Search PubMed⌕ Search

Biomedical subjects

D E Sweet

Publications and source records attributed to D E Sweet.

At least 19 recordsLinked to original sources
PubMed1992

Asymptomatic HIV infection. A primary care disease.

Asymptomatic human immunodeficiency virus infection is a disease entering the primary care arena more and more frequently. Patients may be monitored in this setting until complications and clinical deterioration develop (typically after several years). As the disease progresses, referral to consultants who specialize in AIDS may be appropriate. However, many patients do not live near a major healthcare center and do not have the financial, physical, or emotional capability to travel to one as they become sicker. In these cases, primary care physicians, with the aid of a personally chosen network of specialized consultants, should offer care as the disease progresses to its terminal stage.

AIDS-Related Opportunistic Infections↗
PubMed1992

Cortical osteofibrous dysplasia of long bone and its relationship to adamantinoma. A clinicopathologic study of 30 cases.

Thirty cases of cortical osteofibrous dysplasia (COFD) were studied in an attempt at defining the relationship of COFD to adamantinoma. The patients ranged in age from newborn to 39 years (mean 13.4 years). The male:female ratio was 1:1. Presenting symptoms were most often pain or a mass. The tibia was involved in all 30 patients; in addition, the ipsilateral fibula was involved in five patients (17%). The histologic appearance of the lesions was dominated by the combination of woven bone trabeculae with prominent osteoblastic rimming and a loose, slightly myxoid stroma (less heavily collagenized in most instances than usually encountered in intramedullary fibrous dysplasia). Results of immunohistochemical study showed isolated cytokeratin-positive cells in the stroma of 28 of the lesions (93%). However, hyperchromatic epithelial islands characteristic of adamantinoma were not found in any of the 30 cases. A control population of 50 fibro-osseous lesions (intramedullary fibrous dysplasia, sclerosing fibroxanthoma, and cranial ossifying fibroma) was studied immunohistochemically; in none of these control cases were cytokeratin-positive cells found. Follow-up data were obtained in 17 cases (57%); the period ranged from 1 to 16 years (mean 6.05 years). Certain overlapping clinical features (including the location of the vast majority of the lesions in the tibia and, less often, the fibula) and the morphologic similarities of many areas of COFD and adamantinoma (particularly the shared presence of cytokeratin-positive cells) suggest a more than coincidental association between COFD and a adamantinoma. However, to date none of the 30 cases of COFD evaluated in this study has developed an adamantinoma.

Adolescent↗
PubMed1992

Giant cell tumor in skeletally immature patients.

The radiographs and clinical and surgical histories of 50 skeletally immature patients with histologically verified giant cell tumor (GCT) of the long and short tubular bones were retrospectively studied to determine the prevalence, location within bone (eg, epiphysis, metaphysis), skeletal distribution, radiographic appearance, and pathogenesis of GCTs. Skeletal immaturity was determined radiographically by the presence of open epiphyses. Patients were selected from a group of 876 patients who were seen in consultation with documented GCT of the tubular bones. Approximately 5.7% of all GCTs occurred in the skeletally immature (this rate must be viewed with caution due to the selection bias inherent in any referral population). The lesions almost invariably involved the metaphysis. The tibia was the most commonly affected site, representing approximately 26% of cases. All were geographic lytic lesions, with margins ranging from sclerotic to ill defined. An expanded (widened), remodeled bone contour was frequently encountered. Approximately 56% of lesions were solid or solid with cystic change; the remaining 44% were predominantly cystic.

Adolescent↗
PubMed1992

Parosteal lipomas: a new perspective.

Parosteal lipomas, benign adipose tissue tumors situated directly on bone cortex, are unusual neoplasms that appear to emerge from multidirectional mesenchymal "modulation" within the periosteum. These tumors have been described as "periosteal lipomas", "chondrolipomas of soft tissue" and "lipomas of nerves" but they are most commonly believed to originate from the periosteum. Although over 100 of such tumors have been described in the literature, they have not been the subject of a comprehensive review, nor their potential for chondroid modulation and enchondral ossification emphasized. A review of 14 parosteal lipomas from the Bone Tumor Registry, Armed Forces Institute of Pathology, indicates these tumors are frequently associated with chondroid and/or osseous modulation, which permits subclassification into 4 distinct variants. Each of the 4 subtypes (I: No Ossification; II: Pedunculated Exostosis; III: Sessile Exostosis; IV: Patchy Chondro-Osseous Modulation) is illustrated to demonstrate the morphologic basis for radiologic/pathologic correlation and subclassification. A brief overview of the literature and pathogenesis of this unusual lesion is presented and discussed.

Aged↗
PubMed1991

A histomorphologic and immunohistochemical study of chordoma in twenty ferrets (Mustela putorius furo).

