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Biomedical subjects

D J McDonald

Publications and source records attributed to D J McDonald.

At least 19 recordsLinked to original sources
PubMed1995

Appendicular metastatic prostate cancer simulating osteosarcoma, Paget's disease, and Paget's sarcoma.

Skeletal metastases from prostate cancer is common and usually do not pose a diagnostic dilemma. This study reviews radiographic appearances of prostatic metastases to the appendicular skeleton in four patients where the appearances simulated osteosarcoma, Paget's disease and Paget's sarcoma. Prostatic metastases to long bones can produce appearances considered characteristic of other lesions and suggest misleading alternative diagnoses.

Aged↗
PubMed1995

Assessment of argyrophilic nucleolar organizer region quantification in benign and malignant bone tumors.

Quantification of argyrophilic nucleolar organizer regions has been proposed as a technique that may aid in diagnosing and predicting the biologic behavior of a variety of neoplasms. A 1-step silver staining technique was used to identify and quantify argyrophilic nuclear organizer regions in a series of 96 bone tumor specimens. Malignant bone tumors had a higher mean argyrophilic nuclear organizer region count (3.05 +/- 0.82) than giant cell tumors (1.39 +/- 0.14, p < 0.001) and benign bone tumors (1.51 +/- 0.42, p < 0.001). Despite these differences in mean counts, an overlap of argyrophilic nuclear organizer region scores was observed in some benign and malignant cases. The argyrophilic nuclear organizer region counts of the osteosarcomas were analyzed to determine whether they correlated with tumor behavior. The mean argyrophilic nuclear organizer region count of specimens from patients in whom metastatic disease developed was not significantly different than that of patients who remained disease free.

Bone Neoplasms↗
PubMed1992

Recurrent hemarthrosis associated with gout.

Gout commonly occurs as an acute arthritis. In a 64-year-old man, gout was associated with a proliferative hemosiderin-laden synovitis. The association of recurrent atraumatic hemarthrosis seems not to have been reported in the literature on gout.

Gout↗
PubMed1992

Giant cell tumor of the capitate. A case report.

Giant cell tumors in the small bones of the hand are unusual, particularly in the carpus. A 28-year-old woman developed a giant cell tumor in the capitate. After biopsy, she was treated with complete excision of the capitate with no reconstruction. Five years later she had excellent hand function and no tumor recurrence. A careful roentgenographic and pathologic examination will distinguish between aneurysmal bone cysts and giant cell reparative granulomas. Complete excision of the involved bone is recommended.

Adult↗
PubMed1991

Magnetic resonance imaging in symptomatic Paget's disease.

Four patients with symptomatic Paget's disease of the appendicular skeleton were evaluated by magnetic resonance (MR) imaging. The plain film findings in each case were advanced but dissimilar. All patients had progressive symptoms of pain, and one presented with excruciating pain of short duration. The radiographic features included diffuse progressive osteolysis, cortical resorption, insufficiency fractures, bowing, and cortical and trabecular thickening. In three of the patients, MRI was performed to exclude sarcoma, revealing preservation of fatty marrow signal in all phases of Paget's disease except in patients with an acute fracture (demonstrated by MRI) and sarcoma. Small, focal, linear or oval areas of low signal seen against a background of normal marrow signal on short or long TR/TE do not mimic tumor. These findings suggest that fatty marrow signal is preserved in advanced Paget's disease unless an acute fracture or tumor is present.

Aged↗
PubMed1991

Case report 651: Thrombosed, leaking popliteal aneurysm.

A thrombosed, leaking aneurysm of the popliteal artery, mimicking a soft tissue sarcoma both clinically and by MRI examination, is described. It may be difficult to separate a leaking, thrombosed aneurysm from an inflammatory response secondary to a sarcoma with intralesional hemorrhage. An aneurysm should, however, be considered in the differential diagnosis if the mass is present in a well-recognized location for aneurysm and is associated with vascular engulfment and signs of subacute or chronic hemorrhage.

Aneurysm↗
PubMed1991

Prolongation of the QT interval by enflurane, isoflurane, and halothane in humans.

Previous investigations in laboratory animals have documented the ability of the volatile anesthetics to prolong the QT interval and the QT interval corrected for level of heart rate, QTc. The purpose of the present investigation was to evaluate the direct electrocardiographic and hemodynamic effects of enflurane, isoflurane, and halothane in healthy, unpremedicated patients using an inhalation induction to avoid the confounding effects of other anesthetic agents. Experiments were conducted in 22 adult male patients, (ASA physical status I or II) divided into three groups given either enflurane (n = 6), isoflurane (n = 8), or halothane (n = 8) anesthesia. Twenty-four-hour preoperative, preinduction, and postinduction hemodynamic and electrocardiographic measurements were obtained. Anesthetic blood concentrations, levels of plasma electrolytes, and arterial blood gas tensions were also quantitated. Halothane administration (0.81 +/- 0.06 mM) did not significantly alter the PR interval or QRS duration but significantly increased the QT (0.38 +/- 0.01 to 0.45 +/- 0.01 s) and QTc intervals (0.39 +/- 0.01 to 0.44 +/- 0.02 s). Isoflurane anesthesia (1.04 +/- 0.11 mM) did not significantly change QRS duration or PR and QT intervals but significantly prolonged the QTc interval (0.42 +/- 0.01 to 0.47 +/- 0.14 s). Similarly, enflurane anesthesia (2.16 +/- 0.13 mM) significantly prolonged the QTc (0.40 +/- 0.01 to 0.46 +/- 0.14 s) without change in QRS duration or PR and QT intervals. Plasma electrolyte levels and arterial gas tensions remained within normal limits in all patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Inhalation↗
PubMed1990

Influence of chemotherapy on perioperative complications in limb salvage surgery for bone tumors.

