMed1993

Evaluation of a patient for pedal neoplasia. Basic principles and procedures.

The process of determining a diagnosis for a patient with a tumor mass is not easy. It demands astuteness on the part of the attending doctor as well as cooperative consultation and teamwork with radiologists, pathologists, and other specialists. It also demands a basic understanding of the characteristics of benign and malignant tumors in the foot, whether primary or metastatic. This is best accomplished by continued reading of a variety of journals and current texts as well as by attendance at clinical conferences. Concern for the patient must motivate any practitioner to know, understand, and undertake definitive diagnostic procedures to determine the nature and extent of a neoplasm. The practitioner must acquire and maintain an appropriately high index of suspicion and an awareness that the foot can be the site of a primary or metastatic tumor.

Biopsy↗
PubMed1990

Neoplasms of the peripheral nervous system.

Neoplasms of the peripheral nervous system arise from the cellular sheath surrounding the nerve trunks, that is, the pluripotential Schwann cells and related cells, and rarely affect the feet. When present, they are most frequently associated with the autosomal dominantly inherited neurofibromatosis 1. This condition has been related to chromosome 17, and it appears, from in vitro experiments, to involve defects in tyrosine metabolism. Hence, the most common neoplasm is the neurofibroma. Distinct criteria have been established for a diagnosis of neurofibromatosis 1, so that a single pedal neurofibroma may not represent this complex. However, if the complex is present, it is necessary to consider the possibility of malignant transformation to a neurofibrosarcoma. Although malignant peripheral nerve neoplasms are extremely rare in the feet, they may arise in the context of neurofibromatosis 1, or independently. Other benign or malignant schwannomas may (rarely) also arise in the feet. Surgical excision of benign lesions, according to established standards for tumor surgery, is usually curative, but a detailed personal and familial history, along with adjunctive radiologic procedures and biopsy, is necessary to determine the nature of the lesion. Since (endocrine and) other abnormalities may complicate neurofibromatosis 1, surgical procedures must not be undertaken until the patient has been medically cleared and is carefully monitored. A high mortality rate is associated with malignant peripheral neurogenic tumors, especially those arising in the context of neurofibromatosis 1. It should be recalled that neurologic manifestations in the foot may represent non-neoplastic conditions as well as peripheral nerve tumors (or other tumors involving those nerves) that are proximal to the foot and ankle area.

Adult↗
PubMed1989

Presence of tumour necrosis factor or a related factor in human basophil/mast cells.

The observation that mast cell products and cachectin/tumour necrosis factor (TNF) mediate similar responses suggested an investigation of cultured human basophil/mast cells for production of TNF. Using in situ hybridization and the avidin biotin-complex (ABC) immunoperoxidase method, we have demonstrated the presence of TNF mRNA in the cytoplasm and TNF protein in the granules of individual human basophil/mast cells. The production of TNF by these cells could explain many of their reported functions.

Basophils↗
PubMed1987

Recombinant human granulocyte colony-stimulating factor. Effects on hematopoiesis in normal and cyclophosphamide-treated primates.

We examined the in vivo effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in primates (cynomolgus monkeys) treated with subcutaneous doses of rhG-CSF for 14-28 d. A dose-dependent increase in the peripheral white blood cells (WBC) was seen, reaching a plateau after 1 wk of rhG-CSF treatment. The elevation of WBC was due to an increase in the absolute neutrophil count. These results demonstrate that rhG-CSF is a potent granulopoietic growth and differentiation factor in vivo. In cyclophosphamide (CY)-induced myelosuppression, rhG-CSF was able to shorten the time period of WBC recovery in two treated monkeys to 1 wk, as compared to more than 4 wk for the control monkey. Its ability to significantly shorten the period of chemotherapy-induced bone marrow hypoplasia may allow clinicians to increase the frequency or dosage of chemotherapeutic agents. In addition, the increase in absolute numbers of functionally active neutrophils may have a profound effect in the rate and severity of neutropenia-related sepsis. Furthermore, the activities reported here indicate a potential role for rhG-CSF in the treatment of patients with myelodysplastic syndrome, congenital agranulocytosis, radiation-induced myelosuppression, and bone marrow transplantation.

Animals↗
PubMed1987

Recombinant human granulocyte-colony stimulating factor: in vitro and in vivo effects on myelopoiesis.

The results presented in this paper demonstrate that recombinant human granulocyte-colony stimulating factor (rhG-CSF) is a potent myelopoietic growth and differentiation factor in vivo. RhG-CSF was able to shorten the time period of neutrophil recovery in both cyclophosphamide (CY)-induced myelosuppression and following bone marrow transplantation (BMT) in primates. Its ability to significantly shorten the period of chemotherapy-induced bone marrow hypoplasia may allow clinicians to increase the frequency or dosage of chemotherapeutic agents. In addition, the increase in absolute numbers of functionally active neutrophils may have a profound effect on the rate and severity of neutropenia-related sepsis. Furthermore, the activities reported here indicate a potential role for rhG-CSF in the treatment of patients with myelodysplastic syndrome, congenital agranulocytosis, radiation-induced myelosuppression, and after bone marrow transplantation.

Animals↗
PubMed1985

Colonization of nonmelanocytic cutaneous lesions by dendritic melanocytic cells: a simulant of acral-lentiginous (palmar-plantar-subungual-mucosal) melanoma.

Four cases of colonization of nonmelanocytic lesions by dendritic melanocytic cells are reported, one in a verruca vulgaris of the lip, one in a squamous cell carcinoma in situ of mucous membrane overlying a tonsil, one in a lesion of lichen simplex chronicus with a nevocellular nevus of the external ear, and one in a dermatofibrosarcoma protuberans (Bednar tumor). This is an important biological process of melanocytes that must not be confused with the acral-lentiginous (palmar-plantar-subungual-mucosal (P-S-M) melanoma. It is probably much more common than the paucity of published reports would indicate.

Adult↗