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Biomedical subjects

S Wallace

Publications and source records attributed to S Wallace.

At least 199 records · Page 11Linked to original sources
PubMed1990

Sonographic features of benign intraperitoneal lipomatous tumors in children--report of 4 cases.

Four children with benign intraperitoneal lipomatous tumors (mesenteric lipoma, mesenteric lipoblastoma, omental lipoblastoma and mesenteric mesenchymoma) are reported. The ultrasonographic findings of these unusual pediatric masses are described and correlated with their conventional radiologic and pathologic appearance. The pre-operative diagnosis of these entities can be suggested by these features.

Child↗
PubMed1990

Magnetic resonance imaging in aggressive fibromatosis.

The magnetic resonance imaging (MRI) features of aggressive fibromatosis in 11 patients (five with recurrent tumour) and its contribution to patient management are described. Tumour signal intensity ranged from being low to isointense with respect to muscle on T1-weighted images while being predominantly of heterogenous increased signal intensity on T2-weighted images. A post-contrast (Gd-DTPA) study demonstrating diffuse tumour enhancement was of value in assessing tumour extent in two patients. CT in six patients and angiography in two patients provided no additional information while tumour relationship to neurovascular structures and extent was better appreciated on MRI. MRI was accurate in predicting resectability in all six patients who had surgery.

Adolescent↗
PubMed1990

Intracarotid cisplatin-based chemotherapy in patients with malignant melanoma and central nervous system (CNS) metastases.

Twenty-three patients with malignant melanoma metastatic to the central nervous system (CNS) were treated with intracarotid cisplatin-based chemotherapy. Twenty-two had failed prior cranial radiation therapy (one patient refused radiation therapy) and had progressive brain metastases documented by computerized tomography (CT). Intracarotid cisplatin 40-75 mg/m2 was administered alone (seven patients) with 1,3-bis(2-Chloroethyl)-1-nitrosourea (BCNU) (13 patients) or bleomycin (three patients). Courses were repeated monthly with CT scan. Seven patients (30%) had objective improvement in CT scans and three patients (13%) had stabilization of disease. The median time to tumor progression for responding patients was 20 weeks (range 8-34 weeks) while stable disease ranged from 9-12 weeks. In three patients the extracranial disease progressed while the brain metastases responded. Neurological and retinal toxicity were potential complications of therapy. Intracarotid cisplatin-based chemotherapy may be useful for palliation in selected patients with malignant melanoma and CNS metastases.

Adult↗
PubMed1990

Covert self poisoning with brodifacoum, a 'superwarfarin'.

The clinical course of a patient poisoned with the 'superwarfarin' brodifacoum and a method for estimation of plasma levels is described. It was characterised by prolonged depression of Vitamin K-dependent clotting factors poorly responsive to Vitamin K administration.

4-Hydroxycoumarins↗
PubMed1990

Myristylated polyomavirus VP2: role in the life cycle of the virus.

The double-stranded genome of the small DNA tumor virus, polyomavirus, is enclosed in a capsid composed of a major protein, VP1, which associates as pentameric capsomeres into an icosahedral structure, and two minor proteins, VP2 and VP3, whose functions and positions within the structure are unknown. The N-terminal glycine of the VP2 coat protein has been shown to be cotranslationally acylated with myristic acid. To study the function of this modification and the role of VP2 in the life cycle of polyomavirus, the N-terminal glycine, critical to the myristylation consensus sequence, has been altered to a glutamic acid or a valine residue by site-directed oligonucleotide mutagenesis. The glycine----glutamic acid mutant DNA has been further studied. When transfected into cells permissive for the polyomavirus full lytic life cycle, this mutant DNA replicated at levels comparable to those of wild-type viral DNA, and small amounts of nonrevertant (mutant) virus could be harvested from the cultures. The virus particles viewed by electron microscopy appeared slightly distorted, but the ratio of full to empty particles was similar to that produced in a wild-type viral infection. Mutant virus was capable of reinfecting permissive cells but with a considerably reduced efficiency.

Animals↗
PubMed1990

Osteosarcoma: MR imaging after preoperative chemotherapy.