From 1970 to 1986, 304 patients underwent limb salvage resections for 271 malignant and 33 benign tumors of the extremities. Reconstruction was with a prosthesis or nonbiologic spacer. Nonmechanical complications were analyzed to determine the influence of the site and method of reconstruction and the use of chemotherapy on their incidence and severity. There were 82 shoulder resections, 53 proximal femur resections, and 169 knee resections. No chemotherapy was used in 115 patients; neoadjuvant therapy was used in 128 patients and adjuvant therapy was used in 61. There were 120 complications. The most common complication was infection (36 of 304 patients; 11.8%), which led to amputation in eight patients. Resections about the knee led to more complications than the other sites, particularly if reconstructed with a large cement spacer. Patients who did not receive any chemotherapy had a 25.2% (29 of 115) incidence of complications and those who received adjuvant treatment had a 32.8% (20 of 61) incidence. This compares with a 55.4% (71 of 128) incidence in the neoadjuvant group. After neoadjuvant chemotherapy, reconstruction with an uncemented prosthesis led to the fewest complications.

Antineoplastic Agents↗
PubMed1990

Myxoid liposarcoma: magnetic resonance imaging appearances with clinical and histological correlation.

Myxoid liposarcoma is the most common type of liposarcoma. The magnetic resonance imaging (MRI) features of this tumor were evaluated and correlated with its clinical and histological features in seven patients to determine under what circumstances the tumor should be considered in differential diagnosis and why its signal intensity differs from those of lipoma and lipoma-like (lipoblastic) liposarcoma. In all patients the tumor presented in a lower extremity (5 thigh, 2 calf) as a painless, slowly growing mass which had been present for several months to several years. MRI examination revealed the tumors to be encapsulated, noninfiltrating, and usually septated. On T1-weighted sequences five of seven lesions (71%) showed lacy, amorphous, or linear foci of high signal within a low signal mass. These foci are believed to represent fat within the tumor and distinguish it from several other benign and malignant masses. If an indolent mass in a lower extremity demonstrates a predominantly low signal with a few amorphous or linear high signal foci on T1-weighted sequences, one should consider the possibility of myxoid liposarcoma even if it appears benign by all other criteria. Histologic evaluation showed that myxoid liposarcomas contain less than 10% mature fat, which accounts for their low signal on T1-weighted sequences in contrast to the high signal of lipomas and lipoblastic liposarcomas.

Connective Tissue↗
PubMed1989

The stability and short-term fluctuation in serum oxytocinase activity in pregnancy.

Maternal serum samples obtained from 123 normal pregnant women between 28 and 40 weeks gestation were analysed for oxytocinase (EC 3.4.11.3) activity using s-benzyl-1-cysteine-4-nitroanilide as substrate. Oxytocinase activity was found to be stable at varying temperatures, with a mean co-efficient of variation of 5.0%. The short-term fluctuation of oxytocinase activity had a mean coefficient of variation of 3.6%. There is no suggestion of a "pulsatile" release of oxytocinae from its placental origin.

Aminopeptidases↗
PubMed1989

Characterization of the gene corresponding to bovine placental prolactin-related cDNA I: evolutionary implications.

We have previously characterized a family of transcripts, isolated from bovine placental tissue, that are related to prolactin (PRL) and are distinct from placental lactogen (PL). Here we describe a PRL-related gene that corresponds to one of these placental transcripts, bPRC-I. Restriction endonuclease mapping and sequence analysis of this gene reveal that it is distributed among five exons spanning approximately 9.2 kb. The site of transcription initiation was determined and repetitive sequences were localized in the first two introns. The nucleotide sequence of the coding region is 64% homologous to the bPRL gene and 44% homologous to the bovine growth hormone (bGH) gene. The 5'-flanking region shows no detectable homology to that of bPRL or bGH. Genomic Southern blot analysis indicates that this gene is a member of a family of PRL-related genes.

Amino Acid Sequence↗
PubMed1989

Two-stage reconstruction of a total hip arthroplasty because of infection.

From 1969 to 1985, eighty-one patients (eighty-two hips) who had an infection after a previous total hip arthroplasty were treated with a resection arthroplasty, followed by delayed reconstruction in the form of a repeat total hip arthroplasty. For all of the reconstructions, the femoral and acetabular components were fixed to bone with cement that did not contain antibiotics. An average of 5.5 years (range, 2.0 to 13.6 years) after reimplantation, infection had recurred in eleven hips (13 per cent). The presence of retained cement at the time of the resection arthroplasty appeared to be associated with recurrent sepsis, as three of seven patients who had retained cement had a recurrent infection, compared with only eight (11 per cent) of seventy-five patients from whom the cement had been completely removed (p less than 0.01). The twenty-six patients (twenty-six hips) who had the reimplantation less than one year after the resection arthroplasty had seven recurrent infections (27 per cent), while the fifty-six patients who had reimplantation more than one year after the resection arthroplasty had only four recurrences (7 per cent) (p less than 0.001). Three of the seven patients in whom the infection was caused by gram-negative bacilli and group-D streptococcal organisms (which are considered highly virulent) and who received systemic antimicrobial therapy for less than twenty-eight days had a recurrence. In contrast, only one of the thirteen patients in whom the infection was caused by a virulent organism and who were treated for longer than twenty-eight days had a recurrence (p = 0.055). The two-stage reconstruction is an effective, safe technique even when the infection is caused by a virulent organism.

Adult↗