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Biomedical subjects

R G Phelps

Publications and source records attributed to R G Phelps.

At least 55 records · Page 3Linked to original sources
PubMed1992

Case report: myiasis--the botfly boil.

Cutaneous furunculoid myiasis arises from the infestation of skin or mucous membranes with dipterous larvae. Myiasis from the botfly Dermatobia hominis is a common parasitic disease of the tropics of Central and South America, and may present in the United States. With increasing travel by U.S. citizens, there is potential for increased occurrence; it is important to be able to accurately diagnose myiasis and differentiate it from entities with similar presentations, such as leishmaniasis. The authors describe four cases of myiasis from D. hominis infestation and review clinical features, differential diagnosis, and treatment.

Adult↗
PubMed1991

Regional variation in the expression of pemphigus foliaceus, pemphigus erythematosus, and pemphigus vulgaris antigens in human skin.

The expression of the pemphigus foliaceus (PF), pemphigus erythematosus (PE), and pemphigus vulgaris (PV) antigens in 16 different regions of normal human skin was evaluated by indirect immunofluorescence by using sera with a high titer of PF, PE, and PV antibodies. Regional variations were observed in the expression of all these antigens. The expression of the PF and PE antigens, as measured by endpoint titer of antibody reactivity, was highest in skin specimens obtained from the upper torso, and lowest in those from the buccal mucosa, lower torso, and scalp. This distribution pattern differed from that of PV antigen, whose expression was highest in buccal mucosa and scalp. These patterns correlate with, and may provide a partial explanation for, the different distribution of skin lesions in these different forms of pemphigus.

Antigens, Surface↗
PubMed1991

Acanthosis Nigricans, insulin action, and hyperandrogenism: clinical, histological, and biochemical findings.

Acanthosis nigricans (AN) is a frequent clinical finding in hyperandrogenic women. Its presence has been used to subgroup such women. We performed this study in order to determine the actual histological prevalence of AN and its relationship to sex hormone levels and insulin action. Insulin-mediated glucose disposal was determined by the euglycemic clamp technique, and neck or axillary skin biopsies were graded blind for the presence and severity of AN in lean and obese women with the polycystic ovary syndrome (PCO) and in age- and weight-matched normal ovulatory controls. AN was present on clinical examination in 11 of 13 obese PCO, 3 of 6 lean PCO, 4 of 14 obese normal, and 0 of 4 lean normal women. AN was present on histological examination in 13 of 13 obese PCO, 5 of 6 lean PCO, 13 of 14 obese normal, and 1 of 4 lean normal women. The severity of histological AN was most highly correlated with insulin-mediated glucose disposal (r = -0.61; P less than 0.001) rather than fasting (r = 0.46; P less than 0.05) or glucose-stimulated insulin levels (r = 0.48; P less than 0.01). The only sex steroid correlated with histological AN was dehydroepiandrosterone sulfate (r = 0.46; P less than 0.01). We conclude that 1) clinical skin examination was very insensitive for detecting AN; 2) the best biochemical correlate of histological AN was decreased insulin action, rather than insulin or androgen levels per se; and 3) AN is a very common epiphenomenon of insulin resistance, and its clinical presence should not be used as a criterion for stratifying hyperandrogenic women.

Acanthosis Nigricans↗
PubMed1991

Eosinophilic fasciitis associated with tryptophan ingestion. A manifestation of eosinophilia-myalgia syndrome.

Recently, the ingestion of tryptophan has been associated with eosinophilia-myalgia syndrome, which is characterized by eosinophilia, myalgias, and several less consistently reported findings. We treated 13 patients who exhibited clinical features of eosinophilic fasciitis who were taking high-dose tryptophan before the onset of clinical symptoms. Twelve patients exhibited eosinophilia, with eosinophil counts ranging from 0.13 to 0.88. The remaining patient was taking oral corticosteroids when her eosinophil count was determined. Eight patients complained of myalgias. Other symptoms included arthralgias, pruritus, cutaneous burning, weakness, fever, rashes, malaise, edema, muscle spasms, and alopecia. 5-Hydroxyindoleacetic acid levels were elevated in four of the eight urine specimens that were tested. Our findings suggest that previously diagnosed cases of eosinophilic fasciitis may represent variants of tryptophan-associated eosinophilia-myalgia syndrome. Derangements in the metabolism of tryptophan may play a role in sclerotic diseases.

Adult↗
PubMed1990

Pulmonary carcinoid presenting as multiple subcutaneous nodules.