The histomorphologic and immunohistochemical features of chordoma in 20 ferrets were evaluated. The mean age was 3.4 years, and, in the cases for which sex was known, females (n = 10) outnumbered males (n = 5) two to one. All 20 tumors occurred on the tip of the tail. Nineteen of 20 tumors (95%) were composed of three tissue components, often arranged concentrically with lobules of physaliferous cells at the periphery, trabecular bone in the center, and cartilage in between. The bone often contained marrow and hematopoietic cells. One tumor lacked chondromatous or osseous tissue. Immunohistochemical results were consistent with previous studies of chordoma. All 20 tumors (100%) were positive for keratin and vimentin intermediate filaments; 15 (75%) were positive for S-100 protein; and 17 (85%) were positive for neuron specific enolase. This neoplasm shares morphologic and immunohistochemical features with "classic," as well as chondroid chordoma, of human beings, making it a potential animal model.

Animals↗
PubMed1991

John Caffey Award paper. Avascular necrosis: early MR imaging and histologic findings in a canine model.

To examine the early MR and histologic changes of avascular necrosis, we surgically devascularized the distal femur of adult beagle dogs and performed short TR/short TE MR imaging and histologic examinations. MR showed increasing areas of low signal, and histologic examination showed changes of fat necrosis, inflammatory infiltrate, and fibrocytic and bony repair. These processes were divided into four stages. Stage 1 is seen in the first days after surgery and consists of homogeneous high signal on MR and only subtle histologic changes of early fat necrosis. Stage 2, seen by 7 days after surgery, shows linear low-signal areas within the high-signal marrow on MR and fat necrosis and an inflammatory infiltrate on histologic sections. Stage 3, seen by 16 days after surgery, shows patchy low signal occupying more of the marrow on MR with a fibrocytic infiltrate on histologic sections. Stage 4, seen by 23 days after surgery, shows a more homogeneous low and intermediate signal on MR and histologic findings of more organized fibrocytes and the onset of new bone formation. Using this model, we have proved that MR imaging can show marrow changes as soon as 1 week after the onset of avascular necrosis. Whereas MR imaging showed a progression of increasing areas of low signal, the histologic findings seen during this time were diverse, including inflammatory infiltration (a previously unreported finding), fat necrosis, and fibrocytic and osseous repair.

Animals↗
PubMed1991

Well-differentiated extraskeletal osteosarcoma. A soft-tissue homologue of parosteal osteosarcoma.

We describe a unique case of a low-grade extraskeletal osteosarcoma revealing both histologic and radiologic features reminiscent of parosteal osteosarcoma. The tumor, which had been present for 10 years, occurred in the left axilla of a 74-year-old black woman. To date, all the published cases of extraskeletal osteosarcoma have been high-grade neoplasms; to our knowledge, this is the first reported case of a low-grade extraskeletal osteosarcoma.

Aged↗
PubMed1977

Fat-cell changes as a mechanism of avascular necrosis of the femoral head in cortisone-treated rabbits.

Large doses of cortisone were given to growing and adult rabbits over a five-month period to produce avascular necrosis of the femoral head. The cortisone caused an increase in the serum cholesterol, fatty metamorphosis of the liver, and fat emboli visible in sections of the femur and humerus. These emboli partially obliterated the microcirculation of the subchondral vessels of both femoral and humeral heads. The average diameter of the marrow fat cells also increased more than ten micrometers. This increase in cell volume might be significant because in the closed chamber of the femoral head it could increase tissue pressure, diminish perfusion, and be the mechanism for avascular necrosis induced by cortisone.

Animals↗
PubMed1976

Malignant fibrous xanthoma with metastasis to cerebellopontine angle.

Malignant fibrous xanthoma is an uncommon tumor of histiocytic origin. It is a difficult tumor to diagnose, and may have an unpredictable and confusing clinical course. The malignant fibrous xanthoma described herein probably represents the first reported case of metastasis to the cerebellopontine angle. When properly diagnosed, the preferred treatment is wide excision. Metastases are usually to the lungs and regional lymph nodes, and portend a poor prognosis. Radiotherapy appears to be of little value.

Cerebellar Neoplasms↗
PubMed1976

Avascular necrosis in SLE. An apparent predilection for young patients.

Recent reports of avascular necrosis (AN) in systemic lupus erythematosus (SLE) have suggested that its occurrence may be most frequent in young patients. In our population of 99 patients with SLE, 7 young patients have developed AN. Patterns of prednisone therapy had no apparent relationship to the development of AN. AN may become apparent in patients who have relatively inactive lupus, when increased physical activity precipitates articular collapse. A diagnosis of AN should be considered in young patients with localized joint pain.

Adolescent↗
PubMed1976

Ewing's sarcoma.

Explore the source record for details and available documents.

Diagnosis, Differential↗
PubMed1975

Angiography in the diagnosis of osteoid-osteoma of the hand.

Angiographic findings characteristic of osteoid-osteoma are described in two cases of osteoid-osteoma of the bones of the wrist. While the etiology of the disease is not understood, a developmental relationship between the osteoid-osteoma nidus and increased vascularity is suggested.

Adult↗
PubMedDate not supplied

Non-union of the clavicle in a child. A case report.

A case of symptomatic non-union of the clavicle occurred in a 12-year-old boy. Differential diagnosis roentgenographic and histologic observations, including the results of resection of the non-union site and stablization of the proximal clavicle using the coraco-acromial ligament demonstrated that this rare condition can be restored to full asymptomatic function without any internal metallic fixation devices.

Child↗