The authors reviewed 76 magnetic resonance (MR) images of 38 patients with osteosarcoma treated with preoperative chemotherapy (intraarterial cisplatin with or without systemic chemotherapy). Histologic maps of the surgical tumor specimens in 33 cases were correlated with either late-chemotherapy or postchemotherapy MR images. There were four MR patterns--dark, mottled or speckled, homogeneous, and cystic--that corresponded to different amounts of tumor matrix, granulation tissue, hemosiderin deposits, fluid-filled cysts, and residual viable tumor. Nested foci of residual viable tumor could not be specifically identified, although tumor progression or skip metastases were accurately depicted in four patients. Other findings included (a) peritumoral edema in the soft tissues and intramedullary space that shrank with chemotherapy, (b) chemotherapy effect in the surrounding soft tissues, (c) a dark rim around the extramedullary component of the tumors corresponding to a collagenous capsule continuous with the periosteum, (d) development of metaphyseal hemorrhages and bone marrow infarcts, and (e) intramedullary vascular channels.

Adolescent↗
PubMed1990

Liposome distribution after intravenous and selective intraarterial infusion in dogs.

In an effort to improve hepatic uptake of liposomes for drug delivery, empty vesicles were administered by means of selective arterial infusion. Negatively charged, multilamellar liposomes were labeled with technetium-99m and infused into healthy adult dogs. Each dog received 100 mg/m2 of lipid over 10 minutes at 2 mL/min. Liposomes were administered via the common hepatic artery after proximal occlusion of the gastroduodenal artery, via the cranial mesenteric artery, and via the cephalic vein. Distribution (liver, spleen, and lungs) was determined by computer-assisted external imaging techniques. On the average, after arterial infusion, 69.2% of the total activity was located in the liver, 3.6% in the spleen, 3.2% in the lungs, and 3.5% in the general circulation. Following venous injection, 50.7% of the radioactivity was found in the liver, 9.1% in the spleen, 8.6% in the lungs, and 6.7% in the peripheral blood. Once the liposomes entered the systemic circulation, they were cleared at the same rate (half-life beta = 21.5 hours) independent of their route of administration. Increased hepatic liposome uptake should translate into higher local and lower systemic liposomal drug levels.

Animals↗
PubMed1990

Expandable metallic biliary endoprostheses: preliminary clinical evaluation.

A biliary endoprosthesis constructed of self-expanding metallic "Z" stents was placed in 23 patients with obstructive jaundice. The biliary obstruction was due to a malignant neoplasm in 21 patients and a postoperative biliary stricture in two patients. The lesions affected the intrahepatic biliary ducts in 13 patients. Twelve patients had undergone radiation therapy before stent placement. The endoprostheses consisted of 196 expandable metallic biliary stents placed singly (n = 10) or in tandem (n = 186). As many as 18 stents were used to relieve an obstruction in one patient. A transhepatic approach was employed in all patients except one in whom stents were placed through a T-tube tract. Within 1 week after placement, all stents expanded to at least 90% of their original diameter. Three misplaced, two deformed, and two dislodged stents caused no obvious clinical problems. At follow-up, which ranged from 2 to 59 weeks, five patients experienced recurrent jaundice. Two patients with recurrent jaundice due to obstruction of the bile duct containing the stent were treated with external catheter drainage. The expandable biliary endoprosthesis is suggested as an effective treatment for benign and malignant biliary obstruction.

Adult↗
PubMed1990

Pediatric osteosarcoma: therapeutic strategies, results, and prognostic factors derived from a 10-year experience.

Ninety-eight pediatric patients were treated with three separate protocols (Treatment and investigation of Osteosarcoma [TIOS] I, II, and III) and 47 developed recurrent disease (metastases and/or local recurrence). Actuarial overall disease-free survival (hereafter designated survival) was 43%. Over 90% of the patients were treated initially with preoperative intraarterial cisplatin (CDP). Postoperative chemotherapeutic regimens comprised high-dose methotrexate with leucovorin rescue (MTX-CF), Adriamycin [( ADR] doxorubicin; Adria Laboratories, Columbus, OH), and cyclophosphamide. Primary definitive treatment comprised amputation or limb salvage (TIOS I and TIOS III). Patients treated with preoperative CDP and surgery (TIOS I and III) had a 62% survival. Patients in TIOS II refused surgical extirpation; they were treated exclusively with chemotherapy and had a 23% survival. Survival in patients treated with amputation was 55% and limb salvage 58%. Prognostic factors considered significant in relation to development of pulmonary metastases comprised tumor burden (P = .04) and the percentage of tumor necrosis induced by preoperative chemotherapy (P = .01). Histopathologic subtype was marginally significant: chondroblastic was more favorable as opposed to osteoblastic (P = .05). These findings are compared with results and prognostic factors published in the literature.