A 60-year-old female presented with a one-year history of multiple enlarging tender subcutaneous nodules. Initial biopsy demonstrated a poorly differentiated adenocarcinoma. Mammography showed multiple nodular breast lesions. After the patient failed to respond to tamoxifen, a second biopsy demonstrated a metastatic carcinoid tumor. Further search revealed a single small pulmonary nodule, which on aspiration biopsy proved to be a carcinoid tumor. The patient failed to respond to treatment with streptozotocin and 5'-fluorouracil. Therapy with leucovorin calcium and 5'-fluorouracil then produced a partial response.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Lymphomatoid papulosis with antigen deletion and clonal rearrangement in a 4-year-old boy.

Lymphomatoid papulosis (LyP) is rarely seen in children. We report a case of LyP in a 4-year-old boy in whom immunopathologic studies demonstrated T cell antigen deletions. In contrast to all but two previous reports, a T suppressor (CD-8) phenotype was predominant. Southern blot analysis of DNA isolated from a typical skin lesion indicated a clonal rearrangement of the T cell receptor beta gene. Because of a 10% frequency of malignant lymphomas in patients with LyP, long-term observation is crucial, especially in children. We recommend routine clonal rearrangement studies for aid in diagnosis and follow-up, and as possible prognostic indicators in children with this condition.

Antigens, CD↗
PubMed1989

Immunofluorescence and electron microscopic findings in a congenital arrector pili hamartoma.

A congenital arrector pili hamartoma is a neoplasm that presents as multiple or solitary dermal nodules in a dermatomal distribution. To elucidate and clarify its histogenesis, a lesion derived from a 3-year-old boy was studied by light microscopy, indirect immunofluorescence, using antibodies against basal lamina constituents and against interstitial matrix components, and electron microscopy. In addition, a rabbit antibody specific for bovine smooth-muscle myosin was used. The antibodies against the basal lamina components and fibronectin all showed an intense perimysial fluorescence that ensheathed and surrounded individual leiomyocytes. Anti-smooth-muscle myosin exhibited intense cytoplasmic fluorescence. Furthermore, electron microscopy showed fusiform cells with abundant myofilaments, dense bodies, and pericellular basal lamina as seen in smooth muscle. These studies suggest the probable origin of this hamartoma from pili arrector muscle and could be used as an adjunct in histopathological diagnosis.

Child, Preschool↗
PubMed1989

Characterization of a dermal derived malignant mesenchymal tumor arising in ultraviolet irradiated mice.

Skh/hr-1 hairless albino mice were irradiated with photocarcinogenic dosages of ultraviolet light for periods of 30 weeks or longer. A high proportion of mice developed pleomorphic spindle cell tumors and epidermal neoplasms of various types. These spindle cell tumors were studied by immunofluorescence and immunoperoxidase techniques and by electron microscopy. Freshly isolated tumor cells were grown in tissue culture. Immunocytochemical analysis showed varying expression of markers of mesenchymal differentiation: vimentin, procollagens I and III, type I collagen, and lysozyme. Electron microscopy showed spindled and cuboidal cells with abundant endoplasmic reticulum, filopodia, and lysosomes, but no intercellular connections. The cells grown in vitro were cuboidal and stellate and also showed mesenchymal differentiation by electron microscopy. These results are perhaps similar to those described for a human actinically produced fibrohistiocytic neoplasm, atypical fibroxanthoma, and this system may provide a useful model of ultraviolet-induced dermal neoplasia.

Animals↗
PubMed1988

Clinical, pathologic, and immunopathologic manifestations of the toxic oil syndrome. Analysis of fourteen cases.

The clinical, pathologic, and immunopathologic findings of 14 patients with the toxic oil syndrome are presented. The toxic oil syndrome occurred in Madrid, Spain, as a consequence of ingestion of an industrial oil sold as olive oil. The syndrome occurred in two phases. In the acute phase patients developed an interstitial pneumonitis, fever, and exanthem, and some died of respiratory insufficiency. Of those who survived, some developed a chronic phase with a neuromyopathic and scleroderma-like illness that had many features of a collagen vascular disease. Histologic examination of lung in the acute phase showed an endovasculitis and features of adult respiratory distress syndrome. In the chronic phase the skin showed various degrees of sclerodermoid changes and vessel injury. Immunofluorescence with antiprocollagen and antifibronectin antibodies revealed abundant perivascular fluorescence suggestive of vascular injury. Electron microscopy corroborated this by the presence of endothelial swelling and basal lamina reduplication. Similar findings have been described in systemic sclerosis, and this provides an important model for study of connective tissue disease, including scleroderma.

Adolescent↗
PubMed1987

Diagnosis of pseudoxanthoma elasticum by scar biopsy in patients without characteristic skin lesions.

Pseudoxanthoma elasticum is a disorder of connective tissue that is associated with numerous systemic complications, including accelerated atherosclerosis, gastrointestinal bleeding, angioid streaks in the ocular fundus, and blindness. Diagnosis of the disease is important because many of its complications can be prevented and genetic counseling can be offered to family members of affected patients. The purpose of this study was to examine the usefulness of scar biopsy in establishing a diagnosis of pseudoxanthoma elasticum in patients with angioid streaks but without characteristic skin lesions. Ten patients with angioid streaks but without cutaneous findings indicative of pseudoxanthoma elasticum were evaluated by biopsy of scars and flexural skin. The biopsy specimens were compared with those from unaffected controls. In 6 of the 10 patients, scar biopsies showed fragmentation and clumping of elastic tissue in the deep dermis. Three patients also had these histologic features of pseudoxanthoma elasticum in biopsy specimens of flexural skin that appeared to be normal. We conclude that biopsies of scars in randomly chosen sites may be useful when pseudoxanthoma elasticum is suspected despite the absence of typical skin lesions.

Adult↗
PubMed1987

Subcutaneous fat necrosis of the newborn with hypercalcemia.

A newborn infant with subcutaneous fat necrosis and hypercalcemia is presented. Literature on the association between subcutaneous fat necrosis of the newborn and hypercalcemia is reviewed. Affected infants generally experience severe perinatal difficulties. Both vaginal deliveries and cesarean sections can be associated with subcutaneous fat necrosis.

Adipose Tissue↗
PubMed1987

Multiple hamartoma syndrome.

Multiple hamartoma syndrome, also known as Cowden's disease, is a rare genodermatosis with multiple organ system involvement affecting tissues derived from ectodermal, endodermal, and mesodermal tissue layers. We describe two previously unreported cases of multiple hamartoma syndrome in a father and daughter. Both show classic features of multiple hamartoma syndrome, as well as other mucocutaneous findings. The father has been shown to have substantial cutaneous deposits of amyloid in the absence of underlying plasma cell dyscrasia or malignancy. Both individuals have undergone excision of a unique fibroma that has features that have been reported only in multiple hamartoma syndrome and should be added to the criteria used to define the entity.

Adolescent↗
PubMed1986

Eosinophilic pustular folliculitis.

We present the case of an American adult patient with eosinophilic pustular folliculitis. The majority of previously reported patients have been Japanese. Eosinophilic pustular folliculitis is a rare condition characterized by recurrent, peripherally expanding, sterile papulopustules and plaques. Hair-bearing areas such as the face, chest, back, and extensor surfaces of the upper arms are usually involved, although palms and soles can be affected as well. Histologic examination shows subcorneal and intrafollicular abscesses and spongiosis of the outer root sheath. The eosinophil is a prominent infiltrating cell, although mononuclear cells and neutrophils may also be seen. There is often a dense perivascular infiltrate of eosinophils in the dermis. Our patient was unusual in that he did not respond to multiple therapeutic regimens.

Adult↗
PubMed1985

The carboxyl fragment released by bacterial collagenase from human type I procollagen: antibodies to the propeptide determinants.

A protocol is offered for the isolation of the carboxyterminal propeptides of human type I procollagen and the development of an antibody specific for these propeptides. Type I procollagen was harvested from the media of cultured human fibroblasts. Digestion with bacterial collagenase released a carboxyterminal fragment that was isolated by ion-exchange chromatography. The fragment contained telopeptides joined to propeptides and could be cleaved by a carboxyl procollagen peptidase. Rabbit antibodies raised to the collagenase-generated fragment were sequentially adsorbed on affinity columns of the reference antigen and human type I collagen. The antibody obtained was shown by sensitive radioimmunoassays to recognize conformational carboxyl propeptide determinants and not to react with triple helical and telopeptide determinants of human type I collagen. Indirect immunofluorescence and indirect immunoperoxidase staining of cultured fibroblasts localized the antigen in the cytoplasm, at the cell surface, and in the extracellular matrix. A radioimmunoassay with the same antibody has reported altered concentrations of the antigen in the sera of patients with diseases affecting collagen metabolism (Taubman, et al., 1976; Savolainen et al., 1984; Carey et al., 1985).

Animals↗