Child↗
PubMed1990

Splenic versus hepatic artery infusion of interleukin-2 in patients with liver metastases.

In an attempt to improve the therapeutic index of recombinant interleukin-2 (rIL-2) by generating or activating lymphokine-activated killer (LAK) cells and tumor-infiltrating lymphocytes (TIL) regionally and/or in situ, we randomly assigned 28 patients with liver metastases to receive rIL-2 by continuous infusion for 5 days via either the splenic artery or the hepatic artery. Clinically significant and lasting tumor regression was observed only in two of 28 patients (7%), one in each of the two treatment arms. The maximum-tolerated daily dosage of rIL-2 was 3 x 10(6) U/m2; beyond this dosage, toxicity was excessive. Peripheral LAK cell activity measured in vitro and clinical tumor regression did not correlate. This observation, coupled with the equal distribution of regressions between the two treatment arms, raises the possibility that tumor regression, rare though it may be in response to rIL-2 administration, is largely mediated by TIL activation and not by LAK cell generation.

Female↗
PubMed1990

Radiological features of extraskeletal Ewing sarcoma.

The radiological features of extraskeletal Ewing sarcoma were reviewed in 22 patients whose average age was 22 years. Tumours were located in the extremities (11 patients), abdomen or pelvis (six patients) and the chest (five patients). The tumours ranged in size from 2 cm to 20 cm, were mainly well circumscribed and showed no evidence of calcification prior to treatment. Most tumours (13 out of 14) were of low attenuation or contained areas of lower attenuation than muscle on computed tomographic examination, and in six out of seven patients studied by ultrasound the tumours were hypoechoic or partly anechoic. No distinctive post-contrast medium enhancement pattern on CT examination (11 patients) or angiographic features (three patients) were evident. Tumour haemorrhage was a frequent microscopic finding and changes consistent with this were present in one patient on magnetic resonance imaging examination. Distant metastases or local recurrence developed in 13 patients with lung being the most frequent metastatic site (eight patients). Although its radiological features are non-specific, extraskeletal Ewing sarcoma should be included in the differential diagnosis of noncalcified soft-tissue tumours especially in a young age group and where located in an extremity or paravertebral region of the chest.

Abdominal Neoplasms↗
PubMed1990

AIDS knowledge and homophobia among French and American university students.

22 male American and 24 male French college students' knowledge of AIDS scores were equivalent on a currently constructed 18-item questionnaire. Both groups answered more than 75% of the questions correctly. The American students' homophobic bias and reaction scores were higher than those of the French students on a 43-item homophobic questionnaire. The latter findings were interpreted as consistent with reduced effects of conservative, orthodox religion in France and the stability of traditional religious influence in America over the past three decades. No relation was found between knowledge of AIDS and homophobia in these small conveniently available samples.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Fine needle aspiration biopsy in lymphoma.

Patients with lymphoma undergo excisional biopsy of an affected lymph node for initial classification of their disease because accurate classification depends on the histologic characteristics of the neoplasm. However, fine needle aspiration cytology has a role in the management of lymphoma patients, particularly in those with recurrent or residual masses following treatment. Moreover, immunologic markers, nucleic acid flow cytometry, cytogenetics, and molecular genetics, which do not depend on histologic characteristics and can be performed on fine needle aspirates, are acquiring more importance in the management of patients with these diseases, particularly in those with non-Hodgkin's lymphoma. These latter tests add objectivity to the cytologic diagnosis of the B-cell lymphomas and increase its accuracy. In most series, the accuracy of fine needle aspiration in patients with lymphoma approaches 90%, with minimal complication rates.

Biopsy, Needle↗
PubMed1989

Small cell osteosarcoma. A clinicopathologic study of 27 cases.

We report a study of 27 patients with small cell osteosarcoma (SCO), 17 from the M. D. Anderson Cancer Center (MDAH) and ten from the Pediatric Oncology Group (POG). There were 12 male patients and 15 female patients; 19 were white, five were black, and three were Hispanic. They ranged from 6 to 28 years of age with a median of 14 years. Histologically there were three patterns: Ewing's-like, lymphoma-like, and spindle cell. All cases showed osteoid formation and a few had chondroid areas. There was cytoplasmic glycogen in ten cases. Initial treatment for MDAH patients included intraarterial infusion of cisplatin in ten, amputation in four, partial mandibulectomies in two, and biopsy with local radiotherapy and systemic chemotherapy in one. All POG patients had resection or amputation followed by adjuvant chemotherapy. Twelve patients are alive, of whom nine have had significant follow-ups for 25 to 90 months. Fourteen patients are dead of lung, spine, and brain metastases from 1 to 23 months after initial diagnosis. One patient is alive with lung relapse at 4 months. In summary, SCO is a high-grade variant of osteosarcoma, with an incidence of up to 4% of all osteosarcomas, that affects patients of the same age group and has the same anatomic location as conventional osteosarcoma. Currently, SCO appears to have a prognosis that is the same as or slightly worse than that of conventional osteosarcoma. Furthermore, although intraarterial infusion is effective for the primary tumors in the bone, distant metastases are difficult to control.

Adolescent↗
PubMed1989

Hepatic arterial infusion of human recombinant tumor necrosis factor-alpha. An experimental study in dogs.

Local and systemic toxicities associated with hepatic arterial infusion of human recombinant tumor necrosis factor (rTNF) were studied in healthy adult mongrel dogs. The animals received saline containing human serum albumin with or without rTNF (0.02, 0.2, or 2.0 mg/m2). Arteriograms were made, and blood samples were collected for hematologic and biochemical analyses at regular intervals. The dogs were killed at 1, 3, and 7 days postinfusion and complete necropsies were performed. Specimens were obtained from various tissues for histopathologic evaluation. Results indicated that all but the highest dose of rTNF were well tolerated. Severe histopathologic changes were found in the liver, spleen, and kidneys of the animals receiving 2.0 mg/m2 rTNF. In addition, focal tubular degeneration was found in one dog administered 0.2 mg/m2 rTNF. These data suggest that the upper dose limit for hepatic arterial infusion of rTNF is between 0.2 and 2.0 mg/m2 and that renal function should be closely monitored after infusion.

Angiography↗
PubMed1989

Effect of cumulative courses of intraarterial cis-diamminedichloroplatin-II on the primary tumor in osteosarcoma.

Preoperative chemotherapy with intraarterial cis-diamminedichloroplatin-II (CDP) and mannitol diuresis was administered to the primary tumor in 42 patients with osteosarcoma. The dose was 150 mg/m2 and more than 90% of the infusions were administered during a 2-week period. On occasion this period was extended to 3 weeks because of temporary renal insufficiency or logistical circumstances. Definitive surgical specimens were prepared by means of an arteriogram-directed plane of dissection with mapping and random sections. Histologically, tumor destruction was evaluated in terms of necrosis, inflammatory response, and fibrovascular regeneration. Quantification of the percent of tumor necrosis was as follows: less than 40% (consistent with spontaneous necrosis and/or no chemotherapy effect); 40% to 60% (possible chemotherapy effect); 60% to 90% (chemotherapy effect--partial response); and 90% to 100% (complete response). Therapeutic efficacy also was correlated with the number of CDP courses (one to three, four to five, and six to seven) and tumor subtype. Significant therapeutic effect (greater than 60% destruction) was observed with four or more CDP courses (one of nine tumors [one to three courses] versus 26 of 33 tumors [four to seven courses] [P = 0.01]). More than 60% of the tumor destruction was observed in the following subtypes: osteoblastic (22 of 28), fibroblastic (three of six), and telangiectatic (two of five). These data demonstrate that four or more courses of intraarterial CDP are required to achieve optimum effects and that osteoblastic osteosarcoma is highly responsive.

Cisplatin